diff --git a/marked/F/T-REC-F.100-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.100-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..64672153e39c851d9e16fdbc702e526c7ba7e8a7 --- /dev/null +++ b/marked/F/T-REC-F.100-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:454a9958ffe168868cb7d38a0eb24418dafe31a7a4245c992089b2316ac37d3e +size 7392 diff --git a/marked/F/T-REC-F.104-199110-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.104-199110-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..19819f529f52e7da1816c13cbe2053850fe3c57f --- /dev/null +++ b/marked/F/T-REC-F.104-199110-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f09f10840d9270effd61b9bf244f3ce48bb34a123133778505623acaa4163a8d +size 7487 diff --git a/marked/F/T-REC-F.104-199110-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg b/marked/F/T-REC-F.104-199110-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..fa92ec258bb4c13b6799271d64ebcf6b337ea8c9 --- /dev/null +++ b/marked/F/T-REC-F.104-199110-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:495c6c5b5acabcf027f4b5444cdec07c1959db3d409caa558de1bfc54abb8dc6 +size 5750 diff --git a/marked/F/T-REC-F.104-199110-I_PDF-E/raw.md b/marked/F/T-REC-F.104-199110-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..b45b6915f718c96975fba7cdd7df03be202ef150 --- /dev/null +++ b/marked/F/T-REC-F.104-199110-I_PDF-E/raw.md @@ -0,0 +1,101 @@ + + +![ITU logo: A globe with the letters ITU and a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: A globe with the letters ITU and a lightning bolt. + +INTERNATIONAL TELECOMMUNICATION UNION + +**CCITT** + +**F.104** + +THE INTERNATIONAL +TELEGRAPH AND TELEPHONE +CONSULTATIVE COMMITTEE + +**TELEGRAPH AND MOBILE SERVICES +OPERATIONS AND QUALITY OF SERVICE** + +--- + +**INTERNATIONAL LEASED CIRCUIT +SERVICES – CUSTOMER +CIRCUIT DESIGNATIONS** + +**Recommendation F.104** + +--- + +![CCITT logo: A globe with the letters CCITT.](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +CCITT logo: A globe with the letters CCITT. + +Geneva, 1991 + +# FOREWORD + +The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988). + +Recommendation F.104 was prepared by Study Group I and was approved under the Resolution No. 2 procedure on the 11th of October 1991. + +## --- CCITT NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication Administration and a recognized private operating agency. + +## Recommendation F.104 + +# INTERNATIONAL LEASED CIRCUIT SERVICES – CUSTOMER CIRCUIT DESIGNATIONS + +## 1 Introduction + +1.1 CCITT Recommendation M.140 (Designations of international circuits, groups, group and line links, digital blocks, digital paths, data transmission systems and related information) specifies a scheme for the designation of international routes 1). + +1.2 The designation scheme is based on a layered approach with: + +layer 1 – a unique identification providing limited information; + +layer 2 – additional information that must be known at both termination of the route; and + +layer 3 – (optional) – bilateral information not the subject of international standardization. + +## 2 General + +2.1 Layer 1 of the Recommendation M.140 designation scheme provides unique circuit information that is common at both ends of the route and is suitable to be made available to the customer as the *customer international circuit designations*. + +## 3 Customer international circuit designations + +3.1 Section 3 of Recommendation M.140 specifies the format of the designation for fixed circuits as given in the following subsections. An example of the format of a unique circuit designation is shown in Figure 1/F.104. + +3.2 The customer circuit designation should be in accordance with layer 1 designation of § 3.2 of Recommendation M.140. + +3.2.1 Towns A and B, with a possible (optional) transmission station suffix, should identify the terminal points of the circuit. They appear in alphabetical order. + +3.2.2 The identification of the terminal point is up to the Administration concerned. In cases where the town name exceeds the maximum length of 12 characters, the Administration should supply a suitable abbreviation which must be unique. The use of the last three characters to indicate the country is suggested. + +3.2.3 The transmission station suffix is an optional field which may be used further to identify the terminal point, e.g. when there is more than one RPOA operating in the town. The need for a suffix and its form should be decided by the RPOA concerned. + +3.2.4 The function code should identify the type of circuit. Function codes should be in accordance with Recommendation M.140. + +3.2.5 The serial number should be a separate numbering series for each traffic relation and function code. In the case of more than one RPOA, serial numbering will be on a transmission station to transmission station and functional code basis. + +--- + +1) The word “route” in this context has a very general meaning. + +3.3 Layer 2 of Recommendation M.140 is meant for Administration use. + +3.4 In special cases in which CCITT Recommendations do not apply, the circuit designation should be bilaterally agreed between the two terminal Administrations. + +*Example:* BERN/1RS-NEW YORK/1RC TP1 + +| Format of designation | Town A | Delim-
iter (/) | Trans-
mission
station
suffix
optional | Delimi-
ter (-) | Town B | Delimi-
ter (/) | Trans-
mission
station
suffix
optional | Delim-
iter
(Space) | Function
code | Serial
No. | +|-----------------------|--------|--------------------|----------------------------------------------------|--------------------|-------------|--------------------|----------------------------------------------------|---------------------------|------------------|---------------| +| e.g. | BERN | / | 1RS | - | NEW
YORK | / | 1RC | Sp | TP | 1 | +| No. of Characters | 1-12 | 1 | 1-3 | 1 | 1-12 | 1 | 1-3 | 1 | 1-4 | 1-4 | + +FIGURE 1/F.104 + +**Format of unique circuit designation** \ No newline at end of file diff --git a/marked/F/T-REC-F.105-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.105-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b1838c2c3bae3aebb318913edd09fcedd61b1afe --- /dev/null +++ b/marked/F/T-REC-F.105-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:39fecafb2f82be549519274cbcc76e5c508ef064a283e3aabfe904469e087b93 +size 7504 diff --git a/marked/F/T-REC-F.105-198811-I_PDF-E/raw.md b/marked/F/T-REC-F.105-198811-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..9567416ffb8ef5768c1f804e06322a54ea8e3534 --- /dev/null +++ b/marked/F/T-REC-F.105-198811-I_PDF-E/raw.md @@ -0,0 +1,109 @@ + + +![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +The logo of the International Telecommunication Union (ITU) features the letters 'ITU' in a bold, sans-serif font, superimposed on a stylized globe with intersecting lines. + +ITU logo + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**F.105** + +# **OPERATIONS AND QUALITY OF SERVICE TELEGRAPH SERVICES** --- + +## **OPERATIONAL PROVISIONS FOR PHOTOTELEGRAMS** + +**ITU-T Recommendation F.105** + +(Extract from the *Blue Book*) + +--- + +### NOTES + +1 ITU-T Recommendation F.105 (new numbering of Rec. F.80) was published in Fascicle II.4 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below). + +2 In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +## OPERATIONAL PROVISIONS FOR PHOTOTELEGRAMS1) + +### 1 Field of application + +1.1 These rules apply to phototelegrams in both continental and intercontinental relations (exchanged between public stations or between public stations and private stations). The provisions concerning the exchange of phototelegraph calls between private stations or from private to public stations are embodied in Recommendation F.80 *bis* and D.81. + +1.2 The rules governing the method of communication between phototelegraph stations are embodied in Recommendation F.82. + +### 2 General + +2.1 Private stations may be authorized by the Administrations concerned to exchange phototelegrams with public stations. + +2.2 In both continental and intercontinental relations, private stations communicate directly with public stations providing that the characteristics of their equipment conform with CCITT Recommendations. + +2.3 Administrations shall agree upon the working hours of their phototelegraph offices. The hours during which private offices are open shall be fixed by the private organization concerned. + +### 3 Conditions of acceptance + +3.1 In order to ensure satisfactory transmission of a phototelegram it is recommended that senders should be advised to avoid the use of the colours blue, lilac, green or yellow, or gilt print, or prints on yellow, red or grey paper, which lack the qualities necessary for good transmission, and to avoid handing in phototelegrams with very weak contrast or inadequate definition. + +3.2 If, after the sender has been informed that the general quality of the original phototelegram is not suitable for satisfactory transmission, he insists on handing it in, the phototelegram shall only be accepted at the risk of the sender. In this case the service instruction **RISQUES EXPEDITEUR** shall be included in the preamble. + +3.3 Phototelegrams must be rectangular in shape. Each Administration shall decide what is the maximum format capable of being sent in a single transmission by all the machines used by that Administration. However, in relations where equipment is used permitting the single transmission of greater areas, Administrations may authorize larger sizes. + +3.4 Phototelegrams of larger dimensions than those admitted in the relation concerned must be divided into parts by the sender. The order of transmission of the parts must be indicated. + +3.5 In phototelegraph transmission a strip of the edges of the phototelegram may be lost on two opposite sides of the document to be transmitted. For this reason care should be taken when dividing a phototelegram to see that there is no loss at the separation line. If there is any doubt, the sender may be advised to authorize the division of the phototelegram by the phototelegraph station. + +3.6 It may happen that the format of phototelegrams is enlarged or diminished during a phototelegraph transmission, owing to the different characteristics of the sending and receiving equipment. If this is so, however, the phototelegram will be reproduced with the same proportions as the original. + +### 4 Arrangement of the parts of a phototelegram + +4.1 Every phototelegram must bear an address. A signature shall be optional. The address and the signature shall form part of the phototelegram to be transmitted. + +4.2 Every phototelegram shall include a preamble. The relevant instructions shall be the same as those for the preamble line of a telegram. But the number of words shall be replaced by a statement of the charging step. + +--- + +1) See also Recommendation D.80. + +### 5 Handing in a phototelegram + +- 5.1 A phototelegram may be handed in: +- at the counter of an authorized telegraph office; + - directly at a public station (handing in by messenger). +- 5.2 A phototelegram from a private station which is received by a public station for delivery to the addressee or for retransmission shall be considered as having been handed in at the public station (handing in by phototelegraphy). +- 5.3 Depending on the method used, the time of handing in shall be: +- the time of acceptance at the counter of a telegraph office; + - the time of acceptance by the public station (in the case of direct handing in); + - the time of arrival at the public station (service from a private station to a public station). + +### 6 Transmission of a phototelegram + +- 6.1 Phototelegrams of the same rank shall be transmitted by the outgoing station in the order in which they are handed in, and by the intermediate stations in the order of reception. +- 6.2 A phototelegram to a private station shall, after closure of its office or if its equipment is out of order, be routed to another station of the incoming country only by agreement with the sender. +- 6.3 A transmission that is unsuccessful because of adverse transmission conditions should be repeated as soon as circumstances permit. +- 6.4 But if the sender could be informed of unsatisfactory transmission conditions and if he insists upon an attempt at transmission being made, the phototelegram shall be accepted only at the risk of the sender. In this case the service instruction **RISQUES EXPEDITEUR** shall be included in the preamble. If the copy received at the receiving phototelegraph station is not satisfactory after a maximum of three attempted transmissions, no further re-runs should, in principle, be attempted. The sender should be notified of the circumstances. + +### 7 Delivery of a phototelegram + +- 7.1 Phototelegrams received by a public station shall be delivered unless they are to be retransmitted. A phototelegram may be delivered to an addressee in the locality where the public receiving station is located: +- by messenger; + - through personal collection by the addressee. +- 7.2 A phototelegram transmitted from a public station to a private station shall be considered as delivered to the addressee (delivery by phototelegraphy). +- 7.3 Phototelegrams addressed to localities that are not connected to the phototelegraph network shall be delivered by post. They shall be considered as postal correspondence from the time they are handed over to the postal service. +- 7.4 For special reasons, a phototelegram may be kept on hand at a public station – at the sender's request – until a private station re-calls it (collection by phototelegraphy). A public station having phototelegrams on hand intended for a private station shall not act on a request for transmission made by the private station until it has satisfied itself of the identity of the latter. +- 7.5 Depending on the method applied, the time of delivery of a phototelegram shall be: +- the time of delivery to the addressee; + - the time when the addressee, having been informed of the received phototelegram, expresses the intention of sending a private messenger; + - the time when the transmission is terminated, in service from a public station to a private station; + - the time of handing over to the postal service in the case of delivery of post. + +### 8 Charging + +- 8.1 The rates for phototelegrams in continental and in intercontinental relations exchanged between public stations or from a public station to a private station are governed in Recommendation D.83. \ No newline at end of file diff --git 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+CONSULTATIVE COMMITTEE + +**F.14** + +(08/92) + +**TELEGRAPH AND MOBILE SERVICES +OPERATIONS AND QUALITY OF SERVICE** + +--- + +**GENERAL PROVISIONS FOR +ONE-STOP-SHOPPING ARRANGEMENTS** + +**Recommendation F.14** + +--- + +![CCITT logo: A globe with the letters CCITT.](84a1d09fb489061482111515543b60dc_img.jpg) + +CCITT logo: A globe with the letters CCITT. + +Geneva, 1992 + +# FOREWORD + +The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988). + +Recommendation F.14 was prepared by Study Group I and was approved under the Resolution No. 2 procedure on the 4th of August 1992. + +--- + +## CCITT NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication Administration and a recognized private operating agency. + +# **GENERAL PROVISIONS FOR ONE-STOP-SHOPPING ARRANGEMENTS** + +(1992) + +## **1 Introduction** + +### **1.1 Scope** + +This Recommendation sets out the general procedures for the implementation of one-stop-shopping (OSS) arrangements associated with the customer provision of international telecommunication services. + +1.2 OSS may be defined as an optional arrangement for both customer and Administration whereby a single Administration (the coordinating Administration) provides and/or coordinates with other Administrations (the participating Administrations) the provision of one or more telecommunication services. It is designed to simplify for the customer the ordering, implementation and billing procedures currently undertaken by each Administration for the establishment and ongoing provision of international services. + +### **1.3 Options** + +The OSS arrangements may include one or more of the following customer options: + +- a) single end ordering; +- b) single end billing1); +- c) single contact point fault reporting; +- d) maintenance coordination. + +Where the customer so wishes, the OSS arrangement may also encompass those other components of a customer network that do not originate or terminate within the operating area of the coordinating Administration. + +The OSS arrangement requires close coordination and designation of contact points among the Administrations concerned at all levels, commercial, administrative and technical. + +## **2 Organizational aspects** + +2.1 Administrations should designate contact points for participating Administrations, making due allowance for any difference in time zones, for the following activities: + +- a) enquiry/pre-sales activities; +- b) ordering/confirmation between Administrations; +- c) billing and inter-Administration accounting; +- d) maintenance coordination and customer support. + +### **2.2 Information exchange** + +Through the coordinating Administration, customers may obtain end-to-end information about services, tariffs, delivery times, etc., from any participating Administration. If the information is not immediately available, the coordinating Administration may request the necessary details from the contact points of the other Administration(s) involved. Administrations should endeavour to provide the requested information promptly. + +--- + +1) Billing and accounting aspects are covered in the relevant D-Series Recommendations. + +### 2.3 *Selection* + +The customer will select the Administration it wishes to act as the single point of contact among the Administrations involved in providing the service. Agreement to the customer's selection or any subsequent changes in that selection shall not be unreasonably withheld by other Administration(s). + +### 2.4 *Quotation* + +A quotation should be prepared by the coordinating Administration for the customer, as agreed by contact points of the participating Administrations. Participating Administrations shall agree on the content of their respective parts of a quotation before submission to the customer. + +### 2.5 *Ordering* + +The coordinating Administration shall assume responsibility for handling the ordering arrangements for the customer. The coordinating Administration should arrange for the customer to sign and complete the forms required by the participating Administration concerned. + +### 2.6 *Order progress* + +The coordinating Administration should be responsible for providing the customer with information on the progress of service provision. Should any problems or delays occur within a participating Administration's field of responsibility, the coordinating Administration should be notified immediately, and *vice versa*. + +## 3 **Operational aspects** + +3.1 The coordinating Administration should normally be responsible to the customer for the overall coordination of the service installation, testing, advising the customer of service availability, and the coordination of on-going maintenance. + +3.2 The coordinating and participating Administration(s) should designate the centres which will interface with each other for installation, testing and ongoing maintenance, in accordance with the relevant M-Series Recommendations. The centre of the coordinating Administration should normally function as the coordinating centre, unless otherwise agreed by the Administrations concerned. When the service does not pass through the territory of the coordinating Administration, a coordinating centre should be chosen from one of the participating Administrations in consultation with the coordinating Administration. + +3.3 The coordinating centre should contact the participating centre(s) and agree on a programme of tests to be conducted in accordance with the relevant CCITT Recommendations. The coordinating and participating Administration(s) should agree on the following dates, as appropriate for the service concerned: + +- *ready for service date*: which is the date when the service should be complete and made available to the customer. +- *national test date*: which is the date by which the domestic parts of the service will be installed and tested in the respective countries. +- *line-up test date*: which is the date that the service will be tested between the respective international centres. +- *end-to-end test date*: which is the date that the service will be tested overall. + +3.4 When the service is handed over to the customer and accepted, the coordinating Administration should advise all participating Administrations that the service is now in use. + +3.5 When the customer has selected single contact point fault reporting, faults should be reported to the coordinating centre which then coordinates fault investigation and clearance. The coordinating centre should keep the customer informed as to fault clearance status. + +3.6 Testing maintenance functions should be performed in accordance with the relevant M-Series Recommendations. \ No newline at end of file diff --git a/marked/F/T-REC-F.140-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.140-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..431f7cf6555f330169ff19e3158a5f6f4b136273 --- /dev/null +++ b/marked/F/T-REC-F.140-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5603f29a95a0e06c23a7d999918e378ff6b453c50915bd3f942fba08cc4ba16b +size 8286 diff --git a/marked/F/T-REC-F.140-199303-I_PDF-E/fc46871d72c65d3381d9201646d23439_img.jpg b/marked/F/T-REC-F.140-199303-I_PDF-E/fc46871d72c65d3381d9201646d23439_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..cb7c15ca14bab6ab1bc2eb38321b84e957303356 --- /dev/null +++ b/marked/F/T-REC-F.140-199303-I_PDF-E/fc46871d72c65d3381d9201646d23439_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:63ce0aa4e4211f23bade5718e25166dc0c5f57f042fa7aa8b73ec3872700fd6d +size 106658 diff --git a/marked/F/T-REC-F.140-199303-I_PDF-E/raw.md b/marked/F/T-REC-F.140-199303-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..290a1e1680adea674f7545b09de646d6a56e74d8 --- /dev/null +++ b/marked/F/T-REC-F.140-199303-I_PDF-E/raw.md @@ -0,0 +1,200 @@ + + +![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +The logo of the International Telecommunication Union (ITU) features a globe with a lightning bolt striking across it, and the letters 'ITU' superimposed on the globe. + +ITU logo + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**F.140** + +(03/93) + +**OPERATIONS AND QUALITY OF SERVICE +MOBILE SERVICE** + +--- + +**POINT-TO-MULTIPOINT TELECOMMUNICATION +SERVICE VIA SATELLITE** + +**ITU-T Recommendation F.140** + +(Previously "CCITT Recommendation") + +--- + +# FOREWORD + +The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecommunication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +ITU-T Recommendation F.140 was revised by the ITU-T Study Group I (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). + +--- + +# NOTES + +1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector. + +In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms "CCITT, CCIR or IFRB" or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. + +2 In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# CONTENTS + +*Page* + +| | | | +|-----|--------------------------------------|---| +| 1 | Scope..... | 1 | +| 1.1 | Definition of service ..... | 1 | +| 2 | Service description..... | 1 | +| 2.1 | Functional elements of service ..... | 1 | +| 2.2 | Service provision ..... | 2 | +| 2.3 | Types of service..... | 2 | +| 2.4 | Areas of service coverage ..... | 2 | +| 2.5 | Service configurations ..... | 2 | +| 3 | Quality of Service ..... | 2 | +| 3.1 | Service availability ..... | 3 | +| 4 | Access ..... | 4 | +| 4.1 | Transmit..... | 4 | +| 4.2 | Receive ..... | 4 | +| 5 | Classes of space segment ..... | 4 | + + + +# **POINT-TO-MULTIPOINT TELECOMMUNICATION SERVICE VIA SATELLITE** + +*(Melbourne, 1988; revised Helsinki, 1993)* + +The CCITT, + +*considering* + +- (a) the need for a point-to-multipoint telecommunication service; +- (b) the loss of the HF multi-destinational Press broadcast service for this purpose; +- (c) the availability of satellites for point-to-multipoint telecommunications services on a regional and world-wide basis; +- (d) the availability of a multiplicity of earth station sizes; +- (e) the need for a clarification in terms of the functional elements of this service; +- (f) the need for the flexibility of their implementation in order to adapt to the needs of all Administrations, + +*recommends* + +the following operational guidelines and Quality of Service requirements for an international point-to-multipoint telecommunication service via satellite. + +## **1 Scope1)** + +This Recommendation provides operational guidelines and Quality of Service requirements for an international one-way point-to-multipoint telecommunication service via satellite. See Recommendation D.185 for the general tariff and accounting principles for the international point-to-multipoint telecommunication service via satellite. + +## **1.1 Definition of service** + +The **international point-to-multipoint telecommunication service via satellite** is defined as a service provided to a customer by Administrations for the transmission for example, of text, photographs or data via a satellite for the reception at a multiplicity of destinations by receive-only earth stations. + +# **2 Service description** + +## **2.1 Functional elements of service** + +A point-to-multipoint telecommunication service via satellite includes the seven following elements (see Figure 1); + +- 1) the provider(s) of information; +- 2) the link between the provider(s) and the control management centre; + +--- + +1) Multipoint-to-point and two-way multiple access services are not addressed in this Recommendation, and are subject to further study. + +- 3) the control management centre which uses various transmission means in order to collect, address, and multiplex the information from the provider(s); +- 4) the link between the command and management centre and the up link transmit earth stations; +- 5) transmit earth station(s); +- 6) the transponder of a satellite(s); +- 7) one or several receive earth stations; +- 8) the link(s) from the receive earth station(s) to the user(s) equipment. + +## **2.2 Service provision** + +The service may be provided on either a full time 24-hour basis, a scheduled part-time basis (e.g., five hours per day), or occasional use basis (e.g., a special event), subject to such terms as may be agreed between Administrations. + +## **2.3 Types of service** + +The service may be provided: + +- a) in the form of one or more analogue channels, the bandwidth of which may lie anywhere within the maximum available bandwidth of one transponder; or +- b) in the form of one or more digital channels operating at any speed within the maximum available digital capacity of one transponder. + +## **2.4 Areas of service coverage** + +The service may be provided on a regional or global basis depending on customer requirements and satellite capability. + +## **2.5 Service configurations** + +As illustrated in Figure 1, there are eight functional elements in the provision of a point-to-multipoint telecommunication service via satellite. Owing to the need for flexibility, the systems may be adapted to a diversity of needs and the regulations of each Administration involved. + +The conditions of use of the transmit (5) and receive (7) earth stations and the links (2) and (4) conveying the information flow remain a national matter to be determined by the competent authority in each country. + +The conditions of use of the space segment (6) are defined by the organizations (INTELSAT, EUTELSAT, etc.) in charge of their provision and by whatever agreements on coordination made by the competent international organizations. + +The control management centre (3) for the service may be located and/or operated with the transmit earth station, the provider of the information or independently of these two entities. + +# **3 Quality of Service** + +The efficiency of operation and therefore the Quality of Service provided to the users are linked to the relationship of all parties which contribute to the provision of the service, i.e. the technical equipment and the entities in charge of their operation. Quality of Service parameters and values are for further study based on operational experience. + +![Diagram of a satellite communication system architecture showing providers, transmissions, a control management centre, and receive earth stations.](fc46871d72c65d3381d9201646d23439_img.jpg) + +The diagram illustrates a satellite communication system architecture, divided into three main functional areas by vertical dashed lines: + +- Providers:** On the left, this section contains: + - (1) Host A and Host C, represented by rectangular blocks. + - Sub-network B, represented by a dashed oval. + - (2) Lines connecting Host A, Sub-network B, and Host C to the central processing unit. +- Transmissions:** The central area features: + - (3) A large rectangular block labeled "Protocol conversion Multiplexing Addressing Network control". + - (4) A line connecting Host C to the central block. + - (5) A "Transmit earth station(s)" icon, represented by a square with a circle inside. + - (6) A "Satellite" icon, represented by a circle with a cross inside. + - Dashed arrows showing the signal flow from the transmit earth station (5) to the satellite (6). +- Receive earth stations:** On the right, this section shows: + - (7) Three dashed ovals, each containing a receive earth station icon (square with a circle). + - (8) Each oval is connected to "User equipment", represented by a trapezoidal shape. + - Dashed arrows showing the signal flow from the satellite (6) to each of the three receive earth stations (7). + +At the bottom of the diagram, the text "T0103140-93/d01" is present in the bottom right corner. + +Diagram of a satellite communication system architecture showing providers, transmissions, a control management centre, and receive earth stations. + +FIGURE 1/F.140 + +## 3.1 Service availability + +Service availability is the ratio of aggregate time during which satisfactory or tolerable service is or could be provided, to the total observation period (Recommendation X.140, definition). + +As this availability of service depends on the class of space segment, the earth station configurations, the propagation and interference effects and the bit error ratio required, it is not possible to specify a service availability requirement for all point-to-multipoint telecommunication services via satellite. The service availability for each customer will have to be calculated on an individual case basis considering all the points mentioned above. + +# 4 Access + +## 4.1 Transmit + +The point of interconnection to the service may be located at the providers' location or on the Administrations' premises. When the point of interconnection to the service is located on the Administrations' premises, the providers' access may be via a leased circuit or a public switched network. + +## 4.2 Receive + +The receive earth station(s) may be located on the users premises or at Administrations' premises. Where the receive earth stations are located at the Administration's premises, access to the user should be via direct connection. The user of a public switched network is for further study. + +# 5 Classes of space segment + +Services offered may take account of classes of space segment available from the space segment provider(s). The following classes of space segment may be utilized to provide service: + +- a) *non-pre-emptible* – A service which may not be interrupted or terminated for the provision of a service to another customer. There are two types of non-pre-emptible service: + - 1) protected – A service for which restoration is guaranteed; and + - 2) unprotected – A service for which restoration is not guaranteed and which may only be restored subject to availability of an alternate facility; +- b) *pre-emptible* – A service which may be interrupted to provide a service of higher priority. \ No newline at end of file diff --git a/marked/F/T-REC-F.15-199208-I_PDF-E/1d7527f4316cfe2d342b08d1653d1592_img.jpg b/marked/F/T-REC-F.15-199208-I_PDF-E/1d7527f4316cfe2d342b08d1653d1592_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..28b144337a03624fa04e013d3a9efd5a0f0cc8a5 --- /dev/null +++ b/marked/F/T-REC-F.15-199208-I_PDF-E/1d7527f4316cfe2d342b08d1653d1592_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:585dd722ecc04d3d3166b4fb43f2782193f3f2ccf18e0831ebf487cf1138cba1 +size 5819 diff --git a/marked/F/T-REC-F.15-199208-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.15-199208-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..0f1539a8362b323e5bd6d36940d62645e20eab21 --- /dev/null +++ b/marked/F/T-REC-F.15-199208-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:53b38f9728e381fb51b0c45f96e9b10639de778e8b4033416d00ef085b8f75b2 +size 7462 diff --git a/marked/F/T-REC-F.15-199208-I_PDF-E/raw.md b/marked/F/T-REC-F.15-199208-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..643ca34c1aff989447a1c86a6470a94363b68bd0 --- /dev/null +++ b/marked/F/T-REC-F.15-199208-I_PDF-E/raw.md @@ -0,0 +1,146 @@ + + +![ITU logo: A globe with a lightning bolt and the letters ITU.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: A globe with a lightning bolt and the letters ITU. + +INTERNATIONAL TELECOMMUNICATION UNION + +**CCITT** + +THE INTERNATIONAL +TELEGRAPH AND TELEPHONE +CONSULTATIVE COMMITTEE + +**F.15** + +(08/92) + +**TELEGRAPH AND MOBILE SERVICES** + +**OPERATIONS AND QUALITY OF SERVICE** + +--- + +**EVALUATING THE SUCCESS +OF NEW SERVICES** + +**Recommendation F.15** + +--- + +![CCITT logo: A globe with the letters CCITT.](1d7527f4316cfe2d342b08d1653d1592_img.jpg) + +CCITT logo: A globe with the letters CCITT. + +Geneva, 1992 + +# FOREWORD + +The CCITT (the International Telegraph and Telephone Consultative Committee) is the permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988). + +Recommendation F.15 was prepared by Study Group I and was approved under the Resolution No. 2 procedure on the 4th of August 1992. + + + +--- + +# CCITT NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication Administration and a recognized private operating agency. + +# **EVALUATING THE SUCCESS OF NEW SERVICES** + +(1992) + +## **1 Introduction** + +This Recommendation provides guidance on the factors which should be taken into account in assessing the probability of success of new services which Administrations may be considering for introduction. Such a determination will permit Administrations to be more responsive to customers' growing and changing needs, and will also permit Administrations to plan the necessary network facilities and capacities which the new service may require. + +*Note* – Guidance on forecasting new services for traffic engineering purposes may be found in Recommendation E.508. + +## **2 Market research** + +Market research is a valuable tool which should be used for new services or for services for which there is no historical demand data. This research may employ questionnaires, market analysis, focus groups and interviews. Its purpose is to determine customers' intentions to purchase or use a new service, customers' attitudes towards new or existing services, price sensitivity and cross-service elasticities. Market research helps to identify customers' needs for innovative services and the likely success of new service offerings. Market research will help to avoid the pitfall of offering new services which are developed largely on the basis of the capabilities of the new technologies, without a clear understanding of customers' needs. + +## **3 Factors affecting the successful offering of new services** + +The following are some important factors which should be analysed and taken into account when assessing the chances for the success of a new service offering. + +### **3.1 Customer-oriented factors** + +#### **3.1.1 Customers' needs** + +- Strength of customers' needs (business/residence); +- degree to which the service solves customers' needs; +- availability of other solutions. + +#### **3.1.2 Human factors aspects of the service** + +- Ease of learning (learnability); +- ease of use (usability); +- extent of match with users' requirements (functionality); +- capability to satisfy needs of different categories of users (flexibility); +- benefits provided to users (usefulness); +- availability of corresponding services to others (ubiquity). + +#### **3.1.3 Customers' price sensitivity** + +- Expected limit/range of charges for the service (or package of services); +- price of alternative services; +- price/benefit relationship. + +#### **3.1.4 Customers' quality expectations** + +- Availability; +- connection speed, accuracy and clarity; + +- reliability; +- ease of problem referral; +- speed of repair; +- privacy and security; +- training and customer support. + +#### 3.1.5 *Charging and billing aspects* + +- Charging mode/method; +- charging accuracy; +- completeness and clarity of bills; +- frequency of bill presentation; +- resolution of billing disputes. + +#### 3.1.6 *Provisioning aspects* + +- Ease of placing orders; +- speed of installation; +- accommodation of special requests; +- reliability in meeting service dates. + +### 3.2 *Administration-oriented factors* + +#### 3.2.1 *Expected market size* + +- Expected number of customers – initially, long-term; +- amount of 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b/marked/F/T-REC-F.185-199806-I_PDF-E/raw.md @@ -0,0 +1,306 @@ + + +![ITU logo: A globe with a lightning bolt and the letters ITU.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: A globe with a lightning bolt and the letters ITU. + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**F.185** + +(06/98) + +SERIES F: NON-TELEPHONE TELECOMMUNICATION +SERVICES + +Telematic services – Public facsimile service + +--- + +**Internet facsimile: Guidelines for the support of +the communication of facsimile documents** + +ITU-T Recommendation F.185 + +(Previously CCITT Recommendation) + +--- + +# ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multdestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| AUDIOVISUAL SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to ITU-T List of Recommendations.* + +# **ITU-T RECOMMENDATION F.185** + +# **INTERNET FACSIMILE: GUIDELINES FOR THE SUPPORT OF THE COMMUNICATION OF FACSIMILE DOCUMENTS** + +## **Summary** + +This Recommendation describes the guidelines for the support of the communication of facsimile documents (both Group 3 and Group 4) via the Internet in real-time or store-and-forward mode. + +NOTE – Support for Group 4 is for further study. + +### **Source** + +ITU-T Recommendation F.185 was prepared by ITU-T Study Group 8 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 18th of June 1998. + +## FOREWORD + +ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +## INTELLECTUAL PROPERTY RIGHTS + +The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. + +© ITU 1998 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +## CONTENTS + +*Page* + +| | | | +|-------|-------------------------------------------------------------------|---| +| 1 | Scope..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions and abbreviations..... | 1 | +| 3.1 | Definitions ..... | 1 | +| 3.1.1 | Real-time session oriented Internet facsimile ("real-time") ..... | 1 | +| 3.1.2 | Store-and-forward facsimile..... | 1 | +| 3.1.3 | Standard facsimile terminal..... | 2 | +| 3.1.4 | Gateway ..... | 2 | +| 3.1.5 | Email client..... | 2 | +| 3.1.6 | Internet Aware Facsimile terminal (IAF)..... | 2 | +| 3.2 | Abbreviations ..... | 2 | +| 4 | Models for Internet access ..... | 2 | +| 5 | General provisions ..... | 3 | +| 5.1 | General ..... | 3 | +| 5.2 | Basic requirements ..... | 4 | +| 5.3 | Standardized options ..... | 4 | +| 6 | Network requirements..... | 4 | +| 7 | Procedures for the transmission of documents ..... | 4 | +| 8 | Coding scheme..... | 4 | + + + +# **INTERNET FACSIMILE: GUIDELINES FOR THE SUPPORT OF THE COMMUNICATION OF FACSIMILE DOCUMENTS** + +*(Geneva, 1998)* + +## **1 Scope** + +This Recommendation describes the guidelines for the support of the communication of facsimile documents (both Group 3 and Group 4) via the Internet in real-time or store-and-forward mode. + +NOTE – Support for Group 4 is for further study. + +## **2 References** + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. + +- ITU-T Recommendation T.4 (1996), *Standardization of Group 3 facsimile terminals for document transmission*. +- ITU-T Recommendation T.563 (1996), *Terminal characteristics for Group 4 facsimile apparatus*. +- ITU-T Recommendation T.37 (1998), *Procedures for the transfer of facsimile data via store-and-forward on the Internet*. +- ITU-T Recommendation T.38 (1998), *Procedures for real-time Group 3 facsimile communication over IP networks*. + +## **3 Definitions and abbreviations** + +### **3.1 Definitions** + +This Recommendation defines the following terms: + +#### **3.1.1 Real-time session oriented Internet facsimile ("real-time")** + +Real-time session oriented Internet facsimile involves the transmission/reception of a facsimile in a single session such that confirmation of receipt is provided to the transmitting terminal prior to disconnection. Real-time session oriented communication over the Internet between two facsimile terminals conforming to the relevant ITU-T Recommendations is accomplished when: + +- 1) the contents and sequence of standard messages exchanged between the sending and receiving terminals are preserved, as far as practicable; +- 2) the call duration using the Internet is comparable to that of a facsimile session using the GSTN/ISDN between the two terminals. + +This definition is valid both for terminals connected directly to the Internet and for terminals using another network for access to the Internet. + +#### **3.1.2 Store-and-forward facsimile** + +**3.1.2.1** This involves the transmission/reception of a facsimile other than in real-time. Such transmission/reception takes place via the store-and-forward mode on the Internet using Internet Email. + +**3.1.2.2** "Simple" mode store-and-forward facsimile communication over the Internet is accomplished when only the coded image is transmitted. + +**3.1.2.3** "Full" mode store-and-forward facsimile communication over the Internet between two facsimile terminals conforming to the relevant ITU-T Recommendations is accomplished when: + +- 1) the capabilities of the terminals are exchanged; +- 2) an acknowledgement of receipt is exchanged between gateways and may be transferred from the receiving terminal to the sending terminal; +- 3) the contents of standard messages used by the transmitting terminal are preserved. + +This definition is valid both for terminals connected directly to the Internet (Internet Aware Facsimile) and for terminals using another network for access to the Internet. + +#### **3.1.3 Standard facsimile terminal** + +A standard facsimile terminal is a system currently capable of sending and receiving facsimile documents in accordance with the relevant ITU-T Recommendations. Such a terminal has no capabilities to enable it to send or receive store-and-forward facsimile. A standard facsimile terminal may be connected to a gateway to provide the functionality of an Internet Aware Facsimile. + +#### **3.1.4 Gateway** + +A gateway provides access to the Internet for standard facsimile terminals. A gateway service is capable of accepting facsimile documents from, and capable of sending facsimile documents to, standard facsimile terminals. + +The responsibilities of such gateways are for further study. + +#### **3.1.5 Email client** + +An Email client is a UA capable of sending and receiving Internet Email and capable of store-and-forward facsimile. Such a client may be an Email package conforming to the relevant Internet standards and the connection to the Internet may be via a local network or via a dial-up call over the GSTN or ISDN. + +#### **3.1.6 Internet Aware Facsimile terminal (IAF)** + +For store-and-forward facsimile, an Internet Aware Facsimile terminal combines the capabilities of a standard facsimile terminal and an Email client. For real-time facsimile, an Internet Aware Facsimile terminal has the capabilities of a standard facsimile terminal as well as having an IP address or domain name together with its GSTN address. In either mode, it is capable of sending and receiving facsimile documents via the appropriate network. + +### **3.2 Abbreviations** + +This Recommendation uses the following abbreviations: + +| | | +|---------|---------------------------------------------| +| Email | Electronic Mail | +| Group 3 | Terminal conforming to Recommendation T.4 | +| Group 4 | Terminal conforming to Recommendation T.563 | +| GSTN | General Switched Telephone Network | +| IAF | Internet Aware Facsimile terminal | +| ISDN | Integrated Services Digital Network | +| UA | User Agent | + +## **4 Models for Internet access** + +The diagrams below show different methods of Internet access for PC Email clients, Internet Aware Facsimile terminals and standard facsimile terminals connected via a gateway. Such connections may be used for store-and-forward facsimile or real-time facsimile. + +Figure 1 shows the methods for store-and-forward Internet facsimile and Figure 2 shows the methods for real-time Internet facsimile. + +As an option, in case of communication difficulties with the real-time method, it is permitted to fall back to the store-and-forward mode. + +![Diagram of store-and-forward operation (T.37)](562f471e8153729557e6a4ee6343c32c_img.jpg) + +This diagram illustrates the store-and-forward operation for Internet facsimile. At the center is a diamond labeled 'The Internet'. To the left, three boxes are connected to it: 'Standard fax terminal' via a 'Gateway', 'Email client', and 'Internet Aware Fax terminal (IAF)'. To the right, the same three boxes are connected to 'The Internet' in the same manner. Arrows indicate bidirectional communication between each terminal and its respective connection point (Gateway or directly to the Internet diamond). A small code 'T0828030-98/d01' is located at the bottom right of the diagram. + +Diagram of store-and-forward operation (T.37) + +Figure 1/F.185 – Store-and-forward operation (T.37) + +![Diagram of real-time operation (T.38)](7a0db9703b68b3d06cdaeefc084c0006_img.jpg) + +This diagram illustrates the real-time operation for Internet facsimile. At the center is a diamond labeled 'The Internet'. To the left, two boxes are connected to it: 'Standard fax terminal' via a 'Gateway' and 'Internet Aware Fax terminal (IAF)' directly. To the right, the same two boxes are connected to 'The Internet' in the same manner. Arrows indicate bidirectional communication between each terminal and its respective connection point (Gateway or directly to the Internet diamond). A small code 'T0828040-98/d02' is located at the bottom right of the diagram. + +Diagram of real-time operation (T.38) + +Figure 2/F.185 – Real-time operation (T.38) + +## 5 General provisions + +### 5.1 General + +The essential characteristic of the guidelines for the support of the communication of facsimile documents over the Internet is that it provides a basic level of compatibility between all terminals supporting the capabilities. + +The communication of facsimile documents via the GSTN or ISDN has a greater level of message privacy than via the Internet. The use of security enhancements on the Internet increases the level of message privacy. + +### **5.2 Basic requirements** + +- 1) The basic level of compatibility is provided between any two terminals both nationally and internationally so that they may communicate image coded information to each other. This is to be achieved by requiring that terminals comply with the relevant ITU-T Recommendations as modified for transmission across the Internet. +- 2) It should be possible to extend the support of the communication of facsimile documents on the Internet to any number of countries. +- 3) It should enable the transport of the recipient terminal addressing information across the Internet. +- 4) To permit private use options, there shall be no technical limitation on the bit sequence of the user's information that may be transmitted. +- 5) A received Internet facsimile document can be printed or displayed as decided by the recipient and taking into account the terminal characteristics. +- 6) In the simple mode, terminal-to-terminal receipt acknowledgement need not be provided. In the full mode, terminal-to-terminal receipt acknowledgement shall be provided. +- 7) The receipt acknowledgement shall contain information to indicate successful receipt or an indication of any error. An example might be the rejection of a request to relay a store-and-forward facsimile document to a standard facsimile terminal. +- 8) It is intended that the support of communication of facsimile documents on the Internet should require no changes to the Recommendations for existing services or networks. +- 9) The intention is that the terminal's memory requirement is one page. +- 10) The intention is that the support of communication of facsimile documents on the Internet should not create additional difficulties for users, e.g. handling the reception of large volumes of unsolicited bulk advertising. + +### **5.3 Standardized options** + +It is recognized that some users may need to use their facsimile terminals to communicate nationally and internationally using features that are not included in the basic requirements. A number of ITU-T standardized options have therefore been defined. However, the provision of any option may lead to some degree of incompatibility and the number of standardized options has been restricted to those features for which a clear international need can be foreseen. + +In real-time, the sending terminal shall ensure the transmission of documents using only those options that have been indicated as being available at the receiving terminal. In the store-and-forward mode, the sending terminal shall ensure the transmission of documents using only those options that have been indicated as being available at the receiving terminal where these are known. + +## **6 Network requirements** + +- 1) The support for the communication of facsimile documents over the Internet may be provided over all public networks using the appropriate ITU-T Recommendations for the network concerned. +- 2) Terminals on any public network which support the communication of facsimile documents over the Internet shall be able to communicate automatically with any other facsimile terminals. + +## **7 Procedures for the transmission of documents** + +The technical procedures for support for the communication of facsimile documents over the Internet are given in Recommendations T.37 for store-and-forward and T.38 for real-time Group 3 documents. + +## **8 Coding scheme** + +All image coding schemes defined in the ITU-T T-series Recommendations for use with standard facsimile terminals should be supported. + +# ITU-T RECOMMENDATIONS SERIES + +| | | +|-----------------|--------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of the ITU-T | +| Series B | Means of expression: definitions, symbols, classification | +| Series C | General telecommunication statistics | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks and open system communications | +| Series Y | Global information infrastructure | +| Series Z | Programming languages | \ No newline at end of file diff --git a/marked/F/T-REC-F.2-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.2-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..f462aa76a1bd4abc43e71c76fb2d758330d8e893 --- /dev/null +++ b/marked/F/T-REC-F.2-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:b69fbf51a775dd9a6d6f1a54889692b863303e635a263d2ff12b4e9196beb36b +size 7452 diff --git a/marked/F/T-REC-F.20-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.20-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..64672153e39c851d9e16fdbc702e526c7ba7e8a7 --- /dev/null +++ b/marked/F/T-REC-F.20-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:454a9958ffe168868cb7d38a0eb24418dafe31a7a4245c992089b2316ac37d3e +size 7392 diff --git a/marked/F/T-REC-F.20-198811-I_PDF-E/raw.md b/marked/F/T-REC-F.20-198811-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..0b91f6ec7802513c6a2d437e4840696fda206b26 --- /dev/null +++ b/marked/F/T-REC-F.20-198811-I_PDF-E/raw.md @@ -0,0 +1,179 @@ + + +![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +The logo of the International Telecommunication Union (ITU) features the letters 'ITU' in a bold, sans-serif font, superimposed on a stylized globe with latitude and longitude lines. A lightning bolt symbol is positioned to the right of the letters. + +ITU logo + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +**F.20** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**OPERATIONS AND QUALITY OF SERVICE +TELEGRAPH SERVICES** + +--- + +**THE INTERNATIONAL GENTEX SERVICE** + +**ITU-T Recommendation F.20** + +(Extract from the *Blue Book*) + +--- + +# NOTES + +1 ITU-T Recommendation F.20 was published in Fascicle II.4 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below). + +2 In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +## **THE INTERNATIONAL GENTEX SERVICE** + +The CCITT, + +*unanimously declares* + +- (1) that the following provisions should be adopted for the gentex service; +- (2) that Administrations should make arrangements for their offices to apply these provisions. + +### **1 General** + +- 1.1 The gentex network is made up of telegraph offices, switching centres and telegraph channels, interconnecting the offices to switching centres and the switching centres to each other. +- 1.2 The gentex network is operated by fully automatic switching. +- 1.3 Gentex signalling shall be in accordance with CCITT Recommendations relative to telegraph switching technique. + +### **2 Call-numbers and answer-back codes** + +- 2.1 Unless other arrangements are made, the call-number dialled by a gentex office to call a gentex office in another country is made up of: + - the prefix giving access to the called country from the calling country; + - the call-number of the called office, which must comprise figures only, up to a maximum of 8 figures; the call from the national network or another number especially selected for the purpose. +- 2.2 The answer-back codes of the equipment used in the gentex service are made up of 20 signals. +- 2.3 The composition of answer-back codes shall be in accordance with the provisions of Recommendation F.21. + +### **3 Equipment of positions in telegraph offices** + +- 3.1 Transmitting or receiving positions in the gentex service shall be equipped with tape-printing or page-printing teleprinters using International Telegraph Alphabet No. 2, possessing an answer-back unit and able to work, if necessary, in simplex. +- 3.2 Positions shall be equipped for the following: + - the setting-up of calls; + - the clearing of calls; + - reception of the bell (figure J) signal; + - an alarm or transmission of the clearing signal if the paper runs out. +- 3.3 As far as possible, these positions shall also be equipped to signal the following: + - equipment out of service; + - tape broken; + - faulty tape feed. +- 3.4 In an office, the positions used in the gentex service can be grouped into those specializing in transmission and those specializing in reception. Administrations shall arrange this specialization so that the incoming grade of service shall not be less than the CCITT recommended limits. + +3.5 Both-way and incoming-only positions in the same office shall all have a common call-number. When one of these positions is engaged or faulty, a call arriving at that office shall be directed to a free position in the same group. + +### 4 Routing lists + +4.1 All countries taking part in the gentex service shall draw up a routing list containing information about the routing of traffic, and shall supply this list to the ITU for distribution to the other countries concerned. This list shall comprise: + +- a) the telegraph offices connected to the gentex network. The sign $\diamond$ shall precede the name of every office taking part in telegram transmission only, but available for a direct call when service correspondence has to be exchanged; +- b) offices that, while not connected, normally deal with a fair amount of international traffic. + +4.2 Routing lists should be of the A4 size (210 × 297 mm) and should contain the following information: + +- a) in the first column, the alphabetical list of the offices chosen in accordance with § 4.1 above (names of telegraph offices connected to the gentex network are in heavy type); +- b) in the second column, the call-number of the gentex office to be called for routing traffic to the office shown in the first column, with no restriction sign (a space is left in this column for inserting the prefix or prefixes to obtain access to the country concerned); +- c) in the third column, the answer-back codes of the offices connected to the gentex network, or of the gentex office serving an office that is not connected to this network (without the characteristic letter or letters of the specialized receiving positions); +- d) in the fourth column, the service hours of offices connected to the gentex network or of the gentex office serving an unconnected office, or in the indication *office* which *merely transmits*; service hours are given in local time. Some office work different hours on Sundays and public holidays, in which case the column is sub-divided and a list of public holidays is given at the beginning of the list. The abbreviations used in this column have the following meanings: + +N = office permanently open (day and night), + +P = office with extended service, + +– = office closed; + +- e) in the fifth column, the name of the gentex office that should be called for alternative routing when the office given in the third column is closed, out of order or engaged. This information may also be provided in the preliminary note. + +4.3 This list shall be preceded by a preliminary note indicating the routing of telegrams to offices not mentioned in the list. + +4.4 When certain important gentex offices possess specialized positions to deal with service notes and advices, or specialized positions for the reception of fault notices, the call-numbers and answer-back codes of such positions shall appear in an annex to the routing list. + +4.5 If a gentex exchange is equipped with an automatic test-phrase transmitter (with or without distortion) the call-number of such a transmitter shall also be indicated in this annex. + +4.6 Example of the first part of a routing list and this annex appear in Tables 1/F.20 and 2/F.20 respectively. + +| Bureau télégraphique
Telegraph office | Central gentex desservant le bureau
Gentex office serving the office
Central génétex que sirve la oficina | | | Heures de service (H.E.C.)
Service hours (C.E.T.)
Horas de servicio (H.E.C.) | | | Détournement
en cas de clôture
du service,
d'occupation
ou de dérangement
du central gentex

Alternative
routing when the
gentex office
is closed, engaged
or out of order

Desviación
en caso de cierre
del servicio,
de ocupación
o de avería
de la central génétex | +|-------------------------------------------------|------------------------------------------------------------------------------------------------------------------------|---------------------|-------------------------|-------------------------------------------------------------------------------------------|-----------------|-------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| | Pré-
fixe | N°
d'appel | Indicatif | Lundi
au
Vendredi | Samedi | Dimanches
et jours
fériés | | +| | Pre-
fix | Call
No. | Answer-back code | Monday
to
Friday | Saturday | Sundays
and
holidays | | +| Oficina telegráfica | Pre-
fijo | N.º de
llamada | Distintivo | De lunes
a
viernes | Sábado | Domingos
y días
festivos | | +| 1 | 2 | 3 | | 4a | 4b | 4c | 5 | +| Aachen | | 8311 | 8311 AACHEN D | N | N | N | | +| Aalen, Wuertt | | 7411 | 7411 ULM D | N | N | N | | +| Achern, Baden | | 7511 | 7511 OFFBG D | 07-22 | 07-22 | 07-19 | 7711 FREIB D | +| Ahrensburg | | 2071 | 2071 HAMB D | N | N | N | | +| | | 2031* | 2031 HAMB D | | | | | +| Alfeld, Leine | | 9111 | 9111 HAN D | N | N | N | | +| | | 9031* | 9031 HAN D | | | | | +| Alsdorf, Rheinl | | 8311 | 8311 AACHEN D | N | N | N | | +| Alsfeld | | 4911 | 4911 FULDA D | 07-22 | 07-22 | 07-21 | 4811 GSSN D | +| Altena, Westf | | 3111 | 3111 DTMD D | N | N | N | | +| | | 3031* | 3031 DTMD D | | | | | +| Altoetting | | 5611 | 5611 TRAUN D | 07-22 | 07-20 | 07-20 | 5111 MCHN D | +| | | | | | | | 5031* MCHN D | +| Amberg, Oberpf | | 6511 | 6511 RGSB D | N | N | N | | +| Andernach | | 4411 | 4411 KBLZ D | N | N | N | | +| Ansbach, Mittelfr | | 6111 | 6111 NBG D | N | N | N | | +| | | 6031* | 6031 NBG D | | | | | +| Arnsberg, Westf | | 3811 | 3811 MESCH D | 07-22 | 07-22 | 07-22 | 3111 DTMD D | +| | | | | | | | 3031* DTMD D | +| Arolsen | | 9411 | 9411 KASSEL D | N | N | N | | +| Aschaffenburg | | 4071 | 4071 FFM D | N | N | N | | +| | | 4031* | 4031 FFM D | | | | | +| Augsburg | | 5311 | 5311 AUGSB D | N | N | N | | +| Backnang | | 7111 | 7111 STGT D | N | N | N | | +| | | 7031* | 7031 STGT D | N | N | N | | +| Bad Aibling | | 5111 | 5111 MCHN D | N | N | N | | +| | | 5031* | 5031 MCHN D | | | | | +| Bad Berleburg | | 3211 | 3211 SIEGEN D | 07-22 | 07-22 | 07-22 | 3111 DTMD D | +| | | | | | | | 3031* DTMD D | +| Bad Ems | | 4411 | 4411 KBLZ D | N | N | N | | + +\* Positions de réception avec téléimprimeurs sur page – *Receiving positions with page-printers* – Posiciones de recepción con teleimpresores en página. + +TABLE 2/F.20 + +### NUMÉROS D'APPEL DES POSITIONS SPÉCIALISÉES EN RÉP. FÉD. D'ALLEMAGNE *CALL NUMBERS OF SPECIALIZED POSITIONS IN FED. REP. OF GERMANY* NÚMEROS DE LLAMADA DE LAS POSICIONES ESPECIALIZADAS EN REP. FED. DE ALEMANIA + +| Service | Numéro d'appel | Texte des émetteurs d'indicatifs | +|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------|-----------------------------------------------------------------------------------------------| +| Service | Call Number | Text of answer-back codes | +| Servicio | Número de llamada | Texto de los transmisores de distintivo | +| 1 | 2 | 3 | +| Position de renseignement – Information position – Posición de información:
Frankfurt am Main .....
Hamburg ..... | 4058
2058 | 4058 FFM INF
2058 HAMB INF | +| Position de réception des avis de dérangement – Position for reception of faulty notices – Posición de recepción de avisos de avería:
Frankfurt am Main .....
Hamburg ..... | 4051
2051 | 4051 FFM TCHN
2051 HAMB TCHN | +| Position de mesure de la distorsion arythmique – Position for the measurement of start-stop distortion – Posición de medida de la distorsión arrítmica:
Frankfurt am Main .....
Hamburg ..... | 4054
2054 | 410961 TPRMPL
210961 TPRMPL | +| Emetteur central de texte avec distorsion – Central transmitter of text with distortion – Transmisor central de texto con distorsión:
Frankfurt am Main .....
Hamburg ..... | 4041
2041 | } pas d'émetteur d'indicatif
no answer-back code
no hay transmisor de distintivo | +| Emetteur central de texte sans distorsion – Central transmitter of text without distortion – Transmisor central de texto sin distorsión:
Frankfurt am Main .....
Hamburg ..... | 4045
2045 | | + +## 5 Telegram routing + +5.1 Telegrams to an office that, whether or not connected to the gentex network, appears in the routing list shall be routed using the call number shown in the List. + +5.2 Telegrams to an office that does not appear in the routing list shall be routed in accordance with the instructions given at the beginning of the routing list of the country in which the office is located. + +## **6 Overflow** + +6.1 Administrations may make arrangements for calls to be automatically routed to overflow positions when all the receiving positions of a called office are busy. + +## **7 Prohibition of communications with telex subscribers in other countries** + +7.1 An office connected to the gentex network shall not, under any circumstances, call a telex subscriber in another country. Where possible this prohibition shall be effected by the switching equipment. + +7.2 Arrangements should also be made to prevent telex subscribers from obtaining access to gentex offices. + +## **8 Operation of the gentex service** + +8.1 The gentex service shall be operated in accordance with provisions in Recommendation F.1. \ No newline at end of file diff --git a/marked/F/T-REC-F.21-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.21-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..64672153e39c851d9e16fdbc702e526c7ba7e8a7 --- /dev/null +++ b/marked/F/T-REC-F.21-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:454a9958ffe168868cb7d38a0eb24418dafe31a7a4245c992089b2316ac37d3e +size 7392 diff --git a/marked/F/T-REC-F.21-198811-I_PDF-E/raw.md b/marked/F/T-REC-F.21-198811-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..800dc69cb7d3a9f9c67a35668e3163dac7e842fb --- /dev/null +++ b/marked/F/T-REC-F.21-198811-I_PDF-E/raw.md @@ -0,0 +1,152 @@ + + +![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +The logo of the International Telecommunication Union (ITU) features a globe with a lightning bolt superimposed on it, and the letters 'ITU' in a bold, sans-serif font. + +ITU logo + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +**F.21** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**OPERATIONS AND QUALITY OF SERVICE +TELEGRAPH SERVICES** + +--- + +**COMPOSITION OF ANSWER - BACK CODES +FOR THE INTERNATIONAL GENTEX SERVICE** + +**ITU-T Recommendation F.21** + +(Extract from the *Blue Book*) + +--- + +# NOTES + +1 ITU-T Recommendation F.21 was published in Fascicle II.4 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below). + +2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# **COMPOSITION OF ANSWER-BACK CODES FOR THE INTERNATIONAL GENTEX SERVICE** + +The CCITT, + +*considering* + +(a) that the answer-back code sent by teleprinter equipment in the gentex service should provide as much useful information as possible for the operational services. Procedures for checking answer-back codes should be simple and speedy because the average time taken to transmit the text of a telegram in the gentex system is about one minute and this means that roughly every minute three answer-back codes have to be checked by the operator (two at the beginning of the telegram, the answer-back code of the station obtained and the answer-back code of the calling station, and one at the end: the answer-back code of the station obtained); + +(b) that the answer-back code in the international gentex service should therefore include the call-number of the office and as much of the name of this office as possible; + +(c) that it is also essential to show in the answer-back code one or two characteristic letters of the country in which the teleprinter equipment is situated, for the worst routing mistake is that of sending a telegram to the wrong country; + +(d) that Administrations may identify, by additional letters in the answer-back code, not only the office but also the nature of the position in the office (outgoing position, incoming position), or the identity of the position among all similarly specialized positions, so as to facilitate the location of any faults in the equipment or the tracing of any telegrams in dispute; + +(e) that the initial letters of the alphabet: **A, B, C**, etc., are to be used for identifying specialized outgoing positions and one of the final letters of the alphabet **Z, Y, X**, etc. for identifying specialized incoming positions. For very large offices, where groups of machines having the same specialized function, outgoing or incoming, may comprise more than 12 machines, it will be necessary to use additional specialization letters: + +**T** to indicate a position specializing in transmission; + +**R** to indicate a position specializing in reception; + +(f) that if an office that uses letters denoting specialization is also equipped with combined incoming/outgoing positions, such positions will be identified by the same specialization letter as the incoming positions; + +(g) that should outgoing or incoming groups comprise more than 26 machines, the letters **S** and **Q**, denoting outgoing or incoming specialization respectively, may be used in conjunction with the letters **T** and **R**, thus increasing the possibility of identification in a group of machines to 52; + +(h) that in the case of overflow positions, they must indicate very clearly the name of the office obtained, for this name belongs to an office other than the one called. For this purpose, the call-number of the overflow office will not appear in the answer-back code of such a position, so as to leave space for the name of the office as complete as possible and the characteristic indication **DEB**, which has been chosen to denote *overflow*; + +(i) that because machines in the gentex service can be page-printing machines, it is necessary to provide carriage-return and line-feed signals at the beginning of the answer-back code and for technical reasons the last character of the answer-back code must be the letter-shift signal, + +*unanimously declares* + +(1) that answer-back codes of machines used in the international gentex service should be made up of 20 signals; + +(2) that, for machines other than those used on positions specialized for receiving overflow traffic, the series of 20 signals in the answer-back code should, in principle, be as follows: + +- carriage-return, +- line-feed, +- figure-shift, + +- the figures of the call-number by which the office is to be called when a telegram is sent to it [in some large offices a position (or group of positions) may specialize in dealing with service advices, and in this case it is provided with a special call-number and answer-back code – see § (6) below], +- letter-shift, +- space, +- letters indicating as explicitly as possible the name of the office, +- space, +- the characteristic letters of the name of the country, in accordance with the code listed under § (9) below, +- letter-shift. + +*Note* – Some teleprinters are permanently arranged to transmit letter-shift as the first character of the answer-back. In this case the letter-shift should precede the carriage-return and will reduce the number of characters available for the name of the office by one. + +(3) that, for Administrations that wish to give the specialization and identity of the positions with which equipment is associated in large offices, the series of 20 signals in the answer-back code should be made up as follows, according to the size of such offices: + +- carriage-return, +- line-feed, +- figure-shift, +- the call number as indicated under §(2), +- letter-shift, +- one or two letters chosen in accordance with Table 1/F.21, +- space, +- the name of the office, +- space, +- the characteristic letters of the name of the country, +- letter shift; + +(4) if, in the exchanges referred to in § (3) above, combined incoming/outgoing positions are used in addition to specialized incoming or outgoing positions, the answer-back codes of these combined positions should be composed in the same way as the answer-back codes of a specialized incoming position; + +(5) The specialization letter **T** should be preferred to the letter **S**, and the letter **R** to the letter **Q**; the letters **S** and **Q** should be used only when such use is justified by the exchange equipment; + +TABLE 1/F.21 + +| Size of office | For a specialized outgoing position | For a specialized incoming position | +|----------------------------|-------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------| +| Large office | one letter from A to L | one letter from Z to O | +| Very large office | the letter T and one letter from A to Z | the letter R and one letter from A to Z | +| Exceptionally large office | the letter T or the letter S and one letter from A to Z | the letter R or the letter Q and one letter from A to Z | + +(6) that, for the positions specialized in dealing with service messages, the series of 20 signals of the answer-back code should be as follows: + +- carriage-return, +- line-feed, +- figure-shift, +- the call-number of the specialized position or group of positions, +- letter-shift, +- space, +- the name of the office, +- space, +- letters **INQ**, +- letter-shift; + +(7) that, for positions specialized in the reception of overflow traffic, the series of 20 signals in the answer-back code should be as follows: + +- carriage-return, +- line-feed, +- letter-shift, +- position identification letter(s), +- space, +- the name of the office, +- space, +- letters **DEB**, +- letter-shift; + +(8) that, if an answer-back code does not fill the 20 places available, the unused places should be filled by the necessary number of space signals between the name of the office and the country code; + +(9) that the characteristic letters of names of countries should be the same as the telex network identification code shown in the *List of Destination Indicators and Telex Network Identification Codes* [1] with the exception of the countries below, which use the characteristic letters shown: + +**CS** Czechoslovakia + +**I** Italy + +**GB** United Kingdom + +**L** Luxembourg + +# Reference + +- [1] *List of indicators for the telegram retransmission system and telex network identification codes*, ITU, Geneva. \ No newline at end of file diff --git a/marked/F/T-REC-F.23-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.23-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..64672153e39c851d9e16fdbc702e526c7ba7e8a7 --- /dev/null +++ b/marked/F/T-REC-F.23-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:454a9958ffe168868cb7d38a0eb24418dafe31a7a4245c992089b2316ac37d3e +size 7392 diff --git a/marked/F/T-REC-F.24-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.24-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..64672153e39c851d9e16fdbc702e526c7ba7e8a7 --- /dev/null +++ b/marked/F/T-REC-F.24-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:454a9958ffe168868cb7d38a0eb24418dafe31a7a4245c992089b2316ac37d3e +size 7392 diff --git a/marked/F/T-REC-F.31-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.31-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..64672153e39c851d9e16fdbc702e526c7ba7e8a7 --- /dev/null +++ b/marked/F/T-REC-F.31-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:454a9958ffe168868cb7d38a0eb24418dafe31a7a4245c992089b2316ac37d3e +size 7392 diff --git a/marked/F/T-REC-F.35-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.35-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..64672153e39c851d9e16fdbc702e526c7ba7e8a7 --- /dev/null +++ b/marked/F/T-REC-F.35-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:454a9958ffe168868cb7d38a0eb24418dafe31a7a4245c992089b2316ac37d3e +size 7392 diff --git a/marked/F/T-REC-F.35-198811-I_PDF-E/raw.md b/marked/F/T-REC-F.35-198811-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..ec86114aa2a555e434433505269f207af7a38be2 --- /dev/null +++ b/marked/F/T-REC-F.35-198811-I_PDF-E/raw.md @@ -0,0 +1,377 @@ + + +![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +The logo of the International Telecommunication Union (ITU) features the letters 'ITU' in a bold, sans-serif font, superimposed on a stylized globe with intersecting lines. + +ITU logo + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +**F.35** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# **OPERATIONS AND QUALITY OF SERVICE TELEGRAPH SERVICES** --- + +**PROVISIONS APPLYING TO +THE OPERATION OF AN INTERNATIONAL +PUBLIC AUTOMATIC MESSAGE SWITCHING +SERVICE FOR EQUIPMENTS UTILIZING +THE INTERNATIONAL TELEGRAPH +ALPHABET No. 2** + +**ITU-T Recommendation F.35** + +(Extract from the *Blue Book*) + +--- + +## NOTES + +1 ITU-T Recommendation F.35 was published in Fascicle II.4 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below). + +2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +## Recommendation F.35 1) + +## PROVISIONS APPLYING TO THE OPERATION OF AN INTERNATIONAL PUBLIC AUTOMATIC MESSAGE SWITCHING SERVICE FOR EQUIPMENTS UTILIZING THE INTERNATIONAL TELEGRAPH ALPHABET No. 2 + +The existence of message switching systems in various countries creates the need for international agreement on operational rules. This service, hereafter described, can be offered by the Administration, on an international basis, following a preliminary agreement by the Administrations concerned. + +The CCITT, + +*considering* + +- (a) that message switching services are based on a technique of providing storage, routing and retransmission of messages; +- (b) that the existence of present terminals and systems utilizing the International Telegraph Alphabet No. 2 justifies the provision of a Recommendation for an automatic message switching service; +- (c) that terminals and systems in use conform to the relevant CCITT Recommendations; +- (d) that the application of operational rules in this kind of environment does not preclude the development of messaging services, unanimous declares + +*unanimously declares* + +that the following provisions should be applied when a public message switching service is being provided internationally for equipment utilizing the International Telegraph Alphabet No. 2. + +### 1 General + +1.1 The *format* to be used shall comprise a layout with the following basic components: + +- the identification line, +- the routing line, +- the origin line. +- the text. + +1.2 *Length of messages* + +As a general rule, the length of messages should not exceed 10 000 printed characters, spaces or separators. Nevertheless, Administrations may establish a different limit by bilateral agreement. + +1.3 *Sequence of signs* + +The uninterrupted repetition of any sign shall be tolerated up to a number of characters corresponding to a printed line varying in length according to the mode of operation used. Beyond this limit, the message shall be refused; subsequent signs forming part of the repetition shall be ignored. + +--- + +1) Formerly numbered F.150 in the Red Book. + +#### 1.4 *Routing* + +Messages shall be routed on circuits and systems in accordance with arrangements and modalities agreed between the Administrations concerned. + +As a rule, each system shall only receive messages for direct retransmission to national users. + +When difficulties arise in this routing, only the standby circuits and systems previously designated as such shall be brought into use. If, however, the standby equipments previously agreed upon prove to be inadequate owing to the special nature of the difficulty, the traffic may be routed on other circuits or systems with the prior agreement of the Administrations concerned or of instances appointed by them for the purpose. + +To avoid critical obstruction of the system or systems used for emergency routing, traffic cannot be deviated until the agreement of the Administrations concerned has been obtained; any restrictions placed on the deviation must be observed. + +#### 1.5 *Service traffic* + +Service traffic exchanged through a system must conform with the example given in § 5.2. In all cases, the reference data relating to the original message must appear at the beginning of the text of the service correspondence. These data must in no case be preceded by other information. + +In cases directly concerned with interworking between systems, the service traffic must be addressed to the system itself. + +#### 1.6 *Effects of one system on another* + +Traffic between two directly interconnected systems may be affected by the following commands: + +- an order to the partner to stop and then to resume his transmission; +- a request to repeat messages; +- a request for a load position notice. + +These commands shall follow the format shown in § 5.2 and shall be addressed to the corresponding system. The first word of the text indicates the action to be taken. + +According to the degree of development of the system, the reaction may be automatic or set off by the operator. + +#### 1.7 *Overloading of systems* + +Precautions must be taken against overloading. + +The system shall signal the moment when a critical load threshold is reached, so that appropriate measures can be taken before the situation deteriorates further. + +As far as possible, the system shall complete reception of messages in progress before taking action. + +#### 1.8 *Procedure to be applied in the event of total interruption of the system* + +When the interruption is planned (maintenance), the partners shall be notified as far as possible in advance. + +When it is formally established that a sudden interruption will last longer than 2 hours, all the partners concerned shall be notified without delay and informed of the measures to be taken or, where applicable, of the application of measures planned for the provisional remedy of such system failures. + +As soon as normal operation of the system is restored, the correspondents shall be informed without delay. + +#### 1.9 *Period of preservation of archives* + +##### 1.9.1 *For automatic access* + +An automatic message retransmission system should, as far as possible, be so designed as to allow direct access, for purposes of repetition or settlement of disputes, to messages transmitted by the system for at least the past 24 hours. + +##### 1.9.2 *For deferred access* + +Archives relating to the deposit and transmission of messages shall be kept for at least 2 weeks as from the day following the deposit of the message. + +#### 1.10 *Terminals directly connected to the centre of another Administration* + +When connection to a national centre cannot be effected, a terminal may exceptionally be connected to the centre of another Administration, with the consent of the Administrations concerned. + +#### 1.11 *Tolerances* + +1.11.1 At *reception*, a system must be capable of admitting tolerances whereby recourse to human interpretation is reduced to a minimum. + +For maximum efficiency, these tolerances shall, as far as possible, be adapted to the errors most commonly encountered in operation. Nevertheless, errors liable to interfere with the routing or correct treatment of the message shall be excluded. + +Unless otherwise agreed, messages which cannot be processed, automatically or manually, and character sequences not recognized as messages shall be notified to the transmitting station by an appropriate message. This message shall be set out in the format described in § 5.2 and shall contain in the text the references of the original message (identification line) and the reason for refusal. + +1.11.2 At *transmission*, the system must strictly observe the criteria of the agreed format, irrespective of the tolerance admitted at reception. + +1.11.3 Departures from these rules may be permitted only with the consent of the Administrations concerned. + +### 2 **Message** + +The format to be used to prepare a message for transmission is as follows: + +#### 2.1 *Identification line* + +The heading of the message is formed by the identification line which comprises: + +##### 2.1.1. *Start-of-message signal (SOM)* + +This signal, normally composed of the sequence of Combinations Nos. 26, 3, 26, 3 of International Telegraph Alphabet No. 2 (ZCZC or + : + :), may vary according to the mode of operation used. It is followed by the channel serial number. + +##### 2.1.2 *Channel serial number* + +Transmission numbering shall be applied serially to each point-to-point circuit and each terminal using the switched network. The channel serial number consists of three letters characterizing the circuit (circuit indicator) or terminal used, followed by the order number of the message carried on the circuit, exchanged with the terminal. The channel serial numbers shall be followed by 001 to 999, with automatic transfer from 999 to 001 at the end of the numbering cycle. + +At each retransmission, a new channel serial number shall be inserted immediately after the start-of-message signal. The channel serial numbers shall appear in the identification line of the message in the opposite order to the one in which the message was transmitted. + +The length of the identification line must not exceed 69 printed characters. Where necessary, the penultimate channel serial number of the identification line shall be erased and replaced by a new one; the last channel serial number of the identification line shall always be retained, because it also serves as the identification group of the message. + +The identification line shall be followed by the routing line. + +#### 2.2 *Routing line* + +The routing line comprises: + +##### 2.2.1 *Priority indicator* + +The priority indicator, preceded by at least one “line change” order, consists of two letters and indicates the following four priorities: + +- QS means that the message is very urgent +- QU means that the message is urgent +- QN means that the message is normal +- QD means that the message can wait. + +Systems should be capable of identifying these four priorities at reception, but can deal with only two priorities at transmission, confusing QS with QU and QN with QD. A message containing no mention of priority or containing a mention other than the ones listed above shall be regarded as a normal message and shall be marked with the code QN at output. + +The priority indicator shall be followed by the routing indicator. + +##### 2.2.2 *Routing indicator* + +The routing indicator shall be composed of an alphanumerical group of three to seven characters agreed upon by the Administrations concerned. The signs “–” (dash) and “/” (oblique) are also admitted. + +A message may comprise up to 32 routing indicators distributed over one or more lines, each of which can designate one or more addressees. The message delivered to the addressee shall contain only the indicator which relates to him. + +The routine line is followed by the origin line. + +#### 2.3 *Origin line* + +The origin line is preceded by at least one "change of line" order, followed by the full stop sign (.). The origin line comprises: + +##### 2.3.1 *Origin indicator* + +The origin indicator is composed in accordance with the criteria set out in the first paragraph of § 2.2.2. The space between the full stop and the origin indicator is optional. + +The origin indicator may be followed by references. + +##### 2.3.2 *References* + +These references are optional and may be provided either by the sender or by the system of origin. They shall have no effect on the processing of the message. + +The length of the origin line must not exceed one printed line of 69 characters. + +The origin line shall be followed by the text. + +#### 2.4 *Text* + +Preceded by at least one “change of line” order. + +The format of the text is subject to no special criteria. With regard to the content, the “start-of-message” (SOM) and “end-of-message” (EOM) signals and specific signs or combinations not authorized by a given mode of operation (cf. the relevant sections) shall not be used. + +The text is followed by the end-of-message signal (EOM). + +#### 2.5 *End-of-message signal (EOM)* + +This signal, preceded by at least one “change of line” order, is normally composed of the sequence of combinations No. 14, 14, 14, 14 of International Telegraph Alphabet No. 2 (NNNN or ,,,,). This signal may, however, vary according to the mode of operation used. + +#### 2.6 The format to be used to prepare a *service message* is the same as that stipulated for an ordinary message (see §§ 2.1 to 2.5). + +Comments and orders may be expressed in the abbreviated form described below. + +An example of such a message is given in § 5.2. + +### 3 **Mode of operation on asynchronous point-to-point circuits** + +#### 3.1 *Start of message* + +Group ZCZC or + : + : indicates the start of the message (SOM). + +#### 3.2 *End of message* + +Group NNNN or ,,,, indicates the end of the message (EOM). + +#### 3.3 *Sequence of function signs* + +The combination of function signs ( $\rightarrow \leftarrow \equiv \uparrow \downarrow$ ) does not affect the analysis and treatment of the message. + +#### 3.4 *Routing of traffic* + +Messages are routed on circuits and systems in accordance with the arrangements and modalities agreed upon between the Administrations concerned. + +When two systems are connected by several circuits, the traffic shall be distributed over each usable circuit, if possible. + +#### 3.5 *Repetition of messages* + +Messages shall be repeated only at the request of the partner. There are two kinds of repetition: + +##### 3.5.1 *Repetitions in the form of service notices (retrievals)* + +These are generally used to repeat messages already completely transmitted. The channel serial number of the original transmission must appear in the service notice. + +##### 3.5.2 *Repetitions in the same form as the first transmission (rerun, put-back)* + +Messages shall be repeated in exactly the same form as the original transmission, i.e. in the same order, with the same identification and the serial number and via the same circuit. + +#### 3.6 *Specific rules for transmission* + +##### 3.6.1 *Interruption of transmission* + +After restoration of the situation, the interrupted message should, as a rule, be repeated with the same serial number. + +##### 3.6.2 *Cancellation of a message in the course of transmission* + +Any message that has begun may be cancelled by transmitting: + +ANUL NNNN + +The channel serial number shall be reassigned to the following message. + +The cancelled message shall be neither processed nor transmitted, but shall be kept in the archives. + +##### 3.6.3 *Special signs* + +Transmission of characters D, F, G and H in the form of figures and of combination No. 32 is subject to prior agreement. + +##### 3.6.4 *Tolerances* + +No tolerance shall be admitted for the transmission of messages, + +#### 3.7 *Specific rules for reception* + +##### 3.7.1 *Irregularities at reception* + +###### a) *Absence of start-of-message criterion* + +The system memorizes the signs received until it recognizes an end-of-message (EOM) sequence or until an irregularity c), d) or e) below appears. + +###### b) *Absence of end-of-message (EOM) criterion* + +This causes the message to be rejected. + +###### c) *Pause* + +A pause may be defined as a period during the reception of a message in the course of which no data signal is received. If the pause lasts longer than 30 seconds, the system rejects the message. + +###### d) *Repetition of signs* + +Repetition of signs in excess of the tolerances given in § 1.3 causes the message to be rejected. + +###### e) *Interruption of circuit* + +An interruption is equivalent to a lapse of reception time of at least one character. Appropriate measures shall be taken to avoid loss of messages. + +*Note* – Rejection of the message is held to mean the sending of a notice to the transmitting station or, where applicable, its routing to a forward transfer position (see § 1.11. 1). + +##### 3.7.2 *Special signs* + +The presence of characters F, G and H in the form of figures and of combination No. 32 shall not affect reception availability. + +As far as possible, the presence of characters D in figure case shall be admitted under the same conditions. + +##### 3.7.3 *Tolerances* + +Any tolerances that might be admitted at reception must not be liable to cause the loss, mutilation or duplication of messages. + +### 4 **Switched network mode of operation (telex)** + +The rules applicable to the establishment of calls, transmission of messages and disconnection of calls shall be those set out in Recommendation F.60. + +#### 4.1 *Start of message* + +Group ZCZC or + : + : indicates the start of the message (SOM). + +#### 4.2 *End of message* + +Group NNNN or ,,, indicates the end of the message. + +#### 4.3 *Cancellation of a message during transmission* + +Any message that has begun may be cancelled by transmitting: + +ANUL NNNN + +The two answerback codes must then be released and the channel serial number must be reassigned to the following message. + +The cancelled message shall not be processed or retransmitted, but shall be kept in the archives. + +### 5 **Examples of formats** + +#### 5.1 *Format of ordinary message* + +ZCZC PMS036 (Note 1) + +QN STOUDHF (Note 2) + +.MARSBRD 77/11 REF 132 (Note 3) + +TEXT + +NNNN + +*Note 1* – Identification line comprising the start-of-message (SOM) signal and one channel serial number. + +*Note 2* – Routing line comprising the priority and routing indicators. + +*Note 3* – Origin line comprising the indicator of origin and optional references. + +#### 5.2 *Format of service message* + +ZCZC SWF226 + +QU CENTREB + +.CENTREA + +COMMENTAIRE/COMMANDE + +NNNN \ No newline at end of file diff --git a/marked/F/T-REC-F.350-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.350-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..64672153e39c851d9e16fdbc702e526c7ba7e8a7 --- /dev/null +++ b/marked/F/T-REC-F.350-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:454a9958ffe168868cb7d38a0eb24418dafe31a7a4245c992089b2316ac37d3e +size 7392 diff --git a/marked/F/T-REC-F.350-198811-I_PDF-E/raw.md b/marked/F/T-REC-F.350-198811-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..cddb375507e59213e7d2837535ab53c2fb62cc7d --- /dev/null +++ b/marked/F/T-REC-F.350-198811-I_PDF-E/raw.md @@ -0,0 +1,72 @@ + + +![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +The logo of the International Telecommunication Union (ITU) features the letters 'ITU' in a bold, sans-serif font, superimposed on a stylized globe with intersecting lines. + +ITU logo + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +**F.350** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**OPERATIONS AND QUALITY OF SERVICE +TELEMATIC SERVICE** + +--- + +**APPLICATION OF +SERIES T RECOMMENDATIONS** + +**ITU-T Recommendation F.350** + +(Extract from the *Blue Book*) + +--- + +# NOTES + +1 ITU-T Recommendation F.350 was published in Fascicle II.5 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below). + +2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# **APPLICATION OF SERIES T RECOMMENDATIONS** + +The CCITT, + +*considering* + +- (a) that Study Group I defines the basic and optional features to be offered by the various telematic Services; +- (b) that Study Group VIII defines the mandatory technical requirements for telematic equipment; +- (c) that Study Group VIII defines also optional technical capabilities which may be included in telematic equipment; +- (d) that there is a need to define how the mandatory and optional technical requirements should be applied; + +*unanimously agrees* + +that the Series T Recommendations shall be applied in accordance with this Recommendation. + +### **1 CCITT recommended services defined in the Series F Recommendations, excluding Videotex** + +In order to ensure full end-to-end compatibility within a CCITT recommended service, equipment shall be capable of providing the mandatory technical requirements defined in the Series T Recommendations to which the Series F Service Recommendation refers. + +### **2 Optional technical capabilities** + +Where optional technical capabilities are defined in CCITT Series T Recommendations, e.g. for use as national or regional options, the equipment shall be capable also of operating in the mandatory fallback mode. This mandatory fallback mode provides the basic features required by the relevant Series F Recommendation, and hence the mandatory technical requirements are met. + +### **3 Non-standardized capabilities** + +These capabilities are not defined in CCITT Recommendations but are laid down by Administrations and/or individual manufacturers. Provision is made for the use of such non-standardized capabilities in the procedures detailed in the relevant Series T Recommendations. + +Equipment shall be capable also of operating in the mandatory fallback mode which provides the basic features required by the relevant Series F Recommendation, and hence the mandatory technical requirements are met. + +*Note 1* – The term “mandatory technical requirements” covers the “basic functions” in Recommendation T.60, the “basic capabilities” in Recommendation T.62, the “recommended standards” in Recommendation T.4 and the “standard capabilities” in Recommendation T.30. + +*Note 2* – The term “optional technical capabilities” covers the “standardized optional functions” in Recommendation T.60, the “non-basic standardized capabilities” in Recommendation T.62 and the “recognized options” in Recommendation T.4. + +*Note 3* – The term “non-standardized capabilities” covers the “optional functions” in Recommendation T.60, the “non-basic capabilities” and “private use” in Recommendation T.62 and the “non-standard capabilities” in Recommendation T.30. \ No newline at end of file diff --git a/marked/F/T-REC-F.351-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.351-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..f462aa76a1bd4abc43e71c76fb2d758330d8e893 --- /dev/null +++ b/marked/F/T-REC-F.351-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:b69fbf51a775dd9a6d6f1a54889692b863303e635a263d2ff12b4e9196beb36b +size 7452 diff --git a/marked/F/T-REC-F.351-198811-I_PDF-E/raw.md b/marked/F/T-REC-F.351-198811-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..05c5c9f96d3652aa05652356bb965492cae3e4a7 --- /dev/null +++ b/marked/F/T-REC-F.351-198811-I_PDF-E/raw.md @@ -0,0 +1,78 @@ + + +![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +The logo of the International Telecommunication Union (ITU) features the letters 'ITU' in a bold, sans-serif font, superimposed on a stylized globe with intersecting lines. + +ITU logo + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**F.351** + +# **OPERATIONS AND QUALITY OF SERVICE TELEMATIC SERVICE** + +## --- **GENERAL PRINCIPLES ON THE PRESENTATION OF TERMINAL IDENTIFICATION TO USERS OF THE TELEMATIC SERVICES** + +**ITU-T Recommendation F.351** + +(Extract from the *Blue Book*) + +--- + +## NOTES + +1 ITU-T Recommendation F.351 was published in Fascicle II.5 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below). + +2 In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +## **GENERAL PRINCIPLES ON THE PRESENTATION OF TERMINAL IDENTIFICATION TO USERS OF THE TELEMATIC SERVICES** + +The CCITT, + +*considering* + +(a) that the terminal identification (TID) in the telematic services should provide the called subscriber not only with an unambiguous identification of the calling subscriber, but also with the essential information needed to establish a call to the former; + +(b) that transfer of network addresses, terminal identifications and other session management functions are covered in Recommendations specific to individual networks and telematic services; + +(c) that detailed provisions on TIDs and network addresses may be also found in specific Telematic service and network Recommendations and no modifications are necessary to the information carried by the communications protocol; + +(d) that, from the operational viewpoint, it is acceptable for a subscriber to add selection digits to those presented in the TID, + +*recommends* + +that the following general principles on the identification of terminals in the telematic services (and, as appropriate, other terminals) should be applied to all new equipment, and to all existing equipment1). + +**1** The TID for telematic on the PSTN shall precede the telephone country code with the escape code "9". + +**2** The TID for telematic terminals on the ISDN shall precede the country code with the escape code "0". + +**3** Table 1/F.351 shows examples of TIDs for telematic terminals on the CSPDN, PSPDN, PSTN and ISDN. The table also includes the dialling sequences from a terminal on one type of network to terminals on other types of networks. + +It should be noted that it may be necessary to instruct users NOT to dial the escape code "9" for calls from PSTN and ISDN to PSTN, and "0" from PSTN and ISDN to ISDN. + +--- + +1) The applicability of TID concept for existing G2/G3 terminals is not mandatory. In new G3 terminals the possibility to implement TID is to be encouraged. + +TABLE 1/F.351 + +| Sink | | Country B | | | | | +|-----------|-----------------------------------------------------|-----------|----------------------------|------------------------|-----------------------------|-----------------------------| +| Source | | Network | CSPDN
(e.g. Canada) | PSPDN
(e.g. Canada) | PSTN
(e.g. France) | ISDN
(e.g. France) | +| | | TID | 3029-1234567 = ABC | 3028-1234567 = DEF | 933-1234567890 = GHI | 033-123456789 = IKL | +| Country A | Dialling
information to
reach subscriber
B | CSPDN | + 3029-1234567
(Note 1) | + 3028-1234567 | + 933-1234567890 | + 033-1234567890 | +| | | PSPDN | + 3029-1234567 | + 3028-1234567 | + 933-1234567890 | + 033-1234567890 | +| | | PSTN | + 3029-1234567 | + 3028-1234567 | + 33-1234567890
(Note 2) | + 33-1234567890
(Note 2) | +| | | ISDN | + 3029-1234567 | + 3028-1234567 | + 33-1234567890
(Note 2) | + 33-1234567890
(Note 2) | + +Note 1 – The + signifies national escape digit(s) requirement. + +Note 2 – On calls from PSTN to PSTN and ISDN, and from ISDN to PSTN and ISDN the escape codes “9” and “0” may not be acceptable to the national PSTN and ISDN. \ No newline at end of file diff --git a/marked/F/T-REC-F.353-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.353-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..fd6d37344e1dcb73e876a09f0e28fcc3cc12e0bf --- /dev/null +++ b/marked/F/T-REC-F.353-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:473a66f8b6837745a7f32ac1741f274c5a10ec4eec34cbcf59ae9cab1ea41190 +size 7270 diff --git a/marked/F/T-REC-F.4-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.4-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..64672153e39c851d9e16fdbc702e526c7ba7e8a7 --- /dev/null +++ b/marked/F/T-REC-F.4-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:454a9958ffe168868cb7d38a0eb24418dafe31a7a4245c992089b2316ac37d3e +size 7392 diff --git a/marked/F/T-REC-F.40-199103-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.40-199103-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b18c639168dc459f3285497ea86c064720e780b9 --- /dev/null +++ b/marked/F/T-REC-F.40-199103-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5b32b8355fc8ffbc0ab8de83d606fef6cc42ce78b4b1b9a8332f41c6c890062e +size 7583 diff --git a/marked/F/T-REC-F.40-199103-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg b/marked/F/T-REC-F.40-199103-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..643f697dac967e79990ae8b50abf93a456bef14d --- /dev/null +++ b/marked/F/T-REC-F.40-199103-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5f1cfe9f437b942b2e54a22c10ef3208e8cdd4106f738830a966c148f7dd8cba +size 5790 diff --git a/marked/F/T-REC-F.40-199103-I_PDF-E/e0ebcd8fdcfd34b12de3601b59505fdd_img.jpg b/marked/F/T-REC-F.40-199103-I_PDF-E/e0ebcd8fdcfd34b12de3601b59505fdd_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..64a1d5a0389dc54c78aee8fad01e8243fc897908 --- /dev/null +++ b/marked/F/T-REC-F.40-199103-I_PDF-E/e0ebcd8fdcfd34b12de3601b59505fdd_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:0ca119e8c83e8fe8c378dd36b708d90b942b42b3c0c2dbbf29d8f476a80a1c2c +size 7148 diff --git a/marked/F/T-REC-F.40-199103-I_PDF-E/raw.md b/marked/F/T-REC-F.40-199103-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..adf1a37509d5a6b716ed549b064e5d5bdd8825bc --- /dev/null +++ b/marked/F/T-REC-F.40-199103-I_PDF-E/raw.md @@ -0,0 +1,456 @@ + + +![ITU logo: A globe with a lightning bolt and the letters ITU.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: A globe with a lightning bolt and the letters ITU. + +INTERNATIONAL TELECOMMUNICATION UNION + +**CCITT** + +**F.40** + +THE INTERNATIONAL +TELEGRAPH AND TELEPHONE +CONSULTATIVE COMMITTEE + +**TELEGRAPH AND MOBILE SERVICES +OPERATIONS AND QUALITY OF SERVICE** + +--- + +**INTERNATIONAL PUBLIC +TELEMESSAGE SERVICE** + +**Recommendation F.40** + +--- + +![CCITT logo: A globe with the letters CCITT.](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +CCITT logo: A globe with the letters CCITT. + +Geneva, 1991 + +# FOREWORD + +The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988). + +Recommendation F.40 was prepared by Study Group I and was approved under the Resolution No. 2 procedure on the 11 of March 1991. + +# --- CCITT NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication Administration and a recognized private operating agency. + +## Recommendation F.40 + +# INTERNATIONAL PUBLIC TELEMESSAGE SERVICE + +# 1 Introduction + +## 1.1 *Scope* + +1.1.1 Administrations providing the international public telemessage service as a form of telecommunication in accordance with Article 4.3 c) of the International Telecommunication Regulations (Melbourne, 1988) should explicitly agree to this on the basis of this Recommendation, which contains the relevant operational provisions. + +1.1.2 The international public telemessage service may operate in parallel with, or as an alternative to, the international public telegram service. The international public telemessage service shall provide the capability of operating in conjunction with the international public telegram service in those cases where it is used as an alternative to the international public telegram service. + +1.1.3 The tariff principles for the international public telemessage service are laid down in Recommendation D.45. + +1.1.4 While this Recommendation implies an implementation related to the long established message retransmission system defined in Recommendation F.31 the telemessage service is not restricted to the F.31 based techniques. + +## 1.2 *Service definitions* + +### 1.2.1 **telemessage service** + +An international public service provided to enable the transmission of character-coded messages input electronically on national public telecommunication networks or by other means for physical delivery by a postal service (or equivalent) in the destination country, normally on the next working/business day. + +### 1.2.2 **telemessage** + +Document printed in letter style preferably including the printing of capital and small letters and delivered in a distinctive envelope designed for use with the service. A telemessage includes the address of the recipient and, where possible of the sender. + +### 1.2.3 **telemessage switching centre** + +A unit used to automatically switch international and/or national telemessage traffic. + +### 1.2.4 **national telemessage input centre** + +An office used for accepting telemessages. + +### 1.2.5 **national telemessage distribution office** + +An office used for the printing and enveloping of telemessages for subsequent entry into the mail network (or equivalent). + +### 1.2.6 **printing station** + +Equipment used to print messages in the national telemessages distribution office. The printing station shall be capable of accepting a minimum of 69 printing characters (including spaces) per line. + +## 1.3 *General operating principles* + +The telemessage service is made up of the following elements. + +### 1.3.1 *Processing/switching* + +1.3.1.1 Once the telemessage has entered the telemessage switching centre, it may be processed to ensure speed and code compatibility, then queued for switching to another point in the network or for onward transmission internationally. + +### 1.3.2 *Transmission* + +1.3.2.1 The telemessage switching centres are connected internationally as outlined in § 4. + +### 1.3.3 *National distribution and delivery* + +1.3.3.1 Telemessages are printed locally in national telemessage distribution offices, which are located to meet the quality of service criteria (see § 6). Final delivery is achieved by the ordinary mail service or other means of physical delivery. + +## 2 **Acceptance of telemessages** + +2.1 Individual Administrations will decide what methods national customers may use to lodge telemessages. However, in principle it is expected that telemessages would normally be accepted via a wide range of national subscriber service, such as telephone (including public payphones), telex, teletex, telefax, videotex and by computer inputs. + +2.2 In the basic service, the characters used in composing telemessages may initially be restricted to those available in the telegram service (Recommendations F.1, A.16 to A.18) i.e. International Telegraph Alphabet No. 2 (ITA2). Nevertheless, noting the ability to preserve the distinction between capital and small letters in ITA2 where the method of lodgement permits, customers should be encouraged to use capital and small letters, so that in the preferred case where the method of international transmission also allows it, this distinction will be preserved for delivery at destination (national matter). + +2.3 In relations where appropriate bilateral agreements exist, the following more extensive character sets should be used in lodging telemessages: + +- a) the international reference version of International Alphabet No. 5 (IA5) defined in Recommendation T.50; +- b) the Teletex basic repertoire of graphic characters defined in Recommendation T.61. + +2.4 The text and the signature of a telemessage may be written in any language. + +## 3 **Telemessage switching centres** + +3.1 A telemessage switching centre shall, in the basic service, conform to the requirements of a telegram retransmission centre as defined in Recommendation F.31 except where otherwise specified by this Recommendation. + +3.2 A telemessage switching centre must be capable of switching ITA2 as described in § 2.2 above. + +## 4 **International network requirements** + +4.1 The telemessage service may utilize by bilateral agreement: + +- i) dedicated circuits between telemessage switching centres; and/or +- ii) a public data transmission network; and/or +- iii) the public switched telephone network (or circuits allocated for DATEL services); and/or +- iv) any other network e.g. telex or Gentex. + +4.2 Coding of the character sets permitted in §§ 2.2 and 2.3 above shall be in accordance with Recommendations S.1, S.2 (ITA2), T.50 (IA5 IRV), T.61 (Teletex), or others as appropriate. + +In these cases the telemessage centres can be interconnected in accordance with the Message Handling service, Recommendation X.400-Series, or other protocols by bilateral agreement. + +4.3 In the case of transmission in ITA2, distinction between capital and small letters should be retained wherever possible using the coding convention defined for this purpose in Recommendation S.2. This implies that telemessage switching centres (including transit centres) should not delete possible superfluous shift characters, although this is permissible if three or more of them appear in succession. + +4.4 The international connection between switching centres may, by bilateral agreement, operate at any modulation rate. + +## 5 Format + +## 5.1 General + +5.1.1 In the basic service, telemessages shall be transmitted in a format in conformance with Recommendation F.31 (Telegram retransmission system), except that the specific provisions below shall apply. Format examples in ITA2 and IA5 are given at Annex A. + +## 5.2 Message header + +5.2.1 The pilot line shall include, apart from the destination and origin indicators as specified in Recommendation F.1 and the number of actual words, the priority indicator C and the tariff indicator T. + +5.2.2 The actual word count shall include all the words in the text, the signature (if any) and the sender's address (if any). Consequently, the delivery address and the service indication line (if any) are excluded. + +5.2.3 The preamble line shall include the office of origin (as specified in Recommendation F.1), the actual word count, date and legal time of acceptance. + +## 5.3 Address part + +### 5.3.1 Service indications + +In relations where the telegram and telemessage services share common facilities, the first line of the address part shall begin with the service indication TELEMESSAGE1). The only optional service indication is LXx which designates de luxe cards (see § 9.1). This indication has to be separated by a space character from the indication TELEMESSAGE. + +### 5.3.2 Postal address + +5.3.2.1 The postal address must include all reasonable requirements for delivery without any enquiries in the destination country. Wherever possible the postal code should be included. In some cases a country code may be added to the postal code. Even where this is not the case, the destination country should not be shown in the address. + +5.3.2.2 The postal address will be composed preferably of six lines of up to 30 printing/spacing characters each. In some cases (e.g. in relations where the telegram and telemessage services share common facilities) a postal address of five lines of up to 43 characters each shall be accepted. + +5.3.2.3 The last line, or at most the last two lines, of the address will be used in many cases to switch the telemessage to the appropriate national distribution office. Accordingly, it (or they) shall consist of the following elements: + +--- + +1) The word "TELEMESSAGE" may not be printed (national matter). + +- wherever possible the postal code (which may contain letters and/or figures in any order); +- the name of the town or city in a form acceptable to the destination country, which may accept more than one version (e.g. LONDON, LONDRES); +- the name (*or an accepted abbreviation*) of the state, province or county (if applicable). + +5.3.2.4 The position of the postal code should be in accordance with the requirements of the destination country. + +5.3.2.5 Where practicable and convenient, the town or city name should also appear in the last line of the address, preceding the state/province/county name. Otherwise it should be given on its own in the second last line of the address. + +5.3.2.6 The relevant list of telegraph offices may be consulted when composing the address. + +## 5.4 *The text and signature* + +5.4.1 The text and signature (if any) of any one telemessage shall not exceed 35 lines, including blank lines for paragraphing and separating the signature from the text. The number of text and signature (if any) lines can exceed 35 by bilateral agreement. Each line may consist of a maximum of 69 printing/spacing characters with an option, by bilateral agreement, for 80 characters maximum providing service is not via a transit centre. + +5.4.2 The text may be freely formatted, e.g. it may include columns, separate paragraphs, etc., as might be expected in a conventional letter. In principle the text shall be transmitted in the precise format accepted from the customer. + +### 5.5 *The sender's address* + +5.5.1 The sender's address, while not obligatory, should normally follow the signature and should consist of a maximum of six lines of up to 30 printing/spacing characters each (the inclusion of the sender's address may facilitate possible service action). + +5.5.2 The last line of the sender's address should be the internationally recognized name (or abbreviation) of the country of origin. + +5.5.3 There may be an option for the date and legal time of acceptance in the country of origin to be added by the accepting Administrations on a separate line. + +## 6 **Transmission and delivery** + +6.1 International telemessages should be transmitted to the telemessage switching centre in the destination country within two hours of acceptance. + +6.2 The location of national telemessage distribution offices should be arranged to ensure that at least 95% of sufficiently addressed messages received in the destination country by 1600 hours legal time (at the destination town or locality) will be delivered on the next working/business day. + +6.3 In view of § 6.2, customers may be advised that, as a general rule, telemessages received by 1600 hours at the destination will be delivered on the next working/business day. Customers will need to take due account of any time zone differences and public holidays in the destination country. It should also be noted that, while every effort will be taken to achieve “next working day” delivery, this is not always possible for remote or sparsely populated regions, nor can any guarantee of delivery time be given in the international telemessage service. + +## 7 **Servicing procedures** + +## 7.1 *Non-delivery* + +7.1.1 If a telemessage cannot be delivered by the postal service in the destination country, due to an incorrect address, insufficient address, addressee moved, etc., the telemessage should be forwarded to the international telemessage switching centre in the destination country. + +7.1.2 When one or more telemessages are returned to that centre by the postal service, the centre shall advise the outgoing centre of the origin country. This advice should consist of a report generated each working day listing all undelivered returned telemessages and, where possible, a brief reason for nondelivery2). The recommended format is to quote in one line per message, the date of acceptance, channel sequence number and the reason for non-delivery in plain language (e.g. addressee moved). + +## 7.2 *Check of word count* + +7.2.1 No systematic check of actual word count need be performed on reception. Nevertheless, when a gross error is detected, normal service procedures in accordance with Recommendation F.1 may be used. + +## 8 Archives + +8.1 It should be possible for a telemessage to be retransmitted at the request of a destination or transit centre for a minimum period of seven days after the initial transmission. + +8.2 All outgoing messages should be stored in telemessage switching centres for a minimum period of three months to meet the requirement in Recommendation D.45, § 4.2 on justifying a refund for non-delivery. Nevertheless, to minimize operator involvement, investigations into non-delivery should be avoided as a general principle. + +8.3 Essential accounting information shall be held in archives for a minimum period of six months counted from the month after that in which the telemessage was handed in. This information shall include: + +- a) the numbering line; +- b) the office of origin; +- c) date and time of acceptance; +- d) brief identification of the address (e.g. addressee's name and country); +- e) outgoing route if necessary; +- f) time of transmission. + +## 9 Facilities + +## 9.1 *Greetings/deluxe messages* + +9.1.1 As an optional service, telemessages may be delivered with a greetings/deluxe card, preferably in a range of designs to suit a number of different occasions. The first line of the address part shall contain the service indication LXx. Values of x are listed below. + +When a choice is offered the following range of card types and indications is suggested, although it may be extended or modified. Specific designs chosen are the responsibility of the destination Administration. + +- 11 General Greetings +- 22 Weddings +- 33 Adult Greetings +- 44 Child Greetings +- 55 Birth +- 66 Condolences + +9.1.2 Any translation of the card indication necessary in the country of destination to effect delivery shall be performed by the terminal telemessage switching centre. + +--- + +2) When no undelivered telemessages are returned no report shall be generated. + +9.1.3 If the requested deluxe card is not available in the country of destination, it should normally be substituted by the general greetings card, with the possible exception when 66 (Condolences) has been requested. + +9.1.4 Administrations that do not admit GREETINGS/DELUXE messages listed in § 9.1.1 must let them pass in transit except in the case of suspension of service provided for in Article 20 of the Convention (Nairobi, 1982). + +## 9.2 *Cancellation* + +The facility to cancel a telemessage after it has been accepted is not offered. + +![A tall, narrow, empty rectangular box, likely a placeholder for a diagram or image.](e0ebcd8fdcfd34b12de3601b59505fdd_img.jpg) + +A tall, narrow, empty rectangular box with a black border, oriented vertically. It appears to be a placeholder for a diagram or image that is not visible in this version of the document. + +A tall, narrow, empty rectangular box, likely a placeholder for a diagram or image. + +# ANNEX A + +(to Recommendation F.40) + +## **Format examples** + +### A.1 *Standard telemessage in ITA2 with service indication* + +<≡ +ZCZC ZYX3174 DGR118 2-3170698 <≡ +GBXX CT UDNX 084 <≡ +TDMT AKRON OHIO 84 3 1605 <≡≡≡ + +TELEMESSAGE <≡ +MR P C JENKINSON <≡ +216 GREAT BADDOW STREET <≡ +WHITTON <≡ +TWICKENHAM <≡ +MIDDLESEX TW7 9RY <≡≡≡ + +WE REFER TO YOUR REQUEST FOR REPLACEMENT PARTS WITH COST FOR YOUR <≡ +DIATRON SYSTEM. WE HAVE PLEASURE IN SUBMITTING THE FOLLOWING <≡ +ESTIMATES. <≡≡≡ + +| PART NR. | AVAILABILITY | PRICE | DELIVERY <≡≡ | +|----------|--------------|---------|--------------| +| 263-471 | 61 | 273.70 | 6 weeks <≡ | +| 263-472 | 12 | 118.86 | 2 weeks <≡ | +| 1973A26 | 2 | 1316.00 | 1 month <≡ | +| 7168/A6 | N/A <≡ | | | +| 7168/A7 | 22 | 16.70 | in stock <≡≡ | + +PLEASE NOTE ALL PRICES ARE US DOLLARS CIF. WE LOOK FORWARD TO <≡ +RECEIVING YOUR ORDERS. <≡≡≡ + +HIRIAM P THURSTON <≡ +AKRON ASSOCIATES <≡ +3167 MAIN STREET <≡ +AKRON OHIO 12345 <≡ +UNITED STATES OF AMERICA <≡ +4.05 EST 3 JULY 1986 <≡≡≡≡≡≡≡≡≡≡ + +NNNN + +### A.2 *Standard telemessage in IA5 without service indication but with control characters for reformatting* + +<≡ +ZCZC ZYX3174 DGR118 2-3170698 <≡ +GBXX CT UDNX 079 <≡ +TDMT AKRON OHIO 79 3 1605 <≡≡≡ + +MR P C JENKINSON <≡ +216 GREAT BADDOW STREET <≡ +WHITTON <≡ +TWICKENHAM <≡ +MIDDLESEX TW7 9RY <≡≡≡ + +3) WE REFER TO YOUR REQUEST FOR REPLACEMENT PARTS WITH COST FOR YOUR <≡ +DIATRON SYSTEM. WE HAVE PLEASURE IN SUBMITTING THE FOLLOWING <≡ +ESTIMATES. <≡≡ + +| PART NR. | AVAILABILITY | PRICE | DELIVERY <≡≡ | +|----------|--------------|---------|--------------| +| 263-4719 | 61 | 273.70 | 6 weeks <≡ | +| 263-4720 | 12 | 118.86 | 2 weeks <≡ | +| 1973A26 | 2 | 1316.00 | 1 month <≡ | +| 7168/A6 | N/A <≡ | | | +| 7168/A7 | 22 | 16.70 | in stock <≡≡ | + +PLEASE NOTE ALL PRICES ARE US DOLLARS CIF. WE LOOK FORWARD TO <≡ +RECEIVING YOUR ORDERS. <≡≡≡ + +HIRIAM P THURSTON <≡ +AKRON ASSOCIATES <≡ + +4) <≡ +3167 MAIN STREET <≡ +AKRON OHIO 12345 <≡ +UNITED STATES OF AMERICA <≡≡≡≡≡≡≡≡≡≡ + +NNNN + +--- + +3) Indicates the IA5 control character No. 9 (FE1; horizontal tab) which could be used to mark the start of text. + +4) The IA5 control elements No. 11 (FE3, vertical tab) can be used to mark the end of signature and the start of the sender's address (if any). + +Both format effectors enable Administrations, by bilateral agreement, to reformat the message to their own output requirements. + +<≡ +ZCZC ZYX3174 DGR118 2-3170698 <≡ +GBXX CT UDNX 084 <≡ +TDMT AKRON OHIO 84 3 1605 <≡≡≡ + +MR P C JENKINSON <≡ +216 GREAT BADDOW STREET <≡ +WHITTON <≡ +TWICKENHAM <≡ +MIDDLESEX TW7 9RY <≡≡≡ + +WE REFER TO YOUR REQUEST FOR REPLACEMENT PARTS WITH COST FOR YOUR <≡ +DIATRON SYSTEM. WE HAVE PLEASURE IN SUBMITTING THE FOLLOWING <≡ +ESTIMATES. <≡≡ + +| PART NR. | AVAILABILITY | PRICE | DELIVERY <≡≡ | +|----------|--------------|---------|--------------| +| 263-4719 | 61 | 273.70 | 6 weeks <≡ | +| 263-4720 | 12 | 118.86 | 2 weeks <≡ | +| 1973A26 | 2 | 1316.00 | 1 month <≡ | +| 7168/A6 | N/A <≡ | | | +| 7168/A7 | 22 | 16.70 | in stock <≡≡ | + +PLEASE NOTE ALL PRICES ARE US DOLLARS CIF. WE LOOK FORWARD TO <≡ +RECEIVING YOUR ORDERS. <≡≡≡ + +HIRIAM P THURSTON <≡ +AKRON ASSOCIATES <≡ +3167 MAIN STREET <≡ +AKRON OHIO 12345 <≡ +UNITED STATES OF AMERICA <≡ +4.05 EST 3 JULY 1986 <≡≡≡≡≡≡≡≡≡≡ + +NNNN + +### A.4 *Standard telemessage without service indication or sender's address in ITA2* + +<= + +ZCZC LYX2314 DDN2716 1234FILT <= + +GBXX CT FRXX 026 <= + +PARIS 26 3 1729 <= + +MARIA C COSTELLO <= + +216A PERCY ROAD <= + +FILTON <= + +BRISTOL <= + +AVON BS6 7PL <= + +ON THIS YOUR DAY I WISH TO SEND YOU AND YOUR HUSBAND MY SINCERE BEST <= + +WISHES FOR A HAPPY LIFE TOGETHER. <= + +CLAUDE MALEVAL <= + +1729/3ER JUILLET 1986 <= + +NNNN + +### A.5 *Standard telemessage with service indication greetings/deluxe and without sender's address and date and time of acceptance in IA5 but with control characters for reformatting* + +<= + +ZCZC LYX2314 DDN2716 1234LOND <= + +GBXX CT FRXX 023 <= + +PARIS 23 3 1729 <= + +TELEMESSAGE 11 <= + +MARIA C COSTELLO <= + +216A PERCY ROAD <= + +FILTON 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+--- + +**INTERWORKING BETWEEN +THE TELEMESSAGE SERVICE +AND THE INTERNATIONAL PUBLIC +TELEGRAM SERVICE** + +**Recommendation F.41** + +--- + +![CCITT logo: A globe with the letters CCITT.](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +CCITT logo: A globe with the letters CCITT. + +Geneva, 1991 + +# FOREWORD + +The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988). + +Recommendation F.41 was prepared by Study Group I and was approved under the Resolution No. 2 procedure on the 11 of March 1991. + +# --- CCITT NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication Administration and a recognized private operating agency. + +# Recommendation F.41 + +# INTERWORKING BETWEEN THE TELEMESSAGE SERVICE AND THE INTERNATIONAL PUBLIC TELEGRAM SERVICE + +## 1 Introduction + +1.1 The International Telecommunication Regulations (Melbourne, 1988), Article 4.3 c), deal with the requirement to provide at least a form of telecommunication which is reasonably accessible to the public, including those who may not be subscribers to a specific telecommunication service. Traditionally the international public telegram service has been the most common means of filling this need. + +1.2 Resolution No. 6 (World Administrative Telegraph and Telephone Conference, Melbourne, 1988) resolves that provision should be made to allow continued availability of traditional services as perceived by the customer, although the communication infrastructure used to provide that service may vary. + +In continuing to provide a telegram-type service, Administrations should agree either to operate a telegram service in accordance with Recommendation F.1, a telemessage service in accordance with Recommendation F.40, both the telegram and the telemessage services, or to come to some other bilaterally agreed arrangement. + +1.3 This Recommendation defines the procedure that shall be followed for interworking between the telemessage service and the international public telegram service, where Administrations provide one service or the other and no other specific agreement has been reached. + +## 2 Basic interworking principles + +2.1 A service provider operating an international public telemessage service shall provide the capability of operating in conjunction with the international public telegram service in order to provide a replacement for ordinary private telegrams at least. + +2.2 Member Administrations will make separate operational arrangements to ensure adequate handling of **SVH**, **ETATPRIORITE**, **ETAT**, **OBS** and **RCT** messages. Such arrangements which may involve the use of the other telecommunication services (e.g. telex) are not covered by this Recommendation. + +2.3 In the absence of any other bilateral agreement, the relevant telegram operational procedures defined in Recommendation F.1 shall apply in both the telegram to telemessage and the telemessage to telegram directions, with the exceptions described in § 3 below. + +2.4 The charging and accounting principles for interworking between the telemessage service and the international telegram service will be defined in the D-Series Recommendations. + +## 3 Operational procedures + +3.1 If no other agreement exists, only F.31 format shall be used for the transmission of messages between the Administrations concerned. + +3.2 In the direction telegram to telemessage the service indication **TELEMESSAGE** and the priority/tariff indicator **CT** shall be used. + +3.3 In the same direction, special arrangement may be made for de luxe form, in which case the service indication **LXx** shall be used as specified in Recommendation F.50. No other special services or optional classes are admitted. + +3.4 In the telegram to telemessage direction, the origin Administration should be aware of the 35 text line limit per message in the telemessage service as defined in Recommendation F.40. + +3.5 In the telegram to telemessage direction the rules laid down in Recommendation F.1 for the counting of actual words shall apply, but the number of chargeable words may be omitted from the preamble line and the pilot line may show either the number of actual or chargeable words (at the discretion of the origin Administration). + +3.6 In the telemessage to telegram direction the wordcounts and their presentation shall be in accordance with Recommendation F.1. + +## **4 Service documents** + +4.1 In view of § 1.2 above Administrations should inform the Secretary-General of their method(s) of providing a telegram-type service. The Secretary-General is invited to include this information in the *General information relating to the operation of the international telegraph, data transmission and Telematic services*. \ No newline at end of file diff --git a/marked/F/T-REC-F.415-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.415-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..64672153e39c851d9e16fdbc702e526c7ba7e8a7 --- /dev/null +++ b/marked/F/T-REC-F.415-198811-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:454a9958ffe168868cb7d38a0eb24418dafe31a7a4245c992089b2316ac37d3e +size 7392 diff --git a/marked/F/T-REC-F.415-198811-I_PDF-E/2ee59e629035d641140e55f4d215b0d7_img.jpg b/marked/F/T-REC-F.415-198811-I_PDF-E/2ee59e629035d641140e55f4d215b0d7_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d4d5ad050b6e5243b3df6ecced2b56229c9085a7 --- /dev/null +++ b/marked/F/T-REC-F.415-198811-I_PDF-E/2ee59e629035d641140e55f4d215b0d7_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:10fbcb678de7cdf1aeef8e9cd4d603ccd779584644c5c83a81181dfb4ea586e9 +size 81182 diff --git a/marked/F/T-REC-F.415-198811-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg b/marked/F/T-REC-F.415-198811-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..4c76ff9fed609cc56fe68fa74fc07d1e4cf0f4b7 --- /dev/null +++ b/marked/F/T-REC-F.415-198811-I_PDF-E/4801720824e4b5e2361a5564f91cfb70_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:622dc81780606cacdc98f9af5aac7d358172b9d49677767d027314025c62efc4 +size 39932 diff --git a/marked/F/T-REC-F.415-198811-I_PDF-E/5a4e62bead259c258d069fd3663ea670_img.jpg b/marked/F/T-REC-F.415-198811-I_PDF-E/5a4e62bead259c258d069fd3663ea670_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..273d9373660aaa7e7265176898df5df31f6e96cd --- /dev/null +++ b/marked/F/T-REC-F.415-198811-I_PDF-E/5a4e62bead259c258d069fd3663ea670_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:02136eb0c7b5ac9748876f5507da9e9bfb227de13e9c718a1840060a8ec9000f +size 42433 diff --git a/marked/F/T-REC-F.415-198811-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg b/marked/F/T-REC-F.415-198811-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..4e51959cb4042fa26f3b6b40bc77a2944007cbfe --- /dev/null +++ b/marked/F/T-REC-F.415-198811-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f1ab444617ba1aff0c324ae829952384b9a0e4b776d4e56153be2f8685b269b7 +size 52562 diff --git a/marked/F/T-REC-F.415-198811-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/F/T-REC-F.415-198811-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..14d0f2c23bc2e9a4438c8963581944ae8f373468 --- /dev/null +++ b/marked/F/T-REC-F.415-198811-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5ff0b2c0b72c74ecbf5bc637c8bf4a718e704f1def44db3e0dac7cca911dc206 +size 50401 diff --git a/marked/F/T-REC-F.415-198811-I_PDF-E/raw.md b/marked/F/T-REC-F.415-198811-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..2e264bd1eed04ac09cea4f4b1284901ba7342006 --- /dev/null +++ b/marked/F/T-REC-F.415-198811-I_PDF-E/raw.md @@ -0,0 +1,623 @@ + + +![ITU logo](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +The logo of the International Telecommunication Union (ITU) features the letters 'ITU' in a bold, sans-serif font, superimposed on a stylized globe with intersecting lines. + +ITU logo + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +**F.415** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**OPERATIONS AND QUALITY OF SERVICE +MESSAGE HANDLING SERVICES** + +--- + +**MESSAGE HANDLING SERVICES: +INTERCOMMUNICATION WITH PUBLIC +PHYSICAL DELIVERY SERVICES** + +**ITU-T Recommendation F.415** + +(Extract from the *Blue Book*) + +--- + +# NOTES + +1 ITU-T Recommendation F.415 was published in Fascicle II.6 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below). + +2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# **MESSAGE HANDLING SERVICES: INTERCOMMUNICATION WITH PUBLIC PHYSICAL DELIVERY SERVICES** + +The establishment in various countries of message handling services in association with public networks creates the need to produce Recommendations covering the aspects of public message handling services. + +The CCITT, + +*considering* + +- (a) The need for public message handling services; +- (b) the strategic and commercial importance of standardization of message handling services; +- (c) the urgent need for intercommunication arrangements for existing telematic services, and other services with public message handling services; +- (d) the need for a clear distinction between the responsibilities to be allocated to service providers and those of subscribers and/or users; +- (e) the need for establishing international compatibility between different messaging systems; +- (f) the growth of the installed base of terminals and personal computers with the ability to access message handling systems; +- (g) that several F series Recommendations describe public message handling services; +- (h) that certain X and T series Recommendations cover relevant aspects of systems used for the provision of messaging services; +- (i) that there is a requirement for delivery of messages from message handling services in physical form to postal addresses; + +*unanimously declares* + +the view that the requirements specified in this Recommendation should be applied for the provision of intercommunication between public message handling services and public physical delivery services internationally. + +# **CONTENTS** + +- 1     *Introduction* +- 2     *Scope* +- 3     *Features* + - 3.1     General description + - 3.2     Application +- 4     *Physical rendition* + - 4.1     Basic rendition capabilities + - 4.2     Rendition of IPM headers + - 4.3     Additional rendition capabilities +- 5     *Naming and addressing* +- 6     *Quality of service* + - 6.1     Service objectives + - 6.2     Message status + + + +TABLE 1/F.415 + +## **MH/PD elements of service** + +| Category | Elements of service | F.400 Ref. | +|------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------| +| Physical delivery request | Requested delivery method | B.76 | +| Modes of physical transport and delivery | Ordinary mail
Special delivery
EMS (express mail service)
Counter collection
Counter collection with advice
Delivery via BureauFax service | B.53
B.81
B.28
B.16
B.17
B.23 | +| Registrations | Registered mail
Registered mail to addressee in person | B.70
B.71 | +| Physical delivery notifications | Undeliverable mail with return of physical message
Physical delivery notification by PDS
Physical delivery notification by MHS | B.91
B.58
B.57 | +| Physical forwarding | Physical forwarding allowed
Physical forwarding prohibited
Request for forwarding address | B.59
B.60
B.75 | +| Physical rendition capabilities | Basic physical rendition
Additional physical rendition | B.7
B.2 | + +The definition and classification of MH/PD elements of service are found in Recommendation F.400; base elements of service and optional user facilities are defined. Base capabilities are inherent to the MH/PD service intercommunication and have to be made available internationally by all Administrations supporting this intercommunication. Optional user facilities are selectable by the originator on a per-recipient basis. These are classified as either essential or additional. Essential optional user facilities shall be made available internationally by all Administrations. Additional optional user facilities may be made available by some Administrations for national use and internationally on the basis of bilateral agreement. + +### 3.2 *Application* + +All MH/PD elements of service apply on a per-recipient basis. + +Various combinations of elements of service are possible. For example, the elements of service category physical delivery notifications are useable with all modes of physical transport and delivery, with registrations and with physical forwarding categories. + +The elements of service submission time stamp and delivery time stamp also apply to MH/PD service intercommunication although they are not listed. These are MH elements of service whose definitions include MH/PD intercommunication. + +In all cases of physical delivery, it is highly desirable that the originator provide a postal O/R address for PD notifications to be sent by PDS, particularly when these are explicitly requested. To facilitate this, the originating UA could prompt the originator for this information or obtain it from a directory. + +Optional user facilities selectable by originating users affecting physical delivery are rendered on the physical message above the recipient's address visible through the window of the envelope to ensure that the proper handling procedures are taken in the PDS. Details of this are described in Annex B. + +In the case where the physical message cannot be delivered, it is returned to the originator, depending on the options selected and on national regulations, firstly as a vehicle to carry the non-delivery notification, and secondly to inform the originator on what has happened to the message. Notifications include undeliverable mail diagnostics as defined in Annex C. + +Where more than one notification is to be returned to the originator, these are returned together at the farthest delivery point. For example, physical forwarding and physical delivery notification are generated as a combined notification after delivery. + +Where the recipient's forwarding address is returned, based on the originator's request, it is returned in the form of a postal address, as defined in Recommendation F.401. + +The element of service additional physical rendition is meant to establish generic place holders for use under bilateral agreements and possible future standardization. + +The actual methods of physical rendition, routing, and delivery used by Administrations may vary. + +## 4 Physical rendition + +### 4.1 *Basic rendition capabilities* + +The PDAU and associated PDS provide the capabilities for rendition, routing, transport, and delivery of physical messages based on inherent and user selected facilities as defined by the elements of service. + +Details of the basic physical rendition (hard copy) process are provided in Annex B. + +### 4.2 *Rendition of IPM headers* + +In the case of IP-messages, heading information is printed on the physical message. The language selected is based on either the language indication element of service (provided that this is supported in the receiving country) or the default national language(s) of the receiving country. Originators and/or originating UAs are encouraged to specify the language. + +### 4.3 *Additional rendition capabilities* + +Additional physical rendition capabilities of the PDAU are for further study, but may be provided by Administrations on the basis of bilateral agreements. + +Possible additions include: + +- use of extended character sets; +- ability to select pre-encoded information (such as digitized logos and signatures) for rendition; +- support of other encoded information types. + +## 5 Naming and addressing + +Naming and addressing in message handling services is described in Recommendation F.400. + +For the purpose of physical delivery, the recipient of the physical message is identified by means of a postal O/R address as defined in Recommendation F.401. + +PD country name and country name would normally be identical, except in the case of transit mail. This occurs when a message is destined to a country which does not offer MH/PD service intercommunication; the message would then be routed and printed in the nearest country (or another country based on established agreements), and subsequently physically delivered to the final destination. + +A postal code is required for the routing of the MHS message to the proper PDAU. It may default to unspecified if no postal code exists. + +Two versions of postal O/R address are provided to allow: + +- a) the use of the postal address as it commonly exists (Version 1 – unformatted postal O/R address); +- b) for further automatic routing within the PDS (Version 2 – formatted postal O/R address). + +Administrations should support both versions of the Postal O/R Address, and should encourage MH users to use the Formatted Postal O/R Address (Version 2). + +Users should be made aware that sufficient address information about the recipient and final destination has to be provided in either version of the postal O/R address in order to enable the PDS to route, transport and deliver a physical message properly. + +In terms of formatted postal address attributes, these generally comprise: + +- one attribute of O/R address components; +- one attribute of physical delivery address components; and +- the required set of attributes of physical delivery office address components. + +The postal O/R address is also used to supply the postal address of the originator of a physical message. + +Examples of postal O/R addresses are provided in Appendix I. + +## 6 Quality of service + +### 6.1 Service objectives + +Administrations are responsible for providing the service requested by the originator. In the event of failure, it would be beneficial if accepted and non-delivered messages would be traceable and the originator informed. + +### 6.2 Message status + +Administrations could provide assistance to their subscribers with regards to delivery status. The extent to which provisions are made for support of status and tracing of messages is a national matter. + +### 6.3 Delivery and notification times model + +Figure 2/F.415 depicts a model of delivery and notification times relative to MH/PD service intercommunication. + +The meaning of times "Tn" in Figure 2/F.415 are defined as follows: + +*T1 = delivery time of MH message* + +- 1) Start time corresponds to the submission time stamp. +- 2) End time corresponds to the delivery time stamp. + +*T2 = delivery notification of MH message* + +- 1) Start time corresponds to the delivery time stamp. +- 2) End time corresponds to the time that the MH notification is made available to the user through the UA or MS. + +*T3 = physical delivery notification by MHS* + +- 1) Start time corresponds to the time at which the physical delivery notification by MHS has been generated. +- 2) End time corresponds to the time that the physical delivery notification by MHS is made available to the user through the UA or MS. + +*Ta = physical handling* + +- 1) Start time corresponds to the delivery time stamp. +- 2) End time corresponds to the time at which the physical message is delivered to the recipient. + +*Note* – Physical handling includes physical rendition, transport, and delivery. + +*Tb = generation of physical delivery notification by MHS* + +- 1) Start time corresponds to the time at which the physical message is delivered to the recipient. +- 2) End time corresponds to the time that the physical delivery notification by MHS is generated in the MHS. + +*Tc = physical delivery notification by PDS* + +- 1) Start time corresponds to the time at which the physical message is delivered to the recipient. +- 2) End time corresponds to the time that the physical delivery notification by PDS is delivered to the originator. + +*Note* – This time includes the generation of the physical delivery notification by PDS. + +![Sequence diagram illustrating MH/PD delivery and notification times model. The diagram shows the flow of messages and notifications between an Originator, UA/MS, MTA, MTA/PDAU, PDS, and a Recipient. Time intervals T1, T2, and T3 are marked for message delivery, while Ta, Tb, and Tc are marked for physical handling steps.](2ee59e629035d641140e55f4d215b0d7_img.jpg) + +The diagram illustrates the flow of messages and notifications between an Originator, UA/MS, MTA, MTA/PDAU, PDS, and a Recipient. The sequence of events is as follows: + +- Originator** initiates the process with **Creation of messages** (MH). +- UA/MS** performs **Submission of message** (MH) to the **MTA**. +- MTA** performs **Transfer of message** (MH) to the **MTA/PDAU**. +- MTA/PDAU** performs **Delivery of message** (MH) to the **PDS**. +- PDS** performs **Notification generation** (MH) and **Physical rendition** (PD). +- MTA/PDAU** receives **Notification delivery** (MH) from the **PDS**. +- UA/MS** receives **Notification by MHS delivery** (PD) from the **MTA/PDAU**. +- Originator** receives **Notification by PDS delivery** (PD) from the **UA/MS**. +- Recipient** receives **Notification by MHS generation** (PD) from the **MTA/PDAU**. +- MTA/PDAU** performs **Transport** (PD) and **Delivery** (PD) to the **Recipient**. + +Time intervals are indicated by vertical double-headed arrows: + +- T1**: Time for message creation and submission. +- T2**: Time for message transfer and delivery. +- T3**: Time for notification delivery by MHS. +- Ta**: Time for physical rendition. +- Tb**: Time for transport. +- Tc**: Time for delivery. + +CCITT – 0100680-89 + +Sequence diagram illustrating MH/PD delivery and notification times model. The diagram shows the flow of messages and notifications between an Originator, UA/MS, MTA, MTA/PDAU, PDS, and a Recipient. Time intervals T1, T2, and T3 are marked for message delivery, while Ta, Tb, and Tc are marked for physical handling steps. + +FIGURE 2/F.415 + +### **MH/PD delivery and notification times model** + +### 6.4 Time targets + +Time targets for MH (T1, T2, T3 in Figure 2/F.415) are specified in Recommendations F.410 and F.420. In addition, times for physical handling (Ta, Tb, Tc in Figure 2/F.415) need to be considered. These time targets are not specified in this Recommendation but could be defined in the MH/PD service profile table described in § 7. + +Time targets for physical handling are dependent on the modes of physical transport and delivery requested by the originator and on the modes offered by the destination Administration. + +### 6.5 Responsibility for messages + +From the point of view of MH/PD service intercommunication, responsibility for physical delivery starts at the point where the MTA passes the messages to the PDAU. Responsibility for messages prior to that belongs in MHS. + +Delivery through a specific PDS is a user option. If the user does not specify a certain PDS, messages are handled by the PDS associated with the MH domain. If there is more than one PDS, the traffic is routed based on administrative agreements. + +Although MH messages with incomplete physical routing data may cause problems or delays, service providers should accept such messages in at least one gateway station and arrange for further routing as appropriate. + +The MHS could check whether the requested elements of service and rendition capabilities are compatible with those offered by the destination MTA/PDAU and PDS. If this check is positive, the message is accepted by the MTA/PDAU which generates the delivery time stamp indication. This time stamp appears in the field service data as detailed in Annex B. + +### 6.6 *Handling of incompatibilities* + +If MH messages are destined for a MH/PD service which does not offer the requested elements of service, or additional capabilities, the messages should be transferred to another suitable MH/PD service in the same management domain, or in another management domain (another country in the case of transit mail), based on established agreements. + +Another method for handling incompatible messages is to replace requested additional optional elements of service and printing capabilities by the best comparable service and to inform the originator, and if necessary also the recipient, about the chosen alternatives. + +If neither of these methods of handling incompatibilities are possible the MTA/PDAU shall reject the MS message and initiate a non-delivery report. The non-delivery report shall inform the originating UA of the reasons for rejection of a message. + +## 7 **User information and support** + +When possible, the correctness and completeness of the physical routing data could be checked and flagged to the originator at origination. + +To prevent incompatible international MH messages from being sent, the international community of users should be provided with all necessary information on the service provisions of MTA/PDAUs and PDS. + +This information is to be defined in MH/PD service profile tables and is to be provided either in hard-copy form or preferably in electronic form. + +These MH/PD profile tables will contain all the information required for routing traffic as well as information concerning additional optional user facilities and time targets provided by the destination Administration. + +*Note* – The specification of the type of information to be contained in the MH/PD service profile tables is for urgent further study. + +Each Administration participating in this intercommunication should apply information required for the MH/PD service profile tables to the ITU secretariat, either directly or through the International Bureau of the UPU. All subsequent amendments should be communicated by the Administrations without delay. + +The ITU General Secretariat will publish the MH/PD service profile tables containing the information received from Administrations. Subsequent amendments are published in the ITU Operational Bulletin. + +*Note* – The use of Probe or directory enquiries for originators to obtain information on a MH/PD services prior to sending a message are for further study. + +## 8 **Network requirements** + +Provision of MH/PD services is network independent. Basic service and optional user facilities are provided independently of the type of network used for service access. + +## 9 **Tariff and accounting considerations** + +Tariff and accounting considerations applicable to the provisions of MH/PD services are for further study by CCITT and the UPU. + +The following elements of accounting components may need to be studied: + +- a basic charge component for the use of MH/PD service intercommunication (for ordinary mail delivery); +- additional charge components based on the request for optional user facilities; +- charge components based on the size of the message (number of pages) and the distance the message travels; +- charge components for the establishment and maintenance of address lists and other information which is stored on behalf of a user; +- charge components for additional physical rendition, such as the registration and storage of graphics (logo, signature). + +## ANNEX A (to Recommendation F.415) + +## **Abbreviations** + +| | | +|------|------------------------------------------------| +| EOS | Elements of Service | +| IA5 | International Alphabet 5 | +| IP | Interpersonal | +| IPM | Interpersonal Messaging | +| IRV | International Reference Version | +| ISO | International Organization for Standardization | +| ITU | International Telecommunications Union | +| MH | Message Handling | +| MHS | Message Handling Systems | +| MS | Message Store | +| MT | Message Transfer | +| MTA | Message Transfer Agent | +| O/R | Originator/Recipient | +| PD | Physical Delivery | +| PDAU | Physical Delivery Access Unit | +| PDS | Physical Delivery System | +| UA | User Agent | +| UPU | Universal Postal Union | + +*Note 1* – For a glossary of terms see Annex A of Recommendation F.400. + +*Note 2* – For references see Recommendations F.400 and F.401. + +*Note 3* – Administration is used in short form to indicate a Telecommunication Administration, a Recognized Private Operating Agency, and in the case of Message Handling Services intercommunication with Physical Delivery Services, a Postal Administration. + +## ANNEX B (to Recommendation F.415) + +## **Physical rendition details** + +### **B.1 Basic rendition capabilities** + +Messages destined for physical delivery are conveyed by the message transfer service and routed to an MTA/PDAU, the link between MHS and PDS. The MTA/PDAU provides the capabilities for the physical rendition based on the originator's message(s) and selected facilities. + +The physical message consists of a window envelope and a limited number of pages with imprinted information. Information is printed as information fields as follows: + +- letter-head information; +- indication of requested elements of service; + +- postal address of the recipient; +- text of the message; and +- service data. + +### B.2 *Printable area* + +The information is printed in vertical orientation in an area which is the common printable area of the 297 mm x 210 mm (ISO A4) and 280 mm x 216 mm (North American letter size) formats, as specified in Figure A-2/T.60 (dotted area). This area is extended by three additional lines down to the bottom edge which is easily possible with both formats. Figure B-1/F.415 shows the printable area. + +![Diagram of the printable area for ISO A4 and North American letter size formats. The diagram shows two nested rectangles. The outer rectangle represents the 'North american letter size (216 x 280 mm)' and the 'ISO A4 size (210 x 297 mm)'. The inner rectangle represents the 'Printable area'. A horizontal double-headed arrow at the top indicates 'Relative character position' with markers at 2, 8, and 79. A vertical double-headed arrow on the left indicates 'Relative line position' with markers at 5, 60, and 63. The area between the inner rectangle and the bottom of the outer rectangle is labeled 'Printable area extension'. The text 'CCITT - 0100690-89' is at the bottom right.](5a4e62bead259c258d069fd3663ea670_img.jpg) + +Diagram of the printable area for ISO A4 and North American letter size formats. The diagram shows two nested rectangles. The outer rectangle represents the 'North american letter size (216 x 280 mm)' and the 'ISO A4 size (210 x 297 mm)'. The inner rectangle represents the 'Printable area'. A horizontal double-headed arrow at the top indicates 'Relative character position' with markers at 2, 8, and 79. A vertical double-headed arrow on the left indicates 'Relative line position' with markers at 5, 60, and 63. The area between the inner rectangle and the bottom of the outer rectangle is labeled 'Printable area extension'. The text 'CCITT - 0100690-89' is at the bottom right. + +*Note* – For illustrative purposes only – not to scale. Relative positions based on 10 characters and 6 lines per inch. + +FIGURE B-1/F.415 + +**Printable area** + +### B.3 *Paper characteristics* + +The choice of an appropriate paper type is a national matter as long as the printable area can be accommodated. Information should be printed on plain light paper and on one side only. + +*Note* – Preprinted paper, e.g., with service logo, may generally be used but the imprint shall be outside the text of message field. + +### B.4 *Information fields* + +The maximum size of each field corresponds to an area occupied by a given number of lines based on 6 lines/inch (4.23 mm/line) and a given number of characters based on 10 characters/inch (2.54 mm/character). Other forms of rendition and settings are possible. + +These fields may be arranged on the pages according to national requirements. Figures B-2/F.415 and B 3/F.415 give two variations of the first page. Figure B-4/F.415 illustrates the layout of the second and following pages. + +![Diagram of a message page layout showing relative character positions (2, 8, 79) and relative line positions (6, 26, 60, 63). The layout includes a Letterhead area, EOS indication, Recipient address area (Window area), Home position, Text of message, and Service data area.](d4af765160d04ecef538e5066006dc77_img.jpg) + +The diagram illustrates the layout of a message page. At the top, a horizontal double-headed arrow indicates 'Relative character position' with markers at 2, 8, and 79. On the left, a vertical double-headed arrow indicates 'Relative line position' with markers at 6, 26, 60, and 63. The page is divided into several sections: + + +- Letterhead area (see Note 1)**: Located at the top, spanning from character position 8 to 79 and line position 6 to approximately 16. +- EOS indication**: A small box on the left side, just below the letterhead area. +- Recipient address area (Window area) (see Note 1)**: Located below the EOS indication, spanning from character position 8 to approximately 48 and line position 16 to 26. +- Home position**: Indicated by a small square at the start of the text area, at character position 8, line position 26. +- Text of message**: The main body of the page, starting at the home position and extending down to line position 60. +- Service data area**: Located at the bottom of the message text, between line positions 60 and 63. + +Diagram of a message page layout showing relative character positions (2, 8, 79) and relative line positions (6, 26, 60, 63). The layout includes a Letterhead area, EOS indication, Recipient address area (Window area), Home position, Text of message, and Service data area. + +CCITT - 0100700-89 + +*Note 1* - Area may be used for originator address. + +*Note 2* - For illustration purposes - not to scale. Relative positions based on 10 characters and 6 lines per inch. + +FIGURE B-2/F.415 + +Illustration 1 of a first page + +![Diagram of a first page layout showing relative character and line positions. The horizontal axis represents 'Relative character position' from 2 to 79. The vertical axis represents 'Relative line position' from 6 to 63. The layout includes a 'Letterhead area (see Note 1)' at the top, followed by a section containing '(see Note 1)', 'EOS indication', and 'Recipient address area (Window area)'. A 'Home position' marker is at line 26. The main 'Text of message' area follows, and a 'Service data area' is at the bottom between lines 60 and 63. The diagram is labeled 'CCITT - 0100710-89'.](af7916c89a458fdab6c3f443217388ae_img.jpg) + +Diagram of a first page layout showing relative character and line positions. The horizontal axis represents 'Relative character position' from 2 to 79. The vertical axis represents 'Relative line position' from 6 to 63. The layout includes a 'Letterhead area (see Note 1)' at the top, followed by a section containing '(see Note 1)', 'EOS indication', and 'Recipient address area (Window area)'. A 'Home position' marker is at line 26. The main 'Text of message' area follows, and a 'Service data area' is at the bottom between lines 60 and 63. The diagram is labeled 'CCITT - 0100710-89'. + +*Note 1* – Area may be used for originator address. + +*Note 2* – For illustration purposes – not to scale. Relative positions based on 10 characters and 6 lines per inch. + +FIGURE B-3/F.415 +**Illustration 2 of a first page** + +#### B.4.1 *Letter-head field* + +The letter-head field is used to present the letter head as commonly used for business letters (with logo, originator address, references etc.). The use of the letter-head field is under the control of the PDAU and not of the user. The remaining space in the letter-head field can be used by the PDAU for other data, e.g., an MH address of the originator, which might be useful for replying through MHS. + +The size of the letter-head field is limited to 6 lines of 72 characters each. The originator address (30 characters per-line) is one subfield in the letter-head field. + +In the basic mode, only graphic characters which are generated by the MTA/PDAU from protocol data can be presented. The use of photographic elements and/or prestored logos and signatures is not part of the basic mode. + +#### B.4.2 *Window area* + +The window area is the area which is fully seen through the window of the envelopes considering also the play of the physical message in the envelope. This area contains all the information required for handling and delivery of the physical message by the PDS, and remains free of all other information (no wording or extraneous matter). + +The window area may be either on the left or on the right depending on national practice. + +*Note* – The use of double window envelopes is considered a national matter. + +![Diagram illustrating the layout of the second and following pages of a message. The diagram shows a rectangular frame representing the page. At the top, a horizontal double-headed arrow labeled 'Relative character position' spans from position 2 to 79. On the left, a vertical double-headed arrow labeled 'Relative line position' spans from position 6 to 63. Inside the frame, a smaller rectangle labeled 'Home position' is at the top left. Below it, the main area is labeled 'Text of message'. At the bottom, a horizontal bar labeled 'Service data area' is shown. The text 'CCITT - 0100720-89' is at the bottom right of the frame.](4801720824e4b5e2361a5564f91cfb70_img.jpg) + +Diagram illustrating the layout of the second and following pages of a message. The diagram shows a rectangular frame representing the page. At the top, a horizontal double-headed arrow labeled 'Relative character position' spans from position 2 to 79. On the left, a vertical double-headed arrow labeled 'Relative line position' spans from position 6 to 63. Inside the frame, a smaller rectangle labeled 'Home position' is at the top left. Below it, the main area is labeled 'Text of message'. At the bottom, a horizontal bar labeled 'Service data area' is shown. The text 'CCITT - 0100720-89' is at the bottom right of the frame. + +*Note* - For illustration purposes - not to scale. Relative positions based on 10 characters and 6 lines per inch. + +FIGURE B-4/F.415 + +##### **Illustration of second and following pages** + +##### **B.4.2.1 *Elements of service indication field*** + +The elements of service indication field covers an area of 1 line comprising 30 characters. This area is to indicate all the options requested by the originator for the handling of the physical message (e.g., special delivery). + +This handling may be indicated in descriptive terms or by the use of codes. + +It may be necessary to give additional indication in a form commonly used in the PD service; for example, by affixing stickers on the envelope. This is a national matter. + +##### **B.4.2.2 *Space line field*** + +The space line field shall be free of imprinted information. The space line is essential to ensure that information above the address is to be clearly separated. + +##### **B.4.2.3 *Postal address field*** + +This postal address field contains the postal address of the recipient. It covers a field of 6 lines of 30 characters each. + +#### **B.4.3 *Text of message*** + +The text of message field is used to present the content of the message. In the case of IP-messages, this field is composed of the IPM heading and body. + +The maximum size of this field is: + +- a) on the first page, 35 lines of (72 + 5) characters each and, + +b) on the following pages, 55 lines of (72 + 5) characters each. + +*Note 1* – The text of the message is presented relative to the home position. The home position is in the first line of the field text of message and approximately 20 mm from the left paper edge (position 8). + +*Note 2* – 72 characters may be presented from position 8 to position 79 and 5 characters to the left of position 8 (positions 3 to 7). + +*Note 3* – The utilization of the extra "+5" character spaces mentioned above requires the use of backspace. + +#### B.4.4 *Service data field* + +The service data field is used to present service data, e.g., time stamps, message identifier and page numbers. This field is recommended to extend over two lines of 72 characters each. + +*Note* – The service data field may also cover more or less than 2 lines; this is considered a national matter. + +### B.5 *Control codes for inserting machines* + +Printing in position 3 to 7 is only allowed in the text of message field. In other fields, this space is reserved for bar codes controlling the enveloping process where automated paper handling equipment is used. In these cases, the bar codes could be used on all pages of the physical message. + +### B.6 *Character sets* + +The MTA/PDAU supports the use of the following encoded information types: + +- Telex; +- IA5 text, (IRV); +- Teletex. + +Support of additional encoded information types is for further study. Additional encoded information types may be used under bilateral agreements. + +It is an objective of the MH/PD service intercommunication to make the most use of electronic printers to ensure that the whole basic set of graphic characters received are rendered without ambiguity or loss of information. + +It is therefore preferred that each PDAU will at least provide for the rendition of the full basic set of graphic characters from Figure 2/T.61. + +However, it may be unavoidable that messages have to be converted into a 7-bit set such as defined in Recommendation T.50 for further processing and rendition in some countries. + +The selection of a print font is considered to be a national matter. Fonts which are commonly used in a country should be chosen. Rendition rules for the representation of the basic character set of Figure 2/T.61 are also a national matter. + +### B.7 *Code conversion* + +Conversion from telex and IA5 (IRV) to T.61 for further processing and rendition in the MTA/PDAU follows the rules given in Annex A. + +If conversion to a 7-bit encoded set is unavoidable, conversion from telex and IA5 (IRV) shall be according to Recommendation X.408. Conversion of messages received encoded in the T.61 set shall be converted in the greatest possible extent to minimize ambiguity and loss of information. + +### B.8 *Format conversion* + +The constraints of format conversion for the content of the message are as given in § B.4.3. + +These constraints define the presentation space of the X-and-Y directions as defined in Recommendation X.408. + +Folding of the lines and pages to the constraints of the PDAU is considered a loss of information according to Recommendation X.408. + +To recover from loss of information the PDAU may apply the following fallbacks: + +- If the originator's line length is greater than 72 characters, but not more than 80 characters, the messages will be printed with 12 cpi instead of 10 cpi. +- If the originator's first page length is greater than 35 lines but not more than 55 lines, the message will be printed starting on the second page (see Note). + +- In the case of IP-messages, the rendition of the IPM header is under the control of the PDAU. The user will not know the remaining number of lines on the page on which the header is printed. Thus, if the first page of the body parts fits into the remaining space, it will be printed on that same page; otherwise it will be printed on the next page (see Note). + +*Note* – Notification of the recipient that the message was started on the next page, for example by a note, is a national matter. + +Messages which are not paginated, either because pagination was not possible in the originator's text or because the originator didn't use pagination, will be folded to pages by the PDAU. + +## ANNEX C + +(to Recommendation F.415) + +## **Undeliverable mail diagnostics** + +### C.1 *Reasons related to the address* + +- Physical delivery address incorrect (does not exist). +- Physical delivery office incorrect or invalid (does not exist). +- Physical delivery address incomplete. + +### C.2 *Reasons related to the recipient* + +- Recipient unknown. +- Recipient deceased. +- Organization expired. +- Recipient refused to accept. +- Recipient did not claim. +- Recipient changed address permanently (moved), forwarding not applicable. +- Recipient changed address temporarily (on travel), forwarding not applicable. +- Recipient changed temporary address (departed), forwarding not applicable. + +### C.3 *Reasons of non-forwarding* + +- New address unknown. +- Recipient did not want forwarding. +- Originator prohibited forwarding. + +### C.4 *Reasons related to the PDAU capabilities* + +- Physical rendition not performed. +- Physical rendition attributes not supported. + +## APPENDIX I (of Recommendation F.415) + +### **Naming and addressing examples** + +### I.1 *Example 1* + +#### I.1.1 *Postal O/R address* + +| | | +|--------------------------------|-------------------------------------| +| PD country name: | DE (Germany, Federal Republic of) | +| Country Name: | DE (Germany, Federal Republic of) | +| Administration domain name: | DBP (Deutsche Bundespost) | +| PD service name: | POST | +| Postal Code: | 6000 | +| Version 1 (unformatted) | Version 2 (formatted) | +| Franz Müller | Personal name: Franz Müller | +| Rüdesheimer Str. 21 | Street address: Rüdesheimer Str. 21 | +| 6000 FRANKFURT 1 | PD office name: FRANKFURT | +| | PD office number: 1 | + +#### I.1.2 *Rendition of Postal Address* + +The following printout appears on the first page of the letter and is visible through the window of the envelope. + +Franz Müller +Rüdesheimer Str. 21 +6000 FRANKFURT 1 (see Note 1) +BUNDESREPUBLIK DEUTSCHLAND (see Note 2) + +*Note 1* – The postal code and country name will automatically be taken from the MHS routing data. + +*Note 2* – Country name is optional, except in the case of transit mail. + +### I.2 *Example 2* + +#### I.2.1 *Postal O/R address* + +| | | +|--------------------------------|-------------------------------------| +| PD country name: | CA (Canada) | +| Country name: | CA (Canada) | +| Administration domain name: | CPC (Canada Post Corporation) | +| PD service name: | EMAIL | +| Postal code: | K2E 7L9 | +| Version 1 (unformatted) | Version 2 (formatted) | +| Mr. J.Doe | Personal name: Mr. J. Doe | +| ACME Corp. | Organization name: ACME Corp. | +| 141 Anynname Avenue | Street address: 141 Anynname Avenue | +| SMALLTOWN, Ontario | PD office name: SMALLTOWN, Ontario | + +#### I.2.2 *Rendition of postal address* + +The following printout appears on the first page of the letter and is visible through the window of the envelope. + +Mr. J. Doe +ACME Corp. +141 Anynname Avenue +SMALLTOWN, Ontario +K2E 7L9 (see Note) + +*Note* – The postal code and country name will automatically be taken from the MHS routing data. \ No newline at end of file diff --git a/marked/F/T-REC-F.420-199208-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.420-199208-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..114ada82a155841895be88edabe3f0e44a987929 --- /dev/null +++ b/marked/F/T-REC-F.420-199208-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:568a956cd506c57e7ad41b63949aa3db1fabb2712aa3e4134d3c6c8f95742fb4 +size 8147 diff --git a/marked/F/T-REC-F.420-199208-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg b/marked/F/T-REC-F.420-199208-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5e43beaffa224a9a9ae3af17fec295eee8f96879 --- /dev/null +++ b/marked/F/T-REC-F.420-199208-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:56c2231c6e376b7c3775f27b40dd88548030f085a3488d6532ace5b972fcd632 +size 5980 diff --git a/marked/F/T-REC-F.420-199208-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/F/T-REC-F.420-199208-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e42195e8822a26f3e1869d336937c0e1426d04aa --- /dev/null +++ b/marked/F/T-REC-F.420-199208-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:02abec641fc42f28cb3b83172ee4ed002a22c88ad581914b35930899ba577cb8 +size 64495 diff --git a/marked/F/T-REC-F.420-199208-I_PDF-E/raw.md b/marked/F/T-REC-F.420-199208-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..8da03a60f742a7396e5598c3db8e26144d8b5887 --- /dev/null +++ b/marked/F/T-REC-F.420-199208-I_PDF-E/raw.md @@ -0,0 +1,583 @@ + + +![ITU logo: A globe with a lightning bolt and the letters ITU.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: A globe with a lightning bolt and the letters ITU. + +INTERNATIONAL TELECOMMUNICATION UNION + +**CCITT** + +THE INTERNATIONAL +TELEGRAPH AND TELEPHONE +CONSULTATIVE COMMITTEE + +**F.420** + +(08/92) + +# **MESSAGE HANDLING SERVICE OPERATIONS AND DEFINITION OF SERVICE** + +# --- **MESSAGE HANDLING SERVICES: THE PUBLIC INTERPERSONAL MESSAGING SERVICE** + +![CCITT logo: A globe with the letters CCITT.](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +CCITT logo: A globe with the letters CCITT. + +**Recommendation F.420** + +--- + +# FOREWORD + +The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988). + +Recommendation F.420 was revised by Study Group I and was approved under the Resolution No. 2 procedure on the 4th of August 1992. + +## --- CCITT NOTES + +- 1) In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication Administration and a recognized private operating agency. +- 2) A list of abbreviations used in this Recommendation can be found in Annex A. + +# **MESSAGE HANDLING SERVICES: THE PUBLIC INTERPERSONAL MESSAGING SERVICE** + +*(revised, 1992)* + +The establishment in various countries of message handling services in association with public networks creates the need to produce Recommendations covering the aspects of public message handling services. + +# **CONTENTS** + +| | | +|-------------------|----------------------------------------------------------------| +| 1 | Purpose and scope | +| 2 | IPM service | +| 3 | Types of body parts | +| 4 | Conversion between different encoded information types | +| 5 | Naming and addressing in general | +| 6 | Operation of the service | +| 7 | Quality of service | +| 8 | Tariff and accounting principles | +| 9 | Network requirements | +| 10 | User information and support | +| 11 | Use of the IPM service within CCITT-defined telematic services | +| Annex A | – Abbreviations | +| Annex B | – Subscriber access and terminal requirements | +| Appendix I | – Errata to Recommendations F.421 and F.422 | + +# **1 Purpose and scope** + +## **1.1 General** + +This Recommendation specifies the general, operational and quality of service aspects of the public international Interpersonal Messaging service. Interpersonal messaging services provided by Administrations belong to the group of telematic services defined in the F-Series Recommendations. + +This type of Message Handling service is an international telecommunication service offered by Administrations, enabling subscribers to send a message to one or more recipients and to receive messages via telecommunication networks using a combination of store-and-forward, and store-and-retrieve techniques. + +Locally provided functions, for which communication with other subscribers is not required, are not covered by CCITT Recommendations. + +The Interpersonal Messaging (IPM) service enables subscribers to request a variety of features to be performed during the handling and exchange of messages. + +Some features are inherent in the basic IPM service. Other non-basic features may be selected by the subscriber, either on a per-message basis or for an agreed contractual period of time, if they are provided by Administrations. + +Basic features have to be made available internationally by Administrations. Non-basic features, visible to the subscriber, are classified as either essential or additional. Essential optional features must be made available internationally by Administrations. Additional optional features may be made available by some Administrations for national use and internationally on the basis of bilateral agreement. Non-basic features are called *optional user facilities*. + +IPM service may be provided using any physical network. IPM service may be offered separately or in combination with various telematic or data communication services. It can be obtained by making appropriate arrangements. + +Technical specifications and protocols, to be used in the IPM service, are defined in the X.400-Series Recommendations, in Recommendation T.330 and in Recommendation U.204. + +This service definition is contained in § 2. Requirements for intercommunication between subscribers are described in §§ 3 and 4. Section 5 describes naming and addressing, while §§ 6, 7 and 8 describe the operation of the service, quality of service, tariff and accounting principles. Network requirements are given in § 9. The provision of subscriber information is in § 10, and § 11 contains information on the use of IPM service within CCITT defined telematic services. + +## 1.2 *Message handling systems used in the provision of IPM service* + +### 1.2.1 *1984 and 1992 implementations* + +This Recommendation assumes that the message handling systems implemented to provide the service outlined herein are based on the 1992 version of the X.400-Series of technical Recommendations. It is recognized however, that for some time after the publication of this Recommendation, several implementations of Message Transfer (MT) service will still be based on the 1984 X.400-Series of Recommendations. + +### 1.2.2 *1988 and 1992 implementations* + +Minor revisions between 1988 and 1992 Message Handling (MH) service Recommendations are referenced in Annex C of Recommendation F.400. All revisions introduced are classified as optional additional user facilities. The Quality of Service time targets should be supported as detailed in Recommendation F.410. + +Administrations are encouraged to adopt the latest CCITT Recommendations. + +### 1.2.3 *Interworking* + +In order to protect the investment of Administrations who have implemented previous systems for the provision of MH services, 1992 Administration management domain (ADMD) implementations shall be able to interwork to 1984 and 1988 ADMDs (see Note). Interworking from 1992 ADMDs to private management domains (PRMDs), which support previous versions is a local matter. + +*Note* – A future version of this Recommendation will make support for the interworking with 1984 ADMDs optional. + +# 2 **IPM service** + +## 2.1 *General service requirements* + +2.1.1 The fundamental ability of the IPM service is to provide a public interface between originators and recipients to enhance their means of communication especially where there is no immediate or convenient direct telecommunication service available between subscriber's equipment or the telecommunication services available are incompatible. + +This service may also provide features available for the preparation and the presentation of the messages. + +2.1.2 The IPM service will be provided by Administrations using the message transfer service defined in Recommendation F.410, and by systems that conform to the X.400-Series Recommendations. + +Management domains (MDs) are defined for the purpose of responsibility boundaries. The MD managed by an Administration is called an Administration management domain (ADMD). The MD managed by an organization is called a private management domain (PRMD). + +2.1.3 International exchange of messages are performed between Administration management domains through CCITT-standardized public data transmission services. + +2.1.4 Different body part types of messages may be exchanged through this service. The various body part types are listed in § 3. + +2.1.5 An Administration may provide subscribers with different methods of access to the IPM service. The possible methods are: + +- 1) directly from the user's terminal; +- 2) via a private message handling system. + +2.1.6 Each Administration is responsible for the national access to its management domain. + +2.1.7 The characteristics of the interfaces and access methods used between terminals and the IPM service are a national matter, although they may follow various CCITT-standardized services such as telex, teletex, facsimile, videotex or data transmission services. However, the IPM service optional user facilities offered are defined and are independent of the access method and user's terminal. + +2.1.8 The national implementation of the IPM service may provide intercommunication with existing services such as telex, teletex, facsimile and videotex. When implemented, the interfaces between the IPM and the other services shall be according to relevant CCITT Recommendations. + +2.1.9 As the service is providing indirect communication, cases of non-delivery of the message to the intended recipient may occur. The IPM service provides for non-delivery notification and, as optional user facilities, for delivery, receipt and non-receipt notifications. + +2.1.10 Due to the intermediate storage of the message, the service may provide conversion optional user facilities: speed, access procedures, networks, and coding of message contents. + +2.1.11 The message belongs to the originator until delivery has taken place. After delivery, the message belongs to the recipient. + +2.1.12 Where a sender and recipient have different and conflicting requirements, the sender's requirements shall take precedence (e.g., body type conversion or redirection control). + +## 2.2 *IPM service features* + +### 2.2.1 *Introduction* + +Recommendation F.400, § 19, defines elements of service which are available in the IPM service and are classified as either belonging to the basic service or as IPM optional user facilities. Elements of service comprising the basic IPM service are inherently part of the service and are always provided and available. The optional user facilities that are classified as essential are always provided and those classified as additional may be available nationally, or internationally on the basis of bilateral agreement. + +### 2.2.2 *Basic IPM service* + +A set of elements of service comprises the basic IPM service. This set is defined in Recommendation F.400, and listed in Table 10/F.400. The basic IPM service, which is built upon the MT service, enables a user to send and receive interpersonal (IP) messages. A user prepares IP-messages with the assistance of his user agent (UA). User agents, which are a set of computer application processes, cooperate with each other to facilitate communication + +between their respective users. To send an IP-message, the originating user makes a request of his UA, specifying the name or address of the recipient who is to receive the IP-message. The IP-message, which has an identifier conveyed with it, is then sent by the originator's UA to the recipient's UA via the Message Transfer service. + +Following a successful delivery to the recipient's UA, the IP-message can be received by the recipient. To facilitate meaningful communication, a receiving user may specify the encoded information type(s) that can be contained in IP-messages delivered to him, as well as the maximum length of a message he is willing to have delivered to him. The original encoded information type(s) and an indication of any conversions that may have been performed and the resulting encoded information type(s) are supplied with each delivered IP-messages. In addition, the submission time, delivery time and other capabilities are supplied with each IP-message. Non-delivery notification is provided with the basic service. + +### 2.2.3 *IPM optional user facilities* + +A set of the elements of services of the IPM service are optional user facilities. The optional user facilities which may be selected on a per-message basis or for an agreed contractual period of time, are listed in Tables 11/F.400 and 12/F.400, respectively. Local user facilities may be usefully provided in conjunction with some of these user facilities. + +The optional user facilities of the IPM service that are selected on a per-message basis are classified for both origination and reception by UAs. If an Administration provides the IPM service and offers these optional user facilities for origination by UAs, then a user is able to create and send IP-messages according to the procedures defined for the associated element of service. If an Administration provides the IPM service and offers these optional user facilities for reception by UAs, then the receiving UA will be able to receive and recognize the indication associated with the corresponding element of service and to inform the user of the requested optional user facility. Each optional user facility is classified as additional or essential for UAs from these two perspectives. + +*Note* – With the access protocol described in Recommendation T.330, teletex terminals are able to make use of the basic IPM service as well as of the optional user facilities provided by the Message Handling service. + +### 2.2.4 *Local functions* + +The message handling system (MHS) may perform many local functions for its subscribers in addition to providing IPM features. For example, to assist subscribers in preparing and editing IP-messages, MHS may provide an editing capability. This editor could operate on a single line of text at a time, or it could permit the display and alteration of a page at a time. A subscriber may have to access MHS frequently to determine if new messages have arrived. Alternatively, the MHS could alert the subscriber when new messages have arrived (for example, by setting a message light on his telephone, or by his displaying on his desktop terminal the originator's name and subject of all unread messages or by computer-initiated voice indication). + +The MHS may provide local database controls to help the subscriber find previously received and filed IP-messages (for example, to find the message from Mr. Jones delivered sometime in August on the subject of *teleconferencing*). A subscriber on vacation may request the MHS to automatically forward all his IP-messages to his delegate, or define rules for which IP-messages should not be auto-forwarded (for example, personal messages). + +Local services such as those above, while perhaps utilizing some of the IPM features, do not require coordination or cooperation with other subscribers. Thus, they do not impact the communication protocols associated with MHS. Therefore, local functions that may be provided by Administrations are outside the scope of CCITT. + +## 2.3 *Responsibility boundaries* + +The purpose of the MHS is to allow messages to be submitted for transfer to the destination and to be delivered to a UA/MS whose address is specified by the originator. + +A user interacts with his UA on the sending and on the receiving side. On his request, a message is submitted to the message transfer system (MTS). He is also able to retrieve a received message from his UA or message store (MS). + +The responsibility for the message rests in the MHS when the originating user gives the command to send the message. The responsibility for a message is turned over to the receiving UA/MS after successful delivery. If the UA or MS is provided by an Administration, the responsibility for the message is taken over by the user when he reads the message. + +As a basic feature, a non-delivery notification is created by the MHS when delivery to the receiving UA/MS is not possible. The conditions applied to this criteria may also depend on optional user facilities, e.g. conversion prohibition. An originating user may, for a particular message, specifically request a delivery notification, and/or a receipt notification, and/or a non-receipt notification. + +In the case of telematic and telex access units, a delivery notification is created when the message is transmitted to the receiving terminal. The responsibility of the MHS ends when the message is received by the terminal. After delivery to a document store, or a message store, responsibility turns over to the user after having read the message once. When leaving the message in the store, the responsibility will be defined by the service provider. + +Loss of information may occur through the process of conversion as long as the conversion is not explicitly prohibited by the originating user. + +The responsibility of messages transferred through MDs starts at the moment of entering the domain and ends when leaving the domain; however, a later audit must be possible. + +When an ADMD interacts with a PRMD, the ADMD takes responsibility for the actions of the PRMD which are related to the interaction. In addition to ensuring that the PRMD properly provides the MT service, the ADMD is responsible for ensuring that the accounting, logging, quality of service and other related operations of the PRMD are correctly performed. An ADMD acts as the naming authority for the associated PRMDs. + +## 2.4 *Message store* + +Administrations may optionally provide MS to permit delivery of messages so that the recipient's UA does not have to be on line continuously. This is described in Recommendation F.400, § 7.4. A message delivered to an MS is deemed delivered by MHS. Messages delivered to an MS can be retrieved by the recipient at his convenience and various optional user facilities can be provided to allow for retrieval for listing, fetching, and deletion of messages. When subscribing to an MS, all messages destined to the UA are delivered to the MS, and if the UA is on line, an alert will be sent to the UA (from the MS) to inform the user of the fact that a message just arrived. + +## 2.5 *Use of directory* + +By making use of directory systems, IPM users will be able to address recipients by using directory names or distribution list names, which are more user friendly than originator/recipient (O/R) addresses. The MHS will be able to access a directory system and find out the O/R address(es) corresponding to a given directory name or distribution list name, for delivery of a message. This capability is described in Recommendation F.400, § 14. + +## 2.6 *Security* + +Administrations may optionally provide security mechanisms as outlined in Recommendation F.400, § 15, to counter the various security threats mentioned. This capability relies on a directory system storing certified copies of public keys for MHS users. + +## 2.7 *Distribution lists* + +A group whose membership is stored in the directory can be used as a distribution list (DL). The originator simply supplies the name of the list on submission of a message, and the MHS can obtain the directory names (and then the O/R addresses) of the individual recipients, by consulting the directory. Upon receipt of a message addressed to a distribution list, the recipient can determine through which DL the message arrived. An originator can prohibit the expansion of the distribution if one of the recipients specified refers to a distribution list. Recommendation F.400, § 14, outlines the full capabilities available to DL users. + +If a user unknowingly sends a message to a DL, he may incur charges for multiple deliveries that he was not expecting. Because of this, names of distribution lists should be indicative of the fact that what is being named is a DL. Owners of DLs should also insure that they respect a potential member's wishes about being a member and the rules of the country of the member that may prohibit inclusion without prior agreement. + +## 2.8 *Intercommunication with physical delivery services* + +The intercommunication with the physical delivery (PD) services is an optional capability of the IPM service that allows for the sending of a message from an IPM user to a recipient via physical means, such as the traditional postal service. To invoke the capability, the originating user shall use the requested delivery method element of service on submission of his message, specifying physical delivery. The message may be addressed using the postal O/R address, or the directory name of the intended recipient, in which case the MHS will consult the directory system to determine the postal O/R address. The use of MH/PD service intercommunication by IPM users is described in Recommendation F.415 and Recommendation F.400, § 10. + +# 3 **Types of body parts** + +Messages sent and received in the IPM service can be composed of one or more body parts. Applicable body part types are defined in Recommendation X.420 and comprise the following: + +- International Alphabet No. 5 (IA5) text, +- voice, +- Group 3 (G3) facsimile, +- Group 4 (G4) class 1 facsimile, +- teletex, +- videotex, +- encrypted, +- message (e.g. for a forwarded message), +- mixed mode, +- bilaterally defined, +- nationally defined, +- externally defined, +- general text, +- file transfer. + +# 4 **Conversion between different encoded information types** + +The MTS provides conversion functions to allow IPM users to input messages in one encoded format, called encoded information type (EIT), and have them delivered in another EIT to cater to users with different terminal types. This capability is inherent in the IPM service, and increases the possibility of delivery by tailoring the message to the recipient's terminal capabilities. The EITs supported for the IPM service are defined in Recommendation X.420. IPM users have some control over the conversion process through various elements of service as described in Recommendation F.400, Annex B. These include the ability for a user to explicitly request the conversion required or, as a default, to let the MTS determine the need for, and type of, conversion performed. Users also have the ability to request that conversion not be performed or that conversion not be performed if loss of information will result. The definition of loss of information is given in Recommendation X.408. + +When the MTS performs conversion on a message, it informs the UA to whom the message is delivered that conversion took place and what the original EIT was. + +The conversion process for IP-messages can be performed on specific body parts if they are present in a message. The general aspects of conversion and the specific conversion rules for conversion between different EITs in the IPM service are detailed in Recommendation X.408. + +# 5 Naming and addressing in general + +In MHS, the principal entity that requires naming is the user (the originator and recipient of messages). In addition, distribution lists (DLs) have names for use in MHS. Users of MHS and DLs are identified by O/R names. O/R names are comprised of directory names and/or O/R addresses, all of which are described in this section. Recommendation F.401 provides more detail on naming and addressing for public message handling services, including naming restrictions and responsibilities of Administrations. + +## 5.1 *Directory names* + +Users of MHS service, and DLs, may be identified by a name, called a directory name. A directory name has to be looked up in a directory to find out the corresponding O/R address. The structure and components of directory names are described in the X.500-Series Recommendations. + +A user may access a directory system directly to find out the O/R address of a user or O/R addresses of the members of a DL (both of which are outside the scope of these Recommendations). As an alternative, a user may use the directory name and have the MHS access the directory to resolve the corresponding O/R address or addresses automatically. + +Every MHS user or DL will not necessarily have a directory name, unless they are registered in a directory. As directories become more prevalent, it is expected that directory names will be the preferred method of identifying MHS users to each other. + +## 5.2 *O/R names* + +Every MHS user or DL will have an O/R name. An O/R name comprises a directory name, an O/R address, or both. The directory name unambiguously identifies an MHS user but not necessarily uniquely. The O/R address uniquely identifies an MHS user. + +Either or both components of an O/R name may be used on submission of a message. If only the directory name is present, the MHS will access a directory to attempt to determine the O/R address, which it will then use to route and deliver the message. If the directory name is absent, it will use the O/R address, as given. When both are given on submission, the MHS will use the O/R address, but will carry the directory name and present both to the recipient. If the O/R address is incorrect, it will then attempt to use the directory name as above. + +## 5.3 *O/R addresses* + +An O/R address contains information that enables the MHS to uniquely identify a user to deliver a message or return a notification to him. (The prefix "O/R" recognizes the fact that the user can be acting as either the originator or recipient of the message or notification in question). + +Various forms of O/R addresses are currently defined, each serving its own purpose. These forms and their purpose are as follows: + +- *Mnemonic O/R address*: Provides a user-friendly means of identifying users in the absence of a directory. It is also used for identifying a distribution list. +- *Terminal O/R address*: Provides a means of identifying users with terminals belonging to various networks. +- *Numeric O/R address*: Provides a means of identifying users with numeric keypads. +- *Postal O/R address*: Provides a means of identifying originators and recipients of messages and notifications, for physical delivery. + +An O/R address is made up of a collection of information called attributes. These attributes as used in each of the O/R address forms above are detailed in Recommendation F.401. + +Management domains shall allow their users to originate messages using any of the above forms. The form in which names are input by or presented to the subscriber is a national matter (as for example the use of distribution lists or of friendly ways of identifying user agents). + +Each Administration is responsible for the unique identification of each user agent in its management domain. + +# **6 Operation of the service** + +## **6.1 General** + +6.1.1 The IPM service provides that messages can be sent, transferred, delivered and received, using fully automatic procedures. + +*Note* – Manual receipt and sending of messages can be provided in the case of interworking with postal systems. + +6.1.2 Messages are prepared in, sent from, and delivered to a memory. These memories are part of the user agent/MS functionality and are under control of the subscriber. + +6.1.3 The transfer of messages between management domains will be in accordance to the Message Transfer service as described in Recommendation F.410. + +6.1.4 Each Administration providing the IPM service should validate the subscribers identities, at the time of access. + +*Note* – Further study is needed in the case of auto-receipt. + +6.1.5 It is a national matter whether to allow private messaging systems to connect to the public IPM service, in order to allow users of these systems to exchange messages. If these interconnections are provided, they should take place between Administration management domains in accordance with CCITT Recommendations. + +6.1.6 When implicit conversion is provided by the Administration via the message transfer service, the message will be converted if necessary, unless prohibited by the originator. The conversion will be in accordance to the rules specified in Recommendation X.408. See also § 4 of this Recommendation. + +6.1.7 Deferred delivery shall be provided by the management domain of the originator, which is responsible for the storage of the message until the date and time specified for intended delivery. Therefore the element of service, deferred delivery, should not be used across international links. + +## **6.2 Message handling phases** + +### **6.2.1 General** + +The IPM service has different message handling phases visible to the user. + +### **6.2.2 Preparation phase** + +In this phase, messages are prepared by making use of the user agent functionality (e.g. editing and filing). The way in which these functions are performed is outside the scope of this Recommendation. + +### **6.2.3 Sending phase** + +In this phase, the originator may request the user agent or message store to send a prepared message to one or more recipients and to request certain optional user facilities. + +### **6.2.4 Receipt phase** + +In this phase, the subscriber can receive delivered messages and notifications from his user agent or message store. The receipt phase can be initiated by the service (auto-receipt) or by the subscriber for message reception. The operation of the user agent receiving messages is specified in Recommendation X.420. + +Subscribers using terminals without user agent functionality may register for a contractual period of time during which they will receive delivered messages automatically from their user agent to a terminal, if the Administration provides for this alternative. Normally the user agent is called to receive incoming messages. + +In the case of auto-receipt, the MHS will initiate a call to the subscriber's terminal. In the other case, the subscriber shall initiate a call to the MHS at a time convenient to the subscriber. + +The body parts of the message will be received by the subscriber in the form in which the originator has sent it, unless conversion has been performed. + +For messages delivered to a teletex access unit, Recommendation T.330 defines the optional means by which the subscriber may receive or retrieve delivered messages. + +The indication of the optional user facilities requested by the originator are presented by the user agent to the recipient in a form convenient to him. + +*Notifications:* four notifications can be received: + +- non-delivery notification; +- delivery notification; +- receipt notification; +- non-receipt notification. + +Non-delivery notification and delivery notification (if requested) are automatically generated by the MTS, while receipt and non-receipt notification depend on the action of the recipient UA/recipient. + +# 7 Quality of Service + +## 7.1 *Message status* + +The unique identification of each IP-message enables the system to provide information about, e.g., the status of an IP-message. + +In the event of system failure, all accepted and non-delivered messages should be traceable. If messages cannot be delivered, the originator must be informed by a non-delivery notification. + +## 7.2 *Support by Administrations* + +Administrations should provide assistance to their subscribers, with regard to non-delivery notifications not being received in due time, as far as public system components are concerned. Additional provision on support of status and tracing of messages may be provided under national responsibility. + +When the user agent is provided by an Administration, additional functionality should be provided in order to minimize cases of not reading messages within a certain period of time (the definition of this period is for further study). This functionality could be, for example, alert messages sent to an automatic reception terminal. + +## 7.3 *Model of delivery and notification times* + +See Figure 1/F.420. + +## 7.4 *Message delivery time targets* + +The management domain of the recipient UA should force non-delivery notification if the message has not been delivered before $x$ hours after submission (or after date and time indicated for deferred delivery), the value of $x$ being dependent on the grade of delivery requested by the originator. (See Recommendation F.410, § 4.4.) + +![Sequence diagram of the Notification time model showing message flow between UA/MS, MTA, and MS/UA entities. It defines three time intervals: T1 (Delivery time), T2 (Delivery notification time), and T3 (Receipt notification time).](d4af765160d04ecef538e5066006dc77_img.jpg) + +The diagram illustrates the notification time model for a message transfer. The entities involved are a User Agent (UA) or Message Store (MS) on the left, two Message Transfer Agents (MTA) in the center, and a Message Store (MS) or User Agent (UA) on the right. The sequence of events is as follows: + + +- Creation of message**: Occurs at the left UA/MS. +- Submission of message**: The message is submitted from the left UA/MS to the first MTA. +- Transfer of message**: The message is transferred between the two MTAs. +- Delivery of message**: The message is delivered from the second MTA to the right MS/UA. +- Notification generation**: Occurs at the right MS/UA upon delivery. +- Notification delivery**: The notification is sent from the right MS/UA back to the left UA/MS. +- Reading of message**: Occurs at the right MS/UA after delivery. +- Receipt notification**: A receipt notification is generated at the right MS/UA upon reading and sent back to the left UA/MS. + + Three time intervals are defined: + + +- T1**: Delivery time, measured from the submission of the message to the first MTA until the delivery of the message to the right MS/UA. +- T2**: Delivery notification time, measured from the submission of the message to the first MTA until the notification delivery back to the left UA/MS. +- T3**: Receipt notification time, measured from the reading of the message at the right MS/UA until the receipt notification is delivered back to the left UA/MS. + + A label 'T0102770-92' is present near the bottom right of the diagram. + +Sequence diagram of the Notification time model showing message flow between UA/MS, MTA, and MS/UA entities. It defines three time intervals: T1 (Delivery time), T2 (Delivery notification time), and T3 (Receipt notification time). + +T1 Delivery time + T2 Delivery notification time } For more details, see Recommendation F. 410. + T3 Receipt notification time + +*Note 1* – Starting time of T3 corresponds to the time the message is displayed to the user and and Receipt Notification is actioned by the user. + +*Note 2* – Ending time of T3 is the time that the Receipt Notification is made available to the user through the UA or MS. + +*Note 3* – Similar considerations apply to Non-receipt Notifications. + +FIGURE 1/F.420 +**Notification time model** + +## 7.5 *Delivery notification time targets* + +Non-delivery notifications or requested delivery notifications should be returned on a per-recipient basis, in order not to delay notifications for those messages in a multi-addressed message which have already been delivered, to enable the originating management domain either to return per-recipient notifications or to batch notifications to its subscribers. (See Recommendation F.410, § 4.5.) + +## 7.6 *Receipt notifications and non-receipt notifications* + +Non-receipt notifications are generated automatically by the receiving UA. + +Time targets for receipt notifications in the first place depend on local arrangements. When receipt notifications or non-receipt notifications are initiated by the receiving UA/user, they have the same time targets as the messages that cause them to occur (see Table 1/F.420). + +TABLE 1/F.420 + +### **Receipt and non-receipt notification time targets** + +| Grade of delivery
(of the referred message) | 95% delivered within | +|------------------------------------------------|----------------------| +| Urgent | 0.25 hours | +| Normal | 1.0 hour | +| Non-urgent | 4.0 hours | + +*Note* – It is expected that PRMDs will abide by these notification time targets. + +## **7.7 Error protection** + +Error protection on transmission is provided by the MHS and underlying protocols used in the provision of the IPM service. + +## **7.8 Availability of service** + +In principle, the IPM service should be available continuously. The user agent should be available for submission or delivery continuously (unless hold for delivery is invoked). In cases where the UA is not available for delivery continuously, a message store should be used. + +## **7.9 Minimum storage capacity** + +The storage capacity of a user agent and message store shall be sufficient to provide a high grade of service. + +*Note* – This is for further study. + +# **8 Tariff and accounting principles** + +See D-Series Recommendations, specifically; + +- D.35 – General charging principles in the international public message handling services and associated applications (1992) +- D.36 – General accounting principles applicable to message handling services (1991). + +# **9 Network requirements** + +The IPM service is network independent, that is, the basic service and the essential optional user facilities are provided independently of the type of network used for service access. Additional optional user facilities chosen by an Administration to offer may vary. + +# 10 User information and support + +A directory shall be provided by each Administration for its domain. The directory can be hard copy or preferably electronic form. + +The directory shall at least contain the following: + +- a) how to use the directory and the service; +- b) list of O/R addresses of subscribers belonging to the Administration's domain; +- c) list of standardized abbreviations for O/R address attributes; +- d) list of country and Administration management domain names reachable by the public IPM service. + +# 11 Use of the IPM service within CCITT-defined telematic services + +See relevant F-Series Recommendations. + +# ANNEX A + +(to Recommendation F.420) + +## Alphabetical list of abbreviations used in this Recommendation + +| | | +|------|-----------------------------------| +| A | Additional optional user facility | +| ADMD | Administration management domain | +| DL | Distribution list | +| E | Essential optional user facility | +| EIT | Encoded information type | +| G3 | Group 3 (facsimile) | +| G4 | Group 4 (facsimile) | +| IA5 | International Alphabet No. 5 | +| IP | Interpersonal | +| IPM | Interpersonal messaging | +| MD | Management domain | +| MH | Message Handling | +| MHS | Message handling system | +| MS | Message store | +| MT | Message Transfer | +| MTA | Message transfer agent | +| MTS | Message transfer system | +| N/A | Not applicable | +| O/R | Originator/recipient | + +| | | +|-------|---------------------------| +| PD | Physical delivery | +| PDN | Public data network | +| PDS | Physical delivery system | +| PRMD | Private management domain | +| TTXAU | Teletex access unit | +| UA | User agent | + +*Note 1* – For a glossary of terms, see Annex A to Recommendation F.400. + +*Note 2* – For references, see Recommendations F.400 and F.401. + +# ANNEX B + +(to Recommendation F.420) + +## Subscriber access and terminal requirements + +## B.1 *General* + +Various types of terminals may be used for accessing the service. These terminals are functionally divided into two categories: those without user agent functionality, and those with user agent functionality. The telematic terminals assume a special user agent. Telex terminals belong to that first category. + +## B.2 *Terminals without UA functionality* + +Terminals in this category require additional functions to be provided by MHS to enable their participation in the IPM service. + +### B.2.1 *Telex terminals* + +Telex terminals shall conform to the relevant technical Recommendations, and be based on the relevant service Recommendations. + +### B.2.2 *Teletex terminals* + +Teletex terminals shall conform to Recommendations T.60 and T.61. Documents which are exchanged between teletex terminals and the IPM service shall be in conformance to Recommendation F.200. + +The access procedures for submission and delivery of documents shall conform to Recommendation T.330. + +*Note* – The use of the interactive session protocol for submission and delivery is for further study. The ability to provide IPM service for documents using teletex standardized options is for further study. + +### B.2.3 *Facsimile terminals* + +Group 3 and Group 4 facsimile terminals should have access to the IPM service. + +*Note* – Access procedures are for further study. + +### B.2.4 *Videotex terminals* + +These terminals shall conform to Recommendation F.300. + +*Note* – Access procedures are for further study. Eventual subset of Recommendation F.300 needs to be considered. + +### B.2.5 *IA5 terminals* + +The IA5 terminals are terminals able to send and receive messages encoded by characters chosen from the International Alphabet No. 5 (Recommendation T.50). The access procedures shall be based on one of the applicable procedures specified in Recommendations X.20 to X.32. These procedures describe the possibility for access to public data networks (PDNs) for data transmission. + +*Note – Additional procedures are for further study.* + +## B.3 *Terminals with UA functionality* + +These terminals shall, as a minimum, have the capabilities to: + +- 1) provide the capabilities to subscribers of the basic features defined in § 2; +- 2) make use of the IPM protocol specified in Recommendation X.420; +- 3) use the submission and delivery protocol specified in Recommendation X.419; +- 4) use the remote operation procedures specified in Recommendation X.419. + +These terminals shall be able to handle at least one EIT as defined in Recommendation X.408 (e.g. IA5, teletex, etc.). + +# APPENDIX I + +(to Recommendation F.420) + +## **Errata to Recommendations F.421 and F.422, in Fascicle II.6 CCITT Blue Book 1989** + +### I.1 *Errata to Recommendation F.421* + +(Page 128). In the first line of the first sentence *change* “message handling service” to “message handling services”. + +(Page 131, § 4.2.2.5). In the first sentence *change* “or and end” to “or an end” + +(Page 131, § 4.2.2.5). In the first sentence *change* “transmission” to “transaction”. + +(Page 135, Annex A). The abbreviation for “Initials” should be “INI”. + +(Page 135, Annex A). The name for “EOT” should be “End of Transaction”. + +(Page 137, Annex B). In Table B-1 entry B.80 *change* “Sensibility” to “Sensitivity” in the second column. + +(Page 137, Annex B). In Table B-1 entry B.80 *delete* text in third column and replace with “National Matter”. + +(Page 137, Annex B). In Table B-1 entry B.89 *add* “indication” to end of element of service name in second column. + +### I.2 *Errata to Recommendation F.422* + +(Page 142, § 2.2.1). In the second sentence *change* “may” to “should”. + +(Page 144, Table 1). In entry B.54, Column 4 *add* “X”. + +(Page 144, Table 1). 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the letters ITU.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: A globe with a lightning bolt and the letters ITU. + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**F.471** + +(08/97) + +SERIES F: NON-TELEPHONE TELECOMMUNICATION +SERVICES + +Message handling services + +--- + +**Operational requirements for the +interconnection of voice-mail store-and-forward +units** + +ITU-T Recommendation F.471 + +(Previously CCITT Recommendation) + +--- + +# ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1–F.109 | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | F.110–F.159 | +| Mobile services and multdestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | F.160–F.399 | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | F.550–F.599 | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| AUDIOVISUAL SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to ITU-T List of Recommendations.* + +## **ITU-T RECOMMENDATION F.471** + +# **OPERATIONAL REQUIREMENTS FOR THE INTERCONNECTION OF VOICE-MAIL STORE-AND-FORWARD UNITS** + +## **Summary** + +This Recommendation describes the general principles and operational aspects of the voice-mail store-and-forward service defined in Recommendation F.472 when operated and interconnected between service providers. It also addresses the elements of service offered by Voice-mail Store-and-Forward Units (Voice SFUs) to its direct user, a voice-mail system and between Voice SFUs. + +This service is designed to be implemented in conjunction with Recommendation F.472 which describes the voice-mail store-and-forward service. + +### **Source** + +ITU-T Recommendation F.471 was prepared by ITU-T Study Group 7 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 9th of August 1997. + +## FOREWORD + +ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +## INTELLECTUAL PROPERTY RIGHTS + +The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, the ITU had/had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. + +© ITU 1997 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +## CONTENTS + +| | Page | +|------------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References ..... | 1 | +| 3 Abbreviations ..... | 1 | +| 4 Definitions ..... | 2 | +| 5 Introduction ..... | 2 | +| 5.1 Interaction between the VMS and its direct user ..... | 2 | +| 5.2 Interaction between a Voice SFU and its direct user (i.e. VMS) ..... | 3 | +| 5.3 Interaction between Voice SFUs ..... | 3 | +| 5.4 Interaction between a Voice SFU and direct users of other services ..... | 3 | +| 6 Overview ..... | 3 | +| 6.1 Interconnection ..... | 4 | +| 6.2 Technical requirements ..... | 4 | +| 6.3 Accounting and settlement ..... | 4 | +| 7 Interconnection requirements ..... | 4 | +| 7.1 General ..... | 4 | +| 7.2 Information exchange ..... | 4 | +| 7.3 Voice encoding ..... | 5 | +| 7.4 Transit arrangements ..... | 5 | +| 8 Service interworking principles ..... | 6 | +| 8.1 Message addressing ..... | 6 | +| 8.2 Message identification ..... | 7 | +| 8.3 Classes of service ..... | 7 | +| 8.4 Message deferral ..... | 7 | +| 8.5 Envelope ..... | 8 | +| 8.6 Successful/unsuccessful message transfer notifications ..... | 8 | +| 8.7 Successful/unsuccessful message delivery notifications ..... | 8 | +| 8.8 Voice coding encoding conversion ..... | 9 | +| 9 Quality of service ..... | 9 | +| 9.1 Objectives ..... | 9 | +| 9.2 Storage capacity ..... | 9 | +| 9.3 Observations on the quality of service ..... | 9 | +| 9.4 Duration of service ..... | 9 | + + + +# OPERATIONAL REQUIREMENTS FOR THE INTERCONNECTION OF VOICE-MAIL STORE-AND-FORWARD UNITS + +(Geneva, 1997) + +## 1 Scope + +This Recommendation describes the general principles and operational aspects of the voice-mail store-and-forward service defined in Recommendation F.472 when operated and interconnected between service providers. It also addresses the elements of service offered by Voice-mail Store-and-Forward Units (Voice SFUs) to its direct user, a voice-mail system, and between Voice SFUs. + +This service is designed to be implemented in conjunction with Recommendation F.472 which describes the voice-mail store-and-forward service. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. + +- ITU-T Recommendation F.472 (1997), *Service and operational requirements of the voice-mail store-and-forward service*. +- ITU-T Recommendation F.400/X.400 (1996), *Message handling: System and service overview*. +- CCITT Recommendation F.440 (1992), *The voice messaging service*. +- CCITT Recommendation X.440 (1992), *Message handling systems: Voice messaging system*. +- CCITT Recommendation G.721 (1990) (See ITU-T Recommendation G.726.) +- CCITT Recommendation G.726 (1992) (Has replaced former CCITT Recs. G.721 and G.723), *40, 32, 24, 16 kbit/s Adaptive Differential Pulse Code Modulation (ADPCM)*. +- ITU-T Recommendation G.728 – Annex G (1994), *16 kbit/s fixed point specification*. +- IETF RFC ??? – April 1997 – *Voice Profile for Internet Mail (VPIM) – Version 2*. + +NOTE – This new reference is incomplete as the document is not yet published. It is expected to be published in April 1997 as an Internet Proposed Standard. At such time as the additional reference information is known (RFC number and publication date) the TSB editor will be advised by the document editor. + +## 3 Abbreviations + +This Recommendation uses the following abbreviations: + +| | | +|---------|---------------------------------------------| +| A | Additional EOS (defined in 3.1/F.472) | +| ADPCM | Adaptive Differential Pulse Code Modulation | +| B | Basic EOS (defined in 3.1/F.472) | +| DEST | Destination Voice SFU | +| E | Essential EOS (defined in 3.1/F.472) | +| EOS | Element of Service | +| IETF | Internet Engineering Task Force | +| Level 1 | Level 1 notification | + +| | | +|---------|---------------------------------| +| Level 2 | Level 2 notification | +| ORIG | Origination | +| REC | Reception | +| SFU | Store-and-Forward Unit | +| TRANS | Transit voice SFU | +| VM S&F | Voice-Mail Store-and-Forward | +| VMS | Voice-Mail System | +| VPIM | Voice Profile for Internet Mail | + +## 4 Definitions + +This Recommendation incorporates by reference the terms listed below from Recommendation F.472. + +Message submission + +Recipient address + +Transfer system + +Transit facility + +Voice-mail message + +Voice-mail message delivery + +Voice-mail message transfer + +Voice-mail notifications + +Voice-mail system + +Voice-mail system service interface + +Voice SFU + +Voice signature + +## 5 Introduction + +A growing number of service providers are offering voice-mail store-and-forward services to their customers. For the efficient and economical extension of these services across international boundaries, there is a need to specify the service elements used to provide these services. This Recommendation, along with Recommendation F.472, is designed to meet these needs. Recommendation F.472 defines a VM S&F service to enable the international interconnection of disparate VMS equipment, while this Recommendation defines the operational aspects of international interconnection of Voice SFUs to realize the VM S&F service. + +The VM S&F is comprised of one or more domains where a domain is a logical entity that incorporates at least a single Voice SFU and one or more VMSs, though not indicated in this figure. + +Figure 1 identifies the scope of both this Recommendation and Recommendation F.472. Furthermore, it identifies the following four (4) points of interaction. + +### 5.1 Interaction between the VMS and its direct user + +The interaction point between the VMS and its direct user is identified as "1" in Figure 1. The direct user consumes the services of the VMS identified in Recommendation F.472. The concrete realization of support for these services by a VMS is considered to be a local matter. + +![Figure 1/F.471 – Voice-mail store-and-forward service overview. The diagram shows a central dashed box labeled F.472 containing three Voice SFU blocks. Above the top-left Voice SFU is a VMS block, which is connected to two User ovals (labeled 1). Above the top-middle Voice SFU is another VMS block, connected to two User ovals (labeled 1). Above the top-right Voice SFU is a third VMS block, connected to two User ovals (labeled 1). The three Voice SFU blocks are interconnected by lines labeled 3. A dashed box labeled F.471 encloses the three Voice SFU blocks. Below the bottom Voice SFU is a VMS block, connected to a single User oval (labeled 1). To the right of the F.472 box is an oval labeled 'Other services', connected to the top-right Voice SFU by a line labeled 4. The text T0727060-96/d01 is located to the right of the F.472 box.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +Figure 1/F.471 – Voice-mail store-and-forward service overview. The diagram shows a central dashed box labeled F.472 containing three Voice SFU blocks. Above the top-left Voice SFU is a VMS block, which is connected to two User ovals (labeled 1). Above the top-middle Voice SFU is another VMS block, connected to two User ovals (labeled 1). Above the top-right Voice SFU is a third VMS block, connected to two User ovals (labeled 1). The three Voice SFU blocks are interconnected by lines labeled 3. A dashed box labeled F.471 encloses the three Voice SFU blocks. Below the bottom Voice SFU is a VMS block, connected to a single User oval (labeled 1). To the right of the F.472 box is an oval labeled 'Other services', connected to the top-right Voice SFU by a line labeled 4. The text T0727060-96/d01 is located to the right of the F.472 box. + +Figure 1/F.471 – Voice-mail store-and-forward service overview + +### 5.2 Interaction between a Voice SFU and its direct user (i.e. VMS) + +The interaction point between a Voice SFU and its direct user is identified as "2" in Figure 1. The direct user consumes the services of a Voice SFU identified in Recommendation F.472. The concrete realization of support for these services by a Voice SFU is considered to be a local matter. + +### 5.3 Interaction between Voice SFUs + +The interaction point between Voice SFUs is identified as "3" in Figure 1. It is understood that the intercommunication of Voice SFUs employs a transfer mechanism, such as the message transfer service specified in Recommendation F.410. A Voice SFU consumes transfer services as well as the services provided by its correspondent Voice SFU as identified in this Recommendation. The concrete realization of support for these services by a Voice SFU is considered to be a local matter. + +### 5.4 Interaction between a Voice SFU and direct users of other services + +The interaction point between a Voice SFU and an indirect user who is a direct user of another service is identified as "4" in Figure 1. The indirect user through its association with other services may consume all or some of the services identified in this Recommendation for direct users. The concrete realization of support for these services may be the subject of future standardization. + +## 6 Overview + +This Recommendation defines the set of operational network services offered by voice-mail store-and-forward service providers for the interconnection of Voice SFUs, as well as voice-mail store-and-forward services offered by service providers to a direct user (a VMS). Message transfer services employed for the interconnection of voice-mail systems and/or services are also identified herein. + +### 6.1 Interconnection + +The following two types of Voice SFU interconnection, as illustrated in Figures 1 and 2, have been identified: + +- Directly interconnected: Two or more VM S&F services and their associated Voice SFUs intercommunicating directly, i.e. without relaying through another VM S&F service. +- Indirect interconnection: Two or more VM S&F services and their associated Voice SFUs intercommunicating by relaying through another VM S&F service and its associated Voice SFU. + +![Diagram of Voice SFU interworking scenarios showing direct and indirect connections between Voice SFUs in Country A and Country B via a Transit Voice SFU.](e6df2733626a85205c1db682e6259c46_img.jpg) + +The diagram illustrates two interconnection scenarios for Voice SFUs. In the top part, a 'Voice SFU Country A' and a 'Voice SFU Country B' are connected directly by a horizontal line. Both boxes have a '1' next to their top-left corner. In the bottom part, the 'Voice SFU Country A' is connected to a 'Voice SFU Transit' box, which is then connected to the 'Voice SFU Country B'. The 'Voice SFU Transit' box also has a '1' next to its top-left corner. A label 'T0104050-94/d02' is located below the 'Voice SFU Transit' box. + +Diagram of Voice SFU interworking scenarios showing direct and indirect connections between Voice SFUs in Country A and Country B via a Transit Voice SFU. + +Figure 2/F.471 – Voice SFU interworking scenarios + +Although not expressly shown, Figure 2 also implies the services offered by the Voice SFU to its direct user as depicted in Figure 1. + +Interconnection between Voice SFUs and message handling systems may be provided by the transfer system. Details are for further study. + +### 6.2 Technical requirements + +Technical requirements of the service are covered in other publications, e.g. in the relevant G- and X-Series Recommendations. The protocol used to concretely realize the interconnection of Voice SFUs with one another and with VMSs is a local matter. However, interconnection of Voice SFUs using the Message Handling System (MHS) is recommended and interconnection using the Voice Profile for Internet Mail (VPIM) is optional. + +### 6.3 Accounting and settlement + +Accounting and settlement aspects are covered in D-Series Recommendations. Voice SFUs shall record and store sufficient information for charging and settlement of accounts, when applicable. + +## 7 Interconnection requirements + +### 7.1 General + +In the interconnection of Voice SFUs, the responsibility to deliver single and multi-address messages is transferred from the originating Voice SFU to one or more destination Voice SFUs. + +### 7.2 Information exchange + +The basic unit of communication between VM S&F services is a message. Two types of messages are defined: a voice-mail message and a voice-mail notification. + +#### 7.2.1 Voice-mail message + +Voice-mail message is described in and imported from Recommendation F.472 (see 4.13 and throughout). + +#### 7.2.2 Voice-mail notifications – Level 1 and Level 2 notifications + +Voice-mail notifications requirements are established in 7.2.4/F.472 and described in terms of elements of service as specified in Table 1 and Table 2. + +Level 1 notifications support the services identified in Table 1, and convey the semantics of successful or unsuccessful transfer of responsibility for the message to the destination Voice SFU in the recipient's VM S&F service or a redirecting Voice SFU. + +Level 1 notifications shall be generated for all message transfers. + +NOTE 1 – As defined in 1.1/F.440, if the message is redirected to another recipient by a delivery Voice SFU, interim Level 1 notifications may be received by the originating Voice SFU and its direct user. + +Level 2 notifications shall be generated only if requested by the originator as indicated by the value of the original message "class of service indication" EOS, i.e. it conveys the value of "certified" receipt requested. + +Level 2 notifications support the services identified in Table 2, and convey the semantics of successful or unsuccessful transfer of responsibility for the message from the destination Voice SFU to the recipient's voice-mail system. + +NOTE 2 – Depending on local implementation of this service, a Level 2 notification may indicate that the responsibility for the message was accepted by the voice-mail system or the message was delivered to the recipient's mailbox at the destination voice-mail system. + +**Table 1/F.471 – Level 1 notification service elements (Level 1)** + +| Element of service | Orig. | Rec. | EOS #
F.472 and F.400
Annex A/B
reference | +|------------------------------------------------------------------------------------------------------------------------------|-------|------|----------------------------------------------------| +| Message identification | B | B | B.41/F.400 | +| Originator indication (to provide the "notification originator identification") | B | B | B.55/F.400 | +| Message recipient (to provide the "original message recipient indication") | B | B | A.5/F.472 | +| Original encoded information types indication | B | B | B.54/F.400 | +| Delivery report (to provide):
– the date and time of delivery or failure;
– failure reason and diagnostic information. | B | B | A.20/F.400 | +| Class of message delivery | B | B | A.2/F.472 | +| B Basic feature as defined in F.472. | | | | + +### 7.3 Voice encoding + +To ensure compatibility between all Voice SFUs, the audio voice message is to be digitally encoded according to Recommendation G.726 which defines 32 kbit/s ADPCM. However, other encodings may be used (e.g. Recommendation G.728 LD-CELP) but conversion facilities to and from Recommendation G.726 must be provided as noted in 8.8. + +### 7.4 Transit arrangements + +The use of transit service elements for message transfer is subject to agreement of the service providers involved. Transit EOS support classification is identified in Table 3 as a column titled "TRANS". + +A voice message may pass through a transit facility consisting of a Voice SFU or some other transfer system. Voice SFUs offering transit, redirection, distribution list expansion or relay services shall support Level 1 notifications. + +**Table 2/F.471 – Level 2 notification service elements (Level 2)** + +| Element of service | Orig. | Rec. | EOS #
F.472 and F.400
Annex A/B
reference | +|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|------|----------------------------------------------------| +| Message identification | B | B | B.41 | +| Originator indication (to provide "notification originator identification") | B | B | B.55 | +| Message recipient (to provide the "original intended message recipient indication") | B | B | A.5/F.472 | +| Original encoded information types indication | B | A | A.33 | +| Class of message delivery | B | A | A.2/F.472 | +| Notification details (to provide):
– responsibility acceptance or non-acceptance indication;
– date and time;
– failure reason and diagnostic information;
– message duration a) ;
– delivery duration a) ;
– receiving terminal identification a) ;
– time last attempted a) ;
– number of attempts a) ;
– delivered message duration a) . | E | B | A.7/F.472 | +| a) As defined in 1.1/F.440. | | | | + +Where a message contains a multiple recipient address, it shall be possible for the transit facility to accept responsibility for some recipient addresses and to onward transfer to one or more Voice SFUs or transfer systems the responsibility for other recipient addresses. + +The transfer of messages between VM S&F service providers is subject to bilateral agreements. + +## 8 Service interworking principles + +The classification of the interworking requirements is shown in Table 3. + +### 8.1 Message addressing + +#### 8.1.1 Recipient addressing + +The delivery address of the message is the network address specifying the intended recipient of the message. + +##### 8.1.1.1 Single address message + +In the interconnection of Voice SFUs a single address shall be supported. + +##### 8.1.1.2 Multiple address message + +In the interconnection of Voice SFUs multiple addresses should be supported. + +##### 8.1.1.3 Distribution list identifier + +Expansion of distribution lists should be performed at the originating Voice SFU. Expansion of distribution lists at other Voice SFUs may be supported as part of the delivery service. + +#### 8.1.2 Originator addressing + +The address of the originator of a message is the originator's network address or the originator's VMS identification. + +**Table 3/F.471 – Interworking requirements of Elements of Service (EOS)** + +| Service element requirement | ORIG | TRANS | DEST | Subclause ref. | +|---------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|------|----------------| +| Single address message | E | E* | E | 8.1.1.1 | +| Multiple address message | A | E* | E | 8.1.1.2 | +| Distribution list identifier | A | N/A | N/A | 8.1.1.3 | +| Message identification | E | E | E | 8.2 | +| Class of service – delivery schedule | E | E* | E | 8.3.1 | +| Class of service – precedence service level | C | E* | E | 8.3.2 | +| Deferred delivery | C | N/A | N/A | 8.4 | +| Envelope | C | N/A | N/A | 8.5 | +| Successful message transfer notification (positive Level 1) | A | E | E | 8.6 | +| Unsuccessful message transfer notification (negative Level 1) | E | E | E | 8.6 | +| Successful message delivery notification (positive Level 2) | A | A | A | 8.7 | +| Unsuccessful message delivery notification (negative Level 2) | A | A | A | 8.7 | +| Voice coding encoding conversion | A | N/A | A | 8.8 | +| E* | Special kind of essential. In the case that the transit Voice SFU does not take responsibility for any message delivery, the service element shall be conveyed. | | | | +| N/A | Not applicable. | | | | +| ORIG | Originating Voice SFU. | | | | + +### 8.2 Message identification + +On successful submission of a message, the originating Voice SFU shall assign a globally unique identification to the message. The message identifier is used to identify the message in notifications between Voice SFUs. + +### 8.3 Classes of service + +In the interconnection of Voice SFUs two classes of service elements shall be supported: + +- 1) Delivery schedule. +- 2) Precedence service level. + +#### 8.3.1 Delivery schedule + +Two classes of **delivery schedule** are defined as urgent and routine according to the quality of service requirements set forth in clause 9. + +#### 8.3.2 Precedence service level + +Two classes of **precedence service level** are defined: private and certified. + +In the case of *private* messages, the destination SFU shall block attempts to forward the voice message to a destination other than that identified in the envelope (see 8.5). + +In the case of *certified* messages, the destination SFU shall provide a Level 2 notification to the originating Voice SFU. + +### 8.4 Message deferral + +The storage of messages to the customer specified time for message delivery should be carried out by the originating Voice SFU. + +### 8.5 Envelope + +The envelope shall be transferred from the originating Voice SFU to the destination Voice SFU. Table 4 specifies the VM S&F service envelope contents. + +**Table 4/F.471 – VM S&F service information provided to the user** + +| Information | Provided by | +|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------| +| Voice signature information | O/D (Note 1) | +| Voice subject information | O/D (Note 1) | +| Recipient addressing information includes:
– address (box number);
– organization;
– organizational unit(s);
– physical address lines;
– voice-mail network address. | O | +| Message information | | +| intended duration, minutes | O | +| class of service – delivery schedule | O | +| class of service – precedence service level | O | +| submission date and time | O | +| message reference | O | +| Originator addressing information includes:
– address (box number);
– organization;
– organizational unit(s);
– physical address lines;
– voice-mail network address. | O | +| Additional recipients | Note 2 | +| O Provided by originating Voice SFU.
D Provided by destination Voice SFU.
NOTE 1 – Provision of voice signature is by bilateral agreement.
NOTE 2 – Display of additional recipients is an item for further study. | | + +### 8.6 Successful/unsuccessful message transfer notifications + +A Level 1 includes information indicating the destination Voice SFU's successful and/or unsuccessful acceptance of responsibility for the message on a per recipient basis. + +A Level 1 which only contains information regarding unsuccessful transfer shall be generated by either the destination Voice SFU or the transit facility as soon as it is determined that responsibility for the message on a per recipient basis cannot be accepted or transferred. + +A Level 1 for successful transfer shall only be returned when requested. The request shall be processed on a per recipient basis. + +An unsuccessful message transfer is indicated by the generation of a negative Level 1 (there is no requirement for the generation of a negative Level 2 in this case). It shall be essential to return a Level 1 for unsuccessful transfer on a per recipient basis. + +### 8.7 Successful/unsuccessful message delivery notifications + +A positive Level 2 may indicate successful message delivery. It shall be returned to the originating Voice SFU on a per recipient basis. A Level 2 for successful message delivery shall only be returned when requested (i.e. precedence service level indicates "certified"). The request shall be processed on a per recipient basis. + +A negative Level 2 may indicate unsuccessful message delivery. It shall be returned to the originating Voice SFU on a per recipient basis. Level 2 notifications shall be generated for any unsuccessful delivery. + +In the context of this service, message delivery occurs when the VMS accepts responsibility for the message. + +### **8.8 Voice coding encoding conversion** + +If a Voice SFU supports voice coding encoding other than the default format defined in 7.3 (see Recommendation G.726), then the Voice SFU must support conversion between the default encoding and the other supported voice coding formats. Transfer of the message in other encoding is by bilateral agreement only. + +## **9 Quality of service** + +The quality of the subject voice encoded messages received from the originating VM S&F service should not be adversely affected by any intermediary or delivering Voice SFU, transfer service, or intermediary VM S&F service through which the message may pass. + +The quality of the voice message as received from the originating voice-mail system should not be adversely affected by any Voice SFU, transit facility, or any transmission service between Voice SFUs through which the voice-mail message may pass. + +### **9.1 Objectives** + +The following quality of service objectives are defined for messages passed across the international boundary for delivery by a destination Voice SFU. The overall service delivery objectives are specified in Table 2. In order that the destination Voice SFU is able to meet the objectives as stated in Table 2, the originating Voice SFU should transfer the message according to the objectives illustrated in Figure 3 and described in Table 5. + +The objectives for time, $T_A$ , $T_B$ , $T_1$ , $T_2$ and $T_3$ should be met for at least 95% of messages (during any one-hour period) 95% of the time. The number of attempts to deliver a message to the destination terminal and the interval between attempts are a local matter. + +The quality of service targets specified in Table 5 should not be affected by any transit of transmission service elements. + +If a message is interrupted during the delivery from the destination Voice SFU to the destination VMS, subsequent attempts to deliver the message should transfer all of the message. + +System design and dimensioning should be such that the quality of service objectives are met for at least 95% of messages received during any one-hour period 95% of the time. + +### **9.2 Storage capacity** + +Storage capacity should be sufficient to provide the quality of service target values stated in Table 5. + +### **9.3 Observations on the quality of service** + +Service providers shall make observations to evaluate the quality of the VM S&F service across national boundaries. + +### **9.4 Duration of service** + +The national and international VM S&F service shall operate continuously. + +![Sequence diagram of the voice-mail message transfer process. It shows interactions between an Origin Voice-mail system, an Origin Voice-mail SFU, a Destination Voice-mail SFU, and a Destination Voice-mail system, separated by an international boundary. The process includes message submission, transfer, Level 1 notification, message delivery (1st attempt), message delivery (last attempt of retry algorithm), Level 2 notification, and a customer report. Time intervals T1, T2, TA, TB, T3, and T4 are marked with vertical double-headed arrows.](fa859e4e468bfb2710a94527f2c504af_img.jpg) + +T0104770-95/d03 + +Sequence diagram of the voice-mail message transfer process. It shows interactions between an Origin Voice-mail system, an Origin Voice-mail SFU, a Destination Voice-mail SFU, and a Destination Voice-mail system, separated by an international boundary. The process includes message submission, transfer, Level 1 notification, message delivery (1st attempt), message delivery (last attempt of retry algorithm), Level 2 notification, and a customer report. Time intervals T1, T2, TA, TB, T3, and T4 are marked with vertical double-headed arrows. + +**Figure 3/F.471 – Voice-mail message transfer process** + +**Table 5/F.471 – Quality of service targets** + +| Time | Description | CMD | Target (hours) | +|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|----------------| +| T A | Time from the end of submission of the message, or the time specified for the deferred delivery, to the start of the first call attempt. | Urgent routine | ≤ 0.5
≤ 2.0 | +| T B | Time from the end of submission of the message, or the time specified for deferred delivery to the forced generation of a negative second level notification and termination of message delivery attempt (unless transmission has already commenced). | Urgent routine | ≤ 1.0
≤ 4.0 | +| T 1 | Time from the end of submission of the message, or the time specified for deferred delivery to the end of the transfer of the message from the originating Voice SFU to the destination Voice SFU. | Urgent routine | 0.3
-1.2 | +| T 2 | Time from the end of the transfer of the message from the originating Voice SFU to the destination Voice SFU, to the end of the transfer of the first level notification from the destination Voice SFU to the originating Voice SFU. | All | 0.25 | +| T 3 | Time from the end of message delivery or the forced generation of a negative second level notification, to the end of the transfer of a second level notification from the destination Voice SFU to the originating Voice SFU. | All | 0.3 | +| T 4 | Time from the end of transfer of a second level notification from the destination Voice SFU to the originating Voice SFU, to the generation of a customer report. | All | Local matter | + +CMD Class of Message Delivery + +# ITU-T RECOMMENDATIONS SERIES + +| | | +|-----------------|--------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of the ITU-T | +| Series B | Means of expression: definitions, symbols, classification | +| Series C | General telecommunication statistics | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of 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passing through it, with the letters 'ITU' superimposed on the left side.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: A stylized globe with a lightning bolt passing through it, with the letters 'ITU' superimposed on the left side. + +INTERNATIONAL TELECOMMUNICATION UNION + +# **ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## **F.63** + +(03/93) + +### **OPERATIONS AND QUALITY OF SERVICE TELEGRAPH SERVICES** + +### **ADDITIONAL FACILITIES IN THE INTERNATIONAL TELEX SERVICE** + +#### **ITU-T Recommendation F.63** + +(Previously “CCITT Recommendation”) + +# FOREWORD + +The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecommunication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +ITU-T Recommendation F.63 was revised by the ITU-T Study Group I (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). + +# NOTES + +1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector. + +In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms "CCITT, CCIR or IFRB" or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. + +2 In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# **ADDITIONAL FACILITIES IN THE INTERNATIONAL TELEX SERVICE** + +*(Melbourne, 1988; revised Helsinki, 1993)* + +The CCITT + +*considering* + +- (a) that the introduction of additional facilities in the international telex service is of interest and desirable; +- (b) the need to standardize facilities that may be provided by Administrations and that may be available on an international basis, + +*unanimously declares that* + +- 1) Administrations should give attention to the operational methods to be used in the establishment of calls in the international telex service as indicated in Recommendation F.60; +- 2) within exchange implementations, Administrations should consider the provision in the international telex service of the additional facilities listed in Table 1/F.63. + +TABLE 1/F.63 + +## **Additional facilities in the international telex service a)** + +| Facility | Definition reference b) | Relevant Recommendations | +|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------|---------------------------| +| Calling facilities | | | +| Automatic calling | F.60 (B.44) | S.16, S.19 | +| Subscriber call information | | | +| Line identification by the network | F.60 (B.48) | U.12 | +| Facilities offered in the case of unsuccessful attempts,
delayed or redirected calls | | | +| Call redirection | F.60 (B.62) | U.41 | +| Changed address interception | F.60 (B.63) | U.41 | +| Access to other networks and facilities | | | +| Interworking between networks c) | U.140 (11) | F.71, F.80, U.200 | +| Private network | U.140 (9) | – | +| Store and forward | F.60 (B.64) | F.72, U.80, U.81 | +| Delayed delivery | F.60 (B.67) | F.72, F.84 (F.421), U.204 | +| Status enquiry function | F.89 | F.89, U.220 | +| Categories of special or privileged users | | | +| Access barred | F.60 (B.31) | – | +| Public booths | F.60 (B.28) | – | +| Facilities for setting up multi-address calls | | | +| Broadcast call | F.60 (B.75) | U.44 | +| Conference call | F.60 (B.74) | – | +|

a) A non-restrictive interpretation should be made of Table 1, such that any facilities not included in the table are not thereby excluded from the international telex service, the decisions to be taken on this matter depending on a further study of each specific facility.

b) References are to Recommendations which contain the definition of the facility.

c) The intent in including this facility is to cover the interconnection of the international telex network with private networks (F.71). Interworking of the international telex service with other services and networks is described in the F.80- and U.200-Series Recommendations.

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SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multdestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| AUDIOVISUAL SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## Recommendation ITU-T F.734 + +# Definitions, requirements and use cases for telepresence systems + +## Summary + +Recommendation ITU-T F.734 provides definitions, use cases and functional requirements for telepresence systems. Telepresence is an interactive audio-visual communications experience between remote locations, where the users enjoy a strong sense of realism and presence between participants by optimizing a variety of attributes. A telepresence system is a set of functions, devices and network elements which are able to capture, deliver, manage and render multiple high quality interactive audio and video signals in a telepresence conference to deliver a telepresence experience. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.734 | 2014-10-14 | 16 | 11.1002/1000/12216 | + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2015 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +###### Page + +| | | | +|-----|-------------------------------------------------------|----| +| 1 | Scope..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 2 | +| 3.1 | Terms defined elsewhere ..... | 2 | +| 3.2 | Terms defined in this Recommendation..... | 2 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | Conventions ..... | 3 | +| 6 | Scenarios and use cases ..... | 3 | +| 6.1 | Use case 1: Symmetric point-to-point meeting ..... | 3 | +| 6.2 | Use case 2: Asymmetric point-to-point meeting ..... | 3 | +| 6.3 | Use case 3: Multipoint meeting ..... | 4 | +| 6.4 | Use case 4: Presentation ..... | 4 | +| 6.5 | Use case 5: Heterogeneous systems ..... | 5 | +| 6.6 | Use case 6: Multipoint education usage ..... | 6 | +| 6.7 | Use case 7: Multipoint multiview (virtual space)..... | 6 | +| 6.8 | Use case 8: Legacy interworking ..... | 7 | +| 6.9 | Use case 9: Telemedical use case ..... | 7 | +| 7 | User experience requirements..... | 8 | +| 8 | Control Functional requirements ..... | 10 | +| 8.1 | Call control functions ..... | 10 | +| 8.2 | Media control functions..... | 10 | +| 8.3 | Conference control functions ..... | 11 | +| 8.4 | Collaboration functions ..... | 12 | +| 8.5 | Other functions ..... | 12 | +| 9 | Interoperability requirements..... | 13 | +| 9.1 | Interoperation with traditional systems ..... | 13 | +| 9.2 | Interoperation between telepresence systems..... | 13 | +| 10 | Network requirements ..... | 13 | +| 11 | Security requirements ..... | 14 | +| | Bibliography..... | 15 | + + + +# Definitions, requirements and use cases for Telepresence Systems + +# 1 Scope + +This Recommendation provides definitions, use cases and functional requirements for telepresence systems. A telepresence system is a set of functions, devices and network elements which are able to capture, deliver, manage and render multiple high quality interactive audio and video signals in a telepresence conference. An appropriate number of devices (e.g., cameras, screens, loudspeakers, microphones, codecs, multipoint control units (MCUs), PCs) and environmental characteristics are used to establish telepresence. Specific requirements include those for: + +- User experience +- Control, including: + - Call control functions + - Media control functions + - Conference control functions + - Collaboration functions +- Inter-operability +- Network +- Security + +The requirements in this Recommendation relate to functions that a telepresence system is required to support. That is, a telepresence system should be able to provide the functions in its design or by utilizing existing mechanisms. Recommended requirements do not mandate the implementation or the deployment of a particular function. For example: Whilst a telepresence system should support mechanisms for assured QoS, it may be deployed in a network where QoS is not assured. + +Unless the requirement mentions a specific function or device, the requirements listed in this Recommendation apply to a telepresence system as a whole. The inclusion of a requirement does not necessarily mean that new protocols need to be developed to meet it. For example whilst there may be a requirement to support QoS for telepresence, ultimately existing QoS mechanisms may be utilized for this. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T H.243] Recommendation ITU-T H.243 (2005), *Procedures for establishing communication between three or more audiovisual terminals using digital channels up to 1920 kbit/s.* + +[ITU-T H.323] Recommendation ITU-T H.323 (2009), *Packet-based multimedia communications systems.* + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +None. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 actual size:** A rendered figure in a display is the same size as if the person is in the room. + +**3.2.2 capture:** Media acquired from a capture device such as a camera or microphone or constructed from other media (for example combining the signals from several microphones). + +**3.2.3 endpoint:** For the purposes of this Recommendation an endpoint is a device representing the logical point of final termination through receiving, decoding and rendering, and/or the point of origination through capturing, encoding, and sending of media streams, e.g., an H.323 terminal. + +**3.2.4 gaze awareness:** Awareness of gaze direction of persons by watching their eyes, head and body position. There is awareness of both direct gaze and averted gaze. Direct gaze is the perception of persons looking at each other directly and simultaneously. Averted gaze is the perception that other persons are looking at someone/something else in the environment. + +**3.2.5 gaze direction:** The vector positioned along the visual axis, pointing from the fovea of the looker through the centre of the pupil to the looked at spot. + +**3.2.6 eye contact:** Mutual direct-gaze between two persons communicating. + +**3.2.7 natural response:** Interaction between local and remote participants that is not impeded by the delay introduced by the telepresence system. + +**3.2.8 telepresence:** An interactive audio-visual communications experience between remote locations, where the users enjoy a strong sense of realism and presence between participants by optimizing a variety of attributes such as audio and video quality, eye contact, gaze awareness, body language, spatial audio, coordinated environments and natural image size. + +**3.2.9 telepresence-enabled audio endpoint:** An audio-only endpoint that supports telepresence endpoint functions/signalling and delivers a strong sense of presence and realism through the use of technologies such as wider bandwidth speech and spatial audio (e.g., stereo telephony). + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|-----------------------------| +| 3D | Three Dimensional | +| FECC | Far End Camera Control | +| HDTV | High Definition Television | +| IP | Internet Protocol | +| IPv4 | Internet Protocol Version 4 | +| IPv6 | Internet Protocol Version 6 | +| MCU | Multipoint Control Unit | +| NAT | Network Address Translation | +| PC | Personal Computer | +| QoE | Quality of Experience | + +| | | +|-----|-----------------------------| +| QoS | Quality of Service | +| SIP | Session Initiation Protocol | + +# 5 Conventions + +In this Recommendation, the following conventions apply. + +The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted, if conformance to this Recommendation is to be claimed. + +The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus this requirement need not be present to claim conformance. + +The keywords "can optionally" indicate an optional requirement which is permissible, without implying any sense of being recommended. This term is not intended to imply that the vendor's implementation must provide the option and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the specification. + +# 6 Scenarios and use cases + +The use cases in this clause illustrate various telepresence configurations for the purposes of identification of requirements. These configurations apply to scenarios where telepresence is in use and do not include legacy systems (i.e., non-telepresence systems) unless specifically indicated in the use case. They do not imply the need for mandatory support of any particular configurations. + +For simplicity, the use cases below assume that each camera and microphone produces a single capture, and that each display renders a single capture. In actual implementations, the relationship between captures and transducers can be more complex. For example, a pair of microphones may be mixed to monophonic sound (creating one capture from two transducers). Alternatively, the same microphone arrangement can produce three captures (left, right, and centre), creating three captures from the same two transducers. + +## 6.1 Use case 1: Symmetric point-to-point meeting + +In this case, the two sites have an identical number of screens, with cameras having fixed fields of view, and one camera for each screen. The number of screens or cameras is not relevant so long as both sites have the same number. The sound type is the same at each end. Figure 1 illustrates the use case. + +![Diagram of Use case 1: Symmetric point-to-point meeting. Two identical 'Two-screen telepresence endpoint' units are connected via an 'IP network' cloud. Each endpoint consists of two screens: the left screen shows two people icons, and the right screen shows a bar chart. Above each screen is a camera and microphone icon. The endpoints are connected to the IP network cloud by lines.](0bf9346902e9a3bdabf05ceacc1947f5_img.jpg) + +Diagram of Use case 1: Symmetric point-to-point meeting. Two identical 'Two-screen telepresence endpoint' units are connected via an 'IP network' cloud. Each endpoint consists of two screens: the left screen shows two people icons, and the right screen shows a bar chart. Above each screen is a camera and microphone icon. The endpoints are connected to the IP network cloud by lines. + +**Figure 1 – Use case 1: Symmetric point-to-point meeting** + +For further information see clause 3.1 of [b-IETF RFC 7205]. + +## 6.2 Use case 2: Asymmetric point-to-point meeting + +In this case, each site has a different number of screens and cameras. The number of screens or cameras is not relevant so long as both sites have a different number. Figure 2 illustrates the use case. + +For further information see clause 3.2 of [b-IETF RFC 7205]. + +![Diagram of Figure 2: Asymmetric point-to-point meeting. A central 'IP network' cloud is connected to two telepresence endpoints. On the left is a 'Two-screen telepresence endpoint' with two screens: one showing two people and the other showing a bar chart. On the right is a 'Three-screen telepresence endpoint' with three screens, each showing two people. Above each screen is a camera icon. The text 'F.734(14)_F02' is in the bottom right corner.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +Diagram of Figure 2: Asymmetric point-to-point meeting. A central 'IP network' cloud is connected to two telepresence endpoints. On the left is a 'Two-screen telepresence endpoint' with two screens: one showing two people and the other showing a bar chart. On the right is a 'Three-screen telepresence endpoint' with three screens, each showing two people. Above each screen is a camera icon. The text 'F.734(14)\_F02' is in the bottom right corner. + +**Figure 2 – Use case 2: Asymmetric point-to-point meeting** + +## 6.3 Use case 3: Multipoint meeting + +In this use case of a multipoint telepresence conference, there are more than two sites participating. Figure 3 illustrates the use case. + +For further information see clause 3.3 of [b-IETF RFC 7205]. + +![Diagram of Figure 3: Multipoint meeting. A central 'IP network' cloud is connected to three telepresence endpoints. Top-left is a 'Two-screen telepresence endpoint' (one screen with two people, one with a bar chart). Top-right is a 'Three-screen telepresence endpoint' (three screens, each with two people). Bottom is another 'Three-screen telepresence endpoint' (three screens, each with two people). Above each screen is a camera icon. The text 'F.734(14)_F03' is in the bottom right corner.](b8661c6c54f72ecc7ff6cb05e47b2891_img.jpg) + +Diagram of Figure 3: Multipoint meeting. A central 'IP network' cloud is connected to three telepresence endpoints. Top-left is a 'Two-screen telepresence endpoint' (one screen with two people, one with a bar chart). Top-right is a 'Three-screen telepresence endpoint' (three screens, each with two people). Bottom is another 'Three-screen telepresence endpoint' (three screens, each with two people). Above each screen is a camera icon. The text 'F.734(14)\_F03' is in the bottom right corner. + +**Figure 3 – Use case 3: Multipoint meeting** + +## 6.4 Use case 4: Presentation + +This use case builds on the previous use cases. In addition to the video and audio streams showing the participants, additional streams are used for presentations. For example, the additional stream may be for content sources such as: document cameras, electronic whiteboards, computer (e.g., a laptop computer) or instant messaging. Figure 4 illustrates the use case. + +The presentation viewgraphs can be distributed to remote endpoints either by adding new streams or by embedding (or switching) viewgraphs into an existing video stream. + +For further information see clause 3.4 of [b-IETF RFC 7205]. + +![Figure 4: Use case 4: Presentation. A diagram showing a central 'IP network' cloud connected to three telepresence endpoints. On the top left, a 'Two-screen telepresence endpoint' is connected to a 'Presentation capture' camera and a 'Presentation display' HDTV. On the top right, a 'Three-screen telepresence endpoint' is connected to a 'Personal computer' laptop. On the bottom, another 'Three-screen telepresence endpoint' is shown without external devices. Each endpoint box contains icons representing participants and, where applicable, a presentation slide.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +Figure 4: Use case 4: Presentation. A diagram showing a central 'IP network' cloud connected to three telepresence endpoints. On the top left, a 'Two-screen telepresence endpoint' is connected to a 'Presentation capture' camera and a 'Presentation display' HDTV. On the top right, a 'Three-screen telepresence endpoint' is connected to a 'Personal computer' laptop. On the bottom, another 'Three-screen telepresence endpoint' is shown without external devices. Each endpoint box contains icons representing participants and, where applicable, a presentation slide. + +**Figure 4 – Use case 4: Presentation** + +## 6.5 Use case 5: Heterogeneous systems + +This use case illustrates the common meeting scenario for people to join the conference from a variety of environments using different types of endpoint devices. A multi-screen immersive telepresence conference may include someone using a PC-based video conferencing system, a telepresence-enabled audio endpoint, or a handheld device. + +This use case assumes that all the endpoint devices are able to handle signalling related to telepresence systems. The underlying technology does not determine whether a device is "legacy" or not, the deciding factor is whether it supports telepresence related protocols (or protocol extensions). Legacy systems that do not support telepresence related protocols (or protocol extensions) are not in scope of this use case. Figure 5 illustrates the use case. + +For further information see clause 3.5 of [b-IETF RFC 7205]. + +![Figure 5: Use case 5: Heterogeneous systems. A diagram showing a central 'IP network' cloud connected to three telepresence endpoints and two other devices. The endpoints are: a 'Two-screen telepresence endpoint' (top left) connected to 'Presentation capture' and 'Presentation screen'; a 'Three-screen telepresence endpoint' (top right) connected to 'Presentation capture' and 'Presentation screen'; and a 'Three-screen telepresence endpoint' (bottom) shown without external devices. Additionally, a 'Personal computer' laptop and a 'Mobile phone' are connected directly to the central 'IP network' cloud.](5e92d9e8e9ce204e405bff2367f88176_img.jpg) + +Figure 5: Use case 5: Heterogeneous systems. A diagram showing a central 'IP network' cloud connected to three telepresence endpoints and two other devices. The endpoints are: a 'Two-screen telepresence endpoint' (top left) connected to 'Presentation capture' and 'Presentation screen'; a 'Three-screen telepresence endpoint' (top right) connected to 'Presentation capture' and 'Presentation screen'; and a 'Three-screen telepresence endpoint' (bottom) shown without external devices. Additionally, a 'Personal computer' laptop and a 'Mobile phone' are connected directly to the central 'IP network' cloud. + +**Figure 5 – Use case 5: Heterogeneous systems** + +## 6.6 Use case 6: Multipoint education usage + +This use case deviates from other use cases in that multiple video streams are not used to create an immersive conferencing experience with panoramic views at all sites. Instead the multiple streams are dynamically used to enable full participation of remote students in a university class. In some instances the same video stream is displayed on multiple screens in the room, in other instances an available stream is not displayed at all. Figure 6 illustrates the use case. + +For further information see clause 3.6 of [b-IETF RFC 7205]. + +![Diagram of Use case 6: Multipoint education usage. It shows an Auditorium on the left connected via an IP network cloud to two Three-screen telepresence endpoints on the right. The Auditorium contains a podium, a podium camera, full audience and zoom cameras, twin screens, and an audience. The telepresence endpoints each have three screens displaying remote participants.](27b06ec9f42b5d727a2630f61a5f1861_img.jpg) + +The diagram illustrates the 'Multipoint education usage' use case. On the left, an 'Auditorium' is shown. It contains a 'Podium' with a 'Podium camera' next to it. Above the podium are 'Full audience and zoom cameras'. To the right of the podium are 'Twin screens' displaying two remote participants. Below the screens is an 'Audience' represented by a grid of 12 person icons. A line connects the Auditorium to a central cloud labeled 'IP network'. From the IP network, two lines connect to two 'Three-screen telepresence endpoint' units on the right. Each endpoint consists of three screens, each displaying two remote participants. Above each set of three screens is a camera unit with three cameras. The label 'F.734(14)\_F06' is in the bottom right corner. + +Diagram of Use case 6: Multipoint education usage. It shows an Auditorium on the left connected via an IP network cloud to two Three-screen telepresence endpoints on the right. The Auditorium contains a podium, a podium camera, full audience and zoom cameras, twin screens, and an audience. The telepresence endpoints each have three screens displaying remote participants. + +Figure 6 – Use case 6: Multipoint education usage + +## 6.7 Use case 7: Multipoint multiview (virtual space) + +This use case describes a virtual space multipoint meeting with good eye contact and spatial layout of participants. Virtual space multipoint, as defined here, assumes endpoints with multiple cameras and displays. Usually there are the same number of cameras and displays at a given endpoint. A camera is positioned above each display. A key aspect of virtual space multipoint is the details of how the cameras are aimed. The cameras are each aimed on the same area of view of the participants at the site. Thus each camera takes a picture of the same set of people but from a different angle. Figure 7 illustrates the use case. + +For further information, see clause 3.7 of [b-IETF RFC 7205]. + +NOTE – This use case is not for 3D stereoscopic view. + +![Figure 7: Multipoint multiview (virtual space) diagram](af7916c89a458fdab6c3f443217388ae_img.jpg) + +This diagram illustrates a multipoint multiview telepresence session. At the center is a cloud labeled "IP network". Four "Multiview telepresence endpoint" units are connected to this central network. Each unit is represented by a rectangular box containing three smaller screens: a central screen showing a person icon, and two side screens showing camera icons. Each unit is also connected to a large blue speaker icon. The label "F.734(14)\_F07" is located in the bottom right corner of the diagram area. + +Figure 7: Multipoint multiview (virtual space) diagram + +**Figure 7 – Use case 7: Multipoint multiview (virtual space)** + +## 6.8 Use case 8: Legacy interworking + +This use case describes a case where a legacy videoconferencing endpoint (or other heterogeneous device such as voice only endpoint) is involved in the telepresence session. The legacy endpoint does not support telepresence related protocols, and interworking is required to communicate between the telepresence and legacy endpoints. Figure 8 illustrates the use case. + +This use case may also utilise other legacy equipment such as a legacy H.323 MCU in order to participate in a conference. + +![Figure 8: Legacy interworking diagram](410562339ce067fdc6fa41940c118658_img.jpg) + +This diagram shows a legacy interworking scenario. A central cloud labeled "IP network" is connected to two "Two-screen telepresence endpoint" units and one "Legacy ITU-T H.323 endpoint". Each "Two-screen telepresence endpoint" is shown as a box with two screens: one displaying two person icons and the other displaying a bar chart. The "Legacy ITU-T H.323 endpoint" is shown as a single screen unit. The label "F.734(14)\_F08" is located in the bottom right corner of the diagram area. + +Figure 8: Legacy interworking diagram + +**Figure 8 – Use case 8: Legacy interworking** + +## 6.9 Use case 9: Telemedical use case + +This use case describes a typical application of telepresence systems for medical usage. Multiple presentation streams are used dynamically to satisfy the need for presenting multiple videos and still images, etc. simultaneously. In this use case the endpoints are able to both receive and send multiple presentations. In some instances multiple presentation screens are used to enhance visibility. + +Figure 9 illustrates the use case. + +For further information see clause 3.8 of [b-IETF RFC 7205]. + +![Diagram of a telemedical use case showing three sites connected via an IP network. The Surgery room (top left) includes three-screen telepresence, an endoscopic monitor, a surgery camera, and medical data collection equipment. The Expert site (top right) includes one-screen telepresence, an HDTV presentation screen, pathology data, and a medical record. The Education site (bottom) includes three-screen telepresence and two HDTV presentation screens. All sites are connected to a central IP network cloud.](b9ecbc3baefab13719e000faa6e0c7eb_img.jpg) + +The diagram illustrates a telemedical use case involving three locations connected via a central IP network cloud. +1. **Surgery room** (top left): Features a 'Three-screen telepresence' setup with three monitors, each showing a participant. Below this are an 'Endoscopic monitor' displaying a medical image, a 'Surgery camera', and 'Medical data collection equipment'. +2. **Expert site** (top right): Features 'One-screen telepresence' with a single monitor showing a participant. Below it is an 'HDTV' labeled 'Presentation screen', 'Pathology data', and 'Medical record'. +3. **Education site** (bottom): Features another 'Three-screen telepresence' setup similar to the surgery room. Below it are two 'HDTV' units labeled 'Presentation screen'. +All three sites are connected to a central 'IP network' cloud. + +Diagram of a telemedical use case showing three sites connected via an IP network. The Surgery room (top left) includes three-screen telepresence, an endoscopic monitor, a surgery camera, and medical data collection equipment. The Expert site (top right) includes one-screen telepresence, an HDTV presentation screen, pathology data, and a medical record. The Education site (bottom) includes three-screen telepresence and two HDTV presentation screens. All sites are connected to a central IP network cloud. + +F.734(14)\_F09 + +**Figure 9 – Use case 9: Telemedical** + +# 7 User experience requirements + +This clause addresses user experience requirements of a telepresence system on an end-to-end system basis, primarily in terms of functional requirements rather than detailed performance requirements. + +**User01:** It is recommended that a telepresence system support actual size high definition imaging of videoconferencing participants at the remote end. The support of actual size is considered an advanced telepresence feature. + +**User02:** It is recommended that a telepresence system provide an experience where there is awareness of both direct gaze and averted gaze, with the video images of the remote participants being rendered within a tolerable angle in both horizontal and vertical axes from the gaze direction between the two communicating participants. + +NOTE 1 – The visual clues for determining the gaze direction may include the orientation of the looker's eyes with respect to their head and the orientation of the looker's head with respect to the environment. Some research suggests that tolerable angles are 3-5 degrees horizontal and up to 12 degrees upward and 8 degrees downward. + +**User03:** It is recommended that a telepresence system support a means of locating the speaker in a remote meeting room so that local participants can readily identify the position of different remote speakers. + +**User04:** It is required that a telepresence system enable synchronization of audio and video from the remote location. Synchronization includes "lip-sync" and the sequencing of multiple media streams. + +**User05:** It is recommended that a telepresence system provide a control function to allow a user to perform an operation with a minimum of input thus enabling convenient centralized management and one-touch smart control capabilities. + +**User06:** It is recommended that a telepresence system provide harmonized environment for assuring immersive presences of remote users. Typically, in order to provide immersive and realistic experiences to users, some environmental factors are aligned between local and remote locations. + +These environmental factors include: interior design aspects such as the desk shape, wall colour, illumination, or lighting position, etc. + +**User07:** It is recommended that a telepresence system support multiple video sources in each meeting room. It is recommended that these video sources provide a seamless view of the conference participants. + +**User08:** It is recommended that a telepresence system support multiple screens in each meeting room. It is recommended that the gap width between neighbouring displays be minimized. Furthermore it is recommended that the output images on neighbouring displays be continuous across the display frame borders (either physical or virtual), if they exist. + +Figure 10 illustrates the continuity requirement. + +Figure 11 shows the effects of gap width on the display of images. + +![Three computer monitors side-by-side. A single diagonal line is drawn across all three screens, demonstrating image continuity across frame borders.](be217a121b8cc1b82eb1598749372865_img.jpg) + +Three computer monitors side-by-side. A single diagonal line is drawn across all three screens, demonstrating image continuity across frame borders. + +Continuous images across frame borders + +![Three computer monitors side-by-side. A diagonal line is drawn across the screens, but it is broken at the gaps between the monitors, demonstrating non-continuous images across frame borders.](0a5acc4b370bb711096e04f25b8b3feb_img.jpg) + +Three computer monitors side-by-side. A diagonal line is drawn across the screens, but it is broken at the gaps between the monitors, demonstrating non-continuous images across frame borders. + +Non-continuous images across frame borders F.734(14)\_F10 + +**Figure 10 – User experience: image continuity** + +![A single wide image showing four people in a meeting around a table, labeled as the 'Original image'.](2224b82995b3ba31aa82f20fb06f4c9c_img.jpg) + +A single wide image showing four people in a meeting around a table, labeled as the 'Original image'. + +Original image + +![The original meeting image split across two monitors with a wide black border between them. The image content is cut off at the edges of the monitors.](1e9fc8e561a3ee72410680d44728ba60_img.jpg) + +The original meeting image split across two monitors with a wide black border between them. The image content is cut off at the edges of the monitors. + +Wide border: Continuous image showing visual data loss in the screen border region. + +![The original meeting image split across two monitors with a very narrow black border between them. The image content appears more continuous across the gap.](acb87e7f97704a4ae45a4cbf5f5e8670_img.jpg) + +The original meeting image split across two monitors with a very narrow black border between them. The image content appears more continuous across the gap. + +Narrow border: Continuous image showing minimal visual data loss in the screen border region. + +F.734(14)\_F11 + +**Figure 11 – User experience: gap minimization** + +**NOTE 2** – In some cases, the images from the received video captures overlap and in other cases they are separated. In all of these cases, the displays may not be able to provide a continuous view of the conference participants without processing the images (e.g., introducing a virtual border, shifting, scaling and cropping, or other methods). It may also not be possible to provide image continuity when physically different screens, in terms of their own characteristics and/or their spatial placement, are used to display the image. + +**User09:** It is required that a telepresence system provide natural response for facial expression and conversational voice. + +**User10:** It is recommended that a telepresence system allow the receiver to switch captures between displays and assign desirable display positions for them (either automatically or via user input). + +**User11:** It is recommended that a telepresence system indicate detailed information associated with a composed capture including the list of originating sources and the policy of the composition. + +**User12:** A telepresence system can optionally provide each participant with an experience of being present in the same virtual room, maintaining consistent spatial relationships among all the participants. + +# **8 Control Functional requirements** + +This clause specifies a number of functional requirements of the telepresence system in different categories of control functions including call control functions, media control functions, conference control functions, collaboration functions, and other functions. + +Call control functions are those functions used to establish, modify and release a session in a telepresence system. Media control functions are those functions used to support different media streams including the description and negotiation of distinct capabilities of media, a method for describing the spatial arrangement of media streams, and addition/deletion of media streams. Conference control functions are those functions used to manage the display mode of screens, control cameras, support add/delete participants, switch views, switch meeting room (endpoint), or request information about the conference. Finally, collaboration functions are those functions used to provide additional applications for collaborating with other endpoints. + +## **8.1 Call control functions** + +**Call01:** It is required that a telepresence system support a method for negotiating, establishing, modifying and releasing a telepresence session between two or more endpoints/MCUs. Thus a mechanism for determining whether or not an endpoint or MCU is capable of telepresence is required. + +## **8.2 Media control functions** + +**Med01:** It is required that a telepresence system support the use of video with different aspect ratios between endpoints. + +**Med02:** It is required that a telepresence system support a method for describing the spatial arrangement of audio and video streams in a manner which enables a satisfactory reproduction at the receiver in a spatially correct manner. Furthermore it is required to support a method to enable a satisfactory spatial matching between audio and video streams coming from the same endpoints. + +This requirement encompasses the requirements REQMT-1, REQMT-2 and REQMT-3 as defined in [b-IETF RFC 7262]. + +**Med03:** It is recommended that a telepresence system support a method to indicate that the spatial information regarding a capture is dynamic (i.e., may change during the session) and/or a method of updating the spatial information. + +**Med04:** It is recommended that a telepresence system support the ability for endpoints to send and receive multiple presentation streams. + +**Med05:** It is recommended that a telepresence system support multiple simultaneous presentation streams from different endpoints. + +**Med06:** It is required that a telepresence system provide interoperability between endpoints which send and receive different numbers of media streams. This requirement encompasses requirement REQMT-9 as defined in [b-IETF RFC 7262]. + +**Med07:** It is recommended that a telepresence system be able to add additional media streams, and remove existing media streams during the telepresence session. + +**Med08:** It is recommended that a telepresence system provide a suitable range of video frame rates, resolutions, and bit rates for media streams as well as the shared data. + +**Med09:** A non-mixing mode of operation for MCUs connecting telepresence endpoints is recommended. + +**Med10:** It is recommended that a telepresence system advertise a set of media characteristics suitable for use by various types of devices. + +**Med11:** It is recommended that a telepresence system limit its advertised set of media characteristics to ensure a suitable user experience for the application (for instance ensuring high quality video for telemedicine) + +**Med12:** It is required that a telepresence system support interoperability with other devices that send or receive a different number of media streams. + +**Med13:** It is required that a telepresence system support the description, identification and negotiation of appropriate information to enable spatially coordinated rendering of audio and video streams. + +## **8.3 Conference control functions** + +The requirements in this clause relate to conference control functions that are stimulated either through direct user interaction or through policies with prior user input. These conference control functions are grouped into several areas: chair control, media rendering, meeting arrangement and endpoint control. + +The requirements below indicate requirements for a user. These also apply to a user when the user is designated as the conference chair. In some use cases the requirements may be limited to users who are designated as conference chair. + +### **8.3.1 Chair control** + +Chair control requirements relate to the management of a "chair" function that provide a mechanism to control how resources are used in a conference. + +**Con01:** It is recommended that a telepresence system support a mechanism for floor control. It should be possible for a user to: + +- **Con01a:** apply to be floor chair, +- **Con01b:** apply to the floor chair for permission to speak, +- **Con01c:** release the chairmanship to allow another user to take the chair, +- **Con01d:** receive the list of endpoints/persons applying to speak, and +- **Con01e:** remove floor control from the conference. + +### **8.3.2 Media rendering** + +Media rendering requirements are those related to the control of the content and the description of media streams within a conference and how these media streams are rendered. + +**Con02:** It is recommended that a telepresence system enable a user to: + +- **Con02a:** Set information regarding the content of media captures and which captures are advertised. +- **Con02b:** Select which captures are consumed by the local endpoint. This may be through user interaction or automatically as the result of policy. +- **Con02c:** Select a particular local rendering layout/policy. For example: control what is displayed when multiple endpoints/captures are in a conference. This may be all the remote participants (including non-telepresence participants) or a subset. +- **Con02d:** Set which endpoints and their captures may be distributed in the conference. +- **Con02e:** Set a particular endpoint as an endpoint from which all other endpoints in the conference receive media from. + +- **Con02f:** Set the switching policy for media distributed in the conference. Example policies include voice controlled switching with a voice activity threshold to control which media is distributed, or whether all or a subset of endpoints/captures are switched. +- **Con02g:** Set a composition policy to control how media is combined from two or more streams into a single stream. +- **Con02h:** Set a policy to control autonomous operation of the telepresence system with respect to switching and composition. +- **Con02i:** Indicate whether a particular stream is related to a presentation and to control which endpoints can send presentation streams. + +### 8.3.3 Meeting arrangement + +Meeting arrangement requirements are those related to the initiation, maintenance and ending of the overall conference session. + +**Con03:** It is recommended that a telepresence system enable a user to: + +- **Con03a:** Schedule a conference, provide meeting information and invite participants. +- **Con03b:** Start a conference, to enable users/endpoints to join a conference. +- **Con03c:** Lock a conference to ensure extra users/endpoints cannot join an active conference. +- **Con03d:** Extend a conference past its scheduled time. +- **Con03e:** End a conference, which results in the release of resources associated with the conference. +- **Con03f:** Receive details regarding the conference, including the conference name and list of the participants and who is conference chair. + +### 8.3.4 Endpoint control + +Endpoint control requirements are those related to managing the connection of endpoints to a conference and the control of endpoint resources. + +**Con04:** It is recommended that a telepresence system enable a user to: + +- **Con04a:** Connect one or more endpoints to a conference by calling the endpoint. +- **Con04b:** Disconnect an endpoint that is currently connected to a conference. For example, the procedures described by [ITU-T H.243]. +- **Con04c:** Add an endpoint to the conference list. +- **Con04d:** Mute/unmute endpoints at the local and/or remote endpoint(s). +- **Con04e:** Control a remote camera (FECC) and its capture area. + +## 8.4 Collaboration functions + +Collaboration functions are those functions used to provide additional facilities for collaborating with other endpoints. + +**Col01:** A telepresence system can optionally provide one or more means of collaboration such as remote presentation, instant messaging, online documentation, whiteboard and file transfer based on existing protocols. + +**Col02:** A telepresence system can optionally support a captioning function. + +## 8.5 Other functions + +This clause contains requirements that are not related to the other clauses in clause 8. + +**Other01:** It is required that a telepresence management system be able to provide various statistical information about a telepresence conference session, both during and at the end of the conference, which includes, but is not limited to: the media type(s) used, the numbers of endpoints, the session duration and the data volume of each media type. Depending on the information required, the telepresence management system may collect the information from multiple different telepresence system entities ( e.g., call resource controller, MCU and endpoints). + +NOTE – There may be other requirements for the generation of local statistics, e.g., for the consumption of local users and/or local endpoint management systems. As these statistics are local in scope they are not detailed by this Recommendation. + +**Other02:** It is recommended that a telepresence system provide QoS/QuE information, including media network utilization, network delay, loss rate and jitter. + +# **9 Interoperability requirements** + +## **9.1 Interoperation with traditional systems** + +This clause presents requirements for interoperation with legacy devices or systems. When used in a conference with telepresence system these legacy devices might not provide a telepresence experience. + +**Int01:** It is required that a telepresence system supports the participation in the same conference of both traditional videoconferencing endpoints and telepresence endpoints. + +**Int02:** It is recommended that a telepresence system support connection to a traditional videoconferencing system in a cascaded conference mode. + +**Int03:** It is recommended that a telepresence system allow audio only legacy devices to participate in a conference. + +## **9.2 Interoperation between telepresence systems** + +This clause presents requirements for interoperation with devices or systems that have been enhanced for telepresence. + +**Int04:** It is required that a telepresence system enable audio and video terminals based on different open standards, different software and/or hardware architectures to participate in the same conference. + +**Int05:** It is required that a telepresence system provide a telepresence experience between telepresence endpoints and devices based on different open standards when participating in the same conference. For example: A telepresence enhanced SIP endpoint and a telepresence enhanced H.323 endpoint via control signalling gateway. + +**Int06:** It is required that a telepresence system allow telepresence endpoints and devices residing in different networks to participate in the same conference. This includes cases of intra and inter operator networks, and also between an operator network and an enterprise network. + +**Int07:** It is recommended that a telepresence systems support interoperability between endpoints with screens of different resolutions. + +# **10 Network requirements** + +**Net01:** It is recommended that a telepresence system enable reservation of network resources for assuring QoS for the telepresence session. + +**Net02:** It is recommended that a telepresence system enable adaptation of the quality of media based on the network status. For example, under a best-effort network such as the Internet, which cannot + +provide strictly guaranteed network QoS, the telepresence system may need to manipulate its video quality based on network status. + +**Net03:** It is recommended that a telepresence system provide a means for endpoints to participate in telepresence conferences when some of telepresence system components are located in one or more private networks. + +NOTE – Signalling and media may be subject of NAT or firewall traversal techniques to assure connectivity of telepresence services. Such techniques should be applied automatically with minimal user operation. + +**Net04:** It is required that a telepresence system not preclude support for both IPv4 and IPv6. + +# **11 Security requirements** + +**Sec01:** A telepresence system can optionally support a security mechanism for securing sessions. + +**Sec02:** A telepresence system can optionally support a negotiation mechanism for negotiating the characteristics of the secured session. + +**Sec03:** A telepresence system can optionally support both signal security and media security. + +**Sec04:** A telepresence system can optionally support authentication of the endpoints. + +# Bibliography + +[b-IETF RFC 7205] IETF RFC 7205 (04/2014), *Use Cases for Telepresence Multistreams*. + +[b-IETF RFC 7262] IETF RFC 7262 (06/2014), *Requirements for Telepresence Multistreams*. + + + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|---------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | 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0000000000000000000000000000000000000000..bc7a7044c96b3eb85464572708318df2a202c898 --- /dev/null +++ b/marked/F/T-REC-F.735.2-202106-I_PDF-E/raw.md @@ -0,0 +1,2305 @@ + + +International Telecommunication Union + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**F.735.2** + +(06/2021) + +SERIES F: NON-TELEPHONE TELECOMMUNICATION +SERVICES + +Multimedia services + +--- + +**Architecture and protocols for software-defined +cameras** + +Recommendation ITU-T F.735.2 + +ITU-T + +![ITU logo](1d7527f4316cfe2d342b08d1653d1592_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with a white grid pattern, overlaid by a stylized 'ITU' text in blue. + +ITU logo + +# ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +## **TELEGRAPH SERVICE** + +| | | +|-----------------------------------------------------------------|-------------| +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | + +## **MOBILE SERVICE** + +| | | +|--------------------------------------------------------|-------------| +| Mobile services and multdestination satellite services | F.110–F.159 | +|--------------------------------------------------------|-------------| + +## **TELEMATIC SERVICES** + +| | | +|-------------------------------------------|-------------| +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | + +## **MESSAGE HANDLING SERVICES** + +| | | +|--|-------------| +| | F.400–F.499 | +|--|-------------| + +## **DIRECTORY SERVICES** + +| | | +|--|-------------| +| | F.500–F.549 | +|--|-------------| + +## **DOCUMENT COMMUNICATION** + +| | | +|--------------------------------------|-------------| +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | + +## **DATA TRANSMISSION SERVICES** + +| | | +|--|-------------| +| | F.600–F.699 | +|--|-------------| + +## **MULTIMEDIA SERVICES** + +| | | +|--|--------------------| +| | F.700–F.799 | +|--|--------------------| + +## **ISDN SERVICES** + +| | | +|--|-------------| +| | F.800–F.849 | +|--|-------------| + +## **UNIVERSAL PERSONAL TELECOMMUNICATION** + +| | | +|--|-------------| +| | F.850–F.899 | +|--|-------------| + +## **ACCESSIBILITY AND HUMAN FACTORS** + +| | | +|--|-------------| +| | F.900–F.999 | +|--|-------------| + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.735.2 + +# Architecture and protocols for software-defined cameras + +## Summary + +As defined in Recommendation ITU-T F.735.1, software-defined cameras can provide the basic hardware service application programming interfaces (APIs) and the common software service APIs for application developers; these APIs are called "service-oriented interfaces". Through these APIs the upper layer applications can obtain raw video, pan/tilt/zoom (PTZ), common software and hardware resource to realize video intelligent analysis and non-intelligent businesses. Recommendation ITU-T F.735.2 specifies the architecture and service-oriented interface protocols for software-defined cameras, including functional architecture of software-defined camera system, service-oriented interface message protocol structure, and service-oriented interface protocols. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.735.2 | 2021-06-13 | 16 | 11.1002/1000/14678 | + +## Keywords + +Service-oriented interface, software-defined camera. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2021 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|---------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Architecture of an SDC system ..... | 2 | +| 6.1 Functional architecture of an SDC system ..... | 3 | +| 6.2 Service-oriented interface architecture and classification..... | 4 | +| 7 SDC SOI message protocol structure ..... | 6 | +| 7.1 SDC SOI access mechanism definition..... | 6 | +| 7.2 Message specification (HBTP)..... | 7 | +| 7.3 SOI message description format..... | 9 | +| 8 Protocols of service-oriented interface ..... | 9 | +| 8.1 Video service API..... | 9 | +| 8.2 Algorithm inference API ..... | 20 | +| Appendix I – Data Type Definition and API Example..... | 25 | +| I.1 SOI data type definition example ..... | 25 | +| I.2 Video service API example ..... | 26 | +| I.3 Algorithm inference example ..... | 34 | +| Bibliography..... | 39 | + + + +# Recommendation ITU-T F.735.2 + +## Architecture and protocols for software-defined cameras + +# 1 Scope + +Service-oriented interfaces are those APIs that are provided by the software-defined camera (SDC) operating system (OS) for the upper application developer to invoke the hardware and common software resources including raw video, algorithms inference, event, pan/tilt/zoom (PTZ), etc. to complete the intelligent analysis application development. The upper application layer can also obtain raw video, PTZ, common software and hardware resources through these APIs to complement intelligent analysis and non-intelligent business of monitoring. This Recommendation specifies the architecture and protocols for software-defined cameras, including the functional architecture of an SDC system, the service-oriented interface message protocol structure, and service-oriented interface protocols. + +The scope of this recommendation includes: + +- 1) Architecture of SDC systems; +- 2) SDC service-oriented interface (SOI) message protocol structure; +- 3) Protocols of service-oriented interface. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T F.735.1] Recommendation ITU-T F.735.1 (2020), *Requirements for software-defined cameras*. + +[ITU-T F.743.1] Recommendation ITU-T F.743.1 (2015), *Requirements for intelligent visual surveillance*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following term defined elsewhere: + +**3.1.1 software-defined camera** [ITU-T F.735.1]: Software-defined camera is a kind of IPU (see [ITU-T F.743.1]), which provides a technical approach to decouple hardware and software and to support algorithms' on-demand deployment, online upgrade without services interrupting, continuous self-adaptive learning to adapt to various scenarios. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 SDC studio**: A software-defined camera (SDC) algorithm warehouse that is deployed in a cloud server and which supports service including centralized artificial intelligence model training, + +intelligent algorithms online development, algorithm integration verification, application packing and release. + +**3.2.2 SDC controller:** A client located in the front-edge of a video surveillance system, and which acts as an operation centre for massive software-defined cameras (SDCs). The main functions include SDC control (such as restart, stop, configuration, etc.) and algorithm management (such as deployment, upgrade, deletion, etc.). + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-------|-------------------------------------------------------------| +| API | Application Programming Interface | +| FSAAS | File System as a Service | +| HBTP | Hyper Binary Transfer Protocol | +| HTTPS | Hyper Text Transfer Protocol over Secure Socket Layer | +| NNIE | Neural Network Inference Engine | +| NoSQL | Nor only Structured Query Language | +| OS | Operating System | +| PTZ | Pan/Tilt/Zoom | +| SDC | Software-Defined Camera | +| SDK | Software Development Kit | +| SOI | Service-Oriented Interface | +| SQL | Structured Query Language | +| SSH | Secure Shell | +| VENC | Video Encoder | +| VI | Video Input | +| YUV | luminance/luma (Y) – blue luminance (U) – red luminance (V) | + +# 5 Conventions + +In this Recommendation: + +- The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. +- The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus this requirement needs not be present to claim conformance. + +# 6 Architecture of an SDC system + +The overall functional architecture of SDC is defined in [ITU-T F.735.1]. This clause describes the whole functional architecture for an SDC system and the detailed service-oriented interface architecture. + +## 6.1 Functional architecture of an SDC system + +### 6.1.1 Overview of entities + +The SDC system functional architecture could be decomposed into three units as follows. The architecture is illustrated in Figure 6-1. + +- SDC studio (SDCS) +- SDC controller (SDCC) +- SDC + +![Functional architecture of an SDC system diagram](7a0db9703b68b3d06cdaeefc084c0006_img.jpg) + +The diagram illustrates the functional architecture of an SDC system, organized into three main layers: SDC studio, SDC controller, and SDC. + +- SDC studio:** Located at the top, it contains four functional blocks: "Online AI model training", "Online development integration verification", "App packaging and release", and "App warehouse". +- SDC controller:** Located on the left, it contains three management blocks: "Device management", "Algorithm management", and "Batch management". +- SDC:** The central part of the architecture, divided into three service layers: + - SaaS (Software as a Service):** The top layer, containing an "Application" block and several "Intelligent App" (App 1 to App N) and "Non-intelligent App" (App 1 to App N) blocks. + - PaaS (Platform as a Service):** The middle layer, labeled "SDC OS", which includes "Basic hardware service API", "Common software service API", "Basic hardware function module", "Common software function module", an "App manager", a "Virtualization layer", and a "Kernel". + - IaaS (Infrastructure as a Service):** The bottom layer, labeled "Hardware", which contains a "Hardware/Chip set" block. +- Security:** A vertical column on the right side of the SDC layer, containing four security management blocks: "Data security", "Application security", "System security", and "management security". + +Functional architecture of an SDC system diagram + +F.735.2(21)\_F6-1 + +Figure 6-1 – Functional architecture of an SDC system + +### 6.1.2 SDCS: SDC studio + +SDC studio can provide the algorithm developer a self-contained and efficient development platform, and can also provide the SDC user an algorithm warehouse from where the needed algorithm can be downloaded and deployed in specific SDC devices. The functions of such platform include AI model training, verification, online development, testing, etc. The detailed functions are as follows: + +- AI model training and transfer: training AI model using the specific train data and providing AI model conversion tool to complete model conversion. +- Online algorithm development: supporting online algorithm development that is based on the SDC OS service APIs. +- Algorithm integration and verification: supporting specific algorithm tested and deployed in the test environment of SDC to verify the function of this algorithm. +- Algorithm packaging and release: providing tools to complete algorithm packaging. +- Algorithm warehouse: supporting app licence management, app reviewing and app billing, etc. + +### 6.1.3 SDCC: SDC controller + +The SDC controller is a client deployed in the front-end of the surveillance system. It creates connections with SDCs and SDC studio, which acts as an operation centre for SDC management, + +including camera configuration, user management, device control, and algorithm life cycle management. It is recommended that the whole management operation support batch operation. The detailed functions are as follows: + +- Algorithm download: accessing the SDC studio and downloading a specific algorithm. +- Device control: video live streaming, PTZ control, image capture, recording, etc. +- User management: identification and authentication, access control, authorization, etc. +- Device configuration: protocol access parameter configuration, alarm configuration, PTZ configuration, basic video streaming configuration, etc. +- Algorithm life cycle management: algorithm deployment, activating, deactivating, upgrade and deletion in SDC. + +### 6.1.4 SDC + +The architecture of SDC is already defined in [ITU-T F.735.1], and the security function is added in Figure 6-1 to provide a full explanation of SDC. The security management contains data security, application security, system security and management security. + +The security management components provide: + +- Data security: data integrity verification, encrypted storage of sensitive data, system data backup, key security, etc. The data type including image, intelligent metadata (such as vehicle attribute, object detection result, the extraction feature of a human body, etc.) and alarm data in the SDC. +- Application security: installation package (APP) integrity verification, application authorization and authentication, application licence management, etc. +- System security: provision of the necessary measures to achieve system security. This includes performing authority management and control on SDC key data to prevent users from unauthorized operation, providing a digital signature and verification tool for algorithm package integrity verification and anti-hacking. +- Management security: supporting remote maintenance security (such as using hypertext transfer protocol over secure socket layer (HTTPS) and secure shell (SSH) protocol when logging into in the SDC, during sensitive data transmission, etc.) and ensuring account and password security. + +For the functions of SDC hardware, SDC OS, and application layer, please refer to clause 7 in [ITU-T F.735.1]. + +## 6.2 Service-oriented interface architecture and classification + +### 6.2.1 Service-oriented interface architecture + +The software-defined camera (SDC) software architecture consists of the following layers, which are illustrated in Figure 6-2: + +- Customized service software layer: Provides a variety of service functions required by end users and supports on-demand service loading. +- Common software capability service layer: Provides support for the service software layer to accelerate the production of various customization scenarios and innovative services. The common software capabilities can be loaded on demand. +- Basic hardware capability service layer: Provides interfaces for using underlying hardware resources. All basic hardware capabilities at this layer are based on the SDC hardware capability. + +- SDC service-oriented interface layer: Defines the specifications of communication interfaces among capability service layers to achieve robust simplicity, high efficiency and excellent scalability. + +![Figure 6-2 – Architecture of SDC software. The diagram shows a layered architecture. At the top is the 'Customized service software layer', which contains two boxes: 'Intelligent App' (with Person recognition, Water pollution detection, Intelligent transportation, Construction site safety detection, Licence plate recognition, etc.) and 'Non-intelligent App' (with Video recording, Live video, Alarm APP, PTZ APP, ITU-T H.626 and ITU-T H.627 access, SDC private SDK server, OVNI access, etc.). Below this is a red horizontal line labeled 'Service-oriented interface of SDC'. Below the interface are two boxes: 'Basic hardware capability service layer' (with Video service, Codec service, Crypto service, Algorithm service, PTZ service, etc.) and 'Common software capability service layer' (with Portal service, Gateway API, APP management, Storage management, Event management, etc.). Red double-headed arrows connect the apps to the interface, and the interface to the service layers.](5b4e774d63e0e0ed73801a9247755e5f_img.jpg) + +Figure 6-2 – Architecture of SDC software. The diagram shows a layered architecture. At the top is the 'Customized service software layer', which contains two boxes: 'Intelligent App' (with Person recognition, Water pollution detection, Intelligent transportation, Construction site safety detection, Licence plate recognition, etc.) and 'Non-intelligent App' (with Video recording, Live video, Alarm APP, PTZ APP, ITU-T H.626 and ITU-T H.627 access, SDC private SDK server, OVNI access, etc.). Below this is a red horizontal line labeled 'Service-oriented interface of SDC'. Below the interface are two boxes: 'Basic hardware capability service layer' (with Video service, Codec service, Crypto service, Algorithm service, PTZ service, etc.) and 'Common software capability service layer' (with Portal service, Gateway API, APP management, Storage management, Event management, etc.). Red double-headed arrows connect the apps to the interface, and the interface to the service layers. + +F.735.2(21)\_F6-2 + +**Figure 6-2 – Architecture of SDC software** + +### 6.2.2 Service-oriented interface classification + +The SDC service-oriented interface can be classified into two types: the basic hardware capability service APIs and the common software capability service APIs. + +#### Basic hardware capability service APIs + +The basic hardware capability service APIs provide interfaces for using SDC hardware resources, including but not limited to getting the raw video (such as YUV frame), invoking the algorithm model inference, controlling the SDC PTZ, etc. For the function description of these service, see Table 6-1. + +NOTE – YUV is abbreviation for "Luminance (Luma) / blue luminance (U) / red luminance (V)" that is a type of colour encoding representation historically used in analogue systems, such as colour components in SECAM and PAL colour spaces. + +**Table 6-1 – Basic hardware capability service interfaces** + +| Service name | Function description | +|---------------------|----------------------------------------------------------------------------------------------| +| Video service | Provides the function of subscribing to intelligent algorithm input data – video stream data | +| Codec service | Provides the codec function for media chips | +| Crypto service | Provides the encryption and decryption functions supported by the bottom-layer chip | +| Algorithm service | Provides the function of loading and calculating algorithm model files for AI chips | +| PTZ control service | Provides the pan-tilt-zoom (PTZ) control function | + +#### Common software capability service APIs + +The common software capability service APIs are used to provide the common software capabilities of the camera which include API gateway interface, event management, security, log, etc. For the function description of these services, see Table 6-2. + +**Table 6-2 – Common software capability service interfaces** + +| Service name | Function description | +|--------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| App management | Provides app lifecycle management capabilities, such as app installation, uninstallation, enabling, disabling, starting, stopping, and watchdog. | +| Event management | Provides flexible event subscription mechanisms, and implements common capabilities of releasing and subscribing to event data based on the zero-copy mechanism. | +| Storage management | Provides the functions of managing disk partitions and storing NoSQL and SQL statements. | +| Portal service | Provides a unified entry for web pages of all SDC apps and the SDC OS. The entry is a human-machine interface. | +| Gateway API | Provides a unified entry for northbound software development kits (SDKs) of all SDC apps and the SDC OS. The northbound SDK provides the service from SDC to client. | + +# 7 SDC SOI message protocol structure + +## 7.1 SDC SOI access mechanism definition + +This clause specifies the invocation mechanism of service-oriented interfaces (SOIs). This invocation are instructions for using a file operating interface that is called file system as a service (FSAAS). All the methods are illustrated in Table 7-1. A user can invoke the **open** interface to open the file corresponding to a service and obtain the read/write handle. Then user can invoke the **read/write** interface to interact with the service. The operation for invoking the **open** interface is similar to that for setting up a TCP socket link. All the service files are located in the "/mnt/srvfs" directory in the camera system, and the service name is the file name. For example, the raw video service provided by the basic hardware capability service layer is located in the "/mnt/srvfs/video.iaas.sdc" file, this file directory address is the service URI of this raw video service interface. + +**Table 7-1 – The invocation methods of SOI** + +| Methods | Description | +|---------|--------------------------------| +| Open | Get service handle | +| Read | Get service response | +| Write | Execute operation of interface | +| Close | Close service handle | + +The example of invoking the video service API which contains the raw video (YUV frame data) registration and subscription is shown in Figure 7-1, the variable "serviceHandle" is the video service handle, while the methods "open, write, read and close" are used to operate the service handle like file system operation. This flow is the invocation mechanism of SDC service-oriented interface. + +![](af7916c89a458fdab6c3f443217388ae_img.jpg) + +``` + +sequenceDiagram + participant Client + participant Service + Client->>Service: serviceHandle=Open +file("/mnt/srvfs/video.iaas, sdc, O_RDWR") +Function: Get the service handle + Note over Client, Service: Request message: Content1 + Client->>Service: Write(fd, content1, length1) +Function: invoke the video service API + Service-->>Client: Result=read(ft, content2, length2) +Function: Get the service response + Note over Client, Service: Response message: Content2 + Client->>Service: Close(serviceHandle) +Function: close service + +``` + +F.735.2(21)\_F7-1 + +**Figure 7-1 – Procedure flow of raw video service invocation** + +## 7.2 Message specification (HBTP) + +This clause defines the message specification named hyper binary transfer protocol (HBTP) of such SDC SOI, which is shown in Figure 7-2. A message contains a maximum of three parts: common header, extension header and message content. The extension header and message content are optional. For details about the message content and extension header of each service interface, see the corresponding interface definition subclause in clause 8. + +![](cab0834804fb031b43865554cc8d06ab_img.jpg) + +| | | | +|---------------------------|-----------------------------|----------------------------| +| Common header (Mandatory) | Extension header (Optional) | Message content (Optional) | +|---------------------------|-----------------------------|----------------------------| + +F.735.2(21)\_F7-2 + +**Figure 7-2 – HBTP of SDC SOI** + +NOTE – The message structures of the following service-oriented interfaces are defined according to the network order (high bytes stored in lower memory locations). + +#### Common header + +The common header is defined according to the network order (big endian) as shown in Figure 7-3. + +| | | | | | | | | +|--------------------------|--|--|--|--------------------|--|---|-----------------| +| version (2 bytes) | | | | url-ver (1 byte) | | R | method (7 bits) | +| url (2 bytes) | | | | code (2 bytes) | | | | +| head_length (2 bytes) | | | | trans-id (2 bytes) | | | | +| content_length (4 bytes) | | | | | | | | + +F.735.2(21)\_F7-3 + +**Figure 7-3 – Common header definition of SDC SOI** + +The definition of common header fields is shown in Table 7-2. The data structure can be defined based on the endian macro definition of the GCC; for an example, please refer to clause I.1.1. + +**Table 7-2 – Common header field definition** + +| Field | Length | Semantics | +|----------------|---------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| version | 2 bytes | Protocol version. Currently, the field has the fixed value of 0x5331 . | +| url_ver | 1 byte | Interface version compatibility. | +| R | 1 bit | Indicates whether a message is a request or response. The value 1 indicates response. | +| method | 7 bits | Method definition.
1: CREATE
2: GET
3: UPDATE
4: DELETE | +| url | 2 bytes | Resource ID | +| code | 2 bytes | Response code (valid only when R is set to 1 ) | +| head_length | 2 bytes | Total length of the common header and extension header | +| trans-id | 2 bytes | Transaction ID. The trans_id field in the service response header corresponds to the trans_id field in the request. In the pipeline scenario similar to HTTP, the server cannot ensure that the sequence of the response and request is consistent. The client can match the request and the response based on this field. | +| content_length | 4 bytes | Total length of the message content | + +#### Extension header + +The specific type of the extension header and the definition of the data structure corresponding to this type of extension header are determined by each service interface defined in clause 8. The total length is aligned by 8 bytes. The extension header definition is illustrated in Figure 7-4. + +![](bd671b21db63e6fdb2196e9b18502aac_img.jpg) + +| | | +|--------------------------|------------------| +| type (2 bytes) | length (2 bytes) | +| reserve (4 bytes) | | +| Extension header content | | +| Extension header content | padding | + +F.735.2(21)\_F7-4 + +**Figure 7-4 – Extension header definition of SDC SOI** + +The definition of extension header fields is shown in Table 7-3. The data structure can be defined based on the endian macro definition of the GCC, for the example please refer to clause I.1.2. + +**Table 7-3 – Extension header field definition** + +| Field | Length | Semantics | +|--------------------------|--------------------------------|----------------------------------------------------------------------------------------| +| type | 2 | The specific type is defined by each service | +| length | 2 | Total length of the extension header and its content, excluding the padding character. | +| Extension header content | hdr_len - 8 | Actual message body content carried | +| padding | ((hdr_len + 7) & ~7) – hdr_len | Ensure that the data of the entire extension header is 8-byte aligned | + +## 7.3 SOI message description format + +The SOI message description is illustrated in Table 7-4. The field URI is the "url-ver" field in common header, the detailed definition of common header and extension can refer to clause 7.2. The methods CREATE, GET, UPDATE and DELETE are used in common header to complete the corresponding operation to SOI services. The message content is the specific message as defined in clause 8. + +**Table 7-4 – SOI message description format** + +| | | | | | +|----------------------|------------------------------------|----------------|-------------------------|----------------| +| Function | The interface function description | | | | +| URI | URI Description | | URI Value | | +| | | | | | +| Request | | | Response | | +| Common header | Extension header | Content | Extension header | Content | +| Method | | | | | +| Response code | | | | | + +# 8 Protocols of service-oriented interface + +This clause defines the video service APIs and the algorithm APIs which are essential APIs for algorithm developer to get raw video frame data and execute algorithm inference. With the algorithm inference APIs, the developer can invoke the deep learning inference ability of the AI chip and realize neural network model inference. + +## 8.1 Video service API + +### 8.1.1 Video service function definition + +The processing of the raw video which is generated from a sensor is illustrated in Figure 8-1. The raw video is changed to a YUV frame after the processing in the video process function model, and after encoding the video data is converted to ENC frame data. The video service is aimed to support the YUV or video encoder (VENC) video data subscription capability. This clause specifies the YUV and VENC video data subscription, release function and image capture function. + +![Flowchart of raw video processing procedure in SDC. The process starts with a Sensor providing a RAW frame to a VI (Video Interface) block. The VI block outputs a YUV frame to a VPSS (Video Processing and Scaling) block. The VPSS block outputs a YUV frame to a VENC (Video Encoder) block. The VENC block outputs an ENC frame. The entire process is labeled 'video.iaas.sdc'.](a7c51c18111139f9aca2805114108565_img.jpg) + +``` + +graph LR + Sensor[Sensor] -- "RAW frame" --> VI[VI] + VI -- "YUV frame" --> VPSS[VPSS] + VPSS -- "YUV frame" --> VENC[VENC] + VENC -- "ENC frame" --> Output[ ] + subgraph video.iaas.sdc + VI + VPSS + VENC + end + style Output fill:none,stroke:none + +``` + +Flowchart of raw video processing procedure in SDC. The process starts with a Sensor providing a RAW frame to a VI (Video Interface) block. The VI block outputs a YUV frame to a VPSS (Video Processing and Scaling) block. The VPSS block outputs a YUV frame to a VENC (Video Encoder) block. The VENC block outputs an ENC frame. The entire process is labeled 'video.iaas.sdc'. + +**Figure 8-1 – Raw video processing procedure in SDC** + +### 8.1.2 Video logical channel definition + +There are two types of channels. One is the YUV video frame data channel that is not compressed. The other is the VENC frame (H.264/H.265) channel. Users can query the attributes and usage status of each channel and set the data output format depending on their needs. If there are multiple users, the users need to collaborate with each other to eliminate potential channel resource and configuration conflicts. + +#### 8.1.2.1 YUV logical channel definition + +For the definition and channel number value of YUV logical channel, see Table 8-1. + +**Table 8-1 – YUV logical channel definition** + +| Resource | Type | Channel number value range | +|----------------------------|-------------|-----------------------------------| +| YUV snapshot frame channel | uint32 | 0 | +| YUV frame data channel | uint32 | 1–99 | + +NOTE – The channel number is obtained through the YUV logical channel attribute query interface. The number of channels supported by different hardware devices varies. + +#### **8.1.2.2 VENC logical channel definition** + +For the definition and channel number value of VENC logical channel, see Table 8-2. + +**Table 8-2 – VENC logical channel definition** + +| Resource | Type | Channel number value range | +|-------------------------|-------------|-----------------------------------| +| VENC frame data channel | uint32 | 100–104 | + +NOTE – The channel number is obtained through the YUV logical channel attribute query interface. The number of channels supported by different hardware devices varies. + +### **8.1.3 YUV logical channel attribute setting** + +#### **8.1.3.1 YUV logical channel attribute setting** + +**Table 8-3 – YUV logical channel attribute setting interface definition** + +| | | | | | | +|----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|-------------------------|------------------|------| +| Function | YUV logical channel attribute setting | | | | | +| URI | URI Description | | | URI Value | | +| | SDC/URL/YUV/CHANNEL | | | 0 | | +| Request | | | Response | | | +| Common header | Extension header | Content | Extension header | Content | | +| Method | UPDATE | None | sdcd_yuv_channel_param | None | None | +| Response code | If the function is normal, response code 200 is returned. If an input error occurs, response code 400 is returned. If a server error occurs, response code 500 is returned. | | | | | + +The YUV logical channel attribute setting interface definition is illustrated in Table 8-3. + +#### **8.1.3.2 Content definition** + +###### **8.1.3.2.1 sdc\_yuv\_channel\_param** + +The sdc\_yuv\_channel\_param data structure definition is illustrated in Table 8-4. + +**Table 8-4 – sdc\_yuv\_channel\_param definition** + +| Element name | Type | Description | +|---------------------|-------------|------------------------| +| channel_number | uint32 | logical channel number | +| Width | uint32 | resolution | +| height | uint32 | resolution | +| Fps | uint32 | Frame per second | + +**Table 8-4 – sdc\_yuv\_channel\_param definition** + +| Element name | Type | Description | +|--------------|--------|--------------------------------------------------------------------------------------------------------| +| on_off | uint32 | The value 0 indicates that the channel is disabled. Other values indicate that the channel is enabled. | +| format | uint32 | NV12 | + +#### 8.1.3.3 Extension header definition + +None. + +#### 8.1.3.4 Implementation example + +Refer to clause I.2.1. + +#### 8.1.4 YUV logical channel attribute query + +#### 8.1.4.1 YUV logical channel attribute query + +**Table 8-5 – YUV logical channel attribute query interface definition** + +| | | | | | | +|----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------|-----------------|-------------------------|-----------------------| +| Function | YUV logical channel attribute query | | | | | +| URI | URI Description | | | URI Value | | +| | SDC/URL/YUV/CHANNEL | | | 0 | | +| Request | | | Response | | | +| Common header | | Extension header | Content | Extension header | Content | +| Method | GET | None | channel_number | None | sdcd_yuv_channel_info | +| Response code | If the function is normal, response code 200 is returned. If an input error occurs, response code 400 is returned. If a server error occurs, response code 500 is returned. | | | | | + +The YUV logical channel attribute query interface definition is illustrated in Table 8-5. + +#### 8.1.4.2 Content definition + +The data structure definition of "channel\_number" is shown in Table 8-6. For the "sdcd\_resolution" definition, please see Table 8-7, for "sdcd\_yuv\_channel\_info" definition, see Table 8-8. + +##### 8.1.4.2.1 channel\_number + +**Table 8-6 – channel\_number definition** + +| Element name | Type | Description | +|----------------|--------|------------------------| +| channel_number | uint32 | logical channel number | + +##### 8.1.4.2.2 sdcd\_resolution + +**Table 8-7 – sdcd\_resolution definition** + +| Element name | Type | Description | +|--------------|--------|----------------------| +| width | uint32 | Width of resolution | +| height | uint32 | Height of resolution | + +##### 8.1.4.2.3 sdc\_yuv\_channel\_info + +**Table 8-8 – sdc\_yuv\_channel\_info definition** + +| Element name | Type | Description | +|--------------------|-----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| max_resolution | sdc_resolution | Maximum resolution supported by the channel. | +| param | sdc_yuv_channel_param | YUV channel attribute | +| is_snap_channel | uint32 | Indicates whether the channel is a snapshot channel. The options are as follows: 0: common channel; 1: snapshot channel. | +| src_id | uint32 | Data source. The data source uses the IP address to identify the data source (local camera or other cameras) of the channel. For the local multi-lens camera, the data source is identified by 127.0.0.x, where x starts from 1 and is incremented by 1. | +| subscriber_cnt | uint32 | Number of users who subscribe to data of this channel. The value greater than 1 indicates that multiple users subscribe to data of the same channel. Video data is transferred to users in zero-copy mode. If a user modifies the data obtained from this channel, other users will read the data after modification. | +| resolution_moditfy | uint32 | Indicates whether the resolution parameter of the channel can be modified. The options are as follows: 0: no; 1: yes. | + +#### 8.1.4.3 Extension header definition + +None. + +#### 8.1.4.4 Implementation example + +Refer to clause I.2.2. + +#### 8.1.5 YUV frame data subscription + +#### 8.1.5.1 YUV frame data subscription interface + +**Table 8-9 – YUV frame data subscription interface definition** + +| | | | | | | +|----------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------|------------------------------------------|---------------------------|----------------| +| Function | YUV frame data subscription | | | | | +| URI | URI Description | | | URI Value | | +| | SDC_URL_YUV_DATA | | | 1 | | +| Request | | | | | | +| Common header | | Extension header | Content | Extension header | Content | +| Method | GET | Refer to clause 8.1.5.3.1 | channel_number (refer to clause 8.1.4.2) | Refer to clause 8.1.5.3.2 | sdc_yuv_data | +| Response code | If the function is normal, response code 200 is returned. If flow control is enabled, response code 509 (Bandwidth Limit Exceeded) and empty response content are returned. If an input error occurs, response code 400 is returned. If a server error occurs, response code 500 and empty response content are returned. | | | | | + +The YUV frame data subscription interface definition is illustrated in Table 8-9. + +#### 8.1.5.2 Content definition + +For the "sdc\_yuv\_frame" definition, please see Table 8-10, for "sdc\_yuv\_data" definition, see Table 8-11. + +###### 8.1.5.2.1 sdc\_yuv\_frame + +**Table 8-10 – sdc\_yuv\_frame data** + +| Element name | Type | Description | +|--------------|--------|---------------------------------------------| +| addr_phy | uint32 | Physical address | +| addr_virt | uint32 | Virtual address | +| size | uint32 | Size of frame | +| width | uint32 | Width pixel of resolution | +| height | uint32 | Height pixel of resolution | +| stride | uint32 | Image width rounded up, for 16 byte aligned | +| format | uint32 | Frame format | +| reserve | uint32 | Reserve field | + +##### 8.1.5.2.2 sdc\_yuv\_data + +**Table 8-11 – sdc\_yuv\_data** + +| Element name | Type | Description | +|--------------|---------------|----------------------------------------------------------------| +| Channel | uint32 | Channel number | +| Reserve | uint32 | Reserve field | +| Pts | uint32 | Timestamp carried by the bottom-layer chip, in microseconds. | +| Pts_sys | uint32 | Timestamp of the data obtained by the server, in microseconds. | +| Frame | sdc_yuv_frame | sdc_yuv_frame | + +#### 8.1.5.3 Extension header + +###### 8.1.5.3.1 Extension header for request + +The request extension header can be SDC\_HEAD\_YUV\_SYNC, SDC\_HEAD\_YUV\_CACHED\_COUNT\_MAX or SDC\_HEAD\_YUV\_PARAM\_MASK, the definition are as follows: + +- a) SDC\_HEAD\_YUV\_SYNC: Extension header for identifying multi-channel synchronization is illustrated in Figure 8-2. + +![Diagram of the SDC_HEAD_YUV_SYNC extension header structure. It shows a 4-byte header divided into two 2-byte fields. The first 2-byte field is 'Extension header type (0x00)' with a sub-field 'value (0: not synchronize; 1: synchronize)'. The second 2-byte field is 'Extension header length (8)'.](cf4ac1058c52bc3ca37737740afb7f2c_img.jpg) + +| | | | | +|--------------------------------------------|--|-----------------------------|--| +| 2 bytes | | 2 bytes | | +| Extension header type (0x00) | | Extension header length (8) | | +| value (0: not synchronize; 1: synchronize) | | | | + +Diagram of the SDC\_HEAD\_YUV\_SYNC extension header structure. It shows a 4-byte header divided into two 2-byte fields. The first 2-byte field is 'Extension header type (0x00)' with a sub-field 'value (0: not synchronize; 1: synchronize)'. The second 2-byte field is 'Extension header length (8)'. + +F.735.2(21)\_F8-2 + +**Figure 8-2 – Extension header: SDC\_HEAD\_YUV\_SYNC** + +The value is saved in the Reserve field in the extension header. To subscribe to data of multiple channels, if this extension header does not exist, the synchronization policy is used by default. + +- b) SDC\_HEAD\_YUV\_CACHED\_COUNT\_MAX: Extension header for setting the flow control threshold is illustrated in Figure 8-3. + +![Figure 8-3: Extension header structure for SDC_HEAD_YUV_CACHED_COUNT_MAX. The diagram shows a header with two 2-byte fields at the top: 'Extension header type (0x01)' and 'Extension header length (8)'. Below these is a 'value' field representing the maximum number of video frames that can be cached.](83852ec55d4802521a727926336bedab_img.jpg) + +| | | +|-----------------------------------------------------------|-----------------------------| +| 2 bytes                      2 bytes | | +| Extension header type (0x01) | Extension header length (8) | +| value (maximum number of video frames that can be cached) | | + +Figure 8-3: Extension header structure for SDC\_HEAD\_YUV\_CACHED\_COUNT\_MAX. The diagram shows a header with two 2-byte fields at the top: 'Extension header type (0x01)' and 'Extension header length (8)'. Below these is a 'value' field representing the maximum number of video frames that can be cached. + +F.735.2(21)\_F8-3 + +**Figure 8-3 – Extension header: SDC\_HEAD\_YUV\_CACHED\_COUNT\_MAX** + +The value is saved in the Reserve field in the extension header. If this extension header does not exist, the default number of cached video frames on the server is calculated as follows: Sum of frame rates of each channel x 2 (that is, YUV frame resources are occupied for up to 2 s). + +If the total number of cached (not released) video frames exceeds the threshold, the server starts the flow control function and does not forward the subscribed video frame data. Therefore, users need to invoke the interface for releasing YUV frames as needed. + +- c) SDC\_HEAD\_YUV\_PARAM\_MASK: Extension header for subscribing to frame parameters is illustrated in Figure 8-4. + +![Figure 8-4: Extension header structure for SDC_HEAD_YUV_PARAM_MASK. The diagram shows a header with two 2-byte fields at the top: 'Extension header type (0x01)' and 'Extension header length (8)'. Below these is a 'value' field representing the maximum number of video frames that can be cached.](e636d7ccca0ad14c6b95201404324823_img.jpg) + +| | | +|-----------------------------------------------------------|-----------------------------| +| 2 bytes                      2 bytes | | +| Extension header type (0x01) | Extension header length (8) | +| value (maximum number of video frames that can be cached) | | + +Figure 8-4: Extension header structure for SDC\_HEAD\_YUV\_PARAM\_MASK. The diagram shows a header with two 2-byte fields at the top: 'Extension header type (0x01)' and 'Extension header length (8)'. Below these is a 'value' field representing the maximum number of video frames that can be cached. + +F.735.2(21)\_F8-4 + +**Figure 8-4 – Extension header: SDC\_HEAD\_YUV\_PARAM\_MASK** + +The value is saved in the Reserve field in the extension header. If this extension header does not exist, the default number of cached video frames on the server is calculated as follows: Sum of frame rates of each channel x 2 (that is, YUV frame resources are occupied for up to 2 s). + +If the total number of cached (not released) video frames exceeds the threshold, the server starts the flow control function and does not forward the subscribed video frame data. Therefore, users need to invoke the interface for releasing YUV frames as needed. + +##### 8.1.5.3.2 Extension header for response + +The request extension header can be SDC\_HEAD\_YUV\_CACHED\_COUNT, or SDC\_HEAD\_YUV\_PARAM\_SNAP, the definition are as follows: + +- a) SDC\_HEAD\_YUV\_CACHED\_COUNT: Extension header for counting cached video frames, the format definition is illustrated in Figure 8-5. + +![Figure 8-5: Extension header structure for SDC_HEAD_YUV_CACHED_COUNT. The diagram shows a header with two 2-byte fields at the top: 'Extension header type (0x0F)' and 'Extension header length (8)'. Below these is a 'value' field representing the maximum number of cached video frames.](37819f1170c36655c57129b6bd8a5ceb_img.jpg) + +| | | +|-----------------------------------------------|-----------------------------| +| 2 bytes                      2 bytes | | +| Extension header type (0x0F) | Extension header length (8) | +| value (maximum number of cached video frames) | | + +Figure 8-5: Extension header structure for SDC\_HEAD\_YUV\_CACHED\_COUNT. The diagram shows a header with two 2-byte fields at the top: 'Extension header type (0x0F)' and 'Extension header length (8)'. Below these is a 'value' field representing the maximum number of cached video frames. + +F.735.2(21)\_F8-5 + +**Figure 8-5 – Extension header: SDC\_HEAD\_YUV\_CACHED\_COUNT** + +- b) SDC\_HEAD\_YUV\_PARAM\_SNAP: Extension header for snapshot frame parameters, the format definition is illustrated in Figure 8-6. + +![Figure 8-6: Extension header format for SDC_HEAD_YUV_PARAM_SNAP. The diagram shows a header structure with two 2-byte fields at the top: 'Extension header type (0x13)' and 'Extension header length (8)'. Below these is a multi-byte 'Snapshot ID' field. A note indicates that this extension header does not exist in external device trigger mode.](812e188283162af0b54fb3e30ffee51b_img.jpg) + +| | | | | +|----------------------------------------------------------------------------------------------------------------------|--|-----------------------------|--| +| 2 bytes | | 2 bytes | | +| Extension header type (0x13) | | Extension header length (8) | | +| Snapshot ID specified at the service layer (This extension header does not
exist in external device trigger mode) | | | | + +Figure 8-6: Extension header format for SDC\_HEAD\_YUV\_PARAM\_SNAP. The diagram shows a header structure with two 2-byte fields at the top: 'Extension header type (0x13)' and 'Extension header length (8)'. Below these is a multi-byte 'Snapshot ID' field. A note indicates that this extension header does not exist in external device trigger mode. + +F.735.2(21)\_F8-6 + +**Figure 8-6 – Extension header: SDC\_HEAD\_YUV\_PARAM\_SNAP** + +For details about the specified snapshot ID, see the input parameters of the snapshot frame interface in clause 8.1.11. + +#### **8.1.5.4 Implementation example** + +Refer to YUV frame subscription example in clause I.2.3. + +### **8.1.6 YUV frame data release** + +#### **8.1.6.1 YUV frame data release interface** + +**Table 8-12 – YUV frame data release interface definition** + +| | | | | | | +|----------------------|------------------------|-------------------------|----------------|-------------------------|----------------| +| Function | YUV frame data release | | | | | +| URI | URI Description | | | URI Value | | +| | SDC_URL_YUV_DATA | | | 0x01 | | +| Request | | | | Response | | +| Common header | | Extension header | Content | Extension header | Content | +| Method | DELETE | None | sdc_yuv_data | None | None | + +The YUV frame data release interface definition is illustrated in Table 8-12. + +#### **8.1.6.2 Content definition** + +The definition of sdc\_yuv\_data refer to 8.1.5.2.2. + +#### **8.1.6.3 Extension header** + +None. + +#### **8.1.6.4 Implementation example** + +Refer to the YUV frame data subscription example in clause I.2.3. + +### **8.1.7 VENC logical channel attribute setting** + +#### **8.1.7.1 VENC logical channel attribute setting interface** + +The VENC logical channel attribute setting interface definition is illustrated in Table 8-13. + +**Table 8-13 – VENC logical channel attribute setting interface definition** + +| | | | | | | +|----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------|------------------------|-------------------------|----------------| +| Function | VENC logical channel attribute setting | | | | | +| URI | URI Description | | | URI Value | | +| | SDC_URL_VENC_CHANNEL | | | 2 | | +| Request | | | Response | | | +| Common header | | Extension header | Content | Extension header | Content | +| Method | UPDATE | None | sdv_venc_channel_param | None | None | +| Response code | If the function is normal, response code 200 is returned. If an input error occurs, response code 400 is returned. If a server error occurs, response code 500 is returned. | | | | | + +#### **8.1.7.2 Content definition** + +For the "sdv\_venc\_channel\_param" definition, please see Table 8-14. + +###### **8.1.7.2.1 sdv\_venc\_channel\_param** + +**Table 8-14 – sdv\_venc\_channel\_param** + +| Element name | Type | Description | +|---------------------|-------------|--------------------------------------------------------------------------------------------------------| +| channel | uint32 | The number of the logical channel | +| width | uint32 | Resolution | +| height | uint32 | Resolution | +| fps | uint32 | Frame per second | +| on_off | uint32 | The value 0 indicates that the channel is disabled. Other values indicate that the channel is enabled. | +| format | uint32 | Compression format: H264 / H265 / MJPEG | + +#### **8.1.7.3 Extension header definition** + +None. + +#### **8.1.7.4 Implementation example** + +Refer to clause I.2.4. + +### **8.1.8 VENC logical channel attribute query** + +#### **8.1.8.1 VENC logical channel attribute query interface** + +The VENC logical channel attribute query interface definition is illustrated in Table 8-15. + +**Table 8-15 – VENC logical channel attribute query interface definition** + +| | | | | | | +|----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------|-----------------|-------------------------|----------------| +| Function | VENC logical channel attribute query | | | | | +| URI | URI Description | | | URI Value | | +| | SDC_URL_VENC_CHANNEL | | | 2 | | +| Request | | | Response | | | +| Common header | | Extension header | Content | Extension header | Content | +| Method | GET | None | channel_number | None | None | +| Response code | If the function is normal, response code 200 is returned. If an input error occurs, response code 400 is returned. If a server error occurs, response code 500 is returned. | | | | | + +#### 8.1.8.2 Content definition + +The definition of "channel\_number" refer to clause 8.1.4.2. + +#### 8.1.8.3 Extension header definition + +None. + +#### 8.1.8.4 Implementation example + +Refer to clause I.2.5. + +### 8.1.9 VENC frame data subscription + +#### 8.1.9.1 VENC frame data subscription API + +The VENC frame data subscription interface definition is illustrated in Table 8-16. + +**Table 8-16 – VENC frame data subscription interface definition** + +| | | | | | | +|----------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------|------------------------------------------|---------------------------|----------------| +| Function | VENC frame data subscription | | | | | +| URI | URI Description | | | URI Value | | +| | SDC_URL_VENC_DATA | | | 0x03 | | +| Request | | | Response | | | +| Common header | | Extension header | Content | Extension header | Content | +| Method | GET | Refer to clause 8.1.9.3.1 | channel_number (refer to clause 8.1.4.2) | Refer to clause 8.1.9.3.2 | sdc_venc_data | +| Response Code | If the function is normal, response code 200 is returned. If flow control is enabled, response code 509 (Bandwidth Limit Exceeded) and empty response content are returned. If an input error occurs, response code 400 is returned. If a server error occurs, response code 500 and empty response content are returned. | | | | | + +#### 8.1.9.2 Content definition + +For the definition of "sdc\_venc\_frame", please see Table 8-17. For the definition of "sdc\_venc\_data", please see Table 8-18. + +###### 8.1.9.2.1 sdc\_venc\_frame + +Table 8-17 – sdc\_venc\_frame + +| Element name | Type | Description | +|--------------|--------|----------------------| +| addr_phy | uint32 | Physical address | +| addr_virt | uint32 | Virtual address | +| size | uint32 | The size of frame | +| width | uint32 | Resolution width | +| height | uint32 | Resolution height | +| format | uint32 | SDC_H264 OR SDC_H265 | +| frame_type | uint32 | SDC_VENC_FRAME_I/P/B | + +###### 8.1.9.2.2 sdc\_venc\_data + +Table 8-18 – sdc\_venc\_data + +| Element name | Type | Description | +|--------------|----------------|-----------------------------------| +| channel | uint32 | The number of the logical channel | +| reserve | uint32 | Reserve | +| frame_pts | uint64 | Frame timestamp | +| pts_sys | uint64 | System timestamp | +| frame | sdc_venc_frame | sdc_venc_frame | + +#### 8.1.9.3 Extension header + +###### 8.1.9.3.1 Extension header for request + +SDC\_HEAD\_VENC\_CACHED\_COUNT\_MAX: Extension header for setting the flow control threshold; the format definition is illustrated in Figure 8-7. + +![Diagram of Extension header format for SDC_HEAD_VENC_CACHED_COUNT_MAX. It shows a header structure with two 2-byte fields at the top: 'Extension header type (0x01)' and 'Extension header length (8)'. Below these is a multi-byte 'value (maximum number of video frames that can be cached)' field.](9167fa5ebcb66516d1bbb421ec9bba7b_img.jpg) + +| | | | | +|-----------------------------------------------------------|--|-----------------------------|--| +| 2 bytes | | 2 bytes | | +| Extension header type (0x01) | | Extension header length (8) | | +| value (maximum number of video frames that can be cached) | | | | + +Diagram of Extension header format for SDC\_HEAD\_VENC\_CACHED\_COUNT\_MAX. It shows a header structure with two 2-byte fields at the top: 'Extension header type (0x01)' and 'Extension header length (8)'. Below these is a multi-byte 'value (maximum number of video frames that can be cached)' field. + +F.735.2(21)\_F8-7 + +Figure 8-7 – Extension header: SDC\_HEAD\_VENC\_CACHED\_COUNT\_MAX + +The value is saved in the **Reserve** field in the extension header. If this extension header does not exist, the default number of cached video frames on the server is calculated as follows: Sum of frame rates of each channel x 2. (That is, VENC frame resources are occupied for up to 2s. This number is not related to the size of each frame. The client caches consecutive video frames.) + +If the total number of cached (not released) video frames exceeds the threshold, the server starts the flow control function and does not forward the subscribed video frame data. Therefore, users need to invoke the interface for releasing VENC frames as needed. + +###### 8.1.9.3.2 Extension header for response + +SDC\_HEAD\_VENC\_CACHED\_COUNT: Extension header for counting cached video frames, the format definition is illustrated in Figure 8-8. + +![Diagram of Extension header structure showing two 2-byte fields: Extension header type (0x10) and Extension header length (8), followed by a value field for the maximum number of cached video frames.](7133ccf78043568ca62ecbcd43628a4a_img.jpg) + +| | | | | +|-----------------------------------------------|--|-----------------------------|--| +| 2 bytes | | 2 bytes | | +| Extension header type (0x10) | | Extension header length (8) | | +| value (maximum number of cached video frames) | | | | + +Diagram of Extension header structure showing two 2-byte fields: Extension header type (0x10) and Extension header length (8), followed by a value field for the maximum number of cached video frames. + +F.735.2(21)\_F8-8 + +**Figure 8-8 – Extension header: SDC\_HEAD\_VENC\_CACHED\_COUNT** + +#### **8.1.9.4 Implementation example** + +Refer to clause I.2.6. + +#### **8.1.10 VENC frame data release** + +#### **8.1.10.1 VENC frame data release interface** + +The VENC frame data release interface definition is illustrated in Table 8-19. + +**Table 8-19 – VENC frame data release interface definition** + +| | | | | | | +|----------------------|-------------------------|-------------------------|----------------------------------------------|-------------------------|----------------| +| Function | VENC frame data release | | | | | +| URI | URI Description | | | URI Value | | +| | SDC_URL_VENC_DATA | | | 0x03 | | +| Request | | | Response | | | +| Common header | | Extension header | Content | Extension header | Content | +| Method | DELETE | None | sdc_venc_data
(refer to clause 8.1.9.2.2) | None | None | + +#### **8.1.10.2 Content definition** + +None. + +#### **8.1.10.3 Extension header definition** + +None. + +#### **8.1.10.4 Implementation example** + +For an implementation example of the interface please refer to the VENC frame data subscription interface in clause I.2.6. + +### **8.1.11 Snapshot interface** + +#### **8.1.11.1 Snapshot interface** + +The snapshot interface definition is illustrated in Table 8-20. + +**Table 8-20 – Snapshot interface definition** + +| | | | | | | +|----------------------|-----------------------------------------------------------------------------------------|-------------------------|---------------------|-------------------------|----------------| +| Function | Snapshot interface | | | | | +| URI | URI Description | | | URI Value | | +| | SDC_URL_YUV_SNAP | | | 0x04 | | +| Request | | | Response | | | +| Common header | | Extension header | Content | Extension header | Content | +| Method | CREATE | None | sdcd_yuv_snap_param | None | None | +| Response code | If the function is normal, response code 200 is returned. Other values are error codes. | | | | | + +Snapshot frames are classified into two types: snapshot proactively triggered by external devices and snapshot proactively triggered by the service layer. To obtain the two types of snapshot frame data, the service layer needs to subscribe to data of the snapshot channel. During subscription, you need to set the extension header to obtain the snapshot frame parameters. + +NOTE – The snapshot request must be sent on the handle of the subscribed snapshot channel. Otherwise, the snapshot frame data cannot be received. + +#### **8.1.11.2 Content definition** + +For the definition of "sdcd\_yuv\_snap\_param", please see Table 8-21. + +###### **8.1.11.2.1 sdcd\_yuv\_snap\_param** + +**Table 8-21 – sdcd\_yuv\_snap\_param** + +| Element name | Type | Description | +|---------------------|-------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| id | uint32 | User id. When a user subscribes to snapshot frame data, the user can obtain the corresponding ID for matching. | +| num | uint32 | Number of snapshots | +| frame_pts | uint64 | Frame timestamp | +| interval_msec | uint64 | Snapshot interval, in milliseconds. A maximum of four snapshot intervals can be set. The number of snapshot intervals equals the number of snapshots minus 1. Currently, a maximum of three snapshots are supported. That is, a maximum of two snapshot intervals can be set currently. | +| portaddr_name | char[16] | Port name | + +#### **8.1.11.3 Extension header** + +None. + +#### **8.1.11.4 Implementation example** + +Refer to the YUV frame data subscription example in clause I.2.3. + +## **8.2 Algorithm inference API** + +This clause defines the algorithm inference API based on the neural network inference engine (NNIE) model, NNIE is a widely used acceleration engine in surveillance system Soc. + +### 8.2.1 Model creation + +#### 8.2.1.1 Model creation interface + +This interface is used to create executable models based on the input WK file. The NNIE model creation interface definition is illustrated in Table 8-22. + +**Table 8-22 – Model creation interface definition** + +| | | | | | | +|----------------------|-----------------------------------------------------------------------------------------|-------------------------|-------------------------|-------------------------|----------------| +| Function | NNIE model creation | | | | | +| URL | URI Description | | | URI Value | | +| | SDC_URL_NNIE_MODEL | | | 0 | | +| Request | | | Response | | | +| Common header | | Extension header | Content | Extension header | Content | +| Method | CREATE | Refer to clause 8.2.1.3 | Refer to clause 8.2.1.2 | None | Model | +| Response code | If the function is normal, response code 200 is returned. Other values are error codes. | | | | | + +#### 8.2.1.2 Content definition + +If the extension header SDC\_HEAD\_NNIE\_MODEL\_CONTENT\_TYPE is set to 0 or not defined, the request content is SDCMmz. + +If the extension header SDC\_HEAD\_NNIE\_MODEL\_CONTENT\_TYPE is set to 1, the content specifies the file name in the following format: char filename[].http\_content\_length indicates the length of the file name. Therefore, whether the file name ends with NULL does not affect the function. + +###### 8.2.1.2.1 SDCMmz + +For the definition of "SDCMmz", please see Table 8-23. + +**Table 8-23 – SDCMmz** + +| Element name | Type | Description | +|---------------------|-------------|--------------------------------------| +| addr_phy | uint64 | Physical address | +| addr_virt | uint64 | Virtual address | +| size | uint32 | size | +| cookie | uint32 [4] | Cookie text for the creation session | + +#### 8.2.1.3 Extension header + +###### 8.2.1.3.1 Request extension header (SDC\_HEAD\_DECODED\_YUV\_ACCEPT\_TYPE) + +The extension header definition for request is shown Figure 8-9. If no extension header is defined, the MMZ mode is used. + +![Diagram of Extension header structure showing two 2-byte fields: Extension header type (0x01) and Extension header length (8). Below the length field, it specifies (1: file; 0: MMZ).](8c348bf9c2c81b018017ae1d19506a9a_img.jpg) + +| | | | | +|------------------------------|--|-----------------------------|--| +| 2 bytes | | 2 bytes | | +| Extension header type (0x01) | | Extension header length (8) | | +| (1: file; 0: MMZ) | | | | + +Diagram of Extension header structure showing two 2-byte fields: Extension header type (0x01) and Extension header length (8). Below the length field, it specifies (1: file; 0: MMZ). + +F.735.2(21)\_F8-9 + +**Figure 8-9 – Extension header: SDC\_HEAD\_DECODED\_YUV\_ACCEPT\_TYPE** + +#### 8.2.1.4 Implementation example + +The reference implementation example of interface please refer to clause I.3.1. + +### 8.2.2 Model deletion + +#### 8.2.2.1 Model deletion interface + +This interface is used to release the executable model created based on the WK file. The NNIE model deletion interface definition is illustrated in Table 8-24. + +**Table 8-24 – NNIE model deletion interface definition** + +| | | | | | | +|----------------------|--------------------------------------------------------|-------------------------|------------------|------------------|----------------| +| Function | NNIE model deletion | | | | | +| URL | URI Description | | | URI Value | | +| | SDC_URL_NNIE_MODEL | | | 0 | | +| Request | | | Response | | | +| Common header | | Extension header | Content | | Content | +| Method | DELETE | None | SVP_NNIE_MODEL_S | | None | +| Response code | No response is returned in resource release interfaces | | | | | + +#### 8.2.2.2 Content definition + +The "SVP\_NNIE\_MODEL\_S" is a defined structure type base on NNIE mode engine which is widely used in video surveillance system. The definition of "SVP\_NNIE\_MODEL\_S" is out scope of this Recommendation. + +#### 8.2.2.3 Extension header + +None. + +#### 8.2.2.4 Implementation example + +The implementation example of interface please refer to clause I.3.2. + +### 8.2.3 Model forward + +#### 8.2.3.1 Model forward interface + +This interface is used for multi-node input and output CNN network prediction. The NNIE model forward interface definition is illustrated in Table 8-25. + +NOTE – This interface is equivalent to combining "HI\_MPI\_SVP\_NNIE\_GetTskBufSize", "HI\_MPI\_SVP\_NNIE\_Forward" and "HI\_MPI\_SVP\_NNIE\_Query" interfaces, and the latter is the response, the definition of HI\_MPI\_SVP\_NNIE\_GetTskBufSize, HI\_MPI\_SVP\_NNIE\_Forward and HI\_MPI\_SVP\_NNIE\_Query can refer to the NNIE engine, and is out scope of this Recommendation. + +**Table 8-25 – NNIE forward interface definition** + +| | | | | | | +|----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------|-------------------------|-------------------------|----------------| +| Function | NNIE forward | | | | | +| URL | URI Description | | | URI Value | | +| | SDC_URL_NNIE_FORWARD | | | 1 | | +| Request | | | Response | | | +| Common header | | Extension header | Content | Extension header | Content | +| Method | GET | Refer to clause 8.2.3.3 | Refer to clause 8.2.3.2 | Refer to clause 8.2.3.3 | None | +| Response code | If the operation succeeds, response code 200 is returned. Other values are error codes. If flow control is enabled, response code 509 (Bandwidth Limit Exceeded) and empty response content are returned. | | | | | + +#### 8.2.3.2 Content definition + +For the definition of "sdc\_nnie\_forward\_ctrl", please see Table 8-26. For the definition of "sdc\_nnie\_forward\_para", please see Table 8-27. + +###### 8.2.3.2.1 sdc\_nnie\_forward\_ctrl + +**Table 8-26 – sdc\_nnie\_forward\_ctrl** + +| Element name | Type | Description | +|---------------------|-------------|--------------------| +| netseg_id | uint64 | Physical address | +| max_batch_num | uint64 | Virtual address | +| max_bbox_num | uint32 | size | + +##### 8.2.3.2.2 sdc\_nnie\_forward\_para + +**Table 8-27 – sdc\_nnie\_forward\_para** + +| Element name | Type | Description | +|---------------------|-----------------------|--------------------| +| model | SVP_NNIE_MODEL_S | / | +| forward_ctl | sdc_nnie_forward_ctrl | / | +| astSrc | SVP_SRC_BLOB_S[16] | / | +| astDst | SVP_DST_BLOB_S[16] | / | + +NOTE – The definition of SVP\_NNIE\_MODEL\_S and SVP\_SRC\_BLOB\_S are out scope of this Recommendation. + +#### 8.2.3.3 Extension header + +###### 8.2.3.3.1 Extension header for request + +a) Task Priority (SDC\_HEAD\_PRI), the header definition is shown in Figure 8-10. + +| | | +|----------------------------------------------------------------------------------|--------------------------------| +| Extension header type (0xFFFE) | Extension header length (0x08) | +| Priority (value range: [-127, 127]; A smaller value indicates a higher priority) | | + +F.735.2(21)\_F8-10 + +**Figure 8-10 – Extension header: SDC\_HEAD\_PRI** + +A smaller value indicates a higher priority. The maximum waiting delay (controlled by the server, 300 ms by default) is configured for a low-priority task. If the maximum waiting delay is exceeded, a high-priority task cannot pre-empt resources of the low-priority task. + +##### **8.2.3.4 Implementation example** + +The implementation example, please refer to clause I.3.3. + +# Appendix I + +## Data Type Definition and API Example + +(This appendix does not form an integral part of this Recommendation.) + +## I.1 SOI data type definition example + +### I.1.1 Common header definition + +The common header data structure can be defined as follows based on the endian macro definition of GCC: + +``` +struct sdc_common_head +{ + uint16_t hbtp_ver; + uint8_t uri_ver; + #if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && + defined(__ORDER_BIG_ENDIAN__) + #if (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) + uint8_t method: 7; + uint8_t response: 1; + #elif (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) + uint8_t response: 1; + uint8_t method: 7; + #else + #error "unknown __BYTE_ORDER__" + #endif + #else + #error "don't define __BYTE_ORDER__ or __ORDER_LITTLE_ENDIAN__ or + __ORDER_BIG_ENDIAN__" + #endif + uint16_t uri; + uint16_t code; + uint16_t head_length; + uint16_t trans_id; + uint32_t content_length; +}; + +The response code is valid only when R is set to 1. The following describes +the response codes: +HBTP_CODE_200 = 200, // OK +HBTP_CODE_400 = 400, // Bad Request +HBTP_CODE_401 = 401, // Unauthorized +HBTP_CODE_403 = 403, // Forbidden +HBTP_CODE_404 = 404, // Not Found +HBTP_CODE_500 = 500, // Internal Server Error +HBTP_CODE_509 = 509 and // Flow control +``` + +### I.1.2 Extension header definition + +``` +struct sdc_extend_head +{ + uint16_t hdr_type; + uint16_t hdr_len; + uint32_t reserve; +}; +``` + +## I.2 Video service API example + +### I.2.1 YUV logical channel attribute settings example + +##### Content definition + +``` +#define SDC_YVU_420SP0 // YUV frame. Currently, only YVU_420SP is supported. +struct sdc_yuv_channel_param +{ + uint32_t channel;// The value 0 indicates the snapshot channel (supported only + for the ITS model). + uint32_t width; + uint32_t height; + uint32_t fps; // The value 0 indicates the default frame rate at the + bottom layer. + uint32_t on_off; // The value 0 indicates that the channel is disabled. Other + values indicate that the channel is enabled. + uint32_t format; //SDC_YVU_420SP +}; + +Batch configuration is supported. The number of channels is calculated as +follows: hhttp.content_length/sizeof(sdc_yuv_channel_param). +If the input parameter settings are correct, the settings take effect. Channel +conflicts between services are resolved at the service layer. +``` + +##### Reference example + +``` +#include "sdc.h" +#include +#include +#include +#include +int main(int argc,char* argv[]) +{ + struct sdc_yuv_channel_param param = { + .channel = 1, + .width = 1280, + .height = 720, + .fps = 25, + .on_off = 1, + .format = SDC_YVU_420SP, + }; + struct sdc_common_head head = { + .version = SDC_VERSION, //0x5331 + .url = SDC_URL_YUV_CHANNEL, //0x00 + .method = SDC_METHOD_UPDATE, //0x02 + .content_length = sizeof(param), + .head_length = sizeof(head), + }; + struct iovec iov[2] = { { .iov_base = &head, .iov_len = sizeof(head) }, + { .iov_base = ¶m, .iov_len = sizeof(param) } }; + int nret; + int fd = open("/mnt/srvfs/video.iaas.sdc", O_RDWR); + if(fd < 0) goto fail; + nret = writev(fd, iov, 2); + if(nret < 0) goto fail; + nret = read(fd,&head, sizeof(head)); + if(head.code == SDC_CODE_200 /** 200 **/ ) { + //... + }else{ + //... + } + close(fd); + return 0; +fail: + exit(1); //fd will be closed after exit +} +``` + +### I.2.2 YUV logical channel attribute querying example + +##### Content definition + +``` +uint32_t channel; +/**Attributes of logical channels can be queried in batches. The number of +channels is calculated as follows: hhttp.content_length/sizeof(uint32_t). +If there is no content, that is, the value of hhttp.content_length is 0, the +attributes of all channels are returned.**/ +struct sdc_resolution { + uint32_t width; + uint32_t height; +}; +struct sdc_yuv_channel_info +{ + struct sdc_yuv_channel_param param; + struct sdc_resolution max_resolution; // Maximum resolution supported by the + channel. + uint32_t is_snap_channel; // Indicates whether the channel is a snapshot + channel. The options are as follows: 0: common channel; 1: snapshot channel. + uint32_t src_id; // Data source. The data source uses the IP address + to identify the data source (local camera or other cameras) of the channel. + For the local multi-lens camera, the data source is identified by 127.0.0.x, + where x starts from 1 and is incremented by 1. + uint32_t subscriber_cnt; // Number of users who subscribe to data of this + channel. The value greater than 1 indicates that multiple users subscribe to + data of the same channel. Video data is transferred to users in zero-copy + mode. If a user modifies the data obtained from this channel, other users will + read the data after modification. + uint32_t resolution_modifty; // Indicates whether the resolution parameter + of the channel can be modified. The options are as follows: 0: no; 1: yes. +}; +/**When attributes of logical channels are queried in batches, the response +content is also returned in batches. The number of channels returned in +batches is calculated as follows: hhttp.content_length/sizeof(struct +sdc_yuv_channel_info). +**/ +``` + +##### Reference example + +``` +#include "sdc.h" +#include +#include +#include +static void display_yuv_channel_info(struct sdc_yuv_channel_info* info); +int main(int argc,char* argv[]) +{ + int nret,i; + char buf[1024] = { 0 }; + struct sdc_yuv_channel_info* info; + struct sdc_common_head* head = (struct sdc_common_head*)buf; + /** query all channels' info */ + head->version = SDC_VERSION; //0x5331 + head->url = SDC_URL_YUV_CHANNEL; //0x00 + head->method = SDC_METHOD_GET; //0x02 + head->head_length = sizeof(*head); + int fd = open("/mnt/srvfs/video.iaas.sdc", O_RDONLY); + if(fd < 0) goto fail; + nret = write(fd, head, head->head_length + head->content_length); + if(nret < 0) goto fail; + nret = read(fd,buf,sizeof(buf)); + if(nret < 0 || head->code != SDC_CODE_200) goto fail; + info = (struct sdc_yuv_channel_info*)&buf[head->head_length]; + for(i = 0; i < head->content_length / sizeof(*info); ++i, ++info) { +``` + +``` + +display_yuv_channel_info(info); +} +close(fd); +return 0; +fail: +exit(1); //fd will be closed after exit +} +static void display_yuv_channel_info(struct sdc_yuv_channel_info* info) +{ +} + +``` + +### 1.2.3 YUV frame data subscription example + +##### Content definition + +``` + +uint32_t channel; +Multiple channels can be obtained. The number of channels is calculated as +follows: hhttp.content_length/sizeof(uint32_t). +/**After the subscription is successful, multiple packets are received +consecutively. The first response packet has no content. **/ +/**The subsequent packets include YUV frame data. The structure is defined as +follows: **/ +struct sdc_yuv_frame +{ +uint64_t addr_phy; +uint64_t addr_virt; // Cache mapping is implemented by default. +uint32_t size; +uint32_t width; +uint32_t height; +uint32_t stride; +uint32_t format; +uint32_t reserve; +uint32_t tcookie[4]; // Required by service functions or during commissioning. +} +struct sdc_yuv_data +{ +uint32_t channel; +uint32_t reserve; +uint64_t pts; // Timestamp carried by the bottom-layer chip, in microseconds. +uint64_t pts_sys; // Timestamp of the data obtained by the server, in +microseconds. +struct sdc_yuv_frame frame; +}; +/**When channel data is subscribed in batches, the number of channels is +calculated as follows: hhttp.content_length/sizeof(struct sdc_yuv_data). +The bottom-layer chip time of multi-lens SDCs may be inconsistent. The +synchronization of multiple channels depends on the system time, that is, the +pts_sys field rather than the pts field. +Note: The trans_id field in the response headers of multiple packets is the +same as the trans_id field in the subscription request.**/ + +``` + +##### Reference example + +``` + +#include "sdc.h" +#include +#include +#include +static void display_extend_head(struct sdc_extend_head* extend_head) {} +static void display_yuv_data(struct sdc_yuv_data* yuv_data) {} +int main(int argc,char* argv[]) +{ +int nret,i,fd; +char buf[1024] = { 0 }; +struct sdc_common_head* head = (struct sdc_common_head*) buf; +struct sdc_extend_head* extend_head; + +``` + +``` + +struct sdc_yuv_data* yuv_data; +struct sdc_yuv_snap_param* snap_param; +uint32_t* channel; +fd = open("/mnt/srvfs/video.iaas.sdc", O_RDONLY); +if(fd < 0) goto fail; +head->version = SDC_VERSION; +head->url = SDC_URL_YUV_DATA; +head->method = SDC_METHOD_GET; +head->head_length = sizeof(*head); +/** The maximum number of cached YUV frames is 10. */ +extend_head = (struct sdc_extend_head*)&buf[head->head_length]; +extend_head->type = SDC_HEAD_YUV_CACHED_COUNT_MAX; +extend_head->length = sizeof(*extend_head); +extend_head->reserve = 10; +/** + * #define sdc_extend_head_length(extend_head) (((extend_head)->length + 7) & + * ~7) + * The length of the extension header defined in the existing SDC service- + * oriented interface is aligned by 8 bytes. Developers also need to write "head- + * >head_length += extend_head->length" to ensure that the length of the + * extension header is 8-byte aligned. + */ +head->head_length += sdc_extend_head_length(extend_head); +/** Subscribe to data of two channels. No synchronization is required because + * one channel is the snapshot channel. */ +extend_head = (struct sdc_extend_head*)&buf[head->head_length]; +extend_head->type = SDC_HEAD_YUV_SYNC; +extend_head->length = sizeof(*extend_head); +extend_head->reserve = 0; +head->head_length += sdc_extend_head_length(extend_head); +/** Subscribe to data of two channels. */ +channel = (uint32_t*)&buf[head->head_length]; +channel[0] = 0; // The value 0 indicates the snapshot channel by default. The +snapshot channel ID can be obtained through the query interface. +channel[1] = 1; +head->content_length = 2 * sizeof(channel[0]); +nret = write(fd, head, head->head_length + head->content_length); +if(nret < 0) goto fail; +for(;;) { +nret = read(fd, buf, sizeof(buf)); +if(nret < 0) goto fail; +switch(head->url){ +case SDC_URL_YUV_SNAP: +/** Response to snapshot processing. */ +if(head->code != SDC_CODE_200) { +// log error info +} +continue; +case SDC_URL_YUV_DATA: +break; +default: +continue; +} +/** + * #define sdc_extend_head_next(extend_head) ((struct + * sdc_extend_head*)((char*)extend_head + sdc_extend_head_length(extend_head))) + * #define sdc_extend_head_first(common_head) ((struct + * sdc_extend_head*)(common_head + 1)) + * #define sdc_for_each_extend_head(common_head, extend_head) \ + * for( extend_head = sdc_extend_head_first(common_head); (char*)extend_head - + * (char*)common_head < common_head->head_length; extend_head = + * sdc_extend_head_next(extend_head) ) + */ +sdc_for_each_extend_head(head, extend_head) { + +``` + +``` + +display_extend_head(extend_head); +} +for(i = 0, yuv_data = (struct sdc_yuv_data*)&buf[head->head_length]; i < head->content_length / sizeof(*yuv_data); ++i, ++yuv_data) { +display_yuv_data(yuv_data); +} +/** free yuv_data */ +head->response = head->code = 0; +head->method = SDC_METHOD_DELETE; +(void)write(fd,head,head->head_length + head->content_length); // server +ignore extended headers +/** Trigger the snapshot taking action. */ +if( 1 ) { +head->url = SDC_URL_YUV_SNAP; +head->method = SDC_METHOD_CREATE; +head->head_length = sizeof(*head); +head->content_length = sizeof(*snap_param); +snap_param = (struct sdc_yuv_snap_param*)&buf[head->head_length]; +snap_param->id = 100; +snap_param->num = 1; +snap_param->interval_msec = 0; +nret = write(fd, head, head->head_length + head->content_length); +if(nret < 0) goto fail; +/** Data read immediately may not be the snapshot response data. */ +} +} +return 0; +fail: +exit(1); +} + +``` + +### I.2.4 VENC logical channel attribute setting example + +#### Content definition + +``` + +#define SDC_H264 0 +#define SDC_H265 1 +#define SDC_MJPEG 2 +struct sdc_venc_channel_param +{ +uint32_t channel; +uint32_t width; +uint32_t height; +uint32_t fps; // The value ranges from 1 to the value of MaxFps. +uint32_t on_off; // The value 0 indicates that the channel is disabled. Other +values indicate that the channel is enabled. +uint32_t format; // SDC_H264 \ SDC_H265 \ SDC_MJPEG +}; +/**Batch configuration is supported. The number of channels is calculated as +follows: hhttp.content_length/sizeof(sdc_venc_channel_param) . +If the input parameter settings are correct, the settings take effect. Channel +conflicts between services are resolved at the service layer.**/ + +``` + +#### Reference example + +``` + +#include "sdh.h" +#include +#include +#include +#include +int main(int argc,char* argv[]) +{ +struct sdc_yuv_channel_param param = { +.channel = 100, + +``` + +``` + +.width = 1280, +.height = 720, +.fps = 25, +.on_off = 1, +.format = SDC_H264, +}; +struct sdc_common_head head = { +.version = SDC_VERSION, //0x5331 +.url = SDC_URL_VENC_CHANNEL, //0x02 +.method = SDC_METHOD_UPDATE, //0x02 +.content_length = sizeof(param), +.head_length = sizeof(head), +}; +struct iovec iov[2] = { { .iov_base = &head, .iov_len = sizeof(head) }, +{ .iov_base = ¶m, .iov_len = sizeof(param) } }; +int nret; +int fd = open("/mnt/srvfs/video.iaas.sdc", O_RDWR); +if(fd < 0) goto fail; +nret = writev(fd, iov, 2); +if(nret < 0) goto fail; +nret = read(fd,&head, sizeof(head)); +if(head.code == SDC_CODE_200 /** 200 **/ ) { +//... +}else{ +//... +} +close(fd); +return 0; +fail: +exit(1); //fd will be closed after exit +} + +``` + +### I.2.5 VENC logical channel attribute querying example + +#### Content definition + +``` + +uint32_t channel; +/**Attributes of logical channels can be queried in batches. The number of +channels is calculated as follows: hbtp.content_length/sizeof(uint32_t). +If there is no content, that is, the value of hbtp.content_length is 0, the +attributes of all channels are returned.**/ +struct sdc_resolution { +uint32_t width; +uint32_t height; +}; +#define SDC_PT_H264 96 +#define SDC_PT_H265 265 +#define SDC_PT_MJPEG 1002 +struct sdc_venc_channel_ability { +uint32_t max_fps; // Maximum frame rate supported by the channel. +uint32_t format[3]; // Encoding format supported by the channel. The value can +be 96 (H.264), 265 (H.265), or 1002 (MJPEG). +uint32_t resolution_num; // Number of resolution types supported by the +channel. +struct sdc_resolution chn_resolution[0]; // All resolution types supported by +the channel. +}; +struct sdc_venc_channel_info +{ +struct sdc_venc_channel_param param; +uint32_t src_id; // Data source. The data source uses the IP address +to identify the data source (local camera or other cameras) of the channel. +For the local multi-lens camera, the data source is identified by 127.0.0.x, +where x starts from 1 and is incremented by 1. + +``` + +``` + +uint32_t subscriber_cnt; // Number of users who subscribe to data of this +channel. The value greater than 1 indicates that multiple users subscribe to +data of the same channel. Video data is transferred to users in zero-copy +mode. If a user modifies the data obtained from this channel, other users will +read the data after modification. +struct sdc_venc_channel_ability stchnability; // Information about the +encoding capability supported by the channel. +}; +/**When attributes of logical channels are queried in batches, the response +content is also returned in batches. The number of channels returned in +batches is calculated as follows: http.content_length/sizeof(struct +sdv_venc_channel_info).**/ + +``` + +#### Reference example + +``` + +#include "sdv.h" +#include +#include +#include +int main(int argc,char* argv[]) +{ +int nret,i; +char buf[1024] = { 0 }; +struct sdc_venc_channel_info* info; +struct sdc_common_head* head = (struct sdc_common_head*)buf; +/** query all channels' info */ +head->version = SDC_VERSION; //0x5331 +head->url = SDC_URL_VENC_CHANNEL; //0x02 +head->method = SDC_METHOD_GET; //0x02 +head->head_length = sizeof(*head); +int fd = open("/mnt/srvfs/video.iaas.sdc", O_RDONLY); +if(fd < 0) goto fail; +nret = write(fd, head, head->head_length + head->content_length); +if(nret < 0) goto fail; +nret = read(fd,buf,sizeof(buf)); +if(nret < 0 || head->code != SDC_CODE_200) goto fail; +/** deal with all channels' info */ +close(fd); +return 0; +fail: +exit(1); //fd will be closed after exit +} + +``` + +### I.2.6 VENC frame data subscription example + +#### Content definition + +``` + +uint32_t channel; +/**Multiple channels can be obtained. The number of channels is calculated as +follows: http.content_length/sizeof(uint32_t). +After the subscription is successful, multiple packets are received +consecutively. The first response packet has no content. +The subsequent packets include VENC frame data. The structure is defined as +follows:**/ +#define SDC_VENC_FRAME_I 0 +#define SDC_VENC_FRAME_P 1 +#define SDC_VENC_FRAME_B 2 +struct sdc_venc_frame +{ +uint64_t addr_phy; +uint64_t addr_virt; // Read-only. +uint64_t size; +uint32_t height; +uint32_t width; +} + +``` + +``` + +uint32_t format; //SDC_H264 OR SDC_H265 +uint32_t frame_type; //SDC_VENC_FRAME_I/P/B +uint64_t tcookie[8]; // Used for commissioning on the server. +} +struct sdc_venc_data +{ + uint32_t channel; + uint32_t reserve; + uint64_t frame_pts; // Frame timestamp. + uint64_t pts_sys; // System timestamp. + struct sdc_venc_frame frame; +}; +/**When channel data is subscribed in batches, the number of channels is +calculated as follows: http.content_length/sizeof(struct sdc_venc_data). +Note: The trans_id field in the response headers of multiple packets is the +same as the trans_id field in the subscription request.**/ + +``` + +#### Reference Example + +``` + +#include "sdc.h" +#include +#include +#include +static void display_extend_head(struct sdc_extend_head* extend_head) {} +static void display_venc_data(struct sdc_venc_data* venc_data) {} +int main(int argc,char* argv[]) +{ + int nret,i,fd; + char buf[1024] = { 0 }; + struct sdc_common_head* head = (struct sdc_common_head*) buf; + struct sdc_extend_head* extend_head; + struct sdc_venc_data* venc_data; + uint32_t* channel; + fd = open("/mnt/srvfs/video.iaas.sdc", O_RDWR); + if(fd < 0) goto fail; + head->version = SDC_VERSION; + head->url = SDC_URL_VENC_DATA; + head->method = SDC_METHOD_GET; + head->head_length = sizeof(*head); + /** The maximum number of cached VENC frames is 10. */ + extend_head = (struct sdc_extend_head*)&buf[head->head_length]; + extend_head->type = SDC_HEAD_VENC_CACHED_COUNT_MAX; + extend_head->length = sizeof(*extend_head); + extend_head->reserve = 10; + head->head_length += sdc_extend_head_length(extend_head); + /** Subscribe to data of channel 0. */ + channel = (uint32_t*)&buf[head->head_length]; + *channel = 0; + head->content_length = sizeof(*channel); + nret = write(fd, head, head->head_length + head->content_length); + if(nret < 0) goto fail; + for(;;) { + nret = read(fd, buf,sizeof(buf)); + if(nret < 0) goto fail; + sdc_for_each_extend_head(head, extend_head) { + display_extend_head(extend_head); + } + for(i = 0, venc_data = (struct sdc_venc_data*)&buf[head->head_length]; i < + head->content_length / sizeof(*venc_data); ++i, ++venc_data) { + display_venc_data(venc_data); + } + /** free venc_data */ + head->response = head->code = 0; + } +} + +``` + +``` + +head->method = SDC_METHOD_DELETE; +(void)write(fd,head,head->head_length + head->content_length); // server +ignore extended headers +} +return 0; +fail: +exit(1); +} + +``` + +## I.3 Algorithm inference example + +### I.3.1 Model creation example + +##### Content definition Example + +If no extension header is defined, the MMZ mode is used. +#define NNIE\_MODEL\_CONTENT\_MMZ 0 +#define NNIE\_MODEL\_CONTENT\_FILE 1 +If the extension header **SDC\_HEAD\_NNIE\_MODEL\_CONTENT\_TYPE** is set to **0** or not defined, the content specifies the MMZ in the following format: struct sdc\_mmz. +If the extension header **SDC\_HEAD\_NNIE\_MODEL\_CONTENT\_TYPE** is set to **1**, the content specifies the file name in the following format: char filename[]. http.content\_length indicates the length of the file name. Therefore, whether the file name ends with **NULL** does not affect the function. + +##### Reference Example + +``` + +int SDC_LoadModel(unsigned int uiLoadMode, char *pucModelFileName, +SVP_NNIE_MODEL_S *pstModel) +{ +int s32Ret = 0; +int ret = 0; +int u32TotalSize = 0; +struct sdc_extend_head* extend_head; +char buf[1024] = {0}; +struct sdc_common_head *phead = (struct sdc_common_head *)buf; +unsigned int uFileSize; +struct sdc_mmz stMmzAddr; +if ((NULL == pstModel) || (NULL == pucModelFileName)) +{ +fprintf(stderr,"Err in SDC_LoadModel, pstModel or pucModelFileName is +null\n"); +return -1; +} +fprintf(stderr,"Load model, pucModelFileName:%s!\n", pucModelFileName); +struct sdc_common_head head; +struct rsp_struct { +struct sdc_common_head head; +SVP_NNIE_MODEL_S model; +}rsp_struct_tmp; +struct iovec iov[2] = { +[0] = { .iov_base = buf, .iov_len = sizeof(struct sdc_common_head) + +sizeof(struct sdc_extend_head) }, +[1] = { .iov_len = MAX_MODULE_PATH } +}; +//memset(&head, 0, sizeof(head)); +phead->version = SDC_VERSION; +phead->url = SDC_URL_NNIE_MODEL; +phead->method = SDC_METHOD_CREATE; +phead->head_length = sizeof(struct sdc_common_head); +phead->content_length = MAX_MODULE_PATH; + +``` + +``` + +/* If the mode is 0 and no extension header is carried, load the model from +the MMZ by default. */ +if (uiLoadMode == 0) +{ +FILE *fp = fopen(pucModelFileName, "rb"); +if(fp == NULL) +{ +fprintf(stdout,"modelfile fopen %s fail!\n", pucModelFileName); +return -1; +} +ret = fseek(fp,0L,SEEK_END); +if(ret != 0) +{ +fprintf(stdout,"check nnie file SEEK_END, fseek fail."); +fclose(fp); +return -1; +} +uFileSize = ftell(fp); +ret = fseek(fp,0L,SEEK_SET); +if(0 != ret) +{ +fprintf(stdout,"check nnie file SEEK_SET, fseek fail."); +fclose(fp); +return -1; +} +stMmzAddr.size = uFileSize; +ret = SDC_MmzAlloc(uFileSize, 0, &stMmzAddr); // param 2: 0 no cache, 1 cache +if(ret != stMmzAddr.size) +{ +fprintf(stdout,"SDC_MmzAlloc ret %d, readsize %d", ret, stMmzAddr.size); +return -1; +} +ret = fread((HI_VOID*)(uintptr_t)stMmzAddr.addr_virt, 1, stMmzAddr.size, fp); +if(ret != stMmzAddr.size) +{ +fprintf(stdout,"filesize %d, readsize %d", ret, stMmzAddr.size); +return -1; +} +/* Invoke the algorithm program to decode the input file. */ +if(SDC_ModelDecrypt(&stMmzAddr)) +{ +fprintf(stdout,"SDC_ModelDecrypt Fail!",); +return -1; +} +iov[1].iov_base = &stMmzAddr; +iov[0].iov_len = sizeof(struct sdc_common_head); +} +else if (uiLoadMode == 1)/* If the mode is 1 and an extension header is +carried, specify the extension header parameter to load the model from the +MMZ. */ +{ +FILE *fp = fopen(pucModelFileName, "rb"); +if(fp == NULL) +{ +fprintf(stdout,"modelfile fopen %s fail!\n", pucModelFileName); +return -1; +} +ret = fseek(fp,0L,SEEK_END); +if(ret != 0) +{ +fprintf(stdout,"check nnie file SEEK_END, fseek fail."); +fclose(fp); +return -1; +} +} + +``` + +``` + +uFileSize = ftell(fp); +ret = fseek(fp,0L,SEEK_SET); +if(0 != ret) +{ +printf(stdout,"check nnie file SEEK_SET, fseek fail."); +fclose(fp); +return -1; +} +stMmzAddr.size = uFileSize; +ret = SDC_MmzAlloc(uFileSize, 0, &stMmzAddr); // param 2: 0 no cache, 1 cache +if(ret != stMmzAddr.size) +{ +printf(stdout,"SDC_MmzAlloc ret %d, readsize %d", ret, stMmzAddr.size); +return -1; +} +ret = fread((HI_VOID*)(uintptr_t)stMmzAddr.addr_virt, 1, stMmzAddr.size, fp); +if(ret != stMmzAddr.size) +{ +printf(stdout,"filesize %d, readsize %d", ret, stMmzAddr.size); +return -1; +} +/* Invoke the algorithm program to decode the input file. */ +if(SDC_ModelDecrypt(&stMmzAddr)) +{ +printf(stdout,"SDC_ModelDecrypt Fail!",); +return -1; +} +extend_head = (struct sdc_extend_head*)&buf[phead->head_length]; +extend_head->type = 1;//NNIE_NNIE_MODEL_OP +extend_head->length = sizeof(*extend_head); +extend_head->reserve = 0;/* If this field is set to 0 or not carried, the +model is loaded from the memory. If this field is set to 1, the model is +loaded from a specified file. */ +phead->head_length += sizeof(struct sdc_extend_head); +iov[1].iov_base = &stMmzAddr; +} +else /* If the mode is 2 and an extension header is carried, specify the +extension header parameter to load the model from a specified file. */ +{ +extend_head = (struct sdc_extend_head*)&buf[phead->head_length]; +extend_head->type = 1;//NNIE_NNIE_MODEL_OP +extend_head->length = sizeof(*extend_head); +extend_head->reserve = 1;/* If this field is set to 0 or not carried, the +model is loaded from the memory. If this field is set to 1, the model is +loaded from a specified file. */ +phead->head_length += sizeof(struct sdc_extend_head); +iov[1].iov_base = pucModelFileName;//pcModelName; +} +s32Ret = writev(fd_algorithm, iov, 2); +if (s32Ret < 0) +{ +printf(stdout,"creat nnie,write to algorithm.iaas.sdc fail: %m\n"); +} +/* After loading the model, release it immediately. */ +if (uiLoadMode < 2)mmz_free(fd_config, &stMmzAddr); +s32Ret = read(fd_algorithm, &rsp_struct_tmp, sizeof(rsp_struct_tmp)); +if(s32Ret == -1) +{ +printf(stdout,"get_channel_data fail: %m\n"); +return -1; +} +if(s32Ret > sizeof(rsp_struct_tmp)) +{ +} + +``` + +``` + +fprintf(stdout,"get_channel_data truncated, data len: %d > %zu\n", s32Ret, +sizeof(rsp_struct_tmp)); +return -1; +} +if (s32Ret < 0 || rsp_struct_tmp.head.code != SDC_CODE_200 || +rsp_struct_tmp.head.content_length <= 0) +{ +fprintf(stdout,"get nnie create response, read from algorithm.iaas.sdc +fail,s32Ret:%ld, code=%d,length=%d\n", +s32Ret, rsp_struct_tmp.head.code, rsp_struct_tmp.head.content_length); +} +else +{ +s_stSsdModel.stModel = rsp_struct_tmp.model; +memcpy(pstModel, &rsp_struct_tmp.model,sizeof(SVP_NNIE_MODEL_S)); +} +return s32Ret; +} + +``` + +### I.3.2 Model deletion example + +``` + +int SDC_UnloadModel(SVP_NNIE_MODEL_S *pstModel) +{ +int nRet = -1; +if (NULL != pstModel) +{ +struct sdc_common_head head; +struct iovec iov[2] = { +[0] = {.iov_base = &head , .iov_len = sizeof(head)}, +[1] = {.iov_base = pstModel, .iov_len = sizeof(SVP_NNIE_MODEL_S)} +}; +// fill head struct +memset(&head, 0, sizeof(head)); +head.version = SDC_VERSION; +head.url = SDC_URL_NNIE_MODEL; +head.method = SDC_METHOD_DELETE; +head.head_length = sizeof(head); +head.content_length = sizeof(SVP_NNIE_MODEL_S); +nRet = writev(fd_algorithm, iov, sizeof(iov)/sizeof(iov[0])); +if (nRet < 0) +{ +fprintf(stdout,"Errin SDC_UnloadModel:failed to unload nnie module!\n"); +} +} +else +{ +fprintf(stdout,"Err in SDC_UnloadModel:module pointer is NULL!\n"); +} +return 0; +} + +``` + +### I.3.3 Model forward example + +``` + +/** + * Compared with SVN_NNIE_FORWARD_CTRL_S, this interface has the following +advantages: + * 1. Users do not need to manage auxiliary memory segments, which simplifies +interface use. + * 2. Users do not need to specify NNIE_ID, which is scheduled by the server, +avoiding resource conflicts when multiple models are executed. + * 3. Multiple models share auxiliary memory segments to minimize memory +resource requirements. + */ +struct sdc_nnie_forward_ctrl +{ + +``` + +``` + +uint32_t netseg_id; +uint32_t max_batch_num; +uint32_t max_bbox_num; +uint32_t reserve; +}; +struct { + SVP_NNIE_MODEL_S model; + struct sdc_nnie_forward_ctrl foward_ctl; + SVP_SRC_BLOB_S astSrc[16]; + SVP_DST_BLOB_S astDst[16]; +}; + +void SDC_Nnie_Forward(struct sdc_nnie_forward *p_sdc_nnie_forward) +{ + int nRet; + struct sdc_common_head rsp_head; + struct sdc_common_head head; + struct iovec iov[2] = { + [0] = {.iov_base = &head, .iov_len = sizeof(head)}, + [1] = {.iov_base = p_sdc_nnie_forward, .iov_len = sizeof(*p_sdc_nnie_forward)} + }; + // fill head struct + memset(&head, 0, sizeof(head)); + head.version = SDC_VERSION; + head.url = SDC_URL_NNIE_FORWARD; + head.method = SDC_METHOD_GET; + head.head_length = sizeof(head); + head.content_length = sizeof(*p_sdc_nnie_forward); + // write request + nRet = writev(fd_algorithm, iov, sizeof(iov)/sizeof(iov[0])); + if (nRet < 0) + { + fprintf(stderr, "Error:failed to write info to NNIE Forward!\n"); + } + // read response + iov[0].iov_base = &rsp_head; + iov[0].iov_len = sizeof(rsp_head); + nRet = readv(fd_algorithm, iov, 1); + if (rsp_head.code != SDC_CODE_200 || nRet < 0) + { + fprintf(stderr, "Error:failed to read info from NNIE Forward!\n"); + } +} + +``` + +# Bibliography + +- [b-ITU-T H.264] Recommendation ITU-T H.264 (2019), *Advanced video coding for generic audiovisual services*. +- [b-ITU-T H.626] Recommendation ITU-T H.626 (2019), *Architectural requirements for video surveillance system*. +- [b-ITU-T H.627] Recommendation ITU-T H.627 (2020), *Signalling and protocols for a video surveillance system*. + + + + + + + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.74-199208-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.74-199208-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 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+STANDARDIZATION SECTOR +OF ITU + +**F.740.2** + +(06/2021) + +SERIES F: NON-TELEPHONE TELECOMMUNICATION +SERVICES + +Multimedia services + +--- + +**Requirements and reference framework for +digital representation of cultural relics and +artworks using augmented reality** + +Recommendation ITU-T F.740.2 + +ITU-T + +![ITU logo](1d7527f4316cfe2d342b08d1653d1592_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with white lines representing latitude and longitude, and the letters 'ITU' in a bold, blue, sans-serif font superimposed on the globe. + +ITU logo + +# ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multdestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| MULTIMEDIA SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.740.2 + +# Requirements and reference framework for digital representation of cultural relics and artworks using augmented reality + +## Summary + +Recommendation ITU-T F.740.2 describes the requirements, application scenarios and reference framework for the digital representation of cultural relics and artworks using augmented reality (AR), which is known as an augmented reality cultural service system (ARCSS). This Recommendation describes the AR digital presentation requirements, cultural connotation interpretation requirements, cultural venue tour guide requirements, platform management requirements and performance requirements for ARCSSs. This Recommendation describes a reference framework of an ARCSS with an AR cloud creation platform, AR cloud management platform and mobile devices. Procedures of augmented reality cultural service are provided in this Recommendation including an AR content creation procedure, AR service management procedure and AR content display procedure. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.740.2 | 2021-06-13 | 16 | 11.1002/1000/14679 | + +### Keywords + +Artworks, augmented reality, cultural relics, cultural venue. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2021 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +###### Page + +| | | | +|------|---------------------------------------------------------------------|---| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| 3.1 | Terms defined elsewhere ..... | 1 | +| 3.2 | Terms defined in this Recommendation..... | 1 | +| 4 | Abbreviations and acronyms ..... | 1 | +| 5 | Conventions ..... | 2 | +| 6 | Background..... | 2 | +| 6.1 | The need for cultural communication through augmented reality ..... | 2 | +| 6.2 | The need for cultural appreciation through augmented reality ..... | 2 | +| 6.3 | Technical support and standardization requirements of ARCSSs..... | 2 | +| 7 | Overview of ARCSSs ..... | 3 | +| 8 | Requirements for an ARCSS ..... | 3 | +| 8.1 | AR digital presentation requirements ..... | 3 | +| 8.2 | Cultural connotation interpretation requirements..... | 3 | +| 8.3 | Cultural venue tour guide requirements ..... | 3 | +| 8.4 | ARCSS platform management requirements ..... | 3 | +| 8.5 | ARCSS performance requirements ..... | 4 | +| 9 | ARCSS reference framework ..... | 4 | +| 9.1 | AR cloud creation platform ..... | 4 | +| 9.2 | AR cloud management platform ..... | 4 | +| 9.3 | Mobile devices..... | 5 | +| 10 | Procedures of augmented reality cultural service..... | 5 | +| 10.1 | AR content creation procedure ..... | 5 | +| 10.2 | AR service management procedure ..... | 6 | +| 10.3 | AR content display procedure ..... | 7 | +| | Bibliography..... | 8 | + + + +# Recommendation ITU-T F.740.2 + +## Requirements and reference framework for digital representation of cultural relics/artworks using augmented reality + +## 1 Scope + +This Recommendation describes the requirements and reference framework for the digital representation of cultural relics and artworks using augmented reality (AR). + +The scope of this Recommendation includes: + +- 1) Requirements for an AR cultural service system. +- 2) Reference framework of an AR cultural service system. +- 3) Procedures of an AR cultural service. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following term defined elsewhere: + +**3.1.1 augmented reality** [b-ITU-T J.301]: A type of mixed reality where graphical elements are integrated into the real world in order to enhance user experience and enrich information. + +### 3.2 Terms defined in this Recommendation + +This Recommendation defines the following term. + +**3.2.1 cultural venue**: A public venue generally established and operated by relevant government departments or enterprises to meet the spiritual and cultural needs of the public and carry out public cultural and artistic activities. It basically functions as a place to hold exhibitions, lectures and training, spread scientific and cultural knowledge, carry out social, cultural and art education, collect, sort out and study intangible cultural heritage and conduct relevant general surveys, displays and publicities, etc. Museums, art galleries and community cultural centres are all typical cultural venues. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-------|-------------------------------------------| +| AR | Augmented Reality | +| ARCC | Augmented Reality Content Creator | +| ARCSS | Augmented Reality Cultural Service System | + +## 5 Conventions + +In this Recommendation: + +- The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +## 6 Background + +As a new and emerging media technology, augmented reality (AR) can seamlessly integrate digital virtual content into real scenes and present them on mobile devices when people visit cultural venues. The combination of technology and art will bring new and interactive experiences to the audience and bring the cultural relics and artworks to life. An artistic landscape painting may be quietly hung on the wall, but through the means of AR, it becomes a flowing landscape painting in the visitor's palm (on a mobile device screen). It is like a living scene. In fact, many cultural relics and artworks have historical, social and even political values. Behind them are usually rich cultures and legends which are less known by most of the audience. Without preparation before a visit, visitors at cultural venues often miss some wonderful exhibits and may feel regret when being told of them by others, a common experience for visitors. + +### 6.1 The need for cultural communication through augmented reality + +The visual value of cultural relics and artworks can be demonstrated through physical display, but this has neither dynamic effect nor sound. In the absence of explanation, the appreciation effect depends mainly on audience level and imagination. Many visitors often feel bored and unable to understand. In fact, many cultural relics and artworks transmit historical, social and even political values. Behind them are often rich cultures and legends. If we can use technologies to present the stories behind the cultural relics and artworks in a dynamic way, the audience would be able to establish a link between real objects and abstract conceptions and truly understand them. This is very significant for the dissemination of culture and art. + +### 6.2 The need for cultural appreciation through augmented reality + +Cultural venues are important places for people to receive cultural influences, and an augmented reality cultural service system (ARCSS) has become a relaxing way to experience cultural venues for them. For example, conveniently, some palm gallery apps have been introduced to help visitors understand stories behind exhibits at any time and place. But due to the lack of on-the-spot experience, there is also a lack of fun and interaction, and it is difficult to inspire the enthusiasm of visitors. + +New media practitioners are increasingly applying AR to cultural venues for better results. This Recommendation supports the integration of culture with new media technologies. + +### 6.3 Technical support and standardization requirements of ARCSSs + +This Recommendation introduces scenarios of cultural relics and artworks, and then analyses the requirements for the digital representation of cultural relics and artworks. Extracting analysis and analysing and exploring demands from the scenarios are very meaningful. In cultural venues, the demand for representation, especially digital representation of cultural relics and artworks, requires us to satisfy the protection of cultural relics while taking full advantage of digital representation. + +Further, this Recommendation proposes a reference framework for the digital representation of cultural relics and artworks based on AR. It is the top-level design of the entire system. If it is absent or vaguely defined, there would be differences in the understanding between different departments of + +the industry chain, making technical solutions very different and coordination and cooperation with each other difficult. + +Mobile terminals based on AR digital representation of cultural relics and artworks undertake important tasks for direct interaction with users. If there is no strict quality requirement, they could not only make cultural relics/artworks appear less appealing but even have the opposite effect to that which they set out to deliver. + +## **7 Overview of ARCSSs** + +An ARCSS is a service system of cultural venues such as museums or art galleries for audiences, which exhibits and explains additional information on cultural relics and artworks using AR technology. A software is pre-installed on terminal devices including dedicated devices, mobile phones, tablet computers and AR glasses, which superimposes the digital content (such as voices, graphics and videos) on top of a view of the cultural relics and artworks in real time after identifying the cultural object. The corresponding digital content can be stored locally or in the cloud. A unified standard ARCSS can share data and provide unified global services, and using it audiences will feel welcomed and interested. + +In an ARCSS, there are four kinds of roles, respectively the cultural venue manager (CVM) role, the platform manager role, the AR content creator (ARCC) role and the AR content user (ARCU) role (i.e., visitor). The cultural venue manager needs to submit the basic information and materials of the AR collection to the ARCSS. The ARCC uses the AR cloud creation platform provided by the ARCSS to create AR content. The platform manager is responsible for the operation and maintenance of the ARCSS, including venue management, AR content management and terminal device management, etc. The ARCU receives AR interpretation services through the terminal device linked to the ARCSS in cultural venues. + +## **8 Requirements for an ARCSS** + +The Requirements for an ARCSS include but are not limited to the following. + +### **8.1 AR digital presentation requirements** + +It is recommended that an ARCSS use AR technology including video, sound and other rich media to present stories in a dynamic way, which can enable the audience to feel welcomed, interested and not bored by mobilizing their senses of sight, hearing and touch. + +### **8.2 Cultural connotation interpretation requirements** + +It is recommended that an ARCSS tell the story behind cultural relics and artworks. The world of virtual and realistic synthesis brings people into the realm of fantasy. Through time and space, enabling the audience to appreciate and listen to stories behind cultural relics and artworks gives the audience not only a deep understanding of the art itself, but also a deeper understanding of the artist's ideological realm. + +### **8.3 Cultural venue tour guide requirements** + +It is recommended that an ARCSS provide a portable art assistant functionality, and that the navigation system remind people not to miss a classic when they pass by. + +### **8.4 ARCSS platform management requirements** + +An ARCSS platform runs on the cloud or local server, connects with platform users and terminal devices through a wireless network, receives, stores and distributes AR content, and supports system operation. It is recommended that an ARCSS support user management, venue management, AR content management, terminal device management and other functions. + +### 8.5 ARCSS performance requirements + +It is recommended that an ARCSS provide visitors with high-quality AR interpretation services, and that the management platform support a large number of terminal device concurrent service requests, venue service statistics and hotspot analysis. It is recommended that the terminal device support the smooth playback of AR content, sensitive interactive operation, and battery life to support the general visiting process. It is recommended that AR content support image, text, voice, video, 3D model and other multimodal media forms, with moderate duration and accurate content. + +## 9 ARCSS reference framework + +Based on the requirements and model analysis, the reference framework for the digital representation of cultural relics and artworks using AR is shown in Figure 9-1. + +![Figure 9-1 – Reference framework of ARCSS. The diagram illustrates the interaction between the AR cloud creator, AR cloud management platform (Server), and Mobile device (Client).](daa4a6fa7e2ba1954258f86b4928eb32_img.jpg) + +The diagram illustrates the reference framework of ARCSS, showing the interaction between three main components: AR cloud creator, AR cloud management platform (Server), and Mobile device (Client). + +- AR cloud creator:** Contains Login interface, Project management, and Content-made tools (Identif. and Present.). It interacts with AR material (Import/Export), AR files, and Content creators (Share). It sends User Info. and User mgmt. to the server, and Content and Evaluation to the server. +- AR cloud management platform (Server):** Contains User/device management, Content management (Storage, Resource, and Runtime), and Support algorithm library (Cloud identify). It receives User Info. and User mgmt. from the creator, and Content and Evaluation from the creator. It sends Device info. to the client, and Release resources, Identif., and Present. to the client. It is managed by a Manager and connected to an App store. +- Mobile device (Client):** Contains Perceived devices, Local identif. lib, and Display and interactive devices. It receives Device info. from the server, and Release resources, Identif., and Present. from the server. It interacts with an End user (Interactive) and a Download process. + +External interactions include: AR material (Import/Export), AR files, Content creators (Share), AR App (connected to App store), Manager (connected to App store), and End user (Interactive). + +Figure 9-1 – Reference framework of ARCSS. The diagram illustrates the interaction between the AR cloud creator, AR cloud management platform (Server), and Mobile device (Client). + +Figure 9-1 – Reference framework of ARCSS + +The entire system includes the AR cloud creation platform (creator), the AR cloud management platform and a mobile device. These three parts cooperate with each other to complete the content creation, content release and content rendering to the final presentation in front of the audience. + +### 9.1 AR cloud creation platform + +The AR cloud creation platform provides the ARCC with content production tools, object recognition and presentation tools, AR content management tools and AR project management tools through the login interface. The ARCC can import AR material to the platform to build a material library and make an AR file with the platform tools. The AR file is a unified AR format file that supports sound, video, text, animation, 3D model and other elements in the AR App. The ARCC can share these files and improve AR application productivity. When the content creator is packaged into an app, it is distributed to the app store, and the ARCU can download the corresponding app according to their device's own operating system. + +### 9.2 AR cloud management platform + +AR cloud management platform is the core of an ARCSS, which is operated and managed by the platform manager. It provides content management, resource management and runtime management + +services for ARCCs, user management and device management services for mobile devices, and cloud services for AR object recognition, and tracking and rendering for AR applications by building a supporting algorithm library. + +### 9.3 Mobile devices + +Mobile devices can be either a special perceived device, such as a tour guide in a cultural venue or a business display device, or a general mobile terminal for users. The ARCU scans the target object through an AR application and combines the services provided by the local recognition library and the AR cloud management platform to obtain the experience of combining the virtual with reality based on AR. + +## 10 Procedures of augmented reality cultural service + +Based on the reference framework of the ARCSS, the typical procedures of an AR cultural service are specified for the AR cloud creation platform, the AR cloud management platform and mobile device. + +### 10.1 AR content creation procedure + +AR content creation is the main function of the ARCC platform. Figure 10-1 describes the AR content creation procedure. + +![Sequence diagram of the AR content creation procedure involving ARCC, AR cloud creation platform, and AR cloud management platform.](8e14350b4b669119a3bdfca7869110ca_img.jpg) + +``` +sequenceDiagram + participant ARCC + participant ARCCP as AR cloud creation platform + participant ARCMP as AR cloud management platform + Note right of ARCCP: 4. AR content creation + ARCMP->>ARCCP: 1. AR content creating request + ARCCP->>ARCC: 2. AR request distribution/discovery + ARCC->>ARCCP: 3. AR materials upload + ARCCP->>ARCCP: 4. AR content creation + ARCCP->>ARCMP: 5. AR content response + ARCMP->>ARCCP: 6. AR content usage condition + ARCCP->>ARCC: 7. AR content usage statistics +``` + +The diagram illustrates the AR content creation procedure through a sequence of interactions between three entities: ARCC, AR cloud creation platform, and AR cloud management platform. The sequence starts with the AR cloud management platform sending a request to the AR cloud creation platform. The AR cloud creation platform then distributes the request to the ARCC. The ARCC uploads materials to the AR cloud creation platform. The AR cloud creation platform performs the content creation internally. It then sends a response to the AR cloud management platform, which in turn sends usage conditions back to the AR cloud creation platform. Finally, the AR cloud creation platform sends usage statistics to the ARCC. + +Sequence diagram of the AR content creation procedure involving ARCC, AR cloud creation platform, and AR cloud management platform. + +Figure 10-1 – AR content creation procedure + +In this procedure: + +- 1) The AR cloud creation platform receives a request for creating specified AR content. It is noted that the request should contain sufficient target identification diagrams and necessary AR content creation requirements. +- 2) The AR cloud creation platform publishes AR content production requirements, completes the docking with the ARCC, and realizes the discovery and distribution of AR content creation requirements. +- 3) The ARCC makes and uploads the basic materials of AR content to the AR cloud creation platform according to the requirements and completes the preparation work for AR content creation. +- 4) The ARCC makes use of AR content production tools and basic materials provided by the AR cloud creation platform to complete AR content creation. + +- 5) The AR cloud creation platform will feed back the AR content produced to the AR cloud management platform in the form of cloud service. +- 6) The AR cloud management platform feeds back the usage of AR content to the platform, including the number of times AR content is used, the number of users, frequency and other data. +- 7) The AR cloud creation platform collects statistics on the use of AR content and feeds the results back to the ARCC corresponding to the AR content. + +### 10.2 AR service management procedure + +AR service management is the main function of the AR cloud management platform. Figure 10-2 describes the AR service management procedure: + +![Sequence diagram of the AR service management procedure. Lifelines: AR cloud creation platform, AR cloud management platform, and PM (Platform Manager). The sequence is: 1. AR content submission from creation to management platform; 2. Put AR content in storage within the management platform; 3. AR content managing request from PM to management platform; 4. AR content management actions within the management platform; 5. AR content managing notification from management platform to creation platform; 6. AR content managing result from management platform to PM. A label F.740.2(21)_F10-2 is at the bottom right.](27b06ec9f42b5d727a2630f61a5f1861_img.jpg) + +``` + +sequenceDiagram + participant ACCP as AR cloud creation platform + participant AMP as AR cloud management platform + participant PM as PM + Note right of AMP: 2. Put AR content in storage + Note right of AMP: 4. AR content management actions + ACCP->>AMP: 1. AR content submission + AMP->>PM: 3. AR content managing request + AMP->>ACC: 5. AR content managing notification + AMP->>PM: 6. AR content managing result + +``` + +F.740.2(21)\_F10-2 + +Sequence diagram of the AR service management procedure. Lifelines: AR cloud creation platform, AR cloud management platform, and PM (Platform Manager). The sequence is: 1. AR content submission from creation to management platform; 2. Put AR content in storage within the management platform; 3. AR content managing request from PM to management platform; 4. AR content management actions within the management platform; 5. AR content managing notification from management platform to creation platform; 6. AR content managing result from management platform to PM. A label F.740.2(21)\_F10-2 is at the bottom right. + +**Figure 10-2 – AR service management procedure** + +In this procedure: + +- 1) The AR cloud management platform receives the AR content submission from the AR cloud creation platform. It is noted that the submission should contain necessary resources such as target identification diagrams. +- 2) The AR cloud management platform puts the submitted AR content in storage, including AR overlay content storage, AR target identification diagram storage and AR creator information storage, etc. +- 3) The platform manager sends AR content management requests to the AR cloud management platform, including the request for basic management of AR content information, such as editing, query and deletion, and the request for AR content state management and AR content resource management. +- 4) The AR cloud management platform will take actions according to the management request sent from the platform manager. +- 5) The AR cloud management platform will issue management action notification to the AR cloud creation platform if necessary. + +The AR cloud management platform will send the AR content managing result to the platform manager as the response to management actions. + +### 10.3 AR content display procedure + +AR content display is the main function of the AR mobile device. Figure 10-3 describes the AR content display procedure: + +![Sequence diagram of the AR content display procedure involving AR cloud management platform, Mobile device, and ARCU.](eefe19c5e14dc4d6c316b7f7fbb7d7d7_img.jpg) + +``` +sequenceDiagram + participant ARCU + participant Mobile device + participant AR cloud management platform + + Note right of ARCU: 1. AR service request with captured image or video + ARCU->>Mobile device: 1. AR service request with captured image or video + Note right of Mobile device: 2. Object recognition with local identification library + Mobile device->>AR cloud management platform: 3. AR content request with recognition result + Note left of AR cloud management platform: 4. Object recognition with cloud identification library if necessary + Note left of AR cloud management platform: 5. AR content query + AR cloud management platform->>Mobile device: 6. AR content + Note right of Mobile device: 7. AR content rendering + Mobile device->>ARCU: 8. AR content display +``` + +The diagram illustrates the AR content display procedure through a sequence of interactions between three entities: AR cloud management platform, Mobile device, and ARCU. The process begins with the ARCU sending an AR service request with a captured image or video to the Mobile device. The Mobile device then performs object recognition using its local identification library. It sends an AR content request with the recognition result to the AR cloud management platform. The platform performs object recognition with its cloud identification library if necessary and queries the AR content database. It then transmits the AR content to the Mobile device, which renders it. Finally, the ARCU displays the AR content superimposed on real objects on the screen. The diagram is labeled F.740.2(21)\_F10-3 at the bottom right. + +Sequence diagram of the AR content display procedure involving AR cloud management platform, Mobile device, and ARCU. + +**Figure 10-3 – AR content display procedure** + +In this procedure: + +- 1) A mobile device receives an AR service request with camera captured images or video stream of cultural relics and artworks from the ARCU. +- 2) The mobile device performs the calculation and comparison with the local identification library and the AR object recognition result is obtained. +- 3) An AR content request with object recognition result is transmitted to the AR cloud management platform. +- 4) The AR cloud management platform will perform the object recognition with the cloud identification library if the mobile device cannot identify the target. +- 5) The AR cloud management platform will query the AR content database with identification information. +- 6) The corresponding AR content will be transmitted to the mobile device. +- 7) The mobile device will render the AR content for target cultural relics and artworks. +- 8) The ARCU sees virtual content superimposed on real objects on the screen. + +## Bibliography + +- [b-ITU-T J.301] Recommendation ITU-T J.301 (2014), *Requirements for augmented reality smart television systems*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.740.3-202309-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg b/marked/F/T-REC-F.740.3-202309-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..38bdd7bc1d3581fbdc3cf6b035f618693dbe3846 --- /dev/null +++ b/marked/F/T-REC-F.740.3-202309-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:75efa8e3513a799767c04a0bb7bcd87a550f2378f5880629068581808c1c9f7f +size 7353 diff --git a/marked/F/T-REC-F.740.3-202309-I_PDF-E/27b22513fc27a0ff5f230b062ad3112f_img.jpg b/marked/F/T-REC-F.740.3-202309-I_PDF-E/27b22513fc27a0ff5f230b062ad3112f_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..5a395c15cfa4f2414b1d33d7cac24d1e32ffa705 --- /dev/null +++ b/marked/F/T-REC-F.740.3-202309-I_PDF-E/27b22513fc27a0ff5f230b062ad3112f_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:cd698242047b605c10ceb27e5bd34a113eff24e047557d848b956d067c0d0543 +size 62158 diff --git a/marked/F/T-REC-F.740.3-202309-I_PDF-E/367926125450c2bc3f4bdca9d59a62ba_img.jpg b/marked/F/T-REC-F.740.3-202309-I_PDF-E/367926125450c2bc3f4bdca9d59a62ba_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..95a0e25184a700d54a74192a8b8783b6b4b0d8f9 --- /dev/null +++ b/marked/F/T-REC-F.740.3-202309-I_PDF-E/367926125450c2bc3f4bdca9d59a62ba_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:187f958f1ece545f07ef3a77d9d90fb04ba352b0dd7bc9759b263169e0c88479 +size 13212 diff --git a/marked/F/T-REC-F.740.3-202309-I_PDF-E/acfc53eca625d62b38aa2563efa95c3e_img.jpg b/marked/F/T-REC-F.740.3-202309-I_PDF-E/acfc53eca625d62b38aa2563efa95c3e_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..121752903d4ca4179d9d5665489e399913c34c56 --- /dev/null +++ b/marked/F/T-REC-F.740.3-202309-I_PDF-E/acfc53eca625d62b38aa2563efa95c3e_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c58157d2ea4a9ad6e8dbc393cd4153ee555f407e2ef05cd7f3d623623d6325fc +size 13315 diff --git a/marked/F/T-REC-F.740.3-202309-I_PDF-E/raw.md b/marked/F/T-REC-F.740.3-202309-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..d0d8c921bc07d0088ef2ea0d8d8f15da295bc66f --- /dev/null +++ b/marked/F/T-REC-F.740.3-202309-I_PDF-E/raw.md @@ -0,0 +1,397 @@ + + +# Recommendation**ITU-T F.740.3 (09/2023)** + +SERIES F: Non-telephone telecommunication services + +Multimedia services + +--- + +### **Metadata for digital representation of cultural relics/artworks using augmented reality** + +![ITU logo](0538daaa5583c23e17db3a12f2281a55_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.740.3 + +# Metadata for digital representation of cultural relics/artworks using augmented reality + +## Summary + +The augmented reality cultural service system (ARCSS) is a kind of digital interpretation system based on augmented reality (AR). ARCSS is able to present a story or history behind cultural relics/artworks in a dynamic and actual fusion way. + +Recommendation ITU-T F.740.3 describes the information flows of augmented reality cultural service, including AR content creation information flow and AR content display information flow. Based on the information flows, this Recommendation specifies the metadata for digital representation of cultural relics/artworks using augmented reality. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.740.3 | 2023-09-13 | 16 | 11.1002/1000/15613 | + +## Keywords + +Artworks, augmented reality, cultural relics, metadata. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2023 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|----------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 2 | +| 6 Overview ..... | 2 | +| 7 Information flows of augmented reality cultural service..... | 2 | +| 7.1 Workflow of augmented reality cultural services ..... | 2 | +| 7.2 AR content creation information flow..... | 2 | +| 7.3 AR content display information flow ..... | 3 | +| 8 Metadata for ARCSS ..... | 3 | +| 8.1 AR content creation metadata ..... | 3 | +| 8.2 AR content display metadata..... | 5 | +| Bibliography..... | 7 | + + + +# Recommendation ITU-T F.740.3 + +## Metadata for digital representation of cultural relics/artworks using augmented reality + +## 1 Scope + +This Recommendation describes the metadata for digital representation of cultural relics/artworks using augmented reality. + +The scope of this Recommendation includes: + +- 1) Information flows of augmented reality cultural service system; +- 2) Metadata of augmented reality cultural service system. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T F.740.2] Recommendation ITU-T F.740.2 (2021), *Requirements and reference framework for digital representation of cultural relics and artworks using augmented reality*. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following term defined elsewhere: + +**3.1.1 augmented reality** [b-ITU-T J.301]: A type of mixed reality where graphical elements are integrated into the real world in order to enhance user experience and enrich information. + +### 3.2 Terms defined in this Recommendation + +None. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-------|-------------------------------------------| +| AR | Augmented Reality | +| ARCC | Augmented Reality Content Creator | +| ARCSS | Augmented Reality Cultural Service System | +| ARCU | Augmented Reality Content User | +| ARM | Augmented Reality Manager | +| RAM | Random Access Memory | +| ROM | Read-Only Memory | + +### 5 Conventions + +None. + +### 6 Overview + +Augmented reality cultural service system (ARCSS) is a kind of digital interpretation system based on augmented reality (AR), it can use AR technology with rich media forms, such as video, audio, and other media forms to present the story behind cultural relics/artworks in a dynamic and actual fusion way. ARCSS can increase the interest of visits to cultural venues and deepen understanding of cultural relics/artworks for the audience. + +There are three roles in an ARCSS, namely AR content creator (ARCC), AR manager (ARM) and AR content user (ARCU). ARCC is responsible for AR content creation and processing of artworks in cultural venues, while ARCUs use AR terminals to enjoy AR content in cultural venues. The ARM is responsible for the unified management of AR content and terminals via the ARCSS. + +### 7 Information flows of augmented reality cultural service + +#### 7.1 Workflow of augmented reality cultural services + +ARM is the core of ARCSS. The ARCC provides the ARM with AR content for the project, and the ARM stores and manages the AR content, and pushes the AR content to the ARCU according to the actual situation. The specific workflow of an augmented reality cultural service is shown in the Figure 1. + +![Figure 1 – Workflow of augmented reality cultural service](27b22513fc27a0ff5f230b062ad3112f_img.jpg) + +``` + +sequenceDiagram + participant ARCC + participant ARM + participant ARCU + + ARCC->>ARM: Registration + ARM-->>ARCC: AR request + ARCC->>ARCC: Content customization + ARCC->>ARM: AR content upload + ARCU->>ARCU: Equipment rental/software install + ARCU->>ARM: Registration + ARM->>ARM: Content/terminal management + ARM->>ARCU: AR content transmission + ARCU->>ARCU: AR representation + ARCU->>ARM: Status upload + ARM->>ARM: Content/terminal statistic + ARM->>ARCC: Statistic report transmission + ARCC->>ARCC: Content update + +``` + +Detailed description of Figure 1: The sequence diagram illustrates the interaction between three entities: AR Content Creator (ARCC), AR Manager (ARM), and AR Content User (ARCU). The process begins with ARCC registering with ARM. ARM then sends an AR request to ARCC. ARCC performs content customization and uploads the AR content to ARM. On the user side, ARCU performs equipment rental or software installation and then registers with ARM. ARM manages the content and terminals, then transmits AR content to ARCU. ARCU handles the AR representation and uploads status back to ARM. ARM performs content/terminal statistics and transmits a statistic report back to ARCC. Finally, ARCC may perform a content update based on the report, which loops back to the customization phase. + +**Figure 1 – Workflow of augmented reality cultural service** + +F.740.3(23) + +Figure 1 – Workflow of augmented reality cultural service + +#### 7.2 AR content creation information flow + +The AR content creation procedure and detailed steps between ARCC and the ARM via an AR cloud creation platform and AR cloud management platform have been described in [ITU-T F.740.2]. Before using ARCSS, the ARCC needs to register with the ARM and submit basic information of the creators. The ARCC uploads AR content to the ARM, including project + +2 Rec. ITU-T F.740.3 (09/2023) + +information data, identification information data and AR present data; ARM provides statistical data to the ARCC to show the usage of AR content. Figure 2 shows the AR content creation information flow. + +![Figure 2 – AR content creation information flow diagram showing data exchange between ARCC and ARM.](acfc53eca625d62b38aa2563efa95c3e_img.jpg) + +``` + +graph LR + ARCC[ARCC] -- "Registration data" --> ARM[ARM] + ARCC -- "AR content data" --> ARM + ARM -- "Statistics data" --> ARCC + style F740.3(23) fill:none,stroke:none + F740.3(23) + +``` + +Figure 2 – AR content creation information flow diagram showing data exchange between ARCC and ARM. + +**Figure 2 – AR content creation information flow** + +### 7.3 AR content display information flow + +AR content display procedure and detailed steps between the ARCU and ARM via an AR cloud management platform and mobile device have been described in [ITU-T F.740.2]. ARCU (terminals) need to register with the ARM and submit the basic information of terminals before accessing ARCSS. The AR terminals regularly upload the terminal status and usage to the ARM; and the ARM pushes the AR content data to the AR terminals. Figure 3 shows the AR content display information flow. + +![Figure 3 – AR content display information flow diagram showing data exchange between ARCU and ARM.](367926125450c2bc3f4bdca9d59a62ba_img.jpg) + +``` + +graph LR + ARCU[ARCU] -- "Registration data" --> ARM[ARM] + ARCU -- "Status data" --> ARM + ARM -- "AR application data" --> ARCU + style F740.3(23) fill:none,stroke:none + F740.3(23) + +``` + +Figure 3 – AR content display information flow diagram showing data exchange between ARCU and ARM. + +**Figure 3 – AR content display information flow** + +## 8 Metadata for ARCSS + +### 8.1 AR content creation metadata + +According to the AR content creation information flow, ARCSS content creation metadata should promote data interaction between AR content creation and AR management, specification registered AR content, information query and statistics. The metadata can be divided into AR registration metadata, project metadata, identification information metadata, present metadata, and statistical information metadata. Tables 1 to 5 shows the detailed metadata of AR content creation. + +**Table 1 – AR content registration metadata** + +| Element/attribute | Description | Type | +|-------------------|----------------------------------------------------------------------------------------------------------------------|---------------------| +| Creator_ID | AR content creator ID | integer | +| Creator_Name | Name of AR content creator | String | +| Creator_Org | Organization of AR content creator | String | +| Reg_Time | Time of registration | time | +| Other_metaInfo | Other metadata information of AR content creator that are saved as key-value, e.g.,
{'URL': "http://www.xxx.com"} | Map | + +**Table 2 – AR project metadata** + +| Element/attribute | Description | Type | +|-------------------|--------------------------------------------------------------------------------------------------------------|---------------------| +| Project_ID | AR project ID | integer | +| Project_Name | Name of AR project | String | +| Project_Location | Location of cultural venues where AR project is running | String | +| Project_Version | Version of AR project | String | +| Other_metaInfo | Other metadata information of AR project that are saved as key-value, e.g.,
{"URL": "http://www.xxx.com"} | Map | + +**Table 3 – AR identification information metadata** + +| Element/attribute | Description | Type | +|-----------------------|---------------------------------------------------------------------------------------------------------------------|---------------------| +| Identification_ID | AR identification ID | integer | +| Identification_Name | Name of AR identification | String | +| Identification_Image | Image file of AR identification | file | +| Project_ID | AR project ID which the identification belongs to | integer | +| Creator_ID | AR content creator ID which the identification is made by | integer | +| Identification_Object | Cultural relics/artworks as AR identification object | object | +| name | Cultural relics/artworks name | String | +| type | Cultural relics/artworks type, 2D or 3D | String | +| location | Location of Cultural relics/artworks in cultural venues | String | +| Other_metaInfo | Other metadata information of AR identification that are saved as key-value, e.g.,
{"URL": "http://www.xxx.com"} | Map | + +**Table 4 – AR present metadata** + +| Element/attribute | Description | Type | +|-------------------|---------------------------------------------------------------|---------| +| Present_ID | AR present ID | integer | +| Present_Name | Name of AR present | String | +| Identification_ID | AR Identification ID which the AR present is corresponding to | integer | +| Project_ID | AR project ID which the AR present belongs to | integer | +| Present_file | AR present file including 3D model, video, audio and so on | file | + +**Table 5 – AR statistical information metadata** + +| Element/attribute | Description | Type | +|-------------------|--------------------------------------------------------------------|--------------| +| Present_ID | AR present ID | integer | +| Installed_Num | Number of devices in which this AR present installed | integer | +| Use_Num | Number of uses of the AR present in all the devices in the project | integer | +| Period | Period of this statistic | [time, time] | + +### 8.2 AR content display metadata + +According to the AR content display information flow, ARCSS metadata promotes the data interaction between AR terminals and AR management, and regulates the registration, status detection and application distribution of AR terminals, which are specifically divided into AR device metadata, device status metadata and AR application metadata. Tables 6 to 8 show the detailed metadata for AR content display. + +**Table 6 – AR device metadata** + +| Element/attribute | Description | Type | +|-------------------|----------------------------------------------------------------------------------------------------------|---------------------| +| Device_ID | AR device ID | integer | +| Device_Info | Information of AR device | object | +| OS | Operating system of device, 'IOS' or 'Android' | String | +| Version | Version of AR device | String | +| Resolution | Screen resolution of AR device | [integer, integer] | +| ROM | ROM of AR device | integer | +| RAM | RAM of AR device | integer | +| Other_metaInfo | Other metadata information of AR device that are saved as key-value, e.g., {"URL": "http://www.xxx.com"} | Map | + +**Table 7 – AR device status metadata** + +| Element/attribute | Description | Type | +|--------------------------|---------------------------------------------------------------------------------------------------------------------------------------|-------------| +| Device_ID | AR device ID | integer | +| Present_ID | AR present ID to identify the media package | integer | +| Status_time | Time of status latest update | time | +| Status_value | Status value which 1 represents this device is online, 0 represents this device is offline, -1 represents this device is out of order | integer | + +**Table 8 – AR application metadata** + +| Element/attribute | Description | Type | +|--------------------------|----------------------------------------------------------|-------------| +| App_ID | AR application ID | integer | +| Project_ID | AR project ID which the AR application belongs to | integer | +| App_Version | Version of AR application | String | +| App_package | AR application package | file | +| Present_List | List of AR present ID which is include in AR application | [integer] | + +## Bibliography + +- [b-ITU-T G.1036] Recommendation ITU-T G.1036 (2022), *Quality of experience influencing factors for augmented reality services.* +- [b-ITU-T J.301] Recommendation ITU-T J.301 (2014), *Requirements for augmented reality smart television systems.* +- [b-ITU-T J.302] Recommendation ITU-T J.302 (2016), *System specifications of augmented reality smart television service.* + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.740.4-202309-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg b/marked/F/T-REC-F.740.4-202309-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..38bdd7bc1d3581fbdc3cf6b035f618693dbe3846 --- /dev/null +++ b/marked/F/T-REC-F.740.4-202309-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:75efa8e3513a799767c04a0bb7bcd87a550f2378f5880629068581808c1c9f7f +size 7353 diff --git a/marked/F/T-REC-F.740.4-202309-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg b/marked/F/T-REC-F.740.4-202309-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1a61a49f5aaf9614c5537ccf30e72be64a3a4f6e --- /dev/null +++ b/marked/F/T-REC-F.740.4-202309-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:3fd739b65d0b47bf8c590cafa5ed0289778f3ad7c33709c096dee3f929c58d0a +size 66884 diff --git a/marked/F/T-REC-F.740.4-202309-I_PDF-E/raw.md b/marked/F/T-REC-F.740.4-202309-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..d53dc7239dd37432088060a7c304a87e5ad0dcc9 --- /dev/null +++ b/marked/F/T-REC-F.740.4-202309-I_PDF-E/raw.md @@ -0,0 +1,390 @@ + + +# Recommendation**ITU-T F.740.4 (09/2023)** + +SERIES F: Non-telephone telecommunication services + +Multimedia services + +--- + +### **Metadata for image aesthetics assessment with aesthetic attributes in mobile terminal computational photography systems** + +![ITU logo](0538daaa5583c23e17db3a12f2281a55_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.740.4 + +# Metadata for image aesthetics assessment with aesthetic attributes in mobile terminal computational photography systems + +## Summary + +Image aesthetics assessment (IAA) aims to evaluate whether an image conforms to the aesthetic preferences of a potential audience. Recommendation ITU-T F.740.4 defines metadata for image aesthetics assessment with aesthetic attributes in a mobile terminal computational photography system. The metadata is divided into three dimensions according to the key roles: photographer, camera and viewer, and provides non-redundant, fundamental and representative aesthetic attributes of each dimension. The role-based metadata defined in this Recommendation can be used to guide the construction of IAA datasets, and to provide multiple aesthetic attributes evaluation for IAA. Moreover, sample collection requirements and qualifications for annotators are recommended to guide high quality data construction. + +### History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.740.4 | 2023-09-13 | 16 | 11.1002/1000/15614 | + +### Keywords + +Image aesthetics assessment, metadata, subjective evaluation. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2023 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-------------------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined within this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 2 | +| 6 Overview ..... | 2 | +| 7 The dimensions of metadata ..... | 2 | +| 8 Metadata for image aesthetics assessment..... | 3 | +| 8.1 Metadata of photographer..... | 3 | +| 8.2 Metadata of camera ..... | 3 | +| 8.3 Metadata of viewer ..... | 4 | +| 9 Requirements for sample collection ..... | 4 | +| 10 Requirements for labelling equipment and environment..... | 6 | +| Appendix I – Supplements for the qualification evaluation of annotators ..... | 8 | +| I.1 The qualification evaluation of annotators ..... | 8 | +| Bibliography..... | 9 | + + + +# Recommendation ITU-T F.740.4 + +## Metadata for image aesthetics assessment with aesthetic attributes in mobile terminal computational photography systems + +## 1 Scope + +This Recommendation defines metadata for image aesthetics assessment (IAA). The scope of this Recommendation includes: + +- 1) The structure of metadata for IAA. +- 2) The dimensions of metadata for IAA. +- 3) Requirements for sample collection. +- 4) Requirements for labelling equipment and environment. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following term defined elsewhere: + +**3.1.1 metadata** [b-ITU-T X.1255]: Structured information that pertains to the identity of users, systems, services, processes, resources, information or other entities. + +### 3.2 Terms defined within this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 aesthetic attributes:** Attributes that affect the human perception of image aesthetics, typically including both subjective and objective attributes. + +**3.2.2 image aesthetics assessment:** The process of evaluating the aesthetic quality of an image using computational techniques. + +**3.2.3 sample collection:** The process of acquiring the images involved in the construction of the dataset. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +IAA Image Aesthetics Assessment + +## 5 Conventions + +In this Recommendation: + +- The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. +- The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. +- The keywords "should" indicate a requirement that is not mandatory. It implies that a certain course of action is preferred and expected, but that there may be situations where it is not practical or feasible to follow the recommendation. + +## 6 Overview + +This Recommendation standardizes metadata related to image aesthetics assessment (IAA), the metadata is divided into three dimensions according to the key roles: photographer, camera and viewer, and provides non-redundant, fundamental and representative aesthetic attributes of each dimension. Three aspects are then recommended to ensure the quality of the dataset constructed by metadata guidance: firstly, sample collection requirements are recommended to ensure comprehensive samples. Secondly, once the samples that meet the requirements are collected, they will be annotated by annotators, thus the qualifications for annotators are recommended to ensure that the annotators have the relevant skills to provide high-quality annotations. Thirdly, the labelling equipment and environment also affect the annotation quality, and some requirements are recommended. + +## 7 The dimensions of metadata + +According to the logical structure, shown in Figure 1, IAA metadata for the mobile terminal computational photography system is divided into the following: + +- **Photographer** - Metadata mainly includes some aesthetic attributes manipulated by the photographer, which are related to photography techniques that photographers often use, such as image composition, colour, camera angle, etc. The image aesthetics can be evaluated indirectly from these attributes. +- **Camera** - Metadata mainly includes some aesthetic attributes that affect image quality, such as image noise, exposure, sharpness, etc. The image aesthetics can be evaluated indirectly from these attributes. +- **Viewer** - The aesthetic evaluation of an image ultimately depends on its viewer, and some attributes that are related to the viewer's cultural customs or content preferences. For example, if a person likes horses, he or she probably also likes an image of horses. The image aesthetics can be evaluated directly from these attributes. + +![Figure 1: The logical structure of metadata. A diagram showing three main categories: Photographer, Camera, and Viewer, each with associated attributes grouped under a 'Metadata' umbrella. Photographer attributes include Colour, Composition, and Camera angle. Camera attributes include Noisiness, Exposure, and Sharpness. Viewer attributes include Culture and custom, and Content preference. Each category has an ellipsis indicating more attributes. The entire structure is labeled 'Metadata' at the bottom.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +``` + +graph TD + subgraph Photographer + P1[Colour] + P2[Composition] + P3[Camera angle] + P4[...] + end + subgraph Camera + C1[Noisiness] + C2[Exposure] + C3[Sharpness] + C4[...] + end + subgraph Viewer + V1[Culture and custom] + V2[Content preference] + V3[...] + end + P1 --> Metadata((Metadata)) + P2 --> Metadata + P3 --> Metadata + P4 --> Metadata + C1 --> Metadata + C2 --> Metadata + C3 --> Metadata + C4 --> Metadata + V1 --> Metadata + V2 --> Metadata + V3 --> Metadata + +``` + +Figure 1: The logical structure of metadata. A diagram showing three main categories: Photographer, Camera, and Viewer, each with associated attributes grouped under a 'Metadata' umbrella. Photographer attributes include Colour, Composition, and Camera angle. Camera attributes include Noisiness, Exposure, and Sharpness. Viewer attributes include Culture and custom, and Content preference. Each category has an ellipsis indicating more attributes. The entire structure is labeled 'Metadata' at the bottom. + +F.740.4(23) + +**Figure 1 – The logical structure of metadata** + +## 8 Metadata for image aesthetics assessment + +The metadata of each dimension is composed of various attributes, and the annotation of each attribute is divided into multiple levels to distinguish the aesthetics. + +### 8.1 Metadata of photographer + +The photographer can adjust some key aesthetic attributes to enhance the aesthetics of the subject. In order to facilitate the evaluation of image aesthetics from a more professional perspective, the aesthetic attributes listed in Table 1 are mainly related to photography techniques. Each annotation level is divided into several levels, for example, 1~3 means the attribute has 3 different annotation levels. The level is recommended to be divided into: level 1: Inappropriate, level 2: Normal and level 3: Appropriate, to rate the appropriateness of these aesthetic attributes. + +**Table 1 – Metadata of photographer** + +| Attributes | Description | Level | Type | +|------------------|-------------------------------------------------------------------------------------|-------|---------| +| Composition | The spatial relationship between the subjects, the position of each visual element. | 1~3 | integer | +| Colour | The type and intensity of the colour. | 1~3 | integer | +| Camera angle | Shooting height, direction and distance. | 1~3 | integer | +| Light and shadow | The combination of light and shadow when shooting. | 1~3 | integer | +| Special skills | The special techniques used to express the aesthetics of the subject when shooting. | 1~3 | integer | + +### 8.2 Metadata of camera + +The camera mainly affects the image quality through some attributes, and further affects the aesthetics of the image. As shown in Table 2, each annotation level is divided into several levels, for example, 1~7 means the attribute has seven annotation levels. Sharpness, exposure, white balance, and saturation are rated with 5 levels, which are used to evaluate whether these attributes are appropriate during shooting. The level of sharpness is divided into: level 1: Severely blurred, + +level 2: Slightly blurred, level 3: Normal, level 4: Sharp and level 5: Extremely sharp. The level of exposure is divided into: level 1: Severely underexposed, level 2: Slightly underexposed, level 3: Normal, level 4: Slightly overexposed and level 5: Severely overexposed. The level of white balance is divided into: level 1: Too warm, level 2: Warm, level 3: Normal, level 4: Cold, and level 5: Too cold. The level of saturation is divided into: level 1: Too dim, level 2: Dim, level 3: Normal, level 4: Vivid, and level 5: Too vivid. Noisiness and artifact are rated with 3 levels: level 1: Severely, level 2: Slightly and level 3: None. Focus is rated with 3 levels: level 1: Severely defocused, level 2: Slightly defocused, level 3: Normal. + +**Table 2 – Metadata of camera** + +| Attributes | Description | Level | Type | +|---------------|--------------------------------------------------------------------------------------------------------------------------------|-------|---------| +| Sharpness | The clarity of image boundaries and details. | 1~5 | integer | +| Exposure | The amount of light that makes an image clear. | 1~5 | integer | +| White balance | The same general appearance as the colours in an original scene. | 1~5 | integer | +| Saturation | The vividness of the colour. | 1~5 | integer | +| Noisiness | The degree of random variation of brightness or colour information;
The isolated pixels that produce strong visual effects. | 1~3 | integer | +| Artifact | The degree of anomalies apparent or non-existent elements during visual representation. | 1~3 | integer | +| Focus | The accuracy of the object and range of focus during shooting. | 1~3 | integer | + +### 8.3 Metadata of viewer + +In the process of IAA, the image is finally evaluated by the viewer, so the viewer can directly determine whether the image is attractive. Unlike the previous dimensions of "camera" and "photographer", this dimension collects some inherent attributes that do not change with different application scenarios. The aesthetic attributes of viewer should be determined according to specific communities and the application scenario, which mainly includes two dimensions: content preference, and culture and custom, as shown in Table 3. For example, some people like "green", while others dislike "green", thus it is necessary to add annotation information, e.g., "Do you like the green colour?" to describe the preference. Each annotation level is divided into 2 Boolean levels, e.g., Level 0: Like, Level 1: Dislike. + +**Table 3 – Metadata of viewer** + +| Attributes | Description | Level | Type | +|--------------------|----------------------------------------------|-------|------| +| Content preference | Preferences for specific subjects. | 0, 1 | bool | +| Culture and custom | Preferences for specific culture and custom. | 0, 1 | bool | + +## 9 Requirements for sample collection + +When constructing a dataset, the sample images should be collected in a comprehensible scene and should also meet the sample coverages of each attribute. This Recommendation specifies the scene and sample coverages for each attribute in the sample collection, as well as some special coverages, including content size, shot distance, camera facing, etc., as shown in Table 4. + +**Table 4 – Requirements for sample collection** + +| Types | Scene | Coverages | +|------------------|-------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Composition | Natural scenery, urban scenery (indoor, outdoor), person (single, multiple, crowd) | Composition type (rule of thirds, centre, symmetry, diagonals and triangles, horizontal line), content size (small, medium, large), shot distance (long, medium, close) | +| Colour | Natural scenery, urban scenery (indoor, outdoor), person (single, multiple, crowd), night scene (indoor, outdoor) | Colour combination (complementary colours, monochromatic colours, analogous colours) | +| Camera angle | Natural scenery, urban scenery (indoor, outdoor), person (single, multiple, crowd) | Angle and position type (high, eye-level, low), content size (small, medium, large), shot distance (long, medium, close), camera facing (front, rear) | +| Light and shadow | Natural scenery, urban scenery (indoor, outdoor), person (single, multiple, crowd), night scene (Indoor, outdoor) | Light type (front, side, back, reflection), camera facing (front and rear), the state of motion (static, slow, fast) | +| Special skills | Natural scenery, urban scenery (indoor, outdoor), person (single, multiple, crowd), night scene (indoor, outdoor) | Skill type (virtual reality, panorama, rotation, achromatism), content size (small, medium, large), shot distance (long, medium, close), camera facing (front and rear) | +| Sharpness | Natural scenery, urban scenery (indoor, outdoor), person (single, multiple, crowd), night scene (indoor, outdoor) | Special sharpness (background with defocus, focus), content size (small, medium, large), shot distance (long, medium, close), camera facing (front and rear), the state of motion (static, slow, fast) | +| Exposure | Natural scenery, urban scenery (indoor, outdoor), person (single, multiple, crowd), night scene (indoor, outdoor) | Special exposure (day overexposed, day underexposed, night overexposed, night underexposed, night normal exposed), camera facing (front and rear), tone (high-key, mid-tone, low-key) | +| White balance | Natural scenery, urban scenery (indoor, outdoor), person (single, multiple, crowd), night scene (indoor, outdoor) | Light source (uniform, non-uniform, single, multiple), camera facing (front and rear), colour or texture type (foreground: mixed colour, orange, yellow, white, blue; background: monochromatic colour, pattern, wood grain) | +| Saturation | Natural scenery, urban scenery (indoor, outdoor), person (single, multiple, crowd), night scene (indoor, outdoor) | Colour type (pure colours: bright red, bright green, gray; mixed colours: white gray, magenta, pink, yellowish brown), camera facing (front and rear) | +| Noisiness | Natural scenery, urban scenery (indoor, outdoor), person (single, multiple, crowd), night scene (indoor, outdoor) | The state of motion (static, slow, fast), camera facing (front and rear) | + +**Table 4 – Requirements for sample collection** + +| Types | Scene | Coverages | +|----------|-------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Artifact | Natural scenery, urban scenery (indoor, outdoor), person (single, multiple, crowd), night scene (indoor, outdoor) | Artifact type (image ghost, image moire, image vignetting), the state of motion (static, slow, fast), camera facing (front and rear), content type (hair, striped clothing, checked clothing, brick walls, fences, electronic device screens) | +| Focus | Natural scenery, urban scenery (indoor, outdoor), person (single, multiple, crowd), night scene (indoor, outdoor) | Special sharpness (background with defocus, focus), camera facing (front and rear), the state of motion (static, slow, fast), shot distance (long, medium, close), content size (small, medium, large) | + +## 10 Requirements for labelling equipment and environment + +It is important to specify the specifications of the equipment and the environment when manually annotating image aesthetic datasets, as shown in Table 5. By doing so, it is possible to ensure that the annotations are accurate, consistent, and reliable, and that the results based on the annotations are meaningful and statistically robust. + +**Table 5 – Requirements for labelling equipment and environment** + +| Types | Requirements | +|---------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Labelling software | Multiple images should be able to be conveniently and continuously rated with scores. | +| Storage format | It is recommended to use a simple format, such as XML or JSON. | +| Management system | A data labelling platform should include an integrated management system to manage projects, data, and users, and should enable project managers to track project progress and user productivity and communicate with annotators about mislabelled data, as well as sampling for quality assurance. | +| Device image format | The format of the images (e.g., JPEG, PNG, TIFF) should be specified. | +| Device colour space | The colour space should be specified to ensure consistency and accuracy in the labelling of the images. Common colour spaces include RGB, grayscale, and CMYK. | +| Device resolution | This Recommendation states that the device used for labelling images should have a display with a high resolution to ensure that the image is displayed in its entirety. | +| Device brightness | The brightness level of the device should ensure that it is within the appropriate brightness range. | +| Device hue | The device should have accurate colour representation and good colour balance. It is recommended to use a device with a colour calibration tool to ensure accurate colour representation. | +| Device refresh rate | This Recommendation states that the device is able to display images smoothly while being used for labelling. A higher refresh rate can further improve the smoothness of the display. | +| Device contrast | The device should have a suitable contrast ratio to ensure good | + +**Table 5 – Requirements for labelling equipment and environment** + +| Types | Requirements | +|--------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| | image quality and visibility of details in the images. | +| Workstation settings | The workstation should be designed ergonomically, with the monitor placed at a comfortable viewing height and angle, and the keyboard and mouse positioned to encourage good posture. The monitor should also be positioned to reduce glare and reflections. | +| Ambient temperature | The temperature in the work area should be maintained at a comfortable level to ensure a conducive working environment. | +| Lighting | The lighting in the work area should be adequate for precise image labelling, but not so bright that it causes eye strain. A well-lit workspace with adjustable brightness and colour temperature can ensure optimal lighting conditions. | +| Rest breaks | Annotators should take regular rest breaks to avoid eye strain, fatigue, and repetitive stress injuries, during which time the labeller should look away from the monitor, stretch, and rest the eyes. | +| Training and supervision | Annotators should receive training on the labelling process and the use of the equipment, as well as ongoing supervision to ensure that the labelling process is accurate and consistent. | + +## Appendix I + +### Supplements for the qualification evaluation of annotators + +(This appendix does not form an integral part of this Recommendation.) + +### I.1 The qualification evaluation of annotators + +Since the annotation of image aesthetics is highly subjective, the evaluation of aesthetics is influenced by some background information of the annotators. Therefore, the qualifications of the annotators should be evaluated to ensure that the quality of their annotations is high enough. However, this is not mandatory and can be specifically formulated according to the actual application scenario. At the same time, the evaluation items need to be agreed upon by the annotators. The qualifications are shown in Table I.1. + +**Table I.1 – Qualification evaluation for annotators** + +| Types | Qualifications | +|---------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Attention to detail | Annotators should be meticulous and detail-oriented, as accuracy is crucial when annotating aesthetic image datasets. They should have the ability to identify and label important features in the images, such as colour, texture, and patterns, with precision and consistency. | +| Aesthetic sensitivity | Annotators should possess a sense of aesthetics as they will evaluate images based on their visual appeal. This requires a level of subjective judgment and the ability to identify visually attractive features. | +| Visual memory | Annotators should have a good visual memory as they need to remember and compare the details of different images while labelling them. | +| Technical proficiency | Annotators should be proficient with the software and tools used for the annotation process, including image annotation software and the hardware used for display and input. This will enable them to work efficiently and accurately, and minimize the risk of errors in the labelling process. Additionally, proficiency with the tools may also allow them to identify potential technical issues or glitches that could affect the accuracy or efficiency of the annotation process. | +| Consistency | Annotators should strive to maintain consistency in their labelling, applying the same standards and criteria to each image they annotate. This is particularly important when working in a team, as consistent labelling by all team members is essential for the accuracy and reliability of the annotations. | +| Communication skills | Annotators should have enough communication skills as they may need to ask questions or provide feedback to other team members, such as project managers or supervisors. Clear communication helps to ensure that everyone is on the same page and that the labelling process proceeds smoothly and accurately. | +| Patience and focus | Annotators should have the patience and focus to work on repetitive tasks for extended periods of time since annotating a large number of images can be a time-consuming process. | +| Receptiveness to training | Annotators should be willing to receive training and be open to feedback, as they may need to learn new skills or improve their performance during the course of the project. | + +## Bibliography + +[b-ITU-T X.1255] Recommendation ITU-T X.1255 (2013), *Framework for discovery of identity management information*. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; 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It features a blue globe with white lines representing latitude and longitude, and the letters 'ITU' in a bold, blue, sans-serif font overlaid on the globe. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.740.5 + +# Data collection and annotation requirements for automatic white balance (AWB) enhancement in mobile terminals for digital culture + +## Summary + +Recommendation ITU-T F.740.5 provides the collection procedure of data for automatic white balance (AWB) enhancement and describes the requirements for all steps, which includes the requirements for scene selecting, shooting setting, data capturing and illumination uniformity detecting. The requirements of data annotation are also described in this Recommendation, including the illumination colour, illumination indicator and device. The goal of this Recommendation is to improve the user experience during image data transmission, which is the most popular cultural behaviour. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.740.5 | 2023-09-13 | 16 | 11.1002/1000/15615 | + +## Keywords + +Annotation metadata, automatic white balance, computational photography, data collection, digital culture. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2023 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-----------------------------------------------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 2 | +| 6 Overview ..... | 2 | +| 7 Requirements of data collection ..... | 2 | +| 7.1 Data collection procedure and requirements ..... | 2 | +| 7.2 Procedure and requirement of illumination uniformity detecting ..... | 3 | +| 8 Requirements of data annotation ..... | 4 | +| 8.1 Requirements of illumination colour annotation..... | 4 | +| 8.2 Requirements of illumination indicator annotation..... | 4 | +| 8.3 Requirements of device annotation ..... | 4 | +| Appendix I – Supplements for illumination uniformity quantifying and illumination uniformity judging..... | 6 | +| I.1 Illumination uniformity quantifying: colour difference computation ..... | 6 | +| I.2 Illumination uniformity quantifying: coefficient of variation computation ... | 6 | +| I.3 Illumination uniformity judging..... | 6 | +| Bibliography..... | 7 | + + + +# Recommendation ITU-T F.740.5 + +## Data collection and annotation requirements for automatic white balance (AWB) enhancement in mobile terminals for digital culture + +# 1 Scope + +This Recommendation describes the procedure and the requirement for data collection and annotation for automatic white balance (AWB) enhancement under uniform illumination conditions in mobile terminals, which includes: + +- Requirements of the data collection procedure. +- Requirements of the data annotation. + +This Recommendation is intended to make the digital culture and social media related contents on mobile terminals more uniform and accurate during transmission. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 automatic white balance** [b-ISO/IEC 30118-4]: A technology of normalizing the effect of the captured scene's illumination such that all objects appear as if they were captured under ideal "white light". + +**3.1.2 metadata** [b-ITU-T X.1255]: Structured information that pertains to the identity of users, systems, services, processes, resources, information or other entities. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following term: + +**3.2.1 illumination uniformity**: The colour of illumination is the same across an entire raw image. This specific condition serves as the fundamental data requirement for existing automatic white balance (AWB) enhancement techniques. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-----|--------------------------| +| AWB | Automatic White Balance | +| CV | Coefficient of Variation | +| ISP | Image Signal Processing | + +MTCPS Mobile Terminal Computational Photography System + +RGB Red Green Blue + +# 5 Conventions + +In this Recommendation: + +- The keywords "**is recommended**" indicate a requirement that is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. +- The keywords "**is required to**" indicate a requirement that must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. + +# 6 Overview + +The sharing of photography works on social networks has become one of the main contents and plays an important role as a cultural dissemination medium. By sharing photography works, users can convey their visual concepts, values, and cultural backgrounds, thus promoting the dissemination of cultural diversity. Accurate automatic white balance (AWB) can present photography works with true colours, enhancing the audience's understanding and resonance with the cultural connotations conveyed in the works. As the enhancement of the AWB module is data-driven, the large and correct data (with uniform illumination) has a great impact on its training effect. Thus, it is necessary to standardize data collection and annotation. + +This Recommendation standardizes a data collection procedure for AWB module enhancement for digital culture. It provides the requirements for four parts: scene selecting, shooting setting, data capturing and illumination uniformity detecting. Moreover, the requirements for the metadata of illumination colour, and the illumination indicator device are also described in this Recommendation. By standardizing the collection procedure and annotation metadata, it is beneficial to the improvement of training data consistency and validity for AWB module enhancement, and will ultimately benefit the user experience on digital culture data transmission under different mobile terminals. + +# 7 Requirements of data collection + +## 7.1 Data collection procedure and requirements + +This Recommendation provides a data collection procedure for AWB module training to ensure the uniformity of illumination. Figure 1 shows the data collection procedure. + +![Flowchart of the data collection procedure for AWB module training. The process consists of four sequential steps: 1. Scene selecting (The scenes with uniform illumination are required), shown with an image of a color checker on a bench. 2. Shooting setting, which includes Illumination indicator, Shooting angle, and Shooting distance. 3. Data capturing (Capturing the image and storing as raw format), shown with a dark image of the color checker. 4. Illumination uniformity detecting, shown with the color checker and a red rectangle highlighting a portion of it. The steps are connected by arrows. A label F.740.5(23) is at the bottom right.](1c94fd3cebf58af136144f14160d128e_img.jpg) + +The diagram illustrates the data collection procedure for AWB module training. It consists of four sequential steps connected by arrows: + +- Scene selecting** (The scenes with uniform illumination are required): This step is accompanied by an image of a color checker placed on a wooden bench outdoors. +- Shooting setting**: This step includes three sub-components: Illumination indicator, Shooting angle, and Shooting distance. +- Data capturing** (Capturing the image and storing as raw format): This step is accompanied by an image of the color checker on the bench, but the image is significantly darker, representing raw data capture. +- Illumination uniformity detecting**: This step is accompanied by an image of the color checker on the bench with a red rectangle highlighting a specific area, likely for analysis. + +F.740.5(23) + +Flowchart of the data collection procedure for AWB module training. The process consists of four sequential steps: 1. Scene selecting (The scenes with uniform illumination are required), shown with an image of a color checker on a bench. 2. Shooting setting, which includes Illumination indicator, Shooting angle, and Shooting distance. 3. Data capturing (Capturing the image and storing as raw format), shown with a dark image of the color checker. 4. Illumination uniformity detecting, shown with the color checker and a red rectangle highlighting a portion of it. The steps are connected by arrows. A label F.740.5(23) is at the bottom right. + +**Figure 1 – Data collection procedure** + +The data collection procedure follows the following requirements: + +- 1) **Scene selecting.** This part is required to select scenes with uniform illumination. It is recommended to select open outdoor scenes, indoor scenes with uniform light sources, etc. + +- 2) **Shooting setting.** This part is required to include the following three parts: + - Illumination indicator. This part is required to have a standard neutral grey area, which can reflect actual illumination colour. + - Shooting angle. This part is required to avoid light sources appearing in the shooting range to keep the illumination uniform. + - Shooting distance. This part is required to ensure the standard neutral grey area in the captured image can be positioned. +- 3) **Data capturing.** This part is required to capture the image as the raw format. +- 4) **Illumination uniformity detecting.** This part is required to verify the illumination uniformity of captured images. The specific procedure and requirements of this part are further elaborated in clause 7.2. + +## 7.2 Procedure and requirement of illumination uniformity detecting + +To complete the fourth part of the data collection procedure, this Recommendation further provides a procedure for illumination uniformity detection. It is recommended to include five parts: preprocessing, illumination indicator locating, grey pixel locating, illumination uniformity detecting, and illumination uniformity judging. Figure 2 describes the procedure of illumination uniformity detection. + +![Flowchart of the illumination uniformity detecting procedure. The steps are: Preprocessing (Demosaicking, Saturated pixels and black level removing, Gamma correction) -> Illumination indicator locating (with image) -> Grey pixel locating (with image) -> Illumination uniformity quantifying (Grey pixel average value computation, Colour difference computation, CV computation) -> Illumination uniformity judging (Decision: CV < K? YES -> Keep image, NO -> Discard image).](b3baf3a29b67c7425d2562ddbc52f0cc_img.jpg) + +``` +graph LR; subgraph Preprocessing; P1[Demosaicking]; P2[Saturated pixels and black level removing]; P3[Gamma correction]; end; subgraph Illumination_indicator_locating; I1[Illumination indicator locating]; I2[Image with indicator]; end; subgraph Grey_pixel_locating; G1[Grey pixel locating]; G2[Image with grey pixels]; end; subgraph Illumination_uniformity_quantifying; Q1[Grey pixel average value computation]; Q2[Colour difference computation]; Q3[CV computation]; end; subgraph Illumination_uniformity_judging; J1{CV < K?}; J2[Keep image]; J3[Discard image]; end; Preprocessing --> Illumination_indicator_locating; Illumination_indicator_locating --> Grey_pixel_locating; Grey_pixel_locating --> Illumination_uniformity_quantifying; Illumination_uniformity_quantifying --> Illumination_uniformity_judging; J1 -- YES --> J2; J1 -- NO --> J3; +``` + +Flowchart of the illumination uniformity detecting procedure. The steps are: Preprocessing (Demosaicking, Saturated pixels and black level removing, Gamma correction) -> Illumination indicator locating (with image) -> Grey pixel locating (with image) -> Illumination uniformity quantifying (Grey pixel average value computation, Colour difference computation, CV computation) -> Illumination uniformity judging (Decision: CV < K? YES -> Keep image, NO -> Discard image). + +F.740.5(23) + +**Figure 2 – Illumination uniformity detecting procedure** + +The illumination uniformity detecting procedure follows the following requirements: + +- 1) **Preprocessing.** This part is required to convert raw image into a processed version. It is recommended to include three steps: demosaicking, saturated pixels and black level removal, and gamma correction. +- 2) **Illumination indicator locating.** This part is required to locate the illumination indicator that has standard neutral grey pixels in captured raw image. Note that the illumination indicator is recommended to be the Macbeth colour checker. +- 3) **Grey pixel locating.** This part is required to locate standard neutral grey pixels in the illumination indicator and return corresponding colour values. +- 4) **Illumination uniformity quantifying.** This part is required to quantify the illumination uniformity. It is recommended to compute the coefficient of variation (CV) for grey pixel values, which includes three parts: grey pixel average value computation, colour difference computation and CV computation. +- 5) **Illumination uniformity judging.** This part is required to recommend an approach to determine whether the captured illumination is uniform. It is recommended to judge with a threshold. In detail, if the CV value is below the threshold K indicating uniform illumination, the raw image will be retained and annotated; otherwise, if the CV value exceeds K indicating non-uniform illumination, the raw image will be discarded. + +# 8 Requirements of data annotation + +This Recommendation provides the requirements for the illumination colour annotation, illumination indicator annotation and shooting device annotation. The first two annotations are used to support the training of AWB module enhancement, and the third annotation is used to support the generalization training of AWB module enhancement. + +## 8.1 Requirements of illumination colour annotation + +The illumination colour information is required to calculate by averaging the red green blue (RGB) values of grey pixels in the illumination indicator of the collected raw image. + +Metadata of illumination colour information annotation is required as presented in Table 1. + +**Table 1 – Metadata of illumination colour annotation** + +| Fields | Description | Data type | +|---------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------| +| Illumination colour information | A three-dimensional vector where each component is a floating-point number representing the value of red (R), green (G) and blue (B) respectively. The value range for each component if from 0.0 to 1.0. | | + +## 8.2 Requirements of illumination indicator annotation + +The illumination indicator is used to capture the illumination colour. Because the illumination indicator contains grey pixels that affect the AWB enhancement effect, it is required be masked in the training processing of AWB module enhancement. Therefore, the location information of the illumination indicator is required to be annotated. + +Metadata of illumination indicator annotation is required as presented in Table 2. + +**Table 2 – Metadata of illumination indicator annotation** + +| Fields | Description | Data type | +|------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------| +| Illumination indicator information | A four-dimensional vector, where each component is a floating-point number representing the horizontal position of the top two vertices, the horizontal position of the bottom two vertices, the vertical position of the left two vertices, and the vertical position of the right two vertices of the illumination indicator, respectively. | | + +## 8.3 Requirements of device annotation + +The information of the device is required to include the device brand and image signal processing (ISP) model. + +Metadata of device information annotation is required as presented in Table 3. + +**Table 3 – Metadata of device annotation** + +| Fields | Description | Data type | +|--------------------|--------------------------------------------------------------------------------------------------------------------------------|------------------| +| Device information | A two-dimensional vector, where each component is a string representing the brand of device and the model of ISP respectively. | | + +## Appendix I + +### Supplements for illumination uniformity quantifying and illumination uniformity judging + +(This appendix does not form an integral part of this Recommendation.) + +### I.1 Illumination uniformity quantifying: colour difference computation + +Regarding the average value $G_{avg}$ as the base pixel, this step is suggested to compute the offset degree of each grey pixel for the illumination uniformity detection, which is the angle between the pixel vectors and their average vector $G_{avg}$ and is denoted as colour difference $A_i$ . + +$$A_i = \frac{180}{\pi} \arccos (G_i \cdot G_{avg})$$ + +### I.2 Illumination uniformity quantifying: coefficient of variation computation + +For uniform illumination, the colour difference of each grey pixel should be as similar as possible. It is suggested to regard the coefficient of variation (CV) as an index to quantify the degree of dispersion for colour difference. The lower value of CV refers to more uniform illumination. + +$$CV = \frac{std\{A_1, A_2, \dots, A_n\}}{mean\{A_1, A_2, \dots, A_n\}}$$ + +### I.3 Illumination uniformity judging + +It is suggested to collect a small-scale raw dataset under controlled standard illumination conditions to determine threshold K. Figure I.1 shows examples for the data with controlled standard uniform illuminations. It is suggested to acquire threshold K by taking the maximum value for most CVs, as in Figure I.2. + +![Figure I.1: Two side-by-side photographs of a teddy bear on a table. The left image shows the bear under a warm, yellowish light. The right image shows the bear under a cooler, bluish light. Both images include a color calibration target in the foreground.](63b78cd7d890992545bb7c9d365f9820_img.jpg) + +Figure I.1: Two side-by-side photographs of a teddy bear on a table. The left image shows the bear under a warm, yellowish light. The right image shows the bear under a cooler, bluish light. Both images include a color calibration target in the foreground. + +Figure I.1 – Examples for the captured images with uniform illuminations + +![Figure I.2: A graph showing the distribution of threshold K for raw images with uniform illuminations. The x-axis is labeled 'CV' and ranges from 0.0 to 1.0. The y-axis is labeled 'Experimental images'. A horizontal dashed line is drawn at the 0.80 mark on the x-axis, and a vertical dashed line is drawn at the 0.80 mark on the y-axis. The intersection of these lines is marked with a small circle. The text 'F.740.5(23)' is visible in the bottom right corner.](6c865810bad6a51ecc6afa635f9c3ca6_img.jpg) + +Figure I.2: A graph showing the distribution of threshold K for raw images with uniform illuminations. The x-axis is labeled 'CV' and ranges from 0.0 to 1.0. The y-axis is labeled 'Experimental images'. A horizontal dashed line is drawn at the 0.80 mark on the x-axis, and a vertical dashed line is drawn at the 0.80 mark on the y-axis. The intersection of these lines is marked with a small circle. The text 'F.740.5(23)' is visible in the bottom right corner. + +Figure I.2 – Distributions of threshold K for the raw images with uniform illuminations + +## Bibliography + +- [b-ITU-T X.1255] Recommendation ITU-T X.1255 (2013), *Framework for discovery of identity management information.* +- [b-ISO/IEC 30118-4] Recommendation ISO/IEC 30118-4, *Information technology – Open Connectivity Foundation (OCF) Specification – Part 4: Resource type specifications.* + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | 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It features a blue globe with white grid lines and the letters 'ITU' in a bold, blue, sans-serif font. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.740.9 + +# Requirements for enabling virtual reality services based on Internet protocol television architecture + +## Summary + +Recommendation ITU-T F.740.9 specifies the requirements and the Internet protocol television (IPTV) functional architecture for enabling virtual reality (VR) services. As presented in this Recommendation, VR services are integrated into IPTV services using two approaches: the thick client model, which performs all processing on the device, and the thin client model, which leverages cloud-based processing. The related functional components, service procedures, requirements, and interaction models are defined accordingly. + +With this Recommendation, IPTV service providers can enhance their offerings by supporting immersive VR experiences, including 360° panoramic content and interactive VR applications. These enhancements enable IPTV systems to deliver superior quality of experience (QoE) for VR services while maintaining interoperability with existing ITU-T IPTV related Recommendations. Furthermore, new user-centric VR service scenarios, such as single-user and multi-user immersive experiences, can be developed based on the capabilities specified in this Recommendation. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.740.9 | 2025-03-16 | 21 | 11.1002/1000/16255 | + +## Keywords + +Immersive experience, interactive applications, IPTV, VR, VR service. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2025 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|------------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 3 | +| 6 Overview ..... | 4 | +| 6.1 Relationship between services..... | 4 | +| 6.2 Relationship between ITU-T Recommendations ..... | 5 | +| 7 Enabling VR service base on IPTV functional architecture..... | 6 | +| 7.1 VR service characteristics ..... | 6 | +| 7.2 Implementing VR services with [ITU-T Y.1910] ..... | 7 | +| 7.3 Implementing VR services with [ITU-T H.705.1] ..... | 8 | +| 8 Service requirements ..... | 10 | +| 8.1 General aspects..... | 10 | +| 8.2 QoS and performance aspects ..... | 11 | +| 8.3 Security aspects including service and content protection ..... | 12 | +| 8.4 Network related aspects..... | 12 | +| 8.5 End systems and interoperability aspects ..... | 12 | +| 8.6 Middleware, application and content aspects..... | 12 | +| 9 Functional architecture ..... | 13 | +| 9.1 [ITU-T Y.1910] based architecture ..... | 13 | +| 9.2 [ITU-T H.705.1] based architecture ..... | 16 | +| 10 VR service procedure based on IPTV architecture..... | 16 | +| 10.1 VR content and metadata preparation ..... | 17 | +| 10.2 VR application initiation ..... | 18 | +| 10.3 VR application client initiation ..... | 19 | +| 11 Security considerations..... | 20 | +| Appendix I – VR service based on IPTV architecture and use cases ..... | 21 | +| I.1 VR service characteristics ..... | 21 | +| I.2 End-to-end service architecture for VR service ..... | 22 | +| I.3 User cases of VR service based on IPTV architecture ..... | 25 | +| Bibliography..... | 27 | + + + +# Recommendation ITU-T F.740.9 + +# Requirements for enabling virtual reality services based on Internet protocol television architecture + +# 1 Scope + +Virtual reality (VR) refers to a simulated environment rendered through visual and audio elements to create an immersive user experience. This Recommendation specifies the requirements and the functional architecture for enabling VR services based on Internet protocol television (IPTV) architecture, which includes: + +- The requirements and architecture for integrating VR services into IPTV functional architecture. +- The requirements and service models to support immersive and interactive VR applications. +- The related functional requirements and service procedures for VR services base on IPTV functional architecture. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T H.705.1] Recommendation ITU-T H.705.1 (2023), *Layered specification for the IPTV service platform functional architecture based on open service capabilities*. +- [ITU-T H.720] Recommendation ITU-T H.720 (2008), *Overview of IPTV terminal devices and end systems*. +- [ITU-T H.721] Recommendation ITU-T H.721(V3) (2022), *IPTV terminal devices: Basic model*. +- [ITU-T H.722] Recommendation ITU-T H.722 (2014), *IPTV terminal device: Full-fledged model*. +- [ITU-T H.723] Recommendation ITU-T H.723 (2016), *IPTV terminal device: Mobile model*. +- [ITU-T X.1191] Recommendation ITU-T X.1191 (2009), *Functional requirements and architecture for IPTV security aspects*. +- [ITU-T Y.1901] Recommendation ITU-T Y.1901 (2009), *Requirements for the support of IPTV services*. +- [ITU-T Y.1910] Recommendation ITU-T Y.1910 (2008), *IPTV functional architecture*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 content provider** [ITU-T Y.1910]: The entity that owns or is licensed to sell content or content assets. + +**3.1.2 delivery** [ITU-T Y.1910]: In the context of IPTV architecture, "delivery" is defined as sending contents to the end user. + +**3.1.3 end user** [ITU-T Y.1910]: The actual user of the products or services. + +**3.1.4 linear television (linear TV)** [ITU-T Y.1910]: A television service in which a continuous stream flows in real time from the service provider to the terminal device and where the user cannot control the temporal order in which contents are viewed. + +**3.1.5 Internet protocol television (IPTV)** [ITU-T Y.1901]: Multimedia services such as television/video/audio/text/graphics/data delivered over IP-based networks managed to support the required level of QoS/QoE, security, interactivity and reliability. + +**3.1.6 IPTV terminal function (ITF)** [ITU-T Y.1901]: The end-user function(s) associated with a) receiving and responding to network control channel messages regarding session set-up, maintenance, and tear-down, and b) receiving the content of an IP transport from the network and rendering. + +**3.1.7 IPTV terminal device** [ITU-T Y.1901]: A terminal device which has ITF functionality, e.g., an STB. + +**3.1.8 network provider** [ITU-T Y.1910]: The organization that maintains and operates the network components required for IPTV functionality. + +NOTE 1 – A network provider can optionally also act as service provider. + +NOTE 2 – Although considered as two separate entities, the service provider and the network provider can optionally be one organizational entity. + +**3.1.9 service provider** [b-ITU-T M.1400]: A general reference to an operator that provides telecommunication services to customers and other users either on a tariff or contract basis. A service provider may or may not operate a network. A service provider may or may not be a customer of another service provider. + +**3.1.10 terminal device (TD)** [ITU-T Y.1901]: An end-user device which typically presents and/or processes the content, such as a personal computer, a computer peripheral, a mobile device, a TV set, a monitor, a VoIP terminal or an audiovisual media player. + +**3.1.11 video on demand (VoD)** [ITU-T Y.1910]: A service in which the end user can, on demand, select and view video content and where the end user can control the temporal order in which the video content is viewed (e.g. the ability to start the viewing, pause, fast forward, rewind, etc.). + +NOTE – The viewing may occur sometime after the selection of the video content. + +**3.1.12 virtual reality (VR)** [b-ITU-T P.1320]: An environment that is fully generated by digital means. To qualify as virtual reality, the virtual environment should differ from the local environment. + +**3.1.13 virtual reality service** [b-ITU-T Q.1702]: The ability for users to access the sights and sounds of remotely located complex systems in real-time. + +## **3.2 Terms defined in this Recommendation** + +None. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +3D Three Dimensional + +CDF Content Delivery Functions + +CD&LCF Content Distribution and Location Control Functions + +| | | +|---------|-------------------------------------------------| +| CD&SF | Content Delivery and Storage Functions | +| EPG | Electronic Program Guide | +| GUI | Graphical User Interface | +| IP | Internet Protocol | +| IPTV | Internet Protocol Television | +| IPTV TD | Internet Protocol Television Terminal Device | +| ITF | IPTV Terminal Function | +| PC | Personal Computer | +| QoE | Quality of Experience | +| QoS | Quality of Service | +| RTP | Real-time Transport Protocol | +| SADS | Service and Application Discovery and Selection | +| SCF | Service Control Functions | +| SCP | Service and Content Protection | +| STB | Set-Top Box | +| TD | Terminal Device | +| TV | Television | +| UDP | User Datagram Protocol | +| UI | User Interface | +| VoD | Video on Demand | +| VR | Virtual Reality | +| VR HMD | Virtual Reality Head Mounted Device | + +# 5 Conventions + +In this Recommendation: + +- The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted, if conformance to this Recommendation is to be claimed. +- The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. +- The keywords "can optionally" indicate an optional requirement which is permissible, without implying any sense of being recommended. This term is not intended to imply that the vendor's implementation must provide the option, and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with this Recommendation. + +Requirements are identified using the following conventions: + +- Requirement number xx in subclause n.m is of the form R n.m-xx; +- Recommended requirement number yy in subclause n.m is of the form RR n.m-yy; +- Optional requirement number zz in subclause n.m is of the form OR n.m-zz. + +NOTE – Future issues of this Recommendation should never reuse previously assigned numbers. + +# 6 Overview + +Virtual reality (VR) is a virtual environment rendered with a delivered visual and audio scene, which gives a simulated experience to the user as an immersive feel of a virtual world, possibly supplemented with sensory devices. VR applications exhibit a wide range of versatility, spanning across various domains such as entertainment (film and television), gaming, education, e-commerce, travel, and healthcare, among others. Through the lens of application scenario classification, these diverse applications can be categorized, based on their intended audience, for consumer and industrial purposes. + +This Recommendation focuses on VR services for consumer purposes. + +The Internet protocol television (IPTV) system has proven to be a mature commercialized end-to-end multimedia system. [b-ITU-T Y-Suppl.5] presents IPTV interactive services such as educational applications, entertainment applications (such as games), communications services and information services. For virtual reality (VR) services, IPTV architecture is a suitable technological framework for service implementation. At the same time, existing IPTV users can also constitute a potential customer base for VR service providers. + +This Recommendation specifies the requirements of an IPTV system implementing VR service, aligning with the current ITU-T IPTV related Recommendations. + +## 6.1 Relationship between services + +According to [ITU-T Y.1910], IPTV is defined as "*multimedia services such as television/video/audio/text/graphics/data delivered over IP based networks managed to provide the required level of quality of service and experience, security, interactivity and reliability*". + +In [ITU-T H.720], an IPTV terminal device is "*a device or software entity that receives and presents media content, associated metadata, and interactive elements for the end user in an IPTV system*." IPTV terminal devices include set-top boxes, mobile devices, personal computers, and other devices that can be used to access IPTV services. + +As a multimedia service providing various forms of content such as video, audio, images, and digital scenes, VR services can be carried by the mature IPTV system, which provides high-quality multimedia services via Internet protocol (IP) networks. The IPTV system is a suitable carrier that can support various service modes and achieve end-to-end carrying, from content creation to user reception. Additionally, the IPTV system's wide coverage area offers convenience for the promotion and popularization of VR business. + +According to the description of IPTV domains presented in [ITU-T Y.1901], Figure 6-1 shows the relationship between VR services and IPTV and is provided in this Recommendation as an aid to understanding of the relationships between IPTV domains and VR service. These relationships in IPTV domains do not define a business model. Additionally, a single provider may play a role in multiple domains in the provision of an actual service. + +![Diagram of IPTV domains supporting VR service. The diagram is divided into four vertical panels: End user, Network provider, Service provider, and Content provider. The End user panel shows a VR terminal device and a monitor connected to a router. The Network provider panel shows a cloud icon and a server connected to the router. The Service provider panel shows a server connected to the router and another server. The Content provider panel shows a globe icon and a server connected to the router. Arrows indicate the flow of data from the Content provider through the Service provider and Network provider to the End user.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +The diagram illustrates the flow of VR service across four IPTV domains. From left to right, the domains are: + + +- End user:** Contains icons for a VR terminal device and a monitor. A blue line connects the VR terminal device to a router. +- Network provider:** Contains a cloud icon labeled 'VR service enabled network' and a server. A blue line connects the router to the cloud icon, and another blue line connects the router to the server. +- Service provider:** Contains a server icon labeled 'VR service' and another server. A blue line connects the cloud icon to the first server, and another blue line connects the first server to the second server. +- Content provider:** Contains a globe icon labeled 'VR content' and a server. A blue line connects the second server to the globe icon. + + The overall flow is indicated by a continuous blue line connecting the Content provider's globe icon back through the Service provider's servers, then through the Network provider's router, and finally to the End user's VR terminal device. A small text 'F.740.9(25)' is located at the bottom right of the diagram. + +Diagram of IPTV domains supporting VR service. The diagram is divided into four vertical panels: End user, Network provider, Service provider, and Content provider. The End user panel shows a VR terminal device and a monitor connected to a router. The Network provider panel shows a cloud icon and a server connected to the router. The Service provider panel shows a server connected to the router and another server. The Content provider panel shows a globe icon and a server connected to the router. Arrows indicate the flow of data from the Content provider through the Service provider and Network provider to the End user. + +**Figure 6-1 – IPTV domains supporting VR service** + +The four IPTV domains supporting VR services, the definitions of which are provided in clause 3, are: + +- Content provider: With VR content provided. +- Service provider: With VR service provided. +- Network provider: With VR service enabled. +- End user: With VR terminal device used. + +The functional elements constituting these four IPTV domains are described in more detail in clause 8. + +## 6.2 Relationship between ITU-T Recommendations + +In [b-ITU-T Y-Suppl.5], "*Supplement on IPTV service use cases*", various types of services supported by the IPTV system have been listed, including distributed content, interactive services, communication services, hosting services, presence services, etc. + +By offering VR services in an IPTV system, IPTV service providers may provide VR-enhanced versions of immersive TV programming, such as watching a live VR sports event delivered by an IPTV system, which would provide a more immersive and interactive experience than watching it on a traditional screen. Interactive services are also a good example of the combination of IPTV and VR services. Through the functions provided by the IPTV system, users can enjoy a better immersive interactive experience. + +By enabling VR services, the IPTV system can enhance the various services it offers with more immersive experiences and real-time interactions than those currently supported. The user cases listed in [b-ITU-T Y-Suppl.5] are extended in this Recommendation to account for VR-supported scenarios. Additionally, this Recommendation will also discuss IPTV service requirements for the support of VR services based on [ITU-T Y.1901]. + +The relationship of VR services with [ITU-T Y.1901] and [ITU-T Y.1910] is shown in Figure 6-2. + +![Diagram showing the relationship between Traditional IPTV services and VR enabled IPTV service. The diagram is split into two main columns. The left column, 'Traditional IPTV services', contains two boxes: '[b-ITU-T Y-Suppl.5] Supplement on IPTV service use cases' at the top and '[ITU-T Y.1901] Requirements for the support of IPTV services' at the bottom, connected by a dashed arrow labeled 'Req input'. The right column, 'VR enabled IPTV service', also contains two boxes: 'This Recommendation Appendix I Use cases for VR service based on IPTV architecture' at the top and 'This Recommendation Clause 8 service requirements NOTE – IPTV services requirements for the support of VR services' at the bottom, connected by a dashed arrow labeled 'Req input'. A dashed arrow labeled 'User cases extended' points from the top-left box to the top-right box. Another dashed arrow labeled 'Req extended' points from the bottom-left box to the bottom-right box. The entire right column is enclosed in a dashed rectangular box.](d4af765160d04ecef538e5066006dc77_img.jpg) + +Diagram showing the relationship between Traditional IPTV services and VR enabled IPTV service. The diagram is split into two main columns. The left column, 'Traditional IPTV services', contains two boxes: '[b-ITU-T Y-Suppl.5] Supplement on IPTV service use cases' at the top and '[ITU-T Y.1901] Requirements for the support of IPTV services' at the bottom, connected by a dashed arrow labeled 'Req input'. The right column, 'VR enabled IPTV service', also contains two boxes: 'This Recommendation Appendix I Use cases for VR service based on IPTV architecture' at the top and 'This Recommendation Clause 8 service requirements NOTE – IPTV services requirements for the support of VR services' at the bottom, connected by a dashed arrow labeled 'Req input'. A dashed arrow labeled 'User cases extended' points from the top-left box to the top-right box. Another dashed arrow labeled 'Req extended' points from the bottom-left box to the bottom-right box. The entire right column is enclosed in a dashed rectangular box. + +F.740.9(25) + +**Figure 6-2 – The relationship between this Recommendation and other ITU-T IPTV related Recommendations** + +# 7 Enabling VR service base on IPTV functional architecture + +## 7.1 VR service characteristics + +In contrast to conventional user interfaces, which confine end-users to screen-based interactions, VR service offers end-users a novel service experience characterized by seamless viewpoint transitions and frequent interactive actions. This environment facilitates interaction and engagement within a 3D space, capable of simulating reality or deviating significantly from it. + +From user experience perspective, VR services can be categorized into the immersive and non-immersive experiences: + +- Immersive 360° experience – Provides a full panoramic view and enhances the overall sense of immersion with headset devices. +- Non-immersive experiences – Limited to viewing content based on the orientation and movement of the device, such experiences are typically found in applications such as TV video games. + +In terms of content provision, VR services can be categorized into omnidirectional/panoramic video and computer-generated/synthesized environments based on the type of content provided: + +- Omni-directional/panoramic video – Provides a comprehensive visual and auditory experience by capturing natural scenes with specialized camera and microphone equipment. +- Computer-generated/synthetic environments – Use data models and algorithms to generate artificial views based on the current user behaviour and other inputs. + +Considering interaction service types, VR services can provide both weak and strong interaction services depending on the content and terminal capabilities: + +- Weak interaction services – Allow users to navigate 3D virtual environments from a single observation point. +- Strong interaction services – Support users to freely explore, observe and interact in artificial 3D environments. + +Furthermore, the integration of cloud technology into VR services introduces a cloud-based architecture, leading to the classification of the end-to-end VR service architecture into 2 models: + +- Thick client model – Includes all processing functions within the context of a single device. +- Thin client model – Minimizes the embedded functions within the client application to reduce the performance requirement of terminal devices. + +From the application's perspective, the user cases of VR services are categorized into two types based on the number of users, which mainly include: + +- Single user with single/multiple device(s) scenario – A single user with one or multiple terminal device(s) accesses and interacts with VR services. +- Multiple users with multiple devices scenario – Multiple users with multiple terminal devices access and interact with VR services. + +More information on VR service characteristics, end-to-end service architecture and user cases can be found in Appendix I. + +## 7.2 Implementing VR services with [ITU-T Y.1910] + +As a video streaming service similar to linear TV and video on demand (VoD), VR service involves the addition of VR service functional blocks based on the IPTV functional architecture defined in [ITU-T Y.1910]. Support requirements for the existing functional blocks are also required. As shown in Figure 7-1, the dark green blocks represent the newly added VR service modules, while the yellow blocks indicate the blocks that need to be enhanced for VR service. + +![Figure 7-1: Functional architecture for VR service based on IPTV architecture. The diagram shows a layered architecture with five main horizontal layers: End-user functions, IPTV terminal functions, Application functions, Service control functions, and Network functions. The Application functions layer includes IPTV application functions (Service and application discovery and selection, Linear TV application, On-demand application, and the new VR service application) and Content preparation functions (Content processing control, Content management, Metadata processing, and Content pre-processing). The Service control functions layer includes IPTV service control functions (IPTV service control and Service user profile) and Content delivery functions (Content distribution and location control, and Content delivery and storage). The Network functions layer includes Authentication and IP allocation, Resource control, Access network functions, Edge functions, and Core transport functions (Multicast transport and Unicast transport). The IPTV terminal functions layer includes Application client functions (Service and application discovery and selection, Linear TV client, On-demand client, and the new VR service client) and SCP client functions (Content protection, Service protection, and Control). The End-user functions layer includes Content delivery client functions (Error recovery, Unicast content delivery, and Multicast content delivery) and Home network functions (Authentication and configuration, and Delivery network gateway). Management functions (Application management, Service control management, Content delivery management, End-user device management, and Transport management) and Content provider functions (DRM rights, Metadata, and Content) are shown on the right side, interacting with the various layers. The diagram uses color-coding: dark green for new VR modules, yellow for enhanced modules, and light blue for existing IPTV modules.](410562339ce067fdc6fa41940c118658_img.jpg) + +Figure 7-1: Functional architecture for VR service based on IPTV architecture. The diagram shows a layered architecture with five main horizontal layers: End-user functions, IPTV terminal functions, Application functions, Service control functions, and Network functions. The Application functions layer includes IPTV application functions (Service and application discovery and selection, Linear TV application, On-demand application, and the new VR service application) and Content preparation functions (Content processing control, Content management, Metadata processing, and Content pre-processing). The Service control functions layer includes IPTV service control functions (IPTV service control and Service user profile) and Content delivery functions (Content distribution and location control, and Content delivery and storage). The Network functions layer includes Authentication and IP allocation, Resource control, Access network functions, Edge functions, and Core transport functions (Multicast transport and Unicast transport). The IPTV terminal functions layer includes Application client functions (Service and application discovery and selection, Linear TV client, On-demand client, and the new VR service client) and SCP client functions (Content protection, Service protection, and Control). The End-user functions layer includes Content delivery client functions (Error recovery, Unicast content delivery, and Multicast content delivery) and Home network functions (Authentication and configuration, and Delivery network gateway). Management functions (Application management, Service control management, Content delivery management, End-user device management, and Transport management) and Content provider functions (DRM rights, Metadata, and Content) are shown on the right side, interacting with the various layers. The diagram uses color-coding: dark green for new VR modules, yellow for enhanced modules, and light blue for existing IPTV modules. + +Figure 7-1 – Functional architecture for VR service based on IPTV architecture + +### IPTV terminal functions + +- The VR service client functional block interacts with the VR service application functional block to perform session management, service authorization, presentation of the content metadata and execution of the service logic for the VR service applications. +- The service and application discovery and selection (SADS) client functional block provides for the end user's discovery and selection of VR applications. + +### IPTV application functions + +- The VR service application functional block performs session management, service authorization, presentation of the content metadata and execution of the service logic for VR service applications. Both the thick client model and thin client model are recommended to be support. +- The application profile functional block for VR service includes VR service settings. + +### Content preparation functions + +- The content preparation functions are comprised of content management, metadata processing, content processing control and content pre-processing functional blocks. In VR service, these functional blocks are used to control the preparation and/or combination of VR content, as delivered by the VR content owner(s), into the required delivery format. + +### Service control functions + +- The IPTV service control functional block provides the functions to handle service initiation, modification and termination requests, perform service access control, and establish and maintain the network and system resources required to support the IPTV services requested by the IPTV terminal functions necessary for launching VR service application. + +### Content delivery client functions + +- The content delivery client functions are responsible for VR content reception in the IPTV terminal functions. + +### Content delivery functions + +- The content delivery functions (CDF) perform cache and storage functionalities and deliver VR content according to requests from the end-user functions with low latency. Both the thick client model and thin client model are recommended to be supported. + +## **7.3 Implementing VR services with [ITU-T H.705.1]** + +[ITU-T H.705.1] specifies a layered architecture of the IPTV service platform intended to provide open service capabilities for diversified IPTV services. In comparison with the high-level IPTV functional architecture defined in [ITU-T Y.1910], the layered architecture, as shown in Figure 7-2, decouples service logic from data resources and decomposes the functions of the IPTV service platform into more granular modules. + +![Figure 7-2 – Layered framework of IPTV service platform, as referenced in [ITU-T H.705.1]. The diagram shows four layers: Service presentation layer (L3), Service access control, Capability encapsulation layer (L2), and Data resource layer (L1).](33ed1f9b27c7c21c797aa928b0f06851_img.jpg) + +The diagram illustrates the layered framework of an IPTV service platform, organized into four horizontal layers separated by dashed lines. On the right side, a vertical column lists management functions: Operation and maintenance management, Upgrade management, Monitoring management, Logging management, and Security management. + +- Service presentation layer (L3):** The top layer, containing a single box labeled "User interface". +- Service access control:** The second layer, divided into two main sections: + - Service access:** Contains three boxes: "Request routing", "Flow control", and "Communication protocol translation". + - Service capability discovery:** Contains three boxes: "Service registration/deregistration", "Routing criteria configuration", and "Service monitoring". +- Capability encapsulation layer (L2):** The third layer, containing a large box labeled "Service capability" which is further divided into four sub-sections: + - Content management:** Contains five boxes: "Content acquisition service", "Content processing control service", "Content protection service", "Content distribution management service", and "UI template management service". + - Service navigation:** Contains seven boxes: "Service/application metadata service", "Broadcast content metadata service", "VoD content metadata service", "Cast metadata service", "Picture metadata service", "Navigation category metadata service", and "Content searching service". + - Service control:** Contains seven boxes: "User profile management service", "Application profile management service", "User authentication service", "Service/content package management service", "Content authorization service", "Content protection authorization service", and "Service/content subscription service". + - Content delivery:** Contains seven boxes: "Content distribution service", "User request scheduling service", "VoD content processing service", "Broadcast content processing service", "Access permission control service", "Audience measurement service", and "Unicast content delivery service". + Below these sub-sections are two additional boxes: "Content preprocessing service", "Metadata post-processing service", "Personalized recommendation service", "Charging and accounting service", "User events collecting and sharing service", "Session management service", and "Content consumption statistic service". +- Data resource layer (L1):** The bottom layer, containing a single box labeled "Data service". + +Figure 7-2 – Layered framework of IPTV service platform, as referenced in [ITU-T H.705.1]. The diagram shows four layers: Service presentation layer (L3), Service access control, Capability encapsulation layer (L2), and Data resource layer (L1). + +**Figure 7-2 – Layered framework of IPTV service platform, as referenced in [ITU-T H.705.1]** + +As an open platform construction, which is a supplement to the platform functional architecture of [ITU-T Y.1910], the layered structure and fine-grained modules are flexible to allow for new services integration. The requirements on all the related modules for VR service are as follows: + +### Data resource layer (L1) + +The data resource layer provides data storage and data serving capabilities for IPTV services. It supports diverse kinds of storage technology to meet different requirements of data reading and writing from the upper layer. + +- Data service modules in this layer provide data storage and data access solutions for massive data of IPTV services. It is required to support VR related data including VR content metadata, user profiles in VR service, etc. + +### Capability encapsulation layer (L2) + +The capability encapsulation layer isolates the upper applications from the underlying resources. In this Recommendation, applications for IPTV services are split into a set of fine-grained and collaborating services. + +- Service access control modules in this layer execute routing functionalities for service invocation. + - The service access module is required to distribute requests across the available VR service in cooperation with the service capability discovery module. + - The service capability discovery module is essential for the dynamical changes of service capabilities and is required to support VR service including service registration/deregistration, service registry management, etc. +- Service modules are built around business capabilities of IPTV services. Each service module enables a set of distinct features or functionalities by encapsulating business logic, computation, data access and other capabilities. + +- Content management service modules are required to support VR content aggregation, VR content life-cycle management, VR metadata processing and VR content pre-processing. +- Service navigation service modules are required to provide metadata of the VR service for IPTV and VR contents required by service navigation. +- Service control service modules are required to support VR service-related access control to network and service resources, including registration, authentication, authorization, subscription and other capabilities. +- Content delivery service modules are required to support VR content processing and VR content delivery functionalities for IPTV end users. + +### Service presentation layer (L3) + +The service presentation layer provides graphical user interface (GUI) or presentation capability needed by GUIs for all kinds of IPTV terminal devices defined in [ITU-T H.720], [ITU-T H.721], [ITU-T H.722] and [ITU-T H.723]. + +- User interface modules in this layer present organized IPTV services and contents and react to user interactions. The user interface is required to support VR service display including poster, content, etc. It is also required to support virtual reality head mounted device (VR HMD) display for an immersive interaction. + +### Operation and maintenance management + +The operation and maintenance (O&M) management module performs overall configuration and management for achieving secure operation and intelligent maintenance of IPTV services. The modules are required to support VR service-related functionalities including VR application upgrade management, VR service monitoring management, VR service logging management, and VR service security management. + +# **8 Service requirements** + +## **8.1 General aspects** + +### **General requirements** + +- R 8.1-01: It is required to support service navigation within VR service. +- R 8.1-02: It is required to provide convenient service control functionalities, including view angle adjustment and virtual environment exploration. +- R 8.1-03: It is required to support playback of VR audio-visual content. + +### **General recommendations** + +- RR 8.1-01: It is recommended to ensure the provision of seamless service switching between VR, linear TV, VoD and other services for user convenience. +- RR 8.1-02: It is recommended to support real-time interaction capability to facilitate the engagement with virtual objects in real-time. +- RR 8.1-03: It is recommended to support the connection of other devices to the IPTV TD for enhanced VR service experience. +- RR 8.1-04: It is recommended to collect terminal device (TD) information to enable the provision of customized VR services based on varying TD capabilities. + +### **General options** + +- OR 8.1-01: It can optionally provide support for adaptive playback functionality based on user preferences and usage conditions. + +### 8.1.1 Service offerings + +The general requirements and recommendations on service offerings of IPTV service can be found in clause 6.1.1 of [ITU-T Y.1901]. The extended requirements for VR service based on IPTV architecture are as follows: + +#### Requirements + +- R 8.1.1-01: It is required to support the provision and processing of VR content. +- R 8.1.1-02: It is required to support the rendering of VR contents. +- R 8.1.1-03: It is required to support a navigation interface for convenient service exploration and interaction. + +#### Recommendations + +- RR 8.1.1-01: It is recommended to support stable transmission of VR content to ensure an immersive experience. +- RR 8.1.1-02: It is recommended to support the provision of real-time interaction for to enhance the realism of the experience. +- RR 8.1.1-03: It is recommended to support service settings, including adjustments for audio and video quality, control sensitivity, etc. + +#### Options + +- OR 8.1-01: It can optionally provide support for gesture control or/and voice control to augment user interactivity and offer alternative methods of service navigation. + +### 8.1.2 Accounting and charging + +The general requirements and recommendations on accounting and charging service of IPTV service can be found in clause 6.1.2 of [ITU-T Y.1901]. There are no extended requirements for VR service based on IPTV architecture. + +### 8.1.3 Service consumption + +The general requirements and recommendations on service consumption of IPTV service can be found in clause 6.1.3 of [ITU-T Y.1901]. The extended requirements for VR service based on IPTV architecture are as follows: + +#### Recommendations + +- RR 8.1.3-01: It is recommended to support seamless navigation and switching between VR content and traditional 2D content to ensure a smooth transition for users. +- RR 8.1.3-02: It is recommended to support smooth playback of VR audio and video content to deliver an immersive experience. +- RR 8.1.3-03: It is recommended to support social features that enable users to interact and communicate with others within VR services, enhancing users' engagement. + +### 8.1.4 Miscellaneous + +The general requirements and recommendations on miscellaneous issues of IPTV service can be found in clause 6.1.4 of [ITU-T Y.1901]. There are no extended requirements for VR service based on IPTV architecture. + +## 8.2 QoS and performance aspects + +The general requirements and recommendations on quality of service (QoS) and performance of IPTV service can be found in clause 6.2 of [ITU-T Y.1901]. The extended requirements for VR service based on IPTV architecture are as follows: + +### Recommendations + +- RR 8.2-01: It is recommended to support continuous, reliable, and stable service quality to ensure an immersive VR service experience. +- RR 8.2-02: It is recommended to support real time interactive response. + +## 8.3 Security aspects including service and content protection + +The general requirements and recommendations on security of IPTV service can be found in clause 6.3 of [ITU-T Y.1901]. There are no extended requirements for VR service based on IPTV architecture. + +## 8.4 Network related aspects + +The general requirements and recommendations on network related aspects of IPTV service can be found in clause 6.4 of [ITU-T Y.1901]. There are no extended requirements for VR service based on IPTV architecture. + +## 8.5 End systems and interoperability aspects + +The general requirements and recommendations on end system and interoperability aspect of IPTV service can be found in clause 6.5 of [ITU-T Y.1901]. The extended requirements for VR service based on IPTV architecture are as follows: + +### Requirements + +- R 8.5-01: It is required to support the playback functionality of VR audio-visual content. +- R 8.5-02: It is required to support essential audio-visual content control functions, such as pause, fast forward, fast rewind, etc. + +### Recommendations + +- RR 8.5-01: It is recommended to support interactive functionality for engaging with virtual objects. +- RR 8.5-02: It is recommended to support connectivity with other devices that facilitate VR services, such as helmet-mounted displays, controllers, etc. + +### Options + +- OR 8.5-01: It can optionally support additional interaction methods and control options, such as gesture recognition and voice recognition, to offer end-users with diverse and flexible ways for service interaction. + +## 8.6 Middleware, application and content aspects + +The general requirements and recommendations on middleware, application and content aspects of IPTV service can be found in clause 6.6 of [ITU-T Y.1901]. The extended requirements for VR service based on IPTV architecture are as follows: + +### 8.6.1 Middleware + +#### Requirements + +- R 8.6.1-01: It is required to support the start-up and initialization function of the VR service application on the client side. +- R 8.6.1-02: It is required to support the start-up and initialization function of the VR service application on the server side. + +### 8.6.2 Metadata + +#### Requirements + +- R 8.6.2-01: The IPTV metadata is required to support the inclusion of information on VR services, aiding in the identification and accessibility of VR content. + +# 9 Functional architecture + +## 9.1 [ITU-T Y.1910] based architecture + +VR service involves the addition of VR service functional blocks based on the IPTV functional architecture defined in [ITU-T Y.1910]. If VR service is supported, multiple functional blocks as defined in [ITU-T Y.1910] are recommended to be enhanced for VR service. + +### 9.1.1 IPTV terminal functions + +The IPTV terminal functions (ITF) are responsible for collecting control commands from the end user and interacting with the application functions to obtain service information such as electronic program guide (EPG), content licenses and keys for decryption. They interact with the service control and content delivery functions to receive the IPTV services and also provide the capability for content reception, decryption and decoding. + +#### 9.1.1.1 Application client functions + +The application client functions exchange information with the IPTV application functions to support IPTV services and other interactive applications. + +- The service and application discovery and selection (SADS) client functional block is recommended to provide the capability for the end user to discover and select VR services and applications. +- The VR service client functional block is recommended to interact with the VR service application functional block to manage sessions, authorize services, present content metadata, and execute service logic for VR applications. + +#### 9.1.1.2 Service and content protection (SCP) client functions + +The service and content protection (SCP) client functions interacting with SCP functions is recommended to provide service and content protection for VR service. + +#### 9.1.1.3 Content delivery client functions + +The content delivery client functions receive and control the delivery of the content from the content delivery and storage functions (CD&SF). These functions are responsible for the content reception in the IPTV terminal functions. + +- The multicast content delivery client functional block is recommended to support receiving VR content from the multicast delivery functional block within the content delivery and storage functions. +- The multicast content delivery client functional block is recommended to support multicast stream selection between VR and non-VR content. +- The unicast content delivery client functional block is recommended to support receiving VR content from the unicast delivery functional block within the content delivery and storage functions. +- The unicast content delivery client functional block is recommended to support unicast stream selection between VR and non-VR content. +- The content delivery client functions can optionally include an error recovery client functional block. This functional block is recommended to perform error recovery on the VR + +content streams in conjunction with the error recovery functional block within the content delivery functions. + +### **9.1.2 Application functions** + +The application functions enable the end-user functions to select and purchase or rent a content item. + +#### **9.1.2.1 IPTV application functions** + +The IPTV application functions allow the IPTV terminal functions to select and purchase the content if desired. + +- The VR service application functional block performs session management, service authorization, presentation of the content metadata and execution of the service logic for VR service applications. Both the thick client model and thin client model are recommended to be supported. +- The service and application discovery and selection (SADS) functional block is recommended to receive metadata information about services and applications, which include VR services and applications, from the metadata processing functional block. The VR service description information and service discovery information is recommended to be generated and provided by SADS. + +#### **9.1.2.2 Service and content protection (SCP) functions** + +The service and content protection (SCP) functions control the protection of the services and content. Content protection includes control of accessing the content and the protection of content using methods such as encryption. Service protection includes authentication and authorization to access the services and optionally protection of the services using methods such as encryption. + +- The content protection functional block is recommended to control the protection of the VR content and is responsible for the management of the VR content rights and the keys used to encrypt and decrypt the VR content. +- The service protection functional block is recommended to control the protection of VR service, including authentication and authorization of access to the VR service and the protection of the VR service using methods such as encryption. + +#### **9.1.2.3 Application profile functional block** + +The application profile functional block for VR service can optionally include: + +- End-user settings which include information related to the capabilities of the end user's IPTV terminal devices supporting VR service. +- Parental control level for VR service. +- IPTV service action data which encompass information related to the actions the user can optionally have taken while accessing VR service, e.g. list of VR content that the user has ordered, and associated status. + +#### **9.1.2.4 Content preparation functions** + +The content preparation functions are comprised of content management, metadata processing, content processing control and content pre-processing functional blocks. These functional blocks may be used to control the preparation and/or combination of the content, as delivered by the content owner(s), into the required delivery format. + +- The content management functional block is recommended to manage the life-cycle of the VR content in compliance with commercial agreements with the content owner. +- The metadata processing functional block is recommended to obtain, manage and process the VR programme-related metadata from the metadata sources, via the content pre-processing + +functional block, and provides it to the VR service application functional block within IPTV application functions. + +- The content processing control functional block is recommended to controls transcoding and other functions while processing VR and non-VR content. +- The content pre-processing functional block is recommended to support VR content processing while performing all or some of the functions, such as transcoding, content packaging, content scheduling, content aggregation, content tracing, advertising-insertion, format conversion, resolution conversion, editing, etc. + +### **9.1.3 Service control functions** + +The service control functions (SCF) provide the functions to request and release network and service resources required to support the IPTV services. + +#### **9.1.3.1 IPTV service control functional block** + +The IPTV service control functional block is recommended to process requests from the VR service application, which is within the IPTV application functions, and forward it to the content delivery functions in order that the content delivery functions select the most appropriate content delivery and storage functions, for delivering the VR content to the end-user functions + +### **9.1.4 Content delivery functions** + +The content delivery functions (CDF) receive content from the application functions, store, process and deliver it to the end-user functions using the capabilities of the network functions, under control of the service control functions. + +#### **9.1.4.1 Content distribution and location control functions** + +The content distribution and location control functions (CD&LCF) control the content delivery and storage functions to optimize content distribution, selection and delivery of content to the IPTV terminal functions. + +The CD&LCF are comprised of two functional blocks: distribution control functional block and location control functional block. + +- The distribution policy for content distributed as files or streams is recommended to be different according to VR and non-VR content. +- The location control functional block is recommended to resolve the VR application information into the content location information. + +#### **9.1.4.2 Content delivery and storage functions** + +The content delivery and storage functions store and cache the content, process it under the control of content preparation functions and distribute it among instances of content delivery and storage functions based on the policy of content distribution and location control functions. + +- The content delivery control functional block is recommended to handle control functions related to VR content delivery and storage. +- The unicast delivery functional block is recommended to handle streaming and delivering, e.g. via real-time transport protocol (RTP) over user datagram protocol (UDP), VR content streams to the content delivery client functions via the network functions based on the use of the unicast protocols and mechanisms. +- The multicast delivery functional block is recommended to handle streaming and delivering (e.g., via RTP over UDP) VR content streams to the content delivery client functions via the network functions based on the use of the multicast protocols and mechanisms. + +- The cache and storage functional block is recommended to handle caching and storing the VR content. +- The distribution functional block is recommended to receive the VR content from the content preparation functions and distribute the VR content, which includes live streams or files. +- The content processing functional block is recommended to process the VR content under the control of the content processing control functional block. +- The error recovery functional block generates additional information for a VR content stream, either proactively or on request, such that the error recovery client functional block in the content delivery client functions can recover the VR content. + +## **9.2 [ITU-T H.705.1] based architecture** + +The layered architecture of IPTV service platform defined in [ITU-T H.705.1] is a supplement of platform functional architecture to [ITU-T Y.1910]. See clause 9.1 for detailed functional requirements of [ITU-T Y.1910] and clause 7.3 for related modules defined in [ITU-T H.705.1] supporting VR service. + +# **10 VR service procedure based on IPTV architecture** + +The VR service procedures, including VR content and metadata preparation, application initiation, and application client initiation, based on the IPTV architecture, as specified in [ITU-T Y.1910], are provided as a reference for service implementation. + +## 10.1 VR content and metadata preparation + +![Sequence diagram illustrating the VR content and metadata preparation procedure. The diagram shows interactions between Content provider functions, Content preparation functions (pre-processing, metadata processing, management, and control), Content delivery functions, Network functions, and IPTV application functions (VR service application).](365b54f616aff249b4e6c0edafdcb9b3_img.jpg) + +The sequence diagram illustrates the following steps for VR content and metadata preparation: + +- Content sent from Content provider functions to Content pre-processing FB. +- Metadata sent from Content provider functions to Metadata processing FB. +- VR metadata processing within Metadata processing FB. +- Metadata sent from Metadata processing FB to Content management FB. +- Content information sent from Content pre-processing FB to Content management FB. +- Content information sent from Content pre-processing FB to Content processing control FB. +- VR content management message generating within Content management FB. +- VR content management message transmission from Content management FB to Content processing control FB. +- VR content control message generating within Content processing control FB. +- VR content control message transmission from Content processing control FB to Content pre-processing FB. +- VR content processing within Content pre-processing FB. +- VR content and content scheduling transmission from Content pre-processing FB to Content delivery functions. +- Unicast and multicast channel establishment information sent from Content delivery functions to Network functions. +- Unicast and multicast channel establishing within Network functions. +- Metadata sent from Network functions to IPTV application functions. + +F.740.9(25) + +Sequence diagram illustrating the VR content and metadata preparation procedure. The diagram shows interactions between Content provider functions, Content preparation functions (pre-processing, metadata processing, management, and control), Content delivery functions, Network functions, and IPTV application functions (VR service application). + +**Figure 10-1 – VR content and metadata preparation procedure** + +Figure 10-1 illustrates the procedure of VR content and metadata preparation based on the IPTV architecture, with detailed descriptions of each step as follows: + +- 1 The content provider functions send content to the content pre-processing functional block. +- 2 The content provider functions send metadata to the metadata processing functional block. +- 3 The metadata processing functional block processes content metadata. +- 4 The metadata processing functional block sends metadata to the content management functional block. +- 5 The content pre-processing functional block sends content information to the content management functional block. +- 6 The content pre-processing functional block sends content information to the content processing control functional block. +- 7 The content management functional block generates content management signalling. +- 8 The content management functional block transfers management signalling to the content processing control functional block. + +- The content processing control functional block generates content processing control signalling according to the received management signalling. +- The content processing control functional block transfers content processing control signalling to the content pre-processing functional block. +- The content pre-processing functional block performs content processing according to the content processing signalling. +- The content pre-processing functional block transfers the configured policies and contents to content delivery functions. +- The content delivery functions pass information to the network functions to allow for the dynamic computation, establishment and maintenance of multicast trees. +- The network functions establish unicast and multicast channels. +- The metadata processing functional block sends metadata to the VR service application functional block (refer to [ITU-T Y.1910], clause 11.1.2, reference point A3). + +## 10.2 VR application initiation + +![Sequence diagram of VR application initiation procedure showing interactions between Management functions, Application functions, and IPTV application functions.](366a77fdefb0097b3289b4a011911390_img.jpg) + +``` + +sequenceDiagram + box Management functions + participant AMFB as Application management FB + end + box Application functions + participant APFB as Application provisioning FB + participant AProfFB as Application profile FB + box IPTV application functions + participant VSFB as VR service application FB + participant SADSFB as SADS FB + end + end + + AMFB->>APFB: 1. Application information sent + APFB->>APFB: 2. VR application addition + APFB->>AProfFB: 3. VR personalized application information sent + AProfFB->>AProfFB: 4. VR application and end-user settings processing + AProfFB->>SADSFB: 5. VR application information sent + AProfFB->>SADSFB: 6. Personalized configuration transmission + AProfFB->>VSFB: 7. Personalized application configuration transmission + +``` + +F.740.9(25) + +Sequence diagram of VR application initiation procedure showing interactions between Management functions, Application functions, and IPTV application functions. + +**Figure 10-2 – VR application initiation procedure** + +Figure 10-2 illustrates the procedure of VR application initiation based on the IPTV architecture, with detailed descriptions of each step as follows: + +- The application management functional block sends the application information to the application provisioning functional block. +- The application provisioning functional block adds the VR application and manages the life-cycle of the VR application. +- The application provisioning functional block sends VR personalized application information to the application profile functional block. + +- 4 The application profile functional block processes the VR application and end-user settings. +- 5 The application provisioning functional block sends VR application information to the SADS functional block. +- 6 The SADS functional block retrieves the application profiles from the application profile functional block (refer to [ITU-T Y.1910], clause 11.1.3, reference point A4). +- 7 The VR service application functional block retrieves the application profiles from the application profile functional block (refer to [ITU-T Y.1910], clause 11.1.4, reference point A5). + +## 10.3 VR application client initiation + +![Sequence diagram of VR application client initiation procedure. Lifelines: Application client functions (VR service client FB), Content delivery client functions, IPTV application functions (VR service application FB), Service control functions (IPTV service control FB), Content delivery functions, Network functions. The sequence shows network info request/return, user control transmission, authentication request, authentication processing (failed or passed), and content delivery.](552265bdbcf6d43d341fd018a9076269_img.jpg) + +``` + +sequenceDiagram + participant AC as Application client functions +VR service client FB + participant CDC as Content delivery client functions + participant IA as IPTV application functions +VR service application FB + participant SC as Service control functions +IPTV service control FB + participant CD as Content delivery functions + participant NF as Network functions + + Note right of SC: 1. Network information request + SC->>NF: 1. Network information request + Note right of NF: 2. Network information return + NF-->>SC: 2. Network information return + Note left of IA: 3. User control message transmission + AC->>IA: 3. User control message transmission + Note right of IA: 4. VR application service authentication request + IA->>SC: 4. VR application service authentication request + Note right of SC: 5. VR service authentication + SC->>SC: 5. VR service authentication + alt Authentication failed + Note left of AC: Authentication failed + Note right of SC: 6. Authentication failure message return + SC-->>IA: 6. Authentication failure message return + Note left of AC: 7. Authentication failure message synchronization + IA-->>AC: 7. Authentication failure message synchronization + else Authentication passed + Note left of AC: Authentication passed + Note right of SC: 6'. Authentication passed, VR content service request + SC->>CD: 6'. Authentication passed, VR content service request + Note left of CD: 7'. VR content delivery + CD-->>CDC: 7'. VR content delivery + end + +``` + +F.740.9(25) + +Sequence diagram of VR application client initiation procedure. Lifelines: Application client functions (VR service client FB), Content delivery client functions, IPTV application functions (VR service application FB), Service control functions (IPTV service control FB), Content delivery functions, Network functions. The sequence shows network info request/return, user control transmission, authentication request, authentication processing (failed or passed), and content delivery. + +**Figure 10-3 – VR application client initiation procedure** + +Figure 10-3 illustrates the procedure of VR application client initiation based on the IPTV architecture, with detailed descriptions of each step as follows: + +- 1 The IPTV service control functional block requests network information from the network functions (refer to [ITU-T Y.1910], clause 11.2.8, reference point S4). +- 2 The network functions return the network information to the IPTV service control functional block. +- 3 The VR service client functional block transmits user control signalling to the VR service application functional block. +- 4 The VR service application functional block sends a VR service authentication request to the IPTV service control functional block (refer to [ITU-T Y.1910], clause 11.2.1, reference point A1). +- 5 The IPTV service control functional block performs authentication processing. + +NOTE 1 – The authentication failed scenario is handled as the following sub-procedure: + +- 6 If authentication fails, the IPTV service control functional block returns an authentication failure message to the VR service application functional block. +- 7 The VR service application functional block sends the authentication failure message to the VR service client functional block. + +NOTE 2 – The authentication success scenario is handled as the following sub-procedure: + +- 6' If authentication succeeds, the IPTV service control functional block initiates a content service request to the content delivery functions (refer to [ITU-T Y.1910], clause 11.2.5, reference point S1 or clause 11.2.9, reference point S5). +- 7' The content delivery functions transfer VR content to the content delivery client functions. + +# **11 Security considerations** + +As far as the security requirements of VR service based on IPTV architecture are concerned, the requirements contained in [ITU-T X.1191] are applicable. While providing VR services based on the IPTV architecture, providers should consider other security issues and ensure the use of IPTV security mechanisms to prevent unauthorized access, authenticate services and applications, and manage content with protection-related metadata. + +# Appendix I + +## VR service based on IPTV architecture and use cases + +(This appendix does not form an integral part of this Recommendation.) + +## I.1 VR service characteristics + +This clause outlines the characteristics of VR services in terms of the user experience, content provision and interaction modes. + +From a user experience perspective, VR service encounters can be categorized into two distinct types: immersive experience and non-immersive experience. The distinction in these two experiences is contingent upon the participant's viewpoint and is elucidated through the concept of spatial presence, defined as the "sense of being in an environment." + +- Immersive 360° experience provides end-users with a profound sense of presence, making them feel as though they are situated within the virtual environment. Utilizing HMD VR support, end-users can experience a comprehensive panorama, heightening the overall sense of immersion. This form of VR service extends beyond the boundaries of physical surroundings, encompassing both auditory and visual elements for a complete and immersive experience. +- Non-immersive experience restricts end-users to viewing content based on the orientation and movement of the device in use. In the context of non-immersive 360° environments, end-users can navigate and observe the panoramic content by manipulating the device, such as a set-top box (STB), PC, smartphone, or tablet. Notably, end-users remain externally situated, as the virtual space is solely displayed on a screen. This form of VR service is characterized by computer-generated settings with user-controlled navigation and commonly found in applications such as TV video games. + +The user experience of immersive 360° and non-immersive are shown in Figure I.1. + +![Figure I.1: Comparison of Immersive 360° experience and Non-immersive experience. The diagram shows two side-by-side panoramic views of a rural landscape. The left view, labeled 'Immersive 360° experience', is shown through a VR headset icon, indicating a first-person perspective. The right view, labeled 'Non-immersive experience', is shown on a screen with a set-top box (STB) icon, indicating a third-person perspective. Both views include a '360°' rotation symbol.](1695df64fe320e3f81049cfe402c8155_img.jpg) + +The diagram illustrates two distinct user experiences for 360-degree VR content. On the left, under the heading 'Immersive 360° experience', a panoramic landscape is shown through the lens of a VR headset icon, representing a first-person, 'inside' perspective. On the right, under the heading 'Non-immersive experience', the same panoramic landscape is shown on a television screen, with a set-top box (STB) icon below it, representing a third-person, 'outside' perspective. Both images include a circular arrow icon labeled '360°' to indicate the interactive viewing capability. + +Figure I.1: Comparison of Immersive 360° experience and Non-immersive experience. The diagram shows two side-by-side panoramic views of a rural landscape. The left view, labeled 'Immersive 360° experience', is shown through a VR headset icon, indicating a first-person perspective. The right view, labeled 'Non-immersive experience', is shown on a screen with a set-top box (STB) icon, indicating a third-person perspective. Both views include a '360°' rotation symbol. + +F.740.9(25) + +Figure I.1 – Immersive 360° experience non-immersive experience + +By simulating multiple sensory modalities, including vision, hearing, and occasionally touch, a VR terminal device assumes the role of a gateway to a virtual environment. As a user-centric IP-based multimedia service, VR service provides both a traditional streaming service and a computer-generated interactive service. Based on the different types of content provided, VR service can be basically classified into 2 types: + +- Omnidirectional/panoramic video employs a specialized camera and microphone rig to capture natural scenes, resembling a television system but with an unrestricted viewing arc. This methodology facilitates a comprehensive and immersive visual and auditory experience. +- Computer-generated/synthetic environments utilize data models and algorithms to generate an artificial view based on the current pose and other input stimuli. This type of service is + +prominently exemplified in VR games, showcasing the application of computational processes to construct immersive digital landscapes. + +The user experiences of omnidirectional/panoramic video and computer-generated/synthetic environments are shown in Figure I.2. + +![Figure I.2: Omnidirectional/panoramic video and computer-generated/synthetic environments](ac4da3ce8896f1f13e0706723ea0470d_img.jpg) + +Figure I.2 consists of two side-by-side images. The left image, titled 'Omnidirectional/panoramic video', shows a wide-angle view of a suburban street at sunset, with a '360°' icon indicating the panoramic nature. The right image, titled 'Computer-generated/synthetic environments', shows a person wearing a VR headset and holding a controller, interacting with a virtual environment that appears to be a snowy, futuristic landscape with a large moon in the sky. A small text 'F.740.9(25)' is visible in the bottom right corner of the right image. + +Figure I.2: Omnidirectional/panoramic video and computer-generated/synthetic environments + +**Figure I.2 – Omnidirectional/panoramic video and computer-generated/synthetic environments** + +Based on VR content and terminal capabilities, the interactive service modes offered by VR service to end-users can be classified into two types: + +- Weak interactive services allow end-users navigate a 3D virtual environment from a singular observation point, facilitated either by a producer's orchestration or the positioning of capturing devices. The incorporation of 360° video content, complemented by captured audio, forms the basis for enabling immersive VR services. This is particularly relevant for VR scenes characterized by low levels of interactivity, as encountered in scenarios such as VR live broadcast and VR video-on-demand. +- Strong interactive services allow end-users navigate, observe, and interact within this artificial 3D environment, fostering a heightened level of immersion. This includes the ability to freely explore the virtual landscape, examine surroundings, and engage with virtual features and items. A typical application scenario is VR game. + +The user experiences of weak interactive service and strong interactive service are shown in Figure I.3. + +![Figure I.3: Weak interactive service and strong interactive service](e3c1d325b828c44049a7ac37e5b34603_img.jpg) + +Figure I.3 consists of two side-by-side images. The left image, titled 'Weak interactive service', shows a user interface for a VR application, displaying a grid of thumbnail images and a sidebar with navigation options. The right image, titled 'Strong interactive service', shows a person wearing a VR headset and holding a controller, interacting with a virtual environment that appears to be a snowy, futuristic landscape with a large moon in the sky. A small text 'F.740.9(25)' is visible in the bottom right corner of the right image. + +Figure I.3: Weak interactive service and strong interactive service + +**Figure I.3 – Weak interactive service and strong interactive service** + +## I.2 End-to-end service architecture for VR service + +In the consumer domain, the VR application is primarily centred around entertainment, with gaming and 360° panoramic videos playing a pivotal role in driving adoption. The objective of implementing + +an interactive, real-time visualization system imposes constraints such as high terminal device computing performance and visual quality, shaping the supported visualization methods. + +NOTE – Architecture on cloud computing in [b-ITU-T Y.3502] and reference framework for cloud virtual reality systems in [b-ITU-T F.746.14] are considered. + +The establishment of interoperable end-to-end ecosystems is imperative for immersive content production and delivery, marking a shift from local device storage to a cloud-based model. The integration of cloud technology into VR service introduces a cloud-based architecture, leading to the classification of the end-to-end VR service architecture into two models: + +- Thick client model – Includes all processing functions within the context of a single device. Content is either retrieved from local storage or processed for rendering or data streams are obtained from network services for processing. Figure I.4 shows a reference end-to-end architecture. + +![Figure I.4 – End-to-end architecture of thick client VR service model. The diagram shows four main layers: Hardware layer, Client-side application layer, Network layer, and Server-side application layer. The Hardware layer includes Terminal hardware (Audio, Display) and Input hardware (Buttons, Haptics, Head-tracking, Hand-tracking, Microphone). The Client-side application layer includes View processing (Audio-visual player, 3D render, UI, Haptic feed), Data processing (VR engine (Client side), Static/dynamic data (Audio, video, picture, etc.)), and Data handler (Telemetry, Audio, Basic control (Direction, etc.)). The Network layer includes Data transmission (Content delivery system, IP network). The Server-side application layer includes Data processing (Streamer, VR engine (Server side)), Data storage (Audio/video content, Metadata, User profile), and Data handler (Transmission control). Arrows show data flow between components within the client layer and between the client layer and the network layer.](474a819357587e34949a3e110ff19b30_img.jpg) + +The diagram illustrates the end-to-end architecture of a thick client VR service model, organized into four vertical layers: + +- Hardware layer:** + - Terminal hardware:** Audio, Display. + - Input hardware:** Buttons (Remoter, keyboard, etc.), Haptics, Head-tracking, Hand-tracking, Microphone. +- Client-side application layer:** + - View processing:** Audio-visual player, 3D render, UI, Haptic feed. + - Data processing:** VR engine (Client side), Static/dynamic data (Audio, video, picture, etc.). + - Data handler:** Telemetry, Audio, Basic control (Direction, etc.). +- Network layer:** + - Data transmission:** Content delivery system, IP network. +- Server-side application layer:** + - Data processing:** Streamer, VR engine (Server side). + - Data storage:** Audio/video content, Metadata, User profile. + - Data handler:** Transmission control. + +Arrows indicate the flow of data and control signals between components within the client layer and between the client layer and the network layer. + +Figure I.4 – End-to-end architecture of thick client VR service model. The diagram shows four main layers: Hardware layer, Client-side application layer, Network layer, and Server-side application layer. The Hardware layer includes Terminal hardware (Audio, Display) and Input hardware (Buttons, Haptics, Head-tracking, Hand-tracking, Microphone). The Client-side application layer includes View processing (Audio-visual player, 3D render, UI, Haptic feed), Data processing (VR engine (Client side), Static/dynamic data (Audio, video, picture, etc.)), and Data handler (Telemetry, Audio, Basic control (Direction, etc.)). The Network layer includes Data transmission (Content delivery system, IP network). The Server-side application layer includes Data processing (Streamer, VR engine (Server side)), Data storage (Audio/video content, Metadata, User profile), and Data handler (Transmission control). Arrows show data flow between components within the client layer and between the client layer and the network layer. + +F.740.9(25) + +**Figure I.4 – End-to-end architecture of thick client VR service model** + +- Thin client model – Minimizes the embedded functions within the client application to reduce the performance requirement of the terminal device. This approach relies on network connectivity to transmit inputs to processing functions and retrieve the requisite stream for display, emphasizing a streamlined and network-dependent operational model. Figure I.5 shows a reference end-to-end architecture. + +![Figure I.5 – End-to-end architecture of thin client VR service model. The diagram shows four vertical layers: Hardware layer, Client-side application layer, Network layer, and Server-side application layer. The Hardware layer includes Terminal hardware (Audio, Display) and Input hardware (Buttons, Haptics, Head-tracking, Hand-tracking, Microphone). The Client-side application layer includes View processing (Audio-visual player, UI, Haptic feed), Data processing (Transmission control), and Data handler (Telemetry, Audio, Basic control). The Network layer includes Data transmission (Content delivery system, IP network). The Server-side application layer includes Data processing (Streamer, Audio-visual encoder, 3D render, VR engine), Data storage (Audio/video content, Metadata, User profile), and Data handler (Transmission control). Arrows show data flow between components across layers.](11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg) + +Figure I.5 – End-to-end architecture of thin client VR service model. The diagram shows four vertical layers: Hardware layer, Client-side application layer, Network layer, and Server-side application layer. The Hardware layer includes Terminal hardware (Audio, Display) and Input hardware (Buttons, Haptics, Head-tracking, Hand-tracking, Microphone). The Client-side application layer includes View processing (Audio-visual player, UI, Haptic feed), Data processing (Transmission control), and Data handler (Telemetry, Audio, Basic control). The Network layer includes Data transmission (Content delivery system, IP network). The Server-side application layer includes Data processing (Streamer, Audio-visual encoder, 3D render, VR engine), Data storage (Audio/video content, Metadata, User profile), and Data handler (Transmission control). Arrows show data flow between components across layers. + +F.740.9(25) + +**Figure I.5 – End-to-end architecture of thin client VR service model** + +#### The hardware layer + +- The "terminal hardware" refers to the computing, display, and audio capabilities of VR terminals, where the display is presented with a composite of graphics generated by the client-side application layer. +- The "input hardware" refers to the capability of providing various signals to the VR terminal device, including functions such as remote control, keyboards, voice, head-tracking, and hand-tracking. + +#### The client-side application layer + +- The "view processing" encompasses functionalities related to the presentation and feedback of VR terminal devices, including visual playback, UI presentation, and auditory playback haptic feedback. +- The "data processing" is a middle processing function for the VR client. For the thick client model, the VR engine is the central processing hub and runs the game, receiving data from the data handler, and sending data to present the game and to communicate with the network components; for the thin client model, data handled by the application will be transmitted to the server-side application through this module. +- The "data handler" has the important task of processing all the telemetry from the end user, by picking up signals from the hand-tracker and head-tracker hardware. It is also responsible for picking up audio for player voice signals. + +#### The network layer + +- The network layer involves a content delivery system for streaming media transmission as well as IP networks for data transfer. + +#### The server-side application layer + +- The "data processing" is responsible for handling data from multiple client-side applications, and for managing the status of the application. The VR engine on the server-side is also + +important for keeping all end-users synchronized together. For the thin client model, it is necessary to use 3D rendering and audio-video encoding capabilities. The operational output of the server-side VR service is encoded into audio-video format, and subsequently delivered to the client-side application through the streamer component via unicast streaming. + +- The "data storage" contains information such as audio and video media, metadata, user profile, etc. +- The "data handler" is responsible for receiving data from the client side. + +## I.3 User cases of VR service based on IPTV architecture + +From the user's perspective, VR service application scenarios are divided according to the number of users and the number of terminal devices, which mainly include: + +- Single user with single/multiple device(s) scenario: a scenario where a single user uses a smart set-top box and a TV, or more than one smart device to access and interact with VR services. +- Multiple users with multiple devices scenario: a scenario in which multiple users use smart set-top boxes, televisions and more than one smart device to access and interact with VR services. + +#### I.3.1 Single user with single/multiple device(s) scenario + +In this scenario, the user operates the IPTV STB either through a remote control or utilizes other devices such as mobile devices or IPTV VR HMD, which can facilitate additional VR service applications. Different types of IPTV TDs can be found in the ITU-T H.72x series. Figure I.6 is provided as a reference for this scenario. + +![Diagram of the single user with multiple devices scenario. A user (User-A) is connected to a group of IPTV terminal devices (IPTV VR HMD, Remote control, STB, TV, Mobile devices) via a Home gateway, an IP-based network, and an IPTV system.](fc0735d325f0ebd9214171975c68a888_img.jpg) + +The diagram illustrates the 'Single user with multiple devices scenario'. On the left, a person icon labeled 'User-A' is shown. A dashed box labeled 'IPTV terminal devices' contains five icons: 'IPTV VR HMD', 'Remote control', 'STB' (Set-Top Box), 'TV', and 'Mobile devices'. A line connects 'User-A' to the 'Remote control' inside the box. Another line connects the 'STB' inside the box to a 'Home gateway' (house icon). The 'Home gateway' is connected to an 'IP-based network' (cloud with nodes icon), which is in turn connected to an 'IPTV system' (cloud with server icons icon). The text 'F.740.9(25)' is located in the bottom right corner of the diagram area. + +Diagram of the single user with multiple devices scenario. A user (User-A) is connected to a group of IPTV terminal devices (IPTV VR HMD, Remote control, STB, TV, Mobile devices) via a Home gateway, an IP-based network, and an IPTV system. + +**Figure I.6 – Single user with multiple devices scenario** + +#### I.3.2 Multiple users with multiple devices scenario + +This scenario illustrates multiple users from different families connecting to an IP-based network through their IPTV terminal devices (as referenced in clause I.3.1) to access the same IPTV VR services. Different types of IPTV TDs can be found in the ITU-T H.72x series. Figure I.7 is provided as a reference for this scenario. + +![Diagram showing multiple users (User-A, User-B) connected via IPTV terminal devices and home gateways to an IP-based network, which is connected to an IPTV system. The diagram includes icons for users, terminal devices, home gateways, an IP-based network cloud, and an IPTV system with servers.](692541e65db4dc852988ce77ebb60ce5_img.jpg) + +The diagram illustrates a scenario where multiple users, User-A and User-B, are connected to an IPTV system. Each user is associated with a group of 'IPTV terminal devices' (represented by a dashed box) and a 'Home gateway' (represented by a house icon). Arrows show the flow from the terminal devices to the home gateway, and then from the home gateway to an 'IP-based network' (represented by a cloud with nodes). From the IP-based network, an arrow points to an 'IPTV system' (represented by a cloud above three server icons). The text 'F.740.9(25)' is located in the bottom right corner of the diagram area. + +Diagram showing multiple users (User-A, User-B) connected via IPTV terminal devices and home gateways to an IP-based network, which is connected to an IPTV system. The diagram includes icons for users, terminal devices, home gateways, an IP-based network cloud, and an IPTV system with servers. + +**Figure I.7 – Multiple users with multiple devices scenario** + +# Bibliography + +- [b-ITU-T F.746.14] Recommendation ITU-T F.746.14 (2022), *Requirements and reference framework for cloud virtual reality systems.* +- [b-ITU-T M.1400] Recommendation ITU-T M.1400 (2015), *Designations for interconnections among operators' networks.* +- [b-ITU-T P.1320] Recommendation ITU-T P.1320 (2022), *Quality of experience assessment of extended reality meetings.* +- [b-ITU-T Q.1702] Recommendation ITU-T Q.1702 (2002), *Long-term vision of network aspects for systems beyond IMT-2000.* +- [b-ITU-T Y.3502] Recommendation ITU-T Y.3502 (2014), *Information technology – Cloud computing – Reference architecture.* +- [b-ITU-T Y-Suppl.5] ITU-T Y.1900-series Recommendations (2008) – *Supplement on IPTV service use cases.* + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git 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b/marked/F/T-REC-F.743-201911-I_PDF-E/raw.md @@ -0,0 +1,643 @@ + + +International Telecommunication Union + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**F.743** + +(11/2019) + +SERIES F: NON-TELEPHONE TELECOMMUNICATION +SERVICES + +Multimedia services + +--- + +**Requirements and service description for video +surveillance** + +Recommendation ITU-T F.743 + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) features a globe with a red lightning bolt striking across it, symbolizing global connectivity and telecommunications. The letters 'ITU' are prominently displayed in blue and red. + +ITU logo + +International +Telecommunication +Union + +# ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multdestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| MULTIMEDIA SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.743 + +## Requirements and service description for video surveillance + +## Summary + +The purpose of Recommendation ITU-T F.743 is to define a video surveillance system based on IP networks. The video surveillance system provides the display and storage of the video captured by multiple remote cameras over an IP network for multiple users. It also provides other functionalities such as remote control and alarming. This Recommendation provides the service description, a brief system model, service scenarios and requirements for the video surveillance service. The requirements for the video surveillance service are derived from the scenarios of different applications that a video surveillance service can support. Therefore, the service requirements meet the needs of different kinds of users and enables interoperability among video surveillance systems of different telecom operators and units of different vendors. + +This revision updates the title of this Recommendation, some technical content descriptions, and video surveillance system requirements in clause 8. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|------------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.743 | 2009-12-14 | 16 | 11.1002/1000/10615 | +| 2.0 | ITU-T F.743 (V2) | 2019-11-29 | 16 | 11.1002/1000/14102 | + +### Keywords + +Alarming, camera, IP remote control, video surveillance. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2019 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|--------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation ..... | 1 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Introduction..... | 2 | +| 7 Scenarios..... | 3 | +| 7.1 Real-time surveillance ..... | 3 | +| 7.2 Recording and alarming ..... | 5 | +| 7.3 Convergence of the VS service and other services ..... | 5 | +| 7.4 Virtual special subsystem/rented subsystem ..... | 7 | +| 8 Video surveillance system requirements ..... | 8 | +| 8.1 User requirements..... | 8 | +| 8.2 Service requirements ..... | 9 | +| 8.3 Security requirements ..... | 12 | +| 8.4 Network and control requirements ..... | 13 | +| 8.5 QoS and QoE requirements ..... | 14 | +| 8.6 Management requirements ..... | 14 | +| 8.7 Accounting, charging and billing requirements ..... | 16 | +| 8.8 Convergence with other service system requirements ..... | 16 | +| 8.9 Output capabilities requirements ..... | 16 | +| 8.10 Input capabilities requirements..... | 16 | +| 8.11 Accessibility requirements ..... | 16 | +| 8.12 General design requirements ..... | 17 | +| Bibliography..... | 18 | + + + +# Recommendation ITU-T F.743 + +## Requirements and service description for video surveillance + +# 1 Scope + +This Recommendation describes the system model, service scenarios and specific service requirements for video surveillance. It fits within the framework of multimedia services defined by [ITU-T F.700], [ITU-T F.701] and [ITU-T F.702]. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T F.700] Recommendation ITU-T F.700 (2000), *Framework Recommendation for multimedia services*. +- [ITU-T F.701] Recommendation ITU-T F.701 (2000), *Guideline Recommendation for identifying multimedia service requirements*. +- [ITU-T F.702] Recommendation ITU-T F.702 (1996), *Multimedia conference services*. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +None. + +### 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +- 3.2.1 closed user group:** An aggregation of some users within which each user can do some special operations with others, such as sharing resources. +- 3.2.2 customer unit:** A device located at the customer part of a video surveillance system and used to present multimedia information (such as audio, video, image, alarm signals, etc.) to the end user. +- 3.2.3 premises unit:** A device located at the remote part of a video surveillance system and used to capture multimedia information (such as audio, video, image, alarm signal, etc.) from a surveilled object. +- 3.2.4 surveilled object:** The target (such as site, human, and related environment) which is surveilled. +- 3.2.5 video surveillance system:** A telecommunication system focusing on video (but including audio) application technology, which is used to remotely capture multimedia (such as audio, video, image, alarm signals, etc.) and present them to the end user in a friendly manner, based on a managed broadband network with quality, security and reliability ensured. + +**3.2.6 video surveillance system ID:** An identifier that identifies or names a device or a user in a video surveillance system. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|-----------------------------------| +| CU | Customer Unit | +| DRM | Digital Rights Management | +| EPG | Electronic Programme Guide | +| GIS | Geographic Information System | +| GPS | Global Positioning System | +| IM | Instant Messaging | +| IPTV | Internet Protocol Television | +| PC | Personal Computer | +| PSTN | Public Switched Telephone Network | +| PTZ | Pan/Tilt/Zoom | +| PU | Premises Unit | +| QoE | Quality of Experience | +| QoS | Quality of Service | +| SMS | Short Message Service | +| VoD | Video on Demand | +| VS | Video Surveillance | +| VSS | Video Surveillance System | + +## 5 Conventions + +In this Recommendation: + +- The keywords "**is required to**" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. +- The keywords "**is recommended**" indicate a requirement which is recommended but which is not absolutely required. Thus this requirement need not be present to claim conformance. +- The keywords "**can optionally**" indicate an optional requirement which is permissible, without implying any sense of being recommended. This term is not intended to imply that the vendor's implementation must provide the option and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance to this Recommendation. + +# 6 Introduction + +Video surveillance (VS) can provide real-time surveilled video from one or more cameras possibly located in large, complex and spatially distributed regions; hence, users can monitor and analyze remote sites. Further, the surveilled video can be recorded for replaying. + +Video surveillance systems connect users and premises units with cameras and other assistant functions by various access networks. Surveilled media flow can be delivered to any specified user terminal. Users can get surveilled video in any place whenever accessible. + +The surveilled video is mainly delivered from surveilled sites or from a system platform to users in one direction; however, audio flow may be bidirectionally delivered for instant communication. + +Premises units can be remotely controlled for the purposes such as object detection and recognition. + +External alarm information can be directly introduced to the video surveillance platform or by the premises unit. The system may also generate alarm information as a result of automated intelligent analysis. All alarm information should be processed by the system in time with operations such as triggered recording, sending notice to users and so on. + +Figure 1 shows a simple video surveillance system (VSS) functional model. + +![Figure 1 – VSS model diagram](367926125450c2bc3f4bdca9d59a62ba_img.jpg) + +The diagram illustrates the functional model of a Video Surveillance System (VSS). At the top, a box labeled 'Surveilled object' has a dashed arrow pointing down to a box labeled 'PU' (Premises Unit). The 'PU' box is connected to a central 'VS platform' box by a double-headed arrow. The 'VS platform' box is connected to a 'GPS, GIS' box (enclosed in a dashed rectangle) by a double-headed arrow. To the left of the 'VS platform', there are two boxes, 'Alarm related systems' and 'Other systems', both enclosed in dashed rectangles. Each has a double-headed arrow connecting it to the 'VS platform'. Below the 'VS platform' is a box labeled 'CU' (Customer Unit), connected by a double-headed arrow. To the left of the 'CU' is a box labeled 'User', connected by a double-headed arrow. A dashed line connects the 'User' box to the 'Alarm related systems' box. A dashed line also connects the 'User' box to the 'PU' box. A dashed line also connects the 'User' box to the 'VS platform' box. A dashed line also connects the 'User' box to the 'CU' box. The label 'F.743(19)\_F01' is located in the bottom right corner of the diagram. + +Figure 1 – VSS model diagram + +**Figure 1 – VSS model** + +A video surveillance system consists of premises units (PUs), a VS platform and customer units (CUs). A PU is located at a surveilled site to collect video, audio, alarm signals and other information, which can be conveyed to the VS platform and is transmitted, delivered, stored or processed by the VS platform. VS service subscribers (or users) watch the video, control the PUs remotely, and receive alarm information via CUs wherever accessible. + +PUs and CUs can access the VS system via a fixed or a mobile network. + +A VS system may interwork with other systems or units such as alarm related systems, global positioning system (GPS), geographic information system (GIS), Internet protocol television (IPTV), video conference, public switched telephone network (PSTN), short message service (SMS), 4G/5G, e-mail, instant messaging (IM) systems, and so on. These systems are denoted by dashed rectangles in Figure 1. The alarm related systems can collect alarm signals and execute corresponding operations. + +## 7 Scenarios + +This clause describes typical service scenarios illustrating the video surveillance service and deriving its service requirements. + +### 7.1 Real-time surveillance + +#### 7.1.1 Scenario 1 + +Bob has subscribed to the VS service. Alice is Bob's wife. Bob, John and Smith are good friends. + +- Step 1: Bob logs into the VS system via his PC in his office. There is a camera list on the left side of the screen, which displays detailed information for each camera that Bob can access. On the right side of the screen, an electronic map of Bob's house is displayed, which can be zoomed in or zoomed out. Each camera is marked on this map. When Bob clicks a camera, a surveillance window which can be resized appears on the screen. There are also subtitles at the bottom of the surveillance window, displaying the current time, the name of the surveilled site and other information. +- Step 2: While watching the surveillance video, Bob can save the current view as a still picture or begin to record the video at any time. The system will prompt Bob when he runs out of storage. +- Step 3: Bob is not satisfied with the current position of the camera, so he clicks the direction buttons on the screen to pan/tilt/zoom (PTZ) the camera to meet his need. As Bob feels that some positions are used frequently, he saves them into the profile. Each of these positions is called a preset position. When a preset position is selected, the camera is panned/tilted/zoomed to that position. In addition, when Bob feels that the video is not bright enough, he turns on the auxiliary light near the camera by clicking the appropriate button on the screen. +- Step 4: Meanwhile, Alice is accessing the same camera via her mobile phone. Alice is enabled to operate the PTZ control of this camera remotely as well as Bob. However, since only one user at a time can pan/tilt/zoom the camera, and Bob is now operating the PTZ control, Alice can only watch the video rather than control the camera. When Bob stops controlling, Alice begins to control the camera in the manner as Bob did. +- Step 5: Bob, John and Smith want to share their cameras installed in their gardens, so they apply the VS system for a closed user group. Bob is the sponsor and organizer of this closed user group. After the group is created, Bob invites John and Smith to the group, and they accept Bob's invitation. Finally, they set their garden cameras "shared within closed user group". Now, they can mutually visit each other's garden cameras. +- Step 6: In order to acquaint the citizens with up-to-date traffic conditions, a number of public cameras are installed on the streets. People can visit those cameras via the VS system. One day, Bob decides to go out. He wants to watch the traffic conditions of some streets simultaneously to help him decide the best route. Bob selects the multi-window mode, and then the screen is divided into several non-overlapped windows, with each window displaying a certain surveillance video. At the same time, many other users are visiting the public cameras as well as Bob. Hence, there are a lot of cameras, and each one of them may be visited by many users simultaneously. +- Step 7: Bob wants to monitor 16 sites simultaneously. But he does not want each window to be too small, so he divides the screen into only four windows. In order not to select cameras continually, Bob decides to set his terminal to the "PATROL" mode. He selects a list of cameras, arranges them, and lets them enter the "PATROL" mode. As a result, the VS system automatically switches the current four surveillance windows to the subsequent four sites periodically and circularly. When Bob wants to watch the current sites for more time, he presses the "PAUSE PATROL" button. Then the system stops switching until Bob presses the "CONTINUE PATROL" button. + +#### 7.1.2 Scenario 2 + +Tom and his wife have to work in the office on Sunday; they leave their son at home alone. Their son is so young that they are worried about him. So Tom subscribed to the VS service in order to watch his son from anywhere. + +Step 1: The VS system collects video and audio from Tom's house and Tom can receive this data via his terminal in the office. Usually, only the audio streaming is requested because it requires less bandwidth. + +Step 2: The VS system will automatically detect abnormalities with the help of video and audio analysis, whereby video streaming is immediately requested in order to know what is happening. On one occasion the VS system detects Tom's son crying, then video streaming is immediately requested. + +Tom can know what his son is doing at any moment without having to constantly watch the monitoring screens. + +### **7.2 Recording and alarming** + +Camera c2 is enabled to receive alarm signals. It is accompanied with an infrared sensor and a smog sensor. + +The building where Bob resides is equipped with fire-extinguishing devices, which are connected to the VS system via standard interfaces. + +Step 1: Bob sets his camera c1 to "Time-triggered Recording" mode with the start and end time designated, and sets his cameras c2 to "Alarm-triggered Recording" mode with the recording duration designated. When it is time to start recording, the VS system starts recording from the c1 camera. When it is time to stop recording, the VS system stops recording from the c1 camera. + +Step 2: One day, there is no one in Bob's home. A candle is still burning due to Bob's carelessness. It is detected by the sensors related to camera c2. An alarm signal is transferred to the VS system. According to the information of camera c2, the VS system starts up the related fire-extinguisher to extinguish the burning candle. At the same time, an alarm message is sent to Bob via the mobile short message service. + +Step 3: The VS system provides various ways to search for recorded video according to start time, duration, surveilled sites and/or the types of recording, etc. Bob searches for the records which were triggered by the alarm within the last three days. One record is found as a result. + +Step 4: Bob chooses to watch the recorded video. It is very similar to watching a video on demand (VoD) programme. Besides the video, there is some detailed information on the screen such as the name of the surveilled object, recording start time, the kind of recording, etc. Bob can play in normal speed or fast forward/backward, pause, seek for specified position, stop, etc. Meanwhile, Bob's current action is written to the system log. + +### **7.3 Convergence of the VS service and other services** + +#### **7.3.1 Convergence of VS and sensor networks** + +Mike is an environment supervisor, and factory E is a chemical factory. In order to protect the environment when the factory is in operation, there are a number of sensors installed inside and around factory E. These sensors include: sewage detectors which detect pollutants in the rivers, polluted atmosphere detectors which detect pollutants in the atmosphere, and noise detectors which detect the noise near factory E. These sensors are connected to a sensor network, reporting polluting indices to the sensor network periodically. Each sensor is usually associated to a camera. + +Step 1: One day, the sensor network system detects that the river near factory E is polluted. It then sends an alarm signal to the VS system. Soon Mike receives alarm messages issued by the VS system via SMS, e-mail and/or telephone. + +Step 2: The camera near the sewage detector is automatically started up by the VS system. + +Step 3: On receipt of the alarm messages, Mike goes to the surveillance centre near his office. There is a big TV wall which is displaying the surveillance video of the polluted river. Mike monitors the video and takes the necessary action. + +Figure 2 illustrates this scenario. + +![Diagram of convergence of video surveillance and sensor networks](042733dc5e8e7f5f30b60adba3266cde_img.jpg) + +The diagram shows a 'VS system' box at the top left and a 'Sensor network' box at the top right. Below the VS system is a dashed box labeled 'Location' containing a 'Camera' (oval) and a 'Sensor' (rectangle). Below the Sensor network is another 'Sensor' (rectangle). Arrows indicate data flow: from the Camera to the VS system, from the Sensor in the Location box to the Sensor network, and from the external Sensor to the Sensor network. The label 'F.743(19)\_F02' is at the bottom right. + +Diagram of convergence of video surveillance and sensor networks + +**Figure 2 – Convergence of video surveillance and sensor networks** + +#### 7.3.2 Convergence of VS and multimedia conference + +Jack works in company A, and Bob works in company B. One day, company A and company B are in a multimedia conference. Jack and Bob are participants. There are two meeting rooms located in two different cities. The participants are negotiating a business contract. The conference system can communicate with the VS system. + +Step 1: In the meeting, Bob proposes to watch the production process and some sample products of company A. The chairman designates Jack as speaker, and the meeting room of company A now becomes active. Since Jack has subscribed to the extra VS service from the conference system, an additional VS user interface on Jack's terminal is displayed. Jack then selects the "Workshop" camera, and presses the "Switch to Surveillance" button. The screen switches to the surveillance video of the workshop of company A, meanwhile the voice is not affected. + +Step 2: The participants of company B watch the surveillance video carefully. Meanwhile, Bob remotely operates the PTZ control of the camera. In this way, the participants of company B get further understanding of company A. + +Step 3: Bob suggests stopping surveillance. So Jack closes the surveillance video and the screen switches to the video of the previous meeting room. + +Figure 3 illustrates this scenario. + +![Diagram of convergence of VS and multimedia conference](af6be343f0c0a8f155f965dcf337b8af_img.jpg) + +The diagram shows a 'VS system' box at the top left and a 'Video conference system' box at the top right. Below the VS system is a dashed box labeled 'Company A' containing a 'Camera' (oval) and 'Meeting room 1' (rectangle). To the right of Company A is 'Meeting room 2' (rectangle). Blue curved arrows show data flow: from the Camera to the VS system, from the VS system to the Video conference system, from the Video conference system to Meeting room 1, and from the Video conference system to Meeting room 2. The label 'F.743(19)\_F03' is at the bottom right. + +Diagram of convergence of VS and multimedia conference + +**Figure 3 – Convergence of VS and multimedia conference** + +#### 7.3.3 Convergence of VS and IPTV service + +Step 1: Bob is watching an IPTV program which introduces a scenic spot, and is attracted by the program. He wants some current information of the scenic spot, such as its weather and the number of visitors, to determine whether and when it is suitable for him to have a trip to this place. There is a "Press to Real-time Watch" button on the bottom right corner of the screen. When Bob presses the button, the TV screen switches to an electronic map of the scenic spot. Each surveilled area is marked on the map. Bob clicks one area on the map, and then real-time surveillance video appears on the screen. + +Step 2: Bob is not very satisfied with the current scenes. He wants to watch more scenes of this scenic spot in different seasons. He then enters into record-on-demand electronic programme guide (EPG). The EPG provides a list of the titles of the recorded video in different seasons. Bob selects and watches them one by one, and decides to travel there next summer. + +Step 3: Finally, Bob exits the surveillance window and continues watching the previous IPTV programme. + +Figure 4 illustrates this scenario. + +![Diagram illustrating the convergence of VS and IPTV service. A VS system is connected to two cameras and a Record unit. An IPTV system is connected to a Channel (1-6) and an IPTV user. Arrows show data flow: Camera to VS system, VS system to IPTV system, IPTV system to IPTV user, and IPTV system to VS system. A Record unit is connected to the VS system.](410562339ce067fdc6fa41940c118658_img.jpg) + +The diagram shows a 'VS system' box on the left connected to two 'Camera' ovals above it and a 'Record' box below it. A double-headed arrow connects the 'VS system' to an 'IPTV system' box on the right. Above the 'IPTV system' is a 'Channel' box with six numbered slots (1-6). An arrow points from the 'IPTV system' to an 'IPTV user' box below it. Curved arrows show data flow: a blue arrow from a camera to the VS system, a green arrow from the VS system to the IPTV system, a pink arrow from the IPTV system to the VS system, and another pink arrow from the IPTV system to the Channel box. The label 'F.743(19)\_F04' is in the bottom right. + +Diagram illustrating the convergence of VS and IPTV service. A VS system is connected to two cameras and a Record unit. An IPTV system is connected to a Channel (1-6) and an IPTV user. Arrows show data flow: Camera to VS system, VS system to IPTV system, IPTV system to IPTV user, and IPTV system to VS system. A Record unit is connected to the VS system. + +**Figure 4 – Convergence of VS and IPTV service** + +### 7.4 Virtual special subsystem/rented subsystem + +A virtual special subsystem is a logically closed subsystem of a VS system, with all its devices and channels logically shared exclusively by its users. + +Company A consists of the parent company named A0 and two subsidiary companies named A1 and A2. Andy, Bill and Carl work in A0, A1 and A2 respectively. + +The company wants to hire a subsystem from the VS service operator, to then administrate and maintain all services on its own, with no intervention from the service operator. + +Step 1: The VS service operator installs the cameras, establishes a virtual special subsystem and rents it to company A. Then company A assigns Andy as an administrator to administrate this subsystem. Andy then assigns some users to use the VS service. + +Step 2: Some time later, for the convenience of management, Andy logs into the management system and divides this subsystem into three independent subsystems which are administrated by Andy, Bill and Carl, respectively. Meanwhile, Andy becomes a super administrator who can manage all the three subsystems. This is illustrated in Figure 5. + +![Figure 5: Subsystem A is divided into three subsystems. The diagram shows a transition from a single 'Subsystem A' to three separate subsystems: 'A0', 'A1', and 'A2'. 'Subsystem A' is an oval with an arrow pointing to 'A0', 'A1', and 'A2'. 'A0' is an oval at the top, 'A1' is an oval at the bottom left, and 'A2' is an oval at the bottom right. 'Andy' is a stick figure pointing to 'A0'. 'Bill' is a stick figure pointing to 'A1'. 'Carl' is a stick figure pointing to 'A2'. The text 'F.743(19)_F05' is in the bottom right corner.](4801720824e4b5e2361a5564f91cfb70_img.jpg) + +Figure 5: Subsystem A is divided into three subsystems. The diagram shows a transition from a single 'Subsystem A' to three separate subsystems: 'A0', 'A1', and 'A2'. 'Subsystem A' is an oval with an arrow pointing to 'A0', 'A1', and 'A2'. 'A0' is an oval at the top, 'A1' is an oval at the bottom left, and 'A2' is an oval at the bottom right. 'Andy' is a stick figure pointing to 'A0'. 'Bill' is a stick figure pointing to 'A1'. 'Carl' is a stick figure pointing to 'A2'. The text 'F.743(19)\_F05' is in the bottom right corner. + +**Figure 5 – Subsystem A is divided into three subsystems** + +Step 3: The managers of company A find that it is not convenient for sharing information and communicating so far. So Andy associates the three subsystems to form a hierarchical structure as shown in Figure 6. The lower level subsystems (A1, A2) are controlled by the higher level subsystem (A0). + +![Figure 6: Hierarchical structure of the three subsystems. The diagram shows a hierarchical structure with 'A0' at the top, 'A1' at the bottom left, and 'A2' at the bottom right. 'A0' is an oval, 'A1' is an oval, and 'A2' is an oval. 'Andy' is a stick figure pointing to 'A0'. 'Bill' is a stick figure pointing to 'A1'. 'Carl' is a stick figure pointing to 'A2'. Solid lines connect 'A0' to 'A1' and 'A0' to 'A2'. The text 'F.743(19)_F06' is in the bottom right corner.](a33da0f14e456f92539ce3e9b7d81f9a_img.jpg) + +Figure 6: Hierarchical structure of the three subsystems. The diagram shows a hierarchical structure with 'A0' at the top, 'A1' at the bottom left, and 'A2' at the bottom right. 'A0' is an oval, 'A1' is an oval, and 'A2' is an oval. 'Andy' is a stick figure pointing to 'A0'. 'Bill' is a stick figure pointing to 'A1'. 'Carl' is a stick figure pointing to 'A2'. Solid lines connect 'A0' to 'A1' and 'A0' to 'A2'. The text 'F.743(19)\_F06' is in the bottom right corner. + +**Figure 6 – Hierarchical structure of the three subsystems** + +Step 4: (Now Andy, Bill and Carl are looked upon as common users rather than the administrators.) Andy logs in, watches the surveillance video of either A0 or A1/A2 successfully. Bill watches the surveillance video of A1 successfully, but he fails to watch the video of A0. + +Step 5: In subsystem A0, an alarm message is issued for some reason and sent to Andy, but Bill and Carl do not receive it. + +Step 6: In subsystem A1, an alarm message is issued for some reason and sent to Bill. It is also sent to Andy. + +## 8 Video surveillance system requirements + +### 8.1 User requirements + +#### 8.1.1 User level requirements + +– USR-001: A VS system is recommended to classify users into several levels. Users of different levels have different operational rights; high-level users have more operation privileges than low-level ones. Low-level users can do basic operations which meet the following basic requirements, and high-level users can do advanced operations which meet the following advanced requirements. For example, users of level 1 can only watch + +real-time video, while users of level 2 can control the PUs remotely as well as watch real-time video. + +#### **8.1.2 Basic requirements** + +- USR-002: A VS system is required to support registration and de-registration of the end user through the interface provided by the platform, and whereby the end user can view and modify personal information. +- USR-003: A VS system is required to support end-user login and logout from the VS platform conveniently. The user name and password are required when an end user logs into the system. +- USR-004: A VS system is recommended to support end-user view of the user access logs or other system logs. +- USR-005: A VS system is required to support end-user view of the PU's information via the CU, including name, status, capabilities, location and other information of the PU. +- USR-006: A VS system is required to support CU's capability for description and negotiation, such as the decoding capability set by the end user. +- USR-007: A VS system is required to support the presentation of the real-time video captured by the PU for end users. +- USR-008: A VS system is required to support end users to order and cancel different services, including basic services and value-added services. The VS system is also required to support end users to view the personal account information and operation logs conveniently. + +#### **8.1.3 Advanced requirements** + +- USR-009: A VS system is recommended to simultaneously present the video of different channels, captured by different PUs, to the end user via CUs. The number of connected channels is recommended to be modified within a specified range. The VS system is recommended to support adjusting picture resolution, quality level, transmission rate and other parameters of each channel by the end user. +- USR-010: A VS system is recommended to support panning, tilting or zooming (i.e., PTZ) the PU by the end user. The restriction is that one PU can only be controlled by one end user at a time. +- USR-011: A VS system is recommended to support searching recorded video by diverse means, presenting the recorded video of different channels, and controlling various playing operations by the end user. +- USR-012: A VS system is recommended to support sending alarm messages via CU and/or other related terminals to end users in cases of alarm events. +- USR-013: A VS system is recommended to support remote control over PU (e.g., locking/unlocking, enabling/disabling, etc.) by end users. + +### **8.2 Service requirements** + +#### **8.2.1 Basic requirements** + +- SRV-001: A VS system is required to support registration and de-registration of the device through the interface provided by the platform. In case the device fails to register, it should register again after a random time interval. +- SRV-002: A VS system is recommended to support peer-to-peer real-time video transfer directly from a PU to CU. + +- SRV-003: A VS system is required to support real-time video transfer from one PU to multiple CUs. +- SRV-004: A VS system is required to support real-time video transfer from multiple PUs to one CU. +- SRV-005: A VS system is recommended to support collecting the video from multiple channels and then transmitting it to multiple CUs. +- SRV-006: A VS system is recommended to receive status and alarm information of PUs and CUs, and support terminals status management. +- SRV-007: A VS system is recommended to support remote PTZ control over PU by end users via a CU or by the platform. The PTZ control should be compliant with end user's privileges. +- SRV-008: A VS system is recommended to provide alarm and linkage action functions, which can be used to respond to an input alarm signal event by producing an output alarm activity that triggers the related linkage actions. Both the input of outer alarm signals and video motion detections which trigger alarm signals are recommended to be supported. +- SRV-009: A VS system is required to support device information query. It can be used to obtain the directory information and status information of the registered devices in the network system, wherein the directory information includes device ID, device name, device manufacturer name, device model, device address, device password, device type, device status, device mounting address, device owner, parent device ID, etc. +- SRV-010: A VS system is required to support system status information reporting. The platform can collect and report the operating status information of monitoring devices, alarm devices and other relevant components. +- SRV-011: The time synchronization mechanism is required to be supported, which will synchronize the clocks of all devices/units of the VS system. + +#### 8.2.2 Advanced requirements + +- SRV-012: A VS system is required to support audio acquisition surveillance. Audio is required to be provided with video or provided separately if necessary. +- SRV-013: A VS system is recommended to provide audio communication between a PU and a CU, which can be triggered by manual mode (according to the command of administrator, operator and/or surveillant). Both unidirectional voice communication mode and bidirectional voice communication mode are recommended to be supported. The former provides one-way communication from the customer/CU to the surveilled object/PU (e.g., speech/audio broadcasting) and the latter provides bidirectional, simultaneous communication both from the customer/CU to the surveilled object/PU, and from the surveilled object/PU to the customer/CU (e.g., talkback). +- SRV-014: A VS system can optionally provide preset positions of pans and lenses of PUs. A preset position is set by the end user or by the system in advance. The pans can rotate and the lens can be zoomed to the preset position with a single operation. +- SRV-015: A VS system is recommended to support controlling wipers, fan and auxiliary lamps of PUs remotely. +- SRV-016: A VS system is required to support the capability of recording, which can be triggered by time and/or alarm signals, or be manually turned on by users. In addition, a VS system is required to record for extra specified time before triggering events occur. +- SRV-017: A VS system is required to provide the capability of record searching by a variety of means. The recorded video is recommended to be searched by start time and stop time, duration of recording, or names of surveilled sites, etc. + +- SRV-018: A VS system is required to provide the function of playing record, and provide the control functions of playing, such as fast playing, fast rewinding, pausing, locating, stopping, and so on. +- SRV-019: A VS system is required to support time-shift play. +- SRV-020: A VS system is required to support the download of historical video and audio files in a specific device within a specified time period. +- SRV-021: A VS system is required to support video record management. The locations and spaces of the storage can be specified, and the storage mechanism is required to be efficient and flexible. Extended storage devices can optionally be connected to the platform to enlarge the total storage space of the system. +- SRV-022: A VS system is required to provide recording logs. +- SRV-023: When an alarm signal is received, the platform is required to start recording for related PUs, and display this alarm information on related CUs. +- SRV-024: A VS system can optionally provide electronic maps with PUs marked and displayed on the maps. +- SRV-025: A VS system can optionally provide intelligent image identification, including number plate identification, face identification, motion target identification and tracking, etc. Alarm signals can optionally result from the intelligent identification. Additionally, more information can optionally be obtained by means of image identification technologies, which would result in new value-added applications in the future. +- SRV-026: A VS system is required to allow end users to deploy their PUs themselves. For example, enterprise users can optionally deploy PUs by themselves, and then the PUs would access the VS network of VS service provider. +- SRV-027: A VS system can optionally consist of multiple domains. A domain is a subsystem of the VS system physically or virtually. Each domain is a fully-functional subsystem. It can interwork with others, and is required to support the hierarchical structure. Each subsystem is a complete VS system. A lower level subsystem can be managed and controlled by its higher level parent subsystem. +- SRV-028: A VS system is required to support virtual special subsystems. A physical VS system or subsystem could be divided dynamically into various virtual special subsystems. Virtual special subsystems could also be created, adjusted, configured or removed dynamically. Like multiple domains mentioned above, virtual special subsystems also support the hierarchical structure. +- SRV-029: A VS system is recommended to support functions of instant image snapshot and the relevant image storage. An end user can search, view and manage the recorded and stored snapshot images. +- SRV-030: The instant image snapshot function can optionally be triggered in manual mode (i.e., according to the commands of the operator) and automatic mode (i.e., according to preset configuration conditions such as time, alarm and policy parameters). +- SRV-031: The real-time video surveillance function is recommended to support the capabilities of multi-picture surveillance, multi-screen display, multi-screen alternation (e.g., auto-patrol), caption overlay, and designated-area-shielding. +- SRV-032: A VS system is recommended to support the capability of containing the detailed information for each recorded media segment, which includes the surveilled location, the recording start time, the reason why the recording triggered, etc. +- SRV-033: A VS system can optionally provide playback logs and the relevant statistics information. + +- SRV-034: A VS system is required to support subscription and notification mechanisms, including event and device directory subscription and notification. + +#### **8.2.3 Interworking with other service systems requirements** + +- SRV-035: A VS system is required to get alarm signals from alarm input devices or systems. +- SRV-036: A VS system is required to send alarm messages to end users by various means such as telephone, e-mail, SMS, instant message, etc., and inform the alarm output devices/systems to execute the corresponding operations in case of alarm events. +- SRV-037: A VS system can optionally support retrieving data information of electronic maps from an external GIS service. +- SRV-038: A VS system can optionally support retrieving location information of the PUs from the external GPS service. + +### **8.3 Security requirements** + +#### **8.3.1 Authentication security requirements** + +- SEC-001: A VS system is required to provide the mechanisms for authentication and authorization; it is required to only permit authorized users to access the system and use applications. A VS system is required to forbid an unauthorized user to handle any resource of the system. +- SEC-002: A VS system is required to provide uniform identification to all devices that get access to the system. The accessing devices identification is required to adopt different authentication methods according to different conditions. Under the application conditions of low-security level, the devices shall be authenticated with the password-based digital abstract authentication method. + +#### **8.3.2 Access security requirements** + +- SEC-003: A VS system is required to ensure the security of accessing and controlling PUs. Each PU has access attributes. Only authorized users can access PUs. The types of access include real-time surveillance, replaying the recorded video, remote controlling and so on. An end user can access a PU according to his/her access privilege of the PU. +- SEC-004: A VS system is required to ensure the security of resources such as recorded video, digital maps, etc. +- SEC-005: A VS system is required to be able to operate in environments where NAT and/or firewall devices are present at either or both ends between two communicating entities. It is recommended to utilize the specified firewall, gatekeeper and other network devices to ensure the security to access to some special video surveillance services. + +#### **8.3.3 Content security requirements** + +- SEC-006: A VS system is recommended to ensure the security of media stream delivery. It is required to provide security mechanisms, such as video encryption for the media stream, to ensure the integrity and secrecy of the video stream. +- SEC-007: A VS system is recommended to provide hop-by-hop security encryption of messages on the network layer or the transport layer under the application conditions of high-security level. The end-to-end encryption is recommended to be applied to the application layer, and the session key should be encrypted in the transport process. The transmission content shall be encrypted. Under the application conditions of high-security level, the data storage should be encrypted. + +- SEC-008: A VS system is recommended to prevent the information integrity from being damaged, with such technologies as digital digest, digital timestamp and digital watermarking, namely, avoiding malicious tampering of the system data. +- SEC-009: A VS system is required to ensure the security of the recorded video. It is required to provide the mechanisms to protect the copyrights of the recorded video, and to protect the video from being juggled. +- SEC-010: A VS system is required to protect user privacy. + +#### **8.3.4 System security requirements** + +- SEC-011: A VS system is required to have the capability of resisting vicious attacks. +- SEC-012: A VS system is required to provide the mechanisms for troubleshooting and data backup. It is required that a structural single-node problem be avoided (i.e., a problem at a node should not cause failure of the whole system). + +#### **8.3.5 Network security requirements** + +- SEC-013: The bearer network is recommended to provide network transmission for the video surveillance service with high availability and high reliability. +- SEC-014: The bearer network is required to provide end-to-end security for media transport and signalling exchange. +- SEC-015: The bearer network is recommended to provide the capability of rapid error detection, fault-location and failure-recovery. +- SEC-016: Bearer network recovery is recommended to provide the capabilities for discovering and defending aggressive behaviour or traffic from network attacks. +- SEC-017: The bearer network is recommended to provide the confidentiality for information transmission if required. +- SEC-018: A VS system is recommended to support the capability for enhancing session security when the underlying network cannot provide an appropriate level security capability. +- SEC-019: A VS system is recommended to utilize the appropriate security mechanism (e.g., DRM and watermarking) for media storage. + +### **8.4 Network and control requirements** + +- NET-001: PUs and CUs are required to access the VS network via a packet-switched network, i.e., an IP-based bearer network, such as LAN, WLAN, xDSL, GPRS, CDMA 1x, and so on. +- NET-002: The network is required to transmit service data accurately in real time, and to have multicast capability. End-to-end QoS is required to be guaranteed to deploy the real-time VS system over an IP network. The network is required to provide low delay, low jitter and low packet loss rate to transmit the audio/video stream. +- NET-003: The network bandwidth design of the network system is required to meet the bandwidth requirements of the PU accessing to the surveillance centre, interconnection network of surveillance centres and CUs accessing the surveillance centre. +- NET-004: Control signals and media data are required to be transported in different channels. Control signals are required to be transported in real time and accurately, and the bandwidth of control signals is required to be as low as possible. +- NET-005: The audio/video media data is required to be transported from the source to the destination quickly and effectively. The system is required to choose an appropriate mechanism of media control and distribution automatically depending on the network environment and user requirements. + +- NET-006: Every PU has location information, which can optionally be automatically retrieved through the GPS system or set by an administrator. Each device of the VS system has a unique identification number. IP address and location of a device can optionally be obtained according to the identification number. +- NET-007: To authorize a user, a unique identification number for the authorized user is required to be assigned and accompanied with other necessary information. The number is required to be used as the destination indication when the end user is called, and as the identifier for accounting. +- NET-008: A VS system is required to support the mobility and nomadism for CU and/or PU, if necessary. +- NET-009: A VS system is required to support both unicast and multicast capabilities for media transmission. + +### 8.5 QoS and QoE requirements + +- QoS-001: The quality of service (QoS) strategies are recommended to be implemented on the service layer or on the bearer network layer, or both. In cases of delay, jitter, sequence error and packet loss, the service layer is required to be able to recover and repair the impairments, and adjust the data stream in response to the changes of the network bandwidth. +- QoS-002: A VS system is required to provide good quality audio and video media. When the real-time video or the recorded video is played, the pictures and the voice are required to be clear and fluent, and the audio and video media are required to be synchronized. +- QoS-003: The end-to-end information delay time (including the time taken by the information acquisition, encoding and network transmission processes at the sending end as well as the decoding and display processes at the information receiving end) is required to be as low as possible when information (including video and audio information, control information and alarm messages) is transmitted through the IP network. +- QoS-004: The maximum video frame rate of the VS system is recommended to be no lower than 25 frames/s. +- QoS-005: The connection establishment time between CU and PU is required to be reasonable. +- QoS-006: The switching time from one surveillance channel to another one is required to be reasonable. +- QoS-007: A VS system is required to respond rapidly to the user's operation. +- QoS-008: A VS system is required to provide enough storage space for recording video. +- QoS-009: In cases of alarm events, response time is required to be short enough to ensure the events to be processed in time. + +### 8.6 Management requirements + +#### 8.6.1 Terminal management requirements + +- MAN-001: A VS system is recommended to manage registration/de-registration, authentication, version upgrade, grouping, connection and troubleshooting of the VS terminal devices (such as CUs and PUs). +- MAN-002: A VS system is recommended to support configuration and management for all devices in the VS system including platform and terminal devices, such as capability parameters, device-performance parameters and service-related properties configuration, status control and monitoring (i.e., PU activation and deactivation). A VS system is required to support input and output of device configuration data. + +#### **8.6.2 Network management requirements** + +- MAN-003: A VS system is recommended to support remote configuration management, accounting management, performance management, capability management, status detection, trouble alarm management and security management for the VS network equipment (such as router, switch and various servers) and resources (such as bandwidth). The management privilege is required to be divided into different levels. + +#### **8.6.3 Service management requirements** + +- MAN-004: A VS system is recommended to provide management of service resource, signalling control and system running state diagnostics of VS. Service management functions include service resource control, service configuration, session status monitoring, signalling tracing, system running status diagnostics and system optimization. +- MAN-005: A VS system is required to provide various subscription means for users, and to provide the capabilities of querying, viewing and modifying their subscription information. +- MAN-006: A VS system is recommended to provide various alternative accounting modes, and to support the flexible combinations of payment mode, billing mode, billing cycle, preferential price, etc. + +#### **8.6.4 Media resource management requirements** + +- MAN-007: A VS system is required to support the management of the captured and recorded VS media resource. Media resource management functions include media session information statistics, media distribution information updating/publishing, media usage information statistics, media adding/updating, media storage/archiving, media indexing/search, media play/playback, media edition/modification, media copy/backup, media expiration/deletion. +- MAN-008: A VS system is required to provide different query levels for contents. Only administrators who meet the query level requirement can view specific media contents. + +#### **8.6.5 Signal tracing management requirements** + +- MAN-009: A VS system is recommended to provide two models of signal tracing: one is to track user behaviour, and the other is to track the signal flow and process inside the service platform. A VS system sends commands to the terminals to indicate that the terminals send back a signal record for a specific performance to trace a user's behaviour. The signal flow inside the service platform are recommended to be observed directly through the VS system to trace internal signal flow, not only the flow track but also the signal content. + +#### **8.6.6 Alert and notification management requirements** + +- MAN-010: A VS system is recommended to support alert collection, process, presenting, report and regulation management for all the devices within the entire system. +- MAN-011: A VS system is recommended to support various means of alert processing including alert filtering, confirmation, elimination, synchronization, alert-level promotion, etc. It also supports the alert information forwarding by e-mail, SMS, etc. +- MAN-012: A VS system is recommended to support presenting new alert messages by voice and light. Voice presence is to notify customers of the availability of a new alert message, as well as the alert level through voice signal. Light presence is to notify customers about a new alert message available by changing colour or flickering the icon or text in the topological graph. +- MAN-013: A VS system is recommended to support search and statistics for current and historic alert information record. +- MAN-014: A VS system is recommended to support redefining the alert level, alert filtering, etc. + +#### **8.6.7 Performance measurement requirements** + +- MAN-015: A VS system is recommended to provide device performance monitoring and analysis. According to the performance data collected from devices in the system, the VS system processes and generates performance reports in order to provide information for maintenance and management personnel, indicating the system deployment, design and modification, and improving the QoS of the VS service. + +### **8.7 Accounting, charging and billing requirements** + +- ACB-001: A VS system is recommended to provide the capability of accounting, charging and billing for the service operation. +- ACB-002: A VS system is recommended to provide the interfaces among the functional entities for accounting, charging and billing functions. + +### **8.8 Convergence with other service system requirements** + +- CON-001: A VS system is recommended to provide the convergence capabilities and interworking interfaces for IPTV, videoconferencing, etc. + +### **8.9 Output capabilities requirements** + +Video surveillance systems should provide data output capabilities for other services that can use video surveillance system resources. Thus, other services can be considered as external services to the video surveillance service itself. + +- OCR-001: A VS system is required to assign a unique VSS ID to each internal system resource. This ID can be used by other services. Each media resource is required to have some attributes to indicate whether or not this resource is real-time video, and any other necessary system features. +- OCR-002: A VS system can optionally output media streams from its library of system resources according to specified VSS IDs, where the encoding format of the media can be designated by external systems. +- OCR-003: A VS system is required to provide the specified system resource only to the authorized external systems. +- OCR-004: A VS system can optionally inform the alarm information to external systems. + +### **8.10 Input capabilities requirements** + +Video surveillance systems can optionally provide data input capabilities whereby they can receive input information from other systems. + +- ICR-001: A VS system can optionally get the resulting analyzed information input from an external system with intelligent analysis capability. +- ICR-002: A VS system can optionally get alarm signals from external alarm devices or systems. +- ICR-003: A VS system can optionally get additional media information input from an external system for a specified system resource, using the VSS ID as identifier. + +### **8.11 Accessibility requirements** + +- ACS-001: CUs are recommended to be controllable through as many alternative forms of user interface interaction as possible. Similarly, the user interface feedback should be configurable to utilize as many forms of feedback as possible. +- ACS-002: A VS system is recommended to provide external and, possibly, internal interfaces that can handle device control, service control and media capture/rendering. + +- ACS-003: A VS system is recommended to send alarm information by using different forms of media. It is recommended to send multimedia alarm information other than single-media alarm information. +- ACS-004: A VS system is recommended to provide configurable media properties, e.g., bit rate and frame rate, for both media transport and media presentation to meet accessibility requirements. +- ACS-005: A VS system is recommended to provide adjustable text display characteristics to meet the needs of users when text information is displayed. For example, the font and/or the size of the text may be adjustable. +- ACS-006: A VS system is recommended to include alternative ways to receive feedback from the control actions of CUs or service, using various modes and properties of presentation. + +### **8.12 General design requirements** + +- GEN-001: The VS system architecture is recommended to support the hierarchical system design and deployment model in order to support flexibility and extensibility. +- GEN-002: The VS system architecture is recommended to be flexible and extensible enough to allow for unanticipated future requirements and integrate some more subsystems or other related external systems seamlessly. +- GEN-003: A VS system is required to assign the unique identity for CUs, PUs and other devices, and the relevant coding rules for identification are recommended to support the extensibility and uniqueness accordingly. +- GEN-004: A VS system is required to support the indication and negotiation of the media coding formats (e.g., the audio codec, video codec and media file formats) between CU and head-end (e.g., PU and/or media server). +- GEN-005: The VS system core functions are required to comprise: real-time video surveillance, PTZ control, alarming and linkage actions, recording, playback, instant image snapshot, audio acquisition and voice communication. +- GEN-006: The VS system design is recommended to use the hierarchical structure, and the communications between modules are recommended to use standard interfaces. The design, maintenance and updating of any modules as well as additional new modules are recommended not to affect other modules. +- GEN-007: The VS system design is recommended to support the capability of system parameters and user data. The system parameters, user data and their processing procedures are recommended to be relatively independent, in order to facilitate system maintenance and extension. +- GEN-008: The VS system architecture is recommended to support distributed structure as well as centralized structure. +- GEN-009: A VS system is recommended to provide a complete secondary development tool and user guide (such as SDK and APIs function description) to facilitate customization work. + +## Bibliography + +- [b-ITU-T H.Sup.1] ITU-T H-series Recommendations – Supplement 1 (1999), *Application profile – Sign language and lip-reading real-time conversation using low bit rate video communication.* + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.743.10-201911-I_PDF-E/1d7527f4316cfe2d342b08d1653d1592_img.jpg b/marked/F/T-REC-F.743.10-201911-I_PDF-E/1d7527f4316cfe2d342b08d1653d1592_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..9002ee68e2b9ebf63d27d39ba8c73bdafb0e6be6 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a/marked/F/T-REC-F.743.10-201911-I_PDF-E/raw.md b/marked/F/T-REC-F.743.10-201911-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..65f3e1cefc116d7339772b2684b7d83a0e846ac7 --- /dev/null +++ b/marked/F/T-REC-F.743.10-201911-I_PDF-E/raw.md @@ -0,0 +1,460 @@ + + +International Telecommunication Union + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**F.743.10** + +(11/2019) + +SERIES F: NON-TELEPHONE TELECOMMUNICATION +SERVICES + +Multimedia services + +--- + +**Requirements for mobile edge computing- +enabled content delivery networks** + +Recommendation ITU-T F.743.10 + +ITU-T + +![ITU logo](1d7527f4316cfe2d342b08d1653d1592_img.jpg) + +The logo of the International Telecommunication Union (ITU) features a stylized globe with a red lightning bolt striking across it. The letters "ITU" are prominently displayed in blue and white. + +ITU logo + +International +Telecommunication +Union + +# ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multdestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| MULTIMEDIA SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.743.10 + +## Requirements for mobile edge computing-enabled content delivery networks + +## Summary + +Recommendation ITU-T F.743.10 specifies the general framework, scenarios and requirements for mobile edge computing- (MEC-)enabled content delivery networks (CDNs). Recommendation ITU-T F.743.10 also specifies the requirements for MEC functions on which a CDN edge node relies. The deployment of a CDN edge node with an MEC system is described in the general framework. Several use cases are introduced in Recommendation ITU-T F.743.10 to illustrate the usage of MEC-enabled CDN. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.743.10 | 2019-11-29 | 16 | 11.1002/1000/14103 | + +## Keywords + +MEC-enabled CDN, mobile edge CDN, mobile edge computing. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2020 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-----------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 2 | +| 6 Introduction..... | 2 | +| 7 MEC-enabled CDN scenarios..... | 3 | +| 7.1 Hot content caching locally ..... | 3 | +| 7.2 VR/AR..... | 4 | +| 7.3 Live video ..... | 5 | +| 8 Requirements for MEC-enabled CDN..... | 7 | +| 8.1 CDN service requirements ..... | 7 | +| 8.2 MEC functional requirements ..... | 8 | +| 8.3 Security..... | 9 | +| 8.4 Charging ..... | 9 | +| Bibliography..... | 10 | + + + +# Recommendation ITU-T F.743.10 + +## Requirements for mobile edge computing-enabled content delivery networks + +## 1 Scope + +This Recommendation specifies requirements and offers a general framework for mobile edge computing- (MEC-) enabled content delivery networks (CDNs), as well as several application scenarios to illustrate their effectiveness. Requirements include those for CDN service, MEC function, security and charging. + +## 2 References + +None. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +None. + +### 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 mobile edge computing:** System which provides an IT service environment and cloud-computing capabilities at the edge of an access network which contains one or more type of access technology, and in close proximity to devices. + +NOTE – Based on the definition of multi-access edge computing in [b-ETSI GS MEC 001]. + +**3.2.2 mobile edge computing-enabled content delivery network:** A content delivery network (CDN) enhanced by mobile edge computing (MEC), which is able to provide distribution and delivery service at the edge of the network. An MEC-enabled CDN can be composed of a conventional CDN node and a mobile edge CDN node. + +**3.2.3 mobile edge content delivery network:** A group of content delivery network nodes, which is deployed locally on a mobile edge computing host, which can provide content delivery service to users on the edge of a mobile network. + +**3.2.4 mobile edge content delivery network instance:** A mobile edge content delivery network node, which is instantiated in mobile edge computing system as an application. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|-------------------------------| +| 3D | Three Dimensional | +| AR | Augmented Reality | +| API | Application Program Interface | +| App | Application | +| CDN | Content Delivery Network | +| DNS | Domain Name System | +| FQDN | Fully Qualified Domain Name | + +| | | +|------|-----------------------------------| +| GSLB | Global Server Load Balance | +| IP | Internet Protocol | +| IT | Information Technology | +| MEC | Mobile Edge Computing | +| QoE | Quality of Experience | +| RNIS | Radio Network Information Service | +| RTT | Round-Trip Time | +| UE | User Equipment | +| VCR | Video Cassette Recorder | +| VR | Virtual Reality | + +## 5 Conventions + +In this Recommendation: + +The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. + +The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement needs not be present to claim conformance. + +The keywords "can optionally" and "may" indicate an optional requirement which is permissible, without implying any sense of being recommended. These terms are not intended to imply that the vendor's implementation must provide the option and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the specification. + +## 6 Introduction + +CDN is built for serving content to users in a transparent and efficient way, by which, the quality of experience (QoE) of mobile users is guaranteed with optimized availability and performance. Nowadays, rapid growing high-resolution video-related services and interactive content, such as 4K/8K video formats and (virtual reality/augmented reality (VR/AR), require lower latency and higher throughput from the network. However, considerable latency and a bandwidth availability bottleneck exist in a mobile backhaul network when CDN is highly deployed on a backbone or metro network. + +MEC-enabled CDN refers to a CDN including conventional CDN and mobile edge CDN. The general framework of a MEC-enabled CDN is shown in Figure 6-1. + +![Figure 6-1: The general framework of MEC-enabled CDN. The diagram illustrates the architecture of an MEC-enabled CDN. At the top, a dashed red box labeled 'MEC enabled CDN' contains a 'Conventional CDN' (represented by three server icons) and a 'CDN manager'. This is connected to a 'Mobile core network' (represented by a cloud with a circular arrow icon). Above the mobile core network is a 'MEC manager' (blue box). Below the mobile core network is an 'MEC system' (dashed blue box) containing a 'Mobile edge CDN' (blue box), a 'Hardware platform' (blue box), and a 'MEC host' (blue box). The MEC host is connected to a 'Base station' (radio tower icon), which is in turn connected to a 'UE' (User Equipment, smartphone icon). A green line represents 'Mobile traffic' flowing from the UE through the Base station, MEC host, and Mobile edge CDN. A red dashed line represents 'Pull/push caching' traffic flowing from the Conventional CDN, through the Mobile core network, to the Mobile edge CDN. A legend at the bottom right identifies the green line as 'Mobile traffic' and the red dashed line as 'Pull/push caching'. The text 'F.743.10(19)_F6-1' is visible in the bottom right corner of the diagram area.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +Figure 6-1: The general framework of MEC-enabled CDN. The diagram illustrates the architecture of an MEC-enabled CDN. At the top, a dashed red box labeled 'MEC enabled CDN' contains a 'Conventional CDN' (represented by three server icons) and a 'CDN manager'. This is connected to a 'Mobile core network' (represented by a cloud with a circular arrow icon). Above the mobile core network is a 'MEC manager' (blue box). Below the mobile core network is an 'MEC system' (dashed blue box) containing a 'Mobile edge CDN' (blue box), a 'Hardware platform' (blue box), and a 'MEC host' (blue box). The MEC host is connected to a 'Base station' (radio tower icon), which is in turn connected to a 'UE' (User Equipment, smartphone icon). A green line represents 'Mobile traffic' flowing from the UE through the Base station, MEC host, and Mobile edge CDN. A red dashed line represents 'Pull/push caching' traffic flowing from the Conventional CDN, through the Mobile core network, to the Mobile edge CDN. A legend at the bottom right identifies the green line as 'Mobile traffic' and the red dashed line as 'Pull/push caching'. The text 'F.743.10(19)\_F6-1' is visible in the bottom right corner of the diagram area. + +**Figure 6-1 – The general framework of MEC-enabled CDN** + +MEC is proposed for migrating computation, storage and service capability to the network edge. It is considered to be a promising technology for establishing mobile edge CDN due to its traffic routing ability and cloud computing or information technology (IT) service environment. An MEC system consists of a MEC host and MEC manager, in which a mobile edge CDN node is deployed and instantiated as a MEC application (app) [b-ETSI GS MEC 003]. + +Through the MEC manager, related mobile edge CDN network service files and software can be downloaded to and validated by an MEC host for further instantiation and deployment, as well as other management functionalities, such as life cycle management. + +By utilizing MEC, mobile edge CDN nodes can be deployed locally in a distributed way (e.g., collocated with base station) and should be able to interact with conventional CDN nodes for pull caching and push caching. + +This Recommendation describes scenarios and requirements of MEC-enabled CDN. + +## 7 MEC-enabled CDN scenarios + +This clause describes various scenarios for MEC-enabled CDN. + +### 7.1 Hot content caching locally + +Because of the wide adoption of social media, a large number of users within a geographical area, such as a campus, enterprise or residential area, may request the same hot content in a given period of time, including news, music and videos. This puts tremendous pressure on the backhaul bandwidth of a mobile network and leads to a poor QoE for users. + +This problem can be alleviated by MEC-enabled CDN with cloud-computing capabilities and an IT service environment provided by MEC; see Figure 7-1. In mobile edge CDN, the most popular content can be stored at the edge of a mobile network (e.g., collocated with a base station) and consumed in the local area. Once requested, the hot content can be sent to users from the edge of a mobile network with high quality and low latency. In that case, there is no need to transfer content over a mobile core network from the conventional CDN. The mechanism of hot content selection shall be predefined or dynamically updated to fulfil the request of the user. + +Therefore, by deploying MEC-enabled CDN, the backhaul occupation of a mobile network can be saved and the QoE of users improved as content is transferred without additional delays from the mobile core network and backbone network. In addition, CDN operators can achieve better system performance and cost savings on the transport bandwidth. + +![Diagram illustrating hot content caching in a mobile edge CDN. A dashed box labeled 'Campus/Enterprise/Residential area' contains two smartphones, a base station icon, a 'Mobile edge CDN' server, and an 'MEC' server. The base station is connected to the MEC server, which is connected to the 'Mobile core network' router. The Mobile edge CDN server is also connected to the MEC server and has icons for video, audio, and documents. The Mobile core network router is connected to a 'Central CDN' server. The label 'F.743.10(19)_F7-1' is at the bottom right.](cfda9df1319e04207eb28bcefd1dab7b_img.jpg) + +Diagram illustrating hot content caching in a mobile edge CDN. A dashed box labeled 'Campus/Enterprise/Residential area' contains two smartphones, a base station icon, a 'Mobile edge CDN' server, and an 'MEC' server. The base station is connected to the MEC server, which is connected to the 'Mobile core network' router. The Mobile edge CDN server is also connected to the MEC server and has icons for video, audio, and documents. The Mobile core network router is connected to a 'Central CDN' server. The label 'F.743.10(19)\_F7-1' is at the bottom right. + +**Figure 7-1 – Hot content caching in mobile edge CDN** + +### 7.2 VR/AR + +VR/AR involves a computer-generated three-dimensional (3D) simulation environment that presents virtual experience to the user. VR applications mainly include VR videos and VR games. + +In the next few years, smartphones and other smart devices will become the entry point for most VR/AR consumers. To achieve an immersive panoramic video experience, VR applications need at least 100 MB of bandwidth, which will pose great challenges for mobile network bandwidth. For example, a 60-frame 4K video consumes 1 GB to 10 GB of traffic per minute, and a 20 min 4K video requires almost 100 GB of traffic. CDN can cope with transferring and delivering large files to users while ensuring QoE. An MEC-enabled CDN allows users to download VR/AR data they request from the nearest CDN node, thus guaranteeing the immersive experience of a VR application. + +As shown in Table 7-1, the development of VR services can be divided into four grades, corresponding to different experience requirements. Deep immersion requires an RTT less than 20 ms and full immersion requires an RTT less than 10 ms, which imposes demanding requirements on network latency. Network latency needs the help of mobile edge CDN to meet the delay requirements of VR services, such as illustrated in Figure 7-2. + +**Table 7-1 – Experimental parameters for VR immersion experience** + +| Grade | Video resolution | Bandwidth | Round-trip time (RTT) | +|-----------------------|-------------------|---------------------|-----------------------| +| Entry-level immersion | 4K 2D 360 videos | 20-50 Mbit/s | < 40 ms | +| Partial immersion | 8K 2D 360 videos | 50-200 Mbit/s | < 30 ms | +| Deep immersion | 12K 2D 360 videos | 200 Mbit/s-1 Gbit/s | < 20 ms | +| Fully immersion | 24K 3D 360 videos | 2-5 Gbit/s | < 10 ms | + +![Diagram of VR service provided by the MEC-enabled CDN. A user wearing a VR headset is connected to a mobile edge CDN (MEC) via a radio tower. The MEC contains 'VR calculate' and 'VR data cache' components. A large arrow above the MEC points left, labeled 'High bandwidth low latency content delivery'. The MEC is connected to a 'Mobile core network' (represented by a square with four arrows), which is then connected to a 'Central CDN' (represented by a stack of servers). The text 'F.743.10(19)_F7-2' is at the bottom right.](e9314c83043183351ed74908e9bf2f90_img.jpg) + +Diagram of VR service provided by the MEC-enabled CDN. A user wearing a VR headset is connected to a mobile edge CDN (MEC) via a radio tower. The MEC contains 'VR calculate' and 'VR data cache' components. A large arrow above the MEC points left, labeled 'High bandwidth low latency content delivery'. The MEC is connected to a 'Mobile core network' (represented by a square with four arrows), which is then connected to a 'Central CDN' (represented by a stack of servers). The text 'F.743.10(19)\_F7-2' is at the bottom right. + +**Figure 7-2 – VR service provided by the MEC-enabled CDN** + +### 7.3 Live video + +Live video brings a much higher demand for concurrency, continuity and low latency. A complex mobile network environment may cause adverse effects, such as high latency, packet loss and video jam for live video service, which could affect live interaction with audiences and reduce QoE. Future live video will rely on high stability and interactivity, with a video delay ratio under 1%, latency less than 2 s and fluency higher than 99%, when there are high numbers of simultaneous online users. A traditional centralized CDN cannot meet the requirements for live video service. + +In an MEC-enabled CDN, video data is preferentially sent to the nearest mobile edge CDN based on global server load balance (GSLB) and the streaming media transmission protocol. Simple video processing and content management is supported by computing capability provided by MEC. In addition, with the radio network information service (RNIS) provided by the MEC system, video rate can be adaptively adjusted to achieve smooth live video transmission in a weak network situation. At the same time, live video can be saved in real time by a mobile edge CDN. If other users request playback of the live video, it can be directly distributed by the mobile edge CDN without returning to the conventional CDN. In MEC-enabled CDN, video data can be transferred to the live centre that is deployed on the backbone network through the intelligent scheduling system for video processing and fast content delivery. + +In addition, for the mobile live video shown in Figure 7-3, a bullet screen in live video and a real-time commentary subtitle, can be directly delivered to CDN nodes by MEC-based bullet screen delivery technology, thus ensuring real-time bullet screen interaction for users. + +![Figure 7-3: A mobile live video provided by a MEC-enabled CDN. The diagram shows a smartphone connected to a mobile edge CDN (MEC) via a radio tower. The MEC contains four stacked boxes: Authentication, Content management, Video processing, and Weak network optimization. An 'Edge pull' arrow points from the MEC to a 'Live centre'. The Live centre is a large box containing six smaller boxes: Transcoding, Security, Transcribing, Video processing, Resource monitoring, and Live management. An 'Open API' box is also in the Live centre. An arrow points from the Live centre to 'Operation control development'. Below the Live centre is the label 'F.743.10(19)_F7-3'. A 'Fast push' arrow points from the Live centre to another MEC. This second MEC also contains the same four stacked boxes. An arrow points from this MEC to a group of people via another radio tower.](d4af765160d04ecef538e5066006dc77_img.jpg) + +Figure 7-3: A mobile live video provided by a MEC-enabled CDN. The diagram shows a smartphone connected to a mobile edge CDN (MEC) via a radio tower. The MEC contains four stacked boxes: Authentication, Content management, Video processing, and Weak network optimization. An 'Edge pull' arrow points from the MEC to a 'Live centre'. The Live centre is a large box containing six smaller boxes: Transcoding, Security, Transcribing, Video processing, Resource monitoring, and Live management. An 'Open API' box is also in the Live centre. An arrow points from the Live centre to 'Operation control development'. Below the Live centre is the label 'F.743.10(19)\_F7-3'. A 'Fast push' arrow points from the Live centre to another MEC. This second MEC also contains the same four stacked boxes. An arrow points from this MEC to a group of people via another radio tower. + +**Figure 7-3 – A mobile live video provided by a MEC-enabled CDN** + +In a stadium environment, as shown in Figure 7-4, the MEC system can be configured with strong computing or storage capability and bandwidth to meet the processing and delivery requirements of the video uploaded by multiple video capture devices (e.g., video cassette recorders (VCRs), cameras, and civilian unmanned aerial vehicles). Also, there is a considerable amount of video traffic that needs to be transmitted back to local users through the MEC system. + +![Figure 7-4: Live video in a stadium environment. The diagram is similar to Figure 7-3 but with a key difference: the video source is now a 'Stadium' (enclosed in a dashed box). Inside the stadium, there are icons for a video camera, a still camera, and a drone, all pointing to a radio tower. This radio tower is connected to a 'Mobile edge CDN' (MEC) which contains the same four stacked boxes: Authentication, Content management, Video processing, and Weak network optimization. An 'Edge pull' arrow points from this MEC to the 'Live centre'. The Live centre and 'Operation control development' components are identical to Figure 7-3. Below the Live centre is the label 'F.743.10(19)_F7-4'. A 'Fast push' arrow points from the Live centre to a second MEC, which then connects to a group of people via a radio tower.](27b06ec9f42b5d727a2630f61a5f1861_img.jpg) + +Figure 7-4: Live video in a stadium environment. The diagram is similar to Figure 7-3 but with a key difference: the video source is now a 'Stadium' (enclosed in a dashed box). Inside the stadium, there are icons for a video camera, a still camera, and a drone, all pointing to a radio tower. This radio tower is connected to a 'Mobile edge CDN' (MEC) which contains the same four stacked boxes: Authentication, Content management, Video processing, and Weak network optimization. An 'Edge pull' arrow points from this MEC to the 'Live centre'. The Live centre and 'Operation control development' components are identical to Figure 7-3. Below the Live centre is the label 'F.743.10(19)\_F7-4'. A 'Fast push' arrow points from the Live centre to a second MEC, which then connects to a group of people via a radio tower. + +**Figure 7-4 – Live video in a stadium environment** + +Therefore, with the local access, computing, storage and bandwidth capabilities provided by the MEC system, a one-stop solution is available for capture, processing, delivery and transcoding of live video, + +as well as reducing video jams and long delays on a mobile network. With an MEC-enabled CDN, an expediently accessible, high-definition, low-latency, high-concurrency environment is brought to live video. Consequently, end users can enjoy a fast, fluent and stable live video experience. Furthermore, the traffic cost of a live video platform can be reduced by an MEC-enabled CDN, increasing user adherence and enhancing the brand value. + +## **8 Requirements for MEC-enabled CDN** + +To deploy a MEC-enabled CDN, the following requirements should be fulfilled. + +### **8.1 CDN service requirements** + +The requirements for a CDN specified in this clause are specific to the support of MEC-enabled CDNs. + +#### **8.1.1 Content ingestion** + +CSR01: The MEC-enabled CDN is required to ingest content from the content source into MEC-enabled CDN nodes. + +CSR02: The MEC-enabled CDN is recommended to ingest content from other CDN nodes into MEC-enabled CDN nodes. + +#### **8.1.2 Content acceleration** + +CSR03: A mobile edge CDN node is recommended to support content acceleration, e.g., that for video/audio on demand, large file download and distribution and live video acceleration. + +#### **8.1.3 Content process** + +CSR04: An MEC-enabled CDN is recommended to process original content locally in mobile edge nodes before distribution or delivery, including reformatting and transcoding. + +#### **8.1.4 Content cache** + +CSR05: An MEC-enabled CDN is required to cache or store content locally. + +#### **8.1.5 Content distribution** + +CSR06: An MEC-enabled CDN is recommended to distribute content within other nodes under the coverage of the MEC service, according to the distribution policy. + +#### **8.1.6 Content delivery** + +CSR07: An MEC-enabled CDN is required to deliver content corresponding to user requests to end-users. + +CSR08: An MEC-enabled CDN is recommended to deliver content from one node to other nodes. + +#### **8.1.7 Content request routing** + +CSR09: An MEC-enabled CDN is recommended to redirect content requests to other MEC-enabled CDN nodes or CDN nodes when local content is not available. + +#### **8.1.8 Connectivity** + +CSR10: Mobile edge CDN nodes are required to communicate with other mobile edge CDN nodes running on different MEC hosts through the MEC system. + +CSR11: Mobile edge CDN nodes are required to communicate with conventional CDN nodes deployed in external networks through the MEC system. + +#### **8.1.9 Traffic routing** + +CSR12: A mobile edge CDN node is recommended to retrieve selected user plane traffic. + +#### **8.1.10 Domain name system (DNS) support** + +CSR13: A CDN manager is recommended to configure a local DNS proxy on an MEC host by association with a specific fully qualified domain name (FQDN) according to the Internet protocol (IP) addresses allocated to a mobile edge CDN node. + +#### **8.1.11 Service customization** + +CSR14: Multiple types of service customization and priority rank are optionally being predetermined and supported for various uses of mobile edge CDNs. + +### **8.2 MEC functional requirements** + +The requirements for an MEC system specified in this clause are specific to the support of MEC-enabled CDNs. + +#### **8.2.1 Service request** + +MFR01: An MEC system is recommended to receive service requests from a CDN operation system. + +#### **8.2.2 App deployment** + +MFR02: The functional components of MEC-enabled CDNs are recommended to be virtualized and run as one or more MEC apps. + +#### **8.2.3 Traffic routing** + +MFR03: Application data traffic routing is required to be supported by an MEC system among mobile edge CDN nodes, user equipment (UE) and conventional CDN nodes. + +MFR04: An MEC system is recommended to influence traffic routing according to CDN requirements, such as location. + +#### **8.2.4 DNS support** + +MFR05: An MEC system is recommended to take charge of the DNS functionality of mobile edge CDN nodes to route all DNS traffic received from any UE to a local DNS server or proxy. + +MFR06: An MEC system can optionally support eDNS [b-IETF RFC 6891] functions, which can intercept DNS requests and insert location information. + +#### **8.2.5 Mobility support** + +MFR07: An MEC system is required to support service continuity of mobile subscribers when they are moving, resulting in a switch of serving MEC hosts on one MEC system. + +MFR08: An MEC system can optionally support service continuity of mobile subscribers when they are moving, resulting in a switch of serving MEC hosts among different MEC systems. + +MFR09: An MEC system is required to support two mobile edge CDN instances running on different MEC hosts in transmission of application-specific user-related information between instances through a specific interface for UE mobility support. + +#### **8.2.6 System monitoring and information open** + +MFR10: An MEC system is required to provide an application program interface (API) service function that provides information and services from the network to an MEC-enabled CDN. + +MFR11: An MEC system is recommended to collect virtualization resources usage information about the MEC host and expose it to the CDN manager. + +MFR12: An MEC system is recommended to provide up-to-date information of available MEC hosts to the CDN manager. + +MFR13: An MEC system is optionally able to store and provide the up-to-date topology status (e.g., location information) of a mobile edge CDN network to avoid circuitous traffic. + +MFR14: An MEC system is optionally able to provide necessary information about the radio access network, traffic load and network status to the CDN manager. + +MFR15: An MEC system is optionally able to provide radio access network information to an MEC-enabled CDN for its service optimization. + +MFR16: An MEC system is optionally able to monitor mobile edge CDN instances for performance measurement. + +MFR17: An MEC system can optionally receive: any configuration changes to the CDN from the CDN manager; any usage changes to the MEC system; or UE location changes, and notify CDN UE. + +MFR18: An MEC system should provide location information to assist UE to select the optimal MEC system or MEC-enabled CDN. + +#### **8.2.7 Dynamic virtualization resource allocation** + +MFR19: An MEC manager is recommended to dynamically configure the virtualization resources of mobile edge CDN instances according to requests from the CDN manager. + +### **8.3 Security** + +SC01: Any request for MEC system monitoring information (e.g., mobile edge CDN node performance, traffic load, network status, virtualization resource usage or available MEC hosts) is recommended to be authorized by the MEC system. + +### **8.4 Charging** + +CH01: An MEC system is recommended to provide charging-related information (e.g., traffic usage, application instantiation, access, usage duration and resource usage) to the CDN manager. + +CH02: An MEC-enabled CDN is recommended to support different charging rules. + +## Bibliography + +- [b-ITU-T F.743.6] Recommendation ITU-T F.743.6 (2018), *Service requirements for next generation content delivery networks*. +- [b-ETSI GS MEC 001] ETSI GS MEC 001 V2.1.1 (2019), *Multi-access edge computing (MEC): Terminology*. Available [viewed 2019-12-31] at: [https://www.etsi.org/deliver/etsi\\_gs/MEC/001\\_099/001/02.01.01\\_60/gs\\_MEC001v020101p.pdf](https://www.etsi.org/deliver/etsi_gs/MEC/001_099/001/02.01.01_60/gs_MEC001v020101p.pdf) +- [b-ETSI GS MEC 003] ETSI GS MEC 003 V2.1.1 (2019), *Multi-access edge computing (MEC): Framework and reference architecture*. Available [viewed 2020-01-01] at: [https://www.etsi.org/deliver/etsi\\_gs/MEC/001\\_099/003/02.01.01\\_60/gs\\_MEC003v020101p.pdf](https://www.etsi.org/deliver/etsi_gs/MEC/001_099/003/02.01.01_60/gs_MEC003v020101p.pdf) +- [b-IETF RFC 6891] IETF RFC 6891 (2013), *Extension mechanisms for DNS (EDNS(0))*. Available [viewed 2020-01-01] at: + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects 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logo](0538daaa5583c23e17db3a12f2281a55_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.743.27 + +# Requirements and framework of intelligent video surveillance platform for power grid infrastructure + +## Summary + +Recommendation ITU-T F.743.27 specifies the requirements and reference framework of an intelligent video surveillance platform for power grid infrastructure. + +Video surveillance has been widely utilized in various scenarios within the power sector, including transmission, transformation, distribution, equipment inspection, safety supervision, official business, and data centres. However, as the number of surveillance devices and monitoring scenarios increases, it encounters challenges such as limited communication network bandwidth and difficulties in managing the large volume of device connections. The integration of artificial intelligence technologies into the video surveillance platform significantly enhances the efficiency of real-time data analysis. By extending intelligence to the edge of the network through model training and distribution, this intelligent platform enables proactive threat detection and more efficient resource allocation for power grid infrastructure, particularly in remote areas with sparse populations, unattended facilities, and poor wireless signal conditions. This advancement ensures comprehensive oversight and protection of critical assets, thereby enhancing the overall security and reliability of power grid infrastructures. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.743.27 | 2025-01-24 | 16 | 11.1002/1000/16184 | + +## Keywords + +Artificial intelligence, framework, intelligent video surveillance, power grid infrastructure, requirements. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2025 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Overview ..... | 3 | +| 7 Reference framework of IVSP for PGI ..... | 4 | +| 8 Functional requirements of IVSP for PGI ..... | 6 | +| 8.1 AI management requirements..... | 6 | +| 8.2 Device management requirements ..... | 7 | +| 8.3 Media management requirements..... | 8 | +| Appendix I – Use cases of IVSP for PGI..... | 11 | +| Bibliography..... | 14 | + + + +## Requirements and framework of intelligent video surveillance platform for power grid infrastructure + +# 1 Scope + +This Recommendation specifies the requirements and reference framework of intelligent video surveillance platform for power grid infrastructure. The use cases are also presented in the appendix. + +The scope of this Recommendation includes: + +- Reference framework of intelligent video surveillance platform for power grid infrastructure. +- Functional requirements of intelligent video surveillance platform for power grid infrastructure. +- Use cases of intelligent video surveillance platform for power grid infrastructure. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T F.743.22] Recommendation ITU-T F.743.22 (2022), *Requirements and architecture of an algorithm-training system for intelligent video surveillance*. + +[ITU-T F.743.23] Recommendation ITU-T F.743.23 (2023), *Security requirements for video surveillance systems*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 artificial intelligence (AI)** [b-ITU-T M.3080]: Computerized system that uses cognition to understand information and solve problems. + +NOTE 1 – ISO/IEC 2382-28 defines AI as "an interdisciplinary field, usually regarded as a branch of computer science, dealing with models and systems for the performance of functions generally associated with human intelligence, such as reasoning and learning". + +NOTE 2 – In computer science, AI research is defined as the study of "intelligent agents": any device that perceives its environment and takes actions to achieve its goals. + +NOTE 3 – This includes pattern recognition, the application of machine learning and related techniques. + +NOTE 4 – Artificial-intelligence is the whole idea and concept of machines being able to carry out tasks in a way that mimics human intelligence and would be considered "smart". + +**3.1.2 intelligent surveillance camera (ISC)** [b-ITU-T F.743.19]: A kind of intelligent premises unit that can not only capture video, audio, and images but also process the captured images or video and execute particular analysis algorithms, recognize required information and output analysis results including alarms, video structure data, and recognition results. + +**3.1.3 personally identifiable information** [b-ISO/IEC 29100]: Any information that (a) can be used to identify the PII principal to whom such information relates, or (b) is or might be directly or indirectly linked to a PII principal. + +NOTE – To determine whether a PII principal is identifiable, an account should be taken of all the means which can reasonably be used by the privacy stakeholder holding the data, or by any other party, to identify that natural person. + +**3.1.4 premises unit** [b-ITU-T H.626]: A device located at the remote part of a video surveillance system and used to capture multimedia information (such as audio, video, image, alarm signal, etc.) from a surveilled object. + +**3.1.5 surveilled object** [b-ITU-T F.743]: The target (such as site, human, and related environment) which is surveilled. + +**3.1.6 video and image information** [b-ITU-T H.626.5]: Video clips, images, related files and content description information. + +**3.1.7 video surveillance system** [b-ITU-T H.626]: A telecommunication service focusing on video (but including audio and image) application technology, which is used to remotely capture multimedia (such as audio, video, image, alarm signal, etc.) and present them to the end user in a user friendly manner, based on managed broadband network with ensured quality, security and reliability. + +## **3.2 Terms defined in this Recommendation** + +None. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-------|-----------------------------------------| +| AI | Artificial Intelligence | +| CapEx | Capital Expenditure | +| FAQ | Frequently Asked Questions | +| IED | Intelligent Edge Device | +| IoT | Internet of Things | +| ISC | Intelligent Surveillance Camera | +| IVS | Intelligent Video Surveillance | +| IVSP | Intelligent Video Surveillance Platform | +| MPU | Mobile Premises Unit | +| PGI | Power Grid Infrastructure | +| PII | Personally Identifiable Information | +| PTZ | Pan/Tilt/Zoom | +| PU | Premises Unit | +| UAV | Unmanned Aerial Vehicle | +| VSS | Video Surveillance System | + +# **5 Conventions** + +In this Recommendation: + +- The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. +- The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement needs not be present to claim conformance. + +# 6 Overview + +The intelligent video surveillance platform (IVSP) for power grid infrastructure (PGI) is a tailored intelligent video surveillance (IVS) system designed to monitor and analyse video data within power grid environments using advanced technologies such as the Internet of things (IoT) and artificial intelligence (AI). This platform enables real-time monitoring, anomaly detection, and remote inspections of equipment and personnel in power grid scenarios. It supports unified access for various video devices and aims to enhance the operational convenience, efficiency, reliability, and security of the power system. + +The interconnection of IVSP for PGI with related entities is depicted in Figure 1. In this architecture, the intelligent surveillance cameras (ISCs) and the conventional surveillance cameras serve as premises units (PUs) in conventional video surveillance systems (VSS), which are continuously retrieving video and image information from surveilled PGIs. The connection of ISCs is shown in Figure 1 (c). + +Since the ISCs have gained the ability to execute particular analysis algorithms and recognize required information of the surveilled objects, the intelligent edge device (IED) for VSS is introduced to enhance the corresponding ability for conventional surveillance cameras as shown in Figure 1 (b). It empowers them with AI capabilities, providing a more efficient and responsive solution for surveillance and monitoring. In this way, AI capabilities which are characterized by continuously evolving AI models generated in the platform can be transferred and deployed on IEDs for VSS and ISCs through the interfaces. + +In situations where certain conventional surveillance cameras, such as unmanned aerial vehicles (UAVs) equipped with legacy cameras which serve as mobile premises units (MPUs), are unable to be upgraded with IEDs for VSS due to various constraints, they can still be supported by the platform as shown in Figure 1 (a). These cameras retain compatibility with the IVSP for PGI, ensuring their continued functionality by relaying merely video and image information of surveilled objects to the platform for analysis, facilitating real-time insights and decision-making. Therefore, the interface between the camera and the platform does not support AI capability deployment in such cases. + +![Diagram illustrating the interconnection of IVSP for PGI with related entities. The diagram shows a central 'IVSP for PGI' block connected to 'External applications/systems' on the left and 'Surveilled PGIs' on the right. The 'Surveilled PGIs' include 'Conventional surveillance cameras', 'IED for VSS', and 'ISCs'. Connections are labeled (a), (b), and (c). (a) is a direct connection from a camera to the IVSP, marked with an orange line (Nonsupport for AI capability deployment). (b) is a connection from a camera to an IED for VSS, which then connects to the IVSP, marked with a green line (Support for AI capability deployment). (c) is a direct connection from an ISC to the IVSP, marked with a green line (Support for AI capability deployment). A legend at the bottom indicates that an orange line represents 'Nonsupport for AI capability deployment' and a green line represents 'Support for AI capability deployment'. The text 'F.743.27(25)' is in the bottom right corner.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +Diagram illustrating the interconnection of IVSP for PGI with related entities. The diagram shows a central 'IVSP for PGI' block connected to 'External applications/systems' on the left and 'Surveilled PGIs' on the right. The 'Surveilled PGIs' include 'Conventional surveillance cameras', 'IED for VSS', and 'ISCs'. Connections are labeled (a), (b), and (c). (a) is a direct connection from a camera to the IVSP, marked with an orange line (Nonsupport for AI capability deployment). (b) is a connection from a camera to an IED for VSS, which then connects to the IVSP, marked with a green line (Support for AI capability deployment). (c) is a direct connection from an ISC to the IVSP, marked with a green line (Support for AI capability deployment). A legend at the bottom indicates that an orange line represents 'Nonsupport for AI capability deployment' and a green line represents 'Support for AI capability deployment'. The text 'F.743.27(25)' is in the bottom right corner. + +NOTE – For each conventional surveillance camera, it may either (a) connect directly to the IVSP or (b) connect to the IVSP via an IED for VSS. The simultaneous existence of both connection types is not permitted for each individual camera. The specific configuration regarding whether a conventional surveillance camera has a direct connection shall be determined by the administrator based on actual requirements. + +**Figure 1 – The interconnection of IVSP for PGI with related entities** + +By assigning AI capabilities on the edge of the network, the IVSP for PGI can benefit from: + +- On-device AI processing: These devices have the capability to process AI algorithms locally, reducing the need for continuous data transmission to the cloud and improving response times. +- Enhanced analytics: By deploying AI algorithms at the edge, these devices can perform advanced analytics such as object recognition, anomaly detection, and event classification directly on the ISC or IED for VSS. +- Capital Expenditure (CapEx) saving: This approach contributes to the protection of existing investments in conventional cameras. Rather than replacing all the legacy devices, adding IED for VSS allows for an incremental upgrade, maximizing the utility of the current infrastructure. +- Reduced bandwidth usage: Edge AI devices help optimize bandwidth usage by processing data locally and transmitting only relevant information or alerts, reducing the load on the network. +- Increased security: Processing data on the edge enhances the protection of personally identifiable information (PII) by avoiding the need to transmit sensitive information to external servers. It also improves security by minimizing the exposure of data during transit. + +The IVSP for PGI also provides interfaces for external applications or systems, facilitating data sharing and exchange, covering from video and image information to AI models or algorithms. This enables seamless integration and interoperability between different management systems, enhancing overall situational awareness and response capabilities. + +# 7 Reference framework of IVSP for PGI + +The reference framework of the IVSP for PGI is depicted in Figure 2, categorized into three main modules: AI management module, device management module, and media management module. Please note that this framework addresses only the functional aspects of the IVSP for PGI. For specific requirements regarding security aspects of the platform, refer to [ITU-T F.743.23]. + +![Reference framework of IVSP for PGI diagram showing three modules: AI management, Media management, and Device management, with their respective functions.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +The diagram illustrates the reference framework of IVSP for PGI. It is structured as follows: + +- IVSP for PGI (Platform)** contains three modules: + - AI management module** (dashed box) containing: + - Algorithm deployment (Function) + - Algorithm training (Function) + - Model validation and evaluation (Function) + - Sample data collection (Function) + - Sample data annotation (Function) + - Media management module** (dashed box) containing: + - Quality control and analytics (Function) + - Metadata management (Function) + - Media distribution (Function) + - Encryption and security (Function) + - Storage and archiving (Function) + - Device management module** (dashed box) containing: + - Discovery and registration (Function) + - Access control (Function) + - Status monitor (Function) + - Remote configuration (Function) + - Maintenance and troubleshooting (Function) + +Legend:      Platform         Module         Function + +F.743.27(25) + +Reference framework of IVSP for PGI diagram showing three modules: AI management, Media management, and Device management, with their respective functions. + +**Figure 2 – Reference framework of IVSP for PGI** + +The AI management module serves as the backbone of the intelligent video surveillance platform, facilitating the effective utilization of AI technologies for PGI monitoring. It is a tailored algorithm-training system for IVS defined in [ITU-T F.743.22], encompassing functions ranging from sample data collection to algorithm deployment onto IEDs for VSS or ISCs. Through data annotation, algorithm training, model validation and evaluation, and algorithm deployment, this module ensures the system's capability in real-time anomaly detection, asset recognition, and security surveillance, thereby enhancing the operational efficiency and reliability of the power grid environment. The subfunctions under this module include: + +- **Sample data collection:** This function is responsible for gathering relevant data that will be used to train and evaluate AI models. It stores datasets for various tasks such as asset recognition, anomaly detection, and security surveillance, ensuring that the data is diverse and representative to enhance model robustness. +- **Sample data annotation:** This function involves labelling and annotating the collected data to provide the necessary context for training AI models. This process is critical as it directly influences the quality of the training data and, consequently, the performance of the AI model. Annotation can be performed manually by human annotators or through automated tools, depending on the complexity and volume of the data. +- **Algorithm training:** This function is responsible for training new AI models or fine-tuning existing ones based on the collected data. It involves data pre-processing, model optimization, and training procedures. +- **Model validation and evaluation:** This function validates and assesses the performance of trained models using metrics such as accuracy, precision, recall, and F1 score. It helps in identifying model weaknesses and areas for improvement. +- **Algorithm deployment:** This function handles the deployment of trained models to IEDs for VSS or ICSs for real-time inference. It ensures efficient utilization of computational resources and seamless integration with the surveillance system. + +The device management module plays a crucial role in efficiently managing surveillance devices within the PGI network. It automates the discovery and registration of cameras, enforces access control to safeguard sensitive data, and continuously monitors device status for potential issues. Administrators can remotely configure devices, perform maintenance tasks, and troubleshoot issues, + +ensuring seamless operation and reliability of the surveillance system. The subfunctions under this module include: + +- **Discovery and registration:** This function automates the discovery and registration of surveillance cameras within the power infrastructure network. +- **Access control:** This function provides multiple account mechanisms and restricts access to sensitive devices and data, ensuring that only authorized users can configure or view the devices within their own privileges. +- **Status monitor:** This function continuously monitors the operational status of surveillance devices, detecting hardware failures, connectivity issues, or performance degradation. +- **Remote configuration:** This function allows administrators to remotely configure surveillance devices, adjust camera pan/tilt/zoom (PTZ) settings, and deploy software patches. +- **Maintenance and troubleshooting:** This function provides tools for diagnosing and troubleshooting issues related to surveillance devices, including firmware updates, hardware replacements, and system troubleshooting. + +The media management module is essential for handling and organizing video data within the surveillance system. It oversees storage and archiving, ensuring data integrity and compliance. Robust encryption and security measures protect data from unauthorized access. Additionally, it facilitates the efficient distribution of live streams and recorded footage while managing metadata for indexing and retrieval. Quality control checks and analytics capabilities enhance the system's effectiveness in extracting valuable insights from surveillance data. The subfunctions under this module include: + +- **Storage and archiving:** This function handles the storage and archival of video recordings captured by surveillance devices. It ensures data integrity, reliability, and compliance with retention policies. +- **Encryption and security:** This function protects video data both in transit and at rest, safeguarding against unauthorized access or tampering. +- **Media distribution:** This module facilitates the distribution of live video streams or recorded footage to authorized users or external systems. It ensures low-latency delivery and efficient bandwidth utilization. +- **Metadata management:** This function involves the extraction, indexing, and storage of metadata associated with video recordings, such as timestamps, camera IDs, and object tags. +- **Quality control and analytics:** This function performs quality control checks on video streams, detecting artifacts, distortions, or anomalies. It also enables analytics for extracting insights from surveillance data. + +# 8 Functional requirements of IVSP for PGI + +## 8.1 AI management requirements + +The overall functional requirements of the AI management module are required to comply with clauses 7.2, 7.3, 7.4 and 7.5 outlined in [ITU-T F.743.22]. Besides: + +- It is required to perform model pruning before deploying AI models to enhance efficiency and effectiveness, especially in ICSs where computational resources are limited, and real-time responsiveness is crucial. + +### **8.2 Device management requirements** + +#### **8.2.1 Discovery and registration** + +- DM-DR-1: It is recommended to support automatic discover and register new monitoring devices to ensure all devices are managed and monitored effectively. +- DM-DR-2: It is required to support manual device registration as a backup method in case automatic discovery fails or for devices that cannot be automatically detected. +- DM-DR-3: It is required to ensure compatibility with a wide range of surveillance camera models and brands for seamless integration and management within the platform. +- DM-DR-4: It is recommended to provide notifications for successful device discovery and registration to keep administrators informed about new devices entering the system. +- DM-DR-5: It is recommended to implement security measures such as encryption during the registration process to protect device information and prevent unauthorized access. +- DM-DR-6: It is recommended to implement audit trail logging for all activities related to device discovery and registration. + +#### **8.2.2 Access control** + +- DM-AC-1: It is required to support strict access control policies to ensure only authorized users can access and manipulate monitoring devices and data. +- DM-AC-2: It is required to support role-based access control mechanisms to regulate user permissions effectively. +- DM-AC-3: It is required to have the ability to create user groups with specific access rights in order to efficiently manage permissions for different teams or departments within the power grid corporation. +- DM-AC-4: It is recommended to implement multi-factor authentication for user access to enhance the security of the surveillance system and prevent unauthorized access. +- DM-AC-5: It is recommended to provide real-time monitoring of user activities and access logs in order to track who accessed which device and when, for auditing and security purposes. +- DM-AC-6: It is recommended to allow administrators to easily configure and customize access control policies based on the specific security requirements of the PGI. +- DM-AC-7: For specific requirements regarding PU access security, it is required to comply with clause 7.1 outlined in [ITU-T F.743.23]. + +#### **8.2.3 Status monitor** + +- DM-SM-1: It is required to support continuous monitoring of the status of devices, including online/offline status, operational status, battery levels, etc., to facilitate timely troubleshooting and maintenance. +- DM-SM-2: It is recommended to provide real-time alerts and notifications for any anomalies detected in device status. +- DM-SM-3: It is recommended to provide customizable thresholds for various operational parameters (e.g., battery levels, temperature) that trigger alerts when exceeded. +- DM-SM-4: It is recommended to implement a centralized dashboard that displays the real-time status of all monitored devices, allowing administrators to quickly assess the health of the surveillance system. +- DM-SM-5: It is recommended to support logging of device status changes to facilitate trend analysis and performance monitoring over time. + +#### **8.2.4 Remote configuration** + +- DM-RC-1: It is recommended to allow remote configuration of monitoring devices, enabling users to adjust parameters, perform firmware updates, etc., from a centralized interface. +- DM-RC-2: It is recommended to support secure communication channels for remote configuration to prevent unauthorized access. +- DM-RC-3: It is recommended to incorporate configuration backup and restore functionality to protect against data loss during remote configuration processes. +- DM-RC-4: It is recommended to provide version control for device configurations to track changes made during remote configuration processes and facilitate reverting to previous configurations if needed. +- DM-RC-5: It is recommended to enable batch configuration capabilities to efficiently apply the same configuration settings across multiple devices simultaneously. +- DM-RC-6: It is recommended to support the scheduling of configuration tasks to automate routine maintenance activities and minimize manual intervention. + +#### **8.2.5 Maintenance and troubleshooting** + +- DM-MT-1: It is recommended to offer comprehensive maintenance tools, including remote diagnostics, log viewing, and troubleshooting guides, to ensure uninterrupted operation of monitoring devices. +- DM-MT-2: It is recommended to provide fault management capabilities, such as automatic fault detection, isolation, and recovery procedures, to minimize downtime. +- DM-MT-3: It is recommended to incorporate predictive maintenance features that use historical data and analytics to anticipate potential device failures and proactively schedule maintenance activities. +- DM-MT-4: It is recommended to enable remote software updates and patches deployment for monitoring devices to ensure that they are running the latest firmware and security updates. +- DM-MT-5: It is recommended to provide a knowledge base or frequently asked questions (FAQ) section within the system that includes troubleshooting guides, known issues, and solutions for common device problems to assist administrators in addressing issues promptly. +- DM-MT-6: It is recommended to support remote rebooting of devices as a troubleshooting measure to resolve minor issues without the need for physical intervention. +- DM-MT-7: It is recommended to implement a ticketing system for tracking maintenance requests and recording the resolution process to maintain a history of maintenance activities. + +## **8.3 Media management requirements** + +#### **8.3.1 Storage and archiving** + +- MM-SA-1: It is required to support efficient storage and archiving of video footage captured by monitoring devices. +- MM-SA-2: It is required to provide data retention policies to ensure that video data is stored for a specified period and is automatically deleted or archived after expiration to comply with the regulatory requirements. +- MM-SA-3: It is recommended to provide scalable storage solutions to accommodate the growing volume of video data generated by the system. +- MM-SA-4: It is recommended to support automated storage policies that can automatically move data to different storage tiers (such as cold storage and hot storage) based on the frequency of use and importance of the video data. + +- MM-SA-5: It is recommended to implement a data integrity verification mechanism to ensure that stored recordings are not tampered with or corrupted, and to generate integrity reports. +- MM-SA-6: It is recommended to support multiple storage media, including local storage and cloud storage, to provide flexible storage options. +- MM-SA-7: It is recommended to implement efficient data retrieval and recovery functions for quick access and restoration of stored video data when needed. +- MM-SA-8: It is recommended to implement data compression techniques to reduce storage space utilization while maintaining the video quality to improve storage efficiency. + +#### **8.3.2 Encryption and security** + +- MM-ES-1: It is required to implement encryption mechanisms to secure stored and transmitted video data. +- MM-ES-2: It is required to integrate access control mechanisms to ensure that only authorized personnel can view, manage, and modify video data within the system. +- MM-ES-3: It is recommended to support end-to-end encryption to protect video data from unauthorized access or tampering. +- MM-ES-4: It is recommended to log and audit all access and modifications to video data for accountability purposes, ensuring traceability of actions within the system. +- MM-ES-5: It is recommended to conduct security assessments and audits to identify and address potential vulnerabilities and ensure compliance with security standards and regulations of the power grid corporation. + +#### **8.3.3 Media distribution** + +- MM-MD-1: It is required to facilitate the seamless distribution of video feeds to authorized users or monitoring centres. +- MM-MD-2: It is required to support multiple video formats and resolutions to accommodate various devices and user preferences. +- MM-MD-3: It is recommended to offer adaptive streaming capabilities to ensure optimal video quality across varying network conditions. +- MM-MD-4: It is recommended to provide real-time monitoring and alerting for video feed distribution failures or interruptions to ensure continuous availability of critical surveillance data. +- MM-MD-5: It is recommended to maintain a log of all distributed video feeds, including timestamps and recipient details, to ensure accountability and traceability. + +#### **8.3.4 Metadata management** + +- MM-MM-1: It is recommended to capture and manage metadata associated with video footage, including timestamps, geolocation data, and device identifiers. +- MM-MM-2: It is recommended to support customizable metadata schemas to facilitate efficient search and retrieval of video content. +- MM-MM-3: It is recommended to ensure proper indexing and cataloguing of metadata to enable quick and efficient retrieval of relevant video footage based on specified criteria. +- MM-MM-4: It is recommended to integrate metadata enrichment tools or algorithms to automatically tag video content with additional metadata, such as object recognition labels, to enhance search capabilities and data analysis. +- MM-MM-5: It is recommended to maintain data integrity and consistency for metadata entries to prevent errors or inconsistencies in metadata management that could impact the accuracy of search results. + +- MM-MM-6: It is recommended to support versioning and revision history for metadata entries to track changes, updates, and modifications over time, enabling users to review and revert to previous metadata states if needed. + +#### **8.3.5 Quality control and analytics** + +- MM-QC-1: It is recommended to perform real-time quality control checks to ensure the integrity and reliability of captured video streams. +- MM-QC-2: It is recommended to integrate analytics tools for video content analysis, enabling automated detection of anomalies or suspicious activities. +- MM-QC-3: It is recommended to implement a reporting mechanism that provides summaries and detailed reports of quality control checks and analytics findings, allowing users to review system performance and incident occurrences. +- MM-QC-4: It is recommended to support configurable thresholds for quality metrics, enabling users to define acceptable levels for video quality and trigger alerts when thresholds are exceeded. +- MM-QC-5: It is recommended to include historical data analysis capabilities, enabling users to review past performance trends and identify potential long-term issues or areas for improvement. + +## Appendix I + +### Use cases of IVSP for PGI + +(This appendix does not form an integral part of this Recommendation.) + +The intelligent video surveillance platform for power grid infrastructure addresses the unique challenges of wide operational areas, complex environments, and high-security requirements. It offers benefits such as comprehensive coverage, enhanced security, efficient operations, and automated asset management, contributing to the reliability, safety, and effectiveness of power infrastructure monitoring and surveillance. + +By introducing advanced technologies of AI and IoT, the intelligent video surveillance platform (IVSP) for power grid infrastructure (PGI) is capable of: + +- **Automated power line inspection:** The platform facilitates automated inspection of power lines, employing advanced image recognition and machine learning algorithms to identify critical issues such as ice accumulation, vegetation encroachment, or damaged components. By providing timely alerts regarding these conditions, the platform enhances the reliability of power transmission and significantly reduces the risk of outages. This proactive monitoring not only minimizes the need for manual inspections but also optimizes maintenance schedules, ensuring that potential hazards are addressed before they escalate into serious problems. + +![A drone flying over power lines and towers, illustrating automated power line inspection.](c3ee41c6d46565ab4198d0a9c69108c5_img.jpg) + +A photograph showing a drone in flight, positioned centrally, with its rotors spinning. The drone is flying over a landscape featuring several tall, lattice-style electrical transmission towers. Multiple power lines stretch across the sky, connecting the towers. The background shows a line of green trees and a body of water, possibly a river or lake, under a clear blue sky with some light clouds. The image illustrates the use of a drone for automated power line inspection. + +A drone flying over power lines and towers, illustrating automated power line inspection. + +**Figure I.1 – Use case for automated power line inspection** + +- **Substation security enhancement:** In challenging environments characterized by high levels of noise, magnetic interference, and extreme weather conditions, the platform enhances the security of power substations. Utilizing AI-powered surveillance capabilities, it can reliably detect unauthorized access attempts and potential intrusions, automatically alerting security personnel in real-time. Additionally, by analysing patterns of movement and behaviour around substations, the system can help identify suspicious activities and prevent tampering with critical infrastructure, thereby safeguarding the integrity and operational continuity of power facilities. + +![Figure I.2: Use case for substation security enhancement. The image shows a 3D simulation of a substation with a worker in a blue uniform and yellow hard hat standing near a fence. A large orange circular overlay with two person icons and the text 'Invalid Entry' is centered on the worker. Below this, two blue notification boxes appear: 'Mr. Zhang is detected with invalid entry at 3:00pm today' and 'Mr. Chen is detected with invalid entry at 3:00pm today', each with a 'More' button.](fbfaa723129f8b8e3be651c6fe7cfab7_img.jpg) + +Figure I.2: Use case for substation security enhancement. The image shows a 3D simulation of a substation with a worker in a blue uniform and yellow hard hat standing near a fence. A large orange circular overlay with two person icons and the text 'Invalid Entry' is centered on the worker. Below this, two blue notification boxes appear: 'Mr. Zhang is detected with invalid entry at 3:00pm today' and 'Mr. Chen is detected with invalid entry at 3:00pm today', each with a 'More' button. + +**Figure I.2 – Use case for substation security enhancement** + +- **Proactive fault detection:** The platform enables early detection of faults in various power infrastructure components, including transformers, circuit breakers, and power lines. By continuously monitoring visual data and applying predictive analytics, the system can identify irregularities – such as overheating or unusual vibrations – before they escalate into significant failures. This proactive approach not only helps maintain a continuous power supply but also mitigates the risk of costly downtime and emergency repairs, ultimately leading to improved service reliability. + +![Figure I.3: Use case for proactive fault detection. The image shows a 3D simulation of a substation with several power lines and transformers. On the right, a grid of six images displays 'visible light mode' and 'infrared mode' views of the infrastructure. The infrared mode images show heat signatures, with bright orange and yellow areas indicating potential hotspots or faults on the power lines and transformers.](fed351d1b7c4568a439a8682c27f8cc3_img.jpg) + +Figure I.3: Use case for proactive fault detection. The image shows a 3D simulation of a substation with several power lines and transformers. On the right, a grid of six images displays 'visible light mode' and 'infrared mode' views of the infrastructure. The infrared mode images show heat signatures, with bright orange and yellow areas indicating potential hotspots or faults on the power lines and transformers. + +**Figure I.3 – Use case for proactive fault detection** + +- **Asset tracking and management:** The platform streamlines the tracking and management of power infrastructure assets through real-time surveillance and data analytics. By integrating GPS data and visual monitoring, it allows operators to maintain an accurate inventory of equipment, track the condition of assets, and identify maintenance needs efficiently. This capability facilitates better planning for maintenance activities, reduces asset losses due to theft or misplacement, and contributes to the overall asset optimization, enhancing the lifecycle management of critical infrastructure. + +![A photograph of a server room with various pieces of equipment. Overlaid on the image are several digital callouts with location pin icons and text in Chinese, indicating different assets and their status. The callouts include information like '服务器' (Server), '网络设备' (Network device), and '存储设备' (Storage device).](3267a096e9ca525744d8cd820f12eb59_img.jpg) + +A photograph of a server room with various pieces of equipment. Overlaid on the image are several digital callouts with location pin icons and text in Chinese, indicating different assets and their status. The callouts include information like '服务器' (Server), '网络设备' (Network device), and '存储设备' (Storage device). + +Figure I.4 – Use case for asset tracking and management + +– **Efficient operation and maintenance:** By automating the detection of fire incidents, equipment alarms, and operational abnormalities, the platform significantly reduces the necessity for 24/7 manual monitoring. The system utilizes advanced algorithms to analyse visual data continuously, enabling swift identification of potential issues. This capability allows for timely interventions, minimizing the impact of equipment failures on overall operations and reducing reliance on human oversight. As a result, maintenance teams can focus on more strategic tasks, improving operational efficiency across the board. + +![A screenshot of a comprehensive monitoring dashboard. It features several charts and data panels: 'Devices' showing counts for online, offline, and unused states; 'Online' and 'Devices' bar charts showing metrics A and B over time (R1-R13 and dates); 'Network' donut chart showing distribution by type; 'Department' table with metrics for Transmission, Distribution, and Customer-side; and 'Alert' and 'Status' (CPU, MEM, DISK) charts.](1c427123350e0e73e2a109b79069314b_img.jpg) + +**Devices** + +324207 + +318099 In-use + +5208 unused + +293935 online + +20385 Offline + +4679 Deactivated + +2670362 + +2264387 online + +262143 Offline + +123832 Deactivated + +**Online** + +A B + +R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 + +**Network** + +Type-1 858 + +Type-2 163185 + +Type-3 32652 + +Type-4 11999 + +Type-5 14734 + +**Department** + +2959m 1.1m + +A B + +Transmission + +218m 1864m + +A B + +Transformation + +28.9m 222.1m + +A B + +Distribution + +6m 1.2m + +A B + +Customer-side + +**Alert** + +Alert Pre-Warning + +00:00:00 02:00:00 06:00:00 10:00:00 + +**Status** + +CPU MEM DISK + +0% - 20% 20% - 40% 40% - 60% 60% - 80% 80% - 100% + +2024-07-31 2024-08-02 2024-08-04 2024-08-06 2024-08-08 + +A screenshot of a comprehensive monitoring dashboard. It features several charts and data panels: 'Devices' showing counts for online, offline, and unused states; 'Online' and 'Devices' bar charts showing metrics A and B over time (R1-R13 and dates); 'Network' donut chart showing distribution by type; 'Department' table with metrics for Transmission, Distribution, and Customer-side; and 'Alert' and 'Status' (CPU, MEM, DISK) charts. + +Figure I.5 – Use case for efficient operation and maintenance + +## Bibliography + +- [b-ITU-T F.743] Recommendation ITU-T F.743 (V2) (2019), *Requirements and service description for video surveillance.* +- [b-ITU-T F.743.19] Recommendation ITU-T F.743.19 (2022), *Requirements for intelligent surveillance cameras in intelligent video surveillance systems.* +- [b-ITU-T H.626] Recommendation ITU-T H.626 (V2) (2019), *Architectural requirements for a video surveillance system.* +- [b-ITU-T H.626.5] Recommendation ITU-T H.626.5 (2022), *Architecture for intelligent video surveillance systems.* +- [b-ITU-T M.3080] Recommendation ITU-T M.3080 (2021), *Framework of artificial intelligence enhanced telecom operation and management (AITOM).* +- [b-ISO/IEC 29100] ISO/IEC 29100:2024, *Information technology – Security techniques – Privacy framework.* +<> + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.743.28-202501-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg b/marked/F/T-REC-F.743.28-202501-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c1629394c02f697f60ae954ad36bf274fa8082cb --- /dev/null +++ b/marked/F/T-REC-F.743.28-202501-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:3763acd7a0ed56aa30f3f90468c1fb0cb54573eb9045bca3eddf8976b4f0f41d +size 7219 diff --git a/marked/F/T-REC-F.743.28-202501-I_PDF-E/562f471e8153729557e6a4ee6343c32c_img.jpg b/marked/F/T-REC-F.743.28-202501-I_PDF-E/562f471e8153729557e6a4ee6343c32c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..244531b387264fc73958b01544da03a90a3977e0 --- /dev/null +++ b/marked/F/T-REC-F.743.28-202501-I_PDF-E/562f471e8153729557e6a4ee6343c32c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:90b2d338e7249c1290b0f531680ce9789982125cfbc6596640e86ea372f6c800 +size 33620 diff --git a/marked/F/T-REC-F.743.28-202501-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg b/marked/F/T-REC-F.743.28-202501-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..3055443d2dc6d69bbfef0cfd9aed483a5e203ed9 --- /dev/null +++ b/marked/F/T-REC-F.743.28-202501-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e4858a6acc411f8a38c575d9bd5087f71e863e887b99a4c7717d91e3f93a8ada +size 144201 diff --git a/marked/F/T-REC-F.743.28-202501-I_PDF-E/b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg b/marked/F/T-REC-F.743.28-202501-I_PDF-E/b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..45e7d249fe92cfb25999a39e85083281dde78a58 --- /dev/null +++ b/marked/F/T-REC-F.743.28-202501-I_PDF-E/b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d880e7ce8254a2ae2910bf757511c54fff5fd6183705d63b0f9f2cbb0baf59a5 +size 96072 diff --git a/marked/F/T-REC-F.743.28-202501-I_PDF-E/raw.md b/marked/F/T-REC-F.743.28-202501-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..f0b1f33b74037b32bf9c254a0270b093392dcdbf --- /dev/null +++ b/marked/F/T-REC-F.743.28-202501-I_PDF-E/raw.md @@ -0,0 +1,604 @@ + + +# Recommendation **ITU-T F.743.28 (01/2025)** + +SERIES F: Non-telephone telecommunication services + +Multimedia services + +--- + +**Functional framework and requirements for an +intelligent inspection system based on cloud- +edge-device collaboration in smart grids** + +![ITU logo](0538daaa5583c23e17db3a12f2281a55_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.743.28 + +# Functional framework and requirements for an intelligent inspection system based on cloud-edge-device collaboration in smart grids + +## Summary + +An intelligent inspection system is helpful for assisting humans in inspection work, offering advantages such as high efficiency and low operation and maintenance (O&M) costs. It is widely used in scenarios such as the inspection of power stations, substations and transmission lines. However, there are challenges with the inspection data transmitted to the cloud, such as the huge volumes, high complexity, long storage cycles and high computing frequency. Additionally, many substations and transmission lines are located in remote areas, where network connections are often poor, and the ability to properly inspect in harsh environments needs to be taken into consideration. An intelligent inspection system based on cloud-edge-device collaboration could address these challenges. + +Recommendation ITU-T F.743.28 specifies a functional framework, requirements and use cases for an intelligent inspection system based on cloud-edge-device collaboration in smart grids. It provides guidance for the utilization and selection of the right inspection system for a specific application. It can also supply a new collaboration paradigm to existing standards in smart grids. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.743.28 | 2025-01-24 | 16 | 11.1002/1000/16185 | + +## Keywords + +Cloud-edge-device collaboration, functional framework, intelligent inspection system, requirement, smart grid. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2025 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-------------------------------------------------------------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Overview ..... | 2 | +| 7 Functional framework..... | 3 | +| 8 Requirements for the cloud layer..... | 5 | +| 8.1 Functional requirements for the management unit..... | 5 | +| 8.2 Functional requirements for business unit..... | 7 | +| 9 Requirements for edge layer..... | 9 | +| 9.1 Functional requirements for service unit..... | 9 | +| 9.2 Functional requirements for business unit..... | 11 | +| 10 Requirements for device layer ..... | 11 | +| 10.1 Video and image acquisition function..... | 11 | +| 10.2 Device control function ..... | 12 | +| Appendix I – Use case of an intelligent inspection system based on cloud-edge-device collaboration in smart grids ..... | 13 | +| Bibliography..... | 15 | + + + +# Recommendation ITU-T F.743.28 + +# Functional framework and requirements for an intelligent inspection system based on cloud-edge-device collaboration in smart grids + +# 1 Scope + +This Recommendation specifies the functional framework and requirements for an intelligent inspection system based on cloud-edge-device collaboration in smart grids and provides a use case in smart grids. + +The scope of this Recommendation includes: + +- Overview +- Functional framework +- Requirements +- Use case + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T F.747.13] Recommendation ITU-T F.747.13 (2023), *Requirements and reference framework of cloud-edge collaboration in industrial machine vision systems*. + +[ITU-T X.1815] Recommendation ITU-T X.1815 (2023), *Security guidelines and requirements for IMT-2020 edge computing services*. + +[ITU-T Y.3510] Recommendation ITU-T Y.3510 (2016), *Cloud computing infrastructure requirements*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 artificial intelligence** [b-ISO/IEC 2382]: An interdisciplinary field, usually regarded as a branch of computer science, dealing with models and systems for the performance of functions generally associated with human intelligence, such as reasoning and learning. + +**3.1.2 cloud computing** [b-ITU-T Y.3500]: Paradigm for enabling network access to a scalable and elastic pool of shareable physical or virtual resources with self-service provisioning and administration on-demand. + +**3.1.3 collaboration** [b-ISO 13374-2]: A relation between two objects in a collaboration diagram, indicating that messages can pass back and forth between the objects. + +**3.1.4 edge computing** [b-ITU-T Y.3073]: This refers to a strategy to deploy the processing capability at the network edge where end terminals are connected, and to perform the processing of data which is derived from and fed to the end terminals. + +**3.1.5 model** [b-ITU-T F.748.16]: An output created by an algorithm running on training data that can generate an inference or prediction, based on input data. + +**3.1.6 smart grid** [b-ITU-T Y.4251]: An electricity network that can intelligently integrate the actions of all users connected to it – generators, consumers and those that do both – in order to efficiently deliver sustainable, economic and secure electricity supplies. + +## **3.2 Terms defined in this Recommendation** + +None. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|-------------------------------------| +| AI | Artificial Intelligence | +| API | Application Programming Interface | +| CPU | Central Processing Unit | +| GNSS | Global Navigation Satellite Systems | +| IP | Internet Protocol | +| MQTT | Message Queuing Telemetry Transport | +| NTP | Network Time Protocol | +| O&M | Operation and Maintenance | +| QoS | Quality of Service | +| REST | Representational State Transfer | +| TCP | Transmission Control Protocol | +| UAV | Unmanned Aerial Vehicle | +| UDP | User Datagram Protocol | + +# **5 Conventions** + +- The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. +- The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement needs not be present to claim conformance. +- The keywords "can optionally" indicate an optional requirement which is permissible, without implying any sense of being recommended. These terms are not intended to imply that the vendor's implementation must provide the option and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the specification. + +# **6 Overview** + +As power systems continue to advance, there are significant changes to inspection systems in terms of technical characteristics and functional forms. The perception devices, such as cameras, robots and unmanned aerial vehicles (UAVs), used in intelligent inspection systems are typical imaging and video surveillance systems, which are used to remotely capture and present multimedia to maintenance staff, with ensured quality, security and reliability. + +The massive amount of data produced due to the large-scale access of perception devices brings great processing pressure to the inspection system supported by cloud computing. The emergence of edge computing provides, to some extent, a solution to this challenge. Large tasks that are completely processed by the cloud layer can be decomposed into smaller, more finely grained tasks with reduced computing difficulty, and sent to each edge node. Due to the shorter distance between the edge node and the perception devices, the data processing and transmission is faster, and the delay is lower. However, the big data analysis ability of edge nodes is often insufficient. + +On this basis, the cloud layer, edge layer and device layer can be interconnected to form a cloud-edge-device collaboration system. The layers of cloud-edge-device collaboration in smart grids are shown in Figure 1. The intelligent inspection system based on cloud-edge-device collaboration achieves a reasonable distribution of computing resources, storage resources and network resources. + +![Diagram illustrating the layers of cloud-edge-device collaboration in smart grids. The diagram is divided into three horizontal layers by dashed lines. The top layer is labeled 'Cloud' and contains a 'Cloud centre' icon (a cloud with a server). The middle layer is labeled 'Edge' and contains 'Edge node 1' (a server icon) and 'Edge node n' (three server icons), with an ellipsis between them. The bottom layer is labeled 'Device' and contains icons for 'Camera' (a camera and a monitor), 'Robots' (a robot icon), and 'UAVs' (a drone icon). Below the UAVs icon is the text 'F.743.28(25)'.](562f471e8153729557e6a4ee6343c32c_img.jpg) + +The diagram illustrates the three layers of cloud-edge-device collaboration in smart grids. The top layer, labeled 'Cloud', contains the 'Cloud centre' represented by a cloud icon with a server inside. The middle layer, labeled 'Edge', contains multiple 'Edge nodes', with 'Edge node 1' and 'Edge node n' specifically labeled, separated by an ellipsis. The bottom layer, labeled 'Device', contains various perception and inspection devices: 'Camera' (represented by a camera and monitor icon), 'Robots' (represented by a robot icon), and 'UAVs' (represented by a drone icon). Below the UAVs icon, the text 'F.743.28(25)' is present. + +Diagram illustrating the layers of cloud-edge-device collaboration in smart grids. The diagram is divided into three horizontal layers by dashed lines. The top layer is labeled 'Cloud' and contains a 'Cloud centre' icon (a cloud with a server). The middle layer is labeled 'Edge' and contains 'Edge node 1' (a server icon) and 'Edge node n' (three server icons), with an ellipsis between them. The bottom layer is labeled 'Device' and contains icons for 'Camera' (a camera and a monitor), 'Robots' (a robot icon), and 'UAVs' (a drone icon). Below the UAVs icon is the text 'F.743.28(25)'. + +**Figure 1 – Layers of cloud-edge-device collaboration in smart grids** + +# 7 Functional framework + +The functional framework of an intelligent inspection system based on cloud-edge-device collaboration in smart grids is depicted in Figure 2. It shows the main components of the system, the functional units of each side and the basic relationship among the cloud, edge and inspection devices. + +![Functional framework of intelligent inspection system based on cloud-edge-device collaboration in smart grid. The diagram shows three layers: Cloud layer, Edge layer, and Device layer. The Cloud layer contains Management and Business units. The Edge layer contains Service and Business units. The Device layer contains Video and image acquisition and Device control. A vertical bar on the right shows Cloud-edge-device collaboration levels: Application, Service, and Resource.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +| | | | | | | | +|---------------------|-----------------------------|---------------------------------|------------------------------|-----------------------------|---------------------------------|----------------------------------------| +| Cloud layer | Management unit | | | Business unit | | Cloud-edge-device collaboration | +| | Edge node management | Virtualized resource management | Scheduling management | Inspection asset management | Inspection workorder management | | +| | Edge application management | Edge data management | Intelligent model management | Inspection data management | Defect management | | +| Edge layer | Service unit | | | Business unit | | Service collaboration | +| | Edge computing service | Edge container service | Edge data service | Inspection task management | | | +| Device layer | Video and image acquisition | | Device control | | | Resource collaboration | + +Functional framework of intelligent inspection system based on cloud-edge-device collaboration in smart grid. The diagram shows three layers: Cloud layer, Edge layer, and Device layer. The Cloud layer contains Management and Business units. The Edge layer contains Service and Business units. The Device layer contains Video and image acquisition and Device control. A vertical bar on the right shows Cloud-edge-device collaboration levels: Application, Service, and Resource. + +F.743.28(25) + +**Figure 2 – Functional framework of intelligent inspection system based on cloud-edge-device collaboration in smart grid** + +The inspection devices, such as cameras, robots and UAVs, are responsible for collecting data related to equipment status, transmission line status, construction sites and foreign body intrusions, which can be sent to the edge layer or the cloud layer as needed. + +The edge layer is responsible for the preliminary processing of inspection data, dispatching edge resources and providing services such as edge computing, edge container, edge data, edge intelligence, edge network, edge security and edge operation and maintenance (O&M). Additionally, it offers business functions such as inspection task management, intelligent analysis and actions with alarms. + +The cloud layer is in charge of global data aggregation and storage. It processes the data with precise models and manages nodes, virtual resources, resource scheduling, edge applications, edge data, intelligent models, networks, security and O&M. Further, it supports business functions like the management of inspection assets, work orders, inspection data and the identification and management of potential risks and defects. The cloud regularly dispatches models and applications to the edge layer and conducts periodic data synchronization. Through this approach, the cloud and edge collaborate effectively to meet the requirements of low latency and high reliability for intelligent power system inspections. + +Cloud-edge-device collaboration is mainly categorized into application collaboration, service collaboration and resource collaboration. The framework of these types of collaboration is given in [ITU-T F.747.13]. Application collaboration denotes the process whereby applications or models developed on the cloud are remotely deployed over the network to desired edge nodes, providing services to inspection devices. Moreover, it enables the management of the edge application lifecycle from the cloud. Service collaboration refers to the provision of key component management and service capabilities required by businesses, either in the cloud or at the edge layer, along with a rapid and flexible service integration and collaboration mechanism. This enhances the construction and response speed of edge applications, primarily encompassing service capabilities provided from the cloud, including intelligence, data and application management abilities. Resource collaboration pertains to the unified monitoring and maintenance of the total resources, resource utilization and operational status of the inspection system based on cloud-edge-device collaboration. This is achieved + +through a defined resource scheduling strategy that integrates, optimizes, maintains and dynamically allocates resources for computing, communication and storage. + +Appendix I presents examples of an intelligent inspection system based on cloud-edge-device collaboration from the functional framework in practical applications. + +# **8 Requirements for the cloud layer** + +## **8.1 Functional requirements for the management unit** + +#### **8.1.1 Edge node management function** + +The requirements of edge node management function include: + +- RENM1: It is required to support edge nodes registration. Edge devices are required to support the registration of finished and corresponding nodes creation in the cloud before first use. +- RENM2: It is required to support viewing the information and the running status of registered edge nodes in the cloud. Also, it is required to support editing and deleting these nodes in the cloud. +- RENM3: It is required to support viewing the operation logs of registered edge nodes. + +#### **8.1.2 Virtualized resource management function** + +The requirements of virtualized resource management can refer to [ITU-T Y.3510]. + +#### **8.1.3 Scheduling management function** + +The requirements of scheduling management function include: + +- RSM1: It is required to support real-time monitoring function for application deployment of edge nodes, including whether the application is deployed or in warm up. +- RSM2: It is required to support timely scheduling of computing nodes for tasks according to the requirements of clusters and scheduling strategies. It is required to support the following scheduling strategies including: + - RSM2-1: Scheduling the task to the named node. + - RSM2-2: Switching the task in a faulty node to a healthy node. + - RSM2-3: Scheduling tasks to corresponding categories of nodes according to configured strategies, and these nodes are classified into different labels. + - RSM2-4: Scheduling the task to the node closest to the requested Internet protocol (IP) area. + - RSM2-5: Scheduling the task to the node with the minimum workload according to the nodes' use of computing resources. + - RSM2-6: Customizing strategies to schedule tasks. +- RSM3: Visualization of the scheduling process and scheduling strategies. + +#### **8.1.4 Edge application management function** + +The requirements of edge application management function include: + +- REA1: It is required to support edge applications being deployed to multiple cloud-managed edge nodes and unified managed nodes, including updating and rolling back. +- REA2: It is required to support the lifecycle management of images, which includes organization, modification and deletion, as well as authorization for downloading and uploading images from the edge layer. + +- REA3: It is required to support configuring the upper limit of the central processing unit (CPU) and memory utilization for containers. It is required that configuring or modifying container resources does not impact any currently running applications. +- REA4: It is required to support the querying of container lists, container version information and the running status of the container. +- REA5: It is required to support the local and remote startup, stop, installation, upgrade and uninstallation of containers, as well as the remote application distribution function. +- REA6: It is required to support the monitoring of the CPU, memory and disk usage rates for containers, as well as reporting alarms for exceeding usage limits. + +#### 8.1.5 Edge data management function + +The requirements of edge data management function include: + +- REDM1: It is required to support message publishing and subscribing based on specified channels or topics. +- REDM2: It is required to support the simultaneous reception of publishing messages from several edge applications for the same channel or topic, as well as the simultaneous reception of subscription messages from several edge applications for the same channel or topic. +- REDM3: It is recommended to support two or more message routing protocols, including representational state transfer (REST) and message queuing telemetry transport (MQTT). +- REDM4: It is required to support time series messages and file messages for message routing. +- REDM5: It is required to support data transfer. It is recommended to support data types, including video, audio, point cloud, image and text. +- REDM6: It is required to support encrypting control command transfer from the cloud layer to the device layer. +- REDM7: It is required to support multiple network transport protocols, including transmission control protocol (TCP) and user datagram protocol (UDP). +- REDM8: It is recommended to support unified management and configuration of message endpoints, including creation, deletion, modification and querying. +- REDM9: It is recommended to support the integration, with sample library, of the electric artificial intelligence (AI) platform for the transmission of video data. + +#### 8.1.6 Intelligent model management function + +The requirements of intelligent model management function include: + +- RIM1: It is required to support the unified management of intelligent models and to have the ability to import intelligent models through customized visualization. +- RIM2: It is required to support the creation, deletion, modification and querying of models. +- RIM3: It is required to support managing multiple versions of intelligent models and choosing specified versions of models to deploy. +- RIM4: It is required to support rolling back models to a historical version. +- RIM5: It is required to support monitoring the resources of online models, including the CPU, memory, disk read/write and network uplink/downlink. +- RIM6: It is required to support real time viewing logs of online models and switching between different models. +- RIM7: It is required to support viewing the results of online models. +- RIM8: It is required to support viewing logs and results of offline models, including data source, business scenario, results and running time. + +- RIM9: It is recommended to support the integration with a model library of the electric AI platform for the transmission of models. + +#### **8.1.7 Network management function** + +The requirements of network management function include: + +- RNM1: It is required to support classifying data into flow or business type and monitoring network traffic of these data. +- RNM2: It is required to support scheduling management, congestion management and congestion avoidance of data. +- RNM3: It is required to support bandwidth assurance for high-priority businesses and users, through ways such as resource reservation. +- RNM4: It is required to support limiting the bit rate of data streams to be lower than bandwidth threshold through restricting data traffic. +- RNM5: It is required to support quality of service (QoS) bandwidth management of business level and user level. + +#### **8.1.8 Security management function** + +The requirements of security management function include: + +- RSMF1: It is required to support system security protection capabilities, which is required to comply with [ITU-T X.1815]. + +#### **8.1.9 O&M management function** + +The requirements of O&M management function include: + +- ROM1: It is required to support real-time monitoring function for edge nodes, including node service status, CPU utilization, memory utilization and graphic processing unit (GPU) utilization. +- ROM2: It is required to support real-time monitoring of the status of hardware and software in cloud, edge and device layers, and giving timely alarms for abnormal issues. +- ROM3: It is required to support monitoring management functions of edge nodes and container instances. +- ROM4: It is required to support log management functions, which include the collection, storage and retrieval of operating system logs and log directory management. +- ROM5: It is required to support alarm management functions, giving timely alarms for existing and potential abnormal issues. +- ROM6: It is required to support application programming interface (API) management and API integration with third-party systems. + +## **8.2 Functional requirements for business unit** + +#### **8.2.1 Inspection asset management function** + +The requirements of inspection asset management function include: + +- RIA1: It is required to support the data import of inspection devices, such as inspection robots, cameras and online monitoring devices, and to support the maintenance of hardware devices, as well as viewing and modifying configuration information. +- RIA2: It is recommended to support the import of inspection line ledgers and support batch generation of inspection data from uploaded format files. +- RIA3: It is recommended to support the import of tower pole ledgers and support batch generation of inspection data from uploaded format files. + +- RIA4: It is recommended to support the import of various equipment ledgers in substations and support batch generation of inspection data from uploaded format files. +- RIA5: It is recommended to support the setting, deletion and modification of detailed information for line and tower pole ledgers. The detailed information includes geographical information, such as latitude and longitude, line information, subsidiary facilities, defect summary and hazard summary. + +#### **8.2.2 Inspection work order management function** + +The requirements of inspection work order management function include: + +- RIW1: It is required to support the addition, modification and deletion of inspection tasks. +- RIW2: It is required to support the specification of information such as devices, lines, inspection personnel and time for inspection tasks. +- RIW3: It is required to support the review and dispatch of inspection work orders, as well as the automatic dispatch of monthly and daily tasks. +- RIW4: It is required to distribute inspection task work orders to the edge layer for automatic execution of inspection tasks. +- RIW5: It is required to support the planning of inspection routes, including tasks for tower poles, special inspections, on-site inspections and planned tasks. +- RIW6: It is required to support the setting of inspection modes such as routine inspections, special inspections, targeted inspections and custom inspections. +- RIW7: It is required to support the viewing of inspection results, inspection trajectories and downloading of inspection reports, as well as the review and reporting of hazards and defects. +- RIW8: It is required to support multi-angle camera device control and the issuing of control commands for remote surveillance. + +#### **8.2.3 Inspection data management function** + +The requirements of inspection data management function include: + +- RID1: It is required to support the storage of inspection videos and images uploaded from the edge layer or intelligent inspection devices through integration with object storage. +- RID2: It is recommended to manually annotate inspection image defects to generate samples. +- RID3: It is required to support the management functionality of intelligent inspection algorithm models, including adding and deleting model algorithms. +- RID4: It is required to support the querying and comparative analysis of inspection data, the generation of historical curves and the generation of analysis reports. Specifically, it includes: + - RID4-1: Combination condition query function: Query based on time period, equipment area, equipment type, recognition type, meter type selection and fuzzy filtering based on equipment tree. + - RID4-2: Historical curve generation function: Generate historical data curves within a specified range based on query conditions. + - RID4-3: Query, reset, export and view analysis report functions. +- RID5: It is recommended to support manual import of inspection data. +- RID6: It can optionally support the storage and analysis of inspection data, including visible light videos and images, infrared thermographs and audio. + +#### **8.2.4 Defect management function** + +The requirements of defect management function include: + +- RDM1: It is required to support defect library management, including adding, modifying, deleting and updating defects. +- RDM2: It is required to support threshold setting and automatic alarms based on predefined device alarm thresholds. +- RDM3: It is required to support display, updating and alarming of hidden risks and defects. +- RDM4: It is required to provide quick links to real-time monitoring screens for alarm information and support manual viewing of real-time monitoring screens of alarm devices for verifying alarm information and inputting feedback. +- RDM5: It is recommended to support one or more of the following intelligent analysis models, including: + - RDM5-1: Intrusion detection of personnel and animals, such as tripwire intrusion and area intrusion. + - RDM5-2: Detection of single-person and unmanned operations. + - RDM5-3: Personnel leaving post detection. + - RDM5-4: Detection of illegal construction. + - RDM5-5: Safety helmet detection and colour recognition. + - RDM5-6: Workwear detection. + - RDM5-7: Appearance defect detection of power facilities such as poles, hardware, insulators and instruments. + - RDM5-8: Recognition of meter readings such as temperature meters, oil level meters and water pressure meters. + - RDM5-9: Status recognition of power equipment such as indicators, circuit breakers and pressure plates, and isolating knife switches. + - RDM5-10: Thermal imaging detection of places and equipment such as generator sets, transmission lines, substations and distribution stations. + - RDM5-11: Thermal imaging detection of equipment such as server cabinets, batteries, power supplies and temperature controls in computer rooms. + - RDM5-12: Identification of weather conditions such as dense fog, standing water and ice covering. + - RDM5-13: Firework identification. + - RDM5-14: Identification of external foreign objects such as birds' nests and vines. + +# **9 Requirements for edge layer** + +## **9.1 Functional requirements for service unit** + +#### **9.1.1 Edge computing service function** + +The requirements of edge computing service function include: + +- REC1: It is required to support virtual machine lifecycle management such as creation, deletion and login. +- REC2: It is required to support container lifecycle management such as creation, startup, deletion and login. It is required to support containerization deployment of applications. + +- REC3: It is recommended to support GPU device pass-through capabilities, allowing the creation and operation of GPU resources through the cloud layer. + +#### **9.1.2 Edge container service function** + +The requirements of edge container service function include: + +- RECS1: It is required to support deploying multiple applications within a single container, and it is required that applications in different containers do not affect each other. +- RECS2: It is required to support container monitoring, including container restart, storage overrun, CPU utilization and memory utilization. +- RECS3: It is required to support an alarm function. It is required to trigger an alarm when the container restarts or when storage overruns. Furthermore, if the CPU or memory usage limit is exceeded, the system is required to not only report an alarm but also restart the container. +- RECS4: It is required to support remote container patch upgrade from cloud layer. +- RECS5: It is required to support communication and data interaction between containers. + +#### **9.1.3 Edge data service function** + +The requirements of edge data service function include: + +- RED1: It is required to support inspection device access; the authentication and identification are required for the access of inspection devices. +- RED2: It is required to support data synchronization between local data and message routing nodes of the cloud layer. +- RED3: It is required to support the storage of devices' configuration data. +- RED4: It is required to support the classified management and storage of data collected by inspection devices. +- RED5: It is required to support caching the business data of all inspection devices connected when the network is interrupted. +- RED6: It is required to support the acquisition of historical edge data for a specified time when the edge reconnects with the cloud network. Additionally, the time should be configurable. +- RED7: It is required to support the issuance of control commands for inspection devices. + +#### **9.1.4 Edge network service function** + +The requirements of edge network service function include: + +- REN1: It is required to support bandwidth adjustment of applications based on QoS policy. +- REN2: It is required to support keeping the service running when the network is disconnected or anomalous. + +#### **9.1.5 Edge security service function** + +The requirements of edge security service function include: + +- RES1: It is required to support establishing a secure transmission channel with access gateway for data transmission. +- RES2: It is required to support authentication and transmission encryption for connected devices. +- RES3: The safety protection is required to comply with [ITU-T X.1815]. + +#### **9.1.6 Edge O&M service function** + +The requirements of edge O&M service function include: + +- REOM1: It is required to support log management. The logs of edge applications, edge models and end device connections are required to be stored and accessed from the cloud layer. +- REOM2: It is required to support the monitoring of disk and network performance, as well as the alert system for disk failures and network faults. + +### **9.2 Functional requirements for business unit** + +#### **9.2.1 Inspection task management function** + +The requirements of inspection task management function include: + +- RIT1: It is required to support receiving and automatically executing inspection tasks issued from the cloud layer. +- RIT2: It is required to support receiving control commands of the cloud layer and forwarding the control commands to the device layer. + +#### **9.2.2 Intelligent analysis function** + +The requirements of intelligent analysis function include: + +- RIA1: It is recommended to support updating intelligent algorithm models issued from the cloud layer or edge layer. +- RIA2: It is recommended to support the automatic upload of defect and hidden danger samples after the analysis of intelligent models. +- RIA3: It is recommended to support proactive reporting of complex tasks and sending tasks to the cloud for processing. + +#### **9.2.3 Alarm linkage function** + +The requirements of alarm linkage function include: + +- RAL1: It is recommended to support the reporting and notification of event alarm information. +- RAL2: It is recommended to support the function of video recording or other alarm linkage triggered by alarm information. +- RAL3: It is recommended to support the querying and processing of alarm records. + +## **10 Requirements for device layer** + +## **10.1 Video and image acquisition function** + +The requirements of video and image acquisition function include: + +- RVIA1: It is required to support intelligent inspection devices such as various types of cameras, inspection robots and UAVs for video and image acquisition. The pan-tilt camera is recommended to support multiple presets and remote intelligent surveillance with preset target lock and focus functions. +- RVIA2: It is recommended to support one or more imaging methods such as visible light, infrared and ultraviolet. +- RVIA3: It is required to support controlled and automatic image acquisition modes, with adjustable acquisition intervals. + +- RVIA4: The collected video and image information is recommended to meet the requirements for target identification and cover the inspection monitoring area. +- RVIA5: It is recommended to take effective anti-shake measures to ensure the stability of the collected videos and images. +- RVIA6: It is recommended to take supplementary lighting measures when the on-site environmental lighting cannot meet the requirements of the inspection task for video and image quality. The lighting area is recommended to cover the monitoring imaging area of the inspection device, with even illumination and no obvious dark areas, and avoid affecting the surrounding environment. It is recommended to use intelligent uniform lighting, with white light supplementary lighting during nighttime inspections and infrared supplementary lighting after the inspection is complete. +- RVIA7: The collected videos and images are recommended to include absolute time information, with support for automatic or manual synchronization of the system time. The local clock can be synchronized using network time protocol (NTP) or satellite signals, and the deviation from local time after clock synchronization is recommended to be within 1 second. +- RVIA8: The collected videos and images are recommended to include absolute location information, which can be obtained through positioning methods such as global navigation satellite systems (GNSS). When satellite signals are weak or unavailable, it is recommended to support the acquisition of location information through other auxiliary positioning methods. +- RVIA9: It is recommended to support the overlay of time and location information, with character overlay not obstructing important targets and focus areas on the videos and images. + +## 10.2 Device control function + +The requirements of device control function include: + +- RDC1: It is required to support real-time reporting and querying of device status, device time, spatial location and other information. +- RDC2: It is required to support the receipt of control commands sent from the cloud layer or edge layer, such as restart, time calibration, cloud mirror control, navigation. +- RDC3: It is required to support the receipt of configuration parameters sent from the cloud layer or edge layer, such as video encoding format. +- RDC4: It is recommended to support updates of intelligent algorithms and model files sent from the cloud layer or edge layer. + +## Appendix I + +## Use case of an intelligent inspection system based on cloud-edge-device collaboration in smart grids + +(This appendix does not form an integral part of this Recommendation.) + +The extensive access of intelligent devices and massive perception data has promoted the further improvement of the intelligent application of the smart grid. However, it has also brought technical bottlenecks such as bandwidth constraints and network transmission delays. In practical applications, cloud computing based on data centres cannot meet the service requirement of real-time analysis. Similarly, edge computing cannot meet the requirement of model accuracy due to the limited computing power. Cloud-edge-device collaboration is one effective way to solve the aforementioned problems. By collaborating resources from the cloud and the edge, the goals of high precision, low consumption, quick response and low latency can be realized. The model deployment scheme is provided for different heterogeneous hardware resources and software environments. + +As shown in Figure I.1, for multi-task and multi-objective applications, with the collaboration of cloud computing and edge computing, the intelligent inspection system is capable of the following: + +- The edge layer receives images and video captured by cameras, UAVs, robots and other devices installed in substations, transmission line corridors and cable channels. The high-speed recognition model deployed at the edge layer is used for real-time processing and recognition of equipment defects and abnormal behaviours. +- When the edge layer recognizes equipment defects, equipment status abnormalities, foreign body intrusion and operational irregularities (e.g., not wearing helmets), it will report an alarm to the cloud. If the recognition model at the edge layer finds a suspected abnormal target, but the discriminant confidence does not meet the threshold, the image or video is uploaded to the cloud, and the high-precision model at the cloud layer is used for verification. If it is confirmed to be abnormal, an alarm will be issued. If no anomaly is found on the edge, the system periodically uploads images and videos to the cloud layer for storage. +- The cloud layer periodically analyses, processes and marks the new image and collected and stored video data retrains and optimizes the recognition model of the cloud layer and the edge layer, and then completes model delivery and update. +- The cloud layer periodically performs self-diagnosis on the system and checks the status of each image or of each of the video capture devices. If it has a black screen, is stuck, or is not working properly, an alarm is generated. + +The intelligent inspection system based on cloud-edge-device collaboration takes advantage of the edge layer being close to the data source to process on-site and realize a fast response. At the same time, the computing power and data aggregation capability of the cloud are utilized to provide specific guidance and adaptive adjustment for real-time analysis on the edge layer. The cooperation and complementarities of cloud computing and edge computing greatly improve the accuracy of analysis and the reliability of the system under the conditions of the bandwidth limitation and real-time requirements. This effectively supports defect monitoring in the power stations, substations and transmission lines. + +![A diagram showing an intelligent inspection system for smart grids. It consists of three main layers: Device, Edge, and Cloud. The Device layer includes cameras and a drone capturing images of a damaged insulator and a tower with a bird's nest. These are sent via image and video streaming to the Edge layer, which contains an Edge box and an Edge server. The Edge layer sends model delivery, alarm, and image recognition results to the Cloud layer, which is represented by a cloud icon and server. The Cloud layer also sends image recognition results back to the Edge layer, which then displays detected images of the damaged insulator and the tower with a bird's nest.](b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg) + +The diagram illustrates an intelligent inspection system based on cloud-edge-device collaboration in smart grids. It is organized into three main layers: + +- Device Layer:** + - Includes various imaging devices: cameras and a drone. + - Input: "Original image of damaged insulator" and "Original image of tower with bird's nest". + - Output: "Image" and "Video streaming" sent to the Edge layer. +- Edge Layer:** + - Includes an "Edge box" and an "Edge server". + - Receives "Image" and "Video streaming" from the Device layer. + - Sends "Model delivery", "Alarm", and "Image recognition results" to the Cloud layer. + - Receives "Image recognition results" from the Cloud layer. + - Output: "Detected image of damaged insulator" and "Detected image of tower with bird's nest". +- Cloud Layer:** + - Represented by a cloud icon and server. + - Receives "Model delivery", "Alarm", and "Image recognition results" from the Edge layer. + - Sends "Image recognition results" back to the Edge layer. + +A diagram showing an intelligent inspection system for smart grids. It consists of three main layers: Device, Edge, and Cloud. The Device layer includes cameras and a drone capturing images of a damaged insulator and a tower with a bird's nest. These are sent via image and video streaming to the Edge layer, which contains an Edge box and an Edge server. The Edge layer sends model delivery, alarm, and image recognition results to the Cloud layer, which is represented by a cloud icon and server. The Cloud layer also sends image recognition results back to the Edge layer, which then displays detected images of the damaged insulator and the tower with a bird's nest. + +F.743.28(25) + +**Figure I.1 – Intelligent inspection system based on cloud-edge-device collaboration in smart grids** + +## Bibliography + +- [b-ITU-T F.748.16] Recommendation ITU-T F.748.16 (2022), *Requirements for applications and services in smart manufacturing based on machine vision.* +- [b-ITU-T Y.3073] Recommendation ITU-T Y.3073 (2024), *Framework for service function chaining in information-centric networking.* +- [b-ITU-T Y.3500] Recommendation ITU-T Y.3500 (2014), *Information technology – Cloud computing – Overview and vocabulary.* +- [b-ITU-T Y.4251] Recommendation ITU-T Y.4251/F.747.1 (2012), *Capabilities of ubiquitous sensor networks for supporting the requirements of smart metering services.* +- [b-ISO 13374-2] ISO 13374-2:2007, *Condition monitoring and diagnostics of machines – Data processing, communication and presentation.* +- [b-ISO/IEC 2382] ISO/IEC 2382:2015, *Information technology – Vocabulary.* + + + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation 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logo](390120de4fe440c42fea8154fcaad334_img.jpg) + +The logo of the International Telecommunication Union (ITU), featuring the letters 'ITU' in blue inside a circular emblem with a globe and network lines. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.743.30 + +# Architecture for cloud computing platforms supporting a video surveillance system + +## Summary + +Recommendation ITU-T F.743.30 defines a cloud computing platform architecture that supports video surveillance systems. Cloud computing is a widely adopted paradigm that aims at providing various computing services over the network. By leveraging virtualization technology, cloud computing realizes a ubiquitous, flexible and scalable shared resources pool within the cloud environment which can be rapidly provisioned and released with minimal management effort based on user needs. Cloud computing offers flexible, efficient, reliable and distributed computing services for the large-scale surveillance video processing. This Recommendation describes the architecture, entities, reference points and service control flows of a cloud computing platform supporting a video surveillance system. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.743.30 | 2025-03-16 | 21 | 11.1002/1000/16226 | + +## Keywords + +Architecture, cloud computing, entity, reference point, service control flow, video surveillance. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2025 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|---------------------------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Architecture for cloud computing platform supporting a video surveillance system... | 3 | +| 6.1 Architecture overview ..... | 3 | +| 6.2 Functional entities ..... | 4 | +| 7 Reference points ..... | 5 | +| 7.1 Reference point Cc: CCS-CCMS ..... | 5 | +| 7.2 Reference point Cr: CCMS-AIRU ..... | 5 | +| 7.3 Reference point Sp: CCMS-PCCN ..... | 5 | +| 7.4 Reference point Ri: PCCN-AIRU ..... | 6 | +| 7.5 Reference point Cp: CCS-VCVS ..... | 6 | +| 7.6 Reference point Cp': MS-VCVS ..... | 6 | +| 8 Service control flows ..... | 6 | +| 8.1 Media cloud service creation..... | 6 | +| 8.2 Media cloud service update ..... | 6 | +| 8.3 Media cloud service deletion..... | 7 | +| 8.4 Media cloud service querying ..... | 8 | +| 8.5 Online media computing service ..... | 8 | +| 8.6 Offline media computing service ..... | 10 | +| Bibliography..... | 13 | + + + +# Recommendation ITU-T F.743.30 + +## Architecture for cloud computing platforms supporting a video surveillance system + +# 1 Scope + +This Recommendation defines the architecture, functional entities, reference points and service control flows of a cloud computing platform supporting a video surveillance system, which meets the requirements defined in [ITU-T F.743.8]. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T F.743.8] Recommendation ITU-T F.743.8 (2019), *Requirements for a cloud computing platform supporting a visual surveillance system*. +- [ITU-T H.626] Recommendation ITU-T H.626 (2019), *Architectural requirements for video surveillance system*. +- [ITU-T H.627] Recommendation ITU-T H.627 (2020), *Signalling and protocols for a video surveillance system*. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation defines the following terms: + +**3.1.1 central control server** [b-ITU-T H.626.3]: A device located at the central part of the visual surveillance system. It is used for centralized system management, service operation management, and access control. + +**3.1.2 centre management unit** [ITU-T H.626]: A device located at the main part of a video surveillance system. It is used for centralized system management, service operation management, etc. The main functions include management, authorization, accounting, charging, location and presence. + +**3.1.3 cloud computing** [b-ITU-T Y.3500]: Paradigm for enabling network access to a scalable and elastic pool of shareable physical or virtual resources with self-service provisioning and administration on-demand. + +**3.1.4 customer unit** [ITU-T H.626]: A device located at the customer part of a video surveillance system and used to present multimedia information (such as audio, video, image, alarm signal, etc.) to the end user. + +**3.1.5 media distribution unit** [ITU-T H.626]: A device located at the centre part of a video surveillance system. It is used to transport media from the PU (premises unit) to the CU (customer unit). The main functions include media receiving, media processing, media routing, media transmission, media forwarding and media replication. + +**3.1.6 media server** [ITU-T H.626]: A device located at the centre part of a video surveillance system. It is used to forward real-time media stream as well as store, retrieve and replay historical media stream. The media server receives the media stream from premises unit or other media server and forwards the media stream to other customer unit or media server. It consists of media distribution unit and media storage unit. + +**3.1.7 media storage unit** [ITU-T H.626]: A device located at the centre part of a video surveillance system. It is used to retrieve, store media and provide a streaming media serving capability. The main functions include media storage, media serving, media indexing and media downloading. + +**3.1.8 premises unit** [ITU-T H.626]: A device located at the remote part of a video surveillance system and used to capture multimedia information (such as audio, video, image, alarm signal, etc.) from a surveilled object. + +**3.1.9 service control unit** [ITU-T H.626]: A device located at the main part of a video surveillance system. It is used to access service control and signal call control between the PU and the CU. The main functions include access registration, access authentication, identification, authorization, call control, location, presence, and target media serving function selection. + +### **3.2 Terms defined in this Recommendation** + +None. + +## **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|------------------------------------| +| AIRU | Algorithm Image Repository Unit | +| CCMS | Cloud Computing Management Service | +| CCS | Central Control Server | +| CMU | Centre Management Unit | +| CRMU | Cloud Resource Management Unit | +| CSAG | Cloud Service Access Gateway | +| CU | Customer Unit | +| CVMU | Cloud Video Management Unit | +| MDU | Media Distribution Unit | +| MS | Media Server | +| MSU | Media Storage Unit | +| PCCN | Physical Cloud Computing Node | +| PU | Premises Unit | +| SCU | Service Control Unit | +| SDP | Session Description Protocol | +| VCVS | Virtual Cloud Video Service | +| VS | Video Surveillance | + +## **5 Conventions** + +None. + +# 6 Architecture for cloud computing platform supporting a video surveillance system + +### 6.1 Architecture overview + +A cloud computing-based video surveillance system consists of two parts, which are respectively the video surveillance (VS) system and the cloud computing platform. Figure 6-1 shows the architecture for the cloud computing platform supporting a video surveillance system. + +![Figure 6-1: Architecture for cloud computing platform supporting a video surveillance system. The diagram shows the interaction between a VS system (left) and a Cloud computing platform (right). The VS system includes CCS (CMU, SCU), MS (MDU, MSU), PU, and CU. The Cloud platform includes CCMS (CVMU, CRMU, CSAG), AIRU, and a Cloud resource pool (Media service layer with VCVS, Physical resource layer with PCCN). Control streams (red arrows) and media streams (black arrows) connect these components.](b3baf3a29b67c7425d2562ddbc52f0cc_img.jpg) + +The diagram illustrates the architecture for a cloud computing platform supporting a video surveillance system. It is divided into two main parts: the VS system (left) and the Cloud computing platform (right). + +**Legend:** + +- Control stream (red arrow) +- Media stream (black arrow) + +**VS system (defined in ITU-T H.626):** + +- CCS (Centre Control Server):** Contains CMU (Centre Management Unit) and SCU (Service Control Unit). +- MS (Media Server):** Contains MDU (Media Distribution Unit) and MSU (Media Storage Unit). +- PU (Premises Unit)** and **CU (Customer Unit)** are connected to the MS and CCS. +- Control streams (red arrows) are labeled: $Cc$ (CCS to CCMS), $Cs$ (CCS to CU), $Cm$ (MS to CCS), $Ds$ (MDU to MSU), $Ds'$ (MSU to MDU), $Mp$ (PU to MDU), $Mp'$ (MDU to PU), $Mc$ (CU to MSU), $Mc'$ (MSU to CU), $Pc$ (PU to CU), and $Ps$ (PU to CCS). +- Media streams (black arrows) are labeled: $Cp$ (CCMS to Media service layer), $Cp'$ (Media service layer to CCMS), and $Pc$ (PU to CU). + +**Cloud computing platform:** + +- CCMS (Cloud Computing Management Service):** Contains CVMU (Cloud Video Management Unit), CRMU (Cloud Resource Management Unit), and CSAG (Cloud Service Access Gateway). +- AIRU (Algorithm Image Repository Unit)** is connected to CCMS and the Cloud resource pool. +- Cloud resource pool:** Consists of two layers: + - Media service layer:** Contains three VCVS (Virtual Cloud Video Service) units. + - Physical resource layer:** Contains three PCCN (Physical Cloud Compute Node) units. +- Control streams (red arrows) are labeled: $Cr$ (CCMS to AIRU), $Sp$ (CCMS to Cloud resource pool), and $Ri$ (AIRU to Cloud resource pool). + +Figure 6-1: Architecture for cloud computing platform supporting a video surveillance system. The diagram shows the interaction between a VS system (left) and a Cloud computing platform (right). The VS system includes CCS (CMU, SCU), MS (MDU, MSU), PU, and CU. The Cloud platform includes CCMS (CVMU, CRMU, CSAG), AIRU, and a Cloud resource pool (Media service layer with VCVS, Physical resource layer with PCCN). Control streams (red arrows) and media streams (black arrows) connect these components. + +**Figure 6-1 – Architecture for cloud computing platform supporting a video surveillance system** + +The VS service is a telecommunication service focusing on video (and audio) application technology, which is used to remotely capture multimedia (such as audio, video, image, alarm signals, etc.), and present them to end users based on a managed network with ensured quality, security and reliability. (clause 3.2.11 of [ITU-T H.626]). The VS system mainly includes six units which are respectively centre management unit (CMU), service control unit (SCU), media distribution unit (MDU), media storage unit (MSU), premises unit (PU), and customer unit (CU). In addition, centre control server (CCS) consists of CMU and SCU, and media server (MS) consists of MDU and MSU. The function description of each functional entity is defined in [ITU-T H.626]. + +The cloud computing platform is integrated with the VS system and is implemented based on a computing cluster to meet the demand for video processing services. Based on the related service interfaces provided by the cloud computing platform, the VS system can use the video computing services on the cloud computing platform on demand. On the other hand, the cloud computing platform can obtain the video data to be processed from the VS system. The cloud computing platform mainly includes six units which are respectively cloud video management unit (CVMU), cloud resource management unit (CRMU), cloud service access gateway (CSAG), algorithm image repository unit (AIRU), virtual cloud video service (VCVS), and physical cloud compute node (PCCN). Usually, CVMU, CRMU and CSAG are implemented as a whole unit, and thus the cloud computing management service (CCMS) is defined, which consists of CVMU, CRMU and CSAG. The cluster of PCCNs forms the physical resource layer of the cloud computing platform, and the VCVSs form the media service layer of the cloud computing platform. + +- CVMU is the key unit for responding to the service requests of the VS system and managing the video surveillance services in the cloud computing platform. + +- CRMU is mainly responsible for managing the physical and virtual resources in the cloud computing cluster. +- CSAG is used to provide the VS system with access to the video processing services. Its functions include identity verification, security control, service discovery and selection. +- PCCN is the physical unit that provides the actual resources for supporting the video surveillance services. The PCCN can manage the local physical resources and video surveillance services. Usually, there are multiple PCCNs in the cloud platform, which form a cloud computing resource pool to support the video services efficiently and reliably. +- VCVS is a virtualized cloud video service instance which incorporates a specific program to provide a video surveillance service. Usually, there are multiple VCVSs in the cloud platform, each of which implements a specific media processing function. The VCVSs are deployed on the PCCNs based on the cloud virtualized technology, and they can be created and destroyed on demand. +- AIRU is used for storing and managing all video surveillance service images of the cloud computing platform. +- CCMS is used to accept the VS service requests, manage the cloud resource pool, and provide the services management, service access functions, etc. It is composed of CVMU, CRMU and CSAG. + +### 6.2 Functional entities + +#### 6.2.1 Cloud video management unit + +The CVMU is responsible for managing the video surveillance services and responding to the service requests of the VS system. When the VS system sends a video service request, the VSMU will trigger the CRMU to configure the cloud computing resources and generate the VCVS which has the corresponding service ability. It implements the following functions: + +- Authorize the access right of the user on the cloud computing platform. +- Receive and analyse the video surveillance service request from the VS system. +- Generate the service management request of the cloud platform according to the service management request of the VS system and send it to the CRMU. +- Manage the CSAG and AIRU. + +#### 6.2.2 Cloud resource management unit + +The CRMU is responsible for managing the physical and virtual resources in the cloud computing resource pool. When the VS system requires to deploy a VCVS in the cloud resource pool, it can call the CRMU to allocate a suitable amount of resources on the appropriate the PCCN. The cloud computing resource can be released by the CRMU once the VCVS is destroyed. It implements the following functions: + +- Receive the cloud service management request from the CVMU. +- Select the appropriate PCCN according to the service management request. +- Manage the physical and virtual resources in the cloud computing cluster. +- Monitor and collect the running status information of the physical and virtual resources in the cloud computing resource pool. + +#### 6.2.3 Cloud service access gateway + +The CSAG is used to provide the VS system with access to the video cloud services. All VCVSs are needed to be registered and maintained in the CSAG. When the VS system requests access to a video service, the CSAG performs the authentication and security control, and selects an appropriate VCVS for the request based on a load balancing strategy. It implements the following functions: + +- Receive the service access request from the VS system. +- Perform the authentication and security control for the service access request. +- Select the VCVS for the service request based on the corresponding load balancing strategy. +- Maintain the registration information of the VCVSs in the cloud computing resource pool. + +#### 6.2.4 Physical cloud computing node + +The PCCN is the physical unit that provides the actual resources for the video surveillance services. The cluster of PCCNs forms the cloud computing physical resource pool which is managed by the CRMU. Each PCCN is configured with a cloud computing engine responsible for the creation, update and deletion of the VCVSs. The PCCN can manage the local physical resources and video surveillance services. + +#### 6.2.5 Virtual cloud video service + +The VCVS is a virtual cloud service which incorporates a specific program to provide a video surveillance service. The VCVS is created based on a video service image pulled from the AIRU and is deployed in a PCCN. + +#### 6.2.6 Algorithm image repository unit + +The AIRU stores and manages all video surveillance service images used by the cloud computing platform. The video surveillance service image is an executable packet of software containing all components necessary to run a video surveillance service. It implements the following functions: + +- Store the video surveillance service images. +- Support the management of the video surveillance service images, including adding, deleting, browsing, and searching. +- Support the delivery function of the video surveillance service images. + +#### 6.2.7 Cloud computing management service + +CVMU, CRMU and CSAG are usually implemented as an integrated unit known as the CCMS. The CCMS is used to accept the VS service requests, manage the cloud computing resources, and provide the service management, service access functions, etc. It is composed of CVMU, CRMU and CSAG. + +## 7 Reference points + +### 7.1 Reference point Cc: CCS-CCMS + +The reference point Cc is located between the CCS and the CCMS. It is used to deliver the management signals between the CCS and the CCMS, including the following functions: + +- Delivering registration, authentication, authorization and accounting signals between the CCS and the CCMS. +- Delivering cloud video service management signals and service access requests between the CCS and the CCMS. + +### 7.2 Reference point Cr: CCMS-AIRU + +The reference point Cr is located between the CCMS and the AIRU. It is used to deliver the management and control signals between the CCMS and the AIRU, including adding, deleting, browsing and searching. + +### 7.3 Reference point Sp: CCMS-PCCN + +The reference point Sp is located between the CCMS and the PCCN. It is used to deliver the management and control signals between the CCMS and the PCCN in the cloud resource pool. + +### 7.4 Reference point Ri: PCCN-AIRU + +The reference point Ri is located between the PCCN and the AIRU. It is used to deliver the control signals and video surveillance service image files between the PCCN and the AIRU. + +### 7.5 Reference point Cp: CCS-VCVS + +The reference point Cp is located between the CCS and the VCVS. It is used to deliver the management and control signals between the CCS and the VCVS. The VCVS is the virtual functional unit, and it is created and destroyed dynamically based on the requirement of the VS system. Many VCVSs form a cloud media service pool. Actually, this reference point Cp connects one of the VCVSs in the cloud media service pool according to the specific function provided by the VCVS and the scheduling strategy of the cloud platform. + +### 7.6 Reference point Cp': MS-VCVS + +The reference point Cp' is located between the MS and the VCVS. It is used to deliver the media streams and media files between the MS and the VCVS. + +## 8 Service control flows + +### 8.1 Media cloud service creation + +Figure 8-1 shows the flows for creating the media cloud service in the cloud computing platform: + +- 1) The CCS initiates a media service creating request and sends it to the CCMS. +- 2) When the CCMS receives the request, it authenticates the permission and selects a PCCN based on the scheduling strategy, and sends a VCVS creating request to the PCCN. +- 3) When the PCCN receives the request, it requests the AIRU for the image of the media service. +- 4) Upon receiving the request, the AIRU transmits the image to the PCCN. +- 5) The PCCN creates a VCVS for the media service. +- 6) The PCCN sends a service registration request to the CCMS. +- 7) After registering the VCVS, the CCMS responses to the CCS. + +![Sequence diagram showing the high-level procedural flows for creating a media cloud service. The participants are CCS, CCMS, PCCN, and AIRU. The sequence of messages is: 1. Request creating service (CCS to CCMS), 2. Request creating VCVS (CCMS to PCCN), 3. Request image (PCCN to AIRU), 4. Return image (AIRU to PCCN), 5. Create VCVS (internal PCCN message), 6. Register (PCCN to CCMS), 7. Response (CCMS to CCS).](af6be343f0c0a8f155f965dcf337b8af_img.jpg) + +``` +sequenceDiagram + participant CCS + participant CCMS + participant PCCN + participant AIRU + Note right of PCCN: 5. Create VCVS + CCS->>CCMS: 1. Request creating service + CCMS->>PCCN: 2. Request creating VCVS + PCCN->>AIRU: 3. Request image + AIRU-->>PCCN: 4. Return image + PCCN->>CCMS: 6. Register + CCMS-->>CCS: 7. Response +``` + +F.743.30(25) + +Sequence diagram showing the high-level procedural flows for creating a media cloud service. The participants are CCS, CCMS, PCCN, and AIRU. The sequence of messages is: 1. Request creating service (CCS to CCMS), 2. Request creating VCVS (CCMS to PCCN), 3. Request image (PCCN to AIRU), 4. Return image (AIRU to PCCN), 5. Create VCVS (internal PCCN message), 6. Register (PCCN to CCMS), 7. Response (CCMS to CCS). + +**Figure 8-1 – High-level procedural flows for creating a media cloud service** + +### 8.2 Media cloud service update + +Figure 8-2 shows the flows for updating the media cloud service in the cloud computing platform: + +- 1) The CCS initiates a media service updating request and sends it to the CCMS. + +- 2) The CCMS authenticates the permission and sends a VCVS updating request to the corresponding PCCN. +- 3) Upon receiving the request, the PCCN sends an old VCVS deregistration request to the CCMS. +- 4) After deleting the registration information of the old VCVS, the CCMS replies ACK to the PCCN. +- 5) When the PCCN receives the ACK, it deletes the old VCVS of the media service. +- 6) After deleting the old VCVS, the PCCN requests the AIRU for the image of the media service. +- 7) After receiving the request, the AIRU transmits the image to the PCCN. +- 8) The PCCN creates a new VCVS for the media service. +- 9) The PCCN sends a service registration request to the CCMS. +- 10) After receiving the registration request, the CCMS registers the new VCVS, and responses to the CCS. + +![Sequence diagram showing high-level procedural flows for updating a media cloud service. Lifelines: CCS, CCMS, PCCN, AIRU. The sequence starts with CCS sending a 'Request updating service' to CCMS. CCMS sends 'Request updating VCVS' to PCCN. PCCN sends 'Deregister old VCVS' to CCMS. CCMS sends 'ACK' to PCCN. PCCN performs 'Delete old VCVS' (self-call). PCCN sends 'Request new image' to AIRU. AIRU sends 'Return image' to PCCN. PCCN performs 'Create VCVS' (self-call). PCCN sends 'Register new VCVS' to CCMS. CCMS sends 'Response' to CCS.](4e4be0bd8b235167902f2c03e41da651_img.jpg) + +``` + +sequenceDiagram + participant CCS + participant CCMS + participant PCCN + participant AIRU + Note right of PCCN: 5. Delete old VCVS + Note right of PCCN: 8. Create VCVS + CCS->>CCMS: 1. Request updating service + CCMS->>PCCN: 2. Request updating VCVS + PCCN->>CCMS: 3. Deregister old VCVS + CCMS->>PCCN: 4. ACK + PCCN->>PCCN: 5. Delete old VCVS + PCCN->>AIRU: 6. Request new image + AIRU->>PCCN: 7. Return image + PCCN->>PCCN: 8. Create VCVS + PCCN->>CCMS: 9. Register new VCVS + CCMS->>CCS: 10. Response + +``` + +F.743.30(25) + +Sequence diagram showing high-level procedural flows for updating a media cloud service. Lifelines: CCS, CCMS, PCCN, AIRU. The sequence starts with CCS sending a 'Request updating service' to CCMS. CCMS sends 'Request updating VCVS' to PCCN. PCCN sends 'Deregister old VCVS' to CCMS. CCMS sends 'ACK' to PCCN. PCCN performs 'Delete old VCVS' (self-call). PCCN sends 'Request new image' to AIRU. AIRU sends 'Return image' to PCCN. PCCN performs 'Create VCVS' (self-call). PCCN sends 'Register new VCVS' to CCMS. CCMS sends 'Response' to CCS. + +**Figure 8-2 – High-level procedural flows for updating a media cloud service** + +### 8.3 Media cloud service deletion + +Figure 8-3 shows the flows of deleting the media cloud service in the cloud computing platform: + +- 1) The CCS initiates a media service deleting request and sends it to the CCMS. +- 2) When the CCMS receives the request, it authenticates the permission and sends a VCVS deleting request to the corresponding PCCN. +- 3) The PCCN sends a VCVS deregistration request to the CCMS. +- 4) After deleting the registration information of the VCVS, the CCMS sends an ACK to the PCCN. +- 5) When the PCCN receives the ACK, it deletes the VCVS of the media service. +- 6) After deleting the VCVS, the PCCN sends a response to the CCMS. +- 7) The CCMS responses to the CCS. + +![Sequence diagram for deleting a media cloud service. Lifelines: CCS, CCMS, PCCN. The process involves: 1. CCS sends 'Request deleting service' to CCMS; 2. CCMS sends 'Request deleting VCVS' to PCCN; 3. PCCN sends 'Deregister VCVS' to CCMS; 4. CCMS sends 'ACK' to PCCN; 5. PCCN sends 'Delete VCVS' to CCMS; 6. CCMS sends 'Response' to PCCN; 7. CCMS sends 'Response' to CCS. Reference F.743.30(25) is shown at the bottom right.](4801720824e4b5e2361a5564f91cfb70_img.jpg) + +``` + +sequenceDiagram + participant CCS + participant CCMS + participant PCCN + Note right of PCCN: F.743.30(25) + CCS->>CCMS: 1. Request deleting service + CCMS->>PCCN: 2. Request deleting VCVS + PCCN->>CCMS: 3. Deregister VCVS + CCMS->>PCCN: 4. ACK + PCCN->>CCMS: 5. Delete VCVS + CCMS->>PCCN: 6. Response + CCMS->>CCS: 7. Response + +``` + +Sequence diagram for deleting a media cloud service. Lifelines: CCS, CCMS, PCCN. The process involves: 1. CCS sends 'Request deleting service' to CCMS; 2. CCMS sends 'Request deleting VCVS' to PCCN; 3. PCCN sends 'Deregister VCVS' to CCMS; 4. CCMS sends 'ACK' to PCCN; 5. PCCN sends 'Delete VCVS' to CCMS; 6. CCMS sends 'Response' to PCCN; 7. CCMS sends 'Response' to CCS. Reference F.743.30(25) is shown at the bottom right. + +**Figure 8-3 – High-level procedural flows for deleting a media cloud service** + +### 8.4 Media cloud service querying + +Figure 8-4 shows the flows of querying the media cloud services in the cloud computing platform: + +- 1) The CCS initiates a service querying request and sends it to the CCMS. +- 2) When the CCMS receives the request, it authenticates the permission and returns the service information to the CCS. + +![Sequence diagram for querying media cloud services. Lifelines: CCS, CCMS. The process involves: 1. CCS sends 'Request querying services' to CCMS; 2. CCMS sends 'Return services information' to CCS. Reference F.743.30(25) is shown at the bottom right.](a26e142d3df5bef41a84a9dd099d7825_img.jpg) + +``` + +sequenceDiagram + participant CCS + participant CCMS + Note right of CCMS: F.743.30(25) + CCS->>CCMS: 1. Request querying services + CCMS->>CCS: 2. Return services information + +``` + +Sequence diagram for querying media cloud services. Lifelines: CCS, CCMS. The process involves: 1. CCS sends 'Request querying services' to CCMS; 2. CCMS sends 'Return services information' to CCS. Reference F.743.30(25) is shown at the bottom right. + +**Figure 8-4 – High-level procedural flows for querying media cloud services** + +### 8.5 Online media computing service + +For understanding how the cloud platform interacts with the VS system, it is necessary to provide the complete online media computing service procedure which includes the real-time media stream signalling process defined in [ITU-T H.627]. Figure 8-5 shows the flows of online media computing services in the cloud computing platform: + +- 1) The CCS initiates an online media computing service request and sends it to the CCMS. +- 2) The CCMS authenticates the permission, selects a VCVS for the service request according to the corresponding load balancing strategy and sends an online computing request to the VCVS. +- 3) After receiving the request, the VCVS sends an invite request to the CCS for obtaining the media stream. +- 4) After the CCS receives the request, it sends an invite request to the MS. +- 5) After the MS receives the invite request from the CCS, it replies with a 200 OK response. +- 6) After the CCS receives the 200 OK response returned by the MS, it sends an invite request to the PU. +- 7) After the PU receives the invite request from the CCS, it replies with a 200 OK response. + +- 8) After the CCS receives the 200 OK response returned by the PU, it sends an ACK message to the MS. +- 9) After the CCS receives the 200 OK response returned by the PU, it sends an ACK message to the PU. The PU starts to push stream to the MS after receiving the ACK. +- 10) The CCS sends an invite request to the MS, asking to push the media stream to the specified VCVS. +- 11) The MS receives the invite request and replies with a 200 OK response. +- 12) The CCS sends the 200 OK response to the VCVS. +- 13) After receiving the 200 OK response, the VCVS replies with an ACK message to complete the Invite session with the CCS. +- 14) The CCS sends an ACK message to the MS, completing the invite session establishment process with the MS. Then, the media stream is transmitted from the MS to the VCVS (see Note). +- 15) When the media data is streamed to the VCVS, the VCVS processes the data and returns the processed results to the CCS. +- 16) When the VCVS starts processing the media, it sends a processing started response to the CCMS. +- 17) When the CCMS receives the processing started response, it sends a service started response to the CCS. +- 18) The CCS sends a service stop request to the CCMS. +- 19) When the CCMS receives the service stop request, it authenticates the permission and sends the service stop request to the corresponding VCVS. +- 20) After receiving the stop request, the VCVS sends a BYE request to the CCS. +- 21) The CCS sends the 200 OK response to the VCVS. +- 22) After the CCS receives the BYE request, it sends a BYE request to the MS. +- 23) The MS sends the 200 OK response to the CCS after stopping the media stream. +- 24) The CCS sends a BYE request to the PU. +- 25) The PU sends the 200 OK response to the CCS after stopping the media stream. +- 26) When the media stream is stopped, the VCVS sends a processing stopped response to the CCMS. +- 27) When the CCMS receives the processing stopped response, it sends the service stopped response to the CCS. + +NOTE – The process of the real-time media stream obtaining initiated by the VCVS, which corresponds to steps 3-14 and steps 20-25, is the same as that defined in clause 8.2 of [ITU-T H.627]. + +![Sequence diagram showing high-level procedural flows for online media computing services between PU, MS, CCS, CCMS, and VCVS. The diagram includes 27 numbered steps and two red arrows representing real-time media streams.](fa859e4e468bfb2710a94527f2c504af_img.jpg) + +``` + +sequenceDiagram + participant PU + participant MS + participant CCS + participant CCMS + participant VCVS + + Note right of VCVS: F.743.30(25) + + CCS->>CCMS: 1. Request online computing service + CCMS->>VCVS: 2. Request online computing + CCS->>MS: 3. Invite (With SDP) + MS->>CCS: 4. Invite (With SDP) + CCS->>MS: 5. 200 OK (With SDP) + MS->>PU: 6. Invite (With SDP) + PU->>MS: 7. 200 OK (With SDP) + MS->>CCS: 8. ACK (With SDP) + CCS->>MS: 9. ACK + Note left of MS: Real-time media stream + MS->>CCS: 10. Invite (With SDP) + CCS->>MS: 11. 200 OK (With SDP) + CCS->>VCVS: 12. 200 OK (With SDP) + CCS->>MS: 13. ACK + MS->>CCS: 14. ACK + Note right of CCS: Real-time media stream + Note right of VCVS: 15. Process + VCVS->>CCS: Return results + CCS->>CCMS: 16. Processing started + CCS->>MS: 17. Service started + CCS->>CCMS: 18. Stop + CCMS->>VCVS: 19. Stop + CCS->>MS: 20. BYE + CCS->>VCVS: 21. 200 OK + MS->>CCS: 22. BYE + CCS->>MS: 23. 200 OK + MS->>PU: 24. BYE + PU->>MS: 25. 200 OK + CCS->>CCMS: 26. Processing stopped + CCS->>MS: 27. Service stopped + +``` + +Sequence diagram showing high-level procedural flows for online media computing services between PU, MS, CCS, CCMS, and VCVS. The diagram includes 27 numbered steps and two red arrows representing real-time media streams. + +**Figure 8-5 – High-level procedural flows for online media computing services** + +### 8.6 Offline media computing service + +For understanding how the cloud platform interacts with the VS system, it is necessary to provide the complete offline media computing service procedure which includes the historical media file downloading signalling process defined in [ITU-T H.627]. Figure 8-6 shows the flows of the offline media computing services in the cloud computing platform: + +- 1) The CCS initiates an offline media computing service request and sends it to the CCMS. + +- 2) The CCMS authenticates the permission, selects a VCVS for the service request according to the corresponding load balancing strategy and sends an offline computing request to the VCVS. +- 3) After the VCVS receives the offline computing request, it records the request and then sends a request submitted response to the CCMS. +- 4) After the CCMS receives the request submitted response, it sends the request submitted response to the CCS. +- 5) After receiving the offline computing request, the VCVS sends an invite request to the CCS for obtaining the historical media data. +- 6) After the CCS receives the request, it sends an invite request to the MS. +- 7) After the MS receives the Invite request from the CCS, it replies with a 200 OK response. +- 8) After the CCS receives the 200 OK response returned by the MS, it sends the 200 OK response to the VCVS. +- 9) After receiving the 200 OK response, the VCVS replies with an ACK message to complete the Invite session with the CCS. +- 10) The CCS sends an ACK message to the MS, completing the invite session establishment process with the MS. Then the historical media stream is transmitted from the MS to the VCVS. +- 11) After the MS has completed sending the history media stream, it sends a file sending completion message to the CCS. +- 12) The CCS sends the file sending completion message to the VCVS. +- 13) The VCVS sends a 200 OK response to the CCS. +- 14) The CCS sends a 200 OK response to the MS. +- 15) The VCVS sends a BYE request to the CCS. +- 16) The CCS sends a 200 OK response to the VCVS. +- 17) The CCS sends a BYE request to the MS. +- 18) The MS sends a 200 OK response to the CCS (see Note). +- 19) After the media file is obtained, the VCVS starts to process the media data and write the results to the specified storage space. +- 20) When the media data processing is completed, the VCVS returns the service completion message to the CCMS. +- 21) After receiving the service completion message, the CCMS returns the service completion message to the CCS. + +NOTE – The process of the historical media file obtaining initiated by the VCVS, which corresponds to steps 5-18, is the same as that defined in clause 8.8 of [ITU-T H.627]. + +![Sequence diagram showing high-level procedural flows for offline media computing services between MS, CCS, CCMS, and VCVS. The diagram includes 21 numbered steps and a 'Historical media stream' phase. A 'Process' block is shown for VCVS at step 19.](76b0cd79baaedd942af4dc42f2e764b8_img.jpg) + +``` + +sequenceDiagram + participant MS + participant CCS + participant CCMS + participant VCVS + + Note right of VCVS: 19. Process + + CCS->>CCMS: 1. Request offline computing service + CCMS->>VCVS: 2. Request offline computing + VCVS->>CCMS: 3. Request submitted response + CCMS->>CCS: 4. Request submitted response + CCMS->>CCS: 5. Invite (With SDP) + CCS->>MS: 6. Invite + MS->>CCS: 7. 200 OK (With SDP) + CCS->>VCVS: 8. 200 OK (With SDP) + CCS->>CCMS: 9. ACK + MS->>CCS: 10. ACK + Note right of VCVS: Historical media stream + MS->>CCS: 11. Message (File sending completion) + CCS->>VCVS: 12. Message (File sending completion) + CCS->>CCMS: 13. 200 OK + MS->>CCS: 14. 200 OK + CCS->>CCMS: 15. BYE + CCS->>VCVS: 16. 200 OK + MS->>CCS: 17. BYE + MS->>CCS: 18. 200 OK + VCVS->>CCMS: 20. Message (Service completion) + CCMS->>CCS: 21. Message (Service completion) + +``` + +F.743.30(25) + +Sequence diagram showing high-level procedural flows for offline media computing services between MS, CCS, CCMS, and VCVS. The diagram includes 21 numbered steps and a 'Historical media stream' phase. A 'Process' block is shown for VCVS at step 19. + +**Figure 8-6 – High-level procedural flows for offline media computing services** + +## Bibliography + +- [b-ITU-T H.626.3] Recommendation ITU-T H.626.3 (2018), *Architecture for visual surveillance system interworking*. +- [b-ITU-T Y.3500] Recommendation ITU-T Y.3500 (2014), *Information technology – Cloud computing – Overview and vocabulary*. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.743.31-202503-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/F/T-REC-F.743.31-202503-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ac295b1b0c7f14b1c5a33ef6682b1b017c812477 --- /dev/null +++ b/marked/F/T-REC-F.743.31-202503-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:37aed4fc114a39843438175326e0b7e1d09a9d6075723d82fea32040fd560ee4 +size 7192 diff --git a/marked/F/T-REC-F.743.31-202503-I_PDF-E/c0e88e4bd3a209b66ee7cb67e1cec2be_img.jpg b/marked/F/T-REC-F.743.31-202503-I_PDF-E/c0e88e4bd3a209b66ee7cb67e1cec2be_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..27dcee489cda05d5316171d82fdba2521a40e91b --- /dev/null +++ b/marked/F/T-REC-F.743.31-202503-I_PDF-E/c0e88e4bd3a209b66ee7cb67e1cec2be_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:3c842b838b610caba9490c604ed458e3ea4f4dd46dcef62de15a86e162431d94 +size 37275 diff --git a/marked/F/T-REC-F.743.31-202503-I_PDF-E/raw.md b/marked/F/T-REC-F.743.31-202503-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..10e79fda3a05be5943877d4361d463e8b32dfd82 --- /dev/null +++ b/marked/F/T-REC-F.743.31-202503-I_PDF-E/raw.md @@ -0,0 +1,300 @@ + + +# Recommendation + +## **ITU-T F.743.31 (03/2025)** + +SERIES F: Non-telephone telecommunication services + +Multimedia services + +## --- **Requirements for multimedia data asset development and operations** + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.743.31 + +## Requirements for multimedia data asset development and operations + +## Summary + +Recommendation ITU-T F.743.31 specifies the requirements for multimedia data asset development and operation, including data asset development, data asset delivery, multimedia data asset optimization, data asset platform and tools, rules and regulations, as well as security and risk management. + +This Recommendation outlines the multimedia data asset development and operation in enterprises across three stages: asset development, asset delivery, and asset operation. It specifies the key stages and essential requirements involved in the development and operation of multimedia data assets from the perspectives of processes, personnel, tools, and other dimensions. The aim of this Recommendation is to provide guidance for enterprises in constructing their capabilities for the development and operation of multimedia data assets and to enhance the development and operation level of multimedia data assets in the multimedia industry + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.743.31 | 2025-03-16 | 21 | 11.1002/1000/16227 | + +## Keywords + +Data asset, data asset application, data asset catalogue. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2025 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|--------------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 1 | +| 6 Overview ..... | 2 | +| 7 Requirements for multimedia data asset development and operations..... | 3 | +| 7.1 Multimedia data asset development ..... | 3 | +| 7.2 Multimedia data asset delivery ..... | 3 | +| 7.3 Multimedia data asset optimization..... | 4 | +| 7.4 Platforms and tools ..... | 4 | +| 7.5 Rules and regulations ..... | 4 | +| 7.6 Security and risk management..... | 5 | +| Bibliography..... | 6 | + + + +# Recommendation ITU-T F.743.31 + +## Requirements for multimedia data asset development and operations + +## 1 Scope + +This Recommendation specifies overview and requirements of multimedia data asset development and operation, including composition, key stages and essential requirements. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[[ITU-T F.743.21](#)] Recommendation ITU-T F.743.21 (2020), *Framework for data asset management*. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 data asset** [b-ITU-T X.1750]: An electronically recorded data resource, owned or controlled by an organization. + +**3.1.2 data security** [b-ITU-T X.1040]: Preservation of data to guarantee availability, confidentiality and data integrity. + +**3.1.3 data quality** [ITU-T F.743.21]: The integrity, normalization, consistency, accuracy, uniqueness, and relevance of data, which is the premise and guarantee for data mining. + +**3.1.4 data standards** [ITU-T F.743.21]: Normative constraints to guarantee consistency and accuracy of data usage and exchange. + +### 3.2 Terms defined in this Recommendation + +None. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +DataOps Data Operations + +## 5 Conventions + +In this Recommendation, + +- The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted, if conformance to this Recommendation is to be claimed. + +- The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +## 6 Overview + +This Recommendation builds upon the foundational principles outlined in [ITU-T F.743.21], which introduces the concept of data asset management and provides a comprehensive approach to managing data assets across their lifecycle. A multimedia data asset is a special case of data asset containing multimedia information and mainly stored in multimedia form (such as text, pictures, audio, video, three-dimensional panoramic pictures, digital maps.). It is one of the most popular forms of data assets in the industry. + +The multimedia data asset development and operations consists of six key components: multimedia data asset development, multimedia data asset delivery, multimedia data asset optimization, platforms and tools, rules and regulations, as well as security and risk management. By extending these principles to the specific context of multimedia data assets, this Recommendation aims to address the unique challenges and requirements associated with the development and operation of multimedia data assets. + +The overview of the multimedia data asset development and operations is illustrated in Figure 1. To further elaborate on the requirements, the structure has been expanded, as detailed in Figures 2 and 3. Figure 2 focuses on the development process within the data operations (DataOps), while Figure 3 emphasizes the mechanisms integral to ensuring its effective implementation. + +![Figure 1: Overview of multimedia data asset development and operations. The diagram shows a flow from Business requirement to Data asset development, Data asset delivery, and Data asset optimization, leading to Business value. These stages are supported by two foundational pillars: Rules and regulations (top) and Platform and tools / Security and risk management (bottom).](c0e88e4bd3a209b66ee7cb67e1cec2be_img.jpg) + +The diagram illustrates the flow of multimedia data asset development and operations. It starts with 'Business requirement' on the left, which leads into a large grey arrow labeled 'Data asset development'. This is followed by a light green arrow labeled 'Data asset delivery', and then a darker green arrow labeled 'Data asset optimization', which finally points to 'Business value' on the right. Above the arrows, a blue triangle contains the text 'Rules and regulations'. Below the arrows, another blue triangle contains the text 'Platform and tools' and 'Security and risk management'. The reference code 'F.743.31(25)' is visible at the bottom right of the diagram. + +Figure 1: Overview of multimedia data asset development and operations. The diagram shows a flow from Business requirement to Data asset development, Data asset delivery, and Data asset optimization, leading to Business value. These stages are supported by two foundational pillars: Rules and regulations (top) and Platform and tools / Security and risk management (bottom). + +Figure 1 – Overview of multimedia data asset development and operations + +| Capability domains | Data asset development | | Data asset delivery | | | Data asset optimization | | | +|----------------------|------------------------|------------------|--------------------------|-----------------|------------|-------------------------|-------------------|---------------------| +| Capability subdomain | Design management | Data development | Configuration management | Test management | Deployment | Data asset verification | Change management | Data asset disposal | + +F.743.31(25) + +Figure 2 – Process of multimedia data asset development and operations + +| Capability domains | Platform and tools | | | | Rules and regulations | | | Security and risk management | | | +|----------------------|------------------------|---------------------------|---------------------------------|-------------------|------------------------|-----------|---------------|------------------------------|-----------------|------------------| +| Capability subdomain | Data development tools | Continuous delivery tools | Operation and maintenance tools | Data safety tools | Organization structure | Job roles | Collaboration | Security risk strategy | Risk management | Security testing | + +F.743.31(25) + +**Figure 3 – Mechanisms of multimedia data asset development and operations** + +## 7 Requirements for multimedia data asset development and operations + +### 7.1 Multimedia data asset development + +Multimedia data asset development management refers to the standardized management of the multimedia data development process by enterprises, with the aim of building integrated research and development governance process. In the multimedia data development stage, enterprises should establish an integrated process for data research and development governance, shift multimedia data governance work to the left, and organically combine multimedia data governance work with multimedia data development work. This approach can strengthen the collaboration between multimedia data governance and development work, while reducing the risks generated by post multimedia data governance. In addition, strengthening the constraints on multimedia data requirements during the data development stage and utilizing self-analysis to explore or solve some data requirements in advance greatly improves the communication efficiency of multimedia data requirements and reduces the pressure of some research and development work. + +Multimedia data asset development management is required to include the components outlined below: + +- **Design management:** Through the approach of "design before development", ensure the design of data standards and quality in the modelling process. +- **Data development:** Build an integrated development capability for offline, real-time, and data mining, and embed multimedia data quality audit in the development task chain to promptly identify and solve data quality issues. + +### 7.2 Multimedia data asset delivery + +Multimedia data asset delivery management refers to the management process of improving delivery efficiency and quality through automation and standardization of testing, configuration, deployment, and release processes. In the stage of multimedia data delivery and deployment, enterprises strengthen the management of multimedia data version and code quality by building automated testing and delivery pipelines, helping to improve the automation level of data product delivery, accelerate delivery speed, and improve delivery quality. + +Multimedia data asset delivery management is required to include the components outlined below: + +- **Configuration management:** Strengthen version control and environmental management. Manage both code and multimedia data versions to ensure the availability and verifiability of multimedia data at all stages. +- **Test management:** Build an automated testing pipeline, strengthen the management of unit testing and integration testing, test code quality and data multimedia quality, and detect and handle problems in advance. +- **Deployment:** Building an automated deployment and release pipeline to accelerate multimedia data deployment efficiency and reduce human operational risks. + +### 7.3 Multimedia data asset optimization + +Multimedia data asset optimization refers to the process of changing or disposing of inconsistent and cost-optimized multimedia data assets by verifying their accuracy, application volume, input-output ratio, and other information, to optimize the allocation of multimedia data assets. + +Multimedia data asset optimization is recommended to include the components outlined below: + +- **Multimedia data asset verification:** Identify and register multimedia data assets from existing multimedia data resources based on management objectives. Organizations should categorize existing multimedia data resources based on management objectives, identify multimedia data assets and their information elements based on business applications and market demands, and register multimedia data asset information to ensure its accuracy and effectiveness. +- **Change management:** The process of ensuring consistency between multimedia data assets and catalogue information through change control processes. When multimedia data asset management activities or business requirements trigger changes in multimedia data assets, the change management process should be used to ensure the orderly implementation of change management activities, and the multimedia data asset catalogue should be updated in a timely manner to ensure that the information in multimedia data asset catalogue is consistent with the actual situation. +- **Multimedia data asset disposal:** In compliance with relevant laws, regulations, and standards, optimize the allocation of multimedia data assets, reduce operational management costs, and maximize the remaining utilization value through the destruction and transfer of multimedia data assets. + +### 7.4 Platforms and tools + +Platforms and tools refer to agile, automated, and integrated solutions built around multimedia data pipelines. These components serve as a key enabler for enterprises implementing the DataOps concept. They assist internal tool development teams or external vendors in building a complete and mature DataOps toolchain, thereby providing technical support for better ensuring the formation of integrated multimedia data research and development governance for enterprises. + +Platforms and tools are required to include the components outlined below: + +- **Multimedia data development:** Support online code circulation and adhere to the construction principle of "design before development". +- **Continuous delivery:** Support automated testing and deployment pipeline functions, with full version control code and data. +- **Operation and maintenance:** Support monitoring and alarm functions for the entire multimedia data development chain, and display real-time information on research and development efficiency, quality, through large screen displays and other forms. +- **Multimedia data safety:** Establish full chain multimedia data security monitoring and control, implement permission control, sensitive multimedia data desensitization encryption, high-risk operation auditing, and other functions throughout the entire lifecycle of multimedia data development. + +### 7.5 Rules and regulations + +Rules and regulations management refers to the management of the internal organizational structure and roles of an enterprise, with the aim of creating an agile and collaborative data-driven organization. By restructuring the organizational structure, job roles and collaborative mechanisms to support the operation of the DataOps assembly line, the enterprise combines the current situation and development needs, improves the implementation of management norms and requirements, innovates + +the data research and development, management and operation structure, and improves the position and promotion assessment system, thereby providing organizational support for long-term implementation of the DataOps concept and optimization of data development processes. + +Rules and regulations management are recommended to include the components outlined below: + +- **Organizational structure:** Reasonably allocate the internal multimedia data technology architecture and multimedia data personnel architecture of the enterprise. +- **Job role:** Set corresponding job roles, clarify promotion routes and assessment methods. +- **Collaboration:** Relying on agile methods, focusing on collaboration issues between teams and tools, and continuously optimizing them. + +### 7.6 Security and risk management + +Security control refers to the security management of the entire lifecycle of multimedia data research and development. Security measures should be embedded within the multimedia data pipeline, with shared responsibility across delivery stages to improve multimedia data credibility. Ensuring safety is critical to maintaining the normal production and operation of enterprises. By promoting safety awareness throughout the entire lifecycle of multimedia data research and development, enterprises can integrate safety attributes in the process of multimedia data research and development in an agile and comprehensive manner, ultimately reducing safety accidents. + +Security and risk management is required to include the components outlined below: + +- **Security risk strategy:** Strengthen risk identification and prediction throughout the entire lifecycle of multimedia data research and development. Develop risk plans in advance to continuously reduce the impact of risks. +- **Risk management:** Establish and continuously update risk management strategies in alignment with external laws and regulations, regulatory requirements, and internal security needs. +- **Security testing:** Conduct proactive security testing across all phases of the multimedia data development process for early identification and addressing of vulnerabilities. + +## Bibliography + +- [b-ITU-T X.1040] Recommendation ITU-T X.1040 (2017), *Security reference architecture for lifecycle management of e-commerce business data.* +- [b-ITU-T X.1750] Recommendation ITU-T X.1750 (2020), *Guidelines on security of big data as a service for big data service providers.* + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.743.32-202503-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/F/T-REC-F.743.32-202503-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 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+## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.743.36 + +# Requirements for a vehicle recognition application in intelligent video surveillance systems + +## Summary + +Recommendation ITU-T F.743.36 defines the requirements for vehicle recognition application in intelligent video surveillance systems, including requirements for function, service, performance and data security aspects. It also describes typical use cases of vehicle recognition applications. + +The vehicle recognition application, as one typical application of intelligent video surveillance services, performs vehicle related monitoring, detection and recognition based on surveillance images or videos, which is of benefit in vehicle management and traffic planning. This Recommendation provides a reference for the implementation of vehicle recognition application and can be applied in the fields of intelligent transportation, public security and smart city governance. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.743.36 | 2025-12-14 | 21 | 11.1002/1000/16577 | + +## Keywords + +Intelligent video surveillance, requirements, vehicle recognition. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2026 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|--------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 2 | +| 6 Overview..... | 2 | +| 7 Functional requirements ..... | 3 | +| 7.1 Basic functions ..... | 3 | +| 7.2 Vehicle recognition ..... | 3 | +| 7.3 Vehicle plate recognition..... | 4 | +| 7.4 Vehicle speed detection..... | 4 | +| 7.5 Vehicle behaviour detection..... | 4 | +| 7.6 Traffic flow detection..... | 4 | +| 7.7 Vehicle retrieval ..... | 4 | +| 8 Service requirements ..... | 5 | +| 8.1 Basic requirements ..... | 5 | +| 8.2 Advanced requirements ..... | 5 | +| 9 Performance requirements ..... | 5 | +| 10 Data security requirements ..... | 6 | +| Appendix I – Typical use cases..... | 7 | +| I.1 Traffic violation monitoring..... | 7 | +| I.2 Access management ..... | 7 | +| I.3 Traffic flow analysis..... | 8 | +| I.4 Traffic accident perception and emergency response ..... | 9 | +| I.5 Traffic accident prediction ..... | 9 | +| I.6 Traffic environment management ..... | 9 | +| I.7 Marketing insights ..... | 9 | +| Bibliography..... | 10 | + + + +# Recommendation ITU-T F.743.36 + +## Requirements for a vehicle recognition application in intelligent video surveillance systems + +## 1 Scope + +This Recommendation specifies the requirements for vehicle recognition application in intelligent video surveillance systems. The scope of this Recommendation includes: + +- Functional requirements; +- Service requirements; +- Performance requirements; +- Data security requirements; +- Typical use cases. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[[ITU-T H.626.5](#)] Recommendation ITU-T H.626.5 (V2) (2022), *Architecture for intelligent video surveillance systems*. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 application** [b-ITU-T Y.101]: A structured set of capabilities, which provide value-added functionality supported by one or more services. + +**3.1.2 vehicle recognition** [b-ITU-T F.735.1]: Detection of the car in video and extraction of its characteristics. These characteristics may include brand, type, colour, etc. + +### 3.2 Terms defined in this Recommendation + +None. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-----|---------------------------------| +| DSS | Data Storage and Service | +| IAS | Intelligent Application Service | +| ICU | Intelligent Customer Unit | +| IPU | Intelligent Premises Unit | + +| | | +|-----|---------------------------------| +| IVM | Intelligent Video Management | +| IVS | Intelligent Video Surveillance | +| IVU | Intelligent Video Unit | +| LED | Light Emitting Diode | +| VRA | Vehicle Recognition Application | + +## 5 Conventions + +In this Recommendation: + +The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. + +The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus this requirement needs not be present to claim conformance. + +The keywords "can optionally" and "may" indicate an optional requirement which is permissible, without implying any sense of being recommended. These terms are not intended to imply that the vendor's implementation must provide the option and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the Recommendation. + +## 6 Overview + +A vehicle recognition application (VRA) provides the functions of vehicle related monitoring, detection and feature recognition based on surveillance images or videos, via computer vision technology. It is widely applied in fields of intelligent transportation, traffic security and so on. + +A vehicle recognition application can be achieved in an intelligent video surveillance (IVS) system and conforms with the functional architecture defined in [ITU-T H.626.5], as shown in Figure 1. + +The implementation of a vehicle recognition application mainly focuses on the intelligent units of an IVS system, including an Intelligent application service (IAS), intelligent video management (IVM), an intelligent video unit (IVU), data storage and service (DSS), an intelligent premises unit (IPU) and an intelligent customer unit (ICU). The applications of vehicle recognition can be deployed in IAS, an IPU or an ICU, where the relatively simple applications can be achieved by the IPU or ICU while the complicated applications can be achieved by the platform of IVS or the platform combined with IPU/ICU. The IVM and IVU are responsible for configuring strategies and implementing recognition tasks from the platform side. The DSS provides data storage and data service relevant to vehicle recognition application. + +![Functional architecture of IVS system adopted by VRA. The diagram shows a 'VS system' on the right containing 'CCS' (CMU, SCU) and 'MS' (MDU, MSU) blocks, and external blocks 'DSS', 'IAS', 'IVM', 'IVU', 'IPU (PIV)', and 'ICU (CIV)'. Arrows represent Media (black), Control (red), and Video and image information (green) flows between these components. A legend at the bottom defines the arrow types and the orange color for functional units implementing VRA.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +The diagram illustrates the functional architecture of an IVS system. On the right, a dashed box labeled 'VS system' contains two sub-systems: 'CCS' (Communication and Control System) with 'CMU' (Communication Management Unit) and 'SCU' (Storage Control Unit); and 'MS' (Media System) with 'MDU' (Media Distribution Unit) and 'MSU' (Media Storage Unit). External to the VS system are several functional units: 'DSS' (Detection and Surveillance System), 'IAS' (Image Acquisition System), 'IVM' (Image Verification Module), 'IVU' (Image Verification Unit), 'IPU (PIV)' (Image Processing Unit - Personal Image Verification), and 'ICU (CIV)' (Image Control Unit - Control Image Verification). Arrows indicate the flow of information: Media (black), Control (red), and Video and image information (green). The legend at the bottom indicates that orange boxes represent functional units for implementing VRA. + +Functional architecture of IVS system adopted by VRA. The diagram shows a 'VS system' on the right containing 'CCS' (CMU, SCU) and 'MS' (MDU, MSU) blocks, and external blocks 'DSS', 'IAS', 'IVM', 'IVU', 'IPU (PIV)', and 'ICU (CIV)'. Arrows represent Media (black), Control (red), and Video and image information (green) flows between these components. A legend at the bottom defines the arrow types and the orange color for functional units implementing VRA. + +F.743.36(25) + +**Figure 1 – Functional architecture of IVS system adopted by VRA** + +## 7 Functional requirements + +### 7.1 Basic functions + +FUN001: The VRA is required to automatically analyse images and videos captured by IPUs and recognize vehicle related targets contained in them, including motor vehicles and non-motorized vehicles. + +FUN002: The VRA is required to identify the vehicle characteristics from the snapshot images in high-definition resolutions and in commonly used formats. It is recommended to support images with 2 mega pixels, 3 mega pixels, 5 mega pixels or higher and in formats of JPEG, BMP and PNG. + +FUN003: The VRA is required to identify vehicle characteristics from surveillance videos in high-definition resolutions. It is recommended to support videos with resolutions of no less than 720P or 1080P. + +FUN004: The VRA is required to integrate more than one professional algorithm and implement various recognition tasks, including vehicle recognition, trajectory tracking, licence plate recognition, speed detection, behaviour detection and traffic flow detection. It is required to support vehicle recognition in real-time and in non-real-time. + +FUN005: The VRA is required to generate the structured data on vehicle characteristics and store them into the storage unit for retrieval on-demand. It is required to provide the matched retrieval results by importing vehicle characteristics and vehicle images as the search criteria. + +FUN006: The VRA is recommended to generate and optimize vehicle detection models based on the input labelled training dataset. + +FUN007: The VRA is recommended to have anomaly handling and alarming functions, which can automatically process or alert in case of recognition failure, repeated recognition and other abnormal situations. + +### 7.2 Vehicle recognition + +FUN008: The VRA is required to detect the vehicle position in the images and videos. + +FUN009: The VRA is required to identify the vehicle characteristics, including vehicle types, brands, models, size and colours. + +FUN010: The VRA is recommended to support the identification of vehicle types including car, truck, bus, motorcycle, tricycle, electric bicycle and bicycle. It is also recommended to support special vehicle types such as dangerous cargo, ambulance, fire engine and other emergency vehicles. + +FUN011: The VRA is required to identify the multiple vehicles in the images and videos. + +FUN012: The VRA is recommended to perform semantic segmentation to separates the vehicle from the background. It is recommended to detect and cut out each vehicle when there is more than one vehicle in the images. + +FUN013: The VRA is recommended to increase the screen ratio of vehicles for the accurate identification. + +### **7.3 Vehicle plate recognition** + +FUN014: The VRA is required to detect the vehicle and locate the vehicle plate in the images and videos. + +FUN015: The VRA is required to identify the content and the colour of vehicle plate. + +FUN016: The VRA is required to identify all the vehicle plate information when there is more than one vehicle in the images. + +FUN017: The VRA is recommended to detect abnormal cases of licence plates, such as blurry or obstructed. + +### **7.4 Vehicle speed detection** + +FUN018: The VRA is recommended to detect the vehicle speed in the videos. + +### **7.5 Vehicle behaviour detection** + +FUN019: The VRA is required to analyse the vehicle behaviour trail in the videos and identify the abnormal motion and traffic violation of the vehicle, including speeding, driving in the wrong direction and illegal parking. + +### **7.6 Traffic flow detection** + +FUN020: The VRA is required to identify all types of vehicles in the images and videos and count the number of vehicles by vehicle type in a given region of the images. + +FUN021: The VRA is required to count the number of vehicles entering and leaving a designated region of the images. + +FUN022: The VRA is recommended to support dynamic traffic flow statistics by different dimensions such as time segment and geographical region. + +FUN023: The VRA is recommended to support dynamic density statistics by calculating the proportion of the number of target vehicles and the region's area. + +### **7.7 Vehicle retrieval** + +FUN024: The VRA is required to convert the unstructured data of images and videos into structured data of descriptive information on vehicle characteristics, which can accurately be described, understood and queried. + +FUN025: The VRA is required to support feature retrieval and the rapid search of vehicles in a given region. + +FUN026: The VRA is recommended to use any vehicle characteristic as the search criteria including vehicle type, brand, model, vehicle colour, licence plate colour, licence plate number, unregistered vehicles, appearance time and disappearance time. + +FUN027: The VRA is recommended to use a particular image as the search criteria and search out the images with high similarity and sorted by similarity. + +FUN028: The VRA is recommended to support combinatorial search by vehicle characteristic and image. + +## **8 Service requirements** + +### **8.1 Basic requirements** + +SVR001: The VRA is required to support batch importing of images and videos for vehicle detection and recognition. + +SVR002: The VRA is required to render and present images and video streams either from real-time surveillance or recorded media data. It is recommended to support playback service for multiple video streams simultaneously and the capability of caption overlay. + +SVR003: The VRA is required to provide various views for recognition results and retrieval results. It is recommended to support the display of IPUs marked on electronic map, snapshot images or video segments containing target vehicles, capture information and vehicle information. + +SVR004: The VRA is required to support the configuration and management of recognition tasks (see clauses 7.2-7.6). It is required to control the start, stop and distribution of recognition tasks and support configurable strategies such as surveillance region, time period, target object, vehicle characteristic and alarm rules. + +SVR005: The VRA is required to manage its users including the information of username, role, organization and password. It is recommended to classify user levels and allocate operational rights for different levels. + +SVR006: The VRA is required to support log data collection, storage and query. It is required to record user log including the information of user ID, login/logout time, IP address and operation behaviour. It is also required to record an application log including the information of software upgrade/downgrade and running fault. + +SVR007: The VRA is required to be easily upgraded and maintained. + +SVR008: The VRA is required to synchronize time with the IVS system. + +### **8.2 Advanced requirements** + +SVR009: The VRA is recommended to make statistical analysis, generate statistics reports and output or present reports on visualized interface, such as traffic flow reports and traffic violation record reports. + +SVR010: The VRA can optionally support to generate video synopsis containing images or video segments of target vehicles. + +SVR011: The VRA can optionally support rendering and displaying a tracing box overlaid on the target vehicles while displaying their trajectories. + +## **9 Performance requirements** + +PRF001: The VRA is recommended to achieve a recognition time for one image (from trigger to output recognition result) lower than 1 second. + +PRF002: The VRA is recommended to achieve a detection to vehicle target of $120 \times 120$ pixels or higher in images. + +PRF003: The VRA is recommended to simultaneously analyse and process multiple channels of videos in high-definition resolution, such as 16 channels of 1080P video. + +PRF004: The VRA is recommended to support recognition of common vehicle brands. It is recommended to reach a recognition accuracy of no less than 95% in daytime and no less than 90% in nighttime, under the condition of target vehicles with at least $256 \times 256$ pixels in the image. + +PRF005: The VRA is recommended to support the recognition of common vehicle types, including small cars, vans, buses, small lorries, large lorries, SUVs, MPVs and custom vehicle types. It is recommended to reach a recognition accuracy of no less than 95% in daytime and no less than 85% in nighttime, under the condition of target vehicles with at least $256 \times 256$ pixels in the image. + +PRF006: The VRA is recommended to support the recognition of common vehicle body colours, including black, white, grey, red, green, blue, purple, yellow, orange and brown. It is recommended to reach a recognition accuracy of no less than 90% in daytime and no less than 80% in nighttime, under the condition of target vehicles with at least $256 \times 256$ pixels in the image. + +PRF007: The VRA is recommended to support the recognition of vehicle numberplates. It is recommended to reach a recognition accuracy of no less than 95% in daytime and no less than 90% in nighttime, under the condition of target vehicles with at least $256 \times 256$ pixels in the image. + +PRF008: The VRA is recommended to have concurrent processing capability and support at least 100 users accessing the application simultaneously. + +## **10 Data security requirements** + +DSR001: The data from the VRA is required to not be sold, transferred to third parties or disclosed, unless the data subject gives consent. + +DSR002: The VRA is required to inform the users that vehicle information is collected and the purpose and length of term of the data collections needs to be ensured. + +DSR003: The vehicle recognition database is required to be operated by an official mission or organization and to be supervised by independent bodies. + +DSR004: The VRA is required to process and store only the data that is necessary and proportionate to strictly defined purposes. + +DSR005: The VRA is required to support data secure storage and transmission to protect data integrity and secrecy. + +DSR006: The VRA is required to provide mechanisms for authentication and authorization and only permit authorized users to use the application and access the data. + +## Appendix I + +### Typical use cases + +(This appendix does not form an integral part of this Recommendation.) + +With the advancement of urbanization and the increase in vehicle ownership, the needs of vehicle management are constantly increasing, and the development of big data and intelligent detection technology promotes the application of vehicle recognition, typically in fields of intelligent transportation, public security and smart city governance. + +### I.1 Traffic violation monitoring + +The vehicle recognition application analyses vehicle behaviours from surveillance videos and automatically detects traffic violations including illegal parking, speeding and driving in the wrong lane. It recognizes vehicle licence plate and capture traffic violation images as the evidence for a penalty. It can help to maintain public transportation safety. + +Examples are as follows: + +- This application identifies the abnormal behaviours of speeding or driving in the wrong direction. The information of vehicle numberplate and violating behaviour will be shown on an electronic bulletin board on the road to warn vehicles to slow down or drive away. Examples are shown in Figure I.1. +- This application detects vehicles with counterfeit licences, by identifying forgery techniques or tracing vehicle trajectories in time and space and then identifying anomalous behaviours. This will be helpful to maintain the order of public traffic. + +![Two side-by-side surveillance images showing traffic violations. The left image shows a white car driving in the wrong direction on a highway, with a red circle and text 'Driving in the wrong direction'. The right image shows a red car stopped on the shoulder of a highway, with a red circle and text 'Illegal stopping'.](34fccc54a5930cbdf0f07e02c3745e35_img.jpg) + +The image consists of two side-by-side surveillance photographs. The left photograph shows a white car on a multi-lane road, driving away from the camera in a lane that appears to be for oncoming traffic. A red circle highlights the car, and a red callout box with the text "Driving in the wrong direction" points to it. The right photograph shows a red car stopped on the shoulder of a road, with other cars visible in the lanes. A red circle highlights the stopped car, and a red callout box with the text "Illegal stopping" points to it. + +Two side-by-side surveillance images showing traffic violations. The left image shows a white car driving in the wrong direction on a highway, with a red circle and text 'Driving in the wrong direction'. The right image shows a red car stopped on the shoulder of a highway, with a red circle and text 'Illegal stopping'. + +F.743.36(25) + +**Figure I.1 – Examples of abnormal vehicle behaviour** + +### I.2 Access management + +Video surveillance devices such as PUs, LED fill lights or gas flash lamps are deployed near the entrance and exit of a given area. The vehicle recognition application recognizes the characteristics and behaviours of vehicles passing through this area, such as vehicle type, licence plate, motion direction and entry/exit time, and provide a basis for self-service charging. It can help to improve traffic efficiency and intelligent management of certain regions. + +A typical example is at parking lots and toll roads. This application identifies and records information of the vehicles entering or leaving, which is used for automatic payments. An example is shown in Figure I.2. + +![A 3D architectural rendering of a parking lot entrance and exit. A red box highlights the exit area, with a red arrow pointing from the exit towards the entrance, illustrating a potential conflict in traffic flow. Several cars are visible in the parking lot and on the adjacent road.](0dd5ee731e9d7e34e498b5c926110773_img.jpg) + +A 3D architectural rendering of a parking lot entrance and exit. A red box highlights the exit area, with a red arrow pointing from the exit towards the entrance, illustrating a potential conflict in traffic flow. Several cars are visible in the parking lot and on the adjacent road. + +Entering the parking lot from the exit + +F.743.36(25) + +**Figure I.2 – Example of access management in parking lot** + +### **I.3 Traffic flow analysis** + +The vehicle recognition application accurately acquires traffic flow data based on vehicle detection, motion analysis and feature classification within one or more specified video monitoring areas. The real-time monitoring of traffic flow can be used to obtain traffic statistics or traffic patterns that enable traffic planning, scheduling and operation management of traffic across different surveillance regions during different times of the day. It will contribute to traffic efficiency, transportation infrastructure construction and urban planning. + +The examples are as follows: + +- This application analyses traffic flow data of specific road segments or traffic nodes to identify and understand their traffic patterns. An example is shown in Figure I.3. By analysing historical data and long-term traffic variations, this application can further predict the road traffic situation for a given time period in the future. This prediction can be typically applied in driving routes planning for special events, special vehicles (e.g., ambulances, fire engines) or autonomous vehicles. +- This application performs associated analysis and gathers statistics on traffic flow on multiple roads within a certain region and further forms the road traffic models for different time periods in a day. It will provide a basis for the setting of traffic signals and the optimization of traffic signal timing in this region, so as to reduce traffic congestion and improve the overall traffic flow. +- This application monitors and analyses car park traffic flow such as vehicle density and the queuing situation, and provides a basis for the optimization of the parking scheme. + +![A high-angle photograph of a multi-lane road during peak hours. The road is filled with a dense stream of cars, illustrating heavy traffic flow. The vehicles are packed closely together, and the road stretches into the distance under a clear sky.](bf9297824aec2a021ecbad6f70536914_img.jpg) + +A high-angle photograph of a multi-lane road during peak hours. The road is filled with a dense stream of cars, illustrating heavy traffic flow. The vehicles are packed closely together, and the road stretches into the distance under a clear sky. + +**Figure I.3 – Example of traffic flow on a major road** + +### **I.4 Traffic accident perception and emergency response** + +The vehicle recognition application analyses surveillance videos and promptly identifies traffic accidents and their locations. The recognition results will be used to inform the transportation administrative department to start accident handling procedures as soon as possible. It can help to efficiently address traffic congestion issues caused by accidents and enhance the capability of emergency response in transportation field. + +### **I.5 Traffic accident prediction** + +The vehicle recognition application analyses the historical data of traffic accidents and understands their causes and patterns. An updated report of accident-prone roads and their occurrence patterns will be acquired and appropriate measures can be taken to improve traffic safety. It can help to guide the upgradation of road infrastructure and the planning of the urban transportation system. + +### **I.6 Traffic environment management** + +The vehicle recognition application monitors and recognizes the vehicles in motion in a certain area on vehicle types, brands and models and accordingly estimates their emissions. It can be used to assess the impact on environment. To control the emissions within a certain range by this application will contribute to the sustainable development of urban environments. + +### **I.7 Marketing insights** + +Utilizing vehicle recognition data, administrative departments or retail vendors can understand pedestrian flow distribution through vehicle flow. It can help them explore new business opportunities, develop marketing strategies and make business decisions. + +The examples are as follows: + +- Transportation administrative departments can utilize vehicle recognition data to develop a dynamic road pricing policy. This application can provide a reference for their decision on traffic control or traffic revenue. +- When authorized to use vehicle recognition data, retail vendors in a shopping mall or an exhibition can accordingly estimate pedestrian flow distribution and plan their store layout, sales promotions and supplies. + +## Bibliography + +- [b-ITU-T F.735.1] Recommendation ITU-T F.735.1 (2020), *Requirements for software-defined cameras*. +- [b-ITU-T Y.101] Recommendation ITU-T Y.101 (2000), *Global Information Infrastructure terminology: Terms and definitions*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.743.37-202512-I_PDF-E/33a8f3f01dfa8bce75d23017855a13c5_img.jpg b/marked/F/T-REC-F.743.37-202512-I_PDF-E/33a8f3f01dfa8bce75d23017855a13c5_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..659a0e54dae53aafb41a9db63814cbf6a0f94578 --- /dev/null +++ b/marked/F/T-REC-F.743.37-202512-I_PDF-E/33a8f3f01dfa8bce75d23017855a13c5_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:bb1e38a695849d420937335510e276af26b3f1443b3b0412ed193d01c5267f67 +size 30372 diff --git a/marked/F/T-REC-F.743.37-202512-I_PDF-E/562f471e8153729557e6a4ee6343c32c_img.jpg b/marked/F/T-REC-F.743.37-202512-I_PDF-E/562f471e8153729557e6a4ee6343c32c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e66342c9cdcd101c0c7847e4153a740c0cbf15ad --- /dev/null +++ b/marked/F/T-REC-F.743.37-202512-I_PDF-E/562f471e8153729557e6a4ee6343c32c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:1c70e7901fe6be1aa9ace55e00614d506cd11824149bdb49759aa33b0bc4c7b7 +size 70340 diff --git a/marked/F/T-REC-F.743.37-202512-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg b/marked/F/T-REC-F.743.37-202512-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..abda52cbb1047d6649f89e40c898a1c33bed7267 --- /dev/null +++ b/marked/F/T-REC-F.743.37-202512-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:6f3b7e07231c0f3e116c99c493bdda98ecd52313b6735faa6cea23815cf3162b +size 7190 diff --git a/marked/F/T-REC-F.743.37-202512-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg b/marked/F/T-REC-F.743.37-202512-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d05d8349d90ca6cc77deea2602c9afa0d5300a13 --- /dev/null +++ b/marked/F/T-REC-F.743.37-202512-I_PDF-E/76b0cd79baaedd942af4dc42f2e764b8_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:df34522151659ee5d3a287cb7e9f64108b43fecc16ce9885aaaa850ab0c2cbc7 +size 89395 diff --git a/marked/F/T-REC-F.743.37-202512-I_PDF-E/c0e88e4bd3a209b66ee7cb67e1cec2be_img.jpg b/marked/F/T-REC-F.743.37-202512-I_PDF-E/c0e88e4bd3a209b66ee7cb67e1cec2be_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..36df47b37e363db8a9e7b034d11773ffb1b21fe5 --- /dev/null +++ b/marked/F/T-REC-F.743.37-202512-I_PDF-E/c0e88e4bd3a209b66ee7cb67e1cec2be_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:f2f4c6b9e2264211cb5538e9e549d0f6ac5a5ba6cbdfc55e9135bf99a782fd7c +size 72428 diff --git a/marked/F/T-REC-F.743.37-202512-I_PDF-E/raw.md b/marked/F/T-REC-F.743.37-202512-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..aa12b8fa370591fc94b2d16d141b508ada6e284d --- /dev/null +++ b/marked/F/T-REC-F.743.37-202512-I_PDF-E/raw.md @@ -0,0 +1,537 @@ + + +# Recommendation **ITU-T F.743.37 (12/2025)** + +SERIES F: Non-telephone telecommunication services + +Multimedia services + +--- + +## **Requirements and framework for data sharing service networks** + +![ITU logo](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.743.37 + +# Requirements and framework for data sharing service networks + +## Summary + +Recommendation ITU-T F.743.37 includes the overview, scenarios, framework and technical requirements of data sharing service networks. There are diverse scenarios across multiple domains in which data sharing plays a critical role. To make the connection between data providers and demanders easier and more normalized, a general system of data-sharing service networks is needed, whilst a unified and efficient mechanism and standards are needed to support the system. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.743.37 | 2025-12-14 | 21 | 11.1002/1000/16578 | + +## Keywords + +Data sharing service networks, framework, requirements, scenarios. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2026 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-----------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 2 | +| 6 Overview of data sharing service networks..... | 2 | +| 7 Framework of data sharing service networks ..... | 3 | +| 8 Technical requirements of data sharing service networks ..... | 3 | +| 8.1 Delivery service platform ..... | 3 | +| 8.2 Data nodes ..... | 5 | +| 8.3 Process of data sharing service networks ..... | 6 | +| 8.3 Process of data sharing service networks ..... | 7 | +| 9 General requirements of data sharing service networks ..... | 8 | +| 9.1 Network requirements ..... | 8 | +| 9.2 Service quality requirements ..... | 9 | +| 9.3 Security requirements ..... | 9 | +| Appendix I – Use cases of data sharing service networks ..... | 11 | +| I.1 Data delivery of data exchange institutions..... | 11 | +| I.2 Data sharing in the industrial field ..... | 11 | +| Bibliography..... | 13 | + + + +# Recommendation ITU-T F.743.37 + +## Requirements and framework for data sharing service networks + +# 1 Scope + +This Recommendation introduces the basic concepts of data sharing service networks (DSSN), and provides the scenarios and framework of DSSN. + +The scope of this Recommendation includes: + +- An overview of data sharing service networks; +- Scenarios of data sharing service networks; +- Framework of data sharing service networks; +- Technical requirements of data sharing service networks. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following term defined elsewhere: + +**3.1.1 machine learning** [b-ITU-T Y.3172]: Processes that enable computational systems to understand data and gain knowledge from it without necessarily being explicitly programmed. + +NOTE 1 – This definition is adapted from [b-ETSI GR ENI 004]. + +NOTE 2 – Supervised machine learning and unsupervised machine learning are two examples of machine learning types. + +### 3.2 Terms defined in this Recommendation + +None. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|-------------------------------| +| AUC | Area Under Curve | +| DDoS | Distributed Denial of Service | +| DRN | Data Requirement Node | +| DSN | Data Service Node | +| DSP | Delivery Service Platform | + +## 5 Conventions + +- The keywords "is required" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. +- The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement needs not be present to claim conformance. + +## 6 Overview of data sharing service networks + +The data sharing service networks (DSSN) are a framework or system that connects several data providers and data demanders, providing data delivery service (see Figure 1). + +![Figure 1 – Basic concept of data sharing service networks. The diagram illustrates the flow of data from providers to a central DSSN cloud and then to various industry applications. At the top, 'Industry application' icons represent Finance, Internet, Industry, Traffic, Telecom, SmartCity, and Exchange. Below this, a dashed box contains the 'Data sharing service network (DSSN)' cloud. Inside the cloud are three routers and five 'Service node' boxes (two green, one red, two yellow), each with a lock icon. Arrows show data flow from the service nodes through the routers to the industry applications. At the bottom, 'Data provider' icons (databases) are linked to the service nodes, with labels for Finance data, Internet data, Telecommunication data, Industrial data, and Traffic data. A small code 'F.743.37(25)' is in the bottom right.](c0e88e4bd3a209b66ee7cb67e1cec2be_img.jpg) + +Figure 1 – Basic concept of data sharing service networks. The diagram illustrates the flow of data from providers to a central DSSN cloud and then to various industry applications. At the top, 'Industry application' icons represent Finance, Internet, Industry, Traffic, Telecom, SmartCity, and Exchange. Below this, a dashed box contains the 'Data sharing service network (DSSN)' cloud. Inside the cloud are three routers and five 'Service node' boxes (two green, one red, two yellow), each with a lock icon. Arrows show data flow from the service nodes through the routers to the industry applications. At the bottom, 'Data provider' icons (databases) are linked to the service nodes, with labels for Finance data, Internet data, Telecommunication data, Industrial data, and Traffic data. A small code 'F.743.37(25)' is in the bottom right. + +**Figure 1 – Basic concept of data sharing service networks** + +The data sharing service networks (DSSN) establish standardized data access, connect data providers and data demanders, rely on a hierarchical architecture of data nodes, platforms and networks, and build a cross-industry, cross-regional and cross-domain trusted data circulation infrastructure. They provide low-cost, high-efficiency and reliable circulation platform for data exchange, finance, industry and other fields. + +As shown in Figure 1, the customer groups of DSSN are mainly industrial customers, which include data demanders, data providers and data service supporters. Data demanders mainly include large, medium and micro enterprises. The data demanders are the relevant customers that need data analysis, data modelling, data application, and data exchange. Data providers are companies and organizations that provide data resources, Internet data, communication data, and traffic data. Data providers are connected to the DSSN as service nodes to provide data products, models, algorithms, data tools and other services. + +## 7 Framework of data sharing service networks + +Delivery service platform (DSP) is the data sharing platform of DSSN, which realizes data access, task scheduling, reliable ownership and other services (see Figure 2). + +![Figure 2: The framework of data sharing service networks. The diagram shows a 'DSSN' (Data Sharing Service Network) box containing a 'Delivery service platform (DSP)' at the top. Below the DSP, there are three nodes: a 'DRN (Data require node)' on the left, and two 'DSN (Data service node)' units on the right, separated by an ellipsis. Each node contains a 'Management module' and a 'Calculation engine'. Below the DRN is a 'Data demander' connected to a 'Business platform' (represented by a server icon). Below each DSN is a 'Data provider' connected to a 'Data source' (represented by a database icon). The text 'F.743.37(25)' is in the bottom right corner.](562f471e8153729557e6a4ee6343c32c_img.jpg) + +F.743.37(25) + +Figure 2: The framework of data sharing service networks. The diagram shows a 'DSSN' (Data Sharing Service Network) box containing a 'Delivery service platform (DSP)' at the top. Below the DSP, there are three nodes: a 'DRN (Data require node)' on the left, and two 'DSN (Data service node)' units on the right, separated by an ellipsis. Each node contains a 'Management module' and a 'Calculation engine'. Below the DRN is a 'Data demander' connected to a 'Business platform' (represented by a server icon). Below each DSN is a 'Data provider' connected to a 'Data source' (represented by a database icon). The text 'F.743.37(25)' is in the bottom right corner. + +**Figure 2 – The framework of data sharing service networks** + +Data service node (DSN) and data requirement node (DRN) are the data service node and data requirement node of DSSN, which provide different forms of products according to customer needs. DSN is deployed on the data provider side, and DRN is deployed on the data demander side. They consist of management module and calculation engines. + +## 8 Technical requirements of data sharing service networks + +### 8.1 Delivery service platform + +#### 8.1.1 Customer management + +Customer management is required as follows: + +- a) Support the addition, reduction, modification and access of data demander/provider; +- b) Support the identification, authentication and legitimacy verification of the data demander/provider; +- c) Support permission setting and management of different roles of data demander/provider. + +#### 8.1.2 Node management + +Node management is required as follows: + +- a) Node registration and logoff, which establish approval mechanism of node entry and exit. + - 1) Data providers and demanders register as users on the DSP and then create data nodes, and the registration information of the node includes the information of the node's ownership organization, the IP of the computing node, the node type, the authentication method. + - 2) Necessary information is sent to data nodes, including registration permission information and corresponding configuration information, and registration authentication failure information. + - 3) Network policy and computing power resources are allocated after node registration. +- b) Support unified access and mutual trust authentication of engines and components among data nodes in DSP. Engines and components of DSN and DRN can be downloaded and installed after registration. Installation and configurations information synchronizes to DSP. + +- c) Support the deactivation of DSN/DRN if they have no need to use; DSN and DRN is unable to log in to the DSP after the node closed. +- d) Support the monitoring of data nodes status on DSP, including the monitoring of data node connection, data traffic, resource occupation, job load, job success rate and other indicators. DSN/DRN supports monitoring interfaces, uploads monitoring information to DSP, and refreshes data periodically. + +#### **8.1.3 Resource management** + +Resource management is required as follows: + +- a) Support broadcasting information of resources to other participants when resources are renewed; +- b) Support authenticating resource authority, validity and integrity; +- c) Support resource search, view and permission configuration; +- d) Support the collection of resource invocation information by data nodes. + +#### **8.1.4 Delivery management** + +Delivery management is required as follows: + +- a) Support multiple data products for delivery, such as data sets, application programming interfaces (APIs), report, model; +- b) Support process recording of data delivery; +- c) Support the authorized viewing, use, and export of data products; +- d) Support version management of data products. + +#### **8.1.5 Billing service** + +Billing service is required as follows: + +- a) Support online and offline billing functions. +- b) Support the calculation and collection of billing information based on the billing rules agreed upon by both DSN and DRN. +- c) Support DRN and DSN in sending billing requests to DSP, with billing task identification attached. +- d) Support DSP in initiating billing tasks based on billing requests, and completing bill consolidation and account balance updates according to billing information. +- e) Support DSP in generating bills and sending notifications to data demanders and data providers. +- f) Support viewing the bill list. +- g) Support choosing a payment method for unpaid orders. + +#### **8.1.6 Operation analysis management** + +Operation analysis management is recommended as follows: + +- a) Support statistical analysis of data resource, task orders, delivery schedule and so on. +- b) Support statistical analysis of different time dimensions, such as months or years. +- c) Support the display of different data analysis results according to different roles. +- d) Support synchronizing the results of data analysis to the industry application platforms. + +### **8.2 Data nodes** + +#### **8.2.1 Management module** + +##### **8.2.1.1 Node management** + +Node management is required as follows: + +- a) Support the synchronization of node information from DSP to DSN/DRN, and the display of basic information, including the information of the node's ownership organization, the IP of the computing node, the node type and the authentication method; +- b) Support network authentication and interconnection between cooperating nodes; +- c) Support a verification mechanism and access authorization during job execution. + +##### **8.2.1.2 Engine management** + +It is required to support the registration and deregistration of different computing engines. + +##### **8.2.1.3 Dataset management** + +Dataset management is required as follows: + +- a) Support the creation of data resources and their publication to DSP for DSN; +- b) Support querying and displaying dataset information; +- c) Support datasets checking and deletion; +- d) Support dataset anonymization; +- e) Support dataset quality evaluation. + +##### **8.2.1.4 System management** + +System management is required as follows: + +- a) Support managing users of the system, with different users have different access rights; +- b) Support measurement of different services and operations, and measurement information needs to be synchronized to DSP; +- c) Support management of data node operation logs. + +#### **8.2.2 Calculation engine** + +##### **8.2.2.1 Basic calculation** + +Basic calculation in data nodes includes data processing and analysis task on the calculation engine. Basic calculation is recommended as follows: + +- a) Support data acquisition and writing from different types of data sources; +- b) Support authentication and access mechanisms for different data sources; +- c) Support multi-node collaborative computing tasks; +- d) Support authorization, loading, configuration and invocation of different algorithms and models; +- e) Support initiation, scheduling and monitoring of computing tasks; +- f) Support dynamic expansion of computing power to meet the expansion of tasks; +- g) Support multiple data formats, such as tables, documents; +- h) Support functions including segmentation and sampling of joint data, data cleaning, data preprocessing, data conversion, numerical operation, logical operation, unit operation, statistical analysis and calculation; +- i) Support the use of missing-value preprocessing algorithm to preprocess the original data set; + +- j) Support quality evaluation of original data sets and data directories in DSN; +- k) Support anonymizing original data directories using a data processing algorithm if quality evaluation results satisfy system requirements. + +##### **8.2.2.2 Federated modelling** + +Federated modelling refers to modelling with data from multiple parties and federated learning algorithms, which is recommended as follows: + +- a) Support federated feature engineering, including data cleaning, feature-free dimensionalization, feature partitioning, and feature coding; +- b) Support several federated modelling algorithms, including logistic regression, linear regression, decision tree, XGBoost, and LightGBM; +- c) Support federated prediction and output of correct prediction results, including loss, area under curve (AUC), accuracy, F1 score; +- d) Support a process mechanism for algorithm combination execution; +- e) Support the prevention of leakage of original data. + +##### **8.2.2.3 Multiparty computing** + +Multiparty computing is recommended as follows: + +- a) Support common secure computing protocols, including password sharing, casual transmission, homomorphic encryption, and obfuscated circuit; +- b) Support calculating the intersection of multiple parties' data without disclosing the original data; +- c) Support the hidden query mode, where the enquirer obtains the query result without exposing their query input. + +### **8.3 Process of data sharing service networks** + +#### **8.3.1 System deployment** + +DSSN is deployed before data delivery, and is required to include the following parts: + +- a) Customer registration: customers complete the account registration in the DSP, or the industry application platform transmits the customer information to the DSP. +- b) Installation and deployment: customers download the DSN/DRN installation package from DSP, complete the installation and activation, and install the required algorithms and computing engines on DSN/DRN. +- c) Data directory release: DSNs perform data preprocessing, evaluate data quality, anonymize original data directory using the installed algorithms. Anonymous data directories are uploaded to DSP and checked by DRN. DSN uploads the original data directory to DSP after DSP sends the requirement. Original data directory can be viewed by DSNs and DRN only if the data demander is authorized by DSP and sent to the DRN for viewing. + +#### **8.3.2 Project execution** + +Project execution of DSSN is required to include the following parts: + +- a) Node access: DSP authenticates DRN and receives the access service request initiated by the node after passing the authentication, wherein the access service request carries the permission information assigned by DSP to the DRN and the service information initiated by the DRN. +- b) Project creation: the data demander initiates a project on DSP and sends project order to DRN. DRN creates the project according to the project order information. + +- c) Node matching: Based on the permission information and service information of DRN, DSP searches for at least one DSN that meets the matching conditions in the node database. +- d) Candidate node confirmation: DSP sends a service notification message to DSN, in which the service notification message carries the node information of DRN; DSN generates and returns a service response message to DSP based on the received service notification message. DSP sends a service response message to DRN, in which the service response message carries at least the node information of DSN. +- e) View directory: the data demander views candidate DSNs and corresponding data directory in DSP, selects the DSNs and corresponding data sets according to the project information, and accesses the data. +- f) Data request: DRN sends data usage request to DSP, the request includes information about data set, data provider and computing. +- g) Job request: After the approval of the project order, DRN initiates a job request to each DSN through DSP. DRN sends a job request about computing between DRN and one or more DSNs to DSP. DSP receives the job request and gives permission to the right DSN. The request information includes information on demanding data sets, computing engines, algorithms information, etc. +- h) Algorithm packages download: DRN/DSN sends a request for algorithm download based on the algorithm information required for the job request to DSP, in order to get the algorithm packages which can be used in computing, DRN/DSN receive algorithm packages from DSP. +- i) Job initiation: DRN starts a job and jointly executes the job with DSN, such as federated modelling, multi-party secure calculation, private information retrieval, algorithm running, parameter aggregation. DRN and DSN synchronize the job status to DSP while the job executes. +- j) Job completion: After the job finishes, DRN gets the computing results directly from DSNs, except in private information retrieval. In this case, DSNs send the computing results to DSP, then DSP sends computing results to DRN. +- k) Job orders: DSP generates billing information according to the completion status of the job order, synchronizes it to the industry application platform, and the data demander pays the bill. + +### 8.3 Process of data sharing service networks + +#### 8.3.1 System deployment + +DSSN is deployed before data delivery, and is required to include the following parts: + +- a) Customer registration: customers complete the account registration in the DSP, or the industry application platform transmits the customer information to the DSP. +- b) Installation and deployment: customers download DSN/DRN installation package from DSP, complete the installation and activation, and install the required algorithms and computing engines on DSN/DRN. +- c) Data directory release: DSNs make data preprocessing, evaluate data quality, anonymize the original data directory by the installed algorithms. Anonymous data directories are uploaded to DSP and checked by DRN. DSN uploads the original data directory to DSP after DSP sends requirement. The original data directory can be viewed by DSNs and DRN only if data demander is authorized by DSP and sent to the DRN for viewing. + +#### 8.3.2 Project execution + +Project execution of DSSN is required to include the following parts: + +- a) Node access: DSP authenticates DRN and receives the access service request initiated by the node after passing the authentication, wherein the access service request carries the permission information assigned by DSP to the DRN and the service information initiated by the DRN. +- b) Project creation: the data demander initiates a project on DSP and sends a project order to DRN. DRN creates the project according to the project order information. +- c) Node matching: Based on the permission information and service information of DRN, DSP searches for at least one DSN that meets the matching conditions in the node database. +- d) Candidate node confirmation: DSP sends a service notification message to DSN, in which the service notification message carries the node information of DRN; DSN generates and returns a service response message to DSP based on the received service notification message. DSP sends a service response message to DRN, in which the service response message carries at least the node information of DSN. +- e) View directory: the data demander views candidate DSNs and corresponding data directories in DSP, selects the DSNs and corresponding data sets according to the project information, and accesses the data. +- f) Data request: DRN sends a data usage request to DSP, the request includes information about the data set, data provider and computing. +- g) Job request: After the approval of the project order, DRN initiates a job request to each DSN through DSP. DRN sends a job request about computing between DRN and one or more DSNs to DSP. DSP receives the job request and gives permission to the right DSN. The request information includes information on demanding data sets, computing engines, algorithms information, etc. +- h) Algorithm packages download: DRN/DSN sends a request for algorithm download based on the algorithm information required for the job request to DSP, in order to get the algorithm packages which can be used in computing, DRN/DSN receives algorithm packages from DSP. +- i) Job initiation: DRN starts a job and jointly executes the job with DSN, such as federated modelling, multi-party secure calculation, private information retrieval, algorithm running, parameter aggregation. DRN and DSN synchronize the job status to DSP while the job executes. +- j) Job completion: After the job finishes, DRN gets the computing results directly from DSNs, except in private information retrieval. In this case, DSNs send the computing results to DSP, then DSP sends computing results to DRN. +- k) Job orders: DSP generates billing information according to the completion status of the job order, synchronizes it to the industry application platform, and the data demander pays the bill. + +## 9 General requirements of data sharing service networks + +### 9.1 Network requirements + +DSSN is built based on existing transport and bearing network resources, ensuring the security of data transmission and the quality of service. The network is recommended as follows: + +- a) Support the reuse of customers' existing network access lines according to the customers' needs, and opening of new dedicated lines, including but not limited to Internet dedicated lines, and data dedicated lines; + +- b) Support services with different bandwidth, latency, reliability, port changes, and SLA level guarantees; +- c) Support multi-party mesh interconnection services; +- d) Support cross-regional private network and intra-regional private network activation services. + +### **9.2 Service quality requirements** + +Service quality is recommended as follows: + +- a) Support data quality supervision, real-time monitoring, regular evaluation and comprehensive evaluation of the quantity, quality and update of shared data on DSP; +- b) Support data quality management, build data quality evaluation system, and form data quality monitoring and early warning mechanism and closed-loop problem processing mechanism on DSN; +- c) Support the sorting, cleaning, desensitization, format conversion and other processing of shared data, and update the data in time according to the agreed update frequency on DSN. + +### **9.3 Security requirements** + +#### **9.3.1 Business security requirements** + +Business security is recommended as follows: + +- a) Support the use of passwords or digital signatures to verify the identity and qualifications of DSN and DRN, intercept illegal user login requests, and provide handling measures in case of login failure; +- b) Support the review and approval of registration/networking applications for DSN and DRN; +- c) Support permission management based on access control policies such as identity, role, attribute, and intercept illegal data access requests; +- d) Support hierarchical classification of user permissions for DSN and DRN, and clarify the scope and purpose of data use; +- e) Support the destruction of data stored locally in the system after data sharing; +- f) Support recording system logs, operation logs, and security logs, and conduct regular security audits. Audit records are stored independently and cannot be modified or deleted; +- g) Support security processing of contracts and transaction orders (such as encrypted storage and desensitisation); +- h) Support security processing of third-party interface calls (such as third-party auditing and payment interfaces). + +#### **9.3.2 Data security requirements** + +Data security is recommended to support the following: + +- a) Support ensuring that personal information subjects in shared data on DSN cannot be identified or associated, and that sensitive information needs to be anonymized; +- b) Support ensuring that incoming data, algorithm components, and resources can be accessed only after authorization, and that the access permissions for process and result data must comply with the agreement between the participants; +- c) Support distributed storage and backup methods to ensure data storage security, and perform hierarchical storage of original data, intermediate data and result data to ensure the independence between original data and result data; + +- d) Support the storage of data summaries, key data operations, operating entities, and data logs to ensure traceability; +- e) Support monitoring of the whole data life cycle, including but not limited to data collection, transmission, storage, processing, exchange, use and destruction; +- f) Support encryption processing and key management for data transmission, calculation, and interaction; +- g) Support classifying data security levels and providing corresponding encryption functions. + +#### **9.3.3 Communication security requirements** + +Communication security is recommended to support the following: + +- a) Support encrypted transmission to ensure the security of network transmission channels, including data transmission channel encryption and data encryption, encryption methods; +- b) Support IP access/user access security authentication modes, requiring no less than two authentication modes for authentication, at least one of which is implemented using password technology; +- c) Support the system in detecting network attacks such as distributed denial of service (DDoS), and taking measures to ensure the normal operation of the network system. + +## Appendix I + +### Use cases of data sharing service networks + +(This appendix does not form an integral part of this Recommendation.) + +### I.1 Data delivery of data exchange institutions + +A data exchange institution is a centralized platform used for the buying, selling, sharing, and circulation of data under compliance and security requirements. DSSN provides secure and trusted data delivery services, as shown in Figure I.1. + +![Diagram of data delivery process involving Data exchange/Public data operation platform, Data provider, Data demander, and DSSN.](33a8f3f01dfa8bce75d23017855a13c5_img.jpg) + +The diagram illustrates the data delivery process. At the top is a box labeled 'Data exchange/Public data operation platform'. Below it, on the left, is a box labeled 'Data provider' and on the right, a box labeled 'Data demander'. At the bottom center is a box labeled 'DSSN'. A large blue circle connects the 'Data provider' and 'Data demander' boxes. Three numbered arrows indicate the flow: 1. 'Dealmaking' from the 'Data provider' to the 'Data demander' along the top arc of the circle; 2. 'Data delivery standard calling' from the 'Data exchange/Public data operation platform' down to the 'DSSN' box; 3. 'Data delivery' from the 'DSSN' box to the 'Data demander' along the bottom arc of the circle. The label 'F.743.37(25)' is located to the right of the 'DSSN' box. + +Diagram of data delivery process involving Data exchange/Public data operation platform, Data provider, Data demander, and DSSN. + +**Figure I.1 – Data delivery of data exchange institutions** + +DSSN connects data demanders and data providers based on transaction orders. DSSN realises the data delivery by agreed calculation, transmission, interaction and other means. The delivery results are returned to the exchange institution to support the completion of the transaction. + +DSSN provides computing networks perception and scheduling, bandwidth and traffic prediction, delay monitoring, quality of service (QoS) guarantee, security isolation and other services to meet the delivery quality of service with different priorities and ensure the reliability of data circulation transactions. + +DSSN provides data delivery certificates and compliance control services, and realises the traceability of the whole process of data delivery. + +DSSN provides transaction support tools such as data quality assessment, value assessment, and multi-dimensional billing, which can help trading institutions reduce the technical threshold of data trading and promote the whole process of data trading to be more secure and efficient. + +### I.2 Data sharing in the industrial field + +In the industrial field, industrial data are gradually transforming from a by-product of the manufacturing process into a strategic resource that brings new value to enterprises and supply chain links, becoming a key factor in enhancing manufacturing productivity, competitiveness, and innovation capability (see Figure I.2). + +![Diagram illustrating data sharing in the industrial field through a central DSSN. It shows four entities: Company A (Device data), Company A (Marketing data), Supplier B (Production data), and Supplier B (Sales data). Each entity has its own data system and computing units connected to a central network of nodes labeled DSSN. A yellow dashed box encloses the two Company A entities, and a blue dashed box encloses the two Supplier B entities.](76b0cd79baaedd942af4dc42f2e764b8_img.jpg) + +The diagram illustrates a data sharing architecture centered around a **DSSN** (Data Sharing Network). At the center is a mesh network of nodes labeled **DSSN**. Four entities are connected to this central network via bidirectional arrows: + +- Company A (Device data)**: Located in the top-left, it contains a **Data system** (represented by a database icon) and **Computing units** (represented by server icons). +- Company A (Marketing data)**: Located in the top-right, it also contains a **Data system** and **Computing units**. This entity is enclosed in a yellow dashed box. +- Supplier B (Production data)**: Located in the bottom-left, it contains a **Data system** and **Computing units**. +- Supplier B (Sales data)**: Located in the bottom-right, it contains a **Data system** and **Computing units**. This entity is also enclosed in a yellow dashed box. + +The two **Company A** entities are grouped together by a yellow dashed box, and the two **Supplier B** entities are grouped together by a blue dashed box. The text **F.743.37(25)** is visible in the bottom right corner of the diagram area. + +Diagram illustrating data sharing in the industrial field through a central DSSN. It shows four entities: Company A (Device data), Company A (Marketing data), Supplier B (Production data), and Supplier B (Sales data). Each entity has its own data system and computing units connected to a central network of nodes labeled DSSN. A yellow dashed box encloses the two Company A entities, and a blue dashed box encloses the two Supplier B entities. + +**Figure I.2 – Data sharing in the industrial field** + +However, industrial data faces risks such as poor circulation, information leakage, and excessive use. While protecting the privacy and security of industrial data, enterprises and their upstream and downstream suppliers can leverage the DSSN to achieve data fusion within production lines and factories, enable cross-domain data sharing within enterprises, and realize trusted data circulation among enterprises, thereby promoting the value release of industrial data. + +## Bibliography + +- [b-ITU-T Y.3172] Recommendation ITU-T Y.3172 (2019), *Architectural framework for machine learning in future networks including IMT-2020*. +- [b-ETSI GR ENI 004] ETSI GR ENI 004, V2.2.1 (2021), *Experiential Networked Intelligence (ENI); Terminology for Main Concepts in ENI*. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.743.5-201808-I_PDF-E/1d7527f4316cfe2d342b08d1653d1592_img.jpg b/marked/F/T-REC-F.743.5-201808-I_PDF-E/1d7527f4316cfe2d342b08d1653d1592_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e833b57236e86b7d4a316962451f15c987da0559 --- /dev/null +++ b/marked/F/T-REC-F.743.5-201808-I_PDF-E/1d7527f4316cfe2d342b08d1653d1592_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:458648899db3b571932f7abfaebc00a85dcc4bf58d2b407601a08107f5f55fb0 +size 6997 diff --git a/marked/F/T-REC-F.743.5-201808-I_PDF-E/7e670a2b556b53ea9002dfff3a420e08_img.jpg b/marked/F/T-REC-F.743.5-201808-I_PDF-E/7e670a2b556b53ea9002dfff3a420e08_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..299374a47d81d96146b3ca64deb5bbce676f9bf7 --- /dev/null +++ b/marked/F/T-REC-F.743.5-201808-I_PDF-E/7e670a2b556b53ea9002dfff3a420e08_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:4827d697824d2e016dab904b28c2fae535b659d9f140d756948b8c95d8949741 +size 101319 diff --git a/marked/F/T-REC-F.743.5-201808-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg b/marked/F/T-REC-F.743.5-201808-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ba275de21a822c6a6549d7c8bb9b118f24d2b856 --- /dev/null +++ b/marked/F/T-REC-F.743.5-201808-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:9c55c0ee20c8eb890267057ea45c6e7ad9a62ff0616df780509da1bd8ea821ba +size 66483 diff --git a/marked/F/T-REC-F.743.5-201808-I_PDF-E/raw.md b/marked/F/T-REC-F.743.5-201808-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..8021fc1553e4523f9ab4b80b5fdec66d5529ae27 --- /dev/null +++ b/marked/F/T-REC-F.743.5-201808-I_PDF-E/raw.md @@ -0,0 +1,404 @@ + + +International Telecommunication Union + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**F.743.5** + +(08/2018) + +SERIES F: NON-TELEPHONE TELECOMMUNICATION +SERVICES + +Multimedia services + +--- + +**Framework and interfaces for multimedia +content delivery network** + +Recommendation ITU-T F.743.5 + +ITU-T + +![ITU logo](1d7527f4316cfe2d342b08d1653d1592_img.jpg) + +The logo of the International Telecommunication Union (ITU) features a stylized globe with a red lightning bolt striking across it. The letters 'ITU' are prominently displayed in blue. + +ITU logo + +International +Telecommunication +Union + +# ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** --- + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multidestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| MULTIMEDIA SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.743.5 + +# Framework and interfaces for multimedia content delivery network + +## Summary + +Recommendation ITU-T F.743.5 describes the challenges of traditional Internet protocol television (IPTV), dedicated content delivery networks (CDNs) and the design goals of the multimedia CDN. It also defines the functional framework of multimedia CDN and the logical interfaces among its functional components. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.743.5 | 2018-08-29 | 16 | 11.1002/1000/13656 | + +## Keywords + +Content delivery network (CDN), framework, interface, multimedia. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2018 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-----------------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation ..... | 1 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Challenges in conventional CDNs..... | 3 | +| 6.1 Multiple service adaptations..... | 3 | +| 6.2 Multiple CPs/SPs management ..... | 3 | +| 6.3 The efficiency of resource utilization..... | 3 | +| 6.4 CDN over various networks ..... | 3 | +| 7 Design goals..... | 3 | +| 7.1 The unified content/service management ..... | 4 | +| 7.2 Capability for flexible resource management..... | 4 | +| 7.3 Capability for interworking between networks ..... | 4 | +| 8 Framework for multimedia content delivery network ..... | 4 | +| 8.1 Overview ..... | 4 | +| 8.2 The functional framework for multimedia CDN ..... | 5 | +| 9 High-level interfaces..... | 6 | +| 9.1 Interfaces between CDN service scope and other service scope..... | 7 | +| 9.2 Inner interfaces between CDN functions ..... | 8 | +| Bibliography..... | 9 | + + + +# Recommendation ITU-T F.743.5 + +## Framework and interfaces for multimedia content delivery network + +# 1 Scope + +This Recommendation defines the functional framework and interfaces for multimedia content delivery networks (CDNs). + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T Y.2019] Recommendation ITU-T Y.2019 (2010), *Content delivery functional architecture in NGN*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 content** [b-ITU-T H.780]: A combination of audio, still image, graphic, video, or data. + +**3.1.2 content delivery network** [b-ITU-T Y.2084]: A content delivery network (CDN) is a system of distributed servers that deliver content (e.g., web pages, files, videos and audios) to users based on pre-defined criteria such as the geographic locations of users, the status of the content delivery server and the IP network connection. + +**3.1.3 delivery** [b-ITU-T X.609]: The procedures and means employed to provide a user with the required archived material for reuse. + +**3.1.4 overlay network** [b-ITU-T X.1162]: An overlay network is a virtual network that runs on top of another network. Like any other network, the overlay network comprises a set of nodes and links between them. Because the links are logical ones, they may correspond to many physical links of the underlying network. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 content delivery network (CDN) provider**: The special organization or company in charge of providing the infrastructure needed to deliver the content service provider's (CSP) contents to the end users in real time mode. + +**3.2.2 content delivery network (CDN) service**: The service provided by service providers (SPs) or content delivery network (CDN) vendors/providers with the capability to distribute and deliver the content from content source to the destination by using CDN facilities. + +**3.2.3 distribution**: The unidirectional flow of information from a given point in the network to other (multiple) locations. + +**3.2.4 dynamic content:** Contents created on demand while a user dynamically operates a web application. + +**3.2.5 static content:** Content that changes infrequently. This type of content is not changed with the requests of users. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|---------------------------------| +| CDN | Content Delivery Network | +| CDNi | CDN interconnection | +| CP | Content Provider | +| CSP | Content Service Provider | +| I/O | Input/Output | +| IP | Internet Protocol | +| IPTV | Internet Protocol Television | +| NFV | Network Function Virtualization | +| OTT | Over The Top | +| QoS | Quality of Service | +| SDN | Software-Defined Networking | +| SLB | Service Load Balance | +| SP | Service Provider | +| URL | Uniform Resource Locator | +| VCDN | Virtual CDN | + +# **5 Conventions** + +In this Recommendation: + +The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. + +The keywords "is prohibited from" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. + +The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus this requirement need not be present to claim conformance. + +The keywords "is not recommended" indicate a requirement which is not recommended but which is not specifically prohibited. Thus, conformance with this specification can still be claimed even if this requirement is present. + +The keywords "can optionally" indicate an optional requirement which is permissible, without implying any sense of being recommended. This term is not intended to imply that the vendor's implementation must provide the option and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the specification. + +# **6 Challenges in conventional CDNs** + +## **6.1 Multiple service adaptations** + +The conventional content delivery network (CDN) is usually designed for a dedicated service, such as Internet protocol television (IPTV) and web cache. Software features or hardware capabilities are designed to support dedicated service logic, the media content format, the business model and the terminal device type. Once the design goal is achieved, service deployment, configuration and maintenance are difficult to change. Usually, CDNs for different services are independent of each other, which results in poor interactivity between them. + +Another problem related to multiple service adaptation is service deployment and promotion. Usually, the speed of service process in the conventional CDN relies on the capacity of the dedicated hardware/software. With the development of content formats, protocols and equipment lifecycles, the CDN providers or CDN vendors need to increase their investments to either replace or upgrade the hardware or software. + +## **6.2 Multiple CPs/SPs management** + +From the perspective of the CDN providers, if they want to provide the service to multiple content providers (CPs) or service providers (SPs), they need to assign a specific CDN resource for each of them. However, different CP/SPs have their own service requirements, such as different network, storage and computing requirements. When the content is being distributed in the network, the management policy may also be different according to the specifics CP/SP requirements. Therefore, CDN providers should prepare the corresponding CDN software version to harmonize the purpose, which may also increase needed investments. + +## **6.3 The efficiency of resource utilization** + +Clause 6.2 mentions that CDN resources are allocated to different CPs/SPs according to their demands. In fact, because of many factors, those resources cannot be used efficiently. For example, the device capability is typically designed for coping with the demands of peak time use, and those resources cannot then be used efficiently during normal times, nor can they be released for other uses. In multiple services scenarios, demands for resource utilization are varied, and the system capacity design should be able to match the demands, which increases the system complexity. Moreover, because the resources are running on dedicated hardware/software, resources migration and adjustments are not easy to implement and are limited by the dedicated system design. + +## **6.4 CDN over various networks** + +Conventional CDNs have different architectures and service logics that correspond to different networks, including mobile and fixed networks. Each network has its own regulation of routing, distribution and delivery. However, in the current market, a service, maybe with various content formats, is required to be able to be deployed over multiple types of networks. The interworking between networks is not performed well. Therefore, for different CDN providers, the CDN designed for each type of network has this weakness. The consequence is that content cannot be distributed in all types of CDNs unless the content is transformed into multi-types of content formats. As mentioned in clause 6.3, upgrades of this sort will require additional investments on the part of CDN service providers. + +# **7 Design goals** + +Clause 6 describes the challenges of conventional CDNs developed with technical and marketing requirements. Correspondingly, a multimedia content delivery network should incorporate the following features into its design goals. Future CDN goals are summarized as follows: + +## 7.1 The unified content/service management + +Multimedia CDN may need to deal with various services, content formats and network capacities within different scenarios. To guarantee that all those services and content can be identified, located and managed appropriately, a unified service and content management platform is recommended. In addition, the related network topology, traffic monitoring and CDN nodes load balance are required to be managed in a unified management system. + +## 7.2 Capability for flexible resource management + +The development of flexible resource management will lead to the separation of software resources and hardware sources. The advantage of this separation could bring at least two benefits: + +- 1) All resources can be centralized and located globally. The software does not need to be running on dedicated hardware. It can be reserved, utilized and reclaimed based on the requirements. This benefits greatly the software deployment, configuration and promotion. +- 2) The CDN node capability can be enhanced to support more content formats and service types by dynamically adjusting its resources. This is particularly good for operators wanting to reduce their investments. + +The design objective for flexible resource management can be achieved by adopting network virtualization technology and software-defined network technology. The detailed information can be referenced from the related ITU-T Recommendations listed in the Bibliography. + +## 7.3 Capability for interworking between networks + +Currently, the dedicated CDN does not meet the requirements of comprehensive network integration. The CDN should be able to cover two or more network types. The interworking is the baseline for unified network management and interoperability between different networks. Also, it will guarantee content transmission across the different networks. From feedback offered by end-users, the CDN provides for the possibility of using different terminal devices and obtaining a better consumer experience. + +# 8 Framework for multimedia content delivery network + +This clause describes the functional framework for multimedia CDN and the functional blocks of multimedia CDN framework. [ITU-T Y.2019] is an important reference for this clause. + +## 8.1 Overview + +A CDN is an infrastructure of network elements operating at layer 4 through layer 7. Usually, a conventional CDN is a service-oriented overlay network built on the underlying transport network. According to requests made by users or content providers, the major service of CDN in the past years is to distribute and deliver digital content (web pages and images) to the place that is nearest to the end-point. With the development of multimedia services and network infrastructures, CDN is now widely used in dedicated networks for carrying Internet protocol (IP) based video/audio transportation. For example, IPTV is a quality of service (QoS) guaranteed service that takes great advantage from CDN. + +In the real market, CDN is designed for varying purposes and is operated by different operators or service providers, which requires a dedicated CDN functional architecture. Those CDNs are usually isolated from each other, e.g., an IPTV CDN and an Internet CDN for over the top (OTT) service. Because of the different purposes such as the distribution of dynamic content or static content, CDNs may be designed by different architectures to support diverse media formats, transport protocols and receivers. More and more users expect to access various services using a single terminal device or expect to switch between different terminal devices with a high-speed service response and without + +knowledge of the network infrastructure. The current CDN lacks interoperability, the ability to support multiple types of services and uses resources inefficiently. + +Therefore, a CDN needs to be developed as an ideal solution for supporting various service types, content formats, transport protocols and interoperability. + +Many emerging technologies can be applied in the multimedia CDN such as virtualized CDN, network function virtualization/software-defined networking (NFV/SDN), CDN interconnection (CDNi) and smart content/user request routing. But the basic concept of CDN still comes from the conventional CDN that can be found in [ITU-T Y.2019]. The basic CDN functions can be shown as four parts: Content distribution and control functions, content delivery functions, management functions and content routing/redirection functions. Network function an infrastructure function that can affect the functional architecture in CDN but is outside the scope of this Recommendation. + +## 8.2 The functional framework for multimedia CDN + +Figure 8-1 shows the functional framework for multimedia CDN. + +![Functional framework for multimedia CDN diagram](7e670a2b556b53ea9002dfff3a420e08_img.jpg) + +The diagram illustrates the functional framework for a multimedia CDN, organized into three main vertical columns and a shared base. + +- Management functions (Left Column):** A vertical stack of five boxes: "Content management", "Access/ingestion management", "Network management", "Distribution policy management", and "Routing/redirection policy management". +- Content distribution and control functions (Middle Column):** A large box containing two sub-sections. The top sub-section has four boxes: "Content ingestion", "Storage/cache", "Content distribution", and "Content location", with a "Content pre-processing" box below them. The bottom sub-section is labeled "Content delivery functions" and contains "Content service" (with "Service-oriented functions entities" inside), and "Interconnection". +- Content routing/redirection functions (Right Column):** A vertical stack of two boxes: "GSLB" and "Service load balance (SLB)". +- Base:** Below the columns is a dashed box labeled "Network functions". At the very bottom are two boxes: "Functions in common" and "Service-oriented functions". + +F.743.5(18)\_F8-1 + +Functional framework for multimedia CDN diagram + +**Figure 8-1 – Functional framework of multimedia CDN** + +In essence, the functional framework for multimedia CDN consists of functions in common, and service-oriented functions. The functions in common include the basic functions that all types of CDN services are required to implement, e.g., content distribution, ingestion, storage, etc. The service-oriented functions include the specific functions that implement the service logic specifically for the target service. For example, as a service provided by CDN, the media transcoding function may not be required for web service, but may be required for IPTV service to provide various qualities of media streams. + +The functions in the framework are described in the following clauses. + +### 8.2.1 Management functions + +Several specific functions blocks are involved in this function. The blocks are specified as content management, network management, access/ingestion management, distribution policy management, and routing/redirection policy management. The major role of this function is to manage the content, policy and node server to guarantee that the CDN is running in a highly efficient and secure environment. + +### **8.2.2 Content distribution and control functions** + +Several specific functional blocks are involved in this function such as user request routing/redirection, content location, content distribution/delivery routing, content distribution and storage/cache. The major role of this function is to control the content distribution in the network with quick response, high efficiency and security. + +### **8.2.3 Content delivery functions** + +Several specific functional blocks are involved in this function such as load balance, interconnection and content service (including, but not limited to, web and streaming media service). The major role of this function is to deliver the related content to the end-user based on the user's request, the adapted transport protocols and the server nodes' status. The functions can be designed for different architectures according to the service which a service provider wants to provide. + +### **8.2.4 Content routing/redirecting functions** + +The content routing/redirecting functions are responsible for selecting the request content resource for users. The content resource may be the content location uniform resource locator (URL) or the media server address. If there is not any content hinted, the original content source location should be provided. Typically, a load balance system is designed to optimize the content selection. The load balance algorithm may have many priorities, such as current server load status, service type, input/output (I/O) states, etc. It is worth noting that the service load balance (SLB) can be optionally implemented inside a CDN node as a service-oriented function. + +### **8.2.5 Network functions** + +The network functions provides the network resource for data transmission and processing for the above-mentioned functions, which are the infrastructure functions in the CDN framework. Network functions can be changed because of technology evolution. The functional framework for the CDN may be affected. For example, the network resource reservation and allocation may be different when CDN is running on a SDN-based network instead of a conventional network, thereby affecting the functions in CDN. + +# **9 High-level interfaces** + +Figure 8-1 presents the framework for a multimedia CDN. Figure 9-1 provides the possible high-level interfaces based on Figure 8-1, through the consideration of the content source stratum, service stratum, network stratum and end-user stratum. The current CDN equipment used in IPTV service, as the implementation of content delivery functions, can be referenced from [b-ITU-T Y.1910]. + +![Figure 9-1: High-level interfaces between functions in multimedia CDN. The diagram shows a layered architecture. At the top are 'Service functions' and 'Content provider functions'. Below them is a dashed box labeled 'CDN service scope' containing 'Management functions', 'Content distribution and control functions', 'Content delivery functions', and 'Content routing/redirection functions'. Below the CDN scope are 'Network functions' and 'End-user functions'. Interfaces are labeled: A (Service functions to Management functions), B (Content provider functions to Content distribution and control functions), E (Content provider functions to Content routing/redirection functions), a1 (Management functions to Content distribution and control functions), a2 (Management functions to Content delivery functions), c1 (Content distribution and control functions to Content routing/redirection functions), b (Content distribution and control functions to Content delivery functions), c2 (Content delivery functions to Content routing/redirection functions), F (Management functions to Network functions), C (Content delivery functions to End-user functions), and D (Content routing/redirection functions to End-user functions).](af7916c89a458fdab6c3f443217388ae_img.jpg) + +Figure 9-1: High-level interfaces between functions in multimedia CDN. The diagram shows a layered architecture. At the top are 'Service functions' and 'Content provider functions'. Below them is a dashed box labeled 'CDN service scope' containing 'Management functions', 'Content distribution and control functions', 'Content delivery functions', and 'Content routing/redirection functions'. Below the CDN scope are 'Network functions' and 'End-user functions'. Interfaces are labeled: A (Service functions to Management functions), B (Content provider functions to Content distribution and control functions), E (Content provider functions to Content routing/redirection functions), a1 (Management functions to Content distribution and control functions), a2 (Management functions to Content delivery functions), c1 (Content distribution and control functions to Content routing/redirection functions), b (Content distribution and control functions to Content delivery functions), c2 (Content delivery functions to Content routing/redirection functions), F (Management functions to Network functions), C (Content delivery functions to End-user functions), and D (Content routing/redirection functions to End-user functions). + +F.743.5(18)\_F9-1 + +**Figure 9-1 – High-level interfaces between functions in multimedia CDN** + +From Figure 9-1, all interfaces can be categorized into two types: + +- 1) Interface between CDN service scope and other service scope. +- 2) An inner interface between CDN Functions + +The high-level interfaces shown in Figure 9-1 are not the logical reference points of the CDN functional architecture. The reference points should be defined in other future ITU-T Recommendations. + +The above interfaces are meant to realize the functions described in clause 9.1. + +## 9.1 Interfaces between CDN service scope and other service scope + +- **Interface A:** between management functions and service functions. It is used to receive the service request from service providers and to manage the CDN nodes and service according to those requests. +- **Interface B:** between content distribution and control functions and content provider functions. It is used to ingest content from the content source. +- **Interface C:** between content delivery functions and end-user functions. It is used to deliver the content to end users and to manage the media and control connection session. +- **Interface D:** between content routing/redirection functions and end-user functions. It is used to receive the content request from an end user and return the content URL or redirect the end user to the right media server after loading balance. +- **Interface E:** between content routing/redirection functions and content provider functions. It is used to translate the original content address to a new URL that can be mapped to the CDN address. +- **Interface F:** between management functions and network functions. It is used to detect the network status and to modify its network control policy. + +## 9.2 Inner interfaces between CDN functions + +- **Interface a1:** between management functions and content distribution and control functions. It is used to exchange the management request, such as content process policy, content distribution policy, etc., between those two functions. This interface is mainly used for CDN central node. +- **Interface a2:** between management functions and content delivery functions. It is used to exchange the management request, such as node configuration, content delivery policy, etc., between those two functions. This interface is mainly used for CDN edge node. +- **Interface b:** between content distribution and control functions and content delivery functions. It is used to implement the distribution, content track and other distribution functions. +- **Interface c1:** between content routing/redirecting functions and content distribution and control functions. It is used to collect the entire CDN servers' status and to implement global load balance. +- **Interface c2:** between content routing/redirecting functions and content delivery functions. It is used to locate the right content URL or redirect user request to a CDN edge node. In addition, it can implement inner node loading balance. + +# Bibliography + +- [b-ITU-T H.780] Recommendation ITU-T H.780, *Digital signage: Service requirements and IPTV-based architecture.* +- [b-ITU-T X.609] Recommendation ITU-T X.609, *Managed peer-to-peer (P2P) communications: Functional architecture.* +- [b-ITU-T X.1162] Recommendation ITU-T X.1162, *Security architecture and operations for peer-to-peer networks.* +- [b-ITU-T Y.1910] Recommendation ITU-T Y.1910 (2008), *IPTV functional architecture.* +- [b-ITU-T Y.2084] Recommendation ITU-T Y.2084, *Distributed service networking content distribution functions.* + + + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.743.6-201808-I_PDF-E/053f1077d592e6622cd21dc4bb4cb366_img.jpg b/marked/F/T-REC-F.743.6-201808-I_PDF-E/053f1077d592e6622cd21dc4bb4cb366_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..fba78bcc41ea2c83508866d506252b3103467d3a --- /dev/null +++ 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+**ITU-T F.744.5 (09/2023)** + +SERIES F: Non-telephone telecommunication services + +Multimedia services + +--- + +**Requirements for content delivery networks +based on peer-to-peer technology** + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +# ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.744.5 + +# Requirements for content delivery networks based on peer-to-peer technology + +## Summary + +Recommendation ITU-T F.744.5 describes the requirements for a peer-to-peer content delivery network (P2P CDN). It specifies the overall functional architecture, domains and functional role relationships, functional blocks and their mutual relationships, service provision requirements, availability requirements, scalability requirements and security considerations. P2P CDN provides a scalable and elastic CDN function pool of shareable terminal device computing resources, storage resources and uplink bandwidth to save loads of the current CDN and improve user experience. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.744.5 | 2023-09-13 | 16 | 11.1002/1000/15619 | + +## Keywords + +Content delivery network (CDN), P2P, streaming service. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2023 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-----------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Overview ..... | 2 | +| 7 Objectives ..... | 3 | +| 8 Requirements ..... | 4 | +| 8.1 General requirements..... | 4 | +| 8.2 Service provision requirements ..... | 6 | +| 8.3 Availability requirements ..... | 6 | +| 8.4 Scalability requirements ..... | 7 | +| 8.5 Service management requirements..... | 8 | +| 9 Security requirements ..... | 8 | +| 9.1 Content copyright protection requirements ..... | 8 | +| 9.2 Terminal security protection requirements..... | 8 | +| 9.3 Content tamper-proof requirements ..... | 8 | +| Appendix I – Scenarios for P2P CDN ..... | 10 | +| I.1 P2P CDN video-on-demand service..... | 10 | +| I.2 P2P CDN live-streaming service..... | 11 | +| Bibliography..... | 12 | + + + +# Recommendation ITU-T F.744.5 + +## Requirements for content delivery networks based on peer-to-peer technology + +# 1 Scope + +This Recommendation specifies the general functional requirements for a content delivery network based on peer-to-peer technology (P2P CDN). + +This Recommendation encompasses the following key aspects: + +- General functional framework; +- Interaction between function blocks; +- Service provision and management requirements; +- Availability, scalability and security requirements; +- Scenarios for P2P CDN service (provided in Appendix I). + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 content delivery network** [b-ITU-T Y.2084]: A content delivery network (CDN) is a system of distributed servers that deliver content (e.g., web pages, files, videos and audios) to users based on pre-defined criteria such as the geographic locations of users, the status of the content delivery server and the IP network connection. + +**3.1.2 static content** [b-ITU-T F.744.2]: Contents that changes infrequently. This type of content is not changed with the requests of users. + +**3.1.3 peer-to-peer content delivery network (P2P CDN)** [b-ITU-T Y.2084]: The content delivery network (CDN) in which content is delivered in the mode of P2P; the delivery may be from CDN server to users or from CDN servers to CDN servers. + +NOTE – Delivering in the mode of P2P means that the content is sliced into chunks, and the copies of the chunks are stored in multiple CDN servers. Users or CDN servers can download chunks of the content from multiple CDN servers. + +### 3.2 Terms defined in this Recommendation + +None. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|---------|---------------------------------------| +| AR | Augmented Reality | +| CDN | Content Delivery Network | +| CMS | Content Management System | +| FTP | File Transfer Protocol | +| HD | High Definition | +| IDC | Internet Data Centre | +| IP | Internet Protocol | +| IPTV | Internet Protocol Television | +| LAN | Local Area Network | +| MAN | Metropolitan Area Network | +| P2P CDN | Peer-to-Peer Content Delivery Network | +| RTMP | Real-Time Messaging Protocol | +| RTSP | Real-Time Streaming Protocol | +| SD | Standard Definition | +| SDK | Software Development Kit | +| STB | Set-Top-Box | +| VoD | Video on Demand | +| VR | Virtual Reality | + +## 5 Conventions + +In this Recommendation: + +- The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. +- The keywords "is recommended" indicate a requirement which is recommended but which is not required. Thus, this requirement need not to be present to claim conformance. + +## 6 Overview + +P2P CDN, as a specific CDN model providing content delivery services, solves the problem of the network traffic growth brought by multimedia content. Along with the rapid advance of computer-related technologies, how to efficiently provide multimedia content for a large number of heterogeneous users on the Internet, especially videos, has become a noticeable issue. + +A peer to peer (P2P) approach, where peers collaborate with one another to reduce server loading, provides a feasible solution for the scalability issue. It has recently become a popular alternative to CDN to cope with the growing demand of end users. In P2P scheme, a peer acts not only as a client to receive services but also as a server to forward services to other peers. Using peer-to-peer (P2P) technology, the traditional CDN will be able to provide superior service and reduce construction and maintenance costs. Figure 1 illustrates the basic concept of P2P CDN. + +Furthermore, intelligent terminal devices such as smart set-top-boxes (STBs), smartphones and smart home-gateways, can install various kinds of application plugin or software to deploy new service + +functions. The computing and storage capability of these terminal devices are enhanced dramatically, and a large number of idle computing and storage resources can be utilized. Therefore, P2P CDN is more likely to be implemented. + +![Diagram illustrating the basic concept of P2P CDN. A central cloud icon represents the network. Above it, a 'Content source' (represented by a monitor with play buttons) is connected. To the left, a 'CDN' (represented by server icons) is connected. To the right, a 'Back-end system' (represented by server icons) is connected. Below the cloud, five terminal devices (PC, Tablet, STB, HGW, and Smart phone) are connected to the cloud. These devices are grouped by a dashed oval labeled 'P2P CDN'. The devices are also connected to a 'Front-end system' (represented by a smartphone icon). The diagram shows content flowing from the Content source through the cloud to the terminal devices, which then share content among themselves via the P2P CDN.](acfc53eca625d62b38aa2563efa95c3e_img.jpg) + +Diagram illustrating the basic concept of P2P CDN. A central cloud icon represents the network. Above it, a 'Content source' (represented by a monitor with play buttons) is connected. To the left, a 'CDN' (represented by server icons) is connected. To the right, a 'Back-end system' (represented by server icons) is connected. Below the cloud, five terminal devices (PC, Tablet, STB, HGW, and Smart phone) are connected to the cloud. These devices are grouped by a dashed oval labeled 'P2P CDN'. The devices are also connected to a 'Front-end system' (represented by a smartphone icon). The diagram shows content flowing from the Content source through the cloud to the terminal devices, which then share content among themselves via the P2P CDN. + +F.744.5(23) + +**Figure 1 – Basic concept of P2P CDN** + +## 7 Objectives + +P2P CDN is a paradigm using peer-to-peer technology for content delivery for various multimedia services. P2P CDN provides a scalable and elastic CDN function pool of shareable terminal devices computing resources, storage resources and uplink bandwidth to save the loads of current CDN and improve user experience. + +The following are the advantages of applying P2P CDN: + +- Reducing the cost of CDN. The main cost of the current CDN provider is to purchase servers, bandwidth and to rent IDC. P2P CDN utilizes some idle resources of terminal devices and uplink bandwidth, which the end users have already invested in. It greatly reduces the cost of CDN. +- Improving user experience. Because the nodes of P2P CDN are located in terminal devices, users may receive content from their own terminal devices, instead of from CDN nodes deployed in the network. Alternatively, other users may receive content from fellow users' terminal devices which are located in the same local area network (LAN) or metropolitan area network (MAN), instead of receiving it from the CDN nodes deployed in the backbone network which is far away from the user-end. Receiving contents from terminal devices close to the users may bring ultra-low-latency, high throughput, multi-direction traffic and provide the experience of lossless content delivery. When content is hotter, i.e. requested by more users, the user experience will be improved when P2P CDN technology is applied. + +The widespread use of P2P CDN may bring new business models and new business ecology. + +- Ultra-high-definition video service is now widespread. One of the main causes holding back ultra-high-definition video from being widespread in earlier years was the cost of CDN and + +the quality of delivery for the current CDN. With the cheap cost and high quality of delivery of P2P CDN, ultra-high-definition video services may be developed and may be widespread in the future. + +- Bringing new profit for telecom operators. Users usually only use the downlink bandwidth of broadband, and the uplink bandwidth has not been used until now. P2P CDN can be used to create a new business model and bring new profit using the uplink bandwidth. Telecom operators can sell the P2P CDN services to vendors and return some profit to users who provide terminal devices and uplink bandwidth of P2P CDN. + +# 8 Requirements + +### 8.1 General requirements + +#### 8.1.1 Functional framework requirements + +FR-01: The P2P-CDN system is required to consist of two parts, which are the front-end system and the back-end system. + +FR-02: The front-end system is recommended to consist of millions of intelligent terminal devices installing the P2P software application. + +FR-03: The front-end system is recommended to include two functions. One is providing the delivery function which is sharing the content of their own system, while at the same time delivering the content to other peers. The other is utilizing the contents which are shared by peers. + +FR-04: The back-end system is recommended to include the following functional blocks: system management functions, service control functions, resource control functions and resource delivery functions. + +The general function blocks of P2P CDN are illustrated in Figure 2. + +![Figure 2 – General functional framework of P2P CDN. The diagram shows the interaction between various function blocks across two peers, Peer A and Peer B. On the left, a dashed box labeled 'Functions in common' contains 'CDN network function' and 'Content management function'. Peer A's 'Front-end system' (yellow) contains 'Service function' and 'User function'. Peer A's 'Back-end system' (blue) contains 'Resource delivery function', 'Resource control function', 'Service control function', and 'System management function'. Peer B's 'Front-end system' (yellow) contains 'User function' and 'Service function'. Arrows labeled a-j show interactions: 'a' from Content management to Resource control; 'b' from Resource control to Resource delivery; 'c' from System management to Resource control and Service control; 'd' from User function to Service function; 'e' from Service function to Resource delivery; 'f' from User function to Service control; 'g' from System management to Service control; 'h' from Service control to User function; 'i' from Service control to Peer B's Service function; 'j' from System management to Peer B's Service function; 'k' from Peer A's Service function to CDN network function. A red dashed box labeled 'P2P Service-oriented functions' encloses the front-end and back-end systems of both peers.](b0211cee4b20034939d883ac0d70f696_img.jpg) + +Figure 2 – General functional framework of P2P CDN. The diagram shows the interaction between various function blocks across two peers, Peer A and Peer B. On the left, a dashed box labeled 'Functions in common' contains 'CDN network function' and 'Content management function'. Peer A's 'Front-end system' (yellow) contains 'Service function' and 'User function'. Peer A's 'Back-end system' (blue) contains 'Resource delivery function', 'Resource control function', 'Service control function', and 'System management function'. Peer B's 'Front-end system' (yellow) contains 'User function' and 'Service function'. Arrows labeled a-j show interactions: 'a' from Content management to Resource control; 'b' from Resource control to Resource delivery; 'c' from System management to Resource control and Service control; 'd' from User function to Service function; 'e' from Service function to Resource delivery; 'f' from User function to Service control; 'g' from System management to Service control; 'h' from Service control to User function; 'i' from Service control to Peer B's Service function; 'j' from System management to Peer B's Service function; 'k' from Peer A's Service function to CDN network function. A red dashed box labeled 'P2P Service-oriented functions' encloses the front-end and back-end systems of both peers. + +Figure 2 – General functional framework of P2P CDN + +In the functional framework of P2P CDN, each peer serves as both a server and a user, providing services to other nodes, while also enjoying the services provided by other nodes. Figure 2 shows the interaction between each function block when "Peer A" requests content resources from a peer. The following steps describe the interaction between the function blocks: + +- a) The content resource is injected from the content management system (CMS) into the CDN. +- b) The deployment of resources from back-end systems to front-end systems. +- c) The synchronization of resource deployment information to the service control function and the resource control function. +- d) Peer A's media player triggers the service function. +- e) The back-end system pre-deploys resources to the service module of the front-end system, and the front-end system provides feedback on the resource list to the back-end system. +- f) The user module of the front-end system requests CDN content resources from the back-end system. +- g) The back-end system's service control module returns scheduling information and selects multiple nodes (P2P CDN nodes) to provide services to the front-end system based on access requirements and resource lists. +- h) The service control module feedbacks the node list to the front-end system. +- i) The Peer A user requests content resources from multiple nodes including Peer B. +- j) Peer B provides Peer A with the requested content resources. +- k) If the resources accessed by Peer A do not exist in Peer B, they are required to be obtained through the CDN network. + +#### 8.1.2 Requirement for the system management function + +SMF-01: The system management block of P2P CDN is required to manage each P2P CDN peer, including terminal equipment, data monitoring and system operation. Its management function includes: + +- Peer nodes management; +- Content management; +- Resource monitoring; +- Operation and maintenance management; +- Statistical analysis. + +#### 8.1.3 Requirements for service control functions + +SCF-01: Service control functions are responsible for the overall P2P CDN business request and scheduling. The processing of the P2P CDN content distribution service is based on the user's usage requirements. If the access resources are not available, then the controller will trace to the existing CDN network to obtain the source. + +SCF-02: The service function block of P2P CDN is required to respond to the content service of peer nodes. It is required to deploy the docking resource, realizing the downloading of the resource content from the resource deployment block. In the meantime, the service function should provide capabilities, which can interact with the background management system, and realize resource information reporting of peer nodes. + +#### 8.1.4 Requirements for the resource delivery function + +RDF-01: P2P CDN is required to support the content distribution processing function. The deployment resources can be pushed and pulled according to the requirements. The resource predeployment pre-deploys the content resources to the P2P service block. After the P2P block is deployed successfully, the resources are pre-deployed. And the resource predeployment and scheduling control blocks are synchronized. + +#### **8.1.5 Requirements for the resource control function** + +RCF-01: The resource control function is in charge of the resource scheduling of peer nodes. The scheduling server chooses multiple peer points (P2P CDN nodes) to provide services according to the return scheduling of the resource list and dispatches CDN services. The process contains basic resource parameters: the number of P2P CDN nodes, storage space, user concurrency and network traffic. + +## **8.2 Service provision requirements** + +#### **8.2.1 Video service** + +VS-01: P2P CDN is required to have the capabilities of supporting the content distribution for a variety of video services through various kinds of terminal devices, including IPTV-based live broadcast, AR, VR and on-demand video service. + +VS-02: P2P CDN is recommended to support ultra-high definition HD (such as 8K, 4K), HD, SD and multiple streams of IPTV, PC, mobile device video services. + +#### **8.2.2 Storage service** + +P2P CDN is required to have the capabilities of storing/cacheing static contents within their service coverage area. + +#### **8.2.3 Accelerating service.** + +P2P CDN is recommended to support the file acceleration download service and the web acceleration service. + +#### **8.2.4 Data transmission service** + +P2P CDN is recommended to have the capabilities of supporting multiple protocols including HTTPs, HTTP1.0, HTTP2.0, RTSP, RTMP and FTP. + +### **8.3 Availability requirements** + +#### **8.3.1 Requirements for network access availability** + +NSA-01: P2P CDN is required to preserve the architecture and functions of the original CDN system while introducing the P2P technology to distribute and transmit the media streaming by controlling and managing the edge nodes. + +NSA-02: According to this backbone aggregation and edge distributed architecture, the P2P CDN is recommended to be divided into several areas, which are called P2P autonomous domains. The data exchange from users is limited to the domain in which they are located, and the inter-domain exchange is avoided as much as possible. + +NSA-03: The P2P CDN is recommended to be divided into several autonomous regions according to the following principles: + +- The autonomous domains are required to be divided according to the geographical area where the CDN edge node is located. +- The IP addresses range of the users in the same domain is required to be the same as the range of the user IP address pool served by the CDN nodes. +- The hotspot area is to be combined properly with the unpopular area and the network bandwidth of the unpopular area used to alleviate the network pressure in the hotspot area and improve the overall concurrency and network utilization efficiency. +- The P2P autonomous domains are required to be divided according to the actual characteristics of the system network. + +- The logical P2P autonomous domain is added to enhance the capacity of the overload P2P autonomous domain which serves a backup function. + +#### **8.3.2 Requirements for service performance** + +SP-01: P2P CDN is required to achieve the function of on-demand streaming, live broadcasting and file downloading services. The requirements for service performance can be defined as: service success rate, service responding time, network packet loss rate and the jitter of streaming. + +#### **8.3.3 Requirements for device performance** + +DP-01: All devices accessing the P2P CDN are recommended to be able to transform the service quality by the following indicators: concurrency, network bandwidth, storage capacity, number of nodes and regional coverage. + +DP-02: All devices accessing the P2P CDN are recommended to support cloud deployment, using a common x86 server, and to support hardware and software separation. + +DP-03: All devices accessing the P2P CDN are recommended to satisfy the ability to serve multiple network protocols. + +### **8.4 Scalability requirements** + +#### **8.4.1 Requirements for system scalability** + +SS-01: The P2P CDN system is required to maintain high scalability so that when a large number of requests suddenly arrive at the media server, the system can still serve each request within a reasonable delay without breakdown. + +SS-02: The P2P CDN system is required to be designed in modules. By modifying the interfaces between modules, a P2P CDN is more scalable for service expansion. + +#### **8.4.2 Requirements for central node scalability** + +CNS-01: The P2P CDN is required to break the limitation of a centralized architecture of a CDN, which is related to the number of data centres coupled with the available exit/transit bandwidth from these data centres. + +CNS-02: The P2P CDN is required to add a P2P management centre to provide centralized management functions for the entire system, enabling the unified management and monitoring of all CDN edge nodes. + +#### **8.4.3 Requirements for edge node scalability** + +The P2P CDN is recommended to access various kinds of devices that can provide the front-end system function defined in clause 8.1. The edge nodes of a P2P CDN are required to be able to embed the P2P CDN software development kit (SDK), supporting the registration function, information uploading function, service distribution function and load testing function. + +#### **8.4.4 Requirement for the expansion of a new service** + +The P2P CDN is required to be updatable, including the hardware, software and P2P plugin, supporting future emerging video services such as adaptive streaming media services. + +#### **8.4.5 Requirement for redundancy** + +The P2P CDN is required to provide redundancy and to have a certain fault tolerance mechanism when providing services to the terminal through the network. + +- The P2P CDN is required to support service redundancy between peers. If the node that the user in the region of cannot provide services for some reason, such as the node performance having reached the limit value, the node being broken down or the node having no content. + +- The P2P CDN is required to provide link redundancy, either the dual-link redundancy of control and media or the external service dual link. +- The P2P CDN is required to provide storage redundancy, guaranteeing the high availability of peer node storage. + +### **8.5 Service management requirements** + +#### **8.5.1 Requirements for network analysis** + +NA-01: The P2P CDN is required to have the capability of statistically analysing the services provided by the content providers. + +NA-02: The P2P CDN is required to have the capability of analysing the carrier networks' performance data detected and provide the statistical performance reports about the carrier networks. + +#### **8.5.2 Requirements for resource management** + +RM-01: The P2P CDN is required to have the capacity of the data storage/cacheing, and the capacity of providing their data storage/cacheing spaces to the consumers. + +RM-02: The P2P CDN is required to build related functions or capabilities of the original resources needed while providing services that needs the tracing of the original resources, based on the related cooperation protocols between the P2P CDN providers and the content providers. + +RM-03: The P2P CDN is required to have the capabilities of redirecting the content consumer requests to the peer nodes near the request content consumers. + +## **9 Security requirements** + +### **9.1 Content copyright protection requirements** + +CCPR-01: The P2P CDN is required to protect the content copyright when the P2P data flow is initiated between terminals based on the scheduling service system. Since scheduling service instructions and file blocks between peer nodes are transmitted through proprietary protocols, it can also effectively achieve copyright protection of content. + +CCPR-02: The P2P CDN is required to protect the cache content after accessing P2P services even if the terminal is compromised, so attackers cannot directly find the specific path for storing content. + +### **9.2 Terminal security protection requirements** + +TSPR-01: The P2P CDN is recommended to guard against peers that may attempt to inject or distribute malicious content within the network. Measures such as reputation systems, trust mechanisms and content validation can help identify and isolate malicious peers or unauthorized content. + +TSPR-02: The P2P CDN is recommended to employ security measures to prevent unauthorized peers from joining the network. Authentication protocols and encryption can be utilized to ensure that only trusted peers can participate in the P2P network. + +### **9.3 Content tamper-proof requirements** + +CTPR-01: The P2P CDN is required to validate the data during content localization in P2P peer nodes; data is discarded when validation fails. Therefore, as long as the hash digest value of the original resource is consistent, it can ensure that the transmitted content resource is theoretically tamper-free. + +CTPR-02: Since content is distributed across multiple peers, ensuring the authenticity and integrity of the content becomes crucial. The P2P CDN is recommended to employ measures such as content signing, digital signatures and hash verification to verify the integrity of chunks and prevent unauthorized modifications or tampering. + +# Appendix I + +## Scenarios for P2P CDN + +(This appendix does not form an integral part of this Recommendation) + +## I.1 P2P CDN video-on-demand service + +Nowadays, P2P CDN technology has been widely used in video-on-demand (VoD) services and has been developed rapidly, breaking the limitation of traditional CDN, effectively improving resource utilization and realizing the construction of a system platform with high service quality at lower infrastructure costs. + +The implementation of P2P CDN technology in the VoD system, compared with traditional VoD systems based on traditional client/server architecture, has several advantages. Firstly, it enhances system stability by leveraging the scalability of content providers and reducing payload during backbone network traffic congestion. Secondly, instead of relying solely on centralized servers, the content is distributed across multiple peers. If a particular server or node becomes unavailable, the content can still be accessed. Thirdly, it ensures the user's quality of service by utilizing a multi-path downloading program that retrieves clips from peer nodes, effectively preventing server response slowness or service termination caused by the increasing number of nodes in traditional CDNs. + +Figure I.1 illustrates the workflow of P2P CDN implementation in the VoD service. + +![Sequence diagram illustrating the workflow for P2P CDN VoD service. The diagram shows interactions between Media player, P2P front-end module, CDN node, P2P back-end module, and PEER. The process involves URL requests, feedback loops, caching, and P2P resource utilization.](cb4cfa42ce34febde7bdb882f3fc3094_img.jpg) + +``` +sequenceDiagram + participant Media player + participant P2P front-end module + participant CDN node + participant P2P back-end module + participant PEER + + Note right of Media player: 1. User A requests a URL address + Media player->>P2P front-end module: + Note right of P2P front-end module: 2. Requests a URL address from CDN node + P2P front-end module->>CDN node: + Note right of CDN node: 2. Record user A and provide feedback to the P2P server + CDN node-->>P2P back-end module: + Note right of P2P back-end module: 3. Record User A and make it a peer node if available + P2P back-end module->>PEER: + Note right of P2P front-end module: 3. CDN node feedbacks the optimal node information + P2P front-end module-->>Media player: + Note right of Media player: 4. Start playing and pre-download cache + Media player->>P2P front-end module: + Note right of Media player: 5. User B requests the same URL address + P2P front-end module->>CDN node: + Note right of P2P front-end module: 6. Requests a URL address from CDN node + Note right of CDN node: 6. Record user B and provide feedback to the P2P server + CDN node-->>P2P back-end module: + Note right of P2P front-end module: 7. CDN node feedbacks the optimal node information + P2P front-end module-->>Media player: + Note right of Media player: 8. Start playing and pre-download cache + Note right of P2P front-end module: 9. P2P service function determines that when the cached data reaches the safe reading threshold, it requests PEER node information from the P2P server + P2P front-end module-->>P2P back-end module: + Note right of P2P back-end module: 10. Feedbacks with User A's information + P2P back-end module-->>P2P front-end module: + Note right of P2P front-end module: 11. User B initiates access request from User A + P2P front-end module-->>PEER: + Note right of P2P front-end module: 12. User A uses idle upstream bandwidth to upload resources + P2P front-end module-->>PEER: + Note right of Media player: 13. Utilize P2P resources to continue caching data, switch back to using CDN to download resources if viewing cache is lower than threshold + Media player->>P2P front-end module: +``` + +Sequence diagram illustrating the workflow for P2P CDN VoD service. The diagram shows interactions between Media player, P2P front-end module, CDN node, P2P back-end module, and PEER. The process involves URL requests, feedback loops, caching, and P2P resource utilization. + +F.744.5(23) + +Figure I.1 – Workflow for P2P CDN VoD service + +## I.2 P2P CDN live-streaming service + +Live streaming has the potential to generate huge amounts of traffic as its popularity with users' increases. Most content providers have opted for direct distribution using content delivery networks (CDN) even though low-cost delivery can be achieved using peer-to-peer (P2P) architecture. + +The implementation of P2P CDN technology in live-streaming services has several advantages. P2P CDN leverages the distributed nature of peers to improve redundancy and reliability. If one peer goes offline or experiences connectivity issues, other peers can compensate by serving the content. Since the video content is distributed across multiple peers, viewers can retrieve chunks from nearby sources rather than relying solely on a central server. This localized content delivery can decrease the distance data has to travel, resulting in lower latency and faster video playback. + +Figure I.2 illustrates the workflow of P2P CDN implementation in the live-streaming service. + +![Sequence diagram illustrating the workflow for P2P CDN live-streaming service. The diagram shows interactions between an STB, P2P front-end modules, a P2P back-end module, and a CDN node streaming source.](df82d77a0d2637cbf2da9ea920a554fa_img.jpg) + +``` +sequenceDiagram + participant STB + participant P2P_FE1 as P2P front-end module + participant P2P_BE as P2P back-end module + participant P2P_FE2 as P2P front-end module + participant CDN as CDN node streaming source + + Note right of STB: 1. User A requests the streaming media from origin server + STB->>P2P_FE1: 2. Returns the redirect URL + Note right of P2P_FE1: 3. Initiate playback request + P2P_FE1->>P2P_BE: 4. Synchronize the streaming resource information stored on the other peers + P2P_BE->>P2P_FE2: 5. Request streaming media from other peers + P2P_FE2->>P2P_BE: 6. Receive streaming media from other peers + Note right of P2P_BE: 7. STB receive streaming + Note right of P2P_FE2: 5. Request the streaming media from streaming source if no appropriate peers are served + P2P_FE2->>CDN: 6. Receive streaming media from source + Note right of CDN: 7. STB receive streaming +``` + +The diagram illustrates the workflow for P2P CDN live-streaming service. It involves the following components and steps: + +- STB**: The client device that requests and receives the streaming media. +- P2P front-end module**: Two instances of this module handle client requests and coordinate with the back-end. +- P2P back-end module**: Handles resource synchronization and requests between front-end modules. +- CDN node streaming source**: The origin server that provides the streaming media when no peers are available. + +The sequence of interactions is as follows: + +- User A requests the streaming media from the origin server (STB to P2P front-end module). +- The P2P front-end module returns the redirect URL (P2P front-end module to STB). +- The STB initiates a playback request (STB to P2P front-end module). +- The P2P front-end module synchronizes the streaming resource information stored on the other peers (P2P front-end module to P2P back-end module). +- The P2P back-end module requests streaming media from other peers (P2P back-end module to P2P front-end module). +- The P2P front-end module receives streaming media from other peers (P2P front-end module to P2P back-end module). +- The STB receives the streaming media (P2P back-end module to STB). +- If no appropriate peers are served, the P2P front-end module requests the streaming media from the streaming source (P2P front-end module to CDN node streaming source). +- The P2P front-end module receives the streaming media from the source (CDN node streaming source to P2P front-end module). +- The STB receives the streaming media (P2P front-end module to STB). + +Sequence diagram illustrating the workflow for P2P CDN live-streaming service. The diagram shows interactions between an STB, P2P front-end modules, a P2P back-end module, and a CDN node streaming source. + +Figure I.2 – Workflow for P2P CDN live-streaming service + +# Bibliography + +- [b-ITU-T F.744.2] Recommendation ITU-T F.744.2 (2018), *Framework and interfaces for multimedia content delivery network*. +- [b-ITU-T Y.2084] Recommendation ITU-T Y.2084 (2015), *Distributed service networking content distribution functions*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.745-201607-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/F/T-REC-F.745-201607-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..22dc7ff0fb30f976cc1e576c45d2b7e65fa5ddc7 --- /dev/null +++ b/marked/F/T-REC-F.745-201607-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:aa14933e776f7d0be8b2d60b81cbb6c1ee49deb5080e0281da05296f48189055 +size 6859 diff --git a/marked/F/T-REC-F.745-201607-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg b/marked/F/T-REC-F.745-201607-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1ec801e8348edcab3c2fbab35d1dd22c6d319bc4 --- /dev/null +++ b/marked/F/T-REC-F.745-201607-I_PDF-E/8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:95f5e36f07578827052833fda72f9faa31a1655d9094e871757be3d0b5b81cef +size 102920 diff --git a/marked/F/T-REC-F.745-201607-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg b/marked/F/T-REC-F.745-201607-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..9bd2d556d7a72d27cb1ac643c1302d6187b6f9a9 --- /dev/null +++ b/marked/F/T-REC-F.745-201607-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:a111316808888a3575e3354cd07cf3372a82670ff13d316e191ce8bdb09f1e5c +size 140629 diff --git a/marked/F/T-REC-F.745-201607-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/F/T-REC-F.745-201607-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..f1a94b979ad3ac7a1c470a4e605c844aea0afbc9 --- /dev/null +++ b/marked/F/T-REC-F.745-201607-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:4808916be97f6069726495b13d2f2401329b4adb2a9590b7ff86cd4b88a0c265 +size 62923 diff --git a/marked/F/T-REC-F.745-201607-I_PDF-E/raw.md b/marked/F/T-REC-F.745-201607-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..2314b9b5f3c67d3ace6dc918ec98a9153934f735 --- /dev/null +++ b/marked/F/T-REC-F.745-201607-I_PDF-E/raw.md @@ -0,0 +1,518 @@ + + +International Telecommunication Union + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**F.745** + +(07/2016) + +SERIES F: NON-TELEPHONE TELECOMMUNICATION +SERVICES + +Multimedia services + +--- + +**Functional requirements for network-based +speech-to-speech translation services** + +Recommendation ITU-T F.745 + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) features a globe with a red lightning bolt striking across it. To the right of the globe, the text "International Telecommunication Union" is written in a blue, sans-serif font, with "ITU" in a larger, bold font above it. + +ITU logo + +International +Telecommunication +Union + +# ITU-T F-SERIES RECOMMENDATIONS NON-TELEPHONE TELECOMMUNICATION SERVICES + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multdestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| MULTIMEDIA SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## Recommendation ITU-T F.745 + +# Functional requirements for network-based speech-to-speech translation services + +## Summary + +Recommendation ITU-T F.745 specifies a high level functional model, a service description and requirements for speech-to-speech translation (S2ST) accomplished by connecting distributed S2ST modules all over the world through a network. To extend this network-based S2ST to other modalities, such as sign language, the modality conversion markup language (MCML) needs to have an expandable structure. The scope of this Recommendation is limited to the application protocol and the services using the network-based S2ST. + +This revision includes additional information to clarify that Recommendation ITU-T F.745 could be applicable to both face-to-face communication and remote communication. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.745 | 2010-10-14 | 16 | 11.1002/1000/10982 | +| 2.0 | ITU-T F.745 | 2016-07-14 | 16 | 11.1002/1000/12897 | + +## Keywords + +Automatic speech recognition (ASR), machine translation (MT), modality conversion markup language (MCML), speech-to-speech translation (S2ST), text-to-speech synthesis (TTS). + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2016 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +###### Page + +| | | | +|-----|-----------------------------------------------------------------------------------------------------------------------------------------|----| +| 1 | Scope..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 2 | +| 3.1 | Terms defined elsewhere ..... | 2 | +| 3.2 | Terms defined in this Recommendation..... | 2 | +| 4 | Abbreviations and acronyms ..... | 3 | +| 5 | Conventions ..... | 3 | +| 6 | High-level functional model and generic service description ..... | 4 | +| 6.1 | System overview ..... | 4 | +| 6.2 | Functional model of modality conversion (MC) through communication between modality conversion protocol (MCP) clients and servers ..... | 4 | +| 6.3 | Service description ..... | 7 | +| 7 | Requirements ..... | 7 | +| 7.1 | User input requirements ..... | 7 | +| 7.2 | Network requirements ..... | 8 | +| 7.3 | User device requirements ..... | 8 | +| 7.4 | Modality conversion (MC) client requirements ..... | 8 | +| 7.5 | Modality conversion (MC) server requirements ..... | 8 | +| 7.6 | Quality requirements ..... | 9 | +| 7.7 | Security and privacy requirements ..... | 9 | +| 7.8 | Codec requirements ..... | 9 | +| | Appendix I – Service description in applications ..... | 10 | +| I.1 | Shared speech-to-speech translation (S2ST) client of two-party communication ..... | 10 | +| I.2 | Personal speech-to-speech translation (S2ST) client communication..... | 10 | +| I.3 | Cross-modality communication..... | 10 | +| | Bibliography..... | 12 | + +# Introduction + +The fact that the world has many different languages is one of the barriers to mutual understanding. The more directly people who speak different languages can communicate without language boundaries, the more mutual understanding can be accelerated and the closer human relationships can be constructed all over the world. To achieve such communication between humans, speech-to-speech translation (S2ST) technologies can be used. S2ST is a technology that recognizes the speech in one language, translates the recognized speech into another language, and then synthesizes the translation into speech. The leveraging of S2ST technologies in a pragmatic manner, which has long been one of mankind's dreams, may have a significant impact on tourism, social services, safety, and security by removing language barriers, and may ultimately influence language education. To construct S2ST systems, automatic speech recognition (ASR), machine translation (MT) and text-to-speech synthesis (TTS) must be built for source and target languages by collecting speech and language data, such as audio data, its manual transcriptions, pronunciation lexica for each word, parallel corpora for translation and so on. It is very difficult for individual organizations to build S2ST systems covering all topics and languages. However, by interconnecting ASR, MT and TTS modules developed by separate organizations and distributed globally through a network, one can create S2ST systems that break the world's language barriers. + +This Recommendation defines the service description and the requirements for network-based S2ST technologies consisting of various distributed modules connected together in a network. + +## Functional requirements for network-based speech-to-speech translation services + +# 1 Scope + +This Recommendation specifies the service description and the requirements for speech-to-speech translation (S2ST) accomplished by connecting distributed S2ST modules all over the world through a network. This service provides S2ST that recognizes the speech in one language, translates the recognized speech into another language, and then synthesizes the translation into speech. People who speak different languages can communicate using this service. + +The applications and services using network-based S2ST technologies are characterized by the following components: + +- S2ST client: + - user client for speech/text input and output. +- S2ST servers: + - speech recognition: speech is recognized and transcribed; + - machine translation: text in source language is translated into text in target language; + - speech synthesis: speech signal is created from text. +- Communication protocol: + - communication protocol to connect user clients and the above S2ST servers. + +In order to extend the network-based S2ST to other modalities (e.g., sign language), a communication protocol is incorporated for modality conversion (MC), which converts single/multiple modality information to different single/multiple modality information. The communication protocol for MC needs to have an expandable structure. + +- Modality conversion markup language (MCML): + - XML schema that serves as a data description for data exchanged among modality conversion modules. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T H.625] Recommendation ITU-T H.625 (2010), *Architecture for network-based speech-to-speech translation services*. +- [IETF RFC 2279] IETF RFC 2279 (1998), *UTF-8, a transformation format of ISO 10646*. +- [IETF RFC 2396] IETF RFC 2396 (1998), *Uniform Resource Identifiers (URI): Generic Syntax*. +- [IETF RFC 2616] IETF RFC 2616 (1999), *Hypertext Transfer Protocol – HTTP/1.1*. +- [IETF RFC 2818] IETF RFC 2818 (2000), *HTTP Over TLS*. + +| | | +|------------------|-----------------------------------------------------------------------------------------------------------------| +| [IETF RFC 3550] | IETF RFC 3550 STD 0064 (2003), RTP: A Transport Protocol for Real-Time Applications . | +| [W3C XML 1.0] | W3C XML 1.0 (2008), Extensible Markup Language (XML) 1.0 , (Fifth Edition). | +| [W3C XML Schema] | W3C XML Schema (2004), XML Schema Part 2: Datatypes Second Edition , W3C Recommendation 28 October 2004. | + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 adaptive differential pulse code modulation (ADPCM)** [b-ITU-T G.701]: ADPCM algorithms are compression algorithms that achieve bit rate reduction through the use of adaptive prediction and adaptive quantization. + +**3.1.2 multipurpose Internet mail extensions (MIME)** [b-ITU-T J.200]: An application layer protocol. It features a content architecture to facilitate multimedia data such as text other than US-ASCII code, sound, image, etc. to be handled in Internet mails. + +**3.1.3 pulse code modulation (PCM)** [b-ITU-T J.177]: A commonly-employed algorithm to digitize an analog signal (such as a human voice) into a digital bit stream using simple analog-to-digital conversion techniques. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 automatic speech recognition (ASR)**: A system that can recognize continuous speech, often having phoneme-sized references, using lexical, syntactic, semantic, and pragmatic knowledge, and reacts appropriately (therefore having interpreted the message and found the corresponding action to be taken). [b-ITU-T P.10] + +**3.2.2 machine translation (MT)**: Text in a source language is converted by computers into text in a target language which has the same meaning as the original text in the source language. + +**3.2.3 modality conversion (MC)**: The conversion of data to different formats/languages using ASR, MT and TTS systems. + +**3.2.4 modality conversion markup language (MCML)**: An XML schema that serves as a data description for data exchanged among modality conversion modules. + +**3.2.5 modality conversion protocol (MCP)**: The communication protocol which transfers data between MC clients and servers using HTTP(S)/RTP [IETF RFC 2616], [IETF RFC 2818], [IETF RFC 3550]. This protocol transfers the MCML comprised of multimodal information (MI) data which is input into MC clients by users and MC results which are obtained by MC servers. + +**3.2.6 multimodal information (MI)**: The information input into MC clients by users via multimodal sensors. + +**3.2.7 N-best**: The most likely "N" hypotheses obtained from modality conversion engines. + +**3.2.8 speech-to-speech translation (S2ST)**: Speech in a source language is translated into speech in a target language. + +**3.2.9 text-to-speech (TTS) synthesis:** A process that generates a speech signal from text codes. It is usually composed of the parts: a language-dependent text processing part (the high level processing part), which generates from the character string (by reading rules, vocabulary and semantic analysis) and a set of phonetic, prosodic, etc., parameters that are used by an acoustical signal generating part, the synthesiser itself, which produces the audible speech. [b-ITU-T P.10] + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-------|---------------------------------------------| +| ADPCM | Adaptive Differential Pulse Code Modulation | +| ASR | Automatic Speech Recognition | +| HTTP | HyperText Transfer Protocol | +| HTTPS | HyperText Transfer Protocol Secure | +| ID | Identifier | +| MC | Modality Conversion | +| MCML | Modality Conversion Markup Language | +| MCP | Modality Conversion Protocol | +| MI | Multimodal Information | +| MIME | Multipurpose Internet Mail Extensions | +| MT | Machine Translation | +| PCM | Pulse Code Modulation | +| RTP | Real Time Protocol | +| S2ST | Speech-To-Speech Translation | +| TTS | Text-To-Speech | +| UCS | Universal Character Set | +| UTF-8 | UCS Transformation Format-8 | +| XML | Extensible Markup Language | + +# **5 Conventions** + +In this Recommendation: + +- The expression "is required to" indicates a requirement which must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. +- The expression "is recommended to" indicates a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. +- The expression "can optionally" indicates an optional requirement which is permissible, without implying any sense of being recommended. + +# 6 High-level functional model and generic service description + +## 6.1 System overview + +The objective of this clause is to describe the high-level functional model of network-based S2ST, in a combination of multiple MC clients and servers. Figure 6-1 shows the functional model for a network-based S2ST. + +The functional architecture for network-based S2ST systems requires the following components: S2ST clients and S2ST servers, such as ASR, MT and TTS servers. The S2ST clients are MC clients, which request modality conversion of multimodal information inputted by users to MC servers and which receive the modality conversion results from MC servers. The ASR, MT and TTS servers are MC servers that convert the modality of the multimodal information (MI) input by users. + +To achieve the above communication between MC clients and servers, a communication protocol is required, namely the modality conversion protocol (MCP) with the modality conversion markup language (MCML). Based on communication via MCP, MCP clients send MCML to the MCP servers, and MCP servers receive MCML from the MCP clients. The above architecture for the network-based S2ST can also be set up in a standalone system in which MCML is used as an internal interface. + +## 6.2 Functional model of modality conversion (MC) through communication between modality conversion protocol (MCP) clients and servers + +The architecture of modality conversion (MC) is shown below in Figure 6-2, which is further elaborated in [ITU-T H.625]. Figure 6-2 shows the functional architecture of MCP clients and servers. This architecture is simply specified in a single MCP client and server combination. Each of the engines for ASR, MT and TTS is identified as a modality conversion function in the MCP server. + +The following functions are required within both MCP clients and servers: + +- MI processing function; +- MCML processing function; +- communication processing function. + +An input and output processing function for MI is required within MCP clients, and a modality conversion (MC) function is required within MCP servers. + +![Functional model of a network-based S2ST system showing clients and servers connected via a central network cloud.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +The diagram illustrates the functional model of a network-based S2ST (Speech-to-Speech Translation) system. At the center is a blue cloud labeled "Private/wide area public communication network". + +On the left, two "MC client" boxes are shown. Each contains an "S2ST client" (for language A or B speaker) and a "Conversion between speech and speech signal" component. These clients are connected to the central network cloud. Between the two clients is a double-headed arrow labeled "Communication between users who speak different languages". + +On the right, six "MC server" boxes are shown, each connected to the central network cloud. Each MC server contains a specific component: + + +- ASR server: Conversion from speech signal to text in language A +- MT server: Conversion from text in language A to text in language B +- TTS server: Conversion text to speech signal in language B +- ASR server: Conversion from speech signal to text in language B +- MT server: Conversion from text in language B to text in language A +- TTS server: Conversion text to speech signal in language A + +F.745(16)\_F6-1 + +Functional model of a network-based S2ST system showing clients and servers connected via a central network cloud. + +Figure 6-1 – Functional model of a network-based S2ST + +![Figure 6-2: Architecture of modality conversion clients and servers. The diagram shows an MCP client and an MCP server connected via a 'Private/wide area public communication network' labeled 'MCP'. On the left, 'Multimodal information (MI)' is input to the 'Input and output processing function' of the 'MCP client'. This function is connected to three internal functions: 'MI processing function', 'MCML processing function', and 'Communication processing function'. The 'Communication processing function' connects to the 'MCP' network. On the right, the 'MCP' network connects to the 'Communication processing function' of the 'MCP server'. This function is connected to three internal functions: 'MI processing function', 'MCML processing function', and 'Modality conversion (MC) function'. The 'MI processing function' and 'MCML processing function' are also connected to the 'Modality conversion (MC) function'. The diagram is labeled 'F.745(16)_F6-2' in the bottom right corner.](d4af765160d04ecef538e5066006dc77_img.jpg) + +Figure 6-2: Architecture of modality conversion clients and servers. The diagram shows an MCP client and an MCP server connected via a 'Private/wide area public communication network' labeled 'MCP'. On the left, 'Multimodal information (MI)' is input to the 'Input and output processing function' of the 'MCP client'. This function is connected to three internal functions: 'MI processing function', 'MCML processing function', and 'Communication processing function'. The 'Communication processing function' connects to the 'MCP' network. On the right, the 'MCP' network connects to the 'Communication processing function' of the 'MCP server'. This function is connected to three internal functions: 'MI processing function', 'MCML processing function', and 'Modality conversion (MC) function'. The 'MI processing function' and 'MCML processing function' are also connected to the 'Modality conversion (MC) function'. The diagram is labeled 'F.745(16)\_F6-2' in the bottom right corner. + +**Figure 6-2 – Architecture of modality conversion clients and servers** + +### 6.2.1 Modality conversion markup language + +Modality conversion markup language (MCML) is formatted in XML [W3C XML 1.0], which contains the information exchanged between MC clients and servers. UTF-8 [IETF RFC 2279] encoded text is required for MCML. + +MCML includes: + +- user information of MC clients, such as ID, age and gender; +- device information of MC clients, such as URI [IETF RFC 2396]; +- MI input into MC clients by users; +- type of services, device information and order of processes of MC servers; +- MC results obtained from MC servers; +- history of MC services. + +### 6.2.2 Modality conversion protocol + +Modality conversion protocol (MCP) is a communication protocol based on HTTP [IETF RFC 2616] or HTTPS [IETF RFC 2818]. To handle real-time streaming, RTP [IETF RFC 3550] is used as an option. MCML and binary data are embedded into the multipurpose Internet mail extensions (MIME) format for transfer. + +### 6.2.3 Multimodal information + +MCML is required to be expandable for more complicated modality conversion, to achieve communication using multiple modalities. Information input from users using multiple modalities is defined as multimodal information (MI). + +#### 6.2.4 MCP client + +Clients that communicate via MCP are denoted as MCP clients and have the following functions: + +- send requests formatted in MCML to MCP servers; and +- receive MCML, including MC results, that are sent by MCP servers. + +#### 6.2.5 MCP server + +Servers that communicate via MCP are denoted as MCP servers and have the following functions: + +- receive requests formatted in MCML that are sent by MCP clients; and +- send MCML data, including MC results, to MCP clients. + +#### 6.2.6 MC client + +A modality conversion (MC) client operates by requesting modality conversion of the multimodal information (MI) which is input by users. The MC client has two different functions: + +- transfer function for user and device information, and MI input by users; and +- receive function for MC results from MC servers. + +When different devices are used for transmitters and receivers, the functions of MC client can be performed by switching between the MCP client and the MCP server modes. + +#### 6.2.7 MC server + +A modality conversion (MC) server operates by receiving requests for modality conversion of the multimodal information (MI) that comes from MC client users. The MC server contains MC engines, such as ASR, MT and TTS, which enable modality conversion. In the case where an MC server transfers MC results to another MC server directly through an MC relay communication, the sender MC server uses the MCP client mode. + +## 6.3 Service description + +The service defined in this Recommendation enables users to leverage network-based S2ST in a pragmatic manner. Appendix I describes three examples of network-based S2ST services. This service is generically realized by the following operations: + +- 1) Speech is input by users to S2ST clients. +- 2) S2ST clients send device and speech information to ASR servers. +- 3) Speech in source language is recognized by ASR servers. +- 4) The recognized speech is encoded by ASR servers and transferred to MT servers. +- 5) The encoded speech is translated from the source language into the target language by MT servers. +- 6) The translation results are transferred to TTS servers. +- 7) The translation results are converted into speech in the target language by TTS servers. +- 8) The speech generated by TTS is transferred to S2ST clients. + +The MI processing function encodes the MI digitized by the input and output processing function into feature expressions. This function can be implemented either in the MCP client or the MCP server. + +# 7 Requirements + +This clause provides a list of basic requirements for services of network-based S2ST. Network-based S2ST has the following requirements in terms of user input, network, user device, MC client, MC server, quality, codec, security and privacy. + +## 7.1 User input requirements + +**USR-001:** This service is required to be usable by people who speak different languages, in face-to-face or remote communication scenarios. + +**USR-002:** This service is recommended to be usable by people who communicate in various modalities, including verbal communication and sign language. + +## 7.2 Network requirements + +**NW-001:** This service requires the network to provide bandwidth and speed sufficient to transfer MI (such as speech and video data) between MCP clients and servers to accomplish real-time communication. + +## 7.3 User device requirements + +**USR device-001:** It is recommended that the user device for this service be usable by people who communicate in various modalities, including verbal communication and sign language. + +**USR device-002:** It is required that the user device for this service include input processors to digitize MI, which is generated through the use of sensing tools such as microphones, keyboards, cameras, etc. + +**USR device-003:** The user device for this service can optionally include an encoding function where the encoding method corresponds to what the server designates. + +**USR device-004:** It is required that the user device for this service include the ability to perform the following MCML processing functions: + +- embed digitized/encoded MI into MCML format; and +- extract MC results obtained by the MC server from MCML data. + +**USR device-005:** It is required that the communication processor for the user device in this service include the ability to operate as an MCP client to transfer the MCML to MC servers. + +**USR device-006:** It is required that the communication processor for the user device in this service include the ability to operate as an MCP server to receive the MCML from MC servers. + +**USR device-007:** It is required that the user device for this service include output processors to reproduce MI from the MC server output, such as ASR, MT and TTS results through the use of loudspeaker, display, etc. + +## 7.4 Modality conversion (MC) client requirements + +**MC client-001:** It is required that the MC client be capable of handling multiple user profiles in shared client devices. + +**MC client-002:** It is required that the MC client be capable of setting up the order of MC processes. + +**MC client-003:** It is required that the MC client be capable of connecting/routing messages to multiple clients and servers. + +**MC client-004:** It is recommended that the MC client be capable of getting information on the physical location of the MC device. + +## 7.5 Modality conversion (MC) server requirements + +**MC server-001:** It is required that the communication processor for the MC servers in this service include the ability to operate as an MCP server to receive the MCML from MC clients or servers. + +**MC server-002:** It is required that the MC server for this service have the ability of encoding digitized MI. In case the user device optionally carries out the encoding, the MC server is required to accept the encoded results. + +**MC server-003:** It is required that the MC server for this service use MC functions, i.e., ASR, MT, TTS, etc. + +**MC server-004:** It is required that the user device for this service include the ability to perform the following MCML processing functions: + +- embed digitized/encoded MI into MCML format; and +- extract MC results obtained by the MC server from MCML data. + +**MC server-005:** It is required that the communication processor for user devices in this service include the ability to operate as an MCP client to transfer the MCML to MC servers. + +## **7.6 Quality requirements** + +**QLT-001:** It is required that this service be equipped with enough capability to perform each of the processes of ASR, MT and TTS. Real time processing for S2ST is recommended to realize spontaneous communication between users who use an MC client or MC clients. + +## **7.7 Security and privacy requirements** + +The requirements of this function are for further study. + +## **7.8 Codec requirements** + +The requirements of this function are for further study. + +# Appendix I + +## Service description in applications + +(This appendix does not form an integral part of this Recommendation.) + +### **I.1 Shared speech-to-speech translation (S2ST) client of two-party communication** + +S2ST provides two-party communication using a shared application terminal. In this service, speech-to-speech translation can be performed for two-party communication. Multi-party communication can also be provided, although processing of translation is not performed in a simultaneous manner, but in sequential steps. This set-up can be used only for face-to-face communication shown in Figure I.1. + +### **I.2 Personal speech-to-speech translation (S2ST) client communication** + +S2ST provides users with both two-party and multi-party communication using personal application terminals. This service can also be performed remotely if the application is used in two-party communication, where the speech translation results of one user can be distributed to multiple users in multiple languages at the same time. This set-up can be used for both face-to-face and remote communication shown in Figure I.1. + +### **I.3 Cross-modality communication** + +S2ST provides different modality communication between users. For instance, a person who uses the spoken word can communicate with a counterpart who is using sign language through the S2ST system. Text-input users can also converse with someone who uses sign language. + +![Diagram illustrating speech translation for face-to-face and remote communication. It is divided into two main sections: 'Face-to-Face communication' and 'Remote communication'. Each section shows two people, one speaking 'Language A' and the other 'Language B', interacting via a mobile device. In the face-to-face section, they use a 'Single device' or a 'Private network' of two 'Personal devices'. In the remote section, they use 'Personal devices' connected via a 'Network' cloud.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg) + +**Face-to-Face communication** + +The top part of the diagram shows two people in suits. The person on the left has a speech bubble labeled **Language A** and is holding a smartphone labeled **Single device**. The person on the right has a speech bubble labeled **Language B**. They are standing close together, indicating face-to-face interaction. + +The bottom part of the face-to-face section shows the same two people, each with their own **Personal device**. They are connected by a double-headed arrow labeled **Private network**, showing a direct peer-to-peer connection between their devices. + +**Remote communication** + +The bottom section of the diagram shows the two people separated by a cloud labeled **Network**. Each person has a **Personal device** connected to the network cloud by a double-headed arrow. The person on the left speaks **Language A** and the person on the right speaks **Language B**, with their communication being mediated through the network. + +F.745(16)\_FI.1 + +Diagram illustrating speech translation for face-to-face and remote communication. It is divided into two main sections: 'Face-to-Face communication' and 'Remote communication'. Each section shows two people, one speaking 'Language A' and the other 'Language B', interacting via a mobile device. In the face-to-face section, they use a 'Single device' or a 'Private network' of two 'Personal devices'. In the remote section, they use 'Personal devices' connected via a 'Network' cloud. + +**Figure I.1 – Speech translation for face-to-face and remote communication** + +# Bibliography + +- [b-ITU-T G.701] Recommendation ITU-T G.701 (1993), *Vocabulary of digital transmission and multiplexing, and pulse code modulation (PCM) terms.* +- [b-ITU-T J.177] Recommendation ITU-T J.177 (2003), *IPCablecom CMS subscriber provisioning specification.* +- [b-ITU-T J.200] Recommendation ITU-T J.200 (2001), *Worldwide common core – Application environment for digital interactive television services.* +- [b-ITU-T P.10] Recommendation ITU-T P.10 (1998), *Vocabulary of terms on telephone transmission quality and telephone sets.* + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.746.1-201410-I_PDF-E/1d7527f4316cfe2d342b08d1653d1592_img.jpg b/marked/F/T-REC-F.746.1-201410-I_PDF-E/1d7527f4316cfe2d342b08d1653d1592_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..22dc7ff0fb30f976cc1e576c45d2b7e65fa5ddc7 --- /dev/null +++ b/marked/F/T-REC-F.746.1-201410-I_PDF-E/1d7527f4316cfe2d342b08d1653d1592_img.jpg 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telecommunication services + +Multimedia services + +## --- **Architecture for unified status monitoring systems** + +![ITU logo](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.746.22 + +## Architecture for unified status monitoring systems + +## Summary + +Traditionally, each network provider and multimedia application service provider collects its own status information independently. There is a lack of an efficient way to share such information among them. + +Recommendation ITU-T F.746.22 describes the functional architecture for unified status monitoring (USM) systems, including functional entities, reference points and service control flows. This architecture enables administrators to implement any monitoring system, providing an efficient way to share network-level and application-level information between network providers and multimedia application service providers. It can also share status information among multiple USM systems and can further analyse status information and generate status reports in response to requests from network providers and application service providers. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.746.22 | 2025-12-14 | 21 | 11.1002/1000/16582 | + +## Keywords + +Architecture, parse and synthesize, status information sharing, unified status monitoring. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2026 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|------------------------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation ..... | 1 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Overview..... | 2 | +| 7 Functional architecture for USM systems ..... | 3 | +| 7.1 Overview of functional architecture for USM systems ..... | 3 | +| 7.2 Functional entities of USM systems..... | 3 | +| 8 Reference points ..... | 5 | +| 8.1 Reference points between USM server and agent ..... | 5 | +| 8.2 Reference points between USM agent and network provider or ASP ..... | 5 | +| 8.3 Reference points between USM server and east/west bound interfaces ..... | 6 | +| 8.4 Reference points among internal entities of USM server..... | 6 | +| 9 Service control flows ..... | 8 | +| 9.1 Request and response of basic status information ..... | 8 | +| 9.2 Request and response of dynamic status information ..... | 9 | +| 9.3 Request and response of unified status report ..... | 10 | +| 9.4 Cooperation between USM servers ..... | 11 | +| 10 Security Consideration..... | 11 | +| Bibliography..... | 12 | + + + +# Recommendation ITU-T F.746.22 + +## Architecture for unified status monitoring systems + +# 1 Scope + +This Recommendation specifies the architecture for unified status monitoring (USM) systems, which satisfies the requirements specified in [ITU-T F.746.8]. It is capable of collecting raw status information and, upon request, providing the user with processed information. It also supports status information sharing amongst participants. + +This Recommendation covers the following: + +- Functional architecture for USM systems; +- Functional entities, reference points, and service control flows of USM systems. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T F.746.8] Recommendation ITU-T F.746.8 (2018), *Requirements for unified status monitoring of networks and services*. + +[ITU-T Y.2201] Recommendation ITU-T Y.2201 (2009), *Requirements and capabilities for ITU-T NGN*. + +[ITU-T Y.2701] Recommendation ITU-T Y.2701 (2007), *Security requirements for NGN release 1*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 unified status monitoring (USM)** [ITU-T F.746.8]: A type of monitoring which allows network providers and application service providers to get the status information they need in a unified way. + +**3.1.2 network provider** [b-ITU-T H.780]: The organization that maintains and operates the network components required to support a service or set of services. + +**3.1.3 application service provider (ASP)** [b-ITU-T H.360]: A service provider providing application services. + +## 3.2 Terms defined in this Recommendation + +None. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-----|-----------------------------| +| ASP | Application Service Provide | +| E/W | East/West | +| FE | Functional Entity | +| I/O | Input/Output | +| QoS | Quality of Service | +| USM | Unified Status Monitoring | + +# 5 Conventions + +This Recommendation uses the following convention which is specific to this Recommendation: + +**Functional entity:** In the context of the USM system architecture, a "functional entity" is defined as a group of functionalities that has not been further subdivided at the level of detail described in this Recommendation. It is represented by the following symbol: + +![A rectangular box containing the text 'Functional entity'.](5860ad6bd2a2dd8d1ab12864b8f90f37_img.jpg) + +A rectangular box with a black border, containing the text "Functional entity" centered inside it. + +A rectangular box containing the text 'Functional entity'. + +# 6 Overview + +Traditionally, each network provider and multimedia application service provider (ASP) collects its own status information independently. On one hand, the network provider can collect network-level information, including routing path, round-trip time and so on. For example, with the development of on-chip multi-wavelength light source technology based on the integrated Kerr optical comb [b-Geng], network providers can use dedicated wavelengths to establish optical monitoring paths, quickly detect topological changes caused by network failures [b-Wu] and re-establish new optical paths. Similarly, in advanced space-integrated-ground information networks, the incorporation of multimodal communication paradigms (i.e., optical/electric) facilitates the establishment of diverse Quality of service (QoS)-guaranteed transmission paths by network providers. If multimedia ASPs can obtain this network-level information provided by network providers in a timely fashion, they can quickly switch network paths, thereby ensuring the QoS perceived by users. On the other hand, multimedia ASPs can quickly detect application-level status, such as changes in traffic volume. If network providers can simultaneously obtain this information, they can rapidly establish new optical paths or use appropriate communication methods to carry the traffic. + +However, there is a lack of an efficient way to share such information among them. [ITU-T F.746.8] describes requirements and the preliminary functional architecture for a unified status monitoring (USM) system which allows network providers and multimedia ASPs to get the status information they need. The Recommendation has laid a solid foundation for the subsequent development of related recommendations. This Recommendation focuses on the more detailed architecture for USM systems, including functional entities, reference points, and service control flows based on [ITU-T F.746.8]. More than one USM server is required to support the USM service in a large network. east/westbound (E/W) input/output (I/O) among multiple USM servers, data merging, and status report template entities will be specified in this Recommendation. Detailed information about northbound, southbound I/O will also be given. + +# 7 Functional architecture for USM systems + +## 7.1 Overview of functional architecture for USM systems + +This clause describes the functional architecture which is required to perform USM functionalities. A USM system consists of a USM server and a set of USM agents, deploying a dedicated agent to interact with each network provider or multimedia ASP. Furthermore, to support large-scale environments, multiple USM systems are required to cooperate and provide the necessary USM services. + +Figure 1 shows the functional architecture with the functional entities, reference points between different functional entities and service control flows. It includes the functional entities of the USM server and the USM agent, as well as the reference points between different functional entities and the network provider or multimedia ASP. It also uses coloured arrows to show the service control flows for the request and response of basic status information, the request and response of dynamic status information, the request and response of unified status report information, requests from other USM servers for status reports and requests from other USM servers for static and dynamic information. + +![Figure 1: Detailed functional architecture for USM systems with reference points and service control flows. The diagram shows the internal components of a USM system (USM server and USM agent) and their interactions with external entities like USM system 2 and Network provider/Application service provider. It includes functional entities such as Unified status interface, Parse/synthesize, Unified data management, Data merging, Static information interface, Dynamic information interface, Supplement information management, Dynamic information management, and Static information management. Service control flows are represented by colored arrows: red dashed for basic status, yellow dashed for dynamic status, green dashed for unified status, purple dashed for other USM server requests, and blue dash-dot for other USM server static/dynamic requests. Reference points are labeled with 'I' followed by specific identifiers (e.g., Isus, Ipe, Ipm, Imd, Idd, Isp, Ipu, Ipm, Imd, Idd, Isp).](7a0db9703b68b3d06cdaeefc084c0006_img.jpg) + +**Legend:** + +- Request and response of basic status information (Red dashed line) +- Request and response of dynamic status information (Yellow dashed line) +- Request and response of unified status report information (Green dashed line) +- Other USM servers request the status report (Purple dashed line) +- Other USM servers request the static and dynamic information (Blue dash-dot line) +- Functional entity (Solid rectangle) +- A collection of functional entities (Dashed rectangle) +- Network provider/Application service provider (Dashed rectangle) +- USM system (Dashed rectangle) + +F.746.22(25) + +Figure 1: Detailed functional architecture for USM systems with reference points and service control flows. The diagram shows the internal components of a USM system (USM server and USM agent) and their interactions with external entities like USM system 2 and Network provider/Application service provider. It includes functional entities such as Unified status interface, Parse/synthesize, Unified data management, Data merging, Static information interface, Dynamic information interface, Supplement information management, Dynamic information management, and Static information management. Service control flows are represented by colored arrows: red dashed for basic status, yellow dashed for dynamic status, green dashed for unified status, purple dashed for other USM server requests, and blue dash-dot for other USM server static/dynamic requests. Reference points are labeled with 'I' followed by specific identifiers (e.g., Isus, Ipe, Ipm, Imd, Idd, Isp, Ipu, Ipm, Imd, Idd, Isp). + +**Figure 1 – Detailed functional architecture for USM systems with reference points and service control flows** + +## 7.2 Functional entities of USM systems + +This clause describes the functional entities (FEs) for the USM systems. + +### 7.2.1 Functional Entities of USM server + +The USM server is responsible for managing status information. The USM server consists of the parse/synthesize FE, data merging FE, unified data management FE, and status report templates FE. It interacts with the USM agent through the unified status interface, static information interface, and dynamic information interface, and also has east/west interfaces with other USM systems. + +#### a) Data merging FE + +The data merging FE is used to filter and merge the received static and dynamic information to remove redundant and outdated information. + +#### b) Unified data management FE + +The unified data management FE is responsible for storing both static and dynamic information that are collected from network providers and multimedia ASPs through the static information interface and the dynamic information interface. + +##### c) Parse/synthesize FE + +The parse/synthesize FE is used to parse the status request, which is received from the unified status interface. Then it retrieves the needed raw status data by querying the unified data management FE of the USM server as well as the dynamic information management FE of one or more USM agents if necessary. After collecting all needed raw status data, the parse/synthesize FE will synthesize this data, generate a report using status report templates, and send back the generated reports. + +#### d) Status report templates FE + +The status report templates FE is responsible for providing report templates to the parse/synthesize FE to generate the status report. + +### 7.2.2 Functional entities of USM agent + +The USM agent consists of the static information management FE, the dynamic information management FE, and the supplementary information management FE. The USM agent is designed to interact with a network provider or a multimedia ASP on behalf of the USM server. With these three functional entities, each network provider or multimedia ASP can share the collected status information with the others. + +#### a) Static information management FE + +The static information management FE is used to send requests and receive static status information, such as network topology or locations of application servers, from a network provider or multimedia ASP. It then performs format conversion of the collected information and forwards the converted information in a standard format to the USM server. + +#### b) Dynamic information management FE + +The dynamic information management FE is responsible for querying dynamic status information (e.g., real-time raw status data of providers, which are collected periodically or according to an inquiry, such as round-trip delay and traffic demand) and sending the retrieved status data to the USM server. + +#### c) Supplementary information management FE + +The supplementary information management FE is responsible for requesting status reports from the USM server on behalf of network providers and multimedia ASPs and returning the received status reports. Network providers can use such information for further optimization. + +# **8 Reference points** + +## **8.1 Reference points between USM server and agent** + +### **8.1.1 Reference point Isss: USM agent static information management FE – USM server static information interface** + +The reference point is located between the static information management FE of the USM agent and the static information interface of the USM server. It is used to deliver static information, e.g., network topology collected by a network provider, to the USM server. + +### **8.1.2 Reference point Isdd: USM agent dynamic information management FE – USM server dynamic information interface** + +The reference point is located between the dynamic information management FE of the USM agent and the dynamic information interface of the USM server. It is used to deliver dynamic information collected by a network provider or ASP periodically or according to the USM server's inquiries. + +### **8.1.3 Reference point Isdd': USM server dynamic information interface – USM agent dynamic information management FE** + +The reference point is located between the dynamic information interface of the USM server and the dynamic information management FE of the USM agent. It is used to deliver inquiries for dynamic information, which will be collected on demand from the USM server, to the USM agents. + +### **8.1.4 Reference point Isus: USM agent supplement information management FE – USM server unified status interface** + +The reference point is located between the supplementary information management FE of the USM agent and the unified status interface of USM server. It is used to deliver the requests for status reports from the USM agent to the USM server. + +### **8.1.5 Reference point Isus': USM server unified status interface – USM agent supplement information management FE** + +The reference point is located between the unified status interface of the USM server and the supplementary information management FE of the USM agent. It is used to deliver the required status reports from the USM server to the USM agent. + +## **8.2 Reference points between USM agent and network provider or ASP** + +### **8.2.1 Reference point Iami: network provider/ASP – USM agent static information management FE** + +The reference point is located between a network provider/ASP and the static information management FE of the USM agent. It is used to deliver the static information, including network topology collected by a network provider or application traffic volume collected by an ASP, to the USM agent. + +### **8.2.2 Reference point Iamo: USM agent static information management FE – network provider/ASP** + +The reference point is located between the static information management FE of the USM agent and a network provider/ASP. It is used to deliver the request for collecting static information, including network topology collected by a network provider or application traffic volume collected by an ASP. + +### **8.2.3 Reference point Iado: USM agent dynamic information management FE–network provider/ASP** + +The reference point is located between the dynamic information management FE of the USM agent and the network provider/ASP. It is used to deliver inquiries for dynamic information, which will be collected on demand from the USM agent to network provider/ASP. + +#### **8.2.4 Reference point Iadi: network provider/ASP– USM agent dynamic information management FE** + +The reference point is located between the network provider/ASP and the dynamic information management FE of the USM agent. It is used to deliver the dynamic information collected by the network provider or ASP, either periodically or in response to inquiries. + +### **8.2.5 Reference point Iaso: USM agent supplement information management FE – network provider/ASP** + +The reference point is located between the supplement information management FE of the USM agent and the network provider/ASP. It is used to deliver the required status report from the USM agent to the network provider/ASP. + +### **8.2.6 Reference point Iasi: network provider/ASP – USM agent supplement information management FE** + +The reference point is located between the network provider/ASP and the supplementary information management FE of the USM agent. It is used to deliver requests for status reports from the network provider/ASP to the USM agent. + +## **8.3 Reference points between USM server and east/west bound interfaces** + +#### **8.3.1 Reference point Iem: east/west interface – USM server unified data management FE** + +The reference point is located between the east/west interface and the unified data management FE of the USM server. It is used to deliver requests for both static and dynamic information stored in the USM server. + +### **8.3.2 Reference point Ime: USM server unified data management FE – east/west interface** + +The reference point is located between the unified data management FE of the USM server and the east/west interface. It is used to deliver the static information and dynamic information stored in the USM server to other USM servers. + +### **8.3.3 Reference point Iep: east/west interface – USM server parse/synthesize FE** + +The reference point is located between the east/west interface and the parse/synthesize FE of the USM server. It is used to deliver the request for the status report from other USM server to this USM server. + +### **8.3.4 Reference point Ipe: USM server parse/synthesize FE – east/west interface** + +The reference point is located between the parse/synthesize FE of the USM server and the east/west interface. It is used to deliver the requested status report from this USM server to other USM servers. + +## **8.4 Reference points among internal entities of USM server** + +### **8.4.1 Reference point Iup: USM server unified status interface – USM server parse/synthesize FE** + +The reference point is located between the unified status interface of the USM server and the parse/synthesize FE of USM server. It is used to deliver the status report requirements from the unified status interface on behalf of the USM agent to the parse/synthesize FE of the USM server. + +### **8.4.2 Reference point Ipu: USM server parse/synthesize FE – USM server unified status interface** + +The reference point is located between the parse/synthesize FE of USM server and the unified status interface of the USM server. It is used to deliver the required status report from the parse/synthesize FE of the USM server to the USM agent through the unified status interface. + +### **8.4.3 Reference point Ipm: USM server parse/synthesize FE – USM server unified data management FE** + +The reference point is located between the parse/synthesize FE of the USM server and the unified data management FE of USM server. It is used to deliver the requirement for stored data from the parse/synthesize FE of the USM server to the unified data management FE. + +#### **8.4.4 Reference point Imp: USM server unified data management FE – USM server parse/synthesize FE** + +The reference point is located between the unified data management FE of the USM server and the parse/synthesize FE of the USM server. It is used to deliver the required data from the unified data management FE of the USM server to the parse/synthesize FE. + +#### **8.4.5 Reference point Ips: USM server parse/synthesize FE – USM server status report template FE** + +The reference point is located between the parse/synthesize FE of the USM server and the status report template FE of the USM server. It is used to deliver the requests for status report templates from the parse/synthesize FE to the status report template FE of the USM server. + +#### **8.4.6 Reference point Isp: USM server status report template FE – USM server parse/synthesize FE** + +The reference point is located between the status report template FE of the USM server and the parse/synthesize FE of the USM server. It is used to deliver the required status report template from the status report template FE of the USM server to the parse/synthesize FE. + +#### **8.4.7 Reference point Imd: USM server unified data management FE – USM server data merging FE** + +The reference point is located between the unified data management FE of the USM server and the data merging FE of the USM server. It is used to deliver the data requirement from the unified data management FE of the USM server to the data merging FE. + +#### **8.4.8 Reference point Idm: USM server data merging FE – USM server unified data management FE** + +The reference point is located between the data merging FE of the USM server and the unified data management FE of the USM server. It is used to deliver the required data from the data merging FE of the USM server to the unified data management FE. + +#### **8.4.9 Reference point Isd: USM server static information interface– USM server data merging FE** + +The reference point is located between the static information interface of the USM server and the data merging FE of the USM server. It is used to deliver the static information from the static information interface of the USM server to the data merging FE. + +### 8.4.10 Reference point Idi: USM server data merging FE – USM server dynamic information interface + +The reference point is located between the data merging FE of the USM server and the dynamic information interface of the USM server. It is used to deliver the dynamic information requirement from the data merging FE of the USM server to the dynamic information interface. + +### 8.4.11 Reference point Iid: USM server dynamic information interface– USM server data merging FE + +The reference point is located between the dynamic information interface of the USM server and the data merging FE of the USM server. It is used to deliver the dynamic information from the dynamic information interface of the USM server to the data merging FE. + +# 9 Service control flows + +## 9.1 Request and response of basic status information + +Figure 2 illustrates the service control flows for the request and response of basic status information. The static information management FE will issue this service control flow periodically to collect static information. + +![Sequence diagram showing service control flows for request and response of basic status information between USM server components, USM agent, and Network provider/Application provider.](16c1175b5f05a4b55e6d396fc51b15b3_img.jpg) + +``` +sequenceDiagram + participant UDM as Unified data management + participant DM as Data merging + participant SII as Static information interface + participant SIM as Static information management + participant NP as Network provider/ Application provider + + Note over UDM, SII: USM server + Note over SIM: USM agent + + SIM->>NP: 1. Send request for static information periodically + NP->>SIM: 2. Reply with the required static information + SIM->>SIM: 3. Convert format + SIM->>SII: 4. Send converted information + SII->>DM: + DM->>DM: 5. Merge Info. + DM->>UDM: 6. Send merged information + UDM->>UDM: 7. Store Info. +``` + +The diagram illustrates the interaction between three main entities: USM server, USM agent, and Network provider/Application provider. The USM server contains three functional elements: Unified data management, Data merging, and Static information interface. The USM agent contains Static information management. The sequence of interactions is as follows: 1. The USM agent sends a request for static information periodically to the Network provider/Application provider. 2. The Network provider/Application provider replies with the required static information to the USM agent. 3. The USM agent converts the format of the received information. 4. The USM agent sends the converted information to the Data merging FE of the USM server through the Static information interface. 5. The Data merging FE merges the information received from multiple USM agents. 6. The Data merging FE sends the merged information to the Unified data management FE. 7. The Unified data management FE stores the information. + +F.746.22(25) + +Sequence diagram showing service control flows for request and response of basic status information between USM server components, USM agent, and Network provider/Application provider. + +**Figure 2 – Service control flows for request and response of basic status information** + +The service control flows for the request and response of basic status information are as follows: + +- Step 1: The USM agent sends a request for basic status information to the network provider/ASP periodically. +- Step 2: The network provider/ASP collects the required static information and sends it to the static information management FE of the USM agent. +- Step 3: The static information management FE of the USM agent converts the received information into a standard format. +- Step 4: The static information management FE of the USM agent sends the converted information to the data merging FE of the USM server through the static information interface. +- Step 5: The data merging FE merges the information received from multiple USM agents. + +- Step 6: The data merging FE sends the merged information to the unified data management FE of the USM server. +- Step 7: The unified data management FE stores the merged static information. + +## 9.2 Request and response of dynamic status information + +Figure 3 depicts the service control flows for the request and response of dynamic status information. + +![Sequence diagram showing service control flows for dynamic status information between USM server, USM agent, and Network provider/Application provider.](7efae06af3af43ffe5d4b956a679cf54_img.jpg) + +``` + +sequenceDiagram + participant USM_server as USM server + participant USM_agent as USM agent + participant Network_provider as Network provider/Application provider + + Note left of USM_server: [Unified data management, Data merging, Dynamic information interface] + Note right of USM_agent: [Dynamic information management] + + USM_server->>USM_agent: 1. Send dynamic information requirement + USM_agent->>USM_agent: 2. Convert format + USM_agent->>Network_provider: 3. Send dynamic information requirement + Network_provider->>Network_provider: 4. Collect the required information + Network_provider->>USM_agent: 5. Reply with the required dynamic information + USM_agent->>USM_agent: 6. Convert format + USM_agent->>USM_server: 7. Reply with the converted information + USM_server->>USM_server: 8. Merge Information + USM_server->>USM_server: 9. Reply with the merged dynamic information + USM_server->>USM_server: 10. Store Info. or reply to other entities + +``` + +The diagram illustrates the interaction between three main components: the USM server, the USM agent, and the Network provider/Application provider. The USM server contains three functional elements: Unified data management, Data merging, and Dynamic information interface. The USM agent contains the Dynamic information management element. The sequence of interactions is as follows: 1. The Unified data management element sends a dynamic information requirement to the Dynamic information management element of the USM agent via the Dynamic information interface. 2. The Dynamic information management element converts the format of the requirement. 3. The converted requirement is sent to the Network provider/Application provider. 4. The Network provider/Application provider collects the required information. 5. The collected information is replied to the Dynamic information management element. 6. The Dynamic information management element converts the format of the received information. 7. The converted information is sent back to the Data merging element of the USM server via the Dynamic information interface. 8. The Data merging element merges the information. 9. The merged information is sent to the Unified data management element. 10. The Unified data management element stores the information or replies to other entities. A label 'F.746.22(25)' is present at the bottom right of the diagram. + +Sequence diagram showing service control flows for dynamic status information between USM server, USM agent, and Network provider/Application provider. + +**Figure 3 – Service control flows for request and response of dynamic status information** + +The service control flows for the request and response of dynamic status information are as follows: + +- Step 1: The unified data management FE of the USM server sends a dynamic information requirement to the dynamic information management FE of the USM agent through the dynamic information interface. +- Step 2: The dynamic information management FE of the USM agent converts the format of the requirement. +- Step 3: The dynamic information management FE of the USM agent sends the converted requirement to the network provider/ASP. +- Step 4: The network provider/ASP collects the required dynamic information. +- Step 5: The network provider/ASP replies with the required dynamic information to the dynamic information management FE of the USM agent. +- Step 6: The dynamic information management FE converts the format of the received dynamic information. +- Step 7: The dynamic information management FE of the USM agent sends the converted dynamic information back to the data merging FE of the USM server through the dynamic information interface. +- Step 8: The data merging FE merges the information received from multiple USM agents. +- Step 9: The data merging FE sends back the merged dynamic information to the unified data management FE. + +- Step 10: The unified data management FE either stores the information or replies to other entities. + +## 9.3 Request and response of unified status report + +Figure 4 shows the service control flows for the request and response of a unified status report. + +![Sequence diagram showing service control flows for request and response of unified status report between USM server, USM agent, and Network provider/Application provider.](1a827b10290f33d4fec04d0e8ef7a897_img.jpg) + +``` + +sequenceDiagram + participant NP as Network provider/Application provider + participant USM_Agent as USM agent + participant USM_Server as USM server + Note right of USM_Server: Status report templates | Parse/Synthesize | Unified status interface + Note right of USM_Agent: Supplementary information management + + NP->>USM_Agent: 1. Send the requirement for the status report + Note right of USM_Agent: 2. Convert format if necessary + USM_Agent->>USM_Server: 3. Send the requirement + Note right of USM_Server: 4. Request static and dynamic information from the data management module + USM_Server->>USM_Server: 5. Request status report template + USM_Server->>USM_Server: 6. Reply with the requested template + Note right of USM_Server: 7. Generate status report + USM_Server->>USM_Agent: 8. Reply with the requested status report + Note right of USM_Agent: 9. Convert format if necessary + USM_Agent->>NP: 10. Reply the required status report + +``` + +The diagram illustrates the service control flows for the request and response of a unified status report. It involves three main entities: USM server, USM agent, and Network provider/Application provider. The USM server contains three functional blocks: Status report templates, Parse/Synthesize, and Unified status interface. The USM agent contains a Supplementary information management block. The sequence of interactions is as follows: 1. The Network provider/Application provider sends a requirement for the status report to the USM agent. 2. The USM agent converts the format if necessary. 3. The USM agent sends the requirement to the USM server through the Unified status interface. 4. The Parse/Synthesize block in the USM server requests static and dynamic information from the data management module. 5. The Parse/Synthesize block requests the status report template from the Status report templates block. 6. The Status report templates block replies with the requested template. 7. The Parse/Synthesize block generates the status report. 8. The Parse/Synthesize block replies with the requested status report to the USM agent through the Unified status interface. 9. The USM agent converts the format if necessary. 10. The USM agent replies the required status report to the Network provider/Application provider. The diagram is labeled F.746.22(25) at the bottom right. + +Sequence diagram showing service control flows for request and response of unified status report between USM server, USM agent, and Network provider/Application provider. + +**Figure 4 – Service control flows for request and response of unified status report** + +The service control flows for the request and response of unified status report are as follows: + +- Step 1: The network provider/ASP sends the requirement for the status report to the supplement information management FE of the USM agent. +- Step 2: The supplementary information management FE converts the format if necessary. +- Step 3: The supplementary information management FE sends the requirement to the parse/synthesize FE of the USM server through the unified status interface. +- Step 4: The parse/synthesize FE begins to parse the requirement and then requests the necessary static and dynamic information from the unified data management FE. If the dynamic information is out-of-date, the unified data management FE will use the service control flows illustrated in Figure 3. +- Step 5: The parse/synthesize FE requests the status report template from the status report templates FE. +- Step 6: The status report templates FE replies with the requested template. +- Step 7: The parse/synthesize FE generates a status report. +- Step 8: The parse/synthesize FE replies with the requested status report to the supplementary information management FE of the USM agent through the unified status interface. +- Step 9: The supplementary information management FE converts the report format if necessary. + +- Step 10: The supplementary information management FE replies with the required status report to the network provider/ASP. + +## 9.4 Cooperation between USM servers + +Figure 5 illustrates the service control flows for cooperation between USM servers. + +![Sequence diagram showing service control flows for cooperation between USM servers. The diagram involves an 'Other USM server' and a 'USM server' which contains three internal components: 'East/West interface', 'Parse/Synthesize', and 'Unified data management'. The sequence of messages is: 1.1. Send the requirement for the status report (from Other USM server to Parse/Synthesize); 1.2. Generate status report using service control flows shown in steps 4-7 of clause 9.3 (internal to Parse/Synthesize); 1.3. Reply with the requested report (from Parse/Synthesize to Other USM server); 2.1. Send the requirement for the static or dynamic information (from Other USM server to Unified data management); 2.2. Query the local database based on the request, and if no data is available, follow the service control flows described in clause 9.2 to get the information (internal to Unified data management); 2.3. Reply with the requested information (from Unified data management to Other USM server). The diagram is labeled F.746.22(25).](8307f6b04df072c9332f9987e034272c_img.jpg) + +Sequence diagram showing service control flows for cooperation between USM servers. The diagram involves an 'Other USM server' and a 'USM server' which contains three internal components: 'East/West interface', 'Parse/Synthesize', and 'Unified data management'. The sequence of messages is: 1.1. Send the requirement for the status report (from Other USM server to Parse/Synthesize); 1.2. Generate status report using service control flows shown in steps 4-7 of clause 9.3 (internal to Parse/Synthesize); 1.3. Reply with the requested report (from Parse/Synthesize to Other USM server); 2.1. Send the requirement for the static or dynamic information (from Other USM server to Unified data management); 2.2. Query the local database based on the request, and if no data is available, follow the service control flows described in clause 9.2 to get the information (internal to Unified data management); 2.3. Reply with the requested information (from Unified data management to Other USM server). The diagram is labeled F.746.22(25). + +**Figure 5 – Service control flows for cooperation between USM servers** + +There are two types of cooperation when another USM server requests a status report: + +- Step 1.1: The parse/synthesize FE of the USM server receives the requirement for the status report through the east/west interface of the USM server from another USM server. +- Step 1.2: The parse/synthesize FE generates a status report using the service control flows shown in steps 4-7 of clause 9.3. +- Step 1.3: The parse/synthesize FE replies with the requested report to the other USM server through the east/west interface. + +When another USM server requests static and dynamic information: + +- Step 2.1: The unified data management FE of the USM server receives the requirement for static or dynamic information from another USM server through the east/west interface of the USM server. +- Step 2.2: The unified data management FE queries the local database based on the request, and if no data is available, it follows the service control flows described in clause 9.2 to get the information. +- Step 2.3: The unified data management FE replies with the requested information to the other USM server. + +# 10 Security Consideration + +It is necessary to consider the security Recommendations [ITU-T Y.2201], [ITU-T Y.2701], and applicable ITU-T X-series, ITU-T Y-series, and ITU-T M-series Recommendations. These Recommendations include access control, authentication, communication security, data integrity, availability and confidentiality. + +# Bibliography + +- [b-ITU-T H.360] Recommendation ITU-T H.360 (2004), *An architecture for end-to-end QoS control and signalling*. +- [b-ITU-T H.780] Recommendation ITU-T H.780 (2012), *Digital signage: Service requirements and IPTV-based architecture*. +- [b-Geng] Geng Y, Zhou H, Han X, Cui W, Zhang Q, Liu B, Deng G, Zhou Q, Qiu K (2022), *Coherent optical communications using coherence-cloned Kerr soliton microcombs*. Nature communications, vol.13, No.1, February, pp. 1070. +- [b-Wu] Wu, B., Ho, P.-H., Yeung, K.L. (2009), *Monitoring trail: On fast link failure localization in all-optical WDM mesh networks*. Journal of Lightwave Technology, vol.27, No.18, May, pp. 4175–4185. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | 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advanced call services with media enhancements** + +![ITU logo](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.746.23 + +# Requirements and framework for advanced call services with media enhancements + +## Summary + +Recommendation ITU-T F.746.23 specifies the requirements and framework for advanced call services with media enhancements. The typical application scenarios of advanced call services with media enhancements are provided in Appendix I. + +Advanced call services with media enhancements are an extension of the existing audio and video call services, allowing the transmission of enhanced media content during a call. The enhanced media content is transmitted through a newly established logical pipe. Enhanced media content includes audio, video, text and other content. Advanced call services with media enhancements enable a lively visual, rich multimedia, highly perceptible, and fully interactive experience for users, providing users with more interactive experiences. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.746.23 | 2025-12-14 | 21 | 11.1002/1000/16583 | + +## Keywords + +Advanced call services, media enhancements. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2026 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|---------------------------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Convention..... | 2 | +| 6 Overview..... | 2 | +| 7 System framework ..... | 3 | +| 8 Requirements ..... | 5 | +| 8.1 Service and capability management requirements ..... | 5 | +| 8.2 Advanced call service platform requirements ..... | 5 | +| 8.3 User equipment requirements..... | 5 | +| 9 Security considerations ..... | 6 | +| Annex A – Service modes of advanced call services with media enhancements ..... | 7 | +| A.1 Overlay media mode..... | 7 | +| A.2 Media injection mode ..... | 7 | +| A.3 Media immerse mode ..... | 8 | +| Appendix I – Scenarios of advanced call services with media enhancements ..... | 10 | +| I.1 Overlay media mode..... | 10 | +| I.2 Media injection mode ..... | 11 | +| I.3 Media immerse mode ..... | 11 | +| Bibliography..... | 12 | + + + +# Recommendation ITU-T F.746.23 + +## Requirements and framework for advanced call services with media enhancements + +# 1 Scope + +This Recommendation specifies the requirements and framework for advanced call services with media enhancements. In particular, this Recommendation covers the following aspects for advanced call services with media enhancements: + +- Overview of advanced call services with media enhancements. +- System framework of advanced call services with media enhancements. +- Requirements of advanced call services with media enhancements. +- Service mode of advanced call services with media enhancements. +- Scenarios of advanced call services with media enhancements in Appendix I. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T G.722.2] Recommendation ITU-T G.722.2 (2003), *Wideband coding of speech at around 16 kbit/s using Adaptive Multi-Rate Wideband (AMR-WB)*. + +[ITU-T H.264] Recommendation ITU-T H.264 (V15) (2024), *Advanced video coding for generic audiovisual services*. + +[ITU-T H.265] Recommendation ITU-T H.265 (V11) (2026), *High efficiency video coding*. + +[ITU-T X.1031] Recommendation ITU-T X.1031 (2008), *Roles of end users and telecommunications networks within security architecture*. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 IP multimedia subsystem (IMS)** [b-3GPP TS 23.002]: The IP multimedia subsystem (IMS) comprises all core network (CN) elements for provision of IP multimedia services comprising audio, video, text, chat, etc., and a combination of them delivered over the packet switched (PS) domain. + +**3.1.2 session initiation protocol (SIP)** [b-IETF RFC 3261]: Application-layer control (signalling) protocol for creating, modifying, and terminating sessions with one or more participants. These sessions include Internet telephone calls, multimedia distribution, and multimedia conferences. + +### 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 advanced call services with media enhancements:** An extension of the traditional audio and video call services, allowing transmission of enhanced media content including audio, video, text and a combination of them during a call. + +**3.2.2 dual-tone multifrequency (DTMF):** Mechanism used to represent a dual-tone multifrequency key press as a named event and to carry it reliably within packets, ensuring that the receiving end can accurately detect and reproduce the corresponding dual-tone multifrequency digit. + +NOTE – Definition based on [b-ITU-T Q.1290]. + +**3.2.3 session initiation protocol information:** Method commonly used in real-world communications to carry mid-session signalling information. + +NOTE 1 – Applications that need to exchange session-related information within a created dialog, also known as application-level information, use these INFO requests. + +NOTE 2 – Definition based on [b-IETF RFC 2976]. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|----------|-----------------------------------------| +| AI | Artificial Intelligence | +| AMR-WB | Adaptive Multi Rate Wide Band | +| AR | Augmented Reality | +| ASR | Automatic Speech Recognition | +| DTMF | Dual-Tone Multi-Frequency | +| IMS | Internet Protocol Multimedia Subsystem | +| SDP | SIP Description Protocol | +| SIP | Session Initiation Protocol | +| SIP INFO | Session Initiation Protocol Information | +| TTS | Text To Speech | +| UE | User Equipment | +| XR | Extended Reality | + +## 5 Convention + +In this Recommendation: + +The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if the conformance to this document is to be claimed. + +The keywords "is recommended" indicate a requirement which is recommended but not absolutely required. Thus, this requirement needn't be present to claim conformance. + +## 6 Overview + +The existing typical call establishes a connection between the caller and the callee. In the case of audio calls, the connection includes an audio channel for transmitting audio content. For video calls, an additional video channel is established within the same connection to transmit the video content captured by the camera. Advanced call services with media enhancements are an extension of the existing call services, allowing the transmission of enhanced media content during a call in an Internet protocol multimedia subsystem (IMS) network. It introduces virtual avatars, augmented reality (AR) specific effects, artificial intelligence (AI) voice recognition, screen sharing, and other features into + +the call. It provides users with enhanced communication and video interaction, enabling real-time multimedia sharing and instant interactions. + +Advanced call services transmit enhanced media content through new logical pipes including an audio pipe, a video pipe and data pipe. There is also a new platform called advanced call services platform, used for signalling and media processing to implement service functions. The contents can be transmitted in logical pipes between the caller, the callee and the platform. Each logical pipe can transmit different content, which may or may not be related to the content transmitted in the audio or video channel originally established by the two calling parties in a typical call process. According to the service content, advanced call services with media enhancements can be categorized into three modes with specific service modes as shown in Figure 7-1, including overlay media mode, injection media mode and immerse media mode. In a typical media processing service flow from end to end, video content is captured by the content provider. After the video is transmitted to the server of advanced call services platform, The video content is decoded and played on the user equipment. + +## 7 System framework + +Advanced call services with media enhancements are based on the services, multimedia content services and related ecosystems. The service and capability management platform, the advanced call service platform and user equipment works together to provide the services. The service and capability management platform includes the advanced call service management functional block and the media enhancement capability functional block. The advanced call service platform includes the media control functional block and the signalling control functional block. The user equipment includes the caller and callee, which are implemented by terminal devices. A reference framework of advanced call services with media enhancements is shown in Figure 7-1. + +![Figure 7-1: Framework of advanced call services with media enhancements. The diagram shows three layers: Service and capability management platform (top), Advanced call service platform (middle), and User equipment (bottom).](7a0db9703b68b3d06cdaeefc084c0006_img.jpg) + +The diagram illustrates the system framework for advanced call services with media enhancements, organized into three horizontal layers: + +- Service and capability management platform (Top Layer):** This layer is divided into two main functional blocks: + - Advanced call service management:** Contains three sub-components: "Service orchestration", "Intelligent recommendation", and "Model inference". + - Media enhancements capabilities:** Contains six sub-components: "ASR/TTS", "Translation", "Digital human driven", "Image recognition", "Video venue", and "AI capability gateway". +- Advanced call service platform (Middle Layer):** This layer contains two main functional blocks: + - Media control:** Receives input from the "Media enhancements" capabilities and interacts with the signalling control. + - Signalling control:** Receives "Service rules" from the "Service orchestration" and "Intelligent recommendation" components, and interacts with the media control and user equipment. +- User equipment (Bottom Layer):** This layer consists of two terminal devices: + - The caller UE** + - The callee UE**Both are connected to the "Signalling control" block via bidirectional arrows. + +Connections between layers: + +- Dashed lines connect "Service orchestration" and "Intelligent recommendation" to "Service rules" in the "Signalling control" block. +- Dashed lines connect the "Media enhancements" capabilities to the "Media control" block. +- Solid bidirectional arrows connect "The caller UE" and "The callee UE" to the "Signalling control" block. + +Figure 7-1: Framework of advanced call services with media enhancements. The diagram shows three layers: Service and capability management platform (top), Advanced call service platform (middle), and User equipment (bottom). + +F.746.23(25) + +**Figure 7-1 – Framework of advanced call services with media enhancements** + +The service and capability management platform provides service management and the capability of media enhancements for the advanced call services. The service and capability management platform implements service rules for the advanced call services platform through various methods such as service orchestration and intelligent recommendation. The media enhancements capabilities functional block provides various media enhancement capabilities such as translation and an AI + +capability engine for media processing. Meanwhile, the media enhancements capabilities functional block supports the media control functions of the advanced call service platform required for different services through different modes, including "overlay, injection, and immersion". + +Advanced call service management: + +- Services orchestration: This refers to the effective coordination in formulating rules to organize and schedule the execution sequence and methods of various call services by formulating rules, avoiding service conflicts and negotiation conflicts, ensuring the orderly execution of advanced call services, and achieving seamless integration of different services and media enhancements during calls, thereby improving the user experience and service effectiveness. This process involves flexible arrangements for new call services, which can meet the higher expectations of users. +- Intelligent recommendation: This implies the employment of intelligent algorithms and recommendation systems to provide customized call service recommendations to users based on the characteristics of users' call behaviour data. Through service recommendations, it helps to improve user satisfaction with call services, make communication experiences more intelligent and tailored to individual needs, and promote business development. +- Model inference: This involves leveraging machine learning and AI models to analyse and optimize call services. By learning from a large amount of data and training models, the system can gain a deeper understanding of user behaviour and preferences. In addition, model inference can also intelligently optimize services based on real-time data and user feedback, continuously improving the quality and efficiency of services. + +Media enhancements capabilities: + +- Automatic speech recognition (ASR) / text to speech (TTS): ASR analyses the voice input and converts it into text, thereby achieving recognition and understanding of voice commands. TTS converts text into speech, allowing the system to respond to users by voice. +- Translation: It endows call services with the ability to overcome language barriers. Users can perform real-time translation between different languages, thereby promoting international communication and cooperation. +- Digital human driving: It provides users with more intelligent and personalized services through natural language processing and human-computer interaction. +- Image recognition: It enables call services to process image information, such as scanning documents or recognizing objects, providing users with more comprehensive information support, and making call services more visually rich. +- Video conference: It provides a real-time multi-party video call function, allowing users to engage in remote conferences and share real-time images and other media content. +- AI capability gateway: It serves as a bridge connecting different AI models and services, allowing various AI capabilities to be seamlessly integrated into advanced call services, providing a more intelligent experience. + +The advanced call service platform performs signalling and media control for advanced call services, completing the service functions during the call. The advanced call service platform interfaces with the service and capability management platform, controlling signals based on the service rules. + +- Media control: It enables connection set-up between user equipment and the advanced call service platform. It supports receiving the media stream from user equipment and transferring it to user equipment after media processing such as re-rendering, media merging, etc. It supports media capability management, media negotiation management, media play control interface, a media file play, media stream transmission, media interaction service, and in-band receiving with number processing, etc. + +- Signalling control: It supports call service establishment, call state processing and configuration. It provides basic service functions including network signalling access, call session management, call flow control and out-of-band receiving and sending number processing, etc. + +User equipment (UE) receives or sends media streams and signalling messages to the advanced call service platform. It provides basic service functions including mobile/fixed network access, network registration and audio and video call, etc., and advanced call service processing functions including service capability indication, service signalling procedure processing, media processing, media display, and user interface interaction. + +- The caller UE: The user equipment which initiates a call. According to the service scenario, it supports initiating audio or video call. +- The callee UE: The user equipment which receives a call. According to the caller initiating service scenario, it supports the corresponding audio or video call. + +## 8 Requirements + +This clause addresses the requirements for advanced call services with media enhancements. + +### 8.1 Service and capability management requirements + +- R-SCMR-01: It is recommended to support service orchestration that enables the delivery of end-to-end services which are on-demand composable, dynamically adjustable, and risk controllable. +- R-SCMR-02: It is recommended to support media enhancement capabilities that enable dynamic loading and unloading, online updating, real-time parameter configuration, version compatibility adaptation. +- R-SCMR-03: It is recommended to support the utilization of third-party media processing capabilities for media processing. + +### 8.2 Advanced call service platform requirements + +- R-ACPR-01: It is required to support session initiation protocol (SIP) signalling interaction. +- R-ACPR-02: It is required to support SIP description protocol (SDP) based media negotiation. +- R-ACPR-03: It is recommended to support the handling of messages related to interactive features, including session initiation protocol information (SIP INFO) messages and in-band dual-tone multi-frequency (DTMF) messages. +- R-ACPR-04: It is recommended to support an enhanced audio media generation capability to directly generate TTS voice information. +- R-ACPR-05: It is recommended to support an enhanced audio media recognition capability to transcribe audio into text by ASR. +- R-ACPR-06: It is required to support audio and video coding form for real-time transcoding capabilities, supporting audio codec adaptive multi-rate wideband (AMR-WB) specified in [ITU-T G.722.2] and video codecs H.264 and H.265 specified in [ITU-T H.264], [ITU-T H.265]. + +### 8.3 User equipment requirements + +- R-UER-01: It is required to support SIP signalling processes and media negotiation with the advanced call service platform. +- R-UER-02: It is recommended to support the handling and transmission of messages related to interactive features, including SIP INFO messages and in-band DTMF messages. + +- R-UER-03: It is recommended to support the playback of audio, video, images, text, and other types of media. +- R-UER-04: It is required to support video and audio codecs specified in [ITU-T H.264], [ITU-T H.265] and AMR-WB specified in [ITU-T G.722.2]. +- R-UER-05: It is recommended to support video display modes, including horizontal, vertical, and full-screen modes. + +## 9 Security considerations + +The following are the security requirements for advanced call services with media enhancements: + +- R-SC-01: It is recommended to ensure that the regular call services are not affected when the advanced call service platform has a malfunction, by using continuous health checks and a bypass mechanism. +- R-SC-02: It is recommended to conduct regular vulnerability scanning and penetration testing to ensure that the advanced call service platform possesses the necessary risk resistance capabilities to maintain system security. +- R-SC-03: It is recommended to ensure that demand system operations and maintenance do not affect the security and integrity of stored information by conducting regular privileged access audits. +- R-SC-04: It is required to implement layered access control functions to restrict unauthorized access to the advanced call service platform, ensuring the security and integrity of content and data which followed [ITU-T X.1031]. +- R-SC-05: It is recommended to ensure user privacy protection in enhanced media content transmission and processing. + +## Annex A + +### Service modes of advanced call services with media enhancements + +(This annex forms an integral part of this Recommendation.) + +This annex describes typical service modes of advanced call services with media enhancements. + +#### A.1 Overlay media mode + +The typical service scenarios of overlay media mode include blur background, virtual background, early media continuation, extended reality (XR) effects, screen sharing, and whiteboarding. The schematic of overlay media type is depicted in Figure A.1. + +![Schematic of overlay media mode showing communication between a Calling party and a Called party via an Advanced call service platform. The diagram illustrates four pipes: Logical pipe (dashed red line), Data pipe (blue line), Video pipe (yellow line), and Audio pipe (green line). The Logical pipe is shown passing through the platform, while the other three pipes pass through the platform's video and audio channels.](ddc7460821484f1ae2835c67955c554c_img.jpg) + +The diagram illustrates the overlay media mode. On the left is a red rounded rectangle labeled 'Calling party'. On the right is a red rounded rectangle labeled 'Called party'. In the center is a pink rounded rectangle labeled 'Advanced call service platform'. Four horizontal lines represent different media pipes: a dashed red line for the 'Logical pipe', a blue line for the 'Data pipe', a yellow line for the 'Video pipe', and a green line for the 'Audio pipe'. The logical pipe passes through the top of the platform. The data pipe passes through the top of the platform. The video pipe passes through the bottom of the platform, labeled 'Video channel'. The audio pipe passes through the bottom of the platform, labeled 'Audio channel'. + +Schematic of overlay media mode showing communication between a Calling party and a Called party via an Advanced call service platform. The diagram illustrates four pipes: Logical pipe (dashed red line), Data pipe (blue line), Video pipe (yellow line), and Audio pipe (green line). The Logical pipe is shown passing through the platform, while the other three pipes pass through the platform's video and audio channels. + +F.746.23(25) + +**Figure A.1 – Schematic of overlay media mode** + +- An additional logical pipe is established. The audio/video/data content transmitted in the logical pipe is independent of the base audio/video content transmitted in the video and audio channels. +- The original audio/video content transmitted in the video and audio channel cannot be changed by contents transmitted in logical pipe. +- Typical service scenario: video background. Each or both device screens of the caller and the callee are presented with a picture or a video that is predefined by the caller or dynamically provided by the service provider during the call. + +#### A.2 Media injection mode + +The typical service scenarios of injection media mode include subtitles and real-time translation. The schematic of the media injection mode is depicted in Figure A.2. + +![Figure A.2 – Schematic of media injection mode. The diagram shows a 'Calling party' (red box) on the left and a 'Called party' (red box) on the right, connected by an 'Advanced call service platform' (pink box) in the center. The platform has four internal pipes: 'Logical pipe' (dashed line), 'Data pipe' (blue line), 'Video pipe' (yellow line), and 'Audio pipe' (green line). External connections include a 'Video channel' (yellow line) and an 'Audio channel' (green line) between the parties. Arrows indicate data flow: from the platform to the parties for the logical pipe, and from the parties to the platform for the video and audio channels. A label 'F.746.23(25)' is in the bottom right corner.](4801720824e4b5e2361a5564f91cfb70_img.jpg) + +Figure A.2 – Schematic of media injection mode. The diagram shows a 'Calling party' (red box) on the left and a 'Called party' (red box) on the right, connected by an 'Advanced call service platform' (pink box) in the center. The platform has four internal pipes: 'Logical pipe' (dashed line), 'Data pipe' (blue line), 'Video pipe' (yellow line), and 'Audio pipe' (green line). External connections include a 'Video channel' (yellow line) and an 'Audio channel' (green line) between the parties. Arrows indicate data flow: from the platform to the parties for the logical pipe, and from the parties to the platform for the video and audio channels. A label 'F.746.23(25)' is in the bottom right corner. + +**Figure A.2 – Schematic of media injection mode** + +- An additional logical pipe is established. The audio/video/data content transmitted in the logical pipe is generated from the base audio/video content transmitted in the video and audio channel. The content transmitted in the audio or video channels is injected to the logical pipe. +- The base audio/video content transmitted in the video and audio channels cannot be changed by logical pipe. +- Typical service scenario: subtitles. The audio content transmitted in the audio channel are injected to the logical pipe and translated into texts. + +#### A.3 Media immerse mode + +The typical service scenarios of media immerse mode include digital avatar and immersive meeting, which utilize the new media pipe to transmit new content and interactive video (data). The immerse media pipe is depicted in Figure A.3. + +![Figure A.3 – Schematic of media immerse mode. The diagram shows a 'Calling party' (red box) on the left and a 'Called party' (red box) on the right, connected by an 'Advanced call service platform' (pink box) in the center. The platform has four internal pipes: 'Logical pipe' (dashed line), 'Data pipe' (blue line), 'Video pipe' (yellow line), and 'Audio pipe' (green line). External connections include a 'Video channel' (yellow line) and an 'Audio channel' (green line) between the parties. Arrows indicate data flow: from the parties to the platform for the logical pipe, and from the platform to the parties for the video and audio channels. A label 'F.746.23(25)' is in the bottom right corner.](a26e142d3df5bef41a84a9dd099d7825_img.jpg) + +Figure A.3 – Schematic of media immerse mode. The diagram shows a 'Calling party' (red box) on the left and a 'Called party' (red box) on the right, connected by an 'Advanced call service platform' (pink box) in the center. The platform has four internal pipes: 'Logical pipe' (dashed line), 'Data pipe' (blue line), 'Video pipe' (yellow line), and 'Audio pipe' (green line). External connections include a 'Video channel' (yellow line) and an 'Audio channel' (green line) between the parties. Arrows indicate data flow: from the parties to the platform for the logical pipe, and from the platform to the parties for the video and audio channels. A label 'F.746.23(25)' is in the bottom right corner. + +**Figure A.3 – Schematic of media immerse mode** + +- An additional logical pipe is established. The audio/video/data content transmitted in the logical pipe is a mixture of the user's original audio/video contents. +- The content transmitted in the original audio or video channels is replaced and substituted by the new content transmitted in logical pipes, which are between the terminal devices and the advanced call services platform. The new content is transmitted through the logical pipe from the advanced call service platform to the terminal devices. + +- Typical service: immersive meeting. The advanced call service platform combines the user's audio/video content with the virtual meeting background, generating new virtual meeting content. The mixed content is sent to users through the additional logical pipe. The original video and audio channels are replaced by the logical pipe. + +## Appendix I + +### Scenarios of advanced call services with media enhancements + +(This appendix does not form an integral part of this Recommendation.) + +This appendix describes typical application scenarios of advanced call services with media enhancements. + +#### I.1 Overlay media mode + +Voice between A and B is delivered transparently through the audio pipe. Typical scenarios are illustrated in Figure I.1 and described as follows. + +- Blur background: It refers to the process of blurring the user's background environment during a call. +- Virtual background: It refers to replacing the user's background environment with an image during a call. It supports users selecting virtual backgrounds from a pre-existing library and also allows users to upload their own images to define their virtual backgrounds. +- Early media continuation: It refers to extending the content from the early media phase (e.g., video ring-back tones) into the call and playing it as a video background silently before and after dialling and answering. +- XR effects: It refers to the capability for users to overlay facial expression stickers on the call interface and choose voice expression effects. +- Screen sharing and whiteboard: It refer to the capability of displaying the current content on the user's phone screen to the other party's call interface during the call. Users can also use features such as drawing tools and erasers to annotate and doodle, and the annotations will be displayed in real-time on the other party's call interface. + +![Figure I.1 – Typical scenarios of overlay media mode. The figure shows five pairs of smartphone screens illustrating different call scenarios: Blur background, Virtual background continuation, Early media, XR effects, and Screen sharing and white board.](0656422bf374a8a7bcc6fe99adc48599_img.jpg) + +The figure displays five pairs of smartphone screens, each illustrating a different overlay media mode scenario during a call. The pairs are arranged in two rows. The top row shows: 1) 'Blur background' where the user's background is blurred; 2) 'Virtual background continuation' where a virtual background is used; 3) 'Early media' showing a video ring-back tone. The bottom row shows: 4) 'XR effects' where facial expression stickers are overlaid; 5) 'Screen sharing and white board' where a list of text is shared and annotated. Each pair shows the caller's and callee's screens with call interface elements like time, battery, and call controls. + +Figure I.1 – Typical scenarios of overlay media mode. The figure shows five pairs of smartphone screens illustrating different call scenarios: Blur background, Virtual background continuation, Early media, XR effects, and Screen sharing and white board. + +F.746.23(25) + +Figure I.1 – Typical scenarios of overlay media mode + +#### I.2 Media injection mode + +A new media pipe is added to deliver new content which is related to the voice on the audio pipe. The new content could be subtitles. Typical scenarios are as follows. + +- Speech-to-Text transcription: It refers to the voice call content being intelligently recognized during the call and converted into subtitles that are superimposed on the user's call interface. Transcription supports dialects. +- Real-time translation: It enables one party or multiple parties to have free conversations across different languages, see Figure I.2. In point-to-point audio and video calls in different languages, real-time translating converts the speech into text. The text translated from the local speech can be displayed on the remote terminal side during the conversation. The translation capability can invoke multiple third-party translation engines. + +![Two smartphone screens showing a video call with real-time translation subtitles.](6cc4a2d5ea0462e4825d57bd689bd2b3_img.jpg) + +The image shows two smartphone screens side-by-side, representing a video call. Both screens display a video feed where the user's face is replaced by a black silhouette. Overlaid on the bottom of each screen are subtitles in two languages: English ("When you are finished typing, remember to save your document") and Chinese ("完成输入后，请记得将文档保存"). The call interface at the bottom of each screen includes a red end-call button and other standard call controls. + +Two smartphone screens showing a video call with real-time translation subtitles. + +Real-time translation + +F.746.23(25) + +Figure I.2 – Typical scenarios of media injection mode + +#### I.3 Media immerse mode + +New media pipes are added in which new content and interactive video (data) among the calling party. The called party and the advanced call platform are delivered. Typical scenarios are illustrated in Figure I.3 and described as follows. + +- Digital avatar: It refers to replacing the user's portrait with a preset digital avatar image presented during the call. +- Immersive meeting: It refers to blending preset digital avatars of users with a virtual meeting scene to create immersive virtual video conferences. + +![Two pairs of smartphone screens showing digital avatar and immersive meeting scenarios.](e0f3606e9c9eee18bc68b713df4eda8a_img.jpg) + +The image displays two pairs of smartphone screens. The left pair, labeled 'Digital avatar', shows a video call where one participant uses a 3D digital avatar of a man with glasses, while the other participant is represented by a silhouette. The right pair, labeled 'Immersive meeting', shows a video conference interface. One screen displays a grid of participants, each with their own digital avatar, in a virtual meeting room. The other screen shows a virtual classroom or lecture hall environment with desks and a chalkboard, where the avatars are seated. + +Two pairs of smartphone screens showing digital avatar and immersive meeting scenarios. + +Digital avatar + +Immersive meeting + +F.746.23(25) + +Figure I.3 – Typical scenarios of media immersion mode + +## Bibliography + +- [b-ITU-T Q.1290] Recommendation ITU-T Q.1290 (1998), *Glossary of terms used in the definition of intelligent networks.* +- [b-3GPP TS 23.002] 3GPP TS 23.002 (2017), *Network architecture* (Release14). +- [b-IETF RFC 2976] IETF RFC 2976 (2000), *The SIP INFO Method.* +- [b-IETF RFC 3261] IETF RFC 3261 (2002), *SIP: Session Initiation Protocol.* + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.746.3-201511-I_PDF-E/0f985b39edc1d52ba3600c438bc8f0a5_img.jpg b/marked/F/T-REC-F.746.3-201511-I_PDF-E/0f985b39edc1d52ba3600c438bc8f0a5_img.jpg new file mode 100644 index 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n a l T e l e c o m m u n i c a t i o n U n i o n + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**F.746.7** + +(08/2018) + +SERIES F: NON-TELEPHONE TELECOMMUNICATION +SERVICES + +Multimedia services + +--- + +**Metadata for an intelligent question answering +service** + +Recommendation ITU-T F.746.7 + +**ITU-T** + +![ITU logo: A globe with a red lightning bolt, next to the text 'International Telecommunication Union'.](1d7527f4316cfe2d342b08d1653d1592_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with a red lightning bolt striking across it. To the right of the globe, the text "International Telecommunication Union" is written in a blue, sans-serif font. + +ITU logo: A globe with a red lightning bolt, next to the text 'International Telecommunication Union'. + +# ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +## **TELEGRAPH SERVICE** + +| | | +|-----------------------------------------------------------------|-------------| +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | + +## **MOBILE SERVICE** + +| | | +|--------------------------------------------------------|-------------| +| Mobile services and multdestination satellite services | F.110–F.159 | +|--------------------------------------------------------|-------------| + +## **TELEMATIC SERVICES** + +| | | +|-------------------------------------------|-------------| +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | + +## **MESSAGE HANDLING SERVICES** + +| | | +|--|-------------| +| | F.400–F.499 | +|--|-------------| + +## **DIRECTORY SERVICES** + +| | | +|--|-------------| +| | F.500–F.549 | +|--|-------------| + +## **DOCUMENT COMMUNICATION** + +| | | +|--------------------------------------|-------------| +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | + +## **DATA TRANSMISSION SERVICES** + +| | | +|--|-------------| +| | F.600–F.699 | +|--|-------------| + +## **MULTIMEDIA SERVICES** + +| | | +|--|--------------------| +| | F.700–F.799 | +|--|--------------------| + +## **ISDN SERVICES** + +| | | +|--|-------------| +| | F.800–F.849 | +|--|-------------| + +## **UNIVERSAL PERSONAL TELECOMMUNICATION** + +| | | +|--|-------------| +| | F.850–F.899 | +|--|-------------| + +## **ACCESSIBILITY AND HUMAN FACTORS** + +| | | +|--|-------------| +| | F.900–F.999 | +|--|-------------| + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.746.7 + +## Metadata for an intelligent question answering service + +## Summary + +Recommendation ITU-T F.746.7 describes metadata for the intelligent question answering service (IQAS) framework specified in Recommendation ITU-T F.746.3. This Recommendation specifies metadata and service flow for different functions to support the IQAS, which provides advanced functions to generate answers for user questions in natural language. The scope of this Recommendation covers metadata for a natural language processing function, question analysis function, candidate answer generation function, answer inference/generation function, as well as an input and output function. This Recommendation also describes general information flows to describe how metadata are used in the (IQAS. + +### History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.746.7 | 2018-08-29 | 16 | 11.1002/1000/13658 | + +### Keywords + +Intelligent system, natural language processing, question answering, QA, QA metadata + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +### INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2019 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|--------------------------------------------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 3 | +| 6 Overview..... | 3 | +| 7 Functional components and information flow of the intelligent question answering service ..... | 4 | +| 8 Information for natural language processing..... | 5 | +| 9 Information for question analysis ..... | 11 | +| 10 Information for candidate answer generation ..... | 14 | +| 11 Information for answer inference/generation ..... | 16 | +| Appendix I – Example of named entity types..... | 20 | +| Bibliography..... | 25 | + + + +# Recommendation ITU-T F.746.7 + +## Metadata for an intelligent question answering service + +## 1 Scope + +This Recommendation describes metadata related to the intelligent question answering service (IQAS). The IQAS framework in [ITU-T F.746.3] already identifies some elements and attributes related to an IQAS; however, it does not define all elements needed to provide the basic features of an IQAS. This Recommendation specifies metadata for the following IQAS features as well as the general information flows to describe how metadata are used in the IQAS. + +- information for natural language processing; +- information for question analysis; +- information for candidate answer generation; +- information for answer inference/generation; +- information for input and output. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T F.746.3] Recommendation ITU-T F.746.3 (2015), *Intelligent question answering service framework*. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 co-reference resolution** [ITU-T F.746.3]: A function that detects the preceding referents of the pronouns which replace the noun phrases of the input sentences. + +**3.1.2 named entity recognition** [ITU-T F.746.3]: A function that recognizes named entities such as PLO entities which are people, locations and organizations from the sentences. The PLO can be decomposed into more detailed named entities depending on the applications. + +**3.1.3 natural language processing** [ITU-T F.746.3]: A method that analyses text in natural languages through several processes such as part-of-speech recognition, syntactic analysis and semantic analysis. + +**3.1.4 part-of-speech recognition** [ITU-T F.746.3]: A function that recognizes parts of speech (POS) in the sentences and assigns relevant POS tags considering contextual meaning of the target sentences. + +**3.1.5 semantic analysis** [ITU-T F.746.3]: A function that recognizes the semantic relations among the words around predicates that exist in the same sentence. The semantic analysis function then generates a semantic predicate argument structure (PAS). + +**3.1.6 speech** [b-ITU-T H.703]: Speech is the vocalized form of human communication. + +**3.1.7 syntactic analysis** [ITU-T F.746.3]: A function that analyses sentence structures and generates dependency relations among words based on dependency grammars. + +### **3.2 Terms defined in this Recommendation** + +This Recommendation defines the following terms: + +**3.2.1 CV\_occupation:** A named entity tag belonging to the civilization (CV) category that indicates a person's occupation. (e.g., scientist). + +**3.2.2 CV\_prize:** A named entity tag belonging to the civilization (CV) category that indicates a prize. (e.g., Nobel prize). + +**3.2.3 IsA relation:** A hierarchical relation between two words in such a way that the meaning of one word includes that of the other. + +**3.2.4 knowledge base (KB):** A collection of knowledge resources that consists of structured and unstructured data. The knowledge base is used to provide information to the various applications that are related to information provisioning such as question answering (QA) systems and search systems. + +**3.2.5 question answering (QA):** A system that provides answers in natural language to questions in natural language form by analysing the questions and all the knowledge resources that are available to the system. + +## **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|--------|----------------------------------------| +| DB | Database | +| ID | Identifier | +| IQAS | Intelligent Question Answering Service | +| KB | Knowledge Base | +| LAT | Lexical Answer Type | +| NE | Named Entity | +| NLP | Natural Language Processing | +| NLU | Natural Language Understanding | +| NNG | Noun, General | +| NNP | Noun, Proper | +| NP_OBJ | Noun Phrase Objective | +| NP_SBJ | Noun Phrase Subjective | +| PAS | Predicate Argument Structure | +| PLO | People, Location, Organization | +| POS | Part Of Speech | +| QA | Question Answering | +| SRL | Semantic Role Labelling | +| TV | Television | +| URL | Uniform Resource Locator | + +| | | +|-----|----------------------------| +| VP | Verb Phrase | +| VV | Verb | +| WSD | Word Sense Disambiguation | +| XSV | Auxiliary Suffix from Verb | + +## 5 Conventions + +None. + +## 6 Overview + +An intelligent question answering service (IQAS) is an advanced function to generate answers for user questions in natural language. Figure 1 illustrates the concept of QA system in the digital signage domain, where a user requests information about shoe stores to the QA system at the mall. + +![Diagram illustrating the concept of a QA system in the digital signage domain. A 'QA server' (represented by a group of server icons) is connected via a double-headed blue arrow to a 'Digital signage' screen. The screen displays a woman in a mall. A speech bubble from the woman says 'Go to the third floor.' To the right, a child in a shopping cart asks 'Where can I find some nice shoes?' The diagram is labeled 'F.746.7(18)_F01' at the bottom right.](367926125450c2bc3f4bdca9d59a62ba_img.jpg) + +The diagram shows a 'QA server' at the top, represented by a yellow box containing several server icons. Below it, a double-headed blue arrow points to a 'Digital signage' screen. The screen displays a woman in a mall. A speech bubble from the woman says 'Go to the third floor.' To the right of the screen, a child in a shopping cart asks 'Where can I find some nice shoes?' The diagram is labeled 'F.746.7(18)\_F01' at the bottom right. + +Diagram illustrating the concept of a QA system in the digital signage domain. A 'QA server' (represented by a group of server icons) is connected via a double-headed blue arrow to a 'Digital signage' screen. The screen displays a woman in a mall. A speech bubble from the woman says 'Go to the third floor.' To the right, a child in a shopping cart asks 'Where can I find some nice shoes?' The diagram is labeled 'F.746.7(18)\_F01' at the bottom right. + +**Figure 1 – Digital signage with question answering function: At the mall** + +Figure 2 presents an example of QA architecture. The QA system consists of several functional blocks: those for natural language processing, question analysis, candidate answer generation, answer inference and generation. + +![Figure 2: Example of a question answering architecture in accordance with [ITU-T F.746.3]. The diagram shows a flow from 'Question' to 'Question analysis' (containing 'Question understanding'), then to 'Question decomposition', which leads to 'Candidate answer generation' (containing 'Multiple information search'). Below 'Multiple information search' are icons for a globe, a document, and a network. The flow continues to 'Answer inference' (containing 'Confidence calculation') and finally to 'Answer generation' (containing 'Best answer generation'), resulting in the 'Answer'. A 'Natural language processing' block is shown at the bottom left, with an arrow pointing to 'Question decomposition'.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +``` + +graph LR + Question[Question] --> QA[Question analysis] + QA --> QD[Question decomposition] + QD --> CAG[Candidate answer search] + CAG --> AI[Answer inference] + AI --> AG[Answer generation] + AG --> Answer[Answer] + NLP[Natural language processing] --> QD + CAG --> DB[(Database icons: globe, document, network)] + +``` + +Figure 2: Example of a question answering architecture in accordance with [ITU-T F.746.3]. The diagram shows a flow from 'Question' to 'Question analysis' (containing 'Question understanding'), then to 'Question decomposition', which leads to 'Candidate answer generation' (containing 'Multiple information search'). Below 'Multiple information search' are icons for a globe, a document, and a network. The flow continues to 'Answer inference' (containing 'Confidence calculation') and finally to 'Answer generation' (containing 'Best answer generation'), resulting in the 'Answer'. A 'Natural language processing' block is shown at the bottom left, with an arrow pointing to 'Question decomposition'. + +F.746.7(18)\_F02 + +**Figure 2 – Example of a question answering architecture in accordance with [ITU-T F.746.3]** + +This Recommendation addresses metadata related to the IQAS to present details of content and service information. [ITU-T F.746.3] has specified some elements that are applicable to IQASs. + +This Recommendation selects basic elements/attributes from these specifications that are applicable to the IQAS. Names of elements/attributes are quoted as they are in the specifications, in order to keep clear the relationship between them. + +## 7 Functional components and information flow of the intelligent question answering service + +IQAS functional components are basically composed of natural language processing, question analysis, candidate answer generation, answer inference and answer generation functional blocks, as follows. + +- **Natural language processing functional block:** supports natural language processing on the QA server. +- **Question analysis functional block:** supports question analysis on the terminal. +- **Candidate answer generation functional block:** supports candidate answer generation by searching information in various databases (DBs). +- **Answer inference/generation functional block:** supports answer inference based on feature normalization and ranking of candidate answers and best answer generation on the terminal. + +See Figure 3. + +![Flowchart of functional blocks in an intelligent question answering service. The process starts with 'Question', followed by 'Natural language understanding', 'Question entailment', 'Question decomposition', and 'Question analysis'. A green shaded area encompasses these four steps. Below this, the process branches into 'KB based candidate retrieval' and 'IR-based passage retrieval', which lead to 'Answer candidates generation'. This is followed by 'Answer candidates reduction', 'Answer verification', and 'Answer confidence reasoning'. The final output is 'Answer, confidence, source'. Brackets on the left indicate that 'Answer type axiom proving' applies to 'Answer candidates reduction' and 'Answer verification', and 'Answer constraints axiom proving' applies to 'Answer verification' and 'Answer confidence reasoning'. A dashed line connects 'Question decomposition' to 'Question analysis'. A small label 'F.746.7(18)_F03' is at the bottom right.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +``` + +graph TD + Question --> NLU[Natural language understanding] + NLU --> Entailment[Question entailment] + Entailment --> Decomposition[Question decomposition] + Decomposition --> Analysis[Question analysis] + subgraph GreenShade [ ] + Decomposition + Analysis + end + Analysis --> Retrieval[KB based candidate retrieval / IR-based passage retrieval] + Retrieval --> Gen[Answer candidates generation] + Gen --> Red[Answer candidates reduction] + Red --> Ver[Answer verification] + Ver --> Reason[Answer confidence reasoning] + Reason --> Output[Answer, confidence, source] + + ATAP[Answer type axiom proving] -.-> Red + ATAP -.-> Ver + ACAP[Answer constraints axiom proving] -.-> Ver + ACAP -.-> Reason + +``` + +Flowchart of functional blocks in an intelligent question answering service. The process starts with 'Question', followed by 'Natural language understanding', 'Question entailment', 'Question decomposition', and 'Question analysis'. A green shaded area encompasses these four steps. Below this, the process branches into 'KB based candidate retrieval' and 'IR-based passage retrieval', which lead to 'Answer candidates generation'. This is followed by 'Answer candidates reduction', 'Answer verification', and 'Answer confidence reasoning'. The final output is 'Answer, confidence, source'. Brackets on the left indicate that 'Answer type axiom proving' applies to 'Answer candidates reduction' and 'Answer verification', and 'Answer constraints axiom proving' applies to 'Answer verification' and 'Answer confidence reasoning'. A dashed line connects 'Question decomposition' to 'Question analysis'. A small label 'F.746.7(18)\_F03' is at the bottom right. + +**Figure 3 – Information flow of functional blocks in an intelligent question answering service** + +## 8 Information for natural language processing + +This clause describes the metadata for natural language processing (NLP) information elements. The NLP module consists of the natural language understanding (NLU) function and the linguistic knowledge learning and extraction function. The NLU function analyses user questions as well as target documents for knowledge extraction using the semantic and syntactic analysis technology. The linguistic knowledge learning and extraction functions extract semantic relations among words and time/location information in the documents and acquire linguistic knowledge. + +The information flow of natural language processing is described in Figure 4 as sequentially connected submodules that analyse input documents to generate one best main result for each processing submodule. To prevent error propagation from this sequential processing method, a subsidiary language analyser, which consists of the same submodules as the main NLP module, generates several analysis results for the submodules. A central controller operates on the multiple NLP analysers using an algorithm with a non-transitory storage device to prevent error propagation along with an analysis result amender. When errors occur in the main analysis result, the analysis result amender acquires multiple subsidiary analysis results that correspond to the main analysis result where the error occurred. It then transmits a substitute main analysis result with the subsidiary analysis result, and re-performs a main language analysis. + +![Flowchart showing the information flow of natural language processing: POS analysis -> NE analysis -> Word sense recognition -> Chunking -> Dependency analysis -> Semantic role labelling. F.746.7(18)_F04](d4af765160d04ecef538e5066006dc77_img.jpg) + +``` + +graph LR + A[POS analysis] --> B[NE analysis] + B --> C[Word sense recognition] + C --> D[Chunking] + D --> E[Dependency analysis] + E --> F[Semantic role labelling] + +``` + +F.746.7(18)\_F04 + +Flowchart showing the information flow of natural language processing: POS analysis -> NE analysis -> Word sense recognition -> Chunking -> Dependency analysis -> Semantic role labelling. F.746.7(18)\_F04 + +**Figure 4 – Information flow of natural language processing** + +The analysis result amender performs the substitution as follows. The amender: + +- determines whether there is a contradiction between the main analysis results; +- in response to such a detection, determines whether an error in the language processing modules is causing the contradiction; +- acquires a subsidiary analysis result that is different from the main analysis result; and +- transmits the subsidiary analysis result to the language processing modules of the main language analyser. + +A set of elements/attributes for NLP information are shown in Tables 1 to 12. + +**Table 1 – Natural language processing information elements/attributes – Document** + +| Element/attribute | Description | Type | +|-------------------|---------------------------------------------------------------------------------------------------------------------------------------|---------------------| +| N_DOC | Wrapper object of the NLP result | object | +| Title | Title object of a document for NLP which contains text and a named entity (NE) | object | +| text | Title text of the document | String | +| NE | NE of the title, e.g., person, location, organization | String | +| Category | Category of the document | string | +| Category_weight | Reliability of the categorization of document for NLP between 0 and 1 | double | +| Doc_id | Identifier (ID) of the document | integer | +| DCT | Document creation time | String | +| Other_metaInfo | Other metadata information about the document that is saved as a key-value e.g.,
{ "URL" : "http://ko.wikipedia.org/wiki/Cicano" } | Map | + +**Table 2 – Natural language processing information elements/attributes – Sentence** + +| Element/attribute | Description | Type | +|-------------------|-----------------------------------------------------------------------|---------| +| Sentence | Result of the NLP which includes ID and original text | object | +| text | Title text of the document | String | +| NE | NE of the title, e.g., person, location, organization | String | +| Category | Category of the document | string | +| Category_weight | Reliability of the categorization of document for NLP between 0 and 1 | double | +| Doc_id | ID of the document | integer | +| DCT | Document creation time | String | + + + +**Table 4 – Natural language processing information elements/attributes – Named entity analysis** + +| Element/attribute | Description | Type | +|-------------------|---------------------------------------------------------------------|---------| +| NE | Result of NE analysis | object | +| id | ID of a word (starting from 0 in a sentence) | integer | +| text | Text of a word | string | +| type | NE type, e.g., river, person, organization | string | +| begin | ID of the first POS tag in word | integer | +| end | ID of the last POS tag in a word | integer | +| weight | Reliability of word sense disambiguation (WSD) analysis from 0 to 1 | double | +| Common_noun | Specify if it is common noun (1) or proper noun (0) | 0 or 1 | +| amended | Indicates the result is the amended one or not | boolean | + +See Figure 6. + +An example of an NE analysis: + +``` +{"NE" : [ +{"id" : 0, "text" : " JeongHyun Park ", "type" : "PS_NAME", "begin" : 0, "end" : 0, +"weight" : 0.752954, "common_noun" : 0, "amended" : "TRUE" }, +{"id" : 1, "text" : "president", "type" : "CV_POSITION", "begin" : 1, "end" : 1, "weight" +: 0.528416, "common_noun" : 0, "amended" : "FALSE" }, +{"id" : 2, "text" : "minister", "type" : "CV_POSITION", "begin" : 3, "end" : 3, "weight" +: 0.431414, "common_noun" : 0, "amended" : "TRUE" } +]} +``` + +(President Park appoints Prime Minister.) + +![Flowchart showing information flow for named entity analysis: Input (morp) -> NE analysis -> NE -> Word sense recognition. Below the diagram is the text F.746.7(18)_F06.](1b5a812c8aa20fd5cba28e97001d32de_img.jpg) + +``` + +graph LR + Input(( )) -- morp --> NE[NE analysis] + NE -- NE --> WSD[Word sense recognition] + +``` + +F.746.7(18)\_F06 + +Flowchart showing information flow for named entity analysis: Input (morp) -> NE analysis -> NE -> Word sense recognition. Below the diagram is the text F.746.7(18)\_F06. + +**Figure 6 – Information flow for a named entity analysis** + +**Table 5 – Natural language processing information elements/attributes – Word sense recognition** + +| Element/attribute | Description | Type | +|-------------------|----------------------------------------------------------|---------| +| WSD | Result of word sense disambiguation (recognition) | object | +| id | ID of WSD target word | integer | +| text | Target of WSD | String | +| type | POS tag of the text, e.g., Desk(word): NOUN(POS tag) | string | +| scode | Sense number in a predefined list or standard dictionary | integer | +| position | Byte position in a sentence | integer | +| weight | Reliability of WSD analysis from 0 to 1 | double | +| begin | ID of the first POS tag in a target word | string | +| end | ID of the last POS tag in a target word | string | +| amended | Indicates the result is the amended one or not | boolean | + +See Figure 7. + +An example of WSD result: + +``` +{"WSD" : [ + {"id" : 0, "text" : " JeongHyun Park ", "type" : "NNP", "scode" : "00", "weight" : 1, "position" : 0, "begin" : 0, "end" : 0, "amended" : "TRUE" }, + {"id" : 1, "text" : "president", "type" : "NNG", "scode" : "00", "weight" : 1, "position" : 10, "begin" : 1, "end" : 1, "amended" : "TRUE" }, + {"id" : 2, "text" : "i", "type" : "JKS", "scode" : "00", "weight" : 1, "position" : 19, "begin" : 2, "end" : 2, "amended" : "FALSE" }, + {"id" : 3, "text" : "minister", "type" : "NNG", "scode" : "01", "weight" : 1, "position" : 23, "begin" : 3, "end" : 3, "amended" : "TRUE" }, + {"id" : 4, "text" : "lul", "type" : "JKO", "scode" : "00", "weight" : 1, "position" : 29, "begin" : 4, "end" : 4, "amended" : "FALSE" }, + {"id" : 5, "text" : "appoint", "type" : "VV", "scode" : "03", "weight" : 1, "position" : 33, "begin" : 5, "end" : 6, "amended" : "TRUE" }, + {"id" : 6, "text" : "n-da", "type" : "EF", "scode" : "00", "weight" : 1, "position" : 39, "begin" : 7, "end" : 7, "amended" : "FALSE" }, + {"id" : 7, "text" : ".", "type" : "SF", "scode" : "00", "weight" : 1, "position" : 45, "begin" : 8, "end" : 8, "amended" : "TRUE" } +]} +(President Park appoints Prime Minister.) +``` + +![Flowchart showing information flow for word sense recognition: NE -> Word sense recognition -> WSD -> Chunking. Below the diagram is the code F.746.7(18)_F07.](724c7777b608e53be38b12b6fb3c43bc_img.jpg) + +``` +graph LR + NE(( )) -- NE --> WSR[Word sense recognition] + WSR -- WSD --> CH[Chunking] + style NE fill:none,stroke:none + style WSR fill:#d9e1f2,stroke:#333,stroke-width:1px + style CH fill:#d9e1f2,stroke:#333,stroke-width:1px +``` + +F.746.7(18)\_F07 + +Flowchart showing information flow for word sense recognition: NE -> Word sense recognition -> WSD -> Chunking. Below the diagram is the code F.746.7(18)\_F07. + +Figure 7 – Information flow for word sense recognition + +Table 6 – Natural language processing information elements/attributes – Chunking + +| Element/attribute | Description | Type | +|-------------------|-----------------------------------------------------|---------| +| chunk | Result of chunking | object | +| id | ID of chunking unit (starting from 0 in a sentence) | integer | +| text | Text of chunking result (restored from POS result) | string | +| type | Chunking type, e.g., river, person, organization | string | +| begin | ID of the first POS tag in a chunk | integer | +| end | ID of the last POS tag in a chunk | integer | +| weight | Reliability of POS analysis from 0 to 1 | double | +| amended | Indicates whether the result is the amended one | boolean | + +See Figure 8. + +An example of chunking: + +``` +{"chunk" : [ + {"id" : 0, "text" : " President JeongHyun Park ", "type" : "NP", "begin" : 0, "end" : 2, "weight" : 1, "amended" : "TRUE"}, + {"id" : 1, "text" : "minister", "type" : "NP", "begin" : 3, "end" : 4, "weight" : 1, "amended" : "FALSE" }, + {"id" : 2, "text" : "appoint", "type" : "VP", "begin" : 5, "end" : 8, "weight" : 1, "amended" : "TRUE"} +]} +(President Park appoints Prime Minister.) +``` + +![Flowchart showing information flow for chunking process: WSD -> Chunking -> chunk -> Dependency analysis. F.746.7(18)_F08](fa859e4e468bfb2710a94527f2c504af_img.jpg) + +``` + +graph LR + WSD((WSD)) --> Chunking[Chunking] + Chunking -- chunk --> DA[Dependency analysis] + +``` + +F.746.7(18)\_F08 + +Flowchart showing information flow for chunking process: WSD -> Chunking -> chunk -> Dependency analysis. F.746.7(18)\_F08 + +**Figure 8 – Information flow for chunking process** + +**Table 7 – Natural language processing information elements/attributes – Dependency analysis** + +| Element/attribute | Description | Type | +|-------------------|--------------------------------------------------------------------------------------------|---------| +| dependency | Result of dependency analysis | object | +| id | ID of a word (starting from 0 in a sentence) | integer | +| text | Text of a word | string | +| head | ID of a parent word in a dependency graph | string | +| label | Dependency relation, e.g., noun phrase objective (NP_OBJ), noun phrase subjective (NP_SBJ) | string | +| mod | ID of a child word in a dependency graph | string | +| weight | Reliability of dependency analysis | double | +| amended | Indicates the result is the amended one or not | boolean | + +See Figure 9. + +An example of dependency analysis: + +``` + +{"dependency" : [ + {"id" : 0, "text" : " JeongHyun Park ", "head" : 1, "label" : "NP", "mod" : [], "weight" : 0.7696, "amended" : "TRUE"}, + {"id" : 1, "text" : "president", "head" : 3, "label" : "NP_SBJ", "mod" : [0], "weight" : 0.561622, "amended" : "TRUE"}, + {"id" : 2, "text" : "minister", "head" : 3, "label" : "NP_OBJ", "mod" : [], "weight" : 0.486835, "amended" : "TRUE"}, + {"id" : 3, "text" : "appoint", "head" : -1, "label" : "VP", "mod" : [1, 2], "weight" : 0.163655, "amended" : "FALSE"} +] +(President Park appoints Prime Minister.) + +``` + +![Flowchart showing information flow for dependency analysis: chunk -> Dependency analysis -> dependency -> Semantic role labelling. F.746.7(18)_F09](cb4cfa42ce34febde7bdb882f3fc3094_img.jpg) + +``` + +graph LR + chunk((chunk)) --> DA[Dependency analysis] + DA -- dependency --> SRL[Semantic role labelling] + +``` + +F.746.7(18)\_F09 + +Flowchart showing information flow for dependency analysis: chunk -> Dependency analysis -> dependency -> Semantic role labelling. F.746.7(18)\_F09 + +**Figure 9 – Information flow for dependency analysis** + +**Table 8 – Natural language processing information elements/attributes – Semantic role labelling** + +| Element/attribute | Description | Type | +|-------------------|------------------------------------------------|---------| +| SRL | Result of semantic role labelling | object | +| Verb | Target verb which is a predicate of a sentence | string | +| sense | Sense number of the target verb | Integer | +| Word_id | ID of the verb word | integer | +| weight | Reliability of SRL result | double | +| argument | Semantic argument information of a verb | object | + +**Table 8 – Natural language processing information elements/attributes – Semantic role labelling** + +| Element/attribute | Description | Type | +|-------------------|------------------------------------------------|---------| +| type | Argument type | string | +| text | Text of a word in an argument | string | +| Word_id | ID of a word in an argument | integer | +| weight | Reliability of argument analysis | double | +| amended | Indicates the result is the amended one or not | boolean | + +See Figure 10. + +An example of semantic role labelling: + +``` +{ "SRL":[ + { "verb":"appoint", "sense":1, "word_id":3, "weight":0.154974, "argument":[ + { "type":"ARG0", "word_id":1, "text":"president", "weight":0.170862}, + { "type":"ARG1", "word_id":2, "text":"minister", "weight":0.139087}, + { "amended":"TRUE"} ] + } +] } +(President Park appoints Prime Minister.) +``` + +![Flowchart showing information flow for semantic role labelling. A box labeled 'Dependency' points to a box labeled 'Semantic role labelling', which in turn points to a box labeled 'Question analysis'. Below the 'Question analysis' box is the text 'F.746.7(18)_F10'.](33a8f3f01dfa8bce75d23017855a13c5_img.jpg) + +``` + +graph LR + Dependency --> SRL[Semantic role labelling] + SRL --> QA[Question analysis] + QA --- F746_7_18_F10[F.746.7(18)_F10] + +``` + +Flowchart showing information flow for semantic role labelling. A box labeled 'Dependency' points to a box labeled 'Semantic role labelling', which in turn points to a box labeled 'Question analysis'. Below the 'Question analysis' box is the text 'F.746.7(18)\_F10'. + +**Figure 10 – Information flow for semantic role labelling** + +## 9 Information for question analysis + +This clause describes metadata for user question analysis information. The question analysis module in Figure 11 analyses questions that are input in a natural language by users, understands their intention, and recognizes various pieces of information in the answers that should be presented as the output of the IQAS. In the natural language question answering system, a query axiom is generated from an input question through a textual entailment recognition process, in which additional questions are extracted from the original question based on its meaning. For the question analysis, the following metadata elements are used. A set of elements/attributes for user question analysis information is shown in Table 9 for question information and Table 10 for answer information. See Figure 12. + +![Flowchart of submodules for question analysis, showing Question decomposition and Question analysis stages.](76b0cd79baaedd942af4dc42f2e764b8_img.jpg) + +The diagram illustrates the submodules for question analysis, divided into two main stages: **Question decomposition** and **Question analysis**. + +**Question decomposition** (top stage): + +- Question** → **Question entailment** (dashed line to **Complex questions**) +- Question entailment** → **Sentence based question split** +- Sentence based question split** → **Sub-question type classification** +- Sub-question type classification** → **Sub-question relation recognition** +- Sub-question relation recognition** → **Sub-questions** +- Sub-questions** → **QIF based question split** +- QIF based question split** → **Yes** (back to **Sub-question type classification**) +- QIF based question split** → **No** → **Question relation type classification** → **Axioms of individual facts** +- QIF based question split** also receives input from **QIF generation** (bottom stage) with the set: $\{QD, QC, QF, AT, QT, AC, QIF\}$ . + +**Question analysis** (bottom stage): + +- Sub-questions** → **QDomain classification** +- QDomain classification** → **QClass classification** +- QClass classification** includes: $QC^{AForm}$ , $QC^{Syntactic}$ , $QC^{Semantic}$ +- QClass classification** → **QFocus detection** +- QFocus detection** → **AType recognition** +- AType recognition** includes: *LAT detection*, *SAT classification* +- AType recognition** → **QTopic detection** +- QTopic detection** → **AConstraint recognition** +- AConstraint recognition** includes: *FRAMEsyntactic*, *Comparison*, *Definition*, *Negation*, *Apposition*, *Time*, *Language*, *Location* +- AConstraint recognition** → **QIF generation** + +Flowchart of submodules for question analysis, showing Question decomposition and Question analysis stages. + +F.746.7(18)\_F11 + +Figure 11 – Submodules for question analysis + +Table 9 – Metadata for question analysis information – Question + +| Element/attribute | Description | Type | +|-------------------|------------------------------------------------------------------------------------------------------------------------|--------------| +| Q_tagged | Question tagged with question focus and LAT (lexical answer type) | string | +| Q_class | Object for question classification | object | +| QC_atype | Question classification according to the way the answer is presented, e.g., simple answer vs. complex answer | string | +| QC_semantic | Question classification based on the meaning of the question, e.g., request for attributes vs. request for terminology | string array | +| QC_syntactic | Question classification based on the structure of the question, e.g., fill in the blank vs. statement type | string array | +| Q_domain | Domain of the question, e.g., science, health, history ... | string array | +| Q_level | Difficulty of the question | string | +| Q_complexity | Complexity of the question sentence, e.g., single sentence, complex sentence structure, multiple sentences ... | string | +| Q_focus | Array of the question focus, e.g., what, who, what policy... | string array | +| Q_SAT | Array of semantic answer type in the question based on NE classification, e.g., Person_actor, Location_river... | string array | + +**Table 9 – Metadata for question analysis information – Question** + +| Element/attribute | Description | Type | +|-------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------| +| Q_LAT | Array of lexical answer type in the question, e.g., nationality, chemical, person ... | string array | +| Q_topic | Array of question topics. Question topic is the object or event that the question is about, e.g., Q_topic is King Lear in "Who is the author of King Lear?" | string array | +| Q_relttype | Question relation type | string | +| Q_decomp | Object array of sub-questions | object array | +| SubQ_id | ID of sub-question. Number is assigned sequentially from 1 | integer | +| SubQ_string | Content of sub-question | string | +| SubQ_type | Question type of the sub-question | string | +| SubQ_complexity | Sentence complexity of the sub-question | string | +| Q_quotation | Quotation phrase for "filling in the blank" type question in a quiz | string | +| Q_constraint | Answer constraint information object | object | +| Q_SF | Syntactic frame object for answer constraint | object | +| Q_NEG | Negation question type, e.g., Which day does the shop not open? | string | +| Q_LAN | Language constraint information of answer, e.g., Chinese character in the question | string | +| Q_APP | Question apposition information for answer constraint. It provides the same meaning of a word which constrains an answer, e.g., What is "snow" in Portuguese? (In this question, snow is marked as Q_APP) | string | +| Q_DEF | Definition information for answer constraint | string | +| Q_COM_MOD | Comparison by modifier for answer constraint | object | +| Q_COM_ADVERB | Adverbial comparison object for answer constraint | object | +| Q_TE | Expressive time constraint information | string | +| Q_TI | Implied time constraint information | string | +| Q_SE | Expressive location constraint information | string | +| Q_SI | Implied location constraint information | string | + +**Table 10 – Metadata for question analysis information - Answer** + +| Element/attribute | Description | Type | +|-------------------|------------------------------------------------------------------------------------------------------------|--------------| +| A_ans | Answer string | string | +| A_synonym | String array of synonym answers (of similar meaning) | string array | +| A_type | Classified answer meaning which corresponds to NE type, e.g., person, location, animal, date, organization | string | +| Passage | Objects to provide answer evidence, e.g., sentences that provide answer evidence | object array | +| A_domain | Answer domain, e.g., literature, science, health | string array | +| A_level | Difficulty level of the answer inference, e.g., very difficult, difficult, not difficult | string array | +| AP_sent | Sentences that contain the answer | string | +| AP_title | Title of a document that contains the answer | string | +| AP_origin | Document title of the answer source, e.g., wiki | string | +| AP_URL | Uniform resource locator (URL) of the answer source | URL | + +![Flowchart showing information flow for question analysis: NLP results lead to Question analysis, which produces Q analysis result, which leads to Candidate answer generation. F.746.7(18)_F12](5445597cceefaca1ac89e710fe339325_img.jpg) + +``` + +graph LR + A[NLP results] --> B[Question analysis] + B --> C[Q analysis result] + C --> D[Candidate answer generation] + +``` + +F.746.7(18)\_F12 + +Flowchart showing information flow for question analysis: NLP results lead to Question analysis, which produces Q analysis result, which leads to Candidate answer generation. F.746.7(18)\_F12 + +**Figure 12 – Information flow for question analysis** + +## 10 Information for candidate answer generation + +This clause describes metadata for the candidate answer generation module. The candidate answer generation module performs index and search functions on document collections and generates candidate answers from the input query using search results and various databases, such as a structured/unstructured KB. + +A set of elements/attributes for candidate answer generation module are shown in Table 11. + +**Table 11 – Metadata for candidate answer generation** + +| Element/attribute | Description | Type | +|-------------------|-------------------------------------------|---------| +| IR_result | Result of information search | object | +| docid | Document ID | string | +| domain | Domain of the candidate answer resource | string | +| cpname | Type of search engine | string | +| doc_title | Document title | string | +| description | Contents of the search result sentence | string | +| weight | Search weight | double | +| ranking | Ranking of the search results | integer | +| qType | Search question | string | +| Candidates | Result of the candidate answer generation | object | +| ranking | Ranking of the candidate answer | integer | +| answer | Candidate answer | string | + +**Table 11 – Metadata for candidate answer generation** + +| Element/attribute | Description | Type | +|-------------------|-------------------------------------------|---------| +| type | Type of the candidate answer | string | +| NEType | NE type of the candidate answer | string | +| resource | Information on the search result sentence | string | +| cpname | Type of search engine | string | +| source | Search location | string | +| docID | Document ID | string | +| sentID | Sentence ID | string | +| IRranking | Ranking of the search | integer | +| IRsource | Search resource | string | +| qType | Search question | string | + +See Figure 13. + +An example of candidate answers: + +``` +{"IR_result": [ + {"docid":"0034765000000000", "domain":"wiki", "cpname":"wiki_definition", + "page_struct":"Tibet", "description":" Tibet Tibet (, ) is located in central Asia and is + the traditional homeland of the Tibetan people. Tibet is the highest region on Earth with + an average elevation of 4 900 m. Thus it is called “Roof of the world.” The highest + elevation in Tibet is Mount Everest, Earth's highest mountain, rising 8 848 m above sea + level. ", "weight":91.257285, "ranking":1, "qType":"original question"}, + {"docid":"0534717000000000", "domain":"wiki", "cpname":"wiki_definition", + "page_struct":"Mountain Mitchell", "description":" Mount Mitchell Mount Mitchell is the + highest peak of the Appalachian Mountains and the highest peak in mainland eastern North + America. It is located near Burnsville in Yancey County, North Carolina, in the Black + Mountain subrange of the Appalachians, and about 19 miles (31 km) northeast of Asheville. + It is protected by Mount Mitchell State Park and surrounded by the Pisgah National + Forest. Mount Mitchell's elevation is 6 684 feet (2 037 m) above sea level.", + "weight":87.192415, "ranking":2, "qType":" original question"}] + +{"Candidates": [ + {"ranking":1, "answer":"Tibet", "type":"NE", "NEType":"LCP_COUNTRY", + "resource": [ + {"cpname":"wiki_definition", "source":"[definition]Content", + "docID":"0034765000000000", "sentID":0, "qType":"original question", "IRranking":1, + "IRsource":"wiki_definition"}, + {"cpname":"wiki_definition", "source":"[definition]Content", + "docID":"0034765000000000", "sentID":0, "qType":" original question ", "IRranking":1, + "IRsource":"wiki_definition"} + ], + {"ranking":2, "answer":"Mount Mitchell", "type":"NE", "NEType":"LCG_MOUNTAIN", + "resource": [ + {"cpname":"wiki_definition", "source":"[definition]Title", + "docID":"0534717000000000", "sentID":0, "qType":" original question ", "IRranking":2, + "IRsource":"wiki_definition"}, + {"cpname":"wiki_definition", "source":"[definition]Content", + "docID":"0534717000000000", "sentID":0, "qType":" original question ", "IRranking":2, + "IRsource":"wiki_definition"}, + {"cpname":"wiki_passage", "source":"[passage]Content", + "docID":"0082641000000000", "sentID":5, "qType":" original question ", "IRranking":5, + "IRsource":"wiki_passage"} + ], +}, +``` + +``` + +{"ranking":3, "answer":"Kyonggi do", "type":"NE", "NEType":"LCP_PROVINCE", +"resource": +[ + {"cpname":"wiki_definition", "source":"[definition]Content", +"docID":"066405400000000", "sentID":0, "qType":" original question", "IRranking":3, +"IRsource":"wiki_definition"}, + {"cpname":"wiki_definition", "source":"[definition]Content", +"docID":"066405400000000", "sentID":0, "qType":" original question", "IRranking":3, +"IRsource":"wiki_definition"} +] +] +} + +``` + +![Flowchart showing information flow for candidate answer generation. It consists of three boxes: 'Q analysis results' pointing to 'Candidate answer generation', which points to 'Answer inference/generation'. The label 'Candidate answer, reliabilities' is above the arrow between the second and third boxes. A small code 'F.746.7(18)_F13' is at the bottom right.](08a978a124d3ed6cf1a3d0cfd89418d0_img.jpg) + +``` + +graph LR + A[Q analysis results] --> B[Candidate answer generation] + B -- "Candidate answer, reliabilities" --> C[Answer inference/generation] + +``` + +F.746.7(18)\_F13 + +Flowchart showing information flow for candidate answer generation. It consists of three boxes: 'Q analysis results' pointing to 'Candidate answer generation', which points to 'Answer inference/generation'. The label 'Candidate answer, reliabilities' is above the arrow between the second and third boxes. A small code 'F.746.7(18)\_F13' is at the bottom right. + +**Figure 13 – Information flow for candidate answer generation** + +## 11 Information for answer inference/generation + +The function of the answer inference and generation module is to decide and generate the best answer by measuring reliabilities of the candidate answers using the query axiom, the filtered candidate answers, the reasoned candidate answers as features to determine ranks of the candidate answers, based on the calculated reliability. The candidate answers are filtered and reasoned out based on a similarity between the query axiom and the candidate answers and by using an inductive, deductive or an abductive reasoning. + +The inference and generation module compares a threshold value with a reliability ratio of a best candidate answer to the second best candidate answer, readjusting the determined ranks according to a result of the comparison, and detecting the best candidate answer, determined through the readjustment, as a final answer of the QA service. + +A set of elements/attributes for answer inference/generation module are shown in Table 12. + +**Table 12 – Metadata for answer inference/generation** + +| Element/attribute | Description | Type | +|-------------------|-------------------------------------------------------|---------| +| AnsUnit_TotalCnt | Total number of the final candidate answers | integer | +| AnsUnit | Information on final candidate answers | object | +| rank | Ranking of the final candidate answers | integer | +| answer | Final candidate answer | string | +| kb_weight | Weight of KB query | double | +| ir_weight | Weight of search (information retrieval) | double | +| Tot_weight | Weight total | double | +| CI_feature | Type and constraint inference feature | object | +| type | Type of the final candidate answer | string | +| NEType | NE type of the final candidate answer | string | +| CIweight | Reliability for constraint on final candidate answers | double | +| TyCor_vec | Type and constraint inference feature | vector | +| | 0: type reliability | double | +| | 1: wordnet feature | double | + +**Table 12 – Metadata for answer inference/generation** + +| Element/attribute | Description | Type | +|-------------------|---------------------------------------------------|---------| +| | 2: word distance feature | double | +| | 3: semantic network feature | double | +| | 4: word sense network feature | double | +| | 5: Wikipedia category feature | double | +| | 6: IsA feature | double | +| | 7: class/instance relation feature | double | +| | 8: location similarity feature | double | +| | 9: time similarity feature | double | +| | 10: linguistic constraint feature | double | +| | 11: cultural asset constraint feature | double | +| | 12: proverb constraint feature | double | +| | 13: number constraint feature | double | +| | 14: work constraint feature | double | +| | 15: entity frequency feature | double | +| | 16: quotation constraint feature | double | +| | 17: integrated answer constraint feature | double | +| AnsSent | Information on evidence search | object | +| AnsSent_totalCnt | Number of evidence search | integer | +| ASent | Sentence information on evidence search | object | +| docID | Document ID | string | +| sentID | Sentence ID | string | +| DIRweight | Weight of the evidence search | double | +| CD_vec | Evidence inference information | vector | +| source | Location of evidence search | string | +| cpname | Evidence search engine | string | +| domain | Kind of the resource | string | +| qType | Question for evidence search | string | +| IRranking | Ranking of evidence search | integer | +| IRsource | Source of evidence search | string | +| sent | Evidence sentence | string | +| CD_feature | Information on evidence inference | vector | +| | 1: integrated reliability | double | +| | 2: word similarity feature | double | +| | 3: expanded word similarity feature | double | +| | 4: word sense similarity feature | double | +| | 5: location & time similarity feature | double | +| | 6: word layout similarity feature | double | +| | 7: word order similarity feature | double | +| | 8: expanded sentence structure similarity feature | double | + +**Table 12 – Metadata for answer inference/generation** + +| Element/attribute | Description | Type | +|-------------------|--------------------------------------------------|--------| +| | 9: expanded semantic relation similarity feature | double | +| | 10: quotation similarity feature | double | +| | 11: semantic frame similarity feature | double | +| | 12: definition/negation similarity feature | double | +| Ans_Feature | Information on reliability feature | object | +| TyCor_score | Combined type feature | double | +| Ln_score | Language feature | double | +| SEM_score | Semantic feature | double | +| CONS_score | Constraint feature | double | +| IR_score | Search feature | double | +| IR_score2 | Evidence search feature | double | +| KB_score | KBQ feature | double | +| confidence | Reliability of final answer | double | +| src_ENGINE | Kind of Search (Search or Evidence Search) | string | + +See Figure 14. + +An example of final answers: + +``` +{"AnsUnit_TotalCnt": 31, + "AnsUnit": [ + {"rank":1, "answer":"John Hancock Center", "kb_weight":0.0000, + "ir_weight":0.9040, "tot_weight":0.4976, + "CI_feature": { + "type":"NE", "NEType":"OGG_ECONOMY", "CIweight": 0.0800, "TyCor_vec": + [0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.4200, 0.0000, 0.0000, + 0.0000, 0.0000, 0.0000, 0.0000, 0.2500, 0.0000, 0.2500] + }, + "AnsSent": { + "AnsSent_TotalCnt":2, + "ASent":[ + {"docID":"1262691000000000", "sentID":9, "DIRweight":16.1910, + "CD_vec":[0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, + 0.0000, 0.0000, 0.0000], "source":"[passage]Title", + "cpname":"doosan_passage", "domain":"","qType":" org", "IRRanking":1, + "IRsource":"doosan_passage", "sent":" The 44th-floor sky lobby of John Hancock Center + features America's highest indoor swimming pool. "}, + {"docID":"0963866000000000", "sentID":10, "DIRweight":17.5910, + "CD_vec":[0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, + 0.0000, 0.0000, 0.0000], "source":"[passage]Title", + "cpname":"naver_all_passage", "domain":"","qType":" org", "IRRanking":1, + "IRsource":"naver_all_passage", "sent":" In the 44th-floor of John Hancock Center is + located America's highest indoor swimming pool."}, + {"docID":"0963866000000000", "sentID":10, "DIRweight":86.2560, + "CD_vec":[0.2570, 1.0000, 0.0000, 0.0400, 0.0300, 0.5000, 1.0000, 0.5190, 0.0000, 0.0000, + 0.0000, 0.0000, 0.0000], "source":"evidence_new", + "cpname":"naver_all_passage", "domain":"","qType":"org", "IRRanking":1, "IRsource":"Just + go Sightseeing Guide", "sent":" In the 44th-floor of John Hancock Center there is also + the America's highest indoor swimming pool. "} + ] + } + ], + "CD_feature":[0.5288, 0.5010, 0.0000, 0.8000, 1.0000, 1.0000, 0.2857, + 0.8522, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000], + "Ans_Feature": { +``` + +``` + +"TyCor_score":0.0000, "Ln_score":0.0000, "SEM_score":0.0800, +"CONS_score":0.0920, "IR_score":0.9040, "IR_score2":0.9466, "KB_score":0.0000, +"confidence":0.4976, +"src_ENGINE":"", "evidence_str":"" +}}]} + +``` + +![Diagram showing information flow for answer inference/generation. An arrow labeled 'Candidate answer, reliabilities' points to a box labeled 'Answer inference/generation', which then points to an arrow labeled 'Best answer'.](a74294f34a0c736b7ee0f5f0cdca7e28_img.jpg) + +``` + +graph LR + A(( )) -- "Candidate answer, +reliabilities" --> B[Answer +inference/ +generation] + B -- "Best answer" --> C(( )) + +``` + +F.746.7(18)\_F14 + +Diagram showing information flow for answer inference/generation. An arrow labeled 'Candidate answer, reliabilities' points to a box labeled 'Answer inference/generation', which then points to an arrow labeled 'Best answer'. + +**Figure 14 – Information flow for answer inference/generation** + +## Appendix I + +### Example of named entity types + +(This appendix does not form an integral part of this Recommendation.) + +### Named entity types + +The NE types used for a NE recognizer are presented in Table I.1. At the top level, the NE tag set is composed of 15 NE types: person (PS), academic field (FD), theory (TR), artificial object (AF), organization (OGG), location (LC), culture/civilization (CV), date (DT), time (TI), quantity (QT), event (EV), animal (AM), plant (PT), material (MT) and terminology (TM). The sub-level NE types are total 146. NE types are important information and so are used in different modules in a QA system. NE types are changed and easily adaptable depending on the purpose of the NE recognizer and various applications. + +**Table I.1 – Named entity types** + +| Named entity subtypes | Description | +|-----------------------|-------------------------------------------------------| +| PS_NAME | – name of person | +| LC_OTHERS | – other location | +| LCP_COUNTRY | – country name | +| LCP_PROVINCE | – area, county, state name | +| LCP_COUNTY | – town, street name | +| LCP_CITY | – city name | +| LCP_CAPITALCITY | – capital name | +| LCG_RIVER | – river, pond, lake name | +| LCG_OCEAN | – ocean, see name | +| LCG_BAY | – peninsula, bay | +| LCG_MOUNTAIN | – mountain, hill | +| LCG_ISLAND | – island, archipelago name | +| LCG_CONTINENT | – continent name | +| LC_TOUR | – tour attractions | +| LC_SPACE | – space name, celestial bodies | +| OG_OTHERS | – other organization | +| OGG_ECONOMY | – organization related with economy | +| OGG_EDUCATION | – educational organization and groups | +| OGG_MILITARY | – military related organization and groups | +| OGG_MEDIA | – media organization and companies | +| OGG_SPORTS | – sports organization and groups | +| OGG_ART | – art related organization and groups | +| OGG_MEDICINE | – medical organization | +| OGG_RELIGION | – religion organization/association/group | +| OGG_SCIENCE | – organization/association/group related with science | +| OGG_LIBRARY | – library related organization/association/group | +| OGG_LAW | – organization/association/group related with laws | + +**Table I.1 – Named entity types** + +| Named entity subtypes | Description | +|------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| OGG_POLITICS | – government, public organization, political organization/association/group | +| OGG_FOOD | – Food company and organization/association/group | +| OGG_HOTEL | – organization/association/group related with hotel accommodation | +| AF_CULTURAL_ASSET | – Cultural assets such as building/books/art pieces | +| AF_BUILDING | – buildings, apartment, bridge, light house, fountain, playground | +| AF_MUSICAL_INSTRUMENT | – name of a musical instrument | +| AF_ROAD | – road name, railroad name | +| AF_WEAPON | – name of weapons | +| AF_TRANSPORT | – transportation/cars/ship model and types, rides | +| AF_WORKS | – art works/other works | +| AFW_DOCUMENT | – books
– maps/books related with geology
– medical books
– religion books/bibles
– philosophy related books
– literature name such as poems/novels/play
– history books
– other books | +| AFW_PERFORMANCE | – dance name, dance works, dance types
– play, performance, Drama, opera | +| AFW_VIDEO | – movie name
– television (TV) programme name | +| AFW_ART_CRAFT | – art work, painting name | +| AFW_MUSIC | – music work name | +| AF_WARES | – product name | +| DT_OTHERS | – other date types | +| DT_DURATION | – period/duration | +| DT_DAY | – date/subdivisions of the seasons | +| DT_MONTH | – month | +| DT_YEAR | – year | +| DT_SEASON | – season | +| DT_GEOAGE | – geological period | +| DT_DYNASTY | – dynasty | +| TI_OTHERS | – other time related terms | +| TI_DURATION | – duration time | +| TI_HOUR | – hour | +| TI_MINUTE | – minute | +| TI_SECOND | – second | +| CV_NAME | – culture/civilization name | + +**Table I.1 – Named entity types** + +| Named entity subtypes | Description | +|------------------------------|---------------------------------------| +| CV_TRIBE | – name of nationality/tribe/race | +| CV_SPORTS | – Name of sports/reports/leisure | +| CV_SPORTS_INST | – sports instruments/tools | +| CV_POLICY | – name of policy/system | +| CV_TAX | – name of tax | +| CV_FUNDS | – name of pension, funds, capital | +| CV_LANGUAGE | – name of a language | +| CV_BUILDING_TYPE | – name of architectural style | +| CV_FOOD | – food name/ food ingredients | +| CV_DRINK | – name of drinks | +| CV_CLOTHING | – name of clothes, fabrics | +| CV_POSITION | – position/title/name sports position | +| CV_RELATION | – relation names among people | +| CV_OCCUPATION | – name of occupation | +| CV_CURRENCY | – name of currency | +| CV_PRIZE | – prize and medals | +| CV_LAW | – name of law | +| CV_FOOD_STYLE | – type of food | +| AM_OTHERS | – other animal names | +| AM_INSECT | – insects | +| AM_BIRD | – birds | +| AM_FISH | – fish | +| AM_MAMMALIA | – mammals | +| AM_AMPHIBIA | – amphibian | +| AM_REPTILIA | – reptilian | +| AM_TYPE | – animal types | +| AM_PART | – part of an animal (body part name) | +| PT_OTHERS | – name of other plants | +| PT_FRUIT | – name of fruit (edible plant fruit) | +| PT_FLOWER | – name of flower | +| PT_TREE | – name of a tree | +| PT_GRASS | – name of a grass | +| PT_TYPE | – plant type | +| PT_PART | – name for a part of a plant | +| QT_OTHERS | – other quantity | +| QT_AGE | – age | +| QT_SIZE | – size/width | +| QT_LENGTH | – distance, length, height | +| QT_COUNT | – count/frequency | + +**Table I.1 – Named entity types** + +| Named entity subtypes | Description | +|------------------------------|------------------------------------------------------------| +| QT_MAN_COUNT | – number of people | +| QT_WEIGHT | – weight | +| QT_PERCENTAGE | – percentage, rate, ratio, strength | +| QT_SPEED | – speed | +| QT_TEMPERATURE | – temperature | +| QT_VOLUME | – volume | +| QT_ORDER | – order, order related expressions | +| QT_PRICE | – price | +| QT_PHONE | – phone number | +| QT_SPORTS | – quantity related with sports | +| QT_CHANNEL | – TV/radio channel number | +| QT_ALBUM | – quantity related with album | +| QT_ZIPCODE | – postal code | +| FD_OTHERS | – other field of study | +| FD_SCIENCE | – field of study related with science | +| FD_SOCIAL_SCIENCE | – field of study and school related with social science | +| FD_MEDICINE | – field of study and school related with medicine | +| FD_ART | – field of study and school related with art | +| FD_PHILOSOPHY | – field of study and school related with philosophy | +| TR_OTHERS | – other theory/axiom/principals | +| TR_SCIENCE | – theory/method/principles/idea/study related with science | +| TR_SOCIAL_SCIENCE | – social science theory/method/principles/idea, politics | +| TR_ART | – art theory/method/principles/idea | +| TR_PHILOSOPHY | – philosophical theory | +| TR_MEDICINE | – medical treatments | +| EV_OTHERS | – other events | +| EV_ACTIVITY | – social movement and declaration | +| EV_WAR_REVOLUTION | – war/revolution | +| EV_SPORTS | – event related to sports/leisure | +| EV_FESTIVAL | – festival name | +| MT_ELEMENT | – element name | +| MT_METAL | – metal material | +| MT_ROCK | – name of the rocks | +| MT_CHEMICAL | – chemical material | +| TM_COLOR | – colour | +| TM_DIRECTION | – direction | +| TM_CLIMATE | – climate area name | +| TM_SHAPE | – shape/figure name | +| TM_CELL_TISSUE | – cells/organs/tissues(invisible outside) | + +**Table I.1 – Named entity types** + +| Named entity subtypes | Description | +|------------------------------|---------------------------------------------------------------------| +| TMM_DISEASE | – symptoms/disease | +| TMM_DRUG | – drug names | +| TMI_HW | – IT hardware terms | +| TMI_SW | – IT software terms | +| TMI_SITE | – URL address | +| TMI_EMAIL | – email address | +| TMI_MODEL | – model names and part names | +| TMI_SERVICE | – IT service terms | +| TMI_PROJECT | – project name | +| TMIG_GENRE | – game genre | +| TM_SPORTS | – terms for sports and leisure activity (names for technique/rules) | + +## Bibliography + +- [b-ITU-T H.703] Recommendation ITU-T H.703 (2016), *Enhanced user interface framework for IPTV terminal devices*. + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git 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sha256:682c6faa0c5ebb281dbf14dedf5f4a72bd3b5f0f2ebdb9f12dc1e872558dfb40 +size 133748 diff --git a/marked/F/T-REC-F.746.8-201808-I_PDF-E/raw.md b/marked/F/T-REC-F.746.8-201808-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..3a95bd68cbe5eacfcf22f5210876925a6195045e --- /dev/null +++ b/marked/F/T-REC-F.746.8-201808-I_PDF-E/raw.md @@ -0,0 +1,345 @@ + + +International Telecommunication Union + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**F.746.8** + +(08/2018) + +SERIES F: NON-TELEPHONE TELECOMMUNICATION +SERVICES + +Multimedia services + +--- + +**Requirements for unified status monitoring of +networks and services** + +Recommendation ITU-T F.746.8 + +**ITU-T** + +![ITU logo: A globe with a red lightning bolt and the text 'ITU International Telecommunication Union'.](1d7527f4316cfe2d342b08d1653d1592_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a stylized globe with a red lightning bolt striking across it. To the right of the globe, the text "ITU" is written in a bold, blue font, and below it, "International Telecommunication Union" is written in a smaller, blue font. + +ITU logo: A globe with a red lightning bolt and the text 'ITU International Telecommunication Union'. + +# ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multdestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| MULTIMEDIA SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.746.8 + +# Requirements for unified status monitoring of networks and services + +## Summary + +Recommendation ITU-T F.746.8 describes requirements and functional architecture for a unified status monitoring (USM) system that allows network providers and application service providers (ASPs) to get the status information they need. The USM system, which consists of a USM server and a set of USM agents, collects both static and dynamic status information from network providers and ASPs. It can also parse the status requests from network providers and ASPs, generate the status reports and send the reports back to them. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.746.8 | 2018-08-29 | 16 | 11.1002/1000/13659 | + +## Keywords + +Application service provider, network provider, status monitoring, two-way information sharing. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2018 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|---------------------------------------------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 2 | +| 6 Overview..... | 2 | +| 7 Requirements for the USM system..... | 3 | +| 7.1 General requirements..... | 3 | +| 7.2 Requirements for an USM agent ..... | 3 | +| 7.3 Requirements for the USM server ..... | 3 | +| 8 Functional architecture of the USM system ..... | 3 | +| 8.1 USM agent..... | 4 | +| 8.2 USM server..... | 4 | +| 9 Security considerations ..... | 5 | +| Appendix I – Use cases of the unified status monitoring system ..... | 6 | +| I.1 Use case 1: USM providing extra status information for network
upgrading..... | 6 | +| I.2 Use case 2: USM providing extra status information for application-level
optimization..... | 6 | +| Bibliography..... | 7 | + + + +# Recommendation ITU-T F.746.8 + +## Requirements for unified status monitoring of networks and services + +# 1 Scope + +This Recommendation describes requirements for a unified status monitoring (USM) system. The USM system collects status information from application service providers (ASPs) as well as network providers and sends analysed results back to them. + +This Recommendation covers: + +- requirements for the USM system and its key components; +- functional architecture of the USM system. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T L.25] Recommendation ITU-T L.25 (2015), *Optical fibre cable network maintenance*. + +[ITU-T L.311] Recommendation ITU-T L.311/L.93 (2014), *Optical fibre cable maintenance support, monitoring and testing systems for optical fibre trunk networks*. + +[ITU-T Y.2201] Recommendation ITU-T Y.2201 (2009), *Requirements and capabilities for ITU-T NGN*. + +[ITU-T Y.2701] Recommendation ITU-T Y.2701 (2007), *Security requirements for NGN release 1*. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 application service provider (ASP)** [b-ITU-T H.360]: A service provider providing application services. + +NOTE – The same business entity may act as both network operator and application service provider. + +**3.1.2 network provider** [b-ITU-T H.780]: The organization that maintains and operates the network components required to support a service or set of services. + +### 3.2 Terms defined in this Recommendation + +This Recommendation defines the following term: + +**3.2.1 unified status monitoring (USM)**: A type of monitoring that allows network providers and application service providers to get the status information they need in a unified way. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|-------------------------------------------------------------| +| ALTO | Application-Layer Traffic Optimization | +| ASP | Application Service Provider | +| DASH | Dynamic Adaptive Streaming over Hypertext transfer protocol | +| I/O | Input/Output | +| ISP | Internet Service Provider | +| MOCC | Multimedia Optimization Control Components | +| QoE | Quality of Experience | +| USM | Unified Status Monitoring | + +## 5 Conventions + +This Recommendation employs the following conventions. + +- The expression "**is required to**" indicates a requirement which must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. +- The expression "**is recommended**" indicates a requirement which is recommended but not absolutely required. Thus, this requirement need not be present to claim conformance. + +## 6 Overview + +In current networks, network providers or Internet service providers (ISPs) monitor the status of networks by all kinds of measurement methods. However, there is lack of easy way for ASPs, e.g., video-sharing websites or providers, to get status information about the underlying networks, i.e., network-level status information. There are some efforts that try to provide some network-level status information to the ASPs. For example, both application-layer traffic optimization (ALTO) of [b-IETF RFC 7285] and multimedia optimization control components (MOCCs) of [b-ITU-T F.746] define one-way information-sharing mechanisms that help specific applications to get reliable information about underlying networks, e.g., network topology information. Such information can be used by ASPs to select an appropriate server or switch to another network to achieve better performance. + +On the other hand, more and more ASPs adopt their own end-to-end measurement methods, such as dynamic adaptive streaming over hypertext transfer protocol (DASH) ([b-ISO/IEC TR 23009-3], [b-Stockhammer]), and adjust the behaviour of their applications based on the measurements and the inferred network status. However, this end-to-end measurement information and the decisions of ASPs, called the application-level status information, are still unknown to network providers. + +To enhance the performance of applications and networks, ASPs and network providers should have better understanding of the status of the network level, as well as that of the application level, which means two-way information sharing is needed. One possible way is to establish a USM system that collects both static and dynamic status information from network providers and ASPs. The static status information includes local configurations, e.g., the network topology, and the locations of servers. The dynamic status information includes real-time raw status data, e.g., the link state, and the load on a server. It can also parse status requests from network providers and ASPs, generate status reports, and send reports back to them. + +For example, the status of optical fibres is monitored by optical fibre network owners. Cuts in fibre cable can be detected by traditional link detection technologies as in [ITU-T L.25], [ITU-T L.311] or more sophisticated path and trail monitoring technologies such as M-Trail in [b-Wu]. If the ASP can get the information in a timely fashion, it may switch traffic to another ISP that is not using the failed cable. At the same time, status information about traffic demand among different data centres can be + +measured by these ASPs. If the network provider can get this information, it can achieve much better bandwidth utilization and less congestions [b-Jain]. + +## **7 Requirements for the USM system** + +This clause addresses the requirements for the USM system. + +## **7.1 General requirements** + +GEN-01: The USM system is required to collect static status information and dynamic status information from network providers and ASPs. + +GEN-02: The USM system is required to manage status information, including static status information and dynamic status information, of network providers and ASPs. + +GEN-03: The USM system is required to generate status reports according to requests from network providers and ASPs using static status information and dynamic status information. + +### **7.2 Requirements for an USM agent** + +UA-01: A USM agent is required to support interaction with network providers or ASPs on behalf of the USM server. + +UA-02: A USM agent is required to support the static status information management function to receive static status information that is sent by a network provider or an ASP and forward that information to the USM server. + +UA-03: A USM agent is required to support the dynamic status information management function to query dynamic status information about a network provider or an ASP according to the command of the USM server and forward retrieved dynamic status information to the USM server. + +UA-04: A USM agent is required to support the supplementary information management function to request status reports from the USM server and forward those reports to the network provider or ASP. + +### **7.3 Requirements for the USM server** + +US-01: A USM server is required to support the unified data management function to store static status information collected from network providers and ASPs. + +US-02: A USM server is required to support the parse/synthesize function to parse the status request. + +US-03: A USM server is required to support the parse/synthesize function to retrieve the needed raw data by querying the unified data management module and the dynamic information management modules of one or more USM agents, if necessary. + +US-04: A USM server is required to support the parse/synthesize function to synthesize the retrieved raw status data to generate a status report and send it back to the USM agents. + +US-05: A USM server is recommended to store the retrieved dynamic status information. + +## **8 Functional architecture of the USM system** + +Figure 8-1 shows the functional architecture of the USM system. A USM system consists of a USM server and a set of USM agents. The USM system interacts with network providers and ASPs. The functional entities of networks providers and ASPs lie outside the scope of this Recommendation. The USM system collects the status information from network providers and ASPs. The USM system can parse the status requests from network providers and ASPs, generate the status reports, and send the reports back to them. + +![Functional architecture of the unified status monitoring system diagram](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +The diagram illustrates the functional architecture of a unified status monitoring system. At the top, a dashed box labeled 'Unified status monitoring system' contains the 'USM server'. The server has two main modules: 'Unified data management' and 'Parse/synthesize'. Below these modules are three I/O interfaces: 'Static information I/O', 'Dynamic information I/O', and 'Unified status I/O'. Below the server, there are two 'USM agent' boxes, labeled 'USM agent 1' and 'USM agent 2', with an ellipsis between them. Each agent contains three modules: 'Static information management', 'Dynamic information management', and 'Supplement information management'. Below each agent is a 'Network provider/application service provider' box, also with an ellipsis between them. Arrows indicate the flow of data: red dashed arrows for 'Send raw status data' from agents to the server; blue dashed arrows for 'Query raw status data' from the server to agents; purple solid arrows for 'Request status reports' from agents to the server; and light blue dashed arrows for 'Return status reports' from the server to agents. A legend at the bottom explains these arrow types. The identifier 'F.746.8(18)\_F8-1' is in the bottom right corner. + +Functional architecture of the unified status monitoring system diagram + +**Figure 8-1 – Functional architecture of the unified status monitoring system** + +### 8.1 USM agent + +A USM agent is responsible for interacting with a network provider or an ASP on behalf of the USM server. There are three modules in the USM agent, i.e., static information management module, dynamic information management module and supplementary information management module. + +The static information management module is used to receive static status information, such as network topology or locations of application servers, from a network provider or ASP. It then forwards the collected information to the USM server. + +The dynamic information management module is responsible for querying dynamic status information, e.g., real-time raw status data of providers according to the command of the USM server and sending the retrieved status data to the USM server. + +The supplementary information management module is responsible for requesting status reports from the USM server on behalf of network providers and ASPs and returning the received status reports. Such information can be used by providers for further optimization. + +### 8.2 USM server + +The USM server is responsible for managing status information, including static status information and dynamic status information, of network providers and ASPs. There are two major functional modules in the USM server, the unified data management module and the parse/synthesize module, and three input/output (I/O) interfaces, including static information I/O, dynamic information I/O and unified status I/O. + +The unified data management module is responsible for storing the static status information collected from network providers and ASPs through the static information I/O. + +The parse/synthesize module is used to parse the status request, which is received from the unified status I/O, and then retrieves the needed raw status data by querying the unified data management module of the USM server and dynamic information management modules of one or more USM + +agents, if necessary. After collecting all needed raw status data, the parse/synthesize module synthesizes these data and sends the reports generated to the USM agents through the unified status I/O. + +## **9 Security considerations** + +It is recommended that the security requirements of [ITU-T Y.2201], [ITU-T Y.2701], and applicable ITU-T X-series, ITU-T Y-series and ITU-T M-series security Recommendations, be taken into consideration, which includes access control, authentication, data confidentiality, communications security, data integrity, availability and privacy. + +## Appendix I + +### Use cases of the unified status monitoring system + +(This appendix does not form an integral part of this Recommendation.) + +### **I.1 Use case 1: USM providing extra status information for network upgrading** + +Network upgrading is often done to improve performance and reliability, and support new applications. It is very important to monitor the upgraded network and the impact on applications. If status information about applications [such as the quality of experience (QoE)] is available to the network provider, it can have a better chance to make appropriate decisions rather than making too conservative or too aggressive decisions. + +### **I.2 Use case 2: USM providing extra status information for application-level optimization** + +When a client of an application has a bad QoE, it may want to switch to another server to achieve a better QoE. If the bad QoE is results from traffic congestion on the ISP, it is useless to switch to another server. In this scenario, if the application client has been provided with extra information about network status, such useless switching can be avoided. + +## Bibliography + +- [b-ITU-T F.746] Recommendation ITU-T F.746 (2012), *Requirements of multimedia optimization control components*. +- [b-ITU-T H.360] Recommendation ITU-T H.360 (2014), *An architecture for end-to-end QoS control and signalling*. +- [b-ITU-T H.780] Recommendation ITU-T H.780 (2012), *Digital signage: Service requirements and IPTV-based architecture*. +- [b-IETF RFC 7285] IETF RFC 7285 (2014), *Application-layer traffic optimization (ALTO) protocol*. +- [b-ISO/IEC TR 23009-3] ISO/IEC TR 23009-3:2015, *Information technology – Dynamic adaptive streaming over HTTP (DASH) – Part 3: Implementation guidelines*. +- [b-Jain] Jain, S., Kumar, A., Mandal, S., Ong, J., Poutievski, L., Singh, A., Venkata, S., Wanderer, J., Zhou, J., Zhu, M., Zolla, J., Hölzle, U., Stuart S., Vahdat, A. (2013). B4: Experience with a globally-deployed software defined WAN. In: *Proceedings of the ACM SIGCOMM 2013 conference on SIGCOMM*, pp. 3–14. New York, NY: ACM. +- [b-Stockhammer] Stockhammer, T; (2011). Dynamic adaptive streaming over HTTP – Standards and design principles. In: *Proceedings of the Second Annual ACM Conference on Multimedia Systems*, San Jose, CA, USA, 2011-02-23/25, pp. 133–144. New York, NY: ACM +- [b-Wu] Wu, B., Ho, P.-H., Yeung, K.L. (2009). Monitoring trail: On fast link failure localization in all-optical WDM mesh networks. *Journal of Lightwave Technology* **27**, pp. 4175–4185. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.747.14-202406-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg b/marked/F/T-REC-F.747.14-202406-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..071c14a22675a168eba8ed3cbf67b3d5a536ebe8 --- /dev/null +++ b/marked/F/T-REC-F.747.14-202406-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ed235d6444f272adf7b589de631f73f3f3fb938c821d743153cab563d680550c +size 7266 diff --git a/marked/F/T-REC-F.747.14-202406-I_PDF-E/562f471e8153729557e6a4ee6343c32c_img.jpg b/marked/F/T-REC-F.747.14-202406-I_PDF-E/562f471e8153729557e6a4ee6343c32c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e4cd716408fc65f8ac50a77690930b8dff40c674 --- /dev/null +++ b/marked/F/T-REC-F.747.14-202406-I_PDF-E/562f471e8153729557e6a4ee6343c32c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:bd59ddb6546ef8be509073be8cebca7b7fdb7337e674792b62a7accbec18ba58 +size 71226 diff --git a/marked/F/T-REC-F.747.14-202406-I_PDF-E/78f163db583eb0c6d013e6f8ffe6d7d8_img.jpg b/marked/F/T-REC-F.747.14-202406-I_PDF-E/78f163db583eb0c6d013e6f8ffe6d7d8_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ac9c8448373e17d2a5bb6821580221b8a6384341 --- /dev/null +++ b/marked/F/T-REC-F.747.14-202406-I_PDF-E/78f163db583eb0c6d013e6f8ffe6d7d8_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:a9dc00d25ee6f2f96cf76f62df641d3e782bbd6b9c0a5f9e9bc6409580dd2ea5 +size 54796 diff --git a/marked/F/T-REC-F.747.14-202406-I_PDF-E/d26959f4514c26ca19c3d6f00da85956_img.jpg b/marked/F/T-REC-F.747.14-202406-I_PDF-E/d26959f4514c26ca19c3d6f00da85956_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..7a5d0c3bcce35670f58160c91f19626f5d0600e7 --- /dev/null +++ b/marked/F/T-REC-F.747.14-202406-I_PDF-E/d26959f4514c26ca19c3d6f00da85956_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d609b42bbeb87a1cd5573d5a5c53c4d99dd1b7e0178e9a91f3fde50299c325bb +size 118712 diff --git a/marked/F/T-REC-F.747.14-202406-I_PDF-E/eb22a8740f7c6a0f6ee98f16d99ed8b9_img.jpg b/marked/F/T-REC-F.747.14-202406-I_PDF-E/eb22a8740f7c6a0f6ee98f16d99ed8b9_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..decd3a9b336bad1f5b41806d184d815e2aae9efc --- /dev/null +++ b/marked/F/T-REC-F.747.14-202406-I_PDF-E/eb22a8740f7c6a0f6ee98f16d99ed8b9_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5e59190602d4bffd04da2d78b3be30dd64d4da5e80101ca383277c3e42af77b3 +size 79065 diff --git a/marked/F/T-REC-F.747.14-202406-I_PDF-E/raw.md b/marked/F/T-REC-F.747.14-202406-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..9f8ffbadf6b8a176670c3c09c00df7d3cb0bf206 --- /dev/null +++ b/marked/F/T-REC-F.747.14-202406-I_PDF-E/raw.md @@ -0,0 +1,456 @@ + + +# Recommendation **ITU-T F.747.14 (06/2024)** + +SERIES F: Non-telephone telecommunication services +Multimedia services + +--- + +## **Requirements and capability framework of the multimodal fusion system for vision** + +![ITU logo](390120de4fe440c42fea8154fcaad334_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.747.14 + +# Requirements and capability framework of the multimodal fusion system for vision + +## Summary + +With the rampant development of big data and artificial intelligence some new modal types data for vision have emerged, such as light detection and ranging (LiDAR) data, radar data 3D data, etc. Multimodal fusion for vision is one new technology for higher quality human eye presentation or higher performance machine vision tasks. The multimodal fusion system for vision will be popular among the future vision systems. The multimodal fusion system focuses on specific methods of multimodal data fusion. + +Recommendation ITU-T F.747.14 specifies the requirements and capability framework to accommodate the existing and newly developed visual facilities for multimodal fusion for vision applications including autonomous vehicles, autonomous robot navigation and weather visibility prediction. This Recommendation defines the related requirements, capability framework and reference use cases for the multimodal fusion system for vision. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.747.14 | 2024-06-13 | 16 | 11.1002/1000/15908 | + +## Keywords + +Capability framework, multimodal fusion, requirements, vision. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2024 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|----------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Overview of multimodal fusion for vision ..... | 2 | +| 7 Requirements of multimodal fusion system for vision..... | 3 | +| 7.1 Data acquisition ..... | 3 | +| 7.2 Data transmission ..... | 4 | +| 7.3 Data fusion..... | 4 | +| 7.4 Data analysis..... | 4 | +| 7.5 Security and personally identifiable information protection..... | 5 | +| 8 Capability framework of multimodal fusion system for vision..... | 5 | +| 8.1 Capabilities for data acquisition ..... | 5 | +| 8.2 Capabilities for data transmission ..... | 5 | +| 8.3 Capabilities for data processing..... | 6 | +| 8.4 Capabilities for data fusion..... | 6 | +| 8.5 Capabilities for data analysis..... | 6 | +| Appendix I – Use cases of multimodal fusion system for vision..... | 7 | +| I.1 Use case of autonomous vehicles ..... | 7 | +| I.2 Use case of autonomous robot navigation..... | 7 | +| I.3 Use case of weather visibility prediction..... | 8 | +| Bibliography..... | 9 | + + + +## Requirements and capability framework of the multimodal fusion system for vision + +# 1 Scope + +This Recommendation specifies the requirements, capability framework and use cases of the multimodal fusion system for vision to complement the development on common requirements and framework of multimodal fusion in terms of vision-related system. The requirements of the multimodal fusion system for vision are independent of any specific application. + +The scope of this Recommendation includes: + +- Requirements of the multimodal fusion system for vision. +- Capability framework of the multimodal fusion system for vision. + +Use cases of the multimodal fusion system for vision are provided in Appendix I. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T F.743] Recommendation ITU-T F.743 (2019), *Requirements and service description for video surveillance.* +- [ITU-T F.743.1] Recommendation ITU-T F.743.1 (2015), *Requirements for intelligent visual surveillance.* +- [ITU-T H.626] Recommendation ITU-T H.626 (2019), *Architectural requirements for video surveillance system.* + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +- 3.1.1 algorithm** [b-ISO/IEC 11557]: A set of rules for transforming the logical representation of data. +- 3.1.2 application** [b-ITU-T Y.101]: A structured set of capabilities, which provide value-added functionality supported by one or more services. +- 3.1.3 machine vision** [b-ITU-T F.748.16]: Signal processing to acquire, process and interpret an image or video to support visual analysis for applications, such as automatic inspection, process control and guidance.. +- 3.1.4 model** [b-ITU-T F.748.16]: An output created by an algorithm running on training data that can generate an inference or prediction, based on input data. + +**3.1.5 video surveillance system** [ITU-T H.626]: A telecommunication service focusing on video (but including audio and image) application technology, which is used to remotely capture multimedia (such as audio, video, image, alarm signal, etc.) and present them to the end user in a user friendly manner, based on managed broadband network with ensured quality, security and reliability. + +### 3.2 Terms defined in this Recommendation + +None. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +GNSS Global Navigation Satellite System + +HDR High Dynamic Range + +LiDAR Light Detection and Ranging + +ML Machine Learning + +## 5 Conventions + +In this Recommendation: + +The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. + +The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement needs not be present to claim conformance. + +The keywords "can optionally" and "may" indicate an optional requirement which is permissible, without implying any sense of being recommended. These terms are not intended to imply that the vendor's implementation must provide the option, and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the specification. + +# 6 Overview of multimodal fusion for vision + +Multimodal fusion system focuses specifically on the fusion technology of different modalities to achieve better performance of both reconstruction and machine vision tasks. + +NOTE – Fusion technology aims to integrate multiple data sources to produce more consistent, accurate and useful information than that provided by any individual data source. + +The following capability components are identified to support the multimodal fusion system for vision: data acquisition, data transmission, data fusion and data analysis, as shown in Figure 1. + +For the existing multimodal fusion framework, the decision layer fusion framework is usually used in the scene. This framework will distinguish capabilities and frameworks in the following aspects: + +- Multimodal fusion system for vision online + - Fusion with different levels (including signal level and feature level) compatible with devices with different capabilities. +- Capabilities + - Capabilities for data acquisition. + - Capabilities for data processing (temporal alignment, spatial alignment, data quality evaluation). + - Capabilities for data fusion (signal level, feature level and decision level). + +- Capabilities for data transmission. +- Capabilities for data analysis. + +The whole multimodal fusion system for vision consists of four parts: data acquisition, data fusion, data transmission and data analysis. Data acquisition collects all the data required for post processing. Data fusion is performed depending on the multi modal input including the signal level fusion, and feature level fusion based on the device capability. Data transmission is responsible for transmitting the data in the system. Data analysis receives the processed data and then analyses all the data for different applications. + +![Figure 1 – Overview of the multimodal fusion for vision system. The diagram shows a flow from Data acquisition to Data transmission to Data analysis. Data acquisition includes visual data feature extraction (Image, Video, Depth graph) and visual supplementary data feature extraction (Text, Audio). Data transmission is a Transmission network. Data analysis includes Edge device and Cloud platform, both leading to an Application. Circular nodes labeled 'Multimodal fusion (Signal/feature)' are shown below the main flow, with arrows pointing to the Data acquisition and Data analysis stages.](562f471e8153729557e6a4ee6343c32c_img.jpg) + +``` + +graph LR + subgraph DA [Data acquisition] + subgraph VDFE [Visual data feature extraction] + I[Image] + V[Video] + DG[Depth graph] + end + subgraph VSDFE [Visual supplementary data feature extraction] + T[Text] + A[Audio] + end + end + DA --> TN [Transmission network] + TN --> ED [Edge device] + TN --> CP [Cloud platform] + ED --> APP1 [Application] + CP --> APP2 [Application] + MF1((Multimodal fusion +(Signal/feature))) -.-> DA + MF2((Multimodal fusion +(Signal/feature))) -.-> DA + MF3((Multimodal fusion +(Signal/feature))) -.-> ED + MF4((Multimodal fusion +(Signal/feature))) -.-> CP + +``` + +Figure 1 – Overview of the multimodal fusion for vision system. The diagram shows a flow from Data acquisition to Data transmission to Data analysis. Data acquisition includes visual data feature extraction (Image, Video, Depth graph) and visual supplementary data feature extraction (Text, Audio). Data transmission is a Transmission network. Data analysis includes Edge device and Cloud platform, both leading to an Application. Circular nodes labeled 'Multimodal fusion (Signal/feature)' are shown below the main flow, with arrows pointing to the Data acquisition and Data analysis stages. + +F.747.14(24) + +**Figure 1 – Overview of the multimodal fusion for vision system** + +# 7 Requirements of multimodal fusion system for vision + +The requirements of multimodal fusion system for vision can be classified into requirements for data acquisition, data transmission, data fusion and data analysis. The requirements for system management and security are defined in [ITU-T F.743] and [ITU-T F.743.1]. The communication between the different devices in data acquisition is defined in [ITU-T H.626]. + +### 7.1 Data acquisition + +- The system is recommended to support high or ultra-high-resolution images and videos to satisfy intelligent analysis. +- The system is required to have lighting conditions according to the different application scenarios such as automatic drive and intelligent transport. +- The system is recommended to support brightness anomaly diagnosis and restoration function, including brightness adjustment and enhancement of whole or part of the image or video and strong light suppression. +- The system is recommended to support automatic adjustment of the high dynamic range (HDR) parameters according to the brightness change in the environment and to support the backlight compensation function to ensure the monitoring object is clear and recognizable. +- The system is required to upload the vision data on demand to the edge computing device and cloud platform for intelligent analysis. + +- The system is recommended to perform visual data compression and data compression before data are transmitted to the edge computing device or cloud platform for intelligent analysis, alleviating the high data volume transmitted by the network. +- The system is recommended to have an identification for collaboration. +- The system is recommended to support a basic data processing method that includes cropping, padding, up-sampling, down-sampling, de-fogging, de-noising and de-distorting. +- The system is recommended to support feature extraction methods including human-designed descriptors, preliminary vision features and semantic features for machine learning (ML) model tasks. +- The system is recommended to upload the results of vision feature extraction to the edge computing device or cloud platform for intelligent analysis. +- The system is recommended to support global navigation satellite system (GNSS) information including longitude, latitude and height information. +- The system is recommended to support time information. +- The system is recommended to be supported by additional information provided by other sensors. + +### 7.2 Data transmission + +- The transmission network bandwidth of upstream rate is recommended to satisfy the maximum video bitrate and key frames of the video bitrates according to the application requirements. +- The transmission network is recommended to support wired access for supporting different application scenarios and time sensitive services. For services with low latency requirements, the access network is required to support different access modes, including optical fibre access, hybrid fibre, copper shaft access and wireless access modes. +- The transmission network is recommended to satisfy both time sensitive and time insensitive applications. + +### 7.3 Data fusion + +- Data fusion is recommended to support the selection of suitable source information from data acquisition. +- Data fusion is recommended to support the improvement of performance in data analysis. +- Data fusion is recommended to support different level visual data fusion. +- Data fusion is recommended to support different modal visual data fusion in the same level. +- Data fusion is recommended to support data fusion with visual data and visual supplementary data. + +### 7.4 Data analysis + +- The cloud platform or the edge device is recommended to support visual data analysis ability, including classification, object detection, instance segmentation, object tracking, event detection and action recognition. +- The cloud platform or the edge device is recommended to support analyses based on reconstructed pictures or videos. +- The cloud platform or the edge device is recommended to support analyses based on visual and visual supplementary features. + +### 7.5 Security and personally identifiable information protection + +The multimodal fusion system for vision is recommended to support verification mechanisms, encryption mechanisms, version control and access control to ensure the integrity of specific data in the acquisition process, storage process and transmission process, including but not limited to identification data, configuration data and visual data. + +# 8 Capability framework of multimodal fusion system for vision + +The capabilities for visual and visual supplementary data acquisition, fusion, processing, transmission, and analyzation are illustrated in Figure 2. + +![Figure 2: Capability framework of multimodal fusion system for vision. The diagram is a hierarchical tree structure showing the capabilities of a multimodal fusion system. It is organized into five horizontal layers, each representing a different capability area. The layers are: Data analysis (top), Data fusion, Data processing, Data transmission, and Data acquisition (bottom). Each layer contains a list of sub-capabilities in boxes.](d26959f4514c26ca19c3d6f00da85956_img.jpg) + +| | | | | | | +|-------------------|---------------------|---------------------|-----------------------|-------------------------|-------------------------| +| Data analysis | Model training | Model inference | Machine vision task | Reconstruction task | | +| Data fusion | Signal level fusion | | Feature level fusion | | | +| Data processing | Feature extraction | Feature compression | Time synchronization | Spatial synchronization | Data quality evaluation | +| Data transmission | Wired transmission | | Wireless transmission | | | +| Data modalities | Image | Video | Text | Audio | Distance graph | +| Data acquisition | Camera | Mobile phone | Sensor | Radar | | + +Figure 2: Capability framework of multimodal fusion system for vision. The diagram is a hierarchical tree structure showing the capabilities of a multimodal fusion system. It is organized into five horizontal layers, each representing a different capability area. The layers are: Data analysis (top), Data fusion, Data processing, Data transmission, and Data acquisition (bottom). Each layer contains a list of sub-capabilities in boxes. + +F.747.14(24) + +Figure 2 – Capability framework of multimodal fusion system for vision + +### 8.1 Capabilities for data acquisition + +During the data acquisition process, the system collects data for the subsequent stages with visual devices and supplementary visual devices. As illustrated in Figure 1, the system could acquire images, videos, text, audio, distance graph and other data through visual devices such as cameras mobile phone, sensor, radar and others. Different modalities data are captured separately for further transmission. + +### 8.2 Capabilities for data transmission + +The multiple modality data obtained from data acquisition is output through wired transmission, such as optical fibre, or wireless transmission, such as industrial WIFI or 5G, for further processing and analysis. The configuration of network needs to consider high bandwidth and low latency to ensure that the uplink rate meets the transmission capability of multiple modality data, and low latency meets the needs of online applications. + +### 8.3 Capabilities for data processing + +Upon data collection, the data acquisition process performs a feature compression operation on the acquired data as follows. The system inputs the images into a neural network designed for feature compression. For each alternative layer within the neural network, the feature values of the images output by that layer are compressed based on the current bit-depth value to obtain compressed feature values. The current bit-depth value should be greater than or equal to the predefined minimum value. + +After compressing the feature values, the system inputs them into the layer connected to the alternative layer to determine the evaluation metric of this neural network. If the metric does not meet the predefined threshold, the system increases the current bit-depth value by the predefined step size and re-compresses the feature values of the output of the images by the alternative layer based on the current bit-depth value. This process is repeated until the current bit-depth value reaches the predefined maximum value or the evaluation metric of the neural network reaches the predefined threshold. Upon reaching the predefined threshold for the evaluation metric of the neural network, the system calculates the sum or average of the data volume of the compressed feature values for each image corresponding to the alternative layer, serving as the data volume of the compressed feature values for that layer and acting as the reference metric for the alternative layer. + +The system compares the reference metrics of each alternative layer and selects the layer with the minimum reference metric as the layer to be compressed. And then the system compresses the feature values output by this selected layer during the process of using this neural network to obtain the corresponding output results. + +Data processing also includes time synchronization, spatial synchronization, and vision data quality evaluation. Time synchronization refers to the fact that data captured by different devices support unified reference time for alignment. Spatial synchronization refers to the fact that data captured by different devices support calibration into the same coordinate system. Data quality evaluation supports the evaluation and removal of poor quality, invalid and malicious data. + +### 8.4 Capabilities for data fusion + +Data fusion includes two types: signal level fusion, and feature level fusion. + +Signal level fusion refers to alignment of original modalities data and image pixel level combination. The alignment of original modalities data refers to montage of text and images and the fusion of videos and audios. Pixel level fusion refers to the original image alignment in the input level to increase the information in visual aspect and computer processing. The pixel level fusion for images includes two methods. One method is to directly weigh and average the pixels from multiple images, usually determining the weight based on the activity of different pixels. Another method is to utilize the spatial correlation between the adjacent pixels which can be achieved through post-processing of the initial pixel level weight map. + +Feature level fusion refers to the extraction of features from different modal data such as image, audio and text, and fusion in the latent domain such as the principle of CLIP [b-CLIP], a pretrained model for comparing text and image pairs, which can learn the matching relationship between the text and image pairs. The pretrained model achieves unsupervised learning on unknown datasets. + +NOTE – Unknown datasets refers to the data without the label and used for evaluation of the ML model performance. + +### 8.5 Capabilities for data analysis + +The information after data fusion is further processed for model training and model inference. The analysis side supports various machine vision tasks and reconstruction tasks by adding detection heads. Machine vision tasks include image classification, object detection, instance segmentation and object tracking. The reconstruction task includes high-quality reconstruction of vision data. For data analysis with requirements constraints, edge computing and cloud computing can be combined. + +## Appendix I + +### Use cases of multimodal fusion system for vision + +(This appendix does not form an integral part of this Recommendation.) + +### I.1 Use case of autonomous vehicles + +The integration of multiple sensor streams, such as camera, (Light Detection and Ranging) LiDAR, and radar data, is crucial for object detection in autonomous vehicles, as these inputs form the basis for their decision-making processes. While some current methods are effective under normal environmental conditions, they struggle in adverse weather conditions where sensor data may be distorted. These uncommon "edge-case" scenarios are often not adequately represented in available datasets, and existing fusion architectures are ill-equipped to handle them. [b-IEEE\_CVPR20] introduced a novel model that dynamically fuses features based on measurement entropy to address this challenge. The test vehicle set up with top-mounted LiDAR, and gated camera with flash are illustrated in Figure I.1. + +![Figure I.1: Test vehicle set up with top-mounted LiDAR, gated camera with flash illumination. The image shows a silver sedan with various sensors mounted on its roof and front. Labels with red arrows point to each sensor: 'Stereo camera Aptina AR0230 1920x1080', 'Velodyne HDL64-S3 903 nm, 64-layer', 'Weather station Airmar WX150', 'FIR camera Axis Q1922 640x480, 100 mK', 'Velodyne VLP32 903 nm, 32-layer', 'Proprietary radar', and 'Road-friction sensor Vaisala prototype'. A circular inset on the left shows a close-up of the 'Gated camera BrightwayVision 808 nm, 1280x720' with a flash unit. The text 'Vehicle setup' is centered above the car, and 'Weather distribution' and 'F.747.14(24)' are at the bottom.](eb22a8740f7c6a0f6ee98f16d99ed8b9_img.jpg) + +Vehicle setup + +Stereo camera +Aptina AR0230 +1920×1080 + +Velodyne HDL64-S3 +903 nm, 64-layer + +Weather station +Airmar WX150 + +FIR camera +Axis Q1922 +640×480, 100 mK + +Velodyne VLP32 +903 nm, 32-layer + +Proprietary radar + +Road-friction sensor +Vaisala prototype + +Gated camera +BrightwayVision +808 nm, 1280×720 + +Weather distribution + +F.747.14(24) + +Figure I.1: Test vehicle set up with top-mounted LiDAR, gated camera with flash illumination. The image shows a silver sedan with various sensors mounted on its roof and front. Labels with red arrows point to each sensor: 'Stereo camera Aptina AR0230 1920x1080', 'Velodyne HDL64-S3 903 nm, 64-layer', 'Weather station Airmar WX150', 'FIR camera Axis Q1922 640x480, 100 mK', 'Velodyne VLP32 903 nm, 32-layer', 'Proprietary radar', and 'Road-friction sensor Vaisala prototype'. A circular inset on the left shows a close-up of the 'Gated camera BrightwayVision 808 nm, 1280x720' with a flash unit. The text 'Vehicle setup' is centered above the car, and 'Weather distribution' and 'F.747.14(24)' are at the bottom. + +**Figure I.1 – Test vehicle set up with top-mounted LiDAR, gated camera with flash illumination [b-IEEE\_CVPR20]** + +### I.2 Use case of autonomous robot navigation + +Object detection is a crucial task for autonomous robots navigating dynamic and evolving environments. Figure I.2 shows that vision-based detection fails in very dark environments and under motion blur, while it performs well in outdoor scenarios and for larger distances, where depth images are usually noisy. It is imperative for robots to identify objects despite sensor noise, such as fluctuating lighting conditions affecting cameras and inaccurate depth readings from range sensors, particularly RGB-D cameras. To address these challenges, [b-ArXiv] proposed an adaptive fusion approach for object detection. This approach dynamically learns to weigh predictions from different sensor modalities. The system relies on a blend of convolutional neural network (CNN) experts and integrates various modalities, including appearance, depth and motion. Through extensive robot experiments, this system effectively detects people in diverse indoor and outdoor settings using + +RGB-D data, showcasing adaptability to challenging lighting variations and significant camera motion blur. + +![Figure 1.2: Vision-based detection in different scenarios. The figure consists of four panels arranged in a 2x2 grid. The top-left panel shows an RGB image of four people walking on a sidewalk in front of a building. The top-right panel shows the corresponding depth map for the same scene, with the people highlighted in different colors. The bottom-left panel shows a low-light RGB image of two people walking through a doorway, with the word 'People' and two arrows pointing to them. The bottom-right panel shows the corresponding depth map for the low-light scene, with the people still clearly visible. A small label 'F.747.14(24)' is visible in the bottom right corner of the bottom-right panel.](78f163db583eb0c6d013e6f8ffe6d7d8_img.jpg) + +Figure 1.2: Vision-based detection in different scenarios. The figure consists of four panels arranged in a 2x2 grid. The top-left panel shows an RGB image of four people walking on a sidewalk in front of a building. The top-right panel shows the corresponding depth map for the same scene, with the people highlighted in different colors. The bottom-left panel shows a low-light RGB image of two people walking through a doorway, with the word 'People' and two arrows pointing to them. The bottom-right panel shows the corresponding depth map for the low-light scene, with the people still clearly visible. A small label 'F.747.14(24)' is visible in the bottom right corner of the bottom-right panel. + +**Figure 1.2 – Vision-based detection in different scenarios [b-IEEE\_arXiv]** + +### **I.3 Use case of weather visibility prediction** + +Visibility is a crucial aspect impacting various modes of transportation, including roads, maritime activities and aviation. Accurate visibility prediction is essential for both production and daily life. Unlike weather prediction, which primarily relies on atmospheric factors, meteorological visibility is influenced by a multitude of complex factors, such as air pollution stemming from industrial emissions. However, current visibility prediction methods predominantly employ numerical prediction techniques similar to those used in weather forecasting. [b-IEEE\_Access] proposed a novel approach that utilizes multimodal fusion to develop a weather visibility prediction system. This method leads to enhanced accuracy in the visibility prediction system. + +## Bibliography + +- [b-ITU-T F.748.16] Recommendation ITU-T F.748.16 (2022), *Requirements for applications and services in smart manufacturing based on machine vision*. +- [b-ITU-T Y.101] Recommendation ITU-T Y.101 (2000), *Global Information Infrastructure terminology: Terms and definitions*. +- [b-CLIP] CLIP – Radford, Alec, et al., *Learning transferable visual models from natural language supervision*. International conference on machine learning. ICML. 2021. +- [b-IEEE\_Access] Zhang, Chuang, et al. *Weather visibility prediction based on multimodal fusion*. IEEE Access 7 (2019): 74776-74786. +- [b-IEEE\_ArXiv] Mees, Oier, Andreas Eitel, and Wolfram Burgard. *Choosing smartly: Adaptive multimodal fusion for object detection in changing environments*. 2019. <> +- [b-IEEE\_CVPR20] Bijelic, Mario, et al. *Seeing through fog without seeing fog: Deep multimodal sensor fusion in unseen adverse weather*. Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition. 2020. +- [b-ISO/IEC 11557] ISO/IEC 11557:1992, *Information technology – 3,81 mm wide magnetic tape cartridge for information interchange – Helical scan recording – DDS-DC format using 60 m and 90 m length tapes*. +- [b-Transformer] Ashish Vaswani, Noam Shazeer, Niki Parmar, Jakob Uszkoreit, Llion Jones, Aidan N. Gomez, Lukasz Kaiser, Illia Polosukhin: *Attention is All you Need*. NIPS 2017: 5998-6008. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects 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systems** + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +# ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.747.15 + +# Requirements of event-based vision systems + +## Summary + +With the advantages of high time-domain resolution, less data redundancy, low power consumption, and high dynamic range, the event-based vision system (EV-SYS) can be used in power consumption sensitive, high-speed movement and extreme lighting scenarios, such as high-speed industrial detection, autonomous driving, video surveillance, high-speed imaging and robot vision. Since the EV-SYS has differences in signal acquisition, coding, transmission, analysis and application compared to traditional camera-based intelligent vision due to the asynchronous output, the traditional vision algorithms cannot be applied. None of the existing machine vision standards has developed based on EV-SYS. The EV-SYS will be used in high-speed motion scenarios beyond the existing standards. Recommendation ITU-T F.747.15 provides the related requirements and reference use cases for EV-SYS. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.747.15 | 2024-06-13 | 16 | 11.1002/1000/15909 | + +## Keywords + +Event-based vision sensor, event-based vision system, requirements. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2024 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-----------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 2 | +| 6 Overview of event-based vision system ..... | 2 | +| 6.1 Introduction of event-based vision sensor and system ..... | 2 | +| 7 Requirements of event-based vision system..... | 3 | +| 7.1 Data acquisition ..... | 3 | +| 7.2 Data coding..... | 4 | +| 7.3 Data transmission ..... | 4 | +| 7.4 Data analysis..... | 4 | +| Appendix I – Use cases of event-based vision system..... | 6 | +| I.1 Use case of industrial quality inspection ..... | 6 | +| I.2 Use case of autonomous driving..... | 6 | +| I.3 Use case of video surveillance ..... | 6 | +| I.4 Use case of robotic vision..... | 7 | +| Appendix II – Event-based vision sensor (EVS)/Event camera (EC) ..... | 8 | +| Bibliography..... | 11 | + + + +# Requirements of event-based vision systems + +# 1 Scope + +This Recommendation specifies the requirements and use cases of event-based vision systems in order to complement the developments of common requirements and framework of intelligent vision systems. The requirements of the event-based vision system are independent of any specific application. + +The scope of this Recommendation includes: + +- The definition of event-based vision system. +- Requirements of event-based vision system. + +Use cases of the event-based vision are provided in Appendix I. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following term defined elsewhere: + +**3.1.1 application** [b-ITU-T Y.101]: A structured set of capabilities, which provide value-added functionality supported by one or more services. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following term: + +**3.2.1 event-based vision system**: A specialized system with structured capabilities designed to capture, process and interpret visual information through event-based vision sensor. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-------|----------------------------------------| +| AER | Address-Event-Representation | +| ATIS | Asynchronous Time-based Image Sensor | +| DAVIS | Dynamic and Active Pixel Vision Sensor | +| DSP | Digital Signal Processor | +| DVS | Dynamic Vision Sensor | + +| | | +|--------|---------------------------| +| EC | Event Camera | +| EVS | Event-based Vision Sensor | +| EV-SYS | Event-based Vision System | + +## 5 Conventions + +In this Recommendation: + +- The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. +- The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +# 6 Overview of event-based vision system + +Event-based vision system (EV-SYS) is a visual system that uses event-based vision sensor (EVS) for perception and introduces a specific algorithm for processing. It has the potential of detecting and tracking objects with high-speed movement and extreme lighting. + +Event-based vision sensor (EVS), also known as event camera (EC), are essential devices in EV-SYS. They capture information from the physical scene and output "events" for further processing by subsequent devices. The processing unit focuses on coding/decoding, extracting visual features, perception fusion, etc. + +## 6.1 Introduction of event-based vision sensor and system + +The event-based vision system (EV-SYS) is inspired by the biological visual system and aims to simulate or surpass human visual ability: such as efficient adaptive processing of dynamic and static information, small sample generalization ability and comprehensive complex scene perception ability. + +It comprises two parts: perception and processing. In the perception part, event cameras, which may cooperate with frame-based cameras, collect information from the external environment and pass down event data to the pre-processing part. The processing part focuses on extracting visual features from the raw event data, comprising algorithms and the hardware and datasets. + +If the EV-SYS is distributed in the edge and cloud, the event data are conveyed over the transmission network. The processor is divided into pre-processing and post-processing, which are distributed at both ends of the network. Each processor may include a compressed coder/decoder module. + +Figure 1 depicts the structure of EV-SYS, and Figure 2 the structure with requirements. + +![Figure 1: The structure of EV-SYS. The diagram is divided into two horizontal sections. The top section shows three main stages: Perception, Processing, and Application. Perception includes 'Event-based camera arrays' (Event-based camera 1, 2, 3, ...) and 'Frame-based camera arrays' (Frame-based camera 1, 2, ...). Processing includes 'Hardware' (GPU, ...), 'Datasets' (DVS-Gesture, DVS-Stereo, ...), and 'Algorithms' (HOTS, SNN, ...). Application lists Automotive, Robotics, AR/VR, Space, Inspection, Surveillance, Star tracking, and ... . The bottom section shows a linear flow: Physical scene -> Perception (Camera arrays: Event-based cameras, Frame-based cameras) -> Pre-processing (Feature extractor -> Encoder) -> Network (Transmission) -> Post-processing (Decoder -> Perception fusion, ...) -> Application. A label F.747.15(24) is at the bottom right.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +Figure 1: The structure of EV-SYS. The diagram is divided into two horizontal sections. The top section shows three main stages: Perception, Processing, and Application. Perception includes 'Event-based camera arrays' (Event-based camera 1, 2, 3, ...) and 'Frame-based camera arrays' (Frame-based camera 1, 2, ...). Processing includes 'Hardware' (GPU, ...), 'Datasets' (DVS-Gesture, DVS-Stereo, ...), and 'Algorithms' (HOTS, SNN, ...). Application lists Automotive, Robotics, AR/VR, Space, Inspection, Surveillance, Star tracking, and ... . The bottom section shows a linear flow: Physical scene -> Perception (Camera arrays: Event-based cameras, Frame-based cameras) -> Pre-processing (Feature extractor -> Encoder) -> Network (Transmission) -> Post-processing (Decoder -> Perception fusion, ...) -> Application. A label F.747.15(24) is at the bottom right. + +**Figure 1 – The structure of EV-SYS** + +![Figure 2: The structure of EV-SYS with requirements. This is a linear flow diagram: Physical scene -> Perception -> Processing -> Network -> Post-processing -> Application. Above the boxes are labels: 'Data acquisition' above Perception, 'Data coding' above Processing, 'Data transmission' above Network, and 'Data analysis' above Post-processing. A label F.747.15(24) is at the bottom right.](562f471e8153729557e6a4ee6343c32c_img.jpg) + +Figure 2: The structure of EV-SYS with requirements. This is a linear flow diagram: Physical scene -> Perception -> Processing -> Network -> Post-processing -> Application. Above the boxes are labels: 'Data acquisition' above Perception, 'Data coding' above Processing, 'Data transmission' above Network, and 'Data analysis' above Post-processing. A label F.747.15(24) is at the bottom right. + +**Figure 2 – The structure of EV-SYS with requirements** + +# 7 Requirements of event-based vision system + +## 7.1 Data acquisition + +The data acquisition of EV-SYS should support a variety of event-based vision sensor (EVSs) such as dynamic vision sensor (DVS), asynchronous time-based image sensor (ATIS), dynamic and active pixel vision sensor (DAVIS), and Vidar and it should work in cooperation with traditional frame-based vision sensors. The data acquisition requirements are outlined as follows: + +DA-01: It is required to support the spatial and temporal resolution required by EVS to ensure precise and accurate data capture. + +DA-02: It is required to support the high dynamic range of EVS, ensuring the accurate capture of data under varying lighting conditions. + +DA-03: It is required to support the asynchronous characteristics of EVS, ensuring effective management and processing of event-based data streams. + +DA-04: It is recommended to support calibration and alignment mechanisms to compensate for sensor-specific variations, such as spatial and temporal disparities, ensuring data consistency and accuracy. + +DA-05: It is recommended to support redundancy and error-checking mechanisms to guarantee data integrity during the transmission and storage processes. + +DA-06: It is recommended to support sensor parameter adjustments and settings optimization, such as sensitivity and event threshold levels, to enhance adaptability to different scenarios. + +## 7.2 Data coding + +The data coding of EV-SYS should accommodate the high demands for transmission and storage imposed by EVS. The data coding requirements are as follows: + +DC-01: It is required to support the high-speed and asynchronous characteristics of EVS data streams. + +DC-02: It is required to use the widely adopted open data coding standards, such as those compliant with international image and video compression standards, to promote compatibility within EV-SYS. + +DC-03: It is recommended to support the compression mechanisms to reduce the overall data volume, optimizing storage and transmission efficiency while preserving critical information. + +DC-04: It is recommended to use low-latency coding to ensure real-time or near-real-time processing, which is crucial for applications like autonomous driving and robotics. + +DC-05: It is recommended to include error detection and correction mechanisms to enhance data integrity. + +DC-06: It is recommended to support both lossless and lossy data encoding options, allowing trade-offs between data fidelity and data transmission/storage efficiency in specific scenarios. + +## 7.3 Data transmission + +The data transmission of EV-SYS should support two cases: asynchronous sparse data and dense data streams. It should be robust, efficient and adaptable to different data types and applications. The data transmission requirements are outlined as follows: + +DT-01: It is required to support efficient transmission of asynchronous sparse data and adapt to the sporadic and event-driven nature of EVS output. + +DT-02: It is recommended to provide data priority and efficient processing mechanisms for dense data stream scenarios to prevent bottlenecks and data loss during the transmission process. + +DT-03: It is recommended to support low latency, especially in applications with real-time or near-real-time processing. + +DT-04: It is recommended to support various communication protocols such as TCP/IP, HTTP, Bluetooth, etc. and interfaces to allow seamless integration with other components. + +DT-05: It is recommended to support error detection and correction mechanisms during data transmission to enhance data integrity and ensure reliable transmission. + +DT-06: It is recommended to provide data compression mechanisms during transmission, especially for dense data streams, to optimize bandwidth usage and reduce transmission overhead. + +DT-07: It is recommended to support data encryption and secure authentication mechanisms to protect data during transmission, especially in scenarios where data security is critical. + +DT-08: It is recommended to provide flexible data transmission modes to meet various application scenarios, such as allowing point-to-point and network communication options. + +## 7.4 Data analysis + +The data analysis of EV-SYS should support vision-related tasks, such as target detection, target recognition, target tracking, event recognition, navigation and positioning, visual scene reconstruction, 3D scene depth estimation, etc. The data analysis requirements are outlined as follows: + +DA-01: It is required to support event recognition to detect and interpret events in data. + +DA-02: It is recommended to support real-time or near real-time processing to ensure timely responses and actions based on analysed information. + +DA-03: It is recommended to support a high-speed target detection mechanism to quickly identify and locate objects within the scene even under challenging conditions. + +DA-04: It is recommended to support high-speed target recognition to ensure accurate and rapid recognition of objects within the field of view. + +DA-05: It is recommended to support high-speed target tracking, enabling continuous monitoring and prediction of target motion. + +DA-06: It is recommended to support navigation and positioning functions to provide location information. + +DA-07: It is recommended to support visual scene reconstruction and 3D scene depth estimation to provide comprehensive spatial information and enhance EV-SYS's understanding and analysis of the scene. + +## Appendix I + +### Use cases of event-based vision system + +(This appendix does not form an integral part of this Recommendation.) + +### I.1 Use case of industrial quality inspection + +#### I.1.1 High-speed embedded-object detection and recognition + +[b-IEEE-Electron] presents a system using neuromorphic dual-line vision sensor (i.e., DVS) for object recognition and classification. The embedded vision-sensor system consists of three printed circuit boards. A sensor board, a processor board and a digital signal processor (DSP) stamp board (core module) are stacked on top of each other. The sensor board holds a dual-line temporal-contrast vision sensor chip and auxiliary electronics. It serves as a motherboard for the DSP core module. The data-processing unit consists of a DSP used for data processing, transmission and system control, etc. + +#### I.1.2 Vibration monitoring + +EV-SYS can be used to monitor vibration frequencies with pixel precision, by tracking the temporal evolution of every pixel in a scene, and provides a global, continuous understanding of vibration patterns. + +### I.2 Use case of autonomous driving + +Autonomous driving is an advanced technology that relies on computer and artificial intelligence technology to achieve complete, safe and effective driving without human intervention. + +The autonomous vehicle senses the situation and its surrounding environment in real-time through sensors, then makes planning decisions through the intelligent system, and finally performs the driving operation through the control system. + +Vision sensor (frame-based camera) is an indispensable part of autonomous driving. However, there are still some limitations: a) the cameras are vulnerable to the mutation of light and reverse light; b) The cameras produce a large amount of data and require high computing power. + +The event camera has the advantages of low latency, low redundancy, low power consumption and high dynamics, which can help autonomous vehicles reduce the complexity of information processing, improve the safety of vehicles and work normally under extreme light conditions. + +[b-IEEE-21IJCNN] provides an example of using a DVS camera and the spiking neural network CarSNN, deployed in neuromorphic hardware, to do a "cars vs background" classification task. It shows acceptable performance with only 0.72 ms latency and 315 mW power consumption. + +[b-IEEE-ICME] proposes a joint framework combining event-based and frame-based vision for vehicle detection to overcome the high-speed motion blur and low dynamic range of frame-based cameras. The joint framework shows better performance than frame-based methods. + +### I.3 Use case of video surveillance + +The event camera can be used for special occasion monitoring tasks, as well as to upgrade and enhance existing monitoring system. + +The event camera only captures the movement status of characters and does not record facial features or clothing colours. It is very suitable for safety monitoring at medical or long-term care sites to protect personal privacy. + +Event cameras are highly dynamic and can monitor the movement of people in dim places where frame-based cameras are difficult to capture. Therefore, the integration of traditional cameras and event cameras can build a more secure monitoring system. In addition, in the unattended field, the invader can be dynamically detected in the low-light situation. + +### **I.4 Use case of robotic vision** + +[b-IEEE-20IJCNN] presents a gait imitation solution for a hexapod robot implemented using Spiking Neural Network and DVS. The student hexapod generates a sequence of leg motions identical to the expert's by watching the expert in real-time. The system can learn the gait within a short training period and consume ultra-low energy. + +## Appendix II + +### Event-based vision sensor (EVS)/Event camera (EC) + +(This appendix does not form an integral part of this Recommendation.) + +Event-based vision sensor (EVS), or event camera (EC) is a signal acquisition device, which can respond to light intensity changes in the scene asynchronously and independently for each pixel. An "event" of an EC is defined as the information output by the EC including pixel address, time-stamp and the polarity of light intensity changes. Each event represents a change of light intensity of predefined magnitude at a pixel at a particular time. It offers significant advantages over frame-based cameras, such as low redundancy, less power consumption, high dynamic range, no motion blur, and low latency in the order of microseconds. + +Generally, there are two types of EC according to the sampling models: differential typing (see Figure II.1) and integral typing (see Figure II.2). The differential typing vision sensor mostly adopt a log-difference model, that is, the photocurrent and voltage adopt a log-mapping relationship. As the relative change in light intensity causes voltage changes above the predefined threshold, the pixel generates a spiking signal. The integral typing vision sensor encode pixel light intensity as frequency or pulse intervals: the photoreceptor transforms light signals into electrical signals, and the integrator accumulates the intensity. When the intensity value exceeds the predefined threshold value, the pixel outputs a spiking signal, and the integrator will be reset to empty charge. + +![Figure II.1 – Differential typing sampling. The figure consists of two vertically aligned plots sharing a common time axis 't'. The top plot shows the logarithm of light intensity, V_log, over time. A curve represents the intensity, and a horizontal dashed line represents a threshold Θ_ev. The bottom plot shows the differential voltage, V_diff, over time. It displays 'ON spikes' (positive pulses) when the intensity increases above the threshold and 'OFF spikes' (negative pulses) when it decreases below the threshold. The label 'F.747.15(24)' is at the bottom right.](bafe3c344aef7f6f79dab49c9eca89a9_img.jpg) + +Figure II.1 – Differential typing sampling. The figure consists of two vertically aligned plots sharing a common time axis 't'. The top plot shows the logarithm of light intensity, V\_log, over time. A curve represents the intensity, and a horizontal dashed line represents a threshold Θ\_ev. The bottom plot shows the differential voltage, V\_diff, over time. It displays 'ON spikes' (positive pulses) when the intensity increases above the threshold and 'OFF spikes' (negative pulses) when it decreases below the threshold. The label 'F.747.15(24)' is at the bottom right. + +Figure II.1 – Differential typing sampling + +![Figure II.2 – Integral typing sampling. The figure consists of two vertically aligned plots sharing a common time axis 't'. The top plot shows the photocurrent, I_ph, over time, which follows a smooth curve representing the integrated light intensity. The bottom plot shows the pulse voltage, V_pulse, over time. It displays a series of rectangular pulses ('Spikes') whose frequency is proportional to the intensity I_ph. The label 'F.747.15(24)' is at the bottom right.](89dcb02be40d2949bb93de93bbf213d5_img.jpg) + +Figure II.2 – Integral typing sampling. The figure consists of two vertically aligned plots sharing a common time axis 't'. The top plot shows the photocurrent, I\_ph, over time, which follows a smooth curve representing the integrated light intensity. The bottom plot shows the pulse voltage, V\_pulse, over time. It displays a series of rectangular pulses ('Spikes') whose frequency is proportional to the intensity I\_ph. The label 'F.747.15(24)' is at the bottom right. + +Figure II.2 – Integral typing sampling + +The differential typing event-based vision sensor (EVS) can be roughly divided into three categories: Dynamic vision sensor (DVS), Asynchronous time-based image sensor (ATIS), and dynamic and active pixel vision sensor (DAVIS). + +The DVS consists of the photoreceptor, the dynamic detection circuit (differencing circuit) and the comparator output circuit (see Figure II.3). The DVS has independent asynchronous pixels that can individually respond to light intensity changes. The comparator output ON or OFF event based on whether the light intensity increases or decreases crossing a predefined threshold. + +![Figure II.3 – The structure of DVS. This is a block diagram showing the signal flow in a Dynamic Vision Sensor (DVS). It starts with 'Physical scene' on the left, which feeds into a 'Photoreceptor' block. This is followed by a 'Differencing circuit' block, then a 'Comparators' block, and finally an 'Event information' block on the right. The 'Photoreceptor', 'Differencing circuit', and 'Comparators' blocks are grouped together within a larger box labeled 'DVS'. The label 'F.747.15(24)' is at the bottom right.](704082cc3e11776bda29595c76411362_img.jpg) + +Figure II.3 – The structure of DVS. This is a block diagram showing the signal flow in a Dynamic Vision Sensor (DVS). It starts with 'Physical scene' on the left, which feeds into a 'Photoreceptor' block. This is followed by a 'Differencing circuit' block, then a 'Comparators' block, and finally an 'Event information' block on the right. The 'Photoreceptor', 'Differencing circuit', and 'Comparators' blocks are grouped together within a larger box labeled 'DVS'. The label 'F.747.15(24)' is at the bottom right. + +Figure II.3 – The structure of DVS + +ATIS provides certain gray information with event information. It includes two parts: event-based change detection and pulse-width-modulation (see Figure II.4). The event-based change detection part contains a complete DVS pixel structure to sense the light intensity change, and the pulse-width-modulation part adopts a time-based exposure method to calculate the time required for the voltage sides of the capacitor to drop from high level to low level. The gray value is decided according to the drop time, higher gray value if the drop time is shorter, and vice versa. + +![Figure II.4 – The structure of ATIS. The diagram shows a 'Physical scene' input branching into two parallel processing paths. The top path, labeled 'Charge detector', consists of a 'Photoreceptor', a 'Differencing circuit', and 'Comparators', leading to 'Event information'. The bottom path, labeled 'Photo measurement', consists of a 'Photoreceptor', a 'Capacitor', and 'Logic', leading to 'Grayscale information'. A small label 'F.747.15(24)' is in the bottom right corner.](bd0b93e7a46ede276d0a3b79ac487bd9_img.jpg) + +Figure II.4 – The structure of ATIS. The diagram shows a 'Physical scene' input branching into two parallel processing paths. The top path, labeled 'Charge detector', consists of a 'Photoreceptor', a 'Differencing circuit', and 'Comparators', leading to 'Event information'. The bottom path, labeled 'Photo measurement', consists of a 'Photoreceptor', a 'Capacitor', and 'Logic', leading to 'Grayscale information'. A small label 'F.747.15(24)' is in the bottom right corner. + +**Figure II.4 – The structure of ATIS** + +The DAVIS combines the DVS camera traditional camera with the traditional camera (advanced photo system camera). While the DVS detects the light intensity changes and outputs the asynchronous event flow information, the advanced photo system synchronously exposes to obtain the gray scale information of the scene. See Figure II.5. + +![Figure II.5 – The structure of DAVIS. The diagram shows a 'Physical scene' input entering a 'Photoreceptor'. From the 'Photoreceptor', one path goes to a 'Differencing circuit' and then to 'Comparators' (labeled 'DVS'), leading to 'Event information'. Another path from the 'Photoreceptor' goes to 'Transistors' and then to 'Caps' (labeled 'APS'), leading to 'Grayscale information'. A small label 'F.747.15(24)' is in the bottom right corner.](75f0cb39f1cd165dfe4a6aa6c4d9388d_img.jpg) + +Figure II.5 – The structure of DAVIS. The diagram shows a 'Physical scene' input entering a 'Photoreceptor'. From the 'Photoreceptor', one path goes to a 'Differencing circuit' and then to 'Comparators' (labeled 'DVS'), leading to 'Event information'. Another path from the 'Photoreceptor' goes to 'Transistors' and then to 'Caps' (labeled 'APS'), leading to 'Grayscale information'. A small label 'F.747.15(24)' is in the bottom right corner. + +**Figure II.5 – The structure of DAVIS** + +Vidar is a type of integral typing event-based vision sensor. The Vidar consists of a photoreceptor, an integrator and a comparator (see Figure II.6). The photoreceptor converts the optical signal into an electrical signal, the integrator integrates the electrical signal, the comparator compares the accumulated value with the predefined threshold to judge the output spiking signal, and the integrator is reset. + +![Figure II.6 – The structure of Vidar. The diagram shows a 'Physical scene' input entering a 'Photoreceptor', which is followed by an 'Integrator' and a 'Comparator' (labeled 'Vidar'), leading to 'Event and grayscale information'. A small label 'F.747.15(24)' is in the bottom right corner.](bffdddb47fced140f8d17fdc2a29f592_img.jpg) + +Figure II.6 – The structure of Vidar. The diagram shows a 'Physical scene' input entering a 'Photoreceptor', which is followed by an 'Integrator' and a 'Comparator' (labeled 'Vidar'), leading to 'Event and grayscale information'. A small label 'F.747.15(24)' is in the bottom right corner. + +**Figure II.6 – The structure of Vidar** + +The event camera (EC) adopts the address-event-representation (AER) protocol to transmit the event data, which reduces the number of signal paths by explicitly coding addresses and implicitly coding events. Figure II.7 shows an example of AER. + +![Diagram illustrating the Address-Event Representation (AER) protocol between a transmitting chip and a receiving chip.](5cab96b2d23174c25919840ecd50aa48_img.jpg) + +The diagram shows the process of Address-Event Representation (AER). On the left is a "Transmitting chip" containing a vertical array of four cells. An arrow labeled "Event" points to a starburst icon in the bottom cell. Signals from the cells pass through an "Address encode" block. A large horizontal arrow labeled "3413221" indicates the transmission of encoded data to the right. On the right is a "Receiving chip" with a similar vertical array of four cells. The data passes through an "Address decoder" block before reaching the cells. The bottom cell of the receiving chip also contains a starburst icon. Small vertical arrows within the chip structures indicate signal flow. The identifier "F.747.15(24)" is located at the bottom right of the diagram. + +Diagram illustrating the Address-Event Representation (AER) protocol between a transmitting chip and a receiving chip. + +**Figure II.7 – An example of AER** + +## Bibliography + +- [b-ITU-T Y.101] Recommendation ITU-T Y.101 (2000), *Global Information Infrastructure terminology: Terms and definitions*. +- [b-IEEE-20IJCNN] Ting J, Fang Y, Lele A, Raychowdhury A. (2020), *Bio-inspired gait imitation of hexapod robot using event-based vision sensor and spiking neural network*. In: Proceedings of the 2020 International Joint Conference on Neural Networks (IJCNN). Glasgow, UK: IEEE. 1-7. +- [b-IEEE-21IJCNN] A. Viale, A. Marchisio, M. Martina, G. Masera and M. Shafique (2021), *CarSNN: An Efficient Spiking Neural Network for Event-Based Autonomous Cars on the Loihi Neuromorphic Research Processor*, International Joint Conference on Neural Networks (IJCNN), Shenzhen, China, 2021, pp. 1-10, doi: 10.1109/IJCNN52387.2021.9533738. +- [b-IEEE-Electron] Belbachir A N, Hofstatter M, Litzenberger M, et al. (2011), *High-speed embedded-object analysis using a dual-line timed-address-event temporal-contrast vision sensor*. IEEE Transactions on Industrial Electronics, 58(3): 770-783. +- [b-IEEE-ICME] J. Li, S. Dong, Z. Yu, Y. Tian and T. Huang (2019), *Event-Based Vision Enhanced: A Joint Detection Framework in Autonomous Driving*, IEEE International Conference on Multimedia and Expo (ICME), Shanghai, China, 2019, pp. 1396-1401, doi: 10.1109/ICME.2019.00242. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and 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b/marked/F/T-REC-F.748.17-202212-I_PDF-E/raw.md @@ -0,0 +1,631 @@ + + +# Recommendation **ITU-T F.748.17 (12/2022)** + +SERIES F: Non-telephone telecommunication services + +Multimedia services + +--- + +## **Technical specification for artificial intelligence cloud platform – Artificial intelligence model development** + +![ITU logo](0538daaa5583c23e17db3a12f2281a55_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessages service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multdestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| MULTIMEDIA SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## Recommendation ITU-T F.748.17 + +# Technical specification for artificial intelligence cloud platform – Artificial intelligence model development + +## Summary + +Recommendation ITU-T F.748.17 provides a framework for the cloud-based development of artificial intelligence (AI) models. It covers the terminology, features, and reference design of an AI cloud platform to enable the development of AI models. It establishes the technical specifications of the platform's supporting functional modules, core functional modules, and auxiliary functional modules. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.748.17 | 2022-12-14 | 16 | 11.1002/1000/15194 | + +## Keywords + +Artificial intelligence, cloud platform, model development. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2023 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Overview ..... | 2 | +| 7 Supporting functional modules..... | 4 | +| 7.1 User management module ..... | 4 | +| 7.2 Image management module..... | 4 | +| 7.3 Resource management module..... | 4 | +| 7.4 Storage service module..... | 5 | +| 7.5 Container service module ..... | 5 | +| 7.6 Log service module ..... | 5 | +| 8 Core functional modules..... | 6 | +| 8.1 Data management module ..... | 6 | +| 8.2 Algorithm development module..... | 7 | +| 8.3 Model training module ..... | 7 | +| 8.4 Model management module ..... | 8 | +| 9 Auxiliary functional modules ..... | 8 | +| 9.1 Visualization module..... | 8 | +| 9.2 Model deployment module..... | 9 | +| 9.3 Automated machine learning module..... | 9 | +| Appendix I – Deployment of the AI cloud platform..... | 10 | +| I.1 Deployment architecture overview..... | 10 | +| I.2 Prerequisites and dependencies ..... | 11 | +| I.3 Cluster deployment..... | 12 | +| I.4 Microservices deployment..... | 12 | +| I.5 System verification..... | 12 | +| Bibliography..... | 13 | + + + +# Technical specification for artificial intelligence cloud platform – AI model development + +# 1 Scope + +This Recommendation gives a reference architecture and functional requirements for artificial intelligence (AI) model development in an AI cloud platform. + +In particular, the scope of this Recommendation includes: + +- A reference architecture for the AI model development framework in an AI cloud platform; +- The descriptions of the modules that should be included in an AI cloud platform to facilitate AI model development; and +- The minimum and recommended functional requirements for AI model development that an AI cloud platform should satisfy. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T Y.3531] Recommendation ITU-T Y.3531 (2020), *Cloud computing – Functional requirements for machine learning as a service*. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 artificial intelligence (AI)** [b-ISO/IEC 2382]: An interdisciplinary field, usually regarded as a branch of computer science, dealing with models and systems for the performance of functions generally associated with human intelligence, such as reasoning and learning. + +**3.1.2 algorithm** [b-ISO/IEC 11557]: A set of rules for transforming the logical representation of data. + +**3.1.3 container** [b-ITU-T Y.3535]: A set of software to provide isolation, resource control, and portability for the virtualization processing of an application. + +NOTE 1 – A container runs on the kernel in a bare-metal machine or virtual machine. + +NOTE 2 – "Application" implies business logic including a required library or binary to run in a container. + +**3.1.4 dataset** [b-ISO 19115-1]: Identifiable collection of data. + +**3.1.5 model** [b-ITU-T F.748.16]: An output created by an algorithm running on training data that can generate an inference or prediction, based on the input data. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 automated machine learning:** The process of automating the time consuming, iterative tasks of machine learning model development. It allows developers to build machine learning models automatically with high scale, efficiency, and productivity all while sustaining model quality. + +**3.2.2 built-in:** Indicating that an object is provided by the platform. + +**3.2.3 customized:** Indicating that an object is created or uploaded by the user. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|--------|------------------------------------| +| AI | Artificial Intelligence | +| AutoML | Automated Machine Learning | +| CPU | Central Processing Unit | +| GPU | Graphics Processing Unit | +| HPO | Hyper-Parameter Optimization | +| IDE | Integrated Development Environment | +| NAS | Neural Architecture Search | +| NPU | Neural-Network Processing Unit | +| VM | Virtual Machine | + +# 5 Conventions + +In this Recommendation: + +- The keywords "**is required to**" indicate a requirement that must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. +- The keywords "**is recommend to**" indicate a requirement that is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. +- The keywords "**optional**" indicate an optional requirement that is permissible, without implying any sense of being recommended. These terms are not intended to imply that the vendor's implementation must provide the option and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the specification. + +# 6 Overview + +In essence, the artificial intelligence (AI) model is a function, and instead of relying on a logic inference or induction, the parameters of this function are obtained through training. The goal of the AI model development process is to fit the model structure and the parameters closer to the objective function by algorithm design and model training. + +An AI cloud platform integrates the necessary modules for data management, algorithm development, model training and model deployment, to meet the full life cycle requirements of the AI model development and production in a single cloud platform. The AI cloud platform's deployment guidelines are detailed in Appendix I. Figure 6-1 illustrates a recommended AI model development framework in an AI cloud platform. + +![Figure 6-1 – AI model development framework diagram showing three layers: Auxiliary functional modules, Core functional modules, and Supporting functional modules.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +The diagram illustrates the AI model development framework, organized into three horizontal layers: + +- Auxiliary functional modules (Top Layer):** Contains three modules: "Automated machine learning module", "Visualization module", and "Model deployment module". +- Core functional modules (Middle Layer):** Contains four modules: "Data management module", "Algorithm development module", "Model training module", and "Model management module". The flow is: "Data supplier" → "Data management module" → "Algorithm development module" → "Model training module" → "Model management module". There are bidirectional arrows between "Algorithm development module" and "Model training module" labeled "Release" and "Update". +- Supporting functional modules (Bottom Layer):** Contains six modules arranged in a 2x3 grid: "User management module", "Image management module", "Resource management module" (top row); "Container service module", "Storage service module", "Log service module" (bottom row). + +Interactions and connections: + +- An upward arrow points from the "Supporting functional modules" layer to the "Core functional modules" layer. +- From the "Automated machine learning module" to the "Algorithm development module", there are two arrows labeled "NAS" and "HPO". +- From the "Model training module" to the "Visualization module", there is an upward arrow. +- From the "Model management module" to the "Model deployment module", there is an upward arrow labeled "Release". + +F.748.17(22) + +Figure 6-1 – AI model development framework diagram showing three layers: Auxiliary functional modules, Core functional modules, and Supporting functional modules. + +**Figure 6-1 – AI model development framework** + +The framework given here is a description of the essential operations of an AI cloud platform for AI model development. The supporting functional modules on the bottom layer make up the AI cloud platform's infrastructure and enable the platform's fundamental operation, maintenance, resource management and scheduling, etc. The core functional modules depicted on the middle layer run through the entire AI model development process, including data management, algorithm development, model training and model deployment. The auxiliary functional modules are displayed on the top layer, which enhances the AI cloud platform's functionality for AI model development. + +The supporting functional modules and the core functional modules are mandatory, the auxiliary functional modules are optional. + +Typically, an AI cloud platform includes but is not limited to the following modules: + +- **User management module:** This module is to manage the user information. +- **Image management module:** This module is to manage the images for development, training and inference. +- **Resource management module:** This module is to manage the computing resources. +- **Container service module:** This module is to manage the containers for providing the execution environment. +- **Storage service module:** This module is to manage the storage resources. +- **Log service module:** This module is to manage the log service. +- **Data management module:** This module is to process and manage the datasets. +- **Algorithm development module:** This module is to support the development of algorithms. +- **Model training module:** This module is to manage the training procedure. +- **Model management module:** This module is to support the model management and the version control functions. +- **Visualization module:** This module is to support the visualization of data, parameters and other useful information generated during training. +- **Model deployment module:** This module is to manage the deployment of the model serving on cloud or devices. + +- **Automated machine learning (AutoML) module:** This module is to integrate the automated machine learning algorithms. + +# 7 Supporting functional modules + +### 7.1 User management module + +The user management module allows a unified user identity authentication as well as a user authentication management. + +The user refers to every authorized system user. Different users can manage resources with varying permissions. There are mainly three types of users an administrator, group user and a common user. In general, the administrators have access to all resources but common users only have access to a limited wealth of resources. The group users that belong to the same user group share the same permissions to the assigned resources. + +Its basic functions include but are not limited to: + +- **User registration and login:** It provides support for identity representation and authentication of users. +- **User authentication:** User authentication is the identification of user identities and permissions, which helps to avoid risk problems caused by a lack of permission management or inappropriate operation. + +### 7.2 Image management module + +The image management module is intended to manage the images for training and inference. + +The platform is recommended to provide a wealth of frequently used built-in images that are compatible with popular AI frameworks. If these built-in images cannot meet the requirements of some users, the platform is recommended to allow the users to create or upload customized images. + +The functional requirements of this module include but are not limited to: + +- **Image packing:** It is recommended to support packing the environment of the container directly as an image. +- **Version control:** It is recommended to support pulling images from and pushing images to the image repository. +- **Image management:** The recommended management operations include but are not limited to creating, deleting, updating, retrieving, etc. + +### 7.3 Resource management module + +The resource management module facilitates the management and scheduling of computing resources, as well as provides basic support for a variety of task scenarios. The resource type typically contains the central processing unit (CPU), graphics processing unit (GPU), neural-network processing unit (NPU), etc. The functional requirements of this module include but are not limited to: + +- **Resource specification:** It is recommended to support the customization of computing resources for various tasks. Users can configure the resource type, the number of nodes, and the node parameters. The number of nodes can only be set to a number between one and the cluster's maximum node count. The node specification specifies the number of CPU cores, GPU cards, and the memory available to customers for each node. A node's resource utilization cannot exceed the physical node's resource limit. + +- **Resource monitoring:** It is recommended to support the real-time monitoring of resource usage during execution. Monitoring indicators include but are not limited to CPU usage, GPU usage, video memory usage, temperature, etc. +- **Resource management:** The recommended management operations include but are not limited to creating, deleting, updating, retrieving, etc. + +### 7.4 Storage service module + +The storage service module shall provide diverse configurations of data, as well as the management and scheduling of those resources. + +There are mainly three types of storage services: block storage system, file storage system and object storage system. + +- **Block storage:** It is suitable for client use. It is recommended to support containers, virtual machines (VM), remote mounts, disk storage allocation, log storage, and other common use cases. +- **Object storage:** It is ideal for maintaining data that does not alter frequently. It does not support directory structure or file manipulations. Image storage, video storage, files, software install packages, and archival data are all common usage cases. +- **File storage:** It is suitable for multi-client data with a directory structure. + +The functional requirements of this module include but are not limited to: + +- **Storage allocation:** It is recommended to allocate storage space for all programs and data via different tasks. +- **Storage sharing:** It is recommended to tackle the requirement where numerous processes share the same storage space. +- **Storage management:** The recommended management operations include but are not limited to creating, deleting, updating, retrieving, etc. + +### 7.5 Container service module + +The container service module is required to provide an execution environment for each task. + +The functional requirements of this module include but are not limited to: + +- **Container orchestration:** The module is required to automate the deployment, management, scaling, and networking of containers. +- **Container lifecycle management:** The module is required to manage the lifecycle of containers. +- **Container management:** The recommended management operations include but are not limited to creating, deleting, updating, retrieving, etc. + +### 7.6 Log service module + +The log service module keeps track of the actions of each platform's essential task, which helps with timely detection, risk mitigation, and operational accident avoidance. + +The log types typically contain system log, task log, user log, etc. + +The functional requirements of this module include but are not limited to: + +- **Log collection and storage:** The module is recommended to support log collection and storage for a variety of tasks, such as data management, algorithm development, model training, model deployment, etc. +- **Log management:** The module is recommended to support basic operations of the log, including but not limited to log querying, filtering, downloading, backing up, etc. + +# 8 Core functional modules + +### 8.1 Data management module + +Data is the basis of an AI model development. The data management module is intended to transform the input data into a format that is suitable for AI model development. Figure 8-1 illustrates a recommended data management workflow. The dataset initialization, data import, and dataset release are required modules, and the data pre-processing and data labelling are optional modules. + +![Figure 8-1 – Data management framework flowchart](27b06ec9f42b5d727a2630f61a5f1861_img.jpg) + +``` +graph LR; A[Dataset initialization] --> B[Data import]; B --> C[Data pre-processing]; C --> D[Data labelling]; D --> E[Dataset release]; E --> F[(Dataset)]; F --> G[Training/inference]; B <--> H((Built-in dataset)); B <--> I((Local data)); D <--> J((Manual labelling/auto labelling)); +``` + +The diagram illustrates the data management framework. It starts with 'Dataset initialization' leading to 'Data import'. 'Data import' is influenced by 'Built-in dataset' and 'Local data'. From 'Data import', the flow proceeds to 'Data pre-processing', then 'Data labelling' (influenced by 'Manual labelling/auto labelling'), then 'Dataset release', and finally to a 'Dataset' icon which leads to 'Training/inference'. + +Figure 8-1 – Data management framework flowchart + +F.748.17(22) + +Figure 8-1 – Data management framework + +#### 8.1.1 Dataset initialization + +Dataset initialization is the foundation of data management and processing. The platform is recommended to enable the user to initialize a new dataset by specifying the metadata such as the dataset name, data type, labelling type, etc. The users can conduct management operations such as deleting, updating and retrieving the newly created dataset. + +#### 8.1.2 Data import + +The platform is recommended to support the import of massive structured, semi-structured, and unstructured data into a certain dataset. + +The data types include local data and built-in datasets. These data can be labelled or unlabelled. + +Import modes include single upload and batch upload. The platform is optional to provide an interface to monitor the progress of the data import process. + +#### 8.1.3 Data pre-processing + +The platform is optional to provide data quality enhancement services such as data cleaning, data verification, and data filtering. + +For labelled data, the platform is optional to provide data augmentation algorithms to increase the effective data size and promote the diversity of training samples. The algorithms include but are not limited to cropping, flipping, scaling, rotation, histogram equalization, contrast enhancement, and so on. + +#### 8.1.4 Data labelling + +The quality of labelling significantly affects the model performance. The platform is optional to provide labelling tools to enable the users to label the imported data. + +The platform is recommended to enable the users to perform labelling tasks for multiple purposes, including but not limited to the following: + +- **Image:** image classification, object detection, image segmentation. +- **Video:** target tracking, semantic segmentation, video classification. +- **Audio:** sound classification, speech recognition, voiceprint recognition. +- **Text:** text classification, named entity recognition, sequence to sequence, word segmentation. + +The specific functional requirements include but are not limited to: + +- **Manual labelling:** The platform is recommended to enable the users to manually label data. Besides, the platform is optional to support team labelling to maximize labelling efficiency. The users can perform crowdsourcing labelling for a large amount of data. +- **Automatic labelling:** Automatic labelling is intended to reduce the cost of manual labelling. The platform is recommended to enable the users to use the built-in algorithms to automatically generate labels or train a specific model to label the dataset. +- **Labels management:** The platform is recommended to enable the users to manage the annotations, such as viewing, confirming, modifying, removing, relabelling, etc. + +#### 8.1.5 Dataset release + +Prior to a dataset being used for training or inference, it is required to be released. The platform is required to support the release of datasets and the management of dataset versions. + +The platform is recommended to support the user in releasing various versions of the same dataset labelled at different times. The supported version management operations include but are not limited to viewing versions' detailed information, adjusting the current version and deleting versions. + +### 8.2 Algorithm development module + +This module is intended to develop AI algorithms based on the prepared dataset, image and resource. In an AI cloud platform, a user develops and debugs an algorithm in a docker. + +The platform is recommended to support customized algorithms and built-in algorithms: + +- **Customized algorithms:** The platform is required to enable the users to design and customize algorithms with the development tools. +- **Built-in algorithms:** The platform is recommended to provide a repository of built-in algorithms for various use cases, such as computer vision, natural language processing, recommendation, reinforcement learning, etc. These built-in algorithms can be edited or directly used for training to improve the efficiency of the algorithm development. + +The functional requirements for this module are outlined below. + +#### 8.2.1 Development tools + +The platform is recommended to provide users with online interactive development and debugging environments such as notebooks and drag-and-drop tools. Meanwhile, it is recommended to support the usage of local integrated development environment (IDE) for remote algorithm development. The users can edit, compile, and debug the code with a variety of development tools that support remote development. + +#### 8.2.2 Algorithm management + +The platform is recommended to support algorithm management operations, including but not limited to creating, deleting, updating, retrieving, downloading, forking, and releasing for training. + +### 8.3 Model training module + +This module is intended to support the training procedure of AI algorithms with the prepared dataset, image, resource and algorithm. The functional requirements for this module are outlined below, which can be referred from [ITU-T Y.3531]. + +#### 8.3.1 Parameters customization + +The platform is required to allow the users to customize the meta parameters, model parameters, and resource parameters when creating a new training task. The parameters include but are not limited to: + +- **Meta parameters:** task name, algorithms type, target algorithm, image, dataset, output path, etc. +- **Model parameters:** learning rate, iteration, epoch, batch-size, etc. +- **Resource parameters:** number of nodes, resource type, node specification, etc. + +#### 8.3.2 Model training + +The platform is recommended to support distributed training. The users can train the models on multiple cores (CPU / GPU / NPU / etc.) or multiple devices within a cluster or across multiple clusters. + +The platform is recommended to allow the users to restart training tasks from a certain checkpoint. + +The platform is recommended to support resource monitoring and log management, which refers to clause 7. + +#### 8.3.3 Model saving + +The platform is required to allow the users to save the output models to the model management module. + +#### 8.3.4 Task management + +The platform is recommended to support basic task management operations, including but not limited to creating, deleting, updating, retrieving, visualization, starting, stopping, and viewing detailed information. + +The platform is recommended to support training task version management. The users can tune the parameters based on the training result to generate a new version of the task. By comparing the performance of the output models, the most satisfactory model can be determined. + +### 8.4 Model management module + +This module is intended to manage the trained models in a unified manner. The functional requirements for this module are outlined below. + +#### 8.4.1 Model import + +The platform is required to allow the users to import models from the training module or upload local models. + +#### 8.4.2 Format management + +The platform is recommended to support common standard formats such as, .onnx, .pb, .pt, etc. + +The platform is recommended to support converting the models to the required formats to deploy them on different devices. + +#### 8.4.3 Model version management + +The platform is recommended to support model version management. In multiple training tasks, an algorithm generates numerous versions of a model. The supported model version management operations include but are not limited to creating, deleting, updating, retrieving, downloading, etc. + +## 9 Auxiliary functional modules + +### 9.1 Visualization module + +This optional module is intended to support the visualization of model, data, and parameters throughout the training procedure and provide an intuitive reference for AI model training and tuning. + +The platform is optional to support various visualization contents, including but not limited to: + +- **Model structure:** an interface to visualize the computation graph and model structure graph. +- **Scalar data:** an interface to visualize the scalar data generated throughout the training procedure. +- **Media data:** an interface to visualize media data, such as images, text, video, audio, etc. +- **Hyper-parameter:** an interface to visualize the hyper-parameter of the models. +- **Customized data:** an interface to visualize a customized combination of data. +- **Data statistical analysis:** an interface to visualize the statistical information of data generated throughout the training procedure. +- **Data embedding projection:** an interface to visualize the embedding projection of high dimensional data. +- **Data exception detection:** an interface to visualize the exception point of data. + +### 9.2 Model deployment module + +This optional module is intended to deploy the models on cloud, server, edge, and end devices for model inference. The users need to prepare the model, dataset, image and inference script, and convert the model to the required format before deploying a model. + +#### 9.2.1 Cloud deployment + +For deployment on cloud, the platform is recommended to support both online serving and batch inference. The term online serving refers to the process of packing the model inference as a web service that can be called via HTTP, gRPC, etc. The term batch inference refers to the process of performing inference on a batch of data. + +Similar to the model training module, the platform is recommended to support task management, the users can create, delete, update, retrieve, start, terminate deployment tasks, and view task detailed information. + +The platform is optional to support resource monitoring and logs generating / presenting / downloading, which refers to clause 7. + +#### 9.2.2 End device deployment + +For deployment on end devices, the platform is optional to support encapsulating models as SDK programs that can run offline on end devices. + +### 9.3 Automated machine learning module + +This optional module is intended to automate critical model development activities such as model design, hyper-parameter tuning and model training. + +Hyper-parameter optimization (HPO) and neural architecture search (NAS) are recommended components of an automated machine learning (AutoML). + +- **HPO:** a module uses certain strategies to optimize the hyper-parameters of AI models automatically, such as learning rate, batch size and weight decay. +- **NAS:** a module automatically designs the neural network architecture of the AI model by searching and optimizing the structure from a certain search space. + +The platform is optional to provide a repository of built-in search strategies and support uploading customized search strategies. + +The platform is optional to support the users to perform management operations on AutoML tasks, including but not limited to creating, stopping, deleting, modifying, retrieving, etc. + +## Appendix I + +### Deployment of the AI cloud platform + +(This appendix does not form an integral part of this Recommendation.) + +Platform deployment includes all the actions that make the AI cloud platform available for AI model development. The correct deployment of the AI cloud platform is required to ensure the platform's normal functionality. The deployment process consists of a set of interconnected actions that are tailored to the demands or features of each individual. + +In this appendix, a guide for the AI cloud platform's deployment is introduced. + +### I.1 Deployment architecture overview + +Majority of cloud platforms in literature employ microservice architecture, which is an architectural approach that structures an application as a collection of loosely connected and independently deployable services. The microservice design provides high flexibility, scalability and availability. + +Figure I.1 depicts a recommended schematic deployment design for an AI cloud platform based on microservices. + +![Deployment architecture diagram showing five layers: Display layer, Gateway, Application service layer, Storage layer, and Infrastructure layer.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg) + +The diagram illustrates the deployment architecture of an AI cloud platform, organized into five horizontal layers: + +- Display layer:** Contains various user devices including a desktop monitor, laptop, tablet, smartphone, and other unspecified devices. +- Gateway:** A single component represented by an orange icon, acting as an intermediary between the display layer and the application service layer. +- Application service layer:** Contains seven microservices, each represented by a blue hexagon icon: Data management, Algorithm management, Training management, Model management, Online serving, Web frontEnd, and Image management. +- Storage layer:** Divided into three sections: Database (with two green cylinder icons), Distributed cache (with two blue cylinder icons), and File storage (with two green cloud-like icons). +- Infrastructure layer:** Contains a cluster of nodes: + - Worker nodes:** Four red server icons labeled "Node". + - Service nodes:** Two orange server icons with cloud symbols. + - Master nodes:** Two blue server icons labeled "Master". + - Storage nodes:** Two orange server icons with cloud symbols. + +Deployment architecture diagram showing five layers: Display layer, Gateway, Application service layer, Storage layer, and Infrastructure layer. + +F.748.17(22) + +**Figure I.1 – Deployment architecture** + +### I.2 Prerequisites and dependencies + +For the correct deployment of the AI cloud platform, certain dependencies shall be prepared as follows on demand. There are a variety of dependencies, including but not limited to: + +- **Container service:** The container service gives applications a uniform packaging environment in which to run. +- **Image registry service:** The image registry service provides image life cycle services. +- **Cluster management tool:** The cluster management tool is used to manage containerized applications across several hosts in the cloud platform and provide a framework for application deployment, planning, update and maintenance. +- **Database management system:** The database management system provides a data warehouse, which stores data in a specific format. The warehouse allows users to add, query, update and delete data. +- **Storage system:** The storage system is used to store user data, share files, backup data, etc. +- **Version control system:** The version control system is used for data backup and version control. + +- **Front-end development kit:** The front-end development kit ensures the normal operation of front-end services. +- **Back-end development kit:** The back-end development kit ensures the normal operation of back-end services. +- **Web and reverse proxy servers:** The web and reverse proxy servers provide routing, reverse proxy, logging, permission management, and other functions. + +### I.3 Cluster deployment + +Generally, a cluster consists of four types of nodes: + +- **Master nodes:** The master nodes form a control plane that coordinates the cluster. +- **Worker nodes:** The worker nodes undertake workloads. +- **Storage nodes:** The storage nodes provide a distributed file storage system. +- **Service nodes:** One or multiple service nodes run applications as microservices. + +It meets the following conditions: + +- Every machine meets the minimum requirements for the assigned type of node. +- Full network connectivity is available between all the machines in the cluster (public or private network). + +To use GPUs in this cluster, follow the official manual to install the necessary plugins and drivers. + +### I.4 Microservices deployment + +Before deployment, the microservice architectural pattern should be used to structure the system as a collection of services. Each module, including basic fundamental modules, functional modules, and optional modules, should be separated into a microservice. + +The following are a few different microservice deployment patterns: + +- **Multiple service instances per host:** It is a pattern in which a single host runs several instances of different services (physical or virtual machine). +- **Single service instance per host:** It is a pattern in which each single service instance is deployed on its host. +- **Service instance per virtual machine:** It is a pattern in which the service is packaged as a virtual machine image and deployed as a separate virtual machine. +- **Service instance per container:** It is a pattern in which the service is packaged as a container image and deployed as a container. +- **Serverless deployment:** It is a pattern in which physical or virtual hosts, or containers, are deployed using a deployment infrastructure that hides any concept of servers. + +### I.5 System verification + +The user may verify the deployment of the system through a simple workflow. + +- **Verification of cluster status:** This step is to verify that the cluster is successfully deployed by launching an application to check the state of the cluster. +- **Verification of microservices status:** This step is to check that each microservice is installed and configured correctly. +- **Verification of module functionality:** This step is to ensure each module is available. The user needs to select a minimum collection of test data, including an image, a dataset, and an algorithm to train the model on the platform. + +# Bibliography + +- [b-ITU-T F.748.16] Recommendation ITU-T F.748.16 (2022), *Requirements for applications and services in smart manufacturing based on machine vision.* +- [b-ITU-T Y.3535] Recommendation ITU-T Y.3535 (2022), *Cloud computing - Functional requirements for a container.* +- [b-ISO/IEC 2382] ISO/IEC 2382:2015, *Information technology – Vocabulary.* +<> +- [b-ISO/IEC 11557] ISO/IEC 11557:1992, *Information technology – 3,81 mm wide magnetic tape cartridge for information interchange – Helical scan recording – DDS-DC format using 60 m and 90 m length tapes.* +<> +- [b-ISO 19115-1] ISO 19115-1:2014, *Geographic information – Metadata – Part 1: Fundamentals.* +<> + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.748.18-202212-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg b/marked/F/T-REC-F.748.18-202212-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..08aecbe120cf3e69dbda66655076275504e4585c --- /dev/null +++ b/marked/F/T-REC-F.748.18-202212-I_PDF-E/042733dc5e8e7f5f30b60adba3266cde_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ebacb74b5271d0ab8f3f68d4da5c7d372cc9b29910defa9efe69d7f238aeda7b +size 43464 diff --git a/marked/F/T-REC-F.748.18-202212-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg b/marked/F/T-REC-F.748.18-202212-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d4d8969f805414689ab79cfd08c333d454d482b3 --- /dev/null +++ b/marked/F/T-REC-F.748.18-202212-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:636c3839edff955a5b6208530b05fa1c983ab153d90f00216517a7a99478b988 +size 7074 diff --git a/marked/F/T-REC-F.748.18-202212-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg b/marked/F/T-REC-F.748.18-202212-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..70955d8d7cc9e19fb132a8dc109e7753e099f05b --- /dev/null +++ b/marked/F/T-REC-F.748.18-202212-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:beb119da2291681c267ddd88ed0154e8e9f9471b768a5d594f84731ae7424d18 +size 64120 diff --git a/marked/F/T-REC-F.748.18-202212-I_PDF-E/raw.md b/marked/F/T-REC-F.748.18-202212-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..46b48c58fb5c83e369e4c06d6d802b040b14fb17 --- /dev/null +++ b/marked/F/T-REC-F.748.18-202212-I_PDF-E/raw.md @@ -0,0 +1,551 @@ + + +# Recommendation **ITU-T F.748.18 (12/2022)** + +SERIES F: Non-telephone telecommunication services +Multimedia services + +--- + +## **Metric and evaluation methods for AI-enabled multimedia application computing power benchmark** + +![ITU logo](390120de4fe440c42fea8154fcaad334_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +### **TELEGRAPH SERVICE** + +| | | +|-----------------------------------------------------------------|-------------| +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | + +### **MOBILE SERVICE** + +| | | +|--------------------------------------------------------|-------------| +| Mobile services and multdestination satellite services | F.110–F.159 | +|--------------------------------------------------------|-------------| + +### **TELEMATIC SERVICES** + +| | | +|-------------------------------------------|-------------| +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | + +### **MESSAGE HANDLING SERVICES** + +F.400–F.499 + +### **DIRECTORY SERVICES** + +F.500–F.549 + +### **DOCUMENT COMMUNICATION** + +| | | +|--------------------------------------|-------------| +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | + +### **DATA TRANSMISSION SERVICES** + +F.600–F.699 + +### **MULTIMEDIA SERVICES** + +**F.700–F.799** + +### **ISDN SERVICES** + +F.800–F.849 + +## **UNIVERSAL PERSONAL TELECOMMUNICATION** + +F.850–F.899 + +## **ACCESSIBILITY AND HUMAN FACTORS** + +F.900–F.999 + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.748.18 + +# Metric and evaluation methods for AI-enabled multimedia application computing power benchmark + +## Summary + +Recommendation ITU-T F.748.18 provides an artificial intelligence (AI) computing power benchmark framework, evaluation metrics and methods, and a guideline for technical testing for AI clusters. Facing more diverse AI computing systems, users hope to have a unified evaluation metric for the system that provides AI computing power. The establishment of relevant real application performance evaluation benchmarks can objectively reflect the current state of the AI computing ability by providing objective metrics and comparison dimensions. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.748.18 | 2022-12-14 | 16 | 11.1002/1000/15195 | + +## Keywords + +AI computing power, benchmark, metric, training. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2023 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|----------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Overview of AI computing power benchmark ..... | 2 | +| 6.1 Evaluation object ..... | 2 | +| 6.2 Evaluation principle..... | 3 | +| 6.3 Evaluation mechanism..... | 3 | +| 7 Architecture framework of AI computing power benchmark ..... | 3 | +| 7.1 Workload ..... | 4 | +| 7.2 Metrics..... | 4 | +| 7.3 AI computing power benchmark ..... | 5 | +| 8 Technical testing for AI computing power benchmark ..... | 6 | +| Appendix I – OPS calculation..... | 7 | +| Appendix II – Fixed and customizable configurations ..... | 8 | +| Appendix III – Reference of the benchmark workloads ..... | 9 | +| Bibliography..... | 10 | + + + +# Recommendation ITU-T F.748.18 + +## Metric and evaluation methods for AI-enabled multimedia application computing power benchmark + +# 1 Scope + +This Recommendation provides the artificial intelligence (AI) computing power benchmark framework, evaluation metrics and methods, and a guideline for technical testing for the cluster. + +It addresses the following subjects: + +- a) Architecture framework of AI computing power benchmark; +- b) Metrics of AI computing power benchmark; +- c) Evaluation method of AI computing power benchmark; +- d) Technical testing of AI computing power benchmark. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 benchmark** [b-ITU-T F.748.11]: Benchmark is an evaluation method with a long-term application in the entire computer field. Example: As computer architecture advanced, it became more difficult to compare the performance of various computer systems simply by looking at their specifications. Therefore, tests were developed that allowed the comparison of different architectures (i.e., providing benchmarks). + +**3.1.2 deep learning software framework** [b-ITU-T F.748.12]: A tool that uses a set of pre-built and optimized components to define a model to achieve the encapsulation of artificial intelligence algorithms, data calls, and the use of computing resources. + +**3.1.3 machine learning (ML)** [b-ITU-T Y.3172]: Processes that enable the computational system to understand data and gain knowledge from it without necessarily being explicitly programmed. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following term: + +**3.2.1 artificial intelligence computing power**: A metric of computing power capacity of a system that includes AI accelerators. + +NOTE – The metric is defined based on the performance of the system and the AI model accuracy. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|-----------------------------------------| +| AI | Artificial Intelligence | +| ASIC | Application-Specific Integrated Circuit | +| BLEU | Bilingual Evaluation Understudy | +| CNN | Convolutional Neural Network | +| DUT | Device Under Test | +| FP | Forward Propagation | +| FPGA | Field Programmable Gate Array | +| GAN | Generative Adversarial Network | +| GPU | Graphics Processing Unit | +| HPC | High Performance Computing | +| HPO | Hyper-Parameter Optimization | +| MAC | Multiply-Accumulate | +| MIoU | Mean Intersection over Union | +| NAS | Neural Architecture Search | +| NFS | Network File System | +| NPU | Neural Processing Unit | +| OPS | Operations Per Second | +| PSNR | Peak Signal to Noise Ratio | +| PSU | Power Supply Unit | +| RAM | Random-Access Memory | +| RNN | Recurrent Neural Network | +| SSIM | Structural Similarity Index Measure | + +# 5 Conventions + +The following conventions are used in this Recommendation: + +- The keywords "**is required to**" indicate a requirement that must be strictly followed and from which no deviation is permitted, if conformance to this Recommendation is to be claimed. +- The keywords "**is recommended**" indicate a requirement that is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +# 6 Overview of AI computing power benchmark + +## 6.1 Evaluation object + +AI computing systems could provide strong computing support for multimedia applications, data centres, or edge computing scenarios powered by artificial intelligence (AI) algorithms and software. As an artificial intelligence device is equipped with a graphics processing unit (GPU), field programmable gate array (FPGA), application-specific integrated circuit (ASIC), and other + +acceleration chips, the device under test (DUT) could be a PC, workstation high performance computing (HPC) data centre, etc. + +## **6.2 Evaluation principle** + +#### **6.2.1 Practicality** + +Benchmarking methods should be built based on the representative artificial intelligence applications and be able to produce robust results. Benchmarking methods are recommended to cover commonly used AI models or algorithms in practical applications such as convolutional neural network (CNN), recurrent neural network (RNN), generative adversarial network (GAN), autoencoder, transformer, vision transformer, and conventional machine learning algorithms. The benchmark is performed by evaluating the training speed of the above models or algorithms. + +### **6.2.2 Fairness** + +Benchmarking methods should provide a fair comparison by specifying rules and metrics and be based on objective scientific test data during the evaluation process. As the architecture of AI hardware platforms varies, different AI hardware utilizes different accelerating methods or even different precision formats to maximize computing efficiency. In this case, the accelerating method and precision format for each benchmarking score must be explicitly noted for a fair comparison. In addition to the total score, it is also necessary to demonstrate the sub-scores of each evaluation item to reflect the advantages or disadvantages of each AI platform for particular scenarios. + +#### **6.2.3 Scalability** + +Benchmarking methods should provide variable scale workloads to make full use of the computing resources of the artificial intelligence computing system to reflect its computing power. The benchmarking methods can run on a single-node device with relatively lower computational performance, as well as the ability to run on a large-scale cluster with multiple nodes or units in a highly parallelized fashion. + +#### **6.2.4 Repeatability** + +Benchmarking methods should ensure that the error of measurement results is within a certain controllable range while using the same benchmark implementation under the same configurations on multiple trials. The benchmarking score needs to be calculated by averaging the results of multiple runs instead of the result of a single run. + +## **6.3 Evaluation mechanism** + +The benchmarking program uses a representative and auto-adaptive or scalable workload to establish an end-to-end benchmark suite for the AI computing power system. Once the benchmark process is complete, an overall score representing the computational power and stability, and the sub-scores representing the individual computing power of different application scenarios are demonstrated. + +# **7 Architecture framework of AI computing power benchmark** + +The benchmarking framework consists of three parts, as shown in Figure 1, which are 1) workload as the input part, 2) AI computing power benchmark with a specific evaluation environment, and 3) metric as the output part with the benchmark score. + +![Figure 1: Architecture framework of AI computing power benchmark. The diagram shows three main components: Workload, Evaluation system, and Metric. Workload includes Data preparation, Feature engineering, and Model generation (Algorithm and Hyperparameter). Evaluation system includes Deep learning software framework and AI acceleration chips (Cluster) (CPU, GPU, FPGA, NPU, ...). Metric includes Score (Accuracy, Performance) and Energy efficiency. Arrows show the flow from Workload to Evaluation system to Metric. A label F.748.18(22) is at the bottom right.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +F.748.18(22) + +Figure 1: Architecture framework of AI computing power benchmark. The diagram shows three main components: Workload, Evaluation system, and Metric. Workload includes Data preparation, Feature engineering, and Model generation (Algorithm and Hyperparameter). Evaluation system includes Deep learning software framework and AI acceleration chips (Cluster) (CPU, GPU, FPGA, NPU, ...). Metric includes Score (Accuracy, Performance) and Energy efficiency. Arrows show the flow from Workload to Evaluation system to Metric. A label F.748.18(22) is at the bottom right. + +**Figure 1 – Architecture framework of AI computing power benchmark** + +## 7.1 Workload + +A representative AI application is used as the workload which contains the critical components regarding the primary computing operations (e.g., sparse matrices multiplication), calculation precision (in a single-precision floating-point, half-precision floating-point, or other precision formats), and workflow in real AI scenarios (e.g., computer vision, neural language processing, speech recognition). The reference of the benchmark workloads can be found in Appendix III. + +### 7.1.1 Data preparation + +Data preparation involves data collection, data cleaning and data argumentation. To perform the benchmark objectively, the process of data preparation, input, and output dimensions of the data preparation in the AI benchmark should be similar to the actual application scenarios. Actual data instead of the matrix is recommended. + +### 7.1.2 Feature engineering + +Feature engineering involves feature selection, feature construction and feature extraction. They depend on the application scenarios and are irrelevant to the machine computing power, therefore it is not considered in the benchmark. + +### 7.1.3 Model generation + +Model generation involves algorithms and hyper-parameters. An algorithm means using specific approaches to generate the neural architecture and hyper-parameter optimization (HPO) is essentially the optimization of the loss function over the complex configuration space. Evaluation of models and algorithms in all kinds of real application scenarios is recommended to comprehensively evaluate the AI computing power of an AI computing hardware. + +## 7.2 Metrics + +Operations per second (OPS) or samples per second is used as the benchmark metric to describe the performance. The OPS here represents the number of computing operation counts that certain hardware can complete in the benchmark testing items. The samples per second is a result-oriented metric that can evaluate the computing efficiency of an AI hardware in practice. The benchmark score is required to be the weighted summation of each testing item (including training of each AI model or algorithm). + +### 7.2.1 AI computing power score + +The benchmark scoring metric is constructed based on not only the computing efficiency but also the reduction of the AI model accuracy. Therefore, a penalty factor is recommended to demonstrate this effect. An example of the benchmark metric is shown below: + +$$Score_{total} = \sum_{i=1}^{test\ items} [\lambda_{sub_i} \cdot Score_{sub_i}] \quad (1)$$ + +And the sub-scores can be formulated as: + +$$Score_{sub_i} = accuracy^2 \cdot performance, performance = OPS \text{ or } \frac{samples}{second} \quad (2)$$ + +Where *accuracy* will be: + +$$accuracy = 1 - reduction \quad (3)$$ + +And *reduction* will be: + +$$reduction = \chi(error) \cdot error, \chi(x): \begin{cases} 1, x \geq 0 \\ 0, x < 0 \end{cases} \quad (4)$$ + +And *error* will be: + +$$error = \frac{metric_{theoretical} - metric_{tested}}{metric_{theoretical}} \quad (5)$$ + +Here, $Score_{sub_i}$ is the performance score of training in the i-th benchmark testing item which can be measured by OPS or samples per second. $\lambda_{sub_i}$ is the weighting parameters corresponding to the scores. The *reduction* is calculated by the *error* which is a penalty factor to reflect the accuracy reduction of models or algorithms. The *error* here is the ratio of the difference between test results and theoretical results and the theoretical results are the accuracy result of the models or algorithms demonstrated in original papers or official benchmarks of certain datasets. The resulting metric can be any type of metric (such as accuracy, F1-score, mean intersection over union (MIOU), peak signal to noise ratio (PSNR), structural similarity index measure (SSIM), or bilingual evaluation understudy (BLEU)) corresponding to specific tasks. Once the benchmark process is completed, both the $Score_{total}$ represents the overall AI performance and the $Score_{sub_i}$ represent the AI performance for each specific task that should be demonstrated. This AI computational power metric example considers both the computational power of various practical AI tasks and the accuracy degradation in AI computational acceleration or optimization. This example can be used as a reference for the setting of the AI computing metric. + +### 7.2.2 Energy efficiency + +Energy efficiency, which is the ratio of AI computing power to electric power assumption, is also a key factor for AI computing systems. The computing power is evaluated by the AI benchmark process of various AI tasks in OPS and the electric power assumption is measured by a power meter in watts. + +## 7.3 AI computing power benchmark + +AI computing power benchmark includes the testing environment with hardware specification and evaluation environment. + +### 7.3.1 Hardware specification + +Hardware specification involves the information of the processor, AI accelerator, storage, and the Ethernet network. The configuration (including clock speed of GPU, CPU, random-access memory (RAMs) and other components, cooling systems, and power supply unit (PSU) systems) of the hardware applied in the benchmark needs to be identical to the mass production version. Hardware parameters and configurations must be indicated and cheating designed for the benchmark is prohibited. + +### 7.3.2 Evaluation environment + +The evaluation environment involves the information of the system, deep learning framework, and the related software. Since the environment configuration and acceleration method significantly impacts the benchmark results, the settings of the test environment and acceleration method need to be indicated. + +# 8 Technical testing for AI computing power benchmark + +The workflow of an end-to-end benchmark suite utilizing the automated machine learning (AutoML) as a workload to evaluate the performance of a heterogeneous AI computing power system is shown in Figure 2. + +![Schematic diagram of the benchmark workflow](042733dc5e8e7f5f30b60adba3266cde_img.jpg) + +The diagram illustrates the benchmark workflow. At the top, 'User access' connects to a 'Primary node' via an 'SSH' connection. The 'Primary node' is part of a 'Cluster of machines' and is connected to a 'Task distributed by the network' block. This block is connected to multiple 'Replica nodes', each containing 'Generate' and 'Train' components, with an ellipsis between them indicating additional nodes. The 'Replica nodes' are connected to an 'NFS' (Network File System) block. The 'NFS' block is connected back to the 'Primary node'. + +``` + +graph TD + User[User access] -- SSH --- Primary[Primary node] + subgraph Cluster [Cluster of machines] + Primary <--> TaskDist[Task distributed by the network] + TaskDist <--> Gen1[Generate] + TaskDist <--> Train1[Train] + TaskDist <--> Dots[...] + TaskDist <--> Gen2[Generate] + TaskDist <--> Train2[Train] + + Gen1 --- Train1 + Gen2 --- Train2 + + Replica1[Replica nodes] -.- Gen1 + Replica1 -.- Train1 + end + Gen1 --> NFS((NFS)) + Train1 --> NFS + Gen2 --> NFS + Train2 --> NFS + NFS --> Primary + +``` + +F.748.18(22) + +Schematic diagram of the benchmark workflow + +**Figure 2 – Schematic diagram of the benchmark workflow** + +The benchmark workflow is described as follows, to ensure the utilization of the AI accelerator, steps 3 and 4 are usually run in parallel. Steps 3-4 are cycled until the running terminates once the condition is satisfied (e.g., reaching user-defined time): + +Step 1: The user accesses the primary node through the secure shell (SSH) and collects the information about replica nodes. + +Step 2: Primary node dispatches workloads by the network to the replica nodes corresponding to the requested and available resources, parallelly and asynchronously. + +Step 3: The CPUs on the replica nodes search for new architectures based on the current historical model list, which contains detailed model information and accuracy on the test dataset, then store the candidate architecture in the buffer (e.g., network file system (NFS)) for later training. + +Step 4: The AI accelerators on replica nodes load the candidate architecture and data, utilize data parallelism to train along with the hyper-parameter optimization (HPO), and then store the results in the historical model list. + +Step 5: The final results are calculated based on the recorded metrics and then reported. + +# Appendix I + +## OPS calculation + +(This appendix does not form an integral part of this Recommendation.) + +Table I.1 and Table I.2 give the analytical operation counts of each layer (per image) in the forward propagation (FP) and backward propagation (BP) respectively. + +The analytical operation counts each layer (per image) in the FP. For the convolutional layer, the input image dimension is $H_i \times W_i \times C_i$ , the output dimension is $H_o \times W_o \times C_o$ , and the kernel (filter) size is $K \times K$ . For the dense layer, the input is $C_i$ and the output is $C_o$ . + +**Table I.1 – The analytical operation counts in FP** + +| Layer | Operation in the FP | +|----------------------|----------------------------------------------------------------| +| Convolutional layer | $MAC = K \times K \times C_i \times H_o \times W_o \times C_o$ | +| Dense layer | $MAC = C_i \times C_o$ | +| Batch normalization | $MAC = Add = Div = H_i \times W_i \times C_i$ | +| ReLU | $Comparison = H_o \times W_o \times C_o$ | +| Add layer | $Add = H_o \times W_o \times C_o$ | +| Max-pooling layer | $Comparison = K \times K \times H_o \times W_o \times C_o$ | +| Global-pooling layer | $Add = H_i \times W_i \times C_i ; Div = C_i$ | +| Softmax layer | $Exp = Add = Div = C_o$ | + +The analytical operation counts each layer (per image) in the BP. The meanings of the symbols are the same as in Table I.1. The total operation needed for calculating the gradients and updating the parameters are summed. + +**Table I.2 – The analytical operation counts in BP** + +| Layer | Operation in the BP | +|---------------------|----------------------------------------------------------------------------------------------------------------| +| Convolutional layer | $MAC = 2 \times (K \times K \times C_i \times H_o \times W_o \times C_o) + (K \times K \times C_i \times C_o)$ | +| Dense layer | $MAC = 2 \times C_i \times C_o + (C_i + 1) \times C_o$ | + +## Appendix II + +## Fixed and customizable configurations + +(This appendix does not form an integral part of this Recommendation.) + +Table II.1 gives the summarized configurations. These fixed and customizable configurations allow users to optimize the performance. + +To ensure fairness in the benchmark, key parameters in the benchmark are required to be fixed in each testing item. The following table takes a neural architecture search (NAS)-based AutoML task as an example to demonstrate the parameter settings in the benchmark process. + +**Table II.1 – Summarized configurations** + +| Configuration | Fixed and customizable setups | +|------------------------------|-----------------------------------------| +| Server arrangement | Fixed: Primary-replica | +| NAS method | Fixed: Network morphism | +| HPO method | Fixed: Bayesian optimization | +| Dataset | Fixed: ImageNet | +| DL framework | Default: TensorFlow | +| Initial architecture | Fixed: ResNet-50 | +| Initial weight | Default: Method in | +| Batch size | Default: 448 | +| Optimizer | Default: Gradient descent with momentum | +| Learning rate | Default: 0.1 with linear decay | +| Loss function | Default: Categorical cross entropy | +| Maximum epoch | Default: 60 | +| Parallelism | Default: Synchronous all-reduce | +| Parallel data transformation | Default: 48 | +| Minimum precision | Fixed: Half-precision floating-point | +| Maximum error | Fixed: 30% | + +## Appendix III + +## Reference of the benchmark workloads + +(This appendix does not form an integral part of this Recommendation.) + +Table III.1 gives references to benchmark workloads, which include the application scenarios, datasets and models. + +**Table III.1 – Benchmark workloads** + +| No. | Application scenarios | Dataset | Model | +|-----|-----------------------|-------------|------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Image classification | ImageNet | ResNet-50 and ResNet-101, the architecture and implementation can be found in [b-He] | +| | | | MobileNetV3, the architecture and implementation can be found in [b-Howard] | +| | | | Swin transformer, the architecture and implementation can be found in [b-Liu] | +| 2 | Object detection | COCO | Faster, the architecture and implementation can be found in [b-Ren] | +| | | | HRNet, the architecture and implementation can be found in [b-Sun] | +| | | | YOLOv5, the architecture and implementation can be found in [b-Zhu] | +| 3 | Segmentation | ADE20K | DeepLabV3+, the architecture and implementation can be found in [b-Chen] | +| | | | SegFormer, the architecture and implementation can be found in [b-Xie] | +| | | | BiSeNetV2, the architecture and implementation can be found in [b-Yu] | +| 4 | Super-resolution | IXI Dataset | Residual dense network for image super-resolution, the architecture and implementation can be found in [b-Zhang], [b-Wang] and [b-Ledig] | +| 5 | Face recognition | CelebA | FaceNet, the architecture and implementation can be found in [b-Schroff] | +| 6 | Machine translation | WMT 2014 | T5-11B, the architecture and implementation can be found in [b-Raffel] | +| 7 | Question answering | SQuAD1.1 | LUKE, the architecture and implementation can be found in [b-Yamada] | +| 8 | Recommendation | MovieLens | Graph convolutional matrix completion, the architecture and implementation can be found in [b-Berg.] | + +## Bibliography + +- [b-ITU-T F.748.11] Recommendation ITU-T F.748.11 (2020), *Metrics and evaluation methods for a deep neural network processor benchmark*. +- [b-ITU-T F.748.12] Recommendation ITU-T F.748.12 (2021), *Deep learning software framework evaluation methodology*. +- [b-ITU-T Y.3172] Recommendation ITU-T Y.3172 (2019), *Architectural framework for machine learning in future networks including IMT-2020*. +- [b-Berg] Berg, R.V.D., Kipf, T.N., and Welling, M. (2017), *Graph Convolutional Matrix Completion*. +<> +- [b-Chen] Chen, L.-C., Papandreou, G., Schroff, F., and Adam, H. (2017), *Rethinking Atrous Convolution for Semantic Image Segmentation*. +<> +- [b-He] He, K., Zhang, X., Ren, S., and Sun, J. (2016), *Deep Residual Learning for Image Recognition*. +<> +- [b-Howard] Howard, A., Sandler, M., Chu, G., Chen, L.-C., Chen, B., Tan, M., Wang, W., Zhu, Y., Pang, R., Vasudevan, V., Le, Q.V., and Adam, H. (2019), *Searching for MobileNetV3*. +<> +- [b-Ledig] Ledig, C., Theis, L., Huszar, F., Caballero, J., Cunningham, A., Acosta, A., Aitken, A., Tejani, A., Totz, J., Wang, Z., and Shi, W. (2017), *Photo-Realistic Single Image Super-Resolution Using a Generative Adversarial Network*. +<> +- [b-Liu] Liu, Z., Lin, Y., Cao, Y., Hu, H., Wei, Y., Zhang, Z., Lin, S., and Guo, B. (2021), *Swin Transformer: Hierarchical Vision Transformer using Shifted Windows*. +<> +- [b-Raffel] Raffel, C., Shazeer, N., Roberts, A., Lee, K., Narang, S., Matena, M., Zhou, Y., Li, W., and Liu, P.J. (2020), *Exploring the Limits of Transfer Learning with a Unified Text-to-Text Transformer*. *Journal of Machine Learning Research* 21, 1-67. +<> +- [b-Ren] Ren, S., He, K., Girshick, R., and Sun, J. (2016), *Faster R-CNN: Towards Real-Time Object Detection with Region Proposal Networks*. +<> +- [b-Schroff] Schroff, F., Kalenichenko, D., and Philbin, J. (2015), *FaceNet: A Unified Embedding for Face Recognition and Clustering*. +<> +- [b-Sun] Sun, K., Xiao, B., Liu, D., and Wang, J. (2019), *Deep High-Resolution Representation Learning for Human Pose Estimation*. +<> + +- [b-Wang] Wang, X., Yu, K., Wu, S., Gu, J., Liu, Y., Dong, C., Chen, C.L., Qiao, Y., and Tang, X. (2018), *ESRGAN: Enhanced Super-Resolution Generative Adversarial Networks*. +<> +- [b-Xie] Xie, E., Wang, W., Yu, Z., Anandkumar, A., Alvarez, J.M., and Luo, P. (2021), *SegFormer: Simple and Efficient Design for Semantic Segmentation with Transformers*. +<> +- [b-Yamada] Yamada, I., Asai, A., Shindo, H., Takeda, H., and Matsumoto, Y. (2020), *LUKE: Deep Contextualized Entity Representations with Entity-aware Self-attention*. +<> +- [b-Yu] Yu, C., Wang, J., Peng, C., Gao, C., Yu, G., and Sang, N. (2018), *BiSeNet: Bilateral Segmentation Network for Real-time Semantic Segmentation*. +<> +- [b-Zhang] Zhang, Y., Tian, Y., Kong, Y., Zhong, B., and Fu, Y. (2018), *Residual Dense Network for Image Super-Resolution*. +<> +- [b-Zhu] Zhu, X., Lyu, S., Wang, X., & Zhao, Q. (2021), *TPH-YOLOv5: Improved YOLOv5 Based on Transformer Prediction Head for Object Detection on Drone-captured Scenarios*. +<> + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.748.19-202212-I_PDF-E/053f1077d592e6622cd21dc4bb4cb366_img.jpg b/marked/F/T-REC-F.748.19-202212-I_PDF-E/053f1077d592e6622cd21dc4bb4cb366_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ea420b3cc68d3c41dfbde84afe48c0371abd5a49 --- /dev/null +++ b/marked/F/T-REC-F.748.19-202212-I_PDF-E/053f1077d592e6622cd21dc4bb4cb366_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:93e21433c4f5ef179e2b0eece38971ee03a0031401c1deff2607342288d0afd9 +size 43979 diff --git a/marked/F/T-REC-F.748.19-202212-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg b/marked/F/T-REC-F.748.19-202212-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..abda52cbb1047d6649f89e40c898a1c33bed7267 --- /dev/null +++ b/marked/F/T-REC-F.748.19-202212-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:6f3b7e07231c0f3e116c99c493bdda98ecd52313b6735faa6cea23815cf3162b +size 7190 diff --git a/marked/F/T-REC-F.748.19-202212-I_PDF-E/8e14350b4b669119a3bdfca7869110ca_img.jpg b/marked/F/T-REC-F.748.19-202212-I_PDF-E/8e14350b4b669119a3bdfca7869110ca_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8b86cec6351ed51ccffff62264ca1f72b3e85425 --- /dev/null +++ b/marked/F/T-REC-F.748.19-202212-I_PDF-E/8e14350b4b669119a3bdfca7869110ca_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:61e4ecc48bf3f2db154a2f5bbef4d7714ba2beaf98aaf8e04450d7524696397d +size 51807 diff --git a/marked/F/T-REC-F.748.19-202212-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg b/marked/F/T-REC-F.748.19-202212-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c3425889bec787ac25c8ffebc87d5af1ee470b3d --- /dev/null +++ b/marked/F/T-REC-F.748.19-202212-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:c817b48f5ab3c5ef268e7b4ac112e93cd20877f47c8699cbc629bb2b25768046 +size 73166 diff --git a/marked/F/T-REC-F.748.19-202212-I_PDF-E/raw.md b/marked/F/T-REC-F.748.19-202212-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..4083d693eb9e1870eafcebbd0da9363b58575cb6 --- /dev/null +++ b/marked/F/T-REC-F.748.19-202212-I_PDF-E/raw.md @@ -0,0 +1,489 @@ + + +# Recommendation **ITU-T F.748.19 (12/2022)** + +SERIES F: Non-telephone telecommunication services +Multimedia services + +# --- **Framework for audio structuralizing based on deep neural networks** + +![ITU logo](390120de4fe440c42fea8154fcaad334_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multidestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| MULTIMEDIA SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.748.19 + +# Framework for audio structuralizing based on deep neural networks + +## Summary + +Recommendation ITU-T F.748.19 presents an overview of the framework for audio structuralizing based on deep neural network. It provides a high-level description of architecture, processing flows, data categories, audio processing tasks and requirements for data management. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.748.19 | 2022-12-14 | 16 | 11.1002/1000/15196 | + +## Keywords + +Audio structuralizing, deep neural network. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2023 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-------------------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 2 | +| 6 Background of audio structuralizing ..... | 2 | +| 7 Technical framework of the audio structuralizing system..... | 2 | +| 7.1 Metadata extraction subsystem..... | 3 | +| 7.2 Deep neural network-based audio processing subsystem ..... | 3 | +| 7.3 External system ..... | 3 | +| 7.4 Data integration and storage subsystem ..... | 3 | +| 7.5 Data capability opening subsystem ..... | 4 | +| 8 Categories of data in the audio structuralizing system ..... | 4 | +| 8.1 Metadata ..... | 4 | +| 8.2 Intelligent data ..... | 4 | +| 8.3 Transaction data..... | 4 | +| 8.4 Integration data ..... | 4 | +| 9 Deep neural network-based audio processing tasks ..... | 5 | +| 9.1 Standalone task ..... | 5 | +| 9.2 Multitask..... | 8 | +| 10 Requirements for data management in the audio structuralizing system ..... | 8 | +| 10.1 Data collection..... | 8 | +| 10.2 Data storage ..... | 8 | +| 10.3 Data integration ..... | 9 | +| 10.4 Data open service ..... | 9 | +| Bibliography..... | 10 | + + + +# Recommendation ITU-T F.748.19 + +## Framework for audio structuralizing based on deep neural networks + +# 1 Scope + +This Recommendation presents an overview of the framework for audio structuralizing based on deep neural network. It provides a high-level description of architecture, processing flows, data categories, audio processing tasks and data management. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 speech** [b-ITU-T H.703]: Speech is the vocalized form of human communication. + +**3.1.2 structured data** [b-ITU-T Y.4500.1]: Data that either has a structure according to a specified information model or is otherwise organized in a defined manner. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following term: + +**3.2.1 audio structuralizing**: A method that makes unstructured audio data structured and provides forms of representation that allows interpretation of the meaning of information. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|-------------------------------------------| +| API | Application Programming Interface | +| ASR | Automatic Speech Recognition | +| CNN | Convolutional Neural Network | +| GFCC | Gammatone Frequency Cepstral Coefficients | +| LSTM | Long Short-Term Memory | +| MFCC | Mel Frequency Cepstral Coefficients | +| PLP | Perceptual Linear Prediction | +| RNN | Recurrent Neural Network | +| TDNN | Time Delay Neural Network | + +# 5 Conventions + +The following conventions are used in this Recommendation: + +- The keywords "**is recommended**" indicate a requirement that is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +# 6 Background of audio structuralizing + +In recent years, with the development of computer science, Internet and telecommunication technology, the amount of multimedia data such as video, audio and image has exploded. As one of the main forms of multimedia, audio plays an increasingly pervasive role in our lives. + +Faced with massive amounts of audio content, how to make full and effective use of existing content and explore the value of content has become an urgent problem to be solved. Manually labelling and classifying audio content are very time-consuming. Also, as human hearing fatigues, the accuracy of manual classification will decrease. + +As a non-semantic symbolic representation and unstructured binary stream, audio lacks a clear description of structured information and content semantics. This Recommendation provides a framework for audio structuralizing and aims to make unstructured audio data structured and provide forms of representation that allow interpretation of the meaning of information. The value of audio structuralizing is reflected in the following aspects: + +- a) Audio structuralizing provides different processing methods for different types of audio data. For example, automatic speech recognition (ASR) can be used to automatically create written records of broadcast news; targeted noise reduction processing can be adopted for different environmental sounds. +- b) Audio structuralizing plays an important auxiliary role in grading and indexing video. For example, detecting, locating and identifying violent segments such as gunshots, explosions and screams in multimedia. +- c) Audio structuralizing establishes the association between the underlying structural units of audio and high-level semantic content, which facilitates in-depth analysis and processing of audio information. For example, quick retrieval of the audio segment of a specified speaker by applying voiceprint recognition technology. + +# 7 Technical framework of the audio structuralizing system + +The audio structuralizing system is a set of audio data analysis and management subsystems that combines audio processing, deep learning and big data technology. The system can effectively analyse, organize and manage audio data, and can be easily accessed by downstream applications. An overview of the recommended technical framework of the audio structuralizing system is shown in Figure 1. + +![Figure 1 – Technical framework of the audio structuralizing system. The diagram shows a hierarchical flow of data from 'Original audio' at the top, through three parallel processing paths: 'External system' (producing 'Transaction data'), 'Metadata extraction subsystem' (producing 'Metadata'), and 'Deep neural network based audio processing subsystem' (producing 'Intelligent data'). All three data types are then fed into a 'Data integration and storage subsystem' which contains 'Data collection', 'Data integration', and 'Data storage'. This subsystem is further connected to a 'Data capability opening subsystem' containing 'Micro service', 'Data interface', and 'APIs'. A reference code 'F.748.19(22)' is visible in the bottom right of the diagram area.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +``` + +graph TD + OA[Original audio] --> ES[External system] + OA --> MS[Metadata extraction subsystem] + OA --> DNAPS[Deep neural network based audio processing subsystem] + ES -- "Transaction data" --> DIS[Data integration and storage subsystem] + MS -- "Metadata" --> DIS + DNAPS -- "Intelligent data" --> DIS + DIS --> DCOS[Data capability opening subsystem] + subgraph DNAPS [Deep neural network based audio processing subsystem] + P[Pre-processing] + FE[Feature extraction] + DNM[Deep neural network model] + end + subgraph DIS [Data integration and storage subsystem] + DC[Data collection] + DI[Data integration] + DS[Data storage] + end + subgraph DCOS [Data capability opening subsystem] + MS2[Micro service] + DI2[Data interface] + API[APIs] + end + +``` + +F.748.19(22) + +Figure 1 – Technical framework of the audio structuralizing system. The diagram shows a hierarchical flow of data from 'Original audio' at the top, through three parallel processing paths: 'External system' (producing 'Transaction data'), 'Metadata extraction subsystem' (producing 'Metadata'), and 'Deep neural network based audio processing subsystem' (producing 'Intelligent data'). All three data types are then fed into a 'Data integration and storage subsystem' which contains 'Data collection', 'Data integration', and 'Data storage'. This subsystem is further connected to a 'Data capability opening subsystem' containing 'Micro service', 'Data interface', and 'APIs'. A reference code 'F.748.19(22)' is visible in the bottom right of the diagram area. + +**Figure 1 – Technical framework of the audio structuralizing system** + +## 7.1 Metadata extraction subsystem + +Metadata extraction subsystem refers to the system that extracts the basic features of audio files. + +## 7.2 Deep neural network-based audio processing subsystem + +The function of this subsystem is to perform structural analysis of the original audio based on deep neural network. According to the different tasks, the corresponding structured data can be parsed and extracted. The general processing steps include, but are not limited to: + +- 1) Audio pre-processing, such as voice enhancement, voice activity detection. +- 2) Feature extraction. The feature is generally a single-dimensional or multi-dimensional feature vector group arranged in time series. For example, mel frequency cepstral coefficients (MFCC) is a 39-dimensional feature vector, and perceptual linear prediction (PLP) is a 13-dimensional feature vector. The feature is generally extracted every 25 ms to 30 ms. Different tasks will select different relative features. +- 3) Modelling based on deep neural networks. Common deep neural networks include convolutional neural networks (CNNs), long short-term memory (LSTM), recurrent neural network (RNN), time delay neural network (TDNN), etc. Developers can select or design appropriate neural networks according to the data set and tasks to perform model training and extract structured data. + +## 7.3 External system + +External system refers to a system that contains additional valuable information. For example, a service platform that stores calling voice data includes calling number, called number, call duration, call time, call ID, etc. + +## 7.4 Data integration and storage subsystem + +After cleaning, associating and matching metadata, intelligent data and data from other systems, integration data is generated through technologies such as database table association and knowledge + +graphs. Data is associated from multiple service dimensions to form rich and valuable integration data. + +The integration data and original audio data are stored persistently. When the amount of data continues to accumulate, big data storage technology will be adopted to ensure the efficiency of external retrieval and query. + +## 7.5 Data capability opening subsystem + +The data capability opening subsystem provides data to the external system in the form of micro-services, data interfaces and application programming interfaces (APIs). At the same time, it can also provide structured audio big data capabilities for retrieval, query, statistics, analysis, reasoning and other services. Take the task of automatic speech recognition as an example. Automatic speech recognition can directly provide its speech recognition capabilities and/or combine the recognition results with metadata from other systems and/or structured data from other joint tasks to form new structured data ability. + +# 8 Categories of data in the audio structuralizing system + +Clause 8 describes the categories of data in the audio structuralizing system, as shown in Figure 2. + +![Figure 2: Categories of data in the audio structuralizing system. A hierarchical diagram showing 'Integration data' at the top, branching into three categories: 'Metadata', 'Intelligent data', and 'Transaction data'. 'Metadata' includes encoding format, resolution, audio generation time, file size, and data source. 'Intelligent data' includes spoken content, speaker ID, timestamp, confidence, classification ID, quality score, and feature vector. 'Transaction data' includes calling number, called number, call duration, call time, and call ID.](053f1077d592e6622cd21dc4bb4cb366_img.jpg) + +| | | | +|----------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------| +| Integration data | | | +| Metadata | Intelligent data | Transaction data | +| Encoding format, resolution, audio generation time, file size, data source, etc. | Spoken content, speaker ID, timestamp, confidence, classification ID, quality score, feature vector, etc. | Calling number, called number, call duration, call time, call ID, etc. | + +Figure 2: Categories of data in the audio structuralizing system. A hierarchical diagram showing 'Integration data' at the top, branching into three categories: 'Metadata', 'Intelligent data', and 'Transaction data'. 'Metadata' includes encoding format, resolution, audio generation time, file size, and data source. 'Intelligent data' includes spoken content, speaker ID, timestamp, confidence, classification ID, quality score, and feature vector. 'Transaction data' includes calling number, called number, call duration, call time, and call ID. + +F.748.19(22) + +Figure 2 – Categories of data in the audio structuralizing system + +## 8.1 Metadata + +Metadata refers to the basic features in the audio files, such as encoding format, resolution, audio generation time, file size, data source, etc. + +## 8.2 Intelligent data + +Intelligent data refers to specific information extracted from original audio based on machine learning or deep learning algorithms according to different scenarios and tasks, such as semantic text extracted through ASR, character ID, timestamp and x-vector extracted through voiceprint recognition and voice separation. + +## 8.3 Transaction data + +Transaction data in the external system can be used as an input source of the data integration and storage subsystem. In addition to the original audio data and its derived data, data from other sources can bring additional information to the audio. For example, a customer service platform that stores call voice transaction data including calling number, called number, call duration, call time, call ID, etc. + +## 8.4 Integration data + +Integration data is formed by metadata, intelligent data and transaction data. For example, combining transaction data in the customer service system and intelligent data such as speech content and + +voiceprint can determine whether the content of the conversation involves fraud and whether the voice is that of the alleged speaker. + +# 9 Deep neural network-based audio processing tasks + +According to the realization methods of tasks, audio processing tasks are divided into two categories: standalone task and multi-task. Standalone task is designed to tackle with a single service requirement. + +Multi-task learning is different from single task learning in the training (induction) process in that inductions of multiple tasks are performed simultaneously to capture intrinsic relatedness. Multi-task learning can enable our model to generalize better on our original task. + +The outputs of the tasks are divided into structured data and unstructured data. This clause analyses and explains various types of tasks in detail. + +Organizations need to clearly inform and obtain consent of individuals when collecting face images and/or voiceprint, and implement solutions that ensure the protection of personally identifiable information. + +The recommended outputs of standalone tasks are described in Figure 3. + +![Flowchart showing the processing flow of audio structuralizing based on deep neural network. The input 'Original audio' is processed through 'Unstructured binary stream' and 'Tasks' (Automatic speech recognition, Voiceprint recognition, ...) to produce 'Outputs' (Text, Punctuation, Timestamp, Voiceprint feature vectors, Speaker ID, ...).](8e14350b4b669119a3bdfca7869110ca_img.jpg) + +``` +graph LR; subgraph Headers; H1[Unstructured binary stream]; H2[Tasks]; H3[Outputs]; end; OA[Original audio] --> ASR[Automatic speech recognition]; OA --> VR[Voiceprint recognition]; OA --> Dots1[...]; ASR --> T[Text]; ASR --> P[Punctuation]; ASR --> TS[Timestamp]; VR --> TS; VR --> VFV[Voiceprint feature vectors]; VR --> SID[Speaker ID]; VR --> Dots2[...]; +``` + +F.748.19(22) + +Flowchart showing the processing flow of audio structuralizing based on deep neural network. The input 'Original audio' is processed through 'Unstructured binary stream' and 'Tasks' (Automatic speech recognition, Voiceprint recognition, ...) to produce 'Outputs' (Text, Punctuation, Timestamp, Voiceprint feature vectors, Speaker ID, ...). + +**Figure 3 – Overview processing flows of audio structuralizing based on deep neural network** + +## 9.1 Standalone task + +#### 9.1.1 Automatic speech recognition + +Automatic speech recognition refers to the process of converting human voice signals into words or instructions. The output includes speech text, punctuation and the corresponding timestamp. + +#### 9.1.2 Voiceprint recognition + +The voiceprint feature is the spectrogram feature of the speaker's voice. Voiceprint recognition, also known as speaker recognition, refers to the process of identifying the speaker corresponding to the speech segment based on the voiceprint characteristics. The outputs are voiceprint feature vectors, speaker ID and timestamp. + +#### **9.1.3 Speaker diarization** + +Speaker diarization aims to solve the problem of "who spoke when", the outputs are speaker identities, their respective speech segments and timestamps. + +#### **9.1.4 Speech separation** + +Speech separation aims to extract the speaker's voice from the speech with background sound. The outputs can be speech files, speech streams or speech segments of speaker. + +#### **9.1.5 Audio scene classification** + +Audio scene classification aims to add semantic tags to the environment by analysing the environmental sounds, such as home scenes, vehicle scenes, natural environments and subway scenes. The output result is the category ID of the audio scene. + +#### **9.1.6 Sound event detection** + +Sound event detection aims to detect the presence of a target audio event and its occurrence time in a segment of audio, such as the sound of an explosion. The outputs are the event ID and its corresponding timestamp. + +#### **9.1.7 Specific speech detection** + +Specific speech detection aims to detect specific speech content. The outputs include the specific content classification ID and timestamp. + +#### **9.1.8 Spoofed and fake audio detection** + +Spoofed and fake audio detection aims to identify whether the voice is actually the alleged speaker. The common methods of speech spoofing are text-to-speech, voice conversion and replay. + +#### **9.1.9 Equipment fault diagnosis based on acoustics** + +Industrial inspection based on acoustics refers to detecting whether the sound collected in machine tools, machinery and equipment is abnormal. The output results include category ID of equipment fault. + +#### **9.1.10 Animal classification based on acoustics** + +Animal classification can determine the species and class of the animal. The output is animal category ID. + +#### **9.1.11 Keyword spotting** + +The purpose of keyword spotting is to detect all occurrences of specified words in the speech signal. The output is corresponding timestamp. + +#### **9.1.12 Speech enhancement** + +Speech enhancement refers to the process of beamforming for multi-channel speech, noise suppression, acoustic echo cancelling and dereverberation for single-channel speech. The signal-to-noise ratio of speech can be improved, and the output can be an enhanced speech time-domain or frequency-domain waveform. + +#### **9.1.13 Audio feature extraction** + +The purpose of feature extraction is to extract new features closely related to a specific task from the original feature data. Commonly used methods include MFCC, FFT, PLP, gammatone frequency cepstral coefficients (GFCC). The output result can be a one-dimensional or multi-dimensional feature vector set arranged in time series. + +#### 9.1.14 Voice quality evaluation + +Performs voice quality assessment on speech with background noise or reverberation, and the output can be a quality score. + +#### 9.1.15 Age classification based on voice + +The age range of the speaker is predicted by analysing the speaker's voice sample, voice file or voice stream, and the output is the category ID of age range. + +#### 9.1.16 Gender classification based on voice + +The gender of the speaker is predicted by analysing the speaker's voice sample, voice file or voice stream, and the output is the category ID of gender. + +#### 9.1.17 Musical instrument classification + +Musical instrument classification aims to identify whether there are musical instruments in the audio clip and the type of musical instrument. The outputs include instrument category ID and the corresponding timestamp. + +Table 1 lists the outputs of the above standalone audio task and whether it can be output as structured data. + +**Table 1 – Standalone audio tasks and output** + +| Standalone Task | Output | Types of data | +|----------------------------------------------|-------------------------------------------------------------------|----------------------| +| Automatic speech recognition | Speech text, punctuation, timestamp | Structured data | +| Voiceprint recognition | Voiceprint feature vectors, speaker ID, timestamp | Structured data | +| Speaker diarization | Speaker ID, speech segment, timestamp | Structured data | +| Speech separation | Speech files, speech stream or speech segment of speaker | Unstructured data | +| Audio scene classification | Category ID of audio scene | Structured data | +| Sound event detection | Event ID, timestamp | Structured data | +| Specific speech detection | ID of specific speech, timestamp | Structured data | +| Spoofed and fake audio detection | Whether it is actually the alleged speaker | Structured data | +| Equipment fault diagnosis based on acoustics | Category ID of equipment fault | Structured data | +| Animal classification based on acoustics | Category ID of animals | Structured data | +| Keyword spotting | Timestamp | Structured data | +| Speech enhancement | Speech segments, speech files or speech streams after enhancement | Unstructured data | +| Audio feature extraction | One-dimensional or multi-dimensional feature vector | Unstructured data | +| Voice quality evaluation | Score of voice quality | Structured data | +| Age classification based on voice | Category ID of age range | Structured data | +| Gender classification based on voice | Female or male | Structured data | +| Musical instrument classification | Category ID of musical instrument | Structured data | + +### **9.2 Multitask** + +In clause 9.2, several examples of multi-task learning are provided and explained. + +#### **9.2.1 Integration of ASR and voiceprint recognition** + +Refers to the simultaneous running of automatic speech recognition and voiceprint recognition in the same model. In the process of joint training, both automatic speech recognition data and voiceprint recognition data can provide more additional information for each other's tasks, and obtain better recognition results than separate training. + +#### **9.2.2 Joint recognition of face and voice** + +The joint recognition of face and voice means that the system recognizes the user's voice while recognizing the user's face, and obtains the face recognition result and the voice recognition result at the same time. One possible application scenario is to require the user to read a random verification code when face authentication is performed to improve the reliability of authentication. + +#### **9.2.3 Integration of voiceprint recognition and spoofed audio detection** + +Through multi-task learning, a model that can perform voiceprint recognition and spoofed audio detection at the same time is established, and output the authenticity of the voice and spoofed audio clips. + +# **10 Requirements for data management in the audio structuralizing system** + +During the system operation, varying types of structured and unstructured data such as operational data, service reports, program logs and operational texts will be generated. These data are usually distributed in different subsystems, and most of them include hidden attributes and behaviour characteristics of users or services. Through the unified data collection, correlation, and analysis in the audio structuralizing system, enterprises will get useful intelligent data for better operation and provide powerful data support for third-party organizations in a capacity-opening architecture. + +## **10.1 Data collection** + +The data collection process includes data review, extraction, cleaning and conversion. Data collection is recommended to support the operating data of different service sources in the system and follow the predetermined collection strategy. Converting data with different structures and formats into data with a unified format and clear association identification can reduce the complexity of subsequent data processing to a certain extent. The processed data is recommended to meet certain technical requirements, such as uniqueness and relevance. The data collection and pre-processing are recommended to complete the analysis and classification of the data model while retaining the safety and integrity of the original data. + +## **10.2 Data storage** + +The structured data after audio task processing is recommended to meet the persistence requirements. Due to the diversity of the output data from the different logical processing in each subsystem, the construction of multi-source and multi-structure data fusion requires coordination of multiple different storage categories. For example, the metadata, operation data and daily reports are mainly stored as structured data; the original audio and audio clips of the call system are stored in the form of files; the multi-dimensional matrix after the audio feature extraction is stored in a vector database. + +The system is recommended to determine the storage types based on the characteristics and relationship types of each metadata. Generally speaking, the key-value database and document database in relational databases and non-relational databases can basically meet the storage requirements of audio structuralizing systems. Vector retrieval databases are recommended to be used for audio feature vector storage and retrieval. + +## **10.3 Data integration** + +Data integration refers to the formation of a consensus model through certain strategies and methods of heterogeneous data collected and organized above. The goal of data integration is to provide a structured database that can be used directly and easily managed, which ultimately provides a basis for various models. This includes a series of data pre-processing and provides a foundation for subsequent data opening capabilities. In the pre-processing, second data cleaning is recommended, which includes filtering non-compliant data, deleting duplicate data, correcting data, and converting format. However, the data after processing may still be unrelated, redundant or missing some information. Therefore, the integration process is recommended to standardize and redefine the data in the repository, and perform subject division and data association if necessary. The processed data is gathered in the data sharing centre and used for subsequent modelling. The specification of data includes the designation of the correspondence between the basic dimensions of the service metadata and the service identifier of the fact table; it can also be the correspondence between the service attributes of the audio file and the structured attributes. In the end, the association and integration of audio attributes and service features will organize the diversified big data, and generate valuable data that satisfy the requirements of refined operation and production. + +## **10.4 Data open service** + +The data open service will build a knowledge graph based on the data sharing centre. It not only provides users with model management, model exploration and data exploration, but also provides intelligent services such as mining analysis and professional modelling. The core knowledge graph is a giant knowledge network composed of nodes and edges. Nodes represent entities, and edges represent relationships between entities. Each entity describes the internal characteristics of the entity through key-value pairs. In addition, modelling can be performed based on core data such as entities and relationships in the knowledge graph, and high-level data mining analysis and processing can be performed. Therefore, unified data collection, data integration and data opening can construct an overall structured model. + +## Bibliography + +- [b-ITU-T H.703] Recommendation ITU-T H.703 (2016), *Enhanced user interface framework for IPTV terminal devices.* +- [b-ITU-T Y.4500.1] Recommendation ITU-T Y.4500.1 (2018), *OneM2M- Functional architecture.* + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V 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It features a blue globe with a white grid pattern, overlaid by the letters 'ITU' in a bold, blue, sans-serif font. The globe is stylized with a white arrow pointing upwards and to the right, symbolizing global connectivity and communication. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.748.30 + +# Requirements of communication services for digital humans + +## Summary + +Digital human technology is developing rapidly and is being used in various fields. Recommendation ITU-T F.748.30 defines the communication services for digital humans and the requirements for developing and utilizing digital humans. This Recommendation defines entities and their roles in communication services for digital humans, interaction and communication types between entities, and describes human and digital human communication service types. It also defines the concept model for communication services for digital humans. + +Emotions and memories are needed for perfect communication, and digital human communication also requires emotions and memories. This Recommendation also defines requirements of communication services of digital human using emotions and memory. + +### History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.748.30 | 2024-06-13 | 16 | 11.1002/1000/15912 | + +## Keywords + +Digital human, communication service, emotion, memory. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2024 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +###### Page + +| | | | +|------|-----------------------------------------------------------------------------------|----| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| 3.1 | Terms defined elsewhere ..... | 1 | +| 3.2 | Terms defined in this Recommendation..... | 2 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | Conventions ..... | 2 | +| 6 | Communication services for digital human..... | 2 | +| 7 | Entities and roles in communication services for digital human..... | 3 | +| 7.1 | Digital human ..... | 3 | +| 7.2 | Digital human creator ..... | 3 | +| 7.3 | Content creator ..... | 3 | +| 7.4 | End user ..... | 4 | +| 7.5 | Environment ..... | 4 | +| 8 | Interaction and communication types among entities ..... | 4 | +| 8.1 | Digital human creation ..... | 4 | +| 8.2 | Digital human controlling..... | 4 | +| 8.3 | Communication ..... | 5 | +| 8.4 | Interaction between digital humans and an environment..... | 5 | +| 9 | Requirements on interaction and communication ..... | 5 | +| 9.1 | Digital human creation ..... | 5 | +| 9.2 | Digital human controlling..... | 5 | +| 9.3 | Communication ..... | 6 | +| 9.4 | Interaction between digital humans and an environment..... | 7 | +| 10 | Service requirements ..... | 7 | +| 10.1 | Service requirements for digital human creators..... | 7 | +| 10.2 | Functional requirements for non-interactive users ..... | 7 | +| 10.3 | Functional requirements for users on two-way communication ..... | 8 | +| 10.4 | Functional requirements for users and contents creators on imitating control..... | 8 | +| 10.5 | Functional requirements for static contents creators ..... | 8 | +| 11 | Human and digital human communication service types..... | 9 | +| 11.1 | Non-interactive human and digital human communication ..... | 9 | +| 11.2 | Interactive human and digital human communication ..... | 9 | +| 11.3 | Digital human and digital human communication ..... | 10 | +| 12 | Concept model for communication services for digital human..... | 11 | +| 12.1 | Data description..... | 11 | + +| | Page | +|--------------------------------------------------------------------------|-------------| +| 12.2 Dialogue and emotion processing module ..... | 12 | +| 12.3 Digital human selection and creation module ..... | 12 | +| 12.4 Speech module..... | 13 | +| 12.5 Animation module ..... | 13 | +| Appendix I – Use cases of communication services for digital human ..... | 15 | +| I.1 Introduction ..... | 15 | +| I.2 Non-interactive human and digital human communication ..... | 15 | +| I.3 Interactive human and digital human communication ..... | 16 | +| I.4 Digital human and digital human communication ..... | 17 | +| Bibliography..... | 18 | + +# Recommendation ITU-T F.748.30 + +## Requirements of communication services for digital humans + +## 1 Scope + +This Recommendation describes the concepts and requirements of *communication services for digital human*. The scope of this recommendation includes: + +- Entities and interactions in communication services for digital humans. +- Requirements for the user interface for those who are creating digital humans. +- Requirements for the digital human creation and utilization procedures. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T F.748.15] Recommendation ITU-T F.748.15 (2022), *Framework and metrics for digital human application systems*. + +[ITU-T H.862.5] Recommendation ITU-T H.862.5 (2021), *Emotion enabled multimodal user interface based on artificial neural networks*. + +[ITU-T H.862.6] Recommendation ITU-T H.862.6 (2023), *Functional requirements for counselling services based on artificial emotional intelligence*. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 content** [b-ITU-T H.780]: A combination of audio, still image, graphic, video, or data. + +**3.1.2 digital human** [ITU-T F.748.15]: A computer application that integrates the technologies of computer graphics, computer vision, intelligent speech and natural language processing. It can be used for digital content generation and human-computer interaction to help improve content production efficiency and user experience. + +**3.1.3 dynamic content** [b-ITU-T F.744.2]: Contents created on demand while a user dynamically operates a web application. + +**3.1.4 extended reality (XR)** [b-ITU-T P.1320]: An environment containing real or virtual components or a combination thereof, where the variable X serves as a placeholder for any form of new environment (e.g., augmented, assisted, mixed, virtual or diminished reality). + +**3.1.5 non-interactive digital human** [b-ITU-T F.748.14]: A digital human without the ability to interact, which can only read and execute commands. + +**3.1.6 question answering** [b-ITU-T F.746.3]: A system that provides answers in natural language to questions which are in natural language form by analysing the questions and all the knowledge resources that are available to the system. + +**3.1.7 static content** [b-ITU-T F.744.2]: Content that changes infrequently. This type of content is not changed with the requests of users. + +**3.1.8 videoconference service** [b-ITU-T F.702]: An audiovisual conversational conference service providing bidirectional real-time transfer of voice and motion video between groups of users in two or more separate locations. Although the audio and motion video information are the essential part of the service, other types of information, such as high resolution still pictures, text or graphics may also be exchanged. + +**3.1.9 virtual reality (VR)** [b-ITU-T P.1320]: An environment that is fully generated by digital means. To qualify as virtual reality, the virtual environment should differ from the local environment. + +### **3.2 Terms defined in this Recommendation** + +None. + +## **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +CSDH      Communication Service for Digital Human + +DB          Database + +VR          Virtual Reality + +XR          Extended Reality + +## **5 Conventions** + +In this Recommendation: + +- The keywords "**is required to**" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. +- The keywords "**is recommended**" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. +- The keywords "**can optionally**" indicate an optional requirement which is permissible, without implying any sense of being recommended. These terms are not intended to imply that the vendor's implementation must provide the option and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the specification. + +## **6 Communication services for digital human** + +A digital human is displayed in a digital space having the appearance and voice of a human and acts like a human. A digital human can communicate with humans using human-like features such as facial expressions and gestures, and allows them to have more realistic conversations compared to the past text-based chatting services. The development of digital human production technology can enrich human communication and provide opportunities for more experiences. + +Communication services for digital humans (CSDHs) are defined as services that use digital humans to expand human communication opportunities. CSDHs solve temporal and spatial limitations of communication. CSDHs include services in various fields like education, entertainment and customer services. + +![Figure 1: Overall structure of a CSDH. The diagram shows three main components: Human users, Communication service, and Digital human. Human users (enclosed in a dashed box) include Digital human creator, Contents creator, and End user. Communication service includes Digital human creation, Contents creation, Speech generation, and Animation generation. Digital human is a single box. Double-headed arrows connect Human users to Communication service, and Communication service to Digital human. A label F.748.30(24) is present at the bottom right.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +Figure 1: Overall structure of a CSDH. The diagram shows three main components: Human users, Communication service, and Digital human. Human users (enclosed in a dashed box) include Digital human creator, Contents creator, and End user. Communication service includes Digital human creation, Contents creation, Speech generation, and Animation generation. Digital human is a single box. Double-headed arrows connect Human users to Communication service, and Communication service to Digital human. A label F.748.30(24) is present at the bottom right. + +**Figure 1 – Overall structure of a CSDH** + +## 7 Entities and roles in communication services for digital human + +Figure 2 shows the entities and the types of each entity involved in CSDHs. + +![](7a0db9703b68b3d06cdaeefc084c0006_img.jpg) + +| | Digital human | Human | | | Environment | +|--------------|----------------------------|-----------------------|--------------------------|----------------------|-------------| +| Entity | Digital human | Digital human creator | Contents creator | End user | Environment | +| Entity types | Controllable digital human | | Static contents creator | Non-interactive user | | +| | Autonomous digital human | | Dynamic contents creator | Interactive user | | + +F.748.30(24) + +**Figure 2 – Entities involved in CSDHs** + +### 7.1 Digital human + +A digital human acts as a movable avatar representing a human or a machine agent in a digital human communication service. Followings are the two types of digital humans classified by controlling methods. + +- Controllable digital human: A digital human which is only actuated from controls of a person, which can be either a content creator or an end user. +- Autonomous digital human: A digital human incorporated with a machine agent, which voice, motion, behaviour, and other human-like aspects are autonomously generated. + +### 7.2 Digital human creator + +A digital human creator is a person who creates new digital humans, which can be utilized later in CSDHs. + +### 7.3 Content creator + +A content creator is a person who produces digital human contents using controlled digital humans. + +- Static content creator: A content creator that generates static contents from digital humans in advance of communication. Non-interactive digital humans are often used for static content generation. +- Dynamic content creator: A content creator that generates dynamic digital human contents during a real-time communication session. + +### 7.4 End user + +An end user is a person who consumes the digital human contents displayed from the service and provides interaction to the service. The end user should be able to access the desired service by interacting with a device such as a kiosk or the user's smartphone. + +- Non-interactive user: An end user that only consumes contents from a CSDH. +- Interactive user: An end user that not only consumes contents, but also provides interaction to a CSDH. The types of interaction may be multimodal. + +### 7.5 Environment + +An environment provides a digital space that multiple digital humans can reside in and interact together. XR environments such as VR can be integrated for CSDHs. + +## 8 Interaction and communication types among entities + +Figure 3 demonstrates the interaction and communication types among various entities. + +![Figure 3: Interaction and communication types, with corresponding requirements. The diagram is a 3x3 grid with a legend below. The columns are 'Control', 'Communication', and 'Other interactions and supplementary'. The rows show different interaction types: Driving control, Dynamic contents creator, Interactive user, and Imitating control. The legend defines symbols for One-way communication, Two-way communication, Imitating control, Driving control, Interaction, Memorization, and Creation.](c2fc2621e8206d24427b56bcb2398fc0_img.jpg) + +| Control | Communication | Other interactions and supplementary | +|------------------------------------------------------------------------------------------|----------------------------------------------------------------------|-----------------------------------------------------------------------| +| Driving control
Contents creator → Controllable digital human | One-way communication
Digital human → Non-interactive user | Other interactions
Digital human creator -.-> Digital human | +| Dynamic contents creator
Dynamic contents creator → Controllable digital human | Two-way communication
Digital human ↔ Interactive user | Environment
Digital human ↔ Environment | +| Interactive user
Interactive user → Controllable digital human | Emotion
Autonomous digital human ↔ Interactive user | Supplementary
Autonomous digital human ↔ Memory | +| Imitating control | | | + + + +| | | | | | | | +|-------------------------|-------------------------|---------------------|-------------------|---------------|----------------|------------| +| ↓ One-way communication | ↕ Two-way communication | ↓ Imitating control | ↓ Driving control | ↕ Interaction | ↕ Memorization | ↓ Creation | +|-------------------------|-------------------------|---------------------|-------------------|---------------|----------------|------------| + +F.748.30(24) + +Figure 3: Interaction and communication types, with corresponding requirements. The diagram is a 3x3 grid with a legend below. The columns are 'Control', 'Communication', and 'Other interactions and supplementary'. The rows show different interaction types: Driving control, Dynamic contents creator, Interactive user, and Imitating control. The legend defines symbols for One-way communication, Two-way communication, Imitating control, Driving control, Interaction, Memorization, and Creation. + +**Figure 3 – Interaction and communication types, with corresponding requirements** + +### 8.1 Digital human creation + +Digital human creation is a type of one-way action from a digital human creator to a newly made digital human. + +### 8.2 Digital human controlling + +Controlling is a type of one-way action from a content creator or an end user to a controllable digital human, such that the user directs behaviour of the controllable digital human according to the user's will. For effective communication, the user may want to drive the digital human in a custom manner, or may want the digital human to imitate their own actions. + +- (Driving control) A contents creator may drive the behaviour of a controllable digital human by text, timed script, or parameters to create digital human contents. +- (Imitating control) A contents creator may capture the own behaviour via camera, microphone, or other recordable means, and let the digital human imitate the behaviour of the creator. + +### 8.3 Communication + +Communication includes one-way action toward non-interactive end users, or two-way interaction between a digital human to an interactive end user, or between digital humans. + +- (One-way communication) One-way communication indicates delivering digital human contents to end users, either synchronously or asynchronously. +- (Two-way communication) Two-way communication indicates synchronous conversation between a digital human and a human or another digital human. Multimodal behaviour information, such as video or audio, is commonly conveyed throughout the communication. +- (Memorization) Memorization indicates the aspect of autonomous digital humans that record the communication context such as chat history, to supplement further communications. + +### 8.4 Interaction between digital humans and an environment + +A digital human may interact with the environment where other digital humans can reside in. + +## 9 Requirements on interaction and communication + +Requirements on the types of interaction and communication among the entities of clause 8 are discussed in this clause. + +### 9.1 Digital human creation + +Table 1 describes requirements of digital human creation. + +**Table 1 – Requirements of digital human creation** + +| Requirement | Description | +|---------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| (Req. 9.1.1) Digital human creation |

A digital human service can optionally allow digital human creators to construct or adopt a new digital human.

A digital human service can optionally allow digital human creators to mix or customize features of real or digital humans to create a new digital human.

| +| (Req. 9.1.2) Creating digital human persona |

A digital human service can optionally allow digital human creators to create the digital human persona of a new digital human.

A digital human service can optionally allow digital human creators to control the disclosure range of a digital human's persona depending on who they are conversing with.

| + +### 9.2 Digital human controlling + +Table 2 describes requirements of digital human controlling. + +**Table 2 – Requirements of digital human controlling** + +| Requirement | Description | +|------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| (Req. 9.2.1) Driving control |

A digital human service can optionally allow a static content creator to drive a controllable, often non-interactive digital human, to produce static digital human contents.

The control is recommended to take place via text, timed script, parameters, or other means except imitation.

The digital human service is recommended to store static digital human contents for future interactions with end users.

| + +**Table 2 – Requirements of digital human controlling** + +| Requirement | Description | +|-----------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| (Req. 9.2.2) Imitating control | A digital human service can optionally allow a controllable digital human to imitate its controlling person, who are either a content creator or an end user.
The control is recommended to take place via video analysis, motion capture, voice analysis, or other possibly real-time means. | +| (Req. 9.2.3) Relaying contents to controlling users | A controllable digital human under imitating control is required to relay the received multimodal contents to the controlling user, without or with modifications such as language translation. | + +### 9.3 Communication + +Table 3 describes requirements of one-way communication, while Table 4 describes requirements of two-way communication. + +**Table 3 – Requirements of one-way communication** + +| Requirement | Description | +|----------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------| +| (Req. 9.3.1.1) Contents delivery | Upon end user's requests, the digital human service is recommended to deliver corresponding static digital human contents from the demand of the end user. | +| (Req. 9.3.1.2) Streaming | A digital human service can optionally stream multimodal contents of digital human to participants of the corresponding communication session. | + +**Table 4 – Requirements of two-way communication** + +| Requirement | Description | +|--------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| (Req. 9.3.2.1) Behaviour capturing | Behaviour of a digital human, regardless of autonomous or controlled, is recommended to be described through multimodal means and sent to the communication counterparts.
Behaviour of an end user is recommended to be directly captured through multimodal means from the user device and sent to the communication counterparts. | +| (Req. 9.3.2.2) Emotion-based communication | An autonomous digital human is recommended to extract the emotion from received media of communication counterparts.
If the digital human is implemented based on artificial neural networks, the emotion enabled user interface is required to follow descriptions in [ITU-T H.862.5].
An autonomous digital human is recommended to utilize the emotion to decide the next behaviour. | +| (Req. 9.3.2.3) Memorization | An autonomous digital human can optionally record the history of the participating communication, and utilize the memorized information to generate next behaviour adapted to the counterpart.
If an autonomous digital human records the history of the participating communication, personal information (such as facial appearance, important information, etc.) is recommended be stored in a removed or anonymized state. | + +### 9.4 Interaction between digital humans and an environment + +Table 5 describes requirements of interaction between digital humans and an environment. + +**Table 5 – Requirements of interaction between digital humans and an environment** + +| Requirement | Description | +|--------------------------|----------------------------------------------------------------------------------------------------------------------------------------| +| (Req. 9.4.1) Recognition | Digital humans embedded in an environment are recommended to recognize surrounding information described in the current environment. | +| (Req. 9.4.2) Reaction | The environment surrounding digital human is recommended to change with respect to behaviour of digital humans within the environment. | + +## 10 Service requirements + +### 10.1 Service requirements for digital human creators + +Table 6 describes the functions of a CSDH for digital human creators, and the corresponding requirements. + +**Table 6 – Service requirements for digital human creators** + +| Requirement | Description | +|----------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| (Req. 10.1.1) Extracting | The service is recommended to allow digital human creators to upload media of a real or another digital human, for the extraction of digital human features. | +| (Req. 10.1.2) Modelling | The service can optionally allow digital human creators to create the exterior appearance of a digital human, by either providing editing tools or allowing upload of corresponding files containing graphical information. | +| (Req. 10.1.3) Feature management | The service is recommended to show a list of digital human features to digital human creators they can access and provide corresponding management interfaces. | +| (Req. 10.1.4) Modulation | The service can optionally allow digital human creators to select digital human features of the same type and enter required modulation parameters to create a new digital human feature. | +| (Req. 10.1.5) Feature selection | The service is recommended to allow digital human creators to select one digital human feature for each type to construct a digital human. | +| (Req. 10.1.6) Memory management | The service is recommended to allow digital human creators to view and modify memory of digital humans in human readable form. The access to the memory can optionally be controlled by the creators. | + +### 10.2 Functional requirements for non-interactive users + +Table 7 describes the functions of a CSDH for non-interactive users, and the corresponding requirements. + +**Table 7 – Service requirements for non-interactive users** + +| Requirement | Description | +|----------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| (Req. 10.2.1) On-demand content access | The service is required to provide non-interactive users a list of static digital human contents, currently accessible dynamic digital human contents, or optionally, replays of dynamic digital human contents. The service is recommended to deliver media of users' choices with proper media streaming or playback control interfaces. | +| (Req. 10.2.2) Reaction posting | The service can optionally allow non-interactive users to post reactions, such as replies and likes, which is to be delivered to contents creators through a channel aside of communication channels involving digital humans. | + +### **10.3 Functional requirements for users on two-way communication** + +Table 8 describes the functions of a CSDH for interactive users on two-way communication, and the corresponding requirements. + +**Table 8 – Service requirements for users on two-way communication** + +| Requirement | Description | +|----------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| (Req. 10.3.1) Listing digital humans for two-way communication | The interactive communication service is required to provide interactive users a list of available digital humans they can communicate with in two-way communication. | +| (Req. 10.3.2) Recording | The service is recommended to collect multimodal media, such as text, audio and video, from the interactive users. Appropriate device controlling interface is recommended to be provided to the users. | +| (Req. 10.3.3) Emotion-enabled communication | The service with emotion-enabled communication is recommended to follow the user interfaces described in [ITU-T H.862.5]. | + +### **10.4 Functional requirements for users and contents creators on imitating control** + +Table 9 describes the functions of a CSDH for users and content creators on imitating control of a digital human, and the corresponding requirements. + +**Table 9 – Service requirements for users and contents creators on imitating control** + +| Requirement | Description | +|--------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| (Req. 10.4.1) Listing digital humans for control | The service is required to provide interactive users a list of available digital humans they can control. | +| (Req. 10.4.2) Behaviour capturing | The service is recommended to capture the controller's movement, and apply the corresponding motion to the digital human. | +| (Req. 10.4.3) Environment feedback | The service with environment is recommended to deliver the feedback as effects on visual displays or speakers. If the users have specific devices for sensing, the service is recommended to deliver environment feedback to the sensing devices. | + +### **10.5 Functional requirements for static contents creators** + +Table 10 describes the functions of a CSDH for static contents creators, and the corresponding requirements. + +**Table 10 – Service requirements for static contents creators** + +| Requirement | Description | +|---------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| (Req. 10.5.1) 2D content creation interface | The service is recommended to provide means for contents creators to put any video, shape, or audio of their desire on their digital human video. The service is recommended to allow contents creators to assign visual background from image or document files. | +| (Req. 10.5.2) 3D content creation interface | The service is recommended to provide means for contents creators to put any 3D objects of their desire, audio with its optional source location, and select point of view to render digital human video. | +| (Req. 10.5.3) Script reading | The service is recommended to allow static contents creators to provide a set of scripts that digital humans will read. The service can optionally provide contents creators multilingual script support. | +| (Req. 10.5.4) Driving control | The service is recommended to allow static contents creators to choose a set of motions. The service can optionally allow static contents creators to set actions of the digital human in time intervals of the creators' choices. | +| (Req. 10.5.5) Reaction delivery | The service is recommended to deliver reactions of the users to the corresponding contents creators. The responses to dynamic contents creator are recommended to be delivered in real time. | + +## **11 Human and digital human communication service types** + +### **11.1 Non-interactive human and digital human communication** + +Communication between humans and digital humans could be done in one way without interaction, when the end users only consume digital human contents. Contents consumption can be classified into static and dynamic contents consumption. + +#### **11.1.1 Static contents consumption** + +Various video content can be produced using digital humans, and end users can communicate with digital humans by consuming this content. Watching the video content made by a digital human is non-interactive, one-way communication. As end users consume static content, there is no need for digital humans to act in real-time, and the dialogue function is unnecessary. Figure 4(a-1) shows a conceptual diagram of how end users and digital humans communicate in content consumption. A content creator creates video content by controlling digital humans, and end users watch a produced video. + +#### **11.1.2 Dynamic contents consumption** + +It is also possible to create dynamic contents using digital humans. Content creators can create dynamic contents using digital humans that mimic their movements. The end users consume the real-time dynamic content without giving the creator any feedback, making the service non-interactive communication. However, unlike static content consumption, real-time digital human control is required to be possible, and imitation is used to control digital humans. Figure 4(a-2) shows a conceptual diagram of how humans and digital humans communicate in dynamic content consumption. + +### **11.2 Interactive human and digital human communication** + +In interactive human and digital human communication, humans and digital humans can communicate in two ways. The digital human and should include various functions such as real-time behaviour and dialogue processing. Interactive human and digital human communication is classified into video-based question answering and video-based emotion enabled chatting. + +#### 11.2.1 Video-based question answering + +A digital human appears on the screen and communicates with humans by answering questions, which is called video-based question answering. During video-based question answering, humans and digital humans interact. An end user asks a question to a digital human, and the digital human answers it. Therefore, digital humans must act in real-time in response to end-user's queries. Digital humans must have conversational skills and knowledge to answer questions. Figure 4(b-1) shows a conceptual diagram of how humans and digital humans communicate in question answering. + +For video-based question answering, the range of information that can be provided may vary depending on the user due to security reasons. Therefore, an access control feature that allows setting the range of information to be answered is recommended. + +#### 11.2.2 Video-based emotion enabled chatting + +Beyond question answering, a digital human can communicate with humans through dialogue, which is called video-based chatting. For video-based emotion enabled chatting, digital humans are recommended to be able to communicate with humans emotionally, and continuous conversations must be possible by remembering existing conversations. Therefore, digital humans are required to be capable of real-time actions and to have conversational capabilities. In addition, digital humans are recommended to have a multi-modal emotion recognition function, a memory of existing conversations, and the other emotion-related capabilities described in [ITU-T H.862.6]. Figure 4(b-2) shows a conceptual diagram of how end users and digital humans communicate in a video-based emotion enabled chatting service. + +The personalization feature is important for a video-based emotion enabled chatting service. Digital humans in the service are recommended to remember the conversation with the user, and recall user-customized conversations and actions. Furthermore, by understanding the habitual facial expressions or actions of the conversational partner, it should recognize their emotions and generate appropriate conversations and actions. One of the features could be mimicking the expressions or actions of the conversation partner. For these personalization solutions to be provided, the digital human should be able to evolve in real-time through conversations. + +### 11.3 Digital human and digital human communication + +Digital human and digital human communication is two-way communication between digital humans, where the digital human mediates human-human communication. Depending on the space where the digital human exists, services can be separated into non-immersive and immersive services. + +#### 11.3.1 Non-immersive CSDHs + +Non-immersive CSDHs, such as videoconference services, allow people to communicate through their digital humans. Each end user participates in non-immersive CSDHs by controlling the digital human in real time. Figure 4(c-1) shows a conceptual diagram of how digital humans communicate with digital humans in a non-immersive CSDH. The digital human imitates the end user's behaviour and communicates with the other's digital human. In this case, the digital human mediates human-to-human communication, but the digital human communicates with the other digital human on the interface. + +#### 11.3.2 Immersive CSDHs + +Immersive CSDHs, such as VR services, allow human users to control their digital humans to interact with objects or other digital humans in the virtual environment. In immersive CSDHs, the digital human also mediates human-to-human communication, but within the environment embedding both digital humans. Figure 4(c-2) shows a conceptual diagram of how digital humans communicate with digital humans in VR services. + +![Figure 4: Classification of digital human service types, based on communication patterns. The diagram is divided into three main sections: (a) Non-interactive human and digital human communication, (b) Interactive human and digital human communication, and (c) Digital human and digital human communication. Above the sections, a legend defines communication types: One-way communication, Two-way communication, Imitating control, Driving control, Interaction, and Memorization. Section (a) shows two paths: (a-1) Contents creator -> Controllable digital human -> Non-interactive user, and (a-2) Dynamic contents creator -> Controllable digital human -> Non-interactive user. Section (b) shows (b-1) Digital human <-> Interactive user, and (b-2) Memory <-> Autonomous digital human <-> Emotion <-> Interactive user. Section (c) shows (c-1) Interactive user <-> Controllable digital human <-> Controllable digital human <-> Interactive user, and (c-2) Interactive user <-> Controllable digital human <-> Environment <-> Controllable digital human <-> Interactive user.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg) + +Figure 4: Classification of digital human service types, based on communication patterns. The diagram is divided into three main sections: (a) Non-interactive human and digital human communication, (b) Interactive human and digital human communication, and (c) Digital human and digital human communication. Above the sections, a legend defines communication types: One-way communication, Two-way communication, Imitating control, Driving control, Interaction, and Memorization. Section (a) shows two paths: (a-1) Contents creator -> Controllable digital human -> Non-interactive user, and (a-2) Dynamic contents creator -> Controllable digital human -> Non-interactive user. Section (b) shows (b-1) Digital human <-> Interactive user, and (b-2) Memory <-> Autonomous digital human <-> Emotion <-> Interactive user. Section (c) shows (c-1) Interactive user <-> Controllable digital human <-> Controllable digital human <-> Interactive user, and (c-2) Interactive user <-> Controllable digital human <-> Environment <-> Controllable digital human <-> Interactive user. + +**Figure 4 – Classification of digital human service types, based on communication patterns** + +## 12 Concept model for communication services for digital human + +Figure 5 describes a concept model for communication services for digital human, following the framework in [ITU-T F.748.15]. Based on the requirements in clauses 9 and 10, submodules are suggested with respect to each module in the framework. + +![Figure 5: Overall structure of a concept model of an emotion-aware CSDH. The diagram shows the flow of data from the User through various modules. The User provides input to 'Multimodal input' and 'Selection'. 'Multimodal input' goes to 'Dialogue/emotion processing module', which outputs to 'Speech module' (labeled 1). 'Selection' goes to 'Digital human selection/creation module', which outputs to 'Speech module' (labeled 2) and 'Animation module' (labeled 3). 'Speech module' outputs to 'Multimodal output' (labeled 4). 'Animation module' outputs to 'Multimodal output' (labeled 5). 'Multimodal output' is then returned to the User.](df82d77a0d2637cbf2da9ea920a554fa_img.jpg) + +Figure 5: Overall structure of a concept model of an emotion-aware CSDH. The diagram shows the flow of data from the User through various modules. The User provides input to 'Multimodal input' and 'Selection'. 'Multimodal input' goes to 'Dialogue/emotion processing module', which outputs to 'Speech module' (labeled 1). 'Selection' goes to 'Digital human selection/creation module', which outputs to 'Speech module' (labeled 2) and 'Animation module' (labeled 3). 'Speech module' outputs to 'Multimodal output' (labeled 4). 'Animation module' outputs to 'Multimodal output' (labeled 5). 'Multimodal output' is then returned to the User. + +**Figure 5 – Overall structure of a concept model of an emotion-aware CSDH** + +### 12.1 Data description + +The following are descriptions of the data exchanged between a module and the end user, or between the modules depicted in Figure 5. + +- Multi-modal input: Media containing end user's behaviour trying to interact with the system, which may contain multiple modalities such as audio and video. +- Multi-modal output: Media produced by the system and delivered to the video creators or end users, usually in form of videos. +- Selection: Selected index of the digital human features in the internal digital human database +- Text (1): System's response text, either generated from the dialogue processing module or provided by video creators. + +- Emotion (1, 4): Emotion value of the system's response, either generated from the emotion processing module or provided by video creators. +- Digital human components (2, 3): Features of a digital human selected from the database, such as voice, face or body. +- Speech (5): Speech audio, generated from response text. + +### 12.2 Dialogue and emotion processing module + +In the interactive processing module in the framework, the dialogue and emotion processing module in Figure 6 processes an input speech of an end user and creates a text and an emotion as the response for the user. + +![Figure 6: Dialogue and emotion processing module diagram. The diagram shows a flow from 'Multimodal input' to a 'Dialogue/emotion processing module' box. Inside this box, there is a 'Personal dialogue and emotion DB' at the top, connected by double-headed arrows to a 'Speech to text' and 'Emotion detection' block (dashed box) and a 'Dialogue and emotion generation' block. Arrows point from the 'Speech to text' and 'Emotion detection' block to the 'Dialogue and emotion generation' block. The 'Dialogue and emotion generation' block has an arrow pointing to an 'Emotion' output box. The 'Personal dialogue and emotion DB' has an arrow pointing to a 'Text' output box. A label 'F.748.30(24)' is at the bottom right.](4356776ca004ecba5d599667a155d7d4_img.jpg) + +``` + +graph LR + Input[Multimodal input] --> Module[Dialogue/emotion processing module] + subgraph Module + DB[(Personal dialogue and emotion DB)] + subgraph SD [Speech to text and Emotion detection] + S2T[Speech to text] + ED[Emotion detection] + end + DEG[Dialogue and emotion generation] + DB <--> S2T + DB <--> DEG + S2T --> DEG + ED --> DEG + end + DB --> Text[Text] + DEG --> Emotion[Emotion] + F7483024[F.748.30(24)] + +``` + +Figure 6: Dialogue and emotion processing module diagram. The diagram shows a flow from 'Multimodal input' to a 'Dialogue/emotion processing module' box. Inside this box, there is a 'Personal dialogue and emotion DB' at the top, connected by double-headed arrows to a 'Speech to text' and 'Emotion detection' block (dashed box) and a 'Dialogue and emotion generation' block. Arrows point from the 'Speech to text' and 'Emotion detection' block to the 'Dialogue and emotion generation' block. The 'Dialogue and emotion generation' block has an arrow pointing to an 'Emotion' output box. The 'Personal dialogue and emotion DB' has an arrow pointing to a 'Text' output box. A label 'F.748.30(24)' is at the bottom right. + +**Figure 6 – Dialogue and emotion processing module** + +Submodules may include: + +- A speech to text submodule, to convert the input speech to the corresponding text, +- An emotion detection submodule, to sense the end user's emotion on the speech, and +- A dialogue and emotion generation submodule, to create the response for the end user. + +Database may include: + +- A personal dialogue and emotion database, to store the conversation records to make the conversation interactive. + +### 12.3 Digital human selection and creation module + +In the image module in the framework, the digital human selection and creation module in Figure 7 processes source digital humans selected by a digital human creator, and produces the digital human components by component-wise modulation. Face modulation is a procedure that averages features of multiple faces to create a new face, while the multiple faces comprise at least one face of a real human and/or at least one face of digital human. A similar procedure can be taken for modulation of body and voice, respectively. + +Submodules may include: + +- A face feature modulation submodule, to create face features of a new digital human, +- A body feature modulation submodule, to create body features of a new digital human, and +- A voice feature modulation submodule, to create voice features of a new digital human. + +Database may include: + +- A personal digital human database, to store features of digital human that each user has already created. + +![Figure 7: Digital human selection and creation module diagram](9c6461e1e94afae4dec455e69a2ce152_img.jpg) + +The diagram illustrates the 'Digital human selection/creation module'. On the left, a box labeled 'Selection' has an arrow pointing to the central module. The central module is a large box containing a 'Personal digital human DB' at the top, with a double-headed arrow below it labeled 'If user wants new digital human'. Below this, a dashed box contains three stacked boxes: 'Face feature modulation', 'Body feature modulation', and 'Voice feature modulation'. An arrow points from the central module to a box on the right labeled 'Digital human components'. The text 'F.748.30(24)' is at the bottom right. + +Figure 7: Digital human selection and creation module diagram + +**Figure 7 – Digital human selection and creation module** + +### 12.4 Speech module + +The Speech module in Figure 8 creates a speech audio such that the given response text is spoken with tones or accent reflecting the given response emotion, having the voice feature of the selected digital human. Emotion aspects are relayed to the next module. + +Submodules may include: + +- A text to speech submodule, to convert the input text to the corresponding speech considering the emotion, and +- A voice adaptation submodule, to apply the voice features of the selected digital human. + +![Figure 8: Speech module diagram](a734898ce18e972938949637c32a34f4_img.jpg) + +The diagram illustrates the 'Speech module'. On the left, a dashed box contains 'Emotion' and 'Text', with an arrow pointing to the 'Text to speech' box inside the 'Speech module'. Below the dashed box is a 'Digital human voice' box with an arrow pointing to the 'Voice adaptation' box inside the 'Speech module'. The 'Speech module' box contains 'Text to speech' and 'Voice adaptation'. Arrows point from 'Text to speech' to a 'Speech' box on the right, and from 'Voice adaptation' to an 'Emotion' box on the right. The text 'F.748.30(24)' is at the bottom right. + +Figure 8: Speech module diagram + +**Figure 8 – Speech module** + +### 12.5 Animation module + +The Animation module in Figure 9 creates the final output video using emotion, speech and digital human components. To make digital humans behave like they have emotions, the motion parameters are extracted from emotion. This can be implemented by looking up the motion database, or by dynamic generation. These motions drive the face and body of the selected digital human accordingly. + +Submodules may include: + +- A motion parameter extraction submodule, to extract motion corresponding to the given emotion, +- Facial/body motion generation submodules, to drive the face and the body according to the motion, and +- A face/body/speech fusion submodule, to attach the face and the body naturally and put all the media together. + +![Flowchart of the Animation module showing inputs (Emotion, Speech, Digital human components) entering the module, processing through motion parameter extraction, facial and body motion generation, and face/body/speech fusion, resulting in a multimodal output.](b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg) + +``` + +graph TD + subgraph Inputs + Emotion[Emotion] + subgraph DHC_Speech [ ] + Speech[Speech] + DHC[Digital human components] + end + end + + subgraph Animation_module [Animation module] + MPE[Motion parameter extraction] + subgraph Generation_Fusion [ ] + FMG[Facial motion generation] + BMG[Body motion generation] + FBSF[Face/body/speech fusion] + end + end + + MO[Multimodal output] + + Emotion --> MPE + DHC_Speech --> Generation_Fusion + MPE --> Generation_Fusion + Animation_module --> MO + +``` + +The diagram illustrates the 'Animation module'. On the left, three input components are shown: 'Emotion', 'Speech', and 'Digital human components'. 'Emotion' is a single box. 'Speech' and 'Digital human components' are grouped together in a dashed box. Arrows from these inputs point into the 'Animation module' box. Inside the module, 'Emotion' points to 'Motion parameter extraction'. This block points down to a dashed box containing 'Facial motion generation', 'Body motion generation', and 'Face/body/speech fusion'. Arrows from the 'Animation module' point out to a final box labeled 'Multimodal output'. + +F.748.30(24) + +Flowchart of the Animation module showing inputs (Emotion, Speech, Digital human components) entering the module, processing through motion parameter extraction, facial and body motion generation, and face/body/speech fusion, resulting in a multimodal output. + +**Figure 9 – Animation module** + +## Appendix I + +## Use cases of communication services for digital human + +(This appendix does not form an integral part of this Recommendation.) + +### I.1 Introduction + +The appendix describes use cases for each type of CSDH, described in clause 11. + +### I.2 Non-interactive human and digital human communication + +Non-interactive human and digital human communication is the most common and widely used type of a digital human service. + +#### I.2.1 Static contents consumption + +CSDHs serving static contents, described in Figure 4(a-1), can be utilized in the following use cases. + +- Consumption of educational content + +Digital humans can be used to create various educational contents, such as internet lectures, realistic contents, and even video contents that reproduce a historic person shown in Figure I.1. Either a teacher, a professor, or an educational content designer, can be classified as an educational content creator. Students would act as a non-interactive user that consumes the digital human content for education purposes and obtain information. + +![Figure I.1: An example of the use of a digital human in the education industry. The image shows a stylized digital human (a man and a woman) on the left, a speech bubble icon in the center, and a historical portrait of a man (likely a professor or teacher) on the right.](344b61635f2d962dbbb8ed925c8c8d48_img.jpg) + +The image consists of three distinct elements arranged horizontally. On the left is a stylized, flat-design illustration of a man and a woman standing side-by-side. The man is wearing a dark vest over a light shirt and trousers, while the woman is wearing a dark vest over a light shirt and a skirt. In the center is a simple line-art icon of two overlapping speech bubbles, each containing three dots. On the right is a black and white reproduction of a historical portrait of a man with curly hair, wearing a dark coat and a white cravat, holding a quill pen and writing on a piece of paper. + +Figure I.1: An example of the use of a digital human in the education industry. The image shows a stylized digital human (a man and a woman) on the left, a speech bubble icon in the center, and a historical portrait of a man (likely a professor or teacher) on the right. + +F.748.30(24) + +**Figure I.1 – An example of the use of a digital human in the education industry** + +- News delivery + +It is possible to create a news anchor video in advance using a digital human and share the produced video with people. If a broadcasting company needs to broadcast a breaking news, the company must suddenly make a video. Even if the anchor is not present, the situation can be resolved by using a digital human. + +- Entertainment and advertisement industry + +The characters appearing in advertisements or content are usually celebrities. Due to temporal and spatial limitations, the number of advertisements that celebrities can appear in is limited. Based on CSDHs, contents of celebrities can be created anytime, anywhere, beyond the temporal and spatial limits using a digital human, as seen in Figure I.2. + +![Figure I.2: A diagram showing the flow from a single celebrity silhouette to multiple digital human clones, which then lead to various content outputs like a talk show, a news broadcast, and a game show. The text 'F.748.30(24)' is at the bottom right.](e69b9188aa2c14ec6b21c83f711fef65_img.jpg) + +A celebrity                      Digital human clones                      Various contents +F.748.30(24) + +Figure I.2: A diagram showing the flow from a single celebrity silhouette to multiple digital human clones, which then lead to various content outputs like a talk show, a news broadcast, and a game show. The text 'F.748.30(24)' is at the bottom right. + +**Figure I.2 – An example of the usage of a digital human in entertainment industry** + +#### I.2.2 Dynamic contents consumption + +CSDHs serving dynamic contents, described in Figure 4(a-2), can be utilized on the following use case. + +- Real-time individual broadcasting + +In real-time individual broadcasting, broadcasters may want to hide in the back of a digital human to remain anonymous, or to satisfy the watchers with a character with desired appearance. The broadcasters, as dynamic contents creators, make the digital human mimic the broadcaster's behaviour. End users can consume the digital human contents by watching these real-time broadcasts. + +### I.3 Interactive human and digital human communication + +CSDHs with interactive human and digital human communication provide dedicated communication experiences to the end users. + +#### I.3.1 Video-based question answering + +CSDHs providing question answering, described in Figure 4(b-1), can be utilized in the following use case. + +- Customer service + +As shown in Figure I.3, companies can deploy digital humans in kiosks or web applications, rather than directly providing customer service. Through question answering, the customers may obtain what they need in a more immersive customer experience. Digital human creators can create a digital human according to the company's brand image and deliver it consistently to customers. + +![Figure I.3: A diagram comparing an 'Existing kiosk' (a person interacting with a touch screen) to a 'Kiosk with digital human' (three screens showing different digital human avatars). The text 'F.748.30(24)' is at the bottom right.](c98b7cd8aa527f22d104dfdad78437fe_img.jpg) + +Existing kiosk                      Kiosk with digital human +F.748.30(24) + +Figure I.3: A diagram comparing an 'Existing kiosk' (a person interacting with a touch screen) to a 'Kiosk with digital human' (three screens showing different digital human avatars). The text 'F.748.30(24)' is at the bottom right. + +**Figure I.3 – An example of the usage of a digital human in customer service industry** + +#### I.3.2 Video-based emotion enabled chatting + +CSDHs as video-based emotion enabled chatting, described in Figure 4(b-2), can be utilized in the following use case. + +- Psychological counselling + +Digital humans can be used for medical or psychotherapeutic purposes. For ongoing counselling, the digital human must remember conversations with the end-user. End users can feel psychological stability through conversations with digital humans, as digital humans and end-users have emotional interactions. Service-specific requirements are described in [ITU-T H.862.6]. + +### **I.4 Digital human and digital human communication** + +CSDHs may serve communication between people in the virtual worlds using digital humans as the mean. + +#### **I.4.1 Non-immersive services** + +CSDHs providing non-immersive services, described in Figure 4(c-1), can be utilized in the following use case. + +##### - Group chat + +Participants to a group chat may decide to talk using a digital human, either to be anonymous or to be displayed with a desired appearance. Such participant may deploy a digital human and control it imitatively to hide from the other participants. + +Chat groups are often maintained with specific themes. Participants in an event chat may want to decorate their digital humans to fit the theme. In a role-playing chat, participants may even want to become a specific character. Digital humans used in this chat would make the participants more immersive. + +#### **I.4.2 Immersive services** + +CSDHs providing immersive services, described in Figure 4(c-2), can be utilized in the following use case. + +##### - VR multiplayer games + +In VR games, participants may meet as teammates or opponents to achieve a goal on the virtual world. Participants have to strategically control their digital humans and interact with the environment to be victorious in the game, while communicating with the other participants. + +## Bibliography + +- [b-ITU-T F.702] Recommendation ITU-T F.702 (1996), *Multimedia conference services*. +- [b-ITU-T F.744.2] Recommendation ITU-T F.744.2 (2018), *Framework and interfaces for multimedia content delivery network*. +- [b-ITU-T F.746.3] Recommendation ITU-T F.746.3 (2015), *Intelligent question answering service framework*. +- [b-ITU-T F.748.14] Recommendation ITU-T F.748.14 (2022), *Requirements and evaluation methods of non-interactive 2D real-person digital human application systems*. +- [b-ITU-T H.780] Recommendation ITU-T H.780 (2012), *Digital signage: Service requirements and IPTV-based architecture*. +- [b-ITU-T P.1320] Recommendation ITU-T P.1320 (2022), *Quality of experience assessment of extended reality meetings*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git 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algorithm scheduling systems** + +![ITU logo](390120de4fe440c42fea8154fcaad334_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.748.36 + +## Requirements and framework of multi-algorithm scheduling systems + +## Summary + +Recommendation ITU-T F.748.36 specifies the requirements and framework of the multi-algorithm scheduling (MAS) systems for artificial intelligence (AI)-based multimedia applications. The MAS systems consist of the scheduling unit, the algorithm warehouse unit and the computing power resource management unit. The MAS systems schedule multiple algorithms (multi-type, multi-version or from multiple providers) across heterogeneous computing power resources based on specific tasks on-demand. This Recommendation is intended to guide the design, development, application and implementation of MAS systems for AI-based multimedia applications. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.748.36 | 2024-06-13 | 16 | 11.1002/1000/15915 | + +## Keywords + +Algorithm warehouse, artificial intelligence, computing power resource, framework, multi-algorithm scheduling, multimedia, requirements. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2024 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|--------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Overview of multi-algorithm scheduling systems..... | 2 | +| 7 Framework of multi-algorithm scheduling systems ..... | 4 | +| 8 Requirements of multi-algorithm scheduling systems ..... | 5 | +| 8.1 General requirements..... | 5 | +| 8.2 Requirements of scheduling unit ..... | 5 | +| 8.3 Requirements of algorithm warehouse unit..... | 6 | +| 8.4 Requirements of computing power resource management unit ..... | 7 | +| Bibliography..... | 8 | + + + +## Requirements and framework of multi-algorithm scheduling systems + +## 1 Scope + +This Recommendation specifies the requirements and framework of the multi-algorithm scheduling (MAS) systems for artificial intelligence-based multimedia applications. + +The scope of this Recommendation includes: + +- Overview of MAS systems; +- Framework of MAS systems; and +- Requirements of MAS systems. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 algorithm** [b-ISO/IEC 11557]: A set of rules for transforming the logical representation of data. + +**3.1.2 artificial intelligence** [b-ISO/IEC 2382]: Interdisciplinary field, usually regarded as a branch of computer science, dealing with models and systems for the performance of functions generally associated with human intelligence, such as reasoning and learning. + +**3.1.3 process instance** [b-ISO/IEC 33001]: Single specific and identifiable execution of a process. + +**3.1.4 resource** [b-ISO/IEC 2382]: Any element of a data processing system needed to perform required operations. + +**3.1.5 scheduling** [b-ITU-T X.746]: The method of controlling the timing of the execution of a scheduled activity within or represented by a managed object. + +**3.1.6 virtualization** [b-ISO/IEC 17826]: Presentation of resources as if they are physical, when in fact, they are decoupled from the underlying physical resources. + +### 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 algorithm package**: A set of algorithmic programs and its formal description information that implement specific functions. + +NOTE – The algorithmic program is executable software composed of algorithm and runtime environment. + +**3.2.2 algorithm warehouse:** A system with unified management of algorithm packages, including import, storage, retrieval, download, etc. + +**3.2.3 computing power resource:** A resource that provides data processing and computing capabilities for various applications. + +**3.2.4 multi-algorithm scheduling:** A method that schedules multiple algorithms (multi-type, multi-version or from multiple providers) across heterogeneous computing power resources based on specific tasks on-demand. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|--------------------------------| +| AI | Artificial Intelligence | +| CPU | Central Processing Unit | +| FPGA | Field Programmable Gate Array | +| GPU | Graphics Processing Unit | +| MAS | Multi-algorithm Scheduling | +| NPU | Neural-network Processing Unit | + +# 5 Conventions + +In this Recommendation: + +- The keywords "**is required to**" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. +- The keywords "**is recommended**" indicate a requirement which is recommended but which is not absolutely required. Thus this requirement needs not be present to claim conformance. + +# 6 Overview of multi-algorithm scheduling systems + +With the progressive maturity of artificial intelligence (AI) technology, the intelligent analysis of multimedia data, including video, audio and image, has significantly elevated the level of intelligent application across various industries. This has spurred manufacturers to develop numerous customized algorithms of different types and versions for diverse applications, giving rise to the following challenges: + +- The inconsistent protocol of algorithm interfaces necessitates applications to integrate and adapt to multiple algorithm interfaces, resulting in high development complexity; +- The inconsistent formatting of algorithm descriptions leads to tight coupling between applications and algorithms, hindering dynamic scheduling and flexibility; +- The diversity and fragmentation of algorithm types contribute to high complexity in algorithm management; +- The tight coupling between algorithms and computing power resources prevent the sharing and on-demand scheduling computing power resources, resulting in suboptimal resource utilization. + +Figure 1 shows the conceptual diagram of multi-algorithm scheduling systems. + +![Conceptual diagram of multi-algorithm scheduling systems showing the flow from AI applications through scheduling, algorithm management, and computing power resources to data systems.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +The diagram illustrates the architecture of a multi-algorithm scheduling (MAS) system. At the top, a dashed box labeled "AI multimedia applications" contains "Function A", "Function B", "Function C", and "Function N". A double-headed arrow labeled (3) connects this box to the "Multi-algorithm scheduling systems" box below. Inside the MAS box, a light blue "Scheduling unit" is at the top. Below it, a blue "Algorithm warehouse unit" contains "Algorithm package", "Algorithm package", and "Algorithm package". To the right of the warehouse unit is a purple "Computing power resource management unit". Below these units is a dashed box labeled "Computing power resource pool", which contains three "Computing unit" boxes. Each "Computing unit" contains a "Process instance" and "Computing power". A double-headed arrow labeled (4) connects the "Scheduling unit" to the "Algorithm warehouse unit". A double-headed arrow labeled (5) connects the "Scheduling unit" to the "Computing power resource management unit". A double-headed arrow labeled (1) connects the "Computing power resource management unit" to the "Computing power resource pool". A dashed arrow labeled (6) points from the "Algorithm warehouse unit" to the "Process instance" in the first "Computing unit". External to the MAS box, a dashed box labeled "Algorithm development systems" is connected via a double-headed arrow labeled (2). A dashed box labeled "Data acquisition systems" is connected via a double-headed arrow labeled (7). A dashed box labeled "Data storage systems" is connected via a double-headed arrow labeled (8). The label F.748.36(24) is in the bottom right corner. + +Conceptual diagram of multi-algorithm scheduling systems showing the flow from AI applications through scheduling, algorithm management, and computing power resources to data systems. + +**Figure 1 – Conceptual diagram of multi-algorithm scheduling systems** + +The multi-algorithm scheduling (MAS) systems provide algorithm scheduling capabilities for AI multimedia applications, scheduling multiple algorithms (multi-type, multi-version, or from multiple providers) across heterogeneous computing power resources based on specific tasks on demand. The MAS systems are typically deployed on the cloud. The main capabilities of MAS systems include: + +- **Unified algorithm management:** MAS systems provide a unified algorithm interface and algorithm package format for AI multimedia applications, centralizing the management of multiple algorithms. This resolves complexity arising from algorithm fragmentation, reducing application construction and maintenance costs while enhancing algorithmic ecological integration capabilities; +- **Layered decoupling and intelligent scheduling:** MAS systems achieve decoupling of applications and algorithms through multi-algorithm dynamic scheduling; The MAS systems scheduling algorithms based on computing power resources pooling and virtualization, enabling decoupling between algorithms and computing power resources, flexible allocation and recycling of computing power resources, and maximizing resource utilization and application efficiency. + +MAS systems consist of the scheduling unit, the algorithm warehouse unit and the computing power resource management unit. + +The scheduling unit uniformly schedules algorithm packages in the algorithm warehouse, manages scheduling strategies, manages scheduling tasks and monitors the execution status of scheduling tasks. The scheduling unit selects appropriate algorithm packages and deploys them to the computing power resources based on the requirements of the tasks and the operation status of the computing power resources. The scheduling unit monitors the execution of scheduling tasks, handles abnormal tasks according to pre-set strategies and pushes the computed results to the target systems. + +The algorithm warehouse unit manages and stores the algorithm packages, and describes the name, type, function, running environment and other characteristics of the algorithm packages. The algorithm warehouse unit operates and manages algorithm packages, providing users with reports on the usage of algorithm packages. + +The computing power resource management unit uniformly manages computing power resources, monitors and maintains their usage and status, provides virtualization, pooling, expansion, and contraction of resources, and manages and monitors process instances generated by the operation of algorithm packages. The computing power resource pool may include central processing unit (CPU), graphics processing unit (GPU), neural-network processing unit (NPU), field programmable gate array (FPGA), etc. + +MAS systems provide algorithm interfaces for various applications of AI multimedia systems, and share and interact data and information with external systems, including algorithm development systems (e.g., algorithm training system [b-ITU-T F.743.22], AI model development cloud platform [b-ITU-T F.748.17]), data acquisition systems (e.g., intelligent video surveillance system [b-ITU-T H.626.5], machine vision system [b-ITU-T F.747.13]) and data storage systems (e.g., cloud storage system [b-ITU-T H.626.2]). + +In Figure 1, the example workflows of scheduling between units within the MAS systems and external systems are as follows: + +NOTE – The arrows connecting each frame signify the conceptual relationship for information exchange. + +Step 1: The computing power resource management unit pools computing power resources to form a computing power resource pool. + +Step 2: The algorithm warehouse unit obtains and stores algorithm packages from local import or from the algorithm development systems. + +Step 3: The scheduling unit receives task information distributed by AI multimedia applications, including task types, data sources, analysis rules, push targets for analysis result, etc. + +Step 4: The scheduling unit obtains matching algorithm package information from the algorithm warehouse unit based on the task types. + +Step 5: The scheduling unit obtains matching computing power resource information from the computing power resource management unit based on the algorithm package running environment. + +Step 6: The scheduling unit forms an algorithm package running mode based on the scheduling strategy, and the algorithm warehouse unit deploys and runs algorithm packages to the computing power resource pool and generates process instances. + +Step 7: Process instances obtain data from the data acquisition systems and perform algorithmic processing of the data according to analysis rules. + +Step 8: Process instances send the computed results to the data storage systems. + +## 7 Framework of multi-algorithm scheduling systems + +Figure 2 shows the framework of multi-algorithm scheduling systems. + +![Figure 2: Framework of multi-algorithm scheduling systems. The diagram shows a hierarchical structure. At the top, a dashed box labeled 'AI multimedia applications' is shown. Below it, a solid box labeled 'Multi-algorithm scheduling systems' contains three main units: 'Scheduling unit', 'Algorithm warehouse unit', and 'Computing power resource management unit'. The 'Scheduling unit' contains 'Strategy management', 'Task management', and 'Task monitoring'. The 'Algorithm warehouse unit' contains 'Algorithm package management', 'Algorithm package storage', and 'Algorithm package retrieval'. The 'Computing power resource management unit' contains 'Expansion and contraction', 'Process instance management', and 'Monitoring and maintenance'. A small label 'F.748.36(24)' is at the bottom right.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +``` + +graph TD + subgraph AI_multimedia_applications [AI multimedia applications] + subgraph Multi_algorithm_scheduling_systems [Multi-algorithm scheduling systems] + subgraph Scheduling_unit [Scheduling unit] + SM[Strategy management] + TM[Task management] + TMon[Task monitoring] + end + subgraph Algorithm_warehouse_unit [Algorithm warehouse unit] + APMan[Algorithm package management] + APS[Algorithm package storage] + APR[Algorithm package retrieval] + end + subgraph Computing_power_resource_management_unit [Computing power resource management unit] + EC[Expansion and contraction] + PIM[Process instance management] + MM[Monitoring and maintenance] + end + end + end + +``` + +Figure 2: Framework of multi-algorithm scheduling systems. The diagram shows a hierarchical structure. At the top, a dashed box labeled 'AI multimedia applications' is shown. Below it, a solid box labeled 'Multi-algorithm scheduling systems' contains three main units: 'Scheduling unit', 'Algorithm warehouse unit', and 'Computing power resource management unit'. The 'Scheduling unit' contains 'Strategy management', 'Task management', and 'Task monitoring'. The 'Algorithm warehouse unit' contains 'Algorithm package management', 'Algorithm package storage', and 'Algorithm package retrieval'. The 'Computing power resource management unit' contains 'Expansion and contraction', 'Process instance management', and 'Monitoring and maintenance'. A small label 'F.748.36(24)' is at the bottom right. + +**Figure 2 – Framework of multi-algorithm scheduling systems** + +NOTE – The dashed frame in Figure 2 indicates that it is not within the scope of this Recommendation. + +The framework of MAS systems consists of the scheduling unit, the algorithm warehouse unit and the computing power resource management unit. + +The scheduling unit consists of strategy management, task management and task monitoring. The requirements of the scheduling unit are specified in clause 8.2. + +The algorithm warehouse unit consists of algorithm package management, algorithm package storage and algorithm package retrieval. The requirements of the algorithm warehouse unit are specified in clause 8.3. + +The computing power resource management unit consists of expansion and contraction, process instance management, and monitoring and maintenance. The requirements of the computing power resource management unit are specified in clause 8.4. + +At the same time, the MAS systems can interact with AI multimedia applications. + +# 8 Requirements of multi-algorithm scheduling systems + +### 8.1 General requirements + +The general requirements of a MAS system include: + +- It is required to support open service capabilities, including but not limited to algorithm package import, algorithm package retrieval, algorithm package download and task management. +- It is required to support the configuration and retrieval of algorithm authorization information, including but not limited to authorization service addresses, and authorization methods. +- It is required to support multiple algorithm authorization methods, including but not limited to non-authorization, local authorization and remote authorization. +- It is recommended to support role-based access control mode. + +### 8.2 Requirements of scheduling unit + +#### 8.2.1 Strategy management + +The requirements of scheduling strategy management include: + +- It is required to support the management of scheduling strategies, including adding, deleting, modifying and retrieving. +- It is required to support starting and stopping of scheduling strategies. +- It is recommended to support scheduling strategies generation based on conditions, including but not limited to time priority, task priority and user priority. +- It is recommended to support automatic optimization of scheduling strategies. + +#### **8.2.2 Task management** + +The requirements of scheduling task management include: + +- It is required to support the management of tasks, including adding, deleting, modifying and retrieving. +- It is required to support multiple types of tasks, including but not limited to synchronous mode and asynchronous mode. +- It is required to support the status retrieval of tasks. +- It is required to support splitting and merging of tasks. +- It is required to support the migration of tasks. +- It is required to support starting, pausing, resuming and stopping of tasks. + +#### **8.2.3 Task monitoring** + +The requirements of scheduling task monitoring include: + +- It is required to support the monitoring of task execution status. +- It is required to support statistical analysis of task execution status, including but not limited to task anomaly rate, task online rate and task execution duration. + +### **8.3 Requirements of algorithm warehouse unit** + +#### **8.3.1 Algorithm package management** + +The requirements of algorithm package management include: + +- It is required to support the management of algorithm packages, including import, update, deletion and distribution. +- It is required to support admission verification of algorithm package format. +- It is required to support statistical analysis of algorithm package information, including but not limited to usage times, usage frequency and usage period. + +#### **8.3.2 Algorithm package storage** + +The requirements of algorithm package storage include: + +- It is required to support full storage of algorithm packages. +- It is recommended to support incremental storage of algorithm packages. +- It is recommended to support encrypted storage of algorithm packages. +- It is recommended to support tiered storage based on algorithm packet usage frequency. + +#### **8.3.3 Algorithm package retrieval** + +The requirements of algorithm package retrieval include: + +- It is required to support algorithm package retrieval based on keywords. +- It is required to support algorithm package retrieval based on multiple combinations of conditions, including but not limited to data source types and algorithm package types. + +### **8.4 Requirements of computing power resource management unit** + +#### **8.4.1 General requirements** + +The general requirements of computing power resource management include: + +- It is required to support retrieval and statistical analysis of computing power resources. +- It is required to support multiple types of AI accelerator, including but not limited to GPU, NPU and FPGA. +- It is required to support computing power resources usage and recovery based on task requirements. +- It is required to support computing power resources isolation based on users. +- It is recommended to support quota management of computing power resources. +- It is recommended to support energy consumption management capabilities of computing power resources, including but not limited to resource shutdown and resource hibernation. + +#### **8.4.2 Expansion and contraction** + +The requirements of computing power resource expansion and contraction include: + +- It is required to support self-discovery of computing power resources. +- It is required to support the addition and deletion of computing power resources. +- It is required to support virtualization and pooling of computing power resources. + +NOTE – Through splitting, allocating and integrating heterogeneous computing power resources from a computing power resource pool. + +- It is recommended to support elastic expansion and contraction of computing power resources based on task requirements. + +#### **8.4.3 Process instance management** + +The requirements of process instance management include: + +- It is required to support the management of process instances, including addition, deletion, modification and retrieving. +- It is required to support starting, pausing, resuming and stopping of process instances. +- It is required to support statistical analysis of computing power resources usage for different process instances. +- It is recommended to support process instance execution based on containers. + +#### **8.4.4 Monitoring and maintenance** + +The requirements of computing power resource monitoring and maintenance include: + +- It is required to support real-time monitoring of computing power resources status and usage, including but not limited to resource utilization and performance fluctuation status. +- It is recommended to support fault detection, alarm, isolation and restoration of computing power resources. +- It is recommended to support the self-maintenance of computing power resources. + +## Bibliography + +- [b-ITU-T F.743.22] Recommendation ITU-T F.743.22 (2022), *Requirements and architecture of an algorithm-training system for intelligent video surveillance.* +- [b-ITU-T F.747.13] Recommendation ITU-T F.747.13 (2023), *Requirements and reference framework of cloud-edge collaboration in industrial machine vision systems.* +- [b-ITU-T F.748.17] Recommendation ITU-T F.748.17 (2022), *Technical specification for artificial intelligence cloud platform – Artificial intelligence model development.* +- [b-ITU-T H.626.2] Recommendation ITU-T H.626.2 (2017), *Architecture for cloud storage in visual surveillance.* +- [b-ITU-T H.626.5] Recommendation ITU-T H.626.5 (2022), *Architecture for intelligent video surveillance systems.* +- [b-ITU-T X.746] Recommendation ITU-T X.746 (2000), *Information technology – Open Systems Interconnection – Systems management: Scheduling function.* +- [b-ISO/IEC 11557] ISO/IEC 11557:1992, *Information technology – 3,81 mm wide magnetic tape cartridge for information interchange – Helical scan recording – DDS-DC format using 60 m and 90 m length tapes.* + +- [b-ISO/IEC 17826] ISO/IEC 17826:2022, *Information technology – Cloud Data Management Interface (CDMI) Version 2.0.0.* + +- [b-ISO/IEC 2382] ISO/IEC 2382:2015, *Information technology – Vocabulary.* + +- [b-ISO/IEC 33001] ISO/IEC 33001:2015, *Information technology – Process assessment – Concepts and terminology.* + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.748.37-202406-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg b/marked/F/T-REC-F.748.37-202406-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg new file mode 100644 index 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sha256:92d8dd8742bff59b4561e33b54e4f2183d36264768568cd6396060b950bd2b09 +size 75301 diff --git a/marked/F/T-REC-F.748.37-202406-I_PDF-E/raw.md b/marked/F/T-REC-F.748.37-202406-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..a60dcc9468d06ec1a5d108197c95db68a49d496a --- /dev/null +++ b/marked/F/T-REC-F.748.37-202406-I_PDF-E/raw.md @@ -0,0 +1,539 @@ + + +# Recommendation **ITU-T F.748.37 (06/2024)** + +SERIES F: Non-telephone telecommunication services + +Multimedia services + +--- + +## **Requirements and functional framework of joint semantic query system of unstructured data across clusters** + +![ITU logo](0538daaa5583c23e17db3a12f2281a55_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with white lines representing latitude and longitude, and the letters 'ITU' in a bold, blue, sans-serif font superimposed on the globe. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.748.37 + +# Requirements and functional framework of joint semantic query system of unstructured data across clusters + +## Summary + +Recommendation ITU-T F.748.37 specifies the requirements and framework for a joint semantic query system of unstructured data across clusters, enabling efficient and rapid queries of unstructured data without changing the physical location of the data. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.748.37 | 2024-06-13 | 16 | 11.1002/1000/15916 | + +## Keywords + +Clusters, fusion, semantic query, unstructured data. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2024 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +###### Page + +| | | | +|------------|--------------------------------------------------------------------------------------|----| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| 3.1 | Terms defined elsewhere ..... | 1 | +| 3.2 | Terms defined in this Recommendation..... | 1 | +| 4 | Abbreviations and acronyms ..... | 1 | +| 5 | Conventions ..... | 2 | +| 6 | Overview ..... | 2 | +| 7 | Framework for system of joint semantic query of unstructured data across clusters... | 3 | +| 8 | Functional requirements ..... | 4 | +| 8.1 | Functional requirements for the data module..... | 4 | +| 8.2 | Functional requirements for feature extraction module ..... | 5 | +| 8.3 | Functional requirements for feature storage module..... | 7 | +| 8.4 | Functional requirements for fusion module ..... | 7 | +| 9 | Security consideration ..... | 8 | +| 9.1 | Overall security requirements..... | 8 | +| 9.2 | Security requirements for retrieval..... | 8 | +| 9.3 | Security requirements for fusion ..... | 9 | +| Appendix I | – Use case and workflow for cross-cluster joint query of image data ..... | 10 | +| I.1 | Key stakeholders ..... | 10 | +| I.2 | Prerequisites ..... | 10 | +| I.3 | Workflow..... | 10 | +| | Bibliography..... | 12 | + + + +# Recommendation ITU-T F.748.37 + +# Requirements and functional framework of joint semantic query system of unstructured data across clusters + +# 1 Scope + +This Recommendation provides an overview of a joint semantic query system of unstructured data across clusters, and specifies its requirements and functional framework. + +The scope of this Recommendation includes: + +- Overview; +- Framework of a system for joint semantic query of unstructured data across clusters; +- Functional requirements of a system for joint semantic query of unstructured data across clusters. + +Appendix I provides a use case and workflow for cross-cluster joint semantic query of image data. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 cluster** [b-ITU-T Y.2019]: Cluster is a grouping of content delivery processing entities with their related control entity. Such grouping allows the sharing of resources (e.g., storage capacity) based on provider's policy (e.g., taking into account parameters such as user location). + +**3.1.2 semantics** [b-ITU-T Z.341]: The rules and conventions governing the interpretation and assignment of meaning to constructions in a language. + +## 3.2 Terms defined in this Recommendation + +None. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|------------------------------| +| AI | Artificial Intelligence | +| CNN | Convolutional Neural Network | +| HTML | Hypertext Mark-up Language | +| ID | Identity | + +| | | +|------|------------------------------| +| JSON | JavaScript Object Notation | +| STFT | Short-Time Fourier Transform | + +# 5 Conventions + +In this Recommendation: + +- The keywords "**is required to**" indicate a requirement which must be strictly followed and from which no deviation is permitted, if conformance to this Recommendation is to be claimed. +- The keywords "**is recommended**" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +# 6 Overview + +With the development of technology and changes in the way people interact with each other, unstructured data such as pictures, videos, voice and text is growing rapidly and continuously. The amount of unstructured data is very large, and the value contained in unstructured data far exceeds that of structured data. With the widespread use of artificial intelligence (AI) technology, the analysis and processing of unstructured data has become crucial. + +Semantic query focuses on the query of unstructured data and aims to provide accurate and immediate answers to users' questions. Semantic query of unstructured data uses AI-based methods to interpret and search information in text, images and videos more effectively. + +At present, semantic query of unstructured data is facing some challenges. Due to the vast volume of data, the migration cost of unstructured data incurs high costs and raises issues related to transmission security, data integrity and privacy. Due to the problems mentioned above, the joint query and analysis of unstructured data across clusters without moving data will be the development trend of AI and big data governance in the future. + +Cluster generally refers to a group of servers that are physically centralized and unified. Cross-cluster joint semantic query refers to the collaboration of multiple clusters for semantic level query and information extraction. Joint semantic query systems are designed to perform semantic queries across multiple data clusters without the need to move or replicate data. This system aims to understand and extract meaningful relationships and information from unstructured data across different physical locations. + +The user submits an unstructured query request to the central cluster. The central cluster discovers it and distributes this request. Each data cluster, upon receiving the query request, conducts content searches locally and returns the identities (IDs) of the initial search results to the central cluster. The central cluster then fuses the initial results from all the data clusters to compile and return the final search result to the user. + +The relationship between the users and the system is shown in Figure 1. + +![Diagram illustrating the relationship between the user/demand side and the joint semantic query system. The user side includes 'Unstructured query requirement' and 'The final result'. The system side includes 'Central cluster', 'Discover', 'Distribute', 'Record', and 'Fusion'. Below this, a 'Joint semantic query system' contains 'Data cluster 1', 'Data cluster 2', and 'Data cluster 3' (labeled 'Register'), each associated with a 'Query'. Arrows show the flow from user requirement to central cluster, then to discover and distribute. Distribute sends 'Unstructured query content' to the data clusters. The data clusters send 'The initial search result' to the fusion module. Fusion sends a 'Result' to the record, which then leads to 'The final result' on the user side.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +F.748.37(24) + +Diagram illustrating the relationship between the user/demand side and the joint semantic query system. The user side includes 'Unstructured query requirement' and 'The final result'. The system side includes 'Central cluster', 'Discover', 'Distribute', 'Record', and 'Fusion'. Below this, a 'Joint semantic query system' contains 'Data cluster 1', 'Data cluster 2', and 'Data cluster 3' (labeled 'Register'), each associated with a 'Query'. Arrows show the flow from user requirement to central cluster, then to discover and distribute. Distribute sends 'Unstructured query content' to the data clusters. The data clusters send 'The initial search result' to the fusion module. Fusion sends a 'Result' to the record, which then leads to 'The final result' on the user side. + +**Figure 1 – The relationship between the users and the system** + +# 7 Framework for system of joint semantic query of unstructured data across clusters + +The system is divided into four modules: the data module, the feature extraction module, the feature storage module and the fusion module. The data module completes the pre-processing of unstructured data, preparing it for feature extraction. The Feature extraction module primarily extracts features from unstructured data for tasks such as recognition, classification and retrieval of related data. The feature storage module implements efficient storage and indexing. The fusion module securely fuses the search results. + +The framework for system of joint semantic querying of unstructured data across clusters is shown in Figure 2. + +![Figure 2 – Framework for system of joint semantic querying of unstructured data across clusters. The diagram shows a 'Central cluster' on the right with a 'Fusion module' containing 'Register', 'Discover', 'Distribute', 'Retrieval', 'Fusion', and 'Record'. On the left, 'Each data cluster' contains three modules: 'Storage module' (Efficient storage and query, Security and privacy, Scalability and persistence, System integration), 'Feature extraction module' (Text: Dictionary-based, Sentence-based; Image: Image pixel features, Deep learning; Audio: Time-domain, Frequency-domain, Time-frequency domain, Advanced; Video: Static, Dynamic), and 'Data module' (Text query data, Image query data, Audio query data, Video query data, ...).](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +F.748.37(24) + +Figure 2 – Framework for system of joint semantic querying of unstructured data across clusters. The diagram shows a 'Central cluster' on the right with a 'Fusion module' containing 'Register', 'Discover', 'Distribute', 'Retrieval', 'Fusion', and 'Record'. On the left, 'Each data cluster' contains three modules: 'Storage module' (Efficient storage and query, Security and privacy, Scalability and persistence, System integration), 'Feature extraction module' (Text: Dictionary-based, Sentence-based; Image: Image pixel features, Deep learning; Audio: Time-domain, Frequency-domain, Time-frequency domain, Advanced; Video: Static, Dynamic), and 'Data module' (Text query data, Image query data, Audio query data, Video query data, ...). + +**Figure 2 – Framework for system of joint semantic querying of unstructured data across clusters** + +# 8 Functional requirements + +## 8.1 Functional requirements for the data module + +### 8.1.1 Data pre-processing for text data + +For text data, the data pre-processing steps are as follows: + +- a) It is recommended to remove hypertext mark-up language (HTML) tags, special characters, punctuation, etc. +- b) It is recommended to segment the text into words or phrases. +- c) It is recommended to remove common and meaningless words. +- d) It is recommended to convert words to their base forms to reduce vocabulary variety. +- e) It is recommended to transform text into vector representations for computing semantic similarity. + +#### 8.1.2 Data pre-processing for image data + +For image data, the data pre-processing steps are as follows: + +- a) It is recommended to resize images to the same size or to a specific area for processing. +- b) It is recommended to convert colour images to grayscale or perform colour space transformations. +- c) It is recommended to adjust the contrast, brightness and sharpness of images. +- d) It is recommended to use methods such as convolutional neural networks (CNNs) to extract feature representations of images. + +#### **8.1.3 Data pre-processing for audio data** + +For audio data, the data pre-processing steps are follows: + +- a) It is recommended to adjust the sampling rate of audio data to a uniform value. +- b) It is recommended to convert audio signals to spectral representations for extracting sound features. +- c) It is recommended to remove noise from audio signals. + +#### **8.1.4 Data pre-processing for video data** + +For video data, the data pre-processing steps are as follows: + +- a) It is recommended to extract key frames from videos for processing as static images. +- b) It is recommended to segment videos into multiple clips for processing. +- c) It is recommended to use action recognition algorithms to extract motion features from videos. + +## **8.2 Functional requirements for feature extraction module** + +#### **8.2.1 Feature extraction for text data** + +Text data feature extraction involves extracting vectors from text data that can describe the content and features of the text, used for tasks such as text classification, clustering and retrieval. + +Common methods of text data feature extraction are as follows: + +- a) It is recommended to use the method of dictionary-based feature extraction. It encompasses both dictionary methods and word embedding. Dictionary methods map words in the text to a vector space, with each word corresponding to a vector. Word embedding utilize neural networks to learn distributed representations of word vectors, reflecting the semantic relationships between words. +- b) It is recommended to use the method of sentence-based feature extraction. It typically involves sentence vectors, and represents sentences as vectors to reflect their semantic information. + +Among these, vectorization extraction for JavaScript object notation (JSON) data is most typical. It is characterized as follows: + +Before describing, basic conceptual definitions are introduced. The first semi-structured data file refers to the real data file of the actual application scenario. The second semi-structured data file is used for the rule configuration, whose basic framework structure is basically the same as the first semi-structured data file. + +Read the first semi-structured data files to obtain the data to be converted. + +Parse a pre-configured rule file to determine the corresponding relationship between the data to be converted and the fields to be extracted in the rule file. The rule file is a file that includes the first mapping relationship between the fields to be extracted and the data structure of the vector storage middleware, and the second mapping relationship between the fields to be extracted and the vectorization conversion algorithm. + +According to the corresponding relationship and the second mapping relationship, the vector transformation algorithm is called to perform vector transformation on the data to be transformed and store it in the vector storage middleware according to the first mapping relationship. + +The configuration methods of the rule file include the following: + +Determine the hierarchical position and field name of the fields to be extracted based on the second semi-structured data file. + +Establish a rule file including the first mapping relationship between the fields to be extracted and the data structure of the vector storage middleware, as well as the second mapping relationship between the fields to be extracted and the vector transformation algorithm. + +The methods for determining the hierarchical position and field name of the field to be extracted based on the second semi-structured data file includes the following: + +- a) Simplify the data information in the second semi-structured data file and obtain the corresponding basic framework structure of the second semi-structured data file. +- b) Save the basic framework structure as a semi-structured data template. +- c) Determine the hierarchical position and field name of the field to be extracted based on the semi-structured data template. + +#### **8.2.2 Feature extraction for image data** + +Image data feature extraction involves deriving vectors from image data that can describe the content and characteristics of the images. It is used for tasks such as image recognition, classification and retrieval. The following are common recommendations for image data feature extraction: + +- a) It is recommended to use feature extraction based on image pixel characteristics to analyse and capture the colour, texture and shape of an image. +- b) It is recommended to employ deep learning for feature extraction to analyse image pixels and extract characteristics related to colour, texture and shape. + +#### **8.2.3 Feature extraction for audio data** + +Audio data feature extraction involves deriving vectors from audio signals that describe the content and characteristics of the audio. The vectors are used for tasks such as audio recognition, classification and retrieval. + +The following are common recommendations for audio data feature extraction: + +- a) It is recommended to perform time-domain feature extraction to analyse attributes such as amplitude, energy and zero-crossing rate in audio signals over time. +- b) It is recommended to apply frequency-domain feature extraction, typically using a Fourier Transform, to analyse the distribution of audio signals in the frequency domain. +- c) It is recommended to conduct time-frequency domain feature extraction by using a short-time Fourier transform (STFT) to describe changes in audio signals across both time and frequency dimensions. +- d) It is recommended to utilize advanced feature extraction techniques that build on time, frequency, or time-frequency domain features for specialized applications such as speech recognition or music analysis. + +#### **8.2.4 Feature extraction for video data** + +Video data feature extraction involves deriving vectors from video data that describe the content and characteristics of the videos. These vectors are used for tasks such as video recognition, classification and retrieval. Video data feature extraction can be divided into two categories: static and dynamic. Static feature extraction extracts features from each frame of the video, akin to image feature extraction. Dynamic feature extraction, on the other hand, extracts features from a sequence of continuous frames to capture changes in video content. + +Common methods for static feature extraction are similar to those used in image data feature extraction. + +The following are common recommendations for dynamic feature extraction: + +- a) It is recommended to use optical flow to calculate the movement of pixels between consecutive video frames. +- b) It is recommended to perform motion trajectory analysis to track the movement paths of objects across video frames. +- c) It is recommended to implement action recognition to identify human actions in a video while maintaining anonymity. +- d) It is recommended to conduct event recognition to identify significant events occurring within a video. + +## 8.3 Functional requirements for feature storage module + +The functional requirements of the storage module include the following: + +- a) It is required to provide data redundancy storage and backup mechanisms to ensure data persistence and fault tolerance. +- b) It is required to implement data encryption storage and access control to protect data privacy. +- c) It is recommended to design the system to support the growth of data volume and the addition of new data types. +- d) It is recommended to offer flexible system interfaces to facilitate integration with other systems or modules. + +## 8.4 Functional requirements for fusion module + +#### 8.4.1 Division of roles + +Divided by roles, the system includes a central node and multiple edge nodes connected to the central node. The relationship of the main roles in the system is shown in Figure 2. + +![Diagram illustrating the relationships of the main roles in the system. A central node (Central cluster) is connected to multiple edge nodes (Data clusters A, B, and C). The central node has four functional blocks: Discover, Distribution, Fusion, and Record. The edge nodes are labeled Cluster A, Cluster B, and Cluster C, each containing five vertical bars representing data. Arrows show the flow of requests and results between the central node and the edge nodes, and between the user and the central node.](4636adff5682a064f0ae5f13a1d464a6_img.jpg) + +The diagram illustrates the system architecture. At the top, a 'Central cluster' (dashed box) contains a 'Central node' which oversees four functions: 'Discover', 'Distribution', 'Fusion', and 'Record'. Below this, three 'Data clusters' (labeled 'Cluster A', 'Cluster B', and 'Cluster C') are shown. Each data cluster contains five vertical bars representing data. Each data cluster has a 'Register' arrow pointing to the central node. Between each data cluster and the central node, there are 'Request' and 'Result' arrows. On the left, a user icon has 'Request' and 'Result' arrows connecting to the central node. The text 'F.748.37(24)' is in the bottom right corner. + +Diagram illustrating the relationships of the main roles in the system. A central node (Central cluster) is connected to multiple edge nodes (Data clusters A, B, and C). The central node has four functional blocks: Discover, Distribution, Fusion, and Record. The edge nodes are labeled Cluster A, Cluster B, and Cluster C, each containing five vertical bars representing data. Arrows show the flow of requests and results between the central node and the edge nodes, and between the user and the central node. + +**Figure 3 – Relationships of the main roles in the system** + +The division of roles and the introduction of functional relationships: + +- a) Edge nodes are located in different regions and register with the central node. +- b) Type of business needs to be included in the registration information to identify the purpose of their data. + +- c) The central node obtains the type of business corresponding to the information to be queried, and determines multiple target edge nodes corresponding to the type of business from the edge nodes. +- d) The central node sends the information to be queried to each target edge node. +- e) Each target edge node queries and gets the candidate data related to the information to be queried in the locally stored data set. +- f) Each target edge node sends the query results including the candidate data to the central node respectively. +- g) The central node aggregates the query results corresponding to each target edge node to obtain the final query results. + +#### **8.4.2 Functional requirements of the central node** + +The central node mainly includes the following four functional modules: + +- a) Determination module: It is used to control the central node to obtain the type of business corresponding to the information to be queried. The target edge node corresponding to the type of business is determined from the multiple edge nodes. The registration information of each target edge node includes the type of business. +- b) Distribution module: It is used to control the central node to send the information to each target edge node. Each target edge node is located in different regions. +- c) Retrieval module: It is used to control each target edge node to query in the locally stored data set based on the information to be queried, and each target edge node sends the obtained query results to the central node. +- d) Fusion module: It is used to control the central node to integrate the query results corresponding to each target edge node to obtain the final query results. + +#### **8.4.3 Functional requirements of edge nodes** + +The edge node includes the following three functional modules: + +- a) Registration module: Registers the business information of the data to the central node. +- b) Data module: Including data pre-processing, information extraction and information storage. Vectorization and scalarization of internal data are carried out in advance, and indexes are established to improve the efficiency of data retrieval. For the accuracy of data, there is no limit to the methods of each edge node in the process of data vectorization and scalarization, but they need to be unified. +- c) Retrieval module: According to the content sent by the central node, the model retrieves the data and returns the results to the central node. + +# **9 Security consideration** + +## **9.1 Overall security requirements** + +To ensure data security, the overall security requirements include: + +Encrypt the content to be retrieved in the trusted execution environment of the central cluster. Distribute the encrypted content to be retrieved to multiple data clusters and perform encrypted content retrieval in the trusted execution environment of each data cluster. Merge the initial search results returned by each data cluster to determine the final search result. + +## **9.2 Security requirements for retrieval** + +The security requirements for encrypting the content to be retrieved in the trusted execution environment created in the central cluster include: + +Generate public and private keys within the trusted execution environment of the central cluster. Encrypt the content to be retrieved using the public key. Decrypt the encrypted content to be retrieved using the private key within the trusted execution environment of each data cluster to obtain the decrypted initial search results. + +## **9.3 Security requirements for fusion** + +The fusion of the initial search results returned by multiple data clusters to determine the final search result includes the following security requirements: + +The central cluster receives the encrypted initial search results returned by multiple data clusters. Encrypt the initial search results using public keys within the trusted execution environment of each data cluster. Decrypt the encrypted initial search results using the private key within the trusted execution environment of the central cluster, thereby obtaining the decrypted initial search results. + +# Appendix I + +## Use case and workflow for cross-cluster joint query of image data + +(This appendix does not form an integral part of this Recommendation.) + +The typical use case of cross-cluster joint query of image data is shown in Figure I.1. + +![Schematic diagram of cross-cluster semantic query of image data](16152cf1d84aea10848758f51a91ff6a_img.jpg) + +The diagram illustrates the workflow for a cross-cluster semantic query of image data. It starts with 'Query content' (a small image of a white dog) being processed into 'Scalar' and 'Vector' components. These are sent as a 'Query request' to a 'Central cluster'. The 'Central cluster' then uses a 'Distribute' function to send the request to three 'Data cluster' units (Data cluster 1, Data cluster 2, and Data cluster 3). Each data cluster returns a 'Result' (indicated by a magnifying glass icon). The 'Central cluster' also receives 'Record' stacks from the data clusters. These records are processed through a 'Fusion' function, which produces a final 'Result' table. The 'Central cluster' also sends a 'Result' back to the 'Query content'. + +The final 'Result' table from the Fusion function is: + +| | | +|------|------------| +| 1.36 | C1*****001 | +| 4.32 | B1*****001 | +| 5.39 | B1*****002 | + +The results from the data clusters are: + +- Data cluster 1: + +| | | +|-------|------------| +| 5.42 | A1*****001 | +| 7.32 | A1*****002 | +| 10.32 | A1*****003 | +- Data cluster 2: + +| | | +|-------|------------| +| 4.32 | B1*****001 | +| 5.39 | B1*****002 | +| 15.36 | B1*****003 | +- Data cluster 3: + +| | | +|-------|------------| +| 1.36 | C1*****001 | +| 15.69 | C1*****002 | +| 18.67 | C1*****003 | + +F.748.37(24) + +Schematic diagram of cross-cluster semantic query of image data + +Figure I.1 – Schematic diagram of cross-cluster semantic query of image data + +## I.1 Key stakeholders + +- Search users: Responsible for putting forward search needs. +- Data cluster: Responsible for the calculation part of the whole system. Its core function is to search for the closest and most similar content with the input picture. In order to respond to the query in real time, the data needs to be trained and indexed in advance. +- Central cluster: It is responsible for discovering requests from retrieval users, distributing the requests to the data cluster and fusing the final results. + +## I.2 Prerequisites + +Users are required to be registered and have valid login credentials. Clusters that participate in system computing must be registered in the central cluster. + +## I.3 Workflow + +The workflow of cross-cluster semantic query of image data is shown as Figure I.2. + +![Flowchart of the workflow of cross-cluster semantic query of image data. The process starts with '1. Log in (User)' leading to '2. Send request (User)'. '2. Send request (User)' leads to '3. Discover and distribute (Central cluster)'. '3. Discover and distribute (Central cluster)' leads to '4. Retrieval and return initial result (Data cluster)'. '4. Retrieval and return initial result (Data cluster)' leads to '5. Fusion (Central cluster)'. '5. Fusion (Central cluster)' leads to '6. Record (Central cluster)'. '6. Record (Central cluster)' leads to '7. Return the final result (Central cluster)'. A small label 'F.748.37(24)' is located below step 6.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg) + +``` + +graph TD + 1[1. Log in (User)] --> 2[2. Send request (User)] + 2 --> 3[3. Discover and distribute (Central cluster)] + 3 --> 4[4. Retrieval and return initial result (Data cluster)] + 4 --> 5[5. Fusion (Central cluster)] + 5 --> 6[6. Record (Central cluster)] + 6 --> 7[7. Return the final result (Central cluster)] + style 1 fill:none,stroke:none + style 2 fill:none,stroke:none + style 3 fill:none,stroke:none + style 4 fill:none,stroke:none + style 5 fill:none,stroke:none + style 6 fill:none,stroke:none + style 7 fill:none,stroke:none + +``` + +F.748.37(24) + +Flowchart of the workflow of cross-cluster semantic query of image data. The process starts with '1. Log in (User)' leading to '2. Send request (User)'. '2. Send request (User)' leads to '3. Discover and distribute (Central cluster)'. '3. Discover and distribute (Central cluster)' leads to '4. Retrieval and return initial result (Data cluster)'. '4. Retrieval and return initial result (Data cluster)' leads to '5. Fusion (Central cluster)'. '5. Fusion (Central cluster)' leads to '6. Record (Central cluster)'. '6. Record (Central cluster)' leads to '7. Return the final result (Central cluster)'. A small label 'F.748.37(24)' is located below step 6. + +**Figure I.2 – Workflow of cross-cluster semantic query of image data** + +Step 1: The user uses their credentials to log in to the system. + +Step 2: The user extracts the image feature and sends a search request to the central cluster. + +Step 3: The central cluster discovers the request and distributes it to the registered data cluster. + +Step 4: The data cluster receives the search content distributed by the central cluster, carries out data retrieval within the cluster, and returns the initial search result to the central cluster. + +Step 5: The central cluster accepts the returned results of the data cluster and fusion to get the final search results. + +Step 6: In the final return result of each central cluster record, the contribution degree of each data cluster can be extended again based on the contribution degree, such as increasing the incentive mechanism and realizing the value of data. + +Step 7: The central cluster returns the final search result to the user, and the search result is the ID of similar pictures. + +# Bibliography + +- [b-ITU-T Y.2019] Recommendation ITU-T Y.2019 (2010), *Content delivery functional architecture in NGN*. +- [b-ITU-T Z.341] Recommendation ITU-T Z.341(1988), *Glossary of terms*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.748.38-202406-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg b/marked/F/T-REC-F.748.38-202406-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d4d8969f805414689ab79cfd08c333d454d482b3 --- /dev/null +++ b/marked/F/T-REC-F.748.38-202406-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:636c3839edff955a5b6208530b05fa1c983ab153d90f00216517a7a99478b988 +size 7074 diff --git a/marked/F/T-REC-F.748.38-202406-I_PDF-E/c0e88e4bd3a209b66ee7cb67e1cec2be_img.jpg b/marked/F/T-REC-F.748.38-202406-I_PDF-E/c0e88e4bd3a209b66ee7cb67e1cec2be_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8a4738155e0cfabc113cf7f6bc166ae4feb3798c --- /dev/null +++ b/marked/F/T-REC-F.748.38-202406-I_PDF-E/c0e88e4bd3a209b66ee7cb67e1cec2be_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:a9be61edba9c33291fcbfa29ffa72c99d32a3a6d465cff44617455c482a89864 +size 114936 diff --git a/marked/F/T-REC-F.748.38-202406-I_PDF-E/raw.md b/marked/F/T-REC-F.748.38-202406-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..aa926dc5ab52c64606b09ed816ed84da9e5d1563 --- /dev/null +++ b/marked/F/T-REC-F.748.38-202406-I_PDF-E/raw.md @@ -0,0 +1,461 @@ + + +# Recommendation **ITU-T F.748.38 (06/2024)** + +SERIES F: Non-telephone telecommunication services + +Multimedia services + +# --- **Technical specification for artificial intelligence cloud platform: General architecture** + +![ITU logo](0538daaa5583c23e17db3a12f2281a55_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.748.38 + +# Technical specification for artificial intelligence cloud platform: General architecture + +## Summary + +Recommendation ITU-T F.748.38 provides technical specifications and capability requirements for artificial intelligence cloud platform. It specifies the capabilities of artificial intelligence cloud platforms from service providers in the following six aspects: resource management, model development, model deployment, high availability, performance and platform security. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.748.38 | 2024-06-13 | 16 | 11.1002/1000/15917 | + +## Keywords + +Artificial intelligence, cloud computing, distributed machine learning, high availability, machine learning, platform security, resource scheduling. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2024 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +###### Page + +| | | | +|------|---------------------------------------------------------------------|---| +| 1 | Scope..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| 3.1 | Terms defined elsewhere ..... | 1 | +| 3.2 | Terms defined in this Recommendation..... | 1 | +| 4 | Abbreviations and acronyms ..... | 1 | +| 5 | Conventions ..... | 2 | +| 6 | General architecture of artificial intelligence cloud platform..... | 2 | +| 7 | Resource management ..... | 2 | +| 7.1 | Basic resource management ..... | 2 | +| 7.2 | Resource scheduling..... | 3 | +| 7.3 | Heterogeneous computing ..... | 3 | +| 8 | Model development ..... | 3 | +| 8.1 | Data pre-processing ..... | 3 | +| 8.2 | Algorithm development..... | 3 | +| 8.3 | Model training ..... | 3 | +| 8.4 | Visualization..... | 4 | +| 8.5 | Model management ..... | 4 | +| 9 | Model deployment ..... | 4 | +| 9.1 | Model inference..... | 4 | +| 9.2 | Service management..... | 4 | +| 9.3 | Distributed serving ..... | 4 | +| 9.4 | Service scheduling..... | 4 | +| 9.5 | Version control ..... | 5 | +| 10 | High availability ..... | 5 | +| 10.1 | Breakpoint recovery ..... | 5 | +| 10.2 | Auto saving..... | 5 | +| 10.3 | Monitoring..... | 5 | +| 11 | Performance ..... | 5 | +| 11.1 | Training performance ..... | 5 | +| 11.2 | Inference performance..... | 6 | +| 11.3 | Cluster speed-up ..... | 6 | +| 11.4 | Exchange latency..... | 6 | +| 12 | Platform security..... | 6 | +| 12.1 | User authentication..... | 6 | +| 12.2 | Access control ..... | 6 | +| 12.3 | Log audit..... | 7 | + + + +# Technical specification for artificial intelligence cloud platform: General architecture + +# 1 Scope + +This Recommendation focuses on technical specifications and capability requirements of artificial intelligence cloud platform. It is suitable for guiding cloud vendors to build machine learning service specifications and providing references for enterprise users to select artificial intelligence cloud products. The Recommendation includes six aspects: resource management, model development, model deployment, high availability, performance and platform security. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 machine learning** [b-ITU-T Y.3172]: Processes that enable computational systems to understand data and gain knowledge from it without necessarily being explicitly programmed. + +**3.1.2 machine learning model** [b-ITU-T Y.3172]: Model created by applying machine learning techniques to data to learn from. + +## 3.2 Terms defined in this Recommendation + +None. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|-----------------------------------------| +| ASIC | Application Specific Integrated Circuit | +| CPU | Central Processing Unit | +| FPGA | Field Programmable Gate Array | +| GPU | Graphics Processing Unit | +| IaaS | Infrastructure as a Service | +| ONNX | Open Neural Network Exchange | +| PMML | Predictive Model Markup Language | + +# 5 Conventions + +The following conventions are used in this Recommendation: + +The keywords "is recommended" indicate a requirement that is recommended, but which is not absolutely required to claim conformance with this Recommendation. + +# 6 General architecture of artificial intelligence cloud platform + +Figure 6-1 shows that the general architecture of artificial intelligence cloud platform consists of platform security, performance, model development, model deployment, resource management and high availability. + +![Diagram of the general architecture of artificial intelligence cloud platform. The architecture is organized into three vertical columns. The left column is 'Platform security' containing 'User authentication', 'Access control', and 'Log audit'. The middle column contains four stacked boxes: 'Performance' (top, with 'Training performance', 'Inference performance', 'Cluster speedup', 'Exchange latency'), 'Model development' (second from top, with 'Data pre-processing', 'Algorithm development', 'Model training', 'Visualization', 'Model management'), 'Model deployment' (third from top, with 'Model inference', 'Service management', 'Distributed serving', 'Service scheduling', 'Version control'), and 'Resource management' (bottom, with 'Basic resource management', 'Resource scheduling', 'Distributed resource scheduling', 'Heterogeneous computing'). The right column is 'High availability' containing 'Breakpoint recovery', 'Auto save', and 'Monitoring'.](c0e88e4bd3a209b66ee7cb67e1cec2be_img.jpg) + +The diagram illustrates the general architecture of an artificial intelligence cloud platform, organized into three main vertical components: + +- Platform security**: + - User authentication + - Access control + - Log audit +- Performance**: + - Training performance + - Inference performance + - Cluster speedup + - Exchange latency +- Model development**: + - Data pre-processing + - Algorithm development + - Model training + - Visualization + - Model management +- Model deployment**: + - Model inference + - Service management + - Distributed serving + - Service scheduling + - Version control +- Resource management**: + - Basic resource management + - Resource scheduling + - Distributed resource scheduling + - Heterogeneous computing +- High availability**: + - Breakpoint recovery + - Auto save + - Monitoring + +Diagram of the general architecture of artificial intelligence cloud platform. The architecture is organized into three vertical columns. The left column is 'Platform security' containing 'User authentication', 'Access control', and 'Log audit'. The middle column contains four stacked boxes: 'Performance' (top, with 'Training performance', 'Inference performance', 'Cluster speedup', 'Exchange latency'), 'Model development' (second from top, with 'Data pre-processing', 'Algorithm development', 'Model training', 'Visualization', 'Model management'), 'Model deployment' (third from top, with 'Model inference', 'Service management', 'Distributed serving', 'Service scheduling', 'Version control'), and 'Resource management' (bottom, with 'Basic resource management', 'Resource scheduling', 'Distributed resource scheduling', 'Heterogeneous computing'). The right column is 'High availability' containing 'Breakpoint recovery', 'Auto save', and 'Monitoring'. + +F.748.38(24) + +Figure 6-1 – General architecture of artificial intelligence cloud platform + +# 7 Resource management + +## 7.1 Basic resource management + +The platform needs to effectively manage the resources that rely on the infrastructure layer (IaaS) to support machine learning model training, inference and other tasks. The platform is recommended to support the following minimum set of features: + +- Support monitoring of the platform IaaS resources, including monitoring of virtual machines, graphics processing units (GPUs), memory, storage and network. +- Support monitoring of customers' container resources, including monitoring of GPUs, memory, storage and network. + +## **7.2 Resource scheduling** + +The platform needs to support user customized configuration during resource creation and modification. Resources can be increased/decreased according to specific tasks, and idle resources can be automatically recovered. The platform is recommended to support the following minimum set of features: + +- a) Allow users to increase/decrease the number of GPUs or the allocation of elastic compute service. +- b) Automatic recovery of idle resource after training or inference session ends. +- c) Scheduling and management of distributed resources, e.g., multi-cluster. +- d) Optimization of distributed computing, e.g., network, transmission, storage, etc. + +## **7.3 Heterogeneous computing** + +The platform needs to process massive data and perform large-scale calculations for training and inferencing machine learning tasks. It needs to support parallel computing with heterogeneous resources in order to accelerate tasks. The platform is recommended to support the following minimum set of features: + +- a) GPU-accelerated computing and GPU resource scheduling. +- b) Field programmable gate array (FPGA)-accelerated computing and FPGA resource scheduling. +- c) Application specific integrated circuit (ASIC)-accelerated computing and ASIC resource scheduling. + +# **8 Model development** + +## **8.1 Data pre-processing** + +The platform is recommended to have certain processing ability for massive data, including support for source data format collection and the whole data processing flow. The platform is recommended to support the following minimum set of efficient data-access strategies: + +- a) Processing of structured or unstructured data, e.g., picture, video, audio, etc. +- b) Mass upload of large-scale data; support breakpoint recovery for data transmission. +- c) Complete data pre-processing flow. + +## **8.2 Algorithm development** + +For flexible model editing, the platform provides management tool of algorithm development, helping reduce the complexity of model development process. The platform is recommended to support the following minimum set of features: + +- a) Development methods in various forms, e.g., drag-and-drop tool, notebook, etc. +- b) Real-time monitoring of performance metrics during model development. +- c) Creation, deletion, start and stop of algorithm services; support service version management. +- d) Query of service history and current status. +- e) Design, publication and utilization of user-customized algorithms, bringing greater flexibility to users. + +## **8.3 Model training** + +The platform is recommended to handle model training tasks in an effective and reliable manner. + +- a) Support training task management, e.g., create, delete, update, retrieve. + +- b) Support real-time monitoring of performance metrics during model training process. +- c) Utilize reliability strategies, e.g., checkpoint, breakpoint recovery, task retry. + +## **8.4 Visualization** + +The platform is recommended to provide visualization charts of models, data and parameters, which is convenient for performance comparison on the user side. + +- a) Support multiple displays of model performance indicators, such as tables and charts. +- b) Support visualization of both structured and unstructured data. + +## **8.5 Model management** + +The platform is recommended to support the following minimum set of model management operations: + +- a) Model creation, storage and deletion. +- b) Display of model performance metrics, e.g., accuracy. +- c) The import and export of model files in common standard formats, e.g., predictive model markup language (PMML), TFserving, open neural network exchange (ONNX), etc. + +# **9 Model deployment** + +## **9.1 Model inference** + +Model deployment is the process of integrating the AI models into production to make decisions on real-world data. The platform is recommended to support the following minimum set of model inference operations: + +- a) Accelerate and standardize the process of model inference. +- b) Build scalable and high-performance services of model inference. + +## **9.2 Service management** + +The platform provides service management components to help users quickly and conveniently complete operations such as the release, deployment of AI models. The platform is recommended to support service management operations. + +Including but not limited to: + +- a) Provides functions of standard API encapsulation. +- b) Supports unified interface to create tasks, start training, model publishing and other functions. + +## **9.3 Distributed serving** + +The platform's distributed scheduling system distributes workflows to different nodes in multiple clusters, providing elastically scalable computing capabilities for model inference. The platform is recommended to support the following minimum set of distributed serving features: + +- a) parallel processing of multiple tasks; +- b) load balancing of distributed tasks. + +## **9.4 Service scheduling** + +The platform is recommended to support the following minimum set of service scheduling features: + +- a) multi-instance concurrent scheduling of models, e.g., batch parameters, manual scheduling, rerun, etc.; +- b) load balancing for service scheduling and elastic scalability of corresponding resources; + +- c) distributed service scheduling strategy. + +## **9.5 Version control** + +The platform is recommended to support the following minimum set of version control operations features: + +- a) service version management, including A/B testing, model rollback, grey released, etc.; +- b) service version management of algorithm services, service history records, query of current status of services, etc. + +# **10 High availability** + +## **10.1 Breakpoint recovery** + +To improve the stability of the training process, the platform is recommended to support saving of the current state if a task is interrupted or stopped accidentally to enable task continuation after state recovery. Support of the following minimum set of features is recommended: + +- a) breakpoint resume; +- b) automatic retries of tasks. + +## **10.2 Auto saving** + +The platform needs to support automatic saving during model building, training and inference, in order to prevent any significant loss caused by mis-operation. Support of the following minimum set of features is recommended: + +- a) Configurable auto-saving policy. + +## **10.3 Monitoring** + +The platform conducts multi-dimensional statistics of basic metrics, such as usage of central processing unit (CPU), memory, network, disk, etc. By accurately reflecting real-time traffic and health status, it provides references for evaluation of resources consumption and service load during a training or inference task. Operations personnel can observe real-time status of the platform, thus improving the efficiency of online operation and maintenance. Support of the following minimum set of features is recommended: + +- a) single task monitoring, including cluster resources consumption and task instance status; +- b) single task life cycle management; +- c) user customized alarm configuration, including methods of alarm notification, e.g., e-mail, short message, etc.; +- d) provide visualization charts of platform operation status and resource utilization status. + +# **11 Performance** + +## **11.1 Training performance** + +Mainly refers to performance indicators of the platform processing model training tasks, providing reference for improvement and optimization of training process. Tracking of the following minimum set of metrics is recommended: + +- a) Platform throughput: the maximum number of tasks that the platform supports for simultaneous training. + +- b) Training speed: the time that the platform takes to complete same training tasks compared with others, the less the better. +- c) Data dimension processing: support data processing for high vector dimension. + +## **11.2 Inference performance** + +Mainly refers to performance indicators of the platform processing model inference tasks, providing reference for improvement and optimization of inference process. Tracking of the following minimum set of metrics is recommended: + +- a) Throughput: the number of queries processed per second. +- b) Delay: the process time of each inference request. +- c) Inference speed: the time that the platform takes to complete same inference tasks compared with others, the less the better. + +## **11.3 Cluster speed-up** + +The platform provides a distributed scheduling strategy to make full use of the advantages of multi-machine and multi-chips in clusters, improving its cluster speed-up ratio. Tracking of the following minimum set of metrics is recommended: + +- a) The ratio between performance growth and resource growth, i.e., the amount of processing acceleration upon increasing computing resources for the task. + +## **11.4 Exchange latency** + +The delay of parameter exchange or data exchange in distributed training should be tracked and the following minimum set of metrics is recommended: + +- a) processing time of parameter exchange; +- b) processing time of data exchange. + +# **12 Platform security** + +## **12.1 User authentication** + +The platform is recommended to utilize access-control methods to ensure the security of the platform. Support of the following minimum set of features is recommended: + +- a) identification and authentication of system users; +- b) definition of password complexity rules and password change frequency; +- c) identification of administrators with two or more verification techniques combined. + +## **12.2 Access control** + +The platform is recommended to achieve resource isolation for different tenants by controlling permissions of different users and roles. Support of the following minimum set of features is recommended: + +- a) security policy-based user access control over data and resource; support application isolation, data isolation, resource isolation and operation isolation among tenants; +- b) role-based user permission authorization; +- c) multi-tenant management; +- d) sensitivity label for important data and resources, and support security policy based strict user operation control over data and resources with sensitivity labels. + +## **12.3 Log audit** + +The platform is recommended to be able to record a series of user operations, and be able to query and display the operation log for debugging and root causing purposes. Support of the following minimum set of features is recommended: + +- a) record and audit of platform tasks; +- b) data analysis and corresponding audit report based on recorded data; +- c) log management system that supports a view of training log and resource usage log, log visualization and log comparison. + +# Bibliography + +- [b-ITU-T Y.3172] Recommendation ITU-T Y.3172 (2019), *Architectural framework for machine learning in future networks including IMT-2020*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | 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It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.748.62 + +# Technical framework and requirements for device-edge-cloud collaborative federated machine learning + +## Summary + +Federated machine learning (FML) allows collaborative model training via parameter exchange, ensuring privacy and compliance. A device-edge-cloud framework, with edge servers as intermediaries, enhances accuracy, resource balance and scalability, requiring standardized protocols plus strategies for resource use, privacy and aggregation. Recommendation ITU-T F.748.62 introduces the framework and requirements for device-edge-cloud collaborative FML, and specifies its concept, procedure, requirements and use cases. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.748.62 | 2025-12-14 | 21 | 11.1002/1000/16587 | + +## Keywords + +Collaborative framework, device-edge-cloud collaboration, federated machine learning. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2026 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|--------------------------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 1 | +| 6 Device-edge-cloud collaborative FML framework ..... | 2 | +| 7 Procedure of device-edge-cloud collaborative FML ..... | 3 | +| 8 Requirements of device-edge-cloud collaborative FML framework..... | 4 | +| 8.1 General requirements of device-edge-cloud collaborative FML framework..... | 4 | +| 8.2 Requirements for end devices ..... | 4 | +| 8.3 Requirements for edge servers ..... | 4 | +| 8.4 Requirements for the cloud server..... | 5 | +| Appendix I – Use cases of device-edge-cloud collaborative FML ..... | 6 | +| I.1 Recommendation systems ..... | 6 | +| I.2 Autonomous driving systems ..... | 6 | +| Bibliography..... | 7 | + + + +# Recommendation ITU-T F.748.62 + +## Technical framework and requirements for device-edge-cloud collaborative federated machine learning + +# 1 Scope + +This Recommendation provides the framework and requirements for device-edge-cloud collaborative federated machine learning (FML), and specifies its concept, procedure, requirements and use cases. + +The scope includes: + +- Reference framework and common procedure of device-edge-cloud collaborative FML. +- Requirements for device-edge-cloud collaborative FML framework. + +Use cases of device-edge-cloud collaborative FML are provided in Appendix I. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[\[ITU-T X.1600\]](#) Recommendation ITU-T X.1600 (2024), *Security architecture of edge cloud*. + +[\[ITU-T X.1648\]](#) Recommendation ITU-T X.1648 (2025), *Guideline on edge computing data security*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +None. + +## 3.2 Terms defined in this Recommendation + +None. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +FML Federated machine learning + +ML Machine learning + +# 5 Conventions + +In this Recommendation: + +The keywords "**is required**" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. + +The keywords "**is recommended**" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement needs not be present to claim conformance. + +# 6 Device-edge-cloud collaborative FML framework + +Federated machine learning (FML) is an emerging distributed learning framework that allows to collaboratively train a shared machine learning (ML) system among multiple participants while keeping data locally, bringing the advantages of breaking data islands and protecting data privacy [b-ITU-T F.748.35]. To improve communication efficiency and obtain satisfactory training performance, the device-edge-cloud collaborative FML framework is proposed. In this framework, each edge server can own several end devices depending on its communication and computation capabilities, and the cloud server can access multiple edge servers. As the number of edge devices increases, the accessed number of end devices in this system can grow. This framework is suitable for large-scale end devices and has the advantages of overcoming single points of failure, avoiding network congestion and expanding the scale of access devices. More importantly, this framework can guarantee model training efficiency and convergence accuracy due to the participation of large-scale end devices. It also improves resource utilization by balancing training task assignments. + +Figure 1 depicts a reference framework of device-edge-cloud collaborative FML. The device-edge-cloud collaborative FML framework usually consists of one cloud server, multiple edge servers and many end devices. In this framework, each participating end device should be associated with one edge server, and each edge server should be associated with the cloud server. Model parameters are exchanged between end devices and their associated edge servers, and also between edge servers and the cloud server. At each training round, edge servers aggregate updated local models uploaded by end devices and then generate the updated intermediate models. The cloud server then aggregates updated intermediate models uploaded by edge servers and generates the updated global model. The updated global model is transmitted from the cloud server to edge servers, and the updated intermediate models are transmitted from edge servers to the end devices for subsequent training. + +![Diagram of the device-edge-cloud collaborative FML framework showing three layers: Cloud server, Edge servers, and End devices, each with four functional blocks.](d0abac95583b52a3b35f74a215567334_img.jpg) + +The diagram illustrates the 'End-edge-cloud collaborative FML' framework. It is composed of three stacked layers, each enclosed in a dashed rectangular box. The top layer is labeled 'Cloud server' and contains four boxes: 'Data storage', 'Model interaction', 'Resource management', and 'Security requirements'. The middle layer is labeled 'Edge servers' and contains the same four boxes. The bottom layer is labeled 'End devices' and also contains the same four boxes. Double-headed vertical arrows connect the 'Cloud server' layer to the 'Edge servers' layer, and the 'Edge servers' layer to the 'End devices' layer, indicating bidirectional communication. A small label 'F.748.62(25)' is located at the bottom right of the diagram. + +Diagram of the device-edge-cloud collaborative FML framework showing three layers: Cloud server, Edge servers, and End devices, each with four functional blocks. + +**Figure 1 – Framework of device-edge-cloud collaborative FML framework** + +The cloud server side offers four main categories of functions, namely, data storage, model interaction, resource management and security requirements. Data storage is used for storing global model parameters. Model interaction is used for managing the association of edge servers during the FML procedure. Resource management is used for allocating communication and computation resources for the associated edge servers and for exchanging model parameters with edge servers, including receiving the uploaded intermediate models by edge servers, aggregating intermediate models for generating the updated global model and distributing the aggregated global model to edge + +servers. The security requirements are for ensuring secure aggregation and safe operation at the cloud server. + +The edge-server side offers the same four main categories of functions as the cloud server. Data storage is used for storing the uploaded local models and the aggregated intermediate models. Model interaction is used for managing the association with end devices and the cloud server during the FML procedure. Resource management is used for allocating communication and computation resources for the associated end devices, exchanging model parameters with end devices and the cloud server. The security requirements are for ensuring secure aggregation and safe operation at edge servers. + +The end-devices side also includes the four main categories of functions as the cloud server and edge servers. Data storage is used for storing the local models and privacy data. Model interaction is used for exchanging model parameters with the associated edge server for each end device, including uploading local models to edge servers and receiving the downloaded global model from edge servers. Resource management is used for managing communication and computation resources for local model training and parameter interaction. The security requirements are for ensuring secure training and safe operation at end devices. + +# 7 Procedure of device-edge-cloud collaborative FML + +The basic procedure under device-edge-cloud collaborative FML framework is shown in Figure 2, and described as follows: + +![Diagram illustrating the procedure of device-edge-cloud collaborative FML. The diagram shows three layers: End devices (bottom), Edge servers (middle), and Cloud server (top). The process involves: 1) local model training at end devices; 2) upload local models from end devices to edge servers; 3) aggregate local models at edge servers; 4) upload intermediate models from edge servers to cloud server; 5) aggregate intermediate models at cloud server; 6) broadcast global model from cloud server to edge servers; 7) broadcast global model from edge servers to end devices.](367926125450c2bc3f4bdca9d59a62ba_img.jpg) + +The diagram illustrates the collaborative Federated Machine Learning (FML) procedure across three layers: End devices, Edge servers, and Cloud server. The process is as follows: + +- ① local model training: End devices perform local model training. +- ② upload local models: End devices upload local models to edge servers. +- ③ aggregate local models: Edge servers aggregate local models. +- ④ upload intermediate models: Edge servers upload intermediate models to the cloud server. +- ⑤ aggregate intermediate models: The cloud server aggregates intermediate models. +- ⑥ broadcast global model: The cloud server broadcasts the global model to edge servers. +- ⑦ broadcast global model: Edge servers broadcast the global model to end devices. + +F.748.62(25) + +Diagram illustrating the procedure of device-edge-cloud collaborative FML. The diagram shows three layers: End devices (bottom), Edge servers (middle), and Cloud server (top). The process involves: 1) local model training at end devices; 2) upload local models from end devices to edge servers; 3) aggregate local models at edge servers; 4) upload intermediate models from edge servers to cloud server; 5) aggregate intermediate models at cloud server; 6) broadcast global model from cloud server to edge servers; 7) broadcast global model from edge servers to end devices. + +**Figure 2 – Procedure of device-edge-cloud collaborative FML** + +- (1) The end devices simultaneously perform local model training on a pre-given ML model with their owned dataset and obtain the updated local models. +- (2) Each end device uploads its updated local models to the edge server it belongs to. +- (3) The edge servers aggregate local models and generate the updated intermediate models after receiving updated local models from the end devices. +- (4) Each edge server uploads its owned intermediate model to the cloud server. + +- (5) The cloud server aggregates intermediate models and generates the updated global model after receiving uploaded intermediate models from edge servers. +- (6) The cloud server broadcasts the updated global model to edge servers. +- (7) The edge servers broadcast the updated global model to end devices. + +# **8 Requirements of device-edge-cloud collaborative FML framework** + +## **8.1 General requirements of device-edge-cloud collaborative FML framework** + +- It is required to contain one cloud server, multiple edge servers and many end devices. +- It is required to contain edge aggregation stage and cloud aggregation stage. +- It is required to contain end-edge and edge-cloud interaction operation for exchanging model parameters. +- It is recommended to have strong scalability for large-scale devices scenarios. +- It is required to standardize the interaction protocol to guarantee end-device-edge communication. +- It is required to collaboratively orchestrate computation and communication resources among device-edge-cloud nodes. +- It is required to ensure model security, transmission security, device-edge-cloud nodes security throughout the FML training process. +- It is recommended to support the security capabilities specified in [ITU-T X.1600] and [ITU-T X.1648]. + +## **8.2 Requirements for end devices** + +### **8.2.1 Data storage** + +- It is required to store private data on distributed end devices. +- It is required to store local model parameters on end devices at each training round. + +### **8.2.2 Model interaction** + +- It is required to determine one edge server for each end device to exchange model parameters. +- It is required to standardize the interaction protocol to guarantee device-edge communication. + +#### **8.2.3 Resource management** + +- It is required to allocate enough resources for end nodes to support local model training. +- It is recommended to select the set of end devices with sufficient resources for participating in the current round of model training. + +#### **8.2.4 Security requirements** + +- It is required to ensure the security of local model training at participating end nodes and to prevent tampering with local data and the injection of incorrect model updates. +- It is required to ensure the security of uploading local model parameters without compromising data privacy. + +## **8.3 Requirements for edge servers** + +#### **8.3.1 Data storage** + +- It is required to store uploading local model parameters from end devices on edge servers. +- It is required to store aggregated intermediate model parameters on edge servers. + +### **8.3.2 Model interaction** + +- It is required to exchange intermediate model parameters with the cloud server. +- It is required to standardize interaction protocol to guarantee edge-cloud communication. + +#### **8.3.3 Resource management** + +- It is required to allocate enough resources for edge servers for intermediate aggregation and model training. +- It is required to allocate communication and computation resources for the associated end devices. +- It is recommended to select the set of edge nodes with sufficient resources for participating in the current round of model training and intermediate aggregation. + +#### **8.3.4 Security requirements** + +- It is required to evaluate the security differences among different end nodes and select reliable end nodes to participate in federated learning processes. +- It is required to have a secure aggregation strategy to screen out untrustworthy end nodes and avoid contaminating the aggregated global model during model aggregation. +- It is recommended to ensure the security and correctness of the received global model from the cloud server and download the secure global model to the end nodes. + +## **8.4 Requirements for the cloud server** + +### **8.4.1 Data storage** + +- It is required to store the uploaded intermediate model parameters from edge devices on the cloud servers. +- It is required to store the aggregated global model parameters on the cloud servers. + +### **8.4.2 Model interaction** + +- It is required to broadcast the global model parameters with edge servers. +- It is required to standardize the interaction protocol to guarantee edge-cloud communication. + +#### **8.4.3 Resource management** + +- It is required to allocate enough computation resources for the cloud server for the global aggregation and model interaction. +- It is required to allocate communication and computation resources for the associated edge servers. + +#### **8.4.4 Security requirements** + +- It is required to evaluate the security differences among different edge nodes and select reliable edge nodes to participate in cloud-side aggregation. +- It is required to have the secure aggregation strategy to screen out untrustworthy edge nodes and avoid contaminating the aggregated global model during model aggregation. +- It is recommended to ensure the security and correctness of the global model and download the secure global model to the edge nodes. + +# Appendix I + +## Use cases of device-edge-cloud collaborative FML + +(This appendix does not form an integral part of this Recommendation.) + +### I.1 Recommendation systems + +Recommendation system uses users' historical data and associated information to predict user preferences and recommend products they may be interested in, such as news, videos and shopping. By leveraging device-edge-cloud collaborative FML, recommendation systems enable to provide personalized services while safeguarding user privacy. Specifically, the system can collaboratively train recommendation local models across multiple devices without needing to transmit raw user data, thereby reducing the risk of privacy breaches. Then, the edge servers aggregate the local models generated by users within their jurisdiction. The global model is aggregated at the cloud server for the overall update. This device-edge-cloud collaborative FML manner ensures timely and relevant recommendations, which is crucial as user preferences and behaviours change frequently. + +## I.2 Autonomous driving systems + +Autonomous driving systems require extensive data for training and validation to enhance safety and reliability. Data often originates from different vehicles and sensors, making centralized training processing challenging. Device-edge-cloud collaborative FML enables to collaboratively train models across multiple vehicles and sensors for autonomous driving systems, and then efficiently process and make real-time decisions distributed, significantly improving driving safety and operating efficiency. Specifically, the end devices are the producer of data and use their private data to train local models. Then, the edge servers, such as computing nodes deployed in roadside units (Rsus), cellular base stations, or regional data centres, aggregate model updates from multiple vehicles to generate the regional edge models. Multiple edge servers upload their respective regional edge models to the cloud, and the cloud performs higher-level aggregation to generate a more powerful and universal global model. This paradigm can accelerate the application and development of autonomous driving technology, driving the advancement of intelligent transportation. + +# Bibliography + +[b-ITU-T F.748.35] Recommendation ITU-T F.748.35 (2024), *Requirement and framework of trustworthy federated machine learning based service*. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.748.63-202512-I_PDF-E/35a7554182eb055209552843f341a1ae_img.jpg b/marked/F/T-REC-F.748.63-202512-I_PDF-E/35a7554182eb055209552843f341a1ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..083faa7b8f8f3ea298e7d509c6dfa99ceb2c567b --- /dev/null +++ b/marked/F/T-REC-F.748.63-202512-I_PDF-E/35a7554182eb055209552843f341a1ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:af59fe3cf8ade9d971fa4b480f3453d93ffce65a4c75500d6843332d662e1634 +size 114068 diff --git a/marked/F/T-REC-F.748.63-202512-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg b/marked/F/T-REC-F.748.63-202512-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d4d8969f805414689ab79cfd08c333d454d482b3 --- /dev/null +++ b/marked/F/T-REC-F.748.63-202512-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:636c3839edff955a5b6208530b05fa1c983ab153d90f00216517a7a99478b988 +size 7074 diff --git a/marked/F/T-REC-F.748.63-202512-I_PDF-E/raw.md b/marked/F/T-REC-F.748.63-202512-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..fceceb8c02c456c5efbc8d9cc3b2fd3331278a7b --- /dev/null +++ b/marked/F/T-REC-F.748.63-202512-I_PDF-E/raw.md @@ -0,0 +1,393 @@ + + +# Recommendation **ITU-T F.748.63 (12/2025)** + +SERIES F: Non-telephone telecommunication services + +Multimedia services + +--- + +## **Framework and general technical requirements of foundation model enhanced digital human systems** + +![ITU logo](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with white lines representing latitude and longitude, and the letters 'ITU' in a bold, blue, sans-serif font overlaid on the globe. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.748.63 + +# Framework and general technical requirements of foundation model enhanced digital human systems + +## Summary + +Recommendation ITU-T F.748.63 specifies a framework and general technical requirements for foundation model enhanced digital human systems. It introduces a framework that integrates foundation model capabilities into digital human systems, covering modelling, rendering, driving and interaction processes. The Recommendation describes typical application scenarios of foundation models across different phases of digital human systems and specifies technical requirements for the modelling, driving and interaction phases to ensure enhanced intelligence, safety and reliability. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.748.63 | 2025-12-14 | 21 | 11.1002/1000/16588 | + +## Keywords + +Digital human driving, digital human interaction, digital human modelling, digital human rendering, digital human system, foundation model, framework. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2026 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|----------------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 2 | +| 6 Framework of foundation model enhanced digital human systems ..... | 2 | +| 7 General technical requirements of model layer ..... | 4 | +| 7.1 Large language model ..... | 4 | +| 7.2 Vision model ..... | 4 | +| 7.3 Audio model ..... | 5 | +| 7.4 Image/Video synthesis model..... | 5 | +| 8 General technical requirements of application layer ..... | 6 | +| 8.1 Modelling phase ..... | 6 | +| 8.2 Driving phase..... | 7 | +| 8.3 Interaction phase..... | 7 | +| Bibliography..... | 10 | + + + +# Recommendation ITU-T F.748.63 + +## Framework and general technical requirements of foundation model enhanced digital human systems + +## 1 Scope + +This Recommendation provides a framework and general technical requirements for foundation model enhanced digital human systems. It addresses the following subjects: + +- a) General technical requirements of applying a foundation model to all aspects of digital human systems; +- b) Framework of foundation model enhanced digital human systems; +- c) Applications of foundation model in digital human systems. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following term defined elsewhere: + +**3.1.1 digital human** [b-ITU-T F.748.15]: A computer application that integrates the technologies of computer graphics, computer vision, intelligent speech, natural language processing. It can be used for digital content generation and human-computer interaction to help improve content production efficiency and user experience. + +### 3.2 Terms defined in this Recommendation + +None. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|----------------------------| +| 2D | 2-Dimensional | +| 3D | 3-Dimensional | +| HDRi | High Dynamic Range imaging | +| NeRF | Neural Radiance Field | +| PBR | Physically Based Rendering | +| Q&A | Questions and Answers | + +## 5 Conventions + +- The keywords "is required to" indicate a requirement that must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. +- The keywords "is recommended to" indicate a requirement that is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +## 6 Framework of foundation model enhanced digital human systems + +Foundation models can profoundly enhance digital human systems by empowering them with advanced conversational ability, complex reasoning, emotional intelligence and scalable content creation. The framework of foundation model enhanced digital human systems is shown in Figure 1. + +![Figure 1: Framework of foundation model enhanced digital human systems. The diagram shows two main layers: the Application layer and the Model layer. The Application layer is divided into three phases: modelling, driving, and interaction. The Model layer contains the Foundation model components.](35a7554182eb055209552843f341a1ae_img.jpg) + +The diagram illustrates the framework of foundation model enhanced digital human systems, organized into two primary layers: + +- Application layer**: This layer is subdivided into three phases: + - Application in modelling phase**: Includes 2D digital human appearance generation, 3D structure generation, Texture mapping generation, Scene combination, and Scene image generation. + - Application in driving phase**: Includes Lip motion generation, Gestures and body movements generation, Instruction and interactive movements generation, and Emotion and emotional action generation. + - Application in interaction phase**: Includes Text dialogue, Speech interaction, Visual interaction, and Multimodal interaction. +- Model layer**: This layer contains the **Foundation model**, which consists of Large language model, Vision model, Audio model, and Image/Video synthesis model. + +F.748.63(25) + +Figure 1: Framework of foundation model enhanced digital human systems. The diagram shows two main layers: the Application layer and the Model layer. The Application layer is divided into three phases: modelling, driving, and interaction. The Model layer contains the Foundation model components. + +**Figure 1 – Framework of foundation model enhanced digital human systems** + +The foundation model enhanced digital human system comprises two layers: the application layer and the model layer. The model layer is the capability foundation of the system, providing generation and interaction capabilities for the application layer. The application layer is the entire process of building digital humans empowered by the model layer. + +The model layer is mainly responsible for analysing the tasks entered by the digital human, judging whether it is necessary to call the external application domain knowledge base or tool library to obtain professional knowledge or perform professional operations and getting the content returned to the digital human system after comprehensive processing. + +The application layer is mainly composed of the following components: + +### a) Application in modelling phase + +In the digital human modelling phase, the foundation model can be applied to 3-dimensional (3D) structure generation, texture mapping generation, scene combination, scene image generation and so on. + +- 2-dimensional (2D) digital human appearance generation: It generates computationally driven 2D digital human. +- 3D structure generation: It generates 3D meshes end-to-end from input images or text prompts. The generated content includes digital humans, assets attached to digital humans and items within digital human scenes. +- Texture mapping generation: It utilizes foundation models to produce texture maps, including diffuse, normal and material information. +- Scene combination: By leveraging a 3D material library and foundation models to understand user requirements and compose related 3D scenes. +- Scene image generation: It utilizes foundation models to generate 2D unfolded images of 3D scenes. + +### b) Application in driving phase + +In the digital human driving phase, digital human is given lifelike animations according to input signals (such as voice, text, motion capture) such as lip motion, movements, gestures and expressions. Foundation model can be applied to lip motion generation, gestures and body movements generation, instructions and interactive movements motion generation, emotion and action generation, etc. + +- Lip motion generation: It generates synchronous animation of 2D or 3D digital human lip movements according to input speech or text. +- Gestures and body movement generation: It generates natural and smooth non-emotional gestures (such as waving, nodding) and body movements (such as walking, sitting) based on input present content. +- Instruction-based and interactive movement generation: It generates 2D or 3D digital human actions based on input digital human actions or interactive instructions, including actions in response to user instructions (such as walking somewhere) or actions interacting with the virtual environment (such as grabbing virtual objects). +- Emotion and emotional action generation: According to the input digital human broadcast content and its corresponding emotional labels, the corresponding 2D or 3D digital human facial expressions and emotion-driven actions are generated, such as smiling, frowning and increasing the amplitude of gestures when excited. + +### c) Application in interaction phase + +In the digital human interaction phase, foundation model can be applied to text dialogue, speech interaction, visual interaction, multi-modal interaction, etc. + +- Text dialogue: It implements conversational abilities through large text models. +- Speech interaction: Achieves speech recognition and speech synthesis capabilities through foundation models. +- Visual interaction: It utilizes large visual models to recognize user posture or gestures, understand user intentions and control digital human responses. +- Multi-modal interaction: In the context of multimodal foundation model enhanced digital human interaction, digital humans engage in complex interactions with users through multiple sensory modalities such as visual, text and speech. This interaction is not limited to a single mode but integrates various input and output methods to provide a richer and more natural interactive experience. + +## 7 General technical requirements of model layer + +### 7.1 Large language model + +Large language model is the core for achieving the cognitive, understanding and expression capabilities of digital humans, which provides powerful natural language processing and generation services for digital human systems. + +- It is required to have multi-scenario dialogue capabilities: It is required to be able to provide specific domain question-and-answer services based on the knowledge base, as well as open-domain question-and-answer services. It is required to be capable of supporting multi-round dialogues in complex scenarios and effectively managing the context. It is required to be able to provide control services for anthropomorphic dimensions such as personality, character, emotion and viewpoint, and maintain high consistency throughout multiple rounds of dialogue. +- It is required to have deep natural language understanding capabilities: It is required to be able to provide precise intent recognition, entity extraction and sentiment recognition services. It should be able to understand and respond to complex language expressions by integrating context semantics. +- It is required to have structured content generation capabilities: It is required to be able to generate structured text containing emotion labels such as happiness, sadness and anger, as well as action labels such as nodding and waving, based on the dialogue content, to drive the expressions and actions of the digital human. It is required to be able to generate structured card information such as key data and option lists while the digital human is broadcast. +- It is required to have personalized and continuous learning capabilities: It is required to be able to provide personalized dialogue services based on user profiles and preferences. +- It is recommended to have the ability of active learning and continuous learning, continuously optimizing the quality of the dialogue during interaction. It is recommended to have the ability to obtain external information and support real-time networked queries for the latest data. +- It is recommended to have multilingual processing capabilities. + +### 7.2 Vision model + +The vision model serves as the foundation for enabling the environmental perception and visual interaction capabilities of digital humans, which provides powerful visual information understanding services for the digital human system. + +- It is required to have the function of recognizing interactive objects: capable of providing services for the multi-dimensional behaviours of interactive objects, such as full-body postures, gestures and facial expressions. It is required to be able to provide services for recognizing the objects held by interactive objects. It is recommended to have the function of user identity recognition. +- It is required to have the function of perceiving the interactive environment: capable of providing services for the recognition and understanding of key objects and environmental layouts in the interactive scene. It is recommended to have the function of effectively identifying the target user in a multi-person scene and conducting gaze tracking. +- It is required to have the function of understanding visual intentions: capable of providing real-time feedback on the changes in user body movements and gestures. It can determine the user's intention based on the recognized visual information (such as user gestures) and drive the digital human to make corresponding behaviours and reactions. + +### 7.3 Audio model + +The audio model is the key to achieving the voice interaction capability of digital humans, which provides high-quality services for speech recognition, synthesis and understanding for the digital human system. + +- It is required to have high-precision speech recognition (ASR) capabilities: capable of providing accurate speech recognition services in various environmental noises. It is required to be able to convert user speech into text information in real time and support automatic correction based on context. +- It is required to have natural and fluent speech synthesis (TTS) capabilities: capable of providing reply-generation services that are close to human natural speech. It is required to support small sample sound cloning and quickly replicate the timbre of specific individuals. It is recommended to offer diverse timbre options for different genders, ages and roles. +- It is required to have speech feature analysis and understanding capabilities: it is required to have the ability to analyse the speech features of the speaker to determine their emotional state. It is recommended to have voiceprint recognition capabilities for user identity verification and personalized interaction. +- It is recommended to have multilingual speech processing capabilities: capable of providing speech recognition, cloning, translation, and synthesis services for multiple languages. It is recommended to support cross-language speech cloning and synthesis while maintaining the timbre, rhythm and emotion. + +### 7.4 Image/Video synthesis model + +The image/video synthesis model is the core for constructing the image, scene and dynamic performance of digital humans, which provides services for the digital human system to generate corresponding visual content from various inputs such as text, images and audio. + +- It is required to have the functions of generating and editing human images: It is required to be able to provide services for generating 2D digital human images based on text prompts (such as background, clothing, hairstyle, gender). It is required to also be able to provide editing services for 2D images, including but not limited to background replacement, image expansion, accessory addition and deletion, and clothing change. It is recommended to have the function of style transfer for 2D images based on style templates. +- It is required to have the function of generating 3D digital humans and scene assets: It is required to be able to provide end-to-end services for generating 3D mesh models (digital humans, clothing, props). It is required to be able to generate high-precision 3D model details, including the face, mouth, teeth, torso. It is required to be able to provide the generation service of physically based rendering (PBR) material texture maps. It is required to be able to provide the generation and logical layout services of scene elements based on text descriptions. It is recommended to have the function of synthesizing 3D scenes using the neural radiance field (NeRF) technology. +- It is required to have the function of generating limb and expression animations: It is required to be able to generate natural and smooth 2D or 3D digital human limb movements (such as gestures, head movements, torso movements) and expression animations based on text, voice or video templates. It is required to also be able to generate corresponding behavioural actions based on clear user instructions (such as standing, walking, pointing). +- It is recommended to support interaction with scene objects. It is recommended to have the function of automatically generating matching dance movements based on the input music beat and style. + +- It is required to have the ability to integrate and generate cross-modal information: It is required to be able to effectively integrate multiple input modalities such as text, voice and vision to accurately interpret and execute multimodal instructions. It is required to be able to simultaneously generate matching expressions, actions and gestures based on the fused information, achieving rich multimodal expression. + +## **8 General technical requirements of application layer** + +### **8.1 Modelling phase** + +#### **8.1.1 2D digital human appearance generation** + +- It is required to support the generation of 2D images by text prompt words, including background description, clothing description, hairstyle description, accessory description and gender description. The goal can be achieved through multiple prompts. +- It is required to support the editing of the generated 2D image material based on the foundation model, including changing the background and expanding the image, and it is required to have advanced editing functions, such as adding and deleting accessories and changing clothes. +- It is recommended to support the 2D digital human style transfer function according to the selected style template to match the digital human image style. +- It is recommended to support personalized generation capabilities, according to user-uploaded photographs and text prompts to produce a 2D virtual avatar with identity (ID) consistency. + +#### **8.1.2 3D structure generation** + +- It is required to support high-precision 3D model details generation for geometric structures, including facial details, torso, clothing. Head models include face, mouth, upper and lower teeth, tongue, left and right eyeballs. +- It is recommended to support the use of NeRF technology to synthesize 3D scene representation. + +#### **8.1.3 Texture mapping generation** + +- It is required to support PBR material generation, including diffuse reflection, normal, roughness, metallicity. +- It is recommended to have the function of error detection and automatic correction during texture generation. + +#### **8.1.4 Scene combination** + +- It is required to support intelligent scene combination technology, including automatic retrieval of 3D material library, scene element generation, semantic understanding of user requirements and logical layout of scene elements. +- It is required to support rapid response to user commands and scene construction that highly conforms to user expectations. +- It is recommended to provide multiple rounds of instruction interaction to improve 3D scene optimization layout. + +#### **8.1.5 Scene image generation** + +- It is required to support advanced scene image generation techniques, including dynamic rendering of high dynamic range imaging (HDRi) environment maps and generation of 360-degree panoramic skyboxes. + +### **8.2 Driving phase** + +#### **8.2.1 Lip motion generation** + +- It is required to support clear and accurate lip synchronization in multiple languages and local languages. +- It is recommended to automatically adjust mouth shape parameters according to input speech changes, including volume, intonation, speech speed, mood. + +#### **8.2.2 Gestures and body movement generation** + +- It is required to support the generation of natural and smooth gestures and body movements according to the input content, including waving, nodding, standing, sitting and other non-emotional basic movements. +- It is required to support the generation of 2D or 3D digital human gestures and body movements based on preset video or animation templates. +- It is recommended to have the function of generating gestures and body movements in text, play preset videos or animations of gestures and body movements based on the intention recognition of text content, and ensure that the connection and switch of actions are coherent and natural. It is recommended to generate matching dance movements according to the input music, including style, rhythm, drum beat and other automatic matching. + +#### **8.2.3 Instruction and interactive movement generation** + +- It is required to support the generation of diverse 2D or 3D digital human actions according to input instructions, including standing, sitting, walking, pointing. +- It is recommended to have the ability to interact with the scene or objects in the scene according to instructions, such as grabbing virtual objects. +- It is recommended to have the ability to automatically analyse complex instructions and perform a series of synthetic actions in response to the instructions, with the overall action being coherent and natural. + +#### **8.2.4 Emotion and emotional action generation** + +- It is required to support the generation of 2D or 3D digital human facial expressions and emotion-driven actions based on the input text or voice content and its corresponding emotional labels, including emotional expressions such as happiness, sadness, anger, calm, and behavioural actions such as nodding, waving and clapping that match emotional expressions. +- It is recommended to automatically synchronize the expression and action label database and dynamically update and expand the number of supported labels. + +### **8.3 Interaction phase** + +#### **8.3.1 Text dialogue** + +- It is required to support multi-scenario conversation technologies, including knowledge-based domain-specific questions and answers (Q&A), open domain Q&A, complex scene multi-round conversation, persona consistency and stability, sensitive content detection and filtering and fast response. +- It is required to support natural language understanding, including intention recognition, context management, emotion recognition and response, knowledge question answering. +- It is recommended to have the ability to personalize conversations, including the adjustment of conversation content based on user preferences and active learning mechanisms to optimize the quality of conversations. + +- It is recommended to have the ability to speak multiple languages and active learning, enabling proactive and continuous learning in open-scenario interactions. It is recommended to have highly anthropomorphic ability, including personality, personality, emotion, perspective and other dimensions, to maintain a high degree of consistency in multiple rounds of dialogue. It is recommended to external information acquisition capability, real-time access to the latest data. + +#### **8.3.2 Speech interaction** + +- It is required to support multilingual speech recognition, cloning, translation, synthesis and other functions. +- It is required to support high-precision speech recognition and natural and smooth speech synthesis, including accurate recognition under various environmental noise, as well as response generation close to human natural speech. +- It is required to support the conversion of the user's speech into text information that can be processed, support the comprehensive analysis of the voice content before and after, support automatic error correction and improve the accuracy of specific semantic understanding. +- It is required to support small sample sound cloning function. +- It is recommended to support open scene speech recognition. +- It is recommended to support multi-language speech cloning and synthesis. +- It is recommended to have automatic detection and recognition of accents from different regions. +- It is recommended to support digital human cross-language translation, that is, after receiving the voice, the digital human can speak the translated voice in the specified language under the condition of maintaining the timbre, rhythm and emotion. +- It is recommended to analyse speech features, including the level of intonation, speed of speech, volume and rhythm of speech, so as to realize the judgment of the speaker's emotional state, including the accurate judgment of basic emotions such as happiness, sorrow and joy. It is recommended to have voiceprint recognition capabilities, including user authentication and personalized voice interactions, as well as emotional speech synthesis capabilities to enrich the emotional expression of voice interactions. + +#### **8.3.3 Visual interaction** + +- It is recommended to support multi-dimensional limb posture recognition, including full-body posture and expression. +- It is recommended to have a high degree of natural human-computer interaction, including real-time feedback on changes in user body movements and gestures, as well as judging user intentions based on these inputs, and adjusting the behaviour and reaction of digital human. +- It is recommended to have complex scene adaptability, including target user recognition in multi-person scenes and eye tracking capabilities to enhance the naturalness and accuracy of visual interactions. + +#### **8.3.4 Multi-modal interaction** + +- It is required to support cross-modal fusion, support a variety of input methods, including the effective integration of text, speech, vision and other information, to achieve the accurate analysis and execution of multi-modal instructions. +- It is required to support the expression of digital human's expressions, actions and gestures, including common emotions, common guiding actions and gestures. + +- It is required to have the ability of continuous learning, through the continuous collection and analysis of multi-modal interaction data, optimize the interaction model and improve the user experience. +- It is recommended to present information, including key data, option lists and diagrams, in a structured card format alongside digital human broadcasting. +- It is recommended to have dialogue filling capabilities, including varying degrees of reassurance depending on the length of the wait. +- It is recommended to have the ability to interrupt conversations, including responding quickly and accurately gauging user intent. + +## Bibliography + +[b-[ITU-T F.748.15](#)] Recommendation ITU-T F.748.15 (2022), *Framework and metrics for digital human application systems*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.748.64-202512-I_PDF-E/410562339ce067fdc6fa41940c118658_img.jpg b/marked/F/T-REC-F.748.64-202512-I_PDF-E/410562339ce067fdc6fa41940c118658_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c8cbe4257a40ea1fbb04e6a1e5e674a168df0a9c --- /dev/null +++ b/marked/F/T-REC-F.748.64-202512-I_PDF-E/410562339ce067fdc6fa41940c118658_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:97efdd06e88ffda962027f5472f5a6b44a25957c6a4244c3d419cbcb6c1aa88e +size 46928 diff --git a/marked/F/T-REC-F.748.64-202512-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/F/T-REC-F.748.64-202512-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d4d8969f805414689ab79cfd08c333d454d482b3 --- /dev/null +++ b/marked/F/T-REC-F.748.64-202512-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:636c3839edff955a5b6208530b05fa1c983ab153d90f00216517a7a99478b988 +size 7074 diff --git a/marked/F/T-REC-F.748.64-202512-I_PDF-E/c0e88e4bd3a209b66ee7cb67e1cec2be_img.jpg b/marked/F/T-REC-F.748.64-202512-I_PDF-E/c0e88e4bd3a209b66ee7cb67e1cec2be_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..fe55659d94db547d00cf73eb6bf2b258cb85388e --- /dev/null +++ b/marked/F/T-REC-F.748.64-202512-I_PDF-E/c0e88e4bd3a209b66ee7cb67e1cec2be_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:b333a8a018486977c17298f44ad42f1af411d0509b56d7c3495892e7d3ff5291 +size 106644 diff --git a/marked/F/T-REC-F.748.64-202512-I_PDF-E/raw.md b/marked/F/T-REC-F.748.64-202512-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..903bd6f2dafb9602e72ecce51735782c289ab23c --- /dev/null +++ b/marked/F/T-REC-F.748.64-202512-I_PDF-E/raw.md @@ -0,0 +1,609 @@ + + +Recommendation + +**ITU-T F.748.64 (12/2025)** + +SERIES F: Non-telephone telecommunication services + +Multimedia services + +--- + +**Requirements for digital human service +platforms** + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with white grid lines and a stylized 'ITU' text in blue, with a white lightning bolt symbol integrated into the letter 'T'. + +ITU logo + +# ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.748.64 + +# Requirements for digital human service platforms + +## Summary + +Digital human service platforms can provide services for the development, deployment, operation and maintenance of digital humans. + +Recommendation ITU-T F.748.64 offers an overview and specify general requirements and functional requirements for digital human service platforms, to support the development and selection of these platforms. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.748.64 | 2025-12-14 | 21 | 11.1002/1000/16589 | + +## Keywords + +Compatibility, digital human service platform, ease of use, function, reliability, requirement, scalability, time response. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2026 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|----------------------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation ..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 2 | +| 6 Overview of digital human service platforms ..... | 2 | +| 7 Requirements of digital human service platforms ..... | 3 | +| 7.1 General requirements..... | 3 | +| 7.2 Functional requirements ..... | 4 | +| Appendix I – 3D digital human image modelling quality classification ..... | 7 | +| I.1 General description..... | 7 | +| I.2 Digital human art style classification ..... | 7 | +| I.3 Head model quality grading ..... | 7 | +| I.4 Expression quality grading ..... | 9 | +| I.5 Hair system quality grading..... | 9 | +| I.6 Body model quality grading ..... | 10 | +| I.7 Clothing model quality grading..... | 11 | +| Bibliography..... | 13 | + + + +# Recommendation ITU-T F.748.64 + +## Requirements for digital human service platforms + +## 1 Scope + +This Recommendation establishes a comprehensive set of requirements for digital human service platforms, which cover key dimensions including functionality, compatibility, reliability, scalability, time response and ease of use. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +## 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following term defined elsewhere: + +**3.1.1 digital human** [b-ITU-T F.748.15]: A computer application that integrates the technologies of computer graphics, computer vision, intelligent speech and natural language processing. It can be used for digital content generation and human-computer interaction to help improve content production efficiency and user experience. + +## 3.2 Terms defined in this Recommendation + +None. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|-----------------------------------| +| 2D | 2-Dimensional | +| 3D | 3-Dimensional | +| AI | Artificial Intelligence | +| API | Application Programming Interface | +| CPU | Central Processing Unit | +| GPU | Graphics Processing Unit | +| SaaS | Software as a Service | +| SDK | Software Development Kit | +| VTM | Video Teller Machine | + +## 5 Conventions + +This Recommendation uses the following conventions: + +- The keywords "is required to" indicate a requirement that must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. +- The keywords "is recommended to" indicate a requirement that is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +## 6 Overview of digital human service platforms + +Digital human service platforms can provide services for the development, deployment, operation and maintenance of digital humans. The platform generally includes three layers: the foundation layer, platform layer and application layer, as shown in Figure 1. + +![Figure 1 – Overview of digital human service platform. The diagram shows three layers: Application layer (top), Platform layer (middle), and Foundation layer (bottom). The Application layer includes Finance, Live streaming, Internet, Film and television, Marketing, and ... . The Platform layer includes Digital human generation (Image model generation, Audio model generation, ...), Generative AI applications (Copywriting generation, AI image generation, AI video generation, ...), Video synthesis, and Operation service (live streaming support, expert services, etc.). The Foundation layer includes AI computing power platform, Large model open platform, and Data management platform. A central bar labeled 'Visual engine, audio engine, language engine and API interface' connects the Platform and Foundation layers.](c0e88e4bd3a209b66ee7cb67e1cec2be_img.jpg) + +The diagram illustrates the three-layer architecture of a digital human service platform. The **Application layer** (top) is enclosed in a dashed box and contains several industry-specific application boxes: Finance, Live streaming, Internet, Film and television, Marketing, and an ellipsis (...). The **Platform layer** (middle) is a solid box containing four main functional modules: **Digital human generation** (with sub-modules 'Image model generation', 'Audio model generation', and an ellipsis), **Generative AI applications** (with sub-modules 'Copywriting generation', 'AI image generation', 'AI video generation', and an ellipsis), **Video synthesis**, and **Operation service (live streaming support, expert services, etc.)**. Below these modules is a horizontal bar labeled **Visual engine, audio engine, language engine and API interface**. The **Foundation layer** (bottom) is also enclosed in a dashed box and contains three core platform boxes: **AI computing power platform**, **Large model open platform**, and **Data management platform**. A small text label 'F.748.64(25)' is located at the bottom right of the diagram. + +Figure 1 – Overview of digital human service platform. The diagram shows three layers: Application layer (top), Platform layer (middle), and Foundation layer (bottom). The Application layer includes Finance, Live streaming, Internet, Film and television, Marketing, and ... . The Platform layer includes Digital human generation (Image model generation, Audio model generation, ...), Generative AI applications (Copywriting generation, AI image generation, AI video generation, ...), Video synthesis, and Operation service (live streaming support, expert services, etc.). The Foundation layer includes AI computing power platform, Large model open platform, and Data management platform. A central bar labeled 'Visual engine, audio engine, language engine and API interface' connects the Platform and Foundation layers. + +NOTE – The details of the dashed boxes are out of the scope of this Recommendation. + +**Figure 1 – Overview of digital human service platform** + +- Foundation layer:** The foundation layer consists of an artificial intelligence (AI) computing platform, a data management platform and a large model open platform. Together, they provide the necessary intelligent computing resources, data management support and callable large model services for digital human creation and application deployment. The large model open platform not only offers a rich library of large models, enabling users to easily access and efficiently develop digital humans and generative AI applications through application programming interfaces (APIs) but also includes a comprehensive toolchain to support user fine-tuning and deployment of large models. +- Platform layer:** The platform layer encompasses three core functional modules driven by the AI engine: digital human generation, generative AI applications and video synthesis. The AI engine, comprised of vision, audio and language processing engines, as well as APIs, efficiently accesses the computing resources and large model capabilities of the foundation layer, ensuring smooth operation of the three core functional modules of the digital human platform and providing users with smooth and efficient services. Furthermore, the platform layer includes an operation service platform, which aims to bridge the gap between technical implementation and actual application, ensuring smooth deployment and market adoption. +- Application layer:** As the final value delivery layer, the application layer transforms the hardware/software capabilities of the foundation layer and the technical modules of the platform layer into practical business solutions through vertical industry application implementation. Application areas include finance, live streaming, Internet services, film and television, and digital marketing. + +## 7 Requirements of digital human service platforms + +### 7.1 General requirements + +The general requirements of digital human service platforms include compatibility, reliability, resilience, scalability, transparency and usability. + +### 7.1.1 Compatibility + +It is required to support more than one rendering scheme, such as cloud rendering and terminal rendering. + +NOTE 1 – Cloud rendering refers to the image rendering and synthesis of digital humans in the cloud, based on the centralized computing power of the cloud central processing unit (CPU) / graphics processing unit (GPU) server. + +NOTE 2 – Terminal rendering refers to the shape of the digital human performed locally by relying on the computing power of terminal hardware devices, without depending on cloud servers. + +It is required to support multi-channel access capability, such as App, video teller machines (VTMs) and large-screen devices. + +It is required to support the software development kit (SDK) of the cloud rendering mode. + +It is required to support the SDK of the terminal rendering mode. + +It is required to support the integration of existing AI capabilities with third-party vendors/customers, such as speech recognition, speech synthesis, natural language processing and computer vision. + +It is required to support customized integration and docking with existing business systems, such as audio and video platforms and call centre systems. + +It is required to disclose supporting compatible operating systems and hardware. + +It is required to disclose the support situation of human takeover, such as text takeover, voice takeover, video takeover and motion capture equipment takeover. + +### 7.1.2 Reliability + +It is required to support, under the full load state (the maximum number of concurrent paths supported by hardware), stable operation for $7 \times 24$ hours. + +It is required to support the interactive quality inspection function, that is, to transcribe and record the process of human-machine interaction. By analysing failed or unaccomplished interactions, the interaction process to enhance the quality of digital human interactions is improved. + +### 7.1.3 Resilience + +It is required to have a process daemon mechanism. When the digital human engine and service exit abnormally, it can be pulled up to restore the normal running of the engine and service and ensure the overall stability of the service. + +### 7.1.4 Scalability + +It is required to support function expansion, system design with good scalability, adding new functions or modifying existing functions. + +It is required to support performance expansion, horizontal expansion to increase the server to improve system performance, longitudinal expansion to increase the server memory or CPU to improve system performance. + +It is recommended to have good custom scaling capabilities, allowing secondary development and system integration based on open API/SDK. + +### **7.1.5 Transparency** + +It is required to disclose the production cycle of each type of digital human (different image type, driver type and interaction type). + +It is required to disclose the real-time response speed of each type of digital human under the standard resource allocation. For one-way broadcast digital humans, this refers to the real-time rate of video synthesis video with different resolutions and bit rates; for two-way interactive digital human, it refers to end-to-end time consuming or first frame delay time. + +### **7.1.6 Usability** + +It is required to get user approval before creating their own digital humans. + +It is required to be easy for the user to operate and control, and the user manual is required to be provided. + +## **7.2 Functional requirements** + +Functional requirements of digital human service platforms cover functions on image, speech, animation, interaction, content supply and character customization. + +### **7.2.1 Images** + +##### **7.2.1.1 Image type** + +It is required to support one or more types of digital human images, such as 2-dimensional (2D) cartoon images (including animals and anthropomorphic designs), 2D real person images, 3-dimensional (3D) cartoon images (including animals and anthropomorphic designs), 3D semi-realistic images and 3D realistic images. + +##### **7.2.1.2 Image fineness** + +It is required to support precision for one or more digital human images. For 2D digital figures, disclose supported resolution; for 3D digital figures, disclose the number of heads, bodies, hair and clothing. + +##### **7.2.1.3 Image generation mode** + +It is required to support one or more digital human image generation methods for users to customize the digital human image. For different image types, the requirements are as follows: + +- a) For 2D cartoons, 3D realistic images, 3D semi-realistic images and 3D cartoon images (including animals and anthropomorphic designs), it is required to support the following image generation methods: + - i) Provide modular digital human customization and systematically define the parameters of each part of the digital human body, for users to choose and match. + - ii) Provide deep digital human customization and users can fully define the parameters of each part of the digital human body. +- b) For 2D real-person images, it is required to support the following image generation methods: + - i) Generate the digital human image according to the input photo. + - ii) Generate the digital human image according to the input video: + - Input a large amount of video data to generate the high-definition digital human image. + - Input trace video data to generate low-cost, instantly replaceable digital human images. + +##### **7.2.1.4 Costume changes** + +It is required to support digital human image dress changes, for users to customize different digital human dress, such as hair styles, clothing and accessories. + +##### **7.2.1.5 Displacement support** + +It is required to support the displacement situation of digital humans, including the display of different positions in the video picture and the ability of digital humans to move in the scene, such as full-body movement and full-scene transformation. + +NOTE 1 – Full-body movement means that the relative position of the digital human and virtual lens, background and ground can change, which can bring visual effects such as changes in perspective, distance and background environment to the audience. + +NOTE 2 – Full-scene transformation refers to the interaction of people, fields and props. In addition to the relative position of the digital human changing, as the camera user can feel the change of all the elements of the relative position of the whole space, the digital human can naturally interact with the props and the environment (displacement, snatch and form change). + +### **7.2.2 Speech** + +It is required to support the following functions: + +- a) Support speech synthesis ability. +- b) Support voice editing capabilities, including editing speech speed, timbre, volume, emotion and pronunciation. +- c) Support voice conversion ability, that is, let the digital human convert the audio into digital voice in real time, according to the parameters set by voice editing. +- d) Support voice customization ability, such as supporting the routine customization of studio recordings or voice customization of small sample data. + +### **7.2.3 Animation** + +It is required to support the following functions: + +- a) Support one or more drive modes, such as text drive, voice drive, video drive and motion capture device drive. +- b) Support animation of mouth shape, facial expression, body (half body or full body), fingers and background content material. + +### **7.2.4 Interaction** + +It is required to support the following functions: + +- a) Support one or more interaction modes, such as single-round, multi-round dialogue, full-duplex and other voice interaction, sign language, body movement, line of sight and other visual interaction, click and other touch screen interaction and multi-modal interaction. +- b) Support for autonomous interaction or passive interaction. Autonomous interaction refers to the active initiation of interaction behaviour at the appropriate time according to the time, place and user status, which can be voice interaction or visual information display. Autonomous interaction refers to proactively initiating interactive behaviours at the right moment, based on time, location and user status, which can include voice interaction, visual information display, etc. Passive interaction capabilities include driving interaction through manually inputting text, voice or video, or driving digital human interaction via motion capture devices. +- c) Support emotional performance, such as joy, anger, sorrow and other emotions. +- d) Support the rich media display capabilities in the interactive process, such as charts, videos and virtual items. + +#### **7.2.5 Content construction** + +It is required to support one or more of the following content construction methods: + +- a) Manual construction: This refers to the manually prepared digital human application scenarios through non-instrumental methods, which requires manual editing, import or submission by the implementer. +- b) Software as a service (SaaS) tool construction: This refers to the instrumental software that supports digital human users to create or modify the content of digital human application scenarios, such as live script editing tools and knowledge editing. User can use directly for the digital human after creation or modification. +- c) Intelligent generation: This refers to the automatic generation of application scene content for digital humans through algorithms or big data mining, such as commodity introduction script of e-commerce live broadcast, script of live news broadcast, and question and answer knowledge base. + +#### **7.2.6 Character customization** + +It is required to support style consistency in the output of digital human technology, that is, to maintain the consistency of human design, including digital human identity, character, image, voice and expression. + +## Appendix I + +## 3D digital human image modelling quality classification + +(This appendix does not form an integral part of this Recommendation.) + +### I.1 General description + +The quality classification of 3D digital human image modelling is a reference to investigate and distinguish the precision of 3D digital humans. According to the classification of 3D digital human art style, the modelling quality of 3D digital human images was evaluated from five dimensions, namely, head model, expression drive, hair system, body modelling and clothing model, which were divided into four levels: ordinary quality, intermediate quality, advanced quality and super advanced quality, with the precision increasing successively. Figure I.1 shows the reference structure of 3D digital human image quality classification and grading. + +![Figure I.1 – Digital human service platform evaluation model. The diagram shows a flow from 'Art style classification' (Cartoon, Semi-realistic, Realistic) to 'Modelling quality classification' (Head model, Body model, Expression, Clothing model, Hair system) to a list of quality levels: Super high quality, High quality, Intermediate quality, Ordinary quality. A small code F.748.64(25) is in the bottom right.](410562339ce067fdc6fa41940c118658_img.jpg) + +The diagram illustrates the digital human service platform evaluation model. It consists of three main components connected by arrows. The first component, 'Art style classification', contains three boxes: 'Cartoon', 'Semi-realistic', and 'Realistic'. An arrow points from this component to the second component, 'Modelling quality classification'. This component is a large box containing five smaller boxes: 'Head model', 'Body model', 'Expression', 'Clothing model', and 'Hair system'. An arrow points from the second component to the third component, which is a box containing four quality levels: 'Super high quality', 'High quality', 'Intermediate quality', and 'Ordinary quality'. The text 'F.748.64(25)' is located in the bottom right corner of the diagram. + +Figure I.1 – Digital human service platform evaluation model. The diagram shows a flow from 'Art style classification' (Cartoon, Semi-realistic, Realistic) to 'Modelling quality classification' (Head model, Body model, Expression, Clothing model, Hair system) to a list of quality levels: Super high quality, High quality, Intermediate quality, Ordinary quality. A small code F.748.64(25) is in the bottom right. + +Figure I.1 – Digital human service platform evaluation model + +### I.2 Digital human art style classification + +An art style is used to describe digital human renderings, categorized by how similar they are to real people. Categories: Cartoon, semi-realistic and realistic. Different types of digital humans have different grading requirements and cannot be measured with a unified ruler. For details, see Table I.1. + +Table I.1 – Digital human art style classification criteria + +| Classification | Classification criteria | +|----------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Cartoon | Face shape, eye shape and position, lip shape and position, eyeball shape and other parameters are out of proportion compared to real people. | +| Semi-realistic | Parameters such as face shape, eye shape and position, lip shape and position, eyeball shape and so on are basically proportional to real people, and the face has no skin details. | +| Realistic | Parameters such as face shape, eye shape and position, lip shape and position, and eye shape are strictly proportional to real life, and simulation details such as fluff and skin pores can be observed in a close-up state. | + +### I.3 Head model quality grading + +#### I.3.1 General grading criteria + +Used to describe the quality of a digital human head model. Classification: ordinary quality, intermediate quality, high quality and super high quality. For details, see Table I.2. + +**Table I.2 – Digital human head model quality grading** + +| Grade | Grading criteria | +|----------------------|----------------------------------------------------------------------------| +| Ordinary quality | All sub-indexes of head model quality reach ordinary quality or above. | +| Intermediate quality | All sub-indexes of head model quality reach intermediate quality or above. | +| High quality | All sub-indexes of head model quality reach high quality or above. | +| Super high quality | All sub-indexes of head model quality reach super high quality or above. | + +#### **I.3.2 Number of head model faces** + +The grading criteria for the number of head model faces are shown in Table I.3. + +**Table I.3 – The grading criteria for the number of head model faces** + +| Grade | Grading criteria | +|----------------------|------------------| +| Ordinary quality | [0,10000) | +| Intermediate quality | [10000,20000) | +| High quality | [20000,40000) | +| Super high quality | [40000,+∞) | + +#### **I.3.3 Head model completeness** + +The grading criteria for head model completeness are shown in Table I.4. + +**Table I.4 – The grading criteria for head model completeness** + +| Grade | Grading criteria | +|----------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Ordinary quality | The head model consists of a single grid without separate eyes, mouth and other parts. | +| Intermediate quality | The head model contains a facial grid and a separate mouth or tongue grid, and a separate eyeball structure. | +| High quality | The head model contains a facial mesh, separate mouth mesh, upper and lower tooth mesh, tongue mesh, separate left and right eye mesh, and sculpted with skin textures. | +| Super high quality | The head model includes a facial mesh, an independent mouth mesh, an upper and lower tooth mesh, a tongue mesh, an independent left and right eyeball mesh, an eyelid mesh, a lacrimal gland mesh and other detailed submodels, with detailed skin texture carving. | + +#### **I.3.4 Head texture quality** + +The effective area of facial texture is defined as the image area surrounded by the corresponding texture coordinates of the four points on the head model (the outermost point of the left and right ear contour, the lowest point of the chin, and the centre point of the forehead), and the four sides are parallel to the image boundary. The grading criteria for head texture quality are shown in Table I.5. + +**Table I.5 – The grading criteria for head texture quality** + +| Grade | Grading criteria | +|-------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------| +| Ordinary quality | The effective area of facial texture is less than or equal to 2K. | +| Intermediate quality | The effective area of facial texture is 4K. | +| High quality | The effective area of facial texture is 8K. | +| Super high quality | The effective area of facial texture is greater than 8K, and multi-quadrant UV is used. See Note. | +| NOTE – In this appendix, UV stands for the 2D coordinate system (U axis, V axis) used to map textures onto 3D surfaces. | | + +#### I.3.5 Head texture completeness + +The grading criteria for head texture completeness are shown in Table I.6. + +**Table I.6 – The grading criteria for head texture completeness** + +| Grade | Grading criteria | +|----------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Ordinary quality | Contains only diffuse textures. | +| Intermediate quality | Including diffuse texture, normal texture and permutation texture. | +| High quality | Including diffuse reflection texture, normal texture, permutation texture, highlight texture and subsurface scattering texture. | +| Super high quality | Including diffuse texture, normal texture, displacement texture, highlight texture, roughness texture and subsurface scattering texture (curvature texture). | + +### I.4 Expression quality grading + +To describe the degree of precision with which an asset can present an expression, the number of basic expressions used to form an expression in the dynamic driving process is used as a grading criterion. The grading criteria for expression quality grading are shown in Table I.7. + +**Table I.7 – The grading criteria for expression quality grading** + +| Grade | Grading criteria | +|----------------------|---------------------------------------------------| +| Ordinary quality | None. | +| Intermediate quality | The number of basic expressions is less than 100. | +| High quality | The number of basic expressions is 100-400. | +| Super high quality | More than 400 basic expressions. | + +### I.5 Hair system quality grading + +The grading criteria for hair system quality grading are shown in Table I.8. + +**Table I.8 – The grading criteria for hair system quality grading** + +| Grade | Grading criteria | +|------------------|--------------------------------------------------------------------------------------------| +| Ordinary quality | Use an overall mesh of non-transparent textures to form the hair and colour and render it. | + +**Table I.8 – The grading criteria for hair system quality grading** + +| Grade | Grading criteria | +|----------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Intermediate quality | Create hair and eyelashes with fragmented grids and translucent textures, and colour and render them. | +| High quality | The hair system based on the guideline combines anisotropic materials, to form hair and eyelashes, and colouring and rendering. | +| Super high quality | The guideline-based hair system combines anisotropic materials to form hair and eyelashes, while containing detailed facial fluff and colouring and rendering, including depth textures and tangential textures. | + +### I.6 Body model quality grading + +#### I.6.1 General grading criteria + +The general grading criteria for body model quality grading are shown in Table I.9. + +**Table I.9 – The grading criteria for body model quality grading** + +| Grade | Grading criteria | +|----------------------|----------------------------------------------------------------------------| +| Ordinary quality | All sub-indexes of body model quality reach ordinary quality or above. | +| Intermediate quality | All sub-indexes of body model quality reach intermediate quality or above. | +| High quality | All sub-indexes of body model quality reach high quality or above. | +| Super high quality | All sub-indexes of body model quality reach super high quality or above. | + +#### I.6.2 Number of body model faces + +The grading criteria for the number of body model faces are shown in Table I.10. + +**Table I.10 – The grading criteria for the number of body model faces** + +| Grade | Grading criterion | +|----------------------|-------------------| +| Ordinary quality | [0,10000) | +| Intermediate quality | [10000,20000) | +| High quality | [20000,40000) | +| Super high quality | [40000,+∞) | + +#### I.6.3 Body texture quality + +The grading criteria for body texture quality are shown in Table I.11. + +**Table I.11 – The grading criteria for body texture quality** + +| Grade | Grading criteria | +|----------------------|--------------------------------------------------------------------------------------| +| Ordinary quality | The effective area of body texture is less than or equal to 2K. | +| Intermediate quality | The effective area of body texture is 4K. | +| High quality | The effective area of body texture is 8K. | +| Super high quality | The effective area of body texture is greater than 8K and multi-quadrant UV is used. | + +#### I.6.4 Body binding quality + +The grading criteria for body binding quality are shown in Table I.12. + +**Table I.12 – The grading criteria for body binding quality** + +| Grade | Grading criteria | +|----------------------|------------------------------------------------------------------------------| +| Ordinary quality | The number of bone nodes in the body is less than 80. | +| Intermediate quality | The number of bone nodes in the body is 81-200. | +| High quality | The number of bone nodes in the body is 201-400, using deformation. | +| Super high quality | The number of bone nodes in the body is greater than 400, using deformation. | + +### I.7 Clothing model quality grading + +#### I.7.1 General grading criteria + +The general grading criteria for clothing model quality grading are shown in Table I.13. + +**Table I.13 – The general grading criteria for clothing model quality grading** + +| Grade | Grading criteria | +|----------------------|--------------------------------------------------------------------------------| +| Ordinary quality | All sub-indexes of clothing model quality reach ordinary quality or above. | +| Intermediate quality | All sub-indexes of clothing model quality reach intermediate quality or above. | +| High quality | All sub-indexes of clothing model quality reach high quality or above. | +| Super high quality | All sub-indexes of clothing model quality reach super high quality or above. | + +#### I.7.2 Number of clothing model faces + +The grading criteria for the number of clothing model faces are shown in Table I.14. + +**Table I.14 – The grading criteria for the number of clothing model faces** + +| Grade | Grading criteria | +|----------------------|---------------------| +| Ordinary quality | [0,10000) | +| Intermediate quality | [10000,20000) | +| High quality | [20000,40000) | +| Super high quality | [40000,+ $\infty$ ) | + +#### I.7.3 Clothing texture quality + +The grading criteria for clothing texture quality are shown in Table I.15. + +**Table I.15 – The grading criteria for clothing texture quality** + +| Grade | Grading criteria | +|----------------------|--------------------------------------------------------------------------------------------------------------------------| +| Ordinary quality | The effective area of clothing texture is less than or equal to 2K. | +| Intermediate quality | The effective area of clothing texture is 4K. | +| High quality | The effective area of clothing texture is 8K, at least include diffuse texture, normal texture and displacement texture. | + +**Table I.15 – The grading criteria for clothing texture quality** + +| Grade | Grading criteria | +|--------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Super high quality | The effective area of clothing texture is greater than 8K, and multi-quadrant UV is used. At least include diffuse texture, normal texture, displacement texture, highlight texture and roughness texture. | + +#### **I.7.4 Clothing binding quality** + +The grading criteria for clothing binding quality are shown in Table I.16. + +**Table I.16 – The grading criteria for clothing binding quality** + +| Grade | Grading criteria | +|----------------------|------------------------------------------------------------------------------| +| Ordinary quality | The number of bone nodes in clothing is less than 80. | +| Intermediate quality | The number of bone nodes in clothing is 81-200. | +| High quality | The number of bone nodes in clothing is 201-400, using deformation. | +| Super high quality | The number of bone nodes in clothing is greater than 400, using deformation. | + +## Bibliography + +- [b-ITU-T F.748.15] Recommendation ITU-T F.748.15 (2022), *Framework and metrics for digital human application systems*. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git 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It features a blue globe with white grid lines and a stylized 'ITU' text in blue, with a white lightning bolt symbol integrated into the letter 'I'. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.748.65 + +# Requirements and framework of artificial intelligence (AI)-based cognitive inference system for multimedia applications + +## Summary + +Recommendation ITU-T F.748.65 aims to clarify specific characteristics from the multimedia data and help people solve complex problems. This Recommendation provides an overview of the artificial intelligence (AI)-based cognitive inference system (CIS) and specifies requirements and framework for AI-based cognitive inference system for multimedia applications. + +AI-based cognitive inference system (AI-CIS) for multimedia applications is a system which is used to do inference tasks with multimedia data to complete multimedia applications. The cognitive inference workflow is divided into four steps: problem acquisition, problem deconstruction, answer inference and answer validation. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.748.65 | 2025-12-14 | 21 | 11.1002/1000/16590 | + +## Keywords + +AI-based cognitive inference system, complex problems, multimedia. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2026 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +###### Page + +| | | | +|-----|-------------------------------------------------------------------------------------------------|----| +| 1 | Scope..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| 3.1 | Terms defined elsewhere ..... | 1 | +| 3.2 | Terms defined in this Recommendation..... | 1 | +| 4 | Abbreviations and acronyms ..... | 1 | +| 5 | Conventions ..... | 2 | +| 6 | Overview of cognitive inference system ..... | 2 | +| 7 | Requirements of AI-based cognitive inference system for multimedia applications ... | 2 | +| 7.1 | Requirements of AI-based cognitive inference capabilities..... | 2 | +| 7.2 | Requirements of AI-based cognitive inference methods..... | 3 | +| 7.3 | Requirements of AI-based cognitive inference procedure ..... | 3 | +| 8 | Framework of AI-based cognitive inference system for multimedia applications..... | 3 | +| 8.1 | Intelligent control module ..... | 4 | +| 8.2 | Problem module..... | 4 | +| 8.3 | Answer module..... | 4 | +| 8.4 | Problem status module ..... | 5 | +| 9 | Workflow of cognitive inference..... | 5 | +| 9.1 | Problem acquisition ..... | 6 | +| 9.2 | Problem deconstruction ..... | 6 | +| 9.3 | Answer inference..... | 7 | +| 9.4 | Answer validation..... | 8 | +| | Appendix I – Use cases of AI-based cognitive inference system for multimedia applications ..... | 9 | +| I.1 | Use case of object detection ..... | 9 | +| I.2 | Use case of speech recognition..... | 9 | +| I.3 | Use case of object segmentation..... | 10 | +| | Bibliography..... | 11 | + + + +# Requirements and framework of artificial intelligence (AI)-based cognitive inference system for multimedia applications + +# 1 Scope + +This Recommendation provides an overview of the artificial intelligence (AI)-based cognitive inference system (CIS) and specifies requirements and framework for AI-based cognitive inference system for multimedia applications. + +This Recommendation covers the following: + +- **Requirements:** The capabilities, methods and procedures required for AI-based cognitive inference system in multimedia applications are defined. +- **Framework:** The framework of AI-based cognitive inference system for multimedia applications are defined. +- **Workflow:** The workflow of cognitive inference is specified. + +Use cases of AI-based cognitive inference system are provided in Appendix I. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following term defined elsewhere: + +**3.1.1 artificial intelligence (AI)** [b-ITU-T F.749.13]: An interdisciplinary field, usually regarded as a branch of computer science, dealing with models and systems for the performance of functions generally associated with human intelligence, such as reasoning and learning. + +## 3.2 Terms defined in this Recommendation + +None. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-----|----------------------------| +| 2D | Two Dimensional | +| 3D | Three Dimensional | +| AI | Artificial Intelligence | +| CIS | Cognitive Inference System | + +| | | +|-----|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| DAN | Deep Adaptation Network | +| Q&A | Question and Answer | +| UV | The letters "U" and "V" denote the axes of the two-dimensional (2D) texture because "X", "Y" and "Z" are already used to denote the axes of the three-dimensional (3D) object in model space. "U" represents the horizontal axis and "V" represents the vertical axis. Each UV coordinate has a corresponding point in 3D space called a vertice. | + +# 5 Conventions + +In this Recommendation: + +- The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. +- The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +# 6 Overview of cognitive inference system + +The AI-CIS for multimedia applications is a system which is used to do some inference tasks with multimedia data to help to complete multimedia applications, such as natural language understanding, image recognition, speech recognition and knowledge inference. These will help to provide smarter services to the smarter user-facing services such as intelligent recommendation, intelligent customer service, intelligent question and answer (Q&A) and intelligent decision-making. + +Take the image recognition as an example. First, the user has an image dataset. Second, the user puts a picture in this cognitive inference system as an input. As the output is based on AI technologies, the user can not only get information like what is in the picture, but also know what the scene is, what is happening in this picture, etc. + +With the development of AI technology, the next generation of AI has shifted from perceptual intelligence to cognitive intelligence, and its application scenarios have also expanded from single scenarios to complex problems. Cognitive inference is a crucial approach to using AI to solve complex problems and a key to achieving interpretability of AI. Especially in the implementation of AI applications in industry, which involves industry-specific attributes and business requirements, interpretable solutions to complex problems are particularly important. + +The AI-based cognitive inference system (AI-CIS) is the system that uses artificial intelligence technology to solve inference problems, which provides greater interpretability and intelligence. The AI-CIS can usually be used for multimedia applications to help to infer what the multimedia data stands for, or to mine the meaning of multimedia data in these scenarios, such as intelligent assistants, search by image in the shopping applications, and many other user-facing applications like intelligent customer service, intelligent Q&A, intelligent decision-making, search and recommendation, etc. The AI-CIS can help people access intelligent services and plays a vital role in user-facing multimedia applications. + +# 7 Requirements of AI-based cognitive inference system for multimedia applications + +### 7.1 Requirements of AI-based cognitive inference capabilities + +- The system is recommended to have the capability to analyse and interpret multimedia data to extract information. +- The system is recommended to possess the ability to understand natural language, images and speech for inference tasks. + +- The system is recommended to ensure the interpretability and explainability of the inference results to users. + +## **7.2 Requirements of AI-based cognitive inference methods** + +- The system is required to employ machine learning and deep learning techniques for inference tasks. +- The system is recommended to support multimodal inference, including text, image and audio data processing. +- The system is recommended to have the capability to adapt and learn from new data to improve inference accuracy over time. + +## **7.3 Requirements of AI-based cognitive inference procedure** + +- The system is required to follow a systematic procedure for preprocessing from multimedia data. +- The system is recommended to utilize a modular and extensible architecture to facilitate inference processing. +- The system is required to ensure data privacy security throughout the inference procedure. +- The system is recommended to provide mechanisms for monitoring and evaluation of inference performance. +- The system is recommended to support integration with existing multimedia applications and systems. + +# **8 Framework of AI-based cognitive inference system for multimedia applications** + +The AI-CIS helps mining out more information from the multimedia data. The requirements in clause 7 are about the capabilities, methods and processes of AI-based cognitive inference system. In order to define the components AI-CIS and how it works; this clause defines the framework of AI-CIS for multimedia applications according to the requirements in clause 7. The framework of AI-based cognitive inference system for multimedia applications is shown in Figure 1. + +NOTE – In Figure 1, only the inference scope, which is in the blue box, is the scope of this Recommendation. + +![Figure 1: Framework of AI-based cognitive inference system for multimedia applications. The diagram shows a layered architecture. At the top are 'User front services' including Intelligent Recommendation, Intelligent customer service, Intelligent Q&A, Intelligent decision-making, and more. Below are 'Multimedia applications' including Natural language understanding, Image recognition, Speech recognition, Knowledge inference, and more. The central part is the 'Cognitive inference scope', which contains an 'Intelligent control module' at the top. Below it are three modules: 'Problem module' (with Problem acquisition and Problems deconstruction sub-modules), 'Problem status module' (with Problem status tracking and Problem status updating sub-modules), and 'Answer module' (with Answer inference and Answer validation sub-modules). To the right of the cognitive inference scope is a 'System management' section with 'System management' and 'System management module'. At the bottom is 'Data and knowledge' with a 'Database/Knowledge database'. A label 'F.748.65(25)' is at the bottom right.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +Figure 1: Framework of AI-based cognitive inference system for multimedia applications. The diagram shows a layered architecture. At the top are 'User front services' including Intelligent Recommendation, Intelligent customer service, Intelligent Q&A, Intelligent decision-making, and more. Below are 'Multimedia applications' including Natural language understanding, Image recognition, Speech recognition, Knowledge inference, and more. The central part is the 'Cognitive inference scope', which contains an 'Intelligent control module' at the top. Below it are three modules: 'Problem module' (with Problem acquisition and Problems deconstruction sub-modules), 'Problem status module' (with Problem status tracking and Problem status updating sub-modules), and 'Answer module' (with Answer inference and Answer validation sub-modules). To the right of the cognitive inference scope is a 'System management' section with 'System management' and 'System management module'. At the bottom is 'Data and knowledge' with a 'Database/Knowledge database'. A label 'F.748.65(25)' is at the bottom right. + +**Figure 1 – Framework of AI-based cognitive inference system for multimedia applications** + +### 8.1 Intelligent control module + +In a multi-modal or multi-task environment, this module enables effective collaboration between each sub-module, enabling the system to extract, integrate, and understanding advanced cognitive knowledge from various media information. + +## 8.2 Problem module + +This module contains two sub-modules, the problem acquisition module and the problem deconstruction module. + +#### 8.2.1 Problem acquisition module + +This module is mainly used to receive various forms of input from users, such as images, videos, audio, or text. + +### 8.2.2 Problem deconstruction module + +This module decomposes the problem into multiple sub-problems during problem deconstruction. This module is based on preset rules or machine learning models for real-time decision-making, parsing input multimedia data such as images, videos, audio or text. This module supports preprocessing and extraction of features from raw multimedia data, such as object detection in images, keyword recognition in speech or semantic analysis in text, transforming unstructured multimedia data into structured information that the system can further understand and reason about. Based on natural language processing technology, this module can recognize and understand queries or problems raised by users in various forms (speech, text, image annotations, etc.) and convert them into machine-readable expressions. + +### 8.3 Answer module + +This module consists of an answer inference module and an answer validation module. + +#### 8.3.1 Answer inference module + +Each problem is input into the answer inference module. Knowledge is obtained from a knowledge database and used to infer the answers to each problem. + +#### 8.3.2 Answer validation module + +The answer is input into the answer validation module to verify the answer to the problem. + +### 8.4 Problem status module + +This module consists of the problem status tracking module and problem status updating module. + +#### 8.4.1 Problem status tracking module + +This module supports tracking the process from the problem acquisition module to the problem deconstruction module, and then from the answer inference module to the answer validation module. + +#### 8.4.2 Problem status updating module + +After the answer validation module implementation is completed, the problem status updating module will close the current process and start processing new problems. + +# 9 Workflow of cognitive inference + +The cognitive inference workflow is divided into four steps, problem acquisition, problem deconstruction, answer inference and answer validation. The cognitive inference workflow is shown in Figure 2. + +![Figure 2 – Cognitive inference workflow diagram](ca7c7526ec57cd5a2f278c194c0a6a00_img.jpg) + +The diagram illustrates the cognitive inference workflow. At the top, 'Complex problems' enter the 'AI-based cognitive inference system' through the 'Problem acquisition' module. The system includes four main modules: 'Problem acquisition', 'Problem deconstruction', 'Answer inference', and 'Answer validation'. 'Status tracking' arrows connect 'Problem acquisition' to 'Problem deconstruction', 'Problem deconstruction' to 'Answer inference', and 'Answer inference' to 'Answer validation'. A 'Status updating' arrow connects 'Answer validation' back to 'Problem acquisition'. The 'Answer validation' module outputs the final 'Answer'. The 'Knowledge database' at the bottom is connected to the 'Answer inference' and 'Answer validation' modules. To the right, 'Multimedia applications' (Natural language understanding, Image recognition, Speech recognition, ...) are connected to the 'Problem deconstruction' module. + +Figure 2 – Cognitive inference workflow diagram + +F.748.65(25) + +**Figure 2 – Cognitive inference workflow** + +The first step, the problem acquisition module is used to obtain complex problems. The second step, the problem is split into multiple sub-problems in the problem deconstruction. In the third step, each sub-problem is entered into the answer inference module. In the answer inference module, knowledge is obtained from the knowledge database and is used to reason about the answers to each sub-problem. For the fourth step, the answer is entered into the answer validation module to verify the answer. + +Finally, the answer is output through the workflow. During this process, problem status tracking provides real-time feedback on the status of the problem. The entire workflow serves the multimedia applications. + +### 9.1 Problem acquisition + +This problem acquisition module is used to obtain complex problems. It is used to receive multiple forms of input such as images, videos, audio, or text from the user. This raw multimedia data can be transformed into a form that can be intelligently analysed and inferred. + +### 9.2 Problem deconstruction + +Based on the overall workflow, the problem is deconstructed in different ways. The problem deconstruction workflow is shown in Figure 3. + +![Figure 3 – Problem deconstruction workflow diagram. The diagram shows a central 'AI-based cognitive inference system' containing four main modules: 'Problem acquisition', 'Problem deconstruction', 'Answer inference', and 'Answer validation'. 'Problem acquisition' receives 'Complex problems' and sends 'Answers'. 'Problem deconstruction' (containing 'Chronological order' and '...') receives input from 'Problem acquisition' and sends input to 'Answer inference' (containing 'Time chain' and '...'). 'Answer inference' sends input to 'Answer validation'. 'Answer validation' sends input to 'Answers' and has a bidirectional connection to a 'Knowledge database'. Status tracking arrows connect 'Problem acquisition' to 'Problem deconstruction', 'Problem deconstruction' to 'Answer inference', and 'Answer inference' to 'Answer validation'. Status updating arrows connect 'Answer validation' to 'Problem acquisition' and 'Problem deconstruction'. The 'Knowledge database' contains 'Clauses', 'Regulations', 'Literature', and 'Common sense'. A 'Multimedia applications' box on the right contains 'Natural language understanding', 'Image recognition', 'Speech recognition', and '...'. A double-headed arrow connects the 'Multimedia applications' box to the 'Problem deconstruction' module.](7f17c430b9598e4d748a8041457810b3_img.jpg) + +Figure 3 – Problem deconstruction workflow diagram. The diagram shows a central 'AI-based cognitive inference system' containing four main modules: 'Problem acquisition', 'Problem deconstruction', 'Answer inference', and 'Answer validation'. 'Problem acquisition' receives 'Complex problems' and sends 'Answers'. 'Problem deconstruction' (containing 'Chronological order' and '...') receives input from 'Problem acquisition' and sends input to 'Answer inference' (containing 'Time chain' and '...'). 'Answer inference' sends input to 'Answer validation'. 'Answer validation' sends input to 'Answers' and has a bidirectional connection to a 'Knowledge database'. Status tracking arrows connect 'Problem acquisition' to 'Problem deconstruction', 'Problem deconstruction' to 'Answer inference', and 'Answer inference' to 'Answer validation'. Status updating arrows connect 'Answer validation' to 'Problem acquisition' and 'Problem deconstruction'. The 'Knowledge database' contains 'Clauses', 'Regulations', 'Literature', and 'Common sense'. A 'Multimedia applications' box on the right contains 'Natural language understanding', 'Image recognition', 'Speech recognition', and '...'. A double-headed arrow connects the 'Multimedia applications' box to the 'Problem deconstruction' module. + +F.748.65(25) + +**Figure 3 – Problem deconstruction workflow** + +#### 9.2.1 Deconstruction according to chronological order + +Break down the main problem into multiple sub-problems in chronological order. Search for relevant text content for each sub-problem in the multiple sub-problems. Forms the behaviour of each sub problem into a time chain in chronological order and then number each behaviour of each subject in chronological order. The time chain is formed in chronological order. The main problem is deconstructed in chronological order when there is a clear time point. When there is no clear time point, the main problem is breakdown according to the time related nodes. + +#### 9.2.2 Deconstruction in spatial order + +The main problem is broken down into sub-problems in spatial order. A plurality of object sub-regions is determined from the grey value of each pixel included in the object area of the identified video image, and the width pixel of the object area is determined by the width pixel of the plurality of the object sub-regions, i.e., the video can be the surveillance video. The width pixel ratio of the object area is determined by the width pixel of the object area and the width pixel of the video image. + +Based on the correspondence between the preset image detection model and the proportion interval, the target image detection model corresponding to the proportion interval of the width pixel proportion of the object area is determined from multiple image detection models. + +For any image detection model, the width pixel ratio of the object region included in each sample detection image is obtained in the training set used for model training of the image detection model. The initial scale interval corresponding to the image detection model is determined based on the maximum and minimum values of the width pixel ratio of the object region of the sample detection image. + +The use case of deconstruction in spatial order is shown in use case I.1 in Appendix I. + +### **9.3 Answer inference** + +#### **9.3.1 Retrieve problems in chronological order** + +In the answer inference module, knowledge related to sub-problems is searched based on the knowledge database, such as knowledge related clauses, information, etc. Search the criteria for determining each sub-problem in the knowledge database and judge the answers of multiple sub-problems based on their corresponding clauses or information. Search for relevant judgement criteria for each sub-problem in the multiple sub-problems. + +Determine the answer to each sub-problem based on the relevant text content of each sub-problem and the judgment criteria for determining each sub-problem in the multiple sub-problems. Forms a behavioural timeline for each subject in chronological order. Furthermore, based on the behavioural time chain of each subject, determine the answer to the corresponding question at each time point. Determine for relevant text content for each sub-problem in the multiple sub-problems. Finally, determine the answer to the main problems based on the answers to the sub-problems and the chronological order of each sub-problem. After the answer inference module, the answer is sent to the answer validation module for verification. + +Answer inference module refers to the use of natural language processing and reasoning technology to infer answers from a series of premises and knowledge through the logical relationship between questions and answers. It can be used to solve various problems including reasoning, inference, speculation, etc. For inference information, there is not only text information, but also image information feedback. Answer inference module can be used to solve problems related to three-dimensional face reconstruction, such as answering questions about three-dimensional face reconstruction methods, application fields, working principles, etc. Facial keypoint information contains keys used to represent identity information and/or motion information. + +For the three-dimensional face model reconstruction method, it extracts multi-scale face information of different receptive field sizes, face key point information and face sparse edge information from a single two-dimensional face image. Feature encoding is then performed on the extracted multi-scale face information. The feature-encoded multi-scale face information is spliced with a face key point information and face sparse edge information. Based on the spliced images, a feature-enhanced UV map is generated. The generated UV map is then subjected to a three-dimensional rendering processing to generate a three-dimensional face model with texture information. Based on the cascaded deep neural networks, facial key point information is extracted from two-dimensional facial images, i.e., the model can be based on a deep adaptation network (DAN). + +#### **9.3.2 Retrieve problems in spatial order** + +In the answer inference module, the answer inference module refers to using image inference and question answering to infer answers from a series of images. + +Based on the initial proportion interval corresponding to each image detection model, the target proportion interval corresponding to each image detection model is determined, and the target + +proportion interval corresponding to each image detection model do not overlap. A correspondence between the image detection model and the target scale interval is also established. + +If in the object area of the identified video image, there are multiple target pixels whose positions are adjacent and the grey value is within the preset range, the area composed of the multiple target pixels is determined as the object subarea, i.e., the video can be the surveillance video. The width pixel determination unit of the object area is used to determine multiple object subareas based on the gray value of each pixel included in the object area of the identified video image and determine the width pixels of the object area based on the width pixels of the multiple object subareas. The width pixel ratio unit of the object area is used to determine the width pixel ratio of the object area based on the width pixel of the object area and the width pixel of the video image. + +Based on the correspondence between the preset image detection model and the proportion interval, the target image detection model corresponding to the proportion interval of the width pixel proportion of the object area is determined from multiple image detection models. + +The recognition unit is used to identify a target object located on an object in the video image through the target image detection model, or to notify the edge device to determine the target image detection model, so that the edge device can recognize the target object located on the object in the video image through the target image detection model. + +### **9.4 Answer validation** + +The answer is entered into the answer validation module to verify the answer to the question, ensuring the correctness and reliability of the results. + +# Appendix I + +## Use cases of AI-based cognitive inference system for multimedia applications + +(This appendix does not form an integral part of this Recommendation.) + +### I.1 Use case of object detection + +In some urban areas, unpermitted construction poses significant challenges to city planning and resource management. Unauthorized buildings not only violate regulations but also compromise safety and environmental standards. Traditional methods of monitoring and identifying unpermitted structures are often time-consuming and resource intensive. + +By leveraging object detection technology, authorities can enhance their surveillance capabilities and streamline the detection process. Deploying cameras equipped with generalized models in strategic locations across urban areas enables real-time monitoring of construction activities. The system can automatically detect, and flag suspicious structures based on predefined criteria such as unauthorized location, size and construction materials. Figure I.1 shows the use case of object detection in land resource enforcement for detecting unpermitted construction. + +![Figure I.1: Four aerial photographs showing different types of unpermitted construction. Top-left: A large building under construction with a blue rectangular overlay highlighting its footprint. Top-right: A multi-story brick building with a blue roof. Bottom-left: A small building with a blue roof, partially obscured by trees. Bottom-right: A long, single-story building with a blue roof, situated near a road.](ace13edeb79bdfa129ed84fbb4ac44e5_img.jpg) + +Figure I.1: Four aerial photographs showing different types of unpermitted construction. Top-left: A large building under construction with a blue rectangular overlay highlighting its footprint. Top-right: A multi-story brick building with a blue roof. Bottom-left: A small building with a blue roof, partially obscured by trees. Bottom-right: A long, single-story building with a blue roof, situated near a road. + +**Figure I.1 – Use case of object detection in land resource enforcement for detecting unpermitted construction** + +### I.2 Use case of speech recognition + +In the field of journalism, reporters often conduct interviews or gather information through audio recordings. Transcribing these recordings manually can be time-consuming and prone to errors. However, with the advancements in speech recognition technology, the process can be streamlined and made more efficient. + +In such a scenario, a journalist transcribes an interview using a speech recognition system. By simply uploading the audio file to the system, the advanced algorithms analyse the speech patterns and convert the spoken words into an accurate text format. This significantly reduces the time and effort required for transcription, allowing journalists to focus more on authoring the article. + +Moreover, speech recognition enhances accessibility for individuals with hearing impairments. By converting spoken content into text, it enables them to access information that would otherwise be inaccessible. Figure I.2 shows the use case of speech recognition in transcription for converting audio to text. + +![Figure I.2: Use case of speech recognition in transcription for converting audio to text. The interface shows a 'Speech recognition system' with controls for 'Online real-time recording', 'Playback', 'Upload file', and 'Denoising'. It displays two waveforms: 'Original audio waveform' and 'Denoising audio waveform', each with a playback control. The 'Speech recognition result' panel on the right contains the text: 'Every tiny detail deserves the company's close attention. Only by correcting small deviations can the company achieve its grand goals.' The local time is 2023-09-21 10:12:15. A small code 'F.748.65(25)' is visible in the bottom right corner of the interface.](ad29805cd4f64ad2828e14feb66de664_img.jpg) + +Figure I.2: Use case of speech recognition in transcription for converting audio to text. The interface shows a 'Speech recognition system' with controls for 'Online real-time recording', 'Playback', 'Upload file', and 'Denoising'. It displays two waveforms: 'Original audio waveform' and 'Denoising audio waveform', each with a playback control. The 'Speech recognition result' panel on the right contains the text: 'Every tiny detail deserves the company's close attention. Only by correcting small deviations can the company achieve its grand goals.' The local time is 2023-09-21 10:12:15. A small code 'F.748.65(25)' is visible in the bottom right corner of the interface. + +**Figure I.2 – Use case of speech recognition in transcription for converting audio to text** + +### I.3 Use case of object segmentation + +In the field of autonomous driving, object segmentation as shown in Figure I.3 serves as a fundamental method. Due to the road sign and ground marking providing basic information for driving, autonomous driving should recognize these correctly. Therefore, segmenting these objects from a complex background becomes the prime step. + +By combining object segmentation and object recognition technology, the computation unit can get the right basic information such as turning direction and speed limit. Through deploying cameras equipped with generalized models, the in-vehicle system will perform accurate manoeuvres even without high-precision navigation system, driving in areas with weak communication signals. + +![Figure I.3: Use case of object segmentation in autonomous driving. The image shows a simulated street scene with a car, a bus, and several pedestrians. The objects are highlighted with colored overlays: the car is blue, the bus is green, and the pedestrians are red. The road is marked with yellow lines and signs.](a4d009d5dd6a4d83759d6d6538188e23_img.jpg) + +Figure I.3: Use case of object segmentation in autonomous driving. The image shows a simulated street scene with a car, a bus, and several pedestrians. The objects are highlighted with colored overlays: the car is blue, the bus is green, and the pedestrians are red. The road is marked with yellow lines and signs. + +**Figure I.3 – Use case of object segmentation in autonomous driving** + +## Bibliography + +- [b-ITU-T F.749.13] Recommendation ITU-T F.749.13 (2021), *Framework and requirements for civilian unmanned aerial vehicle flight control using artificial intelligence.* + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over 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It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.748.70 + +## Technical requirements of intelligent development tools for multimedia applications + +## Summary + +The term 'intelligent development tool' refers to software platforms or frameworks that leverage foundation models to automate and optimize the multimedia applications' development process. They can improve the development efficiency and product quality of multimedia applications, and stimulate innovation in the multimedia industry. + +Recommendation ITU-T F.748.70 specifies the requirements for the construction and application of intelligent development tools. It aims to guide enterprises in applying intelligent capabilities to develop multimedia applications. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.748.70 | 2025-12-14 | 21 | 11.1002/1000/16593 | + +## Keywords + +Artificial intelligence, development tools, multimedia applications. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2026 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-------------------------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 2 | +| 6 Framework of intelligent development tools for multimedia applications..... | 2 | +| 7 Requirements of software development intelligent agent ..... | 2 | +| 7.1 Technical capabilities ..... | 3 | +| 7.2 Service capabilities ..... | 3 | +| 8 Requirements of intelligent analysis and design ..... | 3 | +| 8.1 Requirements analysis ..... | 3 | +| 8.2 Requirements management ..... | 4 | +| 8.3 Function design ..... | 4 | +| 9 Requirements of intelligent development..... | 4 | +| 9.1 Smart coding..... | 4 | +| 9.2 Code quality check ..... | 6 | +| 9.3 Developer assistance ..... | 6 | +| 10 Requirements of intelligent testing..... | 8 | +| 10.1 Test design..... | 8 | +| 10.2 Test execution..... | 9 | +| 10.3 Test evaluation..... | 10 | +| 11 Requirements of intelligent deployment and operation maintenance..... | 11 | +| 11.1 Intelligent deployment..... | 12 | +| 11.2 Intelligent monitoring..... | 12 | +| 11.3 Intelligent repair ..... | 12 | +| Bibliography..... | 13 | + + + +# Recommendation ITU-T F.748.70 + +## Technical requirements of intelligent development tools for multimedia applications + +## 1 Scope + +This Recommendation focuses on the technical requirements of intelligent development tools for multimedia applications. It addresses the following aspects: + +- The requirements of software development intelligent agents; +- The requirements of intelligent analysis and design; +- The requirements of intelligent development; +- The requirements of intelligent testing; +- The requirements of intelligent deployment and operation maintenance. + +The decommissioning phase is not addressed in this Recommendation. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 artificial intelligence** [b-ISO/IEC 2382]: An interdisciplinary field, usually regarded as a branch of computer science, dealing with models and systems for the performance of functions generally associated with human intelligence, such as reasoning and learning. + +**3.1.2 AI agent** [b-ISO/IEC 22989]: Automated entity that senses and responds to its environment and takes actions to achieve its goals + +### 3.2 Terms defined in this Recommendation + +None. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|-----------------------------------| +| AI | Artificial intelligence | +| API | Application Programming Interface | +| HTML | Hypertext Markup Language | + +| | | +|-----|----------------------------| +| Q&A | Question and Answer | +| UI | User Interface | +| XML | Extensible Markup Language | + +## 5 Conventions + +In this Recommendation: + +- The keywords "**is required to**" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. +- The keywords "**is recommended**" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement needs not be present to claim conformance. + +## 6 Framework of intelligent development tools for multimedia applications + +The framework of intelligent development tools for multimedia applications refers to the requirements of artificial intelligence technologies and tools based on foundation models throughout the entire development process of multimedia applications. The framework encompasses four key phases of the intelligent software lifecycle: intelligent analysis and design, intelligent development, intelligent testing, and intelligent deployment and operations maintenance. It also specifies the technical requirements for implementing software development intelligent agents across the lifecycle. The structure of the intelligent development tools for multimedia applications and its related components is illustrated in Figure 1. + +![Figure 1: Framework of intelligent development tools for multimedia applications. The diagram is structured into three horizontal layers. The top layer, 'Multimedia applications', includes icons and lists for Image production (beautification, classification), Speech recognition (music player, processing), Video player (generation, clip), and Text translation (understanding, generation). The middle layer, 'Technical requirements of intelligent development tools for multimedia applications', features a 'Software development intelligent agent' box split into 'Technical capabilities' and 'Service capabilities'. The bottom layer contains four boxes representing lifecycle phases: 'Intelligent analysis and design' (requirements analysis, verify, function design), 'Intelligent development' (smart coding, quality check, assistance), 'Intelligent test' (design, execution, evaluation), and 'Intelligent deployment and operation maintenance' (deployment, monitor, repair).](5860ad6bd2a2dd8d1ab12864b8f90f37_img.jpg) + +Figure 1: Framework of intelligent development tools for multimedia applications. The diagram is structured into three horizontal layers. The top layer, 'Multimedia applications', includes icons and lists for Image production (beautification, classification), Speech recognition (music player, processing), Video player (generation, clip), and Text translation (understanding, generation). The middle layer, 'Technical requirements of intelligent development tools for multimedia applications', features a 'Software development intelligent agent' box split into 'Technical capabilities' and 'Service capabilities'. The bottom layer contains four boxes representing lifecycle phases: 'Intelligent analysis and design' (requirements analysis, verify, function design), 'Intelligent development' (smart coding, quality check, assistance), 'Intelligent test' (design, execution, evaluation), and 'Intelligent deployment and operation maintenance' (deployment, monitor, repair). + +F.748.70(25) + +**Figure 1 – Framework of intelligent development tools for multimedia applications** + +## 7 Requirements of software development intelligent agent + +The software development intelligent agent is an artificial intelligence (AI) agent designed to perform or assist in tasks within the software development domain. It applies to an AI-agent based autonomous system capable of end-to-end software development task execution – from requirement decomposition to code delivery – by leveraging perception, memory, planning, and execution capabilities. + +### 7.1 Technical capabilities + +Technical capabilities refer to the AI agent's abilities to perceive and parse input information, store and retrieve historical data in memory, plan and decompose tasks to formulate strategies, and execute operations using tools to validate results. + +- a) It is required to be capable of perceiving and understanding the context, e.g., code context, requirement document context and user feedback context. +- b) It is required to maintain short-term memory for storing question-and-answer records and background knowledge. +- c) It is required to break down complex tasks into smaller subtasks. +- d) It is required to support task planning capability, enabling the prioritization and sequencing of task execution to ensure efficient workflow management. +- e) It is required to invoke various software development tools to execute tasks, e.g., file reading tools and code execution tools. +- f) It is required to identify and select tools based on development requirements. +- g) It is required to invoke tools through a unified tool interface protocol. +- h) It is recommended to analyse a code repository to comprehend the overall project functionality and identify structural architecture. +- i) It is recommended to implement a long-term memory mechanism to retain key knowledge, experiences and skills for cross-time knowledge accumulation. +- j) It is recommended to be capable of reasoning and planning based on program code or pseudocode. + +### 7.2 Service capabilities + +Service capabilities refer to the AI agent's abilities to complete the end-to-end software development tasks based on code semantics and user requirements. + +- a) It is required to be capable of generating and editing code, and saving code files. +- b) It is required to generate test cases that comply with the framework specifications. +- c) It is required to schedule and execute the unit test cases and obtain the execution results. +- d) It is required to analyse code review comments and provide repair suggestions. +- e) It is recommended to implement code prediction functionality based on context to provide proactive and intelligent assistance. +- f) It is recommended to build local runtime environments and execute code. +- g) It is recommended to support automatically fixing and optimizing incorrect unit test cases. +- h) It is recommended to generate incremental unit test cases based on the changed code. +- i) It is recommended to verify the repaired code to ensure the correctness of the repairs. + +## 8 Requirements of intelligent analysis and design + +Intelligent analysis and design capability refers to implement artificial intelligence technologies to analyse, confirm and manage software requirements, and to generate system architecture, interface definitions. + +### 8.1 Requirements analysis + +The requirements analysis capability refers to the ability to organize, analyse and refine the acquired requirements, as well as to identify conflicts, judge feasibility and prioritize them. + +- a) It is required to understand and parse requirements to extract key intents. + +- b) It is required to identify defects and contradictions in development requirements, e.g., ambiguous statements, missing information and inconsistent functional descriptions. +- c) It is required to recognize dependencies between requirements to illustrate the interrelationships. +- d) It is required to prioritize software development requirements. +- e) It is recommended to decompose requirements based on technical feasibility, cost-effectiveness. +- f) It is recommended to adjust requirements documentation and mark the revisions based on inputs from requirement changes. + +### **8.2 Requirements management** + +The requirements management capability refers to maintaining the consistency, traceability and version control of requirements based on artificial intelligence technologies. + +- a) It is required to conduct traceability analysis of requirements and examine the change history of requirement items. +- b) It is required to analyse the differences between changes of overall requirements version, and assess their impact. +- c) It is required to be capable of exporting the requirement documents. +- d) It is recommended to be capable of tracing requirements to their corresponding designs and code. +- e) It is recommended to generate requirement changes based on code or design modifications. + +### **8.3 Function design** + +The function design capability refers to applying artificial intelligence technologies to generate system architectures, module divisions, interface definitions, algorithms and detailed processes based on requirements. + +- a) It is required to generate system framework and module design based on requirements. +- b) It is required to recommend technology framework according to requirements. +- c) It is required to generate and recommend the main application programming interface (API) designs. +- d) It is required to generate database schema to define the database structure. +- e) It is required to generate class diagrams to present the static structure of system. +- f) It is recommended to generate digital prototyping to simulate application interfaces and workflows. +- g) It is recommended to complete the module and core interface changes according to the design changes. +- h) It is recommended to evaluate the feasibility and performance of the architecture design. + +## **9 Requirements of intelligent development** + +Intelligent development refers to the application of artificial intelligence technologies to automate and enhance software engineering processes – including code generation, completion, translation, and optimization – while ensuring code quality through continuous inspection and validation. + +### **9.1 Smart coding** + +Smart coding refers to applying artificial intelligence (AI) capabilities to intelligently generate code or natural language outputs that meet requirements based on input instructions. + +#### **9.1.1 Code generation and completion** + +Code generation and completion refer to the ability to automatically generate and complete code based on natural language descriptions or code context. + +- a) It is required to support multi-programming languages and multi-development frameworks. +- b) It is required to generate code snippets based on natural language descriptions. +- c) It is required to complete references, class names, method names and function names based on context awareness. +- d) It is recommended to generate single-file and multi-file source code based on natural language descriptions. +- e) It is recommended to generate code based on multimodal inputs, e.g., natural language, user interface (UI) mock-up images and video demonstrations of workflows. +- f) It is recommended to leverage cross-context awareness to facilitate code generation and completion based on existing code and natural language descriptions. +- g) It is recommended to modify and adapt existing code to meet user-specified requirements. + +#### **9.1.2 Code transcoding and optimization** + +Code transcoding and optimization involve using artificial intelligence technologies to convert code among different languages or frameworks to optimize code and enhance its performance, while maintaining the original code logic and functional behaviour. + +- a) It is required to support code translation among multiple programming languages based on given code snippets. +- b) It is required to format code optimizations, e.g., line length adjustments and irregular naming conventions. +- c) It is required to analyse and optimize code to improve the computational complexity and execution efficiency. +- d) It is required to provide context-aware code optimization suggestions. +- e) It is recommended to support code conversion across different frameworks or development environments. +- f) It is recommended to support automatic code transformations among different programming paradigms. +- g) It is recommended to reorganize and rewrite code within the same language. + +#### **9.1.3 Code interpretation and commentary** + +Code interpretation and commentary refer to using artificial intelligence technologies to interpret or generate comments for existing code, helping developers understand the code and enhancing its readability and maintainability. + +- a) It is required to provide explanations and annotations for codes e.g., explanations of algorithmic code, snippet-level code. +- b) It is required to interpret functional code blocks to support developers to understand code intent and execution flow. +- c) It is recommended to optimize existing comments to enhance their clarity and coherence. +- d) It is recommended to comprehend multi-file-level code and generate technical documentation, e.g., architecture design documents. + +### 9.2 Code quality check + +Code quality check refers to apply AI capabilities to inspect code for quality issues, provide repair suggestions, or carry out repairs, helping developers improve code quality and enhance code repair efficiency. + +#### 9.2.1 Static code check + +Static code check refers to the process of automatically examining source code prior to execution to identify potential issues, helping developers improve code quality and reduce runtime errors. + +- a) It is required to detect code standardization violations and code smells, e.g., non-compliant code, redundant code, excessively long functions and uncalled functions. +- b) It is required to check syntax errors, e.g., mismatched brackets and incorrect syntax structures. +- c) It is required to check type errors, e.g., type mismatches and incorrect type usage. +- d) It is required to detect logical errors, e.g., flaws in conditional statement logic and incorrect loop termination conditions. +- e) It is required to check exceptions, e.g., null pointer references and array index out-of-bounds errors. +- f) It is recommended to support static analysis of multi-threading and asynchronous code to detect potential static errors and issues. + +#### 9.2.2 Dynamic code check + +Dynamic code check refers to examining and analysing code during execution to discover potential runtime errors, helping developers find and fix runtime issues, thereby improving code stability and reliability. + +- a) It is required to detect runtime memory issues. +- b) It is required to detect runtime performance issues, e.g., excessive resource consumption, inefficient operations and performance bottlenecks. +- c) It is required to support code performance analysis, e.g., assessment of algorithms, data structures, resource utilization and response times. +- d) It is recommended to implement exception localization and remediation by leveraging runtime diagnostics to identify and resolve defects. +- e) It is recommended to implement real-time interception and alerting mechanisms that detect potential runtime attacks and provide remediation suggestions. + +### 9.3 Developer assistance + +Developer assistance refers to helping developers carry out coding tasks, e.g., code search, code question and answer (Q&A) and development document generation. + +#### 9.3.1 Code search + +Code search refers to applying artificial intelligence technologies to help developers locate the required code, e.g., keyword analysis and semantic understanding. + +- a) It is required to support keyword-based searching, enabling code retrieval through class names, dependencies and comments. +- b) It is required to support semantic search, enabling the retrieval of relevant code through understanding natural language descriptions in different languages and functional requirements and dependency relationships. + +- c) It is required to support code snippet search, capable of identifying similar code segments across different programming languages. +- d) It is required to support external code repository search, including integration with public code platforms and open-source communities to retrieve relevant code. +- e) It is recommended to support private code repository search, enabling customized retrieval across different project teams and departments within enterprise internal code bases while providing differentiated search permissions. +- f) It is recommended to support interactive cross-repository search and result navigation. + +#### 9.3.2 Code question and answer (Q&A) + +Code question and answer (Q&A) refers to answering research and development questions, providing developers with question-and-answer assistance capabilities and improving research and development efficiency. + +- a) It is required to respond to natural language queries with accurate answers. +- b) It is required to respond to development questions about programming languages. +- c) It is required to support semantic interpretation, e.g., explaining code logic, interpreting compilation and runtime errors and performing comparative analysis of code changes. +- d) It is required to respond to code generation queries, e.g., code completion, error correction, refactoring and optimization. +- e) It is required to support multi-round dialogue and reasoning, enabling context-aware conversations and targeted responses based on prompts. +- f) It is recommended to provide code recommendation capabilities that suggest sample code, documentation, or resources based on problem descriptions. +- g) It is recommended to enable the display of reference sources for reasoning-based answers. +- h) It is recommended to respond to questions related to the development life cycle, e.g., requirements analysis, coding, testing, deployment and maintenance. +- i) It is recommended to support analysis of compilation or runtime error messages and provide repair suggestions. +- j) It is recommended to support multimodal Q&A capabilities, allowing interaction through multi data formats, e.g., natural language, voice and images. + +#### 9.3.3 Development document generation + +Development document generation refers to assisting developers in writing development documents by leveraging AI ability, enhancing the interpretability and maintainability of code. + +- a) It is required to support the generation of application programming interface (API) documentation based on source code. +- b) It is required to support the generation of development documentation, including business logic, functional implementation and dependency relationships. +- c) It is required to support the generation of documents in multiple formats, e.g., .pdf, .docx, .txt. +- d) It is required to implement document templating, enabling the generation of documents to ensure a consistent structure and format. +- e) It is required to automatically filter sensitive information (e.g., usernames, passwords) in development documentation to ensure security. +- f) It is recommended to generate code change logs, including comparative analysis of code before and after changes based on modification content, impact scope and severity level. + +- g) It is recommended to support development documentation error correction to enhance documentation quality. +- h) It is recommended to support personalized customization for documentation templates. + +## **10 Requirements of intelligent testing** + +### **10.1 Test design** + +Test design refers to the formulation of testing strategies, test cases and test scenarios by leveraging artificial intelligence technologies (e.g., large model), based on the characteristics and requirements of the software under test, to enhance testing efficiency, coverage and accuracy. + +#### **10.1.1 Test plan generation** + +Test plan generation refers to the development of a comprehensive test plan based on software requirements and design specifications. A typical test plan includes testing strategies and methodologies, scope of testing, test objectives and targets, testing environment, schedule, expected outcomes and evaluation criteria. It provides guidance and a structured framework for subsequent testing activities. + +- a) It is required to generate standardized document, enabling test plan formatting compliance through uploaded or configured templates. +- b) It is required to implement document security filtering to redact input fields, ensuring the security of generated documents. +- c) It is required to generate a test plan encompassing test objectives, scope, environment, cases and timelines. +- d) It is required to support test type planning to evaluate testing requirements of the system under test, e.g., functional, performance, compatibility, stability, security, fault tolerance, and privacy. +- e) It is recommended to generate multimodal test plans that derive test strategies from diverse input sources, including requirements documents, design specifications, diagrams, flowcharts, and other development artifacts. +- f) It is recommended to automatically analyse task characteristics, priority classification, executor skill sets and resource availability, enabling intelligent test task allocation and resource optimization. +- g) It is recommended to support intelligent risk assessment, e.g., evaluation of personnel risks, compliance risks and collaboration risks. +- h) It is recommended to support test scenario construction, simulating real-world user behaviors and environmental variations to enhance testing accuracy and reliability. + +#### **10.1.2 Test point analysis** + +Test point analysis refers to the automatic identification of critical verification points – functional requirements, performance aspects, boundary conditions and other aspects – by leveraging artificial intelligence technologies based on given software requirement documents and design documents. + +- a) It is required to generate test points from multimodal input support, e.g., natural language descriptions, source code and documentation. +- b) It is required to generate test points covering common software usage scenarios. +- c) It is required to support analysis of fundamental test scenarios, e.g., positive cases, negative cases, boundary conditions and exception handling validations. +- d) It is required to support analysis of non-functional attributes, e.g., performance, security and compatibility along with corresponding test point generation. + +- e) It is recommended to identify and extract test points from multimodal input, including requirements documents, design specifications, diagrams, flowcharts. +- f) It is recommended to implement test point analysis to identify domain-specific test points, hidden logical branches and exceptional workflows. +- g) It is recommended to support test point risk assessment with corresponding risk mitigation measure proposals. + +#### **10.1.3 Test case generation** + +Test case generation refers to the creation of test cases covering software functionality, performance, reliability, and other aspects by leveraging artificial intelligence technologies based on given requirement documents and software design specifications. + +- a) It is required to generate multiple test case types, e.g., functional testing, security testing, performance testing. +- b) It is required to generate customized test case output formats. +- c) It is required to integrate with automated testing frameworks to generate framework-compliant test cases. +- d) It is recommended to generate test case based on multimodal input, e.g., requirements documents, design specifications, diagrams and flowcharts. +- e) It is recommended to generate test cases that are applicable to mobile, web, desktop applications platforms to ensure cross-platform compatibility. +- f) It is recommended to optimize existing test cases to enhance completeness and test coverage. + +### **10.2 Test execution** + +Test execution refers to automated generating, scheduling and executing test script, and handling test excepting by leveraging artificial intelligence technologies (e.g., large model), to improve testing efficiency and accuracy. + +#### **10.2.1 Test script generation** + +Test script generation refers to the automatic creation of executable test scripts based on test cases by leveraging artificial intelligence technologies, with the aim of improving script generation efficiency and reducing testing costs. + +- a) It is required to support multiple programming languages and testing frameworks. +- b) It is required to generate test script based on test cases, natural language descriptions, requirements documents and design specifications. +- c) It is required to generate test code across multiple testing dimensions, e.g., unit testing, interface testing, user interface (UI) testing. +- d) It is required to generate test code that complies with quality standards and security requirements. +- e) It is required to generate executable test scripts with baseline operational capability. +- f) It is recommended to generate test scripts from multimodal inputs (e.g., text, speech, images, video files and database files). +- g) It is recommended to generate test assertions to ensure validation accuracy. + +#### **10.2.2 Test case execution** + +Test case execution refers to the automated recommendation, scheduling and execution of corresponding test scripts based on the test plan and test cases, by leveraging artificial intelligence technologies, with the aim of improving the efficiency of test execution. + +- a) It is required to execute test scripts for multiple testing types, e.g., unit testing, interface testing, UI testing. +- b) It is required to generate test case execution records, process logs and analytical reports. +- c) It is recommended to support automated test cases and scripts recommendation and selection based on defect descriptions, requirement changes and test results. +- d) It is recommended to execute test script across multiple testing dimensions, e.g., functional testing, performance testing, security testing. +- e) It is recommended to support environment validation capabilities to verify connectivity, configuration correctness and operational readiness. + +#### **10.2.3 Test exception handling** + +Test exception handling refers to the monitoring, identification, and resolution of unexpected issues encountered during test execution, by leveraging artificial intelligence technologies, with the aim of improving the pass rate of test execution. + +- a) It is required to support customizable exception definition, allowing the configuration of diverse exception types. +- b) It is required to support exception monitoring, allowing tracking of execution logs, identification of anomalies and recording of diagnostic data. +- c) It is required to generate automated exception reports, encompassing exception classification, occurrence frequency, root cause analysis and remediation status. +- d) It is recommended to support exception alerting, allowing timely notification of relevant personnel when exceptions occur. +- e) It is recommended to support exception remediation, allowing analysis of common exceptions and provision of repair recommendations. + +### **10.3 Test evaluation** + +Test evaluation refers to automated analysing test results, generating test reports and reviewing the testing process by leveraging artificial intelligence technologies. + +#### **10.3.1 Test result analysis** + +Test result analysis refers to statistical processing and interpretation of test execution data by leveraging artificial intelligence technologies after each testing phase, to evaluate testing processes and identify potential issues. + +- a) It is required to collect, store and integrate test execution data from multiple testing frameworks, tools and platforms. +- b) It is recommended to support metric definition and calculation, allowing configuration of key metrics for test result evaluation. +- c) It is required to support test result data visualization through graphical formats to present analytical findings. +- d) It is recommended to support test result analysis, e.g., issue localization, risk trend analysis, optimization recommendations, efficiency evaluation and decision support. +- e) It is recommended to support multi-dimensional result analysis to conduct evaluations across different test cycles, functional modules, and testing types for comprehensive test insight generation. + +#### **10.3.2 Test report generation** + +Test report generation refers to the process of creating the test report at the end of the software testing cycle, based on test results by leveraging artificial intelligence technologies (e.g., large model). The + +report typically includes documentation, project information, testing resources, test environment, test scope, testing schedule, testing strategies, specialized tests, defect information, execution result analysis and test conclusions. + +- a) It is required to generate multilingual report in natural languages. +- b) It is required to support structured and template-based test report generation with template upload functionality. +- c) It is required to generate multi-format report, e.g., hypertext markup language (HTML), extensible markup language (XML), markdown. +- d) It is required to generate standardized test reports containing mandatory sections, e.g., project information, test resources, test environment, test scope, test cycle, execution result analysis and test conclusions. +- e) It is required to support comparative analysis and test results summarization across different time periods or test rounds. +- f) It is recommended to generate customized and diversified reports, e.g., performance test reports, security test reports and other specialized variants tailored to user requirements, preferences, styles, types and target roles. +- g) It is recommended to generate multimodal data visualization reports, e.g., defect distribution maps, defect density charts and test result comparison diagrams. +- h) It is recommended to generate advanced test reports including risk assessments, process improvement recommendations, quality enhancement suggestions, historical trend analysis, user behaviour reports, performance and load analysis. + +#### 10.3.3 Test review + +Test review refers to the examination and evaluation of relevant deliverables in the testing process, based on artificial intelligence technologies, to provide optimization suggestions. + +- a) It is required to enable test plan review capability to assess documentation compliance with standards, verify test scope alignment to requirements and evaluate the feasibility of schedules and resource allocation. +- b) It is required to support test case review capability to evaluate key dimensions (e.g., readability, coverage). +- c) It is required to support test report review capability to examine report standardization, completeness and content validity including test execution processes, test results. +- d) It is recommended to support automated test plan optimization based on review feedback. +- e) It is recommended to support test case review and optimization capabilities, including analysis of uncovered scenarios or functional points with automated generation of additional test cases to address identified gaps. +- f) It is recommended to support test environment review covering production-environment consistency validation, completeness of monitoring solutions, integrity of backup/deployment mechanisms, and security compliance evaluation. + +## 11 Requirements of intelligent deployment and operation maintenance + +Intelligent deployment and operation maintenance refers to the automated construction, deployment and release of software based on artificial intelligence technologies, while also monitoring operating data in real time, automatically detecting anomalies and completing repairs. + +### **11.1 Intelligent deployment** + +The intelligent deployment capability refers to the use of artificial intelligence technologies to automatically generate configuration files and deployment instructions, so as to complete the automatic release and optimization of software. + +- a) It is required to support the automatic generation of deployment plans. +- b) It is required to generate configuration files for containerized environments. +- c) It is required to generate deployment rollback scripts. +- d) It is required to support the automatic identification of errors during execution. +- e) It is recommended to support the generation of cluster and high-availability deployment schemes. +- f) It is recommended to generate different deployment configurations for multiple environments. +- g) It is recommended to support automatic optimization based on deployment feedback. + +### **11.2 Intelligent monitoring** + +The intelligent monitoring capability refers to monitoring of the operating status of software and detecting abnormal events of the monitored objects based on the collected operating status data. + +- a) It is required to collect data from various monitored objects. +- b) It is required to support abnormal message notifications through multiple methods. +- c) It is required to support multi-granularity monitoring data collection to enable fine-grained analysis. +- d) It is recommended to support multimodal data collection (e.g., images, reports and voices). +- e) It is recommended to classify detected abnormal events into different levels and assign corresponding handling procedures. +- f) It is recommended to predict potential abnormal events based on historical data. + +### **11.3 Intelligent repair** + +The intelligent repair capability enables automatic fault resolution by analysing anomaly events, integrating troubleshooting procedures, and triggering automated tools to repair. + +- a) It is required to invoke automated operation and maintenance tools to execute the commands specified in the fault disposal plan. +- b) It is required to support the verification of operation and maintenance commands and repair results. +- c) It is required to automatically break after multiple failed attempts. +- d) It is required to generate fault repair reports. +- e) It is recommended to support detailed analysis of the fault repair process and results. +- f) It is recommended to support multi-stage repair through understanding the contextual dependencies of each sub-phase. +- g) It is recommended to support visual display the status of the repair process. + +## Bibliography + +- [b-ISO/IEC 2382] ISO/IEC 2382:2015, *Information technology – Vocabulary.* +- [b-ISO/IEC 22989] ISO/IEC 22989:2022, *Information technology – Artificial intelligence – Artificial intelligence concepts and terminology.* + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| 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It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.748.71 + +# Requirements and functional architecture of artificial intelligence (AI) model generalization system for telecommunication intelligent customer service + +## Summary + +Artificial intelligence (AI) models have been used in a variety of industries, bringing new changes to the industry. With the development of telecommunications, applying AI technology to telecommunication intelligent customer service (TICS) has become a trend. + +Recommendation ITU-T F.748.71 identifies the requirements and functional framework of an AI model generalization system for TICS, which supports efficient annotation of massive data and can handle multimedia data. AI model generalization system (MGS) supports rapid adaptation to tasks through fine-tuning and achieves the sharing and reuse of AI capabilities. Customer service-oriented models could be created by analysing and understanding multiple types of data for comprehensive analysis of multiple scenarios. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.748.71 | 2025-12-14 | 21 | 11.1002/1000/16594 | + +## Keywords + +Fine-tune, model generalization, model inference, pre-training, telecommunication intelligent customer service. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2026 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-----------------------------------------------------------------------------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Overview of AI model generalization system for telecommunication intelligent customer service ..... | 2 | +| 6.1 Introduction to AI model generalization system for telecommunications intelligent customer service ..... | 2 | +| 6.2 Workflow of the AI model generalization system for telecommunication intelligent customer service ..... | 3 | +| 7 Requirements of AI model generalization system for telecommunication intelligent customer service ..... | 4 | +| 7.1 Requirements for multimedia data processing ..... | 4 | +| 7.2 Requirements for model generation ..... | 4 | +| 7.3 Requirements for model verification..... | 5 | +| 7.4 Requirements for task processing module..... | 5 | +| 7.5 Applicable system security ..... | 5 | +| 8 Functional architecture of AI model generalization system for telecommunication intelligent customer service ..... | 6 | +| 8.1 Functions of the multimedia data processing module ..... | 6 | +| 8.2 Functions of the model generation module ..... | 6 | +| 8.3 Functions of model verification module..... | 7 | +| 8.4 Functions of the task processing module..... | 7 | +| 8.5 Intelligent customer service..... | 7 | +| Appendix I – Use cases of AI model generalization system in telecommunication intelligent customer service ..... | 8 | +| I.1 Use case of AI model generation of telecommunication intelligent customer service for network operation and maintenance ..... | 8 | +| I.2 Use case of AI model generation of telecommunication intelligent customer service for fault handling ..... | 9 | +| Bibliography..... | 10 | + + + +# Recommendation ITU-T F.748.71 + +## Requirements and functional architecture of artificial intelligence (AI) model generalization system for telecommunication intelligent customer service + +# 1 Scope + +This Recommendation identifies the requirements and functional architecture of an artificial intelligence (AI) model generalization system (MGS) for telecommunication intelligent customer service (TICS). + +The scope of this Recommendation includes: + +- Overview of MGS for TICS. +- Requirements of MGS for TICS. +- Functional architecture of MGS for TICS. + +Use cases of MGS in TICS are provided in Appendix I. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[\[ITU-T F.748.43\]](#) Recommendation ITU-T F.748.43 (2025), *Framework and requirements for the foundation model platform*. + +[\[ITU-T X.1470\]](#) Recommendation ITU-T X.1470 (2021), *Security guidelines of web-based online customer service*. + +[\[ITU-T X.1771\]](#) Recommendation ITU-T X.1771 (2024), *Security guidelines for combining de-identified data using trusted third party*. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 artificial intelligence (AI)** [b-ISO/IEC 2382]: An interdisciplinary field, usually regarded as a branch of computer science, dealing with models and systems for the performance of functions generally associated with human intelligence, such as reasoning and learning. + +**3.1.2 intelligent customer service** [b-ITU-T F.748.25]: Customer service with intelligent capabilities, which is composed of some or all of the artificial intelligence technology capabilities such as speech recognition, natural language processing, intelligent search, and text-to-speech synthesis. + +**3.1.3 intelligent customer service system** [b-ITU-T F.746.16]: A customer service system based on natural language processing, speech recognition, text to speech and other artificial intelligence technologies. After converging the user's questions through single or multiple rounds of conversation, + +the intelligent customer service system relies on a maintained background knowledge base and interface components to realize intelligent dialogue. + +## **3.2 Terms defined in this Recommendation** + +None. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|------------------------------------------------| +| AI | Artificial Intelligence | +| ICS | Intelligent Customer Service | +| MDPM | Multimedia Data Processing Module | +| MGM | Model Generation Module | +| MGS | Model Generalization System | +| MVM | Model Verification Module | +| O&M | Operation and Maintenance | +| SLA | Service Level Agreement | +| TICS | Telecommunication Intelligent Customer Service | +| TPM | Task Processing Module | + +# **5 Conventions** + +In this Recommendation, the following conventions apply: + +The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted, if conformance to this Recommendation is to be claimed. + +The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +# **6 Overview of AI model generalization system for telecommunication intelligent customer service** + +## **6.1 Introduction to AI model generalization system for telecommunications intelligent customer service** + +TICS refers to an intelligent customer service (ICS) for telecommunication domain, which leverages artificial intelligence technology to interact with users across multiple channels, address routine inquiries like bill checks and plan adjustments, and collaborate with human agents for complex issues. TICS includes scenarios such as speech recognition, work order processing, knowledge question and answer, which involve multimedia data such as images, video and text. The introduction of AI technology helps to handle data of TICS, solve scenario applications, improve customer service efficiency and reduce the reliance on manual labour. + +The MGS for TICS can process the multimedia data, realize model pre-training and model fine-tuning for different tasks, and the fine-tuned models can be used in the scenarios of customer service. MGS for TICS includes large-scale, pre-trained, generalized artificial intelligence models. MGS for TICS is a system based on the ability of data processing, model generation, model evaluation and model verification, which can generate AI models for TICS. + +This Recommendation introduces an MGS for TICS. The system can provide a complete model generation capability, including data collection, data processing, data annotation, model training, model inference, model verification and model optimization. The MGS supports efficient annotation of massive data and can handle multimedia data at the same time. The system supports rapid adaptation to tasks through fine-tuning and achieves the sharing and reuse of AI capabilities. The system provides model performance tracking and model optimization capabilities to meet requirements of customer service scenarios. The customer service-oriented models could be created by analysing and understanding multiple types of data for comprehensive analysis of multiple scenarios. For example, MGS for TICS could provide customer service for network operation and maintenance, and fault handling. + +## 6.2 Workflow of the AI model generalization system for telecommunication intelligent customer service + +Figure 6-1 shows the workflow of MGS for TICS + +![Flowchart of the MGS for TICS workflow, showing 9 steps from Start to End, with a feedback loop from Step 8 to Step 5.](b3baf3a29b67c7425d2562ddbc52f0cc_img.jpg) + +``` +graph TD; Start((Start)) --> S1[Step 1: Data collection]; S1 --> S2[Step 2: Data processing]; S2 --> S3[Step 3: TICS dataset generation]; S3 --> S4[Step 4: Model pre-training]; S4 --> S5[Step 5: Model fine-tuning]; S5 --> S6[Step 6: Model verification]; S6 --> S7{Step 7: Meet demands?}; S7 -- Y --> S9[Step 9: Provide TICS services]; S7 -- N --> S8[Step 8: Dataset generated during the verification process]; S8 --> S5; S9 --> End((End)); +``` + +Flowchart of the MGS for TICS workflow, showing 9 steps from Start to End, with a feedback loop from Step 8 to Step 5. + +F.748.71(25) + +**Figure 6-1 – Workflow of MGS in TICS** + +There are nine steps: + +- Step 1: Data collection. Collect the TICS-related data including telecommunication data from the telecommunication system and general data. +- Step 2: Data processing. Utilize methods including data cleaning, data classification, data standardization and data fusion to process the collected data. +- Step 3: TICS dataset generation. Arrange the processed data to generate the pre-training dataset and fine-tuning datasets. +- Step 4: Model pre-training. Pre-train the model with unsupervised learning methods based on the pre-training dataset. +- Step 5: Model fine-tuning. Fine-tune the pre-trained model with supervised learning methods based on fine-tuning datasets. + +- Step 6: Model verification. Verify model capabilities and performance in a virtual telecommunication customer service environment. +- Step 7: Meet demands. Determine whether the model meets the customer service demands. If 'no', go to step 8, if 'yes', go to step 9. +- Step 8: Dataset generated during the verification process. Form a dataset based on the verification process. For example, the virtual task environment generated a telecommunication-related service request, and the model generate a corresponding answer which is not satisfied, then the satisfactory answer is required to create. The Question-Answer pairs are the piece of data in the dataset. Then go to step 5. +- Step 9: Provide TICS services. The trained model is suitable for TICS. Provide TICS services to support the telecommunication system. Integrate TICS services into the telecommunication system to provide users with question-and-answer services, which includes solving problems for ordinary users and providing job analysis for employees. + +# **7 Requirements of AI model generalization system for telecommunication intelligent customer service** + +## **7.1 Requirements for multimedia data processing** + +### **7.1.1 Data collection** + +In addition to fulfilling the requirements specified in [ITU-T F.748.43], the requirements for data collection are as follows: + +- It is required that the data is collected from a telecommunication system to form the telecommunication dataset, including network operation data, business operation data. +- It is required that the data is collected from different fields and topics to form the general dataset, including text content from Internet, books, academic materials, social media and encyclopaedias. +- It is required that the collected data be multimedia data, including a combination of text, image, video, audio, numeric, sound, animation, graphical and categorical data. + +### **7.1.2 Data processing** + +In addition to fulfilling the requirements specified in [ITU-T F.748.43], the requirements for data processing are as follows: + +- It is required to clean the erroneous and inconsistent data from the telecommunication system. +- It is required to realize data fusion to intelligently synthesize telecommunication data. +- It is required to mix the telecommunication datasets and general datasets to support pre-training service. +- It is required to label data to form a customer service question-and-answer dataset to support the fine-tuning service. + +## **7.2 Requirements for model generation** + +### **7.2.1 Model pre-training** + +In addition to fulfilling the requirements specified in [ITU-T F.748.43], the requirements for model pre-training are as follows: + +- It is required to use data from the telecommunication customer service domain for pre-training. +- It is required to perform model pre-training after completing data processing. + +- It is recommended to use general datasets for pre-training, encompassing those sourced from the Internet, books, academic materials, social media, encyclopaedias and other textual content. +- It is recommended that computing resources can support distributed model training. +- It is recommended to continue to improve training efficiency. +- It is required to select the model architecture according to the task requirements. Different model architectures are used for generic task, comprehension task and multimodal task. + +### 7.2.2 Model fine-tune + +In addition to fulfilling the requirements specified in [ITU-T F.748.43], the requirements for model fine-tune are as follows: + +- It is required to annotate question-and-answer data pairs for telecommunication customer service scenarios. +- It is recommended to support a variety of data, including multimodal data and high-frequency question-related data. +- It is recommended that the fine-tuning methods be selected based on customer service scenarios, the volume of data, the computing power of computing resources and the types of tasks. + +## 7.3 Requirements for model verification + +The MGS for TICS is recommended to undergo performance evaluation, adaptability verification and index evaluation to ensure operational efficacy and robustness. + +The following key metrics are recommended to be encompassed: + +- Task completion rate: The success rate that the generated models resolve user queries. +- Response latency: Ensures the end-to-end delay remains within thresholds (with different applications). +- Intent recognition accuracy: Evaluates the precision of natural language understanding capability of the generated models. +- Multimodal capability: Verify the system's ability to process and integrate multimodal data and evaluate the performance of generated models in handling cross-modal tasks. +- Domain adaptability: Assesses generalization across telecommunication scenarios. +- Composite indices: Completes performance monitoring to evaluate composite indices, including cost efficiency index, service level agreement (SLA) compliance index and service quality index. + +## 7.4 Requirements for task processing module + +It is recommended that the task processing module includes model delivery, task execution, result feedback and data feedback, which fulfil the requirements specified in [ITU-T F.748.43]. + +## 7.5 Applicable system security + +Security threats and requirements in [ITU-T X.1771] are applicable for data protection and data collection in MGS for TICS. + +Relevant security requirements of [ITU-T X.1470] are applicable, including access control, authentication, data confidentiality, data retention policy, network security, data integrity, availability and privacy. + +## 8 Functional architecture of AI model generalization system for telecommunication intelligent customer service + +Figure 8-1 illustrates the functional architecture of MGS for TICS. + +![Figure 8-1: System functional architecture diagram. The diagram shows the architecture of the AI model generalization system (MGS) for telecommunication intelligent customer service (TICS). The top level is 'Telecommunication intelligent customer service', which contains 'Intelligent customer service'. Below this is the 'AI model generalization system', which is divided into four main modules: 'Multimedia data processing module', 'Model generation module', 'Task processing module', and 'Model verification module'. The 'Multimedia data processing module' includes 'Data collection' (Telecommunication data, General data), 'Data cleaning', 'Data annotation', and 'Data fusion'. The 'Model generation module' includes 'Pre-training service' and 'Fine tune service'. The 'Task processing module' is connected to the 'Model generation module'. The 'Model verification module' includes 'Performance evaluation', 'Adaptability verification', 'Index evaluation', 'Model modification', and 'Virtual task environment'. Arrows indicate the flow of data and control: I (Data fusion to Pre-training service), II (Fine tune service to Model verification module), III (Task processing module to Fine tune service), and IV (Intelligent customer service to AI model generalization system).](042733dc5e8e7f5f30b60adba3266cde_img.jpg) + +The diagram illustrates the functional architecture of the AI model generalization system (MGS) for telecommunication intelligent customer service (TICS). The system is structured as follows: + +- Telecommunication intelligent customer service** (Top level) + - Intelligent customer service** +- AI model generalization system** (Main system) + - Multimedia data processing module**: + - Data collection (Telecommunication data, General data) + - Data cleaning + - Data annotation + - Data fusion + - Model generation module**: + - Pre-training service + - Fine tune service + - Task processing module** + - Model verification module**: + - Performance evaluation + - Adaptability verification + - Index evaluation + - Model modification + - Virtual task environment + +Interactions are indicated by arrows: + +- I**: Data fusion to Pre-training service +- II**: Fine tune service to Model verification module +- III**: Task processing module to Fine tune service +- IV**: Intelligent customer service to AI model generalization system + +F.748.71(25) + +Figure 8-1: System functional architecture diagram. The diagram shows the architecture of the AI model generalization system (MGS) for telecommunication intelligent customer service (TICS). The top level is 'Telecommunication intelligent customer service', which contains 'Intelligent customer service'. Below this is the 'AI model generalization system', which is divided into four main modules: 'Multimedia data processing module', 'Model generation module', 'Task processing module', and 'Model verification module'. The 'Multimedia data processing module' includes 'Data collection' (Telecommunication data, General data), 'Data cleaning', 'Data annotation', and 'Data fusion'. The 'Model generation module' includes 'Pre-training service' and 'Fine tune service'. The 'Task processing module' is connected to the 'Model generation module'. The 'Model verification module' includes 'Performance evaluation', 'Adaptability verification', 'Index evaluation', 'Model modification', and 'Virtual task environment'. Arrows indicate the flow of data and control: I (Data fusion to Pre-training service), II (Fine tune service to Model verification module), III (Task processing module to Fine tune service), and IV (Intelligent customer service to AI model generalization system). + +Figure 8-1 – System functional architecture + +There are two main modules: MGS and ICS. MGS mainly includes multimedia data processing module (MDPM), model generation module (MGM), task processing module (TPM) and model verification module (MVM). MDP sends the processed data to MGM. MGM uses multimedia data for pre-training and fine-tuning. The trained model is deployed in TPM. MVM receives the processing results sent by TPM and evaluates the model, which can be fed back to MGM for model optimization. ICS in TICS leverages AI models generated from MGS to interact with telecommunication users. + +## 8.1 Functions of the multimedia data processing module + +The multimedia data processing module is responsible for data collection, data cleaning, data annotation and data fusion. + +- Data collection: Collect the general data and telecommunication data from different professional scenes of the telecommunication system. +- Data cleaning: Identify, correct or remove inaccurate, incomplete, irrelevant or duplicated data from a dataset to enhance its quality and reliability. +- Data annotation: Annotate raw multimedia data for model training. +- Data fusion: Associate, integrate and analyse the data collected from different data sources to obtain more accurate and useful information. + +## 8.2 Functions of the model generation module + +The model generation module provides pre-training service and fine-tuning service. It receives the required partially heterogeneous data from the MDP and constructs a model through pre-training and fine-tuning. + +- Pre-training service: Train the model based on general telecommunication data, including work order text data, voice data and image data. Pre-training requires high computing power resources and large-scale data to ensure that the model adapts to the entire TICS scenario. It receives massive amounts of telecommunication and general data without annotation from reference point I. + +NOTE – Reference point I is the reference point between MDPM and MGM (see Figure 8-1). + +- Fine tune service: Fine-tune the large model according to the customer service data of communication scenarios and adopt fine-tuning technologies to ensure that the model can adapt to the accuracy requirements of the application and the limited computing resources. It receives annotated task data from reference point I. + +## 8.3 Functions of model verification module + +MGM transmits the models to MVM through reference point II. MVM evaluates the model to verify whether the model can truly adapt to the actual application scenarios of telecommunication customer service. + +NOTE – Reference point II is the reference point between MGM and MVM (see Figure 8-1). Models are trained by MGM and then delivered to MVM. Then in MVM, the model is deployed in virtual task environment, and complete model verification. + +- Performance evaluation: Evaluate the performance of the model, including inference speed, accuracy and resource consumption of the model. +- Adaptability verification: Verify the generalization ability, robustness of the model and evaluate key indicators. +- Model modification: Determine whether the model needs to be modified and how to modify it based on the results of performance evaluation, adaptability verification and index evaluation. +- Virtual task environment: Provide an environment for model verification. + +## 8.4 Functions of the task processing module + +The task processing module deploys models. TPM interacts with TICS to obtain the task, and the model processes the task. The data collected from the task processing procedure will go back to MGM through reference point III. + +NOTE – Reference point III is the reference point between MGM and TPM (see Figure 8-1). The models from MGM are transmitted to TPM. + +## 8.5 Intelligent customer service + +Integrate models generated from MGS through reference point IV and provide ICS. + +NOTE – Reference point IV is the reference point between MGS and ICS (see Figure 8-1). + +# Appendix I + +## Use cases of AI model generalization system in telecommunication intelligent customer service + +(This appendix does not form an integral part of this Recommendation.) + +### I.1 Use case of AI model generation of telecommunication intelligent customer service for network operation and maintenance + +This use case describes the process of model generation of TICS for network operation and maintenance (O&M). The O&M-related customer services are mainly used to assist telecommunication employees to complete the strategy design, to maintain the stable operation of the network. The O&M-related customer services receive operation and maintenance requests (voice, text, image or video) from telecommunication employees and returns the corresponding recommended solutions. + +![Diagram illustrating the model generalization process for intelligent network O&M customer service. The process is divided into 'Model generation' and 'Model utilization' phases. In the 'Model generation' phase, O&M data (Alarm cases, O&M cases, Configuration specification, etc.) and Telecom network data are used to train a 'Basic Telecom customer service model' through 'Pre-training service' and 'Fine tune service' modules. In the 'Model utilization' phase, the model is deployed into various customer services (Alarm analysis, O&M, Configuration inspection, etc.) via 'Input/output' modules, which are accessed by users.](a26e142d3df5bef41a84a9dd099d7825_img.jpg) + +The diagram illustrates the workflow for model generalization in telecommunication intelligent customer service, divided into two main phases: **Model generation** and **Model utilization**. + +**Model generation:** This phase involves the creation of the **Basic Telecom customer service model**. It starts with **O&M data** (Alarm cases, O&M cases, Configuration specification, etc.) and **Telecom network data**. The O&M data is processed through **Pre-training service** and **Fine tune service** modules to generate the basic model. + +**Model utilization:** This phase shows the deployment of the model into various customer services. The **Basic Telecom customer service model** is connected to **Input/output** modules for different services: **Alarm analysis customer service**, **O&M customer service**, **Configuration inspection customer service**, and others. Each service has its own **Input/output** module, which is accessed by users (represented by icons of people at computers). + +The diagram is labeled with **F.748.71(25)** in the bottom right corner. + +Diagram illustrating the model generalization process for intelligent network O&M customer service. The process is divided into 'Model generation' and 'Model utilization' phases. In the 'Model generation' phase, O&M data (Alarm cases, O&M cases, Configuration specification, etc.) and Telecom network data are used to train a 'Basic Telecom customer service model' through 'Pre-training service' and 'Fine tune service' modules. In the 'Model utilization' phase, the model is deployed into various customer services (Alarm analysis, O&M, Configuration inspection, etc.) via 'Input/output' modules, which are accessed by users. + +Figure I.1 – Example of model generalization for intelligent network O&M customer service + +The description of the workflow of O&M-related customer services model generation is as follows: + +- 1) The basic telecommunication customer service model has been created. Pre-training basic telecommunication customer service model with general knowledge based on extensive telecommunication network data. +- 2) Collect and clean O&M data. Collate service data for different customer requirements. +- 3) Fine-tuning basic telecommunication customer service model based on business data. Based on specific requirements, the fine tune service module can output a specific customer service model, e.g., model for alarm analysis customer service. +- 4) Create input and output module. Users can call the specific customer service through the input/output module. + +### I.2 Use case of AI model generation of telecommunication intelligent customer service for fault handling + +The MGS in TICS can construct a fault detection model to provide fault processing capability to customers, including the fault analysis model, the fault prediction model and the processing strategy recommendation model. + +- 1) The system provides users with a proactive warning function and strategy recommendation function according to the current situation of the scene; +- 2) Users proactively report the fault information to TICS, which provides a fault location function and a strategy recommendation function. + +The data collection and service module receives a large amount of on-site data. MDPM processes and stores the data and provides this data to the model. The system pre-trains and generates a basic model based on the partially heterogeneous data. The basic model obtains annotated data business from MDPM to fine-tune, and constructs the fault analysis model, the fault prediction model and the processing strategy recommendation model. These models obtain real-time partially heterogeneous data from MDPM for analysis and processing. After completing fault handling, MVM obtains the result of fault handling and evaluates the model performance to ensure that the model's capabilities can meet user needs. + +![Diagram of AI model generation for intelligent fault handling customer service. The diagram illustrates a workflow starting from 'On-site' data entering a 'Data processing' block containing 'Data collection and service module' and 'Multimodal data processing module'. This feeds into a 'Model generalization' block with 'Fine tune service' and 'Pre-training service'. These services interact with three models: 'Fault analysis model', 'Fault prediction model', and 'Strategy recommendation model'. The output of these models goes to 'Verify processing results' containing 'Model verification module', which then interacts with 'Users'. A feedback loop (dashed line) connects the verification module back to the pre-training service.](724c7777b608e53be38b12b6fb3c43bc_img.jpg) + +``` + +graph TD + OnSite([On-site]) --> DP + subgraph DP [Data processing] + DCSM[Data collection and service module] + MDPM[Multimodal data processing module] + end + DP --> MG + subgraph MG [Model generalization] + FTS[Fine tune service] + PTS[Pre-training service] + end + MG --> FAM[Fault analysis model] + MG --> FPM[Fault prediction model] + MG --> SRM[Strategy recommendation model] + FAM --> VPR + FPM --> VPR + SRM --> VPR + subgraph VPR [Verify processing results] + MVM[Model verification module] + end + VPR <--> Users((Users)) + VPR -. Feedback .-> PTS + +``` + +F.748.71(25) + +Diagram of AI model generation for intelligent fault handling customer service. The diagram illustrates a workflow starting from 'On-site' data entering a 'Data processing' block containing 'Data collection and service module' and 'Multimodal data processing module'. This feeds into a 'Model generalization' block with 'Fine tune service' and 'Pre-training service'. These services interact with three models: 'Fault analysis model', 'Fault prediction model', and 'Strategy recommendation model'. The output of these models goes to 'Verify processing results' containing 'Model verification module', which then interacts with 'Users'. A feedback loop (dashed line) connects the verification module back to the pre-training service. + +**Figure I.2 – Example of AI model generation for intelligent fault handling customer service** + +- 1) The fault analysis model: The system fine-tunes the basic model based on data such as faults, alarms and network topology, and generates the fault analysis model. The model can filter invalid alarms and redundant alarms, explore the relationship between faults and alarms, construct fault topology relationships and quickly determine the location of alarms. +- 2) The fault prediction model: The system fine-tunes the basic model based on data such as work orders, faults and topology relationships, and generates the fault prediction model. The model can analyse the real-time operation status of the network and provide fault information prediction. +- 3) The processing strategy recommendation model: The system fine-tunes the basic model based on data such as expert experience and historical cases and generates the processing strategy recommendation model. The model can provide a fault-handling strategy for users. + +# Bibliography + +- [b-ITU-T F.746.16] Recommendation ITU-T F.746.16 (2022), *Technical requirements and evaluation methods of intelligence levels of intelligent customer service systems.* +- [b-ITU-T F.748.25] Recommendation ITU-T F.748.25 (2023), *Requirements for speech interaction of intelligent customer services.* +- [b-ISO/IEC 2382] ISO/IEC 2382:2015, *Information technology – Vocabulary.* + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services 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telecommunication services + +Multimedia services + +--- + +**Assessment criteria for foundation models – +General** + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +# ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## Recommendation ITU-T F.748.77 + +## Assessment criteria for foundation models – General + +## Summary + +A foundation model is any model that is trained on broad data that can be adapted to a wide range of downstream tasks. To make the capabilities and related performance measurable and evaluable, assessment criteria need to be specified. + +Recommendation ITU-T F.748.77 specifies the overall workflow of assessment and describes the framework for assessment for foundation models with specific domains along with the assessment dimensions. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.748.77 | 2025-12-14 | 21 | 11.1002/1000/16596 | + +## Keywords + +Assessment, assessment dimensions, assessment framework, assessment methods, foundation model. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2026 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|---------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 2 | +| 6 Overview..... | 2 | +| 7 General framework of foundation model assessment..... | 2 | +| 8 Overall workflow of foundation models assessment..... | 3 | +| 9 Foundation model assessment factors ..... | 4 | +| 9.1 Construction methods of assessment samples ..... | 4 | +| 9.2 Assessment indicators ..... | 5 | +| 9.3 Assessment dataset ..... | 6 | +| 9.4 Assessment tool ..... | 7 | +| 10 Assessment dimensions ..... | 7 | +| 10.1 Functionality..... | 7 | +| 10.2 Accuracy ..... | 7 | +| 10.3 Reliability ..... | 7 | +| 10.4 Security..... | 8 | +| 10.5 Interactivity..... | 8 | +| 10.6 Applicability ..... | 8 | +| Bibliography..... | 9 | + + + +# Recommendation ITU-T F.748.77 + +## Assessment criteria for foundation models – General + +## 1 Scope + +This Recommendation mainly focuses on the general framework, overall workflow, factors and dimensions of assessment criteria for foundation models. + +The scope of this Recommendation includes: + +- Overview; +- General framework of foundation model assessment; +- Overall workflow of foundation model assessment; +- Foundation model assessment factors; +- Assessment dimensions. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T F.748.44] Recommendation ITU-T F.748.44 (2025), *Assessment criteria for foundation models – Benchmark*. + +[ISO/IEC 23894] ISO/IEC 23894:2023, *Information technology — Artificial intelligence — Guidance on risk management*. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following term defined elsewhere: + +**3.1.1 artificial intelligence** [b-ITU-T F.749.13]: An interdisciplinary field, usually regarded as a branch of computer science, dealing with models and systems for the performance of functions generally associated with human intelligence, such as reasoning and learning. + +### 3.2 Terms defined in this Recommendation + +None. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|---------------------------------| +| AI | Artificial Intelligence | +| BLEU | Bilingual Evaluation Understudy | +| EM | Exact Match | +| FID | Fréchet Inception Distance | + +## 5 Conventions + +In this Recommendation: + +The keywords "is suggested to" indicate a suggestion which is suggested but which is not absolutely required or recommended. Thus, this suggestion need not be present to claim conformance. + +The keyword "should" indicates that among several possibilities one is recommended as particularly suitable, without mentioning or excluding others; or that a certain course of action is preferred but not necessarily required (should equals is recommended that). + +The keyword "can" is used for statements of possibility and capability, whether material, physical, or causal (can equals is able to). + +## 6 Overview + +As the general paradigm of artificial intelligence (AI), foundation models are enabled by transfer learning and scale, i.e., transfer learning makes foundation models possible, and scale makes foundation models powerful. In line with technological advances, foundation models have evolved with the development of hardware, data capacities and computing resources. As demanded by the market, a series of foundation model products have been launched these past few years. Foundation models acquire capabilities that surprisingly emerge from their learning process and later enhance downstream applications. Specifically, linguistic and visual capabilities together with the ability to affect the physical world, perform reasoning and searches, and interact with humans. The capabilities of foundation models indicate that they have the potential to transform various sectors and industries by extending the role that AI plays in society. Foundation models have also led to surprising outcomes related to scale. Multi-modal foundation models are a natural way of blending all the relevant information about a domain and adapting to tasks that also span multiple modes. + +Foundation models are one of the bases for the evolution and revolution of AI capacities, AI applications and AI models. To achieve a healthy development of AI technologies and applications, it is necessary to study and specify objective assessment criteria, measurements and evaluation. + +## 7 General framework of foundation model assessment + +For the assessment of foundation model(s), the interface between assessment and user(s) is the "assessment platform" based on the theoretical support from the constructions of data, indicators and assessment initiation. The assessment platform provides technical support(s) to the constructions which include data constructions, indicator construction, assessment initiation, etc. The specific assessment criteria and assessment details are suggested to be dependent on the specific scenarios, applications, parameters, requirements/demands, etc. The assessment can be automatic or manual. This Recommendation specifies and describes the general requirements and descriptions for the assessment of foundation model(s). + +Figure 1 illustrates a general framework of foundation model assessment. + +![Figure 1: General framework of foundation models assessment. The diagram is divided into three horizontal sections: Assessment scenarios, Assessment factors, and Assessment dimensions. Assessment scenarios include Basic tasks (Text classification, Sentiment classification, Image classification, Speech recognition, Speech synthesis, Target detection, Image segmentation, Face recognition) and Application tasks (Essay writing, Q&A, Image creation, Recommendation, Customer service, Code generation, Audio creation, Consulting). Assessment factors include Methods, Indicators, Data, and Tools. Assessment dimensions include Functionality (Task richness, Completeness), Accuracy (Precision, Recall, Explainability), Reliability (Anti-noise, Anti-attack, Universality, Uncertainty), Security (Text compliance, Prejudice, Privacy), Interactivity (Latency, Smoothness, Grammar, Continuous), and Applicability (Stability, Scalability, Energy efficiency, Compatibility).](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +**Assessment scenarios** + +| Basic tasks | | Application tasks | | +|--------------------------|--------------------|-------------------|------------------| +| Text classification | Speech synthesis | Essay writing | Customer service | +| Sentiment classification | Target detection | Q&A | Code generation | +| Image classification | Image segmentation | Image creation | Audio creation | +| Speech recognition | Face recognition | Recommendation | Consulting | + +**Assessment factors** + +| Methods | Indicators | Data | Tools | +|---------|------------|------|-------| +|---------|------------|------|-------| + +**Assessment dimensions** + +| Functionality | Accuracy | Reliability | Security | Interactivity | Applicability | +|---------------|----------------|--------------|-----------------|---------------|-------------------| +| Task richness | Precision | Anti-noise | Text compliance | Latency | Stability | +| Completeness | Recall | Anti-attack | Prejudice | Smoothness | Scalability | +| | Explainability | Universality | Privacy | Grammar | Energy efficiency | +| | | Uncertainty | | Continuous | Compatibility | + +F.748.77(25) + +Figure 1: General framework of foundation models assessment. The diagram is divided into three horizontal sections: Assessment scenarios, Assessment factors, and Assessment dimensions. Assessment scenarios include Basic tasks (Text classification, Sentiment classification, Image classification, Speech recognition, Speech synthesis, Target detection, Image segmentation, Face recognition) and Application tasks (Essay writing, Q&A, Image creation, Recommendation, Customer service, Code generation, Audio creation, Consulting). Assessment factors include Methods, Indicators, Data, and Tools. Assessment dimensions include Functionality (Task richness, Completeness), Accuracy (Precision, Recall, Explainability), Reliability (Anti-noise, Anti-attack, Universality, Uncertainty), Security (Text compliance, Prejudice, Privacy), Interactivity (Latency, Smoothness, Grammar, Continuous), and Applicability (Stability, Scalability, Energy efficiency, Compatibility). + +**Figure 1 – General framework of foundation models assessment** + +The configurations of the specific assessment are suggested to be set depending on the related assessment scenario. The assessment factors are suggested to be considered including the methods, indicators, data and tools. During the assessment, the assessment dimensions and assessment metrics are suggested to be well defined/set according to practical scenarios and use cases. + +## 8 Overall workflow of foundation models assessment + +Figure 2 illustrates the overall workflow for the assessment of foundation model(s). At the beginning of the assessment, the relevant requirement(s) should be analysed. It is suggested that the platform environment for assessment be configured according to the requirements. It is also suggested that at the same time the dataset be constructed to meet the specific requirement(s) before assessment initiation. Once the assessment is conducted, the results should be systematically recorded and analysed to evaluate model performance and identify directions for further optimization. Assessment results may be publicly disclosed in accordance with applicable policies or agreements. Based on the assessment outcomes and stakeholder feedback, the original assessment requirements should be reviewed and updated to support continuous improvement in subsequent assessment cycles. + +![Flowchart of the overall workflow for assessment. The steps are: Assessment requirement analysis, Assessment environment preparation, Assessment data construction, Assessment initiation, Assessment/Evaluation/Measurement results analysis, Assessment announcement (dashed box), and Assessment feedback and requirement update. A feedback loop connects the final step back to the first step. The code F.748.77(25) is shown at the bottom right.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +``` + +graph LR + A[Assessment requirement analysis] --> B[Assessment environment preparation] + B --> C[Assessment data construction] + C --> D[Assessment initiation] + D --> E[Assessment/Evaluation/Measurement results analysis] + E --> F[Assessment announcement] + F --> G[Assessment feedback and requirement update] + G --> A + style F stroke-dasharray: 5 5 + +``` + +F.748.77(25) + +Flowchart of the overall workflow for assessment. The steps are: Assessment requirement analysis, Assessment environment preparation, Assessment data construction, Assessment initiation, Assessment/Evaluation/Measurement results analysis, Assessment announcement (dashed box), and Assessment feedback and requirement update. A feedback loop connects the final step back to the first step. The code F.748.77(25) is shown at the bottom right. + +**Figure 2 – The overall workflow for assessment** + +The overall workflow for assessment is described as follows: + +- **Assessment requirement analysis:** Before the initiation of foundation model assessment, relevant requirements should be analysed either automatically or manually. The requirement(s) are suggested to cover aspects such as software, hardware, dataset and other related resources. +- **Assessment environment preparation:** During the practical assessment, the assessment process is suggested to be configured in a mirrored or simulated environment. The environment configuration can be flexible, depending on the scale and complexity of the foundation model and datasets involved. +- **Assessment data construction:** The assessment dataset should be regularly supplemented or updated through manual annotation, automatic sample selection, or algorithmic data generation. In addition, representative benchmark suites can also be employed to support comparative evaluation. Examples of sets of benchmarks are provided by [ITU-T F.748.44]. +- **Assessment initiation:** the assessment process can be initiated once the environment is prepared, the dataset is in place, and the specific requirement(s) and demand(s) have been addressed in accordance with the defined assessment plan. +- **Assessment results analysis:** Assessment results should be systematically recorded and analysed. These results serve as the basis for understanding model performance and making further optimization decisions. +- **Assessment announcement:** The assessment result(s) can be publicly disclosed, if necessary. Before the announcement, privacy considerations and any relevant legal or ethical issues should be reviewed and addressed. +- **Assessment feedback and requirements update:** Based on the assessment results and stakeholder feedback, the initial requirements should be reviewed and updated to guide future assessment activities and ensure ongoing improvement. + +## 9 Foundation model assessment factors + +### 9.1 Construction methods of assessment samples + +In the construction of assessment samples, comprehensive considerations are suggested to be given to evaluation methods such as "zero shot", "one shot", "few shot" and prompt engineering. For the evaluation results, objective or subjective assessments depend on specific needs and requirements. + +Current research indicates that as the size of model parameters increases, although foundation models exhibit higher performance in zero sample tasks, their accuracy is significantly better in single sample or few sample scenarios than in zero sample tasks. On the other hand, through research on prompt engineering, researchers have found that foundation models also exhibit significant performance differences with different prompt words. Therefore, in terms of evaluation methods, questioning + +methods such as zero sample, single sample, few sample and different prompt words have been considered, aiming to comprehensively cover various scenarios that users may encounter in actual use, in order to comprehensively assess/evaluate the performance of the model. + +- **Zero shot (zero samples):** in "zero shot" assessment, the model needs to directly solve the task without encountering samples related to the target task. This type of testing mainly relies on the knowledge acquired by the model in the pre-training stage, using the learned knowledge and understanding reasoning ability to infer and solve new tasks. +- **One shot (single sample):** in "single shot" assessment, the model only contacts with one sample which is relevant to the target task. The model needs to learn the rules of the task based on this sample and apply these rules to similar problems that have not been seen before. This type of testing places higher demands on the model's generalization ability. +- **Few shot (few samples):** in "few shot" assessment, the model is exposed to a limited number of samples related to the target task. Usually, these sample sizes are very small, such as a few to near a hundred. The model needs to quickly learn the rules of the task on these limited samples and apply these rules to new problems during testing. This type of test aims to evaluate the learning ability of the model in situations where data is scarce. + +During the judgement of assessment results, for evaluation indicators with standard answers, such as accuracy, recall, F1 score, exact match (EM), bilingual evaluation understudy (BLEU), etc., the method of directly calculating specific values based on statistical evaluation indicators or evaluation models is used for objective evaluation. + +For assessment indicators without fixed standard answers, such as the acceptability of text generation, machine translation, content creation, interactivity, subjective evaluation methods are used for evaluation. Subjective evaluation is supposed to establish a panel of domain experts to independently evaluate the test results based on scoring criteria. + +### 9.2 Assessment indicators + +In the assessment, the indicators can be classified into objective and subjective. Objective indicators are mainly used to evaluate question types with standard or relatively standard answers and cover efficiency related indicators. This type of assessment indicators mainly relies on clear and explicit standards, so its results have a high degree of quantifiability and comparability. For open-ended questions, subjective indicators are mainly used, which do not have fixed or correct answers, so their assessment requires more flexible and personalized methods. Although the application of subjective indicators may lead to a decrease in comparability of results, it can provide a more comprehensive and in-depth assessment of the effectiveness and superiority of answers. + +- **Objective indicators** + +In the process of assessing/evaluating the performance of foundation models, the output results can be compared through data comparison and algorithm calculation, using objective indicators such as classification accuracy and F1 score to evaluate the differences in performance between different models. This can minimize the impact of human factors on the test results as much as possible, achieving fairness and impartiality in the evaluation results. + +The accuracy indicators for performance assessment of large models can usually be divided into classification task indicators and generation task indicators according to the nature of the task. Common classification task metrics include accuracy, recall, precision, F1 score, and confusion matrix, which are mainly used in tasks such as named entity recognition, image recognition and speech emotion classification. These tasks require the model to judge the category of input data, for example, text-based judgment of the emotional type expressed by a paragraph of text. Image modelling determines entities and relationships in images. Speech models recognize emotional or speaker identity information in speech. The task indicators are mainly applied to tasks such as text generation, image generation and speech synthesis. These tasks require the model to generate new + +data that meets the requirements based on the input content, for example, a text model generates a logically coherent piece of content. Image models generate images containing multiple elements. The speech model generates human language speech based on text. Common metrics for generating tasks include BLEU, ROUGE, and METEOR for evaluating text, inception score and FID for evaluating images, and speech quality and naturalness for evaluating synthesized audio. + +Stability and efficiency are also important indicators for measuring model capabilities, such as the number of invalid responses, inference latency and system power consumption. The stability index mainly focuses on the performance of the model when the input content includes noise, adversarial samples, etc. When evaluating stability, the number of invalid responses given by the model during the continuous response process, as well as indicators such as task completion rate, can be counted. These indicators reflect the robustness of the model in the face of input disturbances. Efficiency indicators focus on the latency and energy consumption of the model during training and inference processes. The latency index mainly calculates the time required for the model to understand the input content and generate output answers. This index can effectively evaluate the applicability of the model in real-time tasks. The energy consumption index is used to measure the power consumption requirements of the model during use, and this index is of great significance in evaluating the model's demand for hardware resources and energy consumption. + +#### - **Subjective indicators** + +For question types without fixed and standard results/answers, subjective scoring methods are usually used for the related assessment. Subjective indicators involve the evaluation of answers in multiple dimensions such as innovation, feasibility and applicability, which requires evaluators to have rich professional knowledge and experience. Therefore, it is necessary to first establish a review panel composed of domain experts. These review experts need to have a deep knowledge background and extensive practical experience in the relevant field in order to accurately evaluate the quality of the model's answers. + +In the assessment process, the expert group needs to discuss and achieve a consensus on the scoring criteria to rate the type of answers. These scoring criteria include, but are not limited to, key aspects such as accuracy, completeness, logic and comprehensibility of answers. To ensure the consistency and reliability of the evaluation results, clear standards and score ranges need to be set for each rating level. Then, multiple experts will independently rate the answers to each question. + +Finally, it is necessary to summarize and analyse the ratings of each expert to calculate the scores of the model on various indicators. In this process, various statistical methods and techniques can be used, such as internal consistency testing and reliability analysis, to improve the stability and reliability of the evaluation results. + +### 9.3 Assessment dataset + +The assessment dataset is suggested to meet requirements for content diversity, security and traceability. + +#### - **Content diversity** + +To ensure robust performance across a wide range of tasks, the assessment dataset is suggested to be collected from diverse sources, covering various languages and modalities. The dataset is suggested to reflect a broad representation of knowledge domains, user demographics and cultural perspectives. Over-reliance on a single data source or a limited number of homogeneous sources are suggested to be avoided. + +#### - **Traceability** + +The origin of assessment datasets is suggested to be traceable. For open-source evaluation datasets, the corresponding licences are suggested to retained. For self-collected evaluation datasets, detailed collection records are suggested to be maintained. + +### 9.4 Assessment tool + +The assessment tools used in the evaluation of foundation models are suggested to meet the following requirements to ensure reliability, transparency, compatibility and fairness of evaluation results: + +#### - **Reliability** + +Assessment tools are suggested to provide consistent outputs when applied under identical evaluation conditions. The evaluation process and output are suggested to be reproducible across different runs and computing environments. + +#### - **Transparency** + +Assessment tools, including their evaluation logic, metrics and benchmarks, are suggested to be well-documented. The documentation is suggested to include definitions of indicators, scoring rules and test input/output formats. + +#### - **Compatibility** + +Assessment tools are suggested to be adaptable to different types of foundation models (e.g., language models, multi-modal models) and task formats. + +#### - **Fairness** + +Assessment tools are suggested to avoid introducing bias in favour or against specific models, frameworks or training strategies. Any domain-specific assumptions or limitations are suggested to be disclosed. + +## 10 Assessment dimensions + +Considering the outstanding universality of foundation models in various task domains, existing testing benchmarks and assessment metrics designed specifically for a single task are no longer sufficient to comprehensively and objectively evaluate their performance. To achieve a comprehensive evaluation of these complex models and ensure coverage of various task types and application scenarios, the system divides the evaluation indicators into multiple dimensions, and strives to cover the actual usage scenarios of users. + +### 10.1 Functionality + +This dimension mainly focuses on the capabilities of large models to solve multiple tasks. The types of tasks involved include benchmark tasks in various fields, vertical industry application tasks and complex tasks across multiple domains and modalities. When evaluating functionality, task richness and support completeness are the two most important aspects. Task richness reflects the types of tasks that the model can cover, while support completeness refers to the completion and complexity of the model in handling various types of tasks. + +### 10.2 Accuracy + +This dimension mainly focuses on the accuracy of foundation models in executing various tasks. There may be differences in the indicators used to measure accuracy for different types of tasks. In addition to tasks with clear objective assessment methods, some indicators of generative tasks, such as text generation, image generation, speech synthesis, etc., should be evaluated based on objective indicators and combined with subjective assessment indicators. + +### 10.3 Reliability + +This dimension mainly focuses on the resistance of foundation models to input noise, as well as the stability of multiple output results for the same problem. The main focus is on examining the model's tolerance for input noise, resistance to adversarial samples, applicability in different datasets and tasks, as well as the uncertainty of the model's answer content when asked multiple times. In this + +dimension of evaluation, in addition to focusing on perturbations based on grammar or semantics, pixel or image features, sound quality or speech, potential impacts from dataset distribution and data sources should also be considered. + +### **10.4 Security** + +Adversarial testing and red-teaming methods are recommended. [ISO/IEC 23894] provides guidance on how organizations can manage risks related to AI, which is also applicable to addressing security concerns of foundation models. + +### **10.5 Interactivity** + +This dimension mainly focuses on the ability of foundation models to interact with users to evaluate the friendliness of model products. When evaluating interactivity, attention should be paid to aspects such as inference latency, dialogue coherence, content richness, fluency of expression, grammatical norms, external interaction ability and tool application ability. In the evaluation process of this dimension, it is difficult to accurately measure some indicators that help identify whether the generated content of the model conforms to human values and needs through automatic evaluation methods. Therefore, manual evaluation is still considered a more direct and effective evaluation method. + +### **10.6 Applicability** + +This dimension focuses on exploring the deployment, operation and business support capabilities of foundation model products or systems in real-world application scenarios, aiming to comprehensively examine the practicality and effectiveness of products based on large models in various aspects. When evaluating this dimension, attention should be paid to multiple areas including system stability, scalability, inference energy efficiency, system compatibility and personalized development capabilities. However, most of the evaluation indicators in this dimension are difficult to measure through automated objective indicators, and often require the use of subjective evaluations, interviews, surveys and other methods for investigation. Therefore, in the evaluation process of this dimension, how to establish a reasonable evaluation index system has become the most severe challenge. + +## Bibliography + +- [b-ITU-T F.749.13] Recommendation ITU-T F.749.13 (2021), *Framework and requirements for civilian unmanned aerial vehicle flight control using artificial intelligence.* + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.748.78-202512-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/F/T-REC-F.748.78-202512-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d4d8969f805414689ab79cfd08c333d454d482b3 --- /dev/null +++ b/marked/F/T-REC-F.748.78-202512-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:636c3839edff955a5b6208530b05fa1c983ab153d90f00216517a7a99478b988 +size 7074 diff --git a/marked/F/T-REC-F.748.78-202512-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg b/marked/F/T-REC-F.748.78-202512-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c796af0edd40c1941f871c7e63b0c9936042c047 --- /dev/null +++ b/marked/F/T-REC-F.748.78-202512-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:be8d5d6a6ae8418998802d849e8310ea55c1126477cf0e216e7860d7477a42ab +size 130433 diff --git a/marked/F/T-REC-F.748.78-202512-I_PDF-E/raw.md b/marked/F/T-REC-F.748.78-202512-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..baf8c92df78d7c16e630b314084131e69c3133e2 --- /dev/null +++ b/marked/F/T-REC-F.748.78-202512-I_PDF-E/raw.md @@ -0,0 +1,424 @@ + + +Recommendation + +**ITU-T F.748.78 (12/2025)** + +SERIES F: Non-telephone telecommunication services + +Multimedia services + +--- + +**Requirements for foundation model training +and inference cluster system** + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with white lines representing latitude and longitude, and the letters 'ITU' in a bold, blue, sans-serif font overlaid on the globe. + +ITU logo + +# ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.748.78 + +# Requirements for foundation model training and inference cluster system + +## Summary + +The current foundation model has become an important technological path to promote the development of the multimedia industry. In the process of technological innovation and application implementation, training and inference cluster system need to meet new requirements. In practical applications, the demands placed on the cluster system vary depending on the type and scale of the models in use. Consequently, developing a comprehensive framework for system capabilities to assist stakeholders in selecting appropriate technologies has become a key focus within the industry. + +Recommendation ITU-T F.748.78 specifies the requirements for the cluster system in the context of foundation models, clarifies the capabilities required for foundation model training and inference cluster system, and promotes the construction of efficient, stable and scalable foundation model training and inference cluster system. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.748.78 | 2025-12-14 | 21 | 11.1002/1000/16597 | + +## Keywords + +Artificial intelligence, foundation model, training and inference cluster system. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2026 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-----------------------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Framework of foundation model training and inference cluster system ..... | 2 | +| 7 Components-level requirements ..... | 3 | +| 7.1 Hardware requirements ..... | 3 | +| 7.2 Software requirements..... | 4 | +| 8 Cluster-level system requirements..... | 5 | +| 8.1 Cluster system training requirements ..... | 5 | +| 8.2 Cluster system inference requirements..... | 6 | +| 9 Foundation models workload-level requirements ..... | 6 | +| 9.1 Task category..... | 6 | +| 9.2 Parameter settings..... | 7 | +| Bibliography..... | 8 | + + + +# Recommendation ITU-T F.748.78 + +## Requirements for foundation model training and inference cluster system + +## 1 Scope + +This Recommendation specifies requirements for foundation model training and inference cluster system, for which it addresses: + +- overview; +- components-level and cluster-level system requirements; +- foundation model workload-level requirements. + +This Recommendation applies to the quality evaluation of cluster system for foundation models. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 model inference** [b-ITU-T Y.3179]: Process by which a deployed machine learning model generates a result. + +NOTE – Examples of generated results from a machine learning model include prediction and classification. + +**3.1.2 deep learning** [b-ITU-T F.748.12]: A representation learning method, used to model high-level abstractions in data through the use of model architectures, which are composed of multiple nonlinear transformations. + +**3.1.3 machine learning framework** [b-ITU-T Y.3531]: A set of functionalities for provisioning machine learning data, as well as training, deployment and management of a machine learning model. + +**3.1.4 workload** [b-ITU-T F.748.11]: Workload is the benchmark test task for measuring and evaluating artificial intelligence chips, that is, the benchmark test program containing a specific AI task. + +### 3.2 Terms defined in this Recommendation + +None. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|-------------------------------| +| AI | Artificial Intelligence | +| CPU | Central Processing Unit | +| FPGA | Field Programmable Gate Array | +| GPU | Graphics Processing Unit | +| MoE | Mixture of Experts | +| RDMA | Remote Direct Memory Access | +| TPU | Tensor Processing Unit | + +## 5 Conventions + +In this Recommendation: + +- The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. +- The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement needs not be present to claim conformance. + +## 6 Framework of foundation model training and inference cluster system + +Figure 1 illustrates the Recommendation's scope of requirements for foundation model training and inference cluster system, including components-level requirements, cluster-level system requirements and foundation models workload-level requirements. The components are standardized from both hardware and software dimensions for the basic unit composition of the foundation model cluster system. Clause 8 standardizes the technical capabilities required for training and inference of the foundation model of the cluster system. In the workload-level requirements, a foundation model load task for capability evaluation is provided. + +![Figure 1 – Framework of the foundation model training and inference cluster system. The diagram shows a hierarchical structure: Multimedia applications (top, dashed box) -> Foundation models workload (Task category, Parameter settings) -> Training and inference cluster system (Cluster system training: Distributed training, Stability, Heterogeneous chip hybrid training, Resource management; Cluster system inference: Inference efficiency optimization, Stability, Resource management) -> Components (Software: Machine learning software, Cluster management software; Hardware: General computing unit, Accelerated computing unit, Storage unit, Network unit).](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +``` + +graph TD + subgraph Multimedia_applications [Multimedia applications] + subgraph Foundation_models_workload [Foundation models workload] + Task_category[Task category] + Parameter_settings[Parameter settings] + end + subgraph Training_and_inference_cluster_system [Training and inference cluster system] + subgraph Cluster_system_training [Cluster system training] + DT[Distributed training] + S1[Stability] + HCHT[Heterogeneous chip hybrid training] + RM1[Resource management] + end + subgraph Cluster_system_inference [Cluster system inference] + IEO[Inference efficiency optimization] + S2[Stability] + RM2[Resource management] + end + end + subgraph Components [Components] + subgraph Software [Software] + MLS[Machine learning software] + CMS[Cluster management software] + end + subgraph Hardware [Hardware] + GCU[General computing unit] + ACU[Accelerated computing unit] + SU[Storage unit] + NU[Network unit] + end + end + end + +``` + +Figure 1 – Framework of the foundation model training and inference cluster system. The diagram shows a hierarchical structure: Multimedia applications (top, dashed box) -> Foundation models workload (Task category, Parameter settings) -> Training and inference cluster system (Cluster system training: Distributed training, Stability, Heterogeneous chip hybrid training, Resource management; Cluster system inference: Inference efficiency optimization, Stability, Resource management) -> Components (Software: Machine learning software, Cluster management software; Hardware: General computing unit, Accelerated computing unit, Storage unit, Network unit). + +F.748.78(25) + +**Figure 1 – Framework of the foundation model training and inference cluster system** + +## 7 Components-level requirements + +### 7.1 Hardware requirements + +#### 7.1.1 General computing unit + +The general computing units form the core of artificial intelligence (AI) servers responsible for managing standard computational tasks. They provide a unified application interface and are interconnected with accelerated computing, storage and network units. The requirements are as follows: + +- The general computing unit is required to have multi-task concurrency capability and to support instruction-level/data-level parallel processing capability. +- The general computing unit is required to support virtualization/containerization, resource isolation and elastic allocation. +- The general computing unit is recommended to support at least one instruction set architecture. + +#### 7.1.2 Accelerated computing unit + +##### 7.1.2.1 Training cluster accelerated computing unit + +- The training accelerated computing unit is recommended to support at least two precision types and to provide mixed-precision training and overflow protection. +- The training accelerated computing unit is required to have software stack capabilities. +- The training accelerated computing unit is required to support scalable high-speed interconnection interface capabilities between accelerators. + +##### **7.1.2.2 Inference cluster accelerated computing unit** + +- a) The inference accelerated computing unit is recommended to support low-precision inference. +- b) The inference accelerated computing unit is recommended to provide inference optimization toolchains. + +#### **7.1.3 Storage unit** + +- a) The storage unit is required to support dynamic capacity expansion without interrupting training tasks. +- b) The storage unit is recommended to support data prefetching and caching to reduce data loading latency. + +#### **7.1.4 Network unit** + +##### **7.1.4.1 Training cluster network unit** + +- a) The training cluster network unit is required to adopt a point-to-point high-performance interconnect architecture that supports remote direct memory access (RDMA). +- b) The training cluster network unit is required to support network topology adaptation to select an appropriate network topology based on the characteristics of large model training. +- c) The storage unit is required to provide sustained storage bandwidth to enhance data loading, model training or fine-tuning processes. +- d) The storage unit is recommended to support direct communication between storage system and AI acceleration cards. + +##### **7.1.4.2 Inference cluster network unit** + +- a) The inference cluster network unit is required to adopt an expandable network structure that scales up according to inference needs. +- b) The inference cluster network unit is required to support interface bandwidth to meet requirements of large model inference and ensure the rapid transmission of data during the inference process. + +### **7.2 Software requirements** + +#### **7.2.1 Machine learning software** + +##### **7.2.1.1 Machine learning software of training** + +- a) The cluster system is required to support distributed training. +- b) The cluster system is required to support automatic optimization of distributed parallel strategies coordinating models, frameworks and computational resources. +- c) The cluster system is required to support mixed-precision training. +- d) The cluster system is recommended to support checkpoint recovery. +- e) The cluster system is required to support multi-level hardware abstraction representations. + +##### **7.2.1.2 Machine learning software of inference** + +- a) The cluster system is required to support inference acceleration services for server-side or edge-side deployments. +- b) The cluster system is recommended to support foundation model inference acceleration. +- c) The cluster system is recommended to support dynamic batch size adjustment to adapt to varying workloads. + +#### **7.2.2 Cluster management software** + +Cluster management software orchestrates resources across servers, ensuring system efficiency, stability and scalability. The functional requirements are as follows: + +- a) The cluster management software is required to provide fine-grained resource monitoring of central processing unit (CPU), graphics processing unit (GPU), memory and cache usage. +- b) The cluster management software is required to support container orchestration and networking. +- c) The cluster management software is required to support task scheduling. +- d) The cluster management software is recommended to support integration with third-party cluster management solutions. +- e) The cluster management software is required to support multi-tenant isolation to ensure tenant data security and resource fairness. +- f) The cluster management software is recommended to support automatic fault recovery to reduce manual intervention. + +## **8 Cluster-level system requirements** + +### **8.1 Cluster system training requirements** + +#### **8.1.1 Distributed training** + +- a) The cluster system is required to support data, tensor, pipeline and model parallelism to optimize training for large-scale datasets and models. +- b) The cluster system is required to support gradient synchronization optimization to reduce cross-node communication latency. +- c) The cluster system is recommended to support dynamic task scheduling to avoid straggler nodes affecting training efficiency. + +#### **8.1.2 Stability** + +- a) The cluster system is required to support the automatic saving of training checkpoints at regular intervals to avoid data loss due to unexpected interruptions. +- b) The cluster system is required to provide dedicated tools for resuming training from the last saved checkpoint. +- c) The cluster system is recommended to support error reporting and fault diagnostics functions, which contribute to efficient resolution of issues encountered during training. +- d) The cluster system is recommended to control the duration from training interruption to the recovery of training operations at the minute level. + +#### **8.1.3 Heterogeneous chip hybrid training** + +- a) The cluster system is recommended to enable training across GPU, tensor processing unit (TPU), field programmable gate array (FPGA) and other AI accelerators within the same cluster. +- b) The cluster system is recommended to support mixed-precision training to maximize computational efficiency. +- c) The cluster system is recommended to support task partitioning based on chip capabilities to optimize resource utilization. + +#### 8.1.4 Resource management + +Efficient resource management ensures that the system maximizes its computational, storage and network resources for large-scale training tasks. The functional requirements are as follows: + +- a) The cluster system is required to provide resource monitoring tools to track CPU, GPU, memory and bandwidth usage in real-time. +- b) The cluster system is required to support task scheduling. +- c) The cluster system is recommended to provide fault-tolerance mechanisms. + +### 8.2 Cluster system inference requirements + +#### 8.2.1 Inference efficiency optimization + +- a) The cluster system is required to support inference acceleration services suitable for both server-side and edge-side deployments. +- b) The cluster system is recommended to support foundation model inference acceleration technologies. +- c) The cluster system is recommended to support dynamic batch size adjustment. + +#### 8.2.2 Stability + +- a) The cluster system is required to maintain stable inference performance under different workload intensities, avoiding significant fluctuations in inference latency or throughput. +- b) The cluster system is recommended to support real-time monitoring of inference tasks of inference latency, throughput and error rates. +- c) The cluster system is required to support a fast fault recovery mechanism. + +#### 8.2.3 Resource management + +- a) The cluster system is required to provide fine-grained resource monitoring of CPU, GPU, memory, and network bandwidth, to ensure rational resource allocation. +- b) The cluster system is required to support dynamic resource adjustment based on the number and complexity of inference tasks. +- c) The cluster system is required to support multi-tenant isolation to ensure the security of tenant data and the fairness of resource allocation among different tenants during inference. + +## 9 Foundation models workload-level requirements + +Foundation models workload-level requirements address diversity and distinct resource demands of foundation models training and inference in the cluster system. Foundation models workload-level requirements establish a unified benchmark with specified tasks and parameter settings to evaluate the cluster system requirements at the component-level and cluster-level. + +### 9.1 Task category + +Foundation model workload is required to support a range of task categories to accommodate different applications. The task category requirements are as follows: + +- a) The task category is required to contain language tasks (e.g., LLama3 [b-LLama3]), multimodal tasks (e.g., stable diffusion [b-Stable-Diffusion]), and vision tasks (e.g., Qwen-2.5-VL [b-Qwen]). +- b) The task category is required to contain densely connected convolutional networks and mixture of experts (MoE) models. +- c) The task category is recommended to contain training and inference of foundation models with specific parameters. + +### **9.2 Parameter settings** + +Parameter settings define the system's capabilities for training and inference to meet workload requirements effectively. + +- a) The foundation model workload to evaluate the capabilities of the cluster system is required to provide clear requirements for parameter settings. +- b) It is recommended to consider the performance in the model inference task of the cluster with different input and output lengths of the context, so as to better serve the multimedia application scenarios. + +## Bibliography + +- [b-ITU-T F.748.11] Recommendation ITU-T F.748.11 (2020), *Metrics and evaluation methods for a deep neural network processor benchmark*. +- [b-ITU-T F.748.12] Recommendation ITU-T F.748.12 (2021), *Deep learning software framework evaluation methodology*. +- [b-ITU-T Y.3179] Recommendation ITU-T Y.3179 (2021), *Architectural framework for machine learning model serving in future networks including IMT-2020*. +- [b-ITU-T Y.3531] Recommendation ITU-T Y.3531 (2020), *Cloud computing - Functional requirements for machine learning as a service*. +- [b-LLama3] LlamaTeam. The Llama 3 Herd of Models [EB/OL]. [2024-11-23]. + +- [b-Qwen] QwenTeam. Qwen2.5-VL Technical Report [EB/OL]. [2025-2-19]. + +- [b-Stable-Diffusion] Rombach, R., Blattmann, A., Lorenz, D., et al. High-Resolution Image Synthesis with Latent Diffusion Models [EB/OL]. [2022-4-13]. + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.748.79-202512-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg b/marked/F/T-REC-F.748.79-202512-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c1629394c02f697f60ae954ad36bf274fa8082cb --- /dev/null +++ b/marked/F/T-REC-F.748.79-202512-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:3763acd7a0ed56aa30f3f90468c1fb0cb54573eb9045bca3eddf8976b4f0f41d +size 7219 diff --git a/marked/F/T-REC-F.748.79-202512-I_PDF-E/1b5a812c8aa20fd5cba28e97001d32de_img.jpg b/marked/F/T-REC-F.748.79-202512-I_PDF-E/1b5a812c8aa20fd5cba28e97001d32de_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..3c1b76a6cf0fcd8d33708f01fe92ddf0dfcf72c9 --- /dev/null +++ b/marked/F/T-REC-F.748.79-202512-I_PDF-E/1b5a812c8aa20fd5cba28e97001d32de_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:89f3d046b48407fc51d04d9a36214d54ef553ffd558093c71f1d9e9fe7c7f87a +size 122361 diff --git a/marked/F/T-REC-F.748.79-202512-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg b/marked/F/T-REC-F.748.79-202512-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..9e4809ea1bf5f4190140b3a6c77d3d1a37fcffa4 --- /dev/null +++ b/marked/F/T-REC-F.748.79-202512-I_PDF-E/a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:9b11b900eb4bed59b19299bf533470e9cfdc3ab511bc26d5102e75b73828449b +size 90791 diff --git a/marked/F/T-REC-F.748.79-202512-I_PDF-E/raw.md b/marked/F/T-REC-F.748.79-202512-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..06ef319fcf55f9069cee6a90f45d2e553c2145cf --- /dev/null +++ b/marked/F/T-REC-F.748.79-202512-I_PDF-E/raw.md @@ -0,0 +1,529 @@ + + +# Recommendation **ITU-T F.748.79 (12/2025)** + +SERIES F: Non-telephone telecommunication services + +Multimedia services + +--- + +## **Requirements and framework of artificial intelligence (AI)-based multimedia data generation systems using core cloud and edge cloud** + +![ITU logo](0538daaa5583c23e17db3a12f2281a55_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.748.79 + +# Requirements and framework of artificial intelligence (AI)-based multimedia data generation systems using core cloud and edge cloud + +## Summary + +AI-based multimedia data generation systems require cloud computing capabilities for training large-scale models with over billions of parameters but which can experience high latency due to the remote nature of the cloud. Edge servers can offer lightweight model training, fine-tuning and real-time inference services, which are less computationally and storage intensive. Therefore, Recommendation ITU-T F.748.79 identifies a reference framework and requirements of AI-based multimedia data generation systems using a core cloud and edge cloud. Use cases are also provided in an appendix. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.748.79 | 2025-12-14 | 21 | 11.1002/1000/16598 | + +## Keywords \* + +AI-based multimedia data generation, core cloud, edge cloud. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2026 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|------------------------------------------------------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Overview..... | 2 | +| 7 Requirements for AI-based multimedia data generation systems using core cloud and edge cloud ..... | 4 | +| 7.1 Requirements for multimedia data collecting and processing..... | 4 | +| 7.2 Requirements for training..... | 5 | +| 7.3 Requirements for inference ..... | 7 | +| 7.4 Requirements for service management ..... | 8 | +| 7.5 Requirements for application deployment..... | 8 | +| 8 Framework of AI-based multimedia data generation systems using core cloud and edge cloud..... | 8 | +| 8.1 Components of core cloud layer..... | 9 | +| 8.2 Components of edge cloud layer ..... | 9 | +| 8.3 Application layer ..... | 10 | +| 8.4 Components of system operation and management ..... | 10 | +| Appendix I – Use cases of AI-based multimedia data generation system using core cloud and edge cloud ..... | 11 | +| I.1 AIGC for autonomous driving using cloud and edge computing..... | 11 | +| Bibliography..... | 12 | + + + +# Requirements and framework of artificial intelligence (AI)-based multimedia data generation systems using core cloud and edge cloud + +# 1 Scope + +This Recommendation clarifies the requirements and reference framework of AI-based multimedia data generation systems using core cloud and edge cloud. The scope of this Recommendation includes: + +- overview +- requirements +- reference framework. + +Use cases of AI-based multimedia data generation systems using core cloud and edge cloud are provided in Appendix I. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 algorithm** [b-ISO/IEC 2382]: Finite set of rules for transforming input into output. + +**3.1.2 cloud computing** [b-ITU-T Y.3500]: Paradigm for enabling network access to a scalable and elastic pool of shareable physical or virtual resources with self-service provisioning and administration on-demand. + +**3.1.3 core cloud** [b-ITU-T Y.3508]: A cloud computing, which manages resource pools including resources in the edge of the network and enables cloud service. + +**3.1.4 edge cloud** [b-ITU-T Y.3508]: A cloud computing deployed to the edge of the network accessed by cloud service customers (CSCs) with small capacity resources enabling cloud service. + +**3.1.5 edge computing** [b-ITU-T Y.3073]: This refers to a strategy to deploy processing capability at network edge where end terminals are connected, and to perform the processing of data which is derived from and fed to the end terminals. + +**3.1.6 inference** [b-ISO/IEC 2382]: Reasoning by which conclusions are derived from known premises. + +## 3.2 Terms defined in this Recommendation + +None. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-------|--------------------------------------------| +| AI | Artificial Intelligence | +| API | Application Programming Interface | +| ASIC | Application-Specific Integrated Circuit | +| CPU | Central Processing Unit | +| CSC | Cloud Service Customer | +| CSP | Cloud Service Provider | +| DL | Deep Learning | +| ECN | Explicit Congestion Notification | +| FPGA | Field-Programmable Gate Array | +| GPU | Graphics Processing Unit | +| ML | Machine Learning | +| NIC | Network Interface Card | +| NPU | Neural Processing Unit | +| PFC | Priority-based Flow Control | +| PII | Personally Identifiable Information | +| PTQ | Post-Training Quantization | +| RDMA | Remote Direct Memory Access | +| RLAIF | Reinforcement Learning with AI Feedback | +| RLHF | Reinforcement Learning with Human Feedback | +| RTT | Round-Trip Time | +| SDK | Software Development Kit | +| XML | extensible Markup Language | + +# 5 Conventions + +In this Recommendation: + +- The keywords "**is required**" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. +- The keywords "**is recommended**" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement needs not be present to claim conformance. + +# 6 Overview + +AI-based multimedia data generation services are usually based on large-scale pre-trained models with over billions of parameters, which require thousands of graphics processing units (GPUs) to train. The robust cloud computing capabilities of core cloud can be utilized to train AI-based multimedia data generation pre-training models, then users can access cloud-based AI-based multimedia data generation services via a core network by executing the models on core cloud servers. However, due to the remote nature, cloud services are subject to high latency, and so deploying interaction intensive AI-based multimedia data generation services on edge networks has been + +considered as a practical option. Unlike the large-scale infrastructure of core cloud computing, edge cloud limited resources often cannot support large-scale model training. But an edge cloud can offer lightweight model training, fine tuning and real-time inference services that are less computationally and storage intensive. + +A core cloud offers strong resource capabilities but suffers from long-distance transmission, while an edge cloud provides low transmission latency and enhanced privacy, as data can be processed locally without being transmitted to centralized core cloud servers, thereby reducing the risk of data leakage; however, it is limited by constrained computing resources. To support AI-based multimedia data generation services with high user experience, the utilization of an AI-based multimedia data generation system employing both a core cloud and edge cloud is envisioned as the most promising approach. + +The procedure of offering multimedia data generation services, including data collection, pre-training, fine tuning, inference and application. To achieve maximum efficiency in AI-based multimedia data generation systems using a core cloud and edge cloud, the coordination of resources, data, task orchestration, application management and service provisioning between the core cloud and edge cloud is crucial throughout the system's lifecycle. For example, pre-training is usually carried out in the core cloud because it needs higher computational resources. However, models in the edge need to be continuously trained and updated with the accumulation of data. At the same time, the limited local computing power and data resources on the edge are usually insufficient to support large-scale model training. Therefore, data and computation coordination need to be carried out across the device, edge and cloud. + +In this context, in order to enable the multimedia data generation systems to perform efficiently, it is necessary to clearly define the reference framework and specify the requirements of the systems. + +Figure 1 shows the overview of AI-based multimedia data generation systems using a core cloud and edge cloud. It demonstrates the core functions of the system in the core cloud and edge cloud. The core cloud provides AI model training and inference capabilities along with the required computational resources, enabling pre-training and training or inference tasks that exceed the capacity of edge devices. It also supports the management of training data and hosts applications for multimedia data generation. The edge cloud offers AI model training and inference capabilities for fine tuning training and real-time inference tasks, supports the collection and processing of on-device data, and similarly hosts applications for multimedia data generation. Deploying applications on both the core and edge cloud helps balance computing efficiency, latency, privacy and scalability. The core cloud handles heavy workloads including high definition video generation, while the edge cloud manages low-latency and privacy-sensitive tasks such as responsive conversational speech generation. This set-up allows flexible task allocation and improves user experience across different network and resource conditions. + +![Figure 1: Overview of AI-based multimedia data generation systems using core cloud and edge cloud. The diagram shows three layers: Core cloud, Edge clouds, and Device. The Core cloud layer contains a cloud icon with servers and a database, and a grid of functions: Image/Text/Audio/Video/3D generation application deployment, Service management, Data management, Pre-training, and Inference. The Edge clouds layer contains two cloud icons with servers and a database, connected by a double-headed arrow, and a grid of functions: Image/Text/Audio/Video/3D generation application deployment, Service management, Data collecting and processing, Fine tune training, and Inference. The Device layer contains icons for a laptop, smartphone, tablet, robot, and car. Vertical double-headed arrows connect the Core cloud to the Edge clouds, and the Edge clouds to the Device layer. A label F.748.79(25) is in the bottom right corner.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +Figure 1: Overview of AI-based multimedia data generation systems using core cloud and edge cloud. The diagram shows three layers: Core cloud, Edge clouds, and Device. The Core cloud layer contains a cloud icon with servers and a database, and a grid of functions: Image/Text/Audio/Video/3D generation application deployment, Service management, Data management, Pre-training, and Inference. The Edge clouds layer contains two cloud icons with servers and a database, connected by a double-headed arrow, and a grid of functions: Image/Text/Audio/Video/3D generation application deployment, Service management, Data collecting and processing, Fine tune training, and Inference. The Device layer contains icons for a laptop, smartphone, tablet, robot, and car. Vertical double-headed arrows connect the Core cloud to the Edge clouds, and the Edge clouds to the Device layer. A label F.748.79(25) is in the bottom right corner. + +**Figure 1 – Overview of AI-based multimedia data generation systems using core cloud and edge cloud** + +# 7 Requirements for AI-based multimedia data generation systems using core cloud and edge cloud + +## 7.1 Requirements for multimedia data collecting and processing + +#### 7.1.1 Data collecting + +- a) Data format + - 1) It is required to support accessing multiple data modalities. + - 2) It is required to support accessing the data in a compressed package format. +- b) Data source and importing + - 1) It is required to support collecting datasets from multiple data sources. + - 2) It is required to support multiple data importing methods. + - 3) It is required to support batch data importing. + - 4) It is required to support real-time data importing. + - 5) It is required to support collecting data from end devices at an edge cloud. + - 6) It is required to support data transferring from distributed edge cloud nodes to core cloud nodes. + +#### 7.1.2 Data processing + +- a) It is required to support data processing operations including data cleansing, data normalization, feature scaling, data augmentation and data anonymization. +- b) It is required to support data pairing in different modalities, including text-image, text-audio and text-video. +- c) It is required to support data processing methods including by manually, preconfigured rules and machine learning / deep learning (ML/DL) models. +- d) It is required to support batch data processing, streaming data processing and distributed data processing operations. + +#### **7.1.3 Dataset management** + +- a) It is required to support constructing meta-information of datasets. +- c) It is required to support constructing multiple datasets for the training process, including pre-training datasets, instruction fine-tuning datasets and evaluation datasets. +- d) It is recommended to support using inference results to update and expand datasets. +- e) It is required to support distributed storage, and accessing and management of datasets. +- f) It is required to support construction and maintenance of local datasets from end devices and users at an edge cloud. + +#### **7.1.4 Collaboration requirements** + +- a) It is required to manage the data collecting and processing strategy at a core cloud, as per the following. + - 1) Allocate network bandwidth resources based on the data upload volume of edge clouds, assigning a higher bandwidth to an edge cloud with larger data volumes to ensure efficient and speedy data transmission. + - 2) Allocate network bandwidth resources according to the traffic needs of specific data formats. For instance, allocate a higher bandwidth to video streams to ensure stable transmission and low latency. + - 3) Optimize data processing locations based on the workload status of a core cloud and each edge cloud to balance resource utilization. This includes either processing data locally at the edge cloud and then uploading or uploading raw data for processing on the core cloud. + +NOTE – Resource allocation and utilization management occur within the resources owned by the Cloud Service Provider (CSP). + +- b) It is required to centralize the metadata of all edge clouds for unified datasets' management at a core cloud. +- c) It is required to support control of the edge clouds' data collaboration, enabling data replication and migration across edge clouds at a core cloud. + +#### **7.1.5 PII protecting requirements** + +- a) It is required to get data usage consent before collecting personally identifiable information (PII). +- b) It is required to anonymize and encrypt PII when transferred between end devices and the edge cloud, between the edge cloud and the core cloud, and among edge clouds. + +## **7.2 Requirements for training** + +### **7.2.1 Pre-training requirements** + +- a) It is required that the pre-training of a large-scale model with over billions of parameters be performed on a core cloud. +- b) It is required to support preconfigured models and to provide metadata descriptions for the preconfigured models. +- c) It is required to support model integration methods. + +NOTE 1 – Model integration methods include local importing and remote access to models from third-party or public repositories. + +- d) It is required to support multimodalities generative model training. +- e) It is required to support a deep learning framework. +- f) It is required to support distributed training with multi-GPUs and multi-machines. + +- g) It is required to support parallel training methods. + +NOTE 2 – Parallel training methods includes data parallelism, tensor parallelism, pipeline parallelism and a mixed parallelism of these. + +- h) It is required to support monitoring the model training process. + +NOTE 3 – Resource utilization includes a processing unit (such as a central processing unit (CPU) or GPU), memory, storage and network utilization. + +NOTE 4 – Resource utilization occurs within the resources owned by the CSP. + +### **7.2.2 Fine tuning requirements** + +- a) It is required to support fine tuning based on trained models and specified datasets, including prompt tuning, full fine tuning, parameter-efficient fine tuning, reinforcement learning with human feedback (RLHF) and reinforcement learning with AI feedback (RLAIF). +- b) It is required to support performing fine tuning on an edge cloud or core cloud or as collaborated, based on pre-trained models from a core cloud. +- c) Other training requirements are referred to in d) to h) of clause 7.2.1. + +#### **7.2.3 Collaboration requirements** + +- a) It is required to support collaborative training between a core cloud and edge cloud as per the following. + - 1) An edge cloud side utilizes local datasets for local training, then transfers model parameters to the core cloud for aggregation. + - 2) Training on multi-edge cloud nodes can be performed in parallel or asynchronous according to the available status of multi-edge side nodes to improve training efficiency. + - 3) The core cloud side is responsible for monitoring performance data of edge side nodes and generating resource scheduling strategies for training tasks. The scheduling strategies are generated automatically by learning the history performance data of computing nodes in edge clouds. + +NOTE 1 – Performance data includes CPU/GPU utilization, storage I/O, network throughput, bandwidth, latency and training speed. + +NOTE 2 – Resource utilization monitoring occurs within the resources owned by the CSP. + +- 4) The core cloud allocates the training task to available computing nodes in the edge cloud and in an available performing time period according to the scheduling strategies. +- b) It is required to support collaborative training across multiple edge clouds. +- c) It is required to support federated learning, incremental learning and transfer learning methods between the core cloud and edge cloud, as well as among multiple edge clouds. + +#### **7.2.4 Core cloud resource requirements** + +- a) Computing + - 1) It is required to support using heterogeneous computing units for training, including CPUs, GPUs, neural processing units (NPUs), application-specific integrated circuit (ASICs) and field-programmable gate arrays (FPGAs). + - 2) It is required to utilize computing units supporting high-speed interconnect protocols. + - 3) It is required to support virtualization technologies for computing resources. +- b) Storage + - 1) It is required for the training cluster in the data centre to be configured with distributed storage and TB level data storage space to store massive training data and models with over billions of parameters. + +- 2) It is required to support storage types for multiple modalities' data including object storage, block storage, file storage, and parallel file storage. +- c) Network + - 1) It is required that the network between compute nodes, storage nodes, and between compute and storage nodes, utilize remote direct memory access (RDMA) lossless networking in cloud data centres. + - 2) It is required to support the monitoring and optimization of network bandwidth utilization during training. + - 3) It is recommended to support network congestion control algorithms during training, and the cloud data centre using switches and network interface cards (NICs) supporting a priority-based flow control (PFC) mechanism, round-trip time (RTT) detection and explicit congestion notification (ECN) awareness. + +## **7.3 Requirements for inference** + +- a) For resource requirements, refer to clause 7.2.4. +- b) It is required to support model deployment in a core cloud and edge cloud. +- c) It is required to deploy an inference accelerating framework supporting a multimodal model in a core cloud and edge cloud. +- d) It is required to adopt model lightening ways to support large size model inference execution on a computing resource-limited edge cloud, including model expressing, model quantization and model partitioning. +- e) It is required to support model inference on a core cloud, edge cloud or with collaborative inference. Collaborative inference is based on methods including model partitioning, model selection and multi-model result aggregation, and collaboration occurs between the core cloud and edge cloud or across multiple edge clouds. +- f) It is required to support inference tasks scheduling between a core cloud and edge cloud. The decision on task executing location is calculated considering accuracy, latency, load balance and resource optimization. +- g) It is required to support the determination of inference models and their deployment strategies. + +NOTE 1 – The target model is selected based on the cost value calculated from candidate models, and the deployment strategy is determined according to a model's state, including whether it is already deployed and where it can be deployed. + +NOTE 2 – Candidate models refer to models that meet the received task type and user requirements. The cost value is calculated based on cost indicators corresponding to the state of each candidate model. + +NOTE 3 – The model with the optimal cost value is the target model. If the saved model information shows that it has been deployed in the edge cloud, the cost value calculation can ignore its deployment and transmission latency. + +- h) It is required to support model caching strategies in the edge cloud, comprehensively considering model usage frequency, hit rate and storage space. +- i) It is recommended to support inference accelerating methods, including universal transformer fusion, dynamic quantization, post-training quantization (PTQ) and continuous batching. +- j) It is recommended to support distributed inference on multi-computing units, including model parallelism and pipeline parallelism. +- k) It is recommended to support different numerical data types and precision formats for inference operations. + +## 7.4 Requirements for service management + +- a) It is required to support service provision modes including application programming interfaces (APIs) and software development kits (SDKs). +- b) It is required to support models' management, including metadata maintenance, model testing and release. +- c) It is recommended to support plugin management and prompt management. +- d) It is recommended to support model performance monitoring. +- e) It is recommended to support customizing models based on the needs of users. + +## 7.5 Requirements for application deployment + +- a) It is required that the system support deployment of multimedia data generation applications on a core cloud or edge cloud is based on resource demand. +- b) It is recommended to provide message templates/input templates/query templates to guide user interactions. +- c) It is recommended to support interaction modes including browser-based access, standalone applications and programmatic integration via APIs. + +# 8 Framework of AI-based multimedia data generation systems using core cloud and edge cloud + +Figure 2 shows the reference framework of AI-based multimedia data generation systems using a core cloud and edge cloud, which consists of an application layer, core cloud layer and edge cloud layer, system operation and management. + +![Figure 2: Framework of AI-based multimedia data generation systems using core cloud and edge cloud. The diagram shows two main layers: Core cloud layer and Edge cloud layer, both with Application, Training, Inference, and Model management components. A separate box on the right lists Components of system operation and management, including Capability management, Collaboration management, and Security management (Authentication, Access, Content, System).](1b5a812c8aa20fd5cba28e97001d32de_img.jpg) + +The diagram illustrates the framework of AI-based multimedia data generation systems, organized into two primary layers and a management component. + +**Core cloud layer** + +- Application**: Image generation, 3D generation, Audio generation, Text generation, Video generation, ... +- Training** +- Inference** +- Model management** +- Multimodal data management** +- Task orchestration** +- Resource management** + +**Edge cloud layer** + +- Application**: Image generation, 3D generation, Audio generation, Text generation, Video generation +- Training** +- Inference** +- Model management** +- Multimodal data collecting and processing** +- Task execution** +- Resource management** + +**Components of system operation and management** + +- Capability management +- Collaboration management +- Security management**: Authentication, Access, Content, System + +F.748.79(25) + +Figure 2: Framework of AI-based multimedia data generation systems using core cloud and edge cloud. The diagram shows two main layers: Core cloud layer and Edge cloud layer, both with Application, Training, Inference, and Model management components. A separate box on the right lists Components of system operation and management, including Capability management, Collaboration management, and Security management (Authentication, Access, Content, System). + +**Figure 2 – Framework of AI-based multimedia data generation systems using core cloud and edge cloud** + +The application layer includes capabilities of image generation, audio generation, text generation, 3D generation and video generation. + +The core layer includes training, inference, model management, multimodal data management, task orchestration and resource management. + +The edge layer includes training, inference, model management, multimodal data collecting and processing, task execution and resource management. + +The components of system operation and management includes capability management, collaboration management and security management in the field with authentication, access, content and the system. + +## **8.1 Components of core cloud layer** + +#### **8.1.1 Core cloud training module** + +The training module executes training activities, which involves importing training data and the initial model, creation of the training environment, configuration hyperparameter and presenting the training. + +### **8.1.2 Core cloud inference module** + +The inference module executes the inference activities, which involves model deployment, resource configuration, processing inference requests, and carrying out inference and response inference results. + +#### **8.1.3 Core cloud model management module** + +The model management module executes the management activities of multimedia models, which involves model registration, storage, version and updating controls, model integration from edge clouds, and model compression, partitioning and distribution to edge clouds. + +#### **8.1.4 Multimodal data management module** + +The multimodal data management module executes the management activities of multimodal data, which involves data storage, data labelling, metadata management, data indexing and aggregation, vector database searching and content auditing of multimodal data. + +#### **8.1.5 Task orchestration module** + +The task orchestration module executes the task orchestration activities between the core cloud and edge cloud, which involves data processing collaboration, training and inference task allocation. + +#### **8.1.6 Core cloud resource management module** + +The resource management module executes the resource management activities in the core cloud and edge cloud, which involves monitoring and scheduling computing resources, storage resources and network resources. + +## **8.2 Components of edge cloud layer** + +#### **8.2.1 Edge cloud training module** + +The training module executes the fine-tune training activities for multimedia models, which involves training strategies' execution, importing local training datasets and the initial model from the core cloud, creation of the training environment, configuration hyperparameters and presenting the training. + +#### **8.2.2 Edge cloud inference module** + +The inference module executes the inference activities of multimedia models, which involves model deployment, resource configuration, processing inference requests, carrying out inference and response inference results, and model and result caching management. + +#### **8.2.3 Edge cloud model management module** + +The model management module executes the management activities of multimedia models, which involves model registration, storage, version and updating controls, model upload to core clouds and caching models. + +#### **8.2.4 Multimodal data collection and processing module** + +The multimodal data management module involves activities of collecting data from edge devices, executing multimodal data processing and uploading data to a core cloud. + +#### **8.2.5 Task execution module** + +The task execution module executes the task from a core cloud, which involves data processing collaboration, training and inference task allocation. + +#### **8.2.6 Resource management module** + +The resource management module executes the resource management activities in an edge cloud, which involves monitoring and scheduling computing resources, storage resources and network resources. + +## **8.3 Application layer** + +The application layer provides the multimedia data generation capabilities for users, input and output modalities including text, image, audio, video and 3D. It receives requests from users and invokes the inference module to generate results, which are then returned to the users. + +## **8.4 Components of system operation and management** + +- a) The capability management module involves the registration, deployment, release and updating of capabilities. +- b) Security management modules include access security, authentication security, content security and system security [b-ITU-T F.743.8]. + - 1) The authentication security module provides the mechanisms for authentication and authorization, and it permits only authorized users to access the system and use the system's services. + - 2) The access security module utilizes specified firewalls, gatekeepers and other network devices to ensure security for access to some special cloud computing services. + - 3) The content security module ensures the security of multimedia data and PII and checks the results of generated data to avoid harmful information. + - 4) The system security module provides troubleshooting mechanisms and the capability to resist various attacks. +- c) The collaboration management module involves collaboration strategies' configuration, including registration, updating and deletion. + +# Appendix I + +## Use cases of AI-based multimedia data generation system using core cloud and edge cloud + +(This appendix does not form an integral part of this Recommendation.) + +## I.1 AIGC for autonomous driving using cloud and edge computing + +Artificial intelligence-generated content (AIGC) technology is applicable across diverse aspects of autonomous driving, ranging from perception and motion prediction to traffic control and human-vehicle interaction. It can enhance environmental understanding, predict object movements and optimize driving paths. However, challenges such as high computational demand and the need for adaptability remain. An AI-based mm data generation system using core and edge cloud helps to satisfy these requirements. At the cloud layer, AIGC service providers operate, train and deploy models using extensive data and powerful computing resources, manage complex tasks and can customize and compress models for edge deployment. At the edge level, roadside units (RSUs) obtain fine-tuned models from the cloud, providing localized and timely AIGC services for vehicles. RSUs can handle lightweight driving-related tasks and only offload to the cloud when necessary. + +# Bibliography + +- [\[b-ITU-T F.743.8\]](#) Recommendation ITU-T F.743.8 (2019), *Requirements for a cloud computing platform supporting a visual surveillance system.* +- [\[b-ITU-T Y.3073\]](#) Recommendation ITU-T Y.3073 (2024), *Framework for service function chaining in information-centric networking.* +- [\[b-ITU-T Y.3500\]](#) Recommendation ITU-T Y.3500 (2014), *Information technology – Cloud computing – Overview and vocabulary.* +- [\[b-ITU-T Y.3508\]](#) Recommendation ITU-T Y.3508 (2019), *Cloud computing – Overview and high-level requirements of distributed cloud.* +- [b-ISO/IEC 2382] ISO/IEC 2382:2015, *Information technology – Vocabulary.* + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.749.1-201511-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/F/T-REC-F.749.1-201511-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..9002ee68e2b9ebf63d27d39ba8c73bdafb0e6be6 --- /dev/null +++ b/marked/F/T-REC-F.749.1-201511-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8df701536c25ab8246d2868de3c20c8a4e25168bb52c5eb9078278ab1b5b4fd8 +size 6859 diff --git a/marked/F/T-REC-F.749.1-201511-I_PDF-E/b28af4985cdef1e519e3aaf26561dcb3_img.jpg b/marked/F/T-REC-F.749.1-201511-I_PDF-E/b28af4985cdef1e519e3aaf26561dcb3_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..faede00b816e52ff823d64af381a7da9afed5cc4 --- /dev/null +++ b/marked/F/T-REC-F.749.1-201511-I_PDF-E/b28af4985cdef1e519e3aaf26561dcb3_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e156049224bf0738934cf757bbb5390d4f776af498d136eefa181278f52fa797 +size 69664 diff --git a/marked/F/T-REC-F.749.1-201511-I_PDF-E/b8661c6c54f72ecc7ff6cb05e47b2891_img.jpg b/marked/F/T-REC-F.749.1-201511-I_PDF-E/b8661c6c54f72ecc7ff6cb05e47b2891_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8e8adaf320eb95cfa0f69c5ce7bbe3941ee61759 --- /dev/null +++ b/marked/F/T-REC-F.749.1-201511-I_PDF-E/b8661c6c54f72ecc7ff6cb05e47b2891_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7b47e9378538898738545b39371a222159885fe2ef0ab3aa0f9a0e2c8acfa5c3 +size 89061 diff --git a/marked/F/T-REC-F.749.1-201511-I_PDF-E/dbe553cf16dd14073b89a8263a428664_img.jpg b/marked/F/T-REC-F.749.1-201511-I_PDF-E/dbe553cf16dd14073b89a8263a428664_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..dfab9eb9ff3fd9d988673ca0f6e7f2c7aac76f2a --- /dev/null +++ b/marked/F/T-REC-F.749.1-201511-I_PDF-E/dbe553cf16dd14073b89a8263a428664_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:cd392c0bea4cf33ff569fdd7fb7fba7de2d3b3b4c6a71a01727cb461378a583e +size 20653 diff --git a/marked/F/T-REC-F.749.1-201511-I_PDF-E/raw.md b/marked/F/T-REC-F.749.1-201511-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..ebdc4ba30d85b9d1dbd88950e0da2e7c506993d8 --- /dev/null +++ b/marked/F/T-REC-F.749.1-201511-I_PDF-E/raw.md @@ -0,0 +1,407 @@ + + +International Telecommunication Union + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**F.749.1** + +(11/2015) + +SERIES F: NON-TELEPHONE TELECOMMUNICATION +SERVICES + +Multimedia services + +--- + +**Functional requirements for vehicle gateways** + +Recommendation ITU-T F.749.1 + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) features a globe with a red lightning bolt striking across it. To the right of the globe, the text "International Telecommunication Union" is written in a blue, sans-serif font, with "ITU" in a larger, bold font above it. + +ITU logo + +International +Telecommunication +Union + +# ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multdestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| MULTIMEDIA SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.749.1 + +### Functional requirements for vehicle gateways + +## Summary + +A vehicle gateway (VG) is a device in a vehicle that enables communications between a device in the vehicle and another device which may be physically located either inside the vehicle or outside the vehicle. + +Recommendation ITU-T F.749.1 describes functional requirements for vehicle gateways, including transport functional requirements, networking functional requirements, network access functional requirements, communication with in-vehicle devices functional requirements and network access management and security functional requirements. This Recommendation also describes the network protocols and communications interfaces to support seamless wired and wireless connectivity in heterogeneous access network environments. + +This Recommendation specifies functional requirements for a VG supporting a variety of existing and new access technologies. The VG is to a large extent independent from specific communication technologies and specific intelligent transport system (ITS) applications. The VG architecture is intended to be an open architecture, which will make it easy for a manufacturer to implement, test and select an appropriate communications type according to the manufacturer's own requirements and network conditions. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.749.1 | 2015-11-29 | 16 | 11.1002/1000/12631 | + +## Keywords + +Functional requirements, gateway architecture, interfaces, vehicle gateway. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2016 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|------------------------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation ..... | 1 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 3 | +| 6 Overview of VG and VGP..... | 3 | +| 7 Functional requirements for a VG ..... | 4 | +| 7.1 Transport-related functional requirements ..... | 4 | +| 7.2 Networking-related functional requirements..... | 4 | +| 7.3 Network access-related functional requirements..... | 5 | +| 7.4 Functional requirements for communications with in-vehicle devices ..... | 7 | +| 7.5 Functional requirements for management and security..... | 7 | +| Bibliography..... | 9 | + + + +# Recommendation ITU-T F.749.1 + +### Functional requirements for vehicle gateways + +# 1 Scope + +This Recommendation specifies functional requirements for vehicle gateways (VGs), including transport functional requirements, networking functional requirements, network access functional requirements, communication-with-in-vehicle devices functional requirements, and network access management and security functional requirements. It also describes communications interfaces to support the seamless wired and wireless connectivity in the heterogeneous access network environments. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[IEEE 802.11] IEEE 802.11 (2012), *IEEE Standard for Information technology-Telecommunications and information exchange between systems Local and metropolitan area networks-Specific requirements – Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications*. [standards.ieee.org/about/get/802/802.11.html](http://standards.ieee.org/about/get/802/802.11.html) + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 functional entity** [b-ITU-T Y.2012]: An entity that comprises an indivisible set of specific functions. Functional entities are logical concepts, while groupings of functional entities are used to describe practical, physical implementations. + +**3.1.2 intelligent transport systems (ITS)** [b-ITU-T Y.2281]: ITS is defined as systems utilizing the combination of computers, communications, positioning and automation technologies to improve the safety, management and efficiency of terrestrial transport systems. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 nomadic devices:** Nomadic devices include all types of information and communication devices as well as entertainment devices that can be brought into the vehicle by the driver and/or passengers to be used while driving. Examples include mobile phones, portable computers, tablets, mobile navigation devices, portable media players and multi-functional smart phones. + +**3.2.2 vehicle gateway (VG):** A VG is a device in a vehicle that enables communications between a device in the vehicle and another device which may be physically located either inside the vehicle or outside the vehicle (e.g., roadside station, cloud-based server, etc.). A VG provides standardized interfaces and protocols, communications across heterogeneous networks, optimized network + +selection based on application needs and network QoS, arbitration and integration of network communications, security and switching network connections to maintain service continuity. + +**3.2.3 vehicle gateway platform (VGP):** A VGP is the collection of ICT hardware and software in a vehicle operating as an open platform to provide an integrated runtime environment for delivering the communications services of a VG. A VGP may also provide higher layer communications services such as interaction with the driver through the driver-vehicle access services and so on. Subsystems dedicated solely to vehicle operation are not considered part of the VGP. Supported applications/services include ITS and infotainment. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|--------|--------------------------------------------------| +| 2G | Second Generation of cellular phone technologies | +| 3G | Third Generation of cellular phone technologies | +| 4G | Fourth Generation of cellular phone technologies | +| CAN | Controller Area Network | +| CI | Communication Interface | +| D2D | Device-to-Device | +| DSRC | Dedicated Short Range Communication | +| EAP | Extensible Authentication Protocol | +| ECU | Electronic Control Unit | +| FM-RDS | Frequency Modulation Radio Data System | +| GNSS | Global Navigation Satellite System | +| ICT | Information and Communication Technology | +| IPv4 | Internet Protocol version 4 | +| IPv6 | Internet Protocol version 6 | +| IR | Infrared | +| ITS | Intelligent Transport System | +| NAT | Network Address Translation | +| OSI | Open Systems Interconnection | +| RSU | Road Side Unit | +| SIM | Subscriber Identity Module | +| SPI | Stateful Packet Inspection | +| TCP | Transport Control Protocol | +| UDP | User Datagram Protocol | +| VG | Vehicle Gateway | +| VGP | Vehicle Gateway Platform | +| V2I | Vehicle-to-Infrastructure | +| V2V | Vehicle-to-Vehicle | +| WEP | Wired Equivalent Privacy | + +WLAN      Wireless Local Area Network + +WPAN      Wireless Personal Area Network + +# 5      Conventions + +None. + +# 6      Overview of VG and VGP + +A vehicle gateway platform (VGP) is a collection of information and communication technology (ICT) hardware and software in a vehicle operating as an open platform to provide an integrated runtime environment for delivering the communications services of a vehicle gateway (VG). The VGP may also provide higher layer communications services such as interaction with the driver through the driver-vehicle access services and so on. Subsystems dedicated solely to vehicle operation are not considered part of the VGP. Supported applications/services include intelligent transport system (ITS) and infotainment. The VGP functional layer structure model follows the principles of the open systems interconnection (OSI) model for layered communication protocols. Based on the VGP framework, the VGP functionality straddles across OSI layers 1 to 7, whereas the VG functionality covers OSI layers 1 to 4. The VG includes transport functions, networking functions and network access functions. The coloured block in Figure 1 shows the location of a VG within the VGP. + +![Figure 1: Scope of VG within the VGP. A diagram showing three stacked layers. The top layer is 'ITS applications'. The middle layer is 'Service functions'. The bottom layer is a yellow block labeled 'Transport, networking, network access functions'. To the right, a vertical double-headed arrow labeled 'VGP' spans the top two layers. Another vertical double-headed arrow labeled 'VG' is inside the bottom yellow block. The label 'F.749.1(15)_F01' is at the bottom right.](dbe553cf16dd14073b89a8263a428664_img.jpg) + +Figure 1: Scope of VG within the VGP. A diagram showing three stacked layers. The top layer is 'ITS applications'. The middle layer is 'Service functions'. The bottom layer is a yellow block labeled 'Transport, networking, network access functions'. To the right, a vertical double-headed arrow labeled 'VGP' spans the top two layers. Another vertical double-headed arrow labeled 'VG' is inside the bottom yellow block. The label 'F.749.1(15)\_F01' is at the bottom right. + +**Figure 1 – Scope of VG within the VGP** + +Figure 2 shows the functional layers of a VG. + +![Figure 2: Functional layers of a VG. A diagram showing the functional layers of a VG. At the top are two yellow blocks: 'Transport' and 'Networking'. Below these are three columns of communication interfaces. The first column, 'Communication for nomadic devices', includes 'USB', 'Wireless LAN', and 'Short range wireless', connected to three mobile phones. The second column, 'Communication for the external networks', includes 'Cellular', 'Wireless LAN', and 'Short-to-medium range wireless', connected to a cell tower, a mobile phone, and a sensor. The third column, 'Communication for in-vehicle devices', includes 'In-vehicle buses', connected to 'Sensors' and 'ECUs'. At the bottom, a box labeled 'Servers/service platform/RSUs' is connected to the external network interfaces. The label 'F.749.1(15)_F02' is at the bottom right.](b28af4985cdef1e519e3aaf26561dcb3_img.jpg) + +Figure 2: Functional layers of a VG. A diagram showing the functional layers of a VG. At the top are two yellow blocks: 'Transport' and 'Networking'. Below these are three columns of communication interfaces. The first column, 'Communication for nomadic devices', includes 'USB', 'Wireless LAN', and 'Short range wireless', connected to three mobile phones. The second column, 'Communication for the external networks', includes 'Cellular', 'Wireless LAN', and 'Short-to-medium range wireless', connected to a cell tower, a mobile phone, and a sensor. The third column, 'Communication for in-vehicle devices', includes 'In-vehicle buses', connected to 'Sensors' and 'ECUs'. At the bottom, a box labeled 'Servers/service platform/RSUs' is connected to the external network interfaces. The label 'F.749.1(15)\_F02' is at the bottom right. + +**Figure 2 – Functional layers of a VG** + +The network access functional layer can be divided into three interface groups between a VG and internal or external devices/networks as follows: + +- Interfaces for nomadic devices, which are used for communication between the VG and consumer devices. +- Interfaces for external devices using networks such as cellular communications, short-to-medium range wireless communication such as legacy dedicated short range communication (DSRC), [IEEE 802.11] (part of wireless access in vehicular environments), etc. which are used to provide communications for ITS services. +- Interfaces for accessing in-vehicle devices such as sensors and electronic control units (ECUs) through the in-vehicle buses like the controller area network (CAN) bus. + +The upper layers handle transport functions and networking layers handle routing functions, reliable data delivery of service data, etc. + +# 7 Functional requirements for a VG + +Figure 3 shows the functional blocks for a VG. VG functional blocks include transport functional blocks, networking functional blocks, network access functional blocks, wired and wireless access management functional blocks and security functional blocks. + +![Figure 3 – VG functional blocks diagram showing a layered architecture. The top layer is 'Security functions' containing 'Transport functions' (TCP, UDP, Other protocols) and 'Networking functions' (IPv4, IPv6, Other protocols). The bottom layer is 'Wired and wireless access management functions' containing 'Communication interfaces for nomadic devices' (Wired access CI, Wireless LAN CI, Short range wireless CI), 'Communication interfaces for the external networks' (Cellular CI, Wireless LAN CI, Short-to-medium range wireless CI, ...), and 'Communication interfaces for in-vehicle devices' (In-vehicle buses CI, ...).](b8661c6c54f72ecc7ff6cb05e47b2891_img.jpg) + +(\*All CIs stand for communication interfaces) + +Figure 3 – VG functional blocks diagram showing a layered architecture. The top layer is 'Security functions' containing 'Transport functions' (TCP, UDP, Other protocols) and 'Networking functions' (IPv4, IPv6, Other protocols). The bottom layer is 'Wired and wireless access management functions' containing 'Communication interfaces for nomadic devices' (Wired access CI, Wireless LAN CI, Short range wireless CI), 'Communication interfaces for the external networks' (Cellular CI, Wireless LAN CI, Short-to-medium range wireless CI, ...), and 'Communication interfaces for in-vehicle devices' (In-vehicle buses CI, ...). + +F.749.1(15)\_F03 + +**Figure 3 – VG functional blocks** + +## 7.1 Transport-related functional requirements + +The VG should support several transport protocols including UDP/TCP. The VG should also support the network address translation (NAT) function to provide Internet access to all in-vehicle devices. + +## 7.2 Networking-related functional requirements + +The VG should support multiple optional and complementary network protocols running independent of each other: + +- VG shall support IP protocols, e.g., IPv4 or IPv6 for Internet connectivity including the routing capability to the selected network. + +- VG should support other network protocols. These protocols are meant to support applications with severe timing constraints and low latency requirements, e.g., time-critical safety related applications, road safety and traffic efficiency applications. + +## **7.3 Network access-related functional requirements** + +In this Recommendation, network access covers the OSI model physical layer (PHY) (connecting physically to the communication medium) and data link layer (DLL), which may be sub-divided into medium access control (MAC) sub-layer managing the access to the communication medium, and logical link control (LLC) sub-layer. Communication interface (CI) is an implementation of a network access technology which is uniquely selectable by means of a CI identifier. + +The VG should provide wired and wireless CIs as follows: + +- Wired access such as USB. +- Wireless access such as 2G/3G/4G, [IEEE 802.11] (part of wireless access in vehicular environments), legacy DSRC, etc., which are used to communicate with devices outside the vehicle. Wireless accesses such as wireless local area network (WLAN) and short range wireless such as wireless personal area networks (WPAN) communication are used for communication with in-vehicle nomadic devices (e.g., smartphone). + +### **7.3.1 Functional requirements for communications with nomadic devices** + +The VG should support interfaces for consumers to access an in-vehicle modules/network via nomadic devices. These interface functions include the following functional blocks: + +- USB CI + +The VG should provide USB CI which supports nomadic devices in a vehicle such as a smartphone and/or PC connected to VG to exchange data between them, e.g., a smartphone or PC to read vehicle state information via in-vehicle connection interfaces for checking/diagnosing the vehicle status. Some post-installed devices such as surveillance/monitoring cameras can also be connected to the VG via USB for the specific VGP applications. + +- Wireless LAN/short range wireless CI + +The VG should provide communication interfaces, such as WLAN, for interacting with nomadic devices, for example to share their screens with the vehicle display, i.e., to project their internet applications and content (e.g., Web browsing, navigation) onto the vehicle display. VG should allow nomadic devices to connect to the VG through this CI and use the VG as a gateway to access the Internet. + +### **7.3.2 Functional requirements for communications with the external networks** + +##### **7.3.2.1 Requirements for cellular CI** + +The VG should support cellular CIs which include CIs for 2G, 3G, 4G and future cellular technologies. They shall operate and conform to the regulatory limits and parameters defined in regional and national regulations. + +A cellular CI shall support establishment and termination of a medium-dependent session. It is necessary to follow one of the connection establishment procedures defined in cellular communications standards and the procedures defined in the relevant cellular communications protocols shall be followed. + +A cellular CI shall support and provide the functionality to monitor communications connection state changes during the session, when a change of the status of a specific medium occurs, its MAC shall operate in accordance with the relevant specifications. When the communications connection changes to other access networks, e.g., one of the other cellular communications networks, it shall + +immediately notify this to the wireless access management described in clause 7.5.1 and the handover shall follow the mechanism defined therein. The session shall then be maintained by the other cellular communications network. When the session ends, the cellular communication connection can be closed through the methods defined in the cellular communication standards. Once the appropriate procedures defined in cellular communications standards to close the connection are completed, the cellular CI shall notify this information to the wireless access management described in clause 7.5.1. + +#### **7.3.2.2 Requirements for wireless LAN CI** + +In addition to the in-vehicle communication interfaces, a VG shall support wireless LAN CI to get Internet access via a nomadic device (e.g., mobile phone). The VG connects to the nomadic device using wireless LAN and uses the device as a gateway to access the Internet. The method used to connect cellular communication systems depends on the connected nomadic device. + +#### **7.3.2.3 Requirements for short-to-medium range wireless CI** + +Short-to-medium wireless CIs are used to provide vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications in order to satisfy the time-critical safety related applications, traffic efficiency applications, co-operative local services and payment services. Short-to-medium range wireless CIs may include CIs for [IEEE 802.11] (part of wireless access in vehicular environments) or 4G D2D (device-to-device). + +The VG should support integration of wireless CIs, such as [IEEE 802.11] (part of wireless access in vehicular environments) CI or 4G D2D CI. Once the standards wireless CIs are adopted, then they shall follow the related active specifications and comply in accordance with internationally adopted practices, limits and parameters defined in regional and national regulations. Short-to-medium range wireless CIs may include a CI for legacy DSRC. + +The VG should support DSRC CI which follows the related specifications in use, complying with the limits and parameters defined in regional and national regulations, e.g., the European Committee for Standardization (CEN) and should be in accordance with internationally adopted practices. + +#### **7.3.2.4 Functional requirements for other CIs** + +Besides cellular communications and the short-to-medium range communications listed above, other outside-vehicle communications include global navigation satellite system (GNSS) and infrared (IR), millimetre (mm) wave communications, etc. CIs for IR and mm wave communications can be directional in nature and may be useful to confine communication to a specific object. With strong capabilities to "beam" information in dedicated directions, IR communication can support localized directed communication, e.g., between successive vehicles and lane-selective transmission. mm Wave communication experiences different physical propagation properties compared to IR and can complement IR for safety-related applications. + +###### **– GNSS communications** + +The VG shall support integration of a geographic location module, such as GNSS, to pinpoint the geographic location of a user's receiver anywhere in the world. The location module provides the basic information from which the vehicle position can be calculated. In addition, the information can be combined with vehicle data from sensors such as odometers or radars as well as with other external sources of information (assisted GNSS data, etc.) to provide location information and navigation requirements. + +###### – Radio broadcast + +The VG shall support a radio broadcast CI which follows the related standard, e.g., frequency modulation radio data system (FM-RDS), complying with the spectrum defined in regional and national regulations and in accordance with internationally adopted practices. + +###### – IR and mm Wave + +The VG should support IR and mm wave CIs, which can be used to support localized directional communication for safety related applications, if applicable. These CIs experience different propagation characteristics but offer different simultaneous communication paths which are often complementary to each other. + +## **7.4 Functional requirements for communications with in-vehicle devices** + +The VG shall support CIs to connect with the in-vehicle network (e.g., CAN bus interface protocol). This CI can be used to collect (read only) vehicle information from ECUs and sensors, e.g., engine control, lighting, air conditioning, power locks, active suspension, power seats, airbag, etc. The CI can also be used by backend servers and nomadic devices to remotely control (read and write) the vehicle behaviour while security is guaranteed and communication authorized. + +The VG should support CIs to connect directly to devices built into a vehicle using standard serial or parallel interfaces (e.g., Ethernet, RS-232) to read information from them. + +## **7.5 Functional requirements for management and security** + +### **7.5.1 Functional requirements for wired and wireless access management** + +The VG should support management of multiple wired and wireless access network protocols and can make optimal use of all these resources to support handover between the same CI and different CIs. One possible handover involves the maintenance of a session when VG moves from one network to another network using the same access technology. Another kind of handover involves the maintenance of a session when a VG switches from one network to another network using different access technology. Both kinds of handovers should be supported. + +The VG should track the status of the dynamically changing mobile network and provide an access management information base (MIB) containing the configuration and current status information and be notified when the status of the medium changes. For example, the wireless access management function shall immediately receive a notification event terminated by a medium-dependent method via detection of the loss of signal as specified by the equipment manufacturer. This information comes from the cellular CI, short-to-medium range wireless CIs and other CIs. + +The VG should provide functions to manage a communication session according to the methods specified in the relevant wireless network standards. The VG should also support mechanisms or strategies to establish, manage and disconnect networks based on user profiles. Strategy profiles maybe configured based on time, location, preferred communication channels (all accesses are transparent to applications), etc. in the hybrid network environment. + +The VG should support implementation of CIs in a modular fashion to allow plug and play functionality. The VG architecture shall be an open architecture so that new air interfaces can easily be integrated into it at any time. + +### **7.5.2 Functional requirements for security** + +The VG security functions cover the transport, networking and network access security requirements. The VG security function shall implement the standard security protocols associated with the internationally adopted standardized CIs. + +The VG shall support functions that prevent non-authorized access from the external and internal networks. One or several firewall functions, e.g., stateful packet inspection (SPI) filtering, MAC filtering, IP address filtering, etc. should be used. + +The VG should support one or several encryption modes, e.g., static wired equivalent privacy (WEP) encryption, etc. + +The VG should comply with one or several authentication methods along with authorization and profile management, e.g., MAC authentication, EAP (extensible authentication protocol)-SIM (subscriber identity module) authentication, and EAP-PEAP (protected EAP) authentication, etc. + +## Bibliography + +- [b-ITU-T X.200] Recommendation ITU-T X.200 (1994), *Information technology – Open Systems Interconnection – Basic Reference Model: The basic model.* +- [b ITU-T Y.2012] Recommendation ITU-T Y.2012 (2010), *Functional requirements and architecture of next generation networks.* +- [b-ITU-T Y.2281] Recommendation ITU-T Y.2281 (2011), *Framework of networked vehicle services and applications using NGN.* +- [b-ETSI TS 302 665] ETSI TS 302 665 (2010), *Intelligent Transport Systems (ITS); Communications Architecture.* +- [b-ISO 21210] ISO 21210:2012, *Intelligent Transport Systems (ITS) – Communications access for land mobiles (CALM) – IPv6 Networking.* +- [b-ISO 21212] ISO 21212:2008, *Intelligent Transport Systems (ITS) – Communications access for land mobiles (CALM) – 2G cellular.* +- [b-ISO 21213] ISO 21213:2008, *Intelligent Transport Systems (ITS) – Communications access for land mobiles (CALM) – 3G cellular.* +- [b-ISO 21214] ISO 21214:2006, *Intelligent Transport Systems (ITS) – Communications access for and mobiles (CALM) – Infra-red systems.* +- [b-ISO 21216] ISO 21216:2012, *Intelligent Transport Systems (ITS) – Communications access for land mobiles (CALM) – Millimetre wave air interface.* +- [b-ISO 24102] ISO 24102:2010, *Intelligent Transport Systems (ITS) – Communications access for land mobiles (CALM) – Management.* +- [b-ISO 29281] ISO 29281 (2011), *Intelligent Transport Systems (ITS) – Communications access for land mobiles (CALM) – Non-IP networking.* + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git 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It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.749.19 + +# Framework and requirements of the data sharing service platform for electric vehicle charging + +## Summary + +Recommendation ITU-T F.749.19 specifies the framework of the data sharing service platform for electric vehicle (EV) charging. It also specifies the requirements of the platform including data collection, data pre-processing, data management, data service, application service and platform management. It is applicable to the architecture design, research and development of the data sharing service platform among EVs, charging stations and power grid. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.749.19 | 2025-08-13 | 21 | 11.1002/1000/16432 | + +## Keywords + +Charging station, data sharing, electric vehicles, power grid, vehicle gateway. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2025 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-----------------------------------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Overview..... | 2 | +| 7 Functional framework..... | 3 | +| 8 Requirements of the data sharing service platform for EV charging ..... | 4 | +| 8.1 Requirements for data collection..... | 4 | +| 8.2 Requirements for data pre-processing ..... | 5 | +| 8.3 Requirements for data management ..... | 5 | +| 8.4 Requirements for data service ..... | 5 | +| 8.5 Requirements for application service ..... | 5 | +| 8.6 Requirements for platform management ..... | 6 | +| Appendix I – Use cases of the data sharing service platform for EV charging ..... | 7 | +| I.1 The charging guide application ..... | 7 | +| I.2 The charging station planning application ..... | 7 | +| I.3 The safe charging application..... | 7 | +| Bibliography..... | 8 | + + + +# Framework and requirements of the data sharing service platform for electric vehicle charging + +# 1 Scope + +This Recommendation specifies the framework and requirements of the data sharing service platform for electric vehicle (EV) charging, which provides efficient data interaction and sharing between multiple entities in the charging network and supports applications such as charging guide, charging station planning, safe charging and vehicle to grid (V2G). + +The Recommendation is applicable to the architecture design and development of the data sharing service platform among EVs, charging stations and power grid. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a standalone document, the status of a Recommendation. + +[ITU-T F.749.1] Recommendation ITU-T F.749.1 (2015), *Functional requirements for vehicle gateways*. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 charging station management system** [b-IEC 63110-1]: System responsible for managing charging infrastructures. + +**3.1.2 electric vehicle (EV)** [b-ISO 15118-1]: All road vehicles, including plug-in hybrid road vehicles (PHEV), that derive all or part of their energy from on-board rechargeable energy storage systems (RESS). + +**3.1.3 electric vehicle supply equipment** [b-ISO 15118-1]: Conductors, including the phase(s), neutral and protective earth conductors, the EV couplers, attached plugs, and all other accessories, devices, power outlets or apparatuses installed specifically for the purpose of delivering energy from the premises wiring to the EV and allowing communication among them as necessary. + +**3.1.4 energy management system (EMS)** [b-ITU-T X.1111]: A computer system comprising a software platform providing basic support services and a set of applications providing the functionality needed for the effective operation of electrical generation and transmission facilities so as to ensure adequate security of the energy supply at a minimum cost. + +**3.1.5 EV charging station** [b-IEC 61851-1]: Stationary part of electric vehicle (EV) supply equipment connected to the supply network. + +**3.1.6 power grid** [b-ITU-T F.751.5]: The whole consisting of substations of various voltages and transmission and distribution lines in the power system. + +**3.1.7 vehicle gateway (VG)** [ITU-T F.749.1]: A VG is a device in a vehicle that enables communications between a device in the vehicle and another device which may be physically located either inside the vehicle or outside the vehicle (e.g., roadside station, cloud-based server, etc.). A VG provides standardized interfaces and protocols, communications across heterogeneous networks, optimized network selection based on application needs and network QoS, arbitration and integration of network communications, security and switching network connections to maintain service continuity. + +## 3.2 Terms defined in this Recommendation + +None. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|------------------------------------| +| CSMS | Charging Station Management System | +| EMS | Energy Management System | +| EV | Electric Vehicle | +| EVSE | Electric Vehicle Supply Equipment | +| PHEV | Plug-in Hybrid road Vehicle | +| RESS | Rechargeable Energy Storage System | +| SOC | State of Charge | +| V2G | Vehicle to Grid | +| VG | Vehicle Gateway | + +# 5 Conventions + +In this Recommendation: + +- The keywords "**is required to**" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. +- The keywords "**is recommended**" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +# 6 Overview + +The rapid growth of EVs has brought significant challenges to charging facilities, power grid and charging services. At present, EVs can interact with the power grid in real time through electric vehicle supply equipment (EVSE). However, the existing charging network fails to realize effective data exchange and sharing, and the entire charging network operates inefficiently, raising problems such as poor charging service experience, low utilization rate of equipment and unfriendly vehicle-grid interaction. In order to realize effective data exchange and sharing among various entities, it is necessary to establish a data sharing service platform of the charging network. With the help of the platform, the charging service experience, equipment utilization and vehicle-grid interaction can be improved. Considering that the platform involves the interaction and fusion of multi-source data, this Recommendation specifies the framework and requirements of the data sharing service platform among EVs, charging stations and power grid to guarantee efficient data exchange and sharing between multiple entities in the charging network. + +Figure 1 shows the data flow of the data sharing service platform for EV charging. The demand side connects to the platform and obtains the required application services or data services. There are three + +types of data providers for the platform, including charging station, EVs and power grid. For the charging station, the charging station management system (CSMS) collects the data from charging piles and transmits the in-demand data to the platform. For the EV, the vehicle gateway (VG) [ITU-T F.749.1] collects the data from the other devices in the vehicle and transmits the in-demand data to the platform. For the power grid, the energy management system (EMS) collects the data from remote terminal units and transmits the in-demand data to the platform. + +Interfaces I1 to I4 provide communication with and from the platform, as follows: + +- Interface I1 supports the communication between the demand side and the platform. +- Interface I2 supports the communication between the CSMS and the platform. +- Interface I3 supports the communication between the VG and the platform. +- Interface I4 supports the communication between the EMS and the platform. + +![Figure 1: Data flow of the data sharing service platform for EV charging. The diagram shows a central 'The data sharing service platform for EV charging' box. Above it, a dashed box labeled 'Demand side' contains 'EV user', 'Charging operator', and 'Power grid company', connected via interface I1. Below the platform, three boxes represent 'Charging station' (containing CSMS and Charging piles), 'EV' (containing VG and In-vehicle devices), and 'Power grid' (containing EMS and Remote terminal units). These are connected to the platform via interfaces I2, I3, and I4 respectively.](b3baf3a29b67c7425d2562ddbc52f0cc_img.jpg) + +Figure 1: Data flow of the data sharing service platform for EV charging. The diagram shows a central 'The data sharing service platform for EV charging' box. Above it, a dashed box labeled 'Demand side' contains 'EV user', 'Charging operator', and 'Power grid company', connected via interface I1. Below the platform, three boxes represent 'Charging station' (containing CSMS and Charging piles), 'EV' (containing VG and In-vehicle devices), and 'Power grid' (containing EMS and Remote terminal units). These are connected to the platform via interfaces I2, I3, and I4 respectively. + +Figure 1 – Data flow of the data sharing service platform for EV charging + +# 7 Functional framework + +The functional framework of the data sharing service platform is shown in Figure 2. The framework is composed of six main functions including the data collection, the data pre-processing, the data management, the data service, the application service and the platform management. Each main function aggregates multiple other specific sub-functions, as the figure shows. + +![Figure 2: Functional framework of the data sharing service platform for EV charging. This is a grid diagram showing six main functions and their sub-functions. The main functions are Application service, Data service, Data management, Data preprocessing, Data collection, and Platform management. Sub-functions are categorized as 'Mandatory function' (solid border) or 'Non-mandatory function' (dashed border).](0b87abe67b21a93777287649c33e755d_img.jpg) + +| | | | | | | +|----------------------------|-------------------|----------------------------|----------------------|------------------------|----------------------------| +| Application service | Application index | Application interface | Application release | Application evaluation | Platform management | +| Data service | Data interface | Data index | Data analysis | | | +| Data management | Data examination | Data storage | Data classification | | | +| Data preprocessing | Data cleaning | Data integration | Data transformation | | | +| Data collection | EV side data | Charging station side data | Power grid side data | | | +| | | | | | Registration management | +| | | | | | Authority management | +| | | | | | Service management | +| | | | | | Operation monitoring | + +Legend:   Mandatory function      Non-mandatory function + +Figure 2: Functional framework of the data sharing service platform for EV charging. This is a grid diagram showing six main functions and their sub-functions. The main functions are Application service, Data service, Data management, Data preprocessing, Data collection, and Platform management. Sub-functions are categorized as 'Mandatory function' (solid border) or 'Non-mandatory function' (dashed border). + +Figure 2 – Functional framework of the data sharing service platform for EV charging + +The data collection functions consist of sub-functions to collect various data from multiple data sources, including EV side data, charging station side data and power grid side data. To achieve data collection, data collection functions provide a data list to data sources, namely, EVs, charging stations and power grid, which specifies what data are required by the platform. The data sources transmit the required data to the functions according to the data list. + +The data pre-processing functions consist of sub-functions to process the collected raw data to guarantee the data quality for further usage, such as data cleaning, data integration and data transformation. The data cleaning function is to fix inaccurate data, fill in missing data, and delete redundant data. The data integration function is to integrate relevant data from multiple sources. The data transformation function is to transform various data formats from multiple sources into a uniform data format. + +The data management functions consist of sub-functions to manage the collected data after pre-processing, including data storage, data examination and data classification. The data storage function is to aggregate and store the data collected from multiple sources. Data examination is to examine the collected data to determine whether it satisfies the requirements of the data sharing platform. The data classification function is to classify the collected data according to their features and importance. + +The data service functions consist of sub-functions to provide the data service to satisfy the requirements of the demand side, including data interface, data index and data analysis. The data interface function is to provide interfaces for users in the demand side to access the required data. The data index function is to provide a data list that covers all the accessible data in the data sharing service platform. The data analysis function is to analyse the collected data using statistical methods. + +Application service functions consist of sub-functions to satisfy the demand-side requirement, including application index, application release, application interface and application evaluation. The application index function is to provide a list of available applications in the data sharing service platform. The application release function is to support application developments and release developed applications based on the data sharing service platform. The application interface function is to provide the interface for users in the demand side to access the application. Application evaluation is to evaluate the application in the data sharing service platform according to the users' experiences described in questionnaires. In questionnaires, application users can give comments and scores according to their experiences. Based on the comments and scores, other users can more efficiently make a decision about the application they need. + +Platform management functions consist of sub-functions to manage and monitor the operation of the data sharing service platform, including registration management, authority management, service management and operation monitoring. The registration management function is to manage the registration of users' accounts. The authority management function is to manage the authority of users. The service management function is to manage the data service and application service of the data sharing service platform. The operation monitoring function is to monitor the operation of the data sharing service platform. + +The requirements of each function are described in the following clauses. + +# **8 Requirements of the data sharing service platform for EV charging** + +## **8.1 Requirements for data collection** + +DC-01: The data sharing service platform is required to collect heterogeneous data originated from multiple data sources, including EVs, charging stations and power grid. + +DC-02: The data sharing service platform is required to provide a data list to data sources, including EVs, charging stations and power grid, for data collection. + +DC-03: The data sharing service platform is recommended to support various data formats, such as data sets, logs and files, for data collection. + +DC-04: The VG in EV is required to have the capability to collect the data from in-vehicle devices based on the data list provided from the data sharing service platform. + +DC-05: The VG in EV is required to have the capability to transmit the related data from in-vehicle devices to the data sharing service platform based on the data list provided from the data sharing service platform. + +## **8.2 Requirements for data pre-processing** + +DP-01: The data sharing service platform is required to support data pre-processing. + +DP-02: The raw data provided by data collection functions, such as EVs, charging stations and power grid, is recommended to be pre-processed to improve the data quality. + +DP-03: The data pre-processing is recommended to cover data cleaning, data integration and data transformation. + +NOTE – This enables the platform to fix inaccurate values, merge relevant data from multiple sources and unify the various data formats. + +## **8.3 Requirements for data management** + +DM-01: The data sharing service platform is required to provide the functions for data storage. + +DM-02: It is recommended to support aggregation and storage for data collected from multiple data sources. + +DM-03: The data sharing service platform is required to provide data examination. + +DM-04: The data from EVs, charging stations and power grid is recommended to be examined. + +DM-05: The data sharing service platform is required to provide data classification. + +DM-06: The data from EVs, charging stations and power grid is recommended to be classified and assigned with corresponding levels according to the data feature and importance. + +## **8.4 Requirements for data service** + +DS-01: The data sharing service platform is required to provide the service of data index to allow the user in the demand side to access and check the data needed. + +DS-02: The data sharing service platform is required to provide the service of data interface for users in the demand side to access the data. + +DS-03: The data sharing service platform is recommended to provide the service of data analysis. + +## **8.5 Requirements for application service** + +AS-01: The data sharing service platform is required to provide the application index, which covers the available applications with detailed information such as the title and description of each application. + +NOTE – The application index is to allow the user in the demand side to access and check the application needed. + +AS-02: The data sharing service platform is required to provide the application interface for users in the demand side to access the application on the platform through the application interface, which can be applied directly or utilized for further development. + +AS-03: The data sharing service platform is required to provide the service of application release for users in the demand side to achieve the application development using the data collected by the + +platform, which is able to satisfy the users' requirements, such as charging guide, charging station planning and safe charging. + +AS-04: The data sharing service platform is recommended to provide the service of application evaluation. + +## **8.6 Requirements for platform management** + +PM-01: The data sharing service platform is required to provide task scheduling and resources monitoring for platform management. + +PM-02: The data sharing service platform is required to provide user management, including registration management, authority management, identity authentication and access control for platform management. + +PM-03: The data sharing service platform is required to provide data provider management, including identity authentication and access control for platform management. + +## Appendix I + +### Use cases of the data sharing service platform for EV charging + +(This appendix does not form an integral part of this Recommendation.) + +### I.1 The charging guide application + +The data sharing service platform is able to collect data from EVs, charging stations and power grid in real time. Once the EV user has a charging demand, the charging guide module developed on the data sharing service platform can help the user to make a charging plan to find a charging station and the corresponding route based on the real-time EV position, distribution of charging stations around, and the operating condition of charging piles at each station, which guide the user to reach the charging station with less waiting time. + +### I.2 The charging station planning application + +The data sharing service platform collects data from EVs, charging stations and power grid within the target region for the charging station planning application. The collected data includes the location of the charging station, the scale of charging stations, the charging quantity of EVs, and the capacity of the power distribution network. Based on the collected data, the optimization model minimizes the operating cost and maximizes user convenience. This model can be established in the platform, which can be utilized to determine the planning of the location and capacity of the charging station. + +### I.3 The safe charging application + +For the safe charging application, the platform collects data from EVs and charging stations, e.g., the vehicle and battery type, the voltage, current, state of charge (SOC), temperature during the charging process, and the voltage and current of the connected charging pile. Based on the collected data, the battery condition assessment model could be established in the platform, which helps the vehicle to obtain the battery status and provide safety actions based on the condition assessment and fault diagnosis. Through the data fusion of vehicle side and charging pile side, the battery fault diagnosis accuracy as well as the charging safety can be improved. + +# Bibliography + +- [b-ITU-T F.751.5] Recommendation ITU-T F.751.5 (2022), *Requirements for distributed ledger technology-based power grid data management*. +- [b-ITU-T X.1111] Recommendation ITU-T X.1111 (2016), *Supplement on security functional architecture for smart grid services using telecommunication networks*. +- [b-ISO 15118-1] ISO 15118-1:2019, Road vehicles – *Vehicle to grid communication interface – Part 1: General information and use-case definition*. +- [b-IEC 61851-1] IEC 61851-1:2017, *Electric vehicle conductive charging system – Part 1: General requirements*. +- [b-IEC 63110-1] IEC 63110-1:2022, *Protocol for management of electric vehicles charging and discharging infrastructures – Part 1: Basic definitions, use cases and architectures*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git 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TELECOMMUNICATION SERVICES + +Multimedia services + +--- + +**Vehicle domain service – General information +and use case definitions** + +Recommendation ITU-T F.749.5 + +**ITU-T** + +![ITU logo](1d7527f4316cfe2d342b08d1653d1592_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with a white grid pattern, overlaid by a stylized 'ITU' text in blue. + +ITU logo + +# ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +## **TELEGRAPH SERVICE** + +| | | +|-----------------------------------------------------------------|-------------| +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | + +## **MOBILE SERVICE** + +| | | +|--------------------------------------------------------|-------------| +| Mobile services and multdestination satellite services | F.110–F.159 | +|--------------------------------------------------------|-------------| + +## **TELEMATIC SERVICES** + +| | | +|-------------------------------------------|-------------| +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | + +## **MESSAGE HANDLING SERVICES** + +| | | +|--|-------------| +| | F.400–F.499 | +|--|-------------| + +## **DIRECTORY SERVICES** + +| | | +|--|-------------| +| | F.500–F.549 | +|--|-------------| + +## **DOCUMENT COMMUNICATION** + +| | | +|--------------------------------------|-------------| +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | + +## **DATA TRANSMISSION SERVICES** + +| | | +|--|-------------| +| | F.600–F.699 | +|--|-------------| + +## **MULTIMEDIA SERVICES** + +| | | +|--|--------------------| +| | F.700–F.799 | +|--|--------------------| + +## **ISDN SERVICES** + +| | | +|--|-------------| +| | F.800–F.849 | +|--|-------------| + +## **UNIVERSAL PERSONAL TELECOMMUNICATION** + +| | | +|--|-------------| +| | F.850–F.899 | +|--|-------------| + +## **ACCESSIBILITY AND HUMAN FACTORS** + +| | | +|--|-------------| +| | F.900–F.999 | +|--|-------------| + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.749.5 + +# Vehicle domain service – General information and use case definitions + +## Summary + +Recommendation ITU-T F.749.5 provides a basic definition of vehicle domain service and supplementary information on detailed concepts, as well as definitions of the typical and supplementary use cases being used to define the specification of applications. Connected vehicles are expected to expand and become even more popular in different markets worldwide. A variety of technologies is being developed and discussed for many applications. Detailed specifications of communications and applications are provided in other documents in the Recommendation ITU-T F.749 series; they are not provided in Recommendation ITU-T F.749.5. + +Recommendation ITU-T F.749.5 (2021) is technically aligned with ISO 23239-1. It was developed jointly by ITU-T Study Group 16 and ISO TC22/SC31 under the Joint Project Team on Vehicular Domain Service (JVDS). + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.749.5 | 2021-10-29 | 16 | 11.1002/1000/14792 | + +## Keywords + +Connected vehicles, intelligent transport systems, use cases, vehicle domain service, vehicular multimedia systems + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2021 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +###### Page + +| | | | +|------|-------------------------------------------------------------------------|----| +| 1 | Scope..... | 1 | +| 2 | Normative references..... | 1 | +| 3 | Terms and definitions ..... | 1 | +| 3.1 | Terms defined elsewhere..... | 1 | +| 3.2 | Terms defined in this Recommendation..... | 1 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | Conventions ..... | 3 | +| 5.1 | Documents overview on open systems interconnection-based services ..... | 3 | +| 5.2 | General policy structure ..... | 4 | +| 5.4 | Reference to subseries ..... | 5 | +| 6 | General information for vehicle domain service ..... | 5 | +| 6.1 | General ..... | 5 | +| 6.2 | Vehicle domain service ..... | 5 | +| 6.3 | Vehicle domain dynamic map service..... | 6 | +| 6.4 | Variations in vehicle domain services..... | 7 | +| 6.5 | Time synchronization in VDDMS..... | 14 | +| 6.6 | Other variations of vehicle domain services..... | 14 | +| 6.7 | System architecture of vehicle domain services..... | 16 | +| 6.8 | Network operators related to VDS ..... | 18 | +| 6.9 | VDS in smart traffic architecture model proposal..... | 19 | +| 6.10 | Information security in VDS ..... | 20 | +| 7 | Business use cases for VDS..... | 21 | +| 7.1 | General ..... | 21 | +| 7.2 | Business use case of vehicle domain registration..... | 21 | +| 7.3 | Business use case of traffic explorer ..... | 22 | +| 7.4 | Business use case of traffic reporter ..... | 23 | +| 7.5 | Business use case of manoeuvre coordinator ..... | 23 | +| 8 | System sequences for VDS..... | 24 | +| 8.1 | General ..... | 24 | +| 8.2 | Basic elements of a general BUC..... | 24 | +| 9 | System use cases for VDS ..... | 25 | +| 9.1 | General ..... | 25 | +| 9.2 | System use case of VDS start..... | 25 | +| 9.3 | System use case of communication set up ..... | 26 | +| 9.4 | System use case of security set up..... | 27 | +| 9.5 | System use case of VDS selection..... | 27 | +| 9.6 | System use case of VD data collection..... | 28 | +| 9.7 | System use case of VD status report ..... | 28 | + +| | Page | +|------------------------------------------------------------------------------------------|-------------| +| 9.8 System use case of driving manoeuvre query ..... | 29 | +| 9.9 System use case of VDS stop ..... | 30 | +| Appendix I – Scenario variations of vehicle domain dynamic map service ..... | 31 | +| I.1 General ..... | 31 | +| I.2 Scenario examples of traffic explorer service ..... | 31 | +| I.3 Scenario examples of traffic reporter service ..... | 33 | +| I.4 Scenario examples of manoeuvre coordinator service ..... | 34 | +| Appendix II – Typical examples of the smart traffic architecture model ..... | 36 | +| II.1 General ..... | 36 | +| II.2 Typical examples of the function domain service model ..... | 36 | +| II.3 Typical functional service in cooperation with VDS ..... | 40 | +| Appendix III – Reference model of vehicle domain service on vehicle multimedia system... | 42 | +| III.1 General ..... | 42 | +| III.2 Typical example of a reference model of VDS on VMS ..... | 42 | +| Bibliography ..... | 45 | + +# Introduction + +Connected vehicles are expected to expand and become even more popular in the markets of different countries. A variety of technologies is being developed and discussed for many applications. + +Everyone who drives a car collects traffic information to determine the correct driving behaviour, and accurately recognize relevant traffic information and driving conditions without delay. Although an autonomous driving function takes over driver operation, there is the same value in a judgement of correct driving behaviour. While many independent autonomous driving cars and intelligent driver assistance functions provide information collected by various sensors, light detection and ranging (LIDAR) and radio detection and ranging (RADAR), their performance is limited and the inaccuracies increase with ambient conditions, such as weather and blind spots. + +In addition, the blinkers with which all vehicles are normally equipped only provide one-way fragmentary information. If the vehicle communicates with other neighbouring vehicles or traffic participants and exchanges various pieces of information, it is able to go beyond the limits of its sensor capabilities and blind spots to provide a more accurate assessment of the traffic situation. It is also possible to negotiate planned driving manoeuvres with neighbouring vehicles and to coordinate the sequence and timing of driving manoeuvres. + +This ability to share information between vehicles defined in this Recommendation is provided only on a direct communication network between the vehicle and neighbouring traffic participants. It is accomplished with on-board functionality without investing in significant communication infrastructure on the road. This enables vehicles to make more accurate and appropriate driving choices, which provides a number of benefits, such as reducing traffic accidents and congestion, with improving traffic efficiency. + +An important aspect of this documentation development is the focus on implementation points throughout the vehicle. Typical use cases are collected, from which distinctive aspects of the implementation specification are derived. Beyond simple information exchange, the resulting information is reviewed, evaluated and then used to generate reliable information that can be applied to critical vehicle controls. + +ITU-T F.749.5 (technically aligned with [b-ISO 23239-1]) was developed to eliminate inconsistencies and redundancies within the terminology used currently for vehicle domain service documentation. As a result of these tasks, compatibility and interoperability are confirmed, in addition to the economy and efficiency of implementation with global consistency. Furthermore, by providing a concrete path from an existing simple and partial communication interface to trusted vehicle implementation, it is expected that a smooth launch of brand-new vehicle applications can be supported and the introduction accelerated of next generation communication technologies into the future vehicle market. + +Recommendation ITU-T F.749.5 (2021) is technically aligned with ISO 23239-1:2021 "Road vehicles – Vehicle domain service (VDS) – Part 1: General information and use case definitions" and it was developed jointly by ITU-T Study Group 16 and ISO TC22/SC31 under the Joint Project Team on Vehicular Domain Service (JVDS). + + + +# Recommendation ITU-T F.749.5 + +## Vehicle domain service – General information and use case definitions + +# 1 Scope + +This Recommendation provides a basic definition of vehicle domain service (VDS) and supplementary information on detailed concepts, as well as definitions of the typical and supplementary use cases being used to define the specification of applications. + +Detailed specifications of communications and applications are provided in other Recommendations in the series; they lie outside the scope of this Recommendation. + +NOTE – The remote processes by the tools connected to an on-board diagnosis connector in a vehicle, such as repair and maintenance, prognostics, monitoring, configuration and reprogramming of a vehicle lie outside the scope of this Recommendation. + +# 2 Normative references + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +# 3 Terms and definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +None. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 domain actor (DA):** Client of a master vehicle in a vehicle domain. + +NOTE – They are in general traffic participants, such as vehicles, bikes and walkers around the master vehicle. + +**3.2.2 domain vehicle (DV):** Vehicle client of a master vehicle in a vehicle domain. + +**3.2.3 domain participant (DP):** Client of a master vehicle except for vehicle in a vehicle domain. + +EXAMPLE – Walker, bike and other traffic participants with network function. + +**3.2.4 domain sensor (DS):** Client of a master vehicle in a vehicle domain with sensing function. + +NOTE 1 – It is the network entity and typically, a vehicle with network and sensing function is often both a domain vehicle and domain sensor at the same time. + +NOTE 2 – The general definition of domain sensor never excludes the domain actor except vehicle. + +**3.2.5 master vehicle (MV):** Server of vehicle domain. + +NOTE – This means the vehicle in which the server function implemented. + +**3.2.6 primary actor (PA):** Master vehicle or one of its clients in the vehicle domain. + +- 3.2.7 secondary actor (SA):** Logical or functional network entity outside the vehicle domain. +- 3.2.8 smart-city traffic manager (SCTM):** Central management server of traffic information in a smart city. +- 3.2.9 smart traffic:** Optimized traffic controlled by the smart city traffic manager in a smart city. +- 3.2.10 smart traffic architecture model proposal (STAMP):** Model proposal of the multi-layer-like control structure of smart traffic. +- 3.2.11 traffic monitor (TM):** Lower functional server of the smart-city traffic manager that monitors traffic status. +- 3.2.12 traffic operator (TO):** Lower functional server of the smart city traffic manager that manages traffic control information. +- 3.2.13 vehicle domain (VD):** Limited group of secure and reliable connections, provided by the master vehicle and established on an existing network service by registering the domain actor. +- NOTE – Vehicle domain is only related to network connection between master vehicle and domain actor. Physical or geometrical conditions are not included. +- 3.2.14 vehicle domain dynamic map (VDDM):** Dynamic map in the vehicle domain generated by a master vehicle. +- NOTE – VDDM consists of static high definition features, dynamic actors and other characteristics. +- 3.2.15 vehicle domain service (VDS):** Group of functions provided by the master vehicle to the domain actor in the vehicle domain. +- NOTE – It includes vehicle domain dynamic map. +- 3.2.16 vehicle domain service account (VDSA):** Unique identifier of the domain actor, certified and issued by the vehicle domain service operator. +- 3.2.17 vehicle domain service master time; VDS master time:** Basic time steps for synchronization between the master vehicle and the domain actor generated by the master vehicle. +- NOTE – It generates both past and future time steps. +- 3.2.18 vehicle domain service system (VDSS):** Physical structure that consists of the master vehicle (server), neighbouring vehicles (client), other traffic participants (clients), and a wireless network between the server and its clients that provides vehicle domain service. +- NOTE – An element in the VDSS is named as primary actor. Elements outside the VDS are named secondary actors. +- 3.2.19 vehicle domain service operator (VDSO):** Service operator who issues the vehicle domain service account. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-----|-------------------------| +| BUC | Business Use Case | +| DA | Domain Actor | +| DP | Domain Participant | +| DS | Domain Sensor | +| DV | Domain Vehicle | +| HMI | Human/Machine Interface | +| ID | Identifier | + +| | | +|-------|-------------------------------------------| +| IP | Internet Protocol | +| LDM | Local Dynamic Map | +| LEO | Low Earth Orbit | +| LIDAR | Light Detection And Ranging | +| LRT | Light-Rail Transit | +| MV | Master Vehicle | +| NTP | Network Time Protocol | +| OEM | Original Equipment Manufacturer | +| OSI | Open Systems Interconnection | +| PA | Primary Actor | +| PTP | Precision Time Protocol | +| RADAR | Radio Detection And Ranging | +| RF | Radio Frequency | +| Rx | Receiver | +| SA | Secondary Actor | +| SCTM | Smart-City Traffic Manager | +| STAMP | Smart Traffic Architecture Model Proposal | +| SUC | System Use Case | +| TCP | Transmission Control Protocol | +| TLS | Transport Layer Security | +| TM | Traffic Monitor | +| TO | Traffic Operator | +| Tx | Transmitter | +| UTC | Universal Time | +| VD | Vehicle Domain | +| VDA | Vehicle Domain Actor | +| VDDM | Vehicle Domain Dynamic Map | +| VDDMS | Vehicle Domain Dynamic Map Service | +| VDS | Vehicle Domain Service | +| VDSA | Vehicle Domain Service Account | +| VDSO | Vehicle Domain Service Operator | +| VDSS | Vehicle Domain Service System | +| VIN | Vehicle Identification Number | +| VMS | Vehicle Multimedia Service | + +# 5 Conventions + +## 5.1 Documents overview on open systems interconnection-based services + +Figure 1 shows the organization and coverage of the different ITU-T F.749.5 | ISO 23239-1 specifications on the OSI layered architecture. + +As indicated by the bold-framed enclosure, this Recommendation (technically aligned with [b-ISO 23239-1]) establishes general information and use case definitions. This Recommendation is the most basic document for the elaboration of other detailed and separate specific documents according to the OSI-layered architecture. + +![Diagram showing the organization and coverage of ITU-T F.749.5 | ISO 23239 specifications on the OSI layered architecture. The diagram maps OSI layers to specific parts of the recommendation series. OSI layers 7, 6, and 5 are grouped together and mapped to Part 2. OSI layers 4 and 3 are mapped to Part 3. OSI layers 2 and 1 are mapped to Part 4. Part 1 is shown separately at the top, covering general information and use case definitions. A legend at the bottom indicates that bold-framed boxes represent the current recommendation's coverage, while other boxes represent other parts of the series.](1439cb942d9e363bbb3161b5540dd8c6_img.jpg) + +**ITU-T F.749.5 | ISO 23239 vehicle domain service** + +| | | +|-----------------------------|--------------------------------------------------------------------------------------------------------------------| +| | ITU-T F.749.5 ISO 23239-1 Vehicle domain service
Part 1: General information and use case definitions | +| OSI layer 7
Application | ITU-T F.749.5 ISO 23239-2 Vehicle domain service
Part 2: Application layer and sequence requirements | +| OSI layer 6
Presentation | | +| OSI layer 5
Session | | +| OSI layer 4
Transport | ITU-T F.749.5 ISO 23239-3 Vehicle domain service
Part 3: Internet and transport layer requirements | +| OSI layer 3
Network | | +| OSI layer 2
Data link | ITU-T F.749.5 ISO 23239-4 Vehicle domain service
Part 4: Network interface layer requirements | +| OSI layer 1
Physical | | + +Legend: + +- Description coverage of this Recommendation +- Description coverage of other parts of this series + +Diagram showing the organization and coverage of ITU-T F.749.5 | ISO 23239 specifications on the OSI layered architecture. The diagram maps OSI layers to specific parts of the recommendation series. OSI layers 7, 6, and 5 are grouped together and mapped to Part 2. OSI layers 4 and 3 are mapped to Part 3. OSI layers 2 and 1 are mapped to Part 4. Part 1 is shown separately at the top, covering general information and use case definitions. A legend at the bottom indicates that bold-framed boxes represent the current recommendation's coverage, while other boxes represent other parts of the series. + +F.749.5(21) + +**Figure 1 – Overview of documents applicable to vehicle domain service** + +The upper layers are not suitable for proper transmission control protocol/Internet protocol (TCP/IP) communication. + +## 5.2 General policy structure + +This Recommendation provides policies for specifications as general information. The list of policies consists of recommendations, permissions, possibilities and capabilities. Additional statements are attached in order to provide better understanding. All policies are expressed in unified format. + +This Recommendation uses a policy structure, i.e., a unique number identifies each individual policy included within it, which improves readability with easier policy tracking. The following modified recommended format is applied: + +| | +|---------------------------------------| +| 'VDS''Y' – 'xxx' – policy name | +| {
policy text
} | + +where + +- VDS represents the series of standards; +- Y represents the document part of the series document set; +- xxx represents the individual policy number; +- policy name represents the name of policy; +- policy text describes the provisions of the policy; +- { and } delimit the starting and ending points of policy. + +EXAMPLE: + +| | +|--------------------------------------------------------------------------------------------------| +| VDS1-000 – The form of general policy | +| {
This sentence should give the example form of general policy defined in this document.
} | + +## 5.4 Reference to subseries + +In this Recommendation, reference to subsequent Recommendations in the series indicates other ITU-T Recommendations in the same subseries and their equivalent parts of the ISO International Standard. + +# 6 General information for vehicle domain service + +## 6.1 General + +A vehicle domain (VD) is an area that consists of road vehicles in which the applications are implemented. The applications provide integrated information services used in the vehicle. The information provided is generated from various sources of information, acquired by communication, concerned with the area around the vehicle, such as traffic conditions. The source information is acquired directly or indirectly by communication with neighbouring vehicles and other traffic participants (bikes, bicycles, walkers, etc.) without any support from roadside infrastructure. + +This clause gives basic definitions related to VDSs. + +## 6.2 Vehicle domain service + +The master vehicle (MV) generates a vehicle-domain network. Surrounding participants, such as vehicles, bikes and walkers, join that network as domain actors (DAs). Various types of sensor with which participants are equipped could also join it as additional actors. The MV may provide VDSs to the actors participating in its domain service network. + +| | +|---------------------------------------------------------------------------------------------------------------------------------| +| VDS1-001 – Vehicle domain service | +| {
If a vehicle is the master vehicle of the vehicle domain, it should provide vehicle domain services to domain actors.
} | + +Figure 2 shows a basic VDS. The MV communicates with DAs, such as domain vehicles (DVs), sensors and participants. The MV provides VDSs and DA respond to them. + +![Diagram of a basic vehicle domain service showing a master vehicle (2) within a vehicle domain (1) interacting with a domain participant (5), a domain vehicle (3), and a domain sensor (4).](4801720824e4b5e2361a5564f91cfb70_img.jpg) + +The diagram illustrates a basic vehicle domain service. A dashed circle labeled '1' represents the 'Vehicle domain'. Inside this domain, a 'Master vehicle' (2) is shown. To the left of the master vehicle is a 'Domain participant' (5), represented by a person icon. To the right of the master vehicle is a 'Domain sensor' (4), represented by a sensor icon. Further right is a 'Domain vehicle' (3), represented by a car icon. An arrow points from the master vehicle (2) to the domain participant (5). The background shows a road with a dashed line and solid lines, indicating a driving environment. + +Diagram of a basic vehicle domain service showing a master vehicle (2) within a vehicle domain (1) interacting with a domain participant (5), a domain vehicle (3), and a domain sensor (4). + +F.749.5(21) + +#### **Key** + +1 Vehicle domain 2 Master vehicle 3 Domain vehicle 4 Domain sensor 5 Domain participant + +**Figure 2 – Basic vehicle domain service** + +The minimum structure of a VDS consists of one MV and one DA. The field in which the VD is located includes everywhere the vehicle goes, such as a road that carries traffic, public parking area and private garage. + +VDS implementation depends on the decision of the original equipment manufacturer (OEM). Activation of an implemented VDS function depends on the decision of the user or owner, local regulation or other rules before driving. + +## **6.3 Vehicle domain dynamic map service** + +The most typical and original VDS is the vehicle domain dynamic map (VDDM) service, which is applied to vehicle driving with no restriction of location, i.e., on the road, street, freeway, public parking area and private road. + +The MV collects relevant information from all DAs. Domain sensors (DSs) report acquired information about silent traffic participants and conditions instead of DAs. The MV generates dynamic map information within the VD. The MV provides VDDM-based services to DAs. + +| | +|---------------------------------------------------------------------------------------------------| +| VDS1-002 – Vehicle domain dynamic map service | +| {
The master vehicle should provide vehicle domain dynamic map services to domain actors.
} | + +Figure 3 shows a typical vehicle domain dynamic map service (VDDMS). The MV communicates with the DAs, such as DVs, sensors and participants. The MV provides VDDM services and DAs respond to them. + +![Figure 3 – Typical vehicle domain dynamic map service. The diagram shows a road with a dashed line representing the vehicle domain boundary. A central white car (2) is the Master vehicle. Other cars (3, 4, 5) are Domain vehicles. Icons for a pedestrian (8), a cyclist (9), and another cyclist (10) represent Domain participants. Sensors (6, 7) are also shown. A dashed circle labeled '1' indicates the vehicle domain. A solid arrow points from the Master vehicle (2) to the Domain sensor (6).](33ed1f9b27c7c21c797aa928b0f06851_img.jpg) + +F.749.5(21) + +Figure 3 – Typical vehicle domain dynamic map service. The diagram shows a road with a dashed line representing the vehicle domain boundary. A central white car (2) is the Master vehicle. Other cars (3, 4, 5) are Domain vehicles. Icons for a pedestrian (8), a cyclist (9), and another cyclist (10) represent Domain participants. Sensors (6, 7) are also shown. A dashed circle labeled '1' indicates the vehicle domain. A solid arrow points from the Master vehicle (2) to the Domain sensor (6). + +#### Key + +| | | | | | | | | | | +|---|-----------------|---|-----------------|---|----------------------|---|----------------------|----|----------------------| +| 1 | Vehicle domain | 2 | Master vehicle | 3 | Domain vehicle 1 | 4 | Domain vehicle 2 | 5 | Domain vehicle 3 | +| 6 | Domain sensor 1 | 7 | Domain sensor 2 | 8 | Domain participant 1 | 9 | Domain participant 2 | 10 | Domain participant 3 | + +**Figure 3 – Typical vehicle domain dynamic map service** + +## 6.4 Variations in vehicle domain services + +### 6.4.1 Basic vehicle domain service functions + +VDS basic functions include collecting and processing traffic and driving information. Generated information services are used to improve recognition of traffic situations and driving behaviour decisions. + +These kinds of generated information provided in virtual map format consist of information about dynamic actors, such as vehicles and participants, and static high-definition road features. This is defined as a VDDM. + +To perform various functions, VDS has multiple services, as follows. + +- Vehicle domain registration: the MV calls DAs to participate in its domain. A DA responds to the MV and exchange credentials. If mutual identification processes are successfully completed, a secure connection shared by the MV and DA is generated. +- Traffic explorer: the MV collects traffic information by communicating with the DAs. The traffic information collected is the synchronized position and other information of the DAs around the MV or information potentially related to the driving behaviour of the MV. +- Traffic reporter: the MV reports the collected local traffic information, obtained by the traffic explorer service, to the other traffic servers, such as a central dynamic map operator or another VD server. It is shared to update the latest status and can be reused in a similar use case of another MV. +- Manoeuvre coordinator: the MV generates its driving manoeuvre plan, it consists of a series of position data with synchronization times. The MV sends it to the relevant DV and request the corresponding plan of the DV. The MV and DV share their driving manoeuvre plan to get agreement or negotiate the coexistence of their plans. If it is successful, the planned driving manoeuvre is performed safely with their mutual understanding. + +### 6.4.2 Vehicle domain registration service + +The MV provides the following VDS. + +| VDS1-003 – Vehicle domain registration service | +|--------------------------------------------------------------------------------------| +| {
The master vehicle should support the vehicle domain registration service.
} | + +Figure 4 shows a typical VD registration service. The MV calls neighbouring vehicles and traffic participants to join a VD. For example, the vehicle in the rear position is able to join the invited VD by registering. If the registration is successful, the vehicle in the rear position joins the VD as a DV. Details of procedures will be provided in the series document. + +If the entity of the sensor is also registered, it joins the VD as a DS. + +![Two diagrams illustrating vehicle domain registration. The top diagram shows a blue 'Master vehicle' and a red 'Domain vehicle' with a 'Domain sensor' inside a dashed circle labeled 'Vehicle domain'. The bottom diagram shows a white 'Master vehicle' and a grey 'Domain vehicle' with a 'Domain sensor' inside a dashed circle, with numbered arrows 1, 2, 3, and 4 pointing to the domain, master vehicle, domain vehicle, and domain sensor respectively.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg) + +F.749.5(21) + +Two diagrams illustrating vehicle domain registration. The top diagram shows a blue 'Master vehicle' and a red 'Domain vehicle' with a 'Domain sensor' inside a dashed circle labeled 'Vehicle domain'. The bottom diagram shows a white 'Master vehicle' and a grey 'Domain vehicle' with a 'Domain sensor' inside a dashed circle, with numbered arrows 1, 2, 3, and 4 pointing to the domain, master vehicle, domain vehicle, and domain sensor respectively. + +##### **Key** + +- 1 Vehicle domain   2 Master vehicle   3 Domain vehicle   4 Domain sensor + +**Figure 4 – Typical vehicle domain registration service** + +The VD has the driving plan of the MV. The driving plan is a kind of driving schedule with a longer period than a driving manoeuvre, such as "turn right at the intersection 1 km away". If the driving plan of a DV differs from that of the VD, the DV exits from the VD and generate its own VD. + +### **6.4.3 Traffic explorer service** + +The MV provides the following VDS. + +| | +|---------------------------------------------------------------------------| +| VDS1-004 – Traffic explorer service | +| {
The master vehicle should support the traffic explorer service.
} | + +Figure 5 shows a typical traffic explorer service. The MV asks DAs for specific parameters (type, dimensions) and measured parameters (position, speed) calibrated with VDS master time. The DA responds to it with synchronized information. The MV creates a VD map. + +![Figure 5 – Typical traffic explorer service diagram. A dashed circle labeled '1' (Vehicle domain) encompasses a road scene. Inside, a '2' (Master vehicle) is at the center. Other elements include: '3' (Domain vehicle 1) on the left, '4' (Domain vehicle 2) on the right, '5' (Domain vehicle 3) at the top left, '6' (Domain vehicle 4) at the bottom right, '7' (Domain sensor 1) on the left, '8' (Domain sensor 2) on the right, '9' (Domain participant 1) as a pedestrian at the top, '10' (Domain participant 2) as a cyclist at the bottom, and '11' (Domain participant 3) as a cyclist on the right. Arrows indicate communication from the master vehicle to various domain participants and sensors. A label 'F.749.5(21)' is in the bottom right corner.](dfe556fea00682b09a59427aaf72051c_img.jpg) + +Figure 5 – Typical traffic explorer service diagram. A dashed circle labeled '1' (Vehicle domain) encompasses a road scene. Inside, a '2' (Master vehicle) is at the center. Other elements include: '3' (Domain vehicle 1) on the left, '4' (Domain vehicle 2) on the right, '5' (Domain vehicle 3) at the top left, '6' (Domain vehicle 4) at the bottom right, '7' (Domain sensor 1) on the left, '8' (Domain sensor 2) on the right, '9' (Domain participant 1) as a pedestrian at the top, '10' (Domain participant 2) as a cyclist at the bottom, and '11' (Domain participant 3) as a cyclist on the right. Arrows indicate communication from the master vehicle to various domain participants and sensors. A label 'F.749.5(21)' is in the bottom right corner. + +##### **Key** + +- | | | | | | | | | +|---|----------------------|----|----------------------|----|----------------------|---|------------------| +| 1 | Vehicle domain | 2 | Master vehicle | 3 | Domain vehicle 1 | 4 | Domain vehicle 2 | +| 5 | Domain vehicle 3 | 6 | Domain vehicle 4 | 7 | Domain sensor 1 | 8 | Domain sensor 2 | +| 9 | Domain participant 1 | 10 | Domain participant 2 | 11 | Domain participant 3 | | | + +**Figure 5 – Typical traffic explorer service** + +In order to generate a VDDM, the MV asks each DA to provide a list of its properties. All property tables with responses to the MV are required to be synchronized to the domain master time provided by the MV. + +As one important procedure of VDDM generation, it is necessary that collected properties be mutually validated. If validation is successful, the property status changes to trustable. + +| | +|--------------------------------------------------------------------------------| +| VDS1-005 – Validation of vehicle domain map | +| {
The master vehicle should validate vehicle domain map to be trusted.
} | + +More detailed procedures will be provided in another document part of the series document set. + +### **6.4.4 Traffic reporter service** + +The MV provides the following VDS. + +| | +|---------------------------------------------------------------------------| +| VDS1-006 – Traffic reporter service | +| {
The master vehicle should support the traffic reporter service.
} | + +Figure 6 shows a typical traffic reporter service. There are multiple MVs driving on the road. MVs create their VDS map information. They report some part of VDS maps to other MVs if foresight information is included. Additionally, they also send the map report created to a central local dynamic map (LDM) server to update it. + +![Figure 6: Typical traffic reporter service diagram. The diagram shows a road with two lanes separated by a dashed line. In the left lane, there is a vehicle labeled '4' (Master vehicle 2) with a circular radar icon, indicating it is sending a report. In the right lane, there is a vehicle labeled '3' (Master vehicle 1). Two dashed circles represent vehicle domains: '2' (Vehicle domain 2) on the left and '1' (Vehicle domain 1) on the right. The label 'F.749.5(21)' is in the bottom right corner.](7f25db95ce3916c0e09803b861a2f7bc_img.jpg) + +Figure 6: Typical traffic reporter service diagram. The diagram shows a road with two lanes separated by a dashed line. In the left lane, there is a vehicle labeled '4' (Master vehicle 2) with a circular radar icon, indicating it is sending a report. In the right lane, there is a vehicle labeled '3' (Master vehicle 1). Two dashed circles represent vehicle domains: '2' (Vehicle domain 2) on the left and '1' (Vehicle domain 1) on the right. The label 'F.749.5(21)' is in the bottom right corner. + +##### **Key** + +1 Vehicle domain 1 2 Vehicle domain 2 3 Master vehicle 1 4 Master vehicle 2 + +**Figure 6 – Typical traffic reporter service** + +Before MV1 builds up VD1, it searches for neighbouring VDs. MV1 finds VD2 and its driving plan matches that of MV1; MV1 joins VD2. If its driving plan differs and it is better to establish VD1, MV1 does so with a different driving plan from VD2. Details of sequences will be defined in subsequent Recommendations in the series. + +Basically, a traffic reporter service has a valid direction and an area for the receiver of the VD. The MV and DAs within the VD are driving forward and never encounter incidents happening at the back of the VD. Also, it is inappropriate for other VDs driving in the opposite direction in the opposing lane to receive the traffic reporter service. + +A vehicle domain service exchanges a lot of messages; restricting communication media access to valid information has a significant effect on efficiency of communication. + +| VDS1-007 – Selected media access of vehicle domain service | +|-------------------------------------------------------------------------------------| +| {
The vehicle domain service should be transmitted only to valid receivers.
} | + +One typical schema for selected access is filtering access control. A couple of schemas will be prepared for VDS message exchange. More detailed procedures will be provided in a subsequent Recommendation in the series. + +NOTE – There exists no contradiction between an extended vehicle service and a traffic reporter of a VDS. Vehicle-to-everything solutions could exist in many ways depending on the requirements of each market. + +### **6.4.5 Manoeuvre coordinator service** + +The MV provides the following VDS. + +| VDS1-008 – Manoeuvre coordinator service | +|--------------------------------------------------------------------------------| +| {
The master vehicle should support the manoeuvre coordinator service.
} | + +Figure 7 shows a typical manoeuvre coordinator service. The MV generates its manoeuvre plan with the VDS master time. DVs respond to it with the synchronized estimated information. + +In general, typical driving processes consist of the recognition, decision and operation stages. The process of recognition of the traffic situation and making the most appropriate and safest driving decisions is named as the preparation stage. For example, if the preparation stage takes 5 s and the following operation stage takes the same time, the MV generates its driving manoeuvre plan starting from its position of 5 s later, which is the end of preparation stage with following positions of 1 s durations, labelled 3 in Figure 7. The MV asks the following DV about its relevant manoeuvre plan. The DV responds with the requested driving manoeuvre plan, labelled 4 in Figure 7. The starting time of each driving manoeuvre plan or U-turn is adjusted, if necessary. + +The whole driving manoeuvre negotiation process requires successful completion within the preparation stage. This indicates that the VDS includes this service and will be implemented with the next generation of communication technology with faster speed, wider traffic bands and lower latency. VDS communication is definitely different from existing broadcast message flow. + +![Figure 7: Typical manoeuvre coordinator service diagram. The diagram shows a road with a dashed line separating lanes. A Master vehicle (1) is in the center lane, moving right. A Domain vehicle (2) is in the right lane, moving right. The Master vehicle's driving manoeuvre plan (3) is shown as a series of dashed rectangles extending into the left lane. The Domain vehicle's driving manoeuvre plan (4) is shown as a series of dashed rectangles extending into the center lane. The diagram is labeled F.749.5(21) in the bottom right corner.](81a4cbf0b3c4cbc065efdf8f800dadde_img.jpg) + +Figure 7: Typical manoeuvre coordinator service diagram. The diagram shows a road with a dashed line separating lanes. A Master vehicle (1) is in the center lane, moving right. A Domain vehicle (2) is in the right lane, moving right. The Master vehicle's driving manoeuvre plan (3) is shown as a series of dashed rectangles extending into the left lane. The Domain vehicle's driving manoeuvre plan (4) is shown as a series of dashed rectangles extending into the center lane. The diagram is labeled F.749.5(21) in the bottom right corner. + +##### **Key** + +1 Master vehicle    2 Domain vehicle    3 Master vehicle's driving manoeuvre plan    4 Domain vehicle's driving manoeuvre plan + +**Figure 7 – Typical manoeuvre coordinator service** + +In some cases, it is necessary for the MV and the DV to arrange their manoeuvre plan. Negotiated plans are authorized by the agent responsible for driving, such as the driver or automated driving manager. Judgement criteria for arrangement necessity, basic manoeuvre priorities, as well as negotiation strategy and authorization sequence requirements lie outside the scope of this Recommendation; they are addressed to other activities. + +### **6.4.6 Scenario variations of vehicle domain service** + +In addition to service types, traffic conditions and road geometry greatly influence a VDS scenario. The following examples show representative service scenarios. Other examples are provided in Appendix I. + +All service scenarios are incorporated into each business use case (BUC), all to be covered as an element of the system use case (SUC). For BUCs and SUCs, see clauses 7 and 9, respectively. + +| VDS1-009 – Service scenarios and business and system use cases | +|-------------------------------------------------------------------------------------------------| +| {
The business use case and system use case element should cover all service scenarios.
} | + +Figure 8 shows a scenario example of a traffic explorer service. The MV is driving on a straight road, it collects relevant information from all nearby actors and generates a VD map. + +![Figure 8: Scenario of traffic explorer on straight road. The diagram shows a road with three lanes. A dashed line separates the lanes. From left to right, the elements are: a car (4) in the left lane, a car (2) with a sensor icon (5) in the middle lane, a car (1) in the middle lane, a person (7) on the right side, a person (8) on a bicycle on the right side, and a car (3) with a sensor icon (6) on the right side. A person (9) is walking on the far right side. The label F.749.5(21) is in the bottom right corner.](5b8a756d9a71c35f17db8bcb90b438a3_img.jpg) + +Figure 8: Scenario of traffic explorer on straight road. The diagram shows a road with three lanes. A dashed line separates the lanes. From left to right, the elements are: a car (4) in the left lane, a car (2) with a sensor icon (5) in the middle lane, a car (1) in the middle lane, a person (7) on the right side, a person (8) on a bicycle on the right side, and a car (3) with a sensor icon (6) on the right side. A person (9) is walking on the far right side. The label F.749.5(21) is in the bottom right corner. + +##### **Key** + +- | | | | | | +|-------------------|------------------------|------------------------|------------------------|-------------------| +| 1 Master vehicle | 2 Domain vehicle 1 | 3 Domain vehicle 2 | 4 Domain vehicle 3 | 5 Domain sensor 1 | +| 6 Domain sensor 2 | 7 Domain participant 1 | 8 Domain participant 2 | 9 Domain participant 3 | | + +**Figure 8 – Scenario of traffic explorer on straight road** + +Figure 9 shows a scenario example of a traffic reporter service. The MVs are driving on a straight road. MV2 generates its VD map, including a red traffic-light signal and relevant traffic status. It is issued as a traffic report to following MVs to communicate the current incoming traffic situation. + +![Figure 9: Scenario of traffic reporter of red signal. The diagram shows a road with three lanes. From left to right, the elements are: a car (11) on the far left, a car (2) with a sensor icon (7) in the middle lane, a car (4) in the middle lane, a person (9) on the right side, a car (6) with a sensor icon (8) on the right side, a person (10) on a bicycle on the right side, and a car (3) on the far right. Three dashed circles represent vehicle domains: Domain 1 (left), Domain 2 (middle), and Domain 3 (right). The label F.749.5(21) is in the bottom right corner.](a24e89a6fe9bb70c83f8bf5202baba95_img.jpg) + +Figure 9: Scenario of traffic reporter of red signal. The diagram shows a road with three lanes. From left to right, the elements are: a car (11) on the far left, a car (2) with a sensor icon (7) in the middle lane, a car (4) in the middle lane, a person (9) on the right side, a car (6) with a sensor icon (8) on the right side, a person (10) on a bicycle on the right side, and a car (3) on the far right. Three dashed circles represent vehicle domains: Domain 1 (left), Domain 2 (middle), and Domain 3 (right). The label F.749.5(21) is in the bottom right corner. + +##### **Key** + +- | | | | | | +|--------------------|-------------------------------------------------|-------------------------------------------------|------------------------------------------------------|-------------------------------------------------------| +| 1 Vehicle domain 1 | 2 Vehicle domain 2 | 3 Vehicle domain 3 | 4 Master vehicle 1 | 5 Master vehicle 2 | +| 6 Master vehicle 3 | 7 Domain sensor 1 (belongs to vehicle domain 2) | 8 Domain sensor 2 (belongs to vehicle domain 3) | 9 Domain participant 1 (belongs to vehicle domain 1) | 10 Domain participant 2 (belongs to vehicle domain 3) | +| 11 Red signal | | | | | + +**Figure 9 – Scenario of traffic reporter of red signal** + +Figure 10 shows a scenario example of a manoeuvre coordinator service. The MV is driving on a straight road, it wants to make right-lane change. It generates a VD map and learns that manoeuvre coordination is necessary with DV1. The MV generates a manoeuvre plan for right-lane change with the VDS master time to coordinate it with DV1. + +![Figure 10: Scenario of manoeuvre coordinator of right lane change. The diagram shows a road with three lanes. A master vehicle (1) is in the center lane, moving right. Domain vehicle 1 (2) is in the right lane, moving right. Domain vehicle 2 (3) is in the left lane, moving right. Driving manoeuvre of master vehicle (4) is shown as a dashed box indicating a right lane change. Driving manoeuvre of domain vehicle 1 (5) is shown as a dashed box indicating a right lane change. Driving manoeuvre of domain vehicle 2 (6) is shown as a dashed box indicating a right lane change. The diagram is labeled F.749.5(21) in the bottom right corner.](e69b9188aa2c14ec6b21c83f711fef65_img.jpg) + +Figure 10: Scenario of manoeuvre coordinator of right lane change. The diagram shows a road with three lanes. A master vehicle (1) is in the center lane, moving right. Domain vehicle 1 (2) is in the right lane, moving right. Domain vehicle 2 (3) is in the left lane, moving right. Driving manoeuvre of master vehicle (4) is shown as a dashed box indicating a right lane change. Driving manoeuvre of domain vehicle 1 (5) is shown as a dashed box indicating a right lane change. Driving manoeuvre of domain vehicle 2 (6) is shown as a dashed box indicating a right lane change. The diagram is labeled F.749.5(21) in the bottom right corner. + +F.749.5(21) + +##### Key + +| | | | | | | | | +|---|---------------------------------------|---|------------------|---|---------------------------------------|---|-------------------------------------| +| 1 | Master vehicle | 2 | Domain vehicle 1 | 3 | Domain vehicle 2 | 4 | Driving manoeuvre of master vehicle | +| 5 | Driving manoeuvre of domain vehicle 1 | | | 6 | Driving manoeuvre of domain vehicle 2 | | | + +**Figure 10 – Scenario of manoeuvre coordinator of right lane change** + +These scenarios include the behaviour by actors with different responsibilities such as sending information, validating received information, following decisions and the driving actions to align to manoeuvres. All behaviours that are required by actors with different responsibilities are authorized and approved by the necessary authorities or actors with different responsibilities. Details of the different responsibilities lie outside the scope of this Recommendation. + +## 6.5 Time synchronization in VDDMS + +The VDS uses calibration of position information by synchronized time. This is applied to both the MV and DAs. The MV generates the VDS master synchronization time. The DAs respond to the MV with their calibrated information by synchronizing to it. + +### VDS1-010 – VDS master time generation + +``` +{ +The master vehicle should generate the VDS master time as the standard time of response information by +the domain actors. +} +``` + +### VDS1-011 – Time synchronization in VDS + +``` +{ +The domain actors should respond to the master vehicle their information calibrated by synchronizing to +the VDS master time sent by the master vehicle. +} +``` + +The vehicle-domain service master time is generated on universal time (UTC) and adjusted by the network time protocol (NTP) defined in [b-IETF RFC 5905] or the precision time protocol (PTP) defined in [b-IEEE 1588]. + +NOTE 1 – The VDS master time is defined in detail in a subsequent Recommendation in the series. + +NOTE 2 – Functional safety has no relation to time synchronization based on the VDS master time. + +## 6.6 Other variations of vehicle domain services + +### 6.6.1 Vehicle domain digital key service + +Providing digital key service, the MV issues various types of digital key message to the customer, one per domain participant (DP). The secure protected and packaged message for the digital key is generated by the MV and sent to the customer. The message is received by the customer with their mobile device, extracted to the functional application of the digital key on the customer's mobile device. The digital key services are only applied to stopped or parked vehicles, they are never activated while the vehicle is driving. + +| | +|-------------------------------------------------------------------------------------------------------| +| VDS1-012 – Vehicle domain digital key service | +| {
The master vehicle may provide vehicle domain digital key services to a domain participant.
} | + +There exist some variations in digital key service according to their objects. General digital key services have different access control of vehicle functions with restricted time durations. Typical variations are as follows. + +- Car-sharing key service: the MV issues the digital key service with full access control of vehicle functions with a restricted time duration linked to car rental or sharing period, such as from 3 days to 1 week. The customer receives the digital key application from the MV, and it will work as the vehicle key device within the car sharing period. It is not necessary for operators to hand over a vehicle key to their customer. +- Valet parking key service: the MV issues the digital key service with access only to the driving function, without private space access such as glove box or trunk room and with a very restricted time duration necessary for driving to a parking area, typically less than 30 min. It is not necessary for the customer to hand over a fully functional vehicle key to valet parking operators. +- Private delivery box key service: the MV issues the digital key service with access only to the vehicle trunk room, there is no driving function with specified time duration negotiated as delivery time of luggage delivery. The delivery service operator receives a private delivery-box key from the MV and is enabled access to its trunk room as a private delivery box. + +Figure 11 shows a typical VD digital key service. The MV stops in a public or private, permanent or temporary parking area and communicates with the mobile device belonging to the DP. + +![Diagram of a vehicle domain digital key service. A car (2) is centered in a rectangular parking lot (4). A large dashed circle (1) centered on the car represents the vehicle domain. A person icon (3) representing the domain participant is inside the domain and the parking lot. An arrow points from the car to the edge of the domain circle.](844077b3034f0030b404207db0ad76b4_img.jpg) + +``` +graph TD + subgraph 4 [Parking lot] + subgraph 1 [Vehicle domain] + 2[Master vehicle] -- communication --> 3[Domain participant] + end + end +``` + +Diagram of a vehicle domain digital key service. A car (2) is centered in a rectangular parking lot (4). A large dashed circle (1) centered on the car represents the vehicle domain. A person icon (3) representing the domain participant is inside the domain and the parking lot. An arrow points from the car to the edge of the domain circle. + +F.749.5(21) + +- Key** +- 1 Vehicle domain   2 Master vehicle   3 Domain participant   4 Parking lot + +**Figure 11 – Typical vehicle domain digital key service** + +## 6.7 System architecture of vehicle domain services + +### 6.7.1 General + +This clause specifies the system architecture of the VDS. The main functions of the VDS are implemented in the MV; it cooperates with the DAs on the connection link between domain master and actors. The functions introduced are higher layer ones and they do not restrict physical controllers or the component structure implemented in a vehicle. + +### 6.7.2 Basic system architecture of vehicle domain service + +The VD system is one network subsystem generated by the MV. It consists of the MV, DAs and connecting service-link channel. The implemented functions of the domain master and actors are provided by the VDS and the vehicle domain actor (VDA) applications. Each application interface is connected to the service-link channel via each side of the service-link controllers. The service link-controller provides a connecting interface for all communication layers, messages, data formats and other schemas. Figure 12 shows a logical model example of the basic system architecture of the VDS. + +![Figure 12: Basic system architecture of VDS. The diagram shows a logical model of the VDS. On the left, a box labeled '6' (Vehicle domain actor) contains a box labeled '4' (Vehicle domain actor application), which in turn contains a box labeled '2' (Domain actor service link controller). On the right, a box labeled '5' (Vehicle domain server) contains a box labeled '3' (Vehicle domain service application), which in turn contains a box labeled '1' (Domain master service link controller). A horizontal bar labeled '8' (Service link channel) connects the '2' and '1' controllers. The entire right-side structure is enclosed in a car-shaped outline labeled '7' (Master vehicle). The label 'F.749.5(21)' is at the bottom right.](7e1c9b51e067a48cd0fcc9748d8bd8d8_img.jpg) + +Figure 12: Basic system architecture of VDS. The diagram shows a logical model of the VDS. On the left, a box labeled '6' (Vehicle domain actor) contains a box labeled '4' (Vehicle domain actor application), which in turn contains a box labeled '2' (Domain actor service link controller). On the right, a box labeled '5' (Vehicle domain server) contains a box labeled '3' (Vehicle domain service application), which in turn contains a box labeled '1' (Domain master service link controller). A horizontal bar labeled '8' (Service link channel) connects the '2' and '1' controllers. The entire right-side structure is enclosed in a car-shaped outline labeled '7' (Master vehicle). The label 'F.749.5(21)' is at the bottom right. + +##### Key + +- | | | | | +|---|---------------------------------------|---|--------------------------------------| +| 1 | Domain master service link controller | 2 | Domain actor service link controller | +| 3 | Vehicle domain service application | 4 | Vehicle domain actor application | +| 5 | Vehicle domain server | 6 | Vehicle domain actor | +| 7 | Master vehicle | 8 | Service link channel | + +NOTE – This figure illustrates the representative domain actor group. A vehicle domain actor can consist of vehicles, sensors and participants. + +**Figure 12 – Basic system architecture of VDS** + +| VDS1-013 – Basic system architecture of vehicle domain service | +|----------------------------------------------------------------------------------------------------------------------------------------------| +| {
The master vehicle should communicate with the domain actors by service-link channel via each side of the service link controller.
} | + +NOTE 1 – The scope of this document is the definition of the VDS application implemented in a vehicle. + +NOTE 2 – This document only focuses on that definition. The logical architecture model of the VDS does not lead to any constraint in relation to the vehicle electronic architecture design and that does not interfere with the OEM responsibility in that area. + +### 6.7.3 Typical system architecture variation of vehicle domain service + +The VDS application communicates with the service link channel via the service link controller. The life cycle of the vehicle is longer than the lifetime of communication technologies in general, so if the VDS is selected for implementation by manufacturers, the server application, functions and technologies are recommended for preparation for future updates. The server application will be changed by software updates. Some communication generation technologies will be changed by a controller replacement, which means the service-link controller of the domain master is designed to + +be connected to a VDS unit with a general connecting bus and to be easily replaced. Figure 13 shows a typical system architecture variation of the VDS prepared for future update. + +![Figure 13: Typical system architecture of VDS for future update. The diagram shows a 'Master vehicle' (7) containing a 'Vehicle domain actor' (6) and a 'Vehicle domain server' (5). The 'Vehicle domain actor' (6) contains a 'Domain actor service link controller' (2) and a 'Vehicle domain actor application' (4). The 'Vehicle domain server' (5) contains a 'Vehicle domain service application' (3). A 'Domain master service link controller' (1) is connected to the 'Domain actor service link controller' (2) via a 'Service link channel' (8).](a74294f34a0c736b7ee0f5f0cdca7e28_img.jpg) + +Figure 13: Typical system architecture of VDS for future update. The diagram shows a 'Master vehicle' (7) containing a 'Vehicle domain actor' (6) and a 'Vehicle domain server' (5). The 'Vehicle domain actor' (6) contains a 'Domain actor service link controller' (2) and a 'Vehicle domain actor application' (4). The 'Vehicle domain server' (5) contains a 'Vehicle domain service application' (3). A 'Domain master service link controller' (1) is connected to the 'Domain actor service link controller' (2) via a 'Service link channel' (8). + +F.749.5(21) + +##### **Key** + +- | | | | | +|---|---------------------------------------|---|--------------------------------------| +| 1 | Domain master service link controller | 2 | Domain actor service link controller | +| 3 | Vehicle domain service application | 4 | Vehicle domain actor application | +| 5 | Vehicle domain server | 6 | Vehicle domain actor | +| 7 | Master vehicle | 8 | Service link channel | + +NOTE – This figure illustrates the representative domain actor group. A vehicle domain actor can consist of vehicles, sensors and participants. + +**Figure 13 – Typical system architecture of VDS for future update** + +| | +|-------------------------------------------------------------------------------------------------------------------| +| VDS1-014 – Typical system architecture of VDS for future update | +| {
The service link controller of the VDS should be designed to be easily replaced for the future updates.
} | + +The updates in this policy will cover a variety of possible aspects, including functional, software and security. + +The domain master or DA service-link controller implemented in the vehicle is required to prepare for future updates. Other DA service link controllers are required to prepare for future updates, if necessary. In general, DA service link controllers for DPs have almost the same lifetime as their communication technology, so it is not required to prepare for future updates. + +### **6.7.4 Vehicle domain service on a vehicle multimedia service** + +The VDS application communicates with the VDA application via the service-link channel and service-link controllers. These communications belong to the outside communication category group, and these are the main scope of the VDS. + +On the other hand, the VDS outputs some information via the human/machine interface (HMI) for the vehicle driver. The contents of the information depend on the VDS provided. The information flow between the HMI and vehicle driver is implemented under OEM responsibility. If the OEM selected implementation of the VDS at level 4 [b-SAE] or a higher-level automated driving system, that information flow consists of both visual moving pictures and acoustic sound, real time and bidirectional, free from driver distraction. + +The original output between VDS and a vehicle multimedia service (VMS) is based on messages on the internal communication. Those bidirectional digital messages are translated in the VMS to interact with the vehicle driver. Figure 14 shows a typical system architecture of the VDS connected to the VMS. + +![Figure 14: Vehicle domain service on vehicle multimedia service. The diagram shows a vehicle (7) containing a vehicle domain server (5), a vehicle domain actor (6), and a vehicle domain service application (3). A service link channel (8) connects the vehicle domain actor (6) to the vehicle domain service application (3). The vehicle domain actor (6) is connected to the vehicle domain server (5). The vehicle domain server (5) is connected to the vehicle multimedia service (9).](cbdfdade780e677eb1c1aef3081ce9ef_img.jpg) + +F.749.5(21) + +Figure 14: Vehicle domain service on vehicle multimedia service. The diagram shows a vehicle (7) containing a vehicle domain server (5), a vehicle domain actor (6), and a vehicle domain service application (3). A service link channel (8) connects the vehicle domain actor (6) to the vehicle domain service application (3). The vehicle domain actor (6) is connected to the vehicle domain server (5). The vehicle domain server (5) is connected to the vehicle multimedia service (9). + +##### **Key** + +- | | | +|-----------------------------------------|----------------------------------------| +| 1 Domain master service link controller | 2 Domain actor service link controller | +| 3 Vehicle domain service application | 4 Vehicle domain actor application | +| 5 Vehicle domain server | 6 Vehicle domain actor | +| 7 Master vehicle | 8 Service link channel | +| | 9 Vehicle multimedia service | + +NOTE – This figure illustrates the representative domain actor group. A vehicle domain actor can consist of vehicles, sensors and participants. + +**Figure 14 – Vehicle domain service on vehicle multimedia service** + +The design of the HMI for drivers is clearly under the responsibility of the manufacturer. Figure 14 only provides a typical logical example model of internal connection between the VDS and VMS. + +| VDS1-015 – Vehicle domain service on vehicle multimedia service | +|--------------------------------------------------------------------------------------------------------------------------------------------| +| 
{ The vehicle domain service may provide various information to the driver via the vehicle multimedia service in the vehicle. }
| + +NOTE – The domain sensor connection is a kind of vehicle multimedia service outside the vehicle. + +A more detailed reference model between VDS and VMS is available in Appendix III. + +## 6.8 Network operators related to VDS + +The VDS requires some information support by various operators in the smart city traffic network. They gather relevant information reported by the VDS or other data collecting services, process them applying local regulation or optimizing policy and issue updated requests to the local network subsystems. These service operators outside of the VDS are classed as secondary actors. The MV and DAs inside the VDS are classed as primary actors (PAs). Typical examples of these operators are the following. + +- Traffic operator: the traffic operation server generates traffic control rules in order to optimize traffic density and the length of traffic jams. Their controllable traffic rules are the setting of the priority lane and accessible area, timing of traffic signal and so on. +- Traffic monitor (TM): the TM server covers the middle range area in the network directory domain and geographical position in the city and gathers local traffic information reported by neighbouring VDSs. It issues a summary report to the central local dynamic server in order to refresh the latest situation. At the same time, it issues some attention or warning report to PAs. It gathers relevant information from the VDS or other system, validates the situation with some rules and policies to generate and issue official reports. +- User information server: the secured user accounts and relevant information database server covers the central control of the city and smart city traffic network system. General access to fully separated personal information is strictly restricted. It is allowed only to the super account of government level, used to identify user specific information by public unsigned information of the VDS. + +It is possible to implement other operation servers in the smart city traffic services. + +| VDS1-016 – Network operators and VDS | +|-------------------------------------------------------------------------------------------------------------------------------------------| +| {
The master vehicle should communicate and cooperate with various network operators in order to provide vehicle domain services.
} | + +The implementation of the VDS depends on an OEM decision. The customer decides on activation of the VDS function for each vehicle. The customer who wants to activate the VDS function selects whether information about the vehicle is sent to some network operators with the reception of additional benefits of services provided by them. + +Whether or not the customer selects that relevant information is sent, all communications of the VDS are guaranteed to be performed via a connection that is secure enough. The details of secure schemes will be provided in subsequent Recommendations in the series. + +## 6.9 VDS in smart traffic architecture model proposal + +Information processing of the general smart traffic is implemented by a multi-layer-like infrastructure. Information is collected in a home, a street, a town, a city, a state and in a country for the geographic expanse and is bundled up. Various types of traffic classifications exist in the information group of each area, such as customer usage, commercial service, business functionality, public transport and central information manager that are mixed and act according to an individual rule of every group and form an overall traffic transport. + +The infrastructure of smart traffic is implemented in a multi-layer form in order to process complicated multi-layered traffic information functionally and effectively. Therefore, the use is recommended of the figure of two-dimensional placement that constitutes an area and a function as both axes if modelling these information processes and defining use cases for further standardization by a general systematic approach. This technique is already applied to smart grid electricity transfer networks and is well known as a successful example of the systematic approach for standardization activities. + +Figure 15 shows a typical example of a smart traffic architecture model proposal (STAMP) that plots a horizontal axis of area with a vertical axis of function. The classification summary of both axes is as follows. + +Vertical axis: + +- home: processing of information about traffic to the home or the area around the home; +- town/street: processing of information about traffic in the town or street area; +- city: processing of information about traffic in a city area; +- state: processing of information about traffic in a state or area containing multiple cities; +- country: processing of information about traffic in a country area. + +Horizontal axis: + +- customer travel: processing of information about traffic involving customer usage of vehicles such as personal driving; +- commercial/consumer travel: processing of information about traffic involving commercial services such as taxi or car sharing; +- business transportation: processing of information about traffic for commercial objectives such as logistics, transport or delivery to home; +- public transportation: processing of information about traffic for public transport such as bus or train; + +- traffic management: processing of information about traffic control such as traffic monitoring. + +The conventional infrastructure information model focuses only on the contents and not the structure of information, so that it only provides a simple and individual one-dimensional model. In a systematic approach, a hierarchical function of the smart traffic information processing is generalized by modelling the infrastructure implementation to define functions and processes of traffic information for further standardization. + +![Figure 15 – Smart traffic architecture model proposal. A grid diagram showing the relationship between vertical axes (Area, Country, State/intercity, City, Town/street, Home) and horizontal axes (Function, Traffic management, Public transport, Business transport, Commercial/consumer travel, Customer travel). Smart traffic entities (Vehicle domain service, Smart city traffic manager, Traffic control operator, Traffic monitor operator) are mapped to specific grid cells.](b235edb1dbe659e2782c9a0e47775ca4_img.jpg) + +| | | | | | | +|-------|----|---|----|----|----| +| 1 \ 7 | 8 | 9 | 10 | 11 | 12 | +| 2 | | | | | | +| 3 | 14 | | | | | +| 4 | 15 | | | | | +| 5 | 16 | | | | | +| 6 | | | | | | + +Entity 13 (Vehicle domain service) is a large box spanning columns 8-12 and rows 4-5. Entity 14 (Smart city traffic manager) is in row 3, column 8. Entity 15 (Traffic control operator) is in row 4, column 8. Entity 16 (Traffic monitor operator) is in row 5, column 8. Arrows indicate relationships between 14, 15, 16, and 13. + +Figure 15 – Smart traffic architecture model proposal. A grid diagram showing the relationship between vertical axes (Area, Country, State/intercity, City, Town/street, Home) and horizontal axes (Function, Traffic management, Public transport, Business transport, Commercial/consumer travel, Customer travel). Smart traffic entities (Vehicle domain service, Smart city traffic manager, Traffic control operator, Traffic monitor operator) are mapped to specific grid cells. + +F.749.5(21) + +#### **Key** + +#### **Vertical axis** + +| | | | +|--------|---------------|-------------------| +| 1 Area | 2 Country | 3 State/intercity | +| 4 City | 5 Town/street | 6 Home | + +#### **Horizontal axis** + +| | | | +|-----------------------|-------------------------------|--------------------| +| 7 Function | 8 Traffic management | 9 Public transport | +| 10 Business transport | 11 Commercial/consumer travel | 12 Customer travel | + +#### **Smart traffic entities** + +| | | +|-----------------------------|-------------------------------| +| 13 Vehicle domain service | 14 Smart city traffic manager | +| 15 Traffic control operator | 16 Traffic monitor operator | + +**Figure 15 – Smart traffic architecture model proposal** + +Additional examples of a STAMP are provided in Appendix II. + +The development of such a logical traffic information model lies outside the scope of this document. It is introduced in order to derive recommended implementation policy for the VDS. + +The VDS is allocated in STAMP as a low-end model of smart traffic information process. It indicates that the VDS implemented in vehicles belonging to different business domains such as consumer car, taxi, logistic truck and public transporter, will have unique communication interfaces. + +| | +|-------------------------------------------------------------------------------------------------------------| +| VDS1-017 – VDS in STAMP | +| {
The VDS should be defined to have unique communication interface for the relevant parts in STAMP.
} | + +Detailed specifications of the VDS unified communication interface will be provided in subsequent Recommendations in the series. + +## **6.10 Information security in VDS** + +The VDS is specified with a couple of security schemata in order to ensure security and the safety of the information handled. The basic policy of VDS security is the following. + +- VDS identification: before setting up a secure connection between the MV and the DA, the vehicle domain service account (VDSA) of the DA is evaluated and correctly accepted. +- Communication with ensured secure connection: the communication link applied to the VDS uses a secure schema with encryption of sufficient strength such as transport layer security (TLS), data encryption and other security methods. +- Fully separate public unsigned data from personal information: private specific data that directly enables identification of customer personal information is never included in VDS communication. Only the unsigned public property of the MV and actors is exchanged and gathered. Personal information is stored in a specific customer data base server, which can only be accessed by some restricted accounts. + +A detailed security schema for VDS communication will be provided in subsequent Recommendations in the series. + +| | +|-------------------------------------------------------------------------------------------------------------------------------| +| VDS1-018 – VDS security | +| {
The communication channel of the VDS communication should be performed with a secure connection of enough strength.
} | + +| | +|---------------------------------------------------------------------------------------------------------------------| +| VDS1-019 – Unsigned data policy of VDS | +| {
All the data contents exchanged by the VDS communication should only include unsigned public information.
} | + +NOTE 1 – Some vehicle identifiers (IDs) or actor IDs included in VDS that indirectly link to personal information are transformed to public unsigned information, which hides its indirect link from each actor. + +NOTE 2 – The vehicle identification number (VIN), is the most used vehicle ID and it is applied to many existing vehicles and applications, A VIN is considered as a direct link to personal information, so is never included in VDS messages. + +# 7 Business use cases for VDS + +## 7.1 General + +This clause gives the basic definitions of BUC s for VDSs. + +In clause 6.4, some domain services provided by the MV are defined. + +## 7.2 Business use case of vehicle domain registration + +The MV establishes its VD and invites DAs. DAs join the VD with an authentication provided by the MV. The MV and DA establish a secure connection before starting other services. + +| | +|------------------------------------------------------------------------------------------------------------------------| +| VDS1-020 – BUC of vehicle domain registration | +| {
The master vehicle should provide the vehicle domain registration function of the VDS as defined in Table 1.
} | + +**Table 1 – Business use case of vehicle domain registration** + +| No. | Type | Description | +|-----|--------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Type of use case | Business UC | +| 2 | Use case ID – name | VDS-BUC-001 – Vehicle domain registration | +| 3 | Objectives | The master vehicle will accept the participation of domain actor in its VD. | +| 4 | Description | 1) The master vehicle calls the domain actor to join its domain network service.
2) The domain actor will respond to the master vehicle and they will exchange credentials to validate each VDSA.
3) If authentication is successfully completed, the master vehicle and domain actor will establish secure connection. | +| 5 | Prerequisites | – The master vehicle is equipped with a VDS server.
– The domain actors are equipped with VDS clients.
– The master and actors communicate with each other through the VDS. | +| 6 | Operations | – The master vehicle sets up the vehicle domain service system (VDSS).
– The master vehicle provides the VDS. | +| 7 | End conditions | – The master vehicle successfully initiates the VDS. | + +## 7.3 Business use case of traffic explorer + +The MV gathers information from surrounding actors in order to acquire a traffic map and check its driving plan and manoeuvres. The MV sets up a VD as the MV, establishes communication links with participating DAs and exchanges relevant messages. + +| | +|-------------------------------------------------------------------------------------------------------------| +| VDS1-021 – BUC of traffic explorer | +| {
The master vehicle should provide the traffic explorer function of the VDS as defined in Table 2.
} | + +**Table 2 – Business use case of traffic explorer** + +| No. | Type | Description | +|-----|--------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Type of use case | Business UC | +| 2 | Use case ID – name | VDS-BUC-002 – Traffic explorer | +| 3 | Objectives | The master vehicle acquires a complete map about the vehicle domain actors. | +| 4 | Description | 1) The master vehicle establishes a VD.
2) The master vehicle requests map information from domain actors.
3) The domain actors respond to the master vehicle with the requested information.
4) The master vehicle validates the received responses to generate map information.
5) The master vehicle closes the VDS service and communication link. | +| 5 | Prerequisites | – The master vehicle is equipped with a VDS server.
– The domain actors are equipped with VDS clients.
– The master and actors communicate with each other through the VDS. | + +**Table 2 – Business use case of traffic explorer** + +| No. | Type | Description | +|-----|----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 6 | Operations |
  • – The master vehicle sets up the VDSS.
  • – The master vehicle provides the VDS.
  • – The master vehicle generates the VDDM.
| +| 7 | End conditions |
  • – The master vehicle successfully completes the VDDM.
| + +## **7.4 Business use case of traffic reporter** + +The MV reports the acquired VD map to the other operators. One destination is the smart-city traffic manager (SCTM) in order to update the central LDM database. The other destinations surround other VDS MVs in order to reuse the original VDS map information as the shared map or the basis of an updated map. + +| VDS1-022 – BUC of traffic reporter | +|-------------------------------------------------------------------------------------------------------------| +| {
The master vehicle should provide the traffic explorer function of the VDS as defined in Table 3.
} | + +**Table 3 – Business use case of traffic reporter** + +| No. | Type | Description | +|-----|--------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Type of use case | Business UC | +| 2 | Use case ID – name | VDS-BUC-003 – Traffic reporter | +| 3 | Objectives | The master vehicle issues the traffic report. | +| 4 | Description |
  1. 1) The master vehicle establishes a VD.
  2. 2) The master vehicle requests map information from domain actors.
  3. 3) The domain actors respond to the master vehicle with the requested information.
  4. 4) The master vehicle validates the received responses to generate map information.
  5. 5) The master vehicle issues the generated traffic status report.
  6. 6) The master vehicle closes the VDS service and communication link.
| +| 5 | Prerequisites |
  • – The master vehicle is equipped with a VDS server.
  • – The domain actors are equipped with VDS clients.
  • – The master and actors communicate with each other through the VDS.
| +| 6 | Operations |
  • – The master vehicle sets up the VDSS.
  • – The master vehicle provides the VDS.
  • – The master vehicle generates the VDDM.
  • – The master vehicle issues the traffic status report.
| +| 7 | End conditions |
  • – The master vehicle successfully issues the traffic report.
| + +## **7.5 Business use case of manoeuvre coordinator** + +The MV plans to perform some driving manoeuvres, such as start, acceleration, deceleration, stop, right/left turn or right/left lane change. + +According to the result of analysis based on acquired traffic status, the next driving manoeuvre plan will be made. Sometimes it is necessary for other relevant DAs to agree or to negotiate with their driving plans. So, the MV asks the other DAs for a driving plan to reach an agreement or negotiation. + +| | +|------------------------------------------------------------------------------------------------------------------| +| VDS1-023 – BUC of manoeuvre coordinator | +| {
The master vehicle should provide the manoeuvre coordinator function of the VDS as defined in Table 4.
} | + +**Table 4 – Business use case of manoeuvre coordinator** + +| No. | Type | Description | +|------------|--------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Type of use case | Business UC | +| 2 | Use case ID – name | VDS-BUC-004 – Manoeuvre coordinator | +| 3 | Objectives | The master vehicle makes agreement about its driving manoeuvre with other VDS entities. | +| 4 | Description | 1) The master vehicle establishes a VD.
2) The master vehicle generates its driving manoeuvre plan.
3) The master vehicle asks to other VDS entities with the generated driving plan.
4) The domain actors respond to the master vehicle with their response to the proposed manoeuvre plan.
5) The master vehicle validates the received responses to negotiate with the manoeuvre plan.
6) The master vehicle closes the VDS service and communication link. | +| 5 | Prerequisites | – The master vehicle is equipped with a VDS server.
– The domain actors are equipped with VDS clients.
– The master and actors communicate with each other through the VDS. | +| 6 | Operations | – The master vehicle sets up the VDSS.
– The master vehicle provides the VDS.
– The master vehicle generates the VDDM.
– The master vehicle agrees with domain vehicles about driving manoeuvre. | +| 7 | End conditions | – The master vehicle successfully completes the driving manoeuvre plan. | + +# 8 System sequences for VDS + +## 8.1 General + +This clause gives the SUC sequence by the method of detailing, dividing and classifying the process of BUCs. General texts divided and classified as the communication steps of a BUC are defined as SUCs, and are defined in clause 8.2. + +Implementations of each SUC are specified in subsequent Recommendations in the series. + +## 8.2 Basic elements of a general BUC + +A typical BUC consists of following communication steps: + +- VDS start: user or vehicle driving manager initiates VDS service with some triggers that consist of additional conditions; +- communication set up: the MV establishes a communication link with DAs; +- security set up: the MV establishes a secure communication link with DAs; +- VDS selection: the MV informs of the selected VD service to the DAs; +- VD data collection: the MV requests the relevant information of the DAs; + +- VD status report: the MV issues the generated VDS information report to other VDS entities; +- driving manoeuvre query: the MV asks other DAs whether they accept the planned driving manoeuvre proposed by the MV; +- VDS stop: the MV terminates the VD service and informs the DAs of it. + +The first four and the last elements are common and mandatory for all VDS implementations. Alternative selection from the fifth to seventh elements gives variations in the VDS. + +Table 5 shows the basic elements of VDS BUCs. + +**Table 5 – Basic elements of the VDS business use cases** + +| | +|----------------------------------| +| vehicle domain service start | +| communication set up | +| security set up | +| vehicle domain service selection | +| vehicle domain data collection | +| vehicle domain status report | +| driving manoeuvre query | +| vehicle domain service stop | + +| | +|-----------------------------------------------------------------------------------------------------------------------------------------------| +| VDS1-024 – Basic elements of VDS business use cases | +| {
The master vehicle should build up the VD service by integrating the basic elements of business use cases as defined in clause 8.2.
} | + +More details of these use case elements are described in Clause 9. + +# 9 System use cases for VDS + +## 9.1 General + +This clause provides the basic definitions of SUCs for each BUC. + +Fully detailed message form, data content definitions and application sequences are defined in subsequent Recommendations in the series. + +## 9.2 System use case of VDS start + +The user or a driving management controller uses the VDS to collect traffic information around the MV. A switch or other alternative trigger condition starts VD services. + +| | +|-------------------------------------------------------------------------------------------------| +| VDS1-025 – SUC of VDS start | +| {
The master vehicle should perform the VDS start of SUC for VDS as defined in Table 6.
} | + +**Table 6 – System use case of VDS start** + +| No. | Type | Description | +|-----|--------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Type of use case | System UC | +| 2 | Use case ID – name | VDS-SUC-001 – VDS start | +| 3 | Objectives | The user or driving management system in the master vehicle initiates VD services. | +| 4 | Description | 1) The user operates some driving interface to initiate VD services.
2) The alternative driving management system in the master vehicle initiates VD services. | +| 5 | Prerequisites | – The master vehicle drives with no malfunctions.
– Some of the domain actors exist around the master vehicle. | +| 6 | Operations | – The user will initiate VD services by user operation.
– The driving management system will initiate VD services by some trigger conditions. | +| 7 | End conditions | – The master vehicle successfully initiated the VD services. | + +## 9.3 System use case of communication set up + +The MV generates a VD network. Relevant traffic participants, such as vehicles, bikes and walkers join that network as DAs. The MV provides VDSs to the actors participating in the domain service network. + +| VDS1-026 – SUC of communication set up | +|----------------------------------------------------------------------------------------------------------------| +| {
The master vehicle should perform the communication set up of SUC for the VDS as defined in Table 7.
} | + +**Table 7 – System use case of communication set up** + +| No. | Type | Description | +|-----|--------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Type of use case | System UC | +| 2 | Use case ID – name | VDS-SUC-002 – Communication set up | +| 3 | Objectives | The master vehicle establishes a communication link with other VDS entities. | +| 4 | Description | 1) The master vehicle sends a connection request to other VDS entities.
2) The domain actors respond to the master vehicle.
3) The communication links between the master vehicle and domain actors are established. | +| 5 | Prerequisites | – VDS start process was successfully finished.
– The master vehicle is ready to perform the communication set up process.
– The domain actors are also ready to perform the communication set up process. | +| 6 | Operations | – The master vehicle is equipped with a communication set up function.
– The domain actors are equipped with a communication set up function. | +| 7 | End conditions | – The master vehicle successfully established the communication link with domain actors. | + +## 9.4 System use case of security set up + +The MV establishes a secure communication link on the established communication link. It is a mutual encryption schema using a certificate. Details of the security schema are defined in subsequent Recommendations in the series. + +| | +|-------------------------------------------------------------------------------------------------------| +| VDS1-027 – SUC of security set up | +| {
The master vehicle should perform the security set up of SUC for VDS as defined in Table 8.
} | + +**Table 8 – System use case of security set up** + +| No. | Type | Description | +|-----|--------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Type of use case | System UC | +| 2 | Use case ID – name | VDS-SUC-003 – Security set up | +| 3 | Objectives | The master vehicle establishes secure communication link with other VDS entities. | +| 4 | Description | 1) The master vehicle sends secure connection request to other VDS entities.
2) The domain actors respond to the master vehicle.
3) The secure communication links between the master vehicle and domain actors are established. | +| 5 | Prerequisites | – VDS communication link was successfully established.
– The master vehicle is ready to perform security set up process.
– The domain actors are also ready to perform security set up process. | +| 6 | Operations | – The master vehicle is equipped with security set up function.
– The domain actors are equipped with security set up function. | +| 7 | End conditions | – The master vehicle successfully established the secure communication link with domain actors. | + +## 9.5 System use case of VDS selection + +The MV selects the applied VD service. Other DAs are informed and it is agreed with them as the selected VDS function. + +| | +|-------------------------------------------------------------------------------------------------------| +| VDS1-028 – SUC of VDS selection | +| {
The master vehicle should perform a VDS selection of SUC for the VDS as defined in Table 9.
} | + +**Table 9 – System use case of VDS selection** + +| No. | Type | Description | +|-----|--------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Type of use case | System UC | +| 2 | Use case ID – name | VDS-SUC-004 – VDS selection | +| 3 | Objectives | The master vehicle selects the applied VD service. | +| 4 | Description | 1) The master vehicle sends the VDS selection request to other VDS entities.
2) The domain actors respond to the master vehicle.
3) The VDS selection is agreed. | + +**Table 9 – System use case of VDS selection** + +| No. | Type | Description | +|-----|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 5 | Prerequisites |
  • – Security set up process was successfully finished.
  • – The master vehicle is ready to perform the VDS selection process.
  • – The domain actors are also ready to perform the VDS selection process.
| +| 6 | Operations |
  • – The master vehicle is equipped with a VDS selection function.
  • – The domain actors are equipped with a VDS selection function.
| +| 7 | End conditions |
  • – The master vehicle successfully performs the VDS selection process.
| + +## 9.6 System use case of VD data collection + +The MV gathers relevant information about the DAs participating in its service domain. The MV requests some information synchronized to pointed standard timing. + +| | +|------------------------------------------------------------------------------------------------------------| +| VDS1-029 – SUC of VD data collection | +| {
The master vehicle should perform the VD data collection SUC for the VDS as defined in Table 10.
} | + +**Table 10 – System use case of VD data collection** + +| No. | Type | Description | +|-----|--------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Type of use case | System UC | +| 2 | Use case ID – name | VDS-SUC-005 – VD data collection | +| 3 | Objectives | The master vehicle gathers the VD data from other VDS entities. | +| 4 | Description |
  1. 1) The master vehicle sends a VD data collection request to other VDS entities.
  2. 2) The domain actors respond to the master vehicle.
  3. 3) The VD data collection is completed by receiving all the responses from the domain actors.
| +| 5 | Prerequisites |
  • – VD selection process was successfully finished.
  • – The master vehicle is ready to perform the VD data collection process.
  • – The domain actors are also ready to perform the VD data collection process.
| +| 6 | Operations |
  • – The master vehicle is equipped with a VD data collection function.
  • – The domain actors are equipped with a VD data collection function.
| +| 7 | End conditions |
  • – The master vehicle successfully completed the VD data collection from the domain actors.
| + +## 9.7 System use case of VD status report + +The MV generates a VD status report. This report is sent to the SCTM in order to refresh the central LDM, and it will also be sent to surrounding VDS entities in order to reuse the basis of VD map information. + +| | +|------------------------------------------------------------------------------------------------------------| +| VDS1-030 – SUC of VD status report | +| {
The master vehicle should generate a VD status report of SUC for the VDS as defined in Table 11.
} | + +**Table 11 – System use case of VD status report** + +| No. | Type | Description | +|-----|--------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Type of use case | System UC | +| 2 | Use case ID – name | VDS-SUC-006 – VD status report | +| 3 | Objectives | The master vehicle issues the traffic status report to other VDS entities. | +| 4 | Description | 1) The master vehicle generates the traffic report based on the collected VDS information.
2) The master vehicle issues the traffic status report to other VDS entities.
3) Another master vehicle reuses this report as the basis of another VDS data collection. | +| 5 | Prerequisites | – VD selection process was successfully finished.
– The master vehicle is ready to perform the VD status report process.
– The domain actors are also ready to perform the VD status report process. | +| 6 | Operations | – The master vehicle is equipped with a VD status report function.
– The domain actors are equipped with a VD status report function. | +| 7 | End conditions | – The master vehicle successfully issued the VD status report to other VDS entities. | + +## 9.8 System use case of driving manoeuvre query + +The MV generates a driving manoeuvre plan. This plan should be accepted and negotiated with other DAs. The agreed manoeuvre plan is then sent to other VDS entities. + +| | +|---------------------------------------------------------------------------------------------------------------| +| VDS1-031 – SUC of driving manoeuvre query | +| {
The master vehicle should send a driving manoeuvre query of SUC for the VDS as defined in Table 12.
} | + +**Table 12 – System use case of driving manoeuvre query** + +| No. | Type | Description | +|-----|--------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Type of use case | System UC | +| 2 | Use case ID – name | VDS-SUC-007 – driving manoeuvre query | +| 3 | Objectives | The master vehicle establishes a communication link with the other VDS entities. | +| 4 | Description | 1) The master vehicle sends the planned driving manoeuvre to the other VDS entities.
2) The domain actors respond to the master vehicle.
3) The planned driving manoeuvre of the master vehicle is agreed or negotiated with the other VDS entities. | +| 5 | Prerequisites | – VD selection process was successfully finished.
– The master vehicle is ready to perform the driving manoeuvre query process.
– The domain actors are also ready to perform the driving manoeuvre query process. | +| 6 | Operations | – The master vehicle is equipped with a driving manoeuvre query function.
– The domain actors are equipped with a driving manoeuvre query function. | + +**Table 12 – System use case of driving manoeuvre query** + +| No. | Type | Description | +|-----|----------------|------------------------------------------------------------------------------------------------------| +| 7 | End conditions | – The master vehicle successfully negotiated its driving manoeuvre plan with the other VDS entities. | + +## **9.9 System use case of VDS stop** + +The MV terminates the VD services. The other VDS entities are informed before the MV stops the VD services. The service is stopped, and security and communication links are terminated. + +| | +|-----------------------------------------------------------------------------------------------------| +| VDS1-032 – SUC of VDS stop | +| {
The master vehicle should perform the VDS stop of SUC for the VDS as defined in Table 13.
} | + +**Table 13 – System use case of VDS stop** + +| No. | Type | Description | +|-----|--------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Type of use case | System UC | +| 2 | Use case ID – name | VDS-SUC-008 – VDS stop | +| 3 | Objectives | The master vehicle terminates the VD services. | +| 4 | Description | 1) The master vehicle terminates the VD services.
2) The master vehicle terminates the security links.
3) The master vehicle terminates the communication links. | +| 5 | Prerequisites | – Applied VDS services are successfully finished.
– The master vehicle is ready to perform the VDS stop process.
– The domain actors are also ready to perform the VDS stop process. | +| 6 | Operations | – The master vehicle is equipped with a VDS stop function.
– The domain actors are equipped with a VDS stop function. | +| 7 | End conditions | – The master vehicle successfully terminated the VD services and communication links. | + +# Appendix I + +## Scenario variations of vehicle domain dynamic map service + +(This appendix does not form an integral part of this Recommendation.) + +## I.1 General + +As described in clause 6.4.6, it is necessary to consider many service scenarios to pick up all BUCs and determine the system use elements. + +Some of these scenarios include specific features for the VDS and others are very general, but expressed by PAs of VDS. All scenarios will be considered to derive detailed requirements for specification of implementation provided in subsequent Recommendations in the series. + +## I.2 Scenario examples of traffic explorer service + +### I.2.1 Scenario TE1: Traffic explorer on a straight road + +Figure I.1 shows a typical scenario of a traffic explorer service on a straight road. The MV collects the response information from the DAs and generates a VDDM. + +![Diagram of Scenario TE1: Traffic explorer on a straight road. The diagram shows a road with a dashed center line. A Master vehicle (1) is in the center lane. Domain vehicle 1 (2) is to the left of the center lane, with Domain sensor 1 (5) further left. Domain vehicle 2 (3) is to the right of the center lane, with Domain sensor 2 (6) further right. Domain vehicle 3 (4) is in the leftmost lane. Domain participant 1 (7) is walking on the top shoulder, Domain participant 2 (8) is on a bicycle on the right shoulder, and Domain participant 3 (9) is walking on the bottom shoulder. The diagram is labeled F.749.5(21) in the bottom right corner.](24b1ac9eb58a2f22801620b9e2ea8bd3_img.jpg) + +F.749.5(21) + +Diagram of Scenario TE1: Traffic explorer on a straight road. The diagram shows a road with a dashed center line. A Master vehicle (1) is in the center lane. Domain vehicle 1 (2) is to the left of the center lane, with Domain sensor 1 (5) further left. Domain vehicle 2 (3) is to the right of the center lane, with Domain sensor 2 (6) further right. Domain vehicle 3 (4) is in the leftmost lane. Domain participant 1 (7) is walking on the top shoulder, Domain participant 2 (8) is on a bicycle on the right shoulder, and Domain participant 3 (9) is walking on the bottom shoulder. The diagram is labeled F.749.5(21) in the bottom right corner. + +##### Key + +| | | | | | | | | | | +|---|-----------------|---|----------------------|---|----------------------|---|----------------------|---|-----------------| +| 1 | Master vehicle | 2 | Domain vehicle 1 | 3 | Domain vehicle 2 | 4 | Domain vehicle 3 | 5 | Domain sensor 1 | +| 6 | Domain sensor 2 | 7 | Domain participant 1 | 8 | Domain participant 2 | 9 | Domain participant 3 | | | + +**Figure I.1 – Scenario TE1: Traffic explorer on a straight road** + +### I.2.2 Scenario TE2: Traffic explorer on a straight road with a green signal + +Figure I.2 shows a typical scenario of a traffic explorer service with a green signal on a straight road. DV1 responds with the driving status and domain sensor 1 responds with a green signal. The MV collects the response information from the DAs and generates a VDDM. + +![Diagram of Scenario TE2: Traffic explorer on a straight road with a green signal. The diagram shows a road with a dashed line down the center. From left to right, the elements are: a car (4), a car with a sensor icon (2), a car (1), a car (3) with a sensor icon (6) on its front, a person on a bicycle (8), and a traffic light (10) on the far left. Pedestrians (7 and 9) are shown crossing the road. The traffic light shows a green signal.](5eb69662cc4fa7d0d49b4eb22951c204_img.jpg) + +Diagram of Scenario TE2: Traffic explorer on a straight road with a green signal. The diagram shows a road with a dashed line down the center. From left to right, the elements are: a car (4), a car with a sensor icon (2), a car (1), a car (3) with a sensor icon (6) on its front, a person on a bicycle (8), and a traffic light (10) on the far left. Pedestrians (7 and 9) are shown crossing the road. The traffic light shows a green signal. + +F.749.5(21) + +##### **Key** + +| | | | | | | | | | | +|---|-----------------|---|----------------------|---|----------------------|---|----------------------|----|-----------------| +| 1 | Master vehicle | 2 | Domain vehicle 1 | 3 | Domain vehicle 2 | 4 | Domain vehicle 3 | 5 | Domain sensor 1 | +| 6 | Domain sensor 2 | 7 | Domain participant 1 | 8 | Domain participant 2 | 9 | Domain participant 3 | 10 | Green signal | + +**Figure I.2 – Scenario TE2: Traffic explorer on a straight road with a green signal** + +#### **I.2.3 Scenario TE3: Traffic explorer on a straight road with a red signal** + +Figure I.3 shows a typical scenario of a traffic explorer service with a red signal on a straight road. DV1 responds with a stopped status and the DS1 responds with a red signal. The MV collects the response information from the DAs and generates a VDDM. + +![Diagram of Scenario TE3: Traffic explorer on a straight road with a red signal. The diagram is identical to Figure I.2, but the traffic light (10) shows a red signal instead of a green one.](26e334e61dd059cff029338a2a604d8d_img.jpg) + +Diagram of Scenario TE3: Traffic explorer on a straight road with a red signal. The diagram is identical to Figure I.2, but the traffic light (10) shows a red signal instead of a green one. + +F.749.5(21) + +##### **Key** + +| | | | | | | | | | | +|---|-----------------|---|----------------------|---|----------------------|---|----------------------|----|-----------------| +| 1 | Master vehicle | 2 | Domain vehicle 1 | 3 | Domain vehicle 2 | 4 | Domain vehicle 3 | 5 | Domain sensor 1 | +| 6 | Domain sensor 2 | 7 | Domain participant 1 | 8 | Domain participant 2 | 9 | Domain participant 3 | 10 | Red signal | + +**Figure I.3 – Scenario TE3: Traffic explorer on straight road with a red signal** + +#### **I.2.4 Scenario TE4: Traffic explorer crossing an intersection** + +Figure I.4 shows a typical scenario of the traffic explorer service for crossing an intersection without a signal. DV1, DV2, DS1 and DS2 respond with a crossing or waiting status. The MV collects the response information from the DAs and generates a VDDM. + +![Figure I.4: Scenario TE4: Traffic explorer crossing an intersection. The diagram shows a cross-shaped intersection. A horizontal road has a master vehicle (1) on the right and a domain vehicle (4) on the left. A vertical road has a domain vehicle (2) at the top, a domain sensor (5) just below it, a domain vehicle (3) at the bottom, and a domain sensor (6) just above it. Pedestrians (7, 9) and a cyclist (8) are also shown on the horizontal road.](9a5927586a691c4908aa2cf98bd47ebb_img.jpg) + +Figure I.4: Scenario TE4: Traffic explorer crossing an intersection. The diagram shows a cross-shaped intersection. A horizontal road has a master vehicle (1) on the right and a domain vehicle (4) on the left. A vertical road has a domain vehicle (2) at the top, a domain sensor (5) just below it, a domain vehicle (3) at the bottom, and a domain sensor (6) just above it. Pedestrians (7, 9) and a cyclist (8) are also shown on the horizontal road. + +F.749.5(21) + +##### **Key** + +| | | | | | | | | | | +|---|-----------------|---|----------------------|---|----------------------|---|----------------------|---|-----------------| +| 1 | Master vehicle | 2 | Domain vehicle 1 | 3 | Domain vehicle 2 | 4 | Domain vehicle 3 | 5 | Domain sensor 1 | +| 6 | Domain sensor 2 | 7 | Domain participant 1 | 8 | Domain participant 2 | 9 | Domain participant 3 | | | + +**Figure I.4 – Scenario TE4: Traffic explorer crossing an intersection** + +## **I.3 Scenario examples of traffic reporter service** + +### **I.3.1 Scenario TR1: Traffic signal reporting on a straight road** + +Figure I.5 shows a typical scenario of a traffic reporter service for signal status on a straight road. MV2 collects the response information from the DAs and generates a VD map. If a valid signal status is detected from the VD map, MV2 issues the traffic report to share with the neighbouring MVs. The MV1 and MV3 receive it. + +![Figure I.5: Scenario TR1: Traffic signal reporting on a straight road. The diagram shows a straight road with three dashed circles representing vehicle domains. Domain 1 (bottom) contains a master vehicle (4) and a domain participant (9). Domain 2 (middle) contains a master vehicle (5) and a domain sensor (7). Domain 3 (top) contains a master vehicle (6), a domain sensor (8), and a domain participant (10). A green signal (11) is shown on the left side of the road.](4669a2ca9d019b9c2de9a9d9a0c4e644_img.jpg) + +Figure I.5: Scenario TR1: Traffic signal reporting on a straight road. The diagram shows a straight road with three dashed circles representing vehicle domains. Domain 1 (bottom) contains a master vehicle (4) and a domain participant (9). Domain 2 (middle) contains a master vehicle (5) and a domain sensor (7). Domain 3 (top) contains a master vehicle (6), a domain sensor (8), and a domain participant (10). A green signal (11) is shown on the left side of the road. + +F.749.5(21) + +##### **Key** + +| | | | | | | | | | | +|----|----------------------------------------------------|----|-----------------------------------------------|---|-----------------------------------------------|---|----------------------------------------------------|---|------------------| +| 1 | Vehicle domain 1 | 2 | Vehicle domain 2 | 3 | Vehicle domain 3 | 4 | Master vehicle 1 | 5 | Master vehicle 2 | +| 6 | Master vehicle 3 | 7 | Domain sensor 1 (belongs to vehicle domain 2) | 8 | Domain sensor 2 (belongs to vehicle domain 3) | 9 | Domain participant 1 (belongs to vehicle domain 1) | | | +| 10 | Domain participant 2 (belongs to vehicle domain 3) | 11 | Green signal | | | | | | | + +**Figure I.5 – Scenario TR1: Traffic signal reporting on a straight road** + +#### **I.3.2 Scenario TR2: Emergency vehicle traffic reporter on a straight road** + +Figure I.6 shows a typical scenario of a traffic reporter service for an approaching emergency vehicle on a straight road. MV3 collects response information from the DAs and generates a VD map. If a valid emergency vehicle is detected from the VD map, MV3 will share a traffic report with the neighbouring MVs. MV1 and MV2 receive it. + +![Figure I.6: Scenario TR2: Approaching emergency vehicle traffic reporting on a straight road. The diagram shows a road with three vehicle domains (1, 2, 3) indicated by dashed circles. Domain 1 contains Master vehicle 1 (4) and Domain participant 1 (9, a pedestrian). Domain 2 contains Master vehicle 2 (5) and Domain sensor 1 (7). Domain 3 contains Master vehicle 3 (6), Domain sensor 2 (8), Domain participant 2 (10, a cyclist), and Domain vehicle 1 (emergency vehicle) (11). A pedestrian is also shown on the left side of the road. The reference F.749.5(21) is in the bottom right corner.](0b7849dae424b0dd33e6386d2384643a_img.jpg) + +Figure I.6: Scenario TR2: Approaching emergency vehicle traffic reporting on a straight road. The diagram shows a road with three vehicle domains (1, 2, 3) indicated by dashed circles. Domain 1 contains Master vehicle 1 (4) and Domain participant 1 (9, a pedestrian). Domain 2 contains Master vehicle 2 (5) and Domain sensor 1 (7). Domain 3 contains Master vehicle 3 (6), Domain sensor 2 (8), Domain participant 2 (10, a cyclist), and Domain vehicle 1 (emergency vehicle) (11). A pedestrian is also shown on the left side of the road. The reference F.749.5(21) is in the bottom right corner. + +##### **Key** + +- | | | | | | | | | | | +|----|------------------------------------------------------------------|---|-----------------------------------------------|---|-----------------------------------------------|---|----------------------------------------------------|----|----------------------------------------------------| +| 1 | Vehicle domain 1 | 2 | Vehicle domain 2 | 3 | Vehicle domain 3 | 4 | Master vehicle 1 | 5 | Master vehicle 2 | +| 6 | Master vehicle 3 | 7 | Domain sensor 1 (belongs to vehicle domain 2) | 8 | Domain sensor 2 (belongs to vehicle domain 3) | 9 | Domain participant 1 (belongs to vehicle domain 1) | 10 | Domain participant 2 (belongs to vehicle domain 3) | +| 11 | Domain vehicle 1 (emergency vehicle belongs to vehicle domain 3) | | | | | | | | | + +**Figure I.6 – Scenario TR2: Approaching emergency vehicle traffic reporting on a straight road** + +#### **I.3.3 Scenario TR3: Traffic reporter for a temporary road block around an intersection** + +Figure I.7 shows a typical scenario of a traffic reporter service for a temporary road block around an intersection. MV2 collects the response information from the DAs and generates a VDDM. If a valid temporary road block such as a stationary vehicle that has broken down is detected in the VDDM, MV2 shares a traffic report with other neighbouring MVs. MV1, MV3 and MV4 receive and utilize it. + +![Figure I.7: Scenario TR3: Temporary road block around an intersection. The diagram shows an intersection with four vehicle domains (1, 2, 3, 4) indicated by dashed circles. Domain 1 contains Master vehicle 1 (5). Domain 2 contains Domain vehicle 2 (2), Master vehicle 2 (6), Domain sensor 1 (9), and Domain vehicle 1 (temporarily stops for trouble) (11). Domain 3 contains Domain vehicle 3 (3), Master vehicle 3 (7), and Domain sensor 2 (10). Domain 4 contains Master vehicle 4 (8). The reference F.749.5(21) is in the bottom right corner.](82fbb97c1145cac89ac72dd080fad17a_img.jpg) + +Figure I.7: Scenario TR3: Temporary road block around an intersection. The diagram shows an intersection with four vehicle domains (1, 2, 3, 4) indicated by dashed circles. Domain 1 contains Master vehicle 1 (5). Domain 2 contains Domain vehicle 2 (2), Master vehicle 2 (6), Domain sensor 1 (9), and Domain vehicle 1 (temporarily stops for trouble) (11). Domain 3 contains Domain vehicle 3 (3), Master vehicle 3 (7), and Domain sensor 2 (10). Domain 4 contains Master vehicle 4 (8). The reference F.749.5(21) is in the bottom right corner. + +##### **Key** + +- | | | | | | | | | | | +|----|-------------------------------------------------------------------------------|---|------------------|---|------------------|---|-----------------------------------------------|----|-----------------------------------------------| +| 1 | Domain vehicle 1 | 2 | Domain vehicle 2 | 3 | Domain vehicle 3 | 4 | Domain vehicle 4 | 5 | Master vehicle 1 | +| 6 | Master vehicle 2 | 7 | Master vehicle 3 | 8 | Master vehicle 4 | 9 | Domain sensor 1 (belongs to vehicle domain 2) | 10 | Domain sensor 2 (belongs to vehicle domain 3) | +| 11 | Domain vehicle 1 (temporarily stops for trouble, belongs to vehicle domain 2) | | | | | | | | | + +**Figure I.7 – Scenario TR3: Temporary road block around an intersection** + +## **I.4 Scenario examples of manoeuvre coordinator service** + +#### **I.4.1 Scenario MC1: Manoeuvre coordinator for a right lane change** + +Figure I.8 shows a typical scenario of a manoeuvre coordinator service for a right-lane change on a straight road. MV collects response information from the DAs and generates a VDDM. If the MV + +wants to make a right-lane change, it generates an appropriate driving manoeuvre plan with VDS master time. The MV requests their planned or predicted position from the relevant DVs. They respond to the MV with the generated position information. + +![Figure I.8: Scenario MC1: Manoeuvre coordinator for right lane change. The diagram shows a multi-lane road with four vehicles: 1 (Master vehicle), 2 (Domain vehicle 1), 3 (Domain vehicle 2), and 4 (Domain vehicle 3). Dashed lines represent driving manoeuvres: 5 for the master vehicle, 6 for domain vehicle 1, and 7 for domain vehicle 2. The master vehicle is in the middle lane, domain vehicle 1 is in the right lane, domain vehicle 2 is in the middle lane ahead of the master vehicle, and domain vehicle 3 is in the left lane. The manoeuvres show the master vehicle moving right, domain vehicle 1 moving right, and domain vehicle 2 moving left.](bb4d2112ed07e2031c92fbff3494af9f_img.jpg) + +Figure I.8: Scenario MC1: Manoeuvre coordinator for right lane change. The diagram shows a multi-lane road with four vehicles: 1 (Master vehicle), 2 (Domain vehicle 1), 3 (Domain vehicle 2), and 4 (Domain vehicle 3). Dashed lines represent driving manoeuvres: 5 for the master vehicle, 6 for domain vehicle 1, and 7 for domain vehicle 2. The master vehicle is in the middle lane, domain vehicle 1 is in the right lane, domain vehicle 2 is in the middle lane ahead of the master vehicle, and domain vehicle 3 is in the left lane. The manoeuvres show the master vehicle moving right, domain vehicle 1 moving right, and domain vehicle 2 moving left. + +F.749.5(21) + +##### **Key** + +- | | | | | +|-----------------------------------------|-----------------------------------------|--------------------|--------------------| +| 1 Master vehicle | 2 Domain vehicle 1 | 3 Domain vehicle 2 | 4 Domain vehicle 3 | +| 5 Driving manoeuvre of master vehicle | 6 Driving manoeuvre of domain vehicle 1 | | | +| 7 Driving manoeuvre of domain vehicle 2 | | | | + +**Figure I.8 – Scenario MC1: Manoeuvre coordinator for right lane change** + +#### **I.4.2 Scenario MC2: Manoeuvre coordinator for a right turn at an intersection** + +Figure I.9 shows a typical scenario of a manoeuvre coordinator service for a right turn at an intersection. The MV collects response information from DAs and generates a VDDM. If the MV wants to turn right at the closing intersection, it generates a driving manoeuvre plan for a right turn with VDS master time. The MV requests the planned or predicted position from relevant DVs. They respond to the MV with generated position information. + +![Figure I.9: Scenario MC2: Manoeuvre coordinator for a right turn at an intersection. The diagram shows a T-intersection. Vehicle 1 (Master vehicle) is on the horizontal road, about to turn right. Vehicle 2 (Domain vehicle 1) is on the top vertical road, about to turn right. Vehicle 3 (Domain vehicle 2) is on the bottom vertical road, about to turn right. Vehicle 4 (Domain vehicle 3) is on the horizontal road, about to turn left. Sensors 5 and 6 are located at the intersection. Dashed lines represent driving manoeuvres: 7 for the master vehicle, 8 for domain vehicle 1, 9 for domain vehicle 2, and 10 for domain vehicle 3.](bc9d0c0b02cbe628b1b6548cc1107734_img.jpg) + +Figure I.9: Scenario MC2: Manoeuvre coordinator for a right turn at an intersection. The diagram shows a T-intersection. Vehicle 1 (Master vehicle) is on the horizontal road, about to turn right. Vehicle 2 (Domain vehicle 1) is on the top vertical road, about to turn right. Vehicle 3 (Domain vehicle 2) is on the bottom vertical road, about to turn right. Vehicle 4 (Domain vehicle 3) is on the horizontal road, about to turn left. Sensors 5 and 6 are located at the intersection. Dashed lines represent driving manoeuvres: 7 for the master vehicle, 8 for domain vehicle 1, 9 for domain vehicle 2, and 10 for domain vehicle 3. + +F.749.5(21) + +##### **Key** + +- | | | | | | +|-----------------------------------------|------------------------------------------|-----------------------------------------|--------------------|-------------------| +| 1 Master vehicle | 2 Domain vehicle 1 | 3 Domain vehicle 2 | 4 Domain vehicle 3 | 5 Domain sensor 1 | +| 6 Domain sensor 2 | 7 Driving manoeuvre of master vehicle | 8 Driving manoeuvre of domain vehicle 1 | | | +| 9 Driving manoeuvre of domain vehicle 2 | 10 Driving manoeuvre of domain vehicle 3 | | | | + +**Figure I.9 – Scenario MC2: Manoeuvre coordinator for a right turn at an intersection** + +# Appendix II + +## Typical examples of the smart traffic architecture model + +(This appendix does not form an integral part of this Recommendation.) + +## II.1 General + +The smart traffic and transport information exchange architecture model is generated by a systematic approach to standardization. The basic policy of the systematic approach is generalization and modelling of functions that already exist explicitly or implicitly within traffic and city. Listed whole functions of traffic, transport and city are imported from a generalized information model and are allocated in a STAMP. + +Figure II.1 shows typical template for a STAMP. It is characterized by plotting functions on the horizontal axis against areas on the vertical axis. + +| 1 \ 7 | 8 | 9 | 10 | 11 | 12 | +|-------|---|---|----|----|----| +| 2 | | | | | | +| 3 | | | | | | +| 4 | | | | | | +| 5 | | | | | | +| 6 | | | | | | + +F.749.5(21) + +#### Key + +#### Vertical axis + +| | | | | | | +|---|------|---|-------------|---|-----------------| +| 1 | Area | 2 | Country | 3 | State/intercity | +| 4 | City | 5 | Town/street | 6 | Home | + +#### Horizontal axis + +| | | | | | | +|----|--------------------|----|----------------------------|----|------------------| +| 7 | Function | 8 | Traffic management | 9 | Public transport | +| 10 | Business transport | 11 | Commercial/consumer travel | 12 | Customer travel | + +Figure II.1 – Basic template for a smart traffic architecture model + +## II.2 Typical examples of the function domain service model + +#### II.2.1 Typical services in a customer domain + +Figure II.2 shows typical examples of a customer function domain. A customer domain is a functional service group consisting of general users or customer-driven vehicles and other actors. Typical services are those for intelligent transport system information or OEM telematics. + +| 1 \ 7 | 8 | 9 | 10 | 11 | 12 | +|-------|---|---|----|----|----| +| 2 | | | | | | +| 3 | | | | | | +| 4 | | | | | 13 | +| 5 | | | | | 14 | +| 6 | | | | | | + +F.749.5(21) + +##### **Key** + +##### **Vertical axis** + +- 1 Area +- 2 Country +- 3 State/intercity +- 4 City +- 5 Town/street +- 6 Home + +##### **Horizontal axis** + +- 7 Function +- 8 Traffic management +- 9 Public transport +- 10 Business transport +- 11 Commercial/consumer travel +- 12 Customer travel + +##### **Smart traffic entities** + +- 13 ITS information service +- 14 OEM telematics service + +**Figure II.2 – Typical customer function services** + +#### **II.2.2 Typical services in a commercial and consumer domain** + +Figure II.3 shows typical examples of a commercial and consumer function domain. A commercial and consumer domain is a functional service group provided by a consumer-based transport service, sometimes used as an alternative to public transport by customers. Typical services are those for taxi management or car sharing. + +| 1 \ 7 | 8 | 9 | 10 | 11 | 12 | +|-------|---|---|----|----|----| +| 2 | | | | | | +| 3 | | | | | | +| 4 | | | | 13 | | +| 5 | | | | 14 | | +| 6 | | | | | | + +F.749.5(21) + +##### **Key** + +##### **Vertical axis** + +- 1 Area +- 2 Country +- 3 State/intercity +- 4 City +- 5 Town/street +- 6 Home + +##### **Horizontal axis** + +- 7 Function +- 8 Traffic management +- 9 Public transport +- 10 Business transport +- 11 Commercial/consumer travel +- 12 Customer travel + +##### **Smart traffic entities** + +- 13 Taxi management service +- 14 Car-sharing service + +**Figure II.3 – Typical commercial and consumer function services** + +#### II.2.3 Typical services in a business domain + +Figure II.4 shows typical examples of a business function domain. A business domain is a functional service group consisting of transport or logistics vehicles and trucks, ranging from intercity transport to delivery service for baggage or food to homes. Typical services are those for logistics and transport management, baggage or food delivery. + +![A grid diagram showing business function services. The vertical axis is labeled 1 to 6, and the horizontal axis is labeled 7 to 12. The intersection of row 4 and column 10 contains three stacked boxes labeled 13, 14, and 15, connected by double-headed arrows.](e22af684d8e56d4c61e61bb5ddac1087_img.jpg) + +| | | | | | | +|-------|---|---|--------------------------|----|----| +| 1 \ 7 | 8 | 9 | 10 | 11 | 12 | +| 2 | | | | | | +| 3 | | | | | | +| 4 | | | 13
↕
14
↕
15 | | | +| 5 | | | | | | +| 6 | | | | | | + +A grid diagram showing business function services. The vertical axis is labeled 1 to 6, and the horizontal axis is labeled 7 to 12. The intersection of row 4 and column 10 contains three stacked boxes labeled 13, 14, and 15, connected by double-headed arrows. + +F.749.5(21) + +##### Key + +##### Vertical axis + +| | | | | | | +|---|------|---|-------------|---|-----------------| +| 1 | Area | 2 | Country | 3 | State/intercity | +| 4 | City | 5 | Town/street | 6 | Home | + +##### Horizontal axis + +| | | | | | | +|----|--------------------|----|----------------------------|----|------------------| +| 7 | Function | 8 | Traffic management | 9 | Public transport | +| 10 | Business transport | 11 | Commercial/consumer travel | 12 | Customer travel | + +##### Smart traffic entities + +| | | | | | | +|----|---------------------------------------|----|--------------------------|----|-----------------------| +| 13 | Logistic transport management service | 14 | Baggage delivery service | 15 | Food delivery service | +|----|---------------------------------------|----|--------------------------|----|-----------------------| + +Figure II.4 – Typical business function services + +#### II.2.4 Typical services in the public domain + +Figure II.5 shows typical examples of the public function domain. The public domain is the functional service group consisting of public transport. Typical services are those for buses, light-rail transit (LRT) or traffic and road use management monitoring and management. + +![A grid diagram with 6 columns (7-12) and 6 rows (1-6). The top-left cell (1,7) is split diagonally. Rows 2-6 are labeled 2-6 on the left. Columns 8-12 are labeled 8-12 at the top. In column 9, row 4 is cell 13 and row 5 is cell 14, with a double-headed arrow between them.](c1df61cc3717e878a48e530218403403_img.jpg) + +A grid diagram with 6 columns (7-12) and 6 rows (1-6). The top-left cell (1,7) is split diagonally. Rows 2-6 are labeled 2-6 on the left. Columns 8-12 are labeled 8-12 at the top. In column 9, row 4 is cell 13 and row 5 is cell 14, with a double-headed arrow between them. + +F.749.5(21) + +##### **Key** + +##### **Vertical axis** + +- | | | | +|--------|---------------|-------------------| +| 1 Area | 2 Country | 3 State/intercity | +| 4 City | 5 Town/street | 6 Home | + +##### **Horizontal axis** + +- | | | | +|-----------------------|-------------------------------|--------------------| +| 7 Function | 8 Traffic management | 9 Public transport | +| 10 Business transport | 11 Commercial/consumer travel | 12 Customer travel | + +##### **Smart traffic entities** + +- | | | +|-----------------------------------|-----------------------------------| +| 13 Bus monitor management service | 14 LRT monitor management service | +|-----------------------------------|-----------------------------------| + +**Figure II.5 – Typical public function services** + +#### **II.2.5 Typical services in the traffic manager domain** + +Figure II.6 shows typical examples of the traffic manager function domain. The traffic manager domain is the functional service group provided for public traffic monitoring, local traffic control and overall optimization controls by public or governmental organizations. Typical services are those for local traffic monitoring, traffic control, smart city traffic control management or central local dynamic server provision. + +![Diagram showing a grid of transport manager function services. The vertical axis (rows 1-6) represents Area, Country, State/intercity, City, Town/street, and Home. The horizontal axis (columns 7-12) represents Function, Traffic management, Public transport, Business transport, Commercial/consumer travel, and Customer travel. Smart traffic entities 13 (Local dynamic map service), 14 (Smart city traffic manager), 15 (Traffic control operator), and 16 (Traffic monitor operator) are stacked vertically in the 'Country' row under the 'Traffic management' function.](38cbce07f83fba6d5a7c46605bd5743f_img.jpg) + +| | | | | | | +|-------|----|---|----|----|----| +| 1 \ 7 | 8 | 9 | 10 | 11 | 12 | +| 2 | 13 | | | | | +| 3 | 14 | | | | | +| 4 | 15 | | | | | +| 5 | 16 | | | | | +| 6 | | | | | | + +Diagram showing a grid of transport manager function services. The vertical axis (rows 1-6) represents Area, Country, State/intercity, City, Town/street, and Home. The horizontal axis (columns 7-12) represents Function, Traffic management, Public transport, Business transport, Commercial/consumer travel, and Customer travel. Smart traffic entities 13 (Local dynamic map service), 14 (Smart city traffic manager), 15 (Traffic control operator), and 16 (Traffic monitor operator) are stacked vertically in the 'Country' row under the 'Traffic management' function. + +F.749.5(21) + +##### **Key** + +##### **Vertical axis** + +- | | | | +|--------|---------------|-------------------| +| 1 Area | 2 Country | 3 State/intercity | +| 4 City | 5 Town/street | 6 Home | + +##### **Horizontal axis** + +- | | | | +|-----------------------|-------------------------------|--------------------| +| 7 Function | 8 Traffic management | 9 Public transport | +| 10 Business transport | 11 Commercial/consumer travel | 12 Customer travel | + +##### **Smart traffic entities** + +- | | | +|------------------------------|-------------------------------| +| 13 Local dynamic map service | 14 Smart city traffic manager | +| 15 Traffic control operator | 16 Traffic monitor operator | + +**Figure II.6 – Typical transport manager function services** + +## **II.3 Typical functional service in cooperation with VDS** + +### **II.3.1 Smart city control manager with vehicle domain service** + +Figure II.7 shows typical examples of harmonized implementation of the smart city control manager and VDS. Traffic information collected by VDS is sent to a local TM or smart city traffic manager and is validated. The result from a SCTM or local traffic control is sent back to VDS as value-added information. + +![Diagram showing harmonization between SCTM and VDS. It features a grid with vertical axis (1-6) and horizontal axis (7-12). Entities 14, 15, and 16 are stacked vertically in column 8, rows 3, 4, and 5 respectively. Entity 13 is a large box in column 9, rows 4 and 5. Arrows show bidirectional relationships between 14 and 15, 15 and 16, and between 15 and 13, and between 16 and 13.](12c19090355e19922e23044633b9d1ea_img.jpg) + +Diagram showing harmonization between SCTM and VDS. It features a grid with vertical axis (1-6) and horizontal axis (7-12). Entities 14, 15, and 16 are stacked vertically in column 8, rows 3, 4, and 5 respectively. Entity 13 is a large box in column 9, rows 4 and 5. Arrows show bidirectional relationships between 14 and 15, 15 and 16, and between 15 and 13, and between 16 and 13. + +F.749.5(21) + +##### **Key** + +##### **Vertical axis** + +| | | | +|--------|---------------|-------------------| +| 1 Area | 2 Country | 3 State/intercity | +| 4 City | 5 Town/street | 6 Home | + +##### **Horizontal axis** + +| | | | +|-----------------------|-------------------------------|--------------------| +| 7 Function | 8 Traffic management | 9 Public transport | +| 10 Business transport | 11 Commercial/consumer travel | 12 Customer travel | + +##### **Smart traffic entities** + +| | | +|-----------------------------|-------------------------------| +| 13 Vehicle domain service | 14 Smart city traffic manager | +| 15 Traffic control operator | 16 Traffic monitor operator | + +**Figure II.7 – Typical harmonization between a SCTM and VDS** + +#### **II.3.2 Local dynamic map with vehicle domain service** + +Figure II.8 shows typical examples of harmonized implementation of the LDM and VDS. Traffic information collected by VDS is sent to the local dynamic server as the latest refresh report to the LDM. + +![Diagram showing harmonization between LDM and VDS. It features a grid with vertical axis (1-6) and horizontal axis (7-12). Entity 14 is in column 8, row 2. Entity 13 is a large box in column 9, rows 4 and 5. An arrow points from entity 14 down to row 5 and then right into entity 13.](da434ee158d8bd56122f990b91dc17ba_img.jpg) + +Diagram showing harmonization between LDM and VDS. It features a grid with vertical axis (1-6) and horizontal axis (7-12). Entity 14 is in column 8, row 2. Entity 13 is a large box in column 9, rows 4 and 5. An arrow points from entity 14 down to row 5 and then right into entity 13. + +F.749.5(21) + +##### **Key** + +##### **Vertical axis** + +| | | | +|--------|---------------|-------------------| +| 1 Area | 2 Country | 3 State/intercity | +| 4 City | 5 Town/street | 6 Home | + +##### **Horizontal axis** + +| | | | +|-----------------------|-------------------------------|--------------------| +| 7 Function | 8 Traffic management | 9 Public transport | +| 10 Business transport | 11 Commercial/consumer travel | 12 Customer travel | + +##### **Smart traffic entities** + +| | | +|---------------------------|------------------------------| +| 13 Vehicle domain service | 14 Local dynamic map service | +|---------------------------|------------------------------| + +**Figure II.8 – Typical harmonization between a LDM and VDS** + +# Appendix III + +## Reference model of vehicle domain service on vehicle multimedia system + +(This appendix does not form an integral part of this Recommendation.) + +## III.1 General + +As described in clause 6.7.4, some input and output signals of the VDS implementation are generally shared with those of the VMS. The relationship between the VDS and the VMS in the functional overview is represented in Figure 14, but because it is an overview diagram, it does not represent the actual situation of sharing input and output signals or the detailed relations of the outputs generated by the VDS. In order to express these details, a reference model describing detailed information about input and output signals and internal information flow is more appropriate, rather than an overview diagram. + +## III.2 Typical example of a reference model of VDS on VMS + +A typical VDDM service collects sensor and communication data provided by sensors outside a vehicle and communication network. Information media, such as sensors and network channels, could be shared between the VDS and VMS, but some dedicated information is directly sent only to VDS. A VDDMS generates dynamic traffic information based on a high definition map around the MV and sends it to the vehicle interactive HMI. A translation is required to be communicated by a VDS and VMS as a unique interface to the driver. + +Figure III.1 shows the typical input/output model of the VDS integrated with that of the VMS. The basic reference model of a VMS is provided in [b-ITU-T F.749.3]. + +![Figure III.1 – Reference model for data input/output of the VDS on VMS. The diagram shows three main components: Vehicle multimedia service (left), Vehicle multimedia unit (center), and Vehicle multimedia service output signal (right). The Vehicle multimedia service is divided into two sub-sections: 'Vehicle multimedia service input signal' and 'Vehicle domain service input signal'. The 'Vehicle multimedia service input signal' includes Cabin camera (Video), Cabin microphone (Audio), Cabin hard keys (Control), and Audio visual devices (Audio and visual). The 'Vehicle domain service input signal' includes Outside camera (Video/data), Radar (Data), Lidar (Data), Hypersonic sensor (Data), Broadcast satellite Rx antenna (RF), Cellular communication Rx antenna (RF), LEO satellite Rx antenna (RF), and Short-range communication Rx antenna (RF). All these inputs feed into the Vehicle multimedia unit. The Vehicle multimedia unit contains a 'Display processing' block and a 'Vehicle domain service' block. The 'Display processing' block receives 'Data' from the 'Vehicle domain service' block and sends 'Display input' (Data and Video) to the 'Display' and 'Speaker' in the 'Vehicle multimedia service output signal' section. The 'Vehicle domain service' block sends 'RF' signals to the 'Cellular communication Tx antenna', 'LEO satellite Tx antenna', and 'Short-range communication Tx antenna' in the 'Vehicle multimedia service output signal' section.](dbd074feb5cce1300f42f91da8f673d1_img.jpg) + +Figure III.1 – Reference model for data input/output of the VDS on VMS. The diagram shows three main components: Vehicle multimedia service (left), Vehicle multimedia unit (center), and Vehicle multimedia service output signal (right). The Vehicle multimedia service is divided into two sub-sections: 'Vehicle multimedia service input signal' and 'Vehicle domain service input signal'. The 'Vehicle multimedia service input signal' includes Cabin camera (Video), Cabin microphone (Audio), Cabin hard keys (Control), and Audio visual devices (Audio and visual). The 'Vehicle domain service input signal' includes Outside camera (Video/data), Radar (Data), Lidar (Data), Hypersonic sensor (Data), Broadcast satellite Rx antenna (RF), Cellular communication Rx antenna (RF), LEO satellite Rx antenna (RF), and Short-range communication Rx antenna (RF). All these inputs feed into the Vehicle multimedia unit. The Vehicle multimedia unit contains a 'Display processing' block and a 'Vehicle domain service' block. The 'Display processing' block receives 'Data' from the 'Vehicle domain service' block and sends 'Display input' (Data and Video) to the 'Display' and 'Speaker' in the 'Vehicle multimedia service output signal' section. The 'Vehicle domain service' block sends 'RF' signals to the 'Cellular communication Tx antenna', 'LEO satellite Tx antenna', and 'Short-range communication Tx antenna' in the 'Vehicle multimedia service output signal' section. + +F.749.5(21) + +LEO: low earth orbit; RF: radio frequency; Rx: receiver; Tx: transmitter + +**Figure III.1 – Reference model for data input/output of the VDS on VMS** + +VDS is one of the network services provided by the MV, so the basic input and output of the VDS are network communication channels such as cellular or short-range networks. A VDDMS generates a high-definition map from the VDS specific signals of light detection and ranging (LIDAR), radio detection and ranging (RADAR) and sensors via recognized metadata objects. Motion pictures provided by the outside cameras of a vehicle also generate metadata of foreign objects around the MV. Those metadata are integrated as a high-definition map in the VDS functional module. + +Network communication channels connected to the VDS are shared with the VMS in order to exchange other kinds of communication network services. Motion pictures acquired by cameras outside the vehicle are also shared in a similar fashion to the vehicle outside or surrounding monitor service of the VMS. + +A VDDMS has some user interactive functions, such as a traffic information monitor, warning message about closing in or dangerous traffic objects and an interactive messaging service between the driver in the MV and both the DVs and the participants in surrounding traffic. Driver condition monitoring by the vehicle cabin camera could be optional for other kinds of VDS service. These interactive HMI services with the driver are provided by the VMS and VDS that utilize VMS services. + +As explained in clause 6.7.2, the VDS function indicated in Figure III.1 expresses a logical function model and never shows a single physical unit. It is located in the VMS function in Figure III.1, but its function is independently implemented from VMS functions. The VDS shares some inputs or outputs with the VMS and uses its interactive HMI service. This Recommendation determines which VDS function is implemented on the multimedia network platform of the VMS. + +# Bibliography + +- [b-ITU-T F.749.3] Recommendation ITU-T F.749.3 (2020), *Use cases and requirements for vehicular multimedia networks*. +- [b-IEEE 1588] IEEE 1588-2019, *IEEE Standard for a precision clock synchronization protocol for networked measurement and control systems*. +- [b-IETF RFC 5905] IETF RFC 5905, *Network time protocol version 4: Protocol and algorithms specification*. +- [b-ISO/IEC 7498-1] ISO/IEC 7498-1:1994, *Information technology – Open Systems Interconnection – Basic reference model: The basic model*. +- [b-ISO 13111-1] ISO 13111-1:2017, *Intelligent transport systems (ITS) – The use of personal ITS station to support ITS service provision for travellers – Part 1: General information and use case definitions*. +- [b-ISO 13185-2] ISO 13185-2:2015, *Intelligent transport systems – Vehicle interface for provisioning and support of ITS services – Part 2: Unified gateway protocol (UGP) requirements and specification for vehicle ITS station gateway (V-ITS-SG) interface*. +- [b-ISO 20078-1] ISO 20078-1:2021, *Road vehicles – Extended vehicle (ExVe) web services – Part 1: Content and definitions*. +- [b-ISO 20078-2] ISO 20078-2:2021, *Road vehicles – Extended vehicle (ExVe) web services – Part 2: Access*. +- [b-ISO 20078-3] ISO 20078-3:2021, *Road vehicles – Extended vehicle (ExVe) web services – Part 3: Security*. +- [b-ISO/TR 20078-4] ISO/TR 20078-4:2021, *Road vehicles – Extended vehicle (ExVe) web services – Part 4: Control*. +- [b-ISO 23239-1] ISO 23239-1:2021, *Road vehicles – Vehicle domain service (VDS) – Part 1: General information and use case definitions*. +- [ISO/IEC TR 30110] ISO/IEC TR 30110:2015, *Information technology – Cross jurisdictional and societal aspects of implementation of biometric technologies – Biometrics and children*. +- [b-SAE] SAE International. *Automated driving – Levels of driving automation are defined in new SAE International Standard J3016*. Available [viewed 2021-12-15] at: +[https://web.archive.org/web/20180701034327/https://cdn.oemoffhighway.com/files/base/acbm/ooh/document/2016/03/automated\\_driving.pdf](https://web.archive.org/web/20180701034327/https://cdn.oemoffhighway.com/files/base/acbm/ooh/document/2016/03/automated_driving.pdf) +- [b-SAE J2945/1] SAE J2945/1\_2020, *On-board system requirements for V2V safety communications*. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.749.6-202304-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg b/marked/F/T-REC-F.749.6-202304-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d4d8969f805414689ab79cfd08c333d454d482b3 --- /dev/null +++ b/marked/F/T-REC-F.749.6-202304-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:636c3839edff955a5b6208530b05fa1c983ab153d90f00216517a7a99478b988 +size 7074 diff --git a/marked/F/T-REC-F.749.6-202304-I_PDF-E/8e14350b4b669119a3bdfca7869110ca_img.jpg b/marked/F/T-REC-F.749.6-202304-I_PDF-E/8e14350b4b669119a3bdfca7869110ca_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..6fce09b89527dfc8e48ef20450d7364144163cf6 --- /dev/null +++ b/marked/F/T-REC-F.749.6-202304-I_PDF-E/8e14350b4b669119a3bdfca7869110ca_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:42903bafb8e1e7d5622a634be82a6b29446e10bf77cbcc799e4bba73e78e9eba +size 23929 diff --git a/marked/F/T-REC-F.749.6-202304-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg b/marked/F/T-REC-F.749.6-202304-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e121fb14259bcab8e663c449b5d194383ba51283 --- /dev/null +++ b/marked/F/T-REC-F.749.6-202304-I_PDF-E/af7916c89a458fdab6c3f443217388ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:95b5b03627b5ad60a2c6c230c179959cc46c65dfcff8fe3c0567668a9dd8543c +size 34104 diff --git a/marked/F/T-REC-F.749.6-202304-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg b/marked/F/T-REC-F.749.6-202304-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..85900e4dc98e8648632ae0684d566003b99ba757 --- /dev/null +++ b/marked/F/T-REC-F.749.6-202304-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:986763860b61c28d221af4e0619f47e128d12f51e20c6631a23192770e1d1416 +size 27677 diff --git a/marked/F/T-REC-F.749.6-202304-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg b/marked/F/T-REC-F.749.6-202304-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..fc1b73fe1130940ae4a4672d1323f181e79fd713 --- /dev/null +++ b/marked/F/T-REC-F.749.6-202304-I_PDF-E/d4af765160d04ecef538e5066006dc77_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:983d30dba396660ef0e1a309846c947758092e1a1b4f4ca749cfd70fdebf9939 +size 34738 diff --git a/marked/F/T-REC-F.749.6-202304-I_PDF-E/ff0952ef692c9d960ce5f6708bcc9711_img.jpg b/marked/F/T-REC-F.749.6-202304-I_PDF-E/ff0952ef692c9d960ce5f6708bcc9711_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..aa2aec19a77e50da2daa766d2877255535ad83d4 --- /dev/null +++ b/marked/F/T-REC-F.749.6-202304-I_PDF-E/ff0952ef692c9d960ce5f6708bcc9711_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ffc5ecc7da435c27ae65216f019d963464ec7ec1d43c0f8c237fe2ccf662a33f +size 9875 diff --git a/marked/F/T-REC-F.749.6-202304-I_PDF-E/raw.md b/marked/F/T-REC-F.749.6-202304-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..4b40988e8c64c3188bd2b024a63f75eb1d317efc --- /dev/null +++ b/marked/F/T-REC-F.749.6-202304-I_PDF-E/raw.md @@ -0,0 +1,529 @@ + + +## Recommendation **ITU-T F.749.6 (04/2023)** + +SERIES F: Non-telephone telecommunication services +Multimedia services + +--- + +# **Requirements of vehicle information for automated driving in vehicle gateway platforms** + +![ITU logo](390120de4fe440c42fea8154fcaad334_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS NON-TELEPHONE TELECOMMUNICATION SERVICES + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multdestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | | +| | F.400–F.499 | +| DIRECTORY SERVICES | | +| | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | | +| | F.600–F.699 | +| MULTIMEDIA SERVICES | | +| | F.700–F.799 | +| ISDN SERVICES | | +| | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | | +| | F.850–F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | | +| | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## Recommendation ITU-T F.749.6 + +# Requirements of vehicle information for automated driving in vehicle gateway platforms + +## Summary + +Recommendation ITU-T F.749.6 specifies the requirements of vehicle information for automated driving in vehicle gateway platforms. Recommendation ITU-T F.749.6 introduces vehicle information for an automated driving system (ADS), followed by two different approaches to represent automated driving system-dedicated vehicle (ADS-DV) by its ownership. Finally, this Recommendation specifies the requirements to support two different approaches to represent ADS-DV. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.749.6 | 2023-04-29 | 16 | 11.1002/1000/15541 | + +## Keywords + +ADS, ADS-DV, requirements, vehicle information, VGP. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2023 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +###### Page + +| | | | +|-----|-------------------------------------------------|----| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| 3.1 | Terms defined elsewhere ..... | 1 | +| 3.2 | Terms defined in this Recommendation ..... | 2 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | Conventions ..... | 3 | +| 6 | Vehicle information for automated driving ..... | 3 | +| 6.1 | Vehicle perception information ..... | 3 | +| 6.2 | Vehicle map information ..... | 4 | +| 6.3 | Vehicle planning information ..... | 4 | +| 6.4 | Vehicle controller information ..... | 4 | +| 6.5 | Vehicle diagnosis information..... | 4 | +| 7 | Ownership of ADS-DV ..... | 4 | +| 7.1 | User-owned ADS-DV ..... | 5 | +| 7.2 | Service provider-owned ADS-DV ..... | 7 | +| 8 | Requirements ..... | 8 | +| 8.1 | Requirements of the ADS-DV ..... | 8 | +| 8.2 | Requirements of the service provider..... | 11 | +| | Bibliography ..... | 14 | + + + +# Requirements of vehicle information for automated driving in vehicle gateway platforms + +## 1 Scope + +This Recommendation specifies the requirements of vehicle information for automated driving in vehicle gateway platforms (VGPs). This Recommendation introduces vehicle information for automated driving systems (ADSs), followed by two different approaches to represent automated driving system-dedicated vehicles (ADS-DVs) by their ownership. Finally, this Recommendation specifies requirements to support two different approaches to representing ADS-DVs. + +This Recommendation addresses the following elements. + +- vehicle information for automated driving; +- ownership of ADS-DVs; +- requirements. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 automated driving system (ADS)** [b-SAE J3016]: The hardware and software that are collectively capable of performing the entire DDT on a sustained basis, regardless of whether it is limited to a specific operational design domain (ODD); this term is used specifically to describe a Level 3, 4, or 5 driving automation system. + +**3.1.2 ADS-dedicated vehicle (ADS-DV)** [b-SAE J3016]: An ADS-equipped vehicle designed for driverless operation under routine/normal operating conditions during all trips within its given ODD (if any). + +**3.1.3 dynamic driving task (DDT)** [b-SAE J3016]: All of the real-time operational and tactical functions required to operate a vehicle in on-road traffic, excluding the strategic functions such as trip scheduling and selection of destinations and waypoints, and including, without limitation, the following subtasks: + +1. Lateral vehicle motion control via steering (operational). +2. Longitudinal vehicle motion control via acceleration and deceleration (operational). +3. Monitoring the driving environment via object and event detection, recognition, classification, and response preparation (operational and tactical). + +4. Object and event response execution (operational and tactical). +5. Manoeuvre planning (tactical). +6. Enhancing conspicuity via lighting, sounding the horn, signalling, gesturing, etc. (tactical). + +**3.1.4 dynamic driving task (DDT) fallback** [b-SAE J3016]: The response by the user to either perform the DDT or achieve a minimal risk condition (1) after occurrence of a DDT performance-relevant system failure(s), or (2) upon operational design domain (ODD) exit, or the response by an ADS to achieve minimal risk condition, given the same circumstances. + +**3.1.5 object and event detection and response (OEDR)** [b-SAE J3016]: The subtasks of the dynamic driving task that include monitoring the driving environment (detecting, recognizing, and classifying objects and events and preparing to respond as needed) and executing an appropriate response to such objects and events (i.e., as needed to complete the dynamic driving task and/or dynamic driving task fallback). + +**3.1.6 operation design domain (ODD)** [b-SAE J3016]: Operating conditions under which a given driving automation system or feature thereof is specifically designed to function, including, but not limited to, environmental, geographical, and time-of-day restrictions, and/or the requisite presence or absence of certain traffic or roadway characteristics. + +**3.1.7 platform** [b-ITU-T G.1081]: A hardware and/or software architecture that serves as a foundation or base for realizing a certain functionality. + +**3.1.8 vehicle gateway (VG)** [b-ITU-T F.749.1]: A VG is a device in a vehicle that enables communications between a device in the vehicle and another device which may be physically located either inside the vehicle or outside the vehicle (e.g., roadside station, cloud-based server, etc.). A VG provides standardized interfaces and protocols, communications across heterogeneous networks, optimized network selection based on application needs and network QoS, arbitration and integration of network communications, security and switching network connections to maintain service continuity. + +**3.1.9 vehicle gateway platform (VGP)** [b-ITU-T F.749.1]: A VGP is the collection of ICT hardware and software in a vehicle operating as an open platform to provide an integrated runtime environment for delivering the communications services of a VG. A VGP may also provide higher layer communications services such as interaction with the driver through the driver-vehicle access services and so on. Subsystems dedicated solely to vehicle operation are not considered part of the VGP. Supported applications/services include ITS and infotainment. + +### **3.2 Terms defined in this Recommendation** + +This Recommendation defines the following terms: + +**3.2.1 automated driving:** A set of automation features based on information and communication technology to help driving a vehicle while not requiring the driver's full attention. + +NOTE – Automated driving requires software and hardware for localization, perception, behavioural management and control. + +**3.2.2 vehicle information:** Data generated by an ego vehicle. + +NOTE – There are various types of vehicle information, including: transmission; fuel type; mileage; and fuel efficiency. Vehicle information for automated driving, in particular, consists of that for perception, map position, planning, controller and diagnosis. + +## **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-----|--------------------------| +| ADS | Automated Driving System | +|-----|--------------------------| + +| | | +|--------|--------------------------------------------| +| ADS-DV | Automated Driving System-Dedicated Vehicle | +| DB | Database | +| DDT | Dynamic Driving Task | +| DTC | Diagnostic Trouble Code | +| GNSS | Global Navigation Satellite System | +| ICT | Information and Communication Technology | +| ID | Identifier | +| ITS | Intelligent Transport System | +| LIDAR | Light Detection And Ranging | +| ODD | Operational Design Domain | +| OEDR | Object and Event Detection and Response | +| OS | Operating System | +| QoS | Quality of Service | +| RADAR | Radio Detection And Ranging | +| VIN | Vehicle Identification Number | +| VG | Vehicle Gateway | +| VGP | Vehicle Gateway Platform | + +# 5 Conventions + +The phrase "**is required**" indicates a requirement that must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. + +The phrase "**is recommended**" indicates a requirement that is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +# 6 Vehicle information for automated driving + +Vehicle information refers to all data about a specific vehicle, from its model, year, vehicle identification number (VIN), registration information, to vehicle speed, engine rotations per minute, fuel consumption, location, distance travelled and any diagnostic trouble codes (DTCs) or warning messages. Vehicle information can be used for various purposes. Vehicle information for automated driving is the data that is collected and used by the ADS of the vehicle. + +## 6.1 Vehicle perception information + +Vehicle perception information is used to localize an ego vehicle and classify objects around it. Vehicle perception information such as global navigation satellite system (GNSS) location, inertial measurement unit and wheel odometry measurements are combined to determine the current location of an ego vehicle. In addition, vehicle map information sensed by light detection and ranging (LIDAR) and a camera may be incorporated to improve accuracy. Objects around an ego vehicle can be classified into dynamic and static. Vehicle perception information of dynamic objects detected by LIDAR, camera or radio detection and ranging (RADAR) is bounded by boxes, and the trajectory and motions of boxes are tracked to predict their future paths. For static objects, vehicle perception information from LIDAR or a camera may be combined with vehicle map information to identify and localize stationary on-road and off-road objects. Vehicle perception information plays a crucial role in performing OEDR. + +## 6.2 Vehicle map information + +Map information is used to develop a representation of the surrounding environment of an ego vehicle. Sources of information include vehicle maps of its occupancy grid, localization and roads in high definition, depending on their capabilities and applications. External sensors such as LIDAR and cameras are used to construct vehicle map information. Existing vehicle map information can be updated recurrently by combination with that of vehicle perception. Vehicle map information may also be used to perform better dynamic object predictions alongside vehicle perception information. + +### 6.3 Vehicle planning information + +Vehicle planning information is used to create paths from current locations to destinations. Sources of planning information are perception and map position of a vehicle. Vehicle planning information is separated into three steps: mission planning; behaviour planning; and local planning. Mission planning creates an entire long-term route to destinations, and behaviour planning determines how to manoeuvre by solving short-term decisions along the overall route safely. Local planning is then responsible for reactive and immediate actions by deciding a specific path and velocity profile while considering the long-term route and short-term decision. + +## 6.4 Vehicle controller information + +Vehicle controller information is used to actuate the ego vehicle to follow the given planned trajectory provided by the vehicle planning information. Vehicle controller information is divided into a lateral controller and a longitudinal controller. The lateral controller involves steering, such as turning and lane keeping. The longitudinal controller, such as proportional integral derivative control, regulates the throttle position, gear set and brake pedal position to control the desired velocity. Both lateral and longitudinal controller play an important role in maintaining the trajectory of an ego vehicle while following the vehicle planning information provided. + +## 6.5 Vehicle diagnosis information + +Diagnosis information is used to monitor and analyse the hardware failure and software inconsistencies of an ego vehicle and provide warnings and alerts if necessary. Vehicle diagnosis information is provided to the driver or the service provider to perform fallback. Vehicle diagnosis information such as DTCs or accident reports also acts as an input to failure mode and effects analysis, hazard and operability study and other safety frameworks for automated driving. + +# 7 Ownership of ADS-DV + +ADS-DV is an ADS-equipped vehicle designed for driverless operation, wherein ADS is hardware and software capable of performing the entire DDT on a sustained basis. Meanwhile, a VGP is a collection of ICT hardware and software to provide an integrated runtime environment for delivering the communications services. In this Recommendation, VGP is a component of ADS-DV to support additional requirements for automated driving. + +Figure 7-1 is a conceptual diagram of ADS-DV depending on its ownership. A service provider is a company or organization that offers a platform or application that allows users to access and plan their transportation needs using ADS-DV. A user is a person who uses or subscribes to ADS-DV. + +![Figure 7-1: Two approaches to ADS-DV ownership. The diagram shows two nested ownership models. The outer model, 'Service provider-owned ADS-DV (7.2)', contains a 'Service provider' box. The inner model, 'User-owned ADS-DV (7.1)', contains an 'ADS-DV' box, a 'VGP' box, and a 'User' box. Arrows indicate bidirectional communication between the 'Service provider' and the 'ADS-DV', and between the 'User' and the 'ADS-DV'. The 'VGP' box is also connected to the 'User' box.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +F.749.6(23) + +Figure 7-1: Two approaches to ADS-DV ownership. The diagram shows two nested ownership models. The outer model, 'Service provider-owned ADS-DV (7.2)', contains a 'Service provider' box. The inner model, 'User-owned ADS-DV (7.1)', contains an 'ADS-DV' box, a 'VGP' box, and a 'User' box. Arrows indicate bidirectional communication between the 'Service provider' and the 'ADS-DV', and between the 'User' and the 'ADS-DV'. The 'VGP' box is also connected to the 'User' box. + +**Figure 7-1 – Two approaches to ADS-DV ownership** + +## 7.1 User-owned ADS-DV + +An ADS-DV is capable of performing various tasks pre-defined by its absent owner. For example, when the user is at work, the ADS-DV visits multiple locations (e.g., supermarkets and petrol stations) and executes tasks. In addition, the ADS-DV diagnoses its condition and alerts the user if maintenance is required. + +A trip is a collection of tasks; a task is an action that users command ADS-DVs to execute. A task is defined by the user, ADS-DV, or other third party service providers. The order of tasks within a trip can be configured before or during the trip. In addition, a trip has a specific target time, $t$ , which is the time user wants the ADS-DV to arrive. + +In Figure 7-2, the user requests service execution to an ADS-DV. The ADS-DV is also capable of automatically commencing trips based on $t$ . The ADS-DV checks the trip and determines whether the trip can be completed based on the trip information and the current state of the ADS-DV before $t$ . For example, the ADS-DV considers the number, type, location of tasks, traffic conditions and any ongoing tasks to reorganize the tasks in a completable order. The ADS-DV selects the trip with the fastest estimated end time, $t_{ESTIMATE}$ . + +In some cases, however, it is not possible to complete before $t$ . In that case, the ADS-DV responds by informing the user whether the trip is complete. If the trip cannot be completed, the ADS-DV waits for the user to provide further instructions. + +![Figure 7-2: User-owned ADS-DV – Execution. This sequence diagram shows the interaction between a 'User' and an 'ADS-DV'. The 'User' sends a 'Request for service execution' to the 'ADS-DV'. The 'ADS-DV' then performs three internal steps: 'Check trip', 'Determine when trip is completable', and 'Execute task'. Finally, the 'ADS-DV' sends a 'Respond to request for service execution' back to the 'User'.](8e14350b4b669119a3bdfca7869110ca_img.jpg) + +F.749.6(23) + +Figure 7-2: User-owned ADS-DV – Execution. This sequence diagram shows the interaction between a 'User' and an 'ADS-DV'. The 'User' sends a 'Request for service execution' to the 'ADS-DV'. The 'ADS-DV' then performs three internal steps: 'Check trip', 'Determine when trip is completable', and 'Execute task'. Finally, the 'ADS-DV' sends a 'Respond to request for service execution' back to the 'User'. + +**Figure 7-2 – User-owned ADS-DV – Execution** + +In Figure 7-3, under control of the ADS, the ADS-DV starts the trip according to the request for execution. The ADS-DV periodically updates $t_{ESTIMATE}$ and compares it with $t$ . If $t_{ESTIMATE}$ does not exceed $t$ , the ADS-DV continues the trip and periodically recalculates $t_{ESTIMATE}$ . If $t_{ESTIMATE}$ exceeds $t$ , ADS-DV changes the order of tasks and re-calculates $t_{ESTIMATE}$ . After that, if $t_{ESTIMATE}$ does not exceed $t$ , the ADS-DV continues the changed trip. + +![Flowchart illustrating the interaction between a User and an ADS-DV for trip updates. The process starts with the ADS-DV sending a 'Start trip' message. It then enters a loop: a decision diamond asks if t_ESTIMATE > t. If 'No', it loops back to the start of the loop. If 'Yes', it proceeds to 'Change task order and recalculate t_ESTIMATE'. After this, another decision diamond asks if t_ESTIMATE > t. If 'Yes', it proceeds to a 'Continue trip?' decision diamond. If 'No', it proceeds to 'Continue trip'. From the 'Continue trip?' diamond, if 'Yes', it proceeds to 'Continue trip'. From 'Continue trip', the flowchart ends with the reference F.749.6(23).](d4af765160d04ecef538e5066006dc77_img.jpg) + +``` + +graph TD + ADS_DV[ADS-DV] --> StartTrip[Start trip] + StartTrip --> Decision1{t_ESTIMATE > t} + Decision1 -- No --> Decision1 + Decision1 -- Yes --> ChangeTask[Change task order and recalculate t_ESTIMATE] + ChangeTask --> Decision2{t_ESTIMATE > t} + Decision2 -- Yes --> Decision3{Continue trip?} + Decision2 -- No --> ContinueTrip[Continue trip] + Decision3 -- Yes --> ContinueTrip + ContinueTrip --> End[F.749.6(23)] + +``` + +Flowchart illustrating the interaction between a User and an ADS-DV for trip updates. The process starts with the ADS-DV sending a 'Start trip' message. It then enters a loop: a decision diamond asks if t\_ESTIMATE > t. If 'No', it loops back to the start of the loop. If 'Yes', it proceeds to 'Change task order and recalculate t\_ESTIMATE'. After this, another decision diamond asks if t\_ESTIMATE > t. If 'Yes', it proceeds to a 'Continue trip?' decision diamond. If 'No', it proceeds to 'Continue trip'. From the 'Continue trip?' diamond, if 'Yes', it proceeds to 'Continue trip'. From 'Continue trip', the flowchart ends with the reference F.749.6(23). + +**Figure 7-3 – User-owned ADS-DV – Update** + +If an ADS-DV cannot shorten $t_{\text{ESTIMATE}}$ , it notifies the user of the estimated time of delay and requests whether to continue the trip. In this case, the user instructs the ADS-DV to continue or stop the trip and return. Alternatively, the user changes $t$ or cancels tasks to continue the trip and finish on time before $t$ . + +As trips performed repeatedly, the difference, $t_{\Delta}$ , between the actual end time, $t_{\text{END}}$ , and $t_{\text{ESTIMATE}}$ , which is estimated at the beginning of the trip, is recursively fed back to the ADS-DV. In this way, future trips consider past data so that they can be completed before $t$ . In this case, the trigger time, $t_{\text{TRIGGER}}$ , is defined as a time that ensures ADS-DV successfully arrives at its final destination. + +In Figure 7-4, the ADS-DV periodically checks its remaining energy (e.g., petrol or electricity) to determine whether an energy supply is necessary. The ADS-DV calculates energy consumption periodically until the trip is completed and determines whether it is necessary to replenish energy. If the trip has not yet started, the ADS-DV adds a task to replenish energy for the upcoming trip. If the trip has already started, however, ADS-DV recalculates $t_{\text{ESTIMATE}}$ , assuming the energy-replenishing task has been added to the trip. If the recalculated $t_{\text{ESTIMATE}}$ exceeds $t$ , the ADS-DV notifies the user that an energy replenishment task is required to complete the trip. The user then instructs the ADS-DV to either continue by updating the trip or stop the trip. + +![Flowchart for User-owned ADS-DV Energy replenishment. The process starts with the User and ADS-DV. The ADS-DV checks remaining energy. If the trip started, it proceeds to 'Add energy replenishing task and recalculate t_ESTIMATE'. If the trip did not start, it checks if t_ESTIMATE > t. If Yes, it sends a message to the User. If No, it proceeds to 'Add energy replenishing task and recalculate t_ESTIMATE'. The User can also send an 'Update trip' message to the ADS-DV. The process ends with F.749.6(23).](af7916c89a458fdab6c3f443217388ae_img.jpg) + +``` + +graph TD + User[User] + ADS_DV[ADS-DV] + ADS_DV --> CheckEnergy[Check remaining energy] + CheckEnergy --> TripStarted{Trip started?} + TripStarted -- Yes --> AddTask[Add energy replenishing task and recalculate t_ESTIMATE] + TripStarted -- No --> TEstimate{t_ESTIMATE > t} + TEstimate -- Yes --> User + TEstimate -- No --> AddTask + User -- Update trip --> AddTask + AddTask --> F749623[F.749.6(23)] + +``` + +Flowchart for User-owned ADS-DV Energy replenishment. The process starts with the User and ADS-DV. The ADS-DV checks remaining energy. If the trip started, it proceeds to 'Add energy replenishing task and recalculate t\_ESTIMATE'. If the trip did not start, it checks if t\_ESTIMATE > t. If Yes, it sends a message to the User. If No, it proceeds to 'Add energy replenishing task and recalculate t\_ESTIMATE'. The User can also send an 'Update trip' message to the ADS-DV. The process ends with F.749.6(23). + +**Figure 7-4 – User-owned ADS-DV – Energy replenishment** + +In Figure 7-5, the ADS-DV periodically diagnoses the state of the vehicle before the trip starts or when there are no upcoming trips to visit repair shops according to the diagnosis result. If maintenance is needed, the ADS-DV makes a reservation for the repair shop to perform maintenance. If needed, this task is added to the ongoing trip. + +![Flowchart for User-owned ADS-DV Maintenance. The process starts with the ADS-DV. It then proceeds to 'Diagnose vehicle condition', 'Make reservation', and 'Perform maintenance'. The process ends with F.749.6(23).](ff0952ef692c9d960ce5f6708bcc9711_img.jpg) + +``` + +graph TD + ADS_DV[ADS-DV] --> Diagnose[Diagnose vehicle condition] + Diagnose --> MakeRes[Make reservation] + MakeRes --> PerformMaint[Perform maintenance] + PerformMaint --> F749623[F.749.6(23)] + +``` + +Flowchart for User-owned ADS-DV Maintenance. The process starts with the ADS-DV. It then proceeds to 'Diagnose vehicle condition', 'Make reservation', and 'Perform maintenance'. The process ends with F.749.6(23). + +**Figure 7-5 – User-owned ADS-DV – Maintenance** + +## 7.2 Service provider-owned ADS-DV + +When a service provider owns an ADS-DV, the ADS-DV serves as robo-taxis or personal transportation services. A personal transport system needs to be built by a personal transportation service provider owning an ADS-DV. + +The user calls the ADS-DV provided by a personal transportation service provider and requests transport to a particular destination. The terminal may provide a user interface to request a personal transportation service. The user interface may be a service request button or a search box, or may include a search box. Alternatively, the interface may include a device for recognizing the voice command of a user. In other words, the user may request a personal service from the transport system by voice command. + +The user terminal may provide the user with a window (or a box or bar) to search for the ADS-DV, manage a favourite list of the ADS-DV for personal transport service, and display a result for the service request of the user. + +The user may search for the ADS-DV through the search window based on various criteria, e.g., the name, size, type, characteristics, style, shape or colour of the vehicle. The user terminal may transmit search words to the personal transport system, receive a search result from it and display the result according to the request. + +The search result provided by the personal transport system may be a list of ADS-DVs that can currently provide the service. The available ADS-DV list may be sequentially listed with matching accuracy against the criteria of users or may be listed in the order closest to their current or calling location. The list of available the ADS-DV may be displayed with matching accuracy or distance from the current or calling location. + +The user may select at least one ADS-DV or the autonomous driving operating system (OS) among the search results displayed in the user terminal and add the selected ADS-DV or the autonomous driving OS of the ADS-DV to the favourite list in the user information database (DB). In addition, the user may delete the autonomous driving OS of the ADS-DV or the ADS-DV from the favourite list through the user terminal. + +After the trip is terminated, the ADS-DV waits for the call while hovering around the areas where the next service call is likely to occur or moves to a dedicated garage for self-charging or vehicle inspection. In the case of DDT fallback, if necessary, the ADS state is transitioned to the remote control state by connecting to the service provider. + +# 8 Requirements + +This clause specifies requirements based on vehicle information for automated driving and the ownership of ADS-DV described in clauses 6 and 7, respectively. An ADS-DV comprises a processor, memory and a communication device, wherein the processor executes a program (method) stored in the memory to perform the following requirements listed in clauses 8.1 and 8.2. + +### 8.1 Requirements of the ADS-DV + +### 8.1.1 User-owned ADS-DV + +Requirements for execution (Figure 7-2) follow. + +- [Req8.1.1-1] It is required for an ADS-DV to start a trip by controlling the ego vehicle using vehicle perception information, vehicle map information and vehicle planning information, and vehicle controller information. +- [Req8.1.1-2] It is required for an ADS-DV to calculate the estimated end time, $t_{\text{ESTIMATE}}$ , of the trip according to a predetermined update period using vehicle map information and vehicle planning information. +- [Req8.1.1-3] It is required for an ADS-DV to determine whether the trip is completed within target time, $t$ , according to $t_{\text{ESTIMATE}}$ , of the trip using vehicle map information and vehicle planning information. +- [Req8.1.1-4] It is required for an ADS-DV to receive a request for execution by the ADS-DV from the user. +- [Req8.1.1-5] It is required for an ADS-DV to determine whether the trip is completable according to the trip information and the current state of ADS-DV using vehicle map information and vehicle planning information. +- [Req8.1.1-6] It is required for an ADS-DV to respond to the request for execution according to whether the trip is completable. +- [Req8.1.1-7] It is recommended for an ADS-DV to include vehicle planning information in the request for service execution to have at least one task be performed by the ADS-DV. + +- [Req8.1.1-8] It is recommended for an ADS-DV to include a task type for at least one task and a completion time of the tasks as trip information. + +Requirements for updating (Figure 7-3) follow. + +- [Req8.1.1-9] It is required for an ADS-DV to constantly control the ego vehicle during manoeuvres based on the trip using vehicle perception information, vehicle map information, vehicle planning information, and vehicle controller information. +- [Req8.1.1-10] It is required for an ADS-DV to change the execution order of tasks included in the trip when it is determined that the trip cannot be completed within target time, $t$ . +- [Req8.1.1-11] It is required that an ADS-DV recalculate $t_{\text{ESTIMATE}}$ , according to the changed execution order using vehicle map information and vehicle planning information. +- [Req8.1.1-12] It is required that an ADS-DV perform the trip according to the changed execution order when the recalculated $t_{\text{ESTIMATE}}$ does not exceed $t$ . +- [Req8.1.1-13] It is required that an ADS-DV transmit a delay prediction notification of the trip to the user when the recalculated $t_{\text{ESTIMATE}}$ exceeds $t$ . +- [Req8.1.1-14] It is required that an ADS-DV determine whether to continue the trip based on a selection of the user according to the delay prediction notification. +- [Req8.1.1-15] It is required that an ADS-DV start the trip by controlling the ego vehicle after it is determined that the trip is completable. +- [Req8.1.1-16] It is required that an ADS-DV calculate an expected completion time of the trip according to a predetermined update period using vehicle map information and vehicle planning information. +- [Req8.1.1-17] It is required that an ADS-DV determine whether the trip is completed within a target time according to the expected completion time of the trip and change the execution order of tasks included in the trip according to the determination result. +- [Req8.1.1-18] It is required that an ADS-DV change the sequence of tasks and re-calculate $t_{\text{ESTIMATE}}$ when $t_{\text{ESTIMATE}}$ exceeds $t$ using vehicle map information and vehicle planning information. +- [Req8.1.1-19] It is required for an ADS-DV to notify the estimated time of delay to the user if the ADS-DV cannot shorten the $t_{\text{ESTIMATE}}$ of the trip. +- [Req8.1.1-20] It is recommended for an ADS-DV to feed back the difference, $t_{\Delta}$ , between the actual end time, $t_{\text{END}}$ , and $t_{\text{ESTIMATE}}$ , which is estimated at the beginning of the trip, to ADS-DV as trips are repeatedly performed. + +Requirements for energy replenishment (Figure 7-4) follow. + +- [Req8.1.1-21] It is required for an ADS-DV to periodically check its remaining energy and whether further supply is required. +- [Req8.1.1-22] It is required for an ADS-DV to add an additional task to replenish energy for the upcoming trip if the trip has not yet started. +- [Req8.1.1-23] It is required for an ADS-DV to recalculate $t_{\text{ESTIMATE}}$ if the energy replenishment task is added when the trip has already started using vehicle map information and vehicle planning information. +- [Req8.1.1-24] It is required for an ADS-DV to notify the user that an energy replenishment task is required to complete the trip if the recalculated $t_{\text{ESTIMATE}}$ exceeds $t$ . +- [Req8.1.1-25] It is recommended for an ADS-DV to calculate energy consumption periodically until the trip is completed. + +Requirements for maintenance (Figure 7-5) follow. + +- [Req8.1.1-26] It is required for an ADS-DV to periodically diagnose the state of the vehicle before the trip starts and when there are no upcoming trips using vehicle diagnosis information. +- [Req8.1.1-27] It is recommended for an ADS-DV to request the repair shop to perform maintenance if needed. +- [Req8.1.1-28] It is recommended for an ADS-DV to add an additional maintenance task to the ongoing trip if necessary. + +### **8.1.2 Service provider-owned ADS-DV** + +A service provider owning an ADS-DV is required to provide a personal transport service. An ADS-DV includes a communication device, an object recognition device, a route search device and a driving control device. The ADS-DV requirements follow. + +- [Req8.1.2-1] It is recommended for an ADS-DV that the communication interface transfer information received by the communication device to devices for object recognition, route search and driving control. +- [Req8.1.2-2] It is recommended for an ADS-DV that the communication interface transfer information generated from devices for object recognition, route search, and driving control to the communication device. +- [Req8.1.2-3] It is recommended for an ADS-DV that the communication device communicate between the ADS-DV and the personal transport system of the service provider. +- [Req8.1.2-4] It is recommended for an ADS-DV that the communication device communicate with other vehicles outside the ADS-DV, a mobile device of a passenger and objects on a road. +- [Req8.1.2-5] It is recommended for an ADS-DV that the communication device receive information from and transmits information to the outside using various communication standards (e.g., vehicle to everything), as well as cellular and local area mobile communication (e.g., wireless fidelity). +- [Req8.1.2-6] It is recommended for an ADS-DV that information received from and to be transmitted to the outside go through the communication interface in the ADS-DV. +- [Req8.1.2-7] It is recommended for an ADS-DV that the object recognition device check its current location through sensors (e.g., camera, RADAR, LIDAR, GNSS) installed in, identifies objects around, and predicts the motion of the objects around the ADS-DV using vehicle perception information. +- [Req8.1.2-8] It is recommended for an ADS-DV that the object recognition device determines whether the user is authenticated by the personal transport system by recognizing the face of the user approaching the ADS-DV when it is called. +- [Req8.1.2-9] It is recommended for an ADS-DV that users input their face information into the personal transport system and agree to the object recognition policy of the autonomous vehicle. +- [Req8.1.2-10] It is recommended for an ADS-DV that the route search device use vehicle map information of the operating area of the ADS-DV and various sensors (e.g., GNSS sensor) to wander around a predetermined area for users to board or to move to their calling location. +- [Req8.1.2-11] It is recommended for an ADS-DV that the route search device look for a route to a target location input by the user using the vehicle map information and the sensors, and transmit the route information to the driving control device using vehicle planning information. + +- [Req8.1.2-12] It is recommended for an ADS-DV that the vehicle map information include maps of the occupancy grid, positioning and road details. +- [Req8.1.2-13] It is recommended for an ADS-DV that the occupancy grid map be used to identify dynamic objects and predict their motion or behaviour. +- [Req8.1.2-14] It is recommended for an ADS-DV that the positioning map be used to identify distances to nearby objects. +- [Req8.1.2-15] It is recommended for an ADS-DV that a detailed road map be used in a route search to a destination by the appropriate device. +- [Req8.1.2-16] It is recommended for an ADS-DV that the driving control device control the ADS-DV according to route information transmitted from the route search device using vehicle information from map reading, planning and controller. +- [Req8.1.2-17] It is recommended for an ADS-DV that the control of the ADS-DV include longitudinal and lateral direction controls using vehicle controller information. +- [Req8.1.2-18] It is recommended for an ADS-DV that the driving control device control the ADS-DV according to a driving manner selected by the user using vehicle controller information. +- [Req8.1.2-19] It is recommended for an ADS-DV that the driving control device control the ADS-DV so that the user can feel the speed as quickly as possible within the traffic regulations of the road when the user inputs “sporty” as the driving manner using vehicle controller information. +- [Req8.1.2-20] It is recommended for an ADS-DV that the driving control device consider not only the route information to the destination, but also the instruction received from the personal transport system and adjust the driving speed, lane, etc. by identifying surrounding objects in real time using vehicle perception information. + +## 8.2 Requirements of the service provider + +The service provider requirements include the following. + +- [Req8.2-1] It is required for the service provider to provide a personal transportation service comprising a processor, a memory and a communication device. +- [Req8.2-2] It is required for the processor to execute a program stored in the memory to receive a request for a personal transportation service using an ADS-DV from a user terminal. +- [Req8.2-3] It is required for the processor to execute a program stored in the memory to analyse a call pattern of the user for the ADS-DV. +- [Req8.2-4] It is required for the processor to execute a program stored in the memory to determine a recommended ADS-DV to provide the personal transportation service to the user based on the analysis result of the call pattern. +- [Req8.2-5] It is recommended for the processor to query a call history of the user and an idle ADS-DV around a call location of the user and analyse the call pattern based on the call history and the idle ADS-DV when the processor analyses a call pattern of the user for the ADS-DV. +- [Req8.2-6] It is recommended for the processor to query a favourite list of the user for the ADS-DV when the processor analyses a call pattern of the user for the ADS-DV, where the favourite list includes an ADS-DV or an autonomous driving OS for the ADS-DV preferred by the user. +- [Req8.2-7] It is recommended for the processor to analyse the call pattern based on the favourite list, the call history, and the idle ADS-DV around the call location when the processor analyses the call pattern based on the call history and the idle ADS-DV around the call location. + +- [Req8.2-8] It is recommended for the processor to receive a search request for an ADS-DV from the user terminal when the processor receives a request for a personal transportation service using an ADS-DV from a user terminal, where the search request includes at least one of the following items: a name; a size; a type; characteristics; a style; a shape; and a colour of the ADS-DV. +- [Req8.2-9] It is recommended for the processor to execute the program to further transmit at least one available ADS-DV to the user terminal in response to the search request, where at least one available ADS-DV is listed in an order of matching accuracy for search criteria of the user or in an order close to the current or calling location of the user. +- [Req8.2-10] It is recommended for the processor to execute the program to further determine a waiting route for each ADS-DV based on the analysis result of the call pattern. +- [Req8.2-11] It is recommended for the processor to execute the program to further receive a request for the waiting route from an idle ADS-DV without a passenger and within which no call has been received, and transmit the waiting route determined by the analysis result of the call pattern to the idle ADS-DV. +- [Req8.2-12] It is recommended for the recommended ADS-DV to include an idle vehicle with no passengers or a scheduled idle vehicle from which a passenger is about to disembark. +- [Req8.2-13] It is recommended that a user interface be provided to request a personal transportation service. The user interface may be a service request button or a search box. Alternatively, the user interface may include a device for recognizing the user's command. In other words, the user may request a personal transportation service from the personal transport system by voice command. +- [Req8.2-14] It is recommended that the user be provided with a window (or box or bar) to search for the ADS-DV, manage a favourite list of the ADS-DV for the personal transportation service, and display a result for the service request of the user. + +The service provider manages a vehicle information DB, a user information DB, a call pattern analysis device and a control device. The related requirements include the following. + +- [Req8.2-15] It is recommended that vehicle information about the ADS-DV be stored in the vehicle information DB of a service system such as a personal transport system. +- [Req8.2-16] It is recommended that the vehicle information include a vehicle registration number, a VIN or a vehicle serial number. +- [Req8.2-17] It is recommended that the vehicle information include information to be used during autonomous driving (self-driving-related information), where the self-driving-related information may include object recognition information, map information, driving route information, vehicle control information and vehicle diagnosis information. +- [Req8.2-18] It is recommended that the vehicle information include whether the passenger is in the vehicle and vehicle reservation information. +- [Req8.2-19] It is recommended that the VIN be an identifier (ID) uniquely assigned to each ADS-DV, such as a chassis number, and is used for mapping with the user information DB. +- [Req8.2-20] It is recommended that self-driving-related information, which is determined to be necessary for safe autonomous driving (e.g., vehicle diagnosis information), be periodically uploaded to the personal transport system. +- [Req8.2-21] It is recommended that driving route information be periodically uploaded to the personal transport system. +- [Req8.2-22] It is recommended that object recognition information inside or outside the vehicle be periodically uploaded to verify users riding in the ADS-DV to the personal transport system. + +- [Req8.2-23] It is recommended that driver information of the ADS-DV in the vehicle information DB, where the driver information of the ADS-DV may include accident history and driving tendency (safety or speed priority, etc.), be stored. +- [Req8.2-24] It is recommended that information necessary for the personal transport system be stored in the user information DB to manage users of the personal transportation service, where the user information DB may include an ID, a personal identification number, and personal information (phone number, e-mail address, etc.). +- [Req8.2-25] It is recommended that a favourite list of the user be stored in the user information DB. +- [Req8.2-26] It is recommended that the user manage the autonomous driving OS of the ADS-DV or the ADS-DV in the favourite list through the user terminal. +- [Req8.2-27] It is recommended that the user input a preferred ADS-DV or preferred autonomous driving OS to the user information DB and manage the ADS-DV of a predetermined number or less as the favourite list. +- [Req8.2-28] It is recommended that the personal transportation service provider supply the service based on the favourite list of the user. +- [Req8.2-29] It is recommended that users add their preferred ADS-DV or add a specific type of ADS-DV to their favourites list. +- [Req8.2-30] It is recommended that a call history of the ADS-DV or usage history of the personal transportation service be stored in the user information DB, where the call history of a user may include an OS, a size (light car, small, semi-medium, medium, semi-large, large, etc.), a type (sedan, sports utility vehicle, wagon, hatchback, etc.), a name (model name, etc.) and manufacturers. +- [Req8.2-31] It is recommended that the call pattern analysis device analyse a call pattern of the user by using machine learning technology (e.g., deep learning) based on the favourite list and the call history in the user information DB. +- [Req8.2-32] It is recommended that the call pattern analysis device be installed on a server in which the personal transport system operates, not the ADS-DV, since the object recognition device of the ADS-DV can identify a user using deep learning. +- [Req8.2-33] It is recommended that the call pattern analysed by the call pattern analysis device to the control device, where the control device may determine waiting routes (or waiting location, mooring area) of the individual ADS-DV based on a plurality of call patterns, be transmitted. +- [Req8.2-34] It is recommended that the control device manage the locations and routes of the ADS-DV in the personal transport system based on real-time traffic information collected from the ADS-DVs and may determine the waiting route of each ADS-DV based on the calling pattern of the plurality of call pattern of the users. +- [Req8.2-35] It is recommended that the control device recommend the ADS-DV to the corresponding user using the calling pattern of the specific user determined by the calling pattern analysing device, information in the vehicle information DB, and information about the corresponding user in the user information DB. + +## Bibliography + +- [b-ITU-T F.749.1] Recommendation ITU-T F.749.1 (2015), *Functional requirements for vehicle gateways*. +- [b-ITU-T F.749.2] Recommendation ITU-T F.749.2 (2017), *Service requirements for vehicle gateway platforms*. +- [b-ITU-T G.1081] Recommendation ITU-T G.1081 (2008), *Performance monitoring points for IPTV*. +- [b-ITU-T H.550] Recommendation ITU-T H.550 (2017), *Architecture and functional entities of vehicle gateway platforms*. +- [b-SAE J3016] SAE J3016 (2021), *Taxonomy and definitions for terms related to driving automation systems for on-road motor vehicles*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | 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It features a blue globe with a white grid pattern, overlaid by the letters 'ITU' in a bold, blue, sans-serif font. The globe is stylized with a white arrow pointing upwards and to the right, symbolizing global connectivity and communication. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.751.10 + +# Framework and requirements for distributed ledger technology (DLT)-based digital collection services + +## Summary + +DLT-based digital collection services are provided by distributed ledger technology (DLT) systems to perform various operations on digital collections, including issuance, sale, purchase, auction, transaction, transfer, etc. + +Recommendation ITU-T F.751.10 specifies a framework and requirements for DLT-based digital collection services, and may be used to guide the DLT-based digital collection services. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.751.10 | 2023-09-13 | 16 | 11.1002/1000/15624 | + +## Keywords + +Digital collection service, distributed ledger technology, framework and requirements. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2023 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|----------------------------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Overview ..... | 2 | +| 7 Overall architecture ..... | 2 | +| 7.1 Architecture of the DLT-based digital collection service system ..... | 2 | +| 7.2 Core functional components..... | 3 | +| 8 Information flows ..... | 4 | +| 8.1 Overall information flow diagram..... | 4 | +| 8.2 Information flows of the digital collection service platform..... | 5 | +| 8.3 Information flows of the digital collection user ..... | 5 | +| 9 Functional requirements ..... | 5 | +| 9.1 Functional requirements of the DLT-based digital collection service client ..... | 5 | +| 9.2 Functional requirements of the DLT-based digital collection service platform ..... | 6 | +| 9.3 Functional requirements of the DLT system ..... | 7 | +| 9.4 Performance requirements..... | 8 | +| 9.5 Security requirements..... | 9 | +| Appendix I – Examples of the DLT-based digital collection services ..... | 11 | +| I.1 DLT-based digital culture collections ..... | 11 | +| I.2 DLT-based digital music collections..... | 11 | +| I.3 DLT-based digital game assets..... | 11 | +| I.4 DLT-based digital sport assets ..... | 11 | +| I.5 DLT-based digital tickets ..... | 11 | +| Appendix II – Value of using DLT for digital collection services ..... | 12 | +| II.1 Guarantee authenticity, durability and continuity ..... | 12 | +| II.2 Ownership confirmation and information traceability ..... | 12 | +| II.3 Enhance collection value through uniqueness and scarcity ..... | 12 | +| II.4 Reduce transaction costs and improve circulation ..... | 12 | +| II.5 Speed-up the construction of the digital collection trading market..... | 12 | +| Bibliography..... | 13 | + + + +# Recommendation ITU-T F.751.10 + +## Framework and requirements for distributed ledger technology (DLT)-based digital collection services + +# 1 Scope + +This Recommendation specifies a framework and requirements for DLT-based digital collection services. It includes the overall architecture, information flows and functional requirements for DLT-based digital collection services. + +This Recommendation may be used as guidance by the relevant parties to research, develop, test, deploy and manage the DLT-based digital collection services. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T F.751.2] Recommendation ITU-T F.751.2 (2020), *Reference framework for distributed ledger technologies*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 account** [b-ITU-T F.751.1]: Representation of an entity whose data is recorded on a distributed ledger. + +**3.1.2 asset** [b-ITU-T F.751.0]: A representation of value. It can be a diamond, a unit of currency, items inside a shipping container, etc. An asset can be physical or virtual. + +**3.1.3 consensus** [b-ITU-T F.751.0]: Agreement that a set of transactions is valid. + +**3.1.4 distributed ledger** [b-ISO 22739]: A ledger that is shared across a set of DLT nodes and synchronized between the DLT nodes using a consensus mechanism. + +**3.1.5 distributed ledger technology (DLT)** [b-ITU-T F.751.1]: Technology enabling large groups of nodes in distributed ledger networks to reach agreement and record information without the need for a central authority. + +**3.1.6 ledger** [b-ITU-T F.751.0]: Information store that keeps final and definitive (immutable) records of transactions. + +**3.1.7 node** [b-ITU-T F.751.0]: Device or process that participates in a distributed ledger network. + +**3.1.8 private distributed ledger technology system** [b-ISO 22739]: DLT system that is accessible for use only to a limited group of DLT users. + +**3.1.9 smart contract** [b-ITU-T F.751.0]: Program written on the distributed ledger system that encodes the rules for specific types of distributed ledger system transactions in a way that can be validated and triggered by specific conditions. + +**3.1.10 transaction** [b-ITU-T F.751.0]: An incident or an operation that leads to a change in the status of a ledger, such as adding a record or equivalent exchange based on currency. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 DLT-based digital collection:** Digital collection generated and issued by a private distributed ledger technology (DLT) system, which is non-fungible and has a unique identifier. + +**3.2.2 DLT-based digital collection service:** Digital collection service provided by a private distributed ledger technology (DLT) system, which can use a private DLT platform to perform various operations on digital collections, including issuance, sale, purchase, auction, transaction, transfer, etc. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +DCS Digital Collection Service + +DDoS Distributed Denial of Service + +DLT Distributed Ledger Technology + +P2P Peer-to-Peer + +PKI Public Key Infrastructure + +SDK Software Development Kit + +# 5 Conventions + +In this Recommendation: + +- The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. +- The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. +- The keywords "can optionally" indicate an optional requirement which is permissible, without implying any sense of being recommended. This term is not intended to imply that the vendor's implementation must provide the option and the feature can be optionally enabled by the network operator or service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with this Recommendation. + +# 6 Overview + +DLT-based digital collections are generated and issued by private distributed ledger technology (DLT) systems. They are non-fungible, and each has a unique identifier. They can only be owned by the DLT users who have passed an identity authentication. DLT-based digital collections are indivisible, unchangeable, and verifiable. + +DLT-based digital collections use DLT to indicate the ownership of a certain digital collection. DLT can mark the owner of the digital collection in the DLT network. DLT-based digital collections are indivisible, unique, and the values are not equal. DLT can be used to support the issuance, circulation, management, and other functions of digital collections. + +# 7 Overall architecture + +## 7.1 Architecture of the DLT-based digital collection service system + +The overall architecture of DLT-based digital collection services is shown in Figure 1. + +![Figure 1: Architecture of the DLT-based digital collection service system. The diagram shows four main layers: DLT-based digital collections, Digital collection service platform, Digital collection service client, and DLT system. The DLT system is further divided into Smart contract layer, DLT network layer, and Physical layer. Arrows indicate bidirectional communication between adjacent layers.](b3baf3a29b67c7425d2562ddbc52f0cc_img.jpg) + +The diagram illustrates the architecture of the DLT-based digital collection service system, organized into four main horizontal layers connected by bidirectional arrows. + +- DLT-based digital collections:** The top layer, containing boxes for "Digital artworks", "Music and movie", "Game props", "Digital tickets", and "....". +- Digital collection service platform:** The second layer, containing a 3x3 grid of modules: "Identity registration management", "User account management", "Original review"; "Digital collection issuance", "Digital collection catalogue", "Digital collection sell"; and "Digital collection auction", "Digital collection trade", "Digital collection transfer". +- Digital collection service client:** The third layer, containing a 3x3 grid of modules: "Registration and authentication", "Mnemonic management", "Private key management"; "Account management", "Message notification", "Security setting"; and "Digital collection catalogue", "Digital collection acceptance", "Digital collection transfer". +- DLT system:** The bottom layer, enclosed in a dashed box, containing three sub-layers: + - Smart contract layer:** Contains "Identity management smart contract" and "Digital collection management smart contract". + - DLT network layer:** Contains "Consensus module", "Distributed ledger module", "Cryptography module", "P2P network module", and "Node management module". + - Physical layer:** Contains "Physical machine" and "Cloud platform". + +Figure 1: Architecture of the DLT-based digital collection service system. The diagram shows four main layers: DLT-based digital collections, Digital collection service platform, Digital collection service client, and DLT system. The DLT system is further divided into Smart contract layer, DLT network layer, and Physical layer. Arrows indicate bidirectional communication between adjacent layers. + +F.751.10(23) + +**Figure 1 – Architecture of the DLT-based digital collection service system** + +The DLT-based digital collection service system includes the DLT system, digital collection service platform, digital collection service client and DLT-based digital collections. + +## 7.2 Core functional components + +### 7.2.1 DLT system + +The DLT system mainly includes the physical layer, the DLT network layer and the smart contract layer. + +- The physical layer can be a physical machine or a cloud platform. +- The DLT network layer provides DLT network services, including a consensus module, distributed ledger module, cryptography module, peer-to-peer (P2P) network module, and node management module. These modules cooperate with each other to ensure that each node in the DLT network forms a consensus on the transaction, thereby ensuring the consistency of the node data. +- The smart contract layer contains an identity management smart contract and digital collection management smart contracts. + +The reference framework of a DLT system is described in [ITU-T F.751.2]. + +### 7.2.2 Digital collection service platform + +The digital collection service platform is deployed in the server backend to provide functions such as identity registration management, user account management, and original review, issuance, display, sale, transaction, auction, and transfer of digital collections. + +### 7.2.3 Digital collection service client + +The digital collection service client is for users to realize the management of digital collections, including real-name authentication and registration, mnemonic management, private key management, account management, message notification, security settings, digital collection catalogue, digital collection acceptance, digital collection transfer and other functions. + +### 7.2.4 DLT-based digital collections + +DLT-based digital collections can be digital artworks, digital music & movies, digital game props, digital tickets, etc. + +# 8 Information flows + +## 8.1 Overall information flow diagram + +The overall information flow diagram of the DLT-based digital collection services is shown in Figure 2. + +![Figure 2 – Information flows of the DLT-based digital collection services. The diagram illustrates the flow of information between four main roles: Digital collection user, Digital collection asset provider, Digital collection service platform, and DLT system, across five stages: Identity registration, Digital collection issuance, Initial selling, and Digital collection circulation.](1eadbbe42cfcac5c0023577110aec5e3_img.jpg) + +The diagram illustrates the information flows in the DLT-based digital collection service system. It is organized into four horizontal lanes representing different roles and five vertical columns representing different stages of the process. + +- Roles:** + - Digital collection user:** Includes 'Download client' and 'Identity registration'. + - Digital collection asset provider:** Includes 'Digital collection design' and 'Identity registration'. + - Digital collection service platform:** Includes 'Digital collection issuance' and 'Digital collection selling'. + - DLT system:** Includes 'Identity management smart contract' and 'Digital collection management smart contract'. +- Stages:** + - Identity registration:** Both 'Digital collection user' and 'Digital collection asset provider' perform identity registration. The 'DLT system' supports this via the 'Identity management smart contract'. + - Digital collection issuance:** The 'Digital collection service platform' handles issuance, supported by the 'DLT system'. + - Initial selling:** The 'Digital collection user' makes a 'Digital collection purchase', and the 'Digital collection service platform' handles 'Digital collection selling', both supported by the 'DLT system'. + - Digital collection circulation:** This stage includes 'Asset circulation', 'Trade', 'Transfer', 'Auction', and other activities ('... ..'). + +**Information Flow:** + +- The 'Digital collection user' (via 'Download client') and 'Digital collection asset provider' (via 'Digital collection design') both proceed to 'Identity registration'. +- From 'Identity registration', the flow goes to 'Digital collection issuance' (for the asset provider) and 'Digital collection purchase' (for the user). +- Both 'Digital collection purchase' and 'Digital collection issuance' lead to 'Digital collection selling'. +- 'Digital collection selling' leads to 'Asset circulation'. +- 'Asset circulation' leads to a group of activities: 'Trade', 'Transfer', 'Auction', and '... ..'. +- The 'DLT system' (specifically the 'Identity management smart contract' and 'Digital collection management smart contract') provides support across the 'Identity registration', 'Digital collection issuance', and 'Initial selling' stages. + +Figure 2 – Information flows of the DLT-based digital collection services. The diagram illustrates the flow of information between four main roles: Digital collection user, Digital collection asset provider, Digital collection service platform, and DLT system, across five stages: Identity registration, Digital collection issuance, Initial selling, and Digital collection circulation. + +F.751.10(23) + +**Figure 2 – Information flows of the DLT-based digital collection services** + +The DLT-based digital collection service system mainly includes digital collection users, digital collection asset providers, the digital collection service platform, and the DLT system. Its process mainly includes identity registration, digital collection issuance, initial selling, and digital collection circulation. Different roles involve different activities. + +- a) The digital collection users mainly involve downloading digital collection clients, performing identity registration, purchasing, and circulating digital collections. +- b) The digital collection asset provider is mainly involved in the design of digital collections, DLT identity registration, and the issuance of digital collections. +- c) The digital collection service platform mainly involves the issuance, sale, and circulation of digital collection assets. +- d) The DLT system mainly involves the execution of DLT identity management smart contracts, digital collection management smart contracts, etc. + +## 8.2 Information flows of the digital collection service platform + +From the perspective of the digital collection service platform side, the overall process of the digital collection service is described as below: + +- a) DLT identity registration +The digital collection service platform receives and completes the identity registration from the digital collection asset provider, and the digital collection user. +- b) Original review of the digital collections +The digital collection asset provider completes the design of the digital collections. The service platform completes the original review of the digital collections. +- c) Digital collection issuance +The service platform receives requests from the digital collection asset provider and completes the issuance of the digital collections. +- d) Digital collection selling +The service platform supports the initial selling of the digital collections. +- e) Digital collection circulation +The service platform supports the circulation of the digital collections, including transfers, auctions, selling and buying. + +## 8.3 Information flows of the digital collection user + +From the perspective of the digital collection user side, the overall process of the digital collection service is described as below: + +- a) Download the client +Digital collection users download the client from the service platform. The service platform provides and supports users to download the client. +- b) DLT identity registration +Digital collection users perform identity registration and real-name authentication based on the client. +- c) Digital collection purchase +Digital collection users purchase the digital collections from the client. +- d) Digital collection circulation +Based on the client, digital collection users can realize the circulation and transfer of digital collections. + +# **9 Functional requirements** + +## **9.1 Functional requirements of the DLT-based digital collection service client** + +The functional requirements of the DLT-based digital collection service client are as follows: + +- a) The functions of real-name authentication and registration of users are required, including new user registration, registered user restoration, and user cancellation. +- b) It is required to support the functions of mnemonic management, including generating mnemonic words, backup of mnemonic words, import of mnemonic words, export of mnemonic words and other functions. +- c) It is required to support the functions of private key management, including importing private keys, exporting private keys, etc. +- d) It is required to support the function of accepting digital collections, that is, users can accept and own the products after purchasing the digital collections. +- e) It is required to support the function of digital collection transfer. That is, after the user owns the digital collection, it can be transferred to other users, or transferred to other receiving addresses. +- f) It is required to support account management functions, including exporting private keys, changing account names, exporting mnemonics, viewing product lists and details, viewing address details, etc. +- g) It is required to support the function of querying transaction records lists for users to query transaction records. +- h) It is required to support the security setting function to allow users to change passwords, backup accounts, etc. + +## **9.2 Functional requirements of the DLT-based digital collection service platform** + +The functional requirements for the DLT-based digital collection service platform are as follows: + +- a) It is required to support the user's identity registration function on the platform, including the registration of individual users and the registration of corporate users. It is also required to support the log-off function of registered users on the platform, and deletion of user information. +- b) It is required to support the function of initializing the user's on-chain identity, including the initialization of the basic identity information of individual users and corporate users. +- c) It is required to support user account management functions, including generating public and private keys of user accounts in advance, maintaining the relationship between account addresses and real users, etc. +- d) It is required to support the function of originality review of DLT-based digital collections. That is, initial screening of digital collection originality, and filter and identify collections that may be infringing. +- e) It is required to support the function of registering and issuing DLT-based digital collections. Before the issuance, the issuance of the DLT-based digital collections is recommended to be reviewed, and the risks in laws, regulations, and regulatory policies are required to be evaluated. After the evaluation is passed, the issuance can be carried out. +- f) It is required to support the function of DLT-based digital collections display, and display user assets on the front-end page. It is also required to support the DLT-based digital collections information query function, and support users to query various types of the DLT-based digital collections, including transaction information, prices, etc., based on the unique digital collections identifier and other information. + +- g) It is required to support the function of issuing and selling DLT-based digital collections, that is, according to the issuer's pricing, the bidder who meets the conditions of the smart contract will obtain the ownership of the DLT-based digital collections under the contract logic. +- h) It is recommended to support the auction function, including the public welfare auction function. +- i) It is required to support the function of trading DLT-based digital collections, that is, reselling from one user to another user. +- j) It is required to support the function of transferring and gifting DLT-based digital collections, that is, users can transfer any DLT-based digital collections that belong to them to any legal address on the chain. +- k) It is recommended to support the compliance risk assessment of the entire life cycle of the DLT-based digital collections, including issuance, sale, transaction, transfer and gift, auction, etc. + +## **9.3 Functional requirements of the DLT system** + +#### **9.3.1 Functional requirements of the smart contracts** + +The functional requirements of the smart contracts are as follows: + +- a) It is required to support the registration and issuance of smart contracts as well as the triggering and execution of smart contracts. +- b) It is required to support the user to define the logic of a smart contract through some programming language, and then publish it on the DLT system and have it executed by the user's signature or other events to complete the logic of smart contract such as transaction settlement according to the logic of the smart contract terms. +- c) It is required to support the smart contract verification function. The upper layer application can encode the business execution rules into smart contract scripts according to the actual business requirements, and then deploy the smart contracts in the underlying DLT system, and the bookkeeping node is responsible for running them in a secure container environment and giving the running results. +- d) It is required to support the distributed multi-party consensus bookkeeping function. The participants verify the business through smart contracts and record the consensus results into the distributed ledger after consensus is completed, while the distributed ledger contains the transactions in data blocks by means of hash chains to reduce the possibility of data tampering. +- e) It is required to add a licensed credible institution to the consensus or validation node to ensure the stability and security of the parties' collaboration in the DLT system. + +#### **9.3.2 Functional requirements of the storage** + +The functional requirements of the storage are as follows: + +- a) It is required to support local database storage and file system storage, and cloud storage is recommended to be supported. +- b) Local storage is required to support hot and cold separation, database storage is required to support the mode of splitting library and table, cloud storage is required to support lossless expansion, and support unlimited expansion according to the cloud's clustering rules. +- c) It is recommended to use a dual database approach of chain database and state database for storage. The chain database saves the chain data, and all business data exists in this data, so that the data is traceable to the source. The state database is used to save the current state value to avoid traversing all transaction logs to calculate the current state value. The dual + +database solution can improve the speed of data query while preserving all the evidence of transaction history. + +#### **9.3.3 Functional requirements of the operation and management** + +The functional requirements of the operation and management are as follows: + +- a) It is required to provide a comprehensive, real-time, visualized operation and maintenance management system to quickly identify system status and meet operational management needs at multiple levels. +- b) It is required to provide visualization of service delivery. Visual management of the entire service delivery process, from code compilation, testing, acceptance to formal environment deployment. +- c) It is required to provide visualization of service metrics. Standardized hierarchical categorization of data, from infrastructure, upper layer components, application services to user side, based on the topology architecture of the application, collection of various metrics and unified presentation in one analysis platform. +- d) It is required to provide generic and efficient information collection components to display machine system information (CPU, memory, hard disk, network status, etc.), node usage status (node access, access time consumption, node health status, etc.) and business usage (business access, success rate, time consumption distribution, etc.) to the monitoring interface in real time to facilitate the management of the whole system. +- e) It is recommended to support the continuous auditing function, to audit the data operations and service operations in the DLT system. +- f) It is recommended to support the data posture presentation function. By extracting and analysing the data in the ledger, the system forms the current world status and historical records of the data, and then presents them through the interface, and monitors the current operation status of the system nodes. + +## **9.4 Performance requirements** + +The performance requirements are as follows: + +- a) It is required to analyse and pressure test using various models and support large concurrent processing capacity. +- b) In terms of fault tolerance, when node failure or fraud is detected, the system is required to automatically enable the algorithmic feature of Byzantine fault tolerance. +- c) It is required to support multiple load balancing of applications and databases, support a large number of users online and simultaneous operations, and that it will not cause a significant decrease in system responsiveness due to the growth of the number of users or the growth of the volume of information. +- d) The system deployment is recommended to be designed in a highly available mode to minimize and shorten the time of external service stoppage during regular maintenance and release to ensure that the system provides long time continuously available services. +- e) It is required to have high reliability to ensure the correctness of business logic under normal and extreme conditions, including but not limited to no single point of failure, fault recovery, disaster recovery, sudden user volume response, etc. +- f) It is required to have linear expansion and elastic scaling capability. The hardware equipment is recommended to adopt cluster or distributed deployment mode to achieve dynamic loading of nodes and support rapid horizontal expansion of nodes while eliminating single point of failure. It can also rely on cloud computing technology to realize the automatic elastic scaling of basic resources. + +## **9.5 Security requirements** + +#### **9.5.1 Identity authentication requirements** + +The identity authentication requirements are as follows: + +- a) It is required to support digital certificate identity and is recommended to support a centralized public key infrastructure (PKI) system. +- b) The authentication certificate between DLT nodes is recommended to adopt the international security certificate standard, and the process of issuing, storing, updating, and revoking the software development kit (SDK) certificate. +- c) Real-name authentication is required to be done for users in advance to ensure that all users participating in digital collections pass real-name authentication to ensure the authenticity of users, which can prevent behaviours harmful to business such as hoarding and speculation. + +#### **9.5.2 Data security requirements** + +The data security requirements are as follows: + +- a) It is required to support data encryption, digital signatures, and other technologies to ensure the confidentiality, integrity, and resistance to repudiation of data. +- b) It is required to support digital signatures through asymmetric encryption to ensure the tamper-evident nature of business requests and data during transmission. +- c) It is required to support the provision of regulatory keys to the supervisor of the application to reduce the risk of privacy leakage, while ensuring the auditability of data. +- d) It is required to support the storage of consistent data across nodes through a consensus mechanism. +- e) For the stored data records, it is required to be possible to ensure that the stored data records cannot be modified through self-checkability within the nodes and quasi-real-time multi-node data checking. + +#### **9.5.3 Privacy protection requirements** + +The privacy protection requirements are as follows: + +- a) It is required to protect the connections user information and DLT addresses. From the record storage of each node, the associated user information cannot be obtained. +- b) For the storage of user information, multi-layer protection such as permission control, access authentication and encrypted storage is required to be available. +- c) Privacy protection services are required to be provided for users, including schemes such as dual key pairs, ring signatures, and zero-knowledge proofs. +- d) It is required to support users to select corresponding services according to their actual needs, which are used to encrypt and de-link their transaction information. +- e) When it comes to the display of users' personal information (name, ID number, etc.), user privacy security is required to be ensured by hiding part of the key information, desensitization, etc. +- f) In some high-security scenarios, it is required to be possible to hash out the uploaded content through encryption algorithms to ensure user privacy. + +#### **9.5.4 System security requirements** + +The system security requirements are as follows: + +- a) In the process of system operation, the normal operation of the system is required to be ensured to prevent malicious attacks from causing business anomalies and unpredictable + +problems, including but not limited to service unavailability, business data errors, malicious data, leakage of user privacy and other problems. + +- b) It is required to ensure the security of the business system by setting the necessary network whitelist. +- c) On the system, all network requests are required to enter through a unified portal, and the system is recommended to be able to prevent attacks such as distributed denial of service (DDOS) attacks. +- d) In certain business scenarios with high security requirements, the system is required to be secured by means of authentication codes to avoid the impact of heavy traffic. + +#### **9.5.5 Content security requirements** + +The content security requirements are as follows: + +- a) It is required to ensure the content security of digital collections. The content of digital collections is diverse, with text, images, audio, and video, etc. These contents are recommended to be detected to prevent the uploading of contents related to pornography, terrorism, violence, etc. +- b) It is required to detect the content at the time of data submission by users through the detection capability of content security products. +- c) It is required to set up a blacklist mechanism. Platforms that submit malicious content are recommended to be blacklisted, in particular if after repeated occurrences. + +## Appendix I + +## Examples of the DLT-based digital collection services + +(This appendix does not form an integral part of this Recommendation.) + +### **I.1 DLT-based digital culture collections** + +Users can rent or purchase digital culture collections. There is a distinction between the procedure of purchase and the procedure of rental by the user. In the process of performing digital culture content rental, rental can be performed for all rights to the digital culture content, and rental can be performed only for some rights. For example, in the case of rental for exhibition, rental is performed only for exhibition rights, and in this process, authority is transferred only for exhibition rights. The asset provider needs an ID verification and digital culture contents registration process. The user has a process of checking IDs and searching for digital culture content and purchasing necessary digital culture content. In the distributed ledger technology, updates are performed on digital culture content issues. + +### **I.2 DLT-based digital music collections** + +Based on DLT, digital music can be issued limitedly on the DLT network, and they can be collected by music fans. + +### **I.3 DLT-based digital game assets** + +Based on DLT, digital game assets can be issued limitedly on the DLT network, and they can be collected by game players. The digital game assets include lands, characters, costumes, props, game points, etc. + +### **I.4 DLT-based digital sport assets** + +Based on DLT, digital sport assets can be issued limitedly on the DLT network, and they can be collected by sport fans. The digital sport assets include sport snap shots, wonderful moments, etc. + +### **I.5 DLT-based digital tickets** + +Based on DLT, digital tickets can be issued limitedly on the DLT network, and they can be collected by users. The digital tickets include concert tickets, sport tickets, etc. + +# Appendix II + +## Value of using DLT for digital collection services + +(This appendix does not form an integral part of this Recommendation.) + +### II.1 Guarantee authenticity, durability and continuity + +DLT can verify the authenticity of the digital collections, which effectively solves the long-term pain point of rampant counterfeiting in the industry. + +For antique or rare collection types, DLT can ensure their continuity and durability. + +### II.2 Ownership confirmation and information traceability + +DLT can realize the ownership confirmation and information traceability of digital collections. + +In the field of digital collections, piracy is prevalent. DLT can solve the problem of digital ownership by making it non-replicable so it can be bought and sold like tangible assets. Owners of digital collections can significantly enhance their sense of acquisition and protect the rights and interests of owners through the determination of ownership. + +### II.3 Enhance collection value through uniqueness and scarcity + +Through DLT, digital collections have the uniqueness and scarcity consistent with traditional collections, avoiding malicious additional issuance and unlimited copying of digital collections. + +DLT has made possible digital collections with rare attributes and enhanced their collection value. + +### II.4 Reduce transaction costs and improve circulation + +DLT can realize the separation of viewing rights and ownership, helping small and medium catalogue creators avoid the high cost of publishing collections offline. + +In terms of circulation channels, due to the large number of trading markets for DLT-based digital collections, online trading channels have been introduced into the traditional market. With its confirmation of rights, it greatly shortens the transaction process, reduces transaction costs, and broadens the circulation channels for digital collections. + +### II.5 Speed-up the construction of the digital collection trading market + +The promotion of DLT in the field of digital collections has broadened the product form in this field, effectively boosted the development of digital collections, and promoted the release of the value of digital collection commemoration and circulation. + +With DLT, the problems of forgery and the difficulty of circulation encountered in the transaction of digital collections have been solved, the commercial value of digital collections has been realized, and the market construction of digital collections has been accelerated. + +## Bibliography + +- [b-ITU-T F.751.0] Recommendation ITU-T F.751.0 (2020), *Requirements for distributed ledger system*. +- [b-ITU-T F.751.1] Recommendation ITU-T F.751.1 (2020), *Assessment criteria for distributed ledger technology platforms*. +- [b-ISO 22739] ISO 22739:2020, *Blockchain and distributed ledger technologies – Vocabulary*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.751.11-202309-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/F/T-REC-F.751.11-202309-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..abda52cbb1047d6649f89e40c898a1c33bed7267 --- /dev/null +++ b/marked/F/T-REC-F.751.11-202309-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:6f3b7e07231c0f3e116c99c493bdda98ecd52313b6735faa6cea23815cf3162b +size 7190 diff --git a/marked/F/T-REC-F.751.11-202309-I_PDF-E/raw.md b/marked/F/T-REC-F.751.11-202309-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..3ea2567e4f85f0b9abaf6f8cdd8a981bc2c87e3f --- /dev/null +++ b/marked/F/T-REC-F.751.11-202309-I_PDF-E/raw.md @@ -0,0 +1,319 @@ + + +Recommendation + +**ITU-T F.751.11 (09/2023)** + +SERIES F: Non-telephone telecommunication services + +Multimedia services + +--- + +**Performance test suite for distributed ledger +technology systems** + +![ITU logo](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +# ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.751.11 + +## Performance test suite for distributed ledger technology systems + +## Summary + +Recommendation ITU-T F.751.11 provides a performance test suite for distributed ledger technology (DLT) system based on assessment criteria proposed in Recommendations ITU-T F.751.1 and ITU-T F.751.6. This Recommendation specifies the basic principles and main dimensions of the performance testing for a DLT system and provides a suite of test cases that can help users quantitatively and objectively analyse the performance of the DLT system in different test environments comprehensively and find the most suitable path to improve performance. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.751.11 | 2023-09-13 | 16 | 11.1002/1000/15625 | + +## Keywords + +Blockchain, distributed ledger technology, DLT, performance, test suit. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2023 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-----------------------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Basic principles..... | 2 | +| 7 Main dimensions..... | 2 | +| 8 Test cases ..... | 2 | +| 8.1 Payment-related transaction under a small-scale network of a DLT system ..... | 3 | +| 8.2 Payment-related transaction under a large-scale network of a DLT system .. | 3 | +| 8.3 Evidence-based transaction under a small-scale network of a DLT system .. | 4 | +| 8.4 Evidence-based transaction under a large-scale network of a DLT system ... | 4 | +| 8.5 Query transaction..... | 5 | +| Bibliography..... | 6 | + + + +# Recommendation ITU-T F.751.11 + +## Performance test suite for distributed ledger technology systems + +## 1 Scope + +This Recommendation specifies a performance test suite for a distributed ledger technology system (DLT) system, which includes the basic principles and main dimensions of performance testing for a DLT system. This Recommendation is based on [ITU-T F.751.1] and [ITU-T F.751.6], and can be used as a guideline for DLT system performance testing and development. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T F.751.0] Recommendation ITU-T F.751.0 (2020), *Requirements for distributed ledger system*. + +[ITU-T F.751.1] Recommendation ITU-T F.751.1 (2020), *Assessment criteria for distributed ledger technology (DLT) platforms*. + +[ITU-T F.751.6] Recommendation ITU-T F.751.6 (2022), *Performance assessment methods for distributed ledger technology platforms*. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 consensus** [ITU-T F.751.0]: Agreement that a set of transactions is valid. + +**3.1.2 distributed ledger technology (DLT)** [ITU-T F.751.1]: Technology enabling large groups of nodes in distributed ledger networks to reach agreement and record information without the need for a central authority. + +NOTE – Adapted from [b-ITU-T TS FG DLT D1.1]. + +**3.1.3 smart contract** [ITU-T F.751.0]: Program written on the distributed ledger system that encodes the rules for specific types of distributed ledger system transactions in a way that can be validated, and triggered by specific conditions. + +NOTE – Adapted from [b-ITU-T TS FG DLT D1.1]. + +**3.1.4 transaction** [ITU-T F.751.0]: An incident or an operation that leads to a change in the status of a ledger, such as adding a record or equivalent exchange based on currency. + +**3.1.5 large-scale network** [b-ITU-T Y.3113]: A network or a set of networks, whose longest end-to-end path includes 16 or more relay nodes. + +### 3.2 Terms defined in this Recommendation + +None. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +DLT Distributed Ledger Technology + +## 5 Conventions + +None. + +# 6 Basic principles + +The design of the test suite should follow the following basic principles: + +- Reproducibility. Test cases should be able to run successfully in different experimental environments and not be limited to specific test environments. In environments with the same hardware configuration, the test results should be similar. Additional uncontrollable variables, which may prevent the reproducibility of test results, should not be introduced. +- Predictability. Through the design of the test suite, it is possible to infer the trend of DLT system performance changes in different scenarios, such as changes in DLT performance with changes in the number of nodes, the size of the transaction body or the amount of data on the chain. + +## 7 Main dimensions + +The design of the test suite should follow the following dimensions: + +- Type of transactions: the differences between different transaction types mainly include transaction logic and transaction payload. There are three main types of transaction, account fund transfer transactions, data storage transactions and query transactions. +- Network scale of the DLT system: the number of nodes participating in the consensus of the DLT system. The DLT system needs to be designed with different node scales according to a certain gradient. +- Duration of pressure: The duration of continuous pressure applied to the DLT system. + +**Table 1 – Test case dimensions and conditions** + +| Case No. | Transaction type | Network scale of DLT system | +|----------|-----------------------------|-----------------------------| +| Case 01 | Payment-related transaction | Small | +| Case 02 | | Large | +| Case 03 | Evidence-based transaction | Small | +| Case 04 | | Large | +| Case 05 | Query transaction | Small | + +## 8 Test cases + +### 8.1 Payment-related transaction under a small-scale network of a DLT system + +See Table 2. + +**Table 2 – Payment-related transaction under a small-scale network of a DLT system** + +| | | +|-------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test Case 01 | Payment-related transaction under a small-scale network of a DLT system | +| Test reference | Clause 7 of [ITU-T F.751.6] | +| Test purpose | Test the performance of the system for payment-related transactions by sending continuous pressure to a small-scale network of a DLT system. | +| Test workflow |

Step 1. Build a small-scale network of a DLT system where the number of participating consensus nodes can tolerate at least one malicious node.

Step 2. Generate a certain number of accounts on the DLT system, and deposit a certain amount of balance.

Step 3. Prepare sufficient payment-related transactions; the transfer amount of each transaction should be greater than zero, and the outgoing and incoming accounts should be different.

Step 4. Send transactions to the DLT system at a sufficiently fast speed, and after a certain duration, examine the performance test results. Multiple rounds of testing need to be conducted based on the actual circumstances to observe the overall performance changes in the system.

| +| Expected results |
  1. 1. The DLT system is running normally, and there are no abnormalities in the status of each node.
  2. 2. There are a certain number of accounts on the chain, each account owns a certain amount of balance.
  3. 3. The number of transactions is large enough and ensures the DLT system can be successfully executed.
  4. 4. There was no abnormality in the system during the test, and the results included in clause 7 of [ITU-T F.751.6] could be calculated.
| + +## 8.2 Payment-related transaction under a large-scale network of a DLT system + +See table 3. + +**Table 3 – Payment-related transaction under a large-scale network of a DLT system** + +| | | +|-------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test Case 02 | Payment-related transactions under a large-scale network of a DLT system | +| Test reference | Clause 7 of [ITU-T F.751.6] | +| Test purpose | Test the performance of the system for payment-related transactions by sending continuous pressure to a large-scale network of a DLT system. | +| Test workflow |

Step 1. Build a large-scale network of a DLT system with hundreds or thousands of participating consensus nodes.

Step 2. Generate a certain number of accounts on the DLT system, and deposit a certain amount of balance.

Step 3. Prepare sufficient payment-related transactions; the transfer amount of each transaction should be greater than zero, and the outgoing and incoming accounts should be different.

Step 4. Send transactions to the DLT system at a sufficiently fast speed, and after a certain duration, examine the performance test results. Multiple rounds of testing need to be conducted based on the actual circumstances to observe the overall performance changes in the system.

| +| Expected results |
  1. 1. The DLT system is running normally, and there are no abnormalities in the status of each node.
| + +**Table 3 – Payment-related transaction under a large-scale network of a DLT system** + +| | | +|-----------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test Case 02 | Payment-related transactions under a large-scale network of a DLT system | +| Test reference | Clause 7 of [ITU-T F.751.6] | +| |

2. There are a certain number of accounts on the chain; each account owns a certain amount of balance.

3. The number of transactions is large enough and ensures the DLT system can be successfully executed.

4. There was no abnormality in the system during the test, and the results included in clause 7 of [ITU-T F.751.6] could be calculated.

| + +## **8.3 Evidence-based transaction under a small-scale network of a DLT system** + +See Table 4. + +**Table 4 – Evidence-based transaction under a small-scale network of a DLT system** + +| | | +|-------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test Case 03 | Evidence-based transaction under a small-scale network of a DLT system | +| Test reference | Clause 7 of [ITU-T F.751.6] | +| Test purpose | Test the performance of the system for evidence-based transactions by sending continuous pressure to a small-scale network of a DLT system. | +| Test workflow |

Step 1. Build a small-scale network of a DLT system where the number of participating consensus nodes can tolerate at least one malicious node.

Step 2. Generate a certain number of accounts or addresses on the DLT system for storing data.

Step 3. Prepare sufficient notarized transactions, with each transaction being stored in a different account or address; the amount of information to be stored in each transaction should reach hundreds or thousands of bytes.

Step 4. Send transactions to the DLT system at a sufficiently fast speed, and after a certain duration, examine the performance test results. Multiple rounds of testing need to be conducted based on the actual circumstances to observe the overall performance changes in the system.

| +| Expected results |

1. The DLT system is running normally, and there are no abnormalities in the status of each node.

2. There are a certain number of accounts on the chain, each account owns a certain amount of balance.

3. The number of transactions is large enough and ensures the DLT system can be successfully executed.

4. There was no abnormality in the system during the test, and calculate the results included in clause 7 of [ITU-T F.751.6].

| + +### **8.4 Evidence-based transaction under a large-scale network of a DLT system** + +See Table 5. + +**Table 5 – Evidence-based transaction under a large-scale network of a DLT system** + +| | | +|-----------------------|-------------------------------------------------------------------------------------------------------------------------------------------| +| Test Case 04 | Evidence-based transaction under a large-scale network of a DLT system | +| Test reference | Clause 7 of [ITU-T F.751.6] | +| Test purpose | Test the performance of the system for evidence-based transactions by sending continuous pressure to a large-scale network of DLT system. | + +**Table 5 – Evidence-based transaction under a large-scale network of a DLT system** + +| Test Case 04 | Evidence-based transaction under a large-scale network of a DLT system | +|-------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test workflow |

Step 1. Build a large-scale network of a DLT system with hundreds or thousands of participating consensus nodes.

Step 2. Generate a certain number of accounts or addresses on the DLT system for storing data.

Step 3. Prepare sufficient notarized transactions, with each transaction being stored in a different account or address; the amount of information to be stored in each transaction should reach hundreds or thousands of bytes.

Step 4. Send transactions to the DLT system at a sufficiently fast speed, and after a certain duration, examine the performance test results. Multiple rounds of testing need to be conducted based on the actual circumstances to observe the overall performance changes in the system.

| +| Expected results |
  1. 1. The DLT system is running normally, and there are no abnormalities in the status of each node.
  2. 2. There are a certain number of accounts on the chain; each account owns a certain amount of balance.
  3. 3. The number of transactions is large enough and ensures the DLT system can be successfully executed.
  4. 4. There was no abnormality in the system during the test, and the results included in clause 7 of [ITU-T F.751.6] could be calculated.
| + +### 8.5 Query transaction + +See Table 6 + +**Table 6 – Query transaction** + +| Test Case 05 | Query transaction | +|-------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test reference | Clause 7 of [ITU-T F.751.6] | +| Test purpose | Test the performance of a DLT system for query transactions | +| Test workflow |

Step 1. Build a small-scale network of a DLT system where the number of participating consensus nodes can tolerate at least one malicious node.

Step 2. Generate a certain number of accounts on the DLT system, and deposit a certain amount of balance.

Step 3. Prepare sufficient query requests and randomly query the balances or stored information in different accounts.

Step 4. Send transactions to the DLT system at a sufficiently fast speed, and after a certain duration, examine the performance test results. Multiple rounds of testing need to be conducted based on the actual circumstances to observe the overall performance changes in the system.

| +| Expected results |
  1. 1. The DLT system is running normally, and there are no abnormalities in the status of each node.
  2. 2. There are a certain number of accounts on the chain; each account owns a certain amount of balance.
  3. 3. The number of transactions is large enough and ensures the DLT system can be successfully executed.
  4. 4. There was no abnormality in the system during the test, and the results included in clause 7 of [ITU-T F.751.6] could be calculated.
| + +## Bibliography + +- [b-ITU-T Y.3113] Recommendation ITU-T Y.3113 (2021), *Requirements and framework for latency guarantee in large-scale networks including the IMT-2020 network*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.751.13-202309-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg b/marked/F/T-REC-F.751.13-202309-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..c1629394c02f697f60ae954ad36bf274fa8082cb --- /dev/null +++ b/marked/F/T-REC-F.751.13-202309-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:3763acd7a0ed56aa30f3f90468c1fb0cb54573eb9045bca3eddf8976b4f0f41d +size 7219 diff --git a/marked/F/T-REC-F.751.13-202309-I_PDF-E/562f471e8153729557e6a4ee6343c32c_img.jpg b/marked/F/T-REC-F.751.13-202309-I_PDF-E/562f471e8153729557e6a4ee6343c32c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..63c7488a9269be5304841e59ae725a6d559c2851 --- /dev/null +++ b/marked/F/T-REC-F.751.13-202309-I_PDF-E/562f471e8153729557e6a4ee6343c32c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:a260a2e862108226e9da6fa6a938d61f4c475ca0fbeca32935cf8df229a12a8c +size 98257 diff --git a/marked/F/T-REC-F.751.13-202309-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg b/marked/F/T-REC-F.751.13-202309-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..09ebf68b9e7a89a5903d551ba8c49a5fa9cc66e8 --- /dev/null +++ b/marked/F/T-REC-F.751.13-202309-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ec4241ccf71a9dab9a4201000743166e35a505d33bd5e91ee5ac554ddf83bd91 +size 48605 diff --git a/marked/F/T-REC-F.751.13-202309-I_PDF-E/raw.md b/marked/F/T-REC-F.751.13-202309-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..5d48d9c9c185bc0168a00d72f449f98710a5b6b7 --- /dev/null +++ b/marked/F/T-REC-F.751.13-202309-I_PDF-E/raw.md @@ -0,0 +1,362 @@ + + +# Recommendation **ITU-T F.751.13 (09/2023)** + +SERIES F: Non-telephone telecommunication services +Multimedia services + +--- + +## **Framework and requirements for distributed ledger technology-based distributed power trading systems** + +![ITU logo](390120de4fe440c42fea8154fcaad334_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with a white grid pattern, overlaid by the letters 'ITU' in a bold, blue, sans-serif font. The globe is stylized with a white swoosh around it. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.751.13 + +# Framework and requirements for distributed ledger technology-based distributed power trading systems + +## Summary + +Recommendation ITU-T F.751.13 specifies the framework and requirements for the distributed power trading (DPT) system based on distributed ledger technology (DLT). The framework includes the infrastructure layer, the interface layer and the application layer. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.751.13 | 2023-09-13 | 16 | 11.1002/1000/15627 | + +## Keywords + +Distributed ledger technology, distributed power trading, framework, requirement. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2023 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|---------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Framework..... | 3 | +| 7 Participating entities for the DPT system ..... | 3 | +| 8 Requirements for infrastructure layer ..... | 4 | +| 9 Requirements for interface layer ..... | 4 | +| 10 Requirements for application layer..... | 4 | +| 10.1 Trading flow ..... | 4 | +| 10.2 Key functions..... | 5 | +| Bibliography..... | 8 | + + + +# Recommendation ITU-T F.751.13 + +## Framework and requirements for distributed ledger technology-based distributed power trading systems + +# 1 Scope + +This Recommendation specifies the framework and requirements for the development and design of the distributed power trading (DPT) system based on distributed ledger technology (DLT), including: + +- Framework; +- Participating entities for the DPT system; +- Requirements for the infrastructure layer; +- Requirements for the interface layer; and +- Requirements for the application layer. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T F.751.2] Recommendation ITU-T F.751.2 (2020), *Distributed ledger technology reference architecture – Architecture*. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 application** [b-ITU-T Y.2091]: A structured set of capabilities, which provide value-added functionality supported by one or more services. + +**3.1.2 blockchain** [b-ITU-T F.751.0]: A type of distributed ledger that is composed of digitally recorded data arranged as a successively growing chain of blocks with each block cryptographically linked and hardened against tampering and revision. + +**3.1.3 distributed ledger** [b-ITU-T X.1400]: A type of ledger that is shared, replicated, and synchronized in a distributed and decentralized manner. + +**3.1.4 distributed ledger technology (DLT)** [b-ITU-T F.751.1]: Technology enabling large groups of nodes in distributed ledger networks to reach agreement and record information without the need for a central authority. + +**3.1.5 settlement** [b-ITU-T Q.1743]: Payment of amounts resulting from the accounting process. + +**3.1.6 smart contract** [b-ITU-T X.1400]: A program written on a distributed ledger system which encodes the rules for specific types of distributed ledger system transactions in a way that can be validated, and triggered by specific conditions. + +**3.1.7 transaction** [b-ITU-T X.1400]: Whole of the exchange of information between nodes. A transaction is uniquely identified by a transaction identifier. + +### **3.2 Terms defined in this Recommendation** + +This Recommendation defines the following term: + +**3.2.1 quotation:** The process of providing a specific price or rate for the supply or purchase of electricity. It provides potential buyers or sellers with the pricing information necessary to evaluate and make informed decisions regarding electricity transactions. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-----|-------------------------------| +| API | Application Program Interface | +| DLT | Distributed Ledger Technology | +| DPT | Distributed Power Trading | +| RPC | Remote Procedure Call | +| SDK | Software Development Kit | + +# **5 Conventions** + +The following conventions are used in this Recommendation. + +- The keywords "**is required to**" indicate a requirement which must be strictly followed and from which no deviation is permitted, if conformance to this Recommendation is to be claimed. +- The keywords "**is recommended**" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. +- The keywords "**may optionally**" indicate an optional requirement which is permissible, without implying any sense of being recommended. This term is not intended to imply that the vendor's implementation must provide the option and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the specification. + +# 6 Framework + +As shown in Figure 1, this Recommendation specifies a framework for the DLT-based DPT system. + +![Figure 1: Framework for the DLT-based distributed power trading system. The diagram shows three stacked layers: Application layer (top), Interface layer (middle), and Infrastructure layer (bottom).](562f471e8153729557e6a4ee6343c32c_img.jpg) + +The diagram illustrates the framework for the DLT-based distributed power trading system, organized into three layers: + +- Application layer:** Contains six functional blocks arranged in a 2x3 grid: User registration and identity verification, Negotiation and quotation, Power trading matching, Smart contract signing, Settlement and clearing, and Transaction recording and auditing. +- Interface layer:** Contains three functional blocks arranged horizontally: User interface, Transaction interface, and Smart contract interface. +- Infrastructure layer:** Contains five functional blocks arranged in a 2x3 grid (with the bottom-right position empty): Smart contract, Consensus mechanism, Data privacy and security, Scalability and good performance, and Compatibility and interoperability. + +Figure 1: Framework for the DLT-based distributed power trading system. The diagram shows three stacked layers: Application layer (top), Interface layer (middle), and Infrastructure layer (bottom). + +F.751.13(23) + +**Figure 1 – Framework for the DLT-based distributed power trading system** + +The framework for the DLT-based DPT system includes the infrastructure layer, interface layer and application layer. + +- The infrastructure layer provides the DLT platform, ensuring a secure and trustworthy execution of power trading through smart contracts, consensus mechanisms, privacy protection and other capabilities. +- The interface layer interacts with the application layer and the infrastructure layer. It includes the user interfaces, transaction interfaces and contract interfaces. +- The application layer provides power trading management, including user identity management and the full lifecycle management of power trading. + +# 7 Participating entities for the DPT system + +The participating entities for the DPT system include power users, power generation companies and technical service providers. + +- **Power users:** They are consumers in the DPT system, including households, businesses and public institutions. They can purchase electricity through the power trading platform and choose the energy supply that suits their needs. +- **Power generation companies:** They are those who produce electricity and can be a traditional power generation facility, renewable energy power plant or distributed energy system. Power generation companies provide electricity resources according to market demand and trading rules. They need to access the blockchain network and execute electricity transactions through smart contracts. + +- **Technical service providers:** They provide the development, deployment and maintenance of blockchain technology platforms to ensure the performance, security and reliability of the power trading platform. Technology service providers are also responsible for the development and implementation of smart contracts, ensuring automated execution of transactions and enforcement of rules. + +# 8 Requirements for infrastructure layer + +The infrastructure layer provides the DLT platform. The requirements for the DLT platform can refer to [ITU-T F.751.2], Reference framework for distributed ledger technologies. + +- **Smart contracts:** It is required to handle the business logic about the power trading through smart contracts, including negotiation and quotation, power trading matching, settlement and clearing. +- **Consensus mechanism:** It is required to verify and validate the validity of transactions through the consensus mechanism. +- **Data privacy and security:** It is required to provide effective authentication and access control mechanisms to prevent unauthorized access and malicious behaviours. In addition, the system should have a flexible data sharing mechanism to ensure that participants can control the use and scope of sharing their data. +- **Scalability and good performance:** It is required to be able to handle a large number of transactions and maintain fast confirmation and settlement of transactions. +- **Compatibility and interoperability:** It is required to allow seamless integration with existing energy systems and standard interfaces. The system should be able to interoperate with other DLT platforms to facilitate cross-platform transactions and collaboration. + +# 9 Requirements for interface layer + +The interface layer is required to observe the following rules: + +- **Multiple types of interfaces:** It is recommended to provide multiple types of interfaces, including but not limited to the RPC, API and SDK. +- **Permission management:** It is required to control the access permissions of interfaces for different users. +- **Classification of interface functions:** It is required to provide user interfaces, smart contract interfaces and transaction interfaces in the interface management. + +# 10 Requirements for application layer + +### 10.1 Trading flow + +The complete process for DLT-based DPT is recommended to include the stages shown in Figure 2. + +![Flowchart of the process for DLT-based distributed power trading. The steps are: 1. User registration and identity verification, 2. Negotiation and quotation, 3. Power trading matching, 4. Smart contract signing, 5. Settlement and clearing, and 6. Transaction recording and auditing. There are two decision diamonds: 'Match successful or not' after step 3, which loops back to step 2 if not successful, and 'Safely verification pass or not' after step 4, which leads to step 6 if not passed.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +``` + +graph TD + 1[1. User registration and identity verification] --> 2[2. Negotiation and quotation] + 2 --> 3[3. Power trading matching] + 3 --> D1{Match successful or not} + D1 -- No --> 2 + D1 -- Yes --> 4[4. Smart contract signing] + 4 --> D2{Safely verification pass or not} + D2 -- No --> 6[6. Transaction recording and auditing] + D2 -- Yes --> 5[5. Settlement and clearing] + 5 --> 6 + +``` + +F.751.13(23) + +Flowchart of the process for DLT-based distributed power trading. The steps are: 1. User registration and identity verification, 2. Negotiation and quotation, 3. Power trading matching, 4. Smart contract signing, 5. Settlement and clearing, and 6. Transaction recording and auditing. There are two decision diamonds: 'Match successful or not' after step 3, which loops back to step 2 if not successful, and 'Safely verification pass or not' after step 4, which leads to step 6 if not passed. + +**Figure 2 – Process for DLT-based distributed power trading** + +- **Stage 1:** User registration and identity verification. The power generation companies and users are required to register, and then they can trade on the platform after passing the registration review. +- **Stage 2:** Negotiation and quotation. Power generation companies and power users provide the electricity prices and electricity consumption during the trading cycle. +- **Stage 3:** Power trading matching. The DPT platform performs transaction matching according to the quotation generated in Stage 2. +- **Stage 4:** Smart contract signing. Both the power generation company and the power user shall sign the smart contract. +- **Stage 5:** Settlement and clearing. Automate the settlement and clearing process of transactions, ensuring secure settlement and clearing of transaction funds. +- **Stage 6:** Transaction recording and auditing. Record transaction data and auditing information to provide transaction traceability and auditability. + +### 10.2 Key functions + +#### 10.2.1 User registration and identity verification + +It is required to ensure that only authorized users can participate in power trading and protect the system from unauthorized access and malicious activities. + +- **Identity verification:** It is recommended to implement decentralized user identity verification using blockchain technology, verifying identities through users' digital credentials and public key authentication. +- **Distributed identity management:** It is required to store user identity data on the DLT platform to ensure identity security and trustworthiness. +- **Privacy protection:** It may optionally provide anonymous transaction functions to protect user privacy. + +### 10.2.2 Negotiation and quotation + +The power generation companies or power users issue a request for power trading, and the request is signed by the customer and then broadcast in the power trading system. + +- **Bilateral quotation:** It is required that power generation companies and users submit the electricity price and electricity for the next trading cycle to the trading platform. +- **Digital signature:** It is required that the transaction requests are digitally signed by the power users or power generation companies before transaction broadcasting. +- **Transaction broadcasting:** It is required to broadcast the transaction data in the DLT network, include but not limited to user ID, transaction time, transaction volume and transaction price. + +#### 10.2.3 Power trading matching + +This stage is to achieve effective matching between power users and the generation companies, which can optimize power supply-demand balance and improve the utilization efficiency of energy. + +- **Matching algorithm:** It is required to design and implement supply-demand matching algorithms based on smart contracts, considering the preferences, conditions and priorities of power suppliers and demand-side participants to ensure the best matching results. +- **Real-time data updates:** It is required to keep data updated in real-time, including electricity market prices, supply capacity and demand forecasts, to support accurate matching decisions. +- **Decentralized transaction matching:** It is required to utilize the decentralized nature of DLT to eliminate traditional intermediaries and enable direct transaction matching between supply and demand participants, reducing transaction costs and improving efficiency. + +#### 10.2.4 Smart contract signing + +At this stage, the power users and the generation companies need to sign the contract with their private keys in DLT. + +- **Security verification:** It is required to perform a security verification of the smart contract signed by the power generation company and the power user. +- **Contract content:** It is required to define the transaction period, transaction electricity, settlement method, settlement electricity price and liability for breach of smart contracts. +- **Automatic execution:** It is required to automatically execute smart contracts based on validated transaction requests, facilitating power exchange between suppliers and demand-side participants. + +#### 10.2.5 Settlement and clearing + +At this stage, automatic settlement and clearing are realized through smart contracts. + +- **Automatic settlement:** It is required to automate the transaction settlement process based on smart contracts, including determining payable amounts, initiating payments and fund transfers, reducing manual intervention and errors, and ensuring accurate and trustworthy transactions. + +- **Automatic clearing:** It is required to establish an automatic clearing mechanism through smart contracts to periodically reconcile and clear transaction data and settlement results, ensuring transaction accuracy and completeness. +- **Settlement methods:** It is required to define the calculation and settlement methods for transaction fees and service charges, ensuring transparency and reasonableness of transaction costs. Determine appropriate settlement cycles to meet participants' settlement. +- **Cross-chain settlement support:** It is recommended to support cross-chain transaction, enabling fund transfers and settlements between different DLT platforms through cross-chain technologies, increasing transaction flexibility and interoperability. + +#### 10.2.6 Transaction recording and auditing + +Store transaction records in the DLT, ensuring transaction traceability and transparency. + +- **Transaction records:** It is required to record key information of transactions on the DLT, including transaction time, participating parties, transaction quantities and transaction results, ensuring accurate recording and storage of transactions. +- **Audit logs:** It is required to record key events and operations during transaction execution, including user access, transaction execution and system configuration changes, to support secure auditing and traceability. +- **Privacy protection:** It is required to implement appropriate data encryption and privacy protection measures to safeguard transaction data and participants' privacy information. + +## Bibliography + +- [b-ITU-T F.751.0] Recommendation ITU-T F.751.0 (2020), *Requirements for distributed ledger systems*. +- [b-ITU-T F.751.1] Recommendation ITU-T F.751.1 (2020), *Assessment criteria for distributed ledger technology platforms*. +- [b-ITU-T Q.1743] Recommendation ITU-T Q.1743 (2016), *IMT-Advanced references to Release 11 of LTE-Advanced evolved packet core network*. +- [b-ITU-T Y.2091] Recommendation ITU-T Y.2091 (2011), *Terms and definitions for Next Generation networks*. +- [b-ITU-T X.1400] Recommendation ITU-T X.1400 (2020), *Terms and definitions for distributed ledger technology*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| 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It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.751.22 + +# Financial distributed ledger technology application guideline + +## Summary + +Recommendation ITU-T F.751.22 specifies the application guideline of financial distributed ledger technology (DLT). It provides: + +- General principles from five aspects; +- Reference architecture from both the participant and conceptual architecture views; +- Technical requirements, including functionality, performance, security, governance, maintenance, auditability and interoperability; +- Use cases in trade finance and supply chain finance to illustrate how DLT can be used more reasonably and effectively for financial applications according to this guideline. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.751.22 | 2024-06-13 | 16 | 11.1002/1000/15927 | + +## Keywords + +DLT, financial application, guideline, reference architecture. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2024 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|--------------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 3 | +| 6 General principles ..... | 3 | +| 7 Reference architecture ..... | 3 | +| 7.1 General ..... | 3 | +| 7.2 Participant view ..... | 4 | +| 7.3 Conceptual architecture view ..... | 5 | +| 8 Technical requirements..... | 7 | +| 8.1 Functional requirements ..... | 7 | +| 8.2 Performance requirements ..... | 8 | +| 8.3 Security requirements ..... | 9 | +| 8.4 Governance requirements ..... | 10 | +| 8.5 Maintenance requirements..... | 10 | +| 8.6 Auditability requirements ..... | 10 | +| 8.7 Interoperability requirements ..... | 11 | +| Appendix I – DLT use cases in financial services ..... | 12 | +| I.1 Trade finance ..... | 12 | +| I.2 Supply chain finance ..... | 18 | +| Bibliography..... | 23 | + + + +# Recommendation ITU-T F.751.22 + +## Financial distributed ledger technology application guideline + +# 1 Scope + +This Recommendation specifies the application guideline for financial distributed ledger technology (DLT). It includes general principles, reference architecture and technical requirements for the application of financial DLT. + +This Recommendation is intended for use as a guideline by the interested parties for the financial DLT application. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 account** [b-ITU-T X.1400]: Representation of an entity whose data is recorded on a distributed ledger. + +**3.1.2 address** [b-ITU-T X.1400]: Identifier for entity(s) performing transactions or other actions in a blockchain or distributed ledger network. + +**3.1.3 application** [b-ITU-T Y.2091]: A structured set of capabilities, which provide value-added functionality supported by one or more services. + +**3.1.4 asset** [b-ITU-T X.1400]: Representation of value. + +**3.1.5 consensus** [b-ITU-T X.1400]: Agreement that a set of transactions is valid. + +**3.1.6 consensus mechanism** [b-ITU-T X.1400]: Rules and procedures by which consensus is reached. + +**3.1.7 digital signature** [b-ITU-T X.800]: Data appended to, or a cryptographic transformation (see cryptography) of a data unit that allows a recipient of the data unit to prove the source and integrity of the data unit and protect against forgery, e.g., by the recipient. + +**3.1.8 distributed ledger** [b-ITU-T X.1400]: A type of ledger (see clause 3.1.12) that is shared, replicated, and synchronized in a distributed and decentralized manner. + +**3.1.9 distributed ledger technology (DLT)** [b-ISO 22739]: Technology that enables the operation and use of distributed ledgers. + +**3.1.10 DLT oracle** [b-ITU-T X.1400]: A service that supplies information to a distributed ledger using data from outside of the distributed ledger system. + +**3.1.11 entity** [b-ISO 22739]: Item inside or outside an information and communication technology system, such as a person, an organization, a device, a subsystem, or a group of such items that has recognizably distinct existence. + +**3.1.12 ledger** [b-ITU-T X.1400]: Information store that keeps final and definitive (immutable) records of transactions. + +**3.1.13 node** [b-ITU-T X.1400]: Device or process that participates in a distributed ledger network. +NOTE – A node can store a complete or partial replica of the distributed ledger. + +**3.1.14 off-chain** [b-ISO 22739]: Related to a DLT system, but located, performed or run outside that DLT system. + +**3.1.15 on-chain** [b-ISO 22739]: Located, performed or run inside a DLT system. + +**3.1.16 smart contract** [b-ITU-T X.1400]: A program written on a distributed ledger system which encodes the rules for specific types of distributed ledger system transactions in a way that can be validated, and triggered by specific conditions. + +**3.1.17 transaction** [b-ITU-T X.1400]: Whole of the exchange of information between nodes. A transaction is uniquely identified by a transaction identifier. + +## 3.2 Terms defined in this Recommendation + +None. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +ACID    Atomicity Consistency Isolation Durability + +AML    Anti-Money Laundering + +API    Application Programming Interface + +CA    Certificate Authority + +CFT    Combating the Financing of Terrorism + +DApp    Decentralized Application + +DAV    Digital Asset Voucher + +DID    Decentralized Identifier + +DLT    Distributed Ledger Technology + +EDD    Enhanced Due Diligence + +HSM    Hardware Security Module + +KYC    Know Your Customer + +ROM    Read-Only Memory + +RPO    Recovery Point Objective + +RTO    Recovery Time Objective + +SDD    Simplified Due Diligence + +SE    Secure Element + +TEE    Trusted Execution Environment + +TLS    Transport Layer Security + +# 5 Conventions + +In this Recommendation: + +- The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this Recommendation is to be claimed. +- The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +# 6 General principles + +The general principles for financial DLT applications are as follows: + +- **Problem-oriented:** How financial DLT applications address industry pain points and enable the financial DLT application to profoundly serve the real economy is critical. There is no one-size-fits-all technology, and the same is true for financial DLT applications. The financial sector should consider market development, risk control, regulatory compliance requirements and put equal emphasis on innovation and management to adequately realize the enabling potential of financial DLT applications. +- **Long-term evolution:** Recognizing the systematic, long-term and complex characteristics of DLT application, it is necessary to combine the advantages of DLT inheritance evolution on the basis of traditional technology architecture, especially to meet the high-security requirements of the financial industry level protection baseline and anti-quantum algorithm attack protection, to realize the long-term evolution. +- **Interconnection:** Legacy IT systems often form information silos and systems of various organizations commonly form closed loops. Financial DLT systems need to interact with these systems to enable data exchange such as identity authentication and compliance checks, thus supporting the trusted execution and value transfer of financial DLT services. At the same time, the universality of financial DLT services and technical templates can only be guaranteed if the interconnection of the operating environments is implemented, enabling one-time development and multiple reuse across institutions. +- **Open sharing:** To meet diverse needs of financial DLT business, it is necessary to lower the barrier for the development and use of DLT, encourage the whole society to participate in the development and application of relevant business and technology templates, and establish a rich, efficient and convenient financial DLT business open platform like the mobile application market. Various institutions offer financial DLT services on this platform, which will be integrated and used as building blocks according to the wishes of users to achieve openness, co-construction and sharing. +- **Compliance:** Financial DLT applications should respect and comply with the regulatory policies of various jurisdictions and not jeopardize monetary sovereignty, monetary policy independence and the financial system. At the same time, it should have excellent governance capabilities and provide an auditable accountability mechanism to ensure the sound and healthy development of the financial business. + +# 7 Reference architecture + +## 7.1 General + +This Recommendation provides financial DLT systems reference architecture using a participant view and a conceptual architecture view. + +## 7.2 Participant view + +#### 7.2.1 General + +The financial DLT system participant view references Figure 6 of [b-ISO 23257], as shown in Figure 1 below. This Recommendation specifies seven type of participants: DLT users, DLT administrators, DLT providers, DLT developers, DLT governors, DLT auditors, and financial DLT regulators (see clause 9.2 of [b-ISO 23257]). + +![Figure 1 – Financial DLT system participant view diagram](e6df2733626a85205c1db682e6259c46_img.jpg) + +The diagram illustrates the participant view for a financial DLT system, organized into seven vertical columns representing different participant roles. The first column, 'DLT developers', contains two hexagonal subroles: 'DLT application developers' and 'DLT system developers'. The second column, 'DLT administrators', is a single rectangular box. The third column, 'DLT users', is a single rectangular box. The fourth column, 'DLT providers', contains three hexagonal subroles: 'DLT system operators', 'DLT node operators', and 'DLT application operators'. The fifth column, 'DLT governors', is a single rectangular box. The sixth column, 'DLT auditors', is a single rectangular box. The seventh column, 'Financial DLT regulators', is a single rectangular box. The label 'F.751.22(24)' is located at the bottom right of the diagram. + +Figure 1 – Financial DLT system participant view diagram + +**Figure 1 – Financial DLT system participant view** + +For the financial industry, financial DLT regulations are critical and need to be carefully considered and complied with. + +#### 7.2.2 DLT users + +A DLT user is a role that uses a DLT solution. This may represent an individual, an organization, a device or a system. + +#### 7.2.3 DLT administrators + +DLT administrators perform specific administrative activities (in particular for security configuration). + +#### 7.2.4 DLT providers + +##### 7.2.4.1 General + +A DLT provider is a role that may own and operate one or more nodes within the DLT system and the DLT network. Subroles include: DLT system operators, DLT node operators and DLT application operators. + +##### 7.2.4.2 DLT system operators + +A DLT system operator is a role that administers and operates the physical and virtual systems and networks that host and run the components of the DLT systems and platforms within the DLT nodes. + +##### 7.2.4.3 DLT node operators + +A DLT node operator is a role that administers and operates one or more nodes within a DLT system for a DLT provider. + +##### **7.2.4.4 DLT application operators** + +A DLT application operator is a role that administers, owns, operates and maintains DLT application systems to provide DLT services directly or indirectly to DLT users. + +#### **7.2.5 DLT developers** + +##### **7.2.5.1 General** + +A DLT developer is a role that creates and maintains the code and specialized devices for any part or implementation of a DLT system or application. There are two subroles for DLT developers: DLT application developers and DLT system developers. + +##### **7.2.5.2 DLT application developers** + +A DLT application developer is a role that creates and maintains DLT applications and smart contracts that run in conjunction with DLT systems. + +##### **7.2.5.3 DLT system developers** + +A DLT system developer is a role that develops physical and virtual systems that host and run components of DLT systems and platforms in DLT nodes. + +#### **7.2.6 DLT governors** + +DLT governors play roles which perform governance of the entire DLT systems (and networks), but not necessarily the entire DLT solution. + +#### **7.2.7 DLT auditors** + +DLT auditors ensure that policies, governance and regulation are adhered to in DLT systems. + +#### **7.2.8 Financial DLT regulators** + +Financial DLT regulators play the role of enforcing regulations on combating the financing of terrorism (CFT), anti-money laundering (AML), anti-tax evasion and adherence to the principles of financial market infrastructure. + +### **7.3 Conceptual architecture view** + +#### **7.3.1 General** + +The financial DLT system conceptual architecture view references Figure 1 of [ITU-T F.751.2], as shown in Figure 2 below. It includes six layers: resource layer, protocol layer, application layer, operation and maintenance layer, external interaction management layer and extension layer (see clause 6 of [ITU-T F.751.2]). + +This Recommendation specifies the functional modules as following: + +- financial trusted hardware module in the resource layer; +- financial audit and regulatory module in the protocol layer; +- cross-border payment module, trade finance module, digital notes module and institutional reconciliation module in the application layer; +- financial network monitor module, financial system monitor module and financial transaction monitor module in the operation and maintenance layer; +- financial cross-chain module and financial layer-2 network module in the external interaction management layer. + +It also updates relevant existing modules of the high-level conceptual architecture of DLT (clause 6 of [ITU-T F.751.2]), which include consensus module, ledger management module, account or + +decentralized identifier (DID) module, cryptography module in the protocol layer, node management module, network management module, data integrity and privacy utility module in the resource layer. + +![Figure 2 – Financial DLT system conceptual architecture view. The diagram shows a layered architecture with four main vertical columns. From left to right: Operation and maintenance, Application, Protocol, and External interaction management. The Application layer includes Cross-border payment, Trade finance, DApp(s), Digital notes, and Institutional reconciliation, supported by Runtime, Lifecycle, and Devtool. The Protocol layer includes Governance and compliance (Financial audit and regulatory, Account/DID, Right management), Consensus, Ledger management, Messaging, and Crypto. The Resources layer includes Node management, Financial trusted hardware, Storage management, Data integrity and privacy util, and Network management. External interaction management includes Financial cross-chain module, Financial layer-2 network, and External resource management. Extensions include Side chain, Off chain, Multi chain, Internal extensions, and others. Monitoring components include Financial network monitor, Financial system monitor, and Financial transaction monitor. Reference F.751.22(24) is noted at the bottom right.](007b053fe94a8348f75128a584503fd0_img.jpg) + +Figure 2 – Financial DLT system conceptual architecture view. The diagram shows a layered architecture with four main vertical columns. From left to right: Operation and maintenance, Application, Protocol, and External interaction management. The Application layer includes Cross-border payment, Trade finance, DApp(s), Digital notes, and Institutional reconciliation, supported by Runtime, Lifecycle, and Devtool. The Protocol layer includes Governance and compliance (Financial audit and regulatory, Account/DID, Right management), Consensus, Ledger management, Messaging, and Crypto. The Resources layer includes Node management, Financial trusted hardware, Storage management, Data integrity and privacy util, and Network management. External interaction management includes Financial cross-chain module, Financial layer-2 network, and External resource management. Extensions include Side chain, Off chain, Multi chain, Internal extensions, and others. Monitoring components include Financial network monitor, Financial system monitor, and Financial transaction monitor. Reference F.751.22(24) is noted at the bottom right. + +**Figure 2 – Financial DLT system conceptual architecture view** + +#### 7.3.2 Resource layer + +The infrastructure provides the operating environment and basic components required for the normal operation of a distributed ledger system. + +The financial trusted hardware module provides strong privacy and high-performance on-chain data privacy protection services and security enhancement services. It provides full link and lifetime privacy protection for sensitive transaction data and provide financial-level security enhancement services for DLT. + +#### 7.3.3 Protocol layer + +The protocol layer consists of governance and compliance module, consensus module, ledger management module and utility module. + +The financial audit module provides functions such as security audit, record audit and data change audit. + +The financial regulation module provides functions such as AML, CFT, anti-fraud and anti-tax evasion. + +#### 7.3.4 Application layer + +Based on the runtime, lifecycle, and development tool (devtool) management, decentralized application (DApp) is built to serve different business requirements in a distributed network environment. + +The financial DLT application module provides functions such as cross-border payment, trade finance, institutional reconciliation and digital notes. + +#### 7.3.5 Operation and maintenance layer + +The operation and maintenance layer includes various libraries such as logging, monitoring, node or network management and scaling libraries. + +The financial network monitor module provides functions to monitor the overall situation of underlying networks to support the requirements of financial DLT application services. + +The financial system monitor module provides functions to monitor the overall situation of financial DLT systems to support the normal operation of business. + +The financial transaction monitor module provides functions to monitor relevant transaction information in order to comply with the requirements. + +#### **7.3.6 External interaction management layer** + +A DLT system with the open network assumption is able to interact or interoperate with external systems. + +The financial cross-chain module supports efficient collaboration and deep integration of financial businesses with other businesses. + +The financial layer-2 network module supports the high concurrency and strong security requirements of financial operations, as well as business, privacy and regulatory compliance requirements. + +#### **7.3.7 Extension layer** + +Extension components of a DLT system are designed to address different data interoperability requirements. + +# **8 Technical requirements** + +### **8.1 Functional requirements** + +#### **8.1.1 Node communication requirements** + +The node communication requirements for financial DLT are as follows: + +- It is recommended to connect the nodes via leased lines, and the communication links are encrypted by TLS protocol to meet the requirements of financial business. +- It is recommended to deploy nodes in data centres that comply with relevant financial requirements and standards. +- It is recommended to ensure the timeliness of financial data transmission with low latency. + +#### **8.1.2 Consensus mechanism requirements** + +The consensus mechanism requirements for financial DLT are as follows: + +- It is recommended to support flexible consensus algorithms and select different consensus algorithms based on the specific requirements of the financial business and network organization to achieve the desired financial consensus mechanism. +- It is recommended to support and ensure the finality of financial transaction settlement using an auditable consensus process so that the consensus records are tamper-proof and the safety of funds is guaranteed. + +#### **8.1.3 Ledger management requirements** + +The ledger management requirements for financial DLT are as follows: + +- It is required to establish comprehensive backup procedures, emergency response plans, disaster recovery strategies and mechanisms for seamless fail-over in case of disruption. +- It is required to support financial transactions with ACID (atomicity consistency isolation durability) properties, thereby ensuring the safety of funds. +- It is recommended not to store financial sensitive data in the ledger. + +- It is required to leverage measures such as encryption or desensitization to protect financial sensitive data in the ledger. + +#### **8.1.4 Smart contract requirements** + +The smart contract requirements for financial DLT are as follows: + +- It is required to ensure the consistency between financial legal documents and contracts. +- It is recommended to conduct audits based on different business needs and regulatory requirements to ensure the safety of financial operations and client funds. +- It is required to conduct code review and vulnerability scan before deployment. +- It is recommended to oversee the entire process before, during and after deployment and implementation, with the option to support compliance reporting and alert functions. +- It is recommended to ensure that the execution process and results of the contract are in line with expectations and verifiable. +- It is recommended to support automatic triggers and executions as long as they satisfy the specified conditions without the possibility of human interference. +- It is recommended to build version control rules and upgrade control rules. + +#### **8.1.5 Cryptographic mechanism requirements** + +The cryptographic mechanism requirements for financial DLT are as follows: + +- It is recommended to comply with financial industry best practices and related standards. +- It is recommended to effectively manage the lifecycle of encryption keys and other keys relevant to the financial encryption process, including key generation, distribution, rotation, storage and disposal in a secure and organized manner. + +#### **8.1.6 Trusted hardware requirements** + +The trusted hardware requirements for financial DLT are as follows: + +- It is recommended to provide a secure boot capability, including a tamper-proof hardware boot root and a secure boot chain that is verifiable step by step from on chip ROM of trusted components (such as trusted execution environment (TEE), trust platform module (TPM)) to the distributed ledger node kernel. +- It is recommended to provide firmware security upgrade capability, including verification of the integrity of the firmware upgrade packages and the legitimacy of the source. +- It is recommended to provide firmware rollback prevention to ensure the security of financial processes and the safety of funds. After a successful firmware upgrade, firmware rollback is prohibited, except in special scenarios, to prevent the firmware from being rolled back to the version with the vulnerability. +- It is recommended to leverage TEE, secure element (SE), hardware security module (HSM), etc. to enhance the security of financial processes and the safety of funds. + +## **8.2 Performance requirements** + +#### **8.2.1 Concurrency requirements** + +The concurrency requirements for financial DLT are as follows: + +- It is recommended to support high concurrency based on the financial business requirements, enabling fast and correct response to requests in various financial business scenarios. +- It is recommended to support different high concurrency solutions without compromising the availability and efficiency of financial businesses and the safety of funds. + +- It is recommended to support different contract invocation modes, such as passing a large number of parameters in the form of a file or files, in order to support the financial scenario of batch payments. + +#### **8.2.2 Stability requirements** + +The stability requirements for financial DLT are as follows: + +- It is recommended to resist failures caused by improper operations in specific financial business processes. +- It is recommended to complete planned system upgrades within the specified duration without disrupting business operations. +- It is recommended to meet the financial business RTO time limit requirements to ensure minimal downtime in case of a system failure. +- It is recommended to meet financial business RPO requirements to ensure minimal data loss in the event of a system failure. +- It is required to prevent loss of funds due to concurrency and distributed storage. + +### **8.3 Security requirements** + +#### **8.3.1 Identity requirements** + +The identity requirements for financial DLT are as follows: + +- It is required to adopt strict know your customer (KYC) admission mechanisms to ensure that only eligible individuals or entities gain access. +- It is recommended to support identity recovery functions, on the premise of ensuring the safety of funds. +- It is recommended to support cross-platform and cross-chain identity authentication, such as DID solutions, to satisfy the financial business requirements, such as AML and Combating the Financing of Terrorism (CFT). +- It is recommended to support users to change the DID identifier at any time as needed to prevent illegal tracking of user financial transactions or unauthorized user financial portraits through the DID. +- It is required to provide a blacklisting mechanism to effectively block transactions involving malicious or illegal accounts. + +#### **8.3.2 Key management requirements** + +The key management requirements for financial DLT are as follows: + +- It is recommended to support the use of hardware wallets, especially with SE, for secure key storage. +- It is recommended to separate hot wallets and cold wallets to enhance security, including securely storing the private key that control the funds in an offline environment to reduce the risk of cyberattacks. +- It is recommended to implement multilevel permission controls within the wallet, including multisignature capabilities based on the amount of funds involved and different financial business scenarios. +- It is recommended to have a well-defined mechanism and solution to address critical loss situations to ensure the safety of funds. + +#### **8.3.3 Privacy protection requirements** + +The privacy protection requirements for financial DLT are as follows: + +- It is recommended to support for configuring different privacy policies based on different financial business scenarios, such that only essential information needs to be disclosed. +- It is recommended to support TEE-based ledger encryption mechanisms, and decrypt and access data in the TEE only after authorization is obtained. +- It is recommended to prevent the aggregation and analysis of different data sets that could lead to financial privacy breaches. +- It is recommended not to store the critical financial privacy information on the ledgers in plain text or encrypted form, but in a hashed or anonymized format to protect financial sensitive information from exposure. +- It is required to implement compliance reviews of data without compromising data privacy. + +### **8.4 Governance requirements** + +The governance requirements for financial DLT are as follows: + +- It is recommended to provide regular monitoring of the operational status of the DLT, with a particular focus on any anomalies related to the safety of funds. Timely response and recovery procedures are in place to address such financial issues. +- It is recommended to customize user-level authorization based on varying KYC and AML requirements to ensure compliance with different regulatory standards. +- It is recommended to support different and flexible authorization solutions, such as simplified due diligence (SDD) and enhanced due diligence (EDD), to meet financial business requirements and ensure the safety of funds. +- It is recommended to use a root certificate issued by a third-party certificate authority (CA) in order to comply with the financial regulatory requirements and meet relevant standards. + +### **8.5 Maintenance requirements** + +The maintenance requirements for financial DLT are as follows: + +- It is recommended to deploy the system in high-security data centres, and is recommended to support the same-city active-active and remote disaster mechanisms. +- It is recommended to support a distributed operational monitoring platform with both global view and local views to detect anomalies in real time and intervene if necessary. +- It is recommended to carry out the upgrade smoothly and without service interruption whenever possible, and to ensure the trust of financial business and the safety of funds. +- It is recommended to carry out upgrades in a timely manner to avoid causing prolonged disruption to the fund settlement operations. + +### **8.6 Auditability requirements** + +The auditability requirements for financial DLT are as follows: + +- It is recommended to conduct audits before, during and after the financial business activities and establish audit indicators, including investigation of irregularities, internal control system audit and performance audit. +- It is recommended to support auditors to join the DLT network as one of the nodes to conduct real-time audits, or allow auditors, as a third parties outside the IT application network, to access data and evidence in the DLT network on demand or on time. + +- It is recommended to provide tools or methods for exporting full ledger data to traditional data formats, such as relational databases, to support financial audit methods based on traditional database technologies. +- It is recommended that data and evidence relating to audit activities be kept for at least the minimum number of years in compliance with financial industry requirements. Data and evidence include, but are not limited to, records and logs of the activities and operating environment of the parties concerned, records of actions taken by the auditors and information on the audit process and results. + +## **8.7 Interoperability requirements** + +The interoperability requirements for financial DLT are as follows: + +- It is recommended to support a public financial infrastructure that enables DLTs of multiple specific use cases to coexist and collaborate in a seamlessly integrated form through interoperability capabilities, ultimately with the programmable capability to combine transactions and operations of funds and a range of assets, and through smart contracts or APIs to achieve settlement finality and atomic settlement of business-related transactions. +- It is recommended to support the DLT oracle technology to obtain critical off-chain data affecting on-chain financial business, and the oracle service provider should be qualified and authoritative to make the data credible. +- It is recommended to support interaction with off-chain computing systems and off-chain storage systems to improve the computational and storage efficiency of financial DLT systems. +- It is recommended to support the integration of legacy systems and existing infrastructure of the financial industry with a programmable platform via an API that coordinates workflows by sending and receiving messages across systems, and ensures consistency among participants through smart contracts. +- It is recommended to support the transfer of data or assets between different financial DLTs while ensuring the consistency of cross-chain asset transfer, that is, the destination DLT confirms that the received cross-chain assets were the same as agreed in the source DLT to ensure the safety of funds or assets. + +## Appendix I + +## DLT use cases in financial services + +(This appendix does not form an integral part of this Recommendation.) + +### I.1 Trade finance + +#### I.1.1 Overview + +Trade finance refers to structured short-term financing instruments by banks based on assets such as inventories, advances and receivables in commodity transactions. The volume of trade finance markets is huge. With the rapid development of trade settlement instruments and financing methods, financing risks are constantly increasing. This Recommendation uses a typical trade finance scenario, inventory financing, as an example to illustrate the application of distributed ledger technology in trade finance. A trade finance platform based on DLT connects all parties such as trade buyers, trade sellers, credit insurance companies, financial institutions, warehousing companies, logistics companies and regulatory agencies. Data flows such as goods, documents, logistics and regulatory information from the transaction process are stored in DLT, so that real-world goods information and electronic document information can be mutually verified, which helps meet the needs of enterprises to finance physical goods in transportation and warehouse. + +#### I.1.2 Participants + +##### Buyers + +Enterprises and institutions that purchase products or services in international or domestic trade. + +##### Sellers + +Enterprises and institutions that provide products or services in international or domestic trade. + +##### Credit insurance companies + +Credit insurance companies provide comprehensive insurance services such as buyer credit assessment and credit risk guarantee to sellers in trade finance transactions. + +##### Financial institutions + +Financial institutions provide comprehensive financial services such as fund management, financing, settlement in DLT trade finance applications, including: banks, trust companies and insurance companies. + +##### Logistics companies + +Logistics companies provide goods transportation services for both sides of the trade and provide logistics information for all parties involved in the process, including: express delivery companies, logistics companies, shipping companies and air freight forwarders. + +##### Warehousing companies + +Warehousing companies provide warehousing services for goods on both parties of trade and confirm the ownership of goods received, including: distribution centres, storage centres, goods collection centres, goods distribution centres, transfer centres, processing centres, storage and dispatch centres. + +##### Regulators + +Regulators review, supervise and intervene in the use and flow of funds and/or goods in DLT trade finance applications. + +#### I.1.3 Process based on DLT + +The business process of inventory finance is shown in Figure I.1. + +![Diagram of the business process of trade finance based on DLT. A central 'Trade finance platform' is connected to 'Sellers', 'Buyers', 'Credit insurance', 'Regulators', 'Financial institutions', 'Warehousing', and 'Logistics'. Arrows with numbers indicate the flow of information and actions between these entities and the platform.](2b3a967f6ce4f23649be995a353e39f8_img.jpg) + +``` +graph TD; Sellers((Sellers)) -- 1 --> Buyers((Buyers)); Buyers -- 2 --> Sellers; Buyers -- 9 --> Platform[Trade finance platform]; Platform -- 11 --> Warehousing((Warehousing)); Warehousing -- 10 --> Logistics((Logistics)); CreditInsurance((Credit insurance)) -- 5 --> Platform; Regulators((Regulators)) -- 13 --> Platform; Platform -- 3 --> FinancialInstitutions[Financial institutions]; FinancialInstitutions -- 4 --> Platform; Platform -- 6 --> FinancialInstitutions; FinancialInstitutions -- 7 --> Platform; Platform -- 8 --> FinancialInstitutions; FinancialInstitutions -- 12 --> Platform; +``` + +F.751.22(24) + +Diagram of the business process of trade finance based on DLT. A central 'Trade finance platform' is connected to 'Sellers', 'Buyers', 'Credit insurance', 'Regulators', 'Financial institutions', 'Warehousing', and 'Logistics'. Arrows with numbers indicate the flow of information and actions between these entities and the platform. + +**Figure I.1 – Business process of trade finance based on DLT** + +##### 1) Contract signing + +Buyers or sellers sign trade contracts and send them to the trade finance platform. + +This step involves the following roles: DLT user and DLT node operator. + +The following features are used: + +- Ledger management enables trusted storage and management of trade contracts; +- Cryptographic mechanism to protect sensitive information of trade contracts; +- Consensus mechanism to achieve the multiparty witness for trade contracts; +- Node communication implements independent access to financial DLT; +- Key management ensures the security of the creation, exchange, storage, deletion and refreshing of cryptographic keys for accessing confidential information in DLT systems. + +##### 2) Financing application + +Buyers or sellers initiates a financing application on the trade finance platform, provides the financing application, trade contract number and other information, and sets up the financing options. + +This step involves the following roles: DLT user. + +The following features are used: + +- Ledger management enables trusted storage and management of financing application information; +- Consensus mechanism to enable the multiparty witness financing applications; +- Cryptographic mechanism implements sensitive information protection for the financing application information; + +- Smart contract enables intelligent and automated financing application process and business logic; +- Key management ensures the security of the creation, exchange, storage, deletion and refreshing of cryptographic keys for accessing confidential information in DLT systems. + +##### **3) Push application information** + +The trade finance platform pushes the financing application to relevant financial institutions connected to it. + +This step involves the following roles: DLT user, DLT administrator and DLT system developer. + +The following features are used: + +- Cryptographic mechanism implements sensitive information protection for the financing application information; +- Interoperability enables cross-organization broadcasting and cross-system transmission of financing application information; +- Maintenance ensures the forward compatibility of the information and the system in information transmission; +- Concurrency ensures that large volumes of concurrent transactions are quickly and correctly responded to. + +##### **4) Information retrieval application** + +Financial institutions initiate an information request on the trade finance platform. + +This step involves the following roles: DLT user and DLT system operator. + +The following features are used: + +- Cryptographic mechanism to protect sensitive information in credit data of both parties; +- Trusted hardware enables further secure sensitive data and critical business logic; +- Interoperability enables the transmission of mutual credit information between DLT and banking systems; +- Key management ensures the security of the creation, exchange, storage, deletion and refreshing of cryptographic keys for accessing confidential information in DLT systems; +- Privacy protection implements the protection of sensitive transaction data during information transmission. + +##### **5) Push insurance policies** + +The trade finance platform pushes insurance policies in response to the request from financial institutions. + +This step involves the following roles: DLT user, DLT administrator, DLT system developer and DLT system operator. + +The following features are used: + +- Cryptographic mechanism to protect mutual credit data and sensitive information in trade contracts; +- Interoperability enables cross-system transmission of insurance policies; +- Maintenance ensures the forward compatibility of the information and the system in information transmission; +- Key management ensures the security of the creation, exchange, storage, deletion and refreshing of cryptographic keys for accessing confidential information in DLT systems. + +##### **6) Obtain the amount and voucher** + +The trade finance platform pushes the trade amount and transaction voucher information according to the application of the financial institution. + +This step involves the following roles: DLT user, DLT administrator, DLT system developer and DLT system operator. + +The following features are used: + +- Cryptographic mechanism to protect sensitive information in trade contracts and transaction details; +- Trusted hardware enables further secure sensitive data and critical business logic; +- Interoperability enables the transmission of trade contracts and transaction details between DLT and banking systems; +- Maintenance ensures forward compatibility of information and systems in information transmission. + +##### **7) Bank verification** + +Financial institutions verify policy information, transaction information and other application information pushed by the trade finance platform. + +This step involves the following roles: DLT user. + +The following features are used: + +- Cryptographic mechanism enables the protection of sensitive information in mutual trade information, trade contracts, transaction details and insurance policy information; +- Trusted hardware enables further secure sensitive data and critical business logic; +- Key management ensures the security of the creation, exchange, storage, deletion and refreshing of cryptographic keys for accessing confidential information in DLT systems; +- Privacy protection implements the protection of sensitive transaction data during information transmission. + +##### **8) Bank examination and approval** + +Financial institutions shall check the business background, determine the financing currency, financing ration, financing amount, financing term, financing fee, financing interest rate and margin ratio, and push the financing approval results to the trade finance platform. + +This step involves the following roles: DLT user, DLT system developer and DLT system operator. + +The following features are used: + +- Cryptographic mechanism enables the protection of sensitive information in mutual trading information, trade contracts, transaction details, insurance policy information and financing information; +- Trusted hardware enables further secure sensitive data and critical business logic; +- Interoperability enables information interaction between DLT and banking systems; +- Maintenance ensures the forward compatibility of the information and the system in information transmission; +- Key management ensures the security of the creation, exchange, storage, deletion and refreshing of cryptographic keys for accessing confidential information in DLT systems; +- Privacy protection implements the protection of sensitive transaction data during information transmission. + +##### **9) Contract trigger** + +The trade finance platform selects the optimal financing approval result based on the financing plan preset by the financing applicant, triggers the smart contract, automatically generates the financing contract, triggers the fund allocation and closes the approval result that does not meet the financing plan. + +This step involves the following roles: DLT administrator and DLT application developer. + +The following features are used: + +- Consensus mechanism to ensure that financing actions are witnessed by multiple parties to prevent the risk of repeated financing; +- Smart contract enables intelligent and automatic execution of financing plans; +- Concurrency ensures that large volumes of concurrent transactions are quickly and correctly responded to; +- Governance ensures best practices in the management of DLT nodes, consensus algorithms and financial smart contracts. + +##### **10) Transportation of goods** + +Logistics institutions provide goods transportation services to buyers or sellers, and push the type, quantity, ownership and logistics service provider of the goods to the trade finance platform. + +This step involves the following roles: DLT user and DLT node operator. + +The following features are used: + +- Ledger management enables the reliable storage and management of logistics information; +- The consensus mechanism enables the mutual verification of logistics and warehousing to ensure the integration of logistics and information flow; +- Node communication implements independent access to financial DLTs; +- Key management ensures the security of the creation, exchange, storage, deletion and refreshing of cryptographic keys for accessing confidential information in DLT systems. + +##### **11) Warehousing of goods** + +Warehousing institutions provide goods warehousing services to buyers, sellers, or logistics institutions and push the type, quantity, ownership and warehousing service provider of goods to the trade finance platform. + +This step involves the following roles: DLT user and DLT node operator. + +The following features are used: + +- Ledger management enables trusted storage and management of warehouse information; +- Consensus mechanism enables mutual verification of logistics and warehousing to ensure the integration of logistics and information flows; +- Node communication implements independent access to financial DLTs; +- Key management ensures the security of the creation, exchange, storage, deletion and refreshing of cryptographic keys for accessing confidential information in DLT systems. + +##### **12) Post-loan management** + +Financial institutions verify contracts, financing applications, logistics and warehousing stored in financial distributed ledger to ensure the authenticity of trade behaviour and the matching of financing amounts and goods values to eliminate loan misappropriation and fake trade risks. + +This step involves the following roles: DLT auditor, DLT system developer, DLT system operator and DLT node operator. + +The following features are used: + +- Ledger management enables the reliable storage and management of logistics information, trade information and financing information; +- Consensus mechanism to ensure the authenticity and credibility of logistics, information flow and capital flow; +- Cryptographic mechanism to protect sensitive data in personal information and fund information; +- Trusted hardware enables further secure sensitive data and critical business logic; +- Interoperability enables information interaction between DLT and banking systems; +- Maintenance ensures the forward compatibility of the information and the system in information transmission; +- Key management ensures the security of the creation, exchange, storage, deletion and refreshing of cryptographic keys for accessing confidential information in DLT systems; +- Privacy protection implements the protection of sensitive transaction data during information transmission. + +##### **13) Regulatory compliance** + +Regulators invoke the financial distributed ledger of trade contracts, logistics, warehousing and financing records to confirm that financial institutions' financing services comply with regulations. The implementation of regulatory compliance steps is recommended to be determined based on specific business needs and regulatory requirements. + +This step involves the following roles: DLT regulator, DLT system developer, DLT system operator and DLT node operator. + +The following features are used: + +- Ledger management enables the reliable storage and management of logistics information, trade information and financing information; +- Consensus mechanism to ensure the authenticity and credibility of logistics, information flow and capital flow; +- Cryptographic mechanism to protect sensitive data in personal information and fund information; +- Trusted hardware enables further secure sensitive data and critical business logic; +- Interoperability enables the interaction of information between DLT and regulatory systems; +- Maintenance ensures the forward compatibility of the information and the system in information transmission; +- Key management ensures the security of the creation, exchange, storage, deletion and refreshing of cryptographic keys for accessing confidential information in DLT systems; +- Privacy protection implements the protection of sensitive transaction data during information transmission; +- Governance ensures best practices in the management of DLT nodes, consensus algorithms and financial smart contracts. + +### **I.2 Supply chain finance** + +#### **I.2.1 Overview** + +To help small and medium-sized enterprises (SMEs) suppliers revitalize their accounts receivable, solve financing problems and reduce the risks of commercial banking, traditional supply chains are enabled by means of financial DLT. The accounts receivable platform built based on DLT uses standardized digital asset voucher (DAV) to realize the issuing, circulating, financing, detachable, reimbursable, traceable and other businesses of the core enterprise credit accounts receivable vouchers in the supply chain. Supported by the platform, the multistream integration of voucher flow, cash flow and order flow is achieved under the premise of ensuring data security and data privacy. There is also distributed storage of core data to provide information support services for the transfer and discounting of DAV between enterprises and financial institutions. + +#### **I.2.2 Participants** + +##### **Supply chain enterprise** + +All participating enterprises are involved in the production to distribution process. + +##### **Core enterprise** + +Enterprises that are in the middle link of the supply chain, with large scale and strong presence in the supply chain, have the right to speak in the whole supply chain and have a huge impact on the logistics and cash flow of the entire supply chain. + +##### **Funder** + +A financial service institution or bank that provides funds and credit. + +##### **Financial institution** + +An organization that provides fund management services. + +##### **Regulator** + +Monitor and audit the flow of funds in the supply chain finance platform. + +##### **Platform development operation and maintenance party** + +Provide DLT platform development and operation and maintenance management services. + +#### **I.2.3 Process based on DLT** + +The business process of supply chain finance is shown in Figure I.2. + +![Figure I.2 – Business process of supply chain finance based on DLT. The diagram illustrates the flow of information and value between various entities. At the top, 'Supply chain enterprise A' and 'Supply chain enterprise N' are shown. Below them is a 'Core enterprise'. At the bottom is a 'Supply chain finance platform' containing 'Financial trusted hardware' represented by four connected hexagons. To the right is a 'Funder'. External entities on the far right include 'Financial institutions', a 'Regulator', and a 'Platform development operation and maintenance party'. Arrows with circled numbers indicate the following interactions: (1) Registration from enterprises to the platform; (2) Information filing from the Funder to the platform; (3) Registration from the Core enterprise to the platform; (4) Data exchange between enterprises and the Funder; (5) Data exchange between enterprises and the platform; (6) Flow from enterprise A to enterprise N; (7) Data exchange between enterprise N and the Funder; (8) Data exchange between enterprise N and the platform; (9) Data exchange between enterprise N and the Funder; (10) Flow from the Core enterprise to the Funder; (11) Interaction between Financial institutions and the Funder; (12) Interaction between the Regulator and the Funder; (13) Interaction between the platform and the Funder; (14) Interaction between the Platform development party and the Funder.](7133ccf78043568ca62ecbcd43628a4a_img.jpg) + +Figure I.2 – Business process of supply chain finance based on DLT. The diagram illustrates the flow of information and value between various entities. At the top, 'Supply chain enterprise A' and 'Supply chain enterprise N' are shown. Below them is a 'Core enterprise'. At the bottom is a 'Supply chain finance platform' containing 'Financial trusted hardware' represented by four connected hexagons. To the right is a 'Funder'. External entities on the far right include 'Financial institutions', a 'Regulator', and a 'Platform development operation and maintenance party'. Arrows with circled numbers indicate the following interactions: (1) Registration from enterprises to the platform; (2) Information filing from the Funder to the platform; (3) Registration from the Core enterprise to the platform; (4) Data exchange between enterprises and the Funder; (5) Data exchange between enterprises and the platform; (6) Flow from enterprise A to enterprise N; (7) Data exchange between enterprise N and the Funder; (8) Data exchange between enterprise N and the platform; (9) Data exchange between enterprise N and the Funder; (10) Flow from the Core enterprise to the Funder; (11) Interaction between Financial institutions and the Funder; (12) Interaction between the Regulator and the Funder; (13) Interaction between the platform and the Funder; (14) Interaction between the Platform development party and the Funder. + +F.751.22(24) + +**Figure I.2 – Business process of supply chain finance based on DLT** + +1) Registration and certification. Supply chain enterprises register on the platform, improve their real-name authentication information, upload their enterprise qualification, and their information will be recorded on the blockchain, creating a record on the enterprise chain. + +This step involves the following role: DLT user. + +The following features are used: + +- Consensus mechanism to achieve consensus storage of information on the chain; +- Privacy protection capabilities to enable encrypted storage of the users' private data; +- Key management capabilities to distribute and manage secret keys for users. + +2) Information filing. When a supplier initiates a financing application on a supply chain finance platform for the first time, the funders will archive the application for the supplier. The archival information includes the industrial and commercial information of enterprises, the business information of the enterprise credit grant subjects, etc. After approval by the funder, the processing results will be updated to the supply chain finance platform. + +This step involves the following role: DLT user. + +The following features are used: + +- Consensus mechanism to achieve consensus storage of information on the chain; +- Authority capabilities by fund administrators to manage supplier users. + +3) Issue a DAV. Supply chain enterprises apply for the issuance of accounts receivable notes within the scope of their credit lines, and the application information is stored on the blockchain. + +This step involves the following role: DLT user. + +The following features are used: + +- Consensus mechanism to achieve consensus storage of information on the chain; +- Privacy protection capabilities to enable encrypted storage of user transaction information; +- Concurrency capabilities to ensure the orderly execution of platform transactions in the case of high transaction volume. + +4) Financing application. The archived successful enterprise will receive the financing rates and other information provided by the funders. After confirmation, the enterprise submits a financing application. The supply chain finance platform pushes the enterprise's industrial and commercial + +information, financing amounts, financing rates, payment information, trade authenticity materials and DAV to investors through blockchain. + +This step involves the following role: DLT user. + +The following features are used: + +- Privacy protection capabilities to provide privacy protection for sensitive transaction information of users. + +5) Financing application approval. After receiving a financing application pushed by a supply chain finance platform, the funders shall check and approve it, and if approved, the loan will be made, otherwise the application will be rejected. After the loan is successful, the loan information and the loan order attachment are recorded on the blockchain. + +This step involves the following role: DLT user. + +The following features are used: + +- Consensus mechanism to achieve consensus storage of loan information; +- Privacy protection capabilities to provide privacy protection for sensitive transaction information of users. + +6) DAV transfer. When the DAV is transferred, the enterprises on both sides of the transaction confirm the transfer intention through the supply chain finance platform, sign the electronic contract and keep the certificate of the contract. + +This step involves the following role: DLT user. + +The following features are used: + +- Consensus mechanism to achieve consensus storage of electronic contract information; +- Cryptographic mechanism to ensure the authenticity and privacy of electronic contracts. + +7) Fund payment. The funder makes payment to the bearer through the supply chain finance platform trading fund supervision module, and the fund is in the circulation state and cannot be withdrawn. + +This step involves the following role: DLT user. + +The following features are used: + +- Consensus mechanism to achieve consensus storage of payment information; +- Privacy protection capabilities to provide privacy protection for sensitive transaction information of users. + +8) DAV sending. After seeing the payment of funds, the holder endorses the DAV in the e-bank and sends it to the financial institution's account tied to the funder's system and informs the funder to sign for the DAV through the supply chain finance platform. + +This step involves the following role: DLT user. + +The following features are used: + +- Consensus mechanism to achieve consensus storage of DAV flow information; +- Privacy protection capabilities to provide privacy protection for sensitive transaction information of users. + +9) DAV acceptance. The funders receive the DAV at the e-bank, confirm the endorsement on the supply chain finance platform and apply for unfreezing the fund. The DAV witness module of the supply chain finance platform queries the DAV flow status and unfreezes funds after approval. + +This step involves the following role: DLT administrators. + +The following features are used: + +- Consensus mechanism to achieve consensus storage of DAV circulation status; +- Privacy protection capabilities to provide privacy protection for sensitive transaction information of users. + +10) Repayment at maturity. The supply chain finance platform will send the final payment details to the funder on the due payment date (the next business day after the committed payment date). This step involves the following role: DLT user. + +The following features are used: + +- Consensus mechanism to achieve consensus storage of repayment information; +- Privacy protection capabilities to provide privacy protection for sensitive transaction information of users. + +11) Separate accounting and settlement. The financial institution shall carry out the settlement operation in real-time and transfer the settlement to the collection account designated by the funders. The funder shall automatically deduct the funds from the designated repayment account or repayments on the due date of the financing. + +This step involves the following role: DLT auditor. + +The following features are used: + +- Consensus mechanism to achieve consensus storage of operation records and fund flow information; +- Auditability capabilities to audit the business of the platform. + +12) Regulatory compliance. Regulators conduct supervision and audit on the flow of funds and business operations of the supply chain finance platforms through the supervision module of the supply chain finance platforms and the function of querying information on the chain. The implementation of regulatory compliance steps is recommended to be determined based on specific business needs and regulatory requirements. + +This step involves the following role: DLT regulator. + +The following features are used: + +- Auditability capabilities to audit the data queries on the platform; +- Governance and compliance in protocol functions to monitor and manage the platform business; +- Governance capabilities to govern the platform and ensure its compliance; +- Interoperability capabilities to enable regulators to access transaction data across supply chain finance platforms and to examine and monitor the data. + +13) Financial trust hardware. All-platform services are built using financial security and trusted hardware to protect the privacy of sensitive transactions and data. + +- Financial trusted hardware in resource functions to ensure efficient and secure operation of the platform. + +14) Development and maintenance. The platform development operation and maintenance party develops the supply chain finance platform to implement the corresponding functions, and periodically inspects and maintains the supply chain finance platform. + +This step involves the following roles: DLT system operator, DLT node operator and DLT application operator. + +The following features are used: + +- Node communication capabilities to manage node entry and exit; + +- Ledger management capabilities to manage data; +- Smart contract capabilities to manage and apply smart contracts; +- Stability capabilities to improve the platform's ability to effectively handle failures, reduce the risk and loss associated with the platform's handling of failures and improve the platform's fault tolerance; +- Maintenance capabilities to enable real-time monitoring of platform operating resources, node resource status and other service resources, improving the efficiency of platform fault location and enabling efficient maintenance of the platform. + +## Bibliography + +- [b-ITU-T F.751.0] Recommendation ITU-T F.751.0 (2020), *Requirements for distributed ledger systems*. +- [b-ITU-T F.751.1] Recommendation ITU-T F.751.1 (2020), *Assessment criteria for distributed ledger technology (DLT) platforms*. +- [b-ITU-T F.751.2] Recommendation ITU-T F.751.2 (2020), *Reference framework for distributed ledger technologies*. +- [b-ITU-T F.751.6] Recommendation ITU-T F.751.6 (2022), *Performance assessment methods for distributed ledger technology platforms*. +- [b-ITU-T F.751.7] Recommendation ITU-T F.751.7 (2022), *Functional assessment methods for distributed ledger technology platforms*. +- [b-ITU-T X.800] Recommendation ITU-T X.800 (1991), *Security architecture for open systems interconnection for CCITT applications*. +- [b-ITU-T X.1400] Recommendation ITU-T X.1400 (2020), *Terms and definitions for distributed ledger technology*. +- [b-ITU-T Y.2091] Recommendation ITU-T Y.2091 (2011), *Terms and definitions for next generation networks*. +- [b-ISO 22739] ISO 22739:2020, *Blockchain and distributed ledger technologies—Vocabulary*. +- [b-ISO 23257] ISO 23257:2022, *Blockchain and distributed ledger technologies—Reference architecture*. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| 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b/marked/F/T-REC-F.751.6-202212-I_PDF-E/raw.md @@ -0,0 +1,441 @@ + + +# Recommendation **ITU-T F.751.6 (12/2022)** + +SERIES F: Non-telephone telecommunication services +Multimedia services + +# --- **Performance assessment methods for distributed ledger technology platforms** + +![ITU logo](390120de4fe440c42fea8154fcaad334_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multdestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| MULTIMEDIA SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.751.6 + +# Performance assessment methods for distributed ledger technology platforms + +## Summary + +Recommendation ITU-T F.751.6 is an extension to Recommendation ITU-T F.751.1, and focuses on distributed ledger technology (DLT) performance assessment methods. Based on the performance assessment criteria defined in Recommendation ITU-T F.751.1, this Recommendation defines specific performance metrics and relevant workflow for the quantitative performance assessment for the DLT platform. This Recommendation can be used as a guideline of DLT platform performance assessment for developers, users, third party testers and researchers. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.751.6 | 2022-12-14 | 16 | 11.1002/1000/15200 | + +## Keywords + +Distributed ledger technology, DLT, performance assessment. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2023 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +###### Page + +| | | | +|-----|----------------------------------------------|---| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| 3.1 | Terms defined elsewhere ..... | 1 | +| 3.2 | Terms defined in this Recommendation..... | 2 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | Conventions ..... | 2 | +| 6 | Metric definitions ..... | 2 | +| 6.1 | Transaction delay (TD)..... | 2 | +| 6.2 | Average transaction delay (ATD) ..... | 2 | +| 6.3 | Maximum transaction delay (MTD)..... | 3 | +| 6.4 | Received transaction per second (RTPS) ..... | 3 | +| 6.5 | Confirmed transaction per second (CTPS)..... | 3 | +| 6.6 | Queries per second (QPS) ..... | 3 | +| 6.7 | Transaction success rate (TSR) ..... | 4 | +| 7 | Performance testing workflow..... | 4 | +| 7.1 | Test case design..... | 4 | +| 7.2 | Environment preparation ..... | 5 | +| 7.3 | Test execution..... | 6 | +| 7.4 | Report generation ..... | 6 | +| 7.5 | Result review ..... | 7 | +| | Bibliography..... | 8 | + + + +# Recommendation ITU-T F.751.6 + +## Performance assessment methods for distributed ledger technology platforms + +# 1 Scope + +This Recommendation provides performance assessment methods for distributed ledger technology (DLT). It defines specific performance metrics and relevant workflow for the quantitative performance assessment for the DLT platform. This Recommendation can be used as a guideline of DLT platform performance assessment for developers, users, third party testers and researchers. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T F.751.1] Recommendation ITU-T F.751.1 (2020), *Assessment criteria for distributed ledger technology platforms*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 account** [ITU-T F.751.1]: Representation of an entity whose data is recorded on a distributed ledger. + +**3.1.2 consensus** [b-ITU-T F.751.0]: Agreement that a set of transactions is valid. + +**3.1.3 digital signature** [b-ITU-T X.800]: Data appended to, or a cryptographic transformation of a data unit that allows a recipient of the data unit to prove the source and integrity of the data unit and protect against forgery, e.g., by the recipient. + +**3.1.4 distributed ledger** [b-ITU-T F.751.0]: A type of ledger that is shared, replicated, and synchronized in a distributed and decentralized manner. + +**3.1.5 distributed ledger technology (DLT)** [ITU-T F.751.1]: Technology enabling large groups of nodes in distributed ledger networks to reach agreement and record information without the need for a central authority. + +**3.1.6 node** [b-ITU-T F.751.0]: Device or process that participates in a distributed ledger network. + +**3.1.7 smart contract** [b-ITU-T F.751.0]: Program written on the distributed ledger system that encodes the rules for specific types of distributed ledger system transactions in a way that can be validated, and triggered by specific conditions. + +**3.1.8 transaction** [b-ITU-T F.751.0]: An incident or an operation that leads to a change in the status of a ledger, such as adding a record or equivalent exchange based on currency, etc. + +**3.1.9 unspent transaction output (UTXO) model** [b-ITU-T F.751.2]: Model where transaction spends output from prior unspent transactions and generates new outputs that can be spent in the future. The unspent transactions are kept in each node. + +## 3.2 Terms defined in this Recommendation + +None. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|----------------------------------| +| ATD | Average Transaction Delay | +| CPU | Central Processing Unit | +| CTPS | Confirmed Transaction Per Second | +| DLT | Distributed Ledger Technology | +| I/O | Input/Output | +| MTD | Maximum Transaction Delay | +| QPS | Queries Per Second | +| RTPS | Received Transaction Per Second | +| TD | Transaction Delay | +| TSR | Transaction Success Rate | +| UTXO | Unspent Transaction Output | + +# 5 Conventions + +The following conventions are used in this Recommendation: + +- The keywords "**is required to**" indicate a requirement which must be strictly followed and from which no deviation is permitted, if conformance to this Recommendation is to be claimed; +- The keywords "**is recommended**" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance; +- The keywords "**is not recommended**" indicate a requirement which is not recommended but which is not specifically prohibited. Thus, conformance with this Recommendation can still be claimed even if this requirement is present. + +# 6 Metric definitions + +## 6.1 Transaction delay (TD) + +Transaction delay (TD) is the time duration between sending (by the client) a transaction and receiving (by the DLT platform) its response. The TD reflects the speed of responding to the user's requests of a DLT platform. + +The value of TD is defined as follows: + +$$TD = t_{recv} - t_{send} \quad (6-1)$$ + +where $t_{recv}$ is the time of receiving the response, $t_{send}$ is the time of sending a transaction. + +## 6.2 Average transaction delay (ATD) + +Average transaction delay (ATD) is the average TD for a group of transactions. The ATD reflects the overall delay for transaction processing of a DLT platform. + +The value of ATD is defined as follows: + +$$ATD = \text{avg}(TD_1, TD_2, \dots, TD_n) \quad (6-2)$$ + +where $TD_1, TD_2, \dots, TD_n$ is a set of transaction delays. + +## 6.3 Maximum transaction delay (MTD) + +Maximum transaction delay (MTD) is the maximum TD for a group of transactions. The MTD reflects the worst delay for transaction processing of a DLT platform. + +The value of MTD is defined as follows: + +$$MTD = \text{max}(TD_1, TD_2, \dots, TD_n) \quad (6-3)$$ + +where $TD_1, TD_2, \dots, TD_n$ is a set of transaction delays. + +## 6.4 Received transaction per second (RTPS) + +Received transaction per second (RTPS) is the number of transactions received by the DLT platform per second. RTPS reflects the efficiency to handle requests of a DLT platform. + +The value of RTPS is defined as follows: + +$$RTPS = \frac{n_{\text{recv}}}{t_{\text{recv}}} \quad (6-4)$$ + +where $n_{\text{recv}}$ is the number of transactions received by the DLT platform, and $t_{\text{recv}}$ is the time duration between sending (by the client) and receiving (by the DLT platform) of those $n_{\text{recv}}$ transactions. + +## 6.5 Confirmed transaction per second (CTPS) + +Confirmed transaction per second (CTPS) is the number of transactions confirmed by the DLT platform per second. The confirmed transactions are required to reach a consensus after received, and finally stored in the distributed ledger. The CTPS reflects the ability to execute transactions and to store them in the distributed ledger of a DLT platform. The transaction execution processes are required to contain the whole lifecycle of the transaction, including transaction format verification, digital signature verification, contract execution, message delivery, reaching a consensus and other processes designed by the DLT platform. + +The value of CTPS is defined as follows: + +$$CTPS = \frac{n_{\text{conf}}}{t_{\text{conf}}} \quad (6-5)$$ + +where $n_{\text{conf}}$ is the number of confirmed transactions stored in the ledger, and $t_{\text{conf}}$ is the time duration between sending (by the client) the first transaction and confirming (by the DLT platform) the last transaction. + +## 6.6 Queries per second (QPS) + +Queries per second (QPS) is the number of query results received from the DLT platform. QPS reflects the querying ability to query of a DLT platform. Before the query performance testing, it is required to do something to avoid getting the results from the cache every time, such as closing the cache service, or cleaning the cache data, or querying in a big range to avoid the cache hitting. + +The value of QPS is defined as follows: + +$$QPS = \frac{n_q}{t_q} \quad (6-6)$$ + +where $n_q$ is the number of query results and $t_q$ is the time duration between sending the first query request and receiving the last query result by the client. + +## 6.7 Transaction success rate (TSR) + +Transaction success rate (TSR) is the rate of the transactions that can be processed successfully and stored in the ledger after they have been received by the DLT platform. The TSR reflects the robustness of a DLT platform in high-pressure scenarios. + +The value of TSR is defined as follows: + +$$TSR = \frac{n_{conf}}{n_{send}} \times 100\% \quad (6-7)$$ + +where $n_{conf}$ is the number of confirmed transactions in the ledger and $n_{send}$ is the number of sent transactions by the client. + +# 7 Performance testing workflow + +The DLT platform performance testing workflow consists of the five steps shown in Figure 1. + +![Flowchart of the performance testing workflow with five steps: Step 1: Test case design, Step 2: Environment preparation, Step 3: Test execution, Step 4: Report generation, and Step 5: Result review. The steps are connected sequentially from left to right.](c2fc2621e8206d24427b56bcb2398fc0_img.jpg) + +``` +graph LR; S1[Step 1 +Test case +design] --> S2[Step 2 +Environment +preparation]; S2 --> S3[Step 3 +Test +execution]; S3 --> S4[Step 4 +Report +generation]; S4 --> S5[Step 5 +Result +review]; +``` + +F.751.6(22) + +Flowchart of the performance testing workflow with five steps: Step 1: Test case design, Step 2: Environment preparation, Step 3: Test execution, Step 4: Report generation, and Step 5: Result review. The steps are connected sequentially from left to right. + +**Figure 1 – Performance testing workflow** + +Step 1: Test case design. Before designing the test case, it is required that information about the DLT platform be collected. Then, the test purpose, workflows and expected results are to be defined in accordance with the test requirements; + +Step 2: Environment preparation, including hardware environment and software environment. Before test execution, it is required to prepare the hardware and build a software environment; + +Step 3: Test execution. It is required that the test be executed following the workflow defined in the test case design step; + +Step 4: Report generation is required after the test execution. The report is required to record the results and description of the test environment, such as the calculation results of the performance testing result, hardware specifications, software parameters, tester information, test time, test place, and so on; + +Step 5: Result review is required before the report takes effect. It is required that the test results be reviewed by other experts to ensure fairness and correctness. + +## 7.1 Test case design + +### 7.1.1 Test scenario + +The test scenario means different situations used for testing. To simulate the situations similar to the production environment, it is required to combine multiple influencing factors. The key factors include: + +- a) The number of clients that send transactions simultaneously, to simulate users sending transactions to the DLT platform; +- b) The number of transactions received by the DLT platform per second, to simulate the pressure on the DLT platform; and +- c) The time during which transactions are continuously sent. + +### **7.1.2 Transaction size** + +The transaction size is the total number of bytes of data in the transaction body. Usually, there is other information contained in the transaction body, additional to the account and amount information. The larger the data contained in the transaction, the slower the transaction is processed. It is required to design test cases considering the size of the transaction body. + +### **7.1.3 Transaction logic** + +The transaction logic is usually designed in the smart contract determined by the application business. The test cases are required to cover different logics with different complexities, such as: + +- a) Transfers between two accounts, for example transfer from account A to account B; +- b) Transfers between many accounts, for example make random transfers between multiple accounts; and +- c) Transactions with complexity business, for example transactions with verification and judgement. + +### **7.1.4 Scale of the ledger** + +The scale of the ledger is determined by the number of transactions stored in the ledger, and commonly the ledger grows continuously in the DLT platform. The number of transactions in the ledger will sometimes have an impact on performance, such as analysis of the relationship between the transactions, especially for unspent transaction output (UTXO) model-based DLT platforms. The test cases are required to be designed with a certain gradient of the scale of the ledger. Two factors are required to be considered, including: + +- a) The number of transactions stored in the ledger, for example set as 1 million, 100 million, 1 billion; +- b) The disk space storage by the ledger, for example set as 10 GB, 100 GB, 1 TB. + +### **7.1.5 Scale of the DLT network** + +The scale of the DLT network is determined by the number of nodes running in the network, which will have an impact on consensus efficiency. The number of nodes can be set as 4 nodes, 16 nodes, 32 nodes, etc. Less than 3 nodes is not recommended. + +It is recommended that the test case be reviewed by other experts, to ensure that it is reasonable and comprehensive. + +## **7.2 Environment preparation** + +### **7.2.1 Server** + +The server is the equipment running software, the basic environment of performance assessment for the DLT platform. Stability and high performance of the server is required. The key specifications of the server are required to be recorded before testing, including: + +- a) Type of disk; +- b) Storage capacity; +- c) Input/output (I/O) speed; +- d) Main frequency of the central processing unit (CPU); +- e) Number of the CPU cores; +- f) Memory capacity; +- g) Number of servers. + +The specifications are also recommended to be recorded, including: + +- a) Ambient temperature; +- b) Ambient humidity; +- c) Brand of the servers; +- d) Manufacture date of the servers. + +### **7.2.2 Network** + +The network is the communication infrastructure for the various nodes. Network quality determines the speed and stability of transaction transmission. Different types of networks are required to be considered, such as twisted pair network, optical network, local area network, wide area network and so on. + +### **7.2.3 DLT platform** + +The DLT platform is the object to be assessed. An explicit version of the DLT platform is required to be provided because different versions imply different functions for the software. + +### **7.2.4 Performance testing tool** + +The performance testing tool is used for sending transactions to the DLT platform with high pressure and calculating the final values of the performance of the DLT platform. The maximum throughput of the testing tool is required to be higher than the DLT platform under test. + +## **7.3 Test execution** + +The following conditions are required during test execution: + +- a) The steps designed in the test cases are to be followed; +- b) Each test case is to be executed multiple times, and the average value is to be taken as the final result; +- c) It should be ensured that the testing environment of each test is consistent, including hardware specifications, software parameters and execution time; +- d) Key logs are to be recorded during the execution, including the logs of the DLT platform and the testing tool. + +## **7.4 Report generation** + +After test execution, the testing report is required to be generated based on testing results. The report is recommended to be generated by the performance testing tool automatically. The contents are required to be recorded in the report, including: + +- a) Testing environment, including: + - i) Hardware specifications; + - ii) Software parameters; + - iii) Software version; + - iv) Network bandwidth; + - v) CPU usage; + - vi) Memory usage; + - vii) Disk usage; +- b) The tested value of the matrices defined in clause 6; +- c) When and where the test was executed; +- d) Information of the testers, such as name, number and so on. + +It is required that, once generated, the report is reviewed by other experts to ensure the correctness of the final results. + +## **7.5 Result review** + +The test results are recommended to be reviewed as follows: + +- a) The testing report is generated completely; +- b) The number of experts is an odd number bigger than 3; +- c) For approval, at least half of the experts need to agree to the test results. + +# Bibliography + +- [b-ITU-T F.751.0] Recommendation ITU-T F.751.0 (2020), *Requirements for distributed ledger system.* +- [b-ITU-T F.751.2] Recommendation ITU-T F.751.2 (2020), *Reference framework for distributed ledger technologies.* +- [b-ITU-T X.800] Recommendation ITU-T X.800 (1991), *Security architecture for Open Systems Interconnection for CCITT applications.* + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.751.7-202212-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg b/marked/F/T-REC-F.751.7-202212-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..ac295b1b0c7f14b1c5a33ef6682b1b017c812477 --- /dev/null +++ b/marked/F/T-REC-F.751.7-202212-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:37aed4fc114a39843438175326e0b7e1d09a9d6075723d82fea32040fd560ee4 +size 7192 diff --git a/marked/F/T-REC-F.751.7-202212-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg b/marked/F/T-REC-F.751.7-202212-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d0e492c45c243a77a562524d5ba84b46ec13410a --- /dev/null +++ b/marked/F/T-REC-F.751.7-202212-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:cfef12750d99291bfba16661f0a82ccd179fd0094b4d0bcaf6b6fd563c7cd8fe +size 132316 diff --git a/marked/F/T-REC-F.751.7-202212-I_PDF-E/raw.md b/marked/F/T-REC-F.751.7-202212-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..672745ea572a3a4009da71286f554fbb51d317a3 --- /dev/null +++ b/marked/F/T-REC-F.751.7-202212-I_PDF-E/raw.md @@ -0,0 +1,769 @@ + + +# Recommendation **ITU-T F.751.7 (12/2022)** + +SERIES F: Non-telephone telecommunication services +Multimedia services + +--- + +## **Functional assessment methods for distributed ledger technology platforms** + +![ITU logo](390120de4fe440c42fea8154fcaad334_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +### **TELEGRAPH SERVICE** + +| | | +|-----------------------------------------------------------------|-------------| +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | + +### **MOBILE SERVICE** + +| | | +|--------------------------------------------------------|-------------| +| Mobile services and multdestination satellite services | F.110–F.159 | +|--------------------------------------------------------|-------------| + +### **TELEMATIC SERVICES** + +| | | +|-------------------------------------------|-------------| +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | + +### **MESSAGE HANDLING SERVICES** + +| | | +|--|-------------| +| | F.400–F.499 | +|--|-------------| + +### **DIRECTORY SERVICES** + +| | | +|--|-------------| +| | F.500–F.549 | +|--|-------------| + +### **DOCUMENT COMMUNICATION** + +| | | +|--------------------------------------|-------------| +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | + +### **DATA TRANSMISSION SERVICES** + +| | | +|--|-------------| +| | F.600–F.699 | +|--|-------------| + +### **MULTIMEDIA SERVICES** + +| | | +|--|--------------------| +| | F.700–F.799 | +|--|--------------------| + +### **ISDN SERVICES** + +| | | +|--|-------------| +| | F.800–F.849 | +|--|-------------| + +### **UNIVERSAL PERSONAL TELECOMMUNICATION** + +| | | +|--|-------------| +| | F.850–F.899 | +|--|-------------| + +## **ACCESSIBILITY AND HUMAN FACTORS** + +| | | +|--|-------------| +| | F.900–F.999 | +|--|-------------| + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.751.7 + +# Functional assessment methods for distributed ledger technology platforms + +## Summary + +Recommendation ITU-T F.751.7 defines functional assessment methods for distributed ledger technology (DLT) platforms based on the assessment criteria defined in Recommendation ITU-T F.751.1. For each item of the assessment criteria defined in Recommendation ITU-T F.751.1, one test case is defined in this Recommendation accordingly. The description of each test case is composed of test purpose, test workflows and expected results. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.751.7 | 2022-12-14 | 16 | 11.1002/1000/15201 | + +## Keywords + +Distributed ledger technology, DLT, functional assessment. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2023 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Overview of assessment methods..... | 2 | +| 7 Core technology assessment methods ..... | 3 | +| 7.1 Account creation..... | 3 | +| 7.2 Transaction processing ..... | 4 | +| 7.3 Query ..... | 4 | +| 7.4 Consensus algorithm effectiveness..... | 5 | +| 7.5 Private key management..... | 6 | +| 7.6 Smart contract mechanism ..... | 7 | +| 7.7 Security of cryptography ..... | 8 | +| 7.8 Decentralization..... | 9 | +| 8 Application support assessment methods ..... | 10 | +| 8.1 User authentication ..... | 10 | +| 8.2 System stability ..... | 10 | +| 8.3 Economic mechanism design ..... | 10 | +| 8.4 Information privacy ..... | 11 | +| 8.5 Application support functions ..... | 12 | +| 8.6 Transaction origin..... | 13 | +| 9 Operation assessment methods ..... | 13 | +| 9.1 Network management..... | 13 | +| 9.2 Risk management and mitigation ..... | 13 | +| 9.3 Data storage sustainability..... | 14 | +| 10 Ecosystem assessment methods..... | 14 | +| 10.1 Platform maturity..... | 14 | +| 10.2 Open source ..... | 14 | +| 10.3 Maintenance ..... | 15 | + + + +# Recommendation ITU-T F.751.7 + +## Functional assessment methods for distributed ledger technology platforms + +## 1 Scope + +This Recommendation defines distributed ledger technology (DLT) functional assessment methods for assessment criteria proposed in [ITU-T F.751.1]. This Recommendation can be used as a guideline for DLT assessment. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T F.751.0] Recommendation ITU-T F.751.0 (2020), *Requirements for distributed ledger systems*. + +[ITU-T F.751.1] Recommendation ITU-T F.751.1 (2020), *Assessment criteria for distributed ledger technology platforms*. + +[ITU-T F.751.2] Recommendation ITU-T F.751.2 (2020), *Reference framework for distributed ledger technologies*. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 asset** [ITU-T F.751.0]: A representation of value. It can be a diamond, a unit of currency, items inside a shipping container, etc. An asset can be physical or virtual. + +**3.1.2 Byzantine fault tolerance** [ITU-T F.751.1]: Property that enables a system to continue operating properly even if some of its components fail or the existence of intentional bad actors. + +**3.1.3 consensus** [ITU-T F.751.0]: Agreement that a set of transactions is valid. + +**3.1.4 crash fault tolerance** [ITU-T F.751.1]: Property that enables a system to continue operating properly even if some of its components fail. + +**3.1.5 distributed ledger** [ITU-T F.751.0]: A type of ledger that is shared, replicated, and synchronized in a distributed and decentralized manner. + +**3.1.6 entity** [ITU-T F.751.0]: Anything that has a separately identifiable existence (e.g., organization, person, group, smart contract or device). An entity uses distributed ledger technology to solve the problem of its business or information systems. + +**3.1.7 node** [ITU-T F.751.0]: Device or process that participates in a distributed ledger network. + +**3.1.8 smart contract** [ITU-T F.751.0]: Program written on a distributed ledger system which encodes the rules for specific types of distributed ledger system transactions in a way that can be validated, and triggered by specific conditions. + +**3.1.9 token** [ITU-T F.751.0]: A digital representation of value on a shared distributed ledger that is owned and secured using cryptography to ensure its authenticity and prevent modification or tampering without the owner's consent. + +**3.1.10 transaction** [ITU-T F.751.0]: An incident or an operation that leads to a change in the status of a ledger, such as adding a record or equivalent exchange based on currency. + +### **3.2 Terms defined in this Recommendation** + +This Recommendation defines the following term: + +**3.2.1 peer-to-peer network:** A computer network comprised of nodes with equal control and operation capabilities. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-------|------------------------------------| +| BFT | Byzantine Fault Tolerance | +| CFT | Crash Fault Tolerance | +| DLT | Distributed Ledger Technology | +| HTTPS | Hypertext Transfer Protocol Secure | +| MSP | Management Server Platform | +| P2P | Peer-to-Peer | +| RPC | Remote Procedure Call | +| SDK | Software Development Kit | +| TLS | Transport Layer Security | + +## **5 Conventions** + +None. + +# **6 Overview of assessment methods** + +The assessment criteria defined in [ITU-T F.751.1] cover DLT core technology, application support, operation, performance, and ecosystem. The DLT assessment framework is shown in Figure 1 of [ITU-T F.751.1], and is reproduced as Figure 1 in this Recommendation. The aim of this Recommendation is to extend [ITU-T F.751.1] and to define specific test methods and test cases for DLT functional assessment. + +For each test case, the following three aspects are proposed: + +- test purpose, which clarifies the reason for this test case; +- test workflow, which specifies the test execution steps of this test case for the testers; and +- expected results, which specify the expected test consequences of this test case. + +![Figure 1 – Framework of assessment for DLT platforms. A hierarchical diagram showing assessment levels: Ecosystem, Application, Operation, Performance, and Infrastructure. Ecosystem includes Platform maturity, Open source, Maintenance, Availability of professionals, Running cost of DLT systems, and Avoid vendor lock-in. Application includes Application support (User authentication, System stability, Economic mechanism design, Information privacy, Application support functions, Transaction origin) and Core technology (Account creation, Private key management, Transaction processing, Smart contract mechanism, Query, Security of cryptography, Consensus mechanism effectiveness, Decentralisation). Operation includes Network management, Risk management and mitigation, and Data storage sustainability. Performance includes Metric definitions, Preconditions for performance evaluation, Transaction, and Test tools. Infrastructure is the base level.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +Figure 1 – Framework of assessment for DLT platforms. A hierarchical diagram showing assessment levels: Ecosystem, Application, Operation, Performance, and Infrastructure. Ecosystem includes Platform maturity, Open source, Maintenance, Availability of professionals, Running cost of DLT systems, and Avoid vendor lock-in. Application includes Application support (User authentication, System stability, Economic mechanism design, Information privacy, Application support functions, Transaction origin) and Core technology (Account creation, Private key management, Transaction processing, Smart contract mechanism, Query, Security of cryptography, Consensus mechanism effectiveness, Decentralisation). Operation includes Network management, Risk management and mitigation, and Data storage sustainability. Performance includes Metric definitions, Preconditions for performance evaluation, Transaction, and Test tools. Infrastructure is the base level. + +F.751.7(22) + +**Figure 1 – Framework of assessment for DLT platforms** + Reproduced from [ITU-T F.751.1] + +# 7 Core technology assessment methods + +### 7.1 Account creation + +**Table 1 – Account creation** + +| | | +|-------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 01 | Account creation | +| Reference | Clause 7.1 of [ITU-T F.751.1] | +| Test purpose | To validate DLT platform account creation ability. | +| Test workflow | Step 1. Create a user account, the private key is stored in ciphertext;
Step 2. Submit a transaction with the account created above, and verify the transaction execution result;
Step 3. Deploy a smart contract with the account created above. | +| Expected results | 1. The account was created successfully, private key was stored in ciphertext;
2. The transaction was submitted and executed successfully;
3. The smart contract was deployed successfully. | + +### 7.2 Transaction processing + +#### 7.2.1 Transaction processing flow + +**Table 2 – Transaction processing flow** + +| | | +|-------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 02 | Transaction processing flow | +| Reference | Clause 7.2 of [ITU-T F.751.1] | +| Test purpose | To validate the transaction process in the DLT platform. | +| Test workflow | Step 1. Construct and submit a transaction, and verify the transaction signature;
Step 2. Validate the broadcast process of the transaction;
Step 3. Validate the consensus and packaging process of the transaction;
Step 4. Validate the transaction verification process of the transaction;
Step 5. Validate the persistent storage of the transaction. | +| Expected results | 1. The transaction was constructed successfully and the transaction signature was correct;
2. The transaction was broadcasted to other nodes successfully;
3. The transaction was packaged and verified successfully;
4. The transaction was stored persistently. | + +### 7.3 Query + +#### 7.3.1 Query DLT basic information + +**Table 3 – Query DLT basic information** + +| | | +|-------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 03 | Query DLT basic information | +| Reference | Clause 7.3 of [ITU-T F.751.1] | +| Test purpose | To validate the ability to query basic information in the DLT platform. | +| Test workflow | Step 1. Check the current block height through a DLT browser or other methods;
Step 2. Check the original data of a specific block through a DLT browser or other methods;
Step 3. Check the block information by block hash or block height through a DLT browser or other methods. | +| Expected results | The basic information of DLT platform was obtained successfully, including block height and block data. | + +#### 7.3.2 Query DLT transaction information + +**Table 4 – Query DLT transaction information** + +| | | +|-------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 04 | Query DLT transaction information | +| Reference | Clause 7.3 of [ITU-T F.751.1] | +| Test purpose | To validate the ability to query transaction information in the DLT platform. | +| Test workflow | Step 1. Query the original information of the transaction by the transaction hash;
Step 2. Query the list of transactions in a specified block. | +| Expected results | 1. The transaction original information was obtained successfully;
2. The list of transactions was obtained successfully. | + +#### 7.3.3 Query DLT account information + +**Table 5 – Query DLT account information** + +| | | +|-------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 05 | Query DLT account information | +| Reference | Clause 7.3 of [ITU-T F.751.1] | +| Test purpose | To validate the ability to query the account information in the DLT platform. | +| Test workflow | Step 1. Check the list of accounts in the DLT platform;
Step 2. Check the account asset of an account address;
Step 3. Check the contracts list of the DLT platform;
Step 4. Check the details of a contract. | +| Expected results | 1. The account list and the account balance in the DLT platform were viewed successfully;
2. The contract list and the contract details in the DLT platform were viewed successfully. | + +### 7.4 Consensus algorithm effectiveness + +#### 7.4.1 Consensus algorithm declaration + +**Table 6 – Consensus algorithm declaration** + +| | | +|-------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 06 | Consensus algorithm declaration | +| Reference | Clause 7.4 of [ITU-T F.751.1] | +| Test purpose | To validate the consensus algorithms supported by the DLT platform. | +| Test workflow | Step 1. Display the consensus algorithms supported by the DLT platform, such as crash fault tolerance (CFT) consensus or Byzantine fault tolerance (BFT) consensus;
Step 2. Check the relevant codes and configuration files of the consensus algorithm;
Step 3. Construct and submit a transaction to verify the consensus algorithm supported in the system. | +| Expected results | 1. The relevant codes and configuration files of the consensus algorithms supported by the system were displayed successfully;
2. The transaction was sent successfully and the supported consensus algorithms were verified correctly. | + +#### 7.4.2 Consensus process with no crash and no Byzantine nodes + +**Table 7 – Consensus process with no crash and no Byzantine nodes** + +| | | +|-------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 07 | Consensus process with no crash and no Byzantine nodes | +| Reference | Clause 7.4.2 of [ITU-T F.751.1] | +| Test purpose | To validate the ability of reach consensus with no crash and no Byzantine nodes in the DLT platform | +| Test workflow | Step 1. Construct and submit a valid transfer request;
Step 2. Validate the transaction execution result;
Step 3. Construct and send an invalid transfer request, such as the transfer token is more than the balance;
Step 4. Validate the transaction execution result. | +| Expected results | 1. The consensus of the valid transfer request was reached successfully and the transaction was executed successfully;
2. The consensus of the invalid transfer request was reached unsuccessfully, but the transaction executed failed and reason for failure was given. | + +#### 7.4.3 Consensus process with crash nodes less than the threshold value + +**Table 8 – Consensus process with crash nodes less than the threshold value** + +| | | +|-------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 08 | Consensus process with crash nodes less than the threshold value | +| Reference | Clause 7.4.2 of [ITU-T F.751.1] | +| Test purpose | To validate the consensus ability when the number of crash nodes is less than the threshold value. | +| Test workflow | Step 1. Ensure that the number of crash nodes is less than the threshold value, the threshold value is the largest number of crash nodes that can be tolerated in the DLT platform;
Step 2. Construct and submit a transfer transaction to a non-crash node, then check the transaction execution result;
Step 3. Construct and submit a transfer transaction to a crash node, then check the transaction execution result. | +| Expected results | 1. The transaction submitted to the non-crash node was executed successfully and the consensus was reached successfully;
2. The transaction submitted to the crash node was executed failed and the reason for failure was given. | + +#### 7.4.4 Consensus process with crash nodes more than the threshold value + +**Table 9 – Consensus process with crash nodes more than the threshold value** + +| | | +|-------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 09 | Consensus process with crash nodes more than the threshold value | +| Reference | Clause 7.4.2 [ITU-T F.751.1] | +| Test purpose | To validate the consensus ability when the number of crash nodes is more than the theoretical value. | +| Test workflow | Step 1. Ensure that the number of crash nodes is greater than the threshold value, the threshold value is the largest number of crash nodes can be tolerated in the DLT platform;
Step 2. Construct and submit a valid transfer transaction to a non-crash node, then check the transaction execution result;
Step 3. Construct and submit a valid transfer transaction to a crash node, then check the transaction execution result. | +| Expected results | 1. The transaction submitted to the non-crash node was executed failed and reason for failure was given;
2. The transaction sent to the crash node was executed failed and the reason for failure was given. | + +### 7.5 Private key management + +#### 7.5.1 Software-based private key management + +**Table 10 – Software-based private key management** + +| | | +|---------------------|----------------------------------------------------------------------| +| Test case 10 | Software-based private key management | +| Reference | Clause 7.5.1 of [ITU-T F.751.1] | +| Test purpose | To validate the ability of private key management based on software. | + +**Table 10 – Software-based private key management** + +| | | +|-------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test workflow | Step 1. Generate a key pair by software, and store the private key in ciphertext;
Step 2. Construct and submit a transfer transaction using the created account and verify the transaction signature. | +| Expected results | 1. The key pair was generated successfully and the private key was stored in ciphertext;
2. The transaction was executed successfully and the transaction signature was verified successfully. | + +#### 7.5.2 Hardware-based privacy key management + +**Table 11 – Hardware-based private key management** + +| | | +|-------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 11 | Hardware-based private key management | +| Reference | Clause 7.5.2 of [ITU-T F.751.1] | +| Test purpose | To validate the ability of private key management based on hardware. | +| Test workflow | Step 1. Generate a key pair by hardware or software, then store the private key in hardware;
Step 2. Construct and submit a transfer transaction using the hardware client, and verify the transaction signature. | +| Expected results | 1. The private key was generated successfully, and stored in hardware client successfully;
2. The transaction was executed successfully and the transaction signature was verified successfully. | + +### 7.6 Smart contract mechanism + +#### 7.6.1 Complete lifecycle management of smart contract + +**Table 12 – Complete lifecycle management of smart contract** + +| | | +|-------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 12 | Complete lifecycle management of smart contract | +| Reference | Clause 7.6.2 of [ITU-T F.751.1] | +| Test purpose | To validate the complete lifecycle management of the smart contract. | +| Test workflow | Step 1. Compile and deploy a smart contract on the DLT platform;
Step 2. Invoke the smart contract by submitting a transaction;
Step 3. Freeze the contract and submit a transaction to invoke the contract;
Step 4. Unfreeze the contract and submit a transaction to invoke the contract;
Step 5. Destroy the contract and submit a transaction to invoke the contract. | +| Expected results | 1. The smart contract was compiled and deployed successfully;
2. The contract was invoked successfully by the transaction;
3. The contract was frozen, unfrozen, and destroyed successfully. | + +#### 7.6.2 Forward compatibility of smart contract operating mechanism + +**Table 13 – Forward compatibility of smart contract operating mechanism** + +| | | +|---------------------|-------------------------------------------------------------| +| Test case 13 | Forward compatibility of smart contract operating mechanism | +| Reference | Clause 7.6.1 of [ITU-T F.751.1] | + +**Table 13 – Forward compatibility of smart contract operating mechanism** + +| | | +|-------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test purpose | To validate the forward compatibility of the smart contract operating mechanism. | +| Test workflow | Step 1. Compile and deploy a smart contract in the DLT platform;
Step 2. Invoke the smart contract by submitting a transaction;
Step 3. Upgrade the DLT platform, then invoke the smart contract again by submitting a transaction. | +| Expected results | 1. The smart contract was deployed successfully on the DLT platform;
2. The contract was invoked successfully before DLT platform upgraded;
3. The contract was invoked successfully after DLT platform upgraded. | + +#### 7.6.3 Smart contract upgrade + +**Table 14 – Smart contract upgrade** + +| | | +|-------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 14 | Smart contract upgrade | +| Reference | Clause 7.6.3 of [ITU-T F.751.1] | +| Test purpose | To validate the ability of smart contract upgrade in the DLT platform | +| Test workflow | Step 1. Compile and deploy a smart contract in the DLT platform;
Step 2. Upgrade the smart contract, then invoke the upgraded smart contract by submitting a transaction. | +| Expected results | 1. The smart contract was deployed successfully;
2. The contract was upgraded successfully, and the smart contract invoked successfully. | + +### 7.7 Security of cryptography + +#### 7.7.1 Encryption declaration + +**Table 15 – Encryption declaration** + +| | | +|-------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 15 | Encryption declaration | +| Reference | Clause 7.7.1 of [ITU-T F.751.1] | +| Test purpose | To validate the encryption algorithms supported by the DLT platform. | +| Test workflow | Step 1. Display the default supported encryption algorithms, including hash algorithms, symmetric encryption algorithms, and asymmetric encryption algorithms;
Step 2. Construct and submit a transaction by the default algorithm, then check the transaction execution result. | +| Expected results | The transaction was constructed and submitted successfully, and the transaction was executed successfully. | + +#### 7.7.2 Pluggable encryption algorithm + +**Table 16 – Pluggable encryption algorithm** + +| | | +|---------------------|---------------------------------------------------------------------------| +| Test case 16 | Pluggable encryption algorithm | +| Reference | Clause 7.7.2 of [ITU-T F.751.1] | +| Test purpose | To validate optional encryption algorithms supported in the DLT platform. | + +**Table 16 – Pluggable encryption algorithm** + +| | | +|-------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test workflow |

Step 1. Display the optional encryption algorithms supported in the DLT platform, including hash algorithms, symmetric encryption algorithms, and asymmetric encryption algorithms;

Step 2. Construct and submit a transaction by any optional algorithms displayed above, then check the transaction execution result;

Step 3. Construct and submit a transaction by another algorithm, then check the transaction execution result.

| +| Expected results |

1. The transaction constructed and submitted by any optional algorithms successfully, and the transaction executed successfully;

2. The transaction constructed and submitted by another algorithm successfully, and the transaction executed successfully.

| + +### 7.8 Decentralization + +#### 7.8.1 Reduce the range of consensus + +**Table 17 – Reduce the range of consensus** + +| | | +|-------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 17 | Reduce the range of consensus | +| Reference | Clause 7.8 of [ITU-T F.751.1] | +| Test purpose | To validate the stability of the DLT platform after reducing the number of consensus nodes. | +| Test workflow |

Step 1. Reduce the number of consensus nodes in the DLT platform or convert consensus nodes into non-consensus nodes;

Step 2. Construct and submit a transaction, then check the transaction execution result.

| +| Expected results |

1. The number of consensus nodes was reduced successfully;

2. The transaction was executed successfully.

| + +#### 7.8.2 Expand the range of consensus + +**Table 18 – Expand the range of consensus** + +| | | +|-------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 18 | Expand the range of consensus | +| Reference | Clause 7.8 of [ITU-T F.751.1] | +| Test purpose | To validate the expansion capabilities of consensus scope. | +| Test workflow |

Step 1. Increase the number of consensus nodes in the DLT platform, such as by adding a new consensus node or converting a non-consensus node to consensus node;

Step 2. Construct and submit a transaction, then validate the transaction execution result.

| +| Expected results |

1. The new consensus node was added successfully, and the number of consensus nodes was increased successfully;

2. The transaction was executed successfully.

| + +## 8 Application support assessment methods + +### 8.1 User authentication + +**Table 19 – User authentication** + +| | | +|-------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 19 | User authentication | +| Reference | Clause 8.1 of [ITU-T F.751.1] | +| Test purpose | To validate the user management and authentication of DLT platform. | +| Test workflow | Step 1. Create a user account with the necessary information, such as public key, address, etc.
Step 2. Login in the DLT platform using the account created above, then check the authentication result. | +| Expected results | The user account was created and authenticated successfully. | + +## 8.2 System stability + +**Table 20 – System stability** + +| | | +|-------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 20 | System stability | +| Reference | Clause 8.2 of [ITU-T F.751.1] | +| Test purpose | To test the stability of DLT platform. | +| Test workflow | Step 1. Submit transactions to the DLT network with a certain pressure, then execute the following steps;
Step 2. Create a new node and join the existing DLT network, then submit a transaction and verify the transaction execution result;
Step 3. Exit a node from the existing DLT network, submit a transaction and verify the transaction execution result;
Step 4. Upgrade a node from the existing DLT network, submit a transaction and verify the transaction execution result. | +| Expected results | 1. The node was joined successfully, and the transaction was executed successfully;
2. The node was exited successfully, and the transaction was executed successfully;
3. The node was upgraded successfully, and the transaction was executed successfully. | + +### 8.3 Economic mechanism design + +**Table 21 – Economic mechanism design** + +| | | +|----------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 21 | Economic mechanism design | +| Reference | Clause 8.3 of [ITU-T F.751.1] | +| Test purpose | To validate the economic mechanism of DLT platform. | +| Test workflow | Step 1. Display the economic mechanism of the DLT platform, including financial incentives and non-financial incentives;
Step 2. Validate the lifecycle management mechanism of the token in the DLT platform, including token issuance, token transfer, token withdrawal, token settlement, as well as token querying. | + +**Table 21 – Economic mechanism design** + +| | | +|-------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Expected results | 1. The economic mechanism of the DLT platform was verified successfully, and incentives were provided when the process was completed;
2. The token was issued successfully, some of the token was transferred successfully, and the token balance was queried successfully. | +|-------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| + +### 8.4 Information privacy + +#### 8.4.1 Secure transmission + +**Table 22 – Secure transmission** + +| | | +|-------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 22 | Secure transmission | +| Reference | Clause 8.4.1 of [ITU-T F.751.1] | +| Test purpose | To validate the secure transport protocols for information transmission in DLT platform. | +| Test workflow | Step 1. Display the secure transmission protocols in the DLT platform, such as transport layer security (TLS), hypertext transfer protocol secure (HTTPS), etc.;
Step 2. Check the secure transmission protocols, including the key codes and configuration files;
Step 3. Check the information transmitted to verify the encrypted status. | +| Expected results | 1. The key codes and configuration files were valid;
2. The information was transmitted in ciphertext. | + +#### 8.4.2 Restricted data access + +**Table 23 – Restricted data access** + +| | | +|-------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 23 | Restricted data access | +| Reference | Clause 8.4.2 of [ITU-T F.751.1] | +| Test purpose | To validate the data access control and security protection mechanism of the DLT platform. | +| Test workflow | Step 1. Display the data access control and security protection solutions of the DLT platform;
Step 2. Verify the data access control and security protection capabilities of the DLT platform, including:
a) Check the data encryption storage, such as symmetric passwords, asymmetric passwords, and hash algorithms;
b) Check the secure management of keys;
c) Verify the user rights to ensure that data access can be controlled. | +| Expected results | 1. The data was stored in the DLT platform encrypted;
2. The keys were managed securely in the DLT platform;
3. The data with rights are visible, and the data without rights are invisible. | + +#### 8.4.3 Privacy protection + +**Table 24 – Privacy protection** + +| | | +|-------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 24 | Privacy protection | +| Reference | Clause 8.4.3 of [ITU-T F.751.1] | +| Test purpose | To validate the privacy protection algorithms of the DLT platform. | +| Test workflow | Step 1. Display the types and details of the privacy protection algorithms of the DLT platform, such as zero-knowledge proofs, ring signatures, secure multi-party computation and homomorphic encryption;
Step 2. Check the privacy protection algorithms, including the key code and configuration files;
Step 3. Invoke the algorithm interface of the DLT platform and encrypt the data. | +| Expected results | 1. The key code and configuration files of the privacy protection algorithms were valid and complete;
2. The interface was invoked and the data was encrypted successfully by the privacy protection algorithms. | + +### 8.5 Application support functions + +#### 8.5.1 User interface + +**Table 25 – User interface** + +| | | +|-------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 25 | User interface | +| Reference | Clause 8.5 of [ITU-T F.751.1] | +| Test purpose | To test the user interface provided by DLT platform. | +| Test workflow | Step 1. Display the types of user interfaces provided by the DLT platform, such as HTTP, remote procedure call (RPC), etc.;
Step 2. Check the key code of the user interfaces;
Step 3. Invoke the user interface, submit a transaction and verify the transaction execution result. | +| Expected results | 1. The key code of the user interfaces was valid and complete;
2. The interface was invoked, with the transaction submitted and executed successfully. | + +#### 8.5.2 Multi-language software development kits + +**Table 26 – Multi-language software development kits** + +| | | +|----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 26 | Multi-language software development kits | +| Reference | Clause 8.5 of [ITU-T F.751.1] | +| Test purpose | To validate multi-language software development kits (SDK) supported by the DLT platform. | +| Test workflow | Step 1. Display the multi-language SDK supported by the DLT platform, and the supported language of the SDK;
Step 2. Check the key code of the multi-language SDK;
Step 3. Invoke the multi-language SDK, submit a transaction and verify the transaction execution result. | + +| | | +|-------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Expected results | 1. The key code of the multi-language SDK was valid and complete;
2. The multi-language SDK was invoked, with the transaction submitted and executed successfully. | +|-------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------| + +### 8.6 Transaction origin + +**Table 27 – Transaction origin** + +| | | +|-------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 27 | Transaction origin | +| Reference | Clause 8.6 of [ITU-T F.751.1] | +| Test purpose | To validate capabilities for identifying the origin of transactions of DLT platform. | +| Test workflow | Step 1. Display the mechanism for identifying the origin node and account address of transactions;
Step 2. Submit a transaction and verify the transaction execution result;
Step 3. Identify the original node and account address of the transaction. | +| Expected results | 1. The transaction was submitted and executed successfully;
2. The original node and account address of the transaction were identified. | + +# 9 Operation assessment methods + +### 9.1 Network management + +**Table 28 – Network management** + +| | | +|-------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 28 | Network management | +| Reference | Clause 9.1 of [ITU-T F.751.1] | +| Test purpose | To validate the node management and monitor capabilities in the DLT platform. | +| Test workflow | Step 1. Add a new node in the DLT platform and check the new node in the DLT platform;
Step 2. View the node monitoring. | +| Expected results | 1. The number of nodes was increased successfully according to the node management mechanism;
2. The node information was displayed according to the node monitoring mechanism. | + +### 9.2 Risk management and mitigation + +**Table 29 – Risk management and mitigation** + +| | | +|----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 29 | Risk management and mitigation | +| Reference | Clause 9.2 of [ITU-T F.751.1] | +| Test purpose | To validate the data backup and fault recovery capabilities in the DLT platform. | +| Test workflow | Step 1. Make a data backup;
Step 2. Trigger the data recovery mechanism manually or automatically;
Step 3. Validate the effectiveness of the data recovery mechanism, including data integrity and consistency. | + +| | | +|-------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Expected results | 1. The data backup was executed successfully;
2. The data recovery mechanism was triggered successfully;
3. The data recovery mechanism was effective and the data was completely recovered. | +|-------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| + +### 9.3 Data storage sustainability + +**Table 30 – Data storage sustainability** + +| | | +|-------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 30 | Data storage sustainability | +| Reference | Clause 9.3 of [ITU-T F.751.1] | +| Test purpose | To validate the data persistent storage and data query capabilities in the DLT platform. | +| Test workflow | Step 1. Construct and submit a transfer transaction to validate the persistent storage capability in the DLT platform;
Step 2. Construct and submit a query transaction to validate the data query capability in the DLT platform. | +| Expected results | 1. The transfer transaction was executed successfully;
2. The query transaction was executed successfully. | + +# 10 Ecosystem assessment methods + +## 10.1 Platform maturity + +**Table 31 – Platform maturity** + +| | | +|-------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 31 | Platform maturity | +| Reference | Clause 11.1 of [ITU-T F.751.1] | +| Test purpose | To validate the DLT platform maturity status. | +| Test workflow | Step 1. Check construction start time and calculate maintenance period of the DLT platform;
Step 2. Check the network scale, the number of users, and the number of smart contracts of the DLT platform;
Step 3. Evaluate the DLT platform values, including economic value and social value. | +| Expected results | 1. The DLT platform was constructed early;
2. The network scale of the DLT platform was large, the number of users was large, and the number of smart contracts was large;
3. The DLT platform has great economic value or social value. | + +### 10.2 Open source + +**Table 32 – Open source** + +| | | +|---------------------|-------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 32 | Open source | +| Reference | Clause 11.2 of [ITU-T F.751.1] | +| Test purpose | To validate the DLT platform open-source status, including license, code hosting platform, and repository address. This case is optional. | + +**Table 32 – Open source** + +| | | +|-------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test workflow |

Step 1. Display the open-source status, including the code hosting platform, repository address, and license;

Step 2. Check the code repository and verify the license at the specified open-source address;

Step 3. Go to the specified open-source address and check the consistency of the key code and the testing system.

| +| Expected results |

1. Codes of the DLT platform have been open-sourced and hosted on the open-source platform;

2. The repository address and open-source license were valid, codes hosted in the specified repository were consistent with the DLT platform.

| + +### **10.3 Maintenance** + +**Table 33 – Maintenance** + +| | | +|-------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Test case 33 | Maintenance | +| Reference | Clause 11.3 of [ITU-T F.751.1] | +| Test purpose | To validate the maintainability of the DLT platform. | +| Test workflow |

Step 1. Check the update records of the code, including the code committing records, branch changing records, and version releasing records;

Step 2. Check the discussion records of core issues, and check contributors changing records.

| +| Expected results |

1. The core codes of the DLT platform were updated recently, and new version was released recently;

2. Core issues were discussed recently, and the core contributors were stable.

| + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication 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featuring the letters 'ITU' in blue inside a circular emblem with a globe and network lines. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.751.9 + +# Trusted execution environment based confidential computing on distributed ledger technology systems + +## Summary + +Recommendation ITU-T F.751.9 specifies a trusted execution environment based confidential computing on distributed ledger technology systems. In addition, this Recommendation: + +- decomposes users' confidentiality demand into concrete requirements for each step during distributed ledger technology (DLT) service utilization; +- analyses detailed security requirements and technical requirements of trusted execution environment based confidential computing to guarantee confidentiality in the life cycle of a transaction from end to end; +- addresses the framework of trusted execution environment based confidential computing, as well as detailed procedures to realize security requirements and technical requirements. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.751.9 | 2023-09-13 | 16 | 11.1002/1000/15623 | + +## Keywords + +Confidential computing, distributed ledger technology, trusted execution environment. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2023 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-------------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Overview of confidential computing on a DLT system ..... | 2 | +| 7 Security requirements ..... | 3 | +| 7.1 Safety assurance of computing elements..... | 3 | +| 7.2 Security assessment to guarantee secure implementation ..... | 4 | +| 8 Technical requirements of TEE-based confidential computing ..... | 4 | +| 9 General framework of TEE-based confidential computing..... | 5 | +| 10 General procedures to realize TEE-based confidential computing ..... | 6 | +| 10.1 Preliminary ..... | 7 | +| 10.2 Key management ..... | 7 | +| 10.3 Transaction initiation..... | 9 | +| 10.4 Confidential computing execution ..... | 10 | +| 10.5 Receipt return ..... | 10 | +| Appendix I – Example of key specification..... | 11 | +| I.1 Root key specification example..... | 11 | +| Bibliography..... | 16 | + + + +# Recommendation ITU-T F.751.9 + +## Trusted execution environment based confidential computing on distributed ledger technology systems + +## 1 Scope + +This Recommendation specifies trusted execution environment based confidential computing on distributed ledger technology (DLT) systems. It includes an overview, requirements, framework, and procedures for trusted execution environment based confidential computing on DLT systems. + +This Recommendation is intended for use as guidance by the relevant parties for trusted execution environment based confidential computing. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 distributed ledger** [b-ITU-T F.751.0]: A type of ledger that is shared, replicated, and synchronized in a distributed and decentralized manner. + +**3.1.2 smart contract** [b-ITU-T X.1400]: Program written on a distributed ledger system which encodes the rules for specific types of distributed ledger system transactions in a way that can be validated and triggered by specific conditions. + +**3.1.3 transaction** [b-ITU-T X.1400]: Whole of the exchange of information between nodes. A transaction is uniquely identified by a transaction identifier. + +### 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 confidential computing**: Technology that executes data operations while protecting the confidentiality and integrity of sensitive data. + +**3.2.2 on-chain**: Located, performed, or run inside a distributed ledger technology system. + +**3.2.3 off-chain**: Related to a distributed ledger technology (DLT) system, but located, performed or run outside that DLT system. + +**3.2.4 trusted execution environment (TEE)**: A secure area on the main processor of a device that ensures sensitive data is stored, processed, and protected in an isolated and trusted environment. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +DLT Distributed Ledger Technology + +TEE Trusted Execution Environment + +## 5 Conventions + +The following conventions are used in this Recommendation: + +- The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted, if conformance to this Recommendation is to be claimed; +- The keywords "is recommended to" indicate a requirement that is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance; +- The keyword "functions" is defined as a collection of functionalities. + +## 6 Overview of confidential computing in a DLT system + +Distributed ledger technology (DLT) provides a tamper-resistant, definitive and traceable capability to service consumers, which can be utilized to build up trusted relationships among multiple business parties. To reach network consensus, data is shared among nodes in the DLT system, while in many realistic scenarios, the involved participants demand confidentiality protection of their sensitive data, as well as the related operations. Furthermore, the data that needs to be kept secret differs in various business scenarios, so customizable protection is required. For instance, an enterprise that submits a financing application, requires that their critical business information is only accessible to the financing related party e.g., a bank. In another example, two companies who achieve strategic cooperation, do not want to expose their identities and agreement signing. + +Diving into the procedure of a DLT service, concrete requirements are identified for each operation step of a complete DLT service: + +- DLT users start to use a specific service by submitting a transaction request message to the DLT platform. Sender account information, concrete business related transaction data (for example remittance amount or logistic evidence), and receiver account information are contained in the request message. Users are reluctant to expose this critical data, since competitors may also have registered in this platform and may acquire these secret trade materials. Consequently, secure protection of user defined fields in the request message should be enabled at the computing initiation stage. +- After receiving a request, the DLT platform fetches parameters from the request or from storage, loads the corresponding computing codes and executes computations based on agreements among different stakeholders. The process of executing the computations e.g., the computation environment, or interaction with the storage, may be prone to various attacks. For instance, sensitive business data or computing results may be intercepted by rivals, or computing codes may be tampered with by malicious hackers. This will result in data leakage and business accidents. On the other hand, the computing code may be flawed, in the forms of accidentally output confidential data or triggering of double spends of digital assets. More seriously, it may cause significant financial losses such as through re-entry attacks to drain the sender's account. Consequently, at this stage, the security of the computation execution environment and the correctness of the computation code should be guaranteed to protect the data and the related operations, e.g., calculation, writing, reading, etc. + +- Finally, the transaction receipt is returned to transaction initiator. Critical data, such as the computation result, the queried data, or computation execution logs, etc. is attached to the receipt, which should also be kept secret from unauthorised users. + +![Figure 1: An overview of TEE-based confidential computing in a DLT system. The diagram shows a DLT user at the top interacting with a DLT system below. The user sends a 'Transaction request, where the sensitive information is encrypted' to the system and receives a 'Receipt with result, where the sensitive information is encrypted'. The DLT system is a box labeled 'On-chain computing execution' containing four nodes. Each node has a 'Storage' unit (cylinder icon) and a 'Computing engine' (server icon) protected by a 'TEE' (Trusted Execution Environment) shield icon. The nodes are interconnected by dashed lines. One node's storage is shown exchanging 'Encrypted intermediate data' with its computing engine. The label 'DLT system' is at the bottom right of the system box, and 'F.751.9(23)' is at the bottom right corner.](acfc53eca625d62b38aa2563efa95c3e_img.jpg) + +Figure 1: An overview of TEE-based confidential computing in a DLT system. The diagram shows a DLT user at the top interacting with a DLT system below. The user sends a 'Transaction request, where the sensitive information is encrypted' to the system and receives a 'Receipt with result, where the sensitive information is encrypted'. The DLT system is a box labeled 'On-chain computing execution' containing four nodes. Each node has a 'Storage' unit (cylinder icon) and a 'Computing engine' (server icon) protected by a 'TEE' (Trusted Execution Environment) shield icon. The nodes are interconnected by dashed lines. One node's storage is shown exchanging 'Encrypted intermediate data' with its computing engine. The label 'DLT system' is at the bottom right of the system box, and 'F.751.9(23)' is at the bottom right corner. + +**Figure 1 – An overview of TEE-based confidential computing in a DLT system** + +The trusted execution environment (TEE) is a secure area in the processor to provide confidentiality and integrity of the code and data inside. TEE is easily programmable and widely utilized. As illustrated in Figure 1, each node deploys a TEE, and these nodes compose a DLT system with TEE-based confidential computing. TEE can provide sensitive data protection in various practical scenarios with guaranteed system performance. From a user point view, if there is sensitive business data, the transaction request is submitted with encrypted bit fields to protect the sensitive data. During the execution stage, there is a data exchange between the TEE and storage, any intermediate data during the exchange is encrypted. After the transaction execution, the receipt with result is fed back to the user, where the sensitive data is also encrypted. In this Recommendation, the security and technical requirements, framework, and detailed procedure of TEE-based confidential computing on a DLT system are discussed to satisfy users' confidentiality requirements during a complete DLT service. + +## 7 Security requirements + +The application-level requirements of DLT users are first mapped to the security requirements of TEE-based confidential computing. + +### 7.1 Security assurance of computing elements + +A DLT system with TEE-based confidential computing is required to guarantee the confidentiality and integrity of data during transmission, storage, calculation, and other operations: + +- data are encrypted when being sent outside the TEE; +- with the exception of authorized users, other participants cannot access it; +- when the calculation is executed within limited nodes, the data is only shared or stored within these restricted nodes; +- any malicious attacks on data are successfully detected and prevented from disclosure. + +The security of transaction codes are required to be guaranteed: + +- with the exception of eligible nodes, unauthorized nodes cannot access the transaction code; +- code auditing is required to ensure that the implemented function is consistent with the designed algorithm; +- before running the transaction code, the integrity of the transaction code is checked in case of any malicious tampering. + +The security of the computing operation is required to be guaranteed: + +- the operation is performed inside a trusted execution environment; +- the confidential transaction execution is isolated from the plaintext transaction, and their codes cannot call each other. + +### 7.2 Security assessment to guarantee secure implementation + +Security assessment is defined as grounds for justified confidence that a claim about meeting security objectives has been or will be achieved. Security assessment techniques should be adopted for measuring security properties and providing confidence levels of security assurances for the whole system from the following aspects: + +- **Secure assessment of system implementation:** Code analysis techniques are utilized to scan for security loopholes such as memory leakage, in the implemented system. Such techniques usually refer to static analysis (e.g., symbolic execution) and dynamic analysis (e.g., fuzzing, concolic testing); +- **Confidentiality proofing of security protocols:** A security protocol means an agreed sequence of actions are performed in order to accomplish the desired goals by using cryptographic techniques. Security protocols are widely used during confidential computing execution on the DLT system, e.g., encryption keys exchange, encrypted transaction initiation, encrypted receipt feedback. Manual proving or formal verification should be used to verify the confidentiality of all involved protocols in each stage of computing, so as to proof the security protection of sensitive data and avoid any potential leakage; +- **Confidentiality auditing of computing code:** Computing code is usually executed inside an isolated secure environment (e.g., TEE). It is the code used for performing requested business logic. Sensitive information could be leaked in the computation results through direct leaking (returned as result) or indirect leaking (inferred from results). For example, if the total avenue is confidential while the computing code outputs the day average and the date range, then the total avenue is leaked. Such a situation is categorized as indirect leaking. Techniques to perform confidentiality auditing include an expert code review or program interpretation and verification. + +## 8 Technical requirements of TEE-based confidential computing + +In addition to security requirements, the technical requirements of TEE-based confidential computing are also analysed to ensure an accurate and correct computing process. Technical requirements include: + +**Auditability:** Confidential computing is required to be pre and post audited to meet audit requirements, e.g., internal control, responsibility identification, event traceability, and so on. + +**Backward compatibility and forward secrecy:** It is required to provide backward compatibility with the premise of ensuring forward secrecy. The data generated by a certain version of computing code should be able to be accessed by updated versions, but should not be accessed by previous versions. + +**Co-existence:** The transaction under confidential protection is required to co-exist with plaintext transaction, and can be committed to the one ledger block. + +**Correctness.** After confidential protection, the transaction is required to be correctly executed and the same result is obtained as the transaction in the plaintext manner. + +**Consistency:** Since transactions are constantly appended into the ledger, the world status as well as the transaction results, are required to be consistent among distributed nodes under protected data conditions. + +**Flexibility:** The sensitive information in the request or receipt which needs to be protected during calculation processing, is required to be flexibly adjusted based on practical business requirements. The encrypted data stored on chain is required to be flexibly granted to eligible DLT users so as to support more business scenarios with guaranteed secure assurance, e.g., shared computation, and multiple party secure computation. + +**Generality:** Confidential computing is required to be adaptive to different utilization scenarios by substituting computing code, and supporting transactions with complex business logic. + +**Governance compliance:** The confidential transaction is required to adhere to governance requirements, e.g., information risk management, accountabilities, incentives, and so on. + +**Scalability:** The efficiency, capacity and functionality of the confidential transaction on the DLT platform is required to be improved through dynamic node additions and deletion, storage extension, etc. The confidential transaction can be extended to more scenarios, including interoperability between on-chain and off-chain systems, and cross DLT systems. + +## 9 General framework of TEE-based confidential computing + +To satisfy the technical and security requirements, a framework of TEE-based confidential computing is illustrated in the Figure 2. + +The roles of confidential computing consist in: + +- **Trusted remote server:** It performs remote attestation of TEE. In the case of centralized key management, it also distributes cryptographic parameters to TEE for secure channel establishment among nodes, between the user and node; +- **DLT users:** They access the confidential computing service by initiating a transaction request. It will send the transaction request and receive the corresponding receipt, where the critical information in the request and receipt is protected; +- **DLT system:** It consists of multiple DLT nodes, while TEE is deployed to provide a confidential computing service to the DLT user. + +![Figure 2: The framework of TEE-based confidential computing. The diagram shows a 'DLT system' box containing four layers: 'API layer' (top), 'Platform layer' (middle), 'Infrastructure layer' (bottom), and 'Cross layer functions' (right). The 'Platform layer' contains a 'TEE' (Trusted Execution Environment) box with six components: 'Transaction pre-processor', 'Computing engine', 'Local/remote attestation', 'Key management', 'Code management', and 'Secure data module'. Outside the TEE but inside the Platform layer are 'Distributed ledger', 'Consensus mechanism', and 'P2P service'. The 'Cross layer functions' box contains 'Security', 'Management and operations', 'Development', and 'Governance and compliance'. Above the DLT system box are two external boxes: 'Trusted remote server' and 'DLT users'. A label 'F.751.9(23)' is at the bottom right.](d4af765160d04ecef538e5066006dc77_img.jpg) + +Figure 2: The framework of TEE-based confidential computing. The diagram shows a 'DLT system' box containing four layers: 'API layer' (top), 'Platform layer' (middle), 'Infrastructure layer' (bottom), and 'Cross layer functions' (right). The 'Platform layer' contains a 'TEE' (Trusted Execution Environment) box with six components: 'Transaction pre-processor', 'Computing engine', 'Local/remote attestation', 'Key management', 'Code management', and 'Secure data module'. Outside the TEE but inside the Platform layer are 'Distributed ledger', 'Consensus mechanism', and 'P2P service'. The 'Cross layer functions' box contains 'Security', 'Management and operations', 'Development', and 'Governance and compliance'. Above the DLT system box are two external boxes: 'Trusted remote server' and 'DLT users'. A label 'F.751.9(23)' is at the bottom right. + +**Figure 2 – The framework of TEE-based confidential computing** + +Each DLT node can be divided into API layer, platform layer, infrastructure layer, and cross-layer functions: + +- API layer contains functions that provide reliable and efficient access to the DLT system for users. +- DLT platform layer contains the TEE module and other core services, such as the consensus mechanism, distributed ledger, peer-to-peer (P2P) communication service and so on. TEE provides an isolated and secure environment, so that the confidentiality and integrity of data are guaranteed, and the execution procedure will not be interfered with by normal operating systems or other privileged system components: + - transaction pre-processor decrypts and verifies the given transaction; + - computing engine executes confidential codes; + - key management includes a set of key operations, e.g., key storage, or updating; + - data security module manages confidentiality and integrity of data; + - code management involves a set of code operations, e.g., code version management, code integrity validation; + - either local or remote attestation proves the identity legitimacy of TEE. +- The infrastructure layer provides the operating environment, e.g., storage components. During the execution processing, encrypted business-related data, code, contract status and results will be exchanged between the computing engine and storage; +- Cross layer functions support the components across all the functional layers, e.g., management operations, development, governance and compliance. + +## 10 General procedures to realize TEE-based confidential computing + +Finally, the detailed procedures of confidential computing to realize security requirements and technical requirements are addressed. The confidential computing procedure consists of three main stages, transaction initiation, calculation execution, and receipt feedback: + +- TEE in nodes shall be attested and configured so as to provide a secure environment for transaction processing. The key is generated and synchronized among TEE nodes; +- DLT users build up the secure channel with the DLT platform and transmit the transaction request; +- DLT platform provides a secure computing engine to execute the confidential calculation based on the request, which involves encrypted code and data exchange between the computing engine and storage. For more details refer to clause 10.4; +- Finally, the receipt containing the calculation result is fed back to the initiators. + +![Sequence diagram illustrating the General TEE-based confidential computing procedure. The diagram shows interactions between DLT user(s), TEE module, and Storage. The steps are: 0. Management of TEE attestation, configuration and key (internal to TEE module); 1. Establish a secure communication channel (between DLT user(s) and TEE module); 2. Submit a transaction with encrypted sensitive information (from DLT user(s) to TEE module); 3. Computation execution (between TEE module and Storage, involving encrypted code or data interaction); 4. Reply a transaction receipt with encrypted execution result (from TEE module to DLT user(s)).](4e4be0bd8b235167902f2c03e41da651_img.jpg) + +``` + +sequenceDiagram + participant DLT user(s) + participant TEE module + participant Storage + + Note right of TEE module: 0. Management of TEE attestation, configuration and key + DLT user(s)->>TEE module: 1. Establish a secure communication channel + DLT user(s)->>TEE module: 2. Submit a transaction with encrypted sensitive information + Note right of TEE module: 3. Computation execution + TEE module->>Storage: Encrypted code or data interaction + Storage-->>TEE module: + TEE module->>DLT user(s): 4. Reply a transaction receipt with encrypted execution result + +``` + +F.751.9(23) + +Sequence diagram illustrating the General TEE-based confidential computing procedure. The diagram shows interactions between DLT user(s), TEE module, and Storage. The steps are: 0. Management of TEE attestation, configuration and key (internal to TEE module); 1. Establish a secure communication channel (between DLT user(s) and TEE module); 2. Submit a transaction with encrypted sensitive information (from DLT user(s) to TEE module); 3. Computation execution (between TEE module and Storage, involving encrypted code or data interaction); 4. Reply a transaction receipt with encrypted execution result (from TEE module to DLT user(s)). + +**Figure 3 – General TEE-based confidential computing procedure** + +### 10.1 Preliminary + +Before confidential computing starts up, the TEE in nodes shall be attested and configured, as in steps 0 and 1 in Figure 3, with necessary cryptographic parameters, so that a secure channel can be set up between users and nodes, as well as inter nodes: + +- the TEE is registered in the trusted key management server; +- when a node joins the DLT network, the necessary cryptographic parameters are directly distributed to the TEE and stored inside a specific secure domain after successful attestation by a trusted remote server. These cryptographic parameters can be chain specific or traffic specific. They can be utilized for either one type or multiple types of business transaction according to configuration. + +### 10.2 Key management + +TEEs are a secure environment where the executed applications can ensure that their code and data are not accessed or tampered with by malicious software or unauthorized applications. Therefore, key management is crucial to protect the confidentiality and integrity of applications and data in TEEs. The key management can be implemented through either a centralized or distributed manner. + +Distributed key service is designed to address the need for negotiating and using keys in DLT systems. It is based on a distributed deployment architecture and a multi-node key negotiation protocol, which achieves the goal of sharing secret keys across the entire network through the protocol. + +A distributed key management system is implemented to realize full lifecycle management of the decentralized key. The key is used inside the TEEs, and the plaintext information of the key cannot be obtained outside the TEEs. + +#### 10.2.1 Key generation + +The key is securely generated based on the pre-defined root key specification, see Appendix I. Root key specification contains key information, derivation policies, synchronization policies and so on, as shown in Appendix I. + +- According to root key specification, the root key is generated inside the TEE of one DLT node, together with the proof report. The proof report proves the security and correctness of the key generation process, including the TEE environment, key generation program, the hash of the key, etc.; +- The root key and key related policies are encrypted and stored as a composed key outside the TEE, as well as the plaintext proof report; +- The proof report is shared to other nodes, and then a TEE-specific DLT can start. + +![Sequence diagram of distributed key generation procedure](a33da0f14e456f92539ce3e9b7d81f9a_img.jpg) + +The diagram illustrates the distributed key generation procedure between a 'One node' (containing a 'TEE module') and 'Other nodes'. The sequence of events is as follows: + +1. Root key is generated inside TEE, together with proof report +2. Composed key is encrypted and stored outside TEE +3. The report is shared to other nodes + +The diagram is labeled F.751.9(23). + +Sequence diagram of distributed key generation procedure + +**Figure 4 – Distributed key generation procedure** + +#### 10.2.2 Key synchronization + +When a node starts, the TEE first tries to check whether the correct key exists. If there is a correct key, it can then launch local configuration and work normally. It can also serve as a server to provide key synchronization services to other nodes inside the DLT network. + +If a node does not have the correct key, it will request key synchronization from other nodes: + +- The requestor node sends a query message to a responder node for key synchronization; +- If the responder can synchronize a composed key, TEEs perform a bidirectional remote attestation to check that the peer is the claimed correct TEE environment; +- A secure channel between TEEs is set up, which guarantees the composed key is synchronized securely. The TEE inside the responder node sends the composed key to the TEE inside the requestor node; +- The TEE inside the requestor node checks the authenticity and integrity of the shared composed key, together with the proof report; +- Finally, the success notification is sent back. + +Figure 5 shows the key synchronization procedure. + +![Sequence diagram of the key synchronization procedure between a Requestor node and a Responder node, both containing TEE modules. The process involves five steps: 1. Key synchronization request, 2. Bidirectional remote attestation, 3. Share composed key, 4. Validation, and 5. Success. A shaded area labeled 'Secure channel between TEEs' covers steps 3, 4, and 5. The diagram is labeled F.751.9(23).](33ed1f9b27c7c21c797aa928b0f06851_img.jpg) + +``` + +sequenceDiagram + participant Requestor as Requestor node + participant Responder as Responder node + Note over Requestor, Responder: TEE module in each + Requestor->>Responder: 1. Key synchronization request + Requestor<<->>Responder: 2. Bidirectional remote attestation + rect rgb(230, 230, 230) + Note right of Responder: Secure channel between TEEs + Responder->>Requestor: 3. Share composed key + Requestor->>Requestor: 4. Validation + Requestor->>Responder: 5. Success + end + +``` + +F.751.9(23) + +Sequence diagram of the key synchronization procedure between a Requestor node and a Responder node, both containing TEE modules. The process involves five steps: 1. Key synchronization request, 2. Bidirectional remote attestation, 3. Share composed key, 4. Validation, and 5. Success. A shaded area labeled 'Secure channel between TEEs' covers steps 3, 4, and 5. The diagram is labeled F.751.9(23). + +**Figure 5 – Key synchronization procedure** + +#### 10.2.3 Key utilization + +Before starting business, the application needs to apply for a business key through the DLT system: + +- The application declares the business key specification, e.g., key size, derive policies, usage constraints, and backup and recovery strategies, see Appendix I; +- After the administrator approves the application, the business key specification is shared to each node; +- Each node derives the same business key independently inside the TEE; +- Secure channels based on business key are set up, and execute the business operations. + +#### 10.2.4 Key backup and recovery + +To ensure key usability and security, key backup and recovery is recommended to be supported: + +- The composed key is divided into $M$ shares, and $N$ shares can reconstruct the complete root key, where $1 \leq N \leq M$ ; +- TEE sends a request for key recovery to the administrator, as well as self-proofing; +- The administrator verifies the authenticity and integrity of the request; +- If passed, administrator sends the composed key shares; +- The composed key is recovered inside the TEE. + +### 10.3 Transaction initiation + +The transaction request is sent from the DLT user to the DLT platform, where sensitive information in the request is encrypted: + +- the transaction request is sent from the DLT user to the DLT platform, where sensitive information in the request is encrypted; +- the node detects whether this is a confidential type or not. If yes, the given transaction is sent into the trusted execution environment (TEE); +- in the TEE, the request message is decrypted and the integrity is checked. + +### **10.4 Confidential computing execution** + +#### **10.4.1 Transaction code instalment** + +The DLT user can attach computing codes in the transaction request message for deployment when there is no available code on the DLT platform: + +- contract codes are extracted from the request message within the TEE; +- the corresponding contract accounts are created; +- the computing codes within TEE are encrypted, and then sent out to a storage module for later utilization. + +#### **10.4.2 Computing code operation** + +When the computing code is ready, it will be loaded into the TEE and executed accordingly to: + +- extract the data from the request message; +- optionally, load the encrypted data from storage, decrypt it and check the integrity; +- load the corresponding computing code from storage in the encrypted manner, decrypt it and check the integrity; +- run code together with all necessary parameters. In this step, some intermediate data may be exchanged between the TEE module and storage; +- encrypt the result or contract state, and send it to storage. + +NOTE – The plaintext code or data is only visible within the TEE. It shall be encrypted before it is sent outside the TEE. + +#### **10.4.3 Computing code updating** + +When computing codes need to be upgraded due to a flaw or function upgrading, the DLT user attaches the updated code in the request message: + +- codes are extracted from the request message within TEE; +- the corresponding contract accounts are updated; +- the contract codes within TEE are encrypted, and then sent to a storage module to substitute the previous version. + +### **10.5 Receipt return** + +Finally, the receipt containing the result is encrypted within the TEE and returned to the relevant DLT user. + +## Appendix I + +### Example of key specification + +(This appendix does not form an integral part of this Recommendation.) + +The key specification defines the key information and related policies. The root key specification contains bit length, key policies, and nonce, where nonce is used to prevent replay attacks. The key policies contain backup policies, and synchronization policies. A root key specification example is illustrated in clause I.1. + +Different from the root key, the business key is used in each business, which is derived from the root key. The business key specification contains attributes. Type indicates the type of the business key to be generated, symmetric, asymmetric or certificate. Version indicates the max version of the business key. Key policies indicate how the key is used or delivered to the business in the whole lifecycle of the business key. + +### I.1 Root key specification example + +``` +{ + "rootKeySpec": { + "bitLength": 128, + "nonce": "KB003FRgkvrvq4pmQZ0x7lw==", + "policies": { + "backupPolicies": [ + { + "rootBackupPolicy": { + "numOfShares": 4, + "threshold": 3, + "clients": [ + "Admin01", + "Admin02", + "Admin03", + "Admin04" + ] + } + } + ], + "dkmsSyncPolicies": [ + { + "sgxPolicy": { + "measurement": { + "equivalentSigner": { + } + } + } + } + } + ] + } + }, + "clients": [ + { + "clientId": "Admin01", + "authentications": [ + { + "authType": "SINGLE_SIGNED", + "singleSigned": { + } + } + } + ] + } + ] +} +``` + +``` + +"pubkey":"0x2c0a6ef2d8bb9c0a25327a1989d2bfe345c262b12e1897fff2b1afc640691b7d36b3 +dc28ed109df7e5bf1a352f4a677896219e1fb235cad8461f5dd48c10fc6f" + } + } + ] +}, +{ + "clientId":"Admin02", + "authentications":[ + { + "authType":"SINGLE_SIGNED", + "singleSigned":{ + +"pubkey":"0x3e4d6673ba1dfb065bd9e4abd0cadd60aaa15bde4aada06b4c96a4448555befa74e +1c389942c3d3fb3318e92bfb4ec18fec62578ae3b81526dc3db90965eee9" + } + } + ] +}, +{ + "clientId":"Admin03", + "authentications":[ + { + "authType":"SINGLE_SIGNED", + "singleSigned":{ + +"pubkey":"0xf0869979404cd096bc3b48e9a844b385af31e9d94a0b1eff9d93bf411e449578c88b +07ce5b619f4ba67f514cb0d7cd3703277c58cad797936edc2bcdb0ffdbcd" + } + } + ] +}, +{ + "clientId":"Admin04", + "authentications":[ + { + "authType":"SINGLE_SIGNED", + "singleSigned":{ + +"pubkey":"0x6763a7eb2a6d9be5b77ac1efa188ca8f1331040039908019a3e12ac8ad924982cdb3 +283cf05fe58f8009b12f7d2e613b00ebd280b0871655296a341aa54039f4" + } + } + ] +} +] +} + +``` + +### A.2 Business key specification example + +``` + +{ + "bizKeySpecs":[ + { + "type":"SYMMETRIC", + "alias":"service_tee_symkey", + "symmetric":{ + "bitLength":128 + }, + "version":1, + "derivation":{ + "inputSecret":"root_key", + "x963Kdf":{ + "hashAlgorithm":"SHA256", + "salt":"saJpaIsN7yCVCNdsap7bEw==", + +``` + +``` + + "max_version":128 + } + }, + "policies":{ + "policy_group":"service_tee_policy" + } + }, + { + "type":"ASYMMETRIC", + "asymmetric":{ + "algorithm":"SECP256K1" + }, + "alias":"service_tee_asymkey_ec", + "version":0, + "derivation":{ + "inputSecret":"root_key", + "x963Kdf":{ + "hashAlgorithm":"SHA256", + "salt":"saJpaIsN7yCVCNdsap7bEw==", + "max_version":1024 + } + }, + "policies":{ + "policy_group":"service_tee_policy" + } + }, + { + "type":"SYMMETRIC", + "alias":"service_tee_symkey0", + "symmetric":{ + "bitLength":128 + }, + "version":1, + "derivation":{ + "inputSecret":"root_key", + "x963Kdf":{ + "hashAlgorithm":"SHA256", + "salt":"saJpaIsN7yCVCNdsap7bEw==", + "max_version":128 + } + }, + "policies":{ + "policy_group":"service_tee_policy" + } + } +], +"clients":[ + { + "clientId":"service_tee", + "authentications":[ + { + "authType":"SGX_MEASUREMENT", + "sgxMeasurement":{ + "signerIdentity":"83d719e77deaca1470f6baf62a4d774303c899db69020f9c70ee1dfc08c7ce9e", + "enclaveIdentity":"e490a8010981a5b817b1c26494705c7784e0aaf7eee47e03117df3b0f2dcf +f2a" + } + } + ] + }, + { + +``` + +``` + + "clientId":"Admin01", + "authentications":[ + { + "authType":"SINGLE_SIGNED", + "singleSigned":{ + +"pubkey":"0x2c0a6ef2d8bb9c0a25327a1989d2bfe345c262b12e1897fff2b1afc640691b7d36b3 +dc28ed109df7e5bf1a352f4a677896219e1fb235cad8461f5dd48c10fc6f" + } + } + ], + }, + { + "clientId":"Admin02", + "authentications":[ + { + "authType":"SINGLE_SIGNED", + "singleSigned":{ + +"pubkey":"0x3e4d6673baldfb065bd9e4abd0cadd60aaa15bde4aada06b4c96a4448555befa74e +1c389942c3d3fb3318e92bfb4ec18fec62578ae3b81526dc3db90965eee9" + } + } + ], + }, + { + "clientId":"Admin03", + "authentications":[ + { + "authType":"SINGLE_SIGNED", + "singleSigned":{ + +"pubkey":"0xf0869979404cd096bc3b48e9a844b385af31e9d94a0b1eff9d93bf411e449578c88b +07ce5b619f4ba67f514cb0d7cd3703277c58cad797936edc2bcdb0ffdbcd" + } + } + ], + }, + { + "clientId":"Admin04", + "authentications":[ + { + "authType":"SINGLE_SIGNED", + "singleSigned":{ + +"pubkey":"0x6763a7eb2a6d9be5b77ac1efa188ca8f1331040039908019a3e12ac8ad924982cdb3 +283cf05fe58f8009b12f7d2e613b00ebd280b0871655296a341aa54039f4" + } + } + ], + } + ], + "policy_group":{ + "name":"service_tee_policy", + "policies":{ + "clientSyncPolicies":[ + { + "sgxPolicy":{ + "measurement":{ + "specifiedSigner":{ + "client":"service_tee" + } + } + } + } + ] + } + } +} + +``` + +``` + } +], +"updatePolicies":[ + { + "signedMessagePolicy":{ + "multiSigned":{ + "threshold":3, + "clients":[ + "Admin01", + "Admin02", + "Admin03", + "Admin04" + ] + } + } + } +] +} +} +} +} +``` + +## Bibliography + +- [b-ITU-T F.751.0] Recommendation ITU-T F.751.0 (2020), *Requirements for distributed ledger systems*. +- [b-ITU-T F.751.1] Recommendation ITU-T F.751.1 (2020), *Assessment criteria for distributed ledger technology platforms*. +- [b-ITU-T F.751.6] Recommendation ITU-T F.751.6 (2020), *Performance assessment methods for distributed ledger technology platforms*. +- [b-ITU-T F.751.7] Recommendation ITU-T F.751.7 (2022), *Functional assessment methods for distributed ledger technology platforms*. +- [b-ITU-T X.1400] Recommendation ITU-T X.1400 (2020), Terms and definitions for distributed ledger technology. +- [b-ITU-T X.1401] Recommendation ITU-T X.1401 (2019), Security threats to distributed ledger technology. +- [b-ITU-T X.1402] Recommendation ITU-T X.1402 (2020), Security framework for distributed ledger technology. +- [b-ITU-T X.1404] Recommendation ITU-T X.1404 (2020), Security assurance for distributed ledger technology. +- [b-ISO 22739] ISO 22739:2020, *Blockchain and distributed ledger technologies – Vocabulary*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.760.1-202212-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg b/marked/F/T-REC-F.760.1-202212-I_PDF-E/390120de4fe440c42fea8154fcaad334_img.jpg new file mode 100644 index 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-0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:95d410e8445b790e622cff487fa9522a5d0830076b86e731816eacd978b8f03b +size 33034 diff --git a/marked/F/T-REC-F.760.1-202212-I_PDF-E/raw.md b/marked/F/T-REC-F.760.1-202212-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..dab81bb3ee79b52a83ab76efcbc11dc3622bc7f9 --- /dev/null +++ b/marked/F/T-REC-F.760.1-202212-I_PDF-E/raw.md @@ -0,0 +1,770 @@ + + +# Recommendation **ITU-T F.760.1 (12/2022)** + +SERIES F: Non-telephone telecommunication services +Multimedia services + +## --- **Requirements and reference framework for emergency rescue systems** + +![ITU logo](390120de4fe440c42fea8154fcaad334_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessages service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multdestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| MULTIMEDIA SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.760.1 + +## Requirements and reference framework for emergency rescue systems + +## Summary + +Recommendation ITU-T F.760.1 describes the application scenarios, functional requirements and reference architecture of pre-hospital emergency rescue and applies these to the planning and designing of emergency rescue systems in emergency centres, hospitals and other medical institutions. The appendix to this Recommendation includes some use cases of the proposed reference system. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.760.1 | 2022-12-14 | 16 | 11.1002/1000/15202 | + +## Keywords + +Emergency rescue system, reference framework, requirements, use case. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2023 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-------------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 2 | +| 3.1 Terms defined elsewhere ..... | 2 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 4 | +| 6 Background..... | 4 | +| 7 Requirements for emergency rescue systems ..... | 5 | +| 7.1 System functional requirements ..... | 5 | +| 7.2 Requirements for emergency rescue applications ..... | 5 | +| 7.3 Requirements for emergency rescue terminals..... | 7 | +| 7.4 Requirements for emergency rescue networks..... | 8 | +| 7.5 Requirements for emergency rescue cloud platform..... | 8 | +| 7.6 Requirements for patients with specific needs ..... | 9 | +| 7.7 Compatibility requirements ..... | 9 | +| 8 Reference framework for the emergency rescue system ..... | 10 | +| 8.1 Reference architecture of the overall system design ..... | 10 | +| 8.2 Reference architecture of the network layer..... | 11 | +| 8.3 Reference architecture of the cloud layer..... | 12 | +| Appendix I – Use cases..... | 15 | +| I.1 Introduction ..... | 15 | +| I.2 Smart first aid on the scene ..... | 15 | +| I.3 Emergency transportation..... | 16 | +| I.4 Remote emergency service dispatch management ..... | 17 | +| I.5 Emergency rescue equipment integration ..... | 18 | +| I.6 Emergency rescue for natural disasters and accident disasters ..... | 19 | +| I.7 Emergency rescue for public health emergencies ..... | 20 | +| Bibliography..... | 21 | + + + +# Recommendation ITU-T F.760.1 + +## Requirements and reference framework for emergency rescue systems + +# 1 Scope + +The Recommendation specifies the requirements and reference framework for emergency rescue systems. + +The scope of this Recommendation includes: + +- requirements for an emergency rescue system; +- reference framework for an emergency rescue system; +- use cases for an emergency rescue system. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T K.116] Recommendation ITU-T K.116 (2019), *Electromagnetic compatibility requirements and test methods for radio telecommunication terminal equipment*. +- [ITU-T M.3050.x] Recommendation ITU-T M.3050.x-series (2007), *Enhanced Telecom Operations Map (eTOM)*. +- [ITU-T Q.3741] Recommendation ITU-T Q.3741 (2019), *Signalling requirements for SD-WAN service*. +- [ITU-T Y.3500] Recommendation ITU-T Y.3500 (2014), *Information technology – Cloud computing – Overview and vocabulary*. +- [ITU-T Y.3502] Recommendation ITU-T Y.3502 (2014), *Information technology – Cloud computing – Reference architecture*. +- [ITU-R M.1787] Recommendation ITU-R M.1787-4 (2022), *Description of systems and networks in the radionavigation-satellite service (space-to-Earth and space-to-space) and technical characteristics of transmitting space stations operating in the bands 1 164-1 215 MHz, 1 215-1 300 MHz and 1 559-1 610 MHz*. +- [Bluetooth CS 5.3] Bluetooth CS 5.3 (2021), *Bluetooth Core Specification, v5.3*. +- [ETSI GS MEC 003] ETSI GS MEC 003 V3.1.1 (2022-03), *Multi-access Edge Computing (MEC): Framework and Reference Architecture*. +- [ETSI TS 123 501] ETSI TS 123 501 V17.6.0 (2022-09), *5G; System Architecture for the 5G System (5GS) (3GPP TS 23.501 version 17.6.0 Release 17)*. +- [ETSI TS 123 503] ETSI TS 123 503 V17.6.0 (2022-09), *5G; Policy and charging control framework for the 5G System (5GS); Stage 2 (3GPP TS 23.503 version 17.6.0 Release 17)*. + +- [ETSI TS 129 244] ETSI TS 129 244 V17.6.0 (2022-10), *LTE; 5G; Interface between the Control Plane and the User Plane nodes (3GPP TS 29.244 version 17.6.0 Release 17)*. +- [IEC 60601-1-2] IEC 60601-1-2 (2014), *Medical electrical equipment – Part 1-2: General requirements for basic safety and essential performance – Collateral Standard: Electromagnetic disturbances – Requirements and tests*. +- [IEC 60950-1] IEC 60950-1 (2013), *Information technology equipment – Safety – Part 1: General requirements*. +- [IEC 62680-2-1] IEC 62680-2-1 (2015), *Universal Serial Bus interfaces for data and power – Part 2-1: Universal Serial Bus Specification, Revision 2.0*. +- [IEC 62680-3-1] IEC 62680-3-1 (2017), *Universal Serial Bus interfaces for data and power – Part 3-1: Universal Serial Bus 3.1 Specification*. +- [IEEE 802.11] IEEE 802.11-2020, *IEEE Standard for Information Technology – Telecommunications and Information Exchange between Systems – Local and Metropolitan Area Networks – Specific Requirements – Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications*. +- [ISO 12052] ISO 12052 (2017), *Health informatics – Digital imaging and communication in medicine (DICOM) including workflow and data management*. +- [ISO/HL7 21731] ISO/HL7 21731 (2014), *Health informatics – HL7 version 3 – Reference information model – Release 4*. +- [ISO/IEC 7816-1] ISO/IEC 7816-1 (2011), *Identification cards – Integrated circuit cards – Part 1: Cards with contacts – Physical characteristics*. +- [ISO/IEC 14443-1] ISO/IEC 14443-1 (2018), *Cards and security devices for personal identification – Contactless proximity objects – Part 1: Physical characteristics*. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following term defined elsewhere: + +**3.1.1 service level agreement (SLA)** [ITU-T Y.3500]: Documented agreement between the service provider and customer that identifies services and service targets. + +NOTE 1 – A service level agreement can also be established between the service provider and a supplier, an internal group or a customer acting as a supplier. + +NOTE 2 – A service level agreement can be included in a contract or another type of documented agreement. + +### 3.2 Terms defined in this Recommendation + +None. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|----|-----------------------------------| +| 5G | 5th Generation of Mobile Networks | +| AF | Application Function | + +| | | +|----------|---------------------------------------------------| +| AI | Artificial Intelligence | +| APN | Access Point Name | +| AR | Augmented Reality | +| ATSSS | Access Traffic Steering, Switching and Splitting | +| BSS | Business Support Systems | +| COVID-19 | Corona Virus Disease 2019 | +| CPR | Cardiopulmonary Resuscitation | +| CSP | Communication Service Provider | +| DICOM | Digital Imaging and Communications in Medicine | +| DNN | Data Network Name | +| ECG | Electrocardiogram | +| eMBB | enhanced Mobile Broadband | +| EMC | essential Electromagnetic Compatibility | +| GIS | Geography Information System | +| GNSS | Global Navigation Satellite System | +| HDMI | High Definition Multimedia Interface | +| HL7 | Health Level Seven | +| ICU | Intensive Care Unit | +| IEEE | Institute of Electrical and Electronics Engineers | +| iGW | industry Gateway | +| iMEP | industry MEC Platform | +| IMT | International Mobile Telecommunications | +| IoT | Internet of Things | +| IPv4 | Internet Protocol Version 4 | +| IPv6 | Internet Protocol Version 6 | +| KPI | Key Performance Indicator | +| LAN | Local Area Network | +| MEC | Multi-access Edge Computing | +| MEO | Mobile Edge Orchestrator | +| MEP | MEC Platform | +| MEPM | MEC Platform Manager | +| MPDS | Medical Priority Dispatch System | +| NAPT | Network Address Port Translation | +| NAT | Network Address Translation | +| NLP | Natural Language Processing | +| OSS | Operation Support Systems | +| PCI-E | Peripheral Component Interconnect Express | + +| | | +|--------|-------------------------------------------| +| PGW-U | PDN Gateway User plane function | +| QoS | Quality of Service | +| RAN | Radio Access Network | +| RNSS | Radio Navigation Satellite System | +| SD-WAN | Software-Defined Wide Area Networking | +| SGW-U | Serving Gateway User plane function | +| SLA | Service Level Agreement | +| SMS | Short Message Service | +| UPF | User Plane Function | +| uRLLC | ultra-Reliable Low Latency Communications | +| URSP | UE Route Selection Policy | +| VGA | Video Graphics Array | +| VPN | Virtual Private Network | +| VR | Virtual Reality | +| Wi-Fi | Wireless Fidelity | + +# 5 Conventions + +In this Recommendation: + +The keywords "**is required to**" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed. + +The keywords "**is recommended**" and "**should**" indicate a requirement which is recommended but which is not absolutely required. Thus this requirement needs not be present to claim conformance. + +The keywords "**can optionally**" and "**may**" indicate an optional requirement which is permissible, without implying any sense of being recommended. These terms are not intended to imply that the vendor's implementation must provide the option and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the specification. + +# 6 Background + +As advanced technologies such as 5G/IMT-2020, cloud computing, big data, artificial intelligence, and IoT accelerate, emergency rescue services have the potential to further save precious rescue time and save more lives. Especially with the continuous evolution of mobile communication technology, many emergency rescue services that rely on the characteristics of communication technology can be supported. 5G/IMT-2020 technology can eliminate the network delay within 10 ms, making it possible to remotely control drones and other equipment for emergency material distribution, emergency observation on the scene. 5G/IMT-2020 technology will allow emergency services to use Internet of Things (IoT) devices. For instance, emergency services can use it for sensor networks to help remotely monitor critically ill patients and epidemic control. + +At present, there are already some successful cases of combining 5G/IMT-2020 technology and emergency rescue services around the world. However, there are still many problems in the existing emergency rescue system. The emergency rescue resources of multilevel medical institutions have not been effectively integrated, and there is a lack of generalized platform requirements, and standardized and shared intelligent emergency rescue service systems. The application of advanced + +technologies such as 5G/IMT-2020, cloud computing, big data, Internet of Things, artificial intelligence, etc. is still being explored and only applied in a limited range. The emergency rescue system is not systematic and intelligent enough. It is also necessary to study what use cases can effectively combine cutting-edge technologies with the emergency rescue system. Most of the current emergency rescue service scenarios empowered by 5G/IMT-2020 remain on the transmission of ultra-high-definition data based on eMBB. interoperability emergency services scenarios based on uRLLC need to be further studied, such as how to carry out remote surgery in emergency rescue scenarios. + +Researching how advanced technologies enable an emergency rescue system can gradually realize the goal of patients getting effective treatment as soon as the onset of the illness arises, and patients can get equivalent intra-hospital medical services on the ambulance. It can further optimize the emergency service procedure and realize the smooth flow of information in the procedure, increase the utilization rate of medical resources, and comprehensively guarantee the efficient development of all emergency rescue services. + +# **7 Requirements for emergency rescue systems** + +### **7.1 System functional requirements** + +This clause will provide a detailed description of the requirements of emergency rescue systems. + +- a) Multiple category medical devices should be connected via a cellular network and other communication technologies, including 2G, Wi-Fi [IEEE 802.11], Bluetooth [Bluetooth CS 5.3], etc. But it is optional for IMT-2000, IMT-Advanced, 5G/IMT-2020 networks since their deployment is not available everywhere. +- b) Emergency rescue dedicated networks should be supported, providing private communication resources for guaranteed SLA performance under high-speed mobility scenarios and security by separating medical data from public communications. +- c) Cloud-network management convergence should be supported, providing unified management on different access networks, emergency rescue applications and services management, computing resources virtualization, etc. +- d) It should support various services and applications under different emergency rescue scenarios, which provide functionalities that include patient information synchronization, remote medical consultation and emergency resources scheduling (e.g., ambulance, doctors, etc.). + +### **7.2 Requirements for emergency rescue applications** + +The requirements of emergency rescue applications are listed as follows: + +- a) They should support the scenario that the patient can make an alarm call in an emergency, and also support the scenario that the patient cannot make an alarm call, such as a sudden heart attack, where the patient cannot speak and there is no cellular network coverage. +- b) They should support interactive text, voice, image and video data between emergency rescue terminals and servers, such as HL7 [ISO/HL7 21731] messages and DICOM [ISO 12052] images. +- c) They should support medical information systems, including structured medical record information, vital sign data, prognosis data, medical knowledge graphs, etc. +- d) They should support emergency dispatching functions, which carry out the overall dispatching of medical resources, such as the medical priority dispatch system (MPDS). +- e) They should support real-time monitoring services of patients inside the ambulance, which include the performance requirements [3GPP TR 22.826] in Table 7-1. + +- f) They should support smart triage systems and early alert systems on the ambulance to facilitate in-hospital preparation in advance. +- g) They can optionally support remote intervention for patients inside the ambulance, which includes the performance requirements [b-3GPP TR 22.826] in Table 7-2. +- h) They can optionally support the location and tracking of patients and ambulances through cellular base station positioning or radio navigation satellite system (RNSS) positioning [ITU-R M.1787]. +- i) They can optionally support real-time tracking of the ambulances through the SMS message received from the emergency command centre. +- j) They can optionally support a wireless emergency intercom system in non-regular scenarios so that medical staff can carry a lightweight two-way radio or use a base station intercom. +- k) They can optionally support various emergency rescue applications based on AI technologies, including computer-aided diagnosis systems such as medical image recognition, medical information extraction and content structuring, voice recognition and transcription technology, etc. + +**Table 7-1 – Performance requirements of patient monitoring inside the ambulance** + +| Types | Communication service availability: target value in % | End-to-end latency: maximum (ms) | Bit rate | Direction | +|-------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------|-----------------------------------------|-----------------|-------------------------------------------| +| Compressed 4K
(3 840 × 2 160 pixels)
12 bits per pixel
(e.g., YUV4:1:1) 60 fps
real time video stream | 99.99 | < 100 | 25 Mbits/s | UE towards network | +| Uncompressed
2 048 × 2 048 pixels
16 bits per pixel 10 fps
real-time video scan stream | 99.999 | < 100 | 670 Mbits/s | UE towards network | +| Physical vital signs
monitoring data stream | 99.999 | < 100 | 1 Mbits/s | UE towards network | +| High-quality audio
stream | 99.99 | < 100 | 128 kbits/s | UE towards network;
network towards UE | + +**Table 7-2 – Performance requirements of intervention for patients inside the ambulance** + +| Types | Communication service availability: target value in % | End-to-end latency: maximum (ms) | Bit rate (Mbits/s) | Direction | +|-----------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------|-----------------------------------------|---------------------------|--------------------| +| Compressed 4K
(3 840 × 2 160 pixels)
60 fps 12 bits per pixel
color coded (e.g., YUV
4:1:1) real-time video
stream | 99.99 | < 20 | 25 | UE towards network | + +**Table 7-2 – Performance requirements of intervention for patients inside the ambulance** + +| Types | Communication service availability: target value in % | End-to-end latency: maximum (ms) | Bit rate (Mbits/s) | Direction | +|-------------------------------------------------------------------------------------------|--------------------------------------------------------------|-----------------------------------------|---------------------------|--------------------| +| Uncompressed
512 × 512 pixels 32 bits
20 fps video stream
from ultra-sound probe | 99.999 | < 20 | 160 | UE towards network | + +### **7.3 Requirements for emergency rescue terminals** + +An emergency rescue terminal is used for information collection and transmission, two types of emergency rescue terminals are referred to in the system, the emergency cellular terminals and access gateway. For emergency cellular terminals, which can access the cellular networks directly, and for the access gateway, which can support those traditional medical devices access to the wireless network, convert a non-3GPP network (Wi-Fi, optical fibre, Bluetooth, etc.) to a cellular network. + +#### **7.3.1 General requirements** + +Emergency rescue terminals are required to meet the following requirements, both for the emergency cellular terminals and access gateway equipment. The general requirements towards terminals are listed as follows: + +- They should support at least 2G and be optional for IMT-2000, IMT-Advanced, 5G/IMT-2020. +- They should support APN configuration under IMT-Advanced networks and also support DNN configuration if a 5G/IMT-2020 network is available. +- They should support network slicing, URSP [ETSI TS 123 503], and ATSSS [ETSI TS 123 501] if a 5G/IMT-2020 network is available. +- They should support equipped with RNSS [ITU-R M.1787] receivers. +- They should support electrical safety standards [IEC 60950-1]. +- They should support the basic safety and essential performance of medical electrical equipment [IEC 60601-1-2]. +- They should support EMC requirements for radiocommunication terminal equipment and ancillary accessories [ITU-T K.116]. +- They can optionally have a contact card reader [ISO/IEC 7816-1] and contactless card reader [ISO/IEC 14443-1]. + +#### **7.3.2 Access gateway requirements** + +Specific requirements for the access gateway are as follows: + +- It should support IPv4 and IPv6 dual-stack protocols. +- It should support NAT and NAPT functions. +- It should support the SLA guarantee for those non-3GPP network connections to the access gateway. +- It should support at least USB2.0 [IEC 62680-2-1] and be optional for USB3.x [IEC 62680-3-1], VGA, HDMI, PCI-E, Ethernet interface. +- It can optionally support the fan-less cooling design and work at –30 to 70 degrees Celsius for the operating temperature. + +- f) It can optionally support a backup battery for power supply. +- g) It can optionally support a built-in offline storage function and retransmit data when network connectivity is restored. + +### 7.4 Requirements for emergency rescue networks + +The requirements of emergency rescue networks are as follows. + +- a) They should support continuous cellular network coverage in urban and rural scenarios. +- b) They should support temporary cellular network coverage in non-regular scenarios, including sea, desert, virgin forest, earthquakes, etc. Here, multiple types of backhaul modules (drones, satellite communications, relay, etc.) should be provided for network connection establishment, and they also can optionally support lightweight and portable wireless base stations which can be powered by batteries and connected to backhaul modules. +- c) They should support providing dedicated physical or virtualized network resources for SLA guarantee and data security, and the performance requirements are listed in Table 7-3. +- d) They should support the emergency rescue terminal to access the cellular network through a non-3GPP network. +- e) They should support IoT, which includes the performance requirements [b-3GPP TR 22.826] in Table 7-4. +- f) They should support unified management and access authority management over different networks, including cellular networks, Wi-Fi, IoT, Bluetooth, etc. +- g) They should provide APIs for a hospital's self-management on the aforementioned networks in points a) and b) of clause 7.4. +- h) They should provide different network exposure to medical applications, including positioning and QoS, etc., and also network slicing if a 5G/IMT-2020 network is available. + +**Table 7-3 – Performance requirements of dedicated network** + +| Bandwidth | Latency | Jitter | Packet loss rate | +|--------------|---------|---------|------------------| +| > 100 Mbit/s | < 50 ms | < 20 ms | < $10^{-3}$ | + +**Table 7-4 – Performance requirements of IoT** + +| Communication service availability: target value | End-to-end latency: maximum | Service bit rate: user experienced data rate | +|--------------------------------------------------|-----------------------------|----------------------------------------------| +| 99.9999 % | < 100 ms | 0.5 Mbit/s | + +### 7.5 Requirements for emergency rescue cloud platform + +The requirements of the emergency rescue cloud platform are as follows: + +- a) It should support cloud computing management [ITU-T Y.3500], [ITU-T Y.3502], which provides the essential requirement for virtualization infrastructure, including compute, storage and network resources. +- b) It should support MEC [ETSI GS MEC 003] functions and local management if a 5G/IMT-2020 network is available, which can enable mobile edge applications to run efficiently and seamlessly in a cellular network. +- c) It should support the hospital's self-management on an emergency rescue network based on the APIs provided by the network, including unified network management over different + +network types, network slicing management, location management, and QoS management, access authority management, etc. + +- d) It should support onboard emergency application management, including application lifecycle management and package management, etc. +- e) It should support emergency rescue-specific cloud capabilities, including high-reliability and high-definition video services, AI functions (data preprocessing, model training, model evaluation, and model prediction), big data compute functions (batch and streaming data processing), and object storage functions (database and file storage), etc. +- f) It should support situational awareness capabilities to accurately perceive and actively acquire emergency events, including measurements of network quality (e.g., network packet loss, latency and jitter), cloud resources, applications, securities, etc. +- g) It should support the management and maintenance functions of terminals mentioned in clause 7.3, such as terminal upgrade, software installation, work log reading and analysis. + +### 7.6 Requirements for patients with specific needs + +This clause provides a detailed description of the requirements for patients with specific needs (e.g., hearing and speech impairment, heavy dialect, unclear description of the condition due to emotional tension, etc.). They cannot raise the alarm in the usual manner. There should be support for some functions for those patients with specific requirements, as shown below. + +- a) **Disease condition function:** Personal information such as mobile phone number, residential address, emergency contact person, and medical conditions will be filled in advance. +- b) **Positioning function:** The precise position of the patient can be located in real time. +- c) **One-touch alarm function:** The condition of a patient's disease and positioning information will be sent to the emergency command centre with one click. +- d) **NLP function:** The patient can keep in touch with the emergency command centre and receive self-rescue guidance. + +There should be support for some functions for the emergency command centre, as shown below. + +- a) **SMS confirmation function:** This module interacts with the aforementioned one-touch alarm module so that the emergency command centre can promptly inform the patient that the alarm information has been received and a nearby ambulance has been dispatched. +- b) **Self-rescue guidance function:** This module interacts with the aforementioned NLP module so that the emergency command centre can give preliminary self-rescue measures through proactive digital guidance (e.g., text, images, voice, etc.). + +![Diagram illustrating the requirements of patients with specific needs. The diagram shows two main components: 'Patient with specific needs' and 'Emergency command centre'. The 'Patient with specific needs' component contains four boxes: 'Disease condition', 'Positioning', 'One-touch alarm', and 'NLP'. The 'Disease condition' and 'Positioning' boxes point to the 'One-touch alarm' box. The 'One-touch alarm' box points to the 'Emergency command centre' component. The 'Emergency command centre' component contains two boxes: 'SMS confirmation' and 'Self-rescue guidance'. The 'SMS confirmation' box points to the 'One-touch alarm' box. The 'Self-rescue guidance' box points to the 'NLP' box. The 'NLP' box points to the 'Self-rescue guidance' box.](bffdddb47fced140f8d17fdc2a29f592_img.jpg) + +``` +graph LR; subgraph Patient_with_specific_needs [Patient with specific needs]; DC[Disease condition] --> OTA[One-touch alarm]; P[Positioning] --> OTA; OTA --> ECC[Emergency command centre]; NLP[NLP] --> SRG[Self-rescue guidance]; end; subgraph Emergency_command_centre [Emergency command centre]; SC[SMS confirmation] --> OTA; SRG --> NLP; end; +``` + +Diagram illustrating the requirements of patients with specific needs. The diagram shows two main components: 'Patient with specific needs' and 'Emergency command centre'. The 'Patient with specific needs' component contains four boxes: 'Disease condition', 'Positioning', 'One-touch alarm', and 'NLP'. The 'Disease condition' and 'Positioning' boxes point to the 'One-touch alarm' box. The 'One-touch alarm' box points to the 'Emergency command centre' component. The 'Emergency command centre' component contains two boxes: 'SMS confirmation' and 'Self-rescue guidance'. The 'SMS confirmation' box points to the 'One-touch alarm' box. The 'Self-rescue guidance' box points to the 'NLP' box. The 'NLP' box points to the 'Self-rescue guidance' box. + +Figure 7-1 – Requirements of patients with specific needs + +### 7.7 Compatibility requirements + +There should be support for emergency rescue applications to run seamlessly on different cloud platforms. + +# 8 Reference framework for the emergency rescue system + +### 8.1 Reference architecture of the overall system design + +Figure 8-1 illustrates the proposed overall emergency rescue system design. Four layers are defined here, including terminal, network, cloud and application layers. Moreover, to make the heterogeneous emergency rescue system manageable, flexible and suitable for various emergency applications, the cloud layer can orchestrate and manage the other three layers. + +- a) The terminal layer is used for information collection as the carrier of medical tools and applications and also for information transmission. It can be classified into integrated terminals, information collection and display terminals and auxiliary terminals. The integrated terminals are taken as a 5G/IMT-2020 access gateway, which connects multiple medical terminals and transfers the data to a 5G/IMT-2020 signal. The information collection and display terminals are used to gather and display emergency data; these are represented as wearable equipment, first aid kits, smart boxes, video terminals, imaging equipment, etc. The auxiliary terminals are used to improve the flexibility and efficiency of emergency rescue, including ambulances, robots, drones, etc. +- b) The network layer plays a crucial role in emergency data transmission, providing SLA guaranteed, data isolated, global-area mobility and a private link between the terminal layer and the cloud layer. To support different scenarios, including for a smart first aid on the scene, emergency transportation, etc. Here different network topologies and KPIs should be provided to satisfy various requirements. The dedicated communication link can be carried as 5G/IMT-2020 network slicing, 5G/IMT-2020 LAN [ETSI TS 123 501], IoT, and dedicated lines (etc., VPN, fibre line). +- c) The cloud layer cooperating with the network layer for the emergency data breakout from the dedicated network, also provides the virtualization infrastructure, including compute, storage and network resources, to run emergency-specific applications. Moreover, it provides emergency-specific services, including AI, big data, video, object storage, network ability (positioning, QoS management, etc.), as well as supporting various emergency-specific applications. The cloud layer could be implemented based on 5G/IMT-2020 MEC [ETSI GS MEC 003], private cloud, or other security-guaranteed public cloud, etc. +- d) To support different emergency services and scenarios, various applications should be provided in the application layer, such as a high-definition audio and video interactive system, remote emergency consultation system, emergency auxiliary support system, positioning and search and rescue system (including GNSS and GIS system), emergency command system, big data analysis system, situational awareness system and emergency medical information system. + +![Figure 8-1: Reference architecture of the overall system design. The diagram shows four layers: Application layer, Cloud layer, Network layer, and Terminal layer. The Application layer contains eight systems: High-definition audio and video interactive system, Remote emergency consultation system, Emergency auxiliary support system, Positioning and search and rescue system, Emergency command system, Big data analysis system, Situational awareness system, and Emergency medical information system. The Cloud layer contains five components: AI, Big data, Video, Object storage, and Network ability. The Network layer contains four options: 5G network slicing, 5G LAN, IoT, and Dedicated line. The Terminal layer is divided into three categories: Integrated terminal (5G access gateway), Information collection and display terminal (Wearable device, First aid kit, Smart box, Video terminal, Imaging equipment), and Auxiliary terminal (Ambulance, Robot, Drone).](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg) + +| | | | | | | | | | | +|--------------------------|----------------------------------------------------|----------------------------------------------------|------------------------------------|------------------------------------------|-----------------|-------------------|---------------------------|-------|-------| +| Application layer | High-definition audio and video interactive system | Remote emergency consultation system | Emergency auxiliary support system | Positioning and search and rescue system | | | | | | +| | Emergency command system | Big data analysis system | Situational awareness system | Emergency medical information system | | | | | | +| Cloud layer | AI | Big data | Video | Object storage | Network ability | | | | | +| Network layer | 5G network slicing | 5G LAN | IoT | Dedicated line | | | | | | +| Terminal layer | 5G access gateway | Wearable device | First aid kit | Smart box | Video terminal | Imaging equipment | Ambulance | Robot | Drone | +| | Integrated terminal | Information collection and display terminal | | | | | Auxiliary terminal | | | + +Figure 8-1: Reference architecture of the overall system design. The diagram shows four layers: Application layer, Cloud layer, Network layer, and Terminal layer. The Application layer contains eight systems: High-definition audio and video interactive system, Remote emergency consultation system, Emergency auxiliary support system, Positioning and search and rescue system, Emergency command system, Big data analysis system, Situational awareness system, and Emergency medical information system. The Cloud layer contains five components: AI, Big data, Video, Object storage, and Network ability. The Network layer contains four options: 5G network slicing, 5G LAN, IoT, and Dedicated line. The Terminal layer is divided into three categories: Integrated terminal (5G access gateway), Information collection and display terminal (Wearable device, First aid kit, Smart box, Video terminal, Imaging equipment), and Auxiliary terminal (Ambulance, Robot, Drone). + +F.760.1(22) + +**Figure 8-1 – Reference architecture of the overall system design** + +### 8.2 Reference architecture of the network layer + +Under a typical emergency scenario, various facilities are required, such as ambulances, emergency command centres and hospitals. The network layer is used to build a connection between the aforementioned facilities and support a wide-connected, low-latency and highly-reliable data transmission path under emergency rescue scenarios. Here, the emergency control link and emergency data link shall be included, as shown below. + +- Emergency control link is used for the ambulance and hospital scheduling, and the transmitted information includes the patient location, illness, electronic medical record, etc. +- After the control link is created, a dedicated data link is established between the hospital and the ambulance for transmitting emergency data. In general, the ambulance is equipped with networking access, such as a 5G/IMT-2020 connection. +- The control link and data link could be 5G/IMT-2020 LAN, 5G/IMT-2020 network slicing, and the control link can also use the dedicated line (VPN, fibre line, etc.) for information transmission. + +To make these defined communication links available, the emergency rescue network's infrastructure should include access network, transport network and local data breakout. The local data breakouts are performed as UPF [ETSI TS 123 501] in 5G/IMT-2020 systems and PGW-U/SGW-U [ETSI TS 129 244] in IMT-Advanced systems. Benefiting from network slicing, multiple virtualized and independent logical emergency networks can be created simultaneously on the same physical network infrastructure. Each logical emergency network is an isolated end-to-end network tailored to fulfil diverse requirements requested by a particular emergency application. + +![Figure 8-2: Reference network architecture of the network layer. The diagram shows an Emergency command centre connected to a Hospital and an Ambulance. The Emergency command centre has a dashed double-headed arrow labeled 'Control link' connecting it to the Hospital. The Hospital has a dashed double-headed arrow labeled 'Data link' connecting it to the Ambulance. The label F.760.1(22) is at the bottom right.](76b0cd79baaedd942af4dc42f2e764b8_img.jpg) + +Figure 8-2: Reference network architecture of the network layer. The diagram shows an Emergency command centre connected to a Hospital and an Ambulance. The Emergency command centre has a dashed double-headed arrow labeled 'Control link' connecting it to the Hospital. The Hospital has a dashed double-headed arrow labeled 'Data link' connecting it to the Ambulance. The label F.760.1(22) is at the bottom right. + +**Figure 8-2 – Reference network architecture of the network layer** + +### 8.3 Reference architecture of the cloud layer + +Concerning the 5G/IMT-2020 architecture definition in 3GPP, the MEC is fully integrated with the 5G/IMT-2020 network through the UPF and AF to play a good effect in the emergency scenarios, such as lower end-to-end latency, lighter load on backhaul link, less energy consumption for battery-operated devices, smaller network bandwidth and more secure data transmission. In addition to these key network elements, the BSS/OSS [ITU-T M.3050] is essential for the telecommunication service provider; functionalities such as billing, service management, assurance, element management, provisioning and network management are provided for network operation. + +One emergency-specific MEC architecture is proposed here, as illustrated in Figure 8-3. A new network element named iGW is introduced between the UPF and MEP, and it is managed by a dedicated orchestrator system. The iGW will play a crucial role in network management, wide-area connection, user access control, and the network capabilities exposure. Meanwhile, the dedicated MEP, named iMEP here, had also been enhanced to coordinate with iGW to make these iGW's features feasible in emergency applications. The emergency-specific MEC consists of iGW and iMEP, which provide universal networks and computational resources and emergency rescue applications for end users. + +![Figure 8-3: Reference architecture of emergency-specific MEC. The diagram shows the 5G/IMT-2020 core network connected to BSS/OSS and UPF. BSS/OSS is connected to iGW #2 via I3. UPF is connected to iGW #1 via N6. iGW #1 is connected to iGW #2 via I5. iGW #1 is connected to iMEP #1 via I4. iGW #2 is connected to iMEP #2 via I4. iGW #1 is connected to Third-party network via I1. iGW #1 is connected to Third-party network capacities via I2. The label F.760.1(22) is at the bottom right.](9cd90f495b95ad2116ff780248c26d95_img.jpg) + +Figure 8-3: Reference architecture of emergency-specific MEC. The diagram shows the 5G/IMT-2020 core network connected to BSS/OSS and UPF. BSS/OSS is connected to iGW #2 via I3. UPF is connected to iGW #1 via N6. iGW #1 is connected to iGW #2 via I5. iGW #1 is connected to iMEP #1 via I4. iGW #2 is connected to iMEP #2 via I4. iGW #1 is connected to Third-party network via I1. iGW #1 is connected to Third-party network capacities via I2. The label F.760.1(22) is at the bottom right. + +**Figure 8-3 – Reference architecture of emergency-specific MEC** + +#### 8.3.1 Network gateway functionalities + +The iGW is the essential network element to achieve cloud-network integration. It's a manageable, controllable and perceptible integrated network service portal created exclusively for emergency rescue customers, responsible for all network-related processing and controlled by a CSP. It opens the supported five functionalities to applications with friendly APIs at the iGW, whose functions are described as follows. + +- Hospital multi-standard network unified access management capabilities.** These support the unified access management of the hospital's multi-standard network, including 3GPP network, non-3GPP network (e.g., Wi-Fi, Bluetooth, etc.), network capabilities (e.g., position, QoS, network slicing, etc.), and emergency dedicated network access services. + +- b) **The wide-area interconnection between hospitals.** The wide-area mesh network is created by multiple iGWs, which can support SLA-guaranteed, confidential communications between hospitals to allow emergency business collaboration for those hospitals in different regions. +- c) **Unified access and exposure of multiple types of network capabilities.** The iGW will be taken as an agent for 5G/IMT-2020 core network, RAN and other networks (e.g., Wi-Fi, Bluetooth, etc.), and exposing the different types of network capacities to iMEPs. +- d) **Access authority management:** This provides user access authority management and service access authority management. +- e) **Self-service resource management:** This realizes network partition authority management, performance management, routing strategy, network slicing template, etc. Based on standard APIs provided by the iGW, the user can use these network functionalities (position, QoS, network slicing, etc.) for fast emergency applications creation, self-service network management and operation on the 5G/IMT-2020 network. + +#### 8.3.2 Reference architecture of dedicated MEP + +The MEP's resource assignment, applications boarding, and lifecycle are managed by the MEO and MEPM [ETSI GS MEC 003]. For data transmission security, the hospital manages the iMEP and authorizes all exchanged signalling and data between MEP and MEPM or MEO. Furthermore, the iMEP is an application empowerment platform built for emergency services. The more complex functions of iMEPs are divided into four functional layers, as described below. + +- a) A unified platform management layer provides application management, service management, resource management, configuration management, alarm monitoring and system management. +- b) The platform capability opening layer provides unified protocol and conversion, flow restriction, authentication, routing forwarding, rule verification, statistics, etc. +- c) The platform capability access layer provides a unified capability access framework for the emergency rescue applications. +- d) The infrastructure layer provides compute, storage, network and security resources. + +#### 8.3.3 Reference architecture of dedicated cloud integrating with network + +The aforementioned iGW needs to interact with many network devices or elements to realize those functions (e.g., multi-standard network unified access management capabilities, wide-area interconnection between hospitals, unified access and exposure of multiple types of network capabilities, etc.) agreed upon by the iGW. The newly increased interfaces I1~I5 are shown in Figure 8-3. + +- a) **I1 interface.** This is mainly used for access authentication, network control and data transmission of third-party networks. It can also transmit data between iGW and third-party networks through dedicated tunnels. +- b) **I2 interface.** This is mainly used to access and control network capabilities acquisition and provide third-party network capability lists (bandwidth, bandwidth control granularity, position, QoS, number of access users, etc.) to the MEC platform based on standard APIs. +- c) **I3 interface.** This is mainly used for the iGW's policy configuration and operation status monitoring, including the iGW registration, operation authority, method and range for network capabilities exposure, status monitoring, etc. + +- d) **I4 interface.** This is mainly used to realize network partition authority management, performance management, routing strategy, network slicing template, etc. Based on standard APIs provided by the iGW, the user can use those network functionalities (positioning, QoS, network slicing, etc.) for fast emergency applications creation, self-service network management, and operation on the 5G/IMT-2020 network. +- e) **I5 interface.** This realizes wide-area interconnection between iGWs, allowing interconnection between hospitals anytime and anywhere. The wide-area interconnection can be implemented by SD-WAN [ITU-T Q.3741] or 5G/IMT-2020 LAN. + +# Appendix I + +## Use cases + +(This appendix does not form an integral part of this Recommendation.) + +This clause describes various scenarios for emergency rescue systems. + +## I.1 Introduction + +Use cases generated as part of this Recommendation are categorized as follows: + +Use cases covering the emergency treatment of general scenarios for individuals: These use cases are captured in the "Smart first aid on the scene", "Emergency transportation", "Remote emergency service dispatch management", and "Emergency rescue equipment integration" clauses of this Recommendation. + +Use cases covering the emergency treatment of public safety incidents for the community or society: These use cases are captured in the "Emergency rescue for natural disasters and accident disasters" and "Emergency rescue for public health emergencies" sections of this document. + +## I.2 Smart first aid on the scene + +### I.2.1 Description + +The typical methods of on-site first aid include extra-cardiac defibrillation, CPR and basic techniques such as haemostasis, bandaging, fixation and transportation. Smart first aid can maintain and rescue the wounded and sick's lives, alleviate their suffering and prevent complications and sequelae as much as possible. + +#### I.2.2 Pre-conditions + +A person has suddenly fainted on the road and the entourage called the police. The medical staff arrive at the scene in an ambulance. Each piece of required equipment (5G/IMT-2020 remote B-ultrasound, remote ECG monitoring equipment, IoT bracelet, etc.) is: + +- powered up, and +- the emergency control link and data link have been established. + +#### I.2.3 Service flows + +- 1) When the medical staff arrive at the scene, they immediately perform a physical examination of the patient, check the patient's vital signs and obtain vital signs data such as heart rate, pulse, blood pressure, blood sugar and ultrasound images. +- 2) The medical staff judge whether the patient's vital signs are stable and whether external defibrillation and CPR is needed. +- 3) 5G/IMT-2020 network slicing will transmit all medical data to the emergency room in the hospital. +- 4) Suppose the level and experience of the medical staff on board are insufficient. The medical staff transmits the first aid treatment situation in real time through portable high-definition cameras and AR glasses. The emergency doctors in the hospital can communicate with the on-site medical staff in real time and guide the medical staff to check and rescue. + +#### I.2.4 Post-conditions + +The medical staff have delivered emergency treatment and detailed examinations on the patient, collected the patient's vital signs data and initially controlled the condition. The patient is then transferred to an ambulance. + +### **I.3 Emergency transportation** + +#### **I.3.1 Description** + +Emergency transportation generally refers to pre-hospital emergency transportation. It focuses on rescuing patients who are wounded in an accident. The service mainly includes emergency transport of injured and critically ill patients, and medical services' logistical support for major events. The ambulance is equipped with IoT bracelets, high-definition imaging equipment, remote ECG monitoring devices, medical AR glasses and other equipment. The patient's various data information will be immediately transmitted to the rescue centre of the hospital through the 5G/IMT-2020 network slicing, and the doctor can check the patient's physical signs data in advance. During the emergency transportation, doctors in the hospital can also remotely guide the paramedics in the ambulance to complete the pre-operation preparations for the patient, achieving the practices for the operation in the hospital in advance. + +#### **I.3.2 Pre-conditions** + +A person suddenly fainted on the road and the entourage called the police. The medical staff arrive at the scene in an ambulance. Each piece of required equipment (5G/IMT-2020 remote B-ultrasound, remote ECG monitoring equipment, IoT bracelet, etc.) is: + +- powered up, and +- the emergency control link and data link have been established. + +#### **I.3.3 Service flows** + +- 1) The medical staff send the patient to the ambulance, give the patient immediate emergency treatment such as oxygen inhalation, CPR, open venous access under the standard operating procedures. +- 2) On the way to the hospital the medical staff confirm the identity of the patient. + - Suppose the patient is conscious, they can provide basic personal information. + - Suppose the patient is no longer able to cooperate with the examination. The medical staff can connect an extensive database to determine the patient's identity quickly through intelligent devices such as facial recognition. +- 3) On the way to the hospital, the emergency doctors of the hospital make maximum use of the transportation time to prepare for the operation. + - Suppose the patient has mild symptoms. The medical staff connect to the patient's electronic medical record system through a 5G/IMT-2020 network, which transmits the patient's past medical history, medical records and primary diseases to the emergency medical information system. Medical staff in pre-hospital emergency and in-hospital emergency can simultaneously obtain relevant information. + - Suppose the patient is severely ill. The hospital's emergency experts observe the patient's condition in real time through the 5G/IMT-2020 network slicing, guide the onboard medical staff, and do the essential vital signs detection and basic medical examination before admission. + +#### **I.3.4 Post-conditions** + +When the ambulance arrived at the hospital, the hospital's medical staff had already prepared for the operation. If the patient is in a critical condition, the hospital will immediately open a green channel. + +### I.4 Remote emergency service dispatch management + +#### I.4.1 Description + +Remote emergency service dispatch management is to dispatch medical resources in a particular area. It gathers all emergency information within a specific range and effectively coordinates an ambulance, ICU, operating room and other related parties during the emergency rescue process. After receiving the alarm call there are two scenarios: + +- **Scenario 1:** There is no ambulance in the emergency centre, and the selected hospital sends an ambulance. +- **Scenario 2:** The emergency centre owns many ambulances and dispatches an ambulance. + +![Diagram of Scenario 1: Ambulance dispatch from hospital. The diagram shows four main entities: Hospital (top left), Emergency command centre (top right), Ambulance (bottom left), and a person receiving first aid (bottom center). Arrows indicate the flow of information and resources: 1. Alarm call from the person to the Emergency command centre. 2. Notify the hospital from the Emergency command centre. 3. Dispatch an ambulance from the Hospital to the Ambulance. 4. First aid on the scene from the person to the Ambulance. 5. Emergency transportation from the Ambulance to the Hospital. A legend on the right lists these five steps. The code F.760.1(22) is at the bottom right.](844077b3034f0030b404207db0ad76b4_img.jpg) + +Emergency command centre + +Hospital + +1. Alarm call +2. Notify the hospital +3. Dispatch an ambulance +4. First aid on the scene +5. Emergency transportation + +F.760.1(22) + +Diagram of Scenario 1: Ambulance dispatch from hospital. The diagram shows four main entities: Hospital (top left), Emergency command centre (top right), Ambulance (bottom left), and a person receiving first aid (bottom center). Arrows indicate the flow of information and resources: 1. Alarm call from the person to the Emergency command centre. 2. Notify the hospital from the Emergency command centre. 3. Dispatch an ambulance from the Hospital to the Ambulance. 4. First aid on the scene from the person to the Ambulance. 5. Emergency transportation from the Ambulance to the Hospital. A legend on the right lists these five steps. The code F.760.1(22) is at the bottom right. + +Figure I.1 – Scenario 1: Ambulance dispatch from hospital + +![Diagram of Scenario 2: Ambulance dispatch from emergency command centre. The diagram shows the same four entities as Figure I.1. Arrows indicate the flow: 1. Alarm call from the person to the Emergency command centre. 2. Dispatch an ambulance from the Emergency command centre to the Ambulance. 3. First aid on the scene from the person to the Ambulance. 4. Emergency transportation from the Ambulance to the Hospital. A legend on the right lists these four steps. The code F.760.1(22) is at the bottom right.](ab846b81e78dbc8da2a6f9511e2f248a_img.jpg) + +Emergency command centre + +Hospital + +1. Alarm call +2. Dispatch an ambulance +3. First aid on the scene +4. Emergency transportation + +F.760.1(22) + +Diagram of Scenario 2: Ambulance dispatch from emergency command centre. The diagram shows the same four entities as Figure I.1. Arrows indicate the flow: 1. Alarm call from the person to the Emergency command centre. 2. Dispatch an ambulance from the Emergency command centre to the Ambulance. 3. First aid on the scene from the person to the Ambulance. 4. Emergency transportation from the Ambulance to the Hospital. A legend on the right lists these four steps. The code F.760.1(22) is at the bottom right. + +Figure I.2 – Scenario 2: Ambulance dispatch from emergency command centre + +#### I.4.2 Pre-conditions + +A person suddenly fainted on the road. The entourage called the emergency command centre. The medical staff had arrived at the scene in an ambulance. Each piece of required equipment (5G/IMT-2020 remote B-ultrasound, remote ECG monitoring equipment, IoT bracelet, etc.) is: + +- powered up, and +- the emergency control link and data link have been established. + +#### **I.4.3 Service flows** + +- 1) After receiving the alarm, the emergency command centre will conduct standardized inquiries on the patient. +- 2) The emergency command centre will quickly dispatch an ambulance. + +**Scenario 1:** The emergency command centre can view the in-hospital emergency data of the hospitals in the area where the alarm occurs, such as the number of patients receiving emergencies and the number of remaining emergency beds. It grasps the real-time reception capabilities of each hospital and notifies the hospital to dispatch an ambulance and medical staff. + +**Scenario 2:** The emergency command centre generates the best and fastest driving route for the ambulance based on the positioning and search and rescue system and grasps the driving situation of the ambulance in real time. After receiving the dispatch order, the ambulance will set off within the specified time according to the location provided by the positioning and search and rescue system. + +- 3) Before the ambulance arrives, the medical staff in the ambulance will give patients first aid guidance through the 5G/IMT-2020 network slicing. +- 4) The onboard emergency system can produce patient handover orders in advance so that the hospital can triage according to the received patient information in advance and quickly hand over patients after the ambulance enters the hospital. + +#### **I.4.4 Post-conditions** + +The emergency command centre records ambulances, drivers, patients and medical staff onboard to ensure that the whole process can be analysed and traced. + +## **I.5 Emergency rescue equipment integration** + +#### **I.5.1 Description** + +Emergency rescue equipment integration should meet the system requirements of miniaturization, intelligence and integration, which includes the integration of new technologies and the integration of medical applications. New technologies refer to 5G/IMT-2020, IoT, big data, artificial intelligence, etc. Medical applications refer to 5G/IMT-2020 remote B-ultrasound, 5G/IMT-2020 ICU, VR diagnosis and treatment, remote video interaction, remote emergency command platform, etc. It can provide high-quality life support for critically ill patients by performing cardiopulmonary resuscitation, mechanical ventilation, cardiac defibrillation, vital signs detection, etc. + +#### **I.5.2 Pre-conditions** + +The ambulance is equipped with first aid equipment and a 5G/IMT-2020 access gateway. The first-aid kit includes monitors, ventilators, infusion pumps, blood gas analysers, high-definition audio and video monitoring, 5G/IMT-2020 mobile smart devices, etc. The 5G/IMT-2020 access gateway is responsible for communicating with first-aid equipment to seamlessly integrate the first-aid kit and the 5G/IMT-2020 emergency cloud platform. + +Each piece of required equipment (5G/IMT-2020 remote B-ultrasound, remote ECG monitoring equipment, IoT bracelet, etc.) is: + +- powered up, and +- the emergency control link and data link have been established. + +#### **I.5.3 Service flows** + +- 1) Medical staff use real-time high-definition audio and video interactive systems, under the guidance of remote diagnosis and treatment of hospital medical staff, use a vehicle-mounted defibrillator for other rescues or use a non-invasive ventilator for assisted ventilation. +- 2) The 5G/IMT-2020 access gateway collects the patient's vital signs data in real time, extracts or translates the data, and uploads it to the emergency cloud platform through the 5G/IMT-2020 network slicing. + +#### **I.5.4 Post-conditions** + +The ambulance successfully sent the patient to the hospital and transmitted vital signs data to the emergency cloud platform. + +## **I.6 Emergency rescue for natural disasters and accident disasters** + +#### **I.6.1 Description** + +Natural disasters include meteorological disasters, earthquake disasters, geological disasters, forest and grassland fires, etc. Accident disasters include major traffic accidents, major environmental pollution, nuclear radiation accidents, ecological damage accidents, etc. + +#### **I.6.2 Pre-conditions** + +A vicious traffic accident occurred on a particular highway, and dozens of people were injured. They have called the police and medical staff have rushed to the scene in an ambulance and drones. + +Each piece of required equipment (5G/IMT-2020 remote B-ultrasound, remote ECG monitoring equipment, IoT bracelet, etc.) is: + +- powered up, and +- the emergency control link and data link have been established. + +#### **I.6.3 Service flows** + +- 1) Deal with the alarm. The emergency command centre quickly analyses and accurately handles major traffic accidents' alarm locations and handles alarm affairs promptly. +- 2) Search and locate the wounded. Before the ambulance arrives at the location, if there are traffic jams, the medical staff on the ambulance will have used drones to search and locate all those injured in the traffic accident. +- 3) Collect data of injured persons. The on-site medical staff collected the injury information of all personnel at the traffic accident scene through the medical information collection terminal. It classified them into critical, severe, moderate and mild conditions according to the injured location, cause of injury and type of injury. The injury information is transmitted to the emergency medical information system through the 5G/IMT-2020 network. +- 4) Connect remote consultation. Medical experts provide real-time video consultation and technical guidance for on-site diagnosis and treatment based on the information of the wounded through the remote emergency consultation system. +- 5) Real-time monitoring of the wounded. Each wounded person will be equipped with IoT bracelets and GNSS positioning equipment. The on-site medical staff will continuously monitor the critically wounded's condition and transmit the data to the remote medical centre. Based on the positioning and search and rescue system, the wounded are located and tracked in real time. + +#### **I.6.4 Post-conditions** + +All the wounded and sick have been treated in a timely and effective manner, and the hospital has allocated medical emergency resources. + +## I.7 Emergency rescue for public health emergencies + +#### I.7.1 Description + +Public health emergencies include major epidemics, mass diseases of unknown origin, major food and occupational poisoning, etc. + +#### I.7.2 Pre-conditions + +A cluster of COVID-19 infections occurred in a particular place, and many alarms were issued. The medical staff have rushed to the scene in an ambulance. + +Each piece of required equipment (remote ECG monitoring equipment, IoT bracelet, etc.) is: + +- powered up, and +- the emergency control link and data link have been established. + +#### I.7.3 Service flows + +- 1) Deal with the alarm. The emergency command centre handles alarm affairs promptly. +- 2) Dispatch an ambulance. The ambulance needs to carry COVID-19 antigen rapid test cassettes and medical oxygen cylinders, and the medical staff needs to wear protective clothing that meets the requirements for epidemic protection. According to the information provided by the positioning and search and rescue system, the ambulance quickly arrives at the emergency scene. +- 3) After the ambulance arrives at the scene, medical staff initially confirm that patients have contracted COVID-19 in about twenty minutes, enter patient data through voice, and obtain historical medical record information through the emergency medical information system. +- 4) The medical staff diagnose whether the patient was with mild or severe symptoms. Patients with mild symptoms are sent to a rapid deployment hospital, and patients with severe symptoms are sent to the hospital ICU. The experts in the hospital can carry out remote guidance. + +![Diagram illustrating the emergency rescue process for public health emergencies. It shows the flow from an alarm call to an emergency command centre, then to an ambulance dispatch, first aid on the scene, and finally transfer to a hospital ICU or rapid deployment hospital.](bb3354f497635d15bef873577125c48d_img.jpg) + +The diagram illustrates the emergency rescue process for public health emergencies. It features three main locations: a 'Rapid deployment hospital' (yellow building), a 'Hospital ICU' (blue building with a red cross), and an 'Emergency command centre' (blue building with a helipad). A black ambulance with a white cross is shown in the center. A cell tower is on the left, and a person on a stretcher is being attended to by two people on the right. Arrows indicate the flow of the rescue process: 1. Alarm call from the person on the stretcher to the Emergency command centre. 2. Dispatch an ambulance from the Emergency command centre to the person on the stretcher. 3. First aid on the scene by the person on the stretcher. 4. Transfer to hospital ICU or rapid deployment hospital from the person on the stretcher. A lightning bolt symbol connects the cell tower to the ambulance. The text 'F.760.1(22)' is visible near the bottom right. + +1. Alarm call +2. Dispatch an ambulance +3. First aid on the scene +4. Transfer to hospital ICU or rapid deployment hospital + +F.760.1(22) + +Diagram illustrating the emergency rescue process for public health emergencies. It shows the flow from an alarm call to an emergency command centre, then to an ambulance dispatch, first aid on the scene, and finally transfer to a hospital ICU or rapid deployment hospital. + +Figure I.3 – Emergency rescue for public health emergencies + +#### I.7.4 Post-conditions + +The emergency command centre has successfully found the source of infection and cut off the route of transmission to protect other people from disease. + +# Bibliography + +[b-3GPP TR 22.826] 3GPP TR 22.826 V17.2.0 (2021), *Study on communication services for critical medical applications*. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.760.3-202503-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg b/marked/F/T-REC-F.760.3-202503-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d4d8969f805414689ab79cfd08c333d454d482b3 --- /dev/null +++ b/marked/F/T-REC-F.760.3-202503-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:636c3839edff955a5b6208530b05fa1c983ab153d90f00216517a7a99478b988 +size 7074 diff --git a/marked/F/T-REC-F.760.3-202503-I_PDF-E/5860ad6bd2a2dd8d1ab12864b8f90f37_img.jpg b/marked/F/T-REC-F.760.3-202503-I_PDF-E/5860ad6bd2a2dd8d1ab12864b8f90f37_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..204340a491eb02f976269eb74cb73c8f3cb1a18c --- /dev/null +++ b/marked/F/T-REC-F.760.3-202503-I_PDF-E/5860ad6bd2a2dd8d1ab12864b8f90f37_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:4af5f1cc1ff585dd48686d036a8315381c77de9abd93e1ca2961d766d42b4765 +size 70075 diff --git a/marked/F/T-REC-F.760.3-202503-I_PDF-E/raw.md b/marked/F/T-REC-F.760.3-202503-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..7ace1fd331b47936df5796526fc911eac0605b02 --- /dev/null +++ b/marked/F/T-REC-F.760.3-202503-I_PDF-E/raw.md @@ -0,0 +1,1446 @@ + + +# Recommendation **ITU-T F.760.3 (03/2025)** + +SERIES F: Non-telephone telecommunication services + +Multimedia services + +## --- **Metadata for disaster information presentation with human factors** + +![ITU logo](0538daaa5583c23e17db3a12f2281a55_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.760.3 + +## Metadata for disaster information presentation with human factors + +## Summary + +Recommendation ITU-T F.760.3 specifies metadata for presenting disaster information (MDI), encompassing both natural and social disaster information. It defines the metadata elements and data types required to deliver disaster information-based services, incorporating human factors to enhance the effectiveness of information presentation. + +The disaster classification system is divided into natural and social disaster systems depending on the cause of the disaster. Natural disasters are again largely classified into 5 categories, including weather, sluice, climate, geology, and astronomical phenomena, and each category is further classified into subcategories, and metadata for a total of 21 types of disasters is defined. Non-natural disasters are again largely classified into 10 categories, including fire, explosion, collapse, traffic, chemical/biological/radiological, environmental pollution, nation-based system, paralysis, epidemic, disease, safety, etc., and each category is further classified into subcategories, and metadata for a total of 40 types of disasters is defined. + +Such metadata for disaster information will enable the systematic collection and storage of disaster information, which will not only activate the provision of various disaster information-based services, but also be used to prevent disasters or minimize human and material damage by analysing the collected disaster information. + +## History \* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.760.3 | 2025-03-16 | 21 | 11.1002/1000/16245 | + +## Keywords + +Disaster information presentation, metadata, natural disaster, social disaster. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2025 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +###### Page + +| | | | +|------|----------------------------------------------------------------------------------------------------------------|----| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| 3.1 | Terms defined elsewhere ..... | 1 | +| 3.2 | Terms defined in this Recommendation..... | 1 | +| 4 | Abbreviations and acronyms ..... | 1 | +| 5 | Conventions ..... | 2 | +| 6 | Introduction ..... | 2 | +| 7 | Disaster classification system..... | 2 | +| 7.1 | Natural disaster classification..... | 3 | +| 7.2 | Social disaster classification..... | 3 | +| 8 | Metadata for presenting natural disaster information with human factors ..... | 5 | +| 8.1 | Metadata for presenting weather disaster information with human factors ... | 5 | +| 8.2 | Metadata for presenting sluice disaster information with human factors..... | 9 | +| 8.3 | Metadata for presenting climate disaster information with human factors .... | 11 | +| 8.4 | Metadata for presenting geology disaster information with human factors ... | 12 | +| 8.5 | Metadata for presenting astronomical phenomena disaster information
with human factors ..... | 14 | +| 9 | Metadata for presenting social disaster information..... | 15 | +| 9.1 | Metadata for presenting fire disaster information with human factors ..... | 15 | +| 9.2 | Metadata for explosion disaster information presentation with human
factors ..... | 16 | +| 9.3 | Metadata for collapse disaster information presentation with human
factors ..... | 17 | +| 9.4 | Metadata for traffic disaster information presentation with human factors ... | 18 | +| 9.5 | Metadata for presenting chemical, biological and radiological disaster
information with human factors ..... | 20 | +| 9.6 | Metadata for presenting environmental pollution disaster information
with human factors ..... | 24 | +| 9.7 | Metadata for nation-based system paralysis disaster information
presentation with human factors..... | 26 | +| 9.8 | Metadata for epidemic disease disaster information presentation with
human factors ..... | 30 | +| 9.9 | Metadata for presenting safety disaster information with human factors .... | 33 | +| 9.10 | Metadata for presenting other disaster information with human factors..... | 35 | +| | Bibliography..... | 38 | + + + +# Recommendation ITU-T F.760.3 + +## Metadata for disaster information presentation with human factors + +## 1 Scope + +This Recommendation specifies metadata for presenting disaster information, including both natural and social disaster information. + +The scope of this Recommendation includes: + +- Overview of disaster information presentation with human factors +- Metadata for the natural disaster information presentation +- Metadata for the social disaster information presentation. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +None. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 common alerting protocol** [b-ITU-T X.1303]: A simple but general format for exchanging all-hazard emergency alerts and public warnings over all kinds of networks. + +**3.1.2 disaster** [b-UNISDR], [b-ITU-T FG-DR&NRR]: A serious disruption of the functioning of a community or a society involving widespread human, material, economic or environmental losses and impacts, which exceeds the ability of the affected community or society to cope using its own resources. + +### 3.2 Terms defined in this Recommendation + +None. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-----|--------------------------| +| CAP | Common Alerting Protocol | +| M | Mandatory | +| ND | Natural Disaster | +| O | Optional | +| SD | Social Disaster | + +## 5 Conventions + +None. + +## 6 Introduction + +Because disasters can cause enormous damage to people's lives, bodies, property, or nations, countries have established systems for delivering disaster information. These disasters can be divided into natural and non-natural disasters. The first are caused by natural phenomena such as typhoons, floods, heavy rains, earthquakes, and heavy snow. The second type of disasters have a man-made/technical origin (i.e., caused by human activities/intervention such as fire, explosion, traffic accidents, chemical, biological, radiological accidents, environmental pollution accident, etc.), socio-technical origin (i.e., caused by impacts on social infrastructure such as energy, communications, transportation, finance, medical, and water supply), and other human-related origin (e.g., damage caused by the spread of infectious diseases or livestock epidemics). Hereinafter in this Recommendation the second type of disaster is referred to as a social disaster. + +In the event of a disaster, the facts are delivered through broadcasting or communication networks. Disaster broadcasting provides relevant information through the broadcasting or communication network when such a disaster occurs or is expected to occur. As a result, disaster broadcasting can reduce the damage by providing information necessary for evacuation, rescue, and recovery in the event of a disaster. + +Figure 1 shows a typical disaster alerting delivery system. The disaster alerting issuer issues a disaster alerting message based on the common alerting protocol (CAP). The disaster alerting delivery authority converts the received CAP message according to the receiving terminal and delivers it to the disaster alerting receiving terminal. Once a disaster alerting message is sent, people can receive a disaster alerting message through various receivers such as TV, radio, smartphone, Internet, and digital signage. + +![Figure 1 – Typical disaster alerting delivery system diagram](5860ad6bd2a2dd8d1ab12864b8f90f37_img.jpg) + +The diagram illustrates the flow of disaster alerting information through three main stages, each enclosed in a dashed box: + +- Disaster alert issuance:** This stage includes five boxes representing different levels of government: Local, State, Territorial, Tribal, and Federal. An arrow labeled "Collect information and deliver to service provider" points from this stage to the next. +- Disaster alert delivery:** This stage includes three boxes: Emergency alert system, Mobile alert service, and Internet alert service. An arrow labeled "Broadcasting network and communication network" points from this stage to the final stage. +- Disaster alert reception:** This stage includes seven boxes representing various receiving terminals: TV, Radio, Cell phone, Web apps, Social media, Digital signage, and Sirens. + +F.760.3(25) + +Figure 1 – Typical disaster alerting delivery system diagram + +**Figure 1 – Typical disaster alerting delivery system** + +Metadata for disaster information presentation may include the type of disaster, location of occurrence, time of occurrence, intensity, and magnitude of disaster damage. However, specific metadata components vary depending on the type of disaster. + +## 7 Disaster classification system + +This clause addresses the disaster classification system. + +### 7.1 Natural disaster classification + +The classification code for displaying each classification item is composed of two digits of the English alphabet meaning main category and two digits each representing middle category and sub-category. In the main category, 'ND' represents natural disaster. The middle and sub-categories can be numbered from 01 to 99. Table 1 shows the items and codes for each category. + +**Table 1 – Categories for natural disaster** + +| Main category | Main category code | Middle category | Middle category code | Sub-category | Sub-category code | +|------------------|--------------------|------------------------|----------------------|--------------------|-------------------| +| Natural disaster | ND | Weather | ND-01 | Typhoon | ND-01-01 | +| | | | | Heavy snow | ND-01-02 | +| | | | | Downpour | ND-01-03 | +| | | | | Dust storm | ND-01-04 | +| | | | | Fine dust | ND-01-05 | +| | | | | Strong wind | ND-01-06 | +| | | | | Thunderstroke | ND-01-07 | +| | | | | Hail | ND-01-08 | +| | | Sluice | ND-02 | Green algae | ND-02-01 | +| | | | | Red tide | ND-02-02 | +| | | | | High seas | ND-02-03 | +| | | | | Tsunami | ND-02-04 | +| | | | | Floods | ND-02-05 | +| | | Climate | ND-03 | Drought | ND-03-01 | +| | | | | Heat wave | ND-03-02 | +| | | | | Cold wave | ND-03-03 | +| | | Geology | ND-04 | Earthquake | ND-04-01 | +| | | | | Landslide | ND-04-02 | +| | | | | Volcano | ND-04-03 | +| | | Astronomical phenomena | ND-05 | Space object crash | ND-05-01 | +| | | Astronomical phenomena | ND-05 | Space radio | ND-05-02 | + +### 7.2 Social disaster classification + +The classification code for displaying each classification item is composed of two digits of the English alphabet meaning main category and two digits each representing middle category and sub-category. In the main category, 'SD' represents social disaster. The middle and sub-categories can be numbered from 01 to 99. Table 2 shows the items and codes for each category. + +**Table 2 – Categories for social disaster** + +| Main category | Main category code | Middle category | Middle category code | Sub-category | Sub-category code | +|-----------------|--------------------|-------------------------------|----------------------|--------------------------------------------------------|-------------------| +| Social disaster | SD | Fire | SD-01 | Fire accident | SD-01-01 | +| | | | | Forest fire | SD-01-02 | +| | | Explosion | SD-02 | Explosion accident | SD-02-01 | +| | | Collapse | SD-03 | Steep slope collapse accident | SD-03-01 | +| | | | | Dam collapse accident | SD-03-02 | +| | | | | Facility collapse accident | SD-03-03 | +| | | Traffic | SD-04 | Road traffic accident | SD-04-01 | +| | | | | Railroad accident | SD-04-02 | +| | | | | Aircraft accident | SD-04-03 | +| | | | | Marine ship accident | SD-04-04 | +| | | CBR | SD-05 | Radiation leakage accident | SD-05-01 | +| | | | | Nuclear facility accident in neighbouring countries | SD-05-02 | +| | | | | Radioactive leakage accident | SD-05-03 | +| | | | | Biological material accident | SD-05-04 | +| | | | | Chemical accident | SD-05-05 | +| | | Environmental pollution | SD-06 | Air pollution accident | SD-06-01 | +| | | | | Water pollution accident | SD-06-02 | +| | | | | Soil pollution accident | SD-06-03 | +| | | | | Marine pollution accident | SD-06-04 | +| | | Nation-based system paralysis | SD-07 | Transportation infrastructure accident | SD-07-01 | +| | | | | Financial infrastructure accident | SD-07-02 | +| | | | | Health care infrastructure accident | SD-07-03 | +| | | | | Drinking water infrastructure accident | SD-07-04 | +| | | | | Energy infrastructure accident | SD-07-05 | +| | | | | Information and communications infrastructure accident | SD-07-06 | +| | | | | Important government facility accident | SD-07-07 | +| | | | | Environmental infrastructure accident | SD-07-08 | + +**Table 2 – Categories for social disaster** + +| Main category | Main category code | Middle category | Middle category code | Sub-category | Sub-category code | +|---------------|--------------------|------------------|----------------------|-----------------------------|-------------------| +| | | Epidemic disease | SD-08 | Livestock epidemic diseases | SD-08-01 | +| | | | | Pets epidemic diseases | SD-08-02 | +| | | | | Zoonotic epidemic diseases | SD-08-03 | +| | | | | Human epidemic diseases | SD-08-04 | +| | | Safety | SD-09 | Home safety accident | SD-09-01 | +| | | | | Public safety accident | SD-09-02 | +| | | | | Crime safety accident | SD-09-03 | +| | | | | Industrial safety accident | SD-09-04 | +| | | | | School safety accident | SD-09-05 | +| | | Etc. | SD-10 | Cultural heritage accident | SD-10-01 | +| | | | | Wartime disaster | SD-10-02 | +| | | | | Terrorism | SD-10-03 | +| | | | | Overseas disaster | SD-10-04 | + +## 8 Metadata for presenting natural disaster information with human factors + +This clause addresses metadata for presenting natural disaster information. + +### 8.1 Metadata for presenting weather disaster information with human factors + +This clause addresses metadata for presenting weather disaster information. + +#### 8.1.1 Typhoons + +Table 3 shows the metadata for presenting typhoon disaster information. + +**Table 3 – Metadata for presenting typhoon disaster information** + +| Element | Description | Datatype | Mandatory (M) or Optional (O) | +|--------------------------|-------------------------------------------------------------|-----------|-------------------------------| +| DisasterType | Identifies the type of disaster. | xs:string | M | +| OccurrenceTime | Describes the time of typhoons occurrence. | xs:time | M | +| CenterLocationLatitude | Describes the centre location of latitude. | xs:float | M | +| CenterLocationLongitude | Describes the centre location of longitude. | xs:float | M | +| CenterAtmospherpPressure | Describes the centre atmosphere pressure. | xs:float | M | +| MaxWindSpeed | Describes the maximal wind speed as per second or per hour. | xs:float | M | +| StrongWindRadius | Describes the radius of the strong wind. | xs:string | M | +| Strength | Describes the strength of the typhoon. | xs:string | M | + +**Table 3 – Metadata for presenting typhoon disaster information** + +| Element | Description | Datatype | Mandatory (M) or Optional (O) | +|----------------|-----------------------------------------|-----------------|--------------------------------------| +| Magnitude | Describes the magnitude of the typhoon. | xs:integer | M | +| Direction | Describes the direction of movement. | xs:string | M | +| Speed | Describes the speed of movement. | xs:float | M | + +#### 8.1.2 Heavy snowfall + +Table 4 shows the metadata for presenting heavy snowfall disaster information. + +**Table 4 – Metadata for presenting heavy snowfall disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-------------------|----------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| DisasterType | Identifies the type of disaster. | xs:string | M | +| AlertType | Describes the type of alerting disaster. The type can be snowfall warning or intensive snowfall warning. | xs:string | M | +| IssuingTime | Describes the time of issuing disaster. | xs:time | M | +| EstimatedSnowfall | Describes the estimated amount of the snowfall. | xs:integer | M | +| InfluenceArea | Describes the area within the influence of heavy snowfall. | xs:string | M | +| Instruction | Describes the instructions to be followed in case of having trouble because of heavy snowfall. | xs:string | O | + +#### 8.1.3 Downpour + +Table 5 shows the metadata for presenting downpour disaster information. + +**Table 5 – Metadata for presenting downpour disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------------|------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| DisasterType | Identifies the type of disaster. | xs:string | M | +| SpecialNoticePeriod | Describes period during which special warnings such as downpour advisories and warnings were issued. | xs:string | M | +| ExpectedPrecipitation | Describes the amount of rain estimated by counting in advance (mm). | xs:integer | M | +| CurrentPrecipitation | Describes amount of rain at the current time (mm). | xs:integer | M | +| TotalPrecipitation | Describes total amount of rain from the time it rained to the present (mm). | xs:integer | M | +| TrafficControlZone | Describes areas where traffic is temporarily suspended due to downpour. | xs:string | M | + +#### 8.1.4 Dust storm + +Table 6 shows the metadata for presenting dust storm disaster information. + +**Table 6 – Metadata for presenting dust storm disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|---------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------|-----------------------| +| DisasterType | Identifies the type of disaster. | xs:string | M | +| DustConcentration | Describes the amount of dust distributed in the air ( $\mu\text{g}/\text{m}^3$ ). | xs:integer | M | +| WarningLevel | Describes the environmental level, which is one of three levels based on the degree of dust pollution in the air.
The level can be 'Top', 'Middle' or 'Bottom'. | xs:integer | M | +| SpecialNoticePeriod | Describes the period during which special warnings, such as dust advisories and warnings, were issued. | xs:string | M | + +#### 8.1.5 Fine dust + +Table 7 shows the metadata for presenting fine dust storm disaster information. + +**Table 7 – Metadata for presenting fine dust disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|---------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------|-----------------------| +| DisasterType | Identifies the type of disaster. | xs:string | M | +| DustConcentration | Describes the amount of dust distributed in the air ( $\mu\text{g}/\text{m}^3$ ). | xs:integer | M | +| WarningLevel | Describes the environmental level, which is one of three levels based on the degree of fine dust pollution in the air. The level can be 'Top', 'Middle' and 'Bottom'. | xs:integer | M | +| SpecialNoticePeriod | Describes the period during which special warnings such as fine dust advisories and warnings were issued | xs:string | M | + +#### 8.1.6 Strong wind + +Table 8 shows the metadata for presenting strong wind disaster information. + +**Table 8 – Metadata for presenting strong wind disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|------------------------|--------------------------------------------------------------|------------|-----------------------| +| DisasterType | Identifies the type of disaster. | xs:string | M | +| OccurrenceTime | Describes the time of strong wind occurrence. | xs:time | M | +| MaximumWindSpeed (m/s) | Describes the maximum speed of strong winds in second (m/s). | xs:integer | M | + +**Table 8 – Metadata for presenting strong wind disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-------------------------|-------------------------------------------------------------|------------------|------------------------------| +| MaximumWindSpeed (km/h) | Describes the maximum speed of strong winds in hour (km/h). | xs:integer | M | +| StrongWindRadius | Describes the wind radius (km). | xs:integer | M | +| Strength | Describe the strength of strong wind. | xs:integer | M | +| Magnitude | Describes the magnitude of strong wind. | xs:integer | M | + +#### **8.1.7 Thunderstroke** + +Table 9 shows the metadata for presenting thunderstroke disaster information. + +**Table 9 – Metadata for presenting thunderstroke disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|--------------------|-----------------------------------------------------------------------------|------------------|------------------------------| +| DisasterType | Identifies the type of disaster. | xs:string | M | +| OccurrenceTime | Describes the time of thunderstroke occurrence. | xs:time | M | +| OccurrenceLocation | Describes the location of thunderstroke occurrence. | xs:string | M | +| Shelter | Describes a safe place or location in the event of a thunderstroke. | xs:string | M | +| LossOfLife | Describes the scale of personal injury or death caused by thunderstroke. | xs:integer | O | +| PropertyDamage | Describes the scale of property or economic damage caused by thunderstroke. | xs:integer | O | + +#### **8.1.8 Hail** + +Table 10 shows the metadata for presenting hail disaster information. + +**Table 10 – Metadata for presenting hail disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|--------------------|--------------------------------------------------------------------|------------------|------------------------------| +| DisasterType | Identifies the type of disaster. | xs:string | M | +| OccurrenceTime | Describes the time of hail occurrence. | xs:time | M | +| OccurrenceLocation | Describes the location of hail occurrence. | xs:string | M | +| Shelter | Describes a safe place or location in the event of a hail. | xs:string | M | +| LossOfLife | Describes the scale of personal injury or death caused by hail. | xs:integer | O | +| PropertyDamage | Describes the scale of property or economic damage caused by hail. | xs:integer | O | + +### 8.2 Metadata for presenting sluice disaster information with human factors + +This clause addresses the metadata for presenting sluice disaster information. + +#### 8.2.1 Green algae + +Table 11 shows the metadata for presenting green algae disaster information. + +**Table 11 – Metadata for presenting green algae disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|--------------------|-------------------------------------------------------------------------------|------------|-----------------------| +| OccurrenceLocation | Describes specific places such as rivers or streams where green algae occurs. | xs:string | M | +| GreenAlgaeType | Describes the types of algae that caused algal blooms. | xs:string | M | +| OccurrenceNumber | Describes the number of occurrences of algal blooms during a specific period. | xs:integer | O | +| StayDuration | Describes the number of days that one occurrence of algae lasted(days). | xs:integer | O | +| DamageScale | Describes the amount or scope of property and human damages caused by algae. | xs:string | O | +| ResponseStatus | Describes the actions officially taken after the discovery of an algal bloom. | xs:string | O | + +#### 8.2.2 Red tide + +Table 12 shows the metadata for presenting red tide disaster information. + +**Table 12 – Metadata for presenting red tide disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|--------------------|----------------------------------------------------------------------------------|------------|-----------------------| +| OccurrenceLocation | Describes specific places, such as rivers or streams, where red tide occurs. | xs:date | M | +| RedTideType | Describes the types of algae that caused red tides, such as flagellates. | xs:integer | M | +| OccurrenceNumber | Describes the number of times red tides occurred during a specific period. | xs:integer | O | +| StayDuration | Describes the number of days that one red tide lasted (days). | xs:date | O | +| DamageScale | Describes the amount or scope of property and human damages caused by red tides. | xs:string | O | +| ResponseStatus | Describes the actions officially taken after the discovery of a red tide. | xs:string | O | + +#### 8.2.3 High seas + +Table 13 shows the metadata for presenting high seas disaster information. + +**Table 13 – Metadata for presenting high seas disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|--------------------|----------------------------------------------------------------------------------|------------------|------------------------------| +| OccurrenceLocation | Describes specific places where high seas occurs. | xs:string | M | +| IssuingTime | Describes the time when a high sea was issued. | xs:time | M | +| EffectTime | Describes the time in which the high seas are valid. | xs:time | M | +| DamageScale | Describes the amount or scope of property and human damages caused by high seas. | xs:string | O | + +#### **8.2.4 Tsunami** + +Table 14 shows the metadata for presenting tsunami disaster information. + +**Table 14 – Metadata for presenting tsunami disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|---------------------|-------------------------------------------------------------------------------------------|------------------|------------------------------| +| DisasterType | Identifies the type of disaster. | xs:string | M | +| OccurrenceTime | Describes the time of earthquake occurrence. | xs:time | M | +| Magnitude | Describes the magnitude of earthquake. | xs:integer | M | +| ArrivalTime | Describes the time of arrival to the local area. | xs:time | M | +| MaxWaveHeigh | Describes the maximum height of wave. | xs:integer | M | +| Latitude | Describes the latitude of earthquake occurred. | xs:float | M | +| Longitude | Describes the longitude of earthquake occurred. | xs:float | M | +| Location | Describes the location of the earthquake. | xs:string | M | +| EpicenterMapImage | Describes the map information of earthquake. | xs:string | M | +| DetailedInformation | Describes the detailed information of earthquake. | xs:string | O | +| Instruction | Describes instructions to be followed in case of having trouble because of an earthquake. | xs:string | O | + +#### **8.2.5 Floods** + +Table 15 shows the metadata for presenting flood disaster information. + +**Table 15 – Metadata for presenting flood disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|------------------|-------------------------------------------------|------------------|------------------------------| +| DisasterType | Identifies the type of disaster. | xs:string | M | +| ObservationTime | Describe the observation time of floods. | xs:time | M | +| ObservationPoint | Describe the observation point of floods. | xs:string | M | +| RiverName | Describe the river name for observation target. | xs:string | M | +| DamName | Describe the dam name for observation target. | xs:string | M | +| BeamName | Describe the beam name for observation target. | xs:string | M | + +**Table 15 – Metadata for presenting flood disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------------|-------------------------------------------------------------------------------------------|------------|-----------------------| +| UpstreamWaterLevel | Describe the water level of upstream.
The level can be 'Top', 'Middle' and 'Bottom'. | xs:integer | M | +| DownstreamWaterLevel | Describe the water level of downstream.
The level can be 'Top', 'Middle' and 'Bottom'. | xs:integer | M | +| InflowAmount | Describe the amount of inflow for observation target. | xs:integer | M | +| DischargeAmount | Describe the amount of discharge for observation target. | xs:integer | M | +| Precipitation | Describe the precipitation of rain. | xs:integer | M | +| FloodAdvisoryCriteria | Describes the criteria for issuing flood advisory. | xs:string | O | +| FloodWarningCriteria | Describes the criteria for issuing flood warnings. | xs:string | O | + +### 8.3 Metadata for presenting climate disaster information with human factors + +This clause addresses the metadata for presenting climate disaster information. + +#### 8.3.1 Drought + +Table 16 shows the metadata for presenting drought disaster information. + +**Table 16 – Metadata for presenting drought disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------|---------------------------------------------------------------------------------------------------------------|------------|-----------------------| +| IssuingTime | Describes the time the drought forecast was announced by the agency. | xs:time | M | +| EffectTime | Describes the time when the drought takes effect. | xs:time | M | +| OccurrenceArea | Describes the area of application where drought is in effect. | xs:string | M | +| Precipitation | Describes highest precipitation of the observed day. | xs:integer | M | +| RiskLevel | Describes one of three levels of upper, middle and lower levels divided according to the severity of drought. | xs:string | M | +| Duration | Describes the number of days with the highest temperature, which is a criterion for drought. | xs:string | M | +| Instruction | Describes the instructions to be followed in case of having trouble caused by drought. | xs:string | O | + +#### 8.3.2 Heat wave + +Table 17 shows the a metadata for presenting heat wave disaster information. + +**Table 17 – Metadata for presenting heat wave disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------|---------------------------------------------------------------------------------------------|------------------|------------------------------| +| IssuingTime | Describes the time the heat wave forecast was announced by the agency. | xs:time | M | +| EffectTime | Describes the time when the heat wave takes effect. | xs:time | M | +| OccurrenceArea | Describes the area where heat wave is in effect. | xs:string | M | +| Temperature | Describes the highest temperature of the observed day. | xs:integer | M | +| RiskLevel | Describes one of three levels (upper, middle and lower) based on the severity of heat wave. | xs:string | M | +| Duration | The number of days with the highest temperature, which is a criterion for heat wave. | xs:string | M | + +#### **8.3.3 Cold wave** + +Table 18 shows the metadata for presenting cold wave disaster information. + +**Table 18 – Metadata for presenting cold wave disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|--------------------|---------------------------------------------------------------------------------------------|------------------|------------------------------| +| IssuingTime | Describes the time the cold wave forecast was announced by the agency. | xs:time | M | +| EffectTime | Describes the time when the cold wave takes effect. | xs:time | M | +| OccurrenceArea | Describes the area where cold wave is in effect. | xs:string | M | +| MinimumTemperature | Describes the lowest temperature of the observed day. | xs:integer | M | +| TemperatureDrop | Describes the amount by which the temperature decreases. | xs:integer | M | +| RiskLevel | Describes one of three levels (upper, middle and lower) based on the severity of cold wave. | xs:string | M | +| Duration | The number of days with the highest temperature, which is a criterion for cold wave. | xs:string | M | + +### **8.4 Metadata for presenting geology disaster information with human factors** + +This clause addresses the metadata for presenting geology disaster information. + +#### **8.4.1 Earthquake** + +Table 19 shows the metadata for presenting earthquake disaster information. + +**Table 19 – Metadata for presenting earthquake disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|---------------------|---------------------------------------------------|------------------|------------------------------| +| DisasterType | Identifies the type of disaster. | xs:string | M | +| OccurrenceTime | Describes the time of earthquake occurrence. | xs:time | M | +| Magnitude | Describes the magnitude of earthquake. | xs:integer | M | +| Depth | Describes the depth of earthquake. | xs:integer | M | +| RegionMaxMagnitude | Describes the regional maximum magnitude. | xs:string | O | +| Latitude | Describes the latitude of earthquake occurred. | xs:string | M | +| Longitude | Describes the longitude of earthquake occurred. | xs:string | M | +| Location | Describes the location of the earthquake. | xs:string | M | +| EpicenterMapImage | Describes the map information of earthquakes. | xs:string | M | +| DetailedInformation | Describes the detailed information of earthquake. | xs:string | O | + +#### 8.4.2 Landslide + +Table 20 shows the metadata for presenting landslide disaster information. + +**Table 20 – Metadata for presenting landslide disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------|-------------------------------------------------------------------------------------|------------------|------------------------------| +| OccurrenceTime | Describes the time of landslide occurrence. | xs:time | M | +| OccurrenceArea | Describes the area where the landslide occurred. | xs:string | M | +| LandslideType | Identifies one of the landslide types among 'rockfall', 'topple' and 'debris flow'. | xs:string | M | +| LandslideFactor | Identifies one of the factors among the 'natural factors' and 'artificial factors'. | xs:string | M | +| Rainfall | Describes the rainfall in case that the cause is rain. | xs:integer | O | +| Magnitude | Describes the magnitude if the cause is landslide. | xs:integer | O | +| HumanCasualty | Describes the human casualties. | xs:string | O | +| PropertyDamage | Describes the damage of property. | xs:string | O | + +#### 8.4.3 Volcano + +Table 21 shows the metadata for presenting volcano disaster information. + +**Table 21 – Metadata for presenting volcano disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------|---------------------------------------------------------------------|------------------|------------------------------| +| OccurrenceTime | Describes the time of volcano eruption occurrence. | xs:time | M | +| MountainName | Describes the name of a mountain where a volcano eruption occurred. | xs:string | M | +| AshDirection | Describes the direction in which ash evolves. | xs:string | M | + +**Table 21 – Metadata for presenting volcano disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------------|------------------------------------------|------------------|------------------------------| +| AshSpeed | Describes the speed of ash. | xs:integer | M | +| FluteHeight | Describes the height of the flute. | xs:integer | M | +| VolcanicAltitude | Describes the altitude of a volcano. | xs:string | M | +| VolcanicEruptionType | Describes the type of volcanic eruption. | xs:string | O | +| HumanCasualty | Describes the human casualties. | xs:string | O | +| PropertyDamage | Describes the damage of property. | xs:string | O | + +### 8.5 Metadata for presenting astronomical phenomena disaster information with human factors + +This clause addresses the metadata for presenting astronomical phenomena disaster information. Astronomical phenomena is a term that refers to various physical and astronomical events that occur in outer space. Examples include the birth and death of stars, black holes, supernova explosions, comet orbits, planetary transits, solar and lunar eclipses, etc. + +#### 8.5.1 Space object crash + +Table 22 shows the metadata for presenting space object crash disaster information. + +**Table 22 – Metadata for presenting space object crash disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------------|--------------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| CrashTime | Describes the expected time of impact of space object to Earth. | xs:time | M | +| Type | Describes the type of space object. | xs:string | M | +| Size | Describes the size of space object. | xs:integer | M | +| ExpectedCrashLocation | Describes the expected point of impact of space object to Earth. | xs:string | M | +| Real-timeLocation | Describes the current location of space object in space. | xs:string | O | +| HumanCasualty | Describes the extent of human casualties resulting from the crash of a space object, including injuries or deaths. | xs:integer | M | +| EvacuationArea | Describes the place or location to safely evacuate to in case of space object crash. | xs:string | M | +| EvacuationRadius | Describes the distance (m) to evacuate from point of impact of space object. | xs:integer | M | + +#### 8.5.2 Space radio + +Table 23 shows the metadata for presenting space radio disaster information. + +**Table 23 – Metadata for presenting space radio disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------------|--------------------------------------------------------------------------------------------|------------------|------------------------------| +| AreaCoverage | Describes the area of interference from space radio waves. | xs:string | M | +| Duration | Describes the expected duration of interference from space radio waves. | xs:string | M | +| EstimatedRecoveryTime | Describes the expected time to recover from interference from space radio waves. | xs:time | M | +| DamageExtent | Describes the amount or extent of property and human damage caused by space radio waves. | xs:integer | O | +| ResponseStatus | Describes the official follow-up measures taken after the occurrence of space radio waves. | xs:string | O | +| CauseOfAccident | Describes the cause of the interference from space radio waves. | xs:string | O | + +## **9 Metadata for presenting social disaster information** + +This clause addresses the metadata for presenting social disaster information. + +### **9.1 Metadata for presenting fire disaster information with human factors** + +This clause addresses the metadata for presenting fire disaster information. + +#### **9.1.1 Forest fires** + +Table 24 shows the metadata for presenting forest fires disaster information. + +**Table 24 – Metadata for presenting forest fires disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------------|----------------------------------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| MountainName | Describes the name of mountain where the forest fires occurred. | xs:string | O | +| Causes | Describes the reasons for forest fires such as spontaneous combustion, ignition, arson, misfire, etc. | xs:string | O | +| ExpectedMovementPath | Describes the path along which forest fires are expected to develop and spread. | xs:string | O | +| WindDirection | Describes the wind direction (0~360°). | xs:string | M | +| WindSpeed | Describes the wind speed (m/s, km/h, mph, knot, etc.) | xs:integer | M | +| EffectiveHumidity | Describes the humidity (%) which numerically indicates the dry state of fibres such as wood and indicates the risk of fire occurrence. | xs:integer | O | +| Casualty | Describes the number of human casualties injured or killed due to forest fires. | xs:integer | O | +| PropertyDamage | Describes the amount of property or economic damage caused by forest fires. | xs:integer | O | + +**Table 24 – Metadata for presenting forest fires disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|--------------------------|--------------------------------------------------------------|------------------|------------------------------| +| EvacuatedResidentsNumber | Describes the number of people evacuated due to forest fire. | xs:integer | O | +| FireFightingForce | Describes the size of dispatched firefighting force. | xs:integer | O | + +#### **9.1.2 Fire accident** + +Table 25 shows the metadata for presenting fire accident disaster information. + +**Table 25 – Metadata for presenting fire accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------------|-------------------------------------------|------------------|------------------------------| +| OccurrenceTime | Describes the time of fire occurrence. | xs:time | M | +| Causes | Describes the cause of fire. | xs:string | O | +| HumanCasualty | Describes the human casualties. | xs:string | O | +| PropertyDamage | Describes the damage of property. | xs:string | O | +| MobilizationFirePower | Describes the fire power of mobilization. | xs:string | O | + +### **9.2 Metadata for explosion disaster information presentation with human factors** + +This clause addresses the metadata for presenting explosion disaster information. + +#### **9.2.1 Explosion accident** + +Table 26 shows the metadata for presenting explosion accident disaster information. + +**Table 26 – Metadata for presenting explosion disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------------|--------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| ExplosionFacilityType | Describes the type of specific target, such as the location or building, where the explosion occurred. | xs:string | M | +| ControlArea | Describes the area where access is temporarily restricted due to an explosion. | xs:string | M | +| EvacuationRadius | Describes the distance to evacuate from the point where the explosion occurred (m). | xs:integer | M | +| FirefightingForce | Describes the size of dispatched firefighting force. | xs:integer | O | +| Casualty | Describes the number of human damage resulting from injury or death due to an explosion. | xs:integer | O | +| PropertyDamage | Describes the amount of property or economic damage resulting from an explosion. | xs:integer | O | +| Cause | Describes the cause of explosion accident. | xs:string | M | +| InfluenceArea | Describes the extent of area affected by explosion. | xs:string | M | + +### 9.3 Metadata for collapse disaster information presentation with human factors + +This clause addresses the metadata for presenting collapse disaster information. + +#### 9.3.1 Steep slope collapse accident + +Table 27 shows the metadata for presenting steep slope collapse accident disaster information. + +**Table 27 – Metadata for presenting steep slope collapse accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|---------------------|-----------------------------------------------------------------------------------------------------------|------------|-----------------------| +| Cause | Describes the specific reason or situation that led to the steep slope collapse accident. | xs:string | O | +| SteepSlopeType | Describes one of the types such as artificial, retaining walls and embankments. | xs:string | M | +| IsRockfallCollapses | Describes the facts regarding whether a rockfall occurred. | xs:string | M | +| DisasterRisk | Describes one of the grades A, B, C, D, E. | xs:string | M | +| Casualty | Describes the amount of human damage resulting from injury or death due to steep slope collapse accident. | xs:integer | M | +| PropertyDamage | Describes the amount of property or economic damage due to steep slope collapse accident. | xs:integer | O | + +#### 9.3.2 Dam collapse accident + +Table 28 shows the metadata for presenting dam collapse accident disaster information. + +**Table 28 – Metadata for presenting dam collapse accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|--------------------|------------------------------------------------------------------------------------------------------------------|------------|-----------------------| +| Causes | Describes the specific reason or situation that led to the dam collapse accident. | xs:string | O | +| RiverName | Indicates the name of the river where the dam collapse occurred. | xs:string | M | +| AccidentImpactArea | Describes the areas where damage to life or property has occurred or is expected to occur due to a dam collapse. | xs:string | M | +| EvacuationSite | Describes a place or location to safely escape in the event of a dam collapse. | xs:string | M | +| ResponseStatus | Describes the details of follow-up measures officially taken after the dam collapse accident occurred. | xs:string | M | +| Casualty | Describes the amount of human damage resulting from injury or death due to dam collapse accident. | xs:integer | M | +| PropertyDamage | Describes the amount of property or economic damage resulting from dam collapse accident. | xs:integer | O | + +#### 9.3.3 Facility collapse accident + +Table 29 shows the metadata for presenting facility collapse accident disaster information. + +**Table 29 – Metadata for presenting facility collapse accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------|------------------------------------------------------------------------------------------------------------|------------|-----------------------| +| OccurrenceTime | Describes the time when facility collapse occurred. | xs:time | M | +| FacilityName | Describes the name or location of the facility where the collapse occurred. | xs:string | M | +| Cause | Describes the reasons for facility collapse, such as neglect of facility management and poor construction. | xs:string | O | +| Casualty | Describes the amount of human damage resulting from injury or death due to facility collapse accident. | xs:integer | M | +| ResponseStatus | Describes the details of follow-up measures officially taken after a facility collapse accident occurred. | xs:string | O | +| FacilityType | Describes the types of facilities such as bridges, tunnels, and waterworks. | xs:string | M | + +### 9.4 Metadata for traffic disaster information presentation with human factors + +This clause addresses the metadata for presenting traffic disaster information. + +#### 9.4.1 Road traffic accident + +Table 30 shows the metadata for presenting road traffic accident disaster information. + +**Table 30 – Metadata for presenting road traffic accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|------------------------|----------------------------------------------------------------------------------------------------------------|------------|-----------------------| +| Causes | Describes the reasons for road traffic accidents, including driver factors, road factors, and vehicle factors. | xs:string | O | +| RoadName | Describes the name of the road where the traffic accident occurred. | xs:string | M | +| AccidentSection | Describes the road section where a road traffic accident occurred. | xs:string | M | +| ControlSection | Describes the area where access is temporarily restricted due to road traffic accidents. | xs:string | M | +| Casualty | Describes the amount of human damage resulting from injury or death due to road traffic accidents. | xs:integer | M | +| PropertyDamage | Describes the amount of property or economic damage resulting from road traffic accidents. | xs:integer | O | +| ExpectedRecoveryPeriod | Describes the period when vehicles will be able to operate again. | xs:string | M | + +#### 9.4.2 Railroad accident + +Table 31 shows the metadata for presenting railroad accident disaster information. + +**Table 31 – Metadata for presenting railroad accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|------------------------|----------------------------------------------------------------------------------------------------------------------|------------|-----------------------| +| OccurrenceTime | Describes the time when the railroad accident occurred. | xs:time | M | +| AccidentClassification | Describes the classification of accidents that occur on railways, including tracks, trains, and stations. | xs:string | M | +| TrainNumber | Describes the train number in case of train accident. | xs:string | M | +| CarNumber | Describes the car number of the train where the train accident occurred. | xs:string | M | +| OperatingSection | Describes the section of the nearest departure and arrival station of the train where the railway accident occurred. | xs:string | M | +| PassengerNumber | Describes the number of people aboard the train where the railway accident occurred. | xs:integer | M | +| Cause | Describes the causes of railway accidents such as derailment, fire, arson, and poor safety management. | xs:string | O | +| Casualty | Describes the amount of human damage resulting from injury or death due to railway accident. | xs:integer | M | +| ExpectedRecoveryPeriod | Describes the period when will vehicles be able to operate again. | xs:string | M | + +#### 9.4.3 Aircraft accident + +Table 32 shows the metadata for presenting aircraft accident disaster information. + +**Table 32 – Metadata for presenting aircraft accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------------|------------------------------------------------------------------------------------------------------------------------------------|-----------|-----------------------| +| Cause | Describes the specific reason or circumstances that led to the aircraft accident. | xs:string | O | +| AircraftFlightNumber | Describes the aircraft flight number in case of an aircraft accident. | xs:string | M | +| AircraftAffiliation | Describes the name of the airline belonging to the aircraft where the accident occurred, such as Korean Air, Asiana Airlines, etc. | xs:string | M | +| AircraftType | Describes the aircraft models such as Airbus and Boeing. | xs:string | M | +| Departure | Describes the departure airport name of the aircraft where the accident occurred. | xs:string | M | +| Arrival | Describes the name of the arrival airport of the aircraft where the accident occurred. | xs:string | M | + +**Table 32 – Metadata for presenting aircraft accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|---------------------|----------------------------------------------------------------------------------------------|------------------|------------------------------| +| PassengerNumber | Describes the number of people aboard the aircraft in which the aircraft accident occurred. | xs:integer | M | +| RescuedPersonNumber | Describes the number of people rescued from aircraft in which an aircraft accident occurred. | xs:integer | M | +| MissingPersonNumber | Describes the number of people missing from aircraft in aircraft accidents. | xs:integer | M | + +#### 9.4.4 Marine vessel accident + +Table 33 shows the metadata for presenting marine vessel accident disaster information. + +**Table 33 – Metadata for presenting marine vessel accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|---------------------|--------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| Cause | Describes the specific reasons or circumstances that led to a marine vessel accident. | xs:string | O | +| ShipName | Describes the name of the vessel concerned in the event of a marine vessel accident. | xs:string | M | +| OperationSection | Describes the departure port and arrival port names of the vessel where the marine vessel accident occurred. | xs:string | M | +| AccidentArea | Describes the sea location where marine vessel accident occurred. | xs:string | M | +| ShipAffiliation | Describes the name of the company belonging to the vessel where the accident occurred. | xs:string | M | +| PeopleNumber | Describes the number of people aboard the vessel where the maritime vessel accident occurred. | xs:integer | M | +| RescuePersonNumber | Describes the number of people rescued from ships that have had marine accidents. | xs:integer | M | +| MissingPersonNumber | Describes the number of people missing from ships involved in maritime shipping accidents. | xs:integer | M | +| ResponseStatus | Describes the details of follow-up measures officially taken after a marine ship accident occurred. | xs:string | M | + +### 9.5 Metadata for presenting chemical, biological and radiological disaster information with human factors + +This clause addresses the metadata for presenting chemical, biological and radiological disaster information. + +#### 9.5.1 Radioactive leakage accident + +Table 34 shows the metadata for presenting radioactive leakage accident disaster information. + +**Table 34 – Metadata for presenting radioactive leakage accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|---------------------------|--------------------------------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| Cause | Describes the specific reason or situation that led to the radiation leak accident. | xs:string | O | +| LeakFacilityName | Describes the name of facility where radiation leak occurred. | xs:string | M | +| RadiationLevels | Describes the radioactivity levels measured at the site of a radiation leak (nGy/h). | xs:integer | M | +| RadioactiveSubstancesType | Describes the types of radioactive materials that caused specific radioactive leakage accidents, such as uranium, radium, and radon. | xs:string | M | +| Casualty | Describes the amount of human damage resulting from injury or death due to radioactive leakage accident. | xs:integer | M | +| EvacuationSite | Describes a place or location to avoid in order to stay safe in the event of a radioactive leak. | xs:string | M | +| EvacuationRadius | Describes the distance to evacuate from the point where the radiation leak occurred (m). | xs:integer | M | +| ResponseStatus | Describes the details of follow-up measures officially taken after a radiation leak accident occurred. | xs:string | M | + +#### 9.5.2 Nuclear facility accident + +Table 35 shows the metadata for presenting nuclear facility accident disaster information. + +**Table 35 – Metadata for presenting nuclear facility accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|---------------------------|--------------------------------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| Cause | Describes the specific reason or circumstances that led to the nuclear facility accident. | xs:string | O | +| NuclearFacilityName | Describes the name of facility where nuclear facility accident occurred. | xs:string | M | +| RadiationLevel | Describes the radiation levels measured in the area surrounding the nuclear facility accident (nGy/h). | xs:integer | M | +| RadioactiveSubstancesType | Describes the types of radioactive materials that caused specific radioactive leakage accidents, such as uranium, radium, and radon. | xs:string | M | +| IsRadioactiveLeak | Describes the determination of leakage of radioactive materials. | xs:string | M | +| Casualty | Describes the amount of human damage resulting from injury or death due to nuclear facility accident. | xs:integer | M | +| EvacuationSite | Describes a place or location to avoid in order to stay safe in the event of a nuclear facility accident. | xs:string | M | +| EvacuationRadius | Describes the distance to evacuate from the point where the nuclear facility accident occurred (m). | xs:integer | M | + +**Table 35 – Metadata for presenting nuclear facility accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------|----------------------------------------------------------------------------------------------------------|-----------|-----------------------| +| ResponseStatus | Describes the details of follow-up measures officially taken after a nuclear facility accident occurred. | xs:string | M | + +#### **9.5.3 Radioactive leakage accident in neighbouring countries** + +Table 36 shows the metadata for presenting disaster information of radioactive leakage accidents in neighbouring countries. + +**Table 36 – Metadata for presenting disaster information of radioactive leakage accidents in neighbouring countries** + +| Element | Description | Data type | Mandatory or Optional | +|---------------------------|-------------------------------------------------------------------------------------------------------------------------------------|------------|-----------------------| +| Cause | Describes the specific reason or circumstances that led to the radiation leak accident in a neighbouring country. | xs:string | O | +| CountryName | Describes the name of neighbouring country where radiation leak occurred. | xs:string | M | +| RadiationLevel | Describes the radioactivity levels measured at the site of a radiation leak (nGy/h). | xs:integer | M | +| RadioactiveSubstancesType | Describes the types of radioactive materials that caused specific radioactive leakage accidents, such as uranium, radium and radon. | xs:string | M | +| ImportedItems | Describes the items imported from neighbouring countries where radioactive leaks occurred. | xs:string | O | +| Casualty | Describes the amount of human damage caused by injury or death due to radiation leakage accidents in neighbouring countries. | xs:integer | M | +| EvacuationSite | Describes a safe place or location in the event of a radiation leak in a neighbouring country. | xs:string | M | +| EvacuationRadius | Describes the evacuation distance from the point where the radiation leak accident occurred in neighbouring countries (m). | xs:integer | M | +| ResponseStatus | Describes the details of follow-up measures officially taken after a radiation leak accident occurred in a neighbouring country. | xs:string | O | + +#### **9.5.4 Biological material accident** + +Table 37 shows the metadata for presenting biological material accident disaster information. + +**Table 37 – Metadata for presenting biological material accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|------------------|------------------------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| Cause | Describes the specific reason or situation that led to the biological material accident. | xs:string | O | +| SubstanceType | Describes the name of the type of harmful biological substance that caused the biological substance accident. | xs:string | M | +| PathogenName | Describes the name of the parasite that caused the infection. | xs:string | M | +| InfectionRoute | Describes the specific routes through which pathogens are spread, such as person-to-person infection and airborne infection. | xs:string | O | +| Casualty | Describes the amount of human damage resulting from injury or death due to biological material accident. | xs:integer | M | +| ControlArea | Describes the area where access is temporarily restricted due to a biological material incident. | xs:string | M | +| EvacuationRadius | Describes the distance to evacuate from the point where the biological material accident occurred (m). | xs:integer | M | +| ResponseStatus | Describes the details of follow-up actions officially taken after a biological material accident occurred. | xs:string | M | + +#### 9.5.5 Chemical accident + +Table 38 shows the metadata for presenting chemical accident disaster information. + +**Table 38 – Metadata for presenting chemical accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------------|------------------------------------------------------------------------------------------------|------------------|------------------------------| +| Cause | Describes the specific reason or situation that led to the chemical accident. | xs:string | O | +| HazardousChemicalName | Describes the name of the hazardous chemical that caused the chemical accident. | xs:string | M | +| AccidentCompany | Describes the name of company or location where chemical accident occurred. | xs:string | M | +| InhalationSymptoms | Describes the physical changes that occur when the chemical is inhaled. | xs:string | M | +| Casualty | Describes the amount of human damage resulting from injury or death due to chemical accidents. | xs:integer | M | +| ControlArea | Describes the areas where access is temporarily restricted due to chemical accidents. | xs:string | M | +| EvacuationRadius | Describes the distance to evacuate from the point where a chemical accident occurred (m). | xs:integer | M | +| EvacuationSite | Describes a safe place or location to escape in case of chemical accident. | xs:string | M | + +**Table 38 – Metadata for presenting chemical accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------|--------------------------------------------------------------------------------------------------|-----------|-----------------------| +| ResponseStatus | Describes the details of follow-up measures officially taken after a chemical accident occurred. | xs:string | M | + +### 9.6 Metadata for presenting environmental pollution disaster information with human factors + +This clause addresses the metadata for presenting environmental pollution disaster information. + +#### 9.6.1 Air pollution accident + +Table 39 shows the metadata for presenting air pollution accident disaster information. + +**Table 39 – Metadata for presenting air pollution accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|---------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------|-----------------------| +| Cause | Describes the specific reason or situation that led to the air pollution accident. | xs:string | O | +| PollutionSource | Describes the name of specific pollutant that caused air pollution incident. | xs:string | M | +| SpillIncidentAgency | Describes the name of company or organization that released air pollutants. | xs:string | M | +| IntegratedAirQualityIndex | Describes the air quality index for six representative pollutants, including ultrafine dust (PM2.5), fine dust (PM10), ozone (O3), nitrogen dioxide (NO2), carbon monoxide (CO), and sulphur dioxide (SO2). | xs:string | M | +| DamageRange | Describes the areas that have suffered human and property damage due to air pollution accidents. | xs:string | M | +| ResponseStatus | Describes the details of follow-up measures officially taken after an air pollution incident occurred. | xs:string | M | + +#### 9.6.2 Water pollution accident + +Table 40 shows the metadata for presenting water pollution accident disaster information. + +**Table 40 – Metadata for presenting water pollution accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------|----------------------------------------------------------------------------------------|-----------|-----------------------| +| Cause | Describes the specific reason or situation that led to the water pollution incident. | xs:string | O | +| PollutionSource | Describes the name of the specific pollutant that caused the water pollution incident. | xs:string | M | + +**Table 40 – Metadata for presenting water pollution accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|------------------------|---------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| AccidentArea | Describes the location where water pollution incident occurred. | xs:string | M | +| PollutionConcentration | Describes the total amount of organic carbon dissolved in water (TOC: total organic carbon). | xs:integer | M | +| DamageRange | Describes the areas that have suffered human and property damage due to water pollution accidents. | xs:string | M | +| DamageScale | Describes the amount or extent of property and human damage suffered due to water pollution. | xs:integer | O | +| ResponseStatus | Describes the details of follow-up measures officially taken after a water pollution incident occurred. | xs:string | M | + +#### 9.6.3 Soil contamination accident + +Table 41 shows the metadata for presenting soil contamination accident disaster information. + +**Table 41 – Metadata for presenting soil contamination accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------|-----------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| Cause | Describes the specific reason or situation that led to the soil contamination incident. | xs:string | O | +| PollutionSource | Describes the name of specific pollutant that caused the soil contamination incident. | xs:string | M | +| Landowner | Describes the owner of the land where the soil contamination incident occurred. | xs:string | M | +| DamageRange | Describes the areas that have suffered human and property damage due to soil contamination accidents. | xs:string | M | +| DamageScale | Describes the amount or extent of property and human damage suffered due to soil contamination incidents. | xs:string | O | + +#### 9.6.4 Marine pollution accident + +Table 42 shows the metadata for presenting marine pollution accident disaster information. + +**Table 42 – Metadata for presenting marine pollution accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------|---------------------------------------------------------------------------------------|------------------|------------------------------| +| Cause | Describes the specific reason or situation that led to the marine pollution incident. | xs:string | O | +| OccurrenceTime | Describes the time when marine pollution occurred. | xs:time | M | + +**Table 42 – Metadata for presenting marine pollution accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------|---------------------------------------------------------------------------------------------------------------------|------------|-----------------------| +| PollutionSource | Describes the name of specific pollutant that caused marine pollution incident. | xs:string | M | +| DamageRadius | Describes the distance where damage occurred centred on the point where the marine pollution incident occurred (m). | xs:integer | M | +| DamageScale | Describes the amount or extent of property and human damage suffered due to marine pollution incidents. | xs:integer | O | +| ResponseStatus | Describes the details of follow-up measures officially taken after a marine pollution incident occurred. | xs:string | M | + +### 9.7 Metadata for nation-based system paralysis disaster information presentation with human factors + +This clause addresses the metadata for presenting nation-based system paralysis disaster information. + +#### 9.7.1 Transportation infrastructure accident + +Table 43 shows the metadata for presenting transportation infrastructure accident disaster information. + +**Table 43 – Metadata for presenting transportation infrastructure accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|---------------------------|----------------------------------------------------------------------------------------------------------------------------------|------------|-----------------------| +| Cause | Describes the specific reason or circumstances that led to the transportation infrastructure accident. | xs:string | O | +| AccidentFacilityType | Describes the specific type of transportation infrastructure where the accident occurred, such as roads, railways, airways, etc. | xs:string | M | +| ServiceInterruptionStatus | Describes the section or area where service is suspended due to a transportation infrastructure accident. | xs:string | M | +| EstimatedRecoveryTime | Describes the estimated time for transportation infrastructure incident to be repaired and normal operations to resume. | xs:time | M | +| Casualty | Describes the amount of human damage resulting from injuries or deaths resulting from transportation infrastructure accidents. | xs:integer | M | +| PropertyDamage | Describes the amount of property or economic damage resulting from transportation infrastructure accidents. | xs:integer | O | + +**Table 43 – Metadata for presenting transportation infrastructure accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-------------|------------------------------------------------------------------------------------------------------------|-----------|-----------------------| +| ControlArea | Describes the areas where access is temporarily restricted due to transportation infrastructure incidents. | xs:string | M | + +#### 9.7.2 Financial infrastructure accident + +Table 44 shows the metadata for presenting financial infrastructure accident disaster information. + +**Table 44 – Metadata for presenting financial infrastructure accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------------|--------------------------------------------------------------------------------------------------------------------------|------------|-----------------------| +| Cause | Describes the specific reasons or circumstances that led to a financial infrastructure accident. | xs:string | O | +| AccidentAgency | Describes the name of specific financial institution where financial infrastructure incident occurred. | xs:string | M | +| OutagePeriod | Describes the specific length of time financial operations are disrupted due to a financial infrastructure incident. | xs:string | M | +| EstimatedRecoveryTime | Describes the estimated time when financial infrastructure incident will be recovered and normal operations will resume. | xs:time | M | +| DamageNetworkRange | Describes the specific extent of computer networks paralyzed by financial infrastructure incidents. | xs:string | M | +| DamageScale | Describes the amount or extent of property and human damage suffered as a result of a financial infrastructure incident. | xs:integer | O | +| ResponseStatus | Describes the details of follow-up actions officially taken after a financial infrastructure incident occurred. | xs:string | M | + +#### 9.7.3 Health care infrastructure accident + +Table 45 shows the metadata for presenting health care infrastructure accident disaster information. + +**Table 45 – Metadata for presenting health care infrastructure accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------------|---------------------------------------------------------------------------------------------------------|-----------|-----------------------| +| Cause | Describes the specific reasons or circumstances that led to a health care-based incident. | xs:string | O | +| AccidentFacilityType | Describes the specific types of accident facilities where health care-based accidents occurred, such as | xs:string | M | + +**Table 45 – Metadata for presenting health care infrastructure accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------------------|-----------------------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| | university hospitals, general hospitals, and disease control and prevention agency. | | | +| AlternativeMedicalFacility | Describes other medical facilities that can take over the functions of the medical institution where the accident occurred. | xs:string | M | +| SeriouslyIllPatientsStatus | Describes the number of patients diagnosed with severe illness. | xs:integer | M | +| Casualty | Describes the number of human casualties injured or killed due to health care infrastructure accidents. | xs:integer | M | +| ResponseStatus | Describes the official follow-up actions taken after a health care infrastructure incident occurs. | xs:string | M | + +#### 9.7.4 Drinking water infrastructure accident + +Table 46 shows the metadata for presenting drinking water infrastructure accident disaster information. + +**Table 46 – Metadata for presenting drinking water infrastructure accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------------|----------------------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| Cause | Describes the specific reasons or circumstances leading to a drinking water infrastructure incident. | xs:string | O | +| RelatedSewageFacility | Describes the specific sewer facility name where drinking water infrastructure incident occurred. | xs:string | M | +| SingularArea | Describes the areas where water supply is disrupted due to drinking water infrastructure incidents. | xs:string | M | +| DamageRadius | Describes the distance of damage centred on the point where the drinking water infrastructure incident occurred (m). | xs:integer | M | +| EstimatedRecoveryTime | Describes the estimated time for recovery from drinking water infrastructure incident and resumption of normal operations. | xs:time | M | +| Casualty | Describes the human casualties resulting from injury or death due to drinking water infrastructure damage. | xs:integer | O | +| ResponseStatus | Describes the official follow-up actions taken after a drinking water infrastructure incident. | xs:string | M | + +#### 9.7.5 Energy infrastructure accident + +Table 47 shows the metadata for presenting energy infrastructure accident disaster information. + +**Table 47 – Metadata for presenting energy infrastructure accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| Cause | Describes the specific reasons or circumstances that led to an energy infrastructure accident. | xs:string | O | +| FacilityName | Describes the specific energy infrastructure name where the energy infrastructure incident occurred. | xs:string | M | +| HazardousMaterialType | Describes the specific types of hazardous materials released from energy infrastructure incidents. | xs:string | M | +| RawMaterialType | Describes the types of raw materials that have become problematic due to energy infrastructure accidents, such as oil, coal, and natural gas. | xs:string | M | +| DamageScale | Describes the amount or extent of property and personnel damage suffered as a result of an energy infrastructure incident. | xs:integer | O | +| ResponseStatus | Describes the official follow-up actions taken after an energy infrastructure incident occurs. | xs:string | M | + +#### **9.7.6 Information and communications infrastructure accident** + +Table 48 shows the metadata for presenting information and communications infrastructure accident disaster information. + +**Table 48 – Metadata for presenting information and communications infrastructure accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-------------------------------|------------------------------------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| OccurrenceTime | Describes the time when the information and communication infrastructure incident occurred. | xs:time | M | +| TelecommunicationsCompanyName | Describes the name of specific telecommunication company where information and communication infrastructure incident occurred. | xs:string | M | +| HumanDamage | Describes the number of people who have suffered due to information and communication infrastructure accidents. | xs:integer | M | +| PropertyDamage | Describes the amount of property damage resulting from information and communication infrastructure accidents. | xs:integer | M | +| EstimatedRecoveryTime | Describes the estimated time for recovery of information and communications infrastructure incident and resumption of normal operations. | xs:time | M | +| Causes | Describes the specific reasons for information and communication infrastructure accidents such as fire, hacking, and flood damage. | xs:string | O | +| ResponseStatus | Describes the official follow-up actions taken after an energy infrastructure incident occurs. | xs:string | M | + +#### 9.7.7 Important government facility accident + +Table 49 shows the metadata for presenting important government facility accident disaster information. + +**Table 49 – Metadata for presenting important government facility accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|--------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------|-----------------------| +| Cause | Describes the specific reasons or circumstances that led to an accident at an important government facility. | xs:string | O | +| FacilityType | Describes the specific types of important government facilities where the accident occurred, such as the president's residence, general Government complex, bank, etc. | xs:string | M | +| NationalSecurityFacilityRating | Describes the specific grades of national security facilities, such as level A, level B, and level M. | xs:string | M | +| PropertyDamage | Describes the amount of property or economic damage resulting from accidents at important government facilities. | xs:integer | O | +| Casualty | Describes the amount of human damage resulting from injuries or deaths resulting from accidents at important government facilities. | xs:integer | M | +| EvacuationSite | Describes a place or location to safely avoid in the event of an accident at an important government facility. | xs:string | M | +| ResponseStatus | Describes the details of follow-up measures officially taken after an accident occurred at an important government facility. | xs:string | M | + +#### 9.7.8 Environmental infrastructure accident + +Table 50 shows the metadata for presenting environmental infrastructure accident disaster information. + +**Table 50 – Metadata for presenting environmental infrastructure accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|--------------|------------------------------------------------------------------------------------------------------------------------|-----------|-----------------------| +| Cause | Describes the specific reasons or circumstances that led to an environmental infrastructure accident. | xs:string | O | +| FacilityType | Describes the specific type of environmental infrastructure where the accident occurred, such as a power plant or dam. | xs:string | M | +| DamageRange | Describes the areas that have suffered human and property damage due to environmental infrastructure accidents. | xs:string | M | + +**Table 50 – Metadata for presenting environmental infrastructure accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------|-----------------------------------------------------------------------------------------------------------------------------------|------------|-----------------------| +| DamageScale | Describes the amount or extent of property and personnel damage suffered as a result of an environmental infrastructure incident. | xs:integer | O | +| ResponseStatus | Describes the details of follow-up actions officially taken after an environmental infrastructure incident occurs. | xs:string | M | + +### 9.8 Metadata for epidemic disease disaster information presentation with human factors + +This clause addresses the metadata for presenting epidemic disease disaster information. + +#### 9.8.1 Livestock epidemic diseases + +Table 51 shows the metadata for presenting livestock epidemic diseases disaster information. + +**Table 51 – Metadata for presenting livestock epidemic diseases disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------------|----------------------------------------------------------------------------------------------------------|------------|-----------------------| +| Cause | Describes the specific reason or situation that led to the outbreak of a livestock epidemic. | xs:string | O | +| LivestockType | Describes the types of livestock infected by livestock epidemics. | xs:string | M | +| PathogenName | Describes the name of pathogen causing livestock epidemic. | xs:string | M | +| ProhibitedConsumption | Describes the name of food made from livestock infected with infectious diseases. | xs:string | M | +| ContagionArea | Describes the areas where there is a risk of livestock infectious diseases spreading. | xs:string | M | +| DamageScale | Describes the amount or extent of property and human damage suffered due to livestock epidemics. | xs:integer | O | +| ResponseStatus | Describes the details of follow-up measures officially taken after the outbreak of a livestock epidemic. | xs:string | M | + +#### 9.8.2 Pests epidemic diseases + +Table 52 shows the metadata for presenting pests epidemic disaster information. + +**Table 52 – Metadata for presenting pests epidemic disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|------------------------------|---------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| PestsType | Describes the type of pest that caused the pest problem. | xs:string | M | +| DamagedAgricultural Products | Describes the types of agricultural products directly damaged by pests and diseases, such as rice and barley. | xs:string | M | +| DamageArea | Describes the areas damaged by pests and diseases. | xs:string | M | +| PropertyDamage | Describes the amount of property or economic damage due to pests and diseases. | xs:integer | O | +| ResponseStatus | Describes the details of follow-up measures officially taken after the occurrence of pests and diseases. | xs:string | M | + +#### **9.8.3 Zoonotic epidemic diseases** + +Table 53 shows the metadata for presenting zoonotic epidemic diseases disaster information. + +**Table 53 – Metadata for presenting zoonotic epidemic diseases disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------------|------------------------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| Cause | Describes the specific reason or situation that led to the occurrence of a zoonotic infectious disease. | xs:string | O | +| PathogenName | Describes the name of pathogen causing zoonotic infectious disease. | xs:string | M | +| InfectionRoute | Describes the specific routes through which pathogens are spread, such as person-to-person infection and zoonotic infection. | xs:string | M | +| MainSymptoms | Describes the symptoms of infection that appear in patients, such as fever, vomiting, and difficulty breathing. | xs:string | M | +| ConfirmedCasesNumber | Describes the number of patients diagnosed with zoonotic diseases. | xs:integer | M | +| DeathsNumber | Describes the number of patients who died from zoonotic diseases. | xs:integer | M | +| ResponseStatus | Describes the details of follow-up measures officially taken after the outbreak of a zoonotic infectious disease. | xs:string | M | + +#### **9.8.4 Human epidemic diseases** + +Table 54 shows the metadata for presenting human epidemic diseases disaster information. + +**Table 54 – Metadata for presenting human epidemic diseases disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|--------------------------------|--------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| InfectiousDiseaseName | Describes the specific name of the disease that caused the human infectious disease. | xs:string | M | +| ConfirmedCasesDailyNumber | Describes the number of patients diagnosed with human infectious diseases per day. | xs:integer | M | +| ConfirmedCasesCumulativeNumber | Describes the total number of patients diagnosed with human infectious diseases by the time of announcement. | xs:integer | M | +| ConfirmedPatientMovementPath | Describes the main routes where confirmed cases travelled, such as buildings and locations. | xs:string | O | +| InfectiousDiseaseHospital | Describes a specialized hospital designated to screen or treat patients with infectious diseases. | xs:string | M | +| SuspectedDiseaseSymptom | Describes the symptoms that suggest a person has the infectious disease. | xs:string | M | + +### 9.9 Metadata for presenting safety disaster information with human factors + +This clause addresses the metadata for presenting safety disaster information. + +#### 9.9.1 Home safety accident + +Table 55 shows the metadata for presenting home safety accident disaster information. + +**Table 55 – Metadata for presenting home safety accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------------|----------------------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| Cause | Describes the specific reason or situation that led to a home safety accident. | xs:string | M | +| AccidentFacilityName | Describes the facilities or places where home safety accidents occurred, such as playgrounds, day care centres, and homes. | xs:string | M | +| AccidentType | Describes the types of safety accidents that occur at home, such as falls, collisions, and slips. | xs:string | M | +| Casualty | Describes the amount of human damage resulting from injury or death due to home safety accidents. | xs:integer | M | + +#### 9.9.2 Public safety accident + +Table 56 shows the metadata for presenting public safety accident disaster information. + +**Table 56 – Metadata for presenting public safety accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|--------------------|---------------------------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| Cause | Describes the specific reason or situation that led to a public safety accident. | xs:string | M | +| PublicFacilityType | Describes the type of specific building or location where a public safety incident occurred, such as a school, gym, or theatre. | xs:string | M | +| ControlArea | Describes the areas where access is temporarily restricted due to public safety incidents. | xs:string | M | +| Casualty | Describes the amount of human damage resulting from injury or death due to public safety accidents. | xs:integer | M | +| ResponseStatus | Describes the details of follow-up measures officially taken after a public safety incident occurs. | xs:string | M | + +#### **9.9.3 Crime safety accident** + +Table 57 shows the metadata for presenting crime safety accident disaster information. + +**Table 57 – Metadata for presenting crime safety accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|---------------------------|----------------------------------------------------|------------------|------------------------------| +| CrimeType | Describes the types of crimes. | xs:string | M | +| CriminalPersonGender | Describes the offender's gender. | xs:string | M | +| CriminalPersonAge | Describes the offender's age. | xs:integer | M | +| CrimeLocation | Describes where the crime occurred. | xs:string | M | +| VictimPersonalInformation | Describes the victim's gender and age. | xs:string | M | +| IsArrested | Describes whether the criminal was arrested or not | xs:string | M | + +#### **9.9.4 Industrial safety accident** + +Table 58 shows the metadata for presenting industrial safety accident disaster information. + +**Table 58 – Metadata for presenting industrial safety accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|------------------------------|----------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| Cause | Describes the specific reason or situation that led to an industrial safety accident. | xs:string | M | +| IndustryClassification | Describes the specific industry classification system where industrial safety accidents occurred. | xs:string | M | +| IndustrialDangerousGoodsType | Describes the specific types of industrial hazardous substances that caused industrial safety accidents. | xs:string | M | + +**Table 58 – Metadata for presenting industrial safety accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------|----------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| AccidentType | Describes the specific types of occupational safety accidents such as falls, trappings, explosions, and fires. | xs:string | M | +| Casualty | Describes the amount of human damage resulting from injury or death due to industrial safety accidents. | xs:integer | M | +| PropertyDamage | Describes the amount of property or economic damage resulting from industrial safety accidents. | xs:integer | O | + +#### **9.9.5 School safety accident** + +Table 59 shows the metadata for presenting school safety accident disaster information. + +**Table 59 – Metadata for presenting school safety accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------|-------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| Cause | Describes the specific reason or situation that led to a school safety accident. | xs:string | M | +| SchoolName | Describes the name of school where school safety accident occurred. | xs:string | M | +| StudentNumber | Describes the number of students enrolled in schools where school safety accidents occurred. | xs:integer | M | +| ControlArea | Describes the area where access is temporarily restricted due to a school safety incident. | xs:string | M | +| Casualty | Describes the amount of human damage resulting from injury or death due to school safety accidents. | xs:integer | M | +| ResponseStatus | Describes the details of follow-up measures officially taken after a school safety accident occurred. | xs:string | M | + +### **9.10 Metadata for presenting other disaster information with human factors** + +This clause addresses the metadata for presenting other disaster information. + +#### **9.10.1 Cultural heritage accident** + +Table 60 shows the metadata for presenting cultural heritage accident disaster information. + +**Table 60 – Metadata for presenting heritage accident disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| CulturalHeritageName | Describes the name of cultural heritage. | xs:string | M | +| SafetyLevel | Describes one of six grades from A (good) to F (immediate action). | xs:string | M | +| CulturalHeritageType | Describes the types of cultural heritage where cultural property accidents occurred, such as national treasures, treasures, and historic sites. | xs:string | M | +| PropertyDamage | Describes the amount of cultural heritage damage due to cultural heritage accident. | xs:integer | M | +| Cause | Describes the causes of cultural heritage accidents. | xs:string | O | + +#### 9.10.2 Wartime disaster + +Table 61 shows the metadata for presenting wartime disaster information. + +**Table 61 – Metadata for presenting wartime disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|------------------------------|-------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| WarSituation | Describes war situation information in a specific time period. | xs:string | M | +| NationallyDesignatedHospital | Describes a hospital designated by the government to manage people's health in the event of a war disaster. | xs:string | M | +| DailyNecessitySupplyPlace | Describes a building or place where daily necessities can be supplied in the event of a war disaster. | xs:string | M | +| EvacuationSite | Describes a place or location to safely escape to in the event of a war disaster. | xs:string | M | +| Casualty | Describes the number of human casualties injured or killed due to war disasters. | xs:integer | O | +| ResponseStatus | Describes the details of follow-up measures officially taken after a war disaster occurred. | xs:string | M | + +#### 9.10.3 Terrorism + +Table 62 shows the metadata for presenting terrorism disaster information. + +**Table 62 – Metadata for presenting terrorism disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------------|----------------------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| TerrorismType | Describes the specific types of terrorism that occurred, such as car explosions, aircraft hijackings, and suicide attacks. | xs:string | M | +| ControlArea | Describes the areas where access is temporarily restricted due to terrorism. | xs:string | M | +| DispatchedPoliceForce | Describes the police force dispatched in the event of a terrorist attack. | xs:integer | O | +| EvacuationSite | Describes a place or location to safely avoid in the event of a terrorist attack. | xs:string | M | +| Casualty | Describes the number of human casualties injured or killed due to terrorist attacks. | xs:integer | M | +| ResponseStatus | Describes the details of follow-up measures officially taken after the terrorist attack occurred. | xs:string | M | +| Cause | Describes the cause of terrorism. | xs:string | O | + +#### **9.10.4 Overseas disaster** + +Table 63 shows the metadata for presenting overseas disaster information. + +**Table 63 – Metadata for presenting overseas disaster information** + +| Element | Description | Data type | Mandatory or Optional | +|-----------------------|------------------------------------------------------------------------------------------------------------|------------------|------------------------------| +| OccurrenceCountryName | Describes the name of country where overseas disaster occurred. | xs:string | M | +| DisasterType | Describes the types of disasters that occur according to the disaster classification system. | xs:string | M | +| DamageRadius | Describes the distance where damage occurred centred on the point where an overseas disaster occurred (m). | xs:integer | M | +| DamageSituation | Describes the damage situation for overseas people. | xs:string | M | +| Casualty | Describes the amount of human damage resulting from injury or death due to overseas disasters. | xs:integer | M | +| PropertyDamage | Describes the amount of property or economic damage caused by an overseas disaster. | xs:integer | O | + +## Bibliography + +- [b-ITU-T X.1303] Recommendation ITU-T X.1303 (2007), *Common alerting protocol (CAP 1.1)*. +- [b-ITU-T FG-DR&NRR] ITU-T Focus Group on Disaster Relief Systems (2014), *Network Resilience and Recovery, Terms and definitions for disaster relief systems, network resilience and recovery*. +- [b-UNISDR] United Nations International Strategy for Disaster Reduction, UNISDR (2009), *2009 UNISDR Terminology on disaster risk reduction*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.780.1-202304-I_PDF-E/045c7af3c493369642487e4d52e15065_img.jpg b/marked/F/T-REC-F.780.1-202304-I_PDF-E/045c7af3c493369642487e4d52e15065_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d4ae7116d820778b8bfe86b068f522e9d8545295 --- /dev/null +++ b/marked/F/T-REC-F.780.1-202304-I_PDF-E/045c7af3c493369642487e4d52e15065_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:4dd8d349352e60f9920f104cf8c585bee4036d0b0aa9c2a85a9fc11d8418f60b +size 42239 diff --git 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sha256:6f3b7e07231c0f3e116c99c493bdda98ecd52313b6735faa6cea23815cf3162b +size 7190 diff --git a/marked/F/T-REC-F.780.2-202304-I_PDF-E/raw.md b/marked/F/T-REC-F.780.2-202304-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..915143c0286a59182c73c5a8418426bde30dbee6 --- /dev/null +++ b/marked/F/T-REC-F.780.2-202304-I_PDF-E/raw.md @@ -0,0 +1,850 @@ + + +# Recommendation **ITU-T F.780.2 (V2) (04/2023)** + +SERIES F: Non-telephone telecommunication services +Multimedia services + +## --- **Accessibility of telehealth services** + +![ITU logo](390120de4fe440c42fea8154fcaad334_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS NON-TELEPHONE TELECOMMUNICATION SERVICES + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multidestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| MULTIMEDIA SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.780.2 + +## Accessibility of telehealth services + +## Summary + +Recommendation ITU-T F.780.2 defines accessibility requirements for technical features to be used and implemented by governments, health-care providers and manufacturers of telehealth platforms to facilitate the access and use of telehealth services by persons with disabilities and specific needs, including older persons with age-related disabilities. + +With the passage of the United Nations Convention on the Rights of Persons with Disabilities in 2006, and its ratification by numerous countries, persons with disabilities have the right to enjoy the highest attainable standard of health without discrimination on the basis of disability. Countries need to take all appropriate measures to ensure access to health services for persons with disabilities. + +During the COVID-19 pandemic, the use of telehealth services increased substantially in many countries and telehealth has become a basic need for the general population, especially for those in quarantine, enabling patients in real time through contact with health-care providers to access advice. However, due to the lack of global and comprehensive standards and guidelines for accessibility of telehealth services, many persons with disabilities experience difficulties accessing and using such services and are often forgotten. This Recommendation summarizes and defines those requirements and features that industries can implement to ensure accessible provision of telehealth services. + +Technical requirements defined in this Recommendation are based on comprehensive feedback collected from civil society on barriers that persons with disabilities experience when accessing and using telehealth services, as well as on the feedback from industry. This Recommendation was developed collaboratively by the World Health Organization (WHO) and ITU. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|--------------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.780.2 | 2022-03-16 | 16 | 11.1002/1000/14967 | +| 2.0 | ITU-T F.780.2 (V2) | 2023-04-29 | 16 | 11.1002/1000/15547 | + +## Keywords + +Accessibility, disability, health services, telehealth. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2023 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +###### Page + +| | | | +|------|----------------------------------------------------------------------------------------------|----| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| 3.1 | Terms defined elsewhere ..... | 1 | +| 3.2 | Terms defined in this Recommendation ..... | 2 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | Conventions ..... | 3 | +| 6 | Background..... | 3 | +| 7 | Challenges that persons with disabilities face in a telehealth environment..... | 4 | +| 7.1 | Persons with vision impairment and blindness..... | 4 | +| 7.2 | Persons who are deaf or hard of hearing..... | 4 | +| 7.3 | Persons with speech difficulties ..... | 5 | +| 7.4 | Persons with mobility impairments ..... | 5 | +| 7.5 | Persons with mental health conditions and psychosocial disabilities ..... | 5 | +| 7.6 | Persons with developmental and intellectual disabilities..... | 5 | +| 7.7 | Persons with learning disabilities ..... | 6 | +| 8 | General technical requirements ..... | 6 | +| 8.1 | Requirements for persons with vision impairment and blindness..... | 6 | +| 8.2 | Requirements for deaf and hard of hearing persons..... | 7 | +| 8.3 | Requirements for persons with speech difficulties..... | 8 | +| 8.4 | Requirements for persons with mobility issues..... | 9 | +| 8.5 | Requirements for persons with mental health conditions and psychosocial disabilities ..... | 9 | +| 8.6 | Requirements for persons with developmental and intellectual disabilities... | 10 | +| 8.7 | Requirements for persons with learning disabilities ..... | 11 | +| 9 | Technical requirements during the planning phase..... | 11 | +| 10 | Security ..... | 12 | +| 10.1 | Datagram transport layer security (DTLS) ..... | 12 | +| 10.2 | Secure real-time transport protocol (SRTP) ..... | 12 | +| 10.3 | Encryption..... | 12 | +| | Annex A – Electromagnetic compatibility for accessible telehealth ..... | 13 | +| | Appendix I – Background information on accessibility of telehealth and e-health services ... | 15 | +| I.1 | Introduction..... | 15 | +| I.2 | How do people consume digital information? ..... | 19 | +| I.3 | Accessibility guidelines for telehealth and e-health applications..... | 20 | +| I.4 | Methodology and development process..... | 23 | +| I.5 | Important resources ..... | 24 | +| | Bibliography ..... | 26 | + +# Introduction + +The World Health Organization (WHO) defines telehealth as the "delivery of health-care services, where patients and providers are separated by distance. Telehealth uses information communication technology for the exchange of information for the diagnosis and treatment of diseases and injuries, research and evaluation, and for the continuing education of health professionals" [b-WHO-1]. Telehealth is a service that has been widely applied in many countries for decades. During the COVID-19 pandemic, the use of telehealth services increased substantially in many countries, becoming a basic need for the general population and enabling people to contact health-care providers from home in real time. As such, telehealth contributes to achieving universal health coverage in countries by improving access to quality and cost-effective health services for patients regardless of their setting. It is particularly valuable for those who live in remote areas and for marginalized populations. + +While telehealth provides the means for an equitable health service provision, in reality many persons with disabilities experience difficulties and challenges accessing and using telehealth services. There is more and more evidence that especially in low- and middle-income countries persons with disabilities cannot benefit from telehealth services due to highly inaccessible formats of delivery. For example, very often telehealth platforms are not compatible with devices such as screen readers that facilitate people with vision impairment to access information, or the lack of captioning or volume control in video conferencing impedes persons who are deaf or hard of hearing to interact with health professionals virtually. It is, therefore, critical to upscale efforts to address the "digital divide" faced by persons with disabilities, in order to ensure equitable access to telehealth services and address any structural inequalities. + +This Recommendation provides a list of technical requirements that telehealth platforms must have to ensure accessible telehealth-service provision for persons with disabilities. All requirements are based on the best available evidence, as well as comprehensive feedback and input collected from civil society and industry. + +Specific requirements are provided for people with different types of impairments: + +- 1) Requirements 1 to 6 for persons with vision impairment and blindness; +- 2) Requirements 7 to 11 for deaf and hard of hearing persons; +- 3) Requirement 12 for persons with speech difficulties; +- 4) Requirements 13 to 15 for persons with mobility impairments; +- 5) Requirements 16 to 20 for persons with mental health conditions and psychosocial disabilities; +- 6) Requirements 21 to 23 for persons with developmental and intellectual disabilities; +- 7) Requirements 24 and 25 for persons with learning disabilities. + +This Recommendation is a joint global standard of WHO and the International Telecommunication Union (ITU) that is published as technically aligned texts. + +The requirements in this Recommendation are recommended for adoption by Member States as regulations or legislation and should also be voluntarily implemented by health-care professionals and manufacturers. + +# Recommendation ITU-T F.780.2 + +## Accessibility of telehealth services + +# 1 Scope + +This Recommendation is a WHO–ITU global standard for the accessibility of telehealth services which outlines some of the most common requirements for accessible telehealth services. More specifically, this Recommendation includes requirements on concrete accessibility features that health-care providers and manufacturers of telehealth platforms need to ensure when delivering telehealth services. The standard can be used and implemented by governments, manufacturers of telehealth platforms and health-care providers. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T K.127] Recommendation ITU-T K.127 (2017), *Immunity requirements for telecommunication equipment in close proximity use of wireless devices*. +- [ITU-T K.136] Recommendation ITU-T K.136 (2022), *Electromagnetic compatibility requirements for radio telecommunication equipment*. +- [ITU-T K.137] Recommendation ITU-T K.137 (2022), *Electromagnetic compatibility requirements and measurement methods for wireline telecommunication network equipment*. +- [IEC 60601-1-2] IEC 60601-1-2:2014, *Medical electrical equipment – Part 1-2: General requirements for basic safety and essential performance – Collateral standard: Electromagnetic disturbances – Requirements and tests*. +- [IEC 61000-2-2] IEC 61000-2-2:2002, *Electromagnetic compatibility (EMC) – Part 2-2: Environment – Compatibility levels for low-frequency conducted disturbances and signalling in public low-voltage power supply systems*. +- [NIST FIPS 197] National Institute of Standards and Technology NIST FIPS 197 (2001), *Advanced Encryption Standard (AES)*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 telehealth** [b-WHO-1]: Delivery of healthcare services, where patients and providers are separated by distance. Telehealth uses information and communication technologies (ICT) for the exchange of information for the diagnosis and treatment of diseases and injuries, research and evaluation, and for the continuing education of health professionals. + +**3.1.2 assistive technology** [b-ISO 9999]: Any product (including devices, equipment, instruments and software), especially produced or generally available, used by or for persons with disability for + +participation; to protect, support, train, measure or substitute for body functions/structures and activities; or to prevent impairments, activity limitations or participation restrictions. + +**3.1.3 accessibility** [b-ITU-T F.791]: The degree to which a product, device, service or environment (virtual or real) is available to as many people as possible. + +**3.1.4 accessibility feature** [b-ITU-T F.791]: An additional content component that is intended to assist people hindered in their ability to perceive an aspect of the main content. + +**3.1.5 electromagnetic compatibility** [ITU-T K.127]: Ability of equipment to function satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbances to anything in that environment. + +**3.1.6 electromagnetic interference** [b-ITU RR]: The effect of unwanted energy due to one or a combination of emissions, radiations, or inductions upon reception in a radiocommunication system, manifested by any performance degradation, misinterpretation or loss of information which could be extracted in the absence of such unwanted energy. + +## **3.2 Terms defined in this Recommendation** + +This Recommendation defines the following term: + +**3.2.1 disability**: The result from the interaction between health conditions or impairments that a person experiences and environmental barriers that may hinder the person's full and effective participation in society on an equal basis with others. + +NOTE – Adapted from [b-WHO-2] and [b-ITU-T F.791]. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|---------|--------------------------------------------| +| AES | Advanced Encryption Standard | +| AI | Artificial Intelligence | +| ASR | Automated Speech Recognition | +| ATAG | Authoring Tool Accessibility Guidelines | +| DPO | Disabled Persons Organization | +| DTLS | Datagram Transport Layer Security | +| EHR | Electronic Health Record | +| EMC | Electromagnetic Compatibility | +| EMI | Electromagnetic Interference | +| HTML | Hypertext Markup Language | +| ICT | Information and Communication Technologies | +| LMS | Learning Management System | +| mHealth | Mobile Health | +| RTP | Real-Time Transport Protocol | +| SMS | Short Message Service | +| SRTP | Secure Real-Time Transport Protocol | +| TTS | Text-to-speech | +| UHC | Universal Health Coverage | + +| | | +|--------|--------------------------------------| +| VRI | Video Remote Interpretation | +| W3C | World Wide Web Consortium (W3C) | +| WCAG | Web Content Accessibility Guidelines | +| WebRTC | Web Real Time Communication | + +# 5 Conventions + +None. + +# 6 Background + +The World Health Organization (WHO) defines telehealth as the "delivery of healthcare services, where patients and providers are separated by distance. Telehealth uses ICT for the exchange of information for the diagnosis and treatment of diseases and injuries, research and evaluation, and for the continuing education of health professionals." [b-WHO-1]. Telehealth can contribute to achieving universal health coverage in countries by improving access to quality and cost-effective health services for patients regardless of their setting. It is particularly valuable for those who live in remote areas, for vulnerable groups and ageing populations. + +Telehealth is a service that has been introduced and used in many countries for decades. With the rapid evolution of technology, most families have at least one digital device that can provide the means for communication between a patient and a health-care provider. During the COVID-19 pandemic, however, the use of telehealth services increased substantially in many countries. Telehealth has become a basic need for the general population, especially for those in quarantine, enabling patients in real time through contact with health-care providers to access advice on their health problems. In fact, a recent WHO report showed that telehealth is the most common modality adopted by countries for service provision during the pandemic [b-WHO-3]. The report also shows that there is a trend of increasing utilization of telehealth as income level increases, although even among low-income countries, 42% of those with service disruptions during the COVID-19 crisis report utilizing this technology. However, due to the lack of standards and guidelines for access to telehealth services, many persons with disabilities and specific needs are experiencing difficulties and challenges in accessing and using such services. Their needs are often forgotten and not accommodated. + +During the initial phase of the COVID-19 pandemic, the United Nations Under-Secretary-General convened an emergency time-bound working group on disability inclusive health response and recovery with the participation of several organizations, including the Economic and Social Commission for Western Asia, the Executive Office of the Secretary-General, the Office of the High Commission for Human Rights, the UN Development Programme, the UN Entity for Gender Equality and the Empowerment of Women, International Disability Alliance, International Disability and Development Consortium, International Telecommunication Union (ITU), and WHO. One of the main outcomes of this working group was the development of a terms of reference document outlining the importance of telehealth and e-health guidance for persons with disabilities (Appendix I). These terms of reference served as a basis for the development of the current standard. The methodology and development process of the standard are described in clause I.4. + +Most of the common challenges faced by persons with disabilities can be addressed through standardization and regulation. The development of standards for telehealth is an important and valuable process to help ensure accessible, effective and safe delivery of health care. There are examples of existing guidelines in different countries. For example, the American Telemedicine Association (ATA) has created practice guidelines that are being adopted by numerous professionals [b-Krupinski]. The Government of New South Wales, Australia, has adopted a telehealth framework and implementation strategy for the 2016-2021 period [b-NSW]. The WCAGs are universal + +guidelines used in many countries and practices [b-W3C WAI]. However, none of these guidelines and standards cover all the areas of accessibility which end-users with disability might experience. This current standard aims to fill this gap by providing a comprehensive set of requirements on concrete accessibility features that health-care providers and manufacturers of telehealth platforms can implement when delivering telehealth services. + +# **7 Challenges that persons with disabilities face in a telehealth environment** + +This clause outlines common challenges that persons with disabilities experience when accessing and using telehealth services. The clause is divided into six subclauses, outlining challenges that persons with vision impairment and blindness, persons who are deaf or hard of hearing, persons with speech difficulties, persons with mobility issues, persons with mental health conditions and psychosocial disabilities, and persons with developmental, intellectual or learning disabilities experience. Some of the challenges may overlap across different groups. + +## **7.1 Persons with vision impairment and blindness** + +- Telehealth platforms are often not compatible with some specific assistive devices such as screen readers or Braille keyboards. +- Scanned documents, text images, infographics or diagrams have no alternative text. +- Background music interferes with audio voice-over. +- Colour contrast and screen magnification are also important elements of accessible virtual visits that, if missing, do not allow people to view images and text on the screen, also reducing access to their own medical records and lab results. +- The health-care provider is not sensitized on the specific needs of people with vision impairment. +- A lack of a fixed phone line means that there are fewer options for people with vision impairment when a digital platform is not accessible. +- Software providers of telehealth apps may not consider accessibility for persons with disabilities. +- Smartphones tend to use touch screens which are not always as navigable as phones with larger buttons. + +## **7.2 Persons who are deaf or hard of hearing** + +- Unstable connection over the phone presents barriers. +- Inadequate captioning or volume control in video conferencing. +- Unstable Internet interferes with the video signal (e.g., video/audio delay) making lip-reading and sign language less clear. +- Text messaging can be a solution when the video or audio are not working well, but it is often not available as an option in telehealth platforms. +- Background music during videos and background noise during consultations presents a barrier for people who are hard of hearing. +- Small screens of smartphones can make lip-reading and sign language less clear. +- Lack of speech-to-text generators. +- Bad signal-to-noise ratio does not allow for good communication. +- When captioning is available, no speech-to-text reporters and real-time captioners are used. +- In the context of COVID-19, wearing masks during telehealth services can impede people relying on lip-reading to communicate. + +- When the audio signal is not good, lack of an option to use a microphone to improve audio. +- Lack of options for scheduling sessions through text or email when audio phone systems are not accessible. +- No option to include accommodation requests in an online platform for scheduling. +- The size on screen for sign language interpretation is not appropriate. +- Lack of hearing loop on phone available. + +NOTE – If a user decides to use a phone to participate in a telehealth session, it is the responsibility of the user to select a hearing-aid-compatible phone. + +## **7.3 Persons with speech difficulties** + +- Voice synthesizers and text-to-speech generators are not available on telehealth platforms. +- Standard timetabling does not accommodate people who need more time for communication. +- Pace and tone and rhythm of voice being used when synthesizing might be a challenge. +- Telehealth services sometimes offer only phone numbers as the way to communicate with health-care providers. +- Unstable or poor audio quality can be a challenge for people who have speech difficulties who might be required to repeat the same sentences many times, causing fatigue and deteriorating speech. +- Services and platforms which do not allow video or have poor video quality limit the possibility to rely on non-verbal communication. + +## **7.4 Persons with mobility impairments** + +- Platform's icons and navigation system are too restrictive in size or not structured in a way that is easy for people with fine motor movement difficulties to use (e.g., requiring people to double-click instead of single-click). +- Insufficient time limits to respond or to complete tasks, such as to fill out online forms. + +## **7.5 Persons with mental health conditions and psychosocial disabilities** + +- Unexpected, irrelevant and inappropriate content can be upsetting. +- Sufficient information is not provided on how the telehealth service ensures safety, privacy, and security, including the role of the user in achieving these goals, which can foster negative feelings and discourage usage. +- Sufficient guidance is not provided on how to use the telehealth service. +- Difficulty using complicated and unnecessarily effortful user interfaces on the platform and troubleshooting or overcoming system errors. +- Difficulty trusting resources with poor information quality and design. + +## **7.6 Persons with developmental and intellectual disabilities** + +- Use of technical language by the provider or administrative personnel may be difficult to understand and lead to misinterpretation. +- Health information in the platforms is not simple and accessible, key documents are not in easy-to-read formats. +- People who provide personal support to persons with intellectual disabilities are not included in the conversation. +- Simple educational material on how to use telehealth services is not available. + +## 7.7 Persons with learning disabilities + +- Text and documents on online platforms are sometimes difficult to follow for persons with dyslexia. For example, underlining and italics can make words 'run together', or flow charts, illustrations and diagrams can be too difficult to follow and understand. +- Complex navigation mechanisms and page layouts are difficult to understand and use. +- Complex sentences are difficult to read and long passages of text difficult to follow. +- Moving, blinking or flickering content and background audio cannot be turned off. + +# 8 General technical requirements + +This clause describes requirements on concrete accessibility features that health-care providers and manufacturers of telehealth platforms need to ensure when delivering telehealth services. The requirements are based on the challenges identified and included in clause 7. Some of the requirements might overlap across different groups of persons with disabilities. + +It is also recommended that telehealth services in general, and accessible telehealth services in particular, provide proper electromagnetic compatibility (EMC) as well as guidance on its application during their telehealth sessions, as described in Annex A. + +## 8.1 Requirements for persons with vision impairment and blindness + +- **Requirement 1:** The functioning of the telehealth platform should be compatible with screen readers or assistive devices such as Braille keyboards, removing barriers for people who are blind or visually impaired. + - Screen readers are considered one of the most basic accessibility tools for people with vision impairment, enabling them to "see" their screen. The assistive device communicates what a person without a visual impairment can see through non-visual methods such as sound icons and text-to-speech. The screen reader can also translate the information on the screen and display it in Braille. This means users can navigate the screen, type, read and edit text more efficiently and accurately. It is considered the most basic accessibility feature a platform can have for people with vision impairment. +- **Requirement 2:** Colour contrast and screen magnification shall be available to allow people to view images and text on the screen during virtual visits. + - Colour contrast means that there is enough contrast between the text or image and its background for people with vision impairments to be able to read the text or see the image even if they cannot access all the colours. The Web Content Accessibility Guidelines (WCAGs) provide specific guidance on the ratios of contrast. + +Screen magnification enlarges text and images on the screen up to 20 times their display size, which makes the content more visible for people with poor vision. The magnification follows the user's activity on the screen from typing to moving their cursor. The size of the cursor can also be increased which enables it to be found more easily on the screen. + - Alternative text needs to be provided for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language. The WCAGs provide specific guidance on how alt text can be added. + - The same applies also for telehealth patient portals that store online medical charts, images and messages that allow patients to access their medical history and lab results. +- **Requirement 3:** Services using telephone calls shall be accessible for a person with vision impairment who cannot access the digital platform (even though many users may not have a fixed line at home). + +- Services must be accessible to people with vision impairment. Thus, if the digital platform is inaccessible, telephone calls are another suitable option. Using a phone can present some challenges but certain laws such as the Telecommunications Act of 1996 in the United States of America ensure that all telephone devices are accessible to people with vision impairment. + +– **Requirement 4:** Telehealth apps should avoid processes that require downloading specific software onto devices, specific platforms, different passwords and variable software development or support when possible. + +- Telehealth apps that require downloading place further barriers for people with vision impairment. People with vision impairment already face more challenges when accessing products and navigating telehealth platforms. The steps in the process to getting the service they need be the bare minimum. + +– **Requirement 5:** Videos included on telehealth platforms should not include background music as it makes it difficult to listen to relevant information. + +- People with vision impairment depend on information being communicated through sound, such as through their screen reader, or touch, such as through their Braille keyboard. Background noise of any kind can make it hard for users with vision impairment to focus on the relevant information that is being conveyed as they might have no other means of accessing the information unlike people without vision impairment. + +– **Requirement 6:** Ambiguous wording and inaccurate descriptions in videos should be avoided. + +- People with vision impairment depend on descriptions when they are not able to visualize content such as videos and images. Ambiguous or inaccurate wording can be confusing or convey incorrect information. It is critical that the descriptions provide the same information with or without the visual aspect. + +## 8.2 Requirements for deaf and hard of hearing persons + +– **Requirement 7:** Video conferencing shall provide captioning and a monitored chat box that has volume control provisions along separate windows. + +- Real-time captioning allows persons who are deaf and hard of hearing to access video and spoken content. This is especially important for persons who are hard of hearing if the audio is not clear and vital for persons who are deaf and who need captioning. If there is a background noise, all participants may not understand what is being said. This also solves the problem of speakers mumbling or having strong accents. Captioning is vitally important for all if the speaker is not visible because without visual representation of the speaker, there is no possibility of lip-reading. +- It is recommended to use professional human captioners, preferably specialized in medical/health related captioning, and only use automated speech recognition (ASR) captioning when the former is not possible, as it is still not accurate enough regarding accented speech and extraneous noise. If ASR is used, it needs monitoring for accuracy by the health-care provider to avoid miscommunication. A chat box is essential to recap diagnosis and treatment plans; it is also required to type correct wording if ASR fails to pick up voice correctly for accurate real-time captioning. +- Use of ASR in telehealth appointments: Some video conferencing platforms already offer an automated captioning feature which is often based on artificial intelligence (AI) that can recognize continuous speech using speech-to-text software to deliver live captioning. AI, as part of the speech recognition process, will try to match what it recognizes as speech against a vocabulary list of terms. ASR and their accuracy and usefulness also depend on Wi-Fi, quality of audio in the call, speaker voice, accent and acoustics. + +- It is advisable for the accuracy of medical treatment prescribed that professionals providing captioning are supporting communication. If this is not possible, health-care professionals need to monitor text output and provide correct information in the chat box. +- For mental health assessments, ASR apps shall not be used as they can provide confusing information. + +– **Requirement 8:** Text messaging shall be included as a service to be used when the video or audio are not working well along with the chat box. Text messaging shall be set up to allow text communication to and from patients. + +- For persons who are deaf or hard of hearing, the use of text messaging when video or audio are not accessible is important. Most people already use and understand how text messaging works, as most are users of smartphones and familiar with this technology. This will help users of telehealth services to communicate with their health providers and the other way around. + +– **Requirement 9:** Remote sign language interpretation or a video remote interpretation (VRI) system should be implemented and made available to persons who are deaf and hard of hearing as a standard part of telehealth services. + +- A VRI client needs to call the VRI service and start the VRI session. It is assumed that the health service provider has a communication environment capable of receiving the communication requests (voice/video invitation) from the VRI agent. The VRI client terminal must be able to display and play two sets of audio and video signals: the VRI agent and the medical personnel. Also, it is desirable that the image of the VRI agent is at least as large as that of the medical personnel so that the sign language can be easily read. As not all hard of hearing and deaf people use sign language, a speech-to-text software should be available as an option on the platform. + +– **Requirement 10:** Videos on telehealth platforms should include clear subtitles (easy to read and large font size) and avoid background music as it makes it difficult to listen to relevant information. + +Guidance on developing subtitles is available elsewhere, for example in [b-ISO/IEC 20071-23]. + +– **Requirement 11:** The screen used for telehealth should be large enough for lip-reading.1 + +- Lip-reading allows someone to better understand what is being verbally communicated. This is done through observing the movement the speaker's lips as well as their facial expressions and body language, especially when using a hearing aid and in noisy situations. Therefore, to visualize the movements of someone's face, the screen must be large enough to provide sufficient detail. + +## 8.3 Requirements for persons with speech difficulties + +– **Requirement 12:** Platforms should include voice synthesizers and/or text-to-speech generators which can translate what people with speech impairment say. + +- Adaptive technology option should be available for people with speech difficulties. If those people cannot use their voice or their words are garbled, they can benefit from using a text-to-speech app or feature on the telehealth platform or a voice synthesizer that, using software technology, will communicate what they are saying. Text-to-speech + +1 Whenever the telehealth service is provided from a healthcare facility to the house of the user, quality issues that might appear on the user's side such as sound quality, use of quality microphone or headset, or control of screen size are outside the scope of this Recommendation. The implementer of the telehealth service might provide advice to the user in this regard. When the telehealth service is provided from a healthcare facility to another facility or clinic, then the platform provider is responsible for the quality of the service at the user's end. + +(TTS) is a type of assistive technology that reads digital text aloud. With a click of a button or the touch of a finger, TTS can take words or sentences on a computer or other digital device and convert them into audio. A voice synthesizer is a type of TTS that allows a computer or other machine to read words out loud in a real or simulated voice played through a loudspeaker. + +## 8.4 Requirements for persons with mobility issues + +- **Requirement 13:** The controls of virtual visit applications should not be too restrictive in size, so that users with physical challenges will not have difficulty using the fine motor movements required to operate the platform. + - People with mobility issues find it difficult to control the small muscles in their hands. Therefore, activities such as controlling the cursor, writing or typing may be challenging. Larger controls of virtual visit applications will allow people with mobility issues to navigate the telehealth platform more easily. +- **Requirement 14:** The telehealth platform shall not explicitly require fine motor coordination (e.g., double-clicking which is difficult instead of single-clicking). + - People with mobility issues find it difficult to control the small muscles in their hand. Therefore, an activity such as double-clicking becomes a barrier to these users and renders activities on the telehealth platform inaccessible. +- **Requirement 15:** The telehealth platform should avoid scrolling or using menu options to access information as much as possible. + - People with mobility issues find it difficult to control the small muscles in their hand. Therefore, controlling the cursor or using specific keys to navigate the screen become more challenging and mean that users may not be able to access all the information they need. + - Sufficient time needs to be provided to people with mobility issues to respond or to complete tasks, such as to fill out online forms. + +## 8.5 Requirements for persons with mental health conditions and psychosocial disabilities + +- **Requirement 16:** The telehealth platform should avoid unexpected, irrelevant and inappropriate content that can be upsetting and trigger negative feelings and reactions. + - People with mental health conditions and psychosocial disabilities may be negatively affected and impacted by exposure to personally sensitive content. If anticipated, it is important to avoid any such information. If it is necessary to convey personally sensitive content, there must be a trigger warning to make users aware of the potentially upsetting content ahead of time. Users should also be provided with a choice in information format, such as text instead of images or video with audio, that conveys meaning in a less emotionally immersive way. +- **Requirement 17:** The telehealth platform shall explain the measures implemented to ensure that usage and data remain safe, private and secure in an effort to avoid negative thinking regarding the possibility of related undesirable consequences. + - Ensuring safety, privacy and security remains a critical challenge for some telehealth platforms. Unfortunately, persons with mental health conditions and psychosocial disabilities may also feel uncomfortable using telehealth platforms due to a fear of undesirable consequences such as a data breach, problematic use and threats to privacy. It is crucial that telehealth services clearly state their stance on the safety, privacy and security of personally identifiable information that is being shared online and misused. This will help make persons with mental health conditions and psychosocial disabilities more comfortable when considering and using telehealth services. + +- **Requirement 18:** The telehealth platform should avoid using complicated user interfaces and language that is difficult to understand and providing inadequate guidance on how to complete tasks. + - Complicated and difficult to understand user interfaces can create barriers for persons with mental health conditions and psychosocial disabilities. The struggle to navigate the platform may be upsetting and cause users to avoid using the telehealth service. + - The telehealth platforms should use simple language and be easy to use and navigate. Platforms should also provide adequate support to help users quickly recover from user-generated errors. This increases the accessibility of the service to people with mental health disorders who may already be apprehensive about telehealth. +- **Requirement 19:** The telehealth platform should avoid unnecessarily effortful tasks and allowing malfunctioning features to persist. + - The telehealth platform should be simple and easy to use as intended. This increases the accessibility of the service to persons with mental health conditions and psychosocial disabilities who may already be apprehensive about telehealth. Increasing the ease of use by minimizing the mental effort to access information is critical. However, the effort to perform a task must allow for adequate deliberation. + - Malfunctioning platforms can trigger catastrophic thinking and a reduced willingness to troubleshoot. The telehealth platform should ensure that the platform is constantly monitored for system errors and that identified errors are swiftly communicated to users, when necessary, and resolved. +- **Requirement 20:** The telehealth platform should avoid presenting low-quality information as this contributes to distrust. + - Information on telehealth platforms must be up-to-date, relevant, credibly sourced, balanced and easily perceived and understood by persons with mental health conditions and psychosocial disabilities. Using an appropriate writing style and tone, easy to read language, pictograms and sound files can help ensure that the content is clear and accessible. Platforms that feature a simple information structure, layout and design can also be useful in achieving this aim. + +## 8.6 Requirements for persons with developmental and intellectual disabilities + +- **Requirement 21:** Key documents and information provided by health-care providers should be provided in accessible formats, such as in easy read formats. + - Persons with intellectual disabilities experience limitations in adaptive behaviour such as conceptual skills which include language, literacy and number concepts. Information needs to thus be made easier to read and process. This means avoiding jargon, complicated words, abbreviations or symbols. It is good to summarize the most important points that need to be conveyed. Complex information should be simplified by explaining it using examples from everyday life. It is good to break information down into smaller sections using short sentences, bullet points and sub-headings. The text needs to be a minimum of 14 pt in size with extra space between the lines. Including pictures that illustrate the content of the text can also help. This easy-to-read text will be more accessible for everyone, even for persons without intellectual disabilities. +- **Requirement 22:** The telehealth platforms shall allow for more than two people to participate in a meeting, e.g., people who provide personal support to persons with developmental and intellectual disabilities should be able to attend their meetings with health-care providers. + - People who provide personal support promote well-being and enhance individual functioning for persons with intellectual disabilities. This includes making information easier to understand and ensuring it is communicated directly to persons with intellectual + +disabilities. Communication difficulties between persons with intellectual difficulties and health-care providers may lead to inaccuracies in the understanding or reporting of concerns, symptoms and history. Personal support can be required to access and participate in meetings and follow through on the recommendations. + +- **Requirement 23:** Simple educational material on how to use telehealth services should be made available on the telehealth platform. + - People with intellectual disabilities may have trouble using telehealth services due to the complexity of the systems or lack of digital literacy. Educational material that is easy to read allows persons with intellectual disabilities to use the platform. The material should explain what telehealth is, how to schedule telehealth, how to prepare for telehealth and how to participate in telehealth. This material could also come in the form of videos using both images and language that are simple and easy to understand. + +## 8.7 Requirements for persons with learning disabilities + +- **Requirement 24:** The layout of the text, instructions, documents and worksheets on the telehealth platform should be easily accessible for persons with dyslexia and other learning disabilities. + - Persons with dyslexia can have difficulties following the text or graphs if these are not easily accessible. For example, the use of underlining or italics may make words 'run together', whereas bold text for titles and sub-headings or to draw attention to important information or key vocabulary is very important. Text boxes or borders for headings, as well as highlighting important text, is instrumental. Including logical and easy-to-follow flow charts, illustrations and diagrams to break down large sections of text or to demonstrate a particular procedure is also important. Keeping paragraphs short and sentences simple is also helpful. More information on potential solutions can be found in the WCAG. +- **Requirement 25:** The text content should be made readable and understandable, and users need to be provided enough time to read and use content. + - Some persons with learning disabilities experience great difficulty in recognizing written words, or inferring the meaning of a word or phrase from context, especially when the word or phrase is used in an unusual way or has been given a specialized meaning. Therefore, the text included on the platform should be presented in a readable way, and if needed, specific definitions or the expanded forms of acronyms or abbreviations should be available. + - Many persons with learning disabilities need more time to complete tasks than the majority of users: they may take longer to physically respond, to read things, to find things or they may be accessing content through an assistive technology that requires more time. Therefore, if certain tasks are to be completed through the platform, enough time should be allocated, or if health-care providers request patients to undertake tasks, they should provide sufficient time. + - More information and concrete solutions can be found in W3C Accessibility standards. + +# 9 Technical requirements during the planning phase + +The health-care-service providers and manufacturers of telehealth platforms should develop a system to facilitate administrative advance planning for persons with disabilities. This system should provide easy to use communication techniques and ensure that these are in place so that healthcare professionals can anticipate users' specific needs when setting up telehealth appointments. The administrators should: + +- Provide accessible ways and means to make the initial appointment via email, SMS and online booking system. +- Allocate enough time for telehealth appointments with persons with disabilities and specific needs. +- Develop robust and transparent registration processes to identify if an individual has any communication/information needs relating to a disability or sensory loss: + - Record these needs in a clear, unambiguous and standardized way – electronically or using paper records (administrative systems or documents). + - Ensure recorded needs are 'highly visible' by means of highlights, alerts or flagging up in the system. Whenever a service user's record is accessed by other staff members, they should be prompted to take action to communicate appropriately with the service user. + - Share information about a service user's communication needs as part of existing data sharing processes, after obtaining patient permission and in accordance with existing information governance frameworks. + - Take steps to ensure the service user receives information they can access and are able to understand, because it has been delivered in the way that was requested. +- Brief training/sensitization of health-care providers on how to use telehealth services when communicating with persons with disabilities should be provided. This can be done through a short tutorial included on the telehealth platform or through other means. For example, health-care providers should know to use a microphone close to their mouth, e.g., headset with close talk microphone, or microphone alone; speak slowly and articulate, and reformulate sentences with simple words. + +# 10 Security + +Consistent with the guidelines on web-based remote sign language interpretation or VRI systems in [b-FSTP.ACC-WebVRI], real-time communication through the web (WebRTC) must be protected according to the WebRTC standards described below. + +## 10.1 Datagram transport layer security (DTLS) + +Datagram transport layer security (DTLS) is a communication protocol designed to protect the privacy of data and prevent eavesdropping and tampering, as defined by [b-IETF RFC 4347] and [b-IETF RFC 6347]. + +## 10.2 Secure real-time transport protocol (SRTP) + +Secure real-time transport protocol (SRTP) is an encrypted real-time transport protocol (RTP) that is used to send and receive encrypted audio and video. SRTP is defined in [b-IETF RFC 3711]. + +## 10.3 Encryption + +In the case of encryption, web real-time communication (WebRTC) uses the standard encryption algorithm, which is widely used internationally. Accordingly, advanced encryption standard (AES) shall be used [NIST FIPS 197]. + +# Annex A + +## Electromagnetic compatibility for accessible telehealth + +(This annex forms a normative part of this Recommendation.) + +Electromagnetic compatibility (EMC) is the ability of electrical equipment and systems to function acceptably in their electromagnetic environment, by limiting the unintentional generation, propagation and reception of electromagnetic energy, which may cause unwanted effects such as electromagnetic interference (EMI) or even physical damage to operational equipment [IEC 61000-2-2]. + +Since much, if not most, of telehealth requires information communication technology (ICT) and electromagnetic equipment, EMC becomes an essential part of telehealth for its successful and effective deployment. This is especially true for accessible telehealth, as it is expected that parties under telehealth care must involve persons with disabilities and specific needs, and that the party will be extremely vulnerable if the requirements of EMC are not correctly met. This is also true in the case of home telehealth, where the patient receives service in their home. + +Therefore, the practitioner of telehealth is expected to develop an appropriate EMC management plan that meets the requirements of relevant standards that will support the proper use of ICT in telehealth. This annex gives some guidelines on EMC for accessible telehealth. + +The telehealth provider is required to be aware of the needs of EMC and provide appropriate set-ups according to the established relevant standards, in the following ways: + +For the case of medical equipment, it is expected that [IEC 60601-1-2] has been consulted and implemented. + +To ensure a reliable telehealth service, providers should pay attention to the EMC aspects and verify that the applicable relevant standards are applied. Examples of applicable standards are: + +- For medical devices: + - IEC 60601-1-2, "Medical electrical equipment – Part 1–2: General requirements for basic safety and essential performance – Collateral standard: Electromagnetic disturbances – Requirements and tests." + - ETSI EN 301 489-27, "ElectroMagnetic Compatibility (EMC) standard for radio equipment and services; Part 27: Specific conditions for Ultra Low Power Active Medical Implants (ULP-AMI) and related peripheral devices (ULP-AMI-P) operating in the 402 MHz to 405 MHz bands. " + - ETSI EN 301 489-29, "ElectroMagnetic Compatibility (EMC) standard for radio equipment and services; Part 29: Specific conditions for Medical Data Service Devices (MEDS) operating in the 401 MHz to 402 MHz and 405 MHz to 406 MHz bands. " + - ETSI EN 301 489-31, "ElectroMagnetic Compatibility (EMC) standard for radio equipment and services; Part 31: Specific conditions for equipment in the 9 kHz to 315 kHz band for Ultra Low Power Active Medical Implants (ULP-AMI) and related peripheral devices (ULP-AMI-P). " + - ETSI EN 301 489-35, "ElectroMagnetic Compatibility (EMC) standard for radio equipment and services; Part 35: Specific requirements for Low Power Active Medical Implants (LP-AMI) operating in the 2 483.5 MHz to 2 500 MHz bands. " +- For the network to interconnect the devices: + - ITU-T K.74, "Electromagnetic compatibility, resistibility and safety requirements for home network devices". + +- ITU-T K.92, "Conducted and radiated electromagnetic environment in home networking" +- ITU-T K.93, "Immunity of home network devices to electromagnetic disturbances" +- ITU-T K.116, "Electromagnetic compatibility requirements and test methods for radio telecommunication terminal equipment" +- ITU-T K.127, "Immunity requirements for telecommunication equipment in close proximity use of wireless devices" +- ITU-T K.136, "Electromagnetic compatibility requirements for radio telecommunication equipment" +- ITU-T K.137, "Electromagnetic compatibility requirements and measurement methods for wireline telecommunication network equipment" + +# Appendix I + +## Background information on accessibility of telehealth and e-health services + +(This appendix does not form an integral part of this Recommendation.) + +This appendix was developed as terms of reference for the preparation of this Recommendation and its sole purpose is to describe some key terms such as telehealth, digital information, e-health, m-health and accessibility, and to provide a list of resources. + +### I.1 Introduction + +E-health has been a priority for WHO since 2005, when World Health Assembly resolution WHA58.28 was adopted: "e-health is the cost-effective and secure use of information communication technologies (ICT) in support of health and health related fields, including health-care services, health surveillance, health literature, and health education, knowledge and research". + +By e-health we are referring to the use of ICT for health and health related fields. The health sector, like every other sector of the economy, is being digitally transformed. Technologies have the advantage of being scalable and can serve remote populations and underserved communities. + +Universal health coverage (UHC) is part of the post 2015 agenda geared to meeting the Sustainable Development Goals. Goal 3 "Ensure healthy lives and promote well-being for all at all ages" and its target 8 UHC cannot be achieved without the support of e-health. + +Today, 85% of WHO Member States report having at least one mobile health or mHealth initiative. + +Many mHealth initiatives are delivered through mobile platforms (mobile phones, smartphones or tablets). The increase in mobile device penetration is a key enabler of the solutions and their expansion. + +The growth of mobile-cellular-telephone subscriptions is greater than the growth in the global population. The growth in active mobile-broadband subscriptions has been very strong, with penetration rates increasing from 4.0 subscriptions per 100 inhabitants in 2007 to 69.3 per 100 inhabitants in 2018. The number of active mobile-broadband subscriptions have increased from 268 million in 2007 to 5.3 billion in 2018. + +Developing countries are registering much faster growth in mobile-broadband subscriptions than developed countries. In developing countries, penetration rates reached 61 per 100 inhabitants in 2018 and are expected to keep growing in the coming years. In the least developed countries (LDCs), penetration rates went from virtually zero in 2007 to 28.4 subscriptions per 100 inhabitants in 2018. Nearly the entire world's population, 96 per cent of it, now lives within reach of a mobile-cellular network. + +E-health solutions need to reflect the needs of health professionals and all citizens. If these platforms are not accessible, they will increase the digital divide and inequalities creating a barrier for attaining UHC. + +ICT should be available, affordable and accessible. An accessible ICT is different to an available ICT. mHealth applications should be available to everyone, affordable if they are meant to be used by underserved communities and persons with low levels of income and accessible to be used by persons with disabilities, older adults, persons with a temporary disability, immigrants or who do not speak any of the languages in which health care services are provided. + +In today's world, more than ever, it is important to guarantee that the digital information and digital platforms are accessible to everyone. Effective digital communication is imperative to reach everyone. + +The mHealth market was worth USD 86.4 billion in 2018 and is expected to be USD 504.4 billion by 2025. Governments, mHealth solutions developers, disabled persons organizations (DPOs) and academia should work together to guarantee that these e-solutions are developed considering universal design principles. + +The 2020 pandemic forced citizens all over the world to respect physical distancing. In this situation most information received was through electronic and digital formats. Mobile apps were developed for monitoring and tracking outbreaks. Non-accessible digital information or apps left persons with disabilities, older adults, immigrants and other vulnerable groups in a precarious situation that put their lives at risk. + +#### **1.1.1 Communication channels** + +All over the world, governments are informing citizens through digital platforms and in many cases informing through these channels could become critical to save lives. The WHO Strategic Communications Framework for effective communications emphasizes that *"audiences rely on their ability to access the information they need to protect and improve their health. Communicators should identify all channels available and map their capacities to reach priority audiences. Using the right mix of channels helps empower audiences with the information they need to make informed decisions"*. Communicators must consider the accessibility requirements of these communications channels to ensure all citizens are included and nobody is left behind. + +In the digital world we are living in accessibility is fundamental to insure inclusion. Within the WHO key audiences there are **individuals** who make decisions about their own health and the health of their families, **health-care providers** who make decision about screening diagnostics treatments and recommendations for patients, **communities** who make decisions about shared space activities and services with health consequences, **international organizations** who make decisions about funding and implementing health programmes, **policy makers** with responsibility for their residents health and persons with disabilities, older adults, immigrants and other vulnerable groups entitled to receive digital communications. Accessibility is a cross-topic that must be considered in every principle for effective communications. + +According to WHO, communication channels tend to fall into the three main categories described below. + +**Mass media.** These channels have broad reach and include television, radio, newspapers, magazines, outdoor and transit advertising, direct mail and websites. Placement through these channels may be free through public service announcements or may incur a cost if placement on certain platforms or at specific times is important. + +80% of countries reported that health-care organizations use social media for the promotion of health messages. These guidelines will provide the main requirements that need to be considered to make mass media communications inclusive. + +**Organization and community.** These channels reach specific groups of individuals based on geography (for example, a specific village) or a common interest, such as occupational status. Channels may include community-based media, such as local radio talk shows, organization newsletters; community-based activities, such as health fairs; and meetings at schools, workplaces and places of worship. + +Capacity building is important to communicators so they can reach everyone in the communities. + +**Interpersonal.** People seeking advice or sharing information about health risks often turn to family, friends, health-care practitioners, co-workers, teachers, counsellors and faith leaders. These one-on-one discussions are often the most trusted channels for health information. + +Effective leadership training is important to community leaders so they can reach everyone in the communities. + +#### I.1.2 e-health services + +The World Health Assembly of the World Health Organization adopted several Resolutions on e-health: the use of ICT for health. The implementation of these Resolutions will contribute to the achievement of UHC, an integral pillar to delivering the Sustainable Development Goals. e-health has been perceived as reducing the cost of health care, improving quality and equitable access to health services. Resolution WHA71.1 urges Member States to prioritize the development and greater use of digital technologies in health to promote UHC. As a result, today more than half of the WHO Member States have an e-health strategy. + +The Executive Board in January 2018 updated the report on mHealth recognizing that digital technologies are becoming an important resource for health services delivery and public health. Also, in collaboration with ITU, the WHO Secretariat is working to raise awareness, record trends, build capacity, establish guidance, and generate and document evidence on digital health, including mHealth, as a tool to promote user-centric, integrated service delivery. This strategy will consider ICT accessibility to ensure equity in the provision of digital services. + +E-health solutions must be evaluated and mapped according to the services needed as well as the target audience. Solutions should be user-centric reflecting the demands of health professionals and citizens. + +E-health solutions could be grouped in four main categories: + +- a) **e-learning platforms:** health-care systems worldwide face a severe health workforce shortage. Scaling-up of the health workforce is contingent on high-quality, relevant and up-to-date health science education, aimed at building the knowledge, skills, attitudes, behaviours and core values of health workers. The use of ICT for education is increasingly recognized as one of the key strategies for health workforce training. +- b) **Health information systems:** these would include software to manage health information, process reviews, statistics, medical records, etc. This information systems include the adoption of electronic health records (EHR) defined as real-time, patient-centred records that provide immediate and secure information to authorized users. Some examples of health information systems include: + - Management systems (appointments and patients' information) + - Patients records + - Patient monitoring + - Health surveys + - Treatment adherence + - Surveillance + - Decision support systems +- c) **mHealth:** mobile phone-based applications. They are normally used to take surveys, inform citizens and for monitoring and tracking outbreaks. In the 2015 Global Survey on e-health, mHealth was defined as the use of mobile devices – such as mobile phones, tablets, patient monitoring devices and wireless devices – for medical and public health practice. Examples of mHealth applications provided in the survey covered a broad list, from telephone helplines and text message appointment reminders to mobile telehealth and mobile access to electronic patient information. Some examples of mHealth applications are: + - Toll-free emergency numbers + - Health-care-centre helplines + - Appointment reminders + - Community mobilization + +- Information + - Mobile telehealth +- d) **Telemedicine or telehealth** are digital platforms used to exchange medical knowledge through distance consultation group discussions. The practice of distance medicine involves an interaction between a health-care provider and a patient when the two are separated by distance. That interaction may take place in real time (synchronously), for example by telephone or by use of a video link. However, it may also take place asynchronously (store-and-forward), when a query is submitted, and an answer provided later; (secure) email is an example of this technique. Some examples of telehealth uses are: +- Transmitting information for the purpose of diagnosis or consultation: + - Teleradiology + - Teledermatology + - Telepathology + - Interaction between health provider and patient: + - Telepsychiatry + - Remote patient monitoring + +#### I.1.3 ICT accessibility + +In line with global commitments of inclusiveness and the Convention on the Rights of Persons with Disabilities (CRPD), ITU also addresses the digital inclusion of persons with disabilities. ITU's membership is fully committed to advancing ICT accessibility implementation in their countries and regions. This is also reflected in ITU's engagements and contribution towards inclusiveness in several Resolutions adopted by our members to support implementation of digitally inclusive societies. Moreover, ITU Strategic Goal No. 2 "inclusiveness" and its target 2.9 calls on ITU members to ensure that *"By 2023, enabling environments ensuring accessible telecommunications/ICTs for persons with disabilities should be established in all countries"*. This is reflected in our work on ICT /digital accessibility for persons with disabilities and persons with specific needs aiming at ensuring that everyone, regardless gender, age, ability or location equally and equitably can benefit of and be empowered by ICTs. + +ITU work is fundamental to ensure that of e-health applications can be used by all. Digital accessibility enables digital inclusion and ensures inclusive communication for all people – regardless of their gender, age, ability or location. + +To achieve digital accessibility, ICTs should be not only be available and affordable, but also accessible, which means that they should be designed to meet the needs and abilities of as many people as possible – including those with disabilities. + +The accessibility of ICT is key given that ICTs have become the primary medium for communications, information, transactions, education, entertainment and health care worldwide. Its implementation by legislators and policy makers in all countries is essential to ensure respect for all people's rights to communicate in the connected world. + +The recognition of the human right of access information and the joint efforts of many stakeholders have resulted in the development of accessible mainstream software and hardware. ICT accessibility procurement policies by government took a major role in creating a market for inclusive technologies as well as the development of harmonized accessibility standards all over the world. + +While the use of e-health solutions is increasing in every country to achieve UHC, it is imperative to ensure that no one is left behind. + +### I.2 How do people consume digital information? + +As a result of the joint effort from different stakeholders to ensure that no one is left behind in the digital economy, today an important number of mainstream ICT devices and software are accessible. This means that these ICTs have embedded functionalities that eliminate barriers enabling different persons to use the services and products in equal circumstances. + +Not only persons with disabilities, older adults, immigrants and other vulnerable groups are the ones using special ICT features. There are many everyday life situations where everyone uses and benefits from the embedded accessibility features of mainstream ICTs; some examples are shown in Table I.1. + +**Table I.1 – Accessibility aspects for some everyday situations and potential beneficiaries** + +| Situation | Accessibility feature | Beneficiaries | +|------------------------------------------------------------|-----------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Checking your smartphone in bright sunlight | Changing the contrast of your mobile phone |
  • – Everyone
  • – Persons with low vision
  • – Older adults
  • – Colour blind persons
| +| Very small font size | Increase font size |
  • – Everyone
  • – Persons with low vision
  • – Older adults
| +| Sending a text message while moving | Use voice message functionality, voice to text |
  • – Everyone
  • – Blind persons
  • – Persons with a permanent or temporary motor impairment
  • – Illiterate persons
| +| Unable to read information | Use embedded screen reader |
  • – Everyone
  • – Blind and visually impaired persons
  • – Illiterate persons
  • – Persons with cognitive or learning disabilities
| +| Unable to reach your device | Use of voice assistance software |
  • – Everyone
  • – Blind and visually impaired persons
  • – Illiterate persons
  • – Persons with cognitive or learning disability
  • – Persons with a permanent or temporary motor impairment
| +| Unable to listen to your content (very noisy environments) | Captioning |
  • – Everyone
  • – Persons who are deaf or hard of hearing
  • – Illiterate persons
  • – Persons with cognitive or learning disability
| +| Unable to understand the language the content is in | Use subtitles translated in other languages, automatic translation software |
  • – Everyone
  • – Persons who are deaf or hard of hearing
  • – Immigrants
| + +**Table I.1 – Accessibility aspects for some everyday situations and potential beneficiaries** + +| Situation | Accessibility feature | Beneficiaries | +|-------------------------------------------|------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Need to interview someone from a distance | Use video calls, extra visual windows for sign language and chat boxes |
  • – Everyone
  • – Persons who are deaf or hard of hearing who lipread or need sign language interpretation
| +| Need to receive silent alerts | Use vibration options or light options |
  • – Everyone
  • – Persons who are deaf or hard of hearing
| + +These functionalities enhance the usability of the products and services are being utilized by everyone. Persons with more severe disabilities will use these functionalities alongside or instead of assistive technologies. + +When creating digital content or developing software, accessibility requirements should be considered to ensure the information can be consumed by the vast majority of persons. Making health-care information available to anyone needing it is both a human right and a responsibility. + +Building capacity and engaging stakeholders are essential steps to ensure e-health-care services are designed for everyone. + +### I.3 Accessibility guidelines for telehealth and e-health applications + +The accessibility guidelines for telehealth and e-health applications have the objective to describe the criteria that any stakeholder must consider guaranteeing the accessibility of the information and communication technologies used in health-care services. + +The WCAGs developed by the World Wide Web Consortium (W3C) are the international reference to ICT accessibility functionalities. + +ICT accessibility procurement standards all over the world describe the functional performance expected by an ICT to be accessible. Inclusion in ICT has to do with alternatives, with the availability of different ways to access and consume information and to interact with technology. + +The following accessibility guidelines are based on international standards and should be considered in the development, procurement and dissemination of e-health services and products. + +#### I.3.1 Communication channels + +Stakeholders will use different communications channels to provide information, advice and guidance to decision-makers (key audiences) to prompt action that will protect the health of individuals, families, communities and nations. It is fundamental that when this content is delivered in digital format, that it should be accessible for everyone. + +To ensure that everyone can have access to information through different digital channels, the following aspects must be considered: + +- 1) **Public information in audio and visual formats** delivered through electronic displays in public spaces such as railway platforms, retail stores, parks and other public areas may not be available for persons that do not have access to personal ICT devices. When possible, graphics and images should be displayed in addition to text. Sound alarms and/or sirens used during emergency situations must be accompanied by flashing lights to indicate the nature and level of threat. + +- 2) **Radios** should offer the possibility to be used with attached devices or with special features to enable its use by people who are deaf or hard of hearing, e.g., devices that can transmit broadcasts through vibrations, flashing lights and simple texts. Online live radio or podcasts should include the possibility of providing a transcription of the content. +- 3) **Television news casts must provide** closed captioning/ or subtitling in local languages to make audio commentary accessible to people who are deaf or hard of hearing, or who do not understand the language. In addition, sign language interpreters should be used when providing televised information about an emergency situation, for instance, a pandemic such as COVID-19. +- 4) **SMS:** people who need non-visual inputs and do not have access to smartphones that can convert text to other output formats such as audio will be excluded. Hence, warnings and alerts should also be issued in multiple formats across different dissemination channels. All images attached to messages must include alternative descriptions. +- 5) **If instant messaging applications** are used, it is necessary to ensure that those chosen are accessible and supported by screen readers embedded in mainstream smartphone operating systems. Voice assistants enable users to read instant messages aloud and dictate messages. Avoid using emojis when using **instant messaging applications**. +- 6) **E-mail** notifications should be provided in multiple languages. The email management software chosen should be designed following accessibility guidelines so that it can operate seamlessly on different devices and with a variety of assistive technologies. Some desktop alerting systems can ensure that pop-up messages are delivered in different formats in addition to texts and audio beeps. Use of graphics may assist people who have trouble understanding text. All images must include alternative descriptions. +- 7) **Social networks** are becoming increasingly accessible. Facebook, Instagram, Twitter and YouTube have been offering accessibility features for some time. It is important that the medical services and information agencies publishing information on these platforms are aware of digital content accessibility to ensure that the messages are accessible to all citizens. +- 8) **Websites** must be tested for accessibility to ensure that persons with disabilities do not face barriers in accessing the important information shared on them. Screen reader users may not be able to access the information on digital documents (Word, PDF) provided through websites if they are created in non-accessible formats, such as JPEG files or image-based PDF documents (e.g., scanned images). On the other hand, images and graphics are excellent ways to depict content for people with cognitive disabilities, or people with linguistic differences; however, these must be supplemented with textual information to ensure that persons with visual impairments using voice or Braille display output screen reading software are able to receive and understand the information. Links to external websites should be descriptive. Every element of the website should be keyboard accessible for persons that do not use a mouse. + +#### I.3.2 E-learning + +Online learning has shown significant growth over the last decade, as combining the Internet and education can provide individuals with the opportunity to gain new skills. The health-care sector is no stranger to this trend. + +There is an increasingly large number of e-learning platforms, and it is important to ensure the accessibility of both the platform and the learning content beforehand, so that all students can use them including those with disabilities and to prevent discrimination: + +- 1) **Universal access:** e-learning platforms must be supported by the device used by the student including built-in HTML with no requirements for add-ins. To achieve this, the platform should be designed and developed according to the W3C WCAGs 2.1 and the authoring tool accessibility guidelines (ATAG) 2.0. When a learning management system (LMS) includes + +accessibility features, students can navigate through its options, functionalities, courses and communication tools through the keyboard or a screen reader. + +2) **Accessible e-Learning content:** See the main body of text. + +#### **1.3.3 Health information systems** + +Health information system platforms are used to manage health information, processing reviews, statistics and medical records. + +Whether they are used for scheduling appointments or to manage information, these platforms should be accessible. Doctors with disabilities should be able to use these platforms as well as patients that need to interact with the technology. + +ICTs have an enormous impact in the sector processing information and making data available that eventually is processed and used to offer better services for everyone. The inclusion of persons with disabilities is fundamental to ensure that they are not left behind in this statistic. + +Online health information systems for public use through a website be developed according to WCAG 2.1. Images and graphics are excellent ways to depict and convey content to persons with cognitive disabilities, or people who do not speak the local language; however, these must be supplemented with alternative text information to ensure that persons with visual impairments using voice or Braille display output screen reading software are able to receive and understand the information depicted through the images and graphics. + +Every element of a website, including forms, schedules and maps, should be accessed with the keyboard for persons that do not use a mouse. + +Finally, to protect the right of full access to information, these systems need to ensure they provide individuals secure access to their personal medical records in accessible electronic formats. + +Electronic documents (Word, PDF, etc.) provided through these systems may be inaccessible by persons using assistive technologies such as screen readers if they are provided in formats that are not compatible with them, such as JPEG image files or scanned image PDFs (e.g., scanned images). + +#### **1.3.4 Mobile health (mHealth)** + +The introduction of mobile devices (smartphones, tablets, etc.) has greatly impacted many fields, including medicine. Health-care professionals now use mobile devices such as smartphones or tablets to carry out numerous tasks that were not possible some years ago. Smartphones and tablets combine both computing power and communication features in a single device that can be held in a hand or carried in a pocket, allowing easy access and use at the point of care. In addition to voice and text, new mobile device models offer more advanced features, such as web searching, global positioning systems (GPS), high-quality cameras and sound recorders. With these features, as well as powerful processors and operating systems, large storage capacity and high-resolution screens, mobile devices have essentially become handheld computers. + +It is essential that mobile apps developed for iOS or Android are accessible. Smartphones and tablets come with built-in accessibility features; however, to make the most of them, application user interfaces must be compatible with these functionalities. Even though there are not specific technical standards for mobile applications, the same accessibility principles that apply to web apply to mobile apps. + +Here are some guidelines to consider ensuring mobile apps are perceivable, operable and understandable. + +- a) Alternative text descriptions for non-text content: images and charts should have an alternative text that describes them. This text is not apparent to the view but is tagged in the code of the app so that certain voice output assistive technologies (built-in or installed) can detect and read them aloud. +- b) Videos and audio content should also have captions made available. Video players should display an accessible indication informing that captions are available alongside an accessible button next to the video screen that allows to turn captions on or off. +- c) Visible focus indicator. Persons with mobility or dexterity disabilities often rely on custom gestures to use their mobile devices. When doing so, it is necessary there is a clear indication of where focus is so that they know what element will be activated. +- d) Applications should display text in large font. +- e) If speech output is used, it must be possible to specify speech rate and volume. +- f) Some users find it easier to read and understand the content of an app by changing the style. For instance, presenting information in yellow on a black background, or highlighting text in blue. The user should be able to override the author's stylesheets to always display text in the needed colour scheme. +- g) Apps should provide full keyboard access for persons that use simple gestures to move between elements of the app. +- h) App should avoid using flashing content that could trigger photosensitive seizures. +- i) Apps must help users avoid and correct mistakes. +- j) Apps must provide persons with learning disabilities with adjustable time to carry out actions. +- k) Content should not be restricted to a single orientation. +- l) Apps must have a title, and content must follow a hierarchical structure by means of headings. + +### **I.4 Methodology and development process** + +For the development of the Recommendation, ITU and WHO adopted an inclusive stepwise approach, closely involving civil society including persons with disabilities and their representative organizations, as well as industry. The starting point in the development of the Recommendation was the identification of challenges and barriers that persons with disabilities experience when accessing telehealth services. For the purpose, firstly, a scoping literature review searching for evidence on barriers to telehealth services was carried out in relevant medical databases such as PubMed, and in a grey literature search. Search terms relevant to telehealth (e.g., telehealth, telemedicine, digital health, e-health services), disability (e.g., disability, persons with disabilities, people with disabilities) and barriers (e.g., barriers, access, inequality, gaps, challenges) were used to identify studies relevant to the topic. + +A set of barriers was identified, which served as a basis for discussion in a seminar organized by WHO and ITU in March 2021, where the input and perspective of civil society was sought. More than one hundred participants provided an additional list of challenges that were incorporated in the then draft Recommendation. In addition, an online survey was circulated among participants and other organizations of persons with disabilities that could not attend the seminar, seeking their additional contributions. After a complete set of challenges was defined, the corresponding requirements to address these barriers were determined. A workshop organized by ITU with the participation of representatives from the industry was held in June 2021 to obtain their perspective and input on the Recommendation. All these contributions enriched the Recommendation immensely. + +This Recommendation outlines the most important requirements on concrete accessibility features for equitable delivery of telehealth services. As such these requirements need to be adopted by governments when planning and implementing telehealth services, by manufacturers when designing the telehealth platforms to ensure a universal design, and lastly by health-care providers when delivering health-care services. The current Recommendation includes the necessary requirements that will help ensure equitable, accessible, effective and safe delivery of telehealth. However, the methods of implementation of these requirements may vary depending on resources available or technological advancements. Therefore, an implementation guide that contains practical and concrete solutions on how each of these requirements can be met to ensure compliance with the current Recommendation will be issued in the future. + +The recommendations included in this Recommendation are built around groups of persons with disabilities with different impairments. There are three main reasons why this approach has been taken. + +Firstly, the starting point in the development of the Recommendation were the challenges that persons with disabilities experience when using telehealth services. As persons with disabilities are a diverse group of individuals, their challenges, and hence the corresponding requirements, vary substantially and cannot be grouped into one category. Secondly, the Recommendation contains specific requirements for features that need to be incorporated in the design of the telehealth platforms. These features will then enable health-care providers to adapt their services to the different needs and priorities of persons with disabilities. For example, an available feature that provides the option of changing size and font of text will allow health-care providers to select the most appropriate font and size of text depending on the patient. As such, a list of requirements structured around types of disabilities will facilitate practitioners to have information on the specific needs of different populations, e.g., persons with hearing loss or persons with psychosocial disabilities. Finally, this Recommendation aims to standardize a whole sector. As many countries provide specialized teleservices such as tele-audiology focusing on a specific subpopulation, it is important to outline the requirements that persons who are deaf or hard of hearing have in this Recommendation. + +Even though this Recommendation is the result of a comprehensive evidence-based and consultative process, it does not pretend to be exhaustive. Future updates of the Recommendation will be issued if and when required. + +### I.5 Important resources + +- 1 ITU, *National E-Health Strategy Toolkit*, (2012), available at [https://www.itu.int/pub/D-STR-E\\_HEALTH.05-2012](https://www.itu.int/pub/D-STR-E_HEALTH.05-2012) +- 2 ITU Digital Inclusion – ICT/digital accessibility website and resources (including trainings and tutorials, guidelines, policies and strategies,) available at: + - [b-ITU-1] + - [ITU-D Creation and remediation of accessible digital contents](#) (video tutorials) [b-ITU-2] + - ITU-D [ICT Accessibility: the Key to Inclusive Communication](#) (self-paced online course) [b-ITU-3] + - ITU-D [Web Accessibility: the Cornerstone of an Inclusive Digital Society](#) (self-paced online course) [b-ITU-4] + - [Toolkit and Global Standard for safe listening devices and systems](#) (2019) [b-ITU-5] + - [Artificial Intelligence and Information Communication Technology Accessibility](#) (2019) [b-ITU-6] + - [Standards in the Procurement of Accessible Products and Services](#) (2019) [b-ITU-7] + +- [Future of Accessible Audiovisual Media Services, TV and Video Programming](#) (2019) [b-ITU-8] +- [Report to WTDC 2017 on Question 7/1: Access to telecommunication/ICT services by persons with disabilities and with specific needs](#) (2017) [b-ITU-9] +- [Model ICT Accessibility Policy Report](#) (2014) [b-ITU-10] +- [Universal Service Funds and Digital Inclusion for All](#) (2013) [b-ITU-11] +- [Making Mobile Phones and Services Accessible for Persons with Disabilities](#) (2012) [b-ITU-12] +- [Making Television Accessible](#) (2011) [b-ITU-13] + +- 3 WHO, *Resolution WHA71.1*, (2018), available at +[https://apps.who.int/gb/ebwha/pdf\\_files/WHA71/A71\\_R7-en.pdf?ua=1](https://apps.who.int/gb/ebwha/pdf_files/WHA71/A71_R7-en.pdf?ua=1) [b-WHO-4] +- 4 WHO, *mHealth Use of appropriate digital technologies for public health*, (2018) available at +[https://apps.who.int/gb/ebwha/pdf\\_files/WHA71/A71\\_20-en.pdf](https://apps.who.int/gb/ebwha/pdf_files/WHA71/A71_20-en.pdf) [b-WHO-5] +- 5 WHO, *mHealth New horizons for health through mobile technologies*, (2011), Global Observatory for eHealth series – Volume 3, available at + [b-WHO-6] +- 6 WHO, *WHO Strategic Communications Framework for effective communications*, (2017), available at +. [b-WHO-7] +- 7 WHO, *Be He@lthy Be Mobile Annual Report*, (2016), available at + [b-WHO-8] +- 8 WHO, *Global diffusion of eHealth: making universal health coverage achievable, Report of the third global survey on eHealth*, (2016), Global Observatory for eHealth, available at +. [b-WHO-9] +- 9 WFD / IFHOH statement on use of ASR [b-WFD] +- 10 NHS Accessible Information Standard + [b-NHS] + +# Bibliography + +- [b-ITU-T F.791] Recommendation ITU-T F.791 (2018), *Accessibility terms and definitions*. +- [b-FSTP.ACC-WebVRI] ITU FSTP.ACC-WebVRI (2022), *Guideline on web-based remote sign language interpretation or video remote interpretation (VRI) system*. +- [b-ITU RR] ITU Radio Regulations (2020), *Section IV. Radio Stations and Systems – Article 1.166*. +- [b-ITU-1] ITU (2023) *Digital Accessibility*. +- [b-ITU-2] ITU (2023), *Video-tutorials on the creation of accessible digital documents*. +- [b-ITU-3] ITU (2023), *Selfpaced online training on ICT accessibility (2023)*. +- [b-ITU-4] ITU (2023), *Self-Paced Online Course: "Web Accessibility – the Cornerstone of an Inclusive Digital Society"*. +- [b-ITU-5] ITU (2019), *Toolkit and global standard for safe listening devices and systems*. [https://www.itu.int/en/ITU-D/Digital-Inclusion/Pages/Digital\\_Inclusion\\_Resources/Strategies,%20policies,%20toolkits/Toolkit\\_safe\\_listening\\_devices/safe\\_listening.aspx](https://www.itu.int/en/ITU-D/Digital-Inclusion/Pages/Digital_Inclusion_Resources/Strategies,%20policies,%20toolkits/Toolkit_safe_listening_devices/safe_listening.aspx) +- [b-ITU-6] ITU (2019), *Artificial intelligence and information communication technology accessibility*. [https://www.itu.int/en/ITU-D/Digital-Inclusion/Documents/AI%20and%20ICT%20Accessibility\\_webEA3\\_Final.pdf](https://www.itu.int/en/ITU-D/Digital-Inclusion/Documents/AI%20and%20ICT%20Accessibility_webEA3_Final.pdf) +- [b-ITU-7] ITU (2019), *Standards in the Procurement of Accessible Products and Services*. +- [b-ITU-8] ITU (2019), *Future of accessible audiovisual media services, TV and video programming*. +- [b-ITU-9] ITU (2017), *Report to WTDC 2017 on Question 7/1: Access to telecommunication/ICT services by persons with disabilities and with specific needs*. +- [b-ITU-10] ITU (2019), *Standards in the procurement of accessible products and services*. +- [b-ITU-11] ITU (2013), *Universal service funds and digital inclusion for all*. [https://www.itu.int/en/ITU-D/Digital-Inclusion/Pages/Digital\\_Inclusion\\_Resources/Universal\\_Service\\_Funds\\_Digital\\_Inclusion.aspx](https://www.itu.int/en/ITU-D/Digital-Inclusion/Pages/Digital_Inclusion_Resources/Universal_Service_Funds_Digital_Inclusion.aspx) +- [b-ITU-12] ITU (2012), *Making mobile phones and services accessible for persons with disabilities*. [https://www.itu.int/en/ITU-D/Digital-Inclusion/Pages/Digital\\_Inclusion\\_Resources/Mobile\\_Phone\\_Accessible.aspx](https://www.itu.int/en/ITU-D/Digital-Inclusion/Pages/Digital_Inclusion_Resources/Mobile_Phone_Accessible.aspx) +- [b-ITU-13] ITU (2011), *Making Television Accessible*. +- [b-IETF RFC 3711] IETF RFC 3711 (2004), *The secure real-time transport protocol (SRTP)*. +- [b-IETF RFC 4347] IETF RFC 4347 (2006), *Datagram transport layer security*. + +- [b-IETF RFC 6347] IETF RFC 6347 (2012), *Datagram transport layer security Version 1.2*. +- [b-ISO 9999] ISO 9999:2022 *Assistive products for persons with disability – Classification and terminology*. +- [b-ISO/IEC 20071-23] ISO/IEC 20071-23:2018, *Information technology – User interface component accessibility – Part 23: Visual presentation of audio information (including captions and subtitles)*. + +- [b-Krupinski] Krupinski, E.A. and Bernard, J., (2014), March. *Standards and guidelines in telemedicine and telehealth*. In *Healthcare* (Vol. 2, No. 1, pp. 74-93). Multidisciplinary Digital Publishing Institute. +- [b-NHS] NHS (2017), *Accessible information standard*. +- [b-NSW] NSW Health (2016), *Telehealth framework and implementation strategy 2016-2021*. +- [b-W3C WAI] W3C (2023), *Web Content – WCAG 2*. +- [b-WHO-1] World Health Organization (2016), *Telehealth: Analysis of third global survey on eHealth based on the reported data by countries*. +- [b-WHO-2] World Health Organization (2001), *International classification of functioning, disability and health*. + +- [b-WHO-3] World Health Organization (2020), *The impact of the COVID-19 pandemic on noncommunicable disease resources and services: results of a rapid assessment*. +- [b-WHO-4] WHO (2018), *Resolution WHA71.1*. +[https://apps.who.int/gb/ebwha/pdf\\_files/WHA71/A71\\_R7-en.pdf?ua=1](https://apps.who.int/gb/ebwha/pdf_files/WHA71/A71_R7-en.pdf?ua=1) +- [b-WHO-5] WHO (2018), *mHealth use of appropriate digital technologies for public health*. [https://apps.who.int/gb/ebwha/pdf\\_files/WHA71/A71\\_20-en.pdf](https://apps.who.int/gb/ebwha/pdf_files/WHA71/A71_20-en.pdf) +- [b-WHO-6] WHO (2011), *mHealth new horizons for health through mobile technologies, (2011), Global Observatory for eHealth series, Vol. 3*. + +- [b-WHO-7] WHO (2017), *WHO Strategic Communications Framework for effective communications*. +- [b-WHO-8] WHO (2016), *Be He@lthy Be Mobile Annual Report*. + +- [b-WHO-9] WHO (2016), *Global diffusion of eHealth: making universal health coverage achievable, Report of the third global survey on eHealth, Global Observatory for eHealth*. + +- [b-WFD] World Federation of the Deaf (2019), *WFD/IFHOH statement on use of ASR*. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/F/T-REC-F.781.1-202406-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg b/marked/F/T-REC-F.781.1-202406-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d4d8969f805414689ab79cfd08c333d454d482b3 --- /dev/null +++ b/marked/F/T-REC-F.781.1-202406-I_PDF-E/0538daaa5583c23e17db3a12f2281a55_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:636c3839edff955a5b6208530b05fa1c983ab153d90f00216517a7a99478b988 +size 7074 diff --git a/marked/F/T-REC-F.781.1-202406-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg b/marked/F/T-REC-F.781.1-202406-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..84602a507b5741b85ccadd7bfbfc6cd8d6df7b3c --- /dev/null +++ b/marked/F/T-REC-F.781.1-202406-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:a9cf22337c94b0184d19fd17d27d70a2f47fcdd617f2c1a580636727cc243803 +size 79179 diff --git a/marked/F/T-REC-F.781.1-202406-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg b/marked/F/T-REC-F.781.1-202406-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e6c3136b8194834a563cfe8e445f5965663dcda0 --- /dev/null +++ b/marked/F/T-REC-F.781.1-202406-I_PDF-E/ebff22fb5dd6f50a90e44dca0f82f285_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:209b6df89f6615fd4b5e86a8721ee2edd04e5e269e476942971a0678887f0a03 +size 79788 diff --git a/marked/F/T-REC-F.781.1-202406-I_PDF-E/raw.md b/marked/F/T-REC-F.781.1-202406-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..9992f31bd32bc98ac5ab8bfb3a08fa8a3c4a9e52 --- /dev/null +++ b/marked/F/T-REC-F.781.1-202406-I_PDF-E/raw.md @@ -0,0 +1,366 @@ + + +# Recommendation **ITU-T F.781.1 (06/2024)** + +SERIES F: Non-telephone telecommunication services + +Multimedia services + +## --- **General framework of quality control of medical images for machine learning applications** + +![ITU logo](0538daaa5583c23e17db3a12f2281a55_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue circular emblem with a stylized globe and the letters 'ITU' in white. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.781.1 + +# General framework of quality control of medical images for machine learning applications + +## Summary + +Recommendation ITU-T F.781.1 sets up the initial framework for quality control on medical imaging for machine learning applications, including specifying the workflow of data quality control for machine learning applications, the requirements for medical input images, medical image integration, medical image annotation and criteria on data quality for machine learning applications. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.781.1 | 2024-06-13 | 16 | 11.1002/1000/15928 | + +## Keywords + +Machine learning, medical images, quality control, workflows. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2024 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|-----------------------------------------------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 1 | +| 4 Abbreviations and acronyms ..... | 1 | +| 5 Conventions ..... | 2 | +| 6 Background..... | 2 | +| 7 Workflow of data quality control ..... | 2 | +| 8 Requirements of medical input image ..... | 3 | +| 9 Requirements of medical image integration ..... | 4 | +| 10 Requirements of medical image annotation ..... | 4 | +| 11 Criteria on data quality for machine learning applications..... | 5 | +| 11.1 Criteria on the type of segmentation for images ..... | 5 | +| 11.2 Criteria on data distributions, data consistency and consistency in data
annotation process ..... | 6 | +| 11.3 Criteria on data governance and privacy considerations ..... | 7 | +| Bibliography..... | 8 | + + + +# Recommendation ITU-T F.781.1 + +# General framework of quality control of medical images for machine learning applications + +## 1 Scope + +This Recommendation gives a framework for the quality control of medical images for machine learning applications. Applications on chest volume computed tomography (CT) and eye disease image are also described. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ISO 12052] ISO 12052:2017, *Health informatics – Digital imaging and communication in medicine (DICOM) including workflow and data management*. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 artificial intelligence** [b-ISO/IEC 2382:2015]: Branch of computer science devoted to developing data processing systems that perform functions normally associated with human intelligence, such as reasoning, learning, and self-improvement. + +**3.1.2 machine learning** [b-ISO/IEC 2382:2015]: Automatic learning, process by which a functional unit improves its performance by acquiring new knowledge or skills, or by reorganizing existing knowledge or skills. + +### 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 data annotation**: The process of labelling data by humans usable for supervised machine learning. + +**3.2.2 supervised learning**: The machine learning task of learning a function that maps an input to an output based on example input-output pairs. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|----|-------------------------| +| AI | Artificial Intelligence | +| CT | Computed Tomography | +| ED | Euclidean Distance | + +| | | +|-----|------------------------------| +| IoU | Intersection over Union | +| ML | Machine Learning | +| MR | Magnetic Resonance | +| SOP | Standard Operating Procedure | + +## 5 Conventions + +The following conventions are used in this Recommendation: + +- The keywords "should (is required to)" indicate a requirement which must be strictly followed and from which no deviation is permitted if conformance to this document is to be claimed; +- The keywords "can (is recommended to)" and "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus this requirement needs not be present to claim conformance; +- The keywords "may (can optionally)" indicate an optional requirement which is permissible, without implying any sense of being recommended. These terms are not intended to imply that the vendor's implementation must provide the option and the feature can be optionally enabled by the network operator/service provider. Rather, it means the vendor may optionally provide the feature and still claim conformance with the specification. + +## 6 Background + +Digital technologies are considered huge potential promoters in the fields of medicine and public health. While machine learning (ML) and artificial intelligence based technologies hold great promise to reduce human workload, this rapidly developing field also remains uncertain. If the model is poorly designed or the underlying training data are biased or incorrect, errors or problematic results can occur in ML applications. Therefore these technologies can only be used with complete confidence if it has been quality controlled through a rigorous evaluation in a standardized way, especially in the scenarios of the large-scale dataset from multisources. + +As one of the most common data modalities in medical diagnosis and treatment, the medical image is targeted in this document to address the following questions of how to: + +- Assist the quality control from standard operating procedure; +- Reduce model performance problems caused by inconsistent training data; +- Enable large-scale dataset projects on high diversity of data formats and multi-annotators; +- Improve understanding and train skills for non-professional annotators. + +## 7 Workflow of data quality control + +In the process of supervised machine models, data quality is one of the most dependable factors in the performance of computer auxiliary diagnosis. Medical images need to be collected, integrated, processed and annotated in a standardized way, then the raw dataset with manual annotations can be used in training and validation for optimization, as well as testing datasets for the evaluation process. A standard operating procedure for data quality control is shown in Figure 1. During the testing and evaluation of the supervised machine models, unqualified annotations may be identified, which should be relabelled or deleted from the dataset. + +![Figure 1 – Workflow of data quality control. The diagram illustrates a three-step process: 1. Collection (Sub-set 1, Sub-set 2, ..., Sub-set n) leading to a Medical image dataset. 2. Integration, which involves Data annotation (influenced by External knowledge medical terminology, Annotators, and Tools) and Standard operating procedure (SOP). 3. Annotation, leading to Annotation metadata. The Medical image dataset is then split into Training dataset, Validation dataset, and Test dataset. These datasets are used for Supervised machine learning, which leads to a Training process (with a feedback loop) and Testing and evaluation. The Testing and evaluation step feeds back into the Collection step. A label F.781.1(24) is present in the bottom right corner.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +Figure 1 – Workflow of data quality control. The diagram illustrates a three-step process: 1. Collection (Sub-set 1, Sub-set 2, ..., Sub-set n) leading to a Medical image dataset. 2. Integration, which involves Data annotation (influenced by External knowledge medical terminology, Annotators, and Tools) and Standard operating procedure (SOP). 3. Annotation, leading to Annotation metadata. The Medical image dataset is then split into Training dataset, Validation dataset, and Test dataset. These datasets are used for Supervised machine learning, which leads to a Training process (with a feedback loop) and Testing and evaluation. The Testing and evaluation step feeds back into the Collection step. A label F.781.1(24) is present in the bottom right corner. + +**Figure 1 – Workflow of data quality control** + +## 8 Requirements of medical input image + +Biomedical information evolved with the practice of medicine and engineering technologies at an unprecedented speed through the medical images obtained by human body imaging, high-resolution viewing of cells and pathological specimens. Modalities covered in common measurement include X-ray, ultrasound, magnetic resonance (MR), X-ray, CT, nuclear medicine and high-resolution microscopy, etc. Table 1 refers to the common medical measurement modalities in medical field and Table 2 shows a summary of input data modalities for machine learning applications. + +**Table 1 – Summary of common medical measurement modalities** + +| | Dimensionality | Description | Anatomies | +|-----------------------------|--------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------| +| X-ray | 2D, 2D+t | Produces images by measuring the attenuation of X-ray through the body, via a detector array | Most organs | +| CT | 2D, 3D, 3D+t | Creates 2D cross-sectional images of the body by using a rotating X-ray source and detector | Most organs | +| Ultrasound | 2D, 2D+t, 3D, 3D+t | A transducer array emits acoustic pulses and measure the echoes from tissue scatters | Most organs | +| MR | 3D, 3D+t | Use a magnetic field to align protons; radiofrequency and gradient pulses are used to selectively excite protons in tissues and blood in order to measure their spatially encoded nuclear magnetic resonance signals | Most organs | +| Nuclear medicine technology | 2D, 3D, 3D+t | Measures the emission of gamma rays from the decay of radioisotopes introduced into the body using external detectors/gamma cameras | All organs with radioactive tracer uptake | +| Microscopy | 2D, 3D, 3D+t | Typically uses an illumination source and lenses to magnify specimens before capturing an image | Primarily biopsies and surgical specimens | + +**Table 2 – Summary of input data modalities for AI4H tasks** + +| Data | Dimensionality | Description | Examples | +|------------------|-----------------------|----------------------------------------------|--------------------------------------| +| Image | 2D | Two-dimensional medical imaging | – Fundus photos | +| 3D images | 3D | Three-dimensional spatial imaging | – Sets of CT slices | +| 4D | 4D (3D+t) | 3D space imaging changes over time | – Heart film imaging | +| Video | 2D +t | Camera or monitor recording | – Falls among the elderly | +| Audio/
signal | 1D +t | Sound or transmitted in signal form. | – Heart sound/ECG | +| Text | 1D, 2D | Structured/unstructured description in words | – Case history, diagnosis extraction | +| Single number | 1D | Single measurement data | – Blood pressure or respiratory rate | + +## 9 Requirements of medical image integration + +To avoid bias in medical image collection, it is suggested to consider a balanced data distribution in the process of data preparation and medical image integration. + +The image data collected is stored in format compatible with the DICOM system [ISO 12052], for example the one in [b-DICOM PS3.5]. + +To avoid bias in data distribution, it is suggested that the process be carried out by grouping and crossing, and ensure the effective resolution of inconsistencies. Several annotators (represented as variable $n$ in Figure 2) are invited to label the raw dataset. Certain qualifications are required of the annotators, for example, that they be doctors and trained annotators in the specific case domain. + +However, for cost considerations, some projects will also set up one annotator (Set $n$ to 1) in this parallel independent annotation part, and then go to arbitration if difficulties are encountered. + +## 10 Requirements of medical image annotation + +In addition to the quality of the raw image itself, data annotation is one of the most dependable factors in the performance of supervised machine models. The annotation process of medical images is also suggested to be carried out by grouping and crossing. Figure 2 illustrates a recommended standard operating procedure formulated process of data annotation, with much feasibility through variables and configurable threshold, to establish a unified understanding and quality control mechanism in the data annotation process. + +![Flowchart of the data annotation procedure. It starts with 'Data distribution' leading to 'Independent annotation' (Annotator-1 to Annotator-n) and 'Arbitration' (Annotation n+1 to n+m). Both lead to 'Label fusion'. The first 'Label fusion' leads to a 'Consistency in labelling' decision. If 'Yes', it goes to 'Put in the annotation metadata set'. If 'No', it goes to 'Expert reviewing'. 'Expert reviewing' leads to 'Put in the annotation metadata set' (Yes) or 'Discard' (No). The second 'Label fusion' also leads to a 'Consistency in labelling' decision. If 'Yes', it goes to 'Put in the annotation metadata set'. If 'No', it goes to 'Expert reviewing', which then leads to 'Put in the annotation metadata set' (Yes) or 'Discard' (No).](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +``` + +graph TD + DD[Data distribution] --> IA[Independent annotation] + DD --> AR[Arbitration] + subgraph IA[Independent annotation] + direction TB + A1[Annotator-1] --> AN1[Annotation 1] + A2[Annotator-2] --> AN2[Annotation 2] + Ai[Annotator-i] --> ANi[Annotation i] + An[Annotator-n] --> ANn[Annotation n] + end + subgraph AR[Arbitration] + direction TB + ANn1[Annotation n + 1] --> ANnm[Annotation ... n + m] + end + ANn --> LF1[Label fusion] + ANnm --> LF2[Label fusion] + LF1 --> CL1{Consistency in labelling} + CL1 -- Yes --> PMS1[Put in the annotation metadata set] + CL1 -- No --> ER[Expert reviewing] + ER -- Yes --> PMS2[Put in the annotation metadata set] + ER -- No --> DISC[Discard] + LF2 --> CL2{Consistency in labelling} + CL2 -- Yes --> PMS3[Put in the annotation metadata set] + CL2 -- No --> ER + +``` + +Flowchart of the data annotation procedure. It starts with 'Data distribution' leading to 'Independent annotation' (Annotator-1 to Annotator-n) and 'Arbitration' (Annotation n+1 to n+m). Both lead to 'Label fusion'. The first 'Label fusion' leads to a 'Consistency in labelling' decision. If 'Yes', it goes to 'Put in the annotation metadata set'. If 'No', it goes to 'Expert reviewing'. 'Expert reviewing' leads to 'Put in the annotation metadata set' (Yes) or 'Discard' (No). The second 'Label fusion' also leads to a 'Consistency in labelling' decision. If 'Yes', it goes to 'Put in the annotation metadata set'. If 'No', it goes to 'Expert reviewing', which then leads to 'Put in the annotation metadata set' (Yes) or 'Discard' (No). + +Figure 2 – Data annotation procedure + +## 11 Criteria on data quality for machine learning applications + +### 11.1 Criteria on the type of segmentation for images + +For the type of segmentation for images, criteria such as the Jaccard index and Dice's coefficient are recommended to use for detection and segmentation for images. Detailed calculation methods are shown in Table 3. + +- The Jaccard index: Jaccard index is also known as intersection over union (IoU) and the Jaccard similarity coefficient, which is a statistic used for gauging the similarity and diversity of sample sets. +- Dice's coefficient: Dice's coefficient is the quotient of similarity and ranges between 0 and 1. This coefficient is not very different in form from the Jaccard index, and they have a connection as $J = D/(2 - D)$ , $D = 2J/(1 + J)$ . + +Table 3 – Criteria on data quality for machine learning + +| Criteria | Calculation method | Graphical representation | +|---------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Jaccard index |

Numerator represents the area of overlap between two annotations; Denominator represents the area encompassed by two annotations. Dividing the area of overlap by the area of union yields our final score.

$J(A, B) = \frac{ A \cap B }{ A \cup B } = \frac{ A \cap B }{ A + B - A \cap B }$ |

Image: Venn diagram showing two overlapping circles A and B. Circle A is yellow, circle B is orange, and their intersection is purple and labeled A ∩ B. The individual parts of the circles are labeled A and B.

| + +**Table 3 – Criteria on data quality for machine learning** + +| Criteria | Calculation method | Graphical representation | +|--------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------| +| | | $J = D/(2 - D), D = 2J/(1 + J)$ | +| Dice's coefficient | Numerator represents the double area of overlap between two annotations; Denominator represents the sum of two annotation area. Dividing the area of overlap by the sum area yields our final score.
$D = \frac{2 A \cap B }{ A + B }$ | | + +For the type of localization, criteria like Euclidean distance (ED) are recommended to use for localization. ED is a commonly used definition of distance, which refers to the true distance between two points in the m-dimensional space. + +In 2D space, $ED((x_1, y_1), (x_2, y_2)) = \sqrt{(x_1 - x_2)^2 + (y_1 - y_2)^2}$ . + +In 3D space, $ED((x_1, y_1, z_1), (x_2, y_2, z_2)) = \sqrt{(x_1 - x_2)^2 + (y_1 - y_2)^2 + (z_1 - z_2)^2}$ . + +### 11.2 Criteria on data distributions, data consistency and consistency in data annotation process + +The data quality standards for machine learning applications should embody the characteristics of authority, scientific rigour, traceability, diversity, closeness and dynamicity. + +**Authority:** Considering that the quality of data depends mainly on the quality of data labelling, the data-collection process should include authorities in the corresponding clinical specialties. Data annotators and annotation disagreement arbitrators should have appropriate and sufficient experience in clinical practice, respectively. + +**Scientific rigour:** To guarantee the training dataset reflect the actual clinical situation, the sample size of the database should be determined by statistical calculations to control sampling error, and the distribution of the samples should be in line with the characteristics of the target diseases, without data augmentation. + +**Traceability:** Quality control procedures documents should be established for data annotation-related activities, which should meet the requirements for traceability. The documents should cover three core phases: requirements clarification and confirmation; staff training and pilot annotation; final quality control and acceptance. Continuous monitoring and checking should be undertaken throughout the process. The project manager should periodically select a certain percentage of the annotated data for detailed quality checks. + +**Diversity:** Data should be sourced from multiple clinical institutions to ensure that the database can be used to evaluate the generalization ability; an appropriate proportion of adversarial data samples may be included to evaluate the robustness of the algorithm, provided that ethical requirements are met. + +**Closeness:** To ensure that the quality of the algorithms can be adequately and objectively evaluated, the database should be kept closed. + +**Dynamicity:** The database should be replaced with a certain percentage of data on a regular basis to ensure that it has continued diversity and closure. + +### **11.3 Criteria on data governance and privacy considerations** + +A complete framework of privacy policy standards should be established, clarifying the basic content and key terms to be included, providing a reference model for privacy policy formulation and effectively adopting privacy labelling. + +It is recommended that the content of privacy terms be displayed in the form of labelling and/or masonry layouts, to enable users to understand the rights and obligations of personal information protection contained in the privacy policy. + +## Bibliography + +- [b-ITU FG-AI4H] ITU-T (2023), FG-AI4H Deliverables, *DEL05.3: Data annotation specification*. + +- [b-ISO/IEC 2382] ISO/IEC 2382:2015, *Information technology – Vocabulary*. +- [b-DICOM PS3.5] DICOM PS3.5 2024c (2024), *DICOM Part 5: Data Structures and Encoding 2023*. + +- [b-FDA] United States Food and Drug Administration (2019), *Proposed Regulatory Framework for Modifications to Artificial Intelligence/Machine Learning (AI/ML) Based Software as Medical Device*, FDA discussion paper. + +- [b-NMPA] National Medical Products Administration (2019), *Key Points for the Review and Evaluation of Deep Learning Based Software as Medical Device*, NMPA guidance 28 Jun [in Chinese]. + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for 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systems in rural and out-of- home environments** + +![ITU logo](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with white lines representing latitude and longitude, and the letters 'ITU' in a bold, blue, sans-serif font overlaid on the globe. + +ITU logo + +## ITU-T F-SERIES RECOMMENDATIONS **Non-telephone telecommunication services** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | F.1-F.109 | +| Operating methods for the international public telegram service | F.1-F.19 | +| The gentex network | F.20-F.29 | +| Message switching | F.30-F.39 | +| The international telemessage service | F.40-F.58 | +| The international telex service | F.59-F.89 | +| Statistics and publications on international telegraph services | F.90-F.99 | +| Scheduled and leased communication services | F.100-F.104 | +| Phototelegraph service | F.105-F.109 | +| MOBILE SERVICE | F.110-F.159 | +| Mobile services and multdestination satellite services | F.110-F.159 | +| TELEMATIC SERVICES | F.160-F.399 | +| Public facsimile service | F.160-F.199 | +| Teletex service | F.200-F.299 | +| Videotex service | F.300-F.349 | +| General provisions for telematic services | F.350-F.399 | +| MESSAGE HANDLING SERVICES | F.400-F.499 | +| DIRECTORY SERVICES | F.500-F.549 | +| DOCUMENT COMMUNICATION | F.550-F.599 | +| Document communication | F.550-F.579 | +| Programming communication interfaces | F.580-F.599 | +| DATA TRANSMISSION SERVICES | F.600-F.699 | +| MULTIMEDIA SERVICES | F.700-F.799 | +| ISDN SERVICES | F.800-F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850-F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900-F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.792 + +# Requirements on accessible moveable communication systems in rural and out-of-home environments + +## Summary + +Recommendation ITU-T F.792 describes the requirements of an accessible interactive mobile digital unit in rural and out-of-home environments. It is intended for areas where communication functions are not available or have been disrupted due to absence of infrastructure. This Recommendation builds on the use cases of accessibility described in ITU-T Technical Paper FSTP-ACC-Rural (2023), *Use cases of accessibility to multimedia systems in rural and out-of-home environments*. + +It is applicable also when unavailability of communication functions is brought about by disasters, which have been increasing worldwide in recent years, or for areas where communication functions have not been provided or are insufficient. It standardizes the requirements of communication systems to enable the required communication functions to be up and running in the out-of-home environment resistant to harsh environment. + +## History\* + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|----------------|------------|-------------|--------------------| +| 1.0 | ITU-T F.792 | 2025-03-16 | 21 | 11.1002/1000/16247 | + +## Keywords + +Accessibility, moveable communication systems, rural and out-of-home environments. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2025 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +###### Page + +| | | | +|--------------|---------------------------------------------------------------------------------------|----| +| 1 | Scope ..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| 3.1 | Terms defined elsewhere ..... | 1 | +| 3.2 | Terms defined in this Recommendation..... | 2 | +| 4 | Abbreviations and acronyms ..... | 2 | +| 5 | Conventions ..... | 2 | +| 6 | Background..... | 2 | +| 7 | Interactive digital mobile unit..... | 3 | +| 7.1 | Basic architecture of IDMU ..... | 3 | +| 7.2 | General requirements of IDMU..... | 3 | +| 7.3 | General requirements on information and communication service functions of IDMU ..... | 4 | +| 7.4 | User access to IDMU..... | 4 | +| 8 | Moveable local cloud (MLC) ..... | 4 | +| 8.1 | Architecture and components of MLC ..... | 4 | +| 8.2 | General requirements of MLC..... | 5 | +| 8.3 | MLC information and communication service functions..... | 5 | +| 9 | Networking of MLC ..... | 6 | +| 9.1 | Connection to an existing network..... | 6 | +| 9.2 | Coverage area expansion by wired and wireless links ..... | 7 | +| 9.3 | Networking with multiple MLC ..... | 7 | +| 10 | Security ..... | 7 | +| 10.1 | Security of IDMU ..... | 7 | +| 10.2 | Security of MLC..... | 7 | +| Appendix I | – Information on mobile and deployable ICT resource units ..... | 8 | +| I.1 | Implementation example ..... | 8 | +| I.2 | External physical appearance ..... | 8 | +| I.3 | External interface..... | 8 | +| I.4 | External logical appearance..... | 9 | +| I.5 | Preferred configuration of mobile and deployable ICT resource units ..... | 9 | +| I.6 | Consideration of mobile and deployable ICT resource unit sizes ..... | 9 | +| Appendix II | – An example of IDMU design ..... | 11 | +| Appendix III | – Reference architecture and network configuration of IDMU ..... | 12 | +| Appendix IV | – Accessibility use cases of IDMU ..... | 15 | +| IV.1 | Auditory processing disorder ..... | 15 | +| IV.2 | Visual impairment ..... | 16 | + +| | Page | +|-----------------------------|-------------| +| IV.3 Motor disability ..... | 16 | +| Bibliography..... | 17 | + +# Recommendation ITU-T F.792 + +# Requirements on accessible moveable communication systems in rural and out-of-home environments + +# 1 Scope + +This Recommendation describes requirements of the mobile communication unit (i.e., interactive digital mobile unit (IDMU)) reachable in remote areas and by large groups of people where it could be shared considering open sky environment, out-of-home environment and portable local cloud systems as an important means of accessibility in inaccessible areas as well as in emergencies. + +This Recommendation builds on the use cases of accessibility described in the ITU-T Technical Paper FSTP-ACC-Rural (2023), *Use cases of accessibility to multimedia systems in rural and out-of-home environments* [b-ITU-T ACC-Rural] and describes the technical requirements for the features, including accessibility. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[[ITU-T F.790](#)] Recommendation ITU-T F.790 (2007), *Telecommunications accessibility guidelines for older persons and persons with disabilities*. + +[[ITU-T H.702](#)] Recommendation ITU-T H.702 (2020), *Accessibility profiles for IPTV systems*. + +[[ITU-T L.392](#)] Recommendation ITU-T L.392 (2016), *Disaster management for improving network resilience and recovery with movable and deployable information and communication technology (ICT) resource units*. + +# 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following term defined elsewhere: + +**3.1.1 coverage area** [b-ITU-R V.573-4]: Area associated with a transmitting station for a given service and a specified frequency within which, under specified technical conditions, radiocommunications may be established with one or several receiving stations. + +NOTE 1 – Several coverage areas may be associated with one and the same station. + +NOTE 2 – The technical conditions include the following: characteristics of the equipment used both at the transmitting and receiving stations, how it is installed, quality of transmission desired, e.g., protection ratios and operating conditions. + +NOTE 3 – The following may be distinguishable: - interference-free coverage area, i.e., that limited solely by natural or artificial noise - the nominal coverage area: it is defined, when establishing a frequency plan by taking into account the foreseen transmitters - the actual coverage area, i.e., with allowance made for the noise and interference which exists in practice. + +NOTE 4 – Furthermore, the term "service area" should have the same technical basis as for. + +### 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 local cloud:** A cloud in which computer resources are closer to users and only the local network is used. It is also called intranet with server function. + +NOTE – A normal cloud is a mechanism that uses computer resources such as data and applications via a network, and the Internet is usually assumed as the network. + +**3.2.2 social networking service:** A type of online social media platform that people use to build social networks or social relationships. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|---------------------------------| +| AP | Access Point | +| FWA | Fixed Wireless Access | +| IDMU | Interactive Digital Mobile Unit | +| LAN | Local Area Network | +| MLC | Moveable Local Cloud | +| ONU | Optical Network Unit | +| SCS | Satellite Communication System | +| SNS | Social Networking Service | +| WAN | Wide Area Network | +| WLAN | Wireless Local Area Network | + +## 5 Conventions + +The following conventions are used in this Recommendation: + +- The keywords "is required to" indicate a requirement which must be strictly followed and from which no deviation is permitted, if conformance to this Recommendation is to be claimed. +- The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely required. Thus, this requirement need not be present to claim conformance. + +# 6 Background + +Lack of communication functions can result from various reasons. One common reason is the lack of infrastructure itself, such as in developing countries. Or it can result from temporary disruptions such as insufficient provision of electricity in rural areas or out-of-home situations. Still another case is abrupt disruption by disasters. In any of these situations, it is necessary to have an efficient, practical and robust communication equipment and systems to cope with such, often harsh, environments. This is especially important from the point of accessibility of persons with disabilities as they constitute the more vulnerable segment of communities and are more dependent on ICT accessibility. The IDMU is designed to ameliorate such situations and to provide better accessibility in rural areas. The use cases of accessibility are described in [b-ITU-T ACC-Rural]. Since IDMU is expected to provide multimedia information communication services, accessibility features described in [ITU-T H.702] should be considered as well. In addition, the guideline in [ITU-T F.790] is expected to be observed by functions of IDMU so that IDMU can operate to provide accessibility in rural, remote areas as well as in an emergency situation. + +# 7 Interactive digital mobile unit + +### 7.1 Basic architecture of IDMU + +Remote areas are often characterized by very limited network use or the complete inability to use information and communication services. Such a situation is also created by disasters, which cause failures or damage to resources such as communication equipment necessary for providing information and communication services. + +Figure III.1 shows the functional architecture of IDMU. + +The application layer primarily consists of the moveable local cloud (MLC) and interfaces for output and input. These interfaces allow the basic interactive bidirectional communication between IDMU and the user. It is expected that IDMU has at least one large-size screen which has output devices, such as display and input devices that could include a video camera and an audio system with a speaker and microphone. MLC is the source of content and control of these devices. + +The network layer provides internal connection within IDMU as well as between MLC and external networks. The network resources component provides external connections. The most important connection is through the satellite communication system (SCS). More details are described in clause 8. + +The system layer is the primary control layer of IDMU. It controls the energy sources. It also has a control function over temperature. It also has the capability of monitoring the overall system of IDMU. The most important part of the system layer is the energy sources, the primary of which is photovoltaic and is provided by an external solar panel. + +The physical layer of IDMU provides the capability to move. The mobility function may be provided autonomously or by an external source, such as by traction. + +An example of a physical design of IDMU can be found in Appendix II as well as in [b-ITU-T ACC-Rural]. + +### 7.2 General requirements of IDMU + +The following are the general requirements on the design of IDMU: + +- IDMU is required to have a capability to be moveable; +- IDMU is required to have a large-sized screen for displaying video; + +NOTE 1 – An example of a large-sized screen is described in Appendix II. + +- IDMU is required to have a photovoltaic energy source, such as a solar panel that can be used to convert sunlight into electricity; +- IDMU is required to provide accessibility for persons with disabilities and people with specific needs such as physical disabilities, visual impairment and auditory disabilities. + +NOTE 2 – [b-ITU-T ACC-Rural] and Appendix IV describe some features of accessibility related to IDMU. In addition, the guideline in [ITU-T F.790] should be observed. When IDMU is used to provide video delivery and other IPTV-like services, at least the basic profile of [ITU-T H.702] is required to be supported. + +- IDMU is required to have the main components that ensure minimum ICT connectivity; +- IDMU is recommended to have a monitoring screen with external interfaces that enables conferencing using video, audio and text; +- IDMU is recommended to have a camera and microphone for interactive communication; +- IDMU is recommended to have a temperature resistant design; +- IDMU is recommended to have a system for cooling equipment; +- IDMU is recommended to have a system for monitoring remotely; + +- IDMU is recommended to have node function fluidity and mobility to replace existing multifunction network nodes, if any, that may take a long time to recover be deployed; +- IDMU is recommended to be able to enable easy, rapid and automated configuration and service set-up to reduce the time to delivery of telecommunications services; +- IDMU is recommended to be capable of adaptive and dynamic network and service control and operation in order to make good use of limited information and communication resources; +- IDMU is recommended to take security and privacy into considerations when restoring the original complex ICT services, where applicable. + +### 7.3 General requirements on information and communication service functions of IDMU + +The information communication service functions provided by IDMU are recommended to be implemented as software installed on the MLC server, as specified by [ITU-T L.392]. + +IDMU is recommended to provide the basic functions of the information communication services, namely authentication functions, information communication functions and platform functions. + +The basic information communication functions include the following: + +- "Connect" function of one-to-one two-way (bidirectional) communication. + +NOTE 1 – This includes telephone and leased line service + +- Broadcast function, i.e., one-to-many, one-way (i.e., unidirectional) communication. + +NOTE 2 – This includes video distribution. Displaying a home-page without any "return" link may also be considered "unidirectional". + +- Information-sharing function of the type many-to-many, two-way (bidirectional) communication between unspecified many. + +NOTE 3 – This includes social networking services (SNSs). + +- Group communication function (many-to-many, two-way communication between specific multiple). + +### 7.4 User access to IDMU + +IDMU is recommended to allow users to access IDMU from smartphone, tablet or computer with WLAN capability as well as IDMU public terminal displays. + +IDMU is recommended to allow the user to connect to the web server of MLC using the browser software normally installed on the user's device, through which the information communication function provided by MLC can be utilized. + +# 8 Moveable local cloud (MLC) + +MLC is useful for quickly and easily setting up a local information and communication environment in rural areas as well as in the event of a communication outage caused by a large-scale disaster, and for responding to critical information and communication demands using network-connected mobile terminals. This clause describes a MLC equipped with the basic communication functions via the Internet. + +### 8.1 Architecture and components of MLC + +See Figure III.2 for the basic architecture of MLC. + +MLC is required to have the following components. + +- 1) Connection function with user terminals (access network function); + +- 2) Information processing function (server/storage function) to accommodate information communication function/cloud function to operate without power supply for a certain period of time (photovoltaic and solar battery function); +- 3) Functions for portability + +NOTE – It is required to be safe when kept in an infrastructure at outdoor or an open sky environment, such as by being stored in a portable case, etc. Considering portability and operability, it is preferable to use a combination of light and compact general-purpose products. + +MLC is required to have an information communication service function, which provides the basic functions of the information communication service. + +MLC is required to have functions for connecting to other networks such as the Internet. + +MLC is required to have functions that increase the utility value of provided services by interconnecting multiple MLCs. + +The basic components of MLC are described in Appendix III. + +### **8.2 General requirements of MLC** + +The following are the general requirements of MLC: + +- MLC is required to ensure minimum connectivity by its main components; +- MLC is required to have its own information and communication services as an intranet function, and will be equipped with its fluidity and mobility; +- MLC is recommended to provide easy, fast and automated configuration (service set-up) to reduce the time to delivery of telecommunications services; +- MLC is recommended to be capable of adaptive and dynamic network/service control and operation in order to make the best use of limited information and communication resources; +- MLC is recommended to be easily implementable and able to provide necessary information processing functions in addition to basic information communication functions; +- MLC is recommended to be able to connect and synchronize multiple MLCs and other networks and network services provided by telecommunications companies including the Internet and other intranets, enabling expansion of service areas and functions provided by connecting with other MLCs. + +### **8.3 MLC information and communication service functions** + +The information and communication service functions provided by MLC are recommended to be implemented as software installed on the MLC server. The basic functions of the information and communication services provided include authentication, information and communication and platform functions. + +MLC is recommended to have at least the following information and communication functions: + +- Connecting function; +- Broadcasting function; +- Information-sharing function; +- Group communication function. + +MLC is required to have the function of registering and authenticating the user ID of the terminal used when the user accesses these information communication functions. + +MLC is recommended to have a platform function that enables users to install and provide software that provides the necessary functions according to their intended use. + +NOTE 1 – The platform function (or cloud function) is basically an information processing function (a function that allows the user to install and use software suited to the purpose of use). + +NOTE 2 – Platform functions may include installing and utilizing various e-services such as e-government system or a learning management system on a server in order to use MLC as part of distance learning in the field of education. + +MLC is recommended to support content formats for text, file, image, audio and video, for its distributed content service. + +MLC is recommended to be able to provide real-time communication, except when the services are provided by multiple MLC or in cooperation with the Internet, in which case delays can be tolerated. + +MLC is recommended to allow easy and effective use and portability, by providing the following features: + +- After installation, the system can start up and enter the operational phase as soon as the power is turned on. +- When stopping operation, the system can be shut down with a simple operation. +- The basic functions can be operated and operated without the operator's technical knowledge and skills. +- Even in the event of a system failure, services can be easily restored using substitute products. For this reason, general-purpose items that are easy to procure and repair should be used as much as possible for the components of the system. + +# **9 Networking of MLC** + +### **9.1 Connection to an existing network** + +Appendix III shows the hierarchical structure of the MLC connection to the existing information and communication service network. + +MLC is recommended, in order to connect to the existing networks, to have functional components that satisfy the interface requirements for connection to the network termination devices of the existing networks, such as subscriber termination devices, mobile base stations, network termination devices and satellite communication termination devices. + +MLC is recommended to have the function of quickly setting up a local information and communication environment in a rural environment. + +MLC is recommended to have the function of connecting to the Internet via a connection terminal that connects to an external network of MLC. + +MLC is recommended to connect to an external network, i.e., the Internet, via one of the following methods: + +- A fixed communication line through termination devices such as an optical line termination device ONU; +- A mobile network service such as 2G, 3G, LTE and 5G; +- A satellite communication line. + +MLC is recommended to allow users to use services on the Internet as well as to provide an environment where MLC can be accessed from the Internet. + +NOTE – Access to MLC from the Internet enables the external observer monitor MLC's surroundings in rural areas. + +### 9.2 Coverage area expansion by wired and wireless links + +It is recommended that MLC be capable of expanding its service area by connecting to external communication devices using WLAN as an access network. + +NOTE 1 – From the viewpoint of network configuration, the area can be expanded within the same LAN or by connecting different LANs, depending on whether or not a router is used for external connection. + +NOTE 2 – Methods for connecting MLC to external communication devices (other LANs, other WLAN APs, etc.) to expand the MLC service area include a method of connecting by wireless link using FWA devices, or a method of connecting by optical fibre or wired cable. + +NOTE 3 – Another method is to make the MLC WLAN AP device compatible with mesh network and form a mesh network by distributing multiple similar APs. + +NOTE 4 – By connecting an Ethernet cable to the LAN hub of the MLC and extending it for several hundred metres to several kilometres, and then connecting a WLAN AP to the end of the cable, a new coverage area can be formed. In addition to wired links, wireless links between points can also be used to expand the coverage area. + +Appendix III shows a typical situation of the expansion of the coverage area by connecting MLC to a wired or wireless link. + +### 9.3 Networking with multiple MLC + +It is recommended that MLC be capable of being connected to multiple other MLC scattered around rural areas, via an external communication network. In that case, user terminals connected to MLC can refer to and use the contents of other networked MLC to the extent that their access rights allow. + +NOTE 1 – Other MLC connected to an MLC may be MLC software installed on the Internet cloud. + +NOTE 2 – By connecting to other MLC via the WAN interface of the MLC, it becomes possible to incorporate multiple MLC into a single network as independent inter-LAN connections. + +Appendix III shows a typical situation of area expansion by WAN connection of an MLC. + +# 10 Security + +### 10.1 Security of IDMU + +Because IDMU is moveable, it is necessary to consider both physical and cybersecurity. However, especially in rural areas, its physical security should primarily be considered. + +The following are minimum requirements: + +- IDMU is required to be constructed securely. +- IDMU is required to be capable of being lodged securely. + +Further details of security are for future study. + +### 10.2 Security of MLC + +Because MLC is portable, it is necessary to consider both physical and cybersecurity. + +For physical security, measures such as installing a locking mechanism to prevent access to the equipment inside the MLC case are required. In addition, measures such as locking and fixing the MLC itself to a building are also necessary to prevent theft. + +For cybersecurity, security measures such as installing a firewall, which is used when a general LAN is connected to the Internet, are recommended. + +## Appendix I + +## Information on mobile and deployable ICT resource units + +(This appendix does not form an integral part of this Recommendation.) + +### I.1 Implementation example + +Examples of IDMU implementations are shown in [b-ITU-T ACC-Rural], where the physical characteristics of IDMU are described. An amphibious type of IDMU, for non-land environments, is also described there. [ITU-T L.392] also shows examples of MLC implementation. + +In many cases, IDMUs are usually located near remote or disaster response centres or shelters and are capable of establishing wireless access networks (see Figure I.8 of [ITU-T L.392]) and fixed wireless access (FWA). System can be configured to allow communication with remote shelters. + +Depending on the situation, it may be difficult to bring even a small vehicle type IDMU to a disaster area. In such cases, an amphibious type or briefcase-type MLC can be considered, which can easily be transported and brought in to provide a limited range of telecommunications services. + +Figure I.9 of [ITU-T L.392] shows a briefcase-type IDMU providing basic multimedia communication services or only telephony services. + +By selecting the appropriate type of IDMU, it is possible to provide as many ICT services as possible according to the situation in the remote or disaster area. + +### I.2 External physical appearance + +The most basic requirement for an IDMU is that it should be transportable by normal means of transportation. A basic physical appearance should be specified to meet this requirement. + +Basic physical parameters of IDMU: + +- The shape, size and weight should allow for portability mobility and versatility. + +NOTE 1 – Long antennas hinder transport and antennas should be disassembled and reassembled for installation. Extendable antennas are another solution to facilitate transportation. + +During transportation: + +- Resistance to transport stress (e.g., degree of tilt and impact loads); +- Charging/solar: A function that continues to operate even on motion. + +NOTE 2 – To reduce system set-up time, some functions should remain active while the unit is in transit. + +After installation: + +- Power supplied or battery capacity, if the unit is equipped; +- Electromagnetic compatibility (EMC) requirements to be met; +- Resistance to temperature and humidity (harsh environments); +- Operating conditions such as indoors and outdoors. + +### I.3 External interface + +The IDMU is expected to support the specified external interfaces to accommodate connectivity to the core network, persistent access networks and terminal accommodation. The specification covers from the physical interface to the logical interface of each layer. + +NOTE – Regarding physical implementation, wireless and fixed cable interfaces can also be considered. + +### **I.4 External logical appearance** + +It is important to mobilize sufficient ICT resources (provided by IDMU) and sufficient service capabilities for resources to meet the needs of the affected areas in the event of a large-scale disaster. To treat multiple IDMUs in the same way without worrying about device-specific or manufacturer-specific settings, the parameters associated with the IDMUs are expected to be the same. + +The IDMU needs to present its logical appearance. Specifically, it should demonstrate the IDMU's basic functions, its quantitative capacity and related performance. Standards are expected to provide a set (or a limited number of sets) of reference parameters and target values. + +IDMU reference parameters are expected to exhibit at least the following basic functionality: + +- Supported input/output (I/O) interfaces (in terms of physical media type, speed and number of ports); +- Networking (regarding dynamic allocation, registration, routing, switching throughput address space capacity and number of end terminals supported); +- Computing capacity (usually indicated by operating clock frequency, number of processors, etc.) – Storage [size of memory available on board and hard disk drive (HDD) or solid state drive (SSD)]. + +### **I.5 Preferred configuration of mobile and deployable ICT resource units** + +Some general settings for IDMU functionality and performance may be specified to facilitate deployment of IDMUs in remote areas, specific disaster areas or areas of difficult access. + +Here are some initial considerations for these reference settings: + +- Standalone or building block type; + +NOTE – Building block type IDMUs are intended to be used in combination with other units that interact and provide higher overall performance. + +- Ultralightweight type; +- Versatile, easy to tow or driven by electric motor; +- Green and clean energy; +- Switching-intensive type, interface-rich type, processor-intensive type or memory-rich type – ultra power saving type; +- High or low temperature resistant type; +- Type for rural or urban areas. + +### **I.6 Consideration of mobile and deployable ICT resource unit sizes** + +There are a variety of IDMU implementations, from motor to animal traction, local capacity tow facilities or electric self-driving car for small distances, or train shipping containers, to compact. + +MLC can even be implemented in an easy-to-carry briefcase. Therefore the components in the IDMU are assumed to be modular, so that any combination of components can be used and any package size can be accommodated. Larger size implementations may have economies of scale. A small size implementation can accommodate high mobility. + +Some of the design points to be considered in selecting and constructing an IDMU are as follows: + +- Transportability: Weight and size are major factors for transportability. To guarantee versatility speed to transport and time to recovery determine the effectiveness of the IDMU. When choosing size and mass, the basis of the means of transport (train containers, helicopters and military transport aircraft and ordinary cars, or other methods of traction) should be considered. + +- Geographical area covered and time to deployment: Depending on the area covered and the period of use, the size of the IDMU will vary. In some cases, IDMU is used (semi-) permanently. For such long-term use, larger (capacity- and feature-rich), more durable implementations are desirable, where the combination of smaller implementations is difficult to achieve. +- Reachability from the core network: Many services can be provided from remote clouds if a broadband path is available to the IDMU, as seen in the cloud. Otherwise, the local site resources and functionality provided by the IDMU should be plentiful, and a larger size is preferred. + +In terms of resource capacity and mobility, a possible menu of IDMU implementations is given in [ITU-T L.392], Figure I.10. + +## Appendix II + +## An example of IDMU design + +(This appendix does not form an integral part of this Recommendation.) + +This appendix shows an example of a physical design of an IDMU; see Figure II.1. The example is taken from [b-ITU-T ACC-Rural]. The unit consists of a 5100 × 1800 × 2500 mm crate with five 250 W solar panels kit totalling an installed capacity of 1.25 kW and a 3 kW hybrid inverter. On one side of the unit there is a 100 inch (i.e., dimensions of 254 cm diagonally, width 213.36 cm and height 152.4 cm) screen – expandable to 200 inches (508 cm diagonally), with 1920 × 1080 pixel resolution – equipped with anti-glare to guarantee the best outdoor experience without sun reflection. This large screen can also be used as a whiteboard. On this side a monitoring screen can also be found. + +![Diagram of an IDMU (Intelligent Digital Mobile Unit) on a trailer, showing its various components and features.](41245ac07db266bea228735b9e8c8b73_img.jpg) + +The diagram illustrates an IDMU unit mounted on a dual-axle trailer. The unit is a dark-colored box with a large screen on its side. Several callouts with orange boxes and lines point to specific features: 'Group interaction' points to the top edge, 'Solar energy/photovoltaic' points to a sun icon on the top left, 'Monitoring screen (Touch) Video/Audio/Text' points to a smaller screen on the left side, 'Webcam' points to a camera on the top right, and '+100 inch giant screen and whiteboard' points to the main screen. The main screen displays a video of a person in a white lab coat. Four orange silhouettes of people are standing in front of the unit. To the right, a speaker on a tripod is shown with musical notes, labeled 'Sound'. The code 'F.792(25)' is visible in the bottom right corner of the image area. + +Diagram of an IDMU (Intelligent Digital Mobile Unit) on a trailer, showing its various components and features. + +Figure II.1 – An example of IDMU + +## Appendix III + +## Reference architecture and network configuration of IDMU + +(This appendix does not form an integral part of this Recommendation.) + +Figure III.1 shows the functional architecture of IDMU. + +![Functional architecture of IDMU diagram showing layers and components.](9b9d2abd741ed4bafe7f78f89961c663_img.jpg) + +The diagram illustrates the functional architecture of the IDMU, organized into four layers: + +- Application layer:** Contains the **MLC** (Mobile Logic Controller) which connects to **Output IF** (Output Interface) and **Input IF** (Input Interface). These interfaces connect to **Output devices** and **Input devices**, which are further connected to **Screen, etc.** +- Network layer:** Contains **Network resources** and **Network IF** (Network Interface). The **Network IF** connects to **Satellite, etc.** +- System layer:** Contains **Energy sources** (connected to **Solar panel, etc.**), **System monitoring**, and **Cooling system**. The **Energy sources** connect to the **MLC**, **System monitoring**, and **Cooling system**. The **System monitoring** and **Cooling system** are interconnected. +- Physical layer:** Contains **Mobility control**, which connects to the **MLC**. + +F.792(25) + +Functional architecture of IDMU diagram showing layers and components. + +Figure III.1 – Functional architecture of IDMU + +Figure III.2 shows the basic architecture of MLC. + +![Basic architecture of MLC diagram showing internal components and external connections.](77464a47f104d0d647b2414591137b64_img.jpg) + +The diagram illustrates the basic architecture of the MLC (Mobile Logic Controller) and its connections: + +- Internal components:** The MLC server, LAN hub, Wi-Fi AP (With router), and Battery are shown within a blue boundary. +- Connections:** + - The **MLC server** is connected to the **LAN hub** via a **COM line**. + - The **LAN hub** is connected to the **Wi-Fi AP (With router)** via a **Power line**. + - The **Battery** is connected to the **MLC server** via a **Power line**. + - The **MLC server** is connected to **To solar and other energy source**. + - The **LAN hub** has an external connection to **Connection to extended LAN (e.g., to other APs)**. + - The **Wi-Fi AP (With router)** has an external connection to **Connection to WAN (e.g., to other MLCs, or other NW)**. + - A **Laptop** is connected to the **LAN hub** via a **Wired connection**. + - Smartphones or tablets** are connected to the **Wi-Fi AP (With router)** via **Wi-Fi connections**. + +F.792(25) + +Basic architecture of MLC diagram showing internal components and external connections. + +Figure III.2 – Basic architecture of MLC + +Figure III.3 shows the basic components of MLC. + +![Diagram of basic components of MLC showing Application layer and User network/device layer.](7f25db95ce3916c0e09803b861a2f7bc_img.jpg) + +The diagram illustrates the basic components of MLC, organized into two layers: + +- Application layer:** This top layer is enclosed in a dashed box labeled "MLC". It contains three components: "E-services", "(Local) cloud service", and "(Localized) data centre". +- User network/device layer:** This bottom layer contains three devices: "Laptop", "Smartphone", and "IoT". Above these devices are two network components, "LAN" and "Wi-Fi". Arrows indicate connections from each device to both "LAN" and "Wi-Fi". + +F.792(25) + +Diagram of basic components of MLC showing Application layer and User network/device layer. + +**Figure III.3 – Basic components of MLC** + +Figure III.4 shows an MLC connecting to existing networks. + +![Diagram showing MLC connecting to existing networks like Internet, ISP, and Satellite.](10781f43062bf3e9601a1e086710556c_img.jpg) + +This diagram shows how an MLC connects to various existing networks. At the top, a block labeled "E-services" contains four items: "E-learning", "Telehealth", "E-government", and "Social media". Below this, a cloud labeled "Internet" is connected to a box labeled "ISP". The "ISP" is also connected to a box labeled "Cloud service" and "Data centre". To the right, a "Satellite" box is connected to the "Internet" cloud and to a "SATCOM" box. Below the "ISP", there is a section containing "Core network" and "Access network". The "ISP" connects to an "ONU", a "Mobile station", and an "NTD" within this section. The "SATCOM" box connects to the "NTD". At the bottom, an "MLC" box is connected to the "ONU", "Mobile station", and "NTD". Below the "MLC" are three user devices: "Laptop", "Smartphone", and "IoT". A "Users" button is at the very bottom. + +F.792(25) + +Diagram showing MLC connecting to existing networks like Internet, ISP, and Satellite. + +**Figure III.4 – MLC connecting to existing networks** + +Figure III.5 shows a typical situation of the expansion of the coverage area by connecting a MLC to a wired or wireless link. + +![Diagram of Figure III.5 showing the expansion of coverage area by connecting a MLC to a wired or wireless link.](83852ec55d4802521a727926336bedab_img.jpg) + +This diagram illustrates the expansion of a wireless LAN coverage area. It features three main components connected by wired links: + + +- An **Extended wireless LAN area** on the left, represented by a cloud containing a Wi-Fi access point (antenna icon) connected to three **Smartphones**. +- A central **MLC** (Mobile LAN Controller) unit, which includes a **Wi-Fi access point** and an **MLC server** (represented by a server rack icon). +- Another **Extended wireless LAN area** on the right, also containing a Wi-Fi access point connected to three **Smartphones**. + + The central MLC unit is connected to both the left and right Wi-Fi access points via **Wired link** lines. The label **F.792(25)** is present in the bottom right corner. + +Diagram of Figure III.5 showing the expansion of coverage area by connecting a MLC to a wired or wireless link. + +**Figure III.5 – Expansion of the coverage area by wired and wireless links** + +Figure III.6 demonstrates connecting multiple IDMUs. + +![Diagram of Figure III.6 showing the connection of multiple IDMUs to a central MLC server via a private network.](523ab7b925beb555f88b2e1e1336974f_img.jpg) + +This diagram shows the connection of multiple IDMUs (Identity Management Units) to a central MLC server. At the top, a box labeled **The Internet** contains a **Private network** segment. Below this, three identical IDMU units are shown, each consisting of an **MLC** unit (with a server icon) and a **Wi-Fi access point** (with an antenna icon). Each IDMU is connected to the **Private network** via a line. Below each IDMU, three **Smartphones** are connected wirelessly to its Wi-Fi access point. The label **F.792(25)** is present in the bottom right corner. + +Diagram of Figure III.6 showing the connection of multiple IDMUs to a central MLC server via a private network. + +**Figure III.6 – Connecting multiple IDMUs** + +## Appendix IV + +## Accessibility use cases of IDMU + +(This appendix does not form an integral part of this Recommendation.) + +The following text is taken from [b-ITU-T ACC-Rural]. + +"Accessibility" to multimedia goes beyond the interaction with the platform. It also (and mainly) entails conveying the intended message in a way that is perceptible by all members of the community, regardless of age, literacy level, gender or any other characteristic potentially considered exclusive, including disabilities. Because access to reliable information is crucial for the well-being of the populations, this interactive mobile unit uses a blend of digital audio, touch screens, video, sign language speech/word recognition and text to present content using GSM satellite connectivity. It also enables inclusion of persons with disabilities, with auditory processing disorders and visual impairment, while promoting faster comprehension of the content delivered. + +In addressing these challenges, we have implemented educational campaigns in some Mozambican communities to broadcast one-way and two-way communications in partnership with the *Government of the Republic of Mozambique*, in particular with the *Minister of Science, Technology and Higher Education, Minister of Education, Minister of Health and University Eduardo Mondlane*. These collaborations help disseminate technology in areas previously not considered for digital initiatives. Our 2-way outdoor videoconference communication broadcast allows remote engagement with the communities, but in the absence of means of data connectivity, the group and individual engagements are maintained through artificial intelligence (AI) enhancing virtual reality. + +Among the most important considerations to be made when standardizing content for effective broadcasting, are aligning content with local culture, habits and religion in order to maximize its acceptance and ease of comprehension in the target community. + +With regards to the deployment of information, administration and management of ICT accessibility, the most effective modes of operation are divided into 10 different activities. Integrated mechanisms are applied to accommodate every single person including illiterate and people with disabilities and can be divided into four (4) sets as described below: + +- 1) Touch screen text = selection of text in quizzes – mostly used by general population including illiterate and people with auditory processing disorders. +- 2) Touch screen with images and sign language = Selection of images in quizzes – mostly used by people who are illiterate and those with auditory processing disorders. +- 3) Touch screen by voice/text = Voice triggers word recognition – mostly used in quizzes for illiterate people and those with visual impairments. +- 4) Non-touch screen = Sign language – sign language is a support for people with low perception capabilities or those with auditory processing disorders. The most effective strategies used during this period for capacity building of people with auditory processing disorders and visual impairments are described in clauses 8.1 to 8.3. + +### IV.1 Auditory processing disorder + +As a good practice, a summary of all the topics was provided in large text, illustrative images and sign language after every session on large digital screens to allow the audience to recap key learnings before testing their levels of understanding. Text in preferred language, videos with sign language (hand shape, palm orientation and facial expression) images and text were also used in digital quizzes with auto correct features. Multiple-choice quizzes allowed users to choose the correct answer by using the touch screen functionality and to receive feedback or an auto correction by text or images, enabling continued access, interactivity and engagement with ICT after broadcasting. + +### **IV.2 Visual impairment** + +In this regard, audio in their preferred language was most effective. Additionally, digital quizzes were equipped with voice-word recognition trigger features that have a pre-programmed local language. This allowed further learning, interactivity and engagement with ICT after broadcasting, by asking participants a question and giving three possible spoken answers to allow the user to choose the correct answer using speech, followed by spoken feedback or a spoken auto correction. + +### **IV.3 Motor disability** + +A wheelchair makes a lot of difference in the life of its users. There are a lot of positive differences if you look from the viewpoint of the person for whom wheelchair is the only mode of mobility. However, there are lots of daily life problems that every wheelchair user has to face. To make our platform more inclusive and accessible to as many people as possible, the touch screens are adjustable in height so that people with mobility challenges that move around in wheelchairs can easily reach them. + +## Bibliography + +- [b-ITU-T ACC-Rural] ITU-T Technical Paper FSTP-ACC-Rural (2023), *Use cases of accessibility to multimedia systems in rural and out-of-home environments.* +- [b-ITU-R V.573-4] Recommendation ITU-R V.573-4 (2000) *Radiocommunications vocabulary.* + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| 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a/marked/F/T-REC-F.812-199208-I_PDF-E/raw.md b/marked/F/T-REC-F.812-199208-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..0b6ad5829613615d0ccc0bb082c5349ebbfc999c --- /dev/null +++ b/marked/F/T-REC-F.812-199208-I_PDF-E/raw.md @@ -0,0 +1,278 @@ + + +![ITU logo: A globe with a lightning bolt and the letters ITU.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: A globe with a lightning bolt and the letters ITU. + +INTERNATIONAL TELECOMMUNICATION UNION + +**CCITT** + +THE INTERNATIONAL +TELEGRAPH AND TELEPHONE +CONSULTATIVE COMMITTEE + +**F.812** + +(08/92) + +**TELEMATIC, DATA TRANSMISSION, +ISDN BROADBAND, UNIVERSAL, +PERSONAL TELECOMMUNICATIONS +AND TELECONFERENCE SERVICES +OPERATIONS AND QUALITY OF SERVICE** + +--- + +**BROADBAND CONNECTIONLESS DATA +BEARER SERVICE** + +![CCITT logo: A globe with the letters CCITT.](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +CCITT logo: A globe with the letters CCITT. + +**Recommendation F.812** + +# FOREWORD + +The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988). + +Recommendation F.812 was prepared by Study Group I and was approved under the Resolution No. 2 procedure on the 4th of August 1992. + +# --- CCITT NOTES + +- 1) In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized private operating agency. +- 2) A list of abbreviations used in this Recommendation can be found in Annex B. + +# **BROADBAND CONNECTIONLESS DATA BEARER SERVICE** + +(1992) + +## **1 Definition** + +A **B-ISDN connectionless data service** is defined as a service which allows the transfer of information among service subscribers without the need for end-to-end call establishment procedures between users. + +## **2 Description** + +### **2.1 General description** + +This is a public packet-switched service that provides for the transfer of variable-length data units at high speed without the need for call establishment procedures between users. These data units can be transferred from a single source to a single destination, or from a single source to multiple destinations. Each data unit includes a source address validated by the network. One generic feature of a B-ISDN connectionless bearer service is that it may include broadcasting capabilities. + +The B-ISDN connectionless data bearer service uses addresses based on the E.164 ISDN numbering plan. + +For multicast communication an address scheme using group addressing is required. Group addressing is a mechanism which allows for the transmission of the same data unit to several intended recipients. A group address is an address used to represent the set of individual addresses that identify the destinations of a group addressed data unit. + +The source address used in a group addressed data unit may be one of the individual addresses. + +The B-ISDN connectionless data bearer service is designed such that, under normal conditions, subscriber's end-to-end protocols would not require changes. This allows user's communications architectures as well as the applications built on top of the connectionless service to remain intact. + +This service is offered on the B-ISDN on ATM connections between the subscriber and a connectionless service node named "connectionless server", as it is defined in Recommendation I.211. + +This service will be supported on the B-ISDN user-network interface (UNI) based on asynchronous transfer mode (ATM). + +### **2.2 Specific terminology** + +#### **2.2.1 Point-to-point** + +Refer to Recommendation I.210. + +#### **2.2.2 Broadcast** + +Unidirectional communication from a single source entity to an unlimited number of unspecified destination entities. + +#### **2.2.3 Multicast** + +Unidirectional communication from a single source entity to a limited number of specified destination entities. + +*Note* – Examples of communication configurations related to these terms in § 2.2.2 and 2.2.3 can be found in Table 1/F.812. + +| | | | +|-----------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------| +| Broadcast | Diagram of broadcast communication: a source box on the left has three arrows pointing to three destination boxes on the right. Below the arrows is the text 'Unspecified destination'.
Unspecified destination | | +| Multicast | Diagram of multicast communication: a source box on the left has three arrows pointing to three destination boxes on the right. Below the arrows is the text 'Specified destination'.
Specified destination | Video distribution | + +T0102990-93 + +TABLE 1/F.812 +**Examples of communication configuration** + +#### 2.2.4 *Protocol data unit (PDU)* + +A block of data consisting of all information for end-to-end transmission (user data, addressing information and service parameters). + +#### 2.2.5 *CL-PDU* + +Connectionless protocol data unit (see § 2.2.4). + +#### 2.2.6 *LANs* + +Local area networks. + +### 2.3 *Applications* + +Some applications that could be supported by B-ISDN connectionless data service are: + +- high speed file transfer with low latency; +- interconnection of LANs; +- distributed processing; +- multi-site interactive computer aided design (CAD). + +## 3 **Procedures** + +### 3.1 *Provision/withdrawal* + +3.1.1 By arrangement with the Administration. + +#### 3.1.2 *Normal procedures* + +The service may be provided directly accessed by high speed end systems or by means of gateways using permanent, semi-permanent or switched connections between the subscribers' premises and the connectionless service node. + +### 3.2 *Normal procedures* + +#### 3.2.1 *Activation/deactivation/registration* + +Upon request from the user, the service provider provides all necessary functions for enabling end-to-end transmission. + +#### 3.2.2 *Invocation and operation* + +In normal operation the user sends data without establishing, releasing or maintaining a connection. All information which is required to route the data from the source to the destination is contained in the connectionless CL-PDU (see § 2.2.4). + +### 3.3 *Exceptional procedures* + +Not applicable. + +### 3.4 *Alternate procedures* + +Not applicable. + +### 3.5 *Validation* + +Each CL-PDU includes a source address validated by the network. + +### 3.6 *Quality of service* + +#### 3.6.1 *General* + +This section covers user oriented aspects of quality of service (QOS) specific to the broadband connectionless data bearer service. Overall principles for QOS for B-ISDN are contained in Recommendation I.350. + +User oriented QOS issues are focused on end-to-end perceivable effects and not on their causes within the network. + +Parameters for user QOS could be measured at the UNI. + +#### 3.6.2 *Categories of user defined QOS* + +##### 3.6.2.1 *Lost PDU ratio* + +This parameter defines the ratio of total number of PDU's sent by the originator and not delivered at the destination UNI to the total number of PDU's sent. + +$$\frac{\text{Total PDU's not delivered}}{\text{Total PDU's sent}} \times 100 = \% \text{ lost PDU}$$ + +##### 3.6.2.2 *Maximum transfer delay* + +This parameter defines the maximum PDU transfer delay between the source UNI and the destination UNI. If the transfer of a PDU exceeds the time limit, the PDU is assumed lost to the user. + +This time delay includes, in a B-ISDN environment, the sum of the cell delays per switch and per transmission system, and the PDU disassembly and reassembly at the source and destination nodes. + +##### 3.6.2.3 *PDU, integrity* + +This parameter defines the frequency of corrupted and/or duplicated PDU's. + +## 4 Network capabilities for charging + +This Recommendation does not cover charging principles. Future Recommendations in the D-Series are expected to contain that information. + +However, charging for the service may be offered under tariffs containing usage sensitive rate elements (e.g. volume of data or transmission distance). + +## 5 Interworking requirements + +The broadband connectionless data bearer service should provide interworking to other connectionless services in private and/or public networks. + +To support interworking the B-ISDN should provide the appropriate interface, bit rate and protocol conversion facilities when necessary. + +Also, interworking between the connectionless (CL) and connection oriented (CO) data services should be assumed. + +## 6 Possible supplementary services examples include: + +- Closed User Group; +- Address Screening. + +## ANNEX A (to Recommendation F.812) + +### Broadband connectionless data bearer service category + +| Sub-categories | D | +|----------------------------------------------------------|------------------------------| +| Bearer service attributes | Value of attributes | +| Information transferred attributes | | +| 1 Information transfer mode | PDU (Note 1) | +| 1.1 Connection mode | Connectionless (CL) | +| 1.2 Traffic type | Variable bit rate (VBR) | +| 1.3 Timing end-to-end | Not required | +| 2 Information transfer rate (bit/s) | | +| 2.1 Peak bit rate | (Note 2) | +| 2.2 Mean bit rate | (Note 2) | +| 3 Information transfer capability | Unrestricted | +| 4 Structure | Protocol data unit integrity | +| 4.1 Maximum CL-PDU size | (Note 3) | +| 5 Establishment of communication (ATM access connection) | Demand, reserved, permanent | + +| Sub-categories | D | | | +|-------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--| +| Bearer service attributes | Value of attributes | | | +| Information transferred attributes (cont.) | | | | +| 6 Symmetry | Unidirectional | | | +| 7 Communication configuration | Point-to-point, multicast | | | +| Access attributes | | | | +| 8 Access channel and rate (bit/s) | | | | +| 8.1 User information | The medium service bit rate at 155.52 Mbit/s, 622.08 Mbit/s interfaces is for further study (Note 2) | | | +| 8.2 Signalling | Signalling virtual channel for signalling for ATM access connection | | | +| 9 Access protocols | | | | +| 9.1 Signalling access protocol – Physical layer | Rec. I.432 | For establishment of switched connections between the B-ISDN subscriber and the CL service node.
Connectionless protocols above the ATM adaptation layer are for further study | | +| 9.2 Signalling access protocol – ATM layer | Recs. I.150, I.361 | | | +| 9.3 Signalling access protocol – ATM adaptation layer [AAL] | Rec. I.363, type 3 | | | +| 9.4 Signalling access protocol layer 3 (above AAL)
(Here “layer 3” corresponds to signalling terminology, not B-ISDN PRM.) | Recs. Q.930, Q.931 (Note 3) | | | +| 9.5 Information access protocol – Physical layer | Rec. I.432 | | | +| 9.6 Information access protocol – ATM layer | Recs. I.150, I.361 | | | +| 9.7 Information access protocol – ATM adaptation layer [AAL] | Recs. I.362, I.363, type 4 (Note 3) | | | +| 9.8 Information access protocols – Layers above AAL | (Note 3) | | | +| General attributes | | | | +| 10 Supplementary services provided | Closed User Group
Address Screening | | | +| 11 Quality of Service | Lost PDU ratio
Maximum transfer delay
PDU integrity | | | + +| Sub-categories | D | +|---------------------------------------|------------------------------------------| +| Bearer service attributes | Value of attributes | +| General attributes (cont.) | | +| 12 Interworking possibilities | With other CL services and data services | +| 13 Operational and commercial aspects | | + +*Note 1* – The PDU provides for the transfer of the service information. However, this is transported in the B-ISDN via the payload of the ATM cells. + +*Note 2* – As described in Recommendations I.432 and I.211, the maximum service bit rate at the 155.52 Mbit/s interface will be less than 135.631 Mbit/s. The maximum bit rate at the 622.08 Mbit/s is for further study. The actual value depends on the capacity required by signalling, operation, administration and maintenance (OAM), and ATM adaptation overheads (for further study). Also, granularity of the actual service bit rates offered by the network is contained in the appropriate I-Series Recommendations. + +Variable bit rate means that the peak bit rate as information transfer rate attribute value is not necessarily equal to the mean bit rate at the S/T reference point. Actual rate may be lower than peak bit rate. The characteristics are determined by the ATM connection. + +*Note 3* – Exact values for these attributes are contained in appropriate Q- and I-Series Recommendations. + +## ANNEX B + +(to Recommendation F.812) + +### Alphabetical list of abbreviations used in this Recommendation + +| | | +|--------|----------------------------------------------------------| +| AAL | ATM adaptation layer | +| ATM | Asynchronous transfer mode | +| B-ISDN | Broadband aspects of integrated services digital network | +| CAD | Computer aided design | +| CL | Connectionless | +| CL-PDU | Connectionless protocol data unit | +| CO | Connection oriented | +| LAN | Local area network | +| PDU | Protocol data unit | +| PRM | Protocol reference model | +| QOS | Quality of service | +| UNI | User-network interface | \ No newline at end of file diff --git a/marked/F/T-REC-F.813-199502-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.813-199502-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..7e86be364c2e70dc0688295c12b1f0dfde871be1 --- /dev/null +++ b/marked/F/T-REC-F.813-199502-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:9f5a9bf4a6fdd6b2b1432e4a58154012788a8fe0b6a49989a97624d32d6d507c +size 8198 diff --git a/marked/F/T-REC-F.813-199502-I_PDF-E/2ee59e629035d641140e55f4d215b0d7_img.jpg b/marked/F/T-REC-F.813-199502-I_PDF-E/2ee59e629035d641140e55f4d215b0d7_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..1ca6b65979b1371e508b2237090436a65facb7d7 --- /dev/null +++ b/marked/F/T-REC-F.813-199502-I_PDF-E/2ee59e629035d641140e55f4d215b0d7_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:e8d88afb548a1ae205a58aed5f91f8a301ef5c25be3817988c6e2b96345d0c21 +size 29830 diff --git a/marked/F/T-REC-F.813-199502-I_PDF-E/33a8f3f01dfa8bce75d23017855a13c5_img.jpg b/marked/F/T-REC-F.813-199502-I_PDF-E/33a8f3f01dfa8bce75d23017855a13c5_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e04b04c6bc006bb7f2e8a2cb5e4120ac3b468a6e --- /dev/null +++ b/marked/F/T-REC-F.813-199502-I_PDF-E/33a8f3f01dfa8bce75d23017855a13c5_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:bc30eaa4823ca0c67ef19506998b867f0a6d127670f4c8edaa989806328422ba +size 72959 diff --git a/marked/F/T-REC-F.813-199502-I_PDF-E/562f471e8153729557e6a4ee6343c32c_img.jpg b/marked/F/T-REC-F.813-199502-I_PDF-E/562f471e8153729557e6a4ee6343c32c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..2699852351790ceee48b6e49c8182972a2551b79 --- /dev/null +++ b/marked/F/T-REC-F.813-199502-I_PDF-E/562f471e8153729557e6a4ee6343c32c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:9f38f4b9a377513ba6885535461a12d42d9518fb4008aabf99ba6bfa5bc3e462 +size 46700 diff --git a/marked/F/T-REC-F.813-199502-I_PDF-E/7e670a2b556b53ea9002dfff3a420e08_img.jpg b/marked/F/T-REC-F.813-199502-I_PDF-E/7e670a2b556b53ea9002dfff3a420e08_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..74462e2a748a435231689033ab6bbbc63ab29211 --- /dev/null +++ b/marked/F/T-REC-F.813-199502-I_PDF-E/7e670a2b556b53ea9002dfff3a420e08_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8bd7d9ecd9a9d8420e9cfc24d42d75efc777a39307a0821d533484cc93127edb +size 33802 diff --git a/marked/F/T-REC-F.813-199502-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg b/marked/F/T-REC-F.813-199502-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..8c1acb8034f9ffc6a6789a6983dae086ace82460 --- /dev/null +++ b/marked/F/T-REC-F.813-199502-I_PDF-E/cfef993dcc8fb513de79eb1f93cf26ae_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:578c63f9c0592ea3bcecf4c72b47280e4b48b9bef959b9c33a2f7d334fe6ecd2 +size 14372 diff --git a/marked/F/T-REC-F.813-199502-I_PDF-E/raw.md b/marked/F/T-REC-F.813-199502-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..2960e0f841a900d5d6ba1ca37bdbf506a843cc11 --- /dev/null +++ b/marked/F/T-REC-F.813-199502-I_PDF-E/raw.md @@ -0,0 +1,684 @@ + + +![ITU logo: A globe with a lightning bolt and the letters ITU.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: A globe with a lightning bolt and the letters ITU. + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +**F.813** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +(02/95) + +**OPERATIONS AND QUALITY OF SERVICE +ISDN SERVICES** + +--- + +**VIRTUAL PATH SERVICE FOR RESERVED +AND PERMANENT COMMUNICATIONS** + +**ITU-T Recommendation F.813** + +(Previously "CCITT Recommendation") + +--- + +# FOREWORD + +The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). + +ITU-T Recommendation F.813 was prepared by ITU-T Study Group 1 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 21st of February 1995. + +--- + +# NOTE + +In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# CONTENTS + +| | Page | +|-------------------------------------------------|-------------| +| 1 Definition ..... | 1 | +| 2 Description ..... | 1 | +| 2.1 General description ..... | 1 | +| 2.2 Specific terminology ..... | 2 | +| 2.3 Abbreviations ..... | 3 | +| 3 Procedures ..... | 3 | +| 3.1 Provision and withdrawal ..... | 3 | +| 3.2 Normal procedures ..... | 6 | +| 3.3 Exceptional procedures ..... | 10 | +| 4 Interworking possibilities ..... | 10 | +| Annex A – Attributes and values ..... | 10 | +| A.1 Information transfer mode ..... | 10 | +| A.2 Information transfer rate ..... | 11 | +| A.3 Information transfer capability of VP ..... | 11 | +| A.4 Structure of VP ..... | 11 | +| A.5 Establishment of communication ..... | 11 | +| A.6 Symmetry of VP ..... | 11 | +| A.7 Communication configuration ..... | 11 | +| A.8 Access channels and rates ..... | 11 | +| A.9 Access protocols ..... | 11 | +| A.10 Supplementary services provided ..... | 12 | +| A.11 QOS of VP ..... | 12 | +| A.12 Interworking possibilities ..... | 12 | +| A.13 Operational and commercial aspects ..... | 12 | +| Annex B – Normative references ..... | 12 | +| Annex C – Reference configuration ..... | 13 | + +# **SUMMARY** + +This Recommendation defines stage one of the broadband virtual path service for reserved and permanent communications (BVPS) for the public broadband integrated services digital network (B-ISDN). + +This Recommendation does not specify the additional requirements where the service is provided to the user via a telecommunication network that is not the B-ISDN, but does not preclude requirements for interworking between other networks and the B-ISDN. + +The BVPS allows the transfer of unrestricted information between user-to-network reference points (UNRPs). + +# **VIRTUAL PATH SERVICE FOR RESERVED AND PERMANENT COMMUNICATIONS** + +*(Geneva, 1994)* + +# **1 Definition** + +According to Recommendation I.130 [4], this Recommendation defines stage one of the Broadband Virtual Path Service for reserved and permanent communications (BVPS) for the public Broadband Integrated Services Digital Network (B-ISDN). + +The BVPS allows the transfer of unrestricted information between User-to-Network Reference Points (UNRPs). In the B-ISDN, the UNRP is $T_B$ . It does not preclude the applicability of the BVPS to $S_B$ . + +The establishment of communication is either reserved or permanent. + +The provision of the BVPS is based on ATM Virtual Path (VP) connections in the B-ISDN (see Recommendation I.340 [10]). + +This Recommendation applies to stage two and stage three ITU-T Recommendations (see Recommendation I.130 [4] for the BVPS). + +Charging Principles are outside the scope of this Recommendation, but could be contained in the appropriate ITU-T Recommendation(s). + +# **2 Description** + +## **2.1 General description** + +The BVPS permits communication in both directions between two users in a point-to-point configuration. + +The provision of the BVPS is based on VP connections in the B-ISDN. + +Several VPs can be multiplexed at a specific UNI (up to 256 VP can be allocated at the UNI of the B-ISDN according to Recommendation I.361 [12]). + +The physical bit rate at the UNRP is defined by the existing UNIs according to Recommendation I.432 [14]. + +The parameter Peak Cell Rate (PCR) is associated with each VP. + +A communication can be established in two different modes: either permanent or reserved (for non-periodic and periodic use). + +In permanent establishment of communication, the subscriber can negotiate with the Service Provider (SP) any value of the PCR that is available at the UNRP and agreed by the SP. + +In reserved establishment of communication, the subscriber can negotiate with the SP any value of the maximum bandwidth that is available at the UNI and agreed by the SP. Then, the manager can negotiate with the Service Management Entity (SME) any available value of the PCR within the subscribed maximum bandwidth. + +The SP shall enforce user cells according to the Peak Cell Rate (PCR) reference algorithm specified in Recommendation I.371 [13]. According to the PCR reference algorithm in Recommendation I.371 [13], the cell conformance is defined with reference to the pair $(T, \tau)$ where $T$ is the Peak Emission Interval (PEI) and $\tau$ is the Cell Delay Variation (CDV) tolerance. The SP shall provide the user the values of PEI and CDV tolerance that are part of the traffic contract. + +User information transfer is unrestricted. It is structured in ATM cells. The cell format is of the User-to-Network Interface (UNI) type as defined in 2.2/I.361 [12]. The bit rate of the source can be CBR or VBR. The effective availability of the constant value of PCR (greater than zero) for a VP corresponds to a time slot as defined within this Recommendation. + +In permanent establishment of communication, periodic or non-periodic VPs are possible. A permanent VP, either periodic or non-periodic, is subscribed providing all the parameters necessary for its establishment. A permanent VP is registered at subscription. + +In reserved establishment of communication, periodic or non-periodic VPs are possible. The subscriber subscribes to the BVPS in reserved establishment of communication providing general service parameters (see 3.1.3), e.g. listing only the users involved in the use of the BVPS and the maximum number of VPs that can be established among these users in any configuration at the same time. Every reserved VP, either periodic or non-periodic, is established after a registration procedure. During this phase the parameters of the VP between the two involved users are negotiated. + +## 2.2 Specific terminology + +For the purpose of this Recommendation, the following definitions apply: + +2.2.1 **integrated services digital network:** See 2.3/I.112 [2], definition 308. + +2.2.2 **broadband:** See 2.1/I.113 [3], definition 101. + +2.2.3 **service, telecommunication service:** See 2.2/I.112 [2], definition 201. + +2.2.4 **asynchronous transfer mode:** See 2.2/I.113 [3], definition 204. + +2.2.5 **virtual channel:** See 4/I.113 [3], definition 401. + +2.2.6 **virtual channel identifier:** A number that identifies locally a specific Virtual Channel (VC) at a UNI. + +2.2.7 **virtual path:** From the user's point of view, a virtual end-to-end connection that ensures unidirectional or bidirectional transport of ATM cells belonging to VCs that are associated by a common VPI. + +2.2.8 **virtual path identifier:** A number that identifies locally a specific VP at a UNI. + +2.2.9 **global virtual path identifier:** The Global Virtual Path Identifier (GVPI) identifies a specific VP. It is used by the Service Management Entity (SME) for the management of the complete VP. + +2.2.10 **service management entity:** The functional entity (SME) to which manager's VP registration requests, VP modification requests and interrogation requests are addressed (see Figure C.1). + +2.2.11 **service management reference point:** This reference point (SMRP) is defined between the SME and the manager (see Figure C.1). + +2.2.12 **subscriber:** The logic entity that subscribes to the BVPS. The subscriber shall declare one manager at most and one or more related users. + +2.2.13 **manager:** The functional entity authorised to perform through SMRP all the service management functions, including VP registration requests, VP modification requests and interrogation requests, on behalf of the users to which it is related at subscription time (see Figure C.1). + +2.2.14 **user:** The functional entity authorised to perform through UNRP all the User plane functions, including sending and receiving User Information (see Figure C.1). + +2.2.15 **user-to-network reference point:** This reference point (UNRP) is defined between the user and the ATM capabilities (see Figure C.1). It is equal to $T_B$ . This does not preclude the applicability of the BVPS to $S_B$ . + +2.2.16 **initiating manager:** The manager issuing a request to the SME. + +2.2.17 **involved manager:** The manager receiving a request issued by another initiating manager. + +2.2.18 **peak cell rate:** See Recommendation I.371 [13]. The PCR is expressed as an integer number of cell(s) per second. + +The network shall allocate the appropriate resources using the PCR value. There is no statistical multiplexing. + +**2.2.19 peak emission interval:** According to Recommendation I.371 [13], the PEI is the inverse of the PCR, i.e. PEI corresponds to the minimum time interval $T$ between two successive cells emission times, when these cells are emitted perfectly periodically by the user. + +**2.2.20 cell delay variation tolerance:** The CDV tolerance $\tau$ corresponds to the maximum time variation between a perfectly periodic cell stream emitted at period $T$ (see PEI definition) and the conforming user cell stream. + +**2.2.21 time slot:** The time interval between the activation and the following deactivation of a VP. The duration of an $i^{\text{th}}$ time slot $De_i$ is defined by $De_i = De_{\min} + M_i * P$ where $De_{\min}$ is the minimum duration of the time slot, $M_i$ is an integer and $P$ is a fixed duration of time. $De_{\min}$ and $P$ are service constants. + +## 2.3 Abbreviations + +For the purposes of this Recommendation, the following abbreviations are used: + +| | | +|--------|--------------------------------------------------------------------------| +| ATM | Asynchronous Transfer Mode | +| B-ISDN | Broadband Integrated Services Digital Network | +| BVPS | Broadband Virtual Path Service for reserved and permanent communications | +| CBR | Constant Bit Rate | +| CDV | Cell Delay Variation | +| GVPI | Global Virtual Path Identifier | +| NMRP | Network Management Reference Point | +| PCR | Peak Cell Rate | +| PEI | Peak Emission Interval | +| SME | Service Management Entity | +| SMRP | Service Management Reference Point | +| SP | Service Provider | +| UMRP | User Management Reference Point | +| UNI | User-to-Network Interface | +| UNRP | User-to-Network Reference Point | +| VBR | Variable Bit Rate | +| VC | Virtual Channel | +| VCI | Virtual Channel Identifier | +| VP | Virtual Path | +| VPI | Virtual Path Identifier | + +# 3 Procedures + +## 3.1 Provision and withdrawal + +### 3.1.1 General principles + +The BVPS is provided after arrangement with the SP. + +The BVPS permits either reserved or permanent establishment of communications between two UNIs. + +Subscriptions of reserved and permanent establishments of communications can coexist on the same UNI. + +The subscription states the maximum number $Nb_{\max}$ of VPs per UNI. According to Recommendation I.361 [12], the number of VPs available at the UNI is less than or equal to 256. Hence, $Nb_{\max}$ is evaluated taking these constraints into account. + +Provision and withdrawal processes are based on Figure 1. + +![Figure 1: Schedule 1. A timeline diagram showing four time points: t0, t1, t2, and t3. The timeline starts at t0, has a break between t1 and t2, and ends at t3. The interval between t1 and t3 represents the service availability period Da. The interval between t0 and t1 represents the notification time Ta.](2ee59e629035d641140e55f4d215b0d7_img.jpg) + +Diagram illustrating the timeline for Schedule 1. The timeline shows four time points: $t_0$ , $t_1$ , $t_2$ , and $t_3$ . The timeline starts at $t_0$ , has a break between $t_1$ and $t_2$ , and ends at $t_3$ . The interval between $t_1$ and $t_3$ represents the service availability period $D_a$ . The interval between $t_0$ and $t_1$ represents the notification time $T_a$ . + +$t_0$ Time at which subscription to the BVPS is requested + $t_1$ Time at which the BVPS is available + $t_2$ Time at which subscription to the BVPS is requested to be terminated + $t_3$ Time at which subscription to the BVPS is effectively terminated + +T0103410-94/d01 + +Figure 1: Schedule 1. A timeline diagram showing four time points: t0, t1, t2, and t3. The timeline starts at t0, has a break between t1 and t2, and ends at t3. The interval between t1 and t3 represents the service availability period Da. The interval between t0 and t1 represents the notification time Ta. + +FIGURE 1/F.813 + +#### **Schedule 1** + +The notification time $T_a = t_1 - t_0$ is necessary greater than or equal to a minimum time $T_{a\min}$ . + +The availability of service $D_a = t_3 - t_1$ corresponds to the duration of subscription. $D_a$ varies between the minimum duration of subscription $D_{a\min}$ and the maximum duration of subscription $D_{a\max}$ . If $t_3$ is not indicated $D_a$ is assumed equal to $D_{a\max}$ . + +The values of $T_{a\min}$ , $D_{a\min}$ and $D_{a\max}$ are fixed by the SP. + +### 3.1.2 Permanent establishment of communication + +The permanent establishment of communication is defined in Recommendation I.140 [5]. + +Each VP is available at the subscribed PCR during a period $D_a$ . + +The subscription is renewable per periods of $D_{a\min}$ . + +Either non-periodic or periodic VP can be subscribed. + +For a non-periodic VP, values of PCR and QOS are constant for the duration of subscription. + +For a periodic VP, the same values of PCR and QOS scheme are repeated within each period for the duration of the subscription. + +At the subscription, the SP and the subscriber negotiate the values of service parameters for each VP. + +For a non-periodic VP, 3.1.2.1 applies. + +For a periodic VP, 3.1.2.2 applies. + +The following parameters are defined per VP. + +#### 3.1.2.1 Non-periodic VP + +##### 3.1.2.1.1 Mandatory subscription parameters + +- users E.164 [1] numbers; +- subscription beginning time: $t_1$ ; +- symmetry: unidirectional, bidirectional symmetric or bidirectional asymmetric; +- PCR: in each direction for a bidirectional asymmetric VP. + +##### 3.1.2.1.2 Optional subscription parameters + +- subscription end time: $t_3$ ; +- values of VPIs (as a SP option); +- value of QOS: in each direction for a bidirectional asymmetric VP. + +#### 3.1.2.2 Periodic VP + +This subscription allows the specification of a period and of a number $N$ of time slots within the period (see Figure 2). The number $N$ of time slots shall be within 1 and $N_{max}$ (fixed by the SP). + +![Figure 2/F.813 Schedule 2: A timeline diagram showing a periodic Virtual Path subscription. The horizontal axis represents time, starting from t0. It shows multiple periods: Period 1, Period j, Period j+1, and a Last period. Within Period j+1, several time slots are defined: Time slot i, Time slot i+1, and Time slot i+2. Key time points are marked: TA1, TD1, TAi, TDi, TAi+1, TDi+1, TAi+2, TDi+2, TAN, and TDN. The subscription starts at t1 and ends at t2. A final time point t3 is also shown. A specific condition TDi = TAi+1 is highlighted where one slot ends as the next begins. Legend: TAi is the time of the i-th activation; TDi is the time of the i-th deactivation.](562f471e8153729557e6a4ee6343c32c_img.jpg) + +$TA_i$ Time at which the $i^{th}$ activation of the VP in the period is made + $TD_i$ Time at which the VP is deactivated for the $i^{th}$ time in the period + +Figure 2/F.813 Schedule 2: A timeline diagram showing a periodic Virtual Path subscription. The horizontal axis represents time, starting from t0. It shows multiple periods: Period 1, Period j, Period j+1, and a Last period. Within Period j+1, several time slots are defined: Time slot i, Time slot i+1, and Time slot i+2. Key time points are marked: TA1, TD1, TAi, TDi, TAi+1, TDi+1, TAi+2, TDi+2, TAN, and TDN. The subscription starts at t1 and ends at t2. A final time point t3 is also shown. A specific condition TDi = TAi+1 is highlighted where one slot ends as the next begins. Legend: TAi is the time of the i-th activation; TDi is the time of the i-th deactivation. + +FIGURE 2/F.813 + +#### Schedule 2 + +For each time slot, the values of PCR and QOS can be specified independently by the values they have in other time slots. + +If a deactivation is simultaneous to an activation ( $TD_i = TA_{i+1}$ ), this corresponds to a PCR modification (without a jump to a PCR zero) ensuring the continuity of the BVPS. + +The VP set-up shall be completed at time $t_1$ . + +The VP release shall be initiated: + +- from an including time $t_2$ if an anticipated deactivation is requested by the subscriber; or +- from an including time $TD_N$ of the last period. + +##### 3.1.2.2.1 Mandatory subscription parameters + +- users E.164 [1] numbers; +- subscription beginning time: $t_1$ ; +- period: day, week or month; +- activation time for each time slot: $TA_i$ (with $1 \leq i \leq N$ ); +- deactivation time for each time slot: $TD_i$ (with $1 \leq i \leq N$ ); +- symmetry: unidirectional, bidirectional symmetric or bidirectional asymmetric; +- PCR for each time slot: in each direction for a bidirectional asymmetric VP. + +##### 3.1.2.2.2 Optional subscription parameters + +- subscription end time: $t_3$ that corresponds to the end time of the last period; +- values of VPIs (as a SP option); +- value of QOS for each time slot: in each direction for a bidirectional asymmetric VP. + +### 3.1.3 Reserved establishment of communication + +The definition of the reserved establishment of communication is based on Recommendation I.140 [5]. + +The manager obtains at time $t_1$ (see Figure 1) the authorisation to use the BVPS, i.e. to issue registration request to the SME to reserve VP(s). + +Two types of reservations are possible (as described in 3.2.1.2.1 and 3.2.1.2.2): + +- non-periodic reservation; +- periodic reservation. + +The following parameters shall be specified at subscription time as mandatory subscription parameters: + +- manager identifier; +- users E.164 [1] numbers of the users controlled by the manager; +- subscription beginning time: $t_1$ ; +- subscription end time: $t_3$ ; +- maximum number $Nb_{max}$ of VPs per UNRP; +- maximum bandwidth available at each UNRP. + +The subscription is renewable. + +An anticipated BVPS withdrawal request may be issued by the manager at any time $t_2$ before foreseen time $t_3$ . + +## 3.2 Normal procedures + +### 3.2.1 Activation and deactivation + +The activation procedure leads to the effective availability of the requested PCR (greater than zero) for the VP. + +The deactivation procedure leads to the PCR value equal to zero for the VP. + +If a deactivation is simultaneous to an activation ( $TD_i = TA_{i+1}$ ), this corresponds to a PCR modification (without a jump to a PCR zero) ensuring the continuity of the BVPS. + +The times of the activation and deactivation depend on the establishment of communication fixed at the subscription. + +#### 3.2.1.1 Permanent establishment of communication + +A non-periodic VP is available at the subscribed PCR for all the duration of subscription. According to Figure 1, activation occurs at time $t_1$ and deactivation at time $t_3$ . + +For a periodic VP, the activation (respectively deactivation) procedure shall be repeated for each time slot at $TA_i$ (respectively $TD_i$ ). + +#### 3.2.1.2 Reserved establishment of communication + +Two types of deactivation are possible: + +- after the foreseen duration, the SP deactivates the VP at time $TD$ for an non-periodic reservation or at each time $TD_i$ for a periodic reservation; +- after the manager request at time $RD$ (non-periodic reservation) or at any time $RD_i$ (periodic reservation). + +The activation and deactivation procedures are based on the exchange of appropriate information between the manager and the user. + +NOTE – Management procedures are outside the scope of this Recommendation. + +##### 3.2.1.2.1 Non-periodic reservation + +Figure 3 presents the schedule **Error! Bookmark not defined.** that applies to this case. + +The activation (respectively deactivation) procedure occurs only once at $TA$ (respectively $TD$ ). + +![Timeline diagram for Schedule 3 showing a single time slot. The timeline is a horizontal arrow with vertical markers. From left to right, the markers are: t0, t1, RR, TR, TA, RD, TD, t2, and t3. A horizontal bracket labeled 'Time slot' spans from TA to TD. Dotted lines connect t1 to RR and TD to t2. The reference code T0103430-94/d03 is at the bottom right.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +Timeline diagram for Schedule 3 showing a single time slot. The timeline is a horizontal arrow with vertical markers. From left to right, the markers are: t0, t1, RR, TR, TA, RD, TD, t2, and t3. A horizontal bracket labeled 'Time slot' spans from TA to TD. Dotted lines connect t1 to RR and TD to t2. The reference code T0103430-94/d03 is at the bottom right. + +- RR Time at which the request for the reservation of a VP is made +- TR Time at which the reservation of a VP is made +- TA Time at which the VP is activated +- RD Time at which the request for the deactivation of the VP is made +- TD Time at which the VP is deactivated + +FIGURE 3/F.813 +Schedule 3 + +##### 3.2.1.2.2 Periodic reservation + +Figure 4 presents the detailed schedule **Error! Bookmark not defined.** that applies to this case. + +![Timeline diagram for Schedule 4 showing periodic reservations. The timeline is a horizontal arrow with vertical markers. From left to right, markers include: t0, t1, RR, TR, TA1, RD1, TD1, TAi, RDi, TDi = TAi+1, RDi+1, TDi+1, TAi+2, RDi+2, TDi+2, TAN, RDN, TDN, t2, and t3. Three 'Time slot' intervals are indicated: Time sloti, Time sloti+1, and Time sloti+2. Two 'Period' intervals are marked: Periodj and Periodj+1. The reference code T0103440-94/d04 is at the bottom right.](7e670a2b556b53ea9002dfff3a420e08_img.jpg) + +Timeline diagram for Schedule 4 showing periodic reservations. The timeline is a horizontal arrow with vertical markers. From left to right, markers include: t0, t1, RR, TR, TA1, RD1, TD1, TAi, RDi, TDi = TAi+1, RDi+1, TDi+1, TAi+2, RDi+2, TDi+2, TAN, RDN, TDN, t2, and t3. Three 'Time slot' intervals are indicated: Time sloti, Time sloti+1, and Time sloti+2. Two 'Period' intervals are marked: Periodj and Periodj+1. The reference code T0103440-94/d04 is at the bottom right. + +- RR Time at which the request for reservation of a VP is made +- TR Time at which the reservation of a VP is made +- TAi Time at which the ith activation of the VP in the period is made +- RDi Time at which the anticipated request for the deactivation (corresponding to the ith activation in the period) of the VP is made +- TDi Time at which the VP is deactivated for the ith time in the period + +FIGURE 4/F.813 +Schedule 4 + +The activation (respectively deactivation) procedure shall be repeated for each time slot at TAi (respectively TDi). + +If a deactivation is simultaneous to an activation ( $TD_i = TA_{i+1}$ ), this corresponds to a PCR modification (without a jump to a PCR zero) ensuring the continuity of the BVPS. + +The VP set-up shall be completed at time TA1 of the first period. + +The VP release shall be initiated: + +- a) from an including time t2 if an anticipated deactivation is requested by the manager; or +- b) from an including time TDN of the last period. + +### 3.2.2 Registration + +For the permanent establishment of communication, the registration applies at subscription and is managed by the SP. + +For the reserved establishment of communication, the following procedures apply. + +If a manager requests the registration of a VP spanning between two users both related to it, the following procedure shall be performed: + +- a) The manager issues the registration request providing the SME with the parameter values for the VP. +- b) The SME shall issue either a positive notification (including the values of GVPI, VPIs, PEI and CDV tolerance, see 2.1) or a negative notification. In the former case, the VP shall be established as requested. If the SME issues a negative notification, no VP is established. The SME can propose along with the negative notification new parameter values that would have made the request viable. + +If a manager (initiating manager) requests the registration of a VP spanning between two users, one of which relates to a different manager (involved manager), the following procedure shall be performed: + +- a) The initiating manager issues the registration request providing the SME with the parameter values for the VP. +- b) The SME shall issue either a negative notification to the initiating manager or a notification to the involved manager reporting the parameter values of the requested VP. In the former case, the SME can propose along with the negative notification new parameter values that would have made the request viable. If the SME issues a negative notification, the procedure stops. +- c) The involved manager shall issue to the SME either a positive notification or a negative notification. In the latter case, the involved manager can provide along with the notification new parameter values that would have made the request viable. +- d) If the involved manager has issued a positive notification, the SME shall issue a positive notification (including the values of GVPI, VPI, PEI and CDV tolerance, see 2.1) to both managers. The SME shall establish the VP as requested. If the involved manager has issued a negative notification, the SME shall issue a negative notification to the initiating manager, along with the parameter values proposed by the involved manager with the notification, if provided. + +#### 3.2.2.1 Non-periodic VP + +##### 3.2.2.1.1 Mandatory registration parameters + +The manager shall provide the following parameters: + +- a) reservation type: non-periodic; +- b) users E.164 [1] numbers; +- c) activation time: TA; +- d) deactivation time: TD; +- e) symmetry: unidirectional, bidirectional symmetric or bidirectional asymmetric; +- f) PCR: in each direction for a bidirectional asymmetric VP. + +##### 3.2.2.1.2 Optional registration parameters + +- a) value of VPI per user (as a SP option); +- b) value of QOS, in each direction for a bidirectional asymmetric VP. + +#### 3.2.2.2 Periodic VP + +##### 3.2.2.2.1 Mandatory registration parameters + +The manager shall provide the following parameters: + +- a) reservation type: periodic; +- b) users E.164 [Error! Bookmark not defined.] numbers; + +- c) period; day, week or month; +- d) beginning time of the first period; +- e) end time of the last period; +- f) activation time for each time slot: $TA_i$ (with $1 \leq i \leq N$ ); +- g) deactivation time for each time slot: $TD_i$ (with $1 \leq i \leq N$ ); +- h) symmetry: unidirectional, bidirectional symmetric or bidirectional asymmetric; +- i) PCR: for each time slot, in each direction for a bidirectional asymmetric VP. + +##### 3.2.2.2.2 Optional registration parameters + +- a) value of VPI per user (as a SP option); +- b) value of QOS for each time slot, in each direction for a bidirectional asymmetric VP. + +### 3.2.3 Registration modification + +In permanent establishment of communication, the registration modification corresponds to a subscription modification and is managed by the SP. + +In reserved establishment of communication, the manager has the following capabilities (see Note): + +- a) request for modification of one or more parameter values of one registered VP; +- b) request for cancellation of a VP or of a particular time slot for a periodic reservation. + +If a manager requests the registration modification of a VP spanning between two users both related to it, the following procedure shall be performed: + +- a) The manager issues the registration modification request providing the SME with the GVPI and the list of parameters to be modified with the proposed parameter values. +- b) The SME shall issue either a positive notification (including the values of PEI and CDV tolerance if the PCR is modified, see 2.1) or a negative notification. In the former case, the VP shall be modified as requested. If the SME issues a negative notification, the VP is not modified. The SME can propose along with the negative notification new parameter values that would have made the request viable. + +If a manager (initiating manager) requests the registration modification of a VP spanning between two users, one of which relates to a different manager (involved manager), the following procedure should be performed: + +- a) The initiating manager issues the registration modification request providing the SME with the GVPI and the list of parameter to be modified with the proposed parameter values. +- b) The SME shall issue either a negative notification to the initiating manager or a notification to the involved manager reporting the list of parameters to be modified and the proposed parameter values of the VP. In the former case, the SME can propose along with the negative notification new modified parameter values that would have made the request viable. If the SME issues a negative notification, the procedure stops. +- c) The involved manager shall issue to the SME either a positive notification or a negative notification. In the latter case, the involved manager can provide along with the notification new parameter values that would have made the request viable. +- d) If the involved manager has issued a positive notification, the SME shall issue a positive notification (including the values of PEI and CDV tolerance if the PCR is modified, see 2.1) to both managers. The SME shall modify the VP as requested. If the involved manager has issued a negative notification, the SME shall issue a negative notification to the initiating manager, along with the modified parameter values proposed by the involved manager with the notification, if provided. + +NOTE – Management operations are out of the scope of this Recommendation. + +### **3.2.4 Erasure** + +The erasure procedure leads to the deletion of all the data related to the VP in the SME and is managed by the SP. + +For the permanent establishment of communication, the erasure occurs at the same time as the withdrawal. + +For the reserved establishment of communication, the erasure occurs at the same time as the release of the VP. + +### **3.2.5 Invocation and operation** + +The BVPS is automatically invoked when the user provides user information inside conforming ATM cells during a time slot. The conforming ATM cells are defined according to Recommendation I.371 [13]. + +## **3.3 Exceptional procedures** + +The exceptional procedures need further studies. + +# **4 Interworking possibilities** + +The interworking with other broadband services shall be ensured where applicable. + +# **Annex A** + +## **Attributes and values** + +(This annex forms an integral part of this Recommendation) + +The attributes and possible values refer to Recommendation I.140 [5]. + +## **A.1 Information transfer mode** + +ATM. + +### **A.1.1 Connection mode** + +Connection-oriented. + +### **A.1.2 Traffic type of VP** + +The traffic of the source can have a CBR or a VBR. However, the cell rate is less than or equal to the PCR of the VP. + +### **A.1.3 End-to-end timing of VP** + +Not required. + +### **A.1.4 VCI transparency (for VP services)** + +The VCI is transparent for the BVPS: the BVPS does not modify the VCI field but imposes some constraints on the allocation of this field. + +Four of the first sixteen channels are specified in Recommendation I.361 [12]. VCI = 0 ... 3 and VCI = 5 ... 15 shall not be used by the user. VCI = 4 may be used by the user for end-to-end F4 flow (see Recommendation I.610 [15]). + +## **A.2 Information transfer rate** + +The rate of a VP is a PCR. + +If a user subscribes several VPs, the PCR of aggregated VPs is defined as the addition of each PCR for a single VP. + +Any PCR value supported by the UNIs to be interconnected can be allocated. + +## **A.3 Information transfer capability of VP** + +Unrestricted digital information. + +## **A.4 Structure of VPs** + +Cell sequence integrity. + +## **A.5 Establishment of communication** + +- a) permanent; +- b) reserved. + +## **A.6 Symmetry of VP** + +- a) unidirectional; +- b) bidirectional symmetric; +- c) bidirectional asymmetric. + +## **A.7 Communication configuration** + +Point-to-point (see Recommendation I.210 [7]). + +## **A.8 Access channels and rates** + +The types of UNIs available are defined in Recommendation I.432 [14]. + +### **A.8.1 For user information** + +The transfer of user information is ensured via one of the UNIs mentioned in A.8. + +#### **A.8.1.1 Number of channels** + +Up to and including 256, but the maximum number available for each user $Nb_{max}$ is fixed at the subscription. + +#### **A.8.1.2 Type of channels** + +VP. + +### **A.8.2 For signalling** + +Not applicable. + +## **A.9 Access protocols** + +### **A.9.1 Information access protocol physical layer** + +See Recommendation I.432 [14]. + +### **A.9.2 Information access protocol ATM layer** + +See Recommendations I.361 [12] and I.150 [6]. + +## **A.10 Supplementary services provided** + +The provision of supplementary services is outside the scope of this Recommendation. + +## **A.11 QOS of VPs** + +The QOS is based on the performance parameters defined in Recommendation I.356 [11]. + +## **A.12 Interworking possibilities** + +The interworking with other broadband services shall be ensured where applicable. + +## **A.13 Operational and commercial aspects** + +These aspects are out of the scope of this Recommendation. + +# **Annex B** + +## **Normative references** + +(This annex forms an integral part of this Recommendation) + +These Recommendations incorporate, by dated or undated References, provisions from other publications. The normative References are cited at the appropriate places in the text and the publications are listed hereafter. For dated References, subsequent amendments to, or revision of any publications apply to this Recommendation only when incorporated in it by amendment or revision. For undated References the latest edition of the publication referred applies. + +- [1] CCITT Recommendation E.164 (1991), *Numbering plan for the ISDN era*. +- [2] ITU-T Recommendation I.112 (1993), *Vocabulary of terms for ISDNs*. +- [3] ITU-T Recommendation I.113 (1993), *Vocabulary of terms for broadband aspects of ISDN*. +- [4] ITU-T Recommendation I.130 (1988), *Method for the characterization of the telecommunication services supported by an ISDN and network capabilities of an ISDN*. +- [5] ITU-T Recommendation I.140 (1993), *Attribute technique for the characterization of telecommunication services supported by an ISDN and network capabilities of an ISDN*. +- [6] ITU-T Recommendation I.150 (1993), *B-ISDN asynchronous transfer mode functional characteristics*. +- [7] ITU-T Recommendation I.210 (1993), *Principles of telecommunication services supported by an ISDN and the means to describe them*. +- [8] ITU-T Recommendation I.211 (1993), *B-ISDN service aspects*. +- [9] ITU-T Recommendation I.311 (1993), *B-ISDN general network aspects*. +- [10] CCITT Recommendation I.340 (1988), *ISDN connections types*. +- [11] ITU-T Recommendation I.356 (1993), *B-ISDN ATM layer cell transfer performance*. +- [12] ITU-T Recommendation I.361 (1993), *B-ISDN ATM layer specification*. +- [13] ITU-T Recommendation I.371 (1993), *Traffic control and congestion control in B-ISDN*. +- [14] ITU-T Recommendation I.432 (1993), *B-ISDN user-network interface – Physical layer specification*. +- [15] ITU-T Recommendation I.610 (1993), *B-ISDN operation and maintenance principles and functions*. +- [16] CCITT Recommendation M.3010 (1992), *Principles for a telecommunication management network*. + +# Annex C + +## Reference configuration + +(This annex forms an integral part of this Recommendation) + +This reference configuration defines the reference points between the SP and the users on the user plane and on the management plane. It means that this configuration also describes the functional entities which are separated by the reference points. It is noted that the reference configuration does not specify an implementation of functional entities. + +In Figure C.1 the subscriber A is associated to the manager $M(A)$ and the users $U(A)_1$ , $U(A)_i$ and $U(A)_n$ , and the subscriber B is associated to the manager $M(B)$ and the user $U(B)$ . SMRP corresponds to the x reference point defined in Recommendation M.3010 [16] and UNRP corresponds to $T_B$ reference point defined in Recommendation I.432 [14]. + +![Diagram of the reference configuration showing management and user planes with various entities and reference points.](33a8f3f01dfa8bce75d23017855a13c5_img.jpg) + +The diagram illustrates the reference configuration for a network, divided into two horizontal planes by a dash-dot line: the 'Management plane' above and the 'User plane' below. In the Management plane, there are two circular nodes, $M(A)$ on the left and $M(B)$ on the right, both connected to a central oval node labeled 'SME'. The connections between $M(A)$ and SME, and between SME and $M(B)$ , are marked with 'SMRP' reference points. A horizontal dash-dot line labeled 'UMRP' passes through the management plane. In the User plane, $M(A)$ is connected via curved lines to three rectangular nodes representing users: $U(A)_1$ , $U(A)_i$ , and $U(A)_n$ . $M(B)$ is connected to a rectangular node $U(B)$ . All user nodes for $U(A)$ are connected to a central large circle containing 'VP transfer capabilities' and 'ATM transfer capabilities'. The connections between these user nodes and the central capabilities node are marked with 'UNRP' reference points. A vertical line connects $M(B)$ to $U(B)$ through the UMRP line. A horizontal dash-dot line labeled 'NMRP' passes through the central capabilities node. 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TELECOMMUNICATION UNION + +**CCITT** + +THE INTERNATIONAL +TELEGRAPH AND TELEPHONE +CONSULTATIVE COMMITTEE + +**F.89** + +(08/92) + +**TELEGRAPH AND MOBILE SERVICES +OPERATIONS AND QUALITY OF SERVICE** + +--- + +**STATUS ENQUIRY FUNCTION IN +THE INTERNATIONAL TELEX SERVICE** + +**Recommendation F.89** + +--- + +![CCITT logo: A globe with the letters CCITT.](84a1d09fb489061482111515543b60dc_img.jpg) + +CCITT logo: A globe with the letters CCITT. + +Geneva, 1992 + +# FOREWORD + +The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988). + +Recommendation F.89 was prepared by Study Group I and was approved under the Resolution No. 2 procedure on the 4th of August 1992. + +## --- CCITT NOTES + +- 1) In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized private operating agency. +- 2) A list of abbreviations used in this Recommendation can be found in Annex A. + +© ITU 1992 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +# **STATUS ENQUIRY FUNCTION IN THE INTERNATIONAL TELEX SERVICE** + +(1992) + +## **1 Introduction** + +This Recommendation describes the facilities and operational requirements of a status enquiry function (SEF) within the international telex service which enables a subscriber of the international telex service to seek and be provided with information concerning the status of a message previously deposited into an interworking function (IWF) for the purpose of transmission to a user of another service on either a store-and-forward basis or store-and-retrieve basis. In some interworking cases, the SEF may also provide a message cancellation facility. + +## **2 Scope** + +The provisions of this Recommendation are limited to enquiries concerning messages handled by an IWF in accordance with the relevant F.80-Series Recommendations. Status enquiry in respect of messages deposited into a telex store and forward unit (SFU) for delivery to the international telex service are handled in accordance with Recommendation F.72. The provisions of this Recommendation should be applied to future implementations and, as far as possible, to existing implementations of IWF and SFU, in the latter case as an alternative to the provisions of Recommendation F.72 in respect of status enquiry. + +## **3 Area of application** + +3.1 A status enquiry function is relevant in those interworking configurations which implement message delivery on a store-and-forward basis or store-and-retrieve basis, namely: + +- telex to telex (see Recommendations F.72/U.80/U.81); +- telex to teletex (see Recommendations F.81/F.201/U.201); +- telex to facsimile Group 3 (see Recommendations F.87/U.207); +- telex to interpersonal messaging (IPM) (see Recommendations F.85/F.421/U.204); +- telex to videotex (see Recommendations F.86/U.206); +- telex to INMARSAT C (see Recommendations F.127/U.208). + +3.2 In the context of this Recommendation, “DELIVERED” should be interpreted in accordance with Table 1/F.89. + +## **4 Service provided by SEF** + +### **4.1 *Information about message status*** + +4.1.1 The SEF should provide information about the status of messages for which message reference information had been provided at the time of message deposit in accordance with the relevant F-Series Recommendations. The receipt of message reference information generally will have been effected by the use of a two-stage access, using either the input transaction accepted for delivery (ITD) or input message acknowledgement (IMA) procedure. It should be noted that message reference information is also provided in the particular case of single-stage access from the international telex service to the INMARSAT Standard-C system in accordance with Recommendation F.127. + +Message status information may also be provided through the use of a journal facility, which may also be applied in the single-stage access case where there may be an absence of supporting message reference information. + +TABLE 1/F.89 + +#### **Definition of message “delivery”** + +| International Telex Service to: | Relevant Recommendation | Message delivered to: | +|---------------------------------|----------------------------------|--------------------------------------| +| Teletex | F.81 (F.201)/U.201 | Memory of addressed teletex terminal | +| Interpersonal messaging | F.85 a) (F.421)/U.204 | User Agent of IPM service user | +| Videotex | F.86/U.206 | Mailbox of videotex user | +| Group 3 Fax | F.87/U.207 | Group 3 facsimile terminal | +| INMARSAT “C” | F.127/U.208 | MES terminal equipment | +| International telex service | F.72/U.80/U.81 | Destination telex terminal | + +a) Blue Book Recommendation F.75 has been renumbered to F.85. + +4.1.2 Notwithstanding the fact that the IWF may delete the text of a message after successful delivery, or after all delivery attempts have been completed, the status of a message should be available to the SEF for at least 72 hours after message acceptance. + +4.1.3 The protocol to be followed between the calling telex subscriber and the SEF is described in Recommendation U.220. + +### 4.2 *Outline of status enquiry function* + +4.2.1 In the case of two-stage IWF, a status enquiry capability can be provided when a message reference has been provided by the IWF. Such a reference should be provided on a per-message, per-address basis. + +4.2.2 Message status information may also be provided in the absence of message reference information through the use of the JOURNAL or LOG facility, in both the single- and two-stage cases. + +4.3 For security reasons, status information should only be provided to the originator of the message, based on an analysis of the received answerback plus the message reference, independent of whether the answerback is processable or not (in accordance with Recommendation U.74). + +4.4 The basic service features to be provided should allow for the provision of information on the stage reached in the message delivery process, as well as the ability to cancel a message. Other features may be provided on a national basis. + +4.5 Access to an SEF may be provided in one or both of the following ways: + +- by use of an access number different to that used for message deposit; +- by use of an access number similar to that used for message deposit. + +In the case of access to the IWF/SEF using a number similar to that for message deposit, provision should be made to accept the input of an address and message, for subsequent forward transmission to the addressee in the normal way, as part of a follow-on call subsequent to or in advance of a status enquiry/cancel session. + +4.6 Access to the SEF should follow normal telex procedures and the calling telex answerback should be retrieved in accordance with Recommendation S.23. The provision of additional information by the SEF at this stage of the call should be done in accordance with the relevant U-Series signalling Recommendations. + +4.7 The SEF should compare the received telex answerback and message reference with that provided at message deposit. The procedures to be used are described in Recommendation U.220. See also § 4.8. + +4.8 The SEF should not process a service request from the telex subscriber which did not follow the format prescribed in §§ 4.10 and 4.11 and would return the code format error (**FMT**) and clear the connection. + +4.9 Where no status information is on file for the caller, or the caller is not the originator of the message, the SEF should reply with the text NO MESSAGE and clear the connection. + +### 4.10 *Enquiry concerning message delivery* + +4.10.1 The calling telex subscriber should request the information by inputting the following sequence: + +ENQ + or +ENQUIRY + + +where ENQ (or ENQUIRY) is the service request identifier for status information, and is the message reference assigned by the IWF at message deposit, both fields being separated by a space character. + +Message reference information may contain both alpha and numeric parts. Where the message reference information provided at message deposit consists of a date/time sequence coupled with a reference number, the input of the message reference number alone should be tolerated by the SEF. + +4.10.2 If a valid request has been received, the SEF should respond within three seconds with one of the following replies: + +- a) DELIVERED if message has already been successfully delivered; +- b) NOT YET DELIVERED if message delivery has not yet commenced, or is still in the retry cycle, or is in the process of being delivered; +- c) NOT DELIVERED if all delivery attempts have been unsuccessful; +- d) CANCELLED if the message has already been cancelled. + +This reply should also contain, where relevant, the following details: + +- called address; +- time of message deposit; +- number of delivery attempts made; +- latest reason for non-delivery (e.g. **NC**, **OCC**, etc.); +- time of last delivery attempt (optional); +- time of next delivery attempt (optional); +- terminal identification (e.g. answerback) of the addressed terminal. + +The format of this information is a national matter. + +### 4.11 Message cancellation procedure + +4.11.1 The calling telex subscriber should request message cancellation by inputting the following sequence: + +CAN + or +CANCEL + + +where CANCEL or CAN, is the service request identifier and is the message reference assigned by the IWF at message deposit. + +4.11.2 If a valid request has been received, the SEF should respond within three seconds with one of the following replies: + +- a) CANCELLED to indicate successful cancellation; +- b) UNABLE TO CANCEL if the message is contemporaneously in the process of being delivered; +- c) DELIVERED if the message has already been successfully delivered. + +4.11.3 It should be noted that it is only possible to cancel a message if it has not been delivered, or is not in the process of being delivered. + +### 4.12 *Status enquiry or cancel in respect of several messages* + +4.12.1 The procedures to be followed shall be in accordance with §§ 4.10 and 4.11 in respect of each message. + +### 4.13 *Provision of journal information* + +4.13.1 Having established a connection to the SEF, a calling telex subscriber may input any one of the following: + +JOURNAL + + +JOU + + +LOG + + +ENQUIRY + + +ENQ + + +In each case, the SEF should provide full information, in accordance with §§ 4.10 and 4.11, on all messages proper to the calling subscriber received within the previous 72 hours. Such information should be provided on a single line (69 spacing characters) per-message, per-address commencing with the latest message received. A pause of three seconds should be inserted in the text stream after every five lines of status information to facilitate clearing of the connection by the originating telex subscriber. + +## ANNEX A + +(to Recommendation F.89) + +### **Alphabetical list of abbreviations used in this Recommendation** + +| | | +|-----|-----------------------------------------| +| FMT | Format error | +| IMA | Input message acknowledgement | +| IPM | Interpersonal messaging | +| ITD | Input transaction accepted for delivery | +| IWF | Interworking function | +| SEF | Status enquiry function | +| SFU | Store and forward unit | \ No newline at end of file diff --git a/marked/F/T-REC-F.901-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.901-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..076e6d9e48a2acc8f83e26819e52a4f9cb1a89c2 --- /dev/null +++ b/marked/F/T-REC-F.901-199303-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:5f3863599ce0919adf60dccc2841d6db67653897fb55ed8f39e59633c0825c20 +size 8273 diff --git a/marked/F/T-REC-F.901-199303-I_PDF-E/c973a12ab7ab173217244b189dc52577_img.jpg b/marked/F/T-REC-F.901-199303-I_PDF-E/c973a12ab7ab173217244b189dc52577_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..e69d23d2a61a33e877073c7e2ebc50a3e8a82e68 --- /dev/null +++ b/marked/F/T-REC-F.901-199303-I_PDF-E/c973a12ab7ab173217244b189dc52577_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:7f48f3ea8772ea05ed650e740d0e6c4c1ed225fc507053ef2bf9c1998c680184 +size 3891 diff --git a/marked/F/T-REC-F.902-199502-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/F/T-REC-F.902-199502-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..bb91db91fb24cacf9135b70f6b9c8cc1b19350e2 --- /dev/null +++ b/marked/F/T-REC-F.902-199502-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:d9b60eca3bb8a9408f91cab114d9faf702a2d3ab136c3bfee43f65e41f3cf4dd +size 8252 diff --git a/marked/F/T-REC-F.902-199502-I_PDF-E/raw.md b/marked/F/T-REC-F.902-199502-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..ae584964de7fef62615448729b7717332478a3ca --- /dev/null +++ b/marked/F/T-REC-F.902-199502-I_PDF-E/raw.md @@ -0,0 +1,230 @@ + + +![ITU logo: A globe with a lightning bolt and the letters ITU.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: A globe with a lightning bolt and the letters ITU. + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**F.902** + +(02/95) + +**OPERATIONS AND QUALITY OF SERVICE +HUMAN FACTORS** + +--- + +**INTERACTIVE SERVICES +DESIGN GUIDELINES** + +**ITU-T Recommendation F.902** + +(Previously "CCITT Recommendation") + +--- + +# FOREWORD + +The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). + +ITU-T Recommendation F.902 was prepared by ITU-T Study Group 1 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 21st February 1995. + +# --- NOTE + +In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# CONTENTS + +| | Page | +|-----------------------------------|-------------| +| 1 Summary ..... | 1 | +| 2 Scope ..... | 1 | +| 3 References ..... | 1 | +| 4 Definitions ..... | 1 | +| 5 Abbreviations ..... | 3 | +| 6 Guidelines ..... | 3 | +| 6.1 Procedures ..... | 3 | +| 6.2 Opening message ..... | 4 | +| 6.3 Prompts ..... | 4 | +| 6.4 Error handling ..... | 4 | +| 6.5 Feedback ..... | 4 | +| 6.6 Preparation of messages ..... | 5 | +| 6.7 Usability testing ..... | 5 | +| 8 Bibliography ..... | 5 | + +# **SUMMARY** + +This Recommendation provides guidance for the design of basic procedures for the use of interactive telecommunications services using DTMF input and voice response. These services are accessible from any DTMF telephone, or from pulse-dialling telephones with the use of an adjunct DTMF dialling device. + +# INTERACTIVE SERVICES DESIGN GUIDELINES + +(Geneva, 1994) + +# 1 Summary + +This Recommendation provides guidance for the design of basic procedures for the use of interactive telecommunication services using DTMF input and voice response. These services are accessible from any DTMF telephone, or from pulse-dialling telephones with the use of an adjunct DTMF dialling device. Consequently, the user's control of the service must be accomplished solely by the use of the 12 buttons of the DTMF dial (0-9, plus \* and #). Recorded spoken messages or tones, called "prompts", are used to provide choices, guidance and feedback to users, and to ask for input of data such as telephone numbers, account numbers, time of day, etc. Choices are usually provided in the form of spoken "menus" that indicate which response (DTMF button) is associated with each available choice. + +If these guidelines are carefully observed and good human factors design practices are followed, users should find such services easy to use, enhancing user satisfaction with them. + +# 2 Scope + +Interactive voice response equipment makes possible a variety of interactive services, in which users may control the operation of the service through the use of a DTMF telephone. These include transaction services, voice messaging, information retrieval and various supplementary services. This Recommendation is intended to provide general guidelines for the design of such services to ensure that they will be easy to use for customers and to provide some degree of consistency across services. It is intended to cover all such services in which the control by the customer is exercised through the 12 keys of a DTMF telephone set (the digits 0-9 plus \* and #), and which provide prompting messages and responses in the form of recorded or synthesized speech. It does not include similar services controlled by voice commands interpreted either by human operators or by automatic speech recognition equipment. + +# 3 References + +The following Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision: all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. + +- CCITT Recommendation E.183 (1989), *Guiding Principles for Telephone Announcements*. +- ISO/IEC JTC 1/SC 18 N 4420 Revised Text of ISO/IEC 13714, *Information Technology – Document Processing and Related Communication – User Interface to Telephone-based Services: Voice Messaging Applications*. Proposed draft International Standard, 15 November 1993. Source: ISO/IEC JTC 1/SC 18/WG 9. + +# 4 Definitions + +For the purposes of this Recommendation, the following definitions apply: + +**4.1 adaptive guidance:** User-tailored prompting, feedback or help messages that differ depending on the specific context in which they are presented. + +**4.2 code:** String of digits (0-9 plus \* and #) to be dialled to access a service. + +- 4.3 command:** A request by the user for the system to perform some function. It is invoked by entering a code (see above). +- 4.4 default dialog:** System action that occurs in the absence of specific user request for a different dialog. +- 4.5 delimiter:** Symbol (\* or #) used to logically separate parts of an entry. +- 4.6 dial-ahead:** The ability to enter DTMF input before the system has requested it. It is commonly used for rapid entry of data or a series of menu choices. In dial-ahead, a user enters a key-press or key-presses in advance of the associated prompt(s) and the output of these further prompt(s) associated with the input key-press(es) is suppressed. +- NOTE – This term may also be referred to as a key-ahead, or type-ahead. The term dial-ahead is used in this Recommendation. +- 4.7 dial-through:** The interruptions of the system output with DTMF input acted on just as if it had been entered at the end of the system output. +- NOTE – This term may also be referred to as key-through or cut-through. The term dial-through is used in this Recommendation. +- 4.8 dialling device:** DTMF device acoustically coupled to a telephone set. +- 4.9 DTMF:** Dual tone multi-frequency encoding of key-press input. The definition of the encoding employed may be found in CCITT Vol. VI, Recommendation Q.23. +- 4.10 DTMF device:** A device through which a user can generate (or, in the case of the equipment such as digital telephones, duplicate the effect of) the DTMF tones associated with the keys 0-9, \* and #. This device is typically a DTMF-telephone but may also be a tone generator, a digital telephone used to invoke DTMF signals from a telephone switch, or a digital telephone. +- 4.11 feedback:** Information supplied by the system to indicate that the user actions have had their intended effects, or have had unintended effect. Typically, feedback consists of a new prompt or message indicating that an action has had its intended effect, but feedback also includes error indications and tones. +- 4.12 going off-hook:** Picking up the receiver or equivalent action to activate a telephone set. +- 4.13 help:** Information provided, either automatically or upon request, to inform users of their available prompted and unprompted choices, and of their current place in the system. +- 4.14 main menu:** The first menu encountered in the dialog when accessing a service. +- 4.15 menu:** The presentation to the user of a list of possible actions. A menu typically consists of a set of prompts each describing an available function and the user action necessary to invoke that function. +- 4.16 people with special needs:** Categories of users (e.g. elderly, children, disabled, travellers) who have special requirements in order to access a telephone terminal. +- 4.17 prompt:** Auditory system output providing instructions or guidance to the users. Prompts consist of recorded or synthesized voice and/or tones. +- 4.18 teller machine:** Automatic cash dispenser. +- 4.19 time out:** +- 1) An interval of no user input that causes the system to change state. + - 2) The state change resulting from such an interval. +- For example, a time-out during numeric input may be interpreted as end-of-string and cause the system to change from numeric input state to command state or some appropriate action state. +- 4.20 user interface:** Software and hardware components through which a user can interact with a system. +- 4.21 user-tailored menus:** Menus which are flexible so as to meet the different needs of the users. + +# 5 Abbreviations + +For the purpose of this Recommendation, the following abbreviations are used: + +| | | +|-------|---------------------------------------------------------------------------| +| CCITT | International Telephone and Telegraph Consultative Committee | +| DTMF | Dual Tone Multi-Frequency | +| IEC | International Electrotechnical Commission | +| ISO | International Organization for Standardization | +| ITU-T | International Telecommunication Union - Telecommunication Standardization | + +# 6 Guidelines + +## 6.1 Procedures + +**6.1.1** The benefit-to-cost ratio of the user access procedures should be optimized. In particular, for common and frequent procedures, entering long unstructured strings of digits should be avoided (e.g. by means of default values, logical codes, user-tailored menus, dialling devices), or such strings should at least be partitioned into logical chunks. + +**6.1.2** User procedures should be easy to learn. The design should facilitate the cognitive transfer of a user experience with similar services. The users should be able to generalize their experience from parts of the system to other parts of the system. + +**6.1.3** The design should not violate user expectations (e.g. the user procedures for using credit cards with telephones and teller machines should be similar). + +**6.1.4** The user interface should be adequate to the complexity of the service and the capabilities of the user. The user interface designer should consider the differing needs of frequent, sophisticated users and infrequent or new users. The cognitive load of the access procedures should be transferred from the user to the terminal or network by the use of suitable technology, as it becomes available. + +### Example: + +The user should be allowed to invoke the service by name (Automatic Speech Recognition) or to pick it up from a menu displayed on a screen (screenphones). + +**6.1.5** User procedures should be flexible to accommodate individual preferences. For example, if users tend to enter the means of payment both before and after going off-hook, both orders of operation should be allowed. + +**6.1.6** Similar commands should be used to access similar functions (e.g. the same delimiter should be used to indicate the end of input). + +**6.1.7** When stating options in a menu, always present the choice first, then the action to achieve it (e.g. "To send a message, press 1 now"). + +**6.1.8** The speed of the interactive dialogue should not create anxiety in the user (e.g. if the user is entering a string of digits and keying stops in mid-entry, then wait at minimum 3 and at maximum 8 seconds before timing out). + +**6.1.9** Where universal (i.e. context-independent) commands, such as accessing help or returning to the main menu, are available, they should be preceded by the \* key to preserve the remaining keys for context-dependent use. For example \*4 might be used for "help", \*7 for "return to main menu". Where they are widely available, the letters on the telephone keypad can be used to help users remember universal commands. For example, \*H could be used to access "help". + +## **6.2 Opening message** + +**6.2.1** Upon accessing a service a user should be presented with a welcome message identifying the service and making it clear the service is an automated one (e.g. "Welcome to the Universal Personal Telecommunications automated service"). + +**6.2.2** It would also be advisable to verify the user is calling from a DTMF device. + +## **6.3 Prompts** + +**6.3.1** The user should be helped through the procedures by means of voice prompts. In the case of prolonged user inactivity a message or a default dialogue should be provided. + +**6.3.2** Prompts should be kept short, in order to avoid exceeding the capacity of the users' short-term memory (e.g. only four, or at the most five, choices should be presented on a single menu; choices should be numbered sequentially in ascending order and presented in decreasing order of frequency of use or grouped by logical functions). In the case of long menus, human memory load should be minimized by allowing users to hear the menu choices repeated. This may be provided either automatically or as a result of a user request. + +**6.3.3** Universal commands (e.g. "return to main menu", "delete", etc.) that are always available should not be described in each menu, but should be described in help messages or through user documentation. + +**6.3.4** When listening to prompts, user should be allowed to dial-through and dial-ahead, i.e. to interrupt and by-pass them. This permits experienced users to speed the use of the service and minimize frustration. + +**6.3.5** The use of tones as prompts should be limited to avoid confusing users. Tones may best be used for error feedback or for indicating when to speak to record a message. + +**6.3.6** When the service is used typically by frequent users, it may need only brief prompts, but when the service is used mainly by infrequent users, it may need longer, more detailed prompting messages. + +## **6.4 Error handling** + +**6.4.1** The system should be error tolerant and, possibly, prevent errors (e.g. through the use of context-sensitive error messages, re-prompting or adaptive guidance). + +**6.4.2** User-friendly error recovery procedures should be available. For example, upon entering invalid information, a user should be given a chance to re-try. Besides, if an error was made in the middle of a long procedure, the user should be asked to repeat just the last step, not to start the entire procedure from the beginning. Uninterruptible error messages may be needed to help users who make use of dial-ahead. + +**6.4.3** The users should be allowed to cancel data entry or actions that a user cannot recover from. + +**6.4.4** In the case of important, irreversible or critical actions, the user should always be asked for confirmation (e.g. "Your calls will be sent to NNNNNN. To confirm, press 1 now; to re-enter, press 2"). + +**6.4.5** Help should be available at any time. + +**6.4.6** Help, in the form of repeated prompts, should be provided after a few seconds (depending on the context) of inactivity of the user. + +## **6.5 Feedback** + +**6.5.1** Immediate feedback should be provided after each user action to give the user the information that the system has accepted the input. This can take any of several forms, including interruption of the prompt in the case of dial-through. In general, system output indicating that user input was successful will be indicated by beginning the next prompt, menu, or announcement. + +**6.5.2** Feedback redundancy across different media (auditory, visual), if available, is helpful to the general public and may support people with special needs. + +**6.5.3** Verbal announcements should normally be used in preference to tones, as verbal announcements can convey more explicit information and are typical of traditional telephony. There may be exceptions, when the tones are very familiar and can speed use of the service. + +**6.5.4** In the sequential steps of a user procedure distinctive feedback should be provided. Using the same feedback message repeatedly should be avoided, as it does not help the users to check their progress through the procedure. + +**6.5.5** If the delay between user action and system response is longer than a few seconds (the exact amount depends on the particular situation), then the user should receive a wait message. + +## **6.6 Preparation of messages** + +**6.6.1** All messages in a service should be recorded by the same speaker. Professional speakers should be used. Voices should be agreeable and assertive. + +**6.6.2** Better understanding is achieved by using straightforward, positive sentences. However, negative sentences are helpful to discourage the user from doing certain actions (e.g. "To make another call *do not hang up*, but dial ##33"). + +**6.6.3** Messages should not contain technical expressions. + +**6.6.4** The same terminology should be used throughout the service and supportive documentation. + +**6.6.5** Conversational pleasantries used in interpersonal conversation should be minimized, as they lead to dialogue inefficiency. + +**6.6.6** Messages should be provided in the language(s) preferred by the majority of users, but requirements for international visitors should also be taken into account. + +## **6.7 Usability testing** + +**6.7.1** A service should be tested for usability before being offered to the public. The testing should be conducted by selecting a sample of representative users, and asking them to access and use the service with no instructions about how to use it beyond the instructions that will be available to real users. + +**6.7.2** Usability targets should be set before testing (e.g. 95% of users should be able to complete correctly a specific feature of the service being tested within one minute after picking up the receiver). + +# **8 Bibliography** + +SCHUMACHER (R.M.) Jr.: Phone-based interfaces: research and guidelines, *Proc. 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The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). + +ITU-T Recommendation F.910 was prepared by ITU-T Study Group 1 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 21st February 1995. + +--- + +# NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# CONTENTS + +| | Page | +|----------------------------------------------------------------------------|-------------| +| 1 Background ..... | 1 | +| 2 Methodology ..... | 1 | +| 2.1 Determine the need for an international symbol, pictogram or icon..... | 1 | +| 2.2 Design one or more alternatives ..... | 1 | +| 2.3 Evaluation procedures ..... | 1 | +| 2.4 Selection criteria ..... | 5 | +| 3 General parameters of experiments..... | 6 | +| 4 Other considerations..... | 6 | + +# **SUMMARY** + +Various national, regional and international standards organizations are responsible for the design, evaluation and standardization of symbols, pictograms and icons. In order to coordinate the work of these standards organizations, and in order to optimize the designs, it is desirable to follow a well-defined methodology. This Recommendation describes a framework for a common methodology to be used by the ITU-T. To the extent that other standards organizations can work within this framework, the development of important designs should progress more rapidly. A uniform methodology will minimize duplication of effort and will maximize the relevance of collected data. + +# PROCEDURES FOR DESIGNING, EVALUATING AND SELECTING SYMBOLS, PICTOGRAMS AND ICONS + +(Geneva, 1994) + +# 1 Background + +Various national (e.g. ANSI, CIAJ, DIN), international-regional (e.g. ETSI) and international-worldwide (e.g. ITU-T, ISO) standards organizations are responsible for the design, evaluation and standardization of symbols, pictograms and icons. In order to coordinate the work of these standards organizations, and in order to optimize the designs, it is desirable to follow a well-defined methodology. This Recommendation describes a framework for a common methodology to be used by the ITU-T. To the extent that other standards organizations can work within this framework, the development of important designs should progress more rapidly. A uniform methodology will minimize duplication of effort and will maximize the relevance of collected data1). + +There are four high-level steps in the methodology for standardizing designs. First, a need must be determined. Second, designs must be created. Third, designs must be evaluated. Fourth, designs must be selected and approved. The steps of this process are shown in Figure 1. The remainder of this Recommendation describes the methodology in detail. + +# 2 Methodology + +## 2.1 Determine the need for an international symbol, pictogram or icon + +Two or more countries should express the need for standardization in order to make the proposed symbol, pictogram or icon of international concern. + +## 2.2 Design one or more alternatives + +#### 2.2.1 Actual design process + +The ITU-T will not restrict suggested designs. The only requirement for suggested designs is that each must be usable in all appropriate forms (e.g. printed, engraved, embossed, screen-displayed). + +### 2.2.2 Process for soliciting alternative designs from ITU-T Members + +Suggested designs will be published in ITU-T meeting reports and/or Special Rapporteurs' reports which will include a request for alternative designs. Liaison statements will be sent to other relevant standards organizations. A reasonable time interval will be allowed for submissions before the evaluation procedures begin. The suggested reasonable time is a minimum of two months and a maximum of the interval from one Working Party meeting to the next. + +## 2.3 Evaluation procedures + +The various stages in the evaluation procedure are intended to measure initial (*a priori*) meaning and appropriateness, ease of learning, ease of remembering, and the probability of confusion with other designs. The order of procedures should be: + +- explain, define and demonstrate functions for each design; +- evaluate contextually meaningful associations by using the matching task shown in Figure 4 and described below in 2.3.3 b); + +--- + +1) This Recommendation was developed with the help of ITU-T contributors who are also active in other standards organizations. Some procedures used by CIAJ and some used by ETSI (in its multiple index approach) have been adapted for this Recommendation. + +- c) collect subjective data; +- d) if indicated by the subjective data, eliminate bad designs and create new candidate designs and then re-start the experiment; +- e) evaluate memory for meaning by a recall test; +- f) evaluate confusibility by a recognition-matching test. + +The evaluation should be a within-subjects design such that each person provides data in stages b), c), e) and f). + +The recommended procedures can be performed in one session, or can be accomplished in a series of sessions with the participants. If a small number of designs is under consideration, immediate memory for all of the designs may be perfect or nearly perfect, whereas delayed memory may show important differences in recall and/or recognition. It is advisable, therefore, for the evaluation coordinator to do a pilot experiment to determine a delay that will reveal differences in memory for the various designs. The evaluation coordinator should specify the procedural details before data are collected by the experimenters in various countries. + +### 2.3.1 Explain, define and demonstrate the function of each design + +- a) *Evaluate pre-existing associations* – The matching task that is illustrated in Figure 4 and described in 2.3.3 b) is administered to determine the strength of pre-existing associations between a function's verbal description and a design. These data can be used to eliminate the worst designs and to identify the most confusing designs. +- b) When possible, construct a prototype device with the test designs on it. Use this prototype to familiarize the subjects with the functions of each symbol, pictogram or icon. +- c) When construction of a prototype is not practical, the functions of the symbols that will occur together should be explained in a scenario that corresponds to a scenario that would be typical when using a device. + +### 2.3.2 Collect subjective data + +- After all the to-be-rated symbols have been described (explained), present the symbols one at a time to each subject to collect the subjective opinion and rating data. + +Figure 2 shows an example page for a questionnaire that can be used to collect these subjective data. + +In Figure 2, questions i) and ii) are to help identify those proposed designs that exist or are perceived to be too similar to designs that exist, whereas, questions iii) through vii) ask people to judge the designs *a priori* meaning, future memorability, and graphic qualities. + +If these data indicate high levels of confusion among designs or with existing designs, it may be necessary to interrupt the evaluation to generate new designs as indicated in 2.3 d). If this situation occurs, the evaluation procedure should be re-started with a new set of participants. + +### 2.3.3 Objective data + +- a) *Recall test* + +The data from this test will measure the ability of subjects to recall the meaning of individually seen designs. These data are of particular relevance to situations where designs are experienced individually (e.g. on signs, sometimes on screens, etc.). + +The general procedure is to present a design (on-screen, projected, or on paper), then to allow time for the subject to write the meaning on an answer sheet (or, alternatively, to type the meaning if the designs are computer-presented). + +Whereas, it is desirable to promote the use of consistent verbal descriptions worldwide, it is recognized that this is difficult. Therefore, care must be taken to count as correct the various verbal expressions of meaning that are essentially the same. + +![Flowchart showing the procedure for standardizing symbol, pictograms and icon designs. The process starts with 'Determine Need', followed by 'Design' (which includes creating designs, publicizing them, soliciting alternatives, liaising with organizations, specifying evaluation, determining preference, evaluating associations, determining memory performance, and determining confusability), and finally 'Selection and Approval' (which includes checking selection criteria, publishing candidates, and final approval).](fc46871d72c65d3381d9201646d23439_img.jpg) + +``` + +graph TD + subgraph DN [Determine Need] + DN_label[Determine Need] + end + subgraph D [Design] + D_label[Design] + D1[Create symbol, pictogram or icon designs.] + D2[Publicize initial designs.] + D3[Solicit alternative designs from ITU-T members.] + D4[Liaison to interested worldwide standards organizations with designs to be tested. Solicit additional designs.] + end + subgraph E [Evaluation] + E_label[Evaluation] + D5[Specify evaluation procedures in detail. Publish for participating countries to follow.] + D6[Determine preference by collecting subjective data.] + D7[Evaluate pre-existing associations. Then explain or define each candidate design's function.] + D8[Determine memory performance by collecting data (Recall memory test).] + D9[Determine confusability potential by collecting data (Recognition matching test).] + end + subgraph SA [Selection and Approval] + SA_label[Selection and Approval] + EA1{Determine whether proposed designs meet selection criteria ?} + EA2[Publish candidates for Recommendation by ITU-T and send liaison for comment to interested worldwide standards organizations.] + EA3[Approved by ITU-T] + end + + J1{Judge need for international standardization?} -- One country only --> J1_out[Not a ITU-T concern] + J1 -- Two or more countries --> D1 + D1 --> D2 + D2 --> D3 + D3 --> D4 + D4 --> D5 + D5 --> D6 + D6 --> D7 + D7 --> D8 + D8 --> D9 + D9 --> EA1 + EA1 -- No --> D1 + EA1 -- Yes --> EA2 + EA2 --> EA3 + +``` + +Flowchart showing the procedure for standardizing symbol, pictograms and icon designs. The process starts with 'Determine Need', followed by 'Design' (which includes creating designs, publicizing them, soliciting alternatives, liaising with organizations, specifying evaluation, determining preference, evaluating associations, determining memory performance, and determining confusability), and finally 'Selection and Approval' (which includes checking selection criteria, publishing candidates, and final approval). + +T0103610-94/d01 + +FIGURE 1/F.910 +**Procedure for standardizing symbol, pictograms and icon designs** + +| Function | Description | Design | +|----------|-------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Hold | Pressing the button holds a line to interrupt communication | A pictogram showing a button with a curved arrow pointing from the top left to the top right, indicating a 'hold' or 'interrupt' function. | + +I. Have you ever seen this exact symbol (or pictogram or icon) before today? + +Yes.      No. + +If yes, where? \_\_\_\_\_ + +II. Have you ever seen a symbol that is very similar to this one? + +Yes.      No. + +If yes, where? \_\_\_\_\_ + +*Please answer each of the next five questions by selecting the value on the five-point rating scale. You may also explain your rating by writing a comment in the space provided.* + +III. Given the context in which it will be used, is the symbol's meaning easy to understand? + +![A five-point rating scale for question III. The scale is a horizontal line with five tick marks. The labels from left to right are: 'Very difficult', 'Difficult', (unlabeled center tick), 'Easy', and 'Very easy'.](f5e70cbe66e71e65b4ae4aa7816d266a_img.jpg) + +A five-point rating scale for question III. The scale is a horizontal line with five tick marks. The labels from left to right are: 'Very difficult', 'Difficult', (unlabeled center tick), 'Easy', and 'Very easy'. + +IV. Do you think that the appearance (form) of this symbol will be easy to remember? + +![A five-point rating scale for question IV. The scale is a horizontal line with five tick marks. The labels from left to right are: 'Very difficult', 'Difficult', (unlabeled center tick), 'Easy', and 'Very easy'.](635262c3456135a70f7585ae445951e7_img.jpg) + +A five-point rating scale for question IV. The scale is a horizontal line with five tick marks. The labels from left to right are: 'Very difficult', 'Difficult', (unlabeled center tick), 'Easy', and 'Very easy'. + +V. If you see this symbol in the future, do you think you will remember its meaning? + +![A five-point rating scale for question V. The scale is a horizontal line with five tick marks. The labels from left to right are: 'Very unlikely', 'Unlikely', (unlabeled center tick), 'Likely', and 'Very likely'.](fd40c60cfaff879ea9bec71d4f72a8ec_img.jpg) + +A five-point rating scale for question V. The scale is a horizontal line with five tick marks. The labels from left to right are: 'Very unlikely', 'Unlikely', (unlabeled center tick), 'Likely', and 'Very likely'. + +VI. Are you likely to confuse this symbol with others that you have seen during this session? + +![A five-point rating scale for question VI. The scale is a horizontal line with five tick marks. The labels from left to right are: 'Very likely', 'Likely', (unlabeled center tick), 'Unlikely', and 'Very unlikely'.](dba42063d2ba87f5d6f4fab4882b5d0d_img.jpg) + +A five-point rating scale for question VI. The scale is a horizontal line with five tick marks. The labels from left to right are: 'Very likely', 'Likely', (unlabeled center tick), 'Unlikely', and 'Very unlikely'. + +VII. In appearance, how attractive is this design? + +![A five-point rating scale for question VII. The scale is a horizontal line with five tick marks. The labels from left to right are: 'Very unattractive', 'Unattractive', (unlabeled center tick), 'Attractive', and 'Very attractive'.](26c8a50517bc00b6cbfe94f46fbc7c08_img.jpg) + +A five-point rating scale for question VII. The scale is a horizontal line with five tick marks. The labels from left to right are: 'Very unattractive', 'Unattractive', (unlabeled center tick), 'Attractive', and 'Very attractive'. + +Thank you very much for your cooperation. + +T0103620-94/d02 + +FIGURE 2/F.910 +Subjective data collection format + +Figure 3 shows an example format for the recall test. + +#### b) *Recognition test* + +The final stage in evaluation is a recognition-matching test that will provide data to identify confusions among the designs. The general arrangement for the test items is shown by the example in Figure 4. + +- i) The first column gives a short label or technical term that describes a possible design. +- ii) The second column provides a sentence or phrase to more fully explain the verbal label. +- iii) The third column consists of an empty box wherein the subject may write an answer. +- iv) The fourth column shows the whole set of to-be-matched designs. +- v) Standard procedures for counteracting order effects should be used. That is, for a given respondent, the order of designs should vary across trials. The order of the functional descriptions should vary across respondents. The coordinator of an experiment should advise the experimenters on the exact details of such counterbalancing or randomizing procedures. + +NOTE – The most realistic test would require subjects to interact with a prototype device that has the new symbols, pictograms or icons displayed. This type of test evaluates two things: the subject's memory for each design's meaning; the subject's comprehension of the procedures required to use the device. While it may be too expensive to perform this optional final test, it may be important in some instances. + +| Designs | Function | +|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------| +| A telephone handset icon with three curved lines above it, representing a call or dial function. | | +| A telephone handset icon with a horizontal line underneath it, representing a hang-up or end call function. | | + +Thank you for your cooperation. + +T0103630-94/d03 + +FIGURE 3/F.910 +**Recall memory test format** + +## 2.4 Selection criteria + +#### a) *Two or more design candidates per function* + +When two or more designs are evaluated for a function, selection of the best design should follow these guidelines: + +- select the most preferred design (subjective rating data); +- select the design for which recall of its function was best (recall data); +- select the least confusable design (recognition data). + +If a particular design does not meet all three criteria, it may be necessary to create new design candidates. Alternatively, the design that best approximates these three criteria may be selected for standardization. The design that is determined to be the best of two or more design candidates should also meet the minimum criteria for acceptance listed in 2.4 b). + +#### b) *One design candidate per function* + +When only one design is evaluated for a function, selection criteria are more difficult. In such situations we are not asking “which design candidate is best?”, but rather “is this particular design good enough?”. The minimum criteria for acceptance of a design are suggested to be as follows: + +- subjective ratings should be at least neutral (the mid-point on the five-point scale), and preferably should be positive; +- recall of the function (meaning) for a design should be at least 50 per cent correct when averaged across subjects; +- recognition matching should at least exceed chance. + +# 3 General parameters of experiments + +### a) There are two types of evaluation studies: + +In one type, only one design is evaluated for each function. Acceptance of a design under these conditions is based on comparison to arbitrary minimum preference and performance values. Suggested minimum criteria are given in 2.4 b). + +The second type of evaluation study includes two or more design candidates per function. In general, this is the preferred type of study. Winning designs should still meet the minimum criteria given in 2.4 b). + +- b) It may be desirable to test a whole set of designs that will be used together against an alternative whole set of designs. +- c) The minimum number of countries to provide data should be three, and these should represent as widely different cultures and/or markets as possible. A greater number of countries should participate whenever possible. +- d) Sampling characteristics should be balanced so that the samples fully represent the user populations of interest. For example, it will be generally desirable to test equal numbers of males and females, equal numbers of users from each decade of life (up to 19, 20-29, 30-39, etc.), and it may be important to sample evenly from various educational or work experience categories (e.g. clerical, technical, labourer, homemaker, etc.). For some designs it may be important to include young children, elderly adults, or the sensory impaired. +- e) The presentation techniques for explaining, learning, rating, and memory testing can vary from one experiment to the next, but care must be taken to use techniques that control extraneous variables. Acceptable techniques include paper-and-pencil, video presentation, and computer-based presentation. +- f) The number of people to be tested in each country is to be determined by the experimenters, but it is suggested that the minimum number be 20 per category. +- g) The statistical procedures and summaries are to be determined by the experimenters. + +# 4 Other considerations + +- a) If a design is generally known and used in non-telecommunication contexts, some evaluation steps may be unnecessary to adopt the design for use in telecommunications. +- b) If new designs are to be used in context with existing symbols, it is advisable to include the existing symbols in the recognition test to measure confusability. + +| Technical
term | Description | No. | +|-------------------|-----------------------------------------|-----| +| On-hook dialling | Can dial without picking up the handset | | + +| Design | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 Simple speaker icon | +| 2 Treble clef musical symbol | +| 3 Telephone handset resting on a horizontal line | +| 4 Speaker icon with three sound waves radiating right | +| 5 Telephone handset with sound waves on both sides | +| 6 Telephone handset angled with sound waves radiating from the earpiece | +| 7 Telephone handset resting above three solid squares | +| 8 Speaker icon with a horizontal double-headed arrow passing through it | +| 9 Eighth note musical symbol | +| 10 Telephone handset angled downwards | + +Please write down any other observations that you have about these symbols: + +Thank you for your cooperation. + +T0103640-94/d04 + +FIGURE 4/F.910 +**Recognition-matching test format** \ No newline at end of file diff --git a/marked/F/T-REC-F.921-201808-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg b/marked/F/T-REC-F.921-201808-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..9002ee68e2b9ebf63d27d39ba8c73bdafb0e6be6 --- /dev/null +++ b/marked/F/T-REC-F.921-201808-I_PDF-E/84a1d09fb489061482111515543b60dc_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8df701536c25ab8246d2868de3c20c8a4e25168bb52c5eb9078278ab1b5b4fd8 +size 6859 diff --git a/marked/F/T-REC-F.921-201808-I_PDF-E/raw.md b/marked/F/T-REC-F.921-201808-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..aa60143eb7eb05e79fc2ff49f04b9eb3f9354c19 --- /dev/null +++ b/marked/F/T-REC-F.921-201808-I_PDF-E/raw.md @@ -0,0 +1,570 @@ + + +International Telecommunication Union + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**F.921** + +(08/2018) + +SERIES F: NON-TELEPHONE TELECOMMUNICATION +SERVICES + +Accessibility and human factors + +--- + +**Audio-based indoor and outdoor network +navigation system for persons with vision +impairment** + +Recommendation ITU-T F.921 + +![ITU logo: A globe with a red lightning bolt and the text 'ITU International Telecommunication Union'.](84a1d09fb489061482111515543b60dc_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with a red lightning bolt striking across it. To the right of the globe, the text "ITU" is written in a bold, blue, sans-serif font, with "International Telecommunication Union" in a smaller, blue, sans-serif font below it. + +ITU logo: A globe with a red lightning bolt and the text 'ITU International Telecommunication Union'. + +# ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multdestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| MULTIMEDIA SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.921 + +# Audio-based indoor and outdoor network navigation system for persons with vision impairment + +## Summary + +Recommendation ITU-T F.921 specifies how audio-based network navigation systems can be designed to ensure that they are inclusive and meet the needs of persons with visual impairments. Recommendation ITU-T F.921 adopts a technology neutral approach by specifying the functional characteristics of the system. The aim is to give designers of audio-based network navigation systems the information they need at the initial stages of development to anticipate and overcome any restrictions and barriers that prevent users with visual impairments from making full and independent use of the built environment. Recommendation ITU-T F.921 explains how to accommodate users' experience of audio-based network navigation systems and ensure the interoperability of those systems. Recommendation ITU-T F.921 recognizes that by meeting the user needs of persons with visual impairments, audio-based network navigation systems may also benefit persons with other disabilities, age-related conditions and specific needs, as well as the general public. + +This revision provides updates based on feedback received from field use of this Recommendation, as well as other text clarifications and corrections. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|------------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.921 | 2017-03-01 | 16 | 11.1002/1000/13185 | +| 2.0 | ITU-T F.921 (V2) | 2018-08-29 | 16 | 11.1002/1000/13662 | + +## Keywords + +Accessibility, audio-based, network navigation system, persons with disabilities. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2018 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|----------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation ..... | 2 | +| 4 Abbreviations and acronyms ..... | 3 | +| 5 Conventions ..... | 3 | +| 6 Design principles ..... | 3 | +| 7 Validation principles..... | 3 | +| 8 Directions..... | 3 | +| 9 Audio instructions..... | 4 | +| 9.1 Components of an audio instruction..... | 4 | +| 9.2 Audio instructions – Classification ..... | 4 | +| 10 Specific features, landmarks and objects..... | 5 | +| 10.1 Entrances and exits ..... | 5 | +| 10.2 Pathways..... | 5 | +| 10.3 Decision points ..... | 5 | +| 10.4 Tactile walking surface indicators ..... | 5 | +| 10.5 Escalators..... | 6 | +| 10.6 Stairs ..... | 6 | +| 10.7 Lifts..... | 6 | +| 10.8 Ticket control gates and barriers ..... | 7 | +| 10.9 Platforms..... | 7 | +| 11 Railway stations..... | 8 | +| 12 Mobile app features ..... | 8 | +| Appendix I – Examples of an audio instruction..... | 9 | +| Bibliography..... | 10 | + +## Introduction + +This Recommendation specifies how audio-based network navigation systems can be designed to ensure they are inclusive and meet the needs of persons with visual impairments. This Recommendation adopts a technology neutral approach by specifying the functional characteristics of the system. + +The aim is to give designers of audio-based navigation system the information they need at the initial conception stage to anticipate and overcome any restrictions and barriers that prevent users from making full and independent use of the built environment. Whilst existing audio-based network navigation systems have utilized mobile technologies to provide users with efficient, effective and satisfying wayfinding and hardware, compatibility and interoperability standards for mobile technologies may provide a useful basis for promoting audio-based navigation, this Recommendation explains how to accommodate the users' experience of inclusive audio-based network navigation systems (IABNSSs) and ensure their interoperability. This Recommendation recognizes that, by meeting the user needs of persons with visual impairments, IABNSSs can also benefit persons with other disabilities, age-related conditions and specific needs, as well as the general public. This Recommendation can be applied to IABNSSs in a variety of built environments, including those in urban or rural settings. + +NOTE – This Recommendation on audio-based network navigation systems does not consider the specialized requirements of people who are deaf or with impaired hearing. + +# Recommendation ITU-T F.921 + +## Audio-based indoor and outdoor network navigation system for persons with vision impairment + +# 1 Scope + +This Recommendation specifies requirements for the design of inclusive audio-based network navigation systems (IABNNSs) to accommodate users with vision impairment as well as users with a wide range of characteristics and capabilities. This Recommendation aims to help design professionals to achieve an inclusive environment through IABNNSs that augment the physical environment by the provision of aural information about environments for users. This Recommendation does not consider the specialized requirements of people who are deaf or with impaired hearing. + +In addition, while this Recommendation recognizes the necessity to provide audio-based network navigation outputs in languages determined by the user, provision of specific solutions is beyond scope of this Recommendation. Implementers are encouraged to ensure that the instructions are accessible to and understood by as many users as possible and are encouraged to provide for the use of a wide range of languages. Future work aims, among other things, to address this issue, and will explore the use of meta-coding for providing a flexible user-centric translation system. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ISO 23599:2012] ISO 23599:2012, *Assistive products for blind and vision-impaired persons – Tactile walking surface indicators*. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 accessibility** [b-ITU-T F.791]: The degree to which a product, device, service or environment (virtual or real) is available to as many people as possible. + +**3.1.2 disability** [b-ITU-T F.791]: Any restriction or inability to perform a function or activity in the manner or the range considered average or accepted functionality, resulting from an impairment or reduction of ability, that can be either permanent or temporary. + +**3.1.3 impairment** [b-ITU-T F.791]: Any loss or abnormality of psychological, physiological, or anatomical structure or function. + +**3.1.4 persons with age related disabilities** [b-ITU-T F.791]: Persons when they age, often develop cognitive and physical disabilities that are caused by the aging process itself. Examples are diminished eyesight, deafness in varying degrees, reduced mobility, or cognitive abilities. + +**3.1.5 persons with specific needs** [b-ITU-T F.791]: Includes persons with disabilities (PWD), persons who are not literate, those with learning disabilities, children, indigenous people, older persons with age related disabilities, and anyone who has a temporary disability. + +**3.1.6 platform accessibility features** [b-ITU-T F.791]: Accessibility functionality provided as standard on a particular hardware/software platform. + +### **3.2 Terms defined in this Recommendation** + +This Recommendation defines the following terms: + +**3.2.1 audio alert:** Aural signal designed to precede audio instructions. + +**3.2.2 audio instruction:** Aural message to provide wayfinding instructions and directions for users of audio-based network navigation systems (IABNSSs). + +**3.2.3 cardinal coordinates:** Means of communicating general directions to a user based on points of a compass where "North" is straight ahead. + +**3.2.4 clock face directions:** Means of communicating general directions to a user by reference to the positions of the hours on an analogue clock with 12 o'clock being straight ahead. + +**3.2.5 countable delimiter:** Word or phrase that uses numbers to communicate directions, e.g., the first (corridor). + +**3.2.6 decision point:** Crossing or intersection of a pathway, e.g., a route to a railway station ticket gate for departing passengers and the gate for arriving passengers. + +**3.2.7 degree directions:** Means of communicating general directions to a user by reference to the degrees of a circle, with 0° being straight ahead. + +**3.2.8 descriptive delimiter:** Word or phrase that describes an object or an environmental feature to communicate directions, e.g., the lower (concourse). + +**3.2.9 directional delimiter:** Word or phrase that usually follows a verb and communicates direction, e.g., left. + +**3.2.10 egocentric frame of reference:** Reference frame in which the spatial layout and orientation are communicated based on the individual's current location and viewpoint. + +**3.2.11 inclusive audio-based network navigation system (IABNSS):** Technologies used to augment the physical environment by the provision of an audio version of that environment for users. + +**3.2.12 journey completed notification alert:** A sequence of short three-note rising pitch sounds of equal duration provided when the scheduled journey is complete. They are different to mobile device operating system alerts. + +**3.2.13 landmark:** Feature in the physical environment, e.g., an isolated column. + +**3.2.14 notification alert:** A sequence of short two-note sounds of equal duration provided just before audio alerts and audio instructions to notify the user of an impending audio alert or audio instruction. This is different to a mobile device operating system alert. + +**3.2.15 object:** Small feature in the physical environment, e.g., a lift control button. + +**3.2.16 orthogonal:** Means of communicating general directions to a user that is different from the 'degree' approach and uses directions based on 90° angles from a direction straight ahead. + +**3.2.17 pathway:** A route allowing passage from one point to another, examples include a corridor, ramp, tunnel, subway, escalator, stair or lift (elevator), footway or road crossing. + +**3.2.18 person with a disability:** person who has a physical or mental impairment that has a substantial and long-term adverse effect on her or his ability to carry out normal day-to-day activities. + +NOTE – [b-UNCRPD] covers the rights of people with disabilities. + +**3.2.19 platform:** A boarding facility to provide access to rail-mounted vehicles. + +**3.2.20 proportional directions:** Means of communicating general directions to a user that is different to the "clock face" or "degree" approach and uses terms like "straight", "ahead", "left" and "right". + +**3.2.21 segment:** Distinctive area in an environment, e.g., a railway station forecourt. + +**3.2.22 sequential delimiter:** Word or phrase that limits the relationship of one object to communicate directions, e.g., after (the gates). + +**3.2.23 vision impairment:** A vision loss that cannot be corrected by the use of glasses, refractive correction, medication or surgery. The vision loss may affect visual acuity, central or peripheral visual field defects, or reduced contrast sensitivity. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +IABNNS Inclusive Audio-Based Network Navigation System + +PWD Person With Disabilities + +## 5 Conventions + +The following conventions are used in this Recommendation. The word "should" indicates an essential requirement in order to conform to this Recommendation. The word "may" indicates a recommendation with which it is not essential to comply in order to conform to this Recommendation. + +## 6 Design principles + +The principles for the design and interoperability of an IABNNS should involve users in the design, development and validation process, in a real environment. Users should help to identify the location of the main points of interest, key features and routes that are safe and convenient. The route should have defined segments and landmarks and be the most accessible. The content, terminology and classification used in the audio instructions are shown in clause 9. + +## 7 Validation principles + +The principles for the validation and interoperability of an IABNNS should include the testing of the installation, configuration, usability and accessibility. + +## 8 Directions + +Directions should be provided through the use of an egocentric frame of reference that communicates general directions and alerts based on a clock face, degree, proportional or orthogonal approach, as defined in clause 3.2. The most accessible route should be used. + +NOTE – An allocentric frame of reference, which communicates general directions and alerts based on cardinal coordinates ([b-Chen, 2015]; [b-Kalia, 2010]) (as defined in clause 3.2.3), may be used. + +## **9 Audio instructions** + +Audio instructions and audio alerts should be clear, unambiguous, effective and safe ([b-Allen, 2000]; [b-Kulyukin, 2008]). The piloting or chaining of routes should allow instructions to be related to particular segments of the route. The most accessible route should be used. + +### **9.1 Components of an audio instruction** + +An audio instruction should contain the elements specified in 9.1.1 to 9.1.3. + +NOTE – Two examples of an audio instruction using the elements included in this clause are shown in Appendix I. + +#### **9.1.1 Verbs** + +Verbs are used to communicate the action required, e.g., "walk". + +#### **9.1.2 Orientation information** + +Orientation information is used to communicate users' current location in relationship to their surroundings, e.g., "you are approaching". Orientation information should make reference to features of the physical environment and the route. These include segments (3.2.21), pathways (3.2.17), decision points (3.2.6), landmark (3.2.13) and objects (3.2.15). + +#### **9.1.3 Direction information** + +Direction information is used to communicate directions to the user. Direction information should use directional delimiters (3.2.9), countable delimiters (3.2.5), sequential delimiters (3.2.22) and descriptive delimiters (3.2.8). + +### **9.2 Audio instructions – Classification** + +Audio instructions are classified [b-Gaunet, 2005] as in 9.2.1 to 9.2.8. + +#### **9.2.1 Route starting instructions** + +Define the starting point of the route, the type of environment and identify the orientation of the user, e.g., "Welcome to Central Station. You are now on the main concourse. For your train, walk forward to the ticket barriers". + +#### **9.2.2 Route ending instructions** + +Define the ending point of the route, inform users they have reached their destination and that audio instructions are ending, e.g., "You have exited Central station. You are now on the east side of Alpha High Street facing the Town Hall". + +#### **9.2.3 Progression direction instructions** + +Define the direction to the next segment, pathway, decision point, landmark or object e.g., "At the bottom of the stairs, turn left and walk forward to the ticket gates". + +#### **9.2.4 Reassurance progression direction instructions** + +Reassure users that they are following a route that is communicated by audio instructions, e.g., "Keep walking forward" and should be provided every 10 m on routes where there are no changes of direction or decision points and where the user of an IABNNS has not configured their system to receive such notifications less frequently. + +#### **9.2.5 Orientation progression direction instructions** + +Communicate a change in direction prior to reaching an environmental feature, e.g., "At the next tactile paving intersection, follow the tactile paving route to the left". + +#### **9.2.6 Alerts of the location of the next environmental feature** + +Communicate information about the location of the next environmental feature, e.g., "The down escalator is the one on the left." + +#### **9.2.7 Alert to an environmental feature** + +Communicate information about an environmental feature that is close to the user, e.g., "You are approaching the escalators"; "You are approaching the stairs". + +#### **9.2.8 Alert to current location** + +Communicate information about the spatial layout of a location and the position of the user. + +## **10 Specific features, landmarks and objects** + +This clause includes a range of decision points, landmarks and objects where particular instructions and alerts should be provided. Audio instruction directions should utilize the most accessible routes. + +### **10.1 Entrances and exits** + +The audio instruction communications from an IABNNS should: + +- utilize the most accessible entrance and exit; +- allow users to choose their entrance and exit; +- provide information about the type, size and opening configuration of doors; +- provide information about the position and type of door opening furniture and operating controls. + +### **10.2 Pathways** + +The audio instruction communications from an IABNNS should: + +- utilize the most accessible pathway; +- allow users to choose their pathway; +- provide information about the type and size of the pathway; +- inform users of any curve in the pathway; +- where appropriate, advise users to keep on the side of the pathway that is best for the direction in which they are travelling when on a route where people are moving in both directions. + +### **10.3 Decision points** + +The audio instruction communications from the IABNNS should: + +- be provided at all decision points; +- utilize the most accessible decision points; +- allow users to choose their decision points; +- provide information about the type, size and configuration of decision points. + +### **10.4 Tactile walking surface indicators** + +There are two different types of tactile walking surface indicators [ISO 23599:2012], namely warning and directional indicators. + +#### **10.4.1 Warning walking surface indicators** + +These indicators are used to warn of pedestrian hazards. + +#### **10.4.2 Directional walking surface indicators** + +These indicators are used to provide direction information. + +The audio instruction communications from an IABNNS should: + +- be provided for all walking surface indicators; +- utilize the most accessible route of walking surface indicators; +- provide information about the type, size and configuration of the walking surface indicators. + +NOTE – Some tactile walking surface indicators indicate the proximity of platforms. + +### **10.5 Escalators** + +The audio instruction communications from an IABNNS should: + +- enable the user to locate the escalator; +- describe the proximity of the escalator; +- describe the moving direction of the escalator; +- describe the numbers of escalators in any group; +- describe the moving direction of each escalator in a group; +- describe the location of the handrail; +- where appropriate, state the side of the escalator where travellers stand; +- describe the relative width/length of the escalator; +- describe the next direction of the route when leaving the escalator. + +The proximity of an escalator should be given in an audio instruction $6 \pm 1$ m from the escalator. + +### **10.6 Stairs** + +The audio instruction communications from an IABNNS should: + +- enable the user to locate the stairs; +- describe the proximity of the stairs; +- describe the direction of the stairs; +- describe the numbers of steps; +- describe the location of a landing within a flight of stairs; +- describe the location of handrails; +- where appropriate, state the side of the stairs travellers use to move up and down; +- describe the relative width/length of the stairs; +- describe the next direction of the route when leaving the stairs; +- where appropriate, announce the presence of an open riser staircase. + +NOTE – Only describe the number of steps when less than 12. + +The proximity of a staircase should be given in an audio instruction $6 \pm 1$ m from the first step. + +### **10.7 Lifts** + +The audio instruction communications from an IABNNS should: + +- enable the user to locate the lift; +- describe the proximity of the lift; +- describe the numbers of lifts; + +- describe the location of call buttons outside the lift; +- describe the size of the lift; +- describe the location of call buttons inside the lift; +- indicate which button to operate to get to different levels; +- describe the next direction of the route when leaving the lift. + +The proximity of a lift should be given in an audio instruction $6 \pm 1$ m from the lift. + +The audible announcements generated by lifts e.g., the next lift to arrive, the travel direction of the lift, the entry and exit floor, and the position of the opening doors should supplement the audio instruction communications from the IABNNS. + +### **10.8 Ticket control gates and barriers** + +The audio instruction communications from an IABNNS should: + +- enable the user to locate the gates and barriers appropriate to the direction of travel; +- describe the proximity of the gates and barriers; +- describe the numbers of gates and barriers; +- describe the size of the gates and barriers; +- describe the next direction of the route when leaving the gates and barriers. + +The proximity of gates and barriers should be given in an audio instruction $6 \pm 1$ m from the gate or barrier. + +All users, including those with guide dogs, should be directed to the widest accessible gate. + +The use of gates and barriers for arriving or departing travellers should be clearly described. + +NOTE – The terminology around ticket control gates and barriers can vary between countries. In this Recommendation, the term "gate" refers to wide, accessible gates and the term "barrier" refers to an accessible route that is controlled to permit ingress and egress. + +### **10.9 Platforms** + +The audio instruction communications from an IABNNS should: + +- enable the user to locate the platform appropriate to the direction of travel; +- enable the user to orientate themselves in relation to the direction of travel of trains; +- enable the user to orientate themselves in relation to their position on the platform; +- describe the proximity of the platform; +- describe the type of platform; +- describe the numbers of platforms; +- describe the size of the platform; +- describe the size of the gap between the platform edge and the rail-mounted vehicle; +- describe any difference between the length of the rail-mounted vehicle and the platform; +- describe the next direction of the route before leaving the platform; +- indicate whether the platform is part of a pedestrian route to/from other platforms. + +The proximity of a platform should be given in an audio instruction $6 \pm 1$ m from the platform. + +NOTE – Platforms are a hazard because of the risk of falls. + +## **11 Railway stations** + +This specific type of built environment includes a range of segments, decision points, landmarks and objects where particular instructions and alerts should be provided, see clause 9.2. Audio instruction directions should utilize the most accessible routes. The segments described in this clause are the forecourt, interchange to other forms of transport, concourse, retail areas and platforms. + +The audio instruction communications from an IABNNS that relates to segments should: + +- describe the start of a segment; +- enable the location of the segments; +- describe the location of the segments; +- describe the proximity of adjoining segments; +- describe the type of segment; +- describe the size of the segment; +- describe the next direction of the route when leaving the segment. + +## **12 Mobile app features** + +The mobile app features specific to the IABNNS for the built environment should provide instructions and alerts that are accessible, simple, clear, concise, consistent, understandable and safe. + +The audio instruction communications from an IABNNS that are delivered through a mobile app should: + +- use a notification alert before an alert or instruction; +- provide user preview; +- enable user replay; +- enable user search by dictation; +- use a journey completed notification alert. + +NOTE 1 – A single action button should be utilized for user replay. + +NOTE 2 – User replay can mask current instructions. + +## Appendix I + +### Examples of an audio instruction + +(This appendix does not form an integral part of this Recommendation.) + +This appendix gives two examples of an audio instruction using the elements included in clause 9. + +#### Audio instruction + +#### *Example 1* + +"Turn left and take the escalator down to the platforms. + +The down escalator is the one on the left." + +The instruction comprises the following elements: + +Verb (i.e., "turn"), directional delimiter (i.e., "left"), verb (i.e., "take"), environmental feature is the pathway (i.e., "the escalator"), directional delimiter (i.e., "down"), directional delimiter (i.e., "to"), environmental feature is the area/segment (i.e., "the platforms"), directional delimiter (i.e., "the down"), environmental feature is the pathway (i.e., "escalator"), state-of-being verb (i.e., "is"), directional delimiter (i.e., "the one on the left"). + +#### *Example 2* + +"At the bottom of the stairs, turn right and walk forward to the platform." + +The instruction comprises the following elements: + +Sequential delimiter (i.e., "at the bottom"), environmental feature is the pathway (i.e., "the stairs"), verb (i.e., "turn"), directional delimiter (i.e., "right"), verb (i.e., "walk"), directional delimiter (i.e., "forward"), directional delimiter (i.e., "to"), environmental feature is the segment (i.e., "the platform"). + +## Bibliography + +- [b-ITU-T F.791] Recommendation ITU-T F.791 (2018), *Accessibility terms and definitions*. +- [b-Allen, 2000] Allen, G.L. (2000). [Principles and practices for communicating route knowledge](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.456.5686&rep=rep1&type=pdf). *Applied Cognitive Psychology*, **14**, 333–359. Available [viewed 2018-10-05] at: +. +- [b-Chen, 2015] Chen, H.E., Lin, Y.Y., Chen, C.H., Wang, I.F. (2015), BlindNavi: a navigation app for the visually impaired smartphone user. In: *Proceedings of the 33rd Annual ACM Conference Extended Abstracts on Human Factors in Computing Systems*, pp. 19–24). New York, NY: ACM. +- [b-Gaunet, 2005] Gaunet, F., Briffault, X. (2005), [Exploring the functional specifications of a localized wayfinding verbal aid for blind pedestrians: Simple and structured urban areas](https://dl.acm.org/citation.cfm?id=1466580). *Human–Computer Interaction*, **20**(3), 267–314. Available [viewed 2018-09-14] at: . +- [b-Kalia, 2010] Kalia, A.A., Legge, G.E., Roy, R., Ogale, A. (2010), [Assessment of indoor route-finding technology for people with visual impairment](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3160142). *Journal of Visual Impairment and Blindness*, **104**(3), 135–147. Available [viewed 2018-10-05] at: [www.ncbi.nlm.nih.gov/pmc/articles/PMC3160142](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3160142). +- [b-Kulyukin, 2008] Kulyukin, V., Nicholson, J., Ross, D., Marston, J., Gaunet, F. (2008), [The blind leading the blind: Toward collaborative online route information management by individuals with visual impairments](https://www.aaai.org/Papers/Symposia/Spring/2008/SS-08-06/SS08-06-011.pdf). In: *AAAI Spring Symposium: Social Information Processing*, pp. 54–59. Available [viewed 2018-09-14] at: +. +- [b-UNCRPD] United Nations (2007), [Convention on the rights of persons with disabilities](https://www.un.org/development/desa/disabilities/convention-on-the-rights-of-persons-with-disabilities.html). Available [viewed 2018-10-05] from: + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general 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bolt striking across it. The letters "ITU" are prominently displayed in blue and red. To the right of the globe, the text "International Telecommunication Union" is written in a smaller, blue, sans-serif font. + +ITU logo + +# ITU-T F-SERIES RECOMMENDATIONS **NON-TELEPHONE TELECOMMUNICATION SERVICES** + +| | | +|-----------------------------------------------------------------|--------------------| +| TELEGRAPH SERVICE | | +| Operating methods for the international public telegram service | F.1–F.19 | +| The gentex network | F.20–F.29 | +| Message switching | F.30–F.39 | +| The international telemessage service | F.40–F.58 | +| The international telex service | F.59–F.89 | +| Statistics and publications on international telegraph services | F.90–F.99 | +| Scheduled and leased communication services | F.100–F.104 | +| Phototelegraph service | F.105–F.109 | +| MOBILE SERVICE | | +| Mobile services and multdestination satellite services | F.110–F.159 | +| TELEMATIC SERVICES | | +| Public facsimile service | F.160–F.199 | +| Teletex service | F.200–F.299 | +| Videotex service | F.300–F.349 | +| General provisions for telematic services | F.350–F.399 | +| MESSAGE HANDLING SERVICES | F.400–F.499 | +| DIRECTORY SERVICES | F.500–F.549 | +| DOCUMENT COMMUNICATION | | +| Document communication | F.550–F.579 | +| Programming communication interfaces | F.580–F.599 | +| DATA TRANSMISSION SERVICES | F.600–F.699 | +| MULTIMEDIA SERVICES | F.700–F.799 | +| ISDN SERVICES | F.800–F.849 | +| UNIVERSAL PERSONAL TELECOMMUNICATION | F.850–F.899 | +| ACCESSIBILITY AND HUMAN FACTORS | F.900–F.999 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T F.930 + +# Multimedia telecommunication relay services + +## Summary + +Recommendation ITU-T F.930 provides a functional description of four common types of relay services in use today: text relay, video relay, captioned telephone service relay and speech-to-speech relay. Additionally, it lays out specific functional requirements of relay services pertaining to equipment, call set-up, call experience, emergency communications and message retrieval. + +Telecommunications relay services enable persons who have hearing or speech disabilities and who otherwise would be unable to engage in voice telecommunications, to make voice telephone calls to other persons. In all forms of relay services, persons with disabilities connect to a communication assistant via a communications medium that is accessible to them. The communication assistant acts as an intermediary in the telephone call and converts between the accessible communication medium and voice, which is relayed from and to the person on the other end of the call. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T F.930 | 2018-03-29 | 16 | 11.1002/1000/13571 | + +## Keywords + +Accessibility, captioned telephony relay service, communication assistant, functional equivalency, speech-to-speech relay, telecommunications relay service, text relay, text-to-speech relay, video relay, video-to-speech relay. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2018 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +###### Page + +| | | | +|-------|---------------------------------------------------------------------------------------|----| +| 1 | Scope..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| 3.1 | Terms defined elsewhere ..... | 1 | +| 3.2 | Terms defined in this Recommendation..... | 2 | +| 4 | Abbreviations and acronyms ..... | 3 | +| 5 | Conventions ..... | 4 | +| 6 | Introduction to telecommunication relay services..... | 4 | +| 6.1 | General ..... | 4 | +| 6.2 | Functional equivalency..... | 7 | +| 6.3 | Components of relay services..... | 7 | +| 6.4 | Consideration on international interworking/interoperability for relay services ..... | 7 | +| 7 | Four major types of relay services..... | 7 | +| 7.1 | Text relay (text-to-speech relay) ..... | 7 | +| 7.2 | Video relay (video-to-speech relay) ..... | 9 | +| 7.3 | Captioned telephony relay service..... | 10 | +| 7.4 | Speech-to-speech relay ..... | 11 | +| 8 | Service requirements ..... | 12 | +| 8.1 | End user equipment ..... | 12 | +| 8.2 | Call set-up, modification and tear down procedures ..... | 12 | +| 8.3 | Communication assistant..... | 12 | +| 8.4 | Point-to-point calling..... | 13 | +| 8.5 | Speed of answer..... | 13 | +| 8.6 | Emergency call handling ..... | 13 | +| 8.7 | Message service, storage, indication and retrieval ..... | 14 | +| 8.8 | Key performance indicators ..... | 14 | +| 9 | Service confidentiality and security..... | 14 | +| | Appendix I – Use of IPTV for telephone relay service..... | 15 | +| | Appendix II – Real-time text in the United States ..... | 17 | +| | Appendix III – Procedures for training of communication assistants..... | 18 | +| III.1 | Initial training ..... | 18 | +| III.2 | Instructional methods ..... | 18 | +| III.3 | Training topics..... | 19 | +| III.4 | Alternate language training topics..... | 20 | +| III.5 | Training class..... | 20 | +| III.6 | Training transition and graduation ..... | 20 | + +###### **Page** + +| | | +|------------------------------------------------------|----| +| Appendix IV – Procedures for message retrieval ..... | 21 | +| Bibliography..... | 22 | + +# Recommendation ITU-T F.930 + +## Multimedia telecommunication relay services + +## 1 Scope + +This Recommendation introduces telecommunications relay services (simply referred to as relay services). It also defines the reference model, requirements and functionality that facilitate, via an assistive intermediary (i.e., communication assistant, sign language interpreter or lipspeaker), communications between persons who have hearing or speech disabilities with hearing/speaking users over the voice telephony service in a functionally equivalent manner. The aim of this Recommendation is to enable multiple providers, even in different countries, to interwork with one another and allow all users to enjoy the same or similar experience. + +NOTE – Technical, regulatory and financial aspects vary from country to country. The Recommendation may include the statement such that there is no extra cost for persons both with and without disabilities to ensure functional equivalency. This edition of this Recommendation provides some of these aspects as initial consideration, e.g., framework and functionality that will impact the user experience globally. These aspects including global interoperability will be covered by further editions of this Recommendation. + +It is recommended to follow the requirements and mechanisms described in this Recommendation when the relay services are supported. + +It is also emphasized that the relay service is not solely about the media conversion but also includes call handling procedures (alerting, three-way call, and communication-assistant-leg release) and other emulation of user experiences in a functionally equivalent manner. Charging, protection against fraud and confidentiality of communication assistant are also relevant. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T F.703] Recommendation ITU-T F.703 (2000), *Multimedia conversational services*. + +[ITU-T F.745] Recommendation ITU-T F.745 (2016), *Functional requirements for network-based speech-to-speech translation services*. + +[ITU-T H.625] Recommendation ITU-T H.625 (2017), *Architecture for network-based speech-to-speech translation services*. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 impairment** [b-ITU-T F.791]: Any loss or abnormality of psychological, physiological, or anatomical structure or function. + +**3.1.2 lip-reading and lip-reading interpretation** [b-ITU-T F.791]: A form of communication and interpretation used by persons who are hard of hearing or persons who are deaf who may or may not use sign language. + +**3.1.3 lip speaking or oral interpreters** [b-ITU-T F.791]: The technique of interpretation for persons who are deaf and hard of hearing, where a trained interpreter speaks silently the dialogue in the audio visual content or in any other event in real time, so that the speech is clearly discernible for persons with hearing disabilities who can lip-read the words from the interpreter's mouth without the use of sign language. + +**3.1.4 persons with disabilities (PWDs)** [b-ITU-T F.791]: The correct way to refer to a person with a disability [b-UNCRPD]. + +**3.1.5 profile settings** [b-ITU-T F.791]: This is the ability for the users to store and retrieve multiple profiles containing sets of user interface preference settings without having to reset them each time, including accessibility settings. + +**3.1.6 real time** [b-ITU-T F.791]: Data or services (e.g., broadcasting) that are transmitted with virtually no delay. + +**3.1.7 relay service** [b-ITU-T F.791]: Is a telephone service that enables a person who is deaf or hard of hearing or whose speech is not clearly understood, or who prefers to use sign language, to place and receive telephone calls in real time. + +**3.1.8 specific needs** [b-ITU-T F.791]: This replaces the use of the term 'special needs'. This term refers to a wide range of categories including women, children, youth, indigenous people, older persons with age related disabilities, persons with illiteracy, as well as persons with disabilities [b-ITU PP Res.175], [b-WTDC Res.58], [b-WTDC AP]. See also clause 6.39 [of ITU-T F.791]. + +**3.1.9 text telephone:** [b-ITU-T V.18]: A device incorporating text telephony functions. + +**3.1.10 total conversation service** [ITU-T F.703]: An audiovisual conversation service providing bidirectional symmetric real-time transfer of motion video, text and voice between users in two or more locations. + +### **3.2 Terms defined in this Recommendation** + +This Recommendation defines the following terms: + +**3.2.1 captioned telephony relay service (CTRS):** A telecommunications relay service that allows communication by individuals whose voice is understood by the other user but who cannot hear the response accurately or hear at all. In the captioned telephony relay service (CTRS), the communication assistant (CA) transcribes, in real-time, the speech of the other user word for word into text without interpretation so that it can be read on visual or tactile displays. + +NOTE – This service can be used by persons who are unable to type or do not have a keyboard on their equipment and the text can be displayed on a device that does not have a keyboard. + +**3.2.2 communication assistant (CA):** A person working in a relay service with media conversation, as a human intermediary, including sign language interpreters for video relay service. + +NOTE – In some forms of relay services, the CA does not play the role of an intermediary and is completely transparent to the non-persons with disabilities (PWD). For example, in captioned telephony relay services, the CA only provides the text transcription to the PWD, and the non-PWD is unaware of it. + +**3.2.3 disability:** An evolving concept, which refers to the interaction between persons with impairments and attitudinal and environmental barriers that hinders their full and effective participation in society on an equal basis with others. + +**3.2.4 functional equivalency:** The capability to which persons with different range of abilities (in particular persons with disabilities and persons with specific needs) are able to use a communication service or system with a level of offered functions and convenience-of-use that is similar to those offered to the wider group of users in a population. + +NOTE – These include both technical and economic considerations and that no financial discrimination is imposed on relay service users. + +**3.2.5 hearing carry-over (HCO):** A feature offered by relay services, where the audio of the speaking user is directly transmitted to the other user (who can hear either all or part of the spoken speech). + +NOTE – In some forms the communication assistant (CA) does not relay the audio into another communication medium, while in others the CA does, and the persons with disabilities (PWD) has the option of switching between listening and using the alternate communication medium. + +**3.2.6 sign language:** A natural language that, instead of relying on acoustically conveyed sound patterns, uses signs made by moving the hands combined with facial expressions and postures of the body to convey meaning It is also called signed language or simply visual signing. + +**3.2.7 speech-to-speech relay:** A telecommunications relay service that allows communication by individuals with speech disabilities with voice telephone users through the use of specially trained communication assistants (CAs) who understand the speech patterns of persons with speech disabilities and can repeat the words spoken by that person. + +NOTE – When the person with disability can type, he or she can use text-to-speech relay. + +**3.2.8 telecommunications relay service:** Synonymous with relay service as defined in [b-ITU-T F.791]. + +**3.2.9 text relay (or text-to-speech relay):** A telecommunications relay service that allows communication by individuals with speech and hearing disabilities. Text is converted by a Communication Assistant into verbal information over a voice telecommunication service. + +**3.2.10 video relay (or video-to-speech relay):** A telecommunications relay service that allows communication by individuals with speech and hearing disabilities. Visual information is converted by a communication assistant (CA) to verbal information over a voice telecommunication service. + +NOTE – Video relay allows persons with hearing or speech disabilities who use sign language to communicate with voice telephone users through video equipment. The video link allows the CA to view and interpret the party's signed conversation (or visual communication) and relay the conversation back and forth with a voice caller. + +**3.2.11 voice carry-over (VCO):** A feature offered by relay services, where the persons with disabilities (PWD) speaks directly to the other end user. The audio of the PWD is directly transmitted to the other end. In some forms of voice carry-over (VCO) the PWD has the option of switching between speaking and having the communication assistant (CA) speak. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|------------------------------------------------------| +| CA | Communication Assistant | +| CTRS | Captioned Telephony Relay Service | +| HCO | Hearing Carry-Over | +| HoH | Hard of Hearing | +| HTTP | Hypertext Transfer Protocol | +| IMS | IP Multimedia Subsystem | +| KPI | Key Performance Indicator | +| MoC | Mode of Communication | +| PSTN | Public Switched Telephone Network (fixed and mobile) | +| PWD | Persons With Disabilities | +| RTT | Real-Time Text | + +| | | +|------|---------------------------------| +| STS | Speech-to-Speech | +| TRS | Telecommunication Relay Service | +| TTY | Text Telephone | +| VCO | Voice Carry-Over | +| VoIP | Voice over IP | +| VRS | Video Relay Service | + +## 5 Conventions + +None. + +## 6 Introduction to telecommunication relay services + +This clause provides a general overview of relay services and introduces key concepts. + +### 6.1 General + +Persons with hearing disabilities (deaf or hard of hearing (HoH)) and/or speech disabilities have difficulties with the use of traditional telephone services, which highly rely on voice. + +Relay services are the telecommunication services which allow persons with hearing disabilities (deaf or HoH) and/or speech disabilities to communicate more easily with hearing and speaking users by converting a medium (e.g., voice) to another medium which can appeal to other senses of persons with disabilities. + +The user with the disability has a terminal that provides an accessible communications medium, such as video or text. A communications assistant (CA) at the relay centre converts the text or signs, generated by the persons with disabilities, to voice for the hearing person. In the reverse direction, the CA converts the voice, from the speaking person, to the accessible communications medium for the user with a disability (e.g., a person who is deaf, HoH or has a speech disability). This scenario is shown in Figure 1. Users with speaking and/or hearing disabilities are shown as persons with disabilities (PWD) on the left side of this figure. Speaking and hearing users are shown as persons with no-disabilities (non-PWD) on the right side of this figure. Information exchanged is characterized by two levels: mode of communication (MoC) and medium. Mode of communication represents the direct interaction with a person regardless of the existence of networks. Medium is a transmission type supported by networks. Usually, the CA converts or augments the MoC and uses a medium suitable for the converted MoC. Table 1 contains some examples of applicable mediums and modes of communication. + +NOTE 1 – Some relay services can be used between PWDs. + +NOTE 2 – Multiple CAs are traversed when multiple different conversions are necessary. + +![Figure 1 – Relay service communication model diagram showing the flow of communication between a Person with Disabilities (PWD), a Communication Assistant (CA), and a Person without Disabilities (non-PWD).](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +The diagram illustrates the relay service communication model. It features three main components: a **PWD** (Person with disabilities) on the left, a **CA** (Communication assistant) in the center, and a **non-PWD** (or PWD) (Person without disabilities) on the right. Arrows indicate the flow of communication between them, labeled with **MoC/medium** (Mode of communication). + +- An arrow points from **PWD** to **CA** labeled **MoC/medium A**. +- An arrow points from **CA** to **non-PWD** labeled **MoC/medium B**. +- An arrow points from **non-PWD** to **CA** labeled **MoC/medium C**. +- An arrow points from **CA** to **PWD** labeled **MoC/medium D**. + +F.930(18)\_F01 + +Figure 1 – Relay service communication model diagram showing the flow of communication between a Person with Disabilities (PWD), a Communication Assistant (CA), and a Person without Disabilities (non-PWD). + +Notes to Figure 1: + +- MoC: Mode of communication. +- Terminals and network details of relay service are not shown. + +**Figure 1 – Relay service communication model** + +**Table 1 – Non-exhaustive examples of relay services** + +| Service | Direction | PWD profile | MoC/medium | CA handling | MoC/medium | Non-PWD | +|-------------------------------------|----------------|-------------------------------------------|---------------------|-----------------------|---------------------|----------------------------| +| Text relay | PWD to non-PWD | Typing capable | Written/text | Text to speech | Speech/audio | Listening | +| | reverse | Text-reading capable | Written/text | Speech to text | Speech/audio | Speaking | +| Video-to-speech relay | PWD to non-PWD | Sign language capable (expression) | Sign language/video | SL to speech | Speech/audio | Listening | +| | reverse | Sign language capable (reading) | Sign language/video | Speech to SL | Speech/audio | Speaking | +| Captioned telephony relay service | PWD to non-PWD | Capable of speech | Speech/audio | N/A (not applicable) | Speech/audio | Listening | +| | reverse | Text-reading capable | Written/video | Speech to text | Speech/audio | Speaking | +| Speech-to-speech relay | PWD to non-PWD | Some speaking difficulties | Speech/audio | Speech to speech | Speech/audio | Listening | +| | reverse | Capable of listening to speech | Speech/audio | N/A (not applicable) | Speech/audio | Speaking | +| DeafBlind video/text relay | PWD to non-PWD | Sign language capable (expression) | Sign language/video | SL to speech | Speech/audio | Listening | +| | reverse | Text reading capable (Braille/large font) | Written/text | Speech to text | Speech/audio | Speaking | +| DeafBlind video/text to video relay | PWD to PWD | Sign language capable (expression) | Sign language/video | N/A (not applicable) | Sign language/video | Sign language (reading) | +| | reverse | Text reading capable (Braille/large font) | Written/text | Sign language to text | Sign language/video | Sign language (expressing) | + +Persons with speaking and/or hearing disabilities may have other difficulties/disabilities in expressing their thinking (e.g., difficulties with the use of sign language, unfamiliarity with information technology (IT) terminals) and/or observing external information (e.g., blind). Depending on the disabilities and their impact on the communication and its direction, different relay services are more appropriate than others for their situation. + +Many relay users are able to either speak for themselves or listen for themselves. In such situations, they might prefer to transmit their voice directly to the remote hearing party or listen directly to the remote hearing party. This system is called voice carry-over (VCO) if users speak for themselves and hearing carry-over (HCO) if users listen for themselves, as shown in Figure 2. + +![Diagram illustrating Voice carry-over (VCO) and Hearing carry-over (HCO) services. The diagram shows three main components: PWD (Person with disabilities), CA (Communication assistant), and non-PWD (Person without disabilities, e.g., hearing user). Solid blue arrows represent direct voice paths: PWD's voice (VCO) from PWD to non-PWD, and non-PWD's voice (HCO) from non-PWD to PWD. Dashed arrows represent optional paths through the CA: MoC/medium A from PWD to CA, MoC/medium D from CA to PWD, CA's voice from CA to non-PWD, and non-PWD's voice from non-PWD to CA.](042733dc5e8e7f5f30b60adba3266cde_img.jpg) + +Diagram illustrating Voice carry-over (VCO) and Hearing carry-over (HCO) services. The diagram shows three main components: PWD (Person with disabilities), CA (Communication assistant), and non-PWD (Person without disabilities, e.g., hearing user). Solid blue arrows represent direct voice paths: PWD's voice (VCO) from PWD to non-PWD, and non-PWD's voice (HCO) from non-PWD to PWD. Dashed arrows represent optional paths through the CA: MoC/medium A from PWD to CA, MoC/medium D from CA to PWD, CA's voice from CA to non-PWD, and non-PWD's voice from non-PWD to CA. + +Notes to Figure 2: + +- MoC: Mode of communication +- Dashed arrows are optional, depending on choices by the persons with disabilities to use VCO or HCO + +**Figure 2 – Voice carry-over and hearing carry-over services** + +Calls using VCO/HCO operate in a similar manner to regular relay calls, except that the user's voice is transmitted to the hearing person directly or via the relay centre, or the hearing person is transmitted to the user directly or via the relay centre. + +In the case of VCO (regardless of the use of HCO), the PWD uses their voice in the direction from themselves to the non-PWD. In the case of HCO without VCO, the communication from the PWD to non-PWD in both directions can be beneficial to both users. This condition is indicated in the dotted boxes in Figure 2. + +It should be noted that, in HCO, the terminal on the PWD side can either switch between voice and the accessible communications media (such as text or video) or can carry both simultaneously. + +It should also be noted that VCO and HCO are not mutually exclusive. For example, a relay user may elect to both speak and listen directly, and use the accessible communications medium passed through a CA as a fall-back in case the relay user experiences a communications breakdown. As a further example, simultaneous VCO and HCO can also be useful in situations where a PWD and their non-PWD children jointly communicate with another non-PWD; in this case the non-PWD can use audio as their favoured communication media while the relay service involvement makes the conversation accessible to the PWD. + +Regarding the accessible communications medium, several types of relay services cater to a specific subset of PWDs. These include text relay, video relay, captioned telephony relay services, and speech-to-speech relay and are described in clause 7. + +### 6.2 Functional equivalency + +The definition of functional equivalency is provided in clause 3.2.4. + +Functional equivalency includes performance and security aspects (e.g., user experience in terms of procedures as well as performance in the pre- and post-call phases, as well as during the actual call). + +Functional equivalency includes obligations which service providers should, in a particular jurisdiction, have to meet in order to provide communication services. Functional equivalency implies that the users of relay services would not be at a disadvantage compared to the calling options available to the mainstream (such as through incurring extra costs, being restricted to specific types of equipment, being restricted in types of calls or hours during which relay services operate, or through complicated call set-up methods). + +### 6.3 Components of relay services + +Relay services consist of network services (in a narrow sense), terminals and CAs. + +The narrow-sense network services carry the various communication media that are used in relay services, and do not change the contents of the information to be carried. Note that a variety of multimedia conversational services applicable to relay services, including total conversation services, are specified in [ITU-T F.703]. + +Regarding terminals, refer to clause 8.1. + +### 6.4 Consideration on international interworking/interoperability for relay services + +Persons without disabilities are able to use global roaming to make voice calls from anywhere to anywhere in the world, even while outside their home country. The principle of functional equivalency suggests that persons with disabilities should have equivalent means to use relay services in a similarly global manner. This topic requires further study on technical, policy, financial, and legal aspects. + +## 7 Four major types of relay services + +This clause describes four common, major types of relay services that already have been implemented in multiple countries. + +### 7.1 Text relay (text-to-speech relay) + +#### 7.1.1 PSTN-based + +The deaf, HoH, or speech-disabled user employs a text telephone connected to the public switched telephone network (PSTN), or a computer that is connected to PSTN via a modem. The CA at the relay service converts the text to voice for the hearing person and converts the voice to text for the deaf person. This scenario is shown in Figure 3. + +![Diagram of a text relay service showing communication flow between a PWD (e.g., deaf user, type capable), a CA (Communication Assistant), and a non-PWD (hearing and speaking user).](cce70c739081f63a6af83dc9483f98ce_img.jpg) + +The diagram illustrates the flow of information in a text relay service. On the left, a box labeled 'PWD (e.g., deaf user, type capable)' is connected to a central box labeled 'CA'. Two arrows point between them: a top arrow labeled 'Real-time text' pointing from the PWD to the CA, and a bottom arrow labeled 'Real-time text' pointing from the CA back to the PWD. The CA is connected to a box on the right labeled 'non-PWD (hearing and speaking user)'. Two arrows point between the CA and the non-PWD: a top arrow labeled 'CA's voice' pointing from the CA to the non-PWD, and a bottom arrow labeled 'non-PWD's voice' pointing from the non-PWD back to the CA. A small label 'F.930(18)\_F03' is located at the bottom right of the diagram. + +Diagram of a text relay service showing communication flow between a PWD (e.g., deaf user, type capable), a CA (Communication Assistant), and a non-PWD (hearing and speaking user). + +Figure 3 – Text relay service + +Typically, either user can set up a call by dialling a prefix followed by the destination number, which routes the call via the relay service. This is one-step dialling. Another way is for either user to call the relay service by dialling a dedicated phone number of the service or the centre, and then providing the remote party's phone number to the CA via text or voice. This is two-step dialling. + +In the case of VCO and HCO over PSTN text relays, the user's or hearing party's voice is transmitted over the PSTN line and bridged through the relay service. Text phones on the PSTN typically must switch between voice and text and are not able to carry both simultaneously. + +VCO/HCO calls are set up in the same way as regular PSTN text relay calls. In the VCO direction, the deaf user's terminal transmits the voice conversation to the non-PWD without sending real-time text. This voice is also bridged to the CA, whose main role is in the reverse direction to convert the hearing person's voice to text, which is displayed on the deaf person's terminal. A CA listening to VCO direction can smoothly convert speech to text in the reverse direction. + +If HCO is used without VCO (complete speech disability), the CA converts text to speech from the PWD to non-PWD. + +HCO is used mainly by HoH people who find that the text helps them to understand what is being said, but profoundly deaf users can also benefit as well. HCO is also used by persons who can hear but are unable to speak. In this case, the voice goes from the non-PWD to the PWD and the PWD types their response to the CA who speaks this to the non-PWD. + +As PSTN is phased out in favour of IP-based services, PSTN-based text relay services similarly will be supplanted with IP-based relay services. + +#### 7.1.2 IP-based + +A more recent variation of text-based relay is that the deaf, HoH, or speech-disabled user employs IP-capable hardware or software (such as a computer app, web browser, smartphone, tablet, or a standalone text communication device with display and keyboard) that is connected to the Internet in place of a PSTN connection. The connection between the user and the CA is IP-based, and both text (turn-based or real-time) and voice are transmitted over IP, (e.g., voice over IP (VoIP) services, IP multimedia subsystem (IMS)-based services, or data services). The connection between the CA and the hearing side is typically over PSTN or VoIP bridged with PSTN or IMS. Like PSTN-based relay, IP-based relay offers VCO and HCO. Unlike PSTN, voice can be transmitted simultaneously with text, and text typically can be transmitted and received simultaneously (e.g., as real-time text, see Appendix II). + +Call set-up on IP offers more options than call set-up on PSTN. A few variants are outlined below: + +*User with a disability calls hearing person:* + +- option 1: the user enters the hearing person's phone number into the terminal and initiates the call. The CA automatically receives the number from the terminal and proceeds to place the call; +- option 2: the user connects to the relay service and types or voices the hearing person's phone number. The CA listens or reads the phone number off the screen and proceeds to place the call. + +*Hearing person calls person with a disability:* + +- option 1: the hearing person uses a dial prefix followed by the deaf user's assigned relay service phone number, as in the PSTN case above; +- option 2: the hearing person directly dials the deaf user's assigned phone number, and a relay CA is automatically connected and places the call. This requires that the deaf user's phone number is registered in the ENUM database; + +- option 3: the hearing person calls the relay service through its assigned phone number, and verbally gives the CA the deaf user's contact information. The CA places the call accordingly. + +### 7.2 Video relay (video-to-speech relay) + +Video relay services (VRS) are primarily targeted at persons who are deaf or HoH and that use sign language, but in principle are not limited to sign language users; lip-reading and other forms of visual communication are also supported. The deaf or HoH user employs video calling or conferencing software, or hardware terminals which connect over IP to a relay centre. The CA at the relay centre interprets from the deaf user's sign language on the video feed to voice for the hearing person and interprets from voice to back sign language for the deaf person. This scenario is shown in Figure 4. + +![Diagram of the video relay service flow. A box on the left labeled 'PWD (e.g., deaf user, sign language capable)' has a red arrow pointing right to a central box labeled 'CA' with the text 'Sign language'. A red arrow points from the 'CA' box back to the 'PWD' box with the text 'Sign language'. A blue arrow points from the 'CA' box to a box on the right labeled 'non-PWD (hearing and speaking user)' with the text 'CA's voice'. A blue arrow points from the 'non-PWD' box back to the 'CA' box with the text 'non-PWD's voice'. A small label 'F.930(18)_F04' is at the bottom right of the diagram.](7efae06af3af43ffe5d4b956a679cf54_img.jpg) + +Diagram of the video relay service flow. A box on the left labeled 'PWD (e.g., deaf user, sign language capable)' has a red arrow pointing right to a central box labeled 'CA' with the text 'Sign language'. A red arrow points from the 'CA' box back to the 'PWD' box with the text 'Sign language'. A blue arrow points from the 'CA' box to a box on the right labeled 'non-PWD (hearing and speaking user)' with the text 'CA's voice'. A blue arrow points from the 'non-PWD' box back to the 'CA' box with the text 'non-PWD's voice'. A small label 'F.930(18)\_F04' is at the bottom right of the diagram. + +**Figure 4 – Video relay service** + +The options for call set-up are similar to those available to IP-based text relay (described in clause 7.1.2). A common scenario is as follows: + +Step 1: A deaf person using a video hardware terminal or software places a call either: + +- a) directly to a PSTN, VoIP or IMS phone number and the service routes the call to a CA; or +- b) to a relay service and is presented with a CA. + +Step 2: The CA detects the phone number from the service or using sign language requests the PSTN, VoIP or IMS phone number from the deaf person and the CA then places the call using the provided phone number. + +Step 3: The person at the provided phone number communicates with the CA. + +Step 4: The CA communicates with the deaf person using sign language (or other forms of visual communication). + +Similar to text-based relay services, video relay services support VCO and HCO, which can be supported simultaneously with the video feed. Some video relay services also offer a text-based channel, either via real-time text or turn-based (i.e., total conversation, see [ITU-T F.703]), which is used to transmit supplemental information, especially information that is hard to fingerspell in sign language. The text channel is also used by persons who are deaf and with a visual impairment, but who are unable to follow sign language video but can read text and sign for themselves. + +Where sign language is involved, video relay services may entail interpretation between two different languages, i.e., the sign language and the hearing party's spoken language. As with all forms of language interpretation, this means that the CA needs to be a trained professional interpreter who is fluent in both languages, have an understanding of the subject matter that is being discussed during the call, and exhibit awareness of the cultural differences between deaf relay users and the hearing parties. This is in marked contrast to most other forms of relay services where the CA is expected to be transparent between the person with a disability and the hearing party. + +NOTE 1 – An interpreter will have a degree of impact on the communication and interpersonal dynamics, due to the nature of their presence in the interpreted event. As such, it is now widely accepted throughout the interpreting profession that interpreters do not function solely as passive conduits relaying messages back and forth between participants. This idea is considered to be dated and current thinking and research illustrates how interpreters play a more active role in any interpreted event ([b-Wadensjö], [b-Llewellyn-Jones], [b-Napier]). Firstly, they are interpreting from one language to another, and secondly, they are facilitating the interaction and the conversational dynamics that arise between two parties. During a video interpreted interaction, the interpreter may use 'linguistic strategies' [b-Roy] throughout the interaction, as necessary, to ensure that the video interpreted exchange runs smoothly and ensure successful communication is achieved. + +NOTE 2 – Some of the guidelines on video interpretation in [b-ASLI] can be useful to video interpreters in VRS. + +The video connection must be of a sufficient quality to support sign language; some guidance on this is given in [b-ITU-T H.Sup1]. + +### 7.3 Captioned telephony relay service + +Captioned telephony relay services (CTRS) are targeted at persons who are deaf or hard of hearing and that use their own voice. In this respect, it is similar to text-based relay with VCO and HCO, but unlike text-based relay, CTRS typically does not offer the deaf or hard of hearing user any options for typing text back. CTRS consists of either a special telephone that has a text screen to display captions of what the hearing party is saying, or of software that is installed on a smartphone that displays captions of what the hearing party is saying. Often users of CTRS are older adults who have progressively lost their hearing. They frequently have residual hearing and listen to the hearing party and use the captions as a supplement to augment their understanding of words or phrases that they missed during listening (refer to Figure 5). + +Typically, a CA will not be able to transcribe more than one person speaking at the same time. Additionally, the CA may or may not be able to follow a deaf person whose speech is understood by the caller. Therefore, it is necessary for the CA to focus on one voice – that of the non-PWD. This avoids the restriction of people having to take strict turns speaking and allows a more functionally equivalent dynamic telephone conversation with each party being able to interact with the other, and even interrupt each other, as they would in any telephone conversation between non-PWDs. + +![Diagram of Captioned telephony relay service flow](41a438d7e4adc17c3a4005e7c9500091_img.jpg) + +The diagram illustrates the flow of communication in a Captioned telephony relay service. It features three main components: a PWD (e.g., hard of hearing user) on the left, a CA (Captioning Assistant) in the center, and a non-PWD (hearing and speaking user) on the right. The flow is as follows: 1) The PWD sends their voice to the non-PWD (top arrow). 2) The non-PWD sends their voice to the PWD (middle blue arrow). 3) The non-PWD also sends their voice to the CA (bottom right arrow). 4) The CA generates real-time text captions (pink box) and sends them to the PWD (bottom left arrow). A small label 'F.930(18)\_F05' is present at the bottom right of the diagram. + +Diagram of Captioned telephony relay service flow + +**Figure 5 – Captioned telephony relay service** + +Unlike text-based relays with VCO, emphasis is put on the speed at which the text (i.e., the captions) is generated – captions are expected to follow the conversation in real-time at speeds typical of spoken language. To achieve these speeds, in place of the CA typing, captioned telephony relay services have employed one of three methods: + +- 1) re-speaking: the CA listens to the speech of the hearing party, revoices it, and speech recognition technology automatically transcribes those words from the CA's voice into text, which is then transmitted directly to the CTRS user; + +- 2) computer-assisted stenography: the CA listens to the speech of the hearing party, and employing a special keyboard for faster transcription, types the speech word for word in real time. A computer dictionary translates the input of the keyboard into text, which is then transmitted directly to the CTRS user; +- 3) automatic speech recognition: It has been anticipated for many years that eventually some portion of captioning might be done automatically without the assistance of a CA using automatic speech recognition (ASR) to provide a text transcription of the voice of the non-PWD. The speech of the hearing party is automatically converted to text through a speech recognition engine, a program developed for the same language, and the text is then transmitted directly to the device of the CTRS user. For an official definition of ASR in ITU-T, see [ITU-T F.745] and [ITU-T H.625]. + +NOTE – In contrast to the other methods, either no CA is involved, or a CA may be involved in a limited role, such as for the purposes of quality assurance or as a backup if the automated speech recognition fails. + +Captioned telephony relay services can be provided over both PSTN and the Internet. In the case of PSTN, voice is transmitted over one phone line, while the captions are transmitted over a second phone line in a typical scenario. In some implementations, a single phone line can support both voice and captions. In the case of Internet-based CTRS, voice is typically transmitted over PSTN or VoIP, while captions are transmitted over an Internet connection. On mobile devices, most existing CTRS services require the user to have both a voice and data plan, and that voice and data can be used simultaneously. + +In addition to the call set-up options outlined for relay services in the previous clauses, CTRS services also offer the option of placing a direct voice call to the hearing party first and connecting the relay CA into the call at a later time, for example, at the press of a button. In such set-ups, the CA receives the hearing party's voice from the CTRS user's phone over the second phone line, or over the Internet, rather than interposing itself between the user and the hearing party as in other relay calls. Typically, in such implementations, the CA also receives only the hearing party's voice, and has no access to the PWD's voice. + +### 7.4 Speech-to-speech relay + +Speech-to-speech (STS) relay service targets persons with speech disabilities. STS relay enables a person with a speech disability (and unable to type, not allowing for text-relay) to make telephone calls using their own voice (or an assistive voice device). Like all forms of telecommunication relay service (TRS), STS uses specially trained CAs to relay the conversation back and forth between the person with the speech disability and the other party to the call. STS relay CAs are specially trained in understanding a variety of speech disorders, which enables them to repeat what the person with the speech disability says in a manner that makes that individual's words clear and understandable to the other party (refer to Figure 6). + +![Diagram of Speech-to-speech relay service flow](21ad58fee90f2be50708ff541d225507_img.jpg) + +The diagram illustrates the flow of a speech-to-speech relay service. It features three main components in rectangular boxes: 'PWD (e.g., with speech difficulties)' on the left, 'CA' in the center, and 'non-PWD (hearing and speaking user)' on the right. A red arrow labeled 'PWD's voice' points from the PWD box to the CA box. A pink arrow labeled 'CA's voice' points from the CA box to the non-PWD box. A large blue arrow labeled 'non-PWD's voice (HCO)' points from the non-PWD box back to the PWD box. A small label 'F.930(18)\_F06' is located at the bottom right of the diagram. + +Diagram of Speech-to-speech relay service flow + +Figure 6 – Speech-to-speech relay service + +A dedicated phone is not needed for STS relay. An individual uses a regular voice, VoIP or IMS phone and calls the relay centre through one of the methods outlined in the clause on PSTN text relay. The person is then connected to an STS relay assistant who will repeat the spoken words, making the spoken words clear to the other party. Persons with speech disabilities may also receive STS calls, through the same methods that are used for contacting PSTN text relay users. + +## 8 Service requirements + +The following clauses describe recommended functional requirements of relay services. + +### 8.1 End user equipment + +A variety of terminal types have been used for relay services, or are newly emerging. + +- **relay-service-specific terminals:** text telephone with keyboard and display for text relay service, dedicated videophones for video relay services, and special telephones with a text display for captioned telephone relays; +- **combination of terminals:** the relay-specific terminals above combined with an ordinary telephone for text relay service with VCO/HCO; +- **smartphones, tablets and PCs with applications:** vender-specific, as well as publicly-available applications are available. This type of terminal and application can easily support combinations of media, including new media. + +Some legacy PSTN terminals are still in use today and may need further maintenance, even as telecommunications transition to IP-based services. + +It is expected that relay services support multiple terminal types with a small variety of communication and media protocols, and/or standardized communication and media protocols. + +Detailed terminal requirements need further study. + +### 8.2 Call set-up, modification and tear down procedures + +The ultimate aim of all relay service systems is that the call set-up should be no more complicated than that experienced by a pair of non-PWD users calling each other. The relay users should be able to use normal addresses (e.g., phone numbers) without prefixes. The terminals and network should make this possible. The CA should be able to be added to the call as necessary. Other methods of setting up calls may be possible, for example, as described in clause 7.1 for text-based relays; for example, the call set-up and tear-down could be handled by the relay centre. + +If a call is made via a relay centre, care should be taken to ensure that information delivered to the destination about the source of the call (e.g., line identification, location information) relates to the caller and not to the relay service. This is especially important in the case of calls made to emergency services where automatic provision of location information and a phone number for call-backs are critical. + +The PWD may be issued with a real PSTN, IMS or VoIP phone number, which a non-PWD may call and get routed automatically via a relay service to reach the PWD. + +The phone number (and the profile) of the PWD is recommended to be registered such that any calls to the phone number should be automatically routed to the appropriate CA, which follows the pre-registered information (as the profile). The detailed mechanisms, relevant data format, and potential privacy issues need further study. + +### 8.3 Communication assistant + +Communication assistants are key to relay service provisioning. Requirements can be classified into two groups: + +- 1) those to be met for the benefit of relay service users (e.g., confidentiality of the communication between PWDs and non-PWDs); and +- 2) those for the benefit of CAs (e.g., confidentiality of the CAs). + +#### **8.3.1 Communication assistant training** + +A well-trained CA will have the skills and tools to provide the best customer experience. The education and continued development of all CAs is an investment. The reputation as a TRS provider within the deaf, HoH, deafblind, speech disabled communities, and the general public comes from CAs' commitment to providing quality service. This can be done through both quality assurance teams and region-specific training to CAs on region-specific information including the names of local organizations, cities, and other common terms specific to that region. + +Relay calls for a wide variety of customers can be challenging and CA training can tackle the challenge using an initial comprehensive training program, including classroom-based, computer-based, discovery-based, and experiential learning methods. CAs learn about relay users' cultures, the evolution of relay products, regulations, policies, procedures and – most importantly - customer conversation and satisfaction skills. This training can be developed in coordination and cooperation with the relay user communities. CA trainees complete a series of scenario-based assessments, culminating in an on-the-job final assessment before graduating from initial training and handling relay calls. + +Training should not stop after CAs have started processing calls. CAs should continue to receive regular ongoing training to improve their skills and knowledge. Ongoing training and quality assurance programs are used as incentives to encourage competition between CAs and call centres and encourage continued industry-leading quality. + +See Appendix III for examples of specific procedures that have been developed for CA training in the United States. + +### **8.4 Point-to-point calling** + +End user equipment for making relay calls, as described in clause 8.1, frequently also provides a good communication option for direct point-to-point calls between two PWDs who want to use their preferred communication media. For instance, videophones designed for video relay services also may be the most convenient option with the best video quality for two sign language users to have a direct conversation over video. To cover this use case, both terminals and relay service provider networks should be designed to support point-to-point calls. + +### **8.5 Speed of answer** + +Key performance indicators for speed of answer require further study. + +### **8.6 Emergency call handling** + +During emergency calls, time is of the essence, as is the need for accurate and clear communication. Any failure to connect to emergency centres in a timely manner, get accurate information to emergency call centres, or any miscommunications could carry a high price in the form of loss of serious harm or even death of the PWD placing the call. The key functional requirements for placing emergency calls are: + +- 1) accurate and fast routing of the relay to the appropriate emergency call centre: the call centre that the relay service connects to must be the call centre that would have been reached if a non-PWD had made the emergency call in a similar situation. Furthermore, the emergency call centre must receive the call through their normal incoming emergency call phone lines, the same way that a voice emergency call is received from a non-PWD. If CA + +availability is limited, emergency calls should be prioritized (i.e., emergency callers can jump the queue of calls waiting for the next available CA to take a call); + +- 2) accurate conveyance of all supporting information: as mentioned in clause 8.3, information on the phone line and the location as it pertains to the PWD, not to the relay centre must be delivered. To the extent that an emergency call centre has access to such information from a non-PWD caller, the same information must be conveyed about a PWD who connects to the emergency services through a relay service; +- 3) accurate communication: emergency calls place unusual stress on CAs, especially CAs working with video who may be exposed to graphic images. CAs who handle emergency calls must be trained for these situations and equipped with resources to handle the stress. Additionally, if an emergency call centre is able to accept the preferred medium and MoC of a PWD directly without relay centre involvement, PWD callers should be given the ability to connect directly to the emergency call centre and conversing with emergency call takers directly. + +To the extent that next-generation emergency calling is being deployed, terminals as described in clause 8.1 and relay call set-up procedures described in clause 8.2, should interoperate with the technical standards specified by these next-generation emergency services. See [b-NENA] and [b-EENA] for examples. + +### **8.7 Message service, storage, indication and retrieval** + +See Appendix IV for an example of how procedures for message service, storage, indication and retrieval could be implemented. + +### **8.8 Key performance indicators** + +To achieve functional equivalency, performance associated with the relay services is one of the critical subjects. Parameters to be measured and their values (e.g., the upper limit, lower limit or the acceptable range) are quite likely to differ for each of the four major services. + +Quality of sign language interpreters is also discussed in terms of key performance indicators (KPIs). KPIs for sign language interpreters are under study and will be specified in a separate Recommendation. + +## **9 Service confidentiality and security** + +To achieve functional equivalency, confidentiality and security associated with the relay services are one of the critical subjects. + +Privacy, confidentiality and security shall be maintained to achieve functional equivalency. Privacy, confidentiality and security considerations extend both to the technologies used by relay services and the human CAs. + +Relay services shall be able to provide encrypted calls if the mainstream telephone services of the country in which the relay service is located provides encrypted calls. More generally, requirements for confidentiality and call security should mirror those of the mainstream telecommunications services of the country in question. + +The detailed mechanisms for achieving privacy, confidentiality and security require further study. + +## Appendix I + +### Use of IPTV for telephone relay service + +(This appendix does not form an integral part of this Recommendation.) + +It is foreseeable, and desirable in some cases, that IPTV be used for VRS. [b-ITU-T Y.Sup5] already states that video conferencing is a possible IPTV service. The following is quoted from [b-ITU-T Y.Sup5]: + +### *Videoconference* + +A videoconference service is a service providing bidirectional symmetric real-time transfer of motion video, text and voice between end-users in two or more locations. This real-time text differs from instant messaging systems because it is the bidirectional transmission of one character at a time. This gives the end-user the impression of real-time communications, just like voice or video systems that transport streaming media over IP. The concept is aimed at providing for rich media real-time conversation for all people in various situations. This includes, but is not limited to, people that are disabled in some way, e.g., the deaf or hearing impaired, blind people, etc., but also people who find themselves in a situation where the complementing media video, real-time text and voice together fulfil the conversation needs much better than only voice. + +[ITU-T F.703] covers videophones with real-time text. Ideally, all videophones should offer this service, but in many cases only video and audio are provided. [ITU-T F.703] is useful not only for the disabled but for anyone who can benefit from the textual back-up of, for example, technical data, language translations, and verbal or signed conversations. It can be used for people who are not only deaf or disabled but people who cannot communicate in either of the two mediums, or do not have command of the spoken language used. This service is useful for documenting information within videophone calls (e.g., phone numbers and addresses) without needing a pen and paper. An example would be to get a flight booking reference when making a travel arrangement. + +It is therefore natural to study a combination of ITU-T F.703 and IPTV standards such as ITU-T H.721, ITU-T H.702 and ITU-T H.760 series to be used for VRS. The details of such a combination should be for further study. + +Figure I.1 shows an example of how IPTV can be used for VRS. There are two video channels: one for the direction from the PWD to the operator (*Ch1*), and the other for the other direction, from the operator to the PWD (*Ch2*). *Ch2* can be similar to an ordinary VOD service on IPTV. *Ch1* may need some other protocol to allow the PWD to connect to the operator as well as to transmit the video image from the PWD. + +The operation of the operator is similar to an ordinary VRS. The protocols for VRS can be used for this purpose. + +![Diagram of VRS using IPTV (Figure I.1).](e69b9188aa2c14ec6b21c83f711fef65_img.jpg) + +This diagram illustrates a Video Relay Service (VRS) using IPTV. It features two main communication channels. Channel 1 (Ch 1) consists of a Video server connected to a Camera and an Operator. Channel 2 (Ch 2) consists of an IPTV server connected to an IPTV terminal and a Camera. The IPTV terminal and the Operator are linked by a bidirectional arrow labeled "SIP-lite or text ITU-T H.323 (over HTTP)". The Operator is connected to a VoIP terminal, which in turn connects to a user (represented by a person's image) via a bidirectional arrow labeled "Voice". + +Diagram of VRS using IPTV (Figure I.1). + +F.930(18)\_FI.1 + +**Figure I.1 – An example of VRS using IPTV** + +Figure I.2 describes an example of a TRS using IPTV that can be used for a HOH person who can use voice to communicate. In this example, a microphone is used to pick up the voice of HoH and the captioned text is sent over IP to be shown overlaid on the screen of the IPTV terminal. The text can be sent using hypertext transfer protocol (HTTP), for example, since this is the common protocol used in IPTV. + +![Diagram of TRS using IPTV (Figure I.2).](09955ff8214ffb6947951fc0f60eb6ab_img.jpg) + +This diagram illustrates a Text Relay Service (TRS) using IPTV. An Audio server receives "Voice" input from a Microphone (part of an IPTV terminal) and sends it to an Operator. The Operator sends "Captioned text" to a Text server, which then displays it on the IPTV terminal. The IPTV terminal and the Operator are also connected by a bidirectional arrow labeled "Text (over HTTP)". The Operator is connected to a Phone terminal, which in turn connects to a user (represented by a person's image) via a bidirectional arrow labeled "Voice". + +Diagram of TRS using IPTV (Figure I.2). + +F.930(18)\_FI.2 + +**Figure I.2 – TRS using IPTV** + +## Appendix II + +### Real-time text in the United States + +(This appendix does not form an integral part of this Recommendation.) + +On 16 December 2016, the United States (US) Federal Communications Commission (FCC) unanimously voted 5-0 to adopt new rules in the matter of the "Transition from TTY to real-time text technology; petition for rulemaking to update the Commission's Rules for access to support the transition from TTY to real-time text technology and petition for waiver of the rules requiring support for TTY technology" ([b-FCC], [b-Gallaudet]). + +**Background:** These rules provide a roadmap for the transition from wireless text telephone (TTY) support to IP-based real-time text communications. To date, wireless carriers have been required under the pre-existing FCC rules to provide support for wireless TTY communications using the Baudot/TIA-825a standard. This support requirement has been shown to be impossible to fulfil on Wi-Fi calling, which recently has been widely deployed in the United States. As a result, in 2015 AT&T simultaneously filed a petition for a waiver from these TTY rules for Wi-Fi calling, and a petition for rulemaking on supplanting the wireless TTY requirements with support for real-time text. Other carriers followed suit after AT&T's filing for a waiver. The FCC granted these waivers in December 2015 for one year and adopted a rulemaking for the transition to real-time text for wireless communications in April 2016. + +**Scope of the new rules:** The rules adopted on 16 December 2016 give wireless carriers the option to either continue support for wireless TTYs or alternatively implement real-time text (RTT) communications. In the event that real-time text is chosen, real-time text implementations must be interoperable across wireless carriers, and also be backward compatible with TTYs [b-TIA-825A], particularly for Public Safety Answering Points for emergency calling, where TTYs currently are deployed under existing law. Real-time text implementations must also support real-time text and voice as part of the same call. To meet interoperability requirements, carriers are permitted to use the IETF RFC 4103 transport protocol in conjunction with ITU-T T.140 as a safe harbour; if they implement this protocol, they are deemed to have met the interoperability requirement irrespective of what peering carriers implement. The final FCC order also provides a list of recommendations for the functional aspects of real-time text implementations (e.g., latency, character error rate, support for call transfers, leaving messages), but do not mandate them. + +Wireline communications are currently not in scope of the new rules. Compatibility with the 7-1-1 relay service system is the topic of a Further Notice of Proposed Rulemaking, also adopted on 16 December 2016. + +As of February 2018, RTT providers in the United States support text relay calls through a RTT to TTY gateway that is invoked when 7-1-1 is called. Such gateways also are invoked when a RTT user calls a TTY user or vice versa. + +### Timeline: + +- **31 December 2017:** Tier-1 carriers make RTT available in either a downloadable app or in at least one phone; +- **31 December 2018:** Phone manufacturers include RTT functionality in all new phones; +- **31 December 2019:** Tier-1 carriers make RTT available in all new phones; +- **30 June 2020:** Smaller carriers and resellers make RTT available in either downloadable app or in at least one phone; +- **30 June 2021:** Smaller carriers and resellers make RTT available in all new phones. + +## Appendix III + +### Procedures for training of communication assistants + +(This appendix does not form an integral part of this Recommendation.) + +This appendix describes specific methods that a US relay provider has developed for CA training based on its extensive experience in providing relay services. + +### III.1 Initial training + +An initial comprehensive training program of up to 80 hours has been designed to provide CA applicants with the tools and skills necessary to facilitate TRS calls successfully. The CA software application is intuitive and contains on-screen prompts. This means CA trainees need less time to learn to navigate the system and we can spend more time on customer-focused activities such as deaf culture, translating American sign language (ASL) to English, ethics, confidentiality and customer care – as outlined in the clauses below. + +#### III.1.1 Administration and testing (5.5 hours) + +From the first day of training, we want all CAs to know what is expected of them including ethics and confidentiality. This time is spent reinforcing all relay call centre policies, as well as ensuring that each CA has mastered all objectives to process calls in accordance with contractual guidelines. + +#### III.1.2 Call processing (30.5 hours) + +CAs fully understand the operation of the call-processing terminal. This allows them to meet customer requests quickly and efficiently. Additionally, training focuses on teaching CAs to use correct procedures to process each call-type, billing methods, stress management, and how to handle emergency and hotline procedures. + +#### III.1.3 Role-play and practice (24 hours) + +In order to become more proficient in the CA role, we dedicate training time for trainees to receive both simulated and on-line call processing experience. + +#### III.1.4 Diversified culture training (20 hours) + +The diversified culture training module represents aims at ensuring that employees develop a sensitivity and understanding to relay customers. The diversified culture training was initially researched and written by a deaf college intern. A number of additional organizations and individual contributors contributed to the ongoing updates. The diversified culture training module includes information about the needs of relay users. + +### III.2 Instructional methods + +We develop all of our training programs using adult learning theories. We incorporate various instructional methods to enhance the CA's ability to learn such as: + +- lectures; +- visual graphics; +- flow charts; +- videos; +- role-play scenarios; +- simulated on-line call handling; +- observation of live-call handling. + +### **III.3 Training topics** + +#### **III.3.1 Initial training schedule** + +Initial training for TRS CAs consists of up to 80 hours of curriculum, workshops, and exercises to train. + +CAs to meet the specialized communications needs of relay users who are deaf, hard of hearing, late deafened, and those who have a speech disability effectively. + +#### **III.3.2 Speech-to-speech training** + +##### **Qualifications** + +In order to be considered for an STS CA position, CA applicants must successfully achieve the following: + +- six months of employment as a CA; +- recommendation and/or approval from supervisor or manager; +- proficiency in all areas of relay call processing including grammar, enunciation and vocabulary; +- hearing acuity test administered by an audiologist using calibrated equipment to perform a speech recognition test and pure tone test. + +STS applicants who meet these qualifications receive additional training specifically on STS. Our STS training is delivered by individuals with professional experience related to Speech Disabilities and/or consumer experts and is based on adult learning theories. + +#### **III.3.3 STS training overview** + +STS applicants who meet all qualifications for the STS training program receive eight hours of classroom training specifically on speech-to-speech services. Our STS training program has been developed based on direct experience and consultation with an STS expert obtained during the initial STS trial and conducted along with eight years of experience processing STS calls. + +The STS training outline includes specific strategies used to facilitate communication without interfering with the STS user's control over the call including retention of information at the user's request and verification of what is said to verify accuracy. + +Tools available to STS CAs and STS CA applicants include: + +- audiotapes and videotapes featuring a variety of STS users with speech disabilities (It is important to note that these STS users have voluntarily provided recordings in order to promote the ongoing training of STS CAs and represent a broad range of levels of speech disability and include augmentative devices); +- STS CA training guide, which details the history of STS, the role of the STS CA, comprehension strategies and confidentiality concerns; +- ten hours of additional live observation and mentoring by seasoned, professional STS CAs. + +#### **III.3.4 Spanish language CA training program** + +After completing initial training in English, bilingual CAs receive supplemental, specialized training to process Spanish calls. In order to be considered for an alternate language CA position, applicants must successfully achieve the following: + +- recommendation and/or approval from supervisor or manager; +- proficiency in all areas of call processing including grammar, enunciation and vocabulary; +- Berlitz language assessment. + +### **III.4 Alternate language training topics** + +The following topics are discussed during training: + +- additional foreign language training topics; +- appropriate terminology; +- pacing phrases; +- explanation phrases; +- translations conveying the concept rather than word for word; +- macros; +- cultural discussion; +- CTRS training; +- CTRS CA training has been developed by the CTRS technology provider and is consistently delivered in all of our CTRS call centres, including the TRS call centres that process CTRS calls; +- orientation. + +Orientation consists of introductions, building tour, required employment paperwork, introduction to call centre policies, confidentiality requirements, and expected standards that must be met to pass training. In addition, in our TRS centres, we have added supplemental diversified culture training specifically targeted towards people who use CTRS including seniors, veterans, and others with a hearing loss. + +### **III.5 Training class** + +Initial training consists of ten days of classroom and hands-on training. CTRS training is an interactive class combining video and hands on instruction. Each class introduces a skill and allows time to practice the skill. CTRS training uses simulators that allow the CA to listen to pre-recorded scripts and hear the voice of the hearing person in order to practice captioning. During the second week, timing tests are given each day to check CAs' transcription rate and accuracy. Improvement rate is evaluated. + +### **III.6 Training transition and graduation** + +All CAs that pass two rounds of timing tests consecutively are paired with a mentor for a week. This mentor provides one-on-one coaching for every call. If the CA meets performance expectations on live calls, the trainee graduates and is allowed to process calls independently. + +## Appendix IV + +### Procedures for message retrieval + +(This appendix does not form an integral part of this Recommendation.) + +The following is a brief outline of a US relay provider's standard process used for retrieving voice mails. These standard processes are modified based on individual relay user requests on either a per-call or per-line. + +(Customer Profile) basis. + +### Retrieving Voice Mail Procedures + +When a relay user asks to retrieve voicemail, the CA will ask the caller for the appropriate information, if not provided, e.g., + +(MAY I HAVE UR VOICE MAIL NBR AND PASS CODE PLS Q) GA + +The CA dials the requested number and reaches an answering machine, keeping the relay user informed of the call progress. + +DIALING LOCAL CALL XXX-XXX-XXXX RINGING 1... 2... 3... 4... + +Once the voicemail system answers, the CA enters the passcode using a touchtone keypad. + +If there are no new messages, the CA will relay this information and wait for additional customers instructions. + +(NO NEW MESSAGES) GA + +If there are new messages, the CA will retrieve all voicemail messages while keeping the relay user informed and prompting them for actions, as appropriate. + +(ONE MOMENT PLS) + +(SAVE Q DELETE Q REPLAY Q) GA + +(REDIALING TO GET MSGS) + +Once all voicemail messages have been successfully retrieved, the CA will inform the relay user and follow the user's instructions. + +## Bibliography + +- [b-ITU-T F.791] Recommendation ITU-T F.791 (2015), *Accessibility terms and definitions*. +- [b-ITU-T H.Sup1] ITU-T H-Series Supplement 1 (1999), *Application profile – Sign language and lip-reading real-time conversation using low bit rate video communication*. +- [b-ITU-T V.18] Recommendation ITU-T V.18 (2000), *Operational and interworking requirements for DCEs operating in the text telephone mode*. +- [b-ITU-T Y.Sup5] ITU-T Y-Series Supplement 5 (2008), *ITU-T Y.1900-series – Supplement on IPTV service use cases*. +- [b-ITU PP Res.175] ITU Plenipotentiary Conference Resolution 175 (Busan, 2014), *Telecommunication/information and communication technology accessibility for persons with disabilities and persons with specific needs*. +- [b-ASLI] Helen Ryan and Robert Skinner. *ASLI Video Interpreting Best Practices*. +<[https://www.asli.org.uk/app/uploads/2017/05/ASLI\\_Video\\_Interpreting\\_Best\\_Practice\\_VIBP-1.pdf](https://www.asli.org.uk/app/uploads/2017/05/ASLI_Video_Interpreting_Best_Practice_VIBP-1.pdf)> +- [b-EENA] European Emergency Number Association, EENA LTD v1.1 (2013), *Next Generation 112 Long Term Definition v1.1*. +<[www.eena.org/ressource/static/files/2013-03-15-eena\\_ltd\\_v1-1\\_final.pdf](http://www.eena.org/ressource/static/files/2013-03-15-eena_ltd_v1-1_final.pdf)> +- [b-FCC] United States Federal Communications Commission, *Adoption of real-time text rules, report & order, and further rulemaking*. +<> +- [b-Gallaudet] *Gallaudet University video log in American Sign Language explaining the implications of the new rules*: +<> +- [b-Llewellyn-Jones] Llewellyn-Jones, P., & Lee, R. G. (2013). *Getting to the Core of Role: Defining Interpreters' Role Space*. *International Journal of Interpreter Education*, 5(2), 54-72. +- [b-Napier] Roy, C. B., & Napier, J. (Eds.). (2015). *The sign language interpreting studies reader (Vol. 117)*. John Benjamins Publishing Company. Chicago. +- [b-NENA] National Emergency Number Association, NENA-STA-010.2-2016, NENA. *Detailed Functional and Interface Standards for the NENA i3 Solution*. +<[https://www.nena.org/?page=i3\\_stage3](https://www.nena.org/?page=i3_stage3)> +- [b-Roy] Roy, C. B. (1993), *A sociolinguistic analysis of the interpreter's role in simultaneous talk in interpreted interaction*. *Multilingua-Journal of Cross-Cultural and Interlanguage Communication*, 12(4), 341-364. Chicago. +- [b-TIA-825A] Telecommunications Industry Association (2003), *TIA-825 Revision A, A Frequency Shift Keyed Modem for Use on the Public Switched Telephone Network*. +- [b-Wadensjö] Wadensjö, C. (1993), *The double role of a dialogue interpreter*. *Perspectives: studies in Translatology*, 1(1), 105-121. + +- [b-WTDC AP] ITU World Telecommunication Development Conference (2014), *Action Plan*. +- [b-WTDC Res.58] ITU World Telecommunication Development Conference Resolution 58 (Rev Dubai 2014), *Telecommunication/information and communication technology accessibility for persons with disabilities, including persons with age-related disabilities*. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.104-199303-I_PDF-E/raw.md b/marked/T/T-REC-T.104-199303-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..91956ae41d695bcd2398fd4b0c3d712a60fb6805 --- /dev/null +++ b/marked/T/T-REC-T.104-199303-I_PDF-E/raw.md @@ -0,0 +1,588 @@ + + +![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU and a lightning bolt symbol. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# T.104 + +(03/93) + +**TELEMATIC SERVICES** + +**TERMINAL EQUIPMENTS AND PROTOCOLS +FOR TELEMATIC SERVICES** + +--- + +**PACKET MODE ACCESS FOR +SYNTAX-BASED VIDEOTEX VIA PSTN** + +**ITU-T Recommendation T.104** + +(Previously "CCITT Recommendation") + +--- + +# FOREWORD + +The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecommunication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +ITU-T Recommendation T.104 was prepared by the ITU-T Study Group VIII (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). + +--- + +# NOTES + +1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector. + +In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms “CCITT, CCIR or IFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. + +2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# CONTENTS + +| | | Page | +|----|------------------------------------------------------------------|-------------| +| 1 | Scope ..... | 1 | +| 2 | Normative references ..... | 1 | +| 3 | Definitions and abbreviations ..... | 2 | +| 4 | Overview ..... | 2 | +| 5 | Configurations ..... | 2 | +| 6 | General Model ..... | 2 | +| 7 | Service Definition ..... | 3 | +| | 7.1 Introduction ..... | 3 | +| | 7.2 Kernel services ..... | 3 | +| | 7.3 Optional services ..... | 4 | +| 8 | Protocol ..... | 4 | +| 9 | Coding ..... | 4 | +| 10 | Use of Recommendation X.3 Parameters ..... | 5 | +| 11 | Bearer Independent Service (BIS) for Syntax-based Videotex ..... | 5 | +| 12 | Lower Layers ..... | 5 | +| | 12.1 Layer 3 protocols ..... | 5 | +| | 12.2 Layer 2 ..... | 5 | +| | 12.3 Layer 1 protocol ..... | 5 | +| 13 | Asynchronous interface ..... | 6 | +| | Annexe A – Examples of configurations ..... | 6 | +| | A.1 Symbols ..... | 6 | +| | A.2 Connection to a VH ..... | 6 | +| | A.3 Access to a VS via a VAP ..... | 7 | +| | A.4 Host to terminal call establishment ..... | 10 | +| | A.5 Terminal to terminal communication ..... | 10 | +| | Annexe B – Usage of supplementary services ..... | 11 | +| | Annexe C – Terminal Function basic state ..... | 11 | +| | Annexe D – The SBV-Escape service ..... | 11 | +| | Annexe E – Extended data forwarding signals ..... | 11 | +| | Annexe F – Operating sequences for V.29 short turn around ..... | 11 | +| | F.1 Turn-ON sequence at 9600/7200 bits per second ..... | 11 | +| | F.2 Turn-ON sequence at 4800/2400 bit/s ..... | 12 | +| | F.3 Turn-OFF sequence ..... | 13 | +| | F.4 Circuit 109 ..... | 13 | +| | F.5 Circuit 106 ..... | 13 | + + + +# **PACKET MODE ACCESS FOR SYNTAX-BASED VIDEOTEX VIA PSTN** + +*(Helsinki, 1993)* + +# **1 Scope** + +This Recommendation aims to meet the requirements of network operators and equipment manufacturers who are designing equipment to operate with an increase speed on Videotex Services over the public switched telephone network (PSTN). + +This Recommendation has a close relationship to Annexes B/T.101, C/T.101, D/T.101, E/T.101 and F/T.101 [2] describing the Videotex data syntaxes. + +This Recommendation specifies how to use the end-to-end protocols defined by Recommendation T.105 [3] in case of “Packet mode access for Syntax-based Videotex via PSTN”. + +It + +- identifies the parts of Recommendation T.105 [3] which apply; +- defines the protocol pillar ; +- precises the difference of semantic of some parameters +- precises the lower layer elements which are applicable. + +It is applicable to devices supporting “Packet mode access for Syntax-based Videotex via PSTN” to be attached at the DTE side of a modem. In this context, a device is either a Videotex Terminal a Videotex Service Center, a Videotex Access point or a Videotex Host and a modem is a device providing an interface according to one of the V Series Recommendations contained in the list given in clause 2. + +This Recommendation applies only for modems operating in “Synchronous interface” in both directions. + +For Videotex Services using modems operating in “Asynchronous interface”, the protocols to be used are those already defined by national Videotex Services. + +The following principles apply for the use of Recommendation T.105 [3] in case of “Packet mode access for Syntax-based Videotex via PSTN”: + +- the term “S/T reference point” shall be read “Modem interface” +- the PSTN network shall be used instead of the ISDN network; +- in case of “Packet mode access for Syntax-based Videotex via PSTN” there is no D-channel and/or B-channel ; the communication and/or signalling is done via the protocol pillar described in clause 6; +- all parts of Recommendation T.105 [3] related to the use of “ISDN Supplementary Services” do not apply for “Packet mode access for Syntax-based Videotex via PSTN” +- a communication channel is equivalent to a virtual circuit (VC). + +# **2 Normative references** + +- [1] CCITT Recommendation T.90 (1991), *Characteristics and protocols for terminals for telematic services in ISDN*. +- [2] CCITT Recommendation T.101, *International Interworking for Videotex Services*. +- [3] CCITT Recommendation T.105, *Syntax-based Videotex Application Layer protocol*. +- [4] CCITT Recommendation V.22 bis (1988), *2400 bit/s duplex modem using the frequency division technique standardized for use on the general switched telephone network and on point to point 2 wire leased telephone type circuits*. + +- [5] CCITT Recommendation V.26 bis (1988), *2400/1200 bit/s modem standardized for use in the general switched telephone network.* +- [6] CCITT Recommendation V.26 ter (1988), *2400 bit/s duplex modem using the echo cancellation technique standardized for use on the general switched telephone network and on point to point 2 wire leased telephone type circuits.* +- [7] CCITT Recommendation V.27 ter (1988), *4800/2400 bit/s modem standardized for use in the general switched telephone network.* +- [8] CCITT Recommendation V.29 (1988), *9600 bit/s modem standardized for use on point to point 4 wire leased telephone type circuits.* +- [9] CCITT Recommendation V.32 (1988), *A family of 2-wire, duplex modems operating at data signalling rates of up to 9600 bit/s for use on the general switched telephone network and on leased telephone type circuits.* +- [10] CCITT Recommendation V.17 (1990), *Recommendation for a 2-wire modem for facsimile applications with rates up to 14 400 bit/s.* +- [11] CCITT Recommendation V.42 (1988), *Error correction procedures for DCE using asynchronous/synchronous converter.* +- [12] CCITT Recommendation X.3, *Packet assembly disassembly facility (PAD) in a public data network.* +- [13] CCITT Recommendation X.32, (1988), *Interface between data terminal equipment (DTE) and data-circuit terminating equipment (DCE) for terminals operating in the packet mode and accessing a packet switched public data network through a public switched telephone network or an integrated service digital network or a circuit switched public data network.* +- [14] CCITT Recommendation X.75, *Packet-switched signalling system between public networks providing data transmission services.* +- [15] ISO 8208 standard (1990), *Information processing systems – Data communications – X.25 Packet Level Protocol for Data Terminal Equipment.* + +NOTE – The above list of modem Recommendations (V Series) might be extended if other types of modem will be standardized. + +# **3 Definitions and abbreviations** + +The definitions and abbreviations of Recommendation T.105 [3] apply. Those related to ISDN are not used in this Recommendation. + +# **4 Overview** + +Clause 4/T.105 [3] applies except 4.5/T.105 [3]. + +# **5 Configurations** + +Clause 5/T.105 [3] applies but examples of configurations are given in Annex A of this Recommendation. + +# **6 General Model** + +Clause 6/T.105 [3] applies with the following exceptions: + +- the Access Network shall be the PSTN (see Figure 1) ; +- there are no “Channel-Management” and “Coordination Function” for “Packet mode access for Syntax-based Videotex via PSTN”; + +![Diagram of the Access Network scenario showing Terminal Function and Access Function stacks connected to a central PSTN block.](fc46871d72c65d3381d9201646d23439_img.jpg) + +The diagram illustrates the Access Network scenario. It features two protocol stacks on either side of a central 'Access Network' block. The left stack is labeled 'Terminal Function' and the right stack is labeled 'Access Function'. Both stacks consist of four layers: Layer 7 (top), Layer 3, Layer 2, and Layer 1 (bottom). The central 'Access Network' block is labeled 'PSTN'. Lines connect the Layer 1 of the Terminal Function stack to the PSTN block, and the Layer 1 of the Access Function stack to the PSTN block. The text 'T0808510-91/d01' is located at the bottom right of the diagram. + +Diagram of the Access Network scenario showing Terminal Function and Access Function stacks connected to a central PSTN block. + +FIGURE 1/T.104 +Access Network scenario + +- the protocol pillar is defined as follows + +| | | | +|-------|--------------------------------|-------------| +| 3 | ISO 8208 [15] | | +| 2 | X.75 [14], X.32 [13]
(LAPX) | X.75 [14] | +| 1 | V-Series Modem Recommendations | | +| Layer | Half Duplex | Full Duplex | + +FIGURE 2/T.104 +Protocol Pillar + +NOTE – Layers 4 and 5 are not used by “Packet mode access for Syntax-based Videotex via PSTN” Moreover, Note 2 of 6.3/T.105 [3], does not apply. + +# 7 Service Definition + +## 7.1 Introduction + +Subclause 7.1/T.105 [3] applies. + +## 7.2 Kernel services + +Subclause 7.2/T.105 [3] applies with the following exceptions: + +### 7.2.1 SBV\_Establish + +The following parameters are not used by “Packet mode access for Syntax-based Videotex via PSTN”: + +- OB\_Called\_Address; +- OB\_Called\_Subaddress; +- OB\_Application\_Address; +- OB\_Application\_Selection; +- OB\_Application\_Data; +- OB\_User\_Data; + +### 7.2.2 SBV\_Release + +The following parameter is not used by “Packet mode access for Syntax-based Videotex via PSTN”: + +- OB\_Cause. + +## 7.3 Optional services + +Subclause 7.3/T.105 [3] applies with the following exceptions: + +### 7.3.1 SBV\_Channel\_Open + +The following parameters are not used by “Packet mode access for Syntax-based Videotex via PSTN”: + +- Req\_OB\_Called\_Address ; +- Req\_OB\_Called\_Subaddress +- OB\_Application\_Address; +- OB\_Application\_Selection; +- OB\_Application\_Data; +- Req\_OB\_User\_Data +- Ind\_OB\_Cause. + +### 7.3.2 SBV\_Channel\_Error + +The following parameter is not used by “Packet mode access for Syntax-based Videotex via PSTN”: + +- Ind\_OB\_Cause. + +# 8 Protocol + +Clause 8/T.105 [3] applies. + +# 9 Coding + +Clause 9/T.105 [3] applies. + +However, the following parameters shall not be used (see Table 40/T.105 [3]): + +- Ind\_OB\_Cause; +- OB\_Application\_Address; +- OB\_Application\_Data; +- OB\_Application\_Selection; +- OB\_User\_Data; +- Req\_OB\_Called\_Address; +- Req\_OB\_Called\_Subaddress; +- Req\_OB\_User\_Data. + +# **10 Use of Recommendation X.3 [12] Parameters** + +Clause 10/T.105 [3] applies with the following exception: + +In Table 43/T.105 [3], the parameter 11 may take one among the following values: + +12 (2400 bit/s), 13 (4800 bit/s), 14 (9600 bit/s) and 15 (19200 bit/s) (see Recommendation X.3 [12] for details). + +In that case, the Note 6 of Table 43/T.105 [3] does not apply. + +# **11 Bearer Independent Service (BIS) for Syntax-based Videotex** + +Clause 11/T.105 [3] applies with respect to the In-band procedures. + +# **12 Lower Layers** + +This clause describes the lower layers (layer 1 to 3) for a “Packet mode access for Syntax-based Videotex via PSTN” terminal. The description makes the difference between modems operating in half-duplex mode and those operating in full-duplex. + +This clause does not apply for modems operating in “Asynchronous” interface. The protocols to be used for modems operating in “Asynchronous” interface are described in clause 13. + +## **12.1 Layer 3 protocols** + +### **12.1.1 Full-duplex mode** + +The layer 3 protocol to be used is described in Recommendation T.90 [1] + +### **12.1.2 Half-duplex mode** + +The layer 3 protocol to be used is described in Recommendation T.90 [1] with the following supplementary rules: + +- the default packet window size is 3. + +NOTE – This default window size has been chosen because it allows a more efficient throughput in half-duplex. + +## **12.2 Layer 2** + +### **12.2.1 Full-duplex mode** + +The layer 2 protocol to be used is defined in Recommendation T.90 [1]. + +Alternatively, the layer 2 may also be embedded within the modem as described in Recommendation V.42 [11]. + +NOTE – The exact procedure for such a configuration needs further study. + +### **12.2.2 Half-duplex mode** + +The layer 2 protocol to be used is described in Recommendation T.90 [1]. The specific procedure (LAPX) to be applied in case of half-duplex mode is described in 5.6/X.32 [13]. + +## **12.3 Layer 1 protocol** + +The layer 1 protocol to be used is the one described in the CCITT Recommendation, listed in clause 2 (V Series of Recommendations), related to the type of modem used. For V.29 [8] modems, Annex F describes the operating sequences for V.29 short turn around. + +# 13 Asynchronous interface + +Videotex Services operating over the PSTN may wish to use different types of modems in “Asynchronous” interface, allowing an increase speed of communication, without modifying the lower layers protocols (error correction procedure by example) already used . + +For modems operating in the “Asynchronous” interface, the lower layers protocols to be used are those already defined by the different Videotex Services. + +# Annex A + +## Examples of configurations + +(This annex forms an integral part of this Recommendation) + +## A.1 Symbols + +See Figure A.1. + +![Figure A.1/T.104: Symbols for Videotex Terminal, Videotex Access Point, and Host.](54fabc351eda5228d2fa28cd9ba07971_img.jpg) + +The diagram shows three symbols used in the configuration examples: + +- Videotex Terminal (VT):** Represented by a triangle pointing to the right, with the label 'VT' inside. Below it is the text 'VideotexTerminal'. +- Videotex Access Point (VAP):** Represented by a triangle pointing to the left, with the label 'VAP' inside. Below it is the text 'Videotex Access Point'. +- Host (VH):** Represented by a rectangle with the label 'VH' inside. Below it is the text 'Host'. + +Each symbol has a horizontal line extending from its right side. The reference code 'T0808530-91/d02' is located below the Host symbol. + +Figure A.1/T.104: Symbols for Videotex Terminal, Videotex Access Point, and Host. + +FIGURE A.1/T.104 +Symbols + +## A.2 Connection to a VH + +The Videotex Terminal is connected directly to a Videotex Host via the PSTN. At the protocol level, one connection is established between the terminal and host. See Figures A.2 and A.3. + +![Figure A.2/T.104: Connection to a VH via PSTN.](fc69ceb1dee1da7e33bd6c38fc4ceab9_img.jpg) + +The diagram illustrates the connection between a Videotex Terminal (VT) and a Videotex Host (VH) via the Public Switched Telephone Network (PSTN). The VT symbol (a triangle pointing right) is connected to a dashed oval labeled 'PSTN', which is in turn connected to the VH symbol (a rectangle). Below the diagram is the reference code 'T0808540-91/d03'. + +Figure A.2/T.104: Connection to a VH via PSTN. + +FIGURE A.2/T.104 +Connection to a VH + +![Diagram of the protocol stack for VT-VH connection. It shows two vertical stacks of protocol layers. The left stack is labeled 'VT' and the right stack is labeled 'VH'. Each stack has five layers: Layer 7 (Application), Layer 3 (Network), Layer 2 (Data Link), Layer 1 (Physical), and an unlabeled layer between 3 and 4. The top layer (7) is connected to a 'Terminal Application' box, and the bottom layer (1) is connected to a 'Service Application' box. Horizontal lines connect corresponding layers between VT and VH: Layer 7 to Layer 7, Layer 3 to Layer 3, Layer 2 to Layer 2, and Layer 1 to Layer 1. The diagram is identified by the code T0808550-91/d04.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +Diagram of the protocol stack for VT-VH connection. It shows two vertical stacks of protocol layers. The left stack is labeled 'VT' and the right stack is labeled 'VH'. Each stack has five layers: Layer 7 (Application), Layer 3 (Network), Layer 2 (Data Link), Layer 1 (Physical), and an unlabeled layer between 3 and 4. The top layer (7) is connected to a 'Terminal Application' box, and the bottom layer (1) is connected to a 'Service Application' box. Horizontal lines connect corresponding layers between VT and VH: Layer 7 to Layer 7, Layer 3 to Layer 3, Layer 2 to Layer 2, and Layer 1 to Layer 1. The diagram is identified by the code T0808550-91/d04. + +FIGURE A.3/T.104 +**Protocol stack for VT-VH connection** + +## A.3 Access to a VS via a VAP + +The terminal accesses a Videotex Service via a Videotex Access Point. The Host Access Network will be a PDN (generally a PSPDN). See Figure A.4. + +![Diagram of the connection via a VAP. It shows a sequence of components connected in a line: a triangle labeled 'VT' (Terminal) connected to an oval labeled 'PSTN' (Public Switched Telephone Network), which is connected to a triangle labeled 'VAP' (Videotex Access Point), which is connected to an oval labeled 'HAN' (Host Access Network), which is finally connected to a rectangle labeled 'VH' (Videotex Host). The diagram is identified by the code T0808560-91/d05.](d26959f4514c26ca19c3d6f00da85956_img.jpg) + +Diagram of the connection via a VAP. It shows a sequence of components connected in a line: a triangle labeled 'VT' (Terminal) connected to an oval labeled 'PSTN' (Public Switched Telephone Network), which is connected to a triangle labeled 'VAP' (Videotex Access Point), which is connected to an oval labeled 'HAN' (Host Access Network), which is finally connected to a rectangle labeled 'VH' (Videotex Host). The diagram is identified by the code T0808560-91/d05. + +FIGURE A.4/T.104 +**Connection via a VAP** + +The connection establishment with the host does not have any influence on the protocol stack between the terminal and the VAP. As far as the terminal is concerned, only a connection to the VAP exists. In terms of the protocol stack there is an end-to-end connection on layer 3 between the two sides, with an Application Layer on top. See Figure A.5. + +### A.3.1 Service selection after a dialogue with the VAP + +The terminal is connected to a VAP, which sets up a second connection to a server after some dialogue between the terminal and the VAP. This is basically a refinement of the access to a VH. See Figure A.6. + +### A.3.2 Service selection using a VS identification + +A connection is established between the terminal and the VAP. On this connection, layer 2 and layer 3 are set up. The layer 3 CALL REQUEST carries the address or the name of the requested application. This information is used by the VAP to establish an end-to-end dialogue between the terminal and the VH. See Figure A.7. + +![Protocol stack for VT-VAP-VH connection diagram](d4af765160d04ecef538e5066006dc77_img.jpg) + +The diagram illustrates the protocol stack for a VT-VAP-VH connection. It shows three vertical stacks of protocol layers. The stacks are labeled VT, VAP, and VH at the bottom. Above each stack is a box representing the application layer: 'Terminal Application' for VT, 'Access functionality' for VAP, and 'Host Application' for VH. The layers are numbered 1, 2, 3, and 7 from bottom to top. The layers are connected as follows: + +- Layer 7: Terminal Application connects to VAP's layer 7, which connects to Host Application. +- Layer 3: VT's layer 3 connects to VAP's layer 3, which connects to VH's layer 3. +- Layer 2: VT's layer 2 connects to VAP's layer 2, which connects to VH's layer 2. +- Layer 1: VT's layer 1 connects to VAP's layer 1, which connects to VH's layer 1. + +The VAP stack is positioned between the VT and VH stacks, with its 'Access functionality' box spanning two adjacent layer stacks (both containing layers 1, 2, 3, and 7). + +T0808570-91/d06 + +Protocol stack for VT-VAP-VH connection diagram + +FIGURE A.5/T.104 +**Protocol stack for VT-VAP-VH connection** + +![Connection establishment after dialogue diagram](042733dc5e8e7f5f30b60adba3266cde_img.jpg) + +The diagram shows the sequence of events for connection establishment after a dialogue. It features a sequence of components: VT (represented by a triangle), PSTN (represented by a dashed oval), VAP (represented by a triangle), HAN (represented by a dashed oval), and VH (represented by a rectangle). Below this sequence, seven horizontal double-headed arrows indicate the duration of different phases: + +- Layer 1 establishment: spans from VT to VAP. +- Layer 2 establishment: spans from VT to VAP. +- Layer 3 establishment: spans from VT to VAP. +- Dialogue set-up: spans from VT to VAP. +- Dialogue: spans from VT to VAP. +- Dialogue set-up: spans from VAP to VH. +- Dialogue: spans from VT to VH. + +The 'Dialogue' phase from VT to VH is the longest, encompassing the previous phases. + +T0808580-91/d07 + +Connection establishment after dialogue diagram + +FIGURE A.6/T.104 +**Connection establishment after dialogue** + +![Diagram of connection establishment without dialogue between VT, PSTN, VAP, HAN, and VH.](af7916c89a458fdab6c3f443217388ae_img.jpg) + +The diagram illustrates the connection establishment process between a Video Terminal (VT) and a Video Host (VH) via a Video Access Point (VAP) and a Host Access Network (HAN). The connection path is VT → PSTN → VAP → HAN → VH. Below the network diagram, five horizontal double-headed arrows represent the sequence of operations: + + +- Layer 1 establishment: spans from VT to VAP. +- Layer 2 establishment: spans from VT to VAP. +- Layer 3 establishment: spans from VT to VAP. +- Dialogue set-up: spans from VAP to VH. +- Dialogue: spans the entire path from VT to VH. + + The reference code T0808590-91/d08 is located at the bottom right of the diagram area. + +Diagram of connection establishment without dialogue between VT, PSTN, VAP, HAN, and VH. + +FIGURE A.7/T.104 +Connection establishment without dialogue + +#### A.3.2.1 VS identified by a network address + +The application is selected by its VH-address on the Host Access Network. This address is inserted in the layer 3 CALL REQUEST and interpreted by the VAP to establish a connection with the VH. + +*Example* – Assume that the VH-address is “12345678”. This number is inserted in the layer 3 CALL REQUEST sent by the terminal to the VAP. + +*NOTE* – Some user data (e.g. user-identification) may be associated with the VH-address. It will be conveyed transparently from the terminal to the VH. + +#### A.3.2.2 VS identified by a name + +The requested application is identified by a Videotex Service name. This name is inserted by the terminal in the layer 3 CALL REQUEST and interpreted by the VAP to establish the appropriate connection. + +*Example* – Assume that the Videotex service name is “ETSI”. This name is inserted in the layer 3 CALL REQUEST and translated by the VAP into the VH-address “12345678”. + +#### A.3.2.3 Establishment of the second VC by the VT + +The terminal is connected to the VAP using a VC. The terminal may establish a second VC to connect to VH2. + +The terminal shall present all the information which is received on the two different VCs. See Figure A.8. + +![Diagram of distributed hosts via two VCs initiated by the VT.](5dfc130b129ace4df375839020a5700d_img.jpg) + +The diagram shows a Video Terminal (VT) connected to a Video Access Point (VAP) via a Public Switched Telephone Network (PSTN). The VAP is connected to two separate Host Access Networks (HAN1 and HAN2), which are in turn connected to Video Hosts (VH1 and VH2). Below the network diagram, four horizontal double-headed arrows represent the sequence of operations: + + +- Dialogue VH1: spans from VT to VH1. +- Connect set-up VH2: spans from VT to VH2. +- Dialogue VH2: spans from VT to VH2. + + The reference code T0808600-91/d09 is located at the bottom right of the diagram area. + +Diagram of distributed hosts via two VCs initiated by the VT. + +FIGURE A.8/T.104 +Distributed hosts via two VC s initiated by the VT + +## A.4 Host to terminal call establishment + +In all configurations described above, the initiative to establish the connection may also be taken by a VAP. Therefore, a terminal should be able to respond to incoming calls. The topology of the network behind the VAP is irrelevant. See Figure A.9. + +![Diagram of Host to terminal call establishment topology and sequence.](4ee27dbf5ef12e7b58b0ef0937bc5a5e_img.jpg) + +The diagram illustrates the topology and sequence for host-to-terminal call establishment. The topology shows a triangle labeled 'VT' connected to a dashed oval labeled 'PSTN', which is then connected to a triangle labeled 'VAP'. Below the topology, three horizontal double-headed arrows represent the establishment sequence: 'Layer 1 establishment', 'Layer 2 establishment', and 'Layer 3 establishment'. The identifier 'T0808610-91/d10' is located at the bottom right of the diagram. + +Diagram of Host to terminal call establishment topology and sequence. + +FIGURE A.9/T.104 +Host to terminal connection establishment + +## A.5 Terminal to terminal communication + +If the VAP in the above Figure A.9 is replaced by another terminal, the resulting configuration allows for a direct terminal to terminal communication, as shown in Figure A.10. + +![Diagram of Terminal to terminal communication topology and sequence.](1b5a812c8aa20fd5cba28e97001d32de_img.jpg) + +The diagram illustrates the topology and sequence for terminal-to-terminal communication. The topology shows a triangle labeled 'VT' connected to a dashed oval labeled 'PSTN', which is then connected to another triangle labeled 'VT'. Below the topology, three horizontal double-headed arrows represent the establishment sequence: 'Layer 1 establishment', 'Layer 2 establishment', and 'Layer 3 establishment'. The identifier 'T0808620-91/d11' is located at the bottom right of the diagram. + +Diagram of Terminal to terminal communication topology and sequence. + +FIGURE A.10/T.104 +Terminal to terminal communication + +After establishment of layer 3, none of the service selection procedures are applicable. The application layer protocol does not contain any special support for this configuration. + +# **Annex B****Usage of supplementary services** + +Annex B/T.105 [3] does not apply. + +# **Annex C****Terminal Function basic state** + +Annex C/T.105 [3] applies. In addition, the default value for parameter reference 11 is in accordance with the modem speed. + +# **Annex D****The SBV-Escape service** + +Annex D/T.105 [3] applies. + +# **Annex E****Extended data forwarding signals** + +Annex E/T.105 [3] applies. + +# **Annex F****Operating sequences for V.29 short turn around** (This annex forms an integral part of this Recommendation) + +## **F.1 Turn-ON sequence at 9600/7200 bits per second** + +During the interval between the OFF to ON transition of circuit 105 and the OFF to ON transition of circuit 106, synchronizing signals for proper conditioning of the receiving modem shall be generated by the transmitting modem. These signals are used to establish carrier detect, AGC if required, timing synchronization, equalizer convergence and descrambler synchronization. + +The synchronization signals are defined in two separate sequences. The long one shall be used once at the beginning of the established connection. The short one may be used for all subsequent turn around in which the equalizer pattern is used to update and refine equalizer convergence. + +NOTE – The facsimile service shall not use the short turn around. For the telematic services making use of Recommendation T.71, the short turn around shall be used except during the connection establishment time. + +Two sequences are defined: + +- a) a short one for turn around operation; +- b) a longer one for initial establishment of the connection. + +The sequence b) is only used after the first OFF to ON transition of circuit 105 following the OFF to ON transition of circuit 107, or at the OFF to ON transition of circuit 107 if the circuit 105 is already ON. After every subsequent OFF to ON transition of circuit 105, the sequence a) is used. + +The sequences, for both 9600 and 7200 data rates, are divided into five segments as in Table F.1. + +TABLE F.1/T.104 + +### **RTS/CTS Turn-ON sequence** + +| | Segment 1 | Segment 2 | Segment 3 | Segment 4 | Segment 5 | Total | +|-------------------------|------------------------|-----------------------|--------------|--------------------------------|---------------------------|--------| +| Type of line signal | Unmodulated carrier | No transmitted energy | Alternations | Equalizer conditioning pattern | Scrambled all binary ONEs | | +| Protection against echo | a) | 48 SI | 100 SI | 62 SI | 18 SI | 228 SI | +| | 185 ms
to
200 ms | 20 ms | 42 ms | 25 ms | 8 ms | 280 ms | +| | | 48 SI | 128 SI | 384 SI | 48 SI | 608 SI | +| | b) | 20 ms | 53 ms | 160 ms | 20 ms | 438 ms | +| Without any protection | a) | | 100 SI | 62 SI | 18 SI | 180 SI | +| | 0 ms | 0 ms | 42 ms | 25 ms | 8 ms | 75 ms | +| | | 48 SI | 128 SI | 384 SI | 48 SI | 608 SI | +| b) | 0 ms | 20 ms | 53 ms | 160 ms | 20 ms | 253 ms | + +Segment 3 of the synchronizing signal consists of alternations between two signal elements as described in 8.1/V.29. The duration of segment 3 is given in Table F.1. + +Segment 4 of the synchronizing signal transmits two signal elements according to an equalizer condition pattern as described in 8.2/V.29 [8]. The duration of segment 4 is given in Table F.1. + +Segment 5 commences transmission according to the encoding described in 2.2/V.29 [8] with continuous binary ONEs applied to the input of the data scrambler. At the end of segment 5, circuit 106 is turned ON and user data are applied to the input of the data scrambler. The duration of segment 5 is given in Table F.1. + +## F.2 Turn-ON sequence at 4800/2400 bit/s + +When operating in the fallback mode at 4800 or 2400 bit/s, the modem shall conform to the turn-ON and Turn-OFF sequences given in V.27 *ter* [7]. + +## **F.3 Turn-OFF sequence** + +With or without protection against talker echo, the line signal emitted after the ON to OFF transition of circuit 105 shall consist of a segment A followed by a segment B. + +Segment A shall consist of remaining data followed by continuous scrambled ONEs for a total duration in the range of 5 to 10 ms. + +Segment B shall consist of a period of 20 ms of no transmitted energy. + +The total duration for TURN-OFF time shall then be in the range 25-30 ms. + +If an OFF to ON transition of circuit 105 occurs during the turn-OFF sequence, it will not be taken into account until the end of the turn-OFF sequence. + +In addition, if circuit 105 goes ON during the reception of the segment A of the turn-OFF sequence, optionally the transmission of the turn-ON sequence shall be started within a time period of less than 20 ms after the reception of segment A. + +## **F.4 Circuit 109** + +Circuit 109 shall turn ON after synchronizing is completed and prior to user data appearing on circuit 104. Circuit 109 is prevented from turning ON during reception of unmodulated carrier when the optional protection against talker echo is used. + +## **F.5 Circuit 106** + +Circuit 106 response times are from the connection of an ON or OFF condition on: + +- circuit 105 to the appearance of the corresponding ON or OFF condition on circuit 106; or +- circuit 107 (where circuit 105 is already ON) to the appearance of the corresponding ON or OFF condition on circuit 106. \ No newline at end of file diff --git a/marked/T/T-REC-T.106-199303-I_PDF-E/raw.md b/marked/T/T-REC-T.106-199303-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..4d64fa479d224f23bbec80aa624a3ed3e5768b85 --- /dev/null +++ b/marked/T/T-REC-T.106-199303-I_PDF-E/raw.md @@ -0,0 +1,190 @@ + + +![ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## T.106 + +(03/93) + +**TELEMATIC SERVICES** + +**TERMINAL EQUIPMENTS AND PROTOCOLS +FOR TELEMATIC SERVICES** + +--- + +**FRAMEWORK OF VIDEOTEX TERMINAL +PROTOCOLS** + +**ITU-T Recommendation T.106** + +(Previously "CCITT Recommendation") + +--- + +# FOREWORD + +The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecommunication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +ITU-T Recommendation T.106 was prepared by the ITU-T Study Group VIII (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). + +# --- NOTES + +1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector. + +In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms “CCITT, CCIR or IFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. + +2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# CONTENTS + +| | Page | +|----------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 Normative references ..... | 1 | +| 3 Overall structure of protocols in various environments ..... | 2 | +| 3.1 Data Syntaxes Applicable to Videotex Terminals ..... | 3 | +| 3.2 ISDN circuit mode ..... | 3 | +| 3.3 ISDN packet mode ..... | 3 | +| 3.4 PSTN packet mode ..... | 3 | +| 4 Syntax-based Videotex Application layer protocol ..... | 3 | +| 5 Existing protocols of SPTN circuit switched mode ..... | 3 | + + + +# FRAMEWORK OF VIDEOTEX TERMINAL PROTOCOLS + +(Helsinki, 1993) + +# 1 Scope + +Videotex is a public access information system which allows for the connection of a variety of terminal equipment to databases of information (servers) or to other terminals over widely available public telecommunications facilities. Initially terminals were connected to information servers over the conventional public switched telephone network (PSTN). This was accomplished using low cost modems: typically at 1200/75 or 1200/1200 bits/s. With the introduction of ISDN and improved modem facilities a number of other optional configurations are becoming viable for the connection of videotex terminals to server systems. These include higher speed conventional modems at 2400 or 4800 bits/s, much higher speed modems such as 9600 bit/s (see Recommendations V.29 [10] and V.32 [11]) or 14 400 bit/s (see Recommendation V.17 [9]) and ISDN connections using packet mode on a B or D channel and circuit switched mode. + +A number of videotex communications configurations are possible using these new communications facilities. This Recommendation describes the method by which these facilities shall be used in videotex. + +This Recommendation describes the application layer and lower layer protocols which shall be used for terminal to videotex systems operating over various types of networks. This includes: + +- ISDN 64 kilobit/s circuit mode; +- ISDN 64 kilobit/s packet mode; +- ISDN D channel packet mode; +- PSTN packet mode operation using V-Series modems. + +In addition the existing PSTN based videotex services are identified, which primarily make use of relatively low speed modems over the PSTN or equivalent networks. + +This Recommendation also identifies the data syntaxes used in the various configurations within the various regions of the world, together with the common data syntaxes for audio and photographic information. The relationships between the various Recommendations applicable to videotex are defined. + +# 2 Normative references + +- [1] CCITT Recommendation T.101, *International interworking for videotex services.* +- [2] CCITT Recommendation T.102, *Syntax-Based End-to-end Protocols for the Circuit mode ISDN.* +- [3] CCITT Recommendation T.103, *Syntax-Based End-to-end Protocols using the Packet Mode ISDN.* +- [4] CCITT Recommendation T.104, *Packet Mode access for Syntax-Based Videotex via PSTN.* +- [5] CCITT Recommendation T.105, *Syntax-based videotex application layer protocol.* +- [6] CCITT Recommendation F.300, *Videotex service.* +- [7] ISO 2022, *Information Processing – ISO 7-bit and 8-bit coded character sets – Code extension techniques.* +- [8] ISO/IEC 9281, *Information technology – Picture coding methods.* +- [9] CCITT Recommendation V.17 (1990), *Recommendation for a 2-wire modem for facsimile applications with rates up to 14 400 bit/s.* + +- [10] CCITT Recommendation V.29 (1988), *9600 bits/s modem standardized for use on point to point 4 wire leased telephone type circuits.* +- [11] CCITT Recommendation V.32 (1988), *A family of 2-wire, duplex modems operating at data signalling rates of up to 9600 bit/s for use on the general switched telephone network and on leased telephone type circuits.* + +# 3 Overall structure of protocols in various environments + +As identified in Recommendation F.300 [6] various configurations are permitted for the structure of a videotex system. A terminal can be connected to a host server: + +- directly by a telecommunication network; +- via a Packet Assembler Disassembler (PAD); +- via a Videotex Access Point (VAP); or +- via a Videotex Service Center (VSC) which may also act as a videotex host. + +All of these configurations are currently in use. In all of the identified configurations listed above there exists an access function which is located either in the host or in the VAP or in the VSC. + +With the development of new types of networks and progress in modem technology it is necessary to define the protocol between the terminal and the access function. For this reason a series of Recommendations have been developed addressing the protocol aspects between the terminal and the access function of the videotex service. + +Recommendations have been defined identifying the access protocols for three different types of networks. + +The relationships between these standards, including the videotex syntax Recommendation are illustrated in Figure 1. + +![Diagram illustrating the relationships between videotex Recommendations. T.106 'Framework of Videotex Terminal Protocols' is the central component. It connects to T.101 Videotex Data syntaxes (Annex B, C, D, E, F), T.102 ISDN 'Circuit mode', T.103 ISDN 'Packet mode', T.104 PSTN 'Packet mode', and T.105 Syntax-based Videotex Application layer protocol. Existing Services are shown as a separate entity.](6df5629bc2fc6d82f1a1edf9d7340113_img.jpg) + +``` + +graph TD + T106[T.106 "Framework of Videotex Terminal Protocols"] + T101[T.101 Videotex Data syntaxes: +Annex B (DS I) +Annex E (Audio) +Annex C (DS II) +Annex F (Photo) +Annex D (DS III)] + T102[T.102 ISDN +"Circuit mode"] + T103[T.103 ISDN +"Packet mode"] + T104[T.104 PSTN +"Packet mode"] + T105[T.105 Syntax-based Videotex Application layer protocol] + ES[Existing Services] + + T106 --> T101 + T106 --> T102 + T106 --> T103 + T106 --> T104 + T106 --> T105 + T102 --> T105 + T103 --> T105 + T104 --> T105 + ES -.- T106 + +``` + +T0808500-91/d01 + +Diagram illustrating the relationships between videotex Recommendations. T.106 'Framework of Videotex Terminal Protocols' is the central component. It connects to T.101 Videotex Data syntaxes (Annex B, C, D, E, F), T.102 ISDN 'Circuit mode', T.103 ISDN 'Packet mode', T.104 PSTN 'Packet mode', and T.105 Syntax-based Videotex Application layer protocol. Existing Services are shown as a separate entity. + +FIGURE 1/T.106 +Relationships between videotex Recommendations + +## **3.1 Data Syntaxes Applicable to Videotex Terminals** + +The representation of application data elements in syntax based videotex systems is accomplished by the use of a number of defined data syntaxes. Videotex services have been implemented in different countries/regions making use of different data syntaxes referred as Data Syntax I, Data Syntax II and Data Syntax III, which have an equal status. + +These data syntaxes are described in Annexes B/T.101, C/T.101 and D/T.101 [1], respectively. Any of these data syntaxes may be used with the protocols given below (see 3.2 to 3.4). In combination with any of these three base data syntaxes, two common enhancements are defined addressing audio and photographic capabilities (see Annexes E/T.101 and F/T.101 [1], respectively). + +The Terminal Facility Identifier (TFI), defining the mechanism for allowing a videotex service to recognize the possibilities of a terminal, is described in clause 9/T.101 [1]. + +The switching mechanism between the data syntaxes is based on ISO 2022 [7] and ISO/IEC 9281 [8] as described in clause 9/T.101 [1]. The ESC 2/5 F mechanism to introduce a complete coding environment may be used to select the base data syntaxes (DS I, DS II, DS III). The ISO/IEC 9281 picture coding environment switching technique based on ESC 7/0 CMI LI is used to establish the common audio and photo extensions. + +## **3.2 ISDN circuit mode** + +Recommendation T.102 [2] describes the lower layers (1-3) applicable to ISDN circuit mode of operation. It describes the additional aspects of the End-to-end protocol for ISDN circuit mode, making reference to Recommendation T.105 [5] for the relevant common aspects of the End-to-end protocol. + +## **3.3 ISDN packet mode** + +Recommendation T.103 [3] describes the lower layers (1-3) for ISDN packet mode operation on the B channel and the D channel. It also describes the additional aspects of the End-to-end protocol applicable to ISDN packet mode, making reference to Recommendation T.105 [5] for the relevant common aspects of the End-to-end protocol. + +## **3.4 PSTN packet mode** + +Recommendation T.104 [4] describes the lower layers for packet mode operation on the PSTN. It also describes the additional aspects of the End-to-end, protocols operation, making references to Recommendation T.105 [5] for the relevant common aspects of the End-to-end protocol. + +# **4 Syntax-based Videotex Application layer protocol** + +Recommendation T.105 [5] describes the application layer protocol common to all Syntax based Videotex Recommendations. This Recommendation consists of the description of service, protocol and coding applicable to Syntax-based Videotex. + +# **5 Existing protocols of SPTN circuit switched mode** + +A number of different application and lower layer protocols are in use throughout the world. These services are primarily regionally or nationally defined. In these protocols both 7 and 8-bit channels are used as well as a number of different V-Series modems. + +These existing base videotex systems are in wide use. In order to introduce functionalities in a compatible manner, PSTN based systems may be upgraded using higher speed modems without modifying the lower layers already in use. When introducing enhancements to the existing system (e.g. the use of higher speed modems), the lower layer and application layer protocols used are those defined in the existing services. \ No newline at end of file diff --git a/marked/T/T-REC-T.120-200701-I_PDF-E/raw.md b/marked/T/T-REC-T.120-200701-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..cd7bc1d5fae86ac61021c6df765a8de69603a3d1 --- /dev/null +++ b/marked/T/T-REC-T.120-200701-I_PDF-E/raw.md @@ -0,0 +1,1054 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**T.120** + +(01/2007) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES + +--- + +# **Data protocols for multimedia conferencing** + +ITU-T Recommendation T.120 + + + +## **ITU-T Recommendation T.120** + +# **Data protocols for multimedia conferencing** + +## **Summary** + +The T.120-series Recommendations collectively define a multipoint data communication service for use in multimedia conferencing environments. The purpose of ITU-T Recommendation T.120 is to provide an introduction and guide to the T.120 series. ITU-T Recommendation T.120 defines the T.120 architectural model and shows the interrelationships between the constituent Recommendations. Each Recommendation in the series is outlined and the requirements for T.120 compliance are specified. Annex A specifies T.120 channel and token allocations. Annex B specifies MCS domain parameters. Annex C specifies lightweight profiles for the T.120 architecture. + +This revised version of ITU-T Recommendation T.120 introduces a number of clarifications to the previous version. + +## **Source** + +ITU-T Recommendation T.120 was approved on 13 January 2007 by ITU-T Study Group 16 (2005-2008) under the ITU-T Recommendation A.8 procedure. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2007 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +# CONTENTS + +| | Page | +|-------------------------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Abbreviations and acronyms ..... | 1 | +| 4 Overview ..... | 2 | +| 5 Introduction to multipoint multimedia communication..... | 3 | +| 6 The T.120 system model ..... | 5 | +| 6.1 User applications ..... | 6 | +| 6.2 Application protocols ..... | 7 | +| 6.3 Node controller..... | 7 | +| 6.4 Communications infrastructure ..... | 7 | +| 6.5 Networks..... | 8 | +| 7 T.120 infrastructure Recommendations ..... | 8 | +| 7.1 Protocol stacks for audiographic and audiovisual conferencing –
[ITU-T T.123]..... | 8 | +| 7.2 Multipoint communication service (MCS) – [ITU-T T.122],
[ITU-T T.125]..... | 9 | +| 7.3 Generic conference control (GCC) – [ITU-T T.124] ..... | 10 | +| 8 Application protocol Recommendations ..... | 10 | +| 8.1 The generic application template (GAT) – [ITU-T T.121] ..... | 10 | +| 8.2 Multipoint still image and annotation protocol (MSIA) – [ITU-T T.126]..... | 11 | +| 8.3 Multipoint binary file transfer (MBFT) – [ITU-T T.127] ..... | 11 | +| 8.4 T.120 extensions for audiovisual control – For further study ..... | 12 | +| 8.5 Proprietary extensions to standardized protocols ..... | 12 | +| 8.6 Non-standard application protocols..... | 12 | +| 9 T.120 compliance ..... | 12 | +| Annex A – T.120 channel and token allocations ..... | 14 | +| A.1 Static channels ..... | 14 | +| A.2 Static tokens..... | 14 | +| A.3 Standard application protocol session identifiers ..... | 14 | +| Annex B – MCS domain parameters ..... | 15 | +| Annex C – Lightweight profiles for the T.120 architecture..... | 17 | +| C.1 Lite T.123 profile..... | 18 | +| C.2 Lite T.122/T.125 profile ..... | 18 | +| C.3 Lite T.124 profile..... | 24 | +| C.4 Lite T.121 profile..... | 37 | + + + +## ITU-T Recommendation T.120 + +## Data protocols for multimedia conferencing + +# 1 Scope + +This Recommendation introduces a suite of standards, collectively referred to as the T.120 series. + +This Recommendation describes the T.120 system model that provides an architecture for multipoint data communication in a multimedia conferencing environment. It provides an introduction and functional description of the Recommendations that go to make up the T.120 infrastructure. In addition, it provides an overview to other Recommendations in the series that provide standardized application protocol functionality. + +This Recommendation defines the criteria for compliance when the T.120 data protocols are used in a conferencing or group-working environment. + +This Recommendation only covers completed work contained in approved Recommendations. When new Recommendations are approved, supporting text will be generated for inclusion in this Recommendation at the next publication date. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T T.121] ITU-T Recommendation T.121 (1996), *Generic application template*. + +[ITU-T T.122] ITU-T Recommendation T.122 (1998), *Multipoint communication service – Service definition*. + +[ITU-T T.123] ITU-T Recommendation T.123 (2007), *Network-specific data protocol stacks for multimedia conferencing*. + +[ITU-T T.124] ITU-T Recommendation T.124 (2007), *Generic conference control*. + +[ITU-T T.125] ITU-T Recommendation T.125 (1998), *Multipoint communication service protocol specification*. + +[ITU-T T.126] ITU-T Recommendation T.126 (1997), *Multipoint still image and annotation protocol*. + +[ITU-T T.127] ITU-T Recommendation T.127 (1995), *Multipoint binary file transfer protocol*. + +# 3 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|--------|-----------------------------------------------| +| APE | Application Protocol Entity | +| ARM | Application Resource Manager | +| ASE | Application Service Element | +| B-ISDN | Broadband Integrated Services Digital Network | + +| | | +|------|-----------------------------------------------------------| +| CSDN | Circuit Switched Data Network | +| GAT | Generic Application Template | +| GCC | Generic Conference Control | +| ISDN | Integrated Services Digital Network | +| LAN | Local Area Network | +| MBFT | Multipoint Binary File Transfer | +| MCS | Multipoint Communication Service | +| MCU | Multipoint Control Unit | +| MSIA | Multipoint Still Image and Annotation | +| PDU | Protocol Data Unit | +| PSDN | Packet Switched Data Network | +| PSTN | Public Switched Telephone Network | +| QoS | Quality of Service | +| SI | Still Image (SI is a commonly used abbreviation for MSIA) | + +# 4 Overview + +The T.120-series Recommendations collectively define a multipoint communication service for use in multimedia conferencing environments. The purpose of this Recommendation is to provide an introduction and guide for the T.120 series, showing the interrelationships between the constituent Recommendations and to define the requirements for compliance to this Recommendation for conferencing. + +This Recommendation provides facilities to establish and manage interactive communications (conferences) involving two or more participants on and between a variety of different networks. It provides a comprehensive data communication service for those participants, which is independent of the underlying network. Within a conference it allows communications to be established between any combination of conference participants. This Recommendation also provides support for applications and their associated protocols, defining start-up mechanisms and capability exchange procedures, etc. + +This Recommendation makes provisions to ensure interoperability of commonly required functionality such as file transfer, still image exchange and shared whiteboards through the definition of standardized application protocols. + +The T.120 protocols provide a means of telecommunicating many forms of Data/Telematic information between two or more multimedia terminals and of managing such communication. They provide a multipoint data communication service that has a particular application in multimedia conferencing. + +The T.120 protocols are suitable for use on many types of network: PSTN, ISDN, CSDN, PSDN, B-ISDN, LANs. They provide the capability for seamless interworking of applications between terminals connected to different networks. + +The T.120 protocols provide: + +- support for conference establishment among a group of network nodes (such as conference terminals and MCUs); +- mechanisms to identify the participating nodes and a comprehensive roster and capability exchange mechanism; + +- flexible management of communication between any combination of these elements. + +The T.120 protocols can handle one or more simultaneous conferences. A terminal may participate in more than one of these if authorized to do so. The *convenor* of a conference may control the participation in that conference and the information which flows in that conference. + +In a conference that allows conductorship, the convenor may delegate part or all authority to the conductor. If a conference enters conducted mode, application protocols that are "conductor aware" modify their behaviour, as specified by their protocol for this mode of operation. + +This Recommendation imposes few inherent constraints on the configuration of connections between conference nodes (terminals and MCUs): but they must be arranged in a hierarchy, with a single node at the top of a tree. Nodes may be all connected to one star-point, or connected one to two others in a chain, or a chain of star-points, and so on, as long as it is clear for each connection which direction is upward and there are no loops. The top node should be present from the beginning of a conference, since any change in the top can be disruptive. + +No constraint is placed on the rate or volume of information transmitted within the various media; the T.120 protocols have the capability to organize different rates of information flow, within the constraints imposed by the type of network and connections established thereon. They allow relative priorities to be set by the applications using the T.120 protocols. + +The structure of the T.120 protocols is described in clause 6. Not all of the T.120 protocol provisions are mandatory: T.123, T.122/125, and T.124 are mandatory for conferencing and group working environments. The remainder are conditional: where functionality covered by the standards is provided, the standard protocols of the T.120 series must be implemented (see clause 9 for T.120 compliance requirements). This ensures that it is always possible to achieve a basic level of interworking, and does not prohibit customized enhancements and negotiation of proprietary modes if (and only if) all participating elements are able to support such modes. + +# **5 Introduction to multipoint multimedia communication** + +Traditionally, telephony services have been constrained to point-to-point operation. In order to support group activities such as meetings, conferences etc., involving physically separated participants, there is a requirement to join together more than two locations. The term "multipoint communication" simply describes the interconnection of multiple terminals. Normally, a special network element, known as a Multipoint Control Unit (MCU), or more simply a bridge, is required in order to provide this function. + +A conference typically refers to a group of geographically dispersed nodes that are electronically joined together and that are capable of exchanging audiographic and audiovisual information across various communication networks. + +Conference participants may have access to various types of media handling capabilities such as audio only (telephony), audio and data, audio and video, or audio, video and data. + +The T.120 series of Recommendations define the component which is used to provide both a data communications service, and a management service for any other media services present. + +T.120 protocols provide the infrastructure required to provide data services for many types of conferencing and group working, making it suitable for a diverse range of application areas. It is expected to find use in videotelephony and audiographic conferencing as well as other forms of multipoint multimedia communication. + +This Recommendation regards point-to-point connections as the simplest form (a degenerate case) of a multipoint connection. Both forms of connection are supported by the T.120 protocols. Terminals with multiple communication ports (each with an appropriate T.120 transport stack) can act as T.120 data bridges and allow multipoint connections to be established involving three or + +more nodes. Figure 1 b) shows a four site conference with multipoint terminals acting as data bridges. + +MCUs are nodes that do not normally support terminal functionality. They act as bridging nodes, bridging data and other media streams present in the connections. Figure 1 c) shows an example of how three MCUs may be connected to bridge a group of terminals. + +![Figure 1: Examples of multipoint conference configurations showing various connection topologies and node types.](cfda9df1319e04207eb28bcefd1dab7b_img.jpg) + +The diagram illustrates three different network topologies for multipoint conferences: + +- a) Point-to-point**: Shows two 'Terminal' nodes connected by a single line. Below the diagram is the text: **a) Point-to-point** (The simplest case of a multipoint connection). +- b) Chain connection with terminals acting as data bridges**: Shows a linear sequence of four nodes: 'Terminal' — 'Multipoint Terminal' — 'Multipoint Terminal' — 'Terminal'. Below the diagram is the text: **b) Chain connection with terminals acting as data bridges**. +- c) Multipoint topology**: Shows a hierarchical structure with three 'MCU' nodes at the top level. The left MCU connects to two 'Terminal' nodes. The right MCU connects to two 'Terminal' nodes. The top MCU connects to both the left and right MCUs. Additionally, the right MCU connects to a third 'Terminal' node. Below the diagram is the text: **c) Multipoint topology** 3 MCUs providing connections to allow multiple terminals to participate in a conference. + +T.120(01-07)\_F01 + +Figure 1: Examples of multipoint conference configurations showing various connection topologies and node types. + +**Figure 1 – Examples of multipoint conference configurations showing various connection topologies and node types** + +Figure 2 is an example of a conference that involves terminals of diverse capability, on multiple different networks and across administrations. + +![Diagram of a mixed-network conference topology showing Corporate network A, Corporate network B, and a Public network connected via ISDN and PSTN.](5b4e774d63e0e0ed73801a9247755e5f_img.jpg) + +The diagram illustrates a mixed-network conference topology. It consists of three main sections: Corporate network A, Corporate network B, and a Public network. + +- Corporate network A:** Contains three terminals connected to a LAN gateway (router). +- Corporate network B:** Contains three terminals connected to a LAN gateway (router). +- Public network:** Contains two MCUs (Multipoint Control Units) connected via ISDN. The first MCU is connected to two terminals via ISDN. The second MCU is connected to the first MCU via ISDN. The second MCU is connected to a multipoint terminal via PSTN. This multipoint terminal is connected to another multipoint terminal via PSTN, which is then connected to a terminal via PSTN. + +Connections between Corporate network A and Corporate network B are established via ISDN links connecting their respective LAN gateways to the first MCU in the Public network. + +T.120(01-07)\_F02 + +Diagram of a mixed-network conference topology showing Corporate network A, Corporate network B, and a Public network connected via ISDN and PSTN. + +**Figure 2 – Example of a mixed-network conference topology** + +# 6 The T.120 system model + +The T.120 model is comprised of a communications infrastructure and the application protocols that make use of it. Figure 3 shows the full model with both standardized and non-standardized applications. The model serves to show both the scope of the T.120 series of Recommendations (indicated by the shaded background) and the relationship between each of the Recommendations and other components in the system. + +Generally, each layer provides services to the layer above and communicates to its peer(s) by sending Protocol Data Units (PDUs) via services provided by the layer below. + +This clause will address each of the major functional levels in Figure 3: User applications, Application protocols, Node controller, Communications infrastructure and Networks. + +![Figure 3 – T.120 system model diagram showing the architecture of the T.120 system model.](d4af765160d04ecef538e5066006dc77_img.jpg) + +The diagram illustrates the T.120 system model architecture, organized into several layers and components: + +- User Applications Layer:** At the top, there are three boxes representing user applications: + - Left: "User application(s) (using standard application protocols)" + - Center: "Node controller" + - Right: "User application(s) (using non-standard protocols)" + These are connected to the underlying infrastructure via bidirectional arrows. +- Application Protocol Entities Layer:** Below the user applications, there are two main groups of entities: + - Standard Protocols:** A stack of boxes representing "ITU-T Rec. T.127 (MBFT)", "ITU-T Rec. T.126 (SI)", and "Application protocol entity". These are grouped under the label "ITU-T Rec. T.120 application protocol Recommendations". + - Non-standard Protocols:** A stack of boxes representing "Non-standard application protocol entity". +- Core Services Layer:** In the center, there are two main service blocks: + - Generic conference control (GCC):** Labeled "ITU-T Rec. T.124". + - Multipoint communication service (MCS):** Labeled "ITU-T Recs T.122 and T.125". + These two blocks are connected to each other and to the layers above and below them. +- Network-Specific Transport Protocols Layer:** At the bottom, there is a block labeled "Network-specific transport protocols" with the reference "ITU-T Rec. T.123". +- Infrastructure Layer:** The entire system is supported by "ITU-T Rec. T.120 infrastructure Recommendations", which forms the base of the model. + +Arrows indicate the flow of data and control between these components, showing a hierarchical and interconnected structure. + +T.120(01-07)\_F03 + +Figure 3 – T.120 system model diagram showing the architecture of the T.120 system model. + +**Figure 3 – T.120 system model** + +## 6.1 User applications + +Applications *per se* are not the subject of standardization in the T.120-series Recommendations. Applications that use the services offered by the T.120 series Recommendations will generally be multipoint aware and designed to use the T.120 services provided by GCC and MCS. These applications are termed "User Applications" and they may use any combination of standardized and non-standard protocols to communicate with peer user applications. The T.120 environment supports multiple user applications concurrently operating in the same conference by providing mechanisms for the applications to coordinate the use of communications resources. The Generic Application Template [ITU-T T.121] provides guidance to user application developers on how to utilize the T.120 infrastructure in a coherent and consistent way. A user application addresses those tasks which have no direct effect on interworking (e.g., user interface) and which may thus be product and platform specific. The influence of the user application is felt at other sites through the application protocols it employs. + +## **6.2 Application protocols** + +Application protocols comprise a set of protocol data units (PDUs) and associated actions for application peer-to-peer(s) communication. These may be proprietary protocols or they may be standardized by the ITU-T or other international or national standards bodies. The T.120 series Recommendations includes a set of application protocols designed to meet the needs of multipoint conferencing. These protocols define minimum requirements in order to ensure interworking between different implementations. [ITU-T T.127] provides simultaneous multipoint file transfer. [ITU-T T.126] provides still image viewing and annotation, shared whiteboard, and facsimile. A given application may use any combination of standardized and non-standard application protocols. + +An Application Protocol Entity is an instance of an application protocol. It may be considered as comprising of two functional components: the application resource manager (ARM), that provides the generic functionality relevant to all protocols; and the application service element (ASE), that provides the application-specific functionality. Both of these are described further in the T.121 generic application template recommendation. [ITU-T T.121] presents templates and guidelines which may assist in the definition of new application protocols. + +## **6.3 Node controller** + +The node controller is the element that provides the T.120 management role at a terminal or MCU. It issues primitives to the GCC provider which starts and controls the communication session. The node controller itself is outside the scope of the T.120 series of Recommendations, and only where it communicates to GCC are its interfaces defined. However, correct interaction with GCC imposes some normative requirements on the node controller. + +## **6.4 Communications infrastructure** + +The communications infrastructure provides multipoint connectivity with reliable data delivery. It can accommodate multiple independent applications concurrently using the same multipoint environment. Connections between nodes can be any combination of circuit-switched telecommunications networks and packet-based LANs and data networks. The T.120 infrastructure is composed of three standardized components: Generic conference control (GCC), the multipoint communication service (MCS) and transport protocol profiles for each of the supported networks. + +### **Generic conference control** + +GCC provides a set of services for setting up and managing the multipoint conference. It provides access control and arbitration of capabilities. GCC facilities are used by applications to coordinate the use of MCS channels and tokens. GCC facilities can be used to query an MCU or multipoint terminal node to find a desired conference. Multiple applications can be running on any given node and can be dynamically launched, used and shut down during a conference. As part of the management role, peer GCC providers exchange information about the applications present and their capabilities. GCC also makes a centralized registry facility available to applications in order to identify dynamically assigned resources such as channels and tokens. + +### **Multipoint communication service** + +MCS provides a general purpose multipoint connection-oriented data service. It collects point-to-point transport connections and combines them to form a multipoint domain. Within that domain, a large number of logical channels are provided that can provide one-to-one, one-to-many and many-to-one data delivery. Nodes within an MCS domain are hierarchically organized in a tree structure. Data delivery normally follows the most efficient path to the nodes that are to receive the data, but a mechanism is provided to guarantee that data originating from different nodes is received in the same sequence at all nodes. MCS acts as a resource provider to the layers above, independent of the underlying network, providing channels and token resources on demand. Tokens are provided for applications to use for coordinating events and processes. + +### Network-specific transport protocols + +[ITU-T T.123] provides reliable point-to-point sequenced data delivery of MCS PDUs and segmentation of that data if necessary. [ITU-T T.123] specifies a protocol stack for each particular network supported. [ITU-T T.123] presents a uniform OSI Transport Service interface to the MCS layer above. + +## 6.5 Networks + +The T.120-series Recommendations suite provide for operation over the following networks: + +- ISDN – Integrated Services Digital Network as defined in the I-series Recommendations. +- CSDN – Other (switched or permanent) digital circuits. +- PSDN – Packet Switched Data Network using ITU-T Rec. X.25. +- PSTN – Public Switched Telephone Network (or compatible service). +- Use of this Recommendation on other networks such as B-ISDN and LANs is currently under study. Alternative protocol stack profiles may be defined in the future. + +The approach taken with the T.120 architecture leads to the multipoint routing information being located in MCS above the transport stacks; this is the key to the network independence that can be achieved with this Recommendation. + +The various Recommendations that comprise the T.120-series Recommendations suite are described in greater detail in clauses 7 and 8. + +# 7 T.120 infrastructure Recommendations + +The T.120 protocols are designed to operate over a wide range of networks and indeed to facilitate communication between endpoints on a mixture of networks. The differences in T.120 operation for the various networks are confined to the lowest layers as detailed in [ITU-T T.123]. + +## 7.1 Protocol stacks for audiographic and audiovisual conferencing – ITU-T Rec. T.123 + +[ITU-T T.123] defines the network-specific transport stacks for each supported network. Generally, existing link layer protocols appropriate to each network are selected and then mapped into a common interface layer, thus defining a transport profile for a given network. At Transport level the conference is seen as a group of point-to-point connected pairs (different pairs may be on different networks). The multipoint communication service (MCS), takes the transport pairs from the layer below it and maps them into a multipoint domain. See Figure 4. + +![Figure 4: Protocol stacks defined in ITU-T Rec. T.123. The diagram shows a hierarchical structure. At the top is a box labeled 'ITU-T Rec. T.125 – Multipoint communication service (MCS)'. Below it is a dashed line separating the 'Network-independent layer' from the 'Network-dependent transports' layer. Under the dashed line, there are six boxes: 'ISDN transport', 'CSDN transport', 'PSDN transport', 'PSTN transport', 'B-ISDN transport', and 'LAN transport'. The last two boxes are enclosed in dashed lines. Vertical lines connect the MCS box to each of the transport boxes. The label 'T.120(01-07)_F04' is at the bottom right.](704082cc3e11776bda29595c76411362_img.jpg) + +Figure 4 illustrates the protocol stacks defined in ITU-T Rec. T.123. The diagram is divided into two main sections by a dashed line: the 'Network-independent layer' at the top and the 'Network-dependent transports' layer at the bottom. In the Network-independent layer, there is a single box labeled 'ITU-T Rec. T.125 – Multipoint communication service (MCS)'. In the Network-dependent transports layer, there are six boxes: 'ISDN transport', 'CSDN transport', 'PSDN transport', 'PSTN transport', 'B-ISDN transport', and 'LAN transport'. The boxes for 'B-ISDN transport' and 'LAN transport' are enclosed in dashed lines. Vertical lines connect the 'ITU-T Rec. T.125' box to each of the transport boxes. The label 'T.120(01-07)\_F04' is located at the bottom right of the diagram. + +Figure 4: Protocol stacks defined in ITU-T Rec. T.123. The diagram shows a hierarchical structure. At the top is a box labeled 'ITU-T Rec. T.125 – Multipoint communication service (MCS)'. Below it is a dashed line separating the 'Network-independent layer' from the 'Network-dependent transports' layer. Under the dashed line, there are six boxes: 'ISDN transport', 'CSDN transport', 'PSDN transport', 'PSTN transport', 'B-ISDN transport', and 'LAN transport'. The last two boxes are enclosed in dashed lines. Vertical lines connect the MCS box to each of the transport boxes. The label 'T.120(01-07)\_F04' is at the bottom right. + +**Figure 4 – Protocol stacks – defined in ITU-T Rec. T.123** + +## 7.2 Multipoint communication service (MCS) – ITU-T Recs T.122 and T.125 + +The multipoint communication service (MCS) is contained in two Recommendations: [ITU-T T.122] defines the MCS service and [ITU-T T.125] the protocol which is mandatory. + +MCS is a key element in the infrastructure of this Recommendation. It takes the point-to-point transport connections provided by the layers below it and combines them to form a multipoint domain. The T.120 protocol can handle a multiplicity of domains – each effectively an independent conference or group activity. Nodes may participate in more than one domain. + +A domain with only two terminal nodes participating mirrors the traditional point-to-point communications model and is fully supported by MCS but with the potential of introducing more nodes as required. + +Each connected pair in an MCS domain is ordered, so that one node is higher than the other. The domain must rise hierarchically (without loops) to a top node. The MCS provider at the top node is assigned the Top Provider role, acting as the resource server for the domain. + +The MCS provides transport of control and data streams from one terminal to any or all others in the conference. It does not need to know anything about the content of application data streams. + +MCS introduces the concept of channels to provide data distribution within a domain; an MCS channel connects all the nodes which have expressly joined it. It is not required that a channel be joined in order to send to it. Data sent to a channel will be conveyed to all other nodes which have joined that channel. MCS supports four types of channels. + +A "static" channel exists when a domain is established. MCS reserves a block of channel identifiers for static use. Static channels may be given preassigned roles by the protocols making use of MCS services (such roles are not of concern to MCS). Annex A defines the mapping of preassigned roles to channel identifiers. Any node may join a static channel, and there is no "owner". + +A "dynamic" channel is created on request by any node or application. Dynamic channels come in three forms: "Multicast", "Private" and "Single Member". Multicast (Assigned) channels are similar to static channels in that they are open access – any terminal may join them, and there is no owner. Private channels however are owned by their creator and are joined by invitation only, thus forming a private or closed-user-group. A "Single Member" channel is normally used to provide a User Identifier, giving the owner a unique address within the domain. + +There are two specified types of data: ordinary data is sent by the shortest route to its destinations – nothing governs the order in which information arrives from different source terminals, so it can happen that presentations to users may not be identical. Uniform sequenced data, on the other hand, is routed to a common point (the top MCU in the connection hierarchy, called the "top provider") and distributed thence to all relevant terminals in the same order; clearly this may take longer than for ordinary data. + +MCS supports four data priorities; according to the priority requested in the header of data primitives coming down into MCS, they are routed into one of up to four corresponding transport connections. + +MCS provides a token management service and is able to support the use of a range of tokens. In order to provide exclusivity, and thus consistency across a domain only the Top Provider is able to execute actions on tokens. MCS supports the following token actions; grab, inhibit, give, please and release. The role allocated to tokens is assigned by the layers above MCS (and is not the concern of MCS). + +Much of the power and flexibility of MCS derives from its provision of services in a manner that is independent of the underlying network connections. This allows portability across networks and an inherent capability to interwork between terminals on different networks. + +## **7.3 Generic conference control (GCC) – ITU-T Rec. T.124** + +The generic conference control (GCC) service and protocol is defined in [ITU-T T.124]; it resides above MCS in the T.120 stack infrastructure. GCC is a mandatory component for peer-to-peer conferencing and group working environments, providing a high-level framework for management and control in support of a diverse range of terminals and MCUs. + +A GCC conference has a direct correspondence to an MCS domain. GCC provides mechanisms for the creation, control and the termination of conferences. It also makes provision for building and distributing the conference and application databases. + +MCS supports four data priorities, one of which (top priority) is reserved for exclusive use by GCC for control and management. The remaining three priorities are available for application use. + +GCC reserves a block of MCS tokens and designates them to be static and thus assigned functionality by this Recommendation (Annex A). The remaining tokens are designated dynamic and their functionality is assigned in the registry and is valid only for the duration of a conference session. + +The conference roster contains a record of the conference configuration, that includes such things as the name of the conference, the types of participating nodes (terminal, MCU or multiport terminal), and site and participant information for each node. + +When a node joins a conference it announces its presence to that conference. This causes the conference roster to be updated and distributed. + +GCC supports the enrolment in a conference of application protocols. Each GCC provider maintains a local application roster containing information and capabilities for its enrolled application protocols. The local rosters are sent to the top node of a conference where a conference application roster is compiled and then distributed. In this way all nodes learn of the additional capabilities of their peers. + +Once enrolled, application protocols entities are free to use MCS resources as described in the generic application template [ITU-T T.121]. However, if the conference enters conducted mode, permission may be required before an application protocol entity can act. + +# **8 Application protocol Recommendations** + +The T.120 series includes application protocols that provide commonly required functionality to user applications, in a way that ensures a guaranteed level of interworking across a diverse range of terminals with differing capabilities. + +## **8.1 The generic application template (GAT) – ITU-T Rec. T.121** + +[ITU-T T.121] defines a conceptual model of a T.120 application protocol. It serves as a guide to application protocol developers, ensuring a consistent approach to the development of application protocols. It also provides guidance to user application developers on how to utilize the T.120 infrastructure to best effect. + +The model consists of two functionally distinct parts: the application resource manager (ARM) and the application service element (ASE). The ARM is responsible for managing GCC and MCS resources on behalf of the ASE. + +The ARM provides generic functionality, available to all application protocols. It effectively defines a template to which specific application functionality can be added. The functionality provided by the template is required by all application protocols, both standard and non-standard. Compliance to the template is mandatory for standardized application protocols. Although not mandatory for non-standard application protocols, it is recommended, to ensure consistency and reduce the potential for unforeseen interaction between different protocols. + +The ASE provides application-protocol-specific functionality, independent of the type of channel and token resources provided to it by the ARM. See Figure 5. + +![Figure 5: Generic application template architecture diagram.](c85ded401105f62f2d6ff26b3b5eb4af_img.jpg) + +The diagram illustrates the Generic application template architecture. At the top is a box labeled 'User application'. Below it is a large box labeled 'Generic application template'. Inside this template is a box labeled 'Generic application resource manager (generic ARM)'. To the left of the template is a box labeled 'Node controller'. To the right is a dashed box labeled 'Application service element(s) (ASE)'. Below the template is a large box containing two sub-boxes: 'Generic conference control (GCC) ITU-T Rec. T.124' and 'Multipoint communication service (MCS) ITU-T Recs T.122 and T.125'. Arrows indicate the following connections: a bidirectional arrow between 'User application' and 'Generic application template'; a bidirectional arrow between 'Node controller' and 'Generic application template'; a bidirectional arrow between 'Node controller' and 'Generic conference control (GCC)'; a bidirectional arrow between 'Generic application template' and 'Generic conference control (GCC)'; a bidirectional arrow between 'Generic conference control (GCC)' and 'Multipoint communication service (MCS)'; a bidirectional arrow between 'Generic application template' and 'Multipoint communication service (MCS)'; a dashed arrow pointing from 'Application service element(s) (ASE)' to the 'Generic application resource manager (generic ARM)'; and a text label 'Provides application-specific functionality' below the ASE box. + +T.120(01-07)\_F05 + +Figure 5: Generic application template architecture diagram. + +**Figure 5 – Generic application template** + +## 8.2 Multipoint still image and annotation protocol (MSIA) – ITU-T Rec. T.126 + +[ITU-T T.126] defines the protocol to be used by a broad set of user applications that require interoperable graphical information exchange in a multi-vendor environment. It can be employed by user applications requiring simple whiteboarding, annotated image exchange and hard copy image exchange as well as for more advanced functions such as remote computer application piloting and screen sharing. The protocol manages the conference-wide synchronization of multi-plane/multi-view graphical workspaces. An extensible set of bitmap, pointer and parametric drawing primitives can be directed to these workspaces. Advanced options such as keyboard and pointing device signalling to support computer application remote piloting and screen sharing are also defined. All aspects of the protocol have provisions for in-band extensibility to allow any new or extended primitives that are not defined to be added and detected within a conference. + +## 8.3 Multipoint binary file transfer (MBFT) – ITU-T Rec. T.127 + +[ITU-T T.127] defines a protocol to support interchange of binary files within an interactive conferencing or group working environment. It does not impose any restrictions on the content of the files to be transferred. It is a versatile, lightweight protocol which provides the core functionality to allow interworking between applications requiring a basic general-purpose file transfer capability. It also has the flexibility to meet the demands of more sophisticated applications. Mechanisms are provided which facilitate both distribution and retrieval of files. + +A basic file transfer application conforming to [ITU-T T.127] may simply offer the ability to broadcast one file at a time to all applications which support the MBFT protocol. Optional advanced features defined in [ITU-T T.127] include: + +- broadcast of multiple files simultaneously; +- private distribution of files to a selected subset of the conference; +- conductor control of file distribution. + +## **8.4 T.120 extensions for audiovisual control** + +For further study + +## **8.5 Proprietary extensions to standardized protocols** + +Extensions to standardized protocol may be made by making use of the non-standard PDU or other elements that have been reserved in the relevant specifications for proprietary use. + +## **8.6 Non-standard application protocols** + +Provision of additional functionality may be made by creation of additional proprietary application protocols which use the resources of MCS and GCC. Where separate proprietary protocols are defined, it is recommended that the Generic Application Template [ITU-T T.121] be used as the model for the generic component of Application Protocol, the Application Resource Manager. Guidance on extension, modification and reuse of existing application protocols is given in [ITU-T T.121]. A non-standard application protocol entity must use GCC in a way that does not risk conflict with other application protocol entities. In particular, it shall not use static channels or static tokens and must enroll using a non-standard application protocol key. + +# **9 T.120 compliance** + +For use within a multimedia conferencing environment, this Recommendation requires: + +- compliance with the Transport Protocol stack profile [ITU-T T.123] for the selected networks; +- compliance with the Multipoint Communication Service protocol [ITU-T T.125]; +- compliance with the mandatory parts of Generic Conference Control [ITU-T T.124]; +- compliance with the mandatory parts of any standardized application protocols that have scope covering functionality supported by the user applications. + +Compliance to this Recommendation is specified in Table 1. + +Options within each item are clearly set out within the requisite Recommendation; thus, except where otherwise stated, in this table compliance means to the minimum requirement of the Recommendation. + +**Table 1 – T.120 compliance table** + +| Item
(Recommendation) | Status | Conditions | +|----------------------------------|---------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| T.121 | Conditional | Mandatory when specified by an application protocol | +| T.123 | Mandatory | Basic mode profile, according to network type | +| T.124 (GCC) | Mandatory |

Mandatory protocol elements – As specified in Table 6-1 of [ITU-T T.124], according to node type

Conditional protocol elements – Requirement dependent on the needs of application protocols to be supported at the node

In addition, a node attempting to enter an existing conference via GCC-Conference-Join request shall specify exactly the minima and maxima of the MCS domain parameter values defined in Annex B as its allowed range of negotiation

| +| T.125 (MCS) | Mandatory | The defined protocol is mandatory. The domain parameter values selected for an MCS domain shall lie within the ranges defined in Annex B. | +| T.126 (MSIA) | Conditional |

Mandatory when a node makes use of one or more of the following features:

  • • exchange of soft copy still images;
  • • exchange of hard copy still images (including FAX);
  • • shared whiteboard functionality;
  • • exchange of annotated soft copy still images.

In the above cases it must be possible to activate the standard base session for [ITU-T T.126] for the same purpose. Annex A of [ITU-T T.126] defines those parts of [ITU-T T.126] that are mandatory for each of the above functions

| +| T.127 (MBFT) | Conditional |

Mandatory for general purpose file transfer applications

It must be possible to activate the standard base session for [ITU-T T.127]

| + +# Annex A + +## T.120 channel and token allocations + +(This annex forms an integral part of this Recommendation) + +### A.1 Static channels + +| Symbolic name | MCS channel ID | Description | Recommendation | +|----------------|----------------|-----------------------------|----------------| +| GCC-CHANNEL-0 | 1 | GCC broadcast channel | T.124 | +| GCC-CHANNEL-1 | 2 | Convenor channel | T.124 | +| SI-CHANNEL-0 | 8 | MSIA communications channel | T.126 | +| MBFT-CHANNEL-0 | 9 | Control channel | T.127 | +| MBFT-CHANNEL-1 | 10 | Data channel | T.127 | +| AS-CHANNEL-0 | 11 | Application sharing channel | T.128 | +| CHAT-CHANNEL-0 | 12 | Chat data channel | T.134 | + +### A.2 Static tokens + +| Symbolic name | MCS token ID | Description | Recommendation | +|---------------|--------------|------------------------|----------------| +| GCC-TOKEN-0 | 1 | Conductors token | T.124 | +| SI-TOKEN-0 | 8 | Bit map create token | T.126 | +| SI-TOKEN-1 | 9 | Workspace create token | T.126 | +| MBFT-TOKEN-0 | 10 | File transmit token | T.127 | +| MBFT-TOKEN-1 | 11 | File receive token | T.127 | + +### A.3 Standard application protocol session identifiers + +| Application protocol Recommendation | MCS channel identifier used as session identifier | +|-------------------------------------|---------------------------------------------------| +| T.126 | SI-CHANNEL-0 | +| T.127 | MBFT-CHANNEL-0 | + +## Annex B + +## MCS domain parameters + +(This annex forms an integral part of this Recommendation) + +The MCS protocol [ITU-T T.125] states that MCS providers allocate resources and execute procedures according to the domain parameters established for any given domain. The establishment of the first MCS connection between two nodes fixes the domain parameters for all subsequent joiners. + +In order to avoid the possibility of these values being set at values inconsistent with the requirements of later nodes, this Recommendation requires that MCS domain parameter settings adhere to the specified ranges in all situations. + +In addition, a node attempting to enter an existing conference via GCC-Conference-Join request shall specify exactly the minima and maxima of the MCS domain parameter values defined in this Annex as its allowed range of negotiation. + +NOTE – It is possible for MCS domain parameters to be negotiated out-of-band prior to conference establishment. However, only in cases where it could be guaranteed that all participating nodes can conform to the agreed values, is it permissible to specify values other than those defined in this annex. This method is not recommended, and could cause subsequent connections to fail. + +- a) Maximum number of MCS channels that may be in use simultaneously. This includes channels that are joined by any user, channel IDs that have been assigned, and private channels that have been created. + +| | | +|---------------|--------| +| Minimum value | 10 | +| Maximum value | 65 535 | + +- b) Maximum number of user ids that may be assigned simultaneously. This is a sub-limit within the constraint of the preceding parameter. + +| | | +|---------------|--------| +| Minimum value | 10 | +| Maximum value | 64 535 | + +- c) Maximum number of token ids that may be grabbed or inhibited simultaneously. + +| | | +|---------------|--------| +| Minimum value | 0 | +| Maximum value | 65 535 | + +- d) Number of data transfer priorities implemented. This equals the number of transport connections in an MCS connection. An MCS user may still send and receive data with priorities outside the limit. However, such priorities may be treated the same as the lowest priority that is implemented. + +| | | +|---------------|---| +| Minimum value | 1 | +| Maximum value | 4 | + +- e) Enforced throughput. Although global flow control limits data transfer within a domain to the rate of the slowest receiver, receivers must not be allowed to run arbitrarily slowly. Otherwise, one party in a conference may obstruct all others. This parameter instructs MCS providers to enforce a minimum receiving rate at each MCS attachment and over each downward MCS connection. Violators run the risk of being involuntarily detached or disconnected, respectively. + +| | | +|---------------|------------------------------| +| Minimum value | 0 (no minimum rate enforced) | +| Maximum value | 0 (no minimum rate enforced) | + +- f) Maximum height. This constrains the height of all MCS providers, in particular the top provider. + +| | | +|---------------|-----| +| Minimum value | 2 | +| Maximum value | 100 | + +- g) Maximum size of domain MCSPDUs. Global flow control is based on buffering domain MCSPDUs within an MCS provider (but not connect MCSPDUs). For simplicity, fixed-size buffers are assumed. An MCS provider shall not generate larger MCSPDUs. This constrains the amount of information that can be packed into a single control MCSPDU and suggests where unlimited user data should be segmented in data MCSPDUs. + +| | | +|---------------|-------------| +| Minimum value | 128 octets | +| Maximum value | 4096 octets | + +- h) Protocol version. This takes one of two values defining different encodings for domain MCSPDUs. + +| | | +|---------------|------------------------------------------------------------| +| Minimum value | Version 2 (Packed Encoding Rules for all but connect PDUs) | +| Maximum value | Version 2 (Packed Encoding Rules for all but connect PDUs) | + +# Annex C + +## Lightweight profiles for the T.120 architecture + +(This annex forms an integral part of this Recommendation) + +### Overview + +This annex provides a lightweight T.120 infrastructure (referred to throughout this annex as "*T-Lite*") that suffices as a platform to run applications such as audio-video control or text telephony. The lightweight profiles for the following T.120-related protocols are defined here: + +- T.123; +- T.122/T.125; +- T.124; +- T.121. + +These profiles preserve their T.120 compliance "on the wire" when interacting with other T.120 (*T-Lite* as well as conventional) nodes. They also can be implemented with less effort than traditional T.120 enhanced multimedia terminals. An important point to consider is that T.120 services that are not included in the profiles defined here can be added back, on an as-needed basis. For example, if an implementer wishes to support conductorship within their audio-video-data product, they can simply add conductorship to the *T-Lite* profile defined here. Another example is the addition of other APEs. If an application is limited to using a single T.120 APE (say T.128), the thin T.124 implementation could be limited to support a single roster for that APE. If support for additional APEs becomes a requirement, support for additional rosters can be added to T.124. The important consideration is: what services are required by the APEs sitting on top of the T.120 infrastructure. If a service is not required it need not be implemented (unless specified in this profile). + +It is important for a *T-Lite* developer to know, in advance, which specific APEs are to be supported by the stack. This is important because the Application Protocol Key (which is a unique identifier for the APE) is used to filter unsupported Application Rosters received by the lightweight node (see C.3.5). + +This annex also addresses the issues that may arise when two (or more) T.120 implementations with different or identical feature sets attempt to communicate. This includes discussions on how to treat incoming T.120 PDUs not included in this thin profile. It also addresses backward compatibility issues. The services included in the profiles defined below are the minimal set required to maintain T.120 compliance, while also providing a reasonable subset of functionality. These profiles can be thought of as the least-common-denominator feature set that is necessary to maintain interoperability with all standard compliant flavours of T.120 nodes. + +Figure C.1 gives an overview of the components of the T.120 architecture that are retained for the *T-Lite* profile (within the framework of a typical AVD product). Implementing the supported functionality in each of the components of the *T-Lite* profile is considerably simplified to that of a traditional T.120 node because a terminal using this thin infrastructure may be restricted in its operation in the following ways: + +- 1) supports only a single connection to another node; +- 2) participation in a single conference at a time only (i.e., one MCS connection, one MCS domain, a single transport protocol hierarchy active at a time, one GCC conference, etc.); +- 3) use of only a single application protocol entity; and + +- 4) Top Provider operation restricted to point-to-point conferences between two nodes which then requires reduced Top Provider functionality. + +In some cases, it may be known in advance that a *T-Lite* implementation will only be used as a leaf-node and will never be responsible for providing Top Provider services. In these cases, developers may decide to not include Top Provider functionality in their implementation. This is an acceptable approach. + +![Figure C.1: T-Lite within a typical AVD framework. The diagram shows the architecture of a T-Lite implementation within an AVD framework. At the top is the 'Audiovisual application(s)' block. Below it are 'Real-time audio device' and 'Real-time video device' blocks, which connect to the application via bidirectional arrows. To the right is the 'Node controller' block, also connected to the application. Below the real-time devices are 'Audio stream(s)' and 'Video stream(s)' paths leading to the 'Network multiplex' block at the bottom. The 'Node controller' connects to 'Network-specific mappings ITU-T Rec. T.131 (NSM) (Note)' and 'Audio-visual control ITU-T Rec. T.132 (AVC) (Note)'. The 'Audio-visual control' block connects to a 'T-Lite' block containing 'Generic conference control ITU-T Rec. T.124 Lite profile (GCC)' and 'Multipoint communication service (MCS) ITU-T Recs T.122 and T.125 Lite profile'. The 'T-Lite' block connects to 'Network transport protocols (ITU-T Rec. T.123)', which in turn connects to the 'Network multiplex' via a 'Data' path. A 'Network-specific control entity' block connects to the 'Network multiplex' via a 'Control' path. The 'Network multiplex' block is at the bottom. A note at the bottom left states 'NOTE – Recommendations under development.' and a reference 'T.120(01-07)_F-C.01' is at the bottom right.](366a77fdefb0097b3289b4a011911390_img.jpg) + +Figure C.1: T-Lite within a typical AVD framework. The diagram shows the architecture of a T-Lite implementation within an AVD framework. At the top is the 'Audiovisual application(s)' block. Below it are 'Real-time audio device' and 'Real-time video device' blocks, which connect to the application via bidirectional arrows. To the right is the 'Node controller' block, also connected to the application. Below the real-time devices are 'Audio stream(s)' and 'Video stream(s)' paths leading to the 'Network multiplex' block at the bottom. The 'Node controller' connects to 'Network-specific mappings ITU-T Rec. T.131 (NSM) (Note)' and 'Audio-visual control ITU-T Rec. T.132 (AVC) (Note)'. The 'Audio-visual control' block connects to a 'T-Lite' block containing 'Generic conference control ITU-T Rec. T.124 Lite profile (GCC)' and 'Multipoint communication service (MCS) ITU-T Recs T.122 and T.125 Lite profile'. The 'T-Lite' block connects to 'Network transport protocols (ITU-T Rec. T.123)', which in turn connects to the 'Network multiplex' via a 'Data' path. A 'Network-specific control entity' block connects to the 'Network multiplex' via a 'Control' path. The 'Network multiplex' block is at the bottom. A note at the bottom left states 'NOTE – Recommendations under development.' and a reference 'T.120(01-07)\_F-C.01' is at the bottom right. + +**Figure C.1 – T-Lite within a typical AVD framework** + +### C.1 *Lite* T.123 profile + +This clause only addresses the fact that an implementer is free to adjust the Q.922 protocol parameters suggested by clause 10 of [ITU-T 123] to meet the resource requirements of a particular implementation. For example, when the terminal implementer knows *a priori* that the application(s) to be used are control oriented (e.g., T.123), as compared to data transfer intensive application(s) (e.g., T.128), the Q.922 parameters can be negotiated to reduced values. + +In particular, traditional narrow-band audiovisual terminals that only implement T.120 services to host T.123 can take advantage of this knowledge and reduce the Q.922 protocol parameters. + +### C.2 *Lite* T.122/T.125 profile + +This clause outlines the service primitives required from [ITU-T T.122] to realize the above *T-Lite* scenario. In essence, MCS functionality can be reduced to domain management services, services to handle static and assigned MCS channels, and data transmission. + +#### C.2.1 Required primitives and PDUs + +In the following table, taken from [ITU-T T.125], all service primitives to be provided by a *T-Lite* node are shaded in gray. The legend below gives a description of each possible action that can be associated with all the possible MCS PDUs. These actions are listed in the right-most column of Table C.1: + +- R (Receive) – Implies that the PDU should be received and processed as defined by [ITU-T T.125]. +- T (Transmit) – Implies that the PDU should be transmitted as defined by [ITU-T T.125]. +- R-NA (Receive – Not Applicable) – Implies that the PDU should never be received. This is for one of three reasons: domain merge is not supported; no request was sent (so the confirm is invalid); or the neighbouring provider cannot own the resource to which the PDU refers. Reception of a PDU of this type is the equivalent of an assertion failure. +- T-NA (Transmit – Not Applicable) – Implies that since the primitive is not supported, this PDU will never be sent. +- R-D (Receive – Default) – Implies that when this PDU is received, the node should follow some default behaviour to insure interoperability. +- T-D (Transmit – Default) – Implies that this PDU should be transmitted based on some default behaviour. +- R-I (Receive – Ignore) – Implies that this PDU can be ignored on reception. Reception of a PDU of this type is NOT an assertion failure. + +**Table C.1 – MCS primitives and PDUs** + +| Functional unit | Primitives | Associated MCSPDUs | Required actions | +|-------------------|------------------------------------|-----------------------------|------------------| +| Domain management | MCS-CONNECT-PROVIDER request | ConnectInitial | T | +| | MCS-CONNECT-PROVIDER indication | ConnectInitial | R | +| | MCS-CONNECT-PROVIDER response | ConnectResponse | T | +| | MCS-CONNECT-PROVIDER confirm | ConnectResponse | R | +| | | ConnectAdditional | T/R | +| | | ConnectResult | T/R | +| | | PlumbDomainIndication | T/R | +| | | ErectDomainRequest | T/R | +| | | MergeChannelsRequest | T-NA/R-NA | +| | | MergeChannelsConfirm | T-NA/R-NA | +| | | PurgeChannelsIndication | T-NA/R-NA | +| | | MergeTokensRequest | T-NA/R-NA | +| | | MergeTokensConfirm | T-NA/R-NA | +| | | PurgeTokensIndication | T-NA/R-NA | +| | MCS-DISCONNECT-PROVIDER request | DisconnectProviderUltimatum | T | +| | MCS-DISCONNECT-PROVIDER indication | DisconnectProviderUltimatum | R | +| | | RejectUltimatum | T/R | +| | MCS-ATTACH-USER request | AttachUserRequest | T/R | +| | MCS-ATTACH-USER confirm | AttachUserConfirm | T/R | +| | MCS-DETACH-USER request | DetachUserRequest | T/R | +| | MCS-DETACH-USER indication | DetachUserIndication | T/R | +| | | MergeChannelsConfirm | T-NA/R-NA | +| | | PurgeChannelsIndication | T-NA/R-NA | +| | | MergeTokensConfirm | T-NA/R-NA | +| | | PurgeTokensIndication | T-NA/R-NA | + +| Functional unit | Primitives | Associated MCSPDUs | Required actions | +|--------------------|-------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------| +| Channel management | MCS-CHANNEL-JOIN request
MCS-CHANNEL-JOIN confirm | ChannelJoinRequest
ChannelJoinConfirm | T/R
T/R | +| | MCS-CHANNEL-LEAVE request
MCS-CHANNEL-LEAVE indication | ChannelLeaveRequest
MergeChannelsConfirm
PurgeChannelsIndication | T/R
T-NA/R-NA
T-NA/R-NA | +| | MCS-CHANNEL-CONVENE request
MCS-CHANNEL-CONVENE confirm | ChannelConveneRequest
ChannelConveneConfirm | T-NA/R-D
T-D/R-NA | +| | MCS-CHANNEL-DISBAND request
MCS-CHANNEL-DISBAND indication | ChannelDisbandRequest
MergeChannelsConfirm
PurgeChannelsIndication | T-NA/R-NA
T-NA/R-NA
T-NA/R-NA | +| | MCS-CHANNEL-ADMIT request
MCS-CHANNEL-ADMIT indication | ChannelAdmitRequest
ChannelAdmitIndication | T-NA/R-NA
T-NA/R-I | +| | MCS-CHANNEL-EXPEL request
MCS-CHANNEL-EXPEL indication | ChannelExpelRequest
ChannelExpelIndication
ChannelDisbandIndication
MergeChannelsConfirm
PurgeChannelsIndication | T-NA/R-NA
T-NA/R-I
T-NA/R-I
T-NA/R-NA
T-NA/R-NA | +| | | | | +| Data transfer | MCS-SEND-DATA request
MCS-SEND-DATA indication | SendDataRequest
SendDataIndication | T/R
T/R | +| | MCS-UNIFORM-SEND-DATA request
MCS-UNIFORM-SEND-DATA indication | UniformSendDataRequest
UniformSendDataIndication | T/R
T/R | +| | | | | +| Token management | MCS-TOKEN-GRAB request
MCS-TOKEN-GRAB confirm | TokenGrabRequest
TokenGrabConfirm | T-NA/R-D
T-D/R-NA | +| | MCS-TOKEN-INHIBIT request
MCS-TOKEN-INHIBIT confirm | TokenInhibitRequest
TokenInhibitConfirm | T-NA/R-D
T-D/R-NA | +| | MCS-TOKEN-GIVE request
MCS-TOKEN-GIVE indication | TokenGiveRequest
TokenGiveIndication | T-NA/R-NA
T-NA/R-D | + +| Functional unit | Primitives | Associated MCSPDUs | Required actions | +|-----------------|-----------------------------|-----------------------|------------------| +| | MCS-TOKEN-GIVE response | TokenGiveResponse | T-D/R-NA | +| | MCS-TOKEN-GIVE confirm | TokenGiveConfirm | T-NA/R-NA | +| | MCS-TOKEN-PLEASE request | TokenPleaseRequest | T-NA/R-I | +| | MCS-TOKEN-PLEASE indication | TokenPleaseIndication | T-NA/R-NA | +| | MCS-TOKEN-RELEASE request | TokenReleaseRequest | T-NA/R-NA | +| | MCS-TOKEN-RELEASE confirm | TokenReleaseConfirm | T-NA/R-NA | +| | MCS-TOKEN-TEST request | TokenTestRequest | T-NA/R-D | +| | MCS-TOKEN-TEST confirm | TokenTestConfirm | T-D/R-NA | +| | | | | +| | | | | + +#### C.2.2 Handling unsupported PDUs and primitives + +This clause discusses what to do with PDUs that are not simply handled normally (T/R). These PDUs fall into one of the following three categories: + +- The PDU is simply ignored on reception. +- The PDU is not applicable under this profile. +- The PDU has a default behaviour associated with it. + +PDUs that are ignored require no default behaviour when received. A PDU of this type may be received at any time and must at least be decoded by the receiving node before it is discarded (to ensure the PDU type). + +If a PDU is listed as NA or not applicable, it means that the PDU should never be sent or received (depending on the PDU type) from a node supporting this profile. The reception of a PDU that is NA should probably be flagged as an error or assertion because PDUs of this type should never be received. This is an indication that the remote node is exhibiting non-standard behaviour. + +The third class of PDUs requires some default behaviour when received or sent. Typically, it is a rejection to a message or service that is not supported. + +Table C.2 below is a definitive list of all the PDUs that require default behaviour (along with a description of that behaviour). Note that reception of any PDU that initiates some predefined default behaviour should require no action at the service layer interface. + +**Table C.2 – Table describing PDUs with default behaviour** + +| PDUs requiring default behaviour | Associated default behaviour | +|-----------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ChannelConveneRequest – Rx | If the receiving node is the Top Provider, the reception of a ChannelConveneRequest should result in the transmission of the ChannelConveneConfirm described next. | +| ChannelConveneConfirm – Tx | On reception of a ChannelConveneRequest, a ChannelConveneConfirm should be generated which includes the following: the initiator ID from the request, and a result of "too many channels". | +| TokenGrabRequest – Rx | If the receiving node is the Top Provider, the reception of a TokenGrabRequest should result in the transmission of the TokenGrabConfirm described next. | +| TokenGrabConfirm – Tx | On reception of a TokenGrabRequest, a TokenGrabConfirm should be generated which includes the following: the initiator ID and token ID from the request, a result of "too many tokens", and a token status of "not in use". | +| TokenInhibitRequest – Rx | If the receiving node is the Top Provider, the reception of a TokenInhibitRequest should result in the transmission of the TokenInhibitConfirm described next. | +| TokenInhibitConfirm – Tx | On reception of a TokenInhibitRequest, a TokenInhibitConfirm should be generated which includes the following: the initiator ID and token ID from the request, a result of "too many tokens", and a token status of "not in use". | +| TokenGiveIndication – Rx | If the receiving node is a leaf node, then the reception of a TokenGiveIndication should result in the transmission of the TokenGiveResponse described next. | + +**Table C.2 – Table describing PDUs with default behaviour** + +| PDUs requiring default behaviour | Associated default behaviour | +|-----------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| TokenGiveResponse – Tx | On reception of a TokenGiveIndication, a TokenGiveResponse should be generated which includes the following: the recipient ID and token ID from the indication, and a result of "user rejected". | +| TokenTestRequest – Rx | If the receiving node is the Top Provider, the reception of a TokenTestRequest should result in the transmission of the TokenTestConfirm described next. | +| TokenTestConfirm – Tx | On reception of a TokenTestRequest, a TokenTestConfirm should be generated which includes the following: the initiator ID and token ID from the request, and a token status of "not in use". | + +#### **C.2.3 Handling supported PDUs and primitives** + +All T.125 PDUs that are supported by the *T-Lite* profile should be handled as specified by [ITU-T T.125]. + +When a *T-Lite* node is required to act as Top Provider, it should establish the Domain Parameters to indicate that the maximum number of tokens is zero (0). This reflects the fact that all token-related requests will be denied. + +#### **C.2.4 Negotiating Top-Provider responsibilities** + +A *T-Lite* node may be required to act as the Top MCS Provider. The connection setup for a *T-Lite* node should attempt to hand off Top Provider responsibilities whenever possible (the only exception to this case is when two *T-Lite* nodes are attempting to connect). This ensures the lowest probability that a thin Top MCS Provider would receive an MCSPDU other than those indicated above. The hand-off procedure will be handled by the GCC Conference Query and is discussed below. + +### **C.3 Lite T.124 profile** + +This clause describes the service primitives required from a T.124 provider for a *T-Lite* node. For this portion of the *T-Lite* profile, only a subset of the GCC services are needed. These include conference establishment and termination, support for the conference roster, and support for a single application roster (which does not reduce the number of services but simplifies internal management). Neither the application registry nor the conference conductorship services are needed. Also, no miscellaneous functions are required other than the sending of text messages. + +#### **C.3.1 Required primitives and PDUs** + +In the following table (Table C.3) taken from [ITU-T T.124], all service primitives to be provided by a *T-Lite* node are shaded in gray. For each primitive, it is noted whether or not it applies only to a Top Provider node (TP stands for Top Provider). For nodes that are guaranteed to never be a Top Provider node, it is not necessary to support the primitives specified as TP. *T-Lite* nodes that can act as a Top Provider should support all the gray-shaded primitives. + +The legend below gives a description of each possible action that can be associated with all the possible GCC Primitives and PDUs. These actions are listed in the right-most column of Table C.3: + +- R (Receive) – Implies that the PDU should be received and processed as defined by [ITU-T T.124]. +- T (Transmit) – Implies that the PDU should be transmitted as defined by [ITU-T T.124]. +- R-NA (Receive – Not Applicable) – Implies that since the request portion of this exchange will never be sent, a response should never occur (and can be ignored). Reception of a PDU of this type is the equivalent of an assertion failure. +- T-NA (Transmit – Not Applicable) – Implies that since the primitive is not supported, this PDU will never be sent. +- R-D (Receive – Default) – Implies that when this PDU is received, the node should follow some default behaviour to insure interoperability. +- T-D (Transmit – Default) – Implies that this PDU should be transmitted based on some default behaviour. +- R-I (Receive – Ignore) – Implies that this PDU can be ignored on reception. Reception of a PDU of this type is NOT an assertion failure. + +**Table C.3 – GCC primitives and PDUs** + +| Functional unit | Primitives | TP | Associated PDUs | Actions | +|------------------------------------------|----------------------------------|----|----------------------------------------------|-----------------| +| Conference establishment and termination | GCC-CONFERENCE-CREATE request | | ConferenceCreateRequest | T | +| | GCC-CONFERENCE-CREATE indication | TP | ConferenceCreateRequest | R | +| | GCC-CONFERENCE-CREATE response | TP | ConferenceCreateResponse | T | +| | GCC-CONFERENCE-CREATE confirm | | ConferenceCreateResponse
UserIDIndication | R
T, R | +| | GCC-CONFERENCE-QUERY request | | ConferenceQueryRequest | T | +| | GCC-CONFERENCE-QUERY indication | | ConferenceQueryRequest | R | +| | GCC-CONFERENCE-QUERY response | | ConferenceQueryResponse | T | +| | GCC-CONFERENCE-QUERY confirm | | ConferenceQueryResponse | R | +| | GCC-CONFERENCE-JOIN request | | ConferenceJoinRequest | T | +| | GCC-CONFERENCE-JOIN indication | TP | ConferenceJoinRequest | R | +| | GCC-CONFERENCE-JOIN response | TP | ConferenceJoinResponse | T | +| | GCC-CONFERENCE-JOIN confirm | | ConferenceJoinResponse
UserIDIndication | R
T, R | +| | GCC-CONFERENCE-INVITE request | | ConferenceInviteRequest | T-NA | +| | GCC-CONFERENCE-INVITE indication | | ConferenceInviteRequest | R | +| | GCC-CONFERENCE-INVITE response | | ConferenceInviteResponse | T | +| | GCC-CONFERENCE-INVITE confirm | | ConferenceInviteResponse
UserIDIndication | R-NA
T, R-NA | + +**Table C.3 – GCC primitives and PDUs** + +| Functional unit | Primitives | TP | Associated PDUs | Actions | +|-----------------|---------------------------------------|----|-------------------------------|-----------| +| | GCC-CONFERENCE-ADD request | | ConferenceAddRequest | T-NA | +| | GCC-CONFERENCE-ADD indication | | ConferenceAddRequest | R-D | +| | GCC-CONFERENCE-ADD response | | ConferenceAddResponse | T-D | +| | GCC-CONFERENCE-ADD confirm | | ConferenceAddResponse | R-NA | +| | GCC-CONFERENCE-LOCK request | | ConferenceLockRequest | T-NA | +| | GCC-CONFERENCE-LOCK indication | | ConferenceLockRequest | R-D | +| | GCC-CONFERENCE-LOCK response | | ConferenceLockResponse | T-D | +| | GCC-CONFERENCE-LOCK confirm | | ConferenceLockResponse | R-NA | +| | GCC-CONFERENCE-UNLOCK request | | ConferenceUnlockRequest | T-NA | +| | GCC-CONFERENCE-UNLOCK indication | | ConferenceUnlockRequest | R-D | +| | GCC-CONFERENCE-UNLOCK response | | ConferenceUnlockResponse | T-D | +| | GCC-CONFERENCE-UNLOCK confirm | | ConferenceUnlockResponse | R-NA | +| | GCC-CONFERENCE-LOCK-REPORT indication | | ConferenceLockIndication | T-NA, R-I | +| | | | ConferenceUnlockIndication | T-NA, R-I | +| | GCC-CONFERENCE-DISCONNECT request | | – | – | +| | GCC-CONFERENCE-DISCONNECT indication | | – | – | +| | GCC-CONFERENCE-DISCONNECT confirm | | – | – | +| | GCC-CONFERENCE-TERMINATE request | | ConferenceTerminateRequest | T-NA | +| | | | ConferenceTerminateRequest | R | +| | GCC-CONFERENCE-TERMINATE indication | | ConferenceTerminateIndication | T | +| | | | ConferenceTerminateIndication | R | +| | GCC-CONFERENCE-TERMINATE confirm | | ConferenceTerminateResponse | T | +| | | | ConferenceTerminateResponse | R-NA | +| | GCC-CONFERENCE-EJECT-USER request | | ConferenceEjectUserRequest | T-NA | +| | | | ConferenceEjectUserRequest | R-D | + +**Table C.3 – GCC primitives and PDUs** + +| Functional unit | Primitives | TP | Associated PDUs | Actions | +|--------------------|-------------------------------------------------|----|-------------------------------|---------| +| | GCC-CONFERENCE-EJECT-USER indication | | ConferenceEjectUserIndication | T-NA | +| | | | ConferenceEjectUserIndication | R | +| | GCC-CONFERENCE-EJECT-USER confirm | | ConferenceEjectUserResponse | T-D | +| | | | ConferenceEjectUserResponse | R-NA | +| | GCC-CONFERENCE-TRANSFER request | | ConferenceTransferRequest | T-NA | +| | | | ConferenceTransferRequest | R-D | +| | GCC-CONFERENCE-TRANSFER indication | | ConferenceTransferIndication | T-NA | +| | | | ConferenceTransferIndication | R-I | +| | GCC-CONFERENCE-TRANSFER confirm | | ConferenceTransferResponse | T-D | +| | | | ConferenceTransferResponse | R-NA | +| Conference roster | GCC-CONFERENCE-ANNOUNCE-PRESENCE request | | RosterUpdateIndication | T, R | +| | | | RosterRefreshRequest | T, R | +| | GCC-CONFERENCE-ANNOUNCE-PRESENCE confirm | | – | – | +| | GCC-CONFERENCE-ROSTER-REPORT indication | | RosterUpdateIndication | T, R | +| | GCC-CONFERENCE-ROSTER-INQUIRE request | | – | – | +| | GCC-CONFERENCE-ROSTER-INQUIRE confirm | | – | – | +| Application roster | GCC-APPLICATION-PERMISSION-TO-ENROLL indication | | – | – | +| | GCC-APPLICATION-ENROLL request | | RosterUpdateIndication | T, R | +| | | | RosterRefreshRequest | T, R | +| | GCC-APPLICATION-ENROLL confirm | | – | – | +| | GCC-APPLICATION-ROSTER-REPORT indication | | RosterUpdateIndication | T, R | +| | GCC-APPLICATION-ROSTER-INQUIRE request | | – | – | +| | GCC-APPLICATION-ROSTER-INQUIRE confirm | | – | – | +| | GCC-APPLICATION-INVOKE request | | ApplicationInvokeIndication | T-NA | + +**Table C.3 – GCC primitives and PDUs** + +| Functional unit | Primitives | TP | Associated PDUs | Actions | +|----------------------|---------------------------------------------------------------------|----|------------------------------------------------------------------|-------------| +| | GCC-APPLICATION-INVOKE indication
GCC-APPLICATION-INVOKE confirm | | ApplicationInvokeIndication
– | R-I
– | +| Application registry | GCC-REGISTRY-REGISTER-CHANNEL request | | RegistryRegisterChannelRequest
RegistryRegisterChannelRequest | T-NA
R-D | +| | GCC-REGISTRY-REGISTER-CHANNEL confirm | | RegistryResponse
RegistryResponse | T-D
R-NA | +| | GCC-REGISTRY-ASSIGN-TOKEN request | | RegistryAssignTokenRequest
RegistryAssignTokenRequest | T-NA
R-D | +| | GCC-REGISTRY-ASSIGN-TOKEN confirm | | RegistryResponse
RegistryResponse | T-D
R-NA | +| | GCC-REGISTRY-SET-PARAMETER request | | RegistrySetParameterRequest
RegistrySetParameterRequest | T-NA
R-D | +| | GCC-REGISTRY-SET-PARAMETER confirm | | RegistryResponse
RegistryResponse | T-D
R-NA | +| | GCC-REGISTRY-RETRIEVE-ENTRY request | | RegistryRetrieveEntryRequest
RegistryRetrieveEntryRequest | T-NA
R-D | +| | GCC-REGISTRY-RETRIEVE-ENTRY confirm | | RegistryResponse
RegistryResponse | T-D
R-NA | +| | GCC-REGISTRY-DELETE-ENTRY request | | RegistryDeleteEntryRequest
RegistryDeleteEntryRequest | T-NA
R-D | +| | GCC-REGISTRY-DELETE-ENTRY confirm | | RegistryResponse
RegistryResponse | T-D
R-NA | +| | GCC-REGISTRY-MONITOR request | | RegistryMonitorEntryRequest
RegistryMonitorEntryRequest | T-NA
R-D | + +**Table C.3 – GCC primitives and PDUs** + +| Functional unit | Primitives | TP | Associated PDUs | Actions | +|-----------------------------|--------------------------------------|----|--------------------------------|---------| +| | GCC-REGISTRY-MONITOR indication | | RegistryMonitorEntryIndication | T-NA | +| | | | RegistryMonitorEntryIndication | R-I | +| | GCC-REGISTRY-MONITOR confirm | | RegistryResponse | T-D | +| | | | RegistryResponse | R-NA | +| | GCC-REGISTRY-ALLOCATE-HANDLE request | | RegistryAllocateHandleRequest | T-NA | +| | | | RegistryAllocateHandleRequest | R-D | +| Conference
conductorship | GCC-REGISTRY-ALLOCATE-HANDLE confirm | | RegistryAllocateHandleResponse | T-D | +| | | | RegistryAllocateHandleResponse | R-NA | +| | GCC-CONDUCTOR-ASSIGN request | | – | – | +| | GCC-CONDUCTOR-ASSIGN indication | | ConductorAssignIndication | T-NA | +| | | | ConductorAssignIndication | R-I | +| | GCC-CONDUCTOR-ASSIGN confirm | | – | – | +| | GCC-CONDUCTOR-RELEASE request | | ConductorReleaseIndication | T-NA | +| | | | ConductorReleaseIndication | R-I | +| | GCC-CONDUCTOR-RELEASE indication | | ConductorReleaseIndication | T-NA | +| | | | ConductorReleaseIndication | R-I | +| | GCC-CONDUCTOR-RELEASE confirm | | – | – | +| | GCC-CONDUCTOR-PLEASE request | | – | – | +| | GCC-CONDUCTOR-PLEASE indication | | – | – | +| | GCC-CONDUCTOR-PLEASE response | | – | – | +| | GCC-CONDUCTOR-PLEASE confirm | | – | – | +| | GCC-CONDUCTOR-GIVE request | | – | – | +| | GCC-CONDUCTOR-GIVE indication | | – | – | +| | GCC-CONDUCTOR-GIVE response | | ConductorAssignIndication | T-NA | + +**Table C.3 – GCC primitives and PDUs** + +| Functional unit | Primitives | TP | Associated PDUs | Actions | +|-------------------------|-------------------------------------------|----|------------------------------------|---------| +| | GCC-CONDUCTOR-GIVE confirm | | – | – | +| | GCC-CONDUCTOR-INQUIRE request | | – | – | +| | GCC-CONDUCTOR-INQUIRE confirm | | – | – | +| | GCC-CONDUCTOR-PERMISSION-ASK request | | ConductorPermissionAskIndication | T-NA | +| | GCC-CONDUCTOR-PERMISSION-ASK indication | | ConductorPermissionAskIndication | R-I | +| | GCC-CONDUCTOR-PERMISSION-ASK confirm | | – | – | +| | GCC-CONDUCTOR-PERMISSION-GRANT request | | ConductorPermissionGrantIndication | T-NA | +| | GCC-CONDUCTOR-PERMISSION-GRANT indication | | ConductorPermissionGrantIndication | R-I | +| | GCC-CONDUCTOR-PERMISSION-GRANT confirm | | – | – | +| | GCC-CONFERENCE-TIME-REMAINING request | | ConferenceTimeRemainingIndication | T-NA | +| | GCC-CONFERENCE-TIME-REMAINING indication | | ConferenceTimeRemainingIndication | R-I | +| | GCC-CONFERENCE-TIME-REMAINING confirm | | – | – | +| Miscellaneous functions | GCC-CONFERENCE-TIME-INQUIRE request | | ConferenceTimeInquireIndication | T-NA | +| | GCC-CONFERENCE-TIME-INQUIRE indication | | ConferenceTimeInquireIndication | R-I | +| | GCC-CONFERENCE-TIME-INQUIRE confirm | | – | – | +| | GCC-CONFERENCE-EXTEND request | | ConferenceTimeExtendIndication | T-NA | +| | GCC-CONFERENCE-EXTEND indication | | ConferenceTimeExtendIndication | R-I | +| | GCC-CONFERENCE-EXTEND confirm | | – | – | +| | GCC-CONFERENCE-ASSISTANCE request | | ConferenceAssistanceIndication | T-NA | +| | GCC-CONFERENCE-ASSISTANCE indication | | ConferenceAssistanceIndication | R-I | +| | GCC-CONFERENCE-ASSISTANCE confirm | | – | – | + +**Table C.3 – GCC primitives and PDUs** + +| Functional unit | Primitives | TP | Associated PDUs | Actions | +|--------------------------------------------------------|-----------------------------|----|-----------------------|---------| +| | GCC-TEXT-MESSAGE request | O | TextMessageIndication | T | +| | GCC-TEXT-MESSAGE indication | O | TextMessageIndication | R | +| | GCC-TEXT-MESSAGE confirm | O | – | – | +| | – | – | FunctionNotSupported | T, R | +| M Mandatory
C Conditionally Mandatory
O Optional | | | | | + +#### C.3.2 Handling unsupported PDUs and primitives + +This clause discusses what to do with PDUs that are not simply handled normally (T/R). These PDUs fall into one of the following three categories: + +- The PDU is simply ignored on reception. +- The PDU is not applicable under this profile. +- The PDU has a default behaviour associated with it. + +PDUs that are ignored require no default behaviour when received. A PDU of this type may be received at any time and must at least be decoded by the receiving node before it is discarded (to ensure the PDU type). + +If a PDU is listed as NA or not applicable, it means that the PDU should never be sent or received (depending on the PDU type) from a node supporting this profile. The reception of a PDU that is NA should probably be flagged as an error or assertion because PDUs of this type are only received due to an associated request that is NOT supported by this profile. Therefore, if a not-applicable PDU is received, it means that either the receiving node initiated a request that it should not have or another node in the conference is exhibiting non-standard behaviour. + +The third class of PDU requires some default behaviour when received or sent. Typically, it is a rejection to a message or service that is not supported. In many cases, it will appear to the requesting node that it is not a valid requester. This can often be attributed to lack of a particular privilege. + +Table C.4 below is a definitive list of all the PDUs of this type along with their associated default behaviour. Note that reception of any PDU that initiates some predefined default behaviour should require no action at the service layer interface. + +**Table C.4 – Table describing PDUs with default behaviour** + +| PDUs requiring default behaviour | Associated default behaviour | +|-----------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ConferenceAddRequest – Rx | On reception of an add-request, the add-response described below should be generated. | +| ConferenceAddResponse – Tx | On reception of an add-request, an add-response should be generated which includes the following: the tag sent in the add request, a result of connectionUnsuccessful and no User Data. | +| ConferenceLockRequest – Rx | On reception of a lock-request, the lock-response described below should be generated. | +| ConferenceLockResponse – Tx | On reception of a lock-request, a lock-response should be generated which includes the following: a result of invalidRequester. | +| ConferenceUnlockRequest – Rx | On reception of an unlock-request, the unlock-response described below should be generated. | +| ConferenceUnlockResponse – Tx | On reception of an unlock-request, an unlock-response should be generated which includes the following: a result of invalidRequester. | +| ConferenceEjectUserRequest – Rx | On reception of an eject-user-request, the eject-user-response described below should be generated. | +| ConferenceEjectUserResponse – Tx | On reception of an eject-user-request, an eject-user-response should be generated which includes the following: the nodeToEject UserID included in the request and a result of invalidRequester. | + +**Table C.4 – Table describing PDUs with default behaviour** + +| PDUs requiring default behaviour | Associated default behaviour | +|-----------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ConferenceTransferRequest – Rx | On reception of a transfer-request, the transfer-response described below should be generated. | +| ConferenceTransferResponse – Tx | On reception of a transfer-request, a transfer-response should be generated which includes the following: the conference name and modifier included in the request, the transferring node list included in the request and a result of invalidRequester. | +| RegistryRegisterChannelRequest – Rx | On reception of a register-channel-request, the registry-response described below should be generated. | +| RegistryResponse – Tx | On reception of a register-channel-request, a registry-response should be generated which includes the following: the entityID of the requesting node, the primitiveType set to registerChannel, the registryKey set to the key included in the request, the registryItem set to vacant, the registry entry owner set to notOwned, no modification-rights and a result of registryFull. | +| RegistryAssignTokenRequest – Rx | On reception of an assign-token-request, the registry-response described below should be generated. | +| RegistryResponse – Tx | On reception of an assign-token-request, a registry-response should be generated which includes the following: the entityID of the requesting node, the primitiveType set to assignToken, the registryKey set to the key included in the request, the registryItem set to vacant, the registry entry owner set to notOwned, no modification-rights and a result of registryFull. | +| RegistrySetParameterRequest – Rx | On reception of a set-parameter-request, the registry-response described below should be generated. | +| RegistryResponse – Tx | On reception of a set-parameter-request, a registry-response should be generated which includes the following: the entityID of the requesting node, the primitiveType set to setParameter, the registryKey set to the key included in the request, the registryItem set to vacant, the registry entry owner set to notOwned, no modification-rights and a result of registryFull. | +| RegistryRetrieveEntryRequest – Rx | On reception of a retrieve-entry-request, the registry-response described below should be generated. | +| RegistryResponse – Tx | On reception of a retrieve-entry-request, a registry-response should be generated which includes the following: the entityID of the requesting node, the primitiveType set to retrieveEntry, the registryKey set to the key included in the request, the registryItem set to vacant, the registry entry owner set to notOwned, no modification-rights and a result of notFound. | +| RegistryDeleteEntryRequest – Rx | On reception of a delete-entry-request, the registry-response described below should be generated. | +| RegistryResponse – Tx | On reception of a delete-entry-request, a registry-response should be generated which includes the following: the entityID of the requesting node, the primitiveType set to deleteEntry, the registryKey set to the key included in the request, the registryItem set to vacant, the registry entry owner set to notOwned, no modification-rights and a result of notFound. | + +**Table C.4 – Table describing PDUs with default behaviour** + +| PDUs requiring default behaviour | Associated default behaviour | +|-----------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| RegistryMonitorEntryRequest – Rx | On reception of a monitor-entry-request, the registry-response described below should be generated. | +| RegistryResponse – Tx | On reception of a monitor-entry-request, a registry-response should be generated which includes the following: the entityID of the requesting node, the primitiveType set to monitorEntry, the registryKey set to the key included in the request, the registryItem set to vacant, the registry entry owner set to notOwned, no modification-rights and a result of notFound. | +| RegistryAllocateHandleRequest – Rx | On reception of an allocate-handle-request, the allocate-handle-response described below should be generated. | +| RegistryAllocateHandleResponse – Tx | On reception of an allocate-handle-request, an allocate-handle-response should be generated which includes the following: the entityID of the requesting node, the numberOfHandle set to the number of handles specified in the request, the firstHandle set to zero, and a result of noHandlesAvailable. | + +#### C.3.3 Handling supported PDUs and primitives + +All T.124 PDUs that are supported by the *T-Lite* profile should be handled as specified by [ITU-T T.124]. However, there are a number of parameters that shall be set to a "fixed" or static value in these supported PDUs when implementing the thin T.124 portion of the *T-Lite* profile. These are listed in Table C.5. + +**Table C.5 – Fixed parameter values for transmitted PDUs** + +| Parameter | Value | +|-------------------------------------------------|------------------------------------------------------------------------------------| +| ConferenceCreateRequest: lockedConference | Always set to FALSE. | +| ConferenceCreateRequest: conductibleConference | Always set to FALSE. | +| ConferenceCreateRequest: conductorPrivileges | Should never include ejectUser, add, lockUnlock or transfer. | +| ConferenceCreateRequest: conductedPrivileges | Should never include ejectUser, add, lockUnlock or transfer. | +| ConferenceCreateRequest: nonConductedPrivileges | Should never include ejectUser, add, lockUnlock or transfer. | +| ConferenceCreateResponse: result | Should always be set to userRejected if conference is already running on the node. | +| ConferenceQueryRequest: nodeType | Always set to terminal. | +| ConferenceQueryResponse: nodeType | Always set to terminal. | +| ConferenceJoinResponse: lockedConference | Always set to FALSE. | +| ConferenceJoinResponse: conductibleConference | Always set to FALSE. | +| ConferenceJoinResponse: conductorPrivileges | Should never include ejectUser, add, lockUnlock or transfer. | +| ConferenceJoinResponse: conductedPrivileges | No need to specify since conductorship is not supported. | + +**Table C.5 – Fixed parameter values for transmitted PDUs** + +| Parameter | Value | +|---------------------------------------------------|-----------------------------------------------------------------------------------------| +| ConferenceJoinResponse:
nonConductedPrivileges | Should never include ejectUser, add, lockUnlock or transfer. | +| ConferenceJoinResponse: result | If node is already connected to another node this should always be set to userRejected. | +| NodeRecord: nodeType | Always set to terminal. | +| NodeRecord: nodeProperties:
managementDevice | Always set to FALSE. | +| NodeRecord: nodeProperties: peripheralDevice | Always set to TRUE. | +| ApplicationRecord:
conductingOperationCapable | Always set to FALSE. | + +There is also an issue of how a node should handle a roster update for an APE that it does not support. This could be the case if a *T-Lite* node is participating in a point-to-point conference with a T.120 terminal node which can support multiple simultaneous APE sessions (say T.128, T.127 and T.126). If this should occur, it is up to the *T-Lite* node to process the roster update(s) associated with the APE(s) that it supports and ignore the rest. Note that, according to C.3.5, if the *T-Lite* node is the Top Provider, the unsupported APEs running on the terminal node will never see a roster update which includes itself and will therefore never complete the establishment of its session. + +#### C.3.4 Negotiating Top-Provider responsibilities + +As stated above, it is desirable for a *T-Lite* node to avoid Top-Provider responsibilities whenever possible. This prevents a node with minimal functionality from limiting the scope and services supported by the conference. Unfortunately, there is no definitive way to guarantee this. However, by following the rules for determining the default action of the called and calling nodes defined in Table C.6 below, along with the fixed parameters stated above, only one possible situation exists where a *T-Lite* node could assume Top Provider responsibilities in a conference. This is the situation where a *T-Lite* node is connected to another *T-Lite* node. If this situation occurs, the conference will be severely limited but it will still be able to proceed. Some of these limitations include: + +- no multipoint support; +- no "miscellaneous" services support; +- no "privilege" services such as eject user, add, transfer or lock/unlock; +- support for only a single APE. + +By following the rules in Table C.6 and setting the appropriate fixed parameters, the thin T.124 node has the greatest probability of joining the conference as a leaf or subordinate node. MCU/Terminals and MCUs will always default to the parent node in situations where it is connected to a *T-Lite* node. Note that, as mentioned in the overview, a *T-Lite* node can reduce its size even more if it is guaranteed to never be a Top Provider node (even in a point-to-point connection). + +**Table C.6 – Rules for determining the default action of the Called and Calling Nodes** + +| Calling Node type | Called Node type | Unlocked Conferences in List | Default Conference Flag | Wait for Invite Flag | No Unlisted Conference Flag | Default action of Calling Node | Default action of Called Node | +|-------------------------|------------------|------------------------------|-------------------------|----------------------|-----------------------------|--------------------------------|-------------------------------| +| T- Lite terminal | Any terminal | * | * | * | * | Caller creates remotely | Wait for caller | + +Table C.6 shows that whenever a T-*Lite* node initiates a call, it will always dial "upward" from MCS's perspective. This will guarantee that a fully compliant terminal will always end up as the Top Provider in a point-to-point call. Note that all other cases such as a T-*Lite* node calling an MCU should follow the terminal cases outlined in Table 7-17 of [ITU-T T.124] + +#### C.3.5 Support of a single static session + +T-*Lite* nodes that wish to support only a single static session may find it necessary to "filter" incoming session or roster information that is not relevant to the node. This could include roster update indications for non-static APE sessions or roster updates for APEs that are not supported by the T-*Lite* node. + +A GCC session is strictly defined by its associated Session Key which includes an Application Protocol Key and a Session ID. The Application Protocol Key is a unique identifier which defines the Application Protocol that created the session. The Session ID is simply the channel in use by that session (which in this case is a static channel). Roster updates associated with a particular session can be easily filtered if the T-*Lite* node knows in advance which static session(s) it must support. As stated above, this information would include the Application Protocol Key associated with the APE and the channel ID for the static session of interest. Any application information imbedded in a roster update indication that does not include the specified Session Key would simply be ignored. + +### C.4 Lite T.121 profile + +This clause describes the services required from a T.120 provider implementing the Generic Application Template (T.GAT or T.121) for a T-*Lite* node. For this portion of the T-*Lite* profile, only a subset of the GAT services is needed. These only include services associated with setting up a Static mode session. This is because only static channels and tokens are supported within the T-*Lite* MCS profile and no GCC registry-related functions are supported. Therefore, Dynamic Multicast and Dynamic Private session support can be ignored when building a T-*Lite* node. This greatly simplifies the effort required to support T-*Lite* from the perspective of an APE. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|---------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.123-200701-I_PDF-E/077f85b82901283b4657fd2b45fc0294_img.jpg 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The networks currently identified are ISDN, CSDN, PSDN, PSTN, B-ISDN, and LAN. Communication profiles are specified which provide reliable point-to-point connections between a terminal and a multipoint control unit, between pairs of terminals or between pairs of MCUs. In some cases, a lower protocol layer allows the multiplexing of audio and video signals in addition to data connections. In other cases, separate calls, over the same or a different network, may be established to carry audio or video signals. + +In addition, Annex B specifies a protocol that may be used to negotiate connection services beyond reliable data transfer. This protocol also provides for the use of alias address lists when making a connection. Alias lists will allow proxy services for T.120 communications to be created and used. + +This revised version of ITU-T Recommendation T.123 introduces a number of clarifications to the previous version. + +## Source + +ITU-T Recommendation T.123 was approved on 13 January 2007 by ITU-T Study Group 16 (2005-2008) under the ITU-T Recommendation A.8 procedure. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2007 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +# CONTENTS + +| | Page | +|------------------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 1.1 Networks identified ..... | 1 | +| 1.2 Audio and video signals ..... | 1 | +| 1.3 ISDN call set-up ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 5 | +| 4 Abbreviations and acronyms ..... | 5 | +| 5 Multipoint configuration..... | 6 | +| 6 Profile overview ..... | 7 | +| 7 Basic profiles ..... | 9 | +| 7.1 ISDN basic profile..... | 9 | +| 7.2 CSDN basic profile..... | 10 | +| 7.3 PSDN basic profile ..... | 11 | +| 7.4 PSTN basic profile ..... | 12 | +| 7.5 B-ISDN basic profile..... | 13 | +| 7.6 LAN basic profile ..... | 14 | +| 8 Packet header to delimit data units in an octet stream..... | 15 | +| 9 Synchronization and convergence function..... | 15 | +| 9.1 SCF overview ..... | 15 | +| 9.2 SCF procedures ..... | 17 | +| 9.3 SCF messages..... | 19 | +| 9.4 Quality of service parameters..... | 21 | +| 10 Q.922 protocol parameters and options ..... | 21 | +| 11 Data link frame structure transparency for start-stop transmission..... | 22 | +| 12 Physical sublayer formed by H.221 MLP channels..... | 23 | +| 13 Alternative profiles ..... | 25 | +| 13.1 Alternative: ISDN based on [ITU-T Q.922]..... | 25 | +| 13.2 Alternative: ISDN based on [ITU-T T.90] ..... | 26 | +| 13.3 Alternative: ISDN based on [ITU-T V.120]..... | 27 | +| 13.4 Alternative: PSTN based on [ITU-T H.324] ..... | 28 | +| 13.5 Alternative: B-ISDN based on [ITU-T H.222]..... | 28 | +| 13.6 Alternative: LAN based on data unit transfer..... | 29 | +| Annex A – Integration of multimedia signals framed according to [ITU-T H.221]..... | 31 | +| Annex B – Extended transport connections..... | 32 | +| B.1 Scope ..... | 32 | +| B.2 References ..... | 32 | +| B.3 Definitions ..... | 32 | + +| | Page | +|------------------------------------------------------------------|-------------| +| B.4 Abbreviations and acronyms ..... | 33 | +| B.5 Conventions ..... | 33 | +| B.6 Overview ..... | 33 | +| B.7 Extended transport connections ..... | 35 | +| B.8 Extended profiles ..... | 40 | +| B.9 Connection negotiation protocol (CNP) ..... | 46 | +| B.10 Unreliable segmentation and reassembly protocol ..... | 55 | +| Appendix I – Multimedia conference call set-up in the ISDN ..... | 58 | +| I.1 Introduction ..... | 58 | +| I.2 Basic requirements ..... | 58 | +| I.3 Connection phase ..... | 61 | +| I.4 Phase A (ISDN D-channel protocol) ..... | 62 | +| I.5 Phase B (H.242 protocol) ..... | 62 | +| I.6 Phase C (T.120-series protocol) ..... | 62 | +| Appendix II – GSS-API security framework ..... | 63 | +| II.1 Introduction ..... | 63 | +| II.2 IETF common authentication technology (CAT) ..... | 63 | +| II.3 T.123 Annex B security framework ..... | 63 | +| Bibliography ..... | 65 | + +# ITU-T Recommendation T.123 + +# Network-specific data protocol stacks for multimedia conferencing + +*(revised in 1999)* + +# 1 Scope + +This Recommendation, which defines protocol stacks for terminals and MCUs, specifies network-specific aspects of the T.120 protocol suite in the form of profiles for each network identified. Each profile specifies a set of protocols that extend to layer 4 of the OSI reference model. + +The rationale for this Recommendation is as follows: audiographic and video conferencing are intended to form part of the repertoire of ISDN services. Teleconferencing via ISDN involves the integration of multiple media (audio, video and data) in a connection, which may be the aggregate of a number of physical channels. The provision of these services is not, however, limited to the ISDN, and a range of other network scenarios is identified. For instance, CSDN may provide a similar, though less flexible, service to that of ISDN, and PSTN may provide a service that, though limited in performance, is more readily available. Teleconferencing may also be extended over PSDN and B-ISDN. LANs may provide conferencing locally within an enterprise or a means of access to wide area networks. + +## 1.1 Networks identified + +Network-specific profiles are defined for ISDN, CSDN, PSDN and PSTN, as required by [ITU-T F.702]. The scope of this Recommendation also includes B-ISDN and LAN. + +## 1.2 Audio and video signals + +The handling of audio and video signals in a multimedia conference is not part of this Recommendation, other than the possibility of their multiplexed transport over the same connection in some cases. + +## 1.3 ISDN call set-up + +Examples of ISDN call set-up procedures for the audiographic teleconference are given in Appendix I. These procedures illustrate: + +- a) the use of ISDN information elements; +- b) coordination of the D-channel and the B-channel; +- c) the phases of connection establishment; +- d) interworking with telephone services. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T F.702] ITU-T Recommendation F.702 (1996), *Multimedia conference services*. +- [ITU-T H.221] ITU-T Recommendation H.221 (2004), *Frame structure for a 64 to 1920 kbit/s channel in audiovisual teleservices*. +- [ITU-T H.222.0] ITU-T Recommendation H.222.0 (2006) | ISO/IEC 13818-1:2006, *Information technology – Generic coding of moving pictures and associated audio information: Systems*. +- [ITU-T H.223] ITU-T Recommendation H.223 (2001), *Multiplexing protocol for low bit rate multimedia communication*. +- [ITU-T H.230] ITU-T Recommendation H.230 (2004), *Frame-synchronous control and indication signals for audiovisual systems*. +- [ITU-T H.231] ITU-T Recommendation H.231 (1997), *Multipoint control units for audiovisual systems using digital channels up to 1920 kbit/s*. +- [ITU-T H.233] ITU-T Recommendation H.233 (2002), *Confidentiality system for audiovisual services*. +- [ITU-T H.242] ITU-T Recommendation H.242 (2004), *System for establishing communication between audiovisual terminals using digital channels up to 2 Mbit/s*. +- [ITU-T H.243] ITU-T Recommendation H.243 (2005), *Procedures for establishing communication between three or more audiovisual terminals using digital channels up to 1920 kbit/s*. +- [ITU-T H.310] ITU-T Recommendation H.310 (1998), *Broadband audiovisual communication systems and terminals*. +- [ITU-T H.320] ITU-T Recommendation H.320 (2004), *Narrow-band visual telephone systems and terminal equipment*. +- [ITU-T H.324] ITU-T Recommendation H.324 (2005), *Terminal for low bit-rate multimedia communication*. +- [ITU-T I.320] ITU-T Recommendation I.320 (1993), *ISDN protocol reference model*. +- [ITU-T I.321] ~~ITU-T E.321~~ ITU-T Recommendation I.321 (1991), *B-ISDN protocol reference model and its application*. +- [ITU-T I.361] ITU-T Recommendation I.361 (1999), *B-ISDN ATM layer specification*. +- [ITU-T I.363.1] ITU-T Recommendation I.363.1 (1996), *B-ISDN ATM Adaptation Layer specification: Type 1 AAL*. +- [ITU-T I.363.3] ITU-T Recommendation I.363.3 (1996), *B-ISDN ATM Adaptation Layer specification: Types 3/4 AAL*. +- [ITU-T I.363.5] ITU-T Recommendation I.363.5 (1996), *B-ISDN ATM Adaptation Layer specification: Type 5 AAL*. +- [ITU-T I.365.1] ITU-T Recommendation I.365.1 (1993), *B-ISDN ATM adaptation layer sublayers: Frame relaying service specific convergence sublayer (FR-SSCS)*. +- [ITU-T I.365.3] ITU-T Recommendation I.365.3 (1995), *B-ISDN ATM adaptation layer sublayers: Service-specific coordination function to provide the connection-oriented transport service*. +- [ITU-T I.430] ITU-T Recommendation I.430 (1995), *Basic user-network interface – Layer 1 specification*. + +- [ITU-T I.431] ITU-T Recommendation I.431 (1993), *Primary rate user-network interface – Layer 1 specification.* +- [ITU-T I.432.1] ITU-T Recommendation I.432.1 (1999), *B-ISDN user-network interface – Physical layer specification: General characteristics.* +- [ITU-T I.432.2] ITU-T Recommendation I.432.2 (1999), *B-ISDN user-network interface – Physical layer specification: 155 520 kbit/s and 622 080 kbit/s operation.* +- [ITU-T I.432.3] ITU-T Recommendation I.432.3 (1999), *B-ISDN user-network interface – Physical layer specification: 1544 kbit/s and 2048 kbit/s operation.* +- [ITU-T I.432.4] ITU-T Recommendation I.432.4 (1999), *B-ISDN user-network interface – Physical layer specification: 51 840 kbit/s operation.* +- [ITU-T Q.920] ITU-T Recommendation Q.920 (1993), *ISDN user-network interface data link layer – General aspects.* +- [ITU-T Q.921] ITU-T Recommendation Q.921 (1997), *ISDN user-network interface – Data link layer specification.* +- [ITU-T Q.921 bis] ITU-T Recommendation Q.921 bis (1993), *Abstract test suite for LAPD conformance testing.* +- [ITU-T Q.922] ~~ITU-T ECHT~~ Recommendation Q.922 (1992), *ISDN data link layer specification for frame mode bearer services.* +- [ITU-T Q.931] ITU-T Recommendation Q.931 (1998), *ISDN user-network interface layer 3 specification for basic call control.* +- [ITU-T Q.933] ITU-T Recommendation Q.933 (2003), *ISDN Digital Subscriber Signalling System No. 1 (DSS1) – Signalling specifications for frame mode switched and permanent virtual connection control and status monitoring.* +- [ITU-T Q.2110] ITU-T Recommendation Q.2110 (1994), *B-ISDN ATM adaptation layer – Service specific connection oriented protocol (SSCOP).* +- [ITU-T Q.2130] ITU-T Recommendation Q.2130 (1994), *B-ISDN signalling ATM adaptation layer – Service specific coordination function for support of signalling at the user-network interface (SSFC at UNI).* +- [ITU-T Q.2931] ITU-T Recommendation Q.2931 (1995), *Digital Subscriber Signalling System No. 2 – User-Network interface (UNI) layer 3 specification for basic call/connection control.* +- [ITU-T T.90] ~~ITU-T ECHT~~ Recommendation T.90 (1992), *Characteristics and protocols for terminals for telematic services in ISDN.* +- [ITU-T T.120] ITU-T Recommendation T.120 (2007), *Data protocols for multimedia conferencing.* +- [ITU-T T.122] ITU-T Recommendation T.122 (1998), *Multipoint communication service – Service definition.* +- [ITU-T T.124] ITU-T Recommendation T.124 (2007), *Generic Conference Control.* +- [ITU-T T.125] ITU-T Recommendation T.125 (1998), *Multipoint communication service protocol specification.* +- [ITU-T T.126] ITU-T Recommendation T.126 (1997), *Multipoint still image and annotation protocol.* +- [ITU-T T.127] ITU-T Recommendation T.127 (1995), *Multipoint binary file transfer protocol.* + +- [ITU-T V.7] ~~ITU-T CCITT~~ Recommendation V.7 (1988), *Definitions of terms concerning data communication over the telephone network.* +- [ITU-T V.8] ITU-T Recommendation V.8 (2000), *Procedures for starting sessions of data transmission over the public switched telephone network.* +- [ITU-T V.8 bis] ITU-T Recommendation V.8 bis (2000), *Procedures for the identification and selection of common modes of operation between data circuit-terminating equipments (DCEs) and between data terminal equipments (DTEs) over the public switched telephone network and on leased point-to-point telephone-type circuits.* +- [ITU-T V.14] ITU-T Recommendation V.14 (1993), *Transmission of start-stop characters over synchronous bearer channels.* +- [ITU-T V.34] ITU-T Recommendation V.34 (1998), *A modem operating at data signalling rates of up to 33 600 bit/s for use on the general switched telephone network and on leased point-to-point 2-wire telephone-type circuits.* +- [ITU-T V.42] ITU-T Recommendation V.42 (2002), *Error-correcting procedures for DCEs using asynchronous-to-synchronous conversion.* +- [ITU-T V.42 bis] ~~ITU-T CCITT~~ Recommendation V.42 bis (1990), *Data compression procedures for data circuit-terminating equipment (DCE) using error correction procedures.* +- [ITU-T V.61] ITU-T Recommendation V.61 (1996), *A simultaneous voice plus data modem, operating at a voice plus data signalling rate of 4800 bit/s, with optional automatic switching to data-only signalling rates of up to 14 400 bit/s, for use on the General Switched Telephone Network and on leased point-to-point 2-wire telephone type circuits.* +- [ITU-T V.70] ITU-T Recommendation V.70 (1996), *Procedures for the simultaneous transmission of data and digitally encoded voice signals over the GSTN, or over 2-wire leased point-to-point telephone type circuits.* +- [ITU-T V.120] ITU-T Recommendation V.120 (1996), *Support by an ISDN of data terminal equipment with V-series type interfaces with provision for statistical multiplexing.* +- [ITU-T X.21] ~~ITU-T CCITT~~ Recommendation X.21 (1992), *Interface between Data Terminal Equipment and Data Circuit-Terminating equipment for synchronous operation on public data networks.* +- [ITU-T X.21 bis] ~~ITU-T CCITT~~ Recommendation X.21 bis (1988), *Use on public data networks of Data Terminal Equipment (DTE) which is designed for interfacing to synchronous V-series modems.* +- [ITU-T X.25] ITU-T Recommendation X.25 (1996), *Interface between Data Terminal Equipment (DTE) and Data Circuit-terminating Equipment (DCE) for terminals operating in the packet mode and connected to public data networks by dedicated circuit.* +- [ITU-T X.200] ITU-T Recommendation X.200 (1994) | ISO/IEC 7498-1:1994, *Information technology – Open Systems Interconnection – Basic Reference Model: The basic model.* +- [ITU-T X.213] ITU-T Recommendation X.213 (2001) | ISO/IEC 8348:2002, *Information technology – Open Systems Interconnection – Network service definition.* + +- [ITU-T X.214] ITU-T Recommendation X.214 (1995) | ISO/IEC 8072:1996, *Information technology – Open Systems Interconnection – Transport service definition.* +- [ITU-T X.224] ITU-T Recommendation X.224 (1995) | ISO/IEC 8073:1997, *Information technology – Open Systems Interconnection – Protocol for providing the connection-mode transport service.* +- [ISO/IEC 3309] ISO/IEC 3309:1993, *Information technology – Telecommunications and information exchange between systems – High-level data link control (HDLC) procedures – Frame structure.* +- [ISO/IEC 7776] ISO/IEC 7776:1995, *Information technology – Telecommunications and information exchange between systems – High-level data link control procedures – Description of the X.25 LAPB-compatible DTE data link procedures.* +- [ISO/IEC 8208] ISO/IEC 8208:2000, *Information technology – Data communications – X.25 Packet Layer Protocol for Data Terminal Equipment.* +- [ISO/IEC 8802] ISO/IEC TR 8802-1:2001, *Information technology – Telecommunications and information exchange between systems – Local and metropolitan area networks specific requirements – Part 1: Overview of Local Area Network Standards.* + +# 3 Definitions + +This Recommendation uses the following terms defined in [ITU-T F.700]: + +- Audiographic conference service; +- Multipoint control unit. + +This Recommendation uses the following terms defined in [ITU-T I.320]: + +- Control plane; +- User plane. + +This Recommendation uses the following term defined in [ITU-T Q.920]: + +- Data link connection identifier. + +This Recommendation uses the following term defined in [ITU-T Q.922]: + +- Synchronization and convergence function. + +This Recommendation uses the following term defined in [ITU-T V.7]: + +- Start-stop transmission. + +This Recommendation uses the following term defined in [ITU-T X.213] and [ITU-T X.214]: + +- Quality of Service. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|--------|-----------------------------------------------| +| AAL | ATM Adaptation Layer | +| AL | Adaptation Layer | +| ATM | Asynchronous Transfer Mode | +| B-ISDN | Broadband Integrated Services Digital Network | +| CPCS | Common Part Convergence Sublayer | + +| | | +|-------|-----------------------------------------------| +| CSDN | Circuit Switched Data Network | +| DCE | Data Circuit-terminating Equipment | +| DLCI | Data Link Connection Identifier | +| DLSAP | Data Link Service Access Point | +| DTE | Data Terminal Equipment | +| FCS | Frame Check Sequence | +| ISDN | Integrated Services Digital Network | +| LAN | Local Area Network | +| MCS | Multipoint Communication Service | +| MCSAP | Multipoint Communication Service Access Point | +| MCU | Multipoint Control Unit | +| MLP | Multi-Layer Protocol | +| NSAP | Network Service Access Point | +| OSI | Open Systems Interconnection | +| PDU | Protocol Data Unit | +| PES | Packetized Elementary Stream | +| PhSAP | Physical Service Access Point | +| PSDN | Packet Switched Data Network | +| PSTN | Public Switched Telephone Network | +| QoS | Quality of Service | +| SCF | Synchronization and Convergence Function | +| SDU | Service Data Unit | +| TPDU | Transport Protocol Data Unit | +| TSAP | Transport Service Access Point | +| UNERM | Unacknowledged Non-Error Recovery Mode | +| VC | Virtual Channel | + +# 5 Multipoint configuration + +A multipoint configuration is created from point-to-point connections between three or more terminals and MCUs. Figure 1 shows a typical configuration where terminals are connected in a multipoint star around each MCU. It also shows how MCUs may be interconnected to form a larger conference. + +Figure 2 shows the framework of the T.120 protocol suite. This Recommendation defines the network-specific protocols in any direct connection between terminal and MCU, between two terminals, or between two MCUs. + +The point-to-point connections to a single MCU need not have identical communication profiles. Operation of the MCS protocol layer supports communication across different networks. + +If two terminals lack a common profile, they cannot be connected directly to one another. In that case, an MCU may serve as an intermediary making communication possible. This is a special example of multipoint configuration. + +![Figure 1: Typical multipoint configuration. A diagram showing three Multipoint Control Units (MCUs) connected in a triangular mesh. Each MCU is connected to two terminals. The top MCU is connected to one terminal above it and one to its right. The bottom-left MCU is connected to two terminals below it. The bottom-right MCU is connected to two terminals below it. All connections are bidirectional.](4e4be0bd8b235167902f2c03e41da651_img.jpg) + +T.123(01-07)\_F01 + +Figure 1: Typical multipoint configuration. A diagram showing three Multipoint Control Units (MCUs) connected in a triangular mesh. Each MCU is connected to two terminals. The top MCU is connected to one terminal above it and one to its right. The bottom-left MCU is connected to two terminals below it. The bottom-right MCU is connected to two terminals below it. All connections are bidirectional. + +**Figure 1 – Typical multipoint configuration** + +![Figure 2: Framework of the T.120 protocol suite. A diagram showing the protocol stack for a multimedia terminal and a multipoint control unit. The stack layers from top to bottom are: Multimedia terminal (T.126), Generic conference control (T.124), MCS (T.125), and Network aspects (T.123). The multimedia terminal stack is shown on the left and right. The multipoint control unit stack is in the center. The T.123 layer of the multipoint control unit is connected to three separate lines, each labeled 'Another terminal or MCU'. The T.123 layer of the multimedia terminal stacks is also connected to these lines.](ff0952ef692c9d960ce5f6708bcc9711_img.jpg) + +T.123(01-07)\_F02 + +Figure 2: Framework of the T.120 protocol suite. A diagram showing the protocol stack for a multimedia terminal and a multipoint control unit. The stack layers from top to bottom are: Multimedia terminal (T.126), Generic conference control (T.124), MCS (T.125), and Network aspects (T.123). The multimedia terminal stack is shown on the left and right. The multipoint control unit stack is in the center. The T.123 layer of the multipoint control unit is connected to three separate lines, each labeled 'Another terminal or MCU'. The T.123 layer of the multimedia terminal stacks is also connected to these lines. + +**Figure 2 – Framework of the T.120 protocol suite** + +# 6 Profile overview + +The general structure of the network-specific profiles is shown in Figure 3. Profiles are defined in detail in the following clauses. + +![Figure 3: Basic profiles general structure. A diagram showing the mapping of Multipoint communication service to various network profiles across four layers: Transport (layer 4), Network (layer 3), Data link (layer 2), and Physical (layer 1).](4801720824e4b5e2361a5564f91cfb70_img.jpg) + +| | Multipoint communication service | | | | | | +|---------------------|----------------------------------|-------------------------------|---------------------|--------------------------------------|----------------|---------------------------| +| Transport (layer 4) | X.224 class 0 | X.224 class 0 | X.224 class 0 | X.224 class 0 | X.224 class 0 | X.224 class 0/TPKT/stream | +| Network (layer 3) | Null + SCF | Null + SCF | X.25 | Null + SCF | Null + SCF | LAN network | +| Data link (layer 2) | Q.922 | Q.922 | X.25 | Q.922 | Q.922/AAL5 | LAN data link | +| Physical (layer 1) | H.221 MLP
I.430 or I.431 | H.221 MLP
X.21 or X.21 bis | X.21
or X.21 bis | Start-stop
use of
V-Series DCE | I.361
I.432 | LAN physical | +| | ISDN | CSDN | PSDN | PSTN | B-ISDN | LAN | + +T.123(01-07)\_F03 + +Figure 3: Basic profiles general structure. A diagram showing the mapping of Multipoint communication service to various network profiles across four layers: Transport (layer 4), Network (layer 3), Data link (layer 2), and Physical (layer 1). + +**Figure 3 – Basic profiles general structure** + +NOTE 1 – The use of [ITU-T Q.922] over ISDN does not imply the use of a frame relay bearer service. [ITU-T Q.922] is used to enhance the quality of service provided by the physical layer of an ISDN, CSDN, PSTN, or B-ISDN. This Recommendation exploits the error recovery mechanisms of Q.922 multiframe acknowledged mode for operation of one or more data links over a point-to-point connection provided by the corresponding network. + +The service that MCS requires from lower layers is the reliable, sequential, flow-controlled transfer of data units of unlimited size. One MCS connection consists of between one and four transport connections. The number depends on how many MCS data transfer priorities are implemented distinctly. + +Multiple transport connections are derived from a point-to-point connection over a specific network by multiplexing in some lower protocol layer. This occurs at layer 2 for those cases where [ITU-T Q.922] is used and at layer 3 where [ITU-T X.25] or a LAN protocol is used. + +Figure 4 shows the location of an MCS provider in the OSI reference model. An MCS provider exchanges MCS protocol data units with remote MCS providers. For this purpose, it uses transport-layer services. An MCS provider communicates with MCS users through an MCSAP by means of the MCS primitives defined in [ITU-T T.122]. + +![Diagram illustrating the location of an MCS provider in the OSI reference model. It shows two identical stacks of components connected horizontally. Each stack consists of three main boxes: 'MCS user' at the top, 'MCS provider' in the middle, and 'Network-specific lower layers' at the bottom. Between 'MCS user' and 'MCS provider' is an oval labeled 'T.122 service'. Between 'MCS provider' and 'Network-specific lower layers' is an oval labeled 'X.214 service'. To the left of the 'MCS user' oval is the label 'MCSAP' with an arrow pointing to the oval. To the right of the 'MCS provider' oval is the label 'T.122 service' with an arrow pointing to the oval. To the left of the 'X.214 service' oval is the label 'TSAP' with an arrow pointing to the oval. To the right of the 'X.214 service' oval is the label 'TSAP' with an arrow pointing to the oval. Horizontal dashed arrows connect the 'MCS provider' boxes and the 'Network-specific lower layers' boxes, labeled 'T.125 protocol' and 'Basic profile or alternative protocols' respectively. The identifier 'T.123(01-07)_F04' is at the bottom right.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg) + +Diagram illustrating the location of an MCS provider in the OSI reference model. It shows two identical stacks of components connected horizontally. Each stack consists of three main boxes: 'MCS user' at the top, 'MCS provider' in the middle, and 'Network-specific lower layers' at the bottom. Between 'MCS user' and 'MCS provider' is an oval labeled 'T.122 service'. Between 'MCS provider' and 'Network-specific lower layers' is an oval labeled 'X.214 service'. To the left of the 'MCS user' oval is the label 'MCSAP' with an arrow pointing to the oval. To the right of the 'MCS provider' oval is the label 'T.122 service' with an arrow pointing to the oval. To the left of the 'X.214 service' oval is the label 'TSAP' with an arrow pointing to the oval. To the right of the 'X.214 service' oval is the label 'TSAP' with an arrow pointing to the oval. Horizontal dashed arrows connect the 'MCS provider' boxes and the 'Network-specific lower layers' boxes, labeled 'T.125 protocol' and 'Basic profile or alternative protocols' respectively. The identifier 'T.123(01-07)\_F04' is at the bottom right. + +**Figure 4 – Location of an MCS provider in the OSI reference model** + +To simplify the address information that must be supplied when establishing an MCS connection, it is recommended that terminals and MCUs be administered so that null NSAP and TSAP selectors will resolve to a default MCS provider at the destination system. + +This does not preclude the possibility that a specific selector may be required to reach an MCS provider in a particular context. This may be the case, for example, if the data connection is to be associated with an audio or video connection that is established independently. It may also be the case if the MCS connection is to join a conference hosted in one partition of a large MCU. Ideally, the specific selector to be used will be communicated dynamically through some prior exchange. + +NOTE 2 – An NSAP selector may occur in the domain-specific part of an NSAP address. The format for this is not standardized. + +NOTE 3 – In each of the profiles specified here, the transport layer protocol is [ITU-T X.224]. It conveys TSAP selectors as TSAP-ID parameters of connection establishment TPDU. + +NOTE 4 – Annex B specifies the profiles that shall be used when establishing T.120 extended transport connections. + +# 7 Basic profiles + +When call set-up protocols or audio and video are shown in the profiles that follow, it is only to aid understanding. They are not a normative part of this Recommendation. + +## 7.1 ISDN basic profile + +Figure 5 defines the ISDN basic profile. + +![](fa859e4e468bfb2710a94527f2c504af_img.jpg) + +| | | | | | +|----------------|-----------------|---------------|-----------------|---------| +| Call set-up | | X.224 class 0 | | Layer 4 | +| Q.931 | | | Null + SCF | Layer 3 | +| Q.921 | | | Q.922 | Layer 2 | +| D-channel | Audio | Video | MLP | Layer 1 | +| | H.221 + H.242 | | | | +| | B- or H-channel | ... | B- or H-channel | | +| I.430 or I.431 | | | | | + +T.123(01-07)\_F05 + +**Figure 5 – ISDN basic profile** + +### *Layer 4* + +- X.224. +- Class 0 preferred, no alternative class. +- Maximum TPDU size shall not exceed layer 2 parameter N201. + +### *Layer 3* + +- User plane: null (no extra protocol during data transfer). +- Control plane: SCF as specified in clause 9. + +### *Layer 2* + +- Q.922. +- Protocol parameters and options as specified in clause 10, Q.922 protocol parameters and options. + +### *Layer 1* + +Sublayer formed by H.221 MLP channels: + +- As specified in clause 12, Physical sublayer formed by H.221 MLP channels. + +Sublayer formed by ISDN: + +- 1-6 B-channels, or 1-5 H0-channels, or 1 H1-channel. +- Unrestricted digital information, optionally with tones and announcements. +- B-channels may be rate-adapted to 56 kbit/s for restricted networks. +- D-channel is used for network signalling only, not for user data. + +NOTE – This Recommendation does not specify call set-up in the ISDN (although possible scenarios are illustrated in Appendix I). The SCF shown here operates only in the MLP channel, after ISDN call set-up and H.242 mode switching have occurred. + +## **7.2 CSDN basic profile** + +Figure 6 defines the CSDN basic profile. Layers above H.221 are identical to the ISDN basic profile. + +![Figure 6: CSDN basic profile diagram. A vertical stack of layers: Layer 4 (X.224 class 0), Layer 3 (Null + SCF), Layer 2 (Q.922), and Layer 1 (a sublayer with Audio, Video, and MLP channels). Layer 1 is further divided into H.221 + H.242 and X.21 or X.21 bis channels. A bracket on the right groups the bottom two rows of Layer 1.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg) + +| | | | | +|-------------------------|-------|-------------------------|---------| +| X.224 class 0 | | | Layer 4 | +| Null + SCF | | | Layer 3 | +| Q.922 | | | Layer 2 | +| Audio | Video | MLP | Layer 1 | +| H.221 + H.242 | | | | +| X.21 or X.21 bis | ... | X.21 or X.21 bis | | + +T.123(01-07)\_F06 + +Figure 6: CSDN basic profile diagram. A vertical stack of layers: Layer 4 (X.224 class 0), Layer 3 (Null + SCF), Layer 2 (Q.922), and Layer 1 (a sublayer with Audio, Video, and MLP channels). Layer 1 is further divided into H.221 + H.242 and X.21 or X.21 bis channels. A bracket on the right groups the bottom two rows of Layer 1. + +**Figure 6 – CSDN basic profile** + +### *Layer 4* + +- As specified in clause 7.1, ISDN basic profile. + +### *Layer 3* + +- As specified in clause 7.1, ISDN basic profile. + +### *Layer 2* + +- As specified in clause 7.1, ISDN basic profile. + +### *Layer 1* + +Sublayer formed by H.221 MLP channels: + +- As specified in clause 12, physical sublayer formed by H.221 MLP channels. + +Sublayer formed by CSDN: + +- X.21 or X.21 *bis* for each circuit switched connection. +- Bit rates shall be a uniform multiple of 64 kbit/s or 56 kbit/s. + +## **7.3 PSDN basic profile** + +Figure 7 defines the PSDN basic profile. + +![Figure 7: PSDN basic profile diagram. A vertical stack of layers: Layer 4 (X.224 class 0), Layer 3 (X.25), Layer 2 (X.25), and Layer 1 (X.21 or X.21 bis).](16da2d7b436c26f2efc4b51b2aae0fed_img.jpg) + +| | | +|----------------------------|---------| +| X.224 class 0 | Layer 4 | +| X.25 | Layer 3 | +| | Layer 2 | +| X.21
or X.21 bis | Layer 1 | + +T.123(01-07)\_F07 + +Figure 7: PSDN basic profile diagram. A vertical stack of layers: Layer 4 (X.224 class 0), Layer 3 (X.25), Layer 2 (X.25), and Layer 1 (X.21 or X.21 bis). + +**Figure 7 – PSDN basic profile** + +### Layer 4 + +- X.224. +- Class 0 preferred, no alternative class. + +### Layer 3 + +- X.25 virtual call service. + +### Layer 2 + +- X.25 LAPB single link procedure. + +### Layer 1 + +- X.21 or X.21 *bis*. + +## 7.4 PSTN basic profile + +Figure 8 defines the PSTN basic profile. Layers above Q.922 are identical to the ISDN basic profile. + +![](124c6108c63173818afb8ed49521e22d_img.jpg) + +| | | +|--------------------------------------|---------| +| X.224 class 0 | Layer 4 | +| Null + SCF | Layer 3 | +| Q.922 | Layer 2 | +| Start-stop
use of
V-series DCE | Layer 1 | + +T.123(01-07)\_F08 + +**Figure 8 – PSTN basic profile** + +### Layer 4 + +- As specified in 7.1, ISDN basic profile. + +### Layer 3 + +- As specified in 7.1, ISDN basic profile. + +### Layer 2 + +- Q.922. +- Protocol parameters and options as specified in clause 10, Q.922 protocol parameters and options. +- Modified frame transparency based on [ISO/IEC 3309] as specified in clause 11, Data link frame structure transparency for start-stop transmission. + +### Layer 1 + +- Start-stop transmission by DTE. +- When using V.14: one start bit, one stop bit, eight data bits, no parity. +- Any compatible V-series DCE operating over PSTN may be employed. +- The DTE and DCE may be logical functions that are not physically separated if integrated equipment can produce the same transmitted signals. + +- The choice of V-series DCE is unrestricted and includes, for example, V.34, V.61 and V.70 modems, with optional use of V.42 and V.42 *bis*. Selection of a compatible operating mode may be assisted by V.8 or V.8 *bis*. + +NOTE 1 – If the error control function of V.42 is activated, system parameters should be set to avoid adverse interaction with the error-correcting operation of Q.922. Important elements are the acknowledgement timer, the maximum number of octets in an information field, and the data forwarding conditions. + +NOTE 2 – The effectiveness of V.42 *bis* data compression will vary depending on how much of the application data exchanged in a conference has already been compressed by other means. + +NOTE 3 – V.70 DCE, if made aware that this profile is being employed, may negotiate between themselves the use of enhanced techniques, such as UNERM tunnelling for T.120, as long as the service provided at the DTE interface remains start-stop transmission. + +## 7.5 B-ISDN basic profile + +Figure 9 defines the B-ISDN basic profile. Layers above Q.922 are identical to the ISDN basic profile. + +![Diagram of the B-ISDN basic profile showing protocol layers and their components.](a734898ce18e972938949637c32a34f4_img.jpg) + +The diagram illustrates the B-ISDN basic profile across five layers. A central vertical column lists the protocols for each layer. To the left, a box labeled 'Call set-up' contains protocols Q.2931, Q.2130, Q.2110, and I.363. To the right, protocols are listed for each layer. Layer 1 is divided into two sections by a dashed line, with I.361 above and I.432 below. The source identifier T.123(01-07)\_F09 is located at the bottom right of the diagram. + +| | | | +|--|---------------|---------| +| | X.224 class 0 | Layer 4 | +| | Null + SCF | Layer 3 | +| | Q.922 | | +| | I.365.1 | Layer 2 | +| | I.363 AAL 5 | | +| | I.361 | Layer 1 | +| | I.432 | | + +T.123(01-07)\_F09 + +Diagram of the B-ISDN basic profile showing protocol layers and their components. + +**Figure 9 – B-ISDN basic profile** + +### Layer 4 + +- As specified in 7.1, ISDN basic profile. + +### Layer 3 + +- As specified in 7.1, ISDN basic profile. + +### Layer 2 + +- Q.922. +- Protocol parameters and options as specified in clause 10, Q.922 protocol parameters and options. +- PDU structure defined in Figure 3 of [ITU-T I.365.1] (no use of flags, transparency or FCS). +- PDU octets conveyed as one CPCS-SDU using AAL type 5. + +### Layer 1 + +- ATM virtual channel. + +## 7.6 LAN basic profile + +Figure 10 defines the LAN basic profile. + +![Diagram of the LAN basic profile showing six layers in a stack. Layer 4 (top) includes X.224 class 0, TPKT, and Stream. Layer 3 includes LAN layer 3. Layer 2 includes LAN layer 2. Layer 1 (bottom) includes LAN layer 1. Brackets on the right group the layers into Layer 4, Layer 3, Layer 2, and Layer 1. The reference T.123(01-07)_F10 is at the bottom.](5445597cceefaca1ac89e710fe339325_img.jpg) + +| | | +|---------------|---------| +| X.224 class 0 | Layer 4 | +| TPKT | | +| Stream | | +| LAN layer 3 | Layer 3 | +| LAN layer 2 | Layer 2 | +| LAN layer 1 | Layer 1 | + +T.123(01-07)\_F10 + +Diagram of the LAN basic profile showing six layers in a stack. Layer 4 (top) includes X.224 class 0, TPKT, and Stream. Layer 3 includes LAN layer 3. Layer 2 includes LAN layer 2. Layer 1 (bottom) includes LAN layer 1. Brackets on the right group the layers into Layer 4, Layer 3, Layer 2, and Layer 1. The reference T.123(01-07)\_F10 is at the bottom. + +**Figure 10 – LAN basic profile** + +### *Layer 4* + +- X.224 class 0 preferred, no alternative class. +- Default TPDU size 65531, but smaller values may be negotiated. +- TPKT packet header to delimit TPDU's, as specified in clause 8, Packet header to delimit data units in an octet stream. + +NOTE 1 – TPKT is required because an octet-stream service does not mark where data unit boundaries occur. + +- Octet-stream transfer with the following characteristics: + - a) Connection-oriented service preserving octet sequence. + - b) Boundary between data units *not* retained as part of the transfer. + - c) Residual error rate low enough to use as a type A network service. + - d) Flow control mechanism to exert back-pressure on a transmitter. + +NOTE 2 – The following specifies a protocol for octet-stream transfer that is a common example of the above: + +- a) RFC 793, Transmission control protocol. +- b) By default, destination port number 1503 per RFC 1700, Assigned numbers, but others may be used. + +### *Layer 3* + +- Commonly, RFC 791, 792, 919, 922, 950, 1112, Internet protocol. + +### *Layer 2* + +- Commonly, [ISO/IEC 8802] logical link control and medium access sublayers. + +### *Layer 1* + +- Commonly, [ISO/IEC 8802] physical medium. + +# 8 Packet header to delimit data units in an octet stream + +[ITU-T X.224] expects information to be transmitted and received in discrete units termed network service data units (NSDUs), which can be an arbitrary sequence of octets. Although other classes of the transport protocol may combine more than one TPDU inside a single NSDU, X.224 class 0 does not use this facility. Hence, in the context of T.123 protocol stacks, a TPDU may be identified with its underlying NSDU. + +A fundamental difference between the network service expected by [ITU-T X.224] and an octet-stream transfer service, as characterized in clause 7.6, is that the latter conveys a continuous sequence of octets with no explicit boundaries between related groups of octets. + +This clause specifies a distinct protocol layer to repair the discrepancy and meet the needs of [ITU-T X.224]. It defines a simple packet format whose purpose is to delimit TPDU. Each packet, termed a TPKT, is a unit composed of a whole integral number of octets, of variable length. + +A TPKT consists of two parts: a packet header, followed by a TPDU. The format of the packet header is constant, independent of the type of TPDU. The packet header consists of four octets as shown in Figure 11. + +![Diagram showing the format of the TPKT packet header. It consists of four octets: Octet 1 (0000 0011), Octet 2 (Reserved), Octet 3 (Most significant octet of TPKT length), and Octet 4 (Least significant octet of TPKT length). The TPDU follows, starting at Octet 5. The diagram is labeled T.123(01-07)_F11.](a24e89a6fe9bb70c83f8bf5202baba95_img.jpg) + +| | Octet | +|----------------------------------------|-------| +| 0 0 0 0 0 0 1 1 | 1 | +| Reserved | 2 | +| Most significant octet of TPKT length | 3 | +| Least significant octet of TPKT length | 4 | +| TPDU | 5-? | + +T.123(01-07)\_F11 + +Diagram showing the format of the TPKT packet header. It consists of four octets: Octet 1 (0000 0011), Octet 2 (Reserved), Octet 3 (Most significant octet of TPKT length), and Octet 4 (Least significant octet of TPKT length). The TPDU follows, starting at Octet 5. The diagram is labeled T.123(01-07)\_F11. + +Figure 11 – Format of the TPKT packet header + +Octet 1 is a version number, with binary value 0000 0011. Octet 2 is reserved for further study. Octets 3 and 4 are the unsigned 16-bit binary encoding of the TPKT length. This is the length of the entire packet in octets, including both the packet header and the TPDU. + +Since an X.224 TPDU occupies at least 3 octets, the minimum value of TPKT length is 7. The maximum value is 65535. This permits a maximum TPDU size of 65531 octets. + +NOTE – This description of the TPKT protocol layer agrees with RFC 1006, *ISO transport services on top of the TCP*. + +# 9 Synchronization and convergence function + +## 9.1 SCF overview + +The SCF resides in the network layer of each communication profile whose data link layer is specified to be Q.922. It coordinates network connection establishment and release between the control plane and the user plane as described in clause 4 of [ITU-T Q.922]. The purpose of the SCF is to provide network services to the transport layer. Figure 12 is the architectural model of the SCF. + +![Figure 12: Architectural model of the SCF. The diagram shows a multi-layered architecture. At the top is 'System mgmt' (Layer 4). Below it is 'NSAP' (Layer 3). The main body is divided into 'U-plane' and 'C-plane'. The 'U-plane' contains a 'NULL protocol' (dashed box) and a 'Q.922 data link entity' (solid box) with 'DLCI = N1, N2, ...'. The 'C-plane' contains a 'Q.922 data link entity' (solid box) with 'DLCI = 0'. Both planes have 'MDL-primitives' and 'mgmt' blocks. The 'U-plane' also has a 'U-plane layer 2' block. The 'C-plane' has a 'C-plane layer 2 mgmt' block. The 'Q.922 data link entity' blocks are connected to a 'Data link multiplex procedure' block. Above this block is a 'Synchronization and convergence function' block. Below it is a 'Physical layer protocol, e.g., H.221 MLP' block. The diagram is labeled with 'Layer 4', 'Layer 3', 'Layer 2', and 'Layer 1' on the right side. The source 'T.123(01-07)_F12' is at the bottom right.](e69b9188aa2c14ec6b21c83f711fef65_img.jpg) + +Figure 12: Architectural model of the SCF. The diagram shows a multi-layered architecture. At the top is 'System mgmt' (Layer 4). Below it is 'NSAP' (Layer 3). The main body is divided into 'U-plane' and 'C-plane'. The 'U-plane' contains a 'NULL protocol' (dashed box) and a 'Q.922 data link entity' (solid box) with 'DLCI = N1, N2, ...'. The 'C-plane' contains a 'Q.922 data link entity' (solid box) with 'DLCI = 0'. Both planes have 'MDL-primitives' and 'mgmt' blocks. The 'U-plane' also has a 'U-plane layer 2' block. The 'C-plane' has a 'C-plane layer 2 mgmt' block. The 'Q.922 data link entity' blocks are connected to a 'Data link multiplex procedure' block. Above this block is a 'Synchronization and convergence function' block. Below it is a 'Physical layer protocol, e.g., H.221 MLP' block. The diagram is labeled with 'Layer 4', 'Layer 3', 'Layer 2', and 'Layer 1' on the right side. The source 'T.123(01-07)\_F12' is at the bottom right. + +**Figure 12 – Architectural model of the SCF** + +Network services required by the X.224 transport protocol are listed in Table 1. This table is derived from Table 2 of [ITU-T X.224] by excluding optional features and N-RESET (because N-RESET is never requested, according to Table A.3 of [ITU-T X.224], and any indication of it can be escalated to N-DISCONNECT). + +**Table 1 – Network services required by X.224** + +| Primitives | Parameters | +|-------------------------------------------------|--------------------------------------------------------| +| N-CONNECT request
N-CONNECT indication | Called address
Calling address
QoS parameter set | +| N-CONNECT response
N-CONNECT confirm | Responding address
QoS parameter set | +| N-DATA request
N-DATA indication | NS user data | +| N-DISCONNECT request
N-DISCONNECT indication | | + +The SCF implements the N-CONNECT and N-DISCONNECT primitives. During data transfer it is inactive, and N-DATA maps directly to DL-DATA with no extra protocol. This requires that the transport layer limit the size of its TPDU's to one Q.922 I-frame. + +[ITU-T Q.922] supports multiple data link connections distinguished by DLCI. Acting through layer 2 management, the SCF controls DLCI assignments. It communicates with a peer SCF by + +sending and receiving Q.933 messages over DLCI 0, which is reserved for in-channel signalling. DLCI 0 serves the control plane, supporting SCF control. Other DLCIs serve the user plane, supporting data transfer. + +SCF procedures are based on those specified in [ITU-T Q.933], in which are defined case A covering circuit switched access to a remote frame handler, and case B covering integrated access to a local frame handler. The SCF use of Q.933 messages may be considered a new case C, covering circuit switched access directly to another network user. This new case C does not use DLCIs to distinguish connections to different destinations. It uses DLCIs to distinguish multiple connections between the same two end points. Each such connection may have a different quality of service. + +The sequence of actions to obtain a physical circuit between two users can vary with the communication profile and other circumstances. A circuit may be established without the aid of SCF prior to the first N-CONNECT request and indication. When these primitives are finally invoked, called and calling addresses may be omitted or ignored. Alternatively, N-CONNECT request may initiate events, and network addresses may be required for circuit routing. + +## 9.2 SCF procedures + +The SCF shall act as a network user required to act for Q.933 case A of frame relaying. It shall behave as though connected semi-permanently to a remote frame handler, even though the bit rate allotted to the physical circuit may not be exactly the same as an ISDN information transfer rate. + +The sole exception is clause 5.6 of ITU-T Rec. Q.933 (1995) concerning DLCI collisions. To maintain a symmetric relationship between two network users, the SCF shall give neither direction preference as incoming. Instead, it shall resolve collisions by forcing new DLCI selections on both sides, as specified in detail below. + +The SCF shall obey the additional requirements stated in the remainder of this clause. + +As soon as a duplex physical circuit is activated, the SCF shall assign and establish DLCI 0 to serve the control plane. DLCI 0 shall carry Q.933 messages in Q.922 I-frames. If DLCI 0 is ever re-established, which indicates a protocol error, the SCF shall cause it to be released. If DLCI 0 is ever released, the SCF shall remove all other DLCIs assigned to the physical circuit and shall indicate that their data links are disconnected. The SCF may then attempt to establish DLCI 0 again and reinitialize Q.933 signalling. + +As a positive response to SETUP, the SCF shall transmit CONNECT, and this shall be answered by CONNECT ACKNOWLEDGE. In this situation, there is no advantage in transmitting ALERTING, CALL PROCEEDING, or PROGRESS. If received, these messages may be ignored. + +The negative response to SETUP shall be RELEASE COMPLETE. This is also the simplest means of clearing an active call. In this situation there is no advantage in transmitting DISCONNECT, STATUS, or STATUS ENQUIRY. If received, these messages may stimulate the transmission of RELEASE COMPLETE. If RELEASE is received during most call states specified in [ITU-T Q.933], e.g., while the call is active but not while awaiting a response to SETUP or RELEASE, it shall cause the transmission of RELEASE COMPLETE. Although an unexpected RELEASE COMPLETE is considered a message sequence error, it achieves the intended effect of forcing the receiver to clear a call. + +Figure 13 shows the messages exchanged and primitives invoked during a successful N-CONNECT. This figure assumes that DLCI 0 is already established, as the result of exchanging SABME and UA when the physical circuit was activated. + +![Sequence diagram for N-CONNECT showing interactions between Network user, SCF, System management, and Layer 2 entity.](c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg) + +``` + +sequenceDiagram + participant NU1 as Network user + participant SCF1 as SCF + participant SM1 as System management + participant L2E1 as Layer 2 entity + participant L2E2 as Layer 2 entity + participant SM2 as System management + participant SCF2 as SCF + participant NU2 as Network user + + NU1->>SCF1: N-CONNECT.req + SCF1->>L2E1: DL-DATA.req + L2E1-->>L2E2: I[SETUP] +DLCI 0 + L2E2->>SCF2: DL-DATA.ind + SCF2->>NU2: N-CONNECT.ind + NU2-->>SCF2: N-CONNECT.rsp + SCF2->>SM2: M2N-ASSIGN.req + SM2->>L2E2: MDL-ASSIGN.req + L2E2->>SCF2: DL-DATA.req + SCF2-->>L2E2: I[CONNECT] +DLCI 0 + L2E2->>SCF1: DL-DATA.ind + SCF1->>SM1: M2N-ASSIGN.req + SM1->>L2E1: MDL-ASSIGN.req + L2E1->>SCF1: DL-DATA.req + L2E1-->>L2E2: I[CONNECT ACKNOWLEDGE] +DLCI 0 + SCF1->>SCF2: DL-DATA.ind + SCF2->>L2E2: DL-DATA.ind + L2E2-->>L2E1: SABME +DLCI in SETUP + L2E1->>SCF1: DL-ESTABLISH.req + SCF1-->>L2E2: UA +DLCI in SETUP + SCF2->>SCF1: DL-ESTABLISH.ind + SCF1->>SM1: DL-ESTABLISH.cnf + SM1->>L2E1: DL-ESTABLISH.cnf + L2E1->>NU1: N-CONNECT.cnf + +``` + +T.123(01-07)\_F13 + +Sequence diagram for N-CONNECT showing interactions between Network user, SCF, System management, and Layer 2 entity. + +**Figure 13 – Sequence of actions for N-CONNECT** + +The SCF shall employ one-octet call reference values (ranging from 1 to 127 on each side) and two-octet DLCI values (comprising 10 bits). DLCIs shall be selected randomly within the range allotted by [ITU-T Q.922] for support of user information, namely, from 16 to 991 inclusive. + +An SCF processing N-CONNECT request shall propose a preferred DLCI value in SETUP. An SCF receiving SETUP shall consider the DLCI value it contains. It is an error if the DLCI value is already assigned. If the receiving SCF has proposed the same DLCI value in an unanswered SETUP, it shall respond RELEASE COMPLETE with a cause number 44 *requested circuit/channel not available*. Otherwise, it shall accept the received DLCI value. Its response to SETUP shall then depend on a consideration of other parameters and the will of the network user. If the response is positive, the same DLCI value shall be returned in CONNECT; if negative, a cause number other than 44 shall be returned in RELEASE COMPLETE. An SCF receiving a response of RELEASE COMPLETE with cause 44 shall retry its failed SETUP with a new randomly selected DLCI value. If the number of retries seems excessive, the SCF may choose to reseed its random number + +generator. An SCF receiving a response of RELEASE COMPLETE with a cause number other than 44 shall indicate through N-DISCONNECT that the N-CONNECT request failed. + +Figure 14 shows the messages exchanged and the primitives invoked following a user-requested N-DISCONNECT. Note that DL-RELEASE request and the transmission of DISCONNECT are not required, because MDL-REMOVE on each side properly resets the state of the affected DLCI. + +![Sequence diagram showing the actions for N-DISCONNECT between Network user, SCF, System management, and Layer 2 entity.](552265bdbcf6d43d341fd018a9076269_img.jpg) + +``` + +sequenceDiagram + participant NU1 as Network user + participant SCF1 as SCF + participant SM1 as System management + participant L2E1 as Layer 2 entity + participant L2E2 as Layer 2 entity + participant SM2 as System management + participant SCF2 as SCF + participant NU2 as Network user + + NU1->>SCF1: N-DISCONNECT.req + SCF1->>L2E1: DL-DATA.req + L2E1->>L2E2: [[RELEASE COMPLETE]] + L2E2->>SCF2: DL-DATA.ind + SCF2->>NU2: N-DISCONNECT.ind + SCF1->>SM1: M2N-REMOVE.req + SM1->>L2E1: MDL-REMOVE.req + SCF2->>SM2: M2N-REMOVE.req + SM2->>L2E2: MDL-REMOVE.req + +``` + +The diagram illustrates the sequence of actions for N-DISCONNECT across four entities: Network user, SCF, System management, and Layer 2 entity. The process begins with a Network user sending an N-DISCONNECT.req to the SCF. The SCF then sends a DL-DATA.req to the Layer 2 entity. The Layer 2 entity responds with a [[RELEASE COMPLETE]] message to another Layer 2 entity, which then sends a DL-DATA.ind to the SCF. The SCF sends an N-DISCONNECT.ind to the Network user. Simultaneously, the SCF sends an M2N-REMOVE.req to System management, which sends an MDL-REMOVE.req to the Layer 2 entity. On the right side, the SCF sends an M2N-REMOVE.req to System management, which sends an MDL-REMOVE.req to the Layer 2 entity. + +Sequence diagram showing the actions for N-DISCONNECT between Network user, SCF, System management, and Layer 2 entity. + +T.123(01-07)\_F14 + +**Figure 14 – Sequence of actions for N-DISCONNECT** + +To avoid a race condition, the SCF should delay re-using its released call reference for a new call if it initiated N-DISCONNECT. The reason for this is that if both sides disconnect and the caller reconnects using the same call reference value, a RELEASE COMPLETE in transit for the old call may be misinterpreted as a failure of the new call. The probability of this occurring is minimized if the SCF chooses next its least recently used call reference value. In practice, a serial assignment of values (incrementing by one each time) may suffice. Alternatively, the SCF may choose to employ a more complicated disconnect procedure, transmitting RELEASE and awaiting RELEASE or RELEASE COMPLETE. + +An unrecovered error in data transfer over a DLCI is indicated by DL-ESTABLISH or by DL-RELEASE, depending on the success of resetting the data link. Either of these shall cause N-DISCONNECT to begin with an indication instead of a request, followed by the remaining actions of Figure 14. The exception is if DLCI 0 is affected; this has the more severe consequences specified earlier. + +## 9.3 SCF messages + +Information elements appear in a fixed order, as shown in Tables 2 through 5. Those of type M are either mandatory in [ITU-T Q.933] or required as part of the specification of this SCF. Those of type O are optional. Information elements that are not listed here should not be transmitted and may be ignored if received. + +NOTE 1 – If NSAP selectors for a default MCS provider are administered to be null as recommended in clause 6, there may be no advantage in carrying subaddress information elements as part of SETUP and CONNECT. However, specific selectors may be required to reach an MCS provider in a particular context. Their possible use to support protocols other than T.125 sharing the same physical circuit is for further study. + +NOTE 2 – The preferred binary encoding of an NSAP address is specified in clause A.5.3 of [ITU-T X.213]. + +**Table 2 – SETUP message content** + +| Information element | Type | Notes | +|--------------------------------|------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Protocol discriminator | M | ITU-T Rec. Q.922
Preferred
Cumulative, requested, maximum
N201, throughput(s), minimum(s)
k, T200
Data priority, lowest acceptable
NSAP address
NSAP address | +| Call reference | M | | +| Message type | M | | +| Bearer capability | M | | +| DLCI | M | | +| End-to-end transit delay | O | | +| Link layer core parameters | O | | +| Link layer protocol parameters | O | | +| X.213 priority | O | | +| Calling party subaddress | O | | +| Called party subaddress | O | | + +**Table 3 – CONNECT message content** + +| Information element | Type | Notes | +|--------------------------------|------|--------------------------------------------------------------------------------------------| +| Protocol discriminator | M | Exclusive
Cumulative
N201, throughput(s)
k, T200
NSAP address
Data priority | +| Call reference | M | | +| Message type | M | | +| DLCI | M | | +| End-to-end transit delay | O | | +| Link layer core parameters | O | | +| Link layer protocol parameters | O | | +| Connected subaddress | O | | +| X.213 priority | O | | + +**Table 4 – CONNECT ACKNOWLEDGE message content** + +| Information element | Type | +|------------------------|------| +| Protocol discriminator | M | +| Call reference | M | +| Message type | M | + +**Table 5 – RELEASE COMPLETE message content** + +| Information element | Type | +|------------------------|------| +| Protocol discriminator | M | +| Call reference | M | +| Message type | M | +| Cause | M | + +## 9.4 Quality of service parameters + +Important characteristics of data transfer performance are throughput, transit delay and priority. These are part of the QoS parameter set of N-CONNECT. QoS parameters are separate from, but may influence, the choice of protocol parameters. Parameters of both kinds may be conveyed by the SCF using optional information elements in SETUP and CONNECT. + +Parameter negotiations shall obey the rules of clauses 5.1.3.3 and 5.2.3.3 of ITU-T Rec. Q.933 (1995). + +Q.922 system parameters that may be negotiated are: k, N201 and T200. Their value shall be the same for both directions of transfer. If these parameters are not explicitly signalled, they shall take the default values of clause 10 below. + +If QoS parameters are not explicitly signalled, the corresponding qualities are indeterminate and may take any values that are convenient for the service providers. + +The QoS and protocol parameters in CONNECT, supplemented by any defaults, shall be final values for the assigned DLCI. The SCF shall pass these to the underlying layer 2 entity by M2N-ASSIGN, which emerges from the management plane as MDL-ASSIGN. This accords with clauses 4.1.1.5 and 4.1.1.10 of [ITU-T Q.922], which note that additional optional parameters may be included in these primitives. + +The QoS and protocol parameters of DLCI 0 are not explicitly signalled. The QoS shall implicitly equal or exceed that of any other DLCI. The protocol parameters k, N201 and T200 for DLCI 0 shall take the default values. + +A layer 2 entity may or may not implement data priority as a QoS parameter. If it does, the relative priority of DLCIs should determine the order of servicing user data requests queued for transmission, assuming that their respective protocol states are equally ready. DLCIs of the same priority should be treated impartially. + +The SCF shall express data priorities using the value encoding of the information element *X.213 priority* (which agrees with the encoding of the X.25 packet layer). The lowest priority shall be 0 and the highest shall be, at most, 14. Requested priorities shall be negotiated downward into the range of values, beginning with 0, that the underlying layer 2 entity can implement distinctly. + +# 10 Q.922 protocol parameters and options + +The address field format shall be two octets (10-bit DLCIs). + +Three bits of the address field are reserved for use with frame relaying service: forward explicit congestion notification (FECN), backward explicit congestion notification (BECN) and discard eligibility (DE). These bits shall be set to 0 by the transmitter and shall be ignored by the receiver. + +Information transfer shall be in I-frames using the procedures of multiple frame acknowledged operation. + +Frame types UI and XID shall not be transmitted. + +System parameters are associated with each individual data link connection. Their values should be set taking into account characteristics of the underlying physical circuit. Default values are specified in Table 6. + +**Table 6 – Data link default system parameter values** + +| System parameter | Default value | Parameter description | +|------------------|---------------|--------------------------------------------------| +| k | 40 | Maximum number of outstanding I-frames | +| N200 | 10 | Maximum number of retransmissions | +| N201 | 260 | Maximum number of octets in an information field | +| T200 | 1.5 s | Retransmission timer | +| T203 | 30 s | Idle timer | + +Values of k, N201 and T200 can be negotiated by the SCF specified in clause 9. The values of N200 and T203 need not be communicated from transmitter to receiver and may be set locally on each side. + +The default value of k is the maximum value cited in clause 5.9.4 of [ITU-T Q.922] (for a link speed of 1536-1920 Mbit/s). This is also the value cited in Appendix VI of [ITU-T T.90], independent of the link speed, for optimum throughput with a packet size of 256 octets. + +A value of k that is too large is better than a value that is too small. A Q.922 receiver need not accept a full window of I-frames if buffers are scarce; it can set the *own receiver busy* condition at some intermediate point. Moreover, a Q.922 transmitter can voluntarily limit itself to a smaller number of outstanding I-frames; it is not obliged to fill the window to maximum capacity. On the other hand, if k is set small and the window fills too quickly, a transmitter is required to cease. Throughput and response may suffer. + +Appendix I of [ITU-T Q.933] suggests a procedure to negotiate the value of k using a formula that involves the data frame size in octets. + +Implementers should consider the possibility of limiting frame size dynamically to a smaller value than system parameter N201 allows. This may require coordination with the transport layer that is forming TPDU's. It may be prudent to restrict the worst-case serial transmission time of lower priority data, so that newly queued data of higher priority can be serviced promptly. A maximum latency of 60 ms has been suggested. + +The alternative option of aborting a low priority transmission already in progress may also be considered. + +# **11 Data link frame structure transparency for start-stop transmission** + +Since start-stop transmission is organized as a sequence of octets, it is convenient to use an octet-stuffing scheme for data link frame structure transparency. This is a recognized alternative to the bit-stuffing scheme (insert a 0 bit after all sequences of five contiguous 1 bits) that is suitable for synchronous transmission. It makes the implementation of Q.922 for the PSTN profile easier and more efficient, especially when using the serial port of a typical personal computer. + +For the PSTN case, clause 2.6 of [ITU-T Q.922], which defines frame structure transparency by reference to [ITU-T Q.921], shall not be implemented. In its place shall be implemented the following procedures taken from clause 4.5.2 of [ISO/IEC 3309]: + +The control escape octet is a transparency identifier that identifies an octet occurring within a frame to which the following transparency procedure is applied. The encoding of the escape octet is given in Figure 15. + +![Diagram of a control escape octet for start-stop transparency. It shows an 8-bit octet with bits numbered 8 to 1 from left to right. The bit values are 0, 1, 1, 1, 1, 1, 0, 1. An arrow labeled 'Complemented bit' points to the 6th bit (value 1). Another arrow labeled 'First bit transmitted' points to the 1st bit (value 1). The reference T.123(01-07)_F15 is at the bottom right.](69b7bd65e85cdef6fdd7fb0a8194257c_img.jpg) + +8 7 6 5 4 3 2 1 + +| | | | | | | | | +|---|---|---|---|---|---|---|---| +| 0 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | +|---|---|---|---|---|---|---|---| + +Complemented bit      First bit transmitted + +T.123(01-07)\_F15 + +Diagram of a control escape octet for start-stop transparency. It shows an 8-bit octet with bits numbered 8 to 1 from left to right. The bit values are 0, 1, 1, 1, 1, 1, 0, 1. An arrow labeled 'Complemented bit' points to the 6th bit (value 1). Another arrow labeled 'First bit transmitted' points to the 1st bit (value 1). The reference T.123(01-07)\_F15 is at the bottom right. + +**Figure 15 – Control escape octet for start-stop transparency** + +The transmitter shall examine the frame content between the opening and closing flag sequences including the address, control and FCS fields and, following completion of the FCS calculation, shall: + +- a) upon the occurrence of the flag or a control escape octet, complement the 6th bit of the octet; and +- b) insert a control escape octet immediately preceding the octet resulting from the above prior to transmission. + +Other octet values may optionally be included in the transparency procedure by the transmitter. + +The receiver shall examine the frame content between the two flag octets and shall, upon receipt of a control escape octet and prior to FCS calculation: + +- a) discard the control escape octet; and +- b) restore the immediately following octet by complementing its 6th bit. + +A frame that ends with a control escape octet followed by a closing flag is invalid and shall be ignored by the receiver (frame abort). + +NOTE – This procedure does not preclude any particular character occurring within the transmitted data stream. In the case of separate DTE and DCE, flow control between them via command characters (XON/XOFF) must be disabled because it cannot be distinguished from the DTE-to-DTE transmission of the same characters. For this Recommendation, in this case, flow control is a function of the Q.922 protocol. + +# 12 Physical sublayer formed by H.221 MLP channels + +Use of the H.221 MLP and H-MLP channels shall conform to the specifications of [ITU-T H.221], [ITU-T H.230], [ITU-T H.233], [ITU-T H.242] and [ITU-T H.243] for the integration of multimedia signals: + +- To determine a compatible mode of operation, H.242 capability exchange sequence A applies. +- All systems capable of MLP shall declare at least the common capability MLP-6.4k. +- Other MLP and H-MLP bit rates defined by [ITU-T H.221] may also be declared. +- To establish or change mode, H.242 mode switching sequence B applies. +- Upon receipt of an H.221 command opening MLP or H-MLP, a system shall act to ensure that at least one of these is open in the opposite direction, so that full duplex communication may occur. +- The bit rates of MLP and H-MLP need not be the same in both directions of transmission unless symmetry is explicitly commanded. +- H.230 command MCS (multipoint command symmetrical data transmission) applies to MLP and H-MLP, requiring that the outgoing bit rates be set equal to the incoming bit rates. + +As suggested in clause 9.2 of [ITU-T H.242], if both MLP and H-MLP are in force, their bit rates shall be combined to form a single serial stream. Bit positions shall be numbered horizontally across the synchronized H.221 framing of initial and additional channels, as illustrated in Tables 7 through 9. + +H.221 commands to set the rate of MLP or H-MLP shall not disrupt the logical continuity of the combined serial stream. The input or output of bits shall simply continue in the next sub-multiframe at a modified rate. The operation of higher layer protocols will not be impacted unless the bit rate is reduced too low for a long period of time. + +In particular, MLP, H-MLP, or both may be turned off temporarily in the process of re-arranging the bit rates of a multimedia multiplex. This by itself is not sufficient cause to disconnect Q.922 data links involuntarily. That step shall only be taken, in the absence of protocol-detected errors, upon receipt of the H.221 command T.120-off. + +**Table 7 – Bit positions for MLP-6.4k, restricted, encryption active** + +| Initial channel | | | | | | | | +|-----------------------------------------------------------------------------------------------|---|---|---|---|---|-----|---| +| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | +| | | | | | | FAS | 1 | +| | | | | | | | 1 | +| | | | | | | | 1 | +| | | | | | | BAS | 1 | +| | | | | | | | 1 | +| | | | | | | | 1 | +| | | | | | | ECS | 1 | +| | | | | | | | 1 | +| | | | | | | | 1 | +| | | | | | | M1 | 1 | +| | | | | | | | 1 | +| | | | | | | | 1 | +| | | | | | | • | 1 | +| | | | | | | | 1 | +| | | | | | | | 1 | +| | | | | | | M55 | 1 | +| | | | | | | M56 | 1 | +| FAS Frame alignment signal
BAS Bit-rate allocation signal
ECS Encryption control signal | | | | | | | | + +**Table 8 – Bit positions for MLP-6.4k plus H-MLP-62.4k** + +| Initial channel | | | | | | | | Additional channel | | | | | | | | +|-----------------|---|---|---|---|---|---|------|--------------------|----|----|----|----|----|------|------| +| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | +| | | | | | | | FAS | M1 | M2 | M3 | M4 | M5 | M6 | M7 | FAS | +| | | | | | | | | M8 | • | • | • | • | • | M14 | | +| | | | | | | | | • | • | • | • | • | • | • | | +| | | | | | | | BAS | • | • | • | • | • | • | • | BAS | +| | | | | | | | | M106 | • | • | • | • | • | M112 | | +| | | | | | | | M113 | M114 | • | • | • | • | • | M120 | | +| | | | | | | | • | • | • | • | • | • | • | • | • | +| | | | | | | | • | • | • | • | • | • | • | • | • | +| | | | | | | | M680 | • | • | • | • | • | • | • | M688 | + +**Table 9 – Bit positions for H-MLP-128k in an H0 channel** + +| Time-slot 1 | Time-slot 2 | | | Time-slot 3 | | | Time-slot 4 | Time-slot 5 | Time-slot 6 | +|-------------|-------------|-------|----|-------------|-------|-------|-------------|-------------|-------------| +| | M1 | • • • | M8 | M9 | • • • | M16 | | | | +| | M17 | • • • | • | • | • • • | M32 | | | | +| | • | • • • | • | • | • • • | • | | | | +| | • | • • • | • | • | • • • | • | | | | +| | M1265 | • • • | • | • | • • • | M1280 | | | | + +# 13 Alternative profiles + +These alternatives are designed to allow point-to-point connections between terminals or MCUs in special circumstances. Their use may be specified in the system recommendation for a particular service or may be agreed bilaterally. + +The set of alternative profiles is not complete and is not intended to be an exhaustive list of all possibilities. + +No procedures are offered here by which terminals may discover the fact that they share a common profile, nor is any provision made for negotiation in the event that they share more than one. The coding of Q.931 or Q.2931 call control information elements can restrict the set of profiles that may be considered, but it cannot guarantee a successful outcome. Such concerns are part of a larger design, which may choose to reference this Recommendation. + +## 13.1 Alternative: ISDN based on [ITU-T Q.922] + +Figure 16 defines an alternative profile for ISDN based on [ITU-T Q.922]. When video is not required and audio can be assigned its own channel, this is a less expensive protocol stack to implement than H.221. Layers above the B- or H-channel are identical to the ISDN basic profile. + +![](692541e65db4dc852988ce77ebb60ce5_img.jpg) + +| | | | | +|----------------|--|-----------------|---------| +| Call set-up | | X.224 class 0 | Layer 4 | +| Q.931 | | Null + SCF | Layer 3 | +| Q.921 | | Q.922 | Layer 2 | +| D-channel | | B- or H-channel | Layer 1 | +| I.430 or I.431 | | | | + +T.123(01-07)\_F16 + +**Figure 16 – Alternative profile for ISDN based on [ITU-T Q.922]** + +### *Layer 4* + +- As specified in clause 7.1, ISDN basic profile. + +### *Layer 3* + +- As specified in clause 7.1, ISDN basic profile. + +### *Layer 2* + +- As specified in clause 7.1, ISDN basic profile. + +### *Layer 1* + +- One B-channel, one H0-channel, or one H1-channel. +- Some networks may also offer channels of intermediate bit rate. + +## 13.2 Alternative: ISDN based on [ITU-T T.90] + +Figure 17 defines an alternative profile for ISDN based on [ITU-T T.90]. Though less efficient than Q.922, the X.25 protocol stack is more familiar as a component of telematic terminals. + +![](e1476fd216f6cf773e262013fb4aba7d_img.jpg) + +| | | | | +|----------------|--|---------------|---------| +| Call set-up | | X.224 class 0 | Layer 4 | +| Q.931 | | ISO/IEC 8208 | Layer 3 | +| Q.921 | | ISO/IEC 7776 | Layer 2 | +| D-channel | | B-channel | Layer 1 | +| I.430 or I.431 | | | | + +T.123(01-07)\_F17 + +**Figure 17 – Alternative profile for ISDN based on [ITU-T T.90]** + +### Layer 4 + +- X.224. +- Class 0 preferred, no alternative class. + +### Layer 3 + +- DTE-DTE communication as specified in clause 2 of [ITU-T T.90]. + +### Layer 2 + +- DTE-DTE communication as specified in clause 2 [ITU-T T.90]. + +### Layer 1 + +- DTE-DTE communication as specified in clause 2 of [ITU-T T.90]. + +## 13.3 Alternative: ISDN based on [ITU-T V.120] + +Figure 18 defines an alternative profile for ISDN based on [ITU-T V.120]. This protocol stack gives a typical personal computer access to ISDN speeds through a common terminal adapter. Layers above the terminal adaptation are identical to the PSTN basic profile. + +![Figure 18: Alternative profile for ISDN based on [ITU-T V.120]. The diagram shows a protocol stack with two main columns. The left column is labeled 'Call set-up' and contains three boxes: 'Q.931', 'Q.921', and 'D-channel'. The right column contains four boxes: 'X.224 class 0', 'Null + SCF', 'Q.922', and a box split by a dashed line with 'Start-stop use of V.120' above and 'B-channel' below. To the right of these boxes are labels for Layer 4, Layer 3, Layer 2, and Layer 1. At the bottom, a wide box spans both columns and is labeled 'I.430 or I.431'. The reference 'T.123(01-07)_F18' is at the bottom right.](94acd33fcad85bb6f207a308f9b63191_img.jpg) + +| | | | | +|----------------|--|--------------------------------------------------|---------| +| Call set-up | | X.224 class 0 | Layer 4 | +| Q.931 | | Null + SCF | Layer 3 | +| Q.921 | | Q.922 | Layer 2 | +| D-channel | | Start-stop
use of V.120
-----
B-channel | Layer 1 | +| I.430 or I.431 | | | | + +T.123(01-07)\_F18 + +Figure 18: Alternative profile for ISDN based on [ITU-T V.120]. The diagram shows a protocol stack with two main columns. The left column is labeled 'Call set-up' and contains three boxes: 'Q.931', 'Q.921', and 'D-channel'. The right column contains four boxes: 'X.224 class 0', 'Null + SCF', 'Q.922', and a box split by a dashed line with 'Start-stop use of V.120' above and 'B-channel' below. To the right of these boxes are labels for Layer 4, Layer 3, Layer 2, and Layer 1. At the bottom, a wide box spans both columns and is labeled 'I.430 or I.431'. The reference 'T.123(01-07)\_F18' is at the bottom right. + +**Figure 18 – Alternative profile for ISDN based on [ITU-T V.120]** + +### Layer 4 + +- As specified in clause 7.1, ISDN basic profile. + +### Layer 3 + +- As specified in clause 7.1, ISDN basic profile. + +### Layer 2 + +- As specified in clause 7.1, ISDN basic profile. + +### Layer 1 + +- Start-stop transmission by DTE. +- DCE as specified in V.120 asynchronous mode operation. +- The DTE and DCE may be logical functions that are not physically separated if integrated equipment can produce the same transmitted signals. + +## 13.4 Alternative: PSTN based on [ITU-T H.324] + +Figure 19 defines an alternative profile for PSTN based on [ITU-T H.324]. This permits data conferencing to be widely deployed in conjunction with the PSTN videophone. Mapping Q.922 frames to AL-SDUs is a better use of scarce bandwidth than other possible framings. Layers above the adaptation are identical to the PSTN basic profile. + +![](cfb98c691c1af5befe32ff9442eea511_img.jpg) + +| | | | | +|-------|-------|-----------------------------------------------------|---------| +| | | X.224 class 0 | Layer 4 | +| | | Null + SCF | Layer 3 | +| | | Q.922 | Layer 2 | +| Audio | Video | T.120 start-stop
use of HDLC
frame tunnelling | Layer 1 | +| H.324 | | | | + +T.123(01-07)\_F19 + +**Figure 19 – Alternative profile for PSTN based on [ITU-T H.324]** + +### *Layer 4* + +- As specified in clause 7.1, ISDN basic profile. + +### *Layer 3* + +- As specified in clause 7.1, ISDN basic profile. + +### *Layer 2* + +- As specified in clause 7.4, PSTN basic profile. + +### *Layer 1* + +- Start-stop transmission by DTE. +- DCE as specified in H.324 HDLC frame tunnelling for [ITU-T T.120]. +- The DTE and DCE may be logical functions that are not physically separated if integrated equipment can produce the same transmitted signals. + +NOTE – The net effect is that the content of a Q.922 frame – including FCS but without flags or transparency – is conveyed as one AL-SDU using framed AL1 over an H.223 logical channel opened for the T.120 data application. + +## 13.5 Alternative: B-ISDN based on [ITU-T H.222] + +Figure 20 defines an alternative profile for B-ISDN based on [ITU-T H.222]. This protocol stack multiplexes audio, video and data together over a single ATM virtual channel. Layers above Q.922 are identical to the ISDN basic profile. + +![](f9c64800d9bace9b4315646d1057be3c_img.jpg) + +| | | | | | +|-------------|----------------------------------------|---------------|------------|---------| +| Call set-up | | X.224 class 0 | | Layer 4 | +| Q.2931 | | | Null + SCF | Layer 3 | +| Q.2130 | | | Q.922 | | +| | Audio | Video | I.365.1 | Layer 2 | +| Q.2110 | H.222.0 PES, transport stream, H.222.1 | | | | +| I.363 | I.363 AAL 1 or AAL 5 | | | | +| I.361 | | | | Layer 1 | +| I.432 | | | | | + +T.123(01-07)\_F20 + +**Figure 20 – Alternative profile for B-ISDN based on [ITU-T H.222]** + +### *Layer 4* + +- As specified in clause 7.1, ISDN basic profile. + +### *Layer 3* + +- As specified in clause 7.1, ISDN basic profile. + +### *Layer 2* + +- Q.922. +- Protocol parameters and options as specified in clause 10, Q.922 protocol parameters and options. +- Modified frame structure: no use of flags or transparency. +- Each frame (address octets through FCS) conveyed as the data bytes of one PES packet in the H.222.1-defined data elementary stream for protocol type T.120 subchannel. +- Transport stream transmission as specified in ITU-T Rec. H.222.1. + +NOTE – The `payload_unit_start_indicator` classifies each transport stream packet as containing either the first segment or a continuation segment of a PES packet. If a segment is less than the maximum size, the difference is absorbed by stuffing bytes before the PES packet header to a total of 188 bytes. + +### *Layer 1* + +- ATM virtual channel. + +## **13.6 Alternative: LAN based on data unit transfer** + +Figure 21 defines an alternative profile for LAN based on data unit transfer. By aligning TPDU's with data units of the underlying LAN, such a protocol stack can eliminate some buffer management. Though its segmentation feature may add nothing to what the LAN already offers, X.224 is recommended for uniformity and as a basis for future enhancements. + +NOTE 1 – No LAN protocol is named here, because the commercially important services are better known through their application programming interfaces. The protocols that support a service may be undisclosed or undocumented. + +![](e451401f8fa77b466f401d5fce15b26c_img.jpg) + +| | | +|--------------------|---------| +| X.224 class 0 | Layer 4 | +| Data unit transfer | | +| LAN layer 3 | Layer 3 | +| LAN layer 2 | Layer 2 | +| LAN layer 1 | Layer 1 | + +T.123(01-07)\_F21 + +**Figure 21 – Alternative profile for LAN based on data unit transfer** + +### *Layer 4* + +- X.224 class 0 preferred, no alternative class. +- Maximum TPDU size shall not exceed maximum LAN data unit. +- Data unit transfer with the following characteristics: + - a) Connection-oriented service preserving octet sequence. + - b) Boundary between data units retained as part of the transfer. + - c) Residual error rate low enough to use as a type A network service. + - d) Flow control mechanism to exert back-pressure on a transmitter. + +NOTE 2 – NetBIOS extended user interface (NetBEUI), NetWare sequenced packet exchange (SPX), and AppleTalk data stream protocol (ADSP) are examples of the above. + +NOTE 3 – In the case of SPX and ADSP, data unit boundaries are marked by setting an end-of-message bit. + +### *Layer 3* + +- Common examples include NetWare internetwork packet exchange (IPX) and Apple datagram delivery protocol (DDP). + +### *Layer 2* + +- Commonly, [ISO/IEC 8802] logical link control and medium access sublayers. + +### *Layer 1* + +- Commonly, [ISO/IEC 8802] physical medium. + +# Annex A + +## Integration of multimedia signals framed according to [ITU-T H.221] + +(This annex forms an integral part of this Recommendation) + +Figure A.1 illustrates how [ITU-T H.221] aggregates the throughput of one or more digital channels and then partitions the total transfer rate into bit rate allocations for the individual media. + +![Diagram illustrating the integration of multimedia signals framed according to ITU-T H.221.](08c7a76a7786bd08b99dd4cb41583ef4_img.jpg) + +The diagram shows a large oval representing the aggregate throughput of one or more channels. Inside this oval, a smaller oval represents the H.221 frame. The H.221 frame is divided into several sections: a top section labeled 'MLP and/or H-MLP', a middle section labeled 'Video', and a bottom section labeled 'Audio'. A dashed line indicates 'Other H.221 partitions'. The entire H.221 frame is labeled 'H.221'. The aggregate throughput is labeled 'Aggregate throughput of one or more channels'. The top section of the H.221 frame is also labeled 'I.430 or I.431'. The bottom section of the H.221 frame is labeled 'T.123(01-07)\_FA01'. + +Diagram illustrating the integration of multimedia signals framed according to ITU-T H.221. + +**Figure A.1 – Integration of multimedia signals framed +according to [ITU-T H.221]** + +# Annex B + +## Extended transport connections + +(This annex forms an integral part of this Recommendation) + +## B.1 Scope + +This annex defines the procedures and protocol that will allow transport connections for a T.120 conference to negotiate the availability of extended transport services. These services may include use of security protocols, transport protocols, levels of reliability for data transfer and support for address aliases. This negotiation is designed to provide backward compatibility with T.123 transport stacks that only support baseline transport connections. + +## B.2 References + +- [ITU-T H.225.0] ITU-T Recommendation H.225.0 (2006), *Call signalling protocols and media stream packetization for packet-based multimedia communication systems*. +- [ITU-T X.234] ITU-T Recommendation X.234 (1994) | ISO/IEC 8602:1995, *Information technology – Protocol for providing the OSI connectionless-mode transport service*. +- [ITU-T X.274] ITU-T Recommendation X.274 (1994) | ISO/IEC 10736:1995, *Information technology – Telecommunication and information exchange between systems – Transport layer security protocol*. +- [ITU-T X.680] ITU-T Recommendation X.680 (2002) | ISO/IEC 8824-1:2002, *Information technology – Abstract Syntax Notation One (ASN.1): Specification of basic notation*. +- [ITU-T X.681] ITU-T Recommendation X.681 (2002) | ISO/IEC 8824-2:2002, *Information Technology – Abstract Syntax Notation One (ASN.1): Information object specification*. +- [ITU-T X.691] ITU-T Recommendation X.691 (2002) | ISO/IEC 8825-2:2002, *Information technology – ASN.1 encoding rules – Specification of Packed Encoding Rules (PER)*. + +### B.3 Definitions + +This annex defines the following terms: + +**B.3.1 baseline transport stack:** A transport stack that does not support the procedures and protocol defined in this annex, but is otherwise compliant with T.123. + +**B.3.2 extended transport stack:** A T.123 transport stack that supports the procedures and protocol defined in this annex. + +**B.3.3 network connection:** A connection between two T.120 nodes using a specific set of protocols. + +**B.3.4 reliable protocol:** A protocol that guarantees that data will reach its destination complete, uncorrupted and in the order that it was transmitted. TCP is an example of a reliable protocol. + +**B.3.5 transport connection:** A logical connection between two T.120 nodes using one or more network connections. + +**B.3.6 unreliable protocol:** A protocol that does not guarantee that data will reach its destination complete, uncorrupted and in the order that it was transmitted. UDP is an example of an unreliable protocol. + +## B.4 Abbreviations and acronyms + +This annex uses the following abbreviations and acronyms: + +| | | +|--------|-------------------------------------------------------------------------------------------------| +| CNP | Connection Negotiation Protocol | +| CNPPDU | Connection Negotiation Protocol – Protocol Data Unit | +| IKE | Internet Key Exchange | +| IP | Internet Protocol | +| IPSec | Internet Protocol Security | +| MAP | Multicast Adaptation Protocol (defined in Annex A of [ITU-T T.125]) | +| MCS | Multipoint Communication Service | +| NSDU | Network Service Data Unit | +| PDU | Protocol Data Unit | +| SA ID | Security Association Identification | +| SAR | Segmentation And Reassembly | +| SSL | Secure Sockets Layer | +| TCP | Transmission Control Protocol | +| TLS | Transport Layer Security (protocol, defined by IETF RFC 4346 Internet draft ) | +| TLSP | Transport Layer Security Protocol (defined in [ITU-T X.274]) | +| TPDU | Transport Protocol Data Unit | +| TSDU | Transport Service Data Unit | +| UDP | User Datagram Protocol | + +## B.5 Conventions + +- In this annex, "shall" refers to a mandatory requirement, while "should" refers to a suggested but optional feature or procedure. The term "may" refers to an optional course of action without expressing a preference. +- Unless otherwise specified, the aligned variant PER encoding of ASN.1 shall be used for all ASN.1 specified in this annex. +- Bits in an octet are numbered from 1 to 8, where bit 1 is the lowest order bit. +- Octets in a TPDU are numbered starting from 1 and increasing in the order they are put into an NSDU. +- All X.224 messages and message fields are in *ITALICIZED CAPS*. +- All ASN.1 and octet structure elements for CNP are in **Bold**. + +## B.6 Overview + +T.123 baseline transport service is limited to the fully reliable transfer of data between nodes. A need for transport services not supported in baseline transport stacks has been identified. These services include security, unreliable data transfer and addressing by aliases. + +Because the X.224 protocol cannot be arbitrarily extended, these services cannot simply be added to T.123's definition of a baseline transport connection while retaining backward compatibility. In response to this problem, the procedures and protocol in this annex define an extended transport connection with services that can be negotiated and extended. + +#### B.6.1 Extended transport connection model + +The model for a T.123 baseline transport connection is shown in Figure B.1. Connections of this type provide communication service between T.120 nodes using a single, reliable network connection. The specific network address of the called node must be known for a connection of this type to be established. In addition, neither security services nor unreliable data transfer services can be provided with this type of connection. + +![Figure B.1: Baseline transport connection model. This diagram shows two T.120 nodes, 'T.120 node #1' on the left and 'T.120 node #2' on the right. They are connected via a central shaded box labeled 'Baseline transport connection'. Inside this box, a horizontal double-headed arrow is labeled 'Reliable network service'. The connection lines from the nodes enter the box and cross each other before reaching the central service arrow. The identifier 'T.123(01-07)_FB01' is located at the bottom right of the diagram.](e151d3468319b81f042ca232c4d82e4b_img.jpg) + +Figure B.1: Baseline transport connection model. This diagram shows two T.120 nodes, 'T.120 node #1' on the left and 'T.120 node #2' on the right. They are connected via a central shaded box labeled 'Baseline transport connection'. Inside this box, a horizontal double-headed arrow is labeled 'Reliable network service'. The connection lines from the nodes enter the box and cross each other before reaching the central service arrow. The identifier 'T.123(01-07)\_FB01' is located at the bottom right of the diagram. + +**Figure B.1 – Baseline transport connection model** + +To add extended services to T.123 transports, a new connection model is being defined. This model is shown in Figure B.2. In this model, a transport connection consists of one or more network services, logically bound. These services may include reliable and unreliable data transfer as well as security services for transmitted data. This model is functionally equivalent to the baseline model when all optional services are omitted. + +![Figure B.2: Extended transport connection model. This diagram shows two T.120 nodes, 'T.120 node #1' on the left and 'T.120 node #2' on the right. They are connected via a central shaded box labeled 'Extended transport connection'. Inside this box, there are two horizontal paths. The top path consists of a 'Security service (optional)' box on the left, a 'Reliable network service' arrow in the center, and a 'Security service (optional)' box on the right. The bottom path consists of a 'Security service (optional)' box on the left, an 'Unreliable network service (optional)' arrow in the center, and a 'Security service (optional)' box on the right. The connection lines from the nodes enter the box and branch out to connect to the service boxes. The identifier 'T.123(01-07)_FB02' is located at the bottom right of the diagram.](0b3d9fe35da3ee0c88f1420bb9ed7a03_img.jpg) + +Figure B.2: Extended transport connection model. This diagram shows two T.120 nodes, 'T.120 node #1' on the left and 'T.120 node #2' on the right. They are connected via a central shaded box labeled 'Extended transport connection'. Inside this box, there are two horizontal paths. The top path consists of a 'Security service (optional)' box on the left, a 'Reliable network service' arrow in the center, and a 'Security service (optional)' box on the right. The bottom path consists of a 'Security service (optional)' box on the left, an 'Unreliable network service (optional)' arrow in the center, and a 'Security service (optional)' box on the right. The connection lines from the nodes enter the box and branch out to connect to the service boxes. The identifier 'T.123(01-07)\_FB02' is located at the bottom right of the diagram. + +**Figure B.2 – Extended transport connection model** + +In addition to security and reliability services, this annex specifies a method for using an alias address list to establish extended transport connections. These aliases can be used for a variety of purposes, including proxy, gateway and call redirection services for T.120 communications. An example of this type of extended transport connection is shown in Figure B.3. + +![Figure B.3: Example of extended transport connection via T.120 proxy. The diagram shows two T.120 nodes (node #1 and node #2) on the left. Each node has a 'Network services' arrow pointing to a central 'Extended transport connection' block. This block is connected via 'Network services' arrows to two 'T.120 firewall proxy service' blocks. These proxy services are connected via 'Network services' arrows to 'Alias resolution service' blocks. The entire system is enclosed in a dashed box labeled 'T.120 alias resolution and proxy services'. A reference 'T.123(01-07)_FB03' is at the bottom right.](9a5927586a691c4908aa2cf98bd47ebb_img.jpg) + +Figure B.3: Example of extended transport connection via T.120 proxy. The diagram shows two T.120 nodes (node #1 and node #2) on the left. Each node has a 'Network services' arrow pointing to a central 'Extended transport connection' block. This block is connected via 'Network services' arrows to two 'T.120 firewall proxy service' blocks. These proxy services are connected via 'Network services' arrows to 'Alias resolution service' blocks. The entire system is enclosed in a dashed box labeled 'T.120 alias resolution and proxy services'. A reference 'T.123(01-07)\_FB03' is at the bottom right. + +**Figure B.3 – Example of extended transport connection via T.120 proxy** + +#### B.6.2 Transport services + +While a variety of transport services may be negotiated using the procedures and protocol in this annex, the exact specification of many of these services is beyond the scope of this Recommendation. In particular, service definitions for T.120 gateways and proxies are topics for future study. + +It should also be noted that many security services are implicitly defined in this annex. Where not otherwise specified, the mechanisms used to provide and control these services (e.g., obtaining certificates and out of band key exchange) are left to implementers. + +#### B.6.3 Modified use of X.224 + +[ITU-T T.123] mandates the use of the X.224 class 0 protocol for baseline connections. It is desirable that extended connection establishment remain compatible with baseline connection establishment. To achieve this goal, the information for extended connection negotiations will be encapsulated within the X.224 *CONNECTION REQUEST (CR)*, *CONNECTION CONFIRM (CC)* and *DISCONNECT REQUEST (DR)* TPDU. The details for this procedure are given in clause B.7, Extended transport connections. + +#### B.6.4 Connection negotiation protocol + +This annex defines the protocol that will be used to establish extended transport connections. The connection negotiation protocol (CNP) is designed for encapsulation within X.224 or for use as a stand-alone protocol over a reliable network connection. To allow the protocol to be extended, CNP is defined using ASN.1 for its control PDUs. The details of CNP are given in clause B.9, Connection negotiation protocol (CNP). + +## B.7 Extended transport connections + +The purpose of this clause is to define the procedure for establishing extended transport connections. This extended connection procedure is designed to allow a T.120 node to establish a transport connection to another T.120 node without prior knowledge about the called node's ability to support extended transport connections. + +#### B.7.1 Initial connection establishment + +[ITU-T X.224] defines the *TRANSPORT-SELECTOR* field as an optional, variable length field in the variable part of its PDU headers. As defined in clause 6.5.5 of [ITU-T X.224], it "indicates the calling and called transport service access points". This optional field is not used by X.224, or by baseline T.123. This clause defines its use for T.120 nodes to support extended transport connections. + +Nodes supporting extended transport connections shall support the use of the *TRANSPORT-SELECTOR* field in the X.224 *CONNECTION REQUEST (CR)* TPDU and the *CONNECTION CONFIRM (CC)* TPDU. The variable part of the *DISCONNECT REQUEST (DR)* TPDU shall also be supported. The *TRANSPORT-SELECTOR* field of the *CR-TPDU*, *CC-TPDU* and the variable part of *DR-TPDU* shall contain CNP PDUs as specified in clause B.9. In all cases, the 128-octet limit set by X.224 for the *CR-TPDU* and the *DR-TPDU* shall be respected. + +T.120 nodes supporting extended transport connections shall support the following call models. + +##### B.7.1.1 Call establishment from a baseline transport + +This call model is used when a T.120 node that supports only baseline connections attempts to connect to a node that supports extended connections. See Figure B.4. + +![Sequence diagram showing call establishment from a baseline T.123 node to an extended T.123 node. The calling node (baseline T.123) sends a CR (Connection Request) to the called node (extended T.123). The called node responds with either a CC (Connection Confirm) or a DR (Disconnect Request).](82fbb97c1145cac89ac72dd080fad17a_img.jpg) + +``` +sequenceDiagram + participant C as Calling node +(baseline T.123) + participant D as Called node +(extended T.123) + C->>D: CR + D-->>C: CC or DR +``` + +T.123(01-07)\_FB04 + +Sequence diagram showing call establishment from a baseline T.123 node to an extended T.123 node. The calling node (baseline T.123) sends a CR (Connection Request) to the called node (extended T.123). The called node responds with either a CC (Connection Confirm) or a DR (Disconnect Request). + +**Figure B.4 – Call from baseline T.123 +to extended T.123** + +This model is signalled at the called node when a *CR-TPDU* is received which does not contain a *TRANSPORT-SELECTOR* field. In this case, the called node shall respond according to the connection establishment defined for baseline T.123 connections. A response of *CC-TPDU* shall not contain a *TRANSPORT-SELECTOR* field. A response of *DR-TPDU* shall not contain the variable part of the PDU header. If the connection is accepted, the called node shall treat the connection as a baseline connection. + +##### B.7.1.2 Call establishment to a baseline transport + +This call model is used when a T.120 node that supports extended connections attempts to connect to a node supporting only baseline connections. See Figure B.5. + +![Sequence diagram for Figure B.5 showing a call from an extended T.123 node to a baseline T.123 node. The calling node sends a CR message, and the called node responds with a CC or DR message.](798679874d1c29f8343506a156c79d7e_img.jpg) + +``` + +sequenceDiagram + participant C as Calling node +(extended T.123) + participant S as Called node +(baseline T.123) + C->>S: CR + S-->>C: CC or DR + +``` + +T.123(01-07)\_FB05 + +Sequence diagram for Figure B.5 showing a call from an extended T.123 node to a baseline T.123 node. The calling node sends a CR message, and the called node responds with a CC or DR message. + +**Figure B.5 – Call from extended T.123 to baseline T.123** + +In this model, the calling node shall place a *TRANSPORT-SELECTOR* field in the *CR-TPDU*. The baseline node will ignore the field and respond with a *CC-TPDU* without a *TRANSPORT-SELECTOR* field or a *DR-TPDU* without a variable part. This call model is signalled to the calling node when the response TPDU is received and it does not contain the appropriate optional field. If the connection is accepted, the calling node shall treat the connection as a baseline connection. + +##### B.7.1.3 Call establishment using the initial network connection + +This call model is used when a T.120 node supporting extended connections attempts to connect to a node that also supports extended connections. For this case, the called node determines that the services available with the existing network connection are sufficient and the T.120 connection is accepted. See Figure B.6. + +![Sequence diagram for Figure B.6 showing a call between two extended T.123 nodes. The calling node sends a CR message, and the called node responds with a CC message.](9a14684f8ae1345c6efea6f5994c730c_img.jpg) + +``` + +sequenceDiagram + participant C as Calling node +(extended T.123) + participant S as Called node +(extended T.123) + C->>S: CR + S-->>C: CC + +``` + +T.123(01-07)\_FB06 + +Sequence diagram for Figure B.6 showing a call between two extended T.123 nodes. The calling node sends a CR message, and the called node responds with a CC message. + +**Figure B.6 – Call between extended T.123 nodes – Existing network connection selected** + +In this model, the calling node shall place a *TRANSPORT-SELECTOR* field in the *CR-TPDU*. The called node shall examine this field to determine if the existing network connection is to be maintained. If so, it shall respond with a *CC-TPDU* containing a *TRANSPORT-SELECTOR* field. This call model is signalled at the calling node when it receives the *CC-TPDU* containing the optional field. + +Note that negotiated transport protocol changes may occur after the initial PDU exchange is complete, providing the existing network connection is maintained. Changes in transport protocol shall occur as if the network connection was newly created. Full connection procedures for the negotiated transport protocol shall occur over the existing network connection. + +##### B.7.1.4 Call establishment by network reconnection + +This call model is used when a T.120 node supporting extended connections attempts to connect to a node that also supports extended connections. For this case, the called node determines that the services available with the existing network connection are insufficient for the T.120 connection. + +The connection attempt is rejected, but sufficient information is returned to the caller to allow a successful reconnection. See Figure B.7. + +![Sequence diagram for Figure B.7 showing a call between extended T.123 nodes where reconnection is selected. The calling node (extended T.123) sends a CR message to the called node (extended T.123). The called node responds with a DR message. The calling node then establishes a new network connection (indicated by a dashed arrow) and a transport connection (indicated by a solid arrow). The diagram is labeled T.123(01-07)_FB07.](b05bae46f7079e5c9b1da38adb2319e8_img.jpg) + +``` + +sequenceDiagram + participant C as Calling node +(extended T.123) + participant S as Called node +(extended T.123) + C->>S: CR + S-->>C: DR + C-->>S: Network connection + C-->>S: Transport connect + C-->>S: ... + +``` + +T.123(01-07)\_FB07 + +Sequence diagram for Figure B.7 showing a call between extended T.123 nodes where reconnection is selected. The calling node (extended T.123) sends a CR message to the called node (extended T.123). The called node responds with a DR message. The calling node then establishes a new network connection (indicated by a dashed arrow) and a transport connection (indicated by a solid arrow). The diagram is labeled T.123(01-07)\_FB07. + +**Figure B.7 – Call between extended T.123 nodes – Reconnection selected** + +In this model, the calling node shall place a *TRANSPORT-SELECTOR* field in the *CR-TPDU*. The called node will examine the field. If the called node determines that the existing network connection services are not sufficient, a new network connection may be required. In this case, the called node shall respond with a *DR-TPDU* containing a variable part. + +This call model is signalled at the calling node when it receives the *DR-TPDU* containing the optional field. + +After receiving the *DR-TPDU* containing the optional field, the calling node shall close the existing network connection. The caller shall then create a new network connection using the protocols, services and addresses returned in the variable part of *DR-TPDU*. Details of the reconnection procedure are given in clause B.9.5.2, Reconnection procedures. + +Note that this reconnection procedure may occur more than once in the establishment of a single transport connection, if it is deemed necessary to establish the required transport services. + +##### **B.7.1.5 Connection refusal** + +This call model is used when a T.120 node supporting extended connections attempts to connect to any node that does not wish to accept the connection. See Figure B.8. + +![Sequence diagram for Figure B.8 showing a call refusal. The calling node (extended T.123) sends a CR message to the called node (any). The called node responds with a DR message. The diagram is labeled T.123(01-07)_FB08.](0d0897dd7f03672d186db9d56ea0d6f5_img.jpg) + +``` + +sequenceDiagram + participant C as Calling node +(extended T.123) + participant S as Called node +(any) + C->>S: CR + S-->>C: DR + +``` + +T.123(01-07)\_FB08 + +Sequence diagram for Figure B.8 showing a call refusal. The calling node (extended T.123) sends a CR message to the called node (any). The called node responds with a DR message. The diagram is labeled T.123(01-07)\_FB08. + +**Figure B.8 – Call refusal** + +In this model, the calling node shall place a *TRANSPORT-SELECTOR* field in the *CR-TPDU*. The called node may examine the field. If the called node determines that the transport connection is to be refused, the caller shall respond with a *DR-TPDU* that does not contain a variable part. This call model is signalled at the calling node when it receives the *DR-TPDU* without the optional field. + +Reasons for refusing a connection are a matter left to implementers. These may include security incompatibility, exceeded connection limits, or other local policy violations. + +##### B.7.1.6 Abandoned connection attempt + +This call model is used when a T.120 node supporting extended connections attempts to connect to any node and the calling node decides to abandon the call attempt before the connection is completed. See Figure B.9. + +![Sequence diagram showing an abandoned call attempt between a Calling node (extended T.123) and a Called node (any). The Calling node sends a CR message, and the Called node responds with a DR message. The diagram is labeled T.123(01-07)_FB09.](f142b022cfc716cd967297f027efe647_img.jpg) + +``` + +sequenceDiagram + participant C as Calling node +(extended T.123) + participant S as Called node +(any) + C->>S: CR + S-->>C: DR + +``` + +T.123(01-07)\_FB09 + +Sequence diagram showing an abandoned call attempt between a Calling node (extended T.123) and a Called node (any). The Calling node sends a CR message, and the Called node responds with a DR message. The diagram is labeled T.123(01-07)\_FB09. + +**Figure B.9 – Abandoned call attempt** + +In this model, the calling node shall place a *TRANSPORT-SELECTOR* field in the *CR-TPDU*. If the calling node decided to abandon the call attempt before it receives a *CC-TPDU* or *DR-TPDU*, then it shall send a *DR-TPDU* that contains a variable part. This call model is signalled at the called node when it receives the *DR-TPDU* containing the optional field. + +Reasons for abandoning a connection attempt are a matter left to implementers. These may include an expired time-out on a connection attempt or other local policy violations. + +#### B.7.2 Connection re-establishment + +When a calling node, in response to a *CR-TPDU*, receives a *DR-TPDU* containing the variable part of the PDU, it indicates that the existing network services are not adequate for the set of transport services selected by the calling node. In this case, the calling node shall immediately close the network connection associated with the attempted call. + +After the network connection is closed, the calling node will create a network connection that provides the services (e.g., security) indicated in the variable part of the *DR-TPDU*. Once the new network connection has been established, the full connection procedure for the selected transport protocols will be followed normally. + +One case where reconnection may occur is if the desired parameter lists were too large to send within the 128-octet limit on PDU sizes imposed by X.224. In this case, the calling node should negotiate the use of CNP as the transport protocol to be used. In the subsequent **ConnectRequestPDU**, the 128-octet limit does not apply and desired parameter lists may be included. + +Note that it may be necessary to re-establish the network connection multiple times in order to establish the final transport connection. + +#### B.7.3 Unreliable network service + +If an unreliable data transmission service is to be provided by a transport connection, it shall be negotiated by the same CNP exchange that establishes the final reliable data transmission service. + +The unreliable data service for the T.120 connection shall be considered established only after the reliable data transmission service has been established. + +## **B.8 Extended profiles** + +#### **B.8.1 Reliable transports** + +##### **B.8.1.1 CNP extended profile** + +Figure B.10 defines the CNP extended profile for reliable transport service. This profile is identical to any of the basic or alternative profiles defined in this Recommendation, except that the CNP layer replaces the X.224 class 0 layer. + +![](b44f89b176c971c7dd264c07bfef2c2a_img.jpg) + +| | | +|------------------------------|-----------------------------| +| Transport layer
(layer 4) | CNP | +| Network layer
(layer 3) | Baseline profile
layer 3 | +| Data link layer
(layer 2) | Baseline profile
layer 2 | +| Physical layer
(layer 1) | Baseline profile
layer 1 | + +T.123(01-07)\_FB10 + +**Figure B.10 – Extended profile using CNP for reliable transport service** + +###### *Layer 4* + +- CNP. + +###### *Layer 3* + +- As specified in T.123 basic or alternative profiles. + +###### *Layer 2* + +- As specified in T.123 basic or alternative profiles. + +###### *Layer 1* + +- As specified in T.123 basic or alternative profiles. + +##### **B.8.1.2 SSL/TLS extended profiles** + +Figure B.11 defines the extended profiles for adding security services to T.123 using SSL or TLS. These profiles are identical to the basic, alternative or extended LAN profiles, except that SSL or TLS is added to the transport layer between the TPKT layer and the stream layer. + +![](c1df61cc3717e878a48e530218403403_img.jpg) + +| | | | +|------------------------------|------------------|----------------| +| | X.224
class 0 | CNP | +| Transport layer
(layer 4) | TPKT | TPKT | +| | SSL or TLS | SSL or TLS | +| | Stream | Stream | +| Network layer
(layer 3) | LAN
layer 3 | LAN
layer 3 | +| Data link layer
(layer 2) | LAN
layer 2 | LAN
layer 2 | +| Physical layer
(layer 1) | LAN
layer 1 | LAN
layer 1 | + +T.123(01-07)\_FB11 + +**Figure B.11 – Extended profiles using SSL or TLS for security services** + +###### *Layer 4* + +- X.224 class 0 or CNP for reliable transport service. +- TPKT packet header to delimit TPDU's, as specified in clause 8, Packet header to delimit data units in an octet stream. + +NOTE 1 – TPKT is required because an octet-stream service does not mark where data unit boundaries occur. + +- SSL or TLS. +- Octet-stream transfer with the following characteristics: + - a) Connection-oriented service preserving octet sequence. + - b) Residual error rate low enough to use as a type A network service. + - c) Flow control mechanism to exert back-pressure on a transmitter. + +NOTE 2 – The following specifies a protocol for octet-stream transfer that is a common example of the above: + +- a) RFC 793, Transmission control protocol. +- b) By default, destination port number 1503 per RFC 1700, Assigned numbers, but others may be used. + +###### *Layer 3* + +- Commonly, RFCs 791, 792, 919, 922, 950, 1112, Internet protocol. + +###### *Layer 2* + +- Commonly, [ISO/IEC 8802] logical link control and medium access sublayers. + +###### *Layer 1* + +- Commonly, [ISO/IEC 8802] physical medium. + +##### **B.8.1.3 IPSec extended profiles** + +Figure B.12 defines the extended profiles for adding security services to T.123 using IPSec. These profiles are identical to the basic, alternative or extended LAN profiles, except that IPSec is added to the network layer. + +| | | | +|------------------------------|------------------|----------------| +| Transport layer
(layer 4) | X.224
class 0 | CNP | +| | TPKT | TPKT | +| | Stream | Stream | +| Network layer
(layer 3) | IP +
IPSec | IP +
IPSec | +| Data link layer
(layer 2) | LAN
layer 2 | LAN
layer 2 | +| Physical layer
(layer 1) | LAN
layer 1 | LAN
layer 1 | + +T.123(01-07)\_FB12 + +**Figure B.12 – Extended profiles using IPSec for security services** + +###### *Layer 4* + +- X.224 class 0 or CNP for reliable transport service. +- TPKT packet header to delimit TPDU's, as specified in clause 8, Packet header to delimit data units in an octet stream. + +NOTE 1 – TPKT is required because an octet-stream service does not mark where data unit boundaries occur. + +- Octet-stream transfer with the following characteristics: + - a) Connection-oriented service preserving octet sequence. + - b) Residual error rate low enough to use as a type A network service. + - c) Flow control mechanism to exert back-pressure on a transmitter. + +NOTE 2 – The following specify a layered protocol for octet-stream transfer that is an example of the above: + +- a) RFC 793, Transmission control protocol. +- b) By default, destination port number 1503 per RFC 1700, Assigned numbers, but others may be used. + +###### *Layer 3* + +- Commonly, RFCs 791, 792, 919, 922, 950, 1112, Internet protocol. +- IPSec. + +###### *Layer 2* + +- Commonly, [ISO/IEC 8802] logical link control and medium access sublayers. + +###### *Layer 1* + +- Commonly, [ISO/IEC 8802] physical medium. + +##### **B.8.1.4 X.274 extended profiles** + +Figure B.13 defines the extended profiles for adding security services to T.123 using X.274. These profiles are identical to any of the basic or alternative profiles, or to the extended profile of B.8.1.1, CNP extended profile, except that X.274 is added to the transport layer immediately below the CNP or X.224 class 0 layers. + +| | | | +|------------------------------|-----------------------------|-----------------------------| +| Transport layer
(layer 4) | X.224
class 0 | CNP | +| | X.274 | X.274 | +| Network layer
(layer 3) | Baseline profile
layer 3 | Baseline profile
layer 3 | +| Data link layer
(layer 2) | Baseline profile
layer 2 | Baseline profile
layer 2 | +| Physical layer
(layer 1) | Baseline profile
layer 1 | Baseline profile
layer 1 | + +T.123(01-07)\_FB13 + +**Figure B.13 – Extended profiles using X.274 for security services** + +###### *Layer 4* + +- X.224 class 0 or CNP for reliable transport service. +- X.274 for security service. + +###### *Layer 3* + +- As specified in T.123 basic or alternative profiles. + +###### *Layer 2* + +- As specified in T.123 basic or alternative profiles. + +###### *Layer 1* + +- As specified in T.123 basic or alternative profiles. + +##### **B.8.1.5 GSS-API extended profiles** + +Figure B.14 defines the extended profiles for adding security services to T.123 using the IETF GSS-API security framework. Appendix II provides background on the security framework defined by IETF GSS-API. These profiles are identical to the basic, alternative or extended LAN profiles, except that GSS-API token passing is added to the transport layer above the X.224 class 0 or CNP layers. + +| | | | +|------------------------------|------------------|----------------| +| Transport layer
(layer 4) | GSS-API | GSS-API | +| | X.224
class 0 | CNP | +| | TPKT | TPKT | +| | Stream | Stream | +| Network layer
(layer 3) | LAN
layer 3 | LAN
layer 3 | +| Data link layer
(layer 2) | LAN
layer 2 | LAN
layer 2 | +| Physical layer
(layer 1) | LAN
layer 1 | LAN
layer 1 | + +T.123(01-07)\_FB14 + +**Figure B.14 – Extended profiles using GSS-API for security services** + +###### Layer 4 + +- GSS-API token exchange. +- X.224 class 0 or CNP for reliable transport service. +- TPKT packet header to delimit TPDU, as specified in clause 8, Packet header to delimit data units in an octet stream. + +NOTE 1 – TPKT is required because an octet-stream service does not mark where data unit boundaries occur. + +- Octet-stream transfer with the following characteristics: + - a) Connection-oriented service preserving octet sequence. + - b) Boundary between data units *not* retained as part of the transfer. + - c) Residual error rate low enough to use as a type A network service. + - d) Flow control mechanism to exert back-pressure on a transmitter. + +NOTE 2 – The following specifies a protocol for octet-stream transfer that is a common example of the above: + +- a) RFC 793, Transmission control protocol. +- b) By default, destination port number 1503 per RFC 1700, Assigned numbers, but others may be used. + +###### Layer 3 + +- Commonly, RFCs 791, 792, 919, 922, 950, 1112, Internet protocol. + +###### Layer 2 + +- Commonly, [ISO/IEC 8802] logical link control and medium access sublayers. + +###### Layer 1 + +- Commonly, [ISO/IEC 8802] physical medium. + +#### B.8.2 Unreliable transports + +##### B.8.2.1 Unreliable LAN profile + +Figure B.15 defines the extended profile for adding unreliable transport services to T.123 over LAN connections. Layers 1, 2 and 3 are identical to any of the basic or alternative LAN profiles. + +![](02db3d5ca2c08af069727d3709c4a6fb_img.jpg) + +| | | +|------------------------------|--------------------------| +| | X.234 | +| Transport layer
(layer 4) | X.274
(optional) | +| | Packet +
segmentation | +| Network layer
(layer 3) | LAN
layer 3 | +| Data link layer
(layer 2) | LAN
layer 2 | +| Physical layer
(layer 1) | LAN
layer 1 | + +T.123(01-07)\_FB15 + +**Figure B.15 – Unreliable LAN profile** + +###### Layer 4 + +- X.234, connectionless mode. +- X.274 (optionally negotiated by CNP). +- Unreliable packetized data transfer with segmentation. + +NOTE – User datagram protocol (UDP) is a common example of the above. + +###### Layer 3 + +- As specified in T.123 baseline LAN profiles. + +###### Layer 2 + +- As specified in T.123 baseline LAN profiles. + +###### Layer 1 + +- As specified in T.123 baseline LAN profiles. + +##### B.8.2.2 Unreliable PSTN profile + +See Figure B.16. + +| | Basic or extended
reliable profile | Unreliable
profile | +|------------------------------|---------------------------------------|--------------------------------| +| Transport layer
(layer 4) | X.224 class 0
or
CNP | X.234 | +| | | X.274
(optional) | +| | | Segmentation and
reassembly | +| Network layer
(layer 3) | Null + SCF | | +| Data link layer
(layer 2) | Q.922 | | +| Physical layer
(layer 1) | Start-stop use of V-series DCE | | + +T.123(01-07)\_FB16 + +**Figure B.16 – Unreliable PSTN profile** + +###### Layer 4 + +- X.234, connectionless mode. +- X.274 (optional, negotiated via CNP). +- Unreliable segmentation and reassembly protocol as defined in clause B.10, Unreliable segmentation and reassembly protocol. + +###### Layer 3 + +- As specified in T.123 basic PSTN profile. + +###### Layer 2 + +- Q.922, using unnumbered information (UI) + +###### Layer 1 + +- As specified in T.123 basic PSTN profile. + +## **B.9 Connection negotiation protocol (CNP)** + +### **B.9.1 Overview** + +The PDUs defined in this protocol are based on their X.224 class 0 counterparts. Both X.224 and CNP provide connect request, connect confirm, disconnect request, data, and error TPDUs. In addition, CNP provides a **NonStandardPDU** for protocol extensibility. + +The CNP TPDUs defined in this annex shall not be used outside the context of T.120 communications. + +### **B.9.2 Structure of CNP TPDUs** + +All CNP transport protocol data units (TPDUs) shall contain a whole number of octets. When consecutive octets are used to represent a binary number, the lower octet number shall have the most significant value. CNP transport entities shall respect bit and octet ordering conventions, thus allowing communication to take place. + +Figure B.17 illustrates the structure of CNP TPDUs. + +![Diagram of CNP general TPDU structure showing octets 1 to n. Octet 1 contains LI, Octet 2 contains TPDU code, and Octets 3 to n contain the Data field. A double-headed arrow labeled 'Header' spans octets 1 and 2. Reference: T.123(01-07)_FB17](adc59ed6840bcb2d392ea323abfccedc_img.jpg) + +The diagram illustrates the structure of a CNP TPDU across multiple octets. Octet 1 contains the Length Indicator (LI). Octet 2 contains the TPDU code. Octets 3 through n contain the Data field. A double-headed arrow labeled 'Header' spans octets 1 and 2. The reference T.123(01-07)\_FB17 is noted at the bottom right. + +Diagram of CNP general TPDU structure showing octets 1 to n. Octet 1 contains LI, Octet 2 contains TPDU code, and Octets 3 to n contain the Data field. A double-headed arrow labeled 'Header' spans octets 1 and 2. Reference: T.123(01-07)\_FB17 + +**Figure B.17 – CNP general TPDU structure** + +CNP TPDUs shall contain, in the following order: + +- The header, comprising: + - a) the length indicator (LI) field; + - b) the TPDU code. +- The data field. + +CNP TPDUs are divided into two categories: control and data. The values of the header fields for each of these TPDU types are given in Table B.1. The data field of control TPDUs shall contain an ASN.1 structure as defined in clause B.9.3, Control TPDUs. The data field of data TPDUs shall contain octet structures as defined in clause B.9.4, Data TPDUs. + +**Table B.1 – CNP TPDU field values** + +| TPDU | Type | LI | TPDU code | Data field | +|--------------------|---------|-----------|-----------|------------------| +| Connect request | Control | 0000 0001 | 0100 0111 | ASN.1 | +| Connect confirm | Control | 0000 0001 | 0100 0111 | ASN.1 | +| Disconnect request | Control | 0000 0001 | 0100 0111 | ASN.1 | +| Error | Control | 0000 0001 | 0100 0111 | ASN.1 | +| Nonstandard | Control | 0000 0001 | 0100 0111 | ASN.1 | +| Data | Data | 0000 0001 | 0100 0110 | Octet structures | + +#### **B.9.3 Control TPDUs** + +The structure of a CNP control TPDU is illustrated in Figure B.18. + +![Diagram of CNP control TPDU structure showing octets 1 to n. Octet 1 is LI, octet 2 is TPDU code, and octets 3 to n are ASN.1. The first two octets form the Header, and the rest form the Data field.](4162c218fc7881cd90fc9574e07d2327_img.jpg) + +The diagram illustrates the structure of a CNP control TPDU. It is represented as a horizontal bar divided into three sections. The first section, labeled 'LI', occupies octet 1. The second section, labeled 'TPDU code', occupies octet 2. The third section, labeled 'ASN.1', occupies octets 3 through n. Above the bar, the octets are numbered 1, 2, 3, ..., n. Below the bar, a double-headed arrow spans the first two octets and is labeled 'Header'. Another double-headed arrow spans from octet 3 to octet n and is labeled 'Data field'. The text 'T.123(01-07)\_FB18' is located at the bottom right of the diagram. + +Diagram of CNP control TPDU structure showing octets 1 to n. Octet 1 is LI, octet 2 is TPDU code, and octets 3 to n are ASN.1. The first two octets form the Header, and the rest form the Data field. + +**Figure B.18 – CNP control TPDU structure** + +All CNP control TPDUs shall use the following octet values for header fields: + +- LI 0000 0001 +- TPDU code 0100 0111 + +The data field for these TPDUs shall consist of a single ASN.1 encoded **CNPControlPDU** structure, as defined in clause B.9.6, ASN.1 definition. Descriptions of this structure's components are given below. + +##### B.9.3.1 Common information elements + +Portions of the ASN.1 for CNP were derived from other sources, as described below: + +- 1) **Priority** was derived from Annex A of [ITU-T T.125]. +- 2) **H221NonStandard**, **NonStandardIdentifier**, **NonStandardParameter** and **AliasAddress** (as well as its required sub-types such as **TransportAddress** and **PartyNumber**) were derived from [ITU-T H.225.0]. + +**ReliableTransportProtocol**: specifies a single, reliable transport protocol and the conditions under which it may be used. This structure contains the following elements: + +- **type**: specifies CNP, X.224, MAP or a non-standard protocol. +- **maxTPDUSize**: the maximum supported size (in octets) of a single TPDU, including the header. +- **nonStandardParameters**: information not defined in this Recommendation. (e.g., proprietary data). + +**ReliableSecurityProtocol**: specifies a single security protocol for use with reliable data transfer. This value will specify one of the following: + +- None. +- TLS. +- SSL. +- IPSec (with IKE or manual key management). +- X.274 (with or without SA ID support). +- GSS-API. +- Physical1. +- A non-standard protocol. + +1 Indicates that a physically secure connection exists between the connecting nodes for reliable communications. Determining whether or not this condition exists is outside the scope of this Recommendation and is a matter for implementers. Note that this condition must be both proposed and accepted during connection establishment to be considered in effect. + +**UnreliableTransportProtocol:** specifies a single, unreliable transport protocol and the conditions under which it may be used. This structure contains the following elements: + +- **type:** Specifies either X.234 or a non-standard protocol. +- **maxTPDUSize:** The maximum supported size of a single TPDU, including the header. +- **sourceAddress:** Network address to be used in conjunction with this protocol. This is the address that the sender of the **UnreliableTransportProtocol** structure will use to receive unreliable data for the connection being negotiated. +- **sourceTSAP:** TSAP to be used in conjunction with this protocol. The sender of the **UnreliableTransportProtocol** structure may use this identifier to distinguish between data for this connection and data from other connections when both are received at the same network address. +- **nonStandardParameters:** Information not defined in this Recommendation (e.g., proprietary data). + +**UnreliableSecurityProtocol:** specifies a single security protocol for use with unreliable data transfer. This value will specify one of the following: + +- None. +- IPsec (with IKE or manual key management). +- X.274 (with or without SA ID support). +- Physical2. +- A non-standard protocol. + +##### B.9.3.2 Connect request + +**protocolIdentifier:** The version of the CNP protocol supported by the caller. + +**reconnectRequested:** When a called node receives a connect request with this field set to *true*, it shall respond with a disconnect request. This field should be set *true* by the calling node in an X.224 encapsulated connect request when the full connection information will not fit within the size constraints of a *CR-TPDU*. In this case, CNP should be negotiated for reconnection so that the complete set of connection information may be exchanged. + +**Priority:** The priority of the data to be sent over this transport connection. If omitted, this connection shall be used to transfer all data priorities. + +**reliableTransportProtocols:** A list of the reliable transport protocols supported by the calling node, in order of preference. If omitted, the existing protocol shall continue to be used. + +**reliableSecurityProtocols:** A list of the reliable security protocols supported by the calling node, in order of preference. Omitting this field indicates that the caller does not support reliable security protocols. + +**unreliableTransportProtocols:** A list of the unreliable transport protocols supported by the calling node, in order of preference. Omitting this field indicates that the caller does not support unreliable data transfer. + +**unreliableSecurityProtocols:** A list of the unreliable security protocols supported by the calling node, in order of preference. Omitting this field indicates that the caller does not support unreliable security protocols. + +**destinationAddress:** A sequential list of transport aliases for establishing the connection. + +**nonStandardParameters:** Information not defined in this Recommendation (e.g., proprietary data). + +--- + +2 See Footnote 1. + +##### B.9.3.3 Connect confirm + +**protocolIdentifier:** The version of the CNP protocol to be used by this transport connection. + +**reliableTransportProtocol:** The reliable transport protocol to be used by this transport connection. If omitted, the current protocol (i.e., X.224 or CNP) shall continue to be used. + +**reliableSecurityProtocol:** The reliable security protocol to be used by this transport connection. Omitting this field indicates that a reliable security protocol will not be used by this connection. + +**unreliableTransportProtocol:** The unreliable security protocol to be used by this transport connection. Omitting this field indicates that an unreliable data transfer will not be supported by this connection. + +**unreliableSecurityProtocol:** The unreliable security protocol to be used by this transport connection. Omitting this field indicates that an unreliable security protocol will not be used by this connection. + +**nonStandardParameters:** Information not defined in this Recommendation (e.g., proprietary data). + +##### B.9.3.4 Disconnect request + +**disconnectReason:** Reason for the disconnection. This field may have the following values: + +- **unacceptableVersion:** In response to a connect request, indicates that the version of CNP used in the connect request is not acceptable. +- **incompatibleParameters:** In response to a connect request, indicates that no acceptable common set of valid connection parameters was found. +- **securityDenied:** Indicates that local security policies do not permit the connection to be established3 or to continue operation if already established. +- **destinationUnreachable:** In response to a connect request, indicates that the called node cannot complete the connection as specified by the caller. +- **userRejected:** In response to a connect request, indicates that the connection attempt was rejected at a level above the transport. +- **userInitiated:** After a connection has been established, indicates that the disconnection was requested at a level above the transport. +- **protocolError:** Indicates that a fatal error occurred while processing a TPDU. +- **unspecifiedFailure:** A non-specific error occurred. +- **routeToAlternate:** In response to a connect request, indicates that the connection is desired, but that the caller should attempt to reconnect using the information in the remaining fields. +- **nonStandardDisconnectReason:** A reason not defined in this Recommendation (e.g., a proprietary reason). + +**reliableTransportProtocol:** The reliable transport protocol to be used after reconnection. If omitted, X.224 shall continue to be used. This field is valid only if **disconnectReason** was **routeToAlternate**. + +**reliableSecurityProtocol:** The reliable security protocol to be used after reconnection. Omitting this field indicates that a reliable security protocol will not be used after reconnection. This field is valid only if **disconnectReason** was **routeToAlternate**. + +--- + +3 It is acceptable to issue a *DR-TPDU* without the optional field (as described in clause B.7.1.5, Connection refusal) if the called node does not wish to disclose the reason for rejecting a connection attempt. + +**unreliableTransportProtocol:** The unreliable transport protocol to be used after reconnection. Omitting this field indicates that an unreliable data transfer will not be supported after reconnection. This field is valid only if **disconnectReason** was **routeToAlternate**. + +**unreliableSecurityProtocol:** The unreliable security protocol to be used after reconnection. Omitting this field indicates that an unreliable security protocol will not be used after reconnection. This field is valid only if **disconnectReason** was **routeToAlternate**. + +**destinationAddress:** A sequential list of transport aliases to be used by the caller for establishing the new connection. This field is valid only if **disconnectReason** was **routeToAlternate**. + +**nonStandardParameters:** Information not defined in this Recommendation (e.g., proprietary data). + +##### B.9.3.5 Error + +**rejectCause:** reason the PDU was rejected. This field may have the following values: + +- **unrecognizedPDU:** Indicates that the PDU did not decode into a recognizable form. +- **invalidParameter:** Indicates that the PDU contained one or more invalid parameter values. +- **causeUnspecified:** A non-specific cause. +- **nonStandardRejectCause:** A cause not defined in this Recommendation (e.g., a proprietary cause). + +**rejectedPDU:** The rejected PDU. + +**nonStandardParameters:** Information not defined in this Recommendation (e.g., proprietary data). + +##### B.9.3.6 Nonstandard PDU + +**nonStandardParameters:** Information not defined in this Recommendation (e.g., proprietary data). + +#### B.9.4 Data TPDUs + +##### B.9.4.1 Structure + +The structure of a CNP data TPDU is illustrated in Figure B.19. + +![Diagram of CNP data TPDU structure showing octets 1, 2, 3, ..., n. Octet 1 is LI, Octet 2 is TPDU code, Octet 3 is Data segment, and Octet n is Data segment. The first two octets form the Header, and the rest form the Data field.](b32d1cc64b2d9f0935ddac4ebca86a32_img.jpg) + +The diagram illustrates the structure of a CNP data TPDU. It is represented as a horizontal sequence of octets. The first octet (labeled '1') contains 'LI'. The second octet (labeled '2') contains 'TPDU code'. The third octet (labeled '3') contains 'Data segment'. An ellipsis '...' follows, and the final octet (labeled 'n') contains 'Data segment'. A double-headed arrow below the first two octets is labeled 'Header'. A double-headed arrow below the remaining octets (from octet 3 to octet n) is labeled 'Data field'. Above the diagram, the word 'Octets' is centered. Below the diagram, the identifier 'T.123(01-07)\_FB19' is present. + +Diagram of CNP data TPDU structure showing octets 1, 2, 3, ..., n. Octet 1 is LI, Octet 2 is TPDU code, Octet 3 is Data segment, and Octet n is Data segment. The first two octets form the Header, and the rest form the Data field. + +**Figure B.19 – CNP data TPDU structure** + +All CNP data TPDUs shall use the following octet values for header fields: + +- LI                0000 0001 +- TPDU Code    0100 0110 + +The data field for a data TPDU shall consist of one or more data segments, as described below. + +##### B.9.4.2 Data segments + +The structure of a data segment is shown in Figure B.20. + +![Diagram of Data segment structure showing octets 1 to n. Octet 1 is Field code, octets 2-3 are Length, and octets 4-n are User data. A double-headed arrow under octets 1-3 is labeled 'Field header'. Reference: T.123(01-07)_FB20](cbab05075b3d7dc0d27c4cbb0c914a94_img.jpg) + +| | | | | | | +|-----------------------------------------------------------------------------------------------|--------|---|-----------|-----|---| +| 1 | 2 | 3 | 4 | ... | n | +| Field
code | Length | | User data | | | +|
| | | | | | +|
| | | | | | + +T.123(01-07)\_FB20 + +Diagram of Data segment structure showing octets 1 to n. Octet 1 is Field code, octets 2-3 are Length, and octets 4-n are User data. A double-headed arrow under octets 1-3 is labeled 'Field header'. Reference: T.123(01-07)\_FB20 + +**Figure B.20 – Data segment structure** + +A data segment is an octet structure composed of a fixed length field header and variable number of user data octets. + +The following parameters are required in a data segment: + +- a)     **Field code**                     **(octet 1)** +         Parameter length:     one octet +         Parameter value:     000y zzzz +                                   y indicates whether this is the final segment of a user data packet. +                                   Setting y to a value of 1 indicates a final segment. +                                   zzzz is a binary value equal to the MCS priority of the data. +- b)     **Length**                         **(octets 2 and 3)** +         Parameter length:     two octets +         Parameter value:     a binary value indicating the number of user data octets, with a +                                   maximum value of 65530. +- c)     **User data**                     **(octets 4 through length + 3)** +         Parameter length:     **Length** octets +         Parameter value:     user data octets + +#### **B.9.5 Using CNP within X.224** + +##### **B.9.5.1 Encapsulating TPDUs** + +During the connection procedures described in clause B.7.1, Initial connection establishment, X.224 TPDUs shall be used to encapsulate CNP TPDUs as follows: + +- The *TRANSPORT-SELECTOR* field in a *CR-TPDU* shall contain a **Connect Request TPDU**. +- The *TRANSPORT-SELECTOR* field in a *CC-TPDU* shall contain a **Connect Confirm TPDU**. +- The variable part of a *DR-TPDU* shall contain either a **Disconnect Request TPDU** or an **Error TPDU**. + +##### **B.9.5.2 Reconnection procedures** + +- If the reliable transport protocol indicated in a **Connect Confirm TPDU** is X.224, either side may immediately send a *DATA (DT) TPDU*, or any other valid X.224 PDU. +- If the reliable transport protocol indicated in a **Connect Confirm TPDU** is CNP, either side may immediately send a **Data TPDU**, or any other valid CNP PDU. +- If the reliable transport protocol indicated in a **Connect Confirm TPDU** is not X.224 or CNP, both the calling and called nodes shall follow the complete connection establishment procedure for the selected protocol (i.e., the caller will issue the appropriate connect request PDU). + +#### B.9.6 ASN.1 definition + +``` +-- +-- ASN.1 Definition for CNP Control PDUs +-- + +CNP-PROTOCOL {itu-t (0) recommendation (0) t (20) 123 annexb (2) 1} + +DEFINITIONS AUTOMATIC TAGS ::= +BEGIN + +-- +-- Imported Definitions +-- + +IMPORTS + NonStandardParameter, + TransportAddress, + AliasAddress + FROM H323-MESSAGES + -- H.225.0 Version 2 + -- {itu-t (0) recommendation (0) h (8) 2250 version (0) 2} + + Priority + FROM MAP-PROTOCOL; + -- T.125 Annex A Version 1 + +ProtocolIdentifier ::= OBJECT IDENTIFIER + -- shall be set to + -- {itu-t (0) recommendation (0) t (20) 123 annexb (2) 1} + +-- +-- Service Negotiation Types +-- + +TPDUSize ::= INTEGER (128..65535) + +ReliableTransportProtocolType ::= CHOICE +{ + cnp NULL, + x224 NULL, + map NULL, + nonStandardTransportProtocol NonStandardParameter, + ... +} + +ReliableTransportProtocol ::= SEQUENCE +{ + type ReliableTransportProtocolType, + maxTPDUSize TPDUSize, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + ... +} + +ReliableSecurityProtocol ::= CHOICE +{ + none NULL, + tls NULL, + ssl NULL, + ipsecIKEKeyManagement NULL, + ipsecManualKeyManagement NULL, + x274WithoutSAID NULL, + x274WithSAID X274WithSAIDInfo, + gssApi NULL, + physical NULL, +} +``` + +``` + + nonStandardSecurityProtocol NonStandardParameter, + ... + } + +UnreliableTransportProtocolType ::= CHOICE +{ + x234 NULL, + nonStandardTransportProtocol NonStandardParameter, + ... +} + +UnreliableTransportProtocol ::= SEQUENCE +{ + type UnreliableTransportProtocolType, + maxTPDUSize TPDUSize, + sourceAddress TransportAddress, + sourceTSAP OCTET STRING OPTIONAL, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + ... +} + +UnreliableSecurityProtocol ::= CHOICE +{ + none NULL, + ipsecIKEKeyManagement NULL, + ipsecManualKeyManagement NULL, + x274WithoutSAID NULL, + x274WithSAID X274WithSAIDInfo, + physical NULL, + nonStandardSecurityProtocol NonStandardParameter, + ... +} + +X274WithSAIDInfo ::= SEQUENCE +{ + localSAID OCTET STRING, + peerSAID OCTET STRING, + ... +} + +-- +-- CNP Control PDU Types +-- + +ConnectRequestPDU ::= SEQUENCE +{ + protocolIdentifier ProtocolIdentifier, + reconnectRequested BOOLEAN, + priority Priority OPTIONAL, + reliableTransportProtocols SEQUENCE OF ReliableTransportProtocol + OPTIONAL, + reliableSecurityProtocols SEQUENCE OF ReliableSecurityProtocol + OPTIONAL, + unreliableTransportProtocols SEQUENCE OF UnreliableTransportProtocol + OPTIONAL, + unreliableSecurityProtocols SEQUENCE OF UnreliableSecurityProtocol + OPTIONAL, + destinationAddress SEQUENCE OF AliasAddress OPTIONAL, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + ... +} + +ConnectConfirmPDU ::= SEQUENCE +{ + +``` + +| | | +|-----------------------------------|--------------------------------------------| +| protocolIdentifier | ProtocolIdentifier, | +| reliableTransportProtocol | ReliableTransportProtocol OPTIONAL, | +| reliableSecurityProtocol | ReliableSecurityProtocol OPTIONAL, | +| unreliableTransportProtocol | UnreliableTransportProtocol OPTIONAL, | +| unreliableSecurityProtocol | UnreliableSecurityProtocol OPTIONAL, | +| nonStandardParameters | SEQUENCE OF NonStandardParameter OPTIONAL, | +| ... | | +| } | | +| DisconnectReason ::= CHOICE | | +| { | | +| unacceptableVersion | NULL, | +| incompatibleParameters | NULL, | +| securityDenied | NULL, | +| destinationUnreachable | NULL, | +| userRejected | NULL, | +| userInitiated | NULL, | +| protocolError | NULL, | +| unspecifiedFailure | NULL, | +| routeToAlternate | NULL, | +| nonStandardDisconnectReason | NonStandardParameter, | +| ... | | +| } | | +| DisconnectRequestPDU ::= SEQUENCE | | +| { | | +| disconnectReason | DisconnectReason, | +| reliableTransportProtocol | ReliableTransportProtocol OPTIONAL, | +| reliableSecurityProtocol | ReliableSecurityProtocol OPTIONAL, | +| unreliableTransportProtocol | UnreliableTransportProtocol OPTIONAL, | +| unreliableSecurityProtocol | UnreliableSecurityProtocol OPTIONAL, | +| destinationAddress | SEQUENCE OF AliasAddress OPTIONAL, | +| nonStandardParameters | SEQUENCE OF NonStandardParameter OPTIONAL, | +| ... | | +| } | | +| RejectCause ::= CHOICE | | +| { | | +| unrecognizedPDU | NULL, | +| invalidParameter | NULL, | +| causeUnspecified | NULL, | +| nonStandardRejectCause | NonStandardParameter, | +| ... | | +| } | | +| ErrorPDU ::= SEQUENCE | | +| { | | +| rejectCause | RejectCause, | +| rejectedPDU | OCTET STRING, | +| nonStandardParameters | SEQUENCE OF NonStandardParameter OPTIONAL, | +| ... | | +| } | | +| NonStandardPDU ::= SEQUENCE | | +| { | | +| nonStandardParameters | SEQUENCE OF NonStandardParameter OPTIONAL, | +| ... | | +| } | | +| CNPControlPDU ::= CHOICE | | +| { | | +| connectRequest | ConnectRequestPDU, | +| connectConfirm | ConnectConfirmPDU, | +| disconnectRequest | DisconnectRequestPDU, | +| error | ErrorPDU, | + +``` + +nonStandardCNPPDU +... +} +END + +``` + +## B.10 Unreliable segmentation and reassembly protocol + +### B.10.1 Overview + +This protocol was designed for use over unreliable, packet-based connections and is based on the SAR functions described in RFC 791, Internet protocol. The protocol defines a single PDU that will allow a sender to segment a TSDU into one or more TPDUs small enough to be transmitted by a size-limited lower network layer. At the receiver, the TPDU segments can be reassembled to provide the complete, original TSDU to a higher network layer. Although this protocol does not assume ordered or guaranteed delivery of packets, it does assume that received packets are uncorrupted. + +### B.10.2 Structure of unreliable SAR TPDUs + +All unreliable SAR transport protocol data units (TPDUs) shall contain a whole number of octets. When consecutive octets are used to represent a binary number, the lower octet number shall have the most significant value. Unreliable SAR transport entities shall respect bit and octet ordering conventions, thus allowing communication to take place. + +Note that the issues involved in re-ordering out-of-order fragments by the receiver are a matter left for implementers. + +The structure of an unreliable SAR TPDU is shown in Figure B.21. + +![](077f85b82901283b4657fd2b45fc0294_img.jpg) + +| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | Octet | +|-------------------------------------------|---|-----------------------|---|---|---|---|---|-------| +| LI | | | | | | | | 1 | +| TPDU code | | | | | | | | 2 | +| Flags | | Fragment offset (MSB) | | | | | | 3 | +| Fragment offset (LSB) | | | | | | | | 4 | +| Identification | | | | | | | | 5 | +| | | | | | | | | 6 | +| Total length
(conditionally mandatory) | | | | | | | | 7 | +| | | | | | | | | 8 | +| User data | | | | | | | | . | +| | | | | | | | | . | +| | | | | | | | | . | +| | | | | | | | | n | + +T.123(01-07)\_FB21 + +**Figure B.21 – Unreliable SAR TPDU structure** + +Unreliable SAR TPDUs shall contain, in the following order: + +- The header, comprising: + - a) The length indicator (LI) field; + - b) The TPDU code; + - c) The flags field; + - d) The fragment offset field; + - e) The identification field; + - f) Conditionally, a total length field. +- The user data field. + +##### **B.10.2.1 Length indicator field** + +Field length: one octet + +Field value: a binary value indicating the header length in octets, including optional fields, but excluding the length indicator field and user data. + +##### **B.10.2.2 TPDU code** + +Field length: one octet + +Field value: the binary value: 0100 0110 + +##### **B.10.2.3 Flags field** + +Field length: 3 bits + +Field value: Bit 8: reserved, must be set to zero + +Bit 7: reserved, must be set to zero + +Bit 6: more fragments (MF) flag + +0 = last fragment in TSDU + +1 = more TSDU fragments to follow + +##### **B.10.2.4 Fragment Offset field** + +Field length: 13 bits + +Field value: a binary value indicating where in the reassembled TSDU this fragment belongs. The fragment offset is measured in units of 8 octets. The offset of the first fragment is zero. Bit 5 of octet 3 represents the most significant bit of this value. + +##### **B.10.2.5 Identification field** + +Field length: two octets + +Field value: a binary value identifying common fragments of a datagram. This unsigned value shall be zero for the first TSDU sent over a connection and incremented by 1 for each succeeding TSDU. + +##### **B.10.2.6 Total Length field (conditionally mandatory)** + +Field length: two octets + +Field value: a binary value indicating the total length of the TSDU, measured in octets. This value shall be included with the first fragment of any TSDU segmented into multiple fragments. The value may be included with any or all other fragments. + +#### **B.10.2.7 User Data field** + +Field length: variable + +Field value: user data octets + +# **Bibliography** + +~~———— IETF RFC 2078 (January 1997), *Generic Security Service Application Program Interface*.~~ + +# Appendix I + +## Multimedia conference call set-up in the ISDN + +(This appendix does not form an integral part of this Recommendation) + +### I.1 Introduction + +Multimedia conference (MMC) terminals, currently under standardization in ITU-T, are intended to operate within the ISDN. However, various terminals of different types such as telephone, facsimile group 4, videophones and teleconference systems are also connected to the ISDN. + +The following scenarios are derived from [ITU-T Q.931], which provides more information and describes other possibilities. Attention should be paid to the coding of information elements for BC, LLC and HLC, because they are important for interworking. + +Table I.1 suggests values that may be used in a SETUP message. The called side terminal should also accept other values of the information elements for BC, LLC and HLC. Alternative settings include unrestricted digital information with tones and announcements (UDI-TA), rate adaptation to 56 kbit/s for restricted networks, double BC/HLC and absence of LLC. When HLC is used, call acceptance should be configured by the user to allow either telephony 7 kHz, video telephony, or telephony 3.1 kHz. + +**Table I.1 – Parameter settings originated in SETUP message** + +| Information element | BC | LLC | HLC | +|--------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------|----------------------------------|------------------| +| Information transfer capability | Unrestricted digital information | Unrestricted digital information | | +| Transfer mode | Circuit | Circuit | | +| Information transfer rate | 64 kbit/s | 64 kbit/s | | +| User information layer 1 protocol | | H.221 | | +| High layer characteristics identification | | | AC a) | +| a) AC audiographic teleconference.
VC (videoconferencing), VP (videophone) and AV (audiovisual) are acceptable in the case of the called side. | | | | + +### I.2 Basic requirements + +The following conditions are basic requirements: + +- 1) An MMC terminal has the ISDN I/F function inside it and directly connects to the ISDN at a S(T) point. +- 2) An MMC terminal desires to intercommunicate with the following terminals: + - a) MMC terminal; + - b) Videophone, teleconference with H.221 frame structure supported. + +Items a) and b) mentioned above will together be called AV (audiovisual) terminals in the following. + +Intercommunication between MMC terminals and telephones is the fundamental demand. However, each side uses different ISDN services (e.g., MMC: unrestricted digital + +information, telephone: speech); therefore, this type of intercommunication would be difficult, without using special sequences, as shown in Figures I.2 and I.3. + +- 3) This description is for the point-to-point connection only. The outline of the sequence is shown in Figure I.1. + +![Sequence diagram showing communication establishment for MMC terminals between two sets of MLP, H.221, and Dch layers.](3ce04f1c7128814978c6b34d654a25cc_img.jpg) + +``` + +sequenceDiagram + participant L1 as MLP + participant L2 as H.221 + participant L3 as Dch + participant R1 as Dch + participant R2 as H.221 + participant R3 as MLP + + L3->>R3: SETUP + L3-->>R3: BC: (Octet 3) unrestricted digital information + L3-->>R3: LLC: (Octet 3) unrestricted digital information + L3-->>R3: (Octet 5) ITU-T Rec. H.221 + L3-->>R3: HLC: (Octet 4) Audiographic teleconference + R3-->>L3: CONNECT + L2-->>R2: Establishment of frame alignment based on H.221 + L2-->>R2: Indication of the capability + L2-->>R2: Indication of the capability + L2-->>R2: Indication of the communication mode + L2-->>R2: Indication of the communication mode + L1-->>R3: Establishment of MLP path + L1-->>R3: Establishment of data link connection + L1-->>R3: Establishment of layer 4 + L1-->>R3: MCS connection by T.125 + L1-->>R3: (communication based on the application) + +``` + +The diagram illustrates the communication establishment sequence for MMC terminals. It shows two sets of layers: MLP, H.221, and Dch on the left, and Dch, H.221, and MLP on the right. The sequence of operations is as follows: + +- SETUP**: A message is sent from the left Dch layer to the right MLP layer. This message contains: + - BC: (Octet 3) unrestricted digital information + - LLC: (Octet 3) unrestricted digital information + - (Octet 5) ITU-T Rec. H.221 + - HLC: (Octet 4) Audiographic teleconference +- CONNECT**: A response message is sent from the right Dch layer back to the left Dch layer. +- Establishment of frame alignment based on H.221**: A message is sent from the left H.221 layer to the right H.221 layer. +- Indication of the capability**: Two messages are sent from the left H.221 layer to the right H.221 layer. +- Indication of the communication mode**: Two messages are sent from the left H.221 layer to the right H.221 layer. +- Establishment of MLP path**: A message is sent from the left MLP layer to the right MLP layer. +- Establishment of data link connection**: A message is sent from the left MLP layer to the right MLP layer. +- Establishment of layer 4**: A message is sent from the left MLP layer to the right MLP layer. +- MCS connection by T.125**: A message is sent from the left MLP layer to the right MLP layer. +- (communication based on the application)**: A final message is sent from the left MLP layer to the right MLP layer. + +Sequence diagram showing communication establishment for MMC terminals between two sets of MLP, H.221, and Dch layers. + +T.123(01-07)\_F1.01 + +**Figure I.1 – Communication establishment sequence for MMC terminals** + +![Sequence diagram for call from MMC terminal to ISDN telephone. The diagram shows three vertical lifelines: MMC Terminal, ISDN, and ISDN telephone. The sequence of events is: 1. SETUP from MMC Terminal to ISDN, containing BC: (Octet 3) unrestricted digital information, LLC: (Octet 3) unrestricted digital information (Octet 5) ITU-T Rec. H.221, and HLC: (Octet 4) audiographic teleconference. 2. DISCONNECT from ISDN to MMC Terminal. 3. RELEASE COMP from ISDN to ISDN telephone. 4. SETUP from MMC Terminal to ISDN, containing BC: (Octet 3) speech (Octet 5) ITU-T Rec. G.711, LLC: (Octet 3) speech (Octet 5) speech, and HLC: (Octet 4) ITU-T Rec. G.711. 5. CONNECT from ISDN to ISDN telephone.](fd8f5da2b60cdca94896f3cde8ee81f0_img.jpg) + +Sequence diagram for call from MMC terminal to ISDN telephone: + +- SETUP** (from MMC Terminal to ISDN): + - BC: (Octet 3) unrestricted digital information + - LLC: (Octet 3) unrestricted digital information (Octet 5) ITU-T Rec. H.221 + - HLC: (Octet 4) audiographic teleconference +- DISCONNECT** (from ISDN to MMC Terminal) +- RELEASE COMP** (from ISDN to ISDN telephone) +- SETUP** (from MMC Terminal to ISDN): + - BC: (Octet 3) speech (Octet 5) ITU-T Rec. G.711 + - LLC: (Octet 3) speech (Octet 5) speech + - HLC: (Octet 4) ITU-T Rec. G.711 +- CONNECT** (from ISDN to ISDN telephone) + +Sequence diagram for call from MMC terminal to ISDN telephone. The diagram shows three vertical lifelines: MMC Terminal, ISDN, and ISDN telephone. The sequence of events is: 1. SETUP from MMC Terminal to ISDN, containing BC: (Octet 3) unrestricted digital information, LLC: (Octet 3) unrestricted digital information (Octet 5) ITU-T Rec. H.221, and HLC: (Octet 4) audiographic teleconference. 2. DISCONNECT from ISDN to MMC Terminal. 3. RELEASE COMP from ISDN to ISDN telephone. 4. SETUP from MMC Terminal to ISDN, containing BC: (Octet 3) speech (Octet 5) ITU-T Rec. G.711, LLC: (Octet 3) speech (Octet 5) speech, and HLC: (Octet 4) ITU-T Rec. G.711. 5. CONNECT from ISDN to ISDN telephone. + +(Communication by means of speech service) + +#### **1) Call from MMC terminal to ISDN telephone** + +![Sequence diagram for call from ISDN telephone to MMC terminal. The diagram shows three vertical lifelines: MMC terminal, ISDN, and ISDN telephone. The sequence of events is: 1. SETUP from ISDN telephone to ISDN, containing BC: (Octet 3) speech (Octet 5) ITU-T Rec. G.711, LLC: (Octet 3) speech (Octet 5) ITU-T Rec. G.711, and HLC: (Octet 4) telephony. 2. CONNECT from ISDN to MMC terminal.](fcc757566216206ceddbd6c775e8db02_img.jpg) + +Sequence diagram for call from ISDN telephone to MMC terminal: + +- SETUP** (from ISDN telephone to ISDN): + - BC: (Octet 3) speech (Octet 5) ITU-T Rec. G.711 + - LLC: (Octet 3) speech (Octet 5) ITU-T Rec. G.711 + - HLC: (Octet 4) telephony +- CONNECT** (from ISDN to MMC terminal) + +Sequence diagram for call from ISDN telephone to MMC terminal. The diagram shows three vertical lifelines: MMC terminal, ISDN, and ISDN telephone. The sequence of events is: 1. SETUP from ISDN telephone to ISDN, containing BC: (Octet 3) speech (Octet 5) ITU-T Rec. G.711, LLC: (Octet 3) speech (Octet 5) ITU-T Rec. G.711, and HLC: (Octet 4) telephony. 2. CONNECT from ISDN to MMC terminal. + +(Communication by means of speech service) + +T.123(01-07)\_FI.02 + +#### **2) Call from ISDN telephone to MMC terminal** + +**Figure I.2 – Intercommunication sequences for MMC terminal and ISDN telephone** + +![Sequence diagram for call from MMC terminal to analogue telephone via ISDN/PSTN.](1b23b78336d8bd286c653cbdb38428dd_img.jpg) + +Sequence diagram illustrating the call setup and connection for communication by means of speech service from an MMC terminal to an analogue telephone via ISDN/PSTN. + +**Participants:** MMC terminal, ISDN/PSTN, Analogue telephone. + +**Sequence of Events:** + +- Setup Phase:** The MMC terminal sends a **SETUP** message to the ISDN/PSTN. The message contains: + - BC: (Octet 3) unrestricted digital information + - LLC: (Octet 3) unrestricted digital information (Octet 5) ITU-T Rec. H.221 + - HLC: (Octet 4) audiographic teleconference +- Release Phase:** The ISDN/PSTN sends a **RELEASE COMPLETE** message back to the MMC terminal. +- Call Phase:** The MMC terminal sends a **SETUP** message to the ISDN/PSTN. The message contains: + - BC: (Octet 3) speech (Octet 5) ITU-T Rec. G.711 + - LLC: (Octet 3) speech (Octet 5) ITU-T Rec. G.711 + - HLC: (Octet 4) telephony +- Connect Phase:** The ISDN/PSTN sends a **CONNECT** message back to the MMC terminal. +- Call and Response:** The ISDN/PSTN sends a **(CALL)** message to the Analogue telephone, and the Analogue telephone sends a **(RESPONSE)** message back to the ISDN/PSTN. + +Sequence diagram for call from MMC terminal to analogue telephone via ISDN/PSTN. + +(Communication by means of speech service) + +#### 3) Call from MMC terminal to analogue telephone + +![Sequence diagram for call from analogue telephone to MMC terminal via ISDN/PSTN.](5801c19431e76330430e92a598cc7a16_img.jpg) + +Sequence diagram illustrating the call setup and connection for communication by means of speech service from an analogue telephone to an MMC terminal via ISDN/PSTN. + +**Participants:** MMC terminal, ISDN/PSTN, Analogue telephone. + +**Sequence of Events:** + +- Setup Phase:** The ISDN/PSTN sends a **SETUP** message to the MMC terminal. The message contains: + - BC: (Octet 3) 3.1 kHz audio +- Connect Phase:** The ISDN/PSTN sends a **CONNECT** message back to the MMC terminal. +- Call and Response:** The ISDN/PSTN sends a **(CALL)** message to the Analogue telephone, and the Analogue telephone sends a **(RESPONSE)** message back to the ISDN/PSTN. + +Sequence diagram for call from analogue telephone to MMC terminal via ISDN/PSTN. + +(Communication by means of speech service) + +#### 4) Call from analogue telephone to MMC terminal + +T.123(01-07)\_FI.03 + +**Figure I.3 – Intercommunication sequences for MMC terminal and analogue telephone** + +## I.3 Connection phase + +The connection procedure can be divided into the following three phases: + +- 1) Phase A (ISDN D-channel protocol) – By using the D-channel signalling protocol (see [ITU-T Q.931]), an MMC terminal makes the call control so as to establish an ISDN B-channel for communicating with an AV terminal. +- 2) Phase B (H.242 protocol) – An MMC terminal based on [ITU-T H.221] establishes frame alignment and decides communication mode based on the H.242 sequence (MMC mode/speech mode), and establishes the MLP path. + +- 3) Phase C (T.120-series protocol) – In the case that both terminals have MMC functionality and decide to communicate by MMC mode, the T.120 protocol is started and the final communication function is decided in detail, leading to the start of actual communication. + +### **I.4 Phase A (ISDN D-channel protocol)** + +In making call control based on [ITU-T Q.931] (D-channel signalling protocol), the parameters specified in Table I.1 are to be set in the SETUP message on the originating side. In this Recommendation, however, the table shows only information elements of: + +- 1) Bearer capability (BC); +- 2) Low layer capability (LLC); +- 3) High layer capability (HLC); + +all of which are needed to recognize the other terminal's communication capability. + +An MMC terminal on the calling side should set the above parameters in the SETUP message for sending, whilst on the called side it should check the parameters so as to judge the possibility of communication. Finding it possible to communicate, it may accept the call and connect to a B-channel. Then an MMC terminal starts to intercommunicate with an audiovisual terminal which may be another MMC terminal, or another type of audiovisual terminal such as videophone. + +### **I.5 Phase B (H.242 protocol)** + +After connecting to the B-channel, the following procedures should be carried out based on [ITU-T H.242]: + +- 1) Frame alignment conforming to [ITU-T H.221] is the mode. Then, by using BAS, the capability exchange sequence is executed in 7-bit PCM mode (mode 0F). +- 2) After each side recognizes the other's capability, they decide their own communication mode including common mode. That is, when both are sure of having MLP capability, the MLP path is established and the T.120 protocol is started, leading to phase C. +- 3) In the case where one side has no MLP capability, their communication is limited to audio and possibly video (for example, if one side is an MMC and the other side is a videophone). + +### **I.6 Phase C (T.120-series protocol)** + +- 1) To establish a data link connection on the MLP path. +- 2) To establish layer 4. +- 3) After channels are established, conforming with [ITU-T T.125], the negotiations, in order to recognize each other's function regarding MMC and the information necessary for the conference, are exchanged by generic conference control through the application roster. + +# **Appendix II** + +## **GSS-API security framework** + +(This appendix does not form an integral part of this Recommendation) + +## **II.1 Introduction** + +This appendix provides background on the security framework defined by the IETF generic security service-application programming interface (GSS-API) within Annex B. + +## **II.2 IETF common authentication technology (CAT)** + +This clause provides background references on various security efforts within the IETF that relate to GSS-API. + +### **II.2.1 IETF and cat working group** + +The Internet Engineering Task Force (IETF) has centralized its security work within one framework that is now commonly used across all IETF protocols. RFC 1511, entitled "Common Authentication Technology Overview", outlines this work and its purpose. + +### **II.2.2 GSS-API security framework** + +The security framework of the CAT working group is manifested by GSS-API in RFC 1508. GSS-API is an API that produces a well-defined set of data structures for communication over a reliable channel between two negotiating entities. [b-RFC 2078] explains the mechanics of the security framework. + +### **II.2.3 SPNEGO** + +The GSS-API security context negotiation can be problematical. It is possible to support multiple security mechanisms within GSS-API. However, there is no means to identify which security mechanism an opaque token is intended for. Effectively, upon receiving the first token, a calling application of GSS-API must attempt validation of the token for each installed security mechanism, until success (or ultimate failure). This approach will unambiguously arrive at the correct conclusion, but it is inefficient. To optimize the use of GSS-API, a security mechanism that enables simple negotiation is being defined by the CAT working group. The simple and protected GSS-API negotiation mechanism, or SPNEGO, is standards-track RFC 2478. + +### **II.3 T.123 Annex B security framework** + +Annex B implicitly defines a security framework for T.120. Assuming the reliable transmission case, the framework has the following characteristics. + +A list of well-known reliable security protocols. This list is extensible, allowing the inclusion of non-standard protocols (i.e., protocols not included in the list). + +Nodes that support extended transport connections can select and make use of a particular security protocol they may both support, through a simple capability negotiation mechanism using the call models specified in clause B.7. + +The caller transmits a set of reliable security protocols it can support in the CNP ConnectRequestPDU. + +The called party may signal that the services available with the current network connection are sufficient or insufficient for the security protocol desired (using either a CNP DisconnectRequestPDU or CNP ConnectConfirmPDU, respectively). In either case, the called party transmits its choice of the single reliable security protocol to use (that must be an element of the set advertised by the caller). + +In the case of sufficient services, the T.120 connection proceeds using the existing network connection (this may include negotiated transport protocol changes). + +In the case of insufficient services, the caller closes the existing network connection and creates a new network connection that provides the services indicated by the called party in the CNP DisconnectRequestPDU. + +In all of the extended profiles defined in Annex B, security is implicitly a service that exists below the X.224 class 0 or CNP layer. However, nothing prohibits a non-standard profile that may be negotiated from providing services (including security) above the X.224 class 0 or CNP layers. + +#### **II.3.1 GSS-API: Carrying GSS-API tokens via X.224 class 0 or CNP** + +The GSS-API security framework implements a process whereby a security mechanism creates opaque tokens for communication via a reliable mechanism (i.e., transport) between two negotiating entities. This process is ongoing for all communication between the entities, and therefore spans an entire session. It includes not only the set-up phase of a security context where security mechanisms may be chosen and credentials exchanged, but also any subsequent exchange of encrypted data. + +A common use of the GSS-API security framework is for the invoking application to manage the security of a session with regard to the security policy that may be locally scoped to the application. For example, the application may decide which security protocols to advertise and which credentials to select. + +Other uses of the GSS-API are of course possible. For example, an operating system network service may establish its own security context between two endpoints. Because the existence of this security context may or may not be known to a higher-level invoking application, the application may not know whether or not it needs to manage the security of its session (e.g., IP security may be invoked by the networking service, but its invocation is likely to be transparent to a higher-level application using TCP/IP). Even if it does know about another security context, the application may want to manage its own security for the session anyway. + +Consequently, the most likely use of the GSS-API security framework in the T.120 series of Recommendations is where a T.120 application desires to directly manage the security of a session. There is naturally then the question of where the T.120 application should decide to layer the GSS-API token stream within the T.120 session. + +Considering that GSS-API does not care about the communication mechanism for its token stream, Annex B specifies a scheme that signals the GSS-API security framework as a reliable security protocol within CNP and, in an extended profile, layers the GSS-API token stream above the X.224 class 0 component of layer 4 (or layers the stream above CNP in the case where CNP replaces X.224 class 0). + +# **Bibliography** + +[b-RFC 2078] IETF RFC 2078 (1997), *Generic Security Service Application Program Interface*. + + + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|---------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.124-200701-I_PDF-E/raw.md b/marked/T/T-REC-T.124-200701-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..1c94f8d72bda757b5e86f650637f9b7407ec599f --- /dev/null +++ b/marked/T/T-REC-T.124-200701-I_PDF-E/raw.md @@ -0,0 +1,6676 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**T.124** + +(01/2007) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES + +--- + +# **Generic Conference Control** + +ITU-T Recommendation T.124 + + + +## **ITU-T Recommendation T.124** + +# **Generic Conference Control** + +## **Summary** + +ITU-T Recommendation T.124 provides a high-level framework for conference management and control of multimedia terminals and Multipoint Control Units (MCUs). It encompasses Generic Conference Control (GCC) functions such as conference establishment and termination, managing the roster of terminals participating in a conference, managing the roster of applications and application capabilities within a conference, registry services for use by applications, coordination of conference conductorship, as well as other miscellaneous functions. It depends on companion Recommendations T.122 and T.125 (MCS) and T.123 as part of the T.120 infrastructure. + +This revised version of T.124 introduces a number of clarifications to the previous version. + +## **Source** + +ITU-T Recommendation T.124 was approved on 13 January 2007 by ITU-T Study Group 16 (2005-2008) under the ITU-T Recommendation A.8 procedure. + +# FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2007 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +# CONTENTS + +| | Page | +|-----------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References ..... | 2 | +| 3 Definitions ..... | 3 | +| 4 Abbreviations ..... | 7 | +| 5 Conventions ..... | 7 | +| 6 Overview ..... | 8 | +| 6.1 System model for a conference node ..... | 9 | +| 6.2 Conference establishment and termination ..... | 10 | +| 6.3 The conference roster ..... | 11 | +| 6.4 The application roster ..... | 11 | +| 6.5 The Application Registry ..... | 11 | +| 6.6 Conference conductorship ..... | 11 | +| 6.7 Miscellaneous functions ..... | 12 | +| 6.8 Scalable conferences ..... | 12 | +| 6.9 Summary of GCC abstract services ..... | 13 | +| 7 GCC service definition ..... | 17 | +| 7.1 Conference establishment and termination ..... | 17 | +| 7.2 The conference roster ..... | 54 | +| 7.3 The application roster ..... | 60 | +| 7.4 The Application Registry ..... | 74 | +| 7.5 Conference conductorship ..... | 84 | +| 7.6 Miscellaneous functions ..... | 93 | +| 8 GCC Protocol Specification ..... | 98 | +| 8.1 General operation ..... | 98 | +| 8.2 Conference establishment and termination ..... | 99 | +| 8.3 The conference and application rosters ..... | 127 | +| 8.4 The Application Registry ..... | 150 | +| 8.5 Conference conductorship ..... | 159 | +| 8.6 Miscellaneous functions ..... | 165 | +| 8.7 GCCPDU definitions ..... | 167 | +| 9 Use of the Multipoint Communication Service ..... | 189 | +| 9.1 MCS services ..... | 189 | +| 9.2 Channel allocation ..... | 190 | +| 9.3 Token allocation ..... | 191 | +| 9.4 Use of MCS data transmission services ..... | 191 | +| 9.5 Encoding of PDUs in MCS primitives ..... | 193 | +| 9.6 Format of User Data parameter of MCS-Connect-Provider ..... | 194 | +| 9.7 Interpretation of the MCS Domain Selector ..... | 194 | + +| | Page | +|------------------------------------------------------------------------|-------------| +| Annex A – Static channel and token ID assignments..... | 196 | +| A.1    Static channel ID assignments..... | 196 | +| A.2    Static token ID assignments ..... | 196 | +| Annex B – Object Identifier assignments ..... | 197 | +| Annex C – Network Address Parameter – Description and use ..... | 198 | +| Appendix I – Relationship of T.120 to H.243 in H.320 conferences ..... | 199 | +| I.1    Introduction ..... | 199 | +| I.2    Conference selection and Password protection..... | 199 | +| I.3    Alternative Node ID ..... | 200 | + +# Generic Conference Control + +# 1 Scope + +This Recommendation provides a high-level framework for conference management and control of audiographic and audiovisual terminals and Multipoint Control Units (MCUs). It encompasses Generic Conference Control (GCC) functions such as conference establishment and termination, managing the roster of nodes participating in a conference, managing the roster of Application Protocol Entities and Application Capabilities within a conference, registry services for use by Application Protocol Entities, coordination of conference conductorship, as well as other miscellaneous functions. + +This Recommendation is defined within the framework of [ITU-T T.120]. Included within this framework are companion [ITU-T T.122] and [ITU-T T.125], which define the multipoint delivery mechanism used in this Recommendation, and [ITU-T T.123], which specifies the Audiovisual Protocol Stacks for each of the communication networks supported. + +Figure 1-1 presents an overview of the scope of this Recommendation and its relationship to the other elements of the T.120 framework within a single node. + +![Figure 1-1 – Scope of T.124. This block diagram illustrates the architecture of a multimedia conferencing system. At the top, a large box represents 'User application(s) (using both standard and non-standard Application Protocols)'. Below this, three boxes represent 'User Application(s) (using std Appl. Protocols)', 'Node controller', and 'User Application(s) (using non-std Protocols)'. The 'Node controller' is connected to the 'User application(s)' box. The 'User Application(s) (using std Appl. Protocols)' box is connected to a stack of boxes representing 'T.120 Application Protocol Recommendations', which includes 'T.126 (SI) Application Protocol Entity', 'T.127 (MBFT)', and others. The 'User Application(s) (using non-std Protocols)' box is connected to a stack of boxes representing 'Non-standard Application Protocol Entity'. Both the 'T.120 Application Protocol Recommendations' and the 'Non-standard Application Protocol Entity' are connected to the 'Node controller'. The 'Node controller' is also connected to a box representing 'Generic Conference Control (GCC) T.124'. The 'Generic Conference Control (GCC) T.124' is connected to a box representing 'Multipoint Communication Service (MCS) T.122/T.125'. The 'Multipoint Communication Service (MCS) T.122/T.125' is connected to a box representing 'Network-Specific Transport Protocols T.123'. The 'Network-Specific Transport Protocols T.123' is connected to a box representing 'T.120 infrastructure Recommendations'.](3121ebddccf183ca63bb9781be440a7e_img.jpg) + +Figure 1-1 – Scope of T.124. This block diagram illustrates the architecture of a multimedia conferencing system. At the top, a large box represents 'User application(s) (using both standard and non-standard Application Protocols)'. Below this, three boxes represent 'User Application(s) (using std Appl. Protocols)', 'Node controller', and 'User Application(s) (using non-std Protocols)'. The 'Node controller' is connected to the 'User application(s)' box. The 'User Application(s) (using std Appl. Protocols)' box is connected to a stack of boxes representing 'T.120 Application Protocol Recommendations', which includes 'T.126 (SI) Application Protocol Entity', 'T.127 (MBFT)', and others. The 'User Application(s) (using non-std Protocols)' box is connected to a stack of boxes representing 'Non-standard Application Protocol Entity'. Both the 'T.120 Application Protocol Recommendations' and the 'Non-standard Application Protocol Entity' are connected to the 'Node controller'. The 'Node controller' is also connected to a box representing 'Generic Conference Control (GCC) T.124'. The 'Generic Conference Control (GCC) T.124' is connected to a box representing 'Multipoint Communication Service (MCS) T.122/T.125'. The 'Multipoint Communication Service (MCS) T.122/T.125' is connected to a box representing 'Network-Specific Transport Protocols T.123'. The 'Network-Specific Transport Protocols T.123' is connected to a box representing 'T.120 infrastructure Recommendations'. + +T.124(01-07)\_F1-01 + +**Figure 1-1 – Scope of T.124** + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T F.702] ITU-T Recommendation F.702 (1996), *Multimedia conference services*. +- [ITU-T H.221] ITU-T Recommendation H.221 (2004), *Frame structure for a 64 to 1920 kbit/s channel in audiovisual teleservices*. +- [ITU-T T.35] ITU-T Recommendation T.35 (2000), *Procedure for the allocation of ITU-T defined codes for non-standard facilities*. +- [ITU-T T.120] ITU-T Recommendation T.120 (2007), *Data protocols for multimedia conferencing*. + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------| +| [ITU-T T.122] | ITU-T Recommendation T.122 (1998), Multipoint communication service – Service definition. | +| [ITU-T T.123] | ITU-T Recommendation T.123 (2007), Network-specific data protocol stacks for multimedia conferencing. | +| [ITU-T T.125] | ITU-T Recommendation T.125 (1998), Multipoint communication service protocol specification. | +| [ITU-T T.126] | ITU-T Recommendation T.126 (1997), Multipoint still image and annotation protocol. | +| [ITU-T T.127] | ITU-T Recommendation T.127 (1995), Multipoint binary file transfer protocol. | +| [ITU-T X.680] | ITU-T Recommendation X.680 (2002) ISO/IEC 8824-1:2002, Information technology – Abstract Syntax Notation One (ASN.1): Specification of basic notation. | +| [ITU-T X.691] | ITU-T Recommendation X.691 (2002) ISO/IEC 8825-2:2002, Information technology – ASN.1 encoding rules: Specification of Packed Encoding Rules (PER). | +| [ISO/IEC 10646] | ISO/IEC 10646:2003, Information technology – Universal Multiple-Octet Coded Character Set (UCS). | + +# 3 Definitions + +This Recommendation defines the following terms: + +**3.1 anonymous node:** This node category describes a T.120 node that can participate in a conference while not being visible to any other nodes in the conference. The presence of Anonymous nodes is needed to facilitate large-scale T.120 conferences. + +**3.2 application protocol:** Any standard or non-standard protocol specification which is designed to make use of T.120 services. + +**3.3 application protocol entity:** The instantiation of an Application Protocol in a terminal or MCU. Application Protocol Entities are employed by User Applications, but are not themselves User Applications. An Application Protocol Entity communicates with GCC through the GCC Provider present at its local terminal or MCU via a GCCSAP. Only Application Protocol Entities communicate with GCC Providers; User Applications do not. Multiple Application Protocol Entities based on the same Application Protocol may enroll at a single node. These may be either in the same or separate Application Protocol Sessions. A single Application Protocol Entity is assumed to communicate with the local GCC Provider via a single GCCSAP, and is also assumed to have a single MCS User ID if it has enrolled in the active state. An Application Protocol Entity which has enrolled in the active state is part of a single Application Protocol Session as indicated by its Session ID (or lack of a Session ID which indicates that it is part of the Default Session). An Application Protocol Entity which has enrolled in the inactive state is not considered part of any Application Protocol Session; however, an inactive Application Protocol Entity may make use of GCC services and information associated with such an Application Protocol Entity is included in the Application Roster. + +**3.4 application protocol key:** The Application Protocol Key identifies the type of Application Protocol for an Application Protocol Session. Multiple Application Protocol Sessions of the same type would be identified using the same Application Protocol Key (but different Session IDs). An Application Protocol Key is either an ASN.1 OBJECT IDENTIFIER belonging to a Recommendation, Standard, or non-standard protocol, or, alternatively, it is a non-standard identifier using the encoding conventions of [ITU-T H.221]. + +- 3.5 application protocol session:** A set of Peer Application Protocol Entities. +- 3.6 application record:** A set of information for a specific Application Protocol Entity at a specific node. This set includes the Application User ID, the Active/Inactive flag, as well as other parameters. +- 3.7 application registry:** A central repository located at the Top GCC Provider where an Application Protocol Entity can register its use of tokens, channels, and other parameters. Peer Application Protocol Entities can then access the registry to discover this registered information. +- 3.8 application roster:** The set of all Application Records from all enrolled Application Protocol Entities at all nodes in a conference, including the Application Capabilities List for each Application Protocol Session. +- 3.9 application user ID:** MCS User ID assigned by MCS to an Application Protocol Entity. +- 3.10 conducted mode:** Conducted Mode allows a Conductor node the ability to control Application Protocol Entities at all nodes in a conference, and to restrict operation of Application Protocol Entities by other nodes. Conducted mode is established when a Conductor has been assigned to a conference. This is achieved when a node has successfully grabbed the conference Conductor Token. +- 3.11 conductor:** The Conductor, if present, is a node in a conference which controls certain aspects of the conference (e.g., control of communication between Application Protocol Entities, control over conference participants, and conference termination). There shall be either zero or one Conductors in a conference. A node becomes conductor by grabbing the conductor token, or by requesting or accepting conductorship from the current conductor. +- 3.12 conference:** A number of nodes that are joined together and that are capable of exchanging audiographic and audiovisual information across various communication networks. +- 3.13 conference application roster:** A database maintained by each GCC Provider consisting of a set of Application Records, one for every Application Protocol Entity at every node in the conference, as well as other information such as the Application Capabilities List for each Application Protocol Session. +- 3.14 conference mode:** When a conference is created, a Conference Mode is specified, by the Convener, that defines which Categories of nodes will be allowed to participate in the conference. These Conference Modes include the following: *conventional-only*, which allows only Conventional nodes to join the conference; *counted-controlled*, which allows only Counted and Conventional nodes to join the conference; *anonymous-controlled*, which allows only Anonymous and Conventional nodes to join the conference; and *unrestricted-mode*, which allows all three node categories to participate in the conference. The Node Controller must use the T.124 password to determine which nodes may join as Conventional when the Conference Mode is either *counted-controlled* or *anonymous-controlled*. +- 3.15 conference profile:** A database maintained by each GCC Provider consisting of information pertinent to a conference as a whole such as Conference Name, Password (if any), etc. +- 3.16 conference roster:** A database maintained by each GCC Provider consisting of a list of nodes in a conference. For each node, this list includes the Node ID of the node, type of the node, the name of the node, and may include a list of participants at the node, as well as other optional information. +- 3.17 control GCC service access point:** The communication interface between a GCC Provider and the Node Controller within a single node. +- 3.18 convener:** Node that created a conference by issuing the GCC-Conference-Create request primitive. + +**3.19 convener password:** An identifying numeric string, as well as optional text string, which may be used when a conference is created to allow the convener of the conference to leave the conference and re-enter at a later time using the password to regain convener privileges. A Convener Password must be included during conference creation (in one of its two possible forms) for this to be possible. Use of the correct Convener Password allows joining of a locked conference, but it does not avoid the need to specify the correct Password when joining a Password protected conference. + +**3.20 conventional node:** This is the most basic category of a T.120 node. The Conventional node category defines a fully capable node that is included in all roster exchanges. + +**3.21 counted node:** This node category describes a node with the following properties: the node appears in rosters of conventional nodes, the node does not affect conference capabilities, and the node can participate in acknowledge-mode APE sessions. A counted node provides a way for (which provide the content) and a large number of counted nodes (which can acknowledge the reception of the content being sourced). + +**3.22 default session:** Active Application Protocol Entities with no Session ID included in their Session Key are considered part of a separate unique session referred to as the Default Session. + +**3.23 entity ID:** A 16-bit numeric identifier used to identify each Application Protocol Entity enrolled at a node. The value of the Entity ID is unique among all Application Protocol Entities of any type within a single node. It need not be unique between nodes. A particular Application Protocol Entity in a conference may be uniquely identified by the combination of the Entity ID and the Node ID corresponding to the node at which the Application Protocol Entity is enrolled. + +**3.24 GCC provider:** Agent providing GCC services to local Node Controller and Application Protocol Entities at a terminal or MCU. + +**3.25 GCC service access point:** The communication interface between a GCC Provider and an Application Protocol Entity within a single node. + +**3.26 handle:** A 32-bit integer number allocated by the Top GCC Provider using the GCC-Registry-Allocate-Handle request primitive. This number is guaranteed to be unique within a conference. + +**3.27 local application roster:** A database maintained by each GCC Provider consisting of one Application Record as well as other information, such as the Application Capabilities List, for each Application Protocol Entity which has locally enrolled with the GCC Provider. This is used to form the information exchanged with other nodes to determine the Conference Application Roster. + +**3.28 MCS domain:** A hierarchy of MCS connections between nodes. Nodes may use MCS services to communicate within a single domain, but not between separate domains. A GCC Conference corresponds one-to-one with a single MCS Domain. + +**3.29 MCS domain selector:** A locally unique identifier of an MCS Domain. + +**3.30 MCS user ID:** Unique identification number assigned by MCS to an MCS User. GCC Providers as well as Application Protocol Entities are MCS Users. An MCS User ID assigned to a GCC Provider is referred to as a Node ID. An MCS User ID assigned to an Application Protocol Entity is referred to as an Application User ID. An MCS User ID is valid only within a single MCS Domain. + +**3.31 multipoint:** The ability to exchange data among multiple nodes simultaneously as compared with point-to-point, where data are exchanged between two directly connected nodes. + +**3.32 multipoint control unit:** Commonly referred to as an MCU or bridge, a multiport device that serves to connect terminals and other MCUs in a multipoint fashion. A GCC-capable MCU runs GCC and MCS. An MCU is not primarily intended as an end-point for user communication. + +**3.33 multiport terminal:** End-point audiographic or audiovisual equipment that also includes the ability to bridge T.120 information. Like a terminal, the behaviour of a multiport terminal is typified + +by automatic establishment of a single conference. But, like an MCU, for a given conference in a multiport terminal, there may be more than one MCS connection. + +**3.34 node:** A terminal, multiport terminal, or MCU. A single node comprises a single GCC provider. A single node may consist of one or more physical devices. Similarly, one physical device may host several logical nodes. + +**3.35 node category:** Every T.120 node falls into one of three categories: Conventional, Counted, or Anonymous. These node categories allow for different degrees of scalability within a T.120 conference. + +**3.36 node controller:** A functional entity for which there is one for each terminal or MCU, which serves as the controller of that node. + +**3.37 node ID:** MCS User ID assigned by MCS to the GCC Provider at a node. + +**3.38 non-conducted mode:** The mode in which a conference has no Conductor. + +**3.39 participant:** A person participating in a conference at a node. + +**3.40 password:** A numeric string, as well as an optional text string, which may be specified when a conference is created. If so, when attempting to join a conference, a node must include this Password (in one of the two possible forms) in the GCC-Conference-Join primitive in order for that node to be accepted into the conference. + +**3.41 peer application protocol entity:** Application Protocol Entities which have enrolled in the active state using identical Session Keys, including the Session ID portion of the Session Key. Peer Application Protocols are those which may communicate with each other during a conference. + +**3.42 resource:** Something that can be used and shared by nodes in a conference. A resource comprises both channels and tokens. + +**3.43 session ID:** An optional parameter included in a Session Key used to distinguish between multiple sets of Peer Application Protocol Entities which are based on the same base Application Protocol. Each set of Peer Application Protocol Entities, defined by the use of a common Application Protocol and identical Session IDs, separately communicate among themselves. Active Application Protocol Entities with no Session ID included in their Session Key are considered part of a separate unique session referred to as the Default Session. A set of Peer Application Protocol Entities is referred to as an Application Protocol Session. Session IDs are in the form of MCS Channel IDs. + +**3.44 session key:** An identifier which is common to Peer Application Protocol Entities. A Session Key consists of two components. One component, the Application Protocol Key identifies the type of Application Protocol. The second component, which is an optional part of a Session Key, is the Session ID which identifies the specific session for this Application Protocol (the lack of a Session ID indicates the Default Session). Application Protocol Entities whose entire Session Keys are in common, including the Application Protocol Key as well as the Session ID, if any, are considered Peer Application Protocol Entities. + +**3.45 terminal:** End-point audiographic or audiovisual equipment. A GCC-capable terminal runs GCC and MCS. A terminal is limited, within a conference, to a single MCS connection. + +**3.46 top GCC provider:** The GCC Provider which is co-resident with the Top MCS Provider in a conference. The Top GCC Provider has responsibilities not required of other GCC Providers in a conference. The location of the Top GCC Provider remains unchanged for the duration of a conference. + +**3.47 Unicode:** Multilingual text string format as defined by the Basic Multilingual Plane of [ISO/IEC 10646]. + +**3.48 Unicode row 00:** A subset of Unicode consisting of 256 code positions containing the Basic Latin and Latin-1 Supplement character sets plus control characters and reserved codes. + +**3.49 user application:** An entity which makes use of one or more Application Protocol Entities. A User Application is limited in its scope to those tasks which have no effect on the interpretation of information between Peer Application Protocol Entities such as presentation to the end-user. User Applications therefore do not require specification, either by standard Recommendation or otherwise, to allow interoperability between the Application Protocol Entities which they make use of and their Peer Application Protocol Entities. + +# 4 Abbreviations + +This Recommendation uses the following abbreviations: + +| | | +|--------|-------------------------------------------------| +| CSDN | Circuit Switched Data Network | +| GCC | Generic Conference Control | +| GCCSAP | Generic Conference Control Service Access Point | +| ISDN | Integrated Services Digital Network | +| MCS | Multipoint Communication Service | +| MCU | Multipoint Control Unit | +| PDU | Protocol Data Unit | +| PSDN | Packet Switched Data Network | +| PSTN | Public Switched Telephone Network | + +The following abbreviations are used in this Recommendation and defined in [ITU-T T.122]: + +| | | +|-------|-----------------------------------------------| +| MCS | Multipoint Communication Service | +| MCSAP | Multipoint Communication Service Access Point | + +# 5 Conventions + +The primitive parameters of the abstract services defined in this Recommendation use the following key: + +| | | +|-------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| M | Parameter is mandatory | +| C | Parameter is conditional | +| O | Parameter is optional | +| Blank | Parameter is absent | +| (=) | Value of the parameter is identical to the value of the corresponding parameter of the preceding primitive, where preceding is defined relative to the order: request, indication, response, confirm. | +| (=RQ) | Value of the parameter is identical to the value of the corresponding parameter in a preceding primitive, where RQ = request, IN = indication, RS = response, and CF = confirm. | + +Primitives are categorized in up to four types: Request, Indication, Response, and Confirm. Some primitives support all of these types, while others do not. These four types are defined as follows: + +- Request primitive: Those that are sourced from a Node Controller or Application Protocol Entity to initiate a certain action. +- Indication primitive: Those that are sourced from a GCC Provider either as a result of a Request primitive, or as a result of a GCC initiated action. + +- Response primitive: Those that are sourced from a Node Controller or Application Protocol Entity in response to an Indication primitive which is defined to require a response. +- Confirm primitive: Those that are sourced from a GCC Provider as a result of a Response primitive. + +PDU names are categorized into three types. PDU names all include the words Request, Indication, or Response to indicate the intended use of the PDU. These are defined as follows: + +- Request PDUs: Those that require a Response PDU in return. If the request is for a function which is not supported by the receiving node (e.g., an optional or non-standard PDU), a generic response PDU, FunctionNotSupportedResponse, shall be used to provide a response to the requesting node (sent to the Node ID Channel of the requesting node). +- Indication PDUs: Those that do not require a response (e.g., those that are for informational purposes). +- Response PDUs: Those which are in response to a particular Request PDU to be sent on the Node ID Channel of the requesting node. + +# 6 Overview + +Within the context of the ITU-T Audiovisual Conferencing Service, a conference refers to a group of geographically dispersed nodes that are joined together and that are capable of exchanging audiographic and audiovisual information across various communication networks. Participants taking part in a conference may have access to various types of media handling capabilities such as audio only (telephony), audio and data (audiographics), audio and video (audiovisual), and audio, video, and data (multimedia). + +The F-, G-, H-, and T-series Recommendations provide a framework for the interworking of audio, video, and graphics terminals on a point-to-point basis through existing telecommunication networks. They also provide the capability for three or more terminals in the same conference to be interconnected by means of an MCU. + +This Recommendation provides a high-level framework for conference management and control of audiographics and audiovisual terminals, and MCUs. It coexists with companion [ITU-T T.122] and [ITU-T T.125] (MCS) and [ITU-T T.123] (AVPS) to provide a mechanism for conference establishment and control. [ITU-T T.122], [ITU-T T.123], [ITU-T T.124], and [ITU-T T.125] form the minimum set of Recommendations to develop a fully functional terminal or MCU. + +This Recommendation includes the following Generic Conference Control (GCC) functional components: conference establishment and termination, managing the Conference Roster, managing the Application Roster, Application Registry services, and conference conductorship. The service definitions for the primitives associated with these functional components are contained in clause 7. The corresponding protocol definitions are contained in clause 8. + +Figure 6-1 shows an example of how GCC components are distributed throughout an MCS domain. The GCC components are shown in white. Each terminal or MCU contains a GCC Provider that provides GCC services to the local Node Controller and Application Protocol Entities. + +![Figure 6-1: Example of GCC components distributed throughout an MCS domain. The diagram shows four nodes connected via MCS connections. Node 1 (top) contains a Top GCC Provider and a Node Controller. Node 2 (bottom left) contains a GCC Provider, an Application Protocol Entity, and a Node Controller. Node 3 (bottom middle) contains a GCC Provider and a Node Controller. Node 4 (bottom right) contains a GCC Provider, multiple overlapping Application Protocol Entities, and a Node Controller. All nodes are connected to a central 'MCS connections' hub.](33ed1f9b27c7c21c797aa928b0f06851_img.jpg) + +T.124(01-07)\_F6-01 + +Figure 6-1: Example of GCC components distributed throughout an MCS domain. The diagram shows four nodes connected via MCS connections. Node 1 (top) contains a Top GCC Provider and a Node Controller. Node 2 (bottom left) contains a GCC Provider, an Application Protocol Entity, and a Node Controller. Node 3 (bottom middle) contains a GCC Provider and a Node Controller. Node 4 (bottom right) contains a GCC Provider, multiple overlapping Application Protocol Entities, and a Node Controller. All nodes are connected to a central 'MCS connections' hub. + +**Figure 6-1 – Example of GCC components distributed throughout an MCS domain** + +## 6.1 System model for a conference node + +Each Node participating in a GCC conference consists of an MCS layer, a GCC layer, a Node Controller and may also include one or more Application Protocol Entities. The relationship between these components within a single node is illustrated in Figure 6-2. The Node Controller is the controlling entity at a node, dealing with the aspects of a conference that apply to the entire node. The Node Controller interacts with GCC, but does not interact directly with MCS. Application Protocol Entities also interact with GCC, as well as directly with MCS. The services provided by GCC to Application Protocol Entities are primarily to enable Peer Application Protocol Entities to communicate directly, via MCS. Local communication between individual Application Protocol Entities or between Application Protocol Entities and the Node Controller may take place, but is a local implementation matter not covered by this Recommendation. Within a node, more than one Application Protocol Entity may be based on the same Application Protocol. In this case, they may either be part of the same Application Protocol Session, allowing them to communicate within the node as well as to other Peer Application Protocol Entities at other nodes, or they may be part of separate Application Protocol Sessions, allowing them to communicate separately among their peers, but using the same protocol. + +The service primitives, as described in clause 7, apply to the GCC Service Access Point and the Control GCC Service Access Point as indicated in Figure 6-2. The PDUs described in clause 8 are communicated using MCS service primitives available at the Control MCS Access Point (MCSAP). + +NOTE 1 – The normative intent of this Recommendation is to specify the procedures and contents of external communication – sequences of primitive operations and data exchanges acting through the Control MCSAP for purposes of conference control. The internal decomposition of a node suggested in Figure 6-2 serves to motivate features of the GCC protocol but is not normative. GCC service primitives whose effect is purely local need not exist at all nodes in the form that they are described here. Statements about what a node controller or an application protocol entity shall do in certain circumstances should be interpreted loosely if the same results in external communication can be achieved through different internal mechanisms. + +NOTE 2 – The system model assumes that service requests may be issued at any time. A Node Controller or Application Protocol Entity need not wait until it has received a confirm from the GCC Provider corresponding to a previous request before issuing another request. A specific implementation may, however, impose stricter requirements. + +![Figure 6-2: System model showing GCC Service Access Point and relationship with MCS. The diagram illustrates the interactions between four main components: Node Controller, Application Protocol Entities, GCC Provider, and MCS Provider. The Node Controller and Application Protocol Entities are at the top, connected by a bidirectional arrow labeled 'Control GCC Service Access Point'. The GCC Provider is in the middle, connected to the Node Controller by a bidirectional arrow labeled 'GCC Service Access Points'. The MCS Provider is at the bottom, connected to the GCC Provider by a bidirectional arrow labeled 'Control MCS Access Point'. The Application Protocol Entities are also connected to the MCS Provider by a bidirectional arrow labeled 'MCS Access Points'. The Application Protocol Entities are represented by a stack of three boxes, indicating multiple instances.](5cab96b2d23174c25919840ecd50aa48_img.jpg) + +``` + +graph TD + NC[Node Controller] <-->|Control GCC Service Access Point| GCP[GCC Provider] + GCP <-->|GCC Service Access Points| APE[Application Protocol Entities] + GCP <-->|Control MCS Access Point| MCP[MCS Provider] + APE <-->|MCS Access Points| MCP + +``` + +T.124(01-07)\_F6-02 + +Figure 6-2: System model showing GCC Service Access Point and relationship with MCS. The diagram illustrates the interactions between four main components: Node Controller, Application Protocol Entities, GCC Provider, and MCS Provider. The Node Controller and Application Protocol Entities are at the top, connected by a bidirectional arrow labeled 'Control GCC Service Access Point'. The GCC Provider is in the middle, connected to the Node Controller by a bidirectional arrow labeled 'GCC Service Access Points'. The MCS Provider is at the bottom, connected to the GCC Provider by a bidirectional arrow labeled 'Control MCS Access Point'. The Application Protocol Entities are also connected to the MCS Provider by a bidirectional arrow labeled 'MCS Access Points'. The Application Protocol Entities are represented by a stack of three boxes, indicating multiple instances. + +**Figure 6-2 – System model showing GCC Service Access Point and relationship with MCS** + +## 6.2 Conference establishment and termination + +GCC provides a set of services for establishment and termination of conferences. A conference can be viewed as a meeting room in which any number of participants may meet in order to exchange audiographic or audiovisual information. As with physical meeting rooms, services such as finding out what conferences are in progress, joining a conference, leaving a conference, restricting access to a conference, etc., are meaningful in audiographic and audiovisual conferences as well. + +Prior to joining a conference, participants at a node may not know all of the information needed to join. GCC provides a means for participants to view a list of Conference Names and select the one they wish to join. This service is analogous to the conference schedule typically posted in a lobby, allowing someone to find the meeting room in which a particular meeting is taking place. + +GCC provides a means to create new conferences. This may be done either by a conference participant, or by a conference administrator. When a new conference is created, its characteristics, referred to as its Conference Profile, are specified by its creator. The Conference Profile includes such things as the Conference Name, whether it has restricted access by means of a Password, whether it is open to be freely joined (unlocked) or restricted to be joined by invitation only (locked). + +Expanding an existing conference may be initiated by the joining node, or by a conference Convener (or convener designated node). If a conference is Password protected, a joining node is required to supply the correct Password to be allowed into the conference. If a conference is locked, joining is only allowed at the request of the Convener, or convener-designated node. Nodes may join or be added at any time during a conference. It is possible to be joined with more than one conference simultaneously. GCC also provides a means of transferring participants from one conference to + +another. This function may be used to achieve the effect of merging two conferences, or splitting a conference into more than one conference. + +At any time a node may wish to disconnect from the conference, leaving the other nodes to continue the conference. Depending on the choice of termination method, a conference is either automatically terminated if all nodes disconnect from it, or manually terminated by an explicit termination request. The convener, or a convener-designated node may also forcibly terminate the entire conference at any time, or eject a particular node from it. + +## **6.3 The conference roster** + +Once a node has joined a conference, it announces its presence to all other nodes in the conference. A GCC primitive is provided to allow each node in a conference to announce its presence in a conference, and another to provide each node with either updates to the conference roster or a full conference roster. The conference roster is a list of Conventional and possible Counted nodes in the conference. For each node the conference roster includes information such as the name of the node, a list of participants at that node, as well as other information needed for proper communication between nodes. A Conventional or Counted node is not considered part of a conference until it has been included in the conference roster. + +## **6.4 The application roster** + +GCC provides a means of identifying which Application Protocol Entities are available at each node and also provides necessary information for Peer Application Protocol Entities to communicate with each other. Upon joining a conference, each Conventional or Counted node sends to all other nodes its local list of Application Protocol Entities – its Local Application Roster – which it may update at any time thereafter. From this information, the Conference Application Roster is formed and broadcast to all interested nodes. Relevant portions of this roster are then communicated locally to each Application Protocol Entity as well as to the Node Controller. In addition to a simple roster, GCC also provides a service for Application Protocol Entities at Conventional Nodes to include a list of Application Protocol-specific capabilities in the information exchanged. GCC applies a fixed set of rules to this information from all nodes in the conference to determine a common set of Application Capabilities. This information is also communicated locally to each Application Protocol Entity. + +## **6.5 The Application Registry** + +The Application Registry is an active database residing at the Top GCC Provider that may be used to manage channels, tokens, and other shared resources used in a conference. The Application Registry can aid in establishing communication among peer Application Protocol Entities. + +## **6.6 Conference conductorship** + +GCC provides a method for allowing a node to become a conductor for a conference. A token is used by GCC to determine whether a conference is conducted or non-conducted. The node which grabs the conductor token becomes the conductor of the conference. A node may also request conductorship or accept conductorship from the current conductor. Upon request, GCC provides the identity of the current conference conductor. On creation of a conference, it may be specified that conducted mode is not permitted for the duration of the conference. + +Conducted mode is available as a means to provide order to the course of a conference. The actual means by which this order is provided is determined by the Application Protocols. Specifically, Recommendations specifying Application Protocols may define alternative procedures depending on whether the conference is conducted or non-conducted. GCC does provide a mechanism for basic conducted operation which may be made use of by Application Protocols. A mechanism is provided by which a node may request permission from the conducting node, and if permission is granted, all Application Protocol Entities at that node may act accordingly as specified by the Application + +Protocol specification. Application Protocols may, for example, specify strict limitations in the allowed operations for nodes that do not have permission from the conductor, while removing some or all of these limitations for nodes which have this permission. Application protocols may also, for example, specify that once overall permission has been granted by the conductor, further permission must be granted by the Peer Application Protocol Entity at the conducted node, if one exists, before allowing certain operations to be performed. + +## **6.7 Miscellaneous functions** + +A method is provided for coordinating timed conferences. A mechanism is provided for a node to find out how much time is remaining in a timed conference, as well as a mechanism for announcing to all nodes how much time is remaining (which would typically be used to announce that the time is almost up), and a mechanism for nodes to request more time to be added, if available. + +A method is also provided to request assistance from an unspecified operator. Another function is provided to allow transmission of simple text messages. + +## **6.8 Scalable conferences** + +The T.124 protocol is designed to allow for a number of different degrees of scalability, including small "tightly coupled" conferences, medium-sized "acknowledged" conferences, and very large "loosely coupled" conferences. This is accomplished through the use of three Node Categories, each of which allows for a varying degree of scalability. These categories include Conventional, Counted and Anonymous. An overview of each of these categories follows. + +Conventional Nodes provide a large amount of node information to every node in a conference and are the most heavy-weight in terms of how they affect the other members of the conference. Using this category is appropriate for principal members of a loosely-coupled conference or for all nodes involved in a small tightly-coupled conference. Conventional Nodes are responsible for creating all APE sessions within a conference and also dictate the capabilities negotiated in those sessions. Each T.124 conference must include at least one Conventional Node. Also, each APE session must include at least one conventional node as long as the session exists. Once all Conventional nodes have left an APE session, that session ceases to exist. + +Counted Nodes are somewhat less heavy-weight than Conventional Nodes. Nodes of this type only appear in rosters received by Conventional Nodes. Counted nodes cannot create APE sessions and they do not affect session capabilities. The capabilities for each APE session are established by the Conventional Nodes participating in the conference. Counted Nodes are typically used in situations where there is a need to acknowledge receiving data that is sourced by a Conventional Node. Conferences with Counted Node participants scale better than conferences with only Conventional Nodes, but are still limited in size due to the exchange of roster information. Counted nodes may source content for the conference, but that content can never be acknowledged. + +Anonymous Nodes are the lightest-weight of the three Node Categories. Nodes in this category do not affect conference or application rosters, cannot create APE sessions, and do not affect conference capabilities. Their purpose is to allow for very large-scale conferences in environments where there are a small number of presenters and a large number of observers. A typical conference scenario could include a small number of Conventional nodes, which would be the principal contributors of the conference and a large number of Anonymous node observers. + +Prior to the introduction of Node Categories, the number of nodes that could participate in a GCC conference was severely limited. Node Categories make it possible to support a number of different conference scaling models. Because legacy nodes that are not aware of Node Categories must continue to be supported within the T.120 framework, a few restrictions are necessary to ensure backward compatibility. Also, an additional feature of GCC that facilitates scalable conferences is the use of Roster Delta Updates by the Top Provider when notifying conference participants that a node has joined, left, or changed a Roster record. Again, this feature was not supported in the + +original version of GCC. The following rules must be abided by to ensure backward compatibility with legacy nodes: + +- A node can only be considered Anonymous or Counted if it joins the conference through a node that is Node Category-aware. Also, all nodes from the joining node to the Top Provider (including the Top Provider) must also be Node Category aware. +- Nodes that are not Node Category-aware, or do not indicate an understanding of Node Categories when joining a conference, are always treated as Conventional. +- The Top Provider, Convener, and all Management nodes are always categorized as Conventional nodes. +- All T.124 nodes, except those that will only participate in a T.120 conference as Anonymous or Counted terminal nodes must continue to support the legacy GCC-Broadcast-Channel as well as the GCC-Conventional-Broadcast-Channel and the GCC-Counted-Broadcast-Channel if necessary (see explanation of all broadcast channels in the Protocol definition of this Recommendation). +- Only Conventional nodes are allowed to add, delete, or change the parameters within the registry. To support Counted and Anonymous nodes, the registry can be read by any node that makes a request to do so, including nodes that are not listed in the Conference or Application rosters. +- There are no topology restrictions on which categories of nodes can be connected to which categories of nodes as long as all the nodes above a node that is expecting to use the Node Category related protocol is also Node Category-aware. + +In summary, when a conference is created, a Conference Mode is specified that defines which Categories of nodes will be allowed to participate in the conference. It is the responsibility of both the GCC Provider and the Node Controller at the Top Provider to determine which Categories a joining node must fall into. These Conference Modes include the following: *conventional-only*, which allows only Conventional nodes to join the conference; *counted-controlled*, which allows only Counted and Conventional nodes to join the conference; *anonymous-controlled*, which allows only Anonymous and Conventional nodes to join the conference; and *unrestricted-mode*, which allows all three node categories to participate in the conference. The Node Controller must use the T.124 password to determine which nodes may join as Conventional when the Conference Mode is either *counted-controlled* or *anonymous-controlled*. + +## 6.9 Summary of GCC abstract services + +Table 6-1 is a list of all GCC primitives and their associated PDUs. The table also shows whether or not each primitive is mandatory (M), conditionally required (C), or optional (O) for a terminal or an MCU. For a multiport terminal, for each primitive, the requirement shall be taken to be the most restrictive of either a terminal or MCU for that primitive. A conditionally required primitive is one which is required if the Application Protocol specification for one or more Application Protocol Entities located at that node mandates its use. The table also shows, for the corresponding PDUs, whether these are mandatory (M) or conditionally required (C) for both the transmit (T) and receive (R) directions. Again, for a multiport terminal, the requirement shall be taken to be the most restrictive of either a terminal or MCU for that PDU. A conditionally required PDU is one which is required only if the corresponding primitive is to be supported at that node. In the case that a primitive is not mandatory, but its corresponding PDU is mandatory, this implies that there is some portion of the protocol, not related to the primitive, that relies on the use of that PDU which is required to be supported. + +**Table 6-1 – GCC Primitives and PDUs** + +| Functional unit | Primitives | Term | MCU | Associated PDUs | Dir. | Term | MCU | +|------------------------------------------|---------------------------------------|------|-----|--------------------------------------------------------|--------------|--------|--------| +| Conference establishment and termination | GCC-Conference-Create request | M | O | ConferenceCreateRequest | T | M | C | +| | GCC-Conference-Create indication | M | M | ConferenceCreateRequest | R | M | M | +| | GCC-Conference-Create response | M | M | ConferenceCreateResponse | T | M | M | +| | GCC-Conference-Create confirm | M | O | ConferenceCreateResponse
UserIDIndication | R
T, R | M | C
M | +| | GCC-Conference-Query request | M | M | ConferenceQueryRequest | T | M | M | +| | GCC-Conference-Query indication | M | M | ConferenceQueryRequest | R | M | M | +| | GCC-Conference-Query response | M | M | ConferenceQueryResponse | T | M | M | +| | GCC-Conference-Query confirm | M | M | ConferenceQueryResponse | R | M | M | +| | GCC-Conference-Join request | M | O | ConferenceJoinRequest | T | M | C | +| | GCC-Conference-Join indication | O | M | ConferenceJoinRequest | R | C | M | +| | GCC-Conference-Join response | O | M | ConferenceJoinResponse | T | C | M | +| | GCC-Conference-Join confirm | M | O | ConferenceJoinResponse
UserIDIndication | R
T, R | M | C
M | +| | GCC-Conference-Invite request | O | M | ConferenceInviteRequest | T | C | M | +| | GCC-Conference-Invite indication | M | M | ConferenceInviteRequest | R | M | M | +| | GCC-Conference-Invite response | M | M | ConferenceInviteResponse | T | M | M | +| | GCC-Conference-Invite confirm | O | M | ConferenceInviteResponse
UserIDIndication | R
T, R | C
M | M
M | +| | GCC-Conference-Add request | O | O | ConferenceAddRequest | T | C | C | +| | GCC-Conference-Add indication | O | O | ConferenceAddRequest | R | C | C | +| | GCC-Conference-Add response | O | O | ConferenceAddResponse | T | C | C | +| | GCC-Conference-Add confirm | O | O | ConferenceAddResponse | R | C | C | +| | GCC-Conference-Lock request | O | O | ConferenceLockRequest | T | C | C | +| | GCC-Conference-Lock indication | O | O | ConferenceLockRequest | R | C | C | +| | GCC-Conference-Lock response | O | O | ConferenceLockResponse | T | C | C | +| | GCC-Conference-Lock confirm | O | O | ConferenceLockResponse | R | C | C | +| | GCC-Conference-Unlock request | O | O | ConferenceUnlockRequest | T | C | C | +| | GCC-Conference-Unlock indication | O | O | ConferenceUnlockRequest | R | C | C | +| | GCC-Conference-Unlock response | O | O | ConferenceUnlockResponse | T | C | C | +| | GCC-Conference-Unlock confirm | O | O | ConferenceUnlockResponse | R | C | C | +| | GCC-Conference-Lock-Report indication | O | O | ConferenceLockIndication
ConferenceUnlockIndication | T, R
T, R | C
C | C
C | +| | GCC-Conference-Disconnect request | M | M | – | – | – | – | +| | GCC-Conference-Disconnect indication | M | M | – | – | – | – | +| | GCC-Conference-Disconnect confirm | M | M | – | – | – | – | +| | GCC-Conference-Terminate request | O | O | ConferenceTerminateRequest | T | C | C | +| | GCC-Conference-Terminate indication | M | M | ConferenceTerminateRequest | R | M | M | +| | | | | ConferenceTerminateIndication | T | M | M | +| | | | | ConferenceTerminateIndication | R | M | M | +| | GCC-Conference-Terminate confirm | O | O | ConferenceTerminateResponse | T | M | M | +| | | | | ConferenceTerminateResponse | R | C | C | + +**Table 6-1 – GCC Primitives and PDUs** + +| Functional unit | Primitives | Term | MCU | Associated PDUs | Dir. | Term | MCU | +|----------------------|-------------------------------------------------|------|-----|--------------------------------|------|------|-----| +| | GCC-Conference-Eject-User request | O | O | ConferenceEjectUserRequest | T | C | C | +| | | | | ConferenceEjectUserRequest | R | M | M | +| | GCC-Conference-Eject-User indication | M | M | ConferenceEjectUserIndication | T | M | M | +| | | | | ConferenceEjectUserIndication | R | M | M | +| | GCC-Conference-Eject-User confirm | O | O | ConferenceEjectUserResponse | T | M | M | +| | | | | ConferenceEjectUserResponse | R | C | C | +| | GCC-Conference-Transfer request | O | M | ConferenceTransferRequest | T | C | M | +| | | | | ConferenceTransferRequest | R | M | M | +| | GCC-Conference-Transfer indication | M | M | ConferenceTransferIndication | T | M | M | +| | | | | ConferenceTransferIndication | R | M | M | +| | GCC-Conference-Transfer confirm | O | M | ConferenceTransferResponse | T | M | M | +| | | | | ConferenceTransferResponse | R | C | M | +| Conference roster | GCC-Conference-Announce-Presence request | M | M | RosterUpdateIndication | T, R | M | M | +| | GCC-Conference-Announce-Presence confirm | M | M | – | – | | | +| | GCC-Conference-Roster-Report indication | M | M | RosterUpdateIndication | T, R | M | M | +| | GCC-Conference-Roster-Inquire request | O | O | – | – | – | – | +| | GCC-Conference-Roster-Inquire confirm | O | O | – | – | – | – | +| Application roster | GCC-Application-Permission-To-Enroll indication | M | C | – | – | – | – | +| | GCC-Application-Enroll request | M | C | RosterUpdateIndication | T, R | M | M | +| | | | | RosterRefreshRequest | T, R | C | C | +| | GCC-Application-Enroll confirm | M | C | – | – | | | +| | GCC-Application-Roster-Report indication | M | C | RosterUpdateIndication | T, R | M | M | +| | GCC-Application-Roster-Inquire request | O | O | – | – | – | – | +| | GCC-Application-Roster-Inquire confirm | O | O | – | – | – | – | +| | GCC-Application-Invoke request | O | O | ApplicationInvokeIndication | T | C | C | +| | GCC-Application-Invoke indication | O | O | ApplicationInvokeIndication | R | C | C | +| | GCC-Application-Invoke confirm | O | O | – | – | – | – | +| Application registry | GCC-Registry-Register-Channel request | C | C | RegistryRegisterChannelRequest | T | C | C | +| | | | | RegistryRegisterChannelRequest | R | M | M | +| | GCC-Registry-Register-Channel confirm | C | C | RegistryResponse | T | M | M | +| | | | | RegistryResponse | R | C | C | +| | GCC-Registry-Assign-Token request | C | C | RegistryAssignTokenRequest | T | C | C | +| | | | | RegistryAssignTokenRequest | R | M | M | +| | GCC-Registry-Assign-Token confirm | C | C | RegistryResponse | T | M | M | +| | | | | RegistryResponse | R | C | C | +| | GCC-Registry-Set-Parameter request | C | C | RegistrySetParameterRequest | T | C | C | +| | GCC-Registry-Set-Parameter confirm | C | C | RegistrySetParameterRequest | R | M | M | +| | | | | RegistryResponse | T | M | M | +| | | | | RegistryResponse | R | C | C | + +**Table 6-1 – GCC Primitives and PDUs** + +| Functional unit | Primitives | Term | MCU | Associated PDUs | Dir. | Term | MCU | +|--------------------------|-------------------------------------------|------|-----|------------------------------------|------|----------|----------| +| | GCC-Registry-Retrieve-Entry request | C | C | RegistryRetrieveEntryRequest | T | C | C | +| | | | | RegistryRetrieveEntryRequest | R | M | M | +| | GCC-Registry-Retrieve-Entry confirm | C | C | RegistryResponse | T | M | M | +| | | | | RegistryResponse | R | C | C | +| | GCC-Registry-Delete-Entry request | C | C | RegistryDeleteEntryRequest | T | C | C | +| | | | | RegistryDeleteEntryRequest | R | M | M | +| | GCC-Registry-Delete-Entry confirm | C | C | RegistryResponse | T | M | M | +| | | | | RegistryResponse | R | C | C | +| | GCC-Registry-Monitor request | C | C | RegistryMonitorEntryRequest | T | C | C | +| | | | | RegistryMonitorEntryRequest | R | M | M | +| | GCC-Registry-Monitor indication | C | C | RegistryMonitorEntryIndication | T | M | M | +| | | | | RegistryMonitorEntryIndication | R | C | C | +| | GCC-Registry-Monitor confirm | C | C | RegistryResponse | T | M | M | +| | | | | RegistryResponse | R | C | C | +| | GCC-Registry-Allocate-Handle request | C | C | RegistryAllocateHandleRequest | T | C | C | +| | | | | RegistryAllocateHandleRequest | R | M | M | +| | GCC-Registry-Allocate-Handle confirm | C | C | RegistryAllocateHandleResponse | T | M | M | +| | | | | RegistryAllocateHandleResponse | R | C | C | +| Conference conductorship | GCC-Conductor-Assign request | O | O | – | – | – | – | +| | GCC-Conductor-Assign indication | C | C | ConductorAssignIndication | T | M (Note) | M (Note) | +| | | | | ConductorAssignIndication | R | C | C | +| | GCC-Conductor-Assign confirm | O | O | – | – | – | – | +| | GCC-Conductor-Release request | O | O | ConductorReleaseIndication | T | C | C | +| | | | | ConductorReleaseIndication | R | M (Note) | M (Note) | +| | GCC-Conductor-Release indication | C | C | ConductorReleaseIndication | T | M (Note) | M (Note) | +| | | | | ConductorReleaseIndication | R | C | C | +| | GCC-Conductor-Release confirm | O | O | – | – | – | – | +| | GCC-Conductor-Please request | O | O | – | – | – | – | +| | GCC-Conductor-Please indication | O | O | – | – | – | – | +| | GCC-Conductor-Please confirm | O | O | – | – | – | – | +| | GCC-Conductor-Give request | O | O | – | – | – | – | +| | GCC-Conductor-Give indication | O | O | – | – | – | – | +| | GCC-Conductor-Give response | O | O | ConductorAssignIndication | T | C | C | +| | GCC-Conductor-Give confirm | O | O | – | – | – | – | +| | GCC-Conductor-Inquire request | C | C | – | – | – | – | +| | GCC-Conductor-Inquire confirm | C | C | – | – | – | – | +| | GCC-Conductor-Permission-Ask request | O | O | ConductorPermissionAskIndication | T | C | C | +| | GCC-Conductor-Permission-Ask indication | O | O | ConductorPermissionAskIndication | R | C | C | +| | | O | O | – | – | – | – | +| | GCC-Conductor-Permission-Ask confirm | O | O | – | – | – | – | +| | GCC-Conductor-Permission-Grant request | O | O | ConductorPermissionGrantIndication | T | C | C | +| | GCC-Conductor-Permission-Grant indication | O | O | ConductorPermissionGrantIndication | R | C | C | + +**Table 6-1 – GCC Primitives and PDUs** + +| Functional unit | Primitives | Term | MCU | Associated PDUs | Dir. | Term | MCU | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------|------|-----|-----------------------------------|------|------|-----| +| | GCC-Conductor-Permission-Grant confirm | O | O | – | – | – | – | +| Miscellaneous functions | GCC-Conference-Time-Remaining request | O | O | ConferenceTimeRemainingIndication | T | C | C | +| | GCC-Conference-Time-Remaining indication | O | O | ConferenceTimeRemainingIndication | R | C | C | +| | GCC-Conference-Time-Remaining confirm | O | O | – | – | | | +| | GCC-Conference-Time-Inquire request | O | O | ConferenceTimeInquireIndication | T | C | C | +| | GCC-Conference-Time-Inquire indication | O | O | ConferenceTimeInquireIndication | R | C | C | +| | GCC-Conference-Time-Inquire confirm | O | O | – | – | | | +| | GCC-Conference-Extend request | O | O | ConferenceTimeExtendIndication | T | C | C | +| | GCC-Conference-Extend indication | O | O | ConferenceTimeExtendIndication | R | C | C | +| | GCC-Conference-Extend confirm | O | O | – | – | – | – | +| | GCC-Conference-Assistance request | O | O | ConferenceAssistanceIndication | T | C | C | +| | GCC-Conference-Assistance indication | O | O | ConferenceAssistanceIndication | R | C | C | +| | GCC-Conference-Assistance confirm | O | O | – | – | – | – | +| | GCC-Text-Message request | O | O | TextMessageIndication | T | C | C | +| | GCC-Text-Message indication | O | O | TextMessageIndication | R | C | C | +| | GCC-Text-Message confirm | O | O | – | – | – | – | +| | – | – | – | FunctionNotSupported | T, R | M | M | +| NOTE – Reception of ConductorReleaseIndication PDUs is mandatory to allow the Top GCC Provider to properly handle requests which require privileges. Privileges depend on whether the conference is in conducted or non-conducted mode. Transmission of ConductorAssignIndication and ConductorReleaseIndication PDUs by the Top GCC Provider is mandatory for handling new nodes joining a conference. | | | | | | | | + +# 7 GCC service definition + +## 7.1 Conference establishment and termination + +In this clause, primitives needed for conference establishment and conference termination are described. All of the primitives in this clause are intended for use only by the Node Controller at a terminal or MCU. + +### 7.1.1 The conference profile + +All conferences have the following characteristics which are defined when the conference is created and communicated to each node as it enters the conference. These characteristics remain unchanged for the duration of the conference. This information is collectively referred to as the Conference Profile: + +- *Conference name* – A numerical string and an optional Unicode Row 00 text string identifying the conference. If both forms of Conference Name are used when a conference is created, when that conference is joined, either form may be specified to indicate the conference to be joined. +- *Conference description* – An optional text string to describe the conference. For a listed conference, this string is reproduced in the Conference Descriptor List in response to a GCC-Conference-Query request. +- *Password protected vs. not password protected* – Choice of whether the conference is Password protected or not. + +- *Listed vs. unlisted* – Choice of whether the conference is listed or not listed on the conference list provided when querying the list of available conferences. +- *Conductible vs. non-conductible* – Choice of whether the conference is able to be placed in conducted mode or whether the conference is always non-conducted. +- *Termination method* – Choice of whether conference should last until explicitly terminated (manually terminating), or if it should last until all participants disconnect (automatically terminating). +- *Privilege lists* – A set of lists indicating which privileges, normally only available to the Convener, are also allowed to the Conductor, to any node in a conducted conference, or to any node in a non-conducted conference. +- *Conference Mode* – An optional choice that specifies which categories of nodes will be allowed to join the conference after it is created. If not specified, the conference should default to conventional-only mode. + +### 7.1.2 Description of abstract services + +The following is a list of the primitives defined in this subclause and a brief summary of the function of each: + +- GCC-Conference-Create – Used by the Node Controller to create a new conference, specifying the characteristics of that conference. +- GCC-Conference-Query – Used by the Node Controller to query what conferences are currently in progress as well as the information needed to attempt to join them. +- GCC-Conference-Join – Used by the Node Controller to join an existing conference. +- GCC-Conference-Invite – Used by the Node Controller to invite a node into an existing conference. +- GCC-Conference-Add – Allowed only by the conference convener or convener-designated node; this is used by the Node Controller to request that a node be added to the conference by dialling out from an MCU. +- GCC-Conference-Lock – Allowed only by the conference convener or convener-designated node; this is used by the Node Controller to prevent new participants from joining a conference without being explicitly added. +- GCC-Conference-Unlock – Allowed only by the conference convener or convener-designated node; this is used by the Node Controller to allow new participants to join a conference. +- GCC-Conference-Lock-Report – Provides an indication to the Node Controller that a conference has changed from being locked to being unlocked or vice versa. +- GCC-Conference-Disconnect – Used by a Node Controller to disconnect the local node from an ongoing conference. +- GCC-Conference-Terminate – Allowed only by the conference convener or convener-designated node; this is used by the Node Controller to terminate an entire conference, disconnecting all nodes. +- GCC-Conference-Eject-User – Allowed only by the conference convener or convener-designated node (or by the node directly above the ejected node in the connection hierarchy); this is used by the Node Controller to disconnect a specific node from an ongoing conference. +- GCC-Conference-Transfer – Allowed only by the conference convener or convener-designated node; this is used by the Node Controller to transfer nodes joined with one conference to another conference. This may be used as part of the process of merging or splitting conferences. + +#### 7.1.2.1 GCC-Conference-Create + +The GCC-Conference-Create request primitive is used by a Node Controller to create a new conference at a remote node to which the local node is automatically joined. This primitive may be issued at any time. When a conference is created, the node to which the creation request is directed (the node which receives the GCC-Conference-Create indication) is also automatically joined to the conference and becomes the Top GCC Provider for that conference. This node remains the Top GCC Provider for the conference as long as the conference continues to exist. In some implementations, it may be possible to create a conference locally without the use of GCC primitives. In this case, the node at which the conference is created becomes the Top GCC Provider. Table 7-1 shows the parameters and types of this primitive. Figure 7-1 shows the sequence of events when using this primitive. + +**Table 7-1 – GCC-Conference-Create – Types of primitives and their parameters** + +| Parameter | Request | Indication | Response | Confirm | +|----------------------------------------------|---------|------------|----------|---------| +| Conference Name | M | M(=) | M(=) | M(=) | +| Conference Name Modifier | C | | C | | +| Conference ID | | M | M(=) | M | +| Convener Password | O | O(=) | | | +| Password | O | O(=) | | | +| Conference Locked | M | M(=) | | | +| Conference Listed | M | M(=) | | | +| Conference Conductible | M | M(=) | | | +| Termination Method | M | M(=) | | | +| Conductor Privilege List | O | O(=) | | | +| Conducted-mode Conference Privilege List | O | O(=) | | | +| Non-conducted-mode Conference Privilege List | O | O(=) | | | +| Conference Description | O | O(=) | | | +| Caller Identifier | O | O(=) | | | +| Calling Address | O | O(=) | | | +| Called Address | O | O | | | +| Domain Parameters | M | M | M | M(=) | +| Quality of Service | M | M | M | M(=) | +| Local Network Address | O | | O | | +| Conference Priority | O | O(=) | | | +| Conference Mode | O | O(=) | | | +| User Data | O | O(=) | O | O(=) | +| Result | | | M | M(=) | + +*Conference Name*: Name by which the conference to be created is identified. This consists of a numerical string along with an optional Unicode Row 00 text string, from zero to 255 characters each. If both forms of a Conference Name are used, if a node wishes to join this conference, it may specify either form of the name in the join request. In the join request, a numeric value will necessarily be included in numeric variant of the Conference Name. As a result, use of a text Conference Name including only numeric characters will never be compared against and therefore + +should not be used – that is, the text variant of the Conference Name should include at least one non-numeric character. + +*Conference Name Modifier:* If the requesting or responding node is already joined to a conference with the same Conference Name (either numerical or text portion) as that included in the request, this parameter shall also be included in the corresponding request or response primitive. The value of this parameter shall be unique among all conferences at the corresponding node which have this Conference Name. This modifier, if included, shall be used as the Called Node Conference Name Modifier parameter in a GCC-Conference-Join request by another node attempting to join the conference through a direct connection with the corresponding node. This modifier is also included in the response to a GCC-Conference-Query directed at this node. This parameter is a numerical string up to 255 digits in length. + +*Conference ID:* Locally-allocated identifier of the newly-created conference. All subsequent references to the conference are made using the Conference ID as a unique identifier. The Conference ID shall be identical with the MCS Domain Selector used locally to identify the MCS Domain associated with the conference. + +*Convener Password:* This optional parameter contains a numeric string, as well as an optional Unicode Row 00 text string, used for the convener to identify itself in later operations, allowing the convener to disconnect and later rejoin the conference, maintaining convener privileges (only when rejoined with a direct connection to the Top GCC Provider). This is the private password which will allow the convener to perform convener-only operations (maximum 255 digits and 255 characters). If this parameter is NULL, then it is not possible for the convener to disconnect and later rejoin maintaining convener privileges. In the join request, a numeric value will necessarily be included in the numeric variant of the Convener Password. As a result, use of a text Convener Password including only numeric characters will never be compared against and therefore should not be used – that is, the text variant of the Convener Password should include at least one non-numeric character. + +*Password:* This is a numeric string, as well as an optional Unicode Row 00 text string, to serve as a Password to enter the conference (maximum 255 digits and 255 characters). If no Password is specified, the conference is not Password protected. In the join request, a numeric value will necessarily be included in the numeric variant of the Password. As a result, use of a text Password including only numeric characters will never be compared against and therefore should not be used – that is, the text variant of the Password should include at least one non-numeric character. + +NOTE – If the conference is Password protected, the Node controller must specify a numeric Password, and may also specify a text Password. The numeric Password is required to allow for nodes which have no suitable text entry mechanism. In the case that a text password is used, there is no assumption that the numeric Password that must also be included is generated by the user. It may be more convenient and secure to use a machine generated numeric Password. + +*Conference Locked:* Setting this flag immediately locks a conference, preventing anyone from joining this conference unless they are explicitly added using the GCC-Conference-Invite primitive (or indirectly inviting via the GCC-Conference-Add primitive). To lock a conference at any time after issuing this primitive, the primitive GCC-Conference-Lock may be used. To unlock a conference, GCC-Conference-Unlock may be used. + +*Conference Listed:* The TRUE setting of this flag indicates that this conference may be listed when using the conference-query facility. The FALSE setting of this flag indicates that this conference shall not be listed. + +*Conference Conductible:* The TRUE setting of this flag indicates that this conference may be placed in conducted mode using the GCC-Conductor-Assign primitive. The FALSE setting of this flag indicates that this conference shall be non-conducted only, and attempts to assign a conductor shall be rejected. + +*Termination Method:* This parameter indicates whether the conference shall remain in existence until explicitly terminated by the Convener or convener-designated node using the GCC-Conference-Terminate primitive (manually terminating), or if the conference will terminate when there are no nodes joined to it or if explicitly terminated (automatically terminating). + +*Conductor Privilege List:* This is a list of flags indicating which functions the convener is designating as allowable to be used by the conference conductor, if any. The flags in this list correspond to the operations: GCC-Conference-Terminate, GCC-Conference-Eject-User, GCC-Conference-Add, GCC-Conference-Lock, GCC-Conference-Unlock and GCC-Conference-Transfer. + +*Conducted-mode Conference Privilege List:* This is a list of flags indicating which functions the convener is designating as allowable to be used by any node in a conducted-mode conference. The flags in this list correspond to the same operations as for the above parameter. + +*Non-conducted-mode Conference Privilege List:* This is a list of flags indicating which functions the convener is designating as allowable to be used by any node in a non-conducted-mode conference. The flags in this list correspond to the same operations as for the above parameter. + +*Conference Description:* An optional Unicode text string, up to 255 characters in length, which may be used to describe the conference. This string is maintained by the GCC Providers in the conference to use as part of the response to GCC-Conference-Query requests. + +*Caller Identifier:* Optional Unicode text string (maximum 255 characters) which may be used to identify the calling node to the node at which the conference is to be created. The use of this information at this node is beyond the scope of this Recommendation. It may be used, for example, to allow a user at that node to select among a limited set of participants which are allowed to create conferences. Because this string can be set to any value, it does not necessarily add to the security of a conference to do this, however. + +*Calling Address:* Optional address to be included in the MCS-Connect-Provider primitive on establishing an MCS connection. See [ITU-T T.122] for the interpretation of this parameter. + +*Called Address:* Optional address to be included in the MCS-Connect-Provider primitive on establishing an MCS connection. See [ITU-T T.122] for the interpretation of this parameter. + +*Domain Parameters:* Domain parameters to be included in the MCS-Connect-Provider primitive on establishing an MCS connection. See [ITU-T T.122] for the interpretation of this parameter. + +*Quality of Service:* Quality of Service parameters to be included in the MCS-Connect-Provider primitive on establishing an MCS connection. See [ITU-T T.122] for the interpretation of this parameter. + +*Local Network Address:* If included in either the request or response, the local GCC Provider at the corresponding node shall use this information to include as the Network Address parameter in the Conference Descriptor List sent as part of the response to a GCC-Conference-Query request from another node. In the GCC protocol, this parameter is reflected by ASN.1 structures NetworkAddress and NetworkAddressV2. See Annex B for the description and use of these. + +*Conference Priority:* An optional parameter to specify the priority of a conference. This may be used in some situations to determine whether or not the indication should be accepted. The parameter includes two subparameters: the priority and the scheme. The priority is an integer value ranging from zero to 65535. The scheme indicates the procedures by which the priority value is to be interpreted. At this time, only non-standard schemes are supported. Standardized procedures for interpretation of this parameter are for further study. + +*Conference Mode:* An optional parameter used to specify the mode of a conference. This parameter is used by GCC and the Node Controller at the Top GCC Provider to determine which Node Categories a joining node must fall into before being allowed to join the conference. Conference + +Modes include the following: *conventional-only*, which allows only Conventional nodes to join the conference; *counted-controlled*, which allows only Counted and Conventional nodes to join the conference; *anonymous-controlled*, which allows only Anonymous and Conventional nodes to join the conference; and *unrestricted-mode*, which allows all three node categories to participate in the conference. Note that Conventional nodes wishing to join either a counted-controlled or an anonymous-controlled conference must specify a password upon joining. + +*User Data*: Optional user data which may be used for functions outside the scope of this Recommendation such as authentication, billing, etc. + +*Result*: An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, user rejected, resources not available, rejected for symmetry-breaking, locked conference not supported, Conference Name and Conference Name Modifier already exist, domain parameters unacceptable, domain not hierarchical, lower-layer initiated disconnect, unspecified failure to connect. A negative result in the GCC-Conference-Create confirm does not imply that the physical connection to the node to which the connection was being attempted is disconnected. + +![Sequence diagram for GCC-Conference-Create showing interactions between Node Controller, GCC Provider, and Top GCC Provider.](9c1d3678db4a12d5864cb2a4def1135d_img.jpg) + +``` + +sequenceDiagram + participant NC1 as Node Controller + participant GP as GCC Provider + participant TGP as Top GCC Provider + participant NC2 as Node Controller + + NC1->>GP: GCC-Conference-Create request + GP-->>TGP: + TGP->>NC2: GCC-Conference-Create indication + NC2->>TGP: + TGP-->>GP: GCC-Conference-Create response + GP->>NC1: GCC-Conference-Create confirm + +``` + +The diagram illustrates the sequence of primitives for the GCC-Conference-Create operation. It involves four entities: a Node Controller on the left, a GCC Provider, a Top GCC Provider, and another Node Controller on the right. The process begins with the left Node Controller sending a 'GCC-Conference-Create request' to the GCC Provider. A dashed line indicates a message passing from the GCC Provider to the Top GCC Provider. The Top GCC Provider then sends a 'GCC-Conference-Create indication' to the right Node Controller. A second dashed line shows a message from the right Node Controller back to the Top GCC Provider. The Top GCC Provider then sends a 'GCC-Conference-Create response' back to the GCC Provider, and finally, the GCC Provider sends a 'GCC-Conference-Create confirm' back to the left Node Controller. + +T.124(01-07)\_F7-01 + +Sequence diagram for GCC-Conference-Create showing interactions between Node Controller, GCC Provider, and Top GCC Provider. + +**Figure 7-1 – GCC-Conference-Create – Sequence of primitives** + +#### 7.1.2.2 GCC-Conference-Query + +The GCC-Conference-Query request primitive may be used by a Node Controller to determine what conferences are currently in existence at a particular MCU. Table 7-2 shows the parameters and types of this primitive. Figure 7-2 shows the sequence of events when using this primitive. + +**Table 7-2 – GCC-Conference-Query – Types of primitives and their parameters** + +| Parameter | Request | Indication | Response | Confirm | +|-----------------------------|---------|------------|----------|---------| +| Node Type | M | M(=) | M | M(=) | +| Asymmetry Indicator | C | C(=) | C | C(=) | +| Conference Descriptor List | | | | C | +| Wait for Invitation Flag | | | O | O | +| No Unlisted Conference Flag | | | O | O | +| Calling Address | O | O(=) | | | +| Called Address | O | O | | | +| User Data | O | O(=) | O | O(=) | +| Result | | | M | M(=) | + +![Sequence diagram showing the GCC-Conference-Query sequence of primitives between a Node Controller and two GCC Providers.](dcb5711d118ae6753b0e12f86eda37db_img.jpg) + +``` + +sequenceDiagram + participant NC1 as Node Controller + participant GP1 as GCC Provider + participant GP2 as GCC Provider + participant NC2 as Node Controller + + NC1->>GP1: GCC-Conference-Query request + GP1-->>GP2: GCC-Conference-Query indication + GP2->>NC2: GCC-Conference-Query response + NC2-->>GP1: GCC-Conference-Query confirm + +``` + +The diagram illustrates the sequence of primitives for the GCC-Conference-Query. It involves four entities: a Node Controller on the left, two GCC Providers in the middle, and another Node Controller on the right. The sequence is as follows: 1. The left Node Controller sends a 'GCC-Conference-Query request' to the first GCC Provider. 2. The first GCC Provider sends a 'GCC-Conference-Query indication' to the second GCC Provider. 3. The second GCC Provider sends a 'GCC-Conference-Query response' to the right Node Controller. 4. The right Node Controller sends a 'GCC-Conference-Query confirm' back to the first GCC Provider. Vertical lines represent the lifelines of each entity, and arrows indicate the direction of the message flows. + +Sequence diagram showing the GCC-Conference-Query sequence of primitives between a Node Controller and two GCC Providers. + +T.124(07-07)\_F7-02 + +**Figure 7-2 – GCC-Conference-Query – Sequence of primitives** + +*Node Type:* The node type is either terminal, MCU, or multiport terminal. + +*Asymmetry Indicator:* This is a field which is needed for certain conference establishment procedures which require knowledge of which node across a single connection was the calling node (the initiator of the physical connection), and which is the called node. This parameter is required in the case of a physical connection between the two nodes (that is, an underlying connection between the two nodes using the PSTN, ISDN, or CSDN cases of [ITU-T T.123]). Otherwise, this parameter is optional. If a node is aware of its status as the calling or called node, it shall set this indicator to the proper value. In some cases a node may not be certain whether it is the calling or called node. In this case, this parameter shall include a 32-bit random number. If both nodes indicate that they are not certain of their status, the random numbers are used to determine which node should be considered the calling node and which the called node for the purposes of the conference establishment procedure (note that this may not correctly reflect the true calling or called node). The node which transmitted the largest of the two random numbers shall be considered the calling node for the purpose of the conference establishment procedure. If both random numbers are identical, this decision shall be considered unsatisfied and the requester shall re-issue the GCC-Conference-Query request using a different random number (a different random number shall also be used in the resulting response). If both nodes respond with actual values for this parameter (indicating knowledge of whether they are the called or calling node), but the resulting exchange indicates a disagreement (i.e., both think they are the calling node or both think they are the called node), this decision shall also be considered + +unsatisfied and the requester shall re-issue the GCC-Conference-Query request using a random number (the response shall also use a random number). During the period where a query request remains unconfirmed on one side of a given connection, the value for this parameter in all query requests and query responses issued by this node over the same physical connection shall remain unchanged. The random numbers should be generated to be uniformly distributed over the entire numerical range. + +*Conference Descriptor List:* A variable length list of conference descriptors each indicating an active conference available to be joined. This list does not include conferences which had been designated unlisted at their time of creation. If there are no available conferences, the list contains zero entries. Each conference descriptor includes the parameters shown in Table 7-3. + +*Calling Address:* Optional address to be included in the MCS-Connect-Provider primitive on establishing an MCS connection. + +*Called Address:* Optional address to be included in the MCS-Connect-Provider primitive on establishing an MCS connection. + +*User Data:* Optional user data which may be used for functions outside the scope of this Recommendation such as authentication, billing, etc. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, user-rejected, domain parameters unacceptable, domain not hierarchical, lower-layer initiated disconnect, unspecified failure to connect. + +**Table 7-3 – Contents of a Conference Descriptor** + +| Parameter | Description | +|----------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Conference Name | Conference Name of the conference. If the requesting node wishes to join this conference, this parameter is the value that shall be used in the Conference Name parameter of the GCC-Conference-Join request. This parameter is a numerical string along with an optional Unicode Row 00 text string, maximum 255 characters each. If both forms of the name are given, either form may be specified in the join request. | +| Conference Name Modifier (conditional) | If at the node returning the response, the conference is known by a name which includes a Conference Name Modifier, this parameter is included. If the requesting node wishes to join this conference, this is the Conference Name Modifier that shall be used in the Called Node Conference Name Modifier parameter of the GCC-Conference-Join request. This parameter is a numerical string up to 255 digits in length. | +| Conference Description (conditional) | An optional Unicode text string, up to 255 characters in length, used to describe the conference. This parameter may be particularly useful in cases where more than one conference in the Conference Descriptor List has the same Conference Name as a means of distinguishing between these conferences. | +| Locked/Unlocked | Flag indicating whether the conference is currently locked or unlocked. | +| Password In The Clear Required | Indicates that the conference is password protected with a password that may be used without encryption in a GCC-Conference-Join request without first being challenged for the password. | + +**Table 7-3 – Contents of a Conference Descriptor** + +| Parameter | Description | +|-------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Network Address (conditional) | Address information provided to the requesting node. This is provided only if the optional Local Network Address parameter had been included in the connection establishment primitive at that node (either GCC-Conference-Create, GCC-Conference-Join, or GCC-Conference-Invite). In the GCC protocol, this parameter is reflected by ASN.1 structures NetworkAddress and NetworkAddressV2. See Annex B for the description and use of these. | +| Default Conference Flag | An optional flag indicating whether a particular conference should be considered the default conference to join. In a meet-me conference where the user is expected to manually choose a conference to join from a list, this parameter should be FALSE for all conferences. In a meet-me conference where a priori information allows an MCU to determine which conference should be joined (and security reasons, for example, preclude the use of GCC-Conference-Invite), this flag may be set to TRUE for one and only one conference. If this flag is TRUE for more than one conference, or is TRUE for a Locked conference, it should be ignored by the receiver. | +| Conference Mode | An optional parameter used to specify the mode of a conference. This parameter can be used to determine the appropriate Node Category to specify when joining the conference. | + +*Wait for Invitation Flag*: Optional flag that may be set by an MCU. When TRUE this flag indicates that the receiving Node should wait to receive an invitation to a conference and need not attempt to join or create a conference. The absence of this flag, or a FALSE value, does not imply whether or not attempts to join or create a conference should be made. This flag shall not be set to TRUE by a terminal or multiport terminal. No time-limit is implied by a TRUE value for this flag. A node wishing to determine whether the MCU continues to intend it to wait for the invitation may re-issue a GCC-Conference-Query request in order to receive the current setting of this flag in the confirm. + +*No Unlisted Conference Flag*: Optional flag that when TRUE indicates that there are no unlisted conferences available to be joined. Absence of this flag, or a FALSE value, does not imply any information as to whether or not unlisted conferences are available. + +#### 7.1.2.3 GCC-Conference-Join + +The GCC-Conference-Join request primitive may be used by the Node Controller to cause the local node to join an existing conference. This primitive may be issued at any time. A node may be joined to more than one conference simultaneously. If the conference is Password protected, the Password parameter must contain the correct information for the conference join to be successful. Table 7-4 shows the parameters and types of this primitive. Figure 7-3 shows the sequence of events when using this primitive. + +NOTE – It is up to the Node Controller, not the Top GCC Provider, to determine if the Password is correct. It is possible that its definition of correct may be less stringent than a strict character-by-character match. For example, in the case of the text form of a Password, the Node Controller may choose to use a case-insensitive matching criterion. + +**Table 7-4 – GCC-Conference-Join – Types of primitives and their parameters** + +| Parameter | Request | Indication | Response | Confirm | +|----------------------------------------------|---------|------------|----------|---------| +| Conference Name | M | | | M | +| Called Node Conference Name Modifier | C | | | C(=RQ) | +| Calling Node Conference Name Modifier | C | | | C(=RQ) | +| Conference ID | | M | M(=) | M | +| Convener Password | O | O(=) | | | +| Password | C | C(=) | C | C(=) | +| Caller Identifier | O | O(=) | | | +| Calling Address | O | C(=) | | | +| Called Address | O | C | | | +| Domain Parameters | M | | | M | +| Quality of Service | M | | | M | +| Password In The Clear Required | | | | M | +| Conference Locked | | | | M | +| Conference Listed | | | | M | +| Conference Conductible | | | | M | +| Termination Method | | | | M | +| Conductor Privilege List | | | | C | +| Conducted-mode Conference Privilege List | | | | C | +| Non-conducted-mode Conference Privilege List | | | | C | +| Conference Description | | | | C | +| Local Network Address | O | | | | +| Node Category | O | O(=) | O | O(=) | +| Conference Mode | | | O | O(=) | +| User Data | O | O(=) | O | O(=) | +| Result | | | M | M(=) | + +*Conference Name:* Name of the conference being joined. In the request, this parameter is either a numeric string or a Unicode Row 00 text string, maximum 255 characters. If both the numeric and text parts of the Conference Name were used at the time the conference was created, the Node Controller shall determine whether to send the Conference Name as a text string or numeric string based on its value. A value consisting only of numeric digits shall be specified as a numeric string, while a value including at least one non-numeric character shall be specified as a text string. In the confirm, this parameter includes the full Conference Name including both numerical and text forms, if both were used at the time the conference was created. + +*Called Node Conference Name Modifier:* If the node directly connected to the joining node (the node to which a connection is attempting to be established) has included a Conference Name Modifier as part of the name by which this conference is known, this parameter shall be included in the request primitive and shall indicate the Conference Name Modifier as it is known to the node directly connected to the joining node. This parameter is a numeric string up to 255 digits in length. + +*Calling Node Conference Name Modifier:* If a conference already exists at the node issuing the join request with a name identical with the Conference Name of the conference to be joined, this + +parameter shall be included in the GCC-Conference-Join request and shall indicate the Conference Name Modifier by which the conference shall be known at the local node. This parameter, if included, shall be different from any Conference Name Modifier already in use for any other conference the local node is currently joined to with the same Conference Name. If used, this parameter becomes the Called Node Conference Name Modifier by which another node attempting to join this conference through a connection to the local node refers to this conference. This modifier is also included as the Conference Name Modifier parameter in any GCC-Conference-Query response from this node (if the conference is listed). This parameter is a numeric string up to 255 digits in length. + +*Conference ID:* At the Top GCC Provider (the indication/response primitives), this parameter is the Conference ID of the conference to which the requesting node wishes to join. In the confirm primitive, this parameter is returned by GCC indicating the locally allocated ID by which all subsequent references to the conference are indicated. The Conference ID shall be identical with the MCS Domain Selector used locally to identify the MCS Domain associated with the conference. + +*Convener Password:* This is an optional parameter which is either a numeric string or a Unicode Row 00 text string which may be used by a conference convener rejoining a conference after disconnecting (maximum 255 digits or characters). If this identifier matches the corresponding identifier used when the conference was created, the joining node is given the privileges of the convener, but only if joining with a direct connection to the Top GCC Provider (rather than via an intermediate MCU). The convener, with the correct Convener Password, is allowed to join even conferences which are locked. If the conference is Password protected, the correct Password must be given in addition to the Convener Password to successfully join the conference. If the Convener Password is present but does not match, the request to join shall be rejected. The criterion used to determine if the Convener Password matches the originally specified value is determined by the Node Controller. The Node Controller shall determine whether to send the Convener Password as a text string or numeric string based on its value. A value consisting only of numeric digits shall be specified as a numeric string, while a value including at least one non-numeric character shall be specified as a text string. + +*Password:* The password parameter is used to gain access to a password protected conference. In the request form of this primitive, this parameter shall only contain a password if a result of Challenge Response Required has been received in a previous GCC-Conference-Join confirm for this conference or if the Password In The Clear Required parameter is set in the Conference Descriptor for this conference in a previous GCC-Conference-Query confirm. In the case of a Password In The Clear, this is either a numeric string or a Unicode Row 00 text string (maximum 255 digits or characters). A text string may only be used if a text password was defined at the time of conference creation in addition to the numeric password. The Node Controller shall determine whether to send the Password as a text string or numeric string based on its value. A value consisting only of numeric digits shall be specified as a numeric string, while a value including at least one non-numeric character shall be specified as a text string. In the case of an encrypted password, this parameter contains the password encoded using one of the algorithms specified in the previously received challenge. In the case of a password sent in response to a challenge (either in the clear or encrypted), this parameter shall also include a tag which shall be identical to the tag received in the challenge. In the case of a password initiated in response to the Password In The Clear Required flag in the GCC-Conference-Query indication, no tag is required. In the request form of this primitive, this parameter may also include a challenge to the receiving node. There are no restrictions on when a challenge may be included in this parameter. + +In the response form of this primitive, this parameter may contain a challenge to the requester indicating that a password is required for joining this conference. For this case, this parameter includes information specifying which forms of the password will be accepted (either in the clear, and/or encrypted via a list of non-standard encryption algorithms), an integer tag used to identify this challenge, and any additional information required for encryption. Should this parameter contain + +challenge, the result parameter of this primitive shall be set to Challenge Response Required. In this case, no connection is established by this exchange. This parameter in the response form of this primitive may also include a Password (either in the clear or encrypted) in response to a challenge by the requesting node. + +If this parameter in the indication is not in a format satisfactory to the receiving node, that node should issue a response with Invalid Challenge Response as the result. If this parameter in the indication is of the correct format, but does not contain the correct password, the response should include Invalid Password as the result. + +*Caller Identifier:* Optional Unicode text string (maximum 255 characters) which may be used to identify the calling node to the node at which the Top GCC Provider resides. The use of this information at this node is beyond the scope of this Recommendation. It may be used, for example, to allow a user at that node to select among a limited set of participants to allow into the conference. Because this string can be set to any value, it does not necessarily add to the security of a conference to do this, however. + +*Calling Address:* Optional address to be included in the MCS-Connect-Provider primitive on establishing an MCS connection. See [ITU-T T.122] for the interpretation of this parameter. The presence of this parameter in the indication is conditional. It is present only when the Node initiating the GCC-Conference-Join request is attempting to establish a direct connection to the Node containing the Top GCC Provider for the conference being joined. + +*Called Address:* Optional address to be included in the MCS-Connect-Provider primitive on establishing an MCS connection. See [ITU-T T.122] for the interpretation of this parameter. The presence of this parameter in the indication is conditional. It is present only when the Node initiating the GCC-Conference-Join request is attempting to establish a direct connection to the Node containing the Top GCC Provider for the conference being joined. + +*Domain Parameters:* Domain parameters to be included in the MCS-Connect-Provider primitive on establishing an MCS connection. See [ITU-T T.122] for the interpretation of this parameter. + +*Quality of Service:* Quality of Service parameters to be included in the MCS-Connect-Provider primitive on establishing an MCS connection. See [ITU-T T.122] for the interpretation of this parameter. + +*Password In The Clear Required:* This is a Boolean parameter that indicates that the conference is password protected with a password that may be used without encryption in a GCC-Conference-Join request without first being challenged for the password. If the joining node is an MCU, this information is used by the GCC Provider in generating the response to a GCC-Conference-Query indication. This information shall be used by the Node Controller in determining whether or not the Password parameter may be included in a GCC-Conference-Transfer request. + +*Conference Locked:* This flag indicates whether or not the joined conference is locked or unlocked. If the joining node is an MCU, this information shall be used in generating the response to a GCC-Conference-Query indication. + +*Conference Listed:* This flag indicates whether or not the joined conference is listed or unlisted. If the joining node is an MCU, this information shall be used in generating the response to a GCC-Conference-Query indication. In particular, conferences which are indicated as being unlisted shall not be listed in the conference list provided with the GCC-Conference-Query response. + +*Conference Conductible:* The TRUE setting of this flag indicates that this conference may be placed in conducted mode using the GCC-Conductor-Assign primitive. The FALSE setting of this flag indicates that this conference shall be non-conducted only, and attempts to assign a conductor shall be rejected. + +*Termination Method:* This flag indicates the termination rule for the joined conference. The conference may be either manually or automatically terminating. + +*Conductor Privilege List:* This is a list of flags indicating which functions the convener has designated as allowable to be used by the conference conductor, if any. The flags in this list correspond to the operations: GCC-Conference-Terminate, GCC-Conference-Eject-User, GCC-Conference-Add, GCC-Conference-Lock, GCC-Conference-Unlock and GCC-Conference-Transfer. + +*Conducted-mode Conference Privilege List:* This is a list of flags indicating which functions the convener has designated as allowable to be used by any node in a conducted-mode conference. The flags in this list correspond to the same operations as for the above parameter. + +*Non-conducted-mode Conference Privilege List:* This is a list of flags indicating which functions the convener has designated as allowable to be used by any node in a non-conducted-mode conference. The flags in this list correspond to the same operations as for the above parameter. + +*Conference Description:* This parameter is a Unicode text string, up to 255 characters in length, describing the conference being joined. It is present in the confirm primitive only if included at the time of conference creation. + +*Local Network Address:* If included in the request, the local GCC Provider at the corresponding node shall use this information to include as the Network Address parameter in the Conference Descriptor List sent as part of the response to a GCC-Conference-Query request from another node. In the GCC protocol, this parameter is reflected by ASN.1 structures NetworkAddress and NetworkAddressV2. See Annex B for the description and use of these. + +*Node Category:* If included in the request, the local GCC Provider at the node being joined can use this to determine the joining node's preferred node category. This may be overridden in the join response if the suggested category is not acceptable by the node being joined. If not specified, the default requested category is Conventional. + +*Conference Mode:* An optional parameter used to specify the mode of a conference. This parameter informs the joining node which Node Categories are allowed to participate in the conference. Conference Modes include: *conventional-only*, which allows only Conventional nodes to join the conference; *counted-controlled*, which allows only Counted and Conventional nodes to join the conference; *anonymous-controlled*, which allows only Anonymous and Conventional nodes to join the conference; and *unrestricted-mode*, which allows all three node categories to participate in the conference. Note that Conventional nodes wishing to join either a counted-controlled or an anonymous-controlled conference must specify a password upon joining. + +*User Data:* Optional user data which may be used for functions outside the scope of this Recommendation such as authentication, billing, etc. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, user-rejected, invalid conference, invalid Password, Challenge Response required, invalid Challenge Response, invalid Convener Password, domain parameters unacceptable, domain not hierarchical, lower-layer initiated disconnect, unspecified failure to connect. A negative result in the GCC-Conference-Join confirm does not imply that the physical connection to the node to which the connection was being attempted is disconnected. + +![Sequence diagram for GCC-Conference-Join showing interactions between Node Controller, GCC Provider, and Top GCC Provider.](e451401f8fa77b466f401d5fce15b26c_img.jpg) + +``` + +sequenceDiagram + participant NC1 as Node Controller + participant GP as GCC Provider + participant TGP as Top GCC Provider + participant NC2 as Node Controller + + NC1->>GP: GCC-Conference-Join request + GP-->>TGP: + TGP->>NC2: GCC-Conference-Join indication + NC2->>TGP: GCC-Conference-Join response + TGP-->>GP: + GP->>NC1: GCC-Conference-Join confirm + +``` + +T.124(01-07)\_F7-03 + +Sequence diagram for GCC-Conference-Join showing interactions between Node Controller, GCC Provider, and Top GCC Provider. + +**Figure 7-3 – GCC-Conference-Join – Sequence of primitives** + +#### 7.1.2.4 GCC-Conference-Invite + +The GCC-Conference-Invite request primitive may be used by a Node Controller to invite a node to join a conference. This primitive may be used as a result of GCC-Conference-Add indication, or may be issued directly by the inviting node. If the add is successful, the adding MCU invites the added node to join the conference by issuing the GCC-Conference-Invite request primitive. Note that even if the conference is Password protected, no Password is needed by the invited node in order to accept the invitation to join the conference. Table 7-5 shows the parameters and types of this primitive. Figure 7-4 shows the sequence of events when using this primitive. + +**Table 7-5 – CC-Conference-Invite – Types of primitives and their parameters** + +| Parameter | Request | Indication | Response | Confirm | +|----------------------------------------------|---------|------------|----------|---------| +| Conference ID | M | M | M(=IN) | M(=RQ) | +| Conference Name | | M | | | +| Conference Name Modifier | | | C | | +| Caller Identifier | O | O(=) | | | +| Calling Address | O | O(=) | | | +| Called Address | O | O | | | +| Domain Parameters | | M | M | | +| Quality of Service | | M | M | | +| Password In The Clear Required | | M | | | +| Conference Locked | | M | | | +| Conference Listed | | M | | | +| Conference Conductible | | M | | | +| Termination Method | | M | | | +| Conductor Privilege List | | C | | | +| Conducted-mode Conference Privilege List | | C | | | +| Non-conducted-mode Conference Privilege List | | C | | | +| Conference Description | | C | | | +| Local Network Address | | | O | | + +**Table 7-5 – CC-Conference-Invite – Types of primitives and their parameters** + +| Parameter | Request | Indication | Response | Confirm | +|---------------------|---------|------------|----------|---------| +| Conference Priority | O | O(=) | | | +| Node Category | O | O(=) | | | +| Conference Mode | O | O(=) | | | +| User Data | O | O(=) | O | O(=) | +| Result | | | M | M(=) | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Conference Name*: The name of the conference as specified in the Conference Profile. If the Conference Name includes both numerical and text forms, both forms shall be included in this parameter. + +*Conference Name Modifier*: If a conference already exists at the node issuing the invite response with a name identical with the Conference Name of the conference to be joined, this parameter shall be included in the GCC-Conference-Invite response and shall indicate the Conference Name Modifier by which the conference shall be known at the local node. This parameter, if included, shall be different from any Conference Name Modifier already in use for any other conference the local node is currently joined to with the same Conference Name. If used, this parameter becomes the Calling Node Conference Name Modifier by which another node attempting to join this conference through a connection to the local node refers to this conference. This name is also included as the Conference Name Modifier parameter in any GCC-Conference-Query response from this node (if the conference is listed). This is a numerical string up to 255 digits in length. + +*Caller Identifier*: Optional Unicode text string (maximum 255 characters) which may be used to identify the calling node to the node at which the conference is to be created. The use of this information at this node is beyond the scope of this Recommendation. It may be used, for example, to allow a user at that node to select among a limited set of participants which are allowed to invite this node into a conference. Because this string can be set to any value, it does not necessarily add to the security of a conference to do this, however. + +*Calling Address*: Optional address to be included in the MCS-Connect-Provider primitive on establishing an MCS connection. See [ITU-T T.122] for the interpretation of this parameter. + +*Called Address*: Optional address to be included in the MCS-Connect-Provider primitive on establishing an MCS connection. See [ITU-T T.122] for the interpretation of this parameter. + +*Domain Parameters*: Domain parameters to be included in the MCS-Connect-Provider primitive on establishing an MCS connection. See [ITU-T T.122] for the interpretation of this parameter. + +*Quality of Service*: Quality of Service parameters to be included in the MCS-Connect-Provider primitive on establishing an MCS connection. See [ITU-T T.122] for the interpretation of this parameter. + +*Password In The Clear Required*: This is a Boolean parameter that indicates that the conference is password protected with a password that may be used without encryption in a GCC-Conference-Join request without first being challenged for the password. If the joining node is an MCU, this information is used by the GCC Provider in generating the response to a GCC-Conference-Query indication. This information shall be used by the Node Controller in determining whether or not the Password parameter may be included in a GCC-Conference-Transfer request. + +*Conference Locked:* This flag indicates whether or not the joined conference is locked or unlocked. If the joining node is an MCU, this information shall be used in generating the response to a GCC-Conference-Query indication. + +*Conference Listed:* This flag indicates whether or not the joined conference is listed or unlisted. If the joining node is an MCU, this information shall be used in generating the response to a GCC-Conference-Query indication. In particular, conferences which are indicated as being unlisted shall not be listed in the conference list provided with the GCC-Conference-Query response. + +*Conference Conductible:* The TRUE setting of this flag indicates that this conference may be placed in conducted mode using the GCC-Conductor-Assign primitive. The FALSE setting of this flag indicates that this conference shall be non-conducted only, and attempts to assign a conductor shall be rejected. + +*Termination Method:* This flag indicates the termination rule for the joined conference. The conference may be either manually or automatically terminating. + +*Conductor Privilege List:* This is a list of flags indicating which functions the convener has designated as allowable to be used by the conference conductor, if any. The flags in this list correspond to the operations: GCC-Conference-Terminate, GCC-Conference-Eject-User, GCC-Conference-Add, GCC-Conference-Lock, GCC-Conference-Unlock and GCC-Conference-Transfer. + +*Conducted-mode Conference Privilege List:* This is a list of flags indicating which functions the convener has designated as allowable to be used by any node in a conducted-mode conference. The flags in this list correspond to the same operations as for the above parameter. + +*Non-conducted-mode Conference Privilege List:* This is a list of flags indicating which functions the convener has designated as allowable to be used by any node in a non-conducted-mode conference. The flags in this list correspond to the same operations as for the above parameter. + +*Conference Description:* This parameter is a Unicode text string, up to 255 characters in length, describing the conference. It is present in the confirm primitive only if included at the time of conference creation. + +*Local Network Address:* If included in the response, the local GCC Provider at the corresponding node shall use this information to include as the Network Address parameter in the Conference Descriptor List sent as part of the response to a GCC-Conference-Query request from another node. In the GCC protocol, this parameter is reflected by ASN.1 structures NetworkAddress and NetworkAddressV2. See Annex B for the description and use of these. + +*Conference Priority:* An optional parameter to specify the priority of a conference. This may be used in some situations to determine whether or not the indication should be accepted. The parameter includes two subparameters: the priority and the scheme. The priority is an integer value ranging from zero to 65535. The scheme indicates the procedures by which the priority value is to be interpreted. At this time, only non-standard schemes are supported. Standardized procedures for interpretation of this parameter are for further study. + +*Node Category:* This informs the node that is being invited of the node category into which it falls. The invited node has no say in this selection. The invite should fail when an older protocol node that does not understand Node Categories is invited. When this occurs, the result should state that the node category parameter was unacceptable. + +*Conference Mode:* An optional parameter used to specify the mode of a conference. This parameter informs the invited node which Node Categories are allowed to participate in the conference. Conference Modes include: *conventional-only*, which allows only Conventional nodes to join the conference; *counted-controlled*, which allows only Counted and Conventional nodes to join the conference; *anonymous-controlled*, which allows only Anonymous and Conventional nodes to join the conference; and *unrestricted-mode*, which allows all three node categories to participate in the + +conference. Note that Conventional nodes wishing to join either a counted-controlled or an anonymous-controlled conference must specify a password upon joining. + +*User Data:* Optional user data which may be used for functions outside the scope of this Recommendation such as authentication, billing, etc. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, user rejected, invalid conference, domain parameters unacceptable, domain not hierarchical, lower-layer initiated disconnect, unspecified failure to connect and, node category unacceptable. A negative result in the GCC-Conference-Invite confirm does not imply that the physical connection to the node to which the connection was being attempted is disconnected. + +![Sequence diagram showing the GCC-Conference-Invite process between an Inviting MCU Node Controller, two GCC Providers, and an Invited Node Node Controller.](9f6dec4d4e9fde40bce018861ef1278e_img.jpg) + +``` + +sequenceDiagram + participant MCU as Inviting MCU +Node Controller + participant GP1 as GCC Provider + participant GP2 as GCC Provider + participant Node as Invited Node +Node Controller + + MCU->>GP1: GCC-Conference-Invite request + GP1-->>GP2: GCC-Conference-Invite indication + GP2->>Node: GCC-Conference-Invite indication + Node-->>GP2: GCC-Conference-Invite response + GP2-->>GP1: GCC-Conference-Invite response + GP1->>MCU: GCC-Conference-Invite confirm + +``` + +The diagram illustrates the sequence of primitives for the GCC-Conference-Invite process. It involves four entities: Inviting MCU Node Controller, two GCC Providers, and an Invited Node Node Controller. The process begins with the Inviting MCU Node Controller sending a 'GCC-Conference-Invite request' to the first GCC Provider. This request is then passed as a 'GCC-Conference-Invite indication' to the second GCC Provider, which in turn sends the indication to the Invited Node Node Controller. The Invited Node Node Controller responds with a 'GCC-Conference-Invite response' back to the second GCC Provider, which then passes it back to the first GCC Provider. Finally, the first GCC Provider sends a 'GCC-Conference-Invite confirm' message back to the Inviting MCU Node Controller. + +Sequence diagram showing the GCC-Conference-Invite process between an Inviting MCU Node Controller, two GCC Providers, and an Invited Node Node Controller. + +**Figure 7-4 – GCC-Conference-Invite – Sequence of primitives** + +#### 7.1.2.5 GCC-Conference-Add + +The GCC-Conference-Add request primitive may be used by a Node Controller to add a single additional node to an existing conference by requesting that an MCU dial out the specified node. This primitive is only valid if issued by the Convener or a convener-designated node. If the Adding MCU is specified, the sequence of primitives is direct between the requester and the adding MCU. If the Adding MCU is not specified, the indication is issued from the Top GCC Provider. In this case, if a port capable of performing the add is available at this node, the exchange is also direct. If the Node Controller at the Top GCC Provider maintains or has access to a central database of port information for all MCUs in the conference, it may perform the add indirectly by issuing another GCC-Conference-Add request, specifying an Adding MCU (even if the top MCU is not a convener-designated privileged node for this operation). + +Once provision has been made to set up the physical connection to the Added Node (if needed), the GCC-Conference-Invite request primitive shall be issued by the Adding MCU to invite the Added Node into the conference. If the Adding MCU already has a physical connection to the Added Node, the Adding MCU may issue the GCC-Conference-Invite request directly to the Added Node without establishing a new physical connection. If this connection had been established without knowledge of the Network Address of the Added Node (e.g., the Added Node had dialled into the Adding MCU to connect to a separate conference), the Network Address parameters in the Conference Roster may be used to provide the information needed to match the Network Address of an already connected node with that of a node to be added. Table 7-6 shows the parameters and types of this primitive. Figures 7-5 and 7-6 show the sequence of events when using this primitive in the direct and indirect cases, respectively. + +**Table 7-6 – GCC-Conference-Add – Types of primitives and their parameters** + +| Parameter | Request | Indication | Response | Confirm | +|--------------------|---------|------------|----------|---------| +| Conference ID | M | M | M(=IN) | M(=RQ) | +| Network Address | M | M(=) | M(=) | M(=) | +| Adding MCU Node ID | O | | | | +| Requesting Node ID | | M | M(=) | | +| Node Category | O | O(=) | | | +| User Data | O | O(=) | O | O(=) | +| Result | | | M | M(=) | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Network Address*: This parameter consists of a list of one or more connection descriptions, each representing a portion of the total logical connection toward the added node. A particular connection description provides information on the network connection to be established toward the added node (type of network, type of circuit, network address), and optionally the possible ways to aggregate digital circuits when relevant, the multimedia profiles that the adding MCU may operate over the connection, and the media (i.e., audio, video, data) concerned with the connection. Parameters composing each element of the network address are presented in 7.1.2.5.1. In the GCC protocol, this parameter is reflected by ASN.1 structures NetworkAddress and NetworkAddressV2. See Annex B for the description and use of these. + +The NSAP part of a transport address may encapsulate within itself certain patterns that by convention suggest the choice of a switched connection or a connectionless network protocol. In such cases, the listed element stands alone as an independent alternative to any aggregated channel or non-standard addresses that may also be present. On the other hand, a transport address may instead be incomplete and may depend implicitly on the shared use of a data channel opened within a multimedia multiplex of aggregated channels, as specified in [ITU-T T.123] or in some non-standard way. In these cases, a locally-specified NSAP address and/or transport selector may be needed to steer new connections in the data channel to the correct termination point. NSAP addresses are conveyed, according to [ITU-T T.123], as Calling or Called Party Subaddress information elements in SETUP, and transport selectors as TSAP identifiers in an X.224 connection request. + +*Adding MCU Node ID*: This is an optional parameter which may be used to specify the particular MCU node from which the called node is to be added. If this parameter is not specified, the called node may be added from any available MCU in the conference. In this case, the indication occurs from the Top GCC Provider. The node controller at that MCU may either service it locally, or issue another request to a specific MCU. + +*Requesting Node ID*: Node ID of the requesting node. + +*Node Category*: This informs the node that is being invited of the node category into which it falls. The invited node has no say in this selection. The invite should fail when an older protocol node that does not understand Node Categories is invited. When this occurs, the result should state that the node category parameter was unacceptable. + +*User Data*: Optional user data which may be used for functions outside the scope of this Recommendation such as authentication, billing, etc. + +*Result*: An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, invalid adding MCU, not convener or convener-designated node, invalid network type, invalid network address, added node busy, network busy, connection unsuccessful, no ports available. + +![Sequence diagram for GCC-Conference-Add (direct case) showing interactions between Requesting Node Node Controller, GCC Provider, Top GCC Provider, GCC Provider, Adding MCU Node Controller, GCC Provider, GCC Provider, and Added Node Node Controller. The sequence includes GCC-Conference-Add request, GCC-Conference-Add indication, GCC-Conference-Add response, GCC-Conference-Add confirm, GCC-Conference-Invite request, GCC-Conference-Invite indication, and GCC-Conference-Invite response.](9a5927586a691c4908aa2cf98bd47ebb_img.jpg) + +T.124(01-07)\_F7-05 + +Sequence diagram for GCC-Conference-Add (direct case) showing interactions between Requesting Node Node Controller, GCC Provider, Top GCC Provider, GCC Provider, Adding MCU Node Controller, GCC Provider, GCC Provider, and Added Node Node Controller. The sequence includes GCC-Conference-Add request, GCC-Conference-Add indication, GCC-Conference-Add response, GCC-Conference-Add confirm, GCC-Conference-Invite request, GCC-Conference-Invite indication, and GCC-Conference-Invite response. + +**Figure 7-5 – GCC-Conference-Add (direct case) – Sequence of primitives** + +![Sequence diagram for GCC-Conference-Add (indirect case) showing interactions between Requesting Node Node Controller, GCC Provider, Top GCC Provider, Top MCU Node Controller, Top GCC Provider, GCC Provider, Adding MCU Node Controller, GCC Provider, GCC Provider, and Added Node Node Controller. The sequence includes GCC-Conference-Add request, GCC-Conference-Add indication, GCC-Conference-Add request, GCC-Conference-Add response, GCC-Conference-Add confirm, GCC-Conference-Add response, GCC-Conference-Add indication, GCC-Conference-Invite request, GCC-Conference-Invite indication, GCC-Conference-Invite response, and GCC-Conference-Invite confirm.](95e259e8cb3519025066052af263f8c0_img.jpg) + +T.124(01-07)\_F7-06 + +Sequence diagram for GCC-Conference-Add (indirect case) showing interactions between Requesting Node Node Controller, GCC Provider, Top GCC Provider, Top MCU Node Controller, Top GCC Provider, GCC Provider, Adding MCU Node Controller, GCC Provider, GCC Provider, and Added Node Node Controller. The sequence includes GCC-Conference-Add request, GCC-Conference-Add indication, GCC-Conference-Add request, GCC-Conference-Add response, GCC-Conference-Add confirm, GCC-Conference-Add response, GCC-Conference-Add indication, GCC-Conference-Invite request, GCC-Conference-Invite indication, GCC-Conference-Invite response, and GCC-Conference-Invite confirm. + +**Figure 7-6 – GCC-Conference-Add (indirect case) – Sequence of primitives** + +##### 7.1.2.5.1 Network Address Element + +The structure of a Network Address element is presented by Table 7-7. + +**Table 7-7 – Structure of a Network Address element** + +| Parameter | Description | +|--------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Network Connection | This parameter consists in either of a single connection description or the description of a connection formed by aggregation of ISDN or CSDN digital circuits. This parameter is described in details through points 1) and 2) hereafter. | +| Profiles | This parameter is a list of one or more profiles that may be operated over the connection. Each profile may describe a basic transfer mode such as simple telephony or a more complex suites of protocols such as H.320/T.120. Possible values are "Speech", "3 kHz telephony", "7 kHz telephony", "Voice-band", "Frame Relay", "T.123 basic profile for PSTN/GSTN", "T.123 basic profile for PSDN", "T.123 basic profile for B-ISDN", "H.310", "H.320", "H.321", "H.322", "H.323", "H.324", "H.324m", "ASVD", "DSVD", "DSM-CC Download Profile" and "Non Standard". For multimedia profiles (H.32x, ASVD and DSVD), a Boolean flag is associated to indicate whether the T.120 suites of protocols shall be operated for the data portion of the multiplex. The exact structures of non-standard profiles are user-defined. | +| Media Concerned | This is a list of three Boolean flags that gives the list of media (i.e., audio, video and data) that are concerned by the connection. | + +###### 1) *Single connections* + +When *Network Connection* consists in a single connection, it may take different forms, depending on whether or not the connection is accurately described, and, when it is the case, on the type of network to which the added node is connected. Networks considered by this version of T.124 are GSTN, ISDN, CSDN, PSDN and ATM networks. + +###### 1a) GSTN connections: + +For GSTN networks, *Network Connection* simply consists in an *Extended E.164 Network Address*, where optional parameter *Sub-Address* is not applicable. The structure of an extended E.164 network address is presented by Table 7-8-1 below: + +**Table 7-8-1 (see Note) – Structure of an extended E.164 network address** + +| Parameter | Description | +|-------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| International Number | This is a string of digits, up to 16 digits in length, which represents the full international number of the node to be added. | +| Sub-Address
(optional) | This is an optional parameter, valid only in the case of ISDN transfer modes, which represents the ISDN sub-address of the node to be added. This is a string of digits, up to 40 digits in length. | +| Extra Dialling String
(optional) | This is an optional parameter which indicates that additional information is needed to reach the node to be added once the physical connection has been established. In the case of a speech or voice-band data connection, for example, this may represent DTMF tones to be transmitted over the voice channel once it has been established. Alternatively, the extra dialling may represent a virtual private network number. This is a string up to 255 characters which may be either the digits 1 through 9, the "#" character, the "*" character, or the "," (comma) character. The comma character is meant to represent a one-second delay the Adding MCU is to insert prior to the characters which follow. | + +NOTE – Tables 7-7-2 to 7-7-6 of T.124 (1998) were renumbered in the 2007 edition to Tables 7-8-1 to 7-8-5, respectively. + +###### 1b) ISDN connections: + +For ISDN networks, *Network Connection* consists in a structure of two elements, the first being a list of circuit types that the added node and its access network are capable of operating, the second being an extended E.164 network address that shall be dialled to reach the added node. Table 7-8-2 shows the structure of a single ISDN connection descriptor: + +**Table 7-8-2 (see Note) – Structure of a single connection – ISDN networks case** + +| Parameter | Description | +|--------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Circuit Types | This is a list of one or more types of circuits that may be switched to reach the added node. Possible types correspond to the codepoints of octet 4 of IE Bearer Capability of ITU-T Rec. Q.931. These are " digital 64k channel " (B-Channel), " 2 x digital 64k channel ", " digital 384k channel " (H0 channel), " digital 1536k channel " (H11 channel), " digital 1920k channel " (H12 channel) and " multirate based 64k channels ". For the latest option, an integer value is indicated, the multiplier , that gives the effective rate. When more than one types is passed, the choice is left to the discretion of the adding MCU. | +| Extended E.164 Network Address | This parameter has the format described by Table 7-8-1. | + +**Table 7-8-2 (see Note) – Structure of a single connection – ISDN networks case** + +| Parameter | Description | +|-------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| High Layer Compatibility Information (optional) | This is an optional parameter which indicates the mode of operation this portion of the connection is to use. This information is required for connections made in some countries. The modes of operation are one or more of telephony at 3 kHz bandwidth, telephony at 7 kHz bandwidth, videotelephony, videoconferencing, audiographics, audiovisual, or multimedia. If more than one of these is selected, this indicates that the Adding MCU may use one of the indicated modes at its discretion. The definitions of these choices may depend on the country of operation of the Adding MCU. The codepoints defined for this parameter match those defined for Information Element Higher Layer Compatibility of the ISDN signalling protocol (ITU-T Rec. Q.931). | + +###### 1c) CSDN connections: + +For CSDN networks, *Network Connection* consists in a structure of two elements, the first being a list of circuit types that the added node and its access network are capable of operating, the second being an extended E.164 network address that shall be dialled to reach the added node. Table 7-8-3 shows the structure of a single CSDN connection descriptor: + +**Table 7-8-3 (see Note) – Structure of a single connection – CSDN networks case** + +| Parameter | Description | +|--------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Circuit Types | This is a list of one or two types of circuits that may be switched to reach the added node. Possible types are " digital 56k channel " and " digital 64k channel ". When both types are passed, the choice is left to the discretion of the adding MCU. | +| Extended E.164 Network Address | This parameter has the format described by Table 7-8-1. | + +###### 1d) ATM connections: + +For ATM networks, *Network Connection* consists in a structure of two elements, the first being either of an extended E.164 network address, a NSAP address, or a non-standard address format assumed to be understood by the adding MCU, and the second being an optional integer value giving the maximum possible transfer rate toward the added node, expressed in ATM cells per seconds. + +NOTE – Certain private ATM networks use the E.164 standard address format coupled with an NSAP to reach endpoints. In that case, optional parameter Extra Dialling String may be used to convey the NSAP. + +###### 1e) PSDN connections: + +For PSDN networks, *Network Connection* simply consists in either of the extended E.164 network address described by Table 7-8-1, a *Transport Address Descriptor*, or a non standard address format assumed to be understood by the adding MCU. Table 7-8-4 gives the structure of a transport address descriptor: + +**Table 7-8-4 (see Note) – Structure of transport address descriptor** + +| Parameter | Description | +|-------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| NSAP Address | This is an Octet String of up to 20 octets in length which is the preferred binary encoding (per A.8.3.1/X.213) of the Network Service Access Point address of the node to be added. | +| Transport Selector (optional) | This is an optional parameter which may be used to select the Transport Service Access Point at the node to be added. | + +1f) Undescribed connections: + +In this case, *Network Connection* consists in either of the extended E.164 network address described by Table 7-8-1, a *Transport Address Descriptor*, or a non-standard address format assumed to be understood by the adding MCU. + +2) *ISDN or CSDN digital circuits aggregation* + +When parameter *Network Connection* of Table 7-7 is used for aggregated CSDN or ISDN channels, it has a structure of two elements, the first being a list of digital circuits that shall be aggregated together, the second being an optional list of channel aggregation algorithms usable for aggregating the circuits. Table 7-8-5 details this structure: + +**Table 7-8-5 (see Note) – Structure of an aggregated channels connection** + +| Parameter | Description | +|--------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Aggregated Connections | This is a list of one ore more elements, each having either of the structures described in Tables 7-8-2 and 7-8-3. When one or more elements of the list gives multiple circuit types, the choice is left to the adding MCU for the final combination. | +| Aggregation Methods (optional) | This is a list of one or more standard or non-standard channel aggregation algorithms that may be used to aggregate digital circuits together. Possible standard algorithms are "H.221", "H.244" and "ISO/IEC 13871". Non-standard algorithms are supposed to be understood by the adding MCU. This parameter is optional. If not supplied, the choice is left to the adding MCU.

NOTE – The actual algorithm is implicit for certain profiles that may be listed by parameter Profiles of Table 7-7 (ex. ITU-T Rec. H.320). | + +#### 7.1.2.6 GCC-Conference-Lock + +The GCC-Conference-Lock request primitive may be used by a Node Controller to lock a conference, preventing other nodes from dialling into the conference at all. This primitive is valid only if issued by the Convener or a convener-designated node. While locked, participants may be added to a conference only by using the GCC-Conference-Invite primitive (or indirectly inviting via the GCC-Conference-Add primitive). The order of GCC-Conference-Lock and GCC-Conference-Unlock primitives exchanged between a node and the Top GCC Provider is preserved. Table 7-9 shows the parameters and types of this primitive. Figure 7-7 shows the sequence of events when using this primitive. + +**Table 7-9 – GCC-Conference-Lock – Types of primitives and their parameters** + +| Parameter | Request | Indication | Response | Confirm | +|----------------|---------|------------|----------|---------| +| Conference ID | M | M | M(=IN) | M(=RQ) | +| Source Node ID | | M | M(=) | | +| Result | | | M | M(=) | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Source Node ID*: Node ID of the requesting node. + +*Result*: An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, function not available, already locked, not convener or convener-designated node. + +![Sequence diagram for GCC-Conference-Lock showing interactions between Node Controller, GCC Provider, Top GCC Provider, and All Nodes Node Controller.](8e80de0cac529b2c3775d677c5203133_img.jpg) + +``` + +sequenceDiagram + participant NC1 as Node Controller + participant GP1 as GCC Provider + participant TGP as Top GCC Provider + participant GP2 as GCC Provider + participant NC2 as Node Controller + participant ANNC as All Nodes Node Controller + + NC1->>GP1: GCC-Conference-Lock request + GP1-->>TGP: + TGP->>NC2: GCC-Conference-Lock indication + NC2->>TGP: GCC-Conference-Lock response + TGP-->>GP1: + GP1->>NC1: GCC-Conference-Lock confirm + TGP-->>GP2: + GP2->>ANNC: GCC-Conference-Lock-Report indication + +``` + +T.124(01-07)\_F7-07 + +Sequence diagram for GCC-Conference-Lock showing interactions between Node Controller, GCC Provider, Top GCC Provider, and All Nodes Node Controller. + +**Figure 7-7 – GCC-Conference-Lock – Sequence of primitives** + +#### 7.1.2.7 GCC-Conference-Unlock + +The GCC-Conference-Unlock request primitive may be used by a Node Controller to unlock a previously locked conference. Unlocking a conference allows other nodes to join the conference by dialling into it in a meet-me style. If the conference was created specifying the use of Password protection, the Password is still required for any participant attempting to join the unlocked conference. This primitive is valid only if issued by the Convener or a convener-designated node. The order of GCC-Conference-Lock and GCC-Conference-Unlock primitives exchanged between a node and the Top GCC Provider is preserved. Table 7-10 shows the parameters and types of this primitive. Figure 7-8 shows the sequence of events when using this primitive. + +**Table 7-10 – GCC-Conference-Unlock – Types of primitives and their parameters** + +| Parameter | Request | Indication | Response | Confirm | +|----------------|---------|------------|----------|---------| +| Conference ID | M | M | M(=IN) | M(=RQ) | +| Source Node ID | | M | M(=) | | +| Result | | | M | M(=) | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Source Node ID*: Node ID of the requesting node. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, function not available, already unlocked, not convener or convener-designated node. + +![Sequence diagram for GCC-Conference-Unlock showing interactions between Node Controller, GCC Provider, Top GCC Provider, and All Nodes Node Controller.](6cc85a2b62fd8a2a3faab29730f20e81_img.jpg) + +``` + +sequenceDiagram + participant NC1 as Node Controller + participant GP1 as GCC Provider + participant TGP as Top GCC Provider + participant NC2 as Node Controller + participant GP2 as GCC Provider + participant ANNC as All Nodes Node Controller + + NC1->>GP1: GCC-Conference-Unlock request + GP1-->>TGP: + TGP->>NC2: GCC-Conference-Unlock indication + NC2-->>GP2: GCC-Conference-Unlock response + GP2-->>TGP: + TGP-->>GP1: GCC-Conference-Unlock confirm + GP2->>ANNC: GCC-Conference-Lock-Report indication + +``` + +T.124(01-07)\_F7-08 + +Sequence diagram for GCC-Conference-Unlock showing interactions between Node Controller, GCC Provider, Top GCC Provider, and All Nodes Node Controller. + +**Figure 7-8 – GCC-Conference-Unlock – Sequence of primitives** + +#### 7.1.2.8 GCC-Conference-Lock-Report + +The GCC-Conference-Lock-Report indication primitive is issued to the Node Controller at all nodes in a conference as a result of a successful GCC-Conference-Lock request or a successful GCC-Conference-Unlock request. Figures 7-7 and 7-8 show the sequence of events leading to the use of this primitive. See also Table 7-11. + +**Table 7-11 – GCC-Conference-Lock-Report – +Types of primitives and their parameters** + +| Parameter | Indication | +|-----------------|------------| +| Conference ID | M | +| Locked/Unlocked | M | + +*Conference ID:* Identifier of the MCS Domain corresponding to the locked conference. + +*Locked/Unlocked:* Flag indicating if the conference has switched into locked or unlocked mode. + +#### 7.1.2.9 GCC-Conference-Disconnect + +The GCC-Conference-Disconnect request primitive is used by a Node Controller to disconnect itself from a conference. Disconnecting from a conference does not imply disconnecting the corresponding physical connection. Once disconnected from the conference, a terminal may then join another conference. If GCC detects that a node has abnormally disconnected from a conference (e.g., the physical call has been disconnected), it shall send a GCC-Conference-Disconnect indication to all remaining nodes in the conference. Table 7-12 shows the parameters and types of this primitive. + +Figures 7-9 and 7-13 show the sequence of events when using this primitive for client-initiated disconnects. Figure 7-11 shows the case of a GCC-initiated abnormal disconnect. + +**Table 7-12 – GCC-Conference-Disconnect – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|-----------------------|---------|------------|---------| +| Conference ID | M | M | M(=RQ) | +| Reason for disconnect | | M | | +| Disconnecting Node ID | | M | | +| Result | | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Reason for disconnect*: Indication of the reason for disconnecting from the conference. Either user-initiated, ejected node, or unknown. + +*Disconnecting Node ID*: Node ID corresponding to the disconnected node. + +*Result*: An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference. + +NOTE – If it is necessary to allow a Node Controller to disconnect from a conference prior to completion of the connection establishment (e.g., prior to reception of a GCC-Conference-Join confirm), it would be necessary to provide a local means of association of the conference to be disconnected with the conference being established. This is because the Conference ID is not known by the Node Controller until after creating or joining a conference. The mechanism for doing so is a local matter and is beyond the scope of this Recommendation. + +![Sequence diagram for GCC-Conference-Disconnect (client-initiated). The diagram shows four lifelines: Node Controller, GCC Provider, GCC Provider, and All Nodes Node Controller. The sequence of events is: 1. Node Controller sends 'GCC-Conference-Disconnect request' to the first GCC Provider. 2. A dashed arrow indicates a message passing from the first GCC Provider to the second GCC Provider. 3. The second GCC Provider sends 'GCC-Conference-Disconnect indication' to All Nodes Node Controller. 4. All Nodes Node Controller sends 'GCC-Conference-Disconnect confirm' back to the Node Controller.](a3083eec2a883ee8327b3c24174df6a9_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant GP1 as GCC Provider + participant GP2 as GCC Provider + participant ANNC as All Nodes Node Controller + + NC->>GP1: GCC-Conference-Disconnect request + GP1-->>GP2: + GP2->>ANNC: GCC-Conference-Disconnect indication + ANNC-->>NC: GCC-Conference-Disconnect confirm + +``` + +T.124(01-07)\_F7-09 + +Sequence diagram for GCC-Conference-Disconnect (client-initiated). The diagram shows four lifelines: Node Controller, GCC Provider, GCC Provider, and All Nodes Node Controller. The sequence of events is: 1. Node Controller sends 'GCC-Conference-Disconnect request' to the first GCC Provider. 2. A dashed arrow indicates a message passing from the first GCC Provider to the second GCC Provider. 3. The second GCC Provider sends 'GCC-Conference-Disconnect indication' to All Nodes Node Controller. 4. All Nodes Node Controller sends 'GCC-Conference-Disconnect confirm' back to the Node Controller. + +**Figure 7-9 – GCC-Conference-Disconnect (client-initiated) – Sequence of primitives** + +#### 7.1.2.10 GCC-Conference-Terminate + +The GCC-Conference-Terminate request primitive is used by a Node Controller to terminate an entire conference. This primitive shall only be issued by the conference Convener or a convener-designated node. Terminating a conference does not imply termination of the corresponding physical connection. Table 7-13 shows the parameters and types of this primitive. Figures 7-10, 7-11 and 7-12 show the sequence of events when using this primitive for client-initiated and GCC-initiated cases. The GCC-initiated case can result either from abnormal termination at the lower layers of the protocol, or at the Top GCC Provider, if the conference had been created as an automatically terminating conference and all other nodes have disconnected from the conference. + +NOTE – In most cases, reception of the GCC-Conference-Terminate indication implies that the entire conference has been terminated – i.e., all members have been disconnected. In the case that error termination is given as the reason code, this primitive implies that the local node has been unexpectedly removed from the conference, but does not necessarily imply that the entire conference has been terminated. + +**Table 7-13 – GCC-Conference-Terminate – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|------------------------|---------|------------|---------| +| Conference ID | M | M | M(=RQ) | +| Reason for termination | O | O(=) | | +| Result | | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Reason for termination*: Indication of the reason for termination of the conference. This contains one of a list of possible reasons: requested normal termination, requested timed conference termination, no more participants in automatically terminating conference, error termination. + +*Result*: An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, not convener or convener-designated node. + +![Sequence diagram showing the GCC-Conference-Terminate (client-initiated) sequence of primitives between Node Controller, GCC Provider, Top GCC Provider, and All Nodes Node Controller.](0f26e70157bd4c45f825795cdcd20fbd_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant GP as GCC Provider + participant TGP as Top GCC Provider + participant GPC as GCC Provider + participant ANNC as All Nodes Node Controller + + NC->>GP: GCC-Conference-Terminate request + GP-->>TGP: + TGP-->>GPC: + GPC->>ANNC: GCC-Conference-Terminate indication + ANNC-->>GPC: + GPC-->>TGP: + TGP-->>GP: + GP-->>NC: GCC-Conference-Terminate confirm + GPC-->>NC: GCC-Conference-Terminate indication + +``` + +The diagram illustrates the sequence of primitives for GCC-Conference-Terminate (client-initiated). It involves five entities: Node Controller, GCC Provider, Top GCC Provider, GCC Provider, and All Nodes Node Controller. The sequence is as follows: 1. Node Controller sends a 'GCC-Conference-Terminate request' to the first GCC Provider. 2. The first GCC Provider sends a message to the Top GCC Provider. 3. The Top GCC Provider sends a message to the second GCC Provider. 4. The second GCC Provider sends a 'GCC-Conference-Terminate indication' to the All Nodes Node Controller. 5. The All Nodes Node Controller sends a message back to the second GCC Provider. 6. The second GCC Provider sends a message back to the Top GCC Provider. 7. The Top GCC Provider sends a message back to the first GCC Provider. 8. The first GCC Provider sends a 'GCC-Conference-Terminate confirm' to the Node Controller. 9. The second GCC Provider sends a 'GCC-Conference-Terminate indication' to the Node Controller. + +Sequence diagram showing the GCC-Conference-Terminate (client-initiated) sequence of primitives between Node Controller, GCC Provider, Top GCC Provider, and All Nodes Node Controller. + +**Figure 7-10 – GCC-Conference-Terminate (client-initiated) – Sequence of primitives** + +![Sequence diagram for GCC-Conference-Terminate (error termination). It shows two GCC Providers and two Node Controllers. The first GCC Provider sends a GCC-Conference-Terminate indication to the Removed Node Node Controller. The second GCC Provider sends a GCC-Conference-Disconnect indication to the All Remaining Nodes Node Controller. A dashed line connects the two Node Controllers.](12c19090355e19922e23044633b9d1ea_img.jpg) + +T.124(01-07)\_F7-11 + +Sequence diagram for GCC-Conference-Terminate (error termination). It shows two GCC Providers and two Node Controllers. The first GCC Provider sends a GCC-Conference-Terminate indication to the Removed Node Node Controller. The second GCC Provider sends a GCC-Conference-Disconnect indication to the All Remaining Nodes Node Controller. A dashed line connects the two Node Controllers. + +**Figure 7-11 – GCC-Conference-Terminate (error termination) – Sequence of primitives** + +![Sequence diagram for GCC-Conference-Terminate (automatic termination). It shows a GCC Provider sending a GCC-Conference-Terminate indication to a Remaining Node Node Controller.](01e00200a536673d6cd0e6d8705047a0_img.jpg) + +T.124(01-07)\_F7-12 + +Sequence diagram for GCC-Conference-Terminate (automatic termination). It shows a GCC Provider sending a GCC-Conference-Terminate indication to a Remaining Node Node Controller. + +**Figure 7-12 – GCC-Conference-Terminate (automatic termination) – Sequence of primitives** + +#### 7.1.2.11 GCC-Conference-Eject-User + +The GCC-Conference-Eject-User request primitive is used by a Node Controller to force a particular node to be disconnected from a conference. This primitive shall only be issued by the conference Convener or a convener-designated node or by a node directly above the ejected node in the connection hierarchy. Being ejected from a conference does not imply termination of the corresponding physical connection. When a node is ejected, a GCC-Conference-Disconnect indication is issued to the Node Controller at all nodes remaining in the conference indicating that the ejected node has disconnected due to being ejected. Table 7-14 shows the parameters and types of this primitive. Figure 7-13 shows the sequence of events when using this primitive. + +**Table 7-14 – GCC-Conference-Eject-User – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|---------------------|---------|------------|---------| +| Conference ID | M | M | M(=RQ) | +| Ejected Node ID | M | M(=) | M(=) | +| Reason for ejection | O | O(=) | | +| Result | | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Ejected Node ID*: The node to be ejected. + +*Reason for ejection*: Indication of the reason for ejection: user-initiated, higher node disconnected, or higher node ejected. + +*Result*: An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, invalid user to eject, not convener or convener-designated node. + +![Sequence diagram for GCC-Conference-Eject-User (client-initiated). The diagram shows the flow of primitives between a Node Controller, GCC Providers, an Ejected Node Controller, and All Remaining Nodes. The sequence is: 1. Node Controller sends GCC-Conference-Eject-User request to GCC Provider. 2. GCC Provider sends GCC-Conference-Eject-User indication to Ejected Node Controller. 3. Ejected Node Controller sends GCC-Conference-Disconnect indication to All Remaining Nodes. 4. GCC Provider sends GCC-Conference-Eject-User confirm back to Node Controller.](7e61b2e2506cc7e5d6e16ce9c9df25bb_img.jpg) + +Node Controller      GCC Provider      Top GCC Provider      GCC Provider      Ejected Node Node Controller      GCC Provider      All Remaining Nodes Node Controller + +Sequence of primitives: + +- Node Controller → GCC Provider: GCC-Conference-Eject-User request +- GCC Provider → Ejected Node Node Controller: GCC-Conference-Eject-User indication +- Ejected Node Node Controller → All Remaining Nodes Node Controller: GCC-Conference-Disconnect indication +- GCC Provider → Node Controller: GCC-Conference-Eject-User confirm + +T.124(01-07)\_F7-13 + +Sequence diagram for GCC-Conference-Eject-User (client-initiated). The diagram shows the flow of primitives between a Node Controller, GCC Providers, an Ejected Node Controller, and All Remaining Nodes. The sequence is: 1. Node Controller sends GCC-Conference-Eject-User request to GCC Provider. 2. GCC Provider sends GCC-Conference-Eject-User indication to Ejected Node Controller. 3. Ejected Node Controller sends GCC-Conference-Disconnect indication to All Remaining Nodes. 4. GCC Provider sends GCC-Conference-Eject-User confirm back to Node Controller. + +**Figure 7-13 – GCC-Conference-Eject-User (client-initiated) – Sequence of primitives** + +#### 7.1.2.12 GCC-Conference-Transfer + +The GCC-Conference-Transfer request primitive is used by a Node Controller to cause selected nodes in a conference to disconnect from that conference and join another conference. This primitive shall only be issued by the conference Convener or a convener-designated node. Some MCUs in a conference may be already joined to both the originating and destination conferences prior to the transfer taking place. If so, these MCUs shall not be included in the list of Transferring Nodes in this request. If an MCU is not joined with both conferences but will be connected to nodes which, after the transfer, will be joined to both conferences (if not all nodes are transferred), then that MCU shall be joined to the destination conference prior to issuing the GCC-Conference-Transfer request. Any MCU which is included in the list of Transferring Nodes (those which are intended to transfer) shall complete the transfer operation (disconnecting from the originating conference and joining the destination conference) prior to processing any new GCC-Conference-Join indications. This allows the join request from the nodes below that MCU in the connection hierarchy to be successfully completed. Nodes which are in the process of transferring and receiving a GCC-Conference-Terminate indication for the originating conference may proceed directly to joining the destination conference without disconnecting if they have not already done so. This situation could arise if the MCU to which the node is connected was also instructed to transfer. Table 7-15 shows the parameters and types of this primitive. Figure 7-14 shows the sequence of events when using this primitive. + +**Table 7-15 – GCC-Conference-Transfer – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|-----------------------------------------------|---------|------------|---------| +| Conference ID | M | M | M(=RQ) | +| Destination Conference Name | M | M(=) | M(=) | +| Destination Conference Name Modifier | O | O(=) | O(=) | +| Destination Network Address | O | O(=) | | +| Transferring Nodes (List of Node IDs or null) | O | | O(=) | +| Password | C | C(=) | | +| Result | | | M | + +*Conference ID:* Identifier of the MCS Domain corresponding to the conference to which the designated nodes are joined prior to the transfer operation. + +*Destination Conference Name:* Name of the conference to which the designated nodes are instructed to join. This is the name by which the conference is known at the MCU or MCUs to which the transferring nodes are connected. If the conference had been created using both the numerical and text forms of the Conference Name, either form may be used in this primitive. + +*Destination Conference Name Modifier:* If an MCU in the destination conference had chosen to use the optional Conference Name Modifier (as a result of local naming uniqueness problem), nodes to be transferred which are connected to this MCU must be transferred separately, with a separate exchange of the GCC-Conference-Transfer primitive from those nodes which are connected to MCUs using the unmodified (or differently modified) base Conference Name. The manner by which the requesting node becomes aware of Conference Name Modifiers at various MCUs is considered a matter outside the scope of this Recommendation. + +*Destination Network Address:* This parameter optionally describes a nominal logical connection that each transferred node shall use to join the destination conference, if it is not directly connected to an MCU already joined (or hosting) the destination conference. Each portion of the logical connection is described in terms of network type, network address, transfer rate when relevant, and optionally a multimedia profile that shall be operated, a digital circuits aggregation algorithm when applicable, and the list of media (e.g., audio, video, data) that are concerned by this portion. The relevant parts (i.e., network address elements) are to be passed as parameter Called Address in the GCC-Conference-Join-request to be issued by a transferring node. In the GCC protocol, this parameter is reflected by ASN.1 structures NetworkAddress and NetworkAddressV2. See Annex B for the description and use of these. + +NOTE – The model assumes that a nominal logical connection is available for all transferring nodes, which may not be valid assumption in all cases. For instance, in the case of an ISDN 2 B-Channels/H.320 based conference, this assumes that the same E.164 number (or pair of E.164 numbers) may be used by all nodes transferring to the destination conference. In the case where the ISDN network does not supply the Calling Party Number at the called side, the connected MCU has no mean to associate individual B-Channels into pairs. Providing a destination network address on a per transferring node basis is left for further study. + +*Transferring nodes (List of Node IDs or null):* List of Node IDs identifying GCC Providers to which the indication should go, or omitted, to indicate it should go to all nodes in the conference designated by the Conference ID. + +*Password:* This parameter indicates the password that the transferring nodes shall use in the GCC-Conference-Join request to join the new conference. This is a numeric string or a Unicode Row 00 text string (maximum 255 digits or characters). The Node Controller shall determine whether to send the Password as a text string or numeric string based on its value. A value consisting only of numeric digits shall be specified as a numeric string, while a value including at least one + +non-numeric character shall be specified as a text string. This parameter shall only be used if the Password In The Clear Required flag is set for this conference. + +![Sequence diagram for GCC-Conference-Transfer showing interactions between various nodes and providers.](3c6151f296d5800335472b7dc00ce423_img.jpg) + +The diagram illustrates the sequence of primitives for a GCC-Conference-Transfer. It involves the following participants: Requesting Node Node Controller, GCC Provider, Top GCC Provider, GCC Provider, Transferring Node Node Controller, GCC Provider, GCC Provider, and All Nodes – Original Conference Node Controller. The sequence of events is as follows: 1. Requesting Node Node Controller sends GCC-Conference-Transfer request to GCC Provider. 2. GCC Provider sends GCC-Conference-Transfer indication to Top GCC Provider. 3. Top GCC Provider sends GCC-Conference-Transfer indication to Transferring Node Node Controller. 4. Transferring Node Node Controller sends GCC-Conference-Disconnect request to GCC Provider. 5. GCC Provider sends GCC-Conference-Disconnect indication to All Nodes – Original Conference Node Controller. 6. All Nodes – Original Conference Node Controller sends GCC-Conference-Disconnect confirm to Transferring Node Node Controller. 7. Transferring Node Node Controller sends GCC-Conference-Join request to GCC Provider. 8. GCC Provider sends GCC-Conference-Join indication to Top GCC Provider. 9. Top GCC Provider sends GCC-Conference-Join indication to Top MCU – Destination Conference Node Controller. 10. Top MCU – Destination Conference Node Controller sends GCC-Conference-Join response to GCC Provider. 11. GCC Provider sends GCC-Conference-Join confirm to Transferring Node Node Controller. 12. Transferring Node Node Controller sends GCC-Conference-Transfer confirm to Requesting Node Node Controller. + +T.124(01-07)\_F7-14 + +Sequence diagram for GCC-Conference-Transfer showing interactions between various nodes and providers. + +**Figure 7-14 – GCC-Conference-Transfer – Sequence of primitives** + +### 7.1.3 Conference establishment requirements + +In order to avoid the possibility of a deadlock situation in which both sides of a physical connection fail to initiate the GCC conference establishment procedure, waiting for the other to do so, the following requirements are defined for the conference establishment procedure when a physical connection is established (that is, an underlying connection between the two nodes using the PSTN, ISDN, or CSDN cases of T.123). These requirements may be superseded by bilateral agreement between the nodes involved, either via *a priori* arrangement, or via an exchange of information defined outside of the scope of this Recommendation. + +- It must first be known by both ends of the physical connection which end is the calling node and which end is the called node. It must also be known what type of node each of the two nodes are (terminal, multiport terminal, or MCU). This information may be obtained either using the GCC-Conference-Query primitive, or it may be known *a priori*. For determining the calling vs. called node, if neither node is aware of which it is, the symmetry breaking procedure defined for the GCC-Conference-Query primitive is used to arbitrarily choose one node to be the caller for purposes of the conference establishment procedure. +- The calling node shall be responsible for initiating the initial conference establishment procedure (either requesting creation of a new conference, joining a conference at the called node, or inviting the called node into a conference). Note that this, in general, does not preclude the called node from taking actions to establish a conference over the same physical connection as well, although care must be taken in this case to ensure that this action does not interfere with the action of the calling node. A called MCU may set the Wait for Invite Flag in the GCC-Conference-Query response and in doing so relieve the calling node of the responsibility of initiating a connection. + +- When establishing calls among the various node types (terminals, multiport terminals, and MCUs), constraints are placed on the actions of the calling node in initiating the initial connection. Table 7-16 shows these constraints for each permutation of calling and called node type. The definition of the actions shown in the table, numbered 1, 2, 3, and 4 are as follows: + - 1) Calling node requests creation of a new conference at the Called node. + - 2) Calling node attempts to join existing conference at the Called node. + - 3) Calling node creates a conference locally and invites the Called node. + - 4) Calling node invites the Called node into an existing conference. + +**Table 7-16 – Actions of the Calling Node for Conference Establishment** + +| Calling Node | Called Node | | | +|---------------------------|---------------|----------------------|----------------------| +| | Terminal | Multiport Terminal | MCU | +| Terminal | Either 1 or 3 | Either 1 or 2 | Either 1 or 2 | +| Multiport Terminal | Either 3 or 4 | Either 1, 2, 3, or 4 | Either 1 or 2 | +| MCU | Either 3 or 4 | Either 3 or 4 | Either 1, 2, 3, or 4 | + +In some cases, the calling node may need to make use of information from the called node contained in the GCC-Conference-Query confirm to help choose among the allowed procedures defined in Table 7-16. For example, when a Terminal or Multiport Terminal calls a Multiport Terminal, it may make use of the presence or absence of unlocked conferences in the Conference Descriptor List to determine whether it is most appropriate to create a conference automatically (actions 1, 3, or 4), or to allow the user to attempt to join an existing conference at the called node (action 2). Therefore, when creating any conference, making it listed and unlocked indicates that it is to be available to be joined by a calling node. If the intent is not to allow a conference to be joined by a caller, the conference shall be created as locked, unlisted, or both. + +Table 7-17 defines the set of rules for determining the default action of the calling node (as well as the called node) as a function of the node types and the parameter settings contained in the GCC-Conference-Query confirm. + +**Table 7-17 – Rules for determining the default action of the called and calling nodes** + +| Calling Node Type | Called Node Type | Unlocked Conferences in List | Default Conference Flag | Wait for Invite Flag | No Unlisted Conference Flag | Default Action of Calling Node | Default Action of Called Node | +|--------------------------|-------------------------|-------------------------------------|------------------------------------------|-----------------------------|------------------------------------|------------------------------------------|--------------------------------------| +| Terminal | Terminal | * | * | * | * | Caller invites | Wait for caller | +| Multiport Terminal | Terminal | * | * | * | * | Caller invites | Wait for caller | +| MCU | Terminal | * | * | * | * | Caller invites | Wait for caller | +| Terminal | Multiport Terminal | FALSE | * | * | * | Caller creates remotely | Wait for caller | +| Terminal | Multiport Terminal | TRUE | NOT PRESENT or FALSE for all conferences | * | NOT PRESENT or FALSE | Caller chooses conference to join | Wait for caller | +| Terminal | Multiport Terminal | TRUE | NOT PRESENT or FALSE for all conferences | * | TRUE | Caller chooses listed conference to join | Wait for caller | +| Terminal | Multiport Terminal | TRUE | TRUE for one conference | * | * | Caller joins default conference | Wait for caller | +| Multiport Terminal | Multiport Terminal | FALSE | * | * | * | Caller invites | Wait for caller | +| Multiport Terminal | Multiport Terminal | TRUE | NOT PRESENT or FALSE for all conferences | * | NOT PRESENT or FALSE | Caller chooses conference to join | Wait for caller | +| Multiport Terminal | Multiport Terminal | TRUE | NOT PRESENT or FALSE for all conferences | * | TRUE | Caller chooses listed conference to join | Wait for caller | + +**Table 7-17 – Rules for determining the default action of the called and calling nodes** + +| Calling Node Type | Called Node Type | Unlocked Conferences in List | Default Conference Flag | Wait for Invite Flag | No Unlisted Conference Flag | Default Action of Calling Node | Default Action of Called Node | +|--------------------------|-------------------------|-------------------------------------|------------------------------------------|-----------------------------|------------------------------------|-----------------------------------------------------------------------|--------------------------------------| +| Multiport Terminal | Multiport Terminal | TRUE | TRUE for one conference | * | * | Caller joins default conference | Wait for caller | +| MCU | Multiport Terminal | * | * | * | * | Caller invites | Wait for caller | +| Terminal | MCU | FALSE | * | NOT PRESENT or FALSE | NOT PRESENT or FALSE | Caller chooses unlisted conference to join
OR Caller repeats query | Wait for caller | +| Terminal | MCU | FALSE | * | NOT PRESENT or FALSE | TRUE | Caller repeats query | Wait for caller | +| Terminal | MCU | TRUE | NOT PRESENT or FALSE for all conferences | NOT PRESENT or FALSE | NOT PRESENT or FALSE | Caller chooses conference to join | Wait for caller | +| Terminal | MCU | TRUE | NOT PRESENT or FALSE for all conferences | NOT PRESENT or FALSE | TRUE | Caller chooses listed conference to join | Wait for caller | +| Terminal | MCU | TRUE | TRUE for one conference | NOT PRESENT or FALSE | * | Caller joins default conference | Wait for caller | +| Terminal | MCU | * | * | TRUE | * | Caller waits for invite from called node | Called node invites | +| Multiport Terminal | MCU | FALSE | * | NOT PRESENT or FALSE | NOT PRESENT or FALSE | Caller chooses unlisted conference to join
OR Caller repeats query | Wait for caller | + +**Table 7-17 – Rules for determining the default action of the called and calling nodes** + +| Calling Node Type | Called Node Type | Unlocked Conferences in List | Default Conference Flag | Wait for Invite Flag | No Unlisted Conference Flag | Default Action of Calling Node | Default Action of Called Node | +|--------------------------|-------------------------|-------------------------------------|------------------------------------------|-----------------------------|------------------------------------|------------------------------------------|--------------------------------------| +| Multiport Terminal | MCU | FALSE | * | NOT PRESENT or FALSE | TRUE | Caller repeats query | Wait for caller | +| Multiport Terminal | MCU | TRUE | NOT PRESENT or FALSE for all conferences | NOT PRESENT or FALSE | NOT PRESENT or FALSE | Caller chooses conference to join | Wait for caller | +| Multiport Terminal | MCU | TRUE | NOT PRESENT or FALSE for all conferences | NOT PRESENT or FALSE | TRUE | Caller chooses listed conference to join | Wait for caller | +| Multiport Terminal | MCU | TRUE | TRUE for one conference | NOT PRESENT or FALSE | * | Caller joins default conference | Wait for caller | +| Multiport Terminal | MCU | * | * | TRUE | * | Caller waits for invite from called node | Called node invites | +| MCU | MCU | * | * | * | * | FOR FURTHER STUDY | FOR FURTHER STUDY | + +### 7.1.4 Examples of conference establishment procedures + +Conference establishment may be done in a variety of ways and under a variety of conditions. The simplest conference is of the point-to-point variety where there is no MCU involved in the call. In the cases where the conference is established through one or more MCUs, a call would typically be done in either the meet-me style (all participants call into an MCU), in the call-out style (the MCUs set up the call by calling out to all participants), or in the call-through style (one participant calls into an MCU, then adds other participants which are called by the MCU). + +#### 7.1.4.1 Meet-me conference establishment + +In a meet-me conference, a conference is established at an MCU and terminal nodes (as well as other MCUs if necessary) call into the MCU and join the conference. If other MCUs have joined the conference, terminal nodes may call into any of these MCUs to join the conference. + +Initial creation of a meet-me conference may be done out-of-band (e.g., locally initiated at the MCU), or the conference may be created by the first node to call into the MCU. In the former case, GCC is not involved. In the latter, the conference is created at the MCU by issuing a GCC-Conference-Create request over the connection from the convening node to the MCU. In either case, the node at which the conference was created becomes the Top-GCC-Provider. The convening node (the MCU itself in the former case, and the requesting node in the latter) is granted special status as the Conference Convener. + +When a conference is created remotely (using a GCC-Conference-Create request), a Conference Name is specified in the request primitive. If that name is already in use at the MCU, a Conference Name Modifier is assigned by the Node Controller at the MCU to make the name locally unique at that MCU. When other nodes attempt to join the conference at that MCU, this name modifier must be specified as part of the join request. + +When a conference is created remotely it may also include an optional Convener Password. This password is needed only if the Convener intends to disconnect from the conference and rejoin at a later time expecting Convener privileges to continue. + +A meet-me conference would typically be specified as non-locked so that other nodes may join. A meet-me conference may optionally be created to require Password protection to prevent unwanted nodes from joining the conference. + +A node joining a meet-me conference would issue a GCC-Conference-Join request over the connection from the node to any MCU joined to the conference. Typically, a node does not know *a priori* the name of the conference to be joined. In this case, prior to joining the conference, a node may query the MCU for a list of conferences that are available to be joined. This is done by issuing a GCC-Conference-Query request. The response is a GCC-Conference-Query confirm which indicates the type of node to which the terminal is connected (i.e., an MCU in this case), and a list of all listed conferences to which that MCU is currently joined. This list includes the Conference Name of each conference, a Conference Name Modifier if one is needed, as well as other characteristics of the conference such as whether or not the conference is Password protected, which may be used to request a Password from the user prior to attempting to join the conference. Once the name of the conference is selected, the conference may be joined by issuing a GCC-Conference-Join request specifying the Conference Name of the desired conference, and if needed, the Conference Name Modifier. If the conference requires a Password, it is included in the join request. + +Note that it is typical that the case of a meet-me conference with no *a priori* knowledge of the conference to join is identical to the case of a point-to-point conference. That is, the sequence of events used in starting up the conference cannot be different from that of a point-to-point conference since the *a priori* knowledge in each case is the same. It is only the identification in the GCC-Conference-Query confirm that the directly connected node is an MCU and that there are ongoing conferences to be joined that allow a distinction to be made. + +In the case that the Conference Name is distributed to joining nodes out-of-band, a node may directly join the conference without first querying the available conferences by specifying the Conference Name in the GCC-Conference-Join request. If there are multiple independent MCUs to which nodes may connect to join a conference, it is possible that, due to naming conflicts, a Conference Name Modifier is needed on some MCUs. In this case, a node joining a conference when connected to one of these MCUs must specify the Conference Name Modifier for that MCU. As it may be difficult to determine this modifier without the use of the GCC-Conference-Query primitive, it is recommended that if there is any possibility of a naming conflict, GCC-Conference-Query should be used prior to attempting to join a meet-me conference. It is also recommended that a Conference Description be used when a meet-me conference is first created. In this case, it is more likely that multiple conferences with the same Conference Name may be distinguished by having different Conference Descriptions. In general, however, when creating a meet-me conference, it is better to choose a Conference Name which will be unique at all MCUs without the need of a Conference Name Modifier. + +#### **7.1.4.2 Call-out conference establishment** + +In call-out conference establishment, a conference is created locally at the MCU and the conference participants are called and invited to the conference by that MCU. The conference would typically be created specifying that it is a locked conference and may also be specified as unlisted. + +The convening MCU would then make physical connections to each of the terminals to participate in the conference followed by inviting each node in turn to the conference. This is done by issuing a GCC-Conference-Invite request to the node to be invited. Since the conference was created at the MCU, that MCU is the Top-GCC-Provider of a call-out conference. + +#### **7.1.4.3 Call-through conference establishment** + +A call-through conference is very similar to call-out case with the exception that the conference is initially created remotely by an initiating terminal. In this case, the terminal connects to the MCU and creates a conference using a GCC-Conference-Create request. As in the call-out case, it would typically be locked and unlisted. A call-through conference would typically be created as an automatically terminating conference indicating that the conference will be terminated when all nodes disconnect. Typically, a NULL Conference Name would be specified for a call-through conference since there is no need for nodes to explicitly join the conference. If there is already a conference at the convening node with a NULL conference name, the Node Controller would simply choose an arbitrary unique name to use as the Conference Name. In either case, the name need not be human readable since it will never be used for joining. + +#### **7.1.4.4 Point-to-point conference establishment** + +A point-to-point conference is distinct from the other varieties in that it involves only two terminal nodes with no MCU present. In the case where it is known which terminal is the calling terminal (the initiator of the physical connection) and which is the called terminal, a point-to-point conference may be established by the calling terminal first querying the called terminal by issuing a GCC-Conference-Query request. This allows the terminal to determine if the other node is a terminal, MCU, or multiport terminal without requiring *a priori* knowledge to that effect. The GCC-Conference-Query confirm generated in response to this request indicates, in the case of a point-to-point call, that the directly connected node is a user-terminal. Once it is known that the + +directly connected node is a terminal, the conference is established by the calling terminal by issuing a GCC-Conference-Create request to create a new conference or by creating a conference locally, and inviting the other terminal by issuing a GCC-Conference-Invite request. Typically, the conference would be specified with an arbitrary Conference Name such as "0", and would be locked, unlisted, and automatically terminating. + +In the case that it is not known by a node which terminal is the calling or called terminal, that terminal should issue GCC-Conference-Query request to determine whether the other node is the called or calling node (unless it has already received a GCC-Conference-Query indication which has this information). In the request, the Asymmetry Indicator parameter indicates that it is unknown whether the local node is the called or calling node. If the other node does have this knowledge about itself, it will so indicate in the resulting GCC-Conference-Query confirm. If so, it is now known which is the calling node and the appropriate actions are taken as described above. If neither node knows its called/calling status, the confirm (or the contents of a received GCC-Conference-Query indication) will specify the unknown setting. The unknown settings of this parameter include a 32-bit random number. In this case, the random number is used to break the resulting symmetry. The node which had generated the smaller of the two random numbers should be considered the called node and should not attempt to establish the conference. The node which generated the larger number should be considered the calling node and should attempt to establish the conference. + +If a terminal does have *a priori* knowledge that the call is point-to-point between two terminals (and in the case that it is known whether that terminal is the called or calling terminal), that terminal need not issue a GCC-Conference-Query request. Instead, if the terminal is the calling terminal, it may issue the GCC-Conference-Create request or the GCC-Conference-Invite request immediately. If it is the called terminal with this *a priori* knowledge, it may also skip the GCC-Conference-Query request and simply wait to receive a GCC-Conference-Create indication or GCC-Conference-Invite indication. If the far-end terminal does not have *a priori* knowledge of the connection type, it is possible that the local terminal will receive a GCC-Conference-Query indication from the far-end terminal to which it is required to respond. + +#### **7.1.4.5 Conference establishment among multiport terminals** + +A multiport terminal is a device which is, in general, to be treated as a terminal, but has the ability to establish connections to multiple nodes simultaneously as an MCU does. When a terminal or multiport terminal calls a node which it finds to be a multiport terminal (either through *a priori* knowledge or via the GCC-Conference-Query exchange), the action taken depends on whether or not there are conferences available on that multiport terminal and on the characteristics of those conferences. + +In general, it is typically desirable that a connection of this kind be made automatically, like a point-to-point call rather than like a meet-me conference. Specifically, if neither the called nor calling nodes are already part of conferences connecting them to other nodes, the call should be treated exactly as a point-to-point call. If the calling node already has an ongoing conference, it is typical that this node would simply invite the new node into the existing conference. + +If instead the called node has an ongoing conference, the action depends on whether that conference is locked or unlocked, listed or unlisted. If the conference is unlisted, without *a priori* information, the calling node would not be aware of its presence and would treat the call as if there were no conference present at that node (if it did have *a priori* information that an unlisted conference was present, it could join that conference). If the conference is locked, the calling node has no way to join that conference and again would treat the call as if that conference were not present. In either of these cases, once a new conference is established, the called node may choose to transfer the nodes connected to the previous conference into the new conference. If there are one or more listed conferences at the called node which are not locked, the calling node should assume that the called + +node is hosting a meet-me conference and would typically require a user to decide which one to join – in this case, the procedure would not be entirely automatic. + +If there are conferences present at both nodes, the calling node would normally either invite the called node into its conference, or would attempt to join the called node's conference. In either case, the multiport terminal with the existing conference that was not enlarged to include the other multiport terminal should transfer all subordinate nodes to the conference that it has newly become joined (or invited) to. + +Transferring nodes to the new conference in these cases may be done in one of two ways. The GCC-Conference-Transfer primitive may be used to command each of the nodes to disconnect from the current conference and join the new conference. This, of course, can only be done if the new conference is not locked, and if the requesting node had Transfer privilege for the previous conference (or was the convener of the previous conference). Alternatively, the GCC-Conference-Invite primitive could be used to invite the directly connected nodes to the new conference. Typically this would be done after disconnecting these nodes from the previous conference. If there were more nodes originally present than the directly connected nodes, it is the responsibility of the directly connected nodes, recursively, to invite the nodes directly connected to them into the new conference. That is, the invitations would propagate through the hierarchy of physically connected nodes. Nodes would typically do this; however, there is no assurance that this action would be taken. For this reason, the use of GCC-Conference-Transfer is a safer mechanism in the cases where it can be performed. + +## **7.2 The conference roster** + +The Conference Roster allows a node participating in a conference to learn what other nodes are participating in the same conference, and provides information about each node. Immediately after joining a conference (by means of either creating, joining, or being invited to the conference), the Node Controller at that node shall announce its presence to the conference by issuing a GCC-Conference-Announce-Presence request. The results of this request depend on the joining node's Node Category. + +For Conventional nodes (where all nodes that existed prior to the introduction of Node Categories are considered Conventional), the GCC Providers of the nodes in the conference exchange information needed to update the Conference Roster to include the newly-joined node. The updated Conference Roster or a delta update of the Conference roster is distributed to all nodes in the conference, generating a GCC-Conference-Roster-Report indication. A Conventional node joining a conference is not considered an active member of the conference until it has received a Conference Roster in which it is included. + +For Counted Nodes, the GCC Providers of the affected nodes in the conference exchange information needed to update the Conference Roster to include the newly-joined node. The updated Conference Roster or a delta update of the Conference roster is distributed to all Conventional nodes in the conference and to the Counted node joining the conference, generating a GCC-Conference-Roster-Report indication. A Counted node joining a conference is not considered an active member of the conference until it has received a Conference Roster in which it is included. + +Anonymous Nodes do not affect the Conference Roster. Regardless, their local Node Controllers are still required to announce their presence to the local GCC Provider. + +The information in the Conference Roster may be changed at any time during a conference by the Node Controller at any Conventional and Counted node. This is done by re-issuing a GCC-Conference-Announce-Presence request. This results in an updated roster being distributed to all nodes, generating another GCC-Conference-Roster-Report indication. + +As Conventional and Counted nodes leave a conference for any reason, a new Conference Roster is distributed by GCC, again generating a GCC-Conference-Roster-Report indication. + +### 7.2.1 Description of abstract services + +The following is a list of the primitives defined in this subclause and a brief summary of the function of each: + +- GCC-Conference-Announce-Presence – Used by the Node Controller to announce the presence of a node into a conference. Use of this primitive is required immediately after joining or being joined to any conference. +- GCC-Conference-Roster-Report – Generated by GCC in response to any change to the Conference Roster due to nodes either entering or leaving a conference. +- GCC-Conference-Roster-Inquire – Used by either the Node Controller or by Application Protocol Entities to retrieve the current Conference Roster at any time during a conference. + +#### 7.2.1.1 GCC-Conference-Announce-Presence + +Immediately after a node has joined any conference, it shall announce its presence to the conference using the primitive GCC-Conference-Announce-Presence request. The Node Controller is responsible for issuing this primitive. This primitive may be re-issued at any time during a conference if the included information has changed. Table 7-18 shows the parameters and types of this primitive. Figure 7-15 shows the sequence of events when using this primitive. + +NOTE – The Conference Roster includes the list of all terminals, and MCUs currently joined to a conference. A user display of the roster, as well as user indications of nodes entering and leaving the conference are likely to only include terminals and multiport terminals. The Node Type parameter of this primitive may be used to distinguish among these node types, excluding uninteresting node types from user displays. In addition, the Node Properties parameter also adds information as to the use of the device, specifying whether a node is a management device, and whether a node is a peripheral, subordinate to another node. Both of these characteristics may also be used by a system to determine whether or not to include a particular node in its display of conference participants. Typically, neither management devices, nor peripherals would be included in such a list. + +**Table 7-18 – GCC-Conference-Announce-Presence – +Types of primitives and their parameters** + +| Parameter | Request | Confirm | +|---------------------|---------|---------| +| Conference ID | M | M(=RQ) | +| Node Type | M | | +| Node Properties | M | | +| Node Name | O | | +| Participant Name(s) | O | | +| Site Information | O | | +| Network Address | O | | +| Alternative Node ID | O | | +| User Data | O | | +| Result | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Node Type*: The node type is either a terminal, MCU, or multiport terminal. + +*Node Properties:* Made up of two independent flags. One indicating whether or not the node is a management device (e.g., a reservation system), and the other indicating whether or not the node is a peripheral, subordinate to another node. + +*Node Name:* Unicode text string containing the name of this node (e.g., "London"). Maximum 255 characters. + +*Participant Name (s):* A list of Unicode text strings each containing the name of a meeting participant. Maximum 255 characters for each string. + +*Site Information:* A Unicode text string containing other information about the node. It may be used, for example, to indicate such things as the voice-phone or FAX numbers at the site. + +*Network Address:* Optional parameter to indicate the network address of this node. This parameter includes sub-fields which specify network type information followed by the actual network address or addresses. This parameter should be used if it is possible that the announcing node may later be attempted to be added to another conference via the GCC-Conference-Add primitive. This gives an MCU knowledge of the Network Address which may be compared to the Network Address of a node to be added to determine if a physical connection already exists. If this parameter is not included, it may not be possible to later add this node to another conference over the same physical connection. This parameter should also be used if it is possible that an initial point-to-point conference may be automatically re-routed through an MCU to add additional nodes. This parameter allows one of the original two nodes to re-connect with the other by use of a GCC-Conference-Add primitive through the MCU. + +*Alternative Node ID:* This field may be used to associate the announcing node (and its corresponding Node ID) with an alternative node ID which has been defined for some other purpose. This alternative node ID is not intended to represent IDs in the same numbering space as Node IDs, but rather a separate numbering scheme not specified by this Recommendation. For example, in the case of ISDN, for nodes supporting ITU-T Rec. H.243, the alternative node ID could be the H.243 site ID which is two octets in length. + +*User Data:* Optional user data which may be used for functions outside the scope of this Recommendation. Note that this data is stored within the Top GCC Provider as part of Conference Roster. Therefore, this parameter is not intended to contain large amounts of information. Doing so could risk being involuntarily ejected from the conference. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference. + +![Sequence diagram showing the GCC-Conference-Announce-Presence sequence of primitives between a Node Controller, GCC Provider, Top GCC Provider, and All Nodes Node Controller.](8bd7adf738ea4b7e65e0d6f67e122d55_img.jpg) + +``` +sequenceDiagram + participant NC as Node Controller + participant GP1 as GCC Provider + participant TGP as Top GCC Provider + participant GP2 as GCC Provider + participant ANNC as All Nodes Node Controller + + NC->>GP1: GCC-Conference-Announce-Presence request + GP1-->>TGP: + TGP-->>GP2: + GP2->>ANNC: GCC-Conference-Roster-Report indication + GP1->>NC: GCC-Conference-Announce-Presence confirm +``` + +The diagram illustrates the sequence of primitives for the GCC-Conference-Announce-Presence process. It involves four entities: Node Controller, GCC Provider, Top GCC Provider, and All Nodes Node Controller. The sequence is as follows: 1. The Node Controller sends a 'GCC-Conference-Announce-Presence request' to the GCC Provider. 2. The request is propagated through the GCC Providers to the Top GCC Provider. 3. A 'GCC-Conference-Roster-Report indication' is sent from a GCC Provider to the All Nodes Node Controller. 4. Finally, the GCC Provider sends a 'GCC-Conference-Announce-Presence confirm' message back to the original Node Controller. + +Sequence diagram showing the GCC-Conference-Announce-Presence sequence of primitives between a Node Controller, GCC Provider, Top GCC Provider, and All Nodes Node Controller. + +T.124(01-07)\_F7-15 + +**Figure 7-15 – GCC-Conference-Announce-Presence – Sequence of primitives** + +#### 7.2.1.2 GCC-Conference-Roster-Report + +Whenever the Conference Roster has changed for any reason (a new node entering the conference, a node leaving the conference, or updated information in a roster entry), the roster is distributed by GCC to all nodes by issuing a GCC-Conference-Roster-Report primitive to the Node Controller at each node. Table 7-19 shows the parameters and types of this primitive. Figure 7-16 shows the sequence of events when using this primitive. + +**Table 7-19 – GCC-Conference-Roster-Report – +Types of primitives and their parameters** + +| Parameter | Indication | +|-------------------|------------| +| Conference ID | M | +| Conference Roster | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Conference Roster*: A list of each node joined to the specified conference. The format of the Conference Roster is shown in Table 7-20. + +**Table 7-20 – Contents of the Conference Roster parameter** + +| Parameter | Description | +|--------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| List of Conference Nodes | A list of the Nodes joined to the conference along with information about each node. The contents of each entry in this list is shown in Table 7-22. | +| Instance Number | The instance number for the Conference Roster. This is a 16-bit number which is incremented modulo $2^{16}$ each time the contents of the Conference Roster changes. | +| Nodes Added Flag | A flag indicating whether one or more Nodes have been added to the Conference Roster since the last instance. This flag is not mutually exclusive of the Nodes Removed Flag. | +| Nodes Removed Flag | A flag indicating whether one ore more Nodes have been removed from the Conference Roster since the last instance. This flag is not mutually exclusive of the Nodes Added Flag. | + +![Sequence diagram showing a GCC Provider sending a GCC-Conference-Roster-Report indication to All Nodes Node Controller.](31ef15d175af5babdbf4d2fbac884c1b_img.jpg) + +``` + +sequenceDiagram + participant GCCProvider as GCC Provider + participant AllNodes as All Nodes Node Controller + GCCProvider->>AllNodes: GCC-Conference-Roster-Report indication + +``` + +The diagram illustrates the sequence of primitives for the GCC-Conference-Roster-Report. It shows a vertical line for the 'GCC Provider' on the left and an oval for the 'All Nodes Node Controller' on the right. A message arrow points from the GCC Provider to the All Nodes Node Controller, labeled 'GCC-Conference-Roster-Report indication'. + +Sequence diagram showing a GCC Provider sending a GCC-Conference-Roster-Report indication to All Nodes Node Controller. + +T.124(01-07)\_F7-16 + +**Figure 7-16 – GCC-Conference-Roster-Report – Sequence of primitives** + +#### 7.2.1.3 GCC-Conference-Roster-Inquire + +The GCC-Conference-Roster-Inquire request primitive returns the complete Conference Roster for the specified conference. This primitive is available to Application Protocol Entities as well as the Node Controller, allowing them to independently obtain a Conference Roster from their local GCC Provider. Table 7-21 shows the parameters and types of this primitive. Figure 7-17 shows the sequence of events when using this primitive. + +**Table 7-21 – GCC-Conference-Roster-Inquire – +Types of primitives and their parameters** + +| Parameter | Request | Confirm | +|------------------------|---------|---------| +| Conference ID | M | M(=) | +| Conference Name | | M | +| Conference Description | | C | +| Conference Roster | | M | +| Result | | M | + +*Conference Name:* The Conference Name as contained within the Conference Profile. + +*Conference Description:* The Conference Description as contained within the Conference Profile. This parameter is present, only if a Conference Description had been defined at the time of conference creation. + +*Conference ID:* Identifier of the conference to which the primitive refers. + +*Conference Roster:* A list of each node joined to the specified conference. The format of the Conference Roster is shown in Table 7-23. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference. + +**Table 7-22 – Contents of each entry in the List of Conference Nodes** + +| Parameter | Description | +|----------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Node ID | MCS User ID of the GCC Provider at this node. | +| Node ID of Superior Node (conditional) | MCS User ID of the GCC Provider at the node directly above this node in the connection hierarchy, if any (not present for the Top GCC Provider). | +| Node Type | The node type is either a terminal, MCU, or multiport terminal. | +| Node Properties | Made up of two independent flags. One indicating whether or not the node is a management device (e.g., a reservation system), and the other indicating whether or not the node is a peripheral, subordinate to another node. | +| Node Name (conditional) | Unicode text string containing the name of this node (e.g., "London"). Maximum 255 characters. | +| Participants Names (conditional) | A list of Unicode text strings each containing the name of a meeting participant. Maximum 255 characters for each string. | +| Site Information (conditional) | A Unicode text string containing other information about the node. It may be used, for example, to indicate such things as the voice-phone or FAX numbers at the site. | +| Network Address (conditional) | This parameter describes the logical connection used by the node to join the conference. Each portion of the logical connection is described | + +**Table 7-22 – Contents of each entry in the List of Conference Nodes** + +| Parameter | Description | +|-----------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| | in terms of network type, network address, transfer rate when relevant, and optionally a multimedia profile that shall be operated, a digital circuits aggregation algorithm when applicable, and the list of media (e.g., audio, video, data) that are concerned by this portion. In the GCC protocol, this parameter is reflected by ASN.1 structures NetworkAddress and NetworkAddressV2. See Annex B for the description and use of these. | +| Alternative Node ID (conditional) | This field is used to associate the announcing node (and its corresponding Node ID) with an alternative node ID which has been defined for some other purpose. This alternative node ID is not intended to represent IDs in the same numbering space as Node IDs, but rather a separate numbering scheme not specified by this Recommendation. For example, in the case of ISDN, for nodes supporting H.243, the alternative node ID could be the H.243 site ID which is two octets in length. | +| Node Category (conditional) | This field indicates the Node Category for the node. Conventional and Counted nodes are the only valid categories for this field because Anonymous nodes do not appear in a Conference Roster. | +| User Data (conditional) | Optional user data which may be used for functions outside the scope of this Recommendation. | + +**Table 7-23 – Contents of the Conference Roster parameter** + +| Parameter | Description | +|--------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| List of Conference Nodes | A list of the Nodes joined to the conference along with information about each node. The contents of each entry in this list is shown in Table 7-22. | +| Instance Number | The instance number for the Conference Roster. This is a 16-bit number which is incremented modulo $2^{16}$ each time the contents of the Conference Roster changes. | + +![Sequence diagram showing the GCC-Conference-Roster-Inquire sequence of primitives between a Node Controller or Application Protocol Entity and a GCC Provider.](30387053b5b3fede6873f6a46a9ca4a9_img.jpg) + +``` + +sequenceDiagram + participant NCAPE as Node Controller or +Application Protocol Entity + participant GCCP as GCC Provider + NCAPE->>GCCP: GCC-Conference- +Roster-Inquire request + GCCP-->>NCAPE: GCC-Conference- +Roster-Inquire confirm + +``` + +The diagram illustrates the sequence of primitives for the GCC-Conference-Roster-Inquire operation. It involves two entities: the Node Controller or Application Protocol Entity (represented by an oval) and the GCC Provider (represented by a vertical line). The sequence begins with a message labeled "GCC-Conference-Roster-Inquire request" sent from the Node Controller to the GCC Provider. This is followed by a return message labeled "GCC-Conference-Roster-Inquire confirm" sent from the GCC Provider back to the Node Controller. + +Sequence diagram showing the GCC-Conference-Roster-Inquire sequence of primitives between a Node Controller or Application Protocol Entity and a GCC Provider. + +T.124(01-07)\_F7-17 + +**Figure 7-17 – GCC-Conference-Roster-Inquire – Sequence of primitives** + +## 7.3 The application roster + +The Application Roster allows a node participating in a conference to learn what Application Protocol Entities are available at nodes in the conference, and provides sufficient information about these Application Protocol Entities to allow direct communication between Peer Application Protocol Entities to begin. The roster may include Application Protocol Entities that are based on standard Application Protocols as well as those based on non-standard Application Protocols. + +### 7.3.1 Contents of the application roster + +For each conference, a GCC Provider compiles a list of information associated with each Application Protocol Entity. These lists form the Local Application Roster which can be exchanged with other nodes as part of the Application Roster exchange procedure. This exchange will result in a list of information associated with all Application Protocol Entities in the entire conference collectively known as the Conference Application Roster. + +The Local Application Roster is held by each GCC Provider and stored in its local database. At an appropriate point in the set-up of a conference, a node can exchange its Local Application Roster with all other conference nodes and the GCC Provider will receive the Conference Application Roster which it will report to all Application Protocol Entities as well as the Node Controller. This exchange occurs within GCC and is apparent to Application Protocol Entities only through primitives that may be generated. Whether or not a GCC Provider exchanges its local Application Roster depends on the Node Category into which a node falls. For Conventional and Counted nodes, the Local Application Roster is exchanged. For Anonymous nodes, the Local Application Roster is not exchanged. + +The Local and Conference Application Rosters consist of the following components: + +- *Local Application Roster* – For each Application Protocol Entity which has enrolled with the local GCC Provider, the Local Application Roster includes a Session Key, an Application Record, and an Application Capabilities List. +- *Conference Application Roster* – For each Application Protocol Session, the Conference Application Roster includes the Session Key for that Session, an Application Capabilities List containing the negotiated capability set for the session, and the list of Application Protocol Entities enrolled in the session which includes, for each, the Node ID of the node at which that Application Protocol Entity had enrolled, an identifier which identifies the particular Application Protocol Entity within its local node, and an Application Record. + +Each set of Peer Application Protocol Entities – those within a single Application Protocol Session – are characterized by having enrolled using the same value of the Session Key. A Session Key is defined as follows: + +- *The Session Key* – An identifier used to uniquely identify an Application Protocol Session. A Session Key consists of two components. One component identifies the Application Protocol. The second component, which is optional, identifies a particular session of that Application Protocol. + +The first component of a Session Key, the Application Protocol Key, identifies either a standard or non-standard Application Protocol specification. Keys are structured so that any Application Protocol, whether standard or non-standard, may be defined to have a unique key with no possibility of conflict. Keys may be specified in one of two forms. A key may be specified as an ASN.1 type Object Identifier. This form of Key may be used to specify standard Application Protocols. The assignment of Object Identifier components for Standards and Recommendations is described in Annex B of [ITU-T X.680] and Annex C of [ITU-T X.680], respectively. Object Identifiers may also be used to specify non-standard Application Protocols in the case of national or private administrative authorities which have been directly or indirectly authorized by ISO or ITU. + +A key may also be specified as an ASN.1 type OCTET STRING interpreted in a manner similar to the pattern adopted in [ITU-T H.221] to designate non-standard commands and capabilities. In this case, the first two octets of the OCTET STRING define a country code, the second two octets define a manufacturer code. The first octet of the country code is assigned according to [ITU-T T.35]; the second octet and the manufacturer code are assigned nationally. Octets beyond this shall be freely chosen by the responsible manufacturer or national body. + +The second component of a Session Key is an optional Session ID. The Session ID is an MCS Channel ID which is used as the unique identifier of an Application Protocol Session and may be used as a communication channel by the Application Protocol Entities taking part in that session (as determined by the Application Protocol specification). To ensure uniqueness, this Channel ID shall remain allocated for the duration of the session. The lack of a Session ID in a Session Key of an active Application Protocol Entity identifies a distinct session – the Default Session. + +In the case of an inactive Application Protocol Session, the Session ID is not required. Its absence in this case may be interpreted as an indication of support for the indicated Application Protocol and the ability to invoke one or more Application Protocol Entities as part of any session, default or otherwise. + +Each Application Record contains the following parameters, some of which are optional: + +- *Active/Inactive Flag* – An Application Protocol Entity may enroll but not yet be ready to receive data (e.g., it has not yet joined the appropriate channels). To indicate this to other nodes, an Application Protocol Entity may enroll with this flag set to Inactive. This may be done to allow the Application Protocol Entity to make use of GCC services (such as the registry) in preparation for becoming active, or it may simply be to allow other nodes to become aware of the presence of this Application Protocol Entity without becoming active until it is known that there are like Application Protocol Entities at other nodes. When an inactive Application Protocol Entity becomes active, it may re-enroll setting the flag to Active. This flag may be changed by the Application Protocol Entity at any time by re-enrolling. +- *Application User ID* – The MCS User ID associated with the Session Key. The Application User ID is the only means by which a node can include another node as a participant when convening a private channel for that Application Protocol Session to use. This parameter is optional for Application Protocol Entities enrolled as inactive, but mandatory for active Application Protocol Entities. If it is not included because the Application Protocol Entity has not yet attached to the MCS Domain, it may later be added, once the Application Protocol Entity has attached, by re-enrolling. +- *Conducting Operation Capable* – This is a flag which indicates whether the Application Protocol Entity is capable of operating as a conducting Application Protocol Entity if the corresponding Application Protocol specification defines the procedures for such an Application Protocol Entity to follow. The GCC Provider within each node chooses no more than one Peer Application Protocol Entity per Application Protocol Session to include with this flag set in the exchanged Application Roster. If a node becomes the conference conductor, the designated Application Protocol Entity, if any, for each Application Protocol Session becomes the designated conducting Application Protocol Entity. This flag only applies to Active Application Protocol Entities. If the Active/Inactive flag is set to Inactive when enrolling, the Conducting Operation Capable flag is ignored and assumed by the GCC Provider to be FALSE. +- *Non-Collapsing Capabilities List* – This is an optional parameter which allows Application Protocol Entities to list capabilities (either standard or non-standard) which are to be maintained in the roster as part of the Application Record of each Application Protocol + +Entity rather than being collapsed by a set of rules as the capabilities listed in the Application Capabilities List would be. + +The Application Capabilities List is defined as follows: + +- *Application Capabilities List:* This is an optional parameter list which may be used to specifically list the capabilities of the Application Protocol Entity. While the capabilities themselves are Application Protocol–specific, they are listed along with information which allows GCC to determine the common capability set for the Application Protocol Session and inform the Peer Application Protocol Entities of this set. This avoids the need for a complete exchange of a full capability list between all nodes. Each capability in the capability list is tagged with a class specifier. The class specifier determines the rule that is applied to determine the common capability set. Table 7-24 lists all capability classes. Note that neither Counted or Anonymous nodes can affect the Conference Application Roster capabilities. + +**Table 7-24 – Capability combination rules** + +| Class | Description | +|------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Logical | If any Peer Application Protocol Entity in a conference indicates the use of this capability, the final capability list indicates the number of Peer Application Protocol Entities that have indicated this capability. | +| Unsigned-Minimum | The parameter octets are treated as a single unsigned integer. The final capability list indicates the minimum value among all Peer Application Protocol Entities which indicated this capability as well as the number of Peer Application Protocol Entities which have indicated this capability. | +| Unsigned-Maximum | The parameter octets are treated as a single unsigned integer. The final capability list indicates the maximum value among all Peer Application Protocol Entities which indicated this capability as well as the number of Peer Application Protocol Entities which have indicated this capability. | + +In addition to the basic classifications, it is also possible to nest capabilities. Nesting is not done explicitly, but rather is done by appropriate interpretation of the three capability classes. For example, an Application Protocol may define a particular capability, Y, to be conditional on a Logical capability, X. If the rule is applied within the Application Protocol specification that capability Y may only be issued if capability X had been issued, then the value of Y in the final capability set may be interpreted as, in the case of a Logical capability Y, the number of Peer Application Protocol Entities, among those which have capability X, which also have capability Y, and in the case of a numerical capability Y, the minimum or maximum value of Y among those Peer Application Protocol Entities which have capability X. Note that in the case of a numerical capability Y, if the number of Peer Application Protocol Entities which indicate the capability Y is less than the number of Peer Application Protocol Entities indicating the capability X, this indicates that some Peer Application Protocol Entities do not support a value of Y beyond its default value. In this case, the negotiated value of Y should be ignored. The negotiated value of Y is valid in this case only if the number of Peer Application Protocol Entities with both the X and Y capabilities are equal. + +### 7.3.2 Description of the application roster exchange process + +Each Application Protocol Entity makes its local GCC Provider aware of its presence through a GCCSAP over which it communicates with the GCC Provider. Creation and management of the GCCSAP is a local matter not covered by this Recommendation. + +Application Protocol Entities are made aware of the existence of a conference to which the node is joined by the GCC-Application-Permission-To-Enroll indication. Once an Application Protocol + +Entity has been made aware of an existing conference, it shall issue a GCC-Application-Enroll request to the GCC Provider. This enroll request may indicate that the Application Protocol Entity is enrolling itself in the conference (the enroll/un-enroll flag set to enroll), or it may indicate that it is not enrolling itself into the conference (the enroll/un-enroll flag set to un-enroll). In the latter case, the Application Record parameters need not be included in the primitive. Any time thereafter, until permission to enroll is revoked (upon receiving a GCC-Application-Permission-To-Enroll primitive with the grant/revoke flag set to revoke), an Application Protocol Entity which did not choose to initially enroll itself into the conference may enroll by issuing a GCC-Application-Enroll request. + +There are several parameters in the GCC-Application-Enroll request which, if used, require steps to be taken prior to issuing the GCC-Application-Enroll request. First is the Application User ID which is mandatory in the request if enrolling with the Active/Inactive flag is set to Active. To get an Application User ID, the Application Protocol Entity must first attach to the MCS Domain indicated in the GCC-Application-Permission-To-Enroll indication. This is done by issuing the MCS primitive MCS-Attach-User request. On reception of the MCS-Attach-User confirm, the Application Protocol Entity will have been allocated an Application User ID. This ID may be included in the GCC-Application-Enroll request. If the attachment to the domain should fail due to the connection to the domain being lost during the intervening time, the Application Protocol Entity shall assume that the node is no longer part of the conference and shall wait until receiving another GCC-Application-Permission-To-Enroll indication before proceeding further. When the node disconnects from the conference, the Application Protocol Entity will be notified directly by MCS that the attachment is no longer valid. The Application Protocol Entity shall assume that the node is no longer part of the conference and shall wait until receiving another GCC-Application-Permission-To-Enroll indication before proceeding further. If permission to enroll is revoked by a GCC-Application-Permission-To-Enroll primitive, the Application Protocol Entity shall not attempt to attach to the corresponding domain. + +The second such parameter is the optional Session ID which is part of the Session Key. The Session ID shall be formed from an MCS Channel ID (which is not a User ID). When enrolling into a session being invoked, the Session ID is obtained from the GCC-Application-Invoke indication. If joining a session already in progress, the Session ID may be obtained from the most recently received Application Roster. If creating a new session, then a new Channel ID may be allocated using an MCS-Channel-Join primitive or MCS-Channel-Convene primitive. + +As a consequence of a GCC-Application-Enroll request primitive, the GCC Provider creates a new entry in its Local Application Roster. If an entry already exists for an Application Protocol Entity, the contents of the Local Application Roster entry are modified to contain the new information, or in the case of the un-enroll flag being set, the entry is removed from the roster. + +At the start of a conference, the GCC Provider, after issuing the GCC-Application-Permission-To-Enroll primitive, waits for all Application Protocol Entities which are connected to the GCC Provider through a GCCSAP to issue a GCC-Application-Enroll primitive either enrolling, or indicating their explicit desire not to enroll. For Conventional and Counted nodes, once all Application Protocol Entities have responded, the GCC Provider exchanges the Local Application Roster with the other nodes in the conference. During a conference in progress, any changes to the Local Application Roster are immediately exchanged with other nodes. Note that only Conventional nodes can create new Application Protocol Sessions (by being the first node to exchange a Local Application Roster associated with a non-existent session). GCC Providers at Counted nodes must therefore wait until a session associated with a particular Application Protocol Entity exists before it can exchange its associated Local Application Roster information. + +For Anonymous nodes, the Local GCC Provider will never exchange its Local Application Roster. Instead, the GCC Provider uses the enrolment information to determine which Application Protocol Sessions the local Application Protocol Entities are interested in. When a Conference Application + +Roster associated with one of these APEs is received by the local GCC Provider, that Conference Application Roster is immediately delivered to the interested APE. + +In any of the cases above, whenever a new exchange takes place, initiated by any node, a new Conference Application Roster is generated and distributed to all interested nodes. The GCC Provider issues the entire roster to the Node Controller, and issues portions of this roster to enrolled Application Protocol Entities using the GCC-Application-Roster-Report indication primitive. To an Application Protocol Entity, the roster report includes the portion of the Conference Application Roster which specifically applies to that Application Protocol Session (and may include other portions as well). For each session, this is in the form of a list. Each entry in the list includes the Node ID and Application Protocol Entity ID which, together, identify the Application Protocol Entity, and the Application Record for that Application Protocol Entity. It may also include the Application Capabilities List for the Application Protocol Session. This is a list of the common capabilities for this Application Protocol Session based on application of the capability class rules to the capabilities announced by all Peer Conventional node Application Protocol Entities. In the case of the node controller, the GCC-Application-Roster-Report indication includes the entire Conference Application Roster. That is, for each entry in the list, it includes the node identifier, and the Application Records for all Application Protocols enrolled at that node. It also may include, for each Application Protocol, an Application Capabilities List. + +An Application Protocol Entity is not considered part of a conference until it has received a GCC-Application-Roster-Report indication in which it is included in the Application Roster. If, at any time, an Application Protocol Entity which had previously been enrolled receives a GCC-Application-Roster-Report indication in which it is no longer included, that Application Protocol Entity shall be considered no longer enrolled. The Application Protocol Entity may attempt to re-enroll by issuing a GCC-Application-Enroll request. At Counted and Anonymous nodes, it is the responsibility of the local GCC Provider to insert an Application Record (associated with a local Application Protocol Entity that is trying to enroll with a session), into the roster before delivering the associated GCC-Application-Roster-Report indication. + +At any time an Application Protocol Entity may remove itself from the Application Roster by issuing a GCC-Application-Enroll request primitive with the enroll/un-enroll flag set to un-enroll. This removes the Application Record for that Application Protocol Entity from the Local Application Roster as well as from the Conference Application Roster at all nodes in the conference. + +At any time during a conference, an Application Protocol Entity or the Node Controller may request a portion of the Conference Application Roster. For each node in the conference, all Application Records which match the Session Key given in the GCC-Application-Roster-Inquire request are returned. Using a null key will result in the complete Conference Application Roster. + +An Application Protocol Entity or Node Controller may attempt to remotely invoke an Application Protocol Entity at another node. This is done by issuing a GCC-Application-Invoke request. This request may optionally include a specified list of destination nodes. The corresponding GCC-Application-Invoke indication is received by the Node Controller at the specified destination nodes (or all nodes if no destination is specified). The node controller may optionally respond to this indication by invoking a Peer Application Protocol Entity which may then enroll itself in the conference. + +### 7.3.3 Description of abstract services + +The following is a list of the primitives defined in this subclause and a brief summary of the function of each: + +- GCC-Application-Permission-To-Enroll – Generated by GCC and issued to all Application Protocol Entities which have made the GCC Provider aware of their presence whenever the local node has been joined to a conference. This indicates that the Application Protocol Entity may enroll. With the Revoke flag set, this revokes the ability to enroll when the node is no longer joined to the conference. +- GCC-Application-Enroll – Used by Application Protocol Entities to establish (or terminate) communications with other Peer Application Protocol Entities in a conference. Use of this primitive generates (or modifies, or removes) an entry in the Application Roster exchanged with other nodes. +- GCC-Application-Roster-Report – Generated by GCC in response to any change in the Application Roster due to Application Protocol Entities enrolling or un-enrolling or nodes entering or leaving a conference. +- GCC-Application-Roster-Inquire – Used by either the Node Controller or by Application Protocol Entities to retrieve all or a portion of the current Application Roster at any time during a conference. +- GCC-Application-Invoke – Used to signal a set of other nodes in a conference to invoke an Application Protocol Entity for a particular session of an Application Protocol. + +#### 7.3.3.1 GCC-Application-Permission-To-Enroll + +The primitive GCC-Application-Permission-To-Enroll indication tells a local Application Protocol Entity that the local node is now joined to the specified conference and that the Application Protocol Entity may enroll itself with that conference. This primitive is also used to revoke such permission if the local node is no longer joined to a conference. While an MCS-attached Application Protocol Entity will receive notification from MCS when the conference terminates at that node, an Application Protocol Entity which has chosen not to attach (or to enroll) will not necessarily receive such notification. This primitive indicates to such an Application Protocol Entity that it may no longer enroll with that conference or attach to the corresponding MCS Domain. The GCC-Application-Permission-To-Enroll indication is issued by a GCC Provider to all Application Protocol Entities which have made the GCC Provider aware of their presence only after the node has been successfully joined to a conference. Table 7-25 shows the parameters and types of this primitive. Figure 7-18 shows the sequence of events when using this primitive. + +**Table 7-25 – GCC-Application-Permission-To-Enroll – +Types of primitives and their parameters** + +| Parameter | Indication | +|-------------------|------------| +| Conference ID | M | +| Grant/Revoke Flag | M | +| Node Category | C | + +*Conference ID*: Identifier of the Conference to which the Application Protocol Entity may enroll. This parameter is equal to the MCS Domain to which the Application Protocol Entity may attach. + +*Grant/Revoke Flag*: This flag indicates whether the Application Protocol Entity is being given permission to enroll, or if that permission is being revoked. + +*Node Category*: This field informs the APE which Node Category was established for this node, within this conference, when the node joined. + +![Sequence diagram showing a message from GCC Provider to Application Protocol Entity labeled GCC-Application-Permission-to-Enroll indication.](a4de02b04a1a8f6cb8121ac2e11bf95a_img.jpg) + +``` + +sequenceDiagram + participant GCCProvider as GCC Provider + participant APPE as Application Protocol Entity + GCCProvider->>APPE: GCC-Application-Permission-to-Enroll indication + +``` + +T.124(01-07)\_F7-18 + +Sequence diagram showing a message from GCC Provider to Application Protocol Entity labeled GCC-Application-Permission-to-Enroll indication. + +**Figure 7-18 – GCC-Application-Permission-to-Enroll – Sequence of primitives** + +#### 7.3.3.2 GCC-Application-Enroll + +The GCC-Application-Enroll request primitive is issued by an Application Protocol Entity to establish itself as part of the specified conference. This primitive shall be issued in response to a GCC-Permission-To-Enroll indication, although the Application Protocol Entity may set the Enroll/Un-enroll flag to Un-enroll, indicating that it does not wish to enroll at this time. At any time until permission to enroll is revoked, the Application Protocol Entity may enroll, re-enroll (to change entries in its Application Record), or un-enroll. If an Application Protocol Entity which is already un-enrolled attempts to un-enroll, the request is accepted with a successful result, but no change is made to the status of that Application Protocol Entity. When an Application Protocol Entity is enrolled, the associated parameters form the Application Record which is broadcast to the conference during the Application Roster exchange. Application Protocol Entities that are not enrolled will not be available to any local or remote participants and will not receive GCC-Application-Roster-Report indications. Table 7-26 shows the parameters and types of this primitive. Figure 7-19 shows the sequence of events when using this primitive. + +**Table 7-26 – GCC-Application-Enroll – Types of primitives and their parameters** + +| Parameter | Request | Confirm | +|----------------------------------|---------|---------| +| Conference ID | M | M(=) | +| Session Key | M | M(=) | +| Active or Inactive | M | | +| Application User ID | C | | +| Conducting Operation Capable | O | | +| Start-up Channel | O | | +| Non-Collapsing Capabilities List | O | | +| Application Capabilities List | O | | +| Enroll or Un-enroll | M | | +| Application Protocol Entity ID | | C | +| Node ID | | C | +| Result | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Session Key*: Unique identifier of a particular Application Protocol Session. This corresponds to the identifier of the Application Protocol, optionally concatenated with a Session ID. + +*Active or Inactive*: This flag is used to indicate whether the enrolling Application Protocol Entity is fully active (indicating that it can perform tasks required by the specification of the corresponding Application Protocol), or inactive. An Application Protocol Entity might indicate itself to be inactive in the case that it must enroll to make use of certain GCC services, but is not yet fully operational (e.g., it has not yet joined dynamic channels, but must first check the registry to determine which channels to join). Alternatively, it might enroll inactive to indicate support for the corresponding Application Protocol without the need to become active until it is known that there are like Application Protocol Entities at other nodes. The specific meaning of this flag shall be defined in the specification of each Application Protocol. + +*Application User ID*: MCS User ID given to this Application Protocol Entity. This parameter is optional in the case of inactive Application Protocol Entities, but is mandatory for active Application Protocol Entities. It is an error for an Application Protocol Entity that is enrolled with an MCS User ID to re-enroll with a different MCS User ID. This parameter is not needed in the case of un-enrolling. + +*Conducting Operation Capable*: This is a flag which indicates whether the Application Protocol Entity is capable of operating as a conducting Application Protocol Entity if the corresponding Application Protocol specification defines the procedures for such an Application Protocol Entity to follow. The GCC Provider within each node chooses no more than one Peer Application Protocol Entity per Application Protocol Session to include with this flag set in the exchanged Application Roster. If a node becomes the conference conductor, the designated Application Protocol Entity, if any, for each Application Protocol Session becomes the designated conducting Application Protocol Entity. The enrolling Application Protocol Entity shall not assume itself to be in the designated conducting role unless it determines that its corresponding entry in the received Application Roster has this flag set. This flag only applies to Active Application Protocol Entities. If the Active/Inactive flag is set to Inactive when enrolling, the Conducting Operation Capable flag is ignored and assumed by the GCC Provider to be FALSE. + +*Start-up Channel*: This is an optional parameter which may take on the values Static, Dynamic Multicast, Dynamic Private, or Dynamic UserId. This parameter specifies the type of MCS Channel the Application Protocol Entity will use for start-up sequencing. The exact interpretation of this parameter as well as any requirements for the use of this parameter are Application Protocol-specific. In some cases, certain of these channel types may not be valid for particular Application Protocols. + +*Non-Collapsing Capabilities List*: This is an optional parameter which allows Application Protocol Entities to list capabilities (either standard or non-standard) which are to be maintained in the roster as part of the Application Record of each Application Protocol Entity rather than being collapsed by a set of rules as the capabilities listed in the Application Capabilities List would be. Each entry in this list includes a capability ID which may be either standard or non-standard, as well as a data field for Application Protocol-specific data. + +*Application Capabilities List*: This is an optional list of Application Protocol-specific capabilities. Each capability is tagged with a class identifier indicating the rule to be applied by GCC in determining the common capability set for this Application Protocol Session. The class identifiers are one of the choices listed in Table 7-24. + +*Enroll or Un-enroll*: This is a flag used to indicate whether the Application Protocol Entity wishes to add, or change its Application Record (enroll), or to remove its Application Record (un-enroll). When an Application Protocol Entity has received a GCC-Permission-To-Enroll indication, it shall respond with a GCC-Enroll-Request. If that Application Protocol Entity wishes not to enroll, it shall set this flag to Un-enroll. + +**Application Protocol Entity ID:** Present only in the case of a successful new enroll (not in the case when already enrolled, in the case of an unsuccessful enroll, or in the case of an un-enroll). An identifier which uniquely identifies the Application Protocol Entity within the local node. This corresponds to the same parameter in each entry of the Application Roster. This allows an Application Protocol Entity to determine if it is included in subsequent updates of the Application Roster. + +**Node ID:** Present only in the case of a successful enroll (not in an unsuccessful enroll or an un-enroll). This provides the enrolling Application Protocol Entity the Node ID of its local node. This helps to allow the Application Protocol Entity to find its corresponding entry in received Application Rosters to determine when it actually becomes enrolled into the conference. The combination of the Node ID and the Application Protocol Entity ID uniquely determine the Application Protocol Entity. + +**Result:** An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, not permitted to change MCS User ID. + +![Sequence diagram showing the GCC-Application-Enroll process. The diagram involves five lifelines: Application Protocol Entity, GCC Provider, Top GCC Provider, GCC Provider, and All Nodes Peer Application Protocol Entities. The sequence is: 1. Application Protocol Entity sends 'GCC-Application-Enroll request' to GCC Provider. 2. A dashed line connects GCC Provider to Top GCC Provider. 3. A dashed line connects Top GCC Provider to GCC Provider. 4. GCC Provider sends 'GCC-Application-Roster-Report indication' to All Nodes Peer Application Protocol Entities. 5. All Nodes Peer Application Protocol Entities sends 'GCC-Application-Enroll confirm' back to Application Protocol Entity.](694df81535f89c7bfb9ef0df6f130dc0_img.jpg) + +``` + +sequenceDiagram + participant APE as Application Protocol Entity + participant GP1 as GCC Provider + participant TGP as Top GCC Provider + participant GP2 as GCC Provider + participant ANPE as All Nodes Peer Application Protocol Entities + + APE->>GP1: GCC-Application-Enroll request + GP1-->TGP: + TGP-->GP2: + GP2->>ANPE: GCC-Application-Roster-Report indication + ANPE-->>APE: GCC-Application-Enroll confirm + +``` + +T.124(01-07)\_F7-19 + +Sequence diagram showing the GCC-Application-Enroll process. The diagram involves five lifelines: Application Protocol Entity, GCC Provider, Top GCC Provider, GCC Provider, and All Nodes Peer Application Protocol Entities. The sequence is: 1. Application Protocol Entity sends 'GCC-Application-Enroll request' to GCC Provider. 2. A dashed line connects GCC Provider to Top GCC Provider. 3. A dashed line connects Top GCC Provider to GCC Provider. 4. GCC Provider sends 'GCC-Application-Roster-Report indication' to All Nodes Peer Application Protocol Entities. 5. All Nodes Peer Application Protocol Entities sends 'GCC-Application-Enroll confirm' back to Application Protocol Entity. + +**Figure 7-19 – GCC-Application-Enroll – Sequence of primitives** + +#### 7.3.3.3 GCC-Application-Roster-Report + +This primitive is used by a GCC Provider to send to each enrolled Application Protocol Entity as well as to the Node Controller some or all of the Conference Application Roster. A GCC-Application-Roster-Report indication may be generated automatically by a GCC Provider whenever the GCC Provider finds out that a change in any portion of the roster has occurred. This may happen, for example, as a result of a GCC-Application-Enroll request, or on detection of an Application Protocol Entity detaching from the conference, or a node leaving the conference altogether. When any portion of the roster has changed for any Application Protocol Entity, the GCC-Application-Roster-Report indication shall be issued to the Node Controller. The GCC Provider shall issue a GCC-Application-Roster-Report indication to an active Application Protocol Entity when any portion of the roster has changed for any Peer Application Protocol Entity. In this case it is required to include only the portion of the roster which applies to the corresponding Application Protocol Session. The GCC Provider may also issue a GCC-Application-Roster-Report indication to an Application Protocol Entity at other times (such as when entries other than for Peer Application Protocol Entities have changed) and may include in the indication primitive portions of the roster beyond those corresponding to Peer Application Protocol Entities. For inactive Application Protocol Entities, if the Application Protocol Entity has enrolled with a specific Session ID, the same rules apply as for an active Application Protocol Entity. For an inactive Application Protocol Entity which has enrolled with no Session ID, the GCC Provider shall + +issue a GCC-Application-Roster-Report when the contents of the roster have changed for all Application Protocol Sessions which are based on the same Application Protocol as the enrolled Application Protocol Entity. Table 7-27 shows the parameters and types of this primitive. When issued to the Node Controller, each of the Application Protocol-specific parameters (all except the Conference ID) is repeated separately for each Application Protocol Session. Figure 7-20 shows the sequence of events when using this primitive. + +**Table 7-27 – GCC-Application-Roster-Report – Types of primitives and their parameters** + +| Parameter | Indication | +|----------------------------|------------| +| Conference ID | M | +| Updated Application Roster | M | + +*Conference ID*: Identifier of the MCS Domain corresponding to the indicated conference. + +*Updated Application Roster*: The updated Application Roster includes the information shown in Table 7-28 for each Application Protocol Session being indicated by the indication. + +**Table 7-28 – Contents of the updated Application Roster for each Application Protocol Session** + +| Parameter | Description | +|------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Session Key | The Session Key (including the Session ID, if any) designating the particular Application Protocol Session. | +| Application Protocol Entity List Updated Flag | A flag indicating whether the Application Protocol Entity List for this Session Key has been updated in this report. If so, the Application Protocol Entity List is included as the following parameter. | +| Application Protocol Entity List (conditional) | A list of the Application Protocol Entities enrolled in the conference as part of this Application Protocol Session including an Application Record for each. The contents of each entry in this list is shown in Table 7-29. | +| Instance Number | The instance number for the Application Roster for this Session Key. This is a 16-bit number which is incremented modulo $2^{16}$ each time the contents of the Application Roster changes for this Session Key. This allows Application Protocol Entities to perform operations with respect to a particular capability set which may be in the process of changing avoiding any race conditions. | +| Peer Entities Added Flag | A flag indicating whether one or more Peer Application Protocol Entities have been added to the Application Roster at any node since the last instance. This flag is not mutually exclusive of the Peer Entities Removed Flag. | +| Peer Entities Removed Flag | A flag indicating whether one or more Peer Application Protocol Entities have been removed from the Application Roster at any node since the last instance. This flag is not mutually exclusive of the Peer Entities Added Flag. | +| Application Capabilities List Updated Flag | A flag indicating whether the Application Capabilities List for this Session Key has been updated in this report. If so, the Application Capabilities List is included as the following parameter. | +| Application Capabilities List (conditional) | The fully collapsed Application Capabilities List for this Session Key. | + +**Table 7-29 – Contents of each entry of the Application Protocol Entity List** + +| Parameter | Description | +|------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Node ID | Node ID identifying the node at which the Application Protocol Entity has enrolled. | +| Application Protocol Entity ID | An identifier which uniquely identifies the Application Protocol Entity within the node specified by the Node ID. | +| Active/Inactive Flag | A flag indicating whether the enrolled Application Protocol Entity is inactive or active. | +| Application User ID (conditional) | The MCS User ID associated with the enrolled Application Protocol Entity. | +| Conducting Operation Capable | This is a flag which indicates whether the Application Protocol Entity is capable of operating as a conducting Application Protocol Entity if the corresponding Application Protocol specification defines the procedures for such an Application Protocol Entity to follow. There is no more than one Peer Application Protocol Entity per node with this flag set. If a node becomes the conference conductor, the designated Application Protocol Entity at that node, if any, for this Application Protocol Session becomes the designated conducting Application Protocol Entity. | +| Start-up Channel (conditional) | This parameter, if present, may take on the values Static, Dynamic Multicast, Dynamic Private, or Dynamic UserId. This parameter indicates the type of MCS Channel the Application Protocol Entity will use for start-up sequencing. The exact interpretation of this parameter is Application Protocol-specific. In some cases, certain of these channel types may not be valid for particular Application Protocols. | +| Non-Collapsing Capabilities List (conditional) | This is a list of Application Protocol-specific capabilities (either standard or non-standard) which are maintained in the roster as part of the Application Record of each Application Protocol Entity. | + +![Sequence diagram showing a GCC-Application-Roster-Report indication from the GCC Provider to the Node Controller and Application Protocol Entities.](8ab30dbff406204a68c59ae7c1b77413_img.jpg) + +``` + +sequenceDiagram + participant GCC as GCC Provider + participant Node as Node Controller and +Application Protocol Entities + GCC->>Node: GCC-Application-Roster-Report indication + +``` + +The diagram illustrates a sequence of primitives between two entities. On the left, a vertical line represents the 'GCC Provider'. On the right, an oval represents the 'Node Controller and Application Protocol Entities'. An arrow points from the GCC Provider to the Node Controller and Application Protocol Entities, labeled 'GCC-Application-Roster-Report indication'. + +T.124(01-07)\_F7-20 + +Sequence diagram showing a GCC-Application-Roster-Report indication from the GCC Provider to the Node Controller and Application Protocol Entities. + +**Figure 7-20 – GCC-Application-Roster-Report – Sequence of primitives** + +#### 7.3.3.4 GCC-Application-Roster-Inquire + +An Application Protocol Entity may request a portion of the Conference Application Roster corresponding to a single Application Protocol Session, a group of these, or all Application Protocol Entities, using the GCC-Application-Roster-Inquire request primitive. This information is returned by GCC in the GCC-Application-Roster-Inquire confirm primitive. Table 7-30 shows the parameters and types of this primitive. Figure 7-21 shows the sequence of events when using this primitive. + +**Table 7-30 – GCC-Application-Roster-Inquire – Types of primitives and their parameters** + +| Parameter | Request | Confirm | +|--------------------|---------|---------| +| Conference ID | M | M(=) | +| Session Key | M | M(=) | +| Application Roster | | M | +| Result | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Session Key*: Unique identifier of an Application Protocol Session. This may be a partial Session Key or a null key, indicating that the Application Information for all Application Protocol Entities is desired. + +*Application Roster*: The Application Roster includes a list of roster entries for each Application Protocol Session specified by a Session Key whose octets match the Session Key in the request up to the length of the Session Key in the request, and if a Session ID is specified as part of the Session Key, those with the identical Session ID. For each matched entry, the information returned is shown in Table 7-31. + +**Table 7-31 – Contents of the Application Roster for each Application Protocol Session** + +| Parameter | Description | +|----------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Session Key | The Session Key (including the Session ID, if any) designating the particular Application Protocol Session. | +| Application Protocol Entity List | A list of the Application Protocol Entities enrolled in the conference as part of this Application Protocol Session including an Application Record for each. The contents of each entry in this list is shown in Table 7-28. | +| Instance Number | The instance number for the Application Roster for this Session Key. This is a 16-bit number which is incremented modulo $2^{16}$ each time the contents of the Application Roster changes. This allows Application Protocol Entities to perform operations with respect to a particular capability set which may be in the process of changing avoiding any race conditions. | +| Application Capabilities List | The fully collapsed Application Capabilities List for this Session Key. | + +*Result*: An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference. + +![Sequence diagram showing the interaction between a Node Controller or Application Protocol Entity and a GCC Provider. The Node Controller sends a 'GCC-Application-Roster-Inquire request' to the GCC Provider, and the GCC Provider responds with a 'GCC-Application-Roster-Inquire confirm'.](32d36dfe7dc75b7c63f8edf0f28e4009_img.jpg) + +``` + +sequenceDiagram + participant NCE as Node Controller or +Application Protocol Entity + participant GCCP as GCC Provider + NCE->>GCCP: GCC-Application- +Roster-Inquire request + GCCP-->>NCE: GCC-Application- +Roster-Inquire confirm + +``` + +T.124(01-07)\_F7-21 + +Sequence diagram showing the interaction between a Node Controller or Application Protocol Entity and a GCC Provider. The Node Controller sends a 'GCC-Application-Roster-Inquire request' to the GCC Provider, and the GCC Provider responds with a 'GCC-Application-Roster-Inquire confirm'. + +**Figure 7-21 – GCC-Application-Roster-Inquire – Sequence of primitives** + +#### 7.3.3.5 GCC-Application-Invoke + +At the specified nodes, the indication form of this primitive is issued to the Node Controller which may invoke the specified Application Protocol Entities. For each listed Application Protocol Entity, this indication indicates the desire to create a new Application Protocol Entity with the Session Key as specified in the request which would then enroll actively into the conference, becoming part of the corresponding Application Protocol Session. Alternatively, if an inactive Application Protocol Entity already exists at a destination node with the identical Session Key, receipt of this indication indicates the desire to make that Application Protocol Entity re-enroll in the active state. If an Application Protocol Entity exists at a destination node with the identical Session Key which is already in the active state, this indication may be ignored. Table 7-32 shows the parameters and types of this primitive. Figure 7-22 shows the sequence of events when using this primitive. Note that Application Protocol Entities can only be invoked at Conventional and Counted nodes. Also, a GCC-Application-Invoke can only be initiated from a Conventional node. A Conventional node should have already created the session passed in the Invoke request before a Counted node is invoked. + +**Table 7-32 – GCC-Application-Invoke – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|----------------------------------------------|---------|------------|---------| +| Conference ID | M | M | M(=) | +| Application Protocol Entity Invoke List | M | M(=) | M(=) | +| Destination Nodes (List of Node IDs or NULL) | O | | | +| Invoking Node ID | | M | | +| Result | | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Application Protocol Entity Invoke List*: This is a list of one or more Application Protocol Entities to be invoked. The contents of each entry in this list are shown in Table 7-33. + +**Table 7-33 – Contents of each entry in the Application Protocol Entity Invoke List** + +| Parameter | Description | +|--------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Session Key | The Session Key (including the Session ID, if any) designating the particular Application Protocol Session to invoke. | +| Expected Capability Set | This is an optional list of application capabilities (in the same form as the Application Capabilities List) which indicates the expected set of capabilities that the Application Protocol Entity to be invoked must have. If the Application Protocol Entity at a particular node cannot satisfy this, it shall not be invoked at that node. If this parameter is not included, no constraints are placed on the invoked Application Protocol Entity. Note that the capabilities class definitions are used to determine the interpretation of this expected capability set, but are not interpreted by GCC as they are in the case of the Application Capabilities List. For a capability of the Unsigned-MAX class, the invoked Application Protocol Entity must have a capability less-than-or-equal-to the specified capability, while for an Unsigned-MIN class, the invoked Application Protocol Entity must have a capability greater-than-or-equal-to the specified capability. For a capability in the Logical class, the invoked Application Protocol Entity simply must have the identical capability. | +| Start-up Channel (conditional) | Either Static, Dynamic Multicast, Dynamic Private, or Dynamic UserId. This parameter specifies the type of MCS Channel the Application Protocol Entity should assume for use when invoking. In some cases, certain of these channel types may not be valid for particular Application Protocols. If an invalid setting is used, the Application Protocol Entity shall not be invoked. | +| Mandatory/Optional Flag | This flag indicates whether this Application Protocol Entity must be invoked in order to invoke the other Application Protocol Entities in this list. This flag is used by the invoking node to indicate that the destination nodes should only invoke the Application Protocol Entities in this list if all of the Application Protocol Entities marked as Mandatory can successfully be invoked. | + +*Destination Nodes (List of Node IDs or NULL):* List of Node IDs identifying GCC Providers to which the request should go, or null, to indicate it should go to all nodes in the conference designated by the Conference ID. + +*Invoking Node ID:* The Node ID of the node which initiated the corresponding GCC-Application-Invoke request. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference. + +![Sequence diagram showing the GCC-Application-Invoke process between a Node Controller or Application Protocol Entity, two GCC Providers, and Destination Nodes Node Controller.](f78d2e126f00fcc5d8d9797ca410cc09_img.jpg) + +``` + +sequenceDiagram + participant NCAPE as Node Controller or +Application Protocol Entity + participant GP1 as GCC Provider + participant GP2 as GCC Provider + participant DNN as Destination Nodes +Node Controller + + NCAPE->>GP1: GCC-Application-Invoke +request + GP1-->>GP2: GCC-Application-Invoke +indication + GP2->>DNN: GCC-Application-Invoke +indication + DNN-->>GP1: GCC-Application-Invoke +confirm + GP1-->>NCAPE: GCC-Application-Invoke +confirm + +``` + +T.124(01-07)\_F7-22 + +Sequence diagram showing the GCC-Application-Invoke process between a Node Controller or Application Protocol Entity, two GCC Providers, and Destination Nodes Node Controller. + +**Figure 7-22 – GCC-Application-Invoke – Sequence of primitives** + +## 7.4 The Application Registry + +The Application Registry is a functional component of GCC. The registry offers a set of functions to Application Protocol Entities which operate on a central database located at the Top GCC Provider. The contents of the registry are unique to a single conference. The significance of information stored in the registry database is defined by Application Protocols. The central repository can assist in establishing communication among Application Protocol Entities. It can help peers to discover a common Channel ID on which to communicate, a common Token ID to regulate exclusive access, or a common parameter setting (a parameter is a registry entry with an Application Protocol-specific use). It offers an alternative to the static reservation of Channel IDs, Token IDs, and other parameter values. By supporting dynamic discovery, the Application Registry can facilitate the introduction of new features, standardized or non-standardized, that enhance audiographic and audiovisual conferencing. The registry also includes a general purpose service for allocation of numeric handles which are globally unique within a conference. + +### 7.4.1 Registry keys + +The indexes used to store and retrieve entries in the registry database are Application Protocol-specified keys. Both standard and non-standard keys are allowed. Standard keys are allocated by Recommendations like this. Non-standard keys may be proprietary. Both are structured to avoid conflicts in the choice of key values. + +Registry keys consist of a Session Key as defined in 7.3.1 in combination with a Resource ID. The Session Key used for any registry operation requiring a Registry Key shall be identical to the Session Key of an Application Protocol Session present in the Application Roster (with either active or inactive members). The Resource ID is of ASN.1 type OCTET STRING. The Resource ID allows a single Application Protocol Entity to make use of multiple Registry Keys. The value of the Resource IDs are defined by the specifications of the Application Protocols which make use of them. + +### 7.4.2 Ownership and persistence + +The registry yields ownership of a Registry Key to the first Application Protocol Entity that requests to store an item there via either the GCC-Registry-Register-Channel, GCC-Registry-Assign-Token, or GCC-Registry-Set-Parameter request primitives. A Conventional node is the only Node Category allowed to have ownership of a registry entry. + +In the case of a Parameter registry item, when the parameter is created, its owner may specify the scope of Application Protocol Entities allowed to modify the value of that entry. The owner may specify either owner, session, or public modification rights – the parameter may be modifiable by + +the owner only (as in the case of Channels and Tokens), by all Peer Application Protocol Entities (those within the same Application Protocol Session), or by any Application Protocol Entity in the conference, respectively. Modification of the contents of a parameter by an Application Protocol Entity other than the owner does not alter the identity of the owner of that entry. The owner of a parameter may at any time re-define the scope of modification rights. If another node attempts to modify the modification rights as part of issuing a GCC-Registry-Set-Parameter request, the rights will not be modified, although the parameter will be set to the requested value if the requester had modification rights. + +For all registry item types (Channel, Token, or Parameter), ownership is required to delete the entry. An entry, once deleted, has no owner and may be taken over by a different Application Protocol Entity. + +Registry entries are not deleted automatically when the owner un-enrolls from the conference. Their content persists unchanged indefinitely. However, ownership of an entry is removed when the owner un-enrolls. This allows a surviving Application Protocol Entity to modify (for a Parameter entry only) or delete an orphaned entry if its usefulness has expired. The first Application Protocol Entity that requests to store an item in an orphaned Parameter entry becomes its new owner. + +When all Application Protocol Entities in the session that corresponds to the Session Key used to form the Registry Key for a registry entry become un-enrolled, that registry entry is automatically deleted. + +### **7.4.3 Dynamic allocation** + +MCS distinguishes between static and dynamic Channel IDs. The latter comprise User IDs, private Channel IDs, and assigned Channel IDs. Dynamic Channel IDs are created and deleted directly by Application Protocol Entities, separately from their use of registry services. The Application Registry stores dynamic Channel IDs in a central repository for retrieval by other Application Protocol Entities. It does not test or operate on these Channel IDs with MCS primitives. + +MCS makes no distinction between static and dynamic Token IDs. To maintain similar semantics, an artificial division is imposed by GCC. Token IDs 1 to 16 383 are designated static and are reserved for assignment by other specifications. Token IDs 16 384 to 65 535 are designated dynamic and are allocated by the Top GCC Provider upon request, as part of creating an entry in the registry database. When the associated entry is deleted, the Token ID it held is made available for reassignment. The registry does not invoke MCS primitives, like grab and release, on the Token IDs it assigns. It merely chooses specific ID values and disseminates them. Application Protocol Entities are free to operate on assigned Token IDs according to their own logic. + +### **7.4.4 Description of abstract services** + +The following is a list of the primitives defined in this subclause and a brief summary of the function of each: + +- GCC-Registry-Register-Channel – Used by Application Protocol Entities to register the Channel ID of an MCS dynamic channel. Application Protocol Entities may examine the entry using GCC-Registry-Retrieve-Entry to determine if a node has already registered the Channel ID, and if so, retrieve the value of the Channel ID. Only Conventional nodes are allowed to register channels. +- GCC-Registry-Assign-Token – Used by Application Protocol Entities to allocate a dynamic token and register the assigned Token ID. Application Protocol Entities may examine the entry using GCC-Registry-Retrieve-Entry to determine if a node has already registered the Token ID, and if so, retrieve the value of the Token ID. Only Conventional nodes are allowed to assign a token. + +- GCC-Registry-Set-Parameter – Used by Application Protocol Entities to set a value in the registry database which may be examined or modified from any node in a conference. Only Conventional nodes are allowed to set a registry parameter. +- GCC-Registry-Retrieve-Entry – Used by Application Protocol Entities to extract the current contents of any registry entry. +- GCC-Registry-Delete-Entry – Used by Application Protocol Entities to remove an entry in the registry database. Only Conventional nodes are allowed to delete a registry entry. +- GCC-Registry-Monitor – Used by Application Protocol Entities to enable (or disable) monitoring of a registry entry. Once enabled, the indication form of this primitive notifies the requesting Application Protocol Entities of any changes to the content of the entry (including deletion). Any Node Category can monitor the registry. +- GCC-Registry-Allocate-Handle – Used to generate a 32-bit Handle which is unique within the scope of a single conference. Any Node Category can allocate a handle. + +For a particular requester, the order of registry request primitives, the resulting action at the Top GCC Provider (if successful), and their associated confirm primitives is preserved. + +#### 7.4.4.1 GCC-Registry-Register-Channel + +The GCC-Registry-Register-Channel request primitive may be issued by an Application Protocol Entity at a Conventional node to inform Application Protocol Entities at other nodes that a particular MCS channel has been designated for use by the Application Protocol Entity in the manner indicated by the Registry Key. Once any Application Protocol Entity registers using a particular Registry Key, Application Protocol Entities at other nodes may find out if a channel has been registered for this key (and if so, the value of the channel ID) by issuing the GCC-Registry-Retrieve-Entry request primitive specifying the Registry Key in question. Once a channel is registered, if any Application Protocol Entity attempts to register using the same Registry Key (including the owner), their attempt will be rejected with an indication that this Registry Key has already been used. Table 7-34 shows the parameters and types of this primitive. Figure 7-23 shows the sequence of events when using this primitive. + +**Table 7-34 – GCC-Registry-Register-Channel – Types of primitives and their parameters** + +| Parameter | Request | Confirm | +|---------------|---------|---------| +| Conference ID | M | M(=) | +| Registry Key | M | M(=) | +| Channel ID | M | | +| Registry Item | | C | +| Owner | | C | +| Result | | M | + +*Conference ID:* Identifier of the conference to which the primitive refers. + +*Registry Key:* The database index at which the item is to be stored. + +*Channel ID:* A dynamic channel ID (user ID, private, or assigned) specified by the Application Protocol Entity. + +*Registry Item:* The value of the entry after the request has taken effect. If the request is successful, this is the value of the parameter, if not successful due to inconsistent type or index already owned, this is the value prior to the request. It is either a Channel ID, Token ID, Parameter Value, or None if the entry is vacant (both the type and the value, if any, are indicated by this parameter). This parameter is not present if the confirm is a locally-generated error condition. + +*Owner:* This parameter indicates the current owner of this registry entry. If owned, this parameter includes the Node ID of the node at which the owner resides and the Entity ID of the owning Application Protocol Entity. This parameter also indicates if the entry is not owned. This parameter is not present if the confirm is a locally generated error condition. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, registry full, index already exists, inconsistent type, invalid requester. + +![Sequence diagram for GCC-Registry-Register-Channel showing interactions between Application Protocol Entity, GCC Provider, Top GCC Provider, and All Nodes Monitoring Application Protocol Entities.](b1784a5cbeeb3d9fb9e60b333019c721_img.jpg) + +``` + +sequenceDiagram + participant APE as Application Protocol Entity + participant GP1 as GCC Provider + participant TGP as Top GCC Provider + participant GP2 as GCC Provider + participant AN as All Nodes Monitoring Application Protocol Entities + + APE->>GP1: GCC-Registry-Register-Channel request + GP1->>TGP: + TGP->>GP2: + GP2->>AN: GCC-Registry-Monitor indication + TGP->>GP1: + GP1->>APE: GCC-Registry-Register-Channel confirm + +``` + +T.124(01-07)\_F7-23 + +Sequence diagram for GCC-Registry-Register-Channel showing interactions between Application Protocol Entity, GCC Provider, Top GCC Provider, and All Nodes Monitoring Application Protocol Entities. + +**Figure 7-23 – GCC-Registry-Register-Channel – Sequence of primitives** + +#### 7.4.4.2 GCC-Registry-Assign-Token + +The GCC-Registry-Assign-Token request primitive may be issued by an Application Protocol Entity at a Conventional node to assign a token to be associated with a particular Registry Key. If the request is successful, the token ID is returned as a parameter in the confirm primitive. Once any Application Protocol Entity gets a token assigned using a particular Registry Key, Application Protocol Entities at other nodes may find out if a token has been assigned for this key (and if so, the value of the Token ID) by issuing the GCC-Registry-Retrieve-Entry request primitive specifying the Registry Key in question. Once the token is assigned, if any Application Protocol Entity attempts to get a token assigned using the same Registry Key (including the owner), their attempt will be rejected with an indication that this Registry Key has already been used. Table 7-35 shows the parameters and types of this primitive. Figure 7-24 shows the sequence of events when using this primitive. + +**Table 7-35 – GCC-Registry-Assign-Token – Types of primitives and their parameters** + +| Parameter | Request | Confirm | +|---------------|---------|---------| +| Conference ID | M | M(=) | +| Registry Key | M | M(=) | +| Token ID | | C | +| Registry Item | | C | +| Owner | | C | +| Result | | M | + +*Conference ID:* Identifier of the conference to which the primitive refers. + +*Registry Key:* The database index at which the item is to be stored. + +*Token ID:* A dynamic token ID (16 384 or greater) assigned by the Top GCC Provider. This parameter is not present if the confirm is a locally-generated error condition. + +*Registry Item:* The value of the entry after the request has taken effect. If the request is successful, this is the value of the parameter, if not successful due to inconsistent type or index already owned, this is the value prior to the request. It is either a Channel ID, Token ID, Parameter Value, or None if the entry is vacant (both the type and the value, if any, are indicated by this parameter). This parameter is not present if the confirm is a locally-generated error condition. + +*Owner:* This parameter indicates the current owner of this registry entry. If owned, this parameter includes the Node ID of the node at which the owner resides and the Entity ID of the owning Application Protocol Entity. This parameter also indicates if the entry is not owned. This parameter is not present if the confirm is a locally-generated error condition. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, registry full, index already exists, inconsistent type, invalid requester. + +![Sequence diagram showing the GCC-Registry-Assign-Token process. An Application Protocol Entity sends a GCC-Registry-Assign-Token request to a GCC Provider. The GCC Provider sends a dashed message to the Top GCC Provider. The Top GCC Provider sends a dashed message to another GCC Provider. This second GCC Provider sends a GCC-Registry-Monitor indication to All Nodes Monitoring Application Protocol Entities. Finally, the GCC Provider sends a GCC-Registry-Assign-Token confirm back to the Application Protocol Entity.](64cda8ce20067bc360ce2f3a5c9352b7_img.jpg) + +``` + +sequenceDiagram + participant APE as Application Protocol Entity + participant GP1 as GCC Provider + participant TGP as Top GCC Provider + participant GP2 as GCC Provider + participant ANM as All Nodes Monitoring Application Protocol Entities + + APE->>GP1: GCC-Registry-Assign-Token request + GP1-->>TGP: + TGP-->>GP2: + GP2->>ANM: GCC-Registry-Monitor indication + GP1-->>APE: GCC-Registry-Assign-Token confirm + +``` + +T.124(01-07)\_F7-24 + +Sequence diagram showing the GCC-Registry-Assign-Token process. An Application Protocol Entity sends a GCC-Registry-Assign-Token request to a GCC Provider. The GCC Provider sends a dashed message to the Top GCC Provider. The Top GCC Provider sends a dashed message to another GCC Provider. This second GCC Provider sends a GCC-Registry-Monitor indication to All Nodes Monitoring Application Protocol Entities. Finally, the GCC Provider sends a GCC-Registry-Assign-Token confirm back to the Application Protocol Entity. + +**Figure 7-24 – GCC-Registry-Assign-Token – Sequence of primitives** + +#### 7.4.4.3 GCC-Registry-Set-Parameter + +The GCC-Registry-Set-Parameter request primitive may be issued by an Application Protocol Entity at a Conventional node to set or modify the value of a registry parameter. If the registry entry had been designated to be monitored using the GCC-Registry-Monitor request primitive, each successful GCC-Registry-Set-Parameter request results in a GCC-Monitor-Indication to Application Protocol Entities at all nodes in the conference which have enabled monitoring for this entry. If a registry entry exists for a particular key, a request to set a parameter shall only be accepted if the entry is already a parameter. Table 7-36 shows the parameters and types of this primitive. Figure 7-25 shows the sequence of events when using this primitive. + +**Table 7-36 – GCC-Registry-Set-Parameter – Types of primitives and their parameters** + +| Parameter | Request | Confirm | +|---------------------|---------|---------| +| Conference ID | M | M(=) | +| Registry Key | M | M(=) | +| Parameter Value | M | | +| Registry Item | | C | +| Owner | | C | +| Modification Rights | O | C | +| Result | | M | + +*Conference ID:* Identifier of the conference to which the primitive refers. + +*Registry Key:* The database index at which the item is to be stored. + +*Parameter Value:* An octet string specified by the Application Protocol Entity. + +*Registry Item:* The value of the entry after the request has taken effect. If the request is successful, this is the value of the parameter; if not successful due to inconsistent type, this is the value prior to the request. It is either a Channel ID, Token ID, Parameter Value, or None if the entry is vacant (both the type and the value, if any, are indicated by this parameter). This parameter is not present if the confirm is a locally-generated error condition. + +*Owner:* This parameter indicates the current owner of this registry entry. If owned, this parameter includes the Node ID of the node at which the owner resides and the Entity ID of the owning Application Protocol Entity. This parameter also indicates if the entry is not owned. If successful completion of this primitive results in the requester becoming the owner of this entry, the requester is indicated as the new owner in the confirm primitive. This parameter is not present if the confirm is a locally-generated error condition. + +*Modification Rights:* This optional parameter specifies the scope of Application Protocol Entities allowed to make modifications to the value of this registry entry. The value of this parameter may be either Owner, Session, or Public. The Owner setting specifies that only the owner (as long as the entry is owned) may modify this entry. The Session setting specifies that any Application Protocol Entity which is part of the same Application Protocol Session as the owner may modify this entry. The Public setting specifies that any Application Protocol Entity enrolled in the conference may modify this entry. If this parameter is not present when the entry is first created, a value of Public is assumed. If not present at other times, its value is left unchanged. Only the owner of this registry entry (as long as the entry is owned) can change the modification rights. If a non-owner attempts to change the modification rights, this change will not take place; however, any modification to the parameter entry itself will occur as long as the requester has modification rights. In the confirm primitive, this parameter is present independent of whether it was in the request primitive and indicates the actual modification rights. This parameter is not present if the confirm is a locally-generated error condition. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, registry full, inconsistent type, invalid requester. + +![Sequence diagram for GCC-Registry-Set-Parameter showing interactions between Application Protocol Entity, GCC Provider, Top GCC Provider, and All Nodes Monitoring Application Protocol Entities.](5cc4a2ef554f31ea0577731931007fff_img.jpg) + +``` + +sequenceDiagram + participant APE as Application Protocol Entity + participant GP as GCC Provider + participant TGP as Top GCC Provider + participant GPC as GCC Provider + participant ANMAPE as All Nodes Monitoring Application Protocol Entities + + APE->>GP: GCC-Registry-Set-Parameter request + GP-->>TGP: + TGP-->>GPC: + GPC->>ANMAPE: GCC-Registry-Monitor indication + ANMAPE-->>TGP: + TGP-->>GP: + GP-->>APE: GCC-Registry-Set-Parameter confirm + +``` + +T.124(01-07)\_F7-25 + +Sequence diagram for GCC-Registry-Set-Parameter showing interactions between Application Protocol Entity, GCC Provider, Top GCC Provider, and All Nodes Monitoring Application Protocol Entities. + +**Figure 7-25 – GCC-Registry-Set-Parameter – Sequence of primitives** + +#### 7.4.4.4 GCC-Registry-Retrieve-Entry + +The GCC-Registry-Retrieve-Entry request primitive may be issued by an Application Protocol Entity to determine the contents of a single registry entry. This primitive may be issued at any time and will indicate the contents of the entry as well as whether the entry is a channel ID, a token ID, a parameter, or if the entry is empty. Table 7-37 shows the parameters and types of this primitive. Figure 7-26 shows the sequence of events when using this primitive. + +**Table 7-37 – GCC-Registry-Retrieve-Entry – Types of primitives and their parameters** + +| Parameter | Request | Confirm | +|---------------------|---------|---------| +| Conference ID | M | M(=) | +| Registry Key | M | M(=) | +| Registry Item | | C | +| Owner | | C | +| Modification Rights | | C | +| Result | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Registry Key*: The database index of the entry to be retrieved. + +*Registry Item*: A Channel ID, Token ID, Parameter Value, or None if the entry is vacant (both the type and the value, if any, are indicated by this parameter). This parameter is not present if the confirm is a locally-generated error condition. + +*Owner*: This parameter indicates the current owner of this registry entry. If owned, this parameter includes the Node ID of the node at which the owner resides and the Entity ID of the owning Application Protocol Entity. This parameter also indicates if the entry is not owned. This parameter is not present if the confirm is a locally-generated error condition. + +*Modification Rights*: This parameter, included only in the case of Parameter entries, indicates the scope of Application Protocol Entities allowed to make modifications to the value of this registry entry. The value of this parameter may be either Owner, Session, or Public. The Owner setting specifies that only the owner (as long as the entry is owned) may modify this entry. The Session setting specifies that any Application Protocol Entity which is part of the same Application Protocol Session as the owner may modify this entry. The Public setting specifies that any Application Protocol Entity enrolled in the conference may modify this entry. If this parameter is not present + +when the entry is first created, a value of Public is assumed. This parameter is not present if the confirm is a locally-generated error condition. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, entry not found, invalid conference. + +![Sequence diagram showing the GCC-Registry-Retrieve-Entry process between an Application Protocol Entity, a GCC Provider, and a Top GCC Provider.](4a2b39fa33747a6553031cfe1e0947fa_img.jpg) + +The diagram illustrates the sequence of primitives for the GCC-Registry-Retrieve-Entry process. It involves three entities: Application Protocol Entity, GCC Provider, and Top GCC Provider. The Application Protocol Entity sends a 'GCC-Registry-Retrieve-Entry request' to the GCC Provider. The GCC Provider then sends a 'GCC-Registry-Retrieve-Entry confirm' back to the Application Protocol Entity. A dashed line connects the GCC Provider and the Top GCC Provider, indicating a relationship or data flow between them. + +T.124(01-07)\_F7-26 + +Sequence diagram showing the GCC-Registry-Retrieve-Entry process between an Application Protocol Entity, a GCC Provider, and a Top GCC Provider. + +**Figure 7-26 – GCC-Registry-Retrieve-Entry – Sequence of primitives** + +#### **7.4.4.5 GCC-Registry-Delete-Entry** + +The GCC-Registry-Delete-Entry request primitive may be issued by an Application Protocol Entity to remove a registry entry. Removal of a registry entry is only allowed by the Application Protocol Entity which owns that entry (unless the last owner disconnected from the conference and no new owner has been assigned) and must be issued from a Conventional node. If the registry entry had been designated to be monitored using the GCC-Registry-Monitor request primitive, a successful GCC-Registry-Delete-Entry request results in a GCC-Monitor-Indication to Application Protocol Entity at all nodes in the conference which have enabled monitoring for this entry with a NULL Registry Item parameter to indicate that the entry has been deleted. Table 7-38 shows the parameters and types of this primitive. Figure 7-27 shows the sequence of events when using this primitive. + +**Table 7-38 – GCC-Registry-Delete-Entry – Types of primitives and their parameters** + +| Parameter | Request | Confirm | +|---------------|---------|---------| +| Conference ID | M | M(=) | +| Registry Key | M | M(=) | +| Result | | M | + +*Conference ID:* Identifier of the conference to which the primitive refers. + +*Registry Key:* The database index of the entry to be vacated, removing any item previously stored. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, index already owned by another GCC Provider. + +![Sequence diagram for GCC-Registry-Delete-Entry showing interactions between Application Protocol Entity, GCC Provider, Top GCC Provider, and All Nodes Monitoring Application Protocol Entities.](e8f5117fb031f413a836525061addd61_img.jpg) + +``` + +sequenceDiagram + participant APE as Application Protocol Entity + participant GP as GCC Provider + participant TGP as Top GCC Provider + participant GPC as GCC Provider + participant ANMAPE as All Nodes Monitoring Application Protocol Entities + + APE->>GP: GCC-Registry-Delete-Entry request + GP-->>TGP: + TGP-->>GPC: + GPC->>ANMAPE: GCC-Registry-Monitor indication + ANMAPE-->>GP: + GP-->>APE: GCC-Registry-Delete-Entry confirm + +``` + +T.124(01-07)\_F7-27 + +Sequence diagram for GCC-Registry-Delete-Entry showing interactions between Application Protocol Entity, GCC Provider, Top GCC Provider, and All Nodes Monitoring Application Protocol Entities. + +**Figure 7-27 – GCC-Registry-Delete-Entry – Sequence of primitives** + +#### 7.4.4.6 GCC-Registry-Monitor + +GCC provides a mechanism for continuously monitoring particular registry entries of any type to determine if they have been changed (either altered, deleted, changed owners, or in the case of a parameter entry, changed modification rights) without the need for continuous polling. The GCC-Registry-Monitor request primitive may be used by an Application Protocol Entity to enable (or disable) monitoring of a particular registry entry. While enabled, the requesting Application Protocol Entity is notified of all changes to this entry via the GCC-Registry-Monitor indication primitive. An indication will be generated as a result of any modification of the contents of the registry entry or deletion of the entry. Only registry entries which exist may be monitored. Once an entry has been deleted, if it is recreated, the monitor request must be re-issued to begin monitoring again. Table 7-39 shows the parameters and types of this primitive. Figure 7-28 shows the sequence of events when using the request form of this primitive. + +NOTE – Particular GCC Provider implementations may choose not to keep track of which Application Protocol Entities have enabled or disabled monitoring for each entry. In that case, Application Protocol Entities may receive GCC-Registry-Monitor indications for entries that they have not requested to be monitored, or for entries for which they specifically disabled monitoring. + +**Table 7-39 – GCC-Registry-Monitor – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|---------------------|---------|------------|---------| +| Conference ID | M | M | M(=RQ) | +| Enable/Disable | M | | M(=) | +| Registry Key | M | M | M(=RQ) | +| Registry Item | | M | | +| Owner | | M | | +| Modification Rights | | C | | +| Result | | | M | + +*Conference ID:* Identifier of the conference to which the primitive refers. + +*Enable/Disable:* TRUE to deliver indications of registry contents; FALSE to suppress indications. + +*Registry Key:* The database index of an entry to be monitored (in the request/confirm), or that has changed (in the indication). + +*Registry Item:* A Channel ID, Token ID, Parameter Value, or None indicating that the entry has been deleted (both the type and the value, if any, are indicated by this parameter). + +*Owner:* This parameter indicates the current owner of this registry entry. If owned, this parameter includes the Node ID of the node at which the owner resides and the Entity ID of the owning Application Protocol Entity. This parameter also indicates if the entry is not owned. This parameter is not present if the confirm is a locally-generated error condition. + +*Modification Rights:* This parameter, included only in the case of Parameter entries, indicates the scope of Application Protocol Entities allowed to make modifications to the value of this registry entry. The value of this parameter may be either Owner, Session, or Public. The Owner setting specifies that only the owner (as long as the entry is owned) may modify this entry. The Session setting specifies that any Application Protocol Entity which is part of the same Application Protocol Session as the owner may modify this entry. The Public setting specifies that any Application Protocol Entity enrolled in the conference may modify this entry. If this parameter is not present when the entry is first created, a value of Public is assumed. This parameter is not present if the confirm is a locally-generated error condition. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, registry entry does not exist. + +![Sequence diagram showing the GCC-Registry-Monitor sequence of primitives between an Application Protocol Entity, a GCC Provider, and a Top GCC Provider.](28f2f470a7b2446ae5f525123534383c_img.jpg) + +``` +sequenceDiagram + participant APE as Application Protocol Entity + participant GP as GCC Provider + participant TGP as Top GCC Provider + + APE->>GP: GCC-Registry-Monitor request + GP-->>TGP: + TGP-->>GP: + GP-->>APE: GCC-Registry-Monitor confirm +``` + +The diagram illustrates the sequence of primitives for the GCC-Registry-Monitor operation. It involves three entities: Application Protocol Entity (represented by an oval), GCC Provider (represented by a vertical line), and Top GCC Provider (represented by a vertical line). The sequence is as follows: 1. The Application Protocol Entity sends a 'GCC-Registry-Monitor request' to the GCC Provider. 2. The GCC Provider sends a message to the Top GCC Provider (indicated by a dashed line). 3. The Top GCC Provider sends a message back to the GCC Provider (indicated by a dashed line). 4. The GCC Provider sends a 'GCC-Registry-Monitor confirm' message back to the Application Protocol Entity. + +T.124(01-07)\_F7-28 + +Sequence diagram showing the GCC-Registry-Monitor sequence of primitives between an Application Protocol Entity, a GCC Provider, and a Top GCC Provider. + +**Figure 7-28 – GCC-Registry-Monitor – Sequence of primitives** + +#### 7.4.4.7 GCC-Registry-Allocate-Handle + +The GCC-Registry-Allocate-Handle request primitive may be issued by an Application Protocol Entity at a Conventional node to request that a numerical value (or list of values) be allocated to that Application Protocol Entity which is globally unique within the scope of a single conference. Handles are allocated by the Top GCC Provider in increasing numerical order in the order that requests are received. Blocks of handles are also allocated in increasing numerical order. As a result, only the first handle in a block is returned if the number of handles is more than one. Table 7-40 shows the parameters and types of this primitive. Figure 7-29 shows the sequence of events when using this primitive. + +**Table 7-40 – GCC-Registry-Allocate-Handle – Types of primitives and their parameters** + +| Parameter | Request | Confirm | +|-------------------|---------|---------| +| Conference ID | M | M(=) | +| Number of Handles | M | M(=) | +| First Handle | | M | +| Result | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Number of Handles*: The number of handles requested to be allocated and returned in the confirm primitive. This may range from 1 to 1024. + +*First Handle*: 32-bit unsigned integer value. If the number of requested handles is equal to one, this is the value of the allocated handle. If the number of handles is greater than one, the set of allocated handles are those contiguous values (modulo $2^{32}$ ) that range from the value of First Handle, through the value (First Handle + Number of Handles) mod $2^{32}$ . + +*Result*: An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, no handles available, too many handles requested. + +![Sequence diagram showing the GCC-Registry-Allocate-Handle sequence of primitives between three entities: Application Protocol Entity, GCC Provider, and Top GCC Provider.](e38f0349f1b6094626cbfeab7105f029_img.jpg) + +``` + +sequenceDiagram + participant APE as Application Protocol Entity + participant GP as GCC Provider + participant TGP as Top GCC Provider + + APE->>GP: GCC-Registry-Allocate-Handle request + GP-->>TGP: + TGP-->>GP: + GP-->>APE: GCC-Registry-Allocate-Handle confirm + +``` + +The diagram illustrates the sequence of primitives for the GCC-Registry-Allocate-Handle operation. It involves three entities: the Application Protocol Entity (represented by an oval), the GCC Provider (represented by a vertical line), and the Top GCC Provider (represented by a vertical line). The sequence begins with the Application Protocol Entity sending a 'GCC-Registry-Allocate-Handle request' to the GCC Provider. A dashed line then connects the GCC Provider to the Top GCC Provider, indicating a message exchange. Finally, the GCC Provider sends a 'GCC-Registry-Allocate-Handle confirm' back to the Application Protocol Entity. + +Sequence diagram showing the GCC-Registry-Allocate-Handle sequence of primitives between three entities: Application Protocol Entity, GCC Provider, and Top GCC Provider. + +T.124(01-07)\_F7-29 + +**Figure 7-29 – GCC-Registry-Allocated-Handle – Sequence of primitives** + +## 7.5 Conference conductorship + +GCC provides a method for allowing a Conventional node to become a conductor for a conference. A token is used by GCC to determine whether a conference is conducted or non-conducted. The Node Controller at a node may acquire the Conductor token by issuing a GCC-Conductor-Assign request primitive. When any node successfully acquires the Conductor token, the conference is placed in Conducted Mode. The Node Controller as well as all Application Protocol Entities at all nodes in the conference are made aware when a conference switches into Conducted Mode by means of a GCC-Conductor-Assign indication. This indication also indicates which node has become the conductor. + +Whether a particular conference may operate in conducted mode or not is determined when the conference is created. If the Conference Conductible flag had been set, the conference may be placed in conducted mode. If not, any attempt to place the conference in conducted mode will be rejected. + +A node may release conductorship and return the conference into Non-conducted Mode by issuing a GCC-Conductor-Release request primitive. The Node Controller as well as all Application Protocol Entities at all nodes in the conference are made aware when a conference switches into Non-conducted Mode by means of a GCC-Conductor-Release indication. + +A node which is currently the conductor of a conference may pass conductorship directly to another node without placing the conference in Non-Conducted mode during the transition by issuing a GCC-Conductor-Give request specifying the desired recipient node. If the recipient accepts conductorship, the Node Controller as well as all Application Protocol Entities at all nodes in the conference are made aware of this transition by means of a GCC-Conductor-Assign indication which indicates which node is the new conductor. A node may explicitly request from the conductor that conductorship be given to it by issuing a GCC-Conductor-Please request primitive. The current conductor may choose to give the requesting node conductorship, or may ignore the request. + +The Node Controller as well as Application Protocol Entities at any node may also inquire as to which node, if any, currently holds the Conductor token by using the GCC-Conductor-Inquire request primitive. + +When an Application Protocol Entity is made aware that the conference to which it is joined is in Conducted Mode, it shall immediately begin operating according to its Conducted Mode behaviour as prescribed by the specification of the corresponding Application Protocol. When an Application Protocol Entity is made aware that the conference to which it is joined is in Non-conducted mode, it shall immediately begin operating according to its Non-conducted Mode behaviour as prescribed by the specification of the corresponding Application Protocol. A typical Application Protocol specification may, for example, state that the Application Protocol Entity at any node when in Conducted Mode must request permission from the Peer Application Protocol Entity at the conductor before taking any action, while in Non-conducted Mode, no such permission is required. However, the behaviour defined by Application Protocol specifications while in Conducted or Non-conducted Mode is a matter outside of the scope of this Recommendation. + +### **7.5.1 Description of abstract services** + +The following is a list of the primitives defined in this subclause and a brief summary of the function of each: + +- GCC-Conductor-Assign – Used by a Node Controller at a Conventional node to request conductorship of a conference. When a new node becomes conductor, the indication form of this primitive is used to announce this to all Node Controllers in the conference as well as to all Application Protocol Entities at all nodes in the conference. +- GCC-Conductor-Release – Used by a Node Controller at a Conventional node to release conductorship of a conference. When any node releases conductorship, the indication form of this primitive is used to announce this to all Node Controllers in the conference as well as to all Application Protocol Entities at all nodes in the conference. +- GCC-Conductor-Please – Used by a Node Controller at a Conventional node to request that conductorship be given to it from the current conductor. +- GCC-Conductor-Give – Used by a Node Controller at a Conventional node to pass conductorship to specified node. +- GCC-Conductor-Inquire – Used by a Node Controller or an Application Protocol Entity to determine whether the conference is currently conducted nor non-conducted, and if conducted, the Node ID of the current conductor. +- GCC-Conductor-Permission-Ask – Used by a Node Controller to request permission for Application Protocol Entities at that node to take actions which, in conducted-mode, require permission from the conductor. + +- GCC-Conductor-Permission-Grant – Used by the Node Controller at the conducting node to indicate which subset of nodes in a conference have been granted conducted-mode permission. + +#### 7.5.1.1 GCC-Conductor-Assign + +During non-conducted mode the Node Controller at any Conventional node has the possibility to issue a request to become conductor, by issuing a GCC-Conductor-Assign request primitive. The receipt of a GCC-Conductor-Assign confirm primitive indicates whether the requester has become the conductor or not, depending on the result parameter within the primitive. A successful GCC-Conductor-Assign request shall be accompanied by GCC-Conductor-Assign indications to all Node Controllers in the conference as well as to all enrolled Application Protocol Entities at all nodes in the conference signalling that the conference has become conducted, and giving information about the identity of the conductor. The indication form of this primitive may also be issued to an Application Protocol Entity upon enrolling into a conference to inform it that the conference is in conducted mode. The order of GCC-Conductor-Assign and GCC-Conductor-Release indications represents the actual order of conductorship transitions. Table 7-41 shows the parameters and types of this primitive. Figure 7-30 shows the sequence of events when using this primitive. + +NOTE – If the conductor disconnects from the conference for any reason, the conference reverts to non-conducted mode until another node issues a request to become conductor. + +**Table 7-41 – GCC-Conductor-Assign – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|--------------------|---------|------------|---------| +| Conference ID | M | M | M(=RQ) | +| Requesting Node ID | | M | | +| Result | | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Requesting Node ID*: The Node ID of the requesting node. + +*Result*: An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, non-conductible conference, token already owned. + +![Sequence diagram for GCC-Conductor-Assign. A Node Controller sends a 'GCC-Conductor-Assign request' to a GCC Provider. This GCC Provider communicates via a dashed line to another GCC Provider. The second GCC Provider sends a 'GCC-Conductor-Assign indication' to 'All Nodes Node Controller and All Application Protocol Entities'. Finally, the first GCC Provider sends a 'GCC-Conductor-Assign confirm' back to the original Node Controller.](6116b1a533010c170fc526ec513ba0b8_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant GP1 as GCC Provider + participant GP2 as GCC Provider + participant AN as All Nodes +Node Controller +and All Application +Protocol Entities + + NC->>GP1: GCC-Conductor-Assign request + GP1-->GP2: + GP2->>AN: GCC-Conductor-Assign indication + GP1->>NC: GCC-Conductor-Assign confirm + +``` + +T.124(01-07)\_F7-30 + +Sequence diagram for GCC-Conductor-Assign. A Node Controller sends a 'GCC-Conductor-Assign request' to a GCC Provider. This GCC Provider communicates via a dashed line to another GCC Provider. The second GCC Provider sends a 'GCC-Conductor-Assign indication' to 'All Nodes Node Controller and All Application Protocol Entities'. Finally, the first GCC Provider sends a 'GCC-Conductor-Assign confirm' back to the original Node Controller. + +**Figure 7-30 – GCC-Conductor-Assign – Sequence of primitives** + +#### 7.5.1.2 GCC-Conductor-Release + +In order to change its status from conductor to normal participant, the Node Controller at the conductor node issues the GCC-Conductor-Release request primitive. As soon as the conductor has requested the release of conductorship, all Node Controllers in the conference as well as all enrolled Application Protocol Entities at all nodes in the conference are informed of the change in operational mode by means of the GCC-Conductor-Release indication. The order of GCC-Conductor-Assign and GCC-Conductor-Release indications represents the actual order of conductorship transitions. Any participant issuing a GCC-Conductor-Release, but not being the current conductor, shall be answered by GCC with a GCC-Conductor-Release confirmation containing a negative result and reason description. In this situation, no indications shall be sent to the other participants. Apart from this user-initiated transition to non-conducted mode, the release of conductorship can also be initiated by GCC itself, for instance because the conductor disconnected from the conference. The indication form of this primitive may also be issued to an Application Protocol Entity upon enrolling into a conference to inform it that the conference is in non-conducted mode. Table 7-42 shows the parameters and types of this primitive. The sequences of primitives belonging to both situations are depicted in Figures 7-31 and 7-32, respectively. + +**Table 7-42 – GCC-Conductor-Release – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|---------------|---------|------------|---------| +| Conference ID | M | M | M(=RQ) | +| Result | | | M | + +*Conference ID:* Identifier of the conference to which the primitive refers. + +*Accept/Reject:* This flag indicates whether the GCC-Conductor-Release request was accepted or rejected. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, did not own token. + +![Sequence diagram showing the GCC-Conductor-Release process. A Node Controller sends a GCC-Conductor-Release request to a GCC Provider. The GCC Provider then sends a GCC-Conductor-Release indication to All Nodes (Node Controller and All Application Protocol Entities). Finally, the GCC Provider sends a GCC-Conductor-Release confirm back to the Node Controller.](2fbb410da68e626ba5e994d872031f14_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant GP1 as GCC Provider + participant GP2 as GCC Provider + participant AN as All Nodes +Node Controller +and All Application +Protocol Entities + + NC->>GP1: GCC-Conductor-Release request + GP1-->>GP2: + GP2->>AN: GCC-Conductor-Release indication + GP1-->>NC: GCC-Conductor-Release confirm + +``` + +T.124(01-07)\_F7-31 + +Sequence diagram showing the GCC-Conductor-Release process. A Node Controller sends a GCC-Conductor-Release request to a GCC Provider. The GCC Provider then sends a GCC-Conductor-Release indication to All Nodes (Node Controller and All Application Protocol Entities). Finally, the GCC Provider sends a GCC-Conductor-Release confirm back to the Node Controller. + +**Figure 7-31 – GCC-Conductor-Release (user-initiated) – Sequence of primitives** + +![Sequence diagram showing GCC-Provider sending GCC-Conductor-Release indication to All Nodes Node Controller and All Application Protocol Entities.](7b7596fb5ef925025341a9aacb6f2be7_img.jpg) + +``` + +sequenceDiagram + participant GCCProvider as GCC Provider + participant AllNodes as All Nodes +Node Controller +and All Application +Protocol Entities + GCCProvider->>AllNodes: GCC-Conductor-Release indication + +``` + +T.124(01-07)\_F7-32 + +Sequence diagram showing GCC-Provider sending GCC-Conductor-Release indication to All Nodes Node Controller and All Application Protocol Entities. + +**Figure 7-32 – GCC-Conductor-Release (GCC-initiated) – Sequence of primitives** + +#### 7.5.1.3 GCC-Conductor-Please + +The primitive GCC-Conductor-Please request may be issued by a Node Controller at a Conventional node to ask the current conductor to give conductorship to the requesting node. The GCC-Conductor-Please indication is forwarded to the current conducting node. The current conductor may then choose to give conductorship to the requester by using the GCC-Conductor-Give primitive. The confirm portion of this primitive is only local confirmation that the request was accepted by the local GCC Provider. No confirmation from the conductor is given directly. Table 7-43 shows the parameters and types of this primitive. Figure 7-33 shows the sequence of events when using this primitive. + +**Table 7-43 – GCC-Conductor-Please – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|--------------------|---------|------------|---------| +| Conference ID | M | M | M(=RQ) | +| Requesting Node ID | | M | | +| Result | | | M | + +*Conference ID:* Identifier of the conference to which the primitive refers. + +*Requesting Node ID:* The Node ID of the requesting node. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, not in conducted mode. + +![Sequence diagram showing the GCC-Conductor-Please sequence of primitives between a Node Controller, two GCC Providers, and a Conducting Node Node Controller.](7ec36a0a9788e1cb33df5372695498c8_img.jpg) + +``` + +sequenceDiagram + participant NC1 as Node Controller + participant GP1 as GCC Provider + participant GP2 as GCC Provider + participant CNodeNC as Conducting Node Node Controller + + NC1->>GP1: GCC-Conductor-Please request + GP1-->>GP2: + GP2->>CNodeNC: GCC-Conductor-Please indication + CNodeNC-->>GP1: + GP1-->>NC1: GCC-Conductor-Please confirm + +``` + +T.124(01-07)\_F7-33 + +Sequence diagram showing the GCC-Conductor-Please sequence of primitives between a Node Controller, two GCC Providers, and a Conducting Node Node Controller. + +**Figure 7-33 – GCC-Conductor-Please – Sequence of primitives** + +NOTE – It is possible to use this primitive (in conjunction with others) to ensure that a particular node becomes the conference conductor with no opportunity for another node to acquire conductorship. The procedure would be for the conference convener first to create a conference which is locked and to then acquire conductorship using the GCC-Conductor-Assign primitive. Once the convener has become the conference conductor, it may then allow other nodes into the conference either by unlocking it using GCC-Conference-Unlock and/or by adding the other nodes directly. Once the intended conducting node has joined the conference, conductorship may be passed directly to that node by use of the GCC-Conductor-Give primitive. + +#### 7.5.1.4 GCC-Conductor-Give + +The primitive GCC-Conductor-Give request may be issued by a Node Controller to transfer conductorship to a specific node. If the conductorship is not accepted by the intended recipient, conference conductorship continues to be held by the original conductor. Table 7-44 shows the parameters and types of this primitive. Figure 7-34 shows the sequence of events when using this primitive. + +**Table 7-44 – GCC-Conductor-Give – Types of primitives and their parameters** + +| Parameter | Request | Indication | Response | Confirm | +|-------------------|---------|------------|----------|---------| +| Conference ID | M | M | M(=IN) | M(=RQ) | +| Recipient Node ID | M | | | M(=) | +| Result | | | M | M(=) | + +*Conference ID:* Identifier of the conference to which the primitive refers. + +*Recipient Node ID:* The Node ID of the node to which conductorship is being transferred. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, not conductor, give not accepted. + +![Sequence diagram for GCC-Conductor-Give showing interactions between Conducting Node Node Controller, GCC Provider, Recipient Node Node Controller, and All Nodes Node Controller and All Application Protocol Entities.](ca86f53f9735fe98b6c6003d1b759f64_img.jpg) + +``` + +sequenceDiagram + participant C as Conducting Node Node Controller + participant GP1 as GCC Provider + participant GP2 as GCC Provider + participant R as Recipient Node Node Controller + participant GP3 as GCC Provider + participant A as All Nodes Node Controller and All Application Protocol Entities + + C->>GP1: GCC-Conductor-Give request + GP1-->>GP2: GCC-Conductor-Give indication + GP2->>R: GCC-Conductor-Give indication + R-->>GP2: GCC-Conductor-Give response + GP2-->>GP1: GCC-Conductor-Give confirm + GP3->>A: GCC-Conductor-Assign indication + +``` + +T.124(01-07)\_F7-34 + +Sequence diagram for GCC-Conductor-Give showing interactions between Conducting Node Node Controller, GCC Provider, Recipient Node Node Controller, and All Nodes Node Controller and All Application Protocol Entities. + +**Figure 7-34 – GCC-Conductor-Give – Sequence of primitives** + +#### 7.5.1.5 GCC-Conductor-Inquire + +The primitive GCC-Conductor-Inquire request may be issued at any time by either a Node Controller or Application Protocol Entity in order to find out whether the conference is conducted or not, and if so, which node is the conductor, and if the requesting node has been granted conducted-mode permission. Table 7-45 shows the parameters and types of this primitive. Figure 7-35 shows the sequence of events when using this primitive. + +**Table 7-45 – GCC-Conductor-Inquire – Types of primitives and their parameters** + +| Parameter | Request | Confirm | +|----------------------------------|---------|---------| +| Conference ID | M | M(=) | +| Conducted vs. Non-Conducted Flag | | M | +| Conductor Node ID | | C | +| Permission flag | | C | +| Result | | M | + +*Conference ID:* Identifier of the conference to which the primitive refers. + +*Conducted vs. Non-Conducted Flag:* A flag indicating whether the indicated conference is currently in conducted mode or non-conducted mode. + +*Conductor Node ID:* The Node ID of the node that is currently conductor. Not present if currently in non-conducted mode. + +*Permission Flag:* If in conducted mode, this flag indicates whether or not the local node has been granted conducted-mode permission. + +*Result:* An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference. + +![Sequence diagram showing the GCC-Conductor-Inquire sequence of primitives between a Node Controller or Application Protocol Entity and a GCC Provider. The Node Controller sends a GCC-Conductor-Inquire request to the GCC Provider, and the GCC Provider returns a GCC-Conductor-Inquire confirm to the Node Controller.](2dd10dd89365981b6b6154de6390a602_img.jpg) + +``` + +sequenceDiagram + participant NCAPE as Node Controller or +Application Protocol Entity + participant GCCP as GCC Provider + NCAPE->>GCCP: GCC-Conductor-Inquire +request + GCCP-->>NCAPE: GCC-Conductor-Inquire +confirm + +``` + +T.124(01-07)\_F7-35 + +Sequence diagram showing the GCC-Conductor-Inquire sequence of primitives between a Node Controller or Application Protocol Entity and a GCC Provider. The Node Controller sends a GCC-Conductor-Inquire request to the GCC Provider, and the GCC Provider returns a GCC-Conductor-Inquire confirm to the Node Controller. + +**Figure 7-35 – GCC-Conductor-Inquire – Sequence of primitives** + +#### 7.5.1.6 GCC-Conductor-Permission-Ask + +The primitive GCC-Conductor-Permission-Ask request may be issued by a Node Controller to ask the current conductor to grant (or release) permission to allow Application Protocol Entities at the requesting node to perform any actions for which permission from the conductor is required. The definition of which specific actions require this permission is a matter for the individual Application Protocol specifications to define. The GCC-Conductor-Permission-Ask indication is forwarded to the current conducting node. The order of GCC-Conductor-Permission-Ask indications from a single node represents the actual order of the requests from that node. The current conductor may then choose to grant (or release) conducted-mode permission to the requester by using the GCC-Conductor-Permission-Grant primitive, or to ignore the request. The confirm portion of this primitive is only local confirmation that the request was accepted by the local GCC Provider. No confirmation from the conductor is given directly. Table 7-46 shows the parameters and types of this primitive. Figure 7-36 shows the sequence of events when using this primitive. + +**Table 7-46 – GCC-Conductor-Permission-Ask – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|--------------------|---------|------------|---------| +| Conference ID | M | M | M(=RQ) | +| Grant/Release Flag | M | M(=) | M(=) | +| Requesting Node ID | | M | | +| Result | | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Give/Release Flag*: This flag indicates whether the requester desires to be granted conducted-mode permission, or if the requester desires to release conducted-mode permission. + +*Requesting Node ID*: The Node ID of the requesting node. + +*Result*: An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, not in conducted mode. + +![Sequence diagram showing the GCC-Conductor-Permission-Ask process between a Node Controller, two GCC Providers, and a Conducting Node Node Controller.](b3335932702b8668e62791e9fd12c9ff_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant GP1 as GCC Provider + participant GP2 as GCC Provider + participant CN as Conducting Node Node Controller + + NC->>GP1: GCC-Conductor-Permission-Ask request + GP1-->>GP2: GCC-Conductor-Permission-Ask indication + GP2->>CN: GCC-Conductor-Permission-Ask indication + CN-->>GP1: GCC-Conductor-Permission-Ask confirm + GP1-->>NC: GCC-Conductor-Permission-Ask confirm + +``` + +T.124(01-07)\_F7-36 + +Sequence diagram showing the GCC-Conductor-Permission-Ask process between a Node Controller, two GCC Providers, and a Conducting Node Node Controller. + +**Figure 7-36 – GCC-Conductor-Permission-Ask – Sequence of primitives** + +#### 7.5.1.7 GCC-Conductor-Permission-Grant + +The primitive GCC-Conductor-Permission-Grant request may be issued by a Node Controller of the conducting node to grant or revoke conducted-mode permission from one or more nodes in a conference. The corresponding GCC-Conductor-Permission-Grant indication is broadcast to every node in the conference and indicates which nodes currently have conducted-mode permission, and also which have requested, but are still waiting for permission. The latter list may be given in the order that the conductor believes permission will ultimately be granted. The indication is given to the Node Controller as well as all enrolled Application Protocol Entities at each node. The order of multiple GCC-Conductor-Permission-Grant indications represents the actual order of the requests from the conductor – that is, the most recently received indication applies. Conducted-mode permission is typically given in response to a GCC-Conductor-Permission-Ask, but may also be given unsolicited by the conductor. The conducted node, itself, is assumed to have conducted-mode permission whether or not it is explicitly listed in the list of nodes granted permission. When a conference first becomes conducted it is to be assumed that no nodes have permission – this is true even if the conference had previously been in conducted mode. If the conductorship changes hands via a successful GCC-Conductor-Give operation, the states of permission are left as they were last broadcast by the original conductor. When a new node joins a conference, the node shall assume that it has no permission. In this case, the Node Controller at the conducting node may re-broadcast the permission list by re-issuing a CC-Conductor-Permission-Grant request so that the new node is made aware of the permission status of other nodes in the conference. The confirm portion of this primitive is only local confirmation that the request was accepted by the local GCC Provider. Table 7-47 shows the parameters and types of this primitive. Figure 7-37 shows the sequence of events when using this primitive. + +**Table 7-47 – GCC-Conductor-Permission-Grant – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|--------------------------------------|---------|------------|---------| +| Conference ID | M | M | M(=RQ) | +| List of Nodes Granted Permission | M | M(=) | | +| List of Nodes Waiting for Permission | O | O(=) | | +| Permission Flag | | M | | +| Result | | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*List of Nodes Granted Permission*: A list of Node IDs, one for each node which the conductor has granted conducted-mode permission. If this list is empty, then no nodes have conducted-mode permission. + +*List of Nodes Waiting for Permission*: An ordered list of Node IDs, one for each node which is being considered by the conductor to receive conducted-mode permission, but has not yet received it. The conductor may order the list in the order in which it is expected that permission will be granted. If so, the first item in the list is to be considered the next node likely to receive permission. + +*Permission Flag*: This flag indicates whether or not the local node is present on the list of nodes granted permission. This is primarily to allow Application Protocol Entities to easily determine their mode of operation without requiring them to search through the returned lists. + +*Result*: An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, not conductor. + +![Sequence diagram for GCC-Conductor-Permission-Grant showing message flow between Conducting Node, GCC Providers, and All Nodes.](67c5b121b58d497a6de5addf4e7bd555_img.jpg) + +``` + +sequenceDiagram + participant CN as Conducting Node +Node Controller + participant GP1 as GCC Provider + participant GP2 as GCC Provider + participant AN as All Nodes +Node Controller +and All Application +Protocol Entities + + CN->>GP1: GCC-Conductor-Permission-Grant request + GP1-->>GP2: + GP2->>AN: GCC-Conductor-Permission-Grant indication + AN->>GP2: + GP2-->>GP1: + GP1->>CN: GCC-Conductor-Permission-Grant confirm + +``` + +The diagram illustrates the sequence of primitives for the GCC-Conductor-Permission-Grant process. It involves four entities: the Conducting Node Node Controller, two GCC Providers, and All Nodes Node Controller and All Application Protocol Entities. The process begins with a 'GCC-Conductor-Permission-Grant request' from the Conducting Node Node Controller to the first GCC Provider. This is followed by a 'GCC-Conductor-Permission-Grant indication' being passed through the GCC Providers to All Nodes Node Controller and All Application Protocol Entities. Finally, a 'GCC-Conductor-Permission-Grant confirm' is sent back from All Nodes Node Controller and All Application Protocol Entities through the GCC Providers to the Conducting Node Node Controller. T.124(01-07)\_F7-37 + +Sequence diagram for GCC-Conductor-Permission-Grant showing message flow between Conducting Node, GCC Providers, and All Nodes. + +**Figure 7-37 – GCC-Conductor-Permission-Grant – Sequence of primitives** + +## 7.6 Miscellaneous functions + +### 7.6.1 Description of abstract services + +The following is a list of the primitives defined in this subclause and a brief summary of the function of each: + +- GCC-Conference-Time-Remaining – Allows the Node Controller at the conference convener to notify all nodes that a timed conference is scheduled to end at a particular time. +- GCC-Conference-Time-Inquire – Allows the Node Controller at any node to find out how much time is remaining in a timed conference. +- GCC-Conference-Extend – Allows the Node Controller at any node to request that the convener extend a timed conference beyond its allocated time duration. +- GCC-Conference-Assistance – Used to request some unspecified form of assistance from a conference operator. +- GCC-Text-Message – Used to send an arbitrary text message to a set of other nodes for display to the user or users at those nodes. + +#### 7.6.1.1 GCC-Conference-Time-Remaining + +The GCC-Conference-Time-Remaining request primitive may be used by the Node Controller to announce to all nodes that a certain amount of time is remaining in a timed conference. It may also be issued indicating the time remaining for a specific node, rather than for all nodes. This request is intended to be issued by the Convener, but may be issued by other nodes as well. Typically, this primitive would be issued once, near the end of a timed conference, to indicate that the conference is almost over. Table 7-48 shows the parameters and types of this primitive. Figure 7-38 shows the sequence of events when using this primitive. + +**Table 7-48 – GCC-Conference-Time-Remaining – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|----------------|---------|------------|---------| +| Conference ID | M | M | M(=RQ) | +| Time Remaining | M | M(=) | | +| Node ID | O | O(=) | | +| Source Node ID | | M | | +| Result | | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Time Remaining*: Indication of time remaining in conference in one-second increments. + +*Node ID*: Optional parameter which, if present, indicates that the indicated time-remaining only applies to the specific node listed. If not included, the time-remaining applies to all nodes in the conferences. + +*Source Node ID*: Node ID of the node which issued the request. + +*Result*: An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference. + +![Sequence diagram showing the GCC-Conference-Time-Remaining primitive flow between Convener Node Controller, GCC Providers, and All Nodes Node Controller.](985267cff5b5d65ce5c180ff2ef37118_img.jpg) + +``` + +sequenceDiagram + participant Convener as Convener Node Controller + participant GP1 as GCC Provider + participant GP2 as GCC Provider + participant AllNodes as All Nodes Node Controller + + Convener->>GP1: GCC-Conference-Time-Remaining request + GP1-->>GP2: GCC-Conference-Time-Remaining indication + GP2->>AllNodes: GCC-Conference-Time-Remaining indication + AllNodes-->>Convener: GCC-Conference-Time-Remaining confirm + +``` + +The diagram illustrates the sequence of events for the GCC-Conference-Time-Remaining primitive. It involves four entities: Convener Node Controller, two GCC Providers, and All Nodes Node Controller. The sequence is as follows: 1. The Convener Node Controller sends a 'GCC-Conference-Time-Remaining request' to the first GCC Provider. 2. The first GCC Provider sends a 'GCC-Conference-Time-Remaining indication' to the second GCC Provider. 3. The second GCC Provider sends a 'GCC-Conference-Time-Remaining indication' to the All Nodes Node Controller. 4. The All Nodes Node Controller sends a 'GCC-Conference-Time-Remaining confirm' back to the Convener Node Controller. + +T.124(01-07)\_F7-38 + +Sequence diagram showing the GCC-Conference-Time-Remaining primitive flow between Convener Node Controller, GCC Providers, and All Nodes Node Controller. + +**Figure 7-38 – GCC-Conference-Time-Remaining – Sequence of primitives** + +#### 7.6.1.2 GCC-Conference-Time-Inquire + +The GCC-Conference-Time-Inquire request primitive may be used by any node to find out from the Convener how much time is remaining in the conference. Receipt of the indication form of this primitive by the Convener (if the Convener supports this primitive) results in the time remaining to be broadcast to all nodes in the conference using the GCC-Conference-Time-Remaining primitive. + +Table 7-49 shows the parameters and types of this primitive. Figure 7-39 shows the sequence of events when using this primitive. + +**Table 7-49 – GCC-Conference-Time-Inquire – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|---------------------------------------------|---------|------------|---------| +| Conference ID | M | M | M(=RQ) | +| Conference-Wide vs. Node-Specific Time Flag | M | M(=) | | +| Requesting Node ID | | M | | +| Result | | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Conference-Wide vs. Node-Specific Time Flag*: This flag indicates if the request is to find out the time remaining for the entire conference, or, if different, the time remaining for the requesting node. If the Convener only considers a single conference-wide end time, it may ignore this flag. + +*Requesting Node ID*: Node ID of the requesting node. + +*Result*: An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference. + +![Sequence diagram for GCC-Conference-Time-Inquire showing the flow between Node Controller, GCC Provider, and Convener Node Controller.](e35f25e0b66752d4179a4cb108a3fb5a_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant GP1 as GCC Provider + participant GP2 as GCC Provider + participant CN as Convener Node Controller + + NC->>GP1: GCC-Conference-Time-Inquire request + GP1-->>GP2: + GP2->>CN: GCC-Conference-Time-Inquire indication + CN-->>GP2: + GP2-->>NC: GCC-Conference-Time-Inquire confirm + +``` + +The diagram illustrates the sequence of events for the GCC-Conference-Time-Inquire primitive. It involves four entities: Node Controller, GCC Provider (two instances), and Convener Node Controller. The sequence is as follows: 1. The Node Controller sends a 'GCC-Conference-Time-Inquire request' to the first GCC Provider. 2. A dashed arrow indicates a connection or data flow between the two GCC Provider entities. 3. The second GCC Provider sends a 'GCC-Conference-Time-Inquire indication' to the Convener Node Controller. 4. The Convener Node Controller sends a return message (indicated by a dashed arrow) to the second GCC Provider. 5. Finally, the second GCC Provider sends a 'GCC-Conference-Time-Inquire confirm' message back to the Node Controller. + +Sequence diagram for GCC-Conference-Time-Inquire showing the flow between Node Controller, GCC Provider, and Convener Node Controller. + +T.124(01-07)\_F7-39 + +**Figure 7-39 – GCC-Conference-Time-Inquire – Sequence of primitives** + +#### 7.6.1.3 GCC-Conference-Extend + +The GCC-Conference-Extend request primitive may be used by the Node Controller at a node to request from the Convener that more time be added to a timed conference. Receipt of the indication form of this primitive by the Convener (if the Convener supports this primitive) results in a broadcast of the new time remaining in the conference to all nodes using the GCC-Conference-Time-Remaining primitive (even if the time was not actually extended). There is no requirement that the actual amount of time the convener adds to the time-remaining equal the requested time. Table 7-50 shows the parameters and types of this primitive. Figure 7-40 shows the sequence of events when using this primitive. + +**Table 7-50 – GCC-Conference-Extend – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|---------------------------------------------|---------|------------|---------| +| Conference ID | M | M | M(=RQ) | +| Time Requested | M | M(=) | M(=) | +| Conference-Wide vs. Node-Specific Time Flag | M | M(=) | | +| Requesting Node ID | | M | | +| Result | | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Time Requested*: In the request and indication, this parameter indicates the desired amount of time to extend the conference in one-second increments. + +*Conference-Wide vs. Node-Specific Time Flag*: This flag indicates if the request is to extend the time remaining for the entire conference, or the time remaining for the requesting node. If the Convener only considers a single conference-wide end time, it may ignore this flag. + +*Requesting Node ID*: Node ID of the requesting node. + +*Result*: An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference, not conductor. + +![Sequence diagram for GCC-Conference-Extend showing interactions between Node Controller, GCC Provider, and Convener Node Controller.](ca5555bb37f54857199d243feff8479e_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant GP1 as GCC Provider + participant GP2 as GCC Provider + participant CN as Convener Node Controller + + NC->>GP1: GCC-Conference-Extend request + GP1-->>GP2: + GP2->>CN: GCC-Conference-Extend indication + CN-->>GP1: + GP1-->>NC: GCC-Conference-Extend confirm + +``` + +The diagram illustrates the sequence of primitives for the GCC-Conference-Extend operation. It involves four entities: Node Controller, GCC Provider (two instances), and Convener Node Controller. The sequence is as follows: 1. The Node Controller sends a 'GCC-Conference-Extend request' to the first GCC Provider. 2. A dashed arrow indicates a connection or data flow between the two GCC Provider instances. 3. The second GCC Provider sends a 'GCC-Conference-Extend indication' to the Convener Node Controller. 4. The Convener Node Controller sends a response back to the second GCC Provider. 5. Finally, the first GCC Provider sends a 'GCC-Conference-Extend confirm' message back to the Node Controller. + +Sequence diagram for GCC-Conference-Extend showing interactions between Node Controller, GCC Provider, and Convener Node Controller. + +T.124(01-07)\_F7-40 + +**Figure 7-40 – GCC-Conference-Extend – Sequence of primitives** + +#### 7.6.1.4 GCC-Conference-Assistance + +The GCC-Conference-Assistance primitive provides a simple means to request some form of assistance from a conference operator. Issuing a GCC-Conference-Assistance request results in a GCC-Conference-Assistance indication to be broadcast to the Node Controller at all nodes in the specified conference which support this primitive. The intended response to this primitive is unspecified and outside the scope of this Recommendation. Table 7-51 shows the parameters and types of this primitive. Figure 7-41 shows the sequence of events when using this primitive. + +**Table 7-51 – GCC-Conference-Assistance – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|----------------|---------|------------|---------| +| Conference ID | M | M | M(=RQ) | +| User Data | O | O(=) | | +| Source Node ID | | M | | +| Result | | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*User Data*: Unspecified user data. + +*Source Node ID*: The Node ID of the source of the assistance request. + +*Result*: An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference. + +![Sequence diagram for GCC-Conference-Assistance showing the flow between Node Controller, GCC Provider, and All Nodes Node Controller.](5a01395925fc88802da68fb5ac0f31ff_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant GP1 as GCC Provider + participant GP2 as GCC Provider + participant ANNC as All Nodes Node Controller + + NC->>GP1: GCC-Conference-Assistance request + GP1-->>GP2: GCC-Conference-Assistance indication + GP2->>ANNC: GCC-Conference-Assistance indication + ANNC-->>NC: GCC-Conference-Assistance confirm + +``` + +The diagram illustrates the sequence of primitives for GCC-Conference-Assistance. It involves four entities: Node Controller, GCC Provider, GCC Provider, and All Nodes Node Controller. The sequence is as follows: 1. Node Controller sends a 'GCC-Conference-Assistance request' to the first GCC Provider. 2. The first GCC Provider sends a 'GCC-Conference-Assistance indication' to the second GCC Provider. 3. The second GCC Provider sends a 'GCC-Conference-Assistance indication' to the All Nodes Node Controller. 4. The All Nodes Node Controller sends a 'GCC-Conference-Assistance confirm' back to the Node Controller. + +Sequence diagram for GCC-Conference-Assistance showing the flow between Node Controller, GCC Provider, and All Nodes Node Controller. + +T.124(01-07)\_F7-41 + +**Figure 7-41 – GCC-Conference-Assistance – Sequence of primitives** + +#### 7.6.1.5 GCC-Text-Message + +The GCC-Text-Message primitive provides a simple means to communicate unspecified text messages. Issuing a GCC-Text-Message request results in a GCC-Text-Message indication to be either broadcast to the Node Controller at all nodes in the specified conference which support this primitive, or to be sent to a single node. The intended response to this primitive is to display the text message to the conference participants by some means unspecified by this Recommendation. Table 7-52 shows the parameters and types of this primitive. Figure 7-42 shows the sequence of events when using this primitive. + +**Table 7-52 – GCC-Text-Message – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|---------------------|---------|------------|---------| +| Conference ID | M | M | M(=RQ) | +| Text Message | M | M(=) | | +| Destination Node ID | O | | | +| Source Node ID | | M | | +| Result | | | M | + +*Conference ID*: Identifier of the conference to which the primitive refers. + +*Text Message*: Unicode text message. + +*Destination Node ID*: The Node ID of a single node to receive the text message. If no node is specified, the message is broadcast to all nodes in the specified conference. + +*Source Node ID*: The Node ID of the source of the text message. + +*Result*: An indication of whether the request was accepted or rejected, and if rejected, the reason why. It contains one of a list of possible results: successful, invalid conference. + +![Sequence diagram showing the GCC-Text-Message sequence of primitives between a Node Controller, two GCC Providers, and Destination Nodes.](a0eb8d30ac11ba97b2733c187b89ff22_img.jpg) + +``` +sequenceDiagram + participant NC as Node Controller + participant GP1 as GCC Provider + participant GP2 as GCC Provider + participant DN as Destination Nodes Node Controller + + NC->>GP1: GCC-Text-Message request + GP1-->>GP2: GCC-Text-Message indication + GP2->>DN: GCC-Text-Message indication + DN-->>GP1: GCC-Text-Message confirm + GP1-->>NC: GCC-Text-Message confirm +``` + +The diagram illustrates the sequence of primitives for a GCC-Text-Message. It involves four entities: a Node Controller, two GCC Providers, and Destination Nodes (represented by a Node Controller). The sequence is as follows: 1. The Node Controller sends a 'GCC-Text-Message request' to the first GCC Provider. 2. The first GCC Provider sends a 'GCC-Text-Message indication' to the second GCC Provider. 3. The second GCC Provider sends a 'GCC-Text-Message indication' to the Destination Nodes. 4. The Destination Nodes send a 'GCC-Text-Message confirm' back to the second GCC Provider. 5. The second GCC Provider sends a 'GCC-Text-Message confirm' back to the first GCC Provider. 6. The first GCC Provider sends a 'GCC-Text-Message confirm' back to the Node Controller. + +Sequence diagram showing the GCC-Text-Message sequence of primitives between a Node Controller, two GCC Providers, and Destination Nodes. + +**Figure 7-42 – GCC-Text-Message – Sequence of primitives** + +# 8 GCC Protocol Specification + +## 8.1 General operation + +A GCC Provider in any node is the MCS Control application, communicating with MCS via the Control MCSAP. On initialization, the GCC Provider shall establish its communication link with MCS through a Control MCSAP through local means. + +In all cases, a Conference is established by creating an MCS Domain. A Conference has a one-to-one correspondence with a single MCS Domain. The actual creation of an MCS domain is done through local means. Conferences are created or joined by use of the MCS-Connect-Provider primitives. + +For all request primitives which refer to a particular conference (via the Conference ID), the local GCC Provider to which the primitive is issued shall determine if the specified conference is one to which the node is currently joined. If so, the GCC Provider proceeds as described below for each primitive. If not, the request is rejected and the corresponding confirm primitive is issued specifying invalid-conference as the reason for rejection. Any response primitive issued which refers to an invalid conference is ignored by the GCC Provider (or the error is handled by some unspecified local means). + +GCC Providers communicate with each other via GCC Protocol Data Units (GCCPDUs). The GCCPDUs are transmitted either via the two MCS data service primitives (MCS-Send-Data or MCS-Uniform-Send-Data; see Table 9-4) or via MCS-Connect-Provider primitives for GCCPDUs used during connection set-up. + +All GCCPDUs are categorized into either request, response, or indication classes. Request PDUs are defined to be those that require a corresponding response PDU in return. Indication PDUs are those that do not require a response (or in some cases, where the response is provided indirectly). For request PDUs which do not correspond to mandatory functionality, a generic response PDU is provided (FunctionNotSupportedResponse), which allows the GCC Provider receiving a request to + +respond to the requesting node without needing to have knowledge of the format of the specific response PDU. To allow the requester to know what this PDU is in response to, the entire request PDU is included within the FunctionNotSupportedResponse PDU. The FunctionNotSupportedResponse PDU shall be sent at the same priority level as that of the received request PDU. + +NOTE – This terminology (request, response, and indication) does not have a one-to-one correspondence to the definition of request, indication, response, and confirm used in the definition of the primitives. The terminology has been chosen to relate to the primary purpose of the PDU types with respect to the functions that they will perform. For this reason, the term confirm was not needed to describe PDUs – response PDUs are those which are sourced from a response primitive and result in a confirm primitive. + +The GCC protocol includes support for non-standard extensions. On receipt of a nonStandardRequest PDU, a GCC Provider which does not understand the request, shall issue a FunctionNotSupportedResponse PDU in return. nonStandardResponse and nonStandardIndication PDUs may be ignored by a GCC Provider. + +## 8.2 Conference establishment and termination + +### 8.2.1 Conference creation + +On receipt of the primitive GCC-Conference-Create request, a GCC Provider shall issue an MCS-Connect-Provider request primitive with the parameters shown in Table 8-1. The local GCC Provider shall allocate the Conference ID, which shall be used as the local MCS Domain Selector associated with the created conference. The Conference ID is included as the Calling Domain Selector. It is also maintained by the local GCC Provider as the means identifying this conference in future primitives. + +If the combination of the Conference Name and Conference Name Modifier parameters are identical to those of a conference to which the local node is already joined (either the numerical or text forms of the name), the request is instead immediately rejected by issuing a GCC-Conference-Create response with conference-name-already-exists as the result. Otherwise, the GCC Provider shall retain the Conference Name and Conference Name Modifier (in addition to including the Conference Name in the ConferenceCreateRequest PDU) to be used in the procedures for responding to a conference query, conference join, or in initiating a conference invite. + +**Table 8-1 – MCS-Connect-Provider request parameters for ConferenceCreateRequest PDU** + +| Parameter | Contents | +|-------------------------|------------------------------------------------| +| Calling Address | From request primitive | +| Calling Domain Selector | Conference ID as chosen by the GCC Provider | +| Called Address | From request primitive | +| Called Domain Selector | NULL | +| Upward/Downward Flag | Up | +| Domain Parameters | From request primitive | +| Quality of Service | From request primitive | +| User Data | T.124 Object Identifier | +| | ConferenceCreateRequest PDU
(see Table 8-2) | + +The User Data parameter of the MCS-Connect-Provider request contains a structure which includes an Object Identifier identifying the contained PDU as adhering to this Recommendation followed by the PDU itself. The details of this structure are defined in 9.6. The contents of this PDU are shown in Table 8-2. + +**Table 8-2 – ConferenceCreateRequest GCCPDU** + +| Content | Source | Sink | +|---------------------------------------------------------|---------|-----------------------------------------| +| Conference Name | Request | Indication and Destination GCC Provider | +| Convener Password (optional) | Request | Indication | +| Password (optional) | Request | Indication | +| Locked Conference Flag | Request | Indication and Destination GCC Provider | +| Listed Conference Flag | Request | Indication and Destination GCC Provider | +| Conductible Conference Flag | Request | Indication and Destination GCC Provider | +| Termination Method | Request | Indication and Destination GCC Provider | +| Conductor Privilege List (optional) | Request | Indication and Destination GCC Provider | +| Conducted-Mode Conference Privilege List (optional) | Request | Indication and Destination GCC Provider | +| Non-Conducted-Mode Conference Privilege List (optional) | Request | Indication and Destination GCC Provider | +| Conference Description (optional) | Request | Indication and Destination GCC Provider | +| Caller Identifier (optional) | Request | Indication | +| Conference Mode (optional) | Request | Indication | +| User Data (optional) | Request | Indication | + +On receipt of the MCS-Connect-Provider indication that includes a T.124 Object Identifier and the ConferenceCreateRequest PDU, a GCC Provider shall generate a GCC-Conference-Create indication primitive with the parameters as specified in the included ConferenceCreateRequest PDU. It shall issue this primitive to the Control GCCSAP. The GCC Provider shall also allocate a Conference ID, a locally unique string, which shall also be included in this primitive. If the conference is successfully created, the GCC Provider shall use this Conference ID as the means of identifying this conference in future primitives. If GCC does not have the resources necessary to create a new conference, it may generate the negative response automatically without generating the GCC-Conference-Create indication. Otherwise, on receipt of a successful GCC-Conference-Create response from the Control GCCSAP, the GCC Provider (now the Top GCC Provider for this conference) shall issue an MCS-Attach-User request. On receipt of the MCS-Attach-User confirm which contains the allocated Node ID, the GCC Provider shall then join the corresponding Node ID Channel by issuing an MCS-Channel-Join request. The GCC Provider shall also join the appropriate GCC Broadcast Channel(s) by issuing one or two MCS-Channel-Join requests (successive such requests may be issued prior to receiving the previous confirm). It may be necessary, prior to attaching, to locally indicate to the MCS Provider that a new domain has been created. Any exchange necessary to do this is considered a local matter not covered by this Recommendation. + +There are three different GCC Broadcast Channels, each of which broadcasts similar, but different, sets of information. Earlier versions of GCC used a single broadcast channel known as the GCC-Broadcast-Channel. On this channel, older Conventional nodes that existed prior to the introduction of Node Categories receive GCC control messages and Full Roster Refreshes. To support all possible GCC nodes that may participate in a conference, it is imperative that nodes continue to support the original GCC-Broadcast-Channel even though no nodes may be joined to it (an exception to this may be Terminal Nodes which are Anonymous). A second GCC Broadcast + +Channel, known as the GCC-Conventional-Broadcast-Channel, is used by nodes that are Node Category-aware. All GCC control PDUs and Roster delta updates that are generated when Conventional Nodes join, leave, or change a roster record are broadcasted on this channel. All nodes (except for older protocol nodes) must join this broadcast channel. Anonymous nodes may ignore the roster deltas received on this channel, but they must process the control messages received. The last GCC Broadcast Channel is known as the GCC-Counted-Broadcast-Channel. On this channel, the Top Provider broadcasts Roster delta updates which are generated when Counted Nodes join, leave, or change a roster record. Only Conventional Nodes join this GCC Broadcast Channel which reduces the amount of network traffic incurred when a large number of Counted Nodes are participating in a conference. + +If the GCC-Conference-Create response includes a Conference Name Modifier parameter, the GCC Provider (now the Top GCC Provider) shall retain this name modifier for later use in handling the conference query, conference join, and conference invite procedures. + +The GCC Provider shall generate an MCS-Connect-Provider response which includes a result which is either success, or user-rejected depending on whether or not the Result parameter in the GCC-Conference-Create response primitive indicated success or failure. The User Data parameter includes the T.124 Object Identifier as well as the ConferenceCreateResponse PDU. The contents of the connect provider primitive are shown in Table 8-3. In the case of successful conference creation, the GCC Provider at the node receiving the MCS-Connect-Provider indication shall become the Top GCC Provider for the conference. + +**Table 8-3 – MCS-Connect-Provider response parameters for ConferenceCreateResponse PDU** + +| Parameter | Contents | +|--------------------|----------------------------------------------| +| Domain Parameters | From response primitive | +| Quality of Service | From response primitive | +| Result | As specified in [ITU-T T.122] | +| User Data | T.124 Object Identifier | +| | ConferenceCreateResponse PDU (see Table 8-4) | + +The ConferenceCreateResponse PDU is shown in Table 8-4. The Node ID parameter, which is the User ID assigned by MCS in response to the MCS-Attach-User request issued by the GCC Provider, shall be supplied by the GCC Provider sourcing this PDU. The Tag parameter is assigned by the source GCC Provider to be locally unique. It is used to identify the returned UserIDIndication PDU. The Result parameter includes GCC-specific failure information sourced directly from the Result parameter in the GCC-Conference-Create response primitive. If the Result parameter is anything except successful, the Result parameter in the MCS-Connect-Provider response is set to user-rejected. + +**Table 8-4 – ConferenceCreateResponse GCCPDU** + +| Content | Source | Sink | +|----------------------|------------------|--------------------------| +| Node ID | Top GCC Provider | Destination GCC Provider | +| Tag | Top GCC Provider | Destination GCC Provider | +| Result | Response | Confirm | +| User Data (optional) | Response | Confirm | + +On receipt of the ConferenceCreateResponse PDU, if the PDU indicated a successful result, a GCC Provider shall first issue an MCS-Attach-User request. On receipt of the MCS-Attach-User confirm which contains the allocated Node ID, the GCC Provider shall then join the Node ID Channel by issuing an MCS-Channel-Join request. The GCC Provider shall also join the GCC-Conventional-Broadcast-Channel and the GCC-Counted-Broadcast-Channel by issuing two MCS-Channel-Join requests (Convener nodes are always considered to be Conventional; see explanation of Broadcast Channels above). The GCC Provider may also join the GCC-Convener-Channel (if it supports any of the functions which require use of this channel) by issuing an MCS-Channel-Join request. Once the GCC Provider has received an MCS-Channel-Join confirm from each of the channel join requests (successive requests may be issued prior to receiving the previous confirm), it shall send a UserIDIndication PDU to the Top GCC Provider by issuing an MCS-Send-Data request specifying as the Channel ID the Node ID of the Top GCC Provider as contained in the received ConferenceCreateResponse PDU, specifying Top data priority, and including the PDU in the Data field. The content of the UserIDIndication PDU is shown in Table 8-5. The Tag parameter is filled in with the value of the corresponding parameter received in the ConferenceCreateResponse PDU. + +**Table 8-5 – UserIDIndication GCCPDU** + +| Content | Source | Sink | +|---------|---------------------|--------------------------| +| Tag | Source GCC Provider | Destination GCC Provider | + +The GCC Provider shall then generate a GCC-Conference-Create confirm primitive and issue it to the Control GCCSAP. This primitive shall include the Conference Name from the original request primitive, the Modified Conference Name (if any) and Result parameters from the received PDU, as well as the locally-allocated Conference ID. If the received PDU had indicated an unsuccessful result, or if the GCC Provider receives an MCS-Disconnect-Provider indication for this connection prior to having issued a successful GCC-Conference-Create confirm, the GCC-Conference-Create confirm primitive is issued immediately, indicating an unsuccessful result, without issuing the attach-user or channel-join requests, and without sending the UserIDIndication PDU. The Result parameter in the PDU as well as the Result parameter reported in the MCS-Connect-Provider confirm (or the Reason parameter of the MCS-Disconnect-Provider) is used to generate the result reported in the GCC-Conference-Create confirm primitive. If the Result parameter of the MCS-Connect-Provider confirm is user-rejected, the Result parameter in the PDU is used to determine the reported result. Otherwise, the Result parameter in the MCS-Connect-Provider is used directly. + +On receipt of a UserIDIndication, the node at which the conference was created shall compare the Tag parameter to its list of outstanding Tags. If the Tag matches one of these, it shall save the User ID of the source node (extracted from the MCS-Send-Data indication) in its database of Node IDs of nodes which are directly below it in the connection hierarchy. If the Tag does not match any outstanding Tags, the PDU shall be ignored. + +If the newly-created Top GCC Provider for this conference receives an MCS-Disconnect-Provider indication for the connection being established at any time during the process of creating the conference (this includes the time that the GCC-Conference-Create indication has been issued to the Control GCCSAP until the time that the UserIDIndication has been received), it shall issue a GCC-Conference-Terminate indication to the Control GCCSAP indicating the requested normal termination as the reason if user-initiated was the reason provided in the MCS-Disconnect-Provider indication, and error termination otherwise. It shall then stop further processing for this connection establishment procedure. If the MCS-Disconnect-Provider indication was received prior to issuing the GCC-Conference-Create indication to the Control GCCSAP, the GCC Provider shall stop further processing for this connection establishment procedure and take no further action. + +The sequence of events for successful conference creation is shown in Figure 8-1. + +NOTE – If a conference is created by local initiation rather than through a request from another node, the GCC Provider at that node shall perform the sequence of events performed by the Top GCC Provider shown in the figure beginning from the MCS-Attach-User request. That is, it shall attach to MCS by issuing an MCS-Attach-User request and wait for the confirm, then it shall join its Node ID channel, and the appropriate GCC Broadcast Channels. It may optionally join the GCC-Convener-Channel since this node is also the Convener in this case. In this case, if another node joins the conference at a later time indicating itself to be the convener (having issued the correct Convener Password), the Top GCC Provider may choose to accept the connection, relinquishing convener privileges to the new node. Note also that it is assumed that in this case, MCS Domain Parameters are set at the time of creation rather than at the time the first connection is established. + +![Sequence diagram showing the process of creating a conference between Node Controller, GCC Provider, and MCS Provider.](c7111699f84f3e2bc4016b7876f10de6_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant GP as GCC Provider + participant MP as MCS Provider + participant MCP as MCS Provider + participant TGP as Top GCC Provider + participant NCC as Node Controller + + NC->>GP: GCC-Conference-Create request + GP->>MP: MCS-Connect-Provider request + MP-->>MCP: ConferenceCreateRequest + MCP->>TGP: MCS-Connect-Provider indication + TGP->>NCC: GCC-Conference-Create indication + NCC-->>TGP: GCC-Conference-Create response + TGP->>MCP: MCS-Attach-User request + MCP-->>TGP: MCS-Attach-User confirm + MCP->>MCP: MCS-Channel-Join request (Node ID Channel) + MCP-->>MCP: MCS-Channel-Join confirm + MCP->>MCP: MCS-Channel-Join request (GCC-Broadcast-Channel) + MCP-->>MCP: MCS-Channel-Join confirm + MCP->>MCP: MCS-Connect-Provider response + MCP-->>MP: ConferenceCreateResponse + MP-->>GP: MCS-Connect-Provider confirm + GP->>MP: MCS-Attach-User request + MP-->>GP: MCS-Attach-User confirm + GP->>MP: MCS-Channel-Join request (Node ID Channel) + MP-->>GP: MCS-Channel-Join confirm + GP->>MP: MCS-Channel-Join request (GCC-Broadcast-Channel) + MP-->>GP: MCS-Channel-Join confirm + GP->>MP: MCS-Channel-Join request (GCC-Convener-Channel) + MP-->>GP: (Optional) MCS-Channel-Join confirm + GP->>MP: MCS-Send-Data request + MP-->>NC: GCC-Conference-Create confirm + MP->>MCP: UserIDIndication + MCP->>TGP: MCS-Send-Data indication + +``` + +The diagram illustrates the sequence of messages for creating a conference. It involves five entities: Node Controller, GCC Provider, MCS Provider, MCS Provider (repeated), and Top GCC Provider. The process begins with a 'GCC-Conference-Create request' from the Node Controller to the GCC Provider, followed by an 'MCS-Connect-Provider request' to the MCS Provider. The MCS Provider then sends a 'ConferenceCreateRequest' to the MCS Provider (repeated). This is followed by an 'MCS-Connect-Provider indication' to the Top GCC Provider, which then sends a 'GCC-Conference-Create indication' to the Node Controller. The Node Controller responds with a 'GCC-Conference-Create response' to the Top GCC Provider. The Top GCC Provider then sends an 'MCS-Attach-User request' to the MCS Provider (repeated), which responds with an 'MCS-Attach-User confirm'. The MCS Provider (repeated) then sends 'MCS-Channel-Join request' messages for the 'Node ID Channel', 'GCC-Broadcast-Channel', and 'GCC-Convener-Channel', each followed by a corresponding 'confirm' message. Finally, the MCS Provider (repeated) sends an 'MCS-Connect-Provider response' to the MCS Provider (repeated), which then sends a 'ConferenceCreateResponse' to the MCS Provider. The MCS Provider then sends an 'MCS-Connect-Provider confirm' to the GCC Provider. The GCC Provider then sends 'MCS-Attach-User request' and 'MCS-Channel-Join request' messages to the MCS Provider, each followed by a 'confirm' message. The GCC Provider also sends an 'MCS-Send-Data request' to the MCS Provider. The MCS Provider then sends a 'GCC-Conference-Create confirm' to the Node Controller and a 'UserIDIndication' to the MCS Provider (repeated). The MCS Provider (repeated) then sends an 'MCS-Send-Data indication' to the Top GCC Provider. + +Sequence diagram showing the process of creating a conference between Node Controller, GCC Provider, and MCS Provider. + +T.124(01-07)\_F8-01 + +Figure 8-1 – Creating a conference + +### 8.2.2 Querying conferences + +On receipt of a GCC-Conference-Query request primitive, a GCC Provider shall issue an MCS-Connect-Provider request primitive with the parameters shown in Table 8-6. + +**Table 8-6 – MCS-Connect-Provider request parameters +for ConferenceQueryRequest PDU** + +| Parameter | Contents | +|-------------------------|--------------------------------------------| +| Calling Address | From request primitive | +| Calling Domain Selector | NULL | +| Called Address | From request primitive | +| Called Domain Selector | NULL | +| Upward/Downward Flag | Up | +| Domain Parameters | Default Domain Parameters | +| Quality of Service | Default Quality of Service Parameters | +| User Data | T.124 Object Identifier | +| | ConferenceQueryRequest PDU (see Table 8-7) | + +The User Data parameter of the MCS-Connect-Provider request contains a structure which includes an Object Identifier identifying the contained PDU as adhering to this Recommendation followed by the PDU itself. The details of this structure are defined in 9.6. The contents of this PDU are shown in Table 8-7. + +**Table 8-7 – ConferenceQueryRequest GCCPDU** + +| Content | Source | Sink | +|-----------------------------------|---------|------------| +| Node Type | Request | Indication | +| Asymmetry Indicator (conditional) | Request | Indication | +| User Data (optional) | Request | Indication | + +On receipt of the MCS-Connect-Provider indication that includes a T.124 Object Identifier and the ConferenceQueryRequest PDU, a GCC Provider shall generate a GCC-Conference-Query indication primitive with the parameters as specified in the ConferenceQueryRequest PDU. It shall issue this primitive to the Control GCCSAP. On receipt of a GCC-Conference-Query response from the Control GCCSAP, the GCC Provider shall send an MCS-Connect-Provider response which is rejected (i.e., no conference is set up), but includes the ConferenceQueryResponse PDU in the User Data field. The parameters of the MCS-Connect-Provider response are shown in Table 8-8. + +**Table 8-8 – MCS-Connect-Provider response parameters +for ConferenceQueryResponse PDU** + +| Parameter | Contents | +|--------------------|---------------------------------------------| +| Domain Parameters | Default Domain Parameters | +| Quality of Service | Default Quality of Service Parameters | +| Result | User-rejected | +| User Data | T.124 Object Identifier | +| | ConferenceQueryResponse PDU (see Table 8-9) | + +The ConferenceQueryResponse PDU is shown in Table 8-9. The Conference Descriptor List contains an entry for each listed conference to which the queried node is currently joined. The Conference Descriptor List is generated by the GCC Provider sourcing the ConferenceQueryResponse PDU. The descriptor is filled in with the Conference Name of each conference to which the GCC Provider is joined, the locally-maintained Conference Name Modifier for each conference, if any, the Conference Description, if any, the Locked/Unlocked flag, the Password In The Clear Required indicator, the Network Address field (if one is available), the default Conference Flag, and the Conference Mode. The Network Address field, if one exists, is sourced from the Local Network Address parameter of the GCC-Conference-Create request, the GCC-Conference-Create response, the GCC-Conference-Join request, or the GCC-Conference-Invite response, depending on how the conference was joined at this node. The Result parameter shall indicate success if the query request is able to be fulfilled (even if the Conference List is empty), or user-rejected if so indicated in the response primitive. + +If the GCC Provider processing the MCS-Connect-Provider indication receives an MCS-Disconnect-Provider indication for the same connection at any time during the process, the GCC Provider shall stop further processing for this procedure and take no further action. + +**Table 8-9 – ConferenceQueryResponse GCCPDU** + +| Content | Source | Sink | +|-----------------------------------|---------------------|---------| +| Node Type | Request | Confirm | +| Asymmetry Indicator (conditional) | Response | Confirm | +| Conference Descriptor List | Source GCC Provider | Confirm | +| Result | Response | Confirm | +| User Data (optional) | Response | Confirm | + +On receipt of an MCS-Connect-Provider response which includes the T.124 Object Identifier and a ConferenceQueryResponse PDU, a GCC Provider shall generate a GCC-Conference-Query confirm primitive and issue it to the Control GCCSAP. The content of the confirm primitive shall be obtained from the parameters of the ConferenceQueryResponse PDU. The Result parameter in the primitive, in particular, is obtained strictly from the Result parameter in the received PDU. The Result parameter of the MCS-Connect-Provider confirm is ignored since it would be set to user-rejected even in the case of a successful operation. + +If the received PDU had indicated an unsuccessful result, or if the GCC Provider receives an MCS-Disconnect-Provider indication for this connection prior to having issued a successful GCC-Conference-Query confirm, the GCC-Conference-Query confirm primitive is issued immediately, indicating an unsuccessful result. The Result parameter in the PDU as well as the Result parameter reported in the MCS-Connect-Provider confirm (or the Reason parameter of the MCS-Disconnect-Provider) is used to generate the result reported in the GCC-Conference-Query confirm primitive. If the Result parameter of the MCS-Connect-Provider confirm is user-rejected, the Result parameter in the PDU is used to determine the reported result. Otherwise, the Result parameter in the MCS-Connect-Provider is used directly. + +### 8.2.3 Joining a conference + +On receipt of the primitive GCC-Conference-Join request, a GCC Provider shall issue an MCS-Connect-Provider request primitive with the parameters shown in Table 8-10. The local GCC Provider allocates the Conference ID, which shall be used as the local MCS Domain Selector associated with the created conference. The Conference ID is sent as part of the MCS-Connect-Provider request as the Calling Domain Selector. + +**Table 8-10 – MCS-Connect-Provider request parameters +for ConferenceJoinRequest PDU** + +| Parameter | Contents | +|-------------------------|---------------------------------------------| +| Calling Address | From request primitive | +| Calling Domain Selector | Conference ID as chosen by the GCC Provider | +| Called Address | From request primitive | +| Called Domain Selector | NULL | +| Upward/Downward Flag | Up | +| Domain Parameters | From request primitive | +| Quality of Service | From request primitive | +| User Data | T.124 Object Identifier | +| | ConferenceJoinRequest PDU (see Table 8-11) | + +The User Data parameter of the MCS-Connect-Provider request contains a structure which includes an Object Identifier identifying the contained PDU as adhering to this Recommendation followed by the PDU itself. The details of this structure are defined in 9.6. The contents of this PDU are shown in Table 8-11. From the joining node, the Tag parameter shall not be included. The Conference Name and Conference Name Modifier are sourced from the request primitive – the Conference Name Modifier parameter in the PDU is sourced from the Called Node Conference Name Modifier parameter of the primitive. The Calling Node Conference Name Modifier (also from the request primitive) is maintained at the local GCC Provider as the identifiers of the conference to be used in the procedures for response to a conference join request and conference query request. + +**Table 8-11 – ConferenceJoinRequest GCCPDU** + +| Content | Source | Sink | +|-------------------------------------|--------------------------------------------------------|--------------------------------------------------------| +| Conference Name (conditional) | Request | GCC Provider receiving MCS-Connect-Provider indication | +| Conference Name Modifier (optional) | Request | GCC Provider receiving MCS-Connect-Provider indication | +| Tag (conditional) | GCC Provider receiving MCS-Connect-Provider indication | Top GCC Provider | +| Password (optional) | Request | Indication | +| Convener Password (optional) | Request | Indication | +| Caller Identifier (optional) | Request | Indication | +| Node category (optional) | Request | Indication | +| User Data (optional) | Request | Indication | + +On receipt of the MCS-Connect-Provider indication that includes a T.124 Object Identifier and the ConferenceJoinRequest PDU, the action of the GCC Provider depends on whether or not it is the Top GCC Provider of the conference specified by the Conference Name and Conference Name Modifier (if any). The GCC Provider determines which conference is to be joined by comparing the Conference Name and Conference Name Modifier to the list of conferences to which this node is joined. The Conference Name received in the ConferenceJoinRequest PDU may contain either the numerical or text forms of the Conference Name. The GCC Provider shall attempt to match the indicated name with the corresponding portion of the names of existing conferences. For a conference to be considered matched, both the Conference Name and Conference Name Modifier + +must match those of a current conference. If no Conference Name Modifier is given in the request, the GCC Provider shall match it only with an existing conference which also has no Conference Name Modifier. + +If the GCC Provider which received the MCS-Connect-Provider indication is not the Top GCC Provider for the conference to which the requesting node wishes to join, and if the node is joined to the specified conference, the GCC Provider shall forward the ConferenceJoinRequest PDU to the Top-GCC-Provider of the specified conference by issuing an MCS-Send-Data request specifying the Node ID Channel of the Top GCC Provider as the Channel ID, specifying Top data priority, and including the PDU in the Data field. In this case, it shall assign a locally unique identifier and include it in the Tag parameter of the PDU. This number is used to identify the corresponding response PDU when it is returned from the Top GCC Provider. It may also leave out the Conference Name and Conference Name Modifier parameters from the received PDU as they are not needed by the Top GCC Provider. + +When the Top-GCC-Provider receives this PDU, if the conference is not locked, it shall generate a GCC-Conference-Join indication primitive with the parameters as specified in the ConferenceJoinRequest PDU, as well as the Conference ID for the corresponding conference. It shall issue this primitive to the Control GCCSAP. Note that the Conference Name and Conference Name Modifier parameters are used only by the node receiving the MCS-Connect-Provider indication, and not by the Top GCC Provider. If the conference had been locked, the Top GCC Provider shall instead send a ConferenceJoinResponse PDU to the originator of the MCS-Send-Data containing the ConferenceJoinRequest PDU (not the original requester) by issuing an MCS-Send-Data request specifying the User ID of that node as the Channel ID, specifying Top data priority, and including the PDU in the Data field. The PDU shall indicate locked-conference as the result code. Otherwise, on receipt of the GCC-Conference-Join response, the GCC Provider shall send a ConferenceJoinResponse PDU to the originator of the MCS-Send-Data containing the ConferenceJoinRequest PDU (not the original requester) by issuing an MCS-Send-Data request specifying the User ID of that node as the Channel ID, specifying Top data priority, and including the PDU in the Data field. The contents of the ConferenceJoinResponse PDU are shown in Table 8-13. The Node ID is not included in this portion of the response, but the Top Node ID parameter, the Tag, and the parameters associated with the Conference Profile are included, as well as the Result parameter. The Tag shall have the same value as the corresponding parameter in the received ConferenceJoinRequest PDU. + +On receipt of the MCS-Send-Data indication containing this PDU, if the Tag parameter matches that of its locally-stored list of outstanding join requests (which allows it to identify the connection over which to send the MCS-Connect-Provider response), the GCC Provider shall generate an MCS-Connect-Provider response which includes a result which is either success, or user-rejected depending on whether or not the Result parameter in the received PDU indicated success or failure. The User Data parameter includes the T.124 Object Identifier as well as the ConferenceJoinResponse PDU. The Node ID parameter of the ConferenceJoinResponse PDU is filled in at this time indicating the Node ID of the node directly connected to the joining node. The contents of the connect provider primitive are shown in Table 8-12. + +If the receiver of the original MCS-Connect-Provider indication is the Top-GCC-Provider, if the conference is not locked, it shall instead generate a GCC-Conference-Join indication primitive with the parameters as specified in the ConferenceJoinRequest PDU, as well as the Conference ID for the designated conference. It shall issue this primitive to the Control GCCSAP. If the conference had been locked, the Top GCC Provider shall instead generate an MCS-Connect-Provider response which indicates in the included ConferenceJoinResponse PDU locked-conference as the result code. The PDU shall indicate locked-conference as the result code. Otherwise, on receipt of the GCC-Conference-Join response, the GCC Provider generates an MCS-Connect-Provider response which includes the ConferenceJoinResponse PDU with a result which is either success, or + +user-rejected depending on whether or not the Result parameter in the GCC-Conference-Join response primitive indicated success or failure. + +If the receiver of the original MCS-Connect-Provider indication is not currently joined to any conference (or if it does not support the GCC-Conference-Join indication primitive at all), it may reject the join request by immediately issuing an MCS-Connect-Provider response containing user-rejected as the result code, and including a ConferenceJoinResponse with invalid-conference respectively as the reason code in the PDU. + +If the receiver of the original MCS-Connect-Provider indication is not joined to the conference specified in the Conference Name and Conference Name Modifier parameter of the ConferenceJoinRequest PDU, it shall reject the request by issuing an MCS-Connect-Provider response with the reason of no-such-domain. + +**Table 8-12 – MCS-Connect-Provider response parameters for ConferenceJoinResponse PDU** + +| Parameter | Contents | +|--------------------|---------------------------------------------| +| Domain Parameters | From GCC Provider as previously saved | +| Quality of Service | From GCC Provider as previously saved | +| Result | As specified in [ITU-T T.122] | +| User Data | T.124 Object Identifier | +| | ConferenceJoinResponse PDU (see Table 8-13) | + +The ConferenceJoinResponse PDU is shown in Table 8-13. The Node ID parameter, which is the User ID assigned by MCS in response to the MCS-Attach-User request issued by the GCC Provider, shall be supplied by the GCC Provider at the node directly connected to the joining node. The Tag parameter is filled in by the GCC Provider at the node directly connected to the joining node with a locally unique value. It is used to identify the returned UserIDIndication PDU. The value of this parameter may be set to the value of the same parameter received from the Top GCC Provider since this parameter was allocated by this node originally as sent in the ConferenceJoinRequest PDU. If this is done, it requires that Tags used for either purpose are locally unique. The other parameters in this PDU are filled out by the Top GCC Provider. This includes the Top Node ID, which is the Node ID of the Top GCC Provider, as well as the parameters associated with the Conference Profile. Also filled in by the Top GCC Provider is the Conference Name Alias. This is conditionally included depending on whether the Conference Name included both numeric and text forms. If so, the Conference Name Alias is whichever form of the Conference Name was not included in the ConferenceJoinRequest PDU. The Result parameter includes GCC-specific failure information if the Result parameter in the MCS-Connect-Provider message is set to user-rejected. This information is from the Result parameter in the GCC-Conference-Create response PDU. + +**Table 8-13 – ConferenceJoinResponse GCCPDU** + +| Content | Source | Sink | +|-------------------------------------|---------------------------------------------------------|--------------------------------------| +| Node ID (conditional) | GCC Provider of node directly connected to joining node | Destination GCC Provider | +| Top Node ID | Top GCC Provider | Destination GCC Provider | +| Tag | Top GCC Provider | Destination GCC Provider | +| Conference Name Alias (conditional) | Top GCC Provider | Confirm and Destination GCC Provider | + +**Table 8-13 – ConferenceJoinResponse GCCPDU** + +| Content | Source | Sink | +|---------------------------------------------------------|------------------|--------------------------------------| +| Password In The Clear Required Flag | Top GCC Provider | Confirm and Destination GCC Provider | +| Locked Conference Flag | Top GCC Provider | Confirm and Destination GCC Provider | +| Listed Conference Flag | Top GCC Provider | Confirm and Destination GCC Provider | +| Conductible Conference Flag | Top GCC Provider | Confirm and Destination GCC Provider | +| Termination Method | Top GCC Provider | Confirm and Destination GCC Provider | +| Conductor Privilege List (optional) | Top GCC Provider | Confirm and Destination GCC Provider | +| Conducted-Mode Conference Privilege List (optional) | Top GCC Provider | Confirm and Destination GCC Provider | +| Non-Conducted-Mode Conference Privilege List (optional) | Top GCC Provider | Confirm and Destination GCC Provider | +| Conference Description (optional) | Top GCC Provider | Confirm and Destination GCC Provider | +| Password (optional) | Request | Indication | +| Node Category (optional) | Request | Indication | +| Result | Response | Confirm | +| User Data (optional) | Response | Confirm | + +On receipt of the ConferenceJoinResponse PDU, if the PDU indicated a successful result, a GCC Provider shall first issue an MCS-Attach-User request. On receipt of the MCS-Attach-User confirm which contains the allocated Node ID, the GCC Provider shall then join the corresponding Node ID Channel by issuing an MCS-Channel-Join request. The GCC Provider shall also join the appropriate GCC Broadcast Channel(s) by issuing one or two MCS-Channel-Join requests. All nodes are required to join the GCC-Conventional-Broadcast-Channel. All GCC control PDUs and Roster delta updates that are generated when Conventional Nodes join, leave, or change a roster record are broadcasted on this channel. Anonymous nodes may ignore the roster deltas received on this channel, but they must process the control messages received. Conventional Nodes must also join the GCC-Counted-Broadcast-Channel. On this channel, the Top Provider broadcasts Roster delta updates which are generated when Counted Nodes join, leave, or change a roster record. Because only Conventional Nodes join the GCC-Counted-Broadcast-Channel, the use of this channel reduces the amount of network traffic incurred when a large number of Counted Nodes are participating in a conference. Note that older protocol nodes join the GCC-Broadcast-Channel at this point. + +If the original GCC-Conference-Join request had specified the Convener Password, indicating that the node was to regain its role as the Conference Convener, the GCC Provider may also join the GCC-Convener-Channel (if it supports any of the functions which require use of this channel) by issuing an MCS-Channel-Join request. Once the GCC Provider has received an MCS-Channel-Join confirm from each of the channel join requests (successive requests may be issued prior to receiving the previous confirm), it shall send a UserIDIndication PDU to the GCC Provider of the directly connected node by issuing an MCS-Send-Data request specifying the Node ID of the directly connected node as contained in the received ConferenceJoinResponse PDU, specifying Top data priority, and including the PDU in the Data field. The content of the UserIDIndication PDU is + +shown in Table 8-5. The Tag parameter is filled in with the value of the corresponding parameter received in the ConferenceJoinResponse PDU. + +The GCC Provider shall then generate a GCC-Conference-Join confirm primitive and issue it to the Control GCCSAP. This primitive shall include the Result parameters from the received PDU as well as the locally-allocated Conference ID. If the received PDU had indicated an unsuccessful result, or if the GCC Provider receives an MCS-Disconnect-Provider indication for this connection prior to having issued a successful GCC-Conference-Join confirm, the GCC-Conference-Join confirm primitive is issued immediately, indicating an unsuccessful result, without issuing the attach-user or channel-join requests, or sending the UserIDIndication PDU. The Result parameter in the PDU as well as the Result parameter reported in the MCS-Connect-Provider confirm (or the Reason parameter of the MCS-Disconnect-Provider) is used to generate the result reported in the GCC-Conference-Join confirm primitive. If the Result parameter of the MCS-Connect-Provider confirm is user-rejected, the Result parameter in the PDU is used to determine the reported result. Otherwise, the Result parameter in the MCS-Connect-Provider is used directly. + +The Conference Name Alias received in the ConferenceJoinResponse PDU, if any, is appended with the Conference Name included in the ConferenceJoinRequest PDU to form the full Conference Name returned in the GCC-Conference-Join confirm. This full conference name (which includes the numerical form as well as text form of the Conference Name, if any) shall be maintained at the local GCC Provider as the identifiers of this conference to be used in the procedures for response to a conference join request, conference query request, and in initiation of a conference invite. + +On receipt of a UserIDIndication, the node directly connected to the joining node shall compare the Tag parameter to its list of nodes in the conference from which it is expecting this PDU. If the Tag matches one of these, it shall save the User ID of the source node (extracted from the MCS-Send-Data indication) in its database of Node IDs of nodes which are directly below it in the connection hierarchy. If the Tag does not match any outstanding Tags, the PDU shall be ignored. + +If the Top GCC Provider receives a UserIDIndication as a result of a successful join operation in which the Convener Password parameter had been included in the ConferenceJoinRequest PDU, the Top GCC Provider shall retain the Node ID of the joining node as indicated in the UserIDIndication as the valid conference convener. It shall use this to verify later requests which only the convener may perform. + +If the GCC Provider at the node directly connected to the joining node receives an MCS-Disconnect-Provider indication for the connection being established at any time during the joining process, the GCC Provider shall stop further processing for this procedure and take no further action. + +The sequence of events for successfully joining a conference from a node directly connected to the Top GCC Provider is shown in Figure 8-2. The case that the joining node is not directly connected to the Top GCC Provider is shown in Figure 8-3. + +![Sequence diagram showing the process of joining a conference when directly connected to the Top GCC Provider. The diagram involves four entities: Node Controller, GCC Provider, MCS Provider, and Top GCC Provider. The process starts with a GCC-Conference-Join request from the Node Controller to the GCC Provider, followed by an MCS-Connect-Provider request from the GCC Provider to the MCS Provider. The MCS Provider then sends a ConferenceJoinRequest to the Top GCC Provider, which responds with an MCS-Connect-Provider indication. The Top GCC Provider then sends a GCC-Conference-Join indication to the Node Controller, which responds with a GCC-Conference-Join response. The Top GCC Provider then sends an MCS-Connect-Provider response to the MCS Provider, which responds with a ConferenceJoinResponse to the GCC Provider. The GCC Provider then sends an MCS-Connect-Provider confirm to the MCS Provider. The MCS Provider then sends an MCS-Attach-User request to the GCC Provider, which responds with an MCS-Attach-User confirm. The MCS Provider then sends an MCS-Channel-Join request (Node ID Channel) to the GCC Provider, which responds with an MCS-Channel-Join confirm. The MCS Provider then sends an MCS-Channel-Join request (GCC-Broadcast-Channel) to the GCC Provider, which responds with an MCS-Channel-Join confirm. The MCS Provider then sends an MCS-Send-Data request to the GCC Provider. The GCC Provider then sends a GCC-Conference-Join confirm to the Node Controller. The MCS Provider then sends a UserIDIndication to the Top GCC Provider, which responds with an MCS-Send-Data indication.](9dc88fb2c48bc64047fc3e79814f1d47_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant GP as GCC Provider + participant MP as MCS Provider + participant TGP as Top GCC Provider + + NC->>GP: GCC-Conference-Join request + GP->>MP: MCS-Connect-Provider request + MP->>TGP: ConferenceJoinRequest + TGP->>MP: MCS-Connect-Provider indication + TGP->>NC: GCC-Conference-Join indication + NC->>TGP: GCC-Conference-Join response + TGP->>MP: MCS-Connect-Provider response + MP->>GP: ConferenceJoinResponse + GP->>MP: MCS-Connect-Provider confirm + MP->>GP: MCS-Attach-User request + GP->>MP: MCS-Attach-User confirm + MP->>GP: MCS-Channel-Join request (Node ID Channel) + GP->>MP: MCS-Channel-Join confirm + MP->>GP: MCS-Channel-Join request (GCC-Broadcast-Channel) + GP->>MP: MCS-Channel-Join confirm + MP->>GP: MCS-Send-Data request + GP->>NC: GCC-Conference-Join confirm + MP->>TGP: UserIDIndication + TGP->>MP: MCS-Send-Data indication + +``` + +T.124(01-07)\_F8-02 + +Sequence diagram showing the process of joining a conference when directly connected to the Top GCC Provider. The diagram involves four entities: Node Controller, GCC Provider, MCS Provider, and Top GCC Provider. The process starts with a GCC-Conference-Join request from the Node Controller to the GCC Provider, followed by an MCS-Connect-Provider request from the GCC Provider to the MCS Provider. The MCS Provider then sends a ConferenceJoinRequest to the Top GCC Provider, which responds with an MCS-Connect-Provider indication. The Top GCC Provider then sends a GCC-Conference-Join indication to the Node Controller, which responds with a GCC-Conference-Join response. The Top GCC Provider then sends an MCS-Connect-Provider response to the MCS Provider, which responds with a ConferenceJoinResponse to the GCC Provider. The GCC Provider then sends an MCS-Connect-Provider confirm to the MCS Provider. The MCS Provider then sends an MCS-Attach-User request to the GCC Provider, which responds with an MCS-Attach-User confirm. The MCS Provider then sends an MCS-Channel-Join request (Node ID Channel) to the GCC Provider, which responds with an MCS-Channel-Join confirm. The MCS Provider then sends an MCS-Channel-Join request (GCC-Broadcast-Channel) to the GCC Provider, which responds with an MCS-Channel-Join confirm. The MCS Provider then sends an MCS-Send-Data request to the GCC Provider. The GCC Provider then sends a GCC-Conference-Join confirm to the Node Controller. The MCS Provider then sends a UserIDIndication to the Top GCC Provider, which responds with an MCS-Send-Data indication. + +**Figure 8-2 – Joining a conference when directly connected to Top GCC Provider** + +![Sequence diagram showing the process of joining a conference when not directly connected to the Top GCC Provider. The diagram involves three groups of participants: Node Controller, GCC Provider, and MCS Provider; a second group of MCS Provider, GCC Provider, and MCS Provider; and a third group of MCS Provider, Top GCC Provider, and Node Controller. The process starts with a GCC-Conference-Join request from the Node Controller to the GCC Provider, followed by an MCS-Connect-Provider request to the MCS Provider. The MCS Provider then sends a ConferenceJoinRequest to the second MCS Provider, which in turn sends an MCS-Send-Data request to the Top GCC Provider. The Top GCC Provider sends an MCS-Send-Data indication to the second MCS Provider, which then sends a GCC-Conference-Join indication to the Node Controller. The Node Controller sends a GCC-Conference-Join response to the second MCS Provider, which then sends an MCS-Send-Data request to the second MCS Provider. The second MCS Provider sends a ConferenceJoinResponse to the second MCS Provider, which then sends an MCS-Send-Data indication to the second MCS Provider. The second MCS Provider sends an MCS-Connect-Provider response to the first MCS Provider, which then sends a ConferenceJoinResponse to the first MCS Provider. The first MCS Provider sends an MCS-Connect-Provider confirm to the first MCS Provider, followed by an MCS-Attach-User request and confirm. The first MCS Provider then sends an MCS-Channel-Join request (Node ID Channel) and confirm, followed by an MCS-Channel-Join request (GCC-Broadcast-Channel) and confirm. Finally, the first MCS Provider sends an MCS-Send-Data request to the first MCS Provider, which then sends a GCC-Conference-Join confirm to the first MCS Provider. The first MCS Provider sends a UserIDIndication to the second MCS Provider, which then sends an MCS-Send-Data indication to the second MCS Provider.](95be50ec094942200786128aa936cfae_img.jpg) + +``` + +sequenceDiagram + participant NCP as Node Controller + participant GCP as GCC Provider + participant MCP1 as MCS Provider + participant MCP2 as MCS Provider + participant GCP2 as GCC Provider + participant MCP3 as MCS Provider + participant TGCP as Top GCC Provider + participant NCC as Node Controller + + NCP->>GCP: GCC-Conference-Join request + GCP->>MCP1: MCS-Connect-Provider request + MCP1-->>MCP2: ConferenceJoinRequest + MCP1->>GCP2: MCS-Connect-Provider indication + GCP2->>MCP3: MCS-Send-Data request + MCP3-->>TGCP: ConferenceJoinRequest + TGCP->>MCP2: MCS-Send-Data indication + MCP2->>NCC: GCC-Conference-Join indication + NCC->>MCP2: GCC-Conference-Join response + MCP2->>MCP3: MCS-Send-Data request + MCP3-->>MCP2: ConferenceJoinResponse + MCP2->>MCP1: MCS-Send-Data indication + MCP1->>MCP2: MCS-Connect-Provider response + MCP2-->>MCP1: ConferenceJoinResponse + MCP1->>MCP1: MCS-Connect-Provider confirm + MCP1->>MCP1: MCS-Attach-User request + MCP1->>MCP1: MCS-Attach-User confirm + MCP1->>MCP1: MCS-Channel-Join request (Node ID Channel) + MCP1->>MCP1: MCS-Channel-Join confirm + MCP1->>MCP1: MCS-Channel-Join request (GCC-Broadcast-Channel) + MCP1->>MCP1: MCS-Channel-Join confirm + MCP1->>MCP1: MCS-Send-Data request + MCP1->>MCP1: GCC-Conference-Join confirm + MCP1->>MCP2: UserIDIndication + MCP2->>MCP3: MCS-Send-Data indication + +``` + +T.124(01-07)\_F8-03 + +Sequence diagram showing the process of joining a conference when not directly connected to the Top GCC Provider. The diagram involves three groups of participants: Node Controller, GCC Provider, and MCS Provider; a second group of MCS Provider, GCC Provider, and MCS Provider; and a third group of MCS Provider, Top GCC Provider, and Node Controller. The process starts with a GCC-Conference-Join request from the Node Controller to the GCC Provider, followed by an MCS-Connect-Provider request to the MCS Provider. The MCS Provider then sends a ConferenceJoinRequest to the second MCS Provider, which in turn sends an MCS-Send-Data request to the Top GCC Provider. The Top GCC Provider sends an MCS-Send-Data indication to the second MCS Provider, which then sends a GCC-Conference-Join indication to the Node Controller. The Node Controller sends a GCC-Conference-Join response to the second MCS Provider, which then sends an MCS-Send-Data request to the second MCS Provider. The second MCS Provider sends a ConferenceJoinResponse to the second MCS Provider, which then sends an MCS-Send-Data indication to the second MCS Provider. The second MCS Provider sends an MCS-Connect-Provider response to the first MCS Provider, which then sends a ConferenceJoinResponse to the first MCS Provider. The first MCS Provider sends an MCS-Connect-Provider confirm to the first MCS Provider, followed by an MCS-Attach-User request and confirm. The first MCS Provider then sends an MCS-Channel-Join request (Node ID Channel) and confirm, followed by an MCS-Channel-Join request (GCC-Broadcast-Channel) and confirm. Finally, the first MCS Provider sends an MCS-Send-Data request to the first MCS Provider, which then sends a GCC-Conference-Join confirm to the first MCS Provider. The first MCS Provider sends a UserIDIndication to the second MCS Provider, which then sends an MCS-Send-Data indication to the second MCS Provider. + +**Figure 8-3 – Joining a conference when not directly connected to Top GCC Provider** + +### 8.2.4 Inviting a node to a conference + +On receipt of a GCC-Conference-Invite request primitive, a GCC Provider shall issue an MCS-Connect-Provider request primitive with the parameters shown in Table 8-14. + +**Table 8-14 – MCS-Connect-Provider request parameters for ConferenceInviteRequest PDU** + +| Parameter | Contents | +|-------------------------|----------------------------------------------| +| Calling Address | From request primitive | +| Calling Domain Selector | Conference ID from request primitive | +| Called Address | From request primitive | +| Called Domain Selector | NULL | +| Upward/Downward Flag | Down | +| Domain Parameters | From GCC Provider as previously saved | +| Quality of Service | From GCC Provider as previously saved | +| User Data | T.124 Object Identifier | +| | ConferenceInviteRequest PDU (see Table 8-15) | + +The User Data parameter of the MCS-Connect-Provider request contains a structure which includes an Object Identifier identifying the contained PDU as adhering to this Recommendation followed by the PDU itself. The details of this structure are defined in 9.6. The contents of this PDU are shown in Table 8-15. The Conference Name is the name of the conference specified by the Conference ID in the request primitive as stored in the local Conference Profile. The Node ID parameter, which is the User ID assigned by MCS in response to the MCS-Attach-User request issued by the GCC Provider, shall be supplied by the source GCC Provider. The Top Node ID is the Node ID of the Top GCC Provider, previously saved by the inviting GCC Provider at the inviting node. The Tag parameter is assigned by the source GCC Provider to be locally unique. It is used to identify the returned UserIDIndication PDU. + +**Table 8-15 – ConferenceInviteRequest GCCPDU** + +| Content | Source | Sink | +|-----------------------------------------------------|---------------------|-----------------------------------------| +| Conference Name | Source GCC Provider | Destination GCC Provider and Indication | +| Node ID | Source GCC Provider | Destination GCC Provider | +| Top Node ID | Source GCC Provider | Destination GCC Provider | +| Tag | Source GCC Provider | Destination GCC Provider | +| Password In The Clear Required Flag | Source GCC Provider | Indication and Destination GCC Provider | +| Locked Conference Flag | Source GCC Provider | Indication and Destination GCC Provider | +| Listed Conference Flag | Source GCC Provider | Indication and Destination GCC Provider | +| Conductible Conference Flag | Source GCC Provider | Indication and Destination GCC Provider | +| Termination Method | Source GCC Provider | Indication and Destination GCC Provider | +| Conductor Privilege List (optional) | Source GCC Provider | Indication and Destination GCC Provider | +| Conducted-Mode Conference Privilege List (optional) | Source GCC Provider | Indication and Destination GCC Provider | + +**Table 8-15 – ConferenceInviteRequest GCCPDU** + +| Content | Source | Sink | +|---------------------------------------------------------|---------------------|-----------------------------------------| +| Non-Conducted-Mode Conference Privilege List (optional) | Source GCC Provider | Indication and Destination GCC Provider | +| Conference Description (optional) | Source GCC Provider | Indication and Destination GCC Provider | +| Caller Identifier (optional) | Request | Indication | +| Node Category | Request | Indication | +| User Data (optional) | Request | Indication | + +On receipt of the MCS-Connect-Provider indication that includes a T.124 Object Identifier and the ConferenceInviteRequest PDU, a GCC Provider shall generate a GCC-Conference-Invite indication primitive and issue it to the Control GCCSAP. The Conference ID in this primitive shall be assigned locally by the GCC Provider and shall be used as the local MCS Domain Selector. If GCC does not have the resources necessary to join a conference, it may generate the negative response automatically without generating the GCC-Conference-Invite indication. Otherwise, on receipt of the GCC-Conference-Invite response, the GCC Provider shall generate an MCS-Connect-Provider response which includes a result which is either success, or user-rejected depending on whether or not the Result parameter in the GCC-Conference-Invite response primitive indicated success or failure (and shall include the result in the ConferenceInviteResponse PDU). The User Data parameter includes the T.124 Object Identifier as well as the ConferenceInviteResponse PDU. The contents of the connect provider primitive are shown in Table 8-16. + +If the successful response includes the Conference Name Modifier parameter, the GCC Provider shall maintain this as well as the Conference Name parameter from the received ConferenceInviteRequest PDU (which includes both the numerical form as well as the text form of the Conference Name, if any) together as the local identifier of the conference to be used in the procedure for responding to a conference join request, a conference query request, or in initiating a conference invite request. If no Conference Name Modifier is present, only the Conference Name is maintained for this purpose. + +After sending the MCS-Connect-Provider response, if the invitation was acknowledged as successful, the GCC Provider shall issue an MCS-Attach-User request. On receipt of the MCS-Attach-User confirm which contains the allocated Node ID, the GCC Provider shall then join the corresponding Node ID Channel by issuing an MCS-Channel-Join request. The GCC Provider shall also join the appropriate GCC Broadcast Channel(s) by issuing one or two MCS-Channel-Join requests. All nodes are required to join the GCC-Conventional-Broadcast-Channel. All GCC control PDUs and Roster delta updates that are generated when Conventional Nodes join, leave, or change a roster record are broadcasted on this channel. Anonymous nodes may ignore the roster deltas received on this channel, but they must process the control messages received. Conventional Nodes must also join the GCC-Counted-Broadcast-Channel. On this channel, the Top Provider broadcasts Roster delta updates which are generated when Counted Nodes join, leave, or change a roster record. Because only Conventional Nodes join the GCC-Counted-Broadcast-Channel, the use of this channel reduces the amount of network traffic incurred when a large number of Counted Nodes are participating in a conference. Note that older protocol nodes join the GCC-Broadcast-Channel at this point. + +Once the GCC Provider has received an MCS-Channel-Join confirm from each of the channel join requests (successive requests may be issued prior to receiving the previous confirm), it shall send a UserIDIndication PDU to the GCC Provider of the directly connected node by issuing an + +MCS-Send-Data request specifying the Node ID of the directly connected node as contained in the received ConferenceInviteRequest PDU, specifying Top data priority, and including the PDU in the Data field. The content of the UserIDIndication PDU is shown in Table 8-5. The Tag parameter is filled in with the value of the corresponding parameter received in the ConferenceInviteRequest PDU. + +If the GCC Provider at the invited node receives an MCS-Disconnect-Provider indication for the connection being established at any time during the process of being joined to the conference (this includes the time that the GCC-Conference-Invite indication has been issued to the Control GCCSAP until the time that the UserIDIndication has been transmitted), it shall issue a GCC-Conference-Terminate indication to the Control GCCSAP indicating the requested normal termination as the reason if user-initiated was the reason provided in the MCS-Disconnect-Provider indication, and error termination otherwise. It shall then stop further processing for this connection establishment procedure. If the MCS-Disconnect-Provider indication was received prior to issuing the GCC-Conference-Invite indication to the Control GCCSAP, the GCC Provider shall stop further processing for this connection establishment procedure and take no further action. + +**Table 8-16 – MCS-Connect-Provider response parameters for ConferenceInviteResponse PDU** + +| Parameter | Contents | +|--------------------|-----------------------------------------------| +| Domain Parameters | From response primitive | +| Quality of Service | From response primitive | +| Result | As specified in [ITU-T T.122] | +| User Data | T.124 Object Identifier | +| | ConferenceInviteResponse PDU (see Table 8-17) | + +The ConferenceInviteResponse PDU is shown in Table 8-17. + +**Table 8-17 – ConferenceInviteResponse GCCPDU** + +| Content | Source | Sink | +|----------------------|----------|---------| +| Result | Response | Confirm | +| User Data (optional) | Response | Confirm | + +On receipt of the ConferenceInviteResponse PDU, if the result parameter of the MCS-Connect-Provider was successful, a GCC Provider shall record the User Data parameter to fill in to the GCC-Conference-Invite confirm primitive once it is generated on receipt of the pending UserIDIndication. If the result parameter was unsuccessful, or if the GCC Provider receives an MCS-Disconnect-Provider indication for this connection prior to having issued a successful GCC-Conference-Invite confirm, the GCC Provider shall immediately generate a GCC-Conference-Invite confirm primitive and issue it to the Control GCCSAP. The Result parameter in the PDU as well as the Result parameter reported in the MCS-Connect-Provider confirm (or the Reason parameter of the MCS-Disconnect-Provider) is used to generate the result reported in the GCC-Conference-Invite confirm primitive. If the Result parameter of the MCS-Connect-Provider confirm is user-rejected, the Result parameter in the PDU is used to determine the reported result. Otherwise, the Result parameter in the MCS-Connect-Provider is used directly. + +On receipt of a UserIDIndication, the node directly connected to the invited node shall compare the Tag parameter to its list of nodes in the conference from which it is expecting this PDU. If the Tag matches one of these, it shall save the User ID of the source node (extracted from the + +MCS-Send-Data indication) in its database of Node IDs of nodes which are directly below it in the connection hierarchy. If the Tag does not match any outstanding Tags, the PDU shall be ignored. + +If the Tag was from an outstanding conference invite, on receipt of the UserIDIndication, the GCC Provider shall generate a GCC-Conference-Invite confirm primitive and issue it to the Control GCCSAP with a successful result parameter. + +The sequence of events for successfully inviting a node to a conference is shown in Figure 8-4. + +![Sequence diagram showing the process of inviting a node to a conference between Node Controller, Inviting GCC Provider, MCS Provider, MCS Provider, Invited GCC Provider, and Node Controller.](b50f38be091844d58b11e3d47bc71e73_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant IGCP as Inviting GCC Provider + participant MCP as MCS Provider + participant MP as MCS Provider + participant IGP as Invited GCC Provider + participant NCP as Node Controller + + IGCP->>NC: GCC-Conference-Invite request + IGCP->>MCP: MCS-Connect-Provider request + MCP-->>MP: ConferenceInviteRequest + MP->>IGCP: MCS-Connect-Provider indication + IGCP->>NCP: GCC-Conference-Invite indication + NCP-->>IGCP: GCC-Conference-Invite response + IGCP->>MP: MCS-Connect-Provider response + MP-->>MCP: ConferenceInviteResponse + MCP->>IGCP: MCS-Connect-Provider confirm + MP->>IGP: MCS-Attach-User request + IGP-->>MP: MCS-Attach-User confirm + MP->>IGP: MCS-Channel-Join request (Node ID Channel) + IGP-->>MP: MCS-Channel-Join confirm + MP->>IGP: MCS-Channel-Join request (GCC-Broadcast-Channel) + IGP-->>MP: MCS-Channel-Join confirm + MP->>IGP: MCS-Send-Data request + IGP->>MP: UserIDIndication + MP->>IGCP: MCS-Send-Data indication + IGCP->>NC: GCC-Conference-Invite confirm + +``` + +T.124(01-07)\_F8-04 + +Sequence diagram showing the process of inviting a node to a conference between Node Controller, Inviting GCC Provider, MCS Provider, MCS Provider, Invited GCC Provider, and Node Controller. + +**Figure 8-4 – Inviting a node to a conference** + +### 8.2.5 Requesting to add a node to a conference + +On receipt of a GCC-Conference-Add request primitive, a GCC Provider shall send a ConferenceAddRequest PDU to the Top GCC Provider by issuing an MCS-Send-Data request specifying the Node ID Channel of the Top GCC Provider as the Channel ID, specifying High data priority, and including the PDU in the Data field. The contents of the ConferenceAddRequest PDU + +are shown in Table 8-18. The contents are filled in from the parameters passed in the GCC-Conference-Add request primitive. The Tag parameter is assigned by the requesting GCC Provider to be locally unique. This number is used to identify the corresponding response PDU when it is returned. + +**Table 8-18 – ConferenceAddRequest GCCPDU** + +| Content | Source | Sink | +|----------------------------------|-------------------------|--------------------------| +| Network Address | Request | Indication | +| Requesting Node | Requesting GCC Provider | Indication | +| Tag | Requesting GCC Provider | Destination GCC Provider | +| Adding MCU (optional) | Request | Top GCC Provider | +| Node Category (optional) | Request | Indication | +| User Data (optional) | Request | Indication | +| Network Address V2 (see Annex B) | Request | Indication | + +On receipt of a ConferenceAddRequest PDU, the Top GCC Provider shall first check whether the requesting node had the necessary privilege to add a node to the conference as indicated in the Conference Profile. If not, it shall reject the request by sending a ConferenceAddResponse PDU to the requesting node indicating invalid-requester as the result. The content of the ConferenceAddResponse PDU is shown in Table 8-19. If the requesting node had sufficient privilege, the Top GCC Provider shall then examine whether the Adding MCU parameter is present. If not present, or if the Adding MCU identifier is equal to the Node ID of the Top GCC Provider, the Top GCC Provider, if it supports the GCC-Conference-Add function, shall generate a GCC-Conference-Add indication primitive and issue it to the Control GCCSAP. The contents of the primitive are filled in from the contents of the received PDU. If the node does not support this function, it may reject the request by issuing a FunctionNotSupportedResponse PDU including the received ConferenceAddRequest in the response. + +If the optional Adding MCU parameter is present and set to a value other than that of the Node ID of the Top GCC Provider, the Top GCC Provider shall send a ConferenceAddRequest PDU to the Adding MCU by issuing an MCS-Send-Data request specifying the Node ID of the Adding MCU as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the PDU is the same as that of the received request PDU. On receipt of a ConferenceAddRequest PDU, a node which is not the Top GCC Provider, if it supports the GCC-Conference-Add function, shall first check that it has been received from the Top GCC Provider by examining the User ID from the received MCS-Send-Data indication. If it has been received from the Top GCC Provider, it shall generate a GCC-Conference-Add indication primitive and issue it to the Control GCCSAP. The contents of the primitive are filled in from the contents of the received PDU. If the User ID of the received PDU does not match the Node ID of the Top GCC Provider, the received PDU is ignored and no further action is taken. If the node does not support this function, it may reject the request by sending to the Top GCC Provider a FunctionNotSupportedResponse PDU including the received ConferenceAddRequest in the response. + +On receipt of a GCC-Conference-Add response primitive, a GCC Provider shall send a ConferenceAddResponse PDU to the requesting node by issuing an MCS-Send-Data request specifying the Node ID of the requesting node, specifying High data priority, and including the PDU in the Data field. In the case that the request had been routed through the Top GCC Provider to another node, the response is issued to the original requesting node as indicated by the Requesting Node parameter of the request PDU. The contents of the ConferenceAddResponse PDU are shown in Table 8-19. The contents are filled in from the parameters passed in the + +GCC-Conference-Add response primitive. The Tag shall have the same value as the corresponding parameter in the received ConferenceAddRequest PDU. + +**Table 8-19 – ConferenceAddResponse GCCPDU** + +| Content | Source | Sink | +|----------------------|---------------------|--------------------------| +| Tag | Source GCC Provider | Destination GCC Provider | +| Result | Response | Confirm | +| User Data (optional) | Response | Confirm | + +On receipt of a ConferenceAddResponse PDU, a GCC Provider shall generate a GCC-Conference-Add confirm primitive and issue it to the Control GCCSAP. The contents of the primitive are obtained from the parameters of the received PDU. + +### 8.2.6 Locking a conference + +On receipt of a GCC-Conference-Lock request primitive, a GCC Provider shall send a ConferenceLockRequest by issuing an MCS-Send-Data request specifying the Node ID Channel of the Top GCC Provider as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the ConferenceLockRequest PDU is shown in Table 8-20. There are no parameters in this PDU. + +**Table 8-20 – ConferenceLockRequest GCCPDU** + +| Content | Source | Sink | +|---------------------|--------|------| +| -- No parameters -- | | | + +On receipt of a ConferenceLockRequest PDU, if the Top GCC Provider supports the conference lock capability, it shall first determine if the requesting node has the privilege necessary to lock the conference based on the lock-unlock-privileges defined when the conference was created. If so, the Top GCC Provider shall generate a GCC-Conference-Lock indication primitive and issue it to the Control GCCSAP. The Source Node specified in the primitive shall be obtained from the Sender User ID in the MCS-Send-Data indication. On receipt of a GCC-Conference-Lock response, the GCC Provider shall send a ConferenceLockResponse PDU by issuing an MCS-Send-Data request specifying the Source Node indicated in the response as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the ConferenceLockResponse PDU is shown in Table 8-21. The Result parameter is generated from the result returned in the GCC-Conference-Lock response. + +If the requesting node did not have the proper privilege to support this operation, the request is immediately rejected without generating a GCC-Conference-Lock indication. This is done by generating a ConferenceLockResponse PDU specifying invalid-requester as the Result. + +The Top GCC Provider shall preserve the order of received ConferenceLockRequest PDUs and ConferenceUnlockRequest PDUs and their corresponding indication primitives issued to the Control GCCSAP, as well as between the response primitives from the Control GCCSAP and the ConferenceLockResponse and ConferenceUnlockResponse PDUs transmitted. + +At the requesting node, order shall also be preserved between the request primitives and the corresponding transmitted ConferenceLockRequest PDUs and ConferenceUnlockRequest PDUs as well as between the received ConferenceLockResponse and ConferenceUnlockResponse PDUs and the corresponding confirm primitives. + +If the Top GCC Provider does not support the conference lock capability, on receipt of a ConferenceLockRequest PDU, it shall immediately generate a FunctionNotSupportedResponse PDU including the received ConferenceLockRequest PDU in the response. + +**Table 8-21 – ConferenceLockResponse GCCPDU** + +| Content | Source | Sink | +|---------|----------|---------| +| Result | Response | Confirm | + +On receipt of a ConferenceLockResponse PDU, a GCC Provider shall generate a GCC-Conference-Lock confirm primitive and issue it to the Control GCCSAP. The result parameter in the confirm primitive is obtained from the Result field in the PDU. + +If the Top GCC Provider sends a ConferenceLockResponse which indicates a successful result, it shall also generate a ConferenceLockIndication PDU and send it to all nodes in the conference by issuing an MCS-Uniform-Send-Data request specifying the GCC-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the ConferenceLockIndication PDU is shown in Table 8-22. This PDU contains no parameters. + +**Table 8-22 – ConferenceLockIndication GCCPDU** + +| Content | Source | Sink | +|---------------------|--------|------| +| -- No parameters -- | | | + +On receipt of a ConferenceLockIndication PDU, a GCC Provider which supports the optional lock indication may generate a GCC-Conference-Lock-Report indication and issue it to the Control GCCSAP. Before it does so, it shall examine the User ID as indicated in the received MCS-Uniform-Send-Data indication and compare it to the Node ID of the Top GCC Provider. The GCC-Conference-Lock-Report primitive may only be generated if the received User ID matches the Node ID of the Top GCC Provider. Otherwise, the received PDU is ignored, and no further action is taken. + +If the Top GCC Provider becomes aware of a new node entering a conference by its presence in the Conference Roster and the conference is currently locked and if the possibility exists that the conference may have been unlocked when the node joined (or was invited to) the conference, the Top GCC Provider shall generate a ConferenceLockIndication PDU and send it to the new node by issuing MCS-Send-Data request specifying the Node ID of that node as the Channel ID, specifying High data priority, and including the PDU in the Data field. Alternatively, it may send this PDU to all nodes by issuing an MCS-Uniform-Send-Data request specifying the GCC-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. Although the flag indicating whether the conference is locked or unlocked is included in the information provided to the newly-joined node as part of the connection establishment process, this ensures that if the conference changed its lock state since the connection had been established, that the node is properly notified of the change. If there is no possibility that the lock state has changed since the node was joined (or was invited) into the conference (e.g., if the lock state has not changed since the creation of the conference), the Top GCC Provider need not send this PDU. + +### 8.2.7 Unlocking a conference + +On receipt of a GCC-Conference-Unlock request primitive, a GCC Provider shall send a ConferenceUnlockRequest by issuing an MCS-Send-Data request specifying the Node ID Channel of the Top GCC Provider as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the ConferenceUnlockRequest PDU is shown in Table 8-23. There are no parameters in this PDU. + +**Table 8-23 – ConferenceUnlockRequest GCCPDU** + +| Content | Source | Sink | +|---------------------|--------|------| +| -- No parameters -- | | | + +On receipt of a ConferenceUnlockRequest PDU, if the Top GCC Provider supports the conference unlock capability, it shall first determine if the requesting node has the privilege necessary to unlock the conference based on the lock-unlock-privileges defined when the conference was created. If so, the Top GCC Provider shall generate a GCC-Conference-Unlock indication primitive and issue it to the Control GCCSAP. The Source Node specified in the primitive shall be obtained from the Sender User ID in the MCS-Send-Data indication. On receipt of a GCC-Conference-Unlock response, the GCC Provider shall send a ConferenceUnlockResponse PDU by issuing an MCS-Send-Data request specifying the Source Node indicated in the response as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the ConferenceUnlockResponse PDU is shown in Table 8-24. The Result parameter is generated from the result returned in the GCC-Conference-Unlock response. + +If the requesting node did not have the proper privilege to support this operation, the request is immediately rejected without generating a GCC-Conference-Unlock indication. This is done by generating a ConferenceUnlockResponse PDU specifying invalid-requester as the Result. + +The Top GCC Provider shall preserve the order of received ConferenceLockRequest PDUs and ConferenceUnlockRequest PDUs and their corresponding indication primitives issued to the Control GCCSAP, as well as between the response primitives from the Control GCCSAP and the ConferenceLockResponse and ConferenceUnlockResponse PDUs transmitted. + +At the requesting node, order shall also be preserved between the request primitives and the corresponding transmitted ConferenceLockRequest PDUs and ConferenceUnlockRequest PDUs as well as between the received ConferenceLockResponse and ConferenceUnlockResponse PDUs and the corresponding confirm primitives. + +If the Top GCC Provider does not support the conference unlock capability, on receipt of a ConferenceUnlockRequest PDU, it shall immediately generate a FunctionNotSupportedResponse PDU including the received ConferenceUnlockRequest PDU in the response. + +**Table 8-24 – ConferenceUnlockResponse GCCPDU** + +| Content | Source | Sink | +|---------|----------|---------| +| Result | Response | Confirm | + +On receipt of a ConferenceUnlockResponse PDU, a GCC Provider shall generate a GCC-Conference-Unlock confirm primitive and issue it to the Control GCCSAP. The result parameter in the confirm primitive is obtained from the Result field in the PDU. + +If the Top GCC Provider sends a ConferenceUnlockResponse which indicates a successful result, it shall also generate a ConferenceUnlockIndication PDU and send it to all nodes in the conference by issuing an MCS-Uniform-Send-Data request specifying the GCC-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the ConferenceUnlockIndication PDU is shown in Table 8-25. This PDU contains no parameters. + +**Table 8-25 – ConferenceUnlockIndication GCCPDU** + +| Content | Source | Sink | +|---------------------|--------|------| +| -- No parameters -- | | | + +On receipt of a ConferenceUnlockIndication PDU, a GCC Provider which supports the optional unlock indication may generate a GCC-Conference-Lock-Report indication and issue it to the Control GCCSAP. Before it does so, it shall examine the User ID as indicated in the received MCS-Uniform-Send-Data indication and compare it to the Node ID of the Top GCC Provider. The GCC-Conference-Lock-Report primitive may only be generated if the received User ID matches the Node ID of the Top GCC Provider. Otherwise, the received PDU is ignored, and no further action is taken. + +If the Top GCC Provider becomes aware of a new node entering a conference by its presence in the Conference Roster and the conference is currently unlocked and if the possibility exists that the conference may have been locked when the node joined (or was invited to) the conference, the Top GCC Provider shall generate a ConferenceUnlockIndication PDU and send it to the new node by issuing MCS-Send-Data request specifying the Node ID of that node as the Channel ID, specifying High data priority, and including the PDU in the Data field. Alternatively, it may send this PDU to all nodes by issuing an MCS-Uniform-Send-Data request specifying the GCC-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. Although the flag indicating whether the conference is locked or unlocked is included in the information provided to the newly-joined node as part of the connection establishment process, this ensures that if the conference changed its lock state since the connection had been established, that the node is properly notified of the change. If there is no possibility that the lock state has changed since the node was joined (or was invited) into the conference (e.g., if the lock state has not changed since the creation of the conference), the Top GCC Provider need not send this PDU. + +### **8.2.8 Disconnecting from a conference** + +On receipt of a GCC-Conference-Disconnect request, a GCC Provider shall first attempt to eject the nodes directly below it in the connection hierarchy, if any. It shall do this by sending, for each such node, a ConferenceEjectUserIndication PDU with the Node To Eject parameter set to the Node ID of the particular subordinate node and specifying higher-node-disconnected as the reason. This is done by issuing an MCS-Uniform-Send-Data request specifying both the GCC-Broadcast-Channel (to support older protocol nodes) and the GCC-Conventional-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the data field. The content of the ConferenceEjectUserIndication PDU is shown in Table 8-31. The GCC Provider shall then wait until it has received MCS-Disconnect-Provider indications from each subordinate connection. Following this, it shall disconnect from the conference by issuing first an MCS-Detach-User request followed by an MCS-Disconnect-Provider request directed at the upward connection (the only remaining connection). If, for some reason, the GCC Provider has not received MCS-Disconnect-Provider indications from each of the lower nodes within a reasonable period of time (determined locally), the GCC Provider may proceed to disconnect those connections itself by issuing MCS-Disconnect-Provider requests directed at each remaining lower connection, followed by an MCS-Detach-User request and an MCS-Disconnect-Provider request directed at the upward connection as in the normal case. In either case, or if there had been no subordinate nodes, the GCC Provider shall then generate a GCC-Conference-Disconnect confirm primitive and issue it to the Control GCCSAP. The GCC Provider shall then remove all database information associated with this conference. + +On receipt of an MCS-Detach-User indication, each GCC Provider in the conference shall examine the User ID indicated in the indication and compare it to its list of Node IDs in its local copy of the Conference Roster. If the User ID corresponds to a Node ID, different from its own Node ID, the GCC Provider shall generate a GCC-Conference-Disconnect indication and issue it to the Control GCCSAP. The Disconnecting Node parameter in the indication shall correspond to the User ID in the received indication. If the reason code in the received indication is user-initiated, the reason code in the GCC-Conference-Disconnect indication shall be either user-initiated or ejected node, depending on whether or not a ConferenceEjectUserIndication PDU was received earlier containing + +in its Node To Eject field the same User ID as the MCS-Detach-User indication. Otherwise, the reason is indicated as unknown. + +### 8.2.9 Terminating a conference + +On receipt of a GCC-Conference-Terminate request, a GCC Provider shall send a ConferenceTerminateRequest PDU to the Top GCC Provider by issuing an MCS-Send-Data request specifying the Node ID Channel of the Top GCC Provider as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the ConferenceTerminateRequest PDU is shown in Table 8-26. The reason code is obtained from the corresponding parameter in the request primitive. + +**Table 8-26 – ConferenceTerminateRequest GCCPDU** + +| Content | Source | Sink | +|---------|---------|------------------| +| Reason | Request | Top GCC Provider | + +On receipt of a ConferenceTerminateRequest PDU, the Top GCC Provider shall first determine if the requesting node has the privilege necessary to terminate the conference based on the terminate-privileges defined when the conference was created. If not, the request is rejected and a ConferenceTerminateResponse is sent back to the requester by issuing an MCS-Send-Data request specifying the Node ID Channel of the requester as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the ConferenceTerminateResponse PDU is shown in Table 8-27. In this case, the result parameter is set to indicate invalid-requester as the reason for rejection. + +If the requester did have the proper privilege to terminate the conference, then a ConferenceTerminateResponse shall be sent back to the requester indicating a successful result. In addition, a ConferenceTerminateIndication is sent to all nodes in the conference by issuing an MCS-Uniform-Send-Data request specifying both the GCC-Broadcast-Channel (to support older protocol nodes) and the GCC-Conventional-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the ConferenceTerminateIndication PDU is shown in Table 8-28. The reason code is obtained from the reason code in the request PDU. + +**Table 8-27 – ConferenceTerminateResponse GCCPDU** + +| Content | Source | Sink | +|---------|------------------|---------| +| Result | Top GCC Provider | Confirm | + +**Table 8-28 – ConferenceTerminateIndication GCCPDU** + +| Content | Source | Sink | +|---------|------------------|---------| +| Result | Top GCC Provider | Confirm | + +On receipt of a ConferenceTerminateResponse PDU, a GCC Provider shall generate a GCC-Conference-Terminate confirm primitive and issue it to the Control GCCSAP. The result indicated in the primitive is obtained directly from the Result parameter in the PDU. + +On receipt of a ConferenceTerminateIndication PDU sent by the Top GCC Provider, a GCC Provider shall first wait until it has received MCS-Disconnect-Provider indications from each connection directly below it in the connection hierarchy. Following this, it shall disconnect from the conference by issuing an MCS-Disconnect-Provider request directed at the upward connection (the only remaining connection). If, for some reason, the GCC Provider has not received + +MCS-Disconnect-Provider indications from each of the lower nodes within a reasonable period of time (determined locally), the GCC Provider may proceed to disconnect those connections itself by issuing MCS-Disconnect-Provider requests directed at each remaining lower connection, followed by an MCS-Disconnect-Provider request directed at the upward connection as in the normal case. In either case, the GCC Provider shall then generate a GCC-Conference-Terminate indication primitive and issue it to the Control GCCSAP. The reason indicated in the primitive is obtained directly from the Reason parameter in the PDU. + +If a GCC Provider receives an MCS-Disconnect-Provider indication from the local MCS provider corresponding to its upward MCS connection, this is an indication that the MCS connection has been terminated due to an abnormal condition within MCS, the GCC Provider shall generate a GCC-Conference-Terminate indication primitive and issue it to the Control GCCSAP. The reason code shall indicate that this is an error termination. + +If the Top GCC Provider receives a disconnect indication (either via PDU or MCS-Detach-User indication) which results in no nodes listed in the Conference Roster with the exception of the local node, the provider shall check the Conference Profile to determine if the conference is manually or automatically terminating. If it was manually terminating, no further action is taken. If it was automatically terminating, the GCC Provider shall indicate to the local node controller that the conference has been terminated by generating a GCC-Conference-Terminate indication and issuing it to the Control GCCSAP. The reason code shall indicate that there are no more nodes joined to an automatically terminating conference. The GCC Provider shall then remove all database information associated with this conference. + +### 8.2.10 Ejecting a node from a conference + +On receipt of a GCC-Conference-Eject-User request primitive, a GCC Provider shall first compare the Node To Eject parameter to the Node IDs of the nodes immediately below it in the connection hierarchy, if any. If the Node To Eject is a node other than a directly subordinate node, the GCC Provider shall send a ConferenceEjectUserRequest PDU to the Top GCC Provider by issuing an MCS-Send-Data request specifying the Node ID Channel of the Top GCC Provider as the Channel ID, specifying Top data priority, and including the PDU in the Data field. The content of the ConferenceEjectUserRequest PDU is shown in Table 8-29. The contents of the PDU are obtained from the request primitive. + +If the Node To Eject is a node directly below the local node in the connection hierarchy, the GCC Provider shall instead send a ConferenceEjectUserIndication PDU to all nodes specifying the Node ID of the node to be ejected in the PDU and the reason as indicated in the request primitive. It shall do this by issuing an MCS-Uniform-Data request specifying both the GCC-Broadcast-Channel (for older protocol nodes) and the GCC-Conventional-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the data field. The content of the ConferenceEjectUserIndication is shown in Table 8-31. The GCC Provider may then wait until it has received an MCS-Disconnect-Provider indication from the connection corresponding to the ejected node. If, for some reason, the GCC Provider has not received MCS-Disconnect-Provider indications from the ejected node within a reasonable period of time (determined locally), the GCC Provider may proceed to disconnect those connections itself by issuing an MCS-Disconnect-Provider request directed at the ejected node. The GCC Provider shall then generate a GCC-Conference-Eject-User confirm PDU indicating a successful result. + +**Table 8-29 – ConferenceEjectUserRequest GCCPDU** + +| Content | Source | Sink | +|---------------|---------|------------------| +| Node To Eject | Request | Top GCC Provider | +| Reason | Request | Top GCC Provider | + +On receipt of a ConferenceEjectUserRequest PDU, the Top GCC Provider shall first determine if the requesting node has the privilege necessary to eject a user based on the eject-user-privileges defined when the conference was created. If not, the request is rejected and a ConferenceEjectUserResponse is sent back to the requester by issuing an MCS-Send-Data request specifying the Node ID Channel of the requester as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the ConferenceEjectUserResponse PDU is shown in Table 8-30. In this case, the result parameter is set to indicate invalid-requester as the reason for rejection. + +If the requester did have the proper privilege to eject a user, then a ConferenceEjectUserIndication primitive is broadcast to all nodes by issuing an MCS-Uniform-Send-Data request. This request specifies both the GCC-Broadcast-Channel (for older protocol nodes) and the GCC-Conventional-Broadcast-Channel as the Channel ID, specifying Top data priority, and including the PDU in the Data field. The content of the ConferenceEjectUserIndication PDU is shown in Table 8-31. The Reason parameter in this PDU is obtained from the request PDU. If the node to be ejected is valid, a response is sent back to the requester indicating a successful result. If it is not possible to eject the requested node, a response is sent which includes a negative result. + +**Table 8-30 – ConferenceEjectUserResponse GCCPDU** + +| Content | Source | Sink | +|---------------|------------------|---------| +| Node To Eject | Top GCC Provider | Confirm | +| Result | Top GCC Provider | Confirm | + +On receipt of a ConferenceEjectUserResponse PDU, a GCC Provider shall generate a GCC-Conference-Eject-User confirm primitive and issue it to the Control GCCSAP. The contents of the confirm primitive are obtained from the ConferenceEjectUserResponse PDU. + +**Table 8-31 – ConferenceEjectUserIndication GCCPDU** + +| Content | Source | Sink | +|---------------|------------------|------------| +| Node To Eject | Top GCC Provider | Confirm | +| Reason | Top GCC Provider | Indication | + +On receipt of a ConferenceEjectUserIndication PDU, a GCC Provider shall compare the Node To Eject parameter to its own Node ID. If they are the same, it shall then compare the User ID as indicated in the MCS-Send-Data indication to the Node ID of the Top GCC Provider and to that of the node directly above it in the connection hierarchy. If the source Node ID is the same as either of these, it shall immediately disconnect from the conference by first attempting to eject the nodes directly below it in the connection hierarchy, if any. It shall do this by sending, for each such node, a ConferenceEjectUserIndication PDU with the Node To Eject parameter set to the Node ID of the particular subordinate node and specifying higher-node-ejected as the reason. This is done by issuing an MCS-Uniform-Send-Data request specifying both the GCC-Broadcast-Channel (for older protocol nodes) and the GCC-Conventional-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the data field. The GCC Provider shall then wait until it has received MCS-Disconnect-Provider indications from each subordinate connection. Following this, it shall disconnect from the conference by issuing first an MCS-Detach-User request followed by an MCS-Disconnect-Provider request directed at the upward connection (the only remaining connection). If, for some reason, the GCC Provider has not received MCS-Disconnect-Provider indications from each of the lower nodes within a reasonable period of time (determined locally), the GCC Provider may proceed to disconnect those connections itself by issuing MCS-Disconnect-Provider requests directed at each remaining lower connection, followed by first an MCS-Detach- + +User request followed by an MCS-Disconnect-Provider request directed at the upward connection as in the normal case. In either case, or if there had been no subordinate nodes, the GCC Provider shall then generate a GCC-Conference-Eject-User indication primitive and issue it to the Control GCCSAP. If the PDU is received with a User ID not matching the Node ID of the Top GCC Provider or the node directly above in the connection hierarchy, the PDU shall be ignored with no further action taken. + +If the receiving GCC Provider is an MCU which is directly connected above the node to be ejected in the connection hierarchy, it may optionally disconnect the node to be ejected from the conference by issuing an MCS-Disconnect-Provider request for the corresponding MCS connection. Prior to taking such action, it shall verify that the User ID indicated in the received PDU is the same as the Node ID of the Top GCC Provider. + +On receipt of a ConferenceEjectUserIndication PDU sent either by the Top GCC Provider or by the Node ID of the node listed in the conference roster as above the node to be ejected, all nodes except the node to be ejected shall make a note of this event and consult it later if an MCS-Detach-User indication should arrive for the node to be ejected. At that time, as specified in 8.2.8, a node shall generate a GCC-Conference-Disconnect indication and issue it to the Control GCCSAP. The reason indicated shall be ejected-node. + +### 8.2.11 Transferring nodes between conferences + +On receipt of a GCC-Conference-Transfer request primitive, a GCC Provider shall send a ConferenceTransferRequest PDU to the Top GCC Provider by issuing an MCS-Send-Data request specifying the Node ID Channel of the Top GCC Provider as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the ConferenceTransferRequest PDU is shown in Table 8-32. All of the parameters in this PDU are obtained directly from the request primitive. + +**Table 8-32 – ConferenceTransferRequest GCCPDU** + +| Content | Source | Sink | +|-------------------------------------|---------|------------------| +| Conference Name | Request | Top GCC Provider | +| Conference Name Modifier (optional) | Request | Top GCC Provider | +| Network Address (optional) | Request | Top GCC Provider | +| Transferring Nodes (optional) | Request | Top GCC Provider | +| Password (optional) | Request | Top GCC Provider | +| Network Address V2 (see Annex B) | Request | Indication | + +On receipt of a ConferenceTransferRequest PDU, the Top GCC Provider shall first determine if the requesting node has the privilege necessary to request a transfer based on the transfer-privileges defined when the conference was created. If not, the request is rejected and a ConferenceTransferResponse is sent back to the requester by issuing an MCS-Send-Data request specifying the Node ID Channel of the requester as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the ConferenceTransferResponse PDU is shown in Table 8-33. In this case, the result parameter is set to indicate invalid-requester as the reason for rejection. + +If the requester did have the proper privilege to request a transfer, then a the Top GCC Provider shall send a ConferenceTransferResponse PDU back to the requester as described above, but with the result parameter indicating success. It shall then broadcast a ConferenceTransferIndication PDU to all nodes in the conference by issuing an MCS-Uniform-Send-Data request specifying both the GCC-Broadcast-Channel (for older protocol nodes) and the GCC-Conventional-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. The + +content of the ConferenceTransferIndication PDU is shown in Table 8-34. The parameters in this PDU are obtained from the received ConferenceTransferRequest PDU. + +**Table 8-33 – ConferenceTransferResponse GCCPDU** + +| Content | Source | Sink | +|-------------------------------------|------------------|---------| +| Conference Name | Top GCC Provider | Confirm | +| Conference Name Modifier (optional) | Top GCC Provider | Confirm | +| Transferring Nodes (optional) | Top GCC Provider | Confirm | +| Result | Top GCC Provider | Confirm | + +On receipt of a ConferenceTransferResponse PDU, a GCC Provider shall generate a GCC-Conference-Transfer confirm primitive and issue it to the Control GCCSAP. The contents of the confirm primitive are obtained from the ConferenceTransferResponse PDU. + +**Table 8-34 – ConferenceTransferIndication GCCPDU** + +| Content | Source | Sink | +|-------------------------------------|------------------|------------| +| Conference Name | Top GCC Provider | Indication | +| Conference Name Modifier (optional) | Top GCC Provider | Indication | +| Network Address (optional) | Top GCC Provider | Indication | +| Transferring Nodes (optional) | Top GCC Provider | Indication | +| Password (optional) | Top GCC Provider | Indication | +| Network Address V2 (see Annex B) | Request | Indication | + +On receipt of a ConferenceTransferIndication PDU, a GCC Provider which supports the GCC-Conference-Transfer indication primitive shall check the list of destination nodes. If the local Node ID is found on the list of destination nodes, or if the list of destination nodes is NULL, the GCC Provider shall then check that the User ID indicated in the MCS-Uniform-Send-Data indication matches the Node ID of the Top GCC Provider. If they match, it shall generate a GCC-Conference-Transfer indication primitive and issue it to the Control GCCSAP. If the GCC Provider does not support the GCC-Conference-Transfer indication primitive, if the local node is not on the list of destination nodes, or if the received PDU is not from the Top GCC Provider, the PDU is ignored and no further action is taken. + +## 8.3 The conference and application rosters + +### 8.3.1 Original Roster Protocol vs. Scalable Roster Protocol + +At one time, the exchange of roster information was the single largest inhibitor of scaled conferences within T.124. Because of the features added to GCC to support scalable conferences, including Node Categories, the GCC-Conventional-Broadcast-Channel, and the GCC-Counted-Broadcast-Channel, the protocol associated with the exchange of Conference and Application Rosters underwent some dramatic changes. To ensure that backward compatibility is maintained with older protocol nodes, it is necessary to describe both the Original Roster Protocol and the Scalable Roster Protocol in separate sections. It is important that all T.124 nodes support both the Original Roster Protocol and the Scalable Roster Protocol to guarantee backward compatibility. Note that the description of the Original Roster Protocol provides all the information about the roster protocol necessary to support legacy nodes. All the information describing the Scalable Roster Protocol is contained in the subclause following the description of the Original Roster Protocol (see 8.3.3). + +### 8.3.2 Original Roster Protocol + +This subclause describes in detail all aspects of the Original Roster Protocol. The original protocol is not considered to be scalable due to the use of Full Roster Refreshes, which are propagated to all nodes in a conference any time a node joins, leaves, or changes a roster record. Nodes attempting to support legacy nodes must join the original GCC-Broadcast-Channel and implement the protocol detailed below. Note that nodes that only support the Original Roster Protocol are not aware of Node Categories and, therefore, only support Conventional nodes. + +#### 8.3.2.1 Overview + +Both the Conference and Application Rosters are communicated among nodes using the same set of PDUs. A single PDU, the RosterUpdateIndication PDU, is associated with all aspects of this exchange. This PDU is used to send complete or partial roster information to other nodes in the conference. + +When each node (other than the top node) first announces its roster information upon joining a conference, it is done by sending a RosterUpdateIndication to the node directly above it in the hierarchy. Subsequent updates to any portion of either the Conference or Application Roster information are announced by re-issuing a RosterUpdateIndication containing the new information. + +When a node updates its portion of the roster (or announces it for the first time), that information is propagated from node-to-node up the connection hierarchy until it reaches the Top GCC Provider which is responsible for forming the full Conference and Application rosters and distributing them to all nodes in the conference. + +As the roster information propagates up the connection hierarchy, each intermediate node (MCU) is responsible for forming a subset of the full Conference and Application Rosters. That subset includes that node as well as all nodes below it in the connection hierarchy. That is, the Conference Roster includes the Node Record for all such nodes, the Application Roster entries for each Application Protocol Session includes the Application Records for each such node with that Peer Application Protocol Entity enrolled, and the Application Capabilities List for each Application Protocol Session includes the collapsed capabilities information for all such nodes. On receipt of a RosterUpdateIndication from a node below, an intermediate node makes the appropriate changes to its subset of the rosters, then passes this information up to the next higher node by issuing a RosterUpdateIndication. + +If the update from a lower node included a change which caused the Application Capabilities Lists for at least one Application Protocol Session to have to be re-computed, the new roster information for the roster subset can only be generated if the individual Application Capabilities Lists for each node directly below in the connection hierarchy is known (to allow the collapse rules to be re-applied with the new updated information). The GCC Provider at each node shall maintain this information locally. + +When the roster updates have reached the Top GCC Provider, it shall then broadcast the new roster information to all nodes in the conference. This is done by broadcasting a RosterUpdateIndication PDU to all nodes. + +Roster information sent using the RosterUpdateIndication PDU may be sent in one of three ways. The roster may be sent as refresh of the full Conference and Application Rosters, replacing all existing roster entries. Alternatively, portions of the roster may be sent whereby the Conference Roster, and/or portions of the Application Roster associated one or more Session Keys may be refreshed. In this case, all entries in the transmitted portion of the roster are replaced, but portions that are not sent are left unchanged. Finally, changes to portions of the roster may be sent as updates whereby only those particular elements of the roster (e.g., individual Application Records) which have been added, modified, or removed are sent, and all other entries are left unchanged. When the Top GCC Provider broadcasts new roster information, only the first two methods are used. When + +the Top GCC Provider broadcasts new roster information which has changed due to at least one node having joined the conference, it shall broadcast this information only as a full refresh since the new node or nodes have no prior roster information. When propagating roster information up the connection hierarchy, any of these three methods may be used. The method chosen depends on the scope of the information changed, and is ideally chosen on the basis of minimizing the size of the PDU in order to minimize transmission time. + +NOTE – The described mechanism requires that all GCC Providers in a conference store the subset of the Conference and Application Rosters for their own node as well as nodes connected directly below them in the connection hierarchy. In addition, various functions require that the GCC Providers also store the full Conference and Application Rosters as broadcast from the Top GCC Provider. If for some reason a GCC Provider fails to retain some or all of this information, the only recourse is to disconnect from the conference and, if possible, to rejoin at a later time. + +#### **8.3.2.2 Nodes entering a conference** + +When a node is joined to a conference, either via conference creation, joining, or invitation, a GCC Provider shall issue a GCC-Application-Permission-To-Enroll indication to the GCCSAP for all Application Protocol Entities which have locally indicated their presence to the GCC Provider. In the case that a GCC Provider becomes aware of an additional Application Protocol Entity while it is already joined to a conference, the GCC Provider shall issue a GCC-Application-Permission-To-Enroll indication to the corresponding GCCSAP indicating the existence of this conference. + +Before taking any further action, the GCC Provider shall wait until it has received a GCC-Conference-Announce-Presence request from the Control GCCSAP as well as a GCC-Application-Enroll request from all Application Protocol Entities which have been sent GCC-Application-Permission-To-Enroll indications. Some of these enroll requests may indicate that that Application Protocol Entity does not intend to enroll (the enroll/un-enroll flag is set to un-enroll). For each received GCC-Application-Enroll request with the enroll flag set, the information provided in the primitive for that Application Protocol Entity is added to the Local Application Roster. + +The GCC Provider shall also assign a locally-allocated Entity ID to each enrolled Application Protocol Entity. This shall be used by the GCC Provider as an identifier of each corresponding Application Protocol Entity in the RosterUpdateIndication PDU. The assigned Application Protocol Entity ID is also included in the GCC-Application-Enroll confirm primitive returned to each enrolling Application Protocol Entity along with the Node ID of the local node. The Entity ID is a 16-bit integer value which is to be unique among all Application Protocol Entities enrolled at a node. If an Application Protocol Entity un-enrolls, the value of its Entity ID shall not be re-used unless all other values not assigned to an Application Protocol Entity at the time of the un-enroll have been assigned. + +The GCC Provider shall examine the Conducting Operation Capable Flag of each enrolled Application Protocol Entity with the Active/Inactive flag set to Active (inactive Application Protocol Entities are assumed not to be capable of conducting operation). If there is more than one such enrolled Application Protocol Entity with this flag set, the GCC Provider shall choose one of them for which to set this flag in the Application Roster information which is to be sent in the RosterUpdateIndication PDU. The rule for which of these to choose is a local matter not specified in this Recommendation. A typical rule may be to choose the first such Application Protocol Entity that enrolls. + +Upon receiving the GCC-Conference-Announce-Presence request from the Control GCCSAP and a GCC-Application-Enroll request from all Application Protocol Entities, a GCC Provider which is not the Top GCC Provider shall send a RosterUpdateIndication to the GCC Provider directly above it in the connection hierarchy. This is done by issuing an MCS-Send-Data request specifying the Node ID of the destination node as the Channel ID, specifying High data priority, and including the PDU in the Data field. The Node ID of the node directly above in the connection hierarchy is + +determined at the time of connection to the conference from either the ConferenceCreateResponse, ConferenceJoinResponse, or ConferenceInviteRequest PDUs, depending on how the conference was joined. The value of the Node ID of the above node shall also be included in the conference roster portion of the PDU as the Superior Node parameter. The content of the RosterUpdateIndication PDU is shown in Table 8-35. In this case, the roster is sent as a full refresh, including the local Node Record as well as the Application Records for all enrolled Application Protocol Entities and the Application Capabilities Lists for all Application Protocol Sessions corresponding to enrolled Application Protocol Entities. If there had been more than one Application Protocol Entity locally enrolled for a given Application Protocol Session, the GCC Provider shall perform a collapse of the Application Capabilities List among the Peer Application Protocol Entities to produce the Application Capabilities List which is to be included in the RosterUpdateIndication PDU for that Application Protocol Session. This collapse shall be done by the procedure described in 8.3.2.8. The action taken by a node receiving a RosterUpdateIndication is described in 8.3.2.5. + +A node which is the Top GCC Provider having just entered a conference, and received a GCC-Conference-Announce-Presence request shall include the information contained in its Conference Roster database, but may wait until it has received any RosterUpdateIndication PDUs from at least one other node in the conference before transmitting any PDUs. On receiving such indication, it shall update its Conference and Application Roster database and then broadcast the full Conference and Application Rosters by sending a RosterUpdateIndication to all nodes in the conference. This is done by issuing an MCS-Uniform-Send-Data request, specifying the GCC-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. In the case of new nodes entering the conference, the RosterUpdateIndication is sent as a full refresh, including the Node Records from all nodes joined to the conference, as well as for each Application Protocol Session in the conference, a collapsed Application Capabilities List, and a list of Peer Application Protocol Entities which are part of that session along with the Application Record for each. The rules for generating the full Conference and Application Rosters, including the collapsed Application Capabilities List are described in 8.3.2.5. + +**Table 8-35 – RosterUpdateIndication GCCPDU** + +| Content | Source | Sink | +|------------------------------------|-----------------------------------------------------------------|--------------------------| +| Full Refresh Flag | Source GCC Provider | Destination GCC Provider | +| Conference Information (optional) | Source GCC Provider from information in Request or received PDU | Destination GCC Provider | +| Application Information (optional) | Source GCC Provider from information in Request or received PDU | Destination GCC Provider | + +#### 8.3.2.3 Enrolling Application Protocol Entities + +On receipt of a GCC-Application-Enroll request primitive, a GCC Provider shall first determine if there is already an existing entry in the Local Application Roster for the specified conference associated with the GCCSAP of the requester. If not, and if the Enroll/un-enroll flag in the request is set to Enroll, a new entry is created in the Local Application Roster containing the information specified in the request primitive. In this, case the GCC Provider shall also assign an Entity ID to the newly-enrolled Application Protocol Entity as described in 8.3.2.2. If the Enroll/un-enroll flag had been set to Un-enroll, the request is confirmed immediately by generating a GCC-Application-Enroll confirm and issuing it to the GCCSAP of the requester. In this case, no further action is taken. + +If the entry in the Local Application Roster already exists and the Enroll/un-enroll flag is set to Enroll, the contents of the existing entry are modified to reflect the new values specified. If the + +Enroll/un-enroll flag had been set to Un-enroll, the GCC Provider shall remove the corresponding entry from the Local Application Roster. + +If the GCC Provider is not the Top GCC Provider for the specified conference, the GCC Provider shall then send its new Local Application Roster to the node directly above it in the connection hierarchy, using a RosterUpdateIndication PDU. It shall do this by issuing an MCS-Send-Data request specifying the Node ID of the higher node as the Channel ID, specifying High data priority, and including the selected PDU in the Data field. The Node ID of the GCC Provider directly above in the connection hierarchy is determined at the time of connection to the conference from either the ConferenceCreateResponse, ConferenceJoinResponse, or ConferenceInviteRequest PDUs, depending on how the conference was joined. The content of the RosterUpdateIndication PDU is shown in Table 8-35. + +If the enroll had occurred prior to the initial transmission of a RosterUpdateIndication PDU, then the new or altered Record is included in the initial roster information, sent as a full refresh as described in 8.3.2.2. If an Application Protocol Entity un-enrolled prior to the initial transmission, its record entry is removed from the roster and never included in any transmitted PDU. + +If the enroll occurred after the initial transmission of a RosterUpdateIndication PDU, the new, modified, or removed Record is treated as an update to the existing roster. In this case, the GCC Provider may either choose to re-send its portion of the Conference and Application Rosters in their entirety, or it may send the information as an update – only sending information regarding the record that has changed. It is preferred that the latter method be used in order to minimize the size of the PDU, and therefore, its transmission time. If more than one change has been made (more than one GCC-Application-Enroll request had been received) since the last update, these changes may be concatenated into a single PDU. For a given Application Protocol Session, if only the Application Record information has changed since the last instance of that Application Protocol Session, the Application Capabilities List need not be included in the RosterUpdateIndication PDU, only the modified Application Record. For a given Application Protocol Session, the Application Capabilities List requires updating if its contents from an already enrolled Application Protocol Entity had been changed, or if a newly-enrolled Application Protocol Entity is part of the Application Protocol Session for which Peer Application Protocol Entities had already been enrolled at the local node or at nodes below the local node in the connection hierarchy, or if a node is un-enrolled in the case that there are other Peer Application Protocol Entities which remain enrolled at the local node or at nodes below the local node in the connection hierarchy. In the case where there is more than one Peer Application Protocol Entity either after an enroll, or before an un-enroll, the GCC Provider shall recreate the collapsed Application Capabilities List for that Application Protocol Session prior to including it in the RosterUpdateIndication PDU. This collapse shall be done by the procedure described in 8.3.4. + +Before sending the RosterUpdateIndication PDU, if the Active/Inactive flag for the enrolling Application Protocol Entity is set to Active, the GCC Provider shall examine the Conducting Operation Capable Flag. If this flag is set, the GCC Provider shall ensure that only one Peer Application Protocol Entity from this node for each Application Protocol Session is included in the Application Roster with this flag set. If no such Peer Application Protocol Entity has been chosen indicated in the Application Roster so far, the newly enrolling Application Protocol Entity may be included in the transmitted RosterUpdateIndication PDU with this flag set. If there has already been a Peer Application Protocol Entity at this node which has been included in the Application Roster with this flag set, the GCC Provider may either include the newly enrolling Application Protocol Entity in the RosterUpdateIndication PDU without this flag set, or it may include the newly enrolling Application Protocol Entity with this flag set, and the previous designated conducting-capable Application Protocol Entity with this flag now set to FALSE. The rule for choosing which Peer Application Protocol Entity to include in the Application Roster with this flag set is a local matter beyond the scope of this Recommendation. If the Active/Inactive flag for the enrolling Application Protocol Entity is set to Inactive, the Conducting Operation Capable Flag + +indicated in the request primitive shall be ignored, and the corresponding field in the updated roster shall be set to FALSE. + +In the case the Top GCC Provider, the successful change of an entry in the Local Application Roster results in a direct modification to the Conference Application Roster and the associated procedure for notification of all other nodes in the conference of the new Conference Application Roster as described in 8.3.2.5. + +In all of the successful cases, the GCC Provider shall generate a GCC-Application-Enroll confirm primitive indicating a successful result and issue it to the GCCSAP of the requester. + +#### **8.3.2.4 Updating a Conference Roster Entry** + +If a GCC-Conference-Announce-Presence request is received after having already transmitted an initial roster, the new Node Record contained in this request shall be treated as an update to the Conference Roster. As in the case of an updated Application Record, the GCC Provider shall then send its new Node Record to the node directly above it in the connection hierarchy, using a RosterUpdateIndication PDU. It shall do this by issuing an MCS-Send-Data request specifying Node ID of higher node as the Channel ID, specifying High data priority, and including the selected PDU in the Data field. The content of the RosterUpdateIndication PDU is shown in Table 8-35. + +As in the case of the enroll, the GCC Provider may either choose to re-send its portion of the Conference and Application Rosters in their entirety, or it may send only the new Node Record as an update. It is preferred that the later method be used in order to minimize the size of the PDU, and therefore, its transmission time. + +If a GCC provider receives an MCS-Detach-User indication for which the User ID is that of a locally enrolled Application Protocol Entity, it shall update the roster to remove that Application Protocol Entity, and it shall issue a GCC-Permission-To-Enroll indication primitive to the GCCSAP corresponding to that Application Protocol Entity. + +#### **8.3.2.5 Propagation of Roster Updates to the Top GCC Provider** + +On receipt of a RosterUpdateIndication PDU from a node directly below in the connection hierarchy, a GCC Provider shall first update its subset of the Conference and Application Rosters. Each node in the conference shall maintain that subset of the Conference and Application Rosters which corresponds to that node as well as all nodes below it in the connection hierarchy. For each Application Protocol Entity which has been enrolled at any of these nodes, a list of Application Records including the Node ID of the node to which that record corresponds, and a partially collapsed Application Capabilities List are maintained. This is the Application Capabilities List which corresponds to the outcome of the set of rules to be applied to the Application Capabilities Lists of the Nodes directly below this node in the connection hierarchy (which are themselves partially collapsed). + +The procedure that the GCC Provider shall use to update its roster subset depends on the update method used in the received RosterUpdateIndication. If the update was indicated to be a full refresh (as indicated by the full-refresh flag in the PDU), the following procedure is used. First, all Node Records and Application Records corresponding to the node from which the PDU was received, or nodes which were previously known to be below that node in the connection hierarchy are removed from the local subset of the Conference and Application Rosters. All Conference and Application Records listed in the PDU are then added to the roster. The entire Application Capabilities List, corresponding to the requesting node below, which may have been stored at this node is removed. The Application Capabilities List specified in the PDU replaces it. For all Application Protocol Entities either currently known to be enrolled at or below the current node, as well as any new Application Protocol Entities indicated in the newly received PDU (including ones not specified in this PDU), a new collapsed Application Capabilities List shall be computed from each of the + +Application Capabilities Lists from the nodes directly below. This collapse shall be done by the procedure described in 8.3.4. + +In the case that the RosterUpdateIndication did not indicate a full refresh, a slightly different procedure is followed. First, if the Node Record information was indicated as changed, if the change was done as a refresh of the list of Node Records, all Node Records corresponding to the node from which the PDU was received, or nodes which were previously known to be below that node in the connection hierarchy are removed from the local subset of the Conference Roster. All Node Records listed in the PDU are then added to the roster. If the change was done as a series of updates to Node Records, any records indicated as added are added to the roster subset, any indicated as replaced are used to replace the existing record, and any indicated for removal are removed. An attempt to change a record which already exists, or to modify or remove a record which does not exist is ignored. In any case, for any nodes which were previously in the roster subset and have been removed, all Application Records corresponding to those nodes are also removed (regardless of whether the corresponding update information was included in the Application Roster portion of the PDU). If any Application Record information was indicated as changed, for each Application Protocol Session, a similar procedure is followed. For each Application Protocol Session, if the change was done as a refresh, all Application Records corresponding to the node from which the PDU was received, or nodes which were previously known to be below that node in the connection hierarchy are removed from the local subset of the Application Roster. All Application Records listed in the PDU are then added to the roster. It is possible that for a given Application Protocol Session, it is indicated that there are no nodes which have that Application Protocol Entity enrolled. If the change was done as a series of updates to Application Records, any records indicated as added are added to the roster subset, any indicated as replaced are used to replace the existing record, and any indicated for removal are removed. An attempt to change a record which already exists, or to modify or remove a record which does not exist is ignored. For Application Capabilities List, the same procedure is followed as described for the full-refresh case. In this case, however, the new Application Capabilities Lists are only re-computed for sets of Peer Application Protocol Entities which have indicated a change. + +In either of the above cases, the updated information for the Conference Roster and for each Application Protocol Session in the Application Roster includes an instance number. If the conference information has changed due to the received update, the instance number for the conference information shall be incremented by one modulo $2^{16}$ . Similarly, for each Application Protocol Session for which any information was modified (either Application Records or the Application Capabilities List), this instance number shall be incremented by one modulo $2^{16}$ . If multiple changes are made to be forwarded to other nodes as a single update, these changes may be counted as a single increment to the instance number. The instance numbers are maintained locally and corresponds to its local subset of the roster. That is, that node plus the nodes located below it in the connection hierarchy. In the case of the Top GCC Provider, the instance numbers apply to the Conference and Application Rosters which are broadcast to all nodes and reported in the GCC-Application-Roster-Report primitive. The conference information also includes a flag indicating whether nodes have been added and/or removed since the last instance. Similarly, for each Application Protocol Session, a flag indicates whether nodes have been added and/or removed since the last instance of the information for that set of Application Protocol Entities. In this case, nodes being added or removed may indicate that an Application Protocol Entity has been enrolled or un-enrolled at a node, respectively, not necessarily that the entire node has been added or removed from the conference. + +Once the Conference and/or Application Roster information has been re-computed, a GCC Provider which is not the Top GCC Provider shall generate a RosterUpdateIndication PDU which shall then be sent to the GCC Provider directly above it in the connection hierarchy. The format of the information contained in this PDU may be either a full refresh, a refresh of some sets of Peer Application Protocol Entities and/or the conference information, or as individual updates. The + +choice of format to send the update information is left to the GCC Provider. It is preferred that a choice which minimizes the size of the PDU, and therefore minimizes transmission time, be used. + +#### **8.3.2.6 Distribution of the conference and application rosters** + +When the Top GCC Provider has received a RosterUpdateIndication, it shall modify the Conference and Application Roster information which it maintains (which, in this case, are the full Conference and Application Rosters rather than a subset) in a manner identical to that described for an intermediate MCU updating its subset of the roster. Once the complete roster has been updated, the Top GCC Provider shall broadcast the updated roster information to all nodes by sending a RosterUpdateIndication PDU. This is done by issuing an MCS-Uniform-Send-Data request specifying the GCC-Broadcast-Channel as the Channel-ID, specifying High data priority, and including the PDU in the Data field. + +If the case that the Conference Roster has been modified to include new nodes, the RosterUpdateIndication shall be broadcast as a full refresh. That is, the Conference and Application Rosters shall be transmitted in full to all nodes. In the case that a modification had been made to the roster which did not involve the addition of new nodes, the Top GCC Provider may choose to send the update either as a full refresh, or as a refresh to the list of Node Records, and/or the list of Application Records for some or all sets of Peer Application Protocol Entities, and/or the Application Capabilities List for some or all Application Protocol Sessions. + +On receipt of a RosterUpdateIndication on the GCC-Broadcast-Channel, each GCC Provider shall generate a GCC-Conference-Roster-Report indication and issue it to the Control GCCSAP if the received PDU indicated any change to the Conference Roster. If the received PDU had indicated a change to some or all of the Application Roster, the GCC Provider shall generate a series of GCC-Application-Roster-Report indications and issue them to the GCCSAP associated with each enrolled Application Protocol Entity corresponding to an Application Protocol Session for which an Application Roster update has been received in the PDU. It may also issue GCC-Application-Roster-Report indications to other GCCSAPs, although the need to do so is considered a local matter beyond the scope of this Recommendation. Only that portion of the Conference Application Roster associated with the Session Key for that Application Protocol Entity must be included in the corresponding primitive. The GCC Provider may choose to include portions of the roster corresponding to other Session Keys, although the need to do this is considered a local matter beyond the scope of this Recommendation. In the case of an Application Protocol Entity enrolled inactively with no Session ID, the GCC Provider shall issue a GCC-Application-Roster-Report indication to the corresponding GCCSAP for portions of the roster corresponding to any Application Protocol Session with the same base Application Protocol as the Application Protocol Entity. The GCC Provider shall also issue a GCC-Application-Roster-Report indication to the Control GCCSAP, including Application Roster updates for all sets of Peer Application Protocol Entities which have been indicated as changed by the received PDU. + +#### **8.3.2.7 Nodes leaving a conference** + +On receiving an MCS-Detach-User indication, MCU nodes which have nodes below them in the connection hierarchy shall check the User ID indicated and determine if it corresponds to the Node ID of a node directly below it in the connection hierarchy. If so, it shall remove all entries corresponding to this node, as well as any nodes known to be connected below that node, from its subset of the Conference and Application Rosters. It shall then re-compute the Application Capabilities Lists for all sets of Peer Application Protocol Entities in the manner described in 8.3.4. Once the roster subset has been fully updated to reflect the leaving node, that GCC Provider shall follow the procedure described in 8.3.2.5 to propagate this update to the other nodes in the conference. + +At a node which has disconnected from a conference (via either disconnection, termination of the conference, or ejection from the conference), the GCC Provider shall generate a GCC-Permission- + +To-Enroll indication which revokes permission to enroll in the corresponding conference. It shall issue this to all non-Control GCCSAPs. + +#### **8.3.2.8 An example of a roster update** + +Figure 8-5 shows an example of a GCC-Application-Enroll request issued during a conference causing an update of the Conference Application Roster. In this example, the node is in the third layer of the connection hierarchy. It issues the update indication to the next higher node which then formats and sends an update indication to the next higher node, which in this example, is the top node in the hierarchy. The top node assembles the full Application Roster and broadcasts the portions associated with the updated Application Protocol Session to all nodes in the conference, resulting in GCC-Application-Report primitives being issued at all nodes to the Node Controller, and if present, the Peer Application Protocol Entities. + +![Sequence diagram showing the process of updating the Application Roster across three nodes: Updating Node, Next Higher Node, and Top Node, and then propagating the update to all nodes.](beda549cc2a4e2b9ac7f74fe9ed72b67_img.jpg) + +``` + +sequenceDiagram + participant UN as Updating Node + participant NHN as Next Higher Node + participant TN as Top Node + participant AN as All Nodes + + UN -->> UN : GCC-Application-Enroll.request + UN -->> UN : MCS-Send-Data.request + UN -->> UN : GCC-Application-Enroll.confirm + UN -.->> NHN : RosterUpdateIndication + + NHN -->> NHN : MCS-Send-Data.indication + NHN -->> NHN : MCS-Send-Data.request + NHN -.->> TN : RosterUpdateIndication + + TN -->> TN : MCS-Send-Data.indication + TN -->> TN : MCS-Uniform-Send-Data.request + TN -.->> AN : RosterUpdateIndication + + AN -->> AN : MCS-Uniform-Send-Data.indication + AN -->> AN : GCC-Application-Roster-Report.indication + + TN -->> TN : GCC-Application-Roster-Report.indication + TN -->> TN : Node Controller + +``` + +The diagram illustrates the sequence of messages for updating the Application Roster across a network hierarchy. It involves four main sections: Updating Node, Next Higher Node, Top Node, and All Nodes. + +- Updating Node:** Contains Client Application, GCC Provider, and MCS Provider. The sequence starts with a self-call for `GCC-Application-Enroll.request`, followed by `MCS-Send-Data.request`, and then `GCC-Application-Enroll.confirm`. A dashed arrow labeled `RosterUpdateIndication` is sent to the Next Higher Node. +- Next Higher Node:** Contains MCS Provider, GCC Provider, and MCS Provider. It receives the `RosterUpdateIndication` and performs a self-call for `MCS-Send-Data.indication`, followed by `MCS-Send-Data.request`. A dashed arrow labeled `RosterUpdateIndication` is sent to the Top Node. +- Top Node:** Contains MCS Provider, Top GCC Provider, and Node Controller. It receives the `RosterUpdateIndication` and performs a self-call for `MCS-Send-Data.indication`, followed by `MCS-Uniform-Send-Data.request`. A dashed arrow labeled `RosterUpdateIndication` is sent to the All Nodes section. +- All Nodes:** Contains Node Controller and Client App. Provider, GCC Provider, and MCS Provider. It receives the `RosterUpdateIndication` and performs a self-call for `MCS-Uniform-Send-Data.indication`, followed by `GCC-Application-Roster-Report.indication`. The Top Node also performs a self-call for `GCC-Application-Roster-Report.indication` and sends a message to the Node Controller. + +T.124(01-07)\_F8-05 + +Sequence diagram showing the process of updating the Application Roster across three nodes: Updating Node, Next Higher Node, and Top Node, and then propagating the update to all nodes. + +**Figure 8-5 – An example of updating the Application Roster** + +### 8.3.3 Scalable Roster Protocol + +The Scalable Roster Protocol was introduced to support various levels of scalability within a conference. The protocol relies on the use of Roster deltas instead of Full Roster Refreshes (which the Original Roster Protocol relied on) to exchange the most dynamically changing roster information. The protocol also relies on the use of Node Categories. The protocol specifies a markedly different behaviour depending on a node's assigned Node Category. The subclauses below describe the Scalable Roster protocol in detail. + +#### 8.3.3.1 Overview + +Both the Conference and Application Rosters are communicated among nodes using the same set of PDUs. The RosterUpdateIndication PDU is used to send complete or partial roster information to other nodes in the conference. In addition, the RosterRefreshRequest PDU is used to make requests for a full refresh of a Conference and/or Application roster from a Parent node. + +When each node (other than the top node) first announces its roster information upon joining a conference, the node sends a RosterUpdateIndication to the node directly above it in the hierarchy. This is the case for all three Node Categories. Subsequent updates to any portion of either the Conference or Application Roster information are announced by reissuing a RosterUpdateIndication containing the new information. + +When a node updates its portion of the roster (or announces it for the first time), that information is propagated from node-to-node up the connection hierarchy until it reaches the Top GCC Provider. The Top Provider is responsible for forming the full Conference and Application rosters and then distributing deltas of the rosters to all nodes in the conference. Whether or not a node is added to the roster depends on the Node Category of the node joining the conference. For instance, Conventional nodes will always be added to the roster while Anonymous nodes are never added. Counted nodes are only added to rosters maintained by Conventional nodes. + +If the roster information propagating up the connection hierarchy is associated with a Conventional node, each intermediate node (MCU) is responsible for forming a subset of the full Conference and Application Rosters by storing this node's roster information. The Conference Roster is a subset that includes Node Records for the receiving node and all other Conventional nodes below it in the connection hierarchy. The Application Roster includes a separate list of Application Records for each Application Protocol Session in existence (at a Conventional Node) at or below the node that receives the roster update. It also includes the Application Capabilities List for these sessions. On receiving a RosterUpdateIndication from a Conventional node below, an intermediate node makes the appropriate changes to its subset of its rosters, then passes the roster update up to the next higher node by issuing a RosterUpdateIndication. Note that regardless of Node Category, the RosterUpdateIndication is always forwarded. The only difference here is that Counted and Anonymous nodes are not maintained in the roster subsets held at intermediate nodes. + +The primary reason for maintaining subsets of roster information at intermediate nodes is to maintain the collapsed set of capabilities. Since Counted and Anonymous nodes do not affect capabilities, there is no need to maintain their records in the roster subsets. If an update from a lower Conventional node included a change that caused the Application Capabilities Lists for at least one Application Protocol Session to have to be recomputed, the new roster information for the roster subset can only be generated if the individual Application Capabilities Lists for each Conventional node directly below it in the connection hierarchy is known (to allow the collapse rules to be reapplied with the new updated information). The GCC Provider at each node shall maintain this information locally. + +When a roster update associated with a Conventional node reaches the Top GCC Provider, it shall then broadcast the new roster information to all nodes in the conference (including Counted and Anonymous nodes). This is done by broadcasting only the delta information in a + +RosterUpdateIndication PDU to all nodes. If the roster update information that reaches the Top GCC Provider is associated with a Counted node, a delta update is broadcasted to both the Conventional nodes participating in the conference and to the joining Counted node that initiated the original roster update. No other Counted or Anonymous nodes will receive a roster update when this occurs. Anonymous node updates received at the Top GCC Provider do not cause an update to be broadcasted. Instead, the local Top GCC Provider may maintain a separate list of Anonymous nodes that are currently listening in (or have listened in) on the conference for informational or statistical purposes (this is up to the local implementation). + +Roster information sent using the RosterUpdateIndication PDU may be sent in one of three ways. The roster may be sent as a refresh of the full Conference and Application Rosters, replacing all existing roster entries. Alternatively, portions of the roster may be sent so that the Conference Roster and/or portions of the Application Roster associated with one or more Session Keys may be refreshed. In this case, all entries in the transmitted portion of the roster are replaced, but portions that are not sent are left unchanged. Finally, changes to portions of the roster may be sent as updates so that only those particular elements of the roster (e.g., individual Application Records) which have been added, modified, or removed are sent and all other entries are left unchanged. + +Since only delta RosterUpdateIndication PDUs are ever broadcasted from the Top Provider, the burden of assimilating a complete Conference or Application Roster is placed on the joining node and its Parent node. To do this, the joining node forwards a RosterRefreshRequest PDU to its Parent node requesting a Full Roster Refresh. The point at which this request is issued depends on the joining node's Node Category. For Conventional and Counted nodes, this request is issued after it receives a roster update from the Top Provider for itself (which ensures that its presence in the conference is known). For Anonymous nodes, the request can be made immediately following the reception of its Parent node's User ID. + +After the RosterRefreshRequest PDU is received by the Parent node, it must either process the request (if it has access to the requested rosters) or it must forward the request up to the next node in the connection hierarchy. When a node is reached that contains the requested information, that node directs a RosterUpdateIndication containing a Full Roster Refresh directly to the requesting node. Note that the response to a RosterRefreshRequest will look different depending on the Node Category to which the requesting node belongs. For instance, if a Conventional node initiated the request, a full refresh which contains both Conventional and Counted nodes must be delivered. Therefore, a Conventional Parent node must be reached before the request can be processed (because only Conventional nodes maintain a list of Counted nodes). If the requesting node is either Anonymous or Counted, the request can be handled by the first node that contains the Conventional node roster. + +It is necessary for joining nodes to buffer incoming RosterUpdateIndications received from the Top GCC Provider prior to receiving the response from their initial RosterRefreshRequest. This is necessary to ensure that no updates get lost which guarantee the synchronization of all Rosters in the conference. All RosterUpdateIndications include an instance number that is sequentially incremented every time the Top Provider detects that a roster changed. This roster instance number is used to determine the order that RosterUpdateIndications should be processed at a joining node. This can be especially complicated for Conventional nodes that are participating in a conference which can include both Conventional and Counted nodes. This is because RosterUpdateIndications will be received on both the GCC-Conventional-Broadcast-Channel and the GCC-Counted-Broadcast-Channel. It is up to the Conventional node to process the RosterUpdateIndications in the correct order based on its prior knowledge that the roster instance numbers are incremented sequentially. + +#### **8.3.3.2 Nodes entering a conference** + +When a node is joined to a conference, either via a conference creation, join, or invitation, a GCC Provider shall issue a GCC-Application-Permission-To-Enroll indication to the GCCSAP for all + +Application Protocol Entities (APEs) that have locally indicated their presence to the GCC Provider. In the case that a GCC Provider becomes aware of an additional Application Protocol Entity while it is already joined to a conference, the GCC Provider shall issue a GCC-Application-Permission-To-Enroll indication to the corresponding GCCSAP to indicate the existence of this conference. The Application Protocol Entity is informed of its Node Category through the GCC-Application-Permission-To-Enroll. + +Before taking any further action, the GCC Provider shall wait until it has received a GCC-Conference-Announce-Presence request from the Control GCCSAP as well as a GCC-Application-Enroll request from all Application Protocol Entities which have been sent GCC-Application-Permission-To-Enroll indications. Some of these enroll requests may indicate that that Application Protocol Entity does not intend to enroll (the enroll/un-enroll flag is set to un-enroll). For each received GCC-Application-Enroll request with the enroll flag set, the information provided in the primitive for that Application Protocol Entity is added to the Local Application Roster. + +The GCC Provider shall also assign a locally allocated Entity ID to each enrolled Application Protocol Entity. This shall be used by the GCC Provider as an identifier of each corresponding Application Protocol Entity in the RosterUpdateIndication PDU. The assigned Application Protocol Entity ID is also included in the GCC-Application-Enroll confirm primitive that is returned to each enrolling Application Protocol Entity along with the Node ID of the local node. The Entity ID is a 16-bit integer value that is to be unique among all Application Protocol Entities enrolled at a node. If an Application Protocol Entity un-enrolls, the value of its Entity ID shall not be re-used unless all other values not assigned to an Application Protocol Entity at the time of the un-enroll have been assigned. + +The GCC Provider shall examine the Conducting Operation Capable Flag of each enrolled Application Protocol Entity with the Active/Inactive flag set to Active (inactive Application Protocol Entities are assumed not to be capable of conducting operation). If there is more than one such enrolled Application Protocol Entity with this flag set, the GCC Provider shall select one of them for which to set this flag in the Application Roster information. This information is to be sent in the RosterUpdateIndication PDU. The rule for which of these to select is a local matter not specified in this Recommendation. A typical rule may be to select the first such Application Protocol Entity that enrolls. + +Depending on a node's Node Category, the local GCC Provider must determine the proper course of action to take after receiving the GCC-Conference-Announce-Presence request from the Control GCCSAP and a GCC-Application-Enroll request from all Application Protocol Entities. Since only Conventional nodes are allowed to create application sessions, GCC providers at Counted and Anonymous nodes must hold back any RosterUpdateIndication information associated with non-existing APE sessions until a RosterUpdateIndication PDU is received from a node above. The above node notifies that the session being enrolled with actually exists. The local GCC Providers at Counted and Anonymous nodes can also use the Application Protocol Keys received in the initial enrolments to determine local interest in incoming RosterUpdateIndications. For instance, any time a local GCC Provider is informed of a new session through a RosterUpdateIndication received from either the Top Provider or its Parent node, it must decide which APEs are interested in the occurrence. The local provider uses the Application Protocol Key associated with the new session to decide which APEs to send a Roster Update Indication to. Detailed procedures are described below for each Node Category. + +A GCC Provider at a Conventional node that is not the Top GCC Provider shall send a RosterUpdateIndication to the GCC Provider directly above it in the connection hierarchy upon receiving the GCC-Conference-Announce-Presence request from the Control GCCSAP and a GCC-Application-Enroll request from all Application Protocol Entities. This is done by issuing an MCS-Send-Data request specifying the Node ID of the destination node as the Channel ID, + +specifying High data priority, and including the PDU in the Data field. The Node ID of the node directly above in the connection hierarchy is determined at the time of connection to the conference from either the ConferenceCreateResponse, ConferenceJoinResponse, or ConferenceInviteRequest PDUs, depending on how the conference was joined. The value of the Node ID of the above node shall also be included in the conference roster portion of the PDU as the Superior Node parameter. The content of the RosterUpdateIndication PDU is shown in Table 8-35. In this case, the roster is sent as a full refresh, including the local Node Record, as well as the Application Records for all enrolled Application Protocol Entities and the Application Capabilities Lists for all Application Protocol Sessions corresponding to enrolled Application Protocol Entities. If there had been more than one Application Protocol Entity locally enrolled for a given Application Protocol Session, the GCC Provider shall perform a collapse of the Application Capabilities List among the Peer Application Protocol Entities. This would produce the Application Capabilities List that is to be included in the RosterUpdateIndication PDU for that Application Protocol Session. This collapse shall be done by the procedure described in 8.3.4. + +A GCC Provider at a Counted node shall send a RosterUpdateIndication to the GCC Provider directly above it in the connection hierarchy upon receiving the GCC-Conference-Announce-Presence request from the Control GCCSAP and a GCC-Application-Enroll request from all Application Protocol Entities. This is done by issuing an MCS-Send-Data request specifying the Node ID of the destination node as the Channel ID, specifying High data priority, and including the PDU in the Data field. The value of the Node ID of the above node shall again be included in the conference roster portion of the PDU as the Superior Node parameter. In this case, only the local Node Record is sent. The Application Records are held back until the local GCC Provider receives a RosterUpdateIndication from an above node informing it that the locally enrolled sessions actually exist. + +A GCC Provider at an Anonymous node shall send a RosterUpdateIndication to the GCC Provider directly above it in the connection hierarchy upon receiving the GCC-Conference-Announce-Presence request from the Control GCCSAP and a GCC-Application-Enroll request from all Application Protocol Entities. This is done by issuing an MCS-Send-Data request specifying the Node ID of the destination node as the Channel ID, specifying High data priority, and including the PDU in the Data field. The value of the Node ID of the above node shall again be included in the conference roster portion of the PDU as the Superior Node parameter. Again, only the local Node Record is sent. Note that this RosterUpdateIndication is used only for informational purposes and does not affect the Conference Roster. An Anonymous node will never send a RosterUpdateIndication that includes roster information associated with an Application Protocol Entity. An Anonymous node should also never send more than a single RosterUpdateIndication. + +A node that is the Top GCC Provider and just entered a conference, and that received a GCC-Conference-Announce-Presence request, shall include the information contained in its Conference Roster database. But the node may wait until it has received any RosterUpdateIndication PDUs from at least one other node in the conference before transmitting any PDUs. If an indication is received from a Conventional node, it shall update its Conference and Application Roster database, then broadcast back out the roster information associated with the update indication by sending a RosterUpdateIndication to all nodes in the conference. This is done by issuing an MCS-Send-Data request, specifying the GCC-Conventional-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. Updates sent from the Top GCC Provider to every node in the conference because of a newly joining node are never sent as a full refresh, which holds down the network traffic incurred by adding new nodes to a conference. + +#### **8.3.3.3 Enrolling Application Protocol Entities** + +On receiving a GCC-Application-Enroll request primitive, a GCC Provider shall first determine if there is already an existing entry in the Local Application Roster for the specified conference + +associated with the GCCSAP of the requester. If not, and if the Enroll/Un-enroll flag in the request is set to Enroll, a new entry is created in the Local Application Roster that contains the information specified in the request primitive. In this case, the GCC Provider shall also assign an Entity ID to the newly enrolled Application Protocol Entity as described in 8.3.3.2. If the Enroll/Un-enroll flag had been set to Un-enroll, the request is confirmed immediately by generating a GCC-Application-Enroll confirm and issuing it to the GCCSAP of the requester. In this case, no further action is taken. + +If the entry in the Local Application Roster already exists and the Enroll/Un-enroll flag is set to Enroll, the contents of the existing entry are modified to reflect the new values specified. If the Enroll/Un-enroll flag had been set to Un-enroll, the GCC Provider shall remove the corresponding entry from the Local Application Roster. + +If the GCC Provider is not the Top GCC Provider for the specified conference and is a Conventional node, the GCC Provider shall then send its new Local Application Roster to the node directly above it in the connection hierarchy, using a RosterUpdateIndication PDU. The GCC Provider shall do this by issuing an MCS-Send-Data request specifying the Node ID of the higher node as the Channel ID, specifying High data priority, and including the selected PDU in the Data field. The Node ID of the GCC Provider directly above it in the connection hierarchy is determined at the time of connection to the conference from either the ConferenceCreateResponse, ConferenceJoinResponse, or ConferenceInviteRequest PDUs, depending on how the conference was joined. The content of the RosterUpdateIndication PDU is shown in Table 8-35. + +If the GCC Provider is a Counted node, the procedure is a bit more complicated. Before sending its new Local Application Roster to the node directly above it in the connection hierarchy, the local GCC Provider must determine if the sessions associated with each enroll request actually exist. Only the enroll requests that correspond to sessions that exist will be forwarded. This is due to the requirement that Counted nodes are not allowed to create sessions. The local GCC Provider is made aware of new sessions in one of two ways: either through a RosterUpdateIndication PDU received from the Top Provider or through a response to a RosterRefreshRequest received from a Parent node. Once it has been determined which enroll requests are associated with existing sessions, the GCC Provider will send a RosterUpdateIndication PDU containing the appropriate Application Records to the node directly above it in the connection hierarchy. The GCC Provider shall do this by issuing an MCS-Send-Data request specifying the Node ID of the higher node as the Channel ID, specifying High data priority, and including the selected PDU in the Data field. RosterUpdateIndications sent from a Counted node should never include capability information since a Counted node cannot affect the collapsed capability list. Each APE must make a decision on whether or not it can support the established capabilities within a conference. + +If the GCC Provider is an Anonymous node, the local GCC Provider simply stores the information in its Local Application Roster and uses it to determine the Application Protocol Sessions that a particular GCC Service Access Point (SAP) is interested in. No APE information will ever be sent from an Anonymous node inside a RosterUpdateIndication. It is important that the local GCC Provider maintains this information base so that it can relay all information about new or changing Application Rosters to the appropriate SAPs. This guarantees that all the APEs running on an Anonymous node have access to all the information necessary to join and listen in on a particular session. + +In general, if the enroll had occurred prior to the initial transmission of a RosterUpdateIndication PDU, then the new or altered Record is included in the initial roster information, sent as a full refresh as described in 8.3.3.2. If an Application Protocol Entity un-enrolled prior to the initial transmission, its record entry is removed from the roster and is never included in any transmitted PDU. + +If the enroll occurred after the initial transmission of a RosterUpdateIndication PDU, the new, modified, or removed Record is treated as an update to the existing roster. In this case, the GCC + +Provider may either choose to resend its portion of the Conference and Application Rosters in their entirety, or the GCC Provider may send the information as an update – only sending information regarding the record that has changed. It is preferred that the latter method be used in order to minimize the size of the PDU and, therefore, its transmission time. If more than one change has been made (more than one GCC-Application-Enroll request had been received) since the last update, these changes may be concatenated into a single PDU. For a given Application Protocol Session, if only the Application Record information has changed since the last instance of that Application Protocol Session, the Application Capabilities List need not be included in the RosterUpdateIndication PDU, only the modified Application Record. For a given Application Protocol Session at a Conventional node, the Application Capabilities List requires updating if any of the following occur: + +- Its contents from an already enrolled Application Protocol Entity had been changed. +- A newly-enrolled Application Protocol Entity is part of the Application Protocol Session for which Peer Application Protocol Entities had already been enrolled at the local node or at nodes below the local node in the connection hierarchy. +- A node is un-enrolled in the case that there are other Peer Application Protocol Entities that remain enrolled at the local node or at nodes below the local node in the connection hierarchy. + +In the case where there is more than one Peer Application Protocol Entity either after an enroll or before an un-enroll, the GCC Provider at a Conventional node shall re-create the collapsed Application Capabilities List for that Application Protocol Session prior to including it in the RosterUpdateIndication PDU. This collapse shall be done by the procedure described in 8.3.4. + +If the Active/Inactive flag for the enrolling Application Protocol Entity is set to Active before sending the RosterUpdateIndication PDU, the GCC Provider shall examine the Conducting Operation Capable Flag. If this flag is set, the GCC Provider shall ensure that only one Peer Application Protocol Entity from this node for each Application Protocol Session is included in the Application Roster with this flag set. If no such Peer Application Protocol Entity has been selected in the Application Roster so far, the newly enrolling Application Protocol Entity may be included in the transmitted RosterUpdateIndication PDU with this flag set. If there has already been a Peer Application Protocol Entity at this node, which has been included in the Application Roster with this flag set, the GCC Provider may either: + +- Include the newly enrolling Application Protocol Entity in the RosterUpdateIndication PDU without this flag set. +- Include the newly enrolling Application Protocol Entity with this flag set, and the previous designated conducting-capable Application Protocol Entity with this flag now set to FALSE. + +The rule for selecting which Peer Application Protocol Entity to include in the Application Roster with this flag set is a local matter beyond the scope of this Recommendation. If the Active/Inactive flag for the enrolling Application Protocol Entity is set to Inactive, the Conducting Operation Capable Flag indicated in the request primitive shall be ignored, and the corresponding field in the updated roster shall be set to FALSE. The Conducting Operation Capable Flag should always be set to FALSE for APEs residing on Conducted and Anonymous nodes. + +In the case of the Top GCC Provider, the successful change of an entry in the Local Application Roster results in a direct modification to the Conference Application Roster and the associated procedure for notifying all other nodes in the conference of the new Conference Application Roster as described in 8.3.3.6. + +In all of the successful cases, the GCC Provider shall generate a GCC-Application-Enroll confirm primitive indicating a successful result. The GCC Provider shall issue it to the GCCSAP of the requester. + +#### **8.3.3.4 Updating a Conference Roster Entry** + +If a GCC-Conference-Announce-Presence request is received after having already transmitted an initial roster, the new Node Record contained in this request shall be treated as an update to the Conference Roster. As in the case of an updated Application Record, the GCC Provider shall then send its new Node Record to the node directly above it in the connection hierarchy by using a RosterUpdateIndication PDU. The GCC Provider shall do this by issuing an MCS-Send-Data request specifying the Node ID of the higher node as the Channel ID, specifying High data priority, and including the selected PDU in the Data field. The content of the RosterUpdateIndication PDU is shown in Table 8-35. Note that a GCC-Conference-Announce-Presence request should never be received after having already transmitted an initial roster from Anonymous nodes. + +If a GCC Provider receives an MCS-Detach-User indication for which the User ID is that of a locally-enrolled Application Protocol Entity, the GCC Provider shall update the roster to remove that Application Protocol Entity and it shall also issue a GCC-Permission-To-Enroll indication primitive to the GCCSAP corresponding to that Application Protocol Entity. + +#### **8.3.3.5 Propagation of Roster Updates to the Top GCC Provider** + +On receiving a RosterUpdateIndication PDU from a node directly below in the connection hierarchy, a GCC Provider shall first update its subset of the Conference and Application Rosters. Each node in the conference shall maintain this subset of the Conference and Application Rosters that corresponds to that node as well as all nodes below it in the connection hierarchy. This subset should never include either Node Records or Application Records associated with Anonymous nodes. Each Node Record contains a flag that indicates a node's Node Category. + +For each Application Protocol Entity that has been enrolled at any of these nodes, a list of Application Records, including the Node ID of the node to which that record corresponds and a partially-collapsed Application Capabilities List, are maintained. This is the Application Capabilities List that corresponds to the outcome of the set of rules to be applied to the Application Capabilities Lists of the Nodes directly below this node in the connection hierarchy (which are themselves partially collapsed). + +The procedure that the GCC Provider shall use to update its roster subset depends on the update method used in the received RosterUpdateIndication. If the update was indicated to be a full refresh (as indicated by the Full-Refresh flag in the PDU), the following procedure is used. First, all Node Records and Application Records corresponding to the node from which the PDU was received, or nodes which were previously known to be below that node in the connection hierarchy are removed from the local subset of the Conference and Application Rosters. All Conference and Application Records listed in the PDU are then added to the roster. The entire Application Capabilities List corresponding to the requesting node below, which may have been stored at this node, is removed. The Application Capabilities List specified in the PDU replaces it. For all Application Protocol Entities, either currently known to be enrolled at or below the current node, as well as any new Application Protocol Entities indicated in the newly-received PDU (including ones not specified in this PDU), a new collapsed Application Capabilities List shall be computed from each of the Application Capabilities Lists from the nodes directly below. This collapse shall be done by the procedure described in 8.3.4. + +In the case that the RosterUpdateIndication did not indicate a full refresh, a slightly different procedure is followed. First, if the Node Record information was indicated as changed and the change was done as a refresh of the list of Node Records, all Node Records corresponding to the node from which the PDU was received (or nodes which were previously known to be below that node in the connection hierarchy) are removed from the local subset of the Conference Roster. All Node Records listed in the PDU are then added to the roster. If the change was done as a series of updates to Node Records, any records indicated as added are added to the roster subset; any records indicated as replaced are used to replace the existing records; and any records indicated for removal + +are removed. An attempt to change a record which already exists, or to modify or remove a record which does not exist, is ignored. In any case, for any nodes which were previously in the roster subset and have been removed, all Application Records corresponding to those nodes are also removed (regardless of whether the corresponding update information was included in the Application Roster portion of the PDU). If any Application Record information was indicated as changed, for each Application Protocol Session, a similar procedure is followed. For each Application Protocol Session, if the change was done as a refresh, all Application Records corresponding to the node from which the PDU was received (or nodes which were previously known to be below that node in the connection hierarchy) are removed from the local subset of the Application Roster. All Application Records listed in the PDU are then added to the roster. It is possible that for a given Application Protocol Session, it is indicated that there are no nodes which have that Application Protocol Entity enrolled. If the change was done as a series of updates to Application Records, any records indicated as added are added to the roster subset; any records indicated as replaced are used to replace the existing record; and any records indicated for removal are removed. An attempt to change a record that already exists, or to modify or remove a record which does not exist, is ignored. For Application Capabilities List, the same procedure is followed as described for the full refresh case. In this case, however, the new Application Capabilities Lists are only recomputed for sets of Peer Application Protocol Entities that have indicated a change. + +In either of the above cases, the updated information for the Conference Roster and for each Application Protocol Session in the Application Roster includes an instance number. If the conference information has changed due to the received update, the instance number for the conference information shall be incremented by one modulo $2^{16}$ . Similarly, for each Application Protocol Session for which any information was modified (either Application Records or the Application Capabilities List), this instance number shall be incremented by one modulo $2^{16}$ . If multiple changes are made to be forwarded to other nodes as a single update, these changes may be counted as a single increment to the instance number. The instance numbers are maintained locally and correspond to the local subset of the roster. That is, that node plus the nodes located below it in the connection hierarchy. In the case of the Top GCC Provider, the instance numbers apply to the Conference and Application Rosters which are broadcast to all nodes and reported in the GCC-Application-Roster-Report primitive. The conference information also includes a flag indicating whether nodes have been added and/or removed since the last instance. Similarly, for each Application Protocol Session, a flag indicates whether nodes have been added and/or removed since the last instance of the information for that set of Application Protocol Entities. In this case, nodes being added or removed may indicate that an Application Protocol Entity has been enrolled or un-enrolled at a node, respectively, and not necessarily that the entire node has been added or removed from the conference. + +Once the Conference and/or Application Roster information has been recomputed, a GCC Provider, which is not the Top GCC Provider, shall generate a RosterUpdateIndication PDU that shall then be sent to the GCC Provider directly above it in the connection hierarchy. The format of the information contained in this PDU may be either a full refresh, a refresh of some sets of Peer Application Protocol Entities and/or the conference information, or individual updates. The format selection for sending the update information is left to the GCC Provider. It is preferred that the GCC Provider select a format that minimizes the size of the PDU and, therefore, minimizes transmission time used. + +#### **8.3.3.6 Distribution of the Conference and Application Rosters** + +When the Top GCC Provider has received a RosterUpdateIndication that includes either Conventional or Counted node roster information, it shall modify the Conference and Application Roster information which it maintains (which, in this case, are the full Conference and Application Rosters rather than a subset) in a manner identical to that described for an intermediate MCU updating its subset of the roster. Once the complete roster has been updated, the Top GCC Provider + +shall broadcast the updated roster information back to either every node in the conference or to the Conventional nodes participating in the conference. The choice depends on the roster information that was affected due to the received RosterUpdateIndication. Any changes to either the list of Conventional Node Records, the Application Roster due to an APE associated with a Conventional node, or to a Capability list, are transmitted to every node in the conference. This is done by issuing an MCS-Send-Data request specifying the GCC-Conventional-Broadcast-Channel as the Channel-ID, specifying High data priority, and including the PDU in the Data field. Changes to either the list of Counted Node Records or to an Application Roster due to an APE associated with a Counted node are transmitted only to Conventional nodes. This is done by issuing an MCS-Send-Data request specifying the GCC-Counted-Broadcast-Channel as the Channel-ID, specifying High data priority, and including the PDU in the Data field. + +The RosterUpdateIndication broadcasted from the Top GCC Provider includes only the specific roster information that changed due to the original RosterUpdateIndication received. This could include any or all of the following: one or more Node Records, one or more Application Records, and any list of Application Capabilities that may have been altered due to processing the received RosterUpdateIndication. This should not contain information that has already been broadcasted to the rest of the conference and this should not be a full refresh. + +On receiving a RosterUpdateIndication on either the GCC-Conventional-Broadcast-Channel or the GCC-Counted-Broadcast-Channel, each GCC Provider shall generate a GCC-Conference-Roster-Report indication and issue it to the Control GCCSAP if the received PDU indicated any change to the Conference Roster. If the received PDU had indicated a change to some or all of the Application Roster, the GCC Provider shall generate a series of GCC-Application-Roster-Report indications. The GCC Provider shall then issue them to the GCCSAP associated with each enrolled Application Protocol Entity that corresponds to an Application Protocol Session for which an Application Roster update has been received in the PDU. The GCC Provider may also issue GCC-Application-Roster-Report indications to other GCCSAPs, although the need to do so is considered a local matter beyond the scope of this Recommendation. Only that portion of the Conference Application Roster associated with the Session Key for that Application Protocol Entity must be included in the corresponding primitive. The GCC Provider may choose to include portions of the roster corresponding to other Session Keys, although the need to do this is considered a local matter beyond the scope of this Recommendation. In the case of an Application Protocol Entity enrolled inactively with no Session ID, the GCC Provider shall issue a GCC-Application-Roster-Report indication to the corresponding GCCSAP for portions of the roster corresponding to any Application Protocol Session with the same base Application Protocol as the Application Protocol Entity. The GCC Provider shall also issue a GCC-Application-Roster-Report indication to the Control GCCSAP, including Application Roster updates for all sets of Peer Application Protocol Entities which have been indicated as changed by the received PDU. + +#### **8.3.3.7 Nodes leaving a conference** + +On receiving an MCS-Detach-User indication, MCU nodes that have nodes below them in the connection hierarchy shall check the User ID indicated and determine if it corresponds to the Node ID of a node directly below it in the connection hierarchy. If so, the MCU node shall remove all entries corresponding to this node, as well as any nodes known to be connected below that node, from its subset of the Conference and Application Rosters. It shall then recompute the Application Capabilities Lists for all sets of Peer Application Protocol Entities in the manner described in 8.3.4. Once the roster subset has been fully updated to reflect the leaving node, that GCC Provider shall follow the procedure described in 8.3.3.6 to propagate this update to the other nodes in the conference. + +At a node which has disconnected from a conference (via either disconnection, termination of the conference, or ejection from the conference), the GCC Provider shall generate a GCC-Permission- + +To-Enroll indication which revokes permission to enroll in the corresponding conference. The GCC Provider shall issue this to all non-Control GCCSAPs. + +Node or Application records associated with Node IDs of Anonymous nodes should not appear in any node's Conference or Application Roster and can therefore be ignored. + +#### **8.3.3.8 Acquiring a Full Roster Refresh from a Parent Node** + +At any time during a conference, a node may request a Full Roster Refresh from its Parent node by making a RosterRefreshRequest to its Parent Node. A node does this by issuing an MCS-Send-Data request specifying the Node ID of the Parent node as the Channel ID, specifying High data priority, and including the RosterRefreshRequest PDU in the Data field. + +Typically, a RosterRefreshRequest would be made under the following conditions: either the node has just joined the conference and needs a Full Roster Refresh to synch up its Conference Application Roster to other nodes in the conference, or a Roster Inquire was received by a GCC Provider at an Anonymous node that is not maintaining a local copy of the Conference Application Roster. In either case, after the RosterRefreshRequest PDU is received by the Parent node, it must either process the request (if it has access to the requested rosters), or it must forward the request up to the next node in the connection hierarchy using another RosterRefreshRequest. + +When a node is reached that contains the requested information, that node directs a RosterUpdateIndication containing a Full Roster Refresh directly to the requesting node. A node does this by issuing an MCS-Send-Data request that specifies the Node ID of the originating node (contained in the RosterRefreshRequest) as the Channel ID, specifying High data priority, and including the RosterUpdateIndication PDU in the Data field. + +As mentioned above, the RosterUpdateIndication PDU issued back to the node that made the original RosterRefreshRequest will look different depending on the Node Category to which the originating node belongs. For instance, if a Conventional node initiated the request, the roster refresh will contain records for both Conventional and Counted nodes. Therefore, a Conventional Parent node must be reached before the request can be processed (because only Conventional nodes maintain a list of Counted nodes). If the requesting node is either Anonymous or Counted, the request can be handled by the first node that contains the Conventional node roster. It is the responsibility of the node processing the RosterRefreshRequest to separate out records that should not be received by certain Node Categories. + +The RosterRefreshRequest includes the following: a Node ID field which is filled in with the Node ID of the node initiating the request; a Node Category field which is filled in with Category of the node initiating the request; a Boolean value specifying that a Full Roster refresh should be delivered; a Boolean value specifying that the Conference Roster should be sent; a Session List that includes a list of specific session rosters being requested; and an Application List that specifies a list of Application Protocols that a node wants to obtain information on. If the Full Refresh Boolean is set to TRUE, then the sendConferenceRoster field, the sessionList field and the applicationList field are ignored. If the Full Refresh Boolean is set to FALSE, then these three fields define what information should be delivered to the node that initiated the request. Therefore, a RosterRefreshRequest can be issued that requests one or more specific Application Rosters, or for just the Conference Roster, as well as a Full Roster Refresh. The process of handling a partial request is identical to the process outlined above, except that only the requested information is returned. + +There are timing considerations that need to be addressed when a node attempts to join and synchronize its Conference Application Roster with other nodes in the conference. It is possible for a node to receive RosterUpdateIndications before it has received its initial Full Roster refresh from a Parent node. If these updates include a roster instance number that precedes the roster instance number associated with the Full Roster Refresh, the update can be thrown away. If these instance numbers are higher than the instance number associated with the Full Refresh, they need to be + +processed. Therefore, it is necessary for a joining node to buffer any incoming RosterUpdateIndications received from the Top GCC Provider prior to receiving the response to its initial RosterRefreshRequest. All RosterUpdateIndications include an instance number that is sequentially incremented every time the Top Provider detects that a roster changed. This roster instance number is used to determine the order that a RosterUpdateIndication should be processed at a joining node. As discussed above, this can be especially complicated for Conventional nodes that are participating in a conference that can include both Conventional and Counted nodes. This is because RosterUpdateIndications will be received on both the GCC-Conventional-Broadcast-Channel and the GCC-Counted-Broadcast-Channel. It is the responsibility of the Conventional node to process the RosterUpdateIndications in the correct order based on prior knowledge that the roster instance numbers are incremented sequentially. + +#### **8.3.3.9 An example of a roster update** + +Figure 8-6 shows the roster-related protocol that occurs when a new Conventional Node joins a conference. A single enrolling Client Application is shown running on the joining node. After the GCC Provider receives a GCC-Announce-Presence-Request and a GCC-Application-Enroll request, an update of the Conference Application Roster is issued to the Next Higher Node. In this example, the joining node is in the third layer of the connection hierarchy. It issues the update indication to the next higher node which then formats and sends an update indication to the next higher node, which, in this example, is the top node in the hierarchy. The top node assembles the full Application Roster and broadcasts the portions associated with the update to all nodes in the conference. This results in a GCC-Conference-Report and a GCC-Application-Report primitive being issued at all nodes in the conference, except the joining Conventional node. Instead, the joining node must acquire the full roster from its Parent node by issuing a RosterRefreshRequest. After the response to this request is received, a GCC-Conference-Report and a GCC-Application-Report primitive can be issued at the joining node. + +![Sequence diagram showing the process of updating the Application Roster across three nodes: Joining Node, Next Higher Node, and Top Node. The diagram illustrates the flow of messages between various providers and controllers within these nodes, including requests for data, roster updates, and confirmations.](3eb2af31c2e61e2595c8440d726f5d4e_img.jpg) + +``` + +sequenceDiagram + participant JN_NC as Joining Node: Node Controller and Client App. + participant JN_GCC as Joining Node: GCC Provider + participant JN_MCS as Joining Node: MCS Provider + participant NH_MCS_P as Next Higher Node: MCS Provider + participant NH_GCC as Next Higher Node: GCC Provider + participant NH_MCS_S as Next Higher Node: MCS Provider + participant T_MCS as Top Node: MCS Provider + participant T_GCC as Top Node: Top GCC Provider + participant T_NC as Top Node: Node Controller + + JN_NC->>JN_GCC: GCC-Announce-Presence.request + JN_NC->>JN_GCC: GCC-Application-Enroll.request + JN_GCC->>JN_MCS: MCS-Send-Data.request + JN_MCS-->>NH_MCS_P: RosterUpdateIndication + NH_MCS_P->>NH_GCC: MCS-Send-Data.indication + NH_GCC->>NH_MCS_S: MCS-Send-Data.request + NH_MCS_S-->>T_MCS: RosterUpdateIndication + T_MCS->>T_GCC: MCS-Send-Data.indication + T_GCC->>T_NC: GCC-Conference-Roster-Report.indication + T_NC->>T_GCC: GCC-Application-Roster-Report.indication + T_GCC->>T_MCS: MCS-Send-Data.request + T_MCS-->>NH_MCS_S: RosterUpdateIndication + NH_MCS_S->>NH_GCC: MCS-Send-Data.indication + NH_GCC->>NH_MCS_P: MCS-Send-Data.request + NH_MCS_P-->>JN_MCS: RosterRefreshRequest + JN_MCS->>JN_GCC: MCS-Send-Data.indication + JN_GCC->>JN_MCS: MCS-Send-Data.request + JN_MCS-->>NH_MCS_P: RosterUpdateIndication + NH_MCS_P->>NH_GCC: MCS-Send-Data.indication + NH_GCC->>NH_MCS_P: MCS-Send-Data.request + NH_MCS_P-->>JN_MCS: RosterUpdateIndication + JN_MCS->>JN_GCC: MCS-Send-Data.indication + JN_GCC->>JN_NC: GCC-Conference-Roster-Report.indication + JN_NC->>JN_GCC: GCC-Application-Roster-Report.indication + JN_GCC->>JN_NC: GCC-Application-Enroll.confirm + + Note over NH_MCS_P, NH_MCS_S: All Nodes + T_GCC->>T_MCS: MCS-Send-Data.request + T_MCS-->>NH_MCS_S: RosterUpdateIndication + NH_MCS_S->>NH_GCC: MCS-Send-Data.indication + NH_GCC->>NH_NC: GCC-Conference-Roster-Report.indication + NH_NC->>NH_GCC: GCC-Application-Roster-Report.indication + +``` + +T.124(01-07)\_F8-06 + +Sequence diagram showing the process of updating the Application Roster across three nodes: Joining Node, Next Higher Node, and Top Node. The diagram illustrates the flow of messages between various providers and controllers within these nodes, including requests for data, roster updates, and confirmations. + +**Figure 8-6 – Another example of updating the Application Roster** + +### 8.3.4 Collapsing Application Capabilities Lists + +Each GCC Provider is responsible for forming, for each Application Protocol Session, the collapsed Application Capability List corresponding to the Conventional nodes below it in the connection hierarchy, as well as any Peer Application Protocol Entities enrolled at the local node (if it is Conventional). Since the nodes directly below in the connection hierarchy take care of collapsing their own capabilities, the local GCC Provider need only be aware of the collapsed Application Capability Lists from those nodes, rather than the Application Capability Lists from all lower nodes. Given as input, these collapsed Application Capabilities Lists as well as the Application Capabilities Lists from Peer Application Protocol Entities at the local node from the Local Application Roster, the GCC Provider shall produce a collapsed Application Capabilities List by the following procedure: + +- For each capability item in each list, determine the class of the capability. + +- For any class, the value of the count parameter for the entry in the collapsed Application Capabilities List shall be set to the sum of the counts indicated in the corresponding entry of each of the Application Capabilities Lists in the input set. +- For the Unsigned-minimum and Unsigned-maximum classes, the new entry should also include the minimum or maximum value, respectively, of the values given for the corresponding entry of each of the Application Capabilities Lists in the input set. + +### 8.3.5 Application and conference roster inquiry + +On receipt of a GCC-Application-Roster-Inquire request primitive, a GCC Provider which supports this primitive may respond by generating a GCC-Application-Roster-Inquire confirm primitive and issuing it to the GCCSAP of the requester. The content of the confirm primitive is generated from the locally-maintained Conference Application Roster database and shall include only those entries in the roster for which the Session Key specified in the request exactly matches the Session Key of the entry over the length of the key given in the request. + +On receipt of a GCC-Conference-Roster-Inquire request primitive, a GCC Provider which supports this primitive shall respond by generating a GCC-Conference-Roster-Inquire confirm primitive and issuing it to the GCCSAP of the requester. The content of the confirm primitive is generated from the local Conference Roster database accounting for all nodes known to be in the conference. + +A GCC Provider at an Anonymous node that receives a roster inquiry may not be maintaining a local Conference Application Roster database since this is not an Anonymous node requirement. These type of nodes can respond to the roster inquiry either by sending back a failed confirm to the requesting GCCSAP or by sending a RosterRefreshRequest up to its Parent node to get the requested roster information. The RosterRefreshRequest will eventually result in a RosterReportIndication that includes the requested information. At this point, the GCC Provider responds by generating a GCC-Application-Roster-Inquire confirm primitive and issues it to the GCCSAP of the requester. Note that Conventional and Counted nodes are required to maintain a local Conference Application Roster database, so roster inquiries at these nodes can be processed immediately. + +### 8.3.6 Remotely invoking an Application Protocol Entity + +On receipt of a GCC-Application-Invoke request primitive via either the Control GCCSAP or an ordinary GCCSAP, a GCC Provider which supports this primitive shall broadcast an ApplicationInvokeIndication PDU to all nodes in the specified conference. This is done by issuing an MCS-Send-Data request or MCS-Uniform-Send-Data request specifying both the GCC-Broadcast-Channel (to support older protocol nodes) and the GCC-Conventional-Broadcast Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. Alternatively, the GCC Provider may issue one or more MCS-Send-Data request specifying the Node ID of one of the listed destination nodes as the Channel ID, also specifying High data priority, and including the PDU in the Data field. In this case, it may leave the Destination Node List parameter in the PDU empty. The content of the ApplicationInvokeIndication PDU is shown in Table 8-36. The GCC Provider shall then generate a GCC-Application-Invoke confirm primitive indicating if the requested operation was successful and issue it to the GCCSAP of the requester. + +**Table 8-36 – ApplicationInvokeIndication GCCPDU** + +| Content | Source | Sink | +|----------------------------------|---------|---------------------------| +| Application Protocol Entity List | Request | Indication | +| Destination Node List or NULL | Request | Destination GCC Providers | + +On receipt of an ApplicationInvokeIndication PDU, a GCC Provider which supports the GCC-Application-Invoke primitive shall first determine if local node is on the list of destination nodes. If the list is either NULL, or if the local Node ID is present in the list, the GCC Provider may generate a GCC-Application-Invoke indication primitive and issue it to the Control GCCSAP. The Invoking Node parameter is filled in from the Sender User ID field in the received MCS-Send-Data indication or MCS-Uniform-Send-Data indication. If the local node is not on the list of destination nodes (if listed explicitly), no further action is taken. + +## **8.4 The Application Registry** + +The Application Registry is an active database which resides at the Top GCC Provider for a conference. Any MCU node shall support the full set of registry services which operate on this database, while a terminal node may choose to support only those registry services required by Application Protocols to be supported within that terminal. + +When a conference is created, the registry database, located at the Top GCC Provider, shall be initialized to a state in which all registry entries are empty and no registry entries are designated to be monitored. This shall be done prior to the time that the Top GCC Provider joins its Node ID Channel. + +During operation of the registry within a conference, each non-empty registry entry contains the following information: + +- The Registry Key which identifies the entry. +- The type of information contained – either a Channel ID, a Token ID, or a Parameter. +- The monitoring state – either monitoring enabled, or monitoring disabled. +- The value of the entry – the actual Channel ID, Token ID, or Parameter. +- The owner of the entry – either none, or the Node ID and Entity ID corresponding to the owning Application Protocol Entity. +- For Parameter type entries only, the modification rights of the entry – either Owner, Session, or Public. + +Processing by the Top GCC Provider of multiple registry requests from a single node shall be performed strictly in the order that the requests were received. The sequence of response PDUs to a requesting node shall preserve the order of the received requests from that node. + +At the requesting node, order shall also be preserved between the request primitives and the corresponding transmitted PDUs as well as between the received PDUs and the corresponding confirm primitives. + +Only Conventional nodes are allowed to add, delete, or change an entry in the Registry database. The Registry is read-only for all other Node Categories. Therefore, Anonymous and Counted nodes that do not appear to be enrolled in the conference may still access the Registry database. + +### 8.4.1 Registering a channel + +On receipt of a GCC-Registry-Register-Channel request primitive, a GCC Provider at a Conventional node shall send a RegistryRegisterChannelRequest PDU to the Top GCC Provider by issuing an MCS-Send-Data request specifying the Node ID Channel of the Top GCC Provider as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryRegisterChannelRequest PDU is shown in Table 8-37. A GCC-Registry-Register-Channel request made by either a Counted or Anonymous node will be ignored by the GCC Provider. + +**Table 8-37 – RegistryRegisterChannelRequest GCCPDU** + +| Content | Source | Sink | +|------------|---------------------|------------------| +| Entity ID | Source GCC Provider | Top GCC Provider | +| Key | Request | Top GCC Provider | +| Channel ID | Request | Top GCC Provider | + +On receipt of the RegistryRegisterChannelRequest PDU, the Top GCC Provider shall first verify that the Sender User ID in the received MCS-Send-Data indication and the Entity ID included in the PDU correspond exactly to the Node ID and Entity ID of an Application Protocol Entity at a Conventional node currently in the Application Roster. If so, it shall attempt to register the channel by creating an appropriate registry entry. First, it checks whether the registry entry corresponding to the specified Key already exists in the registry database. If the registry entry does not exist, the Top GCC Provider creates an entry for this Key and includes in the database for this entry the Node ID as indicated by the Sender User ID in the received MCS-Send-Data indication along with the Entity ID included in the PDU as the entry owner, the entry type being a Channel ID, and the value being the Channel ID specified in the PDU. + +The Top GCC Provider then indicates that the channel has been properly registered by sending a RegistryResponse PDU to the requesting node by issuing an MCS-Send-Data request specifying the Node ID of the requester as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryResponse PDU is shown in Table 8-38. In the case of a successful action, the Result parameter is specified as successful. The Modification Rights field is not filled in (this field is for Parameter type entries only). + +If the registry entry already existed, if the requester was invalid due to not appearing in the Application Roster, if the requesting node was not a Conventional node, or if the registry entry could not be created due to a limitation in the available resources, the registry is not modified and a RegistryResponse PDU is returned as above, but with a negative Result indicating the reason for the failure. In this case, the value of the entry prior to attempting to modify it is returned as the Registry Item in the RegistryResponse PDU. + +**Table 8-38 – RegistryResponse GCCPDU** + +| Content | Source | Sink | +|-------------------------------------------------------------------------------------------------------------|------------------|--------------------------| +| Entity ID | Top GCC Provider | Destination GCC Provider | +| Primitive type (register-channel, assign-token, set-parameter, retrieve-entry, delete-entry, monitor-entry) | Top GCC Provider | Destination GCC Provider | +| Key | Top GCC Provider | Confirm | +| Registry Item | Top GCC Provider | Confirm | +| Owner | Top GCC Provider | Confirm | +| Modification Rights (optional) | Top GCC Provider | Confirm | +| Result | Top GCC Provider | Confirm | + +In the case of a successful modification of an existing registry entry, the Top GCC Provider checks to determine if the registry entry had been set to be monitored. If not, no further action is taken by the Top GCC Provider. If the entry had been set to be monitored, the Top GCC Provider sends a RegistryMonitorEntryIndication PDU to all nodes in the conference by issuing an MCS-Uniform-Send-Data request specifying the GCC-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryMonitorEntryIndication PDU is shown in Table 8-44. + +On receipt of a RegistryResponse PDU of this type, a GCC Provider shall generate a GCC-Registry-Register-Channel confirm primitive indicating whether or not the request was successful as indicated in the Result parameter of the RegistryResponse PDU and issue it on the GCCSAP of the Application Protocol Entity indicated by the Entity ID. If the GCC Provider knows of no currently enrolled Application Protocol Entity with the corresponding Entity ID, the indication is ignored and no further action is taken. + +### 8.4.2 Assigning a Token + +On receipt of a GCC-Registry-Assign-Token request primitive, a GCC Provider at a Conventional node shall send a RegistryAssignTokenRequest PDU to the Top GCC Provider by issuing an MCS-Send-Data request specifying the Node ID Channel of the Top GCC Provider as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryAssignTokenRequest PDU is shown in Table 8-39. A GCC-Registry-Assign-Token request made by either a Counted or Anonymous node will be ignored by the GCC Provider. + +**Table 8-39 – RegistryAssignTokenRequest GCCPDU** + +| Content | Source | Sink | +|-----------|---------------------|------------------| +| Entity ID | Source GCC Provider | Top GCC Provider | +| Key | Request | Top GCC Provider | + +On receipt of the RegistryAssignTokenRequest PDU, the Top GCC Provider shall first verify that the Sender User ID in the received MCS-Send-Data indication and the Entity ID included in the PDU correspond exactly to the Node ID and Entity ID of an Application Protocol Entity at a Conventional node currently in the Application Roster. If so, it shall attempt to assign a token by allocating a Token ID and creating an appropriate registry entry. First, it checks whether the registry entry corresponding to the specified Key already exists in the registry database. If the registry entry does not exist, the Top GCC Provider first allocates a new Token ID from the space of dynamic Token IDs (16 384 through 65 535). The Top GCC Provider then creates an entry for this Key and includes in the database for this entry the Node ID as indicated by the Sender User ID in the + +received MCS-Send-Data indication along with the Entity ID included in the PDU as the entry owner, the entry type being a Token ID, and the value being the allocated Token ID. + +The Top GCC Provider then indicates that the token has been properly allocated, and returns the value of the Token ID to the requester, by sending a RegistryResponse PDU to the requesting node by issuing an MCS-Send-Data request specifying the Node ID of the requester as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryResponse PDU is shown in Table 8-38. In the case of a successful action, the Result parameter is specified as successful. The Modification Rights field is not filled in (this field is for Parameter type entries only). + +If the registry entry already existed, if the requester was invalid due to not appearing in the Application Roster, if the requesting node was not a Conventional node, if the registry entry could not be created due to a limitation in the available resources, or if there are no more available dynamic Token IDs, the registry is not modified and a RegistryResponse PDU is returned as above, but with a negative Result indicating the reason for the failure. In this case, the value of the entry prior to attempting to modify it is returned as the Registry Item in the RegistryResponse PDU. + +In the case of a successful modification of an existing registry entry, the Top GCC Provider checks to determine if the registry entry had been set to be monitored. If not, no further action is taken by the Top GCC Provider. If the entry had been set to be monitored, the Top GCC Provider sends a RegistryMonitorEntryIndication PDU to all nodes in the conference by issuing an MCS-Uniform-Send-Data request specifying the GCC-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryMonitorEntryIndication PDU is shown in Table 8-44. + +On receipt of a RegistryResponse PDU of this type, a GCC Provider shall generate a GCC-Registry-Assign-Token confirm primitive indicating whether or not the request was successful as indicated in the Result parameter of the RegistryResponse PDU, and if successful, the value of the allocated Token ID and issue it on the GCCSAP of the Application Protocol Entity indicated by the Entity ID. If the GCC Provider knows of no currently enrolled Application Protocol Entity with the corresponding Entity ID, the indication is ignored and no further action is taken. + +### 8.4.3 Setting a Parameter + +On receipt of a GCC-Registry-Set-Parameter request primitive, a GCC Provider at a Conventional node shall send a RegistrySetParameterRequest PDU to the Top GCC Provider by issuing an MCS-Send-Data request specifying the Node ID Channel of the Top GCC Provider as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistrySetParameterRequest PDU is shown in Table 8-40. A GCC-Registry-Set-Parameter request made by either a Counted or Anonymous node will be ignored by the GCC Provider. + +**Table 8-40 – RegistrySetParameterRequest GCCPDU** + +| Content | Source | Sink | +|--------------------------------|---------------------|------------------| +| Entity ID | Source GCC Provider | Top GCC Provider | +| Key | Request | Top GCC Provider | +| Parameter | Request | Top GCC Provider | +| Modification Rights (optional) | Request | Top GCC Provider | + +On receipt of the RegistrySetParameterRequest PDU, the Top GCC Provider shall first verify that the Sender User ID in the received MCS-Send-Data indication and the Entity ID included in the PDU correspond exactly to the Node ID and Entity ID of an Application Protocol Entity at a Conventional node currently in the Application Roster. If so, it shall attempt to set a parameter in an + +existing registry entry or create a new entry with the specified parameter. First, it checks whether the registry entry corresponding to the specified Key already exists in the registry database, and if so, determines the type of the entry, the owner, and the current modification rights. If the registry entry does not exist, the Top GCC Provider then creates an entry for this Key and includes in the database for this entry the Node ID as indicated by the Sender User ID in the received MCS-Send-Data indication along with the Entity ID included in the PDU as the entry owner, the entry type being a Parameter, and the value being the Parameter value specified in the PDU. If the registry entry already existed, and if the entry was of the Parameter type, the GCC Provider shall first check if the requester has the right to modify this entry. If the owner has modification rights, the value of the registry entry is modified to reflect the type as a Parameter and the value as the Parameter value specified in the PDU. If the entry was not owned prior to being set, the entry is modified to indicate the new owner. + +The determination of whether the owner has modification rights is by the following rules. If the current Modification Rights attribute of the entry is set to Owner, the requester, as indicated by the Entity ID and the Node ID from the Sender User ID field of the received MCS-Send-Data indication, must be the owner or the entry must currently be un-owned for the request to succeed. If the current Modification Rights attribute of the entry is set to Session, the requester must be part of the same Application Protocol Session for this request to succeed. This is determined by finding the entry in the current Application Roster for the requester and examining the Session Key. The Session Key must be identical to that of the owner. Again, if the entry is not owned, this restriction does not apply. If the current Modification Rights attribute of the entry is set to Public, there are no restrictions on the requester for the request to succeed other than the node being a Conventional node. + +When a Parameter entry is first created, the state of Modification Rights for the entry is determined. If the Modification Rights parameter was included in the request PDU which resulted in the creation of the entry, the Modification Type is set to the indicated value. If not, the value Public is assumed for Modification Rights. On requests to set the parameter, if the Modification Rights entry is not present, the Modification Rights state is not changed. If it is present, the GCC Provider shall change the Modification Rights state to the state indicated in the PDU only if the requester is the current owner of the entry, or if the entry is currently un-owned. Otherwise, the Modification Rights state is not changed. In the latter case, the set-parameter operation shall still proceed as normal, and the result shall not be effected. + +In either of the above cases, the Top GCC Provider then indicates that the parameter has been properly set by sending a RegistryResponse PDU to the requesting node by issuing an MCS-Send-Data request specifying the Node ID of the requester as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryResponse PDU is shown in Table 8-38. In the case of a successful action, the Result parameter is specified as successful. The Modification Rights parameter shall be included in the response PDU. + +If the registry entry could not be created due to a limitation in the available resources, if the requesting node was not a Conventional node, if the entry already existed but the requester did not have modification rights, if the requester was invalid due to not appearing in the Application Roster, or if the entry was of the Parameter type, the registry is not modified and a RegistryResponse PDU is returned as above, but with a negative Result indicating the reason for the failure. In this case, the value of the entry prior to attempting to modify it is returned as the Registry Item in the RegistryResponse PDU. In the case of insufficient modification rights, the result parameter shall be: belongs to other. + +In the case of a successful modification of an existing registry entry, the Top GCC Provider checks to determine if the registry entry had been set to be monitored. If not, no further action is taken by the Top GCC Provider. If the entry had been set to be monitored, the Top GCC Provider sends a RegistryMonitorEntryIndication PDU to all nodes in the conference by issuing an MCS-Uniform- + +Send-Data request specifying the GCC-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryMonitorEntryIndication PDU is shown in Table 8-44. + +On receipt of a RegistryResponse PDU of this type, a GCC Provider shall generate a GCC-Registry-Set-Parameter confirm primitive indicating whether or not the request was successful as indicated in the Result parameter of the RegistryResponse PDU and issue it on the GCCSAP of the Application Protocol Entity indicated by the Entity ID. If the GCC Provider knows of no currently enrolled Application Protocol Entity with the corresponding Entity ID, the indication is ignored and no further action is taken. + +### 8.4.4 Retrieving an Entry + +On receipt of a GCC-Registry-Retrieve-Entry request primitive, a GCC Provider shall send a RegistryRetrieveEntryRequest PDU to the Top GCC Provider by issuing an MCS-Send-Data request specifying the Node ID Channel of the Top GCC Provider as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryRetrieveEntryRequest PDU is shown in Table 8-41. A RegistryRetrieveEntryRequest can be issued by any node regardless of Node Category. + +**Table 8-41 – RegistryRetrieveEntryRequest GCCPDU** + +| Content | Source | Sink | +|-----------|---------------------|------------------| +| Entity ID | Source GCC Provider | Top GCC Provider | +| Key | Request | Top GCC Provider | + +On receipt of the RegistryRetrieveEntryRequest PDU, the Top GCC Provider shall examine the contents of the registry entry specified by the Key. The registry entry may be in one of four possible states: empty, containing a Channel ID, a Token ID, or a Parameter. For any of these cases, the Top GCC Provider returns the state of the entry to the requester by sending a RegistryResponse PDU to the requesting node by issuing an MCS-Send-Data request specifying the Node ID of the requester as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryResponse PDU is shown in Table 8-38. The Registry Item parameter contains the state of the entry, and in the case of a non-empty state, the value that the entry currently contains. The Result parameter is specified as successful if the entry is non-empty, and entry-not-found if the entry is empty. If the entry is indicated to be of the Parameter type, the Modification Rights parameter shall be included in the response PDU. + +On receipt of a RegistryResponse PDU of this type, a GCC Provider shall generate a GCC-Registry-Retrieve-Entry confirm primitive indicating the registry item included in the response PDU and issue it on the GCCSAP of the Application Protocol Entity indicated by the Entity ID. If the GCC Provider knows of no currently enrolled Application Protocol Entity with the corresponding Entity ID, the indication is ignored and no further action is taken. + +### 8.4.5 Deleting an Entry + +On receipt of a GCC-Registry-Delete-Entry request primitive, a GCC Provider at a Conventional node shall send a RegistryDeleteEntryRequest PDU to the Top GCC Provider by issuing an MCS-Send-Data request specifying the Node ID Channel of the Top GCC Provider as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryDeleteEntryRequest PDU is shown in Table 8-42. A GCC-Registry-Delete-Entry request made by either a Counted or Anonymous node will be ignored by the GCC Provider. + +**Table 8-42 – RegistryDeleteEntryRequest GCCPDU** + +| Content | Source | Sink | +|-----------|---------------------|------------------| +| Entity ID | Source GCC Provider | Top GCC Provider | +| Key | Request | Top GCC Provider | + +On receipt of the RegistryDeleteEntryRequest PDU, the Top GCC Provider shall attempt to delete the designated registry entry. First, it checks whether the registry entry corresponding to the specified Key exists in the registry database, and if so, determines the owner. If the registry entry exists and is owned by the requester (both the Node ID and Entity ID of the owner and those of the requester are identical) or if the entry is not currently owned and the requesting node is a Conventional node, the Top GCC Provider deletes the contents of the entry setting the state to empty and not monitored. + +If the registry entry is successfully deleted, or if the entry already did not exist, the Top GCC Provider then indicates that the entry has been properly deleted by sending a RegistryResponse PDU to the requesting node by issuing an MCS-Send-Data request specifying the Node ID of the requester as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryResponse PDU is shown in Table 8-38. In the case of a successful action, the Result parameter is specified as successful, and the registry item is specified to be empty. + +If the registry entry already existed but was owned by another node, or if the requesting node is not a Conventional node, the registry is not modified and a RegistryResponse PDU is returned as above, but with a negative Result indicating the reason for the failure. In this case, the registry item is set to the value of the entry prior to the deletion attempt. + +In the case of a successful deletion of an existing registry entry, the Top GCC Provider checks to determine if the registry entry had been set to be monitored (prior to deletion). If not, no further action is taken by the Top GCC Provider. If the entry had been set to be monitored, the Top GCC Provider sends a RegistryMonitorEntryIndication PDU to all nodes in the conference by issuing an MCS-Uniform-Send-Data request specifying the GCC-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryMonitorEntryIndication PDU is shown in Table 8-44. + +In the case of a successful deletion of a Token type registry entry, the Top GCC Provider may de-allocate the corresponding token. That is, the Top GCC Provider may later re-use the Token ID which had been included in the deleted entry in response to a RegistryAssignTokenRequest. + +On receipt of a RegistryResponse PDU of this type, a GCC Provider shall generate a GCC-Registry-Delete-Entry confirm primitive indicating whether or not the request was successful as indicated in the Result parameter of the RegistryResponse PDU and issue it on the GCCSAP of the Application Protocol Entity indicated by the Entity ID. If the GCC Provider knows of no currently enrolled Application Protocol Entity with the corresponding Entity ID, the indication is ignored and no further action is taken. + +### **8.4.6 Monitoring an Entry** + +On receipt of a GCC-Registry-Monitor request primitive with the Enable/Disable flag set to Enable, a GCC Provider at a Conventional node shall send a RegistryMonitorEntryRequest PDU to the Top GCC Provider by issuing an MCS-Send-Data request specifying the Node ID Channel of the Top GCC Provider as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryMonitorEntryRequest PDU is shown in Table 8-43. A local record that the requesting Application Protocol Entity had enabled monitoring this entry is made by the GCC Provider to determine whether to generate GCC-Registry-Monitor indications on later receipt + +of RegistryMonitorEntryIndication PDU corresponding to this entry. A GCC-Registry-Monitor request made by either a Counted or Anonymous node will be ignored by the GCC Provider. + +On receipt of a GCC-Registry-Monitor request primitive with the Enable/Disable flag set to Disable, a local record that the requesting Application Protocol Entity had disabled monitoring this entry is made by the GCC Provider to determine whether to generate GCC-Registry-Monitor indications on later receipt of RegistryMonitorEntryIndication PDU corresponding to this entry. + +**Table 8-43 – RegistryMonitorEntryRequest GCCPDU** + +| Content | Source | Sink | +|-----------|---------------------|------------------| +| Entity ID | Source GCC Provider | Top GCC Provider | +| Key | Request | Top GCC Provider | + +On receipt of the RegistryMonitorEntryRequest PDU, the Top GCC Provider shall attempt to change the monitoring state of the registry entry if the requesting node is a Conventional node. First, it checks whether the registry entry corresponding to the specified Key already exists in the registry database. If the registry entry exists, the monitoring state for the specified entry is set to enabled. + +NOTE 1 – Once monitoring is enabled, monitor indications will continue to be broadcast whenever changes are made to the entry for the duration of the conference, or until the entry is deleted. + +Once the appropriate action has been taken, the Top GCC Provider sends a RegistryResponse PDU to the requesting node by issuing an MCS-Send-Data request specifying the Node ID of the requester as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryResponse PDU is shown in Table 8-38. In the case of a successful action, the Result parameter is specified as successful. If the requested entry did not exist, the Result parameter is specified as entry-not-found. If the entry is indicated to be of the Parameter type, the Modification Rights parameter shall be included in the response PDU. + +If the registry entry did not exist, the registry is not modified and a RegistryResponse PDU is returned as above, but with a negative Result indicating the reason for the failure. + +On receipt of a RegistryResponse PDU of this type, a GCC Provider shall generate a GCC-Registry-Monitor confirm primitive indicating whether or not the request was successful as indicated in the Result parameter of the RegistryResponse PDU and issue it on the GCCSAP of the Application Protocol Entity indicated by the Entity ID. If the GCC Provider knows of no currently enrolled Application Protocol Entity with the corresponding Entity ID, the indication is ignored and no further action is taken. + +While any registry entry is set to be monitored, any change in the content of the registry entry, including setting a parameter, deletion of the entry, change in ownership, or change in the Modification Rights state, cause the Top GCC Provider to send a RegistryMonitorEntryIndication PDU to all nodes in the conference by issuing an MCS-Uniform-Send-Data request specifying both the GCC-Broadcast-Channel (to support older protocol nodes) and the GCC-Conventional-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryMonitorEntryIndication PDU is shown in Table 8-44. + +**Table 8-44 – RegistryMonitorEntryIndication GCCPDU** + +| Content | Source | Sink | +|--------------------------------|------------------|------------| +| Key | Top GCC Provider | Indication | +| Registry Item | Top GCC Provider | Indication | +| Owner | Top GCC Provider | Confirm | +| Modification Rights (optional) | Top GCC Provider | Confirm | + +On receipt of a RegistryMonitorEntryIndication PDU, a GCC Provider for a node which supports the registry monitoring function shall generate a GCC-Registry-Monitor indication primitive and send this primitive to any GCCSAP which had previously issued a GCC-Registry-Monitor request specifying the same Key as is indicated in the indication PDU with the Enable/Disable flag set to Enable (without having more recently received one with this flag set to Disable). If there have not been any requesters for the particular Key at this node, the indication PDU is ignored by the GCC Provider. It is a function of each local GCC Provider to keep a local database of requesting GCCSAPs which is updated whenever a GCC-Registry-Monitor request is received. + +NOTE 2 – As a local matter, a particular GCC Provider implementation may choose not to keep track of which Application Protocol Entities have enabled or disabled monitoring for each entry and instead issue GCC-Registry-Monitor indications to the GCCSAPs corresponding to all enrolled Application Protocol Entities when a RegistryMonitorEntryIndication PDU is received. + +### 8.4.7 Allocation of Unique Handles + +On receipt of a GCC-Registry-Allocate-Handle request primitive, a GCC Provider shall send a RegistryAllocateHandleRequest PDU to the Top GCC Provider by issuing an MCS-Send-Data request specifying the Node ID Channel of the Top GCC Provider as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryAllocateHandleRequest PDU is shown in Table 8-45. + +**Table 8-45 – RegistryAllocateHandleRequest GCCPDU** + +| Content | Source | Sink | +|-------------------|---------------------|------------------| +| Entity ID | Source GCC Provider | Top GCC Provider | +| Number of Handles | Request | Top GCC Provider | + +On receipt of the RegistryAllocateHandleRequest PDU, the Top GCC Provider shall generate a unique set of handles of the number requested. This shall be done by incrementing a 32-bit state variable after each allocation modulo $2^{32}$ , using the incremented value for allocation of the next requested handle. If the full set of possible handles has been allocated, the request is rejected indicating that no handles are available. If a sufficient number of handles are available, the handles are returned to the requester by specifying the first allocated handle along with the number of allocated handles. The Top GCC Provider returns the result by sending a RegistryAllocateHandleResponse PDU to the requester. This is done by issuing an MCS-Send-Data request specifying the Node ID of the requester as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the RegistryAllocateHandleResponse PDU is shown in Table 8-46. If the result was successful, the registry item parameter contains the list of handles. + +**Table 8-46 – RegistryAllocateHandleResponse GCCPDU** + +| Content | Source | Sink | +|-------------------|------------------|--------------------------| +| Entity ID | Top GCC Provider | Destination GCC Provider | +| Number of Handles | Top GCC Provider | Confirm | +| First Handle | Top GCC Provider | Confirm | +| Result | Top GCC Provider | Confirm | + +On receipt of a RegistryAllocateHandleResponse indication, a GCC Provider shall generate a GCC-Registry-Allocate-Handle confirm primitive and issue it to the GCCSAP of the Application Protocol Entity indicated by the Entity ID. If the GCC Provider knows of no currently enrolled Application Protocol Entity with the corresponding Entity ID, the indication is ignored and no further action is taken. + +### **8.4.8 Changes in ownership and Registry Clean-up** + +Whenever the Application Roster is updated, the Top GCC Provider shall determine if any Application Protocol Entities were removed from the roster. If so, it shall examine the entire registry database to determine if the disconnecting Application Protocol Entities were the owner of any registry entries. If so, these entries are modified to indicate that there is no current owner. + +If the result of a change in the Application Roster indicates that all Application Protocol Entities in a session have become un-enrolled, the Top GCC Provider shall examine all registry entries to determine if the Session Key portion of the Registry Key matches the Session Key of the former session. For entries that do correspond to the removed session, the Top GCC Provider shall delete the registry entry. If that registry entry corresponded to a Token type entry, the Top GCC Provider may de-allocate the Token to allow for its later reuse. + +## **8.5 Conference conductorship** + +Conference conductorship is controlled through the use of the Conference-Conductorship-Token. When this token is free the conference is in Non-Conducted Mode. When this token is grabbed the conference is in Conducted Mode, and the grabber of the token is the Conference Conductor. The token can only be grabbed by Conventional nodes. Anonymous and Counted nodes can never act as the conductor of a conference. + +Upon acquiring the Conference-Conductorship-Token, the Conference Conductor (unless it is the Top GCC Provider itself) shall demonstrate possession of the token to the Top GCC Provider by offering to give it away, invoking MCS-Token-Give request and specifying the Top GCC Provider as recipient. The Top GCC Provider shall respond negatively to the resulting MCS-Token-Give indication, leaving the token in possession of the Conference Conductor. If the token is offered again later by the current Conference Conductor, the Top GCC Provider shall interpret it as part of a GCC-Conductor-Give operation and need not refuse automatically. + +### **8.5.1 Grabbing conductorship** + +On receipt of a GCC-Conductor-Assign request primitive, a GCC Provider at a Conventional node shall first examine the Conference Profile to determine if the conference is conductible or not. If not, it shall generate a GCC-Conductor-Assign confirm primitive with an unsuccessful result indicating that the conference is non-conductible. If the conference is conductible, the GCC Provider shall then examine its local database to determine if it is currently the conference conductor. If so, it shall generate a GCC-Conductor-Assign confirm primitive with a successful result and issue it to the Control GCCSAP. If not, it shall attempt to grab the conductor token by issuing the MCS primitive MCS-Token-Grab request, specifying the Conference-Conductorship-Token as the token ID to be grabbed. A GCC-Conductor-Assign request made by either a Counted or Anonymous node will be ignored by the GCC Provider. + +On receipt of the MCS-Token-Grab confirm primitive, the GCC Provider shall examine the Result parameter. If the Result is successful, the GCC Provider shall then issue the MCS primitive MCS-Token-Give request, specifying the Conference-Conductorship-Token as the token ID to be offered and the Node ID of the Top GCC Provider as the User ID to receive the token. On receipt of the MCS-Token-Give confirm primitive, the GCC Provider shall examine the Result parameter. If the Result is unsuccessful, the GCC Provider shall locally generate the GCC-Conductor-Assign confirm primitive indicating a successful result and issue it to the Control GCCSAP. + +On receipt of an MCS-Token-Give indication specifying the Conference-Conductorship-Token as the token ID offered, from a donor User ID that the Top GCC Provider does not recognize as the current Conference Conductor, the Top GCC Provider shall update its records to recognize the donor as Conference Conductor. It shall also send a ConductorAssignIndication PDU to all nodes in the conference by issuing an MCS-Uniform-Send-Data request specifying the GCC-Broadcast-Channel as the Channel ID, specifying Top data priority, and including the PDU in the Data field. The content of the ConductorAssignIndication PDU is shown in Table 8-47. + +If the Result parameter of the MCS-Token-Grab confirm indicates an unsuccessful result or the Result parameter of the MCS-Token-Give confirm indicates a successful result, the GCC Provider shall generate a GCC-Conductor-Assign confirm primitive indicating a negative result which reflects the unsatisfactory result and issue it to the Control GCCSAP. + +**Table 8-47 – ConductorAssignIndication GCCPDU** + +| Content | Source | Sink | +|-----------------|------------------|--------------------------| +| Conducting Node | Top GCC Provider | Destination GCC Provider | + +### 8.5.2 Releasing conductorship + +On receipt of a GCC-Conductor-Release request primitive, a GCC Provider shall first examine its local database to determine if it is currently the conference conductor. If not, it shall generate a GCC-Conductor-Release confirm primitive indicating a negative result and issue it to the Control GCCSAP. If it is currently the conductor, it shall first send a ConductorReleaseIndication PDU to all nodes in the conference by issuing an MCS-Uniform-Send-Data request specifying both the GCC-Broadcast-Channel (to support older protocol nodes) and the GCC-Conventional-Broadcast-Channel as the Channel ID, specifying Top data priority, and including the PDU in the Data field. The content of the ConductorReleaseIndication PDU is shown in Table 8-48 (there are no parameters in this PDU). It shall then release the conductor token by issuing the MCS primitive MCS-Token-Release request, specifying the Conference-Conductorship-Token as the token ID to be released. + +On receipt of the MCS-Token-Release confirm primitive, the GCC Provider shall locally generate the GCC-Conductor-Release confirm primitive indicating a successful result and issue it to the Control GCCSAP. + +**Table 8-48 – ConductorReleaseIndication GCCPDU** + +| Content | Source | Sink | +|---------------------|--------|------| +| -- No parameters -- | | | + +### 8.5.3 Conductor Assignment and Release Indications + +A node which supports Application Protocols that are specified to behave differently in Conducted mode and Non-conducted mode shall respond to receipt of ConductorAssignIndication and ConductorReleaseIndication PDUs. A node which does not support such Application Protocols may choose to ignore these indications. + +On receipt of a ConductorAssignIndication PDU as part of an MCS-Uniform-Send-Data indication, a GCC Provider shall examine the Conference Profile to determine if the conference is conductible or not. If not, it shall ignore this PDU. If the conference is conductible, it may generate a GCC-Conductor-Assign indication primitive and issue it to the Control GCCSAP as well as the GCCSAP of all enrolled Application Protocol Entities. + +For Conventional nodes, the GCC Provider shall first determine if the Sender User ID field of the MCS-Uniform-Send-Data indication indicates that the ConductorAssignIndication PDU was transmitted by the Top GCC Provider. If not, the PDU shall be ignored, and no indication primitive shall be generated. If the PDU was transmitted by the Top GCC Provider, the Node ID parameter of the primitive is set to the value indicated by the Conducting Node parameter in the received PDU. For any node that supports conductorship primitives, the GCC Provider shall also store the fact that the conference is now in conducted mode, as well as the Node ID of the conductor, in its local database. + +For Counted and Anonymous nodes, a ConductorAssignIndication can be received from either the Parent node or the Top GCC Provider. If the PDU is received from a node other than one of these, it shall be ignored, and no indication of the primitive shall be generated. If the PDU was transmitted by either the Parent node or the Top GCC Provider, the Node ID parameter of the primitive is set to the value indicated by the Conducting Node parameter in the received PDU. A ConductorAssignIndication received from the Top GCC Provider always overrides one received from a Parent node. Therefore, once a ConductorAssignIndication is received from the Top GCC Provider, any ConductorAssignIndication received from a Parent node shall be ignored. For a node which supports conductorship primitives and receives a valid ConductorAssignIndication, the GCC Provider shall store in its local database the fact that the conference is now in conducted mode, as well as the Node ID of the conductor. + +On receipt of a ConductorReleaseIndication PDU as part of an MCS-Uniform-Send-Data indication, a GCC Provider may generate a GCC-Conductor-Release indication primitive and issue it to the Control GCCSAP as well as to the GCCSAP of all enrolled Application Protocol Entities. + +For Conventional nodes, the GCC Provider shall first determine if the Sender User ID field of the MCS-Uniform-Send-Data indication indicates that the ConductorReleaseIndication PDU was transmitted by the Top GCC Provider or by the node that it currently records as the conductor. If not, the PDU shall be ignored, and no indication primitive shall be generated. For a node that supports conductorship primitives, the GCC Provider shall also store in its local database the fact that the conference is no longer in conducted mode. The GCC Provider shall also set its locally-stored permission flag to indicate that no conducted-mode permissions have been granted. + +For Counted and Anonymous nodes, a ConductorReleaseIndication can be received from either the Parent node, the Top GCC Provider, or the current Conductor. If the PDU is received from a node other than one of these, it shall be ignored, and no indication of the primitive shall be generated. If a Counted or Anonymous node receives a ConductorReleaseIndication on the GCC-Conventional-Broadcast-Channel and has yet to determine the current state of Conductorship within the conference (because it has not received an indication from its Parent), the node must assume that the ConductorReleaseIndication came from a valid node and should store in its local database the fact that the conference is not in conducted mode. Any ConductorReleaseIndication received on the GCC-Conventional-Broadcast-Channel shall override any ConductorReleaseIndication received from the Parent node. For a node that supports conductorship primitives and receives a valid ConductorReleaseIndication, the GCC Provider shall store in its local database the fact that the conference is not in conducted mode. + +A GCC Provider shall preserve the order of received ConductorAssignIndication and ConductorReleaseIndication PDUs received on either the GCC-Broadcast-Channel or the GCC-Conventional-Broadcast-Channel in generation of the corresponding indication primitives. + +The GCC Provider in a node which supports the conductorship primitives shall issue a GCC-Conductor-Assign or GCC-Conductor-Release indication to the GCCSAP associated with an Application Protocol Entity which newly enrolls after a conference has already been established. The current conductorship state as known by the GCC Provider determines which of these two primitives to issue. + +### **8.5.4 Asking to be given conductorship** + +On receipt of a GCC-Conductor-Please request primitive, a GCC Provider at a Conventional node shall first examine its local database to determine if the conference is in conducted mode. If not, it shall generate a GCC-Conductor-Please confirm with a negative result indicating that the conference is not in conducted mode and issue it to the Control GCCSAP. If in conducted mode, the GCC Provider issues an MCS-Token-Please request specifying the Conference-Conductorship-Token as the token requested. It also shall generate a GCC-Conductor-Please confirm indicating a successful result and issue it to the Control GCCSAP. + +On receipt of an MCS-Token-Please indication specifying the Conference-Conductorship-Token as the Token ID, a GCC Provider shall generate a GCC-Conductor-Please indication primitive indicating the Node ID of the requesting node obtained from the User ID parameter received in the MCS-Token-Please indication and issue it to the Control GCCSAP. A GCC-Conductor-Please request made by either a Counted or Anonymous node will be ignored by the GCC Provider. + +### **8.5.5 Giving conductorship** + +On receipt of a GCC-Conductor-Give request primitive, a GCC Provider shall first examine its local database to determine if it is the current conference conductor. If not, it shall generate a GCC-Conductor-Give confirm with a negative result indicating that the node is not currently the conductor and issue it to the Control GCCSAP. Otherwise, the GCC Provider shall attempt to give conductorship to the specified node by issuing an MCS-Token-Give request specifying the Conference-Conductorship-Token as the token ID, and the recipient node as specified in the GCC-Conductor-Give request. The node that is being given Conductorship should always be a Conventional node. + +On receipt of the MCS-Token-Give confirm primitive, the GCC Provider shall examine the Result parameter. If the Result is successful, the GCC Provider shall locally generate the GCC-Conductor-Give confirm primitive indicating a successful result and issue it to the Control GCCSAP. If the Result parameter of the MCS-Token-Give confirm indicates an unsuccessful result, the GCC Provider shall generate a GCC-Conductor-Give confirm primitive indicating a negative result which reflects the result indicated by the MCS-Token-Grab confirm and issue it to the Control GCCSAP. + +On receipt of the MCS-Token-Give indication primitive specifying the Conference-Conductorship-Token, a GCC Provider other than the Top GCC Provider shall generate a GCC-Conductor-Give indication primitive and issue it to the Control GCCSAP. On receipt of the GCC-Conductor-Give response, the GCC Provider shall examine the result parameter. If the result is successful, the GCC Provider shall issue the MCS-Token-Give response indicating that the token was accepted. + +If the GCC-Conductor-Give response indicates that the token is not to be accepted, the GCC Provider shall issue the MCS-Token-Give response indicating that the token was user-rejected. + +If a node which does not support conductorship primitives receives an MCS-Token-Give indication, the GCC Provider shall respond with an MCS-Token-Give response indicating a result of user-rejected. This includes Anonymous and Counted nodes. + +On receipt of an MCS-Token-Give indication primitive specifying the Conference-Conductorship-Token from a donor User ID that the Top GCC Provider does not record as the current conductor, the Top GCC Provider shall respond as specified in 8.5.1, automatically rejecting the token. If it already recognizes the donor as conductor, however, the Top GCC Provider shall generate a GCC-Conductor-Give indication primitive as specified above, like any other GCC Provider. + +### 8.5.6 Getting conductorship status + +On receipt of a GCC-Conductor-Inquire request, a GCC Provider shall first examine its own local database to determine if the conference is currently in conducted mode. If not, the GCC Provider shall generate a GCC-Conductor-Inquire confirm which indicates that the conference is not in conducted mode and issue it to the Control GCCSAP. Otherwise, it shall generate a confirm indicating that the conference is in conducted mode, and shall specify the Node ID of the conducting node as stored in its local database as the current conductor. In this case, if a node has just entered a conference and has not yet received a ConductorAssignIndication PDU from the conductor (and does not yet have the conductor's Node ID in its local database), the GCC Provider shall wait until this PDU is received before generating the GCC-Conductor-Inquire confirm. + +If the conference is in conducted mode, the GCC Provider shall determine the setting of the Permission Flag to be included in the GCC-Conductor-Inquire confirm by determining whether the local node is the current conductor (in which case permission is assumed to be granted), or, if not, whether the Node ID of the local node had been listed in the Permission List of most recent ConductorPermissionGrantIndication PDU which had been received since the last transition from non-conducted to conducted mode. If the local node does appear in this list, this flag is set to TRUE. If not, or if there had not been a ConductorPermissionGrantIndication PDU received since the most recent transition from non-conducted to conducted mode, then this flag is set to FALSE. + +### 8.5.7 Conductorship announcement when new nodes enter a conference + +If the Top GCC Provider receives an update to the Conference Roster with the flag set indicating that new Conventional nodes are present in the conference and the conference is currently in conducted mode, the Top GCC Provider shall send a ConductorAssignIndication PDU to all nodes in the conference by issuing an MCS-Uniform-Send-Data request specifying both the GCC-Broadcast-Channel (to support older protocol nodes) and the GCC-Conventional-Broadcast-Channel as the Channel ID, specifying Top data priority, and including the PDU in the Data field. The content of the ConductorAssignIndication PDU is shown in Table 8-47. The Conducting Node parameter indicates the Node ID of the current conductor. + +If the Top GCC Provider receives an update to the Conference Roster with the flag set indicating that new Conventional nodes are present in the conference and the conference is not currently in conducted mode, the Top GCC Provider shall send a ConductorReleaseIndication PDU to all nodes by issuing an MCS-Uniform-Send-Data request specifying both the GCC-Broadcast-Channel (to support older protocol nodes) and the GCC-Conventional-Broadcast-Channel as the Channel ID, specifying Top data priority, and including the PDU in the Data field. The content of the ConductorReleaseIndication PDU is shown in Table 8-48. + +If the Top GCC Provider receives a ConductorReleaseIndication from another node, which signals a change from the current conductorship state, prior to receiving its own transmitted ConductorAssignIndication, the Top GCC Provider shall re-issue a ConductorReleaseIndication to reflect the new state. + +If the Top GCC Provider receives a RosterUpdateIndication PDU indicating that new Counted or Anonymous nodes are present in the conference, the Top GCC Provider does not broadcast an initial conductorship announcement by sending either a ConductorAssignIndication or a ConductorReleaseIndication. Instead, the initial conductorship announcement is left up to the joining node's Parent node. This initial announcement is generated as follows: when a Parent node receives the Node ID of a newly joining Anonymous or Counted node, it must send the new node either a ConductorAssignIndication or a ConductorReleaseIndication to inform it of the current state of conductorship within the conference. If the conference is currently in conducted mode, the Parent node shall send a ConductorAssignIndication PDU directly to the new Counted or Anonymous node by issuing an MCS-Send-Data request specifying the Node ID of the new node as the Channel ID, specifying High data priority, and including the PDU in the Data field. If the + +conference is not currently in conducted mode, the Parent node shall send a ConductorReleaseIndication PDU directly to the new Counted or Anonymous node by issuing an MCS-Send-Data request specifying the Node ID of the new node as the Channel ID, specifying High data priority, and including the PDU in the Data field. + +A node which has just become joined to a conference shall delay processing of any of the conductor related request primitives until receiving either a ConductorAssignIndication or a ConductorReleaseIndication. This is because all conductor related request primitives require that the local node check its local database of conductorship status which is not in harmony with the actual status of the conference until one of these PDUs is received. + +### 8.5.8 Unexpected disconnection of the conductor + +If the conductor of a conference unexpectedly disconnects from a conference, it may not have an opportunity to send a ConductorReleaseIndication PDU to all nodes indicating that the conference is now in non-conducted mode. The GCC Provider at each node (if it supports the conductorship primitives) shall monitor received MCS-Detach-User indications and compare the User ID in the indication to the Node ID of the node that it currently believes to be the conductor. If they match, the GCC Provider shall store in its local database that the conference is no longer in conducted mode, and the GCC Provider shall generate a GCC-Conductor-Release indication and issue it to the Control GCCSAP as well as to the GCCSAP of all enrolled Application Protocol Entities. The GCC Provider shall also set its locally-stored permission flag to indicate that no conducted-mode permissions have been granted. + +### 8.5.9 Asking to be given conducted-mode permission + +On receipt of a GCC-Conductor-Permission-Ask request primitive via the Control GCCSAP, a GCC Provider which supports this primitive shall first determine if the specified conference is in conducted mode. If not, it shall generate a GCC-Conductor-Permission-Ask confirm primitive and issue it to the Control GCCSAP indicating not-in-conducted-mode as the result. If in conducted mode, it shall send a ConductorPermissionAskIndication PDU to the conductor of the specified conference by issuing an MCS-Uniform-Send-Data request specifying the GCC-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the data field. The content of the ConductorAskIndication PDU is shown in Table 8-49. When successfully completed, the GCC Provider shall generate a GCC-Conductor-Permission-Ask confirm primitive and issue it to the Control GCCSAP indicating success as the result. + +**Table 8-49 – ConductorPermissionAskIndication GCCPDU** + +| Content | Source | Sink | +|--------------------|---------|------------| +| Grant/Release Flag | Request | Indication | + +On receipt of a ConductorPermissionAskIndication PDU, a GCC Provider shall determine if it is currently the conference conductor. If not, it shall ignore the PDU and take no further action. If so, if the GCC Provider supports the corresponding primitive, it shall generate a GCC-Conductor-Permission-Ask indication primitive and issue it to the Control GCCSAP. The Node ID of the Requester parameter shall be filled in with the Sender User ID parameter from the received MCS-Uniform-Send-Data indication. A GCC Provider shall preserve the order of received ConductorPermissionAskIndication PDUs in generating the corresponding indication primitives. + +### 8.5.10 Granting conducted-mode permission + +On receipt of a GCC-Conductor-Permission-Grant request via the Control GCCSAP, a GCC Provider which supports this primitive shall first determine if it is currently the conductor of the specified conference. If not, it shall generate a GCC-Conductor-Permission-Grant confirm indicating not-conductor as the reason for rejection, and issue it to the Control GCCSAP. It shall + +then take no further action. If the node is the current conference conductor, the GCC Provider shall broadcast a ConductorPermissionGrantIndication PDU to all nodes in the conference. It shall do this by issuing an MCS-Uniform-Send-Data request specifying the GCC-Broadcast-Channel as the Channel ID, specifying Top data priority, and including the PDU in the data field. The content of the ConductorPermissionGrantIndication PDU is shown in Table 8-50. The permission and waiting list parameters are filled in with the list of Node IDs provided in the corresponding parameters of the request primitive. The order of both lists is preserved. When successfully completed, the GCC Provider shall generate a GCC-Conductor-Permission-Grant confirm primitive and issue it to the Control GCCSAP indicating success as the result. + +**Table 8-50 – ConductorPermissionGrantIndication GCCPDU** + +| Content | Source | Sink | +|-------------------------|---------|------------| +| Permission List | Request | Indication | +| Waiting List (optional) | Request | Indication | + +On receipt of a ConductorPermissionGrantIndication PDU, a GCC Provider which supports the corresponding primitive shall first determine if the conference is currently in conducted mode. If not, it shall ignore the received PDU and take no further action. If the conference is in conducted mode, it shall determine if this PDU was received from the node which is the current conference conductor. If not, it shall also ignore this PDU and take no further action. If the source is the current conductor, it shall generate a GCC-Conductor-Permission-Grant indication primitive and issue it to the Control GCCSAP as well as to the GCCSAPs of all enrolled Application Protocol Entities. The Permission and Waiting Lists in the indication primitive are filled in directly from the corresponding parameters of the PDU, preserving the order of these lists. The GCC Provider shall examine the Permission List parameter and determine if the local node is included in this list. If so, it shall set the Permission Flag parameter of the indication primitive to TRUE. Otherwise, it shall set this flag to FALSE. A GCC Provider shall preserve the order of received ConductorPermissionGrantIndication PDUs in generating the corresponding indication primitives. + +## **8.6 Miscellaneous functions** + +### **8.6.1 Timed conferences** + +On receipt of a GCC-Conference-Time-Remaining request primitive, a GCC Provider shall send a ConferenceTimeRemainingIndication PDU to all nodes in the specified conference by issuing an MCS-Uniform-Send-Data request specifying both the GCC-Broadcast-Channel (to support older protocol nodes) and the GCC-Conventional-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the ConferenceTimeRemainingIndication PDU is shown in Table 8-51. The value of the Time Remaining parameter is obtained from the contents of the request primitive. The GCC Provider shall also generate a GCC-Conference-Time-Remaining confirm primitive indicating a successful result, and issue it to the Control GCCSAP. + +**Table 8-51 – ConferenceTimeRemainingIndication GCCPDU** + +| Content | Source | Sink | +|----------------------------|---------|------------| +| Time Remaining | Request | Indication | +| Node Identifier (optional) | Request | Indication | + +On receipt of a ConferenceTimeRemainingIndication PDU, a GCC Provider may optionally generate a GCC-Conference-Time-Remaining indication primitive and issue it to the Control GCCSAP. The Time Remaining parameter is obtained from the contents of the PDU. The Source Node parameter is filled in from the Sender User ID in the received MCS-Uniform-Send-Data indication. + +On receipt of a GCC-Conference-Time-Inquire request primitive, a GCC Provider shall send a ConferenceTimeInquireIndication PDU to the Conference Convener by issuing an MCS-Send-Data request specifying the GCC-Convener-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the ConferenceTimeInquireIndication PDU is shown in Table 8-52. The GCC Provider shall then generate a GCC-Conference-Time-Inquire confirm primitive and issue it to the Control GCCSAP. + +**Table 8-52 – ConferenceTimeInquireIndication GCCPDU** + +| Content | Source | Sink | +|-------------------------|---------|------------| +| Node-Specific Time Flag | Request | Indication | + +On receipt of a ConferenceTimeInquireIndication PDU, the GCC Provider (of the Conference Convener) may optionally generate a GCC-Conference-Time-Inquire indication primitive and issue it to the Control GCCSAP. The Node ID of the requester, as indicated in the Source Node parameter of the MCS-Send-Data indication, is used as the Node ID of the Requesting Node parameter in the GCC-Conference-Time-Inquire indication primitive. + +On receipt of a GCC-Conference-Extend request primitive, a GCC Provider shall send a ConferenceTimeExtendIndication PDU to the Conference Convener by issuing an MCS-Send-Data request specifying the GCC-Convener-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the ConferenceTimeExtendIndication PDU is shown in Table 8-53. The GCC Provider shall then generate a GCC-Conference-Extend confirm primitive and issue it to the Control GCCSAP. + +**Table 8-53 – ConferenceTimeExtendIndication GCCPDU** + +| Content | Source | Sink | +|-------------------------|---------|------------| +| Time to Extend | Request | Indication | +| Node-Specific Time Flag | Request | Indication | + +On receipt of a ConferenceTimeExtendIndication PDU, the GCC Provider (of the Conference Convener) may optionally generate a GCC-Conference-Extend indication primitive and issue it to the Control GCCSAP. The Node ID of the requester, as indicated in the Source Node parameter of the MCS-Send-Data indication, is used as the Node ID of the Requesting Node parameter in the GCC-Conference-Extend indication primitive. + +### 8.6.2 Requesting conference assistance + +On receipt of a GCC-Conference-Assistance request primitive, a GCC Provider shall send a ConferenceAssistanceIndication PDU to all the nodes in the specified conference by issuing an MCS-Send-Data or MCS-Uniform-Send-Data request specifying both the GCC-Broadcast-Channel (to support older protocol nodes) and the GCC-Conventional-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the ConferenceAssistanceIndication PDU is shown in Table 8-54. The GCC Provider shall then generate a GCC-Conference-Assistance confirm primitive indicating whether the operation was successful. + +**Table 8-54 – ConferenceAssistanceIndication GCCPDU** + +| Content | Source | Sink | +|----------------------|---------|------------| +| User Data (optional) | Request | Indication | + +On receipt of the ConferenceAssistanceIndication PDU, a node which supports this function may generate a GCC-Conference-Assistance indication primitive and issue it to the Control GCCSAP. The Source Node parameter is obtained from the Sender User ID in the received MCS-Uniform-Send-Data indication. + +### 8.6.3 Broadcasting a text message + +On receipt of a GCC-Text-Message request primitive, if no Destination Node parameter was included in the request, a GCC Provider shall send a TextMessageIndication PDU to the all nodes in the specified conference by issuing either an MCS-Send-Data request or MCS-Uniform-Send-Data request specifying both the GCC-Broadcast-Channel (to support older protocol nodes) and the GCC-Conventional-Broadcast-Channel as the Channel ID, specifying High data priority, and including the PDU in the Data field. If a Destination Node was indicated, the GCC Provider shall send the same PDU to that node by issuing an MCU-Send-Data request specifying the Node ID of the requested node as the Channel ID, specifying High data priority, and including the PDU in the Data field. The content of the TextMessageIndication PDU is shown in Table 8-55. The GCC Provider shall then generate a GCC-Text-Message confirm primitive indicating whether the operation was successful. + +**Table 8-55 – TextMessageIndication GCCPDU** + +| Content | Source | Sink | +|---------|---------|------------| +| Message | Request | Indication | + +On receipt of the TextMessageIndication PDU, a node which supports this function may generate a GCC-Text-Message indication primitive and issue it to the Control GCCSAP. The Source Node parameter is obtained from the Sender User ID in the received MCS-Uniform-Send-Data indication. + +## 8.7 GCCPDU definitions + +The structure of GCCPDUs is specified as follows using the notation ASN.1 of [ITU-T X.680]. All GCCPDUs shall be encoded for transmission by applying the Packed Encoding Rules of [ITU-T X.691] using the Basic Aligned variant. + +NOTE – The use of Automatic Tags in the GCC protocol definition implies that the order of SEQUENCE and CHOICE structures contained within this definition effects to the actual encoded values. + +``` +GCC-PROTOCOL {itu-t(0) recommendation(0) t(20) t124(124) version(0) 2 +asn1Modules(2) gcc-protocol(1)} DEFINITIONS AUTOMATIC TAGS ::= +BEGIN +``` + +``` +-- Export all symbols +``` + +``` +-- ===== +-- Part 1: Elements of which messages are composed +-- ===== +``` + +``` +ChannelID ::= INTEGER (1..65535) +StaticChannelID ::= INTEGER (1..1000) + -- Those assigned by specifications +DynamicChannelID ::= INTEGER (1001..65535) + -- Those created and deleted by MCS +UserID ::= DynamicChannelID +``` + +``` + +TokenID ::= INTEGER (1..65535) +StaticTokenID ::= INTEGER (1..16383) +-- Those assigned by specifications +DynamicTokenID ::= INTEGER (16384..65535) +-- Those assigned by the registry +Time ::= INTEGER (-2147483648..2147483647) +-- Time in seconds +Handle ::= INTEGER (0..4294967295) +-- 32-bit value + +H221NonStandardIdentifier ::= OCTET STRING (SIZE (4..255)) +-- First four octets shall be country code and +-- Manufacturer code, assigned as specified in +-- Annex A/H.221 for NS-cap and NS-comm + +Key ::= CHOICE -- Identifier of a standard or non-standard object +{ + object OBJECT IDENTIFIER, + h221NonStandard H221NonStandardIdentifier +} + +NonStandardParameter ::= SEQUENCE +{ + key Key, + data OCTET STRING +} + +TextString ::= BMPString (SIZE (0..255)) +-- Basic Multilingual Plane of ISO/IEC 10646-1 (Unicode) + +simpleTextFirstCharacter UniversalString ::= {0, 0, 0, 0} + +simpleTextLastCharacter UniversalString ::= {0, 0, 0, 255} + +SimpleTextString ::= BMPString (SIZE (0..255)) (FROM +(simpleTextFirstCharacter..simpleTextLastCharacter)) + +SimpleNumericString ::= NumericString (SIZE (1..255)) (FROM ("0123456789")) + +DiallingString ::= NumericString (SIZE (1..16)) (FROM ("0123456789")) + +SubAddressString ::= NumericString (SIZE (1..40)) (FROM ("0123456789")) + +ExtraDiallingString ::= TextString (SIZE (1..255)) (FROM ("0123456789#*,")) + +UserData ::= SET OF SEQUENCE +{ + key Key, + value OCTET STRING OPTIONAL +} + +Password ::= SEQUENCE +{ + numeric SimpleNumericString, + text SimpleTextString OPTIONAL, + ..., + unicodeText TextString OPTIONAL +} + +PasswordSelector ::= CHOICE +{ + numeric SimpleNumericString, + text SimpleTextString, + ..., + +``` + +``` + + unicodeText TextString +} + +ChallengeResponseItem ::= CHOICE +{ + passwordString PasswordSelector, + responseData UserData, + ... +} + +ChallengeResponseAlgorithm ::= CHOICE +{ + passwordInTheClear NULL, + nonStandardAlgorithm NonStandardParameter, + ... +} + +ChallengeItem ::= SEQUENCE +{ + responseAlgorithm ChallengeResponseAlgorithm, + challengeData UserData, + ... +} + +ChallengeRequest ::= SEQUENCE +{ + challengeTag INTEGER, + challengeSet SET OF ChallengeItem, + -- Set of algorithms offered for response + ... +} + +ChallengeResponse ::= SEQUENCE +{ + challengeTag INTEGER, + responseAlgorithm ChallengeResponseAlgorithm, + -- Specific algorithm selected from the set of + -- items presented in the ChallengeRequest + responseItem ChallengeResponseItem, + ... +} + +PasswordChallengeRequestResponse ::= CHOICE +{ + passwordInTheClear PasswordSelector, + challengeRequestResponse SEQUENCE + { + challengeRequest ChallengeRequest OPTIONAL, + challengeResponse ChallengeResponse OPTIONAL, + ... + }, + ... +} + +ConferenceName ::= SEQUENCE +{ + numeric SimpleNumericString, + text SimpleTextString OPTIONAL, + ..., + unicodeText TextString OPTIONAL +} + +ConferenceNameSelector ::= CHOICE +{ + +``` + +``` + + numeric SimpleNumericString, + text SimpleTextString, + ..., + unicodeText TextString + } + +ConferenceNameModifier ::= SimpleNumericString + +Privilege ::= ENUMERATED +{ + terminate (0), + ejectUser (1), + add (2), + lockUnlock (3), + transfer (4), + ... +} + +TerminationMethod ::= ENUMERATED +{ + automatic (0), + manual (1), + ... +} + +ConferencePriorityScheme ::= CHOICE +{ + nonStandardScheme NonStandardParameter, + ... +} + +ConferencePriority ::= SEQUENCE +{ + priority INTEGER (0..65535), + scheme ConferencePriorityScheme, + ... +} + +NodeCategory ::= CHOICE +{ + conventional NULL, + counted NULL, + anonymous NULL, + nonStandardCategory NonStandardParameter, + ... +} + +ConferenceMode ::= CHOICE +{ + conventional-only NULL, + counted-only NULL, + anonymous-only NULL, + conventional-control NULL, + unrestricted-mode NULL, + non-standard-mode NonStandardParameter, + ... +} + +NetworkAddress ::= SEQUENCE (SIZE (1..64)) OF CHOICE -- Listed in order of use +{ + aggregatedChannel SEQUENCE + { + transferModes SEQUENCE -- One or more + { + +``` + +``` + + speech BOOLEAN, + voice-band BOOLEAN, + digital-56k BOOLEAN, + digital-64k BOOLEAN, + digital-128k BOOLEAN, + digital-192k BOOLEAN, + digital-256k BOOLEAN, + digital-320k BOOLEAN, + digital-384k BOOLEAN, + digital-512k BOOLEAN, + digital-768k BOOLEAN, + digital-1152k BOOLEAN, + digital-1472k BOOLEAN, + digital-1536k BOOLEAN, + digital-1920k BOOLEAN, + packet-mode BOOLEAN, + frame-mode BOOLEAN, + atm BOOLEAN, + ... + }, + internationalNumber DiallingString, + subAddress SubAddressString OPTIONAL, + extraDialling ExtraDiallingString OPTIONAL, + highLayerCompatibility SEQUENCE + { + telephony3kHz BOOLEAN, + telephony7kHz BOOLEAN, + videotelephony BOOLEAN, + videoconference BOOLEAN, + audiographic BOOLEAN, + audiovisual BOOLEAN, + multimedia BOOLEAN, + ... + } OPTIONAL, + ... +}, +transportConnection SEQUENCE +{ + nsapAddress OCTET STRING (SIZE (1..20)), + transportSelector OCTET STRING OPTIONAL +}, +nonStandard NonStandardParameter, +... +} + +MediaList ::= SEQUENCE { + audio BOOLEAN, + video BOOLEAN, + data BOOLEAN, + ... +} + +ChannelAggregationMethod ::= CHOICE { + h221 NULL, + h244 NULL, + iso-iec-13871 NULL, + -- The actual mode of bonding is dynamically selected according + -- to the procedures described in ISO/IEC 13871. + nonStandard NonStandardParameter, + ... +} + +Profile ::= CHOICE { + simpleProfile CHOICE { + +``` + +``` + +-- Basic transfer modes: +speech NULL, -- Simple telephony +telephony-3kHz NULL, -- Rec. G.711 +telephony-7kHz NULL, -- Rec. G.722 +voice-band NULL, -- Modems +frameRelay NULL, + -- T.120-only data profiles (Rec. T.123): +t123-pstn-basic NULL, +t123-psdn-basic NULL, +t123-b-isdn-basic NULL +}, +multimediaProfile SEQUENCE { + profile CHOICE { + h310 NULL, + h320 NULL, + h321 NULL, + h322 NULL, + h323 NULL, + h324 NULL, + h324m NULL, + asvd NULL, + dsvd NULL + }, + t120Data BOOLEAN +}, +dsmccDownloadProfile NULL, +nonStandard NonStandardParameter, +... +} + +ExtendedE164NetworkAddress ::= SEQUENCE { + internationalNumber DiallingString, + subAddress SubAddressString OPTIONAL, + extraDialling ExtraDiallingString OPTIONAL, + ... +} + +TransportAddress ::= SEQUENCE { + nsapAddress OCTET STRING (SIZE (1..20)), + transportSelector OCTET STRING OPTIONAL +} + +GSTNConnection ::= SEQUENCE { + networkAddressExtendedE164NetworkAddress, + ... +} + +ISDNConnection ::= SEQUENCE { + circuitTypes SET OF CHOICE { + digital-64k NULL, + digital-2x64k NULL, + digital-384k NULL, + digital-1536 NULL, + digital-1920k NULL, + multirate-base-64k INTEGER (1..30) -- See Note 1 + }, + networkAddressExtendedE164NetworkAddress, + highLayerCompatibility SEQUENCE { + -- Those are supported code points for IE HLC of the D + -- protocol (Rec. Q.931). + telephony3kHz BOOLEAN, + telephony7kHz BOOLEAN, + videotelephony BOOLEAN, + videoconference BOOLEAN, + +``` + +``` + + audiographic BOOLEAN, + audiovisual BOOLEAN, + multimedia BOOLEAN, + ... + } OPTIONAL, + ... +} + +-- Note 1: digital-2x64k differs from multirate-base-64k +-- with a multiplier value of 2; in the first case +-- the network is requested an 8 kHz integrity with Restricted +-- Differential Time Delay (RDTD); +-- in the second case the network is requested a Time Slot +-- Sequence integrity (see 4.5.5/Q.931) + +CSDNConnection ::= SEQUENCE { + circuitTypes SET OF CHOICE { + digital-56k NULL, + digital-64k NULL + }, + networkAddressExtendedE164NetworkAddress, + ... +} + +PSDNConnection ::= SEQUENCE { + networkAddressCHOICE { + extendedE164NetworkAddress ExtendedE164NetworkAddress, + transportAddress TransportAddress, + nonStandard NonStandardParameter + }, + ... +} + +ATMConnection ::= SEQUENCE { + networkAddress CHOICE { + extendedE164 ExtendedE164NetworkAddress, + nsapAddress TransportAddress, + -- this case is reserved for NSAPs only: the + -- optional transport selector shall never be used + nonStandard NonStandardParameter + }, + maxTransferRate INTEGER (0..MAX) OPTIONAL, + -- in cells per seconds + ... +} + +NetworkConnection ::= CHOICE { + gsnConnection GSTNConnection, + isdnConnection ISDNConnection, + csdnConnection CSDNConnection, + psdnConnection PSDNConnection, + atmConnection ATMConnection, + extendedE164NetworkAddress ExtendedE164NetworkAddress, + -- NOTE - LAN connections and leased + transportAddress TransportAddress, + -- lines (Rec. G.703/G.704) may be covered by one of these + nonStandard NonStandardParameter, + ... +} + +NetworkAddressV2 ::= SET OF SEQUENCE { + networkConnection CHOICE { + singleConnection NetworkConnection, + aggregatedConnections SEQUENCE { + +``` + +``` + + connectionList SET (SIZE(1..30)) OF CHOICE { + isdnConnection ISDNConnection, + csdnConnection CSDNConnection, + ... + }, + aggregationMethods SET OF ChannelAggregationMethod OPTIONAL, + ... + } +}, +profiles SET OF Profile OPTIONAL, +mediaConcerned MediaList OPTIONAL, +... +} + +NodeType ::= ENUMERATED +{ + terminal (0), + multiportTerminal (1), + mcu (2), + ... +} + +NodeProperties ::= SEQUENCE +{ + managementDevice BOOLEAN, + -- Is the node a device such as a reservation system + peripheralDevice BOOLEAN, + -- Is the node a peripheral to a primary node + ... +} + +AsymmetryIndicator ::= CHOICE +{ + callingNode NULL, + calledNode NULL, + unknown INTEGER (0..4294967295) + -- Uniformly distributed 32-bit random number +} + +AlternativeNodeID ::= CHOICE +{ + h243NodeID OCTET STRING (SIZE (2)), + ... +} + +ConferenceDescriptor ::= SEQUENCE +{ + conferenceName ConferenceName, + conferenceNameModifier ConferenceNameModifier OPTIONAL, + conferenceDescription TextString OPTIONAL, + lockedConference BOOLEAN, + passwordInTheClearRequired BOOLEAN, + networkAddress NetworkAddress OPTIONAL, + ..., + defaultConferenceFlag BOOLEAN, + conferenceMode ConferenceMode +} + +NodeRecord ::= SEQUENCE +{ + superiorNode UserID OPTIONAL, + -- Not present only for the Top GCC Provider + nodeType NodeType, + nodeProperties NodeProperties, + +``` + +``` + + nodeName TextString OPTIONAL, + participantsList SEQUENCE OF TextString OPTIONAL, + siteInformation TextString OPTIONAL, + networkAddress NetworkAddress OPTIONAL, + alternativeNodeID AlternativeNodeID OPTIONAL, + userData UserData OPTIONAL, + ..., + nodeCategory NodeCategory OPTIONAL, + networkAddressV2 NetworkAddressV2 OPTIONAL + } + +SessionKey ::= SEQUENCE +{ + applicationProtocolKey Key, + sessionID ChannelID OPTIONAL +} + +ChannelType ::= ENUMERATED +{ + static (0), + dynamicMulticast (1), + dynamicPrivate (2), + dynamicUserId (3) +} + +ApplicationRecord ::= SEQUENCE +{ + applicationActive BOOLEAN, + -- Active/Inactive flag + conductingOperationCapable BOOLEAN, + -- Maximum one per node per session + startupChannel ChannelType OPTIONAL, + applicationUserID UserID OPTIONAL, + -- User ID assigned to the Application Protocol Entity + nonCollapsingCapabilities SET OF SEQUENCE + { + capabilityID CapabilityID, + applicationData OCTET STRING OPTIONAL + } OPTIONAL, + ... +} + +CapabilityID ::= CHOICE +{ + standard INTEGER (0..65535), + -- Assigned by Application Protocol specifications + nonStandard Key +} + +CapabilityClass ::= CHOICE +{ + logical NULL, + unsignedMin INTEGER (0..MAX), -- Capability value + unsignedMax INTEGER (0..MAX), -- Capability value + ... +} + +EntityID ::= INTEGER (0..65535) + +ApplicationInvokeSpecifier ::= SEQUENCE +{ + sessionKey SessionKey, + expectedCapabilitySet SET OF SEQUENCE + { + +``` + +``` + + capabilityID CapabilityID, + capabilityClass CapabilityClass, + ... + } OPTIONAL, +startupChannel ChannelType OPTIONAL, +mandatoryFlag BOOLEAN, + -- TRUE indicates required Application Protocol Entity + ... +} + +RegistryKey ::= SEQUENCE +{ + sessionKey SessionKey, + resourceID OCTET STRING (SIZE (0..64)) +} + +RegistryItem ::= CHOICE +{ + channelID DynamicChannelID, + tokenID DynamicTokenID, + parameter OCTET STRING (SIZE (0..64)), + vacant NULL, + ... +} + +RegistryEntryOwner ::= CHOICE +{ + owned SEQUENCE + { + nodeID UserID, -- Node ID of the owning node + entityID EntityID -- Entity ID of the owning + }, -- Application Protocol Entity + notOwned NULL -- There is no current owner +} + +RegistryModificationRights ::= ENUMERATED +{ + owner (0), + session (1), + public (2) +} + + + -- Part 2: PDU Messages + + +UserIDIndication ::= SEQUENCE +{ + tag INTEGER, + ... +} + +ConferenceCreateRequest ::= SEQUENCE +{ + -- MCS-Connect-Provider request user data + conferenceName ConferenceName, + convenerPassword Password OPTIONAL, + password Password OPTIONAL, + lockedConference BOOLEAN, + listedConference BOOLEAN, + conductibleConference BOOLEAN, + terminationMethod TerminationMethod, + conductorPrivileges SET OF Privilege OPTIONAL, + conductedPrivileges SET OF Privilege OPTIONAL, + nonConductedPrivileges SET OF Privilege OPTIONAL, + +``` + +``` + + conferenceDescription TextString OPTIONAL, + callerIdentifier TextString OPTIONAL, + userData UserData OPTIONAL, + ..., + conferencePriority ConferencePriority OPTIONAL, + conferenceMode ConferenceMode OPTIONAL + } + +ConferenceCreateResponse ::= SEQUENCE +{ + -- MCS-Connect-Provider response user data + nodeID UserID, -- Node ID of the sending node + tag INTEGER, + result ENUMERATED + { + success (0), + userRejected (1), + resourcesNotAvailable (2), + rejectedForSymmetryBreaking (3), + lockedConferenceNotSupported (4), + ... + }, + userData UserData OPTIONAL, + ... +} + +ConferenceQueryRequest ::= SEQUENCE +{ + -- MCS-Connect-Provider request user data + nodeType NodeType, + asymmetryIndicator AsymmetryIndicator OPTIONAL, + userData UserData OPTIONAL, + ... +} + +ConferenceQueryResponse ::= SEQUENCE +{ + -- MCS-Connect-Provider response user data + nodeType NodeType, + asymmetryIndicator AsymmetryIndicator OPTIONAL, + conferenceList SET OF ConferenceDescriptor, + result ENUMERATED + { + success (0), + userRejected (1), + ... + }, + userData UserData OPTIONAL, + ..., + waitForInvitationFlag BOOLEAN OPTIONAL, + noUnlistedConferenceFlag BOOLEAN OPTIONAL +} + +ConferenceJoinRequest ::= SEQUENCE +{ + -- MCS-Connect-Provider request user data as well as + -- MCS-Send-Data on Node ID Channel of Top GCC sent + -- by the receiver of the MCS-Connect-Provider + conferenceName ConferenceNameSelector OPTIONAL, + -- Required when part of MCS-Connect-Provider + conferenceNameModifier ConferenceNameModifier OPTIONAL, + tag INTEGER OPTIONAL, + -- Filled in when sent on Node ID Channel of Top GCC + password PasswordChallengeRequestResponse OPTIONAL, + convenerPassword PasswordSelector OPTIONAL, + callerIdentifier TextString OPTIONAL, + userData UserData OPTIONAL, + ..., + +``` + +``` + + nodeCategory NodeCategory OPTIONAL +} + +ConferenceJoinResponse ::= SEQUENCE +{ + -- MCS-Connect-Provider response user data as well as + -- MCS-Send-Data on Node ID Channel of + -- the receiver of the MCS-Connect-Provider + nodeID UserID OPTIONAL, + -- Node ID of directly connected node only + topNodeID UserID, + -- Node ID of Top GCC Provider + tag INTEGER, + conferenceNameAlias ConferenceNameSelector OPTIONAL, + passwordInTheClearRequired BOOLEAN, + lockedConference BOOLEAN, + listedConference BOOLEAN, + conductibleConference BOOLEAN, + terminationMethod TerminationMethod, + conductorPrivileges SET OF Privilege OPTIONAL, + -- No privilege shall be listed more than once + conductedPrivileges SET OF Privilege OPTIONAL, + -- No privilege shall be listed more than once + nonConductedPrivileges SET OF Privilege OPTIONAL, + -- No privilege shall be listed more than once + conferenceDescription TextString OPTIONAL, + password PasswordChallengeRequestResponse OPTIONAL, + result ENUMERATED + { + success (0), + userRejected (1), + invalidConference (2), + invalidPassword (3), + invalidConvenerPassword (4), + challengeResponseRequired (5), + invalidChallengeResponse (6), + ... + }, + userData UserData OPTIONAL, + ..., + nodeCategory NodeCategory OPTIONAL, + conferenceMode ConferenceMode OPTIONAL +} + +``` + +``` + +ConferenceInviteRequest ::= SEQUENCE +{ + -- MCS-Connect-Provider request user data + conferenceName ConferenceName, + nodeID UserID, -- Node ID of the sending node + topNodeID UserID, -- Node ID of Top GCC Provider + tag INTEGER, + passwordInTheClearRequired BOOLEAN, + lockedConference BOOLEAN, + listedConference BOOLEAN, + conductibleConference BOOLEAN, + terminationMethod TerminationMethod, + conductorPrivileges SET OF Privilege OPTIONAL, + -- No privilege shall be listed more than once + conductedPrivileges SET OF Privilege OPTIONAL, + -- No privilege shall be listed more than once + nonConductedPrivileges SET OF Privilege OPTIONAL, + -- No privilege shall be listed more than once + conferenceDescription TextString OPTIONAL, + callerIdentifier TextString OPTIONAL, + userData UserData OPTIONAL, + ..., +} + +``` + +``` + + conferencePriority ConferencePriority OPTIONAL, + nodeCategory NodeCategory OPTIONAL, + conferenceMode ConferenceMode OPTIONAL + } + +``` + +``` + +ConferenceInviteResponse ::= SEQUENCE +{ + -- MCS-Connect-Provider response user data + result ENUMERATED + { + success (0), + userRejected (1), + ... + }, + userData UserData OPTIONAL, + ... +} + +``` + +``` + +ConferenceAddRequest ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of Top GCC or + -- Node ID Channel of Adding MCU if specified + networkAddress NetworkAddress, + requestingNode UserID, + tag INTEGER, + addingMCU UserID OPTIONAL, + userData UserData OPTIONAL, + ..., + nodeCategory NodeCategory OPTIONAL, + networkAddressV2 NetworkAddressV2 +} + +``` + +``` + +ConferenceAddResponse ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of requester + tag INTEGER, + result ENUMERATED + { + success (0), + invalidRequester (1), + invalidNetworkType (2), + invalidNetworkAddress (3), + addedNodeBusy (4), + networkBusy (5), + noPortsAvailable (6), + connectionUnsuccessful (7), + ... + }, + userData UserData OPTIONAL, + ... +} + +``` + +``` + +ConferenceLockRequest ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of Top GCC + -- No parameters + ... +} + +``` + +``` + +ConferenceLockResponse ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of requester + result ENUMERATED + { + success (0), + invalidRequester (1), + alreadyLocked (2), + ... + }, +} + +``` + +``` + + ... +} + +ConferenceLockIndication ::= SEQUENCE +{ + -- MCS-Uniform-Send-Data on GCC-Broadcast-Channel + -- or MCS-Send-Data on Node ID Channel + -- No parameters + ... +} + +ConferenceUnlockRequest ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of Top GCC + -- No parameters + ... +} + +ConferenceUnlockResponse ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of requester + result ENUMERATED + { + success (0), + invalidRequester (1), + alreadyUnlocked (2), + ... + }, + ... +} + +ConferenceUnlockIndication ::= SEQUENCE +{ + -- MCS-Uniform-Send-Data on GCC-Broadcast-Channel + -- or MCS-Send-Data on Node ID Channel + -- No parameters + ... +} + +ConferenceTerminateRequest ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of Top GCC + reason ENUMERATED + { + userInitiated (0), + timedConferenceTermination (1), + ... + }, + ... +} + +ConferenceTerminateResponse ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of requester + result ENUMERATED + { + success (0), + invalidRequester (1), + ... + }, + ... +} + +ConferenceTerminateIndication ::= SEQUENCE +{ + -- MCS-Uniform-Send-Data on GCC-Broadcast-Channel + reason ENUMERATED + { + userInitiated (0), + timedConferenceTermination (1), + ... + +``` + +``` + + }, + ... +} + +ConferenceEjectUserRequest ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of Top GCC + nodeToEject UserID, -- Node ID of the node to eject + reason ENUMERATED + { + userInitiated (0), + ... + }, + ... +} + +ConferenceEjectUserResponse ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of requester + nodeToEject UserID, -- Node ID of the node to eject + result ENUMERATED + { + success (0), + invalidRequester (1), + invalidNode (2), + ... + }, + ... +} + +ConferenceEjectUserIndication ::= SEQUENCE +{ + -- MCS-Uniform-Send-Data on GCC-Broadcast-Channel + nodeToEject UserID, -- Node ID of the node to eject + reason ENUMERATED + { + userInitiated (0), + higherNodeDisconnected (1), + higherNodeEjected (2), + ... + }, + ... +} + +ConferenceTransferRequest ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of Top GCC + conferenceName ConferenceNameSelector, + -- Name of conference to transfer to + conferenceNameModifier ConferenceNameModifier OPTIONAL, + networkAddress NetworkAddress OPTIONAL, + transferringNodes SET (SIZE (1..65536)) OF UserID OPTIONAL, + password PasswordSelector OPTIONAL, + ..., + networkAddressV2 NetworkAddressV2 OPTIONAL +} + +ConferenceTransferResponse ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of requester + conferenceName ConferenceNameSelector, + -- Name of conference to transfer to + conferenceNameModifier ConferenceNameModifier OPTIONAL, + transferringNodes SET (SIZE (1..65536)) OF UserID OPTIONAL, + result ENUMERATED + { + success (0), + invalidRequester (1), + +``` + +``` + + }, + ... +} + +ConferenceTransferIndication ::= SEQUENCE +{ + -- MCS-Uniform-Send-Data on GCC-Broadcast-Channel + conferenceName ConferenceNameSelector, + -- Name of conference to transfer to + conferenceNameModifier ConferenceNameModifier OPTIONAL, + networkAddress NetworkAddress OPTIONAL, + transferringNodes SET (SIZE (1..65536)) OF UserID OPTIONAL, + -- List of Node IDs, + -- not present if destined for all nodes + password PasswordSelector OPTIONAL, + ..., + networkAddressV2 NetworkAddressV2 OPTIONAL +} + +RosterUpdateIndication ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel or + -- MCS-Uniform-Send-Data on GCC-Broadcast-Channel + fullRefresh BOOLEAN, + -- Conference Roster and all + -- ApplicationProtocol Sessions refreshed + nodeInformation SEQUENCE + { + nodeRecordList CHOICE + { + noChange NULL, + refresh SET (SIZE (1..65536)) OF SEQUENCE + -- One for each node in the conference; + -- no node shall be listed more than once + { + nodeID UserID, -- Node ID of the node + nodeRecord NodeRecord + }, + update SET (SIZE (1..65536)) OF SEQUENCE + -- One for each node changing its node record; + -- no node shall be listed more than once + { + nodeID UserID, -- Node ID of the node + nodeUpdate CHOICE + { + addRecord NodeRecord, + replaceRecord NodeRecord, + removeRecord NULL, + ... + } + }, + ... + }, + rosterInstanceNumber INTEGER (0..65535), + nodesAdded BOOLEAN, + -- Nodes have been added since last instance + nodesRemoved BOOLEAN, + -- Nodes have been removed since last instance + ... + }, + applicationInformation SET (SIZE (0..65535)) OF SEQUENCE + -- One for each Application Protocol Session; + -- all Application Protocol Sessions if full refresh; + -- no Application Protocol Session shall be + -- listed more than once + +``` + +``` + +{ + sessionKey SessionKey, + applicationRecordList CHOICE + { + noChange NULL, + refresh SET (SIZE (0..65535)) OF SEQUENCE + -- One for each node with the + -- Application Protocol Session enrolled; + -- no node shall be listed more than once + + { + nodeID UserID, + -- Node ID of node + entityID EntityID, + -- ID for this Application Protocol Entity at this node + applicationRecord ApplicationRecord + }, + update SET (SIZE (1..65536)) OF SEQUENCE + -- One for each node modifying its Application Record; + -- no node shall be listed more than once + + { + nodeID UserID, + -- Node ID of node + entityID EntityID, + -- ID for this Application Protocol Entity at this node + applicationUpdate CHOICE + { + addRecord ApplicationRecord, + replaceRecord ApplicationRecord, + removeRecord NULL, + ... + } + }, + ... + }, + applicationCapabilitiesList CHOICE + { + noChange NULL, + refresh SET OF SEQUENCE + { + capabilityID CapabilityID, + capabilityClass CapabilityClass, + numberOfEntities INTEGER (1..65536), + -- Number of Application Protocol Entities + -- which issued the capability + ... + }, + ... + }, + rosterInstanceNumber INTEGER (0..65535), + peerEntitiesAdded BOOLEAN, + -- Peer Entities have been added since last instance + peerEntitiesRemoved BOOLEAN, + -- Peer Entities have been removed since last instance + ... +}, +... +} + +``` + +**ApplicationInvokeIndication ::= SEQUENCE** + +``` + +{ + -- MCS-Send-Data or MCS-Uniform-Send-Data + -- on GCC-Broadcast-Channel or Node ID Channel + applicationProtocolEntityList SET (SIZE (1..65536)) OF ApplicationInvokeSpecifier, + destinationNodes SET (SIZE (1..65536)) OF UserID OPTIONAL, + -- List of Node IDs, + +``` + +``` + +-- not present if destined for all nodes +... +} + +RegistryRegisterChannelRequest ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of Top GCC + entityID EntityID, + key RegistryKey, + channelID DynamicChannelID, + ... +} + +RegistryAssignTokenRequest ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of Top GCC + entityID EntityID, + key RegistryKey, + ... +} + +RegistrySetParameterRequest ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of Top GCC + entityID EntityID, + key RegistryKey, + parameter OCTET STRING (SIZE (0..64)), + modificationRights RegistryModificationRights OPTIONAL, + ... +} + +RegistryRetrieveEntryRequest ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of Top GCC + entityID EntityID, + key RegistryKey, + ... +} + +RegistryDeleteEntryRequest ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of Top GCC + entityID EntityID, + key RegistryKey, + ... +} + +RegistryMonitorEntryRequest ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of Top GCC + entityID EntityID, + key RegistryKey, + ... +} + +RegistryMonitorEntryIndication ::= SEQUENCE +{ + -- MCS-Uniform-Send-Data on GCC-Broadcast-Channel + key RegistryKey, + item RegistryItem, + -- Contents: channel, token, parameter, or empty + owner RegistryEntryOwner, + modificationRights RegistryModificationRights OPTIONAL, + ... +} + +RegistryAllocateHandleRequest ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of Top GCC + entityID EntityID, + numberOfHandles INTEGER (1..1024), + ... +} + +``` + +``` + +} + +RegistryAllocateHandleResponse ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of requester + entityID EntityID, + numberOfHandles INTEGER (1..1024), + firstHandle Handle, + result ENUMERATED + { + successful (0), + noHandlesAvailable (1), + ... + }, + ... +} + +RegistryResponse ::= SEQUENCE +{ + -- MCS-Send-Data on Node ID Channel of requester + entityID EntityID, + -- Entity ID of the requesting Application Protocol Entity + primitiveType ENUMERATED + { + registerChannel (0), + assignToken (1), + setParameter (2), + retrieveEntry (3), + deleteEntry (4), + monitorEntry (5), + ... + }, + key RegistryKey, + -- Database index + item RegistryItem, + -- Contents: channel, token, parameter, or vacant + owner RegistryEntryOwner, + modificationRights RegistryModificationRights OPTIONAL, + result ENUMERATED + { + successful (0), + belongsToOther (1), + tooManyEntries (2), + inconsistentType (3), + entryNotFound (4), + entryAlreadyExists (5), + invalidRequester (6), + ... + }, + ... +} + +ConductorAssignIndication ::= SEQUENCE +{ + -- MCS-Uniform-Send-Data on GCC-Broadcast-Channel + conductingNode UserID, + ... +} + +ConductorReleaseIndication ::= SEQUENCE +{ + -- MCS-Uniform-Send-Data on GCC-Broadcast-Channel + -- No parameters + ... +} + +``` + +``` + +ConductorPermissionAskIndication ::= SEQUENCE +{ + -- MCS-Uniform-Send-Data on GCC-Broadcast-Channel + grantFlag BOOLEAN, + -- TRUE to request permission grant, FALSE to release + ... +} + +ConductorPermissionGrantIndication ::= SEQUENCE +{ + -- MCS-Uniform-Send-Data on GCC-Broadcast-Channel + permissionList SEQUENCE (SIZE (0..65535)) OF UserID, + -- Node ID of nodes granted permission + waitingList SEQUENCE (SIZE (1..65536)) OF UserID OPTIONAL, + -- Node ID of nodes waiting for permission + ... +} + +ConferenceTimeRemainingIndication ::= SEQUENCE +{ + -- MCS-Send-Data on GCC-Broadcast-Channel + timeRemaining Time, + nodeID UserID OPTIONAL, + ... +} + +ConferenceTimeInquireIndication ::= SEQUENCE +{ + -- MCS-Send-Data on GCC-Convener-Channel + nodeSpecificTimeFlag BOOLEAN, + -- FALSE for conference-wide, TRUE for node-specific + ... +} + +ConferenceTimeExtendIndication ::= SEQUENCE +{ + -- MCS-Send-Data on GCC-Convener-Channel + timeToExtend Time, + nodeSpecificTimeFlag BOOLEAN, + -- FALSE for conference-wide, TRUE for node-specific + ... +} + +ConferenceAssistanceIndication ::= SEQUENCE +{ + -- MCS-Uniform-Send-Data on GCC-Broadcast-Channel + userData UserData OPTIONAL, + ... +} + +TextMessageIndication ::= SEQUENCE + message TextString, +{ + -- MCS-Send-Data or MCS-Uniform-Send-Data + -- on GCC-Broadcast-Channel or Node ID Channel + ... +} + +RosterRefreshRequest ::= SEQUENCE +{ + nodeID UserID, + nodeCategory NodeCategory, + fullRefresh BOOLEAN, + sendConferenceRoster BOOLEAN OPTIONAL, + applicationList SEQUENCE + { + applicationKeyList SET OF SEQUENCE + { + applicationProtocolKey Key, + nonStandardParameter NonStandardParameter OPTIONAL, + ... + } + } +} + +``` + +``` + + }, + nonStandardParameter NonStandardParameter OPTIONAL, + ... + } OPTIONAL, + sessionList SEQUENCE + { + sessionKeyList SET OF SEQUENCE + { + sessionKey SessionKey, + nonStandardParameter NonStandardParameter OPTIONAL, + ... + }, + nonStandardParameter NonStandardParameter OPTIONAL, + ... + } OPTIONAL, + nonStandardParameter NonStandardParameter OPTIONAL, + ... +} + +FunctionNotSupportedResponse ::= SEQUENCE +{ + request RequestPDU +} + +NonStandardPDU ::= SEQUENCE +{ + data NonStandardParameter, + ... +} + +-- ===== +-- Part 3: Messages sent as MCS-Connect-Provider user data +-- ===== + +ConnectData ::= SEQUENCE +{ + t124IdentifierKey, + -- This shall be set to the value {itu-t recommendation t 124 version(0) 1} + connectPDU OCTET STRING +} + +ConnectGCCPDU ::= CHOICE +{ + conferenceCreateRequest ConferenceCreateRequest, + conferenceCreateResponse ConferenceCreateResponse, + conferenceQueryRequest ConferenceQueryRequest, + conferenceQueryResponse ConferenceQueryResponse, + conferenceJoinRequest ConferenceJoinRequest, + conferenceJoinResponse ConferenceJoinResponse, + conferenceInviteRequest ConferenceInviteRequest, + conferenceInviteResponse ConferenceInviteResponse, + ... +} + +-- ===== +-- Part 4: Messages sent using MCS-Send-Data or MCS-Uniform-Send-Data +-- ===== + +GCCPDU ::= CHOICE +{ + request RequestPDU, + response ResponsePDU, + indication IndicationPDU +} + +``` + +``` + +RequestPDU ::= CHOICE +{ + conferenceJoinRequest ConferenceJoinRequest, + conferenceAddRequest ConferenceAddRequest, + conferenceLockRequest ConferenceLockRequest, + conferenceUnlockRequest ConferenceUnlockRequest, + conferenceTerminateRequest ConferenceTerminateRequest, + conferenceEjectUserRequest ConferenceEjectUserRequest, + conferenceTransferRequest ConferenceTransferRequest, + registryRegisterChannelRequest RegistryRegisterChannelRequest, + registryAssignTokenRequest RegistryAssignTokenRequest, + registrySetParameterRequest RegistrySetParameterRequest, + registryRetrieveEntryRequest RegistryRetrieveEntryRequest, + registryDeleteEntryRequest RegistryDeleteEntryRequest, + registryMonitorEntryRequest RegistryMonitorEntryRequest, + registryAllocateHandleRequest RegistryAllocateHandleRequest, + nonStandardRequest NonStandardPDU, + ... +} + +ResponsePDU ::= CHOICE +{ + conferenceJoinResponse ConferenceJoinResponse, + conferenceAddResponse ConferenceAddResponse, + conferenceLockResponse ConferenceLockResponse, + conferenceUnlockResponse ConferenceUnlockResponse, + conferenceTerminateResponse ConferenceTerminateResponse, + conferenceEjectUserResponse ConferenceEjectUserResponse, + conferenceTransferResponse ConferenceTransferResponse, + registryResponse RegistryResponse, + registryAllocateHandleResponse RegistryAllocateHandleResponse, + functionNotSupportedResponse FunctionNotSupportedResponse, + nonStandardResponse NonStandardPDU, + ... +} + +IndicationPDU ::= CHOICE +{ + userIDIndication UserIDIndication, + conferenceLockIndication ConferenceLockIndication, + conferenceUnlockIndication ConferenceUnlockIndication, + conferenceTerminateIndication ConferenceTerminateIndication, + conferenceEjectUserIndication ConferenceEjectUserIndication, + conferenceTransferIndication ConferenceTransferIndication, + rosterUpdateIndication RosterUpdateIndication, + applicationInvokeIndication ApplicationInvokeIndication, + registryMonitorEntryIndication RegistryMonitorEntryIndication, + conductorAssignIndication ConductorAssignIndication, + conductorReleaseIndication ConductorReleaseIndication, + conductorPermissionAskIndication ConductorPermissionAskIndication, + conductorPermissionGrantIndication ConductorPermissionGrantIndication, + conferenceTimeRemainingIndication ConferenceTimeRemainingIndication, + conferenceTimeInquireIndication ConferenceTimeInquireIndication, + conferenceTimeExtendIndication ConferenceTimeExtendIndication, + conferenceAssistanceIndication ConferenceAssistanceIndication, + textMessageIndication TextMessageIndication, + nonStandardIndication NonStandardPDU, + ... +} + +END + +``` + +# 9 Use of the Multipoint Communication Service + +All GCC communication shall be through the Multipoint Communication Service (MCS) as specified in [ITU-T T.122]. This clause details how GCC makes use of MCS services, channel allocation, token allocation and data priorities. + +## 9.1 MCS services + +GCC assumes the MCS services indicated in Table 9-1. All primitives and parameters marked with an "M" are used by mandatory components of GCC. Items marked with an "O" are used only by optional portions of GCC. + +**Table 9-1 – MCS services used by GCC** + +| Primitives | Use | Parameters | Use | +|------------------------------------|-----|-------------------------|-----| +| MCS-Connect-Provider request | M | Calling Address | O | +| MCS-Connect-Provider indication | M | Calling Domain Selector | M | +| MCS-Connect-Provider response | M | Called Address | O | +| MCS-Connect-Provider confirm | M | Called Domain Selector | – | +| | | Upward/Downward Flag | M | +| | | Domain Parameters | M | +| | | Quality of Service | M | +| | | Result | M | +| | | User Data | M | +| MCS-Disconnect-Provider request | M | Reason | M | +| MCS-Disconnect-Provider indication | M | | | +| MCS-Attach-User request | M | Domain Selector | M | +| MCS-Attach-User confirm | M | Result | M | +| | | User ID | M | +| MCS-Detach-User request | M | Reason | M | +| MCS-Detach-User indication | M | User ID | M | +| MCS-Channel-Join request | M | Channel to Join | M | +| MCS-Channel-Join confirm | M | Result | M | +| MCS-Channel-Leave request | – | Channel to Leave | – | +| MCS-Channel-Leave indication | – | Reason | – | +| MCS-Channel-Convvene request | – | Result | – | +| MCS-Channel-Convvene confirm | – | Channel | – | +| MCS-Channel-Disband request | – | Channel | – | +| MCS-Channel-Disband indication | – | Reason | – | +| MCS-Channel-Admit request | – | Channel | – | +| MCS-Channel-Admit indication | – | Manager User ID | – | +| | | List of User IDs | – | +| MCS-Channel-Expel request | – | Channel | – | +| MCS-Channel-Expel indication | – | List of User IDs | – | +| | | Reason | – | + +**Table 9-1 – MCS services used by GCC** + +| Primitives | Use | Parameters | Use | +|----------------------------------|-----|--------------------|-----| +| MCS-Send-Data request | M | Priority | M | +| MCS-Send-Data indication | M | Channel ID | M | +| | | Sender User ID | M | +| | | Data | M | +| MCS-Uniform-Send-Data request | M | Priority | M | +| MCS-Uniform-Send-Data indication | M | Channel ID | M | +| | | Sender User ID | M | +| | | Data | M | +| MCS-Token-Grab request | O | Token ID | O | +| MCS-Token-Grab confirm | O | Result | O | +| MCS-Token-Inhibit request | O | Token ID | O | +| MCS-Token-Inhibit confirm | O | Result | O | +| MCS-Token-Give request | O | User ID Giving | M | +| MCS-Token-Give indication | M | User ID to Receive | O | +| MCS-Token-Give response | M | Token ID | M | +| MCS-Token-Give confirm | O | Result | M | +| MCS-Token-Please request | O | User ID Requesting | O | +| MCS-Token-Please indication | O | Token ID | O | +| MCS-Token-Release request | O | Token ID | O | +| MCS-Token-Release confirm | O | Result | O | +| MCS-Token-Test request | O | Token ID | O | +| MCS-Token-Test confirm | O | Token Status | O | + +## 9.2 Channel allocation + +GCC reserves two static channels for its exclusive use. One channel, GCC-CHANNEL-0 is joined by all GCC Providers in a conference. Another channel, GCC-CHANNEL-1, is joined only by the Conference Convener. Each GCC Provider also joins the Node ID Channel allocated to it by MCS. Table 9-2 shows the channel usage by GCC. + +**Table 9-2 – GCC channel usage** + +| Channel ID | Type | Mnemonic | Description | +|---------------|--------|------------------------------------|-------------------------------------------------------------------------------------| +| GCC-CHANNEL-0 | Static | GCC-Broadcast-Channel | For communication from any GCC Provider in a conference to all GCC Providers. | +| GCC-CHANNEL-1 | Static | GCC-Convener-Channel | For communication from any GCC Provider in a conference to the Conference Convener. | +| GCC-CHANNEL-2 | Static | GCC-Conventional-Broadcast-Channel | For communication from any GCC Provider in a conference to all GCC Providers. | + +**Table 9-2 – GCC channel usage** + +| Channel ID | Type | Mnemonic | Description | +|---------------|---------|-------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| GCC-CHANNEL-3 | Static | GCC-Counted-Broadcast-Channel | For communication from any Conventional node GCC Provider in a conference to any other Conventional node GCC Provider in the conference. Used to communicate Counted node activity among Conventional nodes. | +| – | Dynamic | Node ID Channel | For communication from any GCC Provider in a conference to the GCC Provider at a particular node. Each node is identified by its Node ID. | + +## 9.3 Token allocation + +GCC reserves a single token for its exclusive use. This token, GCC-TOKEN-0, is used as the Conference Conductorship Token. GCC also reserves tokens 16 384 through 65 535 for use as dynamic tokens which GCC allocates for use by Application Protocol Entities. Table 9-3 shows the token usage by GCC. + +**Table 9-3 – GCC token usage** + +| Token ID | Mnemonic | Description | +|-----------------------|--------------------------------|------------------------------------------------------------------------------------------------------| +| GCC-TOKEN-0 | Conference-Conductorship-Token | Grabbed by a GCC Provider to become the Conference Conductor. | +| 16 384 through 65 535 | Dynamic Tokens | Allocated by GCC for use by Application Protocol Entities using GCC-Registry-Assign-Token primitive. | + +## 9.4 Use of MCS data transmission services + +Table 9-4 summarizes the use of MCS data transmission services (MCS-Send-Data and MCS-Uniform-Send-Data) for each GCCPDU. Listed for each GCCPDU are the type of MCS data service used, the Channel ID, and requested data priority. + +**Table 9-4 – Use of MCS send data for GCCPDUs** + +| GCCPDU | Channel | Send data type | Priority | +|--------------------------|--------------------------------------------|----------------|----------| +| UserIDIndication | Node ID Channel of directly connected node | MCS-Send-Data | Top | +| ConferenceCreateRequest | – | – | – | +| ConferenceCreateResponse | – | – | – | +| ConferenceQueryRequest | – | – | – | +| ConferenceQueryResponse | – | – | – | +| ConferenceJoinRequest | Node ID Channel of Top GCC | MCS-Send-Data | Top | +| ConferenceJoinResponse | Node ID Channel of requester | MCS-Send-Data | Top | +| ConferenceInviteRequest | – | – | – | + +**Table 9-4 – Use of MCS send data for GCCPDUs** + +| GCCPDU | Channel | Send data type | Priority | +|--------------------------------|-------------------------------|----------------------------------------|-----------------| +| ConferenceInviteResponse | – | – | – | +| ConferenceAddRequest | Node ID Channel of Top GCC | MCS-Send-Data | High | +| | Node ID Channel of adding MCU | MCS-Send-Data | High | +| ConferenceAddResponse | Node ID Channel of requester | MCS-Send-Data | High | +| ConferenceLockRequest | Node ID Channel of Top GCC | MCS-Send-Data | High | +| ConferenceLockResponse | Node ID Channel of requester | MCS-Send-Data | High | +| ConferenceLockIndication | GCC-Broadcast-Channel | MCS-Uniform-Send-Data | High | +| | Node ID Channel | MCS-Send-Data | High | +| ConferenceUnlockRequest | Node ID Channel of Top GCC | MCS-Send-Data | High | +| ConferenceUnlockResponse | Node ID Channel of requester | MCS-Send-Data | High | +| ConferenceUnlockIndication | GCC-Broadcast-Channel | MCS-Uniform-Send-Data | High | +| | Node ID Channel | MCS-Send-Data | High | +| ConferenceTerminateRequest | Node ID Channel of Top GCC | MCS-Send-Data | High | +| ConferenceTerminateResponse | Node ID Channel of requester | MCS-Send-Data | High | +| ConferenceTerminateIndication | GCC-Broadcast-Channel | MCS-Uniform-Send-Data | High | +| ConferenceEjectUserRequest | Node ID Channel of Top GCC | MCS-Send-Data | Top | +| ConferenceEjectUserResponse | Node ID Channel of requester | MCS-Send-Data | High | +| ConferenceEjectUserIndication | GCC-Broadcast-Channel | MCS-Uniform-Send-Data | Top | +| ConferenceTransferRequest | Node ID Channel of Top GCC | MCS-Send-Data | High | +| ConferenceTransferResponse | Node ID Channel of requester | MCS-Send-Data | High | +| ConferenceTransferIndication | GCC-Broadcast-Channel | MCS-Uniform-Send-Data | High | +| RosterUpdateIndication | Node ID Channel of recipient | MCS-Send-Data | High | +| | GCC-Broadcast-Channel | MCS-Uniform-Send-Data | High | +| ApplicationInvokeIndication | GCC-Broadcast-Channel | MCS-Send-Data or MCS-Uniform-Send-Data | High | +| | Node ID Channel of recipient | MCS-Send-Data | High | +| RegistryRegisterChannelRequest | Node ID Channel of Top GCC | MCS-Send-Data | High | +| RegistryAssignTokenRequest | Node ID Channel of Top GCC | MCS-Send-Data | High | +| RegistrySetParameterRequest | Node ID Channel of Top GCC | MCS-Send-Data | High | +| RegistryRetrieveEntryRequest | Node ID Channel of Top GCC | MCS-Send-Data | High | +| RegistryDeleteEntryRequest | Node ID Channel of Top GCC | MCS-Send-Data | High | +| RegistryMonitorEntryRequest | Node ID Channel of Top GCC | MCS-Send-Data | High | + +**Table 9-4 – Use of MCS send data for GCCPDUs** + +| GCCPDU | Channel | Send data type | Priority | +|------------------------------------|------------------------------|----------------------------------------|-----------------| +| RegistryMonitorEntryIndication | GCC-Broadcast-Channel | MCS-Uniform-Send-Data | High | +| RegistryAllocateHandleRequest | Node ID Channel of Top GCC | MCS-Send-Data | High | +| RegistryAllocateHandleResponse | Node ID Channel of requester | MCS-Send-Data | High | +| RegistryResponse | Node ID Channel of requester | MCS-Send-Data | High | +| ConductorAssignIndication | GCC-Broadcast-Channel | MCS-Uniform-Send-Data | Top | +| ConductorReleaseIndication | GCC-Broadcast-Channel | MCS-Uniform-Send-Data | Top | +| ConductorPermissionAskIndication | GCC-Broadcast-Channel | MCS-Uniform-Send-Data | High | +| ConductorPermissionGrantIndication | GCC-Broadcast-Channel | MCS-Uniform-Send-Data | Top | +| ConferenceTimeRemainingIndication | GCC-Broadcast-Channel | MCS-Uniform-Send-Data | High | +| ConferenceTimeInquireIndication | GCC-Convener-Channel | MCS-Send-Data | High | +| ConferenceTimeExtendIndication | GCC-Convener-Channel | MCS-Send-Data | High | +| ConferenceAssistanceIndication | GCC-Broadcast-Channel | MCS-Send-Data or MCS-Uniform-Send-Data | High | +| TextMessageIndication | GCC-Broadcast-Channel | MCS-Send-Data or MCS-Uniform-Send-Data | High | +| | Node ID Channel of recipient | MCS-Send-Data | High | +| FunctionNotSupportedResponse | Node ID Channel of requester | MCS-Send-Data | Same as request | +| NonStandardPDU | Not defined | Not defined | Not defined | + +## 9.5 Encoding of PDUs in MCS primitives + +All PDUs defined in this Recommendation are encoded and placed in the data field of one of several possible MCS primitives. These are either MCS-Connect-Provider, MCS-Send-Data, or MCS-Uniform-Send-Data. In any of these cases, the bit string that results from the ASN.1 encoding is placed in the OCTET STRING used by MCS in the order such that for each octet, the leading bit is placed in the most significant bit position, and the trailing bit is placed in the least significant bit position. + +In the case of MCS-Connect-Provider, the PDU itself is not placed in the MCS data parameter directly, but is contained within an enclosing structure defined in 9.6 In this case, the description above applies to the outer structure rather than the PDU itself. + +## 9.6 Format of User Data parameter of MCS-Connect-Provider + +The User Data parameter of the MCS-Connect-Provider and MCS-Disconnect-Provider primitives as used by this Recommendation is of a format which provides unique identification of the MCS Controller (as defined in [ITU-T T.122]). The MCS Controller may either be a standard type (such as one that adheres to this Recommendation), or may be a non-standard type. To distinguish these, the User Data consists of an ASN.1 abstract type which includes an identifier of the type of MCS Controller followed by the PDU itself. The identifier field is of type Key which is a choice of either an Object Identifier, or an H221NonStandardIdentifier. The overall abstract type as well as its components is defined in 8.7. The overall structure is encoded using Packed Encoding Rules (Aligned variant) as defined in [ITU-T X.691]. + +When the MCS Controller adheres to this Recommendation, this header shall be set to the Object Identifier choice with a value {itu-t recommendation t 124 version(0) 1}. + +Within this structure, the PDU is not directly encoded but rather is included in a data field which is of type OCTET STRING. The PDU is separately encoded, also using Packed Encoding Rules (Aligned variant) as with all other PDUs defined in this Recommendation. The resulting encoded bit string is placed into the OCTET STRING in the order such that for each octet, the leading bit is placed in the most significant bit position, and the trailing bit is placed in the least significant bit position. The PDU and the enclosing structure are encoded separately to allow for future Recommendations or non-standard MCS Controllers to use different encoding of the PDUs while providing a uniquely encoded identifier of the MCS Controller type (always to be encoded using Packed Encoding Rules). + +## 9.7 Interpretation of the MCS Domain Selector + +In using the MCS-Connect-Provider primitive, this Recommendation makes the following assumptions in its use of the Domain Selector. + +The Calling Domain Selector always accurately reflects the local Domain Selector which is equal to the Conference ID (which is also used by Application Protocols in making an MCS attachment). + +The Called Domain Selector is never used by this Recommendation. Instead it is assumed that the MCS provider passes MCS-Connect-Provider indications to the Control MCSAP regardless of their contents. It is the role of the GCC Provider to determine if the connection should be established, and if so, which domain the connection should be associated with. This is done slightly differently for the four T.124 primitives which generate MCS-Connect-Provider requests: + +- GCC-Conference-Creat: In this case, there is no domain already in existence prior to reception of the MCS-Connect-Provider indication to which the connection could be attached. On receipt of a valid MCS-Connect-Provider indication, a GCC Provider must establish a new MCS domain and indicate to MCS that this is the domain which the new connection is to be associated with. The Domain Selector is chosen at that time by the GCC Provider as the local Conference ID. The means to perform both of these actions are local matters not specified in [ITU-T T.122]. +- GCC-Conference-Query: In this case, no connection is established since the MCS-Connect-Provider response indicates that the request was user-rejected. As a result, it is not necessary to associate the request to any MCS domain. +- GCC-Conference-Join: In this case, a domain does already exist at the receiving node. If the Join request is accepted by the GCC Provider, the GCC Provider must indicate to the MCS provider which domain the connection is to be associated with. The Conference Name (and Conference Name Modifier) are used by the GCC Provider to determine which domain to indicate. The Domain Selector is the local Conference ID of that conference. The means to indicate the domain to the MCS provider is a local matter not specified in [ITU-T T.122]. + +- GCC-Conference-Invite: In this case, as in the Create case, the receiving node does not already have a domain established. The GCC Provider, if the Invite is accepted, chooses a Conference ID which is to be used as the Domain Selector. The MCS provider must be told of the establishment of this domain at this node, and that the particular connection is to be associated with this domain. As in the case of the Create, the means to perform both of these actions are local matters not specified in [ITU-T T.122]. + +# Annex A + +## Static channel and token ID assignments + +(This annex forms an integral part of this Recommendation) + +## A.1 Static channel ID assignments + +Table A.1 lists the numerical assignment of static channel IDs for the static channels allocated for use by this Recommendation. The numerical assignment of static channel IDs is intended to be centralized in [ITU-T T.120], but is included here until [ITU-T T.120] is completed. + +**Table A.1 – Static Channel ID assignments** + +| Symbolic name | Channel ID | +|---------------|------------| +| GCC-CHANNEL-0 | 1 | +| GCC-CHANNEL-1 | 2 | +| GCC-CHANNEL-2 | 3 | +| GCC-CHANNEL-3 | 4 | + +## A.2 Static token ID assignments + +Table A.2 lists the numerical assignment of static token IDs for the static tokens allocated for use by this Recommendation. The numerical assignment of static token IDs is intended to be centralized in [ITU-T T.120], but is included here until [ITU-T T.120] is completed. + +**Table A.2 – Static token ID assignments** + +| Symbolic name | Token ID | +|---------------|----------| +| GCC-TOKEN-0 | 1 | + +# Annex B + +## Object Identifier assignments + +(This annex forms an integral part of this Recommendation) + +**Table B.1** + +| Object Identifier Value | Description | +|-------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| {itu-t recommendation t 124 version(0) 1} | This Object Identifier is used to indicate the version of this Recommendation in use as the MCS Controller. At this time there is a single standardized version defined. | + +# Annex C + +## Network Address Parameter – Description and use + +(This annex forms an integral part of this Recommendation) + +ASN.1 structure NetworkAddressV2 specified in 8.7 (GCCPDU Definitions) reshapes and enhances structure NetworkAddress. By dissociating the concepts of network types, transfer rates and profiles (or transfer modes) which are mixed together into the flat organization used by structure NetworkAddress, it brings more flexibility in describing a network connection toward a conference node, and solves a certain number of pre-signalling issues not addressed so far. + +NetworkAddressV2 has been added beside NetworkAddress in order to meet backward compatibility with older T.120 implementations not using it. ITU-T intends to maintain NetworkAddressV2 as T.124 evolves, while letting the use of NetworkAddress diminish until it may be removed from the standard. This Annex constitutes an intermediate step toward this point. + +To guarantee interworking between T.120 devices using and not using NetworkAddressV2, the following rules shall be respected by implementations: + +- 1) Any T.120 equipment that conforms to this version of T.124, namely Recommendation T.124 revised – 1998, SHALL make use of NetworkAddressV2 IN CONJUNCTION WITH NetworkAddress. +- 2) Each individual T.124 provider using NetworkAddressV2 is responsible for supplying a NetworkAddress structure that matches the closest as possible features contained in NetworkAddressV2. +- 3) Each individual T.124 provider using NetworkAddressV2 which, at some point, must process and relay a GCCPDU containing network address parameters, and which receives the network address information from a node not making use of NetworkAddressV2, is responsible for adding in the relayed PDU a NetworkAddressV2 that matches the closest as possible the description passed through NetworkAddress (see Note). + +NOTE – A typical example is the conference nodes transfer mechanism described in 8.2.11; when the Top GCC provider uses NetworkAddressV2 and receives the ConferenceTransferRequest PDU from a node that uses NetworkAddress only, it shall produce and insert a NetworkAddressV2 structure in the corresponding ConferenceTransferIndication PDU that it will broadcast on the GCC-Broadcast-Channel channel. + +- 4) T.124 providers receiving GCCPDUs containing a NetworkAddressV2 structure and that do not support it will silently ignore it. + +# **Appendix I** + +## **Relationship of T.120 to H.243 in H.320 conferences** + +(This appendix does not form an integral part of this Recommendation) + +## **I.1 Introduction** + +It is the intent of T.120 is to eventually take over the responsibilities of H.243 for multipoint conference establishment in H.320 audio/video/data conferences. In the meantime, H.243 and T.120 will continue to coexist. This Appendix provides recommendations as to how H.243 and T.120 should relate during the long transitional phase from H.243 to T.120 conference control. + +NOTE – Clause 15/H.243 places normative requirements on terminals and MCUs in this regard. + +## **I.2 Conference selection and Password protection** + +Both T.124 and H.243 provide means of establishing a logical connection from a terminal to a particular conference hosted at an MCU. Both Recommendations also provide a password protection mechanism for verifying the authority of a node to join the desired conference. It is envisioned that both T.124 and H.243 will continue to be used for some time. The following subclauses describe means by which T.124 and H.243 should be used during the conference establishment process. + +The assumption is made that at most one H.243 conference is associated with each T.124 conference and vice versa. Thus, if a terminal joins either one, the choice of the other conference is then predetermined. If this assumption is not valid, then different procedures may apply. + +For the purpose of selecting a conference to join (in the case that the MCU allows such a choice) and for the purpose of password protection, an MCU should choose to use the T.124 or the H.243 mechanisms, but not both. The choice of which mechanism to use may depend on whether the conference is dial-in or dial-out, may be made separately for each MCU port, and may depend on the capabilities of the connecting terminal on each port. In the case of terminals that support T.120, it is preferred that the T.124 mechanisms be used for these purposes rather than the H.243 mechanism. + +### **I.2.1 T.124 conference establishment** + +The MCU may choose to use the T.124 mechanisms for conference establishment for a given terminal. The MCU may, for example, allow the terminal to choose among a list of conferences to join by providing this list in the GCC-Conference-Query response and allowing selection of a conference using the GCC-Conference-Join primitive. The MCU may instead have a predetermined conference that it wishes the connecting terminal to join. In this case, it should set the Default Conference Flag in the GCC-Conference-Query response's corresponding Conference Descriptor to indicate that the connecting terminal should join the indicated conference. In either case, if the MCU requires password protection, the T.124 password protection mechanisms (Password In The Clear Required or Challenge Response Required) should be used to verify that the connecting terminal is authorized to join the conference. + +Alternatively, as may be the case for a prearranged dial-out, if the choice of conference is already determined and password protection is not required, the MCU can decide to take the initiative and to invite the terminal into a T.124 conference by issuing a GCC-Conference-Invite request. In this case, it should set the Wait for Invitation Flag in the GCC-Conference-Query response to indicate that the connecting terminal should not take action to join or create a T.124 conference. + +Once the MCU receives a GCC-Conference-Join-Request with a conference name and the corresponding correct password or decides to take the initiative and to invite a terminal into a T.124 + +conference, the terminal may then start receiving the audio and video associated with the corresponding H.243 conference. + +In this case, the MCU should not use the H.243 mechanism to request a password from the connecting terminal. H.243 may still be used for video control and other functions. + +### **1.2.2 H.243 conference establishment** + +Alternatively, the MCU may choose to use the H.243 mechanism for conference establishment. In this case, if a terminal calls into an MCU, the MCU may use the H.243 password to determine in which conference the terminal belongs. Once a correct H.243 password is supplied, the terminal may start receiving the audio and video associated with the conference. + +Since H.243 provides a password mechanism, the additional requirement of a T.124 conference password in this case is superfluous (assuming that only one T.124 conference is permitted in conjunction with the H.243 conference). The MCU may decide to take the initiative and to invite the terminal into the T.124 conference associated with the H.243 conference by issuing a GCC-Conference-Invite request. If queried by the terminal, the MCU should set the Wait for Invitation Flag in the GCC-Conference-Query response to indicate that the terminal need not take action to join or create a T.124 conference. Alternatively the MCU can wait for the terminal to issue a GCC-Conference-Join request. In this case, if queried by the terminal, the MCU should return a single Conference Descriptor in its GCC-Conference-Query response, with the Default Conference Flag set and the Password In The Clear Required Flag reset. + +Terminals that support T.120 should allow the H.243 password mechanism to be used for conference establishment. This should be considered an interim approach used by MCUs until they support the T.124 conference establishment procedures described in the previous subclause. + +## **1.3 Alternative Node ID** + +The Alternative Node ID of T.124 was envisioned for use with the terminal numbering of H.243, allowing nodes in an audio/video/data conference running both T.120 and H.243 to correlate T.124 conference roster information to H.243 site information. + +When issuing the GCC-Conference-Announce-Presence request, nodes should include their assigned H.243 terminal number in the Alternative Node ID field. If a node's H.243 terminal number is reassigned during a conference, the node should re-issue a GCC-Conference-Announce-Presence request with the new terminal number contained in the Alternative Node ID field. + +NOTE – This requires that each terminal remember the content of the most recently received H.230 C&I code TIA. + +The Alternative Node ID is a two-octet field. The first octet should contain the H.243 MCU ID (M), and the second octet should contain the H.243 Terminal ID (T). + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|---------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.127-200708-I_PDF-E/raw.md b/marked/T/T-REC-T.127-200708-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..0fd45988cd1a6c975c1c52f8d0cb49f6ca33df47 --- /dev/null +++ b/marked/T/T-REC-T.127-200708-I_PDF-E/raw.md @@ -0,0 +1,2276 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**T.127** + +(08/2007) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES +Data protocols for multimedia conferencing + +# --- **Multipoint binary file transfer protocol** + +ITU-T Recommendation T.127 + +## ITU-T T-SERIES RECOMMENDATIONS TERMINALS FOR TELEMATIC SERVICES + +| | | +|-----------------------------------------------------|--------------------| +| Facsimile – Framework | T.0–T.19 | +| Still-image compression – Test charts | T.20–T.29 | +| Facsimile – Group 3 protocols | T.30–T.39 | +| Colour representation | T.40–T.49 | +| Character coding | T.50–T.59 | +| Facsimile – Group 4 protocols | T.60–T.69 | +| Telematic services – Framework | T.70–T.79 | +| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89 | +| Telematic services – ISDN Terminals and protocols | T.90–T.99 | +| Videotext – Framework | T.100–T.109 | +| Data protocols for multimedia conferencing | T.120–T.149 | +| Telewriting | T.150–T.159 | +| Multimedia and hypermedia framework | T.170–T.189 | +| Cooperative document handling | T.190–T.199 | +| Telematic services – Interworking | T.300–T.399 | +| Open document architecture | T.400–T.429 | +| Document transfer and manipulation | T.430–T.449 | +| Document application profile | T.500–T.509 | +| Communication application profile | T.510–T.559 | +| Telematic services – Equipment characteristics | T.560–T.649 | +| Still-image compression – JPEG 2000 | T.800–T.849 | +| Still-image compression – JPEG-1 extensions | T.850–T.899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **ITU-T Recommendation T.127** + +# **Multipoint binary file transfer protocol** + +## **Summary** + +ITU-T Recommendation T.127 defines a protocol to support the interchange of binary file data within an interactive conferencing or group working environment where the T.120 suite of standards is in use. It provides mechanisms to support simultaneous distribution of multiple files, selective distribution of files to a subset of participants and retrieval of files from remote sites. Provision is also made for remote directory access. + +This revised version of T.127 introduces a number of clarifications to the previous version. + +## **Source** + +ITU-T Recommendation T.127 was approved on 29 August 2007 by ITU-T Study Group 16 (2005-2008) under the ITU-T Recommendation A.8 procedure. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +### NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2008 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## CONTENTS + +| | Page | +|----------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 2 | +| 4 Abbreviations..... | 3 | +| 5 Introduction to multipoint file transfer ..... | 3 | +| 6 Multipoint transfer of data – An overview ..... | 4 | +| 6.1 T.127 system model..... | 6 | +| 6.2 Compression ..... | 7 | +| 6.3 Priority..... | 7 | +| 6.4 File preshipping ..... | 7 | +| 7 Baseline MBFT application..... | 7 | +| 8 Description of operation ..... | 8 | +| 8.1 File transfer user application ..... | 8 | +| 8.2 File Transfer Application Resource Manager ..... | 9 | +| 8.3 File Transfer Application Service Element ..... | 9 | +| 8.4 MBFT resources ..... | 10 | +| 8.5 MBFT capabilities ..... | 20 | +| 8.6 Support of additional concurrent file transfers..... | 22 | +| 8.7 Selective file transfer ..... | 23 | +| 8.8 Leaving an MBFT session..... | 24 | +| 8.9 File exchange..... | 24 | +| 8.10 Remote directory listing ..... | 31 | +| 8.11 Conducted mode behaviour ..... | 31 | +| 8.12 Aborting a file transfer ..... | 34 | +| 8.13 Diagnostics ..... | 34 | +| 8.14 Non-standard operations..... | 35 | +| 9 MBFT PDU Definitions ..... | 35 | +| 10 Use of the Multipoint Communication Service ..... | 43 | +| 10.1 Use of MCS data transmission services ..... | 43 | +| 10.2 Channel allocation ..... | 43 | +| 10.3 Token allocation ..... | 44 | +| 10.4 MCS services..... | 45 | +| 11 Use of Generic Conference Control ..... | 46 | +| 11.1 Resource IDs ..... | 47 | + +| | Page | +|----------------------------------------------------|-------------| +| Annex A – Static channel and token assignment..... | 49 | +| Annex B – Object Identifier assignments ..... | 50 | +| Appendix I – File Transfer Examples ..... | 51 | +| Appendix II – MBFT attributes ..... | 57 | + +# ITU-T Recommendation T.127 + +# Multipoint binary file transfer protocol + +# 1 Scope + +This Recommendation defines a protocol to support the interchange of binary files within an interactive conferencing or group working environment where the T.120 suite of standards is in use. It provides mechanisms which facilitate distribution and retrieval of one or more files simultaneously using the primitives provided by [ITU-T T.122] (Multipoint Communications Service). This Recommendation is designed to offer a versatile, light weight protocol which provides the core functionality to allow interworking between applications requiring a basic file transfer capability and also has the flexibility to meet the demands of more sophisticated applications. See Figure 1. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T H.221] ITU-T Recommendation H.221 (2004), *Frame structure for a 64 to 1920 kbit/s channel in audiovisual teleservices*. +- [ITU-T T.35] ITU-T Recommendation T.35 (2000), *Procedure for the allocation of ITU-T defined codes for non-standard facilities*. +- [ITU-T T.120] ITU-T Recommendation T.120 (2007), *Data Protocols for multimedia conferencing*. +- [ITU-T T.122] ITU-T Recommendation T.122 (1998), *Multipoint communication service – Service definition*. +- [ITU-T T.123] ITU-T Recommendation T.123 (2007), *Network-specific data protocol stacks for multimedia conferencing*. +- [ITU-T T.124] ITU-T Recommendation T.124 (2007), *Generic Conference Control*. +- [ITU-T T.125] ITU-T Recommendation T.125 (1998), *Multipoint communication service protocol specification*. +- [ITU-T T.434] ITU-T Recommendation T.434 (1999), *Binary file transfer format for the telematic services*. +- [ITU-T V.42 bis] ITU-T Recommendation V.42 bis (1990), *Data compression procedures for data circuit-terminating equipment (DCE) using error correction procedures*. +- [ITU-T X.680] ITU-T Recommendation X.680 (2002), *Information technology – Abstract Syntax Notation One (ASN.1) – Specification of basic notation*. +- [ITU-T X.691] ITU-T Recommendation X.691 (2002), *Information technology – ASN.1 encoding rules: Specification of Packed Encoding Rules (PER)*. + +[ISO/IEC 13239] ISO/IEC 13239:2002, *Information technology – Telecommunications and information exchange between systems – High-Level Data Link Control (HDLC) procedures.* + +[ISO 8571-2] ISO 8571-2:1988, *Information processing systems – Open Systems Interconnection – File Transfer, Access and Management (FTAM) – Part 2: Virtual filestore definitions.* + +![Figure 1 – Scope of T.127](a71911ad87414271aeb190e0eebcb989_img.jpg) + +``` + + graph TD + UA1[User application s + using both standard and non-standard application protocols] + UA2[User application s + using standard application protocols] + NC[Node controller] + UA3[User application s + using non-standard protocols] + + subgraph ITU_T_Rec_T120_App_Protocols [ITU-T Rec. T.120 application protocol Recommendations] + T127[T.127 File Transfer MBFT] + T126[T.126 Still Image SI] + end + + NSAPE[Non-standard application protocol entities] + + subgraph ITU_T_Rec_T120_Infrastructure [ITU-T Rec. T.120 infrastructure Recommendations] + GCC[Generic Conference Control GCC + ITU-T Rec. T.124] + MCS[Multipoint Communications Service MCS + ITU-T Recs T.122/T.125] + TP[Network specific transport protocols + ITU-T Rec. T.123] + end + + UA1 <--> T127 + UA1 <--> NSAPE + UA2 <--> T127 + UA2 <--> T126 + NC <--> GCC + UA3 <--> NSAPE + T127 <--> MCS + T126 <--> MCS + NSAPE <--> GCC + NSAPE <--> MCS + GCC <--> MCS + MCS <--> TP + +``` + +Figure 1 – Scope of T.127 + +Figure 1 – Scope of T.127 + +### 3 Definitions + +This Recommendation defines the following terms: + +3.1 **acknowledged data channel**: An MCS channel on which files are distributed. Participants have the option of rejecting files offered on an acknowledged data channel. An acknowledged data channel may be *exclusive* (i.e., only the channel creator may send files on it), or *shared* (any participant may send files on it). + +3.2 **broadcast data channel**: An MCS channel on which files are distributed. Participants must receive all files distributed on the channel, discarding the data locally if it is not required. + +3.3 **control channel**: An MCS channel used for the management of file transactions. + +3.4 **file attributes**: The name and other identifiable properties of a file. + +3.5 **FILE-REQUEST**: The token used to ensure that there is at most one outstanding file request on the session control channel MBFT-CONTROL. + +2 ITU-T Rec. T.127 (08/2007) + +- 3.6 FILE-REQUEST(p):** The token used to ensure that there is at most one outstanding file request on the sub-session control channel MBFT-CONTROL(p). +- 3.7 FILE-TRANSMIT:** The token used to ensure that there is at most one file transfer in progress on the session broadcast data channel MBFT-DATA. +- 3.8 FILE-TRANSMIT(p):** The token used to ensure that there is at most one file transfer in progress on the sub-session broadcast data channel MBFT-DATA(p). +- 3.9 FILE-TRANSMIT(n):** The token used to ensure that there is at most one file transfer in progress on acknowledged data channel MBFT-DATA(n). +- 3.10 MBFT-CONTROL:** The session control channel. +- 3.11 MBFT-CONTROL(p):** A sub-session control channel, whose MCS Channel ID is p. +- 3.12 MBFT-DATA:** The session broadcast data channel. +- 3.13 MBFT-DATA(p):** A sub-session broadcast data channel, whose MCS Channel ID is p. +- 3.14 MBFT-DATA(n):** An acknowledged data channel, whose MCS Channel ID is n. +- 3.15 non-standard capability:** A capability that is outside the scope of this Recommendation. Non-standard capabilities must be negotiated before use. +- 3.16 session:** A set of peer Application Protocol Entities. +- 3.17 standard capability:** A capability that is defined within the scope of this Recommendation, but is not required for all MBFT implementations. Standard capabilities must be negotiated before use. +- 3.18 sub-session:** A sub-group of peer Application Protocol Entities within a session. + +# 4 Abbreviations + +This Recommendation uses the following abbreviations: + +| | | +|--------|----------------------------------| +| ARM | Application Resource Manager | +| APE | Application Protocol Entity | +| ASE | Application Service Element | +| GCC | Generic Conference Control | +| GCCSAP | GCC Service Access Point | +| MBFT | Multipoint Binary File Transfer | +| MCS | Multipoint Communication Service | +| MCSAP | MCS Service Access Point | +| PDU | Protocol Data Unit | + +# 5 Introduction to multipoint file transfer + +In order to support group activities such as meetings, conferences, etc. involving physically separated participants, there is a requirement to join together two or more locations. The term multipoint communication simply describes the interconnection of multiple terminals. Multipoint Binary File Transfer (MBFT) enables files to be exchanged interactively between participants within a multipoint environment through use of the underlying network independent Multipoint Communication Service (MCS). + +Specifically, this Recommendation provides flexible and efficient mechanisms to support: + +- Simultaneous distribution of multiple files. +- Broadcasting of files to all participants within a conference. +- Selective distribution of files to a subset of participants. +- Retrieval of files from remote sites. +- Partial retransmission of files following an interruption. +- Remote directory access. + +# 6 Multipoint transfer of data – An overview + +T.127 uses a control/data channel architecture to facilitate simultaneous transfer of one or more binary files. It enables files to be broadcast to all participants within a conference, or to be directed selectively to a subset of sites as a private file transfer. No restrictions are placed on the type of data being transmitted. + +Two types of channels are used within T.127; *control channels* and *data channels*. Control channels are used for managing all aspects of the file transfer (offering files, requesting files), whereas data channels are used exclusively for the transfer of file data. Only one file can be transmitted on each data channel at a time, but additional data channels can be used to allow distribution of multiple files simultaneously. The number of data channels in use at any given time depends on the number of concurrent file transfers in progress. + +A group of file transfer applications communicating with each other are said to be participating in the same file transfer *session*. Each file transfer *session* requires a single control channel and one or more data channels for distribution of files to all participating applications. + +T.127 supports two types of data channel: *broadcast* and *acknowledged*. If a transmitter wishes to mandate that all nodes receive a file it is offering, then it should use the broadcast data channel. All nodes must stay joined to the broadcast data channel for the duration of the file transfer session and are obliged to receive all files distributed on it; if a file is not required, receivers should discard it. If a transmitter wishes to give other nodes the option of rejecting a file, it should offer the file on an acknowledged data channel. In this case, each node must inform the transmitter of whether it requires the data or not, and only those which want the file join the data channel. Multiple concurrent file transfers are supported by use of acknowledged data channels. + +Acknowledged data channels should be used if a transmitter considers that one or more of the parameters in the file header are essential to the operation of the application. For example, an application may require a pathname to be preserved by receivers for future reference. Key parameters are identified when offering the file for distribution; nodes which are unable to support all such parameters must reject the file. + +The creator of an acknowledged data channel may designate it to be *exclusive* (i.e., only the creator may send files on the channel) or *shared* (i.e., any participant may send files on it). + +File transactions on the broadcast channel do not require any handshaking between transmitter and receivers as nodes are obliged to receive all files distributed on this channel. This minimizes latency at the start of file transfers for transactions on the broadcast data channel. Transactions on an acknowledged data channel incur some latency at the start of a file transfer, but may have a better overall performance by avoiding unnecessary distribution of data to sites that do not require it, particularly if such sites are on low bandwidth links. The choice of channel is at the transmitter's discretion and may depend on application, file size, network configuration and number of conference participants. See Figure 2. + +![Diagram of the T.127 conference model showing four nodes connected to a Top MCS provider. Each node has an MBFT, MCSAP, and MCS provider component. The Top MCS provider is connected to all MCS providers via a control channel. Data channels (broadcast and acknowledged) are also shown.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +The diagram illustrates the T.127 conference model with four nodes. Each node consists of an MBFT (Media-Based File Transfer) component, an MCSAP (Media Control Session Application Protocol) component, and an MCS provider component. The nodes are labeled as follows: + +- Current transmitter sourcing files A and B:** This node is shown with folders A and B. It has a solid line (Control channel) and a dashed line (Broadcast data channel for A) connecting its MCS provider to the Top MCS provider. +- Node that does not require file A or file B:** This node has a solid line (Control channel) and a dashed line (Broadcast data channel for A) connecting its MCS provider to the Top MCS provider. It also has a dashed line (Acknowledged data channel for B) connecting its MCS provider to the Top MCS provider. +- Node that requires file A:** This node has a solid line (Control channel) and a dashed line (Broadcast data channel for A) connecting its MCS provider to the Top MCS provider. It also has a dashed line (Acknowledged data channel for B) connecting its MCS provider to the Top MCS provider. +- Node that requires files A and B:** This node has a solid line (Control channel) and a dashed line (Broadcast data channel for A) connecting its MCS provider to the Top MCS provider. It also has a dashed line (Acknowledged data channel for B) connecting its MCS provider to the Top MCS provider. + +The Top MCS provider is connected to all MCS providers via a control channel. The data channels are shown as dashed lines. The legend indicates: + +- Control channel (solid line) +- Broadcast data channel for A (dashed line) +- Acknowledged data channel for B (dashed line) + +T.127(07)\_F-02 + +Diagram of the T.127 conference model showing four nodes connected to a Top MCS provider. Each node has an MBFT, MCSAP, and MCS provider component. The Top MCS provider is connected to all MCS providers via a control channel. Data channels (broadcast and acknowledged) are also shown. + +NOTE 1 – All nodes attach to the control channel and broadcast data channel. + NOTE 2 – Nodes must receive files on the broadcast data channel, whether they require the data or not. + NOTE 3 – Nodes only join an acknowledged data channel if they wish to receive the file currently being offered on it. + +**Figure 2 – T.127 conference model** + +Selective distribution of files to a subset of nodes within a conference can be achieved by creating a private file transfer session, or by establishing a private file transfer *sub-session* within the existing session. + +A sub-session follows the same model as a session by having a single control channel and one or more data channels. See Figure 3. However, it differs from a session in that it is not required to have a broadcast data channel. A sub-session has the same capability set as its parent session and its participants are selected from the participants of the parent session. Sub-sessions have no status within GCC and do not appear in the GCC-Application-Roster. A sub-session does not have a distinct Session ID, but instead operates with the Session ID of the main MBFT session. By avoiding the delay incurred by the enrollment process, sub-sessions allow private interactive file exchanges to be initiated in an expedient manner, at the same time conserving GCC and MCS resources. + +Provision is made for sites to request a file from other nodes to allow information retrieval from databases, bulletin boards, etc. Sufficient information must be provided in the request to allow the sourcing site to uniquely identify the file required. + +![Diagram illustrating the relationship between a sub-session and a session. Four nodes (A, B, C, D) are shown at the top, each with a computer icon. Node A connects to 'User A application 1'. Node B connects to 'User B application 1' and 'User B application 2'. Node C connects to 'User C application 1'. Node D connects to 'User D application 1'. Each application box is connected to a 'File APE' box below it. These 'File APE' boxes are connected to small circles representing sub-sessions. A large oval at the bottom represents the 'Multipoint binary file transfer session', which contains a smaller shaded oval labeled 'Multipoint binary file transfer sub-session'. Arrows indicate the flow of data between applications, File APEs, sub-sessions, and the main session.](d4af765160d04ecef538e5066006dc77_img.jpg) + +T.127(07)\_F-03 + +Diagram illustrating the relationship between a sub-session and a session. Four nodes (A, B, C, D) are shown at the top, each with a computer icon. Node A connects to 'User A application 1'. Node B connects to 'User B application 1' and 'User B application 2'. Node C connects to 'User C application 1'. Node D connects to 'User D application 1'. Each application box is connected to a 'File APE' box below it. These 'File APE' boxes are connected to small circles representing sub-sessions. A large oval at the bottom represents the 'Multipoint binary file transfer session', which contains a smaller shaded oval labeled 'Multipoint binary file transfer sub-session'. Arrows indicate the flow of data between applications, File APEs, sub-sessions, and the main session. + +**Figure 3 – Relationship between a sub-session and session** + +## 6.1 T.127 system model + +An MBFT Session is characterized by the following attributes as illustrated in Figure 4. + +- A single control channel. +- A single broadcast data channel. +- Zero or more acknowledged data channels. +- Zero or more private sub-sessions (to allow file exchange between a selected subset of conference participants). +- A Session ID. + +Each sub-session has the following attributes: + +- A single private control channel. +- Zero or one private broadcast data channels. +- Zero or more private acknowledged data channels. +- No individual Session ID (operates with the Session ID of the main MBFT session). + +Each control channel has a FILE-REQUEST token associated with it (unless the channel creator requires an exclusive right to request files from other sites). + +Each data channel has a FILE-TRANSMIT token associated with it (unless the channel creator requires an exclusive right to transmit files on that channel). + +![Figure 4 – T.127 channel model diagram. The diagram shows a hierarchical structure of MBFT channels. At the top is the 'MBFT Session' box, which contains 'MBFT Channel Resources'. These resources are divided into a 'Minimum configuration' (Control channel and Broadcast data channel) and 'Additional (optional) data channels' (Exclusive acknowledged data channel and Shared acknowledged data channel). Below this is a 'Sub-session' box, which contains 'MBFT channel resources'. These resources are divided into 'Mandatory' (Control channel and Broadcast data channel) and 'Optional data channels (one or more)' (Exclusive acknowledged data channel and Shared acknowledged data channel). The sub-session is part of 'Optional sub-sessions'.](af7916c89a458fdab6c3f443217388ae_img.jpg) + +The diagram illustrates the T.127 channel model structure. It is organized into three main levels: MBFT Session, Sub-session, and Optional sub-sessions. The MBFT Session contains MBFT Channel Resources, which are split into a Minimum configuration (Control channel and Broadcast data channel) and Additional (optional) data channels (Exclusive acknowledged data channel and Shared acknowledged data channel). The Sub-session contains MBFT channel resources, split into Mandatory (Control channel and Broadcast data channel) and Optional data channels (one or more) (Exclusive acknowledged data channel and Shared acknowledged data channel). The Optional sub-sessions are shown as multiple stacked boxes, each containing a Sub-session. + +Figure 4 – T.127 channel model diagram. The diagram shows a hierarchical structure of MBFT channels. At the top is the 'MBFT Session' box, which contains 'MBFT Channel Resources'. These resources are divided into a 'Minimum configuration' (Control channel and Broadcast data channel) and 'Additional (optional) data channels' (Exclusive acknowledged data channel and Shared acknowledged data channel). Below this is a 'Sub-session' box, which contains 'MBFT channel resources'. These resources are divided into 'Mandatory' (Control channel and Broadcast data channel) and 'Optional data channels (one or more)' (Exclusive acknowledged data channel and Shared acknowledged data channel). The sub-session is part of 'Optional sub-sessions'. + +T.127(07)\_F-04 + +**Figure 4 – T.127 channel model** + +## 6.2 Compression + +Compression may be applied to files, subject to successful negotiation; by default files are uncompressed. Proprietary techniques may be identified using the formats specified in [ITU-T T.124], e.g., T.35 country code, nationally assigned code, manufacturer's code, non-standard capability code. Object identifiers may be acquired instead. *De facto* standard compression formats may also be identified via this mechanism. Note that compression applies only to the file data payload and not to the file header. + +## 6.3 Priority + +T.127 can be used as a background task performing bulk data transfer as well as a foreground task for immediate distribution of files. The mode to be used is selected by the transmitting site; medium priority should be used for fast data transfer and low for bulk data transfer. The priority must remain the same throughout the transmission of a file but can differ between successive transactions. + +Management of file transactions on the control channel shall use high priority. + +## 6.4 File preshipping + +In order to minimize file transfer traffic during an interactive conference, files may be preshipped by convening a conference specifically to distribute conference material in advance. This can be an automated process and if receiving sites can identify those files which they wish to receive, file traffic can be kept to a minimum. + +# 7 Baseline MBFT application + +Applications wishing to support the file transfer protocol must be able to join the control channel and send or receive on the broadcast data channel. Table 1 identifies which PDUs must be supported. + +**Table 1 – Support of MBFT PDUs** + +| MBFT PDU | File receive only APE | | File transmit only APE | | File transmit & receive APE | | +|---------------------------------------------|-----------------------|-------------|------------------------|-------------|-----------------------------|-------------| +| | Send PDU | Receive PDU | Send PDU | Receive PDU | Send PDU | Receive PDU | +| File-Offer | – | M | M | M | M | M | +| File-Accept | M | – | – | M | M | M | +| File-Reject | M | – | M | M | M | M | +| File-Request | O | M | – | M | O | M | +| File-Deny | M | O | M | – | M | O | +| File-Error | O | – | – | O | O | O | +| File-Abort | O | – | O | M | O | M | +| File-Start | – | M | M | – | M | M | +| File-Data | – | M | M | – | M | M | +| Directory-Request | O | M | O | M | O | M | +| Directory-Response | M | O | M | O | M | O | +| MBFT-NonStandard | O | O | O | O | O | O | +| MBFT-Privilege-Request | O | O | M | O | M | O | +| MBFT-Privilege-Assign | O | M | O | M | O | M | +| Private-Channel-Join-Invite | O | M | O | M | O | M | +| Private-Channel-Join-Response | M | O | M | O | M | O | +| M Mandatory
O Optional
– Not Required | | | | | | | + +# 8 Description of operation + +A file transfer user application relies on the services of a File Transfer Application Protocol Entity (File APE) to communicate with peer applications at other nodes. The File APE has two components as shown in Figure 5: a File Transfer Application Resource Manager (File ARM) and a File Transfer Application Service Element (File ASE). The ARM provides generic functionality, common to all standardized application protocols, whilst the ASE provides functionality specific to this application protocol to enable interworking of file transfer applications. Note that this is a conceptual model and does not impose any constraints on the structure of actual implementations. + +Each component is described in more detail below: + +## 8.1 File transfer user application + +This is the part of the file transfer application addressing those aspects which have no direct effect on interworking (e.g., user interface) and which may thus be product and platform specific. The influence of the user application is thus local to the site at which it is resident. As such it is outside the scope of this Recommendation. A user application relies on the services of a File Transfer Application Protocol Entity (APE) to communicate with peer applications at other nodes. It does not communicate with MCS or GCC; this is done by the File APE. The user application initiates a file transfer session via its File APE, specifying the application capabilities and session mode. Once the session has been established, all MBFT specific transactions are performed by the File APE on behalf of the user application. + +## 8.2 File Transfer Application Resource Manager + +The File Transfer Application Resource Manager (File ARM) is responsible for managing GCC and MCS resources on behalf of the File ASE. It provides the following services: + +- Responding to indications from GCC (e.g., permission to enroll, invoke). +- Enrolling the File APE with GCC. +- Attaching to an MCS domain to obtain an MCS User ID for the File APE. +- Joining static channels. +- Identifying and joining multicast channels using the GCC Registry and MCS. +- Convening private channels and admitting peer File APEs to such channels. +- Joining any private channels to which the File APE has been admitted. +- Identifying and obtaining tokens from the GCC Registry. +- Deleting entries from the registry associated with any channel it may have created. +- Invoking peer File APEs at other nodes. +- Processing Application Roster reports to determine the negotiated Application Capability list and identity of peer File APEs. + +## 8.3 File Transfer Application Service Element + +The File Transfer Application Service Element (File ASE) provides file transfer functionality to the user application with resources obtained by the File ARM. Its operation is independent of the type (i.e., static or dynamic) and identity of tokens and channels passed to it. The user application specifies whether a broadcast or acknowledged data channel is required. For private transfers to a subset of the conference, a list of MBFT User IDs is also required. + +![Figure 5 – T.127 application model diagram showing the interaction between User application, Node controller, File transfer Application Protocol Entity (file APE), File transfer Application Resource Manager (file ARM), File transfer Application Service Element (file ASE), Generic Conference Control (GCC), and Multipoint Communications Service (MCS).](9b6b5924b48bf2fd5f347f88f06f45b3_img.jpg) + +The diagram illustrates the T.127 application model architecture. At the top is the 'User application' box. Below it is the 'File transfer Application Protocol Entity (file APE)' box, which contains two nested boxes: 'File transfer Application Resource Manager (file ARM)' and 'File transfer Application Service Element (file ASE)'. To the left of the file APE box is the 'Node controller' box. Below the file APE box is the 'Generic Conference Control (GCC) ITU-T Rec. T.124' box, which is connected to the 'Multipoint Communications Service (MCS) ITU-T Recs T.122/T.125' box. The 'Node controller' box has bidirectional arrows connecting it to the 'User application', the 'File transfer Application Protocol Entity (file APE)', and the 'Generic Conference Control (GCC)'. The 'File transfer Application Protocol Entity (file APE)' box has a bidirectional arrow connecting it to the 'User application' and a bidirectional arrow connecting it to the 'Generic Conference Control (GCC)'. The 'File transfer Application Resource Manager (file ARM)' box has a bidirectional arrow connecting it to the 'Generic Conference Control (GCC)'. The 'File transfer Application Service Element (file ASE)' box has a bidirectional arrow connecting it to the 'Multipoint Communications Service (MCS)'. The 'Generic Conference Control (GCC)' box has a bidirectional arrow connecting it to the 'Multipoint Communications Service (MCS)'. The 'Multipoint Communications Service (MCS)' box has a bidirectional arrow connecting it to the 'File transfer Application Service Element (file ASE)'. + +Figure 5 – T.127 application model diagram showing the interaction between User application, Node controller, File transfer Application Protocol Entity (file APE), File transfer Application Resource Manager (file ARM), File transfer Application Service Element (file ASE), Generic Conference Control (GCC), and Multipoint Communications Service (MCS). + +T.127(07)\_F-05 + +**Figure 5 – T.127 application model** + +The File ASE provides the following services: + +- Sending and receiving MBFT PDUs. +- Grabbing and releasing tokens and determining token status using MCS. +- Responding to GCC-Conductor-Assign and Release indications. +- Issuing GCC-Conductor-Permission-Ask requests through the Node Controller. +- Responding to GCC-Conductor-Permission-Grant indications. + +## 8.4 MBFT resources + +A binary file transfer session uses *control channels* for management of file transfers and *data channels* for file distribution. Each control channel has one or more data channels associated with it; each data channel supports one file transfer at a time. + +Every MBFT session has a session control channel (assigned the mnemonic MBFT-CONTROL) and a broadcast data channel (assigned the mnemonic MBFT-DATA), which must be joined by all applications participating in that session. The control channel is used to manage all file transfers on the broadcast data channel. All nodes are obliged to receive files transmitted on the broadcast data channel and discard them if the data is not required. This can lead to an unnecessary degradation in conference performance if any nodes which do not require the data are on low bandwidth links. + +Use of *acknowledged data channels* (assigned the mnemonic MBFT-DATA(n), where n is the MCS Channel ID of the data channel) allows the simultaneous distribution of more than one file. Management of file transfers on these channels is done via the session control channel, but in this case nodes have the option of rejecting files offered to them. This ensures that files are only distributed to those nodes which require them, but at the expense of introducing some latency for each file transfer. + +Selective distribution of files to a subgroup of participants within an existing session may be achieved by opening a *sub-session*. This consists of a private sub-session *control channel* (assigned the mnemonic MBFT-CONTROL(p), where p is the MCS Channel ID of the control channel). This is used to manage file transactions on zero or one *private broadcast data channels* (assigned the mnemonic MBFT-DATA(p), where p is the MCS Channel ID of the data channel) and zero or more *private acknowledged data channels* (assigned the mnemonic MBFT-DATA(n), where n is the MCS Channel ID of the data channel). A separate private control channel is required for each private sub-session. + +Each control channel may have a FILE-REQUEST token which is used to ensure that there is at most one outstanding file request on that channel at any instance. A File ASE requiring a file must grab this token before issuing the request and hold the token until it determines whether another node can supply the file. Dynamic control channels without a FILE-REQUEST token are permitted but only the creator of such a channel may issue file requests on that channel. The token for the session control channel MBFT-CONTROL is assigned the mnemonic FILE-REQUEST; the token for a sub-session control channel MBFT-CONTROL(p) is FILE-REQUEST(p). + +Each data channel may have a FILE-TRANSMIT token which is used to ensure that there is only one file transfer in progress on that data channel at any instance. A transmitting File ASE grabs this token before offering a file for transmission and holds it for the duration of the file transfer, releasing the token after despatching the last block of file data. Dynamic data channels without a FILE-TRANSMIT token are permitted but only the creator of such a channel may send files on that channel. The token for the session broadcast data channel MBFT-DATA is assigned the mnemonic FILE-TRANSMIT, the token for a sub-session broadcast data channel MBFT-DATA(p) is FILE-TRANSMIT(p) whilst the token for acknowledged data channel MBFT-DATA(n) is FILE-TRANSMIT(n). + +Together, these channels and tokens comprise the *resources* available to an MBFT session; they may be either static or dynamic. It is the responsibility of the File Transfer Application Resource Manager (File ARM) to determine the identity of these resources. For any given file transaction, the user application must specify the resources to be used by the File ASE. Static and dynamic resources are treated identically by the File ASE. + +### 8.4.1 MBFT initialization + +An MBFT session may be initiated locally by a user application or remotely through use of the GCC-Application-Invoke mechanism. In both cases, the parameters shown in Table 2 are passed to the File ARM. The action to be taken by the File ARM to identify the initial set of resources to be used for the session is determined by the session mode: + +*Static mode* is used for unrestricted broadcasting of data to the conference. It is the simplest mode of operation as it uses predefined static channels and tokens. Applications can join and leave a static mode session at will. Although the File ASE may be employed by other application protocols simultaneously using different subsets of static channels and tokens, only one static mode of the File ARM is predefined by this Recommendation. + +*Multicast mode* can be used for broadcasting of data when the static session is already in use. It is identical in function to static mode, but uses dynamic resources and so channel and token identities must be assigned via the GCC registry and MCS services by the creator of the multicast session (referred to as the *multicast creator*). All other participants (*multicast members*) may determine channel and token ids via the GCC Registry. Applications can join and leave a multicast session at will. There is no restriction on the number of multicast mode sessions in a conference. + +**Table 2 – File APE parameters** + +| Parameter | Description | +|-------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| SessionMode |

This parameter can have one of the following three values:

static: This value indicates that the File APE should enroll using a Session Key composed of the MBFT object identifier and the sessionID parameter. It shall use the static predefined MBFT-CONTROL & MBFT-DATA channels and static FILE-TRANSMIT and FILE-REQUEST tokens.

dynamic multicast: This value indicates that the File APE should enroll using a Session Key composed of the MBFT object identifier and the sessionID parameter. All channel and token resources are dynamic and are allocated by the creator of the multicast session using the MCS-CHANNEL-JOIN mechanism and GCC Registry mechanism respectively. Members of a multicast session determine token and channel ids via the GCC Registry.

dynamic private: This value indicates that the File APE should enroll using a Session Key composed of the MBFT object identifier and the sessionID parameter.

All token and channel resources are dynamic and are allocated by the Private Convenor File ARM using the GCC Registry mechanism and MCS-CHANNEL-CONVENE mechanism respectively. The File ARM creating the session may then admit to the MBFT-CONTROL and MBFT-DATA channels all peer File APEs whose MCS User Ids are present in the admitList protocol parameter.

A Private Member File ARM must wait for its File APE to be admitted by the convenor of the private MCS channels before attempting to join them. Token identities are conveyed in-band by the channel convenor in the first transaction.

| + +**Table 2 – File APE parameters** + +| Parameter | Description | +|-----------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| sessionID |

This parameter is used to differentiate the resources used by multiple sessions of the protocol that may be in existence simultaneously within the same MCS domain. The MCS Channel ID assigned to the MBFT-CONTROL channel is used as the Session ID, since this is guaranteed to be unique within the conference domain.

The SessionID must be specified if the application wishes to participate in a static session or in an existing multicast or private session. It is omitted if the application wishes to create a new multicast or private session.

| +| admitList |

SessionMode = private and SessionID omitted

List of GCC User IDs corresponding to the Nodes at which File APEs are to be admitted to the privately convened channels.

else

Omitted

| + +*Private mode* is used for selective distribution of files to a subset of participants. It is the responsibility of the File ARM initiating the private session (referred to as the *private convenor*) to obtain tokens and channels using GCC and MCS respectively, and to admit peer File APEs (*private members*) to the channels. The identity of tokens is conveyed in-band, but may also be determined via the GCC Registry. There is no restriction on the number of private mode sessions in a conference. A private member File ARM must wait for its File APE to be admitted to the private channels and for the convenor to assign the tokens to be used for the session. Once the convenor leaves the private session, all remaining participants are expelled. Applications can only join a private session at the invitation of the session convenor. + +In all cases the initial set of resources allows for the transfer of one file at a time. Concurrent transfer of multiple files is outlined in clause 8.6. + +A File APE created in any mode must first establish a GCCSAP to allow it to communicate with the GCC provider at that node. When the node joins a conference, the GCC provider will issue a GCC-Application-Permission-to-Enroll with the Grant/Revoke flag set to Grant. The File ARM must then issue a GCC-Application-Enroll request regardless of whether the user application wishes to enroll at that time. If the user application does not wish to enroll, the File ARM must set the Enroll/Un-enroll flag in the GCC-Application-Enroll request to Un-enroll and specify the conference ID. No other parameters are required. The application may enroll at any time subsequently, unless permission is revoked by receipt of a GCC-Application-Permission-to-Enroll indication with the Grant/Revoke flag set to Revoke. + +If the user application wishes to receive GCC-Application-Roster-Reports on all MBFT sessions in progress before deciding which session to participate in, the File ARM may enroll Inactive, specifying the Session Key without a Session ID. If the user application wishes to declare support of the MBFT protocol without consuming MCS resources, the File ARM may enroll Inactive without an MCS User ID. + +When the user application undertakes to enroll active, the File ARM shall issue an MCS-Attach-User request to the MCS provider, using the Conference ID contained in the GCC-Application-Permission-to-Enroll indication as the Domain Selector. On receipt of a successful MCS-Attach-User confirm in response, the File ARM shall join the User ID channel indicated by issuing an MCS-Channel-Join request. + +### 8.4.2 Static mode + +After obtaining an MCS User ID, the File ARM shall join the MBFT static control and data channels by issuing two MCS-Channel-Join requests, specifying MBFT-CHANNEL-0 and MBFT-CHANNEL-1 as the respective channels to join. Once positive confirmation of joining these channels has been received, the File ARM shall enroll active by issuing a GCC-Application-Enroll request to the GCC provider, with the parameters specified in Table 3. The Active/Inactive flag shall be set to Active, the Session ID shall be specified as part of the Session Key, the Start-Up Channel shall be specified as Static and the full Application Capability list must be provided. See also Figure 6. + +![Sequence diagram showing the static session protocol initiation sequence between Local file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Remote file APE(s).](2b3a967f6ce4f23649be995a353e39f8_img.jpg) + +``` + +sequenceDiagram + participant LFAPE as Local file APE + participant LGCC as Local GCC provider + participant LMCS as Local MCS provider + participant RMCS as Remote MCS provider(s) + participant RGCC as Remote GCC provider(s) + participant RFAPE as Remote file APE(s) + + LFAPE->>LGCC: GCC-Application-Permission-To-Enroll ind. + LGCC->>LMCS: MCS-ATTACH-USER req. + LMCS-->>LFAPE: MCS-ATTACH-USER con. [MBFT User ID = unique new] + LFAPE->>LMCS: MCS-CHANNEL-JOIN req. [Channel ID = MBFT User ID] + LMCS-->>LFAPE: MCS-CHANNEL-JOIN con. + LFAPE->>LMCS: MCS-CHANNEL-JOIN req. [Channel ID = MBFT-CHANNEL-0] + LMCS-->>LFAPE: MCS-CHANNEL-JOIN con. + LFAPE->>LMCS: MCS-CHANNEL-JOIN req. [Channel ID = MBFT-CHANNEL-1] + LMCS-->>LFAPE: MCS-CHANNEL-JOIN con. + LFAPE->>LGCC: GCC-Application-Enroll req. [Active, Session ID] + LGCC-->>LFAPE: GCC-Application-Enroll con. + LFAPE->>RMCS: GCC-Application-Roster-Report ind. + RMCS->>RFAPE: GCC-Application-Roster-Report ind. + + Note over LFAPE, LGCC, LMCS: Obtain MBFT user ID + Note over LFAPE, LMCS: Join MBFT-CONTROL and MBFT-DATA channels + Note over LFAPE, LGCC: Enroll active + +``` + +T.127(07)\_F-06 + +Sequence diagram showing the static session protocol initiation sequence between Local file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Remote file APE(s). + +**Figure 6 – Static session protocol initiation sequence** + +**Table 3 – Parameters for GCC-Application-Enroll Request** + +| Parameter | Contents | +|---------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Conference ID | Provided by GCC-Application-Permission-To-Enroll indication. | +| Session Key | {itu-t recommendation t 127 version(0) 1} and MBFT-SESSION-ID if this File APE parameter was specified. | +| Application User ID | Provided by MCS-Attach-User confirm. | +| Active/Inactive | Active when indicating that the File ARM has joined the MBFT-CONTROL and MBFT-DATA channels and determined any required MBFT token IDs.

Inactive in the case of multicast or private modes when enrolling prior to joining the MBFT-CONTROL and MBFT-DATA channels. | + +**Table 3 – Parameters for GCC-Application-Enroll Request** + +| Parameter | Contents | +|----------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Conducting Operation Flag | Set if the File APE is capable of becoming the session MBFT Conductor in conducted mode, i.e., if it can respond to MBFT-Privilege-Request PDUs. This flag must not be set if the Active/Inactive flag is set to Inactive. | +| Start-Up Channel | This parameter is dependent on the File APE parameters specified in Table 2:
Static if SessionMode = Static
Dynamic Multicast if SessionMode = Dynamic Multicast and sessionID omitted
Dynamic Private if SessionMode = Dynamic Private and sessionID omitted
Omitted otherwise | +| Non-Collapsing Capabilities List | No non-collapsing capabilities are specified by this protocol. This field may include non-standard non-collapsing capabilities specified by the user application. | +| Application Capability List | See Table 7; Omitted if Active/Inactive flag is set to Inactive. | +| Enroll/Unenroll | ENROLL | + +### 8.4.3 Multicast mode + +After obtaining an MCS User ID, the File ARM shall examine the File APE sessionID parameter to determine whether it is to participate in an existing multicast session (as a multicast member) or to create a new one (as a multicast creator). + +If the sessionID parameter is present, the File ARM shall attempt to join the session indicated by issuing a GCC-Application-Enroll request with the Active/Inactive flag set to Inactive and specifying the Session Key with the requisite Session ID. It shall then issue an MCS-Channel-Join request, specifying the Session ID of the chosen session as the Channel ID parameter. This channel is used as the MBFT-CONTROL channel. The File ARM must then identify and join the MBFT-DATA channel by issuing a GCC-Registry-Retrieve-Entry request, using the parameters given in Table 4. On receipt of the resulting GCC-Registry-Retrieve-Entry confirm, the File ARM shall examine the Registry Item parameter. The Channel ID contained in this parameter shall be used as the MBFT-DATA channel and the File ARM shall join it by issuing an MCS-Channel-Join request. + +If it wishes to initiate a file transaction, the File ARM may then identify the FILE-TRANSMIT token to be used for the broadcast data channel by issuing a GCC-Registry-Retrieve-Entry request, using the parameters specified in Table 4. If the result parameter in the GCC-Registry-Retrieve-Entry confirm is 'entry not found', only the session creator is permitted to offer files on the broadcast data channel. The File ARM may also identify the FILE-REQUEST token to be used for the control channel by issuing a GCC-Registry-Retrieve-Entry request. If the result parameter in the GCC-Registry-Retrieve-Entry confirm is 'entry not found', only the session creator is permitted to request files on the control channel. + +**Table 4 – Parameters for GCC-Registry-Retrieve-Entry Request** + +| Parameter | Contents | +|---------------|-------------------------------------------------------------| +| Conference ID | Provided by GCC-Application-Permission-To-Enroll indication | +| Registry Key | Registry Key formed as described in clause 8.4.5. | + +If the File ARM does not wish to initiate a file transaction, it does not need to identify the FILE-TRANSMIT token and FILE-REQUEST token during the enrollment process. Instead, it may determine the IDs of these tokens later from File-Offer or File-RequestPDUs issued by peer File ARMs on the MBFT-CONTROL channel. + +Once all resources required for the session have been determined and channels joined, the File ARM shall issue a GCC-Application-Enroll request with the Active/Inactive flag set to Active, specifying the Session ID as part of the Session Key and providing the full Application Protocol Capability List. See Figures 7 and 8. + +![Sequence diagram showing the Multicast session protocol initiation sequence (member) between Local and Remote entities.](c5655e700cc3e9aac7e9f4f07f30264d_img.jpg) + +The diagram illustrates the Multicast session protocol initiation sequence (member) between Local and Remote entities. The participants are: Local file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Remote file APE(s). The operations are categorized into: Obtain MBFT user ID, Enroll inactive, Join MBFT-CONTROL channel of chosen multicast session, Identify MBFT-DATA channel using the GCC registry, Join MBFT-DATA channel, Identify FILE-TRANSMIT and FILE-REQUEST tokens (optional), and Enroll active. + +``` + +sequenceDiagram + participant LFileApe as Local file APE + participant LGCC as Local GCC provider + participant LMCS as Local MCS provider + participant RMCS as Remote MCS provider(s) + participant RGCC as Remote GCC provider(s) + participant RFileApe as Remote file APE(s) + + Note right of RFileApe: Operation + LGCC->>LFileApe: GCC-Application-Permission-To-Enroll ind. + LFileApe->>LGCC: MCS-ATTACH-USER req. + LGCC->>LFileApe: MCS-ATTACH-USER con. [MBFT User ID = unique new] + Note right of RFileApe: Obtain MBFT user ID + LFileApe->>LMCS: MCS-CHANNEL-JOIN req. [Channel ID = MBFT User ID] + LMCS->>LFileApe: MCS-CHANNEL-JOIN con. + LFileApe->>LGCC: GCC-Application-Enroll req. [Inactive, with Session ID] + LGCC->>LFileApe: GCC-Application-Enroll con. + Note right of RFileApe: Enroll inactive + LGCC->>RGCC: GCC-Application-Roster-Report ind. + RGCC->>RFileApe: GCC-Application-Roster-Report ind. + LFileApe->>LMCS: MCS-CHANNEL-JOIN req. [MBFT-CONTROL Channel ID = Chosen Session ID] + LMCS->>LFileApe: MCS-CHANNEL-JOIN con. + Note right of RFileApe: Join MBFT-CONTROL channel of chosen multicast session + LFileApe->>LGCC: GCC-Registry-Retrieve-Entry req. [MBFT-DATA] + LGCC->>LFileApe: GCC-Registry-Retrieve-Entry con. [MBFT-DATA] + Note right of RFileApe: Identify MBFT-DATA channel using the GCC registry + LFileApe->>LMCS: MCS-CHANNEL-JOIN req. [Channel ID = MBFT-DATA] + LMCS->>LFileApe: MCS-CHANNEL-JOIN con. + Note right of RFileApe: Join MBFT-DATA channel + LFileApe->>LGCC: GCC-Registry-Retrieve-Entry req. [FILE-TRANSMIT] + LGCC->>LFileApe: GCC-Registry-Retrieve-Entry con. [FILE-TRANSMIT] + LFileApe->>LGCC: GCC-Registry-Retrieve-Entry req. [FILE-REQUEST] + LGCC->>LFileApe: GCC-Registry-Retrieve-Entry con. [FILE-REQUEST] + Note right of RFileApe: Identify FILE-TRANSMIT and FILE-REQUEST tokens (optional) + LFileApe->>LGCC: GCC-Application-Enroll req. [Active, with Session ID] + LGCC->>LFileApe: GCC-Application-Enroll con. + Note right of RFileApe: Enroll active + LGCC->>RGCC: GCC-Application-Roster-Report ind. + RGCC->>RFileApe: GCC-Application-Roster-Report ind. + +``` + +T.127(07)\_F-07 + +Sequence diagram showing the Multicast session protocol initiation sequence (member) between Local and Remote entities. + +**Figure 7 – Multicast session protocol initiation sequence (member)** + +![Sequence diagram showing the Multicast session protocol initiation sequence (creator). The diagram involves six participants: Local file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Remote file APE(s). The sequence includes steps for obtaining MBFT user ID, assigning and joining MBFT-CONTROL and MBFT-DATA channels, enrolling inactive, registering MBFT-DATA channel, assigning FILE-TRANSMIT and FILE-REQUEST tokens, and enrolling active.](e69b9188aa2c14ec6b21c83f711fef65_img.jpg) + +``` + +sequenceDiagram + participant LFA as Local file APE + participant LGP as Local GCC provider + participant LMP as Local MCS provider + participant RMP as Remote MCS provider(s) + participant RGP as Remote GCC provider(s) + participant RFA as Remote file APE(s) + + LFA->>LGP: GCC-Application-Permission-To-Enroll ind. + LGP->>LMP: MCS-ATTACH-USER req. + LMP->>LFA: MCS-ATTACH-USER con. [MBFT User ID = unique new] + LFA->>LMP: MCS-CHANNEL-JOIN req. [Channel ID = MBFT User ID] + LMP->>LFA: MCS-CHANNEL-JOIN con. + Note over LFA, LMP: Obtain MBFT user ID + LFA->>LMP: MCS-CHANNEL-JOIN req. [Channel ID = 0] + LMP->>LFA: MCS-CHANNEL-JOIN con. [MBFT-CONTROL Channel ID = unique new] + Note over LFA, LMP: Assign and join MBFT-CONTROL channel + LFA->>LMP: MCS-CHANNEL-JOIN req. [Channel ID = 0] + LMP->>LFA: MCS-CHANNEL-JOIN con. [MBFT-DATA Channel ID = unique new] + Note over LFA, LMP: Assign and join MBFT-DATA channel + LFA->>LGP: GCC-Application-Enroll req. [Inactive, with Session ID] + LGP->>LFA: GCC-Application-Enroll con. + Note over LFA, LGP: Enroll inactive + LFA->>LGP: GCC-Application-Roster-Report ind. + LGP->>RGP: GCC-Application-Roster-Report ind. + RGP->>RFA: GCC-Application-Roster-Report ind. + LFA->>LGP: GCC-Registry-Register-Channel req. [MBFT-DATA] + LGP->>LFA: GCC-Registry-Register-Channel con. + Note over LFA, LGP: Register MBFT-DATA channel + LFA->>LGP: GCC-Registry-Assign-Token req. + LGP->>LFA: GCC-Registry-Assign-Token con. [FILE-TRANSMIT = unique new] + LFA->>LGP: GCC-Registry-Assign-Token req. + LGP->>LFA: GCC-Registry-Assign-Token con. [FILE-TRANSMIT = unique new] + Note over LFA, LGP: Assign FILE-TRANSMIT and FILE-REQUEST tokens (optional) + LFA->>LGP: GCC-Application-Enroll req. [Active, with Session ID] + LGP->>LFA: GCC-Application-Enroll con. + Note over LFA, LGP: Enroll active + LFA->>LGP: GCC-Application-Roster-Report ind. + LGP->>RGP: GCC-Application-Roster-Report ind. + RGP->>RFA: GCC-Application-Roster-Report ind. + +``` + +T.127(07)\_F-08 + +Sequence diagram showing the Multicast session protocol initiation sequence (creator). The diagram involves six participants: Local file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Remote file APE(s). The sequence includes steps for obtaining MBFT user ID, assigning and joining MBFT-CONTROL and MBFT-DATA channels, enrolling inactive, registering MBFT-DATA channel, assigning FILE-TRANSMIT and FILE-REQUEST tokens, and enrolling active. + +**Figure 8 – Multicast session protocol initiation sequence (creator)** + +If the File APE sessionID parameter is omitted, the File ARM shall attempt to create a new session. It shall first issue an MCS-Channel-Join request primitive with Channel ID = 0. The returned MCS-Channel-Join confirm, if successful, contains the assigned Channel ID which is to be used as the MBFT-CONTROL channel. This process is then repeated to assign and join the MBFT-DATA channel. The ARM shall then enroll inactive in this session by issuing a GCC-Application-Enroll request with the Active/Inactive flag set to Inactive, specifying the Session Key with the Session ID, but omitting the Application Capabilities List. Once the File ARM has received a GCC-Application-Roster Report containing an entry corresponding to the new session, the File ARM register the MBFT-DATA channel by issuing a GCC-Registry-Register-Channel request with the parameters given in Table 5. + +**Table 5 – Parameters for GCC-Registry-Register-Channel Request** + +| Parameter | Contents | +|---------------|--------------------------------------------------------------| +| Conference ID | Provided by GCC-Application-Permission-To-Enroll indication. | +| Registry Key | Registry Key formed as described in clause 8.4.5. | +| Channel ID | Channel ID returned in MCS-Channel-Join confirm. | + +The File ARM may then assign FILE-TRANSMIT and FILE-REQUEST tokens by issuing two GCC-Registry-Assign-Token requests using the parameters given in Table 6. If the File ARM requires exclusive access to the broadcast data channel, it need not assign a FILE-TRANSMIT token. If it requires an exclusive right to request files, the File ARM need not assign a FILE-REQUEST token. + +**Table 6 – Parameters for GCC-Registry-Assign-Token Request** + +| Parameter | Contents | +|---------------|--------------------------------------------------------------| +| Conference ID | Provided by GCC-Application-Permission-To-Enroll indication. | +| Registry Key | Registry Key formed as described in clause 8.4.5. | + +Once all resources have been successfully determined, the File ARM shall enroll actively by issuing a GCC-Application-Enroll request with the Active/Inactive flag set to Active, the Start-Up Channel specified as Dynamic Multicast and providing the full Application Protocol Capability List. The MBFT-CONTROL Channel ID is used as the Session ID in the Session Key. + +### 8.4.4 Private mode + +After obtaining an MCS User ID, the File ARM shall examine the File APE sessionID parameter to determine whether it is to participate in an existing private session (as a private member) or to create a new one (as a private convenor). + +If the sessionID parameter is omitted, the File ARM shall attempt to create a new private session. The File ARM shall first issue an MCS-Channel-Convene request in order to obtain a private MBFT-CONTROL channel. If successful, the returned MCS-Channel-Convene confirm contains the ID of the channel allocated. The File ARM must then join this channel by issuing an MCS-Channel-Join request, specifying the channel id returned in the MCS-Channel-Convene confirm. This process must be repeated to assign and join a separate MBFT-DATA channel. The ARM shall then enroll inactive in the new session by issuing a GCC-Application-Enroll request with the Active/Inactive flag set to Inactive, specifying the Session Key with the MBFT-CONTROL channel ID as Session ID and omitting the Application Capabilities List. + +The File ARM may then assign FILE-TRANSMIT and FILE-REQUEST tokens by issuing two GCC-Registry-Assign-Token requests using the parameters given in Table 6. If the File ARM requires exclusive access to the broadcast data channel, it need not assign a FILE-TRANSMIT token. If it requires an exclusive right to request files, the File ARM need not assign a FILE-REQUEST token. + +The File ARM shall then enroll actively by issuing a GCC-Application-Enroll request with the Active/Inactive flag set to Active, the Start-Up Channel specified as Dynamic Private and providing the full Application Protocol Capability List. The MBFT-CONTROL Channel ID is used as the Session ID in the Session Key. + +If there is no active peer File APE at one or more of the nodes that are to be invited to the private session, the File ARM shall issue a GCC-Application-Invoke request, specifying a list of GCC User IDs to be invited or NULL (indicating that all nodes in the conference are to be invited) as the + +Destination Nodes parameter. It shall also specify Dynamic Private as the Start-Up Channel in the Application Protocol entry. + +The convening File ARM must then wait until it has received a GCC-Application-Roster-Report indication containing the MCS User IDs of the File APEs to be invited to the private session (a timeout is recommended in case no MBFT application is initiated at one or more of the invited nodes). The File ARM shall then issue an MCS-Channel-Admit request for both the control and data channels, specifying the MCS User IDs of the File APEs to be invited as the list of MCS User IDs. + +If the File APE sessionID parameter is present, the File ARM shall attempt to join the session indicated by issuing a GCC-Application-Enroll request with the Active/Inactive flag set to Inactive and specifying the Key with the requisite Session ID. It shall then wait until it has received an MCS-Channel-Admit indication from the File ARM at the node convening the private MBFT session. It then attempts to join the channel indicated in this primitive by issuing an MCS-Channel-Join request. A further MCS-Channel-Admit indication will be received from the private session convenor; the private member File ARM must also join the channel indicated in this primitive by issuing an MCS-Channel-Join request. To determine which of the two channels is to be used as the MBFT-CONTROL channel, the File ARM compares both Channel IDs with the Session ID. The Channel ID which matches the Session ID is the MBFT-CONTROL channel. The Channel ID that does not match the Session ID, but has the same channel manager User ID is the corresponding MBFT-DATA channel. When a private member File ARM is remotely invoked, the Session ID (and thus MBFT-CONTROL Channel ID) is obtained from the GCC-Application-Invoke indication. + +Following receipt of a GCC-Application-Roster-Report indication containing the User ID of its File APE, the File ARM shall re-enroll with the Active/Inactive flag set to Active, including the Session ID as part of the Session Key and providing the full Application Protocol Capability List. + +The identities of tokens to be used for the private session are conveyed by the convening File ASE when it initiates the first transaction on the control channel (i.e., in the File-OfferPDU or File-RequestPDU). Private members may individually access the GCC-Registry to determine token identities, but it must be emphasized that this approach is much less efficient. To identify the FILE-TRANSMIT token used with the broadcast data channel, the File ARM shall issue a GCC-Registry-Retrieve-Entry request, using the parameters specified in Table 4. If the result parameter in the GCC-Registry-Retrieve-Entry confirm is 'entry not found', only the session convenor is permitted to offer files on the broadcast data channel. The File ARM may also identify the FILE-REQUEST token to be used for the control channel by issuing a GCC-Registry-Retrieve-Entry request. If the result parameter in the GCC-Registry-Retrieve-Entry confirm is 'entry not found', only the session convenor is permitted to request files on the control channel. See Figure 9. + +![Sequence diagram showing the Private session protocol initiation sequence between Convener file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Member file APE(s). The diagram details the steps for channel establishment, enrollment, and invocation, with operations like 'Convener obtains MBFT user ID', 'Convener convenes MBFT-CONTROL channel', and 'Members enroll active'.](7133ccf78043568ca62ecbcd43628a4a_img.jpg) + +The diagram illustrates the Private session protocol initiation sequence across six participants: Convener file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Member file APE(s). The sequence of operations is as follows: + +- Convener obtains MBFT user ID:** The Convener file APE sends a `GCC-Application-Permission-To-Enroll ind.` to the Local GCC provider, which then sends an `MCS-ATTACH-USER req.` to the Local MCS provider. The Local MCS provider responds with `MCS-ATTACH-USER con. [MBFT User ID = unique new]`. The Convener file APE then sends an `MCS-CHANNEL-JOIN req. [Channel ID = MBFT User ID]` to the Local GCC provider, which responds with `MCS-CHANNEL-JOIN con.`. +- Convener convenes MBFT-CONTROL channel:** The Convener file APE sends an `MCS-CHANNEL-CONVENE req.` to the Local GCC provider, which responds with `MCS-CHANNEL-CONVENE con. [MBFT-CONTROL Channel ID = unique new]`. The Convener file APE then sends an `MCS-CHANNEL-JOIN req. [MBFT-CONTROL]` to the Local GCC provider, which responds with `MCS-CHANNEL-JOIN con.`. +- Convener joins MBFT-CONTROL channel:** The Convener file APE sends an `MCS-CHANNEL-CONVENE req.` to the Local GCC provider, which responds with `MCS-CHANNEL-CONVENE con. [MBFT-DATA Channel ID = unique new]`. The Convener file APE then sends an `MCS-CHANNEL-JOIN req. [MBFT-DATA]` to the Local GCC provider, which responds with `MCS-CHANNEL-JOIN con.`. +- Convener enrolls inactive:** The Convener file APE sends a `GCC-Application-Enroll req. [Inactive, with Session ID]` to the Local GCC provider, which responds with `GCC-Application-Enroll con.`. The Convener file APE then sends a `GCC-Application-Roster-Report ind.` to the Local GCC provider, which responds with `GCC-Registry-Assign-Token req.`. The Convener file APE then sends a `GCC-Registry-Assign-Token con. [FILE-TRANSMIT = unique new]` to the Local GCC provider, which responds with `GCC-Registry-Assign-Token req.`. The Convener file APE then sends a `GCC-Registry-Assign-Token con. [FILE-REQUEST = unique new]` to the Local GCC provider, which responds with `GCC-Application-Enroll req. [Active, with Session ID]`. The Convener file APE then sends a `GCC-Application-Enroll con.` to the Local GCC provider, which responds with `GCC-Application-Roster-Report ind.`. +- Convener enrolls active:** The Convener file APE sends a `GCC-Application-Invoke req. [GCC User IDs, Session ID]` to the Local GCC provider, which responds with `GCC-Application-Invoke con.`. The Convener file APE then sends a `GCC-Application-Invoke ind. [GCC User IDs, Session ID]` to the Remote MCS provider(s), which responds with `MCS-ATTACH-USER req.`. The Remote MCS provider(s) then sends `MCS-ATTACH-USER con. [MBFT User ID = unique new]` to the Remote GCC provider(s), which responds with `MCS-CHANNEL-JOIN req. [Channel ID = MBFT User ID]`. The Remote GCC provider(s) then sends `MCS-CHANNEL-JOIN con.` to the Remote MCS provider(s). +- Members obtain MBFT user ID (not required if node controller re-activates existing inactive file APE):** The Remote MCS provider(s) sends a `GCC-Application-Enroll req. [Inactive, with Session ID]` to the Remote GCC provider(s), which responds with `GCC-Application-Enroll con.`. The Remote MCS provider(s) then sends a `GCC-Application-Roster-Report ind.` to the Remote GCC provider(s), which responds with `GCC-Application-Roster-Report ind.`. +- Convener admits members to MBFT-CONTROL channel:** The Convener file APE sends a `MCS-CHANNEL-ADMIT req. [MBFT-CONTROL, MCS User ID(s)]` to the Local MCS provider, which sends a `MCS-CHANNEL-ADMIT ind. [Channel ID]` to the Remote MCS provider(s). The Remote MCS provider(s) then sends a `MCS-CHANNEL-JOIN req. [MBFT-CONTROL]` to the Remote GCC provider(s), which responds with `MCS-CHANNEL-JOIN con.`. +- Members join MBFT-CONTROL channel:** The Remote MCS provider(s) sends a `MCS-CHANNEL-ADMIT ind. [Channel ID]` to the Remote GCC provider(s), which sends a `MCS-CHANNEL-JOIN req. [MBFT-DATA]` to the Remote MCS provider(s). The Remote MCS provider(s) then sends `MCS-CHANNEL-JOIN con.` to the Remote GCC provider(s). +- Convener admits members to MBFT-DATA channel:** The Convener file APE sends a `MCS-CHANNEL-ADMIT req. [MBFT-DATA, MCS User ID(s)]` to the Local MCS provider, which sends a `MCS-CHANNEL-ADMIT ind. [Channel ID]` to the Remote MCS provider(s). The Remote MCS provider(s) then sends a `MCS-CHANNEL-JOIN req. [MBFT-DATA]` to the Remote GCC provider(s), which responds with `MCS-CHANNEL-JOIN con.`. +- Members join MBFT-DATA channel:** The Remote MCS provider(s) sends a `GCC-Application-Enroll req. [Active, with Session ID]` to the Remote GCC provider(s), which responds with `GCC-Application-Enroll con.`. The Remote MCS provider(s) then sends a `GCC-Application-Roster-Report ind.` to the Remote GCC provider(s), which responds with `GCC-Application-Roster-Report ind.`. +- Members enroll active:** The Remote MCS provider(s) sends a `GCC-Application-Roster-Report ind.` to the Remote GCC provider(s), which responds with `GCC-Application-Roster-Report ind.`. + +NOTE – GCC-Application-Invoke ind is sent to the Node Controller. + +Sequence diagram showing the Private session protocol initiation sequence between Convener file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Member file APE(s). The diagram details the steps for channel establishment, enrollment, and invocation, with operations like 'Convener obtains MBFT user ID', 'Convener convenes MBFT-CONTROL channel', and 'Members enroll active'. + +**Figure 9 – Private session protocol initiation sequence** + +### 8.4.5 Forming Registry Keys + +To determine the identity of a dynamic token or channel via the GCC Registry, a File ARM must form a registry key which consists of the Session Key for the current MBFT session and an MBFT Resource ID. Resource IDs are defined in Tables 29 and 30 for channels and tokens respectively. + +## 8.5 MBFT capabilities + +Capabilities negotiation for file transfer applications is done via the application enrollment mechanism. When a File ARM issues a GCC-Application-Enroll request with the Active/Inactive flag set to Active, it shall indicate the capabilities of its user application in the Application Capabilities List parameter of the request. + +A File APE is notified of the capabilities available within its session by the receipt of a GCC-Application-Roster-Report indication which contains the Application Roster for that session. The Application Roster includes a list of nodes for which a peer File APE has enrolled. For each node, the list contains the GCC User ID of that node and the MCS User ID(s) of the peer File APE(s) at that node. The Application Roster has an instance number and contains flags to indicate whether File APEs have joined or left the session since the previous Application-Roster-Report was issued. It also contains a flag indicating whether the Application Capabilities List has been updated since the last roster and, if so, the new Capabilities List. If a File APE has newly enrolled, the Applications Capabilities List is updated, as this File APE does not have access to previous instances of the list. + +The Application Capabilities List received in the GCC-Application-Roster-Report indication corresponds to the collapsed Application Capabilities Lists of all enrolled peer File APEs, i.e., it includes an entry for each capability which has been declared by any peer File APE. For each entry it includes the Capability ID, the number of peer File APEs (including the local one) which had advertised this capability and, for capabilities in the Unsigned Minimum class, the minimum value of the parameter among all peer File APEs which declared this capability. Table 7 defines the capability list elements for MBFT and the rules for collapsing each element. Note that certain capabilities are specified as being dependent on other capabilities. This means that the capability must not be included in the Application Protocol Capability List unless the capability on which it depends is also included. + +**Table 7 – Application capability list elements** + +| Capability name default value and description | ID | Class | APE Count Rule | Capability value range | Dependency | +|-----------------------------------------------------------------------------------------------------------------------------------------------|----|------------------|----------------|------------------------|------------| +| Maximum file size (default: unlimited)
Each File APE must specify the maximum file data payload in octets that it is capable of receiving. | 1 | Unsigned minimum | > 0 | (65536..MAX) | – | +| Maximum data payload (default: 8 192)
This is the maximum number of octets allowed in the data field of File-Start and File-Data PDUs. | 2 | Unsigned minimum | = ALL | (8193..65536) | – | + +**Table 7 – Application capability list elements** + +| Capability name default value and description | ID | Class | APE Count Rule | Capability value range | Dependency | +|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------|------------------|----------------|------------------------|------------------------------| +| V.42 bis -Compression (default: uncompressed)
This capability is used to negotiate use of V.42 bis compression for file data. File APEs should assert this capability if they are able to receive V.42 bis compressed data. | 3 | Logical | = ALL | – | – | +| V.42 bis -Number-of-Codewords (default: 512)
Specifies the total number of codewords to be used by the V.42 bis compression algorithm. This is an upper bound on V.42 bis parameter P1. V.42 bis does not impose an upper limit on its value. | 4 | Unsigned minimum | = D | (513..65535) | V.42 bis -Compression | +| V.42 bis -Max-String-Length (default: 6)
Specifies the maximum string length input to the V.42 bis encoder. This is an upper bound on V.42 bis parameter P2. | 5 | Unsigned minimum | = D | (7..250) | V.42 bis -Compression | +| Non-standard capability (default: unspecified)
This is used to negotiate non-standard functions, including non-standard compression techniques. Any number of these can appear in the Application Capability List, provided each has a unique Non-Standard Identifier. The interpretation of these capabilities is not defined in this Recommendation. | Non-Standard Identifier | – | – | – | – | +|

APE Count Rule:

> 0 – If the numberOfEntities parameter returned by the GCC-Application-Roster-Report indication for this capability is greater than zero, then the result of the unsigned minimum operation is established, otherwise the default value of the capability is established.

= ALL – The numberOfEntities parameter returned by the GCC-Application-Roster-Report indication for this capability must equal the number of active File APEs enrolled in the current session, otherwise the default value of the capability is established.

= D – If the numberOfEntities parameter returned by the GCC-Application-Roster-Report indication for this capability is equal to the numberOfEntities parameter for the capability on which it depends, then the result of the unsigned minimum operation is established, otherwise the default value of the capability is established.

| | | | | | + +At any time while a File APE is enrolled in a conference, it may receive additional GCC-Application-Roster-Report indication, notifying it of a change in the roster contents. This may be due to new peer File APEs enrolling in the conference, peer File APEs leaving the conference, or peer File APEs having modified their enrollment information. + +A File APE may change its Application Capabilities List at any time by re-enrolling. To do this, the File ARM issues a GCC-Application-Enroll request with the Enroll/Unenroll flag set to Enroll, including the revised Application Capabilities List, and providing all other parameters as included in the initial active enrollment. This may result in a change to the collapsed capability set, in which case all File APEs in the session will receive a GCC-Application-Roster-Report indication. + +Any change in the collapsed capability set of an MBFT session shall not affect transactions already in progress. Changes shall take effect when the next transaction is initiated. + +## **8.6 Support of additional concurrent file transfers** + +Two mechanisms are available to support simultaneous transmission of more than one file in a conference: + +- 1) Create an additional MBFT session using the procedures defined above. +- 2) Create acknowledged data channels within the existing MBFT session. + +For static and multicast modes, multicast or private channels may be used; for private mode, only private channels should be used. Particular care should be exercised in the use of multicast channels as such channels cease to exist when all joined users leave. It is thus recommended that File APEs only attempt to use a multicast channel if they have not left the channel since it was created or since the last transaction on the channel. + +Each acknowledged data channel MBFT-DATA(n) requires its own FILE-TRANSMIT(n) token in order to manage file transactions on the channel, unless use is restricted to the channel creator. + +### **8.6.1 Multicast channels** + +A File ARM wishing to use an acknowledged multicast data channel must first issue an MCS-Channel-Join request with Channel ID = 0. The returned MCS-Channel-Join confirm, if successful, contains the assigned Channel ID. If the data channel is to be a shared acknowledged data channel, the File ARM must then issue a GCC-Registry-Assign-Token request in order to obtain a FILE-TRANSMIT(n) token. The registry key is formed using the process described in clause 8.4.5. The Channel and Token IDs are conveyed to peer File APEs on the MBFT-CONTROL channel when the creator issues a File-Offer PDU (to transmit a file) or a File-Request PDU (to receive a file) for a file transaction on the new data channel. + +### **8.6.2 Private channels** + +A File ARM wishing to use a shared acknowledged private data channel must first issue an MCS-Channel-Convene request. If successful, it shall join the channel assigned in the MCS-Channel-Convene confirm by issuing an MCS-Channel-Join request. The File ARM must then issue a GCC-Registry-Assign-Token request in order to obtain a FILE-TRANSMIT(n) token. The registry key is formed using the process described in clause 8.4.5. + +A File ARM wishing to use an exclusive private data channel must first issue an MCS-Channel-Convene request. It does not need to join this channel (since it will never receive data on the channel), nor does it need to assign a token. + +Once the resources have been successfully assigned, the File ARM shall issue an MCS-Channel-Admit request, specifying the MCS User IDs of the File APEs to be admitted to the channel as the list of MCS User IDs. + +File APEs being admitted to the private data channel will receive an MCS-Channel-Admit indication, and must then attempt to join the channel indicated by issuing an MCS-Channel-Join request. + +The FILE-TRANSMIT(n) Token ID (if applicable) is conveyed to peer File APEs on the MBFT-CONTROL channel when the creator issues a File-Offer PDU (to transmit a file) or a File-Request PDU (to receive a file) for a file transaction on the new data channel. + +## 8.7 Selective file transfer + +Two mechanisms are available to allow distribution of files to a subgroup of participants: + +- 1) Convene a new private session. +- 2) Establish a private sub-session within the existing MBFT session. + +The latter approach is outlined below. Once the communication path has been established, the mechanism used for file exchange is identical to that used for the initial communication path. + +A File ARM wishing to initiate a private file transfer within an existing MBFT session must assign a private control channel and private data channel using MCS services. The File ARM first issues an MCS-Channel-Convene request for the control channel. If this is successful, it issues an MCS-Channel-Join request, specifying the Channel ID returned in the MCS-Channel-Convene confirm. This process is then repeated for the private data channel. The convening File ARM must then issue a Private-Channel-Join-InvitePDU to the MCS User ID of each File APE to be invited to the private channels, specifying the identity of the control and data channels as shown in Table 8. This PDU also indicates whether the data channel mode is broadcast or acknowledged. + +**Table 8 – Private-Channel-Join-InvitePDU** + +| Parameter | Description | +|--------------------|--------------------------------------------------------------------------| +| Control Channel ID | This identifies the private control channel to be joined | +| Data Channel ID | This identifies the private data channel to be joined | +| Mode | This flag is set to TRUE for broadcast mode, FALSE for acknowledged mode | + +The File ARM then invites other File APEs to join the control channel by issuing an MCS-Channel-Admit request, specifying the channel returned in the MCS-Channel-Convene confirm as Channel ID and including the list of File APE MCS User IDs to be invited to the private channel. This process is then repeated for the private data channel. + +A File ARM which receives a Private-Channel-Join-InvitePDU with the Mode flag set to TRUE must attempt to join both the control and data channels indicated in the PDU when it receives the corresponding MCS-Channel Admit indications from the sub-session convenor. It shall then indicate whether both channels were successfully joined by sending a Private-Channel-Join-ResponsePDU to the channel convenor, with the Result parameter set accordingly. + +A File ARM which receives a Private-Channel-Join-InvitePDU with the Mode flag set to FALSE must attempt to join the control channel indicated in the PDU when it receives the corresponding MCS-Channel Admit indication from the sub-session convenor. It may optionally join the acknowledged data channel at this time. The File ARM shall then indicate whether the control channels was successfully joined by sending a Private-Channel-Join-ResponsePDU to the channel convenor, with the Result parameter set accordingly. + +Once the sub-session convenor has received a Private-Channel-Join-ResponsePDU from each of the File APEs invited to the sub-session, it may begin its file transactions. A timeout is recommended in case one or more of the File APEs fail to respond. See Table 9. + +**Table 9 – Private-Channel-Join-ResponsePDU** + +| Parameter | Description | +|------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Channel ID | This identifies the private control channel which the File APE has been invited to join. | +| Result |

If the Mode flag in the corresponding Private-Channel-Join-Invite PDU was set to TRUE, this parameter indicates whether or not the attempt to join the private control and broadcast data channel was successful.

If the Mode flag in the corresponding Private-Channel-Join-Invite PDU was set to FALSE, this parameter indicates whether or not the attempt to join the private control channel was successful.

| + +Once the convening File ARM has received Private-Channel-Join-ResponsePDU from all invited File APEs, it may allow its File ASE to use the channel. The File ARM should monitor the Application Roster in case any of the invited File APEs leave the session prematurely, and should have a timeout in case any of the File APEs fail to issue a Private-Channel-Join-ResponsePDU. + +The convening File ARM may obtain a FILE-TRANSMIT(n) token and FILE-REQUEST(n) token at any time before the File ASE needs to use the private channels. This is done by issuing two GCC-Registry-Assign-Token requests in succession forming the registry key as described in clause 8.4.5. + +Note that the first transaction must be initiated by the channel manager as the identity of any tokens to be used with the private channel is conveyed in-band in the first File-Offer or File-Request PDU. + +NOTE – The convening file ARM should exercise caution when expelling members from or disbanding a private data channel, since MCS may expel receiving File APE's from the channel before all File-Data PDUs have been delivered. + +## 8.8 Leaving an MBFT session + +If an application wishes to leave an MBFT session, its File ARM shall issue a GCC-Application-Enroll request with the Enroll/Unenroll flag set to Unenroll. No other parameters are required. + +If, at any time, the File ARM receives a GCC-Application-Roster-Report indication in which it is no longer included (i.e., its MBFT User ID is absent), the File ARM shall issue an MCS-Detach-User request immediately to detach from the specified conference. The application is no longer considered to be enrolled in the conference at this time but may attempt to re-enroll in the conference by issuing a GCC-Application-Enroll request. + +If, at any time, the File ARM receives a GCC-Application-Permission-To-Enroll indication with the Grant/Revoke flag set to Revoke, it shall issue an MCS-Detach-User request immediately to detach from the specified conference. The application is no longer considered to be enrolled in the conference at this time and shall not attempt to re-enroll. + +## 8.9 File exchange + +This subclause considers MBFT transactions initiated by either a sending site or a receiving site. File transactions are performed by the File Transfer Application Service Element (File ASE). + +### 8.9.1 Transmitter invoked operation + +A File ASE wishing to transmit a file must first grab the FILE-TRANSMIT token associated with the data channel to prevent other File ASEs from attempting to send data to the channel at the same time. If there is no token associated with the data channel, then only the channel creator may attempt to send files on it. If the token is held by another File ASE (indicating that a file transfer is in progress), then the File ASE wishing to transmit may either wait until it is released, or attempt to use another data channel. Alternatively, the File ASE may request the token from the current + +transmitter by issuing an MCS-Token-Please request primitive, specifying the Token ID of the FILE-TRANSMIT token as Token ID. A File ASE receiving an MCS-Token-Please indication primitive whilst it is transmitting a file may choose to ignore it, or may offer the FILE-TRANSMIT token to the requesting File ASE at the end of the file transfer by issuing an MCS-Token-Give request, specifying the MCS User ID of the requesting File ASE as User id to receive token and the FILE-TRANSMIT Token ID as Token id. On receipt of an MCS-Token-Give indication, the requesting File ASE shall issue an MCS-Token-Give response primitive with result parameter 'rt-successful' or 'rt-user-rejected', depending on whether the File ASE still requires the token or not. If the result is 'rt-successful', the File ASE may assume that it has possession of the token. + +Once the File ASE is in possession of the FILE-TRANSMIT token (or is the creator of an exclusive acknowledged data channel), it offers the file to all intended recipients on the control channel by issuing a File-OfferPDU. The contents of the File-OfferPDU are defined in Table 10. For file transfers on the broadcast data channel, the Ack flag must be set to FALSE to indicate that no acknowledgement is required. For file transfers on acknowledged data channels, the Ack flag must be set to TRUE to indicate that receiving File ASEs must signal whether or not they wish to accept the data. Sufficient information must be conveyed in the File Header parameter to uniquely identify the file and enable receivers to determine whether it is required. It is up to the transmitting File ASE to decide whether to transmit all or a subset of the T.434 parameters available for the file. It is recommended that any parameters deemed to be important to the application by the transmitter are included in the File-OfferPDU. If a transmitter wishes to verify whether receivers are able to support such parameters, it should use an acknowledged data channel for the transaction. The method of determining whether a file is needed is a local implementation issue; the application may determine automatically whether a file is already present, or may require interaction with an operator. + +File ASEs receiving a File-Offer with the Ack flag set to TRUE and wishing to receive the offered file must join the data channel indicated before sending back a confirmation (File-Accept – Table 11) to the transmitter. File ASEs not wishing to receive the file reply with a negative acknowledgement (File-Reject – Table 12) do not join the data channel. Similarly, File ASEs which are unable to support one or more of the parameters included in the File Header should reject the offer. If a File ASE which does not require a file is joined to the data channel when it receives the File-Offer, it must leave the channel by issuing an MCS-Channel-Leave request. If a File ASE is unable to support further concurrent file transfers, it should either delay its response until the file transfer is complete or issue a File-Reject. Only File ASEs included in the Application Roster instance specified in the File-OfferPDU may respond, so that the transmitting File ASE knows how many acknowledgements to accept. File ASEs not included in the specified Application Roster instance must ignore the File-Offer. + +File ASEs receiving a File-Offer with the Ack flag set to FALSE must be prepared to receive data on the broadcast data channel immediately. If the file is not required, the File ASE must either discard incoming data or leave the session. + +**Table 10 – File-OfferPDU** + +| Parameter | Description | +|------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| File Header | This parameter uses the T.434 file header structure and should include sufficient information to allow intending recipients to determine whether the file is required. File name and size are suggested as a minimum set. | +| Data Channel ID | This identifies the channel on which the file will be transmitted. | +| File Handle | This is a unique handle used to reference the file throughout the file transfer operation. It need only be locally unique at the transmitting File APE. | +| Roster Instance | Application Roster Instance Number as returned in the most recently received GCC-Application-Roster-Report indication. Only File APEs which are enrolled active in the identified roster may respond to this PDU. This field is only included if the Ack flag is set to TRUE. File APEs may need to wait to receive the corresponding roster report indication before they can generate a reply. | +| FILE-TRANSMIT Token ID | This identifies the token used to regulate file transmission on the channel specified by the Data Channel ID parameter. If the token is omitted, then only the creator of the data channel is permitted to send files on that channel. If a FILE-TRANSMIT token has been assigned to the data channel it must be included. | +| FILE-REQUEST Token ID | This identifies the token used to regulate file requests. If the token is omitted, then only the creator of the control channel is permitted to issue File-RequestPDUs. If a FILE-REQUEST token has been assigned to the control channel it must be included. | +| File Request Handle | This is a locally unique handle used to reference a file request. It shall be set to the same value as the handle in the corresponding File-Request PDU if the File-Offer is being generated in response to a File-Request, otherwise the handle is omitted. | +| MBFT User ID | This parameter is omitted unless the File-Offer is generated in response to a File-Request, in which case it is used to identify the File APE that issued the File-Request PDU. | +| Compression Specifier | This optional field specifies the compression technique (if any) applied to the data payload of File-Start and File-DataPDUs. | +| Compressed Filesize | This optional parameter is the number of octets in the data payload after compression has been applied. | +| Ack Flag | This flag is set to TRUE if the file is to be sent on an acknowledged data channel, requiring the File-OfferPDU to be acknowledged by all receiving File APEs. If the flag is set to FALSE, the file will be transmitted on the broadcast data channel and no acknowledgement is required. | + +**Table 11 – File-AcceptPDU** + +| Parameter | Description | +|------------------|-------------------------------------------------------------------------------------------------------------------------------------------| +| File Handle | This is a unique handle used to reference the file throughout the file transfer operation. Its value is obtained from the File-Offer PDU. | + +**Table 12 – File-RejectPDU** + +| Parameter | Description | +|-------------|-------------------------------------------------------------------------------------------------------------------------------------------| +| File Handle | This is a unique handle used to reference the file throughout the file transfer operation. Its value is obtained from the File-Offer PDU. | +| Reason | This parameter is used to inform the transmitter why the intended recipient is unable or does not wish to receive the file offered. | + +If the file is to be distributed on the broadcast data channel, the transmitting File ASE may start to send the file on this channel immediately after despatching the File-OfferPDU, otherwise it must wait until it has received an acknowledgement from all File ASEs joined to the control channel. In the latter case, the transmitter should monitor the application roster to determine which sites are currently connected, since File APEs may have left the control channel after the File-OfferPDU was issued. It is recommended that a timeout should be used to prevent File ASEs which fail to respond from locking the application. No timeout values are specified in this protocol specification; they should be sufficiently large to allow for network latencies and user response times. + +Files are transported in a File-StartPDU followed by zero or more File-DataPDUs (see Tables 13 and 14). Note that the File-StartPDU contains a T.434 header. This is included to ensure that the entire file structure (header plus data) is transported as a single entity and also because the information provided in the File-OfferPDU may only be a subset of the header. The EOFflag is used to indicate the end of file. + +**Table 13 – File-StartPDU** + +| Parameter | Description | +|-----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| File Header | This parameter uses the T.434 file header structure and should include all fields defined in the source file, irrespective of whether they were included in the preceding File-OfferPDU. | +| File Handle | This is a unique handle used to reference the file throughout the file transfer operation. It shall be set to the same value as the handle in the File-OfferPDU corresponding to this transfer. | +| EOF Flag | This flag is set to TRUE to indicate end of file. | +| CRC Flag | This indicates whether the last File-DataPDU (or File-StartPDU if the EOF flag is set to TRUE) contains a cyclic redundancy check. | +| Compression Specifier | This optional field specifies the compression technique (if any) applied to the data payload of File-Start and File-DataPDUs. | +| Compressed Filesize | Number of octets in the compressed file, excluding the header. | +| Data Offset | This parameter specifies the starting offset in octets from the beginning of the file data (so zero denotes the origin). | +| Data | The maximum number of octets of binary file data which can be included in this field is negotiated via the capability exchange mechanism. | +| CRC Check | A 32-bit cyclic redundancy check is included in the File-Start PDU if the CRC flag is set to TRUE and either a cumulative CRC is being used or the EOF flag is set to TRUE. | + +**Table 14 – File-DataPDU** + +| Parameter | Description | +|-------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| File Handle | This is a unique handle used to reference the file throughout the file transfer operation. It shall be set to the same value as the handle in the File-OfferPDU corresponding to this transfer. | +| EOF Flag | This flag is set to TRUE in the last File-DataPDU to indicate end of file. | +| Abort Flag | The abort flag is set to TRUE if the file transfer is terminated abnormally, either as a result of conductor intervention or at the transmitter's volition. No further File-DataPDUs will be sent in the current transmission after a File-DataPDU with the Abort flag set to TRUE. | +| Data | The maximum number of octets of binary file data which can be included in this field is negotiated via the capability exchange mechanism. | +| CRC Check | A 32-bit cyclic redundancy check is included in the File-Data PDU if the CRC flag was set to TRUE in the corresponding File-Start and either a cumulative CRC is being used or the EOF flag is set to TRUE. | + +Although the T.120-series provides reliable data transfer, some user applications may have an additional requirement to validate the data by using a Cyclic Redundancy Check (CRC). T.127 allows the possibility for transmitters to optionally include a CRC with the file data. This may either be a single CRC included in the last File-DataPDU (or File-Start PDU if the data can be transported in a single PDU), or a cumulative CRC included in the File-StartPDU and all subsequent File-DataPDUs. The presence of a CRC is indicated by setting the CRC flag in the File-StartPDU. Receivers may ignore CRCs if they are not required by the user application. The method of calculating the CRC is illustrated in Figure 10. Octets of data are input to the CRC calculation sequentially, low order bit first. + +The CRC is reset at the start of each file transfer and is calculated from the file data payload of File-Start and File-Data PDUs using the 32-bit frame checking sequence defined in [ISO/IEC 13239]. If the file data is compressed, the CRC applies to the compressed data and not the source data. + +If V.42 *bis* compression is applied to the file data payload, the encoder is initialized at the beginning of the file and processes data payload octets continuously until the end of the file. The encoder is not reset at the end of each PDU. + +On completion of the transfer of each file, File ASEs must remain joined to both control and data channels to avoid the need to leave and re-join for subsequent operations. However, if a File ASE is joined to an acknowledged data channel and is subsequently offered a file which it does not require, it must leave the data channel before sending back a File-Reject. + +When the transmitting node has despatched the last File-DataPDU, it should release the FILE-TRANSMIT token (if present) by issuing an MCS-Token-Release request to allow other sites to initiate file transmissions on the data channel. If the transmitter had previously received an MCS-Token-Please during the transfer, it may instead offer the token to the requesting File ASE by issuing an MCS-Token-Give request. If MCS-Token-Please indications have been received from more than one File ASE, it is a local matter to decide which to respond to. + +![Figure 10 – Calculation of CRC. The diagram illustrates two methods of CRC calculation: (a) Single CRC sent at end of file transfer and (b) Cumulative CRC. In (a), data is sent in PDUs (File-start, Data 1, Data 2, Data 3, Data 4, Data 5, CRC) and a single CRC is calculated at the end. In (b), each PDU contains its own CRC, and the CRC is calculated cumulatively for each segment.](f9c64800d9bace9b4315646d1057be3c_img.jpg) + +The diagram illustrates two methods of CRC calculation: + +**a) Single CRC sent at end of file transfer** + +This method shows a sequence of PDUs: File-start, Data 1, Data 2, Data 3, Data 4, Data 5, and CRC. A single 'Calculate CRC' block is positioned below the data segments, with arrows indicating that it processes all data from Data 1 to Data 5 to produce the final CRC value. + +**b) Cumulative CRC** + +This method shows a sequence of PDUs, each containing File-start, Data (Data 1 to Data 5), and its own CRC. Below each data segment is a 'Calculate CRC' block. Arrows indicate a cumulative process where the CRC of one segment is used as input for the next segment's calculation. On the left, labels CRC1 through CRC5 are aligned with the respective 'Calculate CRC' blocks. + +T.127(07)\_F-10 + +Figure 10 – Calculation of CRC. The diagram illustrates two methods of CRC calculation: (a) Single CRC sent at end of file transfer and (b) Cumulative CRC. In (a), data is sent in PDUs (File-start, Data 1, Data 2, Data 3, Data 4, Data 5, CRC) and a single CRC is calculated at the end. In (b), each PDU contains its own CRC, and the CRC is calculated cumulatively for each segment. + +**Figure 10 – Calculation of CRC** + +### 8.9.2 Receiver invoked operation + +An optional MBFT feature is the ability to request transmission of a specific file (for file retrieval applications) or partial retransmission of a file (to allow recovery in the event of a site being disconnected during a file transfer). Partial file retransmission is particularly useful if a bulk file transfer is interrupted. As the protocol does not require each File-DataPDU to be acknowledged, it is the responsibility of the File ASE issuing the request to indicate how much of the file was successfully received. + +To initiate a file request, a File ASE must first grab the FILE-REQUEST token before issuing a File-Request PDU. This ensures that there is at most one outstanding request on the control channel. If there is no FILE-REQUEST token, then only the channel creator may issue a File-Request. If the token is held by another File ASE, then the File ASE wishing to initiate a file request may ask for the token by issuing an MCS-Token-Please request, specifying the Token ID of the FILE-REQUEST token as Token id. The holder of the token may choose to give the FILE-REQUEST token to the requesting File ASE once it has determined whether its own file request can be satisfied. To do this, the token holder must issue an MCS-Token-Give request, specifying the MCS User ID of the requesting File ASE as User id to receive token and the FILE-REQUEST Token ID as Token id. On receipt of an MCS-Token-Give indication, the requesting File ASE shall issue an MCS-Token-Give response primitive with result parameter 'rt-successful' or 'rt-user-rejected', depending on whether the File ASE still requires the token or not. If the result is 'rt-successful', the File ASE may assume that it has possession of the token. + +The contents of the File-RequestPDU are defined in Table 15. Sufficient information should be included in the request to enable recipients of the PDU to determine whether they are able to supply the file. For partial retransmission of a file, the File ASE must specify the number of octets successfully received prior to the file transfer interruption. A handle is included in the PDU so that responses can be correlated with the request. A FILE-TRANSMIT token must be included in the PDU to ensure that only one File ASE attempts to fulfil the request. + +**Table 15 – File-RequestPDU** + +| Parameter | Description | +|------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| File Header | This parameter uses the T.434 file header structure and should include sufficient information to allow transmitters to determine whether they are able to fulfil the file request. File name and size are suggested as a minimum set. | +| Data Channel ID | This identifies the channel on which the file must be transmitted. It may be either the broadcast data channel, an acknowledged data channel, or the MBFT User ID of the requesting File APE. | +| Request Handle | This is a unique handle used to reference the file request. It need only be locally unique at the requesting File APE. | +| Roster Instance | Application Roster Instance Number as returned in the most recently received GCC-Application-Roster-Report indication. Only File APEs which are enrolled active in the identified roster need to respond to this PDU. File APEs may need to wait to receive this roster report indication before they can generate a reply. | +| FILE-TRANSMIT Token ID | This identifies the token used to ensure that no more than one File APE can attempt to fulfil the file request. Its inclusion is mandatory. | +| FILE-REQUEST Token ID | This identifies the token used to regulate the issuing of file requests, so avoiding the need for other File ASEs to consult the registry. If the token is omitted, only the creator of the control channel is permitted to issue File-Request PDUs. If a FILE-REQUEST token has been assigned to the control channel it must be included. | +| Data Offset | This parameter specifies the starting offset in octets from the beginning of the file data (so zero denotes the origin). | + +The File-RequestPDU includes the identity of the data channel to be used so that the requesting File ASE can specify that: + +- the file is to be sent exclusively to the requester on its File APE MCS User channel; or +- the file is to be broadcast to all File ASEs in the session on the broadcast data channel. In this case, all File ASEs are obliged to receive the data and discard it if it is not required; or +- the file is to be offered to all File ASEs in the session on an acknowledged data channel. In this case, File ASEs may choose whether they wish to receive the data. + +So that the File ASE which issued the File-Request knows how many acknowledgements to accept, all File ASEs included in the Application Roster instance specified in the File-RequestPDU must respond, using the File-DenyPDU (see Table 16) if they are unable to supply the file. File ASEs not included in the specified Application Roster instance must ignore the File-Request. + +**Table 16 – File-DenyPDU** + +| Parameter | Description | +|----------------|---------------------------------------------------------------------------------------------------------------------------------------------------| +| Request Handle | This is a unique handle used to reference the file request. It shall be set to the same value as the handle in the corresponding File-RequestPDU. | +| Reason | This parameter indicates to the requesting File APE why the file could not be provided. | + +A File ASE which is capable of providing the file must first grab the FILE-TRANSMIT token identified in the File-RequestPDU before offering the file for transmission on the data channel shown in the request, using File-Offer as if it had initiated the transaction. If the FILE-TRANSMIT token is not free, the File ASE shall respond with a File-Deny, specifying no Channel as the reason + +for refusal. The requesting File ASE may then make a further attempt, specifying a different data channel. + +If all File ASEs respond with a File-Deny, then the requesting File ASE must relinquish the FILE-REQUEST token, otherwise the token is given up on receipt of the File-OfferPDU corresponding to the required file. Once a File ASE has fulfilled the request by sending a File-Offer, any sites which have not yet responded shall send a File-Deny, even if they are capable of sourcing the file. Further requests may be made by any File ASE on the control channel after the FILE-REQUEST token has been released. + +The requesting File ASE should monitor the application roster to determine which File ASEs to expect responses from. It is recommended that a timeout be used to prevent the application being locked by sites which fail to respond. Any responses received after the timeout expires can be identified by the request handle. + +## 8.10 Remote directory listing + +This is an optional feature which allows a File ASE to obtain a directory listing of a remote site. It may be used in conjunction with the file request mechanism to provide a file retrieval service. A File ASE requiring a directory list issues a Directory-RequestPDU to the MBFT User Channel of the chosen remote site, using the parameters specified in Table 17. + +**Table 17 – Directory-RequestPDU** + +| Parameter | Description | +|-----------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Pathname | This is the relative pathname of the directory for which a listing is required. If omitted or null, it is assumed that a listing of the default directory is requested. | + +A File ASE receiving a Directory-RequestPDU must respond by issuing a Directory-ResponsePDU to the originator's MBFT User Channel, using the parameters defined in Table 18. If the File ASE is able to fulfil the request, it includes a list of files and sub-directories contained in the directory identified in the Directory-RequestPDU. If it is unable or unwilling to provide a list, the File ASE should indicate the reason for refusal in the response. It should be noted that there is no requirement for the directory structure presented to remote sites to be the same as that presented locally. + +**Table 18 – Directory-ResponsePDU** + +| Parameter | Description | +|----------------|---------------------------------------------------------------------------------------------------------------------------| +| Result | This indicates whether the File ASE is able to fulfil the request and, if not, gives the reason for refusal. | +| Pathname | This is the relative pathname of the directory being listed. If omitted or null, the listing is of the default directory. | +| Directory List | This parameter contains a list of files and sub-directories. | + +## 8.11 Conducted mode behaviour + +MBFT is a conductor-aware application protocol, i.e., it has two modes of operation, one for non-conducted mode and one for conducted mode, as described in this subclause. The effect of conducted mode operation on file transactions is determined by the peer File ASE (i.e., a File ASE participating in the same MBFT session) at the node possessing the GCC-Conductor-Token if this ASE is capable of supporting the role of conductor. Each MBFT session has its own conductor, namely the File ASE at the conducting node participating in that session. If there is more than one File ASE at the conducting node participating in a given MBFT session, then it is a local matter for + +GCC at the conducting node to decide which File ASE adopts the role of conductor. When the conducting node does not have a peer File APE which supports the conductor role, the Node Controller at the conducting node proxies as the MBFT conductor. Support of MBFT conducted mode is mandatory. Note that whilst applications must be capable of operating in conducted mode, they do not have to support the MBFT conductor role. + +Applications become aware of a GCC-Conference Conductor being assigned through receipt of a GCC-Conductor-Assign indication from the GCC provider. This includes the GCC User ID of the conducting node. Applications determine the identity of the conducting File ASE from the GCC Application Roster. No new file transactions (File-Offer or File-Request) are allowed after entering conducted mode until permission has been granted by the MBFT conductor. File transactions in progress when conducted mode is entered may continue to completion unless specifically aborted by use of the File-AbortPDU (see clause 8.12). + +File ASEs at the conducting node may initiate transactions without taking any further action. Peer File ASEs at other sites must request permission to act from the MBFT conductor as detailed below. Note that File ASEs not wishing to initiate any file transactions (i.e., those which only wish to receive files offered to them) do not need to request permission from the MBFT conductor. + +### 8.11.1 Peer File APE present at conducting node + +Peer File ASEs at non-conducting nodes must request permission to initiate file transactions by sending an MBFT-Privilege-RequestPDU (Table 19) to the conducting node, specifying the privileges required. The following privileges are available: + +- Privilege to source file transfers. +- Privilege to request file transfers. +- Privilege to create private channels. +- Privilege to use medium priority for file transfers. +- Privilege to issue File-AbortPDUs. +- Privilege to use non-standard extensions. + +**Table 19 – MBFT-Privilege-RequestPDU** + +| Parameter | Description | +|---------------------------|------------------------------------------------------------------------------------------------------------------------------------------| +| File Transfer Privilege | This flag indicates whether the requesting File ASE wants permission to source file transfers. | +| File Request Privilege | This flag indicates whether the requesting File ASE wants permission to request files or retransmissions. | +| Private Channel Privilege | This flag indicates whether the requesting File ASE wants permission to create private channels. | +| Priority Privilege | This flag indicates whether the requesting File ASE wants permission to send medium priority File-DataPDUs. | +| Abort Privilege | This flag indicates whether the requesting File ASE wants permission to issue File-AbortPDUs. | +| Non-Standard Privilege | This flag indicates whether the requesting File ASE wants permission to use any negotiated non-standard extensions to the MBFT protocol. | + +On receipt of an MBFT-Privilege-RequestPDU, the MBFT conductor may respond by broadcasting an MBFT-Privilege-AssignPDU on the control channel. The PDU contains a list of privileges granted and the User ID of the requesting File ASE and enables File ASEs to determine which privileges have been assigned to their peers. The MBFT conductor does not need to send an MBFT-Privilege-AssignPDU if it does not wish to change the privileges of the requesting application. Note + +that the MBFT conductor may at any time revoke some or all of the privileges granted by issuing an MBFT-Privilege-AssignPDU with a revised privilege list for the designated node(s). Any transactions in progress may complete unless specifically aborted. + +If the MBFT conductor receives a GCC-Application-Roster-Report indicating that new nodes have been added to the list of active File ASEs, it shall broadcast an MBFT-Privilege-AssignPDU on the control channel, specifying a list of File ASEs and their associated privileges (see Table 20). Entries in this list need only be made for those nodes which have one or more privileges assigned. + +**Table 20 – MBFT-Privilege-AssignPDU** + +| Parameter | Description | +|---------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Privilege List | This contains a list of one or more MBFT User IDs and the privileges assigned to them. These privileges are identified below. | +| File Transfer Privilege | This flag indicates whether the requesting File ASE has been granted permission to source file transfers. | +| File Request Privilege | This flag indicates whether the requesting File ASE has been granted permission to request files or retransmissions. | +| Private Channel Privilege | This flag indicates whether the requesting File ASE has been granted permission to create private channels. | +| Priority Privilege | This flag indicates whether the requesting File ASE has been granted permission to send medium priority File-DataPDUs. If this flag is set to FALSE, then only low priority can be used for file transfers. | +| Abort Privilege | This flag indicates whether the requesting File ASE has been granted permission to send File-AbortPDUs. | +| Non-Standard Privilege | This flag indicates whether the requesting File ASE has been granted permission to use any negotiated non-standard extensions to the MBFT protocol. | + +If there is a change in conductor without leaving conducted mode, all privileges are automatically revoked and File ASEs must apply to the new MBFT conductor to reacquire them. File ASEs shall consult the Application Roster to determine if there is a new MBFT Conductor for the session. If there is no MBFT conductor present at the new conducting node for that session, File ASEs must cease all transactions immediately. If there is an MBFT conductor present, any transactions in progress at the time of the change may continue unless specifically aborted by the new conductor. + +If a File ASE receives a GCC-Conductor-Permission-Grant indication with the Permission flag set to TRUE it shall have all MBFT privileges granted. If the File ASE subsequently receives a GCC-Conductor-Permission-Grant indication with the Permission flag set to FALSE it shall revert to the privileges assigned to it by the MBFT Conductor. + +If the File ASE receives a GCC-Application-Roster-Report indication in which the MBFT conductor is no longer present, all privileges are revoked and the File ASE shall cease all transactions immediately. + +### **8.11.2 Peer File APE absent at conducting node** + +If there is no peer File APE at the conducting node capable of supporting the conductor role, a File ASE must direct requests to act, via its local Node Controller, to the Node Controller at the conducting node by issuing a GCC-Conductor-Permission-Ask request primitive. If permission is granted, then the File ASE will receive a GCC-Conductor-Permission-Grant indication with the permission flag set to TRUE. This enables the File ASE to act in an unrestricted manner (as in non-conducted mode) until further notice. + +Permission to act may be revoked by the conducting node at any time. If the File ASE receives a GCC-Conductor-Permission-Grant indication with the permission flag set to FALSE, then it must cease all transactions with immediate effect. If the File ASE is transmitting a file it shall issue a final File-DataPDU containing no data and with the abort flag set to TRUE and relinquish the FILE-TRANSMIT token. + +Note that a File ASE may receive an unsolicited successful GCC-Conductor-Permission-Grant indication in response to a GCC-Conductor-Permission-Grant request by its own Node Controller or another application protocol entity at that node or because the conductor decides to grant permission without having received a request. + +## 8.12 Aborting a file transfer + +If an individual File ASE is unable to receive a file or determines that the data is no longer required, it shall either disconnect from the data channel or continue to receive the incoming data and discard it. + +In conducted mode, File ASEs may be granted permission by the MBFT conductor to issue File-AbortPDUs which can be used to order a transmitting File ASE to terminate a file transfer. After receiving a File-Abort PDU, the transmitter is obliged to set the abort flag to TRUE in the current File-DataPDU and then to cease transmission and relinquish the FILE-TRANSMIT token. + +This mechanism can be used by the MBFT conductor to terminate any file transfers in progress on entering conducted mode. + +The transmitter may cease transmission of its own volition by simply setting the abort flag in a File-DataPDU. + +The File-AbortPDU includes a reason code to inform the transmitter why the abort request was generated. The transmission to be terminated can be selected by channel, MBFT User ID or file handle plus MBFT User ID. If no parameters are included, then transmissions on all channels (either static, multicast or private) by any File ASE must cease. If only the MBFT User ID entry is present, then the identified File ASE must cease transmission on all channels. If the MBFT User ID and file handle are present, then the specified file transaction must terminate. See Table 21. + +**Table 21 – File-AbortPDU** + +| Parameter | Description | +|-----------------------------|-------------------------------------------------------------------------------------------------------------------------------------------| +| File Handle | This is a unique handle used to reference the file throughout the file transfer operation. Its value is obtained from the File-Offer PDU. | +| Data Channel ID | This identifies the channel on which file transfers must cease. | +| Transmitter User Channel ID | This identifies the File ASE being requested to cease file transmission. | +| Reason | This is used to inform the transmitter why it must terminate its current operation. | + +## 8.13 Diagnostics + +Support is provided for exchange of diagnostics messages between sending and receiving sites by way of the File-ErrorPDU. The PDU contains three error parameters: an error type (indicating permanent error, transient error or informative message), an error identifier and an optional text message. The action to be taken on receipt of a File-ErrorPDU is not defined by this protocol. See Table 22. + +**Table 22 – File-ErrorPDU** + +| Parameter | Description | +|-------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| File Handle | This is a unique handle used to reference the file throughout the file transfer operation and identifies the file affected. Its value is obtained from the File-OfferPDU. | +| Error type | This field provides an indication of the severity of the fault condition. Faults may be either permanent (causing all transactions to fail), transient (causing failure of the current transmission) or informative (current transaction completed successfully). | +| Error ID | This parameter is a fault code to identify the nature of the problem. | +| Error Text | This optional field allows File ASEs to convey a textual description of the fault condition to the transmitting File ASE. | + +## 8.14 Non-standard operations + +This PDU allows any non-standard information to be transmitted, enabling applications to implement non-standard operations. Use of non-standard operations may be subject to negotiation of associated non-standard capabilities. MBFT-NonStandardPDUs may be sent at any time, but in conducted mode may only be sent by File APEs which have been granted the Non-Standard Privilege. See Table 23. + +**Table 23 – MBFT-NonStandardPDU** + +| Parameter | Description | +|-----------|--------------------------------------------------------------------------------| +| Data | Non-standard parameter. Use of this PDU is not defined in this Recommendation. | + +# 9 MBFT PDU Definitions + +The structure of MBFT PDUs is specified as follows using the notation ASN.1 of [ITU-T X.680]. All MBFT PDUs shall be encoded for transmission by applying the Packed Encoding Rules of [ITU-T X.691] using the Basic Aligned variant. MBFT PDUs are encoded and placed in the data field of either MCS-Send-Data or MCS-Uniform-Send-Data primitives. The bit string generated by the ASN.1 encoding is placed in the OCTET STRING used by MCS in the order such that for each octet, the leading bit is placed in the most significant bit position and the trailing bit is placed in the least significant bit position. + +``` + +MBFT-PROTOCOL {itu-t(0) recommendation(0) t(20) t127(127) version(0) 2 +asn1Modules(2) mBFT-PROTOCOL(1)} DEFINITIONS AUTOMATIC TAGS ::= +BEGIN +IMPORTS + ChannelID, + StaticChannelID, + DynamicChannelID, + UserID, + TokenID, + StaticTokenID, + DynamicTokenID, + Key, + H221NonStandardIdentifier, + NonStandardParameter, + TextString +FROM GCC-PROTOCOL; +-- Export all symbols +-- Part 1: Message Components +Handle ::= INTEGER (0..65535) -- 16-bit value + +``` + +``` + +Contents-Type-Attribute ::= CHOICE +{ + -- See Annex B/ISO 8571-2 for more information + document-type [0] SEQUENCE + { + document-type-name [1] Document-Type-Name, + parameter [0] ISO-8571-2-Parameters OPTIONAL + -- The actual types to be used for values of the parameter + -- field are defined in the document-type-name. + -- Currently, only UNSTRUCTURED TEXT and UNSTRUCTURED BINARY + -- are supported. + } +} + +Document-Type-Name ::= OBJECT IDENTIFIER +ISO-8571-2-Parameters ::= SEQUENCE +{ + universal-class-number [0] INTEGER OPTIONAL, + maximum-string-length [1] INTEGER OPTIONAL, + string-significance [2] INTEGER + {variable (0), fixed (1), not-significant (2)} OPTIONAL +} + +Entity-Reference ::= INTEGER +{ + no-categorisation-possible (0), + initiating-file-service-user (1), + initiating-file-protocol-machine (2), + service-supporting-the-file-protocol-machine (3), + responding-file-protocol-machine (4), + responding-file-service-user (5) +} + +Filename-Attribute ::= SEQUENCE OF GraphicString +Access-Control-Attribute ::= CHOICE +{ + simple-password [0] OCTET STRING, + -- A simplified form of the access control syntax. Specifies + -- one password for all types of access to the files and its + -- attributes + actual-values [1] SET OF Access-Control-Element + -- The semantics of this attribute are described in ISO 8571-2 +} + +Access-Control-Element ::= SEQUENCE +{ + action-list [0] Access-Request, + concurrency-access [1] Concurrency-Access OPTIONAL, + identity [2] User-Identity OPTIONAL, + passwords [3] Access-Passwords OPTIONAL, + ... +} + +Access-Request ::= BIT STRING +{ + read (0), + insert (1), + replace (2), + extend (3), + erase (4), + read-attribute (5), + change-attribute (6), + delete-file (7) +} + +Concurrency-Access ::= SEQUENCE +{ + read [0] Concurrency-Key, + insert [1] Concurrency-Key, + +``` + +``` + + replace [2] Concurrency-Key, + extend [3] Concurrency-Key, + erase [4] Concurrency-Key, + read-attribute [5] Concurrency-Key, + change-attribute [6] Concurrency-Key, + delete-file [7] Concurrency-Key + } +Access-Passwords ::= SEQUENCE +{ + read-password [0] Password, + insert-password [1] Password, + replace-password [2] Password, + extend-password [3] Password, + erase-password [4] Password, + read-attribute-password [5] Password, + change-attribute-password [6] Password, + delete-password [7] Password +} +Password ::= CHOICE +{ + graphic-string GraphicString, + octet-string OCTET STRING +} +Concurrency-Key ::= BIT STRING +{ + not-required (0), + shared (1), + exclusive (2), + no-access (3) +} +Permitted-Actions-Attribute ::= BIT STRING +{ + -- Actions available + read (0), + insert (1), + replace (2), + extend (3), + erase (4) +} +Private-Use-Attribute ::= SEQUENCE +{ + manufacturer-values [0] EXTERNAL OPTIONAL +} +Protocol-Version ::= BIT STRING {version-1 (0)} +User-Identity ::= GraphicString +FileHeader ::= SEQUENCE +{ + protocol-version [28] Protocol-Version DEFAULT {version-1}, -- T.434 version + filename [0] Filename-Attribute OPTIONAL, + permitted-actions [1] Permitted-Actions-Attribute OPTIONAL, + contents-type [2] Contents-Type-Attribute OPTIONAL, + -- DEFAULT {UNSTRUCTURED BINARY} + -- not specifying this attribute implies that the data content of + -- the file is unstructured binary + storage-account [3] GraphicString OPTIONAL, + date-and-time-of-creation [4] GeneralizedTime OPTIONAL, + date-and-time-of-last-modification [5] GeneralizedTime OPTIONAL, + date-and-time-of-last-read-access [6] GeneralizedTime OPTIONAL, + -- 7 is reserved for date-and-time-of-last-attribute-modification + identity-of-creator [8] GraphicString OPTIONAL, + identity-of-last-modifier [9] GraphicString OPTIONAL, + identity-of-last-reader [10] GraphicString OPTIONAL, + -- 11 is reserved for identity-of-last-attribute-modifier + -- 12 is reserved for file-availability + +``` + +``` + + filesize [13] INTEGER OPTIONAL, + future-filesize [14] INTEGER OPTIONAL, + access-control [15] Access-Control-Attribute OPTIONAL, + -- the use of this attribute is for further study + legal-qualifications [16] GraphicString OPTIONAL, + private-use [17] Private-Use-Attribute OPTIONAL, + structure [18] OBJECT IDENTIFIER OPTIONAL, + application-reference [19] SEQUENCE OF GraphicString OPTIONAL, + machine [20] SEQUENCE OF GraphicString OPTIONAL, + operating-system [21] OBJECT IDENTIFIER OPTIONAL, + recipient [22] SEQUENCE OF GraphicString OPTIONAL, + character-set [23] OBJECT IDENTIFIER OPTIONAL, + compression [24] SEQUENCE OF GraphicString OPTIONAL, + -- indicates an optional compression applied to the content + -- octets of the file + environment [25] SEQUENCE OF GraphicString OPTIONAL, + pathname [26] SEQUENCE OF GraphicString OPTIONAL, + user-visible-string [29] SEQUENCE OF GraphicString OPTIONAL, + ... +} +CompressionSpecifier ::= CHOICE +{ + v42bis-parameters V42bis-Parameter-List, + nonstandard-compression-parameters SET OF NonStandardParameter, + ... +} +V42bis-Parameter-List ::= SEQUENCE +{ + p1 INTEGER (512..65535), + p2 INTEGER (6..250), + ... +} +MBFTPrivilege ::= ENUMERATED +{ + file-transmit-privilege (0), -- Privilege to transmit files + file-request-privilege (1), -- Privilege to request files + create-private-privilege (2), -- Privilege to create private channels + medium-priority-privilege (3), -- Privilege to use medium priority for + -- file transfers + abort-privilege (4), -- Privilege to issue File-AbortPDUs + nonstandard-privilege (5), -- Privilege to use non-standard options + -- subject to negotiation + ... +} +DirectoryEntry ::= SEQUENCE +{ + subdirectory-flag BOOLEAN, -- TRUE for sub-directory entries + -- FALSE for file entries + attributes FileHeader, + ... +} +ErrorType ::= ENUMERATED +{ + informative (0), -- No recovery required + transient-error (1), -- Current transfer failed, + -- future transfers may be OK + permanent-error (2), -- Error occurs each time file + -- transfer is performed + ... +} +ErrorID ::= INTEGER + +``` + +``` + +{ + no-reason (0), + responder-error (1), + system-shutdown (2), + bft-management-problem (3), + bft-management-bad-account (4), + bft-management-security-not-passed (5), + delay-may-be-encountered (6), + initiator-error (7), + subsequent-error (8), + temporal-insufficiency-of-resources (9), + access-request-violates-VFS-security (10), + access-request-violates-local-security (11), + conflicting-parameter-values (1000), + unsupported-parameter-values (1001), + mandatory-parameter-not-set (1002), + unsupported-parameter (1003), + duplicated-parameter (1004), + illegal-parameter-type (1005), + unsupported-parameter-types (1006), + bft-protocol-error (1007), + bft-protocol-error-procedure-error (1008), + bft-protocol-error-functional-unit-error (1009), + bft-protocol-error-corruption-error (1010), + lower-layer-failure (1011), + timeout (1013), + invalid-filestore-password (2020), + filename-not-found (3000), + initial-attributes-not-possible (3002), + non-existent-file (3004), + file-already-exists (3005), + file-cannot-be-created (3006), + file-busy (3012), + file-not-available (3013), + filename-truncated (3017), + initial-attributes-altered (3018), + bad-account (3019), + ambiguous-file-specification (3024), + attribute-non-existent (4000), + attribute-not-supported (4003), + bad-attribute-name (4004), + bad-attribute-value (4005), + attribute-partially-supported (4006), + bad-data-element-type (5014), + operation-not-available (5015), + operation-not-supported (5016), + operation-inconsistent (5017), + bad-write (5026), + bad-read (5027), + local-failure (5028), + local-failure-filespace-exhausted (5029), + local-failure-data-corrupted (5030), + local-failure-device-failure (5031), + future-filesize-exceeded (5032), + future-filesize-increased (5034) +} + +-- Part 2: PDU Messages +File-OfferPDU ::= SEQUENCE +{ + file-header FileHeader, + data-channel-id ChannelID, + file-handle Handle, + roster-instance INTEGER (0..65535) OPTIONAL, + +``` + +``` + + file-transmit-token TokenID OPTIONAL, + file-request-token TokenID OPTIONAL, + file-request-handle Handle OPTIONAL, + mbftID UserID OPTIONAL, + compression-specifier CompressionSpecifier OPTIONAL, + compressed-filesize INTEGER OPTIONAL, + ack-flag BOOLEAN, -- True if acknowledgements required + ... + } +File-AcceptPDU ::= SEQUENCE +{ + file-handle Handle, + ... +} + +File-RejectPDU ::= SEQUENCE +{ + file-handle Handle, + reason ENUMERATED + { + unspecified (0), + file-exists (1), + file-not-required(2), + insufficient-resources (3), + transfer-limit (4), -- maximum no. of concurrent + -- file transfers exceeded + compression-unsupported (5), -- algorithm identified + -- in FileOffer not supported + unable-to-join-channel (6), + parameter-not-supported (7), -- at least one File Header + -- parameter is not supported + ... + }, + ... +} + +File-RequestPDU ::= SEQUENCE +{ + file-header FileHeader, + data-channel-id ChannelID, + request-handle Handle, + roster-instance INTEGER (0..65535), + file-transmit-token TokenID, + file-request-token TokenID OPTIONAL, + data-offset INTEGER, + ... +} + +File-DenyPDU ::= SEQUENCE +{ + request-handle Handle, + reason ENUMERATED + { + unspecified (0), + file-not-present (1), + insufficient-privilege (2), + file-already-offered(3), -- File already being offered + -- by another site + ambiguous (4), -- Insufficient attributes to uniquely identify file + no-channel (5), -- No data channel available to fulfil the request + ... + }, + ... +} + +``` + +``` + +File-AbortPDU ::= SEQUENCE +{ + reason ENUMERATED + { + unspecified (0), + bandwidth-required (1), + tokens-required (2), + channels-required (3), + priority-required (4), + ... + }, + data-channel-id ChannelID OPTIONAL, + transmitter-user-id UserID OPTIONAL, + file-handle Handle OPTIONAL, + ... +} + +File-StartPDU ::= SEQUENCE +{ + file-header FileHeader, + file-handle Handle, + eof-flag BOOLEAN, -- True if last packet of data + crc-flag BOOLEAN, -- True if CRC present + compression-specifier CompressionSpecifier OPTIONAL, + comp-file-size INTEGER OPTIONAL, + data-offset INTEGER, + data OCTET STRING (SIZE (0..65535)), + crc-check INTEGER (0..4294967295) OPTIONAL, + ... +} + +File-DataPDU ::= SEQUENCE +{ + file-handle Handle, + eof-flag BOOLEAN, -- True if last packet of data + abort-flag BOOLEAN, -- True if file transfer is being aborted + data OCTET STRING (SIZE (0..65535)), + crc-check INTEGER (0..4294967295) OPTIONAL, + ... +} + +Directory-RequestPDU ::= SEQUENCE +{ + pathname SEQUENCE OF GraphicString OPTIONAL, + ... +} + +Directory-ResponsePDU ::= SEQUENCE +{ + result ENUMERATED + { + unspecified (0), + permission-denied(1), + function-not-supported (2), + successful (3), + ... + }, + pathname SEQUENCE OF GraphicString OPTIONAL, + directory-list SEQUENCE OF DirectoryEntry, + ... +} + +MBFT-Privilege-RequestPDU ::= SEQUENCE +{ + mbft-privilege SET OF MBFTPrivilege, + ... +} + +``` + +``` + +MBFT-Privilege-AssignPDU ::= SEQUENCE +{ + privilege-list SET OF SEQUENCE -- One for each File APE + -- with privileges + { + mbftID UserID, + mbft-privilege SET OF MBFTPrivilege, + ... + }, + ... +} +Private-Channel-Join-InvitePDU ::= SEQUENCE +{ + control-channel-id DynamicChannelID, + data-channel-id DynamicChannelID, + mode BOOLEAN, -- True if broadcast + ... +} +Private-Channel-Join-ResponsePDU ::= SEQUENCE +{ + control-channel-id DynamicChannelID, + result ENUMERATED + { + unspecified (0), + unable-to-join-channel (1), + invitation-rejected (2), + successful (3), + ... + }, + ... +} +File-ErrorPDU ::= SEQUENCE +{ + file-handle Handle OPTIONAL, + error-type ErrorType, + error-id ErrorID, + error-text TextString OPTIONAL, + ... +} +MBFT-NonStandardPDU ::= SEQUENCE +{ + data NonStandardParameter, + ... +} +-- Part 3: Messages sent using MCS-Send-Data or MCS-Uniform-Send-Data +MBFTPDU ::= CHOICE +{ + file-OfferPDUFile-OfferPDU, + file-AcceptPDU File-AcceptPDU, + file-RejectPDU File-RejectPDU, + file-RequestPDU File-RequestPDU, + file-DenyPDU File-DenyPDU, + file-ErrorPDUFile-ErrorPDU, + file-AbortPDUFile-AbortPDU, + file-StartPDUFile-StartPDU, + file-DataPDU File-DataPDU, + directory-RequestPDU Directory-RequestPDU, + directory-ResponsePDU Directory-ResponsePDU, + mbft-Privilege-RequestPDU MBFT-Privilege-RequestPDU, + mbft-Privilege-AssignPDU MBFT-Privilege-AssignPDU, + mbft-NonStandardPDU MBFT-NonStandardPDU, + +``` + +``` + +private-Channel-Join-InvitePDU Private-Channel-Join-InvitePDU, +private-Channel-Join-ResponsePDU Private-Channel-Join-ResponsePDU, +... +} +END + +``` + +# 10 Use of the Multipoint Communication Service + +All MBFT communication shall be through MCS as specified in [ITU-T T.122]. This clause details specific use of MCS services, channel allocation, token allocation and data priorities. Static tokens and channels assigned to MBFT are assigned in [ITU-T T.120]. + +## 10.1 Use of MCS data transmission services + +Either Send-Data or Uniform-Send-Data may be used, at the discretion of the transmitter. Receivers must be capable of accepting both types of data. The channel and priority to be used for each PDU is defined in Table 25. + +## 10.2 Channel allocation + +In each MBFT session, two channels are provided to allow broadcasting of one file at a time. The control channel MBFT-CONTROL is used to manage all aspects of file transfer on the broadcast data channel MBFT-DATA. Each File APE also joins the User-ID channel allocated to it by MCS. Transfer of more than one file simultaneously within the same session requires acknowledged data channels [designated MBFT-DATA(n), where n is the MCS channel ID of the data channel], one per concurrent file transfer. The way in which channel ID values for MBFT-CONTROL and MBFT-DATA are determined depends on a session's mode of operation (static, multicast or private), as explained in clause 8.4.5. The method of determining channel IDs for MBFT-DATA(n) is dependent on whether multicast or private channels are used and is described in clauses 8.6.1 and 8.6.2 respectively. + +A sub-session has a control channel MBFT-CONTROL(p) (where p is the MCS channel ID of the control channel). It may optionally have a single broadcast data channel MBFT-DATA(p) (where p is the MCS channel ID of the data channel) and zero or more acknowledged data channels MBFT-DATA(n). Channel ID values for MBFT-CONTROL(p) and MBFT-DATA(p) are determined by the process described in clause 8.7. See Table 24. + +**Table 24 – MBFT channel description** + +| Mnemonic | Description | +|-----------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| MBFT-CONTROL | Control channel for communication of file exchange management information between all File APEs within a session. File APEs must join and remain joined to this channel for the duration of the session. | +| MBFT-DATA | Broadcast data channel for distribution of file data to all File APEs within a session. File APEs must join and remain joined to this channel for the duration of the session. | +| MBFT-CONTROL(p)
[e.g., MBFT-CONTROL(1001)] | Private control channel whose MCS Channel ID is (p). This channel is used for communication of file exchange management information between all File APEs within a sub-session. File APEs must join and remain joined to this channel for the duration of the sub-session. | +| MBFT-DATA(p)
[e.g., MBFT-DATA(1002)] | Private broadcast data channel whose MCS Channel ID is (p). This channel is used for distribution of file data to all File APEs within a sub-session. The presence of a broadcast data channel within a sub-session is at the discretion of the convenor of the sub-session. If present, File APEs must join and remain joined to this channel for the duration of the sub-session. | + +**Table 24 – MBFT channel description** + +| Mnemonic | Description | +|-----------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| MBFT-DATA(n)
[e.g., MBFT-DATA(1003)] | Acknowledged data channel whose MCS Channel Id is (n). This channel is used for distribution of file data to File APEs within a session or sub-session. File APEs need only join the channel to receive files they require. | +| MBFT User ID channel | For communication from any File APE in a conference to a specific File APE at a particular node. Each File APE is identified by its MCS User ID. | + +**Table 25 – MBFT channel usage** + +| MBFT PDU | Channel | Priority | +|----------------------------------|-----------------------------------------------------------|-----------------| +| File-OfferPDU | MBFT-CONTROL
MBFT-CONTROL(p) | High | +| File-AcceptPDU | MBFT User ID | High | +| File-RejectPDU | MBFT User ID | High | +| File-RequestPDU | MBFT-CONTROL
MBFT-CONTROL(p) | High | +| File-DenyPDU | MBFT User ID | High | +| File-ErrorPDU | MBFT User ID | High | +| File-AbortPDU | MBFT-CONTROL
MBFT-CONTROL(p) | High | +| File-DataPDU | MBFT-DATA
MBFT-DATA(p)
MBFT-DATA(n)
MBFT User ID | Medium, Low | +| File-StartPDU | MBFT-DATA
MBFT-DATA(p)
MBFT-DATA(n)
MBFT User ID | Medium, Low | +| Directory-RequestPDU | MBFT User ID | High | +| Directory-ResponsePDU | MBFT User ID | High | +| MBFT-Privilege-RequestPDU | Conductor MBFT User ID | High | +| MBFT-Privilege-AssignPDU | MBFT-CONTROL | High | +| Private-Channel-Join-InvitePDU | MBFT User ID | High | +| Private-Channel-Join-ResponsePDU | Channel Manager User ID | High | +| MBFT-NonStandardPDU | Not specified | Not specified | + +## 10.3 Token allocation + +MBFT reserves two static tokens for its exclusive use in static mode: FILE-TRANSMIT and FILE-REQUEST. Dynamic equivalents of these tokens may be used for multicast and private modes. + +The session broadcast data channel may have a FILE-TRANSMIT token to ensure that there is only one node transmitting data on the channel at a time. A File ASE intending to transmit a file must grab this token before offering the file to other participants using the File-OfferPDU. Once it has completed the file transmission (i.e., sent a File-StartPDU or File-DataPDU with the off Flag set to + +TRUE), the transmitter should release the FILE-TRANSMIT token to allow other nodes to transmit on the data channel). + +The session control channel may have a FILE-REQUEST token to ensure that there is, at most, one outstanding file request to be processed at any instance. A File ASE requesting a file must grab the FILE-REQUEST token before issuing a File-RequestPDU. It holds the token until it can determine whether another File ASE is able to fulfil the request, i.e., either one File ASE responds with a File-Offer, all File ASEs respond with a File-Deny, or a timeout expires. Once the FILE-REQUEST token is released, other File ASEs may attempt to request files by the same process. + +Each acknowledged data channel may have a FILE-TRANSMIT token associated with it. The FILE-TRANSMIT token associated with an acknowledged data channel whose MCS Channel id is n [MBFT-DATA(n)] is assigned the mnemonic FILE-TRANSMIT(n) [e.g., FILE-TRANSMIT(1006)]. It is functionally identical to the FILE-TRANSMIT token associated with the broadcast data channel. + +A sub-session optionally has a FILE-REQUEST(p) token associated with its MBFT-CONTROL(p) control channel. The FILE-REQUEST(p) token is functionally identical to the FILE-REQUEST token. If the sub-session has a broadcast data channel MBFT-DATA(p), this may optionally have a FILE-TRANSMIT(p) token associated with it. See Table 26. + +**Table 26 – MBFT token description** + +| Mnemonic | Description | +|-------------------------------------------------|--------------------------------------------------------------------------------------------------------------------| +| FILE-REQUEST | Token to ensure that there is at most one outstanding file request on the session control channel MBFT-CONTROL. | +| FILE-TRANSMIT | Token to ensure transmission of one file at a time on the session broadcast data channel MBFT-DATA. | +| FILE-REQUEST(p)
[e.g., FILE-REQUEST(1001)] | Token to ensure that there is at most one outstanding file request on sub-session control channel MBFT-CONTROL(p). | +| FILE-TRANSMIT(p)
[e.g., FILE-TRANSMIT(1002)] | Token to ensure transmission of one file at a time on sub-session broadcast data channel MBFT-DATA(p). | +| FILE-TRANSMIT(n)
[e.g., FILE-TRANSMIT(1003)] | Token to ensure transmission of one file at a time on acknowledged data channel MBFT-DATA(n). | + +## 10.4 MCS services + +MBFT assumes the MCS services indicated in Table 27. All primitives marked with an "M" are mandatory, those marked with an "O" are optional. + +**Table 27 – MCS services used by MBFT** + +| Primitives | Use | +|------------------------------|------------| +| MCS-Attach-User request | M | +| MCS-Attach-User confirm | M | +| MCS-Detach-User request | M | +| MCS-Detach-User indication | M | +| MCS-Channel-Join request | M | +| MCS-Channel-Join confirm | M | +| MCS-Channel-Leave request | M | +| MCS-Channel-Leave indication | M | + +**Table 27 – MCS services used by MBFT** + +| Primitives | Use | +|----------------------------------|------------| +| MCS-Channel-Convene request | O | +| MCS-Channel-Convene confirm | O | +| MCS-Channel-Disband request | O | +| MCS-Channel-Disband indication | M | +| MCS-Channel-Admit request | O | +| MCS-Channel-Admit indication | M | +| MCS-Channel-Expel request | O | +| MCS-Channel-Expel indication | M | +| MCS-Send-Data request | M | +| MCS-Send-Data indication | M | +| MCS-Uniform-Send-Data request | M | +| MCS-Uniform-Send-Data indication | M | +| MCS-Token-Grab request | M | +| MCS-Token-Grab confirm | M | +| MCS-Token-Give request | O | +| MCS-Token-Give indication | M | +| MCS-Token-Give response | M | +| MCS-Token-Give confirm | O | +| MCS-Token-Please request | O | +| MCS-Token-Please indication | M | +| MCS-Token-Release request | O | +| MCS-Token-Release confirm | O | +| MCS-Token-Release indication | M | +| MCS-Token-Test request | O | +| MCS-Token-Test confirm | O | + +# 11 Use of Generic Conference Control + +MBFT assumes the services listed in Table 28. Primitives endorsed with an "M" are mandatory, those marked with an "O" are optional. + +**Table 28 – GCC primitives supported by MBFT** + +| GCC primitive | Use | +|-------------------------------------------------|------------| +| GCC-Application-Permission-To-Enroll indication | M | +| GCC-Application-Enroll request | M | +| GCC-Application-Enroll confirm | M | +| GCC-Application-Roster-Report indication | M | +| GCC-Registry-Retrieve-Entry request | O | +| GCC-Registry-Retrieve-Entry confirm | O | +| GCC-Registry-Register-Channel request | O | +| GCC-Registry-Register-Channel confirm | O | +| GCC-Registry-Assign-Token request | O | +| GCC-Registry-Assign-Token confirm | O | +| GCC-Conductor-Assign indication | M | +| GCC-Conductor-Release indication | M | +| GCC-Conductor-Permission-Ask request | O | +| GCC-Conductor-Permission-Grant request | O | +| GCC-Conductor-Permission-Grant indication | M | + +## 11.1 Resource IDs + +Tables 29 and 30 define the construction of MBFT Resource IDs required for use of the GCC Registry. The registry is not required for the session MBFT-CONTROL channel as the MCS Channel ID can be obtained directly from the Session ID. It is also not required for private sub-session MBFT-CONTROL(p) channels as the MBFT-CONTROL(p) channel ID is conveyed to the selected participants by the private sub-session convenor. The registry may be used to identify the session broadcast data channel using the Resource ID "D0". Acknowledged multicast data channels are not placed in the registry, since the presence of a Registry entry does not guarantee the existence of the channel (see clause 8.6.2). Private data channels are not placed in the Registry since File ASEs are not permitted to join such channels until they receive an MCS-Channel-Admit from the channel convenor. + +FILE-TRANSMIT(n) and FILE-TRANSMIT(p) Token IDs are constructed by expressing the MCS Channel ID of the associated MBFT-DATA(n) or MBFT-DATA(p) channel as a decimal numeric string without leading zeroes, prepending the single character "T", and encoding these characters into successive octets according to ITU-T Rec. T.50. FILE-REQUEST(p) Token IDs are constructed by expressing the MCS Channel ID of the associated MBFT-CONTROL(p) channel as a decimal numeric string without leading zeroes, prepending the single character "R", and encoding these characters into successive octets according to ITU-T Rec. T.50. + +**Table 29 – Channel determination** + +| Mnemonic | Channel ID of static channels | Application registry resource ID for dynamic channels | +|-----------------|--------------------------------------|--------------------------------------------------------------| +| MBFT-CONTROL | MBFT-CHANNEL-0 | – | +| MBFT-DATA | MBFT-CHANNEL-1 | D0 | +| MBFT-CONTROL(p) | – | – | +| MBFT-DATA(p) | – | – | +| MBFT-DATA(n) | – | – | + +**Table 30 – Token determination** + +| Mnemonic | Token ID of Static Tokens | Application registry
resource ID
for dynamic tokens | +|------------------|----------------------------------|--------------------------------------------------------------------| +| FILE-REQUEST | MBFT-TOKEN-0 | R0 | +| FILE-TRANSMIT | MBFT-TOKEN-1 | T0 | +| FILE-REQUEST(p) | – | Rp (e.g., R1001) | +| FILE-TRANSMIT(p) | – | Tp (e.g., T1002) | +| FILE-TRANSMIT(n) | – | Tn (e.g., T1003) | + +# **Annex A** + +## **Static channel and token assignment** + +(This annex forms an integral part of this Recommendation) + +The assignment of static resources (channels and tokens) is to be defined in [ITU-T T.120], but is included in this Recommendation pending the completion of [ITU-T T.120]. See Tables A.1 and A.2. + +**Table A.1 – Static channel ID assignments** + +| Symbolic name | MCS Channel ID | +|----------------------|-----------------------| +| MBFT-CHANNEL-0 | 9 | +| MBFT-CHANNEL-1 | 10 | + +**Table A.2 – Static token ID assignments** + +| Symbolic Name | MCS Token ID | +|----------------------|---------------------| +| MBFT-TOKEN-0 | 10 | +| MBFT-TOKEN-1 | 11 | + +# **Annex B** + +## **Object Identifier assignments** + +(This annex forms an integral part of this Recommendation) + +Table B.1 lists the assignment of Object Identifiers defined for use by this Recommendation. + +**Table B.1 – T.127 object identifier assignment** + +| Object Identifier Value | Description | +|-------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------| +| {itu-t recommendation t 127 version(0) 2} | This Object Identifier is used to indicate the version of this Recommendation. At this time there is a single standardized version defined. | + +# Appendix I + +## File Transfer Examples + +(This appendix does not form an integral part of this Recommendation) + +**I.1** A number of examples of file transactions are given below to illustrate use of this Recommendation in different scenarios. + +The following conventions are adopted in the figures: + +Each PDU is followed by a Channel name enclosed in parentheses thus (). This indicates the channel on which the PDU is to be sent. Where appropriate, significant PDU parameters are appended in parentheses after the Channel ID. + +Primitives are optionally followed by key parameters enclosed in square brackets thus [ ]. + +Note that the figures only denote transactions between a File APE, its peers and its local MCS and GCC providers. Transactions between the local MCS and GCC providers and the top MCS and GCC providers are omitted for clarity. + +**I.1.1** Figure I.1 illustrates distribution of a file on the broadcast data channel. All File APEs participating in the session are obliged to receive the data and discard it locally if it is not required. + +**I.1.2** Figure I.2 illustrates the creation and use of an acknowledged multicast data channel when at least one node wishes to receive the file being offered. + +**I.1.3** Figure I.3 illustrates an attempt to distribute a file on an acknowledged channel which is aborted because all receivers reject the file. It is assumed that the data channel and the associated FILE-TRANSMIT(n) token already exist. + +**I.1.4** Figure I.4 illustrates file distribution to a subset of the participants in the current session using a private sub-session. Participants have the option of rejecting files offered to them, and any site may attempt to request or offer files when the current transaction has finished. + +**I.1.5** Figure I.5 illustrates file distribution to a subset of the participants in the current session using a private sub-session. Participants have the option of rejecting files offered to them, but only the creator is permitted to transmit files. Note that the creator does not need to join the MBFT-DATA(n) channel, since it will never receive files. + +![Sequence diagram showing the process of broadcasting files between Local and Remote entities. The diagram includes lifelines for Local file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Remote file APE(s). Operations include token grabbing, file offering, data transmission, and token releasing.](c0b9e5fc63e19306394e0d4249da62cd_img.jpg) + +``` + +sequenceDiagram + participant Lfile as Local file APE + participant LGCC as Local GCC provider + participant LMCS as Local MCS provider + participant RMCS as Remote MCS provider(s) + participant RGCC as Remote GCC provider(s) + participant Rfile as Remote file APE(s) + + Lfile->>LMCS: MCS-TOKEN-GRAB req. [FILE-TRANSMIT] + LMCS->>Lfile: MCS-TOKEN-GRAB con. [FILE-TRANSMIT] + LMCS->>Rfile: File-OfferPDU (MBFT-CONTROL Channel) (Ack = FALSE) + LMCS->>Rfile: File-StartPDU (MBFT-DATA Channel) (Eof = FALSE) + LMCS->>Rfile: File-DataPDU (MBFT-DATA Channel) (Eof = FALSE) + LMCS->>Rfile: File-DataPDU (MBFT-DATA Channel) (Eof = FALSE) + LMCS->>Rfile: File-DataPDU (MBFT-DATA Channel) (Eof = TRUE) + Lfile->>LMCS: MCS-TOKEN-REL req. [FILE-TRANSMIT] + LMCS->>Lfile: MCS-TOKEN-REL con. [FILE-TRANSMIT] + +``` + +The diagram illustrates the sequence of operations for broadcasting files. It involves six lifelines: Local file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Remote file APE(s). The operations are as follows: + +- Token Grabbing:** The Local file APE sends an `MCS-TOKEN-GRAB req. [FILE-TRANSMIT]` to the Local MCS provider, which responds with `MCS-TOKEN-GRAB con. [FILE-TRANSMIT]`. +- File Offering:** The Local MCS provider sends a `File-OfferPDU (MBFT-CONTROL Channel) (Ack = FALSE)` to the Remote file APE(s). +- Data Transmission:** The Local MCS provider sends a `File-StartPDU (MBFT-DATA Channel) (Eof = FALSE)` followed by three `File-DataPDU (MBFT-DATA Channel)` messages (two with `Eof = FALSE` and one with `Eof = TRUE`) to the Remote file APE(s). +- Token Releasing:** The Local file APE sends an `MCS-TOKEN-REL req. [FILE-TRANSMIT]` to the Local MCS provider, which responds with `MCS-TOKEN-REL con. [FILE-TRANSMIT]`. + +Horizontal bars on the Remote file APE(s) lifeline indicate periods of activity during the token grabbing and data transmission phases. + +Sequence diagram showing the process of broadcasting files between Local and Remote entities. The diagram includes lifelines for Local file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Remote file APE(s). Operations include token grabbing, file offering, data transmission, and token releasing. + +T.127(07)\_F-I.1 + +**Figure I.1 – Broadcasting of files** + +![Sequence diagram showing a successful acknowledged file transfer between Local file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Remote file APE(s). The process includes channel joining, token assignment, file offering, acceptance, data transfer, and token release.](51d4540605fdfa2c090638305022143b_img.jpg) + +``` + +sequenceDiagram + participant Lfile as Local file APE + participant LGCC as Local GCC provider + participant LMCS as Local MCS provider + participant RMCS as Remote MCS provider(s) + participant RGCC as Remote GCC provider(s) + participant Rfile as Remote file APE(s) + + Lfile->>LMCS: MCS-CHANNEL-JOIN req. [Channel ID = 0] + LMCS->>Lfile: MCS-CHANNEL-JOIN con. [MBFT-DATA(n) Channel ID = unique new] + Lfile->>LGCC: GCC-Registry-Assign-Token req. + LGCC->>Lfile: GCC-Registry-Assign-Token con. [FILE-TRANSMIT(n)=unique new] + Lfile->>LMCS: MCS-TOKEN-GRAB req. [FILE-TRANSMIT(n)] + LMCS->>Lfile: MCS-TOKEN-GRAB con. [FILE-TRANSMIT(n)] + LMCS->>Rfile: File-OfferPDU (MBFT-CONTROL Channel) (Ack = TRUE) + Rfile->>RMCS: MCS-CHANNEL-JOIN req. [MBFT-DATA(n)] + RMCS->>Rfile: MCS-CHANNEL-JOIN con. [MBFT-DATA(n)] + Rfile->>Lfile: File-AcceptPDU (Transmitter MBFT User ID Channel) + LMCS->>Rfile: File-StartPDU (MBFT-DATA(n) Channel) (Eof = FALSE) + LMCS->>Rfile: File-DataPDU (MBFT-DATA(n) Channel) (Eof = FALSE) + LMCS->>Rfile: File-DataPDU (MBFT-DATA(n) Channel) (Eof = FALSE) + LMCS->>Rfile: File-DataPDU (MBFT-DATA(n) Channel) (Eof = TRUE) + Lfile->>LMCS: MCS-TOKEN-REL req. [FILE-TRANSMIT(n)] + LMCS->>Lfile: MCS-TOKEN-REL con. [FILE-TRANSMIT(n)] + +``` + +Local file APE + +Local GCC provider + +Local MCS provider + +Remote MCS provider(s) + +Remote GCC provider(s) + +Remote file APE(s) + +Operation + +MCS-CHANNEL-JOIN req. [Channel ID = 0] + +MCS-CHANNEL-JOIN con. [MBFT-DATA(n) Channel ID = unique new] + +GCC-Registry-Assign-Token req. + +GCC-Registry-Assign-Token con. [FILE-TRANSMIT(n)=unique new] + +MCS-TOKEN-GRAB req. [FILE-TRANSMIT(n)] + +MCS-TOKEN-GRAB con. [FILE-TRANSMIT(n)] + +File-OfferPDU (MBFT-CONTROL Channel) (Ack = TRUE) + +MCS-CHANNEL-JOIN req. [MBFT-DATA(n)] + +MCS-CHANNEL-JOIN con. [MBFT-DATA(n)] + +File-AcceptPDU (Transmitter MBFT User ID Channel) + +File-StartPDU (MBFT-DATA(n) Channel) (Eof = FALSE) + +File-DataPDU (MBFT-DATA(n) Channel) (Eof = FALSE) + +File-DataPDU (MBFT-DATA(n) Channel) (Eof = FALSE) + +File-DataPDU (MBFT-DATA(n) Channel) (Eof = TRUE) + +MCS-TOKEN-REL req. [FILE-TRANSMIT(n)] + +MCS-TOKEN-REL con. [FILE-TRANSMIT(n)] + +Transmitter joins new multicast channel (if none exists) + +Transmitter assigns FILE-TRANSMIT(n) token for new multicast channel + +Transmitter grabs FILE-TRANSMIT(n) token + +Transmitter offers file + +Receivers join MBFT-DATA(n) channel and accept the offer + +Transmitter sends file on multicast channel MBFT-DATA(n) + +Transmitter releases FILE-TRANSMIT(n) token + +T.127(07)\_F-I.2 + +Sequence diagram showing a successful acknowledged file transfer between Local file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Remote file APE(s). The process includes channel joining, token assignment, file offering, acceptance, data transfer, and token release. + +**Figure I.2 – Successful acknowledged file transfer** + +![Sequence diagram showing a rejected acknowledged file transfer between Local file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Remote file APE(s). The process includes token grabbing, file offering, channel leaving, rejection, and token releasing.](c2c4e63ebb9afc1ab64e39a159890e0f_img.jpg) + +``` + +sequenceDiagram + participant LFA as Local file APE + participant LGCP as Local GCC provider + participant LMCS as Local MCS provider + participant RMCS as Remote MCS provider(s) + participant RGCP as Remote GCC provider(s) + participant RFA as Remote file APE(s) + + Note over LFA, RFA: Transmitter grabs FILE-TRANSMIT(n) token + LFA->>LMCS: MCS-TOKEN-GRAB req. [FILE-TRANSMIT(n)] + LMCS-->>LFA: MCS-TOKEN-GRAB con. [FILE-TRANSMIT(n)] + + Note over LFA, RFA: Transmitter offers file + LMCS->>RFA: File-OfferPDU (MBFT-CONTROL Channel) (Ack = TRUE) + + Note over LFA, RFA: Receivers leave MBFT-DATA(n) channel (if joined to it) + RFA->>RMCS: MCS-CHANNEL-LEAVE req. [MBFT-DATA(n) Channel ID] + RMCS-->>RFA: MCS-CHANNEL-LEAVE con. [MBFT-DATA(n) Channel ID] + + Note over LFA, RFA: Receivers reject file offer + RFA->>LFA: File-RejectPDU (Transmitter MBFT User ID Channel) + + Note over LFA, RFA: Transmitter releases FILE-TRANSMIT(n) token + LFA->>LMCS: MCS-TOKEN-REL req. [FILE-TRANSMIT(n)] + LMCS-->>LFA: MCS-TOKEN-REL con. [FILE-TRANSMIT(n)] + +``` + +T.127(07)\_F-I.3 + +Sequence diagram showing a rejected acknowledged file transfer between Local file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Remote file APE(s). The process includes token grabbing, file offering, channel leaving, rejection, and token releasing. + +**Figure I.3 – Rejected acknowledged file transfer** + +![Sequence diagram for Private sub-session file transfer using acknowledged data channel. The diagram shows interactions between Local file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Remote file APE(s). The process includes channel convening, token assignment, file offer/acceptance, data transfer, and channel disbanding.](6f11044c88ea04e43de06c3491defeee_img.jpg) + +The diagram illustrates the sequence of operations for a private sub-session file transfer using an acknowledged data channel. The participants involved are a Local file APE, a Local GCC provider, a Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and a Remote file APE(s). + +**Operations and Messages:** + +- Channel Convening:** + - Local file APE sends **MCS-CHANNEL-CONVENE req.** to Local MCS provider. + - Local MCS provider sends **MCS-CHANNEL-CONVENE con. [MBFT-CONTROL(p) Channel ID n = unique new]** to Local file APE. + - Local file APE sends **MCS-CHANNEL-JOIN req. [MBFT-CONTROL(p)]** to Local MCS provider. + - Local MCS provider sends **MCS-CHANNEL-JOIN con.** to Local file APE. + - Local file APE sends **MCS-CHANNEL-CONVENE req.** to Remote MCS provider(s). + - Remote MCS provider(s) sends **MCS-CHANNEL-CONVENE con. [MBFT-DATA(n) Channel ID = unique new]** to Local file APE. + - Local file APE sends **MCS-CHANNEL-JOIN req. [MBFT-DATA(n)]** to Remote MCS provider(s). + - Remote MCS provider(s) sends **MCS-CHANNEL-JOIN con.** to Local file APE. +- Channel Invitation:** + - Local file APE sends **Private-Channel-InvitePDU [Mode = FALSE] (MBFT User ID Channels of File APEs to be invited)** to Remote file APE(s). +- Channel Admission:** + - Local file APE sends **MCS-CHANNEL-ADMIT req. [MBFT-CONTROL(p), MBFT User ID(s)]** to Remote MCS provider(s). + - Remote MCS provider(s) sends **MCS-CHANNEL-ADMIT ind. [Channel ID]** to Remote GCC provider(s). + - Remote GCC provider(s) sends **MCS-CHANNEL-JOIN req. [MBFT-CONTROL(p)]** to Remote file APE(s). + - Remote file APE(s) sends **MCS-CHANNEL-JOIN con.** to Remote GCC provider(s). + - Local file APE sends **MCS-CHANNEL-ADMIT req. [MBFT-DATA(n), MBFT User ID(s)]** to Remote MCS provider(s). + - Remote MCS provider(s) sends **MCS-CHANNEL-ADMIT ind. [Channel ID]** to Remote GCC provider(s). + - Remote GCC provider(s) sends **MCS-CHANNEL-JOIN req. [MBFT-DATA(n)]** to Remote file APE(s). + - Remote file APE(s) sends **MCS-CHANNEL-JOIN con.** to Remote GCC provider(s). +- Channel Acknowledgment:** + - Local file APE sends **Private-Channel-Join-AckPDU (Convenor MBFT User ID Channel)** to Remote file APE(s). +- Token Assignment:** + - Local file APE sends **GCC-Registry-Assign-Token req.** to Local GCC provider. + - Local GCC provider sends **GCC-Registry-Assign-Token con. [FILE-TRANSMIT(n)=unique new]** to Local file APE. + - Local file APE sends **GCC-Registry-Assign-Token req.** to Remote GCC provider(s). + - Remote GCC provider(s) sends **GCC-Registry-Assign-Token con. [FILE-REQUEST(p)=unique new]** to Local file APE. + - Local file APE sends **MCS-TOKEN-GRAB req. [FILE-TRANSMIT(n)]** to Local MCS provider. + - Local MCS provider sends **MCS-TOKEN-GRAB con. [FILE-TRANSMIT(n)]** to Local file APE. +- File Transfer:** + - Local file APE sends **File-OfferPDU (MBFT-CONTROL(p) Channel) (Ack = TRUE)** to Remote file APE(s). + - Remote file APE(s) sends **File-AcceptPDU (Transmitter MBFT User Channel)** to Local file APE. + - Local file APE sends **File-StartPDU (MBFT-DATA(n) Channel) (Eof = FALSE)** to Remote file APE(s). + - Local file APE sends **File-DataPDU (MBFT-DATA(n) Channel) (Eof = FALSE)** to Remote file APE(s). + - Local file APE sends **File-DataPDU (MBFT-DATA(n) Channel) (Eof = FALSE)** to Remote file APE(s). + - Local file APE sends **File-DataPDU (MBFT-DATA(n) Channel) (Eof = TRUE)** to Remote file APE(s). +- Token Release:** + - Local file APE sends **MCS-TOKEN-REL req. [FILE-TRANSMIT(n)]** to Local MCS provider. + - Local MCS provider sends **MCS-TOKEN-REL con. [FILE-TRANSMIT(n)]** to Local file APE. +- Channel Disbanding:** + - Local file APE sends **MCS-CHANNEL-DISBAND req. [Channel ID = MBFT-DATA(n)]** to Local MCS provider. + - Local MCS provider sends **MCS-CHANNEL-EXPEL ind. [Channel ID = MBFT-DATA(n)]** to Remote MCS provider(s). + - Remote MCS provider(s) sends **MCS-CHANNEL-EXPEL ind. [Channel ID]** to Remote GCC provider(s). + - Local file APE sends **MCS-CHANNEL-DISBAND req. [Channel ID = MBFT-CONTROL(p)]** to Local MCS provider. + - Local MCS provider sends **MCS-CHANNEL-EXPEL ind. [Channel ID = MBFT-CONTROL(p)]** to Remote MCS provider(s). + - Remote MCS provider(s) sends **MCS-CHANNEL-EXPEL ind. [Channel ID]** to Remote GCC provider(s). +- Registry Cleanup:** + - Local file APE sends **GCC-Registry-Delete-Entry req. [FILE-TRANSMIT(n) token]** to Local GCC provider. + - Local GCC provider sends **GCC-Registry-Delete-Entry con. [FILE-TRANSMIT(n) token]** to Local file APE. + - Local file APE sends **GCC-Registry-Delete-Entry req. [FILE-REQUEST(p) token]** to Local GCC provider. + - Local GCC provider sends **GCC-Registry-Delete-Entry con. [FILE-REQUEST(p) token]** to Local file APE. + +The diagram also includes a lightning bolt symbol indicating a break in the sequence of operations. + +Sequence diagram for Private sub-session file transfer using acknowledged data channel. The diagram shows interactions between Local file APE, Local GCC provider, Local MCS provider, Remote MCS provider(s), Remote GCC provider(s), and Remote file APE(s). The process includes channel convening, token assignment, file offer/acceptance, data transfer, and channel disbanding. + +T.127(07)\_F-L4 + +**Figure I.4 – Private sub-session file transfer using acknowledged data channel** + +![Sequence diagram for Private sub-session file transfer on acknowledged data channel (convenor use only).](7e14467740b2570a44379b347a697921_img.jpg) + +``` + +sequenceDiagram + participant LAPE as Local file APE + participant LGCC as Local GCC provider + participant LMCS as Local MCS provider + participant RMCS as Remote MCS provider(s) + participant RGCC as Remote GCC provider(s) + participant RAPE as Remote file APE(s) + + Note over LAPE, RAPE: Transmitter convenes and joins a private MBFT-CONTROL(p) channel + LAPE->>LGCC: MCS-CHANNEL-CONVENE req. + LGCC->>LAPE: MCS-CHANNEL-CONVENE con. [MBFT-CONTROL(p) Channel ID = unique new] + LAPE->>LGCC: MCS-CHANNEL-JOIN req. [MBFT-CONTROL(p)] + LGCC->>LAPE: MCS-CHANNEL-JOIN con. + + Note over LAPE, RAPE: Transmitter convenes a private MBFT-DATA(n) channel + LAPE->>LGCC: MCS-CHANNEL-CONVENE req. + LGCC->>LAPE: MCS-CHANNEL-CONVENE con. [MBFT-DATA(n) Channel ID = unique new] + LAPE->>RAPE: Private-Channel-InvitePDU [Mode = FALSE] (MBFT User ID Channels of File APEs to be invited) + + Note over LAPE, RAPE: Transmitter invites each receiver individually to join both channels + LAPE->>LGCC: MCS-CHANNEL-ADMIT req. [MBFT-CONTROL(p), MBFT User ID(s)] + LGCC->>RMCS: MCS-CHANNEL-ADMIT ind. [Channel ID] + RMCS->>RGCC: MCS-CHANNEL-JOIN req. [MBFT-CONTROL(p)] + RGCC->>RMCS: MCS-CHANNEL-JOIN con. + + Note over LAPE, RAPE: Transmitter admits other file APEs to the private MBFT-CONTROL(p) channel + LAPE->>LGCC: MCS-CHANNEL-ADMIT req. [MBFT-DATA(n), MBFT User ID(s)] + LGCC->>RMCS: MCS-CHANNEL-ADMIT ind. [Channel ID] + RMCS->>RGCC: MCS-CHANNEL-JOIN req. [MBFT-DATA(n)] + RGCC->>RMCS: MCS-CHANNEL-JOIN con. + + Note over LAPE, RAPE: Receivers join private MBFT-CONTROL(p) channel + RMCS->>LAPE: Private-Channel-Join-AckPDU (Convenor MBFT User ID Channel) + + Note over LAPE, RAPE: Receivers join private MBFT-DATA(n) channel + RMCS->>LAPE: File-OfferPDU (MBFT-CONTROL(p) Channel) (Ack = TRUE) + + Note over LAPE, RAPE: Receivers notify convenor that they have joined control channel + LAPE->>RMCS: File-AcceptPDU (Transmitter MBFT User ID Channel) + + Note over LAPE, RAPE: Transmitter offers file + LAPE->>RAPE: File-StartPDU (MBFT-DATA(n) Channel) (Eof = FALSE) + + Note over LAPE, RAPE: Receivers accept offer + LAPE->>RAPE: File-DataPDU (MBFT-DATA(n) Channel) (Eof = FALSE) + LAPE->>RAPE: File-DataPDU (MBFT-DATA(n) Channel) (Eof = FALSE) + + Note over LAPE, RAPE: Transmitter sends file on MBFT-DATA(n) channel + LAPE->>RAPE: File-DataPDU (MBFT-DATA(n) Channel) (Eof = TRUE) + + Note over LAPE, RAPE: Further file transactions + + Note over LAPE, RAPE: Convenor disbands both private channels + LAPE->>LGCC: MCS-CHANNEL-DISBAND req. [Channel ID = MBFT-DATA(n)] + LGCC->>RMCS: MCS-CHANNEL-EXPEL ind. [Channel ID = MBFT-DATA(n)] + RMCS->>RGCC: MCS-CHANNEL-EXPEL ind. [Channel ID] + LAPE->>LGCC: MCS-CHANNEL-DISBAND req. [Channel ID = MBFT-CONTROL(p)] + LGCC->>RMCS: MCS-CHANNEL-EXPEL ind. [Channel ID = MBFT-CONTROL(p)] + RMCS->>RGCC: MCS-CHANNEL-EXPEL ind. [Channel ID] + +``` + +Sequence diagram for Private sub-session file transfer on acknowledged data channel (convenor use only). + +T.127(07)\_F-I.5 + +**Figure I.5 – Private sub-session file transfer on acknowledged data channel +(convenor use only)** + +# Appendix II + +## MBFT attributes + +(This appendix does not form an integral part of this Recommendation) + +A large number of parameters may be used to describe a file and its properties, as identified in Table II.1. The File-OfferPDU should include sufficient information to allow a site to determine whether a file is required and if it is capable of being received; filename and filesize are thus suggested as a minimum set, but no parameters are mandated. If insufficient (or no) information is provided and sites subsequently discover that they do not wish or are unable to continue receiving a file, they must disconnect from the data channel or discard the incoming data. + +File-Start and File-DataPDUs are used to transport the entire file structure, including header information. Note that this may duplicate or supplement information contained in the File-OfferPDU. + +File attributes are derived from [ITU-T T.434]. + +**Table II.1 – MBFT file attributes** + +| Attribute | Comments | +|------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------| +| Filename | A sequence of name components, the first element being the filename, and any subsequent components being concatenated to represent the file prefix. | +| Date and time of last modification | Expressed as GeneralizedTime | +| Compression | Applies only to file data | +| Filesize | Size in octets of the complete file | +| Protocol version | T.434 protocol version number | +| Permitted actions | Read, insert, replace, extend, erase | +| Contents type | Unstructured text, unstructured binary | +| Storage account | Identifies the accountable authority responsible for file storage charges | +| Date and time of creation | Expressed as GeneralizedTime | +| Date and time of last read access | Expressed as GeneralizedTime | +| Identity of creator | | +| Identity of last modifier | | +| Identifier of last reader | | +| Future filesize | Maximum file size in octets | +| Access control | For further study | +| Legal qualifications | Reflects the legal status of the file | +| Private use | Allows definition of proprietary attributes | +| Structure | Indicates the format of the data being transferred | + +**Table II.1 – MBFT file attributes** + +| Attribute | Comments | +|-----------------------|-------------------------------------------------------------------------------------------------------------------| +| Application reference | Additional information describing various aspects of the environment the binary file transfer is originating from | +| Machine | | +| Operating system | | +| Environment | | +| Pathname | | +| User visible string | | +| Recipient | The final user destination of the binary file transfer | +| Character set | Identifies which international character set is to be used | + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|---------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.128-200806-I_PDF-E/raw.md b/marked/T/T-REC-T.128-200806-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..963d6397a435587a03d7b3cf15586941d979252a --- /dev/null +++ b/marked/T/T-REC-T.128-200806-I_PDF-E/raw.md @@ -0,0 +1,7568 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**T.128** + +(06/2008) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES +Data protocols for multimedia conferencing + +# --- **Multipoint application sharing** + +Recommendation ITU-T T.128 + +## ITU-T T-SERIES RECOMMENDATIONS TERMINALS FOR TELEMATIC SERVICES + +| | | +|-----------------------------------------------------|--------------------| +| Facsimile – Framework | T.0–T.19 | +| Still-image compression – Test charts | T.20–T.29 | +| Facsimile – Group 3 protocols | T.30–T.39 | +| Colour representation | T.40–T.49 | +| Character coding | T.50–T.59 | +| Facsimile – Group 4 protocols | T.60–T.69 | +| Telematic services – Framework | T.70–T.79 | +| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89 | +| Telematic services – ISDN Terminals and protocols | T.90–T.99 | +| Videotext – Framework | T.100–T.109 | +| Data protocols for multimedia conferencing | T.120–T.149 | +| Telewriting | T.150–T.159 | +| Multimedia and hypermedia framework | T.170–T.189 | +| Cooperative document handling | T.190–T.199 | +| Telematic services – Interworking | T.300–T.399 | +| Open document architecture | T.400–T.429 | +| Document transfer and manipulation | T.430–T.449 | +| Document application profile | T.500–T.509 | +| Communication application profile | T.510–T.559 | +| Telematic services – Equipment characteristics | T.560–T.649 | +| Still-image compression – JPEG 2000 | T.800–T.849 | +| Still-image compression – JPEG-1 extensions | T.850–T.899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **Recommendation ITU-T T.128** + +# **Multipoint application sharing** + +## **Summary** + +Recommendation ITU-T T.128 defines a protocol that supports multipoint application sharing. + +The T.128 protocol supports multipoint computer application sharing by allowing a view onto a computer application executing at one site to be advertised within a session to other sites. Each site can, under specified conditions, take control of the shared computer application by sending remote keyboard and pointing device information. This style of application sharing does not require and does not make provision for synchronizing multiple instances of the same computer application running at multiple sites. Instead, it enables remote viewing and control of a single application instance to provide the illusion that the application is running locally. + +This Recommendation uses services provided by Recommendations ITU-T T.122 (MCS) and T.124 (GCC). + +This revised version of Recommendation ITU-T T.128 introduces a number of modifications to legacy mode ASN.1 definition of the application sharing protocol. + +## **Source** + +Recommendation ITU-T T.128 was approved on 13 June 2008 by ITU-T Study Group 16 (2005-2008) under Recommendation ITU-T A.8 procedure. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2009 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +# CONTENTS + +| | Page | +|----------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References..... | 2 | +| 3 Definitions ..... | 3 | +| 4 Abbreviations and acronyms ..... | 4 | +| 5 Overview ..... | 4 | +| 5.1 Legacy and base modes ..... | 4 | +| 5.2 AS concepts ..... | 5 | +| 6 Use of MCS ..... | 10 | +| 6.1 MCS channel usage ..... | 11 | +| 6.2 Use of MCS data services..... | 11 | +| 7 Use of GCC ..... | 13 | +| 8 Protocol specification ..... | 14 | +| 8.1 AS sessions..... | 14 | +| 8.2 Capabilities..... | 14 | +| 8.3 ASPDU formats..... | 36 | +| 8.4 ASCE activation ..... | 40 | +| 8.5 Flow control..... | 47 | +| 8.6 Synchronization..... | 52 | +| 8.7 Remote sharing..... | 56 | +| 8.8 Fonts ..... | 57 | +| 8.9 Application management..... | 69 | +| 8.10 Window list management..... | 70 | +| 8.11 Window activation..... | 76 | +| 8.12 Control..... | 80 | +| 8.13 Mediated control..... | 83 | +| 8.14 Pointers ..... | 87 | +| 8.15 Palette updates ..... | 91 | +| 8.16 Order updates..... | 92 | +| 8.17 Bitmap updates ..... | 133 | +| 8.18 Input..... | 139 | +| 8.19 Conducted mode operation..... | 147 | +| 9 ASPDU definitions ..... | 148 | +| 9.1 Legacy mode ASN.1 definition ..... | 148 | +| 9.2 Base mode ASN.1 definition ..... | 168 | +| 9.3 Legacy mode encoding rules ..... | 190 | +| 9.4 Base mode non-collapsing capabilities encoding rules ..... | 190 | +| Annex A – Static channel ID assignments..... | 192 | + +| | Page | +|------------------------------------------------|-------------| +| Annex B – Legacy application protocol key..... | 193 | +| Annex C – Object identifier assignments ..... | 194 | +| Appendix I – Informative values ..... | 195 | +| I.1    Flow control..... | 195 | +| I.2    Bitmap caching..... | 196 | +| I.3    ColorTable caching ..... | 196 | +| I.4    Pointer caching ..... | 196 | +| I.5    Desktop save cache..... | 196 | +| I.6    General compression ..... | 196 | + +**Recommendation ITU-T T.128** + +### **Multipoint application sharing** + +**1 Scope** + +This Recommendation defines a protocol that supports multipoint application sharing. It uses services provided by [ITU-T T.122] (MCS) and [ITU-T T.124] (GCC). + +The details of communication with the input and output devices and the user interfaces on the host terminal are considered out of the scope of this Recommendation and are left to the discretion of the implementer. Therefore, this Recommendation makes no assumption that these input and output devices and user interfaces are of any specific architecture. + +Figure 1 presents an overview of the scope of this Recommendation and its relationship to the other elements of the T.120 framework within a single node. + +![Figure 1 – Scope of this Recommendation](01da0d212fb571933f10f96556157745_img.jpg) + +``` + + graph TD + UA_Top[User application\(s\) +\(Using both standard and non-standard application protocols\)] --> UA_Std[User application\(s\) +\(Using std. appl. protocols\)] + UA_Top --> NC[Node controller] + UA_Top --> UA_NonStd[User application\(s\) +\(Using non-std. protocols\)] + + subgraph ITU_T_120_Appl_Protocols [ITU-T T.120 Application protocol Recommendations] + T127[Rec. T.127 \(MBFT\)] + T126[Rec. T.126 \(SI\)] + T128[Rec. T.128 \(AS\) +Application protocol entity] + end + + subgraph NonStd_Protocols [Non-standard application protocol entity] + NS_Entity[...] + end + + UA_Std <--> T127 + UA_Std <--> T126 + UA_Std <--> T128 + NC <--> T128 + NC <--> GCC + UA_NonStd <--> NS_Entity + + subgraph ITU_T_120_Infrastructure [ITU-T T.120 Infrastructure Recommendations] + GCC[Generic Conference Control \(GCC\) +Rec. T.124] + MCS[Multipoint Communications Service \(MCS\) +Rec. T.122/T.125] + NetProt[Network specific transport protocols +Rec. T.123] + GCC <--> MCS + MCS <--> NetProt + end + + T127 <--> GCC + T128 <--> GCC + T128 <--> MCS + NS_Entity <--> GCC + NS_Entity <--> MCS + +``` + +Detailed description of Figure 1: The diagram illustrates the T.120 framework architecture within a single node. At the top is a box for 'User application(s)' using both standard and non-standard protocols. This connects downward to three boxes: 'User application(s) (Using std. appl. protocols)', 'Node controller', and 'User application(s) (Using non-std. protocols)'. Below these are two main protocol entity areas. On the left, 'ITU-T T.120 Application protocol Recommendations' includes stacked boxes for Rec. T.127 (MBFT), Rec. T.126 (SI), and a shaded box for Rec. T.128 (AS) Application protocol entity. On the right, 'Non-standard application protocol entity' is shown as stacked boxes. Both areas connect to the 'ITU-T T.120 Infrastructure Recommendations' section at the bottom, which contains 'Generic Conference Control (GCC) Rec. T.124', 'Multipoint Communications Service (MCS) Rec. T.122/T.125', and 'Network specific transport protocols Rec. T.123' in a vertical stack. Bidirectional arrows show the flow of communication between all these layers. + +**Figure 1 – Scope of this Recommendation** + +Figure 1 – Scope of this Recommendation + +**Rec. ITU-T T.128 (06/2008)**      1 + +# 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T F.710] Recommendation ITU-T F.710 (1991), *General principles for audiographic conference service*. +- [ITU-T H.221] Recommendation ITU-T H.221 (1997), *Frame structure for a 64 to 1920 kbit/s channel in audiovisual teleservices*. +- [ITU-T T.35] Recommendation ITU-T T.35 (1991), *Procedure for the allocation of CCITT defined codes for non-standard facilities*. +- [ITU-T T.50] Recommendation ITU-T T.50 (1992), *International Reference Alphabet (IRA) (Formerly International Alphabet No. 5 or IA5) – Information technology – 7-bit coded character set for information interchange*. +- [ITU-T T.120] Recommendation ITU-T T.120 (2007), *Data protocols for multimedia conferencing*. +- [ITU-T T.121] Recommendation ITU-T T.121 (1996), *Generic application template*. +- [ITU-T T.122] Recommendation ITU-T T.122 (1993), *Multipoint communication service for audiographics and audiovisual conferencing service definition*. +- [ITU-T T.123] Recommendation ITU-T T.123 (1996), *Network-specific data protocol stacks for multimedia conferencing*. +- [ITU-T T.124] Recommendation ITU-T T.124 (1995), *Generic Conference Control*. +- [ITU-T T.125] Recommendation ITU-T T.125 (1994), *Multipoint communication service protocol specification*. +- [ITU-T V.42 bis] Recommendation ITU-T V.42 bis (1990), *Data compression procedures for data circuit-terminating equipment (DCE) using error correcting procedures*. +- [ITU-T X.509] Recommendation ITU-T X.509 (1997) | ISO/IEC 9594-8:1998, *Information technology – Open Systems Interconnection – The Directory: Authentication framework*. +- [ITU-T X.680] Recommendation ITU-T X.680 (1994) | ISO/IEC 8824-1:1995, *Information technology – Abstract Syntax Notation One (ASN.1) – Specification of basic notation*. +- [ITU-T X.691] Recommendation ITU-T X.691 (1997) | ISO/IEC 8825-2:1998, *Information technology – ASN.1 encoding rules – Specification of Packed Encoding Rules (PER)*. +- [ISO/IEC 8859-1] ISO/IEC 8859-1:1998, *Information technology – 8-bit single-byte coded graphic character sets – Part 1: Latin alphabet No. 1*. +<[http://iso.org/iso/iso\\_catalogue\\_tc/catalogue\\_details.htm?csnumber=28245](http://iso.org/iso/iso_catalogue_tc/catalogue_details.htm?csnumber=28245)> +- [ISO/IEC 10646] ISO/IEC 10646:2003, *Information technology – Universal Multiple-Octet Coded Character Set (UCS)*. +<[http://iso.org/iso/iso\\_catalogue\\_tc/catalogue\\_details.htm?csnumber=39921](http://iso.org/iso/iso_catalogue_tc/catalogue_details.htm?csnumber=39921)> + +# 3 Definitions + +This Recommendation defines the following terms: + +**3.1 application sharing (AS):** A process whereby two or more terminals cooperate to share the output of applications running on one or more terminals to the other terminals and to provide input to the applications. + +**3.2 application sharing conference entity (ASCE):** An application protocol entity that interacts with a user application above and with the local multipoint communication service (MCS) and local generic conference control (GCC) providers below to implement application sharing. Data are exchanged between peer ASCEs using application sharing protocol data units (ASPDUs). + +**3.3 bitmap:** A rectangular area described by a two-dimensional array of pixels. These pixels can be coded using a variety of encoding methods. + +**3.4 ColorTable:** A finite set of colours defined by at least three linearly-independent colour primaries. This is a synonym for palette (see definition below), but is used in this Recommendation to reference the particular cached palette associated with cached bitmap data. + +**3.5 desktop:** The logical or physical display area for a particular terminal or window manager advertised by the application sharing conference entity (ASCE) in the application sharing (AS) capabilities. An ASCE may choose to advertise a size corresponding to the actual terminal display area or some other logical display area. + +**3.6 handle:** An application sharing (AS) session-wide unique number used to identify an addressable item. + +**3.7 non-standard capability:** The capability is outside the scope of this Recommendation but it has been determined through negotiation that it is recognized among all session participants. + +**3.8 palette:** A finite set of colours defined by at least three linearly-independent colour primaries. + +**3.9 palettized:** A term used to describe protocol elements (such as bitmap data) comprised of palettized pixels. The colour of a palettized pixel is specified by the colour value at the location in a palette referenced by the pixel value. + +**3.10 pointer:** A bitmap that is moveable over the virtual desktop that is used as an indicator of position. + +**3.11 standard capability:** The capability is defined within the scope of this Recommendation but is not required for all application sharing conference entity (ASCE) implementations. Note that all standard capabilities must be negotiated before use. + +**3.12 unicode:** Multilingual text string format as defined in [ISO/IEC 10646]. + +**3.13 virtual desktop:** A logical desktop that is the largest size of all desktops of hosting application sharing conference entities (ASCEs). + +**3.14 window:** A rectangular area on the desktop corresponding to a user interface display area managed by the terminal window manager. + +**3.15 window manager:** A program executing on the terminal, which is responsible for managing a collection of user interface windows on the terminal desktop. + +# **4 Abbreviations and acronyms** + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-------|----------------------------------------| +| APE | Application Protocol Entity | +| AS | Application Sharing | +| ASCE | Application Sharing Conference Entity | +| ASPDU | Application Sharing Protocol Data Unit | +| GCC | Generic Conference Control | +| ID | Identifier | +| MCS | Multipoint Communication Service | +| SAP | Service Access Point | + +# **5 Overview** + +The AS protocol enables multipoint computer application sharing by allowing a view onto a computer application executing at one site to be advertised within a session to other sites. Each site can, under specified conditions, take control of the shared computer application by sending remote keyboard and pointing device information. This style of application sharing does not require and does not make provision for synchronizing multiple instances of the same computer application running at multiple sites. Instead, it enables remote viewing and control of a single application instance to provide the illusion that the application is running locally. + +An AS session consists of one or more ASCEs which cooperate via the AS protocol to share one or more applications within the session. The AS protocol defines interactions between ASCEs. It does not define interactions between an ASCE and the operating system or input and output devices on the local terminal. + +## **5.1 Legacy and base modes** + +The AS protocol supports two modes of operation. Legacy mode is provided for interoperability with an existing installed base of customer terminal equipment. Base mode provides additional features that enable future AS protocol enhancement. + +All ASCEs compliant with this Recommendation shall implement both legacy and base modes. The AS protocol usage of GCC (see clause 7) is defined such that where all ASCEs in a conference support base mode (i.e., there are no pre-existing legacy mode-only terminals in the conference), then all ASCEs shall use base mode. It is ITU's intention that all future enhancements to the AS protocol shall be by enhancements to base mode. + +A significant proportion of this Recommendation is common to both modes, with the primary differences between the two modes being in the following areas: + +- The manner in which capabilities are exchanged and negotiated: see clause 8.2. +- The manner in which ASCEs are activated and deactivated: see clause 8.4. +- The definition and encoding of ASPDUs: see clause 9. + +Where there are differences between the legacy and base modes of the AS protocol, they are highlighted in the text. + +## 5.2 AS concepts + +### 5.2.1 Desktop and window model + +This Recommendation does not assume or require any particular local terminal equipment or terminal environment, nor does it assume or require a particular local terminal window manager or windowing model. For example, it does not assume: + +- that the terminal equipment is a PC or workstation – it may be a dedicated terminal; +- that AS protocol windows correspond to windows managed by a terminal window manager – they may map onto arbitrary areas of the local terminal display; +- that AS protocol desktops correspond to local terminal displays – they may map into local browser or viewer windows, or onto dedicated terminal display areas. + +While this Recommendation does not assume or require any particular local terminal equipment or terminal environment, the AS protocol does define a logical desktop and window model – consisting of a collection of windows on a desktop. This requires that each active ASCE within an AS session is capable of mapping local terminal environment concepts to and from the AS protocol desktop and window model. The AS protocol desktop and window model supports the following key concepts: + +- **Desktop** The AS desktop is a rectangle defined in virtual desktop coordinates. An ASCE should provide a mapping from the AS desktop to an appropriate local terminal concept. +- **Virtual desktop** The virtual desktop is the union of the sizes of the desktops of hosting ASCEs (i.e., ASCEs that are hosting windows – see below). The virtual desktop origin (i.e., pixel 0,0) is defined as being at (top, left). +- **Window** An AS window is a rectangle defined in virtual desktop coordinates. AS windows may be wholly within, partially within or wholly outside the virtual desktop. An ASCE should provide a mapping from AS windows to an appropriate local terminal window concept. +- **Z-order** The AS window Z-order defines a window depth ordering between windows on the virtual desktop, such that for two windows, the window higher in the Z-order is in front of and/or may obscure the other. +- **Top-most** The top-most AS window in the Z-order is in front of and/or may obscure all other windows in the Z-order. +- **Bottom-most** The bottom-most AS window in the Z-order is behind and/or may be obscured by all other windows in the Z-order. + +Further AS protocol concepts are explained below or in the appropriate protocol description clauses. + +Figure 2 shows an example collection of ASCEs within an AS session – this figure is used throughout this clause to illustrate key AS protocol concepts. + +- ASCE A is full function, viewing and hosting – that is, it both shares windows into the AS session and displays shadow windows shared from other ASCEs. It is executing on a general purpose PC, where the AS desktop and AS windows are mapped directly onto the terminal window manager's desktop. +- ASCE B is viewing only – that is, it displays shadow windows shared from other ASCEs but does not itself share windows into the AS session. It is executing on a specialized viewing terminal where the AS desktop and AS windows are mapped into an independently sizeable browser/viewer window, which is (currently) smaller than the AS desktop and is scrolled as required to view the entire AS desktop. + +- ASCE C is hosting only – that is, it shares windows into the AS session, but does not display shadow windows. It is executing on a high-end unattended workstation, where the AS desktop and AS windows are mapped directly onto the terminal window manager's desktop. + +![Figure 2: Example collection of ASCEs within an AS session. The diagram illustrates the architecture of three ASCEs (A, B, and C) and their interactions. ASCE A is at the top, ASCE B (viewing only) is at the bottom left, and ASCE C (hosting only) is at the bottom right. Each ASCE has a 'desktop' and a 'display' area. ASCE A's desktop contains 'A hosted' and 'A local' windows, while its display shows 'C shadow' and 'A local'. ASCE B's desktop shows 'A shadow', 'C shadow', and 'A local', and its display includes a 'B browser/viewer' with 'A shadow', 'B local', and 'C shadow'. ASCE C's desktop contains 'C hosted', and its display shows 'C hosted' and 'C local'. Arrows indicate data flow: 'A output to B, C' from ASCE A to both ASCE B and ASCE C; 'B input to C' from ASCE B to ASCE C; and 'C output to A, B' from ASCE C to both ASCE A and ASCE B. Dashed lines represent the mapping between desktop and display areas for each ASCE.](007b053fe94a8348f75128a584503fd0_img.jpg) + +T1602320-97 + +Figure 2: Example collection of ASCEs within an AS session. The diagram illustrates the architecture of three ASCEs (A, B, and C) and their interactions. ASCE A is at the top, ASCE B (viewing only) is at the bottom left, and ASCE C (hosting only) is at the bottom right. Each ASCE has a 'desktop' and a 'display' area. ASCE A's desktop contains 'A hosted' and 'A local' windows, while its display shows 'C shadow' and 'A local'. ASCE B's desktop shows 'A shadow', 'C shadow', and 'A local', and its display includes a 'B browser/viewer' with 'A shadow', 'B local', and 'C shadow'. ASCE C's desktop contains 'C hosted', and its display shows 'C hosted' and 'C local'. Arrows indicate data flow: 'A output to B, C' from ASCE A to both ASCE B and ASCE C; 'B input to C' from ASCE B to ASCE C; and 'C output to A, B' from ASCE C to both ASCE A and ASCE B. Dashed lines represent the mapping between desktop and display areas for each ASCE. + +**Figure 2 – Example collection of ASCEs within an AS session** + +Within an AS session, windows are of the following types: + +- Hosted: Hosted windows are owned by an application executing on the local terminal and are shared into the AS session. For each hosted window, there will be a corresponding shadow window on each peer ASCE (except for the case where an ASCE is hosting only). +- Shadow: Shadow windows are drawn by the ASCE and correspond to a hosted window on a particular peer ASCE. +- Local: Local windows are not shared – their output is only visible on the local terminal. An ASCE is only required to track local windows where they obscure a hosted window and where that obscuring prevents the ASCE obtaining valid drawing information for the hosted window. + +Figure 2 shows (for each ASCE) both the local windows on the actual terminal display and the AS windows on the AS desktop that the ASCE manages via the AS protocol. + +- ASCE A is managing three windows: + - a shadow window corresponding to the hosted window on ASCE C; + - a hosted window which is shared into the AS session; + - a local window – because it obscures the hosted window and on the local terminal that prevents it obtaining valid drawing information for that hosted window. + +Shadow window C is drawn on the local terminal display by the ASCE – and the other two windows are displayed by the local terminal. + +- ASCE B is also managing three windows: + - a shadow window corresponding to the hosted window on ASCE A; + - a shadow window corresponding to the hosted window on ASCE C; + - the local window from ASCE A – because it obscures the hosted window on ASCE A; + - ASCE B does not track the local windows on its terminal display as it does not host windows. + +Shadow windows A and C are drawn into the browser/viewer window on the local terminal display by the ASCE. The local window is not drawn, but is rather used to compute and draw an obscuring area, which partially obscures shadow window A (shown as a dark area at the bottom right of shadow window A). + +- ASCE C is managing one window: + - a hosted window which is shared into the AS session; + - ASCE C does not track the shadow window corresponding to the hosted window on ASCE A as it does not view shadow windows; + - ASCE C does not track its local window, as, while the local window does obscure the hosted window, the local terminal allows it to obtain valid drawing information for that hosted window. + +The hosted window is displayed by the local terminal. + +See clause 8.10 for further information on windows and window list management. + +### 5.2.2 Output + +When an ASCE is hosting a window, it is responsible for constructing an output stream for that window which will allow other ASCEs to faithfully draw corresponding shadow windows. + +The AS output protocol stream is multicast via the AS-CHANNEL to all other active ASCEs within the conference. If an ASCE is hosting only (as is ASCE C in Figure 2), then it can ignore some or all of the output stream. Similarly, a receiving ASCE may decide to draw only a subset of the output stream based on its source (e.g., only draw windows from a particular ASCE). + +An ASCE determines the allowable output repertoire based on the current negotiated capabilities. This requires that the ASCE is capable of adjusting its output strategy as ASCEs with lower or higher capabilities join and/or leave the conference. But within the current allowable repertoire, and the inherent constraints of the AS protocol, an ASCE has considerable freedom in constructing an output stream. + +The output stream consists of: + +- state information – such as window list information (see clause 8.10); +- color information – such as palette and cached ColorTable information (see clauses 8.15 and 8.16.8); + +- orders and bitmap data (see clauses 8.16 and 8.17). + +The AS protocol supports the following primary orders: + +- Destination Blt. +- Pattern Blt. +- Screen Blt. +- Memory Blt. +- Memory three-way Blt. +- Text. +- Extended text. +- Frame. +- Rectangle. +- Line. +- Opaque rectangle. +- Desktop save. +- Desktop origin. + +In typical application sharing scenarios, orders constitute a very high proportion of ASPDU traffic. Orders may therefore be differentially encoded to reduce the volume of orders in the output stream – this process is referred to as order encoding. + +The AS protocol supports a single bitmap data format, which may be compressed using an AS-specific two-dimensional run-encoding bitmap compression algorithm. + +Depending on local application drawing activity into hosted windows and on flow control (see clause 8.5), a hosting ASCE may use a range of strategies to reduce the volume of the output stream and/or retain responsiveness of remote drawing. Possible strategies include the following: + +- Switching between sending orders and bitmap data: +Where a local application is very actively drawing into a hosted window and the ASCE is experiencing flow control back pressure, the ASCE may prefer to accumulate bounds information for the drawing activity, rather than sending the orders, and then subsequently send bitmap data for the accumulated bounds. This may reduce the frequency of updates at remote ASCEs, but will minimize the data in flight and ensures that remote ASCEs "keep up" with the drawing activity. The switching points between orders and bitmap data and vice versa will depend on application drawing behaviour, flow control and the particular ASCE implementation. +- Collapsing overlapping updates – this process is referred to as spoiling: +Where the ASCE is experiencing flow control back pressure and the local application draws a sequence of overlapping or occluding order or bitmap data updates, then the sequence may (in some cases) be collapsed into a smaller sequence and/or a single update. Again, this may reduce the frequency of updates at remote ASCEs, but will minimize the data in flight and ensure that remote ASCEs "keep up" with the drawing activity. + +A hosting ASCE is required to ensure that the final constructed output stream allows receiving ASCEs to correctly draw the corresponding shadow windows. Similarly, where the output stream relies on control information (such as window list or palette information) that has changed on the hosting ASCE, it is the hosting ASCE's responsibility to ensure that the control information is sent prior to the output. All order-dependent control and output ASPDUs are sent at low priority, so that the sending ASCE can reliably order such output. + +### 5.2.3 Control and input + +Within an AS session, control is managed via a combination of conductorship, the core control protocol and (where negotiated) the mediated control protocol – see clauses 8.19, 8.12 and 8.13, respectively. Conductorship has preference, in that where the conference is in conducted mode, the AS-specific control protocols are not used (other than to enforce conductorship). Where conductorship is not in force, then control is managed via a combination of the core control protocol and (where negotiated) the mediated control protocol. + +A key common concept to these control schemes is that, at any point in time within the AS session, one ASCE is in control and has the right to provide input to hosted and/or shadow windows1. + +Where an ASCE is in control and can provide input to hosted or shadow windows (depending on whether it or other ASCEs are detached or not), then, when a local input event occurs, the ASCE determines, based on its local window structure and the shared window structure on its logical desktop, whether that event is for a local, hosted or shadow window. Where the event is for a local or hosted window, then the ASCE can defer processing of the event to the local terminal. Where the event is for shadow window, then the ASCE determines which peer ASCE owns the corresponding hosted window and constructs a suitable input stream for that ASCE. + +The AS input stream consists of interleaved keyboard and pointing device events. Keyboard events may be represented either as codepoints or as virtual keycodes. Pointing device events are represented as a logical three-button pointing device. See clause 8.18 for further information. + +Where an ASCE is experiencing flow control back pressure (see clause 8.5) and there is a high level of end-user pointing device activity, the ASCE may collapse a sequence of pointing device move events into a single move – this process is referred to as input spoiling. Input spoiling may also be applied at the hosting ASCE, where a sequence of pointing device events is queued within the ASCE awaiting injection into the local terminal environment. Both send and receive input spoiling may reduce the frequency of pointing device move updates presented to hosted windows and therefore degrade the smoothness of pointing device movement, but will minimize the data in flight and ensure that remote ASCEs "keep up" with the pointing device activity. + +### 5.2.4 Colour + +The AS protocol carries colour information for the processing of orders and bitmap data. + +- For orders (with the exception of the memory Blt and memory three-way Blt orders – see below) colour information is embedded in the order itself – although it may be absent on individual orders as a result of order encoding. +- Bitmap data is always palettized and is interpreted with reference to a previously sent palette which contains the colour information. +- For the memory Blt and memory three-way Blt orders, the order contains some of the required colour information, but also refers to cached bitmap data (as the source for the operation), where that cached bitmap data (see clause 8.16.7) is always palettized and is interpreted with reference to a previously cached ColorTable (see clause 8.16.8) which contains the colour information. + +In the legacy mode of the AS protocol, colour information is expressed solely as RGBs. In base mode, colour information is expressed as RGBs with optional colour accuracy information. + +--- + +1 This Recommendation does not specify control behaviour with respect to local ASCE windows. + +ASCEs may supply colour space information: + +- within palettes: where the colour space only applies to that palette; +- within ColorTables in cache ColorTable orders: where the colour space only applies to that cached ColorTable; +- in colour space orders: where the colour space applies to subsequent orders. + +The AS protocol does not mandate a particular colour mapping between the ASCE and the local terminal, although ASCEs should attempt to maintain colour fidelity (within the constraints of the negotiated capabilities) when constructing and interpreting colour-related information in the output stream. + +### 5.2.5 Coordinates and clipping + +All coordinates in the AS protocol are in virtual desktop coordinates. The virtual desktop is the union of the sizes of the desktops of hosting ASCEs (i.e., ASCEs that are hosting windows) and is regarded as the common drawing area in use by hosting ASCEs. The virtual desktop origin (i.e., pixel 0,0) is defined as being at (top, left). + +An ASCE shall clip all AS protocol coordinates and rectangles to the virtual desktop. The AS protocol does not mandate a particular clipping strategy with respect to the local terminal display area. + +All rectangles in the AS protocol are inclusive. That is, the right-most and bottom-most pixel coordinates represent pixels that are within the rectangle. For example, a rectangle with coordinates (10,10,19,19) is 10 by 10 pixels in size. + +# 6 Use of MCS + +All T.128 communication shall be through MCS as specified in [ITU-T T.122]. This clause details specific use of MCS services, channel allocation and data priorities. This Recommendation complies with the mechanisms described in [ITU-T T.121] regarding proper operations for standard base sessions, non-standard base sessions and the registration session. All other session types are optional. + +An ASCE uses the MCS service primitives described in Table 6-1 to attach and detach from a domain, join and leave the AS channel, and send and receive ASPDUs. + +**Table 6-1 – MCS primitives needed by an ASCE** + +| MCS primitive | Description | +|----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| MCS-ATTACH-USER | Creates an MCS attachment through an MCS SAP to a domain hosted by the MCS provider. A result is confirmed to the requester. If the request is accepted, a user ID is assigned. | +| MCS-DETACH-USER | Deletes an MCS attachment that was created previously by invocation of MCS-ATTACH-USER. This primitive may be requested by a user or initiated by a provider. It delivers an indication at every other MCS attachment to the same domain. If provider-initiated, an indication is also delivered at the deleted attachment. | +| MCS-CHANNEL-JOIN | Used by an application client to join an appropriate channel whose use is defined by the application. This is a prerequisite for receiving data sent to the channel. | + +**Table 6-1 – MCS primitives needed by an ASCE** + +| MCS primitive | Description | +|----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| MCS-CHANNEL-LEAVE | Used by an application client to leave a previously joined channel and thus stop receiving data sent to that channel. The primitive may be user-initiated (request only) or provider-initiated (indication to affected user only). | +| MCS-SEND-DATA | Used to transmit data to other members of a domain. If the sender is a member of the destination channel, it will not receive its own data indications. However, it will receive data indications from other sources addressed to that channel. | + +MCS request primitives are directed from the ASCE to the MCS provider, while indication primitives are directed from the MCS provider towards the ASCE. Additional detail on the MCS primitives described above can be found in [ITU-T T.122]. + +## 6.1 MCS channel usage + +Table 6-2 describes MCS channel usage for ASCE sessions of the types defined in [ITU-T T.121]. In the case of a standard base session (see [ITU-T T.121]) which uses the base mode of the AS protocol, the channel IDs shown in Table 6-2 shall be used (symbolic IDs shown). For all other session types, the application registry resource IDs shown in the table shall be used for allocating dynamic channels. The given resource IDs shall be encoded as three-octet T.50 text strings using the characters shown in quotes in Table 6-2. + +**Table 6-2 – Description of AS channels** + +| Mnemonic | Channel IDs for static channel | Application registry resource IDs for dynamic channels | Description | +|--------------------------|---------------------------------------|---------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------| +| AS-{MCS-USER-ID}-CHANNEL | – | – | Certain ASPDUs are sent directly to individual ASCEs. To do this, the individual MCS-USER-ID channels of the peer ASCEs in the MCS domain are used. | +| AS-CHANNEL | AS-CHANNEL-0 | "421" | This channel bears all ASPDUs to be broadcast to all peer ASCEs in a domain. | + +## 6.2 Use of MCS data services + +Table 6-3 lists the use of the MCS data service MCS-SEND-DATA for each ASPDU (with mode-specific ASPDUs indicated where necessary). ASCEs do not use the MCS data service MCS-UNIFORM-SEND-DATA. This table includes the channel over which the data are sent and the data priority at which the data are sent. + +The AS protocol uses three MCS priorities as a means of segregating ASPDUs with respect to flow control. Flow control is applied on a per-channel and per-priority basis (see clause 8.5), such that grouping ASPDUs by priority allows the application of a flow control regime that is applicable to the group, as follows: + +- High priority is flow controlled and is used for activation, flow control and input ASPDUs. +- Medium priority is not flow controlled and is used for control ASPDUs. + +- Low priority is flow controlled and is used for window information and output ASPDUs. + +All ASPDUs specified in this Recommendation are placed in the data parameter of the MCS-SEND-DATA primitive. The ASPDUs are packed into the sequence of octets that form the data parameter such that the leading bit is placed in the most significant bit of each octet, and filled toward the least significant bit of the octet. + +**Table 6-3 – Use of MCS data primitives for ASPDUs** + +| ASPDU | Channel | Modes | Priority | +|---------------------|--------------------------------------------------|--------------|------------------------------| +| ApplicationPDU | AS-CHANNEL or AS- {MCS-USER-ID}-CHANNEL (Note 1) | Both | Medium | +| ConfirmActivePDU | AS-CHANNEL | Legacy mode | All (Note 2) | +| ControlPDU | AS-CHANNEL | Both | Medium | +| DeactivateAllPDU | AS-CHANNEL | Legacy mode | High | +| DeactivateOtherPDU | AS- {MCS-USER-ID}-CHANNEL | Legacy mode | High | +| DeactivateSelfPDU | AS-CHANNEL | Legacy mode | High | +| DemandActivePDU | AS-CHANNEL | Legacy mode | High | +| FlowResponsePDU | AS- {MCS-USER-ID}-CHANNEL | Both | High | +| FlowStopPDU | AS-CHANNEL | Both | High | +| FlowTestPDU | AS-CHANNEL | Both | High, medium or low (Note 3) | +| FontPDU | AS-CHANNEL | Both | Medium | +| InputPDU | AS-CHANNEL | Both | High | +| MediatedControlPDU | AS-CHANNEL or AS- {MCS-USER-ID}-CHANNEL (Note 4) | Both | Medium | +| PointerPDU | AS-CHANNEL | Both | Medium | +| RemoteSharePDU | AS- {MCS-USER-ID}-CHANNEL | Both | Medium | +| RequestActivePDU | AS- {MCS-USER-ID}-CHANNEL | Legacy mode | High | +| SynchronizePDU | AS-CHANNEL | Both | All (Note 5) | +| UpdateCapabilityPDU | AS- {MCS-USER-ID}-CHANNEL | Legacy mode | Medium | +| UpdatePDU | AS-CHANNEL | Both | Low | + +**Table 6-3 – Use of MCS data primitives for ASPDUs** + +| ASPDUs | Channel | Modes | Priority | +|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------|-------|----------| +| WindowActivationPDU | AS-CHANNEL or AS- $\{MCS-USER-ID\}$ -CHANNEL (Note 6) | Both | Low | +| WindowListPDU | AS-CHANNEL | Both | Low | +|

NOTE 1 – The ApplicationPDU (NotifyHostedApplications) is sent on the AS-CHANNEL and the ApplicationPDU (UnhostApplication) is sent on a particular AS-\{MCS-USER-ID\}-CHANNEL. See clause 8.9 for further information.

NOTE 2 – The ConfirmActivePDU is sent on all priorities. See clause 8.4.1 for further information.

NOTE 3 – The FlowTestPDU is sent on the particular priority for which flow control is being applied. See clause 8.5 for further information.

NOTE 4 – The MediatedControlPDU is sent on either the AS-CHANNEL or a particular AS-\{MCS-USER-ID\}-CHANNEL. See clause 8.13 for further information.

NOTE 5 – The SynchronizePDU is sent on one of the high, medium or low priorities, as required. See clause 8.6 for further information.

NOTE 6 – WindowActivationPDU indications are sent on the AS-CHANNEL and WindowActivationPDU requests are sent on a particular AS-\{MCS-USER-ID\}-CHANNEL. See clause 8.11 for further information.

| | | | + +# 7 Use of GCC + +The legacy mode of the AS protocol shall use the procedures of a non-standard base session in the manner specified in [ITU-T T.121] and shall use the application protocol key defined in Annex B. The base mode of the AS protocol may use the procedures defined for a registration session, a standard base session, a public session, or a private session in the manner specified in [ITU-T T.121] and shall use as its application protocol key the object identifier defined in Annex C. + +All ASCEs compliant with this Recommendation shall first enrol actively or inactively in the registration session (to signal support for the base mode of the AS protocol) and then enrol actively or inactively in the non-standard base session (to signal support for the legacy mode of the AS protocol), in both cases using the procedures defined in [ITU-T T.121], and shall stay enrolled in both sessions for as long as support for the AS protocol is to be indicated. + +Pre-existing terminal equipment that only provides support for legacy mode will only enrol actively or inactively in the non-standard base session using the procedures defined in [ITU-T T.121] and will stay enrolled in that session for as long as such support is to be indicated. + +An ASCE shall not enrol in the standard base session of the AS protocol unless for each node in a conference, there are an equal number of ASCEs enrolled either actively or inactively in the non-standard base session as there are enrolled in the registration session. + +If the non-standard base session is in progress (i.e., all ASCEs are active in legacy mode), upon receiving a GCC-Conference-Roster-Report indication where the number of ASCEs enrolled in the registration session is equal to the number of ASCEs enrolled in the non-standard base session in the conference (i.e., all ASCEs in the conference are compliant), all ASCEs shall become inactive in legacy mode, shall enrol in the standard base session and shall become active in base mode. See clause 8.4 for further information on ASCE activation. + +If the standard base session is in progress (i.e., all ASCEs are active in base mode), upon receiving a GCC-Conference-Roster-Report indication where the number of ASCEs enrolled in the registration session is less than the number of ASCEs enrolled in the non-standard base session in the conference (i.e., one or more ASCEs in the conference are non-compliant pre-existing terminal + +equipment), all ASCEs enrolled in the standard base session shall become inactive in base mode, shall unenroll from the standard base session and shall become active in legacy mode. See clause 8.4 for further information on ASCE activation. + +The above rules for switching between legacy and base modes mean that legacy mode will only be in effect where the conference contains pre-existing terminal equipment supporting the legacy mode of the AS protocol only. Where all ASCEs in the conference comply with this Recommendation, then base mode will be in effect. Given this, the switch from base to legacy mode occurs when the first legacy-only mode node joins a conference consisting entirely of ASCEs that are compliant with this Recommendation. In contrast, the switch from legacy mode to base mode occurs when the last legacy only mode node leaves a conference which then consists entirely of ASCEs that are compliant with this Recommendation. + +ASCES supporting the base mode of the AS protocol may enrol in a public session or private session at their discretion using the procedures defined in [ITU-T T.121]. + +# **8 Protocol specification** + +## **8.1 AS sessions** + +An AS session consists of one or more ASCES enrolled within a conference as described in clause 7. ASCES may join or leave the AS session at any time. + +## **8.2 Capabilities** + +AS capabilities are collected into capability sets, where each set consists of related individual capabilities. Capability sets are described in Tables 8-3 through 8-20. Hereafter, where this Recommendation makes reference to an individual capability, it uses the notation **capability\_set.capability**. For example Bitmap.desktopWidth refers to the desktopWidth capability in the Bitmap capability set. + +The full list of capability sets is referred to as an ASCE's combined capabilities. The combined capabilities list contains one copy of each of the corresponding capability sets in any order. + +- General capability set: See clause 8.2.3. +- Bitmap capability set: See clause 8.2.4. +- Order capability set: See clause 8.2.5. +- Bitmap cache capability set: See clause 8.2.7. +- ColorTable cache capability set: See clause 8.2.8. +- Window activation capability set: See clause 8.2.9. +- Control capability set: See clause 8.2.10. +- Pointer capability set: See clause 8.2.11. +- Share capability set2: See clause 8.2.12. + +In the legacy mode of the AS protocol, an ASCE may define non-standard capability extensions by adding private capability sets and/or by adding private capabilities at the end of the defined capability sets. The interpretation of such capabilities is not covered by this Recommendation. When using the legacy mode of the AS protocol, an ASCE should ignore unrecognized non-standard capability sets and unrecognized capability set extensions. Similarly, an ASCE shall + +--- + +2 The share capability set is only defined for the legacy mode of the AS protocol. It does not form part of an ASCE's combined capabilities in the base mode of the AS protocol. + +treat any private capabilities that are not supplied by other ASCEs as zero (for integer values) or FALSE (for logical and bit flag values). + +In the base mode of the AS protocol, an ASCE may define non-standard capability extensions by adding one or more non-standard capability sets (see clause 8.2.13) to its combined capabilities. The interpretation of such capabilities is not covered by this Recommendation. + +### **8.2.1 Distribution of capabilities** + +For the legacy mode of the AS protocol, an ASCE advertises its combined capabilities during ASCE activation on the following ASPDUs. + +- DemandActivePDU: See clause 8.4.1. +- RequestActivePDU: See clause 8.4.1. +- ConfirmActivePDU: See clause 8.4.1. + +For the legacy mode of the AS protocol, an ASCE advertises a change in a particular capability set using the UpdateCapabilityPDU (see clause 8.2.14). + +For the base mode of the AS protocol, capabilities exchange shall be performed according to [ITU-T T.121], via the application enrolment mechanism. An ASCE shall use GCC-Application-Enroll requests to enrol and advertise its current combined capabilities. Where an ASCE's capabilities change while enrolled, it shall re-enrol by issuing a GCC-Application-Enroll request with the Enroll/Unenroll flag set to Enroll, including the revised combined capabilities. ASCEs receive collapsed and non-collapsed application capabilities, generated from the combined capabilities supplied by all enrolled ASCEs, via GCC-Application-Roster-Report indications. An ASCE may be required to process GCC-Application-Roster-Report indications multiple times during an AS session and shall adhere to the bounds imposed by the capabilities reported in this fashion. + +### **8.2.2 Capabilities negotiation** + +In the legacy mode of the AS protocol, the ASCE activation ASPDU exchanges (see clause 8.4.1) ensure that an ASCE has a copy of each other active ASCE's capabilities. And, in addition, an ASCE is responsible for performing all capabilities negotiation. That is, GCC is not involved in capabilities distribution or negotiation. + +In the base mode of the AS protocol, capabilities are distributed by GCC. There are a small number of capabilities that must be advertised via the non-collapsing capabilities list in the roster – they are specified as such in the description of the capability in the appropriate base mode capability set. However, in general, a particular capability may be advertised via one of either the collapsing or non-collapsing capabilities lists in the roster. Where an ASCE advertises a particular capability via one list, it shall not advertise the same capability via the other list. However, an ASCE is not required to advertise a capability – it may choose not to advertise a particular capability in either list and rely on the defined GCC roster counting behaviour to force use of a default value (see below). + +This hybrid approach to base mode capabilities distribution is provided so that ASCEs may advertise capabilities via the collapsing capabilities, which results in a reduction in roster-related GCC traffic, but may still advertise capabilities via the non-collapsing capabilities where that is more appropriate. ASCEs are recommended to use collapsing capabilities wherever possible. + +In the base mode of the AS protocol, where an ASCE advertises a particular capability via the non-collapsing capabilities list in the roster, the ASCE shall encode the capability value using the encoding rules defined in clause 9.4. + +ASCE capabilities negotiation for a particular capability depends on the defined capability negotiation rule for that capability, the protocol mode (i.e., whether the ASCE is using legacy or + +base mode) and whether (in base mode) the capability is advertised via collapsing or non-collapsing capabilities. + +#### 8.2.2.1 One and info capability rules + +Where the defined capability negotiation rule is one or info, then an ASCE shall process the advertised capabilities as follows. + +In base mode, where a capability is negotiated using either the one or info rules, the capability shall be advertised using non-collapsing capabilities. + +| Rule | Required ASCE processing | +|------|---------------------------------------------------------------------------------------------------------------------------------------------------| +| One | The negotiated capability value is the value advertised by a particular peer ASCE. | +| Info | Capabilities may also be classified as informational – they are provided solely for informational or diagnostics purposes and are not negotiated. | + +#### 8.2.2.2 Min and max capability rules + +Where the defined capability negotiation rule is min or max, then an ASCE shall process the advertised capabilities based on the number of candidate values, as follows: + +- For the legacy mode of the AS protocol, candidate values correspond to the advertised values supplied by each active ASCE during ASCE activation, but excluding the value advertised by the negotiating ASCE. If there are N active ASCEs, then there are N–1 candidate values. +- For the base mode of the AS protocol, candidate values consist of the collapsed capability value provided in the roster and any non-collapsing values, but excluding a non-collapsing value advertised by the negotiating ASCE. The roster indicates how many ASCEs advertised capability values contributed to the collapsed value, which allows an ASCE to determine whether all ASCEs advertised a value. So, if there are N ASCEs in the roster, C ASCEs advertised collapsing values and NC ASCEs advertised non-collapsing values for a particular capability, then: + - if $N = C$ , all ASCEs advertised collapsing values for the particular capability: there is one candidate value; + - if $N = NC$ , all ASCEs advertised non-collapsing values for the particular capability: there are NC–1 candidate values – where the non-collapsing value advertised by the negotiating ASCE is excluded; + - if $N = C + NC$ , all ASCEs advertised either a collapsing or non-collapsing value for the particular capability: there are: + - $C + NC - 1$ candidate values where the negotiating ASCE advertised a non-collapsing value which is excluded; + - $C + NC$ candidate values where the negotiating ASCE advertised a collapsing value; + - if $N > C + NC$ , not all ASCEs advertised a value: the negotiated capability value is the default value (see below). + +In base mode, if an ASCE determines that all ASCEs have advertised collapsing values (i.e., case $N = C$ above), then the negotiated capability value is the collapsed value in the roster. + +In base mode, if an ASCE determines that not all ASCEs advertised a value (i.e., case $N > C + NC$ above), then the negotiated capability value is the default value. For logical capabilities, the default value is FALSE (or not established). For integer capabilities, the default value is specified in the description of the capability in the appropriate base mode capability set. + +For legacy mode, or for base mode where all ASCEs advertised values and the number of candidate values is greater than one (i.e., some or all ASCEs advertised non-collapsing values – cases $N = NC$ and $N = C + NC$ above), then the ASCE applies the defined min or max capability negotiation rule, as follows. + +| Rule | Required ASCE processing | +|------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Min |

The negotiated capability value is the minimum of the candidate values:

  • For integer values, the minimum is the lowest integer value.
  • For logical values, the minimum is FALSE.
  • For bit flags (in legacy mode only), each bit flag is negotiated independently and the minimum is not set.
| +| Max |

The negotiated capability value is the maximum of the candidate values:

  • For integer values, the maximum is the highest integer value.
  • For logical values, the maximum is TRUE.
  • For bit flags (in legacy mode only), each bit flag is negotiated independently and the maximum is set.
| + +#### 8.2.2.3 Group capability rules + +ASCE capabilities negotiation is generally performed on single capability values. However, there are cases where a number of capabilities are negotiated as a group – for example, negotiation of the bitmap capability set bits-per-pixel related capabilities (see clause 8.2.4). Where this is the case, an individual capability in the group may be negotiated either by using one of the previously described capability negotiation rules – such as min or max – with the negotiated value being fed into the group negotiation, or by feeding its unnegotiated value directly into the group negotiation. + +Where capabilities are negotiated as a group, they are identified as such in the particular capability set together with a reference to the specific rule used to negotiate the group. + +Table 8-1 summarizes the notation used in the remainder of this clause when describing capabilities. + +**Table 8-1 – Capability notation – Classes** + +| Class | Description | +|-------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| L | Logical: A logical value. In legacy mode, the value is either TRUE or FALSE. In base mode, if the capability is supplied, the value is TRUE. In base mode, the default value is FALSE. | +| F | Bit flags: A collection of bit values, each of which is TRUE or FALSE. This class is only allowed in legacy mode capability sets. | +| N | Integer: A signed or unsigned integer value. In base mode, the default value is as specified in the description of the capability set. | +| S | String: A null-terminated T.50 text string. This class is only allowed in legacy mode capability sets. | + +Table 8-2 illustrates example capability negotiations. Each row shows, for each ASCE (ASCEs 1 and 2), the capability value set (for each class) by the ASCE when advertising its capabilities, the resultant values for the one rule with respect to the other ASCEs and the negotiated value for the min and max rules for the cases where all ASCEs advertise using collapsing capabilities and where all advertise using non-collapsing capabilities (which gives four combinations: min (C) is the min + +rule and all advertise using collapsing capabilities, min (NC) is the min rule and all advertise using non-collapsing capabilities, and so on ...)³. For example: + +- ASCE 1's advertised logical value is TRUE, its bit flag value is 0x0001 and its integer value is 100. +- ASCE 2's advertised logical value is FALSE, its bit flag value is 0x0003 and its integer value is 300. +- When ASCE 1 applies the one rule with respect to ASCE 2, it generates ASCE 2's advertised values – i.e., FALSE, 0x0003 and 300 respectively. +- When ASCE 1 applies the max rule for the case where both ASCEs advertised using collapsing capabilities, it generates the maximum of all advertised values – i.e., TRUE and 300 respectively. +- When ASCE 1 applies the max rule for the case where both ASCEs advertised using non-collapsing capabilities, it generates the maximum of all advertised values excluding its own – i.e., FALSE, 0x0003 and 300 respectively. +- When ASCE 2 applies the one rule with respect to ASCE 1, it generates ASCE 1's advertised values – i.e., TRUE, 0x0001 and 100 respectively. + +This is not an exhaustive example. The itemized cases cover four out of the ten example cases. In addition, there are further combinations where ASCEs provide mixed collapsing and non-capabilities. + +**Table 8-2 – Example capability negotiation** + +| Class | ASCE 1 | | | | | | ASCE 2 | | | | | | +|-------|--------|--------|---------|----------|---------|----------|--------|---------|---------|----------|---------|----------| +| | Value | One ⇒2 | Min (C) | Min (NC) | Max (C) | Max (NC) | Value | 1 ⇐ One | Min (C) | Min (NC) | Max (C) | Max (NC) | +| B | T | F | F | F | T | F | F | T | F | T | T | T | +| F | x0001 | x0003 | n/a | x0003 | n/a | x0003 | x0003 | x0001 | n/a | x0001 | n/a | x0001 | +| N | 100 | 300 | 100 | 300 | 300 | 300 | 300 | 100 | 100 | 100 | 300 | 300 | + +### 8.2.3 General capability set + +The general capability set provides capabilities for the general characteristics of the issuing ASCE. See Tables 8-3 and 8-4. + +**Table 8-3 – General capability set (legacy mode)** + +| Capability | Description | Class | Rule | +|--------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|------| +| OSMajorType |

This capability indicates the operating system major type. Allowable values are as follows:

  • • Unspecified.
  • • Windows.
  • • OS/2.
  • • Macintosh.
  • • UNIX/X.

This capability is for information and diagnostic purposes only.

| N | Info | + +3 The bit flag class is only allowed in legacy mode, where the distribution of capabilities via the ASCE activation ASPDUs is equivalent to advertising via non-collapsing capabilities. Therefore, the bit flag class resultant values for min and max collapsing capability cases are not shown. + +**Table 8-3 – General capability set (legacy mode)** + +| Capability | Description | Class | Rule | | | | | | | | | | | | | +|--------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------|-------------|---------|---------------------------------------------------------|------|-------------------------------------------------|-----------|-------------------------------------|--------|-----------------------------------------------|-------------|-------------|---|------| +| OSMinorType |

This capability indicates the operating system minor type. The values depend on the OSMajorType capability (see above). Allowable values are as follows:

OSMajorType OSMinorType
Windows Unspecified
Windows 3.1x
Windows 95
Windows NT
OS/2 Unspecified
OS/2 Warp (Intel x86)
PowerPC
Macintosh Unspecified
Macintosh
PowerPC
UNIX/X Unspecified
Native server
Pseudo server
Unspecified Unspecified

This capability is for information and diagnostic purposes only.

| OSMajorType | OSMinorType | Windows | Unspecified
Windows 3.1x
Windows 95
Windows NT | OS/2 | Unspecified
OS/2 Warp (Intel x86)
PowerPC | Macintosh | Unspecified
Macintosh
PowerPC | UNIX/X | Unspecified
Native server
Pseudo server | Unspecified | Unspecified | N | Info | +| OSMajorType | OSMinorType | | | | | | | | | | | | | | | +| Windows | Unspecified
Windows 3.1x
Windows 95
Windows NT | | | | | | | | | | | | | | | +| OS/2 | Unspecified
OS/2 Warp (Intel x86)
PowerPC | | | | | | | | | | | | | | | +| Macintosh | Unspecified
Macintosh
PowerPC | | | | | | | | | | | | | | | +| UNIX/X | Unspecified
Native server
Pseudo server | | | | | | | | | | | | | | | +| Unspecified | Unspecified | | | | | | | | | | | | | | | +| protocolVersion | This capability specifies the protocol version level. The allowable value is 0x0200 (indicating major and minor versions of 2 and 0 respectively). | N | Info | | | | | | | | | | | | | +| generalCompressionTypes |

This capability is a set of bit flags itemizing which (if any) non-standard general compression schemes are supported by this ASCE. Interpretation of this field depends on the negotiated generalCompressionLevel capability (see below) as follows:

  • • If the negotiated generalCompressionLevel capability is zero, then only the least significant bit flag of this field is valid (i.e., bit 0).
  • • If the negotiated generalCompressionLevel capability is greater than zero, then all bit flags within this field are valid.

See clause 8.3.2 for further information on non-standard general compression.

| F | Min | | | | | | | | | | | | | +| updateCapabilityFlag | This capability indicates whether this ASCE can receive the UpdateCapabilityPDU. A value of TRUE indicates that it can receive the UpdateCapabilityPDU and a value of FALSE indicates that it cannot. See clause 8.2.14 for further information. | L | One | | | | | | | | | | | | | +| remoteUnshareFlag | This capability indicates whether this ASCE can receive an ApplicationPDU with the UnhostApplication action. A value of TRUE indicates that it can receive an ApplicationPDU with the UnhostApplication action and a value of FALSE indicates that it cannot. See clause 8.9 for further information. | L | One | | | | | | | | | | | | | + +**Table 8-3 – General capability set (legacy mode)** + +| Capability | Description | Class | Rule | +|--------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|------| +| generalCompressionLevel | This capability indicates which level of general compression scheme handling is supported by this ASCE. See clause 8.3.2 for further information on non-standard general compression. | N | Min | + +**Table 8-4 – General capability set (base mode)** + +| Capability
(default value) | Description | ID | Class | Rule | +|------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----|-------|---------------| +| remoteUnshareFlag | This capability indicates whether this ASCE can receive an ApplicationPDU with the UnhostApplication action. See clause 8.9 for further information. This capability must be advertised using non-collapsing capabilities. | 1 | L | One | +| v42bisCompressionFlag | This capability indicates whether this ASCE can receive ASPDUs general compressed using V.42 bis compression. See clause 8.3.2 for further information. | 2 | L | Min | +| v42bisNumberCodeWords
(default: 512) | This capability specifies the total number of codewords to be used by the V.42 bis compression algorithm. This is an upper bound on V.42 bis parameter P1. [ITU-T V.42 bis ] does not impose an upper limit on its value. See clause 8.3.2 for further information. | 3 | N | Min
(Note) | +| v42bisMaxStringLength
(default: 6) | This capability specifies the maximum string length input to the V.42 bis encoder. This is an upper bound on V.42 bis parameter P2. See clause 8.3.2 for further information. | 4 | N | Min
(Note) | + +NOTE – The v42bisNumberCodeWords and v42bisMaxStringLength capabilities are dependent on the v42bisCompressionFlag capability. If the respective numberOfEntities parameter returned by the GCC-Application-Roster-Report indication for the v42bisNumberCodeWords or v42bisMaxStringLength capabilities is equal to the numberOfEntities parameter for the v42bisCompressionFlag capability, then the respective negotiated value is established; otherwise the default value of the capability is established. + +### 8.2.4 Bitmap capability set + +The bitmap capability set provides capabilities for the bitmap-oriented characteristics of the issuing ASCE. See Tables 8-5 and 8-6. + +**Table 8-5 – Bitmap capability set (legacy mode)** + +| Capability | Description | Class | Rule | +|------------------------------|----------------------------------------------------------------------------------------------------------|-------|-------------------| +| preferredBitsPerPixel | This capability indicates this ASCE's preferred format for bitmap data. Allowable values are 1, 4 and 8. | N | Group
(Note 1) | + +**Table 8-5 – Bitmap capability set (legacy mode)** + +| Capability | Description | Class | Rule | +|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|----------------| +| receive1BitPerPixelFlag | This capability indicates whether this ASCE can receive 1 bit-per-pixel bitmap data. An ASCE is required to be able to receive 1 bit-per-pixel bitmap and shall set this parameter to TRUE. | L | Group (Note 1) | +| receive4BitsPerPixelFlag | This capability indicates whether this ASCE can receive 4 bits-per-pixel bitmap data. A value of TRUE indicates that it can receive 4 bits-per-pixel bitmap data and a value of FALSE indicates that it cannot. Where an ASCE specifies that it can receive 4 bits-per-pixel, then it must also receive 1 bit-per-pixel. | L | Group (Note 1) | +| receive8BitsPerPixelFlag | This capability indicates whether this ASCE can receive 8 bits-per-pixel bitmap data. A value of TRUE indicates that it can receive 8 bits-per-pixel bitmap data and a value of FALSE indicates that it cannot. Where an ASCE specifies that it can receive 8 bits-per-pixel, then it must also receive 1 and 4 bits-per-pixel. | L | Group (Note 1) | +| desktopWidth | This capability specifies this ASCE's current desktop width in pixels. | N | Group (Note 2) | +| desktopHeight | This capability specifies this ASCE's current desktop height in pixels. | N | Group (Note 2) | +| desktopResizeFlag | This capability indicates whether this ASCE can receive UpdateCapabilityPDUs containing a bitmap capability set as a result of a peer ASCE desktop resize. A value of TRUE indicates that it can receive an UpdateCapabilityPDU containing a bitmap capability set and a value of FALSE indicates that it cannot. See clause 8.2.14 for further information. | L | One | +| bitmapCompressionFlag | This capability indicates whether this ASCE can receive compressed bitmap data in UpdatePDU (bitmap) and in cache bitmap orders. See clause 8.17 for further information on bitmap compression. | L | Min | +| NOTE 1 – The bits-per-pixel related capabilities are negotiated as a group to determine the sendingBitsPerPixel using the algorithm described in clause 8.2.4.1. | | | | +| NOTE 2 – The desktop width and desktop height capabilities are negotiated as a group to determine (among others) the size of the virtual desktop. See clause 8.2.4.2. | | | | + +**Table 8-6 – Bitmap capability set (base mode)** + +| Capability
(default value) | Description | ID | Class | Rule | +|----------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----|-------|----------------| +| preferredBitsPerPixel
(default: 8) | This capability indicates this ASCE's preferred format for bitmap data. Allowable values are 1, 4 and 8. This capability must be advertised using non-collapsing capabilities. | 10 | N | Group (Note 1) | + +**Table 8-6 – Bitmap capability set (base mode)** + +| Capability
(default value) | Description | ID | Class | Rule | +|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----|-------|-------------------| +| receive4BitsPerPixelFlag | This capability indicates whether this ASCE can receive 4 bits-per-pixel bitmap data. Where an ASCE specifies that it can receive 4 bits-per-pixel, then it must also be able to receive 1 bit-per-pixel. | 11 | L | Group
(Note 1) | +| receive8BitsPerPixelFlag | This capability indicates whether this ASCE can receive 8 bits-per-pixel bitmap data. Where an ASCE specifies that it can receive 8 bits-per-pixel, then it must also be able to receive 1 and 4 bits-per-pixel. | 12 | L | Group
(Note 1) | +| desktopWidth
(default: 640) | This capability specifies this ASCE's current desktop width in pixels. This capability must be advertised using non-collapsing capabilities. | 13 | N | Group
(Note 2) | +| desktopHeight
(default: 480) | This capability specifies this ASCE's current desktop height in pixels. This capability must be advertised using non-collapsing capabilities. | 14 | N | Group
(Note 2) | +| bitmapCompressionFlag | This capability indicates whether this ASCE can receive compressed bitmap data in UpdatePDU (bitmap) and in cache bitmap orders. See clause 8.17 for further information on bitmap compression. | 15 | L | Min | +| NOTE 1 – The bits-per-pixel related capabilities are negotiated as a group to determine the sendingBitsPerPixel using the algorithm described in clause 8.2.4.1. | | | | | +| NOTE 2 – The desktop width and desktop height capabilities are negotiated as a group to determine (among others) the size of the virtual desktop. See clause 8.2.4.2. | | | | | + +#### 8.2.4.1 Sending bits-per-pixel capabilities negotiation + +The bitmap capability set preferredBitsPerPixel, receive1BitPerPixelFlag (in legacy mode), receive4BitsPerPixelFlag and receive8BitsPerPixelFlag capabilities are negotiated as a group to determine the sendingBitsPerPixel used by each ASCE when sending bitmap data, palettes and ColorTables. + +Certain terminal types can acquire and render bitmap data in a range of colour depths, but may have a preferred colour depth (which normally corresponds to the actual terminal display colour depth) at which acquisition and rendering is either more efficient or can be achieved with better colour fidelity. Therefore, the bitmap capability set provides a range of capabilities, which enables an ASCE to express: + +- its preferred colour depth for the receipt of bitmap data, palettes and ColorTables; +- other colour depths at which it can receive bitmap data, palettes and ColorTables. + +The capabilities negotiation algorithm for this group determines a sendingBitsPerPixel for a particular ASCE using the advertised preferredBitsPerPixel, receive4BitsPerPixelFlag and receive8BitsPerPixelFlag capability values, as follows: + +- set combinedBitsPerPixel to the minimum of this ASCE's preferredBitsPerPixel value and the maximum of all other ASCEs' preferredBitsPerPixel values; +- if the combinedBitsPerPixel is 1 then set sendingBitsPerPixel to 1; + +- else if combinedBitsPerPixel is less than or equal to 4 and the negotiated receive4BitsPerPixelFlag value is TRUE then sendingBitsPerPixel is 4; +- else if the negotiated receive8BitsPerPixelFlag value is TRUE then sendingBitsPerPixel is 8; +- else if the negotiated receive4BitsPerPixelFlag value is TRUE then sendingBitsPerPixel is 4; +- else sendingBitsPerPixel is 1. + +In the legacy mode of the AS protocol, the bitmap capability set contains a receive1BitPerPixelFlag capability, but this does not play a part in the negotiation, as the requirement to support lower colour depths (i.e., an ASCE is required to support at least 1 bit-per-pixel if it supports 4 bits-per-pixel and to support 1 and 4 bits-per-pixel if it supports 8 bits-per-pixel) means that all ASCEs must support 1 bit-per-pixel. In the base mode of the AS protocol, the bitmap capability set does not contain a receive1BitPerPixelFlag capability. + +The requirement for an ASCE to support lower colour depths means that an ASCE conforming to this Recommendation shall not cause capabilities negotiation to fail to find a suitable value. + +An ASCE may use an alternate private algorithm in certain circumstances. For example, certain 8 bits-per-pixel terminals do not reliably generate 4 bits-per-pixel bitmap data. Where this is the case and the negotiated receive8BitsPerPixel value is TRUE, the ASCE may set sendingBitsPerPixel to 8, even where the combinedBitsPerPixel value is 4. However, where an ASCE does use a private algorithm, it shall still generate a sendingBitsPerPixel value which is consistent with the negotiated values of the receive4BitsPerPixelFlag and receive8BitsPerPixelFlag capabilities. + +#### **8.2.4.2 Desktop size capabilities negotiation** + +The bitmap capability set desktop width and desktop height capabilities are independently negotiated to determine the size of the virtual desktop. See clause 5.2.5 for further information on the virtual desktop. + +The capabilities negotiation algorithm essentially uses the max rule (see clause 8.2.2), but the candidate values are the capability values advertised by all active hosting ASCEs, which may or may not include the determining ASCE. + +For example, in a conference with four active ASCEs – ASCEs A, B, C and D where: + +- ASCE A advertises Bitmap.desktopWidth and Bitmap.desktopHeight as 800 and 600 respectively; +- ASCE B advertises Bitmap.desktopWidth and Bitmap.desktopHeight as 1024 and 768 respectively; +- ASCE C advertises Bitmap.desktopWidth and Bitmap.desktopHeight as 1600 and 1200 respectively; +- ASCE D advertises Bitmap.desktopWidth and Bitmap.desktopHeight as 640 and 480 respectively; +- then if ASCEs A and C are hosting, the negotiated virtual desktop capability values are 1600 by 1200; +- whereas if ASCEs B and D are hosting, the negotiated virtual desktop capability values are 1024 by 768. + +### **8.2.5 Order capability set** + +The order capability set provides capabilities for the order characteristics of the issuing ASCE. + +See Appendix I for informative values for the desktop save capabilities (i.e., desktopSaveXGranularity, desktopSaveYGranularity and desktopSaveSize). See Tables 8-7 and 8-8. + +**Table 8-7 – Order capability set (legacy mode)** + +| Capability | Description | Class | Rule | | | | | | | | | | | | | | | | | | | | | | | | | | | | +|--------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------|------------------|--|-------------------------|---|--------------------|---------------------|---|--------------------|--------------------|---|--------------------|--------------------|---|--------------------|------------------------------|---|---------------------|--------------|---|---------------------|-----------------------|---|---------------------|-------------------|---|---------------------|---|-----| +| terminalDescriptor | This capability is a null-terminated character T.50 text string which may be used to identify local terminal characteristics for information and diagnostics purposes. | S | Info | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| desktopSaveXGranularity | This capability specifies the minimum X granularity in pixels for this ASCE when receiving desktop save orders. See clause 8.16.17 for further information. | N | Max
(Note 1) | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| desktopSaveYGranularity | This capability specifies the minimum Y granularity in pixels for this ASCE when receiving desktop save orders. See clause 8.16.17 for further information. | N | Max
(Note 1) | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| maximumOrderLevel | This capability specifies the maximum order level supported within the orderSupport capability (see below). See clause 8.2.6 for further information on order levels. | N | Info | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| numberFonts | This capability is the maximum number of matchable fonts for this ASCE, details of which are subsequently supplied in the FontPDU. See clause 8.8 for further information on the FontPDU. | N | Info
(Note 2) | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| orderFlags |

This capability is a set of bit flags indicating the order support provided by this ASCE. Defined bit flag values are as follows.

  • • Negotiate order support: It is mandatory to set this flag.
  • • Cannot receive orders: If this flag is set, it indicates that this ASCE cannot receive orders.

An ASCE shall always set the negotiate order support flag. See clause 8.16.3 for further information on order encoding.

| F | Min
(Note 3) | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| orderSupport |

This capability is an array of 32 order levels indexed by order type. The allowable array indices are as follows. All other array values shall be set to zero. See below for further information on order levels.

Order Index
Destination Blt support 0 See clause 8.16.4.
Pattern Blt support 1 See clause 8.16.5.
Screen Blt support 2 See clause 8.16.6.
Memory Blt support 3 See clause 8.16.9.
Memory three-way Blt support 4 See clause 8.16.10.
Text support 5 See clause 8.16.11.
Extended text support 6 See clause 8.16.12.
Rectangle support 7 See clause 8.16.14.
| Order | Index | | Destination Blt support | 0 | See clause 8.16.4. | Pattern Blt support | 1 | See clause 8.16.5. | Screen Blt support | 2 | See clause 8.16.6. | Memory Blt support | 3 | See clause 8.16.9. | Memory three-way Blt support | 4 | See clause 8.16.10. | Text support | 5 | See clause 8.16.11. | Extended text support | 6 | See clause 8.16.12. | Rectangle support | 7 | See clause 8.16.14. | N | Min | +| Order | Index | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| Destination Blt support | 0 | See clause 8.16.4. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| Pattern Blt support | 1 | See clause 8.16.5. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| Screen Blt support | 2 | See clause 8.16.6. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| Memory Blt support | 3 | See clause 8.16.9. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| Memory three-way Blt support | 4 | See clause 8.16.10. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| Text support | 5 | See clause 8.16.11. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| Extended text support | 6 | See clause 8.16.12. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| Rectangle support | 7 | See clause 8.16.14. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | + +**Table 8-7 – Order capability set (legacy mode)** + +| Capability | Description | Class | Rule | +|------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|--------------| +| |
Line support 8 See clause 8.16.16.
Frame support 9 See clause 8.16.13.
Opaque rectangle support 10 See clause 8.16.15.
Desktop save support 11 See clause 8.16.17.
| | | +| textFlags |

This capability is a set of bit flags indicating font matching and text options supported by this ASCE. Defined bit flag values are as follows:

  • • Check font aspect If this flag is set, it indicates that this ASCE supports the checking of font horizontal and vertical aspects during font matching.
  • • Check font signatures If this flag is set, it indicates that this ASCE supports the checking of font signatures during font matching.
  • • DeltaX simulation If this flag is set, it indicates that this ASCE allows Delta X approximations during font matching.
  • • Baseline start If this flag is set, it indicates that this ASCE can receive text and extended text orders where the text start position is specified with respect to the character baseline.

See clause 8.8 for further information on font matching. See clause 8.16.11 and clause 8.16.12 for further information on text and extended text orders.

| F | Min | +| desktopSaveSize | This capability specifies the total size in pixels of this ASCE's desktop cache per hosting ASCE. See clause 8.16.17 for further information. | N | Min (Note 1) | + +NOTE 1 – As a result of capabilities negotiation, an ASCE must be able to receive desktop save orders constructed using X and/or Y granularities larger than, or not exact multiples of, its advertised desktopSaveXGranularity and desktopSaveYGranularity capabilities. Similarly, an ASCE must be able to send desktop save orders where the negotiated desktopSaveSize is not an exact multiple of its advertised desktopSaveXGranularity and desktopSaveYGranularity capabilities. + +NOTE 2 – A receiving ASCE may use the numberFonts capability to determine whether it has sufficient storage to receive this ASCE's fonts on subsequent FontPDUs. The numberFonts capability is an upper limit and subsequent FontPDUs may contain a number of font attributes less than or equal to the numberFonts capability. See clause 8.8 for further information on the FontPDU. + +NOTE 3 – It is mandatory that the negotiate order support bit flag is set. The cannot receive orders bit flag allows an ASCE to advertise whether it can or cannot receive orders. Where the cannot receive orders bit flag is not set, it indicates that the ASCE can receive orders. Where the cannot receive orders bit flag is set, it indicates that the ASCE cannot receive orders, which forces peer ASCEs to disable the sending of order updates entirely and to just send bitmap updates. + +**Table 8-8 – Order capability set (base mode)** + +| Capability
(default value) | Description | ID | Class | Rule | +|------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------|--------------|---------------| +| desktopSaveXGranularity
(default: 1) | This capability specifies the minimum X granularity in pixels for this ASCE when receiving desktop save orders. See clause 8.16.17 for further information. | 20 | N | Max
(Note) | +| desktopSaveYGranularity
(default: 1) | This capability specifies the minimum Y granularity in pixels for this ASCE when receiving desktop save orders. See clause 8.16.17 for further information. | 21 | N | Max
(Note) | +| desktopSaveSize
(default: 160,000) | This capability specifies the total size in pixels of this ASCE's desktop cache. See clause 8.16.17 for further information. | 22 | N | Min
(Note) | +| checkFontAspectFlag | This capability indicates whether this ASCE supports the checking of font horizontal and vertical aspects during font matching. See clause 8.8 for further information on font matching. | 23 | L | Min | +| checkFontSignaturesFlag | This capability indicates whether this ASCE supports the checking of font signatures during font matching. See clause 8.8 for further information on font matching. | 24 | L | Min | +| allowDeltaXFlag | This capability indicates whether this ASCE allows delta X approximations during font matching. See clause 8.8 for further information on font matching. | 25 | L | Min | +| baselineStartFlag | This capability indicates whether this ASCE can receive text and extended text orders where the text start position is specified with respect to the character baseline. See clause 8.16.11 and clause 8.16.12 for further information on text and extended text orders. | 26 | L | Min | +| receiveOrdersFlag | This capability indicates whether this ASCE can receive UpdatePDU (orders) ASPDUs – i.e., whether it can receive orders or not. See clause 8.16 for further information on orders. | 27 | L | Min | +| DesktopSaveLevel
(default: 1) | This capability indicates the desktop save order level supported by this ASCE. See clause 8.16.17 for further information on the desktop save order. | 30 | N | Min | +| DestinationBltLevel
(default: 1) | This capability specifies the destination Blt order level supported by this ASCE. See clause 8.2.6 for further information on order levels and 8.16.4 for further information on the destination Blt order. | 31 | N | Min | + +**Table 8-8 – Order capability set (base mode)** + +| Capability
(default value) | Description | ID | Class | Rule | +|-----------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------|--------------|-------------| +| ExtendedTextLevel
(default: 1) | This capability specifies the extended text order level supported by this ASCE. See clause 8.2.6 for further information on order levels and clause 8.16.12 for further information on the extended text order. | 32 | N | Min | +| FrameLevel
(default: 1) | This capability specifies the frame order level supported by this ASCE. See clause 8.2.6 for further information on order levels and clause 8.16.13 for further information on the frame order. | 33 | N | Min | +| LineLevel
(default: 1) | This capability specifies the line order level supported by this ASCE. See clause 8.2.6 for further information on order levels and clause 8.16.16 for further information on the line order. | 34 | N | Min | +| MemoryBltLevel
(default: 1) | This capability specifies the memory Blt order level supported by this ASCE. See clause 8.2.6 for further information on order levels and clause 8.16.9 for further information on the memory Blt order. | 35 | N | Min | +| MemoryThreeWayBltLevel
(default: 1) | This capability specifies the memory three-way Blt order level supported by this ASCE. See clause 8.2.6 for further information on order levels and clause 8.16.10 for further information on the memory three-way Blt order. | 36 | N | Min | +| OpaqueRectangleLevel
(default: 1) | This capability specifies the opaque rectangle order level supported by this ASCE. See clause 8.2.6 for further information on order levels and clause 8.16.15 for further information on the opaque rectangle order. | 37 | N | Min | +| PatternBltLevel
(default: 1) | This capability specifies the pattern Blt order level supported by this ASCE. See clause 8.2.6 for further information on order levels and clause 8.16.5 for further information on the pattern Blt order. | 38 | N | Min | +| RectangleLevel
(default: 1) | This capability specifies the rectangle order level supported by this ASCE. See clause 8.2.6 for further information on order levels and clause 8.16.14 for further information on the rectangle order. | 39 | N | Min | +| ScreenBltLevel
(default: 1) | This capability specifies the screen Blt order level supported by this ASCE. See clause 8.2.6 for further information on order levels and clause 8.16.6 for further information on the screen Blt order. | 40 | N | Min | + +**Table 8-8 – Order capability set (base mode)** + +| Capability
(default value) | Description | ID | Class | Rule | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------|--------------|-------------| +| TextLevel
(default: 1) | This capability specifies the text order level supported by this ASCE. See clause 8.2.6 for further information on order levels and clause 8.16.11 for further information on the text order. | 41 | N | Min | +| DesktopOriginLevel
(default: 1) | This capability specifies the desktop origin order level supported by this ASCE. See clause 8.2.6 for further information on order levels and clause 8.16.18 for further information on the desktop origin order. | 42 | N | Min | +| CacheBitmapLevel
(default: 1) | This capability specifies the cache bitmap order level supported by this ASCE. See clause 8.2.6 for further information on order levels and clause 8.16.7 for further information on the cache bitmap order. | 43 | N | Min | +| CacheColorTableLevel
(default: 1) | This capability specifies the cache ColorTable order level supported by this ASCE. See clause 8.2.6 for further information on order levels and clause 8.16.8 for further information on the cache ColorTable order. | 44 | N | Min | +| ColorSpaceLevel
(default: 1) | This capability specifies the colour space order level supported by this ASCE. See clause 8.2.6 for further information on order levels and clause 8.16.19 for further information on the colour space order. | 45 | N | Min | +| NOTE – As a result of capabilities negotiation, an ASCE must be able to receive desktop save orders constructed using X and/or Y granularities larger than, or not exact multiples of, its advertised desktopSaveXGranularity and desktopSaveYGranularity capabilities. Similarly, an ASCE must be able to send desktop save orders where the negotiated desktopSaveSize is not an exact multiple of its advertised desktopSaveXGranularity and desktopSaveYGranularity capabilities. | | | | | + +### 8.2.6 Order levels + +The AS protocol allows for future enhancement of order support using order levels. Order level values are in the range 0..255, with the value 0 indicating that the indicated order is not supported. + +The order level values in the Order.orderSupport capability (for the legacy mode of the AS protocol) and in the per-order level capability parameters (for the base mode of the AS protocol) indicate the maximum order level that the issuing ASCE can receive on an order-by-order basis. If an ASCE indicates that it can receive order level N for a particular order, then it shall be able to receive order levels in the range 1..N. It is envisaged that as additional application sharing requirements emerge (e.g., reflecting changing order usage in target terminals), then existing AS orders may be enhanced. Where that is the case, an ASCE may advertise support for a range of enhanced orders and, where it is in a conference with a group of active ASCEs that also support the enhanced orders, may use them when constructing UpdatePDU (orders) ASPDUs. In summary, this means that: + +- where an ASCE supports an order at order level N, it shall be prepared to receive orders at order levels 1..N; + +- where an ASCE supports an order at order level N and the negotiated order level is greater than or equal to N, then the ASCE may send the order at order levels 1..N; +- where an ASCE supports an order at order level N and the negotiated order level is less than N, then the ASCE may send the order at order levels 1 through the negotiated value – but may not send orders at order levels greater than the negotiated value. + +For the legacy mode of the AS protocol, order level support is not defined for the desktop origin, cache bitmap and cache ColorTable orders (see clauses 8.16.18, 8.16.7 and 8.16.8, respectively). In the absence of order level support for these orders: + +- if an ASCE supports the screen Blt order at order level 1 or above, it shall also support the desktop origin order; +- if an ASCE supports either of the memory Blt and memory three-way Blt orders at order level 1 or above, it shall also support the cache bitmap and cache ColorTable orders and shall ensure that it advertises valid values for the bitmap cache and ColorTable cache capability sets (see clauses 8.2.7 and 8.2.8 for further information on the bitmap cache and ColorTable cache capability sets). + +### 8.2.7 Bitmap cache capability set + +The bitmap cache capability set provides capabilities for the bitmap cache characteristics of the issuing ASCE. These capabilities are used to negotiate values used to construct cache bitmap orders in UpdatePDUs. See clause 8.16.7 for further information on cache bitmap orders. + +If an ASCE supports either of the memory Blt and memory three-way Blt orders at order level 1 or above, it shall support the cache bitmap order (in base mode at order level 1 or above) and ensure that it advertises bitmap cache capability set values with: + +- non-zero values for the cache1Entries, cache2Entries and cache3Entries capabilities; +- allowable values for the cache1MaximumCellSize, cache2MaximumCellSize and cache3MaximumCellSize capabilities (as specified in Tables 8-9 and 8-10); +- $\text{cache3MaximumCellSize} \geq \text{cache2MaximumCellSize} \geq \text{cache1MaximumCellSize}$ . + +Where an ASCE supports bitmap caching, these capabilities indicate the bitmap cache sizes per each other hosting ASCE. That is, by advertising these capabilities, the ASCE is committing to provide a set of bitmap caches of the advertised sizes for each other active ASCE in the conference that is hosting windows. + +See Appendix I for informative values for bitmap cache capabilities. + +**Table 8-9 – Bitmap cache capability set (legacy mode)** + +| Capability | Description | Class | Rule | +|------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------|-------|------| +| cache1Entries | This capability is the number of cache entries in the first cache area. | N | Min | +| cache1MaximumCellSize | This capability is the maximum cell size in octets for the first cache area. The value for this capability is in the range 256..16384. | N | Min | +| cache2Entries | This capability is the number of cache entries in the second cache area. | N | Min | +| cache2MaximumCellSize | This capability is the maximum cell size in octets for the second cache area. The value for this capability is in the range 256..16384. | N | Min | +| cache3Entries | This capability is the number of cache entries in the third cache area. | N | Min | + +**Table 8-9 – Bitmap cache capability set (legacy mode)** + +| Capability | Description | Class | Rule | +|------------------------------|----------------------------------------------------------------------------------------------------------------------------------------|-------|------| +| cache3MaximumCellSize | This capability is the maximum cell size in octets for the third cache area. The value for this capability is in the range 256..16384. | N | Min | + +**Table 8-10 – Bitmap cache capability set (base mode)** + +| Capability
(default value) | Description | ID | Class | Rule | +|-------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------|----|-------|------| +| cache1Entries
(default: 600) | This capability is the number of cache entries in the first cache area. | 80 | N | Min | +| cache1MaximumCellSize
(default: 496) | This capability is the maximum cell size in octets for the first cache area. The value for this capability is in the range 256..16384. | 81 | N | Min | +| cache2Entries
(default: 300) | This capability is the number of cache entries in the second cache area. | 82 | N | Min | +| cache2MaximumCellSize
(default: 2032) | This capability is the maximum cell size in octets for the second cache area. The value for this capability is in the range 256..16384. | 83 | N | Min | +| cache3Entries
(default: 150) | This capability is the number of cache entries in the third cache area. | 84 | N | Min | +| cache3MaximumCellSize
(default: 4080) | This capability is the maximum cell size in octets for the third cache area. The value for this capability is in the range 256..16384. | 85 | N | Min | + +### 8.2.8 ColorTable cache capability set + +The ColorTable cache capability set provides capabilities for the ColorTable cache characteristics of the issuing ASCE. These capabilities are used to negotiate values used to construct cache ColorTable orders in UpdatePDUs. See clause 8.16.8 for further information on cache ColorTable orders and also Tables 8-11 and 8-12. + +If an ASCE supports either of the memory Blt and memory three-way Blt orders at order level 1 or above, it shall support the cache ColorTable order (in base mode at order level 1 or above) and ensure that it advertises a ColorTable cache capability set containing a non-zero value for the colorTableCacheSize capability. + +Where an ASCE supports ColorTable caching, these capabilities indicate the ColorTable cache size per each other hosting ASCE. That is, by advertising these capabilities, the ASCE is committing to provide a ColorTable cache of the advertised size for each other active ASCE in the conference that is hosting windows. + +See Appendix I for informative values for ColorTable cache capability set values. + +**Table 8-11 – ColorTable cache capability set (legacy mode)** + +| Capability | Description | Class | Rule | +|----------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|------| +| colorTableCacheSize | This capability specifies the number of ColorTable entries in this ASCE's receiving ColorTable cache. Where an ASCE supports ColorTable caching, the allowable values are in the range 1..255 (zero is not allowed). See clause 8.16.8 for further information on ColorTable caching. | N | Min | + +**Table 8-12 – ColorTable cache capability set (base mode)** + +| Capability
(default value) | Description | ID | Class | Rule | +|--------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----|-------|------| +| colorTableCacheSize
(default: 6) | This capability specifies the number of ColorTable entries in this ASCE's receiving ColorTable cache. Where an ASCE supports ColorTable caching, the allowable values are in the range 1..255 (zero is not allowed). See clause 8.16.8 for further information on ColorTable caching. | 90 | N | Min | + +### 8.2.9 Window activation capability set + +The window activation capability set provides capabilities for the window activation characteristics of the issuing ASCE, and in particular about its support for specific WindowActivationPDU activation messages. See clause 8.11 for further information on WindowActivationPDUs and also Tables 8-13 and 8-14. + +**Table 8-13 – Window activation capability set (legacy mode)** + +| Capability | Description | Class | Rule | +|----------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|------| +| helpKeyFlag | This capability indicates whether this ASCE can receive WindowActivationPDUs containing the ActivationHelpKey action. A value of TRUE indicates that it can receive WindowActivationPDUs containing the ActivationHelpKey action and a value of FALSE indicates that it cannot. See clause 8.11 for further information. | L | One | +| helpIndexKeyFlag | This capability indicates whether this ASCE can receive WindowActivationPDUs containing the ActivationHelpIndexKey action. A value of TRUE indicates that it can receive WindowActivationPDUs containing the ActivationHelpIndexKey action and a value of FALSE indicates that it cannot. See clause 8.11 for further information. | L | One | +| helpExtendedKeyFlag | This capability indicates whether this ASCE can receive WindowActivationPDUs containing the ActivationHelpExtendedKey action. A value of TRUE indicates that it can receive WindowActivationPDUs containing the ActivationHelpExtendedKey action and a value of FALSE indicates that it cannot. See clause 8.11 for further information. | L | One | + +**Table 8-13 – Window activation capability set (legacy mode)** + +| Capability | Description | Class | Rule | +|------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|------| +| windowManagerMenuFlag | This capability indicates whether this ASCE can receive WindowActivationPDUs containing the WindowManagerMenu action. A value of TRUE indicates that it can receive WindowActivationPDUs containing the WindowManagerMenu action and a value of FALSE indicates that it cannot. See clause 8.11 for further information. | L | One | + +**Table 8-14 – Window activation capability set (base mode)** + +| Capability
(default value) | Description | ID | Class | Rule | +|-------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----|-------|------| +| helpKeyFlag | This capability indicates whether this ASCE can receive WindowActivationPDUs containing the ActivationHelpKey action. See clause 8.11 for further information. This capability must be advertised using non-collapsing capabilities. | 100 | L | One | +| helpIndexKeyFlag | This capability indicates whether this ASCE can receive WindowActivationPDUs containing the ActivationHelpIndexKey action. See clause 8.11 for further information. This capability must be advertised using non-collapsing capabilities. | 101 | L | One | +| helpExtendedKeyFlag | This capability indicates whether this ASCE can receive WindowActivationPDUs containing the ActivationHelpExtendedKey action. See clause 8.11 for further information. This capability must be advertised using non-collapsing capabilities. | 102 | L | One | +| windowManagerMenuFlag | This capability indicates whether this ASCE can receive WindowActivationPDUs containing the WindowManagerMenu action. See clause 8.11 for further information. This capability must be advertised using non-collapsing capabilities. | 103 | L | One | + +### 8.2.10 Control capability set + +The control capability set provides capabilities for the control characteristics of the issuing ASCE. These capabilities are used to negotiate values used in the management of control and detached status between ASCEs. See clause 8.12 for further information on control characteristics and also Tables 8-15 and 8-16. + +**Table 8-15 – Control capability set (legacy mode)** + +| Capability | Description | Class | Rule | +|--------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|------------| +| controlFlags |

This capability is a set of bit flags indicating the control options supported by this ASCE. Defined bit flag values are as follows:

  • Allow mediated control

If an ASCE does not set the allow mediated control bit flag capability, the ASCE does not support the AS mediated control protocol. Where this is the case, the remoteDetachFlag, controlInterest and detachInterest capabilities need not be negotiated and the MediatedControlPDU is not valid. See clause 8.13 for further information.

| F | Min | +| remoteDetachFlag |

This capability indicates whether this ASCE allows other ASCEs to force it into detached control mode. A value of TRUE indicates that this ASCE allows other ASCEs to force it into detached control mode and a value of FALSE indicates that it does not. See clause 8.13 for further information.

| L | One | +| controlInterest |

This capability indicates this ASCE's behaviour for changes of control. Allowable values are as follows:

  • Always This ASCE always permits changes of control.
  • Confirm This ASCE requires to confirm changes of control.
  • Never This ASCE never allows changes of control.

See clause 8.13 for further information.

| N | Max (Note) | +| detachInterest |

This capability indicates this ASCE's behaviour for changes in detach status. Allowable values are as follows:

  • Always This ASCE always permits changes in detach status.
  • Confirm This ASCE requires to confirm changes in detach status.
  • Never This ASCE never allows changes in detach status.

See clause 8.13 for further information.

| N | Max (Note) | +| NOTE – The controlInterest and detachInterest capabilities are negotiated using values such that never is greater than confirm which is greater than always. | | | | + +**Table 8-16 – Control capability set (base mode)** + +| Capability
(default value) | Description | ID | Class | Rule | +|-------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----|-------|------| +| mediatedControlFlag |

This capability indicates whether the issuing ASCE supports the mediated control protocol. Where this capability is not supported, the remoteDetachFlag, controlInterest and detachInterest capabilities need not be negotiated and the MediatedControlPDU is not valid. See clause 8.13 for further information.

| 110 | L | Min | + +**Table 8-16 – Control capability set (base mode)** + +| Capability
(default value) | Description | ID | Class | Rule | +|--------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----|-------|---------------| +| remoteDetachFlag | This capability indicates whether this ASCE allows other ASCEs to force it into detached control mode. See clause 8.13 for further information. This capability must be advertised using non-collapsing capabilities. | 111 | L | One | +| controlInterest
(default: always) |

This capability indicates this ASCE's behaviour for changes of control. Allowable values are as follows.

  • • Always This ASCE always permits changes of control.
  • • Confirm This ASCE requires to confirm changes of control.
  • • Never This ASCE never allows changes of control.

See clause 8.13 for further information. This capability must be advertised using non-collapsing capabilities.

| 112 | N | Max
(Note) | +| detachInterest
(default: always) |

This capability indicates this ASCE's behaviour for changes in detach status. Allowable values are as follows:

  • • Always This ASCE always permits changes in detach status.
  • • Confirm This ASCE requires to confirm changes in detach status.
  • • Never This ASCE never allows changes in detach status.

See clause 8.13 for further information. This capability must be advertised using non-collapsing capabilities.

| 113 | N | Max
(Note) | +| NOTE – The controlInterest and detachInterest capabilities are negotiated using values such that never is greater than confirm which is greater than always. | | | | | + +### 8.2.11 Pointer capability set + +The pointer capability set provides capabilities for the pointer characteristics of the issuing ASCE. These capabilities are used to negotiate values used to construct PointerPDUs. See clause 8.14 for further information on pointers and also Tables 8-17 and 8-18. + +Where an ASCE does not support colour pointers, or where it supports colour pointers but does not wish to support colour pointer caching, then it should advertise its Pointer.colorPointerCacheSize as one. This shall be interpreted as indicating that the advertising ASCE can only remember the last monochrome and/or colour pointer (depending on the negotiated value of the Pointer.colorPointerFlag) – that is, it does not support pointer caching. + +Where an ASCE supports colour pointers and colour pointer caching, these capabilities indicate the colour pointer cache size per each other hosting ASCE. That is, by advertising these capabilities, the ASCE is committing to provide a colour pointer cache of the advertised size for each other active ASCE in the conference that is hosting windows. + +See Appendix I for informative values for pointer capabilities. + +**Table 8-17 – Pointer capability set (legacy mode)** + +| Capability | Description | Class | Rule | +|------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|------| +| colorPointerFlag | This capability indicates whether this ASCE supports colour pointers. A value of TRUE indicates that this ASCE supports colour pointers and a value of FALSE indicates that it does not. See clause 8.14 for further information. | L | Min | +| colorPointerCacheSize | This capability specifies the number of entries in this ASCE's receiving colour pointer cache. The allowable values are in the range 1..500. Where an ASCE does not support colour pointers, it shall set this capability to 1 (a value of zero is not allowed). See clause 8.14 for further information on pointer caching. | N | Min | + +**Table 8-18 – Pointer capability set (base mode)** + +| Capability
(default value) | Description | ID | Class | Rule | +|-----------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----|-------|------| +| colorPointerFlag | This capability indicates whether this ASCE supports colour pointers. See clause 8.14 for further information. | 120 | L | Min | +| colorPointerCacheSize
(default: 25) | This capability specifies the number of entries in this ASCE's receiving colour pointer cache. The allowable values are in the range 1..500. Where an ASCE does not support colour pointers, it shall set this capability to 1 (a value of zero is not allowed). See clause 8.14 for further information on pointer caching. | 121 | N | Min | + +### 8.2.12 Share capability set + +The share capability set provides information about the node on which the ASCE executes. This capability set is only supported in the legacy mode of the AS protocol. + +The GCC node ID may be used by receiving ASCEs to correlate issuing ASCEs with their application records in the GCC application roster. See Table 8-19. + +**Table 8-19 – Share capability set (legacy mode)** + +| Capability | Description | Class | Rule | +|---------------|--------------------------------------------------------------------|-------|------| +| nodeID | This capability is the GCC node ID of the advertising ASCE's node. | N | Info | + +### 8.2.13 Non-standard capability set + +The non-standard capability set is used to negotiate non-standard functions. Any number of non-standard capabilities may appear in the non-standard capability set as long as they each have a unique Non-Standard-Identifier. Interpretation of these capabilities is not covered by this Recommendation. + +The non-standard capability set is only supported in the base mode of the AS protocol. There is no mechanism in the legacy mode of the AS protocol for the negotiation of non-standard capabilities. See Table 8-20. + +**Table 8-20 – Non-standard capability set (base mode)** + +| Capability | Description | ID | Class | Rule | +|------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------|-------|------| +| nonStandardCapability | This capability is used to negotiate non-standard functions. Any number of these may appear in the ASCE base mode capabilities as long as they each have a unique Non-Standard-Identifier. The interpretation of these capabilities is not covered by this Recommendation. | Non-standard identifier | – | – | + +### 8.2.14 Capability update + +For the base mode of the AS protocol, where an ASCE's capabilities change while enrolled, it shall re-enrol by issuing a GCC-Application-Enroll request to enrol in the standard base session with the enroll/unenroll flag set to enroll, including the revised combined capabilities. See clause 7 for further information on session enrolment and clause 8.2.1 for further information on the distribution of capabilities. + +For the legacy mode of the AS protocol, an ASCE may advertise changes in a capability set by sending an UpdateCapabilityPDU to other ASCEs within the conference in the manner indicated in Table 6-3. The content of the UpdateCapabilityPDU is shown in Table 8-21. + +An ASCE shall only send the UpdateCapabilityPDU where both the negotiated General.updateCapabilityFlag and Bitmap.desktopResizeFlag capabilities are TRUE. + +The only allowable capability set that can be advertised in an UpdateCapabilityPDU is the legacy mode bitmap capability set (see clause 8.2.4). + +**Table 8-21 – UpdateCapabilityPDU** + +| Parameter | Description | +|----------------------------|-------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| updateCapabilitySet | This parameter shall be a bitmap capability set. See clause 8.2.4 for a description of the bitmap capability set. | + +When an ASCE determines that one or more capabilities have been updated, it shall perform any required capabilities negotiation (see clause 8.2.2) and shall perform hosting synchronization (if it is hosting) and shadow synchronization (see clause 8.6). + +## 8.3 ASPDU formats + +In the legacy mode of the AS protocol, all ASPDUs, other than the following flow control ASPDUs, contain a ShareControl header. Table 8-22 describes the ShareControl header for the legacy mode of the AS protocol. In the base mode of the AS protocol, ASPDUs do not contain ShareControl headers. + +- FlowTestPDU: See clause 8.5. +- FlowResponsePDU: See clause 8.5. +- FlowStopPDU: See clause 8.5. + +**Table 8-22 – ShareControl header (legacy mode)** + +| Parameter | Description | +|------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| totalLength | This is the total length in octets of the ASPDU within which this header is included. This parameter is required as MCS implementations may segment ASPDUs in transmission and are not required to reassemble on delivery. This parameter allows receiving ASCEs to efficiently perform reassembly where MCS segmentation is present. | +| protocolVersion | This parameter identifies the protocol version supported by the issuing ASCE. The allowable value is 1. | +| PDUSource | This parameter is the MCS user ID of the ASCE sending the ASPDU containing this ShareControl header. | + +All ASPDUs, other than the following ASCE activation and flow control ASPDUs, contain a ShareData header and are referred to as data ASPDUs. + +- DemandActivePDU: See clause 8.4.1. +- ConfirmActivePDU: See clause 8.4.1. +- RequestActivePDU: See clause 8.4.1. +- DeactivateOtherPDU: See clause 8.4.1. +- DeactivateSelfPDU: See clause 8.4.1. +- DeactivateAllPDU: See clause 8.4.1. +- FlowTestPDU: See clause 8.5. +- FlowResponsePDU: See clause 8.5. +- FlowStopPDU: See clause 8.5. + +Tables 8-23 and 8-24 describe the ShareData header for the legacy and base modes of the AS protocol. + +**Table 8-23 – ShareData header (legacy mode)** + +| Parameter | Description | +|----------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareControl header | The ShareControl header is described in clause 8.3. | +| shareID | This parameter uniquely identifies the ASCE session within which this ASPDU is issued. See clause 8.4.2 for a description of share identifiers. | +| streamID | This parameter identifies the stream for this ASPDU. See clause 8.3.1 for a description of streams. | +| uncompressedLength | This parameter is the length of the uncompressed ASPDU data in octets, starting from and including the generalCompressedType parameter. This parameter may be used as a check on decompression. See clause 8.3.2 for further information on non-standard general compression. | + +**Table 8-23 – ShareData header (legacy mode)** + +| Parameter | Description | +|--------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| generalCompressedType |

This parameter indicates whether the issuing ASCE has general compressed the ASPDU containing this ShareData header – and if so, indicates which general compression scheme type has been applied. Interpretation of this field depends on the negotiated General.generalCompressionLevel capability as follows:

  • • If the negotiated General.generalCompressionLevel capability is zero, then the ASCE shall only reference the most significant bit of this field.
  • • If the negotiated General.generalCompressionLevel capability is greater than zero, then the ASCE shall reference all bits within this field.

A value of zero indicates that no general compression has been applied. A non-zero value specifies the particular compression type that has been applied. See clause 8.3.2 for further information on general compression.

| +| generalCompressedLength |

Where the generalCompressedType is non-zero, this parameter is the length of the compressed ASPDU data in octets, starting from after the uncompressedLength parameter. Where the generalCompressedType is zero, indicating that no general compression has been applied, this parameter shall be zero. See clause 8.3.2 for further information on general compression.

| + +**Table 8-24 – ShareData header (base mode)** + +| Parameter | Description | +|------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| shareID |

This parameter is the roster instance of the ASCE session within which this ASPDU is issued. See clause 8.4.2 for a description of share identifiers.

| +| generalCompressionSpecifier |

This optional parameter identifies the general compression scheme and any associated parameters applicable to this ASPDU. See clause 8.3.2 for further information.

| + +### 8.3.1 Streams + +In the legacy mode of the AS protocol, an ASCE is required to send data ASPDUs over a set of logical streams. Streams are used to represent ASCE data priorities and map onto MCS priorities as described in Table 8-25. Stream identifiers are present in all legacy mode data ASPDUs. Streams are not supported in the base mode of the AS protocol. + +**Table 8-25 – Stream identifiers (legacy mode)** + +| Stream ID | MCS priority | +|-----------|--------------| +| 4 | High | +| 2 | Medium | +| 1 | Low | + +### 8.3.2 General compression + +This Recommendation specifies compression schemes that may be applied to orders (which is termed order encoding – see clause 8.16.3) and bitmap data (which is termed bitmap compression – see clause 8.17) in UpdatePDUs. Both these compression schemes deliver good compression ratios on typical AS output data for relatively low processor loads. + +However, where an ASCE experiences flow control back pressure (see clause 8.5) – for example, when sending over slower links such as typical PSTN lines, or when sending over congested higher speed links – experience shows that significant performance enhancements may be achieved by the application of a dictionary-based compression scheme to selected ASPDUs – including already compressed data in UpdatePDU (orders) and UpdatePDU (bitmap) ASPDUs. This approach is termed general compression. + +#### 8.3.2.1 Legacy mode general compression + +This Recommendation does not specify a general compression mechanism for legacy mode, but rather provides a compression scheme-independent mechanism whereby ASCEs can negotiate and use mutually agreed general compression schemes, as follows. + +An ASCE shall negotiate the general compression scheme using the General.generalCompressionLevel and General.generalCompressionTypes capabilities. See clause 8.2.3 for further information on the general capability set. The GeneralCompressionLevel capability indicates which level of general compression is supported by an ASCE while the General.generalCompressionTypes capability is a set of bit flags, allowing an ASCE to indicate that it supports none, one or a selection of general compression schemes. + +Note that the interpretation of the General.generalCompressedTypes capability is dependent on the negotiated General.generalCompressionLevel capability. Where the negotiated General.generalCompressionLevel capability is zero, then only the least significant bit flag of the General.generalCompressedTypes capability shall be considered. Where the negotiated generalCompressionLevel capability is greater than zero, then all bit flags within the General.generalCompressedTypes capability shall be considered. + +Where an ASCE determines that other peer ASCEs can receive a particular general compression scheme, it may apply general compression to data ASPDUs on a selective basis – that is, an ASCE may apply general compression to none, some or all ASPDUs. The criteria by which an ASCE determines whether general compression is appropriate for a particular data ASPDU may include flow control status (see clause 8.5) and the size of the particular ASPDU. This Recommendation does not recommend a particular approach to the application of general compression – it is entirely a local matter for each ASCE. + +Where an ASCE does not apply general compression to a data ASPDU, either because no suitable general compression scheme is available after capabilities negotiation, or where a suitable general compression scheme has been negotiated but the sending ASCE determines that general compression is inappropriate, the ASCE shall set the generalCompressedType to zero to indicate that the ASPDU is not general compressed, the uncompressedLength parameter to the ASPDU octet length and the generalCompressedLength parameter to zero. Where an ASCE applies general compression to a data ASPDU, it shall set the generalCompressedType to a value corresponding to one of the negotiated general compression schemes to indicate that the ASPDU is general compressed, the uncompressedLength parameter to the ASPDU octet length before compression and the generalCompressedLength parameter to the ASPDU octet length after compression. Setting both the uncompressedLength and generalCompressedLength parameters allows a receiving ASCE to check that the ASPDU length after decompression is consistent with its original uncompressed length. + +Note that the interpretation of the `generalCompressedType` parameter in the `ShareData` header is dependent on the negotiated `General.generalCompressionLevel` capability. Where the negotiated `General.generalCompressionLevel` capability is zero, then only the most significant bit of the `General.generalCompressedType` parameter shall be considered. Where the negotiated `General.generalCompressionLevel` capability is greater than zero, then all bits of the `General.generalCompressedType` parameter shall be considered. + +See Appendix I for informative values and information on legacy mode general compression. + +#### 8.3.2.2 Base mode general compression + +This Recommendation specifies the optional use of [ITU-T V.42 *bis*] for general compression in base mode. + +Where an ASCE determines that other peer ASCEs can receive ASPDUs general compressed using V.24 *bis*, it may apply V.42 *bis* general compression to data ASPDUs on a selective basis – that is, an ASCE may apply V.42 *bis* general compression to none, some or all ASPDUs. The criteria by which an ASCE determines whether V.42 *bis* general compression is appropriate for a particular data ASPDU may include flow control status (see clause 8.5) and the size of the particular ASPDU. This Recommendation does not recommend a particular approach to the application of V.42 *bis* general compression – it is entirely a local matter for each ASCE. + +Where V.42 *bis* general compression is applied, the encoder is initialized during the sender's hosting synchronization and the decoder is initialized during the receivers' shadow synchronization (see clauses 8.6.2 and 8.6.3). + +Where an ASCE does apply V.42 *bis* general compression to a particular data ASPDU, it shall set the `generalCompressionSpecifier` parameter to indicate that the ASPDU is V.42 *bis* general compressed. If the ASPDU is the first V.42 *bis* general compressed ASPDU after a V.42 *bis* encoder initialization, then the ASCE may also include the optional V.42 *bis* P1 and P2 parameters in the general `CompressionSpecifier` to allow peer ASCEs to optimize general compression-related resources. + +## 8.4 ASCE activation + +Within an AS session, an ASCE may be in one of the following three activation states: + +- An inactive ASCE is not participating in the sharing of windows (i.e., it is not hosting windows, drawing shadow windows, or sending or receiving AS input). When an ASCE is inactive, it need not retain local resources that are required for hosting and/or sharing. +- A pending active ASCE is in the process of becoming active and is not participating in the sharing of windows (i.e., it is not hosting windows, drawing shadow windows, or sending or receiving AS input). +- An active ASCE is cooperating with other active ASCEs to share windows. + +The following clauses describe ASCE activation and the handling of share identifiers for both legacy and base modes. + +### 8.4.1 ASCE activation (legacy mode) + +In the legacy mode of the AS protocol, ASCE activation and share identifier handling is largely independent of GCC and is performed using AS-specific protocol elements. + +An ASCE joins the AS non-standard base session (see clause 7) using a GCC-Application-Enroll request with the active/inactive flag set to active and with limited capabilities. This does not make the ASCE active (with respect to the AS session states described above) but does ensure that the ASCE is visible to other ASCEs within the conference. + +An ASCE may remain enrolled in the non-standard base session over a period, while moving from inactive to active state and back again a number of times. This distinction, between enrolment and activation, enables an ASCE to defer the commitment of application sharing-specific resources to those points within the conference where application sharing is actually taking place. + +An ASCE that wishes to become active shall send either a DemandActivePDU or a RequestActivePDU to all ASCEs within the conference in the manner indicated in Table 6-3. The content of the DemandActivePDU is shown in Table 8-26 and the content of the RequestActivePDU is shown in Table 8-27. + +It is recommended that an ASCE should initially send a RequestActivePDU to all ASCEs within the conference to determine if there are other active ASCEs in the AS session. If no active ASCEs respond to the RequestActivePDU, then, at some later point, when the ASCE wishes to start sharing, it should send a DemandActivePDU to all ASCEs within the conference to initiate activation. + +Sending a DemandActivePDU requires that the sending ASCE shall have generated a unique share identifier, whereas RequestActivePDU does not. Sending DemandActivePDU may force a change in the current agreed share identifier. See clause 8.4.2 for further information on share identifiers. + +On receipt of a DemandActivePDU, subject to successful capabilities negotiation (see clause 8.2), an ASCE may send ConfirmActivePDUs (see below) to all ASCEs within the conference. An inactive ASCE is not required to respond to a DemandActivePDU – it may choose to remain inactive. If an inactive ASCE responds to a DemandActivePDU, then it enters the active state. + +If an ASCE is already active, then, on receipt of a RequestActivePDU and subject to successful capabilities negotiation (see clause 8.2), it shall send ConfirmActivePDUs (see below) to all ASCEs within the conference. + +For both cases, the ConfirmActivePDU shall be sent to all ASCEs within the conference on all priority channels – high, medium and low – in the manner indicated in Table 6-3. The content of the ConfirmActivePDU is shown in Table 8-28. This ensures that any data on any channel is received after the ConfirmActivePDU. The first ConfirmActivePDU received on any channel causes the receiving pending inactive ASCE to enter the active state. Subsequent ConfirmActivePDUs shall be discarded. + +Figure 3 illustrates the use of RequestActivePDU, DemandActivePDU and ConfirmActivePDU in the activation of three ASCEs, where initially no ASCEs are active and ASCE 1 uses RequestActivePDU to determine the activation state of other ASCEs within the conference. ASCE 1 then starts sharing and uses DemandActivePDU to initiate the activation of the other ASCEs within the conference. + +See Figure 5 for a phase diagram summary of allowable transitions between ASCE states. + +![Sequence diagram showing the successful activation of three ASCEs (ASCE 1, ASCE 2, ASCE 3) in legacy mode. ASCE 1 starts sharing, sends RequestActivePDU and DemandActivePDU to ASCE 2 and ASCE 3. ASCE 2 and ASCE 3 ignore the RequestActivePDU but become active upon receiving DemandActivePDU. All three then send ConfirmActivePDU back to ASCE 1.](38cbce07f83fba6d5a7c46605bd5743f_img.jpg) + +``` + +sequenceDiagram + participant ASCE1 as ASCE 1 + participant ASCE2 as ASCE 2 + participant ASCE3 as ASCE 3 + + Note over ASCE1: (ASCE 1 is inactive) + Note over ASCE2: (ASCE 2 is inactive) + Note over ASCE3: (ASCE 3 is inactive) + + ASCE1->>ASCE2: RequestActivePDU with CombinedCapabilities + ASCE1->>ASCE3: RequestActivePDU with CombinedCapabilities + Note over ASCE2: (RequestActivePDU ignored) + Note over ASCE3: (RequestActivePDU ignored) + + Note over ASCE1: (ASCE 1 starts sharing) + ASCE1->>ASCE2: DemandActivePDU with CombinedCapabilities + ASCE1->>ASCE3: DemandActivePDU with CombinedCapabilities + Note over ASCE2: (ASCE 2 is active) + Note over ASCE3: (ASCE 3 is active) + + ASCE2->>ASCE1: ConfirmActivePDU with CombinedCapabilities (all priorities) + ASCE3->>ASCE1: ConfirmActivePDU with CombinedCapabilities (all priorities) + + Note over ASCE1: (ASCE 1 is active) + +``` + +T.128(08)\_F03 + +→ AS-CHANNEL + +Sequence diagram showing the successful activation of three ASCEs (ASCE 1, ASCE 2, ASCE 3) in legacy mode. ASCE 1 starts sharing, sends RequestActivePDU and DemandActivePDU to ASCE 2 and ASCE 3. ASCE 2 and ASCE 3 ignore the RequestActivePDU but become active upon receiving DemandActivePDU. All three then send ConfirmActivePDU back to ASCE 1. + +**Figure 3 – Successfully activating three ASCEs (legacy mode)** + +**Table 8-26 – DemandActivePDU** + +| Parameter | Description | +|-----------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareControl header | The ShareControl header is described in clause 8.3. | +| shareID | This parameter is the proposed share identifier for use within the AS session. See clause 8.4.2 for a description of this parameter. | +| sourceDescriptor | This parameter is a null-terminated T.50 text string identifying this ASCE suitable for display to an end-user. This Recommendation does not place any interpretation upon the string contents. | +| combinedCapabilities | This parameter is a list of this ASCE's combined capabilities, which contains one copy of each of the legacy mode capability sets in any order. See clause 8.2 for further information on capabilities. | + +**Table 8-27 – RequestActivePDU** + +| Parameter | Description | +|-----------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareControl Header | The ShareControl header is described in clause 8.3. | +| sourceDescriptor | This parameter is a null-terminated T.50 text string identifying this ASCE suitable for display to an end-user. This Recommendation does not place any interpretation upon the string contents. | +| combinedCapabilities | This parameter is a list of this ASCE's combined capabilities, which contains one copy of each of the legacy mode capability sets in any order. See clause 8.2 for further information on capabilities. | + +**Table 8-28 – ConfirmActivePDU** + +| Parameter | Description | +|-----------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareControl header | The ShareControl header is described in clause 8.3. | +| shareID | This parameter is the current share identifier in use within the AS session. See clause 8.4.2 for a description of this parameter. | +| originatorID | This parameter is the MCS user ID of the ASCE that issued the DemandActivePDU or RequestActivePDU to which this is a response. This enables an ASCE receiving this ConfirmActivePDU to correlate it with a previous DemandActivePDU or RequestActivePDU. | +| sourceDescriptor | This parameter is a null-terminated T.50 text string identifying this ASCE suitable for display to an end-user. This Recommendation does not place any interpretation upon the string contents. | +| combinedCapabilities | This parameter is a list of this ASCE's combined capabilities, which contains one copy of each of the legacy mode capability sets in any order. See clause 8.2 for further information on capabilities. | + +To deactivate another active ASCE, an ASCE shall send a DeactivateOtherPDU to the ASCE that is to be deactivated in the manner indicated in Table 6-3. The content of the DeactivateOtherPDU is shown in Table 8-29. On receipt of a DeactivateOtherPDU, an ASCE shall become inactive. It is recommended that an ASCE should only issue DeactivateOtherPDU where it has received a DemandActivePDU, RequestActivePDU or ConfirmActivePDU with capabilities that would seriously affect the successful progress of application sharing within the conference. This situation should not occur where other ASCEs provide capabilities that conform to the legacy mode of the AS protocol. + +An ASCE may deactivate all active ASCEs by sending a DeactivateAllPDU to all ASCEs within the conference in the manner indicated in Table 6-3. The content of the DeactivateAllPDU is shown in Table 8-31. On receipt of a DeactivateAllPDU, an ASCE shall become inactive. It is recommended that an ASCE should only issue DeactivateAllPDU in exceptional circumstances. + +When an ASCE determines that there are no other active ASCEs within the AS session, it shall become inactive. + +When an ASCE becomes inactive, it shall send a DeactivateSelfPDU to all ASCEs within the conference in the manner indicated in Table 6-3. The content of the DeactivateSelfPDU is shown in Table 8-30. + +Figure 4 illustrates the use of DeactivateOtherPDU and DeactivateSelfPDU where ASCE 1 deactivates ASCE 3. On receipt of the DeactivateOtherPDU, ASCE 3 sends DeactivateSelfPDU to ASCEs 1 and 2, whereby both receive notification that ASCE 3 has become inactive. + +![Sequence diagram showing the deactivation of ASCE 3 by ASCE 2. ASCE 1 and ASCE 2 are active, while ASCE 3 is inactive. ASCE 2 sends a DeactivateOtherPDU to ASCE 3. ASCE 2 also sends a DeactivateSelfPDU to ASCE 1. Below the diagram, two channels are shown: AS-CHANNEL (solid line) and AS-{MCS-USER-ID}-CHANNEL (dashed line).](5ee1bbbf85b473f78af9ec8368a4159a_img.jpg) + +ASCE 1                                      ASCE 2                                      ASCE 3 + +DeactivateOtherPDU + +DeactivateSelfPDU + +(ASCE 3 is inactive) + +AS-CHANNEL + +AS-{MCS-USER-ID}-CHANNEL + +T1602340-97 + +Sequence diagram showing the deactivation of ASCE 3 by ASCE 2. ASCE 1 and ASCE 2 are active, while ASCE 3 is inactive. ASCE 2 sends a DeactivateOtherPDU to ASCE 3. ASCE 2 also sends a DeactivateSelfPDU to ASCE 1. Below the diagram, two channels are shown: AS-CHANNEL (solid line) and AS-{MCS-USER-ID}-CHANNEL (dashed line). + +**Figure 4 – Deactivating another ASCE** + +**Table 8-29 – DeactivateOtherPDU** + +| Parameter | Description | +|----------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareControl header | The ShareControl header is described in clause 8.3. | +| shareID | This parameter is the current share identifier in use within the AS session. See clause 8.4.2 for a description of this parameter. | +| deactivateID | This parameter is the MCS user ID of the ASCE to be deactivated. | +| sourceDescriptor | This parameter is a null-terminated T.50 text string identifying this ASCE suitable for display to an end-user. This Recommendation does not place any interpretation upon the string contents. | + +**Table 8-30 – DeactivateSelfPDU** + +| Parameter | Description | +|----------------------------|------------------------------------------------------------------------------------------------------------------------------------| +| ShareControl header | The ShareControl header is described in clause 8.3. | +| shareID | This parameter is the current share identifier in use within the AS session. See clause 8.4.2 for a description of this parameter. | + +**Table 8-31 – DeactivateAllPDU** + +| Parameter | Description | +|----------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareControl header | The ShareControl header is described in clause 8.3. | +| shareID | This parameter is the current share identifier in use within the AS session. See clause 8.4.2 for a description of this parameter. | +| sourceDescriptor | This parameter is a null-terminated T.50 text string identifying this ASCE suitable for display to an end-user. This Recommendation does not place any interpretation upon the string contents. | + +### 8.4.2 Share identifiers (legacy mode) + +A share identifier is a unique 32-bit handle present in (almost) all ASPDUs, which ASCEs use to detect and ignore "late" data generated with respect to previous activations and capabilities within the AS session. In the legacy mode of the AS protocol, share identifiers are constructed locally by + +each ASCE and consist of the ASCE's MCS user ID (in the most significant 16 bits) and a monotonically increasing $2^{16}$ unsigned and wrapping counter (in the least significant 16 bits). + +In the legacy mode of the AS protocol, the following ASPDUs do not contain share identifiers. All other legacy mode ASPDUs contain share identifiers. + +- RequestActivePDU: See clause 8.4.1. +- FlowTestPDU: See clause 8.5. +- FlowResponsePDU: See clause 8.5. +- FlowStopPDU: See clause 8.5. + +Each ASCE in an AS session shall maintain a local share identifier, which is its view of the current share identifier in use within the session, as follows: + +- When an ASCE is inactive or has issued a RequestActivePDU, it shall set its local share identifier to the special value invalid. +- An ASCE shall generate a new proposed share identifier (by incrementing the counter part of the previous share identifier) when issuing a DemandActivePDU and shall set its local share identifier to that new identifier. +- An ASCE shall check the share identifier in an incoming DemandActivePDU or ConfirmActivePDU against its local share identifier and shall update its local share identifier as follows: + - If its local share identifier is invalid, it shall set its local share identifier to the share identifier in the incoming ASPDU. + - If its local share identifier is valid, it shall set its local share identifier to the higher value of the two share identifiers. Note that, because share identifiers are formed from a combination of MCS user ID and a local counter, the share identifier values cannot be equal. +- On receipt of a RequestActivePDU (when active), an ASCE shall set the share identifier value in its subsequent ConfirmActivePDU to its local share identifier. +- On issuing a DeactivateSelfPDU or DeactivateAllPDU, or on receipt of a DeactivateOtherPDU or DeactivateAllPDU, or when there are no other active ASCEs in the session, an ASCE shall set its local share identifier to the special value invalid. +- On receipt of all other ASPDUs containing a share identifier (see above), an ASCE shall discard the ASPDU where the share identifier value in the ASPDU does not match its local share identifier. + +The net of the above is that ASCEs using the legacy mode of the AS protocol within an AS session cooperate to maintain a current agreed share identifier for all active ASCEs, with the current agreed share identifier potentially changing as new ASCEs become active. + +Figure 5 presents a phase diagram summarizing the allowable transitions between ASCE states with respect to share identifier value. This shows two substates of the pending active state, depending on whether the ASCE has a proposed or invalid share identifier. It does not show ASPDUs and state/share identifier combinations that do not cause state transitions, nor does it show ASCE actions associated with state transitions. + +![Figure 5: ASCE state transitions and share identifier management (legacy mode). The diagram shows four states: Inactive (invalid ID), Pending active (proposed ID), Pending active (invalid ID), and Active (agreed ID). Transitions are triggered by various events like Send DemandActive, Send RequestActive, Receive DeactivateOther, etc.](2580688a4de0a29692805cc6ba4822d7_img.jpg) + +``` + +graph TD + Inactive((Inactive +(invalid ID))) + PendingProposed((Pending active +(proposed ID))) + PendingInvalid((Pending active +(invalid ID))) + Active((Active +(agreed ID))) + + Inactive -- "Send DemandActive" --> PendingProposed + Inactive -- "Send DemandActive" --> PendingInvalid + Inactive -- "Send RequestActive" --> PendingProposed + Inactive -- "Receive DeactivateOther +Receive DeactivateAll +Send DeactivateSelf +Send DeactivateAll" --> PendingProposed + Inactive -- "Receive DeactivateOther +Receive DeactivateAll +Send DeactivateSelf +Send DeactivateAll" --> PendingInvalid + Inactive -- "Receive DemandActive" --> Active + PendingProposed -- "Receive ConfirmActive +Receive DemandActive" --> Active + PendingInvalid -- "Receive ConfirmActive +Receive DemandActive" --> Active + Active -- "Receive DeactivateOther +Receive DeactivateAll +Send DeactivateSelf +Send DeactivateAll +No other Active ASCEs" --> Inactive + Active -- "Receive DeactivateOther +Receive DeactivateAll +Send DeactivateSelf +Send DeactivateAll" --> PendingInvalid + +``` + +T1602350-97 + +Figure 5: ASCE state transitions and share identifier management (legacy mode). The diagram shows four states: Inactive (invalid ID), Pending active (proposed ID), Pending active (invalid ID), and Active (agreed ID). Transitions are triggered by various events like Send DemandActive, Send RequestActive, Receive DeactivateOther, etc. + +**Figure 5 – ASCE state transitions and share identifier management (legacy mode)** + +### 8.4.3 ASCE activation and share identifiers (base mode) + +In the base mode of the AS protocol, ASCE activation shall be performed according to [ITU-T T.121]. + +A share identifier is a unique 32-bit handle present in (almost) all ASPDUs, which ASCEs use to detect and ignore "late" AS data generated with respect to previous capabilities within the AS session. In the base mode of the AS protocol, an ASCE shall use the last roster instance number supplied by a GCC-Application-Roster-Report indication on the standard base session that contains both itself and other ASCEs enrolled active as its current share identifier. + +In the base mode of the AS protocol, the following ASPDUs do not contain share identifiers. All other base mode ASPDUs contain share identifiers. + +- FlowTestPDU: See clause 8.5. +- FlowResponsePDU: See clause 8.5. +- FlowStopPDU: See clause 8.5. + +While the use of share identifiers allows an ASCE to avoid the use of "late" AS data, it is possible for an ASCE to receive "early" AS data that have been generated with respect to capabilities that have not yet been seen by the receiving ASCE. This occurs because GCC distributes roster + +information via the GCC top provider while AS data are sent using (non-uniform) MCS-Send-Data primitives. This means that, for a simple example for a conference with two ASCEs (ASCEs A and B), where each of the ASCEs enrol active at about the same time, then: + +- ASCE A may receive a roster report containing the capabilities for ASCEs A and B at time $t_1$ ; +- based on those capabilities, ASCE A starts sending AS data to ASCE B at time $t_2$ ; +- the AS data from ASCE A may arrive at ASCE B at time $t_3$ ; at this point, ASCE B has not received a roster report containing A; +- ASCE B may receive a roster report containing the capabilities for ASCE A at time $t_4$ . + +An ASCE can detect "early" AS data by the fact that the data's share identifier will be greater modulo $2^{16}$ than the last roster instance number supplied by a GCC-Application-Roster-Report indication on the standard base session. For this case, an ASCE shall process in advance or buffer such data until a GCC-Application-Roster-Report indication is received that identifies a roster instance number which is greater modulo $2^{16}$ than or equal to the one specified in the data. If an ASCE chooses to process such data in advance of the receipt of the proper GCC-Application-Roster-Report indication, it shall not assume that the capabilities corresponding to the data are within the bounds defined by its own capabilities, given that the roster change prompting the new application roster may have been triggered by the ASCE being either forcibly or voluntarily removed from the AS session. + +## 8.5 Flow control + +A key performance factor for application sharing is the ability to tailor the protocol content based on the potential traffic presented by local hosted window activity and the instantaneous aggregate bandwidth to other nodes to achieve maximum throughput and responsiveness. During the course of an AS session, the aggregate bandwidth available for application sharing will vary depending on a wide range of factors, including: + +- the conference topology and link speeds; +- the activation status and behaviour of other ASCEs; +- the presence and/or behaviour of other APEs – such as T.126 and/or T.127 APEs; +- other services (such as video and/or audio) originating or terminating on nodes involved in the conference; +- the general traffic load (on shared, non-dedicated) networks. + +As the instantaneous aggregate bandwidth available for application sharing is reduced, an ASCE may need to scale back the amount of data in flight in the network (e.g., by collapsing multiple overlapping screen updates, increasing compression ratios, etc.) such that, while the frequency of remote screen updates is reduced, overall responsiveness is maintained and, in particular, remote users on slower links do not "fall behind" the conference. As more instantaneous aggregate bandwidth is available for application sharing, an ASCE may be able to increase the amount of data in flight in the network, such that the frequency of remote screen updates and actual responsiveness is improved. + +For an ASCE to effectively adjust its protocol content in this manner requires multipoint aggregate end-to-end flow control. Unfortunately, MCS does not define a suitable flow control mechanism. Therefore, this Recommendation defines an AS protocol-specific mechanism – AS flow control – whereby ASCEs can obtain information derived from the instantaneous aggregate bandwidth available to application sharing, which allows them to tailor their AS protocol stream accordingly. + +AS flow control is applied on a per-channel and per-priority basis. A particular channel/priority combination is referred to as a flow. Flow control may be applied to none, some or all flows. This Recommendation only applies flow control to AS-CHANNEL flows and does not apply flow + +control to AS-**{MCS-USER-ID}**-CHANNEL flows – that is, flow control is only applied to broadcast channel/priority combinations. This means that an ASCE can support up to three controlled flows per AS session. + +For each controlled flow, an ASCE specifies a target round trip time and a target maximum amount of data in flight. While those targets are in force, an ASCE monitors the aggregate round trip time for that flow, via exchanges of FlowTestPDUs and corresponding FlowResponsePDUs (see below) and monitors the amount of data in flight, while seeking to maximize the amount of data in flight (up to the target maximum) and maintaining the target round trip time. + +Where flow control is applied to a particular flow, an ASCE shall periodically send a FlowTestPDU for that flow to other ASCEs within the conference in the manner indicated in Table 6-3. The content of the FlowTestPDU is shown in Table 8-32. On receipt of a FlowTestPDU, an ASCE shall reply with a FlowResponsePDU to the issuing ASCE in the manner indicated in Table 6-3. The content of the FlowResponsePDU is shown in Table 8-33. The receipt of a FlowResponsePDU provides an estimate of the round trip delay to the particular responding ASCE. Note that this definition of round trip time includes all time spent in local, intermediate and final destination node queues and is therefore an estimate of end-to-end delivery time to the remote ASCE. + +**Table 8-32 – FlowTestPDU** + +| Parameter | Description | +|------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| flowID | This parameter identifies the controlled flow for the sending ASCE. The allowable values are in the range 0..127. This parameter is allocated by the sending ASCE and has no specific correlation with particular channels and/or priorities. | +| flowNumber | This parameter identifies this particular FlowTestPDU for this flowID (see above). The allowable values are in the range 0..255. An ASCE should increment this parameter for each successive FlowTestPDU, wrapping to 0 after using 255. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +**Table 8-33 – FlowResponsePDU** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| flowID | This parameter identifies the controlled flow for the sending ASCE. The allowable values are in the range 0..127. The sending ASCE shall set this parameter to that used in the corresponding FlowTestPDU. | +| flowNumber | This parameter identifies this particular FlowResponsePDU on this flowID (see above). The allowable values are in the range 0..255. The sending ASCE shall set this parameter to that used in the corresponding FlowTestPDU. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +An ASCE is required to issue FlowTestPDUs periodically and is required to respond to FlowTestPDUs with FlowResponsePDUs – except where it has previously sent a FlowStopPDU (see below). + +An ASCE should use the round trip times provided by the series of exchanges of FlowTestPDUs and FlowResponsePDUs to: + +- maintain a dynamic estimate of the aggregate throughput for each controlled flow; +- adjust the sending of FlowTestPDUs and FlowResponsePDUs to reflect the estimate of the aggregate throughput; +- adjust the content of the outgoing AS protocol data stream to reflect the estimate of the aggregate throughput (see clause 8.5.2). + +The implementation of efficient and predictable ASCE flow control is a major determinant in application sharing performance and usability. Therefore, this Recommendation requires that ASCEs implement a flow control algorithm either equivalent to, or superior to, the algorithm described in clause 8.5.1 below. + +### 8.5.1 Flow control algorithm + +The following flow control algorithm is described in terms of a set of flow control constants and variables, a set of specific operations on those variables and logic which describes under what conditions those operations are performed. Appendix I provides suggested constant values, initial, minima and maxima values for the flow control variables and suggested expressions for the operations, based on experience with a particular ASCE implementation. However, different ASCE implementations may find that different values and/or expressions deliver the required equivalent or superior flow control behaviour. + +- An ASCE uses the following flow control constant values per controlled flow: + - target\_round\_trip This is the target round trip time for the flow. + - target\_in\_flight This is the target maximum number of octets that can be in flight for the flow. + - max\_queued\_recv This is the maximum number of received ASPDUs that can be locally queued for the flow before FlowResponsePDUs responses are deferred. + +Appendix I provides suggested values for these flow control constants based on experience with a particular ASCE implementation. + +- An ASCE maintains the following flow control variables per controlled flow: + - max\_in\_flight This is the current maximum number of octets that can be in flight for the flow. + - flow\_period This is the current minimum period between sending FlowTestPDUs. + +These variable values are adjusted dynamically (see below) based on the data sent by the ASCE and on the observed round trip delay to other ASCEs. + +Appendix I provides suggested initial values and minima and maxima for these flow control variables based on experience with a particular ASCE implementation. + +- An ASCE may perform the following operations on the flow control variables: + - Decrease max\_in\_flight; + - Increase max\_in\_flight; + - Decrease flow\_period; + - Increase flow\_period; + +Appendix I provides suggested expressions for these operations based on experience with a particular ASCE implementation. + +- When sending data for a controlled flow, an ASCE should check whether this data results in the number of octets in flight exceeding `max_in_flight`. + - Where that is not the case, the ASCE should send the data. + - Where that is the case, the ASCE should not send the data (i.e., the flow control algorithm is applying local back pressure within the ASCE). + +How back pressure is applied within the ASCE is a local matter. + +- On receipt of a FlowTestPDU, an ASCE should check whether it is still processing more than `max_queued_recv` ASPDUs on the flow. + - Where that is not the case, it should respond with a FlowResponsePDU referencing that flow and using the flowNumber supplied in the FlowTestPDU. + - Where that is the case, it should pend the FlowResponsePDU until the local backlog has been reduced – i.e., until the number of locally queued ASPDUs on the flow is less than or equal to `max_queued_recv`. + +The check for a backlog of previously received data avoids problems where a receiving ASCE is the slowest element in the end-to-end network, where an unconditional FlowResponsePDU would result in an accumulation of unprocessed data at the receiver. + +- On receipt of a FlowResponsePDU, an ASCE should check whether the flow control algorithm is applying local back pressure. + - Where that is not the case, no action is necessary. + - Where that is the case and the round trip delay is worse than the `target_round_trip`, it should decrease `max_in_flight` and increase `flow_period`. This will have the effect of reducing throughput by encouraging earlier back pressure. + - Where that is the case and the round trip delay is better than the `target_round_trip`, it should increase `max_in_flight`. This will have the effect of lifting back pressure and increasing throughput when data is next sent (provided a worse round trip delay does not happen in the interim). If the new `max_in_flight` has reached `target_in_flight`, then the ASCE should also decrease `flow_period`. This will have the effect of increasing the algorithm's sensitivity to any deterioration in round trip times as a result of the increased data in flight. + +This means that the ASCE will only adjust `max_in_flight` or `flow_period` where local back pressure is being applied. This is because this algorithm uses the observed round trip as an estimate of throughput, which is only a reasonable correlation where the round trip coincides with a period of busy data traffic – i.e., when this ASCE is applying local back pressure because there are at least `max_in_flight` octets in flight. + +Note that an ASCE should take care that successive estimates of round trip during local back pressure do not result in oscillation – for example, where successive round trips within the same `flow_period` are worse than the target (resulting in a decrease in `max_in_flight` and increase in `flow_period`) and then better than the target (resulting in an increase in `max_in_flight` and possible decrease in `flow_period`). A recommended heuristic approach is to bias the decision such that a reduction in throughput is effected for cases where the round trip is simply worse than the `target_round_trip`, whereas an increase in throughput is only affected for cases where the round trip is less than half of the `target_round_trip`. + +The ASCE should apply this logic for each received FlowResponsePDU within a `flow_period` – with the early responders setting initial values for the period and later responders adjusting those values to reflect the bandwidth characteristics applicable to the corresponding ASCEs. + +The `flow_period` is the current minimum time between FlowTestPDUs. For example, if the `flow_period` is five milliseconds, then if an ASCE sends a FlowTestPDU at the start of a + +flow\_period and receives FlowResponsePDUs from all responding ASCEs (see below) within four milliseconds, then it should not send the next FlowTestPDU for a further millisecond. Conversely, if it has not received FlowResponsePDUs for all responding ASCEs within five milliseconds, it should not send the next FlowTestPDU until it has received FlowResponsePDUs for all responding ASCEs or some larger upper time bound has been reached. This approach means that, for a particular flow\_period, the algorithm incrementally responds to the observed round trip for all responding ASCEs – provided they respond within a reasonable time. + +The group of responding ASCEs for which responses are expected within a flow\_period may not necessarily correspond to the group of all other active ASCEs. A sending ASCE should only include an ASCE within its group of responding ASCEs when that ASCE has provided an initial response and should exclude ASCEs that do not respond within the upper time bound (at least, until such ASCEs respond again within subsequent flow\_periods). This approach ensures that faulty ASCEs do not skew the algorithm. + +The net of the above is that sending ASCEs will (for a particular flow): + +- apply local back pressure when the amount of data in flight reaches the current allowable data in flight; +- increase or decrease the allowable data in flight to reflect the aggregate instantaneous bandwidth, based on the observed round trip delay; +- increase or decrease the flow\_period (and thus the proportion of bandwidth occupied by flow ASPDUs) to reflect the aggregate instantaneous bandwidth. + +An ASCE may remove itself from other ASCEs' flow control responding groups by sending a FlowStopPDU for that flow to all other ASCEs within the conference in the manner indicated in Table 6-3. The content of the FlowStopPDU is shown in Table 8-34. This mechanism is primarily of use in the legacy mode of the AS protocol, as it allows an ASCE to remain enrolled in the AS-CHANNEL (and therefore still receiving FlowTestPDUs) but to be inactive (in the sense of ASCE activation – see clause 8.4) and ensures that its failure to respond does not skew other active ASCEs' flow control calculations. + +When the ASCE again wishes to be included in flow control calculations, it should respond to the next FlowTestPDU with a FlowResponsePDU, which will have the effect of adding it back into other ASCEs' flow control responding groups for that flow. + +**Table 8-34 – FlowStopPDU** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| flowID | This parameter identifies the controlled flow for the sending ASCE. The allowable values are in the range 0..127. The sending ASCE shall set this parameter to that used in the corresponding FlowTestPDU. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.5.2 Response to back pressure + +When back pressure is being applied within the ASCE as a result of the flow control algorithm described in clause 8.5.1, an ASCE may process pending AS data such that the volume of the data is reduced. + +Example strategies for output AS data include the following: + +- Switching between sending orders and bitmap data: + +Where a local application is very actively drawing into a hosted window and the ASCE is experiencing flow control back pressure, the ASCE may prefer to accumulate bounds information for the drawing activity, rather than sending the orders, and then subsequently send bitmap data for the accumulated bounds. This may reduce the frequency of updates at remote ASCEs, but will minimize the data in flight and ensures that remote ASCEs "keep up" with the drawing activity. The switching points between orders and bitmap data and vice versa will depend on application drawing behaviour, flow control and the particular ASCE implementation. + +- Collapsing overlapping updates – this process is referred to as spoiling: + +Where the ASCE is experiencing flow control back pressure and the local application draws a sequence of overlapping or occluding order or bitmap data updates, then the sequence may (in some cases) be collapsed into a smaller sequence and/or a single update. Again, this may reduce the frequency of updates at remote ASCEs, but will minimize the data in flight and ensure that remote ASCEs "keep up" with the drawing activity. + +Where an ASCE is experiencing flow control back pressure and there is a high level of end-user pointing device activity, the ASCE may collapse a sequence of pointing device move events into a single move – this process is referred to as input spoiling. Input spoiling may also be applied at the hosting ASCE, where a sequence of pointing device events is queued within the ASCE awaiting injection into the local terminal environment. Both send and receive input spoiling may reduce the frequency of pointing device move updates presented to hosted windows and therefore degrade the smoothness of pointing device movement, but will minimize the data in flight and ensure that remote ASCEs "keep up" with the pointing device activity. + +This Recommendation does not specify how an ASCE should adjust the content of either the output or input AS protocol data streams when back pressure is in effect, but does require that the ASCE shall ensure that the protocol stream contains sufficient information to allow peer ASCEs to correctly display shadow windows and/or correctly control hosted applications. Similarly, where the output stream relies on control information (such as window list or palette information) that has changed on the hosting ASCE, it is the hosting ASCE's responsibility to ensure that the control information is sent prior to the output. All order-dependent control and output ASPDUs are sent at low priority, so that the sending ASCE can reliably order such output. + +## **8.6 Synchronization** + +When an ASCE is active within an AS session, there are several classes of session events that may require it to update protocol-related resources and/or state, or to send ASPDUs which allow other ASCEs to perform complementary changes. The ASCE processing associated with these session events is referred to as synchronization. + +The AS protocol defines four classes of synchronization – referred to as ASCE, hosting, shadow and input synchronization. Each synchronization class defines a related set of ASCE synchronization requirements associated with a particular range of session events. For example, hosting synchronization defines a set of synchronization requirements that apply to an ASCE that is hosting (or starting or stopping hosting) windows. + +This clause provides a summary of those ASCE synchronization operations required to support the AS protocol. It does not describe each operation in detail, but rather references subclauses elsewhere in this Recommendation that describe the relevant functional area. + +Where the description references a particular local resource, such as an identifier value or a sending cache, it does so in logical terms, which do not assume a particular local ASCE implementation – the only requirement is that the synchronizing ASCE (subsequently) achieves the required protocol effect. In addition, it does not address potential optimizations that may arise from collapsing a series of repeated synchronization operations. + +### 8.6.1 ASCE synchronization + +When an ASCE becomes active, it shall perform the following synchronization operations. See clause 8.4 for further information on ASCE activation and deactivation. + +- It shall set its window list identifier sequence number part to zero. See clause 8.10 for further information. +- It shall set its window activation identifier to zero. See clause 8.11 for further information. +- It shall set its control identifier to zero. See clause 8.12 for further information. + +The AS protocol does not require any specific synchronization when an ASCE becomes inactive. + +When an active ASCE detects that another ASCE has become active, it shall perform the following synchronization operations: + +- It shall determine the negotiated capabilities for all (i.e., existing and new) active ASCEs within the AS session and use these capabilities as the basis for constructing all subsequent data ASPDUs. See clause 8.2 for further information on capabilities and capabilities negotiation. +- Before sending any other data ASPDUs, it shall send a SynchronizePDU on all outgoing streams/priorities (see clause 8.3.1) to all ASCEs within the conference in the manner indicated in Table 6-3 and shall mark all incoming streams/priorities for each other active ASCE as pending synchronization. Each incoming stream/priority for each other active ASCE remains pending synchronization until it receives a SynchronizePDU – and until that point discards all incoming data ASPDUs on that stream/priority from the particular ASCE. This ensures that, where the share identifier does not change as a result of the new ASCE becoming active (see clause 8.4.2), any data arriving from other ASCEs relating to the previous negotiated combined capabilities is discarded. A particular SynchronizePDU is directed on a single stream/priority for a particular other active ASCE, but is sent on the AS-CHANNEL (and therefore to all ASCEs). Each SynchronizePDU includes the MCS user ID of the intended target ASCE, so that it can be discarded by ASCEs that are not the intended target. This mechanism ensures that the SynchronizePDU arrives before any broadcast data for the target ASCE. The content of the SynchronizePDU is shown in Table 8-35. +- It shall discard its list of matched fonts, reset its count of received FontPDUs and may send a FontPDU to re-advertise its set of matchable fonts. See clause 8.8 for further information. +- It shall send either a cooperate or detach ControlPDU to advertise its control state. If it is cooperating and it has the control identifier, it also shall send a grant control ControlPDU referencing itself to all active ASCEs to advertise that it owns the control identifier. See clause 8.12 for further information. +- If the ASCE is hosting windows, it shall also perform the relevant hosting synchronization operations (see clause 8.6.2 below). +- It shall perform the relevant input synchronization operations (see clause 8.6.4 below). + +ASCE synchronization as a result of other ASCEs becoming active may generate significant local processing load and significant ASPDU traffic, especially where it also initiates host synchronization. It is recommended that where an ASCE detects that a number of other ASCEs have become active in the conference in close succession, it implements ASCE synchronization so that it defers some or all of the required synchronization for each newly-active ASCE until a significant proportion or all of the ASCEs are active, with the proviso that the deferment is time limited in proportion to the number of ASCEs in the group, and some arbitrary maximum, and that responsiveness to activation is maintained. + +When another ASCE becomes inactive, an ASCE may be required to perform the following synchronization operations. See clause 8.4 for further information on ASCE activation and deactivation. + +- Where the other ASCE becoming inactive, results in the local ASCE becoming inactive (because it is the only active ASCE remaining within the AS session), then no ASCE synchronization is required. +- Where the ASCE that became inactive owned the control identifier, then each remaining active ASCE is required to participate in an exchange of ControlPDUs to re-establish a single ASCE as the control identifier owner. See clause 8.12.1 for further information. +- Where other ASCEs remain active, the local ASCE may redetermine the negotiated capabilities (see clause 8.2) for all remaining active ASCEs within the AS session and use these capabilities as the basis for constructing all subsequent data ASPDUs. This is optional, as the negotiated capabilities for the previously active ASCEs were negotiated inclusive of the remaining ASCEs, and while the renegotiated capabilities may allow for the construction of a more optimal AS protocol stream, the previously negotiated capabilities are still valid. See clause 8.2 for further information. +- Where other ASCEs remain active, the local ASCE may also rematch its list of matched fonts based on the font information received from the remaining active ASCEs. Again, this is optional and while it may result in additional matched fonts, the previously matched fonts are still valid. See clause 8.8 for further information. + +**Table 8-35 – SynchronizePDU** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| targetUser | This parameter is the MCS user ID of the ASCE to which this ASPDU is directed. Where an ASCE receives a SynchronizePDU containing a MCS user ID other than its own, it shall discard it. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.6.2 Hosting synchronization + +Hosting synchronization is the set of synchronization operations that are associated with the hosting of windows. + +When an ASCE first starts hosting windows, when it is hosting windows and a new ASCE becomes active, or when it is hosting windows and a capability set is updated (see clause 8.2), it shall perform the following synchronization operations: + +- It shall send an UpdatePDU (synchronization) to all ASCEs within the conference in the manner indicated in Table 6-3. The UpdatePDU (synchronization) shall be sent before any other ASPDUs generated by the sending ASCE as a result of hosting synchronization and notifies other ASCEs that this ASCE is hosting windows. On receipt of an UpdatePDU (synchronize), an ASCE shall perform any relevant shadow synchronization (see clause 8.6.3 below). The content of the UpdatePDU (synchronization) is shown in Table 8-36. +- It shall reset its sending colour pointer cache. See clause 8.14 for further information. +- In the base mode of the AS protocol only, it shall reset its sending colour space to RGB with no colour accuracy information. + +- It shall pend the sending of an UpdatePDU (palette) with a new palette, which shall be sent before any subsequent bitmap data. +- It shall reset its order encoding state. See clause 8.16.3 for further information. +- It shall reset its sending bitmap cache. See clause 8.16.7 for further information. +- It shall reset its sending ColorTable cache. See clause 8.16.8 for further information. +- It shall reset its sending desktop save cache. See clause 8.16.17 for further information. +- It shall send an ApplicationPDU with action NotifyHostedApplications indicating the number of hosted applications on the local terminal. +- It shall send a WindowListPDU containing information on the current local window structure, which shall be sent before any WindowActivation. See clause 8.10 for further information. +- It shall send a WindowActivationPDU providing information on the local window activation status. See clause 8.11 for further information. +- It shall queue a desktop origin order, which shall be sent in an UpdatePDU (orders) ASPDU before any subsequent bitmap data or orders. See clause 8.16.18 for further information. +- It shall construct an AS output stream, consisting of a mixture of bitmap data and/or orders, containing sufficient information to allow other ASCEs to draw shadow windows corresponding to its hosted windows. + +When an ASCE stops hosting windows, but remains active, it shall send an ApplicationPDU with action NotifyHostedApplications indicating that zero applications are now hosted, to allow other ASCEs to perform any required shadow synchronization. + +**Table 8-36 – UpdatePDU (synchronization)** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.6.3 Shadow synchronization + +Shadow synchronization is the set of synchronization operations that are associated with the drawing of shadow windows. It is performed with respect to one other or all other hosting ASCEs. + +When an ASCE receives an UpdatePDU (synchronization) from another ASCE (see clause 8.6.2), it is required to perform shadow synchronization with respect to that hosting ASCE. Where an ASCE determines that a capability set has been updated (in legacy mode, on receipt of an UpdateCapabilityPDU; in base mode, on receipt of a GCC-Application-Roster-Report indication with changed capabilities), it is required to perform shadow synchronization with respect to all hosting ASCEs. Where shadow synchronization is required, an ASCE shall perform the following synchronization operations for each affected hosting ASCE: + +- It shall reset its receiving colour pointer cache for that hosting ASCE. See clause 8.14 for further information. +- In the base mode of the AS protocol only, it shall reset its receiving colour space for that hosting ASCE to RGB with no colour accuracy information. +- It shall reset its order decoding state for that hosting ASCE. See clause 8.16.3 for further information. + +- It shall reset its receiving bitmap cache for that hosting ASCE. See clause 8.16.7 for further information. +- It shall reset its receiving ColorTable cache for that hosting ASCE. See clause 8.16.8 for further information. +- It shall reset its receiving desktop save cache for that hosting ASCE. See clause 8.16.17 for further information. +- It shall reset its desktop origin to (0,0) for that hosting ASCE. See clause 8.16.18 for further information. + +The AS protocol does not require any specific synchronization when an ASCE detects that another ASCE is no longer hosting – for example, when a hosting ASCE becomes inactive or the ASCE receives an ApplicationPDU with action NotifyHostedApplications indicating that zero applications are hosted on a (previously) hosting ASCE. However, an ASCE may use the receipt of an ApplicationPDU with action NotifyHostedApplications and zero applications to free local resources (such as receive caches) that were allocated with respect to that ASCE. + +### **8.6.4 Input synchronization** + +Input synchronization is the set of synchronization operations that are associated with the maintenance of keyboard state between controlling and controlled ASCEs. See clause 8.18 for further information. + +When an ASCE detects that a new ASCE has become active, it shall reset its sending keyboard state and queue an input synchronization event for the next InputPDU. On receipt of an input synchronization event within an InputPDU, an ASCE shall reset its receiving keyboard state for the issuing ASCE. + +## **8.7 Remote sharing** + +In some application sharing scenarios (e.g., remote working and/or help desk support), it is useful for sharing of applications and/or windows to be initiated remotely – that is, applications running on the local terminal are shared not by a local end-user or programmatic action, but rather as a result of a request from a peer ASCE. This is referred to as remote sharing. + +When an ASCE wishes to initiate remote sharing on a peer ASCE, it shall send a RemoteSharePDU with action request remote share and an encrypted password to the peer ASCE in the manner described in Table 6-3. The content of the RemoteSharePDU is shown in Table 8-37. + +On receipt of a request remote share RemoteSharePDU, an ASCE utilizes a purely local mechanism (such as interacting with the local end-user) to determine whether to allow remote sharing from the requesting ASCE and/or to validate the supplied password. If it determines to accept the remote share request, it responds with a confirm remote share RemoteSharePDU to the requesting ASCE and shares those local applications and/or windows that are eligible for remote sharing. The particular list of local applications and/or windows that are eligible for remote sharing is a local matter. For example, an ASCE may offer configuration options, whereby end-users can restrict the list of remote sharable applications and/or windows by class, by name or by requesting ASCE. + +If the ASCE determines not to accept the remote share request, it responds with a deny remote share RemoteSharePDU to the requesting ASCE, indicating why the remote share attempt was denied. Values are defined for the following denial cases: + +- The requesting ASCE supplied an invalid password. +- The receiving ASCE does not support remote sharing or does not have remote sharing enabled. + +- The receiving ASCE has already executed a remote share. That is, its defined remote sharable applications and/or windows are already shared. +- The receiving ASCE has requested a remote share to a third ASCE. + +**Table 8-37 – RemoteSharePDU** + +| Parameter | Description | +|------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| action | This parameter identifies the particular RemoteSharePDU action. The allowable values are as follows:
  • • Request remote share.
  • • Confirm remote share.
  • • Deny remote share.
| +| additionalData | This parameter provides optional additional data for specific actions:
  • • For the request remote share action, this parameter shall be the MCS user ID of the sending ASCE. This allows receiving ASCEs to implement remote share security on a per-remote ASCE basis.
  • • For the deny remote share action, this parameter provides a reason code for the denial, as follows:
    • – Incorrect password.
    • – Remote share not enabled/supported.
    • – Remote share in operation (incoming).
    • – Remote share in operation (outgoing).
| +| encryptedPassword | This parameter is only present for a request remote share message, where it is an X.509 protected simple authentication password without optional timestamp or optional random number. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +## 8.8 Fonts + +An ASCE sends font information to all ASCEs within the conference by sending a FontPDU in the manner described in Table 6-3. The content of the FontPDU is shown in Table 8-38. + +Font attribute information provides information on those fonts meeting the requirements of the AS protocol for which the sending ASCE is prepared to receive text and extended text orders (see clause 8.16.11 and clause 8.16.12). + +An ASCE may send a FontPDU during ASCE synchronization to allow other active ASCEs to perform font matching, which is a prerequisite for the sending of text and extended text orders within the AS session. See clause 8.6 for further information on synchronization. An ASCE need not send FontPDUs where it does not support allowable local fonts (see clause 8.8.1) and/or where it does not support text and extended text orders. + +Where an ASCE does not match a particular font and that font is then used locally by an application executing on the local terminal that is shared into the conference, the ASCE cannot send a text or extended text order referencing that font. However, it can send an UpdatePDU (bitmap) ASPDU containing the bits from the local terminal display area corresponding to the text bounds, which should result in an equivalent shadow window visual appearance on peer ASCEs. + +For example, the current ASCE protocol only allows advertising of fonts where some or all of the codepoints have glyphs in the full or core AS protocol code page (see clause 8.8.1) and the text and extended text order codepoint lists assume a single-byte code page. This precludes the advertising of double-byte fonts or the sending of text or extended text orders for such fonts. However, where such fonts are in use for text drawing within shared applications at one or more ASCEs within a conference, the ASCEs can use suitable UpdatePDU (bitmap) ASPDUs to achieve the same shadow window visual appearance on peer ASCEs. + +**Table 8-38 – FontPDU** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| entrySize | This parameter specifies the size in octets of a font attribute in the fontList parameter (see below). This parameter is only allowable for legacy mode FontPDUs. | +| fontList | This parameter is a list of font attributes. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +A receiving ASCE shall treat the position of font attributes in the FontPDU as a zero-offset numeric identifier, referred to as the FontID, for subsequent use during font matching and when sending text and extended text orders. For example, where a FontPDU contains 6 font attributes, the receiving ASCE shall use FontIDs 0..5 respectively to refer to the corresponding fonts at the sending ASCE. See Table 8-39. + +**Table 8-39 – Font attributes** + +| Parameter | Description | +|---------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| faceName | This parameter is a null-terminated T.50 text string specifying the face name of the font. | +| fontFlags |

This parameter is a set of bit flags indicating the characteristics of the font. Defined bit flag values are as follows.

  • • Fixed pitch If this flag is set, it indicates that the font is fixed pitch. If it is not set, the font is proportional.
  • • Fixed size If this flag is set, it indicates that the font is fixed size. If it is not set, the font is scalable.
| +| averageWidth | This parameter is the average character width in pixels of the font. This is the average of the character widths for codepoints 0x61 through 0x7A plus codepoint 0x20 (i.e., "a" through "z" plus "space" for the AS protocol code page – see clause 8.8.1), where the character width is the character cell for fixed pitch fonts and the sum of the A + B + C widths for proportional fonts. Where the font is scalable, this value shall be calculated for a font of size 100 × 100 pixels. | +| height | This parameter is the character cell height in pixels for this font. Where the font is scalable, this value shall be calculated for a font of size 100 × 100 pixels. | +| aspectX | This parameter specifies the horizontal aspect in pixels per inch of the device for which the font was designed. | + +**Table 8-39 – Font attributes** + +| Parameter | Description | +|----------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| aspectY | This parameter specifies the vertical aspect in pixels per inch of the device for which the font was designed. | +| signature1 |

This parameter is the signature checksum for the first codepoint group. It is calculated as the sum of the character widths for codepoints 0x30 through 0x5A plus 0x24 through 0x26 inclusive divided by 2 and truncated to 8 bits, where the character width is the character cell for fixed pitch fonts and the sum of the A + B + C widths for proportional fonts. Where the font is scalable, this value shall be calculated for a font of size 100 × 100 pixels. See clause 8.8.1 for further information on codepoints and code pages.

The combination of signature1 equals zero, signature2 equals zero and signature3 equals zero represents the special value NO_SIGNATURE.

| +| signature2 |

This parameter is the signature checksum for the second codepoint group. It is calculated as the sum of the character widths for codepoints 0x20 through 0x7E inclusive, less the sum of the character widths for the codepoints specified for calculation for the signature1 parameter, with the result divided by 2 and truncated to 8 bits, where the character width is the character cell for fixed pitch fonts and the sum of the A + B + C widths for proportional fonts. Where the font is scalable, this value shall be calculated for a font of size 100 × 100 pixels. See clause 8.8.1 for further information on codepoints and code pages.

The combination of signature1 equals zero, signature2 equals zero and signature3 equals zero represents the special value NO_SIGNATURE.

| +| signature3 |

This parameter is the signature checksum for the third codepoint group. It is calculated as the sum of the character widths for codepoints 0x00 to 0x1E plus 0x80 through 0xFF inclusive. Where the font is scalable, this value shall be calculated for a font of size 100 × 100 pixels. See clause 8.8.1 for further information on codepoints and code pages.

If the calculated values of the signature1, signature2 and signature3 parameters are all zero, then signature3 shall be set to zero.

The combination of signature1 equals zero, signature2 equals zero and signature3 equals zero represents the special value NO_SIGNATURE.

| +| codePage |

This parameter indicates which AS protocol code page codepoints are supported by this font. Allowable values are:

  • • All defined codepoints.
  • • Core codepoints only.

See clause 8.8.1 for further information on code points and code pages.

| +| nonStandardFontAttributes | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard font attributes allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.8.1 Code page + +The AS protocol code page consists of the ISO/IEC 8859-1 (Latin-1) code page with additional codepoints in the ranges 0x82-0x8C, 0x91-0x9C plus 0x9F. Codepoints in the ranges 0x00 through 0x1F, 0x7F through 0x81, 0x8D through 0x90, and codepoints 0x9D and 0x9E are not in [ISO/IEC 8859-1] and are not AS extensions – and are therefore not in the AS protocol code page. + +Codepoints in the range 0x20 through 0x7E are considered to be the core AS protocol code page codepoints. + +The AS protocol code page break character is codepoint 0x20. + +An ASCE shall only include font attributes in a FontPDU for fonts where all codepoints have glyphs in the AS protocol code page. Similarly, it shall only send codepoints in text or extended text orders where the corresponding glyphs are present in the AS protocol code page. + +Table 8-40 summarizes the supported codepoints in the AS protocol code page, indicating whether the codepoint is in [ISO/IEC 8859-1] or is an AS extension, and itemizes the corresponding Unicode [ISO/IEC 10646] code and name for each codepoint. + +**Table 8-40 – AS protocol code page** + +| Codepoint | ISO/IEC 8859-1 | Unicode code | Unicode name | +|-----------|----------------|--------------|-------------------| +| 0x0020 | √ | 0x0020 | SPACE | +| 0x0021 | √ | 0x0021 | EXCLAMATION MARK | +| 0x0022 | √ | 0x0022 | QUOTATION MARK | +| 0x0023 | √ | 0x0023 | NUMBER SIGN | +| 0x0024 | √ | 0x0024 | DOLLAR SIGN | +| 0x0025 | √ | 0x0025 | PERCENT SIGN | +| 0x0026 | √ | 0x0026 | AMPERSAND | +| 0x0027 | √ | 0x0027 | APOSTROPHE | +| 0x0028 | √ | 0x0028 | LEFT PARENTHESIS | +| 0x0029 | √ | 0x0029 | RIGHT PARENTHESIS | +| 0x002A | √ | 0x002A | ASTERISK | +| 0x002B | √ | 0x002B | PLUS SIGN | +| 0x002C | √ | 0x002C | COMMA | +| 0x002D | √ | 0x002D | HYPHEN-MINUS | +| 0x002E | √ | 0x002E | FULL STOP | +| 0x002F | √ | 0x002F | SOLIDUS | +| 0x0030 | √ | 0x0030 | DIGIT ZERO | +| 0x0031 | √ | 0x0031 | DIGIT ONE | +| 0x0032 | √ | 0x0032 | DIGIT TWO | +| 0x0033 | √ | 0x0033 | DIGIT THREE | +| 0x0034 | √ | 0x0034 | DIGIT FOUR | +| 0x0035 | √ | 0x0035 | DIGIT FIVE | +| 0x0036 | √ | 0x0036 | DIGIT SIX | +| 0x0037 | √ | 0x0037 | DIGIT SEVEN | +| 0x0038 | √ | 0x0038 | DIGIT EIGHT | +| 0x0039 | √ | 0x0039 | DIGIT NINE | +| 0x003A | √ | 0x003A | COLON | +| 0x003B | √ | 0x003B | SEMICOLON | + +**Table 8-40 – AS protocol code page** + +| Codepoint | ISO/IEC 8859-1 | Unicode code | Unicode name | +|------------------|-----------------------|---------------------|------------------------| +| 0x003C | √ | 0x003C | LESS-THAN SIGN | +| 0x003D | √ | 0x003D | EQUALS SIGN | +| 0x003E | √ | 0x003E | GREATER-THAN SIGN | +| 0x003F | √ | 0x003F | QUESTION MARK | +| 0x0040 | √ | 0x0040 | COMMERCIAL AT | +| 0x0041 | √ | 0x0041 | LATIN CAPITAL LETTER A | +| 0x0042 | √ | 0x0042 | LATIN CAPITAL LETTER B | +| 0x0043 | √ | 0x0043 | LATIN CAPITAL LETTER C | +| 0x0044 | √ | 0x0044 | LATIN CAPITAL LETTER D | +| 0x0045 | √ | 0x0045 | LATIN CAPITAL LETTER E | +| 0x0046 | √ | 0x0046 | LATIN CAPITAL LETTER F | +| 0x0047 | √ | 0x0047 | LATIN CAPITAL LETTER G | +| 0x0048 | √ | 0x0048 | LATIN CAPITAL LETTER H | +| 0x0049 | √ | 0x0049 | LATIN CAPITAL LETTER I | +| 0x004A | √ | 0x004A | LATIN CAPITAL LETTER J | +| 0x004B | √ | 0x004B | LATIN CAPITAL LETTER K | +| 0x004C | √ | 0x004C | LATIN CAPITAL LETTER L | +| 0x004D | √ | 0x004D | LATIN CAPITAL LETTER M | +| 0x004E | √ | 0x004E | LATIN CAPITAL LETTER N | +| 0x004F | √ | 0x004F | LATIN CAPITAL LETTER O | +| 0x0050 | √ | 0x0050 | LATIN CAPITAL LETTER P | +| 0x0051 | √ | 0x0051 | LATIN CAPITAL LETTER Q | +| 0x0052 | √ | 0x0052 | LATIN CAPITAL LETTER R | +| 0x0053 | √ | 0x0053 | LATIN CAPITAL LETTER S | +| 0x0054 | √ | 0x0054 | LATIN CAPITAL LETTER T | +| 0x0055 | √ | 0x0055 | LATIN CAPITAL LETTER U | +| 0x0056 | √ | 0x0056 | LATIN CAPITAL LETTER V | +| 0x0057 | √ | 0x0057 | LATIN CAPITAL LETTER W | +| 0x0058 | √ | 0x0058 | LATIN CAPITAL LETTER X | +| 0x0059 | √ | 0x0059 | LATIN CAPITAL LETTER Y | +| 0x005A | √ | 0x005A | LATIN CAPITAL LETTER Z | +| 0x005B | √ | 0x005B | LEFT SQUARE BRACKET | +| 0x005C | √ | 0x005C | REVERSE SOLIDUS | +| 0x005D | √ | 0x005D | RIGHT SQUARE BRACKET | +| 0x005E | √ | 0x005E | CIRCUMFLEX ACCENT | +| 0x005F | √ | 0x005F | LOW LINE | + +**Table 8-40 – AS protocol code page** + +| Codepoint | ISO/IEC 8859-1 | Unicode code | Unicode name | +|------------------|-----------------------|---------------------|--------------------------------| +| 0x0060 | √ | 0x0060 | GRAVE ACCENT | +| 0x0061 | √ | 0x0061 | LATIN SMALL LETTER A | +| 0x0062 | √ | 0x0062 | LATIN SMALL LETTER B | +| 0x0063 | √ | 0x0063 | LATIN SMALL LETTER C | +| 0x0064 | √ | 0x0064 | LATIN SMALL LETTER D | +| 0x0065 | √ | 0x0065 | LATIN SMALL LETTER E | +| 0x0066 | √ | 0x0066 | LATIN SMALL LETTER F | +| 0x0067 | √ | 0x0067 | LATIN SMALL LETTER G | +| 0x0068 | √ | 0x0068 | LATIN SMALL LETTER H | +| 0x0069 | √ | 0x0069 | LATIN SMALL LETTER I | +| 0x006A | √ | 0x006A | LATIN SMALL LETTER J | +| 0x006B | √ | 0x006B | LATIN SMALL LETTER K | +| 0x006C | √ | 0x006C | LATIN SMALL LETTER L | +| 0x006D | √ | 0x006D | LATIN SMALL LETTER M | +| 0x006E | √ | 0x006E | LATIN SMALL LETTER N | +| 0x006F | √ | 0x006F | LATIN SMALL LETTER O | +| 0x0070 | √ | 0x0070 | LATIN SMALL LETTER P | +| 0x0071 | √ | 0x0071 | LATIN SMALL LETTER Q | +| 0x0072 | √ | 0x0072 | LATIN SMALL LETTER R | +| 0x0073 | √ | 0x0073 | LATIN SMALL LETTER S | +| 0x0074 | √ | 0x0074 | LATIN SMALL LETTER T | +| 0x0075 | √ | 0x0075 | LATIN SMALL LETTER U | +| 0x0076 | √ | 0x0076 | LATIN SMALL LETTER V | +| 0x0077 | √ | 0x0077 | LATIN SMALL LETTER W | +| 0x0078 | √ | 0x0078 | LATIN SMALL LETTER X | +| 0x0079 | √ | 0x0079 | LATIN SMALL LETTER Y | +| 0x007A | √ | 0x007A | LATIN SMALL LETTER Z | +| 0x007B | √ | 0x007B | LEFT CURLY BRACKET | +| 0x007C | √ | 0x007C | VERTICAL LINE | +| 0x007D | √ | 0x007D | RIGHT CURLY BRACKET | +| 0x007E | √ | 0x007E | TILDE | +| 0x0082 | Extension | 0x201A | SINGLE LOW-9 QUOTATION MARK | +| 0x0083 | Extension | 0x0192 | LATIN SMALL LETTER F WITH HOOK | +| 0x0084 | Extension | 0x201E | DOUBLE LOW-9 QUOTATION MARK | +| 0x0085 | Extension | 0x2026 | HORIZONTAL ELLIPSIS | +| 0x0086 | Extension | 0x2020 | DAGGER | + +**Table 8-40 – AS protocol code page** + +| Codepoint | ISO/IEC 8859-1 | Unicode code | Unicode name | +|------------------|-----------------------|---------------------|--------------------------------------------| +| 0x0087 | Extension | 0x2021 | DOUBLE DAGGER | +| 0x0088 | Extension | 0x02C6 | MODIFIER LETTER CIRCUMFLEX ACCENT | +| 0x0089 | Extension | 0x2030 | PER MILLE SIGN | +| 0x008A | Extension | 0x0160 | LATIN CAPITAL LETTER S WITH CARON | +| 0x008B | Extension | 0x2039 | SINGLE LEFT-POINTING ANGLE QUOTATION MARK | +| 0x008C | Extension | 0x0152 | LATIN CAPITAL LIGATURE OE | +| 0x0091 | Extension | 0x2018 | LEFT SINGLE QUOTATION MARK | +| 0x0092 | Extension | 0x2019 | RIGHT SINGLE QUOTATION MARK | +| 0x0093 | Extension | 0x201C | LEFT DOUBLE QUOTATION MARK | +| 0x0094 | Extension | 0x201D | RIGHT DOUBLE QUOTATION MARK | +| 0x0095 | Extension | 0x2022 | BULLET | +| 0x0096 | Extension | 0x2013 | EN DASH | +| 0x0097 | Extension | 0x2014 | EM DASH | +| 0x0098 | Extension | 0x02DC | SMALL TILDE | +| 0x0099 | Extension | 0x2122 | TRADE MARK SIGN | +| 0x009A | Extension | 0x0161 | LATIN SMALL LETTER S WITH CARON | +| 0x009B | Extension | 0x203A | SINGLE RIGHT-POINTING ANGLE QUOTATION MARK | +| 0x009C | Extension | 0x0153 | LATIN SMALL LIGATURE OE | +| 0x009F | Extension | 0x0178 | LATIN CAPITAL LETTER Y WITH DIAERESIS | +| 0x00A0 | √ | 0x00A0 | NO-BREAK SPACE | +| 0x00A1 | √ | 0x00A1 | INVERTED EXCLAMATION MARK | +| 0x00A2 | √ | 0x00A2 | CENT SIGN | +| 0x00A3 | √ | 0x00A3 | POUND SIGN | +| 0x00A4 | √ | 0x00A4 | CURRENCY SIGN | +| 0x00A5 | √ | 0x00A5 | YEN SIGN | +| 0x00A6 | √ | 0x00A6 | BROKEN BAR | +| 0x00A7 | √ | 0x00A7 | SECTION SIGN | +| 0x00A8 | √ | 0x00A8 | DIAERESIS | +| 0x00A9 | √ | 0x00A9 | COPYRIGHT SIGN | +| 0x00AA | √ | 0x00AA | FEMININE ORDINAL INDICATOR | +| 0x00AB | √ | 0x00AB | LEFT-POINTING DOUBLE ANGLE QUOTATION MARK | +| 0x00AC | √ | 0x00AC | NOT SIGN | +| 0x00AD | √ | 0x00AD | SOFT HYPHEN | +| 0x00AE | √ | 0x00AE | REGISTERED SIGN | +| 0x00AF | √ | 0x00AF | MACRON | + +**Table 8-40 – AS protocol code page** + +| Codepoint | ISO/IEC 8859-1 | Unicode code | Unicode name | +|------------------|-----------------------|---------------------|-----------------------------------------------| +| 0x00B0 | √ | 0x00B0 | DEGREE SIGN | +| 0x00B1 | √ | 0x00B1 | PLUS-MINUS SIGN | +| 0x00B2 | √ | 0x00B2 | SUPERSCRIP TWO | +| 0x00B3 | √ | 0x00B3 | SUPERSCRIP THREE | +| 0x00B4 | √ | 0x00B4 | ACUTE ACCENT | +| 0x00B5 | √ | 0x00B5 | MICRO SIGN | +| 0x00B6 | √ | 0x00B6 | PILCROW SIGN | +| 0x00B7 | √ | 0x00B7 | MIDDLE DOT | +| 0x00B8 | √ | 0x00B8 | CEDILLA | +| 0x00B9 | √ | 0x00B9 | SUPERSCRIP ONE | +| 0x00BA | √ | 0x00BA | MASCULINE ORDINAL INDICATOR | +| 0x00BB | √ | 0x00BB | RIGHT-POINTING DOUBLE ANGLE
QUOTATION MARK | +| 0x00BC | √ | 0x00BC | VULGAR FRACTION ONE QUARTER | +| 0x00BD | √ | 0x00BD | VULGAR FRACTION ONE HALF | +| 0x00BE | √ | 0x00BE | VULGAR FRACTION THREE QUARTERS | +| 0x00BF | √ | 0x00BF | INVERTED QUESTION MARK | +| 0x00C0 | √ | 0x00C0 | LATIN CAPITAL LETTER A WITH GRAVE | +| 0x00C1 | √ | 0x00C1 | LATIN CAPITAL LETTER A WITH ACUTE | +| 0x00C2 | √ | 0x00C2 | LATIN CAPITAL LETTER A WITH
CIRCUMFLEX | +| 0x00C3 | √ | 0x00C3 | LATIN CAPITAL LETTER A WITH TILDE | +| 0x00C4 | √ | 0x00C4 | LATIN CAPITAL LETTER A WITH DIAERESIS | +| 0x00C5 | √ | 0x00C5 | LATIN CAPITAL LETTER A WITH RING ABOVE | +| 0x00C6 | √ | 0x00C6 | LATIN CAPITAL LETTER AE | +| 0x00C7 | √ | 0x00C7 | LATIN CAPITAL LETTER C WITH CEDILLA | +| 0x00C8 | √ | 0x00C8 | LATIN CAPITAL LETTER E WITH GRAVE | +| 0x00C9 | √ | 0x00C9 | LATIN CAPITAL LETTER E WITH ACUTE | +| 0x00CA | √ | 0x00CA | LATIN CAPITAL LETTER E WITH
CIRCUMFLEX | +| 0x00CB | √ | 0x00CB | LATIN CAPITAL LETTER E WITH DIAERESIS | +| 0x00CC | √ | 0x00CC | LATIN CAPITAL LETTER I WITH GRAVE | +| 0x00CD | √ | 0x00CD | LATIN CAPITAL LETTER I WITH ACUTE | +| 0x00CE | √ | 0x00CE | LATIN CAPITAL LETTER I WITH CIRCUMFLEX | +| 0x00CF | √ | 0x00CF | LATIN CAPITAL LETTER I WITH DIAERESIS | +| 0x00D0 | √ | 0x00D0 | LATIN CAPITAL LETTER ETH | +| 0x00D1 | √ | 0x00D1 | LATIN CAPITAL LETTER N WITH TILDE | + +**Table 8-40 – AS protocol code page** + +| Codepoint | ISO/IEC 8859-1 | Unicode code | Unicode name | +|------------------|-----------------------|---------------------|----------------------------------------| +| 0x00D2 | √ | 0x00D2 | LATIN CAPITAL LETTER O WITH GRAVE | +| 0x00D3 | √ | 0x00D3 | LATIN CAPITAL LETTER O WITH ACUTE | +| 0x00D4 | √ | 0x00D4 | LATIN CAPITAL LETTER O WITH CIRCUMFLEX | +| 0x00D5 | √ | 0x00D5 | LATIN CAPITAL LETTER O WITH TILDE | +| 0x00D6 | √ | 0x00D6 | LATIN CAPITAL LETTER O WITH DIAERESIS | +| 0x00D7 | √ | 0x00D7 | MULTIPLICATION SIGN | +| 0x00D8 | √ | 0x00D8 | LATIN CAPITAL LETTER O WITH STROKE | +| 0x00D9 | √ | 0x00D9 | LATIN CAPITAL LETTER U WITH GRAVE | +| 0x00DA | √ | 0x00DA | LATIN CAPITAL LETTER U WITH ACUTE | +| 0x00DB | √ | 0x00DB | LATIN CAPITAL LETTER U WITH CIRCUMFLEX | +| 0x00DC | √ | 0x00DC | LATIN CAPITAL LETTER U WITH DIAERESIS | +| 0x00DD | √ | 0x00DD | LATIN CAPITAL LETTER Y WITH ACUTE | +| 0x00DE | √ | 0x00DE | LATIN CAPITAL LETTER THORN | +| 0x00DF | √ | 0x00DF | LATIN SMALL LETTER SHARP S | +| 0x00E0 | √ | 0x00E0 | LATIN SMALL LETTER A WITH GRAVE | +| 0x00E1 | √ | 0x00E1 | LATIN SMALL LETTER A WITH ACUTE | +| 0x00E2 | √ | 0x00E2 | LATIN SMALL LETTER A WITH CIRCUMFLEX | +| 0x00E3 | √ | 0x00E3 | LATIN SMALL LETTER A WITH TILDE | +| 0x00E4 | √ | 0x00E4 | LATIN SMALL LETTER A WITH DIAERESIS | +| 0x00E5 | √ | 0x00E5 | LATIN SMALL LETTER A WITH RING ABOVE | +| 0x00E6 | √ | 0x00E6 | LATIN SMALL LETTER AE | +| 0x00E7 | √ | 0x00E7 | LATIN SMALL LETTER C WITH CEDILLA | +| 0x00E8 | √ | 0x00E8 | LATIN SMALL LETTER E WITH GRAVE | +| 0x00E9 | √ | 0x00E9 | LATIN SMALL LETTER E WITH ACUTE | +| 0x00EA | √ | 0x00EA | LATIN SMALL LETTER E WITH CIRCUMFLEX | +| 0x00EB | √ | 0x00EB | LATIN SMALL LETTER E WITH DIAERESIS | +| 0x00EC | √ | 0x00EC | LATIN SMALL LETTER I WITH GRAVE | +| 0x00ED | √ | 0x00ED | LATIN SMALL LETTER I WITH ACUTE | +| 0x00EE | √ | 0x00EE | LATIN SMALL LETTER I WITH CIRCUMFLEX | +| 0x00EF | √ | 0x00EF | LATIN SMALL LETTER I WITH DIAERESIS | +| 0x00F0 | √ | 0x00F0 | LATIN SMALL LETTER ETH | +| 0x00F1 | √ | 0x00F1 | LATIN SMALL LETTER N WITH TILDE | +| 0x00F2 | √ | 0x00F2 | LATIN SMALL LETTER O WITH GRAVE | +| 0x00F3 | √ | 0x00F3 | LATIN SMALL LETTER O WITH ACUTE | +| 0x00F4 | √ | 0x00F4 | LATIN SMALL LETTER O WITH CIRCUMFLEX | + +**Table 8-40 – AS protocol code page** + +| Codepoint | ISO/IEC 8859-1 | Unicode code | Unicode name | +|-----------|----------------|--------------|--------------------------------------| +| 0x00F5 | √ | 0x00F5 | LATIN SMALL LETTER O WITH TILDE | +| 0x00F6 | √ | 0x00F6 | LATIN SMALL LETTER O WITH DIAERESIS | +| 0x00F7 | √ | 0x00F7 | DIVISION SIGN | +| 0x00F8 | √ | 0x00F8 | LATIN SMALL LETTER O WITH STROKE | +| 0x00F9 | √ | 0x00F9 | LATIN SMALL LETTER U WITH GRAVE | +| 0x00FA | √ | 0x00FA | LATIN SMALL LETTER U WITH ACUTE | +| 0x00FB | √ | 0x00FB | LATIN SMALL LETTER U WITH CIRCUMFLEX | +| 0x00FC | √ | 0x00FC | LATIN SMALL LETTER U WITH DIAERESIS | +| 0x00FD | √ | 0x00FD | LATIN SMALL LETTER Y WITH ACUTE | +| 0x00FE | √ | 0x00FE | LATIN SMALL LETTER THORN | +| 0x00FF | √ | 0x00FF | LATIN SMALL LETTER Y WITH DIAERESIS | + +### 8.8.2 Font matching + +An ASCE shall use the font matching algorithm described in this clause to determine the current set of matched fonts for all active ASCEs (including itself). + +An ASCE shall determine the current set of matched fonts by comparing its local font information (i.e., the font attributes sent in its last FontPDU) against the font attributes provided by each other active ASCE, using the font match criteria described in Table 8-41 below. The match criteria are successively applied to the FontPDU parameters in a series of pairs of fonts and a font is added to the current set of matched fonts where a match is found at all other active ASCEs. This means that: + +- all active ASCEs have to match a font for it to be added to the current set of matched fonts; +- where one other active ASCE has not yet provided font attributes, there are no current matched fonts. + +The output of font matching is a mapping for each matched font between local and remote FontIDs for each other active ASCE. See clause 8.8 for further information on FontIDs. The matched font mappings are used as follows: + +- When sending text and extended text orders for a matched local font, the sending ASCE shall set the order FontID parameter to correspond to that font's FontID in the last sent FontPDU. +- When receiving text and extended text orders, the receiving ASCE shall map the FontID in the order to the local font that matched that FontID in the last received FontPDU from that ASCE. + +This mapping mechanism allows ASCEs to use a single set of FontIDs when sending text and extended text orders and places the responsibility on receiving ASCEs to map from FontID in the order to the local font on that terminal. + +Use of the same font matching algorithm ensures that each pair of ASCEs agree on an identical set of matched fonts and therefore generate an identical set of interoperable font mappings. + +Table 8-41 describes the minimum match criteria for each font parameter (corresponding to the parameter in the relevant FontPDU) considered during font matching, described in terms of the local font and one other remote font. + +Table 8-42 provides information on the allowable match types referenced in Table 8-41. An ASCE may or may not allow approximate matches, based on a purely local mechanism (such as local terminal configuration options). Where an ASCE does not allow approximate matches, only exact matches are permitted. Where an ASCE does allow approximate matches, it may do so on a per-match criteria basis (again dependent on local mechanisms), provided the corresponding negotiated capabilities allow that match type. + +A pair of fonts are defined to match where each of the font parameters requiring consideration in Table 8-41 are either all exact matches or meet the minimum match types defined in Table 8-41 (dependent on the ASCE's local approximate match configuration). For example, a particular ASCE may allow Delta X position but not code page approximate matches and, provided the negotiated capabilities allow for Delta X simulation, may then require that a pair of fonts are exact matches with respect to those considered parameters defined as requiring exact and code page minimum match types, but only require an approximate match for those considered parameters defined as requiring Delta X position minimum match types. + +**Table 8-41 – Font match criteria** + +| Parameter | Criteria | Match type | +|----------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------| +| faceName | The current and remote face names are identical. | Exact | +| fontFlags fixed pitch | Both fonts are fixed pitch OR both fonts are proportional (not fixed pitch). | Exact | +| codePage | Both fonts support all codepoints. | Exact | +| | Either the local or remote font only supports core codepoints. | Code page | +| fontFlags fixed size | Both fonts are fixed size OR both fonts are scalable (not fixed size). | Exact | +| | The local font is fixed size and the remote font is scalable. (Note 1) | Exact | +| averageWidth and height | Both fonts are fixed size and the averageWidth and height values are the same. (Note 2) | Exact | +| signature1, signature2 and signature3 | These criteria depend on the negotiated capabilities for font signature checking (i.e., in legacy mode on the negotiated Order.textFlags capability check font signatures bit flag; in base mode on the negotiated Order.checkFontSignatures capability). | | +| |
  • Font signature checking is enabled and the local and remote signature1, signature2 and signature3 values are the same.
| Exact | +| |
  • Font signature checking is enabled and the local and remote signature1 and signature2 values are the same.
| Delta X position | +| |
  • Font signature checking is enabled and the local and remote signature1, signature2 and signature3 values are not the same or either font has the special value NO_SIGNATURE.
  • Font signature checking is not enabled.
| Delta X position | + +**Table 8-41 – Font match criteria** + +| Parameter | Criteria | Match type | +|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------| +| aspectX and aspectY |

This criteria depend on the negotiated capabilities for font aspect checking (i.e., in legacy mode on the negotiated Order.textFlags capability check font aspect bit flag; in base mode on the negotiated Order.checkFontAspectFlag capability).

  • Font aspect checking is enabled and the local and remote aspectX and aspectY values are the same.
  • Font aspect checking is not enabled.
|

Exact

Delta X position

| +|

NOTE 1 – This assumes that an ASCE may match local fixed size fonts with remote scalable fonts and subsequently send text and extended text orders for that font, relying on receiving ASCEs to scale the text appropriately. It assumes that the inverse (i.e., matching scalable to fixed size and sending scalable) is not allowed.

NOTE 2 – If either font is scalable, these criteria are not considered.

| | | + +**Table 8-42 – Font match types** + +| Match type | Definition | +|------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Exact | Both font parameters under consideration must match exactly. | +| Code page | Where one or both of the code pages for the fonts under consideration only conforms to the core AS protocol code page, an ASCE may allow an approximate code page match. Where it does so, it shall subsequently restrict codepoints for that font in text and extended text orders to the core AS protocol code page. See clause 8.16.11 and clause 8.16.12 for further information on text and extended text orders. | +| Delta X position | Where positioning information for one or both of the fonts under consideration does not match exactly, an ASCE may allow an approximate Delta X position match. An ASCE shall only allow approximate Delta X matches where the negotiated capabilities allow for Delta X simulation (i.e., in legacy mode, the Order.textFlags allow DeltaX bit flag is set; in base mode, the Order.allowDeltaXFlag is TRUE) and shall thereafter simulate text X positioning information for the font using Delta X information in extended text orders. See clause 8.16.12 for further information on the extended text order and Delta X simulation. | + +### 8.8.3 Font aliasing + +Font matching acts on font attributes in FontPDUs. This enables an ASCE to perform font aliasing between fonts on the local terminal and the font attributes it sends in FontPDUs. This is a local ASCE implementation decision, but is particularly useful in the following scenarios: + +- The same (or very similar) fonts are available from a range of font suppliers for the local terminal (but use different face names). Here, an ASCE may map the local terminal fonts to a generic (supplier-independent) face name to increase the probability of font matching. +- The same (or very similar) fonts have different face names on different terminal types. Here an ASCE may map the local terminal fonts to a new (or additional) face name to increase the probability of font matching. + +For example, consider two ASCEs, where ASCE A supports Font\_Supplier\_A:Courier and Font\_Supplier\_B:Courier and ASCE B supports just Courier. If ASCE A provides font attributes for Font\_Supplier\_A:Courier, Font\_Supplier\_B:Courier and two aliased Couriers (corresponding to the two supplier-specific Couriers), then (provided other criteria match) both ASCEs are able to send orders for some or all local Courier text. + +## 8.9 Application management + +During an AS session, an ASCE may host one or more applications, each of which consists of a collection of hosted windows that are shared to peer active ASCEs. + +An ASCE shall notify peer active ASCEs when the number of hosted applications on the ASCE's local terminal changes, by sending an ApplicationPDU with action NotifyHostedApplications containing the new number of hosted applications to all ASCEs in the conference, in the manner indicated in Table 6-3. The content of the ApplicationPDU is shown in Table 8-43. + +This provides ongoing information to other active ASCEs on the number of applications hosted by this ASCE, which they may use to provide end-user information. Receiving ASCEs may use this ASPDU to monitor when remote ASCEs stop hosting applications – which may allow them to free up resources allocated for each other hosting ASCE. See clause 8.6 for further information on synchronization. + +An ASCE may start and stop hosting local applications at any time. This is purely a local matter and may be driven by the local end-user, local terminal behaviour and/or by conference initialization/termination. + +However, there are situations where it is useful to unhost remote applications. For example, where an ASCE is controlling hosted applications that were remote shared (see clause 8.7) or when the remote end-user is inexperienced. An ASCE may require a peer ASCE to unhost an application hosted on the peer ASCE's terminal by sending an ApplicationPDU with action UnhostApplication containing a windowID for the application to be unhosted in the manner indicated in Table 6-3. The supplied windowID should be a hosted\_window\_ID belonging to the application obtained from the most recent WindowListPDU sent by the hosting ASCE (see clause 8.10). An ASCE shall only send an ApplicationPDU with action UnhostApplication where the peer ASCE's General.remoteUnshareFlag capability is TRUE. + +On receipt of an ApplicationPDU with action UnhostApplication containing a windowID for an application hosted on the local terminal, an ASCE shall cease hosting the application concerned. + +**Table 8-43 – ApplicationPDU** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| action | This parameter identifies the particular ApplicationPDU action. Allowable values are NotifyHostedApplications or UnhostApplication. | +| numberApplications | This parameter indicates the number of applications hosted by the sending ASCE. This parameter is only valid where the action is NotifyHostedApplications. | +| windowID | This parameter specifies the top-most window owned by an application hosted on the peer ASCE to be unhosted. This parameter is only valid where the action is UnhostApplication. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +## 8.10 Window list management + +During an AS session, where an ASCE is hosting one or more windows that are shared to peer active ASCEs, it is managing a collection of windows, where those windows may be: + +- Hosted: Hosted windows are owned by an application hosted on the local terminal. For each hosted window, there is a corresponding shadow window on each peer ASCE. +- Shadow: Shadow windows are drawn by the ASCE and correspond to a hosted window on a particular peer ASCE. +- Local: Local windows are not shared – their application output is only visible on the local terminal. + +An ASCE is only required to track visible hosted windows. On certain terminals and/or terminal window managers, end-user or programmatic action may make application windows temporarily invisible (i.e., it is removed from the local terminal display) – for example, where a long-running system monitor application hides itself until an alarm event occurs that requires user action, whereupon it becomes visible again. Where a local hosted window becomes invisible, then an ASCE is not required to track the window and should not provide window list update information for the window (see below). + +Where a hosted window is obscured by local window(s) and the ASCE cannot obtain valid drawing information for that hosted window, the AS protocol requires that the hosting ASCE includes the obscuring local window(s) in the appropriate window list (see below) and that receiving ASCEs mark such obscured areas (in a locally determined manner) to indicate that the contents are not necessarily valid. + +Note that an ASCE need only track local windows when hosting and need only track those that obscure hosted windows and prevent it obtaining valid drawing information from those hosted windows. For example, an ASCE may display hosted and shadow windows in a dedicated terminal display area from which local windows are always excluded. Similarly, the particular terminal may not support local applications (and therefore windows) at all. Or, on certain terminal equipment, an ASCE may still be able to obtain valid drawing information from hosted windows where they are obscured by local windows. For these cases, an ASCE is not required to track local windows. + +An ASCE shall send a WindowListPDU to all ASCEs in the conference in the manner indicated in Table 6-3, when: + +- it starts or stops hosting windows; +- it is hosting windows and detects a change in the visible hosted window Z-order; +- it is hosting windows and one or more of its visible hosted window positions change; +- it is hosting windows and detects a local window Z-order or position change affecting the obscuring of visible hosted windows. + +This means that an ASCE only sends a WindowListPDU when it is hosting visible windows, or, as in the first case, when it is making the transition to or from hosting windows. The content of the WindowListPDU is shown in Table 8-44. The WindowListPDU contains information on two classes of windows: + +- The sending ASCE's view of all visible hosted or shadow windows within the conference. This view is (generally – but see below) common to all active ASCEs, since it includes hosted and shadow windows – and a window included in its list by one ASCE because it is hosted will be included in the corresponding lists by other ASCEs because it is shadowed. +- Any of the sending ASCE's local windows that obscure at least part of at least one visible hosted window. This information is owned and generated by a particular ASCE – since it relates to local windows, there is no overlap with similar information generated by peer ASCEs. + +The WindowListPDU contains a single window list, containing hosted and shadow windows and those local windows that meet the obscuring criteria, ordered such that the first window corresponds to the top (front-most) window and the last corresponds to the bottom (back-most) window in the local terminal Z-order. + +For each window in the window list, the ASCE provides Z-order information (implicitly by position in the list), position and size, ownership information and any appropriate qualifiers (such as whether the window is minimized). + +The AS protocol assumes that the information provided for hosted and shadow windows in the window list should normally be identical on all active ASCEs. It does not support independent Z-order, size/positioning or qualification (such as minimized) of shadow windows with respect to their corresponding hosted window. That is, where a hosted window's Z-order, size/position or qualification changes, then the AS protocol requires that an equivalent change is applied to corresponding shadow windows on all other active ASCEs. + +In practice, transient window list differences in hosted and shadow windows may occur, where the WindowListPDU reflecting a window list change has not yet been received and/or processed by other ASCEs. Much of the complexity in AS window list handling relates to the resolution of races in window list updates. The following description ignores the possibility of window list races and their resolution, which is covered in clause 8.10.1. + +On receipt of a WindowListPDU, an ASCE typically performs the following operations – although the specifics will depend on the local terminal environment. + +- It processes the WindowListPDU window list to: + - remove any old shadow windows; + - create any new shadow windows; + - update the size and/or position of windows that have been changed; + - adjust each hosted or shadow window's position in the Z-order on the local terminal to give the same relative Z-order as in the window list, taking care to maintain the correct Z-order relationship to local applications. +- It determines the new obscured window region – which determines which areas of shadow windows are valid for drawing – based on the sending ASCE's desktop size and any obscuring local windows in the WindowListPDU. + +An ASCE is required to apply window list changes as accurately as possible within the constraints of the local terminal environment. + +**Table 8-44 – WindowListPDU** + +| Parameter | Description | +|-------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| listTime | This parameter is the local ASCE time in milliseconds when this WindowListPDU was constructed. It is used in association with the listID parameter (see below) to resolve WindowListPDU races. See clause 8.10.1 below for further information. | +| listID | This parameter is the identifier assigned by the sending ASCE when this WindowListPDU was constructed. It is used in association with the listTime parameter (see above) to resolve WindowListPDU races. See clause 8.10.1 below for further information. | + +**Table 8-44 – WindowListPDU** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| windowAttributeList | This parameter is a list of window attributes (see Table 8-45) describing the window structure on the sending ASCE. The list is in Z-order, such that the first window is the top (front-most) and the last is the bottom (back-most) in the local terminal Z-order. | +| windowTitleList | This parameter is a list of window titles. The list is in Z-order, such that the first window is the top (front-most) and the last is the bottom (back-most) in the local terminal Z-order. Each title is either the special value NO_TITLE or is a T.50 text string describing the window. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +Many terminal window managers provide local facilities (such as a task list, task bar or icon tray) to allow end-users to activate or arrange windows. Such facilities are typically restricted to top-level windows – so that end-users can view the collection of windows that comprise the application as a whole. An ASCE may provide a title for a hosted window where the title would help end-users at peer ASCEs more readily identify the corresponding shadow window. It is recommended that an ASCE should only supply titles for hosted windows. Where the window is shadow or local, the ASCE should supply the special NO\_TITLE title string. + +The following requires that an ASCE assigns a unique local identifier for each hosted application (its hosted\_application\_ID) and a unique local identifier for each hosted window (its hosted\_window\_ID). + +**Table 8-45 – Window attributes** + +| Parameter | Description | +|--------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| windowID |

This parameter is the window identifier for this window.

  • Where the window is hosted, this parameter is the hosted_window_ID assigned by the sending ASCE.
  • Where the window is a shadow window, this parameter is the hosted_window_ID assigned by the owning ASCE (which was supplied in the last WindowListPDU for the corresponding hosted window).
| +| windowExtra |

This parameter supplies additional information for this window.

  • Where the window is hosted, this parameter is the hosted_application_ID assigned by the sending ASCE.
  • Where the window is a shadow window, this parameter is the MCS user ID of the hosting ASCE.
| +| windowOwner |

This parameter identifies the owning window for this window.

  • Where the window is hosted, this parameter is the hosted_window_ID of the owning window (i.e., the window that is the parent of this window in the local terminal window hierarchy). Note that where the window is hosted and the owning window is the desktop, this parameter shall be zero.
| + +**Table 8-45 – Window attributes** + +| Parameter | Description | +|------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| windowFlags |

This parameter is a set of bit flags qualifying the window. Defined bit flag values are as follows:

  • • Minimized (hosted windows only).
  • • Taggable (hosted windows only).
  • • Hosted.
  • • Shadow.
  • • Local.
  • • Always on top (hosted windows only).
  • • Window manager minimized (hosted windows only).
  • • Window manager invisible (hosted windows only).

See below for further information on the interpretation of window flags.

| +| windowLeft | This parameter is the left X coordinate of the window on the virtual desktop. For hosted and local windows, this parameter shall be the left X coordinate of the window (which may be outside the local desktop). | +| windowTop | This parameter is the top Y coordinate of the window on the virtual desktop. For hosted and local windows, this parameter shall be the top Y coordinate of the window (which may be outside the local desktop). | +| windowRight | This parameter is the right X coordinate of the window on the virtual desktop. For hosted and local windows, this parameter shall be the right X coordinate of the window (which may be outside the local desktop). | +| windowBottom | This parameter is the bottom Y coordinate of the window on the virtual desktop. For hosted and local windows, this parameter shall be the bottom Y coordinate of the window (which may be outside the local desktop). | +| nonStandardWindowAttributes | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard window attributes allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### Taggable + +End-users may have difficulty identifying which windows belong to which user in the conference. This is an issue where the end-user selects an application feature that will take effect on the hosting terminal (e.g., saving a file) and/or where multiple ASCEs within a conference are hosting applications, increasing the number of windows on the local terminal desktop. The window attribute taggable bit flag provides a mechanism whereby ASCEs may provide additional user interface information about hosted window location. + +An ASCE constructing a window list update should use the taggable bit flag to indicate whether hosted window(s) are eligible for tagging. It is recommended that sending ASCEs should only flag top-level windows as taggable and should not tag subsidiary and transient windows such as help hints or icon titles. The algorithm used to determine whether a window is taggable is purely a local matter, but it is recommended that ASCEs should mark as taggable only those windows that a user + +would perceive as constituting a distinct main application window or dialogue. An ASCE receiving a window list containing hosted windows with the taggable bit flag set may provide additional per-shadow window user interface cues (such as window tags and/or augmentation of the window title) identifying the node owning the corresponding hosted windows. + +### **Minimized windows** + +Certain terminals support the concept of minimization of windows, whereby a window is reduced to an icon or smaller window, which may then be displayed on the local terminal desktop or in a window owned by the terminal window manager (such as a window manager task list, task bar or icon tray). Where an application consists of multiple windows, then minimizing the application typically results in the application's top-level window(s) being minimized and other non-top-level windows being made invisible. + +Various styles of window minimization for hosted windows may be represented in window list updates using several of the windows attributes windowFlags – namely the minimized, window manager minimized and window manager invisible bit flags. + +- The minimized bit flag should be set by an ASCE when a hosted window is minimized – irrespective of the particular local minimization behaviour. +- The window manager minimized bit flag should be set by an ASCE when a hosted window is minimized to a local window manager window. This bit flag is typically applied to top-level windows. +- The window manager invisible bit flag should be set by an ASCE when a hosted window is made invisible as part of a local window manager minimization mechanism and where the window manager minimized bit flag is set for a parent window – i.e., where the main top-level hosted windows of an application are minimized to a local window manager window. It should not be set where the top-level hosted windows are minimized to the desktop. + +The use of these bit flags does not presume a particular local terminal window minimization behaviour or a particular local terminal window manager. Hosting ASCEs should set the allowable combination of bit flags that best expresses the characteristics of each minimized hosted window. Similarly, an ASCE processing a window list update containing hosted windows with one or more of these bit flags set should present the corresponding shadow windows in a manner that is appropriate to the local terminal and/or window manager minimization behaviour. This approach allows ASCEs to support the various minimization styles across multiple terminal types, with each ASCE presenting minimized shadow windows in a manner that is appropriate for the local terminal. + +### **Always on top** + +Certain terminal types support the concept of always on top windows, where such windows are normally displayed on top of all other windows. For example, always on top windows are often used for application suite tool bars. Where the local terminal supports always on top windows, there may be multiple windows which are treated as always as top, which are typically not part of the main terminal Z-order, but are rather managed as members of a separate always on top Z-order. Within this separate Z-order, always on top windows may change z-order with respect to each other, but are always on top of ordinary (i.e., not always on top) windows. + +Where always on top windows are supported on a particular terminal, the always on top bit flag should be set by an ASCE when a hosted window is treated locally as being always on top. This bit flag is typically applied to top-level hosted windows. ASCEs should also ensure that hosted windows marked as being always on top are higher than (i.e., in front of) windows that are not marked as such in the WindowListPDU list of windows. An ASCE processing a window list update containing hosted windows with the always on top bit flag set should attempt to make the corresponding shadow windows behave as always on top in the local terminal environment – which + +may be achieved using a similar facility in the local terminal environment or by manipulating the local Z-order to achieve the desired effect. + +### 8.10.1 Window list Z-order races + +As discussed above, each active ASCE within a conference maintains a window list for hosted, shadow and obscuring local windows. As multiple ASCEs may report window list updates to other ASCEs via the WindowListPDU, there is always the possibility of a race. Creation and deletion of windows and modifications to their size and position can only occur on the terminal hosting application owning the window concerned. In contrast, the position of a shared window in the Z-order can be altered on any terminal. + +If WindowListPDU window lists were simply applied by recipient ASCEs, this would result in convergence for window existence, position and size (since the update in the two colliding window lists would be orthogonal). However, naive application of Z-order changes can result in indefinite cross-over of window lists. Therefore, each ASCE maintains a window list identifier which it places in each WindowListPDU for Z-order race resolution. The identifier has three parts: + +- Sequence number: This is the current value of the sequence number as calculated by the sending ASCE (see below); this is held in bits 4-15 (i.e., the most significant three nibbles) of the listID parameter. +- Increment: This is the absolute amount by which the ASCE incremented the last seen sequence number to generate the new sequence number (see below); this is held in bits 0-3 (i.e., the least significant nibble) of the listID parameter. +- Tick: This is a tick in milliseconds, which is used to resolve races when the sequence number is identical; this is held in the listTime parameter. + +Each ASCE calculates the next identifier value by incrementing the last seen (i.e., sent or received) sequence number by the priority of the window list change to create a new sequence number. The new identifier is formed from the new sequence number, the increment (or priority) and the current local time in milliseconds. The recommended increment/priority values are as follows: + +- 0 ⇒ No change in Z-order but changes in window positions and/or sizes. +- 2 ⇒ Change in Z-order. +- 3 ⇒ Change in Z-order and change in window activation. +- 4 ⇒ Change in Z-order and change in window activation to special window (see clause 8.10.2). +- 5 ⇒ ASCE is no longer hosting. + +An increment of 5 should only be used when an ASCE stops hosting applications to force a timely removal of all corresponding shadow windows. + +Window list updates with a zero increment identifier are always applied as they do not affect the Z-order – and are therefore not subject to race resolution. However, window list identifiers with increments 2 through 5 require that the receiving ASCE check for Z-order races, which are resolved as follows: + +- The application of a received window list may cause changes already present in the local system (but not yet sent) to be lost. To minimize temporary inconsistencies and to minimize "rebounds", an ASCE should simulate such collisions by testing the received identifier against the (forecast) identifier that it would use in its next WindowListPDU. If there are pending window changes and the forecast identifier is later than the last identifier sent/received, then the received window list Z-order is not applied and the next window list (containing the pending changes) is duly sent. + +- If there are pending window changes and the forecast identifier is earlier than the last identifier sent/received, then the received window list Z-order is applied in the normal way, and the received identifier becomes the new identifier. Therefore, when the next window list is generated, it will be sent with an identifier that does not indicate a collision. +- If there are no pending window changes, the receiving ASCE compares the received identifier against the last identifier seen. There are two cases to consider: + - If the received identifier is later, the received window list Z-order is applied and the ASCE should schedule the conditional sending of a WindowListPDU to resend pending window changes. + - If the received identifier is earlier, then the received window list Z-order is discarded. + +Identifiers are compared using the following rule. Identifier A is later than Identifier B if: + +- A's sequence number > B's sequence number. +- A's sequence number = B's sequence number AND A's increment > B's increment. +- A's sequence number = B's sequence number AND A's increment = B's increment AND A's tick > B's tick. + +The final test for the final case (A's tick > B's tick) is used solely for race resolution – it does not imply any particular global time ordering. + +### 8.10.2 Implementation considerations + +On certain terminals, critical window manager error boxes (which appear to be windows) are actually drawn directly to the desktop window. An ASCE should handle this scenario by creating a virtual full screen shared window at the front of the Z-order. When peer ASCEs draw this virtual window, it will appear to be transparent for the areas that do not actually contain the error box, as updates will only be received for the actual error box area (most of the full screen window is not actually painted). When the error box is dismissed, the virtual window is deleted and everything returns to normal. + +Certain terminals support multiple screen sessions, where one or more screen sessions may be full-screen text-based sessions which may not be accessible to the ASCE. Where such a full-screen text session has control of the screen, the ASCE should add a virtual local full screen window at the front of the window list in the next WindowListPDU. This will be interpreted by peer ASCEs as a window that totally obscures all of the hosted windows, with the consequence that all shadow windows on recipient ASCEs will be within the obscured area. + +## 8.11 Window activation + +Many terminals and/or terminal window managers support a concept of window activation, whereby a particular local window is considered to be the active window – this is often referred to as the focus window or the input focus window. Where such a concept is supported, then the active window typically receives all local terminal pointing device and keyboard input. + +The AS protocol provides a window activation mechanism, whereby ASCEs may indicate changes in local window activation state and request changes in window activation state on other ASCEs. An ASCE is required to map the local terminal model of window activation onto the AS protocol model described in this clause. Where the local terminal does not support window activation, then the ASCE may perform a trivial mapping. + +Certain terminals and/or terminal window managers allow an application to capture the pointing device. Where this is the case, the capturing application window may not be the active window (e.g., the capturing application window may minimize itself or become invisible while the capture is in progress), but continues to receive the captured pointing device input. In the AS protocol, pointing device capture by a hosted window is treated as a special case (see below). + +AS window activation is tightly integrated with conductorship (if in effect within the conference) and with the conference AS control state. If an ASCE does not have the right to provide input to hosted or shadow windows, then it cannot change window activation state within the conference. See clause 8.19 for further information on conducted mode and clauses 8.12 and 8.13 for further information on control mechanisms. + +When the active window changes on a terminal within the conference, the new active window may be any one of: + +- a visible, invisible or capturing hosted window; +- a visible or invisible local window; +- a visible shadow window (ASCEs do not typically maintain invisible shadows). + +### 8.11.1 Activation indications and requests + +An ASCE shall monitor for two classes of activation events – referred to as indications and requests: + +- **Indications:** These are activation or capture state changes to a local or hosted window. These affect a window owned by an application on the local terminal and need to be propagated to peer ASCEs. When an ASCE detects an activation or capture state change affecting a local or hosted window, then it shall send a WindowActivationPDU with an appropriate indication (see below) to all ASCEs in the conference in the manner indicated in Table 6-3. The content of the WindowActivationPDU is shown in Table 8-46. +- **Requests:** These are activation changes to (or corresponding to) shadow windows. Some terminal window managers provide terminal-specific activation sequences, such as the ALT-TAB keyboard sequence cycling the window focus or window manager context menus that allow an end-user to switch focus to a specific window. Where the affected window is a shadow, the change should not be performed locally, but should be redirected to the ASCE that owns the corresponding hosted window. Where an ASCE recognizes such a change to a shadow window, it shall send a WindowActivationPDU with an appropriate request (see below) to the peer ASCE hosting the corresponding hosted window in the manner indicated in Table 6-3. + +Changes in the window activation status of hosted windows may result in window list changes. For example, a restore window request will normally result in the corresponding hosted window changing its position and/or Z-order. In contrast, a hosted window active indication may or may not result in a Z-order change, dependent on the hosting ASCE's terminal window manager focus policy. + +Changes in the window activation status of hosted windows do not cause changes in control. + +**Table 8-46 – WindowActivationPDU** + +| Parameter | Description | +|-------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| action |

This parameter identifies the particular WindowActivationPDU action. The defined range of actions is classified as either indications or requests. The allowable actions are as follows.

  • • Local window active (indication).
  • • Hosted window active (indication).
  • • Hosted window invisible (indication).
  • • Pointing device capture (indication).
  • • Activate window (request).
| + +**Table 8-46 – WindowActivationPDU** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| |
  • • Close window (request).
  • • Restore window (request).
  • • WindowManagerMenu (request).
  • • ActivationHelpKey (request).
  • • ActivationHelpIndexKey (request).
  • • ActivationHelpExtendedKey (request).
  • • See below for further information.
| +| activationID | This parameter is an identifier assigned by the sending ASCE. This parameter is only valid for indications where it is used in association with the defined indication priorities to resolve WindowActivationPDU races. The allowable range of values is 1..65534. See clause 8.11.2 below for further information. | +| activationWindow | This parameter provides an optional windowID for specific message types (see below). | +| activationPoint | For WindowManagerMenu requests, this is an optional parameter which may contain the position of the pointing device that caused the activation request. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +The following describes each WindowActivationPDU indication and request in further detail. Some of the required actions require that an ASCE be able to change the local terminal activation to no window having the local focus. On some terminal types, this may require that an ASCE maintain a special (invisible) no focus window. The following requires (as in clause 8.10) that an ASCE assigns a unique local identifier for each hosted window (its hosted\_window\_ID). + +- The local window active indication indicates that activation has changed to a local window on the sending ASCE. On receipt of a local window active indication, an ASCE shall change the local activation to no focus. +- The hosted window active indication indicates that activation has changed to a hosted window on the sending ASCE. The WindowActivationPDU activationWindow parameter contains the hosted\_window\_ID of the hosted window that is now active. On receipt of a hosted window active indication, an ASCE shall change the local activation to the local shadow window that corresponds to the indicated hosted window. +- The hosted window invisible indication indicates that activation has changed to an invisible hosted window on the sending ASCE. On receipt of a hosted window invisible indication, an ASCE shall change the local activation to no focus. +- The pointing device capture indication indicates that activation has changed to a hosted window that has captured the pointing device on the sending ASCE. Where the capturing hosted window is visible, the WindowActivationPDU activationWindow parameter contains the hosted\_window\_ID of the hosted window that has captured the pointing device. Where the capturing hosted window is not visible, the WindowActivationPDU activationWindow parameter is zero. On receipt of a pointing device capture indication with a hosted\_window\_ID, an ASCE shall change the local activation to the local shadow window that corresponds to the indicated hosted window. On receipt of a pointing device + +capture indication without a hosted\_window\_ID, an ASCE shall change the local activation to no focus. + +- The activate window request indicates that the sending ASCE has detected a local request to activate a shadow window. The WindowActivationPDU activationWindow parameter contains the hosted\_window\_ID of the hosted window on the peer ASCE that corresponds to the shadow window on the sending ASCE. On receipt of an activate window request, an ASCE shall activate the indicated hosted window. This should result in the receiving ASCE sending a subsequent WindowActivationPDU hosted window active indication for the hosted window. +- The close window request indicates that the sending ASCE has detected a local request to close a shadow window. The WindowActivationPDU activationWindow parameter contains the hosted\_window\_ID of the hosted window on the peer ASCE that corresponds to the shadow window on the sending ASCE. On receipt of a close window request, an ASCE shall close the indicated hosted window. This should result in the receiving ASCE sending a subsequent WindowActivationPDU indication for the local window that inherits activation. +- The restore window request indicates that the sending ASCE has detected a local request to restore a shadow window. The WindowActivationPDU activationWindow parameter contains the hosted\_window\_ID of the hosted window on the peer ASCE that corresponds to the shadow window on the sending ASCE. On receipt of a restore window request, an ASCE shall restore the indicated hosted window. This should result in the receiving ASCE sending a subsequent WindowActivationPDU hosted window active indication for the hosted window. +- The WindowManagerMenu request indicates that the sending ASCE has detected a local window manager menu-related operation corresponding to a minimized hosted window. The WindowActivationPDU activationWindow parameter contains the hosted\_window\_ID of the hosted window on the peer ASCE that corresponds to the shadow window on the sending ASCE and the activationPoint parameter optionally contains the x and y virtual desktop coordinates of the activation event (where it was initiated by the pointing device). On receipt of a WindowManagerMenu request, an ASCE shall submit a locally equivalent menu request for the indicated hosted window. +- The ActivationHelpKey, ActivationHelpIndexKey and ActivationHelpExtendedKey requests indicate that the sending ASCE has detected the corresponding local window manager help activation request for a shadow window. The WindowActivationPDU activationWindow parameter contains the hosted\_window\_ID of the hosted window on the peer ASCE that corresponds to the shadow window on the sending ASCE. On receipt of an ActivationHelpKey, ActivationHelpIndexKey or ActivationHelpExtendedKey request, an ASCE shall submit the locally equivalent help activation request for the indicated hosted window. + +An ASCE may only be able to detect certain activation requests on certain terminals and/or may only be able to process certain activation requests on certain terminals. For example, while terminal window manager activation is typically specific to the terminal and/or window manager type, the underlying concept is still sufficiently generic that an ASCE may detect the activation locally (in a manner specific to terminal window manager A) and a peer ASCE may process it (in a manner specific to terminal window manager B). In contrast, help activation keys (which switch to a specific class of help window) are less widely implemented and may only be available when both ASCEs (i.e., the ASCE with the shadow window and the peer ASCE with the corresponding hosted window) are executing on the same terminal type: + +- An ASCE shall only send a WindowActivationPDU with a WindowManagerMenu action, where the peer ASCE's window Activation.windowManagerMenuFlag capability is TRUE. + +- An ASCE shall only send a WindowActivationPDU with an ActivationHelpKey action, where the peer ASCE's window Activation.HelpKeyFlag capability is TRUE. +- An ASCE shall only send a WindowActivationPDU with an ActivationHelpIndexKey action, where the peer ASCE's window Activation.HelpExtendedKeyFlag capability is TRUE. +- An ASCE shall only send a WindowActivationPDU with an ActivationHelpExtendedKey action, where the peer ASCE's window Activation.HelpExtendedKeyFlag capability is TRUE. + +### 8.11.2 Activation identifiers and priorities + +The asynchronous nature of the AS activation protocol and the multiplicity of reasons for window activation state changes means that WindowActivationPDU collisions can occur. To detect these collisions, and hence maintain a consistent activation state across all active ASCEs in a conference, an ASCE shall place an activation identifier in all WindowActivationPDU indications. Identifiers are not required for WindowActivationPDU requests. + +Each ASCE in a conference maintains the last identifier sent or received in a WindowActivationPDU indication and increments the identifier (in the range 1..65534 with rollover) when sending each WindowActivationPDU indication: + +- If a received indication has an identifier less than the last sent or received identifier, it is discarded. +- If a received indication has an identifier equal to the last sent or received identifier, then the received indication's priority (see below) is compared to the priority of the last indication sent or received. If the priority of the received indication is less than or equal to the priority of the last sent or received indication, then the received indication is discarded. Otherwise, it is applied. +- If a received indication has an identifier greater than the last sent or received identifier, then it is applied. + +Table 8-47 describes the defined priorities for WindowActivationPDU indications. + +Identifiers are not used for WindowActivationPDU requests. This ensures that requests are applied independently of the indication identifier and priority handling. For example, where an ASCE sends an activate window request closely followed by a restore window request, then the second request is still applied, even though it may postdate a hosted window active indication from the receiving ASCE. + +**Table 8-47 – WindowActivationPDU indication priorities** + +| Indication | Priority | +|-------------------------|----------| +| Local window active | 1 | +| Hosted window active | 1 | +| Hosted window invisible | 1 | +| Pointing device capture | 2 | + +## 8.12 Control + +The conference control policy is a major determinant of application sharing usability. Experience shows that different control policies are applicable for different mixes of conference size and/or end-user experience. Therefore, the AS protocol does not mandate a particular control policy, but rather provides a set of core control mechanisms whereby ASCEs can implement a range of policies with (potentially) different characteristics – either sequentially or concurrently within the + +conference. The AS protocol also defines an additional mediated set of control mechanisms, which build upon the core control mechanisms described in this clause – see clause 8.13 for further information. + +The core AS control protocol is based on managing the right to provide input to hosted and/or shadow windows. In combination, these rights support the following core control modes: + +- **Detached:** In this mode, an ASCE: + - has the right to provide input to hosted windows; + - does not have the right to provide input to shadow windows; + - denies peer ASCEs the right to provide input to shadow windows that correspond to hosted windows on this ASCE. + +In practice, this allows an end-user to work with hosted applications without interference from other users – other users cannot supply input, activation changes or Z-order changes. +- **Cooperating:** In this mode, cooperating ASCEs within the conference serially acquire the right to provide input to hosted and shadow windows. At any point in time within the conference: + - one of the cooperating ASCEs can provide input to hosted and shadow windows – but only where other ASCEs are not detached (it is "in control"); + - the other cooperating ASCEs cannot provide input to hosted and shadow windows (they are "viewing"). + +Where an ASCE does not have the right to provide input to shadow windows – it is detached or cooperating/viewing – it may still provide information on pointing device movement to other ASCEs. Where an ASCE is in one of these control states and still provides this information, then other ASCEs may use the information to provide end-user feedback on the sending ASCE's pointing device activity – which may (for certain terminal types) substantially improve the remote end-users' perception of application sharing usability. Whether to provide the pointing device information when in these states, and how to present it on reception, is an ASCE implementation decision. See clause 8.18 for further information on input and pointing device events. + +The core AS control protocol does not specify an ASCE's or local terminal's rights to provide input to local windows when in either detached or cooperating modes. The particular policy adopted for local input rights will normally be determined by the particular characteristics of the local terminal. + +A conference may contain any mix of detached and cooperating ASCEs. ASCEs may freely move between cooperating and detached modes. In contrast, an ASCE can only be in control while it owns the control identifier. Each ASCE (whether cooperating or detached) tracks the current control identifier value within the conference and which ASCE currently holds the identifier. + +When an ASCE wishes to change the control state of the conference, it shall send a ControlPDU to all ASCEs in the conference in the manner indicated in Table 6-3. The content of the ControlPDU is shown in Table 8-48. + +**Table 8-48 – ControlPDU** + +| Parameter | Description | +|-------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| action |

This parameter identifies the particular ControlPDU action. The allowable actions are as follows.

  • • Request control.
  • • Grant control.
| + +**Table 8-48 – ControlPDU** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| |
  • • Detach.
  • • Cooperate.
See below for further information. | +| grantID | When the action parameter (see above) is grant control, this parameter specifies the MCS user ID of the ASCE being granted control – i.e., the new control identifier holder. | +| controlId | When the action parameter (see above) is grant control, this parameter is the control identifier assigned by the sending ASCE (see below). | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +When an ASCE wishes to obtain the control identifier, it shall send a request control ControlPDU to all ASCEs. This ASPDU is sent to all ASCEs (as are all ControlPDUs), so that, even though ASCEs track the ASCE currently holding the control identifier, they may detect situations where the control identifier is in the process of moving, or ASCEs holding the control identifier become inactive or leave the conference. + +On receipt of a request control ControlPDU, the ASCE holding the control identifier shall normally (but see below) send a grant control ControlPDU with the current control identifier value and the MCS user ID of the ASCE to which control is being granted to all ASCEs. This ASPDU is sent to all ASCEs so that all active ASCEs can track the current control identifier owner. Where an ASCE receives a request control ControlPDU when it is not holding the control identifier, it discards the ASPDU. + +There are some situations where unconditionally granting control may not be feasible. For example, on some terminal types, certain window manager functions (such as window dragging and/or sizing a local window) need to be explicitly terminated. But if the local ASCE is in cooperating mode and loses control (and hence loses the right to provide any input), it cannot complete the window manager operation, which leaves the operation active and the peer ASCE unable to complete it (because it cannot provide input to a local window on this ASCE). Where such a situation applies, an ASCE holding the control identifier may respond to a request control ControlPDU with a grant control ControlPDU with the current control identifier value and its own MCS User ID (i.e., it grants control to itself). As this is sent to all ASCEs, peer ASCEs, including the requester, treat it as an ordinary exchange of control, and the local ASCE retains control until the problematic operation is complete. + +Where an ASCE moves from cooperating to detached mode, it shall send a detach ControlPDU to all ASCEs. Similarly, where an ASCE moves from detached to cooperating mode, it shall send a cooperate ControlPDU to all ASCEs. Changing from cooperating to detached and vice versa is independent of ownership of the control identifier, and an ASCE holding the control identifier may move from cooperating to detached and back to cooperating mode without granting the control identifier if no peer ASCE requests it in the interim. + +### 8.12.1 Control identifiers + +The control identifier is a single value visible to all ASCEs within the conference, in the range 0..0x80000000. + +The initial control identifier value in a conference is always zero. The initial control identifier holder in a conference is the ASCE whose share identifier is the highest during ASCE activation (see clause 8.4). + +Thereafter, the control identifier value changes when an ASCE fails to receive a grant control response to a request control ControlPDU (within a reasonable time) or the control identifier holder becomes inactive or leaves the conference. Where either is the case, each detecting ASCE generates a new control identifier by incrementing the last known control identifier value by its MCS user ID and sends a grant control ControlPDU referencing itself as the owning ASCE (i.e., it advertises itself as the new control identifier holder). As multiple ASCEs may have detected the problem, this causes a control identifier race, which is won by the ASCE with the highest control identifier value. This creates a requirement that, at all times, if an ASCE receives a grant control ControlPDU with a higher control identifier value than the last control identifier value known to that ASCE, it shall recognize the higher value as the new control identifier value and the sending ASCE as the new control identifier holder. + +When an ASCE detects that a new ASCE has become active, it shall advertise its control state as follows: + +- If the ASCE is detached, it shall send a detach ControlPDU. +- If the ASCE is cooperating, it shall send a cooperate ControlPDU. +- If the ASCE holds the control identifier, it shall send a grant control ControlPDU referencing itself as the control identifier holder. + +The net of the above is that new joiners (and existing ASCEs) receive a refresh of each ASCE's control state plus information on the holder of the control identifier. See clause 8.4 for further information on ASCE activation and clause 8.6 for further information on synchronization. + +### **8.12.2 Interaction with conducted mode** + +Conducted mode operation (see clause 8.19) interacts with the AS control protocol as follows. + +When a conference enters conducted mode, all ASCEs shall send a cooperate ControlPDU, the ASCE on the conducting node shall send a request control ControlPDU and the ASCE holding the control identifier shall respond with a grant control ControlPDU. That is, all ASCEs enter cooperating mode and the conducting node acquires control – all other ASCEs are viewing. + +When Conductorship moves from one node to another, the new conducting node shall send a request control ControlPDU and the ASCE holding the control identifier (i.e., the previous conducting node) shall respond with a grant control ControlPDU. That is, control follows Conductorship. + +When the conference exits conducted mode, all ASCEs remain in cooperating mode and the last conducting node retains the control identifier, but ASCEs are once again free to request control and to switch between cooperating and detached modes. That is, the full AS control protocol is reinstated. + +## **8.13 Mediated control** + +The AS control protocol described in clause 8.12 provides a reasonable set of core control facilities. But it does not provide facilities such as the explicit passing of control to a specific ASCE or the ability for ASCEs to conditionally or unconditionally deny control requests. + +The AS mediated control protocol builds on the core control protocol to provide additional, more conditional, control facilities. The mediated control protocol is negotiable and is supported only where the negotiated capabilities enable it (i.e., in legacy mode, where the negotiated Control.controlFlags capability allow mediated control bit flag is set; in base mode, where the + +negotiated Control.mediatedControlFlag capability is TRUE). See clause 8.2.10 for further information on the control capability set. + +The mediated control protocol is implemented by a set of request and response messages, which build upon and mediate the effect of the core control protocol. Where the explanation of a mediated control protocol facility or message exchange in this clause requires that an ASCE initiate a core control protocol action and/or state change, then it is shown as follows: + +- Core (request control): The ASCE sends a request control ControlPDU to take control. +- Core (detach): The ASCE sends a detach ControlPDU to notify peer ASCEs that it has entered detached mode. + +When an ASCE wishes to send a mediated control request or response, it shall send a MediatedControlPDU to one or all ASCEs in the conference in the manner indicated in Table 6-3. The content of the MediatedControlPDU is shown in Table 8-49. + +**Table 8-49 – MediatedControlPDU** + +| Parameter | Description | +|----------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| action |

This parameter identifies the particular MediatedControlPDU action. The allowable actions are as follows:

  • • Take control request.
  • • Pass control request.
  • • Detach request.
  • • Confirm take response.
  • • Deny take response.
  • • Confirm detach response.
  • • Deny detach response.
  • • Deny pass response.
  • • Remote detach request.
  • • Deny remote detach response.

See below for further information.

| +| passControlFlag | This parameter indicates whether this MediatedControlPDU is part of a pass control sequence (see below). Where this parameter is part of a pass control sequence, the value is TRUE. On all other MediatedControlPDUs, this parameter shall be FALSE. | +| sendingReference | This parameter is a message reference used to correlate requests and responses. Where this MediatedControlPDU is a request (see the action parameter above), this is the reference allocated by the sending ASCE. Where this MediatedControlPDU is a response, this is the reference from the corresponding request. | +| originatorReference | This parameter is a message reference used to correlate requests and responses. Where this MediatedControlPDU is a take control request arising from a pass control request (see below), this parameter is the reference from the originating pass control request. Where this MediatedControlPDU is a response, this is the reference from the corresponding request. | + +**Table 8-49 – MediatedControlPDU** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| originatorID | This parameter is a MCS user ID. Where this MediatedControlPDU is a request, this is the MCS user ID of the sending ASCE. Where this MediatedControlPDU is a response, this is the MCS user ID from the corresponding request. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.13.1 Taking control + +When an ASCE wishes to take control using the mediated control protocol, its actions depend on the negotiated Control.controlInterest capability value. Where the negotiated value is always, the taking of control is unmediated and the ASCE initiates the core (request control) action to take control. See clause 8.2.10 for further information on the control capability set. Where the negotiated value is never, one or more peer ASCEs will not permit the taking of control and the ASCE cannot do so. Where the negotiated value is confirm, one or more peer ASCEs require that the taking of control requires confirmation by those peer ASCEs and the ASCE sends a take control request MediatedControlPDU to all ASCEs. + +On receipt of a take control request MediatedControlPDU, an ASCE's response depends on its local Control.controlInterest capability value (which should not be never – or the request should not have been issued). Where the local value is always, the ASCE responds with a confirm take response MediatedControlPDU to the requesting ASCE. Where the local value is confirm, the ASCE utilizes a purely local mechanism (such as interacting with the local end-user) to determine whether to allow the requesting ASCE to take control and then responds with either a confirm take response or deny take response MediatedControlPDU to the requesting ASCE accordingly. + +On receipt of confirm take response MediatedControlPDUs from all peer ASCEs (i.e., unanimous consent), the requesting ASCE initiates the core (request control) action to take control. However, if it receives one or more deny take response MediatedControlPDUs, then it abandons the attempt to take control. + +### 8.13.2 Passing control + +When an ASCE wishes to pass control to a specific peer ASCE using the mediated control protocol, its actions depend on its local Control.controlInterest capability value. Where the local value is never (i.e., this ASCE never gives up control), it should not attempt to pass control. Where the local value is always or confirm, it sends a pass control request MediatedControlPDU to the particular ASCE. + +On receipt of a pass control request MediatedControlPDU, an ASCE utilizes a purely local mechanism (such as interacting with the local end-user) to determine whether to accept control from the requesting ASCE. If it determines not to accept the pass request, it responds with deny pass response MediatedControlPDU to the requesting ASCE. If it determines to accept the pass request, it sends a take control request to the requesting ASCE, which should in turn result in receipt of a confirm take response MediatedControlPDUs from the requesting ASCE, whereupon it can initiate the core (request control) action to take control. + +Note that the take control request MediatedControlPDU is here sent to a single peer ASCE in response to a pass control request MediatedControlPDU, whereas in clause 8.13.1 above, it is sent to all peer ASCEs to conditionally take control. To distinguish between the two cases, all + +MediatedControlPDUs used as part of the pass control sequence (i.e., pass control request, take control request to one ASCE and deny pass response) have the passControlFlag parameter set to TRUE – it is FALSE in all other MediatedControlPDUs. + +### 8.13.3 Detaching + +When an ASCE wishes to detach using the mediated control protocol, its actions depend on the negotiated Control.detachInterest capability value. Where the negotiated value is always, detaching is unmediated and the ASCE initiates the core (detach) action to detach. Where the negotiated value is never, one or more peer ASCEs will not permit ASCEs to detach and the ASCE cannot do so. Where the negotiated value is confirm, one or more peer ASCEs require that detaching requires confirmation by those peer ASCEs and the ASCE sends a detach request MediatedControlPDU to all ASCEs. + +On receipt of a detach request MediatedControlPDU, an ASCE's response depends on its local Control.detachInterest capability value (which should not be never – or the detach request should not have been issued). Where the local value is always, the ASCE responds with a confirm detach response MediatedControlPDU to the requesting ASCE. Where the local value is confirm, the ASCE utilizes a purely local mechanism (such as interacting with the local end-user) to determine whether to allow the requesting ASCE to take control and then responds with either a confirm detach response or deny detach response MediatedControlPDU to the requesting ASCE accordingly. + +On receipt of confirm detach response MediatedControlPDUs from all peer ASCEs (i.e., unanimous consent), the requesting ASCE initiates the core (detach) action to detach. However, if it receives one or more deny detach response MediatedControlPDUs, then it abandons the attempt to detach. + +### 8.13.4 Remote detach + +When an ASCE wishes to detach a peer ASCE, its actions depend on the Control.remoteDetachFlag capability value for the peer ASCE. Where the value is FALSE, the peer ASCE does not allow remote detach and the ASCE abandons the attempt. Where the value is TRUE, the ASCE sends a remote detach request MediatedControlPDU to the particular ASCE. + +On receipt of a remote detach request MediatedControlPDU, an ASCE attempts to start the detach process described in clause 8.13.3. If it cannot initiate the detach attempt (because one or more peer ASCEs will not permit ASCEs to detach), it responds with a deny remote detach response MediatedControlPDU to the requesting ASCE. If it can initiate the detach attempt, then it proceeds as in clause 8.13.3. + +MediatedControlPDUs are either sent to all peer ASCEs or to specific peer ASCEs depending on the message type. Table 8-50 summarizes the sending characteristics for MediatedControlPDU requests and responses. + +**Table 8-50 – MediatedControlPDU MCS channels** + +| Request/response | Target | +|-----------------------------|-----------| +| Take control request (Note) | All ASCEs | +| Take control request (Note) | Peer ASCE | +| Pass control request | Peer ASCE | +| Detach request | All ASCEs | +| Confirm take response | Peer ASCE | +| Deny take response | Peer ASCE | +| Confirm detach response | Peer ASCE | + +**Table 8-50 – MediatedControlPDU MCS channels** + +| Request/response | Target | +|-----------------------------------------------------------------------------------------------------------------------------------------|-----------| +| Deny detach response | Peer ASCE | +| Deny pass response | Peer ASCE | +| Remote detach request | Peer ASCE | +| Deny remote detach response | Peer ASCE | +| NOTE – The two take control request variants are used in taking and passing control respectively (see clauses 8.13.1 and 8.13.2 above). | | + +## 8.14 Pointers + +When the local pointer shape changes, or when an application programmatically changes the local pointer position, an ASCE shall send information about the local pointer shape and/or position to all ASCEs within the conference by sending PointerPDUs in the manner indicated in Table 6-3. + +PointerPDUs supplying a new pointer shape (as opposed to updating the pointer position or referencing a previously cached pointer) are one of the following three types: + +- A pre-defined system pointer value, which is either the null pointer or the default pointer. The null pointer should be sent when the local pointer is not displayed. The default pointer should be sent when the local pointer is not over a hosted window or not captured by a hosted window. +- A monochrome pointer definition. This monochrome pointer may be used where a default pointer is not appropriate (see above), a local pointer is visible and colour pointer support has been disabled during capabilities negotiation. +- A colour pointer definition. This colour pointer may be used where a default pointer is not appropriate (see above), a local pointer is visible and colour pointer support has been enabled during capabilities negotiation. + +How an ASCE displays received pointer information is dependent on the current control state and conductorship (see clauses 8.12, 8.13 and 8.19), the current pointer position and the display capabilities of the local terminal. For example, a receiving ASCE might: + +- display the local pointer shape when cooperating and in control; +- display the pointer corresponding to the hosting ASCE when cooperating and viewing; +- display a modified version of one or more hosting ASCE's pointers when detached and the particular pointer(s) are over the corresponding shadow windows. + +### 8.14.1 System pointers + +When the local pointer becomes invisible (i.e., it is not displayed on the local terminal), an ASCE shall send a PointerPDU (system) with a systemPointerType of pointerNull to all other ASCEs within the conference. On receipt of a PointerPDU (system) with a systemPointerType of pointerNull, an ASCE shall set its current colour pointer for that host to a special null pointer. + +When the local pointer is not over a hosted window or not captured by a hosted window, an ASCE shall send a PointerPDU (system) with a systemPointerType of pointerDefault to all other ASCEs within the conference. On receipt of a PointerPDU (system) with a systemPointerType of pointerDefault, an ASCE shall set its current colour pointer for that host to a special default pointer. + +For both cases, while the receiving ASCE is required to track the current pointer for each other hosting ASCE, how it displays that pointer is a local matter. See Table 8-51. + +**Table 8-51 – PointerPDU (system)** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| systemPointerType | This parameter identifies the pointer to be used. The allowable values are pointerDefault or pointerNull. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.14.2 Monochrome pointers + +An ASCE is not required to support colour pointers (see clause 8.14.3) and may represent all non-system pointers as monochrome pointers (even where they are displayed locally in colour), provided it can implement a suitable local conversion. However, colour pointers are widely used on common terminals, and providing monochrome-only pointer support may result in a significant reduction in user acceptability. + +Where the local pointer changes to a pointer that is, or may be represented as, a monochrome pointer, an ASCE shall send a PointerPDU (mono) containing the new pointer's monochrome pointer definition. A receiving ASCE is only required to remember the last monochrome pointer definition from each other hosting ASCE which then becomes the current monochrome pointer for that host. + +While a receiving ASCE is required to track the current monochrome pointer for each other hosting ASCE, how it displays that pointer is a local matter. + +Monochrome pointers are not cached. A sending ASCE is required to send a new PointerPDU (mono) for each monochrome pointer change and a receiving ASCE is only required to remember the last monochrome pointer definition from each other hosting ASCE. + +Monochrome pointer data represents the pointer as a pair of monochrome AND and XOR masks, where the pointer can be drawn by ANDing the AND mask and then XORing the XOR mask to the display, allowing for the hot spot (see below). This is a common representation, which can be readily mapped to standard local functions on most common terminal types. + +Both masks are a series of monochrome pixel rows (i.e., 1 bit-per-pixel), where row zero starts at the highest pixel Y coordinate. That is, row 0 starts at (top, left). Within a row, pixel values are packed into octets, starting from the left-most pixel. Each octet contains eight pixels, with the leftmost pixel in the most significant bit. Each row of pointer data is padded to a two-octet boundary. + +The monochrome pointer hot spot defines a point within the pointer, which corresponds to the position on the display where the pointer should be drawn. For example, if the monochrome pointer hot spot is at point (3,4) within the pointer and the local pointer position is at point (50,50), then the (top, left) pixel (i.e., 0,0) of the pointer definition is drawn at (47,46) and the hot spot pixel is drawn at (50,50). See Table 8-52. + +**Table 8-52 – PointerPDU (mono)** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| hotSpotX | This parameter is the pointer hot spot X coordinate in pixels relative to (top, left) of the pointer definition. | +| hotSpotY | This parameter is the pointer hot spot Y coordinate in pixels relative to (top, left) of the pointer definition. | +| width | This parameter is the width of the pointer in pixels. | +| height | This parameter is the height of the pointer in pixels. | +| monoPointer | This is a monochrome pointer definition, consisting of a 1 bits-per-pixel XOR mask, followed by a 1 bits-per-pixel AND mask. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.14.3 Colour pointers + +Colour pointer support is optional. An ASCE may only send PointerPDU (colour) and PointerPDU (cached) ASPDUs where the negotiated `Pointer.colorPointerFlag` capability is TRUE. Where colour pointers are not supported, an ASCE is required to send all colour pointer changes as monochrome pointers (see clause 8.14.2). It is recommended that ASCEs support colour pointers. + +Colour pointers may be cached, depending on the result of pointer capabilities negotiation. If an ASCE supports colour pointer caching, it shall set its advertised `Pointer.pointerCacheSize` capability to the number of cached colour pointer entries it is prepared to support for each other hosting ASCE (see clause 8.2.11). + +Where colour pointers are supported and colour pointer caching is enabled after capabilities negotiation (i.e., the negotiated `Pointer.pointerCacheSize` is greater than one), a sending ASCE may allocate a colour pointer definition to a specific pointer cache entry on receiving ASCEs using a PointerPDU (colour) and then subsequently reuse that cached entry by sending a PointerPDU (cached) referencing that entry. It is the sending ASCE's responsibility to manage the colour pointer cache entry space. + +On receipt of a PointerPDU (colour) from a particular hosting ASCE referencing a colour pointer cache entry, an ASCE shall place the colour pointer definition in the cache entry for that host and set the supplied colour pointer definition as the current colour pointer for that host. On receipt of PointerPDU (cached) from a particular hosting ASCE referencing a colour pointer cache entry, an ASCE shall set the referenced cached colour pointer definition as the current colour pointer for that host. + +Where colour pointer caching is disabled, an ASCE shall not send the PointerPDU (cached) ASPDU and may only send information on local pointer changes via a series of PointerPDUs (colour). A receiving ASCE with colour pointer caching disabled is only required to remember the last colour pointer definition from each other hosting ASCE which is always the current colour pointer for that host. + +While a receiving ASCE is required to track the current colour pointer for each other hosting ASCE, how it displays that pointer is a local matter. + +Colour pointer data represents the pointer as a series of rows, where row zero starts at the lowest pixel Y coordinate. That is, row 0 starts at (bottom, left). Within a row, pixel values are packed into octets, starting from the left-most pixel. For the 1 bits-per-pixel AND mask data, each octet contains + +eight pixels, with the leftmost pixel in the most significant bit. For the 24 bits-per-pixel XOR mask data, each octet triplet contains one pixel of RGB colour information. + +Colour pointer data represents the pointer as a pair of AND and XOR masks, where the pointer can be drawn by ANDing the AND mask and then XORing the XOR mask to the display, allowing for the hot spot (see below). The AND mask is monochrome and the XOR mask is colour. This is a common representation, which can be readily mapped to standard local functions on most common terminal types. + +The AND mask is a series of monochrome pixel rows (i.e., 1 bit-per-pixel), where row zero starts at the highest pixel Y coordinate. That is, row 0 starts at (top, left). Within a row, pixel values are packed into octets, starting from the left-most pixel. Each octet contains eight pixels, with the left-most pixel in the most significant bit. Each row of pointer data is padded to a two-octet boundary. + +The XOR mask is 24 bits-per-pixel, where row zero starts at the highest pixel Y coordinate. That is, row 0 starts at (top, left). Within a row, each triplet of octets contains one pixel of RGB colour information. Within an RGB triplet, the first octet is a blue value in the range 0..255, the second octet is a green value in the range 0..255 and the third octet is a red value in the range 0..255. Octets are tightly packed – there are no pad octets between adjacent RGB values. Each row of pointer data is padded to a four-octet boundary. + +The colour pointer hot spot defines a point within the pointer, which corresponds to the position on the display where the pointer should be drawn. For example, if the colour pointer hot spot is at point (3,4) within the pointer and the local pointer position is at point (50,50), then the (top, left) pixel (i.e., 0,0) of the pointer definition is drawn at (47,46) and the hot spot pixel is drawn at (50,50). See Tables 8-53 and 8-54. + +**Table 8-53 – PointerPDU (colour)** + +| Parameter | Description | +|------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| cacheIndex | This parameter specifies the pointer cache entry to use for this pointer. Allowable values are in the range zero to one less than the negotiated Pointer.pointerCacheSize capability value. See clause 8.2.11 for further information on the pointer capability set. | +| hotSpotX | This parameter is the pointer hot spot X coordinate in pixels relative to (top, left) of the pointer definition. | +| hotSpotY | This parameter is the pointer hot spot Y coordinate in pixels relative to (top, left) of the pointer definition. | +| width | This parameter is the width of the pointer in pixels. | +| height | This parameter is the height of the pointer in pixels. | +| colorPointer | This is the colour pointer definition, consisting of a 24 bits-per-pixel XOR mask, followed by a 1 bit-per-pixel AND mask. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +**Table 8-54 – PointerPDU (cached)** + +| Parameter | Description | +|------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| cacheIndex | This parameter specifies which cached pointer to use. Allowable values are in the range zero to one less than the negotiated Pointer.pointerCacheSize capability value. See clause 8.2.11 for further information on the pointer capability set. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.14.4 Pointer position updates + +Normally, pointer position information is conveyed by input events driven by user pointing device activity. See clause 8.18 for further information on pointing device movement. However, some terminals allow applications to programmatically update the local pointer position. + +On such terminals, where an application programmatically updates the local pointer position, an ASCE shall send a PointerPDU (PointerPosition) containing the new virtual desktop pointer position. On receipt of a PointerPDU (PointerPosition) containing a new pointer position, a receiving ASCE updates the current pointer position for that host. + +While a receiving ASCE is required to track the current pointer position for each other hosting ASCE, how it processes that pointer position information is a local matter. See Table 8-55. + +**Table 8-55 – PointerPDU (PointerPosition)** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| pointerX | This parameter is the X virtual desktop coordinate of the new pointer position. | +| pointerY | This parameter is the Y virtual desktop coordinate of the new pointer position. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +## 8.15 Palette updates + +An ASCE sends palette updates to all ASCEs within the conference by sending an UpdatePDU containing a palette in the manner indicated in Table 6-3. The content of the UpdatePDU containing a palette is shown in Table 8-56. + +For example, if a local application changes a local palette and then draws a bitmap with respect to that palette, then the ASCE shall ensure that it sends a palette UpdatePDU before the bitmap UpdatePDU containing that bitmap data. Whenever an ASCE sends a new palette, it shall ensure that all hosted windows on its local terminal are redrawn, to ensure that receiving ASCEs can redraw any already received areas of the hosted windows with reference to the new palette. + +The AS protocol supports colour depths of 1, 4 and 8 bits-per-pixel (see clause 8.2.4). An ASCE shall not send palette updates where the sendingBitsPerPixel is 1. For this case, the AS protocol defines palette indices 0 and 1 as colour values black and white respectively. + +A palette contains 16 or 256 RGB colour values. The arrangement of colour values in the palette is significant and represents a sequence of palette indices from 0..15 or 0..255, depending on the sendingBitsPerPixel. In the base mode of the AS protocol, the palette may also contain optional colour accuracy information. + +On receipt of an UpdatePDU containing a palette, an ASCE shall use that palette to interpret subsequent bitmap data pixel values. For example, in incoming bitmap data at 8 bits-per-pixel, the receiving ASCE interprets a bitmap pixel containing the value 25 as referencing the 26th (allowing for indexing from zero) colour value in the last received palette from the sending ASCE. It shall not use the palette to interpret cached bitmap pixel values – which should be interpreted using the appropriate cached ColorTable (see clause 8.16.10). + +**Table 8-56 – UpdatePDU (palette)** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| palette | This parameter is a list of colour values constituting the palette. In the base mode of the AS protocol, the palette may also contain optional colour accuracy information. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +## 8.16 Order updates + +An ASCE sends order updates to all ASCEs within the conference by sending an UpdatePDU containing orders in the manner indicated in Table 6-3. The content of the UpdatePDU containing order updates is shown in Table 8-57. + +**Table 8-57 – UpdatePDU (orders)** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| orderList | This parameter is a list of orders. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +UpdatePDU orders may be of the following two types: + +- Primary orders (see Table 8-58): Primary orders are drawing orders that may result in output on remote ASCEs, subject to ASCE clipping, window order and/or presentation. +- Secondary orders (see Table 8-59): Secondary orders provide ancillary information for subsequent use by primary orders. For example, secondary orders are used to populate remote ASCE bitmap and ColorTable caches prior to cache references by subsequent primary orders. + +A single UpdatePDU containing orders may contain any mix of primary and secondary orders. + +**Table 8-58 – Primary orders** + +| Order | Reference | +|-----------------------------|----------------| +| Destination Blt | See Table 8-65 | +| Pattern Blt | See Table 8-66 | +| Screen Blt | See Table 8-67 | +| Memory Blt | See Table 8-70 | +| Memory three-way Blt | See Table 8-71 | +| Text | See Table 8-72 | +| Extended text | See Table 8-73 | +| Frame | See Table 8-74 | +| Rectangle | See Table 8-75 | +| Opaque rectangle | See Table 8-76 | +| Line | See Table 8-77 | +| Desktop save | See Table 8-78 | +| Desktop origin | See Table 8-79 | + +**Table 8-59 – Secondary orders** + +| Order | Reference | +|------------------------------------|----------------| +| Cache bitmap (compressed) | See Table 8-68 | +| Cache bitmap (uncompressed) | See Table 8-68 | +| Cache ColorTable | See Table 8-69 | +| Color space | See Table 8-80 | + +### 8.16.1 Primary orders + +Primary orders shall contain the primary order header. The legacy mode primary order header (see Table 8-60) contains explicit order encoding information, whereas the base mode primary order header (see Table 8-61) does not. See clause 8.16.3 for further information on order encoding. + +An ASCE shall only send an UpdatePDU containing primary orders where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., in legacy mode, the negotiated Order.orderFlags capability does not have the cannot receive orders bit flag set; in base mode, the negotiated Order.receiveOrdersFlag capability is TRUE) and where the corresponding order is supported (i.e., in legacy mode, the corresponding negotiated Order.ordersupport capability entry is non-zero; in base mode, the order's corresponding negotiated order level capability is non-zero). There may also be further order-specific restrictions, which are documented, where applicable, in the description of the particular primary order. + +An ASCE may supply bounds coordinates on primary orders. Bounds coordinates define a clipping rectangle for the order on which they are present. Where bounds coordinates are supplied on an order (after any required order decoding), the receiving ASCE shall draw the order clipped to the bounds and the virtual desktop. If bounds coordinates are not supplied on an order (after any required order decoding), the receiving ASCE shall not clip the order, other than to the virtual desktop. Where bounds coordinates are supplied (prior to order encoding) in the legacy mode of the AS protocol, the ASCE should set the bounds control flag in the order header control flags. + +**Table 8-60 – Primary order header (legacy mode)** + +| Parameter | Description | +|----------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| controlFlags | This parameter indicates the order encoding options applicable to the order that follows. See Table 8-63 for further information on order header control flags. | +| orderType (optional) | This parameter is present where the controlFlags parameter has the type change flag set. Where present, it specifies the type of order that follows. See Table 8-58 for a summary of allowable values. | +| encodingFlags | This parameter is 1..3 octets that indicate the number of encodable parameters that are present in the order. See Table 8-64 for further information on the number of encodable parameters that are allowable per primary order. | +| boundsFlags (optional)

v |

This parameter is present where the controlFlags parameter has the bounds flag set. Where present, it is a set of bit flags indicating which bounds coordinates are present in the bounds parameter (see below) and in which format, subject to bounds coordinates encoding. Defined bit flag values are as follows:

  • • Absolute left bounds coordinate present.
  • • Absolute top bounds coordinate present.
  • • Absolute right bounds coordinate present.
  • • Absolute bottom bounds coordinate present.
  • • Delta left bounds coordinate present.
  • • Delta top bounds coordinate present.
  • • Delta right bounds coordinate present.
  • • Delta bottom bounds coordinate present.

See clause 8.16.3.2 for further information on bounds coordinates encoding.

| +| bounds (optional) | This parameter is a set of zero to four absolute or delta bounds coordinates, depending on the bit flags set in the boundsFlags parameter (see above). | + +**Table 8-61 – Primary order header (base mode)** + +| Parameter | Description | +|--------------------------|-------------------------------------------------------------------------------| +| bounds (optional) | This parameter is a set of zero to four absolute or delta bounds coordinates. | + +### 8.16.2 Secondary orders + +In the legacy mode of the AS protocol, secondary orders shall contain the secondary order header described in Table 8-62. In the base mode of the AS protocol, secondary orders do not contain an explicit header. + +An ASCE shall only send an UpdatePDU containing secondary orders where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., in legacy mode, the negotiated Order.orderFlags capability does not have the cannot receive orders bit flag set; in base mode, the negotiated Order.receiveOrdersFlag capability is TRUE) and, in base mode, where the corresponding order is supported (i.e., the order's corresponding negotiated order level capability is + +non-zero). There may also be further order-specific restrictions, which are documented, where applicable in the description of the particular secondary order. + +**Table 8-62 – Secondary order header (legacy mode)** + +| Parameter | Description | +|---------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| controlFlags | This parameter indicates the order encoding options applicable to the order that follows. See Table 8-63 for further information on order header control flags. | +| extraFlags | This parameter is a set of bit flags indicating whether the order that follows is primary or secondary. The only defined bit flag value is secondary, which shall be set. | + +### 8.16.3 Order encoding + +The AS protocol uses order encoding to minimize the number of parameters within an order based on difference comparisons with previous orders. There are a number of defined order encoding methods, which, where applicable and where applied, shall be serially applied in the following order: + +- 1) Type encoding: See clause 8.16.3.1. +- 2) Bounds coordinates encoding: See clause 8.16.3.2. +- 3) Parameter encoding: See clause 8.16.3.3. +- 4) Coordinate encoding: See clause 8.16.3.4. + +Order encoding may only be applied to primary orders (i.e., secondary orders are not encoded). In the legacy mode of the AS protocol, order encoding information is conveyed via the controlFlags, encodingFlags and boundsFlags in the primary order header (see Table 8-60). In the base mode of the AS protocol, order encoding information is implicitly conveyed by the presence or absence of optional order parameters. + +Both modes require that sending and receiving ASCEs monitor the order stream sent in UpdatePDU (orders) ASPDUs to maintain an encoding state and potentially multiple decoding states (when receiving orders from multiple hosting ASCEs), such that sending ASCEs may omit unchanged, or may supply deltas for small changes in, order parameters, while receiving ASCEs can correctly reconstruct the original unencoded order stream. + +In the legacy mode of the AS protocol, all orders contain an initial set of control flags, which indicates how the rest of the order should be interpreted. See Table 8-63 for further information on the allowable control flags. For legacy mode primary orders, an ASCE shall always set the standard encoding control flag, shall not set the secondary control flag and may set any of the other allowable control flags as required by order encoding. For legacy mode secondary orders, an ASCE shall always set the standard encoding and secondary control flags and shall not set any of the other allowable control flags. + +**Table 8-63 – Order header control flags (legacy mode)** + +| Control flag | Description | +|--------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------| +| Standard encoding | This flag indicates that the order that follows conforms to the standard encoding for this Recommendation. This flag shall be set in all orders. | +| Secondary | This flag (if set) indicates that the order that follows is a secondary order. This flag shall only be set on secondary orders. | + +**Table 8-63 – Order header control flags (legacy mode)** + +| Control flag | Description | +|--------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Bounds | This flag (if set) indicates that the order that follows includes bounds. This flag shall only be set on primary orders. See clause 8.16.3.2 for further information on bounds coordinates encoding. | +| Type change | This flag (if set) indicates that the order that follows is of a different type to the previous order. This flag shall only be set in primary orders. See clause 8.16.3.1 for further information on type encoding. | +| Delta coordinates | This flag (if set) indicates that the order that follows uses delta coordinates (rather than absolute coordinates). This flag shall only be set in primary orders. See clause 8.16.3.4 for further information on coordinate encoding. | + +#### 8.16.3.1 Type encoding + +In the legacy mode of the AS protocol, where an order is the same type as the previous order, then an ASCE may clear the type change bit flag in the controlFlags parameter and omit the orderType parameter in the encoded order. Where a primary order is not of the same type as the previous order, an ASCE shall set the type change bit flag in the controlFlags parameter and supply the orderType parameter. + +Type encoding is applied for the continuous order stream and spans UpdatePDU (orders) ASPDUs. + +Type encoding is not supported in the base mode of the AS protocol. + +#### 8.16.3.2 Bounds coordinates encoding + +Where one or more of the bounds coordinates of an order are the same as the corresponding bounds coordinate in the previous order (which need not be of the same type), an ASCE may omit the unchanged bounds coordinates. Bounds order encoding is applied to individual bounds coordinates with respect to the same bounds coordinate in the previous order. For example, where both orderi and orderi+1 have a left bounds coordinate value of 100, then the left bound may be omitted in the encoded orderi+1. Conversely, where orderi's (left, top) bounds are (110, 100) and orderi+1's (left, top) bounds are (100, 110), neither the left nor top bounds coordinate may be omitted. + +Bounds coordinate encoding is applied for the continuous order stream and spans UpdatePDU (orders) ASPDUs. + +Where a bounds coordinate is changed from the previous order, it is then subject to coordinate encoding (see clause 8.16.3.4). This means that a particular order may omit some bounds coordinates, and may contain a mix of delta and absolute bounds coordinates for the remaining bounds coordinates. + +In the base mode of the AS protocol, the presence or absence of bounds coordinates and, where present, whether they are represented by absolute or delta coordinate bits is conveyed by the ASN.1 encoding (see clause 9). + +In the legacy mode of the AS protocol: + +- where some or all bounds coordinates are omitted, an ASCE shall clear both the corresponding absolute and delta bounds bit flags in the boundsFlag parameter in the primary order header (see Table 8-60); +- where one or more bounds coordinates are changed from the previous order and the change is in the range –128..+127 pixels, an ASCE may supply single octet delta coordinates for those bounds coordinates and set the corresponding delta coordinate bits in the boundsFlag parameter; + +- where one or more bounds coordinates are changed from the previous order and the change is not in the range $-128..+127$ pixels, an ASCE shall supply two-octet absolute coordinates for those bounds coordinates and set the corresponding absolute coordinate bits in the boundsFlag parameter. + +#### 8.16.3.3 Parameter encoding + +Where a parameter is the same as the corresponding parameter in the previous order of the same type, an ASCE may omit the unchanged parameter. For example, where both orderi and orderi+n (where n may be greater than one) are consecutive pattern Blt orders and both have a ROP3 parameter of 0xCC, then the ROP3 parameter may be omitted in the encoded orderi+n. See clause 8.16.5 for further information on pattern Blt orders and clause 8.16.20 for further information on three-way ROPs. + +Parameter encoding is applied with respect to the same parameter in orders of the same type across the continuous order stream and spans UpdatePDU (orders) ASPDUs. + +In the base mode of the AS protocol, the presence or absence of parameters is conveyed by the ASN.1 encoding (see clause 9). + +In the legacy mode of the AS protocol, the presence or absence of a particular parameter is indicated by the corresponding bit flag in the encodingFlags parameter in the primary order header (see Table 8-60). For each order: + +- the first parameter is parameter zero; +- the number of octets required for the encodingFlags parameter is (number of encodable parameters +7) div 8; +- the bit flag for parameter N is represented by encodingFlags octet (N div 8), bit flag (N mod 8), where the first encodingFlags octet is octet zero and the first bit within an octet is the least significant bit. + +Common parameters such as brushes and pens are encoded according to their constituent parameters. For example, the brush parameter in the pattern Blt order (see Table 8-66), which is documented as a single parameter (for the purposes of clarity), contributes five encodable parameters to the total of twelve encodable parameters for the pattern Blt order. Such grouped parameters are marked as (group) in the respective order descriptions. + +For example, in the parameter encoding for the pattern Blt order (see clause 8.16.5) + +- the foregroundColor parameter is parameter 6 and is represented by octet 0, bit 6; +- the brush hatch parameter is parameter 10 and is represented by octet 1, bit 2. + +Table 8-64 summarizes the number of encodable parameters per order. + +**Table 8-64 – Primary orders: Encodable parameters** + +| Order | Number of encodable parameters | Number of encodingFlags octets | Reference | +|---------------------|--------------------------------|--------------------------------|----------------| +| Destination Blt | 5 | 1 | See Table 8-65 | +| Pattern Blt | 12 | 2 | See Table 8-66 | +| Screen Blt | 7 | 1 | See Table 8-67 | +| Memory Blt | 9 | 2 | See Table 8-70 | +| Memory three-ay Blt | 17 | 3 | See Table 8-71 | +| Text | 14 | 2 | See Table 8-72 | + +**Table 8-64 – Primary orders: Encodable parameters** + +| Order | Number of encodable parameters | Number of encodingFlags octets | Reference | +|-------------------------|--------------------------------|--------------------------------|----------------| +| Extended text | 20 | 3 | See Table 8-73 | +| Frame | 14 | 2 | See Table 8-74 | +| Rectangle | 17 | 3 | See Table 8-75 | +| Opaque rectangle | 5 | 1 | See Table 8-76 | +| Line | 10 | 2 | See Table 8-77 | +| Desktop save | 6 | 1 | See Table 8-78 | +| Desktop origin | 2 | 1 | See Table 8-79 | + +#### 8.16.3.4 Coordinate encoding + +After the application of any parameter encoding (see clause 8.16.3.3), an ASCE may apply coordinate encoding to any remaining coordinate parameters. + +Where the change in coordinate parameters with respect to the same coordinate parameters in the previous order of the same type, is in the range $-128..+127$ pixels, an ASCE may supply single octet delta coordinates for coordinate parameters. + +In the legacy mode of the AS protocol, coordinate encoding requires that all not previously encoded coordinates in an order can be represented as delta coordinates. Therefore, where the change in one or more not previously encoded coordinates is outside the range $-128..+127$ pixels, an ASCE shall use two-octet absolute coordinates for all coordinate parameters. In the base mode of the AS protocol, there is no such restriction, and an ASCE may supply a mix of delta and absolute coordinates, depending solely on the change in a particular not previously encoded coordinate parameter with respect to the same parameter in the previous order of the same type. + +In the legacy mode of the AS protocol, an ASCE shall set or clear the delta coordinates bit flag in the controlFlags parameter, to indicate whether all coordinates are conveyed as delta or absolute coordinates. In the base mode of the AS protocol, the presence or absence of coordinates, and whether they are delta or absolute, is conveyed by the ASN.1 encoding (see clause 9). + +Coordinate encoding is applied with respect to (not previously encoded) coordinate parameters in an order with respect to the same coordinate parameters in the previous order of the same type across the continuous order stream and spans UpdatePDU (orders) ASPDUs. + +Coordinate parameters that are eligible for coordinate encoding are marked as (coordinate) in the order parameter descriptions and the grouped parameter definitions. + +### 8.16.4 Destination Blt + +An ASCE shall only send a destination Blt order where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., in legacy mode, the negotiated Order.orderFlags capability does not have the cannot receive orders bit flag set; in base mode the negotiated Order.receiveOrdersFlag capability is TRUE) and where the destination Blt order is supported (i.e., in legacy mode the corresponding negotiated Order.orderSupport capability entry is non-zero; in base mode, the negotiated Order.DestinationBltLevel capability is non-zero). + +An ASCE receiving the destination Blt order performs the ROP3 parameter raster operation on the destination rectangle on the virtual desktop, subject to any bounds clipping. See Table 8-65. + +**Table 8-65 – Destination Blt order** + +| Parameter | Description | +|--------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Primary order header | The primary order header is described in clause 8.16.1. | +| destLeft (coordinate) | This parameter is the left X virtual desktop coordinate of the destination rectangle for this destination Blt. | +| destTop (coordinate) | This parameter is the top Y virtual desktop coordinate of the destination rectangle for this destination Blt. | +| destWidth (coordinate) | This parameter is the width in pixels of the destination rectangle for this destination Blt. | +| destHeight (Coordinate) | This parameter is the height in pixels of the destination rectangle for this destination Blt. | +| ROP3 | This parameter is the three-way ROP to use for this destination Blt. For destination Blt orders, the three-way ROP shall reference a destination and shall not reference a source or pattern. See clause 8.16.20 for further information on three-way ROPs. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.16.5 Pattern Blt + +An ASCE shall only send a pattern Blt order where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., in legacy mode, the negotiated Order.orderFlags capability does not have the cannot receive orders bit flag set; in base mode, the negotiated Order.receiveOrdersFlag capability is TRUE) and where the pattern Blt order is supported (i.e., in legacy mode, the negotiated corresponding Order.orderSupport capability entry is non-zero; in base mode, the negotiated Order.PatternBltLevel capability is non-zero). + +An ASCE receiving the pattern Blt order performs the ROP3 parameter raster operation on the brush and the destination rectangle on the virtual desktop, subject to any bounds clipping. See Table 8-66. + +**Table 8-66 – Pattern Blt order** + +| Parameter | Description | +|--------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Primary order header | The primary order header is described in clause 8.16.1. | +| destLeft (coordinate) | This parameter is the left X virtual desktop coordinate of the destination rectangle for this pattern Blt. | +| destTop (coordinate) | This parameter is the top Y virtual desktop coordinate of the destination rectangle for this pattern Blt. | +| destWidth (coordinate) | This parameter is the width in pixels of the destination rectangle for this pattern Blt. | +| destHeight (coordinate) | This parameter is the height in pixels of the destination rectangle for this pattern Blt. | +| ROP3 | This parameter is the three-way ROP to use for this pattern Blt. For pattern Blt orders, the three-way ROP shall reference a pattern and shall not reference a source. See clause 8.16.20 for further information on three-way ROPs. | +| backgroundColor | This parameter is the background colour to use for this pattern Blt. | + +**Table 8-66 – Pattern Blt order** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| foregroundColor | This parameter is the foreground colour to use for this pattern Blt. | +| brush (group) | This parameter is the brush to use for this pattern Blt. See clause 8.16.22 for further information on brushes. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.16.6 Screen Blt + +An ASCE shall only send a screen Blt order where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., in legacy mode, the negotiated Order.orderFlags capability does not have the cannot receive orders bit flag set; in base mode, the negotiated Order.receiveOrdersFlag capability is TRUE) and where the screen Blt order is supported (i.e., in legacy mode, the corresponding negotiated Order.orderSupport capability entry is non-zero; in base mode, the negotiated Order.ScreenBltLevel capability is non-zero). + +An ASCE receiving the screen Blt order performs the ROP3 parameter raster operation on the source and destination rectangles on the virtual desktop, subject to any bounds clipping: + +- The source rectangle is defined by the sourceX, sourceY parameters and the destWidth, destHeight parameters. +- The destination rectangle is defined by the destLeft, destTop parameters and the destWidth, destHeight parameters. +- The destWidth and destHeight parameters define the width and height of both the source and destination rectangles. This precludes any stretching. +- The source may overlap the destination. + +See Table 8-67. + +**Table 8-67 – Screen Blt order** + +| Parameter | Description | +|--------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Primary order header | The primary order header is described in clause 8.16.1. | +| destLeft (coordinate) | This parameter is the left X virtual desktop coordinate of the destination rectangle for this screen Blt. | +| destTop (coordinate) | This parameter is the top Y virtual desktop coordinate of the destination rectangle for this screen Blt. | +| destWidth (coordinate) | This parameter is the width in pixels of the destination rectangle for this screen Blt. | +| destHeight (coordinate) | This parameter is the height in pixels of the destination rectangle for this screen Blt. | +| ROP3 | This parameter is the three-way ROP to use for this screen Blt. For screen Blt orders, the three-way ROP shall reference a source and shall not reference a pattern. See clause 8.16.20 for further information on three-way ROPs. | +| sourceX (coordinate) | This parameter is the source X virtual desktop coordinate for this screen Blt. | + +**Table 8-67 – Screen Blt order** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| sourceY (coordinate) | This parameter is the source Y virtual desktop coordinate for this screen Blt. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.16.7 Cache bitmap + +An ASCE shall only send a cache bitmap order where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., in legacy mode, the negotiated Order.orderFlags capability does not have the cannot receive orders bit flag set; in base mode, the negotiated Order.receiveOrdersFlag capability is TRUE) and either of the memory Blt or memory three-way Blt orders are supported (i.e., in legacy mode, the corresponding negotiated Order.orderSupport capability entries are non-zero; in base mode either of the negotiated Order.MemoryBltLevel or Order.MemoryThreeWayBltLevel capabilities are non-zero). In addition, in base mode the negotiated Order.CacheBitmapLevel capability shall be non-zero. + +The sending ASCE shall further ensure that the cache bitmap order parameters reflect the outcome of bitmap and bitmap cache capabilities negotiation (see clauses 8.2.4 and 8.2.7), namely that: + +- it shall only send a cache bitmap (compressed) order where the negotiated bitmap capability set values indicate that bitmap compression is supported; +- the bitmapBitsPerPixel parameter is equal to the negotiated sendingBitsPerPixel value; +- the cacheID value references a bitmap cache area where the negotiated value indicates at least one entry; +- the cacheIndex value within that bitmap cache area is less than the negotiated number of entries; +- the bitmap size (after any compression) fits into the negotiated maximum cell size for that bitmap cache area. + +The sending ASCE is responsible for allocating the cacheID and cacheIndex parameters and, therefore, for populating and updating the receiving ASCE's bitmap cache. This requires that hosting ASCEs track bitmap cache usage based on previously sent cache bitmap orders. + +An ASCE receiving a cache bitmap order from a particular hosting ASCE places the supplied bitmap into the cacheID bitmap cache area for that hosting ASCE at entry cacheIndex. The supplied bitmap replaces any existing cached bitmap in that slot. This requires that all active ASCEs maintain a separate bitmap cache for each other hosting ASCE. See Table 8-68. + +**Table 8-68 – Cache bitmap order** + +| Parameter | Description | +|-------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Secondary order header | The secondary order header is described in clause 8.16.2. | +| cacheID | This parameter indicates which bitmap cache should be used for this bitmap. Allowable values, depending on bitmap cache negotiation, are in the range 0..2. See clause 8.2.7 for further information on bitmap cache negotiation. | +| bitmapWidth | This parameter is the width in pixels of the bitmap. | + +**Table 8-68 – Cache bitmap order** + +| Parameter | Description | +|------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| bitmapHeight | This parameter is the height in pixels of the bitmap. | +| bitmapBitsPerPixel | This parameter is the bits-per-pixel of the bitmap data. This parameter shall be the same as the negotiated Bitmap.sendingBitsPerPixel capability value. See clause 8.2.4 for further information. | +| cacheIndex | This parameter indicates which cache entry to use within the particular cache indicated by the cacheID parameter (see above). Allowable values depend on the outcome of bitmap cache capabilities negotiation of cache cell sizes for each cache. See clause 8.2.7 for further information on bitmap cache negotiation. | +| bitmapData | This parameter is the bitmap data to cache. The bitmap may be uncompressed (see clause 8.17.1) or compressed (see clause 8.17.2). | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.16.8 Cache ColorTable + +An ASCE shall only send a cache ColorTable order where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., in legacy mode, the negotiated Order.orderFlags capability does not have the cannot receive orders bit flag set; in base mode, the negotiated Order.receiveOrdersFlag capability is TRUE) and either of the memory Blt or memory three-way Blt orders are supported (i.e., in legacy mode, the corresponding negotiated Order.orderSupport capability entries are non-zero; in base mode, either the negotiated Order.MemoryBltLevel or Order.MemoryThreeWayBltLevel capabilities are non-zero). In addition, in base mode the negotiated Order.CacheColorTableLevel capability shall be non-zero. + +The sending ASCE shall further ensure that the cache ColorTable order parameters reflect the outcome of bitmap and ColorTable cache capabilities negotiation (see clause 8.2.4 and clause 8.2.8), namely that: + +- The number of entries in the ColorTable is based on the negotiated sendingBitsPerPixel value as follows: +number of ColorTable entries = 2 to power of sendingBitsPerPixel +(This gives an allowable number of ColorTable entries of 16 or 256). +- The cacheIndex value within the ColorTable cache is less than the negotiated number of entries. + +An ASCE shall not send the cache ColorTable order where the Bitmap.sendingBitsPerPixel is 1. For this case, the AS protocol defines ColorTable indices 0 and 1 as colour values black and white, respectively. See clause 8.2.4 for further information on the bitmap capability set. + +The sending ASCE is responsible for allocating the cacheIndex parameter and, therefore, for populating and updating the receiving ASCE's ColorTable cache. This requires that hosting ASCEs track ColorTable cache usage at all other active ASCEs, based on previously sent cache ColorTable orders. + +An ASCE receiving the cache ColorTable order places the supplied ColorTable into its ColorTable cache area at entry cacheIndex. The supplied ColorTable replaces any existing cached ColorTable + +in that slot. This requires that all active ASCEs maintain a separate ColorTable cache for each other hosting ASCE. + +A ColorTable contains 16 or 256 RGB colour values. The arrangement of colour values in the ColorTable is significant and represents a sequence of ColorTable indices from 0..15 or 0..255, depending on the sendingBitsPerPixel. In the base mode of the AS protocol, the ColorTable may also contain optional colour accuracy information. See Table 8-69. + +**Table 8-69 – Cache ColorTable order** + +| Parameter | Description | +|-------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Secondary order header | The secondary order header is described in clause 8.16.2. | +| cacheIndex | This parameter indicates which cache entry to use within the ColorTable cache. Allowable values depend on the outcome of ColorTable cache capabilities negotiation of cache size. See clause 8.2.8 for further information on the ColorTable cache capability set. | +| colorTable | This parameter is a list of colour values comprising the ColorTable to be cached. In the base mode of the AS protocol, the ColorTable may also contain optional colour accuracy information. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.16.9 Memory Blt + +An ASCE shall only send a memory Blt order where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., in legacy mode, the negotiated Order.orderFlags capability does not have the cannot receive orders bit flag set; in base mode, the negotiated Order.receiveOrdersFlag capability is TRUE) and where the memory Blt order is supported (i.e., in legacy mode, the corresponding negotiated Order.orderSupport capability entry is non-zero; in base mode, the negotiated Order.MemoryBltLevel capability is non-zero). + +The sending ASCE shall ensure that the bitmapCacheID, bitmapCacheIndex and colorTableCacheIndex parameters refer to a bitmap and ColorTable previously cached using the cache bitmap and cache ColorTable orders. + +An ASCE receiving a memory Blt order performs the ROP3 parameter raster operation using the source rectangle in the cached bitmap and the destination rectangle on the virtual desktop, subject to any bounds clipping. + +- The source rectangle is defined by the sourceX, sourceY parameters and the destWidth, destHeight parameters. +- The destination rectangle is defined by the destLeft, destTop parameters and the destWidth, destHeight parameters. +- The destWidth and destHeight parameters define the width and height of both the source and destination rectangles. This precludes any stretching. +- The source rectangle is completely within the cached bitmap dimensions. The receiving ASCE does not need to perform clipping of the source rectangle against the cached bitmap dimensions. +- The cached bitmap bits shall be interpreted using the referenced cached ColorTable. + +See Table 8-70. + +**Table 8-70 – Memory Blt order** + +| Parameter | Description | +|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Primary order header | The primary order header is described in clause 8.16.1. | +| colorTableCacheIndex | This parameter specifies the cached ColorTable to use for this memory Blt. See clause 8.16.8 for further information on ColorTable caching.

For legacy mode memory Blt orders, this parameter and the bitmapCacheID parameter (see below) are both present where the appropriate bit flag is set in the encodingFlags parameter in the primary order header (Note). | +| bitmapCacheID | This parameter, when used in conjunction with the bitmapCacheIndex parameter (see below), specifies the cached bitmap to use for this memory Blt. See clause 8.16.7 for further information on bitmap caching.

For legacy mode memory Blt orders, this parameter and the colorTableCacheIndex parameter (see above) are both present where the appropriate bit flag is set in the encodingFlags parameter in the primary order header (Note). | +| destLeft (coordinate) | This parameter is the left X virtual desktop coordinate of the destination rectangle for this memory Blt. | +| destTop (coordinate) | This parameter is the top Y virtual desktop coordinate of the destination rectangle for this memory Blt. | +| destWidth (coordinate) | This parameter is the width in pixels of the destination rectangle for this memory Blt. | +| destHeight (coordinate) | This parameter is the height in pixels of the destination rectangle for this memory Blt. | +| ROP3 | This parameter is the three-way ROP to use for this memory Blt. For memory Blt orders, the three-way ROP shall reference a source and shall not reference a pattern. See clause 8.16.20 for further information on three-way ROPs. | +| sourceX (coordinate) | This parameter is the source X coordinate in the referenced cached bitmap for this memory Blt. | +| sourceY (coordinate) | This parameter is the source Y coordinate in the referenced cached bitmap for this memory Blt. | +| bitmapCacheIndex | This parameter, when used in conjunction with the bitmapCacheID parameter (see above), specifies the cached bitmap to use for this memory Blt. See clause 8.16.7 for further information on bitmap caching. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | +| NOTE – For legacy mode memory Blt orders, the colorTableCacheIndex and bitmapCacheID parameters are counted as one parameter in the primary order header encodingFlags. See clause 8.16.3.3 for further information. | | + +### **8.16.10 Memory three-way Blt** + +An ASCE shall only send a memory three-way Blt order where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., in legacy mode, the negotiated Order.orderFlags capability does not have the cannot receive orders bit flag set; in base mode, the negotiated Order.receiveOrdersFlag capability is TRUE) and where the memory three-way Blt order is + +supported (i.e., in legacy mode, the corresponding negotiated Order.orderSupport capability entry is non-zero; in base mode, the negotiated Order.MemoryThreeWayBltLevel capability is non-zero). + +The sending ASCE shall ensure that the bitmapCacheID, bitmapCacheIndex and colorTableCacheIndex parameters refer to a bitmap and ColorTable previously cached using the cache bitmap and cache ColorTable orders. + +An ASCE receiving a memory three-way Blt order performs the ROP3 parameter raster operation using the brush, the source rectangle in the cached bitmap and the destination rectangle on the virtual desktop, subject to any bounds clipping. + +- The source rectangle is defined by the sourceX, sourceY parameters and the destWidth, destHeight parameters. +- The destination rectangle is defined by the destLeft, destTop parameters and the destWidth, destHeight parameters. +- The destWidth and destHeight parameters define the width and height of both the source and destination rectangles. This precludes any stretching. +- The source rectangle is completely within the cached bitmap dimensions. The receiving ASCE does not need to perform clipping of the source rectangle against the cached bitmap dimensions. +- The cached bitmap bits shall be interpreted using the referenced cached ColorTable. + +See Table 8-71. + +**Table 8-71 – Memory three-way Blt order** + +| Parameter | Description | +|--------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Primary order header | The primary order header is described in clause 8.16.1. | +| colorTableCacheIndex | This parameter specifies the cached ColorTable to use for this memory three-way Blt. See clause 8.16.8 for further information on ColorTable caching.

For legacy mode memory three-way Blt orders, this parameter and the bitmapCacheID parameter (see below) are both present where the appropriate bit flag is set in the encodingFlags parameter in the primary order header (Note). | +| bitmapCacheID | This parameter, when used in conjunction with the bitmapCacheIndex parameter (see below), specifies the cached bitmap to use for this memory three-way Blt. See clause 8.16.7 for further information on bitmap caching.

For legacy mode memory three-way Blt orders, this parameter and the colorTableCacheIndex parameter (see above) are both present where the appropriate bit flag is set in the encodingFlags parameter in the primary order header (Note). | +| destLeft (coordinate) | This parameter is the left X virtual desktop coordinate of the destination rectangle for this memory three-way Blt. | +| destTop (coordinate) | This parameter is the top Y virtual desktop coordinate of the destination rectangle for this memory three-way Blt. | +| destWidth (coordinate) | This parameter is the width in pixels of the destination rectangle for this memory three-way Blt. | +| destHeight (coordinate) | This parameter is the height in pixels of the destination rectangle for this memory three-way Blt. | + +**Table 8-71 – Memory three-way Blt order** + +| Parameter | Description | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ROP3 | This parameter is the three-way ROP to use for this memory three-way Blt. For memory Blt orders, the three-way ROP shall reference a destination, source and pattern. See clause 8.16.20 for further information on three-way ROPs. | +| sourceX (coordinate) | This parameter is the source X coordinate in the referenced cached bitmap for this memory three-way Blt. | +| sourceY (coordinate) | This parameter is the source Y coordinate in the referenced cached bitmap for this memory three-way Blt. | +| backgroundColor | This parameter is the background colour to use for this memory three-way Blt. | +| foregroundColor | This parameter is the foreground colour to use for this memory three-way Blt. | +| brush (group) | This parameter is the brush to use for this memory three-way Blt. See clause 8.16.22 for further information on brushes. | +| bitmapCacheIndex | This parameter, when used in conjunction with the bitmapCacheID parameter (see above), specifies the cached bitmap to use for this memory three-way Blt. See clause 8.16.7 for further information on bitmap caching. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | +| NOTE – For legacy mode, memory three-way Blt orders, the colorTableCacheIndex and bitmapCacheID parameters are counted as one parameter in the primary order header encodingFlags. See clause 8.16.3.3 for further information. | | + +### 8.16.11 Text + +An ASCE shall only send a text order where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., in legacy mode, the negotiated Order.orderFlags capability does not have the cannot receive orders bit flag set; in base mode, the negotiated Order.receiveOrdersFlag capability is TRUE), where the text order is supported (i.e., in legacy mode, the corresponding negotiated Order.orderSupport capability entry is non-zero; in base mode, the negotiated Order.TextLevel capability is non-zero), the particular font has been matched and the codepoints fall within the font's specified codepoint range. + +The text order allows an ASCE to specify the text start Y position in terms of either the first character's baseline or the first character cell's top. It is recommended that ASCEs use baseline positioning wherever the capabilities allow, as it may be difficult on certain terminal types to accurately position scalable font text based solely on the first character cell (left, top) position. + +An ASCE shall only send text orders using baseline positioning where the negotiated capabilities indicate that baseline text start positioning is allowed (i.e., in legacy mode, the negotiated Order.textFlags capability baseline start bit flag is set; in base mode, the negotiated Order.baselineStartFlag capability is TRUE). Where that is the case, it shall set the order textFlags parameter baseline start bit flag, and set the order startX and startY as the position of the first character cell's (left, baseline) pixel. Otherwise, where the negotiated capabilities indicate that baseline text start positioning is not allowed, it shall clear the order textFlags parameter baseline start bit flag and set startX and startY as the position of the first character cell's (left, top) pixel. + +Certain terminal types allow applications to dynamically specify text attributes to fonts at drawing time, in addition to those attributes that are inherent to the font. For example, if a local terminal supports a Courier bold font, then it may allow its applications to draw using that font in association with an italic attribute to achieve an emulated "Courier bold italic" (which may be different in appearance to the actual Courier bold italic font that corresponds to the available Courier bold font). Where the local terminal supports dynamic text attributes in this manner, a sending ASCE may use the textFlags parameter italic, underline and StrikeOut bit flags and the fontWeight parameter (alone or in combination) to indicate that receiving ASCEs should apply the corresponding attributes to the drawn text. + +An ASCE receiving a text order draws the character codepoints on the virtual desktop, subject to any bounds clipping, as follows: + +- The characters are drawn in the foregroundColor. If the backMixMode is opaque, the character cell backgrounds are drawn in the backgroundColor. +- Where the order's textFlags parameter baseline start bit flag is set, startX and startY are the position of the first character cell's (left, baseline) pixel. Otherwise, startX and startY are the position of the first character cell's (left, top) pixel. +- The characters are positioned with any extraSpacing applied to all characters and any break spacing (equal to totalBreakSpacing divided by breakCount) applied to the break character. +- The characters are drawn in the local font that corresponds to the sending ASCE's FontID, subject to any additional attributes indicated by the textFlags and/or fontWeight parameters. See clause 8.8.2 for further information on fonts. +- If the local font is scalable, the characters are drawn at the supplied fontWidth and fontHeight. Otherwise, they are drawn at the width and height inherent in the font. +- The characters are drawn using the supplied fontWeight and as per the italic, underline and StrikeOut bit flags supplied in the textFlags parameter. + +See Table 8-72. + +**Table 8-72 – Text order** + +| Parameter | Description | +|-----------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Primary order header | The primary order header is described in clause 8.16.1. | +| backMixMode | This parameter is the background mix mode to use for this text order. See clause 8.16.24 for further information on background mix modes. | +| startX (coordinate) | This parameter is the start X virtual desktop coordinate for this text order. | +| startY (coordinate) | This parameter is the start Y virtual desktop coordinate for this text order. Where the baseline start bit flag is set in the textFlags parameter, this corresponds to the baseline pixel of the first character cell. Where the baseline start bit flag is not set in the textFlags parameter, this corresponds to the top pixel of the first character cell. | +| backgroundColor | This parameter is the background colour to use for this text order. | +| foregroundColor | This parameter is the foreground colour to use for this text order. | +| extraSpacing | This parameter specifies the additional spacing in pixels to be applied to individual characters for this text order. A value of zero indicates that no additional spacing is to be applied. | +| totalBreakSpacing | This parameter specifies the total of additional spacing in pixels to be applied to break characters for this text order. A value of zero indicates that no break spacing is to be applied. | + +**Table 8-72 – Text order** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| breakCount | This parameter specifies the number of break characters in this text order. A value of zero indicates either that no break spacing is to be applied or there are no break characters in this order. | +| fontHeight | For scalable fonts, this parameter is the height in pixels of the font to use for this text order. See clause 8.8 for further information. | +| fontWidth | For scalable fonts, this parameter is the average character width in pixels of the font to use for this text order. See clause 8.8 for further information. | +| fontWeight | This parameter indicates the weight of the font to use for this text order. The allowable values are 0..1000, which are interpreted as: light $\leq 400 <$ normal $\leq 700 <$ bold. See clause 8.8 for further information. | +| textFlags | This parameter is a set of bit flags indicating additional text characteristics for this text order. Defined bit flag values are as follows:
  • • Italic.
  • • Underline.
  • • StrikeOut.
  • • Baseline start.
| +| fontID | This parameter is the sending ASCE's FontID, determined through font negotiation, to use for this text order. See clause 8.8 for further information on font negotiation and font mapping. | +| codePointList | This parameter is a list of codepoints to use for this text order. The codepoints shall be in the AS protocol code page. See clause 8.8.1 for further information on codepoints and code pages. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.16.12 Extended text + +An ASCE shall only send an extended text order where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., in legacy mode, the negotiated Order.orderFlags capability does not have the cannot receive orders bit flag set; in base mode, the negotiated Order.receiveOrdersFlag capability is TRUE), where the extended text order is supported (i.e., in legacy mode, the corresponding negotiated Order.orderSupport capability entry is non-zero; in base mode, the negotiated Order.ExtendedTextLevel capability is non-zero), the particular font has been matched and the codepoints fall within the font's specified codepoint range. + +- An ASCE shall not send an extended text order without codepoints to draw opaque rectangles alone. It should instead use the opaque rectangle order (see clause 8.16.15). +- An ASCE may send an extended text order with DeltaX positioning adjustments for fonts that approximately match with respect to X positioning. + +The extended text order allows an ASCE to specify the text startY position in terms of either the first character's baseline or the first character cell's top. It is recommended that ASCEs use baseline positioning wherever the capabilities and the local terminal characteristics allow, as it may be difficult on certain terminal types to accurately position scalable font text based solely on the first character cell (left, top) position. + +An ASCE shall only send extended text orders using baseline position where the negotiated capabilities indicate that baseline text start positioning is allowed (i.e., in legacy mode, the negotiated Order.textFlags capability baseline start bit flag is set; in base mode, the negotiated Order.baselineStartFlag capability is TRUE). Where that is the case, it shall set the order textFlags1 parameter baseline start bit flag, and set the order startX and startY as the position of the first character cell's (left, baseline) pixel. Otherwise, where the negotiated capabilities indicate that baseline text start positioning is not allowed, it shall clear the order textFlags1 parameter baseline start bit flag and set startX and startY as the position of the first character cell's (left, top) pixel. + +Certain terminal types allow applications to dynamically specify text attributes to fonts at drawing time, in addition to those attributes that are inherent to the font. For example, if a local terminal supports a Courier bold font, then it may allow its applications to draw using that font in association with an italic attribute to achieve an emulated "Courier bold italic" (which may be different in appearance to the actual Courier bold italic corresponding to the available Courier bold font). Where the local terminal supports dynamic text attributes in this manner, a sending ASCE may use the textFlags1 parameter italic, underline and StrikeOut bit flags and the fontWeight parameter (alone or in combination) to indicate that receiving ASCEs should apply the corresponding attributes to the drawn text. + +An ASCE receiving an extended text order draws the text string codepoints on the virtual desktop, subject to any bounds clipping, as follows: + +- The characters are drawn in the foregroundColor. If the order's textFlags2 opaque rectangle bit flag is set, the order clip rectangle is drawn in the backgroundColor. If the order's textFlags2 opaque rectangle bit flag is not set, and the backMixMode is opaque, the character cell backgrounds are drawn in the backgroundColor. +- Where the order's textFlags1 parameter baseline start bit flag is set, startX and startY are the position of the first character cell's (left, baseline) pixel. Otherwise, startX and startY are the position of the first character cell's (left, top) pixel. +- If the order's textFlag2 parameter DeltaXPresent bit flag is set, the characters are positioned using the delta X values provided in the deltaXList parameter. If not, the characters are positioned with any extraSpacing applied to all characters and any break spacing (equal to breakTotalSpacing divided by breakCount) applied to the break character. +- The characters are drawn in the local font that corresponds to the sending ASCE's FontID, subject to any additional attributes indicated by the textFlags1 and/or fontWeight parameters. See clause 8.8.2 for further information on fonts. +- If the local font is scalable, the characters are drawn at the supplied fontWidth and fontHeight. Otherwise they are drawn at the width and height inherent in the font. +- The characters are drawn using the supplied fontWeight and as per the italic, underline and StrikeOut bit flags supplied in the order's textFlags1 parameter. +- If the order's textFlag2 clip to rectangle bit flag is set, the characters are clipped to the order clip rectangle. + +See Table 8-73. + +**Table 8-73 – Extended text order** + +| Parameter | Description | +|-----------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------| +| Primary order header | The primary order header is described in clause 8.16.1. | +| backMixMode | This parameter is the background mix mode to use for this extended text order. See clause 8.16.24 for further information on background mix modes. | + +**Table 8-73 – Extended text order** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| startX (coordinate) | This parameter is the start X virtual desktop coordinate for this extended text order. | +| startY (coordinate) | This parameter is the start Y virtual desktop coordinate for this extended text order. Where the baseline start bit flag is set in the textFlags1 parameter, this corresponds to the baseline pixel of the first character cell. Where the baseline start bit flag is not set in the textFlags1 parameter, this corresponds to the top pixel of the first character cell. | +| backgroundColor | This parameter is the background colour to use for this extended text order. | +| foregroundColor | This parameter is the foreground colour to use for this extended text order. | +| extraSpacing | This parameter specifies the additional spacing in pixels to be applied to individual characters for this extended text order. A value of zero indicates that no additional spacing is to be applied. | +| totalBreakSpacing | This parameter specifies the total of additional spacing in pixels to be applied to break characters for this extended text order. A value of zero indicates that no break spacing is to be applied. | +| breakCount | This parameter specifies the number of break characters in this extended text order. A value of zero indicates either that no break spacing is to be applied or there are no break characters in this order. | +| fontHeight | For scalable fonts, this parameter is the height in pixels of the font to use for this extended text order. See clause 8.8 for further information. | +| fontWidth | For scalable fonts, this parameter is the average character width in pixels of the font to use for this extended text order. See clause 8.8 for further information. | +| fontWeight | This parameter indicates the weight of the font to use for this extended text order. The allowable values are 0..1000, which are interpreted as: light $\leq$ 400 < normal $\leq$ 700 < bold. See clause 8.8 for further information. | +| textFlags1 | This parameter is a set of bit flags indicating the characteristics of the font to use for this extended text order. Defined bit flag values are as follows.
  • • Italic.
  • • Underline.
  • • StrikeOut.
  • • Baseline start.
| +| fontID | This parameter is the sending ASCE's FontID, determined through font negotiation, to use for this extended text order. See clause 8.8 for further information on font negotiation and font mapping. | +| textFlags2 | This parameter is a set of bit flags specifying additional options for this extended text order. Defined bit flag values are as follows.
  • • Opaque rectangle.
  • • Clip to rectangle.
  • • DeltaXPresent.
| +| clipLeft (coordinate) | This parameter is the left X virtual desktop coordinate of the clip rectangle for this extended text order. Where either of the textFlags2 opaque rectangle or clip to rectangle bit flags are not set, this parameter shall be zero. | + +**Table 8-73 – Extended text order** + +| Parameter | Description | +|--------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| clipTop (coordinate) | This parameter is the top Y virtual desktop coordinate of the clip rectangle for this extended text order. Where either of the textFlags2 opaque rectangle or clip to rectangle bit flags are not set, this parameter shall be zero. | +| clipRight (coordinate) | This parameter is the right X virtual desktop coordinate of the clip rectangle for this extended text order. Where either of the textFlags2 opaque rectangle or clip to rectangle bit flags are not set, this parameter shall be zero. | +| clipBottom (coordinate) | This parameter is the bottom Y virtual desktop coordinate of the clip rectangle for this extended text order. Where either of the textFlags2 opaque rectangle or clip to rectangle bit flags are not set, this parameter shall be zero. | +| codePointList | This parameter is a list of codepoints to use for this extended text order. The codepoints shall be in the AS protocol code page. See clause 8.8.1 for further information on codepoints and code pages. | +| deltaXList (coordinate) | This parameter is a list of delta X virtual desktop coordinates to use for this extended text order. This parameter is only present where the DeltaXPresent bit flag is set in the textFlags2 parameter. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.16.13 Frame + +An ASCE shall only send the frame order where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., in legacy mode, the negotiated Order.orderFlags capability does not have the cannot receive orders bit flag set; in base mode, the negotiated Order.receiveOrdersFlag capability is TRUE) and the frame order is supported (i.e., in legacy mode, the corresponding negotiated Order.orderSupport capability entry is non-zero; in base mode, the negotiated Order.FrameLevel capability is non-zero). + +An ASCE receiving a frame order performs the ROP3 parameter raster operation on the brush and the frame border on the virtual desktop, subject to any bounds clipping. + +- The outer frame rectangle is defined by the destLeft, destTop, destRight and destBottom parameters. +- The inner frame rectangle is obtained by adding or subtracting the destWidth and destHeight parameters to/from the horizontal and vertical edges respectively of the outer frame rectangle. + +See Table 8-74. + +**Table 8-74 – Frame order** + +| Parameter | Description | +|------------------------------|------------------------------------------------------------------------------------------------------------| +| Primary order header | The primary order header is described in clause 8.16.1. | +| destLeft (coordinate) | This parameter is the left X virtual desktop coordinate of the destination rectangle for this frame order. | + +**Table 8-74 – Frame order** + +| Parameter | Description | +|--------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| destTop (coordinate) | This parameter is the top Y virtual desktop coordinate of the destination rectangle for this frame order. | +| destRight (coordinate) | This parameter is the right X virtual desktop coordinate of the destination rectangle for this frame order. | +| destBottom (coordinate) | This parameter is the bottom Y virtual desktop coordinate of the destination rectangle for this frame order. | +| destWidth (coordinate) | This parameter is the width in pixels of the rectangle vertical borders for this frame order. | +| destHeight (coordinate) | This parameter is the height in pixels of the horizontal rectangle borders for this frame order. | +| ROP3 | This parameter is the three-way ROP to use for this frame order. For frame orders, the three-way ROP shall not reference a source. See clause 8.16.20 for further information on three-way ROPs. | +| backgroundColor | This parameter is the background colour to use for this frame order. | +| foregroundColor | This parameter is the foreground colour to use for this frame order. | +| brush (group) | This parameter is the brush to use for this frame order. See clause 8.16.22 for further information on brushes. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.16.14 Rectangle + +An ASCE shall only send the rectangle order where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., in legacy mode, the negotiated Order.orderFlags capability does not have the cannot receive orders bit flag set; in base mode, the negotiated Order.receiveOrdersFlag capability is TRUE) and the rectangle order is supported (i.e., in legacy mode, the corresponding negotiated Order.orderSupport capability entry is non-zero; in base mode, the negotiated Order.RectangleLevel capability is non-zero). + +An ASCE receiving a rectangle order performs two associated operations. It uses the ROP2 parameter raster operation, the brush and (depending on the brush type) the background mix mode to draw the interior of the rectangle on the virtual desktop, subject to any bounds clipping. It also uses the ROP2 parameter raster operation, the pen and the background mix mode to draw a bounding line around the rectangle on the virtual desktop, subject to any bounds clipping. + +- The interior of the rectangle is defined by destLeft + 1, destTop + 1, destRight – 1 and destBottom – 1. +- The line is defined by the point sequence (destLeft, destTop), (destRight, destTop), (destRight, destBottom), (destLeft, destBottom), (destLeft, destTop). + +See Table 8-75. + +**Table 8-75 – Rectangle order** + +| Parameter | Description | +|--------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Primary order header | The primary order header is described in clause 8.16.1. | +| backMixMode | This parameter is the background mix mode to use for this rectangle order. See clause 8.16.24 for further information on background mix modes. | +| destLeft (coordinate) | This parameter is the left X virtual desktop coordinate of the destination rectangle for this rectangle order. | +| destTop (coordinate) | This parameter is the top Y virtual desktop coordinate of the destination rectangle for this rectangle order. | +| destRight (coordinate) | This parameter is the right X virtual desktop coordinate of the destination rectangle for this rectangle order. | +| destBottom (coordinate) | This parameter is the bottom Y virtual desktop coordinate of the destination rectangle for this rectangle order. | +| backgroundColor | This parameter is the background colour to use for this rectangle order. | +| foregroundColor | This parameter is the foreground colour to use for this rectangle order. | +| brush (group) | This parameter is the brush to use for this rectangle order. See clause 8.16.22 for further information on brushes. | +| ROP2 | This parameter is the two-way ROP to use for this rectangle order. See clause 8.16.21 for further information on two-way ROPs. | +| pen (group) | This parameter is the pen to use for this rectangle order. See clause 8.16.23 for further information on pens. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.16.15 Opaque rectangle + +An ASCE shall only send the opaque rectangle order where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., in legacy mode, the negotiated Order.orderFlags capability does not have the cannot receive orders bit flag set; in base mode, the negotiated Order.receiveOrdersFlag capability is TRUE) and the opaque rectangle order is supported (i.e., in legacy mode, the corresponding negotiated Order.orderSupport capability entry is non-zero; in base mode, the negotiated Order.OpaqueRectangleLevel capability is non-zero). + +An ASCE receiving an opaque rectangle order fills the destination rectangle on the virtual desktop with the supplied colour, subject to any bounds clipping. See Table 8-76. + +**Table 8-76 – Opaque rectangle order** + +| Parameter | Description | +|-------------------------------|-----------------------------------------------------------------------------------------------------------------------| +| Primary order header | The primary order header is described in clause 8.16.1. | +| destLeft (coordinate) | This parameter is the left X virtual desktop coordinate of the destination rectangle for this opaque rectangle order. | +| destTop (coordinate) | This parameter is the top Y virtual desktop coordinate of the destination rectangle for this opaque rectangle order. | +| destWidth (coordinate) | This parameter is the width in pixels of the rectangle for this opaque rectangle order. | + +**Table 8-76 – Opaque rectangle order** + +| Parameter | Description | +|--------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| destHeight (coordinate) | This parameter is the height in pixels of the rectangle for this opaque rectangle order. | +| color | This parameter is the colour to use for this opaque rectangle order. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### **8.16.16 Line** + +An ASCE shall only send the line order where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., in legacy mode, the negotiated Order.orderFlags capability does not have the cannot receive orders bit flag set; in base mode, the negotiated receiveOrdersFlag capability is TRUE) and the line order is supported (i.e., in legacy mode, the corresponding negotiated Order.orderSupport entry is non-zero; in base mode, the negotiated Order.LineLevel capability is non-zero). + +An ASCE receiving a line order uses the ROP2 parameter raster operation, the pen and the background mix mode to draw a line from startX, startY to endX, endY on the virtual desktop, subject to any bounds clipping. Note that the line foreground colour is specified in the pen. See Table 8-77. + +**Table 8-77 – Line order** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Primary order header | The primary order header is described in clause 8.16.1. | +| backMixMode | This parameter is the background mix mode to use for this line order. See clause 8.16.24 for further information on background mix modes. | +| startX (coordinate) | This parameter is the start X virtual desktop coordinate for this line order. | +| startY (coordinate) | This parameter is the start Y virtual desktop coordinate for this line order. | +| endX (coordinate) | This parameter is the end X virtual desktop coordinate for this line order. | +| endY (coordinate) | This parameter is the end Y virtual desktop coordinate for this line order. | +| backgroundColor | This parameter is the background colour to use for this line order. | +| ROP2 | This parameter is the two-way ROP to use for this line order. See clause 8.16.21 for further information on two-way ROPs. | +| pen (group) | This parameter is the pen to use for this line order. See clause 8.16.23 for further information on pens. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.16.17 Desktop save + +A terminal window manager (if present) may provide local operations to save and restore local desktop areas, either automatically or under local application control, to enhance performance for typical application scenarios. This feature is referred to as "save/restore" or as "save-under". For example: + +- a user drops down a menu that obscures a portion of the application's own window (area A); +- the user then selects a menu item that opens a dialogue (and dismisses the menu) that obscures a different portion of the application window (area B); +- the user then selects a dialogue button that opens a further overlapping dialogue that obscures some of the first dialogue and/or a different portion of the application window (area C); +- the user then dismisses both dialogues. + +Where the window manager provides a save/restore mechanism, area A is saved when the menu drops down and restored when it is dismissed. Similarly, area B is saved when the first dialogue window is created, area C is saved when the second dialogue window is created, and then areas C and B are restored as their respective dialogue windows are destroyed. Note that multiple areas may be saved concurrently, but that the sequencing of saves and restores is such that they behave as a last-in, first-out stack. + +Using save/restores is often significantly faster than forcing a window manager and/or application repaint of the obscured areas. The desktop save order allows an ASCE to propagate local save/restores to other ASCEs and often provides significant AS protocol performance benefits. + +The desktop save mechanism requires that each supporting ASCE allocates a desktop cache for each other hosting ASCE to contain saved areas. Where a save occurs that affects hosted application(s) on a particular ASCE, that ASCE sends a desktop save order to all other ASCEs, specifying the area to be saved, whereupon receiving ASCEs save the corresponding area from the virtual desktop to the desktop cache. When the corresponding restore occurs, the ASCE sends a desktop save order to all other ASCEs, specifying the area to be restored, whereupon the receiving ASCEs restore the corresponding area from the desktop cache to the virtual desktop. + +The desktop cache is logically organized as a set of tiles, the size of which are a specific X and Y granularity. The preferred granularity for a particular ASCE depends on the relative efficiency of save and restores for different size tiles between the virtual desktop and the desktop cache and the degree of memory wastage as the tile size increases. However, while a particular ASCE may advertise its preferred granularities, those values are negotiated, and the ASCE has to be prepared to receive desktop save orders constructed with respect to larger (and possibly less efficient) values. See Appendix I for details of informative values for desktop cache sizing and granularity. + +A desktop save order specifies an action (which is either save or restore), the area to save/restore (as a rectangle) and a pixel offset into the desktop cache. The sending ASCE calculates the pixel offset based on the previous usage of the other ASCEs' desktop cache and the negotiated X and Y granularity as follows: + +- for each desktop save order: at initialization, set the accumulated pixel offset to zero; +- calculate the pixels required for this save/restore as follows: the pixel offset for the order is the accumulated pixel offset: + +$$\text{area width in pixels} = ((\text{area width in pixels} + (\text{negotiated X granularity} - 1)) \text{ div } \text{negotiated X granularity}) * \text{negotiated X granularity};$$ + +$$\text{area height in pixels} = ((\text{area height in pixels} + (\text{negotiated Y granularity} - 1)) \text{ div } \text{negotiated Y granularity}) * \text{negotiated Y granularity};$$ + +$$\text{pixels required for this area} = \text{area width in pixels} * \text{area height in pixels};$$ +- if this is a save operation, add the pixels required for this area to the accumulated pixel offset; +- if this is a restore operation, subtract the pixels required for this area to the accumulated pixel offset. + +An ASCE shall only send the desktop save order where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., in legacy mode, the negotiated Order.orderFlags capability does not have the cannot receive orders bit flag set; in base mode, the negotiated Order.receiveOrdersFlag capability is TRUE) and the desktop save order is supported (i.e., in legacy mode, the corresponding negotiated Order.orderSupport capability entry is non-zero; in base mode, the negotiated Order.DesktopSaveLevel capability is non-zero). + +Where the sending ASCE detects that another ASCE's desktop cache is full, then it shall not send further desktop save orders until it can restore areas already in the desktop cache. This may require that it takes locally-dependent action on its terminal to emulate the save operation and/or force a local repaint on the restore. See Table 8-78. + +**Table 8-78 – Desktop save order** + +| Parameter | Description | +|-----------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Primary order header | The primary order header is described in clause 8.16.1. | +| saveOffset | This parameter is the pixel offset within the receiving ASCE's desktop cache to use for this desktop save order action. | +| desktopLeft (coordinate) | This parameter is the left X virtual desktop coordinate of the desktop rectangle for this desktop save order action. | +| desktopTop (coordinate) | This parameter is the top Y virtual desktop coordinate of the desktop rectangle for this desktop save order action. | +| desktopRight (coordinate) | This parameter is the right X virtual desktop coordinate of the desktop rectangle for this desktop save order action. | +| desktopBottom (coordinate) | This parameter is the bottom Y virtual desktop coordinate of the destination rectangle for this desktop save order action. | +| action | This parameter identifies this desktop save order action. The allowable values are DesktopSave and DesktopRestore. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.16.18 Desktop origin + +Where an ASCE's local desktop is smaller than the virtual desktop, then an ASCE may provide locally-defined mechanisms to scroll the local desktop over the virtual desktop, so that an end user + +can view and control shadow windows hosted on ASCEs with larger desktops. This mechanism is referred to as desktop scrolling. + +Where an ASCE implements desktop scrolling, the local desktop behaves as a viewport onto the virtual desktop and the local desktop origin may be offset from the virtual desktop origin. + +Where an ASCE is hosting windows and its local desktop origin is not coincident with the virtual desktop origin, it shall send a desktop origin order to inform other active ASCEs of its desktop origin in virtual desktop coordinates – that is, with respect to the virtual desktop origin. This mechanism ensures that an ASCE always knows the desktop origin that applies for each incoming ASPDU and for each order within an UpdatePDU (orders) from each ASCE. + +An ASCE shall ensure that it sends a desktop origin order before sending any ASPDUs containing virtual desktop coordinates that are calculated with respect to that desktop origin. + +An ASCE shall ensure that where it sends a desktop origin order, then any virtual desktop coordinates sent preceding that desktop origin order are calculated with reference to the old desktop origin and any virtual desktop coordinates sent following that desktop origin order are calculated with reference to the new desktop origin. This condition may require that an ASCE flush orders and/or other ASPDUs before or after sending a desktop origin order. + +An ASCE may use desktop origin orders from a particular ASCE to implement a desktop scrolling mechanism for shadow windows hosted by that ASCE, by subtracting the sending ASCE's desktop origin from virtual desktop coordinates in incoming ASPDUs. + +In the legacy mode of the AS protocol, an ASCE shall only send the desktop origin order where the negotiated Order.orderSupport capability entry for the screen Blt order is non-zero. In the base mode of the AS protocol, an ASCE shall only send the desktop origin order where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., the negotiated Order.receiveOrdersFlag capability is TRUE) and the desktop origin order is supported (i.e., the negotiated Order.DesktopOriginLevel capability is non-zero). See Table 8-79. + +**Table 8-79 – Desktop origin order** + +| Parameter | Description | +|------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Primary order header | The primary order header is described in clause 8.16.1. | +| desktopOriginX (coordinate) | This parameter is the X virtual desktop coordinate of the sending ASCE's local desktop origin. | +| desktopOriginY (coordinate) | This parameter is the Y virtual desktop coordinate of the sending ASCE's local desktop origin. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.16.19 Colour space + +In the base mode of the AS protocol, an ASCE may use the colour space order to specify the colour space that is in effect for subsequent orders and provide optional colour accuracy information. An ASCE may also use the colour space order to restore the default colour space – RGB with no colour accuracy information. The colour space order is not supported in the legacy mode of the AS protocol. + +An ASCE shall only send the colour space order in the base mode of the AS protocol, where the negotiated capabilities indicate that all other ASCEs can receive orders (i.e., the negotiated + +Order.receiveOrdersFlag capability is TRUE) and the colour space order is supported (i.e., the negotiated Order.ColorSpaceLevel capability is non-zero). + +An ASCE receiving a colour space order should make best efforts to interpret subsequent order colour information with respect to the colour space specified in the colour space order. See Table 8-80. + +**Table 8-80 – Colour space order** + +| Parameter | Description | +|------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| colorSpace | This parameter is the colour space and optional colour accuracy information to use when interpreting subsequent orders. | +| nonStandardParameters | This parameter is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.16.20 Three-way ROPs + +Three-way ROPs are ternary raster-operation codes used by the following orders. + +- Destination Blt: See clause 8.16.4. +- Pattern Blt: See clause 8.16.5. +- Screen Blt: See clause 8.16.6. +- Memory Blt: See clause 8.16.9. +- Memory three-way Blt: See clause 8.16.10. +- Frame: See clause 8.16.13. + +Ternary raster operation codes define the combination of the bits in a source bitmap and a brush (also known as a pattern) with the bits in a destination bitmap. They are bit-wise operations acting on individual bits without colour interpretation, where the bits may be part of palette indices or direct colour values. + +The following are the three operands used in these operations: + +- D Destination bitmap. +- P Selected brush (also called a pattern or stipple). +- S Source bitmap. + +The following are the Boolean operators used in these operations: + +- a Bit-wise AND. +- n Bit-wise NOT (inverse). +- o Bit-wise OR. +- x Bit-wise exclusive OR (XOR). + +All combinations of Boolean operations can be presented in reverse polish notation. For example, the following operation replaces the bits in the destination bitmap with a bit-wise OR of the bits in the source and brush: + +PSo + +Again, the following operation bit-wise ORs the bits in the source and brush with the bits in the destination bitmap: + +DPSoo + +Each raster operation code is a single octet value that represents the result of the boolean operation on predefined brush, source and destination values. For example, the raster operation codes for the PSo and DPSoo operations are shown in the following list: + +| Source values | | | Generated values | | +|---------------|---|---|------------------|-------| +| P | S | D | PSo | DPSoo | +| 0 | 0 | 0 | 0 | 0 | +| 0 | 0 | 1 | 0 | 1 | +| 0 | 1 | 0 | 1 | 1 | +| 0 | 1 | 1 | 1 | 1 | +| 1 | 0 | 0 | 1 | 1 | +| 1 | 0 | 1 | 1 | 1 | +| 1 | 1 | 0 | 1 | 1 | +| 1 | 1 | 1 | 1 | 1 | +| | | | ⇒0xFC | ⇒0xFE | + +In this case, PSo has the raster operation code 0xFC (reading the generated bit values as an octet with the least significant bit at the top); DPSoo has the raster operation code 0xFE. + +The raster operation codes can be interpreted directly to determine if the ternary raster operation references a source, pattern or destination operand, as follows: + +- ternary raster operation does not reference a pattern: bits 0..3 = bits 4..7; +- ternary raster operation does not reference a source: bits 0, 1, 4, 5 = bits 2, 3, 6, 7; +- ternary raster operation does not reference a destination: bits 0, 2, 4, 6 = bits 1, 3, 5, 7. + +The full list of 256 ternary raster operation codes is shown in Table 8-81, with the reverse polish definition for each code4. + +Note that, because raster operations act directly on bit values, without colour interpretation, the results of raster operations may not deliver predictable colour effects when applied on different ASCEs. This may be particularly noticeable for raster operations that reference a destination operand, such as destination invert (i.e., Dn or ROP code 0x55 – see below) which is often used to implement "rubber-band" effects). If a hosted application uses a raster operation of this type, where the hosting ASCE is running on a terminal using a different local colour depth and/or colour model and where the local operation is sent as an order, then the resultant colour(s) may be very different between the hosting ASCE and other ASCEs. + +Consider two ASCEs participating in application sharing within a conference, where ASCE A is hosting applications. ASCE A's local terminal uses a 8 bits-per-pixel palettized RGB colour model whereas ASCE B's local terminal uses a 4 bits-per-pixel palettized RGB colour model. While the difference in colour depths will affect the negotiated Bitmap.sendingBitsPerPixel and therefore the colour depth of palette and ColorTable information sent from ASCE A to ASCE B, at some point ASCE B has to map the protocol colour information, orders and bitmap data onto its local terminal display, which is 4 bits-per-pixel. The following example omits intermediate mapping stages (e.g., from the protocol information to any receiving cache to the local terminal display) and concentrates on the net colour mapping as it affects destination raster operations. + +4 There are alternative reverse polish spellings of the same raster operation code, so although a particular spelling may not be in the table, an equivalent form is present. For example, DSa is equivalent to SDa. + +- A colour-aware application running on ASCE A's local terminal adds colours to a portion of the local terminal palette, such that its 8 bits-per-pixel palette contains (among others) the following entries: + - palette index 0x63 $\Rightarrow$ RGB <204,0,102> ("violet red"); + - palette index 0x9C $\Rightarrow$ RGB <204,204,204> ("light grey"). +- ASCE B's local terminal does not permit application palette management. Its 4 bits-per-pixel palette contains (among others) the following entries: + - palette index 0x1 $\Rightarrow$ RGB <128,0,0> ("dark red"); + - palette index 0xE $\Rightarrow$ RGB <0,255,255> ("cyan"). +- An application on ASCE's local terminal fills an area of a hosted window to RGB <204,0,102> using a local graphics operation. The local terminal graphics system generates an area of screen pixels containing palette index 0x63 ("violet red"). +- ASCE A sends a pattern Blt order for that area, using the raster operation 0xCC (S) and foreground colour RGB <204,0,102>. This assumes a one-to-one mapping between local colour information and the protocol (which is not necessarily always the case). +- ASCE B draws the pattern Blt order to the local terminal display, generating an area of screen pixels containing palette index 0x1 ("dark red"). The colour mapping may be an explicit mapping by ASCE B or may rely on a local colour mapping provided by the local terminal. +- The application on ASCE A's local terminal then inverts the filled area using a local graphics operation. This results in the area of screen pixels being inverted to 0x9C ("light grey"). +- ASCE A sends a destination Blt order for the area, using the raster operation 0x55 (Dn). +- ASCE B draws the destination Blt order to the local terminal display. This results in the area of screen pixels being inverted to 0xE ("cyan"). + +This (admittedly somewhat artificial) example illustrates that, while the initial colour mapping from "violet red" to "dark red" is reasonable, within the constraints of the local terminal's colour models, "cyan" is not a good mapping for "light grey" – the effect of the destination raster operation is to arbitrarily move colour values (by changing the colour indices directly) without reference to colour mappings. In practice, the extent of destination raster operation artefacts depends on the particular local terminal palettes in use – where both local terminals are using linear palettes (of the kind that are typically used as default local terminal palettes) artefacts are relatively benign, but where one or more local terminals or their local applications are using non-linear palettes or explicitly manipulating the local terminal palette contents, destination raster operation artefacts may be significant. + +While the above discussion indicates that application sharing introduces additional colour fidelity issues through the use of orders containing raster operations referencing a destination operand, the extent of those issues is terminal- and application-dependent. However, sending such operations as orders rather than bitmap data typically delivers significantly better performance. Therefore, ASCEs are recommended to provide local terminal mechanisms whereby users can enable or disable the sending of orders containing raster operations referencing a destination operand, so that users can choose between colour fidelity and/or performance on a per-terminal and/or application basis. See Table 8-81. + +**Table 8-81 – Three-way ROPs definition** + +| ROP code
(Hexadecimal) | Reverse polish | +|-----------------------------------|-----------------------| +| 00 | 0 | +| 01 | DPSoon | +| 02 | DPSona | +| 03 | PSon | +| 04 | SDPona | +| 05 | DPon | +| 06 | PDSxnon | +| 07 | PDSaon | +| 08 | SDPnaa | +| 09 | PDSxon | +| 0A | DPna | +| 0B | PSDnaon | +| 0C | SPna | +| 0D | PDSnaon | +| 0E | PDSonon | +| 0F | Pn | +| 10 | PDSona | +| 11 | DSon | +| 12 | SDPxnon | +| 13 | SDPaon | +| 14 | DPSxnon | +| 15 | DPSaon | +| 16 | PSDPSanaxx | +| 17 | SSPxDSxaxn | +| 18 | SPxPDxa | +| 19 | SDPSanaxn | +| 1A | PDSPaox | +| 1B | SDPSxaxn | +| 1C | PSDPAox | +| 1D | DSPDxaxn | +| 1E | PDSox | +| 1F | PDSoan | +| 20 | DPSnaa | +| 21 | SDPxon | +| 22 | DSna | +| 23 | SPDnaon | +| 24 | SPxDSxa | + +**Table 8-81 – Three-way ROPs definition** + +| ROP code
(Hexadecimal) | Reverse polish | +|-----------------------------------|-----------------------| +| 25 | PDSPanaxn | +| 26 | SDPSaox | +| 27 | SDPSxnox | +| 28 | DPSxa | +| 29 | PSDPSaoxxn | +| 2A | DPSana | +| 2B | SSPxPDxaxn | +| 2C | SPDSsoax | +| 2D | PSDnox | +| 2E | PSDPxox | +| 2F | PSDnoan | +| 30 | PSna | +| 31 | SDPnaon | +| 32 | SDPSsoox | +| 33 | Sn | +| 34 | SPDSaox | +| 35 | SPDSxnox | +| 36 | SDPox | +| 37 | SDPoan | +| 38 | PSDPoax | +| 39 | SPDnox | +| 3A | SPDSxox | +| 3B | SPDnoan | +| 3C | PSx | +| 3D | SPDSonox | +| 3E | SPDSnaox | +| 3F | PSan | +| 40 | PSDnaa | +| 41 | DPSxon | +| 42 | SDxPDxa | +| 43 | SPDSanaxn | +| 44 | SDna | +| 45 | DPSnaon | +| 46 | DSPDaox | +| 47 | PSDPxaxn | +| 48 | SDPxa | +| 49 | PDSPDaoxxn | + +**Table 8-81 – Three-way ROPs definition** + +| ROP code
(Hexadecimal) | Reverse polish | +|-----------------------------------|-----------------------| +| 4A | DPSDoax | +| 4B | PDSnox | +| 4C | SDPana | +| 4D | SSPxDSxoxn | +| 4E | PDSPxox | +| 4F | PDSnoan | +| 50 | PDna | +| 51 | DSPnaon | +| 52 | DPSDaox | +| 53 | SPDSxaxn | +| 54 | DPSonon | +| 55 | Dn | +| 56 | DPSox | +| 57 | DPSoan | +| 58 | PDSPoax | +| 59 | DPSnox | +| 5A | DPx | +| 5B | DPSDonox | +| 5C | DPSDxox | +| 5D | DPSnoan | +| 5E | DPSDnaox | +| 5F | DPan | +| 60 | PDSxa | +| 61 | DSPDSaoxxn | +| 62 | DSPDoax | +| 63 | SDPnox | +| 64 | SDPSoax | +| 65 | DSPnox | +| 66 | DSx | +| 67 | SDPSonox | +| 68 | DSPDSonoxxn | +| 69 | PDSxxn | +| 6A | DPSax | +| 6B | PSDPSoaxxn | +| 6C | SDPax | +| 6D | PDSPDoaxxn | +| 6E | SDPSnoax | + +**Table 8-81 – Three-way ROPs definition** + +| ROP code
(Hexadecimal) | Reverse polish | +|-----------------------------------|-----------------------| +| 6F | PDSxnan | +| 70 | PDSana | +| 71 | SSDxPDxaxn | +| 72 | SDPSxox | +| 73 | SDPnoan | +| 74 | DSPDxox | +| 75 | DSPnoan | +| 76 | SDPSnaox | +| 77 | DSan | +| 78 | PDSax | +| 79 | DSPDSoaxxn | +| 7A | DPSDnoax | +| 7B | SDPxnan | +| 7C | SPDSnoax | +| 7D | DPSxnan | +| 7E | SPxDSxo | +| 7F | DPSaan | +| 80 | DPSaa | +| 81 | SPxDSxon | +| 82 | DPSxna | +| 83 | SPDSnoaxn | +| 84 | SDPxna | +| 85 | PDSPnoaxn | +| 86 | DSPDSoaxx | +| 87 | PDSaxn | +| 88 | DSa | +| 89 | SDPSnaoxn | +| 8A | DSPnoa | +| 8B | DSPDxoxn | +| 8C | SDPnoa | +| 8D | SDPSxoxn | +| 8E | SSDxPDxax | +| 8F | PDSanan | +| 90 | PDSxna | +| 91 | SDPSnoaxn | +| 92 | DPSDPoaxx | +| 93 | SPDaxn | + +**Table 8-81 – Three-way ROPs definition** + +| ROP code
(Hexadecimal) | Reverse polish | +|-----------------------------------|-----------------------| +| 94 | PSDPSoaxx | +| 95 | DPSaxn | +| 96 | DPSxx | +| 97 | PSDPSonoxx | +| 98 | SDPSonoxn | +| 99 | DSxn | +| 9A | DPSnax | +| 9B | SDPSoaxn | +| 9C | SPDnax | +| 9D | DSPDoaxn | +| 9E | DSPDSaoxx | +| 9F | PDSxan | +| A0 | DPa | +| A1 | PDSPnaoxn | +| A2 | DPSnoa | +| A3 | DPSDxoxn | +| A4 | PDSPonoxn | +| A5 | PDxn | +| A6 | DSPnax | +| A7 | PDSPoaxn | +| A8 | DPSoa | +| A9 | DPSoxn | +| AA | D | +| AB | DPSono | +| AC | SPDSxax | +| AD | DPSDaoxn | +| AE | DSPnao | +| AF | DPno | +| B0 | PDSnoa | +| B1 | PDSPxoxn | +| B2 | SSPxDSxox | +| B3 | SDPanan | +| B4 | PSDnax | +| B5 | DPSDoxn | +| B6 | DPSDPaoxx | +| B7 | SDPxan | +| B8 | PSDPxax | + +**Table 8-81 – Three-way ROPs definition** + +| ROP code
(Hexadecimal) | Reverse polish | +|-----------------------------------|-----------------------| +| B9 | DSPDaoxn | +| BA | DPSnao | +| BB | DSno | +| BC | SPDSanax | +| BD | SDxPDxan | +| BE | DPSxo | +| BF | DPSano | +| C0 | PSa | +| C1 | SPDSnaoxn | +| C2 | SPDSonoxn | +| C3 | PSxn | +| C4 | SPDnoa | +| C5 | SPDSxoxn | +| C6 | SDPnax | +| C7 | PSDPoaxn | +| C8 | SDPoa | +| C9 | SPDoxn | +| CA | DPSDxax | +| CB | SPDSaoxn | +| CC | S | +| CD | SDPono | +| CE | SDPnao | +| CF | SPno | +| D0 | PSDnoa | +| D1 | PSDPxoxn | +| D2 | PDSnax | +| D3 | SPDSaoxn | +| D4 | SSPxPDxax | +| D5 | DPSanan | +| D6 | PSDPSaoxx | +| D7 | DPSxan | +| D8 | PDSPxax | +| D9 | SDPSaoxn | +| DA | DPSDanax | +| DB | SPxDSxan | +| DC | SPDnao | +| DD | SDno | + +**Table 8-81 – Three-way ROPs definition** + +| ROP code
(Hexadecimal) | Reverse polish | +|-----------------------------------|------------------------------------| +| DE | SDP xo | +| DF | SDP ano | +| E0 | PDS oa | +| E1 | PDS oxn | +| E2 | DSPD xax | +| E3 | PSDP aoxn | +| E4 | SDPS xax | +| E5 | PDSP aoxn | +| E6 | SDPS anax | +| E7 | SP x PD xan | +| E8 | SSP x DS xax | +| E9 | DSPDS anaxxn | +| EA | DPS ao | +| EB | DPS xno | +| EC | SDP ao | +| ED | SDP xno | +| EE | DS o | +| EF | SDP nnoo | +| F0 | P | +| F1 | PDS ono | +| F2 | PDS nao | +| F3 | PS no | +| F4 | PSD nao | +| F5 | PD no | +| F6 | PDS xo | +| F7 | PDS ano | +| F8 | PDS ao | +| F9 | PDS xno | +| FA | Dp o | +| FB | DPS nnoo | +| FC | P so | +| FD | PSD nnoo | +| FE | DPS oo | +| FF | 1 | + +### 8.16.21 Two-way ROPs + +Two-way ROPs are binary raster-operation codes used by the following orders: + +- Rectangle See clause 8.16.14. +- Line See clause 8.16.16. + +Binary raster operation codes define the combination of the bits in a pen or brush with the bits in a destination bitmap. They are bit-wise operations acting on individual bits without colour interpretation, where the bits may be part of palette indices or direct colour values. + +The following are the two operands used in these operations: + +- D Destination bitmap. +- P Pen (or brush). + +The following are the Boolean operators used in these operations: + +- a Bit-wise AND. +- n Bit-wise NOT (inverse). +- o Bit-wise OR. +- x Bit-wise exclusive OR (XOR). + +All combinations of Boolean operations can be presented in reverse polish notation. For example, the following operation replaces bits in the destination bitmap with a bit-wise OR of bits in the destination bitmap and the pen/brush. + +DPo + +Each binary raster operation code is a single octet value consisting of the result of the Boolean operation on predefined pen/brush and destination values, which is then incremented by one. For example, the raster operation codes for the DPo and DPan operations are shown in the following list: + +| Source values | | Generated values | | +|---------------|---|------------------------|------------------------| +| P | D | DPo | DPan | +| 0 | 0 | 0 | 1 | +| 1 | 1 | 1 | 1 | +| 1 | 0 | 1 | 1 | +| 1 | 1 | 1 | 0 | +| | | $\Rightarrow 0x0E + 1$ | $\Rightarrow 0x07 + 1$ | + +In this case, DPo has the raster operation code 0x0F (reading the generated bit values as an octet with the least significant bit at the top – and then incrementing); DPan has the raster operation code 0x08. + +Note that, because raster operations act directly on bit values, without colour interpretation, the results of raster operations may not deliver predictable colour effects when applied on different ASCEs. This may be particularly noticeable for raster operations that reference a destination operand, such as destination invert (i.e., Dn or ROP code 0x6 – see below) which is often used to implement "rubber-band" effects). If a hosted application uses a raster operation of this type, where the hosting ASCE is running on a terminal using a different local colour depth and/or colour model and where the local operation is sent as an order, then the resultant colour(s) may be very different between the hosting ASCE and other ASCEs. See clause 8.16.20 for further discussion. + +The full list of 16 binary raster operation codes is shown in Table 8-82, with the reverse polish definition for each code5. + +**Table 8-82 – Two-way ROPs definition** + +| ROP code
(Hexadecimal) | Reverse polish | +|-----------------------------------|-----------------------| +| 01 | 0 | +| 02 | DPon | +| 03 | DPna | +| 04 | Pn | +| 05 | PDna | +| 06 | Dn | +| 07 | DPx | +| 08 | DPan | +| 09 | DPa | +| 0A | DPxn | +| 0B | D | +| 0C | DPno | +| 0D | P | +| 0E | PDno | +| 0F | DPo | +| 10 | 1 | + +### 8.16.22 Brushes + +Brushes (also known as patterns) are used to paint interior areas. They are used by the following orders: + +- Pattern Blt: See clause 8.16.5. +- Memory three-way Blt: See clause 8.16.10. +- Frame: See clause 8.16.13. +- Rectangle: See clause 8.16.14. + +The brush parameters are subject to order parameter encoding. See clause 8.16.3.3 for further information. See Table 8-83. + +5 There are alternative reverse polish spellings of the same raster operation code, so although a particular spelling may not be in the table, an equivalent form is present. For example, DPx is equivalent to PDx. + +**Table 8-83 – Brush definition** + +| Parameter | Description | +|-----------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| originX | This parameter is ignored where the brush type is solid or null. Where the brush type is hatch or pattern, this parameter is the X coordinate of the brush origin. | +| originY | This parameter is ignored where the brush type is solid or null. Where the brush type is hatch or pattern, this parameter is the Y coordinate of the brush origin. | +| Style |

This parameter indicates the style to use for this brush. Allowable values are as follows:

  • • Solid brush      The interior area is painted using the order foreground colour and the ROP2 or ROP3 in the order.
  • • Null brush        The brush does not contribute to the painting of the interior area.
  • • Hatched brush    The interior area is painted using the brush hatch style in the order foreground and background colours, with respect to the brush origin and using the ROP2 or ROP3 in the order.
  • • Pattern brush    The interior area is painted using the brush pattern in the order foreground and background colours, with respect to the brush origin and using the ROP2 or ROP3 in the order.
| +| Hatch |

Where the style parameter indicates a hatched brush, this parameter indicates the hatch style to use for this brush. Allowable values are as follows:

  • • Horizontal hatch
  • • Vertical hatch
  • • Forward diagonal hatch
  • • Backward diagonal hatch
  • • Cross hatch
  • • Diagonal cross hatch

Where the style parameter indicates a pattern brush, this parameter is the first octet of the pattern.

| +| pattern | Where the style parameter indicates a pattern brush, this parameter contains octets two through eight of the pattern. | +| nonStandardBrushParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard brush parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +Table 8-84 shows how the various brush hatch styles appear when used to paint the interior of a rectangle. + +**Table 8-84 – Brush hatch styles** + +![Backward diagonal hatch pattern Forward diagonal hatch pattern Cross hatch pattern Horizontal hatch pattern Diagonal cross hatch pattern Vertical hatch pattern](32b5e45ea3a0c88ec63c5721f6982537_img.jpg) + +| | | | | +|-------------------|--|------------------|--| +| Backward diagonal | | Forward diagonal | | +| Cross | | Horizontal | | +| Diagonal cross | | Vertical | | + +T1605260-98 + +Backward diagonal hatch pattern Forward diagonal hatch pattern Cross hatch pattern Horizontal hatch pattern Diagonal cross hatch pattern Vertical hatch pattern + +#### 8.16.22.1 Brush patterns + +A brush pattern consists of a bicolour 8 pixel by 8 pixel bitmap, where one bits are drawn in the background colour and zero bits are drawn in the foreground colour. + +The pattern bits are sent as 8 octets of uncompressed bitmap data, arranged so that pixel $x, y$ is in octet $y + 1$ , bit position $(x \bmod 8)$ . The first octet is sent in the hatch parameter and octets two through eight are sent in the pattern parameter. + +#### 8.16.22.2 Brush origin + +When a hatch or pattern brush is used to paint an interior area, the brush is replicated to fill the area, with respect to the brush origin. The brush origin defines the position of the brush (top, left) pixel on the virtual desktop from which replication should start. The brush replication process can be summarized as follows: + +- position the brush (top, left) pixel at the brush origin on the virtual desktop; +- copy the brush horizontally and vertically throughout the virtual desktop, clipping to the interior area. + +### 8.16.23 Pens + +Pens are used to paint lines. They are used by the following orders: + +- Rectangle: See clause 8.16.14. +- Line: See clause 8.16.16. + +The AS protocol supports the following pen types: + +- Solid. +- Dashed. +- Dotted. +- Dash-dot. +- Dash-dot-dot. +- Null. + +The pen parameters are subject to order parameter encoding. See clause 8.16.3.3 for further information. See Table 8-85. + +**Table 8-85 – Pen definition** + +| Parameter | Description | +|---------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| style | This parameter indicates the style to use for this pen. Allowable values are as follows:
  • • Solid pen.
  • • Dashed pen.
  • • Dotted pen.
  • • Dash-dot pen.
  • • Dash-dot-dot pen.
  • • Null pen.
| +| width | This parameter indicates the width to use for the pen. The allowable value is 1. | +| color | This parameter is the colour to use for the pen. | +| nonStandardPenParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard pen parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +For a solid pen, all pixels along the path of the line are drawn using the designated pen colour and the ROP2 in the order. + +For dashed, dotted, dash-dot or dash-dot-dot pens, the line is drawn using a foreground/background pixel sequence determined by the pen style, where: + +- foreground pixels are drawn using the pen foreground colour and the ROP2 in the order; +- background pixels are not drawn if the background mix is transparent (see clause 8.16.24); +- background pixels are drawn using the order background colour and ROP2 if the background mix is opaque (see clause 8.16.24). + +For a null pen, no line pixels are drawn. + +Table 8-86 shows how the various pen styles appear when used to draw a rectangle border. + +**Table 8-86 – Pen styles** + +![Diagram showing five rectangular borders illustrating different pen styles: solid, dashed, dotted, dash-dot, and dash-dot-dot.](88f11ea225d70100947208df3d30ece1_img.jpg) + +The image displays five rectangular borders stacked vertically, each representing a different pen style. From top to bottom: 1. A solid black rectangular border. 2. A dashed black rectangular border. 3. A dotted black rectangular border. 4. A dash-dot black rectangular border. 5. A dash-dot-dot black rectangular border. + +Diagram showing five rectangular borders illustrating different pen styles: solid, dashed, dotted, dash-dot, and dash-dot-dot. + +T1605270-98 + +### 8.16.24 Background mix + +A background mix is used in the following orders: + +- Text: See clause 8.16.11. +- Extended text: See clause 8.16.12. +- Rectangle: See clause 8.16.14. +- Line: See clause 8.16.16. + +For the text and extended text orders, the background mix determines whether background pixels are drawn or not for the text character cells. Where the background mix is transparent, character cell background pixels are not drawn. Where the background mix is opaque (and for the extended text order, an opaque rectangle is not required), the character cell background pixels are drawn in the order's background colour. + +For the rectangle and line orders, the background mix determines whether pen off pixels are drawn for dashed, dotted, dash-dot and dash-dot-dot pen styles. Where the background mix is transparent, pen off pixels are not drawn. Where the background mix is opaque, the pen off pixels are drawn using the order's background colour and the ROP2 parameter. See clause 8.16.23 for further information on pens and 8.16.21 for further information on binary raster operation codes. + +For the rectangle order, the background mix also determines whether interior background pixels are drawn when a hatched brush is used. For this case, where the background mix is transparent, background pixels are not drawn, but, where the background mix is opaque, background pixels are drawn using the order's background colour and the ROP2 parameter. The background mix does not affect interior background pixels for other brush styles – for solid brushes, background pixels are not applicable; for pattern brushes, background pixels are always drawn. + +The AS protocol supports the following background mix types. See Table 8-87. + +**Table 8-87 – Background mix types** + +| Background mix type | Definition | +|---------------------|----------------------------------| +| Opaque | Background pixels are drawn. | +| Transparent | Background pixels are not drawn. | + +## 8.17 Bitmap updates + +An ASCE sends bitmap updates to all ASCEs within the conference by sending an UpdatePDU containing bitmap data in the manner indicated in Table 6-3. The content of the UpdatePDU containing bitmap data is shown in Table 8-88. + +An ASCE shall only send uncompressed bitmap data where the negotiated Bitmap.sendingBitsPerPixel capability value is one, four or eight. An ASCE shall only send compressed bitmap data where the negotiated Bitmap.sendingBitsPerPixel capability is four or eight, and the negotiated Bitmap.bitmapCompressionFlag capability is TRUE. Compressed bitmap data shall not be sent where the negotiated Bitmap.sendingBitsPerPixel capability is one. + +On receipt of an UpdatePDU containing bitmap data, the receiving ASCE (after any required decompression) performs a copy from (top, left) of the bitmap to (top, left) of the destination rectangle on the virtual desktop for the destination width and height. Where the bitmap width and/or height are larger than the destination width and/or height, the receiving ASCE shall clip the bitmap to the destination rectangle. The ASCE shall interpret bitmap pixel values using the last received UpdatePDU (palette) ASPDU. See clause 8.15 for further information on palettes. + +**Table 8-88 – UpdatePDU (bitmap)** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| destLeft | This parameter is the left X virtual desktop coordinate of the destination rectangle for the bitmap data. | +| destTop | This parameter is the top Y virtual desktop coordinate of the destination rectangle for the bitmap data. | +| destRight | This parameter is the right X virtual desktop coordinate of the destination rectangle for the bitmap data. | +| destBottom | This parameter is the bottom Y virtual desktop coordinate of the destination rectangle for the bitmap data. | +| width | This parameter is the width in pixels of the bitmap data. The bitmap width shall be larger than or equal to the width of the destination rectangle (see above). | +| height | This parameter is the height in pixels of the bitmap data. The bitmap height shall be larger than or equal to the height of the destination rectangle (see above). | +| bitsPerPixel | This parameter is the bits-per-pixel. This parameter shall be the same as the negotiated Bitmap.sendingBitsPerPixel value. See clause 8.2.4 for further information. | +| compressedFlag | This parameter indicates whether the bitmap data (see below) is compressed or not. A value of TRUE indicates that the bitmap data is compressed and a value of FALSE that it is not. | +| bitmapData | This parameter is the bitmap data. The bitmap may be uncompressed (see clause 8.17.1) or compressed (see clause 8.17.2). | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.17.1 Uncompressed bitmap data + +Uncompressed bitmap data represents the bitmap as a series of rows, where row zero starts at the highest pixel Y coordinate. That is, row 0 starts at (bottom, left). + +Within a row, pixel values are packed into octets, starting from the left-most pixel: + +- For 1 bits-per-pixel bitmap data, each octet contains eight pixels, with the left-most pixel in the most significant bit. +- For 4 bits-per-pixel bitmap data, each octet contains two pixels, with the left-most pixel in the most significant four bits. +- For 8 bits-per-pixel bitmap data, each octet contains one pixel value. + +Each row of bitmap data is padded to a four-octet boundary. This means that the size of a row is: + +$(((((\text{bitmap-width-in-pixels} * \text{bit-per-pixel}) + 31) \text{ div } 32) * 4) \text{ octets.}$ + +The total size of the bitmap data is: + +$(\text{height-of-bitmap} * \text{octets-per-row}) \text{ octets.}$ + +The following diagram illustrates the layout of pixels in uncompressed bitmap data for row 0 of a $15 \times 8$ bitmap, at 1, 4 and 8 bits-per-pixel, respectively. + +![Diagram of a 15x8 pixel bitmap. The width is 15 pixels (labeled 'Width = 15') and the height is 8 pixels (labeled 'Height = 8'). The top-left pixel is labeled 'Pixel 0, 0' and the top-right is 'Pixel 14, 0'. The bottom-left is 'Pixel 0, 7' and the bottom-right is 'Pixel 14, 7'. The bottom row (Row 0) is divided into 16 columns: 15 numbered 0-14 and a final column labeled 'E'. The columns are grouped into four sets of four: (0-3), (4-7), (8-11), and (12-15).](3ce6b213ec556257e32ff7451182369d_img.jpg) + +Diagram of a 15x8 pixel bitmap. The width is 15 pixels (labeled 'Width = 15') and the height is 8 pixels (labeled 'Height = 8'). The top-left pixel is labeled 'Pixel 0, 0' and the top-right is 'Pixel 14, 0'. The bottom-left is 'Pixel 0, 7' and the bottom-right is 'Pixel 14, 7'. The bottom row (Row 0) is divided into 16 columns: 15 numbered 0-14 and a final column labeled 'E'. The columns are grouped into four sets of four: (0-3), (4-7), (8-11), and (12-15). + +| | | | | +|--------------|-------------------------------|-----------|-------------| +| Row 0: 1 bpp | 0 1 2 3 4 5 6 7 8 9 A B C D E | PAD | = 4 octets | +| Row 0: 4 bpp | 0 1 2 3 // | C D E PAD | = 8 octets | +| Row 0: 8 bpp | 0 1 // | E PAD | = 16 octets | + +T1602360-97 + +### 8.17.2 Compressed bitmap data + +For compressed bitmap data, the actual compressed bitmap information is preceded by the compressed bitmap header described in Table 8-89. + +**Table 8-89 – Compressed bitmap header** + +| Parameter | Description | +|-----------------------------|-------------------------------------------------------------------------------------------| +| mainBodySize | This parameter is the length in octets of the compressed bitmap data (after compression). | +| rowSize | This parameter is the length in octets of a single row of the uncompressed bitmap data. | +| uncompressedSize | This parameter is the length in octets of the uncompressed bitmap data. | +| compressedBitmapData | This parameter is the compressed bitmap data. | + +AS protocol bitmap compression is oriented to the compression of window manager data, where runs may occur in both X and Y. The AS protocol represents a compressed bitmap as a sequence of compression codes, where a particular bitmap may be represented by different valid code sequences. + +Compression codes are of two types: + +- Difference codes are two-dimensional runs where a series of pixel values are determined by the compression code and the corresponding pixel values in previous rows. The Fill, Mix, FillOrMix, SetMix\_Mix, SetMix\_FillOrMix, FillOrMix\_1, and FillOrMix\_2 compression codes (see Table 8-90) are difference codes, which are defined in terms of one or more fill and/or mix operation(s). + - The fill operation sets the current pixel in the current row to the corresponding pixel in the previous row. This is a straightforward copy operation. + - The mix operation sets the current pixel in the current row to the exclusive OR (XOR) of the current mix value and the corresponding pixel in the previous row. The mix value defaults to 0xFF (which is set at the start of a compression/decompression pass for each new bitmap) and may be updated by the SetMix\_Mix and SetMix\_FillOrMix codes. + +Because different codes reference the previous bitmap row, they have defined special case operations for processing the first row (see the individual code operation definitions in Table 8-90). + +- Colour codes are linear runs where a series of pixel values are determined by reference to the compression code alone. The Color, Copy, CopyPacked, Bicolour, Black and White compression codes (see Table 8-90) are colour codes. + +A compression code consists of a code identifier, followed by an optional length field, followed by optional associated data dependent on the code. A particular compression code may have multiple encodings, dependent on the size of the length field. See Table 8-90 for further information on encodings with respect to length. + +The length field may be further encoded dependent on the code. See Table 8-91 for further information on length encodings. Where present, the length (after any required decoding) may specify the number of octets of associated data and the required repeat. + +A receiving ASCE interprets a sequence of bitmap compression codes contained within a UpdatePDU (bitmap) to generate a decompressed bitmap (in the format described in clause 8.17.1), as follows: + +- 1) Set the initial pixel position to (bottom, left); set the initial mix value to 0xFF. +- 2) Decode the next code and calculate its length value (n). +- 3) Perform the defined code operation for the defined repeat (wrapping to the next row as necessary). +- 4) Update the pixel position (wrapping to the next row as necessary). +- 5) Repeat steps 2 through 4 until all codes are processed. + +For example, if the current pixel position is pixel 60 in row 6 and the next code is fill, with encoding 3b<0x0>,5b, the receiving ASCE sets the values of pixel 60..67 to the values in pixels 60..67 in row 5 and updates the pixel position to 68. + +Where the original bitmap (prior to compression) contains padding (see clause 8.17.1), the sending ASCE shall treat the padding as pixel data for compression purposes. This allows the receiving ASCE to treat the compression code sequence as referring to a linear series of pixels (independent of padding considerations): + +- Table 8-90 summarizes the encodings, type of length encoding, operation and repeat for each defined code. +- Table 8-91 summarizes the encoding for each length type. +- Table 8-92 summarizes the notation used in Tables 8-90 and 8-91. + +The compressed bitmap data is packed into the compressedBitmapData parameter by filling in successive bits into each octet beginning with the most significant bit of each field and filling towards the least significant bit. Where fields are less than an octet, successive fields are filled into the next free most significant bit. Where a single field occupies two octets, octets are filled in increasing significance, with the highest-order, or most significant, octet placed in the second octet6. + +--- + +6 While two octet fields have octets filled in increasing significance, the constituent bits within each octet continue to be filled beginning with the most significant bit of each field and filling towards the least significant bit. + +**Table 8-90 – Bitmap compression codes** + +| Code | Encoding | Length type | Operation | Repeat | +|---------------------|----------------------------------------------------------------------------------------------------------------------------|-------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------| +| Fill 9 (Note 1) | 3b<0x0>,5b
8b<0x00>,8b
8b<0xF0>,16b | A | row 1: $\text{pixel}^i \leftarrow 0$
row 2..H: $\text{pixel}^i \leftarrow \text{pixel}^{i-r-1}$ | $i = 0..n-1$ | +| Mix | 3b<0x1>,5b
8b<0x20>,8b
8b<0xF1>,16b | A | row 1: $\text{pixel}^i \leftarrow \text{mix}$
row 2..H: $\text{pixel}^i \leftarrow \text{pixel}^{i-r-1} \wedge \text{mix}$ | $i = 0..n-1$ | +| FillOrMix | 3b<0x2>,5b,(n+7)/8
8b<0x40>,8b,(n+7)/8
8b<0xF2>,16b,(n+7)/8 | A8 | row 1: $\text{pixel}^i \leftarrow 0$ or
$\text{pixel}^i \leftarrow \text{mix}$
row 2..H: $\text{pixel}^i \leftarrow \text{pixel}^{i-r-1}$ or
$\text{pixel}^i \leftarrow \text{pixel}^{i-r-1} \wedge \text{mix}$ | $i = 0..n-1$
for (n+7)/8 masks | +| Color | 3b<0x3>,5b,
8b<0x60>,8b,
8b<0xF3>,16b, | A | $\text{pixel}^i \leftarrow \text{color}$ | $i = 0..n-1$ | +| Copy | 3b<0x4>,5b,n
8b<0x80>,8b,n
8b<0xF4>,16b,n | A | $\text{pixel}^i \leftarrow \text{color}^i$ | $i = 0..n-1$ | +| CopyPacked (Note 2) | 3b<0x5>,5b,n/2
8b<0xA0>,8b,n/2
8b<0xF5>,16b,n/2 | A | $\text{pixel}^{i*2} \leftarrow \text{packed\_color}^i(\text{high})$ ,
$\text{pixel}^{(i*2)+1} \leftarrow \text{packed\_color}^i(\text{low})$ | $i = 0..(n/2)-1$ | +| SetMix_Mix | 4b<0xC>,4b,
8b<0xC0>,8b,
8b<0xF6>,16b, | B | $\text{mix} \leftarrow \text{color}$ ,
row 1: $\text{pixel}^i \leftarrow \text{mix}$
row 2..H: $\text{pixel}^i \leftarrow \text{pixel}^{i-r-1} \wedge \text{mix}$ | $i = 0..n-1$ | +| SetMix_FillOrMix | 4b<0xD>,4b,,(n+7)/8
8b<0xD0>,8b,,(n+7)/8
8b<0xF7>,16b,,(n+7)/8 | B8 | $\text{mix} \leftarrow \text{color}$ ,
row 1: $\text{pixel}^i \leftarrow 0$ or
$\text{pixel}^i \leftarrow \text{mix}$
row 2..H: $\text{pixel}^i \leftarrow \text{pixel}^{i-r-1}$ or
$\text{pixel}^i \leftarrow \text{pixel}^{i-r-1} \wedge \text{mix}$ | $i = 0..n-1$
for (n+7)/8 masks | +| Bicolor | 4b<0xE>,4b,,
8b<0xE0>,8b,,
8b<0xF8>,16b,, | B | $\text{pixel}^{i*2} \leftarrow \text{color1}$ ,
$\text{pixel}^{(i*2)+1} \leftarrow \text{color2}$ | $i = 0..n-1$ | +| FillOrMix_1 | 8b<0xF9>{,} | C | row 1: $\text{pixel}^i \leftarrow 0$ or
$\text{pixel}^i \leftarrow \text{mix}$
row 2..H: $\text{pixel}^i \leftarrow \text{pixel}^{i-r-1}$ or
$\text{pixel}^i \leftarrow \text{pixel}^{i-r-1} \wedge \text{mix}$ | $i = 0..7$ for
1 mask | +| FillOrMix_2 | 8b<0xFA>{,} | C | row 1: $\text{pixel}^i \leftarrow 0$ or
$\text{pixel}^i \leftarrow \text{mix}$
row 2..H: $\text{pixel}^i \leftarrow \text{pixel}^{i-r-1}$ or
$\text{pixel}^i \leftarrow \text{pixel}^{i-r-1} \wedge \text{mix}$ | $i = 0..7$ for
1 mask | +| White | 8b<0xFD> | C | $\text{pixel} \leftarrow 0xF$ (4bpp)/ $0xFF$ (8bpp) | 1 | +| Black | 8b<0xFE> | C | $\text{pixel} \leftarrow 0$ | 1 | + +NOTE 1 – Where this fill immediately follows another fill (i.e., there are consecutive adjoining fill codes), the receiving ASCE shall insert a single mix code of encoding 3b<0x1>,5b. + +NOTE 2 – An ASCE shall only send compressed bitmap data containing the CopyPacked code where the negotiated Bitmap.sendingBitsPerPixel capability value is four and it is sending four bits-per-pixel compressed bitmap data. See clause 8.2.4 for further information. + +**Table 8-91 – Bitmap compression codes: Length encoding** + +| Length type | Range | Calculation | +|-------------|-----------------|-----------------------| +| A | 5b: 1..31 | $n = \text{len}$ | +| | 8b: 0..255 | $n = \text{len} + 32$ | +| | 16b: 288..65535 | $n = \text{len}$ | +| B | 4b: 1..15 | $n = \text{len}$ | +| | 8b: 0..255 | $n = \text{len} + 16$ | +| | 16b: 272..65535 | $n = \text{len}$ | +| A8 | 5b: 1..31 | $n = \text{len} * 8$ | +| | 8b: 0..254 | $n = \text{len} + 1$ | +| | 16b: 256..65535 | $n = \text{len}$ | +| B8 | 4b: 1..31 | $n = \text{len} * 8$ | +| | 8b: 0..254 | $n = \text{len} + 1$ | +| | 16b: 256..65535 | $n = \text{len}$ | +| C | n/a | $n = 1$ | + +**Table 8-92 – Bitmap compression codes: Legend** + +| Notation | Description | | | | | | | | | | +|------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------|---|---------------------------------|-----------------|--|-----------------|-----------------|--|-----------------| +| nb | The field f is n bits in size. For example, mix may be encoded with an initial 3-bit field of value 0x1. | | | | | | | | | | +| | The field contains a length of the type specified in the length column. The extracted length value (calculated depending on encoding as per Table 8-91) is referred to as n in the remainder of the encoding and is typically used to specify the number of following octets of mask, color or packed_color fields and to generate the repeat. | | | | | | | | | | +| n | There are n occurrences of field type f. | | | | | | | | | | +| |

The field contains a mask. A mask is an octet encoding 8 pixels as bits. A one-bit value indicates the mix value should be used (see below) and a zero bit value indicates the fill value should be used. The pixel-to-bit encoding is as follows:

pixels (highest pixel address = 7) ⇒ bits (most significant bit = 7)
0 1 2 3 4 5 6 7 7 6 5 4 3 2 1 0
a b c d e f g h h f d b g e c a

For example, a mask of 0xAA (i.e., bits 10101010) expands to a series of pixels of fill, fill, mix, mix, fill, fill, mix, mix.

| pixels (highest pixel address = 7) | ⇒ | bits (most significant bit = 7) | 0 1 2 3 4 5 6 7 | | 7 6 5 4 3 2 1 0 | a b c d e f g h | | h f d b g e c a | +| pixels (highest pixel address = 7) | ⇒ | bits (most significant bit = 7) | | | | | | | | | +| 0 1 2 3 4 5 6 7 | | 7 6 5 4 3 2 1 0 | | | | | | | | | +| a b c d e f g h | | h f d b g e c a | | | | | | | | | +| | The field contains an octet of colour information. For four bits-per-pixel bitmap data, the most significant four bits should be ignored. The bitmap compression encoding does not place any interpretation on colour values. | | | | | | | | | | +| | The field contains a packed octet of colour value. The packed colour value is only allowable for four bits-per-pixel bitmap data, where it consists of two four-bit colour values, where the first colour is in the most significant four bits and the second colour is in the least significant four bits. The bitmap compression encoding does not place any interpretation on colour values. | | | | | | | | | | +| , | Field f1 precedes field f2. For example, fill may be encoded by a 3-bit field of 0x0, followed by a 5-bit field giving the length. | | | | | | | | | | + +**Table 8-92 – Bitmap compression codes: Legend** + +| Notation | Description | +|--------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| {,} | Field f with value is implied and is not included by the sending ASCE. For example, code FillOrMix_1 has an initial octet of 0xF9 which implies mask value 0x03. | +| $p \leftarrow e$ | Pixel p is assigned the expression e. For example, the operation for black is $\text{pixel} \leftarrow \text{black}$ , which replaces the current pixel with the black colour value (see below). | +| $p \leftarrow e1 \wedge e2$ | Pixel p is assigned the bit-wise exclusive OR (XOR) of the two expressions. | +| op1, op2 | Perform operation op1 then operation op2. | +| op1 or op2 | Perform operation op1 for corresponding zero mask bits and operation op2 for corresponding one mask bits, using the mask pixel to bit encoding (see above). | +| row 1: op1 or
row 2..H: op2 | Perform operation op1 for pixels in the first row of the destination bitmap and operation op2 for pixels in all other rows. | +| Pixel i | The current pixel in the current row of the destination bitmap. Where the code has a repeat, i takes the values indicated by the repeat column. | +| Pixel i,r-1 | The corresponding pixel in the previous row of the destination bitmap. Where the code defines a repeat, i takes the values indicated by the repeat column. For example, if the current pixel is pixel 35 in row 6, pixel i,r-1 is pixel 35 in row 5. | +| Mix | The current mix value. The mix value is reset to 0xFF at the start of decompression of a new UpdatePDU (bitmap) or cache bitmap order (see clause 8.16.7) and is thereafter set by the SetMix_Mix and/or SetMix_FillOrMix codes. | + +## 8.18 Input + +Input handling is tightly integrated with conducted mode (if in effect within the conference) and with the conference control policy. Depending on conductorship and/or control state, the ASCE may or may not have the right to provide input to hosted or shadow windows within the conference. See clause 8.19 for further information on conducted mode and clauses 8.12 and 8.13 for further information on control mechanisms. + +An ASCE may provide input to peer ASCEs within the conference by sending an InputPDU containing input events in the manner indicated in Table 6-3. The content of the InputPDU is shown in Table 8-93. Input events may be of one of the following three types: + +- Pointing device event: See clause 8.18.1. +- Keyboard event: See clause 8.18.2. +- Input synchronization event: See clause 8.18.6. + +**Table 8-93 – InputPDU** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ShareData header | The ShareData header is described in clause 8.3. | +| eventList | This parameter is a list of input events (see below). | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +### 8.18.1 Pointing device events + +Depending on conductorship and control state, an ASCE may queue a pointing device event within an InputPDU when a local pointing device event occurs. A receiving ASCE shall process pointing device events with respect to the current local control state and policy. The pointing device event is described in Table 8-94. + +Pointing device events model a three-button pointing device, where: + +- Button 1 is the logical left button (commonly used for selection). +- Button 2 is the logical right button. +- Button 3 is the logical middle button. + +Certain terminals allow for re-assignment of the local logical to physical pointing device button mapping, under end-user or programmatic control, such that (for example) the logical left (or selection) button is swapped to the physical right button. Where such a facility is provided, the ASCE shall ensure that pointing device events are sent in terms of the logical button assignments. + +Pointing device events contain the virtual desktop coordinate of the point where the event occurred. The sending ASCE is responsible for constraining the event to the virtual desktop. Receiving ASCEs are responsible for constraining any local pointing device events generated from received pointing device events to the local desktop. + +**Table 8-94 – Pointing device event** + +| Parameter | Description | +|------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| eventTime | This parameter is the local ASCE time in milliseconds when this event occurred. | +| pointingDeviceFlags |

This parameter is a set of bit flags identifying and qualifying the pointing device event. Defined bit flag values are as follows:

  • • Move.
  • • Button 1.
  • • Button 2.
  • • Button 3.
  • • Down.

See below for further information on the interpretation of pointing device event flags.

| +| pointingDeviceX | This parameter is the X virtual desktop coordinate of the pointing device event. | +| pointingDeviceY | This parameter is the Y virtual desktop coordinate of the pointing device event. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +Table 8-95 describes the usage of the pointing device flags for a three-button pointing device. The sending ASCE is responsible for setting the pointing device flags in pointing device events. Receiving ASCEs are responsible for interpreting the pointing device flags with respect to the local terminal characteristics. + +The AS protocol does not support pointing device double-click events. Where a double-click occurs on the local terminal, an ASCE shall send the corresponding pointing device event sequence button down, button up, button down, button up (e.g., for a button 1 double-click, the ASCE shall send button 1 down, button 1 up, button 1 down, button 1 up), with the relevant local event times. A receiving ASCE is responsible for processing that pointing device event sequence such that, where the event times fall within the local terminal double-click interval, it is interpreted as a double-click. This means that in a multipoint conference, where an ASCE is displaying shadow windows corresponding to hosted windows on multiple hosting ASCEs and the local ASCE is cooperating and in control, then the double-click time will depend on which local and/or shadow window has the input focus. + +**Table 8-95 – Three button pointing device event flags** + +| Pointing device event | Valid combinations of pointingDeviceFlags | +|-----------------------|-------------------------------------------| +| Move | Move | +| Left button down | Button 1 + down | +| Left button up | Button 1 | +| Right button down | Button 2 + down | +| Right button up | Button 2 | +| Middle button down | Button 3 + down | +| Middle button up | Button 3 | + +### 8.18.2 Keyboard events + +Depending on conductorship and control state, an ASCE may queue a keyboard event within an InputPDU when a local keyboard event occurs. A receiving ASCE shall process keyboard events with respect to the current local control state and policy. + +Keyboard events can be represented in the AS protocol as either code points or virtual keys (see below). The keyboard event is described in Table 8-96. + +**Table 8-96 – Keyboard event** + +| Parameter | Description | +|----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| eventTime | This parameter is the local ASCE time in milliseconds when this event occurred. | +| keyboardflags |

This parameter is a set of bit flags identifying and qualifying the keyboard event. Defined bit flag values are as follows:

  • • Right.
  • • Quiet.
  • • Down.
  • • Release.

The right and quiet bit flags are only valid for virtual key keyboard events. The down and release bit flags are valid for both codepoint and virtual key keyboard events. See below for further information on the interpretation of keyboard event flags.

| +| keyCode | For codepoint keyboard events, this parameter is an AS protocol code page codepoint (see clause 8.8.1). For virtual key keyboard events, this parameter is a virtual keycode (see clause 8.18.3 below). | + +**Table 8-96 – Keyboard event** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +A sending ASCE uses combinations of the down and release bit flags in the keyboardFlags parameter to indicate the following keyboard actions. + +- Key release: down and release bit flags are set. +- Key press: Neither down nor release bit flags are set. +- Key repeat: Down bit flag is set. + +A receiving ASCE: + +- processes received virtual key keyboard events with respect to the previously established keyboard modifier and toggle state, but does not interpret nor translate the virtual keycode value; +- processes received code point keyboard events by generating the appropriate series of local actions required to produce the codepoint on the local terminal. + +Where a sending ASCE can use either a codepoint or a virtual key for a particular key (e.g., AS protocol codepoint 0x41 and virtual keycode 0x41 are both uppercase A), it should send the codepoint rather than the virtual keycode. This is preferred, as AS protocol code page codepoints are independent of keyboard modifier and/or toggle state, whereas virtual keycodes are not. For example, on US PC 101 and Mac keyboards the @ (Unicode 0x26, AMPERSAND) character is shift-2 whereas on UK PC 101 keyboards it is shift-‘ (shift-quote) – and shift-2 is " (Unicode 0x22, QUOTATION MARK). Therefore, if an ASCE executing on a US PC was in a conference where peer ASCEs had a mix of UK and US keyboards and sent virtual keycodes, then typing shift-2 locally – which would produce the sequence of virtual keycode keyboard events VK\_SHIFT-down, VK\_2-down, VK\_2-up, VK\_SHIFT-up – might variously produce @ and/or " on other terminals. In contrast, if the ASCE sent codepoints, which would produce the sequence of codepoint, keyboard events 0x0026-down, 0x0026-up, each peer ASCE could take appropriate local action to produce the @. + +### 8.18.3 Virtual keycodes + +Virtual keycodes provide a hardware- and language-independent method of identifying keyboard keys. Each virtual keycode represents a unique keyboard key and also identifies the purpose of that key. Table 8-97 defines the virtual keycodes supported by the AS protocol. ASCEs shall only send InputVirtualKey keyboard events in InputPDUs using defined virtual keycodes. + +On certain terminals, keys may be duplicated (for example, shift is typically duplicated to the left and right), but are only allocated one virtual keycode (VK\_SHIFT = 0x10). Some applications are sensitive to whether end-users have pressed the left or right variant of such keys. Therefore, where an ASCE can locally distinguish between the left and right variants it should: + +- set or clear the right bit flag in the keyboardFlags parameter when sending such virtual keycode events; +- check the right bit flag in the keyboardFlags parameter when receiving virtual keycode events and take the appropriate local action to generate the corresponding local indication. + +Where an ASCE cannot distinguish between left and right variants, then it should: + +- never set the right bit flag in the keyboardFlags parameter when sending virtual keycode events; +- never check the right bit flag in the keyboardFlags parameter when receiving virtual keycode events – and therefore handle events that have the right bit flag set as if the event referenced the left variant. + +**Table 8-97 – Virtual keycodes** + +| Name | Value | Comment | +|-------------|-------|--------------------| +| VK_CANCEL | 0x03 | Break | +| VK_BACK | 0x08 | | +| VK_TAB | 0x09 | | +| VK_CLEAR | 0x0C | | +| VK_RETURN | 0x0D | | +| VK_SHIFT | 0x10 | | +| VK_CONTROL | 0x11 | | +| VK_ALT | 0x12 | Also known as menu | +| VK_PAUSE | 0x13 | | +| VK_CAPITAL | 0x14 | | +| VK_ESCAPE | 0x1B | | +| VK_SPACE | 0x20 | | +| VK_PRIOR | 0x21 | Page up | +| VK_NEXT | 0x22 | Page down | +| VK_END | 0x23 | | +| VK_HOME | 0x24 | | +| VK_LEFT | 0x25 | | +| VK_UP | 0x26 | | +| VK_RIGHT | 0x27 | | +| VK_DOWN | 0x28 | | +| VK_SELECT | 0x29 | | +| VK_SNAPSHOT | 0x2C | Print screen | +| VK_INSERT | 0x2D | | +| VK_DELETE | 0x2E | | +| VK_HELP | 0x2F | | +| VK_0 | 0x30 | Numerals... | +| VK_1 | 0x31 | | +| VK_2 | 0x32 | | +| VK_3 | 0x33 | | +| VK_4 | 0x34 | | +| VK_5 | 0x35 | | +| VK_6 | 0x36 | | +| VK_7 | 0x37 | | + +**Table 8-97 – Virtual keycodes** + +| Name | Value | Comment | +|---------------|--------------|---------------------| +| VK_8 | 0x38 | | +| VK_9 | 0x39 | | +| VK_A | 0x41 | Alphabetic... | +| VK_B | 0x42 | | +| VK_C | 0x43 | | +| VK_D | 0x44 | | +| VK_E | 0x45 | | +| VK_F | 0x46 | | +| VK_G | 0x47 | | +| VK_H | 0x48 | | +| VK_I | 0x49 | | +| VK_J | 0x4A | | +| VK_K | 0x4B | | +| VK_L | 0x4C | | +| VK_M | 0x4D | | +| VK_N | 0x4E | | +| VK_O | 0x4F | | +| VK_P | 0x50 | | +| VK_Q | 0x51 | | +| VK_R | 0x52 | | +| VK_S | 0x53 | | +| VK_T | 0x54 | | +| VK_U | 0x55 | | +| VK_V | 0x56 | | +| VK_W | 0x57 | | +| VK_X | 0x58 | | +| VK_Y | 0x59 | | +| VK_Z | 0x5A | | +| VK_LEFT_MENU | 0x5B | Left menu key | +| VK_RIGHT_MENU | 0x5C | Right menu key | +| VK_CONTEXT | 0x5D | Context menu key | +| VK_NUMPAD0 | 0x60 | Numeric pad keys... | +| VK_NUMPAD1 | 0x61 | | +| VK_NUMPAD2 | 0x62 | | +| VK_NUMPAD3 | 0x63 | | +| VK_NUMPAD4 | 0x64 | | +| VK_NUMPAD5 | 0x65 | | +| VK_NUMPAD6 | 0x66 | | + +**Table 8-97 – Virtual keycodes** + +| Name | Value | Comment | +|-------------|--------------|------------------| +| VK_NUMPAD7 | 0x67 | | +| VK_NUMPAD8 | 0x68 | | +| VK_NUMPAD9 | 0x69 | | +| VK_MULTIPLY | 0x6A | | +| VK_ADD | 0x6B | | +| VK_SUBTRACT | 0x6D | | +| VK_DECIMAL | 0x6E | | +| VK_DIVIDE | 0x6F | | +| VK_F1 | 0x70 | Function keys... | +| VK_F2 | 0x71 | | +| VK_F3 | 0x72 | | +| VK_F4 | 0x73 | | +| VK_F5 | 0x74 | | +| VK_F6 | 0x75 | | +| VK_F7 | 0x76 | | +| VK_F8 | 0x77 | | +| VK_F9 | 0x78 | | +| VK_F10 | 0x79 | | +| VK_F11 | 0x7A | | +| VK_F12 | 0x7B | | +| VK_F13 | 0x7C | | +| VK_F14 | 0x7D | | +| VK_F15 | 0x7E | | +| VK_F16 | 0x7F | | +| VK_F17 | 0x80 | | +| VK_F18 | 0x81 | | +| VK_F19 | 0x82 | | +| VK_F20 | 0x83 | | +| VK_F21 | 0x84 | | +| VK_F22 | 0x85 | | +| VK_F23 | 0x86 | | +| VK_F24 | 0x87 | | +| VK_NUMLOCK | 0x90 | Num lock | +| VK_SCROLL | 0x91 | Scroll lock | +| VK_PLUS | 0xBB | | +| VK_COMMA | 0xBC | | +| VK_MINUS | 0xBD | | +| VK_PERIOD | 0xBE | | + +**Table 8-97 – Virtual keycodes** + +| Name | Value | Comment | +|----------|-------|--------------------| +| VK_BAR | 0xE2 | Solid bar (non-US) | +| VK_ATTN | 0xF6 | | +| VK_CRSEL | 0xF7 | | +| VK_EXSEL | 0xF8 | | +| VK_EREOF | 0xF9 | | +| VK_PLAY | 0xFA | | +| VK_ZOOM | 0xFB | | +| VK_PA1 | 0xFD | | + +### 8.18.4 Keyboard state + +During an AS session, an ASCE need only send keyboard events when providing input to a remotely hosted application. It need not send keyboard events for keys typed before it became active, or when the conference is in conducted mode and it does not have conductorship privileges, or it is not in control, or it is detached. + +A sending ASCE shall ensure that the portions of the local input stream that are sent in keyboard events in InputPDUs are internally consistent. For example, suppose that the local end-user had CapsLock on before the ASCE became active in the AS session, and then takes control of a remotely hosted application and starts typing. The ASCE must precede sent keyboard events with additional keyboard events containing CapsLock down/up events, and rely on peer ASCEs to prepare their local keyboard state so that the CapsLock down/up takes effect (which may be a null operation if CapsLock was on remotely as well) to ensure that the input is capitalized on the remote system. + +The general requirement is that the sending ASCE inserts keyboard events as required into the outgoing input stream to synchronize the remote keyboard to the local keyboard state. + +During an AS session, an ASCE may receive input from multiple peer ASCEs. For example, where an ASCE is hosting an application in a multipoint conference, several peer ASCEs may provide input in turn, as the remote end-users exchange control and provide input to the hosted application. While an ASCE can rely on the sending ASCEs inserting any required state (see above), it is responsible for undoing any local keyboard state established on behalf of other peer ASCEs before processing input from a new ASCE. For example, if ASCE A is hosting the application, ASCE B is in control and has CapsLock on and control switches to ASCE C who already has NumLock on, then when ASCE A switches input from ASCE B to ASCE C, it can rely on ASCE C prefacing its input stream with a NumLock-down, NumLock-up, but is itself responsible for undoing the CapsLock state established on behalf of ASCE B. When ASCE A subsequently switches input from ASCE C back to ASCE B, it is then responsible for re-establishing the CapsLock on state on behalf of ASCE B. + +The general requirement is that a receiving ASCE is responsible for taking any local action required to synchronize the local keyboard state to that of a new input stream. + +### 8.18.5 Quiet keys + +Many terminals use special key sequences to effect actions that should not be reflected at peer ASCEs. For example, ALT-TAB is commonly used to cycle the focus around window manager windows. + +Such sequences should only have local effect, but a sending ASCE may only be able to detect them after the first event(s) in the sequence have been sent. Where this is the case, the sending ASCE should send subsequent events with the quiet bit flag set in the keyboardFlags parameter to indicate to peer ASCEs that they should undo the effect of the sequence. + +For example, an ASCE may send ALT-TAB as: ALT-down, TAB-down-quiet, TAB-up-quiet, ALT-up-quiet. + +Where a receiving ASCE detects that the quiet bit flag is set for a down event, that key and its associated up event may be discarded. Where the receiving ASCE only detects that the quiet bit flag is set after the down event for a key, then there may be local mechanisms whereby the effect of the key can be suppressed by inserting additional key events before or after the associated up event. + +For example, an ASCE may process the sent ALT-TAB sequence above as: ALT-down, discard TAB-down-quiet, discard TAB-up-quiet, insert terminal-dependent suppression events, ALT-up. + +### 8.18.6 Input synchronization event + +When an ASCE detects that a new ASCE has become active, it shall reset its sending keyboard state and shall queue an input synchronization event for sending within the next InputPDU. Thereafter, when sending input events, it shall insert input events to bring peer ASCEs up to the same keyboard state as the local terminal. + +On receipt of an input synchronization event within an InputPDU, an ASCE shall reset its receiving keyboard state. Thereafter, before receiving input from a particular peer ASCE, it can expect to receive any required keyboard state applicable to that input. + +See clause 8.4 for further information on ASCE activation and clause 8.6 for further information on synchronization. The input synchronization event is described in Table 8-98. + +**Table 8-98 – Input synchronization event** + +| Parameter | Description | +|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| eventTime | This parameter is the local ASCE time in milliseconds when this event occurred. | +| nonStandardParameters | This parameter is only allowed in the base mode of the AS protocol. It is an optional list of non-standard parameters allowed only if the corresponding non-standard capabilities are present in the negotiated capability set. | + +## 8.19 Conducted mode operation + +When a conference is in conducted mode, the rights of an ASCE to host applications and to provide input events may be restricted by the conducting node. + +When a conference enters conducted mode or when conductorship moves from one node to another, each ASCE receives a GCC-Conductor-Assign indication. Upon receipt of such an indication, no ASCE at a node other than the conducting node is permitted to host applications or provide input. + +Receipt of GCC-Conductor-Permission-Grant indications while in conducted mode grants and denies the right for ASCEs at nodes other than the conducting node to host applications and provide input. The right is granted if the permission flag parameter is TRUE. The right is denied if the permission flag parameter is set to FALSE. + +An ASCE at the conducting node of a conducted mode conference may host applications and provide input. + +In non-conducted mode, all ASCEs may host applications and provide input, subject to the conference control policy (see clauses 8.12 and 8.13). + +# 9 ASPDU definitions + +The structure of ASPDUs for the legacy and base modes of the AS protocol are specified as follows using the notation ASN.1 of [ITU-T X.680]. + +Legacy mode ASPDUs are specified in clause 9.1 and shall be encoded for transmission by applying the encoding rules defined in clause 9.3. + +Base mode ASPDUs are specified in clause 9.2 and shall be encoded for transmission by applying the BASIC ALIGNED variant of the packed encoding rules of [ITU-T X.691]. + +Both legacy and base mode ASPDUs shall be encoded and placed in the data field of MCS-Send-Data primitives, with the bit string generated by the encoding placed in the OCTET STRING used by MCS in the order such that for each octet, the leading bit is placed in the most significant bit position and the trailing bit is placed in the least significant bit position. + +## 9.1 Legacy mode ASN.1 definition + +``` +--//////////////////////////////////// +-- +-- Begin AS Definitions +-- +--//////////////////////////////////// +AS-PROTOCOL-for-legacy-mode {itu-t(0) recommendation(0) t(20) +t128(128) version(0) 2 as-protocol-for-legacy-mode(2)} +DEFINITIONS AUTOMATIC TAGS ::= +BEGIN + +-- NOTE - ===== +-- NOTE - All abstract types defined shall be exported +-- NOTE - ===== + +-- Constants +maxSourceDescriptor INTEGER ::= 48 +maxTerminalDescriptor INTEGER ::= 16 +maxFonts INTEGER ::= 700 +maxPassword INTEGER ::= 9 +maxFaceName INTEGER ::= 32 +maxTitleString INTEGER ::= 50 +maxInputEvents INTEGER ::= 50 + +-- Base Types +BitString8 ::= BIT STRING(SIZE (0..7)) +BitString16 ::= BIT STRING(SIZE (0..15)) +BitString32 ::= BIT STRING(SIZE (0..31)) +Coordinate8 ::= INTEGER(127..128) +Coordinate16 ::= INTEGER(32767..32768) +Integer4 ::= INTEGER(0..15) +Integer8 ::= INTEGER(0..255) +Integer12 ::= INTEGER(0..4095) +Integer16 ::= INTEGER(0..65535) +Integer32 ::= INTEGER(0..4294967295) +Boolean16 ::= INTEGER {false(0), true(1)} (0..65535) +UserID ::= Integer16 +ShareID ::= Integer32 +WindowID ::= Integer32 +T50String ::= OCTET STRING(SIZE (0..255)) -- T.50 String +ASString ::= OCTET STRING(SIZE (0..255)) -- AS Protocol CodePage String + +-- Bit Flag Types +BitmapCompressionCapabilityFlags ::= BIT STRING {bitmapCompressionSupported(0) +}(SIZE (0..15)) +``` + +``` + +BoundsOrderFlags ::= BIT STRING { + absoluteLeftPresent(0), absoluteTopPresent(1), absoluteRightPresent(2), + absoluteBottomPresent(3), deltaLeftPresent(4), deltaTopPresent(5), + deltaRightPresent(6), deltaBottomPresent(7)}(SIZE (0..7)) + +ControlCapabilityFlags ::= BIT STRING {allowMediatedControl(0)}(SIZE (0..15)) + +ControlOrderFlags ::= BIT STRING { + standard(0), -- Mandatory this flag is set + secondary(1), bounds(2), typeChange(3), deltaCoordinates(4)}(SIZE (0..7)) + +ExtraOrderFlags ::= BIT STRING {secondary(3)}(SIZE (0..15)) + +ExtraTextFlags ::= BIT STRING { + opaqueRectangle(1), clipToRectangle(2), deltaXPresent(15)}(SIZE (0..15)) + +FontAttributeFlags ::= BIT STRING {fixedPitch(0), fixedSize(1)}(SIZE (0..15)) + +KeyboardFlags ::= BIT STRING {right(0), quiet(12), down(14), release(15)}(SIZE (0..15)) + +OrderCapabilityFlags ::= BIT STRING { + negotiateOrderSupport(1), -- Mandatory this flag is set + cannotReceiveOrders(2)}(SIZE (0..15)) + +PointingDeviceFlags ::= BIT STRING { + move(11), button1(12), button2(13), button3(14), down(15)}(SIZE (0..15)) + +TextAttributeFlags ::= BIT STRING { + italic(2), underline(3), strikeouts(4), useBaselineStart(8)}(SIZE (0..15)) + +TextCapabilityFlags ::= BIT STRING { + checkFontAspect(0), allowDeltaXSimulation(5), checkFontSignatures(7), + useBaselineStart(9)}(SIZE (0..15)) + +WindowAttributeFlags ::= BIT STRING { + minimized(0), taggable(1), hosted(2), shadow(3), local(4), topmost(5), + windowManagerMinimized(16), windowManagerInvisible(17)}(SIZE (0..31)) + +-- General Types +ApplicationAction ::= INTEGER { + notifyHostedApplications(1), unhostApplication(2)}(0..65535) + +BackgroundMixMode ::= INTEGER {transparent(1), opaque(2)}(0..65535) + +BitmapData ::= CHOICE { + uncompressedBitmapData OCTET STRING, + compressedBitmapData CompressedBitmapData +} + +Brush ::= SEQUENCE { + originX Integer8 OPTIONAL, + originY Integer8 OPTIONAL, + style BrushStyle OPTIONAL, + hatch BrushHatch OPTIONAL, + pattern OCTET STRING(SIZE (7)) OPTIONAL +} + +BrushHatch ::= CHOICE {style HatchStyle, + patternZero Integer8 +} + +BrushStyle ::= INTEGER {solid(0), null(1), hatched(2), pattern(3)}(0..255) + +``` + +``` + +Color ::= SEQUENCE {red Integer8, + green Integer8, + blue Integer8 +} + +ColorQuad ::= SEQUENCE { + blue Integer8, + green Integer8, + red Integer8, + padloctet Integer8 +} + +ColorPointerAttribute ::= SEQUENCE { + cacheIndex Integer16, + hotSpot Point16, + width Integer16, + height Integer16, + lengthANDMask Integer16, + -- length in octets of AND mask in colorPointerData + lengthXORMask Integer16, + -- length in octets of XOR mask in colorPointerData + colorPointerData OCTET STRING +} + +CompressedBitmapData ::= SEQUENCE { + pad2octets Integer16(0), + mainBodySize Integer16, + rowSize Integer16, + uncompressedSize Integer16, + compressedBitmap OCTET STRING +} + +ControlAction ::= INTEGER { + requestControl(1), detach(3), grantControl(2), cooperate(4)}(0..65535) + +ControlPriority ::= INTEGER {always(1), never(2), confirm(3)}(0..65535) + +Coordinate ::= CHOICE {absolute Coordinate16, + delta Coordinate8 +} + +DesktopSaveAction ::= INTEGER {desktopSave(0), desktopRestore(1)}(0..255) + +FontAttribute ::= SEQUENCE { + faceName T50String(SIZE (1..maxFaceName)), + fontFlags FontAttributeFlags, + averageWidth Integer16, + height Integer16, + aspectX Integer16, + aspectY Integer16, + signature1 Integer8, + signature2 Integer8, + signature3 Integer16, + codePage FontCodePage, + ascent Integer16 +} + +FontCodePage ::= INTEGER {allCodePoints(0), coreCodePoints(255)}(0..65535) + +HatchStyle ::= INTEGER { + horizontal(0), vertical(1), forward(2), backward(3), cross(4), diagonal(5) +}(0..255) + +InputMessageType ::= INTEGER { + +``` + +``` + +inputSynchronize(0), inputCodePoint(1), inputVirtualKey(2), +inputPointingDevice(32769) -- ('8001'H)--}(0..65535) + +MediatedControlAction ::= INTEGER { + takeControlRequest(1), passControlRequest(2), detachRequest(3), + confirmTakeResponse(5), denyTakeResponse(6), confirmDetachResponse(7), + denyDetachResponse(8), denyPassResponse(9), remoteDetachRequest(10), + denyRemoteDetachRequest(11)}(0..65535) + +MonoPointerAttribute ::= SEQUENCE { + hotSpot Point16, + width Integer16, + height Integer16, + lengthPointerData Integer16, + -- length in octets of monoPointerData + monoPointerData OCTET STRING +} + +OSMajorType ::= INTEGER { + unspecified(0), windows(1), os2(2), macintosh(3), unix(4)}(0..65535) + +OSMinorType ::= INTEGER { + unspecified(0), windows-31x(1), windows-95(2), windows-NT(3), os2-V21(4), + power-pc(5), macintosh(6), native-XServer(7), pseudo-XServer(8)}(0..65535) + +PDUType ::= INTEGER { + confirmActivePDU(3), dataPDU(7), deactivateAllPDU(6), deactivateOtherPDU(4), + deactivateSelfPDU(5), demandActivePDU(1), requestActivePDU(2)}(0..15) + +PDUType2 ::= INTEGER { + application(25), control(20), font(11), input(28), mediatedControl(29), + pointer(27), remoteShare(30), synchronize(31), update(2), + updateCapability(32), windowActivation(23), windowList(24)}(0..255) + +PDUTypeFlow ::= INTEGER {flowResponsePDU(66), flowStopPDU(67), flowTestPDU(65)}(0..255) + +Pen ::= SEQUENCE { + style PenStyle OPTIONAL, + width Integer8(1) OPTIONAL, + color Color OPTIONAL +} + +PenStyle ::= ENUMERATED { + solid(0), dashed(1), dotted(2), dash-dot(3), dash-dot-dot(4), null(5) +} + +Point16 ::= SEQUENCE {x Coordinate16, + y Coordinate16 +} + +PointerType ::= INTEGER { + cachedPointer(7), colorPointer(6), monoPointer(2), pointerPosition(3), + systemPointer(1)}(0..65535) + +PrimaryOrderType ::= INTEGER { + destinationBlt(0), patternBlt(1), screenBlt(2), memoryBlt(13), + memoryThreeWayBlt(14), text(5), extendedText(6), frame(9), rectangle(7), + line(8), opaqueRectangle(10), desktopSave(11), desktopOrigin(32)}(0..255) + +Rectangle16 ::= SEQUENCE { + left Coordinate16, + top Coordinate16, + right Coordinate16, + +``` + +``` + + bottom Coordinate16 +} + +RemoteShareAction ::= INTEGER { + requestRemoteShare(1), confirmRemoteShare(2), denyRemoteShare(3)}(0..65535) + +RemoteShareDenial ::= INTEGER { + incorrectPassword(1), remoteShareNotEnabled(2), + remoteShareInOperationIncoming(3), remoteShareInOperationOutgoing(4) +}(0..65535) + +ROP2 ::= INTEGER { + r2BLACK(1), r2DPon(2), r2DPna(3), r2Pn(4), r2PDna(5), r2Dn(6), r2DPx(7), + r2DPan(8), r2DPa(9), r2DPxn(10), r2D(11), r2DPno(12), r2P(13), r2PDno(14), + r2DPo(15), r2WHITE(16)}(0..255) + +ROP3 ::= INTEGER { + r3BLACK(0), -- ('00'H) + r3DPSon(1), -- ('01'H) + r3DPSona(2), -- ('02'H) + r3Pson(3), -- ('03'H) + r3SDPona(4), -- ('04'H) + r3DPon(5), -- ('05'H) + r3PDSxon(6), -- ('06'H) + r3PDSaon(7), -- ('07'H) + r3SDPnaa(8), -- ('08'H) + r3PDSxon(9), -- ('09'H) + r3DPna(10), -- ('0A'H) + r3PSDnaon(11), -- ('0B'H) + r3SPna(12), -- ('0C'H) + r3PDSnaon(13), -- ('0D'H) + r3PDSonon(14), -- ('0E'H) + r3Pn(15), -- ('0F'H) + r3PDSona(16), -- ('10'H) + r3DSon(17), -- ('11'H) + r3SDPxnon(18), -- ('12'H) + r3SDPaon(19), -- ('13'H) + r3DPSxon(20), -- ('14'H) + r3DPSaon(21), -- ('15'H) + r3PSDPSanaxx(22), -- ('16'H) + r3SSPxDSxaxn(23), -- ('17'H) + r3SPxPDxa(24), -- ('18'H) + r3SDPSanaxn(25), -- ('19'H) + r3PDSPaon(26), -- ('1A'H) + r3SDPSxaxn(27), -- ('1B'H) + r3PSDPaon(28), -- ('1C'H) + r3DSPDxaxn(29), -- ('1D'H) + r3PDSox(30), -- ('1E'H) + r3PDSoan(31), -- ('1F'H) + r3DPSnaa(32), -- ('20'H) + r3SDPxon(33), -- ('21'H) + r3DSna(34), -- ('22'H) + r3SPDnaon(35), -- ('23'H) + r3SPxDSxa(36), -- ('24'H) + r3PDSPanaxn(37), -- ('25'H) + r3SDPSaon(38), -- ('26'H) + r3SDPSxnox(39), -- ('27'H) + r3DPSxa(40), -- ('28'H) + r3PSDPSaoxxn(41), -- ('29'H) + r3DPSana(42), -- ('2A'H) + r3SSPxPDxaxn(43), -- ('2B'H) + r3SPDSoax(44), -- ('2C'H) + r3PSDnox(45), -- ('2D'H) + r3PSDPxox(46), -- ('2E'H) + +``` + +r3PSDnoan(47), -- ('2F'H) + r3PSna(48), -- ('30'H) + r3SDPnaon(49), -- ('31'H) + r3SDPSoox(50), -- ('32'H) + r3Sn(51), -- ('33'H) + r3SPDSaox(52), -- ('34'H) + r3SPDSxnox(53), -- ('35'H) + r3SDPox(54), -- ('36'H) + r3SDPoan(55), -- ('37'H) + r3PSDPoax(56), -- ('38'H) + r3SPDnox(57), -- ('39'H) + r3SPDSxox(58), -- ('3A'H) + r3SPDnoan(59), -- ('3B'H) + r3PSx(60), -- ('3C'H) + r3SPDSonox(61), -- ('3D'H) + r3SPDSnaox(62), -- ('3E'H) + r3PSan(63), -- ('3F'H) + r3PSDnaa(64), -- ('40'H) + r3DPSxon(65), -- ('41'H) + r3SDxPDxa(66), -- ('42'H) + r3SPDSanaxn(67), -- ('43'H) + r3SDna(68), -- ('44'H) + r3DPSnaon(69), -- ('45'H) + r3DPSDaox(70), -- ('46'H) + r3SPDPxaxn(71), -- ('47'H) + r3SDPxa(72), -- ('48'H) + r3PDSPDaoxxn(73), -- ('49'H) + r3DPSDoax(74), -- ('4A'H) + r3PDSnox(75), -- ('4B'H) + r3SDPana(76), -- ('4C'H) + r3SSPxDSxoxn(77), -- ('4D'H) + r3PDSPxox(78), -- ('4E'H) + r3PDSnoan(79), -- ('4F'H) + r3PDna(80), -- ('50'H) + r3DSPnaon(81), -- ('51'H) + r3DPSDaox(82), -- ('52'H) + r3SPDSxaxn(83), -- ('53'H) + r3DPSonon(84), -- ('54'H) + r3Dn(85), -- ('55'H) + r3DPSox(86), -- ('56'H) + r3DPSoan(87), -- ('57'H) + r3PDSPoax(88), -- ('58'H) + r3DPSnox(89), -- ('59'H) + r3DPx(90), -- ('5A'H) + r3DPSDonox(91), -- ('5B'H) + r3DPSDxox(92), -- ('5C'H) + r3DPSnoan(93), -- ('5D'H) + r3DPSDnaox(94), -- ('5E'H) + r3DPan(95), -- ('5F'H) + r3PDSxa(96), -- ('60'H) + r3DSPDSaoxxn(97), -- ('61'H) + r3DSPDoax(98), -- ('62'H) + r3SDPnox(99), -- ('63'H) + r3SDPSoax(100), -- ('64'H) + r3DSPnox(101), -- ('65'H) + r3DSx(102), -- ('66'H) + r3SDPSonox(103), -- ('67'H) + r3DSPDSonoxxn(104), -- ('68'H) + r3PDSxxn(105), -- ('69'H) + r3DPSax(106), -- ('6A'H) + r3PSDPSoaxxn(107), -- ('6B'H) + r3SDPax(108), -- ('6C'H) + r3PDSPDaoxxn(109), -- ('6D'H) + r3SDPSnoax(110), -- ('6E'H) + +``` + +r3PDSxnan(111), -- ('6F'H) +r3PDSana(112), -- ('70'H) +r3SSDxPDxaxn(113), -- ('71'H) +r3SDPSxox(114), -- ('72'H) +r3SDPnoan(115), -- ('73'H) +r3DSPDxox(116), -- ('74'H) +r3DSPnoan(117), -- ('75'H) +r3SDPSnaox(118), -- ('76'H) +r3DSan(119), -- ('77'H) +r3PDSax(120), -- ('78'H) +r3DSPDSoaxxn(121), -- ('79'H) +r3DPSDnoax(122), -- ('7A'H) +r3SDPxnan(123), -- ('7B'H) +r3SPDSnoax(124), -- ('7C'H) +r3DPSxnan(125), -- ('7D'H) +r3SPxDSxo(126), -- ('7E'H) +r3DPSaan(127), -- ('7F'H) +r3DPSaa(128), -- ('80'H) +r3SPxDSxon(129), -- ('81'H) +r3DPSxna(130), -- ('82'H) +r3SPDSnoaxn(131), -- ('83'H) +r3SDPxna(132), -- ('84'H) +r3PDSPnoaxn(133), -- ('85'H) +r3DSPDSoaxx(134), -- ('86'H) +r3PDSaxn(135), -- ('87'H) +r3DSa(136), -- ('88'H) +r3SDPSnaoxn(137), -- ('89'H) +r3DSPnoa(138), -- ('8A'H) +r3DSPDxoxn(139), -- ('8B'H) +r3SDPnoa(140), -- ('8C'H) +r3SDPSxoxn(141), -- ('8D'H) +r3SSDxPDxax(142), -- ('8E'H) +r3PDSanan(143), -- ('8F'H) +r3PDSxna(144), -- ('90'H) +r3SDPSnoaxn(145), -- ('91'H) +r3DSPDSoaxx(146), -- ('92'H) +r3SPDaxn(147), -- ('93'H) +r3PSPDSoaxx(148), -- ('94'H) +r3DPSaxn(149), -- ('95'H) +r3DPSxx(150), -- ('96'H) +r3PSPDPSonoxx(151), -- ('97'H) +r3SDPSonoxn(152), -- ('98'H) +r3DSxn(153), -- ('99'H) +r3DPSnax(154), -- ('9A'H) +r3SDPSoaxn(155), -- ('9B'H) +r3SPDnax(156), -- ('9C'H) +r3DSPDoaxn(157), -- ('9D'H) +r3DSPDSoaxx(158), -- ('9E'H) +r3PDSxan(159), -- ('9F'H) +r3DPa(160), -- ('A0'H) +r3PDSPnaoxn(161), -- ('A1'H) +r3DPSnoa(162), -- ('A2'H) +r3DSPDxoxn(163), -- ('A3'H) +r3PDSPOnoxn(164), -- ('A4'H) +r3PDxn(165), -- ('A5'H) +r3DSPnax(166), -- ('A6'H) +r3PDSPOaxn(167), -- ('A7'H) +r3DPSoa(168), -- ('A8'H) +r3DPSoxn(169), -- ('A9'H) +r3D(170), -- ('AA'H) +r3DPSono(171), -- ('AB'H) +r3SPDSxax(172), -- ('AC'H) +r3DSPDaoxn(173), -- ('AD'H) +r3DSPnao(174), -- ('AE'H) + +``` + +``` + +r3DPno(175), -- ('AF'H) +r3PDSnoa(176), -- ('B0'H) +r3PDSPxoxn(177), -- ('B1'H) +r3SSPxDSxox(178), -- ('B2'H) +r3SDPanan(179), -- ('B3'H) +r3PSDnax(180), -- ('B4'H) +r3DPSPDoaxn(181), -- ('B5'H) +r3DPSPDpaoxx(182), -- ('B6'H) +r3SDPxan(183), -- ('B7'H) +r3PDSPxax(184), -- ('B8'H) +r3DPSDaoxn(185), -- ('B9'H) +r3DPSnao(186), -- ('BA'H) +r3DSno(187), -- ('BB'H) +r3SPDSanax(188), -- ('BC'H) +r3SDxPDxan(189), -- ('BD'H) +r3DPSxo(190), -- ('BE'H) +r3DPSano(191), -- ('BF'H) +r3PSa(192), -- ('C0'H) +r3SPDSnaoxn(193), -- ('C1'H) +r3SPDSonoxn(194), -- ('C2'H) +r3PSxn(195), -- ('C3'H) +r3SPDnoa(196), -- ('C4'H) +r3SPDSxoxn(197), -- ('C5'H) +r3SDPnax(198), -- ('C6'H) +r3PSDPoaxn(199), -- ('C7'H) +r3SDPoa(200), -- ('C8'H) +r3SPDoxn(201), -- ('C9'H) +r3DPSDxax(202), -- ('CA'H) +r3SPDSaoxn(203), -- ('CB'H) +r3S(204), -- ('CC'H) +r3SDPono(205), -- ('CD'H) +r3SDPnao(206), -- ('CE'H) +r3SPno(207), -- ('CF'H) +r3PSDnoa(208), -- ('D0'H) +r3PDSPxoxn(209), -- ('D1'H) +r3PDSnax(210), -- ('D2'H) +r3SPDSaoxn(211), -- ('D3'H) +r3SSPxPDxax(212), -- ('D4'H) +r3DPSanan(213), -- ('D5'H) +r3PSDPSaoxx(214), -- ('D6'H) +r3DPSxan(215), -- ('D7'H) +r3PDSPxax(216), -- ('D8'H) +r3SDPSaoxn(217), -- ('D9'H) +r3DPSDanax(218), -- ('DA'H) +r3SPxDSxan(219), -- ('DB'H) +r3SPDnao(220), -- ('DC'H) +r3SDno(221), -- ('DD'H) +r3SDPxo(222), -- ('DE'H) +r3SDPano(223), -- ('DF'H) +r3PDSoa(224), -- ('E0'H) +r3PDSoxn(225), -- ('E1'H) +r3DSPDxax(226), -- ('E2'H) +r3PSDPaoxn(227), -- ('E3'H) +r3SDPSxax(228), -- ('E4'H) +r3PDSPaoxn(229), -- ('E5'H) +r3SDPSanax(230), -- ('E6'H) +r3SPxPDxan(231), -- ('E7'H) +r3SSPxDSxax(232), -- ('E8'H) +r3DPSDPSanaxxn(233), -- ('E9'H) +r3DPSao(234), -- ('EA'H) +r3DPSxno(235), -- ('EB'H) +r3SDPao(236), -- ('EC'H) +r3SDPxno(237), -- ('ED'H) +r3DSo(238), -- ('EE'H) + +``` + +``` + +r3SDPnoo(239), -- ('EF'H) +r3P(240), -- ('F0'H) +r3PDSono(241), -- ('F1'H) +r3PDSnao(242), -- ('F2'H) +r3PSno(243), -- ('F3'H) +r3PSDnao(244), -- ('F4'H) +r3PDno(245), -- ('F5'H) +r3PDSxo(246), -- ('F6'H) +r3PDSano(247), -- ('F7'H) +r3PDSao(248), -- ('F8'H) +r3PDSxno(249), -- ('F9'H) +r3DPo(250), -- ('FA'H) +r3DPSnoo(251), -- ('FB'H) +r3PSo(252), -- ('FC'H) +r3PSDnoo(253), -- ('FD'H) +r3DPSoo(254), -- ('FE'H) +r3WHITE(255) -- ('FF'H) --} (0..255) + +SecondaryOrderType ::= INTEGER { + cacheBitmapUncompressed(0), cacheColorTable(1), cacheBitmapCompressed(2) +} (0..255) + +StreamID ::= INTEGER { + streamLowPriority(1), streamMediumPriority(2), streamHighPriority(4) +} (0..255) + +SynchronizeMessageType ::= INTEGER {synchronize(1)} (0..65535) + +SystemPointerType ::= INTEGER {nullPointer(0), defaultPointer(32512) + -- ('00007F00'H) --} (0..4294967295) + +UpdateType ::= INTEGER {orders(0), bitmap(1), palette(2), synchronize(3) +} (0..65535) + +WindowActivationAction ::= INTEGER { + localWindowActive(1), hostedWindowActive(2), hostedWindowInvisible(3), + pointerDeviceCapture(4), + activateWindow(32769), -- ('8001'H) + closeWindow(32770), -- ('8002'H) + restoreWindow(32771), -- ('8003'H) + windowManagerMenu(32772), -- ('8004'H) + activationHelpKey(32785), -- ('8011'H) + activationHelpIndexKey(32786), -- ('8012'H) + activationHelpExtendedKey(32787) -- ('8013'H) --} (0..65535) + +WindowAttribute ::= SEQUENCE { + windowID WindowID, + windowExtra Integer32, + windowOwner WindowID, + windowFlags WindowAttributeFlags, + windowRectangle Rectangle16 +} + +WindowListMessageType ::= INTEGER {updateWindowList(1)} (0..65535) + +WindowTitle ::= CHOICE { + noTitle Integer8(255), + titleString T50String(SIZE (1..maxTitleString)) +} + +-- Capability Types +CapabilitySetType ::= INTEGER { + bitmapCacheCapabilitySet(4), bitmapCapabilitySet(2), + colorCacheCapabilitySet(10), controlCapabilitySet(5), + +``` + +``` + +generalCapabilitySet(1), orderCapabilitySet(3), pointerCapabilitySet(8), +activationCapabilitySet(7), shareCapabilitySet(9)}(0..65535) + +``` + +``` + +GeneralCapabilitySet ::= SEQUENCE { + capabilitySetType CapabilitySetType(generalCapabilitySet), + lengthCapability Integer16, + -- length of capability set in octets + -- (including type and length parameters) + osMajorType OSMajorType, + osMinorType OSMinorType, + protocolVersion Integer16(512), -- ('0200'H) + pad2octetsA Integer16, + generalCompressionTypes Integer16, + pad2octetsB Integer16, + updatecapabilityFlag Boolean16, + remoteUnshareFlag Boolean16, + generalCompressionLevel Integer16, + pad2octetsC Integer16 +} + +``` + +``` + +BitmapCapabilitySet ::= SEQUENCE { + capabilitySetType CapabilitySetType(bitmapCapabilitySet), + lengthCapability Integer16, + -- length of capability set in octets + -- (including type and length parameters) + preferredBitsPerPixel Integer16(1..8), + receive1BitPerPixelFlag Boolean16, + receive4BitsPerPixelFlag Boolean16, + receive8BitsPerPixelFlag Boolean16, + desktopWidth Integer16, + desktopHeight Integer16, + pad2octetsA Integer16, + desktopResizeFlag Boolean16, + bitmapCompressionType BitmapCompressionCapabilityFlags, + pad2octetsC Integer16 +} + +``` + +``` + +OrderCapabilitySet ::= SEQUENCE { + capabilitySetType CapabilitySetType(orderCapabilitySet), + lengthCapability Integer16, + -- length of capability set in octets + -- (including type and length parameters) + terminalDescriptor T50String(SIZE (1..maxTerminalDescriptor)), + pad4octetsA Integer32(0), + desktopXGranularity Integer16, + desktopYGranularity Integer16, + pad2octetsA Integer16(0), + maximumOrderLevel Integer16, + numberFonts Integer16(1..maxFonts), + orderFlags OrderCapabilityFlags, + orderSupport + SEQUENCE {destinationBltSupport Integer8, + patternBltSupport Integer8, + screenBltSupport Integer8, + memoryBltSupport Integer8, + memoryThreeWayBltSupport Integer8, + textSupport Integer8, + extendedTextSupport Integer8, + rectangleSupport Integer8, + lineSupport Integer8, + frameSupport Integer8, + opaqueRectangleSupport Integer8, + desktopSaveSupport Integer8, + undefinedOrder12 Integer8(0), + +``` + +``` + + undefinedOrder13 Integer8 (0), + undefinedOrder14 Integer8 (0), + undefinedOrder15 Integer8 (0), + undefinedOrder16 Integer8 (0), + undefinedOrder17 Integer8 (0), + undefinedOrder18 Integer8 (0), + undefinedOrder19 Integer8 (0), + undefinedOrder20 Integer8 (0), + undefinedOrder21 Integer8 (0), + undefinedOrder22 Integer8 (0), + undefinedOrder23 Integer8 (0), + undefinedOrder24 Integer8 (0), + undefinedOrder25 Integer8 (0), + undefinedOrder26 Integer8 (0), + undefinedOrder27 Integer8 (0), + undefinedOrder28 Integer8 (0), + undefinedOrder29 Integer8 (0), + undefinedOrder30 Integer8 (0), + undefinedOrder31 Integer8 (0)}, + textFlags TextCapabilityFlags, + pad2octetsB Integer16 (0), + pad4octetsB Integer32 (0), + desktopSaveSize Integer32, + pad4octetsC Integer32 (0) +} + +BitmapCacheCapabilitySet ::= SEQUENCE { + capabilitySetType CapabilitySetType(bitmapCacheCapabilitySet), + lengthCapability Integer16, + -- length of capability set in octets + -- (including type and length parameters) + pad4octetsA Integer32 (0), + pad4octetsB Integer32 (0), + pad4octetsC Integer32 (0), + pad4octetsD Integer32 (0), + pad4octetsE Integer32 (0), + pad4octetsF Integer32 (0), + cache1Entries Integer16, + cache1MaximumCellSize Integer16 (256..16384), + cache2Entries Integer16, + cache2MaximumCellSize Integer16 (256..16384), + cache3Entries Integer16, + cache3MaximumCellSize Integer16 (256..16384) +} + +ColorCacheCapabilitySet ::= SEQUENCE { + capabilitySetType CapabilitySetType(colorCacheCapabilitySet), + lengthCapability Integer16, + -- length of capability set in octets + -- (including type and length parameters) + colorTablecacheSize Integer16 (1..255), + pad2octetsA Integer16 +} + +ActivationCapabilitySet ::= SEQUENCE { + capabilitySetType CapabilitySetType(activationCapabilitySet), + lengthCapability Integer16, + -- length of capability set in octets + -- (including type and length parameters) + helpKeyFlag Boolean16, + helpIndexKeyFlag Boolean16, + helpExtendedKeyFlag Boolean16, + windowActivateFlag Boolean16 +} + +``` + +``` + +ControlCapabilitySet ::= SEQUENCE { + capabilitySetType CapabilitySetType(controlCapabilitySet), + lengthCapability Integer16, + -- length of capability set in octets + -- (including type and length parameters) + controlFlags ControlCapabilityFlags, + remoteDetachFlag Boolean16, + controlInterest ControlPriority, + detachInterest ControlPriority +} + +PointerCapabilitySet ::= SEQUENCE { + capabilitySetType CapabilitySetType(pointerCapabilitySet), + lengthCapability Integer16, + -- length of capability set in octets + -- (including type and length parameters) + colorPointerFlag Boolean16, + pointerCacheSize Integer16(1..500) +} + +ShareCapabilitySet ::= SEQUENCE { + capabilitySetType CapabilitySetType(shareCapabilitySet), + lengthCapability Integer16, + -- length of capability set in octets + -- (including type and length parameters) + nodeID Integer32 +} + +NonStandardCapabilitySet ::= SEQUENCE { + capabilitySetType Integer16, + -- defined by ASCE + lengthCapability Integer16, + -- length of capability set in octets + -- (including type and length parameters) + nonStandardParameters OCTET STRING +} + +CombinedCapabilities ::= SEQUENCE { + numberCapabilities Integer16, + -- number of capabilities in combinedCapabilities set + pad2octets Integer16(0), + combinedCapabilities + SET {generalCapabilitySet GeneralCapabilitySet, + bitmapCapabilitySet BitmapCapabilitySet, + orderCapabilitySet OrderCapabilitySet, + bitmapCacheCapabilitySet BitmapCacheCapabilitySet, + colorCacheCapabilitySet ColorCacheCapabilitySet, + activationCapabilitySet ActivationCapabilitySet, + controlCapabilitySet ControlCapabilitySet, + pointerCapabilitySet PointerCapabilitySet, + shareCapabilitySet ShareCapabilitySet, + nonStandardCapabilitySet NonStandardCapabilitySet OPTIONAL} +} + +UpdateCapabilitySet ::= CHOICE {bitmapCapabilitySet BitmapCapabilitySet +} + +-- Input Types +InputEvent ::= CHOICE { + pointingDeviceEvent PointingDeviceEvent, + keyboardEvent KeyboardEvent, + synchronizeEvent SynchronizeEvent +} + +``` + +``` + +KeyboardEvent ::= SEQUENCE { + eventTime Integer32, + messageType InputMessageType(inputCodePoint | inputVirtualKey), + keyboardFlags KeyboardFlags, + keyCode Integer16 + -- AS protocol code page codepoint or virtual keycode +} + +PointingDeviceEvent ::= SEQUENCE { + eventTime Integer32, + messageType InputMessageType(inputPointingDevice), + pointingDeviceFlags PointingDeviceFlags, + pointingDeviceX Coordinate16, + pointingDeviceY Coordinate16 +} + +SynchronizeEvent ::= SEQUENCE { + eventTime Integer32, + messageType InputMessageType(inputSynchronize) +} + +-- Common Header Types +PrimaryOrderHeader ::= SEQUENCE { + controlFlags ControlOrderFlags, + orderType PrimaryOrderType OPTIONAL, + encodingFlags SEQUENCE (SIZE (1..3)) OF BitString8, + boundsFlags BoundsOrderFlags OPTIONAL, + boundsLeft Coordinate OPTIONAL, + boundsTop Coordinate OPTIONAL, + boundsRight Coordinate OPTIONAL, + boundsBottom Coordinate OPTIONAL +} + +SecondaryOrderHeader ::= SEQUENCE { + controlFlags ControlOrderFlags, + orderLength Integer16, + -- length in octets, from and including orderType, minus eight + extraFlags ExtraOrderFlags, + orderType SecondaryOrderType +} + +ShareControlHeader ::= SEQUENCE { + totalLength Integer16(0..32767), + protocolVersion Integer4(1), + pduType PDUType, + padloctet Integer8(0), + pduSource UserID +} + +ShareDataHeader ::= SEQUENCE { + shareControlHeader ShareControlHeader, -- PDUType = dataPDU + shareID ShareID, + padloctet Integer8(0), + streamID StreamID, + uncompressedLength Integer16, + pduType2 PDUType2, + generalCompressedType Integer8, + generalCompressedLength Integer16 +} + +-- Order Types +DestinationBltOrder ::= SEQUENCE { + header PrimaryOrderHeader, -- PrimaryOrderType = destinationBlt + +``` + +``` + +destLeft Coordinate OPTIONAL, +destTop Coordinate OPTIONAL, +destWidth Coordinate OPTIONAL, +destHeight Coordinate OPTIONAL, +rop3 ROP3 OPTIONAL +} + +PatternBltOrder ::= SEQUENCE { + header PrimaryOrderHeader, -- PrimaryOrderType = patternBlt + destLeft Coordinate OPTIONAL, + destTop Coordinate OPTIONAL, + destWidth Coordinate OPTIONAL, + destHeight Coordinate OPTIONAL, + rop3 ROP3 OPTIONAL, + backgroundColor Color OPTIONAL, + foregroundColor Color OPTIONAL, + brush Brush OPTIONAL +} + +ScreenBltOrder ::= SEQUENCE { + header PrimaryOrderHeader, -- PrimaryOrderType = screenBlt + destLeft Coordinate OPTIONAL, + destTop Coordinate OPTIONAL, + destWidth Coordinate OPTIONAL, + destHeight Coordinate OPTIONAL, + rop3 ROP3 OPTIONAL, + sourceX Coordinate OPTIONAL, + sourceY Coordinate OPTIONAL +} + +CacheBitmapOrder ::= SEQUENCE { + header SecondaryOrderHeader, -- SecondaryOrderType = + -- cacheBitmapUncompressed | cacheBitmapCompressed + cacheId Integer8(0..2), + padloctet Integer8(0), + bitmapWidth Integer8, + bitmapHeight Integer8, + bitmapBitsPerPel Integer8(1 | 4 | 8), + bitmapLength Integer16, + -- length of bitmapData in octets (after any compression) + cacheIndex Integer16, + bitmapData BitmapData +} + +CacheColorTableOrder ::= SEQUENCE { + header SecondaryOrderHeader, -- SecondaryOrderType = cacheColorTable + cacheIndex Integer8, + numberColors Integer16(16 | 256), + colorTable SEQUENCE (SIZE (16 | 256)) OF ColorQuad +} + +MemoryBltOrder ::= SEQUENCE { + header PrimaryOrderHeader, -- PrimaryOrderType = memoryBlt + colorTableCacheIndex Integer8 OPTIONAL, + bitmapCacheID Integer8 OPTIONAL, + destLeft Coordinate OPTIONAL, + destTop Coordinate OPTIONAL, + destWidth Coordinate OPTIONAL, + destHeight Coordinate OPTIONAL, + rop3 ROP3 OPTIONAL, + sourceX Coordinate OPTIONAL, + sourceY Coordinate OPTIONAL, + bitmapCacheIndex Integer16 OPTIONAL +} + +``` + +``` + +MemoryThreeWayBlitOrder ::= SEQUENCE { + header PrimaryOrderHeader, + -- PrimaryOrderType = memoryThreeWayBlt + colorTableCacheIndex Integer8 OPTIONAL, + bitmapCacheID Integer8 OPTIONAL, + destLeft Coordinate OPTIONAL, + destTop Coordinate OPTIONAL, + destWidth Coordinate OPTIONAL, + destHeight Coordinate OPTIONAL, + rop3 ROP3 OPTIONAL, + sourceX Coordinate OPTIONAL, + sourceY Coordinate OPTIONAL, + backgroundColor Color OPTIONAL, + foregroundColor Color OPTIONAL, + brush Brush OPTIONAL, + bitmapCacheIndex Integer16 OPTIONAL +} + +TextOrder ::= SEQUENCE { + header PrimaryOrderHeader, -- PrimaryOrderType = text + backMixMode BackgroundMixMode OPTIONAL, + startX Coordinate OPTIONAL, + startY Coordinate OPTIONAL, + backgroundColor Color OPTIONAL, + foregroundColor Color OPTIONAL, + extraSpacing Integer16 OPTIONAL, + totalBreakSpacing Integer16 OPTIONAL, + breakCount Integer16 OPTIONAL, + fontHeight Integer16 OPTIONAL, + fontWidth Integer16 OPTIONAL, + fontWeight Integer16 OPTIONAL, + textFlags TextAttributeFlags OPTIONAL, + fontID Integer16 OPTIONAL, + numberCodePoints Integer8(1..255) OPTIONAL, + -- number of codepoints in codePointList + codePointList ASString(SIZE (1..255)) OPTIONAL +} + +ExtendedTextOrder ::= SEQUENCE { + header PrimaryOrderHeader, -- PrimaryOrderType = extendedText + backMixMode BackgroundMixMode OPTIONAL, + startX Coordinate OPTIONAL, + startY Coordinate OPTIONAL, + backgroundColor Color OPTIONAL, + foregroundColor Color OPTIONAL, + extraSpacing Integer16 OPTIONAL, + totalBreakSpacing Integer16 OPTIONAL, + breakCount Integer16 OPTIONAL, + fontHeight Integer16 OPTIONAL, + fontWidth Integer16 OPTIONAL, + fontWeight Integer16 OPTIONAL, + textFlags1 TextAttributeFlags OPTIONAL, + fontID Integer16 OPTIONAL, + textFlags2 ExtraTextFlags OPTIONAL, + clipLeft Coordinate OPTIONAL, + clipTop Coordinate OPTIONAL, + clipRight Coordinate OPTIONAL, + clipBottom Coordinate OPTIONAL, + numberCodePoints Integer8(1..255) OPTIONAL, + -- number of codepoints in codePointList; where deltaX values + -- are present maximum number of codepoints is 127 + codePointList ASString(SIZE (1..255)) OPTIONAL, + numberDeltaX Integer8(1..127) OPTIONAL, + +``` + +``` + +-- number of deltaX values in deltaXList +deltaXList SEQUENCE (SIZE (1..127)) OF Coordinate OPTIONAL +} + +FrameOrder ::= SEQUENCE { + header PrimaryOrderHeader, -- PrimaryOrderType = frame + destLeft Coordinate OPTIONAL, + destTop Coordinate OPTIONAL, + destWidth Coordinate OPTIONAL, + destHeight Coordinate OPTIONAL, + rop3 ROP3 OPTIONAL, + backgroundColor Color OPTIONAL, + foregroundColor Color OPTIONAL, + brush Brush OPTIONAL +} + +RectangleOrder ::= SEQUENCE { + header PrimaryOrderHeader, -- PrimaryOrderType = rectangle + backMixMode BackgroundMixMode OPTIONAL, + destLeft Coordinate OPTIONAL, + destTop Coordinate OPTIONAL, + destRight Coordinate OPTIONAL, + destBottom Coordinate OPTIONAL, + backgroundColor Color OPTIONAL, + foregroundColor Color OPTIONAL, + brush Brush OPTIONAL, + rop2 ROP2 OPTIONAL, + pen Pen OPTIONAL +} + +OpaqueRectangleOrder ::= SEQUENCE { + header PrimaryOrderHeader, -- PrimaryOrderType = opaqueRectangle + destLeft Coordinate OPTIONAL, + destTop Coordinate OPTIONAL, + destWidth Coordinate OPTIONAL, + destHeight Coordinate OPTIONAL, + color Color OPTIONAL +} + +LineOrder ::= SEQUENCE { + header PrimaryOrderHeader, -- PrimaryOrderType = line + backMixMode BackgroundMixMode OPTIONAL, + startX Coordinate OPTIONAL, + startY Coordinate OPTIONAL, + endX Coordinate OPTIONAL, + endY Coordinate OPTIONAL, + backgroundColor Color OPTIONAL, + rop2 ROP2 OPTIONAL, + pen Pen OPTIONAL +} + +DesktopSaveOrder ::= SEQUENCE { + header PrimaryOrderHeader, -- PrimaryOrderType = desktopSave + saveOffset Integer32 OPTIONAL, + destLeft Coordinate OPTIONAL, + destTop Coordinate OPTIONAL, + destWidth Coordinate OPTIONAL, + destHeight Coordinate OPTIONAL, + action DesktopSaveAction OPTIONAL +} + +DesktopOriginOrder ::= SEQUENCE { + header PrimaryOrderHeader, -- PrimaryOrderType = desktopOrigin + desktopLeft Coordinate OPTIONAL, + +``` + +``` + + desktopTop Coordinate OPTIONAL +} + +``` + +``` + +PrimaryOrder ::= CHOICE { + destinationBlt DestinationBltOrder, + patternBlt PatternBltOrder, + screenBlt ScreenBltOrder, + memoryBlt MemoryBltOrder, + memoryThreeWayBlt MemoryThreeWayBltOrder, + text TextOrder, + extendedText ExtendedTextOrder, + frame FrameOrder, + rectangle RectangleOrder, + line LineOrder, + opaqueRectangle OpaqueRectangleOrder, + desktopSave DesktopSaveOrder, + desktopOrigin DesktopOriginOrder +} + +``` + +``` + +SecondaryOrder ::= CHOICE { + cacheBitmap CacheBitmapOrder, + cacheColorTable CacheColorTableOrder +} + +``` + +``` + +UpdateOrder ::= CHOICE { + primaryOrder PrimaryOrder, + secondaryOrder SecondaryOrder +} + +``` + +``` + +--//////////////////////////////////// +-- +-- Begin AS PDU Definitions +-- +--//////////////////////////////////// + +``` + +``` + +ApplicationPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, -- PDUType2 = application + action ApplicationAction, + numberApplications Integer16, + windowID WindowID +} + +``` + +``` + +ConfirmActivePDU ::= SEQUENCE { + shareControlHeader ShareControlHeader, -- PDUType = confirmActivePDU + shareID ShareID, + originatorID UserID, + lengthSourceDescriptor Integer16(1..maxSourceDescriptor), + -- length of sourceDescriptor in octets + -- (including null terminator) + lengthCombinedCapabilities Integer16, + -- length of combinedCapabilities in octets + sourceDescriptor T50String(SIZE (1..maxSourceDescriptor)), + combinedCapabilities CombinedCapabilities +} + +``` + +``` + +ControlPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, -- PDUType2 = control + action ControlAction, + grantID UserID, + controlID Integer32(0..2147483647) +} + +``` + +``` + +DeactivateAllPDU ::= SEQUENCE { + shareControlHeader ShareControlHeader, -- PDUType = deactivateAllPDU + shareID ShareID, +} + +``` + +``` + +lengthSourceDescriptor Integer16(1..maxSourceDescriptor), +-- length of sourceDescriptor in octets +-- (including null terminator) +sourceDescriptor T50String(SIZE (1..maxSourceDescriptor)) +} + +DeactivateOtherPDU ::= SEQUENCE { + shareControlHeader ShareControlHeader, -- PDUType = deactivateOtherPDU + shareID ShareID, + deactivateID UserID, + lengthSourceDescriptor Integer16(1..maxSourceDescriptor), +-- length of sourceDescriptor in octets +-- (including null terminator) + sourceDescriptor T50String(SIZE (1..maxSourceDescriptor)) +} + +DeactivateSelfPDU ::= SEQUENCE { + shareControlHeader ShareControlHeader, -- PDUType = deactivateSelfPDU + shareID ShareID +} + +DemandActivePDU ::= SEQUENCE { + shareControlHeader ShareControlHeader, -- PDUType = demandActivePDU + shareID ShareID, + lengthSourceDescriptor Integer16(1..maxSourceDescriptor), +-- length of sourceDescriptor in octets +-- (including null terminator) + lengthCombinedCapabilities Integer16, +-- length of combinedCapabilities in octets + sourceDescriptor T50String(SIZE (1..maxSourceDescriptor)), + combinedCapabilities CombinedCapabilities +} + +FlowPDU ::= SEQUENCE { + flowMarker Integer16(32768), -- ('8000'H), +-- distinguishes FlowPDUs from ASPDUs +-- containing ShareControlHeaders + pad8bits Integer8(0), + pduTypeFlow PDUTypeFlow(flowResponsePDU | flowStopPDU | flowTestPDU), + flowIdentifier Integer8(0..127), + flowNumber Integer8, +-- shall be zero for PDUType FlowStopPDU + pduSource UserID +-- MCS User ID of sending ASCE +} + +FontPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, -- PDUType2 = font + numberFonts Integer16(1..maxFonts), +-- number of FontAttributes in fontList + entrySize Integer16, + fontList SEQUENCE (SIZE (1..maxFonts)) OF FontAttribute +} + +InputPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, -- PDUType2 = input + numberEvents Integer16, +-- number of InputEvents in eventList + pad2octets Integer16(0), + eventList SEQUENCE (SIZE (1..maxInputEvents)) OF InputEvent +} + +MediatedControlPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, -- PDUType2 = mediatedControl + +``` + +``` + + action MediatedControlAction, + passControlFlag Boolean16, + sendingReference Integer16, + originatorReference Integer16, + originatorID UserID +} + +PointerPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, -- PDUType2 = pointer + messageType PointerMessageType, + pad2octets Integer16(0), + pointerData + CHOICE {systemPointerType SystemPointerType, + monoPointerAttribute MonoPointerAttribute, + colorPointerAttribute ColorPointerAttribute, + cachedPointerIndex Integer16, + pointerPosition Point16} +} + +RemoteSharePDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, -- PDUType2 = remoteShare + action RemoteShareAction, + additionalData + CHOICE {requestingID UserID, + pad2octets Integer16(0), + denialCode RemoteShareDenial}, + encryptedPassword OCTET STRING(SIZE (1..maxPassword)) +} + +RequestActivePDU ::= SEQUENCE { + shareControlHeader ShareControlHeader, -- PDUType = requestActivePDU + lengthSourceDescriptor Integer16(1..maxSourceDescriptor), + -- length of sourceDescriptor in octets + -- (including null terminator) + lengthCombinedCapabilities Integer16, + -- length of combinedCapabilities in octets + sourceDescriptor T50String(SIZE (1..maxSourceDescriptor)), + combinedCapabilities CombinedCapabilities +} + +SynchronizePDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, -- PDUType2 = synchronize + messageType SynchronizeMessageType, + targetUser UserID +} + +UpdateBitmapPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, -- PDUType2=update + updateType UpdateType(bitmap), + pad2octets Integer16(0), + destLeft Coordinate16, + destTop Coordinate16, + destRight Coordinate16, + destBottom Coordinate16, + width Integer16, + height Integer16, + bitsPerPixel Integer16(1 | 4 | 8), + compressedFlag Boolean16, + bitmapLength Integer16, + -- length in octets of bitmapData (after any compression) + bitmapData BitmapData +} + +UpdateCapabilityPDU ::= SEQUENCE { + +``` + +``` + +shareDataHeader ShareDataHeader, -- PDUType2 = updateCapability +updateCapabilitySet UpdateCapabilitySet +} + +``` + +``` + +UpdateOrdersPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, -- PDUType2 = update + updateType UpdateType(orders), + pad2octetsA Integer16(0), + numberOrders Integer16, + -- number of UpdateOrders in orderList + pad2octetsB Integer16(0), + orderList SEQUENCE OF UpdateOrder +} + +``` + +``` + +UpdatePalettePDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, -- PDUType2 = update + updateType UpdateType(palette), + pad2octets Integer16(0), + numberColors Integer32(16 | 256), + palette SEQUENCE (SIZE (16 | 256)) OF Color +} + +``` + +``` + +UpdateSynchronizePDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, -- PDUType2 = update + updateType UpdateType(synchronize), + pad2octets Integer16(0) +} + +``` + +``` + +WindowActivationPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, -- PDUType2 = windowActivation + action WindowActivationAction, + activationID Integer16, + activationWindow WindowID, + activationPoint Point16 +} + +``` + +``` + +WindowListPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, -- PDUType2 = windowList + messageType WindowListMessageType, + pad2octetsA Integer16, + numberWindows Integer16, + -- number of WindowAttributes/Titles in lists + listTime Integer16, + listID Integer16, + pad2octetsB Integer16, + windowAttributeList SEQUENCE OF WindowAttribute, + windowTitleList SEQUENCE OF WindowTitle +} + +``` + +``` + +SharePDU ::= CHOICE { + applicationPDU ApplicationPDU, + confirmActivePDU ConfirmActivePDU, + controlPDU ControlPDU, + deactivateAllPDU DeactivateAllPDU, + deactivateOtherPDU DeactivateOtherPDU, + deactivateSelfPDU DeactivateSelfPDU, + demandActivePDU DemandActivePDU, + flowPDU FlowPDU, + fontPDU FontPDU, + inputPDU InputPDU, + mediatedControlPDU MediatedControlPDU, + pointerPDU PointerPDU, + remoteSharePDU RemoteSharePDU, + requestActivePDU RequestActivePDU, +} + +``` + +``` + +synchronizePDU SynchronizePDU, +updateCapabilityPDU UpdateCapabilityPDU, +updateBitmapPDU UpdateBitmapPDU, +updateOrdersPDU UpdateOrdersPDU, +updateSynchronizePDU UpdateSynchronizePDU, +updatePalettePDU UpdatePalettePDU, +windowActivationPDU WindowActivationPDU, +windowListPDU WindowListPDU +} + +``` + +``` + +-- +-- +-- End AS Definitions +-- +-- +END + +``` + +## 9.2 Base mode ASN.1 definition + +``` + +-- +-- +-- Begin AS Definitions +-- +-- The following base mode ASN.1 definitions are encoded using the +-- BASIC ALIGNED variant of the Packed Encoding Rules of Recommendation +-- ITU-T X.691. +-- +-- +AS-PROTOCOL-for-PER-encoding {itu-t(0) recommendation(0) t(20) +t128(128) version(0) 2 as-protocol-for-per-encoding(1)} +DEFINITIONS AUTOMATIC TAGS ::= +BEGIN +IMPORTS + H221NonStandardIdentifier, Key, NonStandardParameter, UserID + FROM GCC-PROTOCOL {itu-t(0) recommendation(0) t(20) t124(124) +version(0) 2 asn1Modules(2) gcc-protocol(1)}; + +-- NOTE: +-- NOTE: All abstract types defined shall be exported +-- NOTE: +-- Base Types +Coordinate8 ::= INTEGER(-128..127) +Coordinate16 ::= INTEGER(-32768..32767) +Integer8 ::= INTEGER(0..255) +Integer12 ::= INTEGER(0..4095) +Integer16 ::= INTEGER(0..65535) +Integer32 ::= INTEGER(0..4294967295) +Signed16 ::= INTEGER(-32768..32767) +ShareID ::= Integer32 +WindowID ::= Integer32 +T50String ::= OCTET STRING(SIZE (0..255)) -- T.50 String + +ASString ::= OCTET STRING(SIZE (0..255)) -- AS Protocol CodePage String + +-- Bit Flag Types +ExtraTextFlags ::= BIT STRING { + opaqueRectangle(1), clipToRectangle(2), deltaXPresent(15)} + +FontAttributeFlags ::= BIT STRING {fixedPitch(0), fixedSize(1)} + +KeyboardFlags ::= BIT STRING {right(0), quiet(12), down(14), release(15)} + +PointingDeviceFlags ::= BIT STRING { + move(11), button1(12), button2(13), button3(14), down(15)} + +``` + +``` + +TextAttributeFlags ::= BIT STRING { + italic(2), underline(3), strikeout(4), baselineStart(8)} + +WindowAttributeFlags ::= BIT STRING { + minimized(0), taggable(1), hosted(2), shadow(3), local(4), topmost(5), + windowManagerMinimized(16), windowManagerInvisible(17)} + +-- General Types +ActivateWindowRequest ::= SEQUENCE { + activationWindow WindowID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +ActivationHelpKeyRequest ::= SEQUENCE { + activationWindow WindowID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +ActivationHelpIndexKeyRequest ::= SEQUENCE { + activationWindow WindowID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +ActivationHelpExtendedKeyRequest ::= SEQUENCE { + activationWindow WindowID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +BackgroundMixMode ::= CHOICE { + transparent [1] NULL, + opaque [2] NULL, + nonStandardBackgroundMixMode NonStandardParameter, + -- Subject to capability negotiation. + ... +} + +BitmapData ::= CHOICE { + uncompressedBitmapData [0] OCTET STRING, + compressedBitmapData [2] CompressedBitmapData, + nonStandardBitmapData NonStandardParameter, + -- Subject to capability negotiation. + ... +} + +Brush ::= SEQUENCE { + originX Integer8 OPTIONAL, + originY Integer8 OPTIONAL, + style BrushStyle OPTIONAL, + hatch BrushHatch OPTIONAL, + pattern OCTET STRING(SIZE (7)) OPTIONAL, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +BrushHatch ::= CHOICE { + +``` + +``` + + style HatchStyle, + patternZero Integer8, + nonStandardBrushHatch NonStandardParameter, + -- Subject to capability negotiation. + ... +} + +BrushStyle ::= CHOICE { + solid [0] NULL, + null [1] NULL, + hatched [2] NULL, + pattern [3] NULL, + nonStandardBrushStyle NonStandardParameter, + -- Subject to capability negotiation. + ... +} + +CloseWindowRequest ::= SEQUENCE { + activationWindow WindowID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +Color ::= SEQUENCE { + c1 Integer8, + -- either R of RGB or subject to capability negotiation. + c2 Integer8, + -- either G of RGB or subject to capability negotiation. + c3 Integer8 + -- either B of RGB or subject to capability negotiation +} + +ColorAccuracyEnhancementRGB ::= CHOICE { + predefinedRGBSpace CHOICE {nonStandardRGBSpace NonStandardParameter, + ...}, + generalRGBParameters + SEQUENCE {gamma REAL(0..MAX) OPTIONAL, + -- Gamma value of the color space + colorTemperature INTEGER(0..MAX) OPTIONAL, + -- Color temperature of the white point assumed by + -- the color space (in degrees Kelvin) + primaries + SEQUENCE {red ColorCIExyChromaticity, + -- CIE xy chromaticity coordinate of the red primary + green ColorCIExyChromaticity, + -- CIE xy chromaticity coordinate of the green primary + blue ColorCIExyChromaticity + -- CIE xy chromaticity coordinate of the blue primary + } OPTIONAL, + ...}, + ... +} + +ColorCIExyChromaticity ::= SEQUENCE { + x REAL(0..1), -- CIE normalized x component + y REAL(0..1) -- CIE normalized y component +} + +ColorPalette ::= CHOICE { + paletteRGB + SEQUENCE {palette SEQUENCE (SIZE (16 | 256)) OF ColorRGB, + enhancement ColorAccuracyEnhancementRGB OPTIONAL, + ...}, +} + +``` + +``` + + nonStandardPalette NonStandardParameter, + ... +} + +ColorPointerAttribute ::= SEQUENCE { + cacheIndex Integer16, + hotSpot Point16, + width Integer16, + height Integer16, + colorPointerData OCTET STRING, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +ColorRGB ::= SEQUENCE {red Integer8, + green Integer8, + blue Integer8 +} + +ColorSpaceSpecifier ::= CHOICE { + colorSpaceDefault NULL, + -- Default color space is RGB without accuracy enhancement + colorSpaceRGB ColorAccuracyEnhancementRGB, + nonStandardColorSpace NonStandardParameter, + -- Subject to capability negotiation. + ... +} + +CompressedBitmapData ::= SEQUENCE { + mainBodySize Integer16, + rowSize Integer16, + uncompressedSize Integer16, + compressedBitmap OCTET STRING, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +ConfirmDetachResponse ::= SEQUENCE { + passControlFlag BOOLEAN, + sendingReference Integer16, + originatorReference Integer16, + originatorID UserID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +ConfirmRemoteShare ::= SEQUENCE { + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +ConfirmTakeResponse ::= SEQUENCE { + passControlFlag BOOLEAN, + sendingReference Integer16, + originatorReference Integer16, + originatorID UserID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +``` + +``` + +ControlPriority ::= CHOICE { + always [1] NULL, + never [2] NULL, + confirm [3] NULL, + nonStandardControlPriority NonStandardParameter, + -- Subject to capability negotiation. + ... +} + +Cooperate ::= SEQUENCE { + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +Coordinate ::= CHOICE { + absolute Coordinate16, + delta Coordinate8, + nonStandardCoordinate NonStandardParameter, + -- Subject to capability negotiation. + ... +} + +DesktopSaveAction ::= CHOICE { + desktopSave [0] NULL, + desktopRestore [1] NULL, + nonStandardDesktopSaveAction NonStandardParameter, + -- Subject to capability negotiation. + ... +} + +DenyDetachResponse ::= SEQUENCE { + passControlFlag BOOLEAN, + sendingReference Integer16, + originatorReference Integer16, + originatorID UserID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +DenyPassResponse ::= SEQUENCE { + passControlFlag BOOLEAN, + sendingReference Integer16, + originatorReference Integer16, + originatorID UserID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +DenyTakeResponse ::= SEQUENCE { + passControlFlag BOOLEAN, + sendingReference Integer16, + originatorReference Integer16, + originatorID UserID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +DenyRemoteDetachResponse ::= SEQUENCE { + passControlFlag BOOLEAN, + sendingReference Integer16, + +``` + +``` + + originatorReference Integer16, + originatorID UserID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +DenyRemoteShare ::= CHOICE { + remoteShareDenial RemoteShareDenial, + nonStandardDenial NonStandardParameter, + -- Subject to capability negotiation. + ... +} + +Detach ::= SEQUENCE { + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +DetachRequest ::= SEQUENCE { + passControlFlag BOOLEAN, + sendingReference Integer16, + originatorID UserID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +FontAttribute ::= SEQUENCE { + faceName T50String, + fontFlags FontAttributeFlags, + averageWidth Integer16, + height Integer16, + aspectX Integer16, + aspectY Integer16, + signature1 Integer8, + signature2 Integer8, + signature3 Integer16, + codePage FontCodePage, + ascent Integer16, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +FontCodePage ::= CHOICE { + allCodePoints [0] NULL, + coreCodePoints [255] NULL, + nonStandardFontCodePage NonStandardParameter, + -- Subject to capability negotiation. + ... +} + +GeneralCompressionSpecifier ::= CHOICE { + v42bisCompression V42bisCompression, + nonStandardCompression NonStandardParameter, + ... +} + +GrantControl ::= SEQUENCE { + grantID UserID, + controlID INTEGER(0..2147483647), + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + +``` + +``` + + -- Subject to capability negotiation. + ... +} + +HatchStyle ::= CHOICE { + horizontal [0] NULL, + vertical [1] NULL, + forward [2] NULL, + backward [3] NULL, + cross [4] NULL, + diagonal [5] NULL, + nonStandardHatchStyle NonStandardParameter, + -- Subject to capability negotiation. + ... +} + +HostedWindowActiveIndication ::= SEQUENCE { + activationID Integer16, + activationWindow WindowID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +HostedWindowInvisibleIndication ::= SEQUENCE { + activationID Integer16, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +LocalWindowActiveIndication ::= SEQUENCE { + activationID Integer16, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +MonoPointerAttribute ::= SEQUENCE { + hotSpot Point16, + width Integer16, + height Integer16, + monoPointerData OCTET STRING, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +NotifyHostedApplications ::= SEQUENCE { + numberApplications Integer16, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +PassControlRequest ::= SEQUENCE { + passControlFlag BOOLEAN, + sendingReference Integer16, + originatorID UserID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +``` + +``` + +Pen ::= SEQUENCE { + style PenStyle OPTIONAL, + width Integer8(1) OPTIONAL, + color Color OPTIONAL, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +PenStyle ::= CHOICE { + solid [0] NULL, + dashed [1] NULL, + dotted [2] NULL, + dash-dot [3] NULL, + dash-dot-dot [4] NULL, + null [5] NULL, + nonStandardPenStyle NonStandardParameter, + -- Subject to capability negotiation. + ... +} + +Point16 ::= SEQUENCE {x Coordinate16, + y Coordinate16 +} + +PointerDeviceCaptureIndication ::= SEQUENCE { + activationID Integer16, + activationWindow WindowID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +Rectangle16 ::= SEQUENCE { + left Coordinate16, + top Coordinate16, + right Coordinate16, + bottom Coordinate16 +} + +RemoteDetachRequest ::= SEQUENCE { + passControlFlag BOOLEAN, + sendingReference Integer16, + originatorID UserID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +RemoteShareDenial ::= CHOICE { + incorrectPassword [1] NULL, + remoteShareNotEnabled [2] NULL, + remoteShareInOperationIncoming [3] NULL, + remoteShareInOperationOutgoing [4] NULL, + nonStandardRemoteShareDenial NonStandardParameter, + -- Subject to capability negotiation. + ... +} + +RequestControl ::= SEQUENCE { + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +``` + +``` + +RequestRemoteShare ::= SEQUENCE { + requestingID UserID, + encryptedPassword OCTET STRING, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +RestoreWindowRequest ::= SEQUENCE { + activationWindow WindowID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +ROP2 ::= INTEGER { + r2BLACK(1), r2DPon(2), r2DPna(3), r2Pn(4), r2PDna(5), r2Dn(6), r2DPx(7), + r2DPan(8), r2DPa(9), r2DPxn(10), r2D(11), r2DPno(12), r2P(13), r2PDno(14), + r2DPo(15), r2WHITE(16)} (0..255) + +ROP3 ::= INTEGER { + r3BLACK(0), -- ('00'H) + r3DPSon(1), -- ('01'H) + r3DPSona(2), -- ('02'H) + r3PSON(3), -- ('03'H) + r3SDPona(4), -- ('04'H) + r3DPon(5), -- ('05'H) + r3PDSxnon(6), -- ('06'H) + r3PDSaon(7), -- ('07'H) + r3SDPnaa(8), -- ('08'H) + r3PDSxon(9), -- ('09'H) + r3DPna(10), -- ('0A'H) + r3PSDnaon(11), -- ('0B'H) + r3SPna(12), -- ('0C'H) + r3PDSnaon(13), -- ('0D'H) + r3PDSonon(14), -- ('0E'H) + r3Pn(15), -- ('0F'H) + r3PDSona(16), -- ('10'H) + r3DSon(17), -- ('11'H) + r3SDPxnon(18), -- ('12'H) + r3SDPaon(19), -- ('13'H) + r3DPSxnon(20), -- ('14'H) + r3DPSaon(21), -- ('15'H) + r3PSDPSanaxx(22), -- ('16'H) + r3SSPxDSxaxn(23), -- ('17'H) + r3SPxPDxa(24), -- ('18'H) + r3SDPSanaxn(25), -- ('19'H) + r3PDSPaon(26), -- ('1A'H) + r3SDPSxaxn(27), -- ('1B'H) + r3PSDPaon(28), -- ('1C'H) + r3DSDPxaxn(29), -- ('1D'H) + r3PDSox(30), -- ('1E'H) + r3PDSaon(31), -- ('1F'H) + r3DPSnaa(32), -- ('20'H) + r3SDPxon(33), -- ('21'H) + r3DSna(34), -- ('22'H) + r3SPDnaon(35), -- ('23'H) + r3SPxDSxa(36), -- ('24'H) + r3PDSPanaxn(37), -- ('25'H) + r3SDPSaon(38), -- ('26'H) + r3SDPSxnox(39), -- ('27'H) + r3DPSxa(40), -- ('28'H) + r3PSDPSaon(41), -- ('29'H) + r3DPSana(42), -- ('2A'H) + +``` + +r3SSPxPDxaxn(43), -- ('2B'H) +r3SPDSoax(44), -- ('2C'H) +r3PSDnox(45), -- ('2D'H) +r3PSDPxox(46), -- ('2E'H) +r3PSDnoan(47), -- ('2F'H) +r3PSna(48), -- ('30'H) +r3SDPnaon(49), -- ('31'H) +r3SDPSoox(50), -- ('32'H) +r3Sn(51), -- ('33'H) +r3SPDSaox(52), -- ('34'H) +r3SPDSxnox(53), -- ('35'H) +r3SDPox(54), -- ('36'H) +r3SDPoan(55), -- ('37'H) +r3PSDPoax(56), -- ('38'H) +r3SPDnox(57), -- ('39'H) +r3SPDSxox(58), -- ('3A'H) +r3SPDnoan(59), -- ('3B'H) +r3PSx(60), -- ('3C'H) +r3SPDSonox(61), -- ('3D'H) +r3SPDSnaox(62), -- ('3E'H) +r3PSan(63), -- ('3F'H) +r3PSDnaa(64), -- ('40'H) +r3DPSxon(65), -- ('41'H) +r3SDxPDxa(66), -- ('42'H) +r3SPDSanaxn(67), -- ('43'H) +r3SDna(68), -- ('44'H) +r3DPSnaon(69), -- ('45'H) +r3DSPDaox(70), -- ('46'H) +r3PSDPxaxn(71), -- ('47'H) +r3SDPxa(72), -- ('48'H) +r3PDSPDOaxxn(73), -- ('49'H) +r3DPSDoax(74), -- ('4A'H) +r3PDSnox(75), -- ('4B'H) +r3SDPana(76), -- ('4C'H) +r3SSPxDSxoxn(77), -- ('4D'H) +r3PDSPxox(78), -- ('4E'H) +r3PDSnoan(79), -- ('4F'H) +r3PDna(80), -- ('50'H) +r3DSPnaon(81), -- ('51'H) +r3DPSDaox(82), -- ('52'H) +r3SPDSxaxn(83), -- ('53'H) +r3DPSonon(84), -- ('54'H) +r3Dn(85), -- ('55'H) +r3DPSox(86), -- ('56'H) +r3DPSoan(87), -- ('57'H) +r3PDSPoax(88), -- ('58'H) +r3DPSnox(89), -- ('59'H) +r3DPx(90), -- ('5A'H) +r3DPSDonox(91), -- ('5B'H) +r3DPSDxox(92), -- ('5C'H) +r3DPSnoan(93), -- ('5D'H) +r3DPSDnaox(94), -- ('5E'H) +r3DPan(95), -- ('5F'H) +r3PDSxa(96), -- ('60'H) +r3DSPDSaoxxn(97), -- ('61'H) +r3DSPDoax(98), -- ('62'H) +r3SDPnox(99), -- ('63'H) +r3SDPSoax(100), -- ('64'H) +r3SDSPnox(101), -- ('65'H) +r3DSx(102), -- ('66'H) +r3SDPSonox(103), -- ('67'H) +r3DSPDSonoxxn(104), -- ('68'H) +r3PDSxxn(105), -- ('69'H) +r3DPSax(106), -- ('6A'H) + +r3PSDPSoaxxn(107), -- ('6B'H) + r3SDPax(108), -- ('6C'H) + r3PDSPDOaxxn(109), -- ('6D'H) + r3SDPSnoax(110), -- ('6E'H) + r3PDSxnan(111), -- ('6F'H) + r3PDSana(112), -- ('70'H) + r3SSDxPDxaxn(113), -- ('71'H) + r3SDPSxox(114), -- ('72'H) + r3SDPnoan(115), -- ('73'H) + r3DSPDxox(116), -- ('74'H) + r3DSPnoan(117), -- ('75'H) + r3SDPSnaox(118), -- ('76'H) + r3DSan(119), -- ('77'H) + r3PDSax(120), -- ('78'H) + r3DSPDSoaxxn(121), -- ('79'H) + r3DPSDnoax(122), -- ('7A'H) + r3SDPxnan(123), -- ('7B'H) + r3SPDSnoax(124), -- ('7C'H) + r3DPSxnan(125), -- ('7D'H) + r3SPxDSxo(126), -- ('7E'H) + r3DPSaan(127), -- ('7F'H) + r3DPSaa(128), -- ('80'H) + r3SPxDSxon(129), -- ('81'H) + r3DPSxna(130), -- ('82'H) + r3SPDSnoaxn(131), -- ('83'H) + r3SDPxna(132), -- ('84'H) + r3PDSPnoaxn(133), -- ('85'H) + r3DSPDSoaxx(134), -- ('86'H) + r3PDSaxn(135), -- ('87'H) + r3DSa(136), -- ('88'H) + r3SDPSnaoxn(137), -- ('89'H) + r3DSPnoa(138), -- ('8A'H) + r3DSPDxoxn(139), -- ('8B'H) + r3SDPnoa(140), -- ('8C'H) + r3SDPSxoxn(141), -- ('8D'H) + r3SSDxPDxax(142), -- ('8E'H) + r3PDSanan(143), -- ('8F'H) + r3PDSxna(144), -- ('90'H) + r3SDPSnoaxn(145), -- ('91'H) + r3DSPSDPoaxx(146), -- ('92'H) + r3SPDaxn(147), -- ('93'H) + r3PSDPSoaxx(148), -- ('94'H) + r3DPSaxn(149), -- ('95'H) + r3DPSxx(150), -- ('96'H) + r3PSDPSonoxx(151), -- ('97'H) + r3SDPSonoxn(152), -- ('98'H) + r3DSxn(153), -- ('99'H) + r3DPSnax(154), -- ('9A'H) + r3SDPSoaxn(155), -- ('9B'H) + r3SPDnax(156), -- ('9C'H) + r3DSPDnoaxn(157), -- ('9D'H) + r3DSPDSoaxx(158), -- ('9E'H) + r3PDSxan(159), -- ('9F'H) + r3DPa(160), -- ('A0'H) + r3PDSPnaoxn(161), -- ('A1'H) + r3DPSnoa(162), -- ('A2'H) + r3DSPSDxoxn(163), -- ('A3'H) + r3PDSPonoxn(164), -- ('A4'H) + r3PDxn(165), -- ('A5'H) + r3DSPnax(166), -- ('A6'H) + r3PDSPoaxn(167), -- ('A7'H) + r3DPSoa(168), -- ('A8'H) + r3DPSoxn(169), -- ('A9'H) + r3D(170), -- ('AA'H) + +r3DPSono(171), -- ('AB'H) +r3SPDSxax(172), -- ('AC'H) +r3DPSDaoxn(173), -- ('AD'H) +r3DSPnao(174), -- ('AE'H) +r3DPno(175), -- ('AF'H) +r3PDSnoa(176), -- ('B0'H) +r3PDSPxoxn(177), -- ('B1'H) +r3SSPxDSxox(178), -- ('B2'H) +r3SDPanan(179), -- ('B3'H) +r3PSDnax(180), -- ('B4'H) +r3DPSDoaxn(181), -- ('B5'H) +r3DPSDPaoxx(182), -- ('B6'H) +r3SDPxan(183), -- ('B7'H) +r3PSDPxax(184), -- ('B8'H) +r3DPSDaoxn(185), -- ('B9'H) +r3DPSnao(186), -- ('BA'H) +r3DSno(187), -- ('BB'H) +r3SPDSanax(188), -- ('BC'H) +r3SDxPDxan(189), -- ('BD'H) +r3DPSxo(190), -- ('BE'H) +r3DPSano(191), -- ('BF'H) +r3PSa(192), -- ('C0'H) +r3SPDSnaoxn(193), -- ('C1'H) +r3SPDSonoxn(194), -- ('C2'H) +r3PSxn(195), -- ('C3'H) +r3SPDnoa(196), -- ('C4'H) +r3SPDSxoxn(197), -- ('C5'H) +r3SDPnax(198), -- ('C6'H) +r3PSDPoaxn(199), -- ('C7'H) +r3SDPoa(200), -- ('C8'H) +r3SPDoxn(201), -- ('C9'H) +r3DPSDxax(202), -- ('CA'H) +r3SPDSaoxn(203), -- ('CB'H) +r3S(204), -- ('CC'H) +r3SDPono(205), -- ('CD'H) +r3SDPnao(206), -- ('CE'H) +r3SPno(207), -- ('CF'H) +r3PSDnoa(208), -- ('D0'H) +r3PSDPxoxn(209), -- ('D1'H) +r3PDSnax(210), -- ('D2'H) +r3SPDSaoxn(211), -- ('D3'H) +r3SSPxPDxax(212), -- ('D4'H) +r3DPSanan(213), -- ('D5'H) +r3PSDPSaoxx(214), -- ('D6'H) +r3DPSxan(215), -- ('D7'H) +r3PDSPxax(216), -- ('D8'H) +r3SDPSaoxn(217), -- ('D9'H) +r3DPSDanax(218), -- ('DA'H) +r3SPxDSxan(219), -- ('DB'H) +r3SPDnao(220), -- ('DC'H) +r3SDno(221), -- ('DD'H) +r3SDPxox(222), -- ('DE'H) +r3SDPano(223), -- ('DF'H) +r3PDSoa(224), -- ('E0'H) +r3PDSoxn(225), -- ('E1'H) +r3DPSDxax(226), -- ('E2'H) +r3PSDPaoxn(227), -- ('E3'H) +r3SDPSxax(228), -- ('E4'H) +r3PDSPaoxn(229), -- ('E5'H) +r3SDPSanax(230), -- ('E6'H) +r3SPxPDxan(231), -- ('E7'H) +r3SSPxDSxax(232), -- ('E8'H) +r3DPSDPSanaxxn(233), -- ('E9'H) +r3DPSao(234), -- ('EA'H) + +``` + +r3DPSxno(235), -- ('EB'H) +r3SDPao(236), -- ('EC'H) +r3SDPxno(237), -- ('ED'H) +r3DSo(238), -- ('EE'H) +r3SDPnoo(239), -- ('EF'H) +r3P(240), -- ('F0'H) +r3PDSono(241), -- ('F1'H) +r3PDSnao(242), -- ('F2'H) +r3PSno(243), -- ('F3'H) +r3PSDnao(244), -- ('F4'H) +r3PDno(245), -- ('F5'H) +r3PDSxo(246), -- ('F6'H) +r3PDSano(247), -- ('F7'H) +r3PDSao(248), -- ('F8'H) +r3PDSxno(249), -- ('F9'H) +r3DPo(250), -- ('FA'H) +r3DPSnoo(251), -- ('FB'H) +r3PSo(252), -- ('FC'H) +r3PSDnoo(253), -- ('FD'H) +r3DPSoo(254), -- ('FE'H) +r3WHITE(255) -- ('FF'H)--}(0..255) +SystemPointerType ::= CHOICE { + null [0] NULL, + default [12512] NULL, + nonStandardSystemPointerValue NonStandardParameter, + -- Subject to capability negotiation. + ... +} + +TakeControlRequest ::= SEQUENCE { + passControlFlag BOOLEAN, + sendingReference Integer16, + originatorReference Integer16, + originatorID UserID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +UnhostApplication ::= SEQUENCE { + windowID WindowID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +V42bisCompression ::= SEQUENCE { + p1 INTEGER(512..65535) OPTIONAL, + p2 INTEGER(6..250) OPTIONAL, + ... +} + +WindowAttribute ::= SEQUENCE { + windowID WindowID, + windowExtra Integer32, + windowOwner WindowID, + windowFlags WindowAttributeFlags, + windowRectangle Rectangle16, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +WindowManagerMenuRequest ::= SEQUENCE { + +``` + +``` + +activationWindow WindowID, +activationPoint Point16, +nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, +-- Subject to capability negotiation. +... +} + +WindowTitle ::= CHOICE { + noTitle Integer8(255), + titleString T50String, + nonStandardWindowTitle NonStandardParameter, +-- Subject to capability negotiation. + ... +} + +-- Input Types +InputEvent ::= CHOICE { + pointingDeviceEvent [12769] PointingDeviceEvent, + codePointEvent [1] CodePointEvent, + virtualKeyEvent [2] VirtualKeyEvent, + synchronizeEvent [0] SynchronizeEvent, + nonStandardInputEvent NonStandardParameter, +-- Subject to capability negotiation. + ... +} + +CodePointEvent ::= SEQUENCE { + eventTime Integer32, + keyboardFlags KeyboardFlags, + codePoint Integer16, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, +-- Subject to capability negotiation. + ... +} + +VirtualKeyEvent ::= SEQUENCE { + eventTime Integer32, + keyboardFlags KeyboardFlags, + virtualKey Integer16, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, +-- Subject to capability negotiation. + ... +} + +PointingDeviceEvent ::= SEQUENCE { + eventTime Integer32, + pointingDeviceFlags PointingDeviceFlags, + pointingDeviceX Coordinate16, + pointingDeviceY Coordinate16, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, +-- Subject to capability negotiation. + ... +} + +SynchronizeEvent ::= SEQUENCE { + eventTime Integer32, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, +-- Subject to capability negotiation. + ... +} + +-- Common Header Types +PrimaryOrderHeader ::= SEQUENCE { + boundsLeft Coordinate OPTIONAL, + +``` + +``` + + boundsTop Coordinate OPTIONAL, + boundsRight Coordinate OPTIONAL, + boundsBottom Coordinate OPTIONAL, + ... +} + +ShareDataHeader ::= SEQUENCE { + shareID ShareID, + generalCompressionSpecifier GeneralCompressionSpecifier OPTIONAL, + ... +} + +-- Order Types +DestinationBltOrder ::= SEQUENCE { + header PrimaryOrderHeader, + destLeft Coordinate OPTIONAL, + destTop Coordinate OPTIONAL, + destWidth Coordinate OPTIONAL, + destHeight Coordinate OPTIONAL, + rop3 ROP3 OPTIONAL, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +PatternBltOrder ::= SEQUENCE { + header PrimaryOrderHeader, + destLeft Coordinate OPTIONAL, + destTop Coordinate OPTIONAL, + destWidth Coordinate OPTIONAL, + destHeight Coordinate OPTIONAL, + rop3 ROP3 OPTIONAL, + backgroundColor Color OPTIONAL, + foregroundColor Color OPTIONAL, + brush Brush OPTIONAL, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +ScreenBltOrder ::= SEQUENCE { + header PrimaryOrderHeader, + destLeft Coordinate OPTIONAL, + destTop Coordinate OPTIONAL, + destWidth Coordinate OPTIONAL, + destHeight Coordinate OPTIONAL, + rop3 ROP3 OPTIONAL, + sourceX Coordinate OPTIONAL, + sourceY Coordinate OPTIONAL, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +CacheBitmapOrder ::= SEQUENCE { + cacheId INTEGER(0..2), + bitmapWidth Integer8, + bitmapHeight Integer8, + bitmapBitsPerPel INTEGER(1 | 4 | 8), + cacheIndex Integer16, + bitmapData BitmapData, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +``` + +``` + +} + +CacheColorTableOrder ::= SEQUENCE { + cacheIndex Integer8, + colorTable ColorPalette, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +MemoryBltOrder ::= SEQUENCE { + header PrimaryOrderHeader, + colorTableCacheIndex Integer8 OPTIONAL, + bitmapCacheID Integer8 OPTIONAL, + destLeft Coordinate OPTIONAL, + destTop Coordinate OPTIONAL, + destWidth Coordinate OPTIONAL, + destHeight Coordinate OPTIONAL, + rop3 ROP3 OPTIONAL, + sourceX Coordinate OPTIONAL, + sourceY Coordinate OPTIONAL, + bitmapCacheIndex Integer16 OPTIONAL, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +MemoryThreeWayBltOrder ::= SEQUENCE { + header PrimaryOrderHeader, + colorTableCacheIndex Integer8 OPTIONAL, + bitmapCacheID Integer8 OPTIONAL, + destLeft Coordinate OPTIONAL, + destTop Coordinate OPTIONAL, + destWidth Coordinate OPTIONAL, + destHeight Coordinate OPTIONAL, + rop3 ROP3 OPTIONAL, + sourceX Coordinate OPTIONAL, + sourceY Coordinate OPTIONAL, + backgroundColor Color OPTIONAL, + foregroundColor Color OPTIONAL, + brush Brush OPTIONAL, + bitmapCacheIndex Integer16 OPTIONAL, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +TextOrder ::= SEQUENCE { + header PrimaryOrderHeader, + backMixMode BackgroundMixMode OPTIONAL, + startX Coordinate OPTIONAL, + startY Coordinate OPTIONAL, + backgroundColor Color OPTIONAL, + foregroundColor Color OPTIONAL, + extraSpacing Integer16 OPTIONAL, + totalBreakSpacing Integer16 OPTIONAL, + breakCount Integer16 OPTIONAL, + fontHeight Integer16 OPTIONAL, + fontWidth Integer16 OPTIONAL, + fontWeight Integer16 OPTIONAL, + textFlags TextAttributeFlags OPTIONAL, + fontID Integer16 OPTIONAL, + codePointList ASString(SIZE (1..255)) OPTIONAL, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + +``` + +``` + + -- Subject to capability negotiation. + ... +} + +ExtendedTextOrder ::= SEQUENCE { + header PrimaryOrderHeader, + backMixMode BackgroundMixMode OPTIONAL, + startX Coordinate OPTIONAL, + startY Coordinate OPTIONAL, + backgroundColor Color OPTIONAL, + foregroundColor Color OPTIONAL, + extraSpacing Integer16 OPTIONAL, + totalBreakSpacing Integer16 OPTIONAL, + breakCount Integer16 OPTIONAL, + fontHeight Integer16 OPTIONAL, + fontWidth Integer16 OPTIONAL, + fontWeight Integer16 OPTIONAL, + textFlags1 TextAttributeFlags OPTIONAL, + fontID Integer16 OPTIONAL, + textFlags2 ExtraTextFlags OPTIONAL, + clipLeft Coordinate OPTIONAL, + clipTop Coordinate OPTIONAL, + clipRight Coordinate OPTIONAL, + clipBottom Coordinate OPTIONAL, + codePointList ASString(SIZE (1..255)) OPTIONAL, + deltaXList SEQUENCE (SIZE (1..127)) OF Coordinate OPTIONAL, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +FrameOrder ::= SEQUENCE { + header PrimaryOrderHeader, + destLeft Coordinate OPTIONAL, + destTop Coordinate OPTIONAL, + destWidth Coordinate OPTIONAL, + destHeight Coordinate OPTIONAL, + rop3 ROP3 OPTIONAL, + backgroundColor Color OPTIONAL, + foregroundColor Color OPTIONAL, + brush Brush OPTIONAL, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +RectangleOrder ::= SEQUENCE { + header PrimaryOrderHeader, + backMixMode BackgroundMixMode OPTIONAL, + destLeft Coordinate OPTIONAL, + destTop Coordinate OPTIONAL, + destRight Coordinate OPTIONAL, + destBottom Coordinate OPTIONAL, + backgroundColor Color OPTIONAL, + foregroundColor Color OPTIONAL, + brush Brush OPTIONAL, + rop2 ROP2 OPTIONAL, + pen Pen OPTIONAL, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +OpaqueRectangleOrder ::= SEQUENCE { + +``` + +``` + +header PrimaryOrderHeader, +destLeft Coordinate OPTIONAL, +destTop Coordinate OPTIONAL, +destWidth Coordinate OPTIONAL, +destHeight Coordinate OPTIONAL, +color Color OPTIONAL, +nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, +-- Subject to capability negotiation. +... +} + +LineOrder ::= SEQUENCE { + header PrimaryOrderHeader, + backMixMode BackgroundMixMode OPTIONAL, + startX Coordinate OPTIONAL, + startY Coordinate OPTIONAL, + endX Coordinate OPTIONAL, + endY Coordinate OPTIONAL, + backgroundColor Color OPTIONAL, + rop2 ROP2 OPTIONAL, + pen Pen OPTIONAL, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, +-- Subject to capability negotiation. +... +} + +DesktopSaveOrder ::= SEQUENCE { + header PrimaryOrderHeader, + saveOffset Integer32 OPTIONAL, + destLeft Coordinate OPTIONAL, + destTop Coordinate OPTIONAL, + destWidth Coordinate OPTIONAL, + destHeight Coordinate OPTIONAL, + action DesktopSaveAction OPTIONAL, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, +-- Subject to capability negotiation. +... +} + +DesktopOriginOrder ::= SEQUENCE { + header PrimaryOrderHeader, + desktopLeft Coordinate OPTIONAL, + desktopTop Coordinate OPTIONAL, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, +-- Subject to capability negotiation. +... +} + +ColorSpaceOrder ::= SEQUENCE { + colorSpace ColorSpaceSpecifier, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, +-- Subject to capability negotiation. +... +} + +PrimaryOrder ::= CHOICE { + destinationBlt [0] DestinationBltOrder, + patternBlt [1] PatternBltOrder, + screenBlt [2] ScreenBltOrder, + memoryBlt [13] MemoryBltOrder, + memoryThreeWayBlt [14] MemoryThreeWayBltOrder, + text [5] TextOrder, + extendedText [6] ExtendedTextOrder, + frame [9] FrameOrder, + +``` + +``` + +rectangle [7] RectangleOrder, +line [8] LineOrder, +opaqueRectangle [10] OpaqueRectangleOrder, +desktopSave [11] DesktopSaveOrder, +desktopOrigin [32] DesktopOriginOrder, +nonStandardPrimaryOrder NonStandardParameter, +-- Subject to capability negotiation. +... +} + +SecondaryOrder ::= CHOICE { + cacheBitmap [0] CacheBitmapOrder, + cacheColorTable [1] CacheColorTableOrder, + colorSpaceOrder [2] ColorSpaceOrder, + nonStandardSecondaryOrder [3] NonStandardParameter, +-- Subject to capability negotiation. +... +} + +UpdateOrder ::= CHOICE { + primaryOrder PrimaryOrder, + secondaryOrder SecondaryOrder, + nonStandardOrder NonStandardParameter, +-- Subject to capability negotiation. +... +} + +--//////////////////////////////////////////////////////////////////// +-- +-- Begin AS PDU Definitions +-- +--//////////////////////////////////////////////////////////////////// + +ApplicationPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, + action + CHOICE {notifyHostedApplications [1] NotifyHostedApplications, + unhostApplication [2] UnhostApplication, + nonStandardAction NonStandardParameter, + -- Subject to capability negotiation. + ...}, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, +-- Subject to capability negotiation. +... +} + +ControlPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, + action + CHOICE {requestControl [1] RequestControl, + grantControl [2] GrantControl, + detach [3] Detach, + cooperate [4] Cooperate, + nonStandardAction NonStandardParameter, + -- Subject to capability negotiation. + ...}, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, +-- Subject to capability negotiation. +... +} + +FlowResponsePDU ::= SEQUENCE { + flowIdentifier INTEGER(0..127), + flowNumber Integer8, + +``` + +``` + + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +FlowStopPDU ::= SEQUENCE { + flowIdentifier INTEGER(0..127), + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +FlowTestPDU ::= SEQUENCE { + flowIdentifier INTEGER(0..127), + flowNumber Integer8, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +FontPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, + fontList SEQUENCE OF FontAttribute, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +InputPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, + eventList SEQUENCE OF InputEvent, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +MediatedControlPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, + action + CHOICE {takeControlRequest [1] TakeControlRequest, + passControlRequest [2] PassControlRequest, + detachRequest [3] DetachRequest, + confirmTakeResponse [5] ConfirmTakeResponse, + denyTakeResponse [6] DenyTakeResponse, + confirmDetachResponse [7] ConfirmDetachResponse, + denyDetachResponse [8] DenyDetachResponse, + denyPassResponse [9] DenyPassResponse, + remoteDetachRequest [10] RemoteDetachRequest, + denyRemoteDetachResponse [11] DenyRemoteDetachResponse, + nonStandardAction NonStandardParameter, + -- Subject to capability negotiation. + ...}, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +PointerPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, + pointerData + CHOICE {systemPointerType [1] SystemPointerType, + monoPointerAttribute [2] MonoPointerAttribute, + colorPointerAttribute [6] ColorPointerAttribute, + cachedPointerIndex [7] Integer16, + +``` + +``` + + pointerPosition [3] Point16, + nonStandardPointer NonStandardParameter, + -- Subject to capability negotiation. + ...}, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +RemoteSharePDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, + action + CHOICE {requestRemoteShare [1] RequestRemoteShare, + confirmRemoteShare [2] ConfirmRemoteShare, + denyRemoteShare [3] DenyRemoteShare, + nonStandardAction NonStandardParameter, + -- Subject to capability negotiation. + ...}, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +SynchronizePDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, + targetUser UserID, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +UpdateBitmapPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, + destLeft Coordinate16, + destTop Coordinate16, + destRight Coordinate16, + destBottom Coordinate16, + width Integer16, + height Integer16, + bitsPerPixel INTEGER(1 | 4 | 8), + compressedFlag BOOLEAN, + bitmapData BitmapData, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +UpdateOrdersPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, + orderList SEQUENCE OF UpdateOrder, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +UpdatePalettePDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, + palette ColorPalette, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, + -- Subject to capability negotiation. + ... +} + +UpdateSynchronizePDU ::= SEQUENCE { + +``` + +``` + +shareDataHeader ShareDataHeader, +nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, +-- Subject to capability negotiation. +... +} + +WindowActivationPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, + action + CHOICE {localWindowActive [1] LocalWindowActiveIndication, + hostedWindowActive [2] HostedWindowActiveIndication, + hostedWindowInvisible [3] HostedWindowInvisibleIndication, + pointerDeviceCapture [4] PointerDeviceCaptureIndication, + activateWindow [12769] ActivateWindowRequest, + closeWindow [12770] CloseWindowRequest, + restoreWindow [12771] RestoreWindowRequest, + windowManagerMenu [12772] WindowManagerMenuRequest, + activationHelpKey [12785] ActivationHelpKeyRequest, + activationHelpIndexKey [12786] ActivationHelpIndexKeyRequest, + activationHelpExtendedKey [12787] ActivationHelpExtendedKeyRequest, + nonStandardAction NonStandardParameter, + -- Subject to capability negotiation. + ...}, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, +-- Subject to capability negotiation. + ... +} + +WindowListPDU ::= SEQUENCE { + shareDataHeader ShareDataHeader, + listTime Integer16, + listID Integer16, + windowAttributeList SEQUENCE OF WindowAttribute, + windowTitleList SEQUENCE OF WindowTitle, + nonStandardParameters SEQUENCE OF NonStandardParameter OPTIONAL, +-- Subject to capability negotiation. + ... +} + +ASNonStandardPDU ::= SEQUENCE { + nonStandardParameter NonStandardParameter, +-- Subject to capability negotiation. + ... +} + +SharePDU ::= CHOICE { + applicationPDU [25] ApplicationPDU, + controlPDU [20] ControlPDU, + flowResponsePDU [66] FlowResponsePDU, + flowStopPDU [67] FlowStopPDU, + flowTestPDU [65] FlowTestPDU, + fontPDU [11] FontPDU, + inputPDU [28] InputPDU, + mediatedControlPDU [29] MediatedControlPDU, + pointerPDU [27] PointerPDU, + remoteSharePDU [30] RemoteSharePDU, + synchronizePDU [31] SynchronizePDU, + updateBitmapPDU [1] UpdateBitmapPDU, + updateOrdersPDU [0] UpdateOrdersPDU, + updateSynchronizePDU [3] UpdateSynchronizePDU, + updatePalettePDU [2] UpdatePalettePDU, + windowActivationPDU [23] WindowActivationPDU, + windowListPDU [24] WindowListPDU, + asNonStandardPDU ASNonStandardPDU, + +``` + +``` + +} ... +--//////////////////////////////////// +-- +-- End AS Definitions +-- +--//////////////////////////////////// +END + +``` + +## 9.3 Legacy mode encoding rules + +The AS encoding for ASPDU data elements defined in clause 9.1 is as follows. + +The bits of the bit combinations of an octet are identified by $b_7$ , $b_6$ , $b_5$ , $b_4$ , $b_3$ , $b_2$ , $b_1$ and $b_0$ , where $b_7$ is the highest-order, or most significant, bit and $b_0$ is the lowest-order, or least significant, bit. + +- An octet within a data element is encoded as a sequence of bits, where $b_7$ of the octet is encoded into the highest-order, or most significant, bit of the corresponding encoded octet, $b_6$ is encoded into the next highest-order bit, and so on, filling towards the least significant bit. +- OCTET STRING is encoded as a sequence of octets in the order in which they appear in the data element. +- INTEGER (0..15) is encoded to the highest-order, or most significant, available four bits within an octet. +- INTEGER (0..255) and INTEGER (−128..127) are encoded to an octet containing the two's complement binary value of the data element. +- INTEGER (0..4095) is encoded to the highest-order, or most significant, available twelve bits within an octet. +- INTEGER (0..65535) and INTEGER (−32768..32767) are encoded to two octets containing the two's complement binary value of the data element, where the highest-order, or most significant, octet is placed in the second octet. +- INTEGER (0..4294967295) is encoded to four octets containing the two's complement binary value of the data element; octets are arranged in increasing significance, where the highest-order, or most significant, octet is placed in the fourth octet. +- BIT STRING (0..7) is encoded as a single octet. +- BIT STRING (0..15) is encoded as INTEGER (0..65535). +- BIT STRING (0..31) is encoded as INTEGER (0..4294967295). +- All bits are packed to bit boundaries. Pad elements are explicitly defined. +- Where a data element is a member of a CHOICE type, the specific data element encoded for the choice depends on other data elements as described in the protocol specification (see clause 8). No additional bits are encoded for such data elements. +- Where a data element is OPTIONAL, whether the data element is encoded or not depends on other data elements as described in the protocol specification (see clause 8). No additional bits are encoded for such data elements. +- Where the usage of a data element is not specified in the protocol specification (clause 8), the data element is encoded as above, but the bit values are undefined. + +## 9.4 Base mode non-collapsing capabilities encoding rules + +In the base mode of the AS protocol, an ASCE may advertise a particular capability via either the collapsing or non-collapsing capabilities lists in the roster (see clause 8.2.2). Where an ASCE + +advertises a particular capability via the non-collapsing capabilities list in the roster, then it shall encode the capability value using the encoding rules defined in this clause. + +In the base mode of the AS protocol, capabilities may be one of the classes defined in Table 8-1. + +The defined capability classes are encoded using the BASIC ALIGNED variant of the packed encoding rules of [ITU-T X.691] based on the following ASN.1 definitions. + +**LogicalNonCollapsingCapability ::= BOOLEAN**                      *-- Class L: logical value.* +**IntegerNonCollapsingCapability ::= INTEGER (MIN..MAX)**        *-- Class N: signed or unsigned integer value.* + +After encoding, the encoded value for a particular capability is used as the non-collapsing capability value for subsequent encoding by GCC. + +# **Annex A** + +## **Static channel ID assignments** + +(This annex forms an integral part of this Recommendation) + +Table A.1 lists the numerical assignment of static channel IDs for the static channels allocated for use by this Recommendation. The numerical assignment of static channel IDs is listed in [ITU-T T.120]. + +**Table A.1 – Static channel ID assignments** + +| Symbolic name | Channel ID | +|----------------------|-------------------| +| AS-CHANNEL-0 | 11 | + +# Annex B + +## Legacy application protocol key + +(This annex forms an integral part of this Recommendation) + +Table B.1 defines the contents of the application protocol key used to identify the legacy mode of the application protocol defined by this Recommendation. + +**Table B.1 – Legacy application protocol key** + +| Application protocol key | Description | +|-----------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| h221NonStandard: 0xB5, 0x00, 0x53, 0x4C, 0x02 | This defines the contents of the application protocol key used to identify the legacy mode of the application protocol defined by this Recommendation. Note that the H.221 non-standard identifier option is used to define this key. The numerical values shown represent the contents of the H221NonStandardIdentifier as defined in [ITU-T T.124]. | + +# **Annex C** + +## **Object identifier assignments** + +(This annex forms an integral part of this Recommendation) + +Table C.1 lists the assignment of object identifiers defined for use by this Recommendation. + +**Table C.1** + +| Object identifier value | Description | +|--------------------------------------------|--------------------------------------------------------------------------------| +| {itu-t recommendation t 128 version (0) 1} | This object identifier is used to indicate the version of this Recommendation. | + +# Appendix I + +## Informative values + +(This appendix does not form an integral part of this Recommendation) + +This appendix provides suggestions for various values described within the main body of this Recommendation, based on experience with application sharing on a number of terminal types. These values are not mandatory and the actual values used by a specific ASCE are left to the discretion of the implementer. + +## I.1 Flow control + +The following values and expressions are suggested for use in the flow control algorithm described in clause 8.5. See Tables I.1, I.2 and I.3. + +**Table I.1 – Flow control constants** + +| Item | MCS high priority | MCS medium priority | MCS low priority | +|-------------------|-------------------|---------------------|------------------| +| target_round_trip | 2 000 | Not flow controlled | 7 000 | +| target_in_flight | 800 | Not flow controlled | 99 000 | +| max_queued_rcv | 5 | Not flow controlled | 5 | + +**Table I.2 – Flow control variables** + +| Item | Initial value | Minimum | Maximum | +|-------------------------------|---------------|---------|---------| +| flow_period
(milliseconds) | 1 000 | 100 | 1 000 | +| max_in_flight | 8 000 | 500 | 256 000 | + +**Table I.3 – Flow control operations** + +| Operation | Expression | +|------------------------|----------------------------------------------------------------------------------------------------| +| Decrease max_in_flight | $\text{max\_in\_flight} = \text{max\_in\_flight}/2$ (but not below minimum value in Table I.2) | +| Increase max_in_flight | $\text{max\_in\_flight} = \text{max\_in\_flight}*2$ (but not above the maximum value in Table I.2) | +| Decrease flow_period | $\text{flow\_period} = \text{flow\_period}/2$ (but not below minimum value in Table I.2) | +| Increase flow_period | $\text{flow\_period} = \text{flow\_period}*2$ (but not above maximum value in Table I.2) | + +## I.2 Bitmap caching + +The following values are suggested for use in the bitmap cache capability set described in clause 8.2.7. + +| Item | Suggested value | +|-----------------------|-----------------| +| cache1Entries | 600 | +| cache1MaximumCellSize | 496 | +| cache2Entries | 300 | +| cache2MaximumCellSize | 2 032 | +| cache3Entries | 150 | +| cache3MaximumCellSize | 4 080 | + +## I.3 ColorTable caching + +The following values are suggested for use in the ColorTable cache capability set described in clause 8.2.8. + +| Item | Suggested value | +|---------------------|-----------------| +| colorTableCacheSize | 6 | + +## I.4 Pointer caching + +The following values are suggested for use in the pointer capability set described in clause 8.2.11. + +| Item | Suggested value | +|------------------|-----------------| +| colorPointerFlag | TRUE | +| pointerCacheSize | 25 | + +## I.5 Desktop save cache + +The following values are suggested for use for the desktop save cache values in the order capability set described in clause 8.2.5 and for the desktop cache algorithm described in clause 8.16.17. + +| Item | Suggested value | +|-------------------------|-----------------| +| desktopSaveSize | 160,000 | +| desktopSaveXGranularity | 1 | +| desktopSaveYGranularity | 20 | + +## I.6 General compression + +The following are suggested values for use in legacy mode for negotiation and usage of general compression, as described in clause 8.3.2. + +| Compression scheme | generalCompressionTypes
(see Table 8-3) | generalCompressionLevel
(see Table 8-3) | generalCompressedType
(see Table 8-23) | +|--------------------|--------------------------------------------|--------------------------------------------|-------------------------------------------| +| PKWARE PKZIP | Bit flag 0 set | 0 and 1 | 1 | + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|---------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.137-200002-I_PDF-E/raw.md b/marked/T/T-REC-T.137-200002-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..5d0ed0103cb6868ced431ca87c05c7aaf54f22e5 --- /dev/null +++ b/marked/T/T-REC-T.137-200002-I_PDF-E/raw.md @@ -0,0 +1,6066 @@ + + +![ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe. + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**T.137** + +(02/2000) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES + +--- + +# **Virtual meeting room management for multimedia conferencing audiovisual control** + +ITU-T Recommendation T.137 + +(Formerly CCITT Recommendation) + +--- + + + +# **VIRTUAL MEETING ROOM MANAGEMENT FOR MULTIMEDIA CONFERENCING AUDIOVISUAL CONTROL** + +## **Summary** + +This Recommendation defines the functionality required to deliver a combined voice- and data-conferencing (audiographics) service; it is architected to deliver such services using generic and extensible mechanisms that are independent of the underlying transports used for delivering the real-time media streams. + +In future revisions this scope is expected to broaden to cover all media services used within a conference. + +This protocol extends the Generic Conference Control Recommendation (T.124), adding the capability to define and manage virtual meetings spaces within the GCC conference. It provides a means to seamlessly integrate all of the media components being used within a meeting. + +These virtual meeting spaces can be regarded as representing meeting rooms where audio, video and data communication can take place. The functionality provides support for a number of virtual meeting scenarios including round-table meetings, informal meeting spaces and conferences with audiences. The protocol provides inherent support for multi-room scenarios. + +The protocol will find application in support of enhanced audio conferencing and audiographics conferencing services. The aim is to provide an holistic approach to the management of the meeting room involving multiple media, while providing the flexibility to adapt individual meeting rooms in response to user requirements. The object of standardizing this functionality is to provide a basis for interoperability between client applications and conferencing services. + +## **Source** + +ITU-T Recommendation T.137 was prepared by ITU-T Study Group 16 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on 17 February 2000. + +## FOREWORD + +ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +## INTELLECTUAL PROPERTY RIGHTS + +The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. + +© ITU 2001 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +## CONTENTS + +| | Page | +|-------------------------------------------------------------------|-------------| +| 1 Scope..... | 1 | +| 2 References..... | 2 | +| 3 Definitions ..... | 3 | +| 4 Abbreviations..... | 4 | +| 5 Conventions ..... | 5 | +| 6 Overview..... | 5 | +| 7 Meeting room management – Components ..... | 6 | +| 7.1 Virtual meeting rooms ..... | 6 | +| 7.2 The lobby ..... | 7 | +| 7.3 The conference framework ..... | 7 | +| 7.4 MRM rosters ..... | 8 | +| 7.4.1 The MRM conference roster..... | 8 | +| 7.4.2 The MRM room roster..... | 8 | +| 7.4.3 Roster operation..... | 8 | +| 7.5 Meeting room types ..... | 8 | +| 7.6 Meeting room modes ..... | 9 | +| 7.7 Room Hierarchies and relationships ..... | 9 | +| 7.7.1 Room access regimes..... | 9 | +| 7.7.2 Room entry regimes..... | 9 | +| 7.7.3 Room state ..... | 10 | +| 7.8 Classes of participation in a conference..... | 10 | +| 7.8.1 MRM observers ..... | 11 | +| 7.8.2 MRM participants..... | 11 | +| 7.8.3 MRM administrators..... | 12 | +| 7.8.4 MRM groups..... | 12 | +| 7.9 MRM conference services ..... | 13 | +| 7.10 Starting an MRM conference..... | 13 | +| 7.10.1 Private side communication..... | 14 | +| 7.10.2 Relationship between meeting rooms and data sessions ..... | 14 | +| 7.10.3 Role and relationship to the GCC conductor..... | 15 | +| 7.10.4 MRM management nodes..... | 15 | +| 7.10.5 Proxying MRM functionality..... | 15 | +| 8 T.137 infrastructure management functionality..... | 15 | +| 8.1 Use Of MCS channels..... | 15 | +| 8.2 Static channels ..... | 15 | + +| | Page | +|-------------------------------------------------------------------|-------------| +| 8.3 Dynamic channels ..... | 16 | +| 9 MRM infrastructure management service definition ..... | 16 | +| 9.1 Summary of MRM abstract services ..... | 16 | +| 9.2 Establishing the MRM Top provider ..... | 19 | +| 9.3 MRM conference framework ..... | 19 | +| 9.3.1 Description of abstract services ..... | 24 | +| 9.4 The MRM rosters ..... | 26 | +| 9.4.1 Description of abstract services ..... | 27 | +| 9.5 Meeting rooms ..... | 32 | +| 9.5.1 Description of abstract services ..... | 33 | +| 9.6 MRM groups ..... | 39 | +| 9.6.1 Specifying groups in the framework ..... | 39 | +| 9.6.2 Specifying groups within an active room ..... | 39 | +| 9.6.3 Description of abstract services ..... | 39 | +| 9.7 T.120 sessions ..... | 43 | +| 9.7.1 Description of abstract services ..... | 43 | +| 9.8 MRM room roles ..... | 44 | +| 9.8.1 Room role permissions – Specification ..... | 46 | +| 9.8.2 Room Roles – Description of abstract services ..... | 48 | +| 9.8.3 The chair role ..... | 57 | +| 9.8.4 Accessing pre-defined roles ..... | 58 | +| 9.8.5 Asking a role holder for permission to Act ..... | 58 | +| 9.9 Permission to take action (Incorporating floor control) ..... | 58 | +| 9.9.1 Description of abstract services ..... | 58 | +| 9.10 Conference media controls and indications ..... | 64 | +| 9.10.1 Description of abstract services ..... | 64 | +| 9.11 MRM media services ..... | 71 | +| 9.11.1 Service events ..... | 71 | +| 9.11.2 Audio Bridging Service ..... | 72 | +| 9.12 Audio Mixer management ..... | 72 | +| 9.12.1 Description of abstract services ..... | 72 | +| 10 MRM protocol definition ..... | 79 | +| 10.1 MRM node types ..... | 79 | +| 10.2 Launching MRM ..... | 79 | +| 10.3 Determining the MRM top provider ..... | 79 | +| 10.4 MRM initialization and start-up ..... | 79 | +| 10.5 General Operation ..... | 82 | + +| | | | +|-------|--------------------------------------------------------------|-----| +| 10.6 | Framework PDUs..... | 83 | +| 10.7 | Roster PDUs ..... | 85 | +| | 10.7.1 Roster Reporting..... | 85 | +| | 10.7.2 Updating participants roster information..... | 87 | +| 10.8 | Room PDUs ..... | 88 | +| | 10.8.1 Creating an MRM Room ..... | 88 | +| | 10.8.2 Entering An MRM Room ..... | 90 | +| | 10.8.3 Invitation to an MRM Room ..... | 92 | +| | 10.8.4 Creating a group ..... | 92 | +| 10.9 | T.120 Session Association..... | 95 | +| 10.10 | Room role PDUs..... | 95 | +| | 10.10.1 Assigning an MRM role ..... | 95 | +| | 10.10.2 Relinquishing an MRM role ..... | 97 | +| | 10.10.3 Asking for an MRM role ..... | 98 | +| | 10.10.4 Passing An MRM Role to another Room Participant..... | 98 | +| | 10.10.5 Changing role permissions ..... | 100 | +| 10.11 | Permission PDUs ..... | 100 | +| | 10.11.1 Asking the chair for permission to take action ..... | 100 | +| | 10.11.2 Relinquishing Permission ..... | 101 | +| | 10.11.3 Chair grants permission ..... | 102 | +| 10.12 | Source Identification PDUs ..... | 102 | +| 10.13 | Indication PDUs..... | 103 | +| | 10.13.1 Notification of privacy..... | 103 | +| 10.14 | Service Command PDUs ..... | 104 | +| 10.15 | Audio Management PDUs ..... | 105 | +| | 10.15.1 Service initialization ..... | 105 | +| | 10.15.2 Audio Mixer Setup ..... | 105 | +| | 10.15.3 Audio Mixer status reporting..... | 106 | +| | 10.15.4 Inviting Audio-Only participation ..... | 107 | +| | 10.15.5 Ejecting an-Audio-Only participant..... | 108 | +| 11 | ASN.1 Definitions ..... | 109 | +| 12 | Requirements for running MRM ..... | 129 | +| 12.1 | Summary of GCC services required by MRM..... | 129 | +| 12.2 | Summary of use of the Multipoint Communication Service ..... | 129 | +| | 12.2.1 MCS services..... | 129 | +| | 12.2.2 MCS channels used by MRM..... | 130 | +| | 12.2.3 MCS Tokens used by MRM..... | 131 | +| | 12.2.4 Encoding of PDUs in MCS primitives ..... | 131 | + + + +## **Recommendation T.137** + +# **VIRTUAL MEETING ROOM MANAGEMENT FOR MULTIMEDIA CONFERENCING AUDIOVISUAL CONTROL** + +# **1 Scope** + +This Recommendation provides extensions to the Generic Conference Control functionality to support the specification and management of virtual meeting spaces (meeting rooms) within a conference. It provides a cohesive and uniform approach to the management of all media used within the meeting room irrespective of the underlying transport and media encodings used.1 This work is expected to find application in the provision of commercial conference services. + +This Recommendation defines procedures for arbitrating use of real-time media services such as telephony and video streaming2, for advertising those services to participating nodes, and for managing and controlling those services once activated. This Recommendation specifies mechanisms for multimedia capability reporting at the start of and during communications, and defines procedures for arbitrating access to, and configuring the infrastructure in support of, the services. + +This Recommendation supports conferences in which data communication is established first as well as conferences in which audio communications are established first. The provisions of this Recommendation are independent of the underlying network(s) and the content of real-time streams that traverse those networks. Furthermore, this Recommendation provides the possibility for different types of multimedia system to co-exist within the same conference and for those systems to be controlled in a uniform manner. + +This Recommendation defines a Conference Server that takes responsibility for the running of the MRM Conference and a service access channel for communication between the clients and server. The MRM protocol places minimal implementation burden on client terminals with most of the complexity being concentrated at the Server. This provides centralized management of the real-time infrastructure. A single server node is assigned to be the Conference Manager and the MRM Top Provider. However, communication from clients to the MRM Top Provider is always directed to the Conference Management channel, allowing other Network Elements to also join this channel and to cooperate in delivering the conference. These other Network Elements may shadow the MRM Top Provider, allowing the possibility of one of them taking on the Top Provider role in the event of a failure condition which disables the current Conference.3 This provision also allows the possibility of a distributed management mode in future versions of this protocol, enabling it to more readily scale to support large conference environments. + +This Recommendation requires the services of MCS and GCC. + +--- + +1 The use of this Recommendation with H-series Recommendations is outside the scope of this work and is part of a separate harmonization activity. + +2 Video-streaming excludes solutions based upon Recommendation H.323, which are for further study and are outside the current scope. + +3 This is currently outside the scope of this Recommendation. + +![Figure 1/T.137 – Audiovisual control architecture diagram showing the flow from User Applications through various control and protocol layers to the Network.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +The diagram illustrates the audiovisual control architecture. At the top is a box for 'User Applications'. Below it, on the left, are 'Real-time Audio Device' and 'Real-time Video Device' boxes, each connected to 'User Applications' by a double-headed arrow. These devices output 'Audio Stream(s)' and 'Video Stream(s)' respectively, shown as thick vertical lines. In the center is a 'Node Controller' box, connected to 'User Applications' by a double-headed arrow. Below the 'Node Controller' are two boxes: 'ITU-T Standard Application Protocol Entities' and 'Non-Standard Application Protocol Entities', both connected to the 'Node Controller' by double-headed arrows. Below these are 'Meeting Room Management T.137' and 'Generic Conference Control T.124 (GCC)', both connected to the 'Node Controller' and to each other by double-headed arrows. Below these is a 'Multipoint Communication Service T.122/T.125 (MCS)' box, connected to the 'Node Controller' and to the 'Meeting Room Management' and 'Generic Conference Control' boxes by double-headed arrows. Below the 'MCS' box is a 'Network Transport Protocols (T.123)' box, connected to the 'MCS' box by a double-headed arrow. At the bottom is a 'Network' box, connected to the 'Network Transport Protocols' box by a double-headed arrow labeled 'Data'. The 'Meeting Room Management T.137' box is shaded grey. + +Figure 1/T.137 – Audiovisual control architecture diagram showing the flow from User Applications through various control and protocol layers to the Network. + +T1607350-99 + +**Figure 1/T.137 – Audiovisual control architecture** + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. + +- ITU-T Recommendation T.120 (1996), *Data protocols for multimedia conferencing*. +- ITU-T Recommendation T.121 (1996), *Generic application template*. +- ITU-T Recommendation T.122 (1998), *Multipoint communication service – Service definition*. +- ITU-T Recommendation T.123 (1996), *Network-specific data protocol stacks for multimedia conferencing*. +- ITU-T Recommendation T.124 (1998), *Generic Conference Control*. + +- ITU-T Recommendation T.125 (1998), *Multipoint communication service protocol specification*. +- ITU-T Recommendation X.680 (1997) | ISO/IEC 8824-1:1998, *Information technology – Abstract Syntax Notation One (ASN.1): Specification of basic notation*. +- ITU-T Recommendation X.691 (1997) | ISO/IEC 8825-2:1998, *Information technology – ASN.1 encoding rules – Specification of Packed Encoding Rules (PER)*. + +## 3 Definitions + +This Recommendation defines the following terms: + +- 3.1 application protocol:** Any standard or non-standard protocol specification that makes use of T.120 services. +- 3.2 application protocol entity:** The instantiation of an application protocol in a terminal or MCU. +- 3.3 application protocol session:** A group of peer application protocol entities communicating with each other. +- 3.4 conference framework:** A predefined specification for a conference. The framework is created out of band but is specified in this Recommendation because it is passed into an active conference and its parameters are available through the conference roster. +- 3.5 meeting room model:** A model of a room to support either a formal or an informal meeting between peers. All role holders are supported. +- 3.6 conference room model:** A model of a presentation room which, in addition to the meeting room model, supports Observers. +- 3.7 coffee room model:** An informal meeting space which supports ad hoc communication and dynamic creation and destruction of meeting spaces, these meeting spaces are also represented by MRM rooms. +- 3.8 convenor:** The entity responsible for creation of the MRM conference. +- 3.9 MRM conference:** A conference in which the MRM protocol is used to manage and control all the media used within the conference. +- 3.10 MRM top provider:** Entity within a node responsible for managing an MRM conference. +- 3.11 MRM conference manager:** The name given to the node controller associated with the MRM Top Provider. The conference manager has overall responsibility for running the conference. +- 3.12 MRM room:** A virtual meeting room created within an MRM conference. Effectively, a subset of MRM conference participants formed into a separate and autonomous group of nodes for the purposes of communicating both data and real-time streams within that group. +- 3.13 MRM group:** An association of room participants, allowing them to effectively be treated as a single entity for management, control or information distribution; unlike an MRM room, an MRM group is not an autonomous partitioning of a conference or a room. +- 3.14 MRM terminal:** A terminal node that supports and makes use of the MRM protocol. +- 3.15 MRM participant:** A node which has joined the conference as a GCC conventional node running the MRM protocol and participating in the MRM conference. +- 3.16 MRM observer:** A node which may be either a GCC conventional or anonymous node, running the MRM protocol, but taking an observer role in the conference. + + + +## 5 Conventions + +The primitive parameters of the abstract services defined in this Recommendation use the following key: + +M Parameter is mandatory + +C Parameter is conditional + +O Parameter is optional + +Blank Parameter is absent + +(=) Value of the parameter is identical to the value of the corresponding parameter of the preceding primitive, where preceding is defined relative to the order: request, indication, response, confirm. + +(=RQ) Value of the parameter is identical to the value of the corresponding parameter in a preceding primitive, where RQ = request, IN = indication, RS = response, and CF = confirm. + +Primitives are categorized in up to four types: Request, Indication, Response, and Confirm. Some primitives support all of these types, while others do not. These four types are defined as follows: + +Request primitive: Those that are sourced from a node controller, application protocol entity or user application to initiate a certain action. + +Indication primitive: Those that are sourced from an MRM provider either as a result of a Request primitive, or as a result of an MRM-initiated action. + +Response primitive: Those that are sourced from a node controller in response to an Indication primitive which is defined to require a response. + +Confirm primitive: Those that are sourced from an MRM provider as a result of a Response primitive. + +## 6 Overview + +This Meeting Room Management (MRM) Recommendation defines an application protocol that is designed to be used in conjunction with the Generic Conference Control (T.124). MRM provides enhanced conference management and control capabilities that will find application in support of a variety of conferencing scenarios, including audiographics services. Its main application will be in supporting the provision of these conferencing services, where it is designed to provide better simulation of a diverse range of real-world face-to-face meeting scenarios. The Recommendation can be regarded as a toolkit of functionality that can be used to build and configure conferences to match user requirements. + +MRM provides the mechanisms to support a number of meeting room types, each with its own set of capabilities. Each room type has an appropriate set of rules specified, relating to participation and facilities available. MRM also standardizes a number of participant roles, assigning privileges and constraints as appropriate for the intended role. + +Rooms and roles may be combined flexibly with management regimes to model the meeting requirement and controls and indications are available for all the media to be used within each meeting space. Unlike GCC, the functionality provided is focused around rooms, and there may be more than one virtual meeting room within a GCC conference. + +The meeting environment is fully configurable through what is termed the "conference framework", allowing users of the protocol freedom to define their own meeting models using the tools provided. Templates show how the framework may be used to model common meeting scenarios, thus allowing service providers or application writers to easily configure potentially complex requirements by selecting from predefined template models. + +This Meeting Room Management Recommendation extends the data management features provided by GCC to include control and management of the real-time aspects (audio and video) of multimedia communication applications. It provides a toolkit of high-level services to control and manage the use of real-time streams within a heterogeneous multipoint communication environment. + +The services range from basic tools such as speaker identification and "on-air" indication functions through to services such as Audio mixing and Floor control which can be used to enhance existing audioconferencing services. The protocol provides the basis for delivering more sophisticated multimedia conferencing services in the future. These features are designed to be used in a wide range of group communication scenarios, ranging from the traditional conference (as typically used for business meetings), through to loosely coupled conferences (e.g. social gatherings in which participants may join and leave discussion groups at will). It also supports more complex requirements (e.g. a convention with a panel of participants who interact, watched by a large audience). Provision is made for autonomous communication sessions (termed "rooms") within a conference (e.g. to allow private side conversations or breakout groups), without requiring a separate conference to be established. + +The goal of this MRM Recommendation is to provide support for a wide range of real-world conferencing scenarios, thus enabling teleconferencing to be more effectively used as a substitute for face-to-face meetings and conferences, while shielding any resulting complexity, from the end user. By defining a number of conference models to support commonly used meeting scenarios, MRM services can be configured to run automatically with minimal user interaction. Conference participants thus gain the benefits of a range of sophisticated services without the burden of having to understand how to configure or control them. + +MRM builds on the strengths of Recommendation T.120 and is thus inherently independent of network and platform. It also overcomes some of the scalability limitations of Recommendation T.120 by allowing use of Anonymous nodes which have minimal interaction with and influence on the conference. Typically, these nodes would be members of an audience. + +MRM services apply within GCC-established conference environment. MRM also provides support for conference participants without T.120 to be supported, as in the case of "Audio only" participants. + +## **7 Meeting room management – Components** + +This MRM Recommendation is realized as T.120 application protocol; it is classified as a Management Application because network element(s) such as MCUs play a key role in the provision of the MRM infrastructure and services specified in the Recommendation. Participants in an MRM conference are however largely unaware of management components involved in provisioning any given conference. Participants communicate through a common management channel to the conference manager, or through a node nominated by the Conference Manager to take on specific responsibilities. + +## **7.1 Virtual meeting rooms** + +The MRM application protocol has the task of integrating the real-time media components with the data conference and providing a seamless conferencing solution to the user. All MRM protocols operate within the context of what this Recommendation terms a "virtual meeting room"; there may be one or more of these virtual meeting rooms within a GCC conference. + +For an MRM conference with only a single virtual meeting room, there is a one-to-one mapping with the GCC conference, and all participants in the GCC conference are participants within the meeting room. However, MRM may also be proxying for non-T.120 nodes. + +Additional virtual meeting rooms effectively provide subgroupings of the GCC conference participants. For each virtual meeting room, the MRM protocol provides separate management tools for all the media components to be used within that virtual meeting room. + +MRM defines a single default meeting room and allows additional rooms to be defined as required. + +Additional meeting rooms may be predefined using the conference framework mechanisms. These rooms are known as "persistent" rooms as they exist for the duration of the conference irrespective of whether there are any participants actually in the room or not. Meeting rooms may also be dynamically created during the conference. The creator may choose if these rooms are to persist or not. By default these rooms are public and are listed in the MRM Room roster. Private virtual meeting rooms may also be created; these do not appear in the roster: they are dynamically created when required and the creator invites the desired participants. + +MRM supports the association of application protocols with a particular meeting room. Once an application protocol is associated with a room, it is only available to the participants of that room. + +## **7.2 The lobby** + +The lobby is a defined space inside the MRM conference but outside of any MRM meeting rooms. Its purpose is to provide a place to discover what rooms are available or a space to create rooms. For participants who already know their room destination, the lobby is transited through on the way to their destination room. New entrants to the lobby receive an MRM conference roster that contains a room list. + +## **7.3 The conference framework** + +The MRM conference framework consists of a comprehensive set of parameters that allow definition of all aspects of an MRM conference, allowing such aspects as scale, management and access regimes and even the look of the conference to be determined. + +The framework allows the creator of the conference (the convenor) the capability to very precisely model a real-world conferencing requirement as a teleconference event. + +The MRM protocol has a default framework configuration built in to it; this is used as a template for the conference, unless a new framework is loaded. It is not necessary to specify a whole new framework in order to adjust individual parameters. Only when framework parameters are defined are they used to override the default framework settings. A "convenor"-defined framework may thus contain as few or as many of parameters as may be required to effect the desired configuration. + +The MRM conference framework consists of three parts. The first part contains the conference configuration template that holds conference wide parameters. The second part contains room constructor templates, and the third part contains service constructor templates. + +The conference configuration may also specify a list of predefined rooms, each specified room being given a unique handle within the framework. The parent room is also specified to allow its relationship with other specified rooms to be understood. Each room may also be given a name and a purpose description. + +Room constructors allow the convenor to specify each room type and the permitted roles within each. Room access controls, governing the participation of a node in a particular role, may also be specified by the convenor. Each defined role may have a role access key specified, allowing the intended role holder, on entry to the conference, to be identified and assigned the intended role. These MRM access keys are defined within room constructors and communicated out of band to the intended role holder(s). When an access key holder joins an MRM conference and provides an MRM access key, the MRM top provider is responsible for allocating that node the correct role or level of participation in the conference room. + +Nodes can be associated into groups, for the purpose of control, with each group being assigned a common access key. An ordered group may be defined to provide, for example, a sequence of presenters. Each member of the group is given a position in the sequence and unique key. + +By using the conference framework, detailed models and regimes can be put in place, allowing the conferencing protocols to be configured for a diverse range of applications without burdening the users of the protocol with significant additional complexity. An MRM conference framework may consist of only a single parameter to be overridden, or it may contain a completely new model and management regime for the MRM conference. + +## **7.4 MRM rosters** + +The MRM roster is a database of configuration and status information that is held and maintained by the MRM top provider for the duration of an MRM conference. Other network elements may shadow the Top Provider role where robust implementations are required. The MRM roster mechanism is independent from the GCC roster. It is designed explicitly to support the needs of the MRM conference protocol. The roster itself consists of two parts: the conference roster and the room roster. The node controller associated with the Top MRM provider acts as the MRM conference manager and is responsible for instructing the Top MRM Provider what information to include in its roster reports. + +### **7.4.1 The MRM conference roster** + +The MRM conference roster contains conference-wide information, relating to the MRM conference and its configuration. This will include framework parameters, either the defaults, or any parameters resulting from a framework-load that have been used to configure the conference. The conference roster can also contain a list of available or active rooms. Each entry corresponds to a room roster where details of individual room configurations and status are stored. + +### **7.4.2 The MRM room roster** + +The MRM room roster contains information on each of the rooms that have been instantiated in a particular conference. For each room listed there will be information about its configuration and operation mode. The associated MRM database also acts as a depository for any room constructor templates that have been defined. For each room listed there will be a state and a mode parameter and also an access regime. Room state will be either inactive if there are no participants, or active if there is one or more participants. The room mode will be either permanent, or persistent, or dynamic. + +### **7.4.3 Roster operation** + +When a node first enters an MRM room, it gets sent a personal copy of the conference roster and also a personal copy of the room roster for the room it is entering. A node entering a room must immediately join the room communication channel specified in order to get room roster updates, which provide incremental changes to the original roster it received. Nodes may also make individual requests of the roster. The roster itself is configurable, allowing the content of roster reports and roster updates to be determined from the specification in the framework, or as a result of a node asking for information through the roster-enquire mechanism. + +### **7.5 Meeting room types** + +This Recommendation defines one standard meeting space, termed the "default meeting room". Provision is also made to allow users to define their own meeting room types. These meeting room types are designed to identify specific types of operational model. They may be considered as handles to identify predefined room constructor templates. + +MRM also defines the lobby, a virtual space inside the MRM session, but outside any MRM meeting room. A Conference communication channel is associated with the lobby and used to distribute + +conference-wide information. The Lobby is not an MRM room and therefore it does not support other media or data sessions. Any node in an MRM session but not in an MRM room is located in the lobby. + +### 7.6 Meeting room modes + +Three meeting room modes are currently supported: + +**Permanent rooms** – Rooms of this type are hardwired into the protocol. Currently the protocol only supports one permanent room, which is used as the default room for the conference. In the case of there only being a single meeting room for the conference, then this room is used and is directly equivalent to the GCC conference. + +**Dynamic Rooms** – Dynamic rooms are created and destroyed as required during the conference. + +**Persistent Rooms** – A persistent room is a special type of dynamically created room that the top provider creates in response to a user requirement or a framework specification. The Top provider joins this room in a purely administrative role to maintain its persistence from its creation time and for the duration of the MRM conference. The MRM top provider does not appear in the room roster for that room. + +### 7.7 Room Hierarchies and relationships + +When a room is created, it may be created as a base level room, or it may be created as a child of an existing room. Child rooms would for example be used for private side communication or for breakout sessions. These child rooms should be regarded as separate virtual spaces within the parent room. If a room is dynamic, then the child must also be dynamic. If a room is persistent, the child may be persistent or dynamic. If the parent is permanent, then the child room may be permanent, persistent or dynamic. When a parent is destroyed, so is the child. A dynamic room is not regarded as empty if it has child rooms which are occupied. The default configuration of the MRM protocol supports a depth of two in the room hierarchy; this allows side communication to take place. The framework parameter for room hierarchy must be set to one to prohibit side communication or to a value greater than two to allow additional levels of hierarchy for more complex scenarios. + +### 7.7.1 Room access regimes + +Currently, the protocol supports three standardized access regimes.4 The creator of a room should specify which is required. In the absence of this parameter the protocol will assume the room is to have "open" access. The supported regimes are: + +**Open** – The default, no admission controls, room appears in MRM-Roster's room list and participants are free to join and leave the room at will. + +**Controlled** – Access is via a password or key. The room appears in the MRM-Roster's room list. + +**Private** – Access is by invitation only. The room details required to gain entry to a room do not appear in the roster, but an indication of all those nodes in private session is obtainable from the roster. Participants who enter by invitation will be returned to the room or place they came from when they leave, unless that room no longer exists, in which case they are placed into the default room. + +### 7.7.2 Room entry regimes + +Private rooms have an entry regime built in that only allows entry by invitation. Open and controlled rooms may be entered directly. However, MRM allows the entry regime of a room to be modified. A room may be configured with an entry regime that does not allow direct entry, but requires entry via + +--- + +4 MRM admission controls are room based and are independent of the GCC mechanisms. + +an automated reception procedure, or via a staffed reception. To avoid the creator being locked out by a prescriptive entry regime, a master key is always created for a room when it is created and it is given to the room creator. This key always provides direct access to that room and can be used to override any other entry requirements. The operator and convenor of the conference also have access to master keys. + +Nodes attempting to enter the room with an indirect entry regime operating and without supplying the master key will be placed in a private reception room. This private space may be used by some form of automated exchange (which is beyond the scope of this Recommendation) or there may be direct interaction with a "door keeper". The role of "door keeper" is by default held by the operator, but may be assigned to a room or conference participant. A room may have one or more "door keepers" assigned to receiving new entrants. A node wishing to enter the room would attempt to enter the room directly. This would result in a "Permission-Ask" being generated and directed to a "door keeper" for the room. The "door keeper" in responding to the request and the incoming node are placed in private conference in the reception room allowing registration, validation, or other procedures required for entry to take place. The "door keeper" has to issue an invitation to that person to get them into the main room. + +### 7.7.3 Room state + +Each MRM room has a state parameter associated with it. Once a room has been created, it takes on the state "created"; once a room is ready to accept entering participants, it enters the "ready" state. When the room is occupied, it enters the "active" state. If a room is terminated before the end of a conference, it maintains an entry in the roster with the state "destroyed". The "suspended" state is a placeholder for future use. + +## 7.8 Classes of participation in a conference + +GCC supports two levels of participation in a T.120 conference: "Conventional nodes" and "Anonymous nodes". MRM utilizes both of these and builds upon them within the MRM protocol. + +Figure 2 identifies three role categories, which are supported by the MRM protocol: + +- Observer roles; +- Participant roles; +- Administrator roles. + +![Diagram showing the relationship between MRM roles and GCC node classifications. It is divided into 'GCC anonymous nodes' and 'GCC conventional nodes'. 'GCC anonymous nodes' includes 'Observer roles' (Observer(s)) under 'MRM room roles'. 'GCC conventional nodes' includes 'Participant' (Chair (Standardized), Presenter (user-defined), Secretary (user-defined)) and 'Administrator' (Operator) under 'MRM room roles'.](51db757d054ce1ce83c436a3578b56ca_img.jpg) + +``` + +graph TD + subgraph Participant + subgraph GCC_conference [GCC conference] + subgraph GCC_anonymous_nodes [GCC anonymous nodes] + subgraph Observer_roles [Observer roles] + Observer_s[Observer(s)] + end + subgraph MRM_room_roles [MRM room roles] + Observer_roles + end + end + + subgraph GCC_conventional_nodes [GCC conventional nodes] + subgraph Participant_roles [Participant] + Chair[Chair +(Standardized)] + Presenter[Presenter +(user-defined)] + Secretary[Secretary +(user-defined)] + end + subgraph Administrator_roles [Administrator] + Operator[Operator] + end + subgraph MRM_room_roles_conventional [MRM room roles] + Participant_roles + Administrator_roles + end + end + end + end + +``` + +Diagram showing the relationship between MRM roles and GCC node classifications. It is divided into 'GCC anonymous nodes' and 'GCC conventional nodes'. 'GCC anonymous nodes' includes 'Observer roles' (Observer(s)) under 'MRM room roles'. 'GCC conventional nodes' includes 'Participant' (Chair (Standardized), Presenter (user-defined), Secretary (user-defined)) and 'Administrator' (Operator) under 'MRM room roles'. + +T1607360-99 + +**Figure 2/T.137 – Relationship between MRM roles and GCC node classifications** + +The observer role maps directly onto a GCC anonymous node, while the participant and administrator roles map onto the GCC conventional node classification. A participant role holder may also take on additional role responsibilities by taking on Chair, Presenter, or Secretary responsibilities as appropriate. + +### **7.8.1 MRM observers** + +The role of MRM observer has a direct equivalence to a GCC anonymous node. The "observer" class is provided to allow participants who are primarily observers to join conference and enter rooms. This class can be considered as a special role. Support or exclusion of observers may be specified in advance in the conference framework. When a terminal joins a conference it may specify it wishes to join as an observer, or its invitation may contain conference and room access parameters which only allow access and participation as an observer. The observer role is automatically assigned to a node enrolling as a GCC Anonymous node in the conference. It is anonymous to the other participants in that it does not appear in the conference or room rosters. However, the conference can be configured so the chair/convenor/secretary gets notification of an observer joining and leaving. An observer is primarily a viewer and this role can be used as an aid to scalability or as a means for restricting input to the conference. Typically, observers would not be able to participate interactively in a conference unless explicitly granted permission through use of the floor control service. Observers are by default able to see and hear the exchanges within the room that they are in. The MRM protocol supports the capability for managed input by an observer to the proceedings within a room. Where permitted, an observer could make a request to the chair to ask a question or to use a data application. This classification provides support for the observer requirement as well as supporting participation scalability for conferencing applications. One example of appropriate use of the observer role would be in support of a delegate at a convention. + +### **7.8.2 MRM participants** + +An MRM participant is a conventional T.120 node and is able to fully participate and interact within the GCC conference. MRM inherits the GCC conventional node capabilities and allows MRM participants to participate and interact fully within a meeting room. A participant has access to, and may take on, additional supplementary roles which bring added privileges and responsibilities; for example, the chair role makes the role holder the focal point of the floor control protocol. The MRM conference manager provides a proxy for non-T.120 nodes such as "audio-only" participants, allowing them to participate as "audio-only" participants. + +#### **7.8.2.1 Supplementary conference room roles** + +This MRM Recommendation defines a number of regular participant roles which may be used to accord particular conference participants with additional privileges and status with respect to use of MRM services. Users may also define their own roles using the privilege tables provided by MRM. Every role has an associated set of rules to support its intended use. MRM services are aware of the active roles within a room and will modify their behaviour to accommodate the requirements and privileges. The protocol allows roles to be preassigned and held by nodes in an inactive state until needed; alternatively they may be dynamically acquired. Unlike the GCC conductor role, MRM roles are used within the context of a meeting room and have a scope covering all the media used within that meeting space. + +##### **7.8.2.1.1 Chair role** + +The chair role is provided to allow a node to become the chairperson for a particular meeting room. The chairperson is a participant and has responsibility for managing the floor-control procedures within that room. Where multiple rooms are permitted, each room may have its own chair role. The MRM chair for the base room may be aligned with the GCC conductor by synchronizing MRM with the data session. + +The chair has the following privileges available to it: + +- Activation/deactivation of floor control; +- Operation of floor control; +- The ability to invite/eject audio-only participants – *plus the ability to determine if they join direct or via a private conference with chair or an entry lobby*; +- The ability to invite/cancel invitation to an operator – *Either audio only or audio with data*. + +##### **7.8.2.1.2 Convenor role** + +The convenor of an MRM controlled conference is also the GCC convenor. It would typically be the convenor who defined any conference framework associated with the conference. Conferences are convened using GCC primitives that make explicit provision for MRM parameters. + +### **7.8.3 MRM administrators** + +The MRM protocol currently supports only one administrator role: that of the "operator". The operator role is provided to support conference offered as part of a managed service. Where permitted, the role can be taken on by an external management/helper in order to support/educate and problem-solve, for conference participants. + +The operator joining a conference takes on this special system role of operator. It is a predefined role that specifies how a service operator can interact with a conference meeting room session. The privileges associated with this role are: + +- An operator cannot be muted and will be mixed by the audio bridge (*where audio is present*). +- The operator can take on the chair role if needed and can eject participants. +- The operator may have access to data content for the room restricted. + +There is no protocol limit to the number of operators who may join a conference or enter a virtual room. This is a local matter for the service provider. + +### **7.8.4 MRM groups** + +The MRM protocol supports the ability to associate participants to form MRM groups. The purpose of a group may be specified explicitly or determined by the framework that is in use. A group can be used to manage communication and information distribution between group members who are participating in a conference. Groups are primarily designed to be used within the context of a room, but where appropriate and with caution they may be allowed scope across rooms within a single conference. MRM groups, like rooms, form a partitioning of conference members; however, this is not for separate and autonomous communication. The group is simply a means to associate participants within the room. The group mechanism aims to provide support for a diverse range of requirements. Each group that is created has its own private communication channel. + +Two standard group types are supported. The first type of group is termed a "team". A room may support many teams. The chair protocol is aware of groups and can interact at a group level, for example giving a group permission to speak rather than an individual. A team may be used to represent a panel of experts or one team in a competition. Teams may be used to group companies together in a meeting or distinguish between locations. The other type of group supported is an "ordered" group; this may be used to represent an ordering of presenters for an event, or responsibility for topics on a meeting agenda. Each member of an ordered group is assigned a sequence number. Where an ordered group of presenters is defined, the role when released, automatically moves down the sequence to the next in the group. + +Groups can be used as the context for services and roles within a selected conference framework. Group management functionality provided by MRM includes group create/disband, group join/leave + +(allowing unregulated group access) and group add/remove node (allowing an authorized node to control group membership). A group membership list is held by the MRM top provider in the room roster and is available to terminals on request. Within a group the following functions would be supported in respect of the roles: the ability to assume, relinquish and assign a role, plus the ability to activate and deactivate a role holder. + +### **7.9 MRM conference services** + +MRM conference services are blocks of related functionality provided by one or more network elements to the MRM conference. MRM supports the standardization of services, an example of this being the audio bridging service. MRM also supports the user-defined services which can be negotiated in the MRM application capabilities as the application enrolls. + +An MRM conference has a standard default conference framework hard-wired into the protocol to ensure that basic interoperability can be achieved; this default serves as a fallback operational mode and specifies baseline functionality that must be supported in order to be MRM compliant. By default, no MRM conference services are required. The MRM conference service provider is able to modify virtually all of the default framework parameters, and, by loading a new framework specification, the functionality available can be further restricted or enhanced. When a framework is loaded into a conference, the MRM defaults are overridden and replaced by the new settings. A service provider is able to set a framework flag Update Default Framework, which causes the framework loaded outside a specific conference to be stored and used in preference to the standard default. + +Each MRM service will have an operational requirement and an operational state. Each MRM service will have one of the following operational requirements assigned to it: "Required", "Offered", "Restricted", "Prohibited". The standard default framework does not list any MRM services. If an application capability exchange identifies capability, this is appended to the room roster for the nodes. The capability will itself provide the operational requirement for a given service. If a new framework is loaded, then this may contain a list of MRM services each of which will have an operational requirement. Any service list provided by a framework will become part of the conference and room rosters as appropriate. When a node joins a room it receives a room roster which tells it which services are Active, and of those that are active, which are required and which are offered but are optional, and also which services (if any) are inactive but are available for activation. + +Authority to issue service commands to activate and subscribe to services is also determined by the framework. Even where a service is required, this requirement only applies for nodes capable of supporting the media being used by the service; e.g. an audio node would not be required to support a video-based service. + +### **7.10 Starting an MRM conference** + +When a GCC conference is created to support an MRM application, the node controller at the GCC top provider is responsible for launching the MRM application protocol. This node also becomes the MRM top Provider and its node controller takes on the role and responsibilities of the MRM Conference Manager.5 The MRM Top provider takes on the creation and management of the MRM rosters. The Top MRM provider holds a default configuration for an MRM conference, effectively a default framework, built into the protocol. This default framework allows the creation of additional rooms and roles. Loading a new framework at the time the conference is created allows default settings to be modified. Participants entering the conference will receive the MRM roster directly + +--- + +5 If the Top GCC provider does not support MRM, it is possible for another network element to take on the role, but this is not the recommended mode of operation. + +from the MRM conference manager, which contains information on the conference configuration as well as information on the rooms available within the conference. + +When a participant enters a room, he will receive a room roster from the top provider; the framework then determines what is permitted within that room. + +### **7.10.1 Private side communication** + +By default, only a single room will exist and all terminals participating in an MRM-managed conference will interact with each other within a single MRM communication session, which the MRM protocol represents as a Virtual meeting room. However, in some scenarios, there may be a requirement for separate autonomous audiovisual and data communications within the same conference. For example, in a business meeting there may be a requirement for private side conversations, whilst a social gathering may consist of a number of discussion groups which participants join according to their interest in the topic of conversation. MRM supports these requirements by allowing multiple communication spaces (virtual meeting rooms) to be established within a single T.124 conference. MRM rooms are advertised using MRM's own roster mechanisms. + +### **7.10.2 Relationship between meeting rooms and data sessions** + +An MRM conference consists of a single MRM application session in which one or more virtual meeting rooms are established. MRM services are provided in the context of Virtual Meeting Rooms. The MRM application session is realized as a T.124/T.121 application protocol session. MRM also supports child rooms (which have no direct T.124 equivalent), allowing side conferencing or separate communicating groups to exist within a meeting space. When a node joins an MRM session it will, by default, enter the default meeting room, transiting through the lobby and receiving a conference roster, unless a framework access key causes it to be directed to another room. On entering a room, a participant is automatically subscribed to (and may thus make use of) the active services within that room. Inactive services must be subscribed to explicitly. The interpretation of subscribing a node to a service is service specific. + +The MRM protocols are designed to provide support in managing a diverse range of teleconference scenarios. To facilitate this, MRM provides a number of commonly used conference models, each tailored for use in a particular type of meeting environment. When creating a conference, a convenor may select a conference model appropriate for the desired scenario. The requirements of this model are then conveyed to other participants through the definition of a conference framework – a set of parameters – which effectively defines a management regime under which the conference operates. User-defined conference models may also be used if required; the conference convenor simply selects an appropriate set of framework parameters, which can also be used to create new templates allowing for reuse. + +The conference framework philosophy allows the conference convenor to establish potentially complex conference scenarios, without exposing participants to the complexity of configuring or using the associated conference services. The provided conference models simplify the task of the convenor for commonly required scenarios, and also greatly simplify the task of repeating a conference based upon templates already defined. + +MRM defines three general classifications for group communication rooms: the Meeting Room Model, the Conference Room Model, and the Coffee Room Model. These classifications are used to label a set of parameters that configure an MRM room in support of a particular application requirement. If these basic models are not sufficient, then users of the protocol are free to provide their own parameter groupings in order to tune the room configuration and management regime to meet their own requirements. + +### 7.10.3 Role and relationship to the GCC conductor + +Some existing data applications make use of the GCC conductor: for the default room the MRM chair and GCC conductor are aligned. When multiple rooms are used, the MRM room chair mechanisms are required and the GCC conductor is no longer relevant.6 + +### 7.10.4 MRM management nodes + +The MRM top provider is the node responsible for managing the MRM conference. Other management nodes may assist the top provider in delivering the conference. Participants are shielded from conference administration issues as they always communicate to the conference management through a common management channel. Typically, management nodes are network elements such as MCUs. + +### 7.10.5 Proxying MRM functionality + +Pre-MRM terminals will still be able to benefit from MRM functionality where another node (network element) is able to proxy on its behalf. Proxying may also be used to support receive-only terminals. + +The realization of a proxy agent is a local matter. The problem of knowing where to send control and indications destined for a proxied terminal is handled by T.120. The proxy agent uses the GCC mechanisms to obtain a User ID for its terminal(s). MCS can then correctly route management and control information directed to that terminal, irrespective of the topology. + +It is also feasible to allow MRM protocols to arrive from some out-of-band mechanism and be introduced into the conference by a proxy agent that is proxying for T.120. This again is a local matter. An example of this would be a convenor needing to interact with an ongoing conference from a reservation system/terminal. Another example would be a basic audio/video-only terminal that had no data or conference management requirements, but could still benefit from the functionality of an MRM-managed conference. + +# 8 T.137 infrastructure management functionality + +## 8.1 Use Of MCS channels + +A single MCS channel – the "Room Participant Communications" channel – represents the virtual meeting room. This MCS channel ID is used to provide a unique identifier for the room. When a room is instantiated from a framework, the pre-assigned room handle will be associated with the MCS channel identifier for that room and both will then be accepted as valid identifiers for that room. + +For a multipoint conference with just the default meeting room, the MRM application utilizes three MCS static channels to provide management and control services in support of the MRM conference. Each additional room requires an MCS dynamic channel for participant communication and, optionally, a second dynamic channel for observer communication when required. + +## 8.2 Static channels + +**MRM-Conference-Management-Channel** – It is joined by the top MRM provider and may also be joined by other network nodes that are cooperating to delivering MRM services to the conference. Participating nodes send to this channel in order to communicate with the service management node running the MRM conference. The participants themselves do not need to be aware of which node is actually running the conference; they always send to this well known static channel ID, which + +--- + +6 Changes in GCC and or data apps may be required to fully exploit the capabilities of the MRM protocol. + +provides a standard way for communication, independent of the conference topology. It effectively allows client terminals to see the network as a single virtual network element. This mechanism also allows other network elements to shadow or even take over the role of MRM top provider without the need to tear down the conference. + +**MRM-Conference-Communication-Channel** – It is joined by the MRM provider at terminal nodes when they enrol active in the MRM session. It is used to deliver the conference roster and to broadcast information to all MRM participants, irrespective of which room they are in. + +**MRM-Default Room-Participant-Communication-Channel** – All client nodes wishing to participate in the default room join this channel, and it is used to distribute information within the room. The top MRM Provider uses this channel to broadcast to the room. GCC conventional nodes that have entered the room as participants may also send to this channel in accordance with the MRM protocol rules. + +**MRM-Default-Room-Observer-Communication-Channel** – It is only required when a room has observers taking part. It may be used by the top MRM provider to send status and other broadcast information targeted at the observers in the room. A separate channel is used to allow partitioning of different levels of information and thus aids scalability for conferences, which have many observers involved. + +## 8.3 Dynamic channels + +In addition to the static channels, the MRM application makes use of one or more dynamic channels in the support of each additional meeting room, which mirror the static communication channels for the static room. + +**MRM-Room-Participant-Communication-Channel** – Each additional meeting room requires its own dynamically allocated MCS channel which is used to broadcast status updates to all the participants in that room. Each room may also have a pre-assigned identifier defined within the framework and outside of the protocol. + +**MRM-Room-Observer-Communication-Channel** – Each additional meeting room may also require its own dynamically allocated MCS channel for observer communications when a room is required to support observers. It may be used by the top MRM provider to send status and other broadcast information targeted at the observers in the room. As with the static provision, a separate channel allowing the partitioning of different levels of information and thus aiding scalability for conferences which have many observers involved. + +# 9 MRM infrastructure management service definition + +### 9.1 Summary of MRM abstract services + +Table 1 is a list of all MRM infrastructure management primitives and their associated PDUs. The table also shows whether or not each primitive is mandatory (M), conditionally required (C), or optional (O) for an MRM terminal or for an MRM network element. The table also shows, for the corresponding PDUs, whether these are mandatory (M) or conditionally required (C) for both the transmit (T) and receive (R) directions. A conditionally required PDU is one, which is required only if the corresponding primitive is to be supported at that node. Where a primitive is not mandatory, but its corresponding PDU is mandatory, this implies that there is some portion of the protocol not related to the primitive that relies on the use of that PDU which is required to be supported. + +**Table 1/T.137 – MRM infrastructure management primitives and PDU** + +| Function Unit | Primitives | Observer Terminal | Participant Terminal | Network Element | Associated PDUs | Direction | Observer Terminal | Participant Terminal | Network Element | +|---------------------|--------------------------------------|-------------------|----------------------|-----------------|----------------------------|-----------|-------------------|----------------------|-----------------| +| Framework | MRM-Launch request | – | – | M | – | – | – | – | – | +| | MRM-Launch confirm | – | – | M | – | – | – | – | – | +| | MRM-Framework-Load request | – | – | M | – | – | – | – | – | +| | MRM-Framework-Load confirm | – | – | – | – | – | – | – | – | +| | – | – | – | – | FrameworkLoadIndication | T | – | – | M | +| | – | – | – | – | FrameworkLoadIndication | R | – | – | M | +| MRM Rosters | MRM-Roster-Report request | – | – | M | RosterReportIndication | T | – | – | M | +| | MRM-Roster-Report indication | O | M | M | RosterReportIndication | R | O | M | M | +| | MRM-Roster-Update indication | – | M | O | RosterUpdateIndication | T | – | – | M | +| | | | | | RosterUpdateIndication | R | – | M | M | +| | MRM-Roster-Enquire request | O | O | O | RosterEnquireIndication | T | O | O | O | +| | | | | | RosterEnquireIndication | R | – | – | M | +| Room Management | MRM-Room-Create request | – | O | M | RoomCreateRequest | T | – | O | M | +| | | | | | RoomCreateRequest | R | – | – | M | +| | MRM-Room-Create confirm | – | C | M | RoomCreateResponse | T | – | – | M | +| | | | | | RoomCreateResponse | R | – | C | M | +| | MRM-Room-Enter request | M | M | O | RoomEnterRequest | T | M | M | M | +| | MRM-Room-Enter indication | – | – | M | RoomEnterRequest | R | – | – | M | +| | MRM-Room-Enter response | – | – | M | RoomEnterResponse | T | – | – | M | +| | MRM-Room-Enter confirm | M | M | O | RoomEnterResponse | R | M | M | M | +| | | | | | RoomReadyIndication | T | M | M | M | +| | | | | | RoomReadyIndication | R | – | – | M | +| | MRM-Room-Invite request | – | O | O | RoomInviteIndication | T | – | O | M | +| | MRM-Room-Invite indication | – | M | M | RoomInviteIndication | R | M | M | M | +| MRM Groups | MRM-Group-Create request | – | O | M | GroupCreate Request | T | – | O | M | +| | | | | | GroupCreateRequest | R | – | – | M | +| | MRM-Group-Create confirm | – | C | M | GroupCreateResponse | T | – | – | M | +| | | | | | GroupCreateResponse | R | – | C | M | +| | MRM-Group-Disband request | – | O | M | GroupDisbandRequest | T | – | O | M | +| | | | | | GroupDisbandRequest | R | – | – | M | +| | MRM-Group-Disband confirm | – | C | M | GroupDisbandResponse | T | – | – | M | +| | | | | | GroupDisbandResponse | R | – | C | M | +| | MRM-Group-Membership-Specify request | – | O | M | GroupMemberSpecifyRequest | T | – | O | M | +| | | | | | GroupMemberSpecifyRequest | R | – | – | M | +| Service Support | MRM-Group-Membership-Specify confirm | – | C | M | GroupMemberSpecifyResponse | T | – | – | M | +| | | | | | GroupMemberSpecifyResponse | R | – | C | M | +| | MRM-Service-Command request | – | O | M | ServiceCommandRequest | T | – | O | M | +| | MRM-Service-Command indication | – | – | M | ServiceCommandRequest | R | – | – | M | +| | MRM-Service-Command confirm | – | C | M | ServiceCommandResponse | T | – | – | M | +| | | | | | ServiceCommandResponse | R | – | C | M | +| | MRM-Session-Associate request | – | O | M | SessionAssociateRequest | T | – | O | M | +| | MRM-Session-Associate indication | – | – | M | SessionAssociateRequest | R | – | – | M | +| Session Association | MRM-Session-Associate confirm | – | O | M | SessionAssociateResponse | T | – | – | M | +| | | | | | SessionAssociateResponse | R | – | O | M | + +**Table 1/T.137 – MRM infrastructure management primitives and PDU (concluded)** + +| Function Unit | Primitives | Observer Terminal | Participant Terminal | Network Element | Associated PDUs | Direction | Observer Terminal | Participant Terminal | Network Element | +|-----------------------|---------------------------------------|-------------------|----------------------|-----------------|-------------------------------|-----------|-------------------|----------------------|-----------------| +| Room Role Assignment | MRM-Room-Role-Assign request | – | O | M | RoomRoleAssignRequest | T | – | O | M | +| | | – | – | | RoomRoleAssignRequest | R | – | – | M | +| | | – | – | | RoomRoleAssignResponse | T | – | – | M | +| | MRM-Room-Role-Assign confirm | – | O | M | RoomRoleAssignResponse | R | – | O | M | +| | MRM-Room-Role-Release request | – | O | M | RoomRoleReleaseRequest | T | – | O | O | +| | | – | – | | RoomRoleReleaseRequest | R | – | – | M | +| | | – | – | | RoomRoleReleaseResponse | T | – | – | M | +| | MRM-Room-Role-Release confirm | – | O | M | RoomRoleReleaseResponse | R | – | O | O | +| | MRM-Room-Role-Please request | – | O | – | RoomRolePleaseRequest | T | – | O | – | +| | MRM-Room-Role-Please indication | – | O | M | RoomRolePleaseRequest | R | – | M | M | +| | | – | – | | RoomRolePleaseResponse | T | – | M | M | +| | MRM-Room-Role-Please confirm | – | O | – | RoomRolePleaseResponse | R | – | O | – | +| | MRM-Room-Role-Give request | – | O | – | RoomRoleGiveRequest | T | – | O | O | +| | MRM-Room-Role-Give indication | – | O | M | RoomRoleGiveRequest | R | – | O | M | +| | | – | – | | RoomRoleGiveResponse | T | – | O | M | +| Permission To Act | MRM-Room-Role-Give response | – | O | M | RoomRoleGiveResponse | R | – | O | O | +| | MRM-Room-Role-Give confirm | – | O | – | RoomRoleGiveIndication | T | – | O | M | +| | | – | – | | RoomRoleGiveIndication | R | – | O | M | +| | MRM-Role-Permissions-Modify request | – | C | M | RolePermissionsModifyRequest | T | – | C | M | +| | | – | – | | RolePermissionsModifyRequest | R | – | – | M | +| | | – | – | | RolePermissionsModifyResponse | T | – | – | M | +| | MRM-Role-Permissions-Modify confirm | – | C | M | RolePermissionsModifyResponse | R | – | C | M | +| | MRM-Permission-Ask request | O | M | – | PermissionAskRequest | T | O | M | – | +| | MRM-Permission-Ask indication | – | M | – | PermissionAskRequest | R | – | M | – | +| | MRM-Permission-Ask confirm | O | M | – | | | | | | +| Source Identification | MRM-Permission-Relinquish request | O | M | – | PermissionRelinquishRequest | T | O | M | – | +| | MRM-Permission-Relinquish indication | – | M | – | PermissionRelinquishRequest | R | – | M | – | +| | MRM-Permission-Relinquish confirm | O | M | – | | | | | | +| | MRM-Permission-Grant request | – | M | M | PermissionGrantRequest | T | – | M | – | +| | MRM-Permission-Grant indication | O | M | M | PermissionGrantRequest | R | M | M | – | +| | MRM-Permission-Grant confirm | – | M | M | | | | | | +| Privacy | MRM-Source-Identification request | O | M | M | SourceIdentificationRequest | T | O | M | M | +| | MRM-Source-Identification indication | O | M | M | SourceIdentificationRequest | R | O | M | M | +| | MRM-Source-Identification confirm | O | M | M | | | | | | +| | MRM-On-Air-Indication request | O | M | M | OnAirIndicationRequest | T | O | M | M | +| Audio Mixing | MRM-On-Air-Indication indication | O | M | M | OnAirIndicationRequest | R | O | M | M | +| | MRM-Privacy-Notify request | – | O | M | PrivacyNotifyRequest | T | O | M | M | +| | MRM-Privacy-Notify indication | – | O | M | PrivacyNotifyRequest | R | O | M | M | +| | | – | – | | PrivacyNotifyResponse | T | – | – | M | +| Telephony Support | MRM-Privacy-Notify confirm | – | O | M | PrivacyNotifyResponse | R | – | – | M | +| | MRM-Audio-Mix-Report request | – | – | M | AudioMixReportRequest | T | – | – | M | +| | MRM-Audio-Mix-Report indication | M | M | M | AudioMixReportRequest | R | – | M | M | +| | MRM-Audio-Mixer-Set request | – | M | M | AudioMixerSetRequest | T | – | M | M | +| | MRM-Audio-Mixer-Set indication | – | – | M | AudioMixerSetRequest | R | – | – | M | +| Telephone Support | | – | – | | AudioMixerSetResponse | T | – | – | M | +| | MRM-Audio-Mixer-Set confirm | – | M | M | AudioMixerSetResponse | R | – | M | M | +| | MRM-Invite-Audio-Only-Node request | – | O | M | InviteAudioOnlyNodeRequest | T | – | O | M | +| | MRM-Invite-Audio-Only-Node indication | – | – | M | InviteAudioOnlyNodeRequest | R | – | – | M | +| | MRM-Invite-Audio-Only-Node response | – | – | M | InviteAudioOnlyNodeResponse | T | – | – | M | +| | MRM-Invite-Audio-Node-Only confirm | – | O | M | InviteAudioOnlyNodeResponse | R | – | O | M | +| | MRM-Eject-Audio-Only-Node request | – | O | M | EjectAudioOnlyRequest | T | – | O | M | +| | MRM-Eject-Audio-Only-Node indication | – | – | M | EjectAudioOnlyRequest | R | – | – | M | +| | MRM-Eject-Audio-Only-Node response | – | – | M | EjectAudioOnlyResponse | T | – | – | M | +| | MRM-Eject-Audio-Only-Node confirm | – | O | M | EjectAudioOnlyResponse | R | – | O | M | +| | MRM-Call-Status request | – | C | M | CallStatusIndication | T | – | – | M | +| | MRM-Call Status indication | – | – | M | CallStatusIndication | R | – | C | M | + +## 9.2 Establishing the MRM Top provider + +Where the MRM protocols are used as part of a managed service, the MRM top provider should be co-located with the GCC and MCS top providers, the location of which may be defined by the service. In other cases where arbitrary allocation of top provider can occur, MRM provides an optional procedure using an MCS Token to determine which node takes on the MRM top provider role. + +An MRM provider intending to participate as a Network Element and that is capable of becoming the MRM top provider should check the state of a *local* flag to determine if it needs to compete for the top provider role. This flag may be hardwired, or set as part of the node's configuration, but this is a local matter. Without *a priori* knowledge, nodes should by default be configured to compete for the role. Where this mechanism is used, nodes attempt to grab the MCS token assigned to the MRM top provider (MRM-Token-0). The node that is successful is required to become the MRM top provider, unless a request is made for the token by a node higher in the tree. + +In all cases it is highly desirable that the MRM top provider should be co-located with the GCC/MCS top provider; however, this mechanism also allows the possibility of the MRM top provider being at a different node. Although this is not recommended and it may adversely affect the performance of the protocol, neither is it prohibited by the protocol. This is because the possibility exists that the GCC top provider may not support MRM. Where such cases arise, the MRM top provider should be as close as possible to the top of the tree hierarchy. + +#### Creation of an MRM controlled conference + +When a GCC conference requiring MRM functionality is created, the conference manager at the top provider launches the MRM application protocol and at the same time tells the provider if it intends to load a new framework. In cases where a new framework is to be loaded, the MRM top provider will be required to wait for it to be loaded before proceeding to enrol the application protocol entity. + +Client nodes joining the GCC conference see the availability of MRM functionality through the GCC application roster. Nodes that support the MRM application should, at this stage, enrol their MRM Application Protocol Entity. Enrolment results in that node being sent a personal copy of the MRM conference roster. Nodes enrolled in the MRM conference arrive in the lobby, a defined space outside of any MRM room. They must then use the room entry procedures to enter an MRM room. Where there is more than one room in a conference, nodes may, subject to permission, use the conference roster room list to find and enter rooms. When a node enters a room, it will also receive the roster for that room. + +The use of MRM services ideally requires MRM to be present at the top provider node and all network elements within the conference. Terminals are not required to support MRM in order for the MRM protocol to operate, although its absence is likely to give reduced functionality. Network elements may choose to proxy MRM functionality for non-MRM capable terminals; how this is achieved is outside the scope of this Recommendation. + +### 9.3 MRM conference framework + +Table 2 below defines the conference framework parameters that may be used in an MRM-Framework-Load primitive. The table also shows the default values for each. Every network element that is capable of becoming an MRM top provider holds a copy of these default values, and in the absence of a new framework, uses them when setting up an MRM conference. + +The framework supports many parameters, allowing a great deal of flexibility to configure an MRM conference. However, virtually all of these framework parameters are optional, and typically a new framework will contain only a few parameters needed to modify the default configuration to meet the user's requirements. This is because in the absence of a parameter, the top provider will continue to use the default framework value. + +The "New Default Framework" flag allows the possibility for the convenor to tell the MRM top provider to use a new framework to permanently replace the standard defaults. This helps in the situations where the convenor always requires a particular framework configuration from an MRM top provider. The conference framework consists of three parts. The first part contains the conference specification template – a set of parameters that may be used to specify conference-wide parameters. One of these parameters provides a place to list any room constructors needed to realize rooms for the conference. The second part of the conference framework holds the room constructors definitions that the conference specification refers to. Another of the parameters contains a list of predefined rooms; each predefined room must be based upon the default or a room constructor defined within the framework. Constructors may be defined that are not used to create predefined rooms. These constructors serve as room templates and can be made available to participants, for use in a conference. The conference specification also includes a list of services available to the conference. Each service is either based upon the default configuration for that service or a Service constructor that will be defined in the third part of the conference framework. + +**Table 2/T.137 – MRM conference framework parameters** + +| Conference Framework | | | | | | +|---------------------------------------|---------------------------------------------------------------|----------|--------------|---------|-----| +| PARAMETER NAME | Description | Range | Unit | Default | Key | +| Conference Name | Human-readable name for conference | – | String | Null | O | +| Conference Description | Human-readable description for conference | – | String | Null | O | +| Conference Model | User-defined parameter | | Key | 0 | O | +| Max Conventional Nodes Permitted | Enforced limit on number of participants | 0-8191 | | 128 | O | +| Max Anonymous Nodes Permitted | Enforced limit on number of observers | 0-16 383 | | 512 | O | +| Permitted Services List | List of services permitted | – | Service IDs | Audio | O | +| Permitted Roles List | List of roles which may be used | – | Role IDs | Chair | O | +| Synchronize with Data Conference Flag | Flag to indicate if data sessions should get role information | – | Flag | FALSE | O | +| Groups Permitted Flag | Flag to indicate if groups may be used | – | Flag | FALSE | O | +| Prohibited functions | List of functions that participant nodes may not send | – | List of PDUs | None | O | +| Max number of Rooms | Limit of the number of rooms in conference | 1-255 | Integer | 16 | O | +| Max Depth of Rooms | | 1-7 | Integer | 2 | O | +| Number of Predefined Rooms | Indicates how many room constructors are to follow | 0-255 | Integer | 1 | O | +| Predefined Room List consisting of: | | | | | | +| Room Handle | Framework's handle for room | 0-65 535 | Integer | 0 | O | +| Room Constructor ID | ID for room constructor to be used | 0-65 535 | Integer | 0 | O | +| Room Parent | Framework handle for parent room | 0-65 535 | Integer | 0 | O | +| Room Name | Name of room | | Integer | NULL | O | +| Room purpose | Human-readable description of room purpose | | String | NULL | O | + +**Table 2/T.137 – MRM conference framework parameters (concluded)** + +| Conference Framework | | | | | | +|----------------------------------------------------|------------------------------|-------|---------|-------------------|-----| +| PARAMETER NAME | Description | Range | Unit | Default | Key | +| Participant Conference Roster Reporting parameters | Use Detailed Reports | – | Boolean | FALSE | O | +| | Include Configuration | – | Boolean | FALSE | O | +| | Include Status | – | Boolean | TRUE | O | +| | Include Participants List | – | Boolean | FALSE | O | +| | Include Participants Details | – | Boolean | FALSE | O | +| | Allow Roster Enquiry | – | Boolean | FALSE | O | +| Participant Room Roster Reporting parameters | Use Detailed Reports | – | Boolean | FALSE | O | +| | Include Configuration | | Boolean | FALSE | O | +| | Include Status | | Boolean | TRUE | O | +| | Include Participants List | | Boolean | TRUE | O | +| | Include Participants Details | | Boolean | FALSE | O | +| | Include room Templates | | Boolean | FALSE | O | +| Observer Conference Roster Reporting parameters | Use Detailed Reports | – | Boolean | FALSE | O | +| | Include Configuration | – | Boolean | FALSE | O | +| | Include Status | – | Boolean | TRUE | O | +| | Include Participants List | – | Boolean | FALSE | O | +| | Include Participants Details | – | Boolean | FALSE | O | +| Observer Room Roster Reporting parameters | Use Detailed Reports | – | Boolean | FALSE | O | +| | Include Configuration | – | Boolean | FALSE | O | +| | Include Status | – | Boolean | TRUE | O | +| | Include Participants List | – | Boolean | TRUE | O | +| | Include Participants Details | – | Boolean | FALSE | O | +| | Include room Templates | – | Boolean | FALSE | O | +| Room Constructor List | See Table 3 | – | – | Default room only | O | +| MRM Service Framework | See Table 4 | – | – | No services | O | + +**Table 3/T.137 – MRM conference framework – Room constructors** + +| Room Constructor | | | | | | +|-------------------------|-------------------------------------|----------|------------|------------|-----| +| Parameter | Description | Range | Unit | Default | Key | +| Room Constructor Handle | Unique identifier for constructor | 0-65 535 | Integer | 0 | M | +| Framework Room ID | Unique identifier for room | 0-65 535 | Integer | 0 | C | +| Room Name | Human-readable string | – | String | Null | O | +| Room Purpose Descriptor | Human-readable string | – | String | Null | O | +| Room Type | Choice of Lobby, Meeting Room, etc. | | Enumerated | Default | O | +| Room Mode | Permanent, Persistent or Dynamic | | Enumerated | Persistent | O | +| Room Parent | Framework Room ID | – | 0-65 535 | 0 | O | + +**Table 3/T.137 – MRM conference framework – Room constructors (*concluded*)** + +| Room Constructor | | | | | | +|-----------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------|----------|------------|-----------------|-----| +| Parameter | Description | Range | Unit | Default | Key | +| Room Management Regime | No chair/chair available/chair active, etc. | – | Enumerated | Chair Available | O | +| Room Management Style | Informal/Formal/Loosely coupled, etc. | – | Enumerated | Informal | O | +| Room Media | Choice of one or more of the following: Audio, Video, Data, Real-time data | – | Enumerated | Audio, Data | O | +| Room Access Model | Choice of Open, Controlled, or Private | – | Enumerated | Open | O | +| Room Entry Regime | Enter Direct/Via chair/Via lobby | – | Enumerated | Direct | O | +| Room Exit Regime | Exit to previous/to lobby/exit conf | – | Enumerated | To Previous | O | +| Child Rooms Permitted | Flag indicating if child rooms are allowed | – | Flag | TRUE | O | +| Max Participants Permitted | Enforced limit on participants in room | 0-16 383 | Integer | 128 | O | +| Max Observers Permitted | Enforced limit on observers in room | 0-16 383 | Integer | 512 | O | +| Participant Access Key | A password assigned in framework | – | Password | Null | O | +| Observer Access Key | A password assigned in framework | – | Password | Null | O | +| Groups Permitted | Flag indicating if group functionality is available | – | Flag | FALSE | O | +| Chair Required Flag | Flag indicating if chair is required | – | Flag | FALSE | O | +| Chair Access Key | A password assigned in framework | – | Password | Null | O | +| Operator Required Flag | Flag indicating if operator is required | – | Roles IDs | FALSE | O | +| Operator Access Key | A password assigned in framework | – | Password | Null | O | +| Groups Required List | List of named groups | – | Group IDs | FALSE | O | +| Group Access Key(s) | List of groups access keys | – | Password | FALSE | O | +| Audio Support Required flag
Audio only support | | – | Flag | TRUE | O | +| | | – | Flag | TRUE | | +| User-defined Role Specification | | | | | O | +| Floor control Required Flag | | – | Flag | FALSE | O | +| MRM Service list:
– Service Identifier
– Service Requirement
– Participation Requirement
– Observer Requirement | | | | | O | + +**Table 4/T.137 – Service framework – Audio bridging parameters** + +| Audio Bridging – Service Constructor | | | | | | | +|---------------------------------------------------|-----------------|-------------------------------------------------------------------------------------------|-------|------------|-----------|--------| +| Parameter name | Scope | Description | Range | Unit | Default | Key | +| Service Constructor Handle | | A standard key for standardized services and a non-standard key for User-defined services | – | Key | 0 | M | +| Audio Mode | Terminal | Mono, Stereo, Spatial | – | Enumerated | Mono | O | +| Max Number of Participants per node | Terminal | MRM allows more than 1 audio participant per node | 1-512 | Integer | 1 | O | +| Max Number of Audio channels per participant | Terminal | Support for stereo, or multi-channel audio | 1-8 | Integer | 1 | O | +| Max Number of Mixer ports required per conference | Network element | 1 channel connects to 1 port | 3-512 | Integer | 3 | O | +| Permissions to Control Mix | Network element | Flag | – | Boolean | FALSE | O | +| Start-Up Mode | Network element | Choice of Voice-switched or Manual | – | Enumerated | Automatic | O | +| Mixing Management Mode | – | Centralized
Distributed
Manual | – | Enumerated | Centrally | O | +| Number of separate mixer session (rooms) | – | The number of mixers determines how many separate rooms the conference can support | 1-127 | Integer | 1 | O | +| Floor Control | – | Flag | | Boolean | TRUE | O
O | + +**Audio Mode:** This parameter defines the audio mixing mode required.7 The parameter supports: + +- **Max Number of Audio channels per participant:** This parameter defines the maximum number of audio channels any individual participant may provide to the conference. +- **Max Number of Participants per node:** This Parameter defines the maximum number of participants that can be supported at an individual node. +- **Max Number of Mixer ports required per conference:** Each mixer port can accommodate a single mixer channel. This parameter gives the total number of ports available to the conference. + +**Start-up Mode:** Manual/Automatic. + +**Mixer Reporting flag:** Flag enables or disables Mixer status announcements, triggering roster updates. + +**Permissions to Control mix:** List of nodes/roles permitted to control the service. + +**Number of separate mixer sessions supported:** Number from 0 to *n*. + +NOTE – *n* should not exceed half the expected number of participants in the room and is typically less. + +**Floor Control:** A flag indicating if floor control is supported. + +7 The algorithms and mechanism required to mix in the supported modes are beyond the scope of this Recommendation. + +### 9.3.1 Description of abstract services + +- MRM-Launch – Used by the convening Node Controller at a Network Element to initialize its local MRM Provider and to indicate the intention to load a new framework should it become MRM Top Provider. +- MRM-Framework-Load – Used by the Conference Manager to load a new framework (provided by the convenor) at the MRM Top Provider. + +#### 9.3.1.1 MRM-Launch + +MRM-Launch is used by the node controller at the convening node to indicate to its MRM provider that it should initialize and if the "Compete for Top Provider role" flag is set, it should compete for the MRM top provider token. If it is successful in obtaining the MRM top provider token, it should then check the "New Framework Load Flag". If this is set to TRUE, it should wait for a new framework to be loaded before proceeding to act upon the framework requirements. + +Figure 3 shows the sequence of events when using this primitive. Table 5 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-Launch process between a Node Controller and a Network Element MRM Provider. The Node Controller sends an MRM-Launch request to the MRM Provider, and the MRM Provider sends an MRM-Launch confirm back to the Node Controller.](933ecd14c858bf3fc919222d8e357bc8_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant NE as Network Element MRM Provider + NC->>NE: MRM-Launch request + NE-->>NC: MRM-Launch confirm + +``` + +T1607370-99 + +Sequence diagram showing the MRM-Launch process between a Node Controller and a Network Element MRM Provider. The Node Controller sends an MRM-Launch request to the MRM Provider, and the MRM Provider sends an MRM-Launch confirm back to the Node Controller. + +**Figure 3/T.137 – MRM-Launch – Sequence of primitives** + +**Table 5/T.137 – MRM-Launch – Types of primitives and their parameters** + +| Content | Request | +|------------------------------------|---------| +| New Framework Load Flag | M | +| Compete for Top Provider Role Flag | M | + +**New Framework Load Flag:** When flag is set, this tells the MRM provider that if it takes on the role of MRM top provider it must wait for a new framework to be loaded before enrolling the MRM application. + +**Compete For Top Provider Role Flag:** If this flag is set, it tells the MRM provider it should compete for the MRM top provider role by trying to grab the MRM-Top Provider-Token. + +##### 9.3.1.2 MRM-Framework-Load + +*Protocol link: 10.6* + +The MRM protocol has a default framework configuration built into it, and an MRM-Framework-Load is not required in order to start an MRM conference. A new framework need only be loaded by the convenor when one or more of the default parameters needs to be changed. A new framework only needs to contain the actual parameters that are to be changed. Where a parameter is not supplied, the default will continue to be used. + +The MRM conference is created locally at the MRM top provider. If a new framework is to be loaded, it must be done immediately after conference creation and before any other nodes may join. The convenor may load a new framework by passing it to the conference manager (but this is a local matter). The conference manager is then responsible for generating an MRM-Framework-Load request, containing the new framework specification. The MRM top provider acknowledges receipt of a new framework by sending a confirm message to the conference manager. Once this has occurred, the top provider proceeds with the MRM conference establishment. + +On receipt of an MRM-Framework-Load request primitive the MRM provider shall check that it holds the MRM top provider token (MRM-Token-0) and that it has previously received an MRM-Launch-Indication asking it to wait for a new framework to be loaded. If these conditions are met, the MRM provider shall take the parameters contained in the new framework and use them to replace the default parameter values. If any of the parameters are out of range or incorrect, the result is locally set to "invalidParameters"; otherwise, the result is set to "successful". If the criteria are not met for receiving a new framework, the result will be set to "notAuthorized". The MRM provider generates an MRM-Load-Framework confirm primitive containing the result and sends it to the Control MRMSAP. The MRM Provider then has to act upon the framework requirement to initialize the MRM conference. The MRM top provider actions are specified in 10.4 (MRM initialization and start-up). + +MRM provides a second form of the MRM-Framework-Load function that allows the MRM top provider the ability to relay the framework on to other network elements, thus allowing them to shadow the top provider, or to cooperate in delivering the MRM conference. + +Figures 4 and 5 shows the sequence of events when using this primitive. Table 6 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-Framework-Load process between a Node Controller and a Top MRM Provider.](b904ac2472cab80892d1e783e6230d6e_img.jpg) + +``` +sequenceDiagram + participant NC as Node Controller + participant TMRP as Top MRM Provider + NC->>TMRP: MRM-Framework-Load request + TMRP-->>NC: MRM-Framework-Load confirm +``` + +The diagram illustrates the sequence of events for the MRM-Framework-Load primitive. It involves two entities: the Node Controller (represented by an oval) and the Top MRM Provider (represented by a vertical bar). The Node Controller sends an 'MRM-Framework-Load request' message to the Top MRM Provider. In response, the Top MRM Provider sends an 'MRM-Framework-Load confirm' message back to the Node Controller. The diagram is identified by the reference T1607380-99. + +Sequence diagram showing the MRM-Framework-Load process between a Node Controller and a Top MRM Provider. + +**Figure 4/T.137 – MRM-Framework-Load – Sequence of primitives** + +![Sequence diagram showing MRM-Topology-Load indication from MRM Top Provider to MRM Provider, and MRM-Topology-Load indication from MRM Provider to Node Controller.](7ae836e598020d937ed1478c2ef13025_img.jpg) + +``` + +sequenceDiagram + participant MRM_Top_Provider as MRM Top Provider + participant MRM_Provider as MRM Provider + participant Node_Controller as Node Controller + MRM_Top_Provider->>MRM_Provider: MRM-Topology-Load indication + MRM_Provider->>Node_Controller: MRM-Topology-Load indication + +``` + +Sequence diagram showing MRM-Topology-Load indication from MRM Top Provider to MRM Provider, and MRM-Topology-Load indication from MRM Provider to Node Controller. + +**Figure 5/T.137 – MRM-Topology-Load In band distribution to network elements – Sequence of primitives** + +**Table 6/T.137 – MRM-Topology-Load – Types of primitives and their parameters** + +| Content | Request | Indication | Confirm | +|----------------------------|---------|------------|---------| +| Request Handle | M | – | M(=) | +| New Default Framework Flag | M | M | | +| Originator Handle | O | O | – | +| Framework Handle | O | O | – | +| Conference Framework | M | M | | +| Result | | | M | + +**Request Handle:** Locally unique number to allow the request to be matched with the confirm. + +**New Default Framework Flag:** When this flag is set, the framework contained in the primitive should be used to replace the default framework. + +**Originator Handle:** This is the ID handle assigned to its creator by the service; this is an optional parameter that allows the creator to signal its identity. Predefinition of a conference framework occurs out of band and this parameter identifies that out-of-band entity to the service, unlike the MCS node ID of the convener which only identifies the entry point and may not allow resolution of who the out-of-band convener is. + +**Framework Handle:** This is the ID handle assigned to the framework by its creator; this is an optional parameter. + +**Conference Framework:** For parameters, see the framework specification in Table 4. + +**Result:** A response from the MRM top provider indicating whether the request was accepted or rejected, and, if rejected, the reason why. It contains one of the following of possible results: Successful, Not authorized, Invalid framework parameters. + +### 9.4 The MRM rosters + +The MRM roster mechanism is independent from the GCC roster. It is designed explicitly to support the needs of the MRM conference. The MRM roster consists of two parts: the MRM conference roster and the MRM room roster. The MRM conference roster holds information applicable to the whole conference while the room roster holds information about specific rooms. Both MRM rosters are held and maintained by the MRM top provider. The node controller associated with the top MRM provider has the role of MRM conference manager. As conference manager it can use the + +MRM-Roster-Enquire request primitive to obtain specified parameter updates from the MRM top provider. + +#### 9.4.1 Description of abstract services + +Following is a list and a summary for each of the primitives defined in this subclause: + +- MRM-Roster-Report – Used by the top provider to deliver a conference roster to a node entering a conference and a room roster to a node entering an MRM room. +- MRM-Roster-Update – Used by the conference manager to deliver an incremental roster update to all participants of a particular room or a conference. +- MRM-Roster-Enquire – Used by an MRM participant or observer to request specific information from the MRM roster. + +#### 9.4.1.1 MRM-Roster-Report primitives + +*Protocol link: 10.7.1* + +Normally, roster reports are initiated by the MRM top provider as a result of a node joining an MRM conference, entering an MRM room or in response to an enquiry. + +The default conference framework specifies what information should be included in a top provider initiated roster report, for a room report or for a conference report. If a new framework is used for a conference, the content of the reports can be modified and also be dependant on the level of participation of the recipient node. + +A roster report may also occur as a result of a roster enquiry. the enquiry is able to specify the desired content of the report. + +The conference manager may use the MRM-Roster-Report request primitive when it needs to initiate an unsolicited roster report; in such a situation all its parameters are conditionally required. This request primitive may be used to force a roster report when automatic reporting is disabled, or when providing only very limited information. This level of flexibility is primarily provided to support scalability; the recipients of the report are determined by the specified delivery channel or channels. Other nodes may request specific roster information using the MRM-Roster-Enquire mechanism. + +Figures 6 and 7 show the sequence of events when using this primitive. Table 7 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-Roster-Report primitive. The diagram involves three lifelines: MRM Top Provider, MRM Provider, and Requesting Node. A message labeled 'MRM-Roster-Report indication' is sent from the MRM Top Provider to the MRM Provider, and then from the MRM Provider to the Requesting Node. The Requesting Node is represented by an oval shape.](df6b7ae63e53e5f93dbd0a70acdae4a6_img.jpg) + +``` +sequenceDiagram + participant MRM_Top_Provider as MRM Top Provider + participant MRM_Provider as MRM Provider + participant Requesting_Node as Requesting Node + MRM_Top_Provider->>MRM_Provider: MRM-Roster-Report indication + MRM_Provider->>Requesting_Node: MRM-Roster-Report indication +``` + +Sequence diagram showing the MRM-Roster-Report primitive. The diagram involves three lifelines: MRM Top Provider, MRM Provider, and Requesting Node. A message labeled 'MRM-Roster-Report indication' is sent from the MRM Top Provider to the MRM Provider, and then from the MRM Provider to the Requesting Node. The Requesting Node is represented by an oval shape. + +**Figure 6/T.137 – MRM-Roster-Report: Automatic Reporting or in response to MRM-Roster-Enquire – Sequence of primitives** + +![Sequence diagram showing the MRM-Roster-Report process. A Node Controller sends an MRM-Roster-Report indication to the MRM Top Provider. The MRM Top Provider then sends an MRM-Roster-Report indication to the MRM Provider. Finally, the MRM Provider sends an MRM-Roster-Report indication to the Destination Node(s) dependent on the delivery channel. The diagram is labeled T1607410-99.](e451401f8fa77b466f401d5fce15b26c_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant MTP as MRM Top Provider + participant MP as MRM Provider + participant DN as Destination Node(s) +dependent on deliverychan + + NC->>MTP: MRM-Roster-Report indication + MTP->>MP: MRM-Roster-Report indication + MP->>DN: MRM-Roster-Report indication + +``` + +T1607410-99 + +Sequence diagram showing the MRM-Roster-Report process. A Node Controller sends an MRM-Roster-Report indication to the MRM Top Provider. The MRM Top Provider then sends an MRM-Roster-Report indication to the MRM Provider. Finally, the MRM Provider sends an MRM-Roster-Report indication to the Destination Node(s) dependent on the delivery channel. The diagram is labeled T1607410-99. + +**Figure 7/T.137 – MRM-Roster-Report: Conference Manager initiated – Sequence of primitives** + +**Table 7/T.137 – MRM-Roster-Report – Types of primitives and their parameters** + +| Content | Request | Indication | +|---------------------------------------------------|---------|------------| +| Channel ID List – determining Roster Recipient(s) | M | – | +| Use Defaults Flag | C | – | +| Scope of Report | C | – | +| Include Configuration Information – Flag | C | – | +| Include Status Information– Flag | C | – | +| Include Participants List – Flag | C | – | +| Include Participants Details – Flag | C | – | +| Include Rooms List – Flag | C | – | +| Include Information on other Rooms – Flag | C | – | +| Roster | – | M | + +**Channel ID:** Specifies which channel the report should be sent on. For a conference it would be the MRM-Conference-Communications-Channel, for a room it would be the Room ID, for a group it would be a Group channel ID, for an individual it would be the MRM User ID. This parameter may also include a list of User IDs. + +**Use Defaults Flag:** When this flag is set, the other flags are ignored and the conference framework determines which parameters are sent in the report. + +**Scope of Report:** This determines if report is a Conference Report, a Room report, a Group Report, or an Individual Report. + +**Include Configuration Information:** This flag tells the MRM Top provider to include configuration information. + +**Include Status Information:** This flag tells the MRM top provider to include status information. + +**Include Participants List:** This flag tells the MRM top provider to include a participant list. + +**Include Participants Details:** This flag tells the MRM top provider to include participants details. + +**Include Rooms List:** This flag tells the MRM top provider to include a room list. + +**Include Information on other Rooms:** This flag tells the MRM Top Provider to include information on all the other rooms in the conference roster report. + +**Roster Information:** The contents of a roster report PDU is determined by the default roster specification. The default Roster Parameter Set may be modified as a result of a Roster Enquire with + +the flag settings in a RosterEnquireIndication PDU, or by an MRM-Roster-Report request telling the MRM top provider what information to include. + +The MRM room roster may also include: + +###### **Room Roster Information: (All parameters are optional)** + +**Room Handle:** A conference-wide unique handle by which the room may be identified and accessed. + +**Roster Sequence Number:** A unique index number issued by MRM every time a new roster Report or Update is sent. + +###### **Conference Configuration Information** + +**ConfName:** Name of the conference. + +**ConfDescription:** Text string describing purpose of the conference. + +**ConfModel:** *Choice of conference modes – Unspecified, Formal meeting, Informal meeting, Multi-room conference, Broadcast conference, collaboration, gathering or user-defined. These parameters have no impact on protocol; they simply communicate an indication of requirements that may be interpreted locally.* + +**MaxConventionalNodes:** The maximum number of conventional nodes permitted in the conference. + +**MaxAnonymousNodes:** The maximum number of conventional nodes permitted in the conference. + +**PermittedServicesList:** List of MRM services permitted in conference. + +**PermittedRolesList:** List of MRM roles permitted in the conference. + +**GroupsPermittedFlag:** Flag indicated if groups are permitted in the conference. + +**MaxRooms:** The maximum number of room permitted in the conference. + +**NumRoomsDefined:** Number of rooms predefined for the conference. + +**ProhibitedPDUsList:** List of PDUs that will not be permitted for the conference. + +###### **Conference Status Information** + +**Number of Participants:** The number of participants currently in the conference. + +**Number of Observers:** The number of observers currently in the conference. + +**Number of Rooms:** The number of rooms currently defined within the conference. + +**Room Depth:** The current depth of rooms in the conference. + +**Room List:** List of all the defined rooms by Room ID. + +**Conference Participants list:** List of all the conference participants. + +###### **Room Configuration:** + +**Room ID:** A unique identifier for a specific room. + +**Room Framework ID:** The Framework ID which identifies a room constructor used to specify the room (when the room is predefined). + +**Room Mode:** The room determines scope and lifetime of the room. + +A permanent room is a room defined within the protocol, while a persistent room is dynamically created room, created and made persistent by the MRM top provider. A dynamic room only exists while the creator is joined to the room. A private room is owned by its creator and admission is only through invitation from the creator. + +**Room Management Model:** Parameter identifies a management model to support a given scenario. + +**Room Management Style:** Parameter indicates the level of formality required. + +**Room Type:** The room type is a usage classification; a number of types are defined within the Recommendation: lobby, meeting room, presentation room, gathering, personal room, team conference, panel conference. These types provide and communicate a classification of proposed use, but the precise interpretation is a local matter. + +**Room Media:** This parameter specifies which media the room is required to support. A set selected from the following: Audio, Video, Data, Realtime Data. + +**Room Access Model:** This parameter specifies if the room is to be open, or if access is to be controlled, or if the room is private and entry is to be via invitation only. + +**Room Entry Regime:** This specifies the procedure for entry to the room: either direct, via chair, via lobby or by invitation. + +**Room Exit Regime:** This specifies what happens when a node leaves a room: it may go back either to the previous room it was in or to the lobby, or it may exit the conference. + +**Room Hierarchy:** This parameter specifies where this room is in the hierarchy by identifying its parent. + +**Required Roles List:** A list of the roles required within this room. + +**Required Services List:** A list of the services required in this room and their current status. + +###### **Room Status** + +**Room State:** The current state of the room – choice of ready/active/suspended. + +**Number of participants:** Actual number of participants in the room. + +**Number of Observers:** Actual number of observers in the room. + +**Active Roles List:** List of roles active within the room. + +**Active Services List:** List of services active within the room. + +**Associated Application Protocol Sessions:** List of application protocol session associated with the room and only available to participants of that room. + +**Associated Groups List:** List of groups active within the room. + +**Room Participants list:** List of participants within the room. *Plus audio-only participants.* + +**Participants details:** Record of participant details (if available): User Handle, Name, Company, Address, email, Telephone No., Fax No. + +#### **9.4.1.2 MRM-Roster-Update primitives** + +An MRM-Roster-Update indication is sent by the top MRM provider. There are two cases where the MRM-Roster-Update mechanism is used. The PDU is issued in response to any event in the room that causes an update of a room roster parameter that was included in the original roster report. The roster update is broadcast to all nodes that have joined the room's communication channel. It contains only incremental changes from the last update or from the room report. The actual parameters sent will be based upon a default list of parameters specified in the protocol. This may only be overridden by using the framework mechanism. All updates and reports contain a sequence number, to ensure old information is never interpreted as being new, due to race condition between roster reports and roster updates. The MRM-Roster-Update indication is also used to provide conference roster updates on the conference communication channel. + +Figure 8 shows the sequence of events when using this primitive. Table 8 shows the parameters and types of this primitives. + +![Sequence diagram showing MRM Top Provider and MRM Provider lifelines. An arrow labeled 'MRM-Roster-Update indication' points from the MRM Provider lifeline to a participant labeled 'All node in Room' with ID 'T1607420-99'.](77959075c823bb5169480d7b8ff82a63_img.jpg) + +``` + +sequenceDiagram + participant MRM_Top_Provider as MRM Top Provider + participant MRM_Provider as MRM Provider + participant All_node_in_Room as All node in Room + MRM_Provider->>All_node_in_Room: MRM-Roster-Update indication + note over All_node_in_Room: T1607420-99 + +``` + +Sequence diagram showing MRM Top Provider and MRM Provider lifelines. An arrow labeled 'MRM-Roster-Update indication' points from the MRM Provider lifeline to a participant labeled 'All node in Room' with ID 'T1607420-99'. + +**Figure 8/T.137 – MRM-Roster-Update – Sequence of primitives** + +**Table 8/T.137 – MRM-Roster-Update – Types of primitives and their parameters** + +| Content | Indication | +|--------------------------------------|------------| +| Room Configuration Information | O | +| Room Status Information | O | +| Room Participants List | O | +| Conference Configuration Information | O | +| Conference Status Information | O | +| Participants List | O | +| Participant Details | O | + +**Room Configuration Information:** (see "Roster Report" above for parameter definitions) + +**Room Status Information:** (see "Roster Report" above for parameter definitions) + +**Room Participants List:** List of participants in the room. + +**Conference Configuration Information:** (see "Roster Report" above for parameter definitions) + +**Conference Status Information:** (see "Roster Report" above for parameter definitions) + +**Participants List:** List of participants in the conference. + +**Participants Details:** Record of participant details. + +#### 9.4.1.3 MRM-Roster-Enquire + +The MRM-Roster-Enquire is used by a node to request specific information about the room or conference from the MRM top provider. The Enquire will be answered with a roster report. + +Figure 9 shows the sequence of events when using this primitive. Table 9 shows the parameters and types of this primitives. + +![Sequence diagram showing the interaction between Node Controller, MRM Provider, and MRM Top Provider. The Node Controller sends an MRM-Roster-Enquire request to the MRM Provider. The MRM Provider then sends an MRM-Roster-Report indication back to the Node Controller. The MRM Top Provider is present but has no messages in this sequence. A reference T1607430-99 is noted at the bottom right.](5eb69662cc4fa7d0d49b4eb22951c204_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant MP as MRM Provider + participant MTP as MRM Top Provider + + NC->>MP: MRM-Roster-Enquire request + MP-->>NC: MRM-Roster-Report indication + MTP + +``` + +T1607430-99 + +Sequence diagram showing the interaction between Node Controller, MRM Provider, and MRM Top Provider. The Node Controller sends an MRM-Roster-Enquire request to the MRM Provider. The MRM Provider then sends an MRM-Roster-Report indication back to the Node Controller. The MRM Top Provider is present but has no messages in this sequence. A reference T1607430-99 is noted at the bottom right. + +**Figure 9/T.137 – MRM-Roster-Enquire – Sequence of primitives** + +**Table 9/T.137 – MRM-Roster-Enquire – Types of primitives and their parameters** + +| Content | Request | Confirm | +|----------------------------------------|---------|---------| +| Scope of Request | M | – | +| Detail Flag | M | – | +| Request Configuration Information Flag | M | – | +| Request Status Information Flag | M | – | +| Request Participants Information Flag | M | – | +| Request Participants List Flag | M | – | +| Request Room Templates Flag | M | – | + +**Scope of Request:** This allows the roster enquire to specify the whole conference, a specific room, a specific group, or an individual. + +**Detail Flag:** The MRM Rosters potentially contain a lot of information. The top provider will include information in its reports as specified in the framework. This flag allows the enquirer to request more details if they are available. + +**Request Configuration Information:** Flag is set when information is required on the configuration for the selected scope. + +**Request Status Information:** Flag is set when information is required on the status for the selected scope. + +**Request Participants Information:** Flag is set when participant information is required for the selected scope. + +**Request Participants List:** Flag is set if a list of MRM participants is required for the selected scope. + +**Request Room Templates:** Flag is set to request room template list from the top provider. + +**Result:** Successful, or contains the failure reason code "NotPermitted". + +### 9.5 Meeting rooms + +Meeting rooms may be predefined within a conference framework, using room constructor templates. When a framework containing a room specification is used to create a conference, the specified rooms will also be created. These rooms exist for the duration of the conference and are persistent meeting rooms. They will continue to exist even when the room is empty. Room persistence is achieved because the MRM top provider joins each of these rooms and remains there for the duration of the conference. + +Alternatively, only the room constructors can be predefined as part of a framework, and then later used by conference participants to create public or private rooms. + +Meeting rooms may also be created dynamically during the conference, in response to participant requirements. These dynamic rooms may be open, or have their access controlled. By default, dynamic rooms are owned by the creator and automatically terminated when the creator leaves. However, MRM allows the owner of the room to be specified, providing greater flexibility. + +In all cases, it is the MRM-Room-Create primitives that are used to create rooms. + +### 9.5.1 Description of abstract services + +Following is a list and a summary for each of the primitives defined in this subclause: + +- MRM-Room-Create – Used by a node controller to create a new MRM room. +- MRM-Room-Enter – Used by a node controller to enter an MRM room. +- MRM-Room-Leave – Used by a node controller to leave an MRM room. +- MRM-Room-Invite – Used by the creator of a private MRM room to invite the participation of another node. + +#### 9.5.1.1 MRM-Room-Create + +*Protocol link: 10.8.1* + +The MRM-Room-Create request primitive is used by a node controller to issue a request the creation of an MRM room, a separate meeting space within the existing conference. This room configuration may be fully specified or a room constructor template may be used, selected from a predefined framework definition. + +Figure 10 shows the sequence of events when using this primitive. Table 10 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-Room-Create process between Node Controller, MRM Provider, and MRM Top Provider.](f24f909d837b5476783e1bbea2dfc143_img.jpg) + +``` +sequenceDiagram + participant NC as Node Controller + participant MP as MRM Provider + participant MTP as MRM Top Provider + + NC->>MP: MRM-Room-Create request + MP->>MTP: + MTP-->>MP: + MP-->>NC: MRM-Room-Create confirm +``` + +The diagram illustrates the sequence of events for the MRM-Room-Create primitive. It involves three entities: Node Controller, MRM Provider, and MRM Top Provider. The Node Controller sends an 'MRM-Room-Create request' to the MRM Provider. The MRM Provider then sends a message to the MRM Top Provider, which returns a response to the MRM Provider. Finally, the MRM Provider sends an 'MRM-Room-Create confirm' message back to the Node Controller. A reference 'T1607440-99' is noted at the bottom right of the diagram. + +Sequence diagram showing the MRM-Room-Create process between Node Controller, MRM Provider, and MRM Top Provider. + +**Figure 10/T.137 – MRM-Room-Create – Sequence of primitives** + +**Table 10/T.137 – MRM-Room-Create – Types of primitives and their parameters** + +| Content | Request | Confirm | +|------------------------|---------|---------| +| Request Handle | M | M(=) | +| Room ID Handle | -- | C | +| Room Owner Flag | M | – | +| Room Parent | M | – | +| Framework Room ID | O | – | +| Use Template Flag | M | – | +| Room Template ID | O | – | +| Room Mode | O | – | +| Room Media | O | – | +| Room Access Regime | O | – | +| Room Entry Regime | O | – | +| Room Exit Regime | O | – | +| Room Name String | O | – | +| Room Purpose String | O | – | +| Number of Participants | O | – | +| Number of Observers | O | – | +| Required Roles List | O | – | +| Required Services List | O | – | +| Room Master Key | – | M | +| Result | – | M | + +**Request Handle:** Locally unique number to allow the requesting node to match responses. + +**Room ID Handle:** MRM Identifier for the room. An MCS channel ID. Supplied by the requesting MRM provider if it wishes to be the owner (this requirement is signalled to the provider by the node controller setting the ownership flag). In the absence of a Room ID being provided, the MRM top provider becomes the owner and provides a Room ID in the response. + +**Room Owner Flag:** Flag indicates if the requester wishes to own the room; if it is not set, then it is the MRM Top Provider that assumes ownership. + +**Room Parent:** Room ID handle for the parent room to which the new room should attach. + +**Framework Room ID:** This is a room identifier that has been pre-assigned to the room outside of the protocol through the framework mechanism. This parameter should therefore only be used by the Top MRM Provider in response to a framework being used to create a conference. + +**Use Template Flag:** Flag is set to TRUE if room specification is to be based upon framework constructor template. + +**Room Template ID:** Identifiers of a predefined template to be used to create the room; if supplied, the only other parameters that will be accepted are the numbers and strings. Other parameters should be left blank. + +**Room Mode:** Permanent, Persistent, Dynamic. + +**Room Media:** Audio/Video/other. + +**Room Access Regime:** Open, Controlled, Private. + +**Room Entry Regime:** Choice of: Direct, Chair mediated, By invitation, via lobby. + +**Room Exit Regime:** Return to: Previous/Lobby/Exit conference. + +**Room Hierarchy Support:** Integer between 1 and MaxTreeDepth. + +**Number of Participants:** Integer between 0 and max participants. + +**Number of Observers:** Integer between 0 and max participants. + +**Room Name String:** Optional name string for room. + +**Room Purpose String:** Optional room purpose description string. + +**Required Roles List:** Optional list of required roles. + +**Required Services List:** Optional list of required services. + +**Room Master Key:** Key returned by MRM top provider when a room is created; it will give holder access to this room irrespective of entry and access regimes in place. + +**Result:** Indicates whether the request was successful or if it failed one of the following reason codes: Not authorized, Prohibited by framework, Invalid template, Room depth exceeded, Max rooms exceeded, Invalid parent ID. + +#### 9.5.1.2 MRM-Room-Enter + +*Protocol link: 10.8.2* + +The MRM-Room-Enter request primitive is used by a node controller to move itself from a lobby or a meeting room into another MRM meeting room. A room may have an entry regime set-up that adds an extra stage to the room entry procedure. The node responsible for policing the entry regime is termed the "Door keeper" and is the arbiter of room entry requests. The "Door Keeper" role is by default assigned to the operator; however, it may be reassigned through the role mechanism. If the MRM-Room-Enter request fails, then the participant will remain in its current location. + +Figures 11 and 12 show the sequence of events when using this primitive. + +![Sequence diagram for MRM-Room-Enter showing interactions between Node Controller, MRM Provider, MRM Top Provider, and Conference Manager Node Controller.](71a22f206329906db6e3860c7ff8c796_img.jpg) + +``` +sequenceDiagram + participant NC as Node Controller + participant MP as MRM Provider + participant MTP as MRM Top Provider + participant CMNC as Conference Manager Node Controller + + NC->>MP: MRM-Room-Enter request + MP->>MTP: + MTP->>CMNC: MRM-Room-Enter indication + CMNC->>MTP: + MTP->>MP: MRM-Room-Enter response + MP->>NC: MRM-Room-Enter confirm +``` + +The diagram illustrates the sequence of events for the MRM-Room-Enter primitive. It involves four entities: Node Controller, MRM Provider, MRM Top Provider, and Conference Manager Node Controller. The sequence is as follows: 1. The Node Controller sends an 'MRM-Room-Enter request' to the MRM Provider. 2. The MRM Provider sends an empty message to the MRM Top Provider. 3. The MRM Top Provider sends an 'MRM-Room-Enter indication' to the Conference Manager Node Controller. 4. The Conference Manager Node Controller sends an empty message back to the MRM Top Provider. 5. The MRM Top Provider sends an 'MRM-Room-Enter response' to the MRM Provider. 6. The MRM Provider sends an 'MRM-Room-Enter confirm' to the Node Controller. A reference 'T1607450-99' is noted at the bottom right of the diagram. + +Sequence diagram for MRM-Room-Enter showing interactions between Node Controller, MRM Provider, MRM Top Provider, and Conference Manager Node Controller. + +**Figure 11/T.137 – MRM-Room-Enter – Sequence of primitives** + +![Sequence diagram for Figure 12/T.137 showing the MRM-Room-Enter process. The diagram involves three lifelines: MRM Provider, MRM Top Provider, and Conference Manager Node Controller. The MRM Top Provider sends an 'MRM-Room-Enter indication' to the Conference Manager Node Controller. The Conference Manager Node Controller then sends an 'MRM-Room-Enter response' back to the MRM Top Provider. The MRM Provider is present but has no messages in this sequence.](cbb2d311b20781a595488445ded48d0a_img.jpg) + +``` + +sequenceDiagram + participant MRMProvider as MRM Provider + participant MRMTOP as MRM Top Provider + participant CMNC as Conference Manager Node Controller + + MRMTOP->>CMNC: MRM-Room-Enter indication + CMNC-->>MRMTOP: MRM-Room-Enter response + +``` + +T1607460-99 + +Sequence diagram for Figure 12/T.137 showing the MRM-Room-Enter process. The diagram involves three lifelines: MRM Provider, MRM Top Provider, and Conference Manager Node Controller. The MRM Top Provider sends an 'MRM-Room-Enter indication' to the Conference Manager Node Controller. The Conference Manager Node Controller then sends an 'MRM-Room-Enter response' back to the MRM Top Provider. The MRM Provider is present but has no messages in this sequence. + +**Figure 12/T.137 – MRM-Room-Enter: In response to MRM Top Provider command – Sequence of primitives** + +Where a role holder such as the chair is required to authorize room access, there is an additional protocol step required to get permission from the arbiter to enter the room. Once the arbiter's permission is obtained, the room entry procedure continues in the normal way. (See Figure 13.) + +![Sequence diagram for Figure 13/T.137 showing the MRM-Room-Enter process with an arbiter. The diagram involves five lifelines: Node Controller, MRM Provider, MRM Top Provider, Authorizing Node, and Conference Manager. The Node Controller sends an 'MRM-Room-Enter request' to the MRM Provider. The MRM Top Provider sends a 'PermissionAsk' to the Authorizing Node. The Authorizing Node sends an 'MRM-Permission-Ask response' back to the MRM Top Provider. The MRM Top Provider then sends an 'MRM-Room-Enter indication' to the Conference Manager. The Conference Manager sends an 'MRM-Room-Enter response' back to the MRM Top Provider. Finally, the MRM Provider sends an 'MRM-Room-Enter confirm' to the Node Controller.](32ff77da4286b58c4778033acaa10836_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant MRMP as MRM Provider + participant MRMTOP as MRM Top Provider + participant AN as Authorizing Node + participant CM as Conference Manager + + NC->>MRMP: MRM-Room-Enter request + MRMTOP->>AN: PermissionAsk + AN-->>MRMTOP: MRM-Permission-Ask response + MRMTOP->>CM: MRM-Room-Enter indication + CM-->>MRMTOP: MRM-Room-Enter response + MRMP-->>NC: MRM-Room-Enter confirm + +``` + +T1607470-99 + +Sequence diagram for Figure 13/T.137 showing the MRM-Room-Enter process with an arbiter. The diagram involves five lifelines: Node Controller, MRM Provider, MRM Top Provider, Authorizing Node, and Conference Manager. The Node Controller sends an 'MRM-Room-Enter request' to the MRM Provider. The MRM Top Provider sends a 'PermissionAsk' to the Authorizing Node. The Authorizing Node sends an 'MRM-Permission-Ask response' back to the MRM Top Provider. The MRM Top Provider then sends an 'MRM-Room-Enter indication' to the Conference Manager. The Conference Manager sends an 'MRM-Room-Enter response' back to the MRM Top Provider. Finally, the MRM Provider sends an 'MRM-Room-Enter confirm' to the Node Controller. + +**Figure 13/T.137 – MRM-Room-Enter: With an arbiter to authorize entry – Additional sequence of primitives** + +Table 11 shows the parameters and types of this primitive. + +**Table 11/T.137 – MRM-Room-Enter – Types of primitives and their parameters** + +| Content | Request | Indication | Response | Confirm | +|---------------------------|---------|------------|----------|---------| +| Request Handle | M | – | – | M(=) | +| Requesting Node ID | | C | | | +| Enter Room ID | M | M(=) | M | M(=) | +| Current Room ID | M | M(=) | | | +| Type of Participation | C | C(=) | | | +| Terminate/Suspend Flag | M | M(=) | | | +| Goto Room ID | – | – | – | O | +| Channel to Join | – | – | – | O | +| Room Access Parameter | C | C(=) | | | +| Role Access Parameter Key | C | C(=) | | | +| Reason for Entry | O | O(=) | O | O(=) | +| Result | | M | C | M | + +**Request Handle:** Locally unique number to allow the requesting node to match responses. + +**Requesting Node ID:** Required when there is an arbiter for room enter requests. + +**Enter Room ID:** Room to be entered. + +**Current Room ID:** Room ID for current location of node. + +**Type of Participation:** If a Room ID is specified, the node entering the room may indicate if it wishes to participate as an observer or as a participant. In the absence of this parameter, this is determined automatically, based upon the node's participation in GCC, as a conventional node, or as an anonymous node. If provided, this parameter will be verified, and nodes that are anonymous will not be allowed to take part as MRM participants within a room. + +**Terminate/Suspend Flag:** This flag tells the protocol if the user is temporarily leaving the previous room and wishes to maintain state and data applications for a later return. + +**Goto Room ID:** When the result parameter tells the requesting node to go to another room, e.g. the reception room, this parameter contains the Room ID for the nominated room. + +**Channel to Join:** Provided by the top provider to tell the entrant which channel to join, used in the case where the entrant provides a key instead of an Enter Room ID. + +**Room Access Parameter:** For controlled access rooms, an entry key is needed. When this is provided inband, it is contained in this parameter: *Password*. + +**Role Access Parameter Key:** Key provided out of band that will allow node to be automatically assigned a role. + +**Reason for Entry:** Optional text string which will be added to the room roster database. + +**Result:** Indicates whether the request was successful. It contains one of the following results: Successful, Private room, Goto specified room, Invalid room ID, Not authorized. + +#### 9.5.1.3 MRM-Room-Invite + +Protocol link: 10.8.3 + +The MRM-Room-Invite request primitive enables the creator of a private room to invite nodes to participate in that room. Such nodes may then join the designated room by using the MRM-Room-Enter primitive. + +Figure 14 shows the sequence of events when using this primitive. Table 12 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-Room-Invite process. A Node Controller sends an MRM-Room-Invite request to an MRM Provider. The MRM Provider then sends an MRM-Room-Invite indication to a Destination Node Controller. Finally, the MRM Provider sends an MRM-Room-Invite confirm back to the original Node Controller.](a161a2bbb4d830e847ccb4f44b7e41a9_img.jpg) + +``` + +sequenceDiagram + participant NC1 as Node Controller + participant MP1 as MRM Provider + participant MP2 as MRM Provider + participant DNC as Destination Nodes Node Controller + + NC1->>MP1: MRM-Room-Invite request + MP1->>MP2: + MP2->>DNC: MRM-Room-Invite indication + MP2-->>NC1: MRM-Room-Invite confirm + +``` + +T1607480-99 + +Sequence diagram showing the MRM-Room-Invite process. A Node Controller sends an MRM-Room-Invite request to an MRM Provider. The MRM Provider then sends an MRM-Room-Invite indication to a Destination Node Controller. Finally, the MRM Provider sends an MRM-Room-Invite confirm back to the original Node Controller. + +**Figure 14/T.137 – MRM-Room-Invite – Sequence of primitives** + +**Table 12/T.137 – MRM-Room-Invite – Types of primitives and their parameters** + +| Content | Request | Indication | Confirm | +|-------------------|---------|------------|---------| +| Request Handle | M | – | M(=) | +| Room ID | M | M(=) | | +| Room Entry Key | M | M | | +| Invited Node List | M | – | | +| Invitor's MRM ID | – | M | | +| Reason String | O | O(=) | | +| Result | | O(=) | M | + +**Request Handle:** Locally unique number to allow the requesting node to match responses. + +**Room ID:** The MRM room to which nodes are being invited. + +NOTE – RoomID = **MRM-Room-Communication-Channel**. + +**Room Entry Key:** Password or other form of access key needed to enter the room. + +**Invited Node List:** List of MRM User IDs to be invited. + +**Inviter's MRM ID:** MRM User ID of the node which initiated the MRM-Session-Invite request. + +**Reason String:** This parameter can be used to provide a human-readable string with reason for invitation in the request. + +**Result:** Successful, Invalid Room ID, Not room owner. + +### 9.6 MRM groups + +An MRM group is an association of nodes participating *within* an MRM room. This association can be used to allow the group members to be treated as a single entity for the purpose of control or indications, for example allowing all group members to be muted or mixed. Group membership is a type of room role that room participants can take on or be assigned. MRM allows groups to be pre-assigned by means of the conference framework and it also allows groups to be defined by the convenor, or by authorized participants when the room is active. Further to this, MRM supports the advertising of groups, allowing them to be joined by participants. A group may have an owner defined. By default this will be the creator; however, it may be assigned to another node. + +### 9.6.1 Specifying groups in the framework + +If the conference convenor wishes to pre-define groups for use within a conference, then this must be done as part of the conference framework. Usually, group definitions are done within the context of a specific room. However, the group scope flag may be set to conference instead of room, allowing a group to have membership across the entire MRM conference. + +Room and group requirements are realized when a framework is loaded into a created conference. Like rooms, MRM groups are assigned a unique identifier that also provides a communication channel for that group. When a group is specified in the conference framework, it is assigned a key, that is the means by which nodes can enter and be added to the group automatically. Nodes with pre-assigned roles or groups will only be able to identify or specify the group by its framework identifier. So, once the conference is started, this identifier must be associated by the protocol with the assigned MRM identifier for the group. + +The convenor may pre-define a group by assigning it a Framework Group ID; the convenor may optionally specify a group name and purpose that are both human-readable strings, providing a means for participants to identify the group. If the convenor wishes to define an ordering of group members, for example to provide an order of presenters, then an access key must be specified for each member. Each key must be unique and the order of specification will represent the order within the group. + +### 9.6.2 Specifying groups within an active room + +If the convenor or an authorized participant wishes to define a group in an active room, then the MRM-Group-Create request primitive is used. When a group is created, an MCS channel is assigned to the group and used as the identifier and communication channel for that group. The group may, if required, have a human-readable name and/or a purpose description assigned to it. Any names and description are made available to participants as appropriate through the MRM roster mechanism. Group participation may be expressed as a list of MRM User IDs taken from the room roster and/or an access key which will be used to validate nodes requesting to join. Group information is always public but the ability to join a group may be dependent on having a valid access key. A group member leaving a room will also be removed from a group if the group's scope is limited to just that room. + +### 9.6.3 Description of abstract services + +Following is a list and a summary for each of the primitives defined in this subclause: + +- MRM-Group-Create – Used by a node controller to associate one or more nodes within an MRM conference for the purpose of control and management. +- MRM-Group-Disband – Used to remove an existing group definition. +- MRM-Group-Membership-Specify – Used to specify which nodes shall become part of the MRM group. + +#### 9.6.3.1 Creating a group + +Figure 15 shows the sequence of events when using this primitive. Table 13 shows the parameters and types of this primitives. + +*Protocol link: 10.8.4* + +![Sequence diagram for MRM-Group-Create showing interactions between Node Controller, MRM Provider, MRM Top Provider, and All nodes in scope of group.](a003ffe7299e0a48bceb7f1e45a4f1a3_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant MP1 as MRM Provider + participant MTP as MRM Top Provider + participant MP2 as MRM Provider + participant ANSG as All nodes in scope of group + + NC->>MP1: MRM-Group-Create request + MP1->>MTP: + MTP->>MP2: + MP2->>ANSG: MRM-Roster-Update indication + MP1-->>NC: MRM-Group-Create confirm + +``` + +The diagram illustrates the sequence of events for creating a group. It involves five entities: Node Controller, MRM Provider, MRM Top Provider, MRM Provider, and All nodes in scope of group. The sequence is as follows: 1. Node Controller sends an MRM-Group-Create request to the first MRM Provider. 2. The first MRM Provider sends a message to the MRM Top Provider. 3. The MRM Top Provider sends a message to the second MRM Provider. 4. The second MRM Provider sends an MRM-Roster-Update indication to all nodes in scope of the group. 5. The first MRM Provider sends an MRM-Group-Create confirm message back to the Node Controller. The diagram is labeled T1607490-99. + +Sequence diagram for MRM-Group-Create showing interactions between Node Controller, MRM Provider, MRM Top Provider, and All nodes in scope of group. + +**Figure 15/T.137 – MRM-Group-Create – Sequence of primitives** + +**Table 13/T.137 – MRM-Group-Create – Types of primitives and their parameters** + +| Content | Request | Confirm | +|---------------------------|---------|---------| +| Request Handle | M | M(=) | +| Group Owner's MRM User ID | O | – | +| Group Scope Flag | M | – | +| Room ID Handle | C | – | +| Group ID | – | M | +| Group Name | O | – | +| Group Function | O | – | +| Ordered Group Flag | M | – | +| Group Member List | O | – | +| Result | – | M | + +**Request Handle:** Locally unique number to allow the requesting node to match responses. + +**Group Owner's MRM User ID:** The creator of the group specifies which node will own the group. + +**Group Scope Flag:** Flag specifies the scope of the group. + +NOTE – This will normally be a room. Setting the flag to TRUE makes the scope conference wide. + +**Room ID Handle:** The Room Identification Handle which the group is to be associated with. + +**Group ID:** The Group ID is assigned by the top MRM provider and is guaranteed unique within that conference. + +**Group Name:** Optional name string for the group. + +**Group Function:** Optional description string for the group. + +**Ordered Group Flag:** Flag specifies that the group is to be an ordered group. + +**Group Member List:** Optional list of group participants. + +**Result:** Result of the Group-Create request. + +#### 9.6.3.2 Disbanding a group + +Figure 16 shows the sequence of events when using this primitive. Table 14 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-Group-Disband process. A Node Controller sends an MRM-Group-Disband request to an MRM Provider. The MRM Provider sends an MRM-Group-Disband confirm back to the Node Controller. The MRM Provider also sends an MRM-Roster-Update indication to an MRM Top Provider, which then sends an MRM-Roster-Update indication to another MRM Provider, which finally sends an MRM-Roster-Update indication to a Node Controller.](0f1767577a073167eb9628d72034e083_img.jpg) + +``` +sequenceDiagram + participant NC as Node Controller + participant MP1 as MRM Provider + participant MTP as MRM Top Provider + participant MP2 as MRM Provider + participant NC2 as Node Controller + + NC->>MP1: MRM-Group-Disband request + MP1-->>NC: MRM-Group-Disband confirm + MP1->>MTP: MRM-Roster-Update indication + MTP->>MP2: MRM-Roster-Update indication + MP2->>NC2: MRM-Roster-Update indication +``` + +Sequence diagram showing the MRM-Group-Disband process. A Node Controller sends an MRM-Group-Disband request to an MRM Provider. The MRM Provider sends an MRM-Group-Disband confirm back to the Node Controller. The MRM Provider also sends an MRM-Roster-Update indication to an MRM Top Provider, which then sends an MRM-Roster-Update indication to another MRM Provider, which finally sends an MRM-Roster-Update indication to a Node Controller. + +**Figure 16/T.137 – MRM-Group-Disband – Sequence of primitives** + +**Table 14/T.137 – MRM-Group-Disband – Types of primitives and their parameters** + +| Content | Request | Confirm | +|-----------------|---------|---------| +| Request Handle | M | M(=) | +| Group ID Handle | M | M(=) | +| Result | – | M | + +**Request Handle:** Locally unique number to allow the requesting node to match responses. + +**Group ID Handle:** MRM User ID for the group. + +**Result:** Result of disband request returned by top provider – Successful, Not group owner, Invalid group ID. + +#### 9.6.3.3 Assigning group membership + +Figure 17 shows the sequence of events when using this primitive. Table 15 shows the parameters and types of this primitives. + +*Protocol link: 10.8.4* + +![Sequence diagram showing the MRM-Group-Membership-Specify process. The diagram involves five participants: Node Controller, MRM Provider, MRM Top Provider, MRM Provider, and All nodes in scope of group. The sequence of events is: 1. Node Controller sends 'MRM-Group-Membership-Specify request' to the first MRM Provider. 2. The first MRM Provider sends a message to the MRM Top Provider. 3. The MRM Top Provider sends a message to the second MRM Provider. 4. The second MRM Provider sends 'MRM-Roster-Update indication' to 'All nodes in scope of group'. 5. The first MRM Provider sends 'MRM-Group-Membership-Specify confirm' back to the Node Controller. A reference 'T1607510-99' is noted at the bottom right.](3442f31a562d1ef45bfa18b18a6a1ddc_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant MP1 as MRM Provider + participant MTP as MRM Top Provider + participant MP2 as MRM Provider + participant ANSG as All nodes in scope of group + + NC->>MP1: MRM-Group-Membership-Specify request + MP1->>MTP: + MTP->>MP2: + MP2->>ANSG: MRM-Roster-Update indication + MP1-->>NC: MRM-Group-Membership-Specify confirm + +``` + +T1607510-99 + +Sequence diagram showing the MRM-Group-Membership-Specify process. The diagram involves five participants: Node Controller, MRM Provider, MRM Top Provider, MRM Provider, and All nodes in scope of group. The sequence of events is: 1. Node Controller sends 'MRM-Group-Membership-Specify request' to the first MRM Provider. 2. The first MRM Provider sends a message to the MRM Top Provider. 3. The MRM Top Provider sends a message to the second MRM Provider. 4. The second MRM Provider sends 'MRM-Roster-Update indication' to 'All nodes in scope of group'. 5. The first MRM Provider sends 'MRM-Group-Membership-Specify confirm' back to the Node Controller. A reference 'T1607510-99' is noted at the bottom right. + +**Figure 17/T.137 – MRM-Group-Membership-Specify – Sequence of primitives** + +**Table 15/T.137 – MRM-Group-Membership-Specify – Types of primitives and their parameters** + +| Content | Request | Confirm | +|------------------------------|---------|---------| +| Request Handle | M | M(=) | +| Group Identifier | M | – | +| Add Member List | O | – | +| Remove Member List | O | – | +| Specify Complete Member List | O | – | +| Result | – | M | + +**Request Handle:** Locally unique number to allow the requesting node to match responses. + +**Group Identifier:** User ID obtained by top provider and used to represent group. + +**Add Member List:** List of MRM User IDs from the room or conference roster. + +**Remove Member List:** List of MRM User IDs from the room or conference roster to be removed from group. + +**Specify Complete Member List:** Complete group membership list of MRM User IDs from the room or conference roster. + +**Result:** Result of group membership specification request. Either Success, or List contain successful assignments, or Not authorized to add to group. + +#### 9.6.3.4 Group leader + +When a group has been defined, it is possible to use the role primitives to define a group leader who can act as spokesperson or arbiter for the group. This is done by specifying a group identifier in the MRM-Room-Role-Assign request. This role only has privileges over members of the same group. A group leader cannot be compared with other roles, which have jurisdiction across the whole room. + +When the room in which the group is defined has a chair, the group leader sits between the other group members and the chair and can arbitrate between competing requests to speak, to be seen, or to use the data applications. + +### 9.7 T.120 sessions + +MRM provides the potential to segregate a GCC conference into a number of MRM rooms. To fully realize the potential of the MRM model, T.120 application sessions should have the ability to have their scope limited to only the participants within a particular MRM room. MRM provides the session association mechanism to allow data application sessions to be associated with an MRM room, thus signalling the requirement for a reduced scope for that data session. + +### 9.7.1 Description of abstract services + +- MRM-Session-Associate – The means to indicate a data application session is to be associated with an MRM room. + +#### 9.7.1.1 MRM-Session-Associate + +*Protocol Link: 10.9* + +The MRM-Session-Associate request primitive is used by a node controller to associate an MRM session with one or more data sessions. A successful request supersedes any previous associations for a particular data application. The primitive may thus also be used to terminate associations. By default, all data sessions are implicitly associated with the MRM Terminal Standard Default Room. Nodes can determine which data sessions are associated with a particular MRM room from the MRM room roster for that room. The data sessions are referenced using their registry key as defined in Recommendation ITU-T T.120. + +Figure 18 shows the sequence of events when using this primitive. Table 16 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-Session-Associate interaction between an MRM User and an MRM Provider. The MRM User sends an 'MRM-Session-Associate request' to the MRM Provider, and the MRM Provider returns an 'MRM-Session-Associate confirm' to the MRM User.](2aa94b70ba3fadcba8420d9e3128253a_img.jpg) + +``` + +sequenceDiagram + participant User as MRM User + participant Provider as MRM Provider + User->>Provider: MRM-Session-Associate request + Provider-->>User: MRM-Session-Associate confirm + +``` + +T1607520-99 + +Sequence diagram showing the MRM-Session-Associate interaction between an MRM User and an MRM Provider. The MRM User sends an 'MRM-Session-Associate request' to the MRM Provider, and the MRM Provider returns an 'MRM-Session-Associate confirm' to the MRM User. + +**Figure 18/T.137 – MRM-Session-Associate – Sequence of primitives** + +**Table 16/T.137 – MRM-Session-Associate – Types of primitives and their parameters** + +| Content | Request | Confirm | +|---------------------|---------|---------| +| Request Handle | M | M(=) | +| Room ID | M | – | +| Associated Sessions | M | | +| Result | | M | + +**Request Handle:** Locally unique number to allow the requesting node to match responses. + +**Room ID:** The Room ID for the MRM room to which the following application protocol sessions are to be associated. + +**Associated Sessions:** A list of application keys and Session IDs of data application protocol sessions with which the specified MRM session is to be associated. + +**Result:** Indicates whether the request was successful. It contains one of the following results: Successful, Invalid session ID, Not authorized node. + +### 9.8 MRM room roles + +An MRM conference supports participation of both conventional nodes and anonymous nodes. In the MRM protocol these node types define the level of participation in the MRM conference and are effectively conference roles. The anonymous role is used by a node joining the MRM conference as an observer, while the conventional role is used by a fully functional participant in the conference. Only conventional nodes are permitted to take on additional conference or room roles. + +MRM provides support for a convenor role, which is effectively a default administration role allowing extensive access to creation and management tools. Users are free if they wish to define their own administrator roles by assigning the required role attributes to a new role definition. MRM also provides support for a standardized room chair role. This provides a capability for management of the proceedings within a room. + +The chair role for the default room may be aligned with the GCC conductor role (defined in Recommendation T.124) but unlike the GCC roles which are conference wide, these roles are only valid within the context of an MRM room. The MRM convenor role can be regarded as an extension of the GCC convenor's capabilities to support the requirements of MRM. The GCC/MRM convenor is assigned at conference creation time and is not a role that may be taken on within the conference. + +The chair and the user-defined roles utilize the MRM-Room-Role primitives, by using the role field to specify which role is being addressed. Non-standard identifiers are used to identify user-defined roles. + +The MRM conference framework is typically used to put bounds upon resource requirements for the conference. It can also be used to impose a required usage model and management regime. For events where role holders are known in advance, the framework will not only allow the specific role to be pre-defined within a room, but also allow access keys to be associated with given roles. These keys are passed out of band to the defined role-holder. When a participant with a pre-defined role and an access key enters a room and makes a role assignment request, the request is validated by the MRM top provider against the framework and the role is assigned if the key is valid. + +The pre-assignment of roles and access keys using the framework allows the establishment of potentially complex conference scenarios to be automated and minimizes the complexity for the participant. + +The node controller at each node will receive room role indications. If the "Synchronize Data conference" flag is set, then the Node Controller should also pass these indications on to any data application protocol sessions that are associated with that room. + +MRM defines two standard roles; part of the value of these roles is that they provide a standardized behaviour for functionality that is regularly required. Table 17 shows the function attributes assigned to the standardized room roles. From the table a user-defined role can be created and function attributes assigned to it. + +**Table 17/T.137 – Room permission privileges – Parameters for standardized room roles and to facilitate room role creation** + +| Roles
Function permissions
(when role active) | Convenor | Observer | Participants | | | +|-----------------------------------------------------|----------|----------|-------------------|-------------------------|--------------------------| +| | | | Basic permissions | Added Chair permissions | User-defined permissions | +| Role permissions | | | | | | +| Create Role | √ | x | x | √ | O | +| Pass Role | √ | x | O | √ | O | +| Ask For Role | √ | x | O | √ | O | +| Modify Role Permissions | √ | x | x | x | O | +| Modify Other Role Permissions | √ | x | x | x | O | +| Chair Authorizes Role request | √ | x | C | x | O | +| Room management | | | | | | +| Create/Modify/Destroy child rooms | √ | x | O | √ | O | +| Child Rooms Inherit Parent Roles | √ | x | O | √ | O | +| Authorize Room Entry (Door Keeper) | √ | x | x | √ | O | +| Modify Room Parameters | √ | x | x | √ | O | +| Create/Modify/Destroy groups | √ | x | O | √ | O | +| Change Group Ordering | √ | x | x | √ | O | +| Start/Stop floor Control | √ | x | x | √ | O | +| Authorize Room transactions | – | – | – | O | O | +| Request Floor | – | O | O | – | O | +| Operate Floor Control | √ | x | x | √ | O | +| Invite Participants | √ | x | O | √ | O | +| Eject participants from Conference | √ | x | O | √ | O | +| Data application control | | | | | | +| View Data Apps | O | O | O | √ | O | +| Control Data Apps | O | x | x | √ | O | +| Exclusive Control of Data App(s) | O | x | x | O | O | +| Launch Data Applications | O | O | O | √ | O | +| View Specific Application | O | O | O | √ | O | +| Control Specific Application | O | x | O | √ | O | +| Control Specific Device | O | x | O | √ | O | +| Service management | | | | | | +| Launch Media Services | C | x | x | √ | O | +| Activate Media Services | C | x | x | √ | O | +| Audio | | | | | | +| Control Audio Mixes | O | x | x | √ | O | +| Control Audio Devices | O | x | x | √ | O | +| Invite audio Only participants | O | x | O | √ | O | +| Mutable By others | x | √ | √ | x | O | + +**Table 17/T.137 – Room permission privileges – Parameters for standardized room roles and to facilitate room role creation (*concluded*)** + +| Roles
Function permissions
(when role active) | Convenor | Observer | Participants | | | +|-----------------------------------------------------------|----------|----------|-------------------|-------------------------|--------------------------| +| | | | Basic permissions | Added Chair permissions | User-defined permissions | +| Video | | | | | | +| Control Video Devices | O | x | O | √ | O | +| View Video | O | O | O | √ | O | +| C Conditional
O Optional
√ Required
x Prohibited | | | | | | + +Table 17 shows MRM functionality classified as a number of separate permissions. It shows that the static conference role of convenor has, as conference creator, many default privileges to reconfigure and change role permissions. It also shows that an observer is prohibited from using most of the functionality available to MRM participants. MRM participants have a range of permissions available and some features restricted. The table also shows the chair, the only MRM room role defined in the protocol, and the permissions associated with that role. The final column shows that user-defined roles may be assigned with any combination of permissions as required. + +### 9.8.1 Room role permissions – Specification + +This Meeting Room Management Recommendation supports standard and user-defined specification of room-based Roles. Every role definition is effectively a unique identification label for a group of permissions and privileges to access or control additional functionality. When a room role is assigned to a room, it only has scope within that room; this is based upon the premise that a participant can only be in one room at any given time. + +The role permissions list is divided into five categories: Role permissions, Room management, Data Application Management, Video Management and control, and Audio Management and control. Every person participating in an MRM conference adopts either the role of an observer or that of a participant, and these two roles are an inherent part of the MRM operational model. Effectively, everyone in an MRM conference is therefore a role holder; additional roles may be taken on or assigned using the MRM role functionality. These additional roles effectively modify the privilege list for that node. The MRM roster contains information on roles held and roles assigned. + +**Create/Modify Role** – This permission provides the ability for the role holder to create additional roles, and arbitrarily assign privileges to those roles. It is the task of the MRM top provider to prohibit assignment of privileges the creator is not authorized to use. In most cases it is expected that roles will be pre-defined within the conference framework. + +**Pass Role** – This permission allows the role holder permission to use MRM-Room-Role-Give functionality, allowing a role holder to give the role to another conventional node in the MRM meeting room. + +**Ask For Role** – This permission allows the role holder permission to use MRM-Room-Role-Please functionality, allowing a role holder to request a role from another conventional node in the MRM meeting room. + +**Modify Other Role Holder Permissions** – This permission allows a role holder to modify other role permissions at will. The MRM conference manager should also prohibit arbitrary use of this as appropriate for the operational use of the protocol. + +**Modify Role Holder Permitted Privileges** – This permission allows a role holder to modify other role permissions only if it has that permission itself. This is the safest option to use as it does not allow dynamic enhancement of permissions within a conference. + +**Chair Authorizes Role request** – This permission determines if the chair needs to authorize role assignment requests when a chair is assigned. + +#### **Room Management** + +**Create child rooms** – This permission allows the role holder to use the MRM room functions to create additional meeting rooms. + +**Make Rooms Persistent** – This permission allows a role holder the capability to make an existing dynamic room persistent, but not the creation, modification, or destruction of rooms. + +**Create/Modify/Disband groups** – This permission allows the role holder to use the MRM group functions to create, modify, and disband groups. + +**Modify Room Parameters** – This permission allows the holder to modify parameters within a room. + +**Change Group Ordering** – This permission allows an ordered group's ordering to be modified. + +**Start/Stop Floor Control** – This privilege allows the role holder permission to access the floor control service. + +**Authorize Room Transactions** – This privilege causes all transactions such as role assignments to require authorization from the holder of the privilege before proceeding. The MRM top provider generates Permission-Ask requests to obtain permission on the nodes' behalf. MRM ensures only one authorizing node can exist in any given room. + +**Request Floor** – This permission allows the role holder to have access to the request to participate functions. + +**Operate Floor Control** – This privilege allows the role holder permission to manage the floor control service. + +**Invite Participants** – This permission allows the role holder the ability to invite participants to a room. + +**Eject Participants** – Eject participants from the conference using the GCC Eject User mechanism. + +#### **Data application management** + +**View Data Apps** – This permission allows the role holder the ability to view data applications, although this is available by default for participants. The removal of this feature allows, for example, an operator to come in and assist in the conference without being able to view the data content. + +**Manage Data Apps** – This permission allows the role holder the ability to manage data application. For most applications this may just consist of access to the controls to drive the application. MRM-aware applications may provide additional management support for management. + +**Exclusive Management of Data Apps** – This permission allows this role holder and only this role holder access to the ability to manage data applications. + +**Control Specific Application** – This permission allows a specific role to gain permission to access/control a specific data application which must be identified by its application ID as defined in T.120. + +**Control Specific Device** – This permission allows a specific role to gain permission to access/control a specific device. + +#### Audio management and control + +**Control Audio Mixes** – This permission allows the role holder the ability to control who or what is mixed into the audio for the meeting room. + +**Control Audio Devices** – This permission allows the role holder permission to control other audio devices available within the conference room. + +**Invite/Eject Audio-only participants** – This permission allows the role holder to bring in audio-only participants to the conference by dialling out to them. + +**Mutable** – This permission defines if the role holder's audio stream(s) are mutable or if they are always mixed. + +##### Video management and control + +**Control Video Devices** – This permission allows the role holder permission to control video devices available within the conference room. + +**View Video Apps** – This permission allows the role holder the ability to view video applications, although this is available for participants, by default. The removal of this feature allows, for example, the ability to shield sensitive material from an operator assisting in the conference. + +### 9.8.2 Room Roles – Description of abstract services + +Following is a list of the primitives defined in this subclause and a brief summary of the function of each: + +- **MRM-Room-Role-Assign** – Used by a node controller to request the assignment of a room role. When a node takes on a role, e.g. chair, a successful bid results in a roster update to the room. +- **MRM-Room-Role-Release** – Used by a node controller to release the specified role in a room. When any node releases a role, the release results in a roster update to the room. +- **MRM-Room-Role-Please** – Used by a node controller to request that a role be given to it from the current room role holder. +- **MRM-Room-Role-Give** – Used by a node controller to pass a role to a specified node. +- **MRM-Room-Role-Inquire** – Used by a node controller to determine whether the room currently has a specific active role and, if it does, what the role holder's MRM User ID is, or if no role is specified, then a list of roles present in the conference is returned. +- **MRM-Role-Permissions-Modify** – This primitive is only used by a node with role modification permissions, in order to modify role permissions. + +#### 9.8.2.1 MRM-Room-Role-Assign + +*Protocol link: 10.10.1* + +When a defined MRM role is not assigned, a participant's node controller at any node has the possibility to issue a request to take on that role, by issuing a MRM-Room-Role-Assign request primitive. The result parameter, returned in the confirm primitive, indicates if the requester has been assigned the role or not. A successful MRM-Room-Role-Assignment results in a Roster Update to all nodes that are in the room. + +Figure 19 shows the sequence of events when using this primitive. + +![Sequence diagram showing the MRM-Room-Role-Assign process. A Node Controller sends an MRM-Room-Role-Assign request to an MRM Provider, which responds with an MRM-Room-Role-Assign confirm. The MRM Top Provider then sends an MRM-Roster-Update indication to Network Elements and All nodes in same MRM Room.](cbab05075b3d7dc0d27c4cbb0c914a94_img.jpg) + +Node Requesting Role + +``` + +sequenceDiagram + participant NC as Node Controller + participant MP as MRM Provider + participant MTP as MRM Top Provider + participant NE as Network Elements and All nodes in same MRM Room + + NC->>MP: MRM-Room-Role-Assign request + MP-->>NC: MRM-Room-Role-Assign confirm + MTP->>NE: MRM-Roster-Update indication + +``` + +T1607530-99 + +Sequence diagram showing the MRM-Room-Role-Assign process. A Node Controller sends an MRM-Room-Role-Assign request to an MRM Provider, which responds with an MRM-Room-Role-Assign confirm. The MRM Top Provider then sends an MRM-Roster-Update indication to Network Elements and All nodes in same MRM Room. + +**Figure 19/T.137 – MRM-Room-Role-Assign – Sequence of primitives** + +The assignment of a role by the MRM top provider occurs in response to a framework requirement identifying a participant (through the role key) as the role holder. (See Figure 20.) + +![Sequence diagram showing the MRM-Roster-Update indication from the MRM Top Provider to the Node Being Assigned Role.](7ed5d5770331f31ade15439a21c31425_img.jpg) + +``` + +sequenceDiagram + participant MTP as MRM Top Provider + participant MP as MRM Provider + participant NBAR as Node Being Assigned Role + + MTP->>MP: MRM-Roster-Update indication + MP->>NBAR: MRM-Roster-Update indication + +``` + +T1607540-99 + +Sequence diagram showing the MRM-Roster-Update indication from the MRM Top Provider to the Node Being Assigned Role. + +**Figure 20/T.137 – MRM-Room-Role-Assign: Assignment by MRM Top Provider – Sequence of primitives** + +Table 18 shows the parameters and types of this primitive. + +**Table 18/T.137 – MRM-Room-Role-Assign – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|----------------------------------|---------|------------|---------| +| Request Handle | M | | M(=) | +| Requesting Node MRM User ID | | M | | +| Proposed Role Holder MRM User ID | O | O(=) | | +| MRM Room Identifier | M | M(=) | | +| MRM Room Role Identifier | C | M(=) | | +| MRM Role Access Key | C | M | M | +| Group identifier | O | O | O | +| Result | | | M | + +**Request Handle:** Locally unique identifier to allow the requesting node to match responses. + +**Requesting Node MRM User ID:** Identification number of the requesting node. + +**Proposed Role Holder MRM User ID {list}:** Required if the requester is not the node requiring the role or the request is for more than one role assignment as would be the case when group membership was being defined. + +**MRM Room Identifier:** The identifier for the MRM room – It is mandatory to provide the Room ID in the request unless an access key is provided in which case the TOP Provider can resolve the correct room and the parameter is optional. + +**MRM Room Role Identifier:** This parameter identifies the specific room role "Chair, Presenter, Group Member". It is mandatory to provide the room role in the request unless an access key is provided in which case the top provider can still resolve the corresponding role assignment, and the parameter becomes optional. + +**MRM Role Access Key:** This parameter provides an access key which the requester may optionally provide in a request. If provided, it is used by the MRM top provider to validate the request against the conference framework access controls. + +**Group Identifier:** If the Group ID is specified, the assign role only has scope within that group. This allows a group leader to be defined. + +**Result:** An indication of whether the request was accepted or rejected, and, if rejected, of the reason why. It contains one of the following possible results: Successful, Invalid room, Role not permitted, Role already assigned, Not group member. + +##### **Case of updating late joiners:** + +Room role assignments are recorded in the room roster and changes are notified in Roster Updates. If a new node joins after a role has been assigned, they will see the role assignment in the roster report they receive. + +##### **Case of active chair:** + +The MRM top provider checks if any active role has "authorize room transaction" privilege. If a node does, the MRM top provider will carry out an extra authorization process with the authorizing node in order to obtain authorization for a role assignment before proceeding. + +#### 9.8.2.2 MRM-Room-Role-Release + +*Protocol link: 10.10.2* + +When an MRM node holding an active MRM role wishes to relinquish that role, it issues an MRM-Room-Role-Release request primitive. The request is sent to the MRM top Provider which will inform all nodes in the room of the change in operational mode by means of the MRM-Roster-Update indication. The order of role assignments and role releases represents the actual order of role holder transitions. Any participant issuing a MRM-Room-Role-Release request, but not being the current role holder, shall be answered by the MRM top provider with an MRM-Room-Role-Release confirmation containing a negative result and reason description. In this situation no indications shall be sent to the other participants. The MRM top provider can initiate a role release as a result of a role holder having disconnected from the conference. + +The MRM top provider will execute a role release locally and issue a RosterUpdateIndication in the case where a node is detected leaving the MRM room or the conference. This update will contain updated role information as well as updated participation information. + +Figure 21 shows the sequence of events when using this primitive. Table 19 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-Room-Role-Release process. A Node Controller sends an MRM-Room-Role-Release request to the MRM Provider. The MRM Provider sends an MRM-Room-Role-Release confirm back to the Node Controller. The MRM Top Provider sends an MRM-Roster-Update indication to Network Elements and All nodes in same MRM Room.](28085f681b9fff76a53c5b8b32338ee1_img.jpg) + +Node Relinquishing Role + +``` +sequenceDiagram + participant NC as Node Controller + participant MP as MRM Provider + participant MTP as MRM Top Provider + participant NE as Network Elements and All nodes in same MRM Room + + NC->>MP: MRM-Room-Role-Release request + MP-->>NC: MRM-Room-Role-Release confirm + MTP->>NE: MRM-Roster-Update indication +``` + +The diagram illustrates the sequence of events for a user-initiated MRM-Room-Role-Release. It involves four main entities: Node Controller, MRM Provider, MRM Top Provider, and Network Elements (All nodes in same MRM Room). The process begins with the Node Controller sending an 'MRM-Room-Role-Release request' to the MRM Provider. The MRM Provider then sends an 'MRM-Room-Role-Release confirm' back to the Node Controller. Subsequently, the MRM Top Provider sends an 'MRM-Roster-Update indication' to the Network Elements, which represent all nodes in the same MRM Room. + +Sequence diagram showing the MRM-Room-Role-Release process. A Node Controller sends an MRM-Room-Role-Release request to the MRM Provider. The MRM Provider sends an MRM-Room-Role-Release confirm back to the Node Controller. The MRM Top Provider sends an MRM-Roster-Update indication to Network Elements and All nodes in same MRM Room. + +**Figure 21/T.137 – MRM-Room-Role-Release (User Initiated) – Sequence of primitives** + +**Table 19/T.137 – MRM-Room-Role-Release – Types of primitives and their parameters** + +| Parameter | Request | Confirm | +|--------------------------|---------|---------| +| Request Handle | M | M(=RQ) | +| MRM Room Identifier | M | M(=) | +| MRM Room Role Identifier | M | M(=) | +| Room Role Label | C | | +| Group Identifier | O | | +| Release Reason | | | +| Result | | M | + +**Request Handle:** Locally unique identifier to allow the requesting node to match responses. + +**MRM Room Identifier:** The identifier for the MRM room. + +**MRM Room Role Identifier:** This parameter identifies the specific room role to be released. + +**Room Role Label:** A single word such, as "Presenter", used to identify a user-defined role. + +**Group Identifier:** The group identifier is an optional parameter; it allows a role within a group to be identified. + +**Release Reason:** The reason parameter can provide additional information within indication messages concerning the release, e.g. presenter initiated, or system initiated. + +**Result:** An indication of whether the request was accepted or rejected, and, if rejected of the reason why. It contains one of the following possible results: Successful, Invalid room, Not role holder, Invalid group. + +#### 9.8.2.3 MRM-Room-Role-Please + +*Protocol link: 10.10.3* + +The primitive MRM-Room-Role-Please request may be issued by a node controller to ask the current role holder to give the role to the requesting node. The MRM-Room-Role-Please indication is forwarded to the current role holder. The current role holder may then choose to give the role to the requester by using the MRM-Room-Role-Give primitive. The confirm portion of this primitive is only local confirmation that the request was accepted by the local MRM provider. No confirmation from the role holder is given directly. + +NOTE – This primitive is not applicable to groups, only to individual roles. + +Figure 22 shows the sequence of events when using this primitive. Table 20 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-Room-Role-Please sequence of primitives between a Node Controller, two MRM Providers, and a Role Holder Node Controller.](6f11044c88ea04e43de06c3491defeee_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant MP1 as MRM Provider + participant MP2 as MRM Provider + participant RNC as Role Holder Node Controller + + NC->>MP1: MRM-Room-Role-Please request + MP1->>MP2: MRM-Room-Role-Please indication + MP2->>RNC: MRM-Room-Role-Please indication + RNC-->>MP1: MRM-Room-Role-Please confirm + MP1-->>NC: MRM-Room-Role-Please confirm + +``` + +The diagram illustrates the sequence of primitives for the MRM-Room-Role-Please operation. It involves four entities: a Node Controller, two MRM Providers, and a Role Holder Node Controller. The sequence begins with the Node Controller sending an 'MRM-Room-Role-Please request' to the first MRM Provider. This provider then sends an 'MRM-Room-Role-Please indication' to the second MRM Provider, which in turn sends the same indication to the Role Holder Node Controller. Finally, the Role Holder Node Controller sends an 'MRM-Room-Role-Please confirm' message back to the second MRM Provider, which then forwards the confirmation to the first MRM Provider, and finally to the original Node Controller. + +Sequence diagram showing the MRM-Room-Role-Please sequence of primitives between a Node Controller, two MRM Providers, and a Role Holder Node Controller. + +**Figure 22/T.137 – MRM-Room-Role-Please – Sequence of primitives** + +**Table 20/T.137 – MRM-Room-Role-Please – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|-----------------------------|---------|------------|---------| +| Request Handle | M | – | M(=) | +| Requesting Node MRM User ID | | M(=) | | +| MRM Room Identifier | M | M(=) | | +| MRM Room Role Identifier | M | M(=) | | +| Group Identifier | O | O(=) | | +| Result | | | M(=) | + +**Request Handle:** Locally Unique identifier to allow the requesting node to match responses. + +**Requesting Node MRM User ID:** The MRM User ID of the requesting node. + +**MRM Room Identifier:** The MRM Room Identifier the room request relates to. + +**MRM Room Role Identifier:** Chair, Presenter. + +**Result:** An indication of whether the request was accepted or rejected, and, if rejected, of the reason why. It contains one of the following possible results: Successful, Not role holder. + +#### 9.8.2.4 MRM-Room-Role-Give + +*Protocol link: 10.10.4* + +The primitive MRM-Room-Role-Give request may be issued by a node controller at the role holder's node, to transfer a role to another node. If the role is not accepted by the intended recipient, the role continues to be held by the current holder. + +Figure 23 shows the sequence of events when using this primitive. Table 21 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-Room-Role-Give process between four entities: Current Role Holder or Top Provider Node Controller, MRM Provider, MRM Top Provider, and Recipient Node Node Controller. The process involves a request, indication, response, confirm, and update steps.](7e14467740b2570a44379b347a697921_img.jpg) + +``` + +sequenceDiagram + participant C as Current Role Holder +or Top Provider +Node Controller + participant M1 as MRM Provider + participant M2 as MRM Top Provider + participant R as Recipient Node +Node Controller + + C->>M1: MRM-Room-Role-Give request + M1->>M2: MRM-Room-Role-Give indication + M2->>R: MRM-Room-Role-Give response + R-->>M1: MRM-Room-Role-Give confirm + M2->>M1: Room-Role-Give indication + M2->>R: MRM-Roster-Update indication + +``` + +T1607570-99 + +Sequence diagram showing the MRM-Room-Role-Give process between four entities: Current Role Holder or Top Provider Node Controller, MRM Provider, MRM Top Provider, and Recipient Node Node Controller. The process involves a request, indication, response, confirm, and update steps. + +**Figure 23/T.137 – MRM-Room-Role-Give – Sequence of primitives** + +**Table 21/T.137 – MRM-Room-Role-Give – Types of primitives and their parameters** + +| Parameter | Request | Indication | Response | Confirm | +|---------------------------|---------|------------|----------|---------| +| Request Handle | M | | | M(=RQ) | +| Role Holder's MRM User ID | | M | M(=) | | +| Recipient Node | M | M(=) | M(=) | | +| MRM Room Identifier | M | M(=) | M(=IN) | M(=RQ) | +| MRM Room Role Identifier | M | M(=) | M(=) | M(=) | +| Group Identifier | O | O(=) | O(=) | O(=) | +| Result | | | M | M(=) | + +**Request Handle:** Locally unique identifier to allow the requesting node to match responses. + +**Role Holder's MRM User ID:** Identification number of the role holder's terminal. + +**Recipient Node:** The MRM User ID of the node to which the role is being transferred. + +**Group Identifier:** The group identifier is an optional parameter; it allows a group to be defined by participants. This parameter is ignored in cases where it is not applicable, e.g. if the role is that of chair – as only one chair is permitted in a room. In the case of the presenter role, the default presenter group panel {0} will be automatically assumed if no group is specified. + +**Result:** An indication of whether the request was accepted or rejected and, if rejected, of the reason why. It contains one of the following possible results: Successful, Invalid room, Not role holder, Give not accepted. + +#### 9.8.2.5 MRM-Room-Role-Enquire + +The primitive MRM-Room-Role-Enquire request may be issued at any time by either a node controller or application protocol entity in order to find out if a specific role is active or not, and, if so, which node is the role holder. If the information is not stored locally, the MRM provider may need to retrieve it from the MRM top provider. + +Figure 24 shows the sequence of events when using this primitive. Table 22 shows the parameters and types of this primitives. + +![Sequence diagram showing the interaction between a Node Controller or Application Protocol Entity and an MRM Provider. The Node Controller sends an MRM-Room-Role-Enquire request to the MRM Provider, and the MRM Provider returns an MRM-Room-Role-Enquire confirm to the Node Controller.](fd3cbb53e991f8209ba17b398f426e13_img.jpg) + +``` + +sequenceDiagram + participant N as Node Controller or +Application Protocol Entity + participant M as MRM Provider + N->>M: MRM-Room-Role-Enquire +request + M-->>N: MRM-Room-Role-Enquire +confirm + +``` + +T1607580-99 + +Sequence diagram showing the interaction between a Node Controller or Application Protocol Entity and an MRM Provider. The Node Controller sends an MRM-Room-Role-Enquire request to the MRM Provider, and the MRM Provider returns an MRM-Room-Role-Enquire confirm to the Node Controller. + +**Figure 24/T.137 – MRM-Room-Role-Enquire – Sequence of primitives** + +**Table 22/T.137 – MRM-Room-Role-Enquire – Types of primitives and their parameters** + +| Parameter | Request | Confirm | +|--------------------------------|---------|---------| +| MRM Room Identifier | M | M | +| MRM Room Role Identifier | M | M | +| Role Holder Node (MRM User ID) | | C | +| Group Identifier | O | O(=) | +| Result | | M | + +**MRM Room Identifier:** MRM ID of the room. + +**MRM Room Role Identifier:** The role identifier for the role. + +**Role Holder User ID:** The MRM User ID of the node that is currently role holder. Not present if the role is currently unassigned. + +**Group Identifier:** The group identifier is a numeric identifier that allows groups to be distinguished. It is an optional parameter and is ignored in cases where it is not applicable – e.g. if the role is chair – as only one chair is permitted in a room. In the case of the presenter role, the default presenter group Panel {0} will be automatically assumed if no group is specified. + +**Result:** An indication of whether the request was accepted or rejected, and, if rejected, of the reason why. It contains one of the following possible results: Successful, Invalid room ID, Invalid Role ID, Invalid Group ID. + +#### 9.8.2.6 MRM-Role-Permissions-Modify + +Protocol link: 10.10.5 + +An MRM role holder with appropriate permissions is able to modify the role permissions of other role holders in the same room. However, the node modifying permissions is only able to modify permissions that it itself has privileges for. This means only the convenor has access to all role permissions once the conference has started. Participants can only enhance their permissions set by taking on an available pre-defined role. + +Figure 25 shows the sequence of events when using this primitive. Table 23 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-Role-Permissions-Modify process. A Node Controller sends an MRM-Role-Permissions-Modify request to an MRM Provider. The MRM Provider then sends an MRM-Role-Permissions-Modify confirm back to the Node Controller. Simultaneously, the MRM Provider sends an MRM-Roster-Update indication to an MRM Top Provider, which then sends an MRM-Roster-Update indication to another MRM Provider.](1f1614411edea7edfc86c839a608e1fc_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant MP1 as MRM Provider + participant MTP as MRM Top Provider + participant MP2 as MRM Provider + + NC->>MP1: MRM-Role-Permissions-Modify request + MP1-->>NC: MRM-Role-Permissions-Modify confirm + MP1->>MTP: MRM-Roster-Update indication + MTP->>MP2: MRM-Roster-Update indication + +``` + +Sequence diagram showing the MRM-Role-Permissions-Modify process. A Node Controller sends an MRM-Role-Permissions-Modify request to an MRM Provider. The MRM Provider then sends an MRM-Role-Permissions-Modify confirm back to the Node Controller. Simultaneously, the MRM Provider sends an MRM-Roster-Update indication to an MRM Top Provider, which then sends an MRM-Roster-Update indication to another MRM Provider. + +Figure 25/T.137 – MRM-Role-Permissions-Modify – Sequence of primitives + +Table 23/T.137 – MRM-Role-Permissions-Modify – Types of primitives and their parameters + +| Parameter | Request | Confirm | +|-------------------------|---------|---------| +| Request Handle | M | M(=) | +| Role Holder MRM User ID | M | | +| Suspend/Resume Flag | M | | +| Permissions List | C | C | +| Result | | M(=) | + +**Request Handle:** Locally unique identifier to allow the requesting node to match responses. + +**Role Holder MRM User ID:** The User ID of the role holder whose permissions are to be modified. + +**Suspend/Resume Flag:** This flag allows a role holder to suspend or resume a role it holds, allowing a role holder to continue to hold a role but to stop any actions that result from the privileges that it holds, until the role is resumed again. + +**Permissions List:** A list of privilege flags: Create Role, Pass Role, Ask for Role, Modify Role Permissions, Modify Other Role Holder Permissions, Chair Authorizes Role request, Create/Mod/Destroy child rooms, Child Rooms Inherit Parent Roles, Create/Modify/Destroy groups, Change Group Ordering, Start/Stop floor Control, Request Floor, Modify room parameters, Operate + +Floor Control, Authorize room transactions, Invite/Eject participants, View Data Apps, Control Data Apps, Control Devices, Exclusive Control of Data App(s), View Specific Application, Control Specific Application, Control Audio Mixes, Control Audio Devices, Invite audio Only participants, Mutable, Control Video Devices, View Video. + +**Result:** An indication of whether the request was accepted or rejected, and, if rejected, of the reason why. It contains one of following possible results: Successful, Not authorized, Invalid role holder ID. + +### 9.8.3 The chair role + +The chair role operates within the context of the MRM conference room in which that role is assigned. A chair role may be pre-assigned by a convenor as part of the framework, the convenor may also assign a chair access key for the room. A particular participant who has been pre-assigned a role such as the chair can be provided with the access key (out of band) corresponding to the access key for that role in the framework. When the pre-defined chair joins the conference, the access key is passed to the conference manager which will validate the key against the framework and automatically generate an appropriate role assignment resulting in the designated node being assigned the requested role. + +If the chair role is not prohibited by the current conference framework, then MRM participants may request and compete for the role as required and, if successful, act as chair for the room. If the chair is defined in the framework with an access key only the requester who provides the correct access key is assigned the role. The framework does not prohibit the role being asked for by participants or being given by the chair role holder. + +An active chair automatically becomes the arbiter for the floor control service and, consequently, the floor control service requires a chair in order to operate. Only one chair is permitted within a room; therefore a conference containing multiple rooms may have multiple chair roles active. + +#### 9.8.3.1 Chair assignment + +In a room without a chair, the node controller at any participating node has the possibility to issue a request to become the chairperson, by issuing an MRM-Room-Role-Assign request primitive with the identifier set to chair. The receipt of the associated MRM-Room-Role-Assign confirm primitive indicates whether the requester has become the chair or not, depending on the result parameter within the primitive. A successful MRM-Room-Role-Assign request shall be accompanied by an MRM-Roster-Update-Indication, sent to all node controllers at all nodes in the room, signalling that the room has a chair, and giving information about the identity of the chair. See Table 18 and Figure 19. + +#### 9.8.3.2 Releasing the chair role + +In order to relinquish the chair role, the node controller at the chair node issues the MRM-Room-Role-Release request primitive. As soon as the Chair has requested the release of chair, all node controllers in the room are informed of the change in operational mode by means of the MRM-Roster-Update indication. Any participant issuing an MRM-Room-Role-Release, but not being the current chair, shall be answered by MRM with an MRM-Room-Role-Release confirmation containing a negative result and reason description. In this situation no indications shall be sent to the other participants. Apart from this user-initiated transition to non-conducted mode, the release of chair role can also be initiated by MRM itself, for instance because the chair leaves the room or is disconnected from the conference. See Table 19 and Figure 21. + +#### 9.8.3.3 Asking for the chair role + +The primitive MRM-Room-Role-Please request may be issued by a node controller to ask the current chair to give the chair to the requesting node. The MRM-Room-Role-Please indication is forwarded to the current conducting node. The current chair may then choose to give the chair to the requester by using the MRM-Room-Role-Give primitive. The confirm portion of this primitive is + +only local confirmation that the request was accepted by the local MRM provider. No confirmation from the Chair is given directly. See Table 20 and Figure 22. + +#### **9.8.3.4 Giving the chair role** + +The primitive "MRM-Room-Role-Give" request may be issued by a node controller to transfer the chair to a specific node. If the chair role is not accepted by the intended recipient, the conference chair continues to be held by the original Chair. See Table 21 and Figure 23. + +#### **9.8.3.5 Asking about the chairperson** + +The primitive MRM-Room-Role-Inquire request may be issued at any time by either a node controller or application protocol entity in order to find out whether the conference is chaired or not, and if so, which node is the chair, and if the requesting node has been granted conducted-mode permission. See Table 22 and Figure 24. + +### **9.8.4 Accessing pre-defined roles** + +When a room participant has been pre-allocated a role within a room, this role will have been assigned an access key in order to ensure only the desired node is able to obtain that role. The convenor will have specified the role and associated key in the conference framework and this will have been passed to the intended recipient, by some means, out of band to MRM. The pre-allocated role holders must issue an MRM-Room-Role-Assign request providing the Role ID and Access Key together with a Group ID if available. This result will be sent to the top provider where it will be validated and the role assigned. + +### **9.8.5 Asking a role holder for permission to Act** + +One of the role privileges is to be allowed to arbitrate actions of participants within the room or wishing to access the room. An MRM role holder such as a chair is able to act as an arbiter giving explicit permission before a room participant or observer can carry out an action. + +## **9.9 Permission to take action (Incorporating floor control)** + +### **9.9.1 Description of abstract services** + +Following is a list of the primitives defined in this subclause and a brief summary of the function of each: + +- MRM-Permission-Ask – This primitive is used by a node controller to ask permission from a chair, or other role-holding node. +- MRM-Permission-Relinquish – This primitive is used to return a previously requested permission, when it is no longer required. +- MRM-Permission-Grant – This primitive is used to grant a node permission to take a specified action. + +The MRM permission primitives are provided to allow room participants to be able to request the use of conference services or to take specific actions from a room's chairperson or another node with authorization privileges. They are only relevant when a room has an active chair. In the absence of an active chair, or another authorizing node, nodes may act within their existing privileges. The specific meaning of requesting the floor is dependent on either the service context or the specific permission specified. For example, if audio services are active, the default action will be requesting to have audio included in the conference audio mix; however, the request has a service field that allows the floor control protocol to be used with other services. Floor control can only be used in a chaired room, and the chairperson is responsible for granting requests. Therefore, floor control can only operate when the Room has an active chairperson. When a chair is assigned, MRM-Role-Assign indications are sent to the node controllers at all nodes in the room, signalling that the room + +has a chair, and giving information about the identity of the chair. When the room chair is assigned, the floor control capability becomes available and the chair can then launch the service as needed. + +Once the service becomes active, all audio sources except the chair are muted at the mixer by the service using the Set-Audio-Mixer primitives. Room participants can issue floor requests which are directed to the chair, who can grant or decline the requests. Participants can release the floor when they have completed their requirements. + +This service provides the mechanism that allows conference participants to make requests to speak in a chaired conference and for the chair to enable and disable participants from speaking. + +The audio mixing service is aware of and utilizes three room roles that participating nodes can adopt in operating the service: + +- **Chair role** – If the floor control has been launched, the chair becomes the arbiter for floor requests; if the service has not been launched, the chair may launch it, as may a convenor or convenor privileged node. + +NOTE – By means of the framework or the alignment parameter in the floor control service, the conference conductor can take on the role of MRM room chair. +- **Participant role** – With respect to the floor control service, participants may be either Anonymous or Conventional nodes. All participant nodes will initially be muted at their local mixer when floor control is launched within a chaired room. Individuals or a group may request and be assigned the floor by the chair. Assignment of the floor will have the effect of having their audio stream included in the audio mix. +- **Observer role** – Observers are primarily viewers of media and events within the room; however, MRM supports the limited interaction through the floor control service. Requests to interact are made through the conference manager on the observer communication channel. The conference manager has access to the identity of observers even though they appear anonymous to other participants and do not appear in the room roster. The conference manager can generate requests for the floor on their behalf, thus allowing the possibility of interaction within the conference. +- **Audio-only role** – Audio-only participants are proxied for by the MRM top provider. The mechanism is a local matter. + +It is not mandatory that all participating nodes be capable of supporting the service in order for it to be used. The chair may decide to launch the floor control service regardless: this will still result in the desired control, however, nodes not supporting the service will not be able to make floor requests in the conventional way. + +When the floor control service is invoked by issuing a Service Command primitive, the initiating chair or the MRM conference framework specifies if the service is to be used for audio only or for both audio and video together. The MRM top provider will, on successful launch of the floor control service, set the Audio Mixer mode to "Floor Controlled", and the mixing service will then accept the command from the rooms' designated chair. + +For audio control, the initial condition is determined by the framework. By default, all audio sources are muted at the mixer except that of the chair; video (if present) will continue in the current operational mode. Nodes other than the chair wishing to speak make a Permission-Ask request to the chair. The chair may decide to grant or refuse the request. Normally, requests will either be granted by the chair or be held in a queue in received order until the chair is ready to add a new speaker. The chair may also effectively remove any speaker by muting their audio source at the mixer. + +For video control, the audio can be set to track the video regardless of previous modes in operation. + +The chair initiates the control by communicating with mixer(s) via the MRM-Conference-Management-Channel. In voice-switched mode, the action of the video is linked to the output of the audio mixer and is therefore indirectly controlled as well. + +#### 9.9.1.1 MRM-Permission-Ask request + +*Protocol link: 10.11.1* + +The MRM-Permission-Ask request primitive is issued by the node controller of any node within a conference room that wishes to obtain permission for an action which impacts upon the room. + +Figure 26 shows the sequence of events when using this primitive. + +![Sequence diagram for MRM-Permission-Ask request initiated by a Node Controller.](343e05a9fd8a8c8743428fa4ae6e2736_img.jpg) + +``` +sequenceDiagram + participant NC as Node Controller + participant MP1 as MRM Provider + participant MP2 as MRM Provider + participant AN as Node Controller +Authorizing Node + NC->>MP1: MRM-Permission-Ask request + MP1->>MP2: + MP2->>AN: MRM-Permission-Ask indication + MP1-->>NC: MRM-Permission-Ask confirm +``` + +The diagram illustrates the sequence of events for an MRM-Permission-Ask request initiated by a Node Controller. It involves four participants: Node Controller, MRM Provider, MRM Provider, and Node Controller Authorizing Node. The sequence is as follows: 1. The first Node Controller sends an 'MRM-Permission-Ask request' to the first MRM Provider. 2. The first MRM Provider sends a message to the second MRM Provider. 3. The second MRM Provider sends an 'MRM-Permission-Ask indication' to the Node Controller Authorizing Node. 4. The first MRM Provider sends an 'MRM-Permission-Ask confirm' back to the first Node Controller. The diagram is labeled T1607600-99. + +Sequence diagram for MRM-Permission-Ask request initiated by a Node Controller. + +**Figure 26/T.137 – MRM-Permission-Ask Request: User initiated – Sequence of primitives** + +The MRM Top Provider may initiate an MRM-Permission-Ask when it detects that a permission for a given action is required from an active role holder. (See Figure 27.) + +![Sequence diagram for MRM-Permission-Ask initiated by the MRM Top Provider.](ada2aa7cce9cff9cf116d9ae2b8b7c27_img.jpg) + +``` +sequenceDiagram + participant MTP as MRM Top Provider + participant MP as MRM Provider + participant RHNC as Role Holder +Node Controller + MTP->>MP: + MP->>RHNC: MRM-Permission-Ask indication +``` + +The diagram illustrates the sequence of events for an MRM-Permission-Ask initiated by the MRM Top Provider. It involves three participants: MRM Top Provider, MRM Provider, and Role Holder Node Controller. The sequence is as follows: 1. The MRM Top Provider sends a message to the MRM Provider. 2. The MRM Provider sends an 'MRM-Permission-Ask indication' to the Role Holder Node Controller. The diagram is labeled T1607610-99. + +Sequence diagram for MRM-Permission-Ask initiated by the MRM Top Provider. + +**Figure 27/T.137 – MRM-Permission-Ask – Top Provider Initiated – Sequence of primitives** + +Table 24 shows the parameters and types of this primitive. + +**Table 24/T.137 – MRM-Permission-Ask Request – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|-----------------------------|---------|------------|---------| +| Request Handle | M | | M(=) | +| Requesting Node MRM User ID | | M | | +| MRM Room Identifier | M | M(=) | | +| Permission Requested Handle | O | O(=) | | +| Group Permission Request | O | O(=) | | +| Associated Service | O | O(=) | | +| Result | | | M | + +**Request Handle:** Locally unique number to allow the requesting node to match responses. + +**Requesting Node MRM User ID:** User ID of the requesting terminal. + +**MRM Room Identifier:** The identifier for the MRM room. + +**Permission Requested Handle:** Choice of: Enter room, Request to speak/Request to be seen/Request to use the whiteboard/Request to share an application. + +**Group Permission Request:** Group ID – Used if the requester is making a request on behalf of the specified group to which it belongs. + +**Associated Service:** The means to associate an MRM standardized service or a user-defined service. + +**Result:** An indication of whether the request was accepted or rejected, and, if rejected, of the reason why. It contains one of the following possible results: Successful, Refused by chair. + +#### 9.9.1.2 MRM-Permission-Relinquish + +*Protocol link: 10.11.2* + +This primitive is issued by a node that has previously obtained permission for an action such as requesting the floor, either to cancel a pending request or to request to be removed from current floor activity. + +The sequences of primitives belonging to both situations are depicted in Figure 28. Table 25 shows the parameters and types of this primitive. + +![Sequence diagram showing the MRM-Permission-Relinquish process. It involves four lifelines: Node Controller, MRM Provider, MRM Provider, and Node Controller Authorizing Node. The sequence is: 1. Node Controller sends MRM-Permission-Relinquish request to MRM Provider. 2. MRM Provider sends MRM-Permission-Relinquish confirm back to Node Controller. 3. MRM Provider sends MRM-Permission-Relinquish indication to Node Controller Authorizing Node. 4. Node Controller Authorizing Node sends MRM-Roster-Update indication to Node Controller Other nodes in the room.](6a7ea9d5162b0a0cfbd8d77c6cac90d1_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant MP1 as MRM Provider + participant MP2 as MRM Provider + participant NCA as Node Controller Authorizing Node + participant NCO as Node Controller Other nodes in the room + + NC->>MP1: MRM-Permission-Relinquish request + MP1-->>NC: MRM-Permission-Relinquish confirm + MP1->>NCA: MRM-Permission-Relinquish indication + NCA->>NCO: MRM-Roster-Update indication + +``` + +T1607620-99 + +Sequence diagram showing the MRM-Permission-Relinquish process. It involves four lifelines: Node Controller, MRM Provider, MRM Provider, and Node Controller Authorizing Node. The sequence is: 1. Node Controller sends MRM-Permission-Relinquish request to MRM Provider. 2. MRM Provider sends MRM-Permission-Relinquish confirm back to Node Controller. 3. MRM Provider sends MRM-Permission-Relinquish indication to Node Controller Authorizing Node. 4. Node Controller Authorizing Node sends MRM-Roster-Update indication to Node Controller Other nodes in the room. + +**Figure 28/T.137 – MRM-Permission-Relinquish – Sequence of primitives** + +**Table 25/T.137 – MRM-Permission-Relinquish – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|-----------------------------|---------|------------|---------| +| Request Handle | M | | M(=) | +| Requesting Node MRM User ID | | M | | +| MRM Room Identifier | M | M(=) | | +| Release Reason | O | C | | +| Permission Relinquished | M | M | | +| Group Permission | O | O(=) | | +| Associated Service | O | O(=) | | +| Result | | | M | + +**Request Handle:** Locally unique number to allow the requesting node to match responses. + +**Requesting Node MRM User ID:** Identifier of the node requesting the release of the floor. + +**Release Reason:** This parameter can provide additional information within indication messages concerning the release, e.g. chair initiated, or system initiated. + +**Permission Relinquished:** Permission identifier. + +**Group Permission Relinquished:** Used if the requester is making a request on behalf of the specified group to which it belongs. + +**Associated Service:** Audio Mixing is assumed by default; if a parameter is provided, it overrides the default. + +**Result:** An indication of whether the request was accepted or rejected, and, if rejected, of the reason why. It contains one of the following possible results: Successful, Invalid room. + +#### 9.9.1.3 MRM-Permission-Grant + +*Protocol link: 10.11.3* + +The MRM-Permission-Grant primitive is issued by the node controller of a room chairing node in response to a previous Permission-Ask request. + +Figure 29 shows the sequence of events when using this primitive. Table 26 shows the parameters and types of this primitive. + +![Sequence diagram showing the MRM-Permission-Grant process. The diagram involves four lifelines: Node Controller (Chairing node), MRM Provider (Chairing node), MRM Provider (Authorizing Node), and Node Controller (Other nodes in the room). The sequence is: 1. Node Controller (Chairing node) sends MRM-Permission-Grant request to MRM Provider (Chairing node). 2. MRM Provider (Chairing node) sends MRM-Permission-Grant indication to MRM Provider (Authorizing Node). 3. MRM Provider (Authorizing Node) sends MRM-Permission-Grant confirm to Node Controller (Chairing node). 4. MRM Provider (Authorizing Node) sends MRM-Roster-Update indication to Node Controller (Other nodes in the room).](9cb54072e43a6b6717eb16036a7640a2_img.jpg) + +``` + +sequenceDiagram + participant NC1 as Node Controller +Chairing node + participant MP1 as MRM Provider +Chairing node + participant MP2 as MRM Provider +Authorizing Node + participant NC2 as Node Controller +Other nodes in the room + + NC1->>MP1: MRM-Permission-Grant request + MP1->>MP2: MRM-Permission-Grant indication + MP2-->>NC1: MRM-Permission-Grant confirm + MP2->>NC2: MRM-Roster-Update indication + +``` + +Sequence diagram showing the MRM-Permission-Grant process. The diagram involves four lifelines: Node Controller (Chairing node), MRM Provider (Chairing node), MRM Provider (Authorizing Node), and Node Controller (Other nodes in the room). The sequence is: 1. Node Controller (Chairing node) sends MRM-Permission-Grant request to MRM Provider (Chairing node). 2. MRM Provider (Chairing node) sends MRM-Permission-Grant indication to MRM Provider (Authorizing Node). 3. MRM Provider (Authorizing Node) sends MRM-Permission-Grant confirm to Node Controller (Chairing node). 4. MRM Provider (Authorizing Node) sends MRM-Roster-Update indication to Node Controller (Other nodes in the room). + +**Figure 29/T.137 – MRM-Permission-Grant – Sequence of primitives** + +**Table 26/T.137 – MRM-Permission-Grant – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|-------------------------|---------|------------|---------| +| Request Handle | M | | M(=) | +| Requester's MRM User ID | M | | | +| MRM Room Identifier | M | M= | | +| Permission Granted | M | M= | M(=) | +| Group Permission Grant | O | O= | | +| Associated Service | O | O= | | +| MRM Access Capability | O | O= | | +| Result | | | M(=) | + +**Request Handle:** Locally unique number to allow the requesting node to match responses. + +**Requester MRM User ID:** Identification number of the node previously requesting the floor. + +**MRM Room Identifier:** The identifier for the MRM room. + +**Permission Granted:** Choice of permissions. + +**Group Permission Grant:** Used if the requester is making a request on behalf of the specified group to which it belongs. + +**Associated Service:** Audio Mixing assumed by default; if a parameter is provided, it overrides the default. + +**MRM Access Capability:** List of functionality to which access has been granted. + +**Result:** An indication of whether the request was accepted or rejected, and, if rejected, of the reason why. It contains one of the following possible results: Successful, Invalid request, Invalid room ID, Not authorized node. + +### 9.10 Conference media controls and indications + +MRM provides functions to assist in the management of real-time media used within MRM rooms. These include: the ability to identify an audio or a video source to the receivers, as well as the ability to tell a node sourcing audio or video that its stream(s) are being delivered to other terminals capable of receiving them; the ability to signal privacy on any of the media being used within a room. Service Commands allowing a node to start, subscribe or stop an MRM service. + +The MRM protocol has no involvement in the establishment of real-time streams other than the ability to invite an audio participant to an MRM room. However, MRM provides mechanisms to support the unique identification of a media source within an MRM conference or room. It also provides a channel handle, a unique handle assigned by MRM using the MCS token mechanism. These handles can be mapped, by the MRM top provider and its network elements, onto the physical channels transporting the media, but this is beyond the scope of this Recommendation. + +### 9.10.1 Description of abstract services + +- MRM-Source-Identification – Message originating at a node sourcing audio and/or video to identify that source and the channel it is being transmitted on. +- MRM-On-Air-Indication – Indication to an audio or video source that its stream(s) are being delivered to one or more terminals capable of receiving them. +- MRM-Privacy-Notify – Allows a node to announce to the MRM Room that it is temporarily suspending participation to deal with a local matter. +- MRM-Service-Command – This primitive allows a node to Launch, Activate, Subscribe, or Deactivate an MRM service. + +#### 9.10.1.1 MRM-Source-Identification + +*Protocol link: 10.12* + +This function provides the capability for the origin and content of a real-time stream to be communicated to each recipient node. + +Each node in the conference is uniquely identified by its MRM User ID (or represented by a proxy service). If a node is only capable of originating a single stream of a given media, then its User ID is all that will be needed to uniquely identify it as the originating node for that stream. Where a node is capable of originating more than one stream of a particular media, then this Recommendation supports the unique identification of streams. The MRM database provides the means to map streams to logical channels. Streams may be identified by tags embedded within the streams, or the identification may be implicit based upon a numeric ordering. + +In a multipoint conference, when an MRM-aware node provides a media source to a real-time channel, it is required to send a source identification message to the conference management channel. If an identifier is not received from the node originating the stream, then the default audio + +and/or video streams for that node will be assumed. In this case the MRM top provider will extract a name if available from the GCC conference roster entry for that node and generate the identification message itself. The identification message will allow a source to be associated with the real-time channel that is used to transport it. Where available the source identification information is used to replace the default determination of the source. + +An MRM identification message can be associated with each received stream by the conference manager, or another network element acting on its behalf. It is the conference manager's responsibility to relay the identification onward to correspond to the routing applied to the stream. If any manipulation of a stream takes place, it must generate a new MRM Identification message to correlate with the changes. + +The information will be used to identify to the receiver what is being sent and also from what location the stream originates. For a video stream it may be used to generate a caption for displaying with the image, but this is beyond the scope of this Recommendation. + +Figure 30 shows the sequence of events when using this primitive. Table 27 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-Source-Identification process between a Node Originating Stream and Node(s) Receiving Stream.](b0988cfd9f60f2cd1916e3c2f9cae3da_img.jpg) + +``` + +sequenceDiagram + participant N1 as Node Controller + participant M1 as MRM Provider + participant M2 as MRM Provider + participant N2 as Node Controller + + Note over N1: Node Originating Stream + Note over N2: Node(s) Receiving Stream + + N1->>M1: MRM-Source-Identification request + M1->>M2: + M2->>N2: MRM-Source-Identification indication + +``` + +The diagram illustrates the sequence of events for MRM-Source-Identification. It shows two main sections: 'Node Originating Stream' on the left and 'Node(s) Receiving Stream' on the right. In the originating section, a 'Node Controller' (represented by an oval) sends an 'MRM-Source-Identification request' to an 'MRM Provider' (represented by a vertical line). In the receiving section, an 'MRM Provider' (vertical line) sends an 'MRM-Source-Identification indication' to a 'Node Controller' (oval). A horizontal line connects the two 'MRM Provider' lifelines, indicating a direct transfer of the information. + +Sequence diagram showing the MRM-Source-Identification process between a Node Originating Stream and Node(s) Receiving Stream. + +**Figure 30/T.137 – MRM-Source-Identification – Sequence of primitives** + +**Table 27/T.137 – MRM-Source-Identification Primitive** + +| Parameter | Request | Indication | +|---------------------------|---------|------------| +| Source Handle | M | M(=) | +| Source Channel Identifier | M | M(=) | +| Media Type | M | M(=) | +| Stream Descriptor | O | O(=) | +| Associated Room ID | O | O(=) | +| Reason Code | O | O(=) | + +**Source Handle:** An MRM assigned handle which uniquely identifies the source by taking the node's MRM User ID and appending to it a locally unique ID to distinguish between different sources at the same node. + +**MEDIA Channel Identifier:** The identifier for the channel the stream is being sent on. A dynamic MCS channel used as a unique identifier for the channel. + +**Media Type:** Audio/Video/Other. + +**Stream Descriptor:** Human- readable description of stream content. + +**Associated Room ID:** Identifier for the MRM room to which stream is directed. + +**Reason Code:** This code tells receiving site why image has changed – Mode change, Multipoint Channel Routing Override. + +##### Terminal action + +In order for a terminal to join the Identification service, it must send out its own video or audio identification message. Once this has been received, the node will be included in the service. Whenever the source it provides to the conference changes, it must send a new identification with the source device and identifier string. If the optional fields are not completed, the service will assume the source is the default video and/or audio streams and will use the user name string provided by the terminal's "GCC\_Announce\_Presence" message. + +##### Network element actions + +Each network element/MCU must be able to associate each stream it receives with a stream identifier. When a stream identifier is received for a stream arriving at one of its inputs the MRM provider must store the identifier and whenever a network element/MCU provides a new video source to any of its outgoing ports, it must send an MRM-Source-Identification primitive directed to the node receiving its output. Each network element needs to know the User ID of the terminals or network elements directly connected to its ports. If a connection is to another network element, it must also know the user ID of all other terminals and ports that can be reached via that MCU in order that it can route the messages using their User IDs. Each network element/MCU maintains its own local Stream Identification Register providing it with identifiers for each logical channel that it has as an input. + +#### 9.10.1.2 MRM-Privacy-Notify + +*Protocol link: 10.13.1* + +When a node wishes to temporarily suspend transmission of one of its real-time media streams, the MRM-Privacy-Notify message is sent from that endpoint to the conference management channel and the source removes or mutes its outgoing streams (unless it has asked for this to be done centrally). The conference manager forwards the privacy indication to those endpoints that were receiving the stream; however, it may also interpret the message itself and, for example, replace a video stream with a blue screen with a suitable message to the receiver(s). Likewise, when the privacy mode is cancelled by the endpoint, the procedure is reversed. + +Figure 31 shows the sequence of events when using this primitive. Table 28 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-Privacy-Notify process between an MRM Terminal Node Controller, two MRM Providers, and a Node Controller for all nodes in the room.](4dc0d6f219d7eb8923d60e8cec8cbf0b_img.jpg) + +``` +sequenceDiagram + participant T as MRM Terminal Node Controller + participant P1 as MRM Provider + participant P2 as MRM Provider + participant N as Node Controller (All Nodes in room) + + T->>P1: MRM-Privacy-Notify request + P1->>P2: MRM-Privacy-Notify indication + P2->>N: MRM-Privacy-Notify indication + N-->>P1: MRM-Privacy-Notify confirm + P1-->>T: MRM-Privacy-Notify confirm +``` + +The diagram illustrates the sequence of events for the MRM-Privacy-Notify primitive. It involves four entities: MRM Terminal Node Controller, MRM Provider, MRM Provider, and Node Controller (All Nodes in room). The sequence is as follows: 1. MRM Terminal Node Controller sends an MRM-Privacy-Notify request to the first MRM Provider. 2. The first MRM Provider sends an MRM-Privacy-Notify indication to the second MRM Provider. 3. The second MRM Provider sends an MRM-Privacy-Notify indication to the Node Controller (All Nodes in room). 4. The Node Controller (All Nodes in room) sends an MRM-Privacy-Notify confirm back to the second MRM Provider. 5. The second MRM Provider sends an MRM-Privacy-Notify confirm back to the first MRM Provider. 6. The first MRM Provider sends an MRM-Privacy-Notify confirm back to the MRM Terminal Node Controller. + +Sequence diagram showing the MRM-Privacy-Notify process between an MRM Terminal Node Controller, two MRM Providers, and a Node Controller for all nodes in the room. + +**Figure 31/T.137 – MRM-Privacy-Notify – Sequence of primitives** + +**Table 28/T.137 – MRM-Privacy-Notify Primitive** + +| Parameter | Request | Indication | Confirm | +|-------------------------|---------|------------|---------| +| Source Handle | M | M(=) | M(=) | +| Media Channel ID | M | M(=) | M(=) | +| Room ID | O | O(=) | O(=) | +| Invoke Privacy Remotely | M | M(=) | M(=) | +| Privacy Status | M | M(=) | M(=) | + +**Source Handle:** An MRM assigned handle which uniquely identifies the source by taking the node's MRM User ID and appending to it a locally unique ID to distinguish between different sources at the same node. + +**Media Channel ID:** The identifier for the channel the stream is being sent on. A dynamic MCS channel used as a unique identifier for the channel. + +**Media Type:** Audio/Video/Other. + +**Room ID:** The ID for the room in which the privacy indication is relevant. + +**Invoke Privacy Remotely:** Request for network to invoke privacy on behalf of requester. + +**Privacy Status:** On/Off. + +#### 9.10.1.3 On-Air-Indication service + +*Protocol link: 10.13* + +The On-Air-Indication service is used in a multipoint conference to provide an indication back to a node originating a stream. Whenever a stream is routed to a terminal capable of interpreting it, then the source providing that stream is deemed to be On-Air. Only the conference manager or network elements acting in conjunction with the conference manager may generate the On-Air-Indication primitive. + +The MRM Provider at each network element is responsible for maintaining a record of the On-Air status of each of its input channels. When the node controller at a network element makes a change to its outputs, or it receives an On-Air indication, and this results in a change of On-Air status of one of its inputs, then that network element should generate an MRM-On-Air-Indication request directed at node providing that stream to it. + +When a source is routed by network elements to one or more receivers, then this event will result in the source node receiving an MRM-On-Air-Indication indication with the On-Air status flag set to TRUE. Only when the last receiver is removed will the sourcing node get another MRM-On-Air-Indication indication with the On-Air status flag set to FALSE. + +Figures 32 and 33 show the sequence of events when using this primitive. Table 29 shows the parameters and types of this primitives. + +![Sequence diagram showing the flow of MRM-Service-On-Air-Indication request from Node Controller to MRM Provider, and then MRM-Service-On-Air-Indication indication from MRM Provider to Stream Source Node Controller.](e2dad48ec062e71202459a9ab82261e4_img.jpg) + +``` + +sequenceDiagram + participant NC1 as Node Controller + participant MP1 as MRM Provider + participant MP2 as MRM Provider + participant NC2 as Stream Source Node Controller + NC1->>MP1: MRM-Service-On-Air-Indication request + MP1->>MP2: + MP2->>NC2: MRM-Service-On-Air-Indication indication + +``` + +T1607660-99 + +Sequence diagram showing the flow of MRM-Service-On-Air-Indication request from Node Controller to MRM Provider, and then MRM-Service-On-Air-Indication indication from MRM Provider to Stream Source Node Controller. + +**Figure 32/T.137 – MRM-On-Air-Indication – Sequence of primitives** + +![Sequence diagram showing the flow of MRM-Service-On-Air-Indication indication from MRM Provider to Stream Source Node Controller.](8ab30dbff406204a68c59ae7c1b77413_img.jpg) + +``` + +sequenceDiagram + participant MP as MRM Provider + participant NC as Stream Source Node Controller + MP->>NC: MRM-Service-On-Air-Indication indication + +``` + +T1607670-99 + +Sequence diagram showing the flow of MRM-Service-On-Air-Indication indication from MRM Provider to Stream Source Node Controller. + +**Figure 33/T.137 – Service-initiated MRM-On-Air-Indication – Sequence of primitives** + +**Table 29/T.137 – MRM-On-Air-Indication primitive** + +| Parameter | Request | Indication | +|--------------------------|---------|------------| +| Source Handle | M | M(=) | +| Media Channel Identifier | M | M(=) | +| Media Type | M | M(=) | +| Room ID | O | O(=) | +| On-Air Status Flag | M | M(=) | + +**Source Handle:** An MRM-assigned handle which uniquely identifies the source by taking the nodes MRM User ID and appending to it a locally unique ID to distinguish between different sources at the same node. + +**Media Channel Identifier:** The identifier for the channel the stream is being sent on. A dynamic MCS channel used as a unique identifier for the channel. + +**Media Type:** Audio/Video/Other. + +**Room ID:** Identifier for MRM room to which stream is directed. + +**On Air Status Flag:** TRUE/FALSE. + +#### 9.10.1.4 MRM-Service-Command + +*Protocol link: 10.14* + +The MRM-Service-Command request primitive enables a node controller at an MRM terminal or network element to send a service-related command to the conference manager, or for the conference manager to send a service-related command to other network elements participating in the delivery of the MRM conference. Participants and observers may, subject to their role privileges, subscribe to a service specified as offered in the MRM roster. Nodes shall subscribe to a service that is specified as required in the MRM roster. Nodes may also un-subscribe to a service that they voluntarily joined to, but no longer require. + +The conference manager launches a service in response to framework requirement using the Launch form of the Service Command. + +Figure 34 shows the sequence of events when using this primitive. Table 30 shows the parameters and types of this primitives. + +![Sequence diagram for MRM-Service-Command showing interactions between Node Controller, MRM Provider, MRM Top Provider, and MRM Providers on Conference-Management channel.](17f0cf80b9c38adb460d4ca836960da7_img.jpg) + +``` +sequenceDiagram + participant NC1 as Node Controller + participant MP as MRM Provider + participant MTP as MRM Top Provider + participant NC2 as Node Controller + participant MCP as MRM Providers on Conference-Management channel + participant NC3 as Node Controller + + NC1->>MP: MRM-Service-Command request + MP->>MTP: + MTP->>NC2: MRM-Service-Command indication + MTP-->>MP: + MP-->>NC1: MRM-Service-Command confirm + MCP->>NC3: MRM-Service-Command indication +``` + +The diagram illustrates the sequence of events for the MRM-Service-Command primitive. It involves four main entities: Node Controller (left), MRM Provider, MRM Top Provider, and Node Controller (right). The sequence is as follows: 1. The left Node Controller sends an 'MRM-Service-Command request' to the MRM Provider. 2. The MRM Provider sends a message to the MRM Top Provider. 3. The MRM Top Provider sends an 'MRM-Service-Command indication' to the right Node Controller. 4. The MRM Top Provider sends a return message to the MRM Provider. 5. The MRM Provider sends an 'MRM-Service-Command confirm' back to the left Node Controller. Below this, a separate interaction shows 'MRM Providers on Conference-Management channel' sending an 'MRM-Service-Command indication' to a 'Node Controller'. + +Sequence diagram for MRM-Service-Command showing interactions between Node Controller, MRM Provider, MRM Top Provider, and MRM Providers on Conference-Management channel. + +T1607680-99 + +**Figure 34/T.137 – MRM-Service-Command – Sequence of primitives** + +**Table 30/T.137 – MRM-Service-Command primitive** + +| Parameter | Request | Indication | Confirm | +|--------------------------------|---------|------------|---------| +| Request Handle | C | M | M(=) | +| Requesting Node | | M | | +| MRM Room ID | C | M | | +| MRM Service Command | C | M | | +| Service Name ID | C | M | | +| Service Mode | O | O | | +| Participation Options | O | M | | +| Participant and Resources List | O | O | | +| Include Anonymous Nodes – Flag | O | O | | +| Result | | | M | + +**Request Handle:** Locally unique number to allow the requesting node to match responses. + +**Requesting Node:** MRM User ID of the node issuing a service command. + +**MRM Room ID:** Identifier for the MRM room in which the service command is to take effect. + +**Service Command ID:** Choice of: + +- *Launch* – Issued by conference manager to initiate network-based service functionality. +- *Subscribe* – Participants subscribe to an active service that they are not automatically subscribed to. +- *Unsubscribe* – Participants leave an active service that they no longer wish to be subscribed to. + +**Service Name ID:** The MRM Service ID Key which the requesting node wishes to issue the command for. + +**Service Mode:** This parameter is application specific. + +**Participation Options:** This parameter allows the conference manager to specify a room-wide requirement. + +Consists of the following choices: + +- All participants at "service capable" nodes may join. +- All participants at "service capable" nodes shall join. +- Participation is specified node by node in the Participants and Resources List. + +##### **Participants and Resources List:** + +Choice of: + +- *Node by node specification list* – List of participating terminal Node IDs with requirements for number and type of media channel, together with the logical channel specification. +- *Or a room requirement specification* which will be applicable to all nodes which participate: + - *Source Nodes:* Optional list of nodes to receive from service. + - *Number of source channels per node:* Optional number of sources per terminal node. + - *Receiving Nodes:* Optional list of nodes to receive from service. + - *Number of receive channels per node:* Optional number of receiving channels per terminal node. + +**Include Anonymous Nodes – Flag:** Flag indicating anonymous nodes should be included as receivers. + +**Service Mode:** The service mode is specified as a key; the default operation of the service will be assumed if not specified. The integer values in the range 1-255 are available for assignment within the individual services as required. + +**Import Source Identifier:** This parameter allows a source from another room or a participating server to be included in the service. Each service that makes use of this facility describes how it is to be used. + +**Include Anonymous Nodes:** Flag to Service if anonymous nodes can participate; this parameter is effectively service specific as it depends on the nature of the service as if it is appropriate to include anonymous nodes and if there are any participating. + +**Result:** Indicates whether the request was accepted or rejected. It contains one of the following results: Successful, Service not available, Not authorized node, Invalid room ID. + +### **9.11 MRM media services** + +MRM provides the means to define services supporting media use within rooms. It allows media to be integrated seamlessly into an MRM room. Currently, only Audio Bridging is standardized, providing a standardized solution to audiographic conferencing8. MRM also supports the definition of user-defined services. + +### **9.11.1 Service events** + +The following service events require action from the MRM top provider or the network element acting on its behalf for a given service. Action for each of these events must be specified with the service definition. + +#### **Launching a media service** + +The MRM top provider is the only node within the MRM conference that can launch an MRM media service. The launch results from a framework requirement or as a result of a launch being requested by the convenor or chair for the room that the service is to be launched in. + +##### **Subscribing to a media service** + +If the MRM roster advertises an active MRM service where the subscription is not automatic for capable nodes, then a node has the ability to subscribe to the service using the subscribe service command. + +##### **Unsubscribing from a media service** + +A node that has chosen to subscribe to a service may also choose to unsubscribe from that service. + +#### **Entering an MRM room** + +When a node enters an MRM room, it becomes subject to the service regime that is in operation for that room. The participant options for the service specify what the requirement is for active services. + +#### **Leaving an MRM room** + +When a node leaves a room, any services that the node has subscribed to or has been subscribed to must be unsubscribed; this is the responsibility of the MRM top provider. + +--- + +8 Other standardized services are expected in future revisions of this Recommendation. + +### 9.11.2 Audio Bridging Service + +The Audio Bridging service, like all MRM functionality, is room based and for each MRM room within a conference there is the potential for a separate Audio Bridge service to operate. The service specifies controls and indications between participants and the service. Inter-bridge control and signalling is currently beyond the scope of this Recommendation. + +#### Default operation + +When a terminal node enrolls its MRM application it specifies its audio capabilities. When a node enters an MRM room the MRM roster is sent to it; this roster indicates if the Audio Bridging Service is required. Any participant node that is audio capable will automatically be included in a required Audio Bridging Service. + +The Audio Bridging service by default mixes the default stream from each audio-capable node in the room participating in the service. The service provides an audio output for each participating node which is a mix of the inputs; the algorithms for mixing are beyond the scope of this Recommendation. Service reporting is enabled and service participants in the room will be notified by service reports each time a supported event such as New Speaker detection is recorded by the service. + +#### 9.11.2.1 Chair-controlled rooms + +In the absence of framework requirements, a chair role may be requested and assigned within a room as required. Once a chair has been assigned, it has the option to launch floor control as required. + +Once floor control is launched, other MRM services are notified by the MRM top provider. On receiving an indication of Floor Control becoming active, the Audio Bridging Service changes its operational mode to Floor controlled. The framework determines the operation, but by default all audio inputs to all mixers are muted except those of the chair and of any participating operator. Participants may request to speak: the floor control service will direct these requests to the chair who can grant or refuse them or put them in a pending queue. Granted requests and relinquish floor requests from the chair are accompanied by a Set-Audio-Mix request being sent to the service; this request configures the Room mixers to what has been specified by the chair. + +Where there is a defined framework, this may call for the service to be launched automatically as soon as the chair joins the room; in either case, the operation is the same. + +### 9.12 Audio Mixer management + +### 9.12.1 Description of abstract services + +- MRM-Audio-Mixer-Set – This primitive is used to configure the audio mixer. +- MRM-AudioMix-Report – When enabled, this primitive provides status reports from the audio mixer. +- MRM-Invite-Audio-Only-Node – Allows an MRM node to issue an Invite that will cause an audio phone call to be made. +- MRM-Eject-Audio-Only-Node – Allows an MRM node to issue an Eject that will cause the audio line to be disconnected. +- MRM-Call-Status – Provides feedback to the initiator of an Invite requiring a dialled connection and is used to provide status information to the initiator of an MRM-Invite-Audio-Only-Node request. + +#### 9.12.1.1 MRM-Audio-Mixer-Set + +*Protocol link: 10.15* + +The MRM-Audio-Mixer-Set primitive provides the means for an authorized node to specify which audio streams are to be included in the audio mix for an MRM room. These requests are sent to the service management channel, where they are validated. If the requester is authorized to control the mixer the service manager constructs and issues appropriate out-of-band commands to control the mixer or mixers. + +It may be the case that multiple network elements with separate bridges cooperate to deliver the mixing service. No explicit control and indications are specified in this MRM Recommendation version; however, where in-band signalling is needed, the Service Command primitives can be extended with user-defined parameters to address this need. + +The requester may specify the required Bridge settings in a number of ways: A complete list of streams to be mixed can be specified, or only a list of streams to add to the current mix. A list of streams to be removed can be specified. Removing streams will free mixer resources. The mute and enable options should be used to address temporary changes, as is the case with floor control. + +Figure 35 shows the sequence of events when using this primitive. Table 31 shows the parameters and types of this primitive. + +![Sequence diagram showing the MRM-Audio-Mixer-Set primitive flow between a Requesting Node, MRM Providers, and a Service Manager.](4847c98185bc52e8786b78738bc52b45_img.jpg) + +``` + +sequenceDiagram + participant RN as Requesting Node +Node Controller + participant MP1 as MRM Provider + participant MP2 as MRM Provider + participant SM as Service Manager +Node Controller + + RN->>MP1: MRM-Audio-Mixer-Set request + MP1->>MP2: + MP2->>SM: MRM-Audio-Mixer-Set indication + SM-->>MP1: MRM-Audio-Mixer-Set confirm + MP1-->>RN: + + Note over MP1, MP2: MRM Providers on +Conference-Management channel + Note over MP2, SM: Node Controller + MP2->>SM: MRM-Audio-Mixer-Set indication + +``` + +The diagram illustrates the sequence of events for the MRM-Audio-Mixer-Set primitive. It involves three main entities: the Requesting Node (Node Controller), MRM Providers, and the Service Manager (Node Controller). The Requesting Node sends an 'MRM-Audio-Mixer-Set request' to the first MRM Provider. This request is then passed to the second MRM Provider, which sends an 'MRM-Audio-Mixer-Set indication' to the Service Manager. The Service Manager responds with an 'MRM-Audio-Mixer-Set confirm' to the second MRM Provider, which then returns the response to the Requesting Node. A separate section shows the MRM Providers on the Conference-Management channel sending an 'MRM-Audio-Mixer-Set indication' to the Service Manager's Node Controller. + +Sequence diagram showing the MRM-Audio-Mixer-Set primitive flow between a Requesting Node, MRM Providers, and a Service Manager. + +**Figure 35/T.137 – MRM-Audio-Mixer-Set – Sequence of primitives** + +**Table 31/T.137 – MRM-Audio-Mixer-Set – Types of primitives and their parameters** + +| Parameter | Request | Indication | Confirm | +|------------------------------|---------|------------|---------| +| Request Handle | M | | M(=) | +| Originating Node MRM User ID | | M(=) | | +| MRM Room Identifier | M | M(=) | | +| Audio Mixing Mode | O | O(=) | | +| Add Node-Stream (List) | O | O(=) | | +| Remove Node-Stream List | O | O(=) | | +| Enable Node-Stream (List) | O | O(=) | | +| Mute Node-Stream (List) | O | O(=) | | +| Include Node Stream (List) | O | O(=) | | +| Request Audio Level Adjust | O | O(=) | | +| Result | | | M | + +**Originating Node MRM User ID:** Requesting Node MRM User ID. + +**MRM Room Identifier:** The identifier for the MRM room. + +**Mode:** Manual/Default (distributed)/Centralized. + +**Add Node-Stream (List):** List of streams to be added to an existing mix. + +**Remove Node-Stream (List):** List of streams to be removed from an existing mix. + +**Enable Node-Stream (List):** A list of streams to be enabled, i.e. to have a previous mute removed. + +**Mute Node-Stream (List):** A list of streams to be muted at the mixer. + +**Include Node Stream (List):** A complete list of all the streams to be included in the mix. + +**Remove Node-Stream (List):** A complete list of streams to be removed from the mix. + +**Request Audio Level Adjust:** Where this feature is available and permitted, it allows the requester to adjust the level of the mixer output delivered to it. By specifying another node, this command can be used to adjust the input to the requester's mix. The convenor or chair may adjust the levels for the entire Room. + +Node MRM User ID + Device ID (if not default) – Optional; when not specified, mixer output will be adjusted. + +Increase/Decrease 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, 150%, 200%. + +Flag Applies to all nodes in room – Only convenor or chair can set this flag. + +**Result:** Request authorized, Request not authorized, No other network elements. + +#### 9.12.1.2 MRM-AudioMix-Report + +*Protocol link: 10.15.3* + +When the Audio Mixing service is configured with its reporting mechanism enabled, the MRM-AudioMix-Report primitive may be issued by the MRM service manager at the network element which is hosting the Audio Bridging service to nodes participating in the service. + +A report is triggered by a service event such as "New speaker detected". Events in the Audio Bridging service may result from a participant speaking, an algorithm operating, or an MRM-Audio-Mixer-Set command; in all cases where announcements are enabled, a change in the audio mix + +results in a new MRM-AudioMix-Report, which includes the node it has nominated to be the new speaker; it may also send its previous speaker assignment and a list of streams included in its mixer output. + +Figure 36 shows the sequence of events when using this primitive. Table 32 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-AudioMix-Report sequence of primitives. It involves four lifelines: Node Controller (left), Service Manager (top), MRM Provider (middle), and Node Controller (right). The sequence starts with an 'MRM-AudioMix-Report request' from the left Node Controller to the MRM Provider. This is followed by an 'MRM-AudioMix-Report indication' from the MRM Provider to the right Node Controller. The Service Manager lifeline is present but has no messages.](b1784a5cbeeb3d9fb9e60b333019c721_img.jpg) + +``` + +sequenceDiagram + participant NC1 as Node Controller + participant SM as Service Manager + participant MP1 as MRM Provider + participant MP2 as MRM Provider + participant NC2 as Node Controller + + NC1->>MP1: MRM-AudioMix-Report request + MP1->>MP2: + MP2->>NC2: MRM-AudioMix-Report indication + +``` + +Sequence diagram showing the MRM-AudioMix-Report sequence of primitives. It involves four lifelines: Node Controller (left), Service Manager (top), MRM Provider (middle), and Node Controller (right). The sequence starts with an 'MRM-AudioMix-Report request' from the left Node Controller to the MRM Provider. This is followed by an 'MRM-AudioMix-Report indication' from the MRM Provider to the right Node Controller. The Service Manager lifeline is present but has no messages. + +**Figure 36/T.137 – MRM-AudioMix-Report – Sequence of primitives** + +**Table 32/T.137 – MRM-AudioMix-Report – Types of primitives and their parameters** + +| Parameter | Request | Indication | +|---------------------------------------|---------|------------| +| MRM User ID | M | M= | +| MRM Room Identifier | M | M= | +| New Speaker MRM User ID | M | M= | +| New Speaker Microphone Device ID | O | O= | +| Previous Speaker MRM User ID | M | M= | +| Previous Speaker Microphone Device ID | O | O(=) | +| List of Nodes included in mix | O | O(=) | +| List of Active Speakers | O | O(=) | + +**MRM User ID:** Detecting node MRM ID. + +**MRM Room Identifier:** The identifier for the MRM room. + +**New Speaker MRM User ID:** The MRM User ID of the node nominated locally as new speaker. + +**New Speaker Microphone Device ID:** Where a terminal node has a number of participants with separate microphones and logical channels, these can be distinguished from the default audio stream for that node. + +**Previous Speaker MRM User ID:** The MRM User ID of the node nominated locally as previous speaker. + +**Previous Speaker Microphone Device ID:** Where a terminal node has a number of participants with separate microphones and logical channels these can be distinguished from the default audio stream for that node. + +**List of Nodes included in mix:** List of Node User IDs, Mic IDs, Channel Ids identifying all streams being included in mix. + +**List of Active Speakers:** List of all Node User IDs, Mic IDs, Channel IDs identifying as contributing to the output stream. + +#### 9.12.1.3 Audio Bridging service – Events + +The MRM framework determines if the Audio Bridging service is available to the MRM conference. The MRM default framework does not include the service because it makes no assumptions about the requirement for audio. In services where audio is part of the baseline a new framework profile should be created and set to be the new default. When a framework is loaded that specifies a requirement for this service, there is a default behaviour defined. This specifies that the service will be launched and active and media capable nodes are required to subscribe to it. Loading a framework with a modified service requirement or participation requirement will modify this default behaviour. The MRM top provider or a network element acting on its behalf is responsible for launching, activating and de-activating services based upon framework requirements and also for dealing with service operation when a node enters or leaves an MRM room. + +#### 9.12.1.4 MRM-Invite-Audio-Only-Node + +*Protocol link: 10.15.4* + +The MRM-Invite-Audio-Only-Node primitive is used by suitably privileged participants to request that a participant be invited to join the audio part of the conference. This would be achieved by the MRM top provider issuing a dial-out request to the audio bridge (but this is beyond the scope of this Recommendation). + +Figure 37 shows the sequence of events when using this primitive. Table 33 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-Invite-Audio-Only-Node process between four entities: Node Controller, MRM Provider, MRM Top Provider, and Conference Manager Node Controller.](afd9ce64c136f2090b978ea5f3ef9d8d_img.jpg) + +``` +sequenceDiagram + participant NC as Node Controller + participant MP as MRM Provider + participant MTP as MRM Top Provider + participant CMNC as Conference Manager Node Controller + + NC->>MP: MRM-Invite-Audio-Only-Node request + MP->>MTP: + MTP->>CMNC: MRM-Invite-Audio-Only-Node indication + CMNC->>MTP: + MTP->>MP: MRM-Invite-Audio-Only-Node response + MP->>NC: MRM-Invite-Audio-Only-Node confirm +``` + +The diagram illustrates the sequence of events for the MRM-Invite-Audio-Only-Node primitive. It involves four entities: Node Controller, MRM Provider, MRM Top Provider, and Conference Manager Node Controller. The sequence is as follows: 1. Node Controller sends an 'MRM-Invite-Audio-Only-Node request' to MRM Provider. 2. MRM Provider sends an empty message to MRM Top Provider. 3. MRM Top Provider sends an 'MRM-Invite-Audio-Only-Node indication' to Conference Manager Node Controller. 4. Conference Manager Node Controller sends an empty message back to MRM Top Provider. 5. MRM Top Provider sends an 'MRM-Invite-Audio-Only-Node response' to MRM Provider. 6. MRM Provider sends an 'MRM-Invite-Audio-Only-Node confirm' to Node Controller. A reference 'T1607710-99' is noted at the bottom right of the diagram. + +Sequence diagram showing the MRM-Invite-Audio-Only-Node process between four entities: Node Controller, MRM Provider, MRM Top Provider, and Conference Manager Node Controller. + +**Figure 37/T.137 – MRM-Invite-Audio-Only-Node – Sequence of primitives** + +**Table 33/T.137 – MRM-Invite-Audio-Only-Node** + +| Parameter | Request | Indication | Response | Confirm | +|----------------------------|---------|------------|----------|---------| +| Request Handle | M | | | M(=) | +| DestinationRoom ID Handle | M | M(=) | | | +| Node Communication Address | M | M | | | +| NonT120node UserID | | | M | M(=) | +| Room Access Parameter | C | C(=) | | | +| Reason for Invitation | O | O(=) | | | +| Entry Method | O | O(=) | | | +| Result | | | M | M | + +**Request Handle:** Locally unique number to allow the requesting node to match responses. + +**DestinationRoom ID handle:** The Room ID for the virtual meeting space that the node is being invited to. + +**Node Communication Address:** Choice of Phone Number, IP Address. + +**Room Access Parameter:** For a Controlled access room, an entry ticket will be needed. This will be either: + +    Password: TBD + +**Reason For Invitation:** Optional string giving reason for invitation. + +**Entry Method:** Choice of: Direct, By side conference. + +**Result:** Indicates whether the request was successful. It contains one of the following results: Successful, Invalid Room ID, Not authorized node. + +#### 9.12.1.5 MRM-Eject-Audio-Only-Node + +*Protocol link: 10.15.4* + +The MRM-Eject-Audio-Only-Node primitive is used by suitably privileged participants to request that a participant be removed from the audio part of the conference. This would be achieved by the MRM top provider issuing a call terminate request to the audio bridge (but this is beyond the scope of this Recommendation). + +Figure 38 shows the sequence of events when using this primitive. Table 34 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-Eject-Audio-Only-Node sequence of primitives between four entities: Node Controller, MRM Provider, MRM Top Provider, and Conference Manager Node Controller.](05da2a3257316bbf6f448a830dc0380a_img.jpg) + +``` + +sequenceDiagram + participant NC as Node Controller + participant MP as MRM Provider + participant MTP as MRM Top Provider + participant CMNC as Conference Manager Node Controller + + NC->>MP: MRM-Eject-Audio-Only-Node request + MP->>MTP: + MTP->>CMNC: MRM-Eject-Audio-Only-Node indication + CMNC->>MTP: MRM-Eject-Audio-Only-Node response + MTP->>MP: + MP->>NC: MRM-Eject-Audio-Only-Node confirm + +``` + +The diagram illustrates the sequence of events for the MRM-Eject-Audio-Only-Node primitive. It involves four entities: Node Controller, MRM Provider, MRM Top Provider, and Conference Manager Node Controller. The sequence is as follows: 1. Node Controller sends an 'MRM-Eject-Audio-Only-Node request' to MRM Provider. 2. MRM Provider sends an empty message to MRM Top Provider. 3. MRM Top Provider sends an 'MRM-Eject-Audio-Only-Node indication' to Conference Manager Node Controller. 4. Conference Manager Node Controller sends an 'MRM-Eject-Audio-Only-Node response' to MRM Top Provider. 5. MRM Top Provider sends an empty message to MRM Provider. 6. MRM Provider sends an 'MRM-Eject-Audio-Only-Node confirm' to Node Controller. A reference 'T1607720-99' is noted at the bottom right. + +Sequence diagram showing the MRM-Eject-Audio-Only-Node sequence of primitives between four entities: Node Controller, MRM Provider, MRM Top Provider, and Conference Manager Node Controller. + +**Figure 38/T.137 – MRM-Eject-Audio-Only-Node – Sequence of primitives** + +**Table 34/T.137 – MRM-Eject-Audio-Only-Node** + +| Parameters | Request | Indication | Response | Confirm | +|--------------------|---------|------------|----------|---------| +| Request Handle | M | | | M(=) | +| Room ID Handle | M | M(=) | | | +| NonT120node UserID | M | M(=) | | | +| Result | | | M | M | + +**Request Handle:** Locally unique number to allow the requesting node to match responses. + +**Room ID Handle:** The Room ID for the room that the node is participating in. + +**NonT120 UserID:** User ID assigned to audio only node by the MRM top provider. + +**Result:** Indicates whether the request was successful. It contains one of the following results: Successful, Invalid Room ID, Not authorized node. + +#### 9.12.1.6 MRM-Call-Status + +*Protocol link: 10.15.4* + +The MRM-Call-Status primitive is used by MRM top provider to signal back information on the progress of a dial-out connection. + +Figure 39 shows the sequence of events when using this primitive. Table 35 shows the parameters and types of this primitives. + +![Sequence diagram showing the MRM-Call-Status primitive flow. A Node Controller sends an MRM-Call-Status request to an MRM Top Provider. The MRM Top Provider then sends an MRM-Call-Status indication to a Call Initiator Node Controller.](7b18671bc31881a5c474883bf6a300fd_img.jpg) + +``` + +sequenceDiagram + participant NC1 as Node Controller + participant MTP1 as MRM Top Provider + participant MTP2 as MRM Top Provider + participant NIC as Call Initiator Node Controller + + NC1->>MTP1: MRM-Call-Status request + MTP1->>MTP2: + MTP2->>NIC: MRM-Call-Status indication + +``` + +T1607730-99 + +Sequence diagram showing the MRM-Call-Status primitive flow. A Node Controller sends an MRM-Call-Status request to an MRM Top Provider. The MRM Top Provider then sends an MRM-Call-Status indication to a Call Initiator Node Controller. + +**Figure 39/T.137 – MRM-Call-Status – Sequence of primitives** + +**Table 35/T.137 – MRM-Call-Status** + +| Parameter | Request | Indication | +|----------------------------|---------|------------| +| Room ID Handle | M | M(=) | +| NonT120node UserID | M | M(=) | +| Node Communication Address | M | M(=) | +| Status | M | M(=) | + +**Room ID Handle:** The Room ID for the room that the node is participating in. + +**NonT120 UserID:** User ID assigned to audio only node by the MRM Top Provider. + +**Node Communication Address:** Choice of Phone Number, IP Address. + +**Status:** Dialling, Ringing, Engaged, NU, NoReply, Answered, Mixed. + +# **10 MRM protocol definition** + +## **10.1 MRM node types** + +The MRM protocol supports two node types: Terminals and network elements. Terminals are effectively clients – users of the protocol. MRM also makes further distinctions between clients. A client may be either an observer or a participant. Network elements are management nodes that manage or contribute towards the management and/or delivery of the conference. For each of these categories the MRM initialization and operational procedure may differ. An MRM conference requires at least one node to participate in a management capacity. For this reason terminal-only nodes cannot launch MRM independently of network elements. + +## **10.2 Launching MRM** + +The requirement for MRM at a Network Element Node Controller is signalled to its MRM Provider using the MRM-Service-Command primitive with the command set to "Launch". This primitive contains a flag that tell the MRM provider if it should compete for the MRM top provider role. If this flag is set, the MRM provider should store the Load-New-Framework Flag and follow the procedures defined in 10.3. + +## **10.3 Determining the MRM top provider** + +The node controller at the MRM top provider takes on the role of conference manager and is responsible for initializing and running the MRM conference. This top provider role is only open to nodes that participate in the conference as network elements. The principle use of MRM is expected to be in support of managed conferencing services, where the allocation of the MRM top provider role will often be known in advance, or it may even be hardwired into a system. In these cases the nominated node should grab the MRM-Top-Provider-Token; an MCS token assigned to represent the MRM top provider. + +When the MRM top provider role has not been pre-assigned and the current GCC top provider has not indicated that it is MRM capable, then network elements may compete for it by attempting to grab the MRM-Top-Provider-Token. The node that succeeds in grabbing it is then nominated to become the MRM top provider. + +The holder of the MRM-Top-Provider-Token shall join the MRM-Conference-Management-Channel. + +## **10.4 MRM initialization and start-up** + +It is the task of the MRM top provider to initiate the MRM conference. Once a node has taken on the MRM top provider role it checks the "Load-New-Framework" flag provided in the earlier MRM-Launch request primitive. If it is set to TRUE, the MRM top provider must wait for an MRM-Framework-Load request to occur, or another MRM-Launch with the flag set to FALSE, before it can proceed. Once the new framework is loaded or the provider is given permission to proceed, it will enrol its MRM application with GCC, following the MRM Session Protocol Initialization sequence for a network element specified in Figure 40. This involvement is predefined as enrolling it as Inactive and obtaining an MCS User ID, the MRM ARM then joins the appropriate MRM channels for its MRM node type. The MRM top provider joins the MRM-Conference-Management-Channel. MRM requires only a single static session for operation of the MRM protocol. This session is initialized locally by the MRM top provider. + +![Sequence diagram showing the MRM session protocol initiation sequence between Local MRM APE, Local GCC Provider, and Local MCS Provider.](e8f5117fb031f413a836525061addd61_img.jpg) + +``` + +sequenceDiagram + participant LMRMAPE as Local MRM APE + participant LGCC as Local GCC Provider + participant LMCS as Local MCS Provider + + LMRMAPE->>LGCC: GCC-Permission-To-Enrol.ind + LGCC->>LMCS: MCS-ATTACH-USER.req + LMCS->>LMRMAPE: MCS-ATTACH-USER.con +[MRM User ID = unique new] + LMRMAPE->>LMCS: MCS-CHANNEL-JOIN.req +[Channel ID = MRM User ID] + LMCS->>LMRMAPE: MCS-CHANNEL-JOIN.con + LMRMAPE->>LMCS: MCS-CHANNEL-JOIN.req +[Channel ID = MRM-CHANNEL-1] + LMCS->>LMRMAPE: MCS-CHANNEL-JOIN.con + LMRMAPE->>LMCS: MCS-CHANNEL-JOIN.req +[Channel ID = MRM-CHANNEL-2] + LMCS->>LMRMAPE: MCS-CHANNEL-JOIN.con + LMRMAPE->>LGCC: GCC-Application-Enrol.req +[Active, Session ID] + LGCC->>LMRMAPE: GCC-Application-Enrol.con + LMRMAPE->>LGCC: GCC-Application-Roster-Report.ind + LGCC->>LMRMAPE: GCC-Application-Roster-Report.ind + +``` + +**Operation** + +- Enrol inactive** + - Obtain MRM User ID +- Join MRM channels** + - Network Elements join the MRM-Conference-Management-Channel + - Terminals join the MRM-Conference-Communication-channel +- Enrol active** + +T1607740-99 + +Sequence diagram showing the MRM session protocol initiation sequence between Local MRM APE, Local GCC Provider, and Local MCS Provider. + +**Figure 40/T.137 – MRM session protocol initiation sequence** + +The MRM top provider has the task of executing the MRM framework requirement. It uses the MRM framework that it holds in its database, which will be the default or the default modified by a "convenor" loaded framework. First, it looks at the pre-defined room list and creates the specified rooms following the room creation procedures specified in 10.8.1. It looks at the service requirements for that room and launches and activates services as specified by the framework. Each service specifies its own operational procedure for events such as Launch and Subscription. + +Once the MRM top provider is enrolled active within the conference, it appears in the GCC application roster. Once the other nodes see the MRM roster entry, they may then proceed to enrol by following the same Session Protocol Initialization sequence for their node type. + +All network elements may join the MRM-Conference-Management-Channel9. This channel is used by terminals to communicate with the MRM top provider, and it also allows communication between the network elements when needed to support management of the conference and services. Terminals join the MRM-Conference-Client-Channel; once joined, they are effectively in the Lobby of the MRM Conference. The MRM top provider sends a RosterReportIndication directly to them on their MRM User ID channel at the highest data priority. This roster report contains conference- wide + +9 This allows the possibility of other network elements shadowing the MRM Top Provider and provide a backup capability; however, this is beyond the scope of this Recommendation. + +information pertaining to the MRM conference and includes a list of available rooms. Terminals may use the conference roster information to discover the room they wish to join or they may already have out-of-band information such as a room key that allows the MRM top provider to place them directly in the appropriate room. In either case a terminal wishing to Enter an MRM room issues an MRM-Room-Enter request, either providing a room key or the MRM Room ID; if it provides a Room ID it may also specify if it wishes to participate as an observer or as a participant. The resulting RoomEnterRequest PDU is sent to the MRM top provider on the MRM-Top-Provider-Channel and the Room Enter protocol procedures are followed. If the node is permitted to enter, it joins the appropriate room communications channel and sends a RoomReadyIndication to the MRM top provider. The RoomReadyIndication is the trigger for the MRM top provider to send the MRM room roster, which is sent to the node on its User ID channel at the highest data priority. Subsequent roster updates are sent as deltas of the original roster reports. These are sent on the appropriate broadcast channel for the conference or room, as specified in the roster update procedures. + +See Tables 36 and 37. + +**Table 36/T.137 – Parameters for GCC-Application-Enrol request** + +| Parameter | Contents | +|----------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------| +| Conference ID | Provided by GCC-Application-Permission-To-Enrol indication | +| Session Key | {itu recommendation t 130 version(0) 1} and MRM-SESSION-ID (static) | +| Application User ID | Provided by MCS-Attach-User confirm | +| Active/Inactive | All nodes initially enrol inactive until they obtain their MRM User ID (assigned by MCS) | +| Conducting Operation Flag | This flag must not be set | +| Start-Up Channel | Static as specified in T.120:
Network Elements join: MRM-Conference-Management-Channel
Terminals join the MRM-Conference-Communication-Channel | +| Non-Collapsing Capabilities List | NodeType Flag: Terminal=TRUE; Network Element=FALSE
ParticipationLevel Flag: Participant=TRUE; Observer=FALSE | +| Application Capability List | See Table below; omitted if Active/Inactive flag is set to Inactive | +| Enrol/Un-enrol | ENROL | + +**Table 37/T.137 – MRM ApplicationCapability List – Parameters for +GCC-Application-Enrol request** + +| Parameter | Parameter type | Contents For Terminal | Contents For Network Element | +|----------------------------------|----------------|------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------| +| List of Media Services Supported | Logical | Set of Choice:
PSTN-Audio
H323-Audio
H324-Audio
H323-Video | Set of Choice:
PSTN-Audio
H323-Audio
H324-Audio
H323-Video
Audio mixing
Video Switching
Video Streaming
Shadow TopProvider | + +## 10.5 General Operation + +All MRM PDUs are sent by the MRM provider issuing an MCS-Send-Data request with the MRM PDU in the data field. The MCS-Send-Data pPrimitive contains the initiator's User ID, the destination Channel ID and a Data Priority, which will be the highest data priority available unless otherwise specified. MRM is a management protocol like GCC, and has access to all the data priorities. + +All MRM PDUs are categorized into either request, response, or indication classes. Request PDUs are defined to be those that require a corresponding response PDU in return. Indication PDUs are those that do not require a response (or in some cases, where the response is provided indirectly). For request PDUs which do not correspond to mandatory functionality, a generic response PDU (FunctionNotSupportedResponse) may be used and is specified in the GCC Recommendation (T.124), which allows the MRM provider receiving a request to respond to the requesting node without needing to have knowledge of the format of the specific response PDU. To allow the requester to know what this PDU is in response to, the entire request PDU is included within the FunctionNotSupportedResponse PDU. The FunctionNotSupportedResponse PDU shall be sent at the same priority level as that of the received request PDU. + +NOTE – This terminology (request, response, indication) does not have a one-to-one correspondence to the definition of request, indication, response, and confirm used in the definition of the primitives. The terminology has been chosen to relate to the primary purpose of the PDU types with respect to the functions that they will perform. For this reason, the term "confirm" was not needed to describe PDUs, response PDUs are those which are sourced from a response primitive and result in a confirm primitive. + +The MRM protocol includes support for non-standard extensions. On receipt of a nonStandardRequest PDU, an MRM Provider which does not understand the request shall issue a FunctionNotSupportedResponse PDU in return. A non-standard response or a non-standard Indication PDU may be ignored by an MRM provider. + +## 10.6 Framework PDUs + +#### FrameworkLoadIndication + +*Service link:* 9.3 + +*ASN.1 link:* 11 + +A FrameworkLoadIndication is initiated by the MRM top provider when it detects that a node has joined the MRM conference as a network Element and specified the "Shadow Top Provider application capability". On receiving the GCC application roster report containing this capability, the MRM top provider will generate a FrameworkLoadIndication MRMPDU containing a copy of the active framework, specified as a list of parameters that modify the default settings, and send it on the MRM-Conference-Management-Channel at Top data priority. This capability is a logical collapsing capability and each time the node count increases for this capability the MRM top provider should re-send the PDU. Network elements not requiring the framework should ignore this PDU. (See Table 38.) + +**Table 38/T.137 – FrameworkLoadIndication MRMPDU** + +| Content | Source | Sink | +|-----------------------------------------|------------------|--------------| +| New Defaults Flag | MRM Top Provider | MRM Provider | +| Framework Originator Handle | MRM Top Provider | MRM Provider | +| Framework Handle | MRM Top Provider | MRM Provider | +| Conference Name | MRM Top Provider | MRM Provider | +| Conference Description | MRM Top Provider | MRM Provider | +| Conference Model | MRM Top Provider | MRM Provider | +| Enable Distributed Management | MRM Top Provider | MRM Provider | +| Primary Site ID | MRM Top Provider | MRM Provider | +| Slave Sites | MRM Top Provider | MRM Provider | +| Max Conventional Nodes Permitted | MRM Top Provider | MRM Provider | +| Max Anonymous Nodes Permitted | MRM Top Provider | MRM Provider | +| Permitted Services List | MRM Top Provider | MRM Provider | +| Permitted functions List | MRM Top Provider | MRM Provider | +| Permitted Roles List | MRM Top Provider | MRM Provider | +| Synchronize with Data Conf Flag | MRM Top Provider | MRM Provider | +| Groups Permitted Flag | MRM Top Provider | MRM Provider | +| Prohibited functions | MRM Top Provider | MRM Provider | +| Max number of Rooms | MRM Top Provider | MRM Provider | +| Max Depth of Rooms | MRM Top Provider | MRM Provider | +| Participant Conf Roster Reporting Flags | MRM Top Provider | MRM Provider | +| Participant Room Roster Reporting Flags | MRM Top Provider | MRM Provider | +| Observer Conf Roster Reporting Flags | MRM Top Provider | MRM Provider | +| Observer Room Roster Reporting Flags | MRM Top Provider | MRM Provider | +| Number of Pre-defined rooms | MRM Top Provider | MRM Provider | +| Predefined Room list | MRM Top Provider | MRM Provider | +| Room Constructor List | MRM Top Provider | MRM Provider | + +**Table 38/T.137 – FrameworkLoadIndication MRMPDU (continued)** + +| Content | Source | Sink | +|--------------------------------------------------------------------------------------------------------|------------------|--------------| +| MRM Service Framework | MRM Top Provider | MRM Provider | +| Room 1 | | | +| Associated Framework Room ID | MRM Top Provider | MRM Provider | +| Framework Room ID | MRM Top Provider | MRM Provider | +| Room Name | MRM Top Provider | MRM Provider | +| Room Purpose Descriptor | MRM Top Provider | MRM Provider | +| Room Type | MRM Top Provider | MRM Provider | +| Room Model | MRM Top Provider | MRM Provider | +| Room Appearance | MRM Top Provider | MRM Provider | +| Room Function | MRM Top Provider | MRM Provider | +| Room Mode | MRM Top Provider | MRM Provider | +| Room Parent | MRM Top Provider | MRM Provider | +| Room Management Regime | MRM Top Provider | MRM Provider | +| Room Media | MRM Top Provider | MRM Provider | +| Room Access Regime | MRM Top Provider | MRM Provider | +| Child rooms Permitted | MRM Top Provider | MRM Provider | +| Max Participants Permitted | MRM Top Provider | MRM Provider | +| Max Observers Permitted | MRM Top Provider | MRM Provider | +| Secretary Required Flag | MRM Top Provider | MRM Provider | +| Secretary Access Key | MRM Top Provider | MRM Provider | +| Operator Required Flag | MRM Top Provider | MRM Provider | +| Operator Access Key | MRM Top Provider | MRM Provider | +| Groups Required List | MRM Top Provider | MRM Provider | +| Group Access Key(s) | MRM Top Provider | MRM Provider | +| Entry Regime | MRM Top Provider | MRM Provider | +| Exit Regime | MRM Top Provider | MRM Provider | +| Audio Support Required flag
Audio only support | MRM Top Provider | MRM Provider | +| Floor control required flag
Start-up configuration
MRM Service list
GCC App Jurisdiction List | MRM Top Provider | MRM Provider | +| Service Constructor Handle | MRM Top Provider | MRM Provider | +| Number of Audio channels per node | MRM Top Provider | MRM Provider | +| Number of Participants per node | MRM Top Provider | MRM Provider | +| Number of mixer inputs | MRM Top Provider | MRM Provider | +| Number of Audio Ports per Mix | MRM Top Provider | MRM Provider | +| Number of separate Audio Mixers | MRM Top Provider | MRM Provider | +| Required number of Inter NE Channels | MRM Top Provider | MRM Provider | +| Required Number of Terminal Access Channels | MRM Top Provider | MRM Provider | + +**Table 38/T.137 – FrameworkLoadIndication MRMPDU (concluded)** + +| Content | Source | Sink | +|---------------------------------------------------------------------------------------------------------|------------------|--------------| +| Permissions to Control Mix | MRM Top Provider | MRM Provider | +| Start-Up Mode | MRM Top Provider | MRM Provider | +| Supported Mixing Modes
Distributed – Management by speaker detection
– Centrally
– Manual | MRM Top Provider | MRM Provider | +| Supported features
– Service Announcements
– Floor Control
– Stereo
– Spatial
– Surround | MRM Top Provider | MRM Provider | + +## 10.7 Roster PDUs + +The MRM top provider is responsible for maintaining the MRM roster database; it is also responsible for issuing all RosterReportIndications, RosterUpdateIndications and responding to RosterEnquireRequests. All roster report and update PDUs contain a sequence number allocated by the MRM top provider. This mechanism allows the receiver to reconstruct the relative order of any roster information that it receives and thus avoid any potential of losing information or overwriting new information with old. + +The MRM top provider maintains a separate number sequence for each channel it provides updates of. Each Update issued on a given channel causes that channel's sequence number to be incremented. Roster reports adopt the current sequence number for the channel that distributes its incremental updates. Roster reports do not cause the sequence number to increment and it is possible that a roster report and an update may contain the same sequence number; however, because updates increment the sequence, the recipient can be sure that the report is more recent than the update. The sequence number is a 16-bit number and if the upper limit is reached the sequence number resumes from zero. + +MRM does not include nodes in terminal room rosters that are participating in a management role. + +### 10.7.1 Roster Reporting + +#### RosterReportIndication + +*Service link: 9.4.1.1* + +There are three cases that will trigger the MRM top provider to initiate a RosterReportIndication. + +The first case is when a node joins the MRM conference and enrolls active in the MRM session. The MRM top provider as a member of the MRM session will receive the GCC-Application-Roster-Report for the MRM application. The top provider should update its MRM conference participants list from the GCC-provided information. If new nodes are detected, the MRM top provider sends each of them an MRM conference roster using a RosterReportIndication PDU, sent to their MRM UserID at Top data priority. + +The second case is when a node enters an MRM room, the MRM top provider initiates a RosterReportIndication upon receiving an MRM-Room-Enter Response with the result "success" from the Conference Manager. The roster report contains a room roster and is sent directly to the node entering the MRM room on its User ID channel, sent at Top data priority. + +In both of these cases, the content of the roster report is determined by the following criteria: the reason for the report, the default framework, or a new framework that has been loaded, and also the level of participation of the recipient node(s). MRM Participants and MRM observers have separate roster reporting specifications defined within the MRM framework that determine exactly what their roster reports will contain for a conference and for a room. + +If the report results from a node joining the MRM conference, it will be sent conference roster information with the current sequence number from the MRM-Conference-Communication-Channel sequence. If the report results from a node entering an MRM room, it will be sent room roster information for the room being entered and the current sequence number drawn from the Room-Participant-Communication-Channel sequence. If a node is participating as an MRM observer, it may receive only a subset of the information provided to an MRM participant, delivered on the Room-Observer-Communication-Channel with the related sequence number. + +The third case that will cause a RosterReportIndication is when the MRM top provider responds to a RosterEnquireIndication. In this case, the MRM top provider will construct the report based upon the information requested in the RosterEnquireIndication. It will then generate the RosterReportIndication and send it to the Enquirer's MRM User ID at High data priority. + +In addition to the roster reports initiated by the MRM top provider the conference manager may initiate a roster report by sending an MRM-Roster-Report request specifying the required contents of the Report. The MRM top provider will construct the report based upon the information requested in the MRM-Roster-Report request. It will then generate the RosterReportIndication and send it to the specified channel at High data priority. (See Table 39.) + +**Table 39/T.137 – RosterReportIndication MRMPDU** + +| Content | Source | Sink | +|--------------------------------------|------------------|----------| +| Roster Sequence number | MRM Top Provider | Response | +| Scope of Report | MRM Top Provider | Response | +| Conference Configuration Information | MRM Top Provider | Response | +| Conference Status Information | MRM Top Provider | Response | +| Conference Participants List | MRM Top Provider | Response | +| Room Configuration | MRM Top Provider | Response | +| Room Status | MRM Top Provider | Response | +| Room ParticipantsList | MRM Top Provider | Response | +| Participant Details | MRM Top Provider | Response | + +On receipt of a RosterReportIndication PDU, the MRM provider shall first check the roster sequence number to ensure it is greater than that of any previously received roster report on its User ID channel or update sequence number for its associated update channel. If the sequence number is lower, then the MRM provider should check its store roster messages and re-order them into the right sequence. If the sequence number is higher but not consecutive with the previously received roster report or update, then it should be stored until the missing report or update arrives. If two roster PDUs arrive with the same sequence number, then one will be an update and the other will be a report. The update will proceed the report. + +Once a correctly sequence roster report is received, the MRM provider generates an MRM-Roster-Report indication primitive and issues it to the Control MRMSAP. It may also update its local database if it maintains one. + +### 10.7.2 Updating participants roster information + +#### RosterUpdateIndication + +The MRM top provider initiates a RosterUpdateIndication when information in its MRM roster database is updated and this results a change in parameters that have been previously included as part of a roster report or a roster update change. The MRM top provider constructs the RosterUpdateIndication PDU to contain only the changes from the last report or update and it inserts the roster sequence number into the PDU following the rules defined in 10.7. Conference-wide updates are sent on the MRM-Conference-Communication-Channel. If the report relates to a room, it will be sent either on the room's MRM-Room-Participant-Communication-Channel or on the MRM-Room-Observer-Communication-Channel. If the update is for network elements, it is sent on the MRM-Conference-Management-Channel. (See Table 40.) + +**Table 40/T.137 – RosterUpdateIndication MRMPDU** + +| Content | Source | Sink | +|--------------------------------------|------------------|------------| +| Roster Sequence Number | MRM Top Provider | Indication | +| Scope of Update | MRM Top Provider | Indication | +| Conference Configuration Information | MRM Top Provider | Indication | +| Conference Status Information | MRM Top Provider | Indication | +| Conference Participants List | MRM Top Provider | Indication | +| Room Configuration | MRM Top Provider | Indication | +| Room Status | MRM Top Provider | Indication | +| Room Participants List | MRM Top Provider | Indication | +| Participant Details | MRM Top Provider | Indication | + +When an MRM provider receives a RosterUpdateIndication, it shall first check the sequence number to ensure that it is higher than any previously received sequence numbers for the channel. If it is lower, then the provider should check stored updates and process them in the correct order, generating the MRM-Roster-Update indications in the correct sequence. If the update sequence number is higher but not consecutive with the previous sequence number, it should be stored until the missing update arrives. If the sequence number is the same as one previously received, then the update should be disregarded as it was issued prior to the roster report already received and processed. + +Once a correctly sequence roster update is received, the MRM provider generates an MRM-Roster-Update Indication primitive and issues it to the Control MRMSAP. It may also update its local database if it maintains one. + +#### 10.7.2.1 Roster Enquiry + +#### RosterEnquireIndication + +*Service link: 9.4.1.3* + +On receipt of an MRM-Roster-Enquire request primitive, the MRM provider shall send a RosterEnquireIndication PDU which contains the roster fields specified in the MRM-Roster-Enquire request. The MRM provider shall then send the RosterEnquireRequest PDU to the MRM-Conference-Management-Channel, specifying High data priority. (See Table 41.) + +**Table 41/T.137 – RosterEnquireRequest MRMPDU** + +| Content | Source | Sink | +|----------------------------------------------|---------|------------------| +| Request Room List | Request | Top MRM Provider | +| Request Room templates | Request | Top MRM Provider | +| Room/channel ID | Request | Top MRM Provider | +| Request Room Configuration | Request | Top MRM Provider | +| Request Room Status | Request | Top MRM Provider | +| Request Room Participants List | Request | Top MRM Provider | +| Request Conference Configuration Information | Request | Top MRM Provider | +| Request Conference Status Information | Request | Top MRM Provider | +| Request Conference Participants Information | Request | Top MRM Provider | + +Replies to RosterEnquireRequests are made using the roster update mechanisms described above. + +## 10.8 Room PDUs + +### 10.8.1 Creating an MRM Room + +#### RoomCreateRequest + +*Service link: 9.5.1.1* + +On receipt of an MRM-Room-Create request primitive, the MRM provider shall first check the Room Mode parameter. If the Mode is "dynamic" or "private", then the MRM provider shall obtain a dynamic MCS channel for the room by issuing an MCS ChannelConveneRequest. The ChannelConveneConfirm returns a channel ID is inserted into the Channel ID parameter, and a RoomCreateRequest PDU is constructed that contains the room creation parameters. It is sent to the MRM Conference Management-Channel at High data priority. If the Mode is "Static", the Room-Create will fail and the result will be set to "Invalid parameters" and an MRM-Room-Create confirm is immediately generated and issued to the Control MRMSAP. (See Table 42.) + +**Table 42/T.137 – RoomCreateRequest MRMPDU** + +| Content | Source | Sink | +|---------------------|---------|------------------| +| Room ID Handle | Request | MRM Top Provider | +| Room Ownership Flag | Request | MRM Top Provider | +| Room Parent | Request | MRM Top Provider | +| Framework Room ID | Request | MRM Top Provider | + +**Table 42/T.137 – RoomCreateRequest MRMPDU (concluded)** + +| Content | Source | Sink | +|------------------------|---------|------------------| +| Use Template Flag | Request | MRM Top Provider | +| Room Template ID | Request | MRM Top Provider | +| Room Mode | Request | MRM Top Provider | +| Room Media | Request | MRM Top Provider | +| Room Access | Request | MRM Top Provider | +| Room Entry regime | Request | MRM Top Provider | +| Room Exit Regime | Request | MRM Top Provider | +| Room Name String | Request | MRM Top Provider | +| Room Purpose String | Request | MRM Top Provider | +| Number of Participants | Request | MRM Top Provider | +| Number of Observers | Request | MRM Top Provider | +| Required Roles List | Request | MRM Top Provider | +| Required Services List | Request | MRM Top Provider | + +The MRM top provider shall, on receipt of the RoomCreateRequest PDU, verify that the requesting node is authorized to create a room by checking the framework parameters MaxDepthOfRooms, MaxNumberOfRooms and prohibited PDUs. If any of the framework limits will be exceeded by accepting the request, or the requesting node is not authorized to send that PDU, then the request will be denied and the result will be returned informing the requester that the request has been refused and identifying the reason. + +If the requesting node is authorized to create a room, the MRM top provider checks the RoomOwnerFlag. If the flag is set to FALSE, then the MRM Top provider issues an MCS ChannelConveneRequest to obtain a channel ID for the room; the MCS Channel ID becomes the MRM Room ID. If the RoomOwnerFlag is set to TRUE, then the request will provide an MCS channel for the room contained in the Room ID parameter, and the MRM top provider proceeds to create an MRM room entry in its database and associating it with the MCS Channel ID it has just obtained. The database is part of the MRM conference roster and the database entry may result in RosterUpdateResponses being sent if participating nodes have previously requested Conference Roster information or if the framework specifies it should be distributed. If the MCS-Channel-Convene fails, the MRM-Room-Create request will also be denied and a result will be returned identifying the failure reason that prohibits the request. + +The MRM top provider also acts on framework requirements as part of its initialization procedure. This may involve creating and configuring MRM rooms according to the framework room constructor specification. + +#### **RoomCreateResponse** + +The top MRM provider responds to the RoomCreateRequest PDU by generating a RoomCreateResponse PDU which it sends to the requesting node. If the room was successfully created, the top MRM Provider will provide the MRM Room ID in the Room ID handle parameter field and create a master key for the room and then set the result to "Successful". + +If the request is rejected, the MRM Room ID is set to "Null" and the result contains one of the following reason codes "out of MCS Resources", "Room Depth Exceeded", "Max Rooms Exceeded", "prohibitedByFramework". (See Table 43.) + +**Table 43/T.137 – RoomCreateResponse MRMPDU** + +| Content | Source | Sink | +|-----------------|------------------|---------| +| Room ID handle | MRM Top Provider | Confirm | +| Room Master Key | MRM Top Provider | Confirm | +| Result | MRM Top Provider | Confirm | + +An MRM provider shall, on receipt of RoomCreateResponse subsequent to sending an RoomCreateRequest, generate an MRM-Room-Create confirm primitive containing the Room ID parameter and the result indicating if the request was successful or not. + +### 10.8.2 Entering An MRM Room + +#### RoomEnterRequest + +*Service link: 9.5.1.2* + +On receipt of an MRM-Room-Enter request primitive, the MRM provider shall construct a RoomEnterRequest PDU which contains the parameters supplied in the request plus the Room ID the participant node is currently in. If the node has just entered the conference, it will be placed in the lobby and the Room ID will be zero. The MRM provider shall then send a RoomEnterRequest PDU to the MRM-Conference-Management-Channel, specifying Top data priority. (See Table 44.) + +**Table 44/T.137 – RoomEnterRequest MRMPDU** + +| Content | Source | Sink | +|---------------------------|----------------------|------------------| +| Requesting node ID | MRM Provider | MRM Top Provider | +| Enter Room ID | Request/MRM Provider | MRM Top Provider | +| Current Room ID | MRM Provider | MRM Top Provider | +| Type of participation | Request/MRM Provider | MRM Top Provider | +| Terminate/Suspend Flag | Request/MRM Provider | MRM Top Provider | +| Room Access Key Parameter | Request/MRM Provider | MRM Top Provider | +| Reason for entry | Request/MRM Provider | MRM Top Provider | + +On receipt of a RoomEnterRequest, the MRM top provider must first do some basic checks on the room's ability to accommodate the entrant. It must check that the "RoomState" be either "Ready" or "Active", otherwise the result is set to "InvalidRoomID". Depending on the class of entrant, it must check the "MaxParticipants" or "MaxObservers" against the "NumParticipants" or "NumObservers" parameters to ensure that room limits will not be exceeded by the new entrant. If the limits are exceeded, the result is set to "RoomLimitsExceeded". Next, the MRM top provider shall validate the RoomAccessKey. If this corresponds to the master key for the room, then the top MRM provider will proceed to process the request by setting the result to "Successful", irrespective of the room access and entry regime. + +If the master key was not provided, then the MRM top provider will check the entry regime for the room. If the entry regime is "Direct" and the RoomAccessModel is "Open" the MRM top provider can proceed to process the request by setting the result to "Successful". If the entry regime is "Direct" and the RoomAccessModel is "Controlled" the MRM top provider must check of the RoomAccessKey is valid for the room. If it is, then the result is set to "Successful"; otherwise, it is set to "NotAuthorized". If entry regime is "By Invitation", the MRM top provider will reject the request by setting the result to "PrivateRoom". + +If the RoomEntryRegime is set to "ViaDoorKeeper", the MRM top provider will generate a PermissionAskPDU and send it to the node holding a "Door Keeper" role as specified in the room creation parameters or the framework room constructor. The PrivateRoomID in the PermissionAskRequest is set to a reception Room ID selected from a list of at least one reception room specified when the room was created. If no reception is free, the request will be held until a reception room and a "door keeper" are available. The "door keeper" should enter the reception room (setting the suspend flag so it will continue to receive state information from the main room). If the RoomEntryRegime is "ViaAutomatedReception", then the MRM top provider takes the Reception Room ID and puts it in the "Goto Room ID" parameter of the RoomEnterResponse PDU; it then sets the result to "GotoSpecifiedRoom". + +The MRM top provider having processed the request now generates a RoomEnterResponse PDU containing the result and any Room IDs placed into the "Goto Room ID" parameter and sends it on the User ID channel of the requester at Top data priority. + +If the result is successful, the MRM top provider will update the room roster, adding the requesting node to the room and removing it from the room it was previously in; at the same time it must check roles, groups and services for any required actions in leaving the previous room and joining the new room and follow the procedure specified there for leaving and entering MRM rooms. + +#### RoomEnterResponse + +Finally, the top MRM provider shall construct a RoomEnterResponse PDU containing the result of the RoomEnterRequest and send it to the MRM User ID of the node entering the room at Top data priority. (See Table 45.) + +**Table 45/T.137 – RoomEnterResponse MRMPDU** + +| Content | Source | Sink | +|-----------------------|------------------|---------| +| Enter Room Channel ID | MRM Top Provider | Confirm | +| Room Access Key | MRM Top Provider | Confirm | +| Channel to Join | MRM Top Provider | Confirm | +| Reason for entry | MRM Top Provider | Confirm | +| Result | MRM Top Provider | Confirm | + +The MRM provider that initiated the RoomEnterRequest shall on receipt of the RoomEnterResponse PDU generate an MRM-Room-Enter confirm primitive containing the result indicating if the request was successful or not. If the result is "Successful", then the MRM provider shall use the Channel ID returned in the Destination Room Channel ID parameter as the channel to be joined (if provided), and it will issue an MCS ChannelJoin request PDU in order to join the MCS channel for the room. The joining of the MCS channel is confirmed by MCS with the ChannelJoin confirm PDU and, providing this is successful, the MRM provider sends a RoomReadyIndication back to the MRM top provider at Top data priority. + +#### RoomReadyIndication + +The RoomReadyIndication PDU is only used as part of the Room Entry procedure to tell the MRM top provider that the node entering a room has joined the appropriate channels for the room and is ready to receive room roster information. (See Table 46.) + +**Table 46/T.137 – RoomReadyIndication MRMPDU** + +| Content | Source | Sink | +|---------|--------------|------------------| +| Room ID | MRM Provider | MRM Top Provider | + +Once the MRM top provider receives the RoomReadyIndication, it generates a RosterReport that contains a room roster for the room that the node has just entered. The RosterReport is sent directly to the node entering the room on its User ID channel at Top data priority. Once a node is in the room, it receives roster updates as deltas to the roster report on the room communication channel that it joined. + +### 10.8.3 Invitation to an MRM Room + +#### RoomInviteIndication + +*Service link: 9.5.1.3* + +On receipt of an MRM-Room-Invite request primitive, the MRM provider shall construct a RoomInviteIndication PDU which contains the parameters supplied in the request. The MRM provider shall then send a RoomInviteIndication PDU to each of the MRM User IDs specified in the Invited node list, specifying High data priority. The MRM provider then generates an MRM-Room-Invite confirm and issues it to its Control MRMSAP. (See Table 47.) + +**Table 47/T.137 – RoomInviteIndication MRMPDU** + +| Content | Source | Sink | +|-----------------------------------|---------|------------| +| Room ID Handle | Request | Indication | +| Room Entry Key | Request | Indication | +| Invited Node List of MRM User IDs | Request | Indication | +| Invitor's MRM User ID | Request | Indication | +| Reason String | Request | Indication | + +On receipt of a RoomInviteIndication PDU, an MRM provider will generate an MRM-Room-Invite indication and send it to its node controller on the Control MRMSAP. Nodes wishing to accept the invitation use the MRM-Room-Enter procedure. + +### 10.8.4 Creating a group + +#### GroupCreateRequest + +*Service link: 9.6.3.1* + +On receipt of an MRM-Group-Create request primitive, the MRM provider shall construct a GroupCreateRequest PDU which contains the parameters supplied in the request. The MRM provider shall then send it to the MRM Top Provider on the MRM-Conference-Management-Channel specifying High data priority. (See Table 48.) + +**Table 48/T.137 – GroupCreatRequest MRMPDU** + +| Content | Source | Sink | +|---------------------------|---------|------------------| +| Group Owner's MRM User ID | Request | MRM Top Provider | +| Group Scope Flag | Request | MRM Top Provider | +| Room ID Handle | Request | MRM Top Provider | +| Group Name | Request | MRM Top Provider | +| Group Function | Request | MRM Top Provider | +| Ordered Group Flag | Request | MRM Top Provider | +| Members List | Request | MRM Top Provider | + +On receipt of a GroupCreateRequest PDU, the MRM top provider checks the creator has "group creation" role privileges. If it does, then the MRM top provider sets the result to "Successful". If the creator does not have the appropriate privileges then the result is set to "Not Authorized". + +#### GroupCreateResponse + +If the request is permitted, the MRM top provider obtains an MCS channel for the group and then makes the database entries for the group. In all cases the MRM top provider generates a GroupCreateResponse PDU containing the result, and sends it to the requesting node on its User ID channel at High data priority. A successful group creation results in an MRM roster update announcing the group. This also serves to inform the group members of their participation. (See Table 49.) + +**Table 49/T.137 – GroupCreateResponse MRMPDU** + +| Content | Source | Sink | +|----------------|------------------|---------| +| Room ID Handle | MRM Top Provider | Confirm | +| Group ID | MRM Top Provider | Confirm | +| Result | MRM Top Provider | Confirm | + +On receipt of the RoomDestroyResponse PDU the MRM Provider sends an MRM-Room-Destroy confirm containing the room reference and the result code. + +#### GroupDisbandRequest + +*Service link: 9.6.3.2* + +On receipt of an MRM-Group-Disband request primitive, the MRM top provider shall construct a GroupDisbandRequest PDU which contains the parameters supplied in the request. The MRM provider shall then send it to the MRM top provider on the MRM-ConferenceManagement-Channel specifying High data priority. (See Table 50.) + +**Table 50/T.137 – GroupDisbandRequest MRMPDU** + +| Content | Source | Sink | +|-------------|---------|------------------| +| Group Owner | Request | MRM Top Provider | +| Room ID | Request | MRM Top Provider | +| Group ID | Request | MRM Top Provider | + +On receipt of a GroupDisbandRequest PDU, the MRM top provider checks that the requester either has "group create/modify/destroy" role privileges, or is the owner of the group. If it does, the group is deleted from the MRM conference database, the result is set to "successful" and an MRM-Group-Disband indication is sent on the Control MRMSAP to its node controller. The destruction of a group will trigger a RosterUpdateIndication to any node monitoring that information. + +#### GroupDisbandResponse + +The MRM Top Provider then generates a GroupDisbandResponse PDU containing the reference to the room requested to be destroyed and the result indicating if the request was successful or providing the reason why it failed. (See Table 51.) + +**Table 51/T.137 – GroupDisbandResponse MRMPDU** + +| Content | Source | Sink | +|----------|------------------|---------| +| Group ID | MRM Top Provider | Confirm | +| Result | MRM Top Provider | Confirm | + +On receipt of the GroupDisbandResponse PDU, the MRM provider sends an MRM-Group-Disband confirm containing the room reference and the result code. + +#### GroupMemberSpecifyRequest + +*Service link: 9.6.3.3* + +On receipt of an MRM-Group-Member-Specify request primitive, the MRM provider shall construct a GroupMemberSpecifyRequest PDU which contains the parameters supplied in the request. The MRM provider shall then send it to the MRM-Conference-Management-Channel specifying High data priority. (See Table 52.) + +**Table 52/T.137 – GroupMemberSpecifyRequest MRMPDU** + +| Content | Source | Sink | +|---------------------------|---------|------------| +| Group Identifier | Request | Indication | +| Add Participants List | Request | Indication | +| Remove Participants List | Request | Indication | +| Specify Participants List | Request | Indication | + +On receipt of a GroupMemberSpecifyRequest PDU, the MRM top provider shall check that the requester either has "group create/modify/destroy" role privileges, or is the owner of the group. If it is authorized, the conference database is amended to reflect the request, and the result is set to "successful". The changes to a group's membership will trigger a RosterUpdateIndication to any node monitoring that information. + +#### GroupMemberSpecifyResponse + +The MRM TopProvider generates a GroupMemberSpecifyResponse PDU and sends it to the requester's User ID at High data priority. (See Table 53.) + +**Table 53/T.137 – GroupMemberSpecifyResponse MRMPDU** + +| Content | Source | Sink | +|------------------|----------|---------| +| Group Identifier | Response | Confirm | +| Result | Response | Confirm | + +On receipt of a GroupMemberSpecifyResponse PDU, an MRM provider generates an MRM-Group-Member confirm and sends it to the Control MRMSAP to its node controller. + +### 10.9 T.120 Session Association + +#### SessionAssociateRequest + +*Service link: 9.7.1.1* + +On receipt of an MRM-Session-Associate request primitive, the MRM top provider shall construct a SessionAssociate PDU which contains the parameters supplied in the request. The MRM provider shall then send it to the MRM top provider on the MRM-ConferenceManagement-Channel specifying High data priority. (See Table 54.) + +**Table 54/T.137 – SessionAssociateRequest MRMPDU** + +| Content | Source | Sink | +|---------------------|---------|------------------| +| Room ID | Request | MRM Top Provider | +| Associated Sessions | Request | MRM Top Provider | + +On receipt of a SessionAssociateRequest PDU, the MRM top provider first checks that the requesting node has privileges to modify room parameters. If it does, it makes an entry in the room roster for the specified room and sets the result to "Successful"; otherwise, it sets the result to "Not Authorized". A successful session association causes a RosterUpdate PDU to be sent to any node in the room monitoring this information. + +#### SessionAssociateResponse + +The MRM top provider then generates a SessionAssociateResponse PDU containing the result parameter and sends it to the requester on its User ID channel at Top data priority. (See Table 55.) + +**Table 55/T.137 – SessionAssociateResponse MRMPDU** + +| Content | Source | Sink | +|---------|------------------|----------| +| Result | MRM Top Provider | Response | + +## 10.10 Room role PDUs + +### 10.10.1 Assigning an MRM role + +The MRM room roster will contain a list of roles available to the room that is passed to participant nodes when they enter the room. Each provider is required to maintain a list of active roles and role holders for the room that it is in. The chair role is available for use in the default framework specification. + +#### RoomRoleAssignRequest + +*Service link: 9.8.2.1* + +On receipt of an MRM-Room-Role-Assign primitive, the MRM provider constructs a RoomRoleAssignRequest PDU from the request and inserts its nodes MRM User ID and sends it to the MRM top provider on the MRM-Conference-Management-Channel at Top data priority. (See Table 56.) + +**Table 56/T.137 – RoomRoleAssignRequest MRMPDU** + +| Content | Source | Sink | +|-----------------------------------|--------------|------------------| +| Requesting Node's MRM User ID | MRM Provider | MRM Top Provider | +| Proposed Role Holders MRM User ID | Request | MRM Top Provider | +| MRM Room Identifier | Request | MRM Top Provider | +| MRM Room Role Identifier | Request | MRM Top Provider | +| MRM Role Access Key | Request | MRM Top Provider | +| Group Identifier | Request | MRM Top Provider | + +On receipt of a RoomRoleAssign PDU, the MRM top provider checks if the role requested is available for assignment by searching the MRM conference roster PermittedRoles list. If it is not permitted, the result is set to "RoleNotPermitted". If the role is permitted, the top MRM provider next checks if the role is already assigned. If it is, the result is set to "RoleAlreadyAssigned". If the role is permitted and available for assignment, then the MRM top provider checks the roster database, looking for any access key requirement associated with that role. If a key is required, the MRM top provider checks the MRM Role Access Key parameter in the request. If it holds a key, it attempts to validate the key against its database key. If the key is not validated, the result is set to "InvalidKey". If the requesting node meets all the conditions, then the MRM top provider updates the room roster, assigning the requesting node the role. + +#### RoomRoleAssignResponse + +On completion of processing the RoomRoleAssignRequest PDU, the MRM top provider constructs a RoomRoleAssignResponse PDU, inserts the result, and sends it to the MRM User ID of the requesting node at Top data priority. (See Table 57.) + +**Table 57/T.137 – RoomRoleAssignResponse MRMPDU** + +| Content | Source | Sink | +|-------------|------------------|---------| +| MRM Room ID | MRM Top Provider | Confirm | +| MRM Role | MRM Top Provider | Confirm | +| Result | MRM Top Provider | Confirm | + +On receipt of a RoomRoleAssignResponse, the MRM provider which initiated the request sends an MRM-Room-Role-Assign confirm containing the result indicating whether the request was successful or not. + +### 10.10.2 Relinquishing an MRM role + +#### RoomRoleReleaseRequest + +*Service link: 9.8.2.2* + +On receipt of an MRM-Role-Release request primitive, the MRM provider constructs a RoomRoleReleaseRequest PDU and sends it to the MRM top provider on the MRM-Conference-Management-Channel at Top data Priority. (See Table 58.) + +**Table 58/T.137 – RoomRoleReleaseRequest MRMPDU** + +| Content | Source | Sink | +|------------------------|---------|------------------| +| MRM Room Identifier | Request | MRM Top Provider | +| Role Holder Identifier | Request | MRM Top Provider | +| MRM Room Role | Request | MRM Top Provider | +| Group ID | Request | MRM Top Provider | +| Release Reason | Request | MRM Top Provider | + +On receipt of a RoomRoleReleaseRequest PDU, the MRM top provider updates its room roster database removing the role assignment and then it generates a response to indicate that the request has been dealt with. The role release will trigger a RosterUpdateIndication to the nodes in that room that are monitoring this information. + +#### RoomRoleReleaseResponse + +The MRM top provider constructs a RoomRoleReleaseResponse PDU, inserts the result and sends it to the MRM User ID of the requesting node at Top data priority. (See Table 59.) + +**Table 59/T.137 – RoomRoleReleaseResponse MRMPDU** + +| Content | Source | Sink | +|---------------------|---------------------------------|---------| +| MRM Room Identifier | MRM Top Provider (from Request) | Confirm | +| MRM Room Role | Request (from Request) | Confirm | +| Result | MRM Top Provider | Confirm | + +On receipt of the RoomRoleReleaseResponse, the MRM provider that initiated the RoomRoleReleaseRequest generates an MRM-Room-Role-Release response primitive and sends it to the Control MRMSAP. + +#### RoomRoleReleaseIndication + +The MRM top provider constructs a RoomRoleReleaseResponse PDU, inserts the result and sends it to the MRM User ID of the requesting node at Top data priority. (See Table 60.) + +**Table 60/T.137 – RoomRoleReleaseIndication MRMPDU** + +| Content | Source | Sink | +|-----------------------------|--------------|------------------| +| Requesting Node MRM User ID | MRM Provider | MRM Top Provider | +| MRM Room Identifier | Request | MRM Top Provider | +| MRM Room Role Identifier | Request | MRM Top Provider | +| Group Identifier | Request | MRM Top Provider | +| Release Reason | Request | MRM Top Provider | + +On receipt of a RoomRoleReleaseIndication PDU, the MRM provider generates an MRM-Room-Role-Release response primitive and sends it to the Control MRMSAP. + +### 10.10.3 Asking for an MRM role + +#### RoomRolePleaseRequest + +*Service link: 9.8.2.3* + +On receipt of an MRM-Role-Please request primitive, the MRM provider constructs a RoomRolePleaseRequest PDU and, using the information on role holder User IDs in its local database, sends the PDU to the identified role holder's MRM User ID at High data priority. The MRM provider then generates an MRM-Room-Role-Please confirm primitive and sends it to its Control MRMSAP. (See Table 61.) + +**Table 61/T.137 – RoomRolePleaseRequest MRMPDU** + +| Content | Source | Sink | +|-----------------------------|--------------|------------------| +| Requesting Node MRM User ID | MRM Provider | MRM Top Provider | +| MRM Room Identifier | Request | MRM Top Provider | +| MRM Room Role Identifier | Request | MRM Top Provider | +| MRM Group Identifier | Request | MRM Top Provider | + +On receipt of a RoomRoleRequest PDU, the MRM provider checks whether it is the current holder of the role being requested. If it is not, it ignores the request. If it is the current holder of the requested role, it generates an MRM-Room-Role-Please indication primitive and sends it to its Control MRMSAP. + +### 10.10.4 Passing An MRM Role to another Room Participant + +#### RoomRoleGiveRequest + +*Service link: 9.8.2.4* + +On receipt of an MRM-Role-Give request primitive, the MRM Provider checks whether it is the current holder of the role to be given. If it is not, the result is set to "NotRoleHolder" and a confirm is immediately generated and sent to the Control MRMSAP with the result indicating the Give request failed. Otherwise, the MRM provider constructs a RoomRoleGiveRequest PDU and sends it on the MRM-Conference-Management-Channel at High data Priority. (See Table 62.) + +**Table 62/T.137 – RoomRoleGiveRequest MRMPDU** + +| Content | Source | Sink | +|-------------------------------------|---------|--------------| +| Role Holder MRM User ID | Request | Indication | +| Role Recipient's Node (MRM User ID) | Request | MRM Provider | +| MRM Room Identifier | Request | Indication | +| MRM Room Role Identifier | Request | Indication | +| Group Identifier | Request | Indication | + +On receipt of a RoomRoleGiveRequest PDU, the MRM provider checks whether the requester is the current role holder. If it is not, it sets the result to "NotRoleHolder". Otherwise, it generates an MRM-Room-Role-Give indication and sends it to its Control MRMSAP. + +#### RoomRoleGiveResponse + +On receipt of an MRM-Room-Role-Give response primitive, the MRM provider generates a RoomRoleGiveResponse PDU and sends it to the requester's MRM User ID at High data priority. (See Table 63.) + +**Table 63/T.137 – RoomRoleGiveResponse MRMPDU** + +| Content | Source | Sink | +|--------------------------|---------|------------| +| MRM Room Identifier | Request | Indication | +| MRM Room Role Identifier | Request | Indication | +| Group Identifier | Request | Indication | +| Result | Request | Indication | + +On receipt of a RoomRoleGiveResponse PDU, the MRM provider generates an MRM-Room-Role-Give confirm primitive and sends it to the Control MRMSAP. + +#### RoomRoleGiveIndication + +The MRM Provider checks the result in the response primitive if it was successful; then, a RoomRoleGiveIndication is generated and sent to the MRM top provider on the MRM-Conference-Management-Channel at High data priority. (See Table 64.) + +**Table 64/T.137 – RoomRoleGiveIndication MRMPDU** + +| Content | Source | Sink | +|------------------------------|---------|------------| +| Giving Node MRM User ID | Request | Indication | +| Recipient Node (MRM User ID) | Request | Indication | +| MRM Room Identifier | Request | Indication | +| MRM Room Role Identifier | Request | Indication | +| Group Identifier | Request | Indication | + +### 10.10.5 Changing role permissions + +#### RolePermissionsModifyRequest + +*Service link: 9.8.2.1* + +On receipt of a MRM-Role-Permission-Modify primitive, the MRM provider constructs a RolePermissionsModifyRequest PDU from the request and inserts its node's MRM User ID; it then sends the PDU to the MRM top provider on the MRM-Conference-Management-Channel at High data priority. (See Table 65.) + +**Table 65/T.137 – RolePermissionsModifyRequest MRMPDU** + +| Content | Source | Sink | +|-----------------------------|--------------|------------------| +| Requesting Node MRM User ID | MRM Provider | MRM Top Provider | +| MRM Room Identifier | Request | MRM Top Provider | +| MRM Room Role Identifier | Request | MRM Top Provider | +| Permissions List | Request | MRM Top Provider | + +On receipt of a RolePermissionsModifyRequest PDU the top MRM provider checks whether the requesting node is authorized to modify role permissions by looking at its existing role permissions. If it is authorized, the MRM top provider sets the result to "Successful". + +#### RolePermissionsModifyResponse + +The MRM top provider constructs a RolePermissionsModifyResponse PDU and sends it to the requester's User ID at High data priority. (See Table 66.) + +**Table 66/T.137 – RolePermissionsModifyResponse MRMPDU** + +| Content | Source | Sink | +|---------|---------|------------------| +| Result | Request | MRM Top Provider | + +On receipt of a RolePermissionsModifyResponse PDU, the MRM provider generates an MRM-Role-Permissions-Modify confirm primitive and issues it to the Control MRMSAP. + +## 10.11 Permission PDUs + +### 10.11.1 Asking the chair for permission to take action + +#### PermissionAskRequest + +*Service link: 9.9.1.1* + +On receipt of an MRM-Permission-Ask request primitive, the MRM provider checks its local database in order to confirm that there is an active chair in the room. This is done by looking in its local database at the assigned role list. If there is no chair, then the request is rejected locally and the Confirm is generated and sent to the node controller on the Control MRMSAP. + +If the chair is contained in the MRM provider's assigned role list, then the MRM User ID associated with the chair entry is used as the destination address for the PermissionAskRequest PDU. The PDU is generated and sent to the chair's MRM User ID at High data priority and the MRM-Permission-Ask primitive is generated with the result "success" and sent to the Control MRMSAP. (See Table 67.) + +**Table 67/T.137 – PermissionAskRequest MRMPDU** + +| Content | Source | Sink | +|-----------------------------|---------|------------| +| Requesting Node MRM User ID | Request | Indication | +| MRM Room Identifier | Request | Indication | +| Permission Requested | Request | Indication | +| Group Permission Request | Request | Indication | +| Associated Service | Request | Indication | + +On receipt of a PermissionAskRequest PDU, the MRM Provider checks whether it is the current "chair" role holder; if it is not, the request is ignored. Otherwise, it generates an MRM-Permission-Ask indication and sends it to its Control MRMSAP. The reply is returned using the Permission grant mechanism and is initiated by the node controller. + +### 10.11.2 Relinquishing Permission + +#### PermissionRelinquishRequest + +*Service link: 9.9.1.2* + +On receipt of an MRM-Permission-Relinquish request primitive, the MRM provider checks its local database to confirm whether there is an active chair in the room. This is done by looking in its local database at the assigned Role list. If there is no chair, then the request is rejected locally and a Confirm is generated containing the result "NoChair". The Confirm is sent to the node controller, on the Control MRMSAP. + +If the chair is on the MRM provider's AssignedRole list, the PermissionRelinquishRequest PDU is generated and sent to the chair's MRM User ID, at High data priority and the MRM-Permission-Relinquish confirm primitive is generated with the result "success" and sent to the Control MRMSAP. (See Table 68.) + +**Table 68/T.137 – PermissionRelinquishRequest MRMPDU** + +| Content | Source | Sink | +|-----------------------------|---------|------------| +| Requesting Node MRM User ID | Request | Indication | +| Permission Relinquished | Request | Indication | +| Release Reason | Request | Indication | +| MRM Room Identifier | Request | Indication | +| Group Permission Release | Request | Indication | +| Associated Service | Request | Indication | + +On receipt of a PermissionRelinquishRequest PDU, the MRM Provider checks whether it is the current chair role holder. If it is not, it ignores the request. Otherwise, it generates an MRM-Permission-Relinquish indication and sends it to its Control MRMSAP. + +### 10.11.3 Chair grants permission + +#### PermissionGrantRequest + +*Service link: 9.9.1.3* + +On receipt of an MRM-Permission-Grant request primitive, the chair's MRM provider sends a PermissionGrantRequest PDU to the MRM User ID of the node identified in the request primitive at High data priority. The MRM provider then generates an MRM-Permission-Grant confirm and issues it to the Control MRMSAP. (See Table 69.) + +**Table 69/T.137 – PermissionGrantRequest MRMPDU** + +| Content | Source | Sink | +|----------------------------|---------|------------| +| Request Handle | Request | Indication | +| Requesting Node | Request | Indication | +| Room Identifier | Request | Indication | +| Permission requested | Request | Indication | +| Group Permission requested | Request | Indication | +| Associated Service | Request | Indication | +| MRM Access Capability | Request | Indication | +| Result | Request | Indication | + +On receipt of a PermissionGrantRequest PDU, the MRM generates an MRM-Permission-Grant indication and sends it to its Control MRMSAP. + +## 10.12 Source Identification PDUs + +#### SourceIdentificationRequest + +*Service link: 9.10.1.1* + +On receipt of an MRM-Source-Identification-Request primitive, the MRM provider shall send a SourceIdentificationRequest PDU to the MRM-Conference-Management-Channel, specifying High data priority. (See Table 70.) + +**Table 70/T.137 – SourceIdentificationRequest MRMPDU** + +| Content | Source | Sink | +|---------------------------|---------|------------| +| Source Handle | Request | Indication | +| Source Channel Identifier | Request | Indication | +| Media Type | Request | Indication | +| Room ID | Request | Indication | +| Stream Descriptor | Request | Indication | +| Reason Code | Request | Indication | + +On receipt of a SourceIdentificationRequest PDU, the MRM provider generates an MRM-Source-Identification indication and sends it to its Control MRMSAP. + +## 10.13 Indication PDUs + +### 10.13.1 Notification of privacy + +#### PrivacyNotifyRequest + +*Service link: 9.10.1.2* + +On receipt of an MRM-Privacy-Notify request primitive, the MRM provider sends a PrivacyNotifyRequest PDU to the MRM-Conference-Management. Channel at High data priority. (See Table 71.) + +**Table 71/T.137 – PrivacyNotifyRequest MRMPDU** + +| Content | Source | Sink | +|-------------------------|---------|--------------| +| Source Handle | Request | Indication | +| Room ID | Request | Indication | +| Media channel ID | Request | MRM Provider | +| Media Type | Request | MRM Provider | +| Invoke Privacy Remotely | Request | MRM Provider | +| Privacy Status | Request | Indication | + +#### PrivacyNotifyResponse + +On receipt of an MRM-Privacy-Notify response primitive, the MRM provider generates an MRM-Privacy-Notify indication primitive and issues it to the Control MRMSAP. Then, it updates its database to record the privacy mode of the requesting node and signals the privacy mode to any services that are active, such as Audio mixing, etc. Then, a PrivacyNotifyResponse PDU is sent on the MRM User ID of the requesting node at High data priority. (See Table 72.) + +**Table 72/T.137 – PrivacyNotifyResponse MRMPDU** + +| Content | Source | Sink | +|--------------------------|--------------|---------| +| Source Handle | MRM Provider | Confirm | +| Media Channel Identifier | MRM Provider | Confirm | +| Media Type | MRM Provider | Confirm | +| Privacy Status | MRM Provider | Confirm | + +On receipt of a PrivacyNotifyResponse PDU, the MRM provider generates an MRM-Privacy-Notify confirm and issues it to the Control MRMSAP. + +#### OnAirIndicationRequest + +*Service link: 9.10.1.3* + +On receipt of an MRM-On-Air-Indication request primitive the MRM provider sends a Request PDU to the MRM User ID of the node identified in the request primitive at High data priority. The MRM provider then generates an MRM-confirm and issues it to the Control MRMSAP. (See Table 73.) + +**Table 73/T.137 – OnAirIndicationRequest MRMPDU** + +| Content | Source | Sink | +|--------------------------|--------------|------------| +| Source Handle | MRM Provider | Indication | +| Media Channel Identifier | Request | Indication | +| Room Identifier | Request | Indication | +| On Air Status Flag | Request | Indication | + +On receipt of an OnAirIndicationRequest PDU, the MRM provider generates an MRM-On-Air-indication and issues it to the Control MRMSAP. + +## 10.14 Service Command PDUs + +#### ServiceCommandRequest + +*Service link: 9.10.1.4* + +On receipt of an MRM-Service-Command request primitive, the MRM provider generates a ServiceCommandRequest PDU which is sent to the MRM Conference Management channel at Top data priority. (See Table 74.) + +**Table 74/T.137 – ServiceCommandRequest MRMPDU** + +| Content | Source | Sink | +|--------------------------------|--------------|------------| +| Requesting Node | MRM Provider | Indication | +| MRM Room ID | Request | Indication | +| MRM Service Command | Request | Indication | +| Service Name ID | Request | Indication | +| Service Mode | Request | Indication | +| Participation Options | Request | Indication | +| Participant and Resources List | Request | Indication | +| Include Observer Nodes – Flag | Request | Indication | + +The MRM top provider shall, on receipt of the ServiceCommandRequest PDU, verify that the requesting node is authorized to execute the command specified in the MRM Service Command parameter by checking the conference framework role permissions list for the requesting node. The MRM top provider must also check the service specified in the MRM service is permitted by the conference framework. This is done by looking for the Service ID in the framework's permitted services list. If the request is permitted by the framework, the MRM top provider generates an MRM-Service-Command primitive and sends it to the Conference Manager on the Control MRMSAP. + +#### ServiceCommandResponse + +The Top MRM provider responds to the MRM-Service-Command-Response primitive by checking the result code; if it is "Successful", then the MRM top provider executes the MRM Service Command. The MRM Top provider generates a ServiceCommandResponse PDU which it sends to the requesting node with the result "Successful" if the Service command was accepted, or "prohibited by Framework" or "Service Unavailable" if the request was not accepted. (See Table 75.) + +**Table 75/T.137 – ServiceCommandResponse MRMPDU** + +| Content | Source | Sink | +|---------------------|---------|------------| +| MRM Room ID | Request | Indication | +| MRM Service Command | Request | Indication | +| Service Name ID | Request | Indication | +| Service Mode | Request | Indication | +| Result | Request | Indication | + +An MRM provider, on receipt of ServiceCommandResponse subsequent to sending an ServiceCommandRequest, shall generate an MRM-Service-Command confirm primitive containing the Result parameter indicating if the request was successful or not. + +## 10.15 Audio Management PDUs + +### 10.15.1 Service initialization + +The Audio Bridging service has a defined behaviour for events that take place in an MRM room that impact upon the Audio Bridging service. + +The conference framework specifies the requirement and the configuration for the Audio Bridging service. The service capabilities are derived from this configuration contained in the Framework's Service Constructor. + +The Audio Bridging service is launched by the MRM top provider, in response to a framework requirement. If there are network elements participating in the conference, the launching of the service causes a ServiceCommand PDU containing the Command to launch. This PDU is sent to the MRM-Conference-Management-Channel at Top data priority. An Indication is also generated locally to the conference manager and issued to the Control MRMSAP. The MRM top provider then includes service capability within the Room roster. + +When a node is subscribing to the Audio Bridging service it is: + +- unsubscribing to the Audio Bridging service; +- entering an MRM room; +- leaving an MRM room. + +### 10.15.2 Audio Mixer Setup + +#### AudioMixerSetRequest + +*Service link: 9.12* + +On receipt of an MRM-Audio-Mixer-Set request primitive, the MRM provider generates an AudioMixerSetRequest PDU and sends it to the MRM top provider on the MRM-Conference-Management-Channel at Top data priority. (See Table 76.) + +**Table 76/T.137 – AudioMixerSetRequest MRMPDU** + +| Content | Source | Sink | +|------------------------------|--------------|------------| +| Originating Node MRM User ID | MRM Provider | Indication | +| MRM Room Identifier | Request | Indication | +| Audio Mixing Mode | Request | Indication | +| Add Node-Stream (List) | Request | Indication | + +**Table 76/T.137 – AudioMixerSetRequest MRMPDU (concluded)** + +| Content | Source | Sink | +|----------------------------|---------|------------| +| Enable Node-Stream (List) | Request | Indication | +| Mute Node-Stream (List) | Request | Indication | +| Include Node-Stream (List) | Request | Indication | +| Remove Node-Stream List | Request | Indication | +| Request Audio Level Adjust | Request | Indication | + +On receipt of an AudioMixerSetRequest PDU, the MRM top provider first checks the role privileges to determine if the originating node is authorized to control audio mixes. If it is not, the result is set to "NotAuthorized". Otherwise, the result is set to "successful". Other network elements receiving the request must also check the privileges in their local version of the framework if they are going to take action based upon this request. Authorized requests result in recipients generating an MRM-Audio-Mixer-Set indication and issuing it to its Control MRMSAP. + +#### **AudioMixerSetResponse** + +The MRM top provider is responsible for sending the response. It generates an AudioMixerSetResponse PDU containing the result code and sends it to the MRM User ID of the requester at Top data priority. (See Table 77.) + +**Table 77/T.137 – AudioMixerSetResponse MRMPDU** + +| Content | Source | Sink | +|------------------------------|------------|---------| +| Originating Node MRM User ID | Indication | Confirm | +| Result | Response | Confirm | + +On receipt of an AudioMixerSetResponse PDU, the MRM provider generates an MRM-Audio-Mixer-Set confirm primitive and issues it to its Control MRMSAP. + +### **10.15.3 Audio Mixer status reporting** + +#### **AudioMixReportRequest** + +*Service link: 9.12.1.2* + +On receipt of an MRM-AudioMix-Report request primitive, the MRM top provider shall construct an AudioMixReportRequest PDU, then send it to the nodes in that room requiring Audio Reports, specifying High data priority to the Recipient's MRM User IDs. (See Table 78.) + +**Table 78/T.137 – AudioMixReportRequest MRMPDU** + +| Content | Source | Sink | +|----------------------------------|---------|------------| +| MRM User ID | Request | Indication | +| MRM Room Identifier | Request | Indication | +| New Speaker MRM User ID | Request | Indication | +| New Speaker Microphone Device ID | Request | Indication | +| Previous Speaker MRM User ID | Request | Indication | + +**Table 78/T.137 – AudioMixReportRequest MRMPDU (concluded)** + +| Content | Source | Sink | +|---------------------------------------|---------|------------| +| Previous Speaker Microphone Device ID | Request | Indication | +| List of Nodes included in mix | Request | Indication | +| List of Active Speakers | Request | Indication | + +On receipt of AudioMixReportRequest PDU, the MRM provider shall generate an MRM-AudioMix-Report indication primitive and issue it to the Control MRMSAP. + +### 10.15.4 Inviting Audio-Only participation + +#### InviteAudioOnlyNodeRequest + +*Service link: 9.12.1.4* + +On receipt of an MRM-Invite-Audio-Only-Node request primitive, the MRM provider generates an InviteAudioOnlyNodeRequest PDU and sends it to the MRM top provider at Top data priority. (See Table 79.) + +**Table 79/T.137 – InviteAudioOnlyNodeRequest MRMPDU** + +| Content | Source | Sink | +|----------------------------|---------|------------| +| DestinationRoom ID Handle | Request | Indication | +| Node Communication Address | Request | Indication | +| Room Access Parameter | Request | Indication | +| Reason for Invitation | Request | Indication | +| Entry Method | Request | Indication | + +On receipt of an InviteAudioOnlyNodeRequest PDU, the MRM provider shall generate an MRM-Invite-Audio-Only-Node indication primitive and issue it to the Control MRMSAP. + +#### InviteAudioOnlyNodeResponse + +The top MRM provider responds to the MRM-Invite-Audio-Only-Mode-Node Response generating an InviteAudioOnlyNodeResponse PDU and sending it to the requesting node with the result, which will be "Accepted" or "prohibited by Framework" or "Function Unavailable" if the request was not rejected. (See Table 80.) + +**Table 80/T.137 – InviteAudioOnlyNodeResponse MRMPDU** + +| Content | Source | Sink | +|---------|----------|---------| +| Result | Response | Confirm | + +An MRM Provider, on receipt of InviteAudioOnlyNodeResponse subsequent to sending an InviteAudioOnlyNodeRequest, shall generate an MRM-Invite-Audio-Only-Node confirm primitive containing the Result parameter indicating if the request was successful or not. + +### 10.15.5 Ejecting an-Audio-Only participant + +#### EjectAudioOnlyNodeRequest + +*Service link: 9.12.1.4* + +On receipt of an MRM-Eject-Audio-Only-Node request primitive, the MRM provider generates an EjectAudioOnlyNodeRequest PDU and sends it to the MRM top provider at High data priority. (See Table 81.) + +**Table 81/T.137 – EjectAudioOnlyNodeRequest MRMPDU** + +| Content | Source | Sink | +|----------------------------|---------|------------| +| Room ID Handle | Request | Indication | +| Node Communication Address | Request | Indication | +| NonT120node User ID | Request | Indication | + +On receipt of EjectAudioOnlyNodeRequest PDU, the MRM provider shall generate an MRM-Eject-Audio-Only-Node indication primitive and issue it to the Control MRMSAP. + +#### EjectAudioOnlyNodeResponse + +The top MRM provider responds to the MRM-Eject-Audio-Only-Node Response by generating an EjectAudioOnlyNodeResponse PDU and sending it to the requesting node with the result, which will be "Accepted" or "prohibited by Framework" or "Function Unavailable" if the request was not rejected. (See Table 82.) + +**Table 82/T.137 – EjectAudioOnlyNodeResponse MRMPDU** + +| Content | Source | Sink | +|---------|----------|---------| +| Result | Response | Confirm | + +An MRM provider, on receipt of an EjectAudioOnlyNodeResponse, subsequent to sending an EjectAudioOnlyNodeRequest, shall generate a MRM-Eject-Audio-Only-Node confirm primitive containing the Result parameter indicating if the request was successful or not. + +#### CallStatusIndication + +*Service link: 9.12.1.4* + +On receipt of an MRM-Call-Status request primitive, the MRM top provider generates an CallStatusIndication PDU and sends it to the MRM provider of the call initiator at High data priority. (See Table 83.) + +**Table 83/T.137 – CallStatusIndication MRMPDU** + +| Content | Source | Sink | +|---------------------|---------|------------| +| Room ID Handle | Request | Indication | +| NonT120node User ID | Request | Indication | +| Status | Request | Indication | + +On receipt of a CallStatusIndication PDU, the MRM provider shall generate an MRM-Call-Status indication primitive and issue it to the Control MRMSAP. + +# 11 ASN.1 Definitions + +-- <<<<<<<<< PDU MESSAGE ELEMENTS >>>>>>>>> + +``` +MRM-PROTOCOL DEFINITIONS AUTOMATIC TAGS ::= -- PART 1 +BEGIN +IMPORTS --Imports from GCC + ChannelID, + StaticChannelID, + DynamicChannelID, + UserID, + TextString, + SimpleNumericString, + SimpleTextFirstCharacter, + SimpleTextLastCharacter, + SimpleTextString, + SimpleNumericString, + DiallingString, + ExtraDiallingString, + SessionKey, + H221NonStandardIdentifier, + SubAddressString, + Key, + Handle, + Password +``` + +FROM GCC-PROTOCOL; + +-- <<<<<<<<< Begin New ASN.1 For MRM >>>>>>>>> + +``` +RosterSequenceNum ::= INTEGER(1..65535) +ParticipantList ::= SET OF UserID +RoomTemplate ::= INTEGER(1..65535) +ServiceProviderID ::= INTEGER(1..65536) +SiteID ::= INTEGER(1..65535) +Template ::= INTEGER(1..65535) +UserServiceHandle ::= INTEGER(1001..65535) +UserRoleHandle ::= INTEGER(1001..65535) +GroupID ::= ChannelID +SourceChannelID ::= INTEGER(0..65535) +RoomKey ::= OCTET STRING(SIZE(0..24)) +``` + +``` +GCCApplicationCapabilities ::= SEQUENCE +{ + nodeType BOOLEAN OPTIONAL, + participantLevel BOOLEAN OPTIONAL, + mediaServices SET OF ENUMERATED + { + pSTNAudio (0), + h323Audio (1), + h324Audio (2), + h323Video (3), + h324Video (4), + audioMixing (5), + videoSwitching (6), + videoStreaming (7), + shadowTopProvider (8), + ... + } OPTIONAL, + ... +} +``` + +**MRMKey ::= CHOICE** + +``` +{ + roomPassword Password, + ... +} +``` + +**MRMFunctions ::= ENUMERATED** + +``` +{ + framework (0), + roster (1), + rooms (2), + groups (3), + services (4), + sessions (5), + permissions (6), + sourceID (7), + privacy (8), + telephony (9), + audioMix (10), + ... +} +``` + +**MRMServiceID ::= CHOICE** + +``` +{ + standardService ENUMERATED + { + audioMixing (0), + ... + }, + userDefinedService UserServiceHandle, + ... +} +``` + +**MRMServiceRequirements ::= SEQUENCE** + +``` +{ + mRMServiceID MRMServiceID, + + requirement ENUMERATED + { + offer (0), -- Advertise capability only + launch (1), -- Launched the service + activate (2), -- Service Launched and made active + -- ready for nodes to subscribe to. + prohibited (3), -- Explicitly prohibit a service + ... + }, + + participationInstructions ENUMERATED + { + mustSubscribe (0), -- applied to all media capable participants + maySubscribe (1), -- applies to all media capable participants + ... + }, + + observerInstructions ENUMERATED + { + mustSubscribe (0), -- applied to all media capable Observers + maySubscribe (1), -- applies to all media capable Observers + subscribeProhibited (2), + ... + }, +} +``` + +``` + + ... +} + +Permission ::= ENUMERATED +{ + toSpeak (0), + toBeSeen (1), + toUseAppShare (2), + toUseWhiteboard (3), + toEnterRoom (4), + ... +} + +T120UserApps ::= ENUMERATED +{ + chat (0), + bFT (1), + whiteboard (2), + appSharing (3), + ... +} + +MRMRole ::= CHOICE +{ + standardRole ENUMERATED + { + chair (0), + operator (1), + groupMember (2), + ... + }, + + userDefinedRoles UserRoleHandle, + + ... +} + +RoomReference ::= SEQUENCE +{ + roomHandle INTEGER(0..65535), + roomConstructorID INTEGER(0..65535), + roomParent INTEGER(0..65535), + roomName SimpleTextString, + roomDescription SimpleTextString, + ... +} + +RoomManagementStyle ::= ENUMERATED +{ + looselyCoupled (0), + informal (1), + semiFormal (2), + formal (3), + ... +} + +RoomManagementRegime ::= ENUMERATED +{ + noChair (0), + chairAvailable (1), + chairActive (2), + ... +} + +``` + +**RoomType ::= ENUMERATED** + +``` +{ + lobby (0), + meetingRoom (1), + presentationRoom (2), + gathering (3), + personalRoom (4), + teamConf (5), + panelConf (6), + ... +} +``` + +**RoomMode ::= ENUMERATED** + +``` +{ + permanent (0), + persistent (1), + dynamic (2), + private (3), + ... +} +``` + +**Media ::= SEQUENCE** + +``` +{ + audioFlg BOOLEAN, + videoFlg BOOLEAN, + dataFlg BOOLEAN, + rTDataFlg BOOLEAN, + ... +} +``` + +**RoomAccessModel ::= ENUMERATED** + +``` +{ + open (0), + controlled (1), + byInvitation (2), + ... +} +``` + +**RoomEntryRegime ::= ENUMERATED** + +``` +{ + direct (0), + byInvitation (1), + viaLobby (2), + viaAutomatedReception (3), + viaDoorKeeper (4), + ... +} +``` + +**RoomExitRegime ::= ENUMERATED** + +``` +{ + exitToPreviousRoom (0), + exitToLobby (1), + exitConference (2), + ... +} +``` + +**RoomState ::= ENUMERATED** + +``` +{ + created (0), + ready (1), + active (2), + suspended (3), + destroyed (4), +} +``` + +``` + + ... +} + +RoomConfig ::= SEQUENCE +{ + roomID ChannelID, + roomsFrameworkID Handle OPTIONAL, + roomMode RoomMode OPTIONAL, + roomManagementModel RoomManagementRegime OPTIONAL, + roomManagementStyle RoomManagementStyle OPTIONAL, + roomType RoomType OPTIONAL, + roomMedia Media OPTIONAL, + roomAccess RoomAccessModel OPTIONAL, + roomEntryRegime RoomEntryRegime OPTIONAL, + roomExitRegime RoomExitRegime OPTIONAL, + roomHierarchy INTEGER(1..8) OPTIONAL, + requiredRoles SET OF MRMRole OPTIONAL, + requiredServices SET OF MRMServiceID OPTIONAL, + roomTemplate Template, + ... +} + +RoomStatus ::= SEQUENCE +{ + roomState RoomState, + numParticipants INTEGER(0..16384), + numObservers INTEGER(0..16384), + activeRoles SET OF MRMRole OPTIONAL, + activeServices SET OF MRMServiceID OPTIONAL, + activeApplications SET OF T120UserApps OPTIONAL, + activeGroups SET OF GroupID OPTIONAL, + ... +} + +RoomTemplatesList ::= SET OF SEQUENCE +{ + roomTemplateID Template, + ... +} + +ConfState ::= ENUMERATED +{ + booked (0), + ready (1), + active (2), + suspended (3), + completed (4), + cancelled (5), + ... +} + +ConfModel ::= ENUMERATED +{ + undefined (0), + formalMeeting (1), + informalMeeting (2), + multiroomConf (3), + broadcastConf (4), + collaboration (5), + gathering (6), + ... +} + +``` + +**ConfConfig ::= SEQUENCE** + +``` +{ + confName SimpleTextString OPTIONAL, + confDescription SimpleTextString OPTIONAL, + confModel ConfModel OPTIONAL, + multisiteFlag BOOLEAN OPTIONAL, + primarySite SiteID OPTIONAL, + slaveSiteList SET SIZE(1..128) OF SiteID OPTIONAL, + maxConventionalNodes INTEGER(0..8192) OPTIONAL, + maxAnonymousNodes INTEGER(0..16384) OPTIONAL, + permittedServicesList SET OF MRMSERVICEID OPTIONAL, + permittedRolesList SET OF MRMRole OPTIONAL, + groupsPermittedFlag BOOLEAN OPTIONAL, + lobbyRequiredFlag BOOLEAN OPTIONAL, + maxRooms INTEGER(1..256) OPTIONAL, + numRoomsDefined INTEGER(1..256) OPTIONAL, + prohibitedPDUsList SET OF MRMPDU OPTIONAL, + ... +} +``` + +**ConfStatus ::= SEQUENCE** + +``` +{ + numParticipants INTEGER(0..16384), + numObservers INTEGER(0..16384), + numRooms INTEGER(1..127), + roomDepth INTEGER(1..15), + roomList SET OF ChannelID, + ... +} +``` + +**UserDetails ::= SEQUENCE** + +``` +{ + mrmUserHandle UserID, + name SimpleTextString , + company SimpleTextString OPTIONAL, + address SimpleTextString OPTIONAL, + e-mail SimpleTextString OPTIONAL, + tel DiallingString OPTIONAL, + fax DiallingString OPTIONAL, + ... +} +``` + +**ConfRosterReporting ::= SEQUENCE** -- Set of flags telling the MRM Top Provider +-- what to include in Conference Roster Reports + +``` +{ + configuration BOOLEAN, + status BOOLEAN, + participantList BOOLEAN, + participantDetails BOOLEAN, + roomTemplates BOOLEAN, + allowRosterEnquiry BOOLEAN, + ... +} +``` + +**RoomRosterReporting ::= SEQUENCE** -- Set of flags telling the MRM Top Provider +-- what to include in Room Roster Reports + +``` +{ + configuration BOOLEAN, + status BOOLEAN, + participantList BOOLEAN, + participantDetails BOOLEAN, +} +``` + +``` + + roomTemplates BOOLEAN, + ... +} + +ServiceCommand ::= ENUMERATED +{ + launch (0), + activate (1), + de-activate (2), + subscribe (3), + ... +} + +ScopeOfRoster ::= ENUMERATED +{ + conference (0), + room (1), + group (2), + individual (3), + ... +} + +-- <<<<<<<<< PART 2 - PDU Messages >>>>>>>>> +-- >>>>>>>>> FRAMEWORK - protocol: 10.6 + +RoomConstructor ::= SEQUENCE +{ + roomConstructorID INTEGER(0..65535), + frameworkRoomID INTEGER(1..65536) OPTIONAL, -- Used if constructor specific to room + roomPurposeDescriptor SimpleTextString OPTIONAL, + roomType RoomType OPTIONAL, + roomMode RoomMode OPTIONAL, + roomState RoomState OPTIONAL, + roomAppearance INTEGER(0..65535) OPTIONAL, -- User defined Template + roomParent INTEGER(0..65535) OPTIONAL, -- Room ID of parent room + roomManagementRegime RoomManagementRegime OPTIONAL, + roomManagementStyle RoomManagementStyle OPTIONAL, + roomAccessModel RoomAccessModel OPTIONAL, + roomEntryRegime RoomEntryRegime OPTIONAL, + roomExitRegime RoomExitRegime OPTIONAL, + childRoomsFlag BOOLEAN OPTIONAL, + maxParticipants INTEGER(1..8192) OPTIONAL, + maxObservers INTEGER(1..16384) OPTIONAL, + participantAccessKey Password OPTIONAL, + observerAccessKey Password OPTIONAL, + groupsPermittedFlag BOOLEAN OPTIONAL, + chairRequiredFlag BOOLEAN OPTIONAL, + chairAccessKey Password OPTIONAL, + presenterRequiredFlag BOOLEAN OPTIONAL, + presenterAccessKey BOOLEAN OPTIONAL, + operatedRequiredFlag BOOLEAN OPTIONAL, + operatorAccessKey Password OPTIONAL, + groupsRequireList SET OF SEQUENCE + { + groupID UserID, + groupAccessKey Password, + ... + } OPTIONAL, + audioOnlySupport BOOLEAN OPTIONAL, + floorControlRequiredFlag BOOLEAN OPTIONAL, + servicesRequirements SET OF MRMServicesRequirements OPTIONAL, + ... +} + +``` + +``` + +AudioMixingService ::= SEQUENCE +{ + serviceConstructorHandle INTEGER(0..65535), + audioMode ENUMERATED + { + mono (0), + stereo (1), + spatial (2), + ... + } OPTIONAL, + maxNumChannelsPerParticipant INTEGER(1..8) OPTIONAL, + maxNumParticipantsPerNode INTEGER(1..512) OPTIONAL, + numMixerPortsInConf INTEGER(3..8192) OPTIONAL, + numAudioInputsRequired INTEGER(2..512) OPTIONAL, + numInterBridgeChannels INTEGER(0..128) OPTIONAL, + startupMode ENUMERATED + { + default (0), + mixAll (1), + manual (2), + ... + } OPTIONAL, + + mixingManagement ENUMERATED + { + central (0), + distributed (1), -- Reserved for future use + manual (2), + ... + } OPTIONAL, + supportedFeaturesList SEQUENCE + { + serviceAnnouncements BOOLEAN, + floorControl BOOLEAN, + stereo BOOLEAN, + spatialAudio BOOLEAN, + surroundSound BOOLEAN, + ... + } OPTIONAL, + ... +} + +FrameworkLoadIndication ::= SEQUENCE +{ + confFramework SEQUENCE + { + newDefaultsFlag BOOLEAN, --Allows Defaults to be changed + originatorId Handle OPTIONAL, + frameworkId Handle OPTIONAL, + confName SimpleTextString OPTIONAL, + confDescription SimpleTextString OPTIONAL, + confModel ConfModel OPTIONAL, + multisiteFlag BOOLEAN OPTIONAL, + maxConventionalNodes INTEGER(0..8192) OPTIONAL, + maxAnonymousNodes INTEGER(0..16384) OPTIONAL, + permittedServicesList SET OF MRMSERVICEID OPTIONAL, + permittedRolesList SET OF MRMRole OPTIONAL, + groupsPermittedFlag BOOLEAN OPTIONAL, + synchDataConfFlag BOOLEAN OPTIONAL, + prohibitedPDUsList SET OF MRMFunctions OPTIONAL, + maxRooms INTEGER(1..256) OPTIONAL, + maxRoomDepth INTEGER(1..8) OPTIONAL, + } +} + +``` + +``` + + numRoomsDefined INTEGER(1..256) OPTIONAL, + partConfRosterReporting BOOLEAN OPTIONAL, + partRoomRosterReporting BOOLEAN OPTIONAL, + obsvrConfRosterReporting BOOLEAN OPTIONAL, + obsvrRoomRosterReporting BOOLEAN OPTIONAL, + roomList SET SIZE(0..255) OF RoomReference, + roomConstructorList SET SIZE(0..255) OF RoomConstructor, + ... + }, + ... +} + +``` + +-- >>>>>>>>> *ROSTER - protocol link: 10.7* + +**RosterReportIndication ::= SEQUENCE** + +``` + +{ + rosterSequenceNum INTEGER (1..65535), + scopeOfReport ScopeOfRoster, + confConfig ConfConfig OPTIONAL, + confStatus ConfStatus OPTIONAL, + confParticipantList SET OF UserID OPTIONAL, + roomConfig RoomConfig OPTIONAL, + roomStatus RoomStatus OPTIONAL, + roomParticipantsList SET OF UserID OPTIONAL, + participantDetails UserDetails OPTIONAL, + ... +} + +``` + +**RosterUpdateIndication ::= SEQUENCE** + +``` + +{ + rosterSequenceNum INTEGER (1..65535), + confConfig ConfConfig OPTIONAL, + confStatus ConfStatus OPTIONAL, + confParticipantList SET OF UserID OPTIONAL, + roomConfig RoomConfig OPTIONAL, + roomStatus RoomStatus OPTIONAL, + roomParticipantsList SET OF UserID OPTIONAL, + participantDetails UserDetails OPTIONAL, + ... +} + +``` + +**RosterEnquireIndication ::= SEQUENCE** + +``` + +{ + scopeOfEnquire ScopeOfRoster, + detailFlag BOOLEAN, + channel ChannelID, + configurationFlag BOOLEAN, + statusFlag BOOLEAN, + participantListFlag BOOLEAN, + participantDetailsFlag BOOLEAN, + roomTemplatesFlag BOOLEAN, + ... +} + +``` + +-- >>>>>>>>> *ROOMS - protocol: 10.8* + +**RoomCreateRequest ::= SEQUENCE** + +``` + +{ + roomID ChannelID OPTIONAL, + roomOwnerFlag BOOLEAN, + roomParent INTEGER(1..65535) OPTIONAL, + frameworkRoomID INTEGER(1..65535) OPTIONAL, + roomTemplateFlag BOOLEAN, +} + +``` + +``` + +roomTemplateID INTEGER(1..65535) OPTIONAL, + +roomConfig SEQUENCE +{ + roomMode RoomMode OPTIONAL, + roomMedia Media OPTIONAL, + roomAccess RoomAccessModel OPTIONAL, + roomEntryRegime RoomEntryRegime OPTIONAL, + receptionRooms SET OF ChannelID OPTIONAL, + roomExitRegime RoomExitRegime OPTIONAL, + roomName SimpleTextString OPTIONAL, + roomPurpose SimpleTextString OPTIONAL, + numberOfParticipants INTEGER(0..16383) OPTIONAL, + numberOfObservers INTEGER(0..16383) OPTIONAL, + +``` + +``` + + requiredRolesList SEQUENCE + +``` + +``` + + { + role MRMRole, + ... + } OPTIONAL, + +``` + +``` + + requiredServicesList SEQUENCE + +``` + +``` + + { + service MRMServiceID, + ... + }, + ... + +``` + +``` + +}, +... +} + +``` + +**RoomCreateResponse ::= SEQUENCE** + +``` + +{ + roomID ChannelID, + roomMasterKey RoomKey, + result ENUMERATED + { + successful (0), + roomDepthExceeded (1), + maxRoomsExceeded (2), + prohibitedByFramework (3), + notAuthorized (4), + invalidParameter (5), + invalidParentID (6), + outOfMCSResources (7), + ... + }, + ... +} + +``` + +**RoomEnterRequest ::= SEQUENCE** + +``` + +{ + enterRoomID ChannelID, + currentRoomID ChannelID, + suspendFlag BOOLEAN, + participationType ENUMERATED + { + participant (0), + observer (1), + ... + }, + roomAccessKey RoomKey OPTIONAL, + reasonEntering SimpleTextString, + +``` + +``` + + ... +} + +RoomEnterResponse ::= SEQUENCE +{ + destRoomID ChannelID, + roomAccessKey RoomKey OPTIONAL, + channelToJoin ChannelID OPTIONAL, + reasonEntering SimpleTextString, + + result ENUMERATED + { + successful (0), + privateRoom (1), + gotoSpecifiedRoom (2), + invalidRoomID (3), + roomLimitsExceeded (4), + notAuthorized (5), + ... + }, + ... +} + +``` + +``` + +RoomInviteIndication ::= SEQUENCE +{ + roomID ChannelID, -- Also used as coms channel for room + roomKey MRMKey, + invitedNodeList SET OF UserID, + invitingNodeID UserID, + reasonstring SimpleTextString, + ... +} + +``` + +-- >>>>>>>>> GROUPS - protocol: 10.8.4 + +``` + +GroupCreateRequest ::= SEQUENCE +{ + groupOwner UserID, + groupScopeFlag BOOLEAN, + roomID ChannelID OPTIONAL, + groupName SimpleTextString, + groupFunction SimpleTextString, + orderFlag BOOLEAN, + memberList SET OF UserID OPTIONAL, + ... +} + +``` + +``` + +GroupCreateResponse ::= SEQUENCE +{ + roomID ChannelID, + groupHandle ChannelID, + result ENUMERATED + { + success (0), + failed (1), + ... + }, + ... +} + +``` + +**GroupDisbandRequest ::= SEQUENCE** + +``` +{ + groupOwner UserID, + roomID ChannelID, + groupHandle ChannelID, + ... +} +``` + +**GroupDisbandResponse ::= SEQUENCE** + +``` +{ + groupHandle ChannelID, + result ENUMERATED + { + successful (0), + notGroupOwner (1), + invalidGroupID (2), + notAuthorized (3), + ... + }, + ... +} +``` + +**GroupMemberSpecifyRequest ::= SEQUENCE** + +``` +{ + groupIdentifier UserID, + addMemberList SET OF UserID, + removememberList SET OF UserID, + specifyMemberList SET OF UserID, + ... +} +``` + +**GroupMemberSpecifyResponse ::= SEQUENCE** + +``` +{ + groupIdentifier ChannelID, + result ENUMERATED + { + successful (0), + notAuthorized (1), + invalidGroupID (2), + ... + }, + ... +} +``` + +-- >>>>>>>>> *SESSION ASSOCIATION - protocol: 10.9* + +**SessionAssociateRequest ::= SEQUENCE** + +``` +{ + roomId ChannelID, + associatedDataSessions SET OF SessionKey, + ... +} +``` + +**SessionAssociateResponse ::= SEQUENCE** + +``` +{ + result ENUMERATED + { + successful (0), + notAuthorized (1), + ... + }, +} +``` + +``` + + ... +} +-- >>>>>>>>> ROLES - protocol:9.9.2.1 + +RoomRoleAssignRequest ::= SEQUENCE +{ + requesterUserID UserID, + roleHolderUserID UserID, + roomID ChannelID, + roomRole MRMRole, + roleLabel SimpleTextString, + roleAccessKey MRMKey, + groupID GroupID, + ... +} + +``` + +``` + +RoomRoleAssignResponse ::= SEQUENCE +{ + roomID ChannelID, + roomRole MRMRole, + result ENUMERATED + { + successful (0), + roleNotPermitted (1), + roleAlreadyAssigned (2), + invalidRoleKey (3), + ... + }, + ... +} + +``` + +``` + +RoomRoleReleaseRequest ::= SEQUENCE +{ + roomID ChannelID, + roleHolderID UserID, + role MRMRole, + groupID ChannelID, + releaseReason SimpleTextString, + ... +} + +``` + +``` + +RoomRoleReleaseResponse ::= SEQUENCE +{ + roomID ChannelID, + roomRole MRMRole, + result ENUMERATED + { + successful (0), + notRoleHolder (1), + invalidRoom (2), + invalidGroup (3), + ... + }, + ... +} + +``` + +``` + +RoomRoleReleaseIndication ::= SEQUENCE +{ + roomID ChannelID, + roleHolderID UserID, + role MRMRole, + groupID ChannelID, + releaseReason SimpleTextString, + +``` + +``` + + ... +} + +RoomRolePleaseRequest ::= SEQUENCE +{ + requesterID UserID, + roomID ChannelID, + roomRole MRMRole, + groupID ChannelID, + ... +} + +``` + +``` + +RoomRoleGiveRequest ::= SEQUENCE +{ + roleHolderID ChannelID, + recipientID ChannelID, + roomID ChannelID, + roomRole MRMRole, + groupID ChannelID, + ... +} + +``` + +``` + +RoomRoleGiveResponse ::= SEQUENCE +{ + roomID ChannelID, + roomRole MRMRole, + groupID ChannelID, + result ENUMERATED + { + successful (0), + notRoleHolder (1), + ... + }, + ... +} + +``` + +``` + +RoomRoleGiveIndication ::= SEQUENCE +{ + roleGiver UserID, + roleRecipient UserID, + roomID ChannelID, + roomRole MRMRole, + groupID ChannelID, + ... +} + +``` + +``` + +RolePermissionsModifyRequest ::= SEQUENCE +{ + requestingNodeID UserID, + createRole BOOLEAN, + passRole BOOLEAN, + askforRoleFlag BOOLEAN, + modifyRolePermissions BOOLEAN, + modifyotherRoles BOOLEAN, + roomCreationRights BOOLEAN, + roomInheritance BOOLEAN, + groupModification BOOLEAN, + groupOrdering BOOLEAN, + requestPermission BOOLEAN, + operateFloorControl BOOLEAN, + inviteEjectParticipants BOOLEAN, + +``` + +``` + + viewDataApps BOOLEAN, + controlDataApps BOOLEAN, + viewSpecificApp SessionKey, + controlSpecificApp SessionKey, + controlAudioMix BOOLEAN, + controlAudioDevices BOOLEAN, + inviteAudioParticipants BOOLEAN, + mutable BOOLEAN, + controlVideoDevices BOOLEAN, + ... + } + +``` + +**RolePermissionsModifyResponse ::= SEQUENCE** + +``` + +{ + result ENUMERATED + { + success (0), + failed (1), + ... + }, + ... +} + +``` + +-- >>>>>>>>> *PERMISSIONS - protocol: 10.11* + +**PermissionAskRequest ::= SEQUENCE** + +``` + +{ + requestingID UserID, + roomID ChannelID, + releaseReason SimpleTextString, + permission Permission, + privateRoomID ChannelID, -- Room in which to process request + groupRequest ChannelID, + associatedService MRMSERVICEID, + ... +} + +``` + +**PermissionRelinquishRequest ::= SEQUENCE** + +``` + +{ + requestingID UserID, + releaseReason SimpleTextString, + permission Permission, + roomID ChannelID, + groupPermission BOOLEAN, + associatedService MRMSERVICEID, + ... +} + +``` + +**PermissionGrantRequest ::= SEQUENCE** + +``` + +{ + roomID ChannelID, + permissionGranted Permission, + groupGrant BOOLEAN, + associatedService MRMSERVICEID, + accessCap ENUMERATED + { + shared (0), + exclusive (1), + ... + }, + ... +} + +``` + +-- >>>>>>>>> *SOURCE IDENTIFICATION - protocol: 10.12* + +**SourceHandle ::= SEQUENCE** + +``` +{ + mRMChannel UserID, + mediaPipeTag INTEGER(0..1023), + ... +} +``` + +-- MRM User ID of node providing source +-- extension tag to distinguish +-- between different sources + +**SourceIdentificationRequest ::= SEQUENCE** + +``` +{ + sourceHandle SourceHandle, + sourceChannelId ChannelID, + mediatype Media, + roomID ChannelID, + streamDescriptor SimpleTextString, + reasonCode SimpleTextString, + ... +} +``` + +-- >>>>>>>>> *ON-AIR INDICATION - protocol: 10.13* + +**OnAirIndicationRequest ::= SEQUENCE** + +``` +{ + mediaChannelID ChannelID, + sourceHandle SourceHandle, + roomID ChannelID, + onAirFlag BOOLEAN, + ... +} +``` + +-- >>>>>>>>> *PRIVACY - protocol: 10.13.1* + +**PrivacyNotifyRequest ::= SEQUENCE** + +``` +{ + sourceHandle SourceHandle, + roomID ChannelID, + mediaChannelId ChannelID, + mediatype Media, + remotePrivacy BOOLEAN, + privacyStatus BOOLEAN, + ... +} +``` + +**PrivacyNotifyResponse ::= SEQUENCE** + +``` +{ + sourceHandle UserID, + roomID ChannelID, + mediaChannel ChannelID OPTIONAL, + privacyStatus BOOLEAN, + ... +} +``` + +-- >>>>>>>>> *SERVICE COMMAND - protocol: 10.14* + +**ServiceCommandRequest ::= SEQUENCE** + +``` +{ + requestingNode UserID, + roomID UserID, + +``` + +``` + +command ENUMERATED +{ + launch (0), + subscribe (1), + unSubscribe (2), + terminate (3), + ... +}, + +service ENUMERATED +{ + audioMix (0), + ... +}, + +mode ENUMERATED +{ + default (0), + ... +}, +... +} + +``` + +``` + +ServiceCommandResponse ::= SEQUENCE +{ + requestingNode UserID, + result ENUMERATED + { + successful (0), + notPermitted (1), + ... + }, + ... +} + +``` + +-- > *AUDIO MIXER - protocol: 10.15* + +``` + +AudioMixReportRequest ::= SEQUENCE +{ + userID UserID, + roomID ChannelID, + newSpkrUsr UserID, + newspkrDev Handle, + prevSpkrUsr UserID, + prevSpkrDev Handle, + nodelist SEQUENCE OF UserID, + activeSpkrList SEQUENCE OF UserID, + ... +} + +``` + +``` + +AudioMixSetRequest ::= SEQUENCE +{ + requester UserID, + roomID ChannelID, + mixingMode ENUMERATED + { + default (0), + ... + }, + addAudioStreamList SET OF Handle, + enableAudioStreamList SET OF Handle, + muteAudioStreamList SET OF Handle, + +``` + +``` + + removeAudioStreamList SET OF Handle, + audioLevelAdjust SEQUENCE +{ + scope ChannelID, + abslevel INTEGER(0..100) OPTIONAL, + uplevel INTEGER(0..100) OPTIONAL, + downlevel INTEGER(0..100) OPTIONAL, + ... +}, +... +} + +``` + +**AudioMixSetResponse ::= SEQUENCE** + +``` + +{ + result ENUMERATED + { + success (0), + ... + }, + ... +} + +``` + +**InviteAudioOnlyNodeRequest ::= SEQUENCE** + +``` + +{ + roomID ChannelID, + communicationAddress CHOICE + { + phoneNum SEQUENCE + { + countryCode DiallingString, + number DiallingString, + extension DiallingString, + ... + }, + ipAddress SubAddressString, + ... + }, + roomAccessKey RoomKey, + invitationReason SimpleTextString, + entryMethod ENUMERATED + { + direct (0), + viaSideConf (1), + ... + }, + ... +} + +``` + +**InviteAudioOnlyNodeResponse ::= SEQUENCE** + +``` + +{ + result ENUMERATED + { + success (0), + noReply (1), + failed (2), + ... + }, + ... +} + +``` + +**EjectAudioOnlyNodeRequest ::= SEQUENCE** + +``` +{ + roomID ChannelID, + communicationAddress CHOICE + { + phoneNum SET OF SEQUENCE + { + countryCode DiallingString, + number DiallingString, + extension DiallingString + }, + dialstring ExtraDiallingString, + iPAddress SubAddressString, + ... + }, + nont120UserID UserID, + ... +} +``` + +**EjectAudioOnlyNodeResponse ::= SEQUENCE** + +``` +{ + result ENUMERATED + { + success (0), + invalidUserID (1), + notAuthorized (2), + ... + } +} +``` + +**CallStatusIndication ::= SEQUENCE** + +``` +{ + roomID ChannelID, + nont120UserID UserID, + status ENUMERATED + { + dialling (0), + engaged (1), + nU (2), + noReply (3), + answered (4), + mixed (5), + ... + } +} +``` + +-- <<<<<<<<< PART 3 - Messages Sent using MCS-Send-Data >>>>>>>>> + +**MRMPDU ::= CHOICE** + +``` +{ + request RequestPDU, + response ResponsePDU, + indication IndicationPDU, + ... +} +``` + +**RequestPDU ::= CHOICE** + +``` +{ + roomCreateRequest RoomCreateRequest, + roomEnterRequest RoomEnterRequest, + sessionAssociateRequest SessionAssociateRequest, + groupCreateRequest GroupCreateRequest, + groupDisbandRequest GroupDisbandRequest, + groupMemberSpecifyRequest GroupMemberSpecifyRequest, + serviceCommandRequest ServiceCommandRequest, + roomRoleAssignRequest RoomRoleAssignRequest, + roomRoleReleaseRequest RoomRoleReleaseRequest, + roomRolePleaseRequest RoomRolePleaseRequest, + roomRoleGiveRequest RoomRoleGiveRequest, + rolePermissionsModifyRequest RolePermissionsModifyRequest, + permissionAskRequest PermissionAskRequest, + permissionRelinquishRequest PermissionRelinquishRequest, + permissionGrantRequest PermissionGrantRequest, + sourceIdentificationRequest SourceIdentificationRequest, + onAirIndicationRequest OnAirIndicationRequest, + privacyNotifyRequest PrivacyNotifyRequest, + audioMixReportRequest AudioMixReportRequest, + audioMixSetRequest AudioMixSetRequest, + inviteAudioOnlyNodeRequest InviteAudioOnlyNodeRequest, + ejectAudioOnlyNodeRequest EjectAudioOnlyNodeRequest, + ... +} +``` + +**ResponsePDU ::= CHOICE** + +``` +{ + roomCreateResponse RoomCreateResponse, + roomEnterResponse RoomEnterResponse, + sessionAssociateResponse SessionAssociateResponse, + groupCreateResponse GroupCreateResponse, + groupDisbandResponse GroupDisbandResponse, + groupMemberSpecifyResponse GroupMemberSpecifyResponse, + serviceCommandResponse ServiceCommandResponse, + roomRoleAssignResponse RoomRoleAssignResponse, + roomRoleReleaseResponse RoomRoleReleaseResponse, + roomRoleGiveResponse RoomRoleGiveResponse, + rolePermissionsModifyResponse RolePermissionsModifyResponse, + privacyNotifyResponse PrivacyNotifyResponse, + audioMixSetResponse AudioMixSetResponse, + inviteAudioOnlyNodeResponse InviteAudioOnlyNodeResponse, + ejectAudioOnlyNodeResponse EjectAudioOnlyNodeResponse, + ... +} +``` + +**IndicationPDU ::= CHOICE** + +``` +{ + frameworkLoadIndication FrameworkLoadIndication, + rosterReportIndication RosterReportIndication, + rosterUpdateIndication RosterUpdateIndication, + rosterEnquireIndication RosterEnquireIndication, + roomInviteIndication RoomInviteIndication, + roomRoleGiveIndication RoomRoleGiveIndication, + callStatusIndication CallStatusIndication, + ... +} +``` + +**END** + +-- <<<<<<<<< *END ASN.1* >>>>>>>> + +# 12 Requirements for running MRM + +### 12.1 Summary of GCC services required by MRM + +MRM assumes the services listed in the GCC primitives in Table 84. Primitives endorsed with an "M" are mandatory, those marked with an "O" are optional. + +**Table 84/T.137 – GCC primitives supported by MRM** + +| GCC Primitive | Use | +|------------------------------------------------|-----| +| GCC-Application-Permission-To-Enrol indication | M | +| GCC-Application-Enrol request | M | +| GCC-Application-Enrol confirm | M | +| GCC-Application-Roster-Report indication | M | + +NOTE – MRM Terminals should ignore MRM Application capabilities for network elements; they are not needed by them. + +## 12.2 Summary of use of the Multipoint Communication Service + +All MRM communication shall be through the Multipoint Communication Service (MCS) as specified in Recommendation T.122. This subclause details how MRM makes use of MCS services, channel allocation, token allocation and data priorities. + +### 12.2.1 MCS services + +MRM assumes the MCS services indicated in Table 85. All primitives and parameters marked with an "M" are used by mandatory components of MRM. Items marked with an "O" are optional, and not required for MRM operation. + +**Table 85/T.137 – MCS services used by MRM** + +| Primitives | Terminal use | Network Element use | +|--------------------------------|--------------|---------------------| +| MCS-Attach-User request | M | M | +| MCS-Attach-User confirm | M | M | +| MCS-Detach-User request | M | M | +| MCS-Detach-User indication | M | M | +| MCS-Channel-Join request | M | M | +| MCS-Channel-Join confirm | M | M | +| MCS-Channel-Leave request | M | M | +| MCS-Channel-Leave indication | M | M | +| MCS-Channel-Convvene request | O | M | +| MCS-Channel-Convvene confirm | O | M | +| MCS-Channel-Disband request | – | M | +| MCS-Channel-Disband indication | – | M | +| MCS-Channel-Admit request | – | M | +| MCS-Channel-Admit indication | – | M | + +**Table 85/T.137 – MCS services used by MRM (*concluded*)** + +| Primitives | Terminal use | Network Element use | +|----------------------------------|--------------|---------------------| +| MCS-Channel-Expel request | – | M | +| MCS-Channel-Expel indication | – | M | +| MCS-Send-Data request | M | M | +| MCS-Send-Data indication | M | M | +| MCS-Uniform-Send-Data request | O | O | +| MCS-Uniform-Send-Data indication | O | O | +| MCS-Token-Grab request | – | M | +| MCS-Token-Grab confirm | – | M | +| MCS-Token-Release request | – | M | +| MCS-Token-Release confirm | – | M | + +### 12.2.2 MCS channels used by MRM + +See Table 86. + +**Table 86/T.137 – MCS channel assignments for MRM** + +| Channel ID | Type | Mnemonic | Description | +|---------------|---------|--------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| MRM-Channel-1 | Static | MRM-Conference-Management-Channel | Joined by the MRM top provider; it may also be joined by other nodes that wish to shadow the top provider. Used by terminals to communicate with the MRM top provider. | +| MRM-Channel-2 | Static | MRM-Conference-Communication-Channel | Joined by all terminals that take part in the MRM Conference. Used by the MRM top provider to distribute the MRM Conference Roster. | +| MRM-Channel-3 | Static | MRM-Default-Room-Participant Channel | The Default Room channel used as the identifier for the default room and joined by MRM Participants. | +| MRM-Channel-4 | Static | MRM-Default-Room-Observer Channel | | +| | Dynamic | MRM-Room-Participant-Channel | Used as the Room Identifier and joined by MRM participants. | +| | Dynamic | MRM-Room-Observer Channel | The channel that is allocated when an MRM Room is to accommodate MRM observers. It should be joined by Observers entering the room instead of the MRM-Room-Participant-Channel. | +| | Dynamic | MRM-Group-Membership Channel | This channel is allocated when an MRM Group is created it is used as the group identifier. | + +### 12.2.3 MCS Tokens used by MRM + +See Table 87. + +**Table 87/T.137 – MCS token assignments for MRM** + +| Token ID | Type | Mnemonic | Description | +|-----------------|-------------|------------------------|----------------------| +| MRM-Token 0 | Static | MRM-Top-provider-Token | MCS Token – Optional | + +### 12.2.4 Encoding of PDUs in MCS primitives + +All PDUs defined in this Recommendation are encoded and placed in the data field of one of the MCS-Send-Data primitives. The bit string that results from the ASN.1 encoding is placed in the OCTET STRING used by MCS in the order such that for each octet the leading bit is placed in the most significant bit position, and the trailing bit is placed in the least significant bit position. + + + + + +# ITU-T RECOMMENDATIONS SERIES + +| | | +|-----------------|--------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of the ITU-T | +| Series B | Means of expression: definitions, symbols, classification | +| Series C | General telecommunication statistics | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks and open system communications | +| Series Y | Global information infrastructure and Internet protocol aspects | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.150-198811-I_PDF-E/raw.md b/marked/T/T-REC-T.150-198811-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..70ac0bbb8b0445830f95c4e3630ce13e7bff5385 --- /dev/null +++ b/marked/T/T-REC-T.150-198811-I_PDF-E/raw.md @@ -0,0 +1,2134 @@ + + +![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## T.150 + +**TERMINAL EQUIPMENT AND PROTOCOLS FOR +TELEMATIC SERVICES** + +--- + +**TELEWRITING TERMINAL EQUIPMENT** + +**ITU-T Recommendation T.150** + +(Extract from the *Blue Book*) + +--- + +# NOTES + +- 1 ITU-T Recommendation T.150 was published in Fascicle VII.5 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below). +- 2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +© ITU 1988, 1993 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +# **TELEWRITING TERMINAL EQUIPMENT** + +## **TABLE OF CONTENTS** + +This Recommendation consists of four parts, combined in one document + +## **SCOPE** + +## **PART 1 – *Fundamental characteristics*** + +- 1 Introduction +- 2 Definitions +- 3 References +- 4 Presentation functionalities +- 5 Principles of telewriting coding + +## **PART 2 – *Telewriting together with telephony*** + +- 1 General +- 2 Main characteristics of the basic terminal +- 3 Presentation functionalities of the basic terminal +- 4 Transmission for the basic terminal +- 5 Transmission blocks +- 6 Transmission procedure +- 7 Coding identifier +- 8 Communication control, general requirements +- 9 Communication control commands +- 10 Description of the communication process + +## **PART 3 – *Zone coding*** + +- 1 General +- 2 Presentation elements +- 3 Zone coding description +- 4 Specification of terms used in coding +- 5 Specification of the coding +- 6 A coding example +- 7 Data structure +- 8 Temporary pen-stop +- 9 Control commands +- 10 Summary code table +- 11 Summary transmission data format +- 12 Zone coding basic terminal + +## PART 4 – *Differential chain coding* + +- 1 General +- 2 Presentation elements +- 3 Description of the coding +- 4 Incremental mode mechanism +- 5 Change of coding parameters +- 6 Coding formats +- 7 Incremental mode coding format +- 8 Displacement mode coding format +- 9 Encoding of the primitives +- 10 Example of differential chain coding + +## 1 Scope + +This Recommendation specifies technique-oriented characteristics of telewriting and the application of telewriting in combination with voice communication. Service-oriented requirements are defined in Recommendation F.730. In the development of this Recommendation, compatibility with other telematic services is taken into account. This Recommendation is structured in four parts: + +Part 1 – Fundamental characteristics + +Part 2 – Telewriting together with telephony + +Part 3 – Zone coding + +Part 4 – Differential chain coding. + +## **Part 1 - Fundamental characteristics** + +### 1 Introduction + +1.1 Telewriting is a communication technique that enables the exchange of handwritten information through telecommunication means. The handwritten information may consist of text in handwriting, drawings, diagrams, etc. + +1.2 By means of telewriting terminal equipment, the TRACE of the writing instrument as produced at the sending side, is reproduced at the receiving side including the effect of movement. + +1.3 In the sending part of the terminal the handwritten input information is converted into a digital signal: the coded representation of the handwritten information. Next, this digital signal is converted into a signal suitable for transmission. + +1.4 In the receiving part of the terminal the received signal is converted into a digital signal, corresponding with the coded representation as described in above. From this digital signal, the handwritten information is reproduced. + +1.5 The reproduction of the handwritten information can take place on a screen, on paper or both. In this Recommendation, the characteristics of communication through telewriting are defined with respect to the image on a screen (soft copy). Reproduction on paper (hard copy) is considered to be an optional function under local control. + +1.6 Storage may take place between the writing (the input process) and the reproduction (the output process). When retrieved from a store, the message will appear on the receiver's screen in the same way as in the case of a direct connection. + +1.7 A page of handwritten information (or part of it) could be reproduced as a still picture. This application, however, is not covered in the present text. + +- 1.8 Telewriting can be used in various ways: +- as independent communication technique, + - in combination with voice communication through a telephone network, + - in the context of teleconferencing, + - in the context of information retrieval. + +### **2 Definitions** + +#### **2.1 telewriting image** + +A collection of telewriting presentation elements, to be displayed together. + +*Note* – The telewriting image can exist in visible form at the output device, or in the form of a coded representation. + +#### **2.2 presentation element** + +Basic graphic element used to construct an image. + +Examples of telewriting presentation elements are: trace, closed area, background. + +#### **2.3 coding rectangle** + +Rectangular area representing the coding space in horizontal and vertical direction, available for coding of a telewriting image. + +#### **2.4 image area** + +(previously: text area) + +Rectangular part of the display area, to be considered as the image of the coding rectangle. + +#### **2.5 background** + +Presentation element being a rectangular area with the same size as the image area, acting as a reference area on which telewriting foreground information can be presented. + +#### **2.6 trace** + +Presentation element being a curve of an arbitrary shape, starting from a defined position, being completed incrementally and ending at a defined position. + +#### **2.7 closed area** + +Presentation element being an area enclosed within one trace which constitutes a closed line. + +#### **2.8 marker** + +Marked representation of a single position in a telewriting image. + +*Note* – A marker is not a permanent part of a telewriting image, but exists only as long as it is activated. + +#### **2.9 attribute** + +A particular property which applies to a presentation element or to a group of presentation elements. + +Examples: line thickness, colour. + +### 3 References + +In the text of this Recommendation the following Recommendations/standards are referred to: + +- Rec. F.730: Service oriented requirements for telewriting applications. +- Rec. T.101: International interworking for videotex services; Annex C, data syntax II. +- Rec. V.21: 300 bits per second duplex modem standardized for use in the general switched telephone network. +- ISO 9281: Information processing – Identification of picture coding methods. + +### 4 Presentation functionalities + +4.1 This section describes a set of presentation functionalities. This set of functionalities is intended as a repertoire of presentation functionalities for telewriting in general. For a specific application a subset may be defined. + +4.2 In the description of presentation functionalities, the concept of TRACE is being used. A trace is a curve of an arbitrary shape, starting from a defined position, being completed incrementally and ending at a defined position. Handwritten information is considered to consist of traces. + +4.3 Representation of the handwritten information is accomplished by the sequential reconstruction of the individual traces. This implies that the effect of movement is retained during each reproduction. + +4.4 Telewriting information is to be displayed on the display area of some output device. The display area is considered to be a two-dimensional surface. + +4.5 The display area is subdivided into an image area and a border area; see Figure 1-1/T.150. + +![Diagram showing the subdivision of a display area into an image area and a border area.](5d76c2e9976aaf97001ee189908830fb_img.jpg) + +The diagram consists of two concentric rectangles. The inner rectangle is labeled 'Image area'. The outer rectangle is labeled 'Border area' on its right side. The space between the two rectangles represents the border area surrounding the image area. + +Diagram showing the subdivision of a display area into an image area and a border area. + +FIGURE 1-1/T.150 + +**Subdivision of display area** + +4.6 The border area surrounds the image area. External form and dimensions of the border area are not specified. The presence of a border area is not mandatory. It is however inevitable in certain implementations. + +4.7 The image area is rectangular. The two shorter edges of the image area have a vertical orientation, the two longer edges have a horizontal orientation. The length ratio of shorter and longer edges is 3:4. + +- 4.8 The position of telewriting information on the display area is defined with respect to the edges of the image area. +- 4.9 Information on the display area is composed of presentation elements of three categories: +- foreground, + - background, + - border area. +- 4.10 Foreground and background presentation elements are defined in the image area only. +- Border area presentation elements are defined in the border area only. The use of the border area is not defined for telewriting. +- 4.11 Foreground presentation elements include trace, marker and closed area. +- 4.12 The presentation elements have the following characteristics: +- *Trace*: This is the curve as defined in § 2.6 of this part; the essence of the handwritten information is represented by one trace or by any combination of traces; the image area can contain an undefined number of traces at a time. + - *Marker*: This is a marked representation of a single position; it behaves as if it is overlaid on the foreground; a moving marker does not create a trace; a marker can be switched on and off; one user can generate only one marker at a time. The image area can contain one locally generated marker and one remotely generated marker. + - *Closed area*: This is the area that is enclosed within a closed trace; this closed trace is the perimeter. A trace is a closed trace if it intersects itself; a trace that is nearly closed can be converted into a closed trace, by the addition of the lacking part of the trace. + - *Background*: The background is a defined reference area on which foreground information is to be imaged; if the full image area is filled with foreground information, the background is not visible. + - *Border area*: The border area is independent of the information in the image area. +- In case of a CRT display the border area is the remaining part between image area and edges of the display area. +- In case of a cell-structured display device, the image area may coincide exactly with the display area. In that case no border area remains. +- 4.13 The various presentation elements can have attributes assigned to them as defined in Table 1-1/T.150. + +TABLE 1-1/T.150 + +#### **Attributes of telewriting presentation elements** + +| Presentation element | Attributes | +|----------------------|------------------------------------------------------------------------------------------------| +| Trace | Line thickness, line texture, colour | +| Marker | Shape, size, colour | +| Closed area | Area texture, colour (interaction or area attributes with background attributes to be defined) | +| Background | Area texture, colour | +| Border area | Not defined | + +*Note* – The concept of colour includes “intensity”. + +4.14 Once an image is displayed, subsequent modification of attributes is restricted as follows: + +- trace: attributes unchangeable; +- marker: attributes can be changed at any instant; +- closed area: attributes unchangeable; +- background: attributes can be changed at any instant. + +4.15 In case of intersection of two traces, the image of the older trace is interrupted as far as it coincides with the newer trace. + +4.16 In case of intersection of a trace and a marker, the image of the trace is interrupted as far as it coincides with the marker. After removal of the marker, the image of the original trace is restored. + +4.17 With respect to erasure of foreground information, a distinction is made regarding the area in which erasure takes place: + +- full image area; +- defined part of the image area; +- individual traces. + +4.18 *Erasure of the full image area* + +All foreground information in the image area is removed; the background assumes a pre-defined appearance. + +4.19 *Erasure of a defined part of the image area* + +An area is identified either by means of a closed trace or as a defined square, within which all foreground information is to be removed including the perimeter itself. + +4.20 *Erasure of individual traces* + +An existing trace is covered by a thicker trace with the same attributes as the background: this type of erasure is processed in the same way as a trace. + +4.21 Any modification of background information can take place for the full image area only. + +### **5 Principles of telewriting coding** + +5.1 Telewriting coding relates to coding of telewriting information in foreground and background and to erasure functions. + +5.2 This section contains principles of telewriting coding. In Parts 3 and 4, details of telewriting coding are defined for two methods, namely zone coding and differential chain coding, respectively. + +5.3 The coding is defined at the “telewriting coding interface”, TCI. This interface is introduced for ease of reference, but need not exist physically. + +5.4 In the sending part of the telewriting terminal, the signal at the TCI contains all data originating from handwritten input, selection of attributes and use of erasure functions. + +5.5 The signals at the TCI, both in sending and receiving parts, do not contain data pertaining to transmission or communication functions. + +5.6 In the receiving part of the telewriting terminal, the signal at the TCI contains all data required to image the information in accordance with the intentions of the originator. + +5.7 The concept of the TCI is illustrated in Figure 1-2/T.150. + +![Block diagram of the Telewriting coding interface (TCI) showing the flow from Writing attributes erasure to Coding, then through TCI to Comm. ctl & transm. functions, then through a Network, then through another Comm. ctl & transm. functions, then through TCI to De-coding, and finally to Display.](acfc53eca625d62b38aa2563efa95c3e_img.jpg) + +``` +graph LR; A[Writing attributes erasure] --> B[Coding]; B -- TCI --> C[Comm. ctl & transm. functions]; C --> D[Network]; D --> E[Comm. ctl & transm. functions]; E -- TCI --> F[De-coding]; F --> G[Display]; +``` + +T0803750-89 + +Block diagram of the Telewriting coding interface (TCI) showing the flow from Writing attributes erasure to Coding, then through TCI to Comm. ctl & transm. functions, then through a Network, then through another Comm. ctl & transm. functions, then through TCI to De-coding, and finally to Display. + +FIGURE 1-2/T.150 +**Telewriting coding interface, TCI** + +5.8 The signal at the TCI includes x and y coordinate information regarding telewriting presentation elements. + +5.9 The x and y coordinates are related to a unit area of $1 \times 1$ . This implies that the respective values of x and y always lie between 0 and 1 (0 included, 1 not included). + +5.10 The origin of the coordinate system is in the lower left corner. The x-axis is horizontal, the y-axis is vertical. + +5.11 The horizontal size of the telewriting image area corresponds with $x = 1$ , the vertical size of this image area corresponds with $y = 0.75$ . See Figure 1-3/T.150. + +![Diagram showing the position of the image area within a unit area. The unit area is a square with coordinates (0,0) at the bottom-left and (1,1) at the top-right. The image area is a rectangle within this square, extending from x=0 to x=1 and from y=0 to y=0.75.](0b87abe67b21a93777287649c33e755d_img.jpg) + +Diagram illustrating the position of the image area within a unit area. The unit area is a square with coordinates (0,0) at the bottom-left and (1,1) at the top-right. The image area is a rectangle within this square, extending from x=0 to x=1 and from y=0 to y=0.75. + +Diagram showing the position of the image area within a unit area. The unit area is a square with coordinates (0,0) at the bottom-left and (1,1) at the top-right. The image area is a rectangle within this square, extending from x=0 to x=1 and from y=0 to y=0.75. + +FIGURE 1-3/T.150 +**Position of image area within unit area** + +5.12 All coordinates of the telewriting information are quantized relative to a measurement grid in the unit area. The resolution of this grid determines the accuracy. + +5.13 The default resolution is $512 \times 512$ grid units. The telewriting coding can optionally also accommodate grid resolutions of $1024 \times 1024$ and $2048 \times 2048$ grid units. + +## **Part 2 - Telewriting together with telephony** + +### **1 General** + +- 1.1 This part of the Recommendation defines the use of telewriting in combination with voice communication through a telephone network (PSTN). +- 1.2 For this application, both sides of the connection must have a combined telephone and telewriting terminal. +- 1.3 The combined telephone and telewriting terminal should, as long as the telewriting transmission function is switched off, behave like a normal telephone set, both for incoming and outgoing calls. In this situation, the full bandwidth is available for transmission of speech signals. +- 1.4 During a telephone conversation, the telewriting transmission function at either side of the connection, may be switched on and off, manually or automatically. +- 1.5 Remark that in this part of the Recommendation “switching on and off” of the telewriting function refers to the telewriting transmission functions. Regardless of this, the telewriting equipment may be used locally, whether or not a telephone connection exists. +- 1.6 By means of the telewriting terminal, the user can generate information. This includes: creation of traces, marker switching on and off, movement of the marker, use of erasure functions. +- 1.7 In this part, distinction is made between “basic terminal” and “enhanced terminal”. +- 1.8 The enhanced terminal is not defined yet, but compared to the basic terminal it is anticipated to have additional capabilities regarding unattended operation, transmission facilities and presentation functionalities. + +### **2 Main characteristics of the basic terminal** + +- 2.1 In this section, a basic terminal is defined. +- In the basic terminal a set of functions is implemented that is to be considered as a minimum requirement; thus a basic level of compatibility is defined. +- 2.2 A basic terminal includes a telephone apparatus, a writing device and a display device. Circuitry to implement control functions may be accommodated in a separate unit or may be included in one of the devices mentioned. +- 2.3 Information generated at either side of the connection will be reproduced on the display devices at both sides of the connection. +- 2.4 Both sides of the connection can contribute, one after another, to the same image. +- 2.5 In the basic terminal, transmission of telewriting signals is accomplished through a sub-channel, segregated from the speech channel. Transmission of speech signals and telewriting signals can take place simultaneously. +- 2.6 Half-duplex transmission is used for conveying the telewriting signals through the sub-channel, i.e. the transmitter is prevented from sending as long as the associated receiver receives telewriting signals from the other side. +- 2.7 The total power level of speech plus telewriting signals should conform to the limits normally applicable to speech transmission and data transmission. +- 2.8 The basic terminal can assume three modes of operation. The characteristics pertinent to each mode, are described in Table 2-1/T.150. + +TABLE 2-1/T.150 + +#### **Modes of operation of the basic terminal** + +| | | +|-------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Speech only | The telewriting function remains in the OFF condition. | +| Speech plus telewriting | The telewriting function can be switched ON after the establishment of a connection. Speech signals and telewriting signals can be sent simultaneously. | +| Telewriting only | This mode can be switched ON after the establishment of a connection. The sending of speech signals is blocked, the power level of the telewriting signals is increased correspondingly. Reception of speech signals is still possible. | + +2.9 In this Recommendation, the expression “telewriting ON” is used as a common indication for either “speech plus telewriting” or “telewriting only”. + +2.10 A basic terminal may be able to continue transmission and reception of telewriting signals after termination of the human conversation. In this case, the telewriting transmission function will be switched OFF automatically after completion of the telewriting transmission. (Defined in more detail later on.) + +2.11 For the coding of telewriting information, two methods are recognized for use at the sending side: tone coding (defined in Part 3) and differential chain coding (defined in Part 4). + +At the receiving side, the basic terminal should be able to properly accept telewriting signals coded according to either method. + +### **3 Presentation functionalities of the basic terminal** + +3.1 The general description of presentation functionalities, as given in Part 1, § 4, applies. + +With respect to this general description certain restrictions apply, as defined in the following points. + +3.2 The presentation functionalities as described for the basic terminal are to be regarded as default capabilities. + +If required, characteristics of terminals with a higher level of sophistication will be described in a section on enhanced terminal. + +3.3 The basic terminal employs a monochrome display device. The writing device generates coded representations of monochrome images only. + +3.4 The attributes applying to the basic terminal are given in Table 2-2/T.150. + +TABLE 2-2/T.150 + +#### **Attributes applying to the basic terminal** + +| Presentation elements | Attributes | +|-----------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Image size | Horizontal: 512 GU
Vertical: $0.75 \times 512$ GU
Options, the receiver must be able to accept:
Horizontal: 1024 and 2048 GU
Vertical: $0.75 \times 1024$ and $0.75 \times 2048$ GU. | +| Trace | | +| – thickness | Unit thickness, as used in the output device.
Options: $2 \times$ and $3 \times$ unit thickness. | +| – texture | Solid, no options. | +| – colour | Monochrome, as used in the output device. The receiver must be able to accept the codes of traces with colours: red, green, blue, yellow, magenta, cyan, white, black. A black trace has the same colour as the background (used for erasure). | +| Closed area | | +| – texture | Solid. | +| – colour | Same as background colour (used only for partial erasure). The receiver must be able to accept the codes of closed areas with colours: red, green, blue, yellow, magenta, cyan, white, black. | +| Background | | +| – texture/colour | No information about the background is transmitted. Background can only be imagined as dark screen. This corresponds with colour black. | +| Border area | Border area is not specified, no information about the border area is transmitted. | +| Marker | | +| – shape | PLUS sign; other shapes may be possible depending on terminal implementation. | +| – size | Not specified. | +| – colour | Marker colour is not transmitted; on a monochrome device the marker appears in foreground colour; on a colour device the marker may assume a colour under local control. | +| Full erasure | Black background is restored. | +| Partial erasure | 1) closed area;
2) overwriting with thicker black trace. | + +GU Grid units + +### **4 Transmission for the basic terminal** + +4.1 Transmission of the modulated telewriting signal takes place in a small frequency band, segregated from the speech channel. This band is referred to as the sub-channel. + +4.2 The centre of the sub-channel is located at 1750 Hz. Details of the implementation are not given here, but the requirements of §§ 4.6 and 4.7 should be met. + +- 4.3 The binary telewriting signal is converted into a signal suitable for transmission, by means of frequency shift modulation. Details are the same as those specified in Recommendation V.21 for channel 2 (the high channel). +- 4.4 The modulation rate is 300 Bd, the bit rate is 300 bit/s. +- 4.5 The V.21 requirements for channel 2 are summarized as follows: The nominal mean frequency of the transmission signal is 1750 Hz. The frequency deviation is + or – 100 Hz. Consequently, the nominal characteristic frequencies are 1850 Hz and 1650 Hz respectively. The higher frequency corresponds to a binary 0. +- 4.6 The amount of speech signal power that can reach the local and remote telewriting receivers, should be sufficiently low to avoid errors in the demodulated telewriting signal. +- 4.7 The amount of telewriting signal power that can reach the local and remote telephone receivers (i.e. the loudspeaker part) should be sufficiently low to avoid disturbance of the conversation. +- 4.8 In the mode of operation “telewriting only”, the output power of the telewriting transmitter shall be in accordance with the requirements described in Recommendation V.21. +- 4.9 In the mode of operation “speech plus telewriting”, the modulated Telewriting signal should be attenuated by 4 dB with regard to the level determined by § 4.8. If experience shows that also the power of the speech signal should be adapted, relevant requirements will be included in the next issue of this Recommendation. +- 4.10 In the case of long-distance communication an echo suppressor may be present in the link. This will hamper the “speech plus telewriting” mode. Since, generally, disabling of the echo suppressor cannot be guaranteed to solve the problem, it is recommended to use the “telewriting only” mode, alternating with the “speech only” mode. +- 4.11 The telewriting data as well as communication control commands are structured in 8-bit bytes. +For transmission, each byte is packed in an 11-bit transmission word as defined below. +- 4.12 The structure of each transmission word is as follows: +1 startbit, binary value ZERO +8 bits representing telewriting or control data +1 parity bit +stopbit, binary value ONE. +This structure is illustrated in Figure 2-0/T.150. + +![](4e4be0bd8b235167902f2c03e41da651_img.jpg) + +| | | | | +|--------------|---------------|---------------|--------------| +| Start | Data | Parity | Stop | +| 1 bit | 8 bits | 1 bit | 1 bit | + +**FIGURE 2-0/T.150** +**Structure of a transmission word** + +- 4.13 For the value of the parity bit, EVEN parity applies. This Recommendation does not specify any action for the basic terminal in case of reception of an erroneous parity bit. +- 4.14 The transmission words are conveyed in start-stop mode, i.e. the pause following a transmission word until the occurrence of the next transmission word, may in principle have any duration. However, the bits constituting the transmission word should be transmitted as a contiguous sequence at the appropriate bit rate. +- 4.15 In addition to its task of transporting bits, the data send signal may assume one of three possible states: +- MARK signal: a binary ONE condition, with a duration significantly longer than a bit period. + - SPACE signal: a binary ZERO condition; this condition is not used in the framework of this Recommendation. + - Carrier OFF: no send signal present. + +### 5 Transmission blocks + +5.1 To define the transmission structure, the concept of transmission block is introduced. In the general case, a transmission block contains transmission words and MARK signals. However, also transmission blocks containing MARK signals only may occur. + +5.2 The beginning of a transmission block is identified by the occurrence of one out of two defined combinations of MARK signal and carrier OFF condition, referred to as start combination No. 1 and start combination No. 2. + +5.3 The start combinations are defined as follows: + +- start combination No. 1 carrier OFF during at least 130 ms, followed by MARK signal of $100 \pm 20$ ms followed by carrier OFF during $100 \pm 20$ ms followed by MARK signal of $200 \pm 20$ ms. +- start combination No. 2 carrier OFF during at least 130 ms, followed by MARK signal of $400 \pm 20$ ms. + +See illustration in Figure 2-1/T.150. + +The use of these start combinations is defined later. + +![Figure 2-1/T.150: Start combinations. The diagram illustrates two start combinations for a transmission block. The top sequence shows 'Previous data' followed by 'Carrier OFF > 130 ms', then a 'MARK 100 ± 20 ms' signal, followed by 'Carrier OFF 100 ± 20 ms', then a 'MARK 200 ± 20 ms' signal, and finally 'Further data'. A bracket below this sequence labels it as 'Start combination No. 1'. The bottom sequence shows 'Previous data' followed by 'Carrier OFF > 130 ms', then a single 'MARK 400 ± 20 ms' signal, and finally 'Further data'. A bracket below this sequence labels it as 'Start combination No. 2'.](16c1175b5f05a4b55e6d396fc51b15b3_img.jpg) + +T0803760-89 + +Figure 2-1/T.150: Start combinations. The diagram illustrates two start combinations for a transmission block. The top sequence shows 'Previous data' followed by 'Carrier OFF > 130 ms', then a 'MARK 100 ± 20 ms' signal, followed by 'Carrier OFF 100 ± 20 ms', then a 'MARK 200 ± 20 ms' signal, and finally 'Further data'. A bracket below this sequence labels it as 'Start combination No. 1'. The bottom sequence shows 'Previous data' followed by 'Carrier OFF > 130 ms', then a single 'MARK 400 ± 20 ms' signal, and finally 'Further data'. A bracket below this sequence labels it as 'Start combination No. 2'. + +**FIGURE 2-1/T.150** +**Start combinations** + +5.4 Immediately following the start combination of a transmission block, one of the following signals should be sent: + +- a MARK signal +- a single transmission word +- a sequence of transmission words. + +Between any two subsequent transmission words, a MARK signal may occur, representing a pause in the writing process. + +5.5 Every transmission block is terminated by a MARK signal of $500 \pm 20$ ms. The MARK signal is to be followed by a carrier OFF condition of at least 130 ms. + +5.6 The MARK signals representing pauses may have various durations, determined as follows: + +- during PEN DOWN and absence of other telewriting activity, the MARK signal may continue without limitation; +- after PEN UP the terminal will apply a limit of $500 \pm 20$ ms. Within this limit the telewriting activity may continue without procedural steps. If the limit expires, the carrier will be switched OFF. Thus the transmission block is automatically terminated by the terminal. Sending of further data requires the start of a new transmission block. + +- 5.7 The periods between transmission blocks are indicated by carrier OFF conditions. +- 5.8 The formats of transmission blocks are summarized in Figure 2-2/T.150. + +![](bd0b93e7a46ede276d0a3b79ac487bd9_img.jpg) + +| | | | | | | +|---------------|-------------|-------------------|-------------------------------------|------|-------------| +| Previous data | Carrier OFF | Start combination | Transmission words and MARK signals | MARK | Carrier OFF | +|---------------|-------------|-------------------|-------------------------------------|------|-------------| + +T0803770-49 + +FIGURE 2-2/T.150 + +**Transmission block format, summarized** + +### 6 Transmission procedure + +6.1 Prior to actually sending telewriting data, the terminal is to decide whether it functions in MASTER mode or in SLAVE mode. + +In case of a transmission collision, the master terminal has transmission privilege over slave terminals. + +6.2 The terminal decides about the master/slave status by sending the start combination No. 1 and observing the received signal. + +6.3 If the terminal, engaged in sending start combination No. 1, detects a received carrier signal at its receiver input (during a carrier OFF interval) it decides to be a slave and it postpones further attempts to send data. See Figure 2-3/T.150. + +6.4 If the terminal does not detect a received carrier signal during the sending of the start combination, it decides to be a master and continues sending. See Figure 2-3/T.150. + +6.5 In the case that only one terminal generates telewriting data, this terminal assumes the master status. The receiving terminal remains in the slave status. + +6.6 As a header for the subsequent transmission blocks, a master terminal uses start combination No. 2, a slave terminal uses start combination No. 1. See Figure 2-4/T.150. + +6.7 The master/slave status decision in a given terminal remains valid until it is cancelled as follows: + +- A master terminal becomes a slave if it is not engaged in sending at the moment that another terminal sends start combination No. 1. +- A slave terminal becomes a master terminal at the moment that it sends a start combination No. 1 and no receive carrier signals are being detected. +- A master status is cancelled by “telewriting OFF”. + +![Flowchart for MASTER/SLAVE status decision procedure](fa859e4e468bfb2710a94527f2c504af_img.jpg) + +``` + + graph TD + Start([Start]) --> P1[Switching ON] + P1 -- 1 --> P2[Assume SLAVE status] + P2 -- 2 --> D3{Receive carrier detected?} + D3 -- Yes --> P12[Stay in SLAVE status] + D3 -- No --> D4{HW activity occurs?} + D4 -- No --> D3 + D4 -- Yes --> P5[Switch transmit carrier ON] + P5 -- 5 --> D6{T1 elapsed?} + D6 -- No --> D6 + D6 -- Yes --> P7[Switch transmit carrier OFF] + P7 -- 7 --> D8{Receive carrier detected?} + D8 -- Yes --> P12 + D8 -- No --> D9{T2 elapsed?} + D9 -- No --> D8 + D9 -- Yes --> P10[Switch transmit carrier ON] + P10 -- 10 --> D11{T3 elapsed?} + D11 -- No --> D11 + D11 -- Yes --> P13[Assume MASTER status +Continue sending] + +``` + +Flowchart for MASTER/SLAVE status decision procedure + +**Timers** + +| | | +|----|-------------| +| T1 | 100 ± 20 ms | +| T2 | 100 ± 20 ms | +| T3 | 200 ± 20 ms | + +FIGURE 2-3/T.150 +**MASTER/SLAVE status decision procedure** + +16 Fascicle VII.5 - Rec. T.150 + +![Flowcharts for master and slave transmission start procedures. The master flowchart starts with 'Start (master)', goes to 'Telewriting ON Receive ready', checks 'TW activity occurring?'. If 'No', it loops back. If 'Yes', it checks 'Receive carrier detected?'. If 'Yes', it loops back. If 'No', it sends a MARK signal for 400 ± 20 ms and then sends data. The slave flowchart starts with 'Start (slave)', goes to 'Telewriting ON Receive ready', checks 'TW activity occurring?'. If 'No', it loops back. If 'Yes', it checks 'Receive carrier detected?'. If 'Yes', it loops back. If 'No', it sends a MARK signal for 100 ± 20 ms, then goes to 'Receive ready'. It then checks 'Receive carrier detected?'. If 'Yes', it loops back to 'Receive ready'. If 'No', it checks 'T elapsed?'. If 'Yes', it sends a MARK signal for 200 ± 20 ms and then sends data. If 'No', it loops back to 'Receive ready'. A timer block specifies T = 100 ± 20 ms.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg) + +``` + +graph TD + subgraph Master_Flowchart [Master Flowchart] + StartMaster([Start master]) --> TelewritingMaster[Telewriting ON +Receive ready] + TelewritingMaster --> TWActivityMaster{TW activity +occurring?} + TWActivityMaster -- No --> TelewritingMaster + TWActivityMaster -- Yes --> ReceiveCarrierMaster{Receive carrier +detected?} + ReceiveCarrierMaster -- Yes --> TelewritingMaster + ReceiveCarrierMaster -- No --> SendMarkMaster[Send MARK signal +during 400 ± 20 ms] + SendMarkMaster --> SendDataMaster[Send data] + end + + subgraph Slave_Flowchart [Slave Flowchart] + StartSlave([Start slave]) --> TelewritingSlave[Telewriting ON +Receive ready] + TelewritingSlave --> TWActivitySlave{TW activity +occurring?} + TWActivitySlave -- No --> TelewritingSlave + TWActivitySlave -- Yes --> ReceiveCarrierSlave{Receive carrier +detected?} + ReceiveCarrierSlave -- Yes --> TelewritingSlave + ReceiveCarrierSlave -- No --> SendMarkSlave1[Send MARK signal +during 100 ± 20 ms] + SendMarkSlave1 --> ReceiveReadySlave[Receive ready] + ReceiveReadySlave --> ReceiveCarrierSlave2{Receive carrier +detected?} + ReceiveCarrierSlave2 -- Yes --> ReceiveReadySlave + ReceiveCarrierSlave2 -- No --> TElapsedSlave{T elapsed?} + TElapsedSlave -- No --> ReceiveReadySlave + TElapsedSlave -- Yes --> SendMarkSlave2[Send MARK signal +during 200 ± 20 ms] + SendMarkSlave2 --> SendDataSlave[Send data] + end + +``` + +Timer + +--- + +$T = 100 \pm 20 \text{ ms}$ + +T0803790-89 + +Flowcharts for master and slave transmission start procedures. The master flowchart starts with 'Start (master)', goes to 'Telewriting ON Receive ready', checks 'TW activity occurring?'. If 'No', it loops back. If 'Yes', it checks 'Receive carrier detected?'. If 'Yes', it loops back. If 'No', it sends a MARK signal for 400 ± 20 ms and then sends data. The slave flowchart starts with 'Start (slave)', goes to 'Telewriting ON Receive ready', checks 'TW activity occurring?'. If 'No', it loops back. If 'Yes', it checks 'Receive carrier detected?'. If 'Yes', it loops back. If 'No', it sends a MARK signal for 100 ± 20 ms, then goes to 'Receive ready'. It then checks 'Receive carrier detected?'. If 'Yes', it loops back to 'Receive ready'. If 'No', it checks 'T elapsed?'. If 'Yes', it sends a MARK signal for 200 ± 20 ms and then sends data. If 'No', it loops back to 'Receive ready'. A timer block specifies T = 100 ± 20 ms. + +FIGURE 2-4/T.150 +**Transmission start for master and slave respectively** + +### 7 Coding identifier + +7.1 In the communication control procedures, the existing of two coding methods is recognized, i.e. zone coding and differential chain coding respectively. + +The method actually used is identified by the coding identifier PCE. (PCE = picture control entity). + +A terminal receiving signals according to either method will be able to activate the appropriate decoding function, by recognizing the coding identifier. + +7.2 The coding identifier is structured according to ISO 9281. In this standard, the coding identifier PCE is defined to comprise a picture coding delimiter (PCD) and a coding method identifier (CMI). See Figure 2-5/T.150. + +![Diagram showing the structure of the coding identifier PCE. It is a rectangle divided into two equal horizontal sections. The left section is labeled 'PCD' and the right section is labeled 'CMI'.](9cd90f495b95ad2116ff780248c26d95_img.jpg) + +| | | +|-----|-----| +| PCD | CMI | +|-----|-----| + +Diagram showing the structure of the coding identifier PCE. It is a rectangle divided into two equal horizontal sections. The left section is labeled 'PCD' and the right section is labeled 'CMI'. + +PCE + +**PCE** Picture control entity + +**PCD** Picture coding delimiter + +**CMI** Coding method identifier + +**FIGURE 2-5/T.150** + +**Structure of coding identifier** + +7.3 (Copy of ISO 9281, § 6.2.4 modified) + +The PCD shall announce or delimit the data for a particular picture coding method. The PCD shall comprise the two-byte sequence 01/11, 07/00. + +7.4 (Copy of ISO 9281, § 6.2.5) + +The CMI shall specify the particular coding method for the picture data that follow it. The CMI may consist of one or more octets corresponding to the bit combinations in the range 02/00 to 07/14 of an 8-bit code table. + +7.5 (Copy of ISO 9281, § 6.2.6) + +Each CMI identifying a particular picture coding method shall be registered with the ISO Registration Authority for Picture Coding Methods (to be set up). + +7.6 The telewriting coding identifier, when included in a transmission block, occupies the first three (or more if appropriate) transmission words following the start combination. See Figure 2-6/T.150. + +![](7f25db95ce3916c0e09803b861a2f7bc_img.jpg) + +| | | | | | | +|-------------|-------------------|-------------------|-----------------------------------|------|-------------| +| Carrier OFF | Start combination | Coding identifier | Telewriting data and MARK signals | MARK | Carrier OFF | +|-------------|-------------------|-------------------|-----------------------------------|------|-------------| + +FIGURE 2-6/T.150 + +#### **Transmission format, including coding identifier** + +7.7 In a point-to-point configuration, the inclusion of the coding identifier in the first transmission block only, would in principle be sufficient for the whole session. + +However, for multipoint communication, the insertion of the coding identifier in each transmission block is required. + +In view of this requirement, it is recommended that the coding identifier be included in each transmission block containing telewriting data, irrespective of the configuration. + +7.8 The terminal should be designed such that transmission of the coding identifier takes place automatically at the right moment. + +7.9 For telewriting equipment according to this Recommendation T.150 the following bit combinations should be used in the coding identifier. See Table 2-3/T.150. + +TABLE 2-3/T.150 + +#### **Coding identifier bit combinations** + +| Acronym | Bit combination | +|-----------------------|-----------------| +| PCD (2 byte sequence) | 01/11, 07/00 | +| CMI Zone coding | 02/00, 04/00 | +| CMI Diff-chain coding | 02/00, 04/01 | + +Note —The above allocations are of a preliminary nature, pending further development of ISO 9281. + +### 8 Communication control, general requirements + +8.1 This section defines requirements for the control of data exchange for the basic telewriting terminal. + +8.2 These requirements also apply to data exchange between any enhanced terminal and a basic terminal. + +8.3 The requirements permit the use of a two-hop satellite circuit in the connection between two terminals. + +8.4 The requirements also permit multi-point communication via a voice bridge. + +8.5 Establishment and clearing of the telephone connection take place in accordance with the requirements set by the telephone network. + +8.6 For the basic terminal, automatic calling and answering are not defined. + +8.7 A basic terminal may, as an option, be equipped such that it can maintain the exchange of telewriting data after termination of the speech conversation. This option is identified as “automatic call termination”. + +8.8 The automatic call termination implies that the telewriting function (sending as well as receiving) is able to operate autonomously while the telephone apparatus is in the ON HOOK condition. + +8.9 To enable automatic call termination, the terminal must be able: + +- to note that sending respectively reception of a telewriting transmission block is going on, during the ON HOOK condition of the telephone apparatus, +- to recognize the end of the final telewriting transmission block, +- to switch back to the speech only mode and to clear the telephone connection. + +8.10 Switching between the three modes “speech only”, “speech plus telewriting” and “telewriting only” can be done manually. In addition, switching the telewriting function OFF can take place automatically by means of the communication control command SSO in the transmission signal. The transitions between modes of operation are illustrated in Figure 2-7/T.150. + +![Diagram illustrating transitions between modes of operation: Speech only, Speech plus telewriting, and Telewriting only.](2eb23c2210154279f8013a1594fbcc5a_img.jpg) + +``` +graph TD; + A[Speech only] -- "Via control command" --> B[Speech plus telewriting]; + B -- "Manual" --> A; + A -- "Manual" --> C[Telewriting only]; + C -- "Manual" --> A; + B -- "Manual" --> C; + C -- "Via control command" --> A; + B <--> C; +``` + +The diagram shows three rectangular boxes representing operational modes: 'Speech only' on the left, 'Speech plus telewriting' at the top right, and 'Telewriting only' at the bottom right. Transitions are indicated by arrows with labels. A 'Via control command' arrow points from 'Speech only' to 'Speech plus telewriting'. A 'Manual' arrow points from 'Speech plus telewriting' back to 'Speech only'. A 'Manual' arrow points from 'Speech only' to 'Telewriting only'. A 'Manual' arrow points from 'Telewriting only' back to 'Speech only'. A 'Manual' arrow points from 'Speech plus telewriting' to 'Telewriting only'. A 'Via control command' arrow points from 'Telewriting only' back to 'Speech only'. A double-headed vertical arrow labeled 'Manual' connects 'Speech plus telewriting' and 'Telewriting only'. + +T0803800-89 + +Diagram illustrating transitions between modes of operation: Speech only, Speech plus telewriting, and Telewriting only. + +FIGURE 2-7/T.150 + +**Transitions between modes of operation** + +### 9 Communication control commands + +9.1 For control of the communication process, the commands SSO and HLO are available. + +The coding of these commands is as follows: + +SSO 1/7 + +HLO 0/5 + +The meaning of these commands is described in Table 2-4/T.150. + +TABLE 2-4/T.150 + +#### **Communication control commands** + +| Acronym | Meaning | +|---------|-----------------------------------------------------------------------------------------------------------------------------------| +| SSO | Set speech only
This command indicates that the terminals are instructed to switch from telewriting ON to the speech only mode | +| HLO | Hello
This command is to be sent by a terminal that expects telewriting data, but does not receive such data | + +9.2 A terminal will automatically send SSO upon the instruction by its local user, to switch over from the telewriting ON mode to the speech only mode. + +Transmission of SSO can take place in two ways: + +- At the end of the current transmission block. SSO is attached to the block, according to the format defined below. +- By means of a separate transmission block. Such a block is sent specifically for conveying SSO. Format: defined below. + +9.3 A terminal receiving SSO will revert to the speech only mode and does not recognize further telewriting signals. + +9.4 The format for sending SSO is defined in Figures 2-8/T.150 and 2-9/T.150. + +![](75e4b78ee25f885d73120e3066a5253e_img.jpg) + +**For zone coding** + +| | | | | | | | | +|-------------------|----------|-----------------------|------|-----|------|------|-------------| +| Start combination | PCE (ZC) | Telewriting data (ZC) | 1/15 | SSO | 1/15 | MARK | Carrier OFF | +|-------------------|----------|-----------------------|------|-----|------|------|-------------| + +**For differential chain coding** + +| | | | | | | +|-------------------|-----------|------------------------|-----|------|-------------| +| Start combination | PCE (DCC) | Telewriting data (DCC) | SSO | MARK | Carrier OFF | +|-------------------|-----------|------------------------|-----|------|-------------| + +T0803810-89 + +FIGURE 2-8/T.150 + +#### **Transmission block containing telewriting data and SSO** + +![](e69b9188aa2c14ec6b21c83f711fef65_img.jpg) + +For zone coding + +| | | | | | | | +|-------------------|----------|------|-----|------|------|-------------| +| Start combination | PCE (ZC) | 1/15 | SSO | 1/15 | MARK | Carrier OFF | +|-------------------|----------|------|-----|------|------|-------------| + +--- + +For differential chain coding + +| | | | | | +|-------------------|-----------|-----|------|-------------| +| Start combination | PCE (DCC) | SSO | MARK | Carrier OFF | +|-------------------|-----------|-----|------|-------------| + +--- + +T0803820-89 + +FIGURE 2-9/T.150 +Transmission block containing SSO only + +9.5 The HLO command will only be sent in a block without telewriting data. The format should be as defined in Figure 2-10/T.150. + +![](09955ff8214ffb6947951fc0f60eb6ab_img.jpg) + +For zone coding + +| | | | | | | | +|-------------------|----------|------|-----|------|------|-------------| +| Start combination | PCE (ZC) | 1/15 | HLO | 1/15 | MARK | Carrier OFF | +|-------------------|----------|------|-----|------|------|-------------| + +--- + +For differential chain coding + +| | | | | | +|-------------------|-----------|-----|------|-------------| +| Start combination | PCE (DCC) | HLO | MARK | Carrier OFF | +|-------------------|-----------|-----|------|-------------| + +--- + +T0803830-89 + +FIGURE 2-10/T.150 +Transmission block containing HLO only + +9.6 The HLO command is intended for use with automatic reception. This command will be sent by a terminal if it has not received valid telewriting data during a period of 35 seconds since: + +- establishment of the telephone call; +- reception of the last valid transmission block. + +9.7 The terminal receiving a HLO command responds with a MARK signal of $700 \pm 20$ ms. + +9.8 A terminal in the telewriting ON condition, receiving signals other than valid telewriting data (e.g. a tone from the telephone network) cannot enter the send mode. In this case, the terminal returns to the speech only mode without sending any command or other information (after a guard-time of 35 seconds). + +### 10 Description of the communication process + +10.1 In order to describe the full communication process, the concepts of “telewriting activity” and “telewriting session” are introduced. These are defined as follows: + +- **Telewriting activity** – Any action by the user that causes the telewriting terminal (in the telewriting ON condition), to send data. Examples of such actions are: pen down, marker ON, erasure. +- **Telewriting session** – A period of time delimited by session start and session end, during which two communicating terminals have a relationship that enables them to exchange telewriting data. + +- 10.2 The event determining session start is: +- the terminals are in the condition telewriting ON, + - at one of the terminals the first telewriting activity has occurred. +- 10.3 The event determining session end is: +- the terminals switch over to the telewriting OFF condition. +- 10.4 The session is established as soon as the coding identifier is received and recognized by the receiving terminal. +- 10.5 At the beginning of the session, both terminals have the slave status. During the session, only one terminal at a time can acquire the master status. +- 10.6 In the preceding text of this Part 2, all elements to be used in the communication process are defined now. +- The process can be summarized as described in Table 2-5/T.150. +- 10.7 The preceding description is given for a point-to-point configuration. However, taking into account that only one terminal can have the master status, this description is applicable to a multipoint configuration as well. In this case it is indispensable that every transmission block contain a coding identifier. + +TABLE 2-5/T.150 + +#### **Communication process summarized** + +| | | +|--------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Step 1 | Both parties agree by speech to switch to the telewriting ON condition. | +| Step 2 | Following telewriting ON, each terminal is in the receive ready condition, i.e. the receiver is ON but it does not receive telewriting signals. | +| Step 3 | The first telewriting activity occurring at one of the terminals causes that terminal to initiate the transmission of the first transmission block. | +| Step 4 | The terminal initiating the transmission of the first transmission block assumes the master status. | +| Step 5 | The session is established as soon as the receiving terminal has received and recognized the coding identifier contained in the first transmission block. | +| Step 6 | Within the session, each terminal may alternately assume send, receive and receive ready conditions, as required by human actions and/or received signals. When appropriate, the master status will be taken over by another terminal, as defined in the section on transmission procedures. | +| Step 7 | In case of a transmission collision, the terminal with master status is permitted to continue sending; a terminal with slave status has to await a new opportunity. | +| Step 8 | The session is terminated when the terminals switch to the telewriting OFF condition. | + +## Part 3 - Zone coding + +### 1 General + +- 1.1 This part of the Recommendation defines details of the zone coding method. +- 1.2 For an application of zone coding together with telephony the combined requirements from Parts 1, 2 and 3 apply. +- 1.3 This part also specifies how the coded signal is to be structured in 8 bit bytes, in order to fit in the transmission words defined in Part 2. +- 1.4 In the writing pad, the beginning of a stroke of handwriting is recognized by the detection of the pen-down condition. +- 1.5 Each stroke generates a set of time serial coordinate pairs during pen-down. +- 1.6 The coordinates of handwriting during pen-down are sampled at a fixed rate of 40 samples/second. +- 1.7 The first sampling is initiated by pen-down, and continues, ending when the pen is lifted. +- 1.8 The sequence of coordinate pairs is converted into a coded representation according to the zone coding rules. After this conversion the stroke is represented by the presentation element TRACE. +- 1.9 The presentation elements are coded in the form of opcodes and operands. +- 1.10 The opcodes have a fixed 8-bit length; the operands have a variable length. +- 1.11 The telewriting coordinate information is contained in the operands. + +### 2 Presentation elements + +- 2.1 In tone coding, the following presentation elements are distinguished: + - trace + - marker + - partial erasure + - untrace + - set colour + - line thickness + - complete erasure.These elements and the format of the associated command streams are defined in Table 3-1/T.150. +- 2.2 The opcodes are defined in Table 3-2/T.150 (notation x/y means column x, row y, in a $16 \times 16$ code table). + +### 3 Zone coding description + +- 3.1 A trace is coded as a sequence of vectors (vector = D). +- 3.2 The beginning of a trace is the starting point of the first vector. +- 3.3 The end point of a vector constitutes the starting point for the next vector in the trace. +- 3.4 The starting point position of the first vector of each trace is coded in the form of a pair of absolute coordinates. +- 3.5 The position of each endpoint is determined by means of a measurement system, the origin of which must coincide with the starting point of the vector. +- 3.6 Within this measurement system, the endpoint position is found through a three step approximation: + - step 1: the quadrant $\theta$ , one value out of four; see Figure 3-1/T.150; + - step 2: the zone k within the quadrant; for division and numbering, see Figure 3-2/T.150; + - step 3: the relative address A within the zone. + +- 3.7 In the coded representation, the quadrant and zone are indicated in a differential way: dθ and dk. +- 3.8 A set of 30 combinations of dθ and dk are selected to be coded in a compressed form, see Table 3-3/T.150. +- 3.9 The relative address within the zone has a length depending upon the size of the zone. +- 3.10 A vector end point position of which the combination dθ and dk is not defined in Table 3-3/T.150 is coded by EFZ (escape from zone code) followed by the absolute address. +- 3.11 The end of a trace is indicated by PLI (pen lift indicator) following the last (relative or absolute) address. +- 3.12 The zone coding is defined more precisely in §§ 4 and 5. An example of this coding is given in § 6. + +### **4 Definitions of terms used in coding** + +- 4.1 The vector $D_i$ defined by: + +$$\begin{aligned} D_i &= P_i - P_{i-1} \\ &= (dx_i, dy_i) = (x_i - x_{i-1}, y_i - y_{i-1}) \end{aligned}$$ + +where $P_i$ is the $i$ -th coordinate pair during pen-down. + +TABLE 3-1/T.150 + +#### **Presentation element commands** + +| | | +|---------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Trace TRn |
  • – The TRn command draws line segments that are defined by a co-ordinate information operand.
  • – The TRn command stream is:
    ISP, TRn, ... co-ordinate information ... ISP.
| +| Marker MKn |
  • – The MKn command draws a marker pattern, the center of which is specified by a co-ordinate information operand.
  • – The MKn command stream is:
    ISP, MKn, ... co-ordinate information ... ISP.
| +| Partial Erasure PEn |
  • – The PEn command erases the closed area defined by a co-ordinate information operand.
  • – The PEn command stream is:
    ISP, PEn, ... co-ordinate information ... ISP.
| +| Untrace UTn |
  • – The UTn command erases the square area (with its sides parallel to the sides of the unit area) the centre of which is specified by a co-ordinate operand.
  • – The size of the square is defined as follows:
    (32 \times 2^{n-9} - 1) \times (32 \times 2^{n-9} - 1) grid units.
  • – The UTn ... command stream is:
    ISP, UTn ... co-ordinate information ... ISP.
| +| Set Colour SC* |
  • – The SC* command sets a colour attribute to a particular trace. The colour attribute* can be set at the values:
    • * = R: red                      * = B: blue
    • * = G: green                  * = M: magenta
    • * = Y: yellow                * = C: cyan
    • * = W: white
  • – The effect of an SC* command remains valid until the next SC* or CE command.
  • – The SC* command stream is:
    ISP, SC*, ISP, TRn, ... co-ordinate information ... ISP.
| +| Line Thickness LT* |
  • – The LT* command sets a line thickness that is defined by *, as follows:
    • * = 1: one grid unit width,
    • * = 2: two grid units width,
    • * = 3: three grid units width.
  • – The effect of LT* command remains valid until the next LT* or CE command.
  • – The LT* command stream is:
    ISP, LT*, ISP, TRn, ... co-ordinate information ... ISP.
| +| Complete Erasure CE |
  • – The displayed image is erased completely.
  • – The CE command is:
    ISP, CE, ISP.
| + +n        determines the grid resolution, + +n = 9    means: grid resolution = $512 \times 512$ (default value), + +n = 10   means: grid resolution = $1024 \times 1024$ , + +n = 11   means: grid resolution = $2048 \times 2048$ , + +ISP     Information Separator. + +TABLE 3-2/T.150 + +#### **Zone coding presentation opcodes** + +| Element | Command | Code | +|------------------|---------|-------| +| Trace | TR 9 | 12/9 | +| | TR 10 | 12/10 | +| | TR 11 | 12/11 | +| Marker | MK 9 | 13/9 | +| | MK 10 | 13/10 | +| | MK 11 | 13/11 | +| Partial erasure | PE 9 | 14/9 | +| | PE 10 | 14/10 | +| | PE 11 | 14/11 | +| Untrace | UT 9 | 15/9 | +| | UT 10 | 15/10 | +| | UT 11 | 15/11 | +| Set colour | SC R | 11/0 | +| | SC G | 11/1 | +| | SC Y | 11/2 | +| | SC B | 11/3 | +| | SC M | 11/4 | +| | SC C | 11/5 | +| | SC W | 11/6 | +| Line thickness | LT 1 | 10/0 | +| | LT 2 | 10/1 | +| | LT 3 | 10/2 | +| Complete erasure | CE | 0/12 | + +4.2 The quadrant number of the i-th vector, $\theta_i$ , is defined as (see Figure 3-1/T.150): + +$\theta_i = 1$ for $dx \geq 0, dy \geq 0$ + +$= 2$ for $dx < 0, dy \geq 0$ + +$= 3$ for $dx < 0, dy < 0$ + +$= 4$ for $dx \geq 0, dy < 0$ + +![Figure 3-1/T.150: Definition of quadrant number. A 2D Cartesian coordinate system with a horizontal axis labeled 'dx' and a vertical axis labeled 'dy'. The origin is labeled 'Relative origin' with an arrow pointing to it. The four quadrants are labeled with their respective quadrant numbers: theta=1 in the top-right, theta=2 in the top-left, theta=3 in the bottom-left, and theta=4 in the bottom-right. The axes are represented by solid lines with arrows at their ends.](484cfbdc05aee471306eeb11c0ee2543_img.jpg) + +Figure 3-1/T.150: Definition of quadrant number. A 2D Cartesian coordinate system with a horizontal axis labeled 'dx' and a vertical axis labeled 'dy'. The origin is labeled 'Relative origin' with an arrow pointing to it. The four quadrants are labeled with their respective quadrant numbers: theta=1 in the top-right, theta=2 in the top-left, theta=3 in the bottom-left, and theta=4 in the bottom-right. The axes are represented by solid lines with arrows at their ends. + +T0803840-89 + +FIGURE 3-1/T.150 + +**Definition of quadrant number** + +4.3 *Zone division and zone designation number* + +The space of vectors without signs is divided into square zones. The zones are numbered counterclockwise, as shown in Figure 3-2/T.150. + +The zone width is taken as the power of two. Thus the width of the k-th zone is defined as: + +$$W(k) = 2 \quad \text{for } k = 1$$ + +$$= 2 \times 2^{(k-2)/3} \quad \text{for } k > 1$$ + +4.4 The k-th zone $Z_k$ is defined as: + +- 1) for $k = 1$ + $Z_k = (|dx|, |dy|); 0 \leq |dx| \leq W(k) - 1, 0 \leq |dy| \leq W(k) - 1$ +- 2) for $k > 1$ + - a) for $k = 0 \pmod{3}$ + $Z_k = (|dx|, |dy|); W(k) \leq |dx| \leq 2W(k) - 1, W(k) \leq |dy| \leq 2W(k) - 1$ + - b) for $k = 1 \pmod{3}$ + $Z_k = (|dx|, |dy|); 0 \leq |dx| \leq W(k) - 1, W(k) \leq |dy| \leq 2W(k) - 1$ + - c) for $k = 2 \pmod{3}$ + $Z_k = (|dx|, |dy|); W(k) \leq |dx| \leq 2W(k) - 1, 0 \leq |dy| \leq W(k) - 1$ + +![A grid diagram illustrating zone division and zone designation numbers. The horizontal axis is labeled |dx| and the vertical axis is labeled |dy|, both ranging from 0 to 10. The grid is divided into zones by thick lines. Zone 1 is the bottom-left 3x3 area (|dx|, |dy| from 0 to 2). Zone 2 is the area to the right of zone 1 (|dx| from 3 to 5, |dy| from 0 to 2). Zone 3 is the area above zone 1 (|dx| from 0 to 2, |dy| from 3 to 5). Zone 4 is the area to the right of zone 3 (|dx| from 3 to 5, |dy| from 3 to 5). Zone 5 is the area below zone 4 (|dx| from 6 to 7, |dy| from 0 to 2). Zone 6 is the area to the right of zone 5 (|dx| from 8 to 9, |dy| from 0 to 2). Zone 7 is the area above zone 5 (|dx| from 0 to 2, |dy| from 6 to 7). Zone 8 is the area to the right of zone 7 (|dx| from 3 to 5, |dy| from 6 to 7). Zone 9 is the area above zone 7 (|dx| from 0 to 2, |dy| from 8 to 9). Zone 10 is the area to the right of zone 9 (|dx| from 3 to 5, |dy| from 8 to 9). The zones are arranged in a pattern that repeats every 3 units in both |dx| and |dy| directions, with the origin (0,0) being the lower-left corner of zone 1.](20727e57890be6da5692a02d13c0a8ec_img.jpg) + +A grid diagram illustrating zone division and zone designation numbers. The horizontal axis is labeled |dx| and the vertical axis is labeled |dy|, both ranging from 0 to 10. The grid is divided into zones by thick lines. Zone 1 is the bottom-left 3x3 area (|dx|, |dy| from 0 to 2). Zone 2 is the area to the right of zone 1 (|dx| from 3 to 5, |dy| from 0 to 2). Zone 3 is the area above zone 1 (|dx| from 0 to 2, |dy| from 3 to 5). Zone 4 is the area to the right of zone 3 (|dx| from 3 to 5, |dy| from 3 to 5). Zone 5 is the area below zone 4 (|dx| from 6 to 7, |dy| from 0 to 2). Zone 6 is the area to the right of zone 5 (|dx| from 8 to 9, |dy| from 0 to 2). Zone 7 is the area above zone 5 (|dx| from 0 to 2, |dy| from 6 to 7). Zone 8 is the area to the right of zone 7 (|dx| from 3 to 5, |dy| from 6 to 7). Zone 9 is the area above zone 7 (|dx| from 0 to 2, |dy| from 8 to 9). Zone 10 is the area to the right of zone 9 (|dx| from 3 to 5, |dy| from 8 to 9). The zones are arranged in a pattern that repeats every 3 units in both |dx| and |dy| directions, with the origin (0,0) being the lower-left corner of zone 1. + +FIGURE 3-2/T.150 + +**Zone division and zone designation number** + +4.5 The origin of the relative addresses in each zone is the lower left corner. The relative address in the k-th zone, $(A_x, A_y)$ , is defined as: + +- 1) for $k = 1$ + $A_x = dx, A_y = dy$ +- 2) for $k > 1$ + - a) for $k = 0 \pmod{3}$ + $A_x = |dx| - W(k), A_y = |dy| - W(k)$ + - b) for $k = 1 \pmod{3}$ + $A_x = |dx|, A_y = |dy| - W(k)$ + - c) for $k = 2 \pmod{3}$ + $A_x = |dx| - W(k), A_y = |dy|$ + +4.6 Quadrant number difference $d\theta_i$ is defined as: + +$$d\theta_i = \theta_i - \theta_{i-1}$$ + +where $\theta_0 = 1$ for simplicity. + +4.7 Zone number difference $dk_i$ is defined as: + +$$dk_i = k_i - k_{i-1}$$ + +where $k_i$ is the zone number obtained by the $i$ -th vector, and $k_0 = 1$ for simplicity. + +### 5 Specification of the coding + +5.1 The first pen-down point is represented by the binary expression of the absolute coordinate pair $(x_0, y_0)$ , as follows: + +![Diagram showing the binary representation of the absolute coordinate pair (x0, y0). The x0 coordinate is represented by a 9-bit field with MSB on the left and LSB on the right. The y0 coordinate is represented by a 9-bit field with MSB on the left and LSB on the right. The total length is 2 x 9 bits.](5b6e139e89c6ce90107ea7d7d77620a0_img.jpg) + +$x_0$ + $y_0$ + +MSB +LSB + +MSB +LSB + +2 × 9 bits + +Diagram showing the binary representation of the absolute coordinate pair (x0, y0). The x0 coordinate is represented by a 9-bit field with MSB on the left and LSB on the right. The y0 coordinate is represented by a 9-bit field with MSB on the left and LSB on the right. The total length is 2 x 9 bits. + +MSB    Most significant bit + LSP    Least significant bit + +5.2 All successive pen-down points are represented by zone codes (ZC) and relative addresses $(A_x, A_y)$ . + +5.3 The zero vector $(0, 0)$ is not coded and transmitted. It is also possible the zone vector $(|X_i - X_{i-1}| \leq 1, |Y_i - Y_{i-1}| \leq 1)$ will be rejected before being coded. + +5.4 The zone code is defined in Table 3-3/T.150. The table specifies a zone code number 1 to 30 and a bit combination for 30 combinations of $d\theta$ and $dk$ . + +5.5 The relative addresses $(A_x, A_y)$ are represented by: + +5.6 The bit length $L$ is decided by: + +$$L = 2 \log_2 W(k).$$ + +5.7 For the combination of $d\theta$ and $dk$ , not defined in Table 3-3/T.150, the absolute addresses $(x_i, y_i)$ follow EFZ, instead of ZC. + +5.8 A stroke is terminated by the pen lift indicator (PLI) as soon as the pen is lifted. + +5.9 The full data format of a stroke is illustrated in Figure 3-3/T.150. + +### 6 A coding example + +The trace of handwritten information is shown in Figure 3-4/T.150, where $P_i$ is the sampled point. An example of how to encode the coordinate data is shown in Table 3-4/T.150. The zone coded bit stream is shown in Figure 3-5/T.150. + +### **7 Data structure** + +7.1 The zone coding opcodes and operands and the opcodes representing control commands are transmitted in the form of data packets. + +7.2 Each packet consists of a header octet ISP (information separator), followed by an integral number of octets, and terminated by an ISP octet. + +7.3 A packet may contain an undetermined number of opcodes. Boundaries of opcodes coincide with the boundaries of octets. + +7.4 Data of variable length (the operand) is preceded by an opcode. After each operand the packet is terminated by an ISP octet at the earliest regular octet boundary. + +7.5 If the end of the operand does not coincide with an octet boundary, the remaining bit positions until the octet boundary shall be filled with bits of the value ZERO. + +At the receiving end, these zeros are ignored. + +TABLE 3-3/T.150 + +Zone code table + +| Zone code No. | dθ | dk | Length of
the code (bit) | Code
(the left bit is LSB) | +|---------------|----|----|-----------------------------|-------------------------------| +| 1 | 0 | 0 | 2 | 01 | +| 2 | 3 | 0 | 4 | 00 01 | +| 3 | 1 | 0 | 4 | 11 11 | +| 4 | 0 | 3 | 4 | 00 10 | +| 5 | 0 | 1 | 4 | 10 11 | +| 6 | 0 | -3 | 4 | 11 10 | +| 7 | 3 | 3 | 5 | 10 01 1 | +| 8 | 0 | -1 | 5 | 00 11 1 | +| 9 | 3 | -1 | 6 | 10 01 01 | +| 10 | 3 | -3 | 6 | 10 00 01 | +| 11 | 2 | 0 | 6 | 00 11 01 | +| 12 | 1 | 3 | 6 | 10 10 01 | +| 13 | 1 | 1 | 6 | 10 00 11 | +| 14 | 1 | -3 | 6 | 10 10 11 | +| 15 | 0 | 4 | 6 | 10 00 10 | +| 16 | 0 | 2 | 6 | 00 00 11 | +| 17 | 0 | -2 | 6 | 00 00 01 | +| 18 | 3 | 2 | 7 | 10 00 00 1 | +| 19 | 3 | 1 | 7 | 10 01 00 1 | +| 20 | 2 | 3 | 7 | 10 10 10 0 | +| 21 | 1 | 2 | 7 | 10 10 00 1 | +| 22 | 1 | -1 | 7 | 00 11 00 1 | +| 23 | 1 | -2 | 7 | 10 01 00 0 | +| 24 | 0 | 6 | 7 | 00 00 00 1 | +| 25 | 0 | -4 | 7 | 00 11 00 0 | +| 26 | 0 | -6 | 7 | 10 10 00 0 | +| 27 | 3 | 6 | 8 | 10 10 10 10 | +| 28 | 2 | 1 | 8 | 10 00 00 01 | +| 29 | 2 | -1 | 8 | 10 10 10 11 | +| 30 | 2 | -3 | 8 | 00 00 00 01 | +| PLI | | | 3 | 11 0 | +| EFZ | | | 6 | 00 00 10 | +| NULL | | | 8 | 00 00 00 00 | + +PLI    Pen lift indicator +EFZ    Escape from zone code, + +![Diagram showing the bit order for coordinates Ax and Ay. Ax is represented by a box with 'A_x' inside, with 'MSB' below the left side and 'LSB' below the right side. Ay is represented by a box with 'A_y' inside, with 'MSB' below the left side and 'LSB' below the right side.](9f9386d5b3d6cbeb1ed104a799320ebf_img.jpg) + +MSB                      LSB      MSB                      LSB + +Diagram showing the bit order for coordinates Ax and Ay. Ax is represented by a box with 'A\_x' inside, with 'MSB' below the left side and 'LSB' below the right side. Ay is represented by a box with 'A\_y' inside, with 'MSB' below the left side and 'LSB' below the right side. + +![](08dce7ad4c512fdf0c0cde60415fade6_img.jpg) + +| | | | +|-----|-------|-------| +| EFZ | $x_i$ | $y_i$ | +| MSB | MSB | | + +![](c76da2d73c064464051d1583fd80bb6b_img.jpg) + +| | | | | | | | | +|-------|-------|-------|------|-------|------|-----|-----| +| $x_0$ | $y_0$ | ZC(1) | A(1) | ZC(2) | A(2) | ... | PLI | +|-------|-------|-------|------|-------|------|-----|-----| + +$x_0, y_0$ Starting address + +ZC(i) Zone code of the i-th vector + +A(i) Relative address of the ith vector + +PLI Pen lift indicator + +FIGURE 3-3/T.150 + +Stroke data format + +![A graph showing a handwritten information trace on a coordinate system. The x-axis is labeled 'x' and ranges from 1 to 10. The y-axis is labeled 'y' and ranges from 1 to 8. A series of points P0 through P6 are connected by lines. P0 is at (1, 3) and is labeled '(start)'. P1 is at (1, 4). P2 is at (2, 5). P3 is at (5, 6). P4 is at (7, 6). P5 is at (8, 5). P6 is at (9, 5) and is labeled '(end point)'. Dashed lines connect P0 to P1, P0 to the x-axis at x=1, and P6 to the x-axis at x=9.](db2f2503931949e0258f7f10eba14eb5_img.jpg) + +T0803860-89 + +A graph showing a handwritten information trace on a coordinate system. The x-axis is labeled 'x' and ranges from 1 to 10. The y-axis is labeled 'y' and ranges from 1 to 8. A series of points P0 through P6 are connected by lines. P0 is at (1, 3) and is labeled '(start)'. P1 is at (1, 4). P2 is at (2, 5). P3 is at (5, 6). P4 is at (7, 6). P5 is at (8, 5). P6 is at (9, 5) and is labeled '(end point)'. Dashed lines connect P0 to P1, P0 to the x-axis at x=1, and P6 to the x-axis at x=9. + +FIGURE 3-4/T.150 + +Handwritten information trace + +TABLE 3-4/T.150 + +Coding example + +| i | x, y | dx, dy | $\theta$ | k | d $\theta$ | dk | ZC | A x , A y | W(k) | L/2 | ZC-code | +|---|------|--------|----------|-----|------------|----|----|---------------------------------|------|-----|---------| +| 0 | 1, 3 | | (1) | (1) | | | | | | | | +| 1 | 1, 4 | 0, 1 | 1 | 1 | 0 | 0 | 1 | 0, 1 | 2 | 1 | 01 | +| 2 | 2, 5 | 1, 1 | 1 | 1 | 0 | 0 | 1 | 1, 1 | 2 | 1 | 01 | +| 3 | 5, 6 | 3, 1 | 1 | 2 | 0 | 1 | 5 | 1, 1 | 2 | 1 | 1011 | +| 4 | 7, 6 | 2, 0 | 1 | 2 | 0 | 0 | 1 | 0, 0 | 2 | 1 | 01 | +| 5 | 8, 5 | 1, -1 | 4 | 1 | 3 | -1 | 9 | 1, 1 | 2 | 1 | 100101 | +| 6 | 9, 5 | 1, 0 | 1 | 1 | 1 | 0 | 3 | 1, 0 | 2 | 1 | 1111 | + +![Diagram showing the zone coded bit stream structure. It consists of several fields: P0, D1, D2, D3, D4, D5, D6, and PLI. Each field is represented by a horizontal line with a bracket above it. Below the line, the bits are listed, and then the corresponding labels are given. For example, P0 has two groups of three bits: 000 000 001 and 000 000 011, labeled x0 and y0 respectively. D1 has three bits: 01 0 1, labeled ZC Ax Ay. D2 has three bits: 01 1 1, labeled ZC Ax Ay. D3 has three bits: 1011 1 1, labeled ZC Ax Ay. D4 has three bits: 01 0 0, labeled ZC Ax Ay. D5 has three bits: 100101 1 1, labeled ZC Ax Ay. D6 has three bits: 1111 1 1, labeled ZC Ax Ay. PLI has three bits: 110.](05eb72d372e4bf78e3d6a64949d77bcc_img.jpg) + +P0 + +000 000 001    000 000 011 + +x0    y0 + +D1 + +01    0    1 + +ZC    Ax    Ay + +D2 + +01    1    1 + +ZC    Ax    Ay + +D3 + +1011    1    1 + +ZC    Ax    Ay + +D4 + +01    0    0 + +ZC    Ax    Ay + +D5 + +100101    1    1 + +ZC    Ax    Ay + +D6 + +1111    1    1 + +ZC    Ax    Ay + +PLI + +110 + +T0803870-89 + +Diagram showing the zone coded bit stream structure. It consists of several fields: P0, D1, D2, D3, D4, D5, D6, and PLI. Each field is represented by a horizontal line with a bracket above it. Below the line, the bits are listed, and then the corresponding labels are given. For example, P0 has two groups of three bits: 000 000 001 and 000 000 011, labeled x0 and y0 respectively. D1 has three bits: 01 0 1, labeled ZC Ax Ay. D2 has three bits: 01 1 1, labeled ZC Ax Ay. D3 has three bits: 1011 1 1, labeled ZC Ax Ay. D4 has three bits: 01 0 0, labeled ZC Ax Ay. D5 has three bits: 100101 1 1, labeled ZC Ax Ay. D6 has three bits: 1111 1 1, labeled ZC Ax Ay. PLI has three bits: 110. + +FIGURE 3-5/T.150 +Zone coded bit stream + +7.6 Successive packets may be sent contiguously, separated by a single ISP octet. See Figure 3-6/T.150. + +![Diagram of packet organization showing a sequence of transmission data packets (T1, T2, T3) separated by ISP octets. A single octet is indicated above the first ISP octet.](85e2327652d513a7fee8fdbf97ad06f1_img.jpg) + +The diagram shows a horizontal sequence of octets. It starts with an 'ISP' octet, followed by a transmission data packet 'T1' (8 octets), then another 'ISP' octet, followed by transmission data packet 'T2' (8 octets), then a third 'ISP' octet, followed by transmission data packet 'T3' (3 octets), and finally a fourth 'ISP' octet. A bracket above the first 'ISP' octet is labeled 'one octet'. Below the sequence, a label reads 'T1, T2, T3 Transmission data packet (variable length data)'. The reference 'T0803880-89' is at the bottom right. + +Diagram of packet organization showing a sequence of transmission data packets (T1, T2, T3) separated by ISP octets. A single octet is indicated above the first ISP octet. + +FIGURE 3-6/T.150 +Packet organization + +7.7 If one of the octets containing variable length data accidentally imitates an ISP octet, the transmitter inserts an extra ISP octet, so that the imitation is duplicated. See Figure 3-7/T.150. + +If the imitation results from a combination of bits in two adjacent octets, no action is taken. + +![Diagram illustrating ISP octet stuffing. The original signal has an ISP octet followed by octets a through n. An ISP imitation occurs in octet f. The stuffed signal duplicates the ISP octet, resulting in two ISP octets followed by octets a through n.](0ee9d674085524d589646a6c3fb21ec3_img.jpg) + +The diagram shows two rows of octets. The top row, labeled 'Original signal', contains octets: ISP, a, b, c, d, e, f, g, h, i, j, k, l, m, n. An arrow points to octet 'f' with the label 'ISP imitation'. The bottom row, labeled 'Stuffed signal', contains octets: (empty), ISP, a, b, c, d, e, (empty), f, g, h, i, j, k, l, m, n. An arrow points to the empty octet after 'e' with the label 'Extra ISP'. The reference 'T0803890-89' is at the bottom right. + +Diagram illustrating ISP octet stuffing. The original signal has an ISP octet followed by octets a through n. An ISP imitation occurs in octet f. The stuffed signal duplicates the ISP octet, resulting in two ISP octets followed by octets a through n. + +FIGURE 3-7/T.150 +ISP octet stuffing + +7.8 The receiver ignores the second ISP octet from each pair of ISP octets. + +### 8 Temporary pen-stop + +8.1 During the writing process, the pen may stop at an arbitrary instant, remaining on the writing surface. As a consequence, the completion of the current operand is suspended. + +8.2 Generally, the instant of pen-stop does not coincide with a byte boundary. In order to provide the receiving party with up-to-date information including the correct pen-stop position, the content of the incomplete byte should be transmitted prior to the MARK signal representing the writing pause. + +8.3 The above can be achieved by means of the insertion of 8 extra bits, the NULL bits, in the bitstream. Each NULL bit has the binary value Zero. + +8.4 The NULL bits are subdivided into two groups, one group preceding the MARK signal, the other group following the MARK signal. + +- 8.5 The number of NULL bits in the first group equals the number of open bit positions in the current byte. This number is referred to as N. +- 8.6 By the inclusion of N NULL bits the current byte is complete and can be transmitted. It is followed by the MARK signal. +- 8.7 As soon as the next writing activity occurs, the MARK signal is terminated. +- 8.8 The remaining 8-N NULL bits are to occupy the leading bit-positions of the first byte after the MARK signal. +- 8.9 The NULL bit mechanism is illustrated in Figure 3-8/T.150. + +![Diagram illustrating the NULL bit insertion mechanism. A horizontal bar represents a data stream divided into segments: ISP, PE, ZC operand, NULL N bits, MARK signal, NULL 8-N, ZC operand, PLI, ZERO's, and ISP. A 'Pen-stop' arrow points to the NULL N bits segment. Below the bar, arrows indicate byte boundaries at the start of each segment. The text 'Arrows indicate byte boundaries' is at the bottom left, and 'T0803900-89' is at the bottom right.](339be989b91d5b1e73e5ecdc8401ca75_img.jpg) + +Diagram illustrating the NULL bit insertion mechanism. A horizontal bar represents a data stream divided into segments: ISP, PE, ZC operand, NULL N bits, MARK signal, NULL 8-N, ZC operand, PLI, ZERO's, and ISP. A 'Pen-stop' arrow points to the NULL N bits segment. Below the bar, arrows indicate byte boundaries at the start of each segment. The text 'Arrows indicate byte boundaries' is at the bottom left, and 'T0803900-89' is at the bottom right. + +FIGURE 3-8/T.150 +NULL bit insertion mechanism + +### 9 Control commands + +- 9.1 This section defines control commands, affecting the functioning of the terminal at the presentation level. + +These commands are: + +- complete erasure, +- escape, +- information separator. + +#### 9.2 Complete erasure CE + +This command is defined already in Table 3-1/T.150. It is repeated here because of the buffer control aspect. + +The displayed image is erased completely, both at the sending side and the receiving side. Also the telewriting data in the transmission buffer at the sending side, and in the reception buffer at the receiving side is erased. + +#### 9.3 Escape ESC + +This is a code extension command. ESC is to be followed by an 8-bit operand, defining an alternative code table. ESC + operand is to be sent by an enhanced Telewriting terminal prior to each enhanced operation function. Details are to be defined in a section on enhanced terminal. + +#### 9.4 Information separator ISP + +ISP acts as a delimiter of command packets as defined in § 7. The terminal should check received data streams for pairs of ISP octets and, where required, should reject every second ISP octet. + +- 9.5 The coding of the above commands is defined in Table 3-5/T.150 (the notation x/y means column x, row y, in a $16 \times 16$ code table). + +TABLE 3-5/T.150 + +#### Coding of control commands + +| Function | Acronym | Coding | +|-----------------------|---------|--------| +| Complete erasure | CE | 0/12 | +| Escape | ESC | 1/11 | +| Information separator | ISP | 1/15 | + +### 10 Summary code table + +A summary of the coding for the opcodes is given in Figure 3-9/T.150. All elements included have been defined in the previous sections. + +| | | | | | | | | | | | | | | | | | | +|--------------|----|-----|-----|---|---|---|---|---|---|---|---|-----|-----|------|------|------|------| +| bbbb
4321 | b8 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | +| | b7 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | +| | b6 | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 1 | +| | b5 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | +| | | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | +| 0000 | 0 | | | | | | | | | | | LT1 | SCR | | | | | +| 0001 | 1 | | | | | | | | | | | LT2 | SCG | | | | | +| 0010 | 2 | | | | | | | | | | | LT3 | SCY | | | | | +| 0011 | 3 | | | | | | | | | | | | SCB | | | | | +| 0100 | 4 | | | | | | | | | | | | SCM | | | | | +| 0101 | 5 | HLO | | | | | | | | | | | SCC | | | | | +| 0110 | 6 | | | | | | | | | | | | SCW | | | | | +| 0111 | 7 | | SSO | | | | | | | | | | | | | | | +| 1000 | 8 | | | | | | | | | | | | | | | | | +| 1001 | 9 | | | | | | | | | | | | | TR9 | MK9 | PE9 | UT9 | +| 1010 | 10 | | | | | | | | | | | | | TR10 | MK10 | PE10 | UT10 | +| 1011 | 11 | | ESC | | | | | | | | | | | TR11 | MK11 | PE11 | UT11 | +| 1100 | 12 | CE | | | | | | | | | | | | | | | | +| 1101 | 13 | | | | | | | | | | | | | | | | | +| 1110 | 14 | | | | | | | | | | | | | | | | | +| 1111 | 15 | | ISP | | | | | | | | | | | | | | | + +T0803910-89 + +S8 0643A/272-12'87/ZWA +b1 LSB +b8 MSB + +FIGURE 3-9/T.150 +Summary code table + +### 11 Summary transmission data format + +The transmission data format is illustrated in Figure 3-10/T.150. + +![Diagram of the summary transmission data format showing the structure of the data stream.](02bb4edc0dbdf4f0749ffd3e0ea2805c_img.jpg) + +The diagram illustrates the summary transmission data format. It shows a sequence of fields: 'Previous data', 'Mark', 'ISP', 'Data', 'ISP', and 'Mark'. The 'Data' field is expanded to show its internal structure: 'ISP', 'ZC data', 'ISP', 'ZC data', 'ISP', and 'ISP'. The 'ZC data' field is further expanded to show its internal structure: 'Opcode', 'Operand', 'x0', 'y0', 'ZC1', 'A1', 'ZC2', 'A2', 'PLI', and 'Zeros'. + +Diagram of the summary transmission data format showing the structure of the data stream. + +T0803920-89 + +Mark Mark polarity + ISP Information separator octet + ZC Zone coding + x0, y0 Starting coordinate + A Relative address + PLI Pen lift indicator + Zeros Added zeros, to give the operand a length of an integral number of octets + +FIGURE 3-10/T.150 + +Summary transmission data format + +### 12 Zone coding basic terminal + +12.1 The basic terminal must be able to receive and correctly process the following presentation element commands: + TR 9, MK 9, PE 9, CE, ISP. + +12.2 The following presentation elements are optional: + +TR 10, TR 11 + MK 10, MK 11 + PE 10, PE 11 + UT 9, UT 10, UT 11. + +I.e. the transmitter may or may not be equipped with these commands. + +The receiver must be able to receive and correctly process these commands. + +12.3 The following control commands are optional: + +ESC, LT\*, SC\* + +I.e. the receiver will accept these commands but does not undertake any further action. + +## Part 4 – Differential chain coding + +### 1 General + +- 1.1 This part of the Recommendation defines details of the differential chain coding method. +- 1.2 For an application of differential chain coding together with telephony, the combined requirements from Parts 1, 2 and 4 apply. +- 1.3 Differential chain coding is derived from the Videotex geometric coding as defined in Recommendation T.101, Annex C (CEPT Videotex). +- 1.4 The telewriting functionalities are nearly a subset of the Videotex geometric functionalities, as defined in Recommendation T.101, Annex C. +- 1.5 Differential chain coding was developed for compression purposes. In this coding method, the statistical properties of handwriting are employed. +- 1.6 This coding method uses spatial sampling of curves, as distinct from sampling with a fixed frequency. The size of the sampling steps is determined by the size of the so-called coding ring. +- 1.7 The precision of this coding method is expressed in grid units, GU. In the default situation, one GU corresponds to the binary fraction $2^{-9}$ of the unit length. +- 1.8 Each stroke of handwriting is processed by the writing pad circuitry and converted into a coded form. +The coded representation of a stroke is called TRACE. +- 1.9 The coding of the presentation element trace, as well as the coding of the remaining presentation elements is defined in terms of 7 bit coding. +- 1.10 Conversion into 8 bit structured coding as required for transmission, is also specified in this Recommendation. +- 1.11 The word “byte” where used in this Recommendation, refers to a combination of 7 or 8 bits, whatever is appropriate in the given context. + +### 2 Presentation elements + +In differential chain coding, the following presentation elements are distinguished: + +- trace +- marker +- closed area +- partial erasure +- background +- complete erasure. + +The attributes are: + +- colour +- trace thickness +- trace texture. + +These presentation elements together with the attributes are described in Table 4-1/T.150. + +TABLE 4-1/T.150 + +#### **Differential chain coding presentation elements** + +| Element | Description | +|------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Trace | The trace is coded as a trace opcode plus a set of co-ordinate information defining a sequence of line segments. Trace corresponds with polyline in videotex. | +| Marker | The marker is coded as a marker opcode plus a single co-ordinate pair defining the position of the marker's center point. | +| Closed area | The closed area is coded by an opcode plus a set of co-ordinate information defining a closed perimeter. The closed area corresponds with fill area in videotex. | +| Partial erasure | Partial erasure is obtained by means of the closed area concept. By giving the closed area the same attributes as the background, erasure is achieved for the area enclosed in the perimeter. | +| Background | At initialization and after complete erasure, the background shows default appearance. Modification of the background is obtained by means of the closed area concept. The closed area is chosen to have the size of the image area. The area attributes are set to the desired background appearance. | +| Complete erasure | Complete erasure is obtained by means of the clear screen concept. The whole image area will be set to the default background appearance. | +| Colour | Colour is an attribute, applicable to trace and closed are (including background). The effect of a colour command remains valid until the next colour command. | +| Trace thickness | Trace thickness is an attribute. It is determined by means of a scale factor. The effect of a trace thickness command remains valid for all subsequent traces, until the next trace thickness command. | +| Trace texture | Trace texture is an attribute. It is determined by means of a parameter allowing a choice among defined textures. The effect of a trace texture command remains valid for all subsequent traces, until the next trace texture command. | +| Marker type | Marker type is an attribute. It is determined by means of a parameter allowing a choice among defined textures. The default value of marker type is 1. If the specified value is outside the range 0 ... 4, the marker is not displayed. | + +### **3 Description of the coding** + +- 3.1 The coded representation of a presentation element is called PRIMITIVE. +- 3.2 A primitive is composed of one opcode and a number of operands as required. +- 3.3 Certain opcodes are coded as a single byte, other opcodes are coded as combinations of two bytes. +- 3.4 The operand part of a primitive may utilize either basic format encoding or pointlist encoding. +- 3.5 In basic format encoding the operand part of the primitive contains one or more operands, each consisting of one or more bytes. + +- 3.6 In the pointlist encoding the operand part of the primitive contains coordinate information regarding an individual point or regarding a sequence of related points. +- 3.7 The position of an individual point, as well as the position of each first point of a sequence, is coded in absolute coordinates, i.e. the x- and y-coordinate with respect to the origin of the coding space. +- 3.8 For the coding of the remaining points of a sequence, a choice is to be made among two possibilities, namely displacement mode and incremental mode. +- 3.9 In the displacement mode, each point (after the first) is coded by means of two size value parameters. The first size value gives the x-component of the point's displacement from the preceding point in the sequence, the second size value gives the y-component of the displacement. +- 3.10 In the incremental mode, a mechanism is used in which a single value, derived from a table, determines the position of a point with respect to the preceding point. This mechanism is suitable for coding a sequence of points containing a high amount of position information, such as a trace. +- 3.11 The mechanism, introduced in § 3.10, is based on the use of a coding ring. At the beginning of trace, the starting point determines the centre point of the first ring. The intersection of trace and ring is identified and determines the centre point of the second ring. +- 3.12 Each new intersection determines the centre point for the next ring. Thus, the trace is represented by the starting point plus the series of intersection points. The end of a trace is indicated by means of the end of block-code. +- 3.13 The method for identifying the various points on a ring utilizes small numbers for points with a high probability of being intersected and larger numbers for points with lower probability. +- 3.14 The numbering system for the reference points on the ring is defined in §§ 4.6 and 4.7. + +### 4 Incremental mode mechanism + +- 4.1 The coding data in the incremental mode does not reflect coordinate size values, but represents a sequence of points identified by means of successive coding rings. Each ring identifies one point. +- 4.2 A ring is a set of reference points, positioned on the perimeter of a square. The position of the square is identified through the position of its centre point. The sides of the square are parallel to the x- and y-axes. +- 4.3 The characteristics of the ring are determined by its radius R, its angular resolution factor p and its direction D. +The size of R is expressed in GU. +- 4.4 The number of reference points on a ring is N. The value of N is determined by: +- $$N = \frac{8R}{2^p}, \text{ with } p = 0, 1, 2, 3.$$ +- It follows that the maximum number of reference points is $N = 8R$ . +- 4.5 N must be even. If N is odd, the encoded operand (the point list) must be discarded. If N is even for the first part of the operand, but N is odd for the remaining part, the remaining part (with N being odd) is discarded. +- 4.6 To the reference points on the ring, point numbers are assigned as follows. The numbering starts with 0. The point with number 0 is called the direction point. +- 4.7 The default position for the direction point is shown in Figure 4-1/T.150. Adjacent points are numbered 1 ... N/2-1 in anticlockwise direction, and -1 ... -N/2 in clockwise direction. Figure 4-1/T.150 shows two rings with the numbered reference points. +- 4.8 In the figure the left ring is characterized by $R = 3$ and $p = 0$ ; the right ring by $R = 3$ and $p = 1$ . + +![Figure 4-1/T.150: Two ring examples. The left plot shows a square grid with a central point labeled 'centre'. The x-axis ranges from -9 to 3 and the y-axis from -9 to 9. The right plot shows a smaller square grid with a central point labeled 'centre'. The x-axis ranges from -4 to 1 and the y-axis from -5 to 1. Both plots have parameters R=3 and p=0 for the left, and R=3 and p=1 for the right.](103781b498cc6846ffc11a041e14dc3e_img.jpg) + +Left plot parameters: $R = 3$ , $p = 0$ + +Right plot parameters: $R = 3$ , $p = 1$ + +Right plot identifier: T0804070-89 + +Figure 4-1/T.150: Two ring examples. The left plot shows a square grid with a central point labeled 'centre'. The x-axis ranges from -9 to 3 and the y-axis from -9 to 9. The right plot shows a smaller square grid with a central point labeled 'centre'. The x-axis ranges from -4 to 1 and the y-axis from -5 to 1. Both plots have parameters R=3 and p=0 for the left, and R=3 and p=1 for the right. + +**FIGURE 4-1/T.150** +**Two ring examples** + +4.9 The position of the reference points on each ring is fixed. However, the allocation of the point numbers is adapted to the trace direction as follows. + +4.10 For the first ring of a sequence (at the starting point), the direction point is at default position, as shown in Figure 4-1/T.150. + +4.11 As soon as the growing trace intersects the first ring, the nearest reference point is determined. This point constitutes the centre point for the next ring. + +4.12 The direction point on the second ring is located at that position where the next intersection would take place if the trace continued as a straight line. + +4.13 As the trace grows, the nearest reference point at each intersection is determined. The respective point numbers of these points are converted into variable length code words according to the Huffman code table, defined in Table 4-2/T.150. + +4.14 The radius can have a value of $R_0$ , $2R_0$ , $4R_0$ or $8R_0$ , where $R_0$ is the basic radius. + +The angular resolution factor $p$ can have a value of 0, 1, 2 or 3. + +To modify these parameters the code table contains the codes C1 ... C6. For their use, see further on. + +The basic radius $R_0$ can be specified by the primitive "set domain ring". The default basic radius follows from: +default basic radius = $2 \cdot \max(0, -8\text{-granularity code})$ . + +4.15 The length of the code table is fixed. The point numbering ranges from $-20$ to $+19$ . For the encoding in cases of rings with a higher number of reference points, two escape codes are defined: IM-ESC 1 and IM-ESC 2. For their use, see § 5. + +4.16 At the end of the trace no further intersections occur. The variable length coded string is terminated by end of block. + +TABLE 4-2/T.150 + +#### **Huffman code table for differential chain coding** + +| Code No | Length | Code-word | Point number | +|---------|--------|------------|--------------| +| 1 | 2 | 00 | 0 | +| 2 | 2 | 10 | 1 | +| 3 | 2 | 01 | -1 | +| 4 | 4 | 1100 | 2 | +| 5 | 4 | 1101 | -2 | +| 6 | 6 | 111000 | 3 | +| 7 | 6 | 111001 | -3 | +| 8 | 6 | 111010 | 4 | +| 9 | 6 | 111011 | -4 | +| 10 | 8 | 11110000 | 5 | +| 11 | 8 | 11110001 | -5 | +| 12 | 8 | 11110010 | 6 | +| 13 | 8 | 11110011 | -6 | +| 14 | 8 | 11110100 | 7 | +| 15 | 8 | 11110101 | -7 | +| 16 | 8 | 11110110 | 8 | +| 17 | 8 | 11110111 | -8 | +| 18 | 10 | 1111100000 | 9 | +| 19 | 10 | 1111100001 | -9 | +| 20 | 10 | 1111100010 | 10 | +| 21 | 10 | 1111100011 | -10 | +| 22 | 10 | 1111100100 | 11 | +| 23 | 10 | 1111100101 | -11 | +| 24 | 10 | 1111100110 | 12 | +| 25 | 10 | 1111100111 | -12 | +| 26 | 10 | 1111101000 | 13 | +| 27 | 10 | 1111101001 | -13 | +| 28 | 10 | 1111101010 | 14 | +| 29 | 10 | 1111101011 | -14 | +| 30 | 10 | 1111101100 | 15 | +| 31 | 10 | 1111101101 | -15 | +| 32 | 10 | 1111101110 | 16 | +| 33 | 10 | 1111101111 | -16 | +| 34 | 10 | 1111110000 | 17 | +| 35 | 10 | 1111110001 | -17 | +| 36 | 10 | 1111110010 | 18 | +| 37 | 10 | 1111110011 | -18 | +| 38 | 10 | 1111110100 | 19 | +| 39 | 10 | 1111110101 | -19 | +| 40 | 10 | 1111110110 | C1 | +| 41 | 10 | 1111110111 | -20 | +| 42 | 10 | 1111111000 | C2 | +| 43 | 10 | 1111111001 | C3 | +| 44 | 10 | 1111111010 | C4 | +| 45 | 10 | 1111111011 | C5 | +| 46 | 10 | 1111111100 | C6 | +| 47 | 10 | 1111111101 | IM-ESC 1 | +| 48 | 10 | 1111111110 | IM-ESC 2 | +| 49 | 10 | 1111111111 | End of block | + +### 5 Change of coding parameters + +5.1 The escape codes IM-ESC 1 and IM-ESC 2 enable the extension of the point numbering range on the ring. I.e. also points outside the range - 20 to + 19 can be addressed. By the code IM-ESC 1, the absolute value of the point number is increased by 20, the sign remains unchanged. + +By the code IM-ESC 2, the absolute value of the point number is increased by 40, the sign remains unchanged. + +5.2 The two escape codes can be used in combination with each other in any desired order. Some examples in Table 4-3/T.150 illustrate their use. The number between [ ] represents the point number. + +TABLE 4-3/T.150 + +Use of escape codes, examples + +| Description | | Intended point numbers | +|---------------------------|-------|------------------------| +| < IM-ESC 1 > | [1] | 21 | +| < IM-ESC 1 > | [-1] | -21 | +| < IM-ESC 2 > | [14] | 54 | +| < IM-ESC 2 > | [-12] | -52 | +| < IM-ESC 1 > < IM-ESC 2 > | [6] | 66 | +| < IM-ESC 2 > < IM-ESC 1 > | [-18] | -78 | + +5.3 The codes C1 up to C6 are used to change the parameters R and p that define the ring to be used. The use of these codes is defined in §§ 5.4 and 5.10. + +By the use of these codes the direction point is set at default position. + +5.4 The range in which the parameters should remain is as follows: + +R: R0, 2R0, 4R0, 8R0 (with R0 being the basic radius); + +p: 0, 1, 2, 3. + +5.5 Code C1 means: change R and p to the next higher value. E.g. if radius is R, the next higher is 2R; if $p = 0$ the next higher is 1. + +R cannot become greater than 8R0 and p cannot become greater than 3. E.g. if current radius is 8R0 or current $p = 3$ , the code C1 has no effect. + +5.6 Code C2 means: change R and p to the next lower value. The effect of C2 is the inverse of code C1. + +R cannot become smaller than R0 and p cannot become smaller than 0. E.g. if the current radius is R0 or the current $p = 0$ , the code C2 has no effect. + +5.7 Code C3 means: change R to the next higher value. The code C3 has no effect if the current radius = 8R0. + +5.8 Code C4 means: change p to the next higher value. The code C4 has no effect if the current $p = 3$ . + +5.9 Code C5 means: change R to the next lower value. The code C5 has no effect if the current radius = R0. + +5.10 Code C6 means: change p to the next lower value. The code C6 has no effect if the current $p = 0$ . + +### 6 Coding formats + +- 6.1 The coding is specified in terms of 7-bit coding. For use in the 8 bit environment as specified for transmission, bit No. b8 of each octet shall be set to ZERO. +- 6.2 For reference, an empty 7-bit code table is shown in Figure 4-2/T.150. + +| | | | | | | | | | +|--------------|----|---|---|---|---|---|---|---| +| b7 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | +| b6 | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 1 | +| b5 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | +| bbbb
4321 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | +| 0000 | 0 | | | | | | | | +| 0001 | 1 | | | | | | | | +| 0010 | 2 | | | | | | | | +| 0011 | 3 | | | | | | | | +| 0100 | 4 | | | | | | | | +| 0101 | 5 | | | | | | | | +| 0110 | 6 | | | | | | | | +| 0111 | 7 | | | | | | | | +| 1000 | 8 | | | | | | | | +| 1001 | 9 | | | | | | | | +| 1010 | 10 | | | | | | | | +| 1011 | 11 | | | | | | | | +| 1100 | 12 | | | | | | | | +| 1101 | 13 | | | | | | | | +| 1110 | 14 | | | | | | | | +| 1111 | 15 | | | | | | | | + +Reserved +for +control +functions + +Opcodes + +Operands + +T0803930-49 + +FIGURE 4-2/T.150 +General structure of the code table for differential chain coding + +- 6.3 The structure for opcode encoding is given in Figure 4-3/T.150. + +![](67d03c9e89620d73e3786c869e559752_img.jpg) + +b7b6b5b4b3b2b1 + +01 + +Opcode +flag + +Opcode + +Opcode length indicator + +FIGURE 4-3/T.150 +Opcode encoding structure + +For single-byte opcodes the opcode length indicator bit b5 is ZERO. Bits b4 to b1 represent the opcode, i.e. the opcodes are taken from column 2. For two-byte opcodes the opcode length indicator bit b5 of the first byte is ONE. Bits b4 to b1 of the first byte and bits b5 to b1 of the second byte represent the opcode, i.e. the first byte of the opcode is taken from column 3, the second byte is taken from column 2 or 3. + +6.4 The general format for operand encoding is given Figure 4-4/T.150. + +![Diagram of the general format for operand encoding. It shows a 7-bit register with bits b7 to b1. Bit b7 is labeled '1'. Bit b6 is labeled 'Operand flag'. Bits b5 to b1 are grouped together and labeled 'Operand'.](e22af684d8e56d4c61e61bb5ddac1087_img.jpg) + +The diagram shows a horizontal row of seven boxes representing bits b7, b6, b5, b4, b3, b2, and b1. The first box (b7) contains the number '1'. A bracket below the boxes from b6 to b1 is labeled 'Operand'. A line points from the label 'Operand flag' to bit b6. + +Diagram of the general format for operand encoding. It shows a 7-bit register with bits b7 to b1. Bit b7 is labeled '1'. Bit b6 is labeled 'Operand flag'. Bits b5 to b1 are grouped together and labeled 'Operand'. + +FIGURE 4-4/T.150 +Operand encoding structure + +The operand part of a primitive may contain one or more operands, each operand consisting of one or more bytes. + +6.5 The encoding of the operands may make use of the following DATA TYPES: + +- point P +- colour index CI +- integer number I +- real number R + +These data types are coded according to the basic format. + +6.6 The basic format for operand encoding is given in Figure 4-5/T.150. + +![Diagram of the basic format for operand encoding. It shows a 7-bit register with bits b7 to b1. Bit b7 is labeled '1'. Bit b6 is labeled 'Extension flag'. Bits b5 to b1 are grouped together and labeled 'Data bits'. Bit b7 is also labeled 'Operand flag'.](9dc9f41d7d76c1add4b190d348cb1533_img.jpg) + +The diagram shows a horizontal row of seven boxes representing bits b7, b6, b5, b4, b3, b2, and b1. The first box (b7) contains the number '1'. A bracket below the boxes from b5 to b1 is labeled 'Data bits'. A line points from the label 'Extension flag' to bit b6. A line points from the label 'Operand flag' to bit b7. + +Diagram of the basic format for operand encoding. It shows a 7-bit register with bits b7 to b1. Bit b7 is labeled '1'. Bit b6 is labeled 'Extension flag'. Bits b5 to b1 are grouped together and labeled 'Data bits'. Bit b7 is also labeled 'Operand flag'. + +FIGURE 4-5/T.150 +The basic format structure + +6.7 Each basic format operand is coded as a sequence of one or more bytes. + +Bit b6 of each byte is the extension flag. For single byte operands, the extension flag is ZERO. In multiple byte operands, the extension flag is ONE in all bytes, except the last byte, where it is ZERO. + +The most significant part of the operand is coded in the first byte. The least significant part of the operand is coded in the last byte. + +In data types P, I and R, bit 5 of the first byte represents the sign bit. Bit 5 = 0 corresponds to positive values. Following data bits represent a binary number. Bit 1 of the last byte is to be considered as the unit of this binary representation. + +Data type CI is coded in one single byte (b6 = 0). Bits 5 to 1 give the binary representation of colour indexes. + +The coding proposed here for data types P, CI, 1 and R although derived from Recommendation T.101, Annex C, is a simplified version of the encoding method for these data types, which is only valid after adequate initialization of the protocol description primitives. + +6.8 The position of a single point, as well as the position of the first point of a sequence is given by absolute coordinate values x0 and y0, expressed in grid units GU. The encoding structure is given in Figure 4-6/T.150. + +6.9 If the coordinate value fits in a single byte, the extension flag is set to ZERO. In that case the x-value is contained in one byte, the y-value is contained in the subsequent byte(s). + +6.10 If the coding of a coordinate value requires more than one byte, the complete position information is contained in two contiguous series of bytes. The first series contains the x-value, the second series contains the y-value. + +6.11 Each such series consists of contiguous bytes. The extension flag of all bytes in one series, except the last byte, is set to ONE. + +The extension flag of the last byte in the series is set to ZERO. + +### 7 Incremental mode coding format + +7.1 For incremental mode, the presentation elements trace and closed area are coded, according to the following sequence: + +- first point's position; +- DCC introducer; +- incremental sequence. + +![Diagram of the Absolute co-ordinate encoding structure showing the First byte and Following bytes (if any).](f943b07ab747bfd85e302e5a31c20ba8_img.jpg) + +The diagram illustrates the encoding structure for absolute coordinates. It consists of two parts: the 'First byte' and 'Following bytes (if any)'. + +**First byte:** A 7-bit byte structure with bits labeled b7 to b1. Bit b7 is set to 1. Bits b6, b5, b4, b3, b2, and b1 are grouped together and labeled as the 'Binary representation of co-ordinate'. Bit b6 is specifically labeled as the 'Sign'. Bit b5 is labeled as the 'Extension flag'. + +**Following bytes (if any):** A 7-bit byte structure with bits labeled b7 to b1. Bit b7 is set to 1. Bits b6, b5, b4, b3, b2, and b1 are grouped together and labeled as the 'Binary representation of co-ordinate'. + +Diagram of the Absolute co-ordinate encoding structure showing the First byte and Following bytes (if any). + +FIGURE 4-6/T.150 + +**Absolute co-ordinate encoding structure** + +7.2 The position of the first point is coded as defined in §§ 6.8 to 6.11. + +7.3 DCC is the abbreviation of differential chain code. The DCC introducer is required in order to preserve compatibility with Recommendation T.101. + +7.4 The DCC introducer consists of two bytes, see Figure 4-7/T.150. + +![](ae0a735d106290c594b0bafb1f5e72e7_img.jpg) + +| | b7 | b6 | b5 | b4 | b3 | b2 | b1 | +|-------------|----|----|----|----|----|----|----| +| First byte | 1 | 0 | 1 | 0 | 0 | 0 | 0 | +| Second byte | 1 | 0 | 0 | 0 | 0 | 0 | 1 | + +FIGURE 4-7/T.150 +DCC introducer encoding + +7.5 The format for encoding of the incremental sequence is given in Figure 4-8/T.150. + +![](0f1767577a073167eb9628d72034e083_img.jpg) + +| b7 | b6 | b5 | b4 | b3 | b2 | b1 | +|----|----|----|----|----|----|----| +| 1 | | | | | | | + +Data + +FIGURE 4-8/T.150 +Incremental sequence encoding + +7.6 The incremental sequence encoding uses variable length words. To accommodate these words in a sequence of bytes as given in Figure 4-8/T.150, the bit positions b6 to b1 of successive bytes are used as if they constitute a continuous bit channel. The first bit of the first variable length word is placed at b6, and so on. + +7.7 The end of the incremental sequence is identified by the end of block code. The remaining bit positions between end of block code and the next byte boundary have no meaning. They will be ignored. + +### 8 Displacement mode coding format + +8.1 For displacement mode, the presentation elements trace, closed area and marker are coded according to the following sequence: + +- first points position; +- following points. + +8.2 For points after the first point in a point list, each displacement is measured with respect to the preceding point of the point list. These displacements are coded as the first point of the list of points. + +### 9 Encoding of the primitives + +9.1 The opcodes are defined in Table 4-4/T.150. (The notation x/y means column x, row y, in a $8 \times 16$ code table.) + +9.2 The notational conventions used are defined in Table 4-5/T.150. + +In the further §§ 9.3 to 9.5 the encoding of each primitive is defined as well as the order of the parameters, along with their specific data type. + +9.3 The presentation elements trace, closed area and marker are encoded as follows: + +#### *Trace* + + (2) + +OR + + + +< DCC introducer: 5/0, 4/1 > + +##### *Closed area* + +< Closed area opcode: 2/1 > (3) + +OR + +< Closed area opcode: 2/1 > + +< Point: first point > < DCC introducer: 5/0, 4/1 > + +< Incremental sequence > + +#### *Marker* + +< Marker opcode: 3/2, 2/11, 5/2 > < point: position > + +OR + +< Marker opcode: 3/2, 2/11, 5/2 > < point: first point > (1) + +< DCC introducer: 5/0 4/1 > < Incremental sequence > + +##### *Clear* + +< Clear opcode: 3/2, 2/0, 4/0> + +TABLE 4-4/T.150 + +#### **Incremental Trace Coding opcodes** + +| Element | | Code | | | +|-----------------------|--------------------------------|--------|--------|--------| +| | | byte 1 | byte 2 | byte 3 | +| Presentation elements | Trace | 2/0 | – | – | +| | Closed area | 2/1 | – | – | +| | Marker | 3/2 | 2/11 | 5/2 | +| | Clear | 3/2 | 2/0 | 4/0 | +| | | | | | +| Attribute setting | Set trace thickness | 3/1 | 2/1 | | +| | Set trace texture | 3/1 | 2/2 | | +| | Set trace colour index | 3/1 | 2/0 | | +| | Set closed area interior style | 3/1 | 2/5 | | +| | Set closed area style index | 3/1 | 2/6 | | +| | Set closed area colour index | 3/1 | 2/4 | | +| | Set marker type | 3/1 | 2/12 | | +| | Set marker size | 3/1 | 2/13 | | +| | Set marker colour index | 3/1 | 2/11 | | +| Protocol descriptor | Set domain ring | 3/2 | 2/4 | | +| | Set co-ordinate precision | 3/2 | 2/9 | | + +TABLE 4-5/T.150 + +#### **Notational conventions** + +| Item | Meaning | +|-----------------|----------------------------------------| +| < symbols > | 1 occurrence | +| < symbols > (n) | n or more occurrences, with $n \geq 1$ | +| [comments] | Explanation of a production | +| < x : y > | Construction x with meaning y. | + +9.4 The attribute setting primitives are encoded as follows: + +##### *Trace thickness* + +< Set trace thickness opcode: 3/1, 2/1 > + + +##### *Trace texture* + + + = +   < integer: 0 >       [SOLID] +   < integer: 1 >       [DASHED] +   < integer: 2 >       [DOTTED] +   < integer: 3 >       [DASHED DOTTED] +   < all other values > [RESERVED] + +##### *Trace colour* + +< Set trace colour index opcode: 3/1, 2/0 > + = +   < index: 0 >       [black] +   < index: 1 >       [red] +   < index: 2 >       [green] +   < index: 3 >       [yellow] +   < index: 4 >       [blue] +   < index: 5 >       [magenta] +   < index: 6 >       [cyan] +   < index: 7 >       [white] + +##### *Closed area interior style* + +< Set closed area interior style opcode: 3/1, 2/5 > + < integer: fill area interior style > +   < integer: 0 >       [HOLLOW] +   < integer: 1 >       [SOLID] +   < integer: 2 >       [PATTERN] +   < integer: 3 >       [HATCH] +   < all other values > [RESERVED] + +##### *Closed area style index* + +< Set closed area style index opcode: 3/1, 2/6 > +< integer: closed area style index > = interior style HATCH +    < integer: 0 >           [vertical lines] +    < integer: 1 >           [horizontal lines] +    < integer: 2 >           [45 degrees lines] +    < integer: 3 >           [–45 degrees lines] +    < integer: 4 >           [closed lines, vertical and horizontal] +    < integer: 5 >           [crossed lines, 45 and – 45 degrees] +    < all other values >    [reserved] + +##### *Closed area colour index* + + + = +    < index: 0 >           [black] +    < index: 1 >           [red] +    < index: 2 >           [green] +    < index: 3 >           [yellow] +    < index: 4 >           [blue] +    < index: 5 >           [magenta] +    < index: 6 >           [cyan] +    < index: 7 >           [white] + +##### *Marker type* + +< Set marker type opcode: 3/1, 2/12 > +< integer:market type> = +    < integer: 0 >       [DOT] +    < integer: 1 >       [PLUS SIGN] +    < integer: 2 >       [ASTERISK] +    < integer: 3 >       [CIRCLE] +    < integer: 4 >       [DIAGONAL CROSS] +    < all other values > [RESERVED] + +##### *Marker size* + + + + +##### *Marker colour* + +< Set marker colour index opcode: 3/1, 2/11 > +< colour index: marker colour index > = +    < index: 0 >           [black] +    < index: 1 >           [red] +    < index: 2 >           [green] +    < index: 3 >           [yellow] +    < index: 4 >           [blue] +    < index: 5 >           [magenta] +    < index: 6 >           [cyan] +    < index: 7 >           [white] + +9.5 The protocol descriptor primitives are encoded as follows: + +##### *Set domain ring* + +< Set domain ring opcode: 3/2, 2/4 > +< integer:angular resolution factor > +< integer:basic radius of the ring > + +##### Set coordinate precision + +< Set coordinate precision opcode:3/2, 2/9 > + < integer: magnitude code > [4] + < integer: granularity code > [1 -9, -10, -11] + < integer: default exponent > [1 -9, -10, -11] + < integer: explicit exponent allowed > [1] + +9.6 *Remark 1* – The default value for “granularity code” and “default exponent” is –9. + +All the described coding is correct if the values for granularity and for default exponent are equal, and if the value of “explicit exponent allowed” is 1 (i.e. forbidden). + +*Remark 2* – The primitive set coordinate precision has no effect on reals (e.g. thickness scale factor). Reals are expressed (by default) in fractions of $2^{** -9}$ . + +### 10 Example of differential chain coding + +The trace of handwritten information is shown in Figure 4-9/T.150, where (P1, P2, P3) are the sampled points. These points are encoded in the incremental mode; the value of the ring radius is $R = 2$ and the value of the ring angular resolution factor is $p = 0$ , so the number of reference points on the ring is $N = 8 * R / (2^{** p}) = 16$ . On Figure 4-9/T.150, for each point, the corresponding ring with several reference points is shown. + +After coding, the new list of points is (Q1, Q2, Q3, Q4, Q5). The coordinate and reference points of $P_i$ and $Q_j$ are shown on Table 4-6/T.150. The difference chain code bitstream is shown on Figure 4-10/T.150. This bitstream with the appropriate DCC header could be a block. + +The initial trace can also be directly encoded in the displacement mode. Figure 4-11/T.150 shows how the list of points ( $P_1, P_2, P_3$ ) is encoded in this mode. + +TABLE 4-6/T.150 + +**T.150 coordinate values and reference point number** + +| | X | Y | | X | Y | reference point number | +|----|----|----|----|----|----|------------------------| +| P1 | 10 | 10 | Q1 | 10 | 10 | – | +| | | | Q2 | 12 | 12 | +2 | +| P2 | 13 | 14 | Q3 | 13 | 14 | +1 | +| | | | Q4 | 14 | 12 | –6 | +| P3 | 14 | 10 | Q5 | 14 | 10 | –1 | + +![A graph illustrating incremental mode encoding with points P1, Q1, P2, Q2, P3, Q3, Q4, and Q5. The graph shows a path defined by thick black lines. The background features a grid of dotted lines with numerical labels indicating encoding values.](a8523d225a4e279ab9e02f3c28cfa36a_img.jpg) + +The graph illustrates incremental mode encoding on a coordinate plane where the x-axis and y-axis both range from 10 to 15. A path is drawn with thick black lines connecting the following points: P1 (at approximately 10, 10), Q1 (overlapping P1), Q2 (at 12, 12), P2 (at 13, 14), Q3 (overlapping P2), Q4 (at 14, 12), P3 (at 14, 10), and Q5 (overlapping P3). Dotted lines form a grid and auxiliary paths, with small integer labels (e.g., -5 to 5) indicating relative offsets at various nodes. A reference label 'T0803940-89' is present in the bottom right corner of the plot area. + +A graph illustrating incremental mode encoding with points P1, Q1, P2, Q2, P3, Q3, Q4, and Q5. The graph shows a path defined by thick black lines. The background features a grid of dotted lines with numerical labels indicating encoding values. + +FIGURE 4-9/T.150 +Example of incremental mode encoding ( $R = 2$ , $p = 0$ ) + +![Diagram of DCC coded bitstream showing Trace opcode, Q1 (absolute coordinates), and DCC introducer.](89f8aefc01866631793087542316cef2_img.jpg) + +The diagram illustrates the structure of a DCC coded bitstream. It consists of several fields: + +- Trace opcode:** A 7-bit field with the value `00100000`. +- Q1 (absolute coordinates):** A 16-bit field divided into two 8-bit segments, each with the value `01001010`. Each segment is annotated with "value + 10". +- DCC introducer:** A 16-bit field divided into two 8-bit segments, with values `01010000` and `01000001`. +- Q2, Q3:** A 4-bit field with the value `01110010`, annotated with "+2" and "+1". +- Q4, Q5:** Two 8-bit fields with values `01111100` and `01110111`, annotated with "-6" and "-1" respectively. +- End of Bloc:** A 16-bit field with the value `01111111`, annotated with "EOB". +- EOB:** A final 8-bit field with the value `01110000`. + +Diagram of DCC coded bitstream showing Trace opcode, Q1 (absolute coordinates), and DCC introducer. + +Byte sequence: 2/0 4/10 4/10 5/0 4/1 7/2 7/12 7/7 7/15 7/0 + +FIGURE 4-10/T.150 + +DCC coded bitstream + +![Diagram of Displacement mode coded bitstream showing trace opcode and displacement values.](fe7304192caf64cda93b580c5e7e5c06_img.jpg) + +The diagram illustrates the structure of a Displacement mode coded bitstream. It consists of several fields: + +- trace opcode:** A 7-bit field with the value `01100000`. +- Displacement values:** A series of 8-bit fields with values `01001010`, `01001010`, `01000011`, `01000100`, `01000001`, and `01010100`. These are annotated with "value + 10", "value + 10", "value + 3", "value + 4", "value + 1", and "value - 4" respectively. + +Diagram of Displacement mode coded bitstream showing trace opcode and displacement values. + +$$P_1 = (10, 10)$$ + +$$P_2 - P_1 = (3, 4)$$ + +$$P_3 - P_2 = (1, -4)$$ + +Byte sequence: 2/0 4/10 4/10 4/3 4/4 4/1 5/4 + +FIGURE 4-11/T.150 + +Displacement mode coded bitstream \ No newline at end of file diff --git a/marked/T/T-REC-T.170-199802-I_PDF-E/raw.md b/marked/T/T-REC-T.170-199802-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..bf5fdd1a28aa0830041cf3e758079ba43153b68d --- /dev/null +++ b/marked/T/T-REC-T.170-199802-I_PDF-E/raw.md @@ -0,0 +1,249 @@ + + +![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# T.170 + +(02/98) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES + +--- + +# **Framework of the T.170-Series of Recommendations** + +ITU-T Recommendation T.170 + +(Previously CCITT Recommendation) + +--- + +# ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES** + +![A large empty rectangular box with a double border.](c803f6f6e2c49429d2951832bd0f208d_img.jpg) + +A large empty rectangular box with a double border, likely intended for a diagram or additional text related to the terminal services. + +A large empty rectangular box with a double border. + +*For further details, please refer to ITU-T List of Recommendations.* + +# **ITU-T RECOMMENDATION T.170** + +# **FRAMEWORK OF THE T.170-SERIES OF RECOMMENDATIONS** + +# **Summary** + +This Recommendation gives an overview of the T.170-Series of Recommendations and specifies the framework in which they can be used. + +## **Source** + +ITU-T Recommendation T.170 was prepared by ITU-T Study Group 16 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 6th of February 1998. + +# FOREWORD + +ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# INTELLECTUAL PROPERTY RIGHTS + +The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. + +© ITU 1998 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +# CONTENTS + +| | Page | +|-----------------------------------------------|-------------| +| 1 Scope..... | 1 | +| 2 Normative references ..... | 1 | +| 3 Definitions and abbreviations ..... | 1 | +| 3.1 Definitions ..... | 1 | +| 3.2 Abbreviations..... | 1 | +| 4 Overview..... | 2 | +| 4.1 Recommendation T.171 [1] ..... | 3 | +| 4.2 Recommendation T.172 [2] ..... | 3 | +| 4.3 Recommendation T.173 [3] ..... | 3 | +| 4.4 Recommendation T.174 [4] ..... | 3 | +| 4.5 Recommendation T.175 [5] ..... | 3 | +| 4.6 Recommendation T.176 [6] ..... | 3 | +| 5 Example of a multifunctional terminal ..... | 4 | + + + +## Recommendation T.170 + +# FRAMEWORK OF THE T.170-SERIES OF RECOMMENDATIONS + +(Geneva, 1998) + +# 1 Scope + +This Recommendation gives an overview of the T.170-Series of Recommendations and specifies the framework in which they can be used. + +# 2 Normative references + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. + +- [1] ITU-T Recommendation T.171 (1996), *Protocols for interactive audiovisual services: Coded representation of multimedia and hypermedia*. +- [2] ITU-T Recommendation T.172 (1998), *MHEG-5 support for base-level interactive applications*. +- [3] ITU-T Recommendation T.173 (1997), *MHEG-3 script interchange representation*. +- [4] ITU-T Recommendation T.174 (1996), *Application Programming Interface (API) for MHEG-1*. +- [5] ITU-T Recommendation T.175 (1998), *Application Programming Interface (API) for MHEG-5*. +- [6] ITU-T Recommendation T.176 (1998), *API for Digital Storage Media Command and Control (DSM-CC)*. + +# 3 Definitions and abbreviations + +## 3.1 Definitions + +This Recommendation defines the following term: + +**Application Programming Interface (API):** A boundary across which a software application uses facilities of programming languages to invoke software services. These facilities may include procedures or operations, shared data objects and resolution of identifiers. + +## 3.2 Abbreviations + +This Recommendation uses the following abbreviations: + +| | | +|-------|-----------------------------------| +| API | Application Programming Interface | +| ASN.1 | Abstract Syntax Notation One | +| ATM | Asynchronous Transfer Mode | + +| | | +|-----------|------------------------------------------------------------| +| DAVIC | Digital Audio Visual Council | +| DSM-CC | Digital Storage Media Command and Control | +| DSM-CC UN | DSM-CC User to Network | +| DSM-CC UU | DSM-CC User to User | +| IIOP | Internet Inter ORB Protocol | +| MHEG | Multimedia and Hypermedia information coding Experts Group | +| OMG | Object Management Group | +| ORB | Object Request Broker | +| STU | Set Top Unit | +| UNO | Universal Networked Objects | +| VM | Virtual Machine | + +# 4 Overview + +Figure 1 shows the framework of the T.170-Series of Recommendations: + +![Figure 1/T.170 – Framework diagram showing the relationship between various components of the T.170-Series of Recommendations.](d0abac95583b52a3b35f74a215567334_img.jpg) + +The diagram illustrates the framework of the T.170-Series of Recommendations. It features a large outer box labeled 'Framework Rec. T.170'. Inside this box, on the left, is a vertical stack of two boxes: 'MHEG-1 Rec. T.171' on top and 'MHEG-5 Rec. T.172' on the bottom. To the right of this stack is a larger box labeled 'Virtual Machine (VM) Rec. T.173'. Above the VM box is the label 'MHEG-1 API Rec. T.174', with an arrow pointing down to the top of the VM box. Below the VM box is the label 'MHEG-5 API Rec. T.175', with an arrow pointing up to the bottom of the VM box. To the right of the VM box is the label 'DSM-CC API Rec. T.176', with an arrow pointing left to the right side of the VM box. Below the entire 'Framework' box is a separate box labeled 'ISO/IEC DIS 13818-6 DSM-CC'. The identifier 'T1601910-97' is located in the bottom right corner of the diagram area. + +Figure 1/T.170 – Framework diagram showing the relationship between various components of the T.170-Series of Recommendations. + +**Figure 1/T.170 – Framework** + +The T.170-Series of Recommendations provides Standards defining the syntax of Multimedia and Hypermedia Applications as well as it provides a Virtual Machine and a set of APIs in order to be able to build a software architecture for multimedia applications that guarantees application portability. + +Applications can consist of either MHEG-1 or MHEG-5 objects. Both applications, MHEG-1 or MHEG-5 can use Virtual Machine (VM) code to enhance their functionality. However, application portability is guaranteed because the necessary interfaces for the terminal architecture are fully specified. + +Recommendation T.171 and Recommendation T.173 are generic standards covering the entire domain of possible multimedia applications. + +Recommendation T.172 and the DAVIC Virtual Machine can be viewed as specialisation of the above-mentioned Recommendations and are hence more suitable to be implemented in a concrete information retrieval scenario. + +A typical device based on the software architecture introduced in Figure 1 would be a Set Top Unit (STU) compliant with DAVIC 1.2 specifications. + +An Implementers Handbook for the T.170-Series is also available which gives guidance on how to implement Recommendation T.172 and DSM-CC. + +The following subclauses introduce the scope of the respective Recommendations. + +## **4.1 Recommendation T.171 [1]** + +Recommendation T.171 specifies the coded representation of multimedia application in the ASN.1 format. MHEG-1 is a generic standard applicable to a broad range of applications that can serve for future profiling activities. + +## **4.2 Recommendation T.172 [2]** + +Recommendation T.172 specifies semantics and final-form interchange syntax for MHEG-5 objects, based on concepts defined in Recommendation T.171. These objects are intended for use in the domain of simple client/server interactive multimedia applications, e.g. (Near) Video on Demand applications, navigation and browsing applications. + +## **4.3 Recommendation T.173 [3]** + +Recommendation T.173 specifies the MHEG Script Interchange Representation (MHEG-SIR) for the contents of script objects, i.e. the encoding of the script data component of the MHEG script class. The script functionality specified in Recommendation T.173 is based on VM-technology. + +## **4.4 Recommendation T.174 [4]** + +Recommendation T.174 specifies the API for the manipulation of multimedia and hypermedia information objects, i.e. the API that shall be provided by MHEG-1 engines for their control by applications. + +## **4.5 Recommendation T.175 [5]** + +Recommendation T.175 specifies the API for the manipulation of multimedia and hypermedia information objects, i.e. the API that shall be provided by MHEG-5 engines for their control by applications running on a DAVIC 1.1 compliant terminal. + +## **4.6 Recommendation T.176 [6]** + +Recommendation T.176 specifies the API of DSM-CC for the use in basic multimedia applications. Recommendation T.176 is applicable to DAVIC compliant systems. + +# 5 Example of a multifunctional terminal + +Figure 2 gives an example of the protocol stacks used in a multifunctional terminal supporting retrieval, conversational and conferencing services. + +![Figure 2/T.170 – Example of a multifunctional terminal. This diagram illustrates the protocol stacks for a multifunctional terminal. The top layer consists of several functional blocks: 'Call control' (containing Q.2931), 'System Control' (divided into 'H.245' and 'Object data coding T.170'), 'Audio Coding' (containing G.711/MPEG-1), 'Video coding' (containing H.262), and 'Data coding' (containing T.120 for conferencing, DVB-SI, Real-Time Graphics, etc.). Below these, a 'Multimedia multiplex and synchronisation' block (H.222.1/H.222.0) receives input from the coding blocks. The entire stack sits on a 'Network Adaptation AAL 5 (I.363.5)' layer, which in turn connects to an 'ATM' layer at the bottom.](cfda9df1319e04207eb28bcefd1dab7b_img.jpg) + +| | | | | | | +|------------------------------------|----------------|-----------------------------|--------------------------------------------------|-------------------------------------------------------------|-------------------------------------------------------------------------------------| +| Call control

Q.2931 | System Control | | Audio Coding

G.711/
MPEG-1 | Video coding

H.262 | Data coding
T.120
(conferencing case)
DVB-SI
Real-Time Graphics
etc. | +| | H.245 | Object data coding
T.170 | | | | +| | | DSM-CC
UN
UDP
IP | DSM-CC
UU
(OMG
UNO)
HOP
TCP
IP | Multimedia multiplex and synchronisation
H.222.1/H.222.0 | | +| | | | | | | +| Network Adaptation AAL 5 (I.363.5) | | | | | | +| ATM | | | | | | + +Figure 2/T.170 – Example of a multifunctional terminal. This diagram illustrates the protocol stacks for a multifunctional terminal. The top layer consists of several functional blocks: 'Call control' (containing Q.2931), 'System Control' (divided into 'H.245' and 'Object data coding T.170'), 'Audio Coding' (containing G.711/MPEG-1), 'Video coding' (containing H.262), and 'Data coding' (containing T.120 for conferencing, DVB-SI, Real-Time Graphics, etc.). Below these, a 'Multimedia multiplex and synchronisation' block (H.222.1/H.222.0) receives input from the coding blocks. The entire stack sits on a 'Network Adaptation AAL 5 (I.363.5)' layer, which in turn connects to an 'ATM' layer at the bottom. + +T1601920-97 + +**Figure 2/T.170 – Example of a multifunctional terminal** + +## ITU-T RECOMMENDATIONS SERIES + +| | | +|-----------------|--------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of the ITU-T | +| Series B | Means of expression: definitions, symbols, classification | +| Series C | General telecommunication statistics | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks and open system communications | +| Series Y | Global information infrastructure | +| Series Z | Programming languages | \ No newline at end of file diff --git a/marked/T/T-REC-T.173-199707-I_PDF-E/raw.md b/marked/T/T-REC-T.173-199707-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..78f9403b40dab1d22e9fa5eaad2cc797a14834df --- /dev/null +++ b/marked/T/T-REC-T.173-199707-I_PDF-E/raw.md @@ -0,0 +1,6651 @@ + + +![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# T.173 + +(07/97) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES + +--- + +# **MHEG-3 script interchange representation** + +ITU-T Recommendation T.173 + +(Previously CCITT Recommendation) + +--- + +## ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES** + +![A large empty rectangular box with a double border.](c803f6f6e2c49429d2951832bd0f208d_img.jpg) + +A large empty rectangular box with a double border. + +*For further details, please refer to ITU-T List of Recommendations.* + +## **ITU-T RECOMMENDATION T.173** + +# **MHEG-3 SCRIPT INTERCHANGE REPRESENTATION** + +## **Source** + +ITU-T Recommendation T.173 was prepared by ITU-T Study Group 16 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 10th of July 1997. + +## FOREWORD + +ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +## INTELLECTUAL PROPERTY RIGHTS + +The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, the ITU had/had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. + +© ITU 1998 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +# CONTENTS + +| | Page | +|------------------------------------------------|-------------| +| 1 Scope..... | 1 | +| 2 Normative references ..... | 1 | +| 3 Definitions ..... | 2 | +| 3.1 Definitions ..... | 2 | +| 3.2 Abbreviations..... | 6 | +| 4 General..... | 7 | +| 5.1 Information object conformance..... | 8 | +| 5.1.1 Profiles..... | 8 | +| 5.1.2 Encoding..... | 8 | +| 5.1.3 Syntax ..... | 8 | +| 5.1.4 Semantics..... | 8 | +| 5.2 Implementation conformance ..... | 8 | +| 5.2.1 Conformance requirements..... | 9 | +| 5.2.2 Conformance documentation..... | 9 | +| 5.3 Application conformance..... | 9 | +| 5.4 Test Methods..... | 10 | +| 6 Overview..... | 10 | +| 6.1 Description methodology..... | 10 | +| 6.2 Data processing operations ..... | 10 | +| 6.3 Access to external data and functions..... | 11 | +| 7 MHEG/MHEG-3 relationship..... | 12 | +| 7.1 MHEG entities ..... | 12 | +| 7.2 Functional entities..... | 12 | +| 7.3 MHEG-SIR script interpreter..... | 12 | +| 8 Elements of MHEG-SIR..... | 13 | +| 8.1 Data types..... | 13 | +| 8.1.1 Predefined types..... | 13 | +| 8.1.2 Declared constructed types ..... | 16 | +| 8.2 Data..... | 18 | +| 8.2.1 Immediate values ..... | 18 | +| 8.2.2 Constants ..... | 19 | +| 8.2.3 Variables..... | 19 | +| 8.3 Functions..... | 20 | +| 8.3.1 Routines..... | 20 | + +| | Page | +|---------------------------------------------------------------------|-------------| +| 8.3.2 Services..... | 21 | +| 8.3.3 Predefined functions ..... | 21 | +| 8.4 Messages ..... | 22 | +| 8.4.1 Package exceptions..... | 22 | +| 8.4.2 Predefined messages..... | 22 | +| 8.5 Instructions..... | 22 | +| 8.6 Identifiers ..... | 23 | +| 8.6.1 Type identifiers ..... | 23 | +| 8.6.2 Data identifiers ..... | 23 | +| 8.6.3 Function identifiers..... | 23 | +| 8.6.4 Message identifiers ..... | 24 | +| 9 The MHEG-SIR virtual machine ..... | 24 | +| 9.1 Structure of the MHEG-SIR virtual machine ..... | 24 | +| 9.2 Structures and notations..... | 25 | +| 9.2.1 Table ..... | 25 | +| 9.2.2 Stack ..... | 25 | +| 9.2.3 Parameter stack..... | 25 | +| 9.2.4 Queue..... | 25 | +| 9.2.5 Data representation ..... | 26 | +| 9.3 Memory areas..... | 27 | +| 9.3.1 Mh-script memory areas ..... | 27 | +| 9.3.2 Rt-script memory areas..... | 29 | +| 9.4 Script statuses ..... | 33 | +| 9.4.1 Mh-script statuses ..... | 33 | +| 9.4.2 Rt-script statuses..... | 33 | +| 9.5 Processing units ..... | 34 | +| 9.5.1 Message reception ..... | 34 | +| 9.5.2 Mh-script initialization ..... | 35 | +| 9.5.3 Rt-script initialization..... | 36 | +| 9.5.4 Rt-script execution unit ..... | 36 | +| 9.5.5 MHEG-SIR instruction execution unit..... | 36 | +| 10 Provisions for run-time environment access..... | 37 | +| 10.1 General model..... | 37 | +| 10.2 Declaration of IDL interfaces..... | 37 | +| 10.3 Invocation of external operations in an MHEG-SIR program ..... | 38 | +| 10.4 Handling of external exceptions in an MHEG-SIR program..... | 38 | +| 10.5 Invocation of external operations by an MHEG-3 engine ..... | 39 | + +| | Page | +|----------------------------------------------------------------|-------------| +| 10.6 Handling of external exceptions by an MHEG-3 engine ..... | 39 | +| 10.7 Platform mapping specifications..... | 39 | +| 11 Provisions for MHEG object manipulation ..... | 40 | +| 11.1 Invoking MHEG actions ..... | 40 | +| 11.1.1 Sending messages to other scripts ..... | 40 | +| 11.1.2 Exchange of information with MHEG objects ..... | 40 | +| 11.2 Receiving MHEG messages ..... | 40 | +| 11.2.1 MHEG-3 API run operations..... | 41 | +| 11.2.2 MHEG API exceptions ..... | 41 | +| 12 MHEG-SIR declarations ..... | 41 | +| 12.1 Type declaration..... | 42 | +| 12.1.1 Type identifier ..... | 42 | +| 12.1.2 Type description ..... | 42 | +| 12.2 Constant declaration ..... | 43 | +| 12.2.1 Data identifier ..... | 43 | +| 12.2.2 Type identifier ..... | 44 | +| 12.2.3 Constant value ..... | 44 | +| 12.3 Global variable declaration ..... | 44 | +| 12.3.1 Data identifier ..... | 44 | +| 12.3.2 Type identifier ..... | 45 | +| 12.3.3 Constant reference ..... | 45 | +| 12.4 Package declaration ..... | 45 | +| 12.4.1 Package identifier ..... | 45 | +| 12.4.2 Name..... | 46 | +| 12.4.3 Service description ..... | 46 | +| 12.4.4 Exception description ..... | 47 | +| 12.5 Handler declaration ..... | 48 | +| 12.5.1 Message identifier..... | 48 | +| 12.5.2 Function identifier ..... | 48 | +| 12.6 Routine declaration ..... | 48 | +| 12.6.1 Function identifier ..... | 49 | +| 12.6.2 Type identifier ..... | 49 | +| 12.6.3 Parameter description ..... | 49 | +| 12.6.4 Local variable declaration..... | 49 | +| 12.6.5 Program code..... | 50 | +| 13 MHEG-SIR instructions..... | 50 | + +| | Page | +|----------------------------------------------------|-------------| +| 13.1 Presentation methodology..... | 50 | +| 13.1.1 Error conditions ..... | 51 | +| 13.1.2 Formal specification ..... | 51 | +| 13.1.3 Data table notation..... | 51 | +| 13.1.4 Template instruction notation..... | 52 | +| 13.1.5 Primitives..... | 52 | +| 13.2 Classification of MHEG-SIR instructions ..... | 52 | +| 13.3 Description of instructions..... | 54 | +| 13.3.1 No operation ..... | 54 | +| 13.3.2 Yield ..... | 54 | +| 13.3.3 Return ..... | 55 | +| 13.3.4 Free ..... | 55 | +| 13.3.5 Not ..... | 56 | +| 13.3.6 Or ..... | 56 | +| 13.3.7 Exclusive or ..... | 57 | +| 13.3.8 And ..... | 57 | +| 13.3.9 Equal reference ..... | 57 | +| 13.3.10 Equal..... | 58 | +| 13.3.11 Less than ..... | 58 | +| 13.3.12 Greater than ..... | 59 | +| 13.3.13 Add ..... | 59 | +| 13.3.14 Subtract..... | 59 | +| 13.3.15 Multiply ..... | 60 | +| 13.3.16 Divide ..... | 60 | +| 13.3.17 Negate..... | 60 | +| 13.3.18 Remainder..... | 61 | +| 13.3.19 Duplicate..... | 61 | +| 13.3.20 Convert ..... | 61 | +| 13.3.21 Jump on true ..... | 62 | +| 13.3.22 Jump on false ..... | 62 | +| 13.3.23 Jump ..... | 63 | +| 13.3.24 Shift ..... | 63 | +| 13.3.25 Get object reference..... | 63 | +| 13.3.26 Long jump on true ..... | 64 | +| 13.3.27 Long jump on false ..... | 64 | +| 13.3.28 Long jump..... | 65 | +| 13.3.29 Call..... | 65 | +| 13.3.30 External call..... | 66 | + +| | Page | +|--------------------------------------------------------------------------|-------------| +| 13.3.31 Push ..... | 68 | +| 13.3.32 Push reference..... | 68 | +| 13.3.33 Push immediate..... | 68 | +| 13.3.34 Pop ..... | 69 | +| 13.3.35 Pop reference ..... | 69 | +| 13.3.36 Pop contents..... | 69 | +| 13.3.37 Allocate..... | 70 | +| 13.3.38 Increment ..... | 70 | +| 13.3.39 Decrement..... | 71 | +| 13.3.40 Get ..... | 71 | +| 13.3.41 Get contents ..... | 72 | +| 13.3.42 Set ..... | 73 | +| 13.3.43 Set contents..... | 74 | +| 13.4 Type conversion rules ..... | 75 | +| 13.4.1 Reversible conversions ..... | 75 | +| 13.4.2 Lossless extensions..... | 75 | +| 13.4.3 Lossy extensions..... | 76 | +| 13.4.4 Truncations to boolean ..... | 76 | +| 13.4.5 Truncations between integer or between floating-point types ..... | 76 | +| 13.4.6 Truncations from floating-point to integer ..... | 76 | +| 14 IDL mapping to MHEG-SIR..... | 76 | +| 14.1 IDL specifications ..... | 77 | +| 14.2 IDL interfaces and modules ..... | 77 | +| 14.3 IDL operations ..... | 77 | +| 14.3.1 Operation name..... | 77 | +| 14.3.2 Operation parameters..... | 77 | +| 14.3.3 Implicit parameter..... | 77 | +| 14.3.4 Return value..... | 78 | +| 14.4 IDL attributes ..... | 78 | +| 14.4.1 Accessor..... | 78 | +| 14.4.2 Modifier ..... | 78 | +| 14.4.3 Readonly attribute..... | 78 | +| 14.5 IDL inherited operations ..... | 78 | +| 14.6 IDL exceptions..... | 78 | +| 14.6.1 Exception name ..... | 78 | +| 14.6.2 Exception members ..... | 78 | +| 14.6.3 Implicit member..... | 79 | + +| | Page | +|-------------------------------------------------------------|-------------| +| 14.7 IDL types..... | 79 | +| 14.7.1 char type..... | 79 | +| 14.7.2 enum type..... | 79 | +| 14.7.3 Constructed types..... | 79 | +| 14.7.4 any type..... | 80 | +| 14.7.5 Restrictions on types..... | 80 | +| 14.8 IDL constants ..... | 80 | +| 15 The MHEG-3 API..... | 80 | +| 15.1 ScriptInterpreter object ..... | 81 | +| 15.1.1 kill operation..... | 81 | +| 15.1.2 prepare operation ..... | 81 | +| 15.2 MhScript object..... | 82 | +| 15.2.1 destroy operation ..... | 82 | +| 15.2.2 new operation ..... | 82 | +| 15.3 RtScript object ..... | 83 | +| 15.3.1 delete operation..... | 83 | +| 15.3.2 setPriority operation..... | 83 | +| 15.3.3 getPriority operation ..... | 84 | +| 15.3.4 setData operation ..... | 84 | +| 15.3.5 getData operation..... | 84 | +| 15.3.6 allocate operation..... | 85 | +| 15.3.7 free operation..... | 85 | +| 15.3.8 stop operation ..... | 86 | +| 15.3.9 reInit operation..... | 86 | +| 15.3.10 getRtScriptStatus operation ..... | 87 | +| 15.3.11 open operation ..... | 87 | +| 15.4 RoutineInvocation object..... | 87 | +| 15.4.1 close operation..... | 87 | +| 15.4.2 routine_id readonly attribute..... | 88 | +| 15.4.3 setParameter operation..... | 88 | +| 15.4.4 getPrototype operation..... | 89 | +| 15.4.5 run operation..... | 89 | +| 15.4.6 reset operation..... | 90 | +| 15.4.7 getInvocationStatus operation ..... | 90 | +| Annex A – ASN.1 specification of interchanged scripts ..... | 90 | + +| | Page | +|-----------------------------------------------------------------------------------------------------------------|-------------| +| Annex B – Coded representation of interchanged scripts ..... | 94 | +| B.1 Coding for interchanged scripts ..... | 94 | +| B.2 Coding for the program code ..... | 94 | +| B.2.1 Instruction op-codes..... | 95 | +| B.2.2 Instruction operands..... | 95 | +| Annex C – MHEG-SIR predefined elements..... | 99 | +| C.1 Predefined types..... | 100 | +| C.1.1 Primitive types..... | 100 | +| C.1.2 MHEG API types..... | 100 | +| C.2 Predefined functions ..... | 101 | +| C.2.1 MHEG API operations ..... | 101 | +| C.2.2 MHEG-3 API operations ..... | 101 | +| C.3 Predefined messages ..... | 102 | +| C.3.1 MHEG-3 API operations ..... | 102 | +| C.3.2 The InstructionExecutionError exception..... | 102 | +| C.3.3 MHEG-3 API exceptions..... | 103 | +| C.3.4 MHEG API exceptions..... | 103 | +| Annex D – IDL Platform mapping specification form..... | 103 | +| Annex E – MHEG API definition process..... | 105 | +| E.1 Generic API definition framework ..... | 105 | +| E.1.1 MHEG elements input to MHEG API definition process ..... | 105 | +| E.1.2 IDL elements output by MHEG API definition process..... | 105 | +| E.1.3 Requirements on the MHEG API definition process ..... | 105 | +| E.1.4 General structure of the MHEG API ..... | 107 | +| E.1.5 IDL non-object datatype definition..... | 107 | +| E.1.6 IDL interface definition ..... | 112 | +| E.1.7 IDL attribute definition..... | 113 | +| E.1.8 IDL operation definition ..... | 113 | +| E.1.9 IDL exception definition..... | 116 | +| E.2 MHEG API mapping to MHEG-SIR ..... | 117 | +| Annex F – IDL specification of the MHEG-3 API ..... | 118 | +| Annex G – Relationships with other ITU-T Recommendations of the T.170-Series (and parts of ISO/IEC 13522) ..... | 119 | +| G.1 Relationships with ITU-T Rec. T.171 (and ISO/IEC 13522-1) ..... | 119 | +| G.2 Relationships with ITU-T Rec. T.172 (and ISO/IEC 13522-5) ..... | 120 | +| Appendix I – MHEG-SIR syntax (EBNF notation) ..... | 121 | + +| | | +|-------------------------------------------------------------------------|-----| +| Appendix II – Textual notation for MHEG-SIR scripts..... | 123 | +| Appendix III – MHEG entities..... | 126 | +| III.1 MHEG objects ..... | 126 | +| III.2 Mh-objects ..... | 127 | +| III.3 Rt-objects ..... | 127 | +| III.4 Interchanged MHEG objects..... | 127 | +| Appendix IV – Main features of MHEG-SIR ..... | 128 | +| IV.1 Features of using applications..... | 128 | +| IV.1.1 Manipulation of MHEG entities ..... | 128 | +| IV.1.2 Computations, variable handling and control structures ..... | 128 | +| IV.1.3 External device control ..... | 128 | +| IV.1.4 Data acquisition ..... | 129 | +| IV.1.5 Access to external data ..... | 129 | +| IV.1.6 Access to arbitrary external run-time services..... | 129 | +| IV.2 Functional features..... | 129 | +| IV.2.1 Data processing operations ..... | 129 | +| IV.2.2 Access to external data and functions..... | 130 | +| IV.3 Technical features..... | 130 | +| IV.3.1 Hardware independence..... | 131 | +| IV.3.2 Final form representation..... | 131 | +| IV.3.3 Compactness..... | 131 | +| IV.3.4 Ease of implementation ..... | 132 | +| IV.3.5 Interpretation efficiency..... | 132 | +| IV.3.6 Openness and extensibility ..... | 132 | +| IV.3.7 Non-revisability ..... | 132 | +| IV.3.8 Provisions for real-time interchange..... | 132 | +| IV.3.9 Semantic validation for quality of service purposes..... | 132 | +| IV.3.10 Syntax checkability (with regard to contamination hazards)..... | 132 | +| IV.3.11 Non-proprietary representation..... | 133 | +| IV.3.12 Secure script processing ..... | 133 | + +## Introduction + +This Recommendation, which is equivalent to ISO/IEC 13522-3, is a generic Recommendation which extends the coded representation of the MHEG script object class defined in ITU-T Recommendations of the T.170-Series, including T.171 and T.172. It specifies the MHEG script interchange representation (MHEG-SIR) for the contents of script objects, i.e. the encoding of the script data component of the MHEG script class. + +The ITU-T Recommendations of the T.170-Series include the following approved Recommendations: + +- T.170 (1998), *Framework of the T.170-Series of Recommendations*. +- T.171 (1996), *Protocols for interactive audiovisual services: Coded representation of multimedia and hypermedia objects*. +- T.172 (1998), *MHEG-5 – support for base-level interactive applications*. +- T.173 (1997), *MHEG-3 script interchange representation*. +- T.174 (1996), *Application programming interface (API) for MHEG-1*. +- T.175 (1998), *Application programming interface (API) for MHEG-5*. +- T.176 (1998), *API for digital storage media command and control (DSM-CC)*. + +Some ITU-T Recommendations of the T.170-Series are equivalent to ISO/IEC 13522 parts. This standard consists of the following parts, under the general title: Information technology – Coding of multimedia and hypermedia information: + +- Part 1: Base notation; +- Part 3: MHEG script interchange representation; +- Part 4: Registration procedure for MHEG format identifier; +- Part 5: Support for base-level interactive applications; +- Part 6: Support for enhanced interactive applications. + +Annexes A to G form an integral part of this Recommendation. Appendices I to IV are for information only. + + + +## Recommendation T.173 + +### MHEG-3 SCRIPT INTERCHANGE REPRESENTATION + +(Geneva, 1997) + +#### 1 Scope + +The scope of this Recommendation is to extend the coded representation of the MHEG script object class defined by ITU-T Rec. T.171 (and ISO/IEC 13522-1) [5] and ITU-T Rec. T.172 (and ISO/IEC 13522-5) [7]. + +This Recommendation specifies the MHEG Script Interchange Representation (MHEG-SIR) for the contents of script objects, i.e. the encoding of the script data component of the MHEG script class. + +MHEG engines are system or application components that handle, interpret and present MHEG objects. This Recommendation also specifies the semantics of interchanged scripts. These semantics are defined in terms of minimum requirements on the behaviour of MHEG engines that support the interpretation of interchanged scripts. + +This Recommendation is applicable to all applications that interchange multimedia and hypermedia information. + +#### 2 Normative references + +The following ITU-T Recommendations, and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. + +- [1] ITU-T Recommendation X.680 (1994) | ISO/IEC 8824-1:1995, *Information technology – Abstract Syntax Notation One (ASN.1): Specification of basic notation*. +- [2] ITU-T Recommendation X.690 (1994) | ISO/IEC 8825-1:1995, *Information technology – ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)*. +- [3] ITU-T Recommendations X.290 to X.296 (1995), *OSI conformance testing methodology and framework for protocol Recommendations for ITU-T applications*. +ISO/IEC 9646 Parts 1 to 5, *Information technology – Open Systems Interconnection – Conformance testing methodology and framework*. +*Part 1: 1994, General concepts.* +*Part 2: 1994, Abstract Test Suite specification.* +*Part 3: 1992, The Tree and Tabular Combined Notation (TTCN).* +*Part 4: 1994, Test scalization.* +*Part 5: 1994, Requirements on test laboratories and clients for the conformance assessment process.* + +- [4] ISO/IEC 10646-1:1993, *Information technology – Universal Multiple-Octet Coded Character Set (UCS) – Part 1: Architecture and Basic Multilingual Plane*. +- [5] ITU-T Recommendation T.171 (1996), *Protocols for interactive audiovisual services: Coded representation of multimedia and hypermedia objects*. +ISO/IEC 13522-1:1997, *Information technology – Coding of multimedia and hypermedia information: – Part 1: MHEG object representation – Base Notation (ASN.1)*. +- [6] ISO/IEC 13522-4:1996, *Information technology – Coding of multimedia and hypermedia information – Part 4: MHEG registration procedure*. +- [7] ITU-T Recommendation T.172 (1998), *MHEG-5 – support for base-level interactive applications*. +ISO/IEC 13522-5:1997, *Information technology – Coding of multimedia and hypermedia information – Part 5: Support for base-level interactive applications*. +- [8] ISO/IEC 147501, *Information technology – Open Distributed Processing – Interface Definition Language*. (Formerly ISO/IEC 14750-1.) +- [9] IEEE 754:1985, *IEEE standard for binary floating-point arithmetic*. + +### 3 Definitions + +#### 3.1 Definitions + +For the purposes of this Recommendation, the definitions given in ITU-T Rec. X.680 | ISO/IEC 8824-1 [1], ITU-T Rec. X.690 | ISO/IEC 8825-1 [2] and the following definitions apply: + +**3.1.1 application programming interface (API):** Boundary across which a software application uses facilities of programming languages to invoke software services. These facilities may include procedures or operations, shared data objects and resolution of identifiers. + +**3.1.2 attribute:** + +- 1) MHEG attribute (see ISO/IEC 13522-1 [5]); +- 2) IDL attribute (q.v.). + +**3.1.3 conforming MHEG-3 engine:** MHEG-3 engine whose implementation conforms to the provisions of this Recommendation. + +**3.1.4 conforming MHEG-3 interchanged script:** Interchanged script that conforms to the provisions of this Recommendation. + +**3.1.5 conforming MHEG-3 object:** MHEG script object whose coded representation conforms to the provisions of this Recommendation. + +**3.1.6 frame:** Record of elements on the call stack that define an execution context; one such record is pushed onto the call stack every time a routine is called, to memorize the current execution context; one is popped from the call stack when the routine is returned from, to restore the execution context at the time of calling. + +**3.1.7 hypermedia (*adj.*):** Featuring access monomedia and multimedia information by interaction with explicit links. + +--- + +1 Presently at the stage of draft. + +- 3.1.8 interchanged script:** The coded representation of the "script data" attribute of an MHEG script object. +- 3.1.9 interface definition language (IDL):** Formal notation that is used to specify types and objects through the definition of the interface that they provide, as defined by ISO/IEC 14750-1 [8]. +- 3.1.10 IDL attribute:** Named, typed association between an object and a value; it is declared as part of an IDL interface; it is made visible to clients as a pair of operations: an accessor (get) and a modifier (set); if it is read-only, it only provides an accessor. +- 3.1.11 IDL exception:** Message that can be raised when an exceptional condition occurs during the performance of the request to an IDL operation; it is defined in an IDL module and may have members, which are returned to the caller together with the message identifier. +- 3.1.12 IDL instance:** Object that provides the operations, signatures and semantics specified by an IDL interface; its creation and management is implementation-specific. +- 3.1.13 IDL interface:** Description, using IDL, of a set of operations that a client may request of an IDL object. +- 3.1.14 IDL object:** Identifiable, encapsulated entity that provides one or more services which can be requested by a client. +- 3.1.15 IDL operation:** Service that can be requested and is provided by an IDL object; it is defined within an IDL interface by a name, a signature which defines the type of its parameters and return value, and the list of exceptions that its invocation may raise. +- 3.1.16 mh-script:** Internal representation, within an MHEG engine, of an "available" MHEG script object. +- 3.1.17 MHEG action:** Operation that applies to MHEG objects and consists of sequential and/or parallel combinations of MHEG elementary actions. +- 3.1.18 MHEG action object:** MHEG object that describes MHEG actions. +- 3.1.19 MHEG application:** Application that involves the interchange of MHEG objects within itself or with another application. +- 3.1.20 MHEG conforming object:** Information object whose coded representation conforms to the provisions of one of the parts of ISO/IEC 13522. +- 3.1.21 MHEG elementary action:** One of the basic operations applying to MHEG objects; it maps one MHEG API primitive. +- 3.1.22 MHEG engine:** Process or set of processes able to interpret MHEG objects. +- 3.1.23 MHEG entity:** Any MHEG object, rt-object, content data, script data, socket, channel or other construction defined by ISO/IEC 13522. +- 3.1.24 MHEG link:** MHEG object that defines spatio-temporal relationships among MHEG objects expressed in terms of trigger conditions and actions. +- 3.1.25 MHEG object:** Coded representation of an instance of an MHEG object class. +- 3.1.26 MHEG script class:** MHEG class defining a structure to interchange script data in a specified encoded form. +- 3.1.27 MHEG script object:** The coded representation of an instance of an MHEG script class. +- 3.1.28 MHEG API:** The API provided by an MHEG engine to MHEG applications for the manipulation of MHEG objects. +- 3.1.29 MHEG-3 (*adj.*):** Applies to entities that conform to the provisions of this Recommendation. + +**3.1.30 MHEG-3 application:** MHEG application that interchanges scripts within itself and/or with other applications as the "script data" component of MHEG script objects, according to the representation specified by this Recommendation. + +**3.1.31 MHEG-3 engine:** MHEG engine that processes and interprets MHEG-SIR interchanged scripts. + +**3.1.32 MHEG-3 profile:** Profile of Recommendation T.173. + +**3.1.33 MHEG-SIR:** + +- 1) The script interchange representation defined by this Recommendation. +- 2) (adj.) Applies to an entity defined as part of this Script Interchange Representation. + +**3.1.34 (MHEG-SIR) call stack:** Stack that is associated with each running rt-script by the MHEG-SIR virtual machine and that contains a call frame for each active function invocation. + +**3.1.35 MHEG-SIR code:** Encoded sequence of MHEG-SIR instructions. + +**3.1.36 (MHEG-SIR) constant:** Static, typed, named value which is declared within an interchanged script and whose value is globally accessible and unchanged throughout the execution of the script. + +**3.1.37 (MHEG-SIR) constructed type:** Type described as a combination of other types using one of the following constructors: sequence, string, array, union, structure. + +**3.1.38 (MHEG-SIR) data identifier:** Integer that uniquely identifies the name of a data element of an interchanged script (constant, global variable, dynamic variable, local variable). + +**3.1.39 (MHEG-SIR) exception:** Message triggered during the invocation of a service. + +**3.1.40 (MHEG-SIR) function:** Named code sequence whose execution may be invoked by an interchanged script; it may be a routine, a predefined function or a service. + +**3.1.41 (MHEG-SIR) function identifier:** Integer that uniquely identifies a function within an interchanged script. + +**3.1.42 (MHEG-SIR) global variable:** Variable with global scope. + +**3.1.43 (MHEG-SIR) instruction:** Elementary unit of code of an MHEG-SIR interchanged script; it consists of an op-code followed by zero or more operands. + +**3.1.44 (MHEG-SIR) instruction execution unit:** Within an MHEG-SIR script interpreter, virtual processing unit that executes an MHEG-SIR instruction. + +**3.1.45 MHEG-SIR interchanged script:** Interchanged script coded according to MHEG-SIR. + +**3.1.46 (MHEG-SIR) local variable:** Variable with local scope within a routine. + +**3.1.47 (MHEG-SIR) message:** Event that may be received by the script interpreter during the execution of the script; it may be either predefined (MHEG API exception, MHEG-3 API operation and exception, internal exception) or declared within an interchanged script (exception provided by an external interface). + +**3.1.48 (MHEG-SIR) message identifier:** Integer that uniquely identifies a message within an interchanged script. + +**3.1.49 (MHEG-SIR) message queue:** Queue that is associated with each running rt-script by the MHEG-SIR virtual machine and that contains the messages targeted at the rt-script. + +**3.1.50 (MHEG-SIR) object reference:** MHEG-SIR value that represents an IDL instance and that is passed as the parameter of an external call to request a service from this instance. + +- 3.1.51 (MHEG-SIR) operand:** Parameter of an instruction; it is encoded next to the instruction's op-code. +- 3.1.52 (MHEG-SIR) package:** Set of external functions that are provided by a module of the run-time environment and that are accessible to an rt-script and declared within an interchanged script; it is composed of services and exceptions. +- 3.1.53 (MHEG-SIR) parameter:** Piece of data exchanged with a function call, a message or an instruction. +- 3.1.54 (MHEG-SIR) parameter stack:** Stack that is associated with each running rt-script by the MHEG-SIR virtual machine and that is used to provide parameters to and retrieve results of instructions. +- 3.1.55 (MHEG-SIR) predefined type:** A type whose description and identifier are predefined by this Recommendation and thus need not be declared within interchanged scripts; it may be either a primitive type or a constructed type. +- 3.1.56 (MHEG-SIR) primitive type:** Basic predefined type, as opposed to constructed type. +- 3.1.57 (MHEG-SIR) routine:** Function that is declared within an interchanged script together with the virtual machine code that defines its semantics. +- 3.1.58 (MHEG-SIR) rt-script execution unit:** Within an MHEG-SIR script interpreter, virtual processing unit that executes script code. +- 3.1.59 (MHEG-SIR) script interpreter:** The part of an MHEG-3 engine, that handles and interprets interchanged scripts. +- 3.1.60 (MHEG-SIR) service:** External function that is declared within an interchanged script and whose implementation is made accessible to an rt-script by the run-time environment on the execution platform. +- 3.1.61 (MHEG-SIR) variable:** Within the MHEG-SIR virtual machine, named, typed memory unit whose value may be changed at any time when its scope is active and whose most recent value may be read. +- 3.1.62 (MHEG-SIR) virtual machine:** Abstract description of the memory units and instruction execution engine of an MHEG-SIR script interpreter. +- 3.1.63 multimedia (*adj.*):** That handles several types of representation media. +- 3.1.64 multimedia and hypermedia application:** Application that features presentation of multimedia information to the user and interactive navigation across this information by the user. +- 3.1.65 multimedia application:** Application that features presentation of multimedia information to the user. +- 3.1.66 platform mapping specification:** Specification of how MHEG-3 engine implementations shall map IDL specifications to run-time environment components on one type of platform. +- 3.1.67 queue:** Collection of elements that are inserted and removed in First-In First-Out (FIFO) order. +- 3.1.68 rt-script:** Run-time instance (or copy) of an mh-script, created by an MHEG engine. +- 3.1.69 scope:** Context of reference for a variable; if it is global, the variable may be referenced by any script instruction; if it is local, the variable may only be referenced in the local execution context. + +**3.1.70 scripting language:** Programming language intended for easy and rapid design of applications by non-professional programmers. + +**3.1.71 script interchange representation (SIR):** Coded representation used by an application to interchange scripts for the purpose of implementing dynamic behaviour. + +**3.1.72 stack:** Collection of elements that are inserted (pushed) and removed (popped) in Last-In First-Out (LIFO) order. + +## **3.2 Abbreviations** + +This Recommendation uses the following abbreviations: + +| | | +|-------|----------------------------------------------------------------------------------| +| API | Application Programming Interface | +| ASN.1 | Abstract Syntax Notation One | +| CORBA | Common Object Request Broker Architecture | +| CS | Call Stack | +| CT | Constant Table | +| DER | Distinguished Encoding Rules | +| DID | Data Identifier | +| DT | Data Table | +| EBNF | Extended Backus-Naur Form | +| ER | Error Register | +| ETR | ETSI Technical Report | +| FID | Function Identifier | +| FIFO | First-In First-Out | +| FP | Frame Pointer | +| FR | Function Register | +| GT | Global variable definition Table | +| HT | Handler definition Table | +| IDL | Interface Definition Language | +| IEC | International Electrotechnical Commission | +| IP | Instruction Pointer | +| IR | Instruction Register | +| ISO | International Organization For Standardization | +| ITU-T | International Telecommunication Union – Telecommunication Standardization Sector | +| JTC | Joint Technical Committee | +| LIFO | Last-In First-Out | +| LT | Local variable Table | +| MHEG | Multimedia and Hypermedia information coding Experts Group | + +| | | +|-------------|--------------------------------------------------------------------------| +| MID | Message IDentifier | +| MPEG/DSM-CC | Moving Picture Experts Group – Digital Storage Media Command and Control | +| MQ | Message Queue | +| PID | Package IDentifier | +| PS | Parameter Stack | +| PT | Package definition Table | +| QP | Queue Pointer | +| rt | Run-time | +| RT | Routine definition Table | +| SIR | Script Interchange Representation | +| SP | Stack Pointer | +| ST | Service definition Table | +| TID | Type IDentifier | +| TLV | Type-Length-Value | +| TT | Type definition Table | +| VT | Variable Table | +| XT | eXception definition Table | + +#### 4 General + +ITU-T T.170-Series (and ISO/IEC 13522) specifies the coded representation of multimedia/hypermedia information objects (MHEG objects) for interchange as final form units within or across services and applications, by any means of interchange including local area networks, wide area telecommunication or broadcast networks, storage media, etc. + +MHEG objects are usually produced by computer tools taking as a source form multimedia applications designed using multimedia scripting languages. In this context, one of the MHEG object classes, the script class, is intended to complement the other MHEG classes in expressing the functionality commonly supported by scripting languages. Script objects express more powerful control mechanisms and describe more complex relationships among MHEG objects than can be expressed by MHEG action and link objects alone. Furthermore, script objects express access and interaction with external services provided by the run-time environment. + +Other Recommendations of the T.170-Series define the coded representation for script objects in an open manner so that script objects may encapsulate either standardized or proprietary script code. Script objects encapsulate scripts that may be encoded in any encoding format as registered according to ISO/IEC 13522-4 [6]. + +#### 5 Conformance + +This Recommendation defines conformance requirements + +- on information objects, i.e. MHEG script objects; +- on implementations, i.e. MHEG engine implementations. + +## **5.1 Information object conformance** + +A conforming MHEG-3 script object shall meet all of the following criteria: + +- 1) its coded representation shall conform to the provisions of the ITU-T T.170-Series (and of the parts of ISO/IEC 13522); +- 2) its coded representation shall encapsulate a conforming MHEG-3 interchanged script. + +The information object conformance is evaluated on the information objects that are interchanged in the purpose of their execution on a terminal. + +### **5.1.1 Profiles** + +This Recommendation defines no profiles. + +NOTE 1 – However, MHEG-3 profiles may be defined by other standards or by other parts of ISO/IEC 13522. In accordance with the profile definition framework, standardized MHEG-3 profiles should be at least as constraining; information objects claiming conformance to such profiles should at least conform to this Recommendation. + +An MHEG-3 profile should define all of the following: + +- a profile of the MHEG-SIR virtual machine defined by this Recommendation; +- a profile of IDL, together with its mapping to MHEG-SIR, for the expression of interface between scripts and the external environment; +- an API for the manipulation of MHEG objects defined by ITU-T T.170-Series (and of the parts of ISO/IEC 13522), together with a mapping of this interface to MHEG-SIR. + +NOTE 2 – According to ISO Standards, MHEG-3 profiles should ensure upward compatibility of the ASN.1 encoding, so that interchanged scripts conforming to an MHEG-3 profile also conform to this Recommendation. + +### **5.1.2 Encoding** + +A conforming MHEG-3 interchanged script shall be encoded according to the encoding rules defined by Annex B. + +### **5.1.3 Syntax** + +A conforming MHEG-3 interchanged script shall conform to the ASN.1 syntax defined by Annex A. + +### **5.1.4 Semantics** + +A conforming MHEG-3 interchanged script shall only include semantically valid declarations and instruction sequences as defined by clauses 12 and 13. + +## **5.2 Implementation conformance** + +An implementation of this Recommendation is an MHEG-3 engine. + +A conforming MHEG-3 engine shall support the interpretation of conforming MHEG-3 script objects. + +This Recommendation defines the semantics of MHEG-3 interchanged scripts. This implies conformance requirements not on information objects, but on the behaviour of MHEG-3 engines. + +NOTE 1 – Although a conforming script might not realize the semantics implied by its designer, the way conforming engines behave in interpreting this script is predictable. + +NOTE 2 – This Recommendation does not consider conformance for a system, an engine or a process as far as it is not related to the interpretation of interchanged scripts. + +### 5.2.1 Conformance requirements + +A conforming MHEG-3 engine shall meet all of the following criteria: + +- 1) it shall parse and interpret conforming MHEG-3 interchanged scripts according to the virtual machine behaviour defined in this Recommendation (see clause 9); +- 2) it shall support communication with the run-time environment and with MHEG objects according to the IDL mapping behaviour defined in this Recommendation (see clauses 10, 11 and 14); +- 3) it shall provide the MHEG-3 API defined in this Recommendation (see clause 15 and Annex F); +- 4) for the purpose of manipulation of MHEG objects by interchanged scripts, it shall support an MHEG API and its mapping according to the framework defined in this Recommendation (see Annex E); +- 5) for the purpose of communication with the run-time environment, it shall support a platform mapping specification according to the framework defined in this Recommendation (see Annex D); +- 6) it may provide additional functions or facilities not required by this Recommendation or by the platform mapping specification. Each such non-standard extension shall be identified as such in the system documentation. + +### 5.2.2 Conformance documentation + +A conformance document with the following information shall be available for an implementation claiming conformance to this Recommendation. The conformance document shall meet all of the following criteria: + +- 1) it shall list all the mandatory features required by this Recommendation, with reference to the appropriate clauses and subclauses; +- 2) it shall either include the platform mapping specification to which the implementation conforms or reference a registered platform mapping specification in an unambiguous way; +- 3) it shall contain a statement that indicates the full names, numbers, and dates of the standards that apply; +- 4) it shall state which of the optional features defined in this Recommendation and in the platform mapping specification are supported by the implementation; +- 5) it shall describe the behaviour of the implementation for all implementation-defined features defined in this Recommendation and in the platform mapping specification. This requirement shall be met by listing these features and by providing either a specific reference to the system documentation or full syntax and semantics of these features. The conformance document may specify the behaviour of the implementation for those features where this Recommendation or the platform mapping specification states that implementations may vary or where features are identified as undefined or unspecified. + +No specifications other than those specified by this Recommendation and the platform mapping specification shall be present in the conformance document. + +## 5.3 Application conformance + +An application of this Recommendation (called MHEG-3 application) is an MHEG application that interchanges scripts within itself and/or with other applications as the "script data" component of MHEG script objects according to the encoded representation specified by this Recommendation. + +## 5.4 Test Methods + +Any measurement of conformance to this Recommendation shall be performed using test methods that conform to ITU-T X.290-Series (and ISO/IEC 9646) [3]. + +## 6 Overview + +This Recommendation extends the provisions of other Recommendations of ITU-T T.170-Series (and other parts of ISO/IEC 13522) so that MHEG objects and applications support functionality of multimedia scripting languages in a standard way. Considering the functionality supported by other Recommendations of ITU-T T.170-Series (and other parts of ISO/IEC 13522), these extensions are divided in two main topics: + +- data processing operations (see 6.2); +- access to external data and functions (see 6.3). + +For the support of both topics, this Recommendation specifies: + +- complete and detailed provisions for the encoding of interchanged scripts; +- the required behaviour of a script interpreter. + +### 6.1 Description methodology + +For the description of these provisions, this Recommendation follows a methodology that considers four description levels: + +- level a): informal text description; +- level b): precise description of semantics; +- level c): formal description of syntax; +- level d): formal description of encoding. + +These levels are used in the following clauses as follows: + +- level a): clauses 8 to 11; +- level b): clauses 12 to 15; +- level c): Annexes A, E, F, G; +- level d): Annexes B, C. + +NOTE – Informative Appendices I and II also use level c) description. + +### 6.2 Data processing operations + +To deal with data processing operations, MHEG-SIR defines the structure of interchanged scripts that consist of data declarations and function declarations, the latter encapsulating sequences of instructions. + +Clause 8 defines the elements of the MHEG-SIR virtual machine code. + +Clause 9 specifies the MHEG-SIR virtual machine, i.e. a model of how MHEG-SIR script interpreters shall perform interpretation of MHEG-SIR script code. This virtual machine is used afterwards to describe the semantics of MHEG-SIR instructions. Clause 9 states requirements on the functionality that script interpreters shall provide; however, it does not specify how to implement this functionality. + +Clause 12 defines the declarations of MHEG-SIR interchanged scripts. It specifies their structure, i.e. the way they shall be represented, and their semantics, i.e. the way they shall be interpreted by + +MHEG-SIR script interpreters. The semantics are specified using the virtual machine formalism introduced in clause 9. + +Clause 13 defines the MHEG-SIR instructions. It specifies their structure, i.e. the way they shall be represented, and their semantics, i.e. the way they shall be interpreted by MHEG-SIR script interpreters. These semantics are specified using the virtual machine formalism introduced in clause 9. + +Annex A formally defines the precise syntax of interchanged scripts using the ASN.1 notation. + +Annex B formally defines the encoding of interchanged scripts. + +Annex C lists the predefined elements of MHEG-SIR and defines their encoding. + +Annex G formally defines the instantiation of this Recommendation to ITU-T Recs. T.171 (and ISO/IEC 13522-1) and T.172 (and ISO/IEC 13522-5), i.e. the MHEG objects in these parts to which MHEG-SIR applies, and the way it applies to them. + +### **6.3 Access to external data and functions** + +To deal with access to external data and functions, MHEG-SIR uses IDL to describe interfaces in an abstract, language-independent way and thus unify the way external data and functions are viewed by script interpreters. + +In the MHEG-SIR context, IDL is used to separate clearly the way (MHEG-SIR specific) the use of external data or functions is expressed by interchanged scripts from the way (at least platform-dependent, and maybe application-dependent) these data or functions are provided by the external environment. MHEG-SIR thus defines how the interfaces are used, while the application is responsible for defining how they are provided. + +To allow script interpreters to manipulate MHEG entities and exchange information with them, MHEG-3 engines provide script interpreters with access to the MHEG entities (data) and invocation of the MHEG actions (functions) through an MHEG API defined using IDL. The MHEG types and actions are predefined in MHEG-SIR to achieve compact coding and efficient interpretation of MHEG object manipulation. + +To allow script interpreters to co-operate with the run-time environment, the run-time environment provides access to its data and functions according to a platform mapping specification of IDL. This specification describes how IDL operations need to be provided on a particular platform so that MHEG-3 engines are able to use them as external services. + +NOTE – Packages may be provided in the form of libraries, device drivers, operating system components, processes, telecommunication services, etc. + +Clause 7 describes assumptions on the structure of MHEG-3 engines and their relationships with their environment. + +Clause 10 describes the general mechanisms used to access to external data and functions provided by the run-time environment. + +Clause 11 describes the general mechanisms used to manipulate MHEG objects. + +Clause 14 specifies the IDL mapping for MHEG-SIR, i.e. the mechanisms used by the MHEG-SIR representation to describe IDL packages and invoke IDL operations. + +Clause 15 specifies the structure and semantics of the MHEG-3 API, i.e. the set of operations that may be used to manipulate scripts. + +Annex D specifies the IDL platform mapping specification form, i.e. the template for the document that need be filled in and registered for each platform type, to specify the platform-specific + +provisions that services provided by the run-time environment on this platform shall fulfil, and to which MHEG-3 engines shall conform so that they are able to co-operate with services provided by the run-time environment on this platform and therefore to interpret scripts that call upon such services. + +Annex E specifies the framework that shall be used to define an MHEG API using IDL and the procedure that shall be followed to map it to MHEG-SIR. + +Annex F defines the precise syntax of the MHEG-3 API using the IDL notation. + +## **7 MHEG/MHEG-3 relationship** + +This clause introduces general assumptions about MHEG-3 engines, which are used afterwards to describe the performance of a script interpreter and its relationships with its external environment. + +MHEG-3 engines shall provide the functionality described hereafter in some way, in order to behave as expected as far as interpretation of interchanged scripts is concerned. + +However, there is no requirement on MHEG-3 engines to implement this functionality as described. + +NOTE – For instance, the MHEG-3 engine functional components described thereafter need not correspond to actual (e.g. software) components of MHEG-3 engine implementations. + +### **7.1 MHEG entities** + +MHEG-3 engines handle MHEG entities: MHEG objects, mh-objects, rt-objects, interchanged MHEG objects, sockets, channels. + +NOTE – MHEG entities are described in more detail in Appendix III. + +### **7.2 Functional entities** + +MHEG-3 engines may be viewed as consisting of the following functional components: + +- MHEG object parser: parses interchanged MHEG objects and transforms them into mh-objects under control of the mh-object manager; +- mh-object manager: controls the life cycle and allows access to all mh-objects; +- rt-object manager: controls the life cycle and allows access to all rt-objects; +- reference resolver: transforms an MHEG reference into a usable identifier or handle; +- link handler: watches active links and triggers the corresponding actions when their conditions become true; +- action interpreter: interprets MHEG elementary actions; +- script interpreter: parses MHEG-SIR interchanged scripts and interprets rt-scripts; provides access to the run-time environment; +- presentation agent: interface with the presentation environment; orders presentation of rt-contents; receives user selections and modifications; +- access agent: interface with the communication environment; provides access to interchanged MHEG objects and to content data. + +### **7.3 MHEG-SIR script interpreter** + +Within an MHEG-3 engine, the script interpreter shall be responsible for the following: + +- parsing interchanged scripts (provided by the MHEG object parser); + +- preparing the appropriate data structures for further execution of rt-scripts; +- executing script code; +- realizing the default effect of MHEG actions targeted at mh-scripts or rt-scripts; +- invoking the appropriate handler (in the script program) for these MHEG actions; +- forwarding MHEG elementary actions invoked by the script program to the action interpreter; +- managing interchange with the run-time environment (locating and loading packages, invoking services, receiving messages, passing data) using the appropriate platform-specific communication mechanisms. + +## **8 Elements of MHEG-SIR** + +This clause describes the main elements of MHEG-SIR and how interchanged scripts shall use them. + +The entities that are declared and manipulated by MHEG-SIR interchanged scripts are: + +- data types; +- data; +- functions; +- messages. + +These concepts are defined in the following subclauses; however, the detailed structure of their declarations is specified in clause 12. + +### **8.1 Data types** + +Data types are used to describe the structure of: + +- the script's own data (constants and variables); +- the parameters and return values of the script's routines; +- the parameters and return values of external functions; +- the parameters of messages handled by scripts. + +As scripts need adapt themselves to the signature of functions that may be provided by the external environment, MHEG-SIR defines a wide range of types corresponding to the IDL data types. + +The encoding of data type definitions in an interchanged script is defined by Annex A. This Recommendation imposes no requirement on the way MHEG-3 engines represent these data types. + +The MHEG-SIR uses two kinds of data types: + +- predefined types (see 8.1.1); +- declared types (see 8.1.2). + +All types may be referenced in a unique, unambiguous way by their type identifier. + +#### **8.1.1 Predefined types** + +Predefined types may be either primitive or constructed types. + +Predefined types have predefined type identifiers and therefore need not be declared by interchanged scripts. The list of predefined types and their identifiers is given in Annex C. + +### 8.1.1.1 Primitive types + +The primitive types correspond to the IDL primitive types. This is the list of MHEG-SIR primitive types: + +- **void**; +- **octet**; +- **short**; +- **long**; +- **unsigned short**; +- **unsigned long**; +- **float**; +- **double**; +- **boolean**; +- **character**; +- **data identifier**; +- **object reference**. + +For easier reference, primitive types have individual letter codes as indicated by Table 1: + +**Table 1/T.173 – Letter codes of primitive types** + +| Type | Letter code | +|-------------------------|-------------------| +| octet | O | +| short | S | +| long | L | +| unsigned short | W (as Word) | +| unsigned long | U | +| float | F | +| double | D | +| boolean | B | +| character | C | +| data identifier | I (as Identifier) | +| object reference | R (as Reference) | + +#### 8.1.1.1.1 void type + +The **void** type shall only be used to express the type of return value of a function. Functions whose type of return value is **void** do not return any data. An interchanged script shall have no constants or variables of **void** type. The **void** type shall not be used in the definition of constructed types. + +#### 8.1.1.1.2 octet type + +Data whose type is **octet** shall take a numeric value within the range [0 .. 255]. **Octet** variables without explicit initial value shall be initialized to 0. + +#### 8.1.1.1.3 short type + +Data whose type is **short** shall take a signed integer value within the range [−32 768 .. 32 767]. **Short** variables without explicit initial value shall be initialized to 0. + +#### 8.1.1.1.4 long type + +Data whose type is **long** shall take a signed integer value within the range [−2147483648 .. 2147483647]. **Long** variables without explicit initial value shall be initialized to 0. + +#### 8.1.1.1.5 unsigned short type + +Data whose type is **unsigned short** shall take an unsigned integer value within the range [0 .. 65535]. **Unsigned short** variables without explicit initial value shall be initialized to 0. + +#### 8.1.1.1.6 unsigned long type + +Data whose type is **unsigned long** shall take an unsigned integer value within the range [0 .. 4294967295]. **Unsigned long** variables without explicit initial value shall be initialized to 0. + +#### 8.1.1.1.7 float type + +Data whose type is **float** shall take a single-precision floating point value within the range specified by IEEE 754 [9]. **Float** variables without explicit initial value shall be initialized to 0. + +#### 8.1.1.1.8 double type + +Data whose type is **double** shall take a double-precision floating point value within the range specified by IEEE 754 [9]. **Double** variables without explicit initial value shall be initialized to 0. + +#### 8.1.1.1.9 boolean type + +Data whose type is **boolean** shall have either "true" or "false" as their value. **Boolean** variables without explicit initial value shall be initialized to "false". + +#### 8.1.1.1.10 character type + +Data whose type is **character** shall take a character value within the **BMPString** character set as defined by the Basic Multilingual Plane of ISO/IEC 10646-1 [4]. **Character** variables without explicit initial value shall have an undefined initial value. + +Conforming MHEG-3 engines may state that they only adopt a restricted set of characters, e.g. based on the standard collections of Annex A of ISO/IEC 10646-1 [4]. In this case, they shall document these adopted subsets and the level of implementation in the conformance document. + +#### 8.1.1.1.11 data identifier type + +Data whose type is **data identifier** shall take an unsigned integer value within the range [0 .. 65535]. This value is used to identify a constant, global variable, dynamic variable, local variable or routine parameter of the script, as defined by 8.6.2 below. There shall be no constants of **data identifier** type. **Data identifier** variables without explicit initial value shall have an undefined initial value. + +#### 8.1.1.1.12 object reference type + +Data whose type is **object reference** shall take as value a handle that references an IDL object to which services or predefined functions apply. Encoding of object references is defined by the platform mapping specification. There shall be no constants of **object reference** type. The **object reference** type shall not be used in the definition of constructed types. **Object reference** variables without explicit initial value shall have an undefined initial value. + +Object references are used as the implicit first parameter of all external calls to specify the object to which the call applies. Object reference values shall be provided by the external environment, as an output parameter or return value of an **external call (XCALL)** instruction. The **get object reference (GETOR)** instruction is used to get a first object reference on the root object of a given package. The **null** object reference is used to refer to the original object of the MHEG-3 API (instance of **ScriptInterpreter**). + +### 8.1.1.2 Predefined constructed types + +To allow scripts to express manipulation of MHEG data more easily, the MHEG API data types are predefined. + +Although they are not defined within interchanged scripts, predefined constructed types, like declared constructed types, can be expressed using type constructors and type identifiers, as described in 8.1.2. Only predefined type identifiers shall be used to express the structure of predefined constructed types. + +### 8.1.2 Declared constructed types + +Constructed types shall be defined using one constructor and one or several type identifiers identifying either a declared or predefined type. + +The constructor of a constructed type shall be one of the following: + +- **sequence** (see 8.1.2.1); +- **string** (see 8.1.2.2); +- **array** (see 8.1.2.3); +- **structure** (see 8.1.2.4); +- **union** (see 8.1.2.5). + +Declared types are defined within interchanged scripts. + +MHEG-SIR types shall not be redefined in an interchanged script. The structure of a declared type shall not match that of a predefined type or that of another declared type. + +There shall not be more than 16 384 types declared in an interchanged script. + +#### 8.1.2.1 sequence types + +**Sequence** types shall be defined by: + +- their size (optional); +- their element type. + +The size shall be an unsigned short value. It represents the maximum number of elements of the sequence. If the type definition specifies no size, the number of elements may be any size up to the maximum. **Sequence** types with an explicit size are called bounded **sequence** types. + +The maximum size of any **sequence** type is 65 535 elements. + +The element type may be any primitive, constructed or predefined type except **void** and **object reference**. The element type shall be referenced using its type identifier. **Sequence** type definitions shall not lead to infinite recursion. + +NOTE – As a consequence, the type identifier of the **sequence** may be nested within the type definition only below a **union** constructor. + +Data whose type is a defined **sequence** type shall take as their value an ordered list of zero or more values of the element type. + +Variables of a **sequence** type without explicit initial value shall be initialized to a null list (sequence of zero element). + +#### 8.1.2.2 string types + +**String** types are semantically equivalent to **sequence** types whose element type is **character**. + +NOTE – To optimize their handling, string values may be implemented in a different way than sequences of character would. Therefore, strings and sequences of character remain distinct, although semantically equivalent, types. + +**String** types shall be defined by their size (optional). + +The size shall be an unsigned short value. It represents the maximum number of elements of the string. If the type definition specifies no size, the number of elements may be any size up to the maximum. **String** types with an explicit size are called bounded **string** types. + +The maximum size of any **string** type is 65 535 characters. + +Data whose type is a defined **string** type shall take as their value a string of zero or more characters. + +Variables of a **string** type without explicit initial value shall be initialized to a null string (sequence of zero character). + +#### 8.1.2.3 array types + +**Array** types shall be defined by: + +- their size; +- their element type. + +The size shall be an unsigned short value. It represents the exact number of elements in the array. + +The element type may be any primitive, constructed or predefined type except **void** and **object reference**. The element type shall be referenced using its type identifier. **Array** type definitions shall not lead to infinite recursion. + +NOTE – As a consequence, the type identifier of the **array** may be nested within the type definition only below a **union** constructor. + +Data whose type is a defined **array** type shall take as their value an ordered list of values of the element type, the length of the list being specified by the size of the array. + +Variables of an **array** type without explicit initial value shall be initialized to a list of elements whose initial value is determined by the element type. + +#### 8.1.2.4 structure types + +**Structure** types shall be defined by an ordered list of 1 to 256 element types. + +The element types may be any primitive, constructed or predefined type except **void** and **object reference**. The element types shall be referenced using their type identifiers. **Structure** type definitions shall not lead to infinite recursion. + +NOTE – As a consequence, the type identifier of the **structure** may be nested within the type definition only below a **union** constructor. + +Data whose type is a defined **structure** type shall take as their value an ordered list of values of the element type that corresponds to their rank in the type definition. + +Variables of a **structure** type without explicit initial value shall be initialized to a list of elements whose initial value is determined by their element type. + +### 8.1.2.5 union types + +**Union** types shall be defined by an ordered list of element types. + +There shall not be more than 256 choices (element types) in a **union** type. + +The element types may be any primitive, constructed or predefined type except **void** and **object reference**. The element types shall be referenced using their type identifiers. + +Data whose type is a defined **union** type shall take as their value: + +- an integer which represents the index (starting at 0) in the choice list; +- a value of the element type whose rank in the type definition is the above index. + +Variables of a **union** type without explicit initial value shall have an undefined initial value. + +## 8.2 Data + +The MHEG-SIR defines three kinds of data: + +- immediate values (see 8.2.1); +- constants (see 8.2.2); +- variables (see 8.2.3). + +All data used by an interchanged script are of a definite data type, either predefined or declared. + +Two data values shall be equal if and only if: + +- they are of the same type, i.e. they have the same type identifier; +- if they are of a primitive type then they are identical; +- if they are of a **structure**, **sequence** or **array** type then every element of one list is equal to the element of the same rank in the other list; +- if they are of a **union** type then their tags are identical and their values are equal to each other. + +As a consequence, + +- values of a **string** type shall not be compared with values of a **sequence** of **character** type; +- values of a bounded **sequence** type shall not be compared with values of another bounded **sequence** type or with values of an unbounded **sequence** type, since they have different type identifiers; +- values of a bounded **string** type shall not be compared with values of another bounded **string** type or with values of an unbounded **string** type, since they have different type identifiers. + +All variables and constants are referenced in a unique, unambiguous way by their data identifier. + +### 8.2.1 Immediate values + +Immediate values are data that are not declared within the interchanged script, and may therefore only be used "immediately", i.e. as they are encountered. An immediate value may be encountered in an interchanged script: + +- as a constant value; +- as the initial value of a variable; +- as the operand of a **push immediate (PUSHI)** instruction. + +Besides, immediate values are used in the course of the script execution through the parameter stack, as parameters for instructions or functions. + +Unless the context restricts it otherwise, immediate values may be of any type except **void**. + +The encoding of data values in an interchanged script is defined by Annex A. This Recommendation imposes no requirement on the way MHEG-3 engines represent data values of a particular type. + +### 8.2.2 Constants + +Constants shall be declared within the interchanged script and defined by: + +- a data type; +- a value of this data type. + +Constants may be of any type except: + +- **object reference**; +- **data identifier**; +- **void**. + +Constants have a global scope and may be referenced using their data identifier throughout the interchanged script. + +There shall not be more than 4096 constants declared in an interchanged script. + +### 8.2.3 Variables + +Variables shall be declared within the interchanged script and defined by: + +- a data type; +- optionally, a value of this data type, to be taken as the initial value for this constant. + +Variables may be of any type except **void**. + +Variables are referenced using their data identifier. A reference to a variable may be used with either of the following semantics: + +- "right-hand" semantics: the same as if the value of this variable was provided instead; +- "left-hand" semantics: states that this variable has to be assigned a data value. + +In the latter case, the value to be assigned to the variable may be an immediate value (including a computed value), the value of a constant or the value of a variable (including the future value of a function's output parameter). + +The MHEG-SIR defines three kinds of variables: + +- global variables (see 8.2.3.1); +- local variables (see 8.2.3.2); +- dynamic variables (see 8.2.3.3). + +#### 8.2.3.1 Global variables + +Global variables have a global scope which covers the entire interchanged script. They may be referenced using their data identifier from any routine or variable. They may be assigned a new value at any time during execution of the rt-script. + +There shall not be more than 28 672 global variables declared in an interchanged script. + +#### 8.2.3.2 Local variables + +Local variables have a lexical scope which is restricted to the execution of the code of the routine to which they belong. They may be referenced using their data identifier only within the code of this routine. + +There are two kinds of local variables: + +- local variables that are declared within the routine declaration as part of the local variable declaration; +- actual parameters of the routine, whether passed by value or by reference, which are declared within the routine declaration as part of the routine signature. + +There shall not be more than 256 local variables declared in each routine of an interchanged script. + +### 8.2.3.3 Dynamic variables + +Dynamic variables have a dynamic scope which extends from the time when they are created using an **allocate** (**ALLOC**) instruction up to the time when they are released using a **free** (**FREE**) instruction. At creation, they are given a data identifier by the script interpreter. They may be referenced using their data identifier at any time during the execution of the script. However, as the data identifier of a dynamic variable is only known at run-time, it can only be used as a parameter stack or a variable value, not as the operand of an instruction. + +There shall not be more than 32 512 dynamic variables used at a given time during execution of an rt-script. + +## 8.3 Functions + +The MHEG-SIR defines three kinds of functions: + +- routines (see 8.3.1); +- services (see 8.3.2); +- predefined functions (see 8.3.3). + +All functions shall have a signature (or prototype) which consists of: + +- a type of return value; +- an ordered list of formal parameters defined by their type and passing mode. + +All functions are referenced in a unique, unambiguous way using their function identifier. + +Functions shall be either **synchronous** or **asynchronous**. When a synchronous function is called, the caller waits for the completion of the function execution and may therefore retrieve its result. When an asynchronous function is called, the caller only waits for an acknowledgement of reception of the request; it then resumes execution without waiting for the completion of the function. + +As a consequence, asynchronous functions shall not have output parameters or a return value. Routines are always synchronous. + +### 8.3.1 Routines + +Routines are internal functions of interchanged scripts. + +Routines shall be declared within the interchanged script. Routines shall consist of: + +- a signature; +- local variables; +- program code. + +There shall not be more than 4096 routines declared in an interchanged script. + +Execution of a routine may be triggered: + +- by an explicit **call** (**CALL**) instruction, with the routine's function identifier being the operand of the instruction; + +- upon reception of an exception during an **external call (XCALL)** instruction, where the message identifier of the received exception is mapped to the routine's function identifier by the handler definition table; +- upon examining the queue of received messages, either when no routine is executing or upon encountering a **yield (YIELD)** instruction, where the message identifier of the received message is mapped to the routine's function identifier by the handler definition table or is an MHEG-3 API **run** operation targeted at the routine. + +Parameters may be passed to routines using either of the following modes: + +- by **value**: a value of the parameter type is passed to the routine; +- by **reference**: a data identifier referencing a global variable, dynamic variable or constant whose type is the same as the parameter type is passed to the routine. + +In both cases, the value of the passed parameter becomes the value of the local variable whose index corresponds to the parameter's index. The local variable corresponding to a parameter passed by reference shall be of the **data identifier** type. + +Data identifiers to local variables shall not be passed by reference. + +### 8.3.2 Services + +Services are external functions provided by the run-time environment that an interchanged script may invoke. + +Services shall be declared within the interchanged script, as part of a package declaration, by: + +- their signature; +- their IDL global operation name. + +There shall not be more than 256 services declared in each package of an interchanged script. + +There shall not be more than 192 packages declared in an interchanged script. + +A service may be called by an **external call (XCALL)** instruction. + +Parameters may be passed to services using one of the following modes: + +- **in**: a data identifier referencing a variable or constant whose type is the same as the parameter type is passed to the service; +- **inout**: a data identifier referencing a variable whose type is the same as the parameter type is passed to the service; upon returning, the variable is updated with its new value; +- **out**: same as **inout**, however the value of the variable is not used by the service. + +### 8.3.3 Predefined functions + +Predefined functions correspond to the operations of the MHEG-3 engine's interface. + +Predefined functions have predefined function identifiers and therefore shall not be declared within an interchanged script. + +As this Recommendation is not specifically linked to one of the ITU-T Recommendations of the T.170-Series (and parts of ISO/IEC 13522), the MHEG API operations used to manipulate MHEG objects are not explicitly defined. However, this Recommendation specifies the procedure that shall be used to define an MHEG API and to specify the mapping of operations of this MHEG API to predefined function identifiers. This is described in Annex E. + +In addition, this Recommendation defines the MHEG-3 API, i.e. the interface that MHEG-3 engines shall provide for the manipulation of scripts. This interface is described in clause 15 and Annex F. + +This interface may be used from within scripts and is therefore mapped to predefined function identifiers. The list of these predefined functions and their identifiers is given in Annex C. + +Predefined functions may be called and passed parameters to using the same mechanisms as with services. + +## 8.4 Messages + +The MHEG-SIR defines two kinds of messages: + +- package exceptions (see 8.4.1); +- predefined messages (see 8.4.2). + +All messages shall have a signature (or prototype) which consists of an ordered list of formal parameters (members) defined by their type. + +All messages are referenced in a unique, unambiguous way by their message identifier. + +### 8.4.1 Package exceptions + +Package exceptions are sent to an rt-script by the run-time environment as a consequence of the invocation of a service by this rt-script. + +Package exceptions shall be declared within the interchanged script, as part of a package declaration, by: + +- their signature; +- their IDL global exception name. + +There shall not be more than 256 exceptions declared in each package of an interchanged script. + +### 8.4.2 Predefined messages + +Predefined messages sent to an rt-script may be one of the following: + +- an exception of the MHEG-3 engine interface (i.e. the MHEG API), raised by the MHEG-3 engine as a consequence of the invocation of a predefined function by the rt-script; +- the consequence of invocation of an operation of the MHEG-3 API targeted at the rt-script; +- the **InstructionExecutionError** exception, which is raised as the consequence of an error occurring in the execution of an instruction of the rt-script. + +Predefined messages have predefined message identifiers and therefore shall not be declared within an interchanged script. + +As this Recommendation is not specifically linked to one of the ITU-T Recommendations of the T.170-Series (and parts of ISO/IEC 13522), the MHEG API exceptions are not explicitly defined. However, this Recommendation specifies the procedure that shall be used to define an MHEG API and to specify the mapping of exceptions of this MHEG API to predefined message identifiers. This is described in Annex E. + +Annex C specifies how the **InstructionExecutionError** and the messages resulting from MHEG-3 API operations shall be mapped to predefined message identifiers. + +## 8.5 Instructions + +The program code part of routines consists of a sequence of instructions. Unlike the rest of an interchanged script, which is handled upon preparation of the script, instructions need only be dealt with after creation of an rt-script, when the routine to which they belong is activated. + +An instruction shall consist of one op-code (operation code) followed by zero or more operands. The number, type and encoding of operands is fully determined by the op-code. + +As a rule, operands complete the instruction, whereas parameter values are taken from the parameter stack. + +The performance of the instruction execution unit is described in clause 9, whereas the precise semantics of each instruction are described in clause 13. + +## **8.6 Identifiers** + +Identifiers are used to reference MHEG-SIR entities (i.e. types, data, functions and messages) in an unambiguous way, throughout interchanged scripts. + +### **8.6.1 Type identifiers** + +Type Identifiers (TIDs) shall be encoded on two bytes as follows: + +- primitive types and predefined types shall have predefined TIDs as defined by Annex C; +- declared types whose index (starting at 0) in the type declaration table is X shall have (X + 4000h) as TID. + +Hence: + +- TIDs between 0 and 3FFFh shall reference predefined types; +- TIDs between 4000h and 7FFFh shall reference declared types. + +### **8.6.2 Data identifiers** + +Data Identifiers (DIDs) shall be encoded on two bytes as follows: + +- constants whose index (starting at 0) in the constant declaration table is X shall have X as DID; +- global variables whose index (starting at 0) in the global variable declaration table is X shall have (X + 1000h) as DID; +- local variables whose index (starting at 0) in the local variable declaration table is X shall have (X + 8000h) as DID; +- dynamic variables shall have DIDs starting at 8100h. The procedure for allocating data identifiers to dynamic variables is not specified; MHEG-3 engines may therefore have different allocation schemes. + +Hence: + +- DIDs between 0 and 0FFFh shall reference constants; +- DIDs between 1000h and 7FFFh shall reference global variables; +- DIDs between 8000h and 80FFh shall reference local variables; +- DIDs between 8100h and FFFFh shall reference dynamic variables. + +### **8.6.3 Function identifiers** + +Function Identifiers (FIDs) shall be encoded on two bytes as follows: + +- routines whose index (starting at 0) in the routine declaration table is X shall have X as FID; +- predefined functions whose index (starting at 0) in the predefined function table is X shall have (X + 1000h) as FID; +- services whose index (starting at 0) in a package declaration is X and whose package index in the package declaration table is Y (starting at 0) shall have $((Y + 64) \ll 8) + X$ as FID. + +Hence: + +- FIDs between 0 and 0FFFh shall reference routines; +- FIDs between 1000h and 3FFFh shall reference predefined functions; +- FIDs between 4000h and FFFFh shall reference services. + +#### **8.6.4 Message identifiers** + +Message Identifiers (MIDs) shall be encoded on two bytes as follows: + +- predefined messages whose index (starting at 0) in the predefined message table is X shall have X as MID; +- exceptions whose index (starting at 0) in a package declaration table is X and whose package index (starting at 0) in the package declaration table is Y shall have $((Y + 64) \ll 8) + X$ as MID. + +Hence: + +- MIDs between 0 and 3FFFh shall reference predefined messages; +- MIDs between 4000h and FFFFh shall reference package exceptions. + +### **9 The MHEG-SIR virtual machine** + +This clause presents the MHEG-SIR virtual machine, i.e. the execution model for the MHEG-SIR code. + +#### **9.1 Structure of the MHEG-SIR virtual machine** + +The MHEG-SIR virtual machine is a set of logical, abstract components. The description of the MHEG-SIR virtual machine is intended for clarification of the operational semantics of the MHEG-SIR code. + +An MHEG-3 engine shall have the same interpretation behaviour for MHEG-SIR code as the described virtual machine. It shall interpret MHEG-SIR declarations and instructions so as to produce similar external effects in all respects. + +However, this implies no requirements on the technology or organization that may actually be used to implement an MHEG-3 engine. An actual script interpreter need not be designed as described by the virtual machine, as long as it provides equivalent functionality. + +The MHEG-SIR virtual machine consists of: + +- memory areas (see 9.3); +- processing units (see 9.5). + +Some memory areas are associated with an mh-script and so shared by all the rt-scripts created from it. Other memory areas are associated with each rt-script. + +Processing units only apply to one rt-script. However, an MHEG-3 engine may run several rt-scripts at the same time. In this case, it shall maintain a separate run-time context for each active rt-script. + +NOTE – In other terms, the MHEG-SIR virtual machine is single-threaded. Multi-threaded applications can be achieved by associating each thread with a separate rt-script. + +## 9.2 Structures and notations + +### 9.2.1 Table + +A table **T** consists of an array of homogeneous entries **T[i]** that may be accessed via their index **i**. These entries have the same structure, but not necessarily the same size. Entries consist of one or several fields **fld**. Some entries may be void. Indices are MHEG-SIR identifiers, i.e. consecutive numeric values taken in a given range, not necessarily starting at 0 for a given table. The underlying access mechanism (sequential indexing, direct access, hashcoding, etc.) is not specified. The notation uses the following primitives to express manipulation of a table **T**: + +- **T[i]** to access entry **i**; +- **T[i] = VAL** to assign value **VAL** to entry **i**; +- **T[i].fld** to access field **fld** of entry **i**; +- **T[i].fld = VAL** to assign value **VAL** to field **fld** of entry **i**. + +### 9.2.2 Stack + +A stack consists of an array of homogeneous elements. Elements are inserted on the top of the stack. Only the top element (last inserted) may be accessed at any time. When it is removed from the stack, it is lost, and the next element becomes the top of the stack. The notation uses the following primitives to express manipulation of the call stack **CS**: + +- **CS.push(F)**: inserts frame **F** on the top of the stack, increments the frame pointer register (**FP**); +- **CS.pop()**: decrements **FP**, removes the top-of-stack frame, then returns it; +- **CS[FP]**: returns the value of the top-of-stack frame. + +In the same way as for tables, the "." notation is used to access stack element fields. + +### 9.2.3 Parameter stack + +The parameter stack is a special case because it is a byte (untyped) stack used to store typed values. The notation uses the following primitives to express manipulation of the parameter stack **PS**, where **tid** is the type identifier of a primitive type, as indicated by Table 1: + +- **PS.push(VAL)**: inserts value **VAL** on the top of the stack; +- **PS.pop(tid)**: removes the top-of-stack value, whose type identifier is **tid**, then returns it; +- **PS[SP](tid)**: returns the value of the top-of-stack value, whose type identifier is **tid**. + +### 9.2.4 Queue + +A queue consists of an array of homogeneous elements. Elements are inserted at the end of the queue. Only the start element (first inserted) may be accessed at any time. When it is removed from the queue, it is lost, and the next element becomes the start of the queue. The notation uses the following primitives to express manipulation of the message queue **MQ**: + +- **MQ.insert(M)**: inserts message value **M** at the end of the queue; +- **MQ.remove()**: increments the Queue Pointer (**QP**) register, removes the element at the start of the queue, and returns it; +- **MQ[QP]**: returns the value of the element at the start of the queue. + +In the same way as for tables, the "." notation is used to access queue element fields. + +### 9.2.5 Data representation + +The representation of the structures and data is implementation-dependent. Although script interpreters may represent each value of a data type with a minimum number of bytes, they are not required to do so. Table 2 states this minimum number: + +**Table 2/T.173 – Minimum number of bytes to represent values** + +| Type | Minimum number of bytes to represent a value of the type | +|---------------------|------------------------------------------------------------------------| +| octet | 1 | +| short | 2 | +| long | 4 | +| unsigned short | 2 | +| unsigned long | 4 | +| float | 4 | +| double | 8 | +| boolean | 1 | +| character | 2 (1 for restricted character sets) | +| data identifier | 2 | +| object reference | Implementation-dependent | +| string | Character size x (string length + 1) | +| sequence | Size of element type x sequence length (actual number of elements) + 2 | +| array | Size of element type x array size | +| structure | Sum of the sizes of the element types | +| union | Size of the "biggest" element type + 1 | +| type identifier | 2 | +| function identifier | 2 | +| message identifier | 2 | +| package identifier | 1 | + +NOTE – The notation makes no distinction between fixed-length values and variable-length values. Script interpreters may store variable-length values on the heap. `VT[i].val` is used to access the value of a variable even though it could actually be stored in the variable table as a handle to the heap. + +When `VAL` is a value of a constructed type, access to its elements is noted as follows: + +- `VAL.tag`: tag of a union; +- `VAL.val`: value of a union; +- `VAL[n]`: value of the nth element of a sequence, string, structure or array; +- `VAL.lg`: actual length of a sequence or string. + +Execution semantics are expressed using a C-like syntax. Expressions within single quotes indicate the corresponding value, e.g. "void" indicates TID value 0. + +### 9.3 Memory areas + +In the MHEG-SIR virtual machine, memory areas are used to hold all the necessary information used to interpret a particular interchanged script. + +Memory areas may be associated with either an mh-script (see 9.3.1) or an rt-script (see 9.3.2). + +#### 9.3.1 Mh-script memory areas + +Mh-script memory areas should be completely filled at load-time, i.e. upon initialization of an mh-script. They shall be accessible for use by all rt-scripts created from this mh-script. Mh-script memory areas shall not be modified at run-time until the mh-script is destroyed, unless otherwise specified (e.g. for the package definition table). Mh-script memory areas comprise: + +- data areas (see 9.3.1.1); +- code areas (see 9.3.1.2). + +##### 9.3.1.1 Data areas + +Data areas are used to store the definitions and values of the script's global data. Data areas comprise: + +- the Type definition Table (TT) (see 9.3.1.1.1); +- the Constant Table (CT) (see 9.3.1.1.2); +- the Global variable definition Table (GT) (see 9.3.1.1.3). + +##### 9.3.1.1.1 Type definition table + +The type definition table maps all the script's defined types, represented by type identifiers, to their description: + +- **TT[TID].val**: description of the type. + +NOTE – The representation used for the type description is not specified; however, it should allow to check easily whether a value belongs to a type. + +##### 9.3.1.1.2 Constant table + +The constant table maps all the script's constants, represented by data identifiers, to their type and value: + +- **CT[DID].TID**: type of the constant (expressed as a type identifier); +- **CT[DID].val**: value of the constant (depending on its type). + +##### 9.3.1.1.3 Global variable definition table + +The global variable definition table maps all the script's global variables, represented by data identifiers, to their type and initial value: + +- **GT[DID].TID**: type of the global variable (expressed as a type identifier); +- **GT[DID].val**: initial value of the global variable (depending on its type). + +#### 9.3.1.2 Code areas + +Code areas are used to store the addresses and program code of the script's functions. Code areas comprise: + +- the Routine definition Table (RT) (see 9.3.1.2.1); +- the Package definition Table (PT) (see 9.3.1.2.2); +- the Service definition Table (ST) (see 9.3.1.2.3); +- the eXception definition Table (XT) (see 9.3.1.2.4); + +- the Handler definition Table (HT) (see 9.3.1.2.5); +- the program code area, consisting of the sequence of instructions of each routine (see 9.3.1.2.6). + +#### 9.3.1.2.1 Routine definition table + +The routine definition table maps all the script's routines, represented by function identifiers, to their signature description, their local variable declaration and their program code: + +- a) **RT[FID].TID**: type of return value (expressed as a type identifier); +- b) **RT[FID].nbp**: number of parameters; +- c) **RT[FID].sig**: signature description, where: + - 1) **RT[FID].sig[i].TID** is the type (expressed as a type identifier) of the *i*th parameter; + - 2) **RT[FID].sig[i].mod** is the passing mode (**value** or **reference**) of the *i*th parameter; +- d) **RT[FID].LT**: declaration of the routine's local variables (whose **nbp** first elements are the actual parameters of the routine); +- e) **RT[FID].IP**: pointer to the first instruction in the routine code. + +Local variables used to hold parameters passed by **reference** shall have **data identifier** as their type, while local variable used to hold parameters passed by **value** shall have the same type as in the signature description for the corresponding parameter. + +#### 9.3.1.2.2 Package definition table + +The package definition table maps all the script's defined packages, represented by Package Identifiers (PIDs) as declared by the MHEG-SIR package declaration table, to package names and additional information: + +- **PT[PID].name**: name of the package; +- **PT[PID].nbf**: number of services in the package; +- **PT[PID].nbm**: number of exceptions defined by the package; +- **PT[PID].sts**: current status of the package (**unchecked**, **available**, **ready**, **opened**); +- **PT[PID].or**: initial object reference of the package. + +A package is initially at **unchecked** status. It becomes **available** once the **package availability** procedure has been performed successfully. It then becomes **ready** once the **package load** procedure has been performed successfully. Finally, it is **opened** when there is a valid initial object reference to the package, stored in the **PT[PID].or** field, for use by further service invocations. + +As an exception to the rule stated in 9.3.1, + +- The **PT[PID].sts** fields may be modified at run-time, each time the status of a package changes. +- The **PT[PID].or** fields may be modified at run-time, when a package is loaded. + +#### 9.3.1.2.3 Service definition table + +The service definition table maps all the script's defined external services, represented by MHEG-SIR function identifiers, to their signature description and to their IDL global operation name: + +- a) **ST[FID].TID**: type of return value (expressed as a type identifier); +- b) **ST[FID].syn**: calling mode (**synchronous**, **asynchronous**); +- c) **ST[FID].nbp**: number of parameters; + +- d) **ST[FID].sig**: signature description, where: + - 1) **ST[FID].sig[i].TID** is the type (expressed as a type identifier) of the *i*th parameter; + - 2) **ST[FID].sig[i].mod** is the passing mode (**in**, **inout** or **out**) of the *i*th parameter; +- e) **ST[FID].name**: the IDL global name of the operation which the service invokes. + +The IDL platform-specific mapping specification shall be used to map **ST[MID].name** to a platform-specific name. + +#### 9.3.1.2.4 Exception definition table + +The exception definition table maps all the interchanged script's defined messages, represented by message identifiers, to their signature description and their IDL global exception name: + +- **XT[MID].name**: the IDL global name of the exception which causes the message; +- **XT[MID].nbm**: number of members; +- **XT[MID].sig**: signature description, where **XT[MID].sig[i].TID** is the type (expressed as a type identifier) of the *i*th member. + +The IDL platform-specific mapping specification is used to map **XT[MID].name** to a platform-specific name. + +#### 9.3.1.2.5 Handler definition table + +The handler definition table maps messages, represented by message identifiers, to routines represented by function identifiers: + +- **HT[MID].FID**: identifier of routine to invoke for handling the message. + +If a message is mapped to a routine in the handler table, the signature of this routine needs to match the signature of this message. Matching between the signatures shall be checked at load-time and non-matching entries shall be rejected. + +The handler definition table is used by the rt-script execution unit. When the rt-script execution unit removes a message from the message queue, it invokes the routine that corresponds to the message, with the message parameters as its parameters. + +#### 9.3.1.2.6 Program code area + +An instruction consists of one 1-byte op-code followed by zero to three operand bytes. The op-code completely determines the number and length of its operands, according to the instructions table. Both op-codes and operands are coded in an optimized fashion so as to ease switching. + +NOTE – A script interpreter (especially on 32-bit machines) may align instructions at load-time, i.e. insert padding bytes in order to represent each instruction on four bytes; this makes it easy to increment the instruction pointer. As a variant, a script interpreter may instead leave instructions packed, and determine the number of bytes to increment at run-time. + +### 9.3.2 Rt-script memory areas + +Rt-script memory areas are initialized upon creation of the rt-script and may be modified during its execution. Rt-script memory areas comprise: + +- dynamic memory areas (see 9.3.2.1); +- registers (see 9.3.2.2). + +#### 9.3.2.1 Dynamic memory areas + +Dynamic memory areas are used to represent the data and the current execution context of the rt-script. + +Dynamic memory areas comprise: + +- the Variable Table (VT) (see 9.3.2.1.1); +- the Call Stack (CS) (see 9.3.2.1.2); +- the Parameter Stack (PS) (see 9.3.2.1.3); +- the Message Queue (MQ) (see 9.3.2.1.4); +- the heap (see 9.3.2.1.5). + +#### 9.3.2.1.1 Variable table + +The variable table maps the rt-script's variables, represented by data identifiers, to their type and current value: + +- **VT[*DID*].TID**: type of the variable (expressed as a type identifier); +- **VT[*DID*].val**: current value of the variable (depending on its type). + +The variable table is initialized upon creation of the rt-script. It consists of two subtables: + +- a copy of the global variable table associated with the mh-script; +- the local variable table of the currently executing routine. + +**VT[*DID*].val** fields are modified every time a variable is assigned by the execution of a variable assignment instruction. + +When the current routine changes (following execution of a **CALL**, **RET** or **YIELD** instruction), the local variable table is stored and replaced in the VT by the local variable table of the new routine. The first entries of a local variable table are the parameters passed to the function. + +#### 9.3.2.1.2 Call stack + +The call stack is used to store the current invocation context. + +The call stack is an array of call frames. Every frame shall correspond to the context at the time of invocation of an active function (routine, external function or MHEG action). Frames shall be stored on the CS in order of invocation. The top frame of the CS, if any, shall describe the execution context of the routine that called the currently executing function. + +Each frame shall consist of the following elements: + +- **CS[*i*].FID**: function identifier of the caller; +- **CS[*i*].IP**: pointer to the instruction to return to after the current function returns; +- **CS[*i*].LT**: local variable table of the caller (at invocation time); +- **CS[*i*].SP**: pointer to the top of the parameter stack (at invocation time). + +The LT field of a call frame shall have the structure of a variable table: + +- **CS[*i*].LT[*DID*].TID**: type identifier of the variable whose identifier is **DID**; +- **CS[*i*].LT[*DID*].val**: value of the variable. + +The call stack is modified by certain control flow instructions. Initially the call stack shall be empty. When a function is invoked, a frame describing this call shall be pushed onto the call stack. When a function is returned from, this frame shall be popped from the call stack. The address of the top frame of the call stack shall be stored at all times in the FP register. + +### 9.3.2.1.3 Parameter stack + +The parameter stack is used to store the parameters and return values of instructions. The parameter stack is an array of data values. The type of the data value is determined by the operation sequence that pushes the value on the stack. + +The parameter stack is used by the MHEG-SIR instruction execution unit. Initially the parameter stack shall be empty. It is modified by most instructions (arithmetic operators, logical operators, comparison operations, stack manipulation, variable assignment, conditional jumps, calls). When an instruction is executed, it shall pop its parameters from the parameter stack and push its return value back onto the parameter stack. The address of the top frame of the parameter stack shall be stored at all times in the Stack Pointer (SP) register. + +### 9.3.2.1.4 Message queue + +The message queue is used to buffer the messages that are received by the script interpreter. Each item in the queue shall consist of the following elements: + +- **MQ[i].MID**: message identifier; +- **MQ[i].LT**: list of message parameters. + +The LT field of a message queue item shall have the structure of a variable table: + +- **MQ[i].LT[j].TID**: type identifier of the jth parameter; +- **MQ[i].LT[j].val**: value of the jth parameter. + +Messages shall be inserted into the message queue by the script interpreter asynchronously as they are generated in the external environment. The message queue shall be processed by the rt-script execution unit when either of the following occurs: + +- the rt-script is not running, i.e. there is no currently executing routine; +- a **YIELD** instruction is encountered. + +The start of the message queue (next message to pop) shall be stored at all times in the QP (Queue Pointer) register. Initially the message queue shall be empty. + +### 9.3.2.1.5 Heap + +The heap is used to store dynamic variables, represented by data identifiers, as their type and current value: + +- **VT[DID].TID**: type of the variable (expressed as a type identifier); +- **VT[DID].val**: current value of the variable (depending on its type). + +Dynamic variables are referenced by handles of an opaque type, whose representation is not specified. Data identifiers are internally mapped to these handles so that dynamic variables be accessed in the same way as other variables. + +**VT[DID].val** fields are modified every time a variable is assigned by the execution of a variable assignment instruction. + +The application is responsible for explicit allocation and de-allocation of dynamic variables using the **ALLOC** and **FREE** instructions. + +NOTE – Script interpreters may also use the heap to store the values of global or local variables of a variable-length type. In this case, a heap handle is stored in the table instead of the data itself. + +### 9.3.2.2 Registers + +Registers hold specific states of the virtual machine and need to be frequently modified during the execution of an rt-script. + +The registers maintained by the MHEG-SIR virtual machine are: + +- the Instruction Pointer (IP) or program counter (see 9.3.2.2.1); +- the Frame Pointer (FP) (see 9.3.2.2.5); +- the Stack Pointer (SP) (see 9.3.2.2.4); +- the Queue Pointer (QP) (see 9.3.2.2.6); +- the Instruction Register (IR) (see 9.3.2.2.2); +- the Error Register (ER) (see 9.3.2.2.3); +- the Function Register (FR) (see 9.3.2.2.7). + +The representation of data held by pointer registers is not specified. All registers shall be initialized to a null value whose representation is not specified. + +#### 9.3.2.2.1 Instruction pointer register + +The IP register points to the next instruction to be executed within a routine's program code. This register shall be modified by the rt-script execution unit and by the MHEG-SIR instruction execution unit as part of the execution of instructions. + +#### 9.3.2.2.2 Instruction register + +The IR register holds the code for the instruction which is currently executing. This register shall be updated by the rt-script execution unit each time a new instruction is loaded, and accessed by the MHEG-SIR instruction execution unit. + +NOTE – The IR need not be more than 4 bytes long, but its actual size is not specified. + +#### 9.3.2.2.3 Error register + +The ER holds the code of the last error encountered during execution of an instruction. This register shall be updated by the MHEG-SIR instruction execution unit, every time it encounters an error. The null value indicates that up to the current time no error has been encountered during the execution of the rt-script. + +The error codes are predefined. The error codes raised by each instruction are defined in clause 13. + +When an error is raised during execution of an instruction, ER shall be set to a non-null value and an **InstructionExecutionError** exception shall be raised. This results in the corresponding message being inserted into the message queue. + +#### 9.3.2.2.4 Stack pointer register + +The SP register points to the top of the parameter stack. The value of this register shall be updated by the MHEG-SIR instruction execution unit as follows: + +- it shall be incremented every time data is pushed onto the parameter stack; +- it shall be decremented every time data is popped off the parameter stack. + +#### 9.3.2.2.5 Frame pointer register + +The FP register points to the top frame of the call stack. The value of this register shall be updated by the MHEG-SIR instruction execution unit as follows: + +- it shall be incremented every time a function is called; + +- it shall be decremented every time a function is returned from. + +#### 9.3.2.2.6 Queue pointer register + +The QP register points to the next message to be removed from the message queue. The value of this register shall be decremented by the script interpreter every time a message is removed. + +#### 9.3.2.2.7 Function register + +The FR register holds the FID of the currently executing function. The value of this register shall be updated by the script interpreter every time a function is called or returned from. + +### 9.4 Script statuses + +#### 9.4.1 Mh-script statuses + +The status of an mh-script shall be either **available** or **not available**. + +##### 9.4.1.1 Not available + +The status of an mh-script shall be **not available** if it is in one of the following cases: + +- mh-script initialization (i.e. the effect of the MHEG-3 API **prepare** operation) has not been achieved on this mh-script; +- mh-script destruction (i.e. the effect of the MHEG-3 API **destroy** operation) has been requested on this mh-script. + +##### 9.4.1.2 Available + +The status of an mh-script shall be **available** if mh-script initialization has been successfully achieved on this mh-script and if mh-script destruction has not yet been requested. + +This implies that: + +- the interchanged script has been parsed and the mh-script memory areas fully completed accordingly; +- the packages referenced in the mh-script are available and have been loaded according to the **package load** procedure. + +#### 9.4.2 Rt-script statuses + +The status of an rt-script shall be one of the following: **not ready**, **ready**, **running**, **erroneous**. + +##### 9.4.2.1 Not ready + +The status of an rt-script shall be **not ready** if it is in one of the following cases: + +- rt-script initialization (i.e. the effect of the MHEG-3 API **new** operation) has not been achieved on this rt-script; +- rt-script destruction (i.e. the effect of the MHEG-3 API **delete** operation) has been requested on this rt-script. + +The status of an rt-script is initially **not ready**. Otherwise, it changes to **not ready** when a **delete** operation is invoked on this rt-script. + +##### 9.4.2.2 Ready + +The status of an rt-script shall be **ready** if all of the following conditions are met: + +- rt-script initialization has been successfully achieved on this mh-script; + +- rt-script destruction has not yet been requested on this rt-script; +- the IP register is set to "null", i.e. there is no currently executing routine; +- the ER register is set to "null". + +This implies that the calling stack, message queue and parameter stack are void. + +However, the global variable values need not be the same as the initial values; once it has no more instruction to execute and no message in the message queue, an rt-script goes back to **ready** status. + +The status of an rt-script changes: + +- from **not ready** to **ready** when a **new** operation is invoked on this rt-script; +- from **running** to **ready** when the rt-script execution unit no longer has instructions to execute or as the result of invoking a **stop** or **reinit** operation; +- from **erroneous** to **ready** as the result of invoking a **stop** or **reinit** operation. + +#### 9.4.2.3 Running + +The status of an rt-script shall be **running** if all of the following conditions are met: + +- rt-script initialization has been achieved without error on this mh-script; +- rt-script destruction has not yet been requested on this rt-script; +- the IP register is not "null", i.e. there is a currently executing routine; +- the ER register is set to "null". + +The status of an rt-script changes from **ready** to **running** when there is a message in the message queue and the rt-script execution unit is activated. This may occur as the result of invoking a **run** operation. + +#### 9.4.2.4 Erroneous + +The status of an rt-script shall be **erroneous** if the ER register is not "null", i.e. if an error has occurred during the rt-script execution. + +The status of an rt-script changes from **running** to **erroneous** when an instruction execution error is raised by the rt-script instruction execution unit. + +### 9.5 Processing units + +This subclause describes the MHEG-SIR virtual machine's flow of control and the semantics of instructions. + +For the purposes of the virtual machine description, the script interpreter's main process is assumed to run in parallel with all active rt-script execution units. Scheduling of the different tasks is not specified. + +#### 9.5.1 Message reception + +The script interpreter's main process receives and handles events. In the absence of any events, it is idle. Events received by the script interpreter may be: + +- MHEG-3 API operation invocations; +- messages corresponding to the occurrence of an exception raised as the result of invoking either a service or predefined function. + +### 9.5.1.1 MHEG-3 API operations + +MHEG-3 API operations may be invoked by an rt-script execution unit, by another component of the MHEG-3 engine or by external processes outside the MHEG-3 engine. + +When an MHEG-3 API operation is invoked, the main process shall proceed as specified by the semantics of the MHEG-3 API described in clause 15. + +### 9.5.1.2 External exception + +When a message coming from either the action interpreter (MHEG API exception) or the run-time environment is targeted at an rt-script, then if this message actually corresponds to an exception raised by the MHEG API or the run-time environment as a consequence of the invocation of an operation resulting from an **XCALL** instruction by this rt-script, the main process shall parse the exception's parameters and construct a message structure consisting of the message identifier of the exception followed by its actual members (starting with the object reference of the originating object). Then: + +- if the exception results from the invocation of a currently executing synchronous operation, the main process shall request the rt-script execution unit to terminate the **XCALL** instruction (therefore popping its frame from the call stack) without looking for output parameters or a return value, then immediately afterwards to trigger the routine corresponding to the exception's message identifier, with the exception's members as its actual parameters; the effect shall be the same as if this routine had been invoked by a **CALL** instruction; +- if the exception results from the invocation of a previously terminated synchronous operation (whether successfully or not), the main process shall ignore the exception; +- if the exception results from the invocation of an asynchronous operation, the main process shall insert the constructed message into the message queue of the target rt-script. + +### 9.5.1.3 InstructionExecutionError exception + +When the internal **InstructionExecutionError** exception is raised by the execution of an instruction, the main process shall construct a message structure consisting of the message identifier corresponding to this exception, followed by one member set to the value of the error register, then insert it into the message queue of the rt-script whose execution raised the exception. + +### 9.5.1.4 MHEG-3 API exception + +When an exception resulting from the invocation of an MHEG-3 API operation is returned to an rt-script, the main process shall construct a message structure consisting of the message identifier corresponding to the exception, followed by its members, then insert it into the message queue of the rt-script that invoked the operation. + +## 9.5.2 Mh-script initialization + +When the MHEG-3 API **prepare** operation is invoked, the script interpreter shall access the stream or file using the provided system identifier and parse the script. The script interpreter shall then: + +- parse the declarations part and initialize the CT, GT, TT, RT, ST, PT, XT, HT and the **RT[i].LT** for each routine *i*; this includes the appropriate checks (handler verification, **package availability** procedure); +- parse the structure of the instructions part to fill in the program code area of each routine; +- perform the **package load** procedure, establishing static links with packages according to the platform mapping specification; +- put the mh-script to **available** status. + +NOTE – The semantics of package loading need to be defined by the platform mapping specification. The MHEG-3 engine may take the responsibility to optimize its resource management strategy, e.g. by unloading packages temporarily in order to release memory, or by loading packages only as rt-scripts are created or even as services are invoked. + +### 9.5.3 Rt-script initialization + +When the MHEG-3 API **new** operation is invoked, the script interpreter shall create a context for the target rt-script, i.e. the script interpreter shall: + +- initialize the dynamic memory areas; +- initialize all registers to null values; +- create an rt-script execution unit for the rt-script; +- put the rt-script to **ready** status. + +### 9.5.4 Rt-script execution unit + +When activated and unless requested to stop the current rt-script, the rt-script execution unit shall perform as follows: + +``` +rt-script-execution-unit () +{ +FID fid = 'null'; +if (IP == 'null') // no next instruction +{ + while (fid == 'null') + { + if (QP == 'null') then exit; // return + fid= HT[MQ[QP].MID].FID; // find handler for message + if (fid != 'null') then // handler found + { + CS.push({IP, FR, SP, 'null'}); // stack routine call + FR = fid; + IP = RT[FR].IP; // branch to start of routine + } + MQ.remove(); // remove message + } +} +// endif + +while (IP != 'null'): +{ + IR = *IP++; // load next instruction and increment program counter + instruction-execution-unit(); // call the MHEG-SIR instruction execution unit +} +// endwhile +return; // return to script interpreter +} +``` + +### 9.5.5 MHEG-SIR instruction execution unit + +When called by the rt-script execution unit, the MHEG-SIR instruction execution unit of an rt-script shall decode the op-code contained in the first byte of the IR, then interpret the instruction corresponding to this op-code as specified by clause 13, then return. + +The instruction execution unit pops from the parameter stack those parameters that are used to perform the instruction (if any). It pushes on the parameter stack those parameters that are the result of the instruction (if any). + +Table 3 summarizes the effects of the instructions on the various elements of the MHEG-SIR virtual machine as defined by this clause. + +## **10 Provisions for run-time environment access** + +This clause describes the mechanisms defined by this Recommendation to make it possible for rt-scripts to access and interchange data with external functions provided by the run-time environment on the execution platform. + +### **10.1 General model** + +The interface that external software available in the run-time environment provides need to be declared in the interchanged script as part of its package declaration, so that the script interpreter knows how to access this interface when the script invokes it. + +A package declaration describes a set of services (i.e. external functions) by their signature, i.e. the type and passing mode of each parameter. + +MHEG-SIR specifies how calling external functions, passing parameters, getting back return values and handling exceptions shall be expressed within interchanged scripts. + +This Recommendation also specifies how these expressions shall be interpreted by MHEG-3 engines. + +This Recommendation also deals with interchange (i.e. function call, parameters passing, return value retrieval and exception handling) between an MHEG-3 engine and the run-time environment. For this purpose, this Recommendation contains provisions for specifying how access to these functions should be provided to MHEG-3 engines by external software. Such a convention, called a platform mapping specification, is dependent on the run-time platform. + +Platform mapping specifications conforming to the provisions of this Recommendation need to be registered to ensure the interoperability of run-time environment services with any compliant MHEG-3 engine on this platform. If a platform mapping specification exists for the platform, MHEG-3 engines shall conform to this platform mapping specification in order to access run-time environment services. + +MHEG-3 engine implementations shall document in their conformance document the platform mapping specification(s) to which they conform. + +NOTE – If existing software does not comply with the platform mapping specification and needs to be accessed from MHEG-SIR scripts, it may be embedded into an interface that translates its own interface conventions into those of the platform mapping specification. + +### **10.2 Declaration of IDL interfaces** + +The interface of external software intended for use by an interchanged script may contain: + +- operation declarations; +- exception declarations; +- type declarations. + +Types shall be declared in the type declaration of this interchanged script. + +Operations and exceptions shall be declared in the package declaration of this interchanged script. This package declaration shall be assigned a package identifier and shall consist of: + +- the name of the package; + +- a set of service descriptions; +- a set of exception descriptions. + +Service descriptions shall be assigned a function identifier and shall consist of: + +- the name of the operation; +- the function signature, i.e. the type and passing mode of each parameter and the type of the return value. + +Exception descriptions shall be assigned a message identifier and shall consist of: + +- the name of the exception; +- the exception signature, i.e. the type of each member. + +Identifiers (package identifiers, type identifiers, function identifiers) are used by MHEG-SIR scripts to refer to types and functions; a function identifier for an external operation can be built from a package identifier and the index of the service declaration in this package, while a message identifier for an external exception can be built from a package identifier and the index of the exception declaration in this package. + +Names (package names, operation names, exception names) shall be used by the script interpreter to link with the actual implementation of the external software. + +An MHEG-SIR package declaration lies at the same abstraction level as an IDL specification. This Recommendation defines the rules for mapping an IDL specification into a package declaration. Clause 14 specifies: + +- how an IDL data type description shall be mapped to an MHEG-SIR data type description; +- how an IDL operation description shall be mapped to an MHEG-SIR service description; +- how an IDL exception description shall be mapped to an MHEG-SIR exception description. + +### 10.3 Invocation of external operations in an MHEG-SIR program + +A service described in a package declaration shall be invoked from an MHEG-SIR program as follows: + +- variables of expected types corresponding to the return value (if any) and to each parameter shall be declared within the interchanged script (except the originating object's object reference, which shall be implicit); +- the program shall assign those variables which correspond to input or input/output parameters; +- the program shall push onto the stack the data identifiers of all these variables in right-to-left order [the identifier of the variable corresponding to the return value is pushed first, then the actual parameters, with the object reference (implicit parameter) of the target being pushed last]; +- the program shall invoke the operation using an **external call** (XCALL) instruction with the function identifier of the invoked operation as operand; +- the program shall exploit the function results using the variables corresponding to the return value, the **inout** parameters and the **out** parameters. + +### 10.4 Handling of external exceptions in an MHEG-SIR program + +An exception described in a package declaration shall be handled by an MHEG-SIR program as follows: + +- variables of expected types corresponding to each member shall be declared within the interchanged script (except the originating object's object reference, which shall be implicit); +- a routine whose parameters correspond to the exception members shall be declared within the routine declaration part of the interchanged script; +- the mapping between the identifiers of this handling routine and the exception shall be declared in the handler declaration part of the interchanged script. + +### 10.5 Invocation of external operations by an MHEG-3 engine + +When an interchanged script expresses invocation of an operation as described in 10.3, the script interpreter shall behave as described by the semantics of the **XCALL** instruction in clause 13. As part of this performance, it shall interpret the mechanisms described in 10.3 in translating them into the run-time environment access mechanisms as defined by the platform mapping specifications. + +NOTE – For instance, an MHEG-3 engine may translate a variable identifier pushed onto the stack as a service parameter into either a value or a real memory address to be passed to the external software that provides the service. + +### 10.6 Handling of external exceptions by an MHEG-3 engine + +When an exception is raised by an external service, this results in a message being transmitted to the MHEG-3 engine according to the run-time environment access mechanisms defined by the platform mapping specifications. + +The script interpreter shall then behave as described in 9.5.1.2. + +### 10.7 Platform mapping specifications + +A platform mapping specification shall contain all of the following: + +- the description of the platform to which the specification applies; +- the **package availability** procedure, which MHEG-3 engines shall use to check the availability of a given package within the run-time environment; +- the **package load** procedure, which MHEG-3 engines shall use to make the operations of a given package accessible to an rt-script; +- the **package unload** procedure, which MHEG-3 engines shall use to unload a package; +- the **operation invocation** procedure, which MHEG-3 engines shall use to invoke a given operation; +- the **data encoding** rules, which MHEG-3 engines shall use to encode the value of **in** or **inout** parameters of an operation and to decode the value of **out** or **inout** parameters of an operation or exception members; +- the **parameter passing** procedures, which MHEG-3 engines shall use to pass **in**, **inout** and **out** parameters to an operation; +- the **return value retrieval** procedure, which MHEG-3 engines shall use to retrieve the return value of an operation; +- the **exception retrieval** procedure, which MHEG-3 engines shall use to retrieve exceptions raised by an operation. + +The contents of a platform mapping specification are defined in Annex D. + +## **11 Provisions for MHEG object manipulation** + +This clause describes the mechanisms defined by this Recommendation to make it possible for rt-scripts to manipulate MHEG objects. + +### **11.1 Invoking MHEG actions** + +MHEG-SIR is used to express invocation of MHEG actions as defined by the MHEG API. + +The MHEG API is defined using IDL. The mapping from an IDL definition to an MHEG-SIR package declaration and type declaration is defined in clause 14. However, the MHEG API package is considered as a predefined one. So its declaration shall not be included explicitly in interchanged scripts. The mapping mechanism is similar to the external function declaration mechanism described in clause 10, except that the IDL types and operations defined by the MHEG API shall not be declared as part of the MHEG-SIR code, but are instead dealt with as predefined types and predefined external functions. + +The mechanism used to invoke an MHEG action is similar to the invocation of a service provided by the run-time environment. An **XCALL** instruction is used. Types defined in the MHEG API package are referred to using a predefined type identifier. Functions described in the MHEG API package are referred to using a predefined function identifier. + +#### **11.1.1 Sending messages to other scripts** + +The MHEG-3 API package is considered as a predefined one. Within an interchanged script, messages may be efficiently targeted at other scripts using the predefined functions mapping MHEG-3 API operations. An rt-script can thus pass and receive parameters and call routines from another rt-script. + +NOTE – This may be used to implement the concept of "library" or "utility" scripts. This may also be used to synchronize rt-scripts. + +#### **11.1.2 Exchange of information with MHEG objects** + +Exchange of information between an rt-script and other MHEG entities (including other rt-scripts) may be expressed using the MHEG API operations mapping the MHEG "set data" and "get data" actions. MHEG content objects embedding generic values may be used to constitute a shared memory area among MHEG objects. + +Waiting for a signal from another object may be translated by a loop including a call to the MHEG API operation mapping the MHEG "get data" action until the expected value is retrieved. + +Generating a signal may be translated by a call to the MHEG API operation corresponding to the "set data" MHEG action. + +NOTE – As far as exchange of information among rt-scripts is concerned, use of the mechanism described in 11.1.1 is recommended. + +### **11.2 Receiving MHEG messages** + +MHEG-SIR is used to express handling of messages resulting from MHEG actions. These messages may be either of the following: + +- MHEG-3 API **run** operations; +- MHEG API exceptions. + +### 11.2.1 MHEG-3 API run operations + +The MHEG "set parameters" and "run" actions that may be targeted to an rt-script should result in the MHEG-3 API **setParameter** and **run** operations. Invocation of the **run** operation results in a message being inserted into the rt-script's message queue with: + +- as message identifier, a predefined message identifier which is mapped to the routine identifier of the targeted routine; +- as members, the parameters previously set by the **setParameter** operation. + +### 11.2.2 MHEG API exceptions + +The MHEG API exceptions are considered as messages which are sent to the script interpreter as the result of invoking an MHEG API operation. These exceptions have predefined message identifiers. The script interpreter shall process these messages in the same way as it would process an exception coming from the run-time environment, as described in 9.5.1.2. + +## 12 MHEG-SIR declarations + +This clause defines the structure of interchanged scripts. This clause also specifies the way the virtual machine deals with parsing of an interchanged script. + +The following notation conventions are used: + +- non-terminals are written as normal text; +- terminal types are written in uppercase; +- enumerated values are enclosed in single quotes; +- "==" indicates a definition; +- "|" indicates a choice in a production; +- "\*" indicates zero or more occurrences of the preceding type; +- "+" indicates one or more occurrences of the preceding type; +- "?" indicates zero or one occurrence of the preceding type (optional type). + +NOTE – The complete grammar of interchanged scripts is described in Appendix I. + +An interchanged script shall consist of: + +- a sequence of type declarations; +- a sequence of constant declarations; +- a sequence of global variable declarations; +- a sequence of package declarations; +- a sequence of message handler declarations; +- a sequence of routine declarations. + +**InterchangedScript** ::= **TypeDeclaration\*** +**ConstantDeclaration\*** +**VariableDeclaration\*** +**PackageDeclaration\*** +**HandlerDeclaration\*** +**RoutineDeclaration\*** + +## 12.1 Type declaration + +Type declarations are used to describe the types of the interchanged script. + +A type declaration shall consist of: + +- a type identifier (optional); +- a type description. + +**TypeDeclaration ::= TypeIdentifier? +TypeDescription** + +### 12.1.1 Type identifier + +Type identifiers are used to reference the type description throughout the interchanged script. + +The type identifier shall be a positive integer within the range allowed for declared types. It shall correspond to the maximum number of predefined types incremented by the index (starting at 0) of the declaration in the type declarations part. + +If the type identifier is not provided, it shall be computed by the script parser. + +**TypeIdentifier ::= INTEGER** + +### 12.1.2 Type description + +Type descriptions describe the structure of a declared type. + +The type description shall be one of the following: + +- a string description; +- a sequence description; +- an array description; +- a structure description; +- a union description. + +**TypeDescription ::= SequenceDescription +| StringDescription +| ArrayDescription +| StructureDescription +| UnionDescription** + +#### 12.1.2.1 String description + +A string description shall consist of an integer (optional). + +**StringDescription ::= INTEGER? // String (max) size** + +The integer represents the maximum size of the string; if it is not provided, the string shall be unbounded. + +#### 12.1.2.2 Sequence description + +A sequence description shall consist of: + +- an integer (optional); +- a type identifier. + +**SequenceDescription ::= INTEGER? // Sequence (max) size +TypeIdentifier** + +The integer represents the maximum size of the sequence; if it is not provided, the sequence shall be unbounded. + +The type identifier represents the type of element of the sequence. + +### 12.1.2.3 Array description + +An array description shall consist of: + +- an integer; +- a type identifier. + +**ArrayDescription** ::= **INTEGER** // Array size +**TypeIdentifier** + +The integer represents the size of the array. + +The type identifier represents the type of element of the array. + +### 12.1.2.4 Structure description + +A structure description shall consist of a sequence of type identifiers. + +**StructureDescription** ::= **TypeIdentifier**+ + +Each type identifier represents the type of one of the fields of the structure. + +### 12.1.2.5 Union description + +A union description shall consist of a sequence of one or more type identifiers. + +**UnionDescription** ::= **TypeIdentifier**+ + +Each type identifier represents the type of one of the choices of the union. + +## 12.2 Constant declaration + +Constant declarations are used to describe the types and values of the constants of the interchanged script. + +A constant declaration shall consist of: + +- a data identifier (optional); +- a type identifier; +- a constant value. + +**ConstantDeclaration** ::= **DataIdentifier?** +**TypeIdentifier** +**ConstantValue** + +### 12.2.1 Data identifier + +Data identifiers are used to reference data throughout the interchanged script. + +The data identifier shall be a positive integer within the range allowed for constants. It shall correspond to the index (starting from 0) of the declaration in the constant declarations part. + +If the data identifier is not provided, it shall be computed by the script parser. + +**DataIdentifier** ::= **INTEGER** + +### 12.2.2 Type identifier + +The type identifier represents the type to which the value of the constant belongs. + +### 12.2.3 Constant value + +The constant value represents the value to which the constant corresponds throughout the script. + +If the type of the constant is a primitive or **string** type, the constant value shall consist of an immediate value expressed in this type. + +If the type of the constant is a **sequence** type, the constant value shall consist of a sequence of constant values, whose length is less or equal to the size of the **sequence** type and whose type is the element type of the sequence description. + +If the type of the constant is an **array** type, the constant value shall consist of a sequence of constant values, whose length is equal to the size of the **array** type and whose type is the element type of the array description. + +If the type of the constant is a **structure** type, the constant value shall consist of a sequence of constant values, whose length is equal to the number of elements in the **structure** type; each of these values shall be of the same type as the corresponding element type in the structure description. + +If the type of the constant is a **union** type, the constant value shall consist of an integer representing the index (starting from 0) of the choice in the **union** type and a constant value whose type is the type of element of the corresponding rank in the union description. + +``` +ConstantValue ::= BOOLEAN + | OCTET + | INTEGER // all numeric types + | REAL // float or double + | STRING // character or string + | DataIdentifier + | ConstantValue* // sequence, array or structure + | UnionValue + +UnionValue ::= INTEGER // Tag index + ConstantValue +``` + +## 12.3 Global variable declaration + +Global variable declarations are used to describe the types and initial values of the global variables of the interchanged script. + +A global variable declaration shall consist of: + +- a data identifier (optional); +- a type identifier; +- a constant reference (optional). + +``` +VariableDeclaration ::= DataIdentifier? + TypeIdentifier + ConstantReference? // Initial value +``` + +### 12.3.1 Data identifier + +Data identifiers are used to reference data throughout the interchanged script. + +The data identifier shall be a positive integer within the range allowed for global variables. It shall correspond to the maximum number of constants incremented by the index (starting from 0) of the declaration in the global variable declarations part. + +If the data identifier is not provided, it shall be computed by the script parser. + +### 12.3.2 Type identifier + +The type identifier represents the type to which the value of the global variable belongs. + +### 12.3.3 Constant reference + +The constant reference represents the initial value of the global variable. + +The constant reference shall be one of the following: + +- a data identifier referencing a constant; +- a constant value as described in 12.2.3. + +In any case, the value to which this constant reference refers shall be of the type of the global variable. + +If the constant reference is not provided, the script interpreter shall assign the global variable a default value if its type allows for it. Otherwise, it shall remain undefined until assigned by an instruction. + +``` +ConstantReference ::= DataIdentifier + | ConstantValue +``` + +## 12.4 Package declaration + +Package declarations are used to describe the external services and exceptions used by the interchanged script. + +A package declaration shall consist of: + +- a package identifier (optional); +- a string representing the package name; +- a sequence of service descriptions; +- a sequence of exception descriptions. + +``` +PackageDeclaration ::= PackageIdentifier? + VisibleString // Package name + ServiceDescription* + ExceptionDescription* +``` + +### 12.4.1 Package identifier + +Package identifiers are used to reference packages throughout the interchanged script. + +The package identifier shall be a positive integer within the range allowed for packages. It shall correspond to the index (starting at 0) of the declaration in the package declarations part. + +If the package identifier is not provided, it shall be computed by the script parser. + +``` +PackageIdentifier ::= INTEGER +``` + +## 12.4.2 Name + +A package name is used by the script interpreter to access the package within the run-time environment, according to the **package availability** procedure described by the platform mapping specification. + +## 12.4.3 Service description + +Service descriptions describe external function prototypes. + +A service description shall consist of: + +- a function identifier (optional); +- a string representing the operation name; +- a calling mode (optional); +- a type identifier (optional); +- a sequence of parameter descriptions. + +``` +ServiceDescription ::= FunctionIdentifier? + VisibleString? // IDL global name + CallingMode? + TypeIdentifier? // return value + ServiceParameterDescription* +``` + +### 12.4.3.1 Function identifier + +Function identifiers are used to reference functions throughout the interchanged script. + +The function identifier shall be a positive integer within the range allowed for services. It shall correspond to the maximum number of routines plus the maximum number of predefined functions plus the package identifier multiplied by 256, incremented by the index (starting from 0) of the service in the package declaration. + +If the function identifier is not provided, it shall be computed by the script parser. + +``` +FunctionIdentifier ::= INTEGER +``` + +### 12.4.3.2 Name + +The operation name is used by the script interpreter to access the operation within the run-time environment, according to the **operation invocation** procedure described by the platform mapping specification. + +### 12.4.3.3 Calling mode + +The calling mode represents the way the operation shall be invoked. + +The calling mode shall be either "synchronous" or "asynchronous". + +If the value is not specified, the calling mode shall be "synchronous". + +``` +CallingMode ::= 'SYNCHRONOUS' | 'ASYNCHRONOUS' +``` + +### 12.4.3.4 Type identifier + +The type identifier represents the type of return value of the service. + +If the type identifier is not specified, it shall be interpreted as a **void** type, i.e. the function shall have no return value. + +If the calling mode of the operation is "asynchronous", the type identifier shall be either "void" or not specified. + +#### 12.4.3.5 Parameter description + +Parameter descriptions are used to specify the type and passing mode of service parameters. + +A parameter description shall consist of: + +- a passing mode; +- a type identifier. + +**ServiceParameterDescription ::= ServicePassingMode? +TypeIdentifier** + +##### 12.4.3.5.1 Passing mode + +The passing mode indicates whether the value of the parameter at the time of invocation of the service is used by the service (input parameter) and whether this parameter is modified by the service for use by its caller (output parameter). + +The passing mode shall be one of the following: "in", "inout" or "out". + +If the passing mode is not specified, it shall be interpreted as an **in** parameter. + +NOTE – The object reference parameter is implicit, so it should not be specified as part of the declaration. It is dealt with as an **in** parameter. + +If the calling mode of the operation is "asynchronous", the passing mode shall be either "in" or not specified. + +**ServicePassingMode ::= 'IN' | 'OUT' | 'INOUT'** + +##### 12.4.3.5.2 Type identifier + +The type identifier represents the type of the considered service parameter. + +#### 12.4.4 Exception description + +Exception descriptions describe prototypes of exceptions that may be raised during the execution of external functions. + +An exception description shall consist of: + +- a message identifier (optional); +- a string representing the exception name; +- a sequence of type identifiers representing the members of the exception. + +**ExceptionDescription ::= MessageIdentifier? +VisibleString? //IDL exception global name +TypeIdentifier\* //Parameter types** + +##### 12.4.4.1 Message identifier + +Message identifiers are used to reference messages throughout the interchanged script. + +The message identifier shall be a positive integer within the range allowed for exceptions. It shall correspond to the maximum number of predefined messages plus the package identifier multiplied by 256, incremented by the index (starting at 0) of the exception in the package declaration. + +If the message identifier is not provided, it shall be computed by the script parser. + +**MessageIdentifier ::= INTEGER** + +#### **12.4.4.2 Name** + +An exception name is used by the script interpreter to retrieve the exception within the run-time environment, according to the **exception retrieval** procedure described by the platform mapping specification. + +#### **12.4.4.3 Parameter description** + +Each parameter of the message corresponds to one member of the exception. It is described by its type identifier. + +### **12.5 Handler declaration** + +Handler declarations are used to associate a message with the function that handles it. + +A handler declaration shall consist of: + +- a message identifier; +- a function identifier. + +**HandlerDeclaration ::= MessageIdentifier +FunctionIdentifier** + +#### **12.5.1 Message identifier** + +The message identifier indicates the message to be handled. + +The message identifier shall be a positive integer within the whole range allowed to messages, representing either a predefined message or an exception. + +#### **12.5.2 Function identifier** + +The function identifier indicates the function to be triggered when the message is removed from the message queue. + +The function identifier shall be a positive integer within the whole range allowed to function, representing a routine, a predefined function or a service. + +The description of the formal parameter types for the function shall be the same as for the message, so that the function may be called with the message actual parameters as its parameters. If signatures do not match, the handler shall be rejected by the script parser. + +### **12.6 Routine declaration** + +Routine declarations are used to describe the structure and program code of the internal functions of the interchanged script. + +A routine declaration shall consist of: + +- a function identifier (optional); +- a type identifier (optional); +- a sequence of parameter descriptions; +- a sequence of local variable declarations; +- MHEG-SIR program code. + +``` + +RoutineDeclaration ::= FunctionIdentifier? +TypeIdentifier? // for return value +RoutineParameterDescription* +LocalVariableDeclaration* +OCTET STRING // program code + +``` + +### 12.6.1 Function identifier + +The function identifier shall be a positive integer within the range allowed for routines. It shall correspond to the index (starting from 0) of the routine in the routine declarations part. + +If the function identifier is not provided, it shall be computed by the script parser. + +### 12.6.2 Type identifier + +The type identifier represents the type of return value of the routine. + +If the type identifier is not specified, it shall be interpreted as a **void** type, i.e. the function shall have no return value. + +### 12.6.3 Parameter description + +Parameter descriptions are used to specify the type and passing mode of routine parameters. + +A parameter description shall consist of: + +- a passing mode (optional); +- a type identifier. + +``` + +RoutineParameterDescription ::= RoutinePassingMode? +TypeIdentifier + +``` + +#### 12.6.3.1 Passing mode + +The passing mode indicates whether the parameter shall be passed to the routine using its **value** (input parameter) or a **reference** to the variable that holds its value (input/output parameter). + +The passing mode shall be one of the following: "value" or "reference". + +``` + +RoutinePassingMode ::= 'VALUE' | 'REFERENCE' + +``` + +#### 12.6.3.2 Type identifier + +The type identifier represents the type of the considered routine parameter. + +### 12.6.4 Local variable declaration + +Local variable declarations are used to describe the types and initial values of variables whose scope is limited to one execution of a routine. + +A local variable declaration shall have the same structure as a global variable declaration, as defined in 12.3. It shall consist of: + +- a data identifier (optional); +- a type identifier; +- a constant reference (optional). + +#### 12.6.4.1 Data identifier + +The data identifier shall be a positive integer within the range allowed for local variables. It shall correspond to the maximum number of constants plus the maximum number of global variables + +incremented by the index (starting from 0) of the declaration in the local variable declarations of the routine, incremented by the number of formal parameters of the routine. + +If the data identifier is not provided, it shall be computed by the script parser. + +#### 12.6.4.2 Type identifier + +The type identifier represents the type to which the value of the local variable belongs. + +#### 12.6.4.3 Constant reference + +The constant reference represents the initial value of the local variable. + +The constant reference shall be one of the following: + +- a data identifier referencing a constant; +- a constant value as defined in 12.2.3. + +In any case, the value to which this constant reference refers shall be of the type of the local variable. + +If the constant reference is not provided, the script interpreter shall assign the local variable a default value if its type allows for it. Otherwise, it shall remain undefined until assigned by an instruction. + +#### 12.6.5 Program code + +The program code consists of the sequence of instructions of the routine, intended for execution by the script interpreter when the routine is triggered. The syntax and semantics of the MHEG-SIR instructions is described in clause 13. + +The last instruction of a routine shall be a **RET** instruction. + +### 13 MHEG-SIR instructions + +This clause defines the semantics of the MHEG-SIR instructions. + +#### 13.1 Presentation methodology + +Each instruction is defined in the corresponding subclause by a set of entries as follows: + +| | | +|-----------------------|--------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | A brief description of the instruction's semantics. | +| Synopsis: | Mnemonic Operand1 ... OperandN | +| Operands: | A description of the types and semantics of each operand carried with the instruction (if any). | +| Stack: | A visual synopsis of the instruction's effect on the parameter stack, e.g.
..., Parameter1, Parameter2 ⇨ ..., Result | +| Types: | A list of the types of parameters to which the instruction applies (if it is a template instruction). | +| Parameters: | A description of the semantics of each element of the parameter stack which is popped, pushed or otherwise effected by the instruction (if any). | +| Effect: | A textual specification of the interpretation semantics of the instruction. | +| Formal specification: | A formal specification of the interpretation semantics of the instruction using the notation described in this subclause. | +| Errors: | A list of the errors that may be raised during execution of the instruction. | + +### 13.1.1 Error conditions + +The semantics of the instruction, as described by the formal specification, shall apply only if the operands are valid. Otherwise, an **InstructionExecutionError** exception shall be raised and the error register shall be set to **InvalidOperand**. The result of the instruction execution is unspecified. + +When the parameter stack is looked up, i.e. on a **PS.pop** or a **PS[SP]** primitive, if the parameter stack does not hold enough parameters then an **InstructionExecutionError** exception shall be raised and the error register shall be set to **StackUnderflow**. The resulting state of the parameter stack is unspecified. + +If the result of an arithmetic operation falls in a range that exceeds that of the target type, arithmetic operations shall raise an **InstructionExecutionError** exception and the error register shall be set to **ArithmeticOverflow** or **DivisionByZero**, as applicable. + +If an identifier does not refer to a valid entity (type, data, function, message, package) then when its value in the corresponding table is accessed (e.g. using **DT[i]**), an **InstructionExecutionError** exception shall be raised and the error register shall be set to **InvalidIdentifier**. + +If IP is set to an invalid pointer then an **InstructionExecutionError** exception shall be raised and the error register shall be set to **JumpOutOfRange**. + +When a dynamic variable is allocated and allocation is impossible due to lack of memory space or data identifiers, then the **new()** primitive shall raise an **InstructionExecutionError** exception and set the error register to **AllocationFailed**. + +Triggering of the other error conditions is specified explicitly throughout 13.3. The error code values are defined in Annex C. + +### 13.1.2 Formal specification + +The "formal specification" entry of an instruction description gives a concise formal notation of the effect that the instruction execution unit shall produce as it interprets the instruction; however, as this specification is expressed in terms of a sequence of operations, there may be other methods to lead to the same result, so this formal specification does not require the instruction execution unit to perform as expressed as long as the effect is the same. + +The error cases described in 13.1.1 are implicit and are not expressed in the formal specification. The other error cases are explicitly mentioned. + +To specify the semantics of an instruction in a formal way, a C-like syntax is used. It uses the notations and concepts defined in clauses 8 and 9, plus the following notations: + +- Data Table (DT) notation (see 13.1.3); +- template instruction notation (see 13.1.4); +- primitives (see 13.1.5). + +### 13.1.3 Data table notation + +The notation **DT(i)**, where **i** stands for a data identifier, corresponds to: + +- the entry whose key is **i** in the constant table, if **i** is the data identifier of a constant; +- the entry whose key is **i** in the global variable table, if **i** is the data identifier of a global variable; +- the entry whose key is **i** in the local variable table of the currently executing routine, if **i** is the data identifier of a local variable; +- the dynamic variable whose handle is mapped to **i**, if **i** is the data identifier of a dynamic variable. + +This macro may be expressed as follows: + +``` +#define DT(i) (i < 4096) ? CT[i] : VT[i] +``` + +#### 13.1.4 Template instruction notation + +A number of instructions (e.g. arithmetic and logical instruction) operate on values of a given type and produce a result with the same type. The **** notation is used to express a template instruction. **\_** represents all instructions **** with **** being replaced by the type letter of any primitive type to which the instruction is applicable, as described by the "Types" entry in the instruction description. + +NOTE – Operations on mixed types should be handled by explicitly inserting type conversion instructions in the instruction sequence. + +#### 13.1.5 Primitives + +The following primitive notations are used in the formal specification of the instructions: + +- **DID new(tid)**: allocates a dynamic variable of the type identifier by **tid**; +- **void raise(exc)**: raises an **InstructionExecutionError** exception and sets ER to error code **exc**; +- **void delete(did)**: releases the dynamic variable identified by **did**; +- **int sizeof(tid)**: returns the size of values of the type identified by **tid**, expressed in the same units as the PS pointer addresses; +- **type()**: macro to be replaced by the C type name. + +### 13.2 Classification of MHEG-SIR instructions + +The MHEG-SIR instructions may be clustered into categories according to their effect on the control flow, on the variable tables or on the parameter stack, and according to the types of stack parameters that they accept: + +- a) Instructions that affect the control flow: + - 1) unconditional jump instructions: **JMP**, **LJMP**; + - 2) conditional jump instructions: **JT**, **JF**, **LJT**, **LJF**; + - 3) function invocations: **CALL**, **XCALL**; + - 4) miscellaneous control flow instructions: **RET**, **YIELD**. +- b) Instructions that do not affect the control flow, but affect the value of variables: + - 1) complex variable modifiers: **SET**, **SETC**; + - 2) arithmetic operators on variables: **INC**, **DEC**; + - 3) stack pop instructions: **POPR**, **POP**, **POPC**; + - 4) memory management instructions: **ALLOC**, **FREE**. +- c) Instructions that do not affect the control flow or the variables, but affect the parameter stack: + - 1) conversion instructions: **CVT**; + - 2) arithmetic operators: **ADD**, **SUB**, **MUL**, **DIV**, **REM**, **NEG**; + - 3) logical operators: **AND**, **OR**, **XOR**, **NOT**; + - 4) logical shift operators: **SHIFT**; + - 5) comparison operators: **EQ**, **GT**, **LT**, **EQR**; + - 6) complex data accessors: **GET**, **GETC**; + +7) miscellaneous stack manipulation instructions: **PUSHI, PUSHR, PUSH, DUP, GETOR**. + +d) instructions that have no effect: **NOP**. + +NOTE – Most instructions only operate on primitive type values. Only the following instructions are used to manipulate constructed values: **EQR, GET, GETC, SET, SETC, ALLOC, FREE, CALL, XCALL**. + +The effect of instructions is summarized in Table 3. The operations are listed in canonical order, i.e. by ascending op-code number. Some mnemonics represent template instructions and therefore have type suffixes. + +**Table 3/T.173 – Synopsis of MHEG-SIR instructions and their effect** + +| Mnemonics | Ref. | Opcode (hexa) | Op. size | Op. type | Parameter types | PS effect | VT effect | Control flow effect | +|------------------------|---------|---------------|----------|----------|-----------------|-----------|-----------|---------------------| +| NOP | 13.3.1 | 00 | 0 | | | | | | +| YIELD | 13.3.2 | 02 | 0 | | | | | x | +| RET | 13.3.3 | 03 | 0 | | | 0 1 ⇔ 0 1 | | x | +| FREE | 13.3.4 | 08 | 0 | | | 1 ⇔ 0 | x | | +| NOT <T> | 13.3.5 | 10-13 | 0 | | BOWU | 1 ⇔ 1 | | | +| OR <T> | 13.3.6 | 14-17 | 0 | | BOWU | 2 ⇔ 1 | | | +| XOR <T> | 13.3.7 | 18-1B | 0 | | BOWU | 2 ⇔ 1 | | | +| AND <T> | 13.3.8 | 1C-1F | 0 | | BOWU | 2 ⇔ 1 | | | +| EQR | 13.3.9 | 20 | 0 | | | 2 ⇔ 1 | | | +| EQ <T> | 13.3.10 | 21-2B | 0 | | OSLWUFDBCIR | 2 ⇔ 1 | | | +| LT <T> | 13.3.11 | 30-37 | 0 | | COSLWUFD | 2 ⇔ 1 | | | +| GT <T> | 13.3.12 | 38-3F | 0 | | COSLWUFD | 2 ⇔ 1 | | | +| ADD <T> | 13.3.13 | 40-47 | 0 | | OSLWUFD | 2 ⇔ 1 | | | +| SUB <T> | 13.3.14 | 48-4F | 0 | | OSLWUFD | 2 ⇔ 1 | | | +| MUL <T> | 13.3.15 | 50-57 | 0 | | OSLWUFD | 2 ⇔ 1 | | | +| DIV <T> | 13.3.16 | 58-5F | 0 | | OSLWUFD | 2 ⇔ 1 | | | +| NEG <T> | 13.3.17 | 62-67 | 0 | | SLFD | 1 ⇔ 1 | | | +| REM <T> | 13.3.18 | 79-7D | 0 | | OSLWU | 2 ⇔ 1 | | | +| DUP <T> | 13.3.19 | 81-8B | 0 | | OSLWUFDBCIR | 1 ⇔ 2 | | | +| CVT <TT> | 13.3.20 | 94-BE | 0 | | OSLWUFDBC | 1 ⇔ 1 | | | +| JT | 13.3.21 | C0 | 1 | offset | | 1 ⇔ 0 | | x | +| JF | 13.3.22 | C1 | 1 | offset | | 1 ⇔ 0 | | x | +| JMP | 13.3.23 | C2 | 1 | offset | | | | x | +| SHIFT <T> | 13.3.24 | C5-C7 | 1 | offset | OWU | 1 ⇔ 1 | | | +| GETOR | 13.3.25 | C9 | 1 | PID | | 0 ⇔ 1 | | | +| LJT | 13.3.26 | D0 | 2 | offset | | 1 ⇔ 0 | | x | +| LJF | 13.3.27 | D1 | 2 | offset | | 1 ⇔ 0 | | x | +| LJMP | 13.3.28 | D2 | 2 | offset | | | | x | +| CALL | 13.3.29 | D4 | 2 | FID | | n ⇔ 0 1 | | x | +| XCALL | 13.3.30 | D6 | 2 | FID | | n ⇔ 0 1 | | x | +| PUSH | 13.3.31 | E0 | 2 | DID | | 0 ⇔ 1 | | | +| PUSHR | 13.3.32 | E1 | 2 | DID | | 0 ⇔ 1 | | | +| PUSHI | 13.3.33 | E3 | 2 | value | | 0 ⇔ 1 | | | +| POP | 13.3.34 | E4 | 2 | DID | | 1 ⇔ 0 | x | | +| POPR | 13.3.35 | E5 | 2 | DID | | 1 ⇔ 0 | x | | +| POPC | 13.3.36 | E6 | 2 | DID | | 1 ⇔ 0 | x | | +| ALLOC | 13.3.37 | E8 | 2 | TID | | 0 ⇔ 1 | x | | +| INC | 13.3.38 | EA | 2 | DID | | 1 ⇔ 0 | x | | +| DEC | 13.3.39 | EB | 2 | DID | | 1 ⇔ 0 | x | | + +**Table 3/T.173 – Synopsis of MHEG-SIR instructions and their effect (*concluded*)** + +| Mnemonics | Ref. | Opcode (hexa) | Op. size | Op. type | Parameter types | PS effect | VT effect | Control flow effect | +|-------------|---------|---------------|----------|----------|-----------------|-----------------------|-----------|---------------------| +| GET | 13.3.40 | F0 | 3 | DID, idx | | idx $\Rightarrow$ 1 | | | +| GETC | 13.3.41 | F2 | 3 | DID, idx | | idx+1 $\Rightarrow$ 0 | x | | +| SET | 13.3.42 | F4 | 3 | DID, idx | | idx+1 $\Rightarrow$ 0 | x | | +| SETC | 13.3.43 | F6 | 3 | DID, idx | | idx+1 $\Rightarrow$ 0 | x | | + +### 13.3 Description of instructions + +#### 13.3.1 No operation + +Short description: Do nothing. + +Synopsis: **NOP** + +Operands: None. + +Types: Not applicable. + +Parameters: None. + +Stack: ... $\Rightarrow$ ... + +Effect: None. + +Formal specification: **0;** + +Errors: + +#### 13.3.2 Yield + +Short description: Handle pending messages. + +Synopsis: **YIELD** + +Operands: None. + +Stack: ... $\Rightarrow$ ... + +Types: Not applicable. + +Parameters: None. + +Effect: If there is a pending message in the message queue, handle it by calling the corresponding routine. Upon returning, iterate the process until the message queue is empty. + +Formal specification: + +``` + +while (QP != 'null') +{ + FID fid = HT[MQ[QP].MID].FID; + if (fid == 'null') then raise('HandlerNotFound'); + else + { + CS.push({IP-1, FR, SP, LT}); + // IP-1: allows to re-iterate the YIELD instruction + FR = fid; + IP = RT[FR].IP; + LT = MQ[QP].LT; + } + MQ.remove(); +} + +``` + +Errors: **HandlerNotFound** + +### 13.3.3 Return + +Short description: Return to caller. + +Synopsis: **RET** + +Operands: None. + +Stack: ..., (Val) ⇨ ..., (Val) + +Types: Not applicable. + +Parameters: If the current routine signature has a return value, **Val** shall be interpreted as of the type of this return value. + +Otherwise, no stack parameter shall be considered. + +Effect: Return to the calling routine. Pop the call stack and restore the context of the previous frame. If the current routine has a return value, check that there is a value of the same type on the top of the parameter stack. If there is no calling function to return to, stop and go back to **ready** status. + +Formal specification: + +``` + +if (sizeof(RT[FR].TID) != (SP - CS[FP].SP)) + then raise('InvalidReturnValue'); +IP = CS[FP].IP; +FR = CS[FP].FR; +LT = CS[FP].LT; +CS.pop(); + +``` + +Errors: **InvalidReturnValue** + +### 13.3.4 Free + +Short description: Release dynamic variable. + +Synopsis: **FREE** + +Operands: None. + +Stack: ..., **Did** ⇨ ... + +Types: Not applicable. + +Parameters: **Did** shall be interpreted as a data identifier. + +| | | +|-----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Effect: | Check that Did is the data identifier of a dynamic variable. Release the dynamic memory associated with Did , and make the data identifier invalid. | +| Formal specification: | if (did < 8100h) then raise('InvalidParameter');
delete(VT[PS.pop('data identifier')]); | +| Errors: | StackUnderflow
InvalidIdentifier | + +### 13.3.5 Not + +| | | +|-----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | Logical negation. | +| Synopsis: | NOT_<T> | +| Operands: | None. | +| Stack: | ..., Val \Rightarrow ..., Neg | +| Types: | Boolean or any unsigned integer (B, O, W, U). | +| Parameters: | Val shall be interpreted as of type
Neg shall be of type . | +| Effect: | Replace the top element of the parameter stack by its logical negation if is B , its bitwise negation otherwise (i.e. its complement-to-one):
Neg = ~Val | +| Formal specification: | type(<T>) buf = PS.pop(<T>);
if (<T> == 'boolean') then PS.push(! buf);
else PS.push(~ buf); | +| Errors: | StackUnderflow | + +### 13.3.6 Or + +| | | +|-----------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | Logical disjunction. | +| Synopsis: | OR_<T> | +| Operands: | None. | +| Stack: | ..., Val1, Val2 \Rightarrow ..., Disj | +| Types: | Boolean or any unsigned integer (B, O, W, U). | +| Parameters: | Val1 and Val2 shall be interpreted as of type .
Disj shall be of type . | +| Effect: | Replace the top two elements of the parameter stack by their logical disjunction if is B , their bitwise disjunction otherwise:
Disj = Val1 Val2 | +| Formal specification: | type(<T>) buf = PS.pop(<T>);
if (<T> == 'boolean') then buf = buf PS.pop('boolean');
else buf = PS.pop(<T>);
PS.push(buf); | +| Errors: | StackUnderflow | + +### 13.3.7 Exclusive or + +| | | +|-----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | Logical exclusion. | +| Synopsis: | XOR_<T> | +| Operands: | None. | +| Stack: | ..., Val1, Val2 $\Rightarrow$ ..., Excl | +| Types: | Boolean or any unsigned integer (B, O, W, U). | +| Parameters: | Val1 and Val2 shall be interpreted as of type .
Excl shall be of type . | +| Effect: | Replace the top two elements of the parameter stack by their logical exclusion if is B , their bitwise exclusion otherwise:
$\text{Excl} = \text{Val1} \wedge \text{Val2}$ | +| Formal specification: | type(<T>) buf = PS.pop(<T>);
if (<T> == 'boolean') then buf = (buf != PS.pop('boolean'));
else buf ^= PS.pop(<T>);
PS.push(buf); | +| Errors: | StackUnderflow | + +### 13.3.8 And + +| | | +|-----------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | Logical conjunction. | +| Synopsis: | AND_<T> | +| Operands: | None. | +| Stack: | ..., Val1, Val2 $\Rightarrow$ ..., Conj | +| Types: | Boolean or any unsigned integer (B, O, W, U). | +| Parameters: | Val1 and Val2 shall be interpreted as of type .
Conj shall be of type . | +| Effect: | Replace the top two elements of the parameter stack by their logical conjunction if is B , their bitwise conjunction otherwise:
$\text{Conj} = \text{Val1} \& \text{Val2}$ | +| Formal specification: | type(<T>) buf = PS.pop(<T>);
if (<T> == 'boolean') then buf = buf && PS.pop('boolean');
else buf &= PS.pop(<T>);
PS.push(buf); | +| Errors: | StackUnderflow | + +### 13.3.9 Equal reference + +| | | +|--------------------|----------------------------------------------------------------------------------------------------------------| +| Short description: | Compare constructed values. | +| Synopsis: | EQR | +| Operands: | None. | +| Stack: | ..., Did1, Did2 $\Rightarrow$ ..., Bool | +| Types: | Not applicable. | +| Parameters: | Did1 and Did2 shall be interpreted as of data identifier type.
Bool shall be of boolean type. | + +| | | +|--------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Effect: | Check that Did1 and Did2 identify data of the same type.
Return "true" if the data identified by Did1 and Did2 are equal (see 8.2),
"false" otherwise:
Bool = (DT( Did1 ) == DT( Did2 )) | +| Formal
specification: | DID did2 = PS.pop('data identifier');
DID did1 = PS.pop('data identifier');
if (DT( did1 ).tid != DT( did2 ).tid) then raise('TypeMismatch');
if (DT( did1 ).val == DT( did2 ).val) then PS.push('true');
else PS.push('false') | +| Errors: | TypeMismatch
StackUnderflow
InvalidIdentifier | + +### 13.3.10 Equal + +| | | +|--------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | Equality. | +| Synopsis: | EQ_<T> | +| Operands: | None. | +| Stack: | ..., Val1 , Val2 ⇨ ..., Comp | +| Types: | Any primitive type except void (O, S, L, W, U, F, D, B, C, I, R). | +| Parameters: | Val1 and Val2 shall be interpreted as of type .
Comp shall be of boolean type. | +| Effect: | Replace the top two elements of the parameter stack by "true" if they are
equal and "false" otherwise:
Comp = ( Val1 == Val2 ) | +| Formal
specification: | type(<T>) buf = PS.pop();
if (buf == PS.pop()) then PS.push('true');
else PS.push('false'); | +| Errors: | StackUnderflow | + +### 13.3.11 Less than + +| | | +|--------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | Strict inferiority. | +| Synopsis: | LT_<T> | +| Operands: | None. | +| Stack: | ..., Val1 , Val2 ⇨ ..., Comp | +| Types: | Character or any numeric (C, O, S, L, W, U, F, D). | +| Parameters: | Val1 and Val2 shall be interpreted as of type .
Comp shall be of boolean type. | +| Effect: | Replace the top two elements of the parameter stack by "true" if the top
element is greater than the next, and "false" otherwise:
Comp = ( Val1 < Val2 )
To compare characters, the numeric order shall be used. | +| Formal
specification: | type(<T>) buf = PS.pop();
if (PS.pop( < buf) then PS.push('true');
else PS.push('false'); | +| Errors: | StackUnderflow | + +### 13.3.12 Greater than + +| | | +|-----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | Strict superiority. | +| Synopsis: | GT_<T> | +| Operands: | None. | +| Stack: | ..., Val1, Val2 $\Rightarrow$ ..., Comp | +| Types: | Character or any numeric (C, O, S, L, W, U, F, D). | +| Parameters: | Val1 and Val2 shall be interpreted as of type .
Comp shall be of boolean type. | +| Effect: | Replace the top two elements of the parameter stack by "true" if the top element is less than the next, and "false" otherwise:
Comp = (Val1 > Val2)
To compare characters, the numeric order shall be used. | +| Formal specification: | type(<T>) buf = PS.pop(<T>);
if (PS.pop(<T> > buf) then PS.push('true');
else PS.push('false'); | +| Errors: | StackUnderflow | + +### 13.3.13 Add + +| | | +|-----------------------|-------------------------------------------------------------------------------------------------------------| +| Short description: | Arithmetic addition. | +| Synopsis: | ADD_<T> | +| Operands: | None. | +| Stack: | ..., Num1, Num2 $\Rightarrow$ ..., Sum | +| Types: | Any numeric (O, S, L, W, U, F, D). | +| Parameters: | Num1 and Num2 shall be interpreted as of type .
Sum shall be of type . | +| Effect: | Replace the top two elements of the parameter stack by their sum:
Sum = Num1 + Num2 | +| Formal specification: | type(<T>) buf = PS.pop(<T>);
buf += PS.pop(<T>);
PS.push(buf); | +| Errors: | StackUnderflow
ArithmeticOverflow | + +### 13.3.14 Subtract + +| | | +|--------------------|-------------------------------------------------------------------------------------------------------| +| Short description: | Arithmetic subtraction. | +| Synopsis: | SUB_<T> | +| Operands: | None. | +| Stack: | ..., Num1, Num2 $\Rightarrow$ ..., Diff | +| Types: | Any numeric (O, S, L, W, U, F, D). | +| Parameters: | Num1 and Num2 shall be interpreted as of type .
Diff shall be of type . | +| Effect: | Replace the top two elements of the parameter stack by their difference:
Diff = Num1 – Num2 | + +Formal specification: **type() buf = PS.pop(); +buf = PS.pop() –buf; +PS.push(buf);** + +Errors: **StackUnderflow +ArithmeticOverflow** + +### 13.3.15 Multiply + +Short description: Arithmetic multiplication. + +Synopsis: **MUL\_** + +Operands: None. + +Stack: **..., Num1, Num2 ⇨ ..., Prod** + +Types: Any numeric (O, S, L, W, U, F, D). + +Parameters: **Num1** and **Num2** shall be interpreted as of type . +**Prod** shall be of type . + +Effect: Replace the top two elements of the parameter stack by their product: +**Prod = Num1 \* Num2** + +Formal specification: **type() buf = PS.pop(); +buf \*= PS.pop(); +PS.push(buf);** + +Errors: **StackUnderflow +ArithmeticOverflow** + +### 13.3.16 Divide + +Short description: Arithmetic division. + +Synopsis: **DIV\_** + +Operands: None. + +Stack: **..., Num1, Num2 ⇨ ..., Quot** + +Types: Any numeric (O, S, L, W, U, F, D). + +Parameters: **Num1** and **Num2** shall be interpreted as of type . +**Quot** shall be of type . + +Effect: Replace the top two elements of the parameter stack by their quotient: +**Quot = Num1/Num2** + +Formal specification: **type() buf = PS.pop(); +buf = PS.pop() / buf; +PS.push(buf);** + +Errors: **StackUnderflow +DivisionByZero** + +### 13.3.17 Negate + +Short description: Sign change. + +Synopsis: **NEG\_** + +Operands: None. + +Stack: **..., Num ⇨ ..., Opp** + +Types: Any signed numeric (S, L, F, D). + +| | | +|-----------------------|---------------------------------------------------------------------------------------| +| Parameters: | Num shall be interpreted as of type .
Opp shall be of type . | +| Effect: | Replace the top element of the parameter stack by its opposite:
Opp = -Num1 | +| Formal specification: | type(<T>) buf = PS.pop<T>;
PS.push(-buf); | +| Errors: | StackUnderflow | + +### 13.3.18 Remainder + +| | | +|-----------------------|-----------------------------------------------------------------------------------------------------------------| +| Short description: | Arithmetic remainder. | +| Synopsis: | REM_<T> | +| Operands: | None. | +| Stack: | ..., Num1, Num2 ⇨ ..., Rem | +| Types: | Any integer (O, S, L, W, U). | +| Parameters: | Num1 and Num2 shall be interpreted as of type .
Rem shall be of type . | +| Effect: | Replace the top two elements of the parameter stack by their remainder:
Rem = Num1 % Num2 | +| Formal specification: | type(<T>) buf = PS.pop(<T>;
buf = PS.pop(<T>) % buf;
PS.push(buf); | +| Errors: | StackUnderflow
DivisionByZero | + +### 13.3.19 Duplicate + +| | | +|-----------------------|------------------------------------------------------------------------| +| Short description: | Duplicate value. | +| Synopsis: | DUP_<T> | +| Operands: | None. | +| Stack: | ..., Val ⇨ ..., Val, Val | +| Types: | Any primitive type except void (O, S, L, W, U, F, D, B, C, I, R) | +| Parameters: | Val shall be interpreted as of type . | +| Effect: | Duplicate the value on the top of stack. | +| Formal specification: | type(<T>) buf = PS[SP](<T>;
PS.push(buf); | +| Errors: | StackUnderflow | + +### 13.3.20 Convert + +| | | +|--------------------|---------------------------------| +| Short description: | Convert value. | +| Synopsis: | CVT_<T1><T2> | +| Operands: | None. | +| Stack: | ..., Val ⇨ ..., Res | + +| | | +|-----------------------|-------------------------------------------------------------------------------------------------------------------------------| +| Types: | Boolean, character or any numeric (O, S, L, W, U, F, D, B, C); see allowed combinations in 13.4. | +| Parameters: | Val shall be interpreted as of type (source type).
Res shall be of type (destination type). | +| Effect: | Replace the value on the top of stack by an equivalent value in the destination type. Conversion rules defined in 13.4 apply. | +| Formal specification: | type(<T2>) buf = (type(<T2>)) (PS.pop(<T1>));
PS.push(buf); | +| Errors: | StackUnderflow | + +### 13.3.21 Jump on true + +| | | +|-----------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | "If" conditional short jump. | +| Synopsis: | JT Off | +| Operands: | Off shall be a one-byte signed offset (in complement-to-two notation) specifying the number of instructions to move forwards or backwards within the current routine. | +| Stack: | ..., Test ⇒ ... | +| Types: | Not applicable. | +| Parameters: | Test shall be interpreted as of boolean type. | +| Effect: | If the top element of the stack is "true" then
if Off is positive, jump Off instructions forwards;
if Off is negative, jump -Off instructions backwards. | +| Formal specification: | if (PS.pop('boolean')) then IP += Off; | +| Errors: | StackUnderflow
JumpOutOfRange | + +### 13.3.22 Jump on false + +| | | +|-----------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | "Else" conditional short jump. | +| Synopsis: | JF Off | +| Operands: | Off shall be a one-byte signed offset (in complement-to-two notation) specifying the number of instructions to move forwards or backwards within the current routine. | +| Stack: | ..., Test ⇒ ... | +| Types: | Not applicable. | +| Parameters: | Test shall be interpreted as of boolean type. | +| Effect: | If the top element of the stack is "false" then
if Off is positive, jump Off instructions forwards;
if Off is negative, jump -Off instructions backwards. | +| Formal specification: | if ! (PS.pop('boolean')) then IP += Off; | +| Errors: | StackUnderflow
JumpOutOfRange | + +### 13.3.23 Jump + +| | | +|-----------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | Unconditional short jump. | +| Synopsis: | JMP Off | +| Operands: | Off shall be a one-byte signed offset (in complement-to-two notation) specifying the number of instructions to move forwards or backwards within the current routine. | +| Stack: | ... $\Rightarrow$ ... | +| Types: | Not applicable. | +| Parameters: | None. | +| Effect: | If Off is positive, jump Off instructions forwards;
if Off is negative, jump -Off instructions backwards. | +| Formal specification: | IP += Off; | +| Errors: | JumpOutOfRange | + +### 13.3.24 Shift + +| | | +|-----------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | Logical shift. | +| Synopsis: | SHIFT_<T> Off | +| Operands: | Off shall be a one-byte signed offset (in complement-to-two notation) specifying the number of bit places to shift the parameter leftwards or rightwards. | +| Stack: | ..., Val $\Rightarrow$ ..., Pwr | +| Types: | Any unsigned integer (O, W, U). | +| Parameters: | Val shall be interpreted as of type .
Pwr shall be of type . | +| Effect: | Replace the top element of the stack by its value shifted right Off bits if Off is positive, or left -Off bits if Off is negative. If Off is beyond range, the result is unspecified. | +| Formal specification: | 
type(<T>) buf = PS.pop(<T>);
if (Off >= 0) then buf >>= Off;
else if (buf < 0)
    buf = -(-buf << -Off);
else buf <<= -Off;
PS.push(buf);
| +| Errors: | StackUnderflow
ShiftOutOfRange | + +### 13.3.25 Get object reference + +| | | +|--------------------|-----------------------------------------------------------------------------------------------------------| +| Short description: | Get initial object reference to package. | +| Synopsis: | GETOR Pid | +| Operands: | Pid shall be the one-byte representation of a package identifier specifying the package to access. | +| Stack: | ... $\Rightarrow$ ..., Obref | +| Types: | Not applicable. | + +Parameters:           Obref shall be of **object reference** type. + +Effect:                Retrieve an object reference to the initial object of the package. + +Formal +specification:        **if (PT[PID].sts = 'not available') then raise('BadPackageStatus');** +                         **PS.push(PT[PID].or);** + +Errors:                **InvalidIdentifier** +                         **BadPackageStatus** + +### 13.3.26 Long jump on true + +Short description:    "If" conditional long jump. + +Synopsis:             **LJT Off** + +Operands:            **Off** shall be a two-byte signed offset (in complement-to-two notation) specifying the number of instructions to move forwards or backwards within the current routine. + +Stack:                ..., **Test** ⇒ ... + +Types:                Not applicable. + +Parameters:          **Test** shall be interpreted as of **boolean** type. + +Effect:               If the top element of the stack is "true" then +                         if **Off** is positive, jump **Off** instructions forwards; +                         if **Off** is negative, jump **-Off** instructions backwards. + +Formal +specification:        **if (PS.pop('boolean')) then IP += Off;** + +Errors:                **StackUnderflow** +                         **JumpOutOfRange** + +### 13.3.27 Long jump on false + +Short description:    "Else" conditional long jump. + +Synopsis:             **LJF Off** + +Operands:            **Off** shall be a two-byte signed offset (in complement-to-two notation) specifying the number of instructions to move forwards or backwards within the current routine. + +Stack:                ..., **Test** ⇒ ... + +Types:                Not applicable. + +Parameters:          **Test** shall be interpreted as of **boolean** type. + +Effect:               If the top element of the stack is "false" then +                         if **Off** is positive, jump **Off** instructions forwards; +                         if **Off** is negative, jump **-Off** instructions backwards. + +Formal +specification:        **if ! (PS.pop('boolean')) then IP += Off;** + +Errors:                **StackUnderflow** +                         **JumpOutOfRange** + +### 13.3.28 Long jump + +| | | +|-----------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | Unconditional long jump. | +| Synopsis: | LJMP Off | +| Operands: | Off shall be a two-byte signed offset (in complement-to-two notation) specifying the number of instructions to move forwards or backwards within the current routine. | +| Stack: | ... ⇒ ... | +| Types: | Not applicable. | +| Parameters: | None. | +| Effect: | If Off is positive, jump Off instructions forwards;
if Off is negative, jump -Off instructions backwards. | +| Formal specification: | IP += Off; | +| Errors: | JumpOutOfRange | + +### 13.3.29 Call + +| | | +|--------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | Call routine. | +| Synopsis: | CALL Fid | +| Operands: | Fid shall be the two-byte representation of a function identifier specifying the routine to invoke. | +| Stack: | ..., ParN , ..., Par1 ⇒ ... | +| Types: | Not applicable. | +| Parameters: | Par1 , ..., ParN (where N is the number of parameters of the routine) are the actual parameters of the routine. They shall be interpreted as of the same type as the formal parameters of the routine when those are passed by value, and they shall be interpreted as of data identifier type and reference a variable of the same type of the formal parameters of the routine when those are passed by reference. | +| Effect: | Pop the top elements of the parameter stack and invoke the routine specified by Fid with these elements as actual parameters. For parameters passed by reference, check that the data identifier does not reference a local variable and points to data of the same type as in the signature. Push one frame onto the call stack with the current context. Initialize the local variable table for the routine. Set the instruction pointer to the first instruction of the routine. | + +| | | +|-----------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Formal specification: | 
 TID tid; CS.push(IP, FR, SP, LT); FR = Fid; LT = RT[Fid].LT; for (short i = 0; i < RT[Fid].nbp; i--) {     switch (RT[Fid].sig[i].mod)     {     case 'value':         tid = RT[Fid].sig[i].TID;         break;     case 'reference':         tid == 'data identifier';          if (8000h <= PS[SP](tid) < 8100h)             then raise('InvalidParameter');         if (RT[Fid].sig[i].TID !=             DT(PS[SP](tid)).TID)             then raise('TypeMismatch');         break;     };     LT[I+0x8000].val = PS.pop(tid); }; IP = RT[Fid].IP;
| +| Errors: | 
 InvalidIdentifier StackUnderflow TypeMismatch InvalidParameter
| + +### 13.3.30 External call + +| | | +|--------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | Call external function. | +| Synopsis: | XCALL Fid | +| Operands: | Fid shall be the two-byte representation of a function identifier specifying the service or predefined function to invoke. | +| Stack: | ..., ParN, ... , Par1 ⇨ ..., (Ret) | +| Types: | Not applicable. | +| Parameters: |

Par1 shall be interpreted as of object reference type. It indicates the reference of the IDL instance to which to apply the operation.

Par2, ..., ParN (where N is the number of parameters of the function, plus 1) are the actual parameters of the function. Whatever the passing mode, they shall be interpreted as of data identifier type.

If the function has a return value type other than void, Ret shall be of this type.

| +| Effect: | Check that the parameters reference data of the same type as in the function's signature. Pop the top elements of the parameter stack and invoke the external function specified by Fid with these elements as actual parameters. Push one frame onto the call stack with the current context. Pass parameters to and invoke the external function. If the invocation is asynchronous, pop the call stack as soon as the request is acknowledged. If the invocation is synchronous, wait for completion of the request. If an exception is raised, activate the handler of the exception. Otherwise, retrieve the function's output parameters and return value, | + +Formal +specification: + +push the return value onto the parameter stack and pop the call stack. + +``` +DID buf[ST[Fid].nbp]; +Object obref = PS.pop('object reference'); +for (short i = 0; i < ST[Fid].nbp; i++) +{ + if (ST[Fid].sig[i].TID != DT(PS[SP]('data identifier').TID)) + then raise('TypeMismatch'); + buf[i] = PS.pop('data identifier'); +}; +CS.push(IP, FR, SP, LT); +FR = Fid; +LT[0].tid = 'object reference'; +LT[0].val = obref; +for (short i = 1; i < ST[Fid].nbp; i++) + LT[i].TID = 'data identifier'; + LT[i].val = buf[i]; +} +short Pid = (Fid>>8)-64; +if (PT[Pid].sts != 'available') then raise('BadPackageStatus'); +_open_package(PT[Pid].name); +// open a context to invoke the service +_pass_in_parameter(LT[0]); +// according to the platform mapping specification procedure +for (short I=1; i 'object reference') then raise('InvalidType');** +                          **PS.push(DT(Did).val);** + Errors:               **InvalidIdentifier** +                          **InvalidType** + +### 13.3.32 Push reference + +Short description:   Push data identifier. + Synopsis:           **PUSHR Did** + Operands:           **Did** shall be the two-byte representation of a data identifier to push onto the stack. + Stack:               ... ⇒ ..., **Val** + Types:               Not applicable. + Parameters:          **Val** shall be of **data identifier** type. + Effect:               Push **Did** onto the parameter stack. + Formal specification: **PS.push(Did);** + Errors:               None. + +### 13.3.33 Push immediate + +Short description:   Push short integer. + Synopsis:           **PUSHI Int** + Operands:           **Int** shall be the two-byte representation of a signed short integer value (in complement-to-two notation) specifying the value to push onto the stack. + Stack:               ... ⇒ ..., **Val** + Types:               Not applicable. + Parameters:          **Val** shall be of **short** type. + Effect:               Push **Int** onto the parameter stack. + +Formal specification: **PS.push(Int);** + +Errors: None. + +### 13.3.34 Pop + +Short description: Pop value and assign it to a variable. + +Synopsis: **POP Did** + +Operands: **Did** shall be the two-byte representation of the data identifier of the variable to which to assign the top element of the stack. + +Stack: ..., **Val** ⇨ ... + +Types: Not applicable. + +Parameters: **Val** shall be interpreted as of the type of the variable identified by **Did**. + +Effect: Check that **Did** identifies a variable of a primitive type. Pop **Val** from the parameter stack into the variable identified by **Did**. + +Formal specification: **TID tid = VT(Did).TID; +if (tid > 'object reference') then raise('InvalidType') +VT(Did).val = PS.pop(tid);** + +Errors: **InvalidIdentifier +StackUnderflow +InvalidType** + +### 13.3.35 Pop reference + +Short description: Pop value and assign it to the variable referenced by a variable. + +Synopsis: **POPR Did** + +Operands: **Did** shall be the two-byte representation of the data identifier of a variable of **data identifier** type, whose value identifies the variable to which to assign the value of the top element of the stack. + +Stack: ..., **Val** ⇨ ... + +Types: Not applicable. + +Parameters: **Val** shall be interpreted as of the type of **VT(Did).val**. + +Effect: Check that **Did** identifies a variable of **data identifier** type. +Pop **Val** from the parameter stack and assign it to the variable identified by **Did**. + +Formal specification: **TID tid = type(VT(Did).val.TID); +if (tid != 'data identifier') then raise('InvalidType'); +VT(VT(Did).val).val = PS.pop(tid);** + +Errors: **InvalidIdentifier +StackUnderflow +InvalidType** + +### 13.3.36 Pop contents + +Short description: Pop variable and assign its value to a variable. + +Synopsis: **POPC Did1** + +| | | +|-----------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Operands: | Did1 shall be the two-byte representation of the data identifier of the variable to which to assign the value of the data identified by the top element of the stack. | +| Stack: | ..., Did2 ⇨ ... | +| Types: | Not applicable. | +| Parameters: | Did2 shall be interpreted as of data identifier type. The data identified by Did2 shall be interpreted as of the type of the data identified by Did1 . | +| Effect: | Check that Did1 and Did2 identify data of the same type.
Pop Did2 from the parameter stack and assign the value of Did2 to the variable identified by Did1 . | +| Formal specification: | DID did2 = PS.pop('data identifier');
if (VT(Did1).TID != DT(did2).TID) then raise('TypeMismatch');
VT(Did1).val = DT(did2).val; | +| Errors: | InvalidIdentifier
StackUnderflow
TypeMismatch | + +### 13.3.37 Allocate + +| | | +|-----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | Create dynamic variable. | +| Synopsis: | ALLOC Tid | +| Operands: | Tid shall be the two-byte representation of a type identifier specifying the type of the dynamic variable to allocate. | +| Stack: | ..., ⇨ ..., Did | +| Types: | Not applicable. | +| Parameters: | Did shall be of data identifier type. | +| Effect: | Generate a dynamic variable whose type is identified by Tid . Push its data identifier onto the parameter stack. | +| Formal specification: | DID did = new(Tid);
VT[did].val = 'null'; // default value for the type
VT[did].TID = Tid;
PS.push(did); | +| Errors: | AllocationFailed
InvalidIdentifier | + +### 13.3.38 Increment + +| | | +|--------------------|------------------------------------------------------------------------------------------------------------| +| Short description: | Increment variable. | +| Synopsis: | INC Did | +| Operands: | Did shall be the two-byte representation of the data identifier of the variable which to increment. | +| Stack: | ..., Val ⇨ ..., | +| Types: | Not applicable. | +| Parameters: | Val shall be interpreted as of the type of the variable identified by Did . | + +| | | +|-----------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Effect: | Check that Did identifies a variable of a numeric type. Pop the parameter stack and increment the value of the variable identified by Did by the popped value. | +| Formal specification: | TID tid = VT(Did).TID;
if (VT(Did).TID > 'double') raise('InvalidType');
VT(Did).val += PS.pop(<T>); | +| Errors: | InvalidIdentifier
StackUnderflow
InvalidType
ArithmeticOverflow | + +### 13.3.39 Decrement + +| | | +|-----------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | Decrement variable. | +| Synopsis: | DEC Did | +| Operands: | Did shall be the two-byte representation of the data identifier of the variable which to decrement. The variable identified by Did shall be of a numeric type. | +| Stack: | ..., Val ⇔ ..., | +| Types: | Not applicable. | +| Parameters: | Val shall be interpreted as of the type of the variable identified by Did . | +| Effect: | Check that Did identifies a variable of a numeric type. Pop the parameter stack and decrement the value of the variable identified by Did by the popped value. | +| Formal specification: | TID tid = VT(Did).TID;
if (VT(Did).TID > 'double') raise('InvalidType');
VT(Did).val -= PS.pop(<T>); | +| Errors: | InvalidIdentifier
StackUnderflow
InvalidType
ArithmeticOverflow | + +### 13.3.40 Get + +| | | +|--------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Short description: | Get value of element of data of constructed type. | +| Synopsis: | GET Did Lvl | +| Operands: | Did shall be the two-byte representation of the data identifier of the data to access.
Lvl shall be a one-byte unsigned quantity representing the number of nested levels to go to access the sought value. | +| Stack: | ..., Idx(Lvl) , ..., Idx(1) ⇔ ..., Val | +| Types: | Not applicable. | +| Parameters: | Idx(1) , ... Idx(Lvl) shall be interpreted as of unsigned short type.
Val shall be of the same type as the accessed element. | + +Effect: Replace a list of indices on the parameter stack by the value of the element addressed by the popped indices within the constructed type data identified by **Did**: + +**Val = DT(Did)[Idx(1),...,Idx(Lvl)]** + +Check that the accessed element is of a primitive type. If **Lvl** equals 0, perform as a **PUSH** instruction. + +Formal + +specification: + +``` +void *buf = &DT(Did); +unsigned short idx; +for (;Lvl>0; Lvl--) +{ + if (buf->TID <= 'object reference') then raise('InvalidLevel'); + idx = PS.pop('unsigned short'); + if (buf->lg < idx) then raise ('InvalidIndex'); + buf = &buf->.val[idx]; +} +if (buf->TID > 'object reference') then raise('InvalidType'); +PS.push(buf->val); +``` + +Errors: + +**InvalidIdentifier** +**InvalidLevel** +**StackUnderflow** +**InvalidIndex** +**InvalidType** + +### 13.3.41 Get contents + +Short description: Set data contents to element of data of constructed type. + +Synopsis: **GETC Did1 Lvl** + +Operands: **Did1** shall be the two-byte representation of the data identifier of the data to access. +**Lvl** shall be a one-byte unsigned quantity representing the number of nested levels to go to access the element to access. + +Stack: ..., **Did2**, **Idx(Lvl)**, ..., **Idx(1)** ⇒ ..., + +Types: Not applicable. + +Parameters: **Idx(1)**, ... **Idx(Lvl)** shall be interpreted as of **unsigned short** type. + +Effect: Pop a list of indices and a data identifier **Did2** from the parameter stack. Within the constructed type data identified by **Did1**, assign the variable identified by **Did2** to the element addressed by the popped list of indices: +**VT(Did2).Val = DT(Did1)[Idx(1),...,Idx(Lvl)]** +Check that the element to access is of the same type as the data identified by **Did2**. + +Formal specification: + +``` + +void *buf = &DT(Did1); +unsigned short idx; +for (;Lvl>0; Lvl--;) +{ + if (buf->TID <= 'object reference') then raise('InvalidLevel'); + idx = PS.pop('unsigned short'); + if (buf->lg < idx) then raise ('InvalidIndex'); + buf = &buf->.val[idx]; +} +DID did2 = PS.pop('data identifier'); +if (VT(did2).TID != buf->TID) then raise('TypeMismatch'); +VT(did2).val = buf->val; + +``` + +Errors: + +- InvalidIdentifier** +- InvalidLevel** +- StackUnderflow** +- InvalidIndex** +- TypeMismatch** + +### 13.3.42 Set + +Short description: Set element of variable of constructed type to value. + +Synopsis: SET Did Lvl + +Operands: **Did** shall be the two-byte representation of the data identifier of the variable to modify. +**Lvl** shall be a one-byte unsigned quantity representing the number of nested levels to go to access the element to modify. + +Stack: ..., Val, Idx(Lvl), ..., Idx(1) ⇨ ..., + +Types: Not applicable. + +Parameters: **Idx(1), ... Idx(Lvl)** shall be interpreted as of **unsigned short** type. +**Val** shall be interpreted as of the same type as the element to modify. + +Effect: Pop a list of indices and a value from the parameter stack. Within the structured variable identified by **Did**, assign the element addressed by the popped list of indices to the popped value: +**VT(Did)[Idx(1),...,Idx(Lvl)] = Val** +Check that the element to modify is of a primitive type. If **Lvl** equals 0, perform as a **POP** instruction. + +Formal specification: + +``` + +void *buf = &VT(Did); +unsigned short idx; +for (;Lvl>0; Lvl--;) +{ + if (buf->TID <= 'object reference') then raise('InvalidLevel'); + idx = PS.pop('unsigned short'); + if (buf->lg < idx) then raise ('InvalidIndex'); + buf = &buf->.val[idx]; +} +if (buf->TID > 'object reference') then raise('InvalidType'); +buf->val = PS.pop(buf->TID); + +``` + +Errors:                   **Invalid Identifier** +                           **InvalidLevel** +                           **StackUnderflow** +                           **InvalidIndex** +                           **InvalidType** + +### 13.3.43 Set contents + +Short description:   Set element of variable of constructed type to data contents. + +Synopsis:            **SETC Did1 Lvl** + +Operands:           **Did1** shall be the two-byte representation of the data identifier of the variable to modify. +                       **Lvl** shall be a one-byte unsigned quantity representing the number of nested levels to go to access the element to modify. + +Stack:             ..., **Did2**, **Idx(Lvl)**, ..., **Idx(1)** ⇨ ..., + +Types:             Not applicable. + +Parameters:        **Idx(1)**, ... **Idx(Lvl)** shall be interpreted as of **unsigned short type**. +                       **Did2** shall be interpreted as of **data identifier type**. + +Effect:            Pop a list of indices and a data identifier from the parameter stack. Within the structured variable identified by **Did1**, assign the element addressed by the popped list of indices to the value identified by the popped data: +                       **VT(Did1)[Idx(1),...,Idx(Lvl)] = DT(Did2).** +                       Check that **Did2** identifies a data of the type of the element to modify. If **Lvl** equals 0, perform as a **POPC** instruction. + +Formal +specification:      **void \*buf = VT(Did1);** +                       **unsigned short idx;** +                       **for (;Lvl>0; Lvl--;)** +                       **{** +                           **if (buf->TID <= 'object reference') then raise('InvalidLevel');** +                           **idx = PS.pop('unsigned short');** +                           **if (buf->lg < idx) then raise ('InvalidIndex');** +                           **buf = &buf->.val[idx];** +                       **}** +                       **DID did2 = PS.pop('data identifier');** +                       **if (DT(did2).TID != buf->TID) then raise('TypeMismatch');** +                       **buf->val = DT(did2).val;** + +Errors:             **InvalidIdentifier** +                       **InvalidLevel** +                       **StackUnderflow** +                       **InvalidIndex** +                       **TypeMismatch** + +## 13.4 Type conversion rules + +This subclause defines the rules that shall apply when a **convert** (CVT) instruction is used to convert a parameter stack value (hence a value of a primitive type) from a source type to a destination type. + +Values of the **data identifier** and **object reference** types shall not be converted to or from a value of another type. + +As regards the other primitive types, not all type conversions are allowed; however, any of them can be converted to any other using sequences of conversions. + +Table 4 shows the allowed type conversions together with the number of the subclause in which they are defined: + +**Table 4/T.173 – Type conversions** + +| Source/Destination | O | S | L | W | U | F | D | B | C | +|--------------------|----------|----------|----------|----------|----------|----------|----------|--------|--------| +| O | N/A | 13.4.2.2 | N/A | 13.4.2.2 | N/A | N/A | N/A | 13.4.4 | N/A | +| S | N/A | N/A | 13.4.2.3 | 13.4.1 | 13.4.3 | N/A | N/A | 13.4.4 | N/A | +| L | N/A | 13.4.5 | N/A | N/A | 13.4.1 | 13.4.2.3 | N/A | 13.4.4 | N/A | +| W | 13.4.5 | 13.4.1 | 13.4.2.3 | N/A | 13.4.2.3 | N/A | N/A | 13.4.4 | 13.4.1 | +| U | N/A | N/A | 13.4.1 | 13.4.5 | N/A | 13.4.2.3 | N/A | 13.4.4 | N/A | +| F | N/A | N/A | 13.4.6 | N/A | 13.4.6 | N/A | 13.4.2.3 | N/A | N/A | +| D | N/A | N/A | N/A | N/A | N/A | 13.4.5 | N/A | N/A | N/A | +| B | 13.4.2.1 | 13.4.2.1 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | +| C | N/A | N/A | N/A | 13.4.1 | N/A | N/A | N/A | N/A | N/A | + +### 13.4.1 Reversible conversions + +The following conversions are lossless (i.e. preserve information) when reversed: + +- between **unsigned short** and **character** (WC, CW); +- between **short** and **unsigned short** (SW, WS); +- between **long** and **unsigned long** (LU, UL). + +For all these conversions, the result of the conversion shall be the value of the target type that has the same complement-to-two notation as the source value. + +### 13.4.2 Lossless extensions + +The following conversions extend the source value in a lossless fashion: + +- from **boolean** (BO, BS) (see 13.4.2.1); +- from **octet** to a numeric type (OS, OW) (see 13.4.2.2); +- from a signed numeric type to a signed numeric type with a larger range (SL, LF, FD) (see 13.4.2.3); +- from an unsigned numeric type to any numeric type with a larger range (WL, WU, UF) (see 13.4.2.3). + +#### 13.4.2.1 Conversions from boolean + +If the value of the source **boolean** is false, the value in the destination type shall be 0. + +If the value of the source **boolean** is true, the value in the destination type shall be the value which corresponds to all bits set at 1 (in complement-to-two notation), i.e.: + +- 255 for an **octet** destination type; +- –1 for a **short** destination type. + +#### **13.4.2.2 Conversions from octet to a numeric type** + +The value in the destination type shall be the octet value. + +#### **13.4.2.3 Lossless conversions from a numeric to a larger numeric type** + +The value in the destination type shall be the same numeric value as the value in the source type. + +#### **13.4.3 Lossy extensions** + +The conversion from **short** to **unsigned long** (SU) shall perform as follows: + +- if the source value is positive or null, the destination value shall be the same numeric value as the source value; +- if the source value is strictly negative, the destination value is unspecified. + +#### **13.4.4 Truncations to boolean** + +Truncations from an **octet** or numeric type to **boolean** (OB, SB, WB, LB, UB) shall perform as follows: + +- if the source value is 0, the destination value shall be "false"; +- if the source value is different from 0, the destination value shall be "true". + +#### **13.4.5 Truncations between integer or between floating-point types** + +Truncations from an integer type to an **octet** or integer type (WO, LS, UW) or from a floating-point type to another floating-point type (DF) shall perform as follows: + +- if the source value is within the range of the destination type, then the destination value shall be the same numeric value as the source value; +- otherwise, the destination value is unspecified. + +#### **13.4.6 Truncations from floating-point to integer** + +Truncations from a floating-point type to an integer type (FL, FU) shall perform as follows: + +- first the decimal part of the source value shall be truncated to an integer value (rounding down); +- then the rules defined in 13.4.5 shall apply to the truncated value. + +### **14 IDL mapping to MHEG-SIR** + +This clause specifies how an IDL specification shall be mapped to the declarations of an interchanged script, when this IDL specification is intended for use by the script as an external service provider. + +This clause defines the mapping to MHEG-SIR declarations for: + +- IDL interfaces and modules; +- IDL types; +- IDL constants; + +- references to IDL objects; +- IDL operations; +- IDL attributes; +- IDL exceptions. + +### 14.1 IDL specifications + +An IDL specification shall be mapped to an MHEG-SIR **PackageDeclaration** declared as a component of an **external-package-declarations** component of the **InterchangedScript**. The name of the IDL specification shall be mapped to the **name** component of this package declaration. + +NOTE – Examples of IDL specifications are MHEG API, MPEG/DSM-CC. + +If the number of operations or exceptions of an IDL specification exceed the size of a package, the specification shall be split into several packages sharing the same name, but having different MHEG-SIR identifiers. + +### 14.2 IDL interfaces and modules + +As the package declaration is a "flat" organization, there is neither a mapping for an IDL module nor for an IDL interface. However, a reference to the embedding interface (i.e. a parameter of type **Object**) shall be provided as an implicit parameter to each invocation of function describing an IDL operation. + +### 14.3 IDL operations + +An IDL operation shall be mapped to an MHEG-SIR **services** component of the package declaration that maps the IDL specification to which the operation belongs. + +#### 14.3.1 Operation name + +The global name for an IDL operation shall be mapped to the MHEG-SIR **name** component of this service description. + +#### 14.3.2 Operation parameters + +The parameters of an IDL operation shall be mapped to the **parameters-description** component of the service description. In a **ServiceParameterDescription**, each IDL parameter type shall be mapped to the **type** component which identifies a type declared according to the type mapping rules defined in this clause. The IDL passing mode for a parameter shall be mapped to the **passing-mode** component of the corresponding MHEG-SIR service parameter description. + +If the operation has neither an output parameter nor a return value and is specifically designed to return several exceptions in sequence (e.g. for notification purposes), the value of its **calling-mode** component should be "asynchronous". Otherwise, the value of the **calling-mode** component shall be "synchronous". + +If a semantically synchronous operation is intended to raise several exceptions in sequence, it should be split into two MHEG-SIR operations: a **synchronous** one and an **asynchronous** one. + +#### 14.3.3 Implicit parameter + +When an IDL operation is mapped to an MHEG-SIR service description, the object instance to which the operation applies shall remain an implicit parameter, i.e. it shall not be expressed as part of the signature of the service. + +NOTE – However, upon invoking the operation, this parameter is provided as the leading actual parameter as if its **type** were "object reference" and its **passing-mode** were "in". + +#### 14.3.4 Return value + +The return value type of an IDL operation shall be mapped to the **return-value-type** component of the service description. + +### 14.4 IDL attributes + +An IDL attribute shall be mapped to two service descriptions within a package declaration: one accessor service, whose function is to get the value of the attribute, and one modifier service, whose function is to set the value of the attribute. + +#### 14.4.1 Accessor + +As concerns the accessor service, the global IDL attribute name whose final identifier is prefixed with "get\_" shall be mapped to the MHEG-SIR **name** component of the service description. An accessor service shall have no explicit parameter. The IDL attribute type shall be mapped to the **return-value-type** component of the service description. + +Example: In the MHEG-3 API, the **routine\_id** attribute of the **RoutineInvocation** object shall be mapped to the IDL global name **MHEG\_3::RoutineInvocation::get\_RoutineId** + +#### 14.4.2 Modifier + +As concerns the modifier service, the global IDL attribute name whose final identifier is prefixed with "set\_" shall be mapped to the MHEG-SIR **name** component of the service description. A modifier service shall have one parameter with **in** passing mode and such that the IDL attribute type shall be mapped to the **type** component of the parameters description for this service. A modifier service shall have no return value. + +#### 14.4.3 Readonly attribute + +If an IDL attribute is defined as **readonly**, only the accessor service shall be provided as part of the package declaration. + +### 14.5 IDL inherited operations + +Inherited IDL operations shall be mapped as if they were defined in the specific interface. + +### 14.6 IDL exceptions + +An IDL exception shall be mapped to an MHEG-SIR **exception-description** component of the package declaration that maps the IDL specification to which the exception belongs. + +#### 14.6.1 Exception name + +The IDL global name of the exception shall be mapped to the MHEG-SIR **name** component of this exception description. + +#### 14.6.2 Exception members + +Members of an IDL exception shall be mapped to the **parameters-description** component of this exception description. In this parameters description, each IDL member type shall be mapped to the **type** component which identifies a type declared according to the type mapping rules defined in this clause. + +### 14.6.3 Implicit member + +When an IDL exception is mapped to an MHEG-SIR exception description, the object instance from which the exception originates shall remain an implicit member, i.e. shall not be expressed as part of the signature of the exception. + +NOTE – However, upon raising the exception, this member is provided as the leading actual member as if its **type** were "object reference". + +## 14.7 IDL types + +An IDL type shall be mapped to an MHEG-SIR **TypeDeclaration** declared as a component of the **type-declarations** component of the **InterchangedScript**. A type declaration shall have a global scope in the interchanged script. + +IDL basic types and constructors shall be mapped to MHEG-SIR primitive types and constructors as summarized in Table 5: + +**Table 5/T.173 – Type mapping** + +| IDL | MHEG-SIR | +|----------------|-----------------------------| +| void | void | +| octet | octet | +| short | short | +| unsigned short | unsigned short | +| long | long | +| unsigned long | unsigned long | +| float | float | +| double | double | +| boolean | boolean | +| char | character | +| enum | unsigned long | +| string | string | +| sequence | sequence | +| array | array | +| struct | structure | +| union | union | +| (object) | object reference | +| any | data identifier (see below) | + +### 14.7.1 char type + +Mapping IDL **char** types to MHEG-SIR **character** types shall involve transcoding values from ISO 8859-1 to ISO/IEC 10646-1. + +### 14.7.2 enum type + +The range checking of **enum** values need not be preserved. + +### 14.7.3 Constructed types + +An IDL type definition shall be mapped to an MHEG-SIR **TypeDescription**. If the IDL type is a basic type or if it has already been the subject of another type declaration, this type description shall + +consist of a type identifier. Otherwise, it shall be constructed according to the following mapping rules: + +- an IDL **struct** field shall be mapped to its rank in the MHEG-SIR **structure** description; its name shall not be preserved; +- an IDL **union** tag value shall be mapped to its rank in the MHEG-SIR **union** description; its name and value shall not be otherwise preserved; +- a multidimensional IDL **array** shall be mapped to an MHEG-SIR **array** whose element type is **array**. + +#### 14.7.4 any type + +The IDL **any** type shall be mapped to MHEG-SIR **data identifier** provided that the **any** type is used with an associated key to determine the actual type: + +``` +struct { Key the_key; any value } +``` + +where **Key** is a **string**, **numeric** or **enum** type whose value completely determines the type of the **value** field. + +The above IDL type shall be mapped to an MHEG-SIR **structure** of two elements: + +- an **unsigned short** representing a valid TID within the script, to map the key; +- a **data identifier** representing a variable of the type identified by the first element and which holds the value. + +Any other use of the **any** type is not guaranteed to have its semantics preserved when mapped to MHEG-SIR. + +#### 14.7.5 Restrictions on types + +If two IDL constructed types have the same structure, they shall be mapped to a single MHEG-SIR type. + +### 14.8 IDL constants + +IDL constants shall be mapped to an MHEG-SIR **ConstantDeclaration** declared as a component of the **constant-declarations** component of the **InterchangedScript**. A constant declaration shall have a global scope in the interchanged script. + +## 15 The MHEG-3 API + +This clause specifies the syntax and semantics of the MHEG-3 API. + +Interchanged scripts shall use the MHEG-3 API according to the IDL interface syntax defined in this clause and in Annex F. + +MHEG-SIR script interpreters shall provide the MHEG-3 API according to the IDL interface syntax defined in this clause and in Annex F, with the semantics defined in this clause. The invocation of the operations shall have the effect specified in this clause. + +All MHEG-SIR predefined functions that map MHEG-3 API operations shall be **synchronous**. + +The MHEG-3 API definition consists of a unique IDL module called **MHEG\_3**. This module defines predefined types, three exceptions and four object interfaces; there is no inheritance relationship among the four objects. + +## 15.1 ScriptInterpreter object + +The **ScriptInterpreter** object represents the script interpreter. It shall be unique. It is used as a factory for **MhScript** objects. + +To invoke operations on the **ScriptInterpreter** object, interchanged scripts shall use "null" as the value of the implicit object reference parameter. + +### 15.1.1 kill operation + +#### Synopsis + +Interface:       **ScriptInterpreter** +Operation:       **kill** +Result:           **void** + +#### Description + +The **kill** operation is used to kill the **ScriptInterpreter** object and terminate the script interpreter process. + +When the operation is invoked, the main process shall invoke a **destroy** operation on all available **MhScript** objects then terminate the script interpreter process. + +Unlike the other MHEG-3 API operations, this operation is not an MHEG-SIR predefined function. Therefore, it shall not be available for use by MHEG-SIR interchanged scripts. + +### 15.1.2 prepare operation + +#### Synopsis + +Interface:       **ScriptInterpreter** +Operation:       **prepare** +Result:           **MhScript** +In:               **ContentReference**                               **content\_reference** +Exception:       **InvalidParameter** +Exception:       **InvalidScript** +Exception:       **OperationFailed** + +#### Description + +The **prepare** operation is used to create an **MhScript** object from an interchanged script and request the script interpreter to initialize that mh-script. + +The **content\_reference** parameter specifies the location of the interchanged script. It consists of two strings: a public identifier and a system identifier. If any one of these strings is null, it shall be ignored. At least one of both string field values shall be non-null. + +When the operation is invoked, the main process shall perform the mh-script initialization operations as specified by 9.5.2. As soon as this has been achieved, the status of the mh-script shall become **available**. + +The result of the operation shall be an object reference to the created **MhScript**. + +The **InvalidParameter** exception shall be raised if the **content\_reference** parameter does not allow to access an interchanged script. Then the **rank** member shall be 1. + +The **InvalidScript** exception shall be raised if an illegal statement is detected during parsing of the interchanged script. Then the **the\_entity** member shall represent the type of the first entity in the declarations part on which an error has been detected, whereas the **identifier** member shall represent the identifier of this entity as follows: + +- a TID for a type declaration; +- a DID for a constant declaration or a variable declaration; +- a FID for a service declaration or a routine declaration; +- a MID for an exception declaration or a handler declaration; +- a PID for a package declaration. + +The **OperationFailed** exception shall be raised if the mh-script initialization operations cannot be completed although no error has been detected in the syntax of the interchanged script. + +Whenever an exception is raised, the **MhScript** object shall not be created and the status of the mh-script shall remain **not available**. + +## 15.2 MhScript object + +The **MhScript** object represents an available mh-script. It is used as a factory for **RtScript** objects. + +### 15.2.1 destroy operation + +#### Synopsis + +Interface: **MhScript** + +Operation: **destroy** + +Result: **void** + +#### Description + +The **destroy** operation is used to kill the **MhScript** object and destroy the corresponding mh-script. + +When the operation is invoked, the main process shall perform the following steps in the specified order: + +- put the target mh-script to **not available** status; +- invoke a **delete** operation on all existing **RtScript** objects that have been created by this mh-script; +- perform the **package unload** procedure for all packages; +- release all the mh-script memory areas attached to the mh-script. + +### 15.2.2 new operation + +#### Synopsis + +Interface: **MhScript** + +Operation: **new** + +Result: **RtScript** + +Exception: **OperationFailed** + +#### Description + +The **new** operation is used to create an **RtScript** object from the mh-script and request the script interpreter to initialize that rt-script. + +When the operation is invoked, the main process shall perform the rt-script initialization operations as specified by 9.5.3. After successful initialization, the status of the rt-script shall become **ready**. + +The result of the operation shall be an object reference to the created **RtScript**. + +The **OperationFailed** exception shall be raised if the rt-script initialization operations cannot be completed. Then the **RtScript** object shall not be created and the status of the rt-script shall remain **not ready**. + +### 15.3 RtScript object + +The **RtScript** object represents an rt-script whose status is **ready**, **running** or **erroneous**. It is used as a factory for **RoutineInvocation** objects. + +#### 15.3.1 delete operation + +##### Synopsis + +Interface: **RtScript** + +Operation: **delete** + +Result: **void** + +##### Description + +The **delete** operation is used to kill the **RtScript** object and destroy the corresponding rt-script. + +When the operation is invoked, the main process shall perform the following steps in the specified order: + +- put the target rt-script to **not ready** status; +- invoke a **close** operation on all **RoutineInvocation** objects that have been created by the rt-script; +- terminate all processing units; +- release all rt-script memory areas attached to the rt-script. + +#### 15.3.2 setPriority operation + +##### Synopsis + +Interface: **RtScript** + +Operation: **setPriority** + +Result: **void** + +In: **unsigned short** **priority** + +##### Description + +The **setPriority** operation is used to modify the scheduling priority associated with the rt-script. + +The **priority** parameter specifies the new priority value. + +When the operation is invoked, the main process may modify its scheduling policy accordingly. The precise effect of this operation is not specified by this Recommendation. Depending on the implementation, it may have no effect. However, the execution unit of an rt-script with a lower priority value than another rt-script shall not be given more CPU time than the execution unit of the latter. + +### 15.3.3 getPriority operation + +#### Synopsis + +Interface:       **RtScript** +Operation:       **getPriority** +Result:           **unsigned short** + +#### Description + +The **getPriority** operation is used to retrieve the current value of the scheduling priority associated with the rt-script. If no priority has been explicitly set to this rt-script, the default value specified by the script interpreter shall be used. + +### 15.3.4 setData operation + +#### Synopsis + +Interface:       **RtScript** +Operation:       **setData** +Result:           **void** +In:               **DID**                               **variable\_id** +In:               **any**                               **variable\_value** +Exception:       **InvalidParameter** +Exception:       **OperationFailed** + +#### Description + +The **setData** operation is used to assign a value to a global or dynamic variable of the rt-script. + +The **variable\_id** parameter specifies the data identifier of the data to modify. + +The **variable\_value** parameter specifies the value to assign to the variable. The type of the actual parameter is determined by the type of the variable. + +When the operation is invoked, the main process shall request the rt-script execution unit to assign the target variable to the provided value. + +The **InvalidParameter** exception shall be raised: + +- if the **variable\_id** parameter references a constant, a local variable or a non-existing constant or variable. Then the **rank** member shall be 1; +- if the **variable\_value** parameter is not of an IDL type that matches the MHEG-SIR type of the target variable. Then the **rank** member shall be 2. + +The **OperationFailed** exception shall be raised if the status of the rt-script is **running** or **erroneous**. + +### 15.3.5 getData operation + +#### Synopsis + +Interface:       **RtScript** +Operation:       **getData** +Result:           **any** +In:               **DID**                               **data\_id** +Exception:       **InvalidParameter** +Exception:       **OperationFailed** + +## Description + +The **getData** operation is used to retrieve the current value of a constant or variable. + +The **data\_id** parameter specifies the data identifier of the data to access. + +When the operation is invoked, the rt-script execution unit shall return the current value of the constant or variable. + +The result of the operation shall be the requested value and shall be of an IDL type that matches the MHEG-SIR type of the target constant or variable. + +The **InvalidParameter** exception shall be raised if the **data\_id** parameter references a non-existing constant or variable. Then the **rank** member shall be 1. + +The **OperationFailed** exception shall be raised if the status of the rt-script is **running** or **erroneous**. + +### 15.3.6 allocate operation + +#### Synopsis + +| | | +|------------|------------------------------------| +| Interface: | RtScript | +| Operation: | allocate | +| Result: | DID | +| In: | TID variable_type_id | +| Exception: | InvalidParameter | +| Exception: | OperationFailed | + +#### Description + +The **allocate** operation is used to create a dynamic variable of a given type within the rt-script. + +The **variable\_type\_id** parameter specifies the MHEG-SIR type identifier of the target variable, as declared within the rt-script. + +When the operation is invoked, the rt-script execution unit shall perform as if it would execute an **ALLOC** instruction with **variable\_type\_id** as operand, i.e. it shall reserve appropriate heap memory, generate a new DID and return it. + +The result of the operation shall be the data identifier of the new dynamic variable. + +The **InvalidParameter** exception shall be raised if the value of the **variable\_type\_id** parameter is neither a predefined type nor a type declared within the rt-script. Then the **rank** member shall be 1. + +The **OperationFailed** exception shall be raised wherever the **ALLOC** instruction would raise an error. Then the variable shall not be allocated and the error register shall not be modified. + +### 15.3.7 free operation + +#### Synopsis + +| | | +|------------|-------------------------------| +| Interface: | RtScript | +| Operation: | free | +| Result: | void | +| In: | DID variable_id | +| Exception: | InvalidParameter | + +## Description + +The **free** operation is used to destroy a dynamic variable of the rt-script. + +The **variable\_id** parameter specifies the data identifier of the variable to be released. + +When the operation is invoked, the rt-script execution unit shall perform as if it would execute a **FREE** instruction with **variable\_id** as parameter, i.e. it shall release the dynamic variable and make its identifier invalid. + +The **InvalidParameter** exception shall be raised if the **variable\_id** parameter does not refer to an existing dynamic variable previously allocated through the MHEG-3 API. Then the **rank** member shall be 1. + +NOTE – A script interpreter may use a data identifier allocation policy that allows to distinguish easily variables allocated through the MHEG-3 API from variables allocated using an instruction, for instance by the range to which their data identifier belongs. + +### 15.3.8 stop operation + +#### Synopsis + +Interface:       **RtScript** +Operation:       **stop** +Result:           **void** +Exception:       **OperationFailed** + +#### Description + +The **stop** operation is used to put the rt-script back into ready status. + +When the operation is invoked, the script interpreter shall request the rt-script execution unit to stop, flush the calling stack, message queue and parameter stack and reset all registers. It shall then put the rt-script to **ready** status. Unlike the **reInit** operation, the global and dynamic variables shall not be changed. + +The **OperationFailed** exception shall be raised if the operation could not be performed successfully, for instance if the rt-script memory areas have been corrupted due to an execution error. + +### 15.3.9 reInit operation + +#### Synopsis + +Interface:       **RtScript** +Operation:       **reInit** +Result:           **void** +Exception:       **OperationFailed** + +#### Description + +The **reInit** operation is used to put the rt-script back into its initial state, i.e. just after initialization. + +When the operation is invoked, the script interpreter shall: + +- terminate the rt-script execution unit; +- release all dynamic variables; +- set the global variables back to their initial values (as in the mh-script global variable definition table); +- flush the parameter stack, the message queue and the calling stack, releasing local variable tables; + +- reset all registers; +- finally, put the rt-script to **ready** status. + +The **OperationFailed** exception shall be raised if the operation could not be performed successfully, for instance if the rt-script memory areas have been corrupted due to an execution error. + +### 15.3.10 getRtScriptStatus operation + +#### Synopsis + +Interface: **RtScript** + Operation: **getRtScriptStatus** + Result: **RtScriptStatus** + +#### Description + +The **getRtScriptStatus** operation is used to retrieve the current status of the rt-script. + +The result of the operation shall be one of the following: **READY**, **RUNNING** or **ERRONEOUS**. + +### 15.3.11 open operation + +#### Synopsis + +Interface: **RtScript** + Operation: **open** + Result: **RoutineInvocation** + In: **FID** **routine\_id** + Exception: **InvalidParameter** + +#### Description + +The **open** operation is used to create an **RoutineInvocation** object from the rt-script. + +The **routine\_id** parameter specifies the function identifier of the routine with which the new **RoutineInvocation** object is associated. + +The script interpreter may opt for either of the following policies: + +- to retrieve the signature of the target routine when the **open** operation is invoked, so as to check the validity of the passed parameters "on the fly", i.e. as soon as a **setParameter** operation is invoked; +- to check the validity of parameters only upon invocation of the **run** operation. + +The result of the operation shall be an object reference to the created **RoutineInvocation**. + +The **InvalidParameter** exception shall be raised if the **routine\_id** parameter does not identify a valid routine of the rt-script. In this case, the **rank** member shall be 1. + +## 15.4 RoutineInvocation object + +The **RoutineInvocation** object represents an invocation context of a routine. This invocation context is used to pass parameters to and to request execution of a given routine of the rt-script. + +### 15.4.1 close operation + +#### Synopsis + +Interface: **RoutineInvocation** + Operation: **close** + + + +- if the operation's **rank** parameter exceeds the number of the last parameter of the routine. Then the exception's **rank** member shall be 1; +- if the **parameter\_type\_id** parameter does not correspond to the type of parameter in the routine's signature. Then the exception's **rank** member shall be 2; +- if the **parameter\_value** parameter is not of an appropriate type, i.e. an IDL type that matches the type described by the **parameter\_type\_id** parameter, when the passing mode is by **value**, and a DID type when the passing mode is by **reference**. Then the exception's **rank** member shall be 3; +- when the passing mode is by reference, if the **parameter\_value** parameter is a DID that does not identify an existing global or dynamic variable whose type matches the parameter type defined by the routine's signature. Then the exception's **rank** member shall be 3. + +#### 15.4.4 getPrototype operation + +##### Synopsis + +Interface:       **RoutineInvocation** + Operation:       **getPrototype** + Result:           **Prototype** + +##### Description + +The **getPrototype** operation is used to retrieve the signature of the routine. + +When the operation is invoked, the script interpreter shall return the signature of the routine. + +The result of the operation shall be a description of the routine signature: + +- a) the **return\_value\_type** field shall be set to RT[routine\_id].TID; +- b) the nth item of the signature field shall correspond to RT[routine\_id].sig[n]: + - 1) the **passing\_mode** field shall be set to **BY\_VALUE**, or **BY\_REFERENCE** respectively, when RT[routine\_id].sig[n].mod is 'value', 'reference' respectively; + - 2) the **parameter\_type\_id** field shall be set to RT[routine\_id].sig[n].TID. + +#### 15.4.5 run operation + +##### Synopsis + +Interface:       **RoutineInvocation** + Operation:       **run** + Result:           **void** + Exception:       **OperationFailed** + +##### Description + +The **run** operation is used to request the execution of the routine with the parameter values previously provided using the **setParameter** operation. + +When the operation is invoked, the main process shall: + +- create a message whose message identifier is the index of the routine (i.e. the value of the **routine\_id** attribute) and whose parameters are the parameters set by the preceding **setParameter** operations; +- insert this message into the message queue of the target rt-script; +- if the current status of the rt-script is **ready**, put it to **running**. + +If the script interpreter opts for policy b) defined in 15.3.11, it shall check the validity, with regard to the routine's signature, of all the type identifiers and values of the parameters previously provided using the **setParameter** operation. + +The **OperationFailed** exception shall be raised if any of the provided parameters does not map the routine's signature. + +#### 15.4.6 reset operation + +##### Synopsis + +Interface:       **RoutineInvocation** +Operation:       **reset** +Result:           **void** + +##### Description + +The **reset** operation is used to clear the routine invocation context to prepare a new invocation. + +When the operation is invoked, the parameters previously buffered as the result of a **setParameter** operation shall be cleared. + +NOTE – Using this operation after each **run** avoids any risk of collision. Not using it allows to repeat the same invocation without supplying the parameters again. + +#### 15.4.7 getInvocationStatus operation + +##### Synopsis + +Interface:       **RoutineInvocation** +Operation:       **getInvocationStatus** +Result:           **InvocationStatus** + +##### Description + +The **getInvocationStatus** operation is used to retrieve the current routine invocation status. + +The result of the operation shall be one of the following values: + +- **NOT\_STARTED**: no **run** operation has been invoked since the creation of the object or since the last **reset** operation; +- **PROCESSING**: a **run** operation has been invoked but the routine execution has not been completed by the rt-script execution unit (either the request is in the message queue or the routine is currently under execution); +- **TERMINATED**: the routine execution triggered by the last invoked **run** operation has been completed by the rt-script execution unit; +- **ABORTED**: the routine execution triggered by the last invoked **run** operation has resulted in an instruction execution error. + +## ANNEX A + +### ASN.1 specification of interchanged scripts + +This Annex specifies the ASN.1 notation, according to ITU-T Rec. X.680 | ISO/IEC 8824-1 [1], for the syntax of the "script data" component of the MHEG "script" class. + +Interchanged scripts shall have the syntax defined by the ASN.1 **ISOMHEG-sir** module. + +-- Module: MHEG-SIR (sir)-- + +-- + +-- Copyright statement: + +-- ----- + +-- (c) ITU, 1996. + +-- Permission to copy in any form is granted for use with conforming to +-- MHEG-3 engines and applications as defined by this Recommendation +-- provided this notice is included in all copies. + +**ISOMHEG-sir {joint-iso-itu-t (2) mheg (19) version (1) script-interchange-representation (11)}** +**DEFINITIONS IMPLICIT TAGS ::= BEGIN** + +**EXPORTS InterchangedScript;** + +**InterchangedScript ::= SEQUENCE** + +{ +    **type-declarations**                      **SEQUENCE (SIZE (1.. max-nb-declared-types)) OF** +                                            **TypeDeclaration OPTIONAL,** +    **constant-declarations**                **[0] SEQUENCE (SIZE (1 .. max-nb-constants)) OF** +                                            **ConstantDeclaration OPTIONAL,** +    **global-variable-declarations**        **[1] SEQUENCE (SIZE (1 .. max-nb-global-variables)) OF** +                                            **VariableDeclaration OPTIONAL,** +    **external-package-declarations**       **[2] SEQUENCE (SIZE (1 .. max-nb-packages)) OF** +                                            **PackageDeclaration OPTIONAL,** +    **handler-declarations**                **[3] SEQUENCE (SIZE (1 .. max-nb-messages)) OF** +                                            **HandlerDeclaration OPTIONAL,** +    **routine-declarations**                **[4] SEQUENCE (SIZE (1 .. max-nb-routines)) OF** +                                            **RoutineDeclaration OPTIONAL** +} + +**TypeDeclaration ::= SEQUENCE** + +{ +    **identifier**                            **[0] TypeIdentifier OPTIONAL,** +    **description**                         **TypeDescription** +} + +**TypeDescription ::= CHOICE** + +{ +    **string-description**                  **[1] INTEGER (0..max-size-string) OPTIONAL,** +    **sequence-description**                **[2] SequenceDescription,** +    **array-description**                   **[3] ArrayDescription,** +    **structure-description**               **[4] StructureDescription,** +    **union-description**                   **[5] UnionDescription** +} + +**SequenceDescription ::= SEQUENCE** + +{ +    **bound**                                **INTEGER (0 .. max-size-sequence),** +    **element-type**                        **TypeIdentifier** +} + +**ArrayDescription ::= SEQUENCE** + +{ +    **size**                                 **INTEGER (1 .. max-size-array),** +    **element-type**                        **TypeIdentifier** +} + +**UnionDescription ::= SEQUENCE (SIZE (1 .. max-size-union)) OF TypeIdentifier** + +**StructureDescription ::= SEQUENCE (SIZE (1 .. max-size-structure)) OF TypeIdentifier** + +``` + +ConstantDeclaration ::= SEQUENCE +{ + identifier [0] DataIdentifier OPTIONAL, + type TypeIdentifier ALL EXCEPT 0, + value ConstantValue +} +ConstantValue ::= CHOICE +{ + octet [1] OctetValue, + short [2] ShortValue, + long [3] LongValue, + unsigned-short [4] UnsignedShortValue, + unsigned-long [5] UnsignedLongValue, + float [6] FloatValue, + double [7] DoubleValue, + boolean [8] BooleanValue, + character [9] CharacterValue, + data-identifier [10] DataIdentifier (0..Instruction mnemonics | Op-code (binary) | Opcode (hexa) | Op1 length | Op1 encoding | Op2 length | Op2 encoding | +|------------------------------|-------------------------|----------------------|-------------------|---------------------|-------------------|---------------------| +| NOP | 0000 0000 | 00 | 0 | | | | +| YIELD | 0000 0010 | 02 | 0 | | | | +| RET | 0000 0011 | 03 | 0 | | | | +| FREE | 0000 1000 | 08 | 0 | | | | +| NOT_B | 0001 0000 | 10 | 0 | | | | +| NOT_O | 0001 0001 | 11 | 0 | | | | +| NOT_W | 0001 0010 | 12 | 0 | | | | +| NOT_U | 0001 0011 | 13 | 0 | | | | +| OR_B | 0001 0100 | 14 | 0 | | | | +| OR_O | 0001 0101 | 15 | 0 | | | | +| OR_W | 0001 0110 | 16 | 0 | | | | +| OR_U | 0001 0111 | 17 | 0 | | | | +| XOR_B | 0001 1000 | 18 | 0 | | | | +| XOR_O | 0001 1001 | 19 | 0 | | | | +| XOR_W | 0001 1010 | 1A | 0 | | | | +| XOR_U | 0001 1011 | 1B | 0 | | | | +| AND_B | 0001 1100 | 1C | 0 | | | | +| AND_O | 0001 1101 | 1D | 0 | | | | +| AND_W | 0001 1110 | 1E | 0 | | | | +| AND_U | 0001 1111 | 1F | 0 | | | | +| EQR | 0010 0000 | 20 | 0 | | | | +| EQ_O | 0010 0001 | 21 | 0 | | | | +| EQ_S | 0010 0010 | 22 | 0 | | | | +| EQ_L | 0010 0011 | 23 | 0 | | | | +| EQ_W | 0010 0100 | 24 | 0 | | | | +| EQ_U | 0010 0101 | 25 | 0 | | | | +| EQ_F | 0010 0110 | 26 | 0 | | | | +| EQ_D | 0010 0111 | 27 | 0 | | | | +| EQ_B | 0010 1000 | 28 | 0 | | | | +| EQ_C | 0010 1001 | 29 | 0 | | | | +| EQ_I | 0010 1010 | 2A | 0 | | | | +| EQ_R | 0010 1011 | 2B | 0 | | | | +| LT_C | 0011 0000 | 30 | 0 | | | | +| LT_O | 0011 0001 | 31 | 0 | | | | +| LT_S | 0011 0010 | 32 | 0 | | | | +| LT_L | 0011 0011 | 33 | 0 | | | | +| LT_W | 0011 0100 | 34 | 0 | | | | +| LT_U | 0011 0101 | 35 | 0 | | | | +| LT_F | 0011 0110 | 36 | 0 | | | | +| LT_D | 0011 0111 | 37 | 0 | | | | + +**Table B.1/T.173 – Encoding of MHEG-SIR instructions** *(continued)* + +| Instruction mnemonics | Op-code (binary) | Opcode (hexa) | Op1 length | Op1 encoding | Op2 length | Op2 encoding | +|------------------------------|-------------------------|----------------------|-------------------|---------------------|-------------------|---------------------| +| GT_C | 0011 1000 | 38 | 0 | | | | +| GT_O | 0011 1001 | 39 | 0 | | | | +| GT_S | 0011 1010 | 3A | 0 | | | | +| GT_L | 0011 1011 | 3B | 0 | | | | +| GT_W | 0011 1100 | 3C | 0 | | | | +| GT_U | 0011 1101 | 3D | 0 | | | | +| GT_F | 0011 1110 | 3E | 0 | | | | +| GT_D | 0011 1111 | 3F | 0 | | | | +| ADD_O | 0100 0001 | 41 | 0 | | | | +| ADD_S | 0100 0010 | 42 | 0 | | | | +| ADD_L | 0100 0011 | 43 | 0 | | | | +| ADD_W | 0100 0100 | 44 | 0 | | | | +| ADD_U | 0100 0101 | 45 | 0 | | | | +| ADD_F | 0100 0110 | 46 | 0 | | | | +| ADD_D | 0100 0111 | 47 | 0 | | | | +| SUB_O | 0100 1001 | 49 | 0 | | | | +| SUB_S | 0100 1010 | 4A | 0 | | | | +| SUB_L | 0100 1011 | 4B | 0 | | | | +| SUB_W | 0100 1100 | 4C | 0 | | | | +| SUB_U | 0100 1101 | 4D | 0 | | | | +| SUB_F | 0100 1110 | 4E | 0 | | | | +| SUB_D | 0100 1111 | 4F | 0 | | | | +| MUL_O | 0101 0001 | 51 | 0 | | | | +| MUL_S | 0101 0010 | 52 | 0 | | | | +| MUL_L | 0101 0011 | 53 | 0 | | | | +| MUL_W | 0101 0100 | 54 | 0 | | | | +| MUL_U | 0101 0101 | 55 | 0 | | | | +| MUL_F | 0101 0110 | 56 | 0 | | | | +| MUL_D | 0101 0111 | 57 | 0 | | | | +| DIV_O | 0101 1001 | 59 | 0 | | | | +| DIV_S | 0101 1010 | 5A | 0 | | | | +| DIV_L | 0101 1011 | 5B | 0 | | | | +| DIV_W | 0101 1100 | 5C | 0 | | | | +| DIV_U | 0101 1101 | 5D | 0 | | | | +| DIV_F | 0101 1110 | 5E | 0 | | | | +| DIV_D | 0101 1111 | 5F | 0 | | | | +| NEG_S | 0110 0010 | 62 | 0 | | | | +| NEG_L | 0110 0011 | 63 | 0 | | | | +| NEG_F | 0110 0110 | 66 | 0 | | | | +| NEG_D | 0110 0111 | 67 | 0 | | | | + +**Table B.1/T.173 – Encoding of MHEG-SIR instructions** *(continued)* + +| Instruction mnemonics | Op-code (binary) | Opcode (hexa) | Op1 length | Op1 encoding | Op2 length | Op2 encoding | +|------------------------------|-------------------------|----------------------|-------------------|---------------------|-------------------|---------------------| +| REM_O | 0111 1001 | 79 | 0 | | | | +| REM_S | 0111 1010 | 7A | 0 | | | | +| REM_L | 0111 1011 | 7B | 0 | | | | +| REM_W | 0111 1100 | 7C | 0 | | | | +| REM_U | 0111 1101 | 7D | 0 | | | | +| DUP_O | 1000 0001 | 81 | 0 | | | | +| DUP_S | 1000 0010 | 82 | 0 | | | | +| DUP_L | 1000 0011 | 83 | 0 | | | | +| DUP_W | 1000 0100 | 84 | 0 | | | | +| DUP_U | 1000 0101 | 85 | 0 | | | | +| DUP_F | 1000 0110 | 86 | 0 | | | | +| DUP_D | 1000 0111 | 87 | 0 | | | | +| DUP_B | 1000 1000 | 88 | 0 | | | | +| DUP_C | 1000 1001 | 89 | 0 | | | | +| DUP_I | 1000 1010 | 8A | 0 | | | | +| DUP_R | 1000 1011 | 8B | 0 | | | | +| CVT_SW | 1001 0100 | 94 | 0 | | | | +| CVT_WS | 1001 0101 | 95 | 0 | | | | +| CVT_LU | 1001 0110 | 96 | 0 | | | | +| CVT_UL | 1001 0111 | 97 | 0 | | | | +| CVT_CW | 1001 1010 | 9A | 0 | | | | +| CVT_WC | 1001 1011 | 9B | 0 | | | | +| CVT_BS | 1010 0000 | A0 | 0 | | | | +| CVT_OS | 1010 0001 | A1 | 0 | | | | +| CVT_SL | 1010 0010 | A2 | 0 | | | | +| CVT_LF | 1010 0011 | A3 | 0 | | | | +| CVT_WL | 1010 0100 | A4 | 0 | | | | +| CVT_UF | 1010 0101 | A5 | 0 | | | | +| CVT_FD | 1010 0110 | A6 | 0 | | | | +| CVT_BO | 1010 1000 | A8 | 0 | | | | +| CVT_OW | 1010 1001 | A9 | 0 | | | | +| CVT_SU | 1010 1010 | AA | 0 | | | | +| CVT_WU | 1010 1100 | AC | 0 | | | | +| CVT_OB | 1011 0001 | B1 | 0 | | | | +| CVT_SB | 1011 0010 | B2 | 0 | | | | +| CVT_LB | 1011 0011 | B3 | 0 | | | | +| CVT_WB | 1011 0100 | B4 | 0 | | | | +| CVT_UB | 1011 0101 | B5 | 0 | | | | +| CVT_WO | 1011 1001 | B9 | 0 | | | | +| CVT_LS | 1011 1010 | BA | 0 | | | | + +**Table B.1/T.173 – Encoding of MHEG-SIR instructions** *(concluded)* + +| Instruction mnemonics | Op-code (binary) | Opcode (hexa) | Op1 length | Op1 encoding | Op2 length | Op2 encoding | +|-----------------------|------------------|---------------|------------|---------------------|------------|------------------| +| CVT_FL | 1011 1011 | BB | 0 | | | | +| CVT_UW | 1011 1100 | BC | 0 | | | | +| CVT_FU | 1011 1101 | BD | 0 | | | | +| CVT_DF | 1011 1110 | BE | 0 | | | | +| JT | 1100 0000 | C0 | 1 | (signed) offset | | | +| JF | 1100 0001 | C1 | 1 | (signed) offset | | | +| JMP | 1100 0010 | C2 | 1 | (signed) offset | | | +| SHIFT_O | 1100 0101 | C5 | 1 | (signed) offset | | | +| SHIFT_W | 1100 0110 | C6 | 1 | (signed) offset | | | +| SHIFT_U | 1100 0111 | C7 | 1 | (signed) offset | | | +| GETOR | 1100 1001 | C9 | 1 | package identifier | | | +| LJT | 1101 0000 | D0 | 2 | (signed) offset | | | +| LJF | 1101 0001 | D1 | 2 | (signed) offset | | | +| LJMP | 1101 0010 | D2 | 2 | (signed) offset | | | +| CALL | 1101 0100 | D4 | 2 | function identifier | | | +| XCALL | 1101 0110 | D6 | 2 | function identifier | | | +| PUSH | 1110 0000 | E0 | 2 | data identifier | | | +| PUSHR | 1110 0001 | E1 | 2 | data identifier | | | +| PUSHI | 1110 0011 | E3 | 2 | (signed) value | | | +| POP | 1110 0100 | E4 | 2 | data identifier | | | +| POPR | 1110 0101 | E5 | 2 | data identifier | | | +| POPC | 1110 0110 | E6 | 2 | data identifier | | | +| ALLOC | 1110 1000 | E8 | 2 | type identifier | | | +| INC | 1110 1100 | EA | 2 | data identifier | | | +| DEC | 1110 1101 | EB | 2 | data identifier | | | +| GET | 1111 0000 | F0 | 2 | data identifier | 1 | (unsigned) index | +| GETC | 1111 0010 | F2 | 2 | data identifier | 1 | (unsigned) index | +| SET | 1111 0100 | F4 | 2 | data identifier | 1 | (unsigned) index | +| SETC | 1111 0110 | F6 | 2 | data identifier | 1 | (unsigned) index | + +## ANNEX C + +### MHEG-SIR predefined elements + +This Annex lists the predefined types, functions and messages of MHEG-SIR, together with their corresponding indices. + +Predefined types, functions and messages may be referenced by their identifier and used within interchanged scripts in the same way types, functions and messages declared within the global declarations part of interchanged scripts would. + +## C.1 Predefined types + +MHEG-SIR predefined types comprise: + +- primitive types. +- MHEG API types. + +### C.1.1 Primitive types + +The primitive types defined by this Recommendation shall be encoded using predefined type identifiers as listed in Table C.1. + +**Table C.1/T.173 – Predefined type identifiers +for primitive types** + +| Type name | Type identifier | +|-------------------------|-----------------| +| void | 0 | +| octet | 1 | +| short | 2 | +| long | 3 | +| unsigned short | 4 | +| unsigned long | 5 | +| float | 6 | +| double | 7 | +| boolean | 8 | +| character | 9 | +| data identifier | 10 | +| object reference | 11 | + +All types that may be expressed in MHEG-SIR (including predefined MHEG types) can be built using the MHEG-SIR primitive types and the following constructors: + +- **string**; +- **sequence**; +- **array**; +- **structure**; +- **union**. + +By convention, the unbounded **string** type (the only constructed type without an element or a parameter) shall be predefined and shall have 12 as its type identifier. + +### C.1.2 MHEG API types + +The MHEG API types defined by the MHEG API shall be encoded using predefined type identifiers. + +NOTE – MHEG API types are intended for use by interchanged scripts to express information which is exchanged between the script interpreter and MHEG entities. + +The IDL definition of these types, as provided by an MHEG API, shall be mapped to MHEG-SIR type descriptions using the general IDL mapping rules defined in clause 14 and the specific MHEG API mapping rules defined in E.2. + +## C.2 Predefined functions + +MHEG-SIR predefined functions comprise: + +- MHEG API operations; +- MHEG-3 API operations. + +### C.2.1 MHEG API operations + +The MHEG API operations defined by the MHEG API shall be encoded using predefined function identifiers. + +Predefined message identifiers for the MHEG API operations shall start at 1100h. + +The IDL definition of these operations, as provided by the MHEG-3 API, shall be mapped to MHEG-SIR function descriptions using the general IDL mapping rules defined in clause 14 and the specific MHEG API mapping rules defined in E.2. + +### C.2.2 MHEG-3 API operations + +The MHEG-3 API operations defined by the MHEG-3 API, as defined in clause 15, shall be encoded using predefined function identifiers according to Table C.2. + +**Table C.2/T.173 – Predefined function identifiers for +MHEG-3 API operations** + +| Operation name | Predefined function index | Function identifier | +|----------------------------|---------------------------|---------------------| +| prepare | 0 | 1000h | +| destroy | 1 | 1001h | +| new | 2 | 1002h | +| delete | 3 | 1003h | +| setPriority | 4 | 1004h | +| getPriority | 5 | 1005h | +| setData | 6 | 1006h | +| getData | 7 | 1007h | +| allocate | 8 | 1008h | +| free | 9 | 1009h | +| stop | 10 | 100Ah | +| reInit | 11 | 100Bh | +| getRtScriptStatus | 12 | 100Ch | +| open | 13 | 100Dh | +| close | 14 | 100Eh | +| getRoutineId | 15 | 100Fh | +| setParameter | 16 | 1010h | +| getPrototype | 17 | 1011h | +| run | 18 | 1012h | +| reset | 19 | 1013h | +| getInvocationStatus | 20 | 1014h | + +The IDL definition of these operations, as defined in Annex F, shall be mapped to MHEG-SIR function descriptions using the IDL mapping rules defined in clause 14. + +### C.3 Predefined messages + +MHEG-SIR predefined messages targeted at an rt-script result from: + +- invocation of the MHEG-3 API **run** operation; +- the **InstructionExecutionError** exception; +- MHEG-3 API exceptions; +- MHEG API exceptions. + +#### C.3.1 MHEG-3 API operations + +The identifier of the message resulting from the invocation of a **run** operation, as defined in subclause 15.4.5, shall be equal to the function identifier of the target routine. + +Messages resulting from MHEG-3 API operations shall therefore have a message identifier value between 0 and 0FFFh. + +#### C.3.2 The **InstructionExecutionError** exception + +The **InstructionExecutionError** exception, as defined in 9.5.2, shall have 1000h as its message identifier. + +The **InstructionExecutionError** exception shall have one member of type **unsigned long**, whose value shall be set to the value of the ER. + +The major error code shall determine the least significant byte of the member (and the ER) as defined by Table C.3. + +**Table C.3/T.173 – Instruction execution error codes** + +| Error name | Error code | +|-------------------------------|------------| +| InvalidOperand | 1 | +| InvalidParameter | 2 | +| InvalidType | 3 | +| InvalidIdentifier | 4 | +| InvalidLevel | 5 | +| InvalidIndex | 6 | +| StackUnderflow | 7 | +| ArithmeticOverflow | 8 | +| DivisionByZero | 9 | +| HandlerNotFound | 10 | +| InvalidReturnValue | 11 | +| BadPackageStatus | 12 | +| InvalidObjectReference | 13 | +| TypeMismatch | 14 | +| JumpOutOfRange | 15 | +| AllocationFailed | 16 | + +### C.3.3 MHEG-3 API exceptions + +The MHEG-3 API exceptions, as defined in clause 15, shall have the message identifiers defined by Table C.4. + +**Table C.4/T.173 – Predefined message identifiers for the MHEG-3 API exceptions** + +| Exception name | Predefined message index | Message identifier | +|-------------------------|--------------------------|--------------------| +| InvalidScript | 1 | 1001h | +| InvalidParameter | 2 | 1002h | +| OperationFailed | 3 | 1003h | + +The IDL definition of these exceptions, as defined in Annex F, shall be mapped to MHEG-SIR message descriptions using the IDL mapping rules defined in clause 14. + +### C.3.4 MHEG API exceptions + +The MHEG API exceptions defined by the MHEG API shall be encoded using predefined message identifiers. + +Predefined message identifiers for the MHEG API exceptions shall start at 1100h. + +The IDL definition of these exceptions, as provided by the MHEG API, shall be mapped to MHEG-SIR message descriptions using the general IDL mapping rules defined in clause 14 and the specific MHEG API mapping rules defined in E.2. + +## ANNEX D + +### IDL Platform mapping specification form + +MHEG-3 engines shall allow access to the services provided by the run-time environment of a given platform, provided this run-time environment complies with the registered "platform mapping specification" for this platform. + +The registered "platform mapping specifications" shall be provided according to the template specified in this Annex, with all fields being completed. + +This MHEG-SIR platform-mapping specification defines the mechanisms that need to be used by MHEG-3 engines to access the services provided by the run-time environment on the platform. + +#### Platform description + +The platform to which this specification applies is . + +#### Package availability procedure + +To know whether an IDL specification is available within the run-time environment and to locate it, an MHEG-3 engine shall proceed as follows. + +#### Package load procedure + +To make the operations of an available IDL specification accessible, an MHEG-3 engine shall proceed as follows. + +### **Package unload procedure** + +To stop the operations of an available IDL specification from being accessible, an MHEG-3 engine shall proceed as follows. + +### **Operation invocation procedure** + +To invoke an operation of an accessible IDL specification, an MHEG-3 engine shall proceed as follows. + +### **Parameter passing procedure** + +When invoking an IDL operation, an MHEG-3 engine shall pass **in** parameters as follows. + +When invoking an IDL operation, an MHEG-3 engine shall pass **out** parameters as follows. + +When invoking an IDL operation, an MHEG-3 engine shall pass **inout** parameters as follows. + +### **Output parameter retrieval procedure** + +To retrieve the values of **out** or **inout** parameters after invoking an IDL operation, an MHEG-3 engine shall proceed as follows. + +### **Return value retrieval procedure** + +To retrieve the return value of a previously invoked IDL operation, an MHEG-3 engine shall proceed as follows. + +### **Data encoding rules** + +The values of data that are interchanged between the MHEG-3 engine and the run-time environment shall be encoded as follows. + +### **Exception retrieval procedure** + +To retrieve exceptions that are raised by the run-time environment, an MHEG-3 engine shall proceed as follows. + +### **System exceptions** + +The system exceptions that may be raised by the run-time environment and retrieved by an MHEG-3 engine are defined as follows. + +### **Resource limitations** + +When using the run-time environment on the platform, the following resource limitations apply. + +**MHEG API definition process** + +As exposed in 8.3.3, this generic Recommendation does not define a specific MHEG API. It defines instead a generic set of rules and procedures applicable to the definition of the MHEG API to be provided by any Recommendation that describes presentation objects. This comprises: + +- the rules that shall be used to produce the MHEG API definition (see E.1); +- the procedure that shall be used to define the MHEG-SIR mapping of this MHEG API (see E.2). + +**E.1 Generic API definition framework** + +Producing an MHEG API specification from another Recommendation that describes presentation objects (hereafter called an MHEG specification) is a process that consists in producing IDL elements from MHEG elements. + +The MHEG elements on which this process applies are described in E.1.1. The IDL elements to be produced from these MHEG elements are described in E.1.2. The rules used to produce the IDL elements from the MHEG elements are described in E.1.3 and the subsequent subclauses. + +**E.1.1 MHEG elements input to MHEG API definition process** + +The ITU-T Recommendations of the T.170-Series (and parts of ISO/IEC 13522) share a number of key features. The following MHEG elements must be present in the source MHEG specification: + +- MHEG data types, described using ASN.1 or Extended Backus-Naur Form (EBNF); +- MHEG entities (i.e. objects targeted by MHEG elementary actions), related to each other by inheritance relationships; +- static and dynamic attributes of MHEG entities; +- MHEG elementary actions applying to MHEG entities; +- MHEG exceptions raised as the MHEG effect of elementary actions. + +**E.1.2 IDL elements output by MHEG API definition process** + +The API definition process should consist in mapping these elements to a set of IDL elements: + +- IDL non-object types shall map MHEG data types; +- IDL object interfaces, related to each other by inheritance relationships, shall map MHEG entities; +- IDL attributes, provided by IDL object interfaces, shall map static and dynamic attributes of MHEG entities; +- IDL operations, provided by IDL object interfaces, shall map MHEG elementary actions; +- IDL exceptions shall map MHEG exceptions raised as the effect of elementary actions. + +**E.1.3 Requirements on the MHEG API definition process** + +According to ISO/IEC JTC 1 guidelines for API standardization, the MHEG API shall be defined as an abstract API specification, i.e. a language-independent description of the semantics of a set of functionality in an abstract syntax using abstract data types. + +As an enforcement of the recommendations of ETR 225 "API and script representation for MHEG - Requirements and framework", an MHEG API definition shall meet the following requirements: + +- portability (see E.1.3.1); +- genericity (see E.1.3.2); +- conformance testability (see E.1.3.3); +- implementability (see E.1.3.4). + +#### **E.1.3.1 Portability** + +The **portability** requirement states that MHEG applications need to use the MHEG object manipulation and interchange service provided by MHEG engines (i.e. an MHEG API) in a way independent of: + +- the programming language used for the MHEG application; +- the underlying operating system. + +To meet the portability requirement, an MHEG API shall be defined as an abstract API specification. + +#### **E.1.3.2 Genericity** + +The **genericity** requirement states that all the common requirements of MHEG applications need to be supported by an MHEG API. + +To meet the genericity requirement, an MHEG API shall be defined at the most primitive level, i.e. in terms of primitives that match MHEG elementary actions and data types that match MHEG data types. This guarantees to maximize the range of MHEG object manipulations made available to applications. + +#### **E.1.3.3 Conformance testability** + +The **conformance testability** requirement states that it should be as easy as possible to test: + +- the conformance of an MHEG engine to an MHEG API specification, i.e. the correct provision of this API by an MHEG engine under test; +- the conformance of an MHEG application to an MHEG API specification, i.e. the correct use of this API by an MHEG application under test. + +To meet the conformance testability requirement, an MHEG API shall express formally its requirements on conforming implementations and conforming applications and it shall use a formal description technique for the definition of the MHEG API. + +#### **E.1.3.4 Implementability** + +The **implementability** requirement states that implementation of MHEG engines that conform to the MHEG API specification need to be as easy as possible. For this purpose, the MHEG API definition should take into account simplicity and clarity both in the definition and the formulation. + +To meet the implementability requirement, an MHEG API shall provide or refer to guidelines to produce language mapping specifications and message encoding rules from the abstract API specification. + +#### **E.1.3.5 Fulfilment of technical requirements** + +The use of IDL contributes to the fulfilment of the portability and implementability technical requirements: + +- IDL is independent from a programming language. Moreover, there are public specifications of IDL mappings to common programming languages such as C and C++; + +- IDL provides a complete formal description language which allows a very concise, readable, efficient specification of an MHEG API. Moreover, IDL is also appropriate for automatic compilation, so that MHEG API implementations may be automatically generated for a given language and operating system using appropriate IDL compilers. + +#### E.1.4 General structure of the MHEG API + +The MHEG API shall be defined using IDL as defined in ISO/IEC 14750-1 [8]. The use of IDL does not imply a Common Object Request Broker Architecture (CORBA) environment. Therefore, beside its use of IDL, the MHEG API shall be defined in a way independent of the CORBA architecture. + +The IDL interface definition shall consist of two modules providing different API functionality. The first module shall provide MHEG interpretation services. It shall be named module **MHEG\_** where is a number designating the Recommendation targeted by the API. The second module shall provide accessor and modifier services for encoded MHEG entities. It shall be named module **MHEG\_\_Access** where is a number designating the Recommendation targeted by the API. + +The API shall provide an interface enabling the creation of an interface object instance. This interface shall be named **MHEGEntityManager**. Operations enabling the deletion of an IDL instance shall be provided by the interfaces that map MHEG entities. + +Each interface mapping a MHEG entity that provides a common reference scheme for its subclasses shall also provide the following operations: + +- **attach**; +- **detach**; +- **getIdentifier**. + +The **attach** operation binds an interface object instance with an MHEG entity and returns the identifier of the bound object. The **detach** operation cancels the binding. The **getIdentifier** operation retrieves the identifier of the MHEG entity bound with the interface object instance. + +The IDL concepts used to design the interface shall map MHEG concepts according to the rules described in the following subclauses. IDL identifiers shall map MHEG ASN.1 identifiers according to the rules defined in the following subclauses. + +The following operations shall be synchronous: create, bind, unbind, accessors and modifiers, GET operations. Other elementary actions shall be mapped to asynchronous operations. + +The API definition shall not use nested scoping levels. + +#### E.1.5 IDL non-object datatype definition + +IDL non-object types shall map MHEG datatypes expressed using ASN.1. + +##### E.1.5.1 Name mapping + +##### E.1.5.1.1 Data types + +ASN.1 data type names shall be mapped to IDL type names as follows: + +- if the ASN.1 type name consists of more than one word, no separators shall be used in the IDL name; +- each word shall start with a capital letter, all other letters shall be in lower case. + +Example: The ASN.1 **type-name** shall be mapped to the IDL **TypeName**. + +### E.1.5.1.2 Components + +ASN.1 component names shall be mapped to IDL field names as follows: + +- if the ASN.1 name consists of more than one word, the underscore character ("\_") shall be used as a separator; +- all letters shall be in lower case; +- as IDL is not case-sensitive, type names and field names may collide when single-word names are used. In such a case, the field name shall be prefixed by "the\_". The same rule shall be used when a single-word component name collides with an IDL keyword. + +Example: + +``` +// regular field name +TypeName field_name +``` + +``` +// collision between field name and type name +Alias the_alias +``` + +``` +// collision between field name and IDL keyword ("string") +Type the_string +``` + +### E.1.5.1.3 Values + +ASN.1 value names shall be mapped to IDL value names as follows: + +- a) if the name consists of more than one word, the underscore character ("\_") shall be used as a separator; +- b) all letters shall be in upper case; +- c) as an IDL enumeration does not create a new scope, values used within enumerations may collide. In such a case, for one of the colliding enumerations all value names (not only the one which collides) shall be prefixed by the name of the enumerated type. This type name shall be built using rules a) and b) (and not the regular rules for type names). + +Example: + +``` +// regular value name +FIRST_VALUE +``` + +``` +// value name in case of a collision +FIRST_ENUMERATION_FIRST_VALUE +``` + +## E.1.5.2 Type mapping + +### E.1.5.2.1 INTEGER + +An ASN.1 **INTEGER** type shall be mapped to an IDL **long** type. + +Example: + +``` +-- ASN.1 +Type ::= INTEGER +``` + +``` +// IDL +typedef long Type; +``` + +### E.1.5.2.2 BOOLEAN + +An ASN.1 **BOOLEAN** type shall be mapped to an IDL **boolean** type. + +Example: + +``` +-- ASN.1 +Type ::= BOOLEAN +``` + +``` +// IDL +typedef boolean Type; +``` + +#### E.1.5.2.3 OCTET STRING + +An ASN.1 **OCTET STRING** type shall be mapped to an IDL **sequence** type. + +Example: + +``` +-- ASN.1 +Type ::= OCTET STRING +``` + +``` +// IDL +typedef sequence Type; +``` + +#### E.1.5.2.4 ENUMERATED + +An ASN.1 **ENUMERATED** type shall be mapped to an IDL **enum** type. + +Example: + +``` +-- ASN.1 +Type ::= ENUMERATED {value_1 (1), value_2 (2)} +``` + +``` +// IDL +enum Type (VALUE_1, VALUE_2); +``` + +#### E.1.5.2.5 SEQUENCE OF + +An ASN.1 **SEQUENCE OF** type shall be mapped to an IDL **sequence** type. + +Example: + +``` +-- ASN.1 +Type ::= SEQUENCE OF OtherType +``` + +``` +// IDL +typedef sequence Type; +``` + +#### E.1.5.2.6 CHOICE + +An ASN.1 **CHOICE** type shall be mapped to an IDL discriminated union by combining **enum** and **union**. The **enum** type name shall be derived from the name of the **CHOICE** type suffixed by "Tag" in order not to collide with the **union** type name. The **enum** value names shall be derived from the names of the **CHOICE** type fields suffixed by "\_TAG" in order not to collide with field names within the **switch**. Within a **CHOICE** a **NULL** component shall be mapped on an empty **case**. + +Example: + +``` +-- ASN.1 +Type ::= CHOICE +{ + a A, + b B, + c NULL +} +``` + +``` + +// IDL +enum TypeTag { A_TAG, B_TAG, C_TAG }; +union Type +switch TypeTag { + case A_TAG: + A the_a; + case B_TAG: + B the_b; + // no'case' for C_TAG +}; + +``` + +### E.1.5.2.7 SEQUENCE + +An ASN.1 **SEQUENCE** type shall be mapped to an IDL **struct** type. **OPTIONAL** ASN.1 components with or without **DEFAULT** values shall be mapped to an IDL **sequence** of at most one element of that type. + +Example: + +``` + +-- ASN.1 +Type ::= SEQUENCE +{ + a A OPTIONAL, + b B, + c INTEGER DEFAULT 0 +} + +// IDL +struct Type { + sequence the_a; + B the_b; + sequence c; +}; + +``` + +### E.1.5.3 Order of declarations + +The order of type declarations may be different between ASN.1 and IDL because IDL does not allow the use of a type before its declaration (and does not provide a forward declaration functionality). IDL type declarations shall be reordered to deal with this constraint. + +To enable reordering, cross-references from the ASN.1 syntax shall be suppressed. + +The following examples show cross-references commonly used in ASN.1 and how they should be removed. + +Example 1: + +``` + +-- ASN.1 definition using a cross-reference +-- Production rules used : +-- T = A / B +-- B = T C +-- Allowed values : +-- a c* + +-- T refers to B +T ::= CHOICE +{ + a A, + b B +} +-- B refers to T + +``` + +**B ::= SEQUENCE** + +``` +{ + t T, + c C +} +``` + +-- Equivalent ASN.1 definition without cross-reference + +-- The information described remains the same, the structure has changed + +-- Production rules used : + +-- $T = A C^*$ + +**T ::= SEQUENCE** + +``` +{ + a A, + s_o_c SEQUENCE OF C OPTIONAL +} +``` + +Example 2: + +-- ASN.1 definition using a cross-reference + +-- Production rules used : + +-- $T = A \mid B$ + +-- $B = C T$ + +-- Allowed values : + +-- $c^*a$ + +-- T refers to B + +**T ::= CHOICE** + +``` +{ + a A, + b B +} +``` + +-- B refers to T + +**B ::= SEQUENCE** + +``` +{ + c C, + t T +} +``` + +-- Equivalent ASN.1 definition without cross-reference + +-- The information described remains the same, the structure has changed + +-- Production rules used : + +-- $T = C^* A$ + +**T ::= SEQUENCE** + +``` +{ + s_o_c SEQUENCE OF C OPTIONAL, + a A +} +``` + +However, in most cases cross-referencing should be removed by the creation of nested types, as shown in Example 3. + +Example 3: + +-- ASN.1 definition using a cross-reference + +-- T refers to A + +``` + +T ::= CHOICE +{ + a A, + b B +} + +``` + +*A ::= -- A definition that refers to T (either directly or indirectly)* + +*-- Equivalent ASN.1 definition without cross-reference* + +``` + +T ::= CHOICE +{ + a -- A definition + b B +} + +``` + +The disadvantage of the method shown in Example 3 is that very complex datatypes may be created. Moreover part of the datatypes so created might duplicate types already defined in the syntax. + +Another option is to translate the "A" ASN.1 datatype into an "A" IDL interface embedding the corresponding "A" IDL datatype. This allows to use a forward declaration of the "A" IDL interface as illustrated in Example 4. + +Example 4: + +``` + +interface A; // forward declaration + +``` + +``` + +enum TTag { A_TAG, B_TAG }; +union T +switch TTag { + case A_TAG: + A the_a; + case B_TAG: + B the_b; +}; + +``` + +``` + +interface A { + +``` + +``` + +// this interface embeds the definition of type A which refers to type T + +``` + +``` + +}; + +``` + +### E.1.6 IDL interface definition + +MHEG entities shall be mapped on IDL interfaces according to the following rules: + +- every element that may be designated as a target of an MHEG elementary action shall be considered as an entity. Not all entities are explicitly defined by the MHEG standard. Moreover not all of them exist in the MHEG object model. Therefore the MHEG object model shall be refined to integrate all the entities used; +- if an elementary action may target different types of entities, a new entity shall be created aggregating these entities; +- the name of the new created entity shall be the concatenation of the names of the entities it aggregates using "Or" as a separator; +- the obtained object model is the API object model. There shall be a one-to-one correspondence between entities and interfaces; +- the IDL inheritance hierarchy shall correspond to the hierarchy of the API object model; +- interface names shall be derived from entity names using the same rules as for datatypes. + +### E.1.7 IDL attribute definition + +The following categories of MHEG attributes are identified: + +- interchanged attributes; +- internal attributes. + +#### E.1.7.1 MHEG interchanged attributes + +MHEG interchanged attributes shall be mapped to IDL attributes in the module **MHEG--access** according to the following rules: + +- every ASN.1 type whose name ends with "Class" shall be mapped to an interface; +- within the type [see a)], the ASN.1 **COMPONENTS OF** ASN.1 shall be mapped to the IDL inheritance functionality; +- within the type [see a)], every component shall be mapped to an attribute; +- the naming and typing of attributes shall follow the rules defined in E.1.5. + +Example: + +-- ASN.1 + +``` +B-Class ::= SEQUENCE +{ + COMPONENTS OF A-Class, + i INTEGER, + j C-Type +} +``` + +// IDL + +``` +interface BClass : AClass { + attribute long i; + attribute CType j; +}; +``` + +#### E.1.7.2 MHEG internal attributes + +MHEG internal attributes shall not be mapped to IDL attributes. MHEG internal attributes are accessed and modified through the use of MHEG elementary actions which shall be mapped to IDL operations. + +### E.1.8 IDL operation definition + +The MHEG API interfaces shall provide the following categories of operations: + +- operations that map MHEG elementary actions targeting the MHEG entity to which the interface corresponds; +- operations used to delete an interface instance (see Note); +- operations used to attach and detach an interface instance to a MHEG entity. + +NOTE – The creation of an interface instance is provided by the factory interface. + +#### E.1.8.1 Operations mapping MHEG elementary actions + +MHEG elementary actions shall be mapped to IDL operations according to the following rules: + +- there shall be a one-to-one correspondence between elementary actions and operations; + +- b) the interface that provides an operation shall correspond to the target entity of the elementary action; +- c) the name of the operation shall be derived from the name of the elementary action using the following rules: + - 1) if an operation name consists of more than one word, no separators shall be used; + - 2) the operation name shall start with a lower-case letter; + - 3) each word (except the first) shall start with a capital letter. +- d) a "Set" elementary action shall be mapped to an operation according to the following rules: + - 1) the return value of the operation shall be of type **void**; + - 2) there shall be only input parameters; + - 3) the datatypes and names of the parameters shall be derived from the ASN.1 elementary action definition using the rules defined in E.1.5; + - 4) the first parameter of the ASN.1 elementary action definition shall not be mapped (it represents the target of the elementary action); + - 5) if the macro functionality is used for the definition of a parameter, the embedded datatype shall be used; + - 6) if the embedded datatype referenced in d 5) is not explicitly defined, it shall be created as outlined in Example 1 in E.1.5.3. +- e) a "Get" elementary action shall be mapped to an operation according to the following rules: + - 1) the return value of the operation shall be the value evaluated by the elementary action; + - 2) the datatype of the return value does not exist as such in the MHEG ASN.1 syntax because elementary actions are evaluating generic value. It shall therefore be one of the following: + - i) a simple datatype; + - ii) a complex datatype that is used in the corresponding "Set" elementary action; + - iii) if a complex datatype is returned and no corresponding "Set" elementary action exists, the datatype shall be created. + - 3) there shall be no output parameters, all results shall be passed using the return value; + - 4) for input parameters, the rules defined in d 3), d 4), d 5), d 6) shall apply. + +Example: + +``` + +Elementary-Action-N ::= SEQUENCE +{ + target Target, -- to be skipped + param1-param Param1-Parameter, -- replace + param2-param Param2-Parameter -- replace +} + +``` + +``` + +Param1-Parameter ::= CHOICE +{ + param1 Param1, + param1-macro Param1-Macro +} + +``` + +**Param1-Macro ::= SEQUENCE** + +``` +{ + -- ... + -- ... +} +``` + +**Param1 ::= -- ...** + +-- *In "Elementary-Action-N" the "param1-parameter" parameter shall be replaced with the* +-- *"param1" parameter* + +**Param2-Parameter ::= CHOICE** + +``` +{ + a-param A-Parameter, + b-param B-Parameter +} +``` + +**A-Parameter ::= CHOICE** + +``` +{ + a A, + a-macro A-Macro +} +``` + +**A-Macro ::= SEQUENCE** + +``` +{ + -- ... + -- ... +} +``` + +**A ::= -- ...** + +**B-Parameter ::= SEQUENCE** + +``` +{ + -- ... + -- ... +} +``` + +**B-Macro ::= SEQUENCE** + +``` +{ + -- ... + -- ... +} +``` + +**B ::= -- ...** + +-- *In "Elementary-Action-N" the "param2-parameter" parameter cannot be replaced with the* +-- *"param2" parameter because it does not exist. Consequently an IDL datatype that* +-- *corresponds to the following ASN.1 datatype shall be created:* + +**Param2 ::= CHOICE** + +``` +{ + a A, + b B +} +``` + +### **E.1.8.2 Operations enabling the deletion of an interface instance** + +Each interface shall provide an operation enabling the deletion of an interface instance. This operation shall have the following prototype: + +``` +void kill(); +``` + +### E.1.8.3 Operations to attach and detach an interface instance to a MHEG entity + +Each interface shall provide operations enabling to attach and detach an interface instance to a MHEG entity. These operations shall be named **attach** and **detach** respectively. The **attach** operation shall accept an MHEG entity reference as parameter, resolve this reference and return an MHEG entity identifier. The **detach** operation shall accept no parameter. + +Each interface shall provide an operation to retrieve the identifier of the MHEG entity attached to an interface instance. This operation shall be named **getIdentifier**. It shall accept no parameter and return an MHEG entity identifier. + +### E.1.9 IDL exception definition + +IDL exceptions shall map MHEG error conditions associated with elementary actions. Error conditions should be classified according to their nature so as to get a limited set of IDL exceptions. + +The following set of exceptions is recommended: + +- **InvalidTarget**; +- **InvalidParameter**; +- **NotBound**; +- **AlreadyBound**. + +The **InvalidTarget** exception is raised when the targeted MHEG entity is not available. The **period** member returns the current state (life cycle period) of the target. + +The **InvalidParameter** exception is raised when the value of one of the parameters prohibits the normal execution of the action. The **completion\_status** member indicates whether the action has been completed (with a default value assigned to the inadequate parameter) or not. The **parameter\_number** member identifies the rank of the invalid parameter. + +The **NotBound** exception is raised when the interface object instance is not bound with an MHEG entity. + +The **AlreadyBound** exception is raised when the interface object instance is already bound with an MHEG entity. The **entity\_identifier** member identifies the bound entity. + +The IDL definition of these exceptions is as follows: + +``` +exception InvalidTarget { + unsigned short period; +}; + +enum CompletionStatus { YES, NO }; + +exception InvalidParameter { + CompletionStatus completion_status; + unsigned short parameter_number; +}; + +typedef long EntityIdentifier; + +exception AlreadyBound { + EntityIdentifier entity_identifier; +}; + +exception NotBound {}; +``` + +The above-mentioned exceptions shall be defined within the global scope. + +If an error condition cannot be handled by the above-mentioned exceptions, a specific exception shall be created at the appropriate interface scoping level. + +The IDL exception names for specific exceptions shall be derived from the name of the MHEG error condition using the same rules as for datatypes: + +- no separators shall be used; +- the exception name shall start with a capital letter; +- if an exception name consists of more than one word, no separators between words shall be used and each word shall start with a capital letter. + +## E.2 MHEG API mapping to MHEG-SIR + +Producing the MHEG API mapping to MHEG-SIR is a process that consists in assigning predefined type identifiers, predefined function identifiers and predefined message identifiers to map MHEG API types, operations and exceptions. + +This mapping process shall consist of three consecutive steps: + +- a) extract intermediate types until all type definitions have only one level (see Example 1 in E.1.5.3); +- b) change IDL **enum** types to **unsigned long** (MHEG-SIR provides no enumerated datatype). Compute for each type definition its "level" number, i.e. its highest possible distance from the leaf. Unify equivalent types, starting with those with the lowest "level" number; +- c) scan the resulting IDL specification to allocate predefined IDs. Assign predefined TIDs and MIDs as soon as new types or exceptions are encountered. For each object, assign predefined FIDs for each explicitly defined operation, for each inherited operation that is not overridden by an explicitly defined one, for each attribute accessor and for each attribute modifier. + +Example: + +``` +struct A { + int a; + struct { + int b; + struct { + int c; + int d; + } b + } c +}; +``` + +// after extraction of intermediate types (a)) + +``` +struct A { + int a; + B b; +}; +struct B { + int b; + C c; +}; +struct C { + int c; + int d; +}; +``` + +## ANNEX F + +### IDL specification of the MHEG-3 API + +To express direct manipulation of other scripts, interchanged scripts shall use the MHEG-3 mapping (as defined in Annex B) of the MHEG-3 API. + +MHEG-3 engines shall provide the MHEG-3 API as specified by the IDL `MHEG_3` module. + +``` +module MHEG_3 { + + enum RtScriptStatus {RUNNING, READY, ERRONEOUS}; + enum InvocationStatus {NOT_STARTED, PROCESSING, TERMINATED, ABORTED}; + enum PassingMode {BY_VALUE, BY_REFERENCE}; + enum Entity {TYPE, DATA, FUNCTION, MESSAGE, PACKAGE, HANDLER}; + + typedef unsigned short FID; + typedef unsigned short DID; + typedef unsigned short TID; + + struct ContentReference { + string public_id; + string system_id; + }; + struct ParameterDescription { + PassingMode passing_mode; + TID parameter_type_id; + }; + struct Prototype { + TID return_value_type_id; + sequence signature; + }; + + exception InvalidParameter { + unsigned short rank; + }; + exception InvalidScript { + Entity the_entity; + unsigned short identifier; + }; + exception OperationFailed {}; + + interface MhScript; + interface RtScript; + interface RoutineInvocation; + + interface ScriptInterpreter { + MhScript prepare (in ContentReference content_reference) + raises (InvalidScript, InvalidParameter, OperationFailed); + void kill (); + }; + + interface MhScript { + RtScript new () + raises (OperationFailed); + void destroy (); + }; + interface RtScript { + RoutineInvocation open (in FID routine_id) + raises (InvalidParameter); + }; +} +``` + +``` + +RtScriptStatus getRtScriptStatus(); + +void setPriority (in unsigned short priority); +unsigned short getPriority (); + +DID allocate (in TID variable_type_id) + raises (InvalidParameter, OperationFailed); +void free (in DID variable_id) + raises (InvalidParameter); + +void setData (in DID variable_id, in any variable_value) + raises (InvalidParameter, OperationFailed); +any getData (in DID data_id) + raises (InvalidParameter, OperationFailed); + +void stop () + raises (OperationFailed); +void reInit () + raises (OperationFailed); +void delete (); +}; + +interface RoutineInvocation { + + readonly attribute FID routine_id; + + void setParameter (in unsigned short rank, in TID parameter_type_id, + in any parameter_value) + raises(InvalidParameter); + + Prototype getPrototype (); + InvocationStatus getInvocationStatus (); + + void run () + raises (OperationFailed); + + void reset (); + void close (); +}; +}; + +``` + +## ANNEX G + +### Relationships with other ITU-T Recommendations of the T.170-Series (and parts of ISO/IEC 13522) + +#### G.1 Relationships with ITU-T Rec. T.171 (and ISO/IEC 13522-1) + +This subclause specifies the requirements that apply when this Recommendation is used to extend the provisions of ITU-T Rec. T.171 (and ISO/IEC 13522-1) [5]. + +The statement "other ITU-T Recommendations of the T.170-Series" ("one of the parts of ISO/IEC 13522") used in this Recommendation shall be interpreted to be "ITU-T Rec. T.171" ("ISO/IEC 13522-1"). + +The MHEG-SIR defined by this Recommendation shall apply to the encoding of the **script-data** component of ITU-T Rec. T. 171 (ISO/IEC 13522-1) conforming objects of the **script** class, whose **script-classification** component is registered within the **registered-script-classification** catalogue to indicate + +"script" and whose **catalogued-script-encoding** component is registered within the **registered-script-classification** to indicate "MHEG-SIR", according to the values maintained by the MHEG registration authority. + +NOTE – These values are registered according to the provisions of ISO/IEC 13522-4 [6]. + +In this framework, the **script-data** component shall be encoded according to the following restrictions on the **ISOMHEG-sc** module defined in ITU-T Rec. T.171 (ISO/IEC 13522-1) [5]: + +- if the **script-inclusion** choice is selected for the **script-data** component, then the **interchangedscript** choice shall be selected for the **script-inclusion** component; +- if the **data-reference** choice is selected for the **script-data** component, then the referenced data shall be encoded as an **InterchangedScript** as specified by the **ISO-MHEG-sir** module. + +Hence MHEG-3 script objects shall conform to the syntax defined by the **SIR-Script-Class** subtype hereafter. + +*-- ISOMHEG-sir {joint-iso-itu-t(2) mheg (19) version (1) script-interchanged-representation (11)}* + +#### IMPORTS + +``` + +MHEG-Identifier, Catalogued-Script-Classification + FROM ISOMHEG-ud { joint-iso-itu(2) mheg(19) version(1) useful-definitions (9) } +Registered-Script-Encoding, Registered-Script-Classification + FROM ISOMHEG-cat { joint-iso-itu(2) mheg(19) version(1) catalogues (12) } +Script-Class + FROM ISOMHEG-sc { joint-iso-itu(2) mheg(19) version(1) script-class(3) } + +``` + +; + +**SIR-Script-Class ::= Script-Class (WITH COMPONENTS** + +``` + +{ + ..., + script-classification (WITH COMPONENTS + { + registered-script-classification ('script') }) PRESENT, + -- registered value as provided by ISOMHEG-cat + + script-hook (WITH COMPONENTS + { + ..., + catalogued-script-encoding (WITH COMPONENTS + { + registered-script-encoding('MHEG-SIR') }) PRESENT, + -- registered value as provided by ISOMHEG-cat + }) PRESENT, + + script-data (WITH COMPONENTS + { + ..., + script-inclusion (WITH COMPONENTS { interchangedscript }), + data-reference (WITH COMPONENTS { null-data ABSENT }) + }) PRESENT + }) + +``` + +## G.2 Relationships with ITU-T Rec. T.172 (and ISO/IEC 13522-5) + +This subclause specifies the requirements that apply when this Recommendation is used to extend the provisions of ITU-T Rec. T.172 (and ISO/IEC 13522-5) [7]. + +The statement "other ITU-T Recommendations of the T.170-Series" ("one of the parts of ISO/IEC 13522") used in this Recommendation shall be interpreted to be "ITU-T Rec. T.172" ("ISO/IEC 13522-5"). + +The MHEG-SIR defined by this Recommendation shall apply to the encoding of the **original-content** attribute of ITU-T Rec. T.172 (and ISO/IEC 13522-5) conforming **InterchangedProgram** objects + +whose **content-hook** component indicates "MHEG-SIR", according to the application domain definition. + +Within a value of the **InterchangedProgramClass** type, the following restrictions shall apply to the **ISOMHEG-MHEG-5** module defined in ITU-T Rec. T.172 (and ISO/IEC 13522-5) [7]: + +- if the **included-content** is selected for the **original-content** component, then the **OCTET STRING** value of the **included-content** component shall be replaced by a value of the **InterchangedScript** type as specified by the **ISO-MHEG-sir** module; +- if the **referenced-content** is selected for the **original-content** component, then the referenced data shall be a value of the **InterchangedScript** type as specified by the **ISO-MHEG-sir** module. + +Hence, MHEG-3 script objects shall conform to the syntax defined by the **SIR-Script-Class** subtype thereafter. + +**ISOMHEG-sir { joint-iso-itu-t(2) mheg (19) version (1) script-interchanged-representation (11) }** + +#### **IMPORTS** + +**InterchangedProgramClass** + +**FROM ISOMHEG-MHEG-5 { joint-iso-itu(2) mheg(19) version(1) MHEG-5 (17) }** + +; + +**SIR-Script-Class ::= InterchangedProgramClass (WITH COMPONENTS** + +**{**     **...,** +      **content-hook ('MHEG-SIR') PRESENT,** + +**original-content PRESENT,** + +*-- data encoded as InterchangedScript* + +**})** + +ITU-T Rec. T.172 (and ISO/IEC 13522-5) [7] make no distinction between mh-objects and rt-objects; both are called "MHEG-5 objects". Therefore, there shall be only one rt-script for each mh-script. As a consequence: + +- mh-script initialization and rt-script initialization shall be performed in a single operation (corresponding to the invocation of the **prepare** and **new** operations); +- invoking several new operations on the same mh-script shall raise an exception; +- rt-script destruction and mh-script destruction shall be performed in a single operation (corresponding to the invocation of the **delete** and **destroy** operations). + +## **APPENDIX I** + +### **MHEG-SIR syntax (EBNF notation)** + +This appendix describes the syntax of MHEG-SIR interchanged scripts. This syntax is equivalent to the ASN.1 specification in Annex A. + +**// Structure** + +**InterchangedScript ::= TypeDeclaration\*** + +**ConstantDeclaration\*** + +**VariableDeclaration\*** + +**PackageDeclaration\*** + +**HandlerDeclaration\*** + +**RoutineDeclaration\*** + +**// Type declarations** + +| | | +|-----------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| TypeDeclaration | ::= TypeIdentifier?
TypeDescription | +| TypeDescription | ::= SequenceDescription
StringDescription
ArrayDescription
StructureDescription
UnionDescription | +| SequenceDescription | ::= INTEGER? // Sequence bound
TypeIdentifier | +| StringDescription | ::= INTEGER? // String bound | +| ArrayDescription | ::= INTEGER // Array size
TypeIdentifier | +| UnionDescription | ::= TypeIdentifier+ | +| StructureDescription | ::= TypeIdentifier+ | +| // Data declarations | | +| ConstantDeclaration | ::= DataIdentifier?
TypeIdentifier
ConstantValue | +| ConstantValue | ::= BOOLEAN
OCTET
INTEGER // all numeric types
REAL // float or double
STRING // character or string
DataIdentifier
ConstantValue* // sequence, array or structure
UnionValue | +| UnionValue | ::= INTEGER // Tag index
ConstantValue | +| VariableDeclaration | ::= DataIdentifier?
TypeIdentifier
ConstantReference? // Initial value | +| ConstantReference | ::= DataIdentifier
ConstantValue | +| // Package declarations | | +| PackageDeclaration | ::= PackageIdentifier?
VisibleString // Package name
ServiceDescription*
ExceptionDescription* | +| ServiceDescription | ::= FunctionIdentifier?
VisibleString? // IDL global name
CallingMode?
TypeIdentifier? // return value
ParameterDescription* | +| ServiceParameterDescription | ::= ServicePassingMode?
TypeIdentifier | +| CallingMode | ::= 'SYNCHRONOUS' 'ASYNCHRONOUS' | + +``` + +ServicePassingMode ::= 'IN' | 'OUT' | 'INOUT' + +ExceptionDescription ::= MessageIdentifier? + VisibleString? //IDL exception global name + TypeIdentifier* //Parameter types + +// Handler declarations +HandlerDeclaration ::= MessageIdentifier + FunctionIdentifier + +// Routine declarations +RoutineDeclaration ::= FunctionIdentifier? + TypeIdentifier? // for return value + RoutineParameterDescription* + VariableDeclaration* + OCTET STRING // program code + +RoutineParameterDescription ::= RoutinePassingMode? + TypeIdentifier + +RoutinePassingMode ::= 'VALUE' | 'REFERENCE' + +// Useful definitions +TypeIdentifier ::= INTEGER +DataIdentifier ::= INTEGER +FunctionIdentifier ::= INTEGER +MessageIdentifier ::= INTEGER +PackageIdentifier ::= INTEGER + +``` + +## APPENDIX II + +### Textual notation for MHEG-SIR scripts + +This appendix describes a human-readable, text notation for the expression of MHEG-SIR scripts. It may be useful to express MHEG-SIR examples. It is given using EBNF notation. + +``` + +InterchangedScript ::= "SCRIPT " + TypeDeclaration* + ConstantDeclaration* + VariableDeclaration* + PackageDeclaration* + HandlerDeclaration* + RoutineDeclaration* + "ENDSCRIPT " + +// Type declarations +TypeDeclaration ::= "TYPE " + Identification? + TypeDescription + "ENDTYPE " + +TypeDescription ::= "SEQUENCE " SequenceDescription "ENDSEQUENCE " + | "STRING " StringDescription "ENDSTRING " + | "ARRAY " ArrayDescription "ENDARRAY " + | "STRUCT " StructureDescription "ENDSTRUCT " + | "UNION " UnionDescription "ENDUNION " + +SequenceDescription ::= INTEGER // Sequence bound + Reference // Type identifier + +``` + +``` + +StringDescription ::= INTEGER? // String bound + +ArrayDescription ::= INTEGER // Array size +Reference // Type identifier + +UnionDescription ::= Reference+ // Type identifiers + +StructureDescription ::= Reference+ // Type identifiers + +// Data declarations +ConstantDeclaration ::= "CONSTANT " +Identification? +Reference // Type identifier +ConstantValue +"ENDCONSTANT " + +ConstantValue ::= "BOOLEAN " BOOLEAN +| "OCTET " OCTET +| "SHORT " INTEGER +| "LONG " INTEGER +| "WORD " INTEGER +| "UNSIGNED " INTEGER +| "FLOAT " REAL +| "DOUBLE " REAL | "CHAR " STRING +| "STRING " STRING +| "IDENTIFIER " Reference // Data identifier +| "SEQUENCE " ConstantValue* +| "STRUCT " ConstantValue* +| "ARRAY " ConstantValue* +| "UNION " UnionValue + +UnionValue ::= INTEGER // Tag index +ConstantValue + +VariableDeclaration ::= "VARIABLE " +Identification? +Reference // Type identifier +ConstantReference? // Initial value (constant) +"ENDVARIABLE " + +ConstantReference ::= Reference // Data identifier +| ConstantValue + +// Package declarations +PackageDeclaration ::= "PACKAGE " +IntegerIdentification? +STRING? // Package name +ServiceDescription* +ExceptionDescription* +"ENDPACKAGE " + +ServiceDescription ::= "SERVICE " +IntegerIdentification? +STRING? // IDL operation global name +CallingMode? +Reference? // Return type identifier +ServiceParameterDescription* +"ENDSERVICE " + +ServiceParameterDescription ::= "PARAM " + +``` + +``` + +ServicePassingMode +Reference // Type identifier + +CallingMode ::= "SYNC " | "ASYN " +ServicePassingMode ::= "IN " | "OUT " | "INOUT " + +ExceptionDescription ::= "EXCEPTION " +IntegerIdentification? +STRING? //IDL exception global name +Reference* // Parameter type identifiers +"ENDEXCEPTION " + +// Handler declarations +HandlerDeclaration ::= "HANDLER " +Reference // Message identifier +Reference // Function identifier +"ENDHANDLER " + +// Routine declarations +RoutineDeclaration ::= "ROUTINE " +Identification? +Reference? // Return type identifier +RoutineParameterDescription* +VariableDeclaration* +Instruction+ +"ENDROUTINE " + +RoutineParameterDescription ::= "PARAM " +RoutinePassingMode? +Reference // Type identifier + +RoutinePassingMode ::= "VAL " | "VAR " + +// Useful definitions +Identification ::= "ID " Reference +IntegerIdentification ::= "ID " INTEGER + +INTEGER ::= DecimalInteger | HexInteger +DecimalInteger ::= Sign? Digit+ " " +Sign ::= "+" | "-" +Digit ::= "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" +HexInteger ::= "h" Hex+ +Hex ::= Digit | "A" | "B" | "C" | "D" | "E" | "F" +BOOLEAN ::= "TRUE " | "FALSE " +OCTET ::= Hex Hex " " +STRING ::= "" Character* "" +Character ::= ... // visible character +REAL ::= Sign? Digit+ "." Digit* "e" Sign? Digit+ " " + +// Program code +Instruction ::= SimpleInstruction " " +| LogicalOperator LogicalTypeCode " " +| "EQ_" TypeCode " " +| ComparisonOperator ComparisonTypeCode " " +| ArithmeticOperator NumericTypeCode " " +| "NEG_" SignedTypeCode " " +| "REM_" IntegerTypeCode "" +| "DUP_" TypeCode " " +| "CVT_" ConvertibleTypes " " +| "SHIFT_" UnsignedTypeCode "" INTEGER +| JumpInstruction " " Destination + +``` + +| | | | | | +|-----------------------|-----|------------------------------------------------------------|-----------------------------|--| +| | | UnaryInstruction " " Reference | | | +| | | "PUSHI " INTEGER | | | +| | | BinaryInstruction " " Reference INTEGER | | | +| | | "LABEL " STRING | // Label in routine code | | +| IntegerTypeCode | ::= | SignedIntegerTypeCode UnsignedTypeCode | | | +| SignedIntegerTypeCode | | ::= "S" "L" | | | +| SignedTypeCode | ::= | SignedIntegerTypeCode "F" "D" | | | +| UnsignedTypeCode | ::= | "O" "W" "U" | | | +| LogicalTypeCode | ::= | "B" UnsignedTypeCode | | | +| NumericTypeCode | ::= | SignedTypeCode UnsignedTypeCode | | | +| ComparisonTypeCode | ::= | NumericTypeCode "C" | | | +| ConvertibleTypes | ::= | "SW" "WS" "LU" "UL" "CW" "WC" "BS" "OS" | | | +| | | "SL" "LF" "WL" "UF" "FD" "BO" "OW" "SU" | | | +| | | "WU" "OB" "SB" "LB" "WB" "UB" "WO" "LS" | | | +| | | "FL" "UW" "FU" "DF" | | | +| TypeCode | ::= | ComparisonTypeCode "B" "I" "R" | | | +| Reference | ::= | INTEGER | // Identifier | | +| | | STRING | // Logical name or IDL name | | +| Destination | ::= | INTEGER | // Offset | | +| | | STRING | // Label | | +| SimpleInstruction | ::= | "EQR" "YIELD" "RET" "NOP" "FREE" | | | +| ComparisonOperator | ::= | "GT_" "LT_" | | | +| LogicalOperator | ::= | "AND_" "OR_" "XOR_" "NOT_" | | | +| ArithmeticOperator | ::= | "ADD_" "SUB_" "MUL_" "DIV_" | | | +| JumpInstruction | ::= | "JMP" "LJMP" "JT" "JF" "LJT" "LJF" | | | +| UnaryInstruction | ::= | "INC" "DEC" "PUSHR" "PUSH" "POPR" "POP" "POPC" | | | +| | | "GETOR" "ALLOC" "CALL" "XCALL" | | | +| BinaryInstruction | ::= | "SET" "SETC" "GET" "GETC" | | | + +## APPENDIX III + +### MHEG entities + +MHEG entities include MHEG objects, mh-objects, rt-objects, interchanged MHEG objects, sockets, channels. + +#### III.1 MHEG objects + +According to ITU-T Rec. T.172 (and ISO/IEC 13522-1) [5], an MHEG object is defined as a coded representation. Therefore, MHEG objects are bitstrings. The identity of an MHEG object is its bitstring. MHEG objects are "form 1" objects as described in ISO/IEC 13522-1 [5], subclause 6.2.4. MHEG object A and MHEG object B are identical if and only if they **are** the same sequence of bits. + +An MHEG object is not a physical object, but an abstraction (a specified sequence of bits) which may have many representations (i.e. different objects) of different types: interchanged MHEG objects, stored MHEG objects, mh-objects, etc. Such representations are handled by different software services. + +An MHEG object may be identified by an MHEG identifier. MHEG identifiers are the **only** way to identify MHEG objects. The structure and coded representation of MHEG identifiers is defined by ITU-T Rec. T.172 (and ISO/IEC 13522-1) [5]. The MHEG identifier of an MHEG object must be encoded inside the MHEG object. Since the attribute is optional, some MHEG objects do not have an MHEG identifier. Such MHEG objects cannot be identified. ITU-T Rec. T.172 (and ISO/IEC 13522-1) [5] imposes a constraint on the design of MHEG applications which is that MHEG object A and MHEG object B shall not have the same MHEG identifier unless they are identical. + +The MHEG generic reference describes all possible ways to reference an MHEG object. + +### **III.2 Mh-objects** + +An mh-object is an internal representation of an MHEG object within a process or system. An mh-object is not an MHEG object. Within an MHEG engine, mh-objects represent "available" MHEG objects. Mh-objects are "form 2" objects as described in ISO/IEC 13522-1 [5], subclause 6.2.4. An mh-object represents one MHEG object, i.e. there is always a bitstring that corresponds to an mh-object. An MHEG engine should not handle more than one mh-object to represent one MHEG object. + +As a consequence, mh-objects handled by MHEG engines may be identified using MHEG identifiers. In addition, other mechanisms for identifying mh-objects (e.g. symbolic identification) may be defined by the application, provided their internal representation allows for it. This is especially useful when some of the MHEG objects represented by an MHEG engine's mh-objects are non-identifiable, i.e. have no MHEG identifier. This allows to guarantee that all mh-objects are identifiable. + +Mh-objects are referenced the same way MHEG objects are. References to MHEG objects for which the MHEG engine handles an mh-object will usually be resolved by addressing this mh-object. + +### **III.3 Rt-objects** + +An rt-object is a run-time "instance" (or copy) of a "model" mh-object, which is created and handled by an MHEG engine in the purpose of presentation. An rt-object is not an MHEG object. Within an MHEG engine, rt-objects represent "rt-available" MHEG objects. Rt-objects are "form 3" objects as described in ISO/IEC 13522-1 [5], subclause 6.2.4. There may be none or several rt-objects which are "presentable" copies of one mh-object. An rt-object always has exactly one mh-object as its model. + +Rt-objects may be identified using rt-object identifiers whose "model object identification" component is an MHEG identifier. The structure and coded representation of rt-object identifiers is defined by ITU-T Rec. T.172 (and ISO/IEC 13522-1) [5]. In addition, other mechanisms for identifying rt-objects (e.g. symbolic identification) may be defined by the application, provided their internal representation allows for it. This is especially useful when some of the MHEG objects represented by an MHEG engine's mh-objects used as models for rt-objects are non-identifiable, i.e. have no MHEG identifier. This allows to ensure that all rt-objects are identifiable. + +Rt-objects may be referenced using MHEG generic references. + +### **III.4 Interchanged MHEG objects** + +Interchanged MHEG objects are representations of MHEG objects which are being communicated at a given point in time using a network or storage medium. One given MHEG object (i.e. bitstring) may be interchanged many times between many places, i.e. represented by many interchanged MHEG objects. An MHEG external identifier may identify an interchanged MHEG object, and + +therefore reference an MHEG object through its location and time of interchange. However, it should be noted that an MHEG external identifier need not actually identify an MHEG object. + +Stored MHEG objects are representations of MHEG objects which are usually located in files or database records. For instance, one given MHEG object (i.e. bitstring) may be stored in many places, i.e. represented by many stored MHEG objects. Such locations are usually identified using file names or database identifiers. An MHEG external identifier may identify a storage location for an MHEG object, and therefore reference an MHEG object through its storage location. + +## APPENDIX IV + +### **Main features of MHEG-SIR** + +This Recommendation has been developed in order to respond to a number of requirements and constraints regarding: + +- the applications that use it; +- the functionality that it provides; +- its context of use by applications; +- its performance. + +MHEG-SIR is endowed with the features described in this Appendix. + +#### **IV.1 Features of using applications** + +MHEG-SIR fits the requirements of applications that feature: + +- 1) manipulation of MHEG entities; +- 2) computations, variable handling and control structures; +- 3) external device control; +- 4) data acquisition; +- 5) access to external data; +- 6) access to arbitrary external run-time services. + +##### **IV.1.1 Manipulation of MHEG entities** + +Applications usually manipulate MHEG entities for the purpose of multimedia presentation. + +This feature is achieved through provision of the mechanisms described in IV.2.2. + +##### **IV.1.2 Computations, variable handling and control structures** + +Applications need these data processing features to implement advanced dynamic behaviour. + +These features are achieved through provision of the mechanisms described in IV.2.1. + +##### **IV.1.3 External device control** + +Devices often provide a platform-specific interface. Components of the execution platform that implement another Recommendation and its encapsulated monomedia standards usually support a number of devices. In addition, some applications need to control directly either these devices or other devices not otherwise supported. + +This feature is achieved through provision of the mechanisms described in IV.2.2. + +NOTE – In this context, a device driver is one service package that needs to be provided by the run-time environment. + +#### **IV.1.4 Data acquisition** + +Components of the execution platform that implement another Recommendation and its encapsulated monomedia standards usually support a number of data acquisition mechanisms. In addition, some applications need to control directly data acquisition (e.g. for finer tuning) from either these mechanisms or other mechanisms not otherwise supported. + +This feature is achieved through provision of the mechanisms described in IV.2.2. + +NOTE – In this context, acquired data can be retrieved by an rt-script via asynchronous reaction to notification messages sent by the driver of an external acquisition device. + +#### **IV.1.5 Access to external data** + +Some applications need to access non-MHEG data that have to be retrieved from local storage, from a stream or from a remote data repository using a communication component of the run-time environment. + +This feature is achieved through provision of the mechanisms described in IV.2.2. + +NOTE – In this context, external data can be retrieved through a system component that is one service package provided by the run-time environment. + +#### **IV.1.6 Access to arbitrary external run-time services** + +Arbitrary run-time services refer to all services whose interface definition is not known to the implementation before the application is interchanged. + +This feature is achieved through provision of the mechanisms described in IV.2.2. + +NOTE – In this context, external calculation capability may be provided by a library or process that is one service package provided by the run-time environment. + +### **IV.2 Functional features** + +MHEG-SIR is used to express: + +- 1) data processing operations (see IV.2.1); +- 2) access to external data and functions (see IV.2.2). + +#### **IV.2.1 Data processing operations** + +To support data processing operations, MHEG-SIR provides mechanisms used by interchanged scripts to express: + +- the structure of constructed and advanced numeric data types; +- variables and values of these types; +- instructions that perform data access or variable assignment; +- instructions that affect the script execution control flow; +- instructions that perform arithmetic, logical and comparison operators. + +These mechanisms are described in clauses 8, 12 and 13. + +## IV.2.2 Access to external data and functions + +Access to external data and functions requires co-operation among several components of the MHEG-3 engine and the run-time environment in order to invoke functions, send and receive messages and exchange data. + +To support manipulation of MHEG entities (i.e. access to MHEG data and functions), MHEG-SIR provides mechanisms used by interchanged scripts to: + +- invoke MHEG elementary actions; +- respond to MHEG actions targeted at the rt-script; +- express variables and values of MHEG data types. + +These mechanisms are described in clause 11. They are also used to express data interchange and synchronization either between the rt-script and other rt-objects or among rt-scripts. + +To support co-operation with the run-time environment (i.e. access to non-MHEG data and functions), MHEG-SIR provides mechanisms used by interchanged scripts to: + +- declare the structure of packages provided by the run-time environment; +- invoke services provided by the run-time environment; +- react to messages sent by the run-time environment; +- declare constructed and advanced numeric data types; +- express variables and values of these types. + +These mechanisms are described in clause 10. They also express interchange of complex data and synchronization between the MHEG-SIR script interpreter and processes that are part of the run-time environment. + +In addition, this Recommendation defines the mapping of MHEG-SIR package declarations to actual run-time environment components. This is done in two steps: + +- Expression and use of an abstract interface specification by MHEG-SIR: this is the IDL mapping mechanism described in clause 14. It consists of provisions for MHEG-3 interchanged scripts. +- Mapping between an abstract interface specification and its implementation within the run-time environment of a type of platform: this is the platform mapping specification form described in Annex D. It consists of provisions for MHEG-3 implementations. + +## IV.3 Technical features + +The MHEG-SIR meets the following technical requirements: + +- 1) hardware independence; +- 2) final form representation; +- 3) compactness; +- 4) ease of implementation; +- 5) interpretation efficiency; +- 6) openness and extensibility; +- 7) non-revisability; +- 8) provisions for real-time interchange; +- 9) semantic validation for quality of service purposes; +- 10) syntax checkability (with regard to contamination hazards); + +- 11) non-proprietary representation; +- 12) secure script processing. + +#### **IV.3.1 Hardware independence** + +Hardware independence of MHEG-SIR, and therefore portability of interchanged scripts, is achieved through the definition of a virtual machine code to express interchanged scripts and the definition of a virtual machine to interpret this code. Only typed data are used. There is no requirement on the way data are represented or handled internally by MHEG-3 engines. + +The coded representation is based on ASN.1 encoding rules, which are hardware-independent. + +The interface declarations are based on a mapping to abstract interface specifications that can be expressed using IDL, which is hardware-independent. + +The capability for a component of the run-time environment of a given platform to interoperate with any conforming MHEG-3 engine on this platform is guaranteed through the use of the platform mapping specification. + +The capability for an MHEG-3 engine implementation on a given platform to interoperate with any service provider within the run-time environment is guaranteed through the use of the platform mapping specification, provided such service providers conform to this specification. + +#### **IV.3.2 Final form representation** + +Final form representation of interchanged scripts is achieved through: + +- the use of ASN.1 for the encoding of interchanged scripts; +- a virtual machine encoding that is semantically close to a broad class of general purpose computers; +- a stack machine architecture which has an efficient instruction encoding based on implied addressing mode; +- an ordering of declarations that reduces overhead for processing of forward references; +- the appropriate sequencing of instructions within a routine. + +#### **IV.3.3 Compactness** + +Compactness of the coded representation of interchanged scripts is achieved through several optimizations: + +- the definition of a stack machine-based virtual machine code allows instructions to have few or no operands, the longest MHEG-SIR instruction taking 4 bytes to encode; +- use of bytestream coding for the routines code is used to elude the overhead induced by TLV coding; +- instructions are packed (i.e. have no padding bytes) in the encoding of the routines code; +- constants are used for the declaration of immediate values; +- predefined codes are defined for MHEG types, operations and messages; +- the declaration of a handler definition table is used to optimize the expression of the mapping between messages targeted at the script and routines intended to handle these messages. + +#### **IV.3.4 Ease of implementation** + +Ease of implementation of MHEG-SIR script interpreters is achieved through: + +- the definition of a reduced instruction set; +- the clear definition of a virtual machine; +- the limited number of concepts and identifiers that script interpreters need to handle; +- the formal definition of instruction semantics. + +#### **IV.3.5 Interpretation efficiency** + +Efficiency of interpretation of interchanged scripts by MHEG-SIR script interpreters is achieved through: + +- the use of a stack-based virtual machine code; +- the use of low-level instructions; +- the use of a final form representation. + +#### **IV.3.6 Openness and extensibility** + +Openness and extensibility of MHEG-SIR is achieved through: + +- a generic definition of the interfaces that may be accessed from MHEG-SIR script code; +- the capability to access MHEG objects and to invoke routines from another rt-script; +- the possibility to add new instructions to the representation without modifying the structure of interchanged scripts. + +#### **IV.3.7 Non-revisability** + +Non-revisability is achieved through the use of a final form, low-level representation. This representation is for production via specialized computer tools and does not allow easy reversion to the original source code as designed by humans using scripting languages and/or authoring environments, and thus limits the risk of undue alteration of the program semantics. + +#### **IV.3.8 Provisions for real-time interchange** + +The MHEG-SIR fits within the framework of MHEG whose general structure has been designed to meet real-time interchange requirements. + +The syntax of interchanged scripts is defined so as to optimize the possibility of treating the declarations it contains "on the fly". + +Moreover, the use of ASN.1 encoding allows to detect errors (to some extent) while interchanging scripts in noisy network environments. + +#### **IV.3.9 Semantic validation for quality of service purposes** + +Due to the requirements posed by this Recommendation on semantics, the behaviour of an interchanged script can be tested in order to validate its performance before it is actually used in the context of a commercial service. MHEG-SIR script interpreters can be built to serve as a reference with regard to the way conforming MHEG-3 engines should behave when interpreting the interchanged scripts under test. + +#### **IV.3.10 Syntax checkability (with regard to contamination hazards)** + +The formal definition of the MHEG-SIR syntax can be used to check its correctness and therefore prevent the interchange of pieces of code such as viruses intended to damage the receiving system in + +some way. Implementations may decide to perform syntactic and semantic checks at run-time and/or at load-time. + +NOTE – The design of MHEG-SIR as an interpreted, machine-independent representation reduces contamination risk. Residual risk may come from non-certified or otherwise incorrect implementations. The provision of encryption, authentication and other security mechanisms at the transport level is outside the scope of this Recommendation. + +#### **IV.3.11 Non-proprietary representation** + +This Recommendation follows the intellectual property rights policy of international standardization bodies. For further details, please refer to the statement on "Intellectual Property Rights" indicated at the beginning of this Recommendation. + +#### **IV.3.12 Secure script processing** + +A system designer may wish to insure that faulty script execution, intentional or accidental, will have minimal impact on the delivery system, and that all access to external services can be carefully monitored. The MHEG-SIR virtual machine includes a number of features which support this goal: + +- explicit, strongly-typed interfaces to all external services; +- a strongly-typed instruction set, so that operations and operands may be verified either by pre-processing or by run-time checking; +- no direct addressing of memory (i.e. no pointer arithmetic), preventing the possibility of spurious side effects; +- isolation of context for each rt-script object; +- isolation of contexts defined by each call frame; +- no direct manipulation of handles, type identifiers or data identifiers. + + + +## ITU-T RECOMMENDATIONS SERIES + +| | | +|-----------------|--------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of the ITU-T | +| Series B | Means of expression: definitions, symbols, classification | +| Series C | General telecommunication statistics | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks and open system communication | +| Series Z | Programming languages | \ No newline at end of file diff --git a/marked/T/T-REC-T.175-199802-I_PDF-E/raw.md b/marked/T/T-REC-T.175-199802-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..277489a5672ff81867652bec39e97670c08151c5 --- /dev/null +++ b/marked/T/T-REC-T.175-199802-I_PDF-E/raw.md @@ -0,0 +1,1690 @@ + + +![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# T.175 + +(02/98) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES + +--- + +# **Application Programming Interface (API) for MHEG-5** + +ITU-T Recommendation T.175 + +(Previously CCITT Recommendation) + +--- + +# ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES** + +![A large empty rectangular box with a double border.](c803f6f6e2c49429d2951832bd0f208d_img.jpg) + +A large empty rectangular box with a double border, likely intended for a diagram or additional text related to the terminal services. + +A large empty rectangular box with a double border. + +*For further details, please refer to ITU-T List of Recommendations.* + +## **ITU-T RECOMMENDATION T.175** + +# **APPLICATION PROGRAMMING INTERFACE (API) FOR MHEG-5** + +## **Summary** + +This Recommendation specifies the Application Programming Interface (API) for the manipulation of multimedia and hypermedia information objects. + +MHEG part 5 (Recommendation T.172) is a standard, which specifies the coded representation of interchanged multimedia/hypermedia information objects (MHEG-5 objects) for base-level applications. These so-called MHEG-5 objects are handled, interpreted and presented by MHEG-5 engines. + +## **Source** + +ITU-T Recommendation T.175 was prepared by ITU-T Study Group 16 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 6th of February 1998. + +## FOREWORD + +ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +## INTELLECTUAL PROPERTY RIGHTS + +The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. + +© ITU 1998 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +## CONTENTS + +| | Page | +|-------------------------------------------------------------------------|-------------| +| 1 Scope..... | 1 | +| 2 Normative references ..... | 1 | +| 3 Definitions and abbreviations ..... | 1 | +| 3.1 Definitions ..... | 1 | +| 3.2 Abbreviations..... | 2 | +| 4 Overview..... | 2 | +| 4.1 The DAVIC application interchange format..... | 2 | +| 4.2 Core set of Java APIs..... | 3 | +| 5 The MHEG-5 API..... | 4 | +| 6 Map between MHEG-5 elementary actions and MHEG-5 API operations ..... | 22 | + + + +## Recommendation T.175 + +# APPLICATION PROGRAMMING INTERFACE (API) FOR MHEG-5 + +(Geneva, 1998) + +# 1 Scope + +This Recommendation specifies the Application Programming Interface (API) for the manipulation of multimedia and hypermedia information objects, i.e. the API that shall be provided by MHEG-5 engines for their control by applications running on a DAVIC 1.1 compliant terminal. + +MHEG part 5 (Recommendation T.172) is a standard, which specifies the coded representation of interchanged multimedia/hypermedia information objects (MHEG-5 objects) for base-level applications. These so-called MHEG-5 objects are handled, interpreted and presented by MHEG-5 engines. + +# 2 Normative references + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. + +- [1] ISO/IEC 13522-5: 1997, *Information technology – Coding of multimedia and hypermedia information – Part 5: Support for base-level interactive applications.* +- [2] ETS 300 777-1, *Terminal Equipment (TE); End-to-end protocols for multimedia information retrieval services; Part 1: Coding of multimedia and hypermedia information for basic multimedia applications (MHEG-5).* +- [3] ETS 300 777-2, *Terminal Equipment (TE); End-to-end protocols for multimedia information retrieval services; Part 2: Use of Digital Storage Media Command and Control (DSM-CC) for basic multimedia applications.* +- [4] ISO/IEC DIS 13522-6, *Information technology – Coding of multimedia and hypermedia information – Part 6: Support for enhanced interactive applications.* + +# 3 Definitions and abbreviations + +## 3.1 Definitions + +For the purposes of this Recommendation the definition of the standards referenced below apply. Should any ambiguity occur, definitions of the following standards apply, in decreasing order: + +- ISO/IEC 13522-5 [1] MHEG-5; +- any other standard part of ISO/IEC 13522 MHEG. + +**3.1.1 Application Programming Interface (API):** A boundary across which a software application uses facilities of programming languages to invoke software services. These facilities may include procedures or operations, shared data objects and resolution of identifiers. + +**3.1.2 local application:** A piece of software which is part of the (telecommunication) application and is running on the considered equipment. + +**3.1.3 MHEG-5 API:** The API provided by an MHEG-5 engine to local applications for the manipulation of MHEG-5 objects, as defined in this Recommendation. + +**3.1.4 MHEG-5 engine:** A process or a set of processes that interpret MHEG-5 objects encoded according to the encoding specifications of ETS 300 777-1 [2] or the MHEG-5 textual notation. + +## 3.2 Abbreviations + +This Recommendation uses the following abbreviations: + +| | | +|--------|------------------------------------------------------------| +| API | Application Programming Interface | +| ASN.1 | Abstract Syntax Notation One | +| DAVIC | Digital Audio Visual Council | +| DSM-CC | Digital Storage Media Command and Control | +| EBNF | Extended Backus-Naur Form | +| JTC | Joint Technical Committee | +| MHEG | Multimedia and Hypermedia information coding Experts Group | +| SI | Service Information | +| STU | Set Top Unit | +| VM | Virtual Machine | + +# 4 Overview + +The following subclause positions the API defined by this Recommendation in the framework of the DAVIC specifications. + +## 4.1 The DAVIC application interchange format + +To deliver multimedia information to STUs in an interoperable way, applications shall use the MHEG-5 final form interchange format, as defined by ISO/IEC 13522-5 [1]. The ASN.1 notation and encoding, as defined by ETS 300 777-1 [2], shall be used to interchange MHEG-5 objects. This format defines the semantics and the encoding of the multimedia and hypermedia objects. + +To deliver program code to STUs in an interoperable way, applications shall use the MHEG-5 InterchangedProgram class to encapsulate Java1 VM code, according to the semantics and encoding defined by ISO/IEC DIS 13522-6 [4]. Java VM classes are called from MHEG-5 objects using the MHEG-5 Call and Fork elementary actions. + +The Java VM code interchange unit is a Java VM class. Java VM classes shall be encoded as defined by the *Class File Format* section of the *Java Virtual machine specification*. A Java class encapsulates data and methods that consist of sequences of instructions. The instruction set is defined by the *Java Virtual machine instruction set* section of the *Java Virtual machine specification*. + +--- + +1 Java is a trademark or a registered trademark of Sun Microsystems, Inc. + +## 4.2 Core set of Java APIs + +The following set of APIs are used by Java VM code in the DAVIC 1.1 specifications to express access to basic functions of the STU in an interoperable way: + +- the `java.lang` package; +- the `java.util` package; +- the `iso.mheg5` package; +- the `davic.dsmccuu` package; +- the `etsi.si` package. + +NOTE 1 – The Java VM specification provides flexible mechanisms to call upon external functions whose interface is defined as a Java package. The DAVIC 1.1 specification only includes a minimum core set of packages required for Java VM code to be useful in a DAVIC environment. It is anticipated that additional Java packages will be standardised at a later stage. + +NOTE 2 – Especially, the `java.io` package, although strictly speaking not necessary to the useful performance of the VM environment, is part of the Java foundation classes. It is intended that the `java.io` package be added to the DAVIC core set of Java APIs together with an adequate specification of its semantics in a DAVIC environment. + +The `java.lang` package, as defined by the *Java API documentation*, consists of the minimal set of Java VM classes needed to run Java VM code, supporting the following functionality: basic data types, object, mathematic operations, security, thread management, string manipulation, exception handling. + +The `java.util` package, as defined by the *Java API documentation*, consists of Java VM classes supporting a number of utility features common to all Java VM programs. + +The `iso.mheg5` package, as defined by this Recommendation, provides Java VM code with access to and manipulation of the MHEG-5 multimedia presentation and interaction objects, i.e. access to the dynamic attributes of MHEG-5 objects and invocation of elementary actions on MHEG-5 objects. + +The `davic.dsmccuu` package, together with the associated `davic.CosNaming` and `davic.CosNaming.NamingContext_` packages, as defined by ETS 300 777-2 [3], enables Java VM code to use the DSM-CC U-U interface objects for network data access. + +The `davic.dsmccuu` package implements a subset of the DSM-CC U-U API. Access to the following Core SetTop services is provided: + +- interface Base: operations Close and Destroy; +- interface File: operations Read and Write; +- interface Directory: operations Open, Close and Get; +- interface ServiceGateway: operations Attach and Detach; +- interface CosNaming::NamingContext: operations List and Resolve; +- interface CosNaming::BindingIterator: operations Next\_One and Next\_N. + +The `etsi.si` package enables Java VM code to access information transmitted in the DAVIC Service Information (SI) stream. + +# 5 The MHEG-5 API + +``` +// ----- +// Package +// ----- +package iso.mheg5; +// ----- +// Useful definitions +// ----- +public class                      +{ + /* Attributes */ + // The groupIdIdentifier attribute is optional (it may be empty) + public byte[] groupIdIdentifier; + public int objectNumber; + + /* Constructors */ + public ObjectReference(); + public ObjectReference( + int objectNumber); + public ObjectReference( + byte[] groupIdIdentifier, + int objectNumber); +} +// ----- +public class                      +{ + /* Attributes */ + byte[] reference; + + /* Constructors */ + public ContentReference(); + public ContentReference( + byte[] reference); +} +// ----- +public class                      extends java.lang.Exception +{ + /* Attributes */ + // Constant declarations for exceptionCode + public static final short TARGET_NOT_AVAILABLE = 1; + public static final short INVALID_TARGET = 2; + public static final short INVALID_PARAMETER = 3; + + public short exceptionCode; + public short parameterRank; + + /* Constructors */ + protected MhegException(); + + // Construct an MhegException with exceptionCode identified by the reason + // parameter + public MhegException( + short reason) + { + exceptionCode = reason; + parameterRank = -1; + } +} +``` + +``` + +// Construct an MhegException with exceptionCode identified by the reason +// parameter and parameterRank by the position parameter + public MhegException( + short reason, + short position) + { + exceptionCode = reason; + parameterRank = position; + } +} + +// ----- +abstract public class □□□□ +{ + /* Constructors */ + protected Root(); + + /* Methods */ + // Return the reference of the Java object associated with the MHEG-5 object + // whose identification is mheg5ObjectReference + // If the Java object does not exist, create it first + public static final Root getObject( + ObjectReference mheg5ObjectReference) + throws MhegException; + + // Correspond to the GetAvailabilityStatus MHEG-5 elementary action + public Boolean getAvailabilityStatus() + throws MhegException; + + // Correspond to the GetRunningStatus MHEG-5 elementary action + public Boolean getRunningStatus() + throws MhegException; + +} + +// ----- +abstract public class □□□□□ extends Root +{ + /* Constructors */ + protected Group(); + + /* Methods */ + // Correspond to the SetCachePriority MHEG-5 elementary action + // The cachePriority parameter value shall be within the range [0,255] + public void setCachePriority( + byte cachePriority) + throws MhegException; + + // Retrieve the value of the GroupCachePriority attribute + public Integer getCachePriority() + throws MhegException; + +} + +// ----- +public class □□□□□□□□□□ extends Group +{ + /* Constructors */ + protected Application(); + + /* Methods */ + // Correspond to the LockScreen MHEG-5 elementary action + public void lockScreen() + throws MhegException; + + // Correspond to the UnlockScreen MHEG-5 elementary action + public void unlockScreen() + throws MhegException; +} + +``` + +``` + +// Retrieve the value of the LockCount attribute +// The wrapped returned value shall be positive or equal to zero + public Integer getLockCount() + throws MhegException; + +// Correspond to the GetEngineSupport MHEG-5 elementary action + public Boolean getEngineSupport(byte[] feature) + throws MhegException; + +} + +// ----- +public class □□□□□ extends Group +{ + +/* Constructors */ + protected Scene(); + +/* Methods */ + +// Correspond to the TransitionTo MHEG-5 elementary action + public void transitionTo() + throws MhegException; + public void transitionTo( + int connectionTag) + throws MhegException; + public void transitionTo( + byte transitionEffect) + throws MhegException; + public void transitionTo( + int connectionTag, + byte transitionEffect) + throws MhegException; + +// Correspond to the SetTimer MHEG-5 elementary action + public void setTimer( + int timerId) + throws MhegException; + public void setTimer( + int timerId, + int timerValue) + throws MhegException; + public void setTimer( + int timerId, + int timerValue, + boolean absoluteTime) + throws MhegException; + +// Retrieve the value of the TimerPosition (in the timerPosition parameter) and +// AbsoluteTime (in the absoluteTime parameter) fields of the timer whose +// identification is timerId in the Timers attribute +// If the targetted timer exists, the method returns true otherwise false + public boolean getTimer( + int timerId, + Integer timerPosition, + Boolean absoluteTime) + throws MhegException; + +// Correspond to the SendEvent MHEG-5 elementary action + public void sendEvent( + ObjectReference eventSource, + byte eventType) + throws MhegException; + public void sendEvent( + ObjectReference eventSource, + byte eventType, + boolean eventData) + throws MhegException; + +``` + +``` + + public void sendEvent( + ObjectReference eventSource, + byte eventType, + int eventData) + throws MhegException; + public void sendEvent( + ObjectReference eventSource, + byte eventType, + byte[] eventData) + throws MhegException; + +// Correspond to the SetCursorShape MHEG-5 elementary action + public void setCursorShape() + throws MhegException; + public void setCursorShape( + ObjectReference cursorShape) + throws MhegException; + +// Retrieve the shape of the cursor +// A returned null object reference indicates that the cursor has been removed +// from the scene + public ObjectReference getCursorShape() + throws MhegException; + +// Correspond to the SetCursorPosition MHEG-5 elementary action + public void setCursorPosition( + short xCursor, + short yCursor) + throws MhegException; + +// Correspond to the GetCursorPosition MHEG-5 elementary action + public void getCursorPosition( + Integer xCursor, + Integer yCursor) + throws MhegException; + +} + +// ----- +abstract public class □□□□□□□□□□ extends Root +{ + +/* Constructors */ + protected Ingredient(); + +/* Methods */ + +// Correspond to the SetData MHEG-5 elementary action + public void setData( + byte[] includedContent) + throws MhegException; + public void setData( + ContentReference referencedContent) + throws MhegException; + public void setData( + ContentReference referencedContent, + int contentSize) + throws MhegException; + public void setData( + ContentReference referencedContent, + byte contentCachePriority) + throws MhegException; + public void setData( + ContentReference referencedContent, + int contentSize, + byte contentCachePriority) + throws MhegException; + +``` + +``` + +// Retrieve the value of the ContentData attribute +// The returned value shall be true and content shall be of type byte[] for an +// included content +// The returned value shall be false and content shall be of type +// ContentReference for a referenced content +// contentSize and contentCachePriority are output parameters which are valid +// only for a referenced content + public boolean getData( + Object content, + Integer contentSize, + Integer contentCachePriority) + throws MhegException; + +// Correspond to the Clone MHEG-5 elementary action + public ObjectReference clone() + throws MhegException; + +// Correspond to the Preload MHEG-5 elementary action + public void preload() + throws MhegException; + +// Correspond to the Unload MHEG-5 elementary action + public void unload() + throws MhegException; + +} + +// ----- +public class □□□□ extends Ingredient +{ + /* Constructors */ + protected Link(); + + /* Methods */ + +// Correspond to the Activate MHEG-5 elementary action + public void activate() + throws MhegException; + +// Correspond to the Deactivate MHEG-5 elementary action + public void deactivate() + throws MhegException; + +} + +// ----- +public class □□□□□□□□ extends Ingredient +{ + /* Constructors */ + protected Program(); + + /* Methods */ + +// Correspond to the Call MHEG-5 elementary action +// Every element of the parameters array shall be of one of the following types: +// Boolean, Integer, byte[],ObjectReference or ContentReference; otherwise, an +// exception is raised + public boolean call( + Object[] parameters) + throws MhegException; + +// Correspond to the Fork MHEG-5 elementary action +// Every element of the parameters array shall be of one of the following types: +// Boolean, Integer, byte[],ObjectReference or ContentReference; otherwise, an +// exception is raised + public boolean fork( + Object[] parameters) + throws MhegException; + +// Correspond to the Stop MHEG-5 elementary action + public void stop() + throws MhegException; + +``` + +``` + +} +// ----- +public class ██████████ extends Program +{ + /* Constructors */ + protected ResidentProgram(); +} +// ----- +public class ██████████ extends Program +{ + /* Constructors */ + protected RemoteProgram(); +} +// ----- +public class ████████████████████ extends Program +{ + /* Constructors */ + protected InterchangedProgram(); +} +// ----- +public class ████████ extends Ingredient +{ + /* Constructors */ + protected Palette(); +} +// ----- +public class ████ extends Ingredient +{ + /* Constructors */ + protected Font(); +} +// ----- +public class ████████████████ extends Ingredient +{ + /* Constructors */ + protected CursorShape(); +} +// ----- +public class ██████████ extends Ingredient +{ + /* Constructors */ + protected Variable(); +} +// ----- +public class ████████████████████ extends Variable +{ + /* Constructors */ + protected BooleanVariable(); + /* Methods */ + +``` + +``` + +// Correspond to the SetVariable MHEG-5 elementary action targetted at a +// BooleanVariable object + public void setVariable( + boolean value) + throws MhegException; + +// Retrieve the value of the variable + public Boolean getVariable() + throws MhegException; + +} + +// ----- +public class □□□□□□□□□□□□□□□□ extends Variable +{ + /* Constructors */ + protected IntegerVariable(); + + /* Methods */ + +// Correspond to the SetVariable MHEG-5 elementary action targetted at an +// IntegerVariable object + public void setVariable( + int value) + throws MhegException; + +// Retrieve the value of the variable + public Integer getVariable() + throws MhegException; + +// Correspond to the Add MHEG-5 elementary action + public void add( + int value) + throws MhegException; + +// Correspond to the Subtract MHEG-5 elementary action + public void subtract( + int value) + throws MhegException; + +// Correspond to the Multiply MHEG-5 elementary action + public void multiply( + int value) + throws MhegException; + +// Correspond to the Divide MHEG-5 elementary action + public void divide( + int value) + throws MhegException; + +// Correspond to the Modulo MHEG-5 elementary action + public void modulo( + int value) + throws MhegException; + +} + +// ----- +public class □□□□□□□□□□□□□□□□ extends Variable +{ + /* Constructors */ + protected OctetStringVariable(); + + /* Methods */ + +// Correspond to the SetVariable MHEG-5 elementary action targetted at an +// OctetStringVariable object + public void setVariable( + byte[] value) + throws MhegException; + +``` + +``` + +// Retrieve the value of the variable + public byte[] getVariable() + throws MhegException; + +// Correspond to the Append MHEG-5 elementary action + public void append( + byte[] value) + throws MhegException; + +} + +// ----- +public class ████████████████████ extends Variable +{ + /* Constructors */ + protected ObjectRefVariable(); + + /* Methods */ +// Correspond to the SetVariable MHEG-5 elementary action targetted at an +// ObjectRefVariable object + public void setVariable( + ObjectReference value) + throws MhegException; + +// Retrieve the value of the variable + public ObjectReference getVariable() + throws MhegException; + +} + +// ----- +public class ████████████████████ extends Variable +{ + /* Constructors */ + protected ContentRefVariable(); + + /* Methods */ +// Correspond to the SetVariable MHEG-5 elementary action targetted at an +// ContentRefVariable object + public void setVariable( + ContentReference value) + throws MhegException; + +// Retrieve the value of the variable + public ContentReference getVariable() + throws MhegException; + +} + +// ----- +abstract public class ████████████████ extends Ingredient +{ + /* Constructors */ + protected Presentable(); + + /* Methods */ +// Correspond to the Run MHEG-5 elementary action + public void run() + throws MhegException; + +// Correspond to the Stop MHEG-5 elementary action + public void stop() + throws MhegException; + +} + +// ----- +public interface ████████████████ +{ + /* Methods */ + +``` + +``` + +// Correspond to the Move MHEG-5 elementary action + public void move( + short movementId) + throws MhegException; + +// Correspond to the MoveTo MHEG-5 elementary action +// The index parameter value shall be within the range [0, number of elements in +// the group] + public void moveTo( + short index) + throws MhegException; + +// Correspond to the GetTokenPosition MHEG-5 elementary action + public Integer getTokenPosition() + throws MhegException; + +} + +// ----- +public class □□□□□□□□□□ extends Presentable implements TokenManager +{ +/* Constructors */ + protected TokenGroup(); + +/* Methods */ +// Correspond to the implementation of the TokenManager.move method + public void move( + short movementId) + throws MhegException; + +// Correspond to the implementation of the TokenManager.moveTo method +// The index parameter value shall be within the range [0, number of elements in +// the group] + public void moveTo( + short index) + throws MhegException; + +// Correspond to the implementation of the TokenManager.getTokenPosition method + public Integer getTokenPosition() + throws MhegException; + +// Correspond to the CallActionSlot MHEG-5 elementary action +// The index parameter value shall be within the range [0, number of elements in +// the group] + public void callActionSlot( + short index) + throws MhegException; + +} + +// ----- +public class □□□□□□□□□□ extends TokenGroup +{ +/* Constructors */ + protected ListGroup(); + +/* Methods */ +// Correspond to the AddItem MHEG-5 elementary action + public void addItem( + short itemIndex, + ObjectReference visibleReference) + throws MhegException; + +// Correspond to the DelItem MHEG-5 elementary action + public void delItem( + ObjectReference visibleReference) + throws MhegException; + +``` + +``` + +// Correspond to the GetListItem MHEG-5 elementary action + public ObjectReference getListItem( + short itemIndex) + throws MhegException; +// Correspond to the GetCellItem MHEG-5 elementary action + public ObjectReference getCellItem( + short cellIndex) + throws MhegException; +// Correspond to the GetItemStatus MHEG-5 elementary action + public Boolean getItemStatus( + short itemIndex) + throws MhegException; +// Correspond to the SelectItem MHEG-5 elementary action + public void selectItem( + short itemIndex) + throws MhegException; +// Correspond to the DeselectItem MHEG-5 elementary action + public void deselectItem( + short itemIndex) + throws MhegException; +// Correspond to the ToggleItem MHEG-5 elementary action + public void toggleItem( + short itemIndex) + throws MhegException; +// Correspond to the ScrollItems MHEG-5 elementary action + public void scrollItems( + short itemsToScroll) + throws MhegException; +// Correspond to the SetFirstItem MHEG-5 elementary action + public void setFirstItem( + short itemIndex) + throws MhegException; +// Correspond to the getFirstItem MHEG-5 elementary action + public Integer getFirstItem() + throws MhegException; +// Correspond to the getListSize MHEG-5 elementary action + public Integer getListSize() + throws MhegException; +} + +// ----- +abstract public class □□□□□□ extends Presentable +{ + /* Constructors */ + protected Visible(); + /* Methods */ +// Correspond to the SetPosition MHEG-5 elementary action + public void setPosition( + short xPosition, + short yPosition) + throws MhegException; +// Correspond to the GetPosition MHEG-5 elementary action + public void getPosition( + Integer xPosition, + Integer yPosition) + throws MhegException; + +``` + +``` + +// Correspond to the SetBoxSize MHEG-5 elementary action +// The xBoxSize and yBoxSize parameter values shall be positive and different +// from zero + public void setBoxSize( + short xBoxSize, + short yBoxSize) + throws MhegException; + +// Correspond to the GetBoxSize MHEG-5 elementary action + public void getBoxSize( + Integer xBoxSize, + Integer yBoxSize) + throws MhegException; + +// Correspond to the BringToFront MHEG-5 elementary action + public void bringToFront() + throws MhegException; + +// Correspond to the SendToBack MHEG-5 elementary action + public void sendToBack() + throws MhegException; + +// Correspond to the PutBefore MHEG-5 elementary action + public void putBefore( + ObjectReference visibleReference) + throws MhegException; + +// Correspond to the PutBehind MHEG-5 elementary action + public void putBehind( + ObjectReference visibleReference) + throws MhegException; + +// Correspond to the SetPaletteRef MHEG-5 elementary action + public void setPaletteRef( + ObjectReference paletteReference) + throws MhegException; + +// Retrieve the value of the PaletteRef attribute + public ObjectReference getPaletteRef() + throws MhegException; + +} + +// +public class □□□□□□ extends Visible +{ + /* Constructors */ + + protected Bitmap(); + + /* Methods */ + +// Correspond to the ScaleBitmap MHEG-5 elementary action +// The xScale and yScale parameter values shall be positive and different from +// zero + public void scaleBitmap( + short xScale, + short yScale) + throws MhegException; + +// Correspond to the SetTransparency MHEG-5 elementary action +// The transparency parameter value shall be within the range [0,100] + public void setTransparency( + byte transparency) + throws MhegException; + +// Retrieve the value of the Transparency attribute + public Integer getTransparency() + throws MhegException; + +} + +// +public class □□□□□□□□ extends Visible +{ + +``` + +``` + +/* Constructors */ + protected LineArt(); +/* Methods */ +// Correspond to the SetLineWidth MHEG-5 elementary action +// The lineWidth parameter value shall be positive and different from zero + public void setLineWidth( + byte lineWidth) + throws MhegException; +// Correspond to the SetLineStyle MHEG-5 elementary action +// The lineStyle parameter value shall be 1 for solid, 2 for dashed, 3 for dotted + public void setLineStyle( + byte lineStyle) + throws MhegException; +// Correspond to the SetLineColour MHEG-5 elementary action + public void setLineColour( + byte colourIndex) + throws MhegException; + public void setLineColour( + byte[] absoluteColour) + throws MhegException; +// Correspond to the SetFillColour MHEG-5 elementary action +// When neither a colour index nor an absolute colour is specified, the fill-in +// colour shall be set to transparent + public void setFillColour() + throws MhegException; + public void setFillColour( + byte colourIndex) + throws MhegException; + public void setFillColour( + byte[] absoluteColour) + throws MhegException; +} +// ----- +public class □□□□□□□□ extends LineArt +{ +/* Constructors */ + protected Rectangle(); +} +// ----- +public class □□□□□□□□□□□□□□ extends LineArt +{ +/* Constructors */ + protected DynamicLineArt(); +/* Methods */ +// Correspond to the GetLineWidth MHEG-5 elementary action + public Integer getLineWidth() + throws MhegException; +// Correspond to the GetLineStyle MHEG-5 elementary action + public Integer getLineStyle() + throws MhegException; +// Correspond to the GetLineColour MHEG-5 elementary action +// The returned value shall be of one of the following types: Integer (in which +// case it represents an index) or byte[] (in which case it represents the +// absolute colour) + public Object getLineColour() + throws MhegException; + +``` + +``` + +// Correspond to the GetFillColour MHEG-5 elementary action +// The returned value shall be of one of the following types: Integer (in which +// case it represents an index) or byte[] (in which case it represents the +// absolute colour); a returned null object reference indicates no fill-in colour +// (transparent) + public Object getFillColour() + throws MhegException; + +// Correspond to the DrawArc MHEG-5 elementary action + public void drawArc( + short x, + short y, + short ellipseWidth, + short ellipseHeight, + short startAngle, + short arcAngle) + throws MhegException; + +// Correspond to the DrawSector MHEG-5 elementary action + public void drawSector( + short x, + short y, + short ellipseWidth, + short ellipseHeight, + short startAngle, + short arcAngle) + throws MhegException; + +// Correspond to the DrawLine MHEG-5 elementary action + public void drawLine( + short x1, + short y1, + short x2, + short y2) + throws MhegException; + +// Correspond to the DrawOval MHEG-5 elementary action + public void drawOval( + short x, + short y, + short ellipseWidth, + short ellipseHeight) + throws MhegException; + +// Correspond to the DrawPolygon MHEG-5 elementary action + public void drawPolygon( + short[][] pointList) + throws MhegException; + +// Correspond to the DrawPolyline MHEG-5 elementary action + public void drawPolyline( + short[][] pointList) + throws MhegException; + +// Correspond to the DrawRectangle MHEG-5 elementary action + public void drawRectangle( + short x1, + short y1, + short x2, + short y2) + throws MhegException; + +// Correspond to the Clear MHEG-5 elementary action + public void clear() + throws MhegException; + +} + +// ----- +public class □□□□ extends Visible +{ + +``` + +``` + +/* Constructors */ + protected Text(); + +/* Methods */ +// Correspond to the GetTextContent MHEG-5 elementary action +// The returned value shall be of one of the following types: ContentReference +// (in which case it represents a reference to the content) or byte[] (in which +// case it represents the actual content) + public Object getTextContent() + throws MhegException; + +// Correspond to the GetTextData MHEG-5 elementary action + public byte[] getTextData() + throws MhegException; + +// Correspond to the SetFontRef MHEG-5 elementary action + public void setFontRef( + byte[] fontName) + throws MhegException; + public void setFontRef( + ObjectReference fontReference) + throws MhegException; + +// Retrieve the value of the Font attribute +// The returned value shall be of one of the following types: ObjectReference (in +// which case it represents a reference to an MHEG-5 Font object) or byte[] (in +// which case it represents a resident font name); a returned null object +// reference indicates the default font + public Object getFontRef() + throws MhegException; + +} + +// ----- +public class □□□□□□ extends Presentable +{ +/* Constructors */ + protected Stream(); + +/* Methods */ +// Correspond to the SetCounterTrigger MHEG-5 elementary action +// When the counter value is not specified, the targetted trigger shall be +// removed + public void setCounterTrigger( + short triggerIdentifier) + throws MhegException; + public void setCounterTrigger( + short triggerIdentifier, + byte counterValue) + throws MhegException; + +// Retrieve the value of the CounterPosition field of the trigger whose +// identification is triggerIdentifier in the CounterTriggers attribute; a +// returned null object reference indicates that the targetted trigger does not +// exist + public Integer getCounterTrigger( + short triggerIdentifier) + throws MhegException; + +// Correspond to the SetSpeed MHEG-5 elementary action + public void setSpeed( + byte nominator) + throws MhegException; + public void setSpeed( + byte nominator, + byte denominator) + throws MhegException; + +``` + +``` + +// Retrieve the value of the Speed attribute + public void getSpeed( + Integer nominator, + Integer denominator) + throws MhegException; + +// Correspond to the SetCounterPosition MHEG-5 elementary action + public void setCounterPosition( + short counterPosition) + throws MhegException; + +// Retrieve the value of the CounterPosition attribute + public Integer getCounterPosition() + throws MhegException; + +// Correspond to the SetCounterEndPosition MHEG-5 elementary action + public void setCounterEndPosition( + short counterEndPosition) + throws MhegException; + +// Retrieve the value of the CounterEndPosition attribute + public Integer getCounterEndPosition() + throws MhegException; + +} + +// ----- +public class □□□□□ extends Presentable +{ + /* Constructors */ + protected Audio(); + + /* Methods */ + +// Correspond to the SetVolume MHEG-5 elementary action + public void setVolume( + byte volume) + throws MhegException; + +// Correspond to the GetVolume MHEG-5 elementary action + public Integer getVolume() + throws MhegException; + +} + +// ----- +public class □□□□□ extends Visible +{ + /* Constructors */ + protected Video(); + + /* Methods */ + +// Correspond to the ScaleVideo MHEG-5 elementary action +// The xScale and yScale parameter values shall be positive and different from +// zero + public void scaleVideo( + short xScale, + short yScale) + throws MhegException; + +} + +// ----- +public class □□□□□□□□□□ extends Visible +{ + /* Constructors */ + protected RTGraphics(); + +} + +``` + +``` + +// ----- +public interface □□□□□□□□□□ +{ + /* Methods */ + // Correspond to the SetInteractionStatus MHEG-5 elementary action + public void setInteractionStatus( + boolean interactionStatus) + throws MhegException; + // Correspond to the GetInteractionStatus MHEG-5 elementary action + public Boolean getInteractionStatus() + throws MhegException; + // Correspond to the SetHighlightStatus MHEG-5 elementary action + public void setHighlightStatus( + boolean highlightStatus) + throws MhegException; + // Correspond to the GetHighlightStatus MHEG-5 elementary action + public Boolean getHighlightStatus() + throws MhegException; +} +// ----- +public class □□□□□□ extends Visible implements Interactable +{ + /* Constructors */ + protected Slider(); + /* Methods */ + // Correspond to the implementation of the Interactable.setInteractionStatus + // method + public void setInteractionStatus( + boolean interactionStatus) + throws MhegException; + // Correspond to the implementation of the Interactable.getInteractionStatus + // method + public Boolean getInteractionStatus() + throws MhegException; + // Correspond to the implementation of the Interactable.setHighlightStatus method + public void setHighlightStatus( + boolean highlightStatus) + throws MhegException; + // Correspond to the implementation of the Interactable.getHighlightStatus method + public Boolean getHighlightStatus() + throws MhegException; + // Correspond to the Step MHEG-5 elementary action + public void step( + byte nbOfSteps) + throws MhegException; + // Correspond to the SetSliderValue MHEG-5 elementary action + public void setSliderValue( + byte sliderValue) + throws MhegException; + // Correspond to the GetSliderValue MHEG-5 elementary action + public Integer getSliderValue() + throws MhegException; + // Correspond to the SetPortion MHEG-5 elementary action + public void setPortion( + byte portion) + throws MhegException; +} + +``` + +``` + +// Correspond to the GetPortion MHEG-5 elementary action + public Integer getPortion() + throws MhegException; +} +// ----- +public class □□□□□□□□ extends Text implements Interactable +{ +/* Constructors */ + protected EntryField(); +/* Methods */ +// Correspond to the implementation of the Interactable.setInteractionStatus +// method + public void setInteractionStatus( + boolean interactionStatus) + throws MhegException; +// Correspond to the implementation of the Interactable.getInteractionStatus +// method + public Boolean getInteractionStatus() + throws MhegException; +// Correspond to the implementation of the Interactable.setHighlightStatus method + public void setHighlightStatus( + boolean highlightStatus) + throws MhegException; +// Correspond to the implementation of the Interactable.getHighlightStatus method + public Boolean getHighlightStatus() + throws MhegException; +// Correspond to the SetOverwriteMode MHEG-5 elementary action + public void setOverwriteMode( + boolean overwriteMode) + throws MhegException; +// Correspond to the GetOverwriteMode MHEG-5 elementary action + public Boolean getOverwriteMode() + throws MhegException; +// Correspond to the SetEntryPoint MHEG-5 elementary action +// The entryPoint parameter value shall be positive or equal to zero + public void setEntryPoint( + byte entryPoint) + throws MhegException; +// Correspond to the GetEntryPoint MHEG-5 elementary action + public Integer getEntryPoint() + throws MhegException; +} +// ----- +public class □□□□□□□□ extends Text implements Interactable +{ +/* Constructors */ + protected HyperText(); +/* Methods */ +// Correspond to the implementation of the Interactable.setInteractionStatus +method + public void setInteractionStatus( + boolean interactionStatus) + throws MhegException; +// Correspond to the implementation of the Interactable.getInteractionStatus +// method + public Boolean getInteractionStatus() + throws MhegException; + +``` + +``` + +// Correspond to the implementation of the Interactable.setHighlightStatus method + public void setHighlightStatus( + boolean highlightStatus) + throws MhegException; + +// Correspond to the implementation of the Interactable.getHighlightStatus method + public Boolean getHighlightStatus() + throws MhegException; + +// Correspond to the GetLastAnchorFired MHEG-5 elementary action + public byte[] getLastAnchorFired() + throws MhegException; +} + +// ----- +abstract public class □□□□□□ extends Visible implements Interactable +{ + /* Constructors */ + protected Button(); + + /* Methods */ +// Correspond to the implementation of the Interactable.setInteractionStatus +// method + public void setInteractionStatus( + boolean interactionStatus) + throws MhegException; + +// Correspond to the implementation of the Interactable.getInteractionStatus +// method + public Boolean getInteractionStatus() + throws MhegException; + +// Correspond to the implementation of the Interactable.setHighlightStatus method + public void setHighlightStatus( + boolean highlightStatus) + throws MhegException; + +// Correspond to the implementation of the Interactable.getHighlightStatus method + public Boolean getHighlightStatus() + throws MhegException; + +// Correspond to the Select MHEG-5 elementary action + public void select() + throws MhegException; + +// Correspond to the Deselect MHEG-5 elementary action + public void deselect() + throws MhegException; +} + +// ----- +public class □□□□□□□□ extends Button +{ + /* Constructors */ + protected Hotspot(); +} + +// ----- +public class □□□□□□□□□□ extends Button +{ + /* Constructors */ + protected PushButton(); + + /* Methods */ +// Correspond to the SetLabel MHEG-5 elementary action + public void setLabel( + byte[] label) + throws MhegException; +} + +``` + +``` + +// Correspond to the GetLabel MHEG-5 elementary action + public byte[] getLabel() + throws MhegException; +} +// ----- +public class □□□□□□□□□□ extends PushButton +{ + +/* Constructors */ + protected SwitchButton(); + +/* Methods */ +// Correspond to the GetSelectionStatus MHEG-5 elementary action + public Boolean getSelectionStatus() + throws MhegException; + +// Correspond to the Toggle MHEG-5 elementary action + public void toggle() + throws MhegException; + +} + +``` + +# 6 Map between MHEG-5 elementary actions and MHEG-5 API operations + +The following Table 1 describes how the MHEG-5 API maps MHEG-5 classes to Java classes and interfaces, and MHEG-5 elementary actions to Java methods. Table 1 is not normative. + +**Table 1/T.175 – Map between MHEG-5 elementary actions and MHEG-5 API operations** + +| MHEG-5 class | MHEG-5 elementary action | API operation (overloads) | API interface or class | +|--------------|--------------------------|---------------------------|------------------------| +| Root | | getObject | Root (abstract class) | +| | GetAvailabilityStatus | getAvailabilityStatus | | +| | GetRunningStatus | getRunningStatus | | +| Group | SetCachePriority | setCachePriority | Group (abstract class) | +| | | getCachePriority | | +| Application | StorePersistent | | Application (class) | +| | ReadPersistent | | | +| | Launch | | | +| | Spawn | | | +| | Quit | | | +| | LockScreen | lockScreen | | +| | UnlockScreen | unlockScreen | | +| | | getLockCount | | +| | OpenConnection | | | +| | CloseConnection | | | +| | GetEngineSupport | getEngineSupport | | + +**Table 1/T.175 – Map between MHEG-5 elementary actions +and MHEG-5 API operations (continued)** + +| MHEG-5 class | MHEG-5 elementary action | API operation (overloads) | API interface or class | +|---------------------|---------------------------------|----------------------------------|-------------------------------| +| Scene | TransitionTo | transitionTo (4) | Scene (class) | +| | SetTimer | setTimer (3) | | +| | | getTimer | | +| | SendEvent | sendEvent (4) | | +| | SetCursorShape | setCursorShape (2) | | +| | | getCursorShape | | +| | SetCursorPosition | setCursorPosition | | +| | GetCursorPosition | getCursorPosition | | +| Ingredient | SetData | setData (5) | Ingredient (abstract class) | +| | | getData | | +| | Clone | clone | | +| | Preload | preload | | +| | Unload | unload | | +| Link | Activate | activate | Link (class) | +| | Deactivate | deactivate | | +| Program | Call | call | Program (abstract class) | +| | Fork | fork | | +| | Stop | stop | | +| ResidentProgram | | | ResidentProgram (class) | +| RemoteProgram | | | RemoteProgram (class) | +| InterchangedProgram | | | InterchangedProgram (class) | +| Palette | | | Palette (class) | +| Font | | | Font (class) | +| CursorShape | | | CursorShape (class) | +| Variable | SetVariable | | Variable (abstract class) | +| | TestVariable | | | +| BooleanVariable | | setVariable | BooleanVariable (class) | +| | | getVariable | | + +**Table 1/T.175 – Map between MHEG-5 elementary actions +and MHEG-5 API operations (continued)** + +| MHEG-5 class | MHEG-5 elementary action | API operation (overloads) | API interface or class | +|---------------------|---------------------------------|----------------------------------|-------------------------------| +| IntegerVariable | | setVariable | IntegerVariable (class) | +| | | getVariable | | +| | Add | add | | +| | Subtract | subtract | | +| | Multiply | multiply | | +| | Divide | divide | | +| | Modulo | modulo | | +| OctetStringVariable | | setVariable | OctetStringVariable (class) | +| | | getVariable | | +| | Append | append | | +| ObjectRefVariable | | setVariable | ObjectRefVariable (class) | +| | | getVariable | | +| ContentRefVariable | | setVariable | ContentRefVariable (class) | +| | | getVariable | | +| Presentable | Run | run | Presentable (abstract class) | +| | Stop | stop | | +| TokenManager | Move | move | TokenManager (interface) | +| | MoveTo | moveTo | | +| | GetTokenPosition | getTokenPosition | | +| TokenGroup | CallActionSlot | callActionSlot | TokenGroup (class) | +| ListGroup | AddItem | addItem | TemplateGroup (class) | +| | DelItem | delItem | | +| | GetListItem | getListItem | | +| | GetCellItem | getCellItem | | +| | GetItemStatus | getItemStatus | | +| | SelectItem | selectItem | | +| | DeselectItem | deselectItem | | +| | ToggleItem | toggleItem | | +| | ScrollItems | scrollItems | | +| | SetFirstItem | setFirstItem | | +| | GetFirstItem | getFirstItem | | +| | GetListSize | getListSize | | + +**Table 1/T.175 – Map between MHEG-5 elementary actions +and MHEG-5 API operations (continued)** + +| MHEG-5 class | MHEG-5 elementary action | API operation (overloads) | API interface or class | +|---------------------|---------------------------------|----------------------------------|-------------------------------| +| Visible | SetPosition | setPosition | Visible (abstract class) | +| | GetPosition | getPosition | | +| | SetBoxSize | setBoxSize | | +| | GetBoxSize | getBoxSize | | +| | BringToFront | bringToFront | | +| | SendToBack | sendToBack | | +| | PutBefore | putBefore | | +| | PutBehind | putBehind | | +| | SetPaletteRef | setPaletteRef | | +| | | getPaletteRef | | +| | | | | +| Bitmap | ScaleBitmap | scaleBitmap | Bitmap (class) | +| | SetTransparency | setTransparency | | +| | | getTransparency | | +| LineArt | SetLineWidth | setLineWidth | LineArt (class) | +| | SetLineStyle | setLineStyle | | +| | SetLineColour | setLineColour (2) | | +| | SetFillColour | setFillColour (3) | | +| Rectangle | | | Rectangle (class) | +| DynamicLineArt | GetLineWidth | getLineWidth | DynamicLineArt (class) | +| | GetLineStyle | getLineStyle | | +| | GetLineColour | getLineColour | | +| | GetFillColour | getFillColour | | +| | DrawArc | drawArc | | +| | DrawSector | drawSector | | +| | DrawLine | drawLine | | +| | DrawOval | drawOval | | +| | DrawPolygon | drawPolygon | | +| | DrawPolyline | drawPolyline | | +| | DrawRectangle | drawRectangle | | +| | Clear | clear | | +| | | | | +| | | | | +| Text | GetTextContent | getTextContent | Text (class) | +| | GetTextData | getTextData | | +| | SetFontRef | setFontRef (2) | | +| | | getFontRef | | + +**Table 1/T.175 – Map between MHEG-5 elementary actions +and MHEG-5 API operations (concluded)** + +| MHEG-5 class | MHEG-5 elementary action | API operation (overloads) | API interface or class | +|---------------------|---------------------------------|----------------------------------|-------------------------------| +| Stream | SetCounterTrigger | setCounterTrigger (2) | Stream (class) | +| | | getCounterTrigger | | +| | SetSpeed | setSpeed (2) | | +| | | getSpeed | | +| | SetCounterPosition | setCounterPosition | | +| | | getCounterPosition | | +| | SetCounterEndPosition | setCounterEndPosition | | +| | | getCounterEndPosition | | +| Audio | SetVolume | setVolume | Audio (class) | +| | GetVolume | getVolume | | +| Video | ScaleVideo | scaleVideo | Video (class) | +| RTGraphics | | | RTGraphics (class) | +| Interactable | SetInteractionStatus | setInteractionStatus | Interactable (interface) | +| | GetInteractionStatus | getInteractionStatus | | +| | SetHighlightStatus | setHighlightStatus | | +| | GetHighlightStatus | getHighlightStatus | | +| Slider | Step | step | Slider (class) | +| | SetSliderValue | setSliderValue | | +| | GetSliderValue | getSliderValue | | +| | SetPortion | setPortion | | +| | GetPortion | getPortion | | +| EntryField | SetOverwriteMode | setOverwriteMode | EntryField (class) | +| | GetOverwriteMode | getOverwriteMode | | +| | SetEntryPoint | setEntryPoint | | +| | GetEntryPoint | getEntryPoint | | +| HyperText | GetLastAnchorFired | getLastAnchorFired | HyperText (class) | +| Button | Select | select | Button (abstract class) | +| | Deselect | deselect | | +| Hotspot | | | Hotspot (class) | +| PushButton | SetLabel | setLabel | PushButton (class) | +| | GetLabel | getLabel | | +| SwitchButton | GetSelectionStatus | getSelectionStatus | SwitchButton (class) | +| | Toggle | toggle | | + +# ITU-T RECOMMENDATIONS SERIES + +| | | +|-----------------|--------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of the ITU-T | +| Series B | Means of expression: definitions, symbols, classification | +| Series C | General telecommunication statistics | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks and open system communications | +| Series Y | Global information infrastructure | +| Series Z | Programming languages | \ No newline at end of file diff --git a/marked/T/T-REC-T.176-199802-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg b/marked/T/T-REC-T.176-199802-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..945fff047a652fbc5286e14bf1dd2055aced6108 --- /dev/null +++ b/marked/T/T-REC-T.176-199802-I_PDF-E/2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:ea94c2ba217ade479d75823c1267da6d043593e8d33e6d635c77710ac9be692f +size 8276 diff --git a/marked/T/T-REC-T.176-199802-I_PDF-E/c803f6f6e2c49429d2951832bd0f208d_img.jpg b/marked/T/T-REC-T.176-199802-I_PDF-E/c803f6f6e2c49429d2951832bd0f208d_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..b0593433e69d104a4d994c42bc1b40e7f5cb47e8 --- /dev/null +++ b/marked/T/T-REC-T.176-199802-I_PDF-E/c803f6f6e2c49429d2951832bd0f208d_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:01c0db2ac35d7af2e5b75a2cac815e8de32bcf644996898efe276f76cb6072fc +size 10208 diff --git a/marked/T/T-REC-T.176-199802-I_PDF-E/raw.md b/marked/T/T-REC-T.176-199802-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..4080ae83bff4d9196bcb51a3cd330ee7d0fdb6ec --- /dev/null +++ b/marked/T/T-REC-T.176-199802-I_PDF-E/raw.md @@ -0,0 +1,702 @@ + + +![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# T.176 + +(02/98) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES + +--- + +# **Application Programming Interface (API) for Digital Storage Media Command and Control (DSM-CC)** + +ITU-T Recommendation T.176 + +(Previously CCITT Recommendation) + +--- + +# ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES** + +![A large empty rectangular box with a double border.](c803f6f6e2c49429d2951832bd0f208d_img.jpg) + +A large empty rectangular box with a double border. + +*For further details, please refer to ITU-T List of Recommendations.* + +## **ITU-T RECOMMENDATION T.176** + +# **APPLICATION PROGRAMMING INTERFACE (API) FOR DIGITAL STORAGE MEDIA COMMAND AND CONTROL (DSM-CC)** + +## **Summary** + +This Recommendation specifies the Application Programming Interface (API) of DSM-CC for the use in basic multimedia applications. + +## **Source** + +ITU-T Recommendation T.176 was prepared by ITU-T Study Group 16 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 6th of February 1998. + +## FOREWORD + +ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +## INTELLECTUAL PROPERTY RIGHTS + +The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, the ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. + +© ITU 1998 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +# CONTENTS + +| | Page | +|-----------------------------------------------------------------|-------------| +| 1 Scope..... | 1 | +| 2 Normative references ..... | 1 | +| 3 Definitions and abbreviations ..... | 1 | +| 3.1 Definitions ..... | 1 | +| 3.2 Abbreviations..... | 2 | +| 4 Overview..... | 2 | +| 4.1 The DAVIC application interchange format..... | 2 | +| 4.2 Core set of Java APIs..... | 2 | +| 5 Package davic.CosNaming ..... | 3 | +| 5.1 Class davic.CosNaming.NameComponent ..... | 3 | +| 5.2 Class davic.CosNaming.Binding ..... | 4 | +| 5.3 Exception davic.CosNaming.NotFound ..... | 4 | +| 5.4 Exception davic.CosNaming.CannotProceed ..... | 4 | +| 5.5 Exception davic.CosNaming.InvalidName ..... | 4 | +| 5.6 Class davic.CosNaming.BindingIterator ..... | 4 | +| 5.7 Interface davic.CosNaming.NamingContext ..... | 5 | +| 6 Package davic.dsmccuu ..... | 5 | +| 6.1 Class davic.dsmccuu.Step ..... | 5 | +| 6.2 Exception davic.dsmccuu.SERVICE_XFR ..... | 5 | +| 6.3 Exception davic.dsmccuu.dsmccuuException ..... | 6 | +| 6.4 Exception davic.dsmccuu.INV_OFFSET ..... | 6 | +| 6.5 Exception davic.dsmccuu.INV_SIZE ..... | 6 | +| 6.6 Exception davic.dsmccuu.READ_LOCKED ..... | 6 | +| 6.7 Exception davic.dsmccuu.WRITE_LOCKED ..... | 6 | +| 6.8 Exception davic.dsmccuu.OPEN_LIMIT ..... | 6 | +| 6.9 Exception davic.dsmccuu.NO_AUTH ..... | 6 | +| 6.10 Exception davic.dsmccuu.UNK_USER ..... | 6 | +| 6.11 Exception davic.dsmccuu.BAD_COMPAT_INFO ..... | 7 | +| 6.12 Exception davic.dsmccuu.NO_RESUME ..... | 7 | +| 6.13 Exception davic.dsmccuu.NO_SUSPEND ..... | 7 | +| 6.14 Interface davic.dsmccuu.Base ..... | 7 | +| 6.15 Class davic.dsmccuu.File ..... | 7 | +| 6.16 Class davic.dsmccuu.Directory ..... | 8 | + +| | Page | +|------------------------------------------------------------|-------------| +| 6.17 Interface davic.dsmccuu.SessionI ..... | 9 | +| 6.18 Class davic.dsmccuu.Session ..... | 9 | +| 6.19 Class davic.dsmccuu.SessionGateway ..... | 10 | + +# Recommendation T.176 + +# APPLICATION PROGRAMMING INTERFACE (API) FOR DIGITAL STORAGE MEDIA COMMAND AND CONTROL (DSM-CC) + +(Geneva, 1998) + +# 1 Scope + +This Recommendation specifies the Application Programming Interface (API) of DSM-CC for the use in basic multimedia applications. This Recommendation is applicable to DAVIC compliant systems. + +# 2 Normative references + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. + +- [1] ETS 300 777-3, *Terminal Equipment (TE); End-to-end protocols for multimedia information retrieval services; Part 3: Application Programmable Interface (API) for MHEG-5*. +- [2] ISO/IEC DIS 13818-6, *Information technology – Generic coding of moving pictures and associated audio information – Part 6: Extension for digital storage media command and control*. +- [3] ISO/IEC 13522-5:1997, *Information technology – Coding of multimedia and hypermedia information – Part 5: Support for base-level interactive applications*. +- [4] ISO/IEC DIS 13522-6, *Information technology – Coding of multimedia and hypermedia information – Part 6: Support for enhanced interactive applications*. +- [5] ETS 300 777-1, *Terminal Equipment (TE); End-to-end protocols for multimedia information retrieval services; Part 1: Coding of multimedia and hypermedia information for basic multimedia applications (MHEG-5)*. + +# 3 Definitions and abbreviations + +## 3.1 Definitions + +For the purposes of this Recommendation the definition of ISO/IEC DIS 13818-6 [2] apply. + +This Recommendation defines the following terms: + +**3.1.1 application programmable interface (API):** A boundary across which a software application uses facilities of programming languages to invoke software services. These facilities may include procedures or operations, shared data objects and resolution of identifiers. + +**3.1.2 local application:** A piece of software which is part of the (telecommunication) application and is running on the considered equipment. + +## 3.2 Abbreviations + +This Recommendation uses the following abbreviations + +| | | +|--------|------------------------------------------------------------| +| API | Application Programming Interface | +| ASN.1 | Abstract Syntax Notation One | +| DAVIC | Digital Audio Visual Council | +| DSM-CC | Digital Storage Media Command and Control | +| MHEG | Multimedia and Hypermedia information coding Experts Group | +| SI | Service Information | +| STU | Set Top Unit | +| VM | Virtual Machine | + +# 4 Overview + +The following clause positions the API defined by this Recommendation in the framework of the DAVIC specifications. + +## 4.1 The DAVIC application interchange format + +To deliver multimedia information to STUs in an interoperable way, applications shall use the MHEG-5 final form interchange format, as defined by ISO/IEC 13522-5 [3]. The ASN.1 notation and encoding, as defined by ETS 300 777-1 [4], shall be used to interchange MHEG-5 objects. This format defines the semantics and the encoding of the multimedia and hypermedia objects. + +To deliver program code to STUs in an interoperable way, applications shall use the MHEG-5 `InterchangedProgram` class to encapsulate Java1 VM code, according to the semantics and encoding defined by ISO/IEC DIS 13522-6 [5]. Java VM classes are called from MHEG-5 objects using the MHEG-5 `Call` and `Fork` elementary actions. + +The Java VM code interchange unit is a Java VM class. Java VM classes shall be encoded as defined by the Class File Format section of the Java Virtual machine specification. A Java class encapsulates data and methods that consist of sequences of instructions. The instruction set is defined by the Java Virtual machine instruction set section of the Java Virtual machine specification. + +## 4.2 Core set of Java APIs + +The following set of APIs are used by Java VM code in the DAVIC 1.1 [1] specifications to express access to basic functions of the STU in an interoperable way: + +- the `java.lang` package; +- the `java.util` package; +- the `iso.mheg5` package; +- the `davic.dsmccuu` package; +- the `etsi.si` package. + +--- + +1 Java is a trademark or a registered trademark of Sun Microsystems, Inc. + +NOTE 1 – The Java VM specification provides flexible mechanisms to call upon external functions whose interface is defined as a Java package. The DAVIC 1.1 specification only includes a minimum core set of packages required for Java VM code to be useful in a DAVIC environment. It is anticipated that additional Java packages will be standardised at a later stage. + +NOTE 2 – Especially, the `java.io` package, although strictly speaking not necessary to the useful performance of the VM environment, is part of the Java foundation classes. It is intended that the `java.io` package be added to the DAVIC core set of Java APIs together with an adequate specification of its semantics in a DAVIC environment. + +The `java.lang` package, as defined by the Java API documentation, consists of the minimal set of Java VM classes needed to run Java VM code, supporting the following functionality: basic data types, object, mathematic operations, security, thread management, string manipulation, exception handling. + +The `java.util` package, as defined by the Java API documentation, consists of Java VM classes supporting a number of utility features common to all Java VM programs. + +The `iso.mheg5` package, as defined by ETS 300 777-3 [1], provides Java VM code with access to and manipulation of the MHEG-5 multimedia presentation and interaction objects, i.e. access to the dynamic attributes of MHEG-5 objects and invocation of elementary actions on MHEG-5 objects. + +The `davic.dsmccuu` and the associated `davic.CosNaming` packages enable Java VM code to use the DSM-CC U-U interface objects for network data access. + +The `davic.dsmccuu` and the associated `davic.CosNaming` packages give access to a subset of the DSM-CC U-U API defined by ISO/IEC DIS 13818-6. This subset consists of: + +- the `list` and `resolve` operations of the `NamingContext` abstract interface; +- the `close` and `destroy` operations of the `Base` abstract interface; +- the `next_one` and `next_n` operations of the `BindingIterator` instanciable interface; +- the `open` and `close` operations of the `Directory` instanciable interface; +- the `read` and `write` operations as well as the `ContentSize` read-only attribute of the `File` instanciable interface; +- the `attach` and `detach` operations of the `Session` instanciable interface; +- the `SessionGateway` instanciable interface. + +The `etsi.si` package enables Java VM code to access information transmitted in the DAVIC Service Information (SI) stream. + +# **5 Package `davic.CosNaming`** + +## **5.1 Class `davic.CosNaming.NameComponent`** + +``` +package davic.CosNaming; +``` + +``` +public class NameComponent { + public String id; + public String kind; +} +``` + +## 5.2 Class `davic.CosNaming.Binding` + +``` +package davic.CosNaming; + +public class Binding { + // constant declarations for the "binding_type" attribute + public static final short nobject = 0; + public static final short ncontext = 1; + + public NameComponent[] binding_name; + public int binding_type; +} +``` + +### 5.3 Exception `davic.CosNaming.NotFound` + +``` +package davic.CosNaming; + +public class NotFound extends Exception{ + // constant declarations for the "why" attribute + public static final short missing_node = 0; + public static final short not_context = 1; + public static final short not_object = 2; + + public int why; + public NameComponent[] rest_of_name; +} +``` + +## 5.4 Exception `davic.CosNaming.CannotProceed` + +``` +package davic.CosNaming; + +public class CannotProceed extends Exception{ + public NamingContext ext; + public NameComponent[] rest_of_name; +} +``` + +### 5.5 Exception `davic.CosNaming.InvalidName` + +``` +package davic.CosNaming; + +public class InvalidName extends Exception{ +} +``` + +### 5.6 Class `davic.CosNaming.BindingIterator` + +``` +package davic.CosNaming; + +public class BindingIterator { + public boolean next_one( + Binding b + ) + { + // actual code shall be inserted here + return true; + } +} +``` + +``` + + public void next_n( + int how_many, + Binding[] bl + ) + { + // actual code shall be inserted here + } + + public void destroy() + { + // actual code shall be inserted here + } +} + +``` + +## 5.7 Interface `davic.CosNaming.NamingContext` + +``` +package davic.CosNaming; +``` + +``` + +public interface NamingContext { + public void list( + int how_many, + Binding[] bl, + BindingIterator bi + ); + + public Object resolve( + NameComponent[] n + )throws NotFound, CannotProceed, InvalidName; +} + +``` + +# 6 Package `davic.dsmccuu` + +## 6.1 Class `davic.dsmccuu.Step` + +``` + +package davic.dsmccuu; + +import davic.CosNaming.*; + +public class Step { + public NameComponent name; + public boolean process; +} + +``` + +## 6.2 Exception `davic.dsmccuu.SERVICE_XFR` + +``` + +package davic.dsmccuu; + +import davic.CosNaming.*; + +public class SERVICE_XFR extends Exception { + // service location + public byte[] serviceDomain; + public NameComponent[] pathName; + public byte[] initialContext; +} + +``` + +## **6.3 Exception `davic.dsmccuu.dsmccuuException`** + +``` +package davic.dsmccuu; + +public class dsmccuuException extends Exception { + public short minor; + public short completed; +} +``` + +## **6.4 Exception `davic.dsmccuu.INV_OFFSET`** + +``` +package davic.dsmccuu; + +public class INV_OFFSET extends dsmccuuException { +} +``` + +## **6.5 Exception `davic.dsmccuu.INV_SIZE`** + +``` +package davic.dsmccuu; + +public class INV_SIZE extends dsmccuuException { +} +``` + +## **6.6 Exception `davic.dsmccuu.READ_LOCKED`** + +``` +package davic.dsmccuu; + +public class READ_LOCKED extends dsmccuuException { +} +``` + +## **6.7 Exception `davic.dsmccuu.WRITE_LOCKED`** + +``` +package davic.dsmccuu; + +public class WRITE_LOCKED extends dsmccuuException { +} +``` + +## **6.8 Exception `davic.dsmccuu.OPEN_LIMIT`** + +``` +package davic.dsmccuu; + +public class OPEN_LIMIT extends dsmccuuException { +} +``` + +## **6.9 Exception `davic.dsmccuu.NO_AUTH`** + +``` +package davic.dsmccuu; + +public class NO_AUTH extends dsmccuuException { + public byte[] authData; +} +``` + +## **6.10 Exception `davic.dsmccuu.UNK_USER`** + +``` +package davic.dsmccuu; + +public class UNK_USER extends dsmccuuException { +} +``` + +## 6.11 Exception **davic.dsmccuu.BAD\_COMPAT\_INFO** + +``` +package davic.dsmccuu; + +public class BAD_COMPAT_INFO extends dsmccuuException { +} +``` + +## 6.12 Exception **davic.dsmccuu.NO\_RESUME** + +``` +package davic.dsmccuu; + +public class NO_RESUME extends dsmccuuException { +} +``` + +## 6.13 Exception **davic.dsmccuu.NO\_SUSPEND** + +``` +package davic.dsmccuu; + +public class NO_SUSPEND extends dsmccuuException { +} +``` + +## 6.14 Interface **davic.dsmccuu.Base** + +``` +package davic.dsmccuu; + +interface Base { + public void close(); + + public void destroy(); +} +``` + +## 6.15 Class **davic.dsmccuu.File** + +``` +package davic.dsmccuu; + +public class File implements Base { + // Base.close implementation + public void close() + { + // actual code shall be inserted here + } + + // Base.destroy implementation + public void destroy() + { + // actual code shall be inserted here + } + + public int[] getContentSize() + { + // actual code shall be inserted here + return null; + } + + public void read( + int[] aOffset, + int aSize, + boolean aReliable, + byte[] rData +``` + +``` + + ) throws + INV_OFFSET, INV_SIZE, READ_LOCKED + { + // actual code shall be inserted here + } + + public void write( + int[] aOffset, + int aSize, + byte[] rData + ) throws + INV_OFFSET, INV_SIZE, WRITE_LOCKED + { + // actual code shall be inserted here + } +} + +``` + +## 6.16 Class `davic.dsmccuu.Directory` + +``` + +package davic.dsmccuu; + +import davic.CosNaming.*; + +public class Directory implements NamingContext { + // NamingContext.list implementation + public void list( + int how_many, + Binding[] bl, + BindingIterator bi + ) + { + // actual code shall be inserted here + } + + // NamingContext.resolve implementation + public Object resolve( + NameComponent[] n + ) throws NotFound, CannotProceed, InvalidName + { + // actual code shall be inserted here + return null; + } + + public void open( + char aPathType, + Step[] rPathStep, + Object[] resolvedRefs + ) throws + OPEN_LIMIT, NO_AUTH, UNK_USER, SERVICE_XFR, + NotFound, CannotProceed, InvalidName + { + // actual code shall be inserted here + } + + public void close() + { + // actual code shall be inserted here + } +} + +``` + +## 6.17 Interface `davic.dsmccuu.SessionI` + +``` +package davic.dsmccuu; + +import davic.CosNaming.*; + +interface SessionI { + public void attach( + byte[] serviceDomain, + NameComponent[] pathName, + byte[] userContext, + Object[] resolvedRefs + ) throws + OPEN_LIMIT, NO_AUTH, UNK_USER, SERVICE_XFR, BAD_COMPAT_INFO, NO_RESUME, + NotFound, CannotProceed, InvalidName; + + public void detach( + boolean aSuspend, + byte[] savedContext + ) throws + NO_SUSPEND; +} +``` + +## 6.18 Class `davic.dsmccuu.Session` + +``` +package davic.dsmccuu; + +public class Session implements SessionI { + // SessionI.attach implementation + public void attach( + byte[] serviceDomain, + NameComponent[] pathName, + byte[] userContext, + Object[] resolvedRefs + ) throws + OPEN_LIMIT, NO_AUTH, UNK_USER, SERVICE_XFR, BAD_COMPAT_INFO, NO_RESUME, + NotFound, CannotProceed, InvalidName + { + // actual code shall be inserted here + } + + // SessionI.detach implementation + public void detach( + boolean aSuspend, + byte[] savedContext + ) throws + NO_SUSPEND + { + // actual code shall be inserted here + } +} +``` + +## 6.19 Class `davic.dsmccuu.SessionGateway` + +``` +package davic.dsmccuu; +``` + +``` +public class SessionGateway extends Directory implements SessionI { + // SessionI.attach implementation + public void attach( + byte[] serviceDomain, + NameComponent[] pathName, + byte[] userContext, + Object[] resolvedRefs + ) throws + OPEN_LIMIT, NO_AUTH, UNK_USER, SERVICE_XFR, BAD_COMPAT_INFO, NO_RESUME, + NotFound, CannotProceed, InvalidName + { + // actual code shall be inserted here + } + + // SessionI.detach implementation + public void detach( + boolean aSuspend, + byte[] savedContext + ) throws + NO_SUSPEND + { + // actual code shall be inserted here + } +} +``` + +# ITU-T RECOMMENDATIONS SERIES + +| | | +|-----------------|--------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of the ITU-T | +| Series B | Means of expression: definitions, symbols, classification | +| Series C | General telecommunication statistics | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | TMN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks and open system communications | +| Series Y | Global information infrastructure | +| Series Z | Programming languages | \ No newline at end of file diff --git a/marked/T/T-REC-T.190-199508-I_PDF-E/raw.md b/marked/T/T-REC-T.190-199508-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..2be99ec127e8c266d752f17f1d30d1be67f224e0 --- /dev/null +++ b/marked/T/T-REC-T.190-199508-I_PDF-E/raw.md @@ -0,0 +1,2912 @@ + + +![ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe. + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**T.190** + +(08/95) + +**TERMINALS FOR TELEMATIC SERVICES** + +--- + +**COOPERATIVE DOCUMENT +HANDLING (CDH) – +FRAMEWORK AND BASIC SERVICES** + +**ITU-T Recommendation T.190** + +(Previously "CCITT Recommendation") + +--- + +# FOREWORD + +The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). + +ITU-T Recommendation T.190 was prepared by ITU-T Study Group 8 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 11th of August 1995. + +# --- NOTE + +In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +© ITU 1996 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +# CONTENTS + +| | Page | +|-----------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 2.1 Identical Recommendations International Standards ..... | 1 | +| 2.2 Additional references ..... | 2 | +| 3 Definitions ..... | 3 | +| 4 Abbreviations..... | 4 | +| 5 Introduction to document communication basic services..... | 6 | +| 5.1 Basic services that can be stand-alone services ..... | 6 | +| 5.1.1 Storing basic service..... | 6 | +| 5.1.2 Distribution basic service ..... | 7 | +| 5.1.3 Retrieval basic service ..... | 7 | +| 5.1.4 Storing-and-retrieval basic service ..... | 7 | +| 5.1.5 Manipulation basic service ..... | 7 | +| 5.2 Basic services that cannot be stand-alone services ..... | 8 | +| 5.2.1 Pointing basic service ..... | 8 | +| 5.2.2 Multi-pointing basic service ..... | 8 | +| 5.2.3 Token-interchange basic service..... | 8 | +| 5.3 Classification of basic services..... | 8 | +| 6 Introduction to document communication complex services ..... | 9 | +| 6.1 Asynchronous document production ..... | 10 | +| 6.1.1 Description ..... | 10 | +| 6.1.2 Service construction rules..... | 10 | +| 6.1.3 Example of concrete applications ..... | 11 | +| 6.2 Sequential document production ..... | 11 | +| 6.2.1 Description ..... | 11 | +| 6.2.2 Service construction rules..... | 11 | +| 6.2.3 Examples of concrete applications ..... | 13 | +| 6.3 Joint synchronous editing and remote presentation ..... | 14 | +| 6.3.1 Using MCS ..... | 14 | +| 6.3.2 Without MCS..... | 17 | +| 6.3.3 Example of concrete applications ..... | 17 | +| 6.4 Joint document presentation/viewing ..... | 18 | +| 6.4.1 Description ..... | 18 | +| 6.4.2 Service construction rules..... | 18 | +| 6.4.3 Example of concrete applications ..... | 20 | +| 7 Document aspects ..... | 20 | +| 7.1 Introduction..... | 20 | +| 7.2 ODA DAPs..... | 20 | +| 7.2.1 DAPs for document processing applications ..... | 21 | +| 7.2.2 DAPs for image applications ..... | 21 | +| 7.3 Use of ODA DAPs ..... | 21 | +| 8 Communication aspects ..... | 21 | +| 8.1 Introduction..... | 22 | +| 8.2 Document Filing and Retrieval (DFR) ..... | 22 | +| 8.2.1 Description ..... | 22 | +| 8.2.2 Services, protocols and profiles..... | 22 | +| 8.2.3 Use for document communication ..... | 23 | + +| | Page | +|------------------------------------------------------------------------------------------------------------|-------------| +| 8.3 Document Transfer And Manipulation – Bulk Transfer – Normal Mode (DTAM-BT-NM)..... | 23 | +| 8.3.1 Description ..... | 23 | +| 8.3.2 Services, protocols and profiles..... | 23 | +| 8.3.3 Use for document communication ..... | 24 | +| 8.4 Document Transfer And Manipulation – Document Manipulation (DTAM-DM)..... | 24 | +| 8.4.1 Description ..... | 24 | +| 8.4.2 Services, protocols and profiles..... | 24 | +| 8.4.3 Use for document communication ..... | 25 | +| 8.5 Document Transfer And Manipulation – ToKen Exchange (DTAM-TK) ..... | 25 | +| 8.5.1 Description ..... | 25 | +| 8.5.2 Services, protocols and profiles..... | 25 | +| 8.5.3 Use for document communication ..... | 25 | +| 8.6 Combined use of DFR and DTAM-DM (DFR/DTAM-DM) ..... | 25 | +| 8.6.1 Description ..... | 25 | +| 8.6.2 Services, protocols and profiles..... | 25 | +| 8.6.3 Use for document communication ..... | 25 | +| 8.7 Message Handling Systems (MHS)..... | 26 | +| 8.7.1 Description ..... | 26 | +| 8.7.2 Services, protocols and profiles..... | 26 | +| 8.7.3 Use for document communication ..... | 26 | +| 8.8 Multipoint Communication Service (MCS)..... | 27 | +| 8.8.1 Description ..... | 27 | +| 8.8.2 Services and profile ..... | 27 | +| 8.8.3 Use for document communication ..... | 27 | +| 9 Components and design rules for basic services ..... | 27 | +| 9.1 Definition of document related service attributes..... | 28 | +| 9.1.1 The service attribute "document location" ..... | 28 | +| 9.1.2 The service attribute "document copies" ..... | 28 | +| 9.1.3 The service attribute "document access rights" ..... | 29 | +| 9.1.4 The service attribute "store access rights" ..... | 29 | +| 9.1.5 The service attribute "document format" ..... | 30 | +| 9.1.6 The service attribute "functionality level" ..... | 30 | +| 9.2 Definition of communication related service attributes..... | 31 | +| 9.2.1 The service attribute "number of communicating entities" ..... | 31 | +| 9.2.2 The service attribute "communication type" ..... | 32 | +| 9.2.3 The service attribute "communication module" ..... | 32 | +| 9.3 Rules for the formal definition of basic services ..... | 32 | +| 9.3.1 Rules and notation for the assignment of values to the document related service attributes..... | 33 | +| 9.3.2 Rules and notation for the assignment of values to the communication related service attributes..... | 34 | +| 9.3.3 Rules and notation for the selection of the communication modules ..... | 34 | +| 9.3.4 Application rules..... | 35 | +| 10 Formal definition of document communication basic services ..... | 35 | +| 10.1 Storing basic service..... | 35 | +| 10.1.1 Document related service attributes..... | 35 | +| 10.1.2 Communication related service attributes..... | 35 | +| 10.1.3 Selection of communication modules ..... | 37 | +| 10.1.4 Application rules..... | 37 | +| 10.2 Distribution basic service ..... | 38 | +| 10.2.1 Document related service attributes..... | 38 | +| 10.2.2 Communication related service attributes..... | 39 | +| 10.2.3 Selection of communication modules ..... | 39 | +| 10.2.4 Application rules..... | 40 | + +| | | | +|--------------------------------------------------------|------------------------------------------------------------------------------------------|----| +| 10.3 | Retrieval basic service..... | 41 | +| 10.3.1 | Document related service attributes..... | 41 | +| 10.3.2 | Communication related service attributes..... | 41 | +| 10.3.3 | Selection of communication modules..... | 42 | +| 10.3.4 | Application rules..... | 42 | +| 10.4 | Storing-and-Retrieval basic service..... | 44 | +| 10.4.1 | Document related service attributes..... | 44 | +| 10.4.2 | Communication related service attributes..... | 44 | +| 10.4.3 | Selection of communication modules..... | 45 | +| 10.4.4 | Application rules..... | 47 | +| 10.5 | Manipulation basic service..... | 48 | +| 10.5.1 | Document related service attributes..... | 48 | +| 10.5.2 | Communication related service attributes..... | 48 | +| 10.5.3 | Relationship to communication modules..... | 48 | +| 10.5.4 | Application rules..... | 50 | +| 10.6 | Pointing basic service..... | 52 | +| 10.6.1 | Document related service attributes..... | 52 | +| 10.6.2 | Communication related service attributes..... | 52 | +| 10.6.3 | Selection of communication modules..... | 53 | +| 10.6.4 | Application rules..... | 53 | +| 10.7 | Multi-pointing basic service..... | 53 | +| 10.7.1 | Document related service attributes..... | 54 | +| 10.7.2 | Communication related service attributes..... | 54 | +| 10.7.3 | Selection of communication modules..... | 54 | +| 10.7.4 | Application rules..... | 54 | +| 10.8 | Token-interchange basic service..... | 56 | +| 10.8.1 | Document related service attributes..... | 56 | +| 10.8.2 | Communication related service attributes..... | 57 | +| 10.8.3 | Selection of communication modules..... | 57 | +| 10.8.4 | Application rules..... | 58 | +| Appendix I – Use of further communication modules..... | | 59 | +| I.1 | Document Transfer And Manipulation – Bulk Transfer – Transparent Mode (DTAM-BT-TM) ..... | 59 | +| I.1.1 | Description ..... | 59 | +| I.1.2 | Services, protocols and profiles..... | 59 | +| I.1.3 | Use for document communication ..... | 59 | +| I.2 | Facsimile group 3 (FAX3)..... | 60 | +| I.2.1 | Description ..... | 60 | +| I.2.2 | Services, protocols and profiles..... | 60 | +| I.2.3 | Use for document communication ..... | 60 | +| I.3 | File Transfer, Access and Manipulation (FTAM)..... | 61 | +| I.3.1 | Description ..... | 61 | +| I.3.2 | Services, protocols and profiles..... | 61 | +| I.3.3 | Use for document communication ..... | 61 | +| I.4 | Facsimile group 4 (FAX4) application..... | 61 | +| I.4.1 | Description ..... | 61 | +| I.4.2 | Services, protocols and profiles..... | 62 | +| I.4.3 | Use for document communication ..... | 62 | +| I.5 | Binary File Transfer (BFT) application..... | 62 | +| I.5.1 | Description ..... | 62 | +| I.5.2 | Services, protocols and profiles..... | 62 | +| I.5.3 | Use for document communication ..... | 62 | + +| | Page | +|-----------------------------------------------------------------------------------------|-------------| +| Appendix II – Implementation guidelines ..... | 63 | +| II.1    General implementation guidelines ..... | 63 | +| II.1.1    Amount of information to be transferred ..... | 63 | +| II.1.2    Mapping of DFR access rights to access rights of this Recommendation..... | 63 | +| II.1.3    Quality of Service (QOS) ..... | 63 | +| II.1.4    Security ..... | 64 | +| II.2    Specific implementation hints for the storing basic service..... | 65 | +| II.3    Specific implementation hints for the distribution basic service ..... | 65 | +| II.4    Specific implementation hints for the retrieval basic service ..... | 66 | +| II.5    Specific implementation hints for the storing-and-retrieval basic service ..... | 66 | +| II.6    Specific implementation hints for the manipulation basic service..... | 66 | +| II.7    Specific implementation hints for the pointing basic service ..... | 67 | +| II.8    Specific implementation hints for the multi-pointing basic service..... | 67 | +| II.9    Specific implementation hints for the token-interchange basic service ..... | 67 | +| Appendix III – Bibliography..... | 67 | +| III.1    Document architectures..... | 67 | +| III.1.1    Open Document Architecture (ODA) extensions ..... | 67 | +| III.1.2    ODA profiles ..... | 68 | +| III.2    Communication architectures..... | 68 | +| III.2.1    Base documents ..... | 68 | +| III.2.2    Document Transfer And Manipulation (DTAM)..... | 69 | +| III.2.3    Facsimile group 3 (FAX3)..... | 69 | +| III.2.4    File Transfer, Access and Manipulation (FTAM) ..... | 69 | +| III.2.5    Facsimile group 4 (FAX4)..... | 69 | +| III.2.6    Binary File Transfer (BFT)..... | 69 | + +# **SUMMARY** + +This Recommendation specifies ODA document communication services to be provided on top of existing base standards or profiles, giving constraints on them and rules on how to use and combine them. + +This Recommendation specifies basic services, like storing-and-retrieval or manipulation of documents. Complex services, such as asynchronous document production or joint document presentation, are founded on basic services, and are specified in other Recommendations. Some of these complex services are introduced in this Recommendation in order to more clearly understand the complex services that could be built on top of the basic ones. + + + +# COOPERATIVE DOCUMENT HANDLING (CDH) – FRAMEWORK AND BASIC SERVICES + +(Geneva, 1995) + +# 1 Scope + +The Open Document Architecture (ODA) base Recommendations | International Standards and associated profiles specify the means to represent and interchange complex documents. + +Communication base Recommendations | International Standards and associated profiles, specifying interchange, remote manipulation and management of documents at the application layer of the Open Systems Interconnection (OSI) reference model, have also been specified, as Document Transfer And Manipulation (DTAM) and Document Filing and Retrieval (DFR). + +Standardizing document communication services will help implementors and service providers to extend the use and acceptance of these services. Furthermore, the standardization of document communication service profiles will facilitate interworking. + +This Recommendation specifies ODA document communication services to be provided on top of existing base standards or profiles, giving constraints on them and rules on how to use and combine them. + +This Recommendation specifies basic services, like storing-and-retrieval or manipulation. Complex services, such as asynchronous document production or joint document presentation, are founded on basic services, and are specified in other Recommendations. Some of these complex services are introduced in this Recommendation in order to more clearly understand the complex services that could be built on top of the basic ones. + +# 2 References + +The following Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of currently valid ITU-T Recommendations is regularly published. + +## 2.1 Identical Recommendations | International Standards + +- ITU-T Recommendation T.411 (1993) | ISO/IEC 8613-1:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Introduction and general principles.* +- ITU-T Recommendation T.412 (1993) | ISO/IEC 8613-2:1995, *Information technology – Open Document Architecture (ODA) and interchange format: Document structures.* +- ITU-T Recommendation T.413 (1994) | ISO/IEC 8613-3:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Abstract interface for the manipulation of ODA documents.* +- ITU-T Recommendation T.414 (1993) | ISO/IEC 8613-4:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Document profile.* +- ITU-T Recommendation T.415 (1993) | ISO/IEC 8613-5:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Open Document Interchange Format.* +- ITU-T Recommendation T.416 (1993) | ISO/IEC 8613-6:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Character content architectures.* +- ITU-T Recommendation T.417 (1993) | ISO/IEC 8613-7:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Raster graphics content architectures.* + +- ITU-T Recommendation T.418 (1993) | ISO/IEC 8613-8:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Geometric graphics content architectures.* +- ITU-T Recommendation T.422 (1995) | ISO/IEC 8613-12:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Identification of document fragments.* +- ITU-T Recommendation T.122 (1993), *Multipoint communication service for audiographics and audiovisual conferencing service definition.* +- ITU-T Recommendation T.125 (1994), *Multipoint communication service protocol specification.* +- ITU-T Recommendation X.500 (1993) | ISO/IEC 9594-1:1990, *Information technology – Open Systems Interconnection – The Directory – Overview of concepts, models and services.* +- ITU-T Recommendation X.501 (1993) | ISO/IEC 9594-2:1990, *Information technology – Open Systems Interconnection – The Directory – Models.* +- ITU-T Recommendation X.509 (1993) | ISO/IEC 9594-8:1990, *Information technology – Open Systems Interconnection – The Directory – Authentication framework.* +- ITU-T Recommendation X.511 (1993) | ISO/IEC 9594-3:1990, *Information technology – Open Systems Interconnection – The Directory – Abstract service definition.* +- ITU-T Recommendation X.518 (1993) | ISO/IEC 9594-4:1990, *Information technology – Open Systems Interconnection – The Directory – Procedures for distributed operation.* +- ITU-T Recommendation X.519 (1993) | ISO/IEC 9594-5:1990, *Information technology – Open Systems Interconnection – The Directory – Protocol specification.* +- ITU-T Recommendation X.520 (1993) | ISO/IEC 9594-6:1990, *Information technology – Open Systems Interconnection – The Directory – Selected attribute types.* +- ITU-T Recommendation X.521 (1993) | ISO/IEC 9594-7:1990, *Information technology – Open Systems Interconnection – The Directory – Selected object classes.* + +## 2.2 Additional references + +- ITU-T Recommendation T.435 (1995), *Document Transfer And Manipulation (DTAM) – Services and protocols – Abstract service definition and procedures for confirmed document manipulation.* +- ITU-T Recommendation T.436 (1995), *Document Transfer And Manipulation (DTAM) – Services and protocols – Protocol specifications for confirmed document manipulation.* +- CCITT Recommendation T.522 (1992), *Communication application profile BTI for document bulk transfer.* +- ISO/IEC 10021:1990, *Information technology – Text communication – Message-Oriented Text Interchange Systems (MOTIS).* +- ISO/IEC 10166-1:1991, *Information technology – Text and office systems – Document Filing and Retrieval (DFR) – Part 1: Abstract service definition and procedures.* +- ISO/IEC 10166-1:1991/Cor. 1 and Cor. 2:1994, *Information technology – Text and office systems – Document Filing and Retrieval (DFR) – Part 1: Abstract service definition and procedures – Technical corrigendum 1 and Technical corrigendum 2.* +- ISO/IEC 10166-2:1991, *Information technology – Text and office systems – Document Filing and Retrieval (DFR) – Part 2: Protocol specification.* +- ISO/IEC ISP 10610-1:1993, *Information technology – International standardized profile FOD11 – Open document format: Simple document structure – Character content architecture only – Part 1: Document Application Profile (DAP).* +- ISO/IEC ISP 10611-1:1994, *Information technology – International standardized profiles – AMH1n – Message Handling Systems – Common messaging – Part 1: MHS service support.* +- ISO/IEC ISP 10611-2:1994, *Information technology – International standardized profiles – AMH1n – Message Handling Systems – Common messaging – Part 2: Specification of ROSE, RTSE, ACSE, presentation and session protocols for use by MHS.* + +- ISO/IEC ISP 10611-3:1994, *Information technology – International standardized profiles – AMH1n – Message Handling Systems – Common messaging – Part 3: AMH11 – Message transfer (P1)*. +- ISO/IEC ISP 10611-4:1994, *Information technology – International standardized profiles – AMH1n – Message Handling Systems – Common messaging – Part 4: AMH12 – MTS access (P3)*. +- ISO/IEC ISP 10611-5:1994, *Information technology – International standardized profiles – AMH1n – Message Handling Systems – Common messaging – Part 5: AMH13 – MS access (P7)*. +- ISO/IEC ISP 11181-1:1993, *Information technology – International standardized profile FOD26 – Open document format: Enhanced document structure – Character, raster graphics and geometric graphics content architectures – Part 1: Document Application Profile (DAP)*. +- ISO/IEC ISP 11182-1:1993, *Information technology – International standardized profile FOD36 – Open document format: Extended document structure – Character, raster graphics and geometric graphics content architectures – Part 1: Document Application Profile (DAP)*. +- ISO/IEC ISP 12062-1:1995, *Information technology – International standardized profiles – AMH2n – Message Handling Systems – Interpersonal messaging – Part 1: IPM MHS service support*. +- ISO/IEC ISP 12062-2:1995, *Information technology – International standardized profiles – AMH2n – Message Handling Systems – Interpersonal messaging – Part 2: AMH21 – IPM content*. +- ISO/IEC ISP 12062-3:1995, *Information technology – International standardized profiles – AMH2n – Message Handling Systems – Interpersonal messaging – Part 3: AMH22 – IPM requirements for Message Transfer (P1)*. +- ISO/IEC ISP 12062-4:1995, *Information technology – International standardized profiles – AMH2n – Message Handling Systems – Interpersonal messaging – Part 4: AMH23 – IPM requirements for MTS Access (P3)*. +- ISO/IEC ISP 12062-5:1995, *Information technology – International standardized profiles – AMH2n – Message Handling Systems – Interpersonal messaging – Part 5: AMH24 – IPM requirements for Enhanced MS Access (P7)*. +- ISO/IEC ISP 12069, *Information technology – International standardized profiles – Application profiles for Document Filing and Retrieval (DFR)*. +- ISO/IEC ISP, *Information technology – International standardized profiles AODnn – Application profiles for Open Document Architecture (ODA): Profiles for interactive manipulation of ODA documents*. + +# 3 Definitions + +For the purposes of this Recommendation, all the definitions, if any, given in the Recommendations | International Standards listed in References apply. + +For the purposes of this Recommendation, the following definitions apply. + +**3.1 basic service:** A fundamental service which can be a stand-alone service or part of more complex services. + +**3.2 client:** A communicating entity requesting services provided by a server. + +**3.3 communication application:** The whole of means and procedures to enable remote access, management and manipulation of information by a communicating entity, and to perform the transfer of information and operations between communicating entities. These may include remote access, management and manipulation of document stores, documents inside document stores and document fragments inside documents. A communication application uses communication modules to transfer information and operations. + +**3.4 communicating entity:** An entity which performs a communication application with the goal to communicate information and operations to or from a remote communicating entity, using a communication link. A communicating entity may be a human, hardware or software. + +**3.5 communication link:** A connection between two communicating entities. + +- 3.6 communication module:** A standardized set of operations and protocols that belong to the application layer. +- 3.7 complex service:** A service which can be founded on basic services, providing an enhanced task of a document communication application. +- 3.8 document:** An ODA document. +- 3.9 document fragment:** An ODA document fragment. +- 3.10 document store:** A storage capacity with well-defined structure intended to contain documents. +- 3.11 full document:** A complete document which does not constitute a part of another document. +- 3.12 server:** A communicating entity which provides services for other communicating entities. A server may possess and administer a document store. +- 3.13 service:** A well-defined task of a document communication application. +- 3.14 set of document fragments:** One or more document fragments. +- 3.15 set of full documents:** One or more full documents. +- 3.16 user:** A human communicating entity. + +# 4 Abbreviations + +For the purposes of this Recommendation, the following abbreviations are used: + +| | | +|------------|-----------------------------------------------------------------------| +| ACSE | Association Control Service Element | +| ADF | Application profile for DFR | +| AFT | Application profile for FT | +| AMH | Application profile for MHS | +| AOD | Application profile for ODA | +| ASE | Application Service Element | +| ATS | Abstract Test Suite | +| BFT | Binary File Transfer | +| BS | Basic Service | +| BT | Bulk Transfer | +| CAP | Communication Application Profile | +| CCITT | International Telephone and Telegraph Consultative Committee | +| DAP | Document Application Profile | +| DFR | Document Filing and Retrieval | +| DM | Document Manipulation | +| DOAM | Distributed Office Applications Model | +| DST | DiSTribution basic service | +| DTAM | Document Transfer And Manipulation | +| DTAM-BT-NM | Document Transfer And Manipulation – Bulk Transfer – Normal Mode | +| DTAM-BT-TM | Document Transfer And Manipulation – Bulk Transfer – Transparent Mode | +| DTAM-DM | Document Transfer And Manipulation – Document Manipulation | +| DTAM-TK | Document Transfer And Manipulation – ToKen interchange | + +| | | +|-------|----------------------------------------------------------------------------------| +| ECM | Error Correction Mode | +| ETS | European Telecommunication Standard | +| ETSI | European Telecommunications Standards Institute | +| FAX3 | Facsimile group 3 | +| FAX4 | Facsimile group 4 | +| FOD | Interchange Format and representation profile for ODA | +| FODA | Formal specification of ODA | +| FT | File Transfer | +| FTAM | File Transfer, Access and Manipulation | +| IEC | International Electrotechnical Commission | +| IPM | InterPersonal Messaging | +| ISDN | Integrated Services Digital Network | +| ISO | International Organization for Standardization | +| ISP | International Standardized Profile | +| ISR | Implementation Support Requirements | +| ITU-T | International Telecommunication Union – Telecommunication Standardization Sector | +| MCS | Multipoint Communication Service | +| MCU | Multipoint Control Unit | +| MHS | Message Handling System | +| MNP | MaNiPulation basic service | +| MPT | Multi-PoinTing basic service | +| MS | Message Store | +| MTS | Message Transfer System | +| N/A | Not Applicable | +| NM | Normal Mode | +| ODA | Open Document Architecture | +| OSI | Open Systems Interconnection | +| PNT | PoiNTing basic service | +| QOS | Quality of Service | +| ROA | Referenced Object Access | +| ROSE | Remote Operations Service Element | +| RTR | ReTRieval basic service | +| RTSE | Reliable Transfer Service Element | +| SAR | Storing-And-Retrieval basic service | +| SE | Service Element | +| STR | SToRing basic service | +| TE | Terminal Equipment | +| TK | ToKen exchange | +| TKI | ToKen-Interchange basic service | +| TM | Transparent Mode | + +# 5 Introduction to document communication basic services + +This Recommendation specifies services for document communication. Some of them are considered as basic services. More complex services, specified in other Recommendations, are defined in terms of the basic ones. In this Recommendation, a methodology for the specification of services is defined (see clause 9). However, it is only applied to basic services (see clause 10), while complex services are only introduced (see clause 6). + +Basic services use existing document and communication base Recommendations | International Standards and profiles. + +Two groups of basic services are considered: + +- basic services that, apart from being used for specifying complex services, can be implemented as stand-alone services, and then provided to users; +- basic services that can only be used for specifying complex services. + +A number is assigned to each Basic Service (BS). + +The basic services that belong to the first group are: + +- storing (BS 1); +- distribution (BS 2); +- retrieval (BS 3); +- storing-and-retrieval (BS 4); +- manipulation (BS 5). + +Storing and distribution basic services apply to full documents only, while retrieval, storing-and-retrieval and manipulation basic services apply to full documents and to document fragments. + +The basic services that belong to the second group are: + +- pointing (BS 6); +- multi-pointing (BS 7); +- token-interchange (BS 8). + +Pointing and multi-pointing basic services only apply to document fragments, while token-interchange basic service is independent of documents. + +There are some subset relationships between some of the basic services, but a complete hierarchy between them does not exist. The relationships are: + +- storing is a subset of distribution; +- storing is a subset of storing-and-retrieval; +- retrieval is a subset of storing-and-retrieval; +- storing-and-retrieval is a subset of manipulation; +- pointing is a subset of multi-pointing. + +Basic services are introduced in the following subclauses with a description and some examples. Then, a classification is given in 5.3. + +## 5.1 Basic services that can be stand-alone services + +### 5.1.1 Storing basic service + +#### 5.1.1.1 Description + +This basic service provides for storing one or more full documents from a communicating entity (sender) to a remote document store (recipient). The sender is provided with the ability to store (create) new documents at the recipient's communicating entity, but cannot read, delete or modify already stored documents. Before storing, the documents are located in the sender's local store. This service does not cover the case where both the sender and the recipient are different from the requesting communicating entity (third party transfer). + +#### **5.1.1.2 Examples of concrete applications** + +Examples of concrete applications are: + +- transfer of documents to a remote system; +- a remote storage service, where users store documents in a common remote server. + +### **5.1.2 Distribution basic service** + +#### **5.1.2.1 Description** + +This basic service provides for distribution of one or more full documents from a communicating entity (sender) to several remote document stores (recipients). This service is a generalization of the storing service in the case of more than one recipient. + +#### **5.1.2.2 Examples of concrete applications** + +Examples of concrete applications are: + +- document distribution service; +- distribution of electronic newsletters to registered subscribers. + +### **5.1.3 Retrieval basic service** + +#### **5.1.3.1 Description** + +This basic service provides for searching and retrieval, from a remote document store, of one or more full documents or document fragments. + +#### **5.1.3.2 Examples of concrete applications** + +Examples of concrete applications are: + +- read-only document server; +- system for remote consultation of documents. + +### **5.1.4 Storing-and-retrieval basic service** + +#### **5.1.4.1 Description** + +This basic service provides for both storing, into a remote document store, and retrieval, from a remote document store, of one or more full documents or document fragments. Stored documents or document fragments shall not be overwritten. + +Searching for one or more documents or document fragments is also provided by this service. + +This service is a superset of the retrieval basic service and of the storing basic service. However, it is not the joining of storing and retrieval basic services, since storing only applies to full documents, and storing-and-retrieval applies both to full documents and to document fragments. + +#### **5.1.4.2 Examples of concrete applications** + +Examples of concrete applications are: + +- storing and retrieval in a document server; +- joint composition of documents, where users are not allowed to modify existing text. + +### **5.1.5 Manipulation basic service** + +#### **5.1.5.1 Description** + +With this basic service, one communicating entity (client) accesses remotely to another communicating entity (the document store, or server) in order to manipulate one or more documents or document fragments. + +Manipulation includes searching and reading operations, like those provided by the retrieval basic service. + +#### **5.1.5.2 Examples of concrete applications** + +Examples of concrete applications are: + +- remote document editing; +- document reading, or browsing, to make comments on content. + +## **5.2 Basic services that cannot be stand-alone services** + +### **5.2.1 Pointing basic service** + +#### **5.2.1.1 Description** + +This basic service provides for a communicating entity to identify (to point to) a document fragment inside a document at a remote communicating entity. + +#### **5.2.1.2 Examples of concrete applications** + +Examples of concrete applications are: + +- to build a complex service like joint viewing of documents, where one user presents documents to another user; +- to provide the facility for two users to interchange views on documents; for example one user shows, to the remote user, specific parts of a document. + +### **5.2.2 Multi-pointing basic service** + +#### **5.2.2.1 Description** + +This basic service provides for a communicating entity to identify (to point to) a document fragment inside a document in several remote communicating entities. + +#### **5.2.2.2 Examples of concrete applications** + +Examples of concrete applications are: + +- to build a complex service like joint viewing of documents, where one user presents documents to several other users; +- to provide a complex service like joint editing of documents by several users, where, before modifications, affected document fragments are shown and discussed (for example, by associated telephone conversation). + +### **5.2.3 Token-interchange basic service** + +#### **5.2.3.1 Description** + +This basic service provides for application token interchange between two communicating entities. The token indicates which communicating entity has the turn to perform further operations. + +#### **5.2.3.2 Examples of concrete applications** + +Examples of concrete applications are: + +- to build a complex service, like two users jointly editing a document in an interactive way, where the token is used to interchange the turn between users; +- to build a complex service, like work flow guided document production, where a token is used to inform users about their turn to work on the document (for example, a travel order). + +## **5.3 Classification of basic services** + +Table 1 classifies the basic services taking into account: + +- services that can be implemented as stand-alone ones; +- services working on full documents and/or document fragments; a third case is services independent of documents; + +- type of operations provided: + - 1) reading: information is only searched and retrieved; + - 2) adding: information is added to the documents or to the document store; + - 3) modifying: information in the documents or document store is modified; +- one communicating entity associated to another communicating entity or one communicating entity associated to several communicating entities. + +The following abbreviations for the basic services are used in Table 1: + +- storing: STR; +- distribution: DST; +- retrieval: RTR; +- storing-and-retrieval: SAR; +- manipulation: MNP; +- pointing: PNT; +- multi-pointing: MPT; +- token-interchange: TKI. + +TABLE 1/T.190 + +**Classification of basic services** + +| | Basic services | | | | | | | | +|---------------------------------------|----------------|-----|-----|-----|-----|-----|-----|-----| +| | STR | DST | RTR | SAR | MNP | PNT | MPT | TKI | +| Can be stand-alone service | √ | √ | √ | √ | √ | | | | +| Can be used for complex services | √ | √ | √ | √ | √ | √ | √ | √ | +| Works on full documents | √ | √ | √ | √ | √ | | | | +| Works on document fragments | | | √ | √ | √ | √ | √ | | +| Independent of documents | | | | | | | | √ | +| Reading operations | | | √ | √ | √ | | | | +| Adding operations | √ | √ | | √ | √ | | | | +| Modifying operations | | | | | √ | | | | +| One to one communicating entities | √ | | √ | √ | √ | √ | | √ | +| One to several communicating entities | | √ | | | | | √ | | + +# 6 Introduction to document communication complex services + +Recommendations in this Series specify services for document communication. This Recommendation specifies basic services, clause 5 gives an introduction and clause 10 the formal definition of basic services. Complex services are defined in terms of basic ones and are formally specified in other Recommendations of this Series of Recommendations. + +Some of the possible complex services are introduced in this clause, these complex services are: + +- asynchronous document production; +- sequential document production; +- joint synchronous editing; +- joint document presentation/viewing. + +For each of these services, the following subclauses give a description and some service construction rules that highlight the basic services on which the complex service is founded and how these basic services are combined together. A figure is used for this purpose. Finally, one or more examples of concrete applications to emphasize the interest of having considered such a complex service are given. + +## 6.1 Asynchronous document production + +### 6.1.1 Description + +Several users have remote access to a common central store in order to edit a document. Every user is involved in the editing process whose main objective is the production of a finalised document. They may all have needs to access the shared document in no specific order. They can have access to the document and document fragment at the same time and are not necessarily informed about the changes carried out to the document by the other users. This service can have several options, two of these options are: + +- only one user can at a time manipulate one given document fragment; +- it is possible for several users to manipulate the same document fragment at the same time, in this case each of them works on a copy of the given fragment. + +### 6.1.2 Service construction rules + +Figure 1 gives an overview of the asynchronous document production complex service. + +![Diagram of asynchronous document production showing multiple clients (Client 1, Client 2, Client N) interacting with a central Server (Store) containing a Document. Arrows indicate document manipulation, and a dashed line indicates document access.](3fa8bfee86764e3c3a1a6fbbe61bbd52_img.jpg) + +The diagram illustrates the asynchronous document production service. It shows three clients (Client 1, Client 2, and Client N) interacting with a central Server (Store). The Server (Store) is represented by a rectangle containing a cylinder icon labeled 'Document'. Client 1 and Client 2 have solid arrows pointing to the Server, while Client N has a dashed arrow. A legend at the bottom left shows a cylinder icon for 'Document' and a solid arrow for 'Document manipulation'. The text 'T0821200-95/d01' is located at the bottom right of the diagram. + +Diagram of asynchronous document production showing multiple clients (Client 1, Client 2, Client N) interacting with a central Server (Store) containing a Document. Arrows indicate document manipulation, and a dashed line indicates document access. + +FIGURE 1/T.190 +**Asynchronous document production** + +The asynchronous document production complex service is based on the following basic service: + +- manipulation. + +The manipulation basic service is used by every user to manipulate the document remotely. + +### **6.1.3 Example of concrete applications** + +- Several users are in charge of the production of one document, for instance functional or implementation specifications, manuals, guides, etc. These users can be several experts from different companies or from different units of the same company remotely located. Each of them may have needs to: + - read some parts of the document in order to get or receive some information; + - add new parts to the document; + - update some parts of the document. + +## **6.2 Sequential document production** + +### **6.2.1 Description** + +Several users are involved in the production of a document, but at one given moment, only one user has access to the document and can manipulate it. At the end of his contribution, the document is sent to the next user for further manipulation. The choice of this next user is made following several kinds of rules: + +- fully deterministic rules: it is perfectly known who will be the next user to access and manipulate the document; +- rules which provide a list of users from which the current manipulating user can choose who will be the next user to access and manipulate the document. + +Those rules can be defined by: + +- the application only; +- the application using some information contained in the document itself (for instance, the list of the participants). + +This service provides the mechanisms to warn the users when they are in turn to access and manipulate the document. + +### **6.2.2 Service construction rules** + +Depending on the document location and the number of stores, the three following cases are considered: + +- Local manipulation of the document: Every user manipulates the document locally, the document is transferred between the user's local stores. +- Remote manipulation of the document on different stores: Every user manipulates the document remotely; the document is transferred between the document stores, each of them being accessible by only one user. +- Remote manipulation of the document on a central store: Every user manipulates the document remotely; the document is located in a central store to which every user has access. + +Other cases are also possible, which are in fact all the possible combinations of the three cases above. + +#### **6.2.2.1 Local manipulation of the document** + +In this case of the sequential document production complex service, every user manipulates the document locally, the document is transferred between the user's local stores. Figure 2 gives an overview of this case of the sequential document production complex service. + +In this case, the sequential document production complex service is based on the following basic service: + +- storing. + +The storing service is used to transfer the document between the local stores. Manipulating the document is a local matter. + +![Diagram illustrating sequential document production with local manipulation. It shows three users (User 1, User 2, User N) and three document stores (cylinders). Solid arrows indicate document storing between adjacent stores. Dashed arrows indicate optional document storing from each user to their respective store and from the final store back to the first user. A legend defines the symbols: a cylinder for 'Document', a solid arrow for 'Document storing', and a dashed arrow for 'Optional document storing'.](b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg) + +T0821210-95/d02 + +Diagram illustrating sequential document production with local manipulation. It shows three users (User 1, User 2, User N) and three document stores (cylinders). Solid arrows indicate document storing between adjacent stores. Dashed arrows indicate optional document storing from each user to their respective store and from the final store back to the first user. A legend defines the symbols: a cylinder for 'Document', a solid arrow for 'Document storing', and a dashed arrow for 'Optional document storing'. + +FIGURE 2/T.190 + +##### Sequential document production: local manipulation of the document + +#### 6.2.2.2 Remote manipulation of the document on different stores + +In this case of the sequential document production complex service, every user manipulates the document remotely, the document is transferred between the document stores, each of them being accessible by only one user. Figure 3 gives an overview of this case of the sequential document production complex service. + +In this case, the sequential document production complex service is based on the following basic services. + +- manipulation; +- storing; +- token-interchange (optional). + +The manipulation basic service is used by the users to manipulate the document remotely, and the storing basic service is used to transfer the document between the document stores. When the token-interchange basic service is used, the purpose of the token is to know which user has access to the document. + +#### 6.2.2.3 Remote manipulation of the document on a central store + +In this case of the sequential document production complex service, every user manipulates the document remotely, the document is located in a central store to which every user has remote access. Figure 4 gives an overview of the sequential document production complex service. + +In this case, the sequential document production complex service is based on the following basic services: + +- manipulation; +- token-interchange (optional). + +The manipulation basic service is used by the users to manipulate the document remotely. When the token-interchange basic service is used, the purpose of the token is to know which user has access to the document. + +![Diagram illustrating sequential document production with remote manipulation across multiple servers and clients.](5b8a756d9a71c35f17db8bcb90b438a3_img.jpg) + +The diagram illustrates a sequential document production process involving multiple servers and clients. The components and their interactions are as follows: + +- Components:** + - Clients:** Client 1, Client 2, and Client N (represented by circles). + - Servers:** Server 1 (Store 1), Server 2 (Store 2), and Server N (Store N) (represented by rectangles containing a document icon). +- Legend:** + - Document:** Represented by a cylinder icon. + - Document manipulation:** Represented by a lightning bolt arrow. + - Document storing:** Represented by a solid straight arrow. + - Optional document storing:** Represented by a dashed straight arrow. + - Optional token:** Represented by a small circle. +- Interactions:** + - Client 1 performs document manipulation on Server 1 (Store 1). + - Client 2 performs document manipulation on Server 2 (Store 2) and has an optional token. + - Client N performs document manipulation on Server N (Store N). + - Document storing flows from Server 1 to Server 2, and from Server 2 to Server N. + - Optional document storing flows from Server 1 to Server N. + +T0821220-95/d03 + +Diagram illustrating sequential document production with remote manipulation across multiple servers and clients. + +FIGURE 3/T.190 +Sequential document production: remote manipulation +of the document on different stores + +### 6.2.3 Examples of concrete applications + +- Employees of big companies or Administrations usually belong to a hierarchical structure reflecting the different responsibility levels. Therefore, strict administrative rules require that some documents (for instance letters, reports, official requests, official claims, etc.) follow that hierarchy road before being received by the person(s) to whom the document is intended. At each level, every user can: + - 1) update the document; + - 2) add some comments; + - 3) give personal opinions, conclusions; + - 4) move the document to another level of the hierarchy. +- In the standardization world, final draft Recommendations | International Standards on the way to be approved, still have to be checked out by several international expert groups and this in a previously established and more or less strict order. The sequential document production complex service can be used for this purpose. + +![Diagram illustrating sequential document production: remote manipulation of the document on a central store. The diagram shows three clients (Client 1, Client 2, Client N) interacting with a central Server (Store). Client 1 sends a document manipulation request to the Server. Client 2 sends a document manipulation request to the Server, with an optional token (small circle) indicating it is the active manipulator. Client N sends a document manipulation request to the Server. The Server (Store) contains a document icon. A legend defines the symbols: a cylinder icon for 'Document', a lightning bolt arrow for 'Document manipulation', and a small circle for 'Optional token'. The identifier T0821230-95/d04 is located at the bottom right of the diagram.](e69b9188aa2c14ec6b21c83f711fef65_img.jpg) + +T0821230-95/d04 + +Diagram illustrating sequential document production: remote manipulation of the document on a central store. The diagram shows three clients (Client 1, Client 2, Client N) interacting with a central Server (Store). Client 1 sends a document manipulation request to the Server. Client 2 sends a document manipulation request to the Server, with an optional token (small circle) indicating it is the active manipulator. Client N sends a document manipulation request to the Server. The Server (Store) contains a document icon. A legend defines the symbols: a cylinder icon for 'Document', a lightning bolt arrow for 'Document manipulation', and a small circle for 'Optional token'. The identifier T0821230-95/d04 is located at the bottom right of the diagram. + +FIGURE 4/T.190 +**Sequential document production: remote manipulation +of the document on a central store** + +## 6.3 Joint synchronous editing and remote presentation + +### 6.3.1 Using MCS + +#### 6.3.1.1 Description + +This complex service consists on the remote editing of documents by several users in an interactive way. Basically, only one user can manipulate the document, while the others can confirm the result of these manipulations. A token control may be supported to handle which user can manipulate the document at a time. + +This complex service is an exceptional case of the multipoint communication. + +In this configuration, document process works on each terminal, and the same copy of the document to be manipulated is stored on each terminal. In order to have multipoint communication, there exist one or more Multipoint Control Units (MCUs). Each MCU is connected to other MCUs or terminals. On each MCU, the protocol for multipoint communication (that is MCS: Multipoint Communication Service) is invoked, which delivers the PDU for manipulation or pointing from one sender to all the other recipients or all the designated recipients. + +If a terminal has the manipulation token, then the terminal works as client, while the others work as servers. If the terminal who has the manipulation token releases the token after token procedure, then the role of the terminal changes from client to server. In this case, each terminal plays a role of both client and server sequentially. On the other hand, MCU may play a role of neither client nor server at the basic service level defined in this Recommendation. MCU may only deliver the PDU to provide multipoint association. Therefore, MCS provides basic services with terminal-to-terminal association (or end-to-end association) on top of multipoint association. + +Hence, this complex service supports multipoint joint editing and remote presentation by combining basic services with MCS. + +#### 6.3.1.2 Service construction rules + +Figures 5 and 6 give an overview of the complex service joint synchronous editing and remote presentation using MCS. + +Figure 5 indicates the situation where terminal 3 has a manipulation token. + +Figure 6 indicates the result when the manipulation token has moved from terminal 3 to terminal 1 after token procedure. + +![Diagram of joint synchronous editing and remote presentation using MCS with terminal 3 holding the token.](844077b3034f0030b404207db0ad76b4_img.jpg) + +The diagram illustrates a system architecture for joint synchronous editing and remote presentation using MCS. It features a central MCU (Master Control Unit) connected to four terminals: Client 1 (terminal 1), Client 2 (terminal 2), Server 1 (terminal 3), and Client n-1 (terminal n). Each terminal contains a document icon. The MCU is connected to each terminal via a line. Arrows indicate the flow of data: Client 1 and Client 2 have double-headed arrows to the MCU, indicating bidirectional communication. Client n-1 has a single-headed arrow pointing to the MCU. Server 1 (terminal 3) has a single-headed arrow pointing to the MCU, and a black dot (representing a token) is located on the line between Server 1 and the MCU. A legend at the bottom left defines the symbols: a cylinder icon for 'Document', a solid arrow for 'Document manipulation', a dashed arrow for 'Pointing', a solid line for 'Terminal-to-terminal association', and a black dot for 'Token'. The text 'T0823590-95/d05' is located at the bottom right of the diagram area. + +Client 1 +terminal 1 + +Client 2 +terminal 2 + +Server 1 +terminal 3 + +Client n-1 +terminal n + +MCU + +Document + +Document manipulation + +Pointing + +Terminal-to-terminal association + +Token + +T0823590-95/d05 + +Diagram of joint synchronous editing and remote presentation using MCS with terminal 3 holding the token. + +FIGURE 5/T.190 + +**Joint synchronous editing and remote presentation using MCS +(In the case that terminal 3 has the manipulation token)** + +The complex service joint synchronous editing and remote presentation using MCS is based on the following basic services: + +- manipulation; +- token-interchange; +- pointing. + +![Diagram illustrating Joint synchronous editing and remote presentation using MCS. The diagram shows a central MCU connected to four terminals: Server 1 (terminal 1), Client 1 (terminal 2), Client 2 (terminal 3), and Client n-1 (terminal n). A token is shown on Server 1. Arrows indicate document manipulation and pointing between the MCU and the terminals. A legend defines the symbols: Document (cylinder), Document manipulation (double arrow), Pointing (single arrow), Terminal-to-terminal association (solid line), and Token (black dot).](c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg) + +Diagram illustrating Joint synchronous editing and remote presentation using MCS. The diagram shows a central MCU connected to four terminals: Server 1 (terminal 1), Client 1 (terminal 2), Client 2 (terminal 3), and Client n-1 (terminal n). A token is shown on Server 1. Arrows indicate document manipulation and pointing between the MCU and the terminals. A legend defines the symbols: Document (cylinder), Document manipulation (double arrow), Pointing (single arrow), Terminal-to-terminal association (solid line), and Token (black dot). + +Diagram illustrating Joint synchronous editing and remote presentation using MCS. The diagram shows a central MCU connected to four terminals: Server 1 (terminal 1), Client 1 (terminal 2), Client 2 (terminal 3), and Client n-1 (terminal n). A token is shown on Server 1. Arrows indicate document manipulation and pointing between the MCU and the terminals. A legend defines the symbols: Document (cylinder), Document manipulation (double arrow), Pointing (single arrow), Terminal-to-terminal association (solid line), and Token (black dot). + +FIGURE 6/T.190 + +##### **Joint synchronous editing and remote presentation using MCS (In the case that the manipulation token moves from terminal 3 to terminal 1)** + +The manipulation basic service is used by the users to manipulate remote documents, and the pointing basic service is used to show the selection of document fragments to remote users for the remote presentation application. + +When the token-interchange basic service is used, the purpose of the token is to know which user has access to the document. + +#### 6.3.1.3 Example of concrete applications + +- Typical examples of concrete applications are document conference and remote education: + - 1) In the case of document conferencing, two or more users geographically distributed can edit the shared document on a real-time basis. If one user edits some part of the shared document, the events for manipulation such as “create”, “delete”, etc., are delivered to the other terminal. These recipient terminals have the same result by editing the shared document stored locally. + - 2) In the case of remote education, one teacher or speaker who has the pointer token can point a part of the document, or change the displayed page. On the other hand, the student or the audience can see the same part of the document or the same page synchronously. + +### 6.3.2 Without MCS + +#### 6.3.2.1 Joint synchronous editing + +##### 6.3.2.1.1 Description + +This service consists of the remote editing of a document by several users in an interactive way (all of them are aware of the editing process, but not necessarily always online). There is no specific order in which the users access and manipulate the document. + +Several copies of the document may exist. Only one of these copies can be manipulated, that can be seen as the master copy and is located in a central store to which every user has remote access. Local copies of the document may exist as well, that can be useful to avoid data transfer overheads when some users view the document. + +Only one user can at a time manipulate the document, while the others optionally view. A token is used to know which user is in turn to manipulate the document. Furthermore, the central store sends updates of the document to the other users (the viewers). + +##### 6.3.2.1.2 Service construction rules + +Figure 7 gives an overview of the joint synchronous editing without MCS complex service. + +![Diagram of joint synchronous editing without MCS](e7c6a6e4c3047dac05a3b92e396e9794_img.jpg) + +The diagram illustrates the architecture for joint synchronous editing without MCS. It shows three clients (Client 1, Client 2, and Client N) interacting with a central Server (Store). Each client has an optional local copy of the document, represented by a cylinder icon. Client 1 and Client 2 are shown with solid arrows pointing to the Server (Store), indicating document manipulation. Client N is shown with a dashed arrow pointing to the Server (Store), indicating viewing. A token, represented by a black dot, is shown next to Client 2, indicating it is the user's turn to manipulate the document. The Server (Store) is represented by a rectangle containing a cylinder icon. A legend at the bottom left defines the symbols: a cylinder for 'Document', a solid arrow for 'Document manipulation', a black dot for 'Token', and a dashed arrow for 'Optional local copies of the document'. The identifier 'T0823610-95/d07' is located at the bottom right of the diagram. + +Diagram of joint synchronous editing without MCS + +FIGURE 7/T.190 + +#### Joint synchronous editing without MCS + +### 6.3.3 Example of concrete applications + +- Two users, remotely located, edit at the same time the same document. Alternatively, one user modifies the document while the other user views the document. Each user is immediately informed (updates are sent to the user) and can view the changes carried out by the other user. + +## 6.4 Joint document presentation/viewing + +### 6.4.1 Description + +This service consists of the remote presentation or joint viewing of a document, where a user (the presenter) broadcasts the content of a document to the other users (the viewers). Before presentation starts, every user has a local copy of the document, otherwise a copy is sent to the users not having one. + +### 6.4.2 Service construction rules + +Depending on the number of users who can present the document to the other users, the two following cases are considered: + +- Only one user can present the document to the others. +- More than one user can present the document to the other users, but at a given time, only one user presents while the others view. + +Other cases are also possible, that correspond to all other possible values of the number of users that can present the document. + +#### 6.4.2.1 Only one user can present + +In this case of the joint document presentation/viewing complex service, only one user is provided with the ability to present the document to the other users. + +Figure 8 gives an overview of this case of the joint document presentation/viewing complex service. + +![Diagram illustrating the joint document presentation/viewing service where only one user can present. A Presenter (circle with a document icon) sends data (arrows) to Viewer 1, Viewer 2, and Viewer N (circles with document icons). Viewer 2 and Viewer N are connected by a dashed line. A legend shows a document icon and arrows pointing to the text 'Pointing (N = 1) or Multi-pointing (N > 1)'. The identifier T082 1250-95/d08 is at the bottom right.](f1fbb1287d999c7034742de35bdab836_img.jpg) + +Diagram illustrating the joint document presentation/viewing service where only one user can present. A Presenter (circle with a document icon) sends data (arrows) to Viewer 1, Viewer 2, and Viewer N (circles with document icons). Viewer 2 and Viewer N are connected by a dashed line. A legend shows a document icon and arrows pointing to the text "Pointing (N = 1) or Multi-pointing (N > 1)". The identifier T082 1250-95/d08 is at the bottom right. + +Diagram illustrating the joint document presentation/viewing service where only one user can present. A Presenter (circle with a document icon) sends data (arrows) to Viewer 1, Viewer 2, and Viewer N (circles with document icons). Viewer 2 and Viewer N are connected by a dashed line. A legend shows a document icon and arrows pointing to the text 'Pointing (N = 1) or Multi-pointing (N > 1)'. The identifier T082 1250-95/d08 is at the bottom right. + +FIGURE 8/T.190 + +**Joint document presentation/viewing: only one user can present** + +In this case, the joint document presentation/viewing complex service is based on the following basic services: + +- pointing (if there is only one viewer) or multi-pointing (if there are more than one viewer); +- storing (optional). + +The pointing and multi-pointing basic services are used because the presenter needs to identify document fragments to one or several viewers, respectively. The storing basic service is optional, only used if some users do not have a copy of the document before presentation starts. + +#### 6.4.2.2 All users can present + +In this case of the joint document presentation/viewing complex service, all users are provided with the ability to present the document to the other users, but at a given time, only one user presents while the others view. + +Figure 9 gives an overview of this case of the joint document presentation/viewing complex service. + +![Diagram of joint document presentation/viewing: all users can present to the other users.](088921fa3f5a44c8551815122517eefd_img.jpg) + +The diagram illustrates a joint document presentation/viewing scenario where all users can present. On the left, a circle labeled 'Presenter' is shown with a small circle (Token) above it and a cylinder (Document) below it. Three solid arrows point from the Presenter to three circles on the right labeled 'Viewer 1', 'Viewer 2', and 'Viewer N'. Each viewer circle has a small cylinder (Document) next to it. A dashed vertical line connects Viewer 2 and Viewer N. A legend at the bottom left defines the symbols: a cylinder for 'Document', a branching arrow for 'Pointing (N = 1) or Multi-pointing (N > 1)', and a small circle for 'Token'. The text 'T0821260-95/d09' is located at the bottom right of the diagram area. + +Diagram of joint document presentation/viewing: all users can present to the other users. + +FIGURE 9/T.190 + +**Joint document presentation/viewing: all users can present to the other users** + +In this case, the joint document presentation/viewing complex service is based on the following basic services: + +- pointing (if there is only one viewer) or multi-pointing (if there are more than one viewer); +- token-interchange; +- storing (optional). + +The pointing and multi-pointing basic services are used because the presenter needs to identify document fragments to one or several viewers, respectively. The purpose of the token is to know which user is in turn to present the document. The storing basic service is optional, only used if some users do not have a copy of the document before presentation starts. + +### **6.4.3 Example of concrete applications** + +- One or more experts submit the conclusions of a report to other experts. A remote presentation of the report, using text and graphics, can be done. Then, a discussion can take place, supported for example by a telephone conversation. + +# **7 Document aspects** + +This Recommendation specifies services for document communication. Then, two aspects are considered: + +- document aspects; +- communication aspects. + +This clause specifies the document aspects of the services. Communication aspects are specified in clause 8. + +## **7.1 Introduction** + +This Recommendation considers the ODA Recommendations and International Standards, T.410-Series of Recommendations | ISO/IEC 8613, jointly developed by ITU and ISO, as the method for representing and interchanging. Then, services specified in this Recommendation shall apply to ODA documents. + +Documents are intended to be handled by means of communication applications. Handling of documents includes interchanging, storing, retrieving and manipulating full documents and document fragments. + +What in this Recommendation is called a full document, refers to a document as specified in the ODA Recommendations | International Standards. Document fragments, and the ways to identify them are specified in ITU-T Rec. T.422 | ISO/IEC 8613-12. + +Operations on ODA document fragments are specified in the abstract interface for the manipulation of ODA documents, ITU-T Rec. T.411 | ISO/IEC 8613-1. This abstract interface is used in conjunction with the DTAM-DM services, as explained in clause 8. + +Documents can be stored in a server in any format. However, servers shall provide an ODA interface to the documents. + +The rest of this clause describes the existing ODA Document Application Profiles (DAPs) (see 7.2), and specifies which of them and how shall be used by the services specified in this Recommendation (see 7.3). + +## **7.2 ODA DAPs** + +A Document Application Profile (DAP) is a standardized implementable subset of the ODA features, intended for easy interworking of ODA applications. + +There are two groups of ODA DAPs: + +- DAPs for document processing applications; +- DAPs for image applications. + +Every DAP is part 1 of a different International Standardized Profile (ISP), published by ISO/IEC. For every ISP, there are two more parts. The second one includes the Implementation Support Requirements (ISR), while the third one includes the Abstract Test Suite (ATS). + +### **7.2.1 DAPs for document processing applications** + +The three existing DAPs for document processing applications are identified as: + +- FOD011: Simple document structure – Character content architecture only, ISO/IEC ISP 10610-1; +- FOD026: Enhanced document structure – Character, raster graphics and geometric graphics content architectures, ISO/IEC ISP 11181-1; +- FOD036: Extended document structure – Character, raster graphics and geometric graphics content architectures, ISO/IEC ISP 11182-1. + +They form a hierarchy where FOD011 has the lowest functionality. FOD011 is a subset of FOD026, while FOD026 is a subset of FOD036. + +NOTE – While the mentioned DAPs were published in 1993, parts 2 and 3 of the ISPs have different status. The most stable drafts are those related to FOD026. + +FOD011 supports simple logical and layout structures and character only content type. FOD026, in turn, supports complex logical and layout structures, including footnotes and multi-columns; furthermore, it also allows geometric graphics and raster graphics content types. Finally, FOD036 provides for the interchange of even more complex multimedia documents with features such as tables, forms, and overlapping illustrations. + +### **7.2.2 DAPs for image applications** + +Concerning image applications, two profiles are currently being defined. They are intended for the interchange of large format raster images between equipment designed for image processing. + +The two DAPs are known as (see Appendix III): + +- FOD112; +- FOD126. + +FOD112 only contains raster images, while FOD126 allows, in addition, more complex structures and character and geometric graphics content. + +NOTE – FOD112 is at draft status, while FOD126 still needs further development. + +## **7.3 Use of ODA DAPs** + +Most of the basic services, and all the complex services, specified in this Recommendation apply to documents. Those documents shall follow the ODA Recommendations | International Standards and, in particular, they shall conform to one standardized DAP. + +This Recommendation only considers DAPs for document processing applications. Then, documents shall conform to one of the following DAPs: + +- FOD011; +- FOD026; +- FOD036. + +When establishing application associations for the services specified in this Recommendation, the DAP level will be negotiated. + +# **8 Communication aspects** + +After the consideration of document aspects in clause 7, this clause specifies the communication aspects of the services. + +## 8.1 Introduction + +To allow the construction of communication applications which are modular and easy to extend, it is highly desirable to keep the applications as much as possible independent from the underlying communication means. It is outside the scope of this Recommendation to specify new protocols or network components, and this Recommendation will not change existing protocol or network specifications. + +This Recommendation takes into account existing standardized communication modules which are used for document communication. + +This clause summarizes the characteristics of communication modules to be used by services of this Recommendation. The newest results of standardization bodies in this area, for example the combined use of DFR and DTAM-DM or the support of access and manipulation of document fragments, are taken into consideration. + +This clause also specifies how the communication modules shall be used, and which general restrictions shall be applied, in the services of this Recommendation. + +The following communication modules are dealt with in this clause: + +- Document Filing and Retrieval (DFR); +- Document Transfer And Manipulation – Bulk Transfer – Normal Mode (DTAM-BT-NM); +- Document Transfer And Manipulation – Document Manipulation (DTAM-DM); +- Document Transfer And Manipulation – ToKen Exchange (DTAM-TK); +- Combined use of DFR and DTAM-DM (DFR/DTAM-DM); +- Message Handling Systems (MHS); +- Multipoint Communication Service (MCS). + +Further communication modules which can be used by services of this Recommendation for ODA document communication are described in Appendix I. + +Whenever a service of this Recommendation makes use of one of these communication modules, the rules given in the corresponding Recommendations or Standards shall apply. + +Specific restrictions of communication modules and dynamic constraints on them, required by dedicated services of this Recommendation are defined in clause 10. + +For each of the identified communication modules above, subsequent subclauses give information about the following, as far as it is relevant for the services of this Recommendation: + +- description; +- services, protocols and profiles; +- use for document communication. + +## 8.2 Document Filing and Retrieval (DFR) + +### 8.2.1 Description + +The DFR communication module provides for managing documents and other objects inside remote document stores in distributed office systems. An information model describes the hierarchical structure of document stores, an operational model defines the abstract operations to be performed on document stores. + +DFR communication applications are based on the end-to-end communication principle. The communicating entities have a client/server relationship. + +### 8.2.2 Services, protocols and profiles + +The DFR abstract services are contained in the DFR Service Element (SE) and are defined in ISO/IEC 10166-1. + +The DFR protocol is specified in ISO/IEC 10166-2. The DFR protocol makes use of the Association Control Service Element (ACSE), the Remote Operation Service Element (ROSE) and the presentation service. The Reliable Transfer Service Element (RTSE) can be used optionally. + +Two groups of Application profiles for DFR (ADF), which define functional subsets of DFR, are specified in ISO/IEC ISP 12069. They are: + +- ADF1; +- ADF2. + +The first group of application profiles, ADF1, is intended to be used for common filing and retrieval applications, and contains the following profiles: + +- ADF11 (read only profile): The DFR operations included in this profile allow only to retrieve stored documents or to search for documents, but they do not allow to store new information or to change existing information. +- ADF12 (archiving profile): The DFR operations included in this profile allow to store new documents and to read them, but they do not allow changes to stored information. +- ADF13 (document store manipulation profile): All DFR operations are included in this profile. + +The ADF1 profiles are defined hierarchically with ADF11 having the lowest functionality and ADF13 the highest. The ADF11 read only profile is a subset of the ADF12 archiving profile, and the ADF12 archiving profile is a subset of the ADF13 document store manipulation profile. + +The second group of application profiles, ADF2, is intended to be used for remote store management, and contains the following profiles: + +- ADF21 (simple management profile): This profile provides a minimum functionality for list and search operations to support other inner document handling applications. +- ADF22 (full management profile): This profile provides for list, search and manipulation (but without read and create) operations, to support other document handling applications. + +The ADF21 simple management profile is a subset of the ADF22 full management profile. + +### **8.2.3 Use for document communication** + +DFR is designed for the management of document stores with defined structures in distributed environments. DFR communicating entities have to know and maintain the store structures. DFR is used to transfer all kinds of documents, because the document contents are handled transparently. + +The DFR ADF profiles are to be combined with DTAM-DM AOD1 profiles (see 8.4.2) for applications that provide for the possibility of working on document stores and also on document fragments inside the documents. This combination shall be done by the communication applications using these profiles. + +## **8.3 Document Transfer And Manipulation – Bulk Transfer – Normal Mode (DTAM-BT-NM)** + +### **8.3.1 Description** + +The DTAM-BT-NM communication module is used to transfer documents between two communicating entities. + +DTAM-BT-NM is designed as common protocol platform for telematic services. DTAM-BT-NM communication applications are based on the end-to-end communication principle. DTAM-BT-NM allows the negotiation of application capabilities between communicating entities during the association establishment phase. + +### **8.3.2 Services, protocols and profiles** + +The DTAM-BT-NM services are contained in the DTAM SE and are subdivided into several functional units. DTAM-BT-NM makes use of the DTAM association use control functional unit for association establishment and termination, the DTAM capability functional unit for capability negotiation purposes, and the DTAM document bulk transfer functional unit for the data transfer phase. + +The DTAM-BT-NM protocol makes use of RTSE, ACSE and the presentation service. + +DTAM-BT-NM is defined in Recommendation T.522. + +### **8.3.3 Use for document communication** + +DTAM-BT-NM is used to transfer complete ODA documents. DAP levels, specifying the degree of complexity of the ODA documents, among other application capabilities, can be negotiated during the association establishment phase. + +## **8.4 Document Transfer And Manipulation – Document Manipulation (DTAM-DM)** + +### **8.4.1 Description** + +The DTAM-DM communication module is used to manipulate document fragments of documents at a remote communicating entity. + +DTAM-DM communication applications are based on the end-to-end communication principle. DTAM-DM allows the negotiation of application capabilities between communicating entities during the association establishment phase. + +### **8.4.2 Services, protocols and profiles** + +The DTAM-DM abstract services are contained in the DTAM-DM SE and are defined in Recommendation T.435. + +The DTAM-DM protocol is specified in Recommendation T.436. The DTAM-DM protocol makes use of ACSE, ROSE and the presentation service. + +Three manipulation levels for DTAM-DM abstract services, which define functional subsets of DTAM-DM, are specified in Recommendation T.436: + +- Basic read only level: The DTAM-DM abstract operations included in this level allow only to get and search document fragments, but they do not allow to add new information or to change existing information. +- Basic manipulation level: The DTAM-DM abstract operations included in this level allow to get and search document fragments and, additionally, to add new information, to delete or to change information. +- Extended level: All DTAM-DM abstract operations on document fragments are included in this level. + +The manipulation levels are defined hierarchically with the basic read only level having the lowest functionality and the extended level the highest. The basic read only level is a subset of the basic manipulation level, and the basic manipulation level is a subset of the extended level. + +The DTAM-DM abstract point service, which allows to identify document fragments, is optionally available in each manipulation level. + +An abstract interface for the manipulation of ODA documents is defined in ITU-T Rec. T.413 | ISO/IEC 8613-3, that specifies how to manipulate ODA document fragments. + +Two groups of Application profiles for ODA (AOD), which define functional subsets of operations of the abstract interface for the manipulation of ODA documents, are specified in ISO/IEC ISP AODnn. They are: + +- AOD1; +- AOD2. + +The first group of application profiles, AOD1, whose abstract interface operations are intended to be used in conjunction with the corresponding abstract services of DTAM-DM, contains the following profiles: + +- AOD11 (DTAM/Read-only profile): Abstract interface operations included in this profile are intended for reading and searching document fragments. +- AOD12 (DTAM/Insert profile): Abstract interface operations included in this profile are intended for reading, searching, creating, copying and reserving document fragments. +- AOD13 (DTAM/Manipulation profile): All abstract interface operations for manipulating document fragments are included in this profile. + +The AOD1 profiles are defined hierarchically with AOD11 having the lowest functionality and AOD13 the highest. The AOD11 DTAM/Read-only profile is a subset of the AOD12 DTAM/Insert profile, and the AOD12 DTAM/Insert profile is a subset of the AOD13 DTAM/Manipulation profile. + +A mapping of operations and operation arguments between the abstract interface for manipulation of ODA documents and the DTAM-DM abstract services is provided in Annex A of ITU-T Rec. T.413 | ISO/IEC 8613-3. + +The second group of application profiles, AOD2, is intended to be used in conjunction with Message Handling Systems (MHS), and is described in 8.7. + +### **8.4.3 Use for document communication** + +DTAM-DM is used for the remote interactive manipulation of ODA documents. DTAM-DM abstract services are aligned and combined with the operations of the abstract interface for the manipulation of ODA documents. + +The DTAM-DM AOD1 profiles are to be combined with DFR ADF profiles (see 8.2.2) for applications that provide for the possibility of working on a document store and also on document fragments inside the documents. This combination shall be done by the communication applications using these profiles. + +## **8.5 Document Transfer And Manipulation – ToKen Exchange (DTAM-TK)** + +### **8.5.1 Description** + +The DTAM-TK communication module is used to synchronize two communicating entities through the exchange of an application token. + +DTAM-TK communication applications are based on the end-to-end communication principle. + +### **8.5.2 Services, protocols and profiles** + +The DTAM-TK abstract services are contained in the DTAM-TK SE and are defined in Recommendation T.435. + +The DTAM-TK protocol is specified in Recommendation T.436. The DTAM-TK protocol makes use of ROSE and the presentation service. + +### **8.5.3 Use for document communication** + +DTAM-TK is used to synchronize communicating entities in document communication applications. + +## **8.6 Combined use of DFR and DTAM-DM (DFR/DTAM-DM)** + +### **8.6.1 Description** + +The DFR/DTAM-DM communication module combines DFR and DTAM-DM functionality. + +In such a combined application, DFR is used for remote document store management and DTAM-DM provides for the remote interactive manipulation of the documents inside the document store. + +DFR/DTAM-DM communication applications are based on the end-to-end communication principle. The communicating entities have a client/server relationship. + +### **8.6.2 Services, protocols and profiles** + +The statements in 8.2.2 about “DFR services, protocols and profiles”, and 8.4.2 about “DTAM-DM services, protocols and profiles” apply. + +Only one application entity, which includes the DFR SE and the DTAM-DM SE, is necessary in the communicating entities. The communication link between the two communicating entities may be established either through one DFR-Bind or one DTAM-DM-Bind operation. + +The DTAM-DM abstract operation DM-DOCUMENT-LIST shall not be used in the DFR/DTAM-DM communication module; the DFR List and DFR Search abstract operations are to be used instead. + +### **8.6.3 Use for document communication** + +DFR/DTAM-DM is used for the remote document store manipulation and management together with the remote interactive manipulation of documents inside the document store. + +The DFR ADF profiles (see 8.2.2) are to be combined with the DTAM-DM AOD1 profiles (see 8.4.2). Clause 10 specifies the rules and restrictions on how to combine them to be used within the basic services of this Recommendation. + +## **8.7 Message Handling Systems (MHS)** + +### **8.7.1 Description** + +The MHS communication module is used to distribute messages from one communicating entity to one or more remote communicating entities. + +MHS is based on the store-and-forward transmission principle in conjunction with the possibility of multi-addressing. + +### **8.7.2 Services, protocols and profiles** + +The MHS services and protocols are defined and specified in CCITT X.400-Series of Recommendations | ISO/IEC 10021. + +Two groups of Application profiles for MHS (AMH), which define functional subsets of MHS, are specified in ISO/IEC ISP 10611 and ISO/IEC ISP 12062. They are: + +- AMH1; +- AMH2. + +The first group of application profiles, AMH1, is intended to be used for common messaging, and contains the following profiles: + +- AMH11: Message transfer (P1); +- AMH12: MTS access (P3); +- AMH13: MS access (P7). + +The group of AMH1 profiles are independent of the content of the interchanged messages. + +The second group of application profiles, AMH2, is intended to be used for InterPersonal Messaging (IPM), and contains the following profiles: + +- AMH21: Message content; +- AMH22: Message transfer (P1); +- AMH23: MTS access (P3); +- AMH24: MS access (P7). + +The group of AMH2 profiles apply to a particular message content, the IPM content. + +One group of Application profiles for ODA (AOD), which defines functional subsets of operations of the abstract interface for the manipulation of ODA documents is specified in ISO/IEC ISP AODnn, and is intended to be used in conjunction with MHS. + +This group of application profiles, AOD2, contains only one profile: + +- AOD23 (MHS/Manipulation profile): The operations from the abstract interface for the manipulation of ODA documents included in this profile are intended for manipulating documents. + +The AOD23 MHS/Manipulation profile has the maximum complexity of manipulation operations, since there are no operation subsets. + +NOTE – The AOD23 MHS/Manipulation profile is not stable enough at the time of publication of this Recommendation; therefore, the AOD23 profile has not been considered. + +### **8.7.3 Use for document communication** + +MHS is used for message distribution in communication environments with multi-addressing functionality. + +ODA documents can be distributed as OdaBodyParts using O/R addresses to identify source and destination(s). The type of the body part shall be "oda [12] IMPLICIT OCTET STRING". Sending ODA documents in this way does not require any special use of MHS, except controlling the maximum allowed size of messages. This procedure shall be used in the storing and distribution basic services. + +Because of its non-deterministic behaviour (in relation with the time needed to distribute a message), MHS is less suited for interactive applications. But in some applications, if the reading or updating of the documents is not really interactive, the MHS communication module is used for the remote store management or remote interactive manipulation of documents. In this case, MHS interactive applications are to be seen as delayed interactive applications. + +When an interactive operation is requested, it shall be encoded as a DFR or DTAM-DM abstract operation with the appropriate arguments, as specified in the DFR standards or DTAM-DM Recommendations. The encoded abstract operation will be sent in MHS messages, and results will be received afterwards in new MHS messages. The type of the body part shall be "externally-defined [15] ExternallyDefinedBodyPart". + +This solution shall be used in the retrieval, storing-and-retrieval and manipulation basic services when there is a requirement to use store-and-forward communication. + +NOTE – This solution is an interim one before relevant profiles are developed. An example of this kind of profiles is AOD23. Once AOD23 is developed, the rules specified in that profile should substitute the rules given here. + +The number of BS shall be identified by bilateral agreements or by use of the Directory. + +When MHS is used, the profiles AMH11, AMH12, AMH13, AMH21, AMH22, AMH23 and AMH24 shall be used depending on the available protocols. + +## **8.8 Multipoint Communication Service (MCS)** + +### **8.8.1 Description** + +MCS specifies service and protocol for AGC (Audiographic Conference) to support multipoint communication using MCU (Multipoint Control Unit). MCS has communication services for: + +- multipoint data transfer; +- channel management; +- domain (or group) management; +- token management. + +### **8.8.2 Services and profile** + +The MCS service and protocol are defined and specified in Recommendations T.122 and T.125 respectively. + +No profile for MCS is defined. + +### **8.8.3 Use for document communication** + +The MCS communication module is used to provide the multicast function to other interactive document communication modules such as DTAM-DM module. In other words, multipoint document communication is realized by interactive document communication modules on top of MCS multipoint communication platform. + +# **9 Components and design rules for basic services** + +This clause provides a common base for the formal definition of basic services. It provides the rules to make such a formal definition. + +Basic services perform operations on service objects by using communication modules. Service objects are document stores, documents, document fragments, communicating entities and communication links. Some objects are more related to document aspects, others are related to communication aspects. + +Services are specified in terms of attributes, which describe their features. Attributes take values from a well-defined set of attribute values. + +Two service attribute sets are defined: + +- document related service attributes; +- communication related service attributes. + +For each attribute set, all attributes and their values are described. Throughout the text of this Recommendation, the names of service attributes are embedded in quotation marks, i.e. "attribute-name", and the values of service attributes are embedded in apostrophes, i.e. 'attribute-value'. + +If the attribute "example-attribute" takes the value 'example-value', the following notation is used: + +"example-attribute" = 'example-value' + +Subclause 9.3 defines the way in which the attribute values are assigned to the document and communication related attributes for the specification of basic services. + +Rules for the selection and restriction of the communication modules, which shall be used by the basic services, are also specified. + +Finally, application rules are provided, which may include further dynamic constraints on operations of the selected and restricted communication module when applying the basic services in communication applications. They are introduced in 9.3. + +## **9.1 Definition of document related service attributes** + +This subclause defines the document related service attribute set. + +The document related service attributes are: + +- "document location"; +- "document copies"; +- "document access rights"; +- "store access rights"; +- "document format"; +- "functionality level". + +The following subclauses describe the meaning of these document related service attributes, their values and the meaning of those values. + +### **9.1.1 The service attribute "document location"** + +This service attribute determines where the information, which is subject for the communication application, is located. + +The service attribute "document location" may take one of the following values: + +- 'local'; +- 'remote'. + +If access to the information is possible without using a communication link, the attribute has the value 'local'. + +If access to the information is only possible using a communication link, the attribute has the value 'remote'. + +### **9.1.2 The service attribute "document copies"** + +This service attribute indicates how many identical instances of the information, which is subject for the communication application, do exist. + +The service attribute "document copies" may take one of the following values: + +- 'one'; +- 'several'. + +The document or the document fragment can exist only as 1 instance, called original. In this case the service attribute has the value 'one'. If there exist the original and some copies, located somewhere, the service attribute has the value 'several'. + +### 9.1.3 The service attribute "document access rights" + +This service attribute determines the rights which are given to the user to access document fragments. + +The service attribute "document access rights" may take one or more of the following values: + +- 'no-access'; +- 'read-only'; +- 'extended-read'; +- 'add-only'; +- 'delete-only'; +- 'modify'; +- 'full-access'. + +Unauthorized users have no access right to the document, and therefore, no possibility to access any document fragment inside the document. In this case, the attribute has the value 'no-access'. + +Other users are allowed to read document fragments, but not to add, delete or modify document fragments inside the document. In this case, the attribute has the value 'read-only'. + +If "document access rights" = 'extended-read', the user can read document fragments. If hidden information is contained inside the document, the user will be informed about this fact, but the hidden information is not accessible to him. If the value 'extended-read' is not given, the user will not recognize this fact. + +The attribute value 'add-only' allows adding but not reading, deleting or modifying document fragments. + +The attribute value 'delete-only' allows for deleting document fragments. + +'Modify' means changing the values of existing document fragment attributes, without adding or deleting attributes. + +The 'full-access' right includes all other access rights except 'no-access'. + +Document access rights may be cumulated, for example, the attribute "document access rights" may take the values 'read-only' and 'modify'. + +### 9.1.4 The service attribute "store access rights" + +This service attribute determines the rights which are given to the user to access the document store. + +The service attribute "store access rights" may take one or more of the following values: + +- 'no-access'; +- 'read-only'; +- 'extended-read'; +- 'add-only'; +- 'delete-only'; +- 'modify'; +- 'full-access'. + +Unauthorized users have no access right to the document store, and therefore, no possibility to access any document inside the document store. In this case, the attribute has the value 'no-access'. + +Other users are allowed to read documents, but not to add, delete or modify documents inside the document store. In this case, the attribute has the value 'read-only'. + +If "store access rights" = 'extended-read', the user can read documents. If hidden information is contained inside the document store, the user will be informed about this fact, but the hidden information is not accessible to him. If the value 'extended-read' is not given, the user will not recognize this fact. + +The attribute value 'add-only' allows adding but not reading, deleting or modifying documents in the document store. + +The attribute value 'delete-only' allows for deleting documents from the document store. + +'Modify' means changing the values of existing attributes of documents, without adding or deleting documents. + +The 'full-access' right includes all other access rights except 'no-access'. + +Store access rights may be cumulated, for example, the attribute "store access rights" may take the values 'read-only' and 'add-only'. + +These store access rights have an equivalent meaning for documents in document stores as the document access rights have for document fragments in documents, but store access rights supersede document access rights. For example, if "store access rights" = 'add-only' and "document access rights" = 'delete-only', a communicating entity is not allowed to delete document fragments of any document. + +### **9.1.5 The service attribute "document format"** + +This service attribute determines the structure of the document which is subject of the communication application. + +The service attribute "document format" may take one of the following values: + +- 'FOD011'; +- 'FOD026'; +- 'FOD036'. + +The service attribute "document format" has the value 'FOD011' if the document conforms to the FOD011 DAP, which supports simple document structures; it takes the value 'FOD026' if the document conforms to the FOD026 DAP, which supports enhanced document structures and the value 'FOD036' is assigned if the document conforms to the FOD036 DAP, which provides for extended document structures. Clause 7 of this Recommendation gives further information about DAPs and their use in this Recommendation. + +### **9.1.6 The service attribute "functionality level"** + +A service may deal with service objects like document stores, documents or document fragments, on which operations may be performed. The service attribute "functionality level" determines a set of service objects and operations. + +The service attribute "functionality level" may take one of the following values: + +- 'T'; +- 'D'; +- 'F'; +- 'F-SF'; +- 'DS-F-SF'; +- 'DM-F-SF'; +- 'D-F-SF'. + +The meaning of these attribute values is: + +- 'I' (Independent): There are no service objects; the operations are those provided by the selected communication module and do not depend on the document store, documents or document fragments. +- 'D' (Documents): The service objects are one or more documents; the operations on these objects are those provided by the selected communication module. +- 'F' (document Fragment): The service object is one document fragment; the operations on this object are those provided by the selected communication module. +- 'F-SF' (document Fragment, Set of document Fragments): The service objects are one or more document fragments; the operations on these objects are those provided by the selected communication module. +- 'DS-F-SF' (Document Selection, document Fragment, Set of document Fragments): The service objects are one or more document fragments; the operations on these objects, and the operations for selection and reservation of the document which contains these objects, are those provided by the selected communication module. +- 'DM-F-SF' (Document Management, document Fragment, Set of document Fragments): The service objects are one or more document fragments; the operations on these objects, and the operations of managing the document which contains these objects, are those provided by the selected communication module. +- 'D-F-SF' (Documents, document Fragment, Set of document Fragments): The service objects are the document store, one or more documents and one or more document fragments; the operations on these objects are those provided by the selected communication module. + +The operations on service objects provided by the selected communication module may be restricted by rules given in the “Application rules” subclauses of the formal definitions of document communication basic services in clause 10. + +## **9.2 Definition of communication related service attributes** + +This subclause defines the communication related service attribute set. + +The communication related service attributes are: + +- "number of communicating entities"; +- "communication type"; +- "communication modules". + +The following subclauses describe the meaning of these communication related service attributes, their values and the meaning of those values. + +### **9.2.1 The service attribute "number of communicating entities"** + +This service attribute gives the number of communicating entities, in a communication application, on both sides of the communication link. + +The service attribute "number of communicating entities" may take one of the following values: + +- 'one-to-one'; +- 'one-to-several'. + +In a communication application, at least two communicating entities are involved, which are connected via a communication link. In this case, the service attribute takes the value 'one-to-one'; if one communicating entity is connected via several communication links to several remote communicating entities, it takes the value 'one-to-several'. + +### 9.2.2 The service attribute "communication type" + +This service attribute specifies the way in which the communication process is carried out. + +The service attribute "communication type" may take one of the following values: + +- 'end-to-end'; +- 'store-and-forward'. + +If the communication link between two communicating entities has been established and remains fixed during the communication phase, the value of "communication type" is 'end-to-end'. This means communication can take place on-line. A request from one communicating entity can be responded at once by the remote communicating entity. Therefore, interactive applications are possible. + +If the communication link between two communicating entities has not been established in a separate action before the communication phase, and may change during the communication phase, the value of "communication type" is 'store-and-forward'. In this case, interactive applications are to be seen as delayed interactive applications because of the non-deterministic time constraints between request and response of an operation. + +### 9.2.3 The service attribute "communication module" + +This service attribute specifies the communication module which is used by the service to carry out the communication process. + +The service attribute "communication module" may take one of the following values: + +- 'DFR'; +- 'DTAM-BT-NM'; +- 'DTAM-DM'; +- 'DTAM-TK'; +- 'DFR/DTAM-DM'; +- 'MHS'. + +In the case of "communication module" = 'DFR', the communication module DFR shall be used. In the case of "communication module" = 'DTAM-BT-NM', the communication module DTAM-BT-NM shall be used. In the case of "communication module" = 'DTAM-DM', the communication module DTAM-DM shall be used. In the case of "communication module" = 'DTAM-TK', the communication module DTAM-TK shall be used. In the case of "communication module" = 'DFR/DTAM-DM', the communication module DFR/DTAM-DM shall be used. In the case of "communication module" = 'MHS', the communication module MHS shall be used. + +Characteristics of these communication modules are summarized in clause 8. + +## 9.3 Rules for the formal definition of basic services + +For the formal definition of basic services, given in clause 10, four steps are followed: + +- assignment of values to the document related service attributes; +- assignment of values to the communication related service attributes; +- selection of the communication modules; +- specification of application rules. + +Rules and notation to follow these steps are given in the following subclauses. + +### 9.3.1 Rules and notation for the assignment of values to the document related service attributes + +The assignment of values to the document related service attributes is done using the notation depicted in Table 2 below: + +TABLE 2/T.190 + +**Values for document related service attributes for a basic service** + +| Service attribute | Attribute value(s) | Value description | +|--------------------------|-----------------------------------------------------------------------------------------------------------|-------------------| +| "document location" | 'local'
'remote' | | +| "document copies" | 'one'
'several' | | +| "document access rights" | 'no-access'
'read-only'
'extended-read'
'add-only'
'delete-only'
'modify'
'full-access' | | +| "store access rights" | 'no-access'
'read-only'
'extended-read'
'add-only'
'delete-only'
'modify'
'full-access' | | +| "document format" | 'FOD011'
'FOD026'
'FOD036' | | +| "functionality level" | 'I'
'D'
'F'
'F-SF'
'DS-F-SF'
'DM-F-SF'
'D-F-SF' | | + +In the "Service attribute" column, names of document related service attributes are given. + +In the 'Attribute value(s)' column, all possible values of all service attributes are given for reference. + +For each document related service attribute, tables in clause 10 (formal definition of basic services) provide, in the 'Attribute value(s)' column, either a unique value or a list of values. In the first case, the unique value is the one that the attribute shall take. In the second case, one and only one value shall be selected, as specified in the last column of the tables. This rule does not apply to the "document access rights" and "store access rights" service attributes, that may take more than one value (they are multi-valued attributes, as explained in 9.1.3 and 9.1.4), depending on the service. In this case, the attribute shall take all the values. + +For some basic services, attributes may be not applicable. In this case, 'N/A' is given in the 'Attribute value(s)' column of the tables. + +The "Value description" column is used, in tables in clause 10, to explain the choice of the values and the possible dependencies the chosen value may have on values of other service attributes. + +### 9.3.2 Rules and notation for the assignment of values to the communication related service attributes + +The assignment of values to the communication related service attributes is done using the notation depicted in Table 3 below: + +TABLE 3/T.190 + +**Values for communication related service attributes for a basic service** + +| Service attribute | Attribute value(s) | Value description | +|------------------------------------|---------------------------------------------------------------------------|-------------------| +| "number of communicating entities" | 'one-to-one'
'one-to-several' | | +| "communication type" | 'end-to-end'
'store-and-forward' | | +| "communication module" | 'DFR'
'DTAM-BT-NM'
'DTAM-DM'
'DTAM-TK'
'DFR/DTAM-DM'
'MHS' | | + +In the "Service attribute" column, names of communication related service attributes are given. + +In the 'Attribute value(s)' column, all possible values of all service attributes are given for reference. + +For each communication related service attribute, tables in clause 10 (formal definition of basic services) provide, in the 'Attribute value(s)' column, either a unique value or a list of values. In the first case, the unique value is the one that the attribute shall take. In the second case, one and only one value shall be selected, as specified in the last column of the tables. + +The "Value description" column is used, in tables in clause 10, to explain the choice of the values and the possible dependencies the chosen value may have on values of other service attributes. + +### 9.3.3 Rules and notation for the selection of the communication modules + +The selection of the communication modules and their possible restrictions (e.g. profiles) is done using the notation depicted in Table 4 below, using the selection mechanism described after the table. + +The selection mechanism consists of a sequence of the following steps, that are to be followed to select a communication module and its restrictions (e.g. profiles) from Table 4 above: + +- Step 1: Choice of one item of the column "functionality level"; this item selects a row of the table. +- Step 2: Choice of one value of the service attribute "communication type"; in the case of the value 'end-to-end', all columns of the table below this chosen value are selected; in the case of the value "store-and-forward", all columns of the table below this chosen value are selected. +- Step 3: Choice of one value of the service attribute "communication module"; this choice selects exactly one of the resulting columns of step 2, that is the communication module to be used for this service. +- Step 4: Choice of the table entry at the cross point of the selected row from step 1 and the selected column from step 3. +- Step 5: If the table entry is empty, the basic service cannot be performed with the chosen combination of "functionality level" and "communication module"; otherwise, the table entry contains the restrictions that shall be applied to the selected communication module. Further dynamic constraints on operations of the restricted communication module may be specified in the 'Application rules' subclause. + +TABLE 4/T.190 + +#### **Selection of communication modules for a basic service** + +| | | | | | | | +|------------------------|-------|--------------|-----------|-----------|---------------------|-------| +| "communication type" | | | | | | | +| 'end-to-end' | | | | | 'store-and-forward' | | +| "communication module" | | | | | | | +| "functionality level" | 'DFR' | 'DTAM-BT-NM' | 'DTAM-DM' | 'DTAM-TK' | 'DFR/DTAM-DM' | 'MHS' | +| 'T' | | | | | | | +| 'D' | | | | | | | +| 'F' | | | | | | | +| 'F-SF' | | | | | | | +| 'DS-F-SF' | | | | | | | +| 'DM-F-SF' | | | | | | | +| 'D-F-SF' | | | | | | | + +### **9.3.4 Application rules** + +Application rules specify further dynamic constraints on operations of the restricted communication module when applying a basic service in communication applications. + +The application rules may, in relation to the operations in the communication modules: + +- prohibit to perform some operations; +- allow some operations only under certain conditions; +- allow some operations only with specific arguments; +- prescribe a certain order of operations. + +# **10 Formal definition of document communication basic services** + +This clause defines all the basic services using the rules given in clause 9. + +## **10.1 Storing basic service** + +### **10.1.1 Document related service attributes** + +For each document related service attribute, Table 5 below provides attribute value(s) and value description, following the rules and notation specified in 9.3.1. + +### **10.1.2 Communication related service attributes** + +For each communication related service attribute, Table 6 below provides attribute value(s) and value description, following the rules and notation specified in 9.3.2. + +TABLE 5/T.190 + +#### **Values for document related service attributes for the storing basic service** + +| Service attribute | Attribute value(s) | Value description | +|--------------------------|----------------------------------|---------------------------------------------------------------------------------------------------------------------| +| "document location" | 'local' | The document(s) to be stored is (are) local to the communicating entity that sends the document(s). | +| "document copies" | 'one' | Only one copy of each document to be stored is necessary. | +| "document access rights" | N/A | Document fragment(s) shall not be accessed. | +| "store access rights" | 'add-only' | Storing basic service performs add-only operations in the remote store. | +| "document format" | 'FOD011'
'FOD026'
'FOD036' | This service attribute shall take only one of the possible values, depending on the desired document format. | +| "functionality level" | 'D' | The storing basic service provides for the storing of full document(s). Document fragment(s) shall not be accessed. | + +TABLE 6/T.190 + +#### **Values for communication related service attributes for the storing basic service** + +| Service attribute | Attribute value(s) | Value description | +|------------------------------------|-------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| "number of communicating entities" | 'one-to-one' | One communicating entity sends the document(s) to the other remote communicating entity. | +| "communication type" | 'end-to-end'
'store-and-forward' | The storing basic service can be accomplished either using end-to-end communication, where both communicating entities (client and server) are directly connected to perform the service, or using store-and-forward communication. Appendix II gives some rules to select a value for this service attribute. | +| "communication module" | 'DFR'
'DTAM-BT-NM'
'MHS' | The selection of the communication module is restricted by the values of the "functionality level" and "communication type" attributes, as specified in 10.1.3. | + +### 10.1.3 Selection of communication modules + +The selection of communication modules depends on the values of the attributes "functionality level" and "communication type". For the storing basic service, there is only one possible value for the "functionality level" service attribute. The communication module restrictions specified in Table 7 shall be used. + +Table 7 indicates the communication module restrictions to use. When DFR is used, a profile is provided; in other cases, the only restrictions to the communication module are those provided in the application rules (see 10.1.4). + +When "communication type" = 'end-to-end' is selected, two values of the service attribute "communication module" are possible, then Appendix II gives some rules to select a value for this service attribute. + +The communication module profile presented in Table 7 is defined in clause 8. + +TABLE 7/T.190 + +**Selection of communication modules for the storing basic service** + +| "communication type" | | | | | | | +|------------------------|-------|--------------|-----------|-----------|---------------------|--------------| +| 'end-to-end' | | | | | 'store-and-forward' | | +| "communication module" | | | | | | | +| "functionality level" | 'DFR' | 'DTAM-BT-NM' | 'DTAM-DM' | 'DTAM-TK' | 'DFR/DTAM-DM' | 'MHS' | +| 'I' | | | | | | | +| 'D' | ADF12 | See 10.1.4.2 | | | | See 10.1.4.3 | +| 'F' | | | | | | | +| 'F-SF' | | | | | | | +| 'DS-F-SF' | | | | | | | +| 'DM-F-SF' | | | | | | | +| 'D-F-SF' | | | | | | | + +The storing basic service can also be implemented using other communication modules which are given in Appendix I. + +### 10.1.4 Application rules + +The storing basic service may be used as a stand-alone service or to build complex document communication services. In the latter case, how to use the storing basic service is specified in the corresponding complex service specification (in other ITU-T Recommendations). + +This subclause specifies the rules the storing basic service shall follow when using communication modules. + +#### 10.1.4.1 Application rules when using DFR + +DFR, restricted to the ADF12 profile, is used. + +When the service is requested, the following steps shall be followed: + +- Step 1: A DFR association shall be established with DFR-Bind, identifying BS 1. +- Step 2: The DFR Create operation shall be issued, as many times as necessary, in order to add the document(s) to the remote communicating entity. +- Step 3: The DFR association shall be released with DFR-Unbind. + +#### 10.1.4.2 Application rules when using DTAM-BT-NM + +DTAM-BT-NM is used to transfer ODA documents following the rules given in 8.3. No specific application rules are given here. + +#### 10.1.4.3 Application rules when using MHS + +When the service is requested, the following step shall be followed: + +- Step 1: One MHS message containing the document or documents to store shall be sent, following the rules given in 8.7.3 concerning the distribution of ODA documents. BS 1 shall be identified. + +Step 1 can be repeated. + +## 10.2 Distribution basic service + +This subclause defines the distribution basic service using the rules given in clause 9. + +### 10.2.1 Document related service attributes + +For each document related service attribute, Table 8 provides attribute value(s) and value description, following the rules and notation specified in 9.3.1. + +TABLE 8/T.190 + +Values for document related service attributes for the distribution basic service + +| Service attribute | Attribute value(s) | Value description | +|--------------------------|----------------------------------|-------------------------------------------------------------------------------------------------------------------------------| +| "document location" | 'local' | The document(s) to be stored is (are) local to the communicating entity that distributes the document(s). | +| "document copies" | 'one' | Only one copy of each document to be distributed is necessary. | +| "document access rights" | N/A | Document fragment(s) shall not be accessed. | +| "store access rights" | 'add-only' | Distribution basic service performs add-only operations in the remote stores. | +| "document format" | 'FOD011'
'FOD026'
'FOD036' | This service attribute shall take only one of the possible values, depending on the desired document format. | +| "functionality level" | 'D' | The distribution basic service provides for the distribution of full document(s). Document fragment(s) shall not be accessed. | + +### 10.2.2 Communication related service attributes + +For each communication related service attribute, Table 9 provides attribute value(s) and value description, following the rules and notation specified in 9.3.2. + +TABLE 9/T.190 + +#### Values for communication related service attributes for the distribution basic service + +| Service attribute | Attribute value(s) | Value description | +|------------------------------------|-------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| "number of communicating entities" | 'one-to-several' | One communicating entity distributes the document(s) to n remote communicating entities (remote stores). | +| "communication type" | 'end-to-end'
'store-and-forward' | The distribution basic service can be accomplished either using end-to-end communication where the communicating entity that distributes the document(s) establishes a direct connection with the n remote communicating entities, or using store-and-forward communication. Appendix II gives some rules to select a value for this service attribute. | +| "communication module" | 'DFR'
'DTAM-BT-NM'
'MHS' | The selection of the communication module is restricted by the values of the "functionality level" and "communication type" attributes, as specified in 10.2.3. The distribution basic service is accomplished using only one communication module, therefore, this service attribute shall take only one of the given values. A distribution service using several different communication modules can be seen as a complex service based on the distribution basic service defined here. | + +### 10.2.3 Selection of communication modules + +The selection of communication modules depends on the values of the attributes "functionality level" and "communication type". For the distribution basic service, there is only one possible value for the "functionality level" service attribute. The communication module restrictions specified in Table 10 shall be used. + +Table 10 indicates the communication module restrictions to use. When DFR is used, a profile is provided; in other cases, the only restrictions to the communication module are those provided in the application rules (see 10.2.4). + +When "communication type" = 'end-to-end' is selected, two values of the service attribute "communication module" are possible, then Appendix II gives some rules to select a value for this service attribute. + +The communication module profile presented in Table 10 is defined in clause 8. + +The distribution basic service can also be implemented using other communication modules which are given in Appendix I. + +TABLE 10/T.190 + +#### **Selection of communication modules for the distribution basic service** + +| | | | | | | | +|------------------------|-------|--------------|-----------|-----------|---------------------|--------------| +| "communication type" | | | | | | | +| 'end-to-end' | | | | | 'store-and-forward' | | +| "communication module" | | | | | | | +| "functionality level" | 'DFR' | 'DTAM-BT-NM' | 'DTAM-DM' | 'DTAM-TK' | 'DFR/DTAM-DM' | 'MHS' | +| 'I' | | | | | | | +| 'D' | ADF12 | See 10.2.4.2 | | | | See 10.2.4.3 | +| 'F' | | | | | | | +| 'F-SF' | | | | | | | +| 'DS-F-SF' | | | | | | | +| 'DM-F-SF' | | | | | | | +| 'D-F-SF' | | | | | | | + +### **10.2.4 Application rules** + +The distribution basic service may be used as a stand-alone service or to build complex document communication services. In the latter case, how to use the distribution basic service is specified in the corresponding complex service specification (in other ITU-T Recommendations). + +This subclause specifies the rules the distribution basic service shall follow when using communication modules. + +#### **10.2.4.1 Application rules when using DFR** + +DFR, restricted to the ADF12 profile, is used. + +When the service is requested, with each of the $n$ remote communication entities to receive documents, the following steps shall be followed: + +- Step 1: A DFR association shall be established with DFR-Bind, identifying BS 2. +- Step 2: The DFR Create operation shall be issued, as many times as necessary, in order to add the document(s) to the remote communicating entity. +- Step 3: The DFR association shall be released with DFR-Unbind. + +#### **10.2.4.2 Application rules when using DTAM-BT-NM** + +DTAM-BT-NM is used to transfer ODA documents following the rules given in 8.3. No specific application rules are given here. + +If $n$ is the number of remote communicating entities to receive documents, then $n$ DTAM associations are established, one with each of the remote communicating entities (recipients). + +#### 10.2.4.3 Application rules when using MHS + +When the service is requested, the following step shall be followed: + +- Step 1: One MHS message, containing the document or documents to store, shall be sent to the n recipients, following the rules given in 8.7.3 concerning the distribution of ODA documents and the multi-addressing capabilities offered by MHS. BS 2 shall be identified. + +Step 1 can be repeated. + +## 10.3 Retrieval basic service + +This subclause defines the retrieval basic service using the rules given in clause 9. + +### 10.3.1 Document related service attributes + +For each document related service attribute, Table 11 provides attribute value(s) and value description, following the rules and notation specified in 9.3.1. + +TABLE 11/T.190 + +**Values for document related service attributes for the retrieval basic service** + +| Service attribute | Attribute value(s) | Value description | +|--------------------------|----------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| "document location" | 'remote' | The communicating entity that retrieves the document(s) or document fragment(s) is in a location remote to the document(s). If not, retrieval is a local matter. | +| "document copies" | 'one' | When documents or document fragments are retrieved, they are copied to the client communicating entity. From a global point of view, there is always only one copy of the documents: that of the remote store. | +| "document access rights" | 'read-only' | Retrieval basic service performs document or document fragment read-only operations. | +| "store access rights" | 'read-only' | Retrieval basic service performs read-only operations from the remote store. | +| "document format" | 'FOD011'
'FOD026'
'FOD036' | This attribute shall take only one of the possible values, depending on the document format desired.

The selection of a value for this attribute depends on the selected value for the "functionality level" attribute. In particular, FOD011 shall never be chosen if "functionality level" is different to 'D'. | +| "functionality level" | 'D'
'F-SF'
'DS-F-SF'
'D-F-SF' | This service attribute shall take only one of the possible values, depending on the functionality level desired. | + +### 10.3.2 Communication related service attributes + +For each communication related service attribute, Table 12 provides attribute value(s) and value description, following the rules and notation specified in 9.3.2. + +TABLE 12/T.190 + +#### **Values for communication related service attributes for the retrieval basic service** + +| Service attribute | Attribute value(s) | Value description | +|------------------------------------|----------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| "number of communicating entities" | 'one-to-one' | One communicating entity (client) makes the retrieval from the other communicating entity (server, remote store). Complex services may extend this basic service with more clients on the same store. | +| "communication type" | 'end-to-end'
'store-and-forward' | End-to-end communication, where both communicating entities (client and server) are directly connected to perform the service, is the natural selection for the retrieval basic service. However, store-and-forward communication can also be used. Appendix II gives some rules to select a value for this service attribute. | +| "communication module" | 'DFR'
'DTAM-DM'
'DTAM-DM/DFR'
'MHS' | The selection of the communication module is restricted by the values of the "functionality level" and "communication type" attributes, as specified in 10.3.3. | + +### **10.3.3 Selection of communication modules** + +Depending on the chosen values of the attributes "functionality level" and "communication type", the communication module restrictions specified in Table 13 shall be used. + +For "communication type" = 'end-to-end', three different communication modules are possible depending on the chosen value of the "functionality level" attribute. Table 13 indicates the communication module restrictions to use. + +For a given combination of values of "communication type" and "functionality level", only one specific value of the attribute "communication module" is allowed, as specified in Table 13. + +The communication module profiles presented in Table 13 are defined in clause 8. The DFR Reserve operation of ADF21 profile shall not be used. + +### **10.3.4 Application rules** + +The retrieval basic service may be used as a stand-alone service or to build complex document communication services. In the latter case, how to use the retrieval basic service is specified in the corresponding complex service specification (in other ITU-T Recommendations). + +This subclause specifies the rules the retrieval basic service shall follow when using communication modules. + +#### **10.3.4.1 Application rules when using DFR** + +In this case, the retrieval basic service is only applicable to full documents. DFR, restricted to the ADF11 profile, is used. + +TABLE 13/T.190 + +#### **Selection of communication modules for the retrieval basic service** + +| "communication type" | | | | | | | +|------------------------|-------|--------------|-----------|-----------|---------------------|--------------| +| 'end-to-end' | | | | | 'store-and-forward' | | +| "communication module" | | | | | | | +| "functionality level" | 'DFR' | 'DTAM-BT-NM' | 'DTAM-DM' | 'DTAM-TK' | 'DFR/DTAM-DM' | 'MHS' | +| 'T' | | | | | | | +| 'D' | ADF11 | | | | | See 10.3.4.4 | +| 'F' | | | | | | | +| 'F-SF' | | | AOD11 | | | See 10.3.4.4 | +| 'DS-F-SF' | | | | | ADF21+
AOD11 | See 10.3.4.4 | +| 'DM-F-SF' | | | | | | | +| 'D-F-SF' | | | | | ADF11+
AOD11 | See 10.3.4.4 | + +When the service is requested, the following steps shall be followed: + +- Step 1: A DFR association shall be established with DFR-Bind, identifying BS 3. +- Step 2: The operations provided in the ADF11 profile can be issued, in order to perform the required retrieval operations. +- Step 3: The DFR association shall be released with DFR-Unbind. + +#### **10.3.4.2 Application rules when using DTAM-DM** + +In this case, the retrieval basic service is only applicable to document fragments. DTAM-DM, restricted to the AOD11 profile, is used. + +When the service is requested, the following steps shall be followed: + +- Step 1: A DTAM-DM association shall be established with DTAM-DM-Bind, identifying BS 3. +- Step 2: One or more documents shall be open with DM-DOCUMENT-OPEN. +- Step 3: The operations provided in the AOD11 profile can be issued, in order to perform the required retrieval operations. +- Step 4: The open documents shall be closed with DM-DOCUMENT-CLOSE. +- Step 5: The DTAM-DM association shall be released with DTAM-DM-Unbind. + +The sequence of steps 2, 3 and 4 can be repeated. + +#### **10.3.4.3 Application rules when using DFR in combination with DTAM-DM** + +In this case, the retrieval basic service is applicable to both documents and document fragments. DFR combined with DTAM-DM is used and restricted. + +There are two possible cases depending on the value of the "functionality level" attribute: + +##### a) *"functionality level" = 'DS-F-SF'* + +In this case, the functionality of the operations on full documents is limited to the possibility of selecting a document. The ADF21 and AOD11 profiles shall be used. + +When the service is requested, the following steps shall be followed: + +- Step 1: A DTAM-DM association shall be established with DTAM-DM-Bind, identifying BS 3. +- Step 2: Optionally, one or more documents shall be selected with ADF21 operations. +- Step 3: One or more documents shall be open with DM-DOCUMENT-OPEN. +- Step 4: The operations provided in the AOD11 profile can be issued, in order to perform the required retrieval operations on document fragments. +- Step 5: The open documents shall be closed with DM-DOCUMENT-CLOSE. +- Step 6: The DTAM-DM association shall be released with DTAM-DM-Unbind. + +The sequence of steps 2, 3, 4 and 5, and the sequence of steps 3, 4 and 5 can be repeated. + +##### b) *"functionality level" = 'D-F-SF'* + +In this case, the ADF11 and AOD11 profiles shall be used. + +When the service is requested, the following steps shall be followed: + +- Step 1: A DTAM-DM association shall be established with DTAM-DM-Bind, identifying BS 3. +- Step 2: The operations provided in the ADF11 profile can be issued, in order to perform the required retrieval operations. +- Step 3: Optionally, one or more documents shall be open with DM-DOCUMENT-OPEN. +- Step 4: If step 3 has been performed, the operations provided in the AOD11 profile can be issued, in order to perform the required retrieval operations on document fragments. +- Step 5: If step 4 has been performed, the open documents shall be closed with DM-DOCUMENT-CLOSE. +- Step 6: The DTAM-DM association shall be released with DTAM-DM-Unbind. + +The sequence of steps 2, 3, 4 and 5, and the sequence of steps 3, 4 and 5 can be repeated. + +#### **10.3.4.4 Application rules when using MHS** + +In this case, the retrieval basic service is applicable to full documents only, to document fragments only, and to documents and document fragments. + +When the service is requested, the following steps shall be followed: + +- Step 1: The required retrieval operations are sent in one or more MHS messages, following the rules given in 8.7.3; BS 3 shall be identified. +- Step 2: Optionally, results are returned in new MHS messages, following the rules given in 8.7.3. + +Steps 1 and 2 can be repeated. + +## **10.4 Storing-and-Retrieval basic service** + +This subclause defines the storing-and-retrieval basic service using the rules given in clause 9. + +### **10.4.1 Document related service attributes** + +For each document related service attribute, Table 14 provides attribute value(s) and value description, following the rules and notation specified in 9.3.1. + +### **10.4.2 Communication related service attributes** + +For each communication related service attribute, Table 15 provides attribute value(s) and value description, following the rules and notation specified in 9.3.2. + +TABLE 14/T.190 + +#### **Values for document related service attributes for the storing-and-retrieval basic service** + +| Service attribute | Attribute value(s) | Value description | +|--------------------------|----------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| "document location" | 'remote' | The user is in a location remote to the document(s). If not, storing-and-retrieval of document(s) or document fragment(s) is a local matter. | +| "document copies" | 'one' | When documents or document fragments are retrieved, they are copied to the client communicating entity, while when documents or document fragments are stored, they are copied to the remote store. From a global point of view, there is always only one copy of the documents: that of the remote server. | +| "document access rights" | 'read-only'
'add-only' | Retrieval operations are document (or document fragment) read-only operations, while storing operations are document (or document fragment) add-only operations. | +| "store access rights" | 'read-only'
'add-only' | Retrieval operations are read-only operations in the remote store, while storing operations are add-only operations. | +| "document format" | 'FOD011'
'FOD026'
'FOD036' | This service attribute shall take only one of the possible values, depending on the desired document format.

The selection of a value for this attribute depends on the selected value for the "functionality level" attribute. In particular, FOD011 shall never be chosen if "functionality level" is different to 'D'. | +| "functionality level" | 'D'
'F-SF'
'DS-F-SF'
'D-F-SF' | This service attribute shall take only one of the possible values, depending on the functionality level desired. | + +### **10.4.3 Selection of communication modules** + +Depending on the chosen values of the attributes "functionality level" and "communication type", the communication module restrictions (profiles in this case) specified in Table 16 shall be used. + +For "communication type" = 'end-to-end', three different communication modules are possible depending on the chosen value of the "functionality level" attribute. Table 16 indicates the communication profile to use. For a given combination of values of "communication type" and "functionality level", only one specific value of the attribute "communication modules" is allowed, as specified in Table 16. + +The communication module profiles presented in Table 16 are defined in clause 8. The DFR Reserve operation of ADF21 profile shall not be used. + +TABLE 15/T.190 + +#### **Values for communication related service attributes for the storing-and-retrieval basic service** + +| Service attribute | Attribute value(s) | Value description | +|------------------------------------|----------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| "number of communicating entities" | 'one-to-one' | One communicating entity (client) makes the storing/retrieval to/from another communicating entity (server). | +| "communication type" | 'end-to-end'
'store-and-forward' | End-to-end communication, where both communicating entities (client and server) are directly connected to perform the service, is the natural selection for the storing-and-retrieval basic service. However, store-and-forward communication can also be used. Appendix II gives some rules to select a value for this service attribute. | +| "communication module" | 'DFR'
'DTAM-DM'
'DFR/DTAM-DM'
'MHS' | The selection of the communication module is restricted by the chosen values of the "functionality level" and "communication type" attributes, as specified in 10.4.3. | + +TABLE 16/T.190 + +#### **Selection of communication modules for the storing-and-retrieval basic service** + +| | | | | | | | +|------------------------|-------|--------------|-----------|-----------|---------------------|--------------| +| "communication type" | | | | | | | +| 'end-to-end' | | | | | 'store-and-forward' | | +| "communication module" | | | | | | | +| "functionality level" | 'DFR' | 'DTAM-BT-NM' | 'DTAM-DM' | 'DTAM-TK' | 'DFR/DTAM-DM' | 'MHS' | +| 'T' | | | | | | | +| 'D' | ADF12 | | | | | See 10.4.4.4 | +| 'F' | | | | | | | +| 'F-SF' | | | AOD12 | | | See 10.4.4.4 | +| 'DS-F-SF' | | | | | ADF21+
AOD12 | See 10.4.4.4 | +| 'DM-F-SF' | | | | | | | +| 'D-F-SF' | | | | | ADF12+
AOD12 | See 10.4.4.4 | + +### 10.4.4 Application rules + +The storing-and-retrieval basic service may be used as a stand-alone service or to build complex document communication services. In the latter case, how to use the storing-and-retrieval basic service is specified in the corresponding complex service specification (in other ITU-T Recommendations). + +This subclause specifies the rules the storing-and-retrieval basic service shall follow when using communication modules. + +#### 10.4.4.1 Application rules when using DFR + +In this case, the storing-and-retrieval basic service is only applicable to full documents. DFR, restricted to the ADF12 profile, is used. + +When the service is requested, the following steps shall be followed: + +- Step 1: A DFR association shall be established with DFR-Bind, identifying BS 4. +- Step 2: The operations provided in the ADF12 profile can be issued, in order to perform the required storing and retrieval operations. +- Step 3: The DFR association shall be released with DFR-Unbind. + +#### 10.4.4.2 Application rules when using DTAM-DM + +In this case, the storing-and-retrieval basic service is only applicable to document fragments. DTAM-DM, restricted to the AOD12 profile, is used. + +When the service is requested, the following steps shall be followed: + +- Step 1: A DTAM-DM association shall be established with DTAM-DM-Bind, identifying BS 4. +- Step 2: One or more documents shall be open with DM-DOCUMENT-OPEN. +- Step 3: The operations provided in the AOD12 profile can be issued, in order to perform the required storing and retrieval operations. +- Step 4: The open documents shall be closed with DM-DOCUMENT-CLOSE. +- Step 5: The DTAM-DM association shall be released with DTAM-DM-Unbind. + +The sequence of steps 2, 3 and 4 can be repeated. + +#### 10.4.4.3 Application rules when using DFR in combination with DTAM-DM + +In this case, the storing-and-retrieval basic service is applicable to both documents and document fragments. DFR combined with DTAM-DM is used and restricted. + +There are two possible cases depending on the value of the "functionality level" service attribute: + +- a) *"functionality level" = 'DS-F-SF'* + +In this case, the functionality of the operations on full documents is limited to the possibility of selecting a document. The ADF21 and AOD12 profiles shall be used. + +When the service is requested, the following steps shall be followed: + +- Step 1: A DTAM-DM association shall be established with DTAM-DM-Bind, identifying BS 4. +- Step 2: Optionally, one or more documents shall be selected with ADF21 operations. +- Step 3: One or more documents shall be open with DM-DOCUMENT-OPEN. +- Step 4: The operations provided in the AOD12 profile can be issued, in order to perform the required storing and retrieval operations on document fragments. +- Step 5: The open documents shall be closed with DM-DOCUMENT-CLOSE. +- Step 6: The DTAM-DM association shall be released with DTAM-DM-Unbind. + +The sequence of steps 2, 3, 4 and 5, and the sequence of steps 3, 4 and 5 can be repeated. + +b) *"functionality level" = 'D-F-SF'* + +In this case, the ADF12 and AOD12 profiles shall be used. + +When the service is requested, the following steps shall be followed: + +- Step 1: A DTAM-DM association shall be established with DTAM-DM-Bind, identifying BS 4. +- Step 2: The operations provided in the ADF12 profile can be issued, in order to perform the required storing and retrieval operations. +- Step 3: Optionally, one or more documents shall be open with DM-DOCUMENT-OPEN. +- Step 4: If step 3 has been performed, the operations provided in the AOD12 profile can be issued, in order to perform the required storing and retrieval operations on document fragments. +- Step 5: If step 4 has been performed, the open documents shall be closed with DM-DOCUMENT-CLOSE. +- Step 6: The DTAM-DM association shall be released with DTAM-DM-Unbind. + +The sequence of steps 2, 3, 4 and 5, and the sequence of steps 3, 4 and 5 can be repeated. + +#### **10.4.4.4 Application rules when using MHS** + +In this case, the storing-and-retrieval basic service is applicable to full documents only, to document fragments only, and to documents and document fragments. + +When the service is requested, the following steps shall be followed: + +- Step 1: The required storing and retrieval operations are sent in one or more MHS messages, following the rules given in 8.7.3; BS 4 shall be identified. +- Step 2: Optionally, results are returned in new MHS messages, following the rules given in 8.7.3. + +Steps 1 and 2 can be repeated. + +## **10.5 Manipulation basic service** + +This subclause defines the manipulation basic service using the rules given in clause 9. + +### **10.5.1 Document related service attributes** + +For each document related service attribute, Table 17 provides attribute value(s) and value description, following the rules and notation specified in 9.3.1. + +### **10.5.2 Communication related service attributes** + +For each communication related service attribute, Table 18 provides attribute value(s) and value description, following the rules and notation specified in 9.3.2. + +### **10.5.3 Relationship to communication modules** + +Depending on the chosen values of the attributes "functionality level" and "communication type", the communication module restrictions (profiles in this case) specified in Table 19 shall be used. + +For "communication type" = 'end-to-end', three different communication modules are possible depending on the chosen value of the "functionality level" attribute. Table 19 indicates the communication profile to use. For a given combination of values of "communication type" and "functionality level", only one specific value of the attribute "communication modules" is allowed, as specified in Table 19. + +The communication module profiles presented in Table 19 are defined in clause 8. + +TABLE 17/T.190 + +#### **Values for document related service attributes for the manipulation basic service** + +| Service attribute | Attribute value(s) | Value description | +|--------------------------|-----------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| "document location" | 'remote' | The user is in a location remote to the document(s). If not, manipulation is a local matter. | +| "document copies" | 'one' | The server communicating entity has the only copy of the document. The client communicating entity orders the manipulation operations, that are performed on the remote store. | +| "document access rights" | 'full access' | Manipulation requires full access rights to the document(s). | +| "store access rights" | 'full access' | Manipulation requires full access rights to the remote store. | +| "document format" | 'FOD011'
'FOD026'
'FOD036' | This attribute shall take only one of the possible values, depending on the document format desired.

The selection of a value for this attribute depends on the selected value for the "functionality level" attribute. In particular, FOD011 shall never be chosen if "functionality level" is different to 'D'. | +| "functionality level" | 'D'
'F-SF'
'DS-F-SF'
'DM-F-SF'
'D-F-SF' | This attribute shall take only one of the possible values, depending on the functionality level desired. | + +TABLE 18/T.190 + +#### **Values for communication related service attributes for the manipulation basic service** + +| Service attribute | Attribute value(s) | Value description | +|------------------------------------|----------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| "number of communicating entities" | 'one-to-one' | One client manipulates documents in the remote store (server). | +| "communication type" | 'end-to-end'
'store-and-forward' | End-to-end communication, where both communicating entities (client and server) are directly connected to perform the service, is the natural selection for the manipulation basic service. However, store-and-forward communication can also be used. Appendix II gives some rules to select a value for this service attribute. | +| "communication module" | 'DFR'
'DTAM-DM'
'DFR/DTAM-DM'
'MHS' | The selection of the communication modules is restricted by the chosen values of the "functionality level" and "communication type" attributes, as specified in 10.5.3. | + +TABLE 19/T.190 + +#### **Selection of communication modules for the manipulation basic service** + +| "communication type" | | | | | | | +|------------------------|-------|--------------|-----------|-----------|---------------------|--------------| +| 'end-to-end' | | | | | 'store-and-forward' | | +| "communication module" | | | | | | | +| "functionality level" | 'DFR' | 'DTAM-BT-NM' | 'DTAM-DM' | 'DTAM-TK' | 'DFR/DTAM-DM' | 'MHS' | +| 'T' | | | | | | | +| 'D' | ADF13 | | | | | See 10.5.4.4 | +| 'F' | | | | | | | +| 'F-SF' | | | AOD13 | | | See 10.5.4.4 | +| 'DS-F-SF' | | | | | ADF21+ AOD13 | See 10.5.4.4 | +| 'DM-F-SF' | | | | | ADF22 + AOD13 | See 10.5.4.4 | +| 'D-F-SF' | | | | | ADF13+ AOD13 | See 10.5.4.4 | + +### **10.5.4 Application rules** + +The manipulation basic service may be used as a stand-alone service or to build complex document communication services. In the latter case, how to use the manipulation basic service is specified in the corresponding complex service specification (in other ITU-T Recommendations). + +This subclause specifies the rules the manipulation basic service shall follow when using communication modules. + +#### **10.5.4.1 Application rules when using DFR** + +In this case, the manipulation basic service is only applicable to full documents. DFR, restricted to the ADF13 profile, is used. + +When the service is requested, the following steps shall be followed: + +- Step 1: A DFR association shall be established with DFR-Bind, identifying BS 5. +- Step 2: The operations provided in the ADF13 profile can be issued, in order to perform the required manipulation operations. +- Step 3: The DFR association shall be released with DFR-Unbind. + +#### **10.5.4.2 Application rules when using DTAM-DM** + +In this case, the manipulation basic service is only applicable to document fragments. DTAM-DM, restricted to the AOD13 profile, is used. + +When the service is requested, the following steps shall be followed: + +- Step 1: A DTAM-DM association shall be established with DTAM-DM-Bind, identifying BS 5. +- Step 2: One or more documents shall be open with DM-DOCUMENT-OPEN. +- Step 3: The operations provided in the AOD13 profile can be issued, in order to perform the required manipulation operations. +- Step 4: The open documents shall be closed with DM-DOCUMENT-CLOSE. +- Step 5: The DTAM-DM association shall be released with DTAM-DM-Unbind. + +The sequence of steps 2, 3 and 4 can be repeated. + +#### 10.5.4.3 Application rules when using DFR in combination with DTAM-DM + +In this case, the manipulation basic service is applicable to both documents and document fragments. DFR combined with DTAM-DM is used and restricted. + +There are three possible cases depending on the value of the "functionality level" attribute: + +##### a) *"functionality level" = 'DS-F-SF'* + +In this case, the functionality of the operations on full documents is limited to the possibility of selecting a document. The ADF21 and AOD13 profiles shall be used. + +When the service is requested, the following steps shall be followed: + +- Step 1: A DTAM-DM association shall be established with DTAM-DM-Bind, identifying BS 5. +- Step 2: Optionally, one or more documents shall be selected with ADF21 operations. +- Step 3: One or more documents shall be open with DM-DOCUMENT-OPEN. +- Step 4: The operations provided in the AOD13 profile can be issued, in order to perform the required manipulation operations on document fragments. +- Step 5: The open documents shall be closed with DM-DOCUMENT-CLOSE. +- Step 6: The DTAM-DM association shall be released with DTAM-DM-Unbind. + +The sequence of steps 2, 3, 4 and 5, and the sequence of steps 3, 4 and 5 can be repeated. + +##### b) *"functionality level" = 'DM-F-SF'* + +In this case, the functionality of the operations on full documents is limited to the possibility of selecting a document, and managing the document store. The ADF22 and AOD13 profiles shall be used. + +When the service is requested, the following steps shall be followed: + +- Step 1: A DTAM-DM association shall be established with DTAM-DM-Bind, identifying BS 5. +- Step 2: Optionally, one or more documents shall be selected and the document store shall be managed with ADF22 operations. +- Step 3: One or more documents shall be open with DM-DOCUMENT-OPEN. +- Step 4: The operations provided in the AOD13 profile can be issued, in order to perform the required manipulation operations on document fragments. +- Step 5: The open documents shall be closed with DM-DOCUMENT-CLOSE. +- Step 6: The DTAM-DM association shall be released with DTAM-DM-Unbind. + +The sequence of steps 2, 3, 4 and 5, and the sequence of steps 3, 4 and 5 can be repeated. + +##### c) *"functionality level" = 'D-F-SF'* + +In this case, the ADF13 and AOD13 profiles shall be used. + +When the service is requested, the following steps shall be followed: + +- Step 1: A DTAM-DM association shall be established with DTAM-DM-Bind, identifying BS 5. +- Step 2: The operations provided in the ADF13 profile can be issued, in order to perform the required manipulation operations. + +- Step 3: Optionally, one or more documents shall be open with DM-DOCUMENT-OPEN. +- Step 4: If step 3 has been performed, the operations provided in the AOD13 profile can be issued, in order to perform the required manipulation operations on document fragments. +- Step 5: If step 4 has been performed, the open documents shall be closed with DM-DOCUMENT-CLOSE. +- Step 6: The DTAM-DM association shall be released with DTAM-DM-Unbind. + +The sequence of steps 2, 3, 4 and 5, and the sequence of steps 3, 4 and 5 can be repeated. + +#### 10.5.4.4 Application rules when using MHS + +In this case, the manipulation basic service is applicable to full documents only, to document fragments only, and to documents and document fragments. + +When the service is requested, the following steps shall be followed: + +- Step 1: The required manipulation operations are sent in one or more MHS messages, following the rules given in 8.7.3; BS 5 shall be identified. +- Step 2: Optionally, results are returned in new MHS messages, following the rules given in 8.7.3. + +Steps 1 and 2 can be repeated. + +## 10.6 Pointing basic service + +This subclause defines the pointing basic service using the rules given in clause 9. + +### 10.6.1 Document related service attributes + +For each document related service attribute, Table 20 provides attribute value(s) and value description, following the rules and notation specified in 9.3.1. + +TABLE 20/T.190 + +**Values for document related service attributes for the pointing basic service** + +| Service attribute | Attribute value(s) | Value description | +|--------------------------|----------------------|--------------------------------------------------------------------------------------------------------------------------| +| "document location" | 'remote' | The user is in a location remote to the document. If not, pointing is a local matter. | +| "document copies" | 'one' | The server has the only copy of the document. The client orders the pointing operation, that is performed on the server. | +| "document access rights" | 'read-only' | Pointing is a document fragment read-only operation. | +| "store access rights" | N/A | There are no operations on the store. | +| "document format" | 'FOD026'
'FOD036' | This service attribute shall take only one of the possible values, depending on the desired document format. | +| "functionality level" | 'F' | Pointing is only possible on a document fragment. | + +### 10.6.2 Communication related service attributes + +For each communication related service attribute, Table 21 provides attribute value(s) and value description, following the rules and notation specified in 9.3.2. + +TABLE 21/T.190 + +#### **Values for communication related service attributes for the pointing basic service** + +| Service attribute | Attribute value(s) | Value description | +|------------------------------------|--------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------| +| "number of communicating entities" | 'one-to-one' | One client points to a document fragment inside a document in a remote server. | +| "communication type" | 'end-to-end' | Pointing is accomplished using end-to-end communication: Both communicating entities (client and server) are directly connected to perform the service. | +| "communication module" | 'DTAM-DM' | The selection of the communication module is restricted by the values of the "functionality level" and "communication type" attributes, as specified in 10.6.3. | + +### **10.6.3 Selection of communication modules** + +The selection of communication modules depends on the values of the attributes "functionality level" and "communication type". For the pointing service, there is only one possible value for each of them. The communication module restriction specified in Table 22 shall be used. + +Table 22 indicates the communication module restrictions to use. + +The communication module restriction is not specified as a profile, but as a "Manipulation Level Selection", as specified in DTAM-DM service, Recommendation T.435. The 'Basic Read Only Level' manipulation level selection shall be used including the DM-POINT operation, that is defined as optional in that manipulation level. + +### **10.6.4 Application rules** + +The pointing basic service shall be used to build complex document communication services. Details on how to use the pointing basic service when building complex services are specified in the corresponding complex service specification (in other ITU-T Recommendations). + +#### **10.6.4.1 Application rules when using DTAM-DM** + +This is the only possibility for the pointing basic service. DTAM-DM, restricted to the basic read only level, is used. + +When the service is requested, the following steps shall be followed: + +- Step 1: A DTAM-DM association shall be established with DTAM-DM-Bind, identifying BS 6. +- Step 2: The document where to point shall be opened with DM-DOCUMENT-OPEN. +- Step 3: The DM-POINT operation shall be used to point to a document fragment inside the open document. +- Step 4: The open documents shall be closed with DM-DOCUMENT-CLOSE. +- Step 5: The DTAM-DM association shall be released with DTAM-DM-Unbind. + +Step 3 and the sequence of steps 2, 3 and 4 can be repeated. + +## **10.7 Multi-pointing basic service** + +This subclause defines the multi-pointing basic service using the rules given in clause 9. + +TABLE 22/T.190 + +### **Selection of communication modules for the pointing basic service** + +| | | | | | | | +|------------------------|-------|--------------|-----------------------|-----------|---------------------|-------| +| "communication type" | | | | | | | +| 'end-to-end' | | | | | 'store-and-forward' | | +| "communication module" | | | | | | | +| "functionality level" | 'DFR' | 'DTAM-BT-NM' | 'DTAM-DM' | 'DTAM-TK' | 'DFR/DTAM-DM' | 'MHS' | +| 'T' | | | | | | | +| 'D' | | | | | | | +| 'F' | | | Basic Read Only Level | | | | +| 'F-SF' | | | | | | | +| 'DS-F-SF' | | | | | | | +| 'DM-F-SF' | | | | | | | +| 'D-F-SF' | | | | | | | + +### **10.7.1 Document related service attributes** + +For each document related service attribute, Table 23 provides attribute value(s) and value description, following the rules and notation specified in 9.3.1. + +### **10.7.2 Communication related service attributes** + +For each communication related service attribute, Table 24 provides attribute value(s) and value description, following the rules and notation specified in 9.3.2. + +### **10.7.3 Selection of communication modules** + +The selection of communication modules depends on the values of the attributes "functionality level" and "communication type". For the multi-pointing service, there is only one possible value for each of them. The communication module restriction specified in Table 25 shall be used. + +Table 25 indicates the communication module restrictions to use. + +The communication module restriction is not specified as a profile, but as a "Manipulation Level Selection", as specified in DTAM-DM service, Recommendation T.435. The 'Basic Read Only Level' manipulation level selection shall be used including the DM-POINT operation, that is defined as optional in that manipulation level. + +### **10.7.4 Application rules** + +The multi-pointing basic service shall be used to build complex document communication services. Details on how to use the multi-pointing basic service when building complex services are specified in the corresponding complex service specification (in other ITU-T Recommendations). + +TABLE 23/T.190 + +#### **Values for document related service attributes, for the multi-pointing basic service** + +| Service attribute | Attribute value(s) | Value description | +|--------------------------|----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| "document location" | 'remote' | The user is in a location remote to the document. If not, multi-pointing is a local matter. | +| "document copies" | 'several' | Every server in which a document fragment is pointed shall have either a copy of the full document or a document fragment in which all pointing operations will be performed. The client orders the multi-pointing operation, that is performed, as a single pointing, on every server. | +| "document access rights" | 'read-only' | Multi-pointing is a document fragment read-only operation. | +| "store access rights" | N/A | There are no operations on the store. | +| "document format" | 'FOD026'
'FOD036' | This service attribute shall take only one of the possible values, depending on the desired document format. | +| "functionality level" | 'F' | Multi-pointing is only possible on a document fragment. | + +TABLE 24/T.190 + +#### **Values for communication related service attributes for the multi-pointing basic service** + +| Service attribute | Attribute value(s) | Value description | +|------------------------------------|--------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------| +| "number of communicating entities" | 'one-to-several' | One communicating entity (client) points a document fragment to n remote communicating entities (servers). | +| "communication type" | 'end-to-end' | Multi-pointing is accomplished using end-to-end communication: Both communicating entities (client and server) are directly connected to perform the service. | +| "communication module" | 'DTAM-DM' | The selection of the communication module is restricted by the values of the "functionality level" and "communication type" attributes, as specified in 10.7.3. | + +TABLE 25/T.190 + +#### **Selection of communication modules for the multi-pointing basic service** + +| | | | | | | | +|------------------------|-------|--------------|-----------------------|-----------|---------------------|-------| +| "communication type" | | | | | | | +| 'end-to-end' | | | | | 'store-and-forward' | | +| "communication module" | | | | | | | +| "functionality level" | 'DFR' | 'DTAM-BT-NM' | 'DTAM-DM' | 'DTAM-TK' | 'DFR/DTAM-DM' | 'MHS' | +| 'I' | | | | | | | +| 'D' | | | | | | | +| 'F' | | | Basic Read Only Level | | | | +| 'F-SF' | | | | | | | +| 'DS-F-SF' | | | | | | | +| 'DM-F-SF' | | | | | | | +| 'D-F-SF' | | | | | | | + +#### **10.7.4.1 Application rules when using DTAM-DM** + +This is the only possibility for the multi-pointing basic service. DTAM-DM, restricted to the basic read only level, is used. + +When the service is requested, the following steps shall be followed (n is the number of communicating entities in which a document will be pointed to): + +- Step 1: n DTAM-DM associations shall be established with DTAM-DM-Bind, identifying BS 7. +- Step 2: The document where the point shall be opened with DM-DOCUMENT-OPEN in the n communicating entities with which the association is established. +- Step 3: The DM-POINT operation shall be used to point to a document fragment inside the open document (in the n communicating entities). +- Step 4: The open documents shall be closed with DM-DOCUMENT-CLOSE (in the n communicating entities). +- Step 5: The n DTAM-DM associations shall be released with DTAM-DM-Unbind. + +Step 3 and the sequence of steps 2, 3 and 4 can be repeated. + +## **10.8 Token-interchange basic service** + +This subclause defines the token-interchange basic service using the rules given in clause 9. + +### **10.8.1 Document related service attributes** + +For each document related service attribute, Table 26 provides attribute value(s) and value description, following the rules and notation specified in 9.3.1. + +TABLE 26/T.190 + +#### **Values for document related service attributes for the token-interchange basic service** + +| Service attribute | Attribute value(s) | Value description | +|--------------------------|--------------------|---------------------------------------------------------------------------------------------------------| +| "document location" | N/A | The token-interchange basic service is document independent. | +| "document copies" | N/A | The token-interchange basic service is document independent. | +| "document access rights" | N/A | The token-interchange basic service is document independent. | +| "store access rights" | N/A | The token-interchange basic service is document store independent. | +| "document format" | N/A | The token-interchange basic service is document independent. | +| "functionality level" | 'I' | The token-interchange basic service is independent of document store, documents and document fragments. | + +### **10.8.2 Communication related service attributes** + +For each communication related service attribute, Table 27 provides attribute value(s) and value description, following the rules and notation specified in 9.3.2. + +TABLE 27/T.190 + +#### **Values for communication related service attributes for the token-interchange basic service** + +| Service attribute | Attribute value(s) | Value description | +|------------------------------------|--------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------| +| "number of communicating entities" | 'one-to-one' | The token is exchanged between two communicating entities. | +| "communication type" | 'end-to-end' | Token-interchange is accomplished using end-to-end communication: Both communicating entities are directly connected to perform the service. | +| "communication modules" | 'DTAM-TK' | The selection of the communication module is restricted by the values of the "functionality level" and "communication type" attributes, as specified in 10.8.3. | + +### **10.8.3 Selection of communication modules** + +The selection of communication modules depends on the values of the attributes "functionality level" and "communication type". For the token-interchange basic service, there is only one possible value for each of them. The communication module restriction specified in Table 28 shall be used. + +Table 28 indicates the communication module restrictions to use. + +"Full service element" means that no restrictions are to be applied and that the full service element of the DTAM-TK communication module, comprising the TK-TOKEN-PLEASE and TK-TOKEN-GIVE operations, shall be used (see 8.5). + +TABLE 28/T.190 + +#### **Selection of communication modules for the token-interchange basic service** + +| "communication type" | | | | | | | +|------------------------|-------|--------------|-----------|----------------------|---------------------|-------| +| 'end-to-end' | | | | | 'store-and-forward' | | +| "communication module" | | | | | | | +| "functionality level" | 'DFR' | 'DTAM-BT-NM' | 'DTAM-DM' | 'DTAM-TK' | 'DFR/DTAM-DM' | 'MHS' | +| 'I' | | | | Full service element | | | +| 'D' | | | | | | | +| 'F' | | | | | | | +| 'F-SF' | | | | | | | +| 'DS-F-SF' | | | | | | | +| 'DM-F-SF' | | | | | | | +| 'D-F-SF' | | | | | | | + +### 10.8.4 Application rules + +The token-interchange basic service shall be used to build complex document communication services. Details on how to use the token-interchange basic service when building complex services are specified in the corresponding complex service specification (in other ITU-T Recommendations). + +#### 10.8.4.1 Application rules when using DTAM-TK + +This is the only possibility for the token-interchange basic service. The full service element of DTAM-TK is used. + +When the service is requested, the following steps shall be followed: + +- Step 1: A DTAM-DM association shall be established with DTAM-DM-Bind, identifying BS 8. +- Step 2: The operations provided in the DTAM-TK SE can be issued, in order to request and/or interchange the application token. +- Step 3: The DTAM-DM association shall be released with DTAM-DM-Unbind. + +# Appendix I + +## Use of further communication modules + +(This appendix does not form an integral part of this Recommendation) + +This appendix contains restrictions needed when using some of the services defined in this Recommendation in conjunction with communication modules not considered in clause 8. + +This appendix considers the following communication modules, which can be used for facsimile communication or file transfer purposes: + +- Document Transfer And Manipulation – Bulk Transfer – Transparent Mode (DTAM-BT-TM); +- Facsimile group 3 (FAX3); +- File Transfer, Access and Manipulation (FTAM). + +For each of these communication modules, the following subclauses give information about: + +- description; +- services, protocols and profiles; +- use for document communication; + +as far as they are relevant for some services of this Recommendation. + +Whenever a service of this Recommendation makes use of one of these communication modules, the rules given in the corresponding Standards or Recommendations apply. Constraints and restrictions to communication modules required by services of this Recommendation are defined in clause 10. + +Furthermore, this appendix considers the following communication applications, that are known as telematic services in the CCITT/ITU-T nomenclature: + +- Facsimile group 4 (FAX4) application; +- Binary File Transfer (BFT) application. + +These communication applications are specified on top of communication modules that are mentioned in this Recommendation. + +## **I.1 Document Transfer And Manipulation – Bulk Transfer – Transparent Mode (DTAM-BT-TM)** + +### **I.1.1 Description** + +The communication module DTAM-BT-TM is used to transmit full documents between two communicating entities, following the end-to-end communication principle. + +The DTAM-BT-TM protocol maps directly to the session services. An adaptation to the X.215/X.225 session (see III.2.1) is defined in Recommendation T.62 *bis* (see III.2.1). + +### **I.1.2 Services, protocols and profiles** + +The DTAM-BT-TM services are defined in Recommendation T.432 (see III.2.2). + +The DTAM-BT-TM protocol is specified in Recommendation T.433 (see III.2.2), and conforms to the Communication Application Profile (CAP) defined in Recommendation T.521 (see III.2.2). + +### **I.1.3 Use for document communication** + +The communication module DTAM-BT-TM provides the protocol platform for the CCITT/ITU-T telematic services facsimile group 4 and binary file transfer. These communication applications are introduced at the end of this appendix. + +The communication module DTAM-BT-TM may be used by the following basic services of this Recommendation: + +- storing basic service; +- distribution basic service. + +In this case, the following procedures and restrictions apply: + +- full documents of any document format can be transmitted as binary files, but cannot be distinguished from other binary files; +- the document format is not negotiable in the association establishment phase; +- document communication in the sense of this Recommendation can only be carried out through bilateral agreement between communicating entities. + +## **I.2 Facsimile group 3 (FAX3)** + +### **I.2.1 Description** + +The communication module FAX3 is used to transmit full documents between two communicating entities, following the end-to-end communication principle. + +Two optional facilities may be used for the transfer of ODA documents: + +- ODA/PM26 facility: transmission of data streams conforming to the ODA document format PM-26 (see III.1.2); +- BFT facility (see I.5). + +These optional facilities are described in Recommendation T.30 (see III.2.3). + +### **I.2.2 Services, protocols and profiles** + +The ODA/PM26 facility is negotiated during the establishment phase, and the negotiation is limited to the indication of the facility supported by the receiver and selected by the sender. + +The ODA/PM26 facility requires the use of the Error Correction Mode (ECM) option. + +### **I.2.3 Use for document communication** + +ODA documents conforming to the PM-26 document format and binary files can be transmitted using FAX3 options. + +The communication module FAX3 may be used by the following basic services of this Recommendation: + +- storing basic service; +- distribution basic service. + +In the case of ODA documents conforming to the PM-26 document format, the following procedures and restrictions apply: + +- ODA documents are transmitted using the ECM option; +- the document format PM-26 is negotiated in the connection establishment phase. + +Otherwise, the following procedures and restrictions apply: + +- full documents of any document format can be transmitted as binary files, but cannot be distinguished from other binary files; +- the document format is not negotiable in the connection establishment phase for BFT purposes; +- document communication in the sense of this Recommendation can only be carried out through bilateral agreement between communicating entities. + +## **I.3 File Transfer, Access and Manipulation (FTAM)** + +### **I.3.1 Description** + +The communication module FTAM allows for communicating entities to access and manage remote virtual file stores. FTAM enables the transfer of files that are contained in the virtual file stores. + +FTAM files are not related to ODA documents. + +FTAM communication applications are based on the end-to-end communication principle. + +### **I.3.2 Services, protocols and profiles** + +The FTAM services and protocols are defined and specified in ISO/IEC 8571 (see III.2.5). + +The following application profiles for FTAM are defined: + +- AFT11: Simple file transfer; +- AFT12: Positional file transfer (Flat); +- AFT13: File transfer service (Hierarchical); +- AFT22: Positional file access (Flat); +- AFT23: Full file access (Hierarchical); +- AFT3: File management; +- AFT4: File store management service. + +Two additional profiles AFTnn give general definitions and constraints (see III.2.5). + +### **I.3.3 Use for document communication** + +ODA documents can be transmitted by FTAM and have to be identified as "ISO FTAM Unstructured Binary" document type. However, since files that do not contain ODA documents can have the same document type, it is left to the user of the communication application that remotely access files using FTAM to know that a given file contains an ODA document. + +The communication module FTAM may be used by the following basic services of this Recommendation: + +- storing basic service; +- distribution basic service. + +In this case, the following procedures and restrictions apply: + +- full documents of any document format can be transmitted as binary files, but cannot be distinguished from other binary files; +- the document format is not negotiable in the connection establishment phase; +- document communication in the sense of this ITU-T Recommendation can only be carried out through bilateral agreement between communicating entities. + +## **I.4 Facsimile group 4 (FAX4) application** + +### **I.4.1 Description** + +The communication application profile for FAX4 is used to transmit full documents between two communicating entities, following the end-to-end communication principle. + +FAX4 documents are a subset of ODA documents belonging to the raster graphics content architecture level and the formatted document architecture class. FAX4 documents can only be transferred and managed but cannot be manipulated. + +### **I.4.2 Services, protocols and profiles** + +The transmission protocol conforms to the CAP given in Recommendation T.521 (see III.2.2), if the DTAM-BT-TM communication module is used. + +FAX4 documents conform to the DAP defined in Recommendation T.503 (see III.2.6). + +### **I.4.3 Use for document communication** + +The communication application profile for FAX4 is used with BFT to realize the following basic services of this Recommendation: + +- storing basic service; +- distribution basic service. + +In this case, the following procedures and restrictions apply: + +- full documents of any document format can be transmitted as binary files, but cannot be distinguished from other binary files; +- the document format is not negotiable in the association establishment phase; +- document communication in the sense of this Recommendation can only be carried out through bilateral agreement between communicating entities. + +## **I.5 Binary File Transfer (BFT) application** + +### **I.5.1 Description** + +The communication application BFT is used to transmit full documents between two communicating entities, following the end-to-end communication principle. + +BFT documents are amounts of binary information which is arranged as a linear sequence of octets with synchronization points set every $n$ octets. BFT documents can only be transferred and managed but cannot be manipulated. BFT documents are not related to ODA documents. + +BFT, as an option of telematic services, uses the DTAM-BT-NM or DTAM-BT-TM communication modules for file transmission. Furthermore, BFT can be carried out using FAX3, MHS or Teletex communication modules. + +### **I.5.2 Services, protocols and profiles** + +If BFT is based on the communication module DTAM-BT-NM, the transmission protocol conforms to the CAP defined in Recommendation T.522. + +If BFT is based on the communication module DTAM-BT-TM, the transmission protocol conforms to the CAP given in Recommendation T.521 (see III.2.2). + +### **I.5.3 Use for document communication** + +ODA documents can be transmitted as binary files. + +The communication application BFT may be used by the following basic services of this Recommendation: + +- storing basic service; +- distribution basic service. + +In this case, the following procedures and restrictions apply: + +- full documents of any document format can be transmitted as binary files, but cannot be distinguished from other binary files; +- the document format is not negotiable in the connection establishment phase; +- document communication in the sense of this Recommendation can only be carried out through bilateral agreement between communicating entities. + +# **Appendix II** + +## **Implementation guidelines** + +(This appendix does not form an integral part of this Recommendation) + +This appendix contains guidelines for implementors of the basic services defined in this Recommendation. + +In subclause II.1, general aspects are considered which are valid for every basic service. + +Subsequent subclauses give specific guidance to implement the following basic services of this Recommendation: + +- storing basic service; +- distribution basic service; +- retrieval basic service; +- storing-and-retrieval basic service; +- manipulation basic service; +- pointing basic service; +- multi-pointing basic service; +- token-interchange basic service. + +## **II.1 General implementation guidelines** + +In this subclause, general topics, valid for every basic service, are considered. + +### **II.1.1 Amount of information to be transferred** + +Message Handling Systems may restrict the transferable overall message size to some value that may not be sufficient for document transfers. Therefore, a different mechanism to transmit high-volume documents is necessary. + +One solution is to use other communication modules than MHS. + +Another solution is to put a reference on these high-volume documents in a MHS message and send this MHS message to the remote communicating entity or entities. The documents represented by the reference can be accessed upon request using other communication modules. Implementations of this mechanism of external references may be based on the Distributed Office Applications Model (DOAM) (see III.2.1) using Referenced Object Access (ROA) protocols (see III.2.1). + +### **II.1.2 Mapping of DFR access rights to access rights of this Recommendation** + +Table II.1 provides a mapping of DFR access rights, defined in ISO/IEC 10166-1 to store access rights of this Recommendation, defined in 9.1.4. + +NOTE – In DFR, 'no access' is not explicitly stated but has the same effect if all other rights are absent. 'Add-only' does not exist in DFR. Therefore, the ITU-T Recommendation store access rights are a superset of the DFR access rights. This is because this Recommendation considers document fragments too, which is outside the scope of DFR. + +### **II.1.3 Quality of Service (QOS)** + +QOS is defined, in the context of communication applications, as the collective effect of service performances which determine the degree of satisfaction of a user of the service or communication application. + +QOS is defined and measured in terms of parameters related to speed, accuracy and dependability of the normal phases of the communication between communicating entities; i.e. access, information transfer, and disengagement. + +TABLE II.1/T.190 + +#### **Mapping of DFR access rights to store access rights of this Recommendation** + +| DFR access rights | Recommendation T.190
store access rights | +|--------------------|---------------------------------------------| +| – | 'no access' | +| read | 'read-only' | +| – | 'add-only' | +| extended-read | 'extended-read' | +| read-modify | 'read-only' and 'modify' | +| read-modify-delete | 'read-only' and 'modify' and 'delete-only' | +| owner | 'full-access' | + +In the context of the services specified in this Recommendation, those kinds of QOS parameters are left to the communication modules used. Then, QOS is related to the services as far as it is related to the involved communication modules. + +Then, the QOS is related to particular service attributes specified in clause 9. These are: + +- "document format"; +- "functionality level"; +- "communication type"; +- "communication module". + +These are the service attributes that are chosen by implementors, subject to the rules specified in this Recommendation. The selection of values for these attributes implies the quality of the service. + +As explained in 9.3, the normal way of giving values to these attributes is the following, that also affects the final QOS of the service: + +- a DAP level is chosen (value of "document format" service attribute). This implies a level of QOS. This selection has no effect in the rest of selections; +- a functionality level (i.e., on which objects the service will be applied) is chosen (value of the "functionality level" service attribute). This selection will limit the possibilities of selection for the rest of attributes; +- end-to-end or store-and-forward communication type is chosen (value of "communication type" service attribute). This selection has a clear implication on some QOS of the services. For example, selection of store-and-forward communication for a strongly interactive application will affect global performance of the service. It may happen that there is no possibility to implement a given service with the chosen communication type (and, may be, functionality level). In any case, the selection of the communication type may restrict the possible communication modules; +- for the combination of values of the two previous attributes, the normal situation is that only one possible communication module is possible. In this case, the QOS of that module will affect the QOS of the service. It also may happen that there are no possible communication modules for the given combination of attribute values. In this case, a new selection has to be made, changing then the QOS parameters. Finally, sometimes a choice has to be made between more than one communication module, that, normally, will imply different QOS parameter values. + +## II.1.4 Security + +A security architecture for open systems is defined in ISO 7498-2 (see III.2.1). + +Security can be achieved by administrative, logical or physical means. Only logical means are considered by this Recommendation, and should be provided mainly by the communication modules. + +Logical means to provide security are built on specific implemented mechanisms such as: + +- Authentication: It is used to verify the identity of the communicating entity using the peer-to-peer authentication of layers in the OSI structure. A simple possibility makes use of password techniques. A more sophisticated approach is the use of cryptographic means and exchange of public or secret keys. +- Access control: It is achieved by limiting the ability of communicating entities to access data in host systems. It is supported in communication applications by using profiles, which allow reading, archiving, modifying, full access, etc. Profiles have to be identified during the communication establishment phase. Communication application providers may maintain black lists to control (and block if necessary) the access to their systems. +- Data confidentiality: It means protection of data against unauthorised reading when it is transmitted or stored. Mechanisms are file encryption/decryption techniques in document stores, servers or communication applications. +- Data integrity: It is provided by use of reliable transfer protocols and error detection/correction algorithms. + +Implementations of applications, which use the basic services of this Recommendation, should use existing security mechanisms of the OSI structure or should adapt or develop their own security features, considering the hints above. + +## **II.2 Specific implementation hints for the storing basic service** + +The storing basic service has only one possible value for the "functionality level" attribute. Then, the first selection to be made is between end-to-end and store-and-forward type of communication. For the first option, there is also a choice between two possible communication modules (DFR or DTAM-BT-NM); for the second option, only MHS can be used. + +The following hints may be useful for implementors of this basic service: + +- if only some of the three possible communication modules are available, the selection can be done between those already available; +- the selection of the communication module heavily depends on the available communication modules of the intended recipients of the documents. Those should be used; +- the availability of other services, like distribution, may also constrain the selection of the communication module. It is better not to use different communication modules; +- use of DFR takes precedence when documents are sent to stores with a particular DFR structure; +- when none of the previous hints need to be applied, DTAM-BT-NM is the best selection. + +## **II.3 Specific implementation hints for the distribution basic service** + +The distribution basic service has only one possible value for the "functionality level" attribute. Then, the first selection to be made is between end-to-end and store-and-forward type of communication. For the first selection, there is also a choice between two possible communication modules (DFR or DTAM-BT-NM); for the second, only MHS can be used. + +The following hints may be useful for implementors of this basic service: + +- if only some of the three possible communication modules are available, the selection can be done between those already available; +- the selection of the communication module heavily depends on the available communication modules of the intended recipients of the documents. Those should be used; + +- the availability of other services, like storing, may also constrain the selection of the communication module. It is better not to use different communication modules; +- use of DFR takes precedence when documents are sent to stores with a particular DFR structure; +- when none of the previous hints need to be applied, MHS is the best selection when the number of recipients is big enough, because the distribution of the document(s) could be implemented with only one operation. + +## **II.4 Specific implementation hints for the retrieval basic service** + +The retrieval basic service has several possible values for the "functionality level" attribute. Then, a second selection to be made is between end-to-end and store-and-forward type of communication. For the first selection, and for a given functionality level, only one communication module is possible (DFR, DTAM-DM or DFR/DTAM-DM, depending on the chosen functionality level); for the second, only MHS can be used. + +The following hints may be useful for implementors of this basic service: + +- the first decision should be the communication type. In principle, end-to-end is preferred, because this is normally an interactive service. However, if only MHS is available, or if it is not really required to have interactive retrieval operations, store-and-forward communication can be chosen; +- if end-to-end communication is chosen, the functionality level should be the criteria that, following the rules given in clause 10, allow to select a communication module. However, if there is an impossibility or a restriction to implement that communication module, then the preferred communication module will force the functionality level to implement. + +## **II.5 Specific implementation hints for the storing-and-retrieval basic service** + +The storing-and-retrieval basic service has several possible values for the "functionality level" attribute. Then, a second selection to be made is between end-to-end and store-and-forward type of communication. For the first selection, and for a given functionality level, only one communication module is possible (DFR, DTAM-DM or DFR/DTAM-DM, depending on the chosen functionality level); for the second, only MHS can be used. + +The following hints may be useful for implementors of this basic service: + +- the first decision should be the communication type. In principle, end-to-end is preferred, because this is normally an interactive service. However, if only MHS is available, or if it is not really required to have interactive storing and retrieval operations, store-and-forward communication can be chosen; +- if end-to-end communication is chosen, the functionality level should be the criteria that, following the rules given in clause 10, allow to select a communication module. However, if there is an impossibility or a restriction to implement that communication module, then the preferred communication module will force the functionality level to implement. + +## **II.6 Specific implementation hints for the manipulation basic service** + +The manipulation basic service has several possible values for the "functionality level" attribute. Then, a second selection to be made is between end-to-end and store-and-forward type of communication. For the first selection, and for a given functionality level, only one communication module is possible (DFR, DTAM-DM or DFR/DTAM-DM, depending on the chosen functionality level); for the second, only MHS can be used. + +The following hints may be useful for implementors of this basic service: + +- the first decision should be the communication type. In principle, end-to-end is preferred, because this is normally an interactive service. However, if only MHS is available, or if it is not really required to have interactive manipulation operations, store-and-forward communication can be chosen. However, this is only expected in very specific cases; +- if end-to-end communication is chosen, the functionality level should be the criteria that, following the rules given in clause 10, allow to select a communication module. However, if there is an impossibility or a restriction to implement that communication module, then the preferred communication module will force the functionality level to implement. + +## **II.7 Specific implementation hints for the pointing basic service** + +The pointing basic service has only one possible value for the "functionality level", "communication type" and "communication module" attributes. Then, no hints for implementors are given for this basic service. + +## **II.8 Specific implementation hints for the multi-pointing basic service** + +The multi-pointing basic service has only one possible value for the "functionality level", "communication type" and "communication module" attributes. Then, no hints for implementors are given for this basic service. + +## **II.9 Specific implementation hints for the token-interchange basic service** + +The token-interchange basic service has only one possible value for the "functionality level", "communication type" and "communication module" attributes. Then, no hints for implementors are given for this basic service. + +# **Appendix III** + +## **Bibliography** + +(This appendix does not form an integral part of this Recommendation) + +This bibliography provides additional information about document and communication architectures, so far as they are relevant for this Recommendation. + +## **III.1 Document architectures** + +### **III.1.1 Open Document Architecture (ODA) extensions** + +- ITU-T Recommendation T.419 (1994) | ISO/IEC 8613-9:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Audio content architecture.* +- ISO/IEC 8613-10:1991, *Information processing – Text and office systems – Open Document Architecture (ODA) and interchange format – Part 10: Formal specifications.* +- ITU-T Recommendation T.421 (1994) | ISO/IEC 8613-11:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Tabular structures and tabular layout.* +- ITU-T Recommendation T.424 (1994) | ISO/IEC 8613-14:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Temporal relationships and non-linear structures.* + +### III.1.2 ODA profiles + +- ISO/IEC ISP 12064:1994, *Information technology – International standardized profile FOD112 – Interchange Format and representation profile for ODA: Image applications profile.* +- ISO/IEC ISP, *Information technology – International standardized profile FOD126 – Interchange Format and representation profile for ODA: Image applications profile.* +- CCITT Recommendation T.505 (1991), *Document application profile PM-26 for the interchange of mixed content documents in processable and formatted forms.* + +## III.2 Communication architectures + +### III.2.1 Base documents + +- CCITT Recommendation T.62 bis (1988), *Control procedures for teletex and G4 facsimile services based on Recommendations X.215 and X.225.* +- CCITT Recommendation X.200 (1988) | ISO 7498:1984, *Reference model of Open Systems Interconnection for CCITT applications.* +- ISO 7498-2:1989, *Information processing systems – Open Systems Interconnection – Basic reference model – Part 2: Security architecture.* +- CCITT Recommendation X.215 (1988), *Session service definition for Open Systems Interconnection for CCITT applications.* +- ISO/8326:1987, *Information processing systems – Open Systems Interconnection – Basic connection oriented session service definition.* +- CCITT Recommendation X.225 (1988), *Session protocol specification for Open Systems Interconnection for CCITT applications.* +- ISO 8327:1987, *Information processing systems – Open Systems Interconnection – Basic connection oriented session protocol specification.* +- CCITT Recommendation X.216 (1988), *Presentation service definition for Open Systems Interconnection for CCITT applications.* +- ISO/IEC 8822:1994, *Information Technology – Open Systems Interconnection – Presentation service definition.* +- CCITT Recommendation X.226 (1988), *Presentation protocol specification for Open Systems Interconnection for CCITT applications.* +- ISO/IEC 8823-1:1994, *Information Technology – Open Systems Interconnection – Connection oriented presentation protocol: Protocol specification.* +- CCITT Recommendation X.217 (1988), *Association control service definition for Open Systems Interconnection for CCITT applications.* +- ISO 8649:1988, *Information processing systems – Open Systems Interconnection – Service definition for the Association Control Service Element.* +- CCITT Recommendation X.227 (1988), *Association control protocol specification for Open Systems Interconnection for CCITT applications.* +- ISO 8650:1988, *Information processing systems – Open Systems Interconnection – Protocol specification for the Association Control Service Element.* +- ITU-T Recommendation X.218 (1993), *Reliable transfer: Model and service definition.* +- ISO/IEC 9066-1:1989, *Information processing systems – Text communication – Reliable Transfer – Part 1: Model and service definition.* +- CCITT Recommendation X.228 (1988), *Reliable transfer: Protocol specification.* +- ISO/IEC 9066-2:1989, *Information processing systems – Text communication – Reliable Transfer – Part 2: Protocol specification.* +- CCITT Recommendation X.219 (1988), *Remote operations: Model, notation and service definition.* +- ISO/IEC 9072-1:1989, *Information processing systems – Text communication – Remote operations – Part 1: Model, notation and service definition.* +- CCITT Recommendation X.229 (1988), *Remote operations: Protocol specification.* + +- ISO/IEC 9072-2:1989, *Information processing systems – Text communication – Remote operations – Part 2: Protocol specification.* +- ISO/IEC 10031-1:1991, *Information technology – Text and office systems – Distributed-office-applications model – Part 1: General model.* +- ISO/IEC 10031-2:1991, *Information technology – Text and office systems – Distributed-office-applications model – Part 2: Distinguished-object-reference and associated procedures.* + +### **III.2.2 Document Transfer And Manipulation (DTAM)** + +- CCITT Recommendation T.431 (1992), *Document Transfer And Manipulation (DTAM) – Services and protocols – Introduction and general principles.* +- CCITT Recommendation T.432 (1992), *Document Transfer And Manipulation (DTAM) – Services and protocols – Service definition.* +- CCITT Recommendation T.433 (1992), *Document Transfer And Manipulation (DTAM) – Services and protocols – Protocol specification.* +- ITU-T Recommendation T.521 (1994), *Communication application profile BT0 for document bulk transfer based on the session service.* + +### **III.2.3 Facsimile group 3 (FAX3)** + +- ITU-T Recommendation T.4 (1993), *Standardization of group 3 facsimile apparatus for document transmission.* +- ITU-T Recommendation T.30 (1993), *Procedures for document facsimile transmission in the general switched telephone network.* + +### **III.2.4 File Transfer, Access and Manipulation (FTAM)** + +- ISO/IEC 8571-1:1988, *Information processing systems – Open Systems Interconnection – File transfer, Access and Management – Part 1: General introduction.* +- ISO/IEC ISP 10607-1:1991, *Information technology – International standardized profiles AFTnn – File transfer, access and management – Part 1: Specification of ACSE, presentation and session protocols for use by FTAM.* +- ISO/IEC ISP 10607-2:1990, *Information technology – International standardized profiles AFTnn – File transfer, access and management – Part 2: Definition of document types, constraint sets and syntaxes.* +- ISO/IEC ISP 10607-3: 1990, *Information technology – International standardized profiles AFTnn – File transfer, access and management – Part 3: AFT11, Simple file transfer service instructed.* +- ISO/IEC ISP 10607-4:1991, *Information technology – International standardized profiles AFTnn – File transfer, access and management – Part 4: AFT12, Positional file transfer service (Flat).* +- ISO/IEC ISP 10607-5:1991, *Information technology – International standardized profiles AFTnn – File transfer, access and management – Part 5: AFT22, Positional file access service (Flat).* +- ISO/IEC ISP 10607-6:1991, *Information technology – International standardized profiles AFTnn – File transfer, access and management – Part 6: AFT3, File management service.* + +### **III.2.5 Facsimile group 4 (FAX4)** + +- CCITT Recommendation T.6 (1988), *Facsimile coding schemes and coding control functions for group 4 facsimile apparatus.* +- CCITT Recommendation T.503 (1991), *A document application profile for the interchange of group 4 facsimile documents.* +- ITU-T Recommendation T.563 (1994), *Terminal characteristics for group 4 facsimile apparatus.* + +### **III.2.6 Binary File Transfer (BFT)** + +- CCITT Recommendation T.434 (1992), *Binary file transfer format for the telematic services.* +- CCITT Recommendation T.571 (1992), *Terminal characteristics for the telematic file transfer within the teletex service.* \ No newline at end of file diff --git a/marked/T/T-REC-T.191-199607-I_PDF-E/raw.md b/marked/T/T-REC-T.191-199607-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..3c145165e3dbc69910cd32d5b38f81f677ab9251 --- /dev/null +++ b/marked/T/T-REC-T.191-199607-I_PDF-E/raw.md @@ -0,0 +1,1313 @@ + + +![ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# T.191 + +(07/96) + +SERIES T: TERMINAL EQUIPMENTS AND PROTOCOLS +FOR TELEMATIC SERVICES + +--- + +**Cooperative document handling (CDH) – Joint +synchronous editing (point-to-point)** + +ITU-T Recommendation T.191 + +(Previously “CCITT Recommendation”) + +--- + +# FOREWORD + +The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). + +ITU-T Recommendation T.191 was prepared by ITU-T Study Group 8 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 3rd of July 1996. + +# --- NOTE + +In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +© ITU 1996 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +# CONTENTS + +| | | Page | +|---|--------------------------------------------------------------------------------|-------------| +| 1 | Scope ..... | 1 | +| 2 | References ..... | 1 | +| 3 | Definitions ..... | 2 | +| 4 | Abbreviations ..... | 2 | +| 5 | Overview of joint synchronous editing (point-to-point) ..... | 2 | +| | 5.1 Basic procedures of joint synchronous editing (point-to-point) ..... | 3 | +| | 5.2 Configuration of joint synchronous editing (point-to-point) ..... | 3 | +| 6 | Definition of document conferencing and remote presentation service ..... | 6 | +| | 6.1 The use of basic services ..... | 6 | +| | 6.2 Formal definition of joint synchronous editing (point-to-point) ..... | 6 | +| | 6.2.1 Document related service attributes ..... | 6 | +| | 6.2.1.1 document location ..... | 6 | +| | 6.2.1.2 document copies ..... | 6 | +| | 6.2.1.3 document access rights ..... | 6 | +| | 6.2.1.4 store access rights ..... | 7 | +| | 6.2.1.5 document format ..... | 7 | +| | 6.2.1.6 functionality level ..... | 7 | +| | 6.2.2 Communication related service attributes ..... | 7 | +| | 6.2.2.1 number of communicating entities ..... | 7 | +| | 6.2.2.2 communication type ..... | 7 | +| | 6.2.2.3 communication module ..... | 8 | +| 7 | Profiles for joint synchronous editing ..... | 8 | +| | 7.1 Document application profile for joint synchronous editing ..... | 8 | +| | 7.1.1 ODA document format ..... | 8 | +| | 7.1.1.1 DAPs based on the processable form ..... | 8 | +| | 7.1.1.2 DAPs based on the formatted form (further study) ..... | 8 | +| | 7.1.2 Other formats ..... | 9 | +| | 7.2 Communication modules for joint synchronous editing (point-to-point) ..... | 9 | +| | 7.2.1 DTAM-DM communication module ..... | 9 | +| | 7.2.1.1 Profile for DTAM-DM ..... | 9 | +| | 7.2.1.2 Profile for ODA abstract interface ..... | 9 | +| | 7.2.1.3 The units of manipulation ..... | 9 | +| | 7.2.2 DTAM-TK communication module ..... | 10 | +| | 7.2.3 DTAM-BT communication module ..... | 10 | +| | 7.2.4 DFR/DTAM-DM communication module ..... | 10 | +| | 7.3 Summary of modules for joint synchronous editing (point-to-point) ..... | 11 | +| 8 | The use of service primitives and parameters for communication modules ..... | 11 | +| | 8.1 DTAM-DM service primitives and parameters ..... | 11 | +| | 8.1.1 Abstract-bind operation ..... | 11 | +| | 8.1.1.1 Bind-Argument parameters ..... | 11 | +| | 8.1.1.2 Bind-Result parameters ..... | 12 | +| | 8.1.1.3 Bind-error parameters ..... | 13 | +| | 8.1.2 Unbind service parameters ..... | 13 | +| | 8.1.3 The use of A-ABORT service parameters ..... | 13 | +| | 8.1.4 DTAM Remote Document Manipulation Services and parameters ..... | 13 | +| | 8.1.4.1 Service parameters for remote document access services ..... | 13 | +| | 8.1.4.2 Service parameters for the remote document manipulation services ..... | 15 | +| | 8.1.4.2.1 Store type of manipulation ..... | 15 | +| | 8.1.4.2.2 Retrieve type of manipulation ..... | 16 | +| | 8.1.4.2.3 Action type of manipulation ..... | 16 | + +| | Page | +|--------------------------------------------------------------------------------------------------------|-------------| +| 8.2 DTAM-TK service primitives and parameters ..... | 18 | +| 8.2.1 TK-TOKEN-PLEASE service parameters ..... | 18 | +| 8.2.2 TK-TOKEN-GIVE service parameters ..... | 18 | +| 8.3 DTAM-BT service primitives and parameters ..... | 18 | +| 8.4 DFR/DTAM-DM service primitives and parameters ..... | 19 | +| 8.4.1 abstract-bind operation ..... | 19 | +| 8.4.1.1 Bind-Argument parameters ..... | 19 | +| 8.4.1.2 Bind-Result parameters ..... | 20 | +| 8.4.1.3 Bind-error parameters..... | 20 | +| 8.4.2 Unbind service parameters ..... | 21 | +| 8.4.3 The use of A-ABORT service parameters..... | 21 | +| 8.4.4 The use of DTAM-DM Remote Document Manipulation Services and parameters ..... | 21 | +| Annex A – Examples of remote manipulations using DTAM abstract service and ODA abstract interface..... | 21 | +| Annex B – Some examples of use of parameters for the remote document manipulation ..... | 23 | +| B.1 DM-CREATE abstract service..... | 23 | +| B.2 DM-DELETE abstract service ..... | 24 | +| B.3 DM-COPY abstract service..... | 25 | +| Annex C – Error Handling of manipulation service by CDH application..... | 27 | + +# **SUMMARY** + +This Recommendation specifies one complex service, "joint synchronous editing (point-to-point)", where two users are communicating for the purpose to produce a new document, revise an existing document and view an existing document jointly. + + + +# COOPERATIVE DOCUMENT HANDLING (CDH) – JOINT SYNCHRONOUS EDITING (POINT-TO-POINT) + +(Geneva, 1996) + +## 1 Scope + +The T.190-Series of Recommendations specify the document communication services to be provided on top of existing base standards or profiles, giving constraints on them and rules on how to use and combine them. + +The Open Document Architecture (ODA) and associated profiles specify the means to represent and interchange multimedia documents. + +The Document Transfer and Manipulation (DTAM) and Document Filing & Retrieval (DFR) specify interchange, remote manipulation and management of documents at the application layer of the Open Systems Interconnection (OSI). + +Recommendation T.190 defines the framework for document communication services and set of basic services. Based on the framework and the basic services, the T.190-Series of Recommendations define a set of complex services such as Asynchronous document production, Sequential document production, Joint synchronous editing and Joint presentation/viewing, by combining basic services. + +This Recommendation specifies one complex service, "joint synchronous editing (point-to-point configuration)", where two users are communicating for the purpose to produce a new document, revise an existing document and view an existing document jointly. + +## 2 References + +The following Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision: all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. + +- ITU-T Recommendation T.190 (1995), *Cooperative Document Handling (CDH) – Framework and basic services*. +- CCITT Recommendation T.431 (1992), *Document Transfer and Manipulation (DTAM) – Services and protocols – Introduction and general principles*. +- CCITT Recommendation T.432 (1992), *Document Transfer and Manipulation (DTAM) – Services and protocols – Service definition*. +- CCITT Recommendation T.433 (1992), *Document Transfer and Manipulation (DTAM) – Services and protocols – Protocol specification*. +- ITU-T Recommendation T.435 (1995), *Document Transfer and Manipulation (DTAM) – Services and protocols – Abstract service definition and procedures for confirmed document manipulation*. +- ITU-T Recommendation T.436 (1995), *Document Transfer and Manipulation (DTAM) – Services and protocols – Protocol specifications for confirmed document manipulation*. +- ISO/IEC 10166-1:1991, *Information technology – Text and office systems – Document Filing and Retrieval (DFR) – Part 1: Abstract service definition and procedures*. +- ISO/IEC 10166-1:1991, *Information technology – Text and office systems – Document Filing and Retrieval (DFR) – Part 1: Abstract service definition and procedures – Technical Corrigendum 1: 1994 and Technical corrigendum 2: 1994*. + +- ISO/IEC 10166-2:1991, *Information technology – Text and office systems – Document Filing and Retrieval (DFR) – Part 2: Protocol specification.* +- CCITT Recommendation T.522 (1992), *Communication application profile BT1 for document bulk transfer.* +- ITU-T Recommendation T.502 (1994), *Document application profile PM-11 for the interchange of simple structure, character content documents in processable and formatted forms.* +- ITU-T Recommendation T.505 (1994), *Document application profile PM-26 for the interchange of enhanced structure, mixed content documents in processable and formatted forms.* +- ITU-T Recommendation T.506 (1993), *Document Application Profile PM-36 for the interchange of extended document structure and mixed content documents in processable formatted forms.* +- ISO/IEC ISP, *International Standard Profiles ADF12069 – Application profiles for Document Filing and Retrieval (DFR).* +- ISO/IEC ISP, *International Standard Profiles AOD15129 – Application profiles for Open Document Architecture (ODA): Profiles for interactive manipulation of ODA documents.* + +## 3 Definitions + +For the purposes of this Recommendation, the definitions given in Recommendation T. 190 apply. + +## 4 Abbreviations + +For the purposes of this Recommendation, the following abbreviations are used. + +| | | +|---------|-------------------------------------| +| ACSE | Association Control Service Element | +| ADF | Application profile for DFR | +| AOD | Application profile for ODA | +| CAP | Communication Application Profile | +| DAP | Document Application Profile | +| DFR | Document Filing and Retrieval | +| DTAM | Document Transfer and Manipulation | +| DTAM-BT | DTAM Bulk Transfer | +| DTAM-DM | DTAM Document Manipulation | +| DTAM-TK | DTAM application Token | +| ODA | Open Document Architecture | +| OSI | Open Systems Interconnection | +| ROSE | Remote Operations Service Element | +| RTSE | Reliable Transfer Service Element | + +## 5 Overview of joint synchronous editing (point-to-point) + +Joint synchronous editing (point-to-point) supports document creation or presentation by two-users cooperatively on real-time basis. The communication model of this complex service is based on extended client-to-server model where two communication entities play the role of both client and server simultaneously. In this communication model, all clients have the copy of the same document and document processing capabilities, which are in line with features required by this Recommendation. + +In order to keep consistency of the document copies located at the client, floor control (token control) is used. This ensures that the possibility for the two clients to manipulate the document is limited. Therefore with the result of modification or presentation, all the document copies located at the client must be always the same during and after the joint synchronous editing service. + +Joint synchronous editing covers various kinds of applications, such as co-writing of multimedia documents, co-development of software, computer base training and educating (CBT), electronic contract, remote CAD system, medical application. + +This Recommendation specifies the profiles for the standard document, i. e. "Document Application profile", and the profile for the standard communication protocol, i.e. "Communication Application profile" and "terminal characteristics", which may be used for joint synchronous editing service. + +## 5.1 Basic procedures of joint synchronous editing (point-to-point) + +The basic procedure of the joint synchronous editing consists of document pre-manipulation/presentation phase, and joint synchronous editing phase as illustrated in Figure 1. + +### 1) *Document Pre-manipulation /Presentation phase* (optional) + +In this phase, all the documents to be revised or viewed are transmitted to the other terminal before joint synchronous editing. Storing and retrieving all the documents to/from the document store at the remote site, both terminals possess the same copies of the documents at the start of the joint synchronous editing service. This phase must require document bulk transfer function or document filing & retrieval function. + +This phase is optionally used. + +### 2) *Joint Synchronous editing Phase* (mandatory) + +This phase includes the following sub-procedures, association establishment, opening of the documents, manipulation/presentation of the opened documents (including token interchange), closing of the documents, and association release. During this phase, both users can manipulate or view a part of the documents, i.e. document fragments remotely. + +NOTE – New documents used to be revised or viewed jointly may be created locally. This is out of the scope of this Recommendation. + +## 5.2 Configuration of joint synchronous editing (point-to-point) + +Joint synchronous editing is based on the extended server client model, where two users play the role of both server and client alternately. In this model, all the conference terminals have the same document processing capabilities and the same document. + +In this service, two users can manipulate or present documents by using the basic services defined in Recommendation T.190. Each communication entity consists of the document process, the basic services, the documents and the application as illustrated in Figure 2. Application is out of scope of this Recommendation. + +Figure 2 a) shows the situation where terminal 1 plays the role of the client and terminal 2 plays the role of the server. In this situation, terminal 1 which possesses an application token can manipulate the copy of the documents. + +If, for example, the terminal 1 edits document fragment, then the local editing process is executed by the local document process. At the same time, the local editing command may be converted to standardized protocol data by basic services at the client, and the standardized protocol data may be conveyed to the remote server. At the server, standardized protocol data may be converted to the corresponding local editing command via basic services at the remote server. Finally, local editing command is executed by the document process at the server. + +After the token interchange procedure, Figure 2 b) shows the situation where the terminal 2 plays the role of the client and the terminal 1 plays the role of the server. + +![Sequence diagram showing the basic procedures of joint synchronous editing between Client A and Client B. The diagram is divided into three main phases: Document creation (out of scope), Document pre-Manipulation phase (Optional), and Joint synchronous editing phase. The Joint synchronous editing phase includes steps for Association establishment, Transfer 'Doc.', Association release, Opening of 'Doc.', Manipulation or presentation, Request token, Give token, Token interchange, Closing of 'Doc' with save Doc., and Association release.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +The diagram illustrates the basic procedures of joint synchronous editing between Client A and Client B. It is organized into three main phases: + +- Document creation (out of scope of this Rec.):** This phase is indicated by a vertical double-headed arrow on the left. +- Document pre-Manipulation phase (Optional):** This phase is also indicated by a vertical double-headed arrow on the left. +- Joint synchronous editing phase:** This phase is the main focus of the diagram and includes the following steps: + - Association establishment:** Client A sends a message to Client B. + - Transfer "Doc.":** Client A sends the document to Client B. + - Association release:** Client A sends a message to Client B. + - Opening of "Doc.":** Client B opens the document. + - Manipulation or presentation:** Both clients perform manipulation or presentation on the document. + - Request token:** Client A requests a token from Client B. + - Give token:** Client B gives a token to Client A. + - Token interchange:** This step is repeated twice, indicating a cycle of token exchange. + - Closing of "Doc" with save Doc.:** Client A sends a message to Client B. + - Association release:** Client A sends a message to Client B. + +The diagram uses various symbols to represent documents and document stores. Documents are shown as stacks of paper, and document stores are shown as cylinders. Arrows indicate the flow of data and control messages between the clients and their respective document stores. + +Sequence diagram showing the basic procedures of joint synchronous editing between Client A and Client B. The diagram is divided into three main phases: Document creation (out of scope), Document pre-Manipulation phase (Optional), and Joint synchronous editing phase. The Joint synchronous editing phase includes steps for Association establishment, Transfer 'Doc.', Association release, Opening of 'Doc.', Manipulation or presentation, Request token, Give token, Token interchange, Closing of 'Doc' with save Doc., and Association release. + +FIGURE 1/T.191 + +Basic procedures of joint synchronous editing + +T0824820-95/d01 + +![Diagram a) showing Token exchange between Terminal 1 client and Terminal 2 Server.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +Diagram a) illustrates the initial state of a joint synchronous editing session. It shows two terminals connected via a central Network (represented by a circle). + Terminal 1 (client) contains an Application layer, a Document process, and Basic services. A Token (represented by a small circle) is located outside the Application layer. Arrows indicate data flow from the Application layer to the Document process, and from the Document process to the Basic services. + Terminal 2 (Server) contains an Application layer, a Document process, and Basic services. Arrows indicate data flow from the Basic services to the Document process, and from the Document process to the Application layer. + The label "Token exchange" is positioned below Terminal 1, and the label "a)" is centered below the Network circle. + +Diagram a) showing Token exchange between Terminal 1 client and Terminal 2 Server. + +![Diagram b) showing Document flow from Terminal 1 Server to Terminal 2 client.](5b4e774d63e0e0ed73801a9247755e5f_img.jpg) + +Diagram b) illustrates the state of the session after a document update. The roles of the terminals are reversed compared to diagram a). + Terminal 1 (Server) contains an Application layer, a Document process, and Basic services. Arrows indicate data flow from the Basic services to the Document process, and from the Document process to the Application layer. + Terminal 2 (client) contains an Application layer, a Document process, and Basic services. A Token is located outside the Application layer. Arrows indicate data flow from the Application layer to the Document process, and from the Document process to the Basic services. + The label "b)" is centered below the Network circle. + +Diagram b) showing Document flow from Terminal 1 Server to Terminal 2 client. + +T0824840-95/d02 + +Doc. Document + +FIGURE 2/T.191 + Configuration of joint synchronous editing (point-to-point) + +## **6 Definition of document conferencing and remote presentation service** + +## **6.1 The use of basic services** + +Basic services which are the fundamental document communication service, are defined in Recommendation T.190. By combining these basic services, new complex services may be defined. The following basic services are used to realize joint synchronous editing (point-to-point). + +### 1) *Storing basic service* (optional) + +Storing basic service may be optionally used to transfer the document at pre-manipulation/presentation phase defined in 5.1. + +### 2) *Storing and Retrieval basic service* (optional) + +If each terminal supports document store, Storing and Retrieval basic service may be optionally used to transfer or retrieve the document at pre-manipulation/presentation phase defined in 5.1. + +In the case that pre-manipulation/presentation phase is supported, either storing basic service or storing & retrieval basic service shall be used. + +### 3) *Manipulation basic service* (mandatory) + +Manipulation basic service shall be used to manipulate the remote document fragments stored in the peer entity during the joint synchronous editing phase defined in 5.1. + +### 4) *Token interchange basic service* (mandatory) + +Token interchange basic service shall be used to control the application token during the joint synchronous editing phase defined in 5.1. In this service, the terminal which possesses an application token can manipulate the document or the document fragments. + +### 5) *Pointing basic service* (mandatory) + +Pointing basic service shall be used to inform the peer user of the specific document fragment to be paid attention to. + +## **6.2 Formal definition of joint synchronous editing (point-to-point)** + +This subclause defines the joint synchronous editing by means of the components and design rules for basic services, defined in Recommendation T.190 + +### **6.2.1 Document related service attributes** + +This complex service may be formalized by using the following document related service attributes defined in Recommendation T.190. + +#### **6.2.1.1 document location** + +In this complex service, the client manipulates the remote document at the peer entity, i.e. the server. Furthermore, the client has also the local copy of the documents which are identical to the documents at the remote server because the role of client/server may be altered by the token interchange. Therefore, the value of the service attribute "document location" shall take 'local' and 'remote'. + +#### **6.2.1.2 document copies** + +As defined in 6.2.1.1, each user has completely the same copy of the documents. Therefore, the value of the service attribute "document copies" shall take 'several'. + +#### **6.2.1.3 document access rights** + +This complex service requires to read, delete, add and modify the existing document fragments. Therefore, the value of the service attribute "document access rights" shall take 'full access'. + +#### 6.2.1.4 store access rights + +This complex service requires to read the existing document, update the modified document or add a new document. On the other hand, this complex service does not allow to delete the existing document. Therefore, the value of the service attribute "store access rights" shall take 'read-only', 'modify', and 'add-only'. + +#### 6.2.1.5 document format + +This complex service shall take one of the following possible values, depending on the desired document format. + +FOD11 (PM11)', FOD26 (PM26)', FOD36 (PM36)' + +#### 6.2.1.6 functionality level + +The service object for this complex service shall be document store, one or more documents and one or more document fragments. Therefore, the value of service attributes "functionality level" shall take 'D-F-SF'. + +Table 1 shows the summary of the document related service attribute, attribute value(s) and value description. + +TABLE 1/T.191 + +#### **Values for document related service attributes for the conferencing and remote presentation type of CDH** + +| Service attribute | Attribute value(s) | Value description | +|--------------------------|---------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------| +| "document location" | 'local' and 'remote' | The client has also the local copy of the documents which are identical to the documents at remote the server | +| "document copies" | 'several (two)' | Each user has completely the same copy of the documents | +| "document access rights" | 'full access' | Both users can manipulate the document fragments | +| "store access rights" | 'read-only', 'modify' and 'add-only' | Both users can read the existing document, update the modified document, and add a new document, but cannot delete the existing documents | +| "document format" | FOD11 (PM11)',
FOD26 (PM26)',
FOD36 (PM36)' | This service attribute shall take only one of the possible values, depending on the desired document format | +| "functionality level" | D-F-SF | Document store, one or more documents and one or more document fragments shall be used | + +### 6.2.2 Communication related service attributes + +This complex service may be formalized by using the following communication related service attributes defined in Recommendation T.190. + +#### 6.2.2.1 number of communicating entities + +This complex service is based on the point-to-point configuration. Therefore, the value of service attributes "number of communicating entities" shall take 'one-to-one'. + +#### 6.2.2.2 communication type + +In this complex service, both communicating entities (a client and a server) are directly connected to perform the services. Therefore, the value of service attributes "communication type" shall take 'end-to-end'. + +#### 6.2.2.3 communication module + +DTAM-DM communication module shall be used to manipulate one or more document fragments at the remote server. DTAM-TK communication module shall be used to control the application token to prevent from simultaneous access by both users. DTAM-BT communication module may be optionally used to transfer document during pre-manipulation/presentation phase defined in this Recommendation. If this complex service supports management functions at the remote document store such as list, search or etc. DFR/DTAM-DM shall be used instead of DTAM-DM, in order to manipulate one or more document fragments at the remote server and to manage the document store at the remote server. + +Table 2 shows the summary of the communication related service attribute, attribute value(s) and value description. + +TABLE 2/T.191 + +#### Values for communication related service attributes for the joint synchronous editing (point-to-point) + +| Service attribute | Attribute value(s) | Value description | +|------------------------------------|------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| "number of communicating entities" | 'one-to-one' | Both clients manipulate documents in the peer remote servers alternatively | +| "communication type" | 'end-to-end' | Both communicating entities (clients and servers) are directly connected to perform the service | +| "communication module" | 'DTAM-DM'
'DTAM-TK'
'DTAM-BT'
'DFR/DTAM-DM' | The selection of the communication modules is restricted by the chosen values of the "functionality level" and "communication type" attributes as specified in Rec. T.190 | + +## 7 Profiles for joint synchronous editing + +## 7.1 Document application profile for joint synchronous editing + +This complex service, specified in this Recommendation, is intended to be used with ODA document format. For other formats, see 7.1.2. + +### 7.1.1 ODA document format + +Joint synchronous editing supports various types of documents depending on the specific applications. + +#### 7.1.1.1 DAPs based on the processable form + +As for the processable form, some useful DAPs have already been defined in Recommendation T.190. This complex service shall use one of the three DAPs defined in Recommendation T.190. + +Using FOD011(PM11) documents, effective collaboration or coordination of the software development may be realized by multi-user interactions. On the other hand, using FOD026(PM26) or FOD036(PM36) documents, the multimedia co-editing applications may be realized. + +#### 7.1.1.2 DAPs based on the formatted form (further study) + +This subclause is for further study. + +Formatted documents are useful for simple remote presentation, electronic contract to fill the form, or shared-navigation. Table 3 shows the examples of DAPs based on the formatted form. FOD112 and FOD126 may be used by the remote presentation/viewing service. The table mode is a new DAP which includes the tabular structures or the spreadsheet. This mode is a typical DAP to make an electronic contract with the users at a remote site. In this case, an electronic invoice can be created by the cooperation of two users. + +As the extension of the formatted form, hypermedia documents can also be considered as a new DAP for this complex service. Using the hypermedia documents (e.g. including moving pictures), the attractive navigation can be realized. + +TABLE 3/T.191 + +**Example of DAPs for CDH** + +| Document Type | Examples of DAPs | Objective | +|--------------------------------------------|---------------------------------------------------|------------------------------------------------------------------------------------| +| Processable form document | FOD026 (PM26),
FOD036 (PM36)
FOD011 (PM11) | Co-editing
Co-developing software | +| Formatted form document
(further study) | FOD112
FOD126
Table mode
Hypermedia mode | Presentation-type
Presentation-type
Electronic contract
Shared-navigation | + +### 7.1.2 Other formats + +Coding method such as MHEG, JPEG, JBIG, SGML or proprietary formats may be optionally used for this complex service in order to cover the various types of joint synchronous editing applications. + +JPEG or JBIG may be considered as one "type of coding" of ODA attributes. In such a case, JPEG or JBIG document is specified by using DAP. + +Other formats may also be used. + +## 7.2 Communication modules for joint synchronous editing (point-to-point) + +### 7.2.1 DTAM-DM communication module + +The DTAM-DM communication module is used to manipulate the document fragments of the documents at the remote server. This complex service shall use DTAM-DM except for the case that DFR/DTAM-DM is used. + +The DTAM-DM communication module is defined in Recommendation T.190. + +#### 7.2.1.1 Profile for DTAM-DM + +This complex service shall make use of either Basic Manipulation level or Basic Read Only level. + +Extended level shall not be used for this complex service. + +- In the case that this complex service selects 'basicReadOnlyLevel', then open, close, list, get, point, search abstract services shall be used. +- In the case that this complex selects 'basicManipulationLevel', then open, save, discard, close, list, get, point, search, create, delete, modify and copy abstract services shall be used. + +See Table 4. + +#### 7.2.1.2 Profile for ODA abstract interface + +Mapping of arguments between Abstract Interface and DTAM-DM operation is defined in Table A.1/ T.413. + +#### 7.2.1.3 The units of manipulation + +The units of manipulation depend on the specific document format and communication interface. If, for example, ODA is used in conjunction with ODA Abstract Interface (AI), the units are manipulated as a document fragment which can be assigned to an object identifier. + +If manipulation of smaller units than document fragment is required for easy modification of one character, the content location model needs to be introduced, which is still under study. + +TABLE 4/T.191 + +##### **Selection of DTAM-DM abstract service** + +| DTAM-DM abstract service | basicReadOlnyLevel | basicManipulationLevel | +|------------------------------------------------------------------------------|--------------------|------------------------| +| DM-DOCUMENT-OPEN | m | m | +| DM-DOCUMENT-SAVE | – | m | +| DM-DOCUMENT-DISCARD | – | m | +| DM-DOCUMENT-CLOSE | m | m | +| DM-POINT | m | m | +| DM-DOCUMENT-LIST | c | c | +| DM-GET | m | m | +| DM-SEARCH | m | m | +| DM-CREATE | – | m | +| DM-DELETE | – | m | +| DM-MODIFY | – | m | +| DM-COPY | – | m | +| DM-MOVE | – | – | +| DM-REPLACE | – | – | +| DM-RESERVE | – | – | +| DM-UNRESERVE | – | – | +| DM-MACRO-CALL | – | – | +| DM-GROUP-BEGIN | – | – | +| DM-GROUP-END | – | – | +| m    Mandatory
c    Conditional
–    Not used for this complex service | | | + +### **7.2.2 DTAM-TK communication module** + +The DTAM-TK communication module shall be used to control the application token to prevent from simultaneous access by both users. This complex service shall make use of the DTAM-TK. + +The DTAM-TK communication module is defined in Recommendation T.190. + +### **7.2.3 DTAM-BT communication module** + +The DTAM-BT communication module is used for transferring full documents between communication entities. This complex service may make use of the DTAM-BT communication module optionally. + +The DTAM-BT communication module is defined in Recommendation T.190. + +### **7.2.4 DFR/DTAM-DM communication module** + +The DFR/DTAM-DM communication module is used to manipulate the document fragments of the documents at the remote server or to manage the full document at the remote server. This complex service shall make use of the DFR/DTAM-DM except for the case that the DTAM-DM is used. + +The DFR/DTAM-DM communication module is defined in Recommendation T.190. + +## 7.3 Summary of modules for joint synchronous editing (point-to-point) + +Figure 3 shows the summary of modules for Joint Synchronous Editing (point-to-point). + +![Diagram of modules for joint synchronous editing (point-to-point) showing Client and Server architectures connected via a Network.](2cde062fd82833415971a8bd1a2cafab_img.jpg) + +The diagram illustrates the architecture for joint synchronous editing (point-to-point) between a Client and a Server, connected via a Network. + +**Client Architecture:** + +- Application:** Contains the **ODA document process** and a **Doc.** (Document) icon. +- Services:** Manipulation basic service, Pointing basic service, Token interchange basic service, and Storing basic service or storing retrieval basic service. +- Token:** A small circle icon representing a token, located above the Client box. + +**Server Architecture:** + +- Application:** Contains the **ODA document process** and a **Doc.** (Document) icon. +- Services:** Manipulation basic service, Pointing basic service, Token Inter-change basic service, and Storing basic service or storing retrieval basic service. + +**Network:** A central circle representing the network connecting the Client and Server. + +**Legend:** Doc. Document which conforms to FOD011, FOD026 or FOD036 + +**Reference:** T0824850-95/d03 + +Diagram of modules for joint synchronous editing (point-to-point) showing Client and Server architectures connected via a Network. + +FIGURE 3/T.191 + +The summary of modules for joint synchronous editing (point-to-point) + +# 8 The use of service primitives and parameters for communication modules + +## 8.1 DTAM-DM service primitives and parameters + +### 8.1.1 Abstract-bind operation + +DTAM service definition and parameters are defined in Recommendation T.435. This subclause specifies the parameter of DTAM-DM for Joint Synchronous Editing. + +#### 8.1.1.1 Bind-Argument parameters + +The parameter of Abstract-Bind service for this complex service are used as follows. See also Table 5. + +##### 1) *DTAM protocol version* + +"version-1" is specified in this complex service. + +##### 2) *Manipulation capabilities* + +This parameter is defined in Recommendation T.435. The DTAM-DM selects "manipulation level selection." + +This complex service shall make use of either 'Basic Manipulation level' or 'Basic Read Only level'. + +##### 3) *ODA application capabilities* + +This "application capabilities" is defined in Recommendation T.435 and the following sub-parameters are used: + +- i) oda document application profile; + +This parameter is defined in Recommendation T.432. + +- ii) non-basic document characteristics; + +This parameter is defined in Recommendation T.432. + +##### 4) *Bilateral information* + +- i) server name; + +This parameter is defined in Recommendation T.435. + +- ii) information; + +This parameter is defined in Recommendation T.435. + +##### 5) *Application requirements* + +This parameter is defined in Recommendation T.435. + +TABLE 5/T.191 + +#### **Use of Bind-Argument parameters** + +| Parameter name | Class | +|------------------------------------------------------------------|-------| +| dtamProtocolVersion | m | +| dtamManipulationCapabilities | m | +| odaApplicationCapabilities | m | +| dfrCapabilities | – | +| bilateralInformation | m | +| applicationRequirement | o | +| m Mandatory
o Optional
– Not used for this complex service | | + +#### **8.1.1.2 Bind-Result parameters** + +The parameter of Abstract-Bind service for this complex service are used as follows (see Table 6): + +##### 1) *server selected DTAM protocol version* + +"version-1" is specified in this complex service. + +##### 2) *ODA application capabilities* + +This "application capabilities" parameter is defined in Recommendation T.435 and the following sub-parameters are used: + +- i) oda document application profile; + +This parameter is defined in Recommendation T.432. + +- ii) non-basic document characteristics; + +This parameter is defined in Recommendation T.432. + +##### 3) *Bilateral information* + +###### i) server name; + +This parameter is defined in Recommendation T.435. + +###### ii) information; + +This parameter is defined in Recommendation T.435. + +TABLE 6/T.191 + +##### **Use of Bind-Result parameters** + +| Parameter name | Class | +|------------------------------------------------------------------|-------| +| serverSelectedDtamProtocolVersion | m | +| odaApplicationCapabilities | m | +| serverSelectedDfrVersion | – | +| bilateralInformation | o | +| m Mandatory
o Optional
– Not used for this complex service | | + +#### **8.1.1.3 Bind-error parameters** + +Bind-error parameters are defined in Recommendation T.435. + +### **8.1.2 Unbind service parameters** + +There are no argument or errors associated with the unbind-operation. + +### **8.1.3 The use of A-ABORT service parameters** + +The parameter of this service is defined in Recommendation T.435. + +### **8.1.4 DTAM Remote Document Manipulation Services and parameters** + +#### **8.1.4.1 Service parameters for remote document access services** + +Remote document access functional unit consists of DM-DOCUMENT-OPEN service, DM-DOCUMENT-SAVE service, DM-DOCUMENT-CLOSE service, DM-DOCUMENT-DISCARD service and DM-DOCUMENT-LIST service. + +##### 1) *DM-DOCUMENT-OPEN service parameters* + +Both basicReadOnlyLevel and basicManipulationLevel make use of this abstract service. The usage of arguments/results of the DM-DOCUMENT-OPEN abstract service and the OPEN abstract interface is specified in ISP AOD11. + +##### 2) *DM-DOCUMENT-CLOSE service parameters* + +Both basicReadOnlyLevel and basicManipulationLevel make use of this abstract service. The usage of arguments/results of the DM-DOCUMENT-CLOSE abstract service and the CLOSE abstract interface is specified in ISP AOD11. + +##### 3) *DM-DOCUMENT-SAVE service parameters* + +The basicManipulationLevel makes use of this abstract service. Table 7 contains the DM-DOCUMENT-SAVE arguments as defined in Recommendation T.435, and defines which of them are to be supported by this complex service. + +TABLE 7/T.191 + +###### **DM-DOCUMENT-SAVE** + +| Argument | Class | +|----------------------------------------------------------|-------| +| documentID | m | +| dfrName | – | +| documentReference | m | +| unique-reference | m | +| descriptive-reference | – | +| documentName | – | +| nonPermanentIdentifier | – | +| m    Mandatory
–    Not used for this complex service | | + +There is no corresponding AI operation with the DM-DOCUMENT-SAVE abstract service. + +The result argument of this abstract service shall not be used for this complex service. + +##### 4) *DM-DOCUMENT-DISCARD service parameters* + +The basicManipulationLevel makes use of this abstract service. Table 8 contains the DM-DOCUMENT-DISCARD arguments as defined in Recommendation T.435, and defines which of them are to be supported by this complex service. + +TABLE 8/T.191 + +###### **DM-DOCUMENT-DISCARD** + +| Argument | Class | +|----------------------------------------------------------|-------| +| documentID | m | +| dfrName | – | +| documentReference | m | +| unique-reference | m | +| descriptive-reference | – | +| documentName | – | +| nonPermanentIdentifier | – | +| m    Mandatory
–    Not used for this complex service | | + +There is no corresponding AI operation with the DM-DOCUMENT-DISCARD abstract service. + +The result argument of this abstract service shall not be used for this complex service. + +##### 5) *DM-DOCUMENT-LIST service parameters* + +Both basicReadOnlyLevel and basicManipulationLevel make use of this abstract service. The usage of arguments/results of the DM-DOCUMENT-LIST abstract service and the LIST abstract interface is specified in ISP AOD11. + +#### 8.1.4.2 Service parameters for the remote document manipulation services + +##### 8.1.4.2.1 Store type of manipulation + +This type of manipulation is used to convey document fragments from the client to the server. In other words, this type of manipulation updates documents in the server by sending the document fragments created by the client. The Create, the Modify services are for this category. + +###### 1) *DM-CREATE service parameters* + +The basicManipulationLevel makes use of this abstract service. The usage of arguments/results of the DM-CREATE abstract service and the invocation of the Create ODA abstract interface is specified in ISP AOD12. As the exceptional case of this complex service, content argument may not be used (see Annex B). + +###### 2) *DM-MODIFY service parameters* + +The basicManipulationLevel makes use of this abstract service. Table 9 defines the DM-MODIFY arguments as defined in Recommendation T.435, and defines which of them are to be supported by this complex service. + +TABLE 9/T.191 + +###### DM-MODIFY + +| Argument | Class | Description | +|------------------------------------------------------------------|-------|------------------------------------------| +| object | m | | +| documentIdentifier | o | | +| dfrName | — | | +| documentReference | — | | +| documentName | — | | +| nonPermanentIdentifier | m | The value shall be an INTEGER | +| objectValue | o | | +| odaExpression | m | The value shall be a Constituent-locator | +| otherExpression | — | | +| anyExpression | — | | +| modifications | m | | +| odaModifications | m | | +| attributeValue | m | | +| deleting | m | | +| otherModifications | — | | +| anyModifications | — | | +| m Mandatory
o Optional
— Not used for this complex service | | | + +Table 10 defines AI delete argument as defined in Recommendation T.413. + +TABLE 10/T.191 + +###### **AI modify operation** + +| Argument | Class | +|------------------------------------------------------------|-------| +| location-in-document | m | +| document | m | +| permanent | – | +| non-permanent | m | +| location | m | +| attributeValue | m | +| deleting | m | +| m     Mandatory
–     Not used for this complex service | | + +The AI "location" argument is equivalent to the DTAM-DM "odaExpression" argument. + +The result argument of this abstract service and operation shall not be used for this complex service. + +##### **8.1.4.2.2 Retrieve type of manipulation** + +This type of manipulation is used to convey the document fragments from the server to the client. In other words, this type of manipulation retrieves the document fragments from the remote server. The Get and Search services are for this category. + +###### 1) *DM-GET abstract service parameters* + +Both, basicReadOnlyLevel and basicManipulationLevel make use of this abstract service. The usage of arguments/result of the DM-GET abstract service and the GET abstract interface is specified in ISP AOD11. + +###### 2) *DM-SEARCH abstract service parameters* + +Both, basicReadOnlyLevel and basicManipulationLevel make use of this abstract service. The usage of arguments/result of the DM-SEARCH abstract service and the Search abstract interface is specified in ISP AOD11. + +##### **8.1.4.2.3 Action type of manipulation** + +This type of manipulation does not convey document fragments, but causes specific document operation to document process on remote servers. The Delete, Copy, Move and Point services are for this category. + +###### 1) *DM-DELETE service parameters* + +The basicManipulationLevel makes use of this abstract service. Table 11 defines the DM-DELETE arguments as defined in Recommendation T.435, and defines which of them are to be supported by this complex service. + +Table 12 defines AI delete argument as defined in Recommendation T.413. + +The AI "location" argument is equivalent to the DTAM-DM "odaExpression" argument. + +The result argument of this abstract service and operation shall not be used for this complex service. + +TABLE 11/T.191 + +###### **DM-DELETE** + +| Argument | Class | Description | +|---------------------------------------------------------------------------|-------|------------------------------------------| +| object | m | | +| documentIdentifier | o | | +| dfrName | – | | +| documentReference | – | | +| documentName | – | | +| nonPermanentIdentifier | m | The value shall be an INTEGER | +| objectValue | o | | +| odaExpression | m | The value shall be a Constituent-locator | +| otherExpression | – | | +| anyExpression | – | | +| m    Mandatory
o    Optional
–    Not used for this complex service | | | + +TABLE 12/T.191 + +###### **AI delete operation** + +| Argument | Class | +|----------------------------------------------------------|-------| +| location-in-document | m | +| document | m | +| permanent | – | +| non-permanent | m | +| location | m | +| m    Mandatory
–    Not used for this complex service | | + +###### 2) *DM-COPY service parameters* + +The basicManipulationLevel makes use of this abstract service. The usage of arguments/results of the DM-COPY abstract service and the Copy abstract interface is specified in ISP AOD12. As the exceptional case of this complex service, source argument may not be used (see Annex B). + +###### 3) *DM-POINT service parameters* + +Both basicReadOnlyLevel and basicManipulationLevel make use of this abstract service. Table 13 defines the DM-POINT arguments as defined in Recommendation T.435, and defines which of them are to be supported by this complex service. + +TABLE 13/T.191 + +###### **DM-POINT** + +| Argument | Class | Description | +|---------------------------------------------------------------------------|-------|------------------------------------------| +| object (objet) | m | | +| documentIdentifier | o | | +| dfrName | – | | +| documentReference | – | | +| documentName | – | | +| nonPermanentIdentifier | m | The value shall be an INTEGER | +| objectValue | o | | +| odaExpression | m | The value shall be a Constituent-locator | +| otherExpression | – | | +| anyExpression | – | | +| m    Mandatory
o    Optional
–    Not used for this complex service | | | + +There is no corresponding AI operation with the DM-POINT abstract service. + +The result argument of this abstract service shall not be used for this complex service. + +NOTE – The DM-POINT does not cause a modification of the remote document, but only points to the location of the document fragment. This service may also be used for transmitting pointing events caused by a mouse/tablet, a cursor and caret. In such a case, the situation when pointing events are sent frequently and continuously as a moving mouse or cursor, is not considered. To prevent from the above situation, a mechanism to send several pointing events at one time may be realized. However, the realization of such a mechanism is out of the scope of this Recommendation. + +## 8.2 DTAM-TK service primitives and parameters + +### 8.2.1 TK-TOKEN-PLEASE service parameters + +The parameters of this service are used as defined in Recommendation T.435. + +There is no corresponding AI operation with TK-TOKEN-PLEASE abstract service. + +The argument and result argument of this abstract service shall not be used for this complex service. + +### 8.2.2 TK-TOKEN-GIVE service parameters + +The parameters of these services are used as defined in Recommendation T.435. + +There is no corresponding AI operation with TK-TOKEN-GIVE abstract service. + +The argument and result argument of this abstract service shall not be used for this complex service. + +## 8.3 DTAM-BT service primitives and parameters + +In this complex service, both, manipulation and bulk transfer association shall not be used simultaneously but shall be used subsequently. + +The bulk transfer function for this complex service may optionally use DTAM normal mode on top of RTSE, ACSE and presentation layer. + +DTAM-BT normal mode is defined in Recommendation T.522. + +## 8.4 DFR/DTAM-DM service primitives and parameters + +Document Filing and Retrieval (DFR) may be optionally used to support the manipulation of the full document at the remote server. + +### 8.4.1 Abstract-bind operation + +DTAM service definition and parameters are defined in Recommendation T.435. This subclause specifies the parameter of the DTAM-DM for Joint Synchronous Editing. + +#### 8.4.1.1 Bind-Argument parameters + +The parameter of Abstract-Bind for this complex service are used as follows (see Table 14): + +TABLE 14/T.191 +Use of Bind-Argument parameters + +| Parameter name | Class | +|---------------------------------|-------| +| dtamProtocolVersion | m | +| dtamManipulationCapabilities | m | +| odaApplicationCapabilities | m | +| dfrCapabilities | m | +| bilateralInformation | m | +| applicationRequirement | o | +| m    Mandatory
o    Optional | | + +##### 1) *DTAM protocol version* + +"version-1" is specified in this complex service. + +##### 2) *Manipulation capabilities* + +This parameter is defined in Recommendation T.435. The DTAM-DM selects "manipulation level selection." + +This complex service shall make use of either Basic Manipulation level or Basic Read Only level. + +##### 3) *ODA application capabilities* + +This "application capabilities" is defined in Recommendation T.435 and the following sub-parameters are used: + +###### i) oda document application profile; + +This parameter is defined in Recommendation T.432. + +###### ii) non-basic document characteristics; + +This parameter is defined in Recommendation T.432. + +##### 4) *DFR Capabilities* + +This "application capabilities" is defined in Recommendation T.435 and the following sub-parameters are used: + +###### i) DFR protocol version; + +"version-2" is specified in this complex service + +###### ii) DFR profile; + +This complex service shall use either ADF11 or ADF13, depending on the specific applications. + +##### 5) *Bilateral information* + +###### i) server name; + +This parameter is defined in Recommendation T.435. + +###### ii) information; + +This parameter is defined in Recommendation T.435. + +##### 6) *Application requirements* + +This parameter is defined in Recommendation T.435. + +#### 8.4.1.2 Bind-Result parameters + +The parameter of Abstract-Bind result for this complex service are used as follows (see Table 15): + +TABLE 15/T.191 + +**Use of Bind-Result parameters** + +| Parameter name | Class | +|-----------------------------------|-------| +| serverSelectedDtamProtocolVersion | m | +| odaApplicationCapabilities | m | +| serverSelectedDfrVersion | m | +| bilateralInformation | o | +| m Mandatory
o Optional | | + +##### 1) *server selected DTAM protocol version* + +"version-1" is specified in this complex service. + +##### 2) *ODA application capabilities* + +This "application capabilities" is defined in Recommendation T.435 and the following sub-parameters are used: + +###### i) oda document application profile; + +This parameter is defined in Recommendation T.432. + +###### ii) non-basic document characteristics; + +This parameter is defined in Recommendation T.432. + +##### 3) *Server Selected DFR version* + +This "application capabilities" is defined in Recommendation T.435. + +"version-2" is specified in this complex service. + +##### 4) *Bilateral information* + +###### i) server name; + +This parameter is defined in Recommendation T.435. + +###### ii) information; + +This parameter is defined in Recommendation T.435. + +#### 8.4.1.3 Bind-error parameters + +Bind-error parameters are defined in Recommendation T.435. + +### **8.4.2 Unbind service parameters** + +There are no argument or errors associated with the unbind-operation. + +### **8.4.3 The use of A-ABORT service parameters** + +The parameter of this service is defined in Recommendation T.435. + +### **8.4.4 The use of DTAM-DM Remote Document Manipulation Services and parameters** + +The use of the DTAM-DM remote manipulation service and parameters for the DFR/DTAM-DM communication module are identical to the use of the DTAM-DM communication module defined in 8.1.4. + +# **Annex A** + +## **Examples of remote manipulations using DTAM abstract service and ODA abstract interface** + +(This annex does not form an integral part of this Recommendation) + +Figure A.1 shows an example of the remote manipulation using DTAM abstract service and ODA abstract interface. + +![Diagram of the DM-CREATE abstract service showing the interaction between a Client and a Server. The Client sends a DM-CREATE message with parameters: destination: BasicManipulationObject, Position: ObjectPosition, and content: SEQUENCE OF ObjectContent. The Server responds with a tree structure labeled 'before manipulation' with nodes '3', '3_0', '3_1', and '3_2'. The Client then sends a DM-CREATE-Result message with parameter: fragment identifier: BasicLocationExpression. The Server responds with a tree structure labeled 'the result of manipulation' with nodes '3', '3_0', '3_1', '3_3', and '3_2', where node '3_3' is shaded. The diagram also includes detailed parameter lists for BasicManipulationObject, ObjectPosition, and ObjectContent.](8c348bf9c2c81b018017ae1d19506a9a_img.jpg) + +**Client** + +**Server** + +DM-CREATE + +- destination: BasicManipulationObject +- Position: ObjectPosition +- content: SEQUENCE OF ObjectContent + +specific logical structure + +content portion + +DM-CREATE → + +**BasicManipulationObject** + +- objectValue + - odaExpression *--BasicLocationExpression* + - constituent + - component + - object + - object + - Object-or-ClassIdentifier "3\_2" + +**ObjectPosition** + +before (1) + +**ObjectContent** + +- odaContent *--ConstituentType import from Recommendation T.413* +- manipulationDataElement + - Interchange-Data-Element *--Import from Recommendation T.415* + - logical object + - Logical Object Descriptor + - +- OdaContent *--ConstituentType import from Recommendation T.413* +- manipulationDataElement + - Interchange-Data-Element *-- Import from Recommendation T.415* + - content-portion + - Text-Unit + - + +DM-CREATE-Result + +- fragment identifier: BasicLocationExpression + +← DM-CREATE-Result + +**BasicManipulationObject** + +- objectValue + - odaExpression *--BasicLocationExpression* + - constituent + - component + - object + - object + - Object-or-ClassIdentifier "3\_3" + +T0824860-95/d04 + +Diagram of the DM-CREATE abstract service showing the interaction between a Client and a Server. The Client sends a DM-CREATE message with parameters: destination: BasicManipulationObject, Position: ObjectPosition, and content: SEQUENCE OF ObjectContent. The Server responds with a tree structure labeled 'before manipulation' with nodes '3', '3\_0', '3\_1', and '3\_2'. The Client then sends a DM-CREATE-Result message with parameter: fragment identifier: BasicLocationExpression. The Server responds with a tree structure labeled 'the result of manipulation' with nodes '3', '3\_0', '3\_1', '3\_3', and '3\_2', where node '3\_3' is shaded. The diagram also includes detailed parameter lists for BasicManipulationObject, ObjectPosition, and ObjectContent. + +FIGURE A.1/T.191 + +### **DM-CREATE abstract service** + +# Annex B + +## Some examples of use of parameters for the remote document manipulation + +(This annex does not form an integral part of this Recommendation) + +## B.1 DM-CREATE abstract service + +Normally the DM-CREATE abstract service is used to add the document fragments to an existing document. Exceptionally the DM-CREATE abstract service may be used to create a new object with empty content such as a specific logical structure under the restriction of generic structures. + +In this case, the DM-CREATE abstract service does not carry the document fragments. Therefore, the parameter "content" is not used. See Figures B.1 and B.2. + +![Diagram illustrating the normal use of the DM-CREATE abstract service. It shows a Client sending a DM-CREATE request to a Server. The request includes destination: '3_2', Position: before, and content: ObjectContent to be created. The Server's state is shown before and after manipulation. Before manipulation, the tree structure has root '3' with children '3_0', '3_1', and '3_2'. After manipulation, the tree structure has root '3' with children '3_0', '3_1', '3_3', and '3_2'. The new object '3_3' is highlighted, indicating it was created. A legend defines the symbols: a circle for Object Identifier, a rectangle for structure, and a shaded rectangle for content.](f0a97d0d3818a253c1d2a009966081b1_img.jpg) + +Client + +DM-CREATE + +destination: "3\_2" + +Position: before + +content: ObjectContent to be created + +Server + +"3" + +"3\_0" "3\_1" "3\_2" + +before manipulation + +Object Identifier + +"3\_0" + +structure + +content + +"3" + +"3\_0" "3\_1" "3\_3" "3\_2" + +the result of manipulation + +T0824870-95/d05 + +Diagram illustrating the normal use of the DM-CREATE abstract service. It shows a Client sending a DM-CREATE request to a Server. The request includes destination: '3\_2', Position: before, and content: ObjectContent to be created. The Server's state is shown before and after manipulation. Before manipulation, the tree structure has root '3' with children '3\_0', '3\_1', and '3\_2'. After manipulation, the tree structure has root '3' with children '3\_0', '3\_1', '3\_3', and '3\_2'. The new object '3\_3' is highlighted, indicating it was created. A legend defines the symbols: a circle for Object Identifier, a rectangle for structure, and a shaded rectangle for content. + +FIGURE B.1/T.191 + +Normal use of the DM-CREATE abstract service + +![Diagram illustrating the exceptional use of the DM-CREATE abstract service. It shows a Client sending a DM-CREATE request to a Server. The request specifies destination: '3_2', Position: before, and content: nul. The Server's state is shown 'before manipulation' and 'result of manipulation'. In the 'before' state, a root node '3' has three children: '3_0', '3_1', and '3_2'. Each child has an associated rectangular box below it. In the 'result of manipulation' state, the root node '3' has four children: '3_0', '3_1', '3_3', and '3_2'. The child '3_3' is shaded, and its associated box is also shaded. A box labeled 'Referring the restriction of generic structure' has arrows pointing to the transition between the two states.](11edb7fcedf09ac6a817f8d7b8c61eec_img.jpg) + +Client + +Server + +DM-CREATE +destination: "3\_2" +Position: before +content: nul + +before manipulation + +Referring the restriction of generic structure + +result of manipulation + +T0824880-95/d06 + +Diagram illustrating the exceptional use of the DM-CREATE abstract service. It shows a Client sending a DM-CREATE request to a Server. The request specifies destination: '3\_2', Position: before, and content: nul. The Server's state is shown 'before manipulation' and 'result of manipulation'. In the 'before' state, a root node '3' has three children: '3\_0', '3\_1', and '3\_2'. Each child has an associated rectangular box below it. In the 'result of manipulation' state, the root node '3' has four children: '3\_0', '3\_1', '3\_3', and '3\_2'. The child '3\_3' is shaded, and its associated box is also shaded. A box labeled 'Referring the restriction of generic structure' has arrows pointing to the transition between the two states. + +FIGURE B.2/T.191 +Exceptional use of the DM-CREATE abstract service + +## B.2 DM-DELETE abstract service + +Man machine interface provided by most of the editing tools or window systems supports a cut/copy/paste function. The Cut operation is used to delete document fragments and store them into the cut buffer. The Copy operation is used to store document fragment into the cut buffer without modifications of the original document. The Paste operation is used to extract document fragments from the cut buffer into the document. + +Cut operation corresponds to DM-DELETE abstract service. It is out of scope of this Recommendation whether deleted document fragments may be stored into the cut buffer or not. + +Figure B.3 illustrates the cut process. + +![Diagram illustrating the cut process. It shows a tree structure 'before manipulation' with root '3' and children '3_0', '3_1', and '3_2'. An arrow labeled 'cut "3_2"' points to the '3_2' node. Below, the 'result of manipulation' shows the tree with root '3' and children '3_0' and '3_1'. To the right, a 'Cut buffer' box contains the cut node '3_2'.](5d3455c6c2a37cb3aff761fedeb8644e_img.jpg) + +The diagram illustrates the cut process in a tree structure. It is divided into three main parts: the initial state, the result of manipulation, and the cut buffer. + +- before manipulation:** A tree structure with a root node labeled "3". The root has three children: "3\_0", "3\_1", and "3\_2". Each child node is represented by a circle, and each has a corresponding square box below it. +- cut "3\_2":** An arrow points from the "3\_2" node in the initial state to the cut buffer. +- result of manipulation:** A tree structure showing the result after the cut operation. The root node is still "3", but it now only has two children: "3\_0" and "3\_1". +- Cut buffer:** A rectangular box containing the cut node "3\_2" (a circle with a square below it). + +Diagram illustrating the cut process. It shows a tree structure 'before manipulation' with root '3' and children '3\_0', '3\_1', and '3\_2'. An arrow labeled 'cut "3\_2"' points to the '3\_2' node. Below, the 'result of manipulation' shows the tree with root '3' and children '3\_0' and '3\_1'. To the right, a 'Cut buffer' box contains the cut node '3\_2'. + +T0824890-95/d07 + +FIGURE B.3/T.191 +An example of delete operation + +## B.3 DM-COPY abstract service + +The Copy and Paste operation may be replaced by the DM-COPY abstract service. To be precise, if the client requires copy operation which is used to extract the document fragments from the document store at the remote server and to put into the remote cut buffer, then the only service parameter "source" is specified. If DTAM user wishes to make a paste operation which is used to extract the document fragment from the cut buffer at the remote server and to put into the document at the remote server, then both, service parameter "destination" and "position" should be specified. + +Figure B.4 illustrates copy process using DM-COPY abstract service. + +![Diagram illustrating the copy process using DM-COPY abstract service. The diagram shows a hierarchical tree structure representing a data structure. At the top is a circle node labeled '3'. Below it are three circle nodes labeled '3_0', '3_1', and '3_2', each connected to a square node below it. An arrow labeled 'DM-COPY source : "3_2"' points to the '3_2' node. A vertical arrow points from the '3_2' node down to a circle node labeled '3'. Below this '3' node are three circle nodes labeled '3_0', '3_1', and '3_2', each connected to a square node below it. The text 'result of manipulation' is placed to the right of these bottom nodes. To the right of the main structure is a large rectangle labeled 'Cut buffer'. Inside the rectangle is a circle node labeled '3_2' connected to a square node below it. An arrow points from the '3_2' node in the top structure to the '3_2' node in the 'Cut buffer'.](d9843ac5dfc4bbe9e4d21b8898723b5e_img.jpg) + +Server + +DM-COPY +source : "3\_2" + +"3" + +"3\_0" "3\_1" "3\_2" + +"3" + +"3\_0" "3\_1" "3\_2" + +result of manipulation + +Cut buffer + +T0824900-95/d08 + +Diagram illustrating the copy process using DM-COPY abstract service. The diagram shows a hierarchical tree structure representing a data structure. At the top is a circle node labeled '3'. Below it are three circle nodes labeled '3\_0', '3\_1', and '3\_2', each connected to a square node below it. An arrow labeled 'DM-COPY source : "3\_2"' points to the '3\_2' node. A vertical arrow points from the '3\_2' node down to a circle node labeled '3'. Below this '3' node are three circle nodes labeled '3\_0', '3\_1', and '3\_2', each connected to a square node below it. The text 'result of manipulation' is placed to the right of these bottom nodes. To the right of the main structure is a large rectangle labeled 'Cut buffer'. Inside the rectangle is a circle node labeled '3\_2' connected to a square node below it. An arrow points from the '3\_2' node in the top structure to the '3\_2' node in the 'Cut buffer'. + +FIGURE B.4/T.191 +An example of copy operation + +Figure B.5 illustrates copy process using the DM-COPY abstract service. + +![Diagram illustrating the copy process using the DM-COPY abstract service. The diagram shows a 'Server' node at the top, which is a circle labeled '3'. Below it, three circles labeled '3_0', '3_1', and '3_2' are connected to the server. Each of these circles is connected to a square node below it. An arrow labeled 'DM-COPY' with 'destination : "3_2"' and 'position : before' points to the '3_2' circle. Below the '3_0', '3_1', and '3_2' circles, there is a single circle labeled '3'. An arrow points from this '3' circle to a new set of four circles labeled '3_0', '3_1', '3_3', and '3_2'. Each of these circles is connected to a square node below it. The '3_3' circle and its corresponding square node are shaded gray. To the right of this set of circles is the text 'result of manipulation'. To the right of the diagram is a box labeled 'Cut buffer' containing a circle labeled '3_3' connected to a square node below it. An arrow points from the 'Cut buffer' box to the '3' circle in the middle of the diagram. The text 'T0824910-95/d09' is at the bottom right.](c76da2d73c064464051d1583fd80bb6b_img.jpg) + +Diagram illustrating the copy process using the DM-COPY abstract service. The diagram shows a 'Server' node at the top, which is a circle labeled '3'. Below it, three circles labeled '3\_0', '3\_1', and '3\_2' are connected to the server. Each of these circles is connected to a square node below it. An arrow labeled 'DM-COPY' with 'destination : "3\_2"' and 'position : before' points to the '3\_2' circle. Below the '3\_0', '3\_1', and '3\_2' circles, there is a single circle labeled '3'. An arrow points from this '3' circle to a new set of four circles labeled '3\_0', '3\_1', '3\_3', and '3\_2'. Each of these circles is connected to a square node below it. The '3\_3' circle and its corresponding square node are shaded gray. To the right of this set of circles is the text 'result of manipulation'. To the right of the diagram is a box labeled 'Cut buffer' containing a circle labeled '3\_3' connected to a square node below it. An arrow points from the 'Cut buffer' box to the '3' circle in the middle of the diagram. The text 'T0824910-95/d09' is at the bottom right. + +FIGURE B.5/T.191 +An example of copy operation + +# Annex C + +## Error Handling of manipulation service by CDH application + +(This annex does not form an integral part of this Recommendation) + +### Rollback mechanism + +In the case of Joint Synchronous Editing, each client has the same document process. Some systems may issue the manipulation service and manipulate the local document before receiving the confirmation of the manipulation service from the remote client. Therefore, if the requester of the manipulation has successfully manipulated locally and the responder fails to manipulate the document at the responder, then the requester undoes the last manipulation in order to keep consistency between local and remote document. + +If some errors are detected by the remote server, the following recovery mechanisms are specified. + +### – Mechanism 1 + +The terminal does not support error handling of the manipulation service. + +### – *Mechanism 2* + +If an error is detected by the terminal, then the terminal aborts DTAM association. In this case, the detector of an error should abort the DTAM association. + +#### – *Mechanism 3* + +If an error is detected by the terminal, then the terminal discards the series of manipulations after the last saved document. In this case, the detector of an error should discard the series of manipulations. + +If a fatal error is detected by the terminal, the terminal aborts the DTAM association. In this case, the detector of an error should abort the DTAM association. + +#### – *Mechanism 4* + +If a recoverable error is detected, the terminal retries to issue the same manipulation service as the last one. + +If it has been clear that an error is unrecoverable after some retry procedures, or serious errors are detected, then the terminal discards the series of manipulations after the last saved document. In this case, the detector of an error should discard the series of manipulations. + +If a fatal error is detected by the terminal, the terminal aborts the DTAM association. In this case, the detector of an error should abort the DTAM association. + +Figure C.1 illustrates the flow of mechanism 4. + +![Flowchart of Mechanism 4 showing error handling logic.](f732d3320afe06d979aabbd366184254_img.jpg) + +``` + +graph TD + START([START]) --> Recoverable{recoverable error} + Recoverable -- yes --> RetryOut{retry out} + Recoverable -- no --> FatalError{fatal error} + RetryOut -- no --> FatalError + RetryOut -- yes --> RetryManip[retry manipulation] + FatalError -- no --> DiscardManip[discard manipulation] + FatalError -- yes --> AbortAssoc[abort association] + DiscardManip --> END([END]) + AbortAssoc --> END + RetryManip --> END + +``` + +The flowchart illustrates the logic for Mechanism 4. It begins with a 'START' terminal, leading to a decision diamond 'recoverable error'. If 'yes', it proceeds to another decision diamond 'retry out'. If 'retry out' is 'no', it goes to a third decision diamond 'fatal error'. If 'fatal error' is 'no', it leads to a process box 'discard manipulation'. If 'fatal error' is 'yes', it leads to a process box 'abort association'. If 'retry out' is 'yes', it leads to a process box 'retry manipulation'. All three process boxes ('discard manipulation', 'abort association', and 'retry manipulation') converge into a single path leading to the 'END' terminal. + +Flowchart of Mechanism 4 showing error handling logic. + +T0824920-95/d10 + +FIGURE C.1/T.191 +Flow of mechanism 4 + +Negotiation mechanisms for those error handlings are for further study. \ No newline at end of file diff --git a/marked/T/T-REC-T.24-201511-I_PDF-E/raw.md b/marked/T/T-REC-T.24-201511-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..46a22c532735d7a761c82a53f77a192198729197 --- /dev/null +++ b/marked/T/T-REC-T.24-201511-I_PDF-E/raw.md @@ -0,0 +1,1435 @@ + + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## T.24 + +(11/2015) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES + +Still-image compression – Test charts + +# --- **Standardized digitized image set** + +Recommendation ITU-T T.24 + +## ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES** + +| | | +|-----------------------------------------------------|------------------| +| Facsimile – Framework | T.0–T.19 | +| Still-image compression – Test charts | T.20–T.29 | +| Facsimile – Group 3 protocols | T.30–T.39 | +| Colour representation | T.40–T.49 | +| Character coding | T.50–T.59 | +| Facsimile – Group 4 protocols | T.60–T.69 | +| Telematic services – Framework | T.70–T.79 | +| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89 | +| Telematic services – ISDN Terminals and protocols | T.90–T.99 | +| Videotext – Framework | T.100–T.109 | +| Data protocols for multimedia conferencing | T.120–T.149 | +| Telewriting | T.150–T.159 | +| Multimedia and hypermedia framework | T.170–T.189 | +| Cooperative document handling | T.190–T.199 | +| Telematic services – Interworking | T.300–T.399 | +| Open document architecture | T.400–T.429 | +| Document transfer and manipulation | T.430–T.449 | +| Document application profile | T.500–T.509 | +| Communication application profile | T.510–T.559 | +| Telematic services – Equipment characteristics | T.560–T.649 | +| Still-image compression – JPEG 2000 | T.800–T.829 | +| Still-image compression JPEG XR | T.830–T.849 | +| Still-image compression – JPEG-1 extensions | T.850–T.899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T T.24 + +# Standardized digitized image set + +## Summary + +The images in Recommendation ITU-T T.24 include the original eight "ITU-T reference images" (the ITU-T was formerly known as the CCITT and so these images were referred to for years as the "CCITT images"), two bi-level test charts, a grayscale test chart, various screened half-tone images, electronically dithered images, computer-generated images, grayscale images and colour images. The purpose of this image set is to provide a consistent baseline for future work; for example, results of compression algorithm experiments and image quality tests can be compared by a broad range of users, knowing that the input image data is identical. + +The specimens reproduced inside the Recommendation in the figures are given for illustration purposes and are not suitable for measurements. + +The 3rd edition to Recommendation ITU-T T.24 is the consolidated version of Recommendation ITU-T T.24 (1998) and Corrigendum 1 (that clarifies text in Table 1 with respect to the file sizes of reference test images on a companion CD-ROM). Amendment 1 (2000) was withdrawn in 2016/02 due to the unavailability of the 1200 dpi version of the ITU-T reference images there prescribed. + +This Recommendation includes an electronic attachment available from . + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|--------------------------|------------|-------------|------------------------------------| +| 1.0 | ITU-T T.24 | 1994-11-11 | 8 | 11.1002/1000/2510 | +| 2.0 | ITU-T T.24 | 1998-06-18 | 8 | 11.1002/1000/4390 | +| 2.1 | ITU-T T.24 (1998) Amd. 1 | 2000-02-10 | 8 | 11.1002/1000/4838 | +| 2.2 | ITU-T T.24 (1998) Cor. 1 | 2015-11-29 | 16 | 11.1002/1000/12680 | +| 3.0 | ITU-T T.24 | 2015-11-29 | 16 | 11.1002/1000/12981 | + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2016 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | | Page | +|---|-----------------------------------------------------------------------------------------|------| +| 1 | Scope..... | 1 | +| 2 | References..... | 1 | +| 3 | Definitions ..... | 1 | +| | 3.1 Terms defined elsewhere..... | 1 | +| | 3.2 Terms defined in this Recommendation..... | 1 | +| 4 | Abbreviations and acronyms ..... | 1 | +| 5 | Conventions ..... | 2 | +| 6 | Description of the standardized digitized image set..... | 2 | +| | 6.1 Eight ITU-T reference images..... | 2 | +| | 6.2 ITU-T T.22 test chart No. 4 – Black-white facsimile test chart BW01..... | 12 | +| | 6.3 Legibility test chart..... | 14 | +| | 6.4 Bi-level half-tones ..... | 16 | +| | 6.5 ITU-T T.22 test chart No. 5 – Continuous tone test chart CT01..... | 21 | +| | 6.6 House with trees and house with sky ..... | 22 | +| | 6.7 ITU-T T.23 test chart No. 6 – 4-Colour printing facsimile test chart
4CP01 ..... | 23 | +| | 6.8 CCIR images ..... | 26 | +| | 6.9 Colour images (CMYK colour space)..... | 27 | +| | 6.10 Colour images (RGB colour space)..... | 31 | +| | 6.11 Fingerprint and medical images (Grayscale)..... | 35 | +| | 6.12 Line drawing images ..... | 37 | +| | 6.13 Fine arts images..... | 40 | +| | 6.14 Low-contrast grayscale images ..... | 42 | +| | Appendix I – Black/white pixel counts..... | 51 | +| | Appendix II – Sun Raster image format ..... | 53 | +| | Bibliography..... | 54 | + +## Included electronic files + +Available from : + +### CD-ROM 1: + +Eight ITU-T reference images, ITU-T T.22 test chart No. 4, Legibility test chart, Bi-level half tones, ITU-T T.22 test chart No. 5, Houses, T.23 test chart No. 6. + +### CD-ROM 2: + +CCIR images, CMYK colour images, RGB colour images, Fingerprint and medical grayscale images, Line drawing images, Fine arts images, Low-contrast grayscale images. + +# Introduction + +Test images have played an important role throughout the development of Group 3 and Group 4 facsimile. This Recommendation has been prepared with the goal of providing a standard set of images1 to facsimile experimenters. The set includes images that have been used over the years plus new images that are applicable for grayscale and colour. The standard set of images will provide a consistent baseline for further work; for example, results of compression algorithm experiments and image quality tests can be compared by a broad range of users, knowing that the input image data is identical. The set of images, stored on a compact disk read only memory (CD-ROM), is available from the ITU. + +--- + +1 The test images reproduced in this Recommendation are not suitable for the tests. + +# Recommendation ITU-T T.24 + +# Standardized digitized image set + +## 1 Scope + +The development of image compression algorithms can be facilitated by performance comparisons to reference images and algorithms. + +This Recommendation provides a reference image set that is to be used as a consistent baseline for future image compression work. For example, results of compression algorithm experiments and image quality tests can be compared by a broad range of users, knowing that the input image data is identical. + +The images in this Recommendation include the original eight "ITU-T reference images" (also known as the "CCITT images"), two bi-level test charts, a grayscale test chart, various screened half-tone images, electronically dithered images, computer-generated images, grayscale images and colour images. + +The specimens reproduced in the figures inside this Recommendation are given for illustration purposes and are not suitable for measurements. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[ITU-T T.22] Recommendation ITU-T T.22 (1993), *Standardized test charts for document facsimile transmissions*. + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +None. + +### 3.2 Terms defined in this Recommendation + +This Recommendation defines the following term: + +**3.2.1 YUV:** YUV (also known as YCbCr) colour model represents the human perception of colour more closely than the red, green and blue (RGB) colour component model by emphasizing the higher sensitivity of human vision to luminance (Y) than to colour information (U or Cb and Y or Cr). This is done by representing the luminance with a higher bit resolution than Cb and Cr. The relationship between YUV and RGB is defined in clause 2.5 of [b-ITU-R BT.601]. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +CCIR International Radio Consultative Committee (now ITU-R) + +| | | +|-------|--------------------------------------------------------------------------| +| CCITT | International Telegraph and Telephone Consultative Committee (now ITU-T) | +| CMYK | Cyan, Magenta, Yellow and Key (black) | +| JPEG | Joint Photographic Experts Group | +| RGB | Red Green Blue | +| SCID | Standard Colour Image Data | + +## 5 Conventions + +None. + +## 6 Description of the standardized digitized image set + +The following sub-clauses describe the various images of the ITU-T T.24 standardized digitized image set2 that are found in the electronic attachment to this Recommendation, as well as on the ITU-T Test Signal Database at . + +NOTE – The test images reproduced in the main body of this Recommendation are not suitable for tests. + +### 6.1 Eight ITU-T reference images + +This image set is derived from the eight ITU-T reference images (formerly known as the "CCITT images"). The eight pages were originally digitized by the French Administration as 200 pels per 25.4 mm and were used in the Group 3 facsimile algorithm selection process, completed in 1980. The digitized images herein were produced from original-quality copies of the eight ITU-T reference images, made at the time that the Group 3 compression algorithm studies were being conducted. All of the pages are A4 size, which is 210 mm wide by 297 mm long. The resolutions selected for the scanning process (200, 300, 400 and 600 pels per 25.4 mm) were based on those specified in the Group 3 and Group 4 Recommendations (200, 300 and 400 pels per 25.4 mm) plus 600 pels per 25.4 mm. + +The number of pels per line is determined from the resolution and the width of the page. For the A4 page width of 210 mm, a 200 pels per 25.4 mm scan gives 1654 pels per line. The 1654 pel width is not a convenient number for computer-based processing (not divisible by 8). To correct this condition, the charts were scanned to produce the nominal pels per line and lines per image shown in the Group 3 and Group 4 Recommendations. This means that the pages were centred and overscanned. (The chart itself is 210 mm wide, but the scan line is 219.46 mm wide.) The total number of bytes required to store each of the images, as a function of resolution (or sampling density), is shown in Table 1. The eight ITU reference documents are illustrated in Figures 1 through 8. + +--- + +2 The specimens reproduced in the figures of this Recommendation are given for illustration purposes and are not suitable for measurements + +**Table 1 – ITU reference documents** + +| Figure number | Image | Description | Dimensions | | | | Resolution (pixels/inch) (1 bit/pixel) | Size (MBytes) | | | +|---------------|----------------|------------------------|------------|--------|--------|--------|----------------------------------------|---------------|--|--| +| | | | Pixels | | Inches | | | | | | +| | | | Width | Height | Width | Height | | | | | +| Figure 1 | Document No. 1 | English letter | 1728 | 2339 | 8.64 | 11.70 | 200 | 0.48 | | | +| | | | 2592 | 3508 | 8.64 | 11.69 | 300 | 1.08 | | | +| | | | 3456 | 4677 | 8.64 | 11.69 | 400 | 1.93 | | | +| | | | 5184 | 7016 | 8.64 | 11.69 | 600 | 4.34 | | | +| Figure 2 | Document No. 2 | Circuit drawing | 1728 | 2339 | 8.64 | 11.70 | 200 | 0.48 | | | +| | | | 2592 | 3508 | 8.64 | 11.69 | 300 | 1.08 | | | +| | | | 3456 | 4677 | 8.64 | 11.69 | 400 | 1.93 | | | +| | | | 5184 | 7016 | 8.64 | 11.69 | 600 | 4.34 | | | +| Figure 3 | Document No. 3 | French invoice | 1728 | 2339 | 8.64 | 11.70 | 200 | 0.48 | | | +| | | | 2592 | 3508 | 8.64 | 11.69 | 300 | 1.08 | | | +| | | | 3456 | 4677 | 8.64 | 11.69 | 400 | 1.93 | | | +| | | | 5184 | 7016 | 8.64 | 11.69 | 600 | 4.34 | | | +| Figure 4 | Document No. 4 | French text | 1728 | 2339 | 8.64 | 11.70 | 200 | 0.48 | | | +| | | | 2592 | 3508 | 8.64 | 11.69 | 300 | 1.08 | | | +| | | | 3456 | 4677 | 8.64 | 11.69 | 400 | 1.93 | | | +| | | | 5184 | 7016 | 8.64 | 11.69 | 600 | 4.34 | | | +| Figure 5 | Document No. 5 | French text figures | 1728 | 2339 | 8.64 | 11.70 | 200 | 0.48 | | | +| | | | 2592 | 3508 | 8.64 | 11.69 | 300 | 1.08 | | | +| | | | 3456 | 4677 | 8.64 | 11.69 | 400 | 1.93 | | | +| | | | 5184 | 7016 | 8.64 | 11.69 | 600 | 4.34 | | | +| Figure 6 | Document No. 6 | French chart | 1728 | 2339 | 8.64 | 11.70 | 200 | 0.48 | | | +| | | | 2592 | 3508 | 8.64 | 11.69 | 300 | 1.08 | | | +| | | | 3456 | 4677 | 8.64 | 11.69 | 400 | 1.93 | | | +| | | | 5184 | 7016 | 8.64 | 11.69 | 600 | 4.34 | | | +| Figure 7 | Document No. 7 | Kanji | 1728 | 2339 | 8.64 | 11.70 | 200 | 0.48 | | | +| | | | 2592 | 3508 | 8.64 | 11.69 | 300 | 1.08 | | | +| | | | 3456 | 4677 | 8.64 | 11.69 | 400 | 1.93 | | | +| | | | 5184 | 7016 | 8.64 | 11.69 | 600 | 4.34 | | | +| Figure 8 | Document No. 8 | Handwritten memorandum | 1728 | 2339 | 8.64 | 11.70 | 200 | 0.48 | | | +| | | | 2592 | 3508 | 8.64 | 11.69 | 300 | 1.08 | | | +| | | | 3456 | 4677 | 8.64 | 11.69 | 400 | 1.93 | | | +| | | | 5184 | 7016 | 8.64 | 11.69 | 600 | 4.34 | | | + +NOTE 1 – The users of the Recommendation may freely reproduce Figures 1 to 8 to check the quality of document facsimile transmission. + +NOTE 2 – The values in the Size column are the uncompressed files sizes. The corresponding files on the CD-ROM are compressed. + +![Circular logo or stamp at the top center of the page.](e7cb11f042fc58088dff4b6d9306845e_img.jpg) + +Circular logo or stamp at the top center of the page. + +#### THE SLEREXE COMPANY LIMITED + +SAPORS LANE - BOOLE - DORSET - BH 25 8 ER + +TELEPHONE BOOLE (945 13) 51617 - TELEX 123456 + +Our Ref. 350/PJC/EAC + +18th January, 1972. + +Dr. P.N. Cundall, +Mining Surveys Ltd., +Holroyd Road, +Reading, +Berks. + +Dear Pete, + +Permit me to introduce you to the facility of facsimile transmission. + +In facsimile a photocell is caused to perform a raster scan over the subject copy. The variations of print density on the document cause the photocell to generate an analogous electrical video signal. This signal is used to modulate a carrier, which is transmitted to a remote destination over a radio or cable communications link. + +At the remote terminal, demodulation reconstructs the video signal, which is used to modulate the density of print produced by a printing device. This device is scanning in a raster scan synchronised with that at the transmitting terminal. As a result, a facsimile copy of the subject document is produced. + +Probably you have uses for this facility in your organisation. + +Yours sincerely, + +*Phil.* + +P.J. CROSS +Group Leader - Facsimile Research + +Registered in England: No. 2038 +Registered Office: 60 Vicars Lane, Ilford, Essex. + +**Figure 1 – Document No. 1 – English letter** + +![Hand-drawn circuit diagram of a current driver circuit. The circuit includes a primary circuit with a 180Ω resistor and a 100pF capacitor in parallel, connected to a 32μF capacitor and a 75Ω resistor. A transistor is connected to this network. The transistor's base is connected to a 75Ω resistor and a 10Ω resistor. The emitter is grounded. The collector is connected to a 75Ω resistor, a 10Ω resistor, and a 32μF capacitor. The 32μF capacitor is connected to a 100Ω resistor and a 12Ω resistor. The 100Ω resistor is connected to a diode and a coil labeled 'Primaries of pulse transformers in H.V. switches'. The 12Ω resistor is connected to a voltage source Vs. The diode is connected to a +V source. The 10Ω resistor is connected to ground.](cfef993dcc8fb513de79eb1f93cf26ae_img.jpg) + +Primary circuit. + +32μF + +100pF + +180Ω + +75Ω + +10Ω + +75Ω + +32μF + +100Ω + +12Ω + +Vs + +Primaries of pulse transformers in H.V. switches + ++V + +Hand-drawn circuit diagram of a current driver circuit. The circuit includes a primary circuit with a 180Ω resistor and a 100pF capacitor in parallel, connected to a 32μF capacitor and a 75Ω resistor. A transistor is connected to this network. The transistor's base is connected to a 75Ω resistor and a 10Ω resistor. The emitter is grounded. The collector is connected to a 75Ω resistor, a 10Ω resistor, and a 32μF capacitor. The 32μF capacitor is connected to a 100Ω resistor and a 12Ω resistor. The 100Ω resistor is connected to a diode and a coil labeled 'Primaries of pulse transformers in H.V. switches'. The 12Ω resistor is connected to a voltage source Vs. The diode is connected to a +V source. The 10Ω resistor is connected to ground. + +*This is current driver circuit.* + +*Phil.* + +22-9-71 + +Figure 2 – Document No. 2 – Circuit drawing + + + +L'ordre de lancement et de réalisation des applications fait l'objet de décisions au plus haut niveau de la Direction Générale des Télécommunications. Il n'est certes pas question de construire ce système intégré "en bloc" mais bien au contraire de procéder par étapes, par paliers successifs. Certaines applications, dont la rentabilité ne pourra être assurée, ne seront pas entreprises. Actuellement, sur trente applications qui ont pu être globalement définies, six en sont au stade de l'exploitation, six autres se sont vu donner la priorité pour leur réalisation. + +Chaque application est confiée à un "chef de projet", responsable successivement de sa conception, de son analyse-programmation et de sa mise en oeuvre dans une région-pilote. La généralisation ultérieure de l'application réalisée dans cette région-pilote dépend des résultats obtenus et fait l'objet d'une décision de la Direction Générale. Néanmoins, le chef de projet doit dès le départ considérer que son activité a une vocation nationale donc refuser tout particularisme régional. Il est aidé d'une équipe d'analystes-programmeurs et entouré d'un "groupe de conception" chargé de rédiger le document de "définition des objectifs globaux" puis le "cahier des charges" de l'application, qui sont adressés pour avis à tous les services utilisateurs potentiels et aux chefs de projet des autres applications. Le groupe de conception comprend 6 à 10 personnes représentant les services les plus divers concernés par le projet, et comporte obligatoirement un bon analyste attaché à l'application. + +#### II - L'IMPLANTATION GEOGRAPHIQUE D'UN RESEAU INFORMATIQUE PERFORMANT + +L'organisation de l'entreprise française des télécommunications repose sur l'existence de 20 régions. Des calculateurs ont été implantés dans le passé au moins dans toutes les plus importantes. On trouve ainsi des machines Bull Gamma 30 à Lyon et Marseille, des GE 425 à Lille, Bordeaux, Toulouse et Montpellier, un GE 437 à Massy, enfin quelques machines Bull 300 TI à programmes câblés étaient récemment ou sont encore en service dans les régions de Nancy, Nantes, Limoges, Poitiers et Rouen ; ce parc est essentiellement utilisé pour la comptabilité téléphonique. + +A l'avenir, si la plupart des fichiers nécessaires aux applications décrites plus haut peuvent être gérés en temps différé, un certain nombre d'entre eux devront nécessairement être accessibles, voire mis à jour en temps réel : parmi ces derniers le fichier commercial des abonnés, le fichier des renseignements, le fichier des circuits, le fichier technique des abonnés contiendront des quantités considérables d'informations. + +Le volume total de caractères à gérer en phase finale sur un ordinateur ayant en charge quelques 500 000 abonnés a été estimé à un milliard de caractères au moins. Au moins le tiers des données seront concernées par des traitements en temps réel. + +Aucun des calculateurs énumérés plus haut ne permettait d'envisager de tels traitements. + +L'intégration progressive de toutes les applications suppose la création d'un support commun pour toutes les informations, une véritable "Banque de données", répartie sur des moyens de traitement nationaux et régionaux, et qui devra rester alimentée, mise à jour en permanence, à partir de la base de l'entreprise, c'est-à-dire les chantiers, les magasins, les guichets des services d'abonnement, les services de personnel etc. + +L'étude des différents fichiers à constituer a donc permis de définir les principales caractéristiques du réseau d'ordinateurs nouveaux à mettre en place pour aborder la réalisation du système informatif. L'obligation de faire appel à des ordinateurs de troisième génération, très puissants et dotés de volumineuses mémoires de masse, a conduit à en réduire substantiellement le nombre. + +L'implantation de sept centres de calcul interrégionaux constituera un compromis entre : d'une part le désir de réduire le coût économique de l'ensemble, de faciliter la coordination des équipes d'informaticiens ; et d'autre part le refus de créer des centres trop importants difficiles à gérer et à diriger, et posant des problèmes délicats de sécurité. Le regroupement des traitements relatifs à plusieurs régions sur chacun de ces sept centres permettra de leur donner une taille relativement homogène. Chaque centre "gèrera" environ un million d'abonnés à la fin du VIème Plan. + +La mise en place de ces centres a débuté au début de l'année 1971 : un ordinateur IRIS 50 de la Compagnie Internationale pour l'Informatique a été installé à Toulouse en février ; la même machine vient d'être mise en service au centre de calcul interrégional de Bordeaux. + +Photo n° 1 - Document très dense lettre 1,5mm de haut - +Restitution photo n° 9 + +Figure 4 – Document No. 4 – French text + +Cela est d'autant plus valable que $T\Delta f$ est plus grand. A cet égard la figure 2 représente la vraie courbe donnant $|\phi(f)|$ en fonction de $f$ pour les valeurs numériques indiquées page précédente. + +![Figure 2: A graph showing the magnitude of the phase |phi(f)| as a function of frequency f. The curve is a sinc function centered at f_0 + Delta f / 2. The x-axis is labeled with f_0 and f_0 + Delta f. The y-axis is labeled with (T/Delta f)^1/2. A horizontal dashed line is drawn at the peak of the curve, labeled T*Delta f = 60.](0b8b087a7baa471015d3ffeaa43d9a6c_img.jpg) + +Figure 2: A graph showing the magnitude of the phase |phi(f)| as a function of frequency f. The curve is a sinc function centered at f\_0 + Delta f / 2. The x-axis is labeled with f\_0 and f\_0 + Delta f. The y-axis is labeled with (T/Delta f)^1/2. A horizontal dashed line is drawn at the peak of the curve, labeled T\*Delta f = 60. + +FIG. 2 + +Dans ce cas, le filtre adapté pourra être constitué, conformément à la figure 3, par la cascade : + +— d'un filtre passe-bande de transfert unité pour $f_0 \leq f \leq f_0 + \Delta f$ et de transfert quasi nul pour $f < f_0$ et $f > f_0 + \Delta f$ , filtre ne modifiant pas la phase des composants le traversant ; + +![Figure 3: A block diagram showing a cascade of two components. The first component is a bandpass filter represented by a rectangle with a trapezoidal shape inside. The second component is a dispersive delay line (L.A.R.) represented by a rectangle labeled 'L.A.R.'.](a26e142d3df5bef41a84a9dd099d7825_img.jpg) + +Figure 3: A block diagram showing a cascade of two components. The first component is a bandpass filter represented by a rectangle with a trapezoidal shape inside. The second component is a dispersive delay line (L.A.R.) represented by a rectangle labeled 'L.A.R.'. + +FIG. 3 + +— filtre suivi d'une ligne à retard (LAR) dispersive ayant un temps de propagation de groupe $T_R$ décroissant linéairement avec la fréquence $f$ suivant l'expression : + +$$T_R = T_0 + (f_0 - f) \frac{T}{\Delta f} \quad (\text{avec } T_0 > T)$$ + +(voir fig. 4). + +![Figure 4: A graph showing the group delay T_R as a function of frequency f. The curve is a straight line with a negative slope. The y-axis is labeled T_R and has two points marked: T_0 and T_0 - T. The x-axis is labeled f and has two points marked: f_0 and f_0 + Delta f. Dashed lines connect the points on the curve to the axes.](70f5f44cb855bbb0c203c00187b2113e_img.jpg) + +Figure 4: A graph showing the group delay T\_R as a function of frequency f. The curve is a straight line with a negative slope. The y-axis is labeled T\_R and has two points marked: T\_0 and T\_0 - T. The x-axis is labeled f and has two points marked: f\_0 and f\_0 + Delta f. Dashed lines connect the points on the curve to the axes. + +FIG. 4 + +telle ligne à retard est donnée par : + +$$\varphi = -2\pi \int_0^f T_R df$$ + +$$\varphi = -2\pi \left[ T_0 + \frac{f_0 T}{\Delta f} \right] f + \pi \frac{T}{\Delta f} f^2$$ + +Et cette phase est bien l'opposé de $\phi(f)$ , + +à un déphasage constant près (sans importance) et à un retard $T_0$ près (inévitables). + +Un signal utile $S(t)$ traversant un tel filtre adapté donne à la sortie (à un retard $T_0$ près et à un déphasage près de la porteuse) un signal dont la transformée de Fourier est réelle, constante entre $f_0$ et $f_0 + \Delta f$ , et nulle de part et d'autre de $f_0$ et de $f_0 + \Delta f$ , c'est-à-dire un signal de fréquence porteuse $f_0 + \Delta f/2$ et dont l'enveloppe a la forme indiquée à la figure 5, où l'on a représenté simultanément le signal $S(t)$ et le signal $S_1(t)$ correspondant obtenu à la sortie du filtre adapté. On comprend le nom de récepteur à compression d'impulsion donné à ce genre de filtre adapté : la « largeur » (à 3 dB) du signal comprimé étant égale à $1/\Delta f$ , le rapport de compression est de $\frac{T}{1/\Delta f} = T\Delta f$ + +![Figure 5: A graph showing the signal S(t) and its envelope. The x-axis is labeled t (μs) and has marks at 5 and 10. The y-axis is labeled S(t). The signal S(t) is a narrow pulse centered at t = 10 μs. The envelope of S(t) is a wider pulse centered at the same time. The width of the envelope is labeled as 0,2 μs. Below the graph, the following values are listed: T_0 = 14 μs, Delta f = 5 MHz, T = 12 μs.](be3a196d8ffbb3465e9673afa748639f_img.jpg) + +Figure 5: A graph showing the signal S(t) and its envelope. The x-axis is labeled t (μs) and has marks at 5 and 10. The y-axis is labeled S(t). The signal S(t) is a narrow pulse centered at t = 10 μs. The envelope of S(t) is a wider pulse centered at the same time. The width of the envelope is labeled as 0,2 μs. Below the graph, the following values are listed: T\_0 = 14 μs, Delta f = 5 MHz, T = 12 μs. + +FIG. 5 + +On saisit physiquement le phénomène de compression en réalisant que lorsque le signal $S(t)$ entre dans la ligne à retard (LAR) la fréquence qui entre la première à l'instant 0 est la fréquence basse $f_0$ , qui met un temps $T_0$ pour traverser. La fréquence $f$ entre à l'instant $t = (f - f_0) \frac{T}{\Delta f}$ et elle met un temps + +$T_0 - (f - f_0) \frac{T}{\Delta f}$ pour traverser, ce qui la fait ressortir à l'instant $T_0$ également. Ainsi donc, le signal $S(t)$ + +Figure 5 – Document No. 5 – French text figures + +![Figure 3: A graph showing the relationship between D (dB) and Q (dB) for different values of G_n. The y-axis (D) ranges from 5 to 40 dB, and the x-axis (Q) ranges from 5 to 35 dB. Three main curves are shown for G_n = infinity, 35 dB, and 25 dB. Data points are plotted for G_n = infinity (x), G_n = 35 dB (square), and G_n = 25 dB (circle). Some points have vertical error bars. A dashed line indicates the 95% confidence limits. The legend specifies symbols for ascending and descending parts of the curves and adapted curves from ITU-T recommendations [10] and [23].](177e8bc1c595b7fe3461d9919f87e044_img.jpg) + +dB +D + $G_n$ + +40 + +35 + +30 + +25 + +20 + +15 + +10 + +5 + +5 10 15 20 25 30 35 dB Q + +CCITT 5337 + +Limites de confiance à 95% + +Courbes adaptées $G_n$ (essais subjectifs) pour + +$G_n = \infty$ $G_n = 35\text{dB}$ $G_n = 25\text{dB}$ + +[10] $\times$ $\square$ $\underline{\circ}$ + +[23] + +Points calculés $D(Q, G_n)$ pour + +$G_n = \infty$ $G_n = 25$ $G_n = 35\text{ dB}$ + +● ■ Δ - dans la partie montante + +x ⊕ + - dans la partie descendante + +Courbes $D(Q, G_n)$ + +Figure 3: A graph showing the relationship between D (dB) and Q (dB) for different values of G\_n. The y-axis (D) ranges from 5 to 40 dB, and the x-axis (Q) ranges from 5 to 35 dB. Three main curves are shown for G\_n = infinity, 35 dB, and 25 dB. Data points are plotted for G\_n = infinity (x), G\_n = 35 dB (square), and G\_n = 25 dB (circle). Some points have vertical error bars. A dashed line indicates the 95% confidence limits. The legend specifies symbols for ascending and descending parts of the curves and adapted curves from ITU-T recommendations [10] and [23]. + +FIGURE 3 + +TOME V — Question 18/XII, Annexe 6 + +Figure 6 – Document No. 6 – French chart + +##### CCITTの概要 + +##### 沿革 + +CCITTは、国際電気通信連合（ITU）の四つの常設機関（事務総局、国際周波数登録委員会、CCIR、CCITT）の一つとして、ITUの中でも、世界の国際通信上の諸問題を真先に取上げ、その解決方法を見出して行く重要な機関である。日本名は、国際電信電話諮問委員会と称する。 + +CCITTの前身は、CCIF（国際電話諮問委員会）とCCIT（国際電信諮問委員会）である。CCIFは、1924年にヨーロッパに「国際長距離電話通信諮問委員会」が設置され、これが1925年のパリ電信電話会議のとき、正式に、「国際電話諮問委員会」として万国電信連合の公式機関となったものである。CCITは、同じく1925年の会議のとき、CCIFと併立するものとして設置された。 + +そして、CCIFは、1956年の12月に第18回総会が開催されたのち、CCITは、同年同月に第8回総会が開催されたのち、併合されて現在のCCITTとなった。このCCITTは、CCIFとCCITが解散した直後、第1回総会を開催し、第2回総会は、1960年にニューデリーで、第3回総会は、1964年、ジュネーブで、第4回総会は、1968年、アルゼンチンで開催された。 + +CCIFとCCITが合併したのは、有線電気通信の分野、とくに伝送路について電信回線と電話回線とを技術的に分ける意味がなくなってきたこと、各国とも大體において、電信部門と電話部門は同一組織内にあること、CCIFの事務局とCCITの事務局の合併による効率増進等がおもな理由であった。 + +CCITTは、上述のように、ヨーロッパ内の国々によって、ヨーロッパ内の電信・電話の技術・運用・料金の基準を定め、あるいは統一をはかってきたので、現在でも、その影響を受け、会合参加国は、ヨーロッパの国が多く、ヨーロッパで生起する問題の研究が多い。たとえば、1960年のCCITT勧告の中で、技術上配慮する距離は約2,500 kmであったが、これはヨーロッパ内領域を想定したものである。 + +しかしながら、1956年9月に敷設された大西洋横断電話ケーブルは、大陸間電話通信の自動化および半自動化への技術的可能性を与え、CCITTがこの問題を取り上げるに及び、CCITTの性格は漸次、汎世界的色彩を実質的に帯びるに至った。この汎世界的性格は第2次世界大戦後目ざましくなったアジア・アフリカ植民地の独立に伴ってITUの構成員の中にこれらの国が加わり、ITUの中に新しい意見が導入されたことにも起因して、技術面、政治面の双方から導入されてき + +た。CCITTの汎世界化は、1960年の第2回総会がニューデリーで開催されたことにもあらわれている。この総会までは、CCIT、CCIFのいずれにしろ、アメリカやアジアで総会が開催されたことがなく、CCITT委員長も、ニューデリー総会の準備文書で、この点には注目すべきであるとのべている。 + +##### 任務 + +ITUは、全権委員会、主管庁会議を始めとして、七つの機関をもち、それぞれの機関の権限と任務は国際電気通信条約に明記されている。そこで条約を参照してみるならば、CCITTの任務は、つぎのとおりとなっている。 + +「国際電信電話諮問委員会（CCITT）は、電信および電話に関する技術、運用および料金の問題について研究し、および意見を表明することを任務とする。」（1965年モントルー条約第187号） + +「各国諮問委員会は、その任務の遂行に当たって、新しい国または発展の途上にある国における地域および国際的分野にわたる電気通信の創設、発達および改善に直接関連のある問題について研究し、および意見を作成するように妥当な注意を払わなければならない。」（同第188号） + +「各国諮問委員会は、また、関係国の要請に基づき、その国内電気通信の問題について研究し、かつ、勧告を行なうことができる。」（同第189号） + +上記第187号と第188号にいわゆる「意見」とは、フランス語の *Avis* から訳したもので、英語では、「勧告（Recommendation）」となっている。CCITTの表明する意見は、国際法には強制力をもたないものであつて、この点が、条約、電信規則、電話規則等各国を拘束する力をもっているものと異なる。もっとも意見とは称しても、技術的分野では、電信規則のごとき、各国政府が承認してその内容を実施する強制規則をもたないので、実際にある機器の仕様を定める場合には、多くの国の意見が統一されたこの「意見」に従わなければ、円滑な国際通信を行なうことができない場合が多い。この意見（または勧告）は、国際通信を行なう場合各国が直面する問題について、具体的意見を表明するもので、たとえば、大陸間ケーブルで大陸間通話を半自動化しようとする場合、その信号方式や取り扱う通話の種類および料金は、どのようにするかを研究して意見を表明する。したがって、CCITTの活動は、つねに時代の最先端を行くもので、CCITTの活動方向は、そのまま世界の国際通信の活動方向であるともいえる。 + +この意見は、また、電信規則以下のその他の規則のごとく、数年以上の間隔をもつて開催される主管庁会議というような大会議の決定をまたなくとも表明することができ、また、その改正も容易であるので、現在のように進歩の早い国際通信界では、関係国の意見を統一した国際的見解としては非常に便利である。 + +Figure 7 – Document No. 7 – Kanji + +##### memorandum + +| | | +|-----------------------------------|---------------------------------------| +| FROM:
A.P. Spriggs
Research | TO:
G.V. Smith
Project Planning | +| TEL: | DATE: 1-9-71 | +| EXTN: 2041 | | + +We know that, where possible, data is reduced to alphanumeric form for transmission by communication systems. However, this can be expensive, and also some data must remain in graphic form. For example, we cannot key-punch an engineering drawing or weather map. + +I think we should realise that high speed facsimile transmissions are needed to overcome our problems in efficient graphic data communication. We need research into graphics data compression. + +Any comments? + +Albert. + +# WELL, WE ASKED FOR IT! + +Figure 8 – Document No. 8 – Handwritten memorandum + +### 6.2 ITU-T T.22 test chart No. 4 – Black-white facsimile test chart BW01 + +This bi-level image is the digitization (at 400 pels per inch) of the high-contrast black/white chart that is one of two charts that make up [ITU-T T.22] (see Figure 9 and Table 2). Figure 9 contains text in a variety of languages, fonts and pitches and various test patterns. + +**Table 2 – High-contrast test chart image** + +| Figure number | Image | Description | Dimensions | | | | Resolution (pixels/inch)
(1 bit/pixel) | Size (MBytes) | | | +|---------------|-----------------------------|----------------------|------------|--------|--------|--------|-------------------------------------------|---------------|--|--| +| | | | Pixels | | Inches | | | | | | +| | | | Width | Height | Width | Height | | | | | +| Figure 9 | ITU-T T.22 test chart No. 4 | Facsimile test chart | 3504 | 4750 | 8.76 | 11.88 | 400 | 2.09 | | | + +![Figure 9 – Test pattern facsimile test chart BW01. This is a complex technical chart used for testing facsimile transmission. It includes a top ruler with markings from 4 to 0 and 0 to 4. The chart features various geometric patterns: a large circular fan pattern in the upper center, several sets of parallel lines (horizontal, vertical, and diagonal) in different orientations and densities, and a series of small squares and rectangles. Text is arranged in multiple columns and rows, including uppercase and lowercase alphabets, numbers, and specific font names like 'Courier 12 pt.', 'Prestige Elite Bold', 'Italia Book', and 'Helvetica Medium'. There are also sections with Arabic, Cyrillic, and Chinese characters. A diagonal line runs from the top left towards the bottom right. At the bottom, there are more text blocks in Russian, Chinese, and English, along with a ruler and a small table of values.](b2d16e07bfa79d67a8adabf7e26c7764_img.jpg) + +ABCDEFGHIJKLM NOPQRSTUVWXYZ +abcdefghijklmnopqrstuvwxyz +1234567890 Courier 12 pt. + +ABCDEFGHIJKLM NOPQRSTUVWXYZ +abcdefghijklmnopqrstuvwxyz +1234567890 Prestige Elite Bold + +ABCDEFGHIJKLM NOPQRSTUVWXYZ +abcdefghijklmnopqrstuvwxyz +1234567890 Italia Book + +ABCDEFGHIJKLM NOPQRSTUVWXYZ +abcdefghijklmnopqrstuvwxyz +1234567890 Helvetica Medium 4 pt. + +ABCDEFGHIJKLM NOPQRSTUVWXYZ +abcdefghijklmnopqrstuvwxyz +1234567890 Helvetica Medium 6 pt. + +ABCDEFGHIJKLM NOPQRSTUVWXYZ +abcdefghijklmnopqrstuvwxyz +1234567890 Helvetica Medium 8 pt. + +ABCDEFGHIJKLM NOPQRSTUVWXYZ +abcdefghijklmnopqrstuvwxyz +1234567890 Helvetica Medium 10 pt. + +المجموعة الثانية +أ ، أ ، إ ، ب ، ة ، ت ، ث ، ج ، ح +خ ، د ، ذ ، ر ، ز ، س ، ش ، ص +ض ، ط ، ظ ، ع ، غ ، ف ، ق ، ك +ل ، م ، ن ، هـ ، و ، ي ، لا ، لأ ، لإ +2 1 0 9 8 7 6 5 4 3 2 1 0 +× % [ ] ( ) « » + / ± = < > : ; ، . + +13.75P +男女体操 +家庭用品 +新春景色 +普通教育 + +傳輸試驗用 +万有引力 +文化交流 +共同研究 +主要内容 + +7.875P +男女体操 +家庭用品 +新春景色 +普通教育 + +ГРУППА № 1-ДЛЯ ИСПЫТАНИЯ ПЕРЕДАЧИ +БУКВА КЕГЛЬ 8 +АБВГДЕЖЗИЙКЛМНОПРСТУФХЦЧШЩЪЫЬЭЮЯ +абвгдежзийклмнопрстуфхцчшщъыьэюя +1234567890 + +ГРУППА № 2-ДЛЯ ИСПЫТАНИЯ ПЕРЕДАЧИ +БУКВА КЕГЛЬ 10 + +Grupo n° I para prueba de transmisión de los caracteres +HELVETICA 8 PUNTOS +A B C D E F G H I J K L M N O P Q R S T U V W X Y Z +a b c d e f g h i j k l m n o p q r s t u v w x y z +1 2 3 4 5 6 7 8 9 0 +\$ 2 3 œ F [ ] ç N . £ - ± x : © • ß \_ é + = § / ( ) & % \* + +Groupe n° II pour test de transmission des caractères +HELVETICA 10 POINTS + +BLACK-WHITE FACSIMILE TEST CHART BW01 + +Figure 9 – Test pattern facsimile test chart BW01. This is a complex technical chart used for testing facsimile transmission. It includes a top ruler with markings from 4 to 0 and 0 to 4. The chart features various geometric patterns: a large circular fan pattern in the upper center, several sets of parallel lines (horizontal, vertical, and diagonal) in different orientations and densities, and a series of small squares and rectangles. Text is arranged in multiple columns and rows, including uppercase and lowercase alphabets, numbers, and specific font names like 'Courier 12 pt.', 'Prestige Elite Bold', 'Italia Book', and 'Helvetica Medium'. There are also sections with Arabic, Cyrillic, and Chinese characters. A diagonal line runs from the top left towards the bottom right. At the bottom, there are more text blocks in Russian, Chinese, and English, along with a ruler and a small table of values. + +Figure 9 – Test pattern facsimile test chart BW01 + +### 6.3 Legibility test chart + +This digitized image (see Figure 10 and Table 3) contains random text in four different fonts with six different point sizes. Plus, its lower half includes half-tone imagery that uses five different screen densities (65, 85, 120, 133 and 150 lines/inch). + +**Table 3 – Legibility test chart image** + +| Figure number | Image | Description | Dimensions | | | | Resolution
(pixels/inch)
(1 bit/pixel) | Size
(MBytes) | | | +|---------------|--------------------|--------------------------------------------------|------------|--------|--------|--------|----------------------------------------------|------------------|--|--| +| | | | Pixels | | Inches | | | | | | +| | | | Width | Height | Width | Height | | | | | +| Figure 10 | Half-tone
chart | Text for
legibility
testing,
half-tones | 1728 | 2336 | 8.64 | 11.68 | 200 | 0.51 | | | +| | | | 2048 | 2800 | 8.53 | 11.67 | 240 | 0.72 | | | +| | | | 2560 | 3500 | 8.53 | 11.68 | 300 | 1.13 | | | +| | | | 3456 | 4672 | 8.64 | 11.67 | 400 | 2.02 | | | +| | | | 4096 | 5600 | 8.53 | 11.67 | 480 | 2.87 | | | + + + +### 6.4 Bi-level half-tones + +Figure 11 through Figure 17 display bi-level half-tone images (see Table 4). Figures 11, 12, 13 and 14 show dithered sailboat images. The four sailboat images were made by processing a grayscale sailboat image with four different algorithms: The processing included $8 \times 8$ dithering for Figure 11, error diffusion for Figure 12, $4 \times 4$ dithering for Figure 13 and $3 \times 3$ dithering for Figure 14. + +Figure 15 is a composite of the house with sky image. Starting in clockwise order from the upper left, the dither patterns are ordered $4 \times 4$ , random dithering, ordered $8 \times 8$ and clump dithering. + +Figure 16 combines a screened half-tone image and an electronically scanned text that has been inverted. Both the text and the image portion of the document were extracted from a magazine. Figure 17 is a composite of electronically scanned segments of magazine pages. It includes a half-tone, text and inverted text. + +**Table 4 – Half-tone images** + +| Figure number | Image | Description | Dimensions | | | | Resolution (pixels/inch)
(1 bit/pixel) | Size (MBytes) | | | +|---------------|--------------------------|--------------------------------------------|------------|--------|--------|--------|-------------------------------------------|---------------|--|--| +| | | | Pixels | | Inches | | | | | | +| | | | Width | Height | Width | Height | | | | | +| Figure 11 | Sailboat No. 1 | $8 \times 8$ dithering | 3072 | 2048 | 7.68 | 5.12 | 400 | 0.79 | | | +| Figure 12 | Sailboat No. 2 | Error diffusion | 3072 | 2048 | 7.68 | 5.12 | 400 | 0.79 | | | +| Figure 13 | Sailboat No. 3 | $4 \times 4$ dithering | 3072 | 2048 | 7.68 | 5.12 | 400 | 0.79 | | | +| Figure 14 | Sailboat No. 4 | $3 \times 3$ dithering | 3072 | 2048 | 7.68 | 5.12 | 400 | 0.79 | | | +| Figure 15 | House with Trees | Dithered composite | 1904 | 1488 | 9.52 | 7.44 | 200 | 0.36 | | | +| Figure 16 | Magazine Text, Half-tone | Screened half-tone and inverted text | 3456 | 4416 | 4.32 | 5.52 | 800 | 1.91 | | | +| Figure 17 | Magazine Page, Composite | Contains half-tone, text and inverted text | 3072 | 4352 | 7.68 | 10.88 | 400 | 1.68 | | | + +![A black and white photograph of a sailboat's mast and sails. The sails feature a dark and light striped pattern. The number '690' is printed on the sails, and the call sign 'C6C' is visible on the mast. The image shows a low-angle view looking up at the mast against a light sky.](b91e305493a4852dca57a801f54085c8_img.jpg) + +A black and white photograph of a sailboat's mast and sails. The sails feature a dark and light striped pattern. The number '690' is printed on the sails, and the call sign 'C6C' is visible on the mast. The image shows a low-angle view looking up at the mast against a light sky. + +**Figure 11 – Sailboat No. 1 ( $8 \times 8$ Dither)** + +![A black and white photograph of a sailboat's mast and sails, similar to Figure 11. The sails have a striped pattern and the number '690' is visible. The call sign 'C6C' is on the mast. This image illustrates the effect of error diffusion, showing a slightly different texture or noise pattern compared to Figure 11.](0484c5fce6aa2558cf08aa4125ecc08d_img.jpg) + +A black and white photograph of a sailboat's mast and sails, similar to Figure 11. The sails have a striped pattern and the number '690' is visible. The call sign 'C6C' is on the mast. This image illustrates the effect of error diffusion, showing a slightly different texture or noise pattern compared to Figure 11. + +**Figure 12 – Sailboat No. 2 (Error diffusion)** + +![Black and white photograph of the sails of Sailboat No. 3, featuring a 4x4 dither pattern. The sails display the call sign '0ea 690' and the code 'C6C 25'.](e9a1dfde7b55d69a0a56f5bbe35328d4_img.jpg) + +A black and white photograph showing the sails of a sailboat. The sails are covered in a dither pattern of dark and light stripes. The call sign '0ea 690' is printed on the sails. The code 'C6C 25' is also visible on the sail. + +Black and white photograph of the sails of Sailboat No. 3, featuring a 4x4 dither pattern. The sails display the call sign '0ea 690' and the code 'C6C 25'. + +**Figure 13 – Sailboat No. 3 (4 × 4 Dither)** + +![Black and white photograph of the sails of Sailboat No. 4, featuring a 3x3 dither pattern. The sails display the call sign '0ea 690' and the code 'C6C 25'.](05c9994c1f5daf53d0d9b107657d7a17_img.jpg) + +A black and white photograph showing the sails of a sailboat. The sails are covered in a dither pattern of dark and light stripes. The call sign '0ea 690' is printed on the sails. The code 'C6C 25' is also visible on the sail. + +Black and white photograph of the sails of Sailboat No. 4, featuring a 3x3 dither pattern. The sails display the call sign '0ea 690' and the code 'C6C 25'. + +**Figure 14 – Sailboat No. 4 (3 × 3 Dither)** + +![Figure 15: A 2x2 grid of images showing a house with trees. The top-left image is a standard grayscale photograph. The top-right image is a dithered version of the same scene. The bottom-left image is a dithered version of the top-left image. The bottom-right image is a standard grayscale photograph, identical to the top-left one.](ae02603e9e4b46477222bf72c1c7c7f6_img.jpg) + +Figure 15: A 2x2 grid of images showing a house with trees. The top-left image is a standard grayscale photograph. The top-right image is a dithered version of the same scene. The bottom-left image is a dithered version of the top-left image. The bottom-right image is a standard grayscale photograph, identical to the top-left one. + +Figure 15 – House with trees (Dithered composite) + +![Figure 16: A magazine page layout. On the left is a black and white photograph of a harbor scene with buildings and boats. On the right is a column of text with varying line lengths, simulating magazine text.](56a7fc5964ed9463fa47ca8a60568dec_img.jpg) + +fun and sport. + +Famous for its International Film Festival, Cannes enjoys a dry, mild climate, not only for sunworshippers and sports enthusiasts but also for the vibrant nightlife of casinos, cafés, and galas that draws celebrities from around the world. + +The Promenade de la Croisette is the city's broad, tree-lined boulevard between the grand, elegant hotels and the Mediterranean seafront. The Palais des Festivals, the city's convention center, theater, boutiques, and museums make Cannes a city where you can provide more than just a vacation. An engaging variety of tourist activities include a visit to the Mucem, the Museum of Mediterranean Civilizations, a ride to the observation tower at Super M, or a boat trip to the island of Île de la Ste. Marguerite to explore the fortified fifth-century monastery, the chapel, or to view the cell where the "Mask" was kept in solitary confinement of Louis XIV in 1687. + +Shopping is a must on rue d'Antibes, the city's main shopping street, where you can find everything from curious flowers which grow along the coast to the superb cuisine for which France is well-represented in numerous restaurants. An exciting range of dining experiences, from the extreme pleasures of *haute cuisine* to the lights of local fish dishes prepared in the traditional way. + +Figure 16: A magazine page layout. On the left is a black and white photograph of a harbor scene with buildings and boats. On the right is a column of text with varying line lengths, simulating magazine text. + +Figure 16 – Magazine text (Half-tone) + +...er sucht ja in der Wäsche noch ein Tante", erwiderte Jossie ... ihn. Es konnte auch sein, d... + sanft und wandte sich um, denn die Tür zum Lokal wurde + geöffnet, und der erste Gast dieses Tages trat ein. Sie war + einen Augenblick so verblüfft, daß sie nicht einmal guten + Tag sagen konnte. Dafür sagte Taubert es, und sie erkannte + sofort die Stimme, die sie am Telefon gehört hatte. Eines + war allerdings komisch: Sie hatte ein gutes Gedächtnis für + Gesichter, aber seins war noch nie hier im Sonnebachhöf- + chen aufgetaucht. Aber anderswo, dachte sie — anderswo. + Doch es fiel ihr nicht so schnell ein, wo es gewesen sein + könnte. + „Sie kommen um Ihre Mappe?" sagte sie. + „Erraten! Und Sie sind Fräulein Jossie Sonnebach und waren + so liebenswürdig, mich anzurufen." + „Ja! — Ihr Niersteiner ist kalt gestellt, Herr Doktor!" + Er lachte hellauf und Mathilde Sonnebach, die sich in der + Zwischenzeit ebenfalls umgestellt hatte, weil nämlich die- + ser Doktor durchaus kein alter Herr war, glaubte bemerken + zu müssen, daß man im Sonnebachhöfchen sehr wohl wisse, + mit welcher Temperatur man den Weißwein zu kredenzen + habe. „Zu kalt ist nämlich auch bei Weißwein von Übel", + erklärte sie. + „Wie überhaupt bei allem", erwiderte er mit einem ver- + steckten Lächeln. „Am schlimmsten aber ist es, wenn man + übereilen würde schon stimmen. + sel überließ den Gast der Nichte + Vehm den bestellten Niersteiner + Sinn selber an den Fenstertisch + ein so erfrischendes Lüftchen + da dünnen Strohgläser daneben + Siegenheiten benutzt wurden. + „... anstoßen?" fragte Dr. Taubert + auch ihn schmeckt er mir nicht — + „Ist etwas gefährlich, wenn man + dann muß... + doch zu zieren, ein zweites Glas + Tee voll und stieß mit ihm an. + sieht, daß ich Ihren Namen in + der „Ich hätte sonst gar nicht + N... + ein immer praktisch", erwiderte + ten nicht meine Sache. Aber + man man leicht sein Eigentum ver- + „Wie. Sie konnte der Lust, ihn + „Eer noch nie hier gewesen + sagte ihn entrüstet an, als er + doch so!" sagte sie ärgerlich. + +Berlin feiert in beiden Jetzt wußte Jossie mit einemmal, woher sie ihn kannte. Er + dung. Im Schöneberger atte, als sie damals mit Geheimrat Hettmann in der Wein- + heitsglocke läuten, wen ube in München saß, an einem der Nebentische saure Leber + beth II. von Großbritan gegessen, nein, gebackene, korrigierte sie ihr Erinnern. Es gab + Reagan und der franzo einen Zweifel, daß er es gewesen war. Es gab auch keinen + nach Berlin kommen. B zweifel, daß er hier im Sonnebachhöfchen zum ersten Mal + scheidplatz an der Berli einkehrte. Wie das mit der Mappe zusammenhing, mußte + damm. sich erst herauskristallisieren. Auf jeden Fall stand sein + „Er geht ja in der Wäsche noch ein, Tante", erwiderte Jossie ... + sanft und wandte sich um, denn die Tür zum Lokal wurde + geöffnet, und der erste Gast dieses Tages trat ein. Sie war + einen Augenblick so verblüfft, daß sie nicht einmal guten + Tag sagen konnte. Dafür sagte Taubert es, und sie erkannte + sofort die Stimme, die sie am Telefon gehört hatte. Eines + war allerdings komisch: Sie hatte ein gutes Gedächtnis für + Gesichter, aber seins war noch nie hier im Sonnebachhöf- + dachte sie — anderswo. + wo es gewesen sein + Sonnebach und waren + Doktor!" + ach, die sich in der + weil nämlich die- + glaubte bemerken + an sehr wohl wisse, + wein zu kredenzen + eißwein von Übel", + er mit einem ver- + r ist es, wenn man + r sie ihn kannte. Er + mann in der Wein- + entische saure Leber + ihr Erinnern. Es gab + Es gab auch keinen + hen zum ersten Mal + ammenhing, mußte + sich erst herauskristallisieren. Auf jeden Fall stand sein + Name darin. Demnach gehörte sie ihm oder hatte ihm + gehört, war ihm entwendet oder von ihm selber verschenkt + 28 *Juni 1987* + +Ta Sie strafen sich selber Lügen + mi... + Ga sie. „Darauf trinke ich + Jel hnen an, wenn Sie gestehen + lie... + be te", sagte er, sein Weinglas + Flamlich wirklich nicht, wie + ... ich kann mir nur denken, + meiner Brüder einmal hier im Sonnebachhöfchen + über den Durst getrunken hat und dann in se- + seligkeit vergaß, die Mappe an sich zu nehmen. + Verdienst bin ich nun der Nutznieser dieser Ver- + Sie soll gesegnet sein! Prost, Fräulein Jossie!" + „Prost!" sagte sie belustigt, stieß mit ihm an, + dann die Mappe aus dem Einbauschrank herun + Sie, hier steht Ihr Name eingezeichnet - cand. med. + „Selige Zeiten!" lachte Taubert. „Das Leder ha + ausgehalten." + Jossie nickte, spielte mit dem Verschluß der M + das etwas verrostete Schloß auf- und zuspränge + dann von neuem an. + Taubert nahm sie ihr behutsam aus den Händen + sie neben sich auf das Fensterbrett. „Sie werden + denken können, wieso ich am Telefon gesagt ha + Niersteiner ohne Sprudel möchte. — Ich habe + einer Weinstube in München gesessen, als Sie m + ist eh... + mit' und Sie haben ihn deswegen getadelt und 'bra + „Ich erinnere mich", sagte Jossie. + „Erinnern Sie sich auch meiner?" + „Auch Ihrer, ja! — Sie saßen an einem der Nebe + aßen gebackene Leber." + „Und bis ich auf- und mich umsah, waren Sie + Taubert. „Aber der Himmel hat mir diesen reize + mit der Mappe geschickt, und auf den trinken wi + Gott, ob ich Sie sonst so schnell gefunden hätte." + Jossie wollte fragen: „Haben Sie mich denn gesu, + ließ es am besten sein. Er war nicht der erste + bestimmt auch nicht der letzte sein, bei dem + Flämmchen der Zuneigung aufglimmen sah. Es b + ebenso schnell wieder herunter und erlosch, ehe e + geben vermochte. Das war weder etwas Neues. + +![Black and white photograph of a street scene with buildings and a car.](e4f0e151fe7091d65ea97d178b1e424f_img.jpg) + +Figure 17 – Magazine composite page + +20 Rec. ITU-T T.24 (11/2015) + +### 6.5 ITU-T T.22 test chart No. 5 – Continuous tone test chart CT01 + +Figure 18 is a test chart designed specifically for facsimile. It consists of several strips and patches of various grayscale levels and two photographs, an architectural photograph and a portrait. This test chart is part of [ITU-T T.22]. + +![Continuous tone facsimile test chart CT01](39cfe42bf47ba1f871d52952bfbdfab1_img.jpg) + +The image displays the Continuous tone facsimile test chart CT01. It is composed of several horizontal sections. At the top is a long, thin grayscale gradient bar. Below this is a row of 16 numbered squares, labeled 1 through 16. Underneath the numbered squares are three rows of grayscale patches, labeled A, B, and C on the left. Row A contains 16 patches, while rows B and C contain 15 patches each. Below these rows is a large rectangular area filled with numerous thin, horizontal grayscale lines of varying shades. At the bottom of the chart are two square photographs: on the left, an architectural view of a building with multiple levels of arches and columns; on the right, a portrait of an older man with a mustache, wearing a dark cap and a light-colored jacket. + +Continuous tone facsimile test chart CT01 + +CONTINUOUS TONE FACSIMILE TEST CHART CT01 + +Figure 18 – Continuous tone test chart CT01 + +### 6.6 House with trees and house with sky + +This set of grayscale images includes a house with sky photograph and a house with trees photograph (see Figures 19 and 20). The images have been digitized as shown in Table 5. + +Table 5 – Grayscale images + +| Figure number | Image | Description | Dimensions | | | | Resolution (pixels/inch) (8 bit/pixel) | Size (MBytes) | | | +|---------------|------------------|---------------------------------------------|------------|--------|--------|--------|----------------------------------------|---------------|--|--| +| | | | Pixels | | Inches | | | | | | +| | | | Width | Height | Width | Height | | | | | +| Figure 19 | House with trees | Photo of a house surrounded by trees | 940 | 820 | 4.70 | 4.10 | 200 | 0.78 | | | +| | | | 1128 | 984 | 4.70 | 4.10 | 240 | 1.12 | | | +| | | | 1410 | 1230 | 4.70 | 4.10 | 300 | 1.74 | | | +| | | | 1880 | 1640 | 4.70 | 4.10 | 400 | 3.09 | | | +| Figure 20 | House with Sky | Photo of a house; decorative plantings only | 940 | 830 | 4.70 | 4.15 | 200 | 0.79 | | | +| | | | 1128 | 996 | 4.70 | 4.15 | 240 | 1.13 | | | +| | | | 1410 | 1245 | 4.70 | 4.15 | 300 | 1.76 | | | +| | | | 1880 | 1660 | 4.70 | 4.15 | 400 | 3.13 | | | + +![A grayscale photograph of a house with trees, labeled as Figure 19. The house is a single-story structure with a gabled roof and a chimney. It is surrounded by bare trees and shrubs. Below the photograph is a color calibration bar with 24 numbered color patches.](0eb742ed939b1846d05da644664fa9b7_img.jpg) + +A grayscale photograph of a house with trees, labeled as Figure 19. The house is a single-story structure with a gabled roof and a chimney. It is surrounded by bare trees and shrubs. Below the photograph is a color calibration bar with 24 numbered color patches. + +Figure 19 – House with trees + +![A black and white photograph of a two-story house with a gabled roof and a dormer window. The house has a mix of light and dark siding. A tall antenna is visible on the roof. The image is part of a test chart, with a vertical color bar on the left side showing 21 numbered color patches from 1 to 21.](6a73c2b5fcbc3ec5ab9cc694467a9da6_img.jpg) + +A black and white photograph of a two-story house with a gabled roof and a dormer window. The house has a mix of light and dark siding. A tall antenna is visible on the roof. The image is part of a test chart, with a vertical color bar on the left side showing 21 numbered color patches from 1 to 21. + +**Figure 20 – House with sky** + +### **6.7 ITU-T T.23 test chart No. 6 – 4-Colour printing facsimile test chart 4CP01** + +This set of images comes from the facsimile colour test chart (see Figure 21 and Table 6). + +The toys photo shows higher sharpness for fine detail in the stuffed animals and the faces, and provides a range of textures and patterns. The presence of both bright and pastel colours provides widespread variations in luminance, hue and saturation. In addition, the image is rich in slowly varying colour textures mixed with sharp colour boundaries. + +The computer-generated simulation of spheres image exhibits shadings for a 3-dimensional effect. It shows various-sized differently-coloured spheres on a black background. It provides a wide range of colour shadings with distinct edges. In general, each sphere is one colour, shaded to give a 3-dimensional appearance. The gradual transition in colour of each sphere's shading provides an excellent medium for discerning possible contouring effects. If contouring is present, it will usually manifest itself as a series of concentric circles with slightly different colours. The spheres' edges also provide sharp boundaries against both the background and other spheres. + +The graphics image is from a magazine cover and exhibits a 3-dimensional effect. It uses pastel colours to denote surfaces and fine black lines to enhance details. It contains a number of repetitive patterns coupled with sharp boundaries between various colours. + +**Table 6 – Colour images** + +| Figure number | Image | Colour space
(8 bits/comp.) | Dimensions | | | | Resolution
(pixels/inch)
(24 bits/pixel) | Size
(MBytes) | | | +|---------------|---------------------------------|--------------------------------|------------|--------|--------|--------|------------------------------------------------|------------------|--|--| +| | | | Pixels | | Inches | | | | | | +| | | | Width | Height | Width | Height | | | | | +| Figure 21 | Scanned colour chart | CIELAB | 1688 | 2347 | 8.44 | 11.74 | 200 | 11.89 | | | +| Figure 21 | Scanned colour chart | CIELAB | 3399 | 4752 | 8.50 | 11.88 | 400 | 48.46 | | | +| Figure 21 | Computer-generated colour chart | CIELAB | 1752 | 2375 | 8.76 | 11.88 | 200 | 12.49 | | | +| Figure 21 | Computer-generated colour chart | CIELAB | 3504 | 4750 | 8.76 | 11.88 | 400 | 49.94 | | | +| Figure 21 | Kids with toys | CIELAB | 3242 | 3656 | 8.11 | 9.14 | 400 | 35.56 | | | +| Figure 21 | Computer-generated spheres | CIELAB | 1024 | 512 | 2.56 | 1.28 | 400 | 1.58 | | | +| Figure 21 | Graphics art | CIELAB | 2644 | 3046 | 6.61 | 7.62 | 400 | 24.17 | | | + +![Figure 21: Colour test chart 4CP01. A complex calibration chart featuring a circular resolution target, a color grid labeled A-R and 1-8, color bars, grayscale steps, a text section titled 'ITU TIMES', a photograph of a man and children with toys, and a technical diagram of an optical system. The diagram shows light beams passing through layers labeled BEAM, DATA, CELL, VOLTAIC, PHOTO-, VIA, LASER, and DETECTOR. The chart is surrounded by measurement scales and resolution markers (3 6 9).](008b6e24fa6aef654a11223efed035dd_img.jpg) + +**ITU TIMES** + +**CCITT ROLE** The CCITT will promote the development of technical facilities and their most efficient operation with a view to improving the efficiency of telecommunication services, increasing their usefulness and making them as far as possible, generally available to the public. + +傳輸試驗用字第一組 10.5P +万有引力 科学方法 男女体操 傳輸試驗用字第一組 7.875P +文化交流 地理条件 家庭用品 万有引力 科学方法 男女体操 +共同研究 相互往来 新春景色 文化交流 地理条件 家庭用品 +主要内容 世界各国 普通教育 共同研究 相互往来 新春景色 +主要内容 世界各国 普通教育 + +NOTE: "Telematic Services" includes such services as Facsimile, Teletex, Videotex, etc. +NOTE: "Telematic Services" includes such services as Facsimile, Teletex, Videotex, etc. + +**4-COLOR PRINTING FACSIMILE TEST CHART 4CP01** + +Figure 21: Colour test chart 4CP01. A complex calibration chart featuring a circular resolution target, a color grid labeled A-R and 1-8, color bars, grayscale steps, a text section titled 'ITU TIMES', a photograph of a man and children with toys, and a technical diagram of an optical system. The diagram shows light beams passing through layers labeled BEAM, DATA, CELL, VOLTAIC, PHOTO-, VIA, LASER, and DETECTOR. The chart is surrounded by measurement scales and resolution markers (3 6 9). + +Figure 21 – Colour test chart 4CP01 + +### 6.8 CCIR images + +This set includes two images that were used in the original JPEG experiments prior to its adoption as an international standard (see Figures 22 and 23 and Table 7). They are in the YUV colour space. + +Table 7 – CCIR Images + +| Filename | Source | Image description | Colour space | Bits per component | Image dimensions
Pixels (W × H) | File size
(Bytes) | +|----------|----------|-------------------|--------------|--------------------|------------------------------------|----------------------| +| HOTEL | CCIR 601 | Hotel | YUV | 8 | 720 × 576 | 830 932 | +| GOLD | CCIR 601 | Gold | YUV | 8 | 720 × 576 | 830 932 | + +![A photograph of Hotel Lotus-Lila Plava Laguna Porec, showing a multi-story building with a stone wall and a person walking on a path.](2859466e7f590e4cce19e55ded6fd014_img.jpg) + +A photograph of Hotel Lotus-Lila Plava Laguna Porec. The image shows a multi-story building with a prominent stone wall in the foreground. A person is walking on a path that leads up to the building. The text "Hotel Lotus-Lila Plava Laguna Porec" is overlaid on the image in a stylized font. + +A photograph of Hotel Lotus-Lila Plava Laguna Porec, showing a multi-story building with a stone wall and a person walking on a path. + +Figure 22 – CCIR 601 YUV colour image: Hotel\* + +\* Due to technical reasons, Figures 22 and 23 could not be reproduced with their exact colours. + +![A color image of a village street scene, known as the 'Gold' image in the CCIR 601 YUV color space. It shows a row of traditional houses with tiled roofs and a person on a bicycle in the foreground. The image is characterized by a strong magenta/purple color cast across the entire scene.](84cebc242b1af66723a02cdf67fc98c9_img.jpg) + +A color image of a village street scene, known as the 'Gold' image in the CCIR 601 YUV color space. It shows a row of traditional houses with tiled roofs and a person on a bicycle in the foreground. The image is characterized by a strong magenta/purple color cast across the entire scene. + +**Figure 23 – CCIR 601 YUV colour image: Gold\*** + +### 6.9 Colour images (CMYK colour space) + +This set is made up of four colour images in the CMYK colour space, adapted from [b-ISO 12640-1] (see Figures 24, 25, 26 and 27 and Table 8). + +**Table 8 – CMYK images** + +| Filename | Source | Image description | Colour space | Bits per component | Image dimensions
Pixels (W × H) | File size
(Bytes) | +|----------|----------------------|-------------------|--------------|--------------------|------------------------------------|----------------------| +| BIKE | [b-ISO 12640-1] | N5 "Bike" | CMYK | 8 | 2048 × 2560 | 20 972 544 | +| WOMAN | [b-ISO 12640-1] | N1 "Portrait" | CMYK | 8 | 2048 × 2560 | 20 972 544 | +| CAFE | [b-ISO 12640-1] | N2 "Cafe" | CMYK | 8 | 2048 × 2560 | 20 972 544 | +| TOOLS | Crossfield drum scan | Tools | CMYK | 8 | 1524 × 1200 | 7 315 854 | + +![A still life photograph featuring a wireframe bicycle with a bird-like head, a color calibration chart, a clock, a still life arrangement of food and drink, and a resolution test chart.](7adda64806b35031fadb1fd5a227a9f8_img.jpg) + +A still life photograph used for color and resolution testing. In the background, a wireframe bicycle is mounted on a wall, with a stylized bird head (eye and beak) integrated into its frame. To the left of the bicycle is a color calibration chart with 30 color patches. Above the bicycle is a black square clock with white numbers and hands. To the right of the bicycle is a resolution test chart with various patterns of lines and dots. In the foreground, a still life arrangement includes a glass decanter with red liquid, a wine glass with red liquid, a plate of food (possibly lobster), a bowl of fruit (including grapes, apples, and oranges), and a small potted plant. The entire scene is set against a light-colored wall. + +A still life photograph featuring a wireframe bicycle with a bird-like head, a color calibration chart, a clock, a still life arrangement of food and drink, and a resolution test chart. + +Figure 24 – CMYK image: Bike + +![A portrait of a young woman with long, dark, curly hair, smiling and waving with both hands. She is wearing a white long-sleeved shirt under a dark-colored vest with a large, light-colored, textured patch on the front. She has a blue beaded headband and a blue beaded bracelet. The background is a plain, light blue-grey color. In the top right corner, the text 'ISO 400' is visible.](04b44fd5dd67a27f115d2ec8a328479e_img.jpg) + +A portrait of a young woman with long, dark, curly hair, smiling and waving with both hands. She is wearing a white long-sleeved shirt under a dark-colored vest with a large, light-colored, textured patch on the front. She has a blue beaded headband and a blue beaded bracelet. The background is a plain, light blue-grey color. In the top right corner, the text "ISO 400" is visible. + +A portrait of a young woman with long, dark, curly hair, smiling and waving with both hands. She is wearing a white long-sleeved shirt under a dark-colored vest with a large, light-colored, textured patch on the front. She has a blue beaded headband and a blue beaded bracelet. The background is a plain, light blue-grey color. In the top right corner, the text 'ISO 400' is visible. + +**Figure 25 – CMYK image: Portrait** + +![A vibrant street scene in a European city, likely Brussels, showing a long row of outdoor cafe seating with many people sitting at tables. The buildings are historic and feature signs like 'A L'OMBRE DE LA CATHEDRALE' and 'IN DE SCHADUW VAN DE KATHEDRAAL'.](120c189a42da51cf5266d4e50ca4d12a_img.jpg) + +ISO 400 + +A photograph of a busy outdoor cafe scene on a European street. The foreground and middle ground are filled with rows of small, round white tables and orange plastic chairs, many of which are occupied by people sitting and talking. The cafe is situated along a street lined with historic, multi-story brick buildings. A prominent yellow sign with blue text reads 'A L'OMBRE DE LA CATHEDRALE' and 'IN DE SCHADUW VAN DE KATHEDRAAL'. Other signs and awnings are visible on the buildings. The sky is clear and blue. In the top left corner, the text 'ISO 400' is printed. + +A vibrant street scene in a European city, likely Brussels, showing a long row of outdoor cafe seating with many people sitting at tables. The buildings are historic and feature signs like 'A L'OMBRE DE LA CATHEDRALE' and 'IN DE SCHADUW VAN DE KATHEDRAAL'. + +Figure 26 – CMYK image: Café + +![A collection of various tools and materials on a wooden workbench. In the background, a blue clock and three circular saw blades (one labeled BOSCH) are mounted on a blue brick wall. On the workbench, there is an open black toolbox containing various bits and drivers, a pair of green work gloves, a red-handled screwdriver, a blue-handled screwdriver, a metal file, a hammer, a brush, a can of Dulux paint, a power drill, a multi-meter, a color calibration chart, a ruler, a tape measure, a pair of pliers, and several other small tools and materials.](19fd552435a80d0ffda518b710d16908_img.jpg) + +A collection of various tools and materials on a wooden workbench. In the background, a blue clock and three circular saw blades (one labeled BOSCH) are mounted on a blue brick wall. On the workbench, there is an open black toolbox containing various bits and drivers, a pair of green work gloves, a red-handled screwdriver, a blue-handled screwdriver, a metal file, a hammer, a brush, a can of Dulux paint, a power drill, a multi-meter, a color calibration chart, a ruler, a tape measure, a pair of pliers, and several other small tools and materials. + +**Figure 27 – CMYK image: Tools** + +### 6.10 Colour images (RGB colour space) + +This set includes three images created with a digital camera and two compound images, all in the RGB colour space (see Figures 28, 29, 30, 31 and 32 and Table 9). The compound images consist of text with an embedded photograph. + +**Table 9 – RGB images** + +| Filename | Source | Image description | Colour space | Bits per component | Image dimensions pixels (W × H) | File size (Bytes) | +|----------|---------------------------|-------------------|--------------|--------------------|---------------------------------|-------------------| +| BIKE3 | Crossfield digital camera | Motorcycle | RGB | 8 | 781 × 919 | 2 153 821 | +| WATER | PhotoCD | Water | RGB | 8 | 2048 × 3072 | 18 899 574 | +| CATS | PhotoCD | Cats | RGB | 8 | 2048 × 3072 | 18 899 568 | +| CMPND1 | Computer generated | Text on photo | RGB | 8 | 512 × 768 | 1 179 892 | +| CMPND2 | Computer generated | Text and photo | RGB | 8 | 1024 × 1400 | 4 301 404 | + +![A close-up, front-three-quarter view of a purple and white Kawasaki Ninja 600 motorcycle. The bike features a prominent red stripe on the front fairing and a blue stripe on the side fairing. The 'Kawasaki' logo is visible on the fuel tank and front fairing. The front headlight is illuminated, and the front wheel has a red rim. The background is dark and out of focus.](50b476f2969d6978a83bf7832df632e1_img.jpg) + +A close-up, front-three-quarter view of a purple and white Kawasaki Ninja 600 motorcycle. The bike features a prominent red stripe on the front fairing and a blue stripe on the side fairing. The 'Kawasaki' logo is visible on the fuel tank and front fairing. The front headlight is illuminated, and the front wheel has a red rim. The background is dark and out of focus. + +A close-up, front-three-quarter view of a purple and white Kawasaki Ninja 600 motorcycle. The bike features a prominent red stripe on the front fairing and a blue stripe on the side fairing. The 'Kawasaki' logo is visible on the fuel tank and front fairing. The front headlight is illuminated, and the front wheel has a red rim. The background is dark and out of focus. + +**Figure 28 – RGB image: Motorcycle** + +![A landscape photograph showing a body of water in the foreground, distant mountains on the horizon, and a hazy sky.](3fec67008a13a4bccaf6914c862b2e42_img.jpg) + +A landscape photograph showing a body of water in the foreground, distant mountains on the horizon, and a hazy sky. The image is presented as a vertical strip within a black frame. + +A landscape photograph showing a body of water in the foreground, distant mountains on the horizon, and a hazy sky. + +**Figure 29 – RGB image: Water** + +![A photograph of two cats curled up together on a light-colored, textured surface, possibly a boat deck.](f3ce2d7158eb708e3487b8e35415db35_img.jpg) + +A photograph of two cats curled up together on a light-colored, textured surface, possibly a boat deck. The image is presented as a vertical strip within a black frame. + +A photograph of two cats curled up together on a light-colored, textured surface, possibly a boat deck. + +**Figure 30 – RGB image: Cats** + +Dear Paw, + +I was delighted to hear from you last week. Patti and I had a wonderful time during our week-long summer vacation. The weather was excellent, and the food was absolutely exquisite. I hope that we can repeat this next year and that you will join us too. + +We came back with a lot of fantastic memories, which we would like to share with you through some snapshots that we took. + +![A photograph of a man and a woman on a boat named 'TOP HAT' with 'I Love New York' text on the side.](c8f2f0357b99e801b1b0bb5faecf0787_img.jpg) + +A photograph of a man and a woman on a boat. The boat is white with blue accents and has "I Love New York" written on the side. The man is wearing a yellow jacket and the woman is wearing a white top. The boat is on a body of water with a city skyline in the background. The text "SUMMER OF 1994" is visible in the top left corner of the photo. + +A photograph of a man and a woman on a boat named 'TOP HAT' with 'I Love New York' text on the side. + +Our favorite is this picture of us aboard the "Top Hat", which I have pasted into this letter using some really neat advanced digital imaging technology on my home computer. We will ship the rest to you on a CD-ROM soon. Wishing you the best. + +Love, + +Susan + +Figure 31 – RGB image: Text on photo + +January 31, 2001 + +Dear Mom and Dad, + +How are both of you doing? I thought I would drop a line to say hi. Fanny, little Danny, and I are doing well. As you can see by the picture, little Danny isn't quite so little! Isn't this letter really great! I took a picture of Danny that was on a Kodak PhotoCD, and I merged it onto this letter using my computer. I then printed the letter using a color inkjet printer I just bought... + +![A close-up photograph of a young child (Danny) wearing a blue sweater.](0b2ff05a204b15e00ee9b3b8023d03d0_img.jpg) + +A close-up photograph of a young child with dark hair, smiling. The child is wearing a blue sweater. The background is slightly blurred, showing some yellow flowers. + +A close-up photograph of a young child (Danny) wearing a blue sweater. + +Danny's wearing the gorgeous BLUE sweater you gave him last time you were visiting. It just brings out the RED in his lips and cheeks. He definitely gets his good looks from his mother! + +Take care of yourselves and write soon. + +Love, + +Michael + +![Four stylized flower icons in green, blue, red, and yellow.](0067484c12a0dddcf91ca15b3ac375d4_img.jpg) + +Four stylized flower icons arranged in a row. From left to right, they are green, blue, red, and yellow. Each flower has a simple stem and leaves. + +Four stylized flower icons in green, blue, red, and yellow. + +Figure 32 – RGB image: Text and photo + +### **6.11 Fingerprint and medical images (Grayscale)** + +This set includes a scanned fingerprint at eight bits per component and five medical images at various pixel depths from eight to twelve bits per components (see Figures 33, 34, 35, 36, 37 and 38 and Table 10). + +**Table 10 – Grayscale medical images** + +| Filename | Source | Image description | Colour space | Bits per component | Image dimensions pixels (W × H) | File size (Bytes) | +|----------|---------------------|----------------------|--------------|--------------------|---------------------------------|-------------------| +| FINGER | Fingerprint | 11010092 | mono | 8 | 512 × 512 | 262 482 | +| X-Ray | Medical X-ray | X-ray – "XR1.1" | mono | 12 | 2048 × 1680 | 6 881 312 | +| CR | Computer radiology | CR "CR-ABDM" | mono | 10 | 1744 × 2048 | 4 465 286 | +| CT | Computer tomography | CT "CT.1" | mono | 12 | 512 × 512 | 524 320 | +| US | Ultrasound | Ultrasound "US1.DCM" | mono | 8 | 512 × 488 | 229 808 | +| MRI | Magnetic resonance | MRI "MRI.1" | mono | 11 | 256 × 256 | 92 160 | + +![A grayscale image of a fingerprint showing clear ridge patterns.](06c9dba199685f028e690b771f51841d_img.jpg) + +A grayscale image of a fingerprint. The image shows a clear pattern of ridges and valleys, typical of a fingerprint. The ridges are dark and the valleys are light, creating a high-contrast pattern. The overall shape is roughly oval, with the ridges curving around a central point. + +A grayscale image of a fingerprint showing clear ridge patterns. + +**Figure 33 – Fingerprint** + +![Anteroposterior (AP) X-ray of the human pelvis and upper femurs.](9527c318a7c3357ff7bdce06540aa3a3_img.jpg) + +An anteroposterior (AP) X-ray of the human pelvis and upper femurs. The image shows the bony structures of the pelvis, including the iliac crests, pubis, ischium, and the upper parts of the femurs. The sacrum and coccyx are visible in the center. A white letter 'R' is visible in the lower-left corner, indicating the right side of the patient. The image is in grayscale and has a slightly grainy texture. + +Anteroposterior (AP) X-ray of the human pelvis and upper femurs. + +**Figure 34 – Medical X-ray** + +[The printed representation of this image is not available.] + +**Figure 35 – Computer radiology** + +![Axial CT scan of the head at the level of the orbits.](cf504c5f59d17aff988b7c672a829d5c_img.jpg) + +An axial CT scan of the head at the level of the orbits. The image shows a cross-section of the skull, with the bony structures of the orbits, nasal cavity, and maxilla clearly visible. The brain tissue is shown in a darker shade of gray, while the bone is a lighter shade. The image is in grayscale and has a high level of contrast. + +Axial CT scan of the head at the level of the orbits. + +**Figure 36 – Computer tomography** + +![Figure 37: Ultrasound image of a kidney. The image shows a grayscale B-mode scan of a kidney in a longitudinal section. Text overlays include 'RIGHT KIDNEY' at the top, 'SD TIME 00:00:22' in the top right, and technical parameters like 'HD1 2008 CB E4 25190 11010 01-7 458 Y' and 'ID: b1:' in the bottom left. A scale bar on the right indicates depth in cm (1, 2, 3, 4, 5, 6, 7, 8, 9, 10).](0d21e56f563c92ea5d8ec3218a00c618_img.jpg) + +Figure 37: Ultrasound image of a kidney. The image shows a grayscale B-mode scan of a kidney in a longitudinal section. Text overlays include 'RIGHT KIDNEY' at the top, 'SD TIME 00:00:22' in the top right, and technical parameters like 'HD1 2008 CB E4 25190 11010 01-7 458 Y' and 'ID: b1:' in the bottom left. A scale bar on the right indicates depth in cm (1, 2, 3, 4, 5, 6, 7, 8, 9, 10). + +**Figure 37 – Ultrasound** + +![Figure 38: Magnetic resonance image (MRI) of a human head. The image is a grayscale axial slice showing the brain's internal structures, including the cerebral cortex, white matter, and ventricles. The image is somewhat noisy and has a high-contrast, grainy appearance typical of MRI scans.](db267ff9c1b97bbae0cb0856be1d8734_img.jpg) + +Figure 38: Magnetic resonance image (MRI) of a human head. The image is a grayscale axial slice showing the brain's internal structures, including the cerebral cortex, white matter, and ventricles. The image is somewhat noisy and has a high-contrast, grainy appearance typical of MRI scans. + +**Figure 38 – Magnetic resonance** + +### 6.12 Line drawing images + +This set includes a computer generated line drawing in colour (CIELAB colour space) and a scan of a fine arts engraving (grayscale). See Figures 39 and 40 and Table 11. + +**Table 11 – Line drawing images** + +| Filename | Source | Image description | Colour space | Bits per component | Image dimensions pixels (W × H) | File size (Bytes) | +|----------|--------------------|------------------------------|--------------|--------------------|---------------------------------|-------------------| +| PC | Computer generated | Printed circuit board layout | CIELAB | 8 | 1575 × 2185 | 10 324 620 | +| EDUC | Scan | Fine arts 1, engraving | mono | 8 | 2850 × 4096 | 11 676 100 | + +![A detailed printed circuit board (PCB) layout for a General Data Products device. The board is populated with numerous integrated circuits (ICs) labeled U1 through U40, various resistors (R1-R12), capacitors (C1-C4), and test points (TP1-TP3). It features multiple connectors along the left edge (J1-J7) and top edge (P1-P12). The layout is color-coded with green, purple, and red traces. At the bottom, text reads: 'TDP001 700-100138 Rev. 0 GENERAL DATA PRODUCTS Made In USA +0007'. Below the board image, the text 'SILKSCREEN (COMP SIDE)' is visible.](cbb2d311b20781a595488445ded48d0a_img.jpg) + +TDP001 700-100138 Rev. 0 GENERAL DATA PRODUCTS Made In USA +0007 + +SILKSCREEN (COMP SIDE) + +A detailed printed circuit board (PCB) layout for a General Data Products device. The board is populated with numerous integrated circuits (ICs) labeled U1 through U40, various resistors (R1-R12), capacitors (C1-C4), and test points (TP1-TP3). It features multiple connectors along the left edge (J1-J7) and top edge (P1-P12). The layout is color-coded with green, purple, and red traces. At the bottom, text reads: 'TDP001 700-100138 Rev. 0 GENERAL DATA PRODUCTS Made In USA +0007'. Below the board image, the text 'SILKSCREEN (COMP SIDE)' is visible. + +Figure 39 – Printed circuit board layout + +![Engraving titled 'La bonne Education' showing a woman reading to two children.](d9e17d9fe73ab1122fe304ff276008d4_img.jpg) + +An engraving titled "La bonne Education" (Good Education). The scene is set in a dimly lit room. On the left, a woman in 18th-century attire sits on a wooden stool, holding an open book and looking towards the right. In the center, a young girl sits at a small wooden table, leaning her head on her hand and looking at the book. To her right, a young boy sits on the floor, leaning against the table and looking at the book. A small dog is visible on the floor near the boy. In the background, a large circular mirror or painting is visible on the wall. The title "La bonne Education" is written in a large, elegant cursive script across the bottom of the image. Below the title, there is a line of smaller text: "A Paris, chez Wille, Graveur du Roi, Quay des Augustins." At the very bottom, there are two small inscriptions: "Dessiné par J. B. Greuze" on the left and "Gravé à Paris, d'après son dessin, et imprimé en Paris par P. J. Bachelier" on the right. + +Engraving titled 'La bonne Education' showing a woman reading to two children. + +Figure 40 – Engraving + +### 6.13 Fine arts images + +These images are two scans of the same fine arts painting at eight bits per component and twelve bits per component (see Figure 41 and Table 12). + +**Table 12 – Scanned fine arts images** + +| Filename | Source | Image description | Colour space | Bits per component | Image dimensions pixels (W × H) | File size (Bytes) | +|-----------------|---------------|--------------------------|---------------------|---------------------------|----------------------------------------|--------------------------| +| INGRES8 | Scan | Fine arts 2, painting | RGB | 8 | 4088 × 4608 | 56 512 700 | +| INGRES16 | Scan | Fine arts 3, painting | RGB | 12 | 4088 × 4608 | 113 025 212 | + +![A painting by Jean-Auguste-Dominique Ingres titled 'The Apotheosis of Victor Hugo' (1838). It depicts the elderly Victor Hugo seated in the foreground, wearing a dark academic robe, with his hand to his head in a pensive pose. Behind him stands a young woman in a white classical dress, pointing upwards with her right hand. To her right is a large, ornate lyre. The background features a dark interior with a red curtain on the left.](32e90b573aaa2cf95944dcd3eea79a0d_img.jpg) + +A painting by Jean-Auguste-Dominique Ingres titled "The Apotheosis of Victor Hugo" (1838). It depicts the elderly Victor Hugo seated in the foreground, wearing a dark academic robe, with his hand to his head in a pensive pose. Behind him stands a young woman in a white classical dress, pointing upwards with her right hand. To her right is a large, ornate lyre. The background features a dark interior with a red curtain on the left. + +A painting by Jean-Auguste-Dominique Ingres titled 'The Apotheosis of Victor Hugo' (1838). It depicts the elderly Victor Hugo seated in the foreground, wearing a dark academic robe, with his hand to his head in a pensive pose. Behind him stands a young woman in a white classical dress, pointing upwards with her right hand. To her right is a large, ornate lyre. The background features a dark interior with a red curtain on the left. + +**Figure 41 – Painting (Ingres 8 and Ingres 16)** + +### 6.14 Low-contrast grayscale images + +This set consists of generally low-contrast, eight bits per component grayscale images (see Figures 42, 43, 44, 45, 46, 47, 48 and 49 and Table 13). Included are four aerial photographs, a scenic view, and two low-contrast charts. + +**Table 13 – Low-contrast grayscale images** + +| Filename | Source | Image description | Colour space | Bits per component | Image dimensions pixels (W × H) | File size (Bytes) | +|----------|---------------------|-------------------|--------------|--------------------|---------------------------------|-------------------| +| AERIAL1 | Remote sensing | Aerial view 1 | Luminance | 8 | 14 565 × 14 680 | 213 843 694 | +| AERIAL2 | Remote sensing | Aerial view 2 | Luminance | 8 | 2 048 × 2 048 | 4 194 774 | +| CMPND3 | Compound | Graphics | Luminance | 8 | 5 120 × 6 624 | 33 915 328 | +| MAT | Digital camera | Mountains | Luminance | 8 | 1 528 × 1 146 | 175 153 | +| SEISMIC | Remote sensing | Texture | Luminance | 8 | 512 × 512 | 262 592 | +| TARGET | Graphics | Patterns | Luminance | 8 | 512 × 512 | 262 592 | +| TXTUR1 | MPEG-4 test image 1 | Aerial view | Luminance | 8 | 1 024 × 1 024 | 1 048 854 | +| TXTUR2 | MPEG-4 test image 2 | Aerial view | Luminance | 8 | 1 024 × 1 024 | 1 055 036 | + +![Aerial view 1 Remote sensing](37290987e9d8f148b8a59c405e9c60d7_img.jpg) + +This is a grayscale aerial photograph of a developed area, likely a resort or industrial park. The image shows a complex network of roads, numerous buildings of varying sizes, and several large, irregularly shaped ponds or reservoirs. The terrain appears to be a mix of cleared land and some forested areas, particularly towards the edges of the developed zone. The overall layout suggests a planned environment with integrated water features. + +Aerial view 1 Remote sensing + +**Figure 42 – Aerial view 1 Remote sensing** + +![Aerial view of a remote sensing facility with a large radar dome and several storage tanks.](ceb147a82430b08b7ffd0ea53313cc47_img.jpg) + +An aerial photograph of a remote sensing facility in a desert environment. The facility includes a large, white, hemispherical radar dome mounted on a tall, rectangular concrete structure. Several large, cylindrical storage tanks are visible, some with labels like 'WATER TANK' and 'FUEL TANK'. There are also several smaller buildings and a paved road winding through the site. The surrounding landscape is arid with sparse vegetation. + +Aerial view of a remote sensing facility with a large radar dome and several storage tanks. + +**Figure 43 – Aerial view 2 Remote sensing** + +![A collage of six grayscale images demonstrating compound graphics. Each image contains multiple overlapping text elements, icons, and background patterns. The text often repeats phrases like 'Quality Color Printing' and 'We are committed to the highest quality in the design, manufacture and service of all we sell.' The images include a windmill, a coffee cup, a butterfly, a magnifying glass, a paperclip, and a fish. A vertical color bar is visible on the right side of the collage.](8e1263a63a8c36c001a0c913d7e7fcce_img.jpg) + +The collage consists of six panels, each illustrating a different compound graphic design: + +- Top Left:** Features a windmill and a house. Text includes "We are committed to the highest quality in the design, manufacture and service of all we sell." and "Quality Color Printing". +- Top Right:** Features a coffee cup, a butterfly, and a large dollar sign. Text includes "MEMO MEMO MEMO" and "We are committed to the highest quality in the design, manufacture and service of all we sell." +- Middle Left:** Features a paperclip and a document. Text includes "Quality Color Printing" and "We are committed to the highest quality in the design, manufacture and service of all we sell." +- Middle Right:** Features a magnifying glass over a document. Text includes "Quality Color Printing" and "We are committed to the highest quality in the design, manufacture and service of all we sell." +- Bottom Left:** Features a paperclip and a document. Text includes "Quality Color Printing" and "We are committed to the highest quality in the design, manufacture and service of all we sell." +- Bottom Right:** Features a fish and the word "JPEG". Text includes "JjPpEeGg" and "JPEG". + +A vertical color bar is located on the right side of the collage, showing a gradient from light gray to dark gray. + +A collage of six grayscale images demonstrating compound graphics. Each image contains multiple overlapping text elements, icons, and background patterns. The text often repeats phrases like 'Quality Color Printing' and 'We are committed to the highest quality in the design, manufacture and service of all we sell.' The images include a windmill, a coffee cup, a butterfly, a magnifying glass, a paperclip, and a fish. A vertical color bar is visible on the right side of the collage. + +Figure 44 – Compound graphics + +![A black and white photograph of a snowy mountain range.](9a627a1ad2e909ac4af71874ed1b0502_img.jpg) + +A black and white photograph of a mountain range. The foreground shows a snow-covered slope with dark, rocky outcrops. In the middle ground, several jagged mountain peaks are visible, some covered in snow and others in shadow. The background shows more distant peaks under a clear sky. The overall scene is a high-altitude, alpine environment. + +A black and white photograph of a snowy mountain range. + +**Figure 45 – Digital camera** + +![A grayscale image showing a textured surface, likely water, with numerous small, irregular ripples and waves across the entire frame.](458fa1d6289ca26e7ebf990b7bb4508d_img.jpg) + +A grayscale image showing a textured surface, likely water, with numerous small, irregular ripples and waves across the entire frame. The texture is dense and uniform, with varying shades of gray representing the crests and troughs of the water surface. + +A grayscale image showing a textured surface, likely water, with numerous small, irregular ripples and waves across the entire frame. + +**Figure 46 – Texture remote sensing** + +![A collection of pattern graphics including grayscale ramps, line patterns, and geometric shapes.](69f318d79aa1cb9eb5972284b5f96f8b_img.jpg) + +This image is a composite of various pattern graphics used for testing. At the top is a horizontal grayscale ramp with 11 steps from black to white. Below this, on the left, is a 4x4 grid of squares, each containing a different line pattern (horizontal, vertical, or diagonal) with varying frequencies. To the right of this grid are two large, blurred circular spots, one light and one dark. Below the grid and spots are two smaller circles, one white and one black. Further down is a 2x2 grid of squares: the top-left is white with a thin black crosshair, the top-right is black with a thin white crosshair, and the bottom two are textured gray. At the bottom of the image is another horizontal grayscale ramp, this one with 10 steps from white to black. + +A collection of pattern graphics including grayscale ramps, line patterns, and geometric shapes. + +**Figure 47 – Pattern graphics** + +![Aerial grayscale image of a mountainous region with a river, a town, and an airport.](42a43cc7519e21ef6cb91774267a6519_img.jpg) + +This is a high-resolution grayscale aerial photograph used as a test image. It depicts a complex landscape featuring rugged, mountainous terrain on the left and right sides. A prominent river or waterway flows vertically through the center of the image. In the lower right quadrant, there is a developed area that includes a town with a grid-like street pattern and a large, rectangular airport runway. The image contains various textures and features, such as fields, forests, and built-up areas, which are typical for video compression testing. + +Aerial grayscale image of a mountainous region with a river, a town, and an airport. + +**Figure 48 – MPEG-4 test image 1** + +![A grayscale aerial photograph of a mountainous landscape, showing a winding road and a small settlement in the lower left.](879b09e03bd9b8c1ae22f8f38e86727f_img.jpg) + +This is a grayscale aerial photograph of a mountainous landscape. The terrain is rugged with numerous ridges and valleys. A winding road is visible in the lower left quadrant, leading towards a small settlement or village. The image is characterized by high contrast and some visible artifacts, typical of a test image for video compression standards like MPEG-4. + +A grayscale aerial photograph of a mountainous landscape, showing a winding road and a small settlement in the lower left. + +**Figure 49 – MPEG-4 test image 2** + +## Appendix I + +### Black/white pixel counts + +(This appendix does not form an integral part of this Recommendation.) + +The black/white pixel counts for all of the bi-level images in this Recommendation are summarized in Table I.1. For each bi-level image and its corresponding resolution(s), information is included on the image dimensions (in pixel units), the size of the raw image data (in bytes), the black and white pixel counts and the percentage of the image which is coloured black and white + +**Table I.1 – Black/white pixel counts** + +| File name | Image name | Res. | Size | | | Pixel counts | | Percent | | +|-----------|-----------------------|-----------|-------|--------|---------|--------------|----------|---------|--------| +| | | (pix./in) | Width | Height | (bytes) | Black | White | Black | White | +| F01_200 | Document No. 1 | 200 | 1728 | 2339 | 505224 | 104990 | 3936802 | 2.60% | 97.40% | +| F01_300 | (English letter) | 300 | 2592 | 3508 | 1136592 | 236943 | 8855793 | 2.61% | 97.39% | +| F01_400 | | 400 | 3456 | 4677 | 2020464 | 426637 | 15737075 | 2.64% | 97.36% | +| F01_600 | | 600 | 5184 | 7016 | 4546368 | 980552 | 35390392 | 2.70% | 97.30% | +| F02_200 | Document No. 2 | 200 | 1728 | 2339 | 505224 | 158713 | 3883079 | 3.93% | 96.07% | +| F02_300 | (Circuit drawing) | 300 | 2592 | 3508 | 1136592 | 350335 | 8742401 | 3.85% | 96.15% | +| F02_400 | | 400 | 3456 | 4677 | 2020464 | 643328 | 15520384 | 3.98% | 96.02% | +| F02_600 | | 600 | 5184 | 7016 | 4546368 | 1446165 | 34924779 | 3.98% | 96.02% | +| F03_200 | Document No. 3 | 200 | 1728 | 2339 | 505224 | 222697 | 3819095 | 5.51% | 94.49% | +| F03_300 | (French invoice) | 300 | 2592 | 3508 | 1136592 | 498319 | 8594417 | 5.48% | 94.52% | +| F03_400 | | 400 | 3456 | 4677 | 2020464 | 905106 | 15258606 | 5.60% | 94.40% | +| F03_600 | | 600 | 5184 | 7016 | 4546368 | 2004822 | 34366122 | 5.51% | 94.49% | +| F04_200 | Document No. 4 | 200 | 1728 | 2339 | 505224 | 371671 | 3670121 | 9.20% | 90.80% | +| F04_300 | (French text) | 300 | 2592 | 3508 | 1136592 | 837842 | 8254894 | 9.21% | 90.79% | +| F04_400 | | 400 | 3456 | 4677 | 2020464 | 1539573 | 14624139 | 9.52% | 90.48% | +| F04_600 | | 600 | 5184 | 7016 | 4546368 | 3587602 | 32783342 | 9.86% | 90.14% | +| F05_200 | Document No. 5 | 200 | 1728 | 2339 | 505224 | 222306 | 3819486 | 5.50% | 94.50% | +| F05_300 | (French text figures) | 300 | 2592 | 3508 | 1136592 | 490419 | 8602317 | 5.39% | 94.61% | +| F05_400 | | 400 | 3456 | 4677 | 2020464 | 892675 | 15271037 | 5.52% | 94.48% | +| F05_600 | | 600 | 5184 | 7016 | 4546368 | 1987057 | 34383887 | 5.46% | 94.54% | +| F06_200 | Document No. 6 | 200 | 1728 | 2339 | 505224 | 154711 | 3887081 | 3.83% | 96.17% | +| F06_300 | (French chart) | 300 | 2592 | 3508 | 1136592 | 341837 | 8750899 | 3.76% | 96.24% | +| F06_400 | | 400 | 3456 | 4677 | 2020464 | 622225 | 15541487 | 3.85% | 96.15% | +| F06_600 | | 600 | 5184 | 7016 | 4546368 | 1387214 | 34983730 | 3.81% | 96.19% | +| F07_200 | Document No. 7 | 200 | 1728 | 2339 | 505224 | 310743 | 3731049 | 7.69% | 92.31% | +| F07_300 | (Kanji) | 300 | 2592 | 3508 | 1136592 | 690828 | 8401908 | 7.60% | 92.40% | +| F07_400 | | 400 | 3456 | 4677 | 2020464 | 1239891 | 14923821 | 7.67% | 92.33% | +| F07_600 | | 600 | 5184 | 3035 | 1966680 | 1184951 | 14548489 | 7.53% | 92.47% | +| F08_200 | Document No. 8 | 200 | 1728 | 2339 | 505224 | 1603283 | 2438509 | 39.67% | 60.33% | + +**Table I.1 – Black/white pixel counts** + +| File name | Image name | Res. | Size | | | Pixel counts | | Percent | | +|-----------|-------------------|-----------|-------|--------|---------|--------------|----------|---------|--------| +| | | (pix./in) | Width | Height | (bytes) | Black | White | Black | White | +| F08_300 | (Memorandum) | 300 | 2592 | 3508 | 1136592 | 3613143 | 5479593 | 39.74% | 60.26% | +| F08_400 | | 400 | 3456 | 4677 | 2020464 | 6337111 | 9826601 | 39.21% | 60.79% | +| F08_600 | | 600 | 5184 | 7016 | 4546368 | 14259312 | 22111632 | 39.21% | 60.79% | +| F09_400 | T.22 test chart 4 | 400 | 3504 | 4750 | 2080500 | 2852132 | 13791868 | 17.14% | 82.86% | +| F10_200 | Half-tone chart | 200 | 1728 | 2336 | 504576 | 997022 | 3039586 | 24.70% | 75.30% | +| F10_240 | | 240 | 2048 | 2800 | 716800 | 1292813 | 4441587 | 22.54% | 77.46% | +| F10_300 | | 300 | 2560 | 3500 | 1120000 | 2052939 | 6907061 | 22.91% | 77.09% | +| F11_400 | Sailboat No. 1 | 400 | 3072 | 2048 | 786432 | 2500099 | 3791357 | 39.74% | 60.26% | +| F12_400 | Sailboat No. 2 | 400 | 3072 | 2048 | 786432 | 2551623 | 3739833 | 40.56% | 59.44% | +| F13_400 | Sailboat No. 3 | 400 | 3072 | 2048 | 786432 | 2558326 | 3733130 | 40.66% | 59.34% | +| F14_400 | Sailboat No. 4 | 400 | 3072 | 2048 | 786432 | 2515962 | 3775494 | 39.99% | 60.01% | +| F15_200 | House with trees | 200 | 1904 | 1488 | 354144 | 1672859 | 1160293 | 59.05% | 40.95% | +| F16_800 | Magazine text | 800 | 3456 | 4416 | 1907712 | 12337334 | 2924362 | 80.84% | 19.16% | +| F17_400 | Magazine page | 400 | 3072 | 4352 | 1671168 | 8617274 | 4752070 | 64.46% | 35.54% | + +## Appendix II + +### Sun Raster image format + +(This appendix does not form an integral part of this Recommendation.) + +The Sun Raster image file format is the native bitmap format of the Sun Microsystems UNIX platforms that use the SunOs operation system. This format can store black/white, grayscale and colour bitmapped images of any pixel depth. Optionally the use of colour maps and simple run-length compression are also supported. Most UNIX imaging applications support this format. + +The Sun Raster file is organized as a header, followed by an optional colour map and then by the bitmapped image data. The header is 32 bytes long and has the following format: + +``` +typedef struct SunRaster +{ + DWORD MagicNumber /*Magic number */ + DWORD Width; /*Width of the image in pixels*/ + DWORD Height; /*Height of the image in pixels*/ + DWORD Depth; /*Number of bits per pixel*/ + DWORD Length; /* Size of image in bytes */ + DWORD Type /* Type of raster file */ + DWORD ColorMapType; /*Type of color map*/ + DWORD ColorMapLength /*Size of the color map in bytes*/ +}; +``` + +Magic number identifies the file as a Sun Raster image and always contains the value 59A66A95h (hexadecimal). Besides identifying the format, the magic number provides a check that the bytes in the file are being read in the proper order. + +Width and height specify the size of the image in pixels. The width of a scan line is always a multiple of 16 bits, padded when necessary. + +Depth is the number of bits per pixel of the image data. + +Length is the size of the bitmapped image data in the bitmap file in bytes, (not including the colour map and header). + +Type is the version of the bitmapped file. + +ColorMapType indicates the type of colour map included in the file if any and ColorMapLength contains the number of bytes stored in the colour map + +For further information contact: + +Sun Microsystems Inc. +2550 Garcia Avenue +Mountain View, CA 94043 + +There are also a number of publicly available UNIX-based image file viewers that support the Sun Raster format. + +## Bibliography + +- [b-ITU-R BT.601] ITU-R BT.601 (2011), *Studio encoding parameters of digital television for standard 4:3 and wide screen 19:9 aspect ratios*. +- [b-ISO 12640-1] ISO 12640-1 (1997), *Graphic technology – Prepress digital data exchange – Part 1: CMYK standard colour image data (CMYK/SCID)*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.38-201511-I_PDF-E/raw.md b/marked/T/T-REC-T.38-201511-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..b9b236b84d330fe720d1a4f415f71fdd90897d16 --- /dev/null +++ b/marked/T/T-REC-T.38-201511-I_PDF-E/raw.md @@ -0,0 +1,6145 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**T.38** + +(11/2015) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES +Facsimile – Group 3 protocols + +# --- **Procedures for real-time Group 3 facsimile communication over IP networks** + +Recommendation ITU-T T.38 + +## ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES** + +| | | +|-----------------------------------------------------|------------------| +| Facsimile – Framework | T.0–T.19 | +| Still-image compression – Test charts | T.20–T.29 | +| Facsimile – Group 3 protocols | T.30–T.39 | +| Colour representation | T.40–T.49 | +| Character coding | T.50–T.59 | +| Facsimile – Group 4 protocols | T.60–T.69 | +| Telematic services – Framework | T.70–T.79 | +| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89 | +| Telematic services – ISDN Terminals and protocols | T.90–T.99 | +| Videotext – Framework | T.100–T.109 | +| Data protocols for multimedia conferencing | T.120–T.149 | +| Telewriting | T.150–T.159 | +| Multimedia and hypermedia framework | T.170–T.189 | +| Cooperative document handling | T.190–T.199 | +| Telematic services – Interworking | T.300–T.399 | +| Open document architecture | T.400–T.429 | +| Document transfer and manipulation | T.430–T.449 | +| Document application profile | T.500–T.509 | +| Communication application profile | T.510–T.559 | +| Telematic services – Equipment characteristics | T.560–T.649 | +| Still-image compression – JPEG 2000 | T.800–T.829 | +| Still-image compression JPEG XR | T.830–T.849 | +| Still-image compression – JPEG-1 extensions | T.850–T.899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T T.38 + +# Procedures for real-time Group 3 facsimile communication over IP networks + +## Summary + +Recommendation ITU-T T.38 defines the procedures to be applied to allow Group 3 facsimile transmission between terminals where, in addition to the public switched telephone network (PSTN) or integrated services digital network (ISDN), a portion of the transmission path used between terminals includes an IP network, e.g., the Internet. + +This revision of this Recommendation consolidates material from ITU-T T.38 (09/2010) with ITU-T T.38 (2010) Erratum 1 (04/13), ITU-T T.38 (2010) Amd. 1 (10/2014), T.Imp38 (02/2015), and adds new material to Appendix V related to multiple ITU-T T.38 domains connected in series. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|--------------------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T T.38 | 1998-06-18 | 8 | 11.1002/1000/4393 | +| 1.1 | ITU-T T.38 (1998) Amd. 1 | 1999-04-01 | 8 | 11.1002/1000/4601 | +| 1.2 | ITU-T T.38 (1998) Amd. 2 | 2000-02-10 | 8 | 11.1002/1000/4841 | +| 1.3 | ITU-T T.38 (1998) Cor. 1 | 2000-03-30 | 8 | 11.1002/1000/5144 | +| 1.4 | ITU-T T.38 (1998) Amd. 3 | 2000-11-17 | 16 | 11.1002/1000/5166 | +| 1.5 | ITU-T T.38 (1998) Amd. 4 | 2001-07-29 | 16 | 11.1002/1000/5527 | +| 2.0 | ITU-T T.38 | 2002-03-29 | 16 | 11.1002/1000/5689 | +| 2.1 | ITU-T T.38 (2002) Cor. 1 | 2003-07-14 | 16 | 11.1002/1000/6479 | +| 2.2 | ITU-T T.38 (2002) Amd. 1 | 2003-07-29 | 16 | 11.1002/1000/6507 | +| 2.3 | ITU-T T.38 (2002) Amd. 3 | 2004-01-30 | 16 | 11.1002/1000/7244 | +| 2.4 | ITU-T T.38 (2002) Amd. 2 | 2004-04-22 | 16 | 11.1002/1000/7239 | +| 3.0 | ITU-T T.38 | 2004-04-22 | 16 | 11.1002/1000/7313 | +| 3.1 | ITU-T T.38 (2004) Amd. 1 | 2005-01-08 | 16 | 11.1002/1000/7456 | +| 4.0 | ITU-T T.38 | 2005-09-13 | 16 | 11.1002/1000/8559 | +| 5.0 | ITU-T T.38 | 2007-04-06 | 16 | 11.1002/1000/9044 | +| 6.0 | ITU-T T.38 | 2010-09-13 | 16 | 11.1002/1000/10995 | +| 6.1 | ITU-T T.38 (2010) Amd. 1 | 2014-10-14 | 16 | 11.1002/1000/12293 | +| 7.0 | ITU-T T.38 | 2015-11-29 | 16 | 11.1002/1000/12681 | + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2016 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|------------------------------------------------------------------------------------------------|-------------| +| 1 Scope..... | 1 | +| 2 Normative references..... | 1 | +| 3 Definitions ..... | 3 | +| 4 Abbreviations and acronyms ..... | 3 | +| 5 Introduction..... | 5 | +| 5.1 Conventions..... | 7 | +| 6 Communication between gateways ..... | 8 | +| 6.1 Internet protocol – TCP or UDP..... | 8 | +| 6.2 Gateway facsimile data transfer functions ..... | 8 | +| 7 IFT protocol definition and procedures ..... | 8 | +| 7.1 General ..... | 8 | +| 7.2 IFP packet format ..... | 11 | +| 7.3 TYPE definitions..... | 12 | +| 7.4 The IFP DATA element ..... | 13 | +| 7.5 Limitation of ITU-T V.21 frame packet size..... | 16 | +| 8 IFP message flow for facsimile modulations up to ITU-T V.17 ..... | 16 | +| 8.1 Data rate management method 1 ..... | 16 | +| 8.2 Data rate management method 2 ..... | 17 | +| 9 IFT over UDP transport ..... | 17 | +| 9.1 IFT over UDP transport using UDPTL protocol: IFT/UDPTL/UDP..... | 17 | +| 9.2 IFT over UDP transport using RTP protocol: IFT/RTP/UDP..... | 19 | +| 10 Message flow for ITU-T V.8 signals and Annex F of ITU-T V.34 facsimile..... | 21 | +| 10.1 ITU-T V.8 negotiation..... | 21 | +| 10.2 ITU-T V.34 data rate management..... | 22 | +| 10.3 Facsimile mode..... | 24 | +| 10.4 Compatibility with equipment conforming to prior versions of this
Recommendation ..... | 26 | +| 11 Security considerations ..... | 26 | +| Annex A – ASN.1 notation ..... | 27 | +| A.1 ITU-T T.38 (2002) ASN.1 notation ..... | 27 | +| A.2 ITU-T T.38 (1998) ASN.1 notation ..... | 28 | +| Annex B – ITU-T H.323 call establishment procedures..... | 31 | +| B.1 Introduction ..... | 31 | +| B.2 Communication between facsimile terminal and gateway ..... | 31 | +| B.3 Communication between gateways ..... | 31 | +| Annex C – The optional forward error correction scheme for UDPTL..... | 38 | +| C.1 Overview of the optional forward error correction mechanism ..... | 38 | + +| | Page | +|---------------------------------------------------------------------------------------------------------------|-------------| +| C.2 Parity encode/decode scheme operation and characteristics ..... | 38 | +| Annex D – SIP/SDP call establishment procedures..... | 43 | +| D.1 Introduction ..... | 43 | +| D.2 Communication between gateways ..... | 43 | +| Annex E – ITU-T H.248.1 call establishment procedures ..... | 72 | +| E.1 Introduction ..... | 72 | +| E.2 Communication between gateways ..... | 72 | +| Annex F – Interworking procedures: ITU-T T.38 and ITU-T V.150.1 in the same gateway.. | 83 | +| F.1 Introduction ..... | 83 | +| F.2 SSE reason identifier codes for ITU-T T.38 transition ..... | 84 | +| F.3 Mode override from ITU-T V.34 Group 3 facsimile to standard Group 3
facsimile ..... | 85 | +| F.4 External signalling..... | 86 | +| Annex G – ITU-T H.245 capability definition for ITU-T T.38 over RTP ..... | 87 | +| Annex H – Signalled and provisioned ITU-T T.38 protocol parameters..... | 90 | +| H.1 Introduction ..... | 90 | +| H.2 Transport conditional ITU-T T.38 parameters ..... | 90 | +| H.3 Guidelines for signalling ITU-T T.38 protocol parameters..... | 96 | +| H.4 Legacy Interpretation of SDP Parameters ..... | 96 | +| Appendix I – Session examples ..... | 97 | +| I.1 Session examples..... | 97 | +| I.2 IAF device ..... | 101 | +| Appendix II – Examples of call establishment procedures described in Annex B of
ITU-T T.38 ..... | 104 | +| II.1 Sequence examples of call establishment procedures ..... | 104 | +| II.2 Protocol data used in call establishment procedures ..... | 108 | +| Appendix III – ITU-T H.248 call establishment procedure examples for facsimile-capable
media gateways..... | 114 | +| III.1 Introduction ..... | 114 | +| III.2 Examples of call set-up ..... | 114 | +| Appendix IV – ITU-T V.34 session examples..... | 143 | +| IV.1 ITU-T V.34 session examples ..... | 143 | +| Appendix V – ITU-T T.38 implementation guidelines..... | 154 | +| V.1 General issue ..... | 154 | +| V.2 IAF issues ..... | 157 | +| V.3 Call set-up issues ..... | 158 | +| V.4 Others ..... | 158 | + +| | Page | +|--------------------------------------------------------------------------|-------------| +| Appendix VI – Security considerations from a historical perspective..... | 160 | +| VI.1    Historical origin and use of Recommendation ITU-T T.38 ..... | 160 | +| VI.2    Application vs network/transport level security ..... | 161 | +| Bibliography..... | 163 | + + + +# Recommendation ITU-T T.38 + +# Procedures for real-time Group 3 facsimile communication over IP networks + +# 1 Scope + +This Recommendation defines the procedures to be applied to allow Group 3 facsimile transmission between terminals where, in addition to the PSTN or ISDN, a portion of the transmission path used between terminals includes an IP network, e.g., the Internet. + +# 2 Normative references + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T E.180] Recommendation ITU-T E.180/Q.35 (1998), *Technical characteristics of tones for the telephone service.* +- [ITU-T F.185] Recommendation ITU-T F.185 (1998), *Internet facsimile: Guidelines for the support of the communication of facsimile documents.* +- [ITU-T G.711] Recommendation ITU-T G.711 (1988), *Pulse code modulation (PCM) of voice frequencies.* +- [ITU-T G.729] Recommendation ITU-T G.729 (2007), *Coding of speech at 8 kbit/s using conjugate-structure algebraic-code-excited linear prediction (CS-ACELP).* +- [ITU-T H.225.0] Recommendation ITU-T H.225.0 (2003), *Call signalling protocols and media stream packetization for packet-based multimedia communication systems.* +- [ITU-T H.245] Recommendation ITU-T H.245 (2009), *Control protocol for multimedia communication.* +- [ITU-T H.248.1] Recommendation ITU-T H.248.1 (2013), *Gateway control protocol, Version 3.* +- [ITU-T H.248.2] Recommendation ITU-T H.248.2 (2013), *Gateway control protocol: Facsimile, text conversation and call discrimination packages.* +- [ITU-T H.323] Recommendation ITU-T H.323 (2003), *Packet-based multimedia communications systems.* +- [ITU-T Q.850] Recommendation ITU-T Q.850 (1998), *Usage of cause and location in the Digital Subscriber Signalling System No. 1 and the Signalling System No. 7 ISDN user part.* +- [ITU-T Q.931] Recommendation ITU-T Q.931 (1998), *ISDN user-network interface layer 3 specification for basic call control.* +- [ITU-T T.4] Recommendation ITU-T T.4 (2003), *Standardization of Group 3 facsimile terminals for document transmission.* + +- [ITU-T T.6] Recommendation ITU-T T.6 (1988), *Facsimile coding schemes and coding control functions for Group 4 facsimile apparatus.* +- [ITU-T T.30] Recommendation ITU-T T.30 (2005), *Procedures for document facsimile transmission in the general switched telephone network.* +- [ITU-T T.37] Recommendation ITU-T T.37 (1998), *Procedures for the transfer of facsimile data via store-and-forward on the Internet.* +- [ITU-T T.66] Recommendation ITU-T T.66 (2002), *Facsimile code points for use with Recommendations V.8 and V.8 bis.* +- [ITU-T V.8] Recommendation ITU-T V.8 (2000), *Procedures for starting sessions of data transmission over the public switched telephone network.* +- [ITU-T V.21] Recommendation ITU-T V.21 (1988), *300 bits per second duplex modem standardized for use in the general switched telephone network.* +- [ITU-T V.33] Recommendation ITU-T V.33 (1988), *14 400 bits per second modem standardized for use on point-to-point 4-wire leased telephone-type circuits.* +- [ITU-T V.34] Recommendation ITU-T V.34 (1998), *A modem operating at data signalling rates of up to 33 600 bit/s for use on the general switched telephone network and on leased point-to-point 2-wire telephone-type circuits.* +- [ITU-T V.150.1] Recommendation ITU-T V.150.1 (2003), *Modem-over-IP networks: Procedures for the end-to-end connection of V-series DCEs.* +- [ITU-T V.152] Recommendation ITU-T V.152 (2010), *Procedures for supporting voice-band data over IP networks.* +- [ITU-T V.153] Recommendation ITU-T V.153 (12/2009), *Interworking between ITU-T T.38 and ITU-T V.152 using IP peering for real-time facsimile services.* +- [ITU-T X.420] Recommendation ITU-T X.420 (1999) | ISO/IEC 10021-7:2003, *Information technology – Message Handling Systems (MHS): Interpersonal Messaging System.* +- [ITU-T X.680] Recommendation ITU-T X.680 (2002) | ISO/IEC 8824-1:2002, *Information technology – Abstract Syntax Notation One (ASN.1): Specification of basic notation.* +- [ITU-T X.691] Recommendation ITU-T X.691 (2002) | ISO/IEC 8825-2:2002, *Information technology – ASN.1 encoding rules: Specification of Packed Encoding Rules (PER).* +- [IETF RFC 768] IETF RFC 768 (1980), *User Datagram Protocol.* +- [IETF RFC 791] IETF RFC 791 (1981), *Internet Protocol – DARPA Internet Program – Protocol Specification.* +- [IETF RFC 793] IETF RFC 793 (1981), *Transmission Control Protocol – DARPA Internet Program – Protocol Specification.* +- [IETF RFC 1006] IETF RFC 1006 (1987), *ISO transport services on top of the TCP: Version 3.* +- [IETF RFC 2198] IETF RFC 2198 (1997), *RTP Payload for Redundant Audio Data.* +- [IETF RFC 2327] IETF RFC 2327 (1998), *SDP: Session Description Protocol.* +- [IETF RFC 3261] IETF RFC 3261 (2002), *SIP: Session Initiation Protocol.* + +- [IETF RFC 3264] IETF RFC 3264 (2002), *An Offer/Answer Model with Session Description Protocol (SDP)*. +- [IETF RFC 3550] IETF RFC 3550 (2003), *RTP: A Transport Protocol for Real-Time Applications*. +- [IETF RFC 4733] IETF RFC 4733 (2006), *RTP Payload for DTMF Digits, Telephony Tones and Telephony Signals*. +- [IETF RFC 5109] IETF RFC 5109 (2007), *RTP Payload Format for Generic Forward Error Correction*. +- [IETF RFC 5939] IETF RFC 5939 (2010), *Session Description Protocol (SDP) Capability Negotiation*. +- [IETF RFC 6466] IETF RFC 6466 (2011), *IANA Registration of the 'image' Media Type for the Session Description Protocol (SDP)*. +- [ISO/IEC 8825-2] ISO/IEC 8825-2:2008, *Information technology – ASN.1 encoding rules: Specification of Packed Encoding Rules (PER)*. + +# 3 Definitions + +Unless otherwise noted, the definitions in [ITU-T F.185] shall apply. This Recommendation defines the following terms: + +**3.1 emitting gateway:** The IFP peer which initiates IFT service for a calling G3FE. It initiates a TCP or UDP connection to a receiving gateway to begin an IFT session. + +**3.2 G3 facsimile equipment (G3FE):** In this Recommendation, G3FE refers to any entity which presents a communications interface conforming to [ITU-T T.30], [ITU-T T.4] and, optionally, [ITU-T T.6]. A G3FE may be a traditional G3 facsimile machine, an application with an ITU-T T.30 protocol engine, or any of the other possibilities mentioned in the network model for IP facsimile. + +**3.3 receiving gateway:** The IFP peer which accepts a TCP or UDP connection from an emitting gateway, providing IFT service to a called G3FE. + +**3.4 ITU-T T.38/G3:** In this Recommendation, ITU-T T.38/G3 refers to an ITU-T T.38 endpoint that supports G3FE, but excludes the ITU-T T.30/V.34 procedures. + +**3.5 ITU-T T.38/ITU-T V.34G3:** In this Recommendation, ITU-T T.38/ITU-T V.34G3 refers to an ITU-T T.38 endpoint that supports G3FE and includes the ITU-T T.30/V.34 half-duplex procedures. + +**3.6 ITU-T T.38 transport mode:** The actual *protocol stack* below the ITU-T T.38 protocol layer. There are three main ITU-T T.38 transport modes, labelled as "UDPTL/UDP", "RTP/UDP" and "TPKT/TCP". + +NOTE – There might be variations of an ITU-T T.38 transport mode. E.g., in case of security enhanced ITU-T T.38 transport modes: "UDPTL/DTLS/UDP", "SRTP/UDP" and "TPKT/TLS/TCP". + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations: + +| | | +|-------|---------------------------------| +| ANSam | amplitude-modulated Answer tone | +| CI | Call Indicator (signal) | + +| | | +|---------|---------------------------------------------------------------| +| CM | Call Menu (signal) | +| CJ | Call Menu terminator (signal) | +| DTLS | Datagram Transport Layer Security | +| ECM | Error Correction Mode | +| FD | Facsimile Device | +| FEC | Forward Error Correction | +| FoIP | Facsimile over IP ([ITU-T T.38]) | +| G3FE | Group 3 Facsimile Equipment | +| GW | Gateway | +| IAF | Internet-Aware Fax device | +| IFP | Internet Facsimile Protocol | +| IFT | Internet Facsimile Transfer | +| INFOh | Half duplex INFO sequence | +| IP | Internet Protocol | +| FoIP | Facsimile over IP ([ITU-T T.38]) | +| G3FE | Group 3 Facsimile Equipment | +| GW | Gateway | +| JBIG | Joint Bi-level Image experts Group (ITU-T T.38 coding scheme) | +| JM | Joint Menu (signal) | +| LSB | Least Significant Bit | +| MG | Media Gateway ([ITU-T H.248]) | +| MGC | Media Gateway Controller ([ITU-T H.248]) | +| MoIP | (Data) Modem over IP ([ITU-T V.150.1]) | +| MMR | Modified Modified Read (ITU-T T.38 coding scheme) | +| MPh | [ITU-T V.34] half-duplex Modulation Parameter sequence | +| MSB | Most Significant Bit | +| O/A | (SDP) Offer/Answer | +| OLC | Open Logical Channel | +| RTCP | Real-Time Control Protocol | +| RTP | Real-Time Protocol | +| SDP | Session Description Protocol | +| SDP O/A | SDP Offer/Answer | +| SIP | Session Initiation Protocol | +| SUB | Sub-address | +| TCF | Training Check Function | + +| | | +|--------|------------------------------------------| +| TCP | Transmission Control Protocol | +| TLS | Transport Layer Security | +| TPKT | Transport Protocol Data Unit Packet | +| UDP | User Datagram Protocol | +| UDPTL | Facsimile UDP Transport Layer (protocol) | +| VBD | Voiceband Data | +| VBDolP | Voiceband Data over IP ([ITU-T V.152]) | + +# 5 Introduction + +The availability of IP networks such as the Internet for international communication provides the potential for utilizing this transmission medium in the transfer of Group 3 facsimile messages between terminals. Since the characteristics of IP networks differ from those provided by the PSTN or ISDN, some additional provisions need to be standardized to maintain successful facsimile operation. + +The protocol defined in this Recommendation specifies the messages and data exchanged between facsimile gateways and/or IAFs connected via an IP network. The reference model for this Recommendation is shown in Figure 1. + +This model shows a traditional Group 3 facsimile terminal connected to a gateway emitting a facsimile through an IP network to a receiving gateway which makes a PSTN call to the called Group 3 facsimile equipment. Once the PSTN calls are established on both ends, the two Group 3 terminals are virtually linked. All standard [ITU-T T.30] session establishment and capabilities negotiation is carried out between the terminals. For non-[ITU-T V.34] G3FEs, TCF is either generated locally or transferred between the terminals, depending on the mode of operation to synchronize modulation rates between the gateways and G3FEs. + +An alternate scenario would be a connection to a facsimile-enabled device (for example, a PC) which is directly connected to an IP network. In this case, there is a virtual receiving gateway as part of the device's facsimile-enabling software and/or hardware. In other environments, the roles could be reversed, or there might be two facsimile-enabled network devices. The protocol defined by this Recommendation operates directly between the emitting and receiving gateways. Communication between the gateways and facsimile terminals and/or other devices is outside the scope of this Recommendation. + +The protocol defined in this Recommendation was chosen on the basis of efficiency and economy. For optimum performance, the IP transmission paths should have reasonably low delays to meet the ITU-T F.185 requirements. Good image quality is provided by error control in the network in addition to the means provided by the ITU-T T.30 protocol. + +Reliable data transport is provided in two ways: by using TCP over IP networks, or by using UDP over IP networks with optional means for error control. + +Three call control protocols are supported: [ITU-T H.323], SIP, and [ITU-T H.248]. ITU-T H.323 systems may utilize either method as described in Annex D of [ITU-T H.323]. These environments are being used to support voice transmission over IP as an alternative to the PSTN. Since facsimile generally uses the same facilities as voice communications, it may be desirable to utilize these environments when implementing facsimile over IP. + +![Figure 1: Model for facsimile transmission over IP Networks. The diagram illustrates a three-part system. On the left, 'Calling G3 Facsimile terminal equipment' (a fax machine) is connected via a 'PSTN' line to an 'Emitting gateway' (a server rack). On the right, a 'Receiving gateway' (another server rack) is connected via a 'PSTN' line to 'Called G3 Facsimile terminal equipment' (a fax machine). Both gateways are connected to a central 'IP network' represented by an oval. Additionally, the 'IP network' is connected to an 'Internet-aware fax device' (a smaller fax machine) at the bottom right.](4801720824e4b5e2361a5564f91cfb70_img.jpg) + +Figure 1: Model for facsimile transmission over IP Networks. The diagram illustrates a three-part system. On the left, 'Calling G3 Facsimile terminal equipment' (a fax machine) is connected via a 'PSTN' line to an 'Emitting gateway' (a server rack). On the right, a 'Receiving gateway' (another server rack) is connected via a 'PSTN' line to 'Called G3 Facsimile terminal equipment' (a fax machine). Both gateways are connected to a central 'IP network' represented by an oval. Additionally, the 'IP network' is connected to an 'Internet-aware fax device' (a smaller fax machine) at the bottom right. + +T.38\_F1 + +**Figure 1 – Model for facsimile transmission over IP Networks** + +Under some circumstances, it may be necessary to make some adjustments to the procedures between the gateway and the Group 3 terminal. Any such adjustments should not go beyond those available in the ITU-T T.30 protocol. These adjustments are implementation-dependent. + +The protocol defined in this Recommendation focuses on the interval where a network connection has been established between two peers (gateway or IAF) implementing the real-time facsimile document transfer over Internet protocol. + +Management issues, such as directory services (converting PSTN numbers to IP addresses when required), network hunting, user authentication and CDR (call detail record) collection and network management (SNMP or others) are important but are not addressed in this Recommendation. Standardization of these issues will allow the implementation of a network based on third-party management devices, including sharing such devices with other Internet gateways such as Internet telephony and video, remote access and e-mail. + +In addition, user interface aspects, such as the way that the facsimile operator selects the PSTN number of the destination or identifies himself to the system (for security purposes) are also not in the scope of this Recommendation. However, it is reasonable to assume that the facsimile operator uses the Group 3 terminal equipment keypad (using DTMF signals) or the IAF keyboard to provide the gateway with the required information. + +Some of these issues mentioned here are being addressed in other ITU-T Recommendations and IETF RFCs. Specifically, [ITU-T H.323]/[ITU-T H.225.0], [ITU-T H.248], and SIP and the gatekeeper/call agent Recommendations address some of the above-mentioned dependencies. + +It is intended that all procedures in this Recommendation conform to the requirements of [ITU-T F.185]. + +The main body of this Recommendation describes the protocol and communication procedures between the emitting gateway and the receiving gateway. Communication between the gateways + +and the calling and called G3FEs, as well as call control procedures, are described in Annexes B, D, E and F. + +This Recommendation provides a version number that explicitly defines which syntax and version dependent form of the ASN.1 is supported. This version number is not meant to imply that an ITU-T T.38 device will support a given feature or function, only that it is capable of syntactically parsing the ASN.1 defined in a particular version of [ITU-T T.38]. + +**ITU-T T.38 ASN.1 version numbers** + +| ASN.1 version | Version-dependent content summary | Original documentation | +|----------------------|----------------------------------------------------------|----------------------------------------------------------------------------------------------| +| 0 | 1998 ASN.1 syntax | Initial publication (1998), Amendment 1 (1999), Amendment 2 (02/00) | +| 1 | 1998 ASN.1 syntax, TPKT, IAF support | Amendment 3 (11/00)
NOTE – Some early implementations supporting TPKT indicate version 0. | +| 2 | 2002 ASN.1 syntax | Updated Recommendation (2002) | +| 3 | [ITU-T V.34], [ITU-T V.33] support, 2002 Syntax extended | | +| 4 | Defined defaults for negotiated parameters in Annex D | | + +The ITU-T T.38 version number is a mandatory attribute (see Table B.1) that shall be exchanged between the emitting and receiving gateways. An endpoint shall signal the version that it supports in the ITU-T T.38 version attribute in its offer. The recipient of the offer shall accept that version or modify the version attribute to be an equal or lower version when transmitting an answer to the initial offer. The recipient of an offer shall not respond with an answer containing a higher version than that which was offered. + +Early implementations of ITU-T T.38 equipment may not provide an ITU-T T.38 version number. In receipt of SDP without the version attribute, the endpoint shall assume that the version is 0. Version 0 devices are recommended to explicitly advertise their version. + +## **5.1 Conventions** + +### **5.1.1 SDP offer/answer protocol variants** + +This Recommendation provides example signalling syntax. There are two models for the session description protocol (SDP) concerning the indication and negotiation of media and transport capabilities: + +- The name "legacy SDP Offer/Answer" indicates SDP Offer/Answer, according to [IETF RFC 3264]; +- The name "revised SDP Offer/Answer" indicates SDP Offer/Answer, according to [IETF RFC 5939] and [b-IETF RFC 6871]. + +# **6 Communication between gateways** + +## **6.1 Internet protocol – TCP or UDP** + +The public Internet service provides two principal modes of data transmission: + +- TCP (transmission control protocol) – A session-based, confirmed delivery service; +- UDP (user datagram protocol) – Datagram service, non-confirmed delivery. + +This Recommendation allows the use of either TCP or UDP depending on the service environment. It defines a layered protocol such that the ITU-T T.38 messages exchanged for TCP and UDP implementations are identical. + +## **6.2 Gateway facsimile data transfer functions** + +The emitting gateway shall demodulate the ITU-T T.30 transmission received from the calling terminal. The ITU-T T.30 facsimile control and image data shall be transferred in an octet stream structure using the IFP packets, over a transport protocol (TCP or UDP). The following signals are not transferred between gateways but are generated or handled locally between the gateway and the G3FE: CNG, CED, and in one mode, TCF. The gateways may indicate the detection of the tonal signals CNG and CED so that the other gateway can generate them. + +The receiving gateway shall decode the transferred information and establish communication with the called facsimile terminal using normal ITU-T T.30 procedures. The receiving gateway shall forward all relevant responses from the called terminal to the emitting gateway. + +The facsimile data transfer structure is described in clause 7.1.3. The flow between gateways is described in clause 8. + +### **6.2.1 Treatment of non-standard facilities requests** + +The emitting gateway may optionally ignore NSF, NCS and NSS, take appropriate action or pass the information to the receiving gateway. The receiving gateway may optionally ignore NSF, NCS and NSS or take appropriate action, including passing the information to the receiving G3FE. Information in other frames related directly to these frames may be altered by the gateway. + +# **7 IFT protocol definition and procedures** + +## **7.1 General** + +This clause contains the textual description of the IFT protocol. The IFT protocol is specified by the ASN.1 description in Annex A. In the case of a conflict between the ASN.1 and the text, the ASN.1 governs. The ASN.1 encoding in Annex A should employ the BASIC-ALIGNED version of packed encoding rules (PER) according to [ITU-T X.691]. + +### **7.1.1 Bit and octet transmission order** + +Transmission order is as defined in [IETF RFC 791] "Internet Protocol", quoted herein as reference: + +- The order of transmission of the header and data described in this document is resolved to the octet level. Whenever a diagram shows a group of octets, the order of transmission of those octets is the normal order in which they are read in English. For example, in the following diagram the octets are transmitted in the order they are numbered. + +![Figure 2: Transmission order of octets. A diagram showing four octets labeled 0, 1, 2, and 3. Each octet contains bits 0 through 9. The bits are arranged in a grid: Octet 0 has bits 0-9; Octet 1 has bits 0-9; Octet 2 has bits 0-9; Octet 3 has bits 0-9. The bits are numbered 0 to 12 in a specific order: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg) + +Figure 2: Transmission order of octets. A diagram showing four octets labeled 0, 1, 2, and 3. Each octet contains bits 0 through 9. The bits are arranged in a grid: Octet 0 has bits 0-9; Octet 1 has bits 0-9; Octet 2 has bits 0-9; Octet 3 has bits 0-9. The bits are numbered 0 to 12 in a specific order: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12. + +**Figure 2 – Transmission order of octets (based on [IETF RFC 791], Figure 10)** + +- Whenever an octet represents a numeric quantity, the left most bit in the diagram is the high order or most significant bit. That is, the bit labelled 0 is the most significant bit. For example, the following diagram represents the value 170 (decimal). + +![Figure 3: Significance of bit. A diagram showing a single octet with bits 0 through 7. The bits are arranged in a row: 0, 1, 2, 3, 4, 5, 6, 7. The bits are numbered 0 to 7 in a specific order: 0, 1, 2, 3, 4, 5, 6, 7.](8307f6b04df072c9332f9987e034272c_img.jpg) + +Figure 3: Significance of bit. A diagram showing a single octet with bits 0 through 7. The bits are arranged in a row: 0, 1, 2, 3, 4, 5, 6, 7. The bits are numbered 0 to 7 in a specific order: 0, 1, 2, 3, 4, 5, 6, 7. + +**Figure 3 – Significance of bit (based on [IETF RFC 791], Figure 11)** + +- Similarly, whenever a multi-octet field represents a numeric quantity, the left most bit of the whole field is the most significant bit. When a multi-octet quantity is transmitted, the most significant octet is transmitted first. + +### 7.1.2 Mapping of the ITU-T T.30 bit stream + +The ITU-T T.30 bit stream is mapped so that *bit* order is maintained between the PSTN and IP networks. This means that the first bit transmitted is stored in the MSB of the first octet, where the MSB is defined as in clause 7.1.1. + +### 7.1.3 IFP packet layers for TCP/IP and UDP/IP + +The IFP packets described in clause 7.2 are combined with the appropriate headers for TCP/IP and UDP/IP as shown in Figures 4, 5 and 6. In Figure 4, the UDPTL header represents the additional header information required for error control over UDP. The TPKT header defined in [IETF RFC 1006] shall precede the IFP packet in TCP implementations as shown in Figure 4. Implementations using TPKT shall set the version to 1 or higher. Version 0 implementations shall not use TPKT. + +![Figure 4: High-level TCP/TPKT/IP packet structure. The diagram shows two models of packet structure. Model a) Layered model of IFP/TCP/IP packet: A diagram showing the layered structure of the packet. It consists of an IP header, followed by an IP payload. The IP payload is further divided into a TCP header and a TCP payload. The TCP payload is further divided into a TPKT header and an IFP packet. Model b) Flat model of IFP/TCP/IP protocol: A diagram showing the flat structure of the packet. It consists of a single row of four fields: IP header, TCP header, TPKT header, and IFP packet.](90ee16ccc0ad16aeca48087797d7b07f_img.jpg) + +a) Layered model of IFP/TCP/IP packet + +b) Flat model of IFP/TCP/IP protocol + +Figure 4: High-level TCP/TPKT/IP packet structure. The diagram shows two models of packet structure. Model a) Layered model of IFP/TCP/IP packet: A diagram showing the layered structure of the packet. It consists of an IP header, followed by an IP payload. The IP payload is further divided into a TCP header and a TCP payload. The TCP payload is further divided into a TPKT header and an IFP packet. Model b) Flat model of IFP/TCP/IP protocol: A diagram showing the flat structure of the packet. It consists of a single row of four fields: IP header, TCP header, TPKT header, and IFP packet. + +T.38(15)\_F04 + +**Figure 4 – High-level TCP/TPKT/IP packet structure** + +For the UDP transport, IFP data may be encapsulated in UDPTL, as shown in Figure 5, or alternatively encapsulated in RTP, as shown in Figure 6. + +In Figure 5, the UDPTL header represents the additional header information required for error control over UDP. When UDPTL encapsulation is used, the payload structure is as defined in Annex A for UDPTLPacket. + +![Figure 5: High-level UDPTL/UDP/IP packet structure. (a) Layered model of IFP/UDPTL/UDP/IP packet: A diagram showing three nested boxes. The outermost box is 'IP header' followed by 'IP payload'. Inside 'IP payload' is a box for 'UDP header' followed by 'UDP payload'. Inside 'UDP payload' is a box for 'UDPTL header' followed by 'UDPTL payload = IFP packet + redundancy/FEC'. (b) Flat model of IFP/UDPTL/UDP/IP protocol: A single horizontal bar divided into four segments: 'IP header', 'UDP header', 'UDPTL header', and 'IFP packet + redundancy/FEC'. T.38(15)_F05](ff7ce44f3fdd51bae7b231f34df07c6a_img.jpg) + +**a) Layered model of IFP/UDPTL/UDP/IP packet** + +**b) Flat model of IFP/UDPTL/UDP/IP protocol** + +T.38(15)\_F05 + +Figure 5: High-level UDPTL/UDP/IP packet structure. (a) Layered model of IFP/UDPTL/UDP/IP packet: A diagram showing three nested boxes. The outermost box is 'IP header' followed by 'IP payload'. Inside 'IP payload' is a box for 'UDP header' followed by 'UDP payload'. Inside 'UDP payload' is a box for 'UDPTL header' followed by 'UDPTL payload = IFP packet + redundancy/FEC'. (b) Flat model of IFP/UDPTL/UDP/IP protocol: A single horizontal bar divided into four segments: 'IP header', 'UDP header', 'UDPTL header', and 'IFP packet + redundancy/FEC'. T.38(15)\_F05 + +**Figure 5 – High-level UDPTL/UDP/IP packet structure** + +RTP encapsulation of ITU-T T.38 facsimile signals may only be used if both gateways negotiate this capability during call set-up. This negotiation is described in Annexes B, D and E, or Annex D of [ITU-T H.323]. With RTP encapsulation, the optional redundancy and FEC mechanisms described in [IETF RFC 2198] and [IETF RFC 5109] may be used. + +Figure 6 represents the packet structure when optional RTP encapsulation is used. Within an RTP packet, an IFP packet may be optionally combined with a redundant IFP packet [IETF RFC 2198] or with an FEC packet ([IETF RFC 5109] and [IETF RFC 2198]). Another valid [IETF RFC 5109] option, not shown in Figure 6, allows FEC packets to be sent as a separate RTP stream rather than being combined with IFP packets into RTP packets. The RTP payload corresponds to a single IFP packet when [IETF RFC 2198] is not used to combine it with a redundant IFP packet or with an FEC packet. + +![Figure 6: High-level RTP/UDP/IP packet structure. (a) Layered model of IFP/RTP/UDP/IP: A diagram showing three nested boxes. The outermost box is 'IP header' followed by 'IP payload'. Inside 'IP payload' is a box for 'UDP header' followed by 'UDP payload'. Inside 'UDP payload' is a box for 'RTP header' followed by 'RTP payload = IFP packet + redundancy*/FEC**'. (b) Flat model of IFP/RTP/UDP/IP: A single horizontal bar divided into four segments: 'IP header', 'UDP header', 'RTP header', and 'IFP packet + redundancy*/FEC**'. T.38(15)_F06](9cd90f495b95ad2116ff780248c26d95_img.jpg) + +**a) Layered model of IFP/RTP/UDP/IP** + +**b) Flat model of IFP/RTP/UDP/IP** + +T.38(15)\_F06 + +Figure 6: High-level RTP/UDP/IP packet structure. (a) Layered model of IFP/RTP/UDP/IP: A diagram showing three nested boxes. The outermost box is 'IP header' followed by 'IP payload'. Inside 'IP payload' is a box for 'UDP header' followed by 'UDP payload'. Inside 'UDP payload' is a box for 'RTP header' followed by 'RTP payload = IFP packet + redundancy\*/FEC\*\*'. (b) Flat model of IFP/RTP/UDP/IP: A single horizontal bar divided into four segments: 'IP header', 'UDP header', 'RTP header', and 'IFP packet + redundancy\*/FEC\*\*'. T.38(15)\_F06 + +\* = Redundancy per [IETF RFC 2198] + \*\* = FEC per [IETF RFC 5109] + +**Figure 6 – High-level RTP/UDP/IP packet structure** + +## 7.2 IFP packet format + +In the following discussion, a message is the protocol or data information transferred in one direction from a G3FE to or from a gateway during a single period. It may include, for example, one or more HDLC frames, or a "page" of Phase C data. Messages may be sent across the IP network in multiple packets. The packets may, for example, contain partial or full, singular or multiple HDLC frames. Support for multiple packets is provided in this protocol. The DATA element uses fields to support partial and full HDLC frames. + +IFP operates (listens) over TCP/IP or UDP/IP using a port determined during call set-up. All communication between IFP peers is done using packets, identified as IFP packets. + +Table 1 summarizes the IFP packets (for full explanation, refer to the following subclauses). + +**Table 1 – IFP packet elements** + +| Field | Description | +|-------|-------------------| +| TYPE | Type of message | +| DATA | Dependent on TYPE | + +### 7.2.1 ITU-T T.38 packet + +The ITU-T T.38 packet element provides an alert for the start of a message. It is used by the IFP peer to verify message alignment. It is identified by an ASN.1 application tag. When data is read by the peer from its TCP/IP or UDP/IP stack, and the expected tag is not present, the session should be immediately aborted by the receiver. + +### 7.2.2 TYPE + +The TYPE element describes the function of, and optionally the data of, the packet. The legitimate TYPEs are given in Table 2. Each TYPE is separately explained in the following subclauses. The table also indicates whether the TYPEs are Mandatory or Optional for implementations using TCP and UDP. + +If the TYPE element is not recognized, it and the related data element shall be ignored. + +**Table 2 – IFP packet TYPE field** + +| TYPE | DATA Type | Mandatory | Description | +|--------------------------------------------------------------------------------------------------------------------------------------------------|-----------|-----------|-----------------------------------------------------------------------------------------------------------------| +| ITU-T T30_INDICATOR | Regular | Yes | Carries indication about the presence of a facsimile signal (CED/CNG), preamble flags or modulation indications | +| ITU-T T30_DATA | Field | Yes | ITU-T T.30 HDLC Control and Phase C data (e.g., ITU-T T.4/ITU-T T.6 image segment) | +| NOTE – If both G3FE devices are identified via DIS/DCS exchange as Internet-aware fax (IAF) devices, the use of ITU-T T30_INDICATOR is optional. | | | | + +### 7.2.3 DATA-Field + +The DATA-Field element contains the ITU-T T.30 HDLC control data and the Phase C image (or BFT) data. The structure of the DATA-Field is defined in clause 7.4. The structure carries the modulation data as well as indicators for the end of an HDLC frame, the status of the frame check sequence (FCS) for an HDLC frame, and whether the data represents the end of a message. + +## 7.3 TYPE definitions + +The following clauses describe the message TYPEs. + +### 7.3.1 T30\_INDICATOR + +The T30\_INDICATOR TYPE is used by the gateways to indicate the detection of signals such as CED, HDLC preamble flags, and modem modulation training. It is sent by the receiving gateway to the emitting gateway, and by the emitting gateway to the receiving gateway. The use of this message is mandatory, except in the case where both G3FE devices are identified via DIS/DCS exchange as Internet-aware fax devices. A peer may send this message in order to notify its peer about upcoming messages. The T30\_INDICATOR TYPE has one of the following values (see Table 3): + +**Table 3 – Listing of T30\_INDICATOR values** + +| Signal/Indication | +|---------------------------------------------| +| No signal | +| CNG (1100 Hz) | +| CED (2100 Hz) | +| ITU-T V.21 preamble | +| ITU-T V.27 2400 modulation training | +| ITU-T V.27 4800 modulation training | +| ITU-T V.29 7200 modulation training | +| ITU-T V.29 9600 modulation training | +| ITU-T V.17 7200 modulation short training | +| ITU-T V.17 7200 modulation long training | +| ITU-T V.17 9600 modulation short training | +| ITU-T V.17 9600 modulation long training | +| ITU-T V.17 12 000 modulation short training | +| ITU-T V.17 12 000 modulation long training | +| ITU-T V.17 14 400 modulation short training | +| ITU-T V.17 14 400 modulation long training | +| ITU-T V.8 ANSam signal | +| ITU-T V.8 signal | +| ITU-T V.34-cntl-channel-1200 | +| ITU-T V.34-pri-channel | +| ITU-T V.34-CC-retrain | +| ITU-T V.33 12 000 modulation training | +| ITU-T V.33 14 400 modulation training | +| ITU-T V.34-pri-channel | +| ITU-T V.34-CC-retrain | +| ITU-T V.33 12 000 modulation training | +| ITU-T V.33 14 400 modulation training | + +"No signal" indicator may be sent whenever there is no signal in TDM input. For example, it may be used when the modem is changed from [ITU-T V.21] to [ITU-T V.17], or from [ITU-T V.17] to [ITU-T V.21] one. + +NOTE – It is the responsibility of the gateway receiving the indicator to properly generate the appropriate analogue signal, including, for example, the ON-OFF cadence, and to terminate it appropriately. + +### 7.3.2 T30\_DATA TYPE + +The T30\_DATA TYPE is used to indicate that the packet contains data in the DATA element and what modulation was used to carry the data. The T30\_DATA TYPE is used to indicate HDLC control data, Phase C data ([ITU-T T.4]/[ITU-T T.6] or other) and, whenever ITU-T V.34 modulation is used, the ITU-T V.8 control signal data and ITU-T V.34 control and primary channel data. + +It has the following values (see Table 4): + +**Table 4 – Listing of T30\_DATA values** + +| Modulation | +|----------------------------| +| ITU-T V.21 Channel 2 | +| ITU-T V.27 ter 2400 | +| ITU-T V.27 ter 4800 | +| ITU-T V.29 7200 | +| ITU-T V.29 9600 | +| ITU-T V.17 7200 | +| ITU-T V.17 9600 | +| ITU-T V.17 12 000 | +| ITU-T V.17 14 400 | +| ITU-T V.8 | +| ITU-T V.34-pri-rate | +| ITU-T V.34-CC-1200 | +| ITU-T V.34-Pri-Ch | +| ITU-T V.33 12 000 | +| ITU-T V.33 14 400 | + +NOTE – If both G3FE devices are identified via DIS/DCS exchange as IAF devices, T30\_DATA values shall be ignored. + +## 7.4 The IFP DATA element + +The DATA Element of the IFP packets contains the data from the PSTN connections and some indication of the data format. The DATA element is a structure containing one or more Fields. Each Field has two parts: the first part indicates the Field-Type; the second part contains the Field-Data. The meanings for the Field-Type are shown in Table 5. + +**Table 5 – Field-Type and Field-Data description** + +| Field-Type | Field-Type description | +|---------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| HDLC data | Data transmitted over the PSTN connection as HDLC. This includes the ITU-T T.30 control messages as well as Phase C data sent using ECM. | +| | The Field-Data that follows contains some, or all, of a single HDLC data frame starting with the address frame of the HDLC frame, up to but not including FCS. Bit stuffing is removed from all data. The end of a frame is indicated by the FCS field. The gateway is responsible for bit stuffing, FCS generation and separating frames with one or more flag (0x7E) when sending the HDLC data to a G3FE. | +| HDLC-Sig-End | Indicates that the HDLC power level has dropped below the turnoff threshold. There is no Field-Data with this Field-Type. This field type can be used during ITU-T V.34 operation for terminating control channel at the end of a session. | +| HDLC-FCS-OK | Indicates the end of an HDLC frame and that the proper FCS was received. It also indicates that this frame is not the final frame. There is no Field-Data with this Field-Type. | +| HDLC-FCS-Bad | Indicates the end of an HDLC frame and that the proper FCS was not received. It also indicates that this frame is not the final frame. There is no Field-Data with this Field-Type. | +| HDLC-FCS-OK-Sig-End | Indicates the end of an HDLC frame and that the proper FCS was received. In non- ITU-T V.34 mode, it also indicates that ITU-T V.21 modulation should terminate. In ITU-T V.34 mode, flags shall be sent following the frame. There is no Field-Data with this Field-Type. | +| HDLC-FCS-BAD-Sig-End | Indicates the end of an HDLC frame and that the proper FCS was not received and transmission should terminate. It also indicates that this frame is the final frame. There is no Field-Data with this Field-Type. | +| ITU-T T.4-Non-ECM | ITU-T T.4 Phase C data that is not sent using ECM or TCF data in the case of Method 2 of rate adaptation. It also indicates that this is not the end of the Phase C data. | +| | The Field-Data that follow are the demodulated Phase C data, including fill bits and RTC. | +| ITU-T T.4-Non-ECM-Sig-End | ITU-T T.4 phase C data that is not sent using ECM or TCF data in the case of Method 2 of rate adaptation. It also indicates that this is the end of the Phase C data. | +| | The Field-Data that follow are the demodulated Phase C data, including fill bits and RTC. | +| cm-message | The data of the CM signal is translated into the facsimile application profile (see Table 8). | +| | The Field-Data is a single IA5 character of the profile number in Table 8. For example, a "1" indicates Profile 1. | + +**Table 5 – Field-Type and Field-Data description** + +| Field-Type | Field-Type description | +|-------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| jm-message | Response to the cm-message as defined in clause 10.1. | +| | The Field-Data is an IA5 character string of length two octets. The first character is "A" if it is an ACK, or "N" if it is a nACK. The second character is "0" if the first character is "A" and the appropriate nACK value as shown in Table 9. For example, nACK(1) is represented as "N1". | +| ci-message | Data transmitted in the ITU-T V.8 CI signal is mapped to an IA5 character. | +| | The Field-Data that follows contains the IA5 character octet of either "4" or "5" based on the decode of bits 6-8 of the CI call function bits. Note that b8 is the MSB and b6 the LSB. | +| ITU-T V.34-rate | Indicates the negotiated primary channel data signalling rate between receiving gateway and receiving G3FE. | +| | The Field-Data is an IA5 character string of length three octets – the two least significant digits are always 0 and not represented. The first octet after the ITU-T V.34-pri-rate field type is the most significant digit of the data rate (e.g., "024" represents 2400 bit/s). (Note that the rate of 2400 bit/s between receiving gateway and receiving G3FE is disallowed due to possible symbol-rate mismatch.) | + +Multiple fields can appear in a single IFP DATA Element. The example below shows two HDLC frames arranged in a single DATA Element. + +| Field-Type | HDLC-Data | FCS-OK | HDLC-Data | FCS-OK-Sig-End | +|------------------------|-----------------------------------------------------------------------------------------|-----------------------------------------------------|-------------------|--------------------------------------------------| +| Field part description | First HDLC frame. The HDLC octets with zero stuffing and FCS removed in the Field-Data. | Indicates end of HDLC frame and more data to follow | Second HDLC frame | Indicates end of HDLC frame and end of HDLC data | + +NOTE – When the Field-Type DATA element is received, the receiver should analyse it by examining each field separately. If the receiver does not recognize a certain Field-Type of the field it is examining, the entire field shall be skipped, and the receiver shall continue with the next field. + +The IFP peer may elect to send the message data in several packets. Although relatively large packets may be sent, smaller data packets are recommended. It is entirely up to the emitting gateway to decide on the size of packets being sent. The xx-Sig-End Field-Types indicate the end of the message data. Note that for each packet sent, the whole header is repeated. + +A message with zero length data field may be sent to indicate, as early as possible, that T30\_DATA messages are coming. Alternately, the appropriate T30\_INDICATOR signal for high speed could be sent. Implementations shall support both methods. + +Partial HDLC frames are also supported. The next example shows how two HDLC frames would be transmitted using three consecutive IFP packets. (Data transport headers are not shown.) + +| TYPE
element | DATA element | | | | | | | | | +|--------------------|--------------------------|---------------------------|-----------------|-----------------|------------------------------------------|-----------------|-----------------|-----------------|-----------------| +| | Field-Type:
HDLC Data | HDLC
Address
(0xff) | HDLC
Control | HDLC
Octet 1 | HDLC
Octet 2 | HDLC
Octet 3 | HDLC
Octet 4 | HDLC
Octet 5 | HDLC
Octet 6 | +| ITU-T
V.21 Data | Field-Type:
HDLC Data | HDLC
Octet 7 | HDLC
Octet 8 | HDLC
Octet 9 | Field-
Type
FCS-OK | | | | | +| ITU-T
V.21 Data | Field-Type:
HDLC Data | HDLC
Address
(0xff) | HDLC
Control | HDLC
Octet 1 | Field-
Type
FCS-
OK-Sig-
End | | | | | + +## 7.5 Limitation of ITU-T V.21 frame packet size + +To reduce the gateway processing delay, the use of smaller ITU-T V.21 frame data packets is more beneficial for interconnected gateways to flexibly perform jitter buffer adjustment according to the network situation and compatibility of the facsimile terminal. + +The maximum ITU-T V.21 packet size shall be 7 bytes, except for IAF devices. Larger ITU-T V.21 frames shall be sent in multiple packets. + +NOTE – The implementation that conforms to the 2005 and the previous versions of this Recommendation may not limit the size. + +# 8 IFP message flow for facsimile modulations up to ITU-T V.17 + +The gateways follow the ITU-T T.30 message flow and use the packet format in clause 7 to transmit these messages. This means, for example, that error correction in ECM mode is done between the sending G3FE and the receiving G3FE. The PPS, PPR, etc., signals are sent between the end G3FE devices. In another example, negotiation of security keys, etc., as proscribed in Annex H of [ITU-T T.30] is done between the end G3FE devices. Examples of typical message flows are shown in Appendix I. + +There are two methods of handling the TCF signal for determining the high-speed data rate. Either of these methods ensures that both PSTN facsimile sessions be conducted at the same speed. + +## 8.1 Data rate management method 1 + +Method 1 of data rate management requires that the TCF training signal be generated locally by the receiving gateway. Data rate management is performed by the emitting gateway based on training results from both PSTN connections. + +Method 1 is used for TCP implementations and is optional for UDP implementations. + +When a confirmation to receive (CFR) or a failure to train (FTT) is received from a G3FE at the receiving gateway, an ITU-T T.30 HDLC packet (indicating CFR or FTT respectively) should be forwarded to the emitting gateway. + +Based on the results of a TCF received from a G3FE and the ITU-T T.30 HDLC packet (CFR or FTT) forwarded from a receiving gateway, an emitting gateway shall transmit FTT or CFR according to Table 6. + +**Table 6 – Decision table of signalling rate of an emitting gateway** + +| ITU-T T.30 signal message forwarded from receiving gateway | TCF signal received from a G3FE at emitting gateway | Signal to be transmitted to G3FE (emitter) | +|-------------------------------------------------------------------|------------------------------------------------------------|---------------------------------------------------| +| CFR | Success | CFR | +| FTT | Success | FTT | +| CFR | Failure | FTT | +| FTT | Failure | FTT | + +In the case where the emitting device is an Internet-aware fax (IAF) device and there is no emitting gateway, the IAF device shall respond to FTTs from the receiving gateway with appropriate DCS responses, including possibly modulation changes. + +In the case where the Receiving Device is an IAF device and there is no receiving gateway, the IAF device shall respond to DCS from the emitting gateway with CFR, but shall be prepared for a DCS if the emitting gateway generates an FTT. + +In the case where the emitting device and the receiving device are IAF devices, the emitting device shall send DCS with the modulation bits set to 0, and the receiving device shall respond with CFR. The data rate over the IP network is established during call set-up. + +## **8.2 Data rate management method 2** + +Data rate management method 2 requires that the TCF be transferred from the sending G3FE to the receiving G3FE rather than having the receiving gateway generate it locally. Speed selection is done by the G3FEs in the same way as they would on a regular PSTN connection. + +In the case where the emitting device is an Internet-aware fax (IAF) device and there is no emitting gateway, the IAF device shall respond to FTTs from the receiving gateway with appropriate DCS + TCF responses, including possibly modulation changes. + +In the case where the receiving device is an IAF device and there is no receiving gateway, the IAF device shall respond to DCS from the emitting gateway with either CFR or FTT, depending upon the received TCF signal. + +In the case where the emitting device and the receiving device are IAF devices, the emitting device shall send DCS with the modulation bits set to 0, and the receiving device shall respond with CFR. The data rate over the IP network is established during call set-up. Data Rate Management Method 2 is mandatory for use with UDP. Method 2 is not recommended either for use with TCP, or for the case where both G3FE devices are identified via DIS/DCS exchange as IAF devices. + +# **9 IFT over UDP transport** + +## **9.1 IFT over UDP transport using UDPTL protocol: IFT/UDPTL/UDP** + +### **9.1.1 Overview of UDPTL protocol** + +In the following discussion, a packet is regarded as a block of information which has the overall structure of that presented in clause 7.1.3. + +The layered model in Figure 5-a may be visualised more simply (Figure 5-b) in a flat space which allows packets to be regarded as a composite of headers plus the IFP payload. It is the IFP payload which is used to convey facsimile related information between gateways; all other information should be regarded as overhead necessary for the safe transportation and interpretation of + +IFP messages as described in clause 7. This clause describes the UDPTL payload. Descriptions of the IP and UDP headers and payloads are found in [IETF RFC 791] and [IETF RFC 768], respectively. + +UDPTL packets comprise a sequence number and a variable length, octet aligned, payload. + +UDPTL packets are based upon the principle of framing. Each packet may contain one or more IFP packets in its payload section. The first packet in any payload is always formatted in accordance with the specifications of clause 7, and must correspond to the sequence number supplied in the header (for instance, the first field in a payload with sequence number 15 must have been generated 5 payloads later than the first field in the payload with sequence number 10). The IFP packet in a UDPTL payload is referred to as the "primary". Additional fields may be included in a payload after the primary. These fields are referred to as "secondaries" and may or may not be formatted as per clause 7 specifications depending on their form. + +### 9.1.2 UDPTL header section format + +The UDPTL sequence number is used to identify the sequencing in a payload. + +#### 9.1.2.1 UDPTL sequence number element + +Each packet, and therefore primary field, has its own corresponding unique sequence number which specifies an ordering at the receiving gateway should packets arrive out of sequence. To enable gateways to be synchronized upon receipt of any packet, the first primary field transmitted shall have sequence number zero. Successive primaries shall have linearly increasing (integer adjacent) sequence numbers. + +### 9.1.3 UDPTL payload section format + +During ITU-T H.323 capabilities exchange, a gateway shall indicate its support of the available error protection schemes, parity FEC, or redundancy. Based on these capabilities, a choice may be made on which scheme is used for error protection. If a capability is indicated to receive both parity error correction frames and redundant frames, then either scheme may be used. If, however, a gateway indicates a capability to receive only redundant error protection frames, then the transmitting gateway may not send parity FEC frames. The support of parity FEC is optional; a gateway providing parity FEC receive services should, however, also be capable of receiving redundant messages. A gateway may choose not to send any error correction messages. + +The IFP payload section comprises one or more fields. The basic format of an UDPTL payload is as shown in Figure 7. + +Figure 7 specifies the order in which different messages are to be assembled into the UDPTL payload. It is invalid to transmit both redundant and FEC fields within the same packet. + +![](ceb48bd7cc8cbb0fa401b366532bbdb0_img.jpg) + +| | | | | | | +|--------------------|---------------------------------------|-------------------------------|-------------------------|-----|----------------------------------| +| SEQUENCE
NUMBER | MANDATORY MESSAGE
(PRIMARY) | OPTIONAL REDUNDANT
MESSAGE | OR | ... | OPTIONAL
REDUNDANT
MESSAGE | +| | | n packets | OPTIONAL FEC
MESSAGE | | OPTIONAL FEC
MESSAGE | + +**Figure 7 – Basic format of UDPTL payload section (UDP header not shown)** + +#### 9.1.3.1 UDPTL FEC message format + +An FEC contains a parity-encoded representation of a number of primaries. The number of primary IPF packets represented by an FEC field is given by the fec-n-packets element of the UDPTLPacket. + +### 9.1.4 IFP/UDP facsimile data transfer functions + +#### 9.1.4.1 Use of redundancy messages + +Each primary contains an IFP packet. As packets, and therefore primaries, are assigned unique and linearly increasing sequence numbers, receiving gateways can detect packet loss and re-sequencing requirements. By imposing a simple structure, it is possible to provide error recovery by means of transmitting redundant information in the form of prior primary packets within each payload. The strategy used is to assemble additional $n$ prior packets after the primary, with monotonically decreasing sequence numbers. Thus, should each payload contain a primary and two or more secondary fields, a loss of two consecutive UDPTL packets will be protected against. In order to provide a redundancy service in the UDPTL, it is necessary to maintain a buffer of "old" primaries for assembly into new packets. An illustration of such a buffer is provided in Figure 8 to demonstrate by example the principles of redundancy transfer. + +![Diagram illustrating the inclusion of prior (secondary) IFP packets into a UDPTL packet. It shows an IFP Message Store with sequences 41 to 45, where sequence 45 is the primary message and sequences 44, 43, 42, and 41 are redundancy messages. Arrows show these redundancy messages being included in the UDPTL packet structure.](4cde160bcc69b7b6c81b648dd0e4252e_img.jpg) + +The diagram illustrates the structure of a UDPTL packet and how it incorporates redundancy from an IFP Message Store. At the top, a horizontal bar represents the UDPTL packet structure, divided into four sections: 'SEQUENCE NUMBER ( 45 )', 'PRIMARY MESSAGE', 'REDUNDANCY MESSAGE 1', and 'REDUNDANCY MESSAGE n'. Below this, a table represents the 'IFP Message Store'. + +| Sequence | IFP Message Store | +|----------|-------------------| +| 45 | IFP MESSAGE | +| 44 | IFP MESSAGE | +| 43 | IFP MESSAGE | +| 42 | IFP MESSAGE | +| 41 | IFP MESSAGE | + +Arrows indicate the flow of data from the IFP Message Store to the UDPTL packet structure. An arrow points from the 'IFP MESSAGE' at sequence 45 to the 'PRIMARY MESSAGE' field. Another arrow points from the 'IFP MESSAGE' at sequence 44 to the 'REDUNDANCY MESSAGE 1' field. A third arrow points from the 'IFP MESSAGE' at sequence 41 to the 'REDUNDANCY MESSAGE n' field. The label 'T.38\_F8' is located at the bottom right of the diagram. + +Diagram illustrating the inclusion of prior (secondary) IFP packets into a UDPTL packet. It shows an IFP Message Store with sequences 41 to 45, where sequence 45 is the primary message and sequences 44, 43, 42, and 41 are redundancy messages. Arrows show these redundancy messages being included in the UDPTL packet structure. + +**Figure 8 – Including prior (secondary) IFP packets (fields) into a UDPTL packet** + +Note that the UDPTL scheme is only capable of transmitting a block of redundant IFP packets whose sequence numbers are contiguous. Thus, if the current IFP packet has sequence number $C$ and it is desired to redundantly transmit the IFP packet from UDPTL packet sequence number $C-2$ , then the UDPTL packet must contain all the IFP packets from $C$ , $C-1$ , $C-2$ in the given order. + +Gateways need not be capable of transmitting redundant packets. Receiving gateways may ignore them. + +## 9.2 IFT over UDP transport using RTP protocol: IFT/RTP/UDP + +For UDP transport, the RTP protocol ([IETF RFC 3550]) may be used as an alternative to UDPTL. The RTP protocol is used when both gateways negotiate this capability during call set-up. This negotiation is described in Annexes B and D. + +Additional capabilities available to RTP streams may optionally be used as long as these are negotiated by both gateways. These include redundancy ([IETF RFC 2198]) and FEC ([IETF RFC 5109]). + +There are a few differences which must be considered when using RTP instead of UDPTL. These differences result from differences in the payload format and operational procedures for RTP and UDPTL. Along with the similarities between these formats, these differences are highlighted in Table 7. + +**Table 7 – Similarities and differences between RTP and UDPTL** + +| Feature | UDPTL mechanism | RTP mechanism | +|----------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Payload format | UDPTLPacket specified in Annex A | Without redundancy and FEC, RTP payload is a single IFP packet.
When FEC packets constitute a separate stream ([IETF RFC 5109]), the RTP payload is a single IFP packet.
With [IETF RFC 2198]-based redundancy, the RTP payload structure is as specified in [IETF RFC 2198].
With FEC that uses [IETF RFC 2198] encapsulation, the RTP payload structure is as specified in [IETF RFC 5109] and [IETF RFC 2198]. | +| Negotiation necessary to use RTP or UDPTL protocol | In order to be used, the UDPTL-based ITU-T T.38 capability must be proposed by one gateway and selected/accepted by the other gateway. The capability declaration and negotiation procedures are per Annexes B, D, and E, or Annex D of [ITU-T H.323]. | In order to be used, the RTP-based ITU-T T.38 capability must be proposed by one gateway and selected/accepted by the other gateway. The capability declaration and negotiation procedures are per Annexes B, D and E of ITU-T T.38, or Annex D of [ITU-T H.323]. | +| Payload sequencing | UDPTL sequence number | RTP sequence number | +| Redundancy | Uses mechanism defined in clause 9 | [IETF RFC 2198] | +| FEC | Uses mechanism defined in Annex C | [IETF RFC 5109], with or without [IETF RFC 2198] encapsulation | + +Each RTP packet starts with a fixed RTP header. The following describes the payload specific fields of the RTP fixed header when the RTP packet encapsulates fax: + +- Payload type (PT): The payload type for fax is a dynamic payload type identified by the name "t38". If redundancy is used per [IETF RFC 2198], the payload type must indicate the payload format RED (as per [IETF RFC 2198]). +- Marker (M) bit: The marker bit is not used for fax and MUST be set to zero. The Marker bit should be ignored by the receiver of the packet. + +# 10 Message flow for ITU-T V.8 signals and Annex F of ITU-T V.34 facsimile + +## 10.1 ITU-T V.8 negotiation + +[ITU-T V.8] is used as a means to negotiate capabilities of facsimile and modem devices. This includes the modulations and the applications supported by the devices. During the negotiation procedure the ANSam, CI, CM, JM and CJ signals are interchanged between the calling and called G3FEs. The CM and JM signals are compelled end-to-end in order to fully verify a matching application or capability set. In the ITU-T T.38 reference configuration, the CM information received by the emitting gateway from the calling G3FE is transferred to the receiving gateway that then uses it appropriately (possibly modifying it) and transmits it to the receiving G3FE. The receiving G3FE in response, transmits its JM signal to the receiving gateway. The receiving gateway then passes the information (again modifying it if necessary) to the emitting gateway, that in turn, transmits it to the calling G3FE. Once the emitting gateway has the JM information, it has full knowledge of the connection capabilities. + +At the initiation of a call, the ANSam signal begins the ITU-T V.8 exchange for both ITU-T V.34 facsimile and ITU-T V.8-based modems. Call initiation in a multimode gateway, including ITU-T V.8-based modems and ITU-T V.34 G3FEs, is described in Annex F. + +This clause describes the handling of ANSam and the ITU-T V.8 exchange for call initiation in facsimile-only gateways as well as for supporting ITU-T V.34 turn-around polling (see clause 10.3.5) and re-starting ITU-T V.34 in manual mode (see clause 10.3.6). + +ANSam shall be detected by the receiving gateway and generated by the emitting gateway. When ANSam is detected by the receiving gateway, it shall be reported using the **v8-ansam** indicator if the emitting gateway is ITU-T V.34 capable. If the emitting gateway is not ITU-T V.34 capable, the receiving gateway shall report ANSam using the **ced t30**-indicator. + +In the event that there is a timeout in response to an ANSam generated by the emitting gateway, resulting in an ITU-T V.21 response, either gateway may elect to prevent a possible return to ITU-T V.8 negotiations by resetting the ITU-T V.8 bit of the DIS message (bit 6, first octet). + +An emitting gateway shall report the facsimile application profile (FAP) to the receiving gateway when it has detected two identical/consecutive CM signals, and has verified that the call function category octet contains a facsimile function. If the call function is not a valid facsimile value, then the call can be terminated as being a non-supported call type. The profile is transmitted to the receiving gateway using the **cm-message** data Field-Type, where it is regenerated for transmission to the receiving G3FE. + +The facsimile application profile contains a base profile number. The base profile represents the contents of the call function and modulation modes of the ITU-T V.8 CM signal. Table 8 shows the six possible valid facsimile profiles. + +**Table 8 – List of valid facsimile profiles** + +| Description | ITU-T V.8 identifying code-points | Profile No. | +|-------------------------------------------------|----------------------------------------------------------------------------|-------------| +| G3 Facsimile Terminal:
(Sending Facsimile) | Call Function = 4
Modulation = ITU-T V.17, V.29, V.27 ter , V.21 | 1 | +| G3 Facsimile Terminal:
(Receiving Facsimile) | Call Function = 5
Modulation = ITU-T V.17, V.29, V.27 ter , V.21 | 2 | + +**Table 8 – List of valid facsimile profiles** + +| Description | ITU-T V.8 identifying code-points | Profile No. | +|--------------------------------------------------------------------|--------------------------------------------------------------------------------------|-------------| +| ITU-T V.34 HDX and G3
Facsimile Terminal: (Sending Facsimile) | Call Function = 4
Modulation = ITU-T V.34 HDX, V.17, V.29, V.27 ter , V.21 | 3 | +| ITU-T V.34 HDX and G3
Facsimile Terminal: (Receiving Facsimile) | Call Function = 5
Modulation = ITU-T V.34 HDX, V.17, V.29, V.27 ter , V.21 | 4 | +| ITU-T V.34 HDX-only Facsimile Terminal: (Sending Facsimile) | Call Function = 4
Modulation = ITU-T V.34 HDX-only | 5 | +| ITU-T V.34 HDX-only Facsimile Terminal: (Receiving Facsimile) | Call Function = 5
Modulation = ITU-T V.34 HDX-only | 6 | + +The receiving gateway shall transmit an acknowledgement (ACK) when it has received two identical/consecutive JM signals, and has determined that the profile being requested by the emitting gateway is acceptable to the remote terminal. The receiving gateway shall transmit a negative acknowledgement (NAK) to the emitting gateway if the profile is not acceptable. The value of the NAK depends upon the JM response. See Table 9. + +**Table 9 – Negative acknowledgement (NAK) message to invalid profiles** + +| | | +|--------|---------------------------------------------------------------| +| NAK(0) | No compatible mode available | +| NAK(1) | No ITU-T V.34 fax, use G3 fax – Response for profiles 1 and 2 | +| NAK(2) | ITU-T V.34 fax only. Response for profiles 5 and 6 | + +Upon completion of the ITU-T V.8 signalling, the emitting and receiving gateways shall proceed with the appropriate modulation specified, as indicated by the **jm-message** response. + +## 10.2 ITU-T V.34 data rate management + +The two gateways shall independently proceed with phase 2 and phase 3 of ITU-T V.34 half-duplex handshake as described in clause 12 of [ITU-T V.34]. + +To prevent the overflow of data from the calling terminal (calling G3FE) being transmitted to the answering terminal (receiving G3FE), the primary channel data signalling rate of the calling G3FE/emitting gateway terminal-gateway pair shall be less than, or equal to, the primary channel data signalling rate of the receiving gateway/receiving G3FE terminal gateway pair. Preference is to ensure that the rates are equal and the fastest compatible rate is selected. When the calling G3FE/emitting gateway rate is less than that of the receiving gateway/receiving G3FE rate and the data is arriving at a rate slower than is being transmitted to the receiving G3FE terminal, gaps may be filled with HDLC flags between frames. Note that the only possibility for avoiding a data signalling rate incompatibility is by the receiving gateway disallowing a data rate of 2400 bit/s. Once an ITU-T T.30 session has begun, data rate changes shall be managed to preserve these requirements. + +### 10.2.1 Control channel start-up + +Control channel start-up can occur after training of the primary channel, or after sending data in the primary channel (ITU-T T.30 Phase C), if there is no request to change the primary channel data rate via a control channel retrain. + +The control channel rate shall be 1200 bit/s. Support for control channel rate of 2400 bit/s is for further study. + +The data rate shall be negotiated in the control channel start-up or control channel retrain of the ITU-T V.34 half-duplex handshake. The emitting gateway shall be responsible for the correct selection of the data rates for the primary channel of the G3FEs. It is not necessary to constrain the equipment at both ends to the same symbol rate. The emitting gateway, once trained up, shall exchange HDLC flags in the control channel until it receives the primary channel signalling rate of the receiving gateway/receiving G3FE pair via the **v34-pri-rate** message. Once the emitting gateway has information of both its own negotiated data rate and the data rate selected by the receiving gateway/receiving G3FE pair, the emitting gateway shall determine if it must change the primary channel rate between itself and the calling G3FE, using a control channel retrain with a modified MPh. The local rate parameter shall be set to a value that is less than or (preferably) equal to the receiving G3FE value. Once the rate selection criteria has been met, the receiving gateway and the emitting gateway can pass on the ITU-T T.30 DIS, DCS signals, etc., as normal. If the ITU-T T.30 messages such as DIS are received from the receiving gateway while a control channel retrain is in progress between the emitting gateway and the calling G3FE, the emitting gateway shall buffer the incoming message and delay transmission of the ITU-T T.30 messages until the rate selection and negotiation procedure is completed. Once completed, DIS, etc., can be transmitted from the emitting gateway to the calling G3FE. + +### 10.2.2 Control channel retrain + +Once an ITU-T T.30 session is established (i.e., after T.30 Phase B has started with the exchange of DIS), the primary channel data rate can be changed between pages or between partial pages via control channel retrain. Either the sending G3FE or the receiving G3FE can initiate a data rate change by sending **AC**. A control channel retrain from the G3FEs can be signalled using the **v34-CC-retrain** indicator. A gateway may initiate a retrain sequence at an appropriate time in response to this indicator. The retrain sequence can cause a MPh exchange between a gateway and a G3FE, resulting in a new data signalling rate for the primary channel. + +When a control channel retrain occurs in an attempt to change the primary channel data rate, the requirement to prevent data overflow, as defined in clause 10.2, shall be preserved. Either the calling G3FE or the receiving G3FE may initiate a data rate change request, leading to two main cases to consider. For each case, the rate may increase or decrease. The behaviour for each case is defined below: + +- Retrain initiated by the calling G3FE + - In this case, no signals are sent from the emitting gateway to the receiving gateway. + - a) The calling G3FE requests a rate increase. + - If the rate request would result in the calling G3FE rate to be greater than the rate between the receiving gateway and the receiving G3FE, the emitting gateway shall not allow the rate increase, else it may allow it. + - b) The calling G3FE requests a rate decrease. + - The emitting gateway may change the rate as requested. +- Retrain initiated by the receiving G3FE + - In this case, the receiving gateway shall send the **v34-CC-retrain** indicator, followed by the **v34-pri-rate** message with the new data rate that is selected. + +- a) The receiving G3FE requests a rate increase. + +The receiving gateway may change the rate as requested. The emitting gateway may, at an appropriate time, initiate a control-channel retrain with the sending G3FE, and increase the data rate of the calling G3FE if it is less than or equal to the new rate of the receiving G3FE. + +- b) The receiving G3FE requests a rate decrease. + +The receiving gateway may change the rate as requested. If the new rate indicated by the **v34-pri-rate** message is less than the calling G3FE rate, the emitting gateway shall, at the appropriate time, initiate a control-channel retrain with the sending G3FE and decrease the primary channel data rate of the calling G3FE so that it is less than or equal to the new rate of the receiving G3FE. + +Note that a control channel retrain may be initiated at any time when the control channel is active. One appropriate time for the emitting gateway to initiate the required retrain is after the post-page message exchange but before the start-up of the primary channel. + +## 10.3 Facsimile mode + +### 10.3.1 Control channel + +Control channel data exchange begins after the MPh exchanges are complete and the parameters for the control channel rate and the primary channel rate have been agreed. + +The control channel is a full duplex channel that, unlike the non-ITU-T V.34 fax modes, sends flags in the absence of data (compared to silence for the non-ITU-T V.34 modes). It is the responsibility of the gateway or IAF to generate flags as needed during control channel operations. + +Control channel packets are sent using **v34-CC-1200** t30-data "modulation" value with Field-Types of **hdlc-xxx**. + +The **hdlc-xxx-sig-end** Field-Types indicate the end of an HDLC message. Flags shall be sent after this instead of "silence" as in non-ITU-T V.34 operation. + +### 10.3.2 Switch from control channel to primary channel + +The source terminal indicates its intention to shut down the control channel and switch to the primary channel by sending continuous ONEs of at least 40 in number and until it detects that the recipient terminal has stopped sending flags. + +An emitting gateway shall signal a receiving gateway or IAF that it is ready to transition to the primary channel by sending the **v34-primary-channel** indicator. + +### 10.3.3 Primary channel + +Annex F of [ITU-T T.30] requires that all image data be sent using ECM. This means that primary channel data shall be sent in packets using **v34-primary-channel** Data Value and Field-Types of **hdlc-xxx**. + +In the case where the calling G3FE/emitting gateway primary rate is less than that of the receiving gateway/receiving G3FE rate, causing the data to arrive at a rate slower than is being transmitted to the receiving G3FE, HDLC flags shall be used to fill between frames. + +### 10.3.4 Switch from primary channel to control channel + +The emitting gateway shall send the **v34-control-channel-1200** indicator after the primary channel turn-off sequence is complete. After receiving the **v34-control-channel-1200** indicator, the receiving gateway shall initiate the turn-off of the primary channel between it and the called G3FE. + +If a change in the primary channel bit rate is not desired, the control channel starts up per clause 10.3.1. If a change in primary channel bit rate is desired, the **v34-CC-retrain** t30-indicator is sent per clause 10.2.2 instead of the **v34-control channel** t30-indicator. + +### 10.3.5 Turn-around polling mode + +Turn-around polling is accomplished by shutting down the control channel after a DTC command and initiating a ITU-T V.8 exchange with CM (ANSam is not used). The source terminal (calling G3FE) indicates its intention to do turn-around polling by sending DTC and sends flags until continuous ONEs are detected. After the ONEs are detected, the source terminal is quiet for 70 ms and then initiates CM. The receiving terminal indicates its intention to shut down the control channel and switch to ITU-T V.8 exchange by sending continuous ONEs of at least 40 in number and until it detects that the source terminal has stopped sending flags. + +Turn-around polling shall be supported between the calling G3FE and the receiving G3FE as follows. + +The receiving gateway shall detect the ITU-T T.30 DTC signal. After receiving DTC, the receiving gateway shall prepare to detect continuous ONEs from the receiving G3FE. Upon detection of continuous ONEs, it shall send the **v8 indicator** to the emitting gateway. + +The emitting gateway, after receiving the **v8 indicator** from the receiving gateway, shall send continuous ONEs to the emitting G3FE until the G3FE stops sending flags. The emitting gateway will then shut down the control channel, and prepare to receive the CM message from the emitting G3FE device. Upon receipt of the CM message, it shall forward the facsimile application profile (FAP) to the receiving gateway using the **cm-message**. + +The receiving gateway, upon detecting turn-off of the control channel from the receiving G3FE, shall go quiet until it receives the facsimile application profile. Upon receiving the profile, it shall send the appropriate CM to the receiving G3FE. + +The emitting gateway shall transmit an (ACK or nACK) to the receiving gateway after it has received two identical JM signals from the emitting G3FE, as described in clause 10.1. The operation is identical to normal ITU-T V.8 negotiation except the emitting and receiving gateways switch behaviour. + +### 10.3.6 Manual entry into Annex F of ITU-T V.34 operation + +Manual entry into ITU-T V.34 is accomplished by the calling G3FE responding with CI to a DIS from the receiving G3FE with bit 6 set to 1. The receiving G3FE responds to CI with ANSam, thus initiating the normal ITU-T V.8 sequence described in clause 10.1. + +To support manual entry, the emitting gateway shall be capable of detecting CI after sending DIS in non-ITU-T V.34 mode. If CI is received in response to DIS, the emitting gateway shall send a **ci-message** to the receiving gateway, and prepare to receive the **V.8ANSam** signal in response. + +When the receiving gateway, operating in non-ITU-T V.34 mode, receives the **ci-message**, it shall regenerate the CI signal to the receiving G3FE, and prepare to receive ANSam from it. + +### 10.3.7 Disconnect + +At the end of a call, a gateway shall indicate the end of the control channel with the **hdlc-xxx-sig-end** or the **no-sig** indicator to the remote gateway. + +## 10.4 Compatibility with equipment conforming to prior versions of this Recommendation + +An ITU-T T.38 device conforming to earlier versions of ITU-T T.38 (ASN.1 versions 0, 1, 2) will not be able to interpret some messages added to enable ITU-T V.34 capability. This generally should not present a problem because the gateways should discover during the call set-up exchange what their respective capabilities are, including what version of ITU-T T.38 is supported. (For example, see Annexes B, D and E). The following table shows the possible combinations and the resulting compatibility. + +| Emitting gateway ITU-T V.34 HDX capable | Receiving gateway ITU-T V.34 HDX capable | Comment | +|------------------------------------------------|-------------------------------------------------|-------------------------------------------| +| No | No | Standard ITU-T T.38 | +| No | Yes | Fallback to Standard ITU-T T.38 | +| Yes | No | Fallback to Standard ITU-T T.38 | +| Yes | Yes | ITU-T V.34 HDX ITU-T T.38 procedures used | + +A non-ITU-T V.34 (ITU-T V.8) facsimile device will not recognize the amplitude modulation or phase reversals on an ANSam signal and will treat the signal as CED. An ITU-T T.38 device conforming to earlier versions of this Recommendation will not be able to understand the T30\_INDICATOR V.8 ANSam signal. + +An ITU-T T.38 device conforming to this version of ITU-T T.38 shall only send signals defined in previous versions of ITU-T T.38 to another device conforming to previous versions of ITU-T T.38. An ITU-T T.38 device detecting a T30\_INDICATOR V.8 ANSam signal shall map this signal into a T30\_INDICATOR CED signal before sending it to an ITU-T T.38 device indicating version 0, 1, or 2 capability. An ITU-T T.38 gateway conforming to version 3 of ITU-T T.38 may not advertise ITU-T V.8 capability or respond to ITU-T V.8 handshake with an external facsimile device when interoperating with a version 0, 1, or 2 ITU-T T.38 device. + +# 11 Security considerations + +See Appendix VI for security considerations from a historical perspective. + +# Annex A + +## ASN.1 notation + +(This annex forms an integral part of this Recommendation.) + +## A.1 ITU-T T.38 (2002) ASN.1 notation + +``` +T38 DEFINITIONS AUTOMATIC TAGS ::= +BEGIN +``` + +``` +IFPPacket ::= SEQUENCE +{ + type-of-msg Type-of-msg, + data-field Data-Field OPTIONAL +} +``` + +``` +Type-of-msg ::= CHOICE +{ + t30-indicator ENUMERATED + { + no-signal, + cng, + ced, + v21-preamble, + v27-2400-training, + v27-4800-training, + v29-7200-training, + v29-9600-training, + v17-7200-short-training, + v17-7200-long-training, + v17-9600-short-training, + v17-9600-long-training, + v17-12000-short-training, + v17-12000-long-training, + v17-14400-short-training, + v17-14400-long-training, + ..., + v8-ansam, + v8-signal, + v34-cntl-channel-1200, + v34-pri-channel, + v34-CC-retrain, + v33-12000-training, + v33-14400-training + }, +``` + +``` +t30-data ENUMERATED +{ + v21, + v27-2400, + v27-4800, + v29-7200, + v29-9600, + v17-7200, + v17-9600, + v17-12000, + v17-14400, + ..., + v8, +``` + +``` + + v34-pri-rate, + v34-CC-1200, + v34-pri-ch, + v33-12000, + v33-14400 + } +} + +Data-Field ::= SEQUENCE OF SEQUENCE +{ + field-type ENUMERATED + { + hdlc-data, + hdlc-sig-end, + hdlc-fcs-OK, + hdlc-fcs-BAD, + hdlc-fcs-OK-sig-end, + hdlc-fcs-BAD-sig-end, + + t4-non-ecm-data, + t4-non-ecm-sig-end, + ..., + cm-message, + jm-message, + ci-message, + v34rate + }, + + field-data OCTET STRING (SIZE(1..65535)) OPTIONAL +} + +UDPTLPacket ::= SEQUENCE +{ + seq-number INTEGER (0..65535), + primary-ifp-packet TYPE-IDENTIFIER.&Type(IFPPacket), + error-recovery CHOICE + { + secondary-ifp-packets SEQUENCE OF TYPE-IDENTIFIER.&Type(IFPPacket), + + fec-info SEQUENCE + { + fec-npackets INTEGER, + fec-data SEQUENCE OF OCTET STRING + } + } +} +END + +``` + +## A.2 ITU-T T.38 (1998) ASN.1 notation + +``` + +T38 DEFINITIONS AUTOMATIC TAGS ::= +BEGIN +IFPPacket ::= SEQUENCE +{ + type-of-msg Type-of-msg, + data-field Data-Field OPTIONAL +} + +``` + +``` + +Type-of-msg ::= CHOICE +{ + t30-indicator ENUMERATED + { + no-signal, + cng, + ced, + v21-preamble, + v27-2400-training, + v27-4800-training, + v29-7200-training, + v29-9600-training, + v17-7200-short-training, + v17-7200-long-training, + v17-9600-short-training, + v17-9600-long-training, + v17-12000-short-training, + v17-12000-long-training, + v17-14400-short-training, + v17-14400-long-training, + ... + }, + data ENUMERATED + { + v21, + v27-2400, + v27-4800, + v29-7200, + v29-9600, + v17-7200, + v17-9600, + v17-12000, + v17-14400, + ... + } +} +Data-Field ::= SEQUENCE OF SEQUENCE +{ + field-type ENUMERATED + { + hdlc-data, + hdlc-sig-end, + hdlc-fcs-OK, + hdlc-fcs-BAD, + hdlc-fcs-OK-sig-end, + hdlc-fcs-BAD-sig-end, + t4-non-ecm-data, + t4-non-ecm-sig-end + }, + field-data OCTET STRING (SIZE (1..65535)) OPTIONAL +} +UDPTLPacket ::=SEQUENCE +{ + se-NUMBER INTEGER (0..65535), + primary-ifp-packet TYPE-IDENTIFIER.&Type(IFPPacket), + error-recovery CHOICE + +``` + +``` + + { + secondary-ifp-packets SEQUENCE OF TYPE-IDENTIFIER.&Type(IFPPacket), + fec-info SEQUENCE + { + fec-npackets INTEGER, + fec-data SEQUENCE OF OCTET STRING + } + } +} +END + +``` + +# **Annex B** + +## **ITU-T H.323 call establishment procedures** + +(This annex forms an integral part of this Recommendation.) + +## **B.1 Introduction** + +This annex describes system level requirements and procedures for Internet-aware facsimile implementations and Internet-aware facsimile gateways conforming to this Recommendation to establish calls with other ITU-T T.38 implementations including those using the procedures defined in this annex as well as Annex D of [ITU-T H.323]. + +## **B.2 Communication between facsimile terminal and gateway** + +Communication between a sending Group 3 facsimile terminal and the incoming gateway is generally effected using dial-up procedures over the PSTN. Basic and optional ITU-T T.30 procedures are supported. + +The gateway may receive the facsimile transmission from the calling terminal as a modem signal on the PSTN if the gateway supports a direct dial-in procedure. Where the gateway is located within the network, it may receive the transmission in the form of a PCM-encoded digital channel. Internet-aware facsimile (IAF) implementations are connected directly to the IP network and act as a gateway for call establishment. + +### **B.2.1 Transfer of addressing information** + +The conveyance of the ITU-T E.164 address of the called terminal from the calling terminal to the emitting gateway may be by manual procedures using prompts, by means of double dialling, or by any other suitable means. In addition, there are some applications which may benefit from placing the destination ITU-T E.164 address in the IRA (Internet routing address)/ISP (Internet selective polling) signals, as described in [ITU-T T.30]. + +## **B.3 Communication between gateways** + +### **B.3.1 Overview** + +#### **B.3.1.1 Call set-up** + +Call set-up for ITU-T T.38 Annex B compliant implementations is based on the fast connect procedure defined in [ITU-T H.323]. ITU-T T.38 implementations may operate in two distinct ITU-T H.323 compatible environments. + +- 1) A facsimile-only over IP environment. In this environment, no voice support is provided. The procedures and requirements of this annex shall apply to implementations operating in this environment unless they are superseded by implementation of ITU-T H.323 Annex D. +- 2) A facsimile and voice over IP environment. Implementations in this environment shall use the methods described in Annex D of [ITU-T H.323]. + +ITU-T T.38 Annex B implementations shall use the fast connect procedure for call set-up and shall not initiate ITU-T H.245 negotiation. However, ITU-T T.38 Annex B devices shall support ITU-T H.245 when the remote device is not an ITU-T T.38 Annex B device or otherwise needs to start ITU-T H.245. + +#### **B.3.1.2 Media channels** + +Annex D of [ITU-T H.323] requires that ITU-T T.38 facsimile packets are sent on a separate TCP/UDP port from ITU-T H.225.0 call signalling. All required ports are usually established during the initial **fastStart** exchange. A minimal ITU-T T.38 Annex B implementation requires a TCP port for call signalling and either a UDP port for UDPTL, or two UDP ports for RTP (one for RTP and one for RTCP), or a TCP port for ITU-T T.38 facsimile information. + +#### **B.3.1.3 Usage of ITU-T H.245** + +Endpoints conforming to this annex are required to support [ITU-T H.245], but shall not initiate communication over the ITU-T H.245 control channel. Rather, ITU-T T.38 Annex B devices shall only transmit ITU-T H.245 messages over the ITU-T H.245 control channel after first either receiving a TCS message or a request to establish a separate ITU-T H.245 control channel. ITU-T T.38 Annex B devices shall advertise ITU-T T.38 support in the initial TCS message that it sends and it should indicate support for ITU-T G.711 in order to be interoperable with the broadest range of ITU-T H.323 devices. + +NOTE – Previous versions of this annex specified that devices shall only support fast connect procedures, so it is important for interoperability with older devices that newer devices do not initiate ITU-T H.245 communication unless the other device first initiates ITU-T H.245 communication. + +### **B.3.2 Basic call set-up** + +ITU-T H.323 implementations have a multi-phase call set-up procedure, which includes: + +- RAS (registration, admissions and status) signalling using UDP between the endpoint and the gatekeeper. +- ITU-T H.225.0 call signalling either directly between endpoints, or between endpoints and gatekeeper depending on the call model in use, using TCP/IP. +- ITU-T H.245 capability negotiation and logical channel management using TCP/IP, with messages either tunnelled within the ITU-T H.225.0 call signalling channel or transmitted via a separate TCP/IP connection. + +Although support for RAS is mandatory, an ITU-T H.323 endpoint is not required to use RAS unless a gatekeeper is present in the network and willing to provide service to the endpoint. Thus, an Annex B implementation could be used with or without a gatekeeper. It could obtain its IP addresses in any fashion desired, such as LDAP or a personal directory. However, if placed in a gatekeeper environment, it would register and operate as per [ITU-T H.323]. + +Implementations conforming to this annex shall conform to ITU-T H.323 RAS signalling. RAS signalling allows an ITU-T T.38 implementation to initiate a call, using the ITU-T H.323 well-known TCP port, and provides dynamic assignment of the port to use for the ITU-T T.38 messages. + +Implementations conforming to this annex utilize ITU-T H.323 call set-up messages as described in clause 8.1.1 of [ITU-T H.323]: "Basic call set-up – neither endpoint registered" assuming this to be the case. The initial text of clause 8.1 of [ITU-T H.323]: "Phase A – Call Set-up" is also relevant to ITU-T T.38 implementations. The rest of clause 8.1 of [ITU-T H.323] applies if one or both endpoints are registered with a gatekeeper. + +Implementations conforming to this annex shall initially start calls by opening a TCP/IP session and sending an ITU-T H.225.0 SETUP message with the fast connect fields filled in, as described in clause 8.1.7 of [ITU-T H.323]. + +The receiving terminal replies with an ITU-T H.225.0 ALERTING, CALL PROCEEDING, PROGRESS, or CONNECT message as per the procedures of ITU-T H.323 "fast connect". The + +Annex B implementation may include video, voice, or data OLC elements in the "fastStart" structure, but if present such data types shall follow OLC elements containing facsimile proposal(s). The OLC elements pertinent to facsimile are described in the next clause. + +### B.3.3 Capabilities negotiation + +There are several options that need to be negotiated to determine which options the gateways support and use. See Table B.1. + +**Table B.1 – Gateway option capability support indications** + +| Option | Description | +|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Data rate management method | Method 1: Local generation of TCF is required for use with TCP.
Method 2: Transfer of TCF is required for use with UDP (UDPTL or RTP).
Method 2 is not recommended for use with TCP. | +| Data transport protocol | The emitting gateway may indicate a preference for either UDP/UDPTL, or UDP/RTP, or TCP for transport of ITU-T T.38 IFP packets. The receiving device selects the transport protocol. | +| Fill bit removal | Indicates the capability to remove and insert fill bits in Phase C, non-ECM data to reduce bandwidth in the packet network. Optional. (Note) | +| MMR transcoding | Indicates the ability to convert to/from MMR from/to the line format for increasing the compression of the data and reducing the bandwidth in the packet network. Optional. (Note) | +| JBIG transcoding | Indicates the ability to convert to/from JBIG to reduce bandwidth. Optional. (Note) | +| Maximum buffer size | For UDP (UDPTL or RTP) modes, this option indicates the maximum number of octets that can be stored on the remote device before an overflow condition occurs. It is the responsibility of the transmitting application to limit the transfer rate to prevent an overflow. The negotiated data rate should be used to determine the rate at which data is being removed from the buffer. | +| Maximum datagram size | This option indicates the maximum size of a UDPTL packet or the maximum size of the payload within an RTP packet that can be accepted by the remote device. | +| Version | This is the version number of ITU-T T.38. New versions shall be compatible with previous versions. | +| NOTE – Bandwidth reduction shall only be done on suitable Phase C data, i.e., MH, MR and – in the case of transcoding to JBIG – MMR. MMR and JBIG require reliable data transport such as that provided by TCP. When transcoding is selected, it shall be applied to every suitable page in a call. | | + +These capabilities are negotiated using the OLC elements as defined in the T38faxProfile of [ITU-T H.245] version 7 (or higher). + +Two unidirectional, reliable or unreliable, logical channels (sender to receiver channel and receiver to sender channel) as shown in Figure B.1 or, optionally, one bidirectional reliable channel as shown in Figure B.2 shall be opened for the transfer of ITU-T T.38 packets. ITU-T T.38 packets can be transferred using either TCP or UDP (UDPTL or RTP). In general, the usage of TCP is more effective when the bandwidth for facsimile communication is limited, or for IAF to IAF transfers since TCP provides flow control. On the other hand, the usage of UDP (UDPTL or RTP) may be more effective when the bandwidth for facsimile communication is sufficient. + +![Diagram of a pair of unidirectional channels between Source and Destination. The top channel is labeled 'Sending logical channel' with an arrow pointing from Source to Destination. The bottom channel is labeled 'Receiving logical channel' with an arrow pointing from Destination to Source.](0b7849dae424b0dd33e6386d2384643a_img.jpg) + +T.38\_FB.1 + +Diagram of a pair of unidirectional channels between Source and Destination. The top channel is labeled 'Sending logical channel' with an arrow pointing from Source to Destination. The bottom channel is labeled 'Receiving logical channel' with an arrow pointing from Destination to Source. + +**Figure B.1 – A pair of unidirectional channels** + +![Diagram of a single bidirectional channel between Source and Destination. The top stream is labeled 'Sending stream' with an arrow pointing from Source to Destination. The bottom stream is labeled 'Receiving stream' with an arrow pointing from Destination to Source.](1ab49904e6a60be337d5b75cb7cc8ab7_img.jpg) + +T.38\_FB.2 + +Diagram of a single bidirectional channel between Source and Destination. The top stream is labeled 'Sending stream' with an arrow pointing from Source to Destination. The bottom stream is labeled 'Receiving stream' with an arrow pointing from Destination to Source. + +**Figure B.2 – A single bidirectional channel** + +The sender terminal specifies a TCP/UDP port in the **OpenLogicalChannel** in the **fastStart** element of *Set-up when transmitting ITU-T T.38 via TCP or UDPTL*. The receiver terminal shall provide its TCP (or UDP) port in the **OpenLogicalChannel** of the **fastStart** element as specified by the procedures in clause 8.1.7 of [ITU-T H.323]: "Fast connect". + +The receiver should open the TCP/UDP port based on the preference of the sender. If the sender terminal has a preference for UDP (UDPTL or RTP) or TCP, then it shall provide its preference in the **OpenLogicalChannel** with the appropriate port in the **fastStart** sequence. The receiving terminal can select the transport, TCP or UDP (UDPTL or RTP), by specifying one of the two in **OpenLogicalChannel** structures in the **fastStart** element of *Connect*. + +When transmitting ITU-T T.38 over RTP, the **OpenLogicalChannel** contains the generic audio capability defined in Annex G and shall be included in the **fastStart** element in the Setup message as specified in clause 8.1.7 of [ITU-T H.323]: "Fast Connect". The parameter names in the generic audio capability are named the same as those used in the ITU-T H.245 ASN.1. + +All ITU-T T.38 Annex B implementations shall include a T38fax OLC with **t38FaxUdpOptions** and **transferredTCF** set in the **fastStart** structure. Note that all ITU-T H.323 Annex D devices supporting ITU-T T.38 also are required to include these structures. In addition, ITU-T T.38 Annex B devices should include an OLC with **t38FaxTcpOptions** and **localTCF** set and with **tcp** selected as the **t38FaxProtocol** choice. Optionally, ITU-T T.38 Annex B devices may include an OLC with the T38RTP generic audio capability specified with the **transferredTCF** included in the **fastStart** structure. As described in clause 8.1.7 of [ITU-T H.323], the order in which OLCs are included in the **fastStart** element indicates preference on the part of the sender. The receiver only includes the OLCs that it wishes to use in the **fastStart** element of the CONNECT message or other message containing the **fastStart** element. + +NOTE – In the first version of this annex, it was not possible to use a single bidirectional reliable channel. In order to retain backward compatibility, the endpoint may specify support for bidirectional reliable channels by including the **t38FaxTcpOptions** SEQUENCE and setting the **t38TCPBidirectionalMode** field to TRUE. If the other endpoint does not include the **t38FaxTcpOptions** SEQUENCE, the endpoint shall assume that a single bidirectional reliable channel for ITU-T T.38 is not supported and shall use either two unidirectional reliable or unreliable channels. + +### **B.3.4 Examples of call set-up OLCs** + +The examples in this clause illustrate the OLC elements that are sent in various cases. The rules of clause 8.1.7 of [ITU-T H.323] are followed using OLC definitions in [ITU-T H.245]. Refer to [ITU-T H.245] for the relevant ASN.1. + +#### **B.3.4.1 TCP, UDP (UDPTL), or RTP support** + +The default case requires support for both TCP and UDP (UDPTL). In this case, the sender shall send OLCs for **T38/TCP&localTCF** and **T38/UDPTL&transferredTCF**. Optionally, the sender may send OLCs for **T38RTP&transferredTCF**. If the receiver wishes to use UDP, an OLC for **T38/UDPTL&transferredTCF** is returned. If the receiver wishes to use RTP, an OLC for **T38RTP&transferredTCF** is returned. Otherwise, the OLC for **T38/TCP&localTCF** is returned. + +#### **B.3.4.2 UDP (UDPTL) with data rate management method 1 support** + +For the case where the sender wishes to use data rate management method 1 and UDP (UDPTL) for data transport, it shall send OLCs for **T38/UDPTL&transferredTCF**, **T38/UDPTL&localTCF**, **T38/TCP&localTCF**. If the receiver agrees to use **UDPTL&localTCF**, an OLC for **T38/UDPTL&localTCF** is returned. + +#### **B.3.4.3 RTP with data rate management method 1 support** + +For the case where the sender wishes to use data rate management method 1 and RTP for data transport, it shall send OLCs for **T38RTP&transferredTCF** and **T38RTP&localTCF**. If the receiver agrees to use **RTP&localTCF**, an OLC for **T38RTP&localTCF** is returned. + +### **B.3.5 Mandatory call set-up messages** + +The Annex B implementation shall support the following clauses of [ITU-T H.225.0] for call set-up: + +- Mandatory elements in Table 4 of [ITU-T H.225.0], i.e., ALERTING, CONNECT, CALL PROCEEDING, SETUP, RELEASE COMPLETE, etc., shall be supported by ITU-T T.38 endpoints conforming to Annex B. Note that there is no requirement to send ALERTING if CONNECT, CALL PROCEEDING, or RELEASE COMPLETE is sent within 4 seconds of the receipt of SETUP, as described in [ITU-T H.323]. Note also that gateways shall send CALL PROCEEDING. +- The Information elements of FACILITY, as described in clause 7.4.1 of [ITU-T H.225.0]. +- The Information elements of ALERTING, as described in clause 7.3.1 of [ITU-T H.225.0]. +- The Information elements of CALL PROCEEDING, as described in clause 7.3.2 of [ITU-T H.225.0]. +- The Information elements of CONNECT, as described in clause 7.3.3 of [ITU-T H.225.0]. +- The information elements of PROGRESS, as described in clause 7.3.7 of [ITU-T H.225.0]. +- The Information elements of RELEASE COMPLETE, as described in clause 7.3.9 of [ITU-T H.225.0]. +- The Information elements of SETUP, as described in clause 7.3.10 of [ITU-T H.225.0]. +- The ASN.1 of [ITU-T H.225.0], as described in [ITU-T H.225.0]. + +NOTE – ITU-T H.225.0 ASN.1 supports a large number of optional features. ITU-T T.38 Annex B implementations may implement the full range of optional ITU-T H.225.0 features, including authentication features that are potentially available. They may also implement ITU-T H.450.x supplementary services. ITU-T H.225.0 options are outside (i.e., prior) to the OLC negotiations. If a real time fax endpoint ([ITU-T H.323] Annex D or [ITU-T T.38] Annex B) makes use of ITU-T H.450.x supplementary services, it + +must take into account that the remote endpoint may or may not support them. In the worst case, the supplementary service is ignored by the receiver. Thus the requesting endpoint must handle this condition, with, for example, a timeout mechanism. + +### B.3.6 Mapping of call progress signals + +For call set-up and call progress, the return signals can be simplified to the set shown in Table B.2. These are all returned prior to or instead of a connect message. + +The CONNECT message is returned when the gateway, *by some means*, determines that a connection to the terminal G3FE has been established. If CED or FSK flags are detected, the appropriate ITU-T T.38 messages can be sent. This level of call set-up and progress works in both ITU-T H.323 as well as non-ITU-T H.323 environments. + +**Table B.2 – Call Progress Mapping** + +| Meaning | Mapping/Comments | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------| +| Busy1. Subscriber busy tone as defined in [ITU-T E.180]. | ITU-T Q.850 cause value 17. | +| Busy2. Sometimes referred to as "Distinctive Busy" on some PABX models. | ITU-T Q.850 cause value 17. | +| Congestion busy as defined in [ITU-T E.180]. | ITU-T Q.850 cause value 34. | +| Ring1. Ringing tone as defined in [ITU-T E.180]. This is an intermediate call progress indicator. It can be used to generate a ringback signal to the originating G3FE as if it were an end-to-end PSTN connection. | ALERTING | +| Ring2. Ringing tone similar to Ring1 where two short rings are generated instead of one long ring. This is an intermediate call progress result. | ALERTING | +| SIT intercept. Special information tones are defined in [ITU-T E.180]. Intercept Tone is one combination of tones – frequency and duration. | ITU-T Q.850 cause value 4.
NOTE – SIT tones are not distinguished because they generally indicate a problem with the number to dial. | +| SIT vacant. Special information tones are defined in [ITU-T E.180]. Circuit vacant tone is one combination of tones – frequency and duration. | ITU-T Q.850 cause value 4. | +| SIT reorder. Special information tones are defined in [ITU-T E.180]. Reorder tone is one combination of tones – frequency and duration. | ITU-T Q.850 cause value 4. | +| SIT no circuit. Special information tones are defined in [ITU-T E.180]. No circuit tone is one combination of tones – frequency and duration. | ITU-T Q.850 cause value 4. | + +### B.3.7 Usage of the maxBitRate in messages + +ITU-T T.38 is a data application (UDPTL or TCP) or audio capability (RTP) per [ITU-T H.245]. An ITU-T H.245 OLC requires that the **maxBitRate** field be set. For gateway implementations, this field should indicate the maximum modem rate for the TDM network that is supported by the gateway. The rate for IAF devices is to be defined but shall not be set to zero. Note that the units for **maxBitRate** is 100 bit/s (Note 1). The maxBitRate field shall not be used to negotiate fax transmission rates and is included only as a hint to the called party as to the maximum required bandwidth. + +NOTE 1 – The unit value is different for non-ITU-T H.323 controlled ITU-T T.38 endpoints (see for example Annex H). This implies the correct signalling conversion in the case of an ITU-T T.38 call between two endpoints located in ITU-T H.323 and non-ITU-T H.323 network domains. Also refer to clause H.4.1 for further information on the use of this parameter. + +### **B.3.8 DTMF transmission** + +UserInputIndication as described in Annex D of [ITU-T H.323] is an ITU-T H.245 signal and may be used if the ITU-T H.245 control channel is utilized. Other mechanisms as described in [ITU-T H.323] or [ITU-T H.225.0] may also be employed. + +### **B.3.9 Interoperability** + +Both ITU-T H.323 direct call model and ITU-T T.38 Annex B require a well-known port to initiate call signalling. As described in Appendix IV of [ITU-T H.225.0], the ITU-T H.323 well-known port for call signalling via TCP is 1720. ITU-T T.38 Annex B endpoints should use the ITU-T H.323 well-known port. In order for a single implementation (such as a gateway) to support multiple endpoints, dynamic ports must be used. A facsimile gateway conforming to this annex shall support ITU-T H.323 RAS. + +ITU-T T.38 Annex B implementations shall set **h245Tunnelling** to TRUE in all ITU-T H.225.0 messages. + +# Annex C + +## The optional forward error correction scheme for UDPTL + +(This annex forms an integral part of this Recommendation.) + +## C.1 Overview of the optional forward error correction mechanism + +The parity FEC scheme is symmetrical in that it is identical in both encode and decode modes, and may be computed for an arbitrary number of arbitrarily sized IFP messages. A transmitting gateway generates FEC messages by passing in a number of primary IFP packets; these FEC messages may then be assembled into a packet in accordance with Figure 5. + +Receiving gateways which detect the loss of a primary IFP packet that is covered by an FEC message may be able to reconstruct it by passing in the remaining (received) primary IFP packets and the FEC message itself to the parity encode/decode algorithm. Certain conditions apply in order for a lost primary IFP packet to be recovered using the parity encoder/decoder; these shall be discussed in the following clauses. + +## C.2 Parity encode/decode scheme operation and characteristics + +The parity scheme accepts a number of arbitrarily sized IFP messages. It aligns them vertically and zero pads the shorter length messages to produce a 2D matrix as shown in Figure C.1 a). A one-bit piece-wise sum is then performed on a column by column basis (equivalent to exclusive OR logic function) across the width of the matrix, each summation resulting in a binary digit. This process is illustrated in Figure C.1 b). The output from the parity scheme is the row of resulting binary data. + +The basic error recovery scheme works by assuming that 1 loss in $n$ packets may occur. If the $(n + 1)^{\text{th}}$ packet contains an FEC message generated from the primary IFP packets of the $n$ preceding packets, then provided no more than one of the first $n$ packets is lost, any missing IFP message can be reconstructed. The generation and reconstruction of primary IFP packets using the parity scheme outlined above is described in the following clauses. + +![Figure C.1: Illustration of Length normalization and Parity function operation. The diagram is divided into two parts: (a) Length normalization example and (b) Parity function application. Part (a) shows three input frames of different lengths being normalized to a common length of 16 bits. Part (b) shows the same three frames being processed by a column-based binary sum (XOR) operation to produce a 16-bit resulting output.](c1df61cc3717e878a48e530218403403_img.jpg) + +**a) Length normalization example** + +Input frame 1: 0 1 0 0 1 1 1 0 1 0 0 0 1 0 1 1 + +Input frame 2: 1 0 1 1 1 0 0 0 1 + +Input frame 3: 0 0 0 1 1 0 1 0 0 1 0 0 + +NORMALIZE + +Input frame 1: 0 1 0 0 1 1 1 0 1 0 0 0 1 0 1 1 + +Input frame 2: 1 0 1 1 1 0 0 0 1 0 0 0 0 0 0 0 + +Input frame 3: 0 0 0 1 1 0 1 0 0 1 0 0 0 0 0 0 + +**b) Parity function application** + +Input frame 1: 0 1 0 0 1 1 1 0 1 0 0 0 1 0 1 1 + +Input frame 2: 1 0 1 1 1 0 0 0 1 0 0 0 0 0 0 0 + +Input frame 3: 0 0 0 1 1 0 1 0 0 1 0 0 0 0 0 0 + +Column-based binary Sum (carry discarded) + +⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ ⊕ + +Resulting output: 1 1 1 0 1 1 0 0 0 1 0 0 1 0 1 1 + +Figure C.1: Illustration of Length normalization and Parity function operation. The diagram is divided into two parts: (a) Length normalization example and (b) Parity function application. Part (a) shows three input frames of different lengths being normalized to a common length of 16 bits. Part (b) shows the same three frames being processed by a column-based binary sum (XOR) operation to produce a 16-bit resulting output. + +T.38\_FC.1 + +Figure C.1 – Illustration of Length normalization and Parity function operation + +### C.2.1 Generating and transmitting FEC messages + +By utilizing a buffer similar to that shown in Figure C.2, it is possible to pass multiple prior primary IFP packets into the parity FEC algorithm for processing. The FEC scheme returns with a frame of encoded data that may then be assembled into a packet after the current primary IFP packet. The transmitting gateway must decide in advance the number of prior IFP messages it shall use to generate the FEC information. The $n$ prior primary IFP packets are sent to the parity encoding scheme which results in a single message of FEC data of length $l$ octets where $l$ is the largest message length value encountered in the list of primary IFP packets plus 2 octets. Finally, the newly generated FEC message is assembled as in Figure C.2 and inserted into the packet after the primary IFP packet. + +![Diagram illustrating the generation and packetization of a single parity FEC frame. An IFP Message Store table shows sequence numbers 41 to 45. Sequence 45 is mapped directly to the PRIMARY MESSAGE field of a packet. Sequences 41, 42, 43, and 44 are shown as inputs to a Parity FEC scheme (a circle with a plus sign), which outputs to the FEC MESSAGE field of the same packet. The packet header contains SEQUENCE NUMBER (45).](ec3647789b5c38fb686f2a0833324e79_img.jpg) + +| | | | +|---------------------------|-----------------|-------------| +| SEQUENCE NUMBER
( 45 ) | PRIMARY MESSAGE | FEC MESSAGE | +|---------------------------|-----------------|-------------| + + + +| Sequence | IFP Message Store | +|----------|-------------------| +| 45 | IFP MESSAGE | +| 44 | IFP MESSAGE | +| 43 | IFP MESSAGE | +| 42 | IFP MESSAGE | +| 41 | IFP MESSAGE | + +Parity FEC scheme + ++ + +T.38\_FC.2 + +Diagram illustrating the generation and packetization of a single parity FEC frame. An IFP Message Store table shows sequence numbers 41 to 45. Sequence 45 is mapped directly to the PRIMARY MESSAGE field of a packet. Sequences 41, 42, 43, and 44 are shown as inputs to a Parity FEC scheme (a circle with a plus sign), which outputs to the FEC MESSAGE field of the same packet. The packet header contains SEQUENCE NUMBER (45). + +**Figure C.2 – Generation and packetization of a single parity FEC frame** + +Multiple FEC messages may be sent in a single packet, each generated from *fec\_npackets* (i.e., the number of) prior primary IFP packets. Unlike the instance where only one FEC message is present, when multiple FEC messages are transmitted in a single packet, the contributing primary IFP packets for each FEC message are not consecutive, but are interleaved. This is illustrated in Figure C.3 which shows an example providing protection against a burst of three consecutive lost packets. + +![Diagram showing the generation of multiple FEC messages from a sequence of IFP messages. A table of sequence numbers and frame data is shown on the left, with arrows indicating the flow of data into three separate parity FEC schemes (represented by circles with a plus sign). The outputs of these schemes are labeled as FEC MESSAGE 1, FEC MESSAGE 2, and FEC MESSAGE n, along with the original PRIMARY MESSAGE and SEQUENCE NUMBER (45).](12c19090355e19922e23044633b9d1ea_img.jpg) + +The diagram illustrates the process of generating multiple Forward Error Correction (FEC) messages to protect against burst errors. It shows a sequence of 10 frames (Sequence 36 to 45) containing IFP messages. These frames are processed by three separate Parity FEC schemes, each represented by a circle with a plus sign (+). The outputs of these schemes are labeled as FEC MESSAGE 1, FEC MESSAGE 2, and FEC MESSAGE n. The original PRIMARY MESSAGE and SEQUENCE NUMBER (45) are also shown as part of the output. + +| Sequence | Frame data | +|----------|-------------| +| 45 | IFP MESSAGE | +| 44 | IFP MESSAGE | +| 43 | IFP MESSAGE | +| 42 | IFP MESSAGE | +| 41 | IFP MESSAGE | +| 40 | IFP MESSAGE | +| 39 | IFP MESSAGE | +| 38 | IFP MESSAGE | +| 37 | IFP MESSAGE | +| 36 | IFP MESSAGE | + +SEQUENCE NUMBER (45) | PRIMARY MESSAGE | FEC MESSAGE 1 | FEC MESSAGE 2 | FEC MESSAGE n + +Parity FEC scheme (+) + +Parity FEC scheme (+) + +Parity FEC scheme (+) + +T.38\_FC.3 + +Diagram showing the generation of multiple FEC messages from a sequence of IFP messages. A table of sequence numbers and frame data is shown on the left, with arrows indicating the flow of data into three separate parity FEC schemes (represented by circles with a plus sign). The outputs of these schemes are labeled as FEC MESSAGE 1, FEC MESSAGE 2, and FEC MESSAGE n, along with the original PRIMARY MESSAGE and SEQUENCE NUMBER (45). + +**Figure C.3 – Generating multiple FEC messages to protect against burst errors** + +### C.2.2 Receiving FEC messages and primary IFP packet reconstruction + +A gateway in receipt of FEC messages in a packet must determine from the UDPTL packet: + +- the number of FEC messages present in the packet; +- the sequence numbers of the primary IFP packets contained in each FEC message; +- the sequence numbers of any packets which have been "lost" over the network. + +In order to determine the sequence numbers of the primary IFP packets encoded in a given FEC message, the receiving gateway must extract the number of primary IFP packets covered by that frame. For a packet containing a single FEC message, the sequence numbers covered by that message are simply those from $[Seq - 1]$ to $[Seq - (n + 1)]$ where $n$ is the value in the `fec_npackets` element and $Seq$ is the value in the `seq-number` element. For a UDPTL packet containing $m$ FEC messages with sequence number $Seq$ and a message control field setting of $n$ , the sequence number ranges for FEC message $I$ (for $1 \leq I \leq m$ ) are trivially extracted from the following equations: + +$$\text{StartSeq} = Seq - I$$ + +$$\text{EndSeq} = Seq - I - (n - 1)m$$ + +Intermediate sequence numbers between these ranges are linearly spaced with gap $m$ . Once the sequence numbers of the primary IFP packets encoded in an FEC message have been determined, the receiving gateway may check to determine whether any of the primary IFP packets listed has failed to arrive. If one, and only one, of these primary IFP packets has failed to arrive, then the FEC message and the remaining (delivered) primary IFP packets may be sent to the parity algorithm to recover the missing sequence. + +The number of FEC messages, $m$ , is the number of octet strings contained in the **fec-data** element (as encoded in the SEQUENCE OF construct). + +# **Annex D** + +## **SIP/SDP call establishment procedures** + +(This annex forms an integral part of this Recommendation.) + +## **D.1 Introduction** + +This annex describes system level requirements and procedures for Internet-aware facsimile implementations and Internet-aware facsimile gateways conforming to ITU-T T.38 to establish calls with other ITU-T T.38 implementations using the procedures defined in [IETF RFC 3261] (SIP) and [IETF RFC 2327] (SDP) and the 'image' media type as defined in [IETF RFC 6466]. SIP [IETF RFC 3261] uses the embedded SDP Offer/Answer protocol (see clause D.2.3.0) for indication and negotiation of media configurations (for example, a specific ITU-T T.38 configuration). + +## **D.2 Communication between gateways** + +### **D.2.1 Overview** + +#### **D.2.1.1 Call set-up** + +Call set-up for Annex D of ITU-T T.38 compliant implementation is based on SIP (session initiation protocol) defined in [IETF RFC 3261]. As in Annex B, implementations may operate in two distinct compatible environments: + +- 1) A facsimile-only over IP environment – In this environment, no voice support is provided. The procedures and requirements of D.2.2.3 shall apply to implementations operating in this environment. +- 2) A facsimile and voice over IP environment – The procedures and requirements of this annex shall apply to implementations operating in this environment. + +#### **D.2.1.2 Media and signalling channels** + +NOTE – The term "channel" is reused from ITU-T H.323 terminology (see Annex B), and is synonymous with "IP transport connection" in this annex. + +ITU-T T.38 facsimile packets are sent on a separate TCP/UDP port from SIP call signalling. A minimal Annex D of ITU-T T.38 implementation requires: + +- for the IP transport connection for SIP: a TCP/UDP port (default is 5060) for call signalling; and +- for the IP transport connection for media (depending on the ITU-T T.38 transport mode): + - a UDP port for "UDPTL/UDP"; + - one or two UDP ports for "RTP/UDP" (depending on RTCP usage); or + - a TCP port for "TPKT/TCP" for ITU-T T.38 facsimile information + +#### **D.2.1.3 Usage of SDP** + +Endpoints conforming to this annex are required to support SDP, including the extensions described below. + +##### D.2.1.3.1 SDP parameter definitions + +The SDP parameters shown in Table D.1 are defined by this Recommendation. + +**Table D.1 – ITU-T T.38 SDP parameter definitions** + +| No. | Parameter name | Definition | +|-----|-----------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | T38FaxVersion | This is the version number of ITU-T T.38. New versions shall be compatible with previous versions. Absence of this parameter indicates version 0. The version is expressed as an integer value. | +| 2 | T38MaxBitRate | Indicates the maximum fax transmission rate supported by the endpoint and shall not be used to negotiate actual transmission speeds. (NOTE 1) | +| 3 | T38FaxFillBitRemoval | Indicates the capability to remove and insert fill bits in Phase C (refer to [ITU-T T.30]), non-ECM data to reduce bandwidth. This is a boolean parameter (inclusion = true, exclusion = false). (NOTE 2) | +| 4 | T38FaxTranscodingMMR | Indicates the ability to convert to/from MMR from/to the line format for increasing the compression of the data and reducing the bandwidth in the packet network. This is a boolean parameter (inclusion = true, exclusion = false). (NOTE 2) | +| 5 | T38FaxTranscodingJBIG | Indicates the ability to convert to/from JBIG to reduce bandwidth. This is a boolean parameter (inclusion = true, exclusion = false). (NOTE 2) | +| 6 | T38FaxRateManagement | Indicates the fax rate management model as defined in [ITU-T T.38]. Values may be "localTCF" or "transferredTCF". | +| 7 | T38FaxMaxBuffer | Indicates the maximum number of octets that can be stored on the remote device before an overflow condition occurs. It is the responsibility of the transmitting application to limit the transfer rate to prevent an overflow. The negotiated data rate should be used to determine the rate at which data is being removed from the buffer. Value is an integer. | +| 8 | T38FaxMaxDatagram | The maximum size of the payload that can be accepted by the remote device. This is an integer value. | +| 9 | T38FaxMaxIFP | This parameter signals the maximum IFP frame size the offering endpoint is capable of accepting. | +| 10 | T38FaxUdpEC | Indicates any desired error correction scheme, either FEC or redundancy or none. Valid options are "t38UDPFEC", "t38UDPRedundancy" and "t38UDPNoEC".
This parameter shall only be present when using UDPTL as the transport for [ITU-T T.38]. | +| 11 | T38FaxUdpECDepth | If the parameter is specified, then the 'minred' value indicates that the offering endpoint wishes to receive at least that many redundancy frames per UDPTL datagram (when the answering endpoint chooses to use t38UDPRedundancy as the error correction mode), or that the offering endpoint wishes to receive at least that many FEC frames per UDPTL datagram (when the answering endpoint chooses to use t38UDPFEC as the error correction mode).
Additionally, if 'maxred' is specified, it indicates that the offering endpoint wishes to receive no more than that many redundancy frames or FEC frames per UDPTL datagram. | + +**Table D.1 – ITU-T T.38 SDP parameter definitions** + +| No. | Parameter name | Definition | +|------------------------------------------------------------------------------------------------------------------------------------------|---------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 12 | T38FaxUdpFECMaxSpan | Indicates that offering endpoint may not be able to properly process FEC frames that span more than the specified number of IFP frames. | +| 13 | T38VendorInfo | Indicates the manufacturer of the endpoint. | +| 14 | T38ModemType | Indicates modem capability supported by the ITU-T T.38 endpoint.
Valid options are:
"t38G3FaxOnly" (0) and
"t38G3AndV34G3" (1).
Note: if not provided, the implied value of this parameter is "t38G3FaxOnly". | +| NOTE 1– See also the informative note in clause H.4 on how the parameter T38MaxBitRate has been interpreted in existing implementations. | | | +| NOTE 2 – If omitted in signalling then default value (= 'false'). | | | + +Only parameter "**T38FaxRateManagement**" is mandatory, all other parameters are optional. See also clause D.2.3.5 with respect to parameter usage in SDP Offer/Answer, and summary in Annex H. + +### **D.2.2 Basic call set-up** + +#### **D.2.2.1 Choosing call set-up mechanism** + +Annex B indicates that ITU-T H.323 FastCall Setup is the basic mechanism for establishing a ITU-T T.38 call. The method described in this annex is intended for use in conjunction with this mechanism in a decomposed gateway model. In addition, this annex may also be used if the emitting gateway is aware that the destination gateway supports the call establishment mechanism of this annex. + +#### **D.2.2.2 SIP call set-up** + +According to [IETF RFC 3261] section 1, SIP supports a five-phase process for establishing and terminating a call: + +| | | +|-------------------|-------------------------------------------------------------------------------------------------------------------------------------------| +| User location | Determination of the end system to be used for communication | +| User capabilities | Determination of the media and media parameters to be used | +| User availability | Determination of the willingness of the called party to engage in communications | +| Call set-up | "Ringing", establishment of call parameters at both called and calling party (via embedded SDP Offer/Answer protocol, see clause D.2.3.0) | +| Call handling | Including transfer and termination of calls | + +SIP can also be used in conjunction with other call set-up and signalling protocols, for example, in an ITU-T H.248 to ITU-T H.323 interworking function. + +SIP can invite users to sessions with and without resource reservation (by usage of embedded SDP Offer/Answer, see clause D.2.3.0). SIP does not reserve resources, but can convey to the invited system the information necessary to do this. + +#### **D.2.2.3 Facsimile-only connection** + +The emitting gateway sends a SIP INVITE request (with the appropriate options set) for an ITU-T T.38 facsimile connection with the receiving SIP server. The receiving server will likely be the receiving gateway; however, it may also proxy or redirect the SIP connection to the actual gateway through SIP or other means. In any case, a response will be sent to the emitting gateway indicating acceptance, redirection or failure of the request. + +If accepted (or a redirected INVITE is accepted), the ITU-T T.38 facsimile call proceeds. + +Once the call is completed, the call may be disconnected with a SIP BYE command. + +See also clause D.2.4.1 for an example of SIP/SDP signalling. + +#### **D.2.2.4 Voice and facsimile connection** + +A SIP INVITE (inclusive SDP Offer) is made to the called party requesting a voice connection per the requirements of [IETF RFC 3261]. A voice connection is then established (which implies the initial state "Audio mode" at the very beginning of the call, see next clause). + +##### **D.2.2.4.1 State model for the voice and facsimile call** + +Figure D.1 illustrates the state model, embedded in example SIP devices. The two operational modes, for the "voice and facsimile call" type, are: + +- *Audio* mode (VoIP), characterized by one or multiple voice codecs; and +- *Fax relay* mode (FoIP), characterized by one or multiple ITU-T T.38 configurations (a "ITU-T T.38 configuration" comprises the ITU-T T.38 transport variant and all ITU-T T.38 parameter settings). + +There might be additional modes like ITU-T V.152 VBDoIP or packet relay modes for non-G3FE modem, but such state transitioning is out of the scope of this Recommendation. + +![Figure D.1: State model for the voice and facsimile call. The diagram shows three state models: (1) SIP terminal, (2) PSTN-SIP gateway without ITU-T V.152 support, and (3) PSTN-SIP gateway with ITU-T V.152 support. Model (1) shows a SIP ITU-T T.38 IAF with an ITU-T T.38 endpoint containing Fax relay mode (ITU-T T.38 FoIP) and Audio mode (VoIP). Model (2) shows a PSTN-SIP ITU-T T.38 gateway with a PSTN endpoint and an ITU-T T.38 endpoint containing Fax relay mode (ITU-T T.38 FoIP) and Audio mode (VoIP). Model (3) shows a PSTN-SIP ITU-T T.38 gateway with a PSTN endpoint and an ITU-T T.38 endpoint containing Fax relay mode (ITU-T T.38 FoIP), Voiceband data mode (ITU-T V.152 VBDolP), and Audio mode (VoIP). Connections are shown for IP bearer, PSTN bearer, and PSTN connections.](89f8aefc01866631793087542316cef2_img.jpg) + +(1) State model for SIP terminal +(= ITU-T T.38 IAF) + +(2) State model for PSTN-SIP ITU-T T.38 gateway +without ITU-T V.152 support + +(3) State model for PSTN-SIP ITU-T T.38 gateway +with ITU-T V.152 support + +T.38(15)\_FD.1 + +Figure D.1: State model for the voice and facsimile call. The diagram shows three state models: (1) SIP terminal, (2) PSTN-SIP gateway without ITU-T V.152 support, and (3) PSTN-SIP gateway with ITU-T V.152 support. Model (1) shows a SIP ITU-T T.38 IAF with an ITU-T T.38 endpoint containing Fax relay mode (ITU-T T.38 FoIP) and Audio mode (VoIP). Model (2) shows a PSTN-SIP ITU-T T.38 gateway with a PSTN endpoint and an ITU-T T.38 endpoint containing Fax relay mode (ITU-T T.38 FoIP) and Audio mode (VoIP). Model (3) shows a PSTN-SIP ITU-T T.38 gateway with a PSTN endpoint and an ITU-T T.38 endpoint containing Fax relay mode (ITU-T T.38 FoIP), Voiceband data mode (ITU-T V.152 VBDolP), and Audio mode (VoIP). Connections are shown for IP bearer, PSTN bearer, and PSTN connections. + +**Figure D.1 – State model for the voice and facsimile call – Example ITU-T T.38 SIP equipment** + +There might be one or multiple state changes during the lifetime of the call. + +NOTE – Example: the emulation of a PSTN "alternate speech-fax" call by the SIP domain, with consecutive call phases of speech-fax-speech, may lead to state transitioning "audio to fax relay to audio". + +The state transitioning may be either: + +- Tightly coupled with SIP/SDP signalling (e.g., an incoming SIP message may enforce a state change), see clause D.2.2.4.2; or +- Autonomous (i.e., a local decision, possibly due to previous agreements), see clause D.2.2.4.3. + +The two state transitioning methods for SIP are consistent with Annex E (which may facilitate interoperability between SIP- and ITU-T H.248-controlled ITU-T T.38 endpoints): + +The "SIP-controlled state transitioning" method relates to the "MGC-strict controlled transitioning" in case of ITU-T H.248 gateways (see clause E.2.2.1: "*ITU-T T.38 media gateway controller (MGC) method*"), and the "Autonomous state transitioning" to the ITU-T H.248 "MG autonomous transitioning" concept (see clause E.2.2.2: "*ITU-T T.38 Autonomous Transitioning method*"). + +##### **D.2.2.4.2 SIP-controlled state transitioning between voice and facsimile** + +Upon detection of facsimile by the receiving gateway, a SIP INVITE request is sent to the emitting gateway (with the same Call-ID as the existing voice connection) for an ITU-T T.38 facsimile connection. + +The receiving gateway should only use the ITU-T V.21 preamble generated by the answering FAX endpoint as the trigger for detection, and it should generate the INVITE request no more than 200 milliseconds after the ITU-T V.21 preamble begins, in order to allow the maximum amount of time for the session to transition into ITU-T T.38 mode before the answering FAX endpoint begins transmitting NSF, CSI or DIS. + +Upon completion of the facsimile call establishment (noted in clause D.2.2.3), the ITU-T T.38 facsimile call proceeds with an ITU-T T.38 V.21 flags indicator packet if it is an ITU-T T.38/G3 connection. + +During the switchover, the receiving gateway should mute the voice channel in both directions until the facsimile connection transition either succeeds or fails. During this period, the receiving gateway should ensure that silence is generated towards both the emitting gateway and the answering FAX endpoint. The receiving gateway should initiate the muting of the channel immediately upon detection of facsimile, as described above. If the receiving gateway is unable to mute the voice channel towards the emitting gateway within 800 milliseconds after detection of facsimile, (or the time when the ITU-T V.21 preamble generated by the answering FAX endpoint concludes), it may still mute the voice channel, but there is a possibility that doing so may cause one or both FAX endpoints to terminate the session if the muting occurs after the answering FAX endpoint has begun transmitting NSF, CSI or DIS. + +The voice channel may be used again once the end of facsimile transmission is detected. Alternatively, some implementations may choose to replace the voice channel with a facsimile channel. + +Once the call is completed, the call may be disconnected with a SIP BYE command. + +See also clause D.2.4.2 for an example of SIP/SDP signalling. + +##### **D.2.2.4.3 Autonomous state transitioning between voice and facsimile** + +Autonomous state transitioning shall only be possible under the following conditions: + +- local and remote side shall both support ITU-T T.38; and +- local and remote side shall agree beforehand on the particular ITU-T T.38 configuration (e.g., ITU-T T.38 transport variant, ITU-T T.38 parameter settings). + +Both conditions may be easily addressed by the usage of *Revised* SDP Offer/Answer in SIP (see clause D.2.3.0): ITU-T T.38 shall be offered as *latent configuration*. A positive response by the *Answerer* side may permit then for autonomous state transitioning. + +NOTE 1 – The term "latent" reflects the considered, possible later transitioning from audio to fax relay. + +NOTE 2 – There might be one or multiple ITU-T T.38 (latent) configuration(s) indicated by the *Offerer* (e.g., when multiple ITU-T T.38 transport capabilities would be supported). + +#### **D.2.2.5 Support of ITU-T T.38 and ITU-T V.34G3 facsimile and fallback to ITU-T T.38/G3 facsimile** + +##### **D.2.2.5.1 Problem statement** + +In networks that provide voice, facsimile and data modem connections, gateways shall have the ITU-T V.8 capability (detecting and transmitting ITU-T V.8 CM/JM/CJ sequences) in order to + +support ITU-T T.38 based FoIP sessions with ITU-T V.34 facsimile terminals. When both emitting and receiving gateways are capable of ITU-T T.38/V.34G3 facsimile, the transition to ITU-T T.38 and ITU-T V.34G3 may occur after the detection of facsimile capability in the ITU-T V.8 CM/JM's call function octet, and proceed according to clause 10. The receiving gateway may also initiate a transition to ITU-T T.38 mode after ANSam is detected, if it knows that the network does not support data modem connections (either in the ITU-T V.150.1 MoIP mode or in the ITU-T V.152 VBDoIP mode). + +##### **D.2.2.5.2 Fallback scenarios** + +In situations where one or both gateways are not ITU-T V.34 capable, fallback to an ITU-T T.38/G3 session shall occur. There are three possible cases: + +- 1) ITU-T V.34 FD (calling) – ITU-T T.38/G3 GW – ITU-T T.38/G3 GW – ITU-T V.34 FD (answering) +- 2) ITU-T V.34 FD (calling) – ITU-T T.38/V.34 G3 GW – ITU-T T.38/G3 GW – ITU-T V.34 FD (answering) +- 3) ITU-T V.34 FD (calling) – ITU-T T.38/G3 GW – ITU-T T.38/V.34G3 GW – ITU-T V.34 FD (answering) + +In all three cases, after going off-hook, the answering facsimile device (FD) sends ANSam to the receiving (ITU-T T.38/G3 or ITU-T T.38/V.34G3) GW. The receiving GW passes ANSam to the emitting GW by either tone-relay or VBD ([IETF RFC 4733] and [ITU-T V.152]). Upon detecting ANSam, the calling ITU-T V.34 FD sends ITU-T V.8 CM sequences indicating that it is capable of both ITU-T V.34 and G3 facsimile. The emitting gateway will detect the ITU-T V.8 CM sequences and is responsible for blocking the audio CM signal. The emitting gateway shall prevent more than one complete CM sequence being transmitted to the receiving gateway (and, therefore, to the answering facsimile device) so that the answering facsimile device will not falsely start the JM transmission. + +The emitting gateway, after the CM sequence is detected and suppressed, will initiate SIP negotiation for voice to ITU-T T.38 switch. During the SIP negotiation (using SDP Offer/Answer), the ITU-T V.34 modem capability will be exchanged via the T38ModemType (see clause D.2.1.3.1) parameter. + +NOTE – It may be necessary to suppress the ITU-T V.8 CM sequence audio. However, the method and procedure to do so are for further study. + +- The call flow for cases #1 and #2 is shown in Figure D.2. In these cases, the emitting gateway itself is an ITU-T T.38/G3 only gateway. After the ITU-T V.8 CM is detected, it can send out JM with G3 only capability to the calling FD immediately, without waiting for the result of SIP/SDP negotiation. +- The call flow for study case #3 is shown in Figure D.3. In this case, the emitting gateway itself is an ITU-T T.38/ITU-T V.34G3+ITU-T T.38/G3 GW. After the ITU-T V.8 CM is detected, it will initiate the SIP ReInvite (using SDP Offer/Answer for re-negotiating an ITU-T T.38 configuration) for an ITU-T T.38 channel. It will send out JM to the calling FD only after the end of SIP/SDP negotiation, since it does not know until then what modulation the receiving gateway supports. The emitting gateway shall send an ITU-T V.8 JM signal to inform the calling FD that the network supports only G3 fax. + +After receiving JM with G3 only capability, the calling FD responds with CJ sequences to end the ITU-T V.8 procedures, and conditions itself for a standard G3 facsimile (see Figure F.5-10 in [ITU-T T.30]). The FoIP session will then fall back to ITU-T T.38/G3 mode after the ANSam timeout at the answering ITU-T V.34 facsimile device (see Figure 6a in [ITU-T T.30]). + +The emitting gateway, after the CM sequence is detected and suppressed, will initiate SIP negotiation for transitioning from voice to ITU-T T.38. During the SIP negotiation, the ITU-T V.34 modem capability will be exchanged via the T38ModemType parameter (see clause D.2.1.3.1). + +- The call flow for cases #1 and #2 is shown in Figure D.2. In these cases, the emitting gateway itself is an ITU-T T.38/G3 only gateway (providing the SDP Offerer role in SDP Offer/Answer procedures). After the ITU-T V.8 CM is detected, it can send out JM with G3 only capability to the calling FD immediately, without waiting for the result of SIP/SDP negotiation (which must be a positively acknowledged SDP answer). +- The call flow for study case #3 is shown in Figure D.3. In this case, the emitting gateway itself is an ITU-T T.38/ITU-T V.34G3+ITU-T T.38/G3 GW. After the ITU-T V.8 CM is detected, it will initiate the SIP ReInvite (using SDP Offer/Answer for re-negotiating an ITU-T T.38 configuration) for an ITU-T T.38 channel. It will send out JM to the calling FD only after the end of SIP/SDP negotiation, since it does not know until then what modulation the receiving gateway supports. The emitting gateway shall send an ITU-T V.8 JM signal to inform the calling FD that the network supports only G3 fax. + +After receiving JM with G3 only capability, the calling FD responds with CJ sequences to end the ITU-T V.8 procedures, and conditions itself for a standard G3 facsimile (see Figure F.5-10 in [ITU-T T.30]). The FoIP session will then fall back to ITU-T T.38/G3 mode after the ANSam timeout at the answering ITU-T V.34 facsimile device (see Figure 6a in [ITU-T T.30]). + +###### Voice to fax transition with SIP: Fallback to G3 from ITU-T V.34 fax + +![Sequence diagram showing the call setup and transition from voice mode to ITU-T T.38/G3 mode between V34FD1, GW1, GW2, and V34FD2.](9cd85f266cdb1fb3ad544eb3dd3bd5e4_img.jpg) + +``` + +sequenceDiagram + participant V34FD1 + participant GW1 as GW1: ITU-T T.38/G3 + participant GW2 as GW2: ITU-T T.38/ITU-T V.34 +or ITU-T T.38/G3 + participant V34FD2 + + V34FD1->>GW1: OFF HOOK + V34FD1->>GW1: DIALING + + Note over V34FD1, GW1, GW2, V34FD2: Call setup via PSTN and SIP server + + Note over V34FD1, GW1, GW2, V34FD2: Voice mode + + V34FD1->>GW1: CNG + GW1->>GW2: Tone relay or tone event or ITU-T G.711: CNG + GW2->>V34FD2: CNG + V34FD2->>GW2: ANSam + GW2->>GW1: Tone relay or tone event or ITU-T G.711: ANSam + GW1->>V34FD1: ANSam + V34FD1->>GW1: ITU-T V.8 CM (ITU-T V.34 + G3 fax) + V34FD1->>GW1: ITU-T V.8 JM (G3 fax only) + GW1->>GW2: Suppress ITU-T V.8 CM + GW1->>GW2: SIP: REINVITE + GW2->>GW1: SIP: 200 OK + GW2->>GW1: SIP: ACK + V34FD1->>GW1: ITU-T V.8 CJ + + Note over V34FD1, GW1, GW2, V34FD2: ITU-T T.38/G3 mode + + V34FD1->>GW1: CED + GW1->>GW2: T30 IND: CED + GW2->>V34FD2: ANSam + V34FD2->>GW2: ANSam Timeout + V34FD2->>GW2: ITU-T V.21 Flags + V34FD2->>GW2: ITU-T V.21 CSI/DIS + V34FD1->>GW1: ITU-T V.21 Flags + V34FD1->>GW1: ITU-T V.21 CSI/DIS + V34FD1->>GW1: ITU-T V.21 Flags + V34FD1->>GW1: ITU-T V.21 TSI/DCS + GW1->>GW2: T30 IND: Flags + GW1->>GW2: ITU-T V.21: HDLC:CSI/DIS + GW1->>GW2: T30 IND: Flags + GW1->>GW2: ITU-T V.21: HDLC: TSI/DCS + GW2->>V34FD2: ITU-T V.21 Flags + GW2->>V34FD2: ITU-T V.21 TSI/DCS + +``` + +The diagram illustrates the call setup and transition from voice mode to ITU-T T.38/G3 mode. It involves four entities: V34FD1, GW1 (ITU-T T.38/G3), GW2 (ITU-T T.38/ITU-T V.34 or ITU-T T.38/G3), and V34FD2. The process begins with V34FD1 sending OFF HOOK and DIALING signals to GW1. Call setup is then performed via PSTN and SIP server. The initial phase is Voice mode, where CNG and ANSam signals are exchanged between V34FD1, GW1, and GW2. V34FD1 sends ITU-T V.8 CM and ITU-T V.8 JM (G3 fax only) to GW1, which then suppresses ITU-T V.8 CM and sends SIP: REINVITE to GW2. GW2 responds with SIP: 200 OK and SIP: ACK. V34FD1 then sends ITU-T V.8 CJ to GW1. The transition to ITU-T T.38/G3 mode follows, where CED and T30 IND: CED signals are sent from V34FD1 to GW1 and then to GW2. GW2 sends ANSam and ANSam Timeout signals to V34FD2. V34FD2 then sends ITU-T V.21 Flags and ITU-T V.21 CSI/DIS signals to GW2. V34FD1 sends ITU-T V.21 Flags and ITU-T V.21 TSI/DCS signals to GW1, which then sends T30 IND: Flags and ITU-T V.21: HDLC:CSI/DIS signals to GW2. Finally, GW2 sends ITU-T V.21 Flags and ITU-T V.21 TSI/DCS signals to V34FD2. + +Sequence diagram showing the call setup and transition from voice mode to ITU-T T.38/G3 mode between V34FD1, GW1, GW2, and V34FD2. + +T.38(15)\_FD.2 + +**Figure D.2 – Call set-up with SIP (fallback from ITU-T V.34 fax to G3), +Emitting GW supports G3 only** + +![Sequence diagram showing the call setup and transition from ITU-T V.34 fax to G3 mode via SIP. The diagram involves four entities: V34FD1, GW1 (ITU-T T.38/ITU-T V.34 + ITU-T T.38/G3), GW2 (ITU-T T.38/G3), and V34FD2. The process starts with V34FD1 sending OFF HOOK and DIALING to GW1. A call setup phase occurs via PSTN and SIP server. In Voice mode, V34FD1 sends CNG to GW1, which relays it to GW2 and then to V34FD2. Similarly, V34FD2 sends ANSam to GW2, which relays it to GW1 and then to V34FD1. V34FD1 sends ITU-T V.8 CM to GW1, which suppresses it and sends SIP: REINVITE to GW2. V34FD1 sends ITU-T V.8 JM to GW1, which relays it to GW2. V34FD1 sends ITU-T V.8 CJ to GW1, which relays it to GW2. GW2 sends SIP: 200 OK to GW1, which relays it to V34FD1. GW2 sends SIP: ACK to GW1. In ITU-T T.38/G3 mode, V34FD1 sends CED to GW1, which relays it to GW2 and then to V34FD2. V34FD2 sends ANSam to GW2, which relays it to GW1 and then to V34FD1. V34FD1 sends ITU-T V.21 Flags to GW1, which relays it to GW2 and then to V34FD2. V34FD1 sends ITU-T V.21 CSI/DIS to GW1, which relays it to GW2 and then to V34FD2. V34FD1 sends ITU-T V.21 Flags to GW1, which relays it to GW2 and then to V34FD2. V34FD1 sends ITU-T V.21 TSI/DCS to GW1, which relays it to GW2 and then to V34FD2. V34FD2 sends ITU-T V.21 Flags to GW2, which relays it to GW1 and then to V34FD1. V34FD2 sends ITU-T V.21 TSI/DCS to GW2, which relays it to GW1 and then to V34FD1. A star symbol indicates a timeout or error condition.](0ccaa59b5bc46884777e728ee3dadaa7_img.jpg) + +Sequence diagram illustrating the call setup and transition from ITU-T V.34 fax to G3 mode via SIP, where the receiving gateway (GW2) supports G3 only. + +**Entities:** V34FD1, GW1: ITU-T T.38/ITU-T V.34 + ITU-T T.38/G3, GW2: ITU-T T.38/G3, V34FD2. + +**Call Setup:** V34FD1 sends OFF HOOK and DIALING to GW1. Call setup via PSTN and SIP server. + +**Voice mode:** + +- V34FD1 sends CNG to GW1. GW1 relays Tone relay or tone event or ITU-T G.711: CNG to GW2. GW2 relays CNG to V34FD2. +- V34FD2 sends ANSam to GW2. GW2 relays Tone relay or tone event or ITU-T G.711: ANSam to GW1. GW1 relays ANSam to V34FD1. +- V34FD1 sends ITU-T V.8 CM (ITU-T V.34 + G3 fax) to GW1. GW1 suppresses ITU-T V.8 CM and sends SIP: REINVITE (T38Modulation type=0, ITU-T V.34+G3) to GW2. +- V34FD1 sends ITU-T V.8 JM (G3 fax only) to GW1. GW1 relays SIP: 200 OK (T38Modulation type=2, G3 only) to GW2. GW2 relays SIP: 200 OK to V34FD1. +- V34FD1 sends ITU-T V.8 CJ to GW1. GW1 relays SIP: ACK to GW2. GW2 relays SIP: ACK to V34FD1. + +**ITU-T T.38/G3 mode:** + +- V34FD1 sends CED to GW1. GW1 relays T30 IND: CED to GW2. GW2 relays ANSam to V34FD2. +- V34FD2 sends ANSam to GW2. GW2 relays ANSam Timeout to V34FD1. +- V34FD1 sends ITU-T V.21 Flags to GW1. GW1 relays T30: IND : Flags to GW2. GW2 relays ITU-T V.21 Flags to V34FD2. +- V34FD1 sends ITU-T V.21 CSI/DIS to GW1. GW1 relays ITU-T V.21: HDLC:CSI/DIS to GW2. GW2 relays ITU-T V.21 CSI/DIS to V34FD2. +- V34FD1 sends ITU-T V.21 Flags to GW1. GW1 relays T30: IND : Flags to GW2. GW2 relays ITU-T V.21 Flags to V34FD2. +- V34FD1 sends ITU-T V.21 TSI/DCS to GW1. GW1 relays ITU-T V.21: HDLC:TSI/DCS to GW2. GW2 relays ITU-T V.21 TSI/DCS to V34FD2. + +T.38(15)\_FD.3 + +Sequence diagram showing the call setup and transition from ITU-T V.34 fax to G3 mode via SIP. The diagram involves four entities: V34FD1, GW1 (ITU-T T.38/ITU-T V.34 + ITU-T T.38/G3), GW2 (ITU-T T.38/G3), and V34FD2. The process starts with V34FD1 sending OFF HOOK and DIALING to GW1. A call setup phase occurs via PSTN and SIP server. In Voice mode, V34FD1 sends CNG to GW1, which relays it to GW2 and then to V34FD2. Similarly, V34FD2 sends ANSam to GW2, which relays it to GW1 and then to V34FD1. V34FD1 sends ITU-T V.8 CM to GW1, which suppresses it and sends SIP: REINVITE to GW2. V34FD1 sends ITU-T V.8 JM to GW1, which relays it to GW2. V34FD1 sends ITU-T V.8 CJ to GW1, which relays it to GW2. GW2 sends SIP: 200 OK to GW1, which relays it to V34FD1. GW2 sends SIP: ACK to GW1. In ITU-T T.38/G3 mode, V34FD1 sends CED to GW1, which relays it to GW2 and then to V34FD2. V34FD2 sends ANSam to GW2, which relays it to GW1 and then to V34FD1. V34FD1 sends ITU-T V.21 Flags to GW1, which relays it to GW2 and then to V34FD2. V34FD1 sends ITU-T V.21 CSI/DIS to GW1, which relays it to GW2 and then to V34FD2. V34FD1 sends ITU-T V.21 Flags to GW1, which relays it to GW2 and then to V34FD2. V34FD1 sends ITU-T V.21 TSI/DCS to GW1, which relays it to GW2 and then to V34FD2. V34FD2 sends ITU-T V.21 Flags to GW2, which relays it to GW1 and then to V34FD1. V34FD2 sends ITU-T V.21 TSI/DCS to GW2, which relays it to GW1 and then to V34FD1. A star symbol indicates a timeout or error condition. + +**Figure D.3 – Call set-up with SIP (fallback from ITU-T V.34 fax to G3), +Receiving GW supports G3 only** + +### D.2.3 Capabilities indication and negotiation + +There are several capabilities that need to be negotiated to determine which options the gateways support and use. These are described in Table B.1. + +IETF RFC 2327 session description protocol (SDP) provides mechanisms for describing sessions for SIP. There are several ITU-T T.38 specific parameters that may be negotiated when establishing an ITU-T T.38 media stream. For historic reasons, this is done differently for the UDPTL/TCP and TPKT/TCP transport versus the RTP/UDP transport. + +#### D.2.3.0 SDP Offer/Answer protocol for indication and negotiation of ITU-T T.38 configurations + +The SIP message shall provide an SDP Offer for the indication and negotiations of ITU-T T.38 configurations. The "revised SDP Offer/Answer" protocol (see clause 5.1.1) should be supported + +and is recommended due to its advantages, particularly concerning ITU-T T.38 (as a potential parallel media configuration to audio and as a possible later configuration after a speech call phase, due to multiple ITU-T T.38 transport variants, etc.). The "*legacy* SDP Offer/Answer" protocol (see clause 5.1.1) may be used as a minimum solution, permitting limited ITU-T T.38 services (e.g., increased call set-up delays due to possible multiple SDP O/A cycles (NOTE 1), no support of autonomous state transitioning). + +NOTE 1 – E.g., it is not possible to define multiple *ITU-T T.38 parameter settings* for the same *ITU-T T.38 transport variant* (i.e., multiple ITU-T T.38 configurations) within a single "m=" line section for ITU-T T.38. + +#### D.2.3.1 Negotiation for UDPTL/UDP and TPKT/TCP transport + +New attributes (section 6 [IETF RFC 2327] of SDP) are required to support this Recommendation when using the UDPTL and TCP transports. Note that the attributes defined below are specific to the use of ITU-T T.38 with either the UDPTL or TCP transport and do not apply to the use of ITU-T T.38 with RTP (see D.2.3.2). Specifically, the following options are registered with IANA as valid att-field and att-value values per the procedure noted in Appendix B of SDP ([IETF RFC 2327]). Note that options without values are boolean – their presence indicates that they are valid for the session. These capabilities are negotiated using the following ABNF elements defined for use with this Recommendation: + +``` +Version + att-field="T38FaxVersion" + att-value = 1*(DIGIT) + ;see clause 5, Table on ITU-T T.38 ASN.1 version numbers: + ;Version 0, the default, refers to ITU-T T.38 (1998) + ;Version 1, refers to ITU-T T.38 (2000) + ;Version 2, refers to ITU-T T.38 (2002) + ;Version 3, refers to ITU-T T.38 (2005, 2007) + ;Version 4, refers to ITU-T T.38 (2010) +Maximum Bit Rate + att-field="T38MaxBitRate" + att-value = 1*(DIGIT) +Fill Bit Removal + att-field="T38FaxFillBitRemoval" +MMR Transcoding + att-field="T38FaxTranscodingMMR" +JBIG Transcoding + att-field="T38FaxTranscodingJBIG" +Data Rate Management Method + att-field="T38FaxRateManagement" + att-value = "localTCF" | "transferredTCF" +UDPTL Options +Maximum Buffer Size + att-field="T38FaxMaxBuffer" + att-value = 1*(DIGIT) + ;optional +Maximum Datagram Size + att-field="T38FaxMaxDatagram" + att-value = 1*(DIGIT) + ;optional +Maximum Primary IFP Size + att-field = "T38FaxMaxIFP" + att-value = 1*(DIGIT) +Error Correction + att-field="T38FaxUdpEC" + att-value = "t38UDPNNoEC" | "t38UDPFEC" | "t38UDPRedundancy" +Error Correction Depth +``` + +``` + + att-field = "T38FaxUdpECDepth" + att-value = minred [ SP maxred ] + minred = 1*(DIGIT) + maxred = 1*(DIGIT) +Error Correction Span + att-field = "T38FaxUdpFECMaxSpan" + att-value = 1*(DIGIT) +T38VendorInfo + att-field="T38VendorInfo" + att-value = t35country-code SP t35extention SP manufacturer-code + t35country-code = 1*(DIGIT) + t35extension = 1*(DIGIT) + manufacturer-code = 1*(DIGIT) + ;optional + ;0 to 255 for t35country-code and t35extension + ;t35country-code is defined in ITU-T T.35 Annex A. + ;t35extension is defined in ITU-T T.35 Annex B + ;The value of "manufacturer-code" is assigned nationally + ;and identifies an equipment manufacturer. + ;Example a=T38VendorInfo:0 0 37 + +``` + +#### D.2.3.2 Negotiation for RTP/UDP + +The MIME type registration for "audio/T38" defines several optional parameters that may be used with ITU-T T.38 over RTP. Those parameters are supplied in a semicolon separated list of "parameter" or "parameter=value" pairs using the "a=fmtp" parameter defined in SDP; the "parameter" form is used for boolean values, where presence equals "true" and absence "false". The ABNF parameter definitions are repeated here: + +``` + +Version + Name=T38FaxVersion + Value= 1*(DIGIT) + ;see clause 5, Table on ITU-T T.38 ASN.1 version numbers: + ;Version 0, the default, refers to ITU-T T.38 (1998) + ;Version 1, refers to ITU-T T.38 (2000) + ;Version 2, refers to ITU-T T.38 (2002) + ;Version 3, refers to ITU-T T.38 (2005, 2007) + ;Version 4, refers to ITU-T T.38 (2010) +Maximum Bit Rate + Name=T38MaxBitRate + Value= 1*(DIGIT) +Fill Bit Removal + Name=T38FaxFillBitRemoval + ;Boolean +MMR Transcoding + Name=T38FaxTranscodingMMR + ;Boolean +JBIG Transcoding + Name=T38FaxTranscodingJBIG + ;Boolean +Data Rate Management Method + Name=T38FaxRateManagement + Value = "localTCF" | "transferredTCF" +Maximum Buffer Size + Name=T38FaxMaxBuffer + Value = 1*(DIGIT) + ;optional +Maximum Datagram Size + Name=T38FaxMaxDatagram + Value = 1*(DIGIT) + ;optional + +``` + +``` + +Maximum Primary IFP Size + Name = T38FaxMaxIFP + Value = 1*(DIGIT) +T38VendorInfo + Name =T38VendorInfo + Value = t35country-code SP t35extention SP manufacturer-code + t35country-code = 1*(DIGIT) + t35extension = 1*(DIGIT) + manufacturer-code = 1*(DIGIT) + ;optional + ;0 to 255 for t35country-code and t35extension + ;t35country-code is defined in ITU-T T.35 Annex A. + ;t35extension is defined in ITU-T T.35 Annex B + ;The value of "manufacturer-code" is assigned nationally + ;and identifies an equipment manufacturer. + ;Example a=fmtp:100 T38VendorInfo=0 0 37, where 100 is the dynamic payload +type value. + +``` + +NOTE – There is no Error Correction defined for this Recommendation over RTP redundancy, and FEC can be declared for RTP payloads according to the SDP usage defined in [IETF RFC 2198] and [IETF RFC 5109]. + +#### **D.2.3.3 Declaration of ITU-T T.38 in SDP** + +The image/t38 MIME content type in SDP indicates this Recommendation. + +This choice is consistent with image/tiff used in [ITU-T T.37] and image/g3fax used for [ITU-T X.420]. + +#### **D.2.3.4 Use of either TCP or UDP** + +Two logical channels (sender to receiver channel and receiver to sender channel) shall be opened for the transfer of ITU-T T.38 packets. ITU-T T.38 packets can be transferred using either TCP or UDP. In general, the usage of TCP is more effective when the bandwidth for facsimile communication is limited, or for IAF to IAF transfers since TCP provides flow control. On the other hand, the usage of UDP may be more effective when the bandwidth for facsimile communication is sufficient. + +Note that during the SIP call set-up, the calling party suggests the transport (TCP or UDP) by listing its preferred first in the SDP of a SIP INVITE. The receiver should open the TCP/UDP port based on the preference of the sender, but the receiver decides. + +In support of ITU-T T.38 choice of UDP or TCP transport, SDP extensions: + +- indicate UDPTL (facsimile user datagram protocol transport layer) as a valid transport value (third field); +- indicate TCP (transmission control protocol) as a valid transport value (third field); +- indicate RTP/AVP (real-time protocol/audio-video profile) as a valid transport value (third field); +- indicate RTP/SAVP (real-time protocol/secure audio-video profile) as a valid transport value (third field); +- indicate other RTP profiles (e.g., AVPF and SAVPF) as a valid transport value (third field); +- include t38 as a valid format type value (fourth field). This value is used when the transport value is UDPTL or TCP; + +- include an RTP payload type as a valid format type value (fourth field). This value is used when the transport value is RTP/AVP or RTP/SAVP. This payload type is mapped via an 'rtptime' attribute to the MIME type "audio/t38". + +When the transport layer is RTP, standard RTP mechanisms for packet redundancy ([IETF RFC 2198]) and FEC protection ([IETF RFC 5109]) may be used. The declaration of these mechanisms in SDP is described in [IETF RFC 2198] and [IETF RFC 5109]. + +NOTE – As t38 is not an RTP-defined value, it has to be a MIME sub-type of the media type. As a result, this is awaiting the publication of an IETF RFC to define the registration of audio/t38 with IANA as a valid MIME content-type per the procedure noted in Appendix B of SDP ([IETF RFC 2327]). + +#### D.2.3.5 SDP parameter usage in SIP/SDP Offer/Answer negotiations + +This clause (see also summary in Annex H) describes the use of ITU-T T.38 SDP parameters when utilized with the SIP/SDP offer/answer model. + +**T38MaxBitRate** is declarative and the answer is independent of the offer. The parameter simply indicates the maximum transmission bit rate supported by the endpoint. + +**T38FaxFillBitRemoval** is negotiated. If the answering entity does not support this capability or if the capability was not in the offer, this parameter shall not be present in the answer. + +NOTE 1 – Then default behaviour according to the semantic 'false' applies. + +**T38FaxTranscodingMMR** is negotiated. If the answering entity does not support this capability or if the capability was not in the offer, this parameter shall not be present in the answer. + +NOTE 2 – Then default behaviour according to the semantic 'false' applies. + +**T38FaxTranscodingJBIG** is negotiated. If the answering entity does not support this capability or if the capability was not in the offer, this parameter shall not be present in the answer. + +NOTE 3 – Then default behaviour according to the semantic 'false' applies. + +**T38FaxRateManagement** is declarative and the answer must contain the same value. + +**T38FaxVersion** is negotiated. The entity answering the offer shall return the same or a lower version number. + +**T38FaxMaxBuffer** is declarative and the answer is independent of the offer. This parameter simply signals the buffer space available on the offering endpoint and the answering endpoint. The answering endpoint may have more or less buffer space than the offering endpoint. Each endpoint should be considerate of the available buffer space on the opposite endpoint. + +**T38FaxMaxDatagram** is declarative and the answer is independent of the offer. This parameter signals the largest acceptable datagram for the offering endpoint and the answering endpoint (i.e., the maximum size of the RTP payload). The answering endpoint may accept a larger or smaller datagram than the offering endpoint. Each endpoint should be considerate of the maximum datagram size of the opposite endpoint. If an offer includes the **T38FaxMaxIFP** parameter, then this parameter shall be included as well. + +**T38FaxMaxIFP** is declarative and the answer is independent of the offer. This parameter signals the maximum IFP frame size that the offering endpoint is capable of accepting, exclusive of any framing, error correction or other overhead. The answerer may specify a larger or smaller maximum IFP size than the offerer. Each endpoint should consider the maximum IFP size specified by the opposite endpoint. If this parameter is included in an offer, then the **T38FaxMaxDatagram** parameter shall be included in the offer as well. + +**T38FaxUdpEC** is negotiated only when using UDPTL as the transport (NOTE 1). This parameter can have one of three values (see also Table D.2): *t38UDPNoEC*, *t38UDPRedundancy*, or + +*t38UDPFEC*. If the answering endpoint supports the offered error correction mode, then it shall return the same value in the answer, otherwise a different value shall be returned. Based on this capability exchange, a choice may be made on which scheme is used for error correction as follows: + +**Table D.2 – Value range for SDP parameter "T38FaxUdpEC"** + +| T38FaxUdpEC | Description | +|--------------------|--------------------------------------------------------------------------------------------------------------------------| +| t38UDPNNoEC | No secondary IPF packets will be sent. The number of secondary messages is set to zero in UDPTL. | +| t38UDPRedundancy | Only redundant error correction messages may be sent. | +| t38UDPFEC | The endpoints can use either redundancy or FEC error correction scheme.
(NOTE – this is consistent with clause 9.1.3) | + +NOTE 4 – The declaration of multiple ITU-T T.38 error correction schemes is possible in a single SDP offer/answer cycle in case of *revised SDP offer/answer* (see clause 5.1.1), but implies multiple SDP offer/answer cycles in case of *legacy SDP offer/answer* (because there might be no multiple appearances of the same ITU-T T.38 SDP attribute), + +**T38FaxUdpECDepth** is declarative and the answer is independent of the offer, and is relevant only when using UDPTL as the transport. If the parameter is specified, then the 'minred' value indicates that the offering endpoint wishes to receive **at least** that many redundancy frames per UDPTL datagram (when the answering endpoint chooses to use t38UDPRedundancy as the error correction mode), or that the offering endpoint wishes to receive **at least** that many FEC frames per UDPTL datagram when the answering endpoint chooses to use t38UDPFEC as the error correction mode). Additionally, if 'maxred' is specified, it indicates that the offering endpoint wishes to receive **no more** than that many redundancy frames or FEC frames per UDPTL datagram. The answerer may specify a larger or smaller minimum or maximum error correction depth than the offerer. Each endpoint should be considerate of the minimum and maximum error correction depth specified by the opposite endpoint. + +**T38FaxUdpFECMaxSpan** is declarative and the answer is independent of the offer, and is relevant only when using UDPTL as the transport. If the parameter is specified, it indicates that offering endpoint may not be able to properly process FEC frames that span more than the specified number of IFP frames, and if the answering endpoint generates FEC frames spanning more than the specified number of IFP frames, the offering endpoint may have no option but to ignore them (resulting in no effective error correction for the session). The answerer may specify a larger or smaller maximum span than the offerer. Each endpoint should be considerate of the maximum span specified by the opposite endpoint. + +**T38VendorInfo** is declarative and the answer is independent of the offer. The parameter merely indicates the manufacturer of the endpoint. + +**T38ModemType** is negotiated. If the parameter is not present in the SIP/SDP negotiation, The Group 3 facsimile only (t38G3FaxOnly) is assumed. + +### **D.2.4 Examples of call set-up** + +#### **D.2.4.1 SIP Invite for facsimile-only calls** + +The default case requires support for both TCP and UDP. A UDPTL or RTP encapsulation method may be used in conjunction with UDP transport. In this case, two 'm=' lines are listed with the preferred one first in the INVITE. The rejected media connection will be indicated with a port number set to zero in the response (in case of *Legacy SDP Offer/Answer*). + +##### D.2.4.1.1 Example 1 – Agreement on ITU-T T.38-over-UDPTL/UDP, multiple transport variants offered + +For a two-party facsimile-only call between ITU-T T.38 gateways, when UDPTL encapsulation is used in conjunction with the UDP transport protocol: + +**Table D.3 – Example SIP/SDP encoding – "Example 1" in *Legacy* SDP Offer/Answer syntax** + +| SIP/SDP encoding | Comments | +|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1) OFFER (here in SIP INVITE ):
C->S: INVITE sip:+1-212-555-1234@bell-tel.com SIP/2.0
Via: SIP/2.0/UDP kton.bell-tel.com
From: A. Bell
To: T. Watson
Call-ID: 3298420296@kton.bell-tel.com
Cseq: 1 INVITE
Subject: Mr. Watson, here is a fax
Content-Type: application/sdp
Content-Length: ...
v=0
o=faxgw1 2890844526 2890842807 IN IP4 128.59.19.68
e=+1-212-555-1234@bell-tel.com
t=2873397496 0
c=IN IP4 128.59.19.68
m=image 49170 udptl t38
a=T38FaxRateManagement:transferredTCF
a=T38FaxUdpEC:t38UDPFEC
m=image 49172 tcp t38
a=T38FaxRateManagement:localTCF | The Offerer is supporting two ITU-T T.38 configurations:
  • ITU-T T.38-over-UDPTL/UDP; and
  • ITU-T T.38-over-TPKT/TCP.
NOTE – The Offerer is providing just some ITU-T T.38 parameters, but not all. It is recommended to signal explicitly all ITU-T T.38 parameters in order to ensure unambiguous ITU-T T.38 configuration settings. | +| 2) ANSWER (here in SIP 200 OK ):
S->C: SIP/2.0 200 OK
Via: SIP/2.0/UDP kton.bell-tel.com
From: A. Bell
To: T. Watson
Call-ID: 3298420296@kton.bell-tel.com
Cseq: 1 INVITE
Contact: sip:watson@boston.bell-tel.com
Content-Type: application/sdp
Content-Length: ...
v=0
o=faxwatson 4858949 4858949 IN IP4 192.1.2.3
c=IN IP4 boston.bell-tel.com
m=image 5002 udptl t38
a=T38FaxRateManagement:transferredTCF
a=T38FaxUdpEC:t38UDPFEC
m=image 0 tcp t38 | The Answerer is rejecting the TPKT/TCP option (via the SDP null port semantic) and accepting UDPTL/UDP transport. | + +Table D.4 provides the encoding of example 1 in *Revised* SDP Offer/Answer syntax (just SDP syntax is illustrated, without the SIP header lines). + +**Table D.4 – Example SIP/SDP encoding – "Example 1" in *Revised* SDP Offer/Answer syntax** + +| SDP encoding (shortened SDP description) | Comments | +|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 
 1) OFFER (embedded in SIP INVITE): ... ; ACTUAL CONFIGURATION (due to backward compatibility) m=image 49170 udptl t38 a=T38FaxRateManagement:transferredTCF a=T38FaxUdpEC:t38UDPFEC m=image 49172 tcp t38 a=T38FaxRateManagement:localTCF ; ; POTENTIAL CONFIGURATIONS a=tcap:1 udptl ; ITU-T T.38 FoUDPTL/UDP transport variant a=tcap:2 tcp ; ITU-T T.38 FoTPKT/TCP transport variant a=mcap:1 t38 ; ITU-T T.38 FoIP codec (subtype = 't38') ; Transport-independent ITU-T T.38 parameters a=acap:11 T38FaxVersion:4 ; Transport-dependent ITU-T T.38 parameters for UDPTL/UDP a=acap:12 T38FaxUdpEC:t38UDPFEC a=acap:13 (... additional ITU-T T.38 UDPTL attributes should be included) ; Transport-dependent ITU-T T.38 parameters for TPKT/TCP a=acap:21 T38FaxRateManagement:localTCF a=acap:22 (... additional ITU-T T.38 TPKT attributes should be included) ; Preferences a=pcfg:1 t=1 m=1 a=-ms:11,12,13,14,... a=pcfg:2 t=2 m=1 a=-ms:11,21,...
|

Offered (2) potential configurations:
Preference 1: ITU-T T.38 FoUDPTL/UDP
Preference 2: ITU-T T.38 FoTPKT/TCP

NOTE – The media type in a potential configuration ("a=pcfg:") is identical to the actual configuration (i.e., here 'image').

| +| 
 2) ANSWER (embedded in SIP 200 OK): ... a=acfg:1
|

The Answerer agrees to UDPTL/UDP transport and the correspondent parameter settings.

| + +The following main advantages may be noted concerning *Revised* versus *Legacy* SDP Offer/Answer: + +- "null port" semantic is not required for rejecting media configurations; +- there is an explicit indicated, preferred order with regards to the offered media configurations; and +- the answerer in *legacy* SDP Offer/Answer could principally select both ITU-T T.38 configurations (which may require subsequent Offer/Answer cycles). + +##### **D.2.4.1.2 Example 2 – Agreement on ITU-T T.38-over-RTP/UDP with RTP forward error correction** + +For a two-party facsimile-only call between ITU-T T.38 gateways, when RTP encapsulation is used in conjunction with the UDP transport protocol: + +**Table D.5 – Example SIP/SDP encoding – "Example 2" in *Legacy* SDP Offer/Answer syntax** + +| SIP/SDP encoding | Comments | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------| +|

1) OFFER (here in SIP INVITE):

 C->S: INVITE sip:+1-212-555-1234@bell-tel.com SIP/2.0 Via: SIP/2.0/UDP kton.bell-tel.com From: A. Bell <sip:+1-519-555-1234@bell-tel.com> To: T. Watson <sip:+1-212-555-1234@bell-tel.com> Call-ID: 3298420296@kton.bell-tel.com Cseq: 1 INVITE Subject: Mr. Watson, here is a fax Content-Type: application/sdp Content-Length: ... v=0 o=faxgw1 2890844526 2890842807 IN IP4 128.59.19.68 e=+1-212-555-1234@bell-tel.com t=2873397496 0 c=IN IP4 128.59.19.68 m=audio 49170 RTP/AVP 100 101 a=rtpmap:100 t38/8000 a=fmtp:100 T38FaxRateManagement=transferredTCF a=rtpmap:101 parityfec/8000 a=fmtp:101 49173 IN IP4 128.59.19.68 m=image 49172 tcp t38 a=T38FaxRateManagement:localTCF
| | +|

2) ANSWER (here in SIP 200 OK):

 S->C: SIP/2.0 200 OK Via: SIP/2.0/UDP kton.bell-tel.com From: A. Bell <sip:+1-519-555-1234@bell-tel.com> To: T. Watson <sip:+1-212-555-1234@bell-tel.com> Call-ID: 3298420296@kton.bell-tel.com Cseq: 1 INVITE Contact: sip:watson@boston.bell-tel.com Content-Type: application/sdp Content-Length: ... v=0 o=faxwatson 4858949 4858949 IN IP4 192.1.2.3 c=IN IP4 boston.bell-tel.com m=audio 5002 RTP/AVP 100 101 a=rtpmap:100 t38/8000 a=fmtp:100 T38FaxRateManagement=transferredTCF a=rtpmap:101 parityfec/8000 a=fmtp:101 5004 IN IP4 192.1.2.3 m=image 0 tcp t38
| | + +This example shows forward error correction (FEC) as defined for RTP media streams in [IETF RFC 5109]. In this case, a separate UDP port is allocated to the FEC stream. For the case when [IETF RFC 2198] encapsulation is used in conjunction with FEC, the SDP descriptors in this example will need to be modified per [IETF RFC 5109]. + +For secure RTP, the third field (transport protocol) on the 'm=' lines would have been RTP/SAVP rather than RTP/AVP. + +Table D.5 provides the encoding of example 2 in *Revised* SDP Offer/Answer syntax (just SDP syntax is illustrated, without the SIP header lines). + +**Table D.5 – Example SIP/SDP encoding – "Example 2" in Revised SDP Offer/Answer syntax** + +| SDP encoding (shortened SDP description) | Comments | +|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 
 1) OFFER (embedded in SIP INVITE): ... ; ACTUAL CONFIGURATION (due to backward compatibility) m=audio 49170 RTP/AVP 100 101 a=rtpmap:100 t38/8000 a=fmtp:100 T38FaxRateManagement=transferredTCF a=rtpmap:101 parityfec/8000 a=fmtp:101 49173 IN IP4 128.59.19.68 m=image 49172 tcp t38 a=T38FaxRateManagement:localTCF ; ; POTENTIAL CONFIGURATIONS a=tcap:1 RTP/AVP ; ITU-T T.38 FoRTP/UDP transport variant a=tcap:2 tcp ; ITU-T T.38 FoTPKT/TCP transport variant a=mcap:1 t38 ; ITU-T T.38 FoIP codec (subtype = 't38') ; Transport-independent ITU-T T.38 parameters a=acap:11 T38FaxVersion:4 ; Transport-dependent ITU-T T.38 parameters for RTP/UDP a=mcap:2 parityfec/8000 ; Forward Error Correction a=mfcap:2 T38FaxRateManagement=transferredTCF a=mfcap:2 49173 IN IP4 128.59.19.68 a=acap:12 (... additional ITU-T T.38 RTP attributes should be included, if required) ; Transport-dependent ITU-T T.38 parameters for TPKT/TCP a=acap:21 T38FaxRateManagement:localTCF a=acap:22 (... additional ITU-T T.38 TPKT attributes should be included) ; Preferences a=pcfg:1 t=1 m=1,2 pt=1:100,2:101 a=-ms:11,... a=pcfg:2 t=2 m=1 a=-ms:11,21,22,...
|

Offered (2) potential configurations:

  • • Preference 1: ITU-T T.38 FoRTP/UDP inclusive forward error correction method
  • • Preference 2: ITU-T T.38 FoTPKT/TCP
| +| 
 2) ANSWER (embedded in SIP 200 OK): ... a=acfg:1
|

The Answerer agrees to RTP/UDP transport and the correspondent parameter settings.

| + +#### D.2.4.2 SIP Invite for voice and facsimile call types + +##### D.2.4.2.1 Revised SDP Offer/Answer for voice/facsimile call types + +The voice and facsimile call represents a dual-state model (clause D.2.2.4.1) and shall always start in *Audio* mode according to clause D.2.2.4. Any possible transitioning to the *Fax relay* mode will occur then in a later stage (after successful call establishment) during the lifetime of the call. There are, consequently, at least two *media configurations* negotiated between Offerer and Answerer. However, the Fax relay mode represents in the dual-state model a *potential configuration*, and even a *latent configuration* (due to later usage). + +*Revised* SDP Offer/Answer shall be used consequently for such negotiations due to its support of such configuration concepts. + +##### D.2.4.2.2 Example 3 – Agreement on ITU-T G.711 audio and ITU-T T.38-over-RTP/UDP with RTP packet redundancy for ITU-T T.38 + +NOTE – This example was historically located in the section of "facsimile-only" calls (clause D.2.4.1 in previous ITU-T T.38 releases), but belongs to the "voice and facsimile" call types. + +For a two-party voice and fax call between gateways, when RTP encapsulation is used in conjunction with the UDP transport protocol: + +**Table D.6 – Example SIP/SDP encoding – "Example 3" in *Legacy* SDP Offer/Answer syntax** + +| SIP/SDP encoding | Comments | +|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------| +|

1) OFFER (here in SIP INVITE):

 C->S: INVITE sip:+1-212-555-1234@bell-tel.com SIP/2.0 Via: SIP/2.0/UDP kton.bell-tel.com From: A. Bell <sip:+1-519-555-1234@bell-tel.com> To: T. Watson <sip:+1-212-555-1234@bell-tel.com> Call-ID: 3298420296@kton.bell-tel.com Cseq: 1 INVITE Subject: Mr. Watson, here is a fax Content-Type: application/sdp Content-Length: ... v=0 o=faxgw1 2890844526 2890842807 IN IP4 128.59.19.68 e=+1-212-555-1234@bell-tel.com t=2873397496 0 c=IN IP4 128.59.19.68 m=audio 49170 RTP/AVP 121 0 100 a=rtpmap:100 t38/8000 a=fmtp:100 T38FaxRateManagement=transferredTCF a=rtpmap:121 red/8000 a=fmtp:121 100/100 m=image 49172 tcp t38 a=T38FaxRateManagement:localTCF
| | +|

2) ANSWER (here in SIP 200 OK):

 S->C: SIP/2.0 200 OK Via: SIP/2.0/UDP kton.bell-tel.com From: A. Bell <sip:+1-519-555-1234@bell-tel.com> To: T. Watson <sip:+1-212-555-1234@bell-tel.com> Call-ID: 3298420296@kton.bell-tel.com Cseq: 1 INVITE Contact: sip:watson@boston.bell-tel.com Content-Type: application/sdp Content-Length: ... v=0 o=faxwatson 4858949 4858949 IN IP4 192.1.1.2.3 c=IN IP4 boston.bell-tel.com m=audio 5002 RTP/AVP 121 0 100 a=rtpmap:100 t38/8000 a=fmtp:100 T38FaxRateManagement=transferredTCF a=rtpmap:121 red/8000 a=fmtp:121 100/100 m=image 0 tcp t38
| | + +This example shows redundant encoding for RTP fax as defined in [IETF RFC 2198]. For ITU-T G.711 encoding of voice, redundancy is not used. + +Table D.7 provides the encoding of example 3 in *Revised* SDP Offer/Answer syntax (just SDP syntax is illustrated, without the SIP header lines). + +**Table D.7 – Example SIP/SDP encoding – "Example 3" in *Revised* SDP Offer/Answer syntax** + +| SDP encoding (shortened SDP description) | Comments | +|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 
 1) OFFER (embedded in SIP INVITE): ... ; SESSION CONFIGURATIONs a=sescap:1 1,2 ; VoIP = ITU-T G.711, FoIP = ITU-T T.38 RTP/UDP a=sescap:2 1,3 ; VoIP = ITU-T G.711, FoIP = ITU-T T.38 TPKT/TCP  ; LATENT CONFIGURATIONs for ITU-T T.38 a=tcap:1 RTP/AVP ; ITU-T T.38 FoRTP/UDP transport variant a=tcap:2 tcp ; ITU-T T.38 FoTPKT/TCP transport variant a=mcap:2 t38 ; ITU-T T.38 FoIP codec (subtype = 't38') a=mcap:3 red/8000 ; RTP packet redundancy a=mfcap:3 %2%/2% ; RFC 2198 redundancy format (ITU-T T.38) a=mfcap:2 T38FaxRateManagement=transferredTCF a=acap:11 T38FaxVersion:4 ; Transport-dependent ITU-T T.38 parameters for RTP/UDP a=acap:12 (... additional ITU-T T.38 RTP attributes should be included, if required) ; Transport-dependent ITU-T T.38 parameters for TPKT/TCP a=acap:21 T38FaxRateManagement:localTCF a=acap:22 (... additional ITU-T T.38 TPKT attributes should be included) a=lcfg:2 mt=audio t=1 m=2,3 pt=2:121,3:100 a=-ms:11,... a=lcfg:3 mt=image t=2 m=2 a=-ms:11,...  ; ACTUAL CONFIGURATION (due to backward compatibility) m=audio 49170 RTP/AVP 121 0 100 a=rtpmap:100 t38/8000 a=fmtp:100 T38FaxRateManagement=transferredTCF a=rtpmap:121 red/8000 a=fmtp:121 100/100 m=image 49172 tcp t38 a=T38FaxRateManagement:localTCF ; ; POTENTIAL CONFIGURATION a=mcap:1 PCMU/8000 ; audio codec  ; Preferences a=pcfg:1 t=1 m=1 pt=1:0 a=-ms:
|

Offered (2) potential configurations (as session configurations due to 'voice' and 'facsimile'):

  • • Preference 1: Audio (PCMU) and ITU-T T.38 FoRTP/UDP inclusive packet redundancy
  • • Preference 2: Audio (PCMU) and ITU-T T.38 FoTPKT/TCP

The two ITU-T T.38 options are indicated as latent configurations. The audio mode is specified as "a=pcfg:1". There are consequently two session configurations indicated.

| +| 
 2) ANSWER (embedded in SIP 200 OK): ... a=sescap:1
|

The Answerer agrees to the 1st offered configuration.

| + +Figure D.4 below illustrates the two possible session configurations, *offered* in this example. + +![Figure D.4: Potential session configurations offered in example 3. The diagram shows two main sections: 'Audio mode (VoIP)' and 'Fax relay mode (ITU-T T.38 FoIP)'. The 'Audio mode' section contains an 'Audio codec' box with 'ITU-T G.711 μ-law without silence suppression and without RTP redundancy'. The 'Fax relay mode' section contains two 'Fax relay codecs' boxes: 'ITU-T T.38-RTP/UDP with RTP redundancy' and 'ITU-T T.38-TPKT/TCP'. A dashed box labeled 'Session configurations:' is connected to two lines, '1' and '2', which point to the connections between the audio codec and the fax relay codecs. Line '1' connects the audio codec to the 'ITU-T T.38-RTP/UDP' codec, and line '2' connects the audio codec to the 'ITU-T T.38-TPKT/TCP' codec.](a4de02b04a1a8f6cb8121ac2e11bf95a_img.jpg) + +T.38(15)\_FD.4 + +Figure D.4: Potential session configurations offered in example 3. The diagram shows two main sections: 'Audio mode (VoIP)' and 'Fax relay mode (ITU-T T.38 FoIP)'. The 'Audio mode' section contains an 'Audio codec' box with 'ITU-T G.711 μ-law without silence suppression and without RTP redundancy'. The 'Fax relay mode' section contains two 'Fax relay codecs' boxes: 'ITU-T T.38-RTP/UDP with RTP redundancy' and 'ITU-T T.38-TPKT/TCP'. A dashed box labeled 'Session configurations:' is connected to two lines, '1' and '2', which point to the connections between the audio codec and the fax relay codecs. Line '1' connects the audio codec to the 'ITU-T T.38-RTP/UDP' codec, and line '2' connects the audio codec to the 'ITU-T T.38-TPKT/TCP' codec. + +**Figure D.4 – Potential session configurations offered in example 3** + +###### **D.2.4.2.3 Example 4 – Multiple audio codecs, single ITU-T T.38 options** + +Multiple audio codec options may be offered for the "voice connection". Figure D.5 illustrates an example with ITU-T G.729 and ITU-T G.711 μ-law. + +![Figure D.5: Potential session configurations offered in example 4. The diagram shows two main sections: 'Audio mode (VoIP)' and 'Fax relay mode (ITU-T T.38 FoIP)'. The 'Audio mode' section contains two 'Audio codecs' boxes: 'ITU-T G.729 without silence suppression (T_p = 20 ms)' and 'ITU-T G.711 μ-law without silence suppression (T_p = 10 ms)'. The 'Fax relay mode' section contains one 'Fax relay codec' box: 'ITU-T T.38-UDPTL/UDP'. A dashed box labeled 'Session configurations:' is connected to two lines, '1' and '2', which point to the connections between the audio codecs and the fax relay codec. Line '1' connects the 'ITU-T G.729' codec to the 'ITU-T T.38-UDPTL/UDP' codec, and line '2' connects the 'ITU-T G.711 μ-law' codec to the 'ITU-T T.38-UDPTL/UDP' codec.](c649cad02e45d7d9a16f3f5bdb332219_img.jpg) + +T.38(15)\_FD.5 + +Figure D.5: Potential session configurations offered in example 4. The diagram shows two main sections: 'Audio mode (VoIP)' and 'Fax relay mode (ITU-T T.38 FoIP)'. The 'Audio mode' section contains two 'Audio codecs' boxes: 'ITU-T G.729 without silence suppression (T\_p = 20 ms)' and 'ITU-T G.711 μ-law without silence suppression (T\_p = 10 ms)'. The 'Fax relay mode' section contains one 'Fax relay codec' box: 'ITU-T T.38-UDPTL/UDP'. A dashed box labeled 'Session configurations:' is connected to two lines, '1' and '2', which point to the connections between the audio codecs and the fax relay codec. Line '1' connects the 'ITU-T G.729' codec to the 'ITU-T T.38-UDPTL/UDP' codec, and line '2' connects the 'ITU-T G.711 μ-law' codec to the 'ITU-T T.38-UDPTL/UDP' codec. + +**Figure D.5 – Potential session configurations offered in example 4** + +Table D.8 provides example SDP syntax. + +**Table D.8 – Example SIP/SDP encoding – "Example 4" in Revised SDP Offer/Answer syntax** + +| SDP encoding (shortened SDP description) | Comments | +|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 
 1) OFFER (embedded in SIP INVITE): ... ; SESSION CONFIGURATIONs a=sescap:1 1,3 ; VoIP = G.729, FoIP = ITU-T T.38 UDPTL/UDP a=sescap:2 2,3 ; VoIP = G.711, FoIP = ITU-T T.38 UDPTL/UDP  ; LATENT CONFIGURATION for T.38 a=tcap:2 udptl ; ITU-T T.38 FoUDPTL/UDP transport variant a=mcap:5 t38 ; ITU-T T.38 FoIP codec (subtype = 't38') a=acap:11 T38FaxVersion:4 a=acap:12 T38FaxRateManagement:transferredTCF a=acap:13 T38FaxUdpEC:t38UDPRedundancy a=acap:14 (... additional ITU-T T.38 attributes may be incl.) a=lcfg:3 mt=image t=2 m=5 a=11,12,13,14,...  ; ACTUAL CONFIGURATION (due to backward compatibility) ... ommitted ...  ; POTENTIAL CONFIGURATIONs a=tcap:1 RTP/AVP ; transport for VoIP a=acap:1 ptime:20 ; forITU-T G.729 a=acap:2 ptime:10 ; for ITU-T G.711 a=mcap:1 G729/8000 ; audio codec 1 a=mcap:2 PCMU/8000 ; audio codec 2 a=pcfg:1 t=1 a=-ms:1 m=1 pt=1:18 a=pcfg:2 t=1 a=-ms:1 m=2 pt=1:0
|

Offered (2) potential configurations (as session configurations due to 'voice' and 'facsimile'):

  • • Preference 1: Audio [ITU-T G.729] and fax relay (ITU-T T.38 FoUDPTL/UDP)
  • • Preference 2: Audio (PCMU) and fax relay (ITU-T T.38 FoUDPTL/UDP)

NOTE – The problem of audio codec individual packetization times of the legacy SDP Offer/Answer syntax is solved in revised SDP Offer/Answer by media-specific "a=acap:" attributes.

| +| 
 2) ANSWER (embedded in SIP 200 OK): ... a=sescap:2
|

The Answerer does not support ITU-T G.729 and agrees to the 2nd session configuration.

| + +##### D.2.4.2.4 Example 5 – SIP device with additional ITU-T V.152 support + +The SIP device may additionally support ITU-T V.152 VBDoIP (in comparison to example 4) as a media capability option for non-G3FE modem traffic. Both audio codec options (ITU-T G.729 and ITU-T G.711 $\mu$ -law) shall use the same packetization $T_p$ equals to 20 ms, without enabled silence suppression. ITU-T G.711 $\mu$ -law shall be also used as ITU-T V.152 VBD codec. Figure D.6 illustrates the resulting four possible session configurations. + +![Diagram showing potential session configurations for audio and VBD codecs. The top section, 'Audio codecs', contains 'Audio mode (VoIP)' with two options: 'ITU-T G.729 without silence suppression' and 'ITU-T G.711 μ-law without silence suppression'. The bottom section, 'VBD codec', contains 'Voiceband data mode (ITU-T V.152 VBDolP)' with two options: 'ITU-T G.711 μ-law' and 'ITU-T T.38-UDPTL/UDP'. A dashed box labeled 'Session configurations:' connects the two sections. Four numbered lines (1, 2, 3, 4) show the connections: 1 connects G.729 to G.711 μ-law; 2 connects G.711 μ-law to T.38-UDPTL/UDP; 3 connects G.729 to T.38-UDPTL/UDP; 4 connects G.711 μ-law to T.38-UDPTL/UDP. The bottom section is also labeled 'Fax relay mode (ITU-T T.38 FoIP)'.](29043c6ca27a7cfbc757a5d2eb029d33_img.jpg) + +T.38(15)\_FD.6 + +Diagram showing potential session configurations for audio and VBD codecs. The top section, 'Audio codecs', contains 'Audio mode (VoIP)' with two options: 'ITU-T G.729 without silence suppression' and 'ITU-T G.711 μ-law without silence suppression'. The bottom section, 'VBD codec', contains 'Voiceband data mode (ITU-T V.152 VBDolP)' with two options: 'ITU-T G.711 μ-law' and 'ITU-T T.38-UDPTL/UDP'. A dashed box labeled 'Session configurations:' connects the two sections. Four numbered lines (1, 2, 3, 4) show the connections: 1 connects G.729 to G.711 μ-law; 2 connects G.711 μ-law to T.38-UDPTL/UDP; 3 connects G.729 to T.38-UDPTL/UDP; 4 connects G.711 μ-law to T.38-UDPTL/UDP. The bottom section is also labeled 'Fax relay mode (ITU-T T.38 FoIP)'. + +**Figure D.6 – Potential session configurations *offered* in example 5** + +Table D.9 provides example SDP syntax. + +**Table D.9 – Example SIP/SDP encoding – "Example 5" in *Revised* SDP Offer/Answer syntax** + +| SDP encoding (shortened SDP description) | Comments | +|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 
 1) OFFER (embedded in SIP INVITE): ; SESSION CONFIGURATIONs a=sescap:1 1      ; VoIP = ITU-T G.729, VBDolP = ITU-T V.152 (ITU-T G.711) a=sescap:2 2      ; VoIP = ITU-T G.711, VBDolP = ITU-T V.152 (ITU-T G.711) a=sescap:3 3,5    ; VoIP = ITU-T G.729, FoIP = ITU-T T.38 UDPTL/UDP a=sescap:4 4,5    ; VoIP = ITU-T G.711, FoIP = ITU-T T.38 UDPTL/UDP  ; LATENT CONFIGURATION for ITU-T T.38 a=tcap:2 udptl    ; ITU-T T.38 FoUDPTL/UDP transport variant a=mcap:5 t38      ; ITU-T T.38 FoIP codec (subtype = 't38') a=acap:11 T38FaxVersion:4 a=acap:12 T38FaxRateManagement:transferredTCF a=acap:13 T38FaxUdpEC:t38UDPRedundancy a=acap:14 (... additional ITU-T T.38 attributes may be incl.) a=lcfg:5 mt=image t=2 m=5 a=11,12,13,14,...  ; ACTUAL CONFIGURATION (due to backward compatibility) ... omitted ... ; ; POTENTIAL CONFIGURATIONs a=tcap:1 RTP/AVP      ; transport for VoIP & VBDolP a=mcap:1 G729/8000     ; audio codec 1 a=mcap:2,3 PCMU/8000   ; audio codec 2 & VBD codec a=mscap:3 gpmv vbd=yes ; for V.152 PCMU a=pcfg:1 t=1 a=-ms m=1,3 pt=1:18,3:99 a=pcfg:2 t=1 a=-ms m=2,3 pt=2:0,3:99 a=pcfg:3 t=1 a=-ms m=1 pt=1:18 a=pcfg:4 t=1 a=-ms m=2 pt=2:0
|

Offered (4) potential configurations (as session configurations due to 'voice' and 'facsimile'):

  • • Preference 1: Audio [ITU-T G.729], VBD (ITU-T V.152 PCMU) & NTE [IETF RFC 4733]
  • • Preference 2: Audio (PCMU), VBD (ITU-T V.152 PCMU) & NTE [IETF RFC 4733]
  • • Preference 3: Audio [ITU-T G.729] and fax relay (ITU-T T.38 FoUDPTL/UDP)
  • • Preference 4: Audio (PCMU) and fax relay (ITU-T T.38 FoUDPTL/UDP)
| +| 
 2) ANSWER (embedded in SIP 200 OK): ... a=sescap:4
|

The Answerer prefers the 4th session configuration.

| + +##### D.2.4.2.5 Example 6 – Single audio codec, three ITU-T T.38 configurations concerning error correction methods + +The SIP device may offer the three ITU-T T.38 error correction methods as alternatives. [ITU-T G.729] shall be used for audio codec. Figure D.7 illustrates the resulting three possible session configurations. + +![Diagram showing potential session configurations for ITU-T T.38. It illustrates the connection between 'Audio mode (VoIP)' and 'Audio codecs' (ITU-T G.729) to 'Fax relay mode (ITU-T T.38 FoIP)'. Three session configurations (1, 2, 3) are shown, each linking the audio mode to a specific ITU-T T.38 configuration (C_T.38.1, C_T.38.2, or C_T.38.3). The configurations specify transport modes (UDPTL/UDP) and error correction methods (UDP redundancy, None, or FEC).](e2dad48ec062e71202459a9ab82261e4_img.jpg) + +T.38(15)\_FD.7 + +Diagram showing potential session configurations for ITU-T T.38. It illustrates the connection between 'Audio mode (VoIP)' and 'Audio codecs' (ITU-T G.729) to 'Fax relay mode (ITU-T T.38 FoIP)'. Three session configurations (1, 2, 3) are shown, each linking the audio mode to a specific ITU-T T.38 configuration (C\_T.38.1, C\_T.38.2, or C\_T.38.3). The configurations specify transport modes (UDPTL/UDP) and error correction methods (UDP redundancy, None, or FEC). + +**Figure D.7 – Potential session configurations offered in example 6** + +Figure D.8 provides the detailed parameter/value settings of ITU-T T.38 configurations $C_{T.38,1}$ , $C_{T.38,2}$ and $C_{T.38,3}$ . + +| Media "Voiceband data (if fax)" | | | +|------------------------------------------|------------------------------------------|------------------------------------------| +| ITU-T T.38 configuration $C_{T.38,1}$ : | ITU-T T.38 configuration $C_{T.38,2}$ : | ITU-T T.38 configuration $C_{T.38,3}$ : | +| 0) T38 transport mode = UDPTL/UDP | 0) T38 transport mode = UDPTL/UDP | 0) T38 transport mode = UDPTL/UDP | +| 1) T38FaxVersion = 4 | 1) T38FaxVersion = 4 | 1) T38FaxVersion = 4 | +| 2) T38MaxBitRate = 14400 | 2) T38MaxBitRate = 14400 | 2) T38MaxBitRate = 14400 | +| 3) T38FaxFillBitRemoval = FALSE | 3) T38FaxFillBitRemoval = FALSE | 3) T38FaxFillBitRemoval = FALSE | +| 4) T38FaxTranscodingMMR = FALSE | 4) T38FaxTranscodingMMR = FALSE | 4) T38FaxTranscodingMMR = FALSE | +| 5) T38FaxTranscodingJBIG = FALSE | 5) T38FaxTranscodingJBIG = FALSE | 5) T38FaxTranscodingJBIG = FALSE | +| 6) T38FaxRateManagement = transferredTCF | 6) T38FaxRateManagement = transferredTCF | 6) T38FaxRateManagement = transferredTCF | +| 7) T38FaxMaxBuffer = 1800 | 7) T38FaxMaxBuffer = 1800 | 7) T38FaxMaxBuffer = 1800 | +| 8) T38FaxMaxDatagram = 150 | 8) T38FaxMaxDatagram = 150 | 8) T38FaxMaxDatagram = 150 | +| 9) T38FaxUdpEC = t38UDPRedundancy | 9) T38FaxUdpEC = t38UDPNoEC | 9) T38FaxUdpEC = t38UDPFEC | +| 10) T38VendorInfo = - | 10) T38VendorInfo = - | 10) T38VendorInfo = - | +| 11) T38ModemType = t38G3FaxOnly | 11) T38ModemType = t38G3FaxOnly | 11) T38ModemType = t38G3FaxOnly | + +T.38(15)\_FD.8 + +(NOTE – The three SDP parameters $T38FaxMaxIFP$ , $T38FaxUdpECDepth$ and $38FaxUdpFECMaxSpanare$ not shown in this example). + +**Figure D.8 – ITU-T T.38 configurations $C_{T.38,1}$ , $C_{T.38,2}$ and $C_{T.38,3}$ (used for session configurations) in example 6** + +Table D.10 provides example SDP syntax. + +**Table D.10 – Example SIP/SDP encoding – "Example 6" +in revised SDP Offer/Answer syntax** + +| SDP encoding (shortened SDP description) | Comments | +|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 
 1) OFFER (embedded in SIP INVITE): ; SESSION CONFIGURATIONS a=sescap:1 1,3 ; VoIP = G.729, FoIP = ITU-T T.38 UDPTL/UDP with packet red a=sescap:2 1,4 ; VoIP = G.729, FoIP = ITU-T T.38 UDPTL/UDP with NoEC a=sescap:3 1,5 ; VoIP = G.729, FoIP = ITU-T T.38 UDPTL/UDP with FEC  ; LATENT CONFIGURATION for ITU-T T.38 a=tcap:2 udptl ; ITU-T T.38 FoUDPTL/UDP transport variant a=mcap:5 t38 ; ITU-T T.38 FoIP codec (subtype = 't38') a=acap:11 T38FaxVersion:4 a=acap:12 T38MaxBitRate:14400 ; Note: the exclusion of attributes " T38FaxFillBitRemoval", " T38FaxTranscodingMMR" and " T38FaxTranscodingJBIG" means value "FALSE" (see [IETF RFC 4612]). a=acap:16 T38FaxRateManagement:transferredTCF a=acap:17 T38FaxMaxBuffer:1800 a=acap:18 T38FaxMaxDatagram:150 a=acap:19 T38ModemType:t38G3FaxOnly a=acap:21 T38FaxUdpEC:t38UDPRedundancy ; error correction scheme 1 a=acap:22 T38FaxUdpEC:t38UDPNoEC ; error correction scheme 2 a=acap:23 T38FaxUdpEC:t38UDPFEC ; error correction scheme 3 a=lcfg:3 mt=image t=2 m=5 a=11,12,16,17,18,19,21 ; ITU-T T.38  configuration #1 a=lcfg:4 mt=image t=2 m=5 a=11,12,16,17,18,19,22 ; ITU-T T.38  configuration #2 a=lcfg:5 mt=image t=2 m=5 a=11,12,16,17,18,19,23 ; ITU-T T.38  configuration #3  ; ACTUAL CONFIGURATION (due to backward compatibility) ... omitted ... ; ; POTENTIAL CONFIGURATIONS a=tcap:1 RTP/AVP ; transport for VoIP a=acap:1ptime:10 ; for ITU-T G.711 a=mcap:1 G729/8000 ; audio codec 1 a=pcfg:1 t=1 a=-ms:1 m=1 pt=1:18
|

Offered (4) potential configurations (as session configurations due to 'voice' and 'facsimile'):

  • • Preference 1: Audio [ITU-T G.729] and fax relay (ITU-T T.38 FoUDPTL/UDP with error correction method "t38UDPRedundancy") i.e., ITU-T T.38 using packet redundancy as error correction
  • • Preference 2: Audio [ITU-T G.729] and fax relay (ITU-T T.38 FoUDPTL/UDP with error correction method "t38UDPNoEC") i.e., ITU-T T.38 without any error correction
  • • Preference 3: Audio [ITU-T G.729] and fax relay (ITU-T T.38 FoUDPTL/UDP with error correction method "t38UDPFEC") i.e., ITU-T T.38 using forward error correction as error correction
| +| 
 2) ANSWER (embedded in SIP 200 OK): ... a=sescap:1
|

The Answerer prefers the 1st session configuration.

| + +### D.2.5 Minimum call set-up messages + +The implementation of this annex shall support the minimum requirements for a SIP client and server as defined in [IETF RFC 3261] sections A.1 and A.2. + +All clients **MUST** be able to generate the INVITE and ACK requests. Clients **MUST** generate and parse the Call-ID, Content-Length, Content-Type, CSeq, From and To headers. Clients **MUST** also parse the Require header. A minimal implementation **MUST** understand SDP ([IETF RFC 2327]). It **MUST** be able to recognize the status code classes 1 through 6 and act accordingly. + +A minimally compliant server implementation **MUST** understand the INVITE, ACK, OPTIONS and BYE requests. A proxy server **MUST** also understand CANCEL. It **MUST** parse and generate, + +as appropriate, the Call-ID, Content-Length, Content-Type, CSeq, Expires, From, Max-Forwards, Require, To and Via headers. It MUST echo the CSeq and Timestamp headers in the response. It SHOULD include the Server header in its responses. + +### D.2.6 Mapping of call progress signals + +For call set-up and call progress, the return signals can be simplified to the following set (see Table D.11). These are all returned prior to or instead of a 200 OK response to the INVITE request. + +**Table D.11 – Call progress mapping** + +| Meaning | SIP response mapping | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------| +| Busy1. Subscriber busy tone as defined in [ITU-T E.180]. | 486 Busy here | +| Busy2. Sometimes referred to as Distinctive Busy on some PABX models. | 486 Busy here | +| Congestion busy as defined in [ITU-T E.180]. | 600 Busy everywhere | +| Ring1. Ringing tone as defined in [ITU-T E.180]. This is an intermediate call progress indicator. It can be used to generate a ringback signal to the originating G3FE as if it there were an end-to-end PSTN connection. | 180 Ringing | +| Ring2. Ringing tone similar to Ring1 where two short rings are generated instead of one long ring. This is an intermediate call progress result. | 180 Ringing | +| SIT Intercept. Special information tones are defined in [ITU-T E.180]. Intercept tone is one combination of tones – frequency and duration. | 503 Service unavailable | +| SIT vacant. Special information tones are defined in [ITU-T E.180]. Circuit vacant tone is one combination of tones – frequency and duration. | 503 Service unavailable | +| SIT Reorder. Special information tones are defined in [ITU-T E.180]. Reorder tone is one combination of tones – frequency and duration. | 503 Service unavailable | +| SIT No Circuit. Special information tones are defined in [ITU-T E.180]. No Circuit tone is one combination of tones – frequency and duration. | 503 Service unavailable | +| NOTE – SIT tones are not distinguished because this generally indicates a problem with the number dialled. | | + +The SIP 200 OK message in response to an INVITE request is returned when the gateway, *by some means*, determines that a connection to the terminal G3FE has been established. If CED or FSK flags are detected, the appropriate ITU-T T.38 messages can be sent. + +### D.2.7 DTMF transmission + +SIP can transfer collected DTMF dialling digits as a SIP URL as defined in [IETF RFC 3261] section 2: + +sip:+1-212-555-1212@gateway.com;user=phone + +DTMF transmission during an established voice and facsimile connection may be completed using the RTP tone payload described in [IETF RFC 4733]. + +### D.2.8 Interoperability + +Both SIP and Annex B require a well-known port to initiate call signalling. As described in SIP, its well-known port is 5060. Endpoints in this annex shall use the SIP well-known port by default. + +#### **D.2.8.1 Fall-back procedure** + +In case of an unsuccessful negotiation of an ITU-T T.38 session between gateways, it is recommended that, in order to maximize the success rate of facsimile calls in GSTN, gateways should fall back to ITU-T V.152 with ITU-T G.711 as VBD codec. If ITU-T V.152 is not an available mode, then non-ITU-T V.152 audio with ITU-T G.711 codec is a possible alternative. One example of achieving this is described in D.2.4.2.4. + +# Annex E + +## ITU-T H.248.1 call establishment procedures + +(This annex forms an integral part of this Recommendation.) + +## E.1 Introduction + +This annex describes system level requirements and procedures for Internet-aware facsimile implementations and Internet-aware facsimile gateways conforming to ITU-T T.38 to establish calls with other ITU-T T.38 implementations using [ITU-T H.248.1] and either one of the following procedures: + +- a) A media gateway controlled paradigm via the procedures defined by [ITU-T H.248.1]. This paradigm shall be referred to as the *T.38 MGC Transitioning method*. Using this method, a call is set up using the normal procedures as described in [ITU-T H.248.1], but if ITU-T T.38 has to be supported, the packages as described in [ITU-T H.248.2] are taken into account, so that the detection and generation of fax tones are enabled. Upon detection of fax signals, the MGC is notified by the emitting MG about the event, and gives the command to the receiving part via its controlling MGC to generate the signals. Answering signals are handled in the same way. When all signals needed are communicated between both fax terminals via the MGs and MGCs, the MGCs will modify the contexts to put them into fax-mode. This scenario can take up to 20 Megaco commands. +- b) A paradigm that allows for transitioning between a VoIP call and a FoIP call (using ITU-T T.38) by media gateways (MG) that support ITU-T T.38 without the real-time intervention of a media gateway controller (MGC). Note that throughout this annex the term "media gateway controller" is used as to indicate a MGC as defined in [ITU-T H.248] as well as a gatekeeper as defined in [ITU-T H.323]. The only involvement of the MGC will be during initial connection capabilities negotiation between the media gateways using SDP descriptors. At this stage, both the MGs and the MGCs are unaware of the type of connection (i.e., voice, fax, modem, etc.). The mechanism in this alternative is an optional procedure that complements the existing mechanisms in Annex B (ITU-T H.323 procedures), Annex D (SIP-SDP procedures), Annex E (ITU-T H.248.1 procedures), and Annex D of [ITU-T H.323]. This paradigm shall be referred to as the *ITU-T T.38 Autonomous Transitioning method*. + +## E.2 Communication between gateways + +### E.2.1 Overview + +#### E.2.1.1 Gateway architecture + +The method described in this annex is intended for use in conjunction with other methods in a decomposed gateway model as shown in Figure E.1. In this model, the media gateway controller (MGC) has knowledge of all the endpoints within a domain and has control over connections being created and terminated at its media gateways (MG). + +![Figure E.1 – Typical decomposed model. This diagram illustrates a network architecture for facsimile communication over IP. On the left, a PSTN cloud is connected to a fax machine icon. Above the PSTN are blocks for SS7 and SG. Below them are blocks for MGC and MG. On the right, a similar structure exists with SS7, SG, MGC, and MG blocks, also connected to a PSTN cloud and a fax machine icon. A central cloud labeled 'IP network' connects the two MG blocks. Dashed lines show signaling paths: a solid line from the left MGC to the left MG, a solid line from the right MG to the right MGC, and a dashed line from the left MG to the right MG through the IP network. A label 'T.38_FE.1' is located at the bottom right of the diagram.](e404de9a69c05473fbd6af28ee32311b_img.jpg) + +Figure E.1 – Typical decomposed model. This diagram illustrates a network architecture for facsimile communication over IP. On the left, a PSTN cloud is connected to a fax machine icon. Above the PSTN are blocks for SS7 and SG. Below them are blocks for MGC and MG. On the right, a similar structure exists with SS7, SG, MGC, and MG blocks, also connected to a PSTN cloud and a fax machine icon. A central cloud labeled 'IP network' connects the two MG blocks. Dashed lines show signaling paths: a solid line from the left MGC to the left MG, a solid line from the right MG to the right MGC, and a dashed line from the left MG to the right MG through the IP network. A label 'T.38\_FE.1' is located at the bottom right of the diagram. + +**Figure E.1 – Typical decomposed model** + +The mechanism in this annex complements the mechanism of Annex D of [ITU-T H.323] (which describes a simple case without a decomposed gateway). In the situation where more than one MGC is involved in a call, the mechanism in this annex (other methods are for further study) is used to signal between them. + +#### **E.2.1.2 Call set-up** + +Call set-up for implementations compliant to this annex is based on [ITU-T H.248.1]. As in the basic Annex B, implementations may operate in two distinct compatible environments: + +- 1) A facsimile-only over IP environment – In this environment, no voice support is provided. The procedures and requirements of clause D.2.2.1 shall apply to implementations operating in this environment. +- 2) A facsimile and voice over IP environment – The procedures and requirements of clause E.2.2.2 shall apply to implementations operating in this environment. + +#### **E.2.1.3 Media channels** + +ITU-T T.38 facsimile packets are sent on a separate TCP/UDP port from ITU-T H.248 message transport. A minimal implementation of this annex requires a TCP, UDP or SCTP port for call signalling (ITU-T H.248 message) transport and either a UDP port or a TCP port for ITU-T T.38 facsimile information. + +### **E.2.2 Basic call set-up** + +According to clause 8.2.1 of [ITU-T H.248.1]: + +- the connection model for the protocol describes the logical entities, or objects, within the media gateway that can be controlled by the media gateway controller. The main abstractions used in the connection model are Terminations and Contexts; +- a *termination* is an object that sources and/or sinks media streams; +- a *context* represents a collection of *terminations* in a single conference. + +Terminations recognize events that invoke a response by the MGC to create another event (e.g., recognizing off-hook invokes play dial tone). This interaction proceeds throughout a typical call set-up process initiated at the MG (e.g., [ITU-T H.323] Fast Connect Setup). + +It shall be possible to establish a facsimile over IP call using either of the following two mechanisms: + +- 1) *ITU-T T.38 MGC transitioning method*: A mechanism in which the MGC decides when and whether it is possible to transition from VoIP to ITU-T T.38 FoIP based in tone events sent to it (via [ITU-T H.248] and the packages described in Annex F of [ITU-T H.248.1]) by the MGs. For [ITU-T H.248] it is described in clause E.2.2.1. In an ITU-T H.323 environment, the replacement of a voice channel with a ITU-T T.38 channel is done according to the procedures of clause D.5 of [ITU-T H.323]. +- 2) *ITU-T T.38 autonomous transitioning method*: A mechanism for transitioning between a VoIP call and a FoIP call (using ITU-T T.38) by MGs without the intervention of a media gateway controller (MGC), as described in clause E.2.2.2, or without the need to request modification of a call as described in Annex D (SIP/SDP). Note that the packages described in [ITU-T H.248.2] are not needed when supporting this method. In an ITU-T H.323 environment, the procedures of clause D.3 of [ITU-T H.323] (fastStart) or clause D.4 of [ITU-T H.323] (non-fastStart) are used to set up two parallel channels. + +A MG shall indicate support of the *ITU-T T.38 autonomous transitioning method* by including in the initial capabilities exchange or set-up message support for both audio and image/t38 media streams, using the mechanisms described below. + +Media gateways that use SDP (see [IETF RFC 2327]) to exchange capabilities (such as, but not limited to, SIP or ITU-T H.248 MGs), shall indicate support for the *ITU-T T.38 autonomous transitioning method* by including in the first SDP to be exchanged at least two media descriptors (i.e., "m=..." lines), one of type audio and one media descriptor of type image/t38, in which the port number is not set to zero (this is for compatibility with SIP terminals, for which setting the port to zero means non-support of that media type). This is illustrated in the following examples, which show only the SDP portion and in which only the media line is important. Also, note that when using [ITU-T H.248], the media descriptors must be separated by a version descriptor (aka v-line), as shown in Appendix III: + +NOTE – All examples in this annex illustrate the ITU-T H.248 text encoding method, which uses SDP syntax in the ITU-T H.248 local and remote descriptors. All SDP information elements as defined for ITU-T T.38 (see Annex D) may be also used in ITU-T H.248 signalling. The examples below illustrate typically just a subset (indicated by "*additional attributes may be included*"). + +- SDP examples illustrating support of the *ITU-T T.38 autonomous transitioning method*: + +#### - Example 1: + +``` +v=0 +c=IN IP4 124.124.124.222 +m=audio 2222 RTP/AVP 0 +(... additional attributes may be included) +m=image 4444 udptl t38 +a=T38FaxVersion:1 +a=T38FaxRateManagement:transferredTCF +a=T38FaxUdpEC:t38UDPFEC +a=T38FaxMaxBuffer:2000 +a=T38FaxMaxDatagram:512 +a=T38MaxBitRate:14400 +(... additional attributes may be included) +``` + +#### - Example 2: + +``` +v=0 +c=IN IP4 124.124.124.222 +m=audio 2222 RTP/AVP 0 8 13 +a=ptime:20 +``` + +``` + +(... additional attributes may be included) + +m=audio 1111 RTP/AVP 18 129 +a=ptime:10 +a=rtpmap:129 telephone-event/8000 +a=fmtp:129 0-15 +(... additional attributes may be included) +m=image 4444 udptl t38 +a=T38FaxRateManagement:transferredTCF +a=T38FaxUdpEC:t38UDPFEC +(... additional attributes may be included) + +``` + +- SDP examples illustrating non-support of the ITU-T *T.38 autonomous transitioning method*: + +#### - Example 3: + +``` + +v=0 +c=IN IP4 124.124.124.222 +m=audio 2222 RTP/AVP 0 8 13 140 +a=ptime:20 +a=rtpmap:140 telephone-event/8000 +a=fmtp:140 0-15 +(... additional attributes may be included) +m=image 0 udptl t38 +a=T38FaxRateManagement:transferredTCF +a=T38FaxUdpEC:t38UDPFEC +a=T38FaxMaxBuffer:1536 +a=T38FaxMaxDatagram:512 +(... additional attributes may be included) + +``` + +#### - Example 4: + +``` + +v=0 +c=IN IP4 124.124.124.222 +m=audio 2222 RTP/AVP 0 8 13 140 +a=ptime:20 +a=rtpmap:140 telephone-event/8000 +a=fmtp:140 0-15 +(... additional attributes may be included) + +``` + +#### - Example 5: + +``` + +v=0 +c=IN IP4 124.124.124.222 +m=image 8190 udptl t38 +a=T38FaxVersion:0 +a=T38FaxRateManagement:transferredTCF +a=T38FaxUdpEC:t38UDPFEC +a=T38FaxMaxBuffer:2000 +(... additional attributes may be included) + +``` + +Note that examples 3 and 4 shall be construed as indicating that, at the instance of time the SDP was exchanged, the *ITU-T T.38 autonomous transitioning method* shall not be used, as well as indicating that the media gateway that sent the SDP does not support (at that instance of time) ITU-T T.38. In such a case, the call will proceed as mandated by the call establishment control protocol being used (which may be, but not limited to [ITU-T H.323], SIP, or [ITU-T H.248]); if it is [ITU-T H.248], then the procedures in clause E.2.2.1 shall be used. Also, note that, although in examples 3 and 4 the SDP does not indicate support of ITU-T T.38, this does not mean that either the MG or the MGC cannot request, at a later stage of the call, to transition to ITU-T T.38 by sending a new SDP + +(for example within an ITU-T H.248 Modify command or a SIP INVITE command) containing a media attribute of type image/t38 (as described either in Annex D or in clause E.2.2.1). + +Example 5 will cause both MGs to immediately transition to FoIP (using ITU-T T.38); however, any future transitioning to any other mode of operation (e.g., voice, voiceband data, etc.) shall be controlled by the MGC. + +An ITU-T H.323-capable media gateway shall indicate support of the *ITU-T T.38 autonomous transitioning method* during the ITU-T H.245 capabilities exchange by opening two parallel channels in each direction, one for voice, the other for ITU-T T.38, as described in clause D.3 of [ITU-T H.323] for fastStart, or in clause D.4 of [ITU-T H.323] for non-fastStart. Two MGs that mutually support the *ITU-T T.38 autonomous transitioning method* shall autonomously, on detection of the appropriate facsimile signals or on reception of a ITU-T T.38 UDP (or TCP) packet at its ITU-T T.38 UDP (or TCP) port, mute the audio channel and transition to the ITU-T T.38 channel. + +The media gateway controller shall decide at the start of the call which method to use (i.e., whether to control the transitioning from audio to facsimile or to let the MGs autonomously transition), based on data derived from capability messages exchanged as described above between the media gateways. + +Hence, the MGC shall not control the transition between VoIP and FoIP only if both MGs that are establishing the connection have mutually indicated that they support the *ITU-T T.38 autonomous transitioning method* (by the means described above). Note that in ITU-T H.323 fastStart, there is no explicit negotiation of which method to use, autonomous or MGC-based: the fastStart element will indicate that the call is either a pure voice call (which may turn out eventually to be switched to a ITU-T T.38 call using clause D.5 of [ITU-T H.323]), or it may consist of a separate channel for voice and a separate channel for ITU-T T.38 as per clause D.3 of [ITU-T H.323]. The latter shall be used by an MGC (i.e., gatekeeper) as indication that the MGs shall use the *ITU-T T.38 autonomous transitioning method*. When non-fastStart procedures are used, the terminal capability negotiation will indicate if ITU-T T.38 and voice can be used simultaneously or not (the terminal capability negotiation procedures may also be used after a fastStart call set-up, and will be instrumental in indicating that the autonomous or MGC switchover procedures are supported). + +Absence of a MG indicating support of the *ITU-T T.38 autonomous transitioning method* must be construed, by both the MGs and the MGCs, as an indication to use the existing call establishment procedures which depend on the call control protocol being used (SIP, [ITU-T H.323] or [ITU-T H.248]), which can be one of the following: + +- *ITU-T T.38 MGC transitioning method* (for [ITU-T H.248]) described in clause E.2.2.1; +- the method described in Annex B (ITU-T H.323 procedures); +- the procedure described in Annex D (SIP/SDP procedures). + +The fact that a MGC knows that the *ITU-T T.38 autonomous transitioning method* shall be used for a particular call does not preclude the possibility of the MGC to request to receive notifications from the MGs indicating detection of facsimile tones or transition to FoIP (using ITU-T T.38). The possible usage of such notifications is out of the scope of this Recommendation. + +#### **E.2.2.1 ITU-T T.38 media gateway controller (MGC) method** + +Note that two cases exist for the use of this mechanism: + +- 1) If the call agent (MGC & gatekeeper) controls both MGs, then [ITU-T H.248] and the packages described in Annex F of [ITU-T H.248.1] are used to modify the existing connection between the two MGs. + +- 2) If different call agents are involved (e.g., when two different service providers are involved in completing a call), then MGC-MGC communication is required (i.e., using the mechanism of Annex D). On confirmation of a connection, the on-ramp call agent instructs its media gateway (via [ITU-T H.248]) to initiate a ITU-T T.38 session with the off-ramp MG. + +This method of transitioning from VoIP to FoIP shall be the default method unless the MGs have indicated mutual support of the *ITU-T T.38 autonomous transitioning method* using the mechanisms described in this clause. + +##### **E.2.2.1.1 Facsimile-only connection** + +Digits are collected by the media gateway (MG) and sent to the calling agent to invite the called party on a facsimile call. + +Once connected, the call proceeds as in Annex B. + +##### **E.2.2.1.2 Voice and facsimile connection** + +Digits are collected by the media gateway (MG) and sent to the calling agent to invite the called party to a voice connection as defined in [ITU-T H.248.1]. A voice connection is set up. + +Upon detection of CNG by the emitting media gateway (MG), the calling agent is informed (via [ITU-T H.248.1]) of this event and instructs the destination MG to play CNG. If the destination MG then notifies the MGC of a CED (or ITU-T V.21 flags) event and is capable of ITU-T T.38, the MGC requests that each MG open a ITU-T T.38 connection. Details for discrimination of the call as facsimile is described in clause 8 of [ITU-T H.248.2]. The MGC may also request that a new MG handle the facsimile connection. The ITU-T T.38 protocol proceeds with a ITU-T T.38 ITU-T V.21 flags indicator packet. + +Note that if ITU-T T.38 is not supported by one of the MGs, the MGC may choose to abort a fax relay connection and attempt to make a connection over a conditioned audio channel, using procedures and methods as defined in ITU-T V.152. Note also that it is possible that legacy systems may use a pass-through service with non-ITU-T V.152/G.711 codec configurations. + +Full flexibility of switching between MGs (e.g., voice+facsimile, voice-only or facsimile-only) and deciding on options will not be possible if the MGC is not notified of the facsimile events (and the MG alone detects facsimile and switches blindly to ITU-T T.38). Upon completion of the facsimile call (ITU-T T.38 completion) by the off-ramp media gateway (MG), the calling agent is informed (via [ITU-T H.248.1]) of this event and may request that the connection be reverted to voice. + +#### **E.2.2.2 ITU-T T.38 autonomous transitioning method** + +To use this method, the MGs must mutually agree to do so at the start of the call. Refer to clause E.2.2 (Basic call set-up) for the mechanisms to be used by an MG to indicate to the MGC and the remote MG that it supports the ITU-T T.38 autonomous transitioning method. + +The MG will negotiate at the start of the call all possible media descriptors; thus, an audio descriptor and an image/t38 descriptor would both be included. Therefore, ITU-T T.38 options of a subsequent fax phase to the call are negotiated at the same time as the audio parameters. + +Note that for the case of using ITU-T H.248 call set-up procedures, the fact that both MGs may have indicated in the audit that they support ITU-T T.38 as well as audio (and responded with two media descriptor lines) shall not be used as an indication of support of the ITU-T T.38 autonomous transitioning method. + +It shall be in the creation of a context where support of the ITU-T T.38 autonomous transitioning method is indicated. Hence, the ITU-T H.248 MGC will need to include both an audio and an image + +descriptor in the Local descriptor portion of the Add Ephemeral command (refer to clause III.2.2 3) for an example, with the port numbers set to \$, and with the ReserveGroup property, of the LocalControl descriptor, set to True, thus effectively asking the MGs to reserve resources for both the image and audio descriptors. However, if for some reason, (e.g., lack of resources) both audio and image resources cannot be reserved at the time of the start of the call, the image media descriptor, within the response SDP, shall either have its port set to zero (recommended for compatibility with SIP capable terminals) or be omitted altogether, thus indicating non-support of the ITU-T T.38 autonomous transitioning method as well as initializing the call as voice, and hence by default both gateways and the media gateway controller shall use the *MGC method*. + +##### **E.2.2.2.1 Facsimile-only connection** + +Digits are collected by the media gateway (MG) and sent to the calling agent to invite the called party on a facsimile call. + +Once connected, the call proceeds as in Annex B. + +##### **E.2.2.2.2 Voice and facsimile connection** + +Digits are collected by the media gateway (MG) and sent to the calling agent to invite the called party to a voice connection as defined in [ITU-T H.248.1]. Because the MGC and the MGs have no indication that a call is going to be voice or facsimile, the MGs shall set up a voice connection and no ITU-T T.38 packets are sent. The MGs remain in this mode until they detect such criteria (refer to clause E.2.2.2.2.1) that cause them to determine that a fax call is starting. At this point, the MGs shall start the image/t38 connection and mute the audio connection. The MGs will remain in fax mode until they detect such criteria that cause them to determine that the fax transmission is complete, at which point they will mute the image/t38 connection and re-enable the audio/RTP connection. This process may continue indefinitely until the call is terminated. + +###### **E.2.2.2.2.1 MG-to-MG signalling of facsimile tones/signals** + +When using voice high-compression encoding techniques such as, but not limited to, [ITU-T G.729], some fax tonal signals may not get correctly transported across the packet network. Hence, it is recommended that a gateway detect these signals and transport them across the packet network via other mechanisms. The following methods exist to pass information about the detected signals and tones to the peer fax terminal over the packet network: + +###### *Method 1* + +Tone pass through: The tone is sent in-band using a lower compression algorithm such as the one used for voiceband data (VBD), e.g., encoded using ITU-T G.711 or ITU-T G.726-32k over RTP/UDP/IP. + +Upon detection of a tone, the MG switches autonomously to VBD, in which mode an appropriate codec is used (e.g., [ITU-T G.711]), and passes the tone in the voice RTP payload. The receiving gateway has to detect the tone from the packet network, and has to switch to VBD, to pass the signal to the fax terminal. + +This method should only be used if both media gateways have indicated support of a common lower compression codec or support of the VBD state. The mechanisms used for indicating such support may be via SDP exchange or other mechanisms, which are outside the scope of this Recommendation. + +###### *Method 2* + +Tone relay (see [IETF RFC 4733] – RTP Payload for DTMF Digits, telephony tones and telephony signals). + +All information needed to regenerate the tone is passed in the RTP payload. The BIWF in the peer MG has to generate the tones towards the fax terminal. + +Before using this method, it is recommended that media gateways should mutually indicate support of this method via SDP ([IETF RFC 2327]) exchange or other call capability exchange mechanisms, which are beyond the scope of this Recommendation. + +A gateway that does not support this RTP payload type must be capable of discarding these packets without affecting its operation. + +###### *Method 3* + +Tone detection indication ([IETF RFC 4733] – RTP Payload for DTMF Digits, telephony tones and telephony signals): + +Event messages (NTE) are used to pass events as described in [IETF RFC 4733], chapter 3.11 (Data modems and Fax Events). The peer MG may use this message to switch to VBD or ITU-T T.38, dependent on the current state, and shall generate the tones with the characteristics as described in [ITU-T T.30]. + +When using this method, the following events are to be sent, as defined in Table 3 of [IETF RFC 4733]: + +###### **Event Encoding (decimal)** + +ANS (=CED) 32 + +CNG 36 + +V.21 channel 2, "0" bit 39 (see Note) + +V.21 channel 2, "1" bit: 40 (see Note) + +NOTE – In the superseded [b-IETF RFC 2833] used in versions of this annex approved before 2010, there existed no IETF RFC 2833 event for ITU-T V.21 preamble flags. Only ITU-T V.21 channel 2, bit "0" and bit "1" events existed, which are passed to the transmitting MG. To be able to discriminate between a fax and a data call, the receiving MG must be able to decode the preamble flag, out of the RTP NTE messages. However, IETF RFC 4734 (which is one of the IETF RFCs which obsoletes IETF RFC 2833), provides an event for the ITU-T V.21 preamble flag that has the value 54 (decimal). It is recommended that implementations use the IETF RFC 4734 ITU-T V.21 preamble flag event instead of the ITU-T V.21 channel 2 bit "0" and bit "1" events needed in earlier implementations. + +The number of flags to be detected before switchover is a parameter which must be chosen in such a way that the receiving MG sends enough IETF RFC 4733 messages towards the transmitting MG, before it switches to ITU-T T.38. + +After the switchover to ITU-T T.38, the ITU-T V.21 flags are passed over UDPTL. + +Before using this method, it is recommended that media gateways should mutually indicate support of the RTP payload types indicated above via SDP exchange or other call capability exchange mechanisms, which are beyond the scope of this Recommendation. + +A gateway that does not support these RTP payload types must be capable of discarding these packets without affecting its operation. + +###### *Method 4* + +After switchover to ITU-T T.38, if the tonal signals still exist, then the media gateway shall send ITU-T T.38 packets of Type t30-indicator, to signal the presence of facsimile signals. + +###### E.2.2.2.2.2 VoIP to FoIP transition criteria + +Upon detection of CNG by the emitting media gateway (MG), it is possible to determine with sufficient confidence that it is a facsimile call because CNG is only sent by a G3FE. Hence, if a ITU-T T.38 capability has been mutually successfully negotiated between the MGs, the MG will switch to ITU-T T.38 and, in accordance with the ITU-T T.38 protocol, transmit to the remote MG the ITU-T T.38 CNG indicator packet. The remote MG will switch to ITU-T T.38, on receipt at its ITU-T T.38 UDP (or TCP) port, of the ITU-T T.38 CNG indicator packet. + +When in audio/RTP mode, receipt of any ITU-T T.38 packet at a designated ITU-T T.38 UDP (or TCP) port should be a criterion for switching to image/t38 mode (see clause E.2.2.2.2.1). The implementation of how this is done is out of the scope of this Recommendation. However, one recommended method is that of which, receipt at its local ITU-T T.38 UDP (or TCP) port of a valid UDP (or TCP) packet can be assumed to be a ITU-T T.38 packet and hence cause autonomous transition to ITU-T T.38, if the source IP address of that packet corresponds with that of the remote MG, with which the ITU-T T.38 autonomous transitioning method (as well as the ITU-T T.38 capabilities) was mutually successfully negotiated, because only ITU-T T.38 UDPTL packets must be sent to negotiated image/t38 UDP port number. The same applies for ITU-T T.38 TCP packets. The ITU-T T.38 UDP (or TCP) port should only be activated if the ITU-T T.38 autonomous transitioning method (and a mutual set of ITU-T T.38 capabilities) is supported by the MGs establishing the call. (This would avoid falsely transitioning autonomously to ITU-T T.38 on receipt of any valid UDP packet if ITU-T T.38 autonomous transitioning method is not mutually supported between the MGs.) + +MGs that are operating with the autonomous method must not rely solely on detection of the CNG tone, as this tone is only mandatory for automatic G3FEs and manual G3FEs conforming to the post-1993 version of [ITU-T T.30]. + +If CNG is not present, then the MGs shall transition to ITU-T T.38 on detection of the ITU-T V.21 preamble, which is sent by all G3FEs except ITU-T V.34 G3FEs. ITU-T V.34 facsimiles use ITU-T V.8 signals that will have to be detected by the MG in order to support the procedures in clause 10. The ITU-T T.38 protocol proceeds with an ITU-T T.38 ITU-T V.21 flags indicator packet. The emitting MG, on receipt of the ITU-T T.38 ITU-T V.21 flags indicator packet, shall transition to ITU-T T.38 if not already in ITU-T T.38 mode. + +Optionally, if mutually supported by the media gateways involved in the call (via SDP exchange or other means), a media gateway may choose to transmit the ITU-T V.21 preamble to the peer gateway over the packet network using IETF RFC 4733 events (i.e., method 3 stated in clause E.2.2.2.2.1). [IETF RFC 4733] has defined four dedicated events (37-40) for relaying FSK-encoded binary information per channel. When using this method, IETF RFC 4733 RTP packets shall be generated by grouping events as well as by using the redundancy mechanisms, as defined in [IETF RFC 4733]/[IETF RFC 2198]. + +Detection of the call function set to *facsimile* within the ITU-T V.8 signals CI/CM/JM shall also indicate transition to image/t38 mode and the procedures in clause 10. See also Annex F. + +Media gateways that support the ITU-T T.38 autonomous transitioning method should not determine to switch to facsimile based on detection of a CED tone. The CED tone is the same tone as the ANS tone (defined in ITU-T V.25). The latter tone is sent by some non-fax modems. + +Note that if ITU-T T.38 is not supported by one of the MGs, the MGs may decide to attempt the facsimile call over ITU-T G.711 only if ITU-T G.711 was received in audio media descriptor (using ITU-T G.711 in this case is beyond the scope of this annex). + +###### **E.2.2.2.2.3 FoIP to VoIP transition criteria** + +The MGs shall autonomously transition from fax (image/t38 connection) to a voice (audio/RTP connection) when the MG detects one of the following: + +- a) Detection of the ITU-T T.30 DCN message: Following detection of the ITU-T T.30 DCN message, the MG will transmit the corresponding ITU-T T.38 packet and subsequently transition to voice. Following receipt of ITU-T T.38/ITU-T T.30 DCN packet, the MG will play out the ITU-T T.30 DCN and subsequently transition to voice. +- b) Detection of bidirectional silence: It is recommended that an MG transition back to voice mode after detecting more than 7 s of bidirectional silence (this value was chosen in order to allow for the ITU-T T.30 T2 timer). +- c) Receipt from the MGC of an appropriate command modifying the call to audio. A ITU-T H.248 Modify, a SIP INVITE command in which only the audio descriptor is present or the appropriate messages as per clause D.5 of [ITU-T H.323] can do this. + +### **E.2.3 Event and signal indication** + +There are several events and signals that need to be transferred from the MG to the MGC and vice versa during the set-up of a fax call. These events are defined in ITU-T H.248 packages. The base packages are in Annex E of [ITU-T H.248.1]. Additional signals for fax are defined in [ITU-T H.248.2]. + +### **E.2.4 Capabilities negotiation** + +There are several options that need to be negotiated to determine which options the gateways support and use. These are described in Table B.1 and are defined as SDP extensions in clause D.2.3. They are also defined as binary types in the IP Fax package of ITU-T H.248.2. + +An ITU-T T.38 Annex E implementation may use the SDP extensions to describe the fax media terminations in text mode of the protocol. An ITU-T H.248.1 implementation shall use the IP fax package as the preferred method to describe the fax media termination. These media descriptors indicate the capabilities of, or requested of a media gateway (e.g., TCP, UDPTL or RTP transport). + +In addition, as well as being able to identify that a call is using ITU-T T.38 transport for facsimile, [ITU-T H.248.1] may also indicate other transports. + +### **E.2.5 Examples of call set-up** + +Examples of the ITU-T T.38 MGC procedure are described in clauses III.2.1 and III.2.2. + +Examples of the ITU-T T.38 autonomous transitioning method are described in clauses III.2.3 and III.2.4. + +### **E.2.6 Minimum call set-up messages** + +The implementation of this annex shall support the minimum requirements for [ITU-T H.248.1] as noted in clause 8.2 of [ITU-T H.248.1]. + +### **E.2.7 Mapping of call progress signals** + +For call set-up and call progress, the return signals are identical to those in Annex B (for ITU-T H.323 Fast Connect set-up) and Annex D (for SIP). + +### **E.2.8 DTMF transmission** + +[ITU-T H.248.1] supports collection of DTMF digits to make a call. + +DTMF tones transmission during an established voice and facsimile call is handled within the DTMF packages of clauses E.5 and E.6 of [ITU-T H.248.1]. + +### **E.2.9 Interoperability** + +Both [ITU-T H.248.1] and Annex B require a well-known port to initiate call signalling. ITU-T T.38 Annex E endpoints shall use the ITU-T H.248.1 well-known port of 2944 for the text protocol and 2945 for the binary protocol. + +# Annex F + +## Interworking procedures: ITU-T T.38 and ITU-T V.150.1 in the same gateway + +(This annex forms an integral part of this Recommendation.) + +## F.1 Introduction + +This annex describes the procedures that shall be used by gateways that have both ITU-T T.38 and ITU-T V.150.1 capabilities in the same gateway. Such a gateway shall indicate these capabilities by use of the appropriate external signalling mechanism (ITU-T H.323, ITU-T H.248 or SIP/SDP) as defined in the relevant Recommendations. The terms "FoIP" and "MoIP" as used in this annex are synonymous to ITU-T T.38 and ITU-T V.150.1 respectively. + +This type of gateway shall only transition to FoIP from MoIP. These procedures do not include any transitions directly from audio to FoIP nor do they replace the audio and ITU-T T.38 configuration procedures as defined in Annexes B, D and E. + +A gateway with these joint capabilities shall initially behave as an ITU-T V.150.1 gateway. That is all the call discrimination procedures up to the point at which ITU-T T.38 procedures are invoked are defined in clause 20 of [ITU-T V.150.1]. The transition from MoIP to FoIP occurs when a gateway (in MoIP mode) detects and verifies the presence of an ITU-T T.30 facsimile signal such as ITU-T V.21 Channel 2 HDLC encoded flags or an ITU-T V.8 CM signal on the telephony link to the gateway. + +This switching mechanism shall use state signalling event (SSE) protocol as defined in Annex C of [ITU-T V.150.1]. Figures F.1 and F.2 illustrate this transition for two facsimile triggering events. Figure F.1 shows a transition to Standard G3 facsimile, and Figure F.2 shows a similar transition to ITU-T V.34 facsimile. + +![Sequence diagram illustrating the transition from MoIP to ITU-T T.38 facsimile between two gateways (G1 and G2).](572cf014db14c8234f91c07d5a5a28c6_img.jpg) + +The diagram shows a sequence of events between four entities: F1, G1, G2, and F2. F1 and G1 are connected by 'Link 1', and G2 and F2 are connected by 'Link 2'. The central part of the diagram shows the interaction between G1 and G2. G1 has two vertical lifelines: 'Audio' and 'Facsimile/ITU-T T.38'. G2 has two vertical lifelines: 'Audio' and 'Facsimile/ITU-T T.38'. The sequence of events is as follows: 1. G1 sends 'Audio' to F1. 2. G1 sends 'Facsimile/ITU-T T.38' to F1. 3. G2 sends 'Audio' to F2. 4. G2 sends 'ITU-T V.21(H) flags' to G1. 5. G1 sends 'SSE: f(V21Flags)' to G2. 6. G2 sends 'SSE: f(p)' to G1. 7. G1 sends 'Facsimile/ITU-T T.38' to G2. 8. G2 sends 'Facsimile/ITU-T T.38' to F2. The diagram is labeled 'T.38(15)\_FF.1' at the bottom right. + +Sequence diagram illustrating the transition from MoIP to ITU-T T.38 facsimile between two gateways (G1 and G2). + +Figure F.1 – ITU-T T.38 FoIP (MoIP transition to ITU-T T.30 fax) + +![Figure F.2 – ITU-T T.38 FoIP (MoIP transition to ITU-T V.34 fax). The diagram shows a network topology with four nodes: F1, G1, G2, and F2. F1 and G1 are connected by 'Link 1'. G1 and G2 are connected by 'ITU-T T.38'. G2 and F2 are connected by 'Link 2'. F1 sends 'ITU-T V.8-CM = ITU-T V.4 fax' to G1. G1 sends 'Audio' to G2. G2 sends 'Audio' to F2. G1 sends 'SSE: f(V34fax)' to G2. G2 sends 'SSE: f(p\')' to G1. F1 sends 'Facsimile/ ITU-T T.38' to G1. G2 sends 'Facsimile/ ITU-T T.38' to F2. The diagram is labeled 'T.38(15)_FF.2' at the bottom right.](401f020d9ab5904f584424eabb596d2c_img.jpg) + +Figure F.2 – ITU-T T.38 FoIP (MoIP transition to ITU-T V.34 fax). The diagram shows a network topology with four nodes: F1, G1, G2, and F2. F1 and G1 are connected by 'Link 1'. G1 and G2 are connected by 'ITU-T T.38'. G2 and F2 are connected by 'Link 2'. F1 sends 'ITU-T V.8-CM = ITU-T V.4 fax' to G1. G1 sends 'Audio' to G2. G2 sends 'Audio' to F2. G1 sends 'SSE: f(V34fax)' to G2. G2 sends 'SSE: f(p\')' to G1. F1 sends 'Facsimile/ ITU-T T.38' to G1. G2 sends 'Facsimile/ ITU-T T.38' to F2. The diagram is labeled 'T.38(15)\_FF.2' at the bottom right. + +**Figure F.2 – ITU-T T.38 FoIP (MoIP transition to ITU-T V.34 fax)** + +Upon the detection of a facsimile event, the gateway shall transmit a SSE:f(RIC) to the peer gateway, where SSE:f is the FAX RELAY SSE transition indication. RICs are reason identifier codes and are defined in clause F.2. The use of SSE shall comply with Annex C of [ITU-T V.150.1]. + +[ITU-T V.150.1] defines the SSE:f event code in clause C.5.2 of [ITU-T V.150.1] and it has a decimal value of 4. + +## F.2 SSE reason identifier codes for ITU-T T.38 transition + +The following RICs are defined for the SSE:f event: + +**V21Flags:** This RIC indicates that the gateway has detected and verified that it has received HDLC flags modulated on ITU-T V.21 channel 2 as defined in [ITU-T T.30]. + +**V8Profile:** This RIC indicates that the gateway has received a ITU-T V.8 CM sequence that is a valid facsimile connection request. This RIC has as additional information – the Profile and ITU-T T.66 codes (if present) – that is used in the "t30-data(cm-message)" of this Recommendation. + +**P' State Transition:** This is the same signal as used in MoIP. It performs the same behaviour as an ACK. The value is chosen to be consistent with [ITU-T V.150.1]. + +The table below summarizes the RICs for ITU-T T.38 SSEs. + +| Name | Code (decimal) | Additional informational content | +|---------------------|----------------|----------------------------------| +| Null | 0 | None | +| V21Flags | 1 | None | +| V8Profile | 2 | "cm-message" | +| p' State Transition | 19 | None | + +In both examples, the use of SSE:f may be used as an equivalent signal from ITU-T T.38. For example SSE:f(V21Flags) may be used as t30-indicator:FLAGS and SSE:f(V8profile(cm-message)) may be used as t30-data:cm-message. + +A gateway is not required to wait for the SSE:f(p') message in response to its SSE:f request. The gateway shall transmit the equivalent ITU-T T.38 IFP message immediately after issuing the SSE:fr request. The gateway shall then follow the procedures as defined in this Recommendation. + +## F.3 Mode override from ITU-T V.34 Group 3 facsimile to standard Group 3 facsimile + +This annex describes a procedure by which ITU-T V.34 HDX-enabled terminals can be forced by media gateways to operate in standard Group 3 mode. The procedures can be used if both facsimile terminals are ITU-T V.34 G3FEs and if either or both of the connecting gateways do not support the ITU-T T.38/ITU-T V.34 procedures as defined in clause 10. + +Upon detection of an ITU-T V.8 CM signal the gateway should determine from the Call Function if the CM is being transmitted by the ITU-T V.34 capable facsimile terminal. If so verified the ingress gateway shall block the audio transmission and transmit silence. In order to prevent call failure, the gateway shall prevent transmission of more than a single CM sequence. + +Blocking the transmission of CM to the answering terminal will cause a timeout and standard ITU-T T.30 signals will be generated as a consequence (see Figures 6a and 6b of [ITU-T T.30]). The transition from MoIP to FoIP occurs when the gateway detects and verifies the presence of an ITU-T T.30 facsimile signal such as ITU-T V.21 flags on the telephony link to the gateway. To prevent any further attempts of the terminals to connect using ITU-T V.34, the ITU-T V.8 bit in the ITU-T T.30 DIS message relayed by the gateways should be set to 0. + +This switching mechanism shall use state signalling event (SSE) protocol as defined in Annex C of [ITU-T V.150.1] or payload type procedures as defined in clause 10 of [ITU-T V.152]. + +Figure F.3 shows a transition to Standard G3 facsimile using SSE switching procedures. + +![Sequence diagram showing the transition from ITU-T V.34 Group 3 facsimile to standard Group 3 facsimile using SSE switching procedures between two gateways (G1, G2) and two facsimile terminals (F1, F2).](f2486d5031b55e42b300903a716b0a00_img.jpg) + +The diagram illustrates the transition from ITU-T V.34 Group 3 facsimile to standard Group 3 facsimile using SSE switching procedures. It involves four entities: F1 (Facsimile Terminal 1), G1 (Gateway 1), G2 (Gateway 2), and F2 (Facsimile Terminal 2). + +**Initial State (Left):** + +- F1 sends "Audio" and "ITU-T V.8-CM = ITU-T V.34 fax" to G1. +- G1 sends "Facsimile/ITU-T T.38" to F1. +- Link 1 (between F1 and G1) has "DIS(v.8 bit = 0)". + +**Transition (Middle):** + +- G1 sends "G1 cut CM" to F1. +- G1 sends "SSE: f(V21Flags)" to G2. +- G1 sends "SSE: f(p)" to G2. +- G2 sends "ITU-T T.38" to G1. +- IFP: DIS hdlc-data is sent between G1 and G2. + +**Final State (Right):** + +- G2 sends "Audio" and "ITU-T V.21(H) flags" to F2. +- F2 sends "Facsimile/ITU-T T.38" to G2. +- Link 2 (between G2 and F2) has "DIS(v.8 bit = 1)". + +The diagram is labeled T.38(15)\_FF.3 in the bottom right corner. + +Sequence diagram showing the transition from ITU-T V.34 Group 3 facsimile to standard Group 3 facsimile using SSE switching procedures between two gateways (G1, G2) and two facsimile terminals (F1, F2). + +**Figure F.3 – ITU-T T.38 FoIP (MoIP fallback and transition to ITU-T T.30 fax by SSE)** + +Figure F.4 shows a transition to standard G3 facsimile using payload type switching procedures. + +![Sequence diagram showing ITU-T T.38 FoIP (MoIP fallback and transition to ITU-T T.30 fax by Payload) between F1, G1, G2, and F2.](7b7596fb5ef925025341a9aacb6f2be7_img.jpg) + +The diagram illustrates the signaling sequence for ITU-T T.38 FoIP, showing the transition from Voice mode to VBD mode and then to ITU-T T.38 mode. The participants are F1, G1, G2, and F2. + +**Participants:** + +- F1:** Contains CM1, CM2, CM3, and DCS. +- G1:** Contains Voice mode and VBD mode (or ITU-T G.711). +- G2:** Contains Voice mode and VBD mode (or ITU-T G.711). +- F2:** Contains /ANSam and ITU-T V.21 flags. + +**Sequence of Events:** + +- Voice mode:** F1 sends /ANSam to G1. G1 sends IP: /ANSam to G2. G2 sends /ANSam to F2. +- VBD mode (or ITU-T G.711):** F1 sends /ANSam to G1. G1 sends IP G.711: /ANSam to G2. G2 sends /ANSam to F2. +- Call function detects fax CM squelch VBD signal:** A call function detects a fax CM squelch VBD signal. +- ITU-T V.21 flags:** F1 sends ITU-T V.21 flags to G1. G1 sends IP G.711: v.21 flags to G2. G2 sends ITU-T V.21 flags to F2. +- ITU-T T.38 mode:** F1 sends ITU-T V.21 flags to G1. G1 sends T30 IND: Flags to G2. G2 sends ITU-T V.21 flags to F2. +- DIS (V.8bit=0):** F1 sends DIS (V.8bit=0) to G1. G1 sends V.21: HDLC: DIS/ FCS(reset V.8bit=0) to G2. G2 sends DIS to F2. +- DCS:** F1 sends DCS to G1. G1 sends T30 IND: Flags to G2. G2 sends ITU-T V.21 flags to F2. + +**Time out:** A time out occurs after the ITU-T V.21 flags are received by F2. + +**Annotations:** + +- A dashed arrow points from G1 to G2, indicating a transition or fallback. +- A box labeled "Call function detects fax CM squelch VBD signal" points to the transition from VBD mode to ITU-T T.38 mode. + +**Diagram Label:** T.38(15)\_FF.4 + +Sequence diagram showing ITU-T T.38 FoIP (MoIP fallback and transition to ITU-T T.30 fax by Payload) between F1, G1, G2, and F2. + +**Figure F.4 – ITU-T T.38 FoIP (MoIP fallback and transition to ITU-T T.30 fax by Payload)** + +## F.4 External signalling + +The use of SSEs is negotiated during the call set-up phase. Annexes E and F of [ITU-T V.150.1] describe the SDP and ITU-T H.323 syntax accordingly to be incorporated by a MoIP/FoIP gateway. + +NOTE – The definition of the ITU-T H.248 syntax for [ITU-T V.150.1] is to be defined. + +# Annex G + +## ITU-T H.245 capability definition for ITU-T T.38 over RTP + +(This annex forms an integral part of this Recommendation.) + +This annex defines a generic ITU-T H.245 capability that allows for the transport of ITU-T T.38 over RTP. It is intended that this capability would be signalled as an **audioCapability** within ITU-T H.245-based systems. + +Note that [ITU-T H.245] already defines an ITU-T T.38 capability for transport of IFP packets over UDP and TCP, which is a **dataApplicationCapability**. The capability definition in this annex is not intended to replace that definition, but rather to provide a means of transporting ITU-T T.38 IFP packets over RTP only. + +| | | +|------------------------------|--------------------------------------------------------------------------| +| Capability name: | T38RTP | +| Capability class: | Audio Capability | +| Capability identifier type: | Standard | +| Capability identifier value: | itu-t (0) recommendation (0) t (20) 38 h245-audio-capability(0) | +| maxBitRate: | This parameter is optional. | +| collapsing: | This field shall not be included and shall be ignored if received. | +| nonCollapsing: | This field shall be present and consist of the parameters defined below. | +| nonCollapsingRaw: | This field shall not be included and shall be ignored if received. | +| transport: | This field shall not be included. | + +Parameters for this capability are defined in the following tables: + +| | | +|-----------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Parameter name: | BooleanOptions | +| Parameter description: | This is a nonCollapsing capability.
Contains various Boolean options that must be conveyed. | +| Parameter identifier value: | 0 | +| Parameter status: | Mandatory | +| Parameter type: | BooleanArray
LSB is bit 0. Bit value 1 = TRUE.
Bit 0 – fillBitRemoval
Bit 1 – transcodingJBIG
Bit 2 – transcodingMMR
All other bits are reserved and shall be ignored. | +| Supersedes: | – | + +| | | +|-----------------------------|------------------------------------------------------------------------------------------------| +| Parameter name: | Version | +| Parameter description: | This is a nonCollapsing capability.
This identifies the version of the ITU-T T.38 protocol. | +| Parameter identifier value: | 1 | +| Parameter status: | Optional. If absent, version 0 is assumed. | +| Parameter type: | unsignedMin | +| Supersedes: | – | + +| | | +|-----------------------------|---------------------------------------------------------------------------------------------| +| Parameter name: | T38FaxRateManagement | +| Parameter description: | This is a nonCollapsing capability.
This specifies the fax rate management modes. | +| Parameter identifier value: | 2 | +| Parameter status: | Required. Only one sub-parameter of T38FaxRateManagement may be included in this parameter. | +| Parameter type: | genericParameter | +| Supersedes: | – | + +| | | +|-----------------------------|--------------------------------------------------------------------------------| +| Parameter name: | T38FaxRateManagement-localTCF | +| Parameter description: | This is a nonCollapsing capability that is an element of T38FaxRateManagement. | +| Parameter identifier value: | 0 | +| Parameter status: | Optional | +| Parameter type: | logical | +| Supersedes: | – | + +| | | +|-----------------------------|--------------------------------------------------------------------------------| +| Parameter name: | T38FaxRateManagement-transferredTCF | +| Parameter description: | This is a nonCollapsing capability that is an element of T38FaxRateManagement. | +| Parameter identifier value: | 1 | +| Parameter status: | Optional | +| Parameter type: | logical | +| Supersedes: | – | + +| | | +|-----------------------------|--------------------------------------------------------------------------------| +| Parameter name: | t38FaxMaxBuffer | +| Parameter description: | This is a nonCollapsing capability.
This specifies the maximum buffer size. | +| Parameter identifier value: | 3 | +| Parameter status: | Optional | +| Parameter type: | unsigned32Max | +| Supersedes: | – | + +| | | +|-----------------------------|----------------------------------------------------------------------------------| +| Parameter name: | t38FaxMaxDatagram | +| Parameter description: | This is a nonCollapsing capability.
This specifies the maximum datagram size. | +| Parameter identifier value: | 4 | +| Parameter status: | Optional | +| Parameter type: | unsigned32Max | +| Supersedes: | – | + +# Annex H + +## Signalled and provisioned ITU-T T.38 protocol parameters + +(This annex forms an integral part of this Recommendation.) + +## H.1 Introduction + +The call-individual configuration of ITU-T T.38 endpoints requires the negotiation for some ITU-T T.38 parameters. The purpose of this annex is to clarify the configuration of ITU-T T.38 endpoints and ITU-T V.152-to-ITU-T T.38 (ITU-T V.153) interworking functions, and the definition of default parameter values. + +Table H.1 provides a summary for all ITU-T T.38 parameters, independent for any ITU-T T.38 signalling protocol type and also independent of any ITU-T T.38 transport mode. The default values are bold faced. + +**Table H.1 – ITU-T T.38 Configurations (= ITU-T T.38 parameter/value settings; generic format, i.e., signalling protocol independent and ITU-T T.38 transport unconditional)** + +| No. | Parameter | Value | +|-----|------------------------------|-------------------------------------------------------------------------------| +| 0 | T38 Transport Mode | UDPTL/UDP RTP/UDP TPKT/TCP | +| 1 | T38FaxVersion | 0 1 2 3 4 | +| 2 | T38MaxBitRate | 9600 14400 33600 | +| 3 | T38FaxFillBitRemoval | FALSE TRUE | +| 4 | T38FaxTranscodingMMR | FALSE TRUE | +| 5 | T38FaxTranscodingJBIG | FALSE TRUE | +| 6 | T38FaxRateManagement | localTCF transferredTCF | +| 7 | T38FaxMaxBuffer | ... 1800 ... | +| 8 | T38FaxMaxDatagram | ... 150 ... | +| 9 | T38FaxMaxIFP | ... 40 ... | +| 10 | T38FaxUdpEC | t38UDPFEC t38UDPRedundancy t38UDPNoEC | +| 11 | T38FaxUdpECDepth | minred :... 1 ...
maxred :... none ... | +| 12 | T38FaxUdpFECMaxSpan | ... 3 ... | +| 13 | T38VendorInfo | \$ ... \$ parameter omitted | +| 14 | T38ModemType | t38G3FaxOnly t38G3AndV34G3 | + +## H.2 Transport conditional ITU-T T.38 parameters + +### H.2.1 Transport mode for ITU-T T.38 IFP Packets + +Some ITU-T T.38 parameters are dependent on the applied transport mode (UDPTL/UDP vs RTP/UDP vs TPKT/TCP). The question of mandatory versus optional ITU-T T.38 parameters may be therefore considered under the condition of the mutually agreed ITU-T T.38 transport. + +The ITU-T T.38 transport is negotiated in SDP via the "c=" line (IP version) and "m=" line (field 'proto'). + +### **H.2.2 Overview of transport-dependent ITU-T T.38 parameters** + +#### **H.2.2.1 Transport mode "UDPTL/UDP"** + +Table H.2 provides a summary of all the defined ITU-T T.38 parameters. It may be concluded that **all** parameters may be principally optional, and may thus be omitted in control plane signalling protocols. In the case of absent parameters in signalling messages, the local ITU-T T.38 endpoint will apply the default parameter values. The default parameter values may be further refined in an "ITU-T T.38 profile" definition (which may be, for example, a subset of a SIP or ITU-T H.248 interface profile), if not already implicitly given by ITU-T T.38 itself. + +**Table H.2 – ITU-T T.38 SDP parameter (Semantics according to SDP IETF RFC 3264 capability negotiation protocol) – +(1) Negotiated IP transport = UDPTL/UDP** + +| No. | Name | Syntax (SDP) | Semantic (SIP/SDP)
Ref.: Clause D.2.3.5 | Mandatory/
Optional? | Type and unit | (Provisioned)
Default value | +|-----|-----------------------------|------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------|---------------------------------------------------|--------------------------------| +| 1 | Version | T38FaxVersion | Parameter is negotiated. The entity answering the offer shall return the same or a lower version number. | Recommended (Note 8). If omitted then default value. | INTEGER (0..255), [-] | 0 | +| 2 | Maximum Bitrate | T38MaxBitRate | Parameter is declarative and the answer is independent of the offer. The parameter simply indicates the maximum transmission bit rate supported by the endpoint. | Recommended (Note 9). If omitted then default value. | INTEGER (0..2 16 -1), [bit/s] (Note 6) | 14 400 (Note 1) | +| 3 | Fill Bit Removal | T38FaxFillBitRemoval | Parameter is negotiated. If the answering entity does not support this capability or if the capability was not in the offer, this parameter shall not be present in the answer. | Optional. If omitted then default value. | BOOLEAN, [-] | FALSE | +| 4 | MMR Transcoding | T38FaxTranscodingMMR | Parameter is negotiated. If the answering entity does not support this capability or if the capability was not in the offer, this parameter shall not be present in the answer. | Optional. If omitted then default value. | BOOLEAN, [-] | FALSE | +| 5 | JBIG Transcoding | T38FaxTranscodingJBIG | Parameter is negotiated. If the answering entity does not support this capability or if the capability was not in the offer, this parameter shall not be present in the answer. | Optional. If omitted then default value. | BOOLEAN, [-] | FALSE | +| 6 | Data Rate Management Method | T38FaxRateManagement | Parameter is declarative and the answer must contain the same value. | Mandatory. If omitted then default value. | ENUMERATION, [-] | 'transferredTCF' (Note 4) | +| 7 | Maximum Buffer Size | T38FaxMaxBuffer | Parameter is declarative and the answer is independent of the offer. This parameter simply signals the buffer space available on the offering endpoint and the answering endpoint. The answering endpoint may have more or less buffer space than the offering endpoint. Each endpoint should be considerate of the available buffer space on the opposite endpoint. | Optional. If omitted then default value. | INTEGER (0..2 16 -1), [bytes] | 1800 (Note 2) | + +**Table H.2 – ITU-T T.38 SDP parameter (Semantics according to SDP IETF RFC 3264 capability negotiation protocol) – +(1) Negotiated IP transport = UDPTL/UDP** + +| No. | Name | Syntax (SDP) | Semantic (SIP/SDP)
Ref.: Clause D.2.3.5 | Mandatory/
Optional? | Type and unit | (Provisioned)
Default value | +|-----|--------------------------|--------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------|--------------------------------| +| 8 | Maximum
Datagram Size | T38FaxMaxDatagram | Parameter is declarative and the answer is independent of the offer. This parameter signals the largest acceptable datagram for the offering endpoint and the answering endpoint (i.e., the maximum size of the xyz payload). The answering endpoint may accept a larger or smaller datagram than the offering endpoint. Each endpoint should be considerate of the maximum datagram size of the opposite endpoint. | Optional. If omitted then default value. | INTEGER (0..2 16 -1), [bytes] | 150
(Note 3) | +| 9 | Maximum IFP
Size | T38FaxMaxIFP | Parameter is declarative and the answer is independent of the offer. This parameter signals the maximum IFP frame size the offering endpoint is capable of accepting. | Optional. If omitted then default value. . If T38FaxMaxIFP is included in an offer, then inclusion of this parameter is Mandatory in that offer. | INTEGER (0..2 16 -1), [bytes] | 40
(Note 3)
(Note 7) | +| 10 | Error
Correction | T38FaxUdpEC | Parameter is negotiated only when using UDPTL as the transport. If the answering endpoint supports the offered error correction mode, then it shall return the same value in the answer; otherwise, the T38FaxUdpEC parameter shall not be present in the answer. | Optional. If omitted then default value. | ENUMERATION, [-] | 't38UDPRedundancy'
(Note 5) | + +**Table H.2 – ITU-T T.38 SDP parameter (Semantics according to SDP IETF RFC 3264 capability negotiation protocol) – +(1) Negotiated IP transport = UDPTL/UDP** + +| No. | Name | Syntax (SDP) | Semantic (SIP/SDP)
Ref.: Clause D.2.3.5 | Mandatory/
Optional? | Type and unit | (Provisioned)
Default value | +|-----|------------------------------|----------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------|--------------------------------------------------------|--------------------------------------------------| +| 11 | Error
Correction
Depth | T38FaxUdpECDepth | Parameter is declarative and the answer is independent of the offer, and is relevant only when using UDPTL as the transport. If the parameter is specified, then the 'minred' value indicates that the offering endpoint wishes to receive at least that many redundancy frames per UDPTL datagram (when the answering endpoint chooses to use t38UDPRedundancy as the error correction mode), or that the offering endpoint wishes to receive at least that many FEC frames per UDPTL datagram (when the answering endpoint chooses to use t38UDPFEC as the error correction mode). Additionally, if 'maxred' is specified, it indicates that the offering endpoint wishes to receive no more than that many redundancy frames or FEC frames per UDPTL datagram. | Optional. If omitted then default value. | INTEGER (0..2 16 –1),
[frames] | 1 for 'minred',
none for 'maxred'
(Note 3) | +| 12 | Error
Correction
Span | T38FaxUdpFECMaxSpan | Parameter is declarative and the answer is independent of the offer, and is relevant only when using UDPTL as the transport. If the parameter is specified, it indicates that offering endpoint may not be able to properly process FEC frames that span more than the specified number of IFP frames. | Optional. If omitted then default value. | INTEGER (0..2 16 –1),
[frames] | 3 | +| 13 | Vendor
Information | T38VendorInfo | Parameter is declarative and the answer is independent of the offer. The parameter merely indicates the manufacturer of the endpoint. | Optional.. | Space separated List
of three INTEGERS
(Note 10) | No default value
configured | + +**Table H.2 – ITU-T T.38 SDP parameter (Semantics according to SDP IETF RFC 3264 capability negotiation protocol) – +(1) Negotiated IP transport = UDPTL/UDP** + +| No. | Name | Syntax (SDP) | Semantic (SIP/SDP)
Ref.: Clause D.2.3.5 | Mandatory/
Optional? | Type and unit | (Provisioned)
Default value | +|-----|-----------------|---------------------|---------------------------------------------------------------------------------------|---------------------------------------------|---------------|--------------------------------| +| 14 | Supported Modem | T38ModemType | Parameter is declarative and indicates the modem capability supported by the gateway. | Optional. If omitted then default value (0) | Enumeration | t38G3FaxOnly | + +NOTE 1 – The bitrate of the ITU-T V.17 modem is used as default value due to the majority of deployed G3FE devices, which are supporting ITU-T V.17 modem speed. + +NOTE 2 – The proposed default maximum buffer size relates to a conservative estimate of ITU-T V.17 modem data for one second (= 1800 bytes due to 14400 bit/s times one second). + +NOTE 3 – The maximum datagram size (which is the maximum size of the UDPTL PDU) is a result of the packetization time, the maximum bitrate (modem speed) and the redundancy level (andFEC). The proposed default value of 150 bytes represents a conservative estimate under the conditions of fastest modem speed, a maximum redundancy level of '3', and packetization time of 20 ms. Dependency between T38FaxMaxDatagram, T38FaxMaxIFP and T38FaxUdpECDepth can be defined as: + +$$T38FaxMaxDatagram \geq UDPTL\ header + T38FaxMaxIFP + T38FaxUdpECDepth * (\text{number of bytes per FEC or number of bytes per redundant frame}) + \text{additional bytes for error recovery due to ASN.1 structure.}$$ + +NOTE 4 – Because data rate management method 2 is mandatory for UDP (see clause 8.2). + +NOTE 5 – Because the packet redundancy method is simpler and more widely deployed as forward error correction methods. + +NOTE 6 – The interpretation of the unit value of **T38MaxBitRate** parameter is specific to a given protocol. + +NOTE 7 – The default value was calculated similarly to that of T38FaxMaxDatagram (in Note 3 of this table). + +NOTE 8 – The main ITU-T T.38 capability set are related to a particular ITU-T T.38 version. It is therefore recommended to signal this parameter. + +NOTE 9 – This parameter is recommended to be signalled in order to avoid potential interoperability problems (see clause B.3.7 which mandates this parameter for ITU-T H.323-controlled ITU-T T.38 endpoints). + +NOTE 10 – See clauses D.2.3.1 and D.2.3.2. + +#### H.2.2.2 Transport mode "TPKT/TCP" + +For further study. + +#### H.2.2.3 Transport mode "RTP/UDP" + +For further study. + +## H.3 Guidelines for signalling ITU-T T.38 protocol parameters + +A default ITU-T T.38 configuration could be provisioned in *all* ITU-T T.38 entities of a particular ITU-T T.38 domain, which would allow omitting the indication, signalling and negotiation of all ITU-T T.38 configuration details between ITU-T T.38 on-ramp and off-ramp gateways or IAFs. + +However, the complete provisioning approach is not recommended, primarily due to: + +- Default values for ITU-T T.38 parameters were not entirely specified for ITU-T T.38 versions 0 to 3, thus a potential source of ambiguity. +- It may be not excluded that different ITU-T T.38 versions could use different default value settings. +- Spatial horizon of a single ITU-T T.38 domain may span multiple IP network domains (e.g., ITU-T T.38 endpoints located in different provider domains, and each provider has its own preferred ITU-T T.38 default configuration settings). + +It is therefore recommended to signal *entire* ITU-T T.38 configuration settings. For instance: + +- Just signalling the *mandatory* ITU-T T.38 parameters is considered to be insufficient due to the ITU-T T.38 version-dependent capability sets. +- Or just signalling the ITU-T T.38 *version number* (via parameter *T38FaxVersion*) in order to refer a particular ITU-T T.38 capability set is considered to be insufficient due to the optional nature of this parameter in previous ITU-T T.38 versions. + +## H.4 Legacy Interpretation of SDP Parameters + +### H.4.1 T38MaxBitRate + +Prior to the 2010 version of this Recommendation, the resolution of the T38MaxBitRate parameter was not defined. Consequently, many implementations have used different values for this resolution. While this oversight has now been corrected, there will still be potential interoperability issues between implementations. Since SDP changes are not managed by the ASN.1 syntax version number, the intent of this clause is to provide some guidance on how to manage these differences. + +The values used in the parameter represent the various maximum Group 3 bit rates supported by an implementation, consequently they will indicate the set of rates of {33600, 31200, 28800, 26400, 24000, 21600, 19200, 14400, 12000, 9600, 7200, 4800, 2400} depending upon the modulations supported. Implementers have represented these values in the T38MaxBitRate using resolution of 100 bit/s or 1 bit/s. + +If on receiving the parameter it has a value stated in the set above, it can be assumed that the resolution is 1 bit/s. If, however, the value is in the set of {336, 312, 288, 264, 240, 216, 192, 144, 120, 96, 72, 48, 24}, then the assumed resolution is 100 bit/s. + +Note according to most implementers, only 100 and 1 bit/s resolutions have been used in the field. + +# Appendix I + +## Session examples + +(This appendix does not form an integral part of this Recommendation.) + +## I.1 Session examples + +This appendix contains a number of examples to show how the sending and receiving G3FEs communicate with the gateways and what packets the gateways exchange. All examples show a TCP implementation using Method 1 rate adaptation. + +Time proceeds downward. Information flows on the solid lines in the direction of the arrows. The box superimposed on each line indicates what information is being transmitted. All information between the G3FE and a gateway is ITU-T T.30/T.4/T.6-conforming information. Information transmitted between the gateways is in the form of packets as described in this Recommendation. The contents of the labelling box on a packet transmission indicates the packet type, followed by any additional information which is carried in the packet's payload. + +Dashed lines are used to clarify the point in time at which a piece of information begins transmission (for example, T30\_INDICATOR: Flags packets are sent when flags are noticed, not necessarily when the flags begin or end transmission). Dashed lines do not indicate any type of information flow. + +Packet labels indicate the type of packet as well as any field information, for field-type packets. For example, a label such as "ITU-T V.21:HDLC:TSI/FCS" indicates an ITU-T V.21 HDLC (ITU-T T.30 Control) packet with a field containing TSI information and a field indicating FCS. Due to space constraints, the FCS is generalized to include FCS and FCS-Sig-End. + +### I.1.1 Two traditional facsimile devices communicating using ECM + +Figure I.1 shows two traditional Group 3 facsimile devices that use the PSTN for communicating with facsimile gateways. ECM is used for image transfer. The example begins after the transport connection/session has been established and the receiving G3FE has answered a call from the receiving gateway and is about to generate CED. + +### I.1.2 Traditional facsimile device and Internet-aware facsimile device + +Figure I.2 shows a traditional Group 3 facsimile device sending to an Internet-aware facsimile device without using ECM. The example begins after the transport connection/session has been established and the Receiving is about to generate CED. + +### I.1.3 Two traditional facsimile devices using frequent frames + +Figure I.3 shows two traditional Group 3 facsimile devices that use the PSTN for communicating with facsimile gateways. It is similar to the scenario described in clause I.1.1, except that the image transfer does not use ECM and the receiving gateway does not wait for complete HDLC BCS sequences before beginning to send frames. + +![Sequence diagram showing the communication flow between four entities: Sending G3FE, Emitting gateway, Receiving gateway, and Receiving G3FE. The diagram illustrates the transmission of various facsimile data elements including CED tone, Flags, CSI, DIS, TSI, DCS, TCF, CFR, Training, Image data, PPS-NULL, and PPR through multiple T30 and V.21/V.17 HDLC protocol layers.](9687bd5e8b62cadba093b0d1b70536cd_img.jpg) + +The diagram illustrates the communication flow between four entities: Sending G3FE, Emitting gateway, Receiving gateway, and Receiving G3FE. The flow is as follows: + +- Initial Setup:** + - Receiving G3FE** sends **CED tone** to **Receiving gateway**. + - Receiving gateway** sends **T30 IND: CED** to **Emitting gateway**. + - Emitting gateway** sends **CED tone** to **Sending G3FE**. +- First Data Transfer:** + - Receiving G3FE** sends **Flags**, **CSI**, and **DIS** to **Receiving gateway**. + - Receiving gateway** sends **T30 IND: Flags** to **Emitting gateway**. + - Emitting gateway** sends **Flags**, **TSI**, and **DCS** to **Sending G3FE**. + - Emitting gateway** sends **V.21:HDLC:CSI/FCS** and **V.21:HDLC:DIS/FCS** to **Receiving gateway**. +- Second Data Transfer:** + - Sending G3FE** sends **TSI** and **DCS** to **Emitting gateway**. + - Emitting gateway** sends **V.21:HDLC:TSI/FCS** and **V.21:HDLC:DCS/FCS** to **Receiving gateway**. + - Receiving gateway** sends **Flags**, **TSI**, and **DCS** to **Receiving G3FE**. +- Third Data Transfer:** + - Sending G3FE** sends **TCF** to **Emitting gateway**. + - Emitting gateway** sends **TCF** to **Receiving gateway**. + - Receiving gateway** sends **TCF** to **Receiving G3FE**. +- Fourth Data Transfer:** + - Receiving G3FE** sends **Flags** and **CFR** to **Receiving gateway**. + - Receiving gateway** sends **T30 IND: Flags** to **Emitting gateway**. + - Emitting gateway** sends **Flags** and **CFR** to **Sending G3FE**. + - Emitting gateway** sends **V.21:HDLC:CFR/FCS** to **Receiving gateway**. +- Fifth Data Transfer:** + - Sending G3FE** sends **Training** and **Image data** to **Emitting gateway**. + - Emitting gateway** sends **T30 IND: Speed** to **Receiving gateway**. + - Receiving gateway** sends **Training** and **Image data** to **Receiving G3FE**. + - Emitting gateway** sends **V.17:HDLC: Image data** and **V.17:HDLC: Image data: FCS-Sig-End** to **Receiving gateway**. +- Sixth Data Transfer:** + - Receiving G3FE** sends **Flags** and **PPS-NULL** to **Receiving gateway**. + - Receiving gateway** sends **T30 IND: Flags** to **Emitting gateway**. + - Emitting gateway** sends **Flags** and **PPS-NULL** to **Sending G3FE**. + - Emitting gateway** sends **T.21:HDLC: PPS/NULL/FCS** to **Receiving gateway**. +- Seventh Data Transfer:** + - Sending G3FE** sends **PPS-NULL** to **Emitting gateway**. + - Emitting gateway** sends **T.21:HDLC: PPS/NULL/FCS** to **Receiving gateway**. + - Receiving gateway** sends **Flags** and **PPS-NULL** to **Receiving G3FE**. +- Eighth Data Transfer:** + - Receiving G3FE** sends **Flags** and **PPR** to **Receiving gateway**. + - Receiving gateway** sends **T30 IND: Flags** to **Emitting gateway**. + - Emitting gateway** sends **Flags** and **PPR** to **Sending G3FE**. + - Emitting gateway** sends **V.21:HDLC:PPR/FCS** to **Receiving gateway**. + +Sequence diagram showing the communication flow between four entities: Sending G3FE, Emitting gateway, Receiving gateway, and Receiving G3FE. The diagram illustrates the transmission of various facsimile data elements including CED tone, Flags, CSI, DIS, TSI, DCS, TCF, CFR, Training, Image data, PPS-NULL, and PPR through multiple T30 and V.21/V.17 HDLC protocol layers. + +T.38(15)\_Fl.1a + +Figure I.1 – Two Group 3 facsimile devices communicating through gateways (sheet 1 of 2) + +![Sequence diagram showing the communication between two Group 3 facsimile devices (Sending G3FE and Receiving G3FE) through two gateways (Emitting gateway and Receiving gateway). The diagram illustrates the flow of data and control signals across four vertical lanes, detailing the processing of training, image data, flags, and control signals like PPS, MCF, and DCN.](301f4a188198a15b1415d54545b07e0d_img.jpg) + +The diagram illustrates the communication flow between two Group 3 facsimile devices (Sending G3FE and Receiving G3FE) through two gateways (Emitting gateway and Receiving gateway). The diagram is organized into four vertical lanes representing the entities: Sending G3FE, Emitting gateway, Receiving gateway, and Receiving G3FE. + +**Sequence of Events:** + +- First Image Transfer:** + - Sending G3FE** sends **Training** and **Image data** to the **Emitting gateway**. + - Emitting gateway** processes these into **T30 IND : Speed** and **V.17:HDLC: Image data**, which are then sent to the **Receiving gateway**. + - Receiving gateway** sends **Training** and **Image data** to the **Receiving G3FE**. + - Sending G3FE** sends **Flags** and **PPS-NULL** to the **Emitting gateway**. + - Emitting gateway** processes these into **T30 IND : Flags** and **V.21:HDLC: PPS-NULL/FCS**, which are then sent to the **Receiving gateway**. + - Receiving gateway** sends **Flags** and **PPS-NULL** to the **Receiving G3FE**. +- Second Image Transfer:** + - Receiving G3FE** sends **Flags** and **MCF** back to the **Receiving gateway**. + - Receiving gateway** processes these into **T30 IND : Flags** and **V.21:HDLC:MCF/FCS**, which are then sent to the **Emitting gateway**. + - Emitting gateway** sends **Flags** and **MCF** back to the **Sending G3FE**. + - Sending G3FE** sends **Training** and **Image data** to the **Emitting gateway**. + - Emitting gateway** processes these into **T30 IND : Speed** and **V.17:HDLC: Image data:FCS**, which are then sent to the **Receiving gateway**. + - Receiving gateway** sends **Training** and **Image data** to the **Receiving G3FE**. + - Sending G3FE** sends **Flags** and **PPS-EOP** to the **Emitting gateway**. + - Emitting gateway** processes these into **T30 IND : Flags** and **V.21:HDLC: PPS-EOP/FCS**, which are then sent to the **Receiving gateway**. + - Receiving gateway** sends **Flags** and **PPS-EOP** to the **Receiving G3FE**. +- Third Image Transfer:** + - Receiving G3FE** sends **Flags** and **MCF** back to the **Receiving gateway**. + - Receiving gateway** processes these into **T30 IND : Flags** and **V.21:HDLC:MCF/FCS**, which are then sent to the **Emitting gateway**. + - Emitting gateway** sends **Flags** and **MCF** back to the **Sending G3FE**. + - Sending G3FE** sends **Flags** and **DCN** to the **Emitting gateway**. + - Emitting gateway** processes these into **T30 IND : Flags** and **V.21:HDLC:DCN/FCS**, which are then sent to the **Receiving gateway**. + - Receiving gateway** sends **Flags** and **DCN** to the **Receiving G3FE**. + - Receiving gateway** sends **DISCONNECT** to the **Emitting gateway**. + +Sequence diagram showing the communication between two Group 3 facsimile devices (Sending G3FE and Receiving G3FE) through two gateways (Emitting gateway and Receiving gateway). The diagram illustrates the flow of data and control signals across four vertical lanes, detailing the processing of training, image data, flags, and control signals like PPS, MCF, and DCN. + +T.38(15)\_Fl.1b + +Figure I.1 – Two Group 3 facsimile devices communicating through gateways (sheet 2 of 2) + +![Sequence diagram showing the interaction between a Sending G3FE, an Emitting gateway, and a Receiving gateway/Internet-aware device. The diagram illustrates the flow of various facsimile data elements and control signals across three vertical lifelines.](b8d855a06aad434aeafa2739bf62e7de_img.jpg) + +``` + +sequenceDiagram + participant S as Sending G3FE + participant E as Emitting gateway + participant R as Receiving gateway/Internet-aware device + + S->>E: CED tone + E->>R: T30 IND: CED + R->>E: T30 IND: CED + E->>S: CED tone + + S->>E: Flags + E->>R: T30 IND: Flags + R->>E: T30 IND: Flags + E->>S: Flags + + S->>E: CSI + E->>R: V.21: HDLC: CSI/FCS, DIS/FCS-Sig-End + R->>E: V.21: HDLC: CSI/FCS, DIS/FCS-Sig-End + E->>S: CSI + + S->>E: DIS + E->>R: T30 IND: Flags + R->>E: T30 IND: Flags + E->>S: DIS + + S->>E: Flags + E->>R: T30 IND: Flags + R->>E: T30 IND: Flags + E->>S: Flags + + S->>E: TSI + E->>R: V.21: HDLC: TSI/FCS + R->>E: V.21: HDLC: TSI/FCS + E->>S: TSI + + S->>E: DCS + E->>R: V.21: HDLC: DCS/FCS + R->>E: V.21: HDLC: DCS/FCS + E->>S: DCS + + S->>E: TCF + E->>R: T30 IND: Flags + R->>E: T30 IND: Flags + E->>S: TCF + + S->>E: Flags + E->>R: T30 IND: Flags + R->>E: T30 IND: Flags + E->>S: Flags + + S->>E: CFR + E->>R: V.21: HDLC: CFR/FCS + R->>E: V.21: HDLC: CFR/FCS + E->>S: CFR + + S->>E: Training + E->>R: T30 IND: Speed + R->>E: T30 IND: Speed + E->>S: Training + + S->>E: Image data + E->>R: V.17: non-ECM: Image data + R->>E: V.17: non-ECM: Image data + E->>S: Image data + + S->>E: Flags + E->>R: V.17: non-ECM: Image data: non-ECM-Sig-End + R->>E: V.17: non-ECM: Image data: non-ECM-Sig-End + E->>S: Flags + + S->>E: EOP + E->>R: T30 IND: Flags + R->>E: T30 IND: Flags + E->>S: EOP + + S->>E: Flags + E->>R: V.21: HDLC: EOP/FCS + R->>E: V.21: HDLC: EOP/FCS + E->>S: Flags + + S->>E: MCF + E->>R: T30 IND: Flags + R->>E: T30 IND: Flags + E->>S: MCF + + S->>E: Flags + E->>R: V.21: HDLC: MCF/FCS + R->>E: V.21: HDLC: MCF/FCS + E->>S: Flags + + S->>E: DCN + E->>R: T30 IND: Flags + R->>E: T30 IND: Flags + E->>S: DCN + + S->>E: DISCONNECT + E->>R: V.21: HDLC: DCN/FCS + R->>E: V.21: HDLC: DCN/FCS + E->>S: DISCONNECT + +``` + +The diagram illustrates the sequence of events and data exchanges between three entities: Sending G3FE, Emitting gateway, and Receiving gateway/Internet-aware device. The interactions are as follows: + +- Initial Setup:** The Sending G3FE sends a CED tone to the Emitting gateway, which then sends T30 IND: CED to the Receiving gateway. The Receiving gateway sends T30 IND: CED back to the Emitting gateway, which then sends the CED tone back to the Sending G3FE. +- Flags and CSI:** The Sending G3FE sends Flags and CSI to the Emitting gateway. The Emitting gateway sends T30 IND: Flags and V.21: HDLC: CSI/FCS, DIS/FCS-Sig-End to the Receiving gateway. The Receiving gateway sends T30 IND: Flags and V.21: HDLC: CSI/FCS, DIS/FCS-Sig-End back to the Emitting gateway, which then sends Flags and CSI back to the Sending G3FE. +- DIS and TCF:** The Sending G3FE sends DIS and TCF to the Emitting gateway. The Emitting gateway sends T30 IND: Flags and V.21: HDLC: TSI/FCS, DCS/FCS to the Receiving gateway. The Receiving gateway sends T30 IND: Flags and V.21: HDLC: TSI/FCS, DCS/FCS back to the Emitting gateway, which then sends DIS and TCF back to the Sending G3FE. +- Training and Image data:** The Sending G3FE sends Training and Image data to the Emitting gateway. The Emitting gateway sends T30 IND: Speed and V.17: non-ECM: Image data to the Receiving gateway. The Receiving gateway sends T30 IND: Speed and V.17: non-ECM: Image data: non-ECM-Sig-End back to the Emitting gateway, which then sends Training and Image data back to the Sending G3FE. +- EOP and MCF:** The Sending G3FE sends EOP and MCF to the Emitting gateway. The Emitting gateway sends T30 IND: Flags and V.21: HDLC: EOP/FCS, MCF/FCS to the Receiving gateway. The Receiving gateway sends T30 IND: Flags and V.21: HDLC: EOP/FCS, MCF/FCS back to the Emitting gateway, which then sends EOP and MCF back to the Sending G3FE. +- DCN and DISCONNECT:** The Sending G3FE sends DCN and DISCONNECT to the Emitting gateway. The Emitting gateway sends T30 IND: Flags and V.21: HDLC: DCN/FCS to the Receiving gateway. The Receiving gateway sends T30 IND: Flags and V.21: HDLC: DCN/FCS back to the Emitting gateway, which then sends DCN and DISCONNECT back to the Sending G3FE. + +Sequence diagram showing the interaction between a Sending G3FE, an Emitting gateway, and a Receiving gateway/Internet-aware device. The diagram illustrates the flow of various facsimile data elements and control signals across three vertical lifelines. + +T.38(15)\_FI.2 + +Figure I.2 – Traditional facsimile device and Internet-aware device + +![Sequence diagram showing the use of multiple frames per BCS sequence between four entities: Sending G3FE, Emitting gateway, Receiving gateway, and Receiving G3FE. The diagram illustrates the flow of various frames including CED tone, Flags, CSI, DIS, TSI, DCS, TCF, CFR, Training, Image data, EOP, and MCF, along with their corresponding HDLC and T30 IND frames.](c93c4b33a2b42c8dd6d82a354f2f89f1_img.jpg) + +The diagram illustrates the sequence of frames and their corresponding HDLC/T30 IND frames across four entities: Sending G3FE, Emitting gateway, Receiving gateway, and Receiving G3FE. + +- Sequence 1:** + - Sending G3FE sends CED tone, Flags, CSI, and DIS to Emitting gateway. + - Emitting gateway sends T30 IND: CED, T30 IND : Flags, V.21:HDLC:CSI, V.21:HDLC:CSI/FCS, V.21:HDLC:DIS, and V.21:HDLC:DIS/FCS to Receiving gateway. + - Receiving gateway sends CED tone, Flags, CSI, and DIS to Receiving G3FE. +- Sequence 2:** + - Sending G3FE sends Flags, TSI, DCS, and TCF to Emitting gateway. + - Emitting gateway sends T30 IND : Flags, V.21:HDLC:TSI/FCS, and V.21:HDLC:DCS/FCS to Receiving gateway. + - Receiving gateway sends Flags, TSI, DCS, and TCF to Receiving G3FE. +- Sequence 3:** + - Sending G3FE sends Flags and CFR to Emitting gateway. + - Emitting gateway sends T30 IND : Flags, V.21:HDLC:CFR, and V.21:HDLC:CFR/FCS to Receiving gateway. + - Receiving gateway sends Flags and CFR to Receiving G3FE. +- Sequence 4:** + - Sending G3FE sends Training and Image data to Emitting gateway. + - Emitting gateway sends T30 IND : Speed, V.17: non-ECM: Image data, and V.17: non-ECM: Image data: Sig-End to Receiving gateway. + - Receiving gateway sends Training and Image data to Receiving G3FE. +- Sequence 5:** + - Sending G3FE sends Flags and EOP to Emitting gateway. + - Emitting gateway sends T30 IND : Flags and V.21:HDLC:EOP/FCS to Receiving gateway. + - Receiving gateway sends Flags and EOP to Receiving G3FE. +- Sequence 6:** + - Sending G3FE sends Flags and MCF to Emitting gateway. + - Emitting gateway sends T30 IND : Flags, V.21:HDLC:MCF, and V.21:HDLC:MCF/FCS to Receiving gateway. + - Receiving gateway sends Flags and MCF to Receiving G3FE. + +Sequence diagram showing the use of multiple frames per BCS sequence between four entities: Sending G3FE, Emitting gateway, Receiving gateway, and Receiving G3FE. The diagram illustrates the flow of various frames including CED tone, Flags, CSI, DIS, TSI, DCS, TCF, CFR, Training, Image data, EOP, and MCF, along with their corresponding HDLC and T30 IND frames. + +T.38(15)\_Fl.3 + +**Figure I.3 – Use of multiple frames per BCS sequence** + +## I.2 IAF device + +This clause addresses the sequences that are considered in IAF device communication. + +### I.2.1 Sender is an IAF device, receiver is G3fax + +#### *CFR signal receive timing at the IAF device* + +It is recommended that IAF devices wait to receive the CFR signal, taking into account the period during which the Gateway sends TCF to G3fax. As Figure I.4 shows, this prevents the DCS signal of the IAF device from colliding at the gateway with the CFR signal of the G3fax. + +![Sequence diagram showing signal timing between IAF, Gateway, and G3fax.](a5404b7275b06497eecf9b5883604753_img.jpg) + +The diagram illustrates the timing of signals between three entities: IAF, Gateway, and G3fax. The IAF entity sends a DIS signal to the Gateway, which then forwards it to the G3fax entity. The G3fax entity sends a DCS signal to the Gateway, which then forwards it to the IAF entity. The Gateway sends a TCF signal to the G3fax entity. The G3fax entity sends a CFR signal to the Gateway, which then forwards it to the IAF entity. A bracket on the IAF side indicates that the IAF device waits to receive the CFR signal until after the Gateway has received the TCF signal from the G3fax device. The diagram is labeled T.38\_FI.4(APPI) in the bottom right corner. + +Sequence diagram showing signal timing between IAF, Gateway, and G3fax. + +**Figure I.4 – IAF transmit timing from DCS to CFR** + +### I.2.2 Receiver is an IAF device, sender is G3fax + +#### *CFR signal send timing at the IAF device* + +It is recommended that IAF devices send the CFR signal, after taking into account the period during which the gateway receives TCF from the G3fax device. As Figure I.5 shows, this prevents the TCF from colliding with the CFR signal from the IAF device. + +![Sequence diagram showing IAF receive timing from DCS to CFR across G3fax, Gateway, and IAF lifelines.](68b20651884fcd557e865537f0803de5_img.jpg) + +``` + +sequenceDiagram + participant G3fax + participant Gateway + participant IAF + + IAF->>Gateway: DIS + Gateway->>G3fax: DIS + G3fax->>Gateway: DCS + Gateway->>IAF: DCS + G3fax->>Gateway: TCF + Gateway->>IAF: CFR + IAF->>Gateway: CFR + G3fax->>Gateway: CFR + +``` + +The diagram illustrates the timing of IAF receive operations across three lifelines: G3fax, Gateway, and IAF. The sequence of events is as follows: + +- DIS (Destination Indication Signal):** IAF sends DIS to Gateway, which then forwards it to G3fax. +- DCS (Data Call Setup):** G3fax sends DCS to Gateway, which then forwards it to IAF. +- TCF (Transfer Call Forwarding):** G3fax sends TCF to Gateway. +- CFR (Call Forwarding Request):** Gateway sends CFR to IAF, and IAF sends CFR back to Gateway. Simultaneously, G3fax sends CFR to Gateway. + +A bracket on the IAF lifeline indicates a period of time during which the DCS and CFR messages are received. The label T.38\_FI.5(APPI) is located at the bottom right of the IAF lifeline. + +Sequence diagram showing IAF receive timing from DCS to CFR across G3fax, Gateway, and IAF lifelines. + +**Figure I.5 – IAF receive timing from DCS to CFR** + +# Appendix II + +## Examples of call establishment procedures described in Annex B of ITU-T T.38 + +(This appendix does not form an integral part of this Recommendation.) + +## II.1 Sequence examples of call establishment procedures + +### II.1.1 Between Annex B of ITU-T T.38 gateways + +![Sequence diagram showing call establishment between two Annex B/ITU-T T.38 gateways. The diagram involves four lifelines: Sending G3FE, Emitting GW, Receiving GW, and Receiving G3FE. The sequence of events is: 1. Sending G3FE sends 'Off hook' to Emitting GW. 2. Emitting GW sends 'Dial tone' to Sending G3FE. 3. Sending G3FE sends 'Dialling number' to Emitting GW. 4. Emitting GW sends 'Q:SETUP[H:OLC]a)' to Receiving GW. 5. Receiving GW sends 'Q:CALL PROC' to Emitting GW. 6. Receiving GW sends 'Q:ALERT' to Emitting GW. 7. Receiving GW sends 'Q:CONNECT[H:OLC]b)' to Emitting GW. 8. Receiving GW sends 'Open FAX channelc)' to Receiving G3FE. 9. Receiving G3FE sends 'Open FAX channelc)' to Receiving GW. 10. A box labeled 'ITU-T T.38 session' spans from the 'Q:CONNECT' message to the 'Q:REL COMP' message. 11. Emitting GW sends 'On hook' to Sending G3FE. 12. Emitting GW sends 'Q:REL COMP' to Receiving GW. 13. Receiving GW sends 'Busy tone' to Receiving G3FE. 14. Receiving G3FE sends 'On hook' to Receiving GW.](64bec4cd45e47e1976245711f702aca2_img.jpg) + +``` + +sequenceDiagram + participant S as Sending G3FE + participant E as Emitting GW + participant R as Receiving GW + participant RG as Receiving G3FE + + S->>E: Off hook + E->>S: Dial tone + S->>E: Dialling number + E->>R: Q:SETUP[H:OLC]a) + R-->>E: Q:CALL PROC + R-->>E: Q:ALERT + R->>E: Q:CONNECT[H:OLC]b) + R->>RG: Open FAX channelc) + RG->>R: Open FAX channelc) + Note over E,R: ITU-T T.38 session + E->>S: On hook + E->>R: Q:REL COMP + R->>RG: Busy tone + RG->>R: On hook + +``` + +Sequence diagram showing call establishment between two Annex B/ITU-T T.38 gateways. The diagram involves four lifelines: Sending G3FE, Emitting GW, Receiving GW, and Receiving G3FE. The sequence of events is: 1. Sending G3FE sends 'Off hook' to Emitting GW. 2. Emitting GW sends 'Dial tone' to Sending G3FE. 3. Sending G3FE sends 'Dialling number' to Emitting GW. 4. Emitting GW sends 'Q:SETUP[H:OLC]a)' to Receiving GW. 5. Receiving GW sends 'Q:CALL PROC' to Emitting GW. 6. Receiving GW sends 'Q:ALERT' to Emitting GW. 7. Receiving GW sends 'Q:CONNECT[H:OLC]b)' to Emitting GW. 8. Receiving GW sends 'Open FAX channelc)' to Receiving G3FE. 9. Receiving G3FE sends 'Open FAX channelc)' to Receiving GW. 10. A box labeled 'ITU-T T.38 session' spans from the 'Q:CONNECT' message to the 'Q:REL COMP' message. 11. Emitting GW sends 'On hook' to Sending G3FE. 12. Emitting GW sends 'Q:REL COMP' to Receiving GW. 13. Receiving GW sends 'Busy tone' to Receiving G3FE. 14. Receiving G3FE sends 'On hook' to Receiving GW. + +T.38(15)\_FII.1.1 + +- Mandatory +- Optional +- Conditional + +Q: ITU-T Q.931 message within ITU-T H.225.0 +H: ITU-T H.245 message + +a) SETUP contains Setup-UIE, which includes fastStart element that is linked to *OpenLogicalChannel (OLC)* of ITU-T H.245. + +b) CONNECT contains Connect-UIE which includes fastStart element which is linked to *OpenLogicalChannel (OLC)* of ITU-T H.245. + +c) FAX channel is opened using either TCP or UDP. This phase specifically describes the operation of TCP connection between Annex B/ITU-T T.38 devices. When UDP applies, this phase does not appear because UDP is connection-less transport. + +NOTE – Basically, the same between-gateway sequences will apply to the Internet aware fax devices which do not function as a gateway to G3FE. + +### II.1.2 Between Annex B of ITU-T T.38 and Annex D of ITU-T H.323 gateways + +#### II.1.2.1 Normal connection and disconnection sequence (Annex B of ITU-T T.38 supporting only FAX) + +![Sequence diagram showing the normal connection and disconnection sequence between Annex D/ITU-T H.323 and Annex B/ITU-T T.38 gateways.](d3162014eae89d17bf0117dabb0c8796_img.jpg) + +The diagram illustrates the sequence of events for a normal connection and disconnection between an Annex D/ITU-T H.323 gateway and an Annex B/ITU-T T.38 gateway. + +**Participants:** + +- Annex D/ITU-T H.323:** + - Sending G3FE + - Emitting GW +- Annex B/ITU-T T.38:** + - Receiving GW + - Receiving G3FE + +**Sequence of Events:** + +- Off hook:** Sending G3FE sends an "Off hook" signal to Emitting GW. +- Dial tone:** Emitting GW sends a "Dial tone" signal back to Sending G3FE. +- Dialling number:** Sending G3FE sends a "Dialling number" signal to Emitting GW. +- Q:SETUP[H:OLC]a):** Emitting GW sends a "Q:SETUP[H:OLC]a)" signal to Receiving GW. +- Q:CALL PROC:** Receiving GW sends a "Q:CALL PROC" signal back to Emitting GW. +- Q:ALERT:** Receiving GW sends a "Q:ALERT" signal back to Emitting GW. +- Ringing:** Receiving GW sends a "Ringing" signal to Receiving G3FE. +- Q:CONNECT[H:OLC]b):** Emitting GW sends a "Q:CONNECT[H:OLC]b)" signal to Receiving GW. +- Off hook:** Receiving G3FE sends an "Off hook" signal to Receiving GW. +- Q: FACILITYc):** Receiving GW sends a "Q: FACILITYc)" signal back to Emitting GW. +- Q: FACILITYc):** Receiving GW sends a "Q: FACILITYc)" signal back to Emitting GW. +- Open FAX channel:** Receiving GW sends an "Open FAX channel" signal back to Emitting GW. +- Open FAX channel:** Receiving GW sends an "Open FAX channel" signal back to Emitting GW. +- ITU-T T.38 session:** A box labeled "ITU-T T.38 session" spans the duration of the connection between the gateways. +- On hook:** Sending G3FE sends an "On hook" signal to Emitting GW. +- Q:REL COMP:** Emitting GW sends a "Q:REL COMP" signal to Receiving GW. +- Busy tone:** Receiving GW sends a "Busy tone" signal to Receiving G3FE. +- On hook:** Receiving G3FE sends an "On hook" signal back to Receiving GW. + +Sequence diagram showing the normal connection and disconnection sequence between Annex D/ITU-T H.323 and Annex B/ITU-T T.38 gateways. + +T.38(15)\_Fil.1.2-1 + +- a) Annex D/ITU-T H.323 implementation uses fastStart element to send OLCs which include voice and facsimile capabilities. +- b) Annex B/ITU-T T.38 implementation returns OLC which includes only facsimile capability in response to SETUP from Annex D/ITU-T H.323 implementation. Note that Annex B/ITU-T T.38 implementation does not return the value of ITU-T H.245 port. +- c) Annex D/ITU-T H.323 implementation needs to open ITU-T H.245 channel to exchange capabilities which have not been sent. Thus, it sends a FACILITY message with a FacilityReason of startH245 to facilitate opening ITU-T H.245 channel with the peer. In response, Annex B/ITU-T T.38 implementation returns a FACILITY message with a FacilityReason of noH245 to indicate that it does not support ITU-T H.245 operation. This sequence allows FAX communication without opening ITU-T H.245 channel when Annex D/ITU-T H.323 implementation does not need a voice channel. + +#### II.1.2.2 Normal connection and disconnection sequence (Annex B of ITU-T T.38 supporting FAX and voice) + +![Sequence diagram showing the normal connection and disconnection sequence between Annex D/ITU-T H.323 and Annex B/ITU-T T.38. The diagram involves four entities: Sending G3FE, Emitting GW, Receiving GW, and Receiving G3FE. The sequence includes off-hook, dialing, Q:SETUP, Q:CALL PROC, Q:ALERT, Q:CONNECT, voice session, opening FAX channels, ITU-T T.38 session, on-hook, Q:REL COMP, busy tone, and final on-hook.](633fb609c4b7e841224c558b9db215bf_img.jpg) + +``` + +sequenceDiagram + participant S as Annex D/ITU-T H.323 +Sending G3FE + participant E as Emitting GW + participant R as Annex B/ITU-T T.38 +Receiving GW + participant G as Receiving G3FE + + S->>E: Off hook + E->>S: Dial tone + S->>E: Dialling number + E->>R: Q:SETUP[H:OLC]a) + R-->>E: Q:CALL PROC + R-->>E: Q:ALERT + E->>G: Ringing + G->>E: Off hook + E->>R: Q:CONNECT[H:OLC]b) + Note over E,R: Voice session + E->>R: Open FAX channelc) + R->>E: Open FAX channelc) + Note over E,R: ITU-T T.38 session + E->>S: On hook + E->>R: Q:REL COMP + R->>G: Busy tone + G->>R: On hook + +``` + +Sequence diagram showing the normal connection and disconnection sequence between Annex D/ITU-T H.323 and Annex B/ITU-T T.38. The diagram involves four entities: Sending G3FE, Emitting GW, Receiving GW, and Receiving G3FE. The sequence includes off-hook, dialing, Q:SETUP, Q:CALL PROC, Q:ALERT, Q:CONNECT, voice session, opening FAX channels, ITU-T T.38 session, on-hook, Q:REL COMP, busy tone, and final on-hook. + +T.38(15)\_Fil.1.2-2 + +- a) Annex D/ITU-T H.323 implementation uses fastStart element to send OLC, which includes voice capability as minimum. +- b) Annex B/ITU-T T.38 implementation returns OLCs which include both voice and facsimile capabilities in response to SETUP from Annex D/ITU-T H.323 implementation. Note that Annex B/ITU-T T.38 implementation supporting voice and FAX is capable of ITU-T H.245 procedures. +- c) This opens the FAX channel negotiated by exchanging OLCs in ITU-T H.245 procedures from both directions. Note that variables such as the voice conversation, CNG, CED and ITU-T V.21 signals (which do not appear in the figure) will trigger the sequence. Annex D/ITU-T H.323 and Annex B/ITU-T T.38 implementations need to recognize ITU-T T.30 signals (such as CNG, CED and ITU-T V.21) sent from the peer terminal. These cannot be forwarded via ITU-T T.38 until the FAX channel is opened. +- NOTE 1 – Annex B/ITU-T T.38 supporting FAX and optional voice shall use the methods in Annex D/ITU-T H.323 as described in B.3.1.1. Thus, the above figure shows the sequences conforming to Annex D/ITU-T H.323. +- NOTE 2 – The switching mechanism should refer to section "D.5 replacing an existing audio stream with a ITU-T T.38 fax stream" in Annex D/ITU-T H.323. + +#### II.1.2.3 Connection rejected sequence 1 (when the calling side, Annex D of ITU-T H.323, does not support Fast Connect Procedures) + +![Sequence diagram for Connection rejected sequence 1. The diagram shows four lifelines: Sending G3FE (Annex D/ITU-T H.323), Emitting GW, Receiving GW (Annex B/ITU-T T.38), and Receiving G3FE. The sequence of events is: 1. Sending G3FE sends 'Off hook' to Emitting GW. 2. Emitting GW sends 'Dial tone' to Sending G3FE. 3. Sending G3FE sends 'Dialling number' to Emitting GW. 4. Emitting GW sends 'Q:SETUP[H:OLC]' to Receiving GW. 5. Receiving GW sends 'Q:REL COMPa)' back to Emitting GW. The diagram is labeled T.38(15)_FII.1.2-3.](c19f37cdfc7768db716bfc0cc5934cfb_img.jpg) + +``` + +sequenceDiagram + participant S as Sending G3FE +(Annex D/ITU-T H.323) + participant E as Emitting GW + participant R as Receiving GW +(Annex B/ITU-T T.38) + participant RG as Receiving G3FE + + S->>E: Off hook + E->>S: Dial tone + S->>E: Dialling number + E->>R: Q:SETUP[H:OLC] + R->>E: Q:REL COMPa) + +``` + +T.38(15)\_FII.1.2-3 + +Sequence diagram for Connection rejected sequence 1. The diagram shows four lifelines: Sending G3FE (Annex D/ITU-T H.323), Emitting GW, Receiving GW (Annex B/ITU-T T.38), and Receiving G3FE. The sequence of events is: 1. Sending G3FE sends 'Off hook' to Emitting GW. 2. Emitting GW sends 'Dial tone' to Sending G3FE. 3. Sending G3FE sends 'Dialling number' to Emitting GW. 4. Emitting GW sends 'Q:SETUP[H:OLC]' to Receiving GW. 5. Receiving GW sends 'Q:REL COMPa)' back to Emitting GW. The diagram is labeled T.38(15)\_FII.1.2-3. + +a) Annex B/ITU-T T.38 implementation rejects connection by sending ITU-T Q.931: RELEASE COMPLETE when it receives SETUP message without fastStart element. + +#### II.1.2.4 Connection rejected sequence 2 (when the called side, Annex D of ITU-T H.323, does not support Fast Connect Procedures) + +![Sequence diagram for Connection rejected sequence 2. The diagram shows four lifelines: Sending G3FE (Annex B/ITU-T T.38), Emitting GW, Receiving GW (Annex D/ITU-T H.323), and Receiving G3FE. The sequence of events is: 1. Sending G3FE sends 'Off hook' to Emitting GW. 2. Emitting GW sends 'Dial tone' to Sending G3FE. 3. Sending G3FE sends 'Dialling number' to Emitting GW. 4. Emitting GW sends 'Q:SETUP[H:OLC]' to Receiving GW. 5. Receiving GW sends 'Q:CONNECT[H:OLC]' back to Emitting GW. 6. Receiving GW sends 'Q:REL COMPa)' back to Emitting GW. The diagram is labeled T.38(15)_FII.1.2-4.](54159e6d8f5ecc73ad262758e3a60677_img.jpg) + +``` + +sequenceDiagram + participant S as Sending G3FE +(Annex B/ITU-T T.38) + participant E as Emitting GW + participant R as Receiving GW +(Annex D/ITU-T H.323) + participant RG as Receiving G3FE + + S->>E: Off hook + E->>S: Dial tone + S->>E: Dialling number + E->>R: Q:SETUP[H:OLC] + R->>E: Q:CONNECT[H:OLC] + R->>E: Q:REL COMPa) + +``` + +T.38(15)\_FII.1.2-4 + +Sequence diagram for Connection rejected sequence 2. The diagram shows four lifelines: Sending G3FE (Annex B/ITU-T T.38), Emitting GW, Receiving GW (Annex D/ITU-T H.323), and Receiving G3FE. The sequence of events is: 1. Sending G3FE sends 'Off hook' to Emitting GW. 2. Emitting GW sends 'Dial tone' to Sending G3FE. 3. Sending G3FE sends 'Dialling number' to Emitting GW. 4. Emitting GW sends 'Q:SETUP[H:OLC]' to Receiving GW. 5. Receiving GW sends 'Q:CONNECT[H:OLC]' back to Emitting GW. 6. Receiving GW sends 'Q:REL COMPa)' back to Emitting GW. The diagram is labeled T.38(15)\_FII.1.2-4. + +a) Annex B/ITU-T T.38 implementation rejects connection by sending ITU-T Q.931: RELEASE COMPLETE when it receives CONNECT message without fastStart element in response to its SETUP message with fastStart element. + +### II.1.3 Between Annex B of ITU-T T.38 supporting FAX and Annex D of ITU-T H.323 gateways that are both registered to the same Gatekeeper + +#### II.1.3.1 Normal connection sequence (when Gatekeeper has chosen Direct Call Signalling) + +![Sequence diagram showing the normal connection sequence between Annex D/ITU-T H.323 and Annex B/ITU-T T.38 gateways. The diagram involves five entities: Sending G3FE, Emitting GW, Gatekeeper, Receiving GW, and Receiving G3FE. The sequence starts with 'Off hook' from Sending G3FE to Emitting GW, followed by 'Dial tone' and 'Dialling number'. Then, 'R:ARQ' and 'R:ACF' messages are sent between the Emitting GW and the Gatekeeper. The Gatekeeper sends 'Q:SETUP[H:OLC]' to the Receiving GW, which triggers 'Ringing' at the Receiving G3FE. Subsequent messages include 'Q:CALL PROC', 'R:ARQ', 'R:ACF', 'Q:ALERT', and 'Q:CONNECT[H:OLC]' between the Gatekeeper and the Receiving GW. The Receiving GW then sends 'Off hook' to the Receiving G3FE. Finally, 'Open FAX channel' messages are sent from the Emitting GW to the Receiving GW. A box at the bottom indicates the 'ITU-T T.38 session' duration.](88fa0e6558e55b5d54f4d3029b21aabb_img.jpg) + +``` + +sequenceDiagram + participant S as Sending G3FE + participant E as Emitting GW + participant G as Gatekeeper + participant R as Receiving GW + participant Re as Receiving G3FE + + S->>E: Off hook + E->>S: Dial tone + S->>E: Dialling number + E->>G: R:ARQ + G->>E: R:ACF + G->>R: Q:SETUP[H:OLC] + R->>Re: Ringing + R->>G: Q:CALL PROC + G->>R: R:ARQ + R->>G: R:ACF + G->>R: Q:ALERT + R->>G: Q:CONNECT[H:OLC] + R->>Re: Off hook + E->>R: Open FAX channel + R-->>E: Open FAX channel + Note over E, R: ITU-T T.38 session + +``` + +Sequence diagram showing the normal connection sequence between Annex D/ITU-T H.323 and Annex B/ITU-T T.38 gateways. The diagram involves five entities: Sending G3FE, Emitting GW, Gatekeeper, Receiving GW, and Receiving G3FE. The sequence starts with 'Off hook' from Sending G3FE to Emitting GW, followed by 'Dial tone' and 'Dialling number'. Then, 'R:ARQ' and 'R:ACF' messages are sent between the Emitting GW and the Gatekeeper. The Gatekeeper sends 'Q:SETUP[H:OLC]' to the Receiving GW, which triggers 'Ringing' at the Receiving G3FE. Subsequent messages include 'Q:CALL PROC', 'R:ARQ', 'R:ACF', 'Q:ALERT', and 'Q:CONNECT[H:OLC]' between the Gatekeeper and the Receiving GW. The Receiving GW then sends 'Off hook' to the Receiving G3FE. Finally, 'Open FAX channel' messages are sent from the Emitting GW to the Receiving GW. A box at the bottom indicates the 'ITU-T T.38 session' duration. + +T.38(15)\_Fil.1.3-1 + +R RAS (Registration, admission and status) messages + +NOTE – Various call models are described in 8.1/ITU-T H.323. + +## II.2 Protocol data used in call establishment procedures + +### II.2.1 General + +Two Recommendations – [ITU-T H.225.0] (as a subset of [ITU-T Q.931]) and [ITU-T H.245] – define the protocol data used in Call establishment procedures of Annex B, while [ITU-T H.323] gives the general protocol design of the whole system. For example, SETUP message is defined in Table 13 of [ITU-T H.225.0] and its user-user information element (UUIE) is defined as Setup-UUIE under H323-UU-PDU in [ITU-T H.225.0]. Then fastStart element which is defined as SEQUENCE OF OCTET STRING by ASN.1 definition of Setup-UUIE encapsulates OpenLogicalChannel which is defined under MultimediaSystemControlMessage in [ITU-T H.245]. + +Additionally, RAS messages need to be understood to fully implement Annex B. RAS is also defined in [ITU-T H.225.0] as RasMessage using ASN.1 and Table 18 of [ITU-T H.225.0] gives its support requirements. + +### II.2.2 Examples of the protocol data + +#### II.2.2.1 Supported ITU-T H.225.0 (ITU-T Q.931) message types + +Tables II.1 to II.3 show the supported ITU-T H.225.0 (ITU-T Q.931) message types in three phases. + +**Table II.1 – Messages of call setup phase** + +| Message type | transmit | receive | +|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------|---------| +| ALERT | CM a) | M | +| CALL PROC | CM a) | M | +| CONNECT | M | M | +| CONNECT ACK | F | F | +| PROGRESS | O | O | +| SETUP | M | M | +| SETUP ACK | O | O | +| M Mandatory
O Optional
F Forbidden
CM Conditional Mandatory
a) Note that gateways shall send ALERT and CALL PROC messages while IAF (Internet-aware fax) may not send them. Note that Annex D of [ITU-T H.323] GW may send ALERTING or CALL PROC to an IAF. | | | + +**Table II.2 – Messages of call release phase** + +| Message type | transmit | receive | +|--------------|----------|---------| +| DISCONNECT | F | F | +| RELEASE | F | F | +| RELEASE COMP | M | M | + +**Table II.3 – Messages of other phase** + +| Message type | transmit | receive | +|--------------------------------------------------------------------------------------------------------------------------------------------------------|------------------|-----------------| +| FACILITY | CM a) | M a) | +| a) Note that Annex B of ITU-T T.38 implementation shall receive and send FACILITY when connecting to Annex D of ITU-T H.323 implementation. | | | + +#### II.2.2.2 Information elements of SETUP + +Tables II.4 to II.6 show information elements of SETUP message. + +**Table II.4 – Information elements of SETUP** + +| Information element | Parameter | Status | Description | +|--------------------------|------------------------------|--------|------------------------------------------------| +| Protocol discriminator | Reference
[ITU-T H.225.0] | M | | +| Call reference | Reference
[ITU-T H.225.0] | M | | +| Message type | Reference
[ITU-T H.225.0] | M | | +| Bearer capability | Reference
[ITU-T H.225.0] | M | | +| Calling party number | Reference
[ITU-T H.225.0] | O | | +| Calling party subaddress | Reference
[ITU-T H.225.0] | CM | | +| Called party number | Reference
[ITU-T H.225.0] | O | | +| Called party subaddress | Reference
[ITU-T H.225.0] | CM | | +| User-user | protocolIdentifier | M | ITU-T H.225.0 version number | +| | SourceInfo | M | EndpointType | +| | destinationAddress | M | Used by Gatekeeper | +| | destCallSignalAddress | M | TransportAddress
(IP address + Port number) | +| | activeMC | M | FALSE | +| | conferenceID | M | NULL | +| | conferenceGoal | M | NULL | +| | callType | M | PointToPoint | +| | callIdentifier | M | GloballyUniqueID | +| | mediaWaitForConnect | M | TRUE | +| | canOverlapSend | M | if TRUE, support overlap sending | +| | fastStart | M | Reference: Table II.5 | + +**Table II.5 – Parameters of fastStart(OpenLogicalChannel)** + +| Parameters | Description | +|---------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ForwardLogicalChannelNumber | | +| ForwardLogicalChannelParameters | | +| PortNumber | | +| Data Type | Reference: Table II.6
dateType is linked with DataApplicationCapability in Annex B.
Note that DataApplicationCapability in Annex B is only extraction among CHOICES of application of [ITU-T H.245]. | + +**Table II.5 – Parameters of fastStart(OpenLogicalChannel)** + +| Parameters | Description | +|---------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| MultiplexParameters | sessionID, mediaChannel and mediaControlChannel in H2250LogicalChannelParameters | +| ReverseLogicalChannelParameters | | +| DataType | Reference: Table II.6
dateType is linked with DataApplicationCapability in Annex B.
Note that DataApplicationCapability in Annex B is only extraction among CHOICES of application of [ITU-T H.245]. | +| MultiplexParameters | sessionID, mediaChannel and mediaControlChannel in H2250LogicalChannelParameters | + +**Table II.6 – Parameters of dataType(DataApplicationCapability)** + +| Parameter | Status | Description | +|----------------------|--------|--------------------------------------------------------------------------------------------| +| Application | – | CHOICE index shall be encoded to indicate the use of t38fax. | +| t38fax | M | | +| t38FaxProtocol | M | CHOICE index of DataProtocolCapability shall be encoded to indicate the use of TCP or UDP. | +| t38FaxProfile | M | | +| FilBitRemoval | M | | +| TranscodingJBIG | M | | +| TranscodingMMR | M | | +| Version | M | | +| t38FaxRateManagement | M | CHOICE index shall be encoded to indicate the use of localTCF or transferredTCF. | +| t38FaxUdpOptions | O | | +| t38FaxMaxBuffer | O | | +| t38FaxMaxDatagram | O | | +| t38FaxUdpEC | O | CHOICE index shall be encoded to indicate the use of t38UDPFEC or t38UDPRedundancy. | +| MaxBitRate | M | Units 100 bit/s | + +#### **II.2.2.3 Information elements of ALERT** + +Table II.7 shows information elements of ALERT message. + +**Table II.7 – Information elements of ALERT** + +| Information element | Parameter | Status | Description | +|------------------------|------------------------------|--------|-------------| +| Protocol discriminator | Reference
[ITU-T H.225.0] | M | | +| Call reference | Reference
[ITU-T H.225.0] | M | | +| Message type | Reference
[ITU-T H.225.0] | M | | +| User-user | Reference
[ITU-T H.225.0] | M | | + +#### **II.2.2.4 Information elements of CALL PROC** + +Table II.8 shows information elements of CALL PROC message. + +**Table II.8 – Information elements of CALL PROC** + +| Information element | Parameter | Status | Description | +|------------------------|------------------------------|--------|-------------| +| Protocol discriminator | Reference
[ITU-T H.225.0] | M | | +| Call reference | Reference
[ITU-T H.225.0] | M | | +| Message type | Reference
[ITU-T H.225.0] | M | | +| User-user | Reference
[ITU-T H.225.0] | M | | + +#### **II.2.2.5 Information elements of CONNECT** + +Table II.9 shows information elements of CONNECT message. + +**Table II.9 – Information elements of CONNECT** + +| Information element | Parameter | Status | Description | +|------------------------|------------------------------|--------|------------------------------| +| Protocol discriminator | Reference
[ITU-T H.225.0] | M | | +| Call reference | Reference
[ITU-T H.225.0] | M | | +| Message type | Reference
[ITU-T H.225.0] | M | | +| User-user | protocolIdentifier | M | ITU-T H.225.0 version number | +| | destinationInfo | M | EndpointType | +| | conferenceID | M | NULL | +| | callIdentifier | M | GloballyUniqueID | +| | FastStart | M | Reference: Table II.5 | + +#### II.2.2.6 Information elements of RELEASE COMPLETE + +Table II.10 shows information elements of RELEASE COMPLETE message. + +**Table II.10 – Information elements of RELEASE COMPLETE** + +| Information element | Parameter | Status | Description | +|------------------------|------------------------------|--------|-----------------------------------------------------------------------------| +| Protocol discriminator | Reference
[ITU-T H.225.0] | M | | +| Call reference | Reference
[ITU-T H.225.0] | M | | +| Message type | Reference
[ITU-T H.225.0] | M | | +| Cause | Reference
[ITU-T H.225.0] | CM | Either the Cause IE or ReleaseCompleteReason in User-user shall be present. | +| User-user | Reference
[ITU-T H.225.0] | M | | + +#### II.2.2.7 Information elements of FACILITY + +Table II.11 shows information elements of FACILITY message. + +**Table II.11 – Information elements of FACILITY** + +| Information element | Parameter | Status | Description | +|------------------------|------------------------------|--------|------------------------------| +| Protocol discriminator | Reference
[ITU-T H.225.0] | M | | +| Call reference | Reference
[ITU-T H.225.0] | M | | +| Message type | Reference
[ITU-T H.225.0] | M | | +| User-user | protocolIdentifier | M | ITU-T H.225.0 version number | +| | reason | M | FacilityReason | +| | callIdentifier | M | GloballyUniqueID | + +# **Appendix III** + +## **ITU-T H.248 call establishment procedure examples for facsimile-capable media gateways** + +(This appendix does not form an integral part of this Recommendation.) + +## **III.1 Introduction** + +This appendix describes examples of the procedures for Internet-aware facsimile implementations and Internet-aware facsimile gateways conforming to this Recommendation to establish calls with other ITU-T T.38 implementations using the procedures defined by Annex E and [ITU-T H.248.1]. In addition, this appendix describes examples of MG/MGC interactions for establishing a call between ITU-T H.248 endpoints and ITU-T H.323 endpoints. The examples are divided into two main categories: + +- Call set-up procedures that allow MGs to transition from voice/audio state to ITU-T T.38 state using the MGC controlled method; +- Call set-up procedures that allow MGs to autonomously transition from voice/audio state to ITU-T T.38 state. + +## **III.2 Examples of call set-up** + +### **III.2.1 Voice to fax call set-up with ITU-T H.248 endpoints using the ITU-T T.38 transitioning method** + +This call flow example describes a voice call that originates and terminates in the SCN and is transported through the packet network. The packet network signalling in this example is not specified but any signalling protocol such as [ITU-T H.323] or SIP can be used – the purpose of the example is to describe MG/MGC interactions, involved when the MGs and the MGC support the MGC procedure, including the detection of fax and switching from voice to fax. + +![Sequence diagram showing the voice to fax call setup process between G3FE1, MG1, MGC, MG2, and G3FE2. The process is divided into Voice mode and Fax mode. Voice mode includes steps for audit, setup, context creation, ringing, and CNG detection. Fax mode includes steps for ITU-T V.21 preamble, modify, and packet transmission.](49d7bfbc65a92a7e1bd61777326a212d_img.jpg) + +``` + +sequenceDiagram + participant G3FE1 + participant MG1 + participant MGC + participant MG2 + participant G3FE2 + + Note over G3FE1, MG1: 2. OFF HOOK + Note over G3FE1, MG1: 2. DIAL TONE + Note over G3FE1, MG1: 2. DIALLING + Note over MG1, MGC: 1. AUDIT + Note over MG1, MGC: 1. REPLY + Note over MGC, MG2: 1. AUDIT + Note over MGC, MG2: 1. REPLY + Note over MG1, MGC: 2. SETUP (SCTP) + Note over MG1, MGC: 3. CREATE CONTEXT + Note over MG1, MGC: 4. ACK + Note over MGC, MG2: 5. CREATE CONTEXT + Note over MGC, MG2: 6. ACK + + Note over G3FE1, MG1, MGC, MG2, G3FE2: Voice mode + + Note over MG1, MGC: 7. RINGING + Note over MG1, MGC: 7. ACK + Note over G3FE1, MG1: 8. CNG + Note over MG1, MGC: 8. CNG DETECTED + Note over MG1, MGC: 8. ACK + Note over MGC, MG2: 8. PLAY CNG + Note over MGC, MG2: 8. ACK + Note over MG2, G3FE2: 8. CNG + Note over MG2, G3FE2: 9. CED + Note over MGC, MG2: 9. CED DETECTED + Note over MGC, MG2: 9. ACK + Note over MG1, MGC: 10. PLAY CED + Note over MG1, MGC: 10. ACK + Note over G3FE1, MG1: 10. CED + Note over MG1, MGC: 11. PLAY ITU-T V.21 + Note over MG1, MGC: 11. ACK + Note over MGC, MG2: 11. ITU-T V.21 DETECTED + Note over MGC, MG2: 11. ACK + Note over MG2, G3FE2: 11. ITU-T V.21 preamble + flags + Note over MG1, MGC: 12. MODIFY + Note over MG1, MGC: 12. ACK + Note over MGC, MG2: 13. MODIFY + Note over MGC, MG2: 14. ACK + Note over MG1, MGC: 15. MODIFY + Note over MG1, MGC: 16. ACK + Note over MGC, MG2: 17. MODIFY + Note over MGC, MG2: 17. ACK + + Note over G3FE1, MG1, MGC, MG2, G3FE2: Fax mode + + Note over MG1, MGC: ITU-T T.38 ITU-T V.21 PACKET + Note over MG2, G3FE2: ITU-T V.21 preamble + flags + +``` + +Sequence diagram showing the voice to fax call setup process between G3FE1, MG1, MGC, MG2, and G3FE2. The process is divided into Voice mode and Fax mode. Voice mode includes steps for audit, setup, context creation, ringing, and CNG detection. Fax mode includes steps for ITU-T V.21 preamble, modify, and packet transmission. + +T.38(15)\_FIII.1 + +Figure III.1 – Voice to fax call set-up with ITU-T H.248 endpoints + +The sequence of events is as follows: + +- 1) At some point before a call, the media gateway controller will have issued an audit capabilities command to the media gateways under its control and will know what the voice and fax capabilities are for each gateway. In the scenarios below, if both Media Gateways support ITU-T T.38, then this is the preferred mode for IP fax operations. In the event that one or both media gateways do not support ITU-T T.38, then the fax call may proceed over the IP voice channel. However, since ITU-T T.30 facsimile may fail over a compressed voice codec, it would be preferable to use an ITU-T G.711 codec for communication between the media gateways. 'W-' is used to indicate that a wild-card answer with a union of information on all terminations on the MG is requested, not an audit of each termination on the MG. In the example, MG1 indicates support of ITU-T T.38; however, the audit shall not be used to infer support of either the ITU-T T.38 autonomous transitioning method or the ITU-T T.38 MGC transitioning method as described in clause E.2.2. This shall be done on a call-by-call basis during the Add Ephemeral (see point 3 below). + +The MGC audits MG1. + +MGC to MG1: + +``` +MEGACO/1 [123.123.123.4]:55555 +Transaction = 9 { + Context = - {W-AuditValue = * {Audit{Packages}}} +``` + +MG1 replies. MG1 to MGC: + +``` +MEGACO/1 [125.125.125.111]:55555 +Reply = 9 { + Context = - { + AuditValue = * { + Packages {al, rtp, ipfax, fax, ctyp, cg} + ; al = analog line pkg, rtp = rtp pkg, ipfax = ITU-T T.38 fax pkg, fax = fax pkg + ; ftmd = fax/textphone/modem tones detection pkg + ; ctyp = Call Type Discrimination package) + ; cg =call progress tones generator pkg + } + } +} +``` + +``` +MEGACO/1 [123.123.123.4]:55555 +Transaction = 10 { + Context = - {W-AuditCapabilities = * {Audit{Media }}} +``` + +MG1 replies. MG1 to MGC: + +``` +MEGACO/1 [125.125.125.111]:55555 +Reply = 10 { + Context = - { + AuditValue = * { + Media { + Stream = 1 { + Local { +v=0 +c=IN IP4 $ +m=audio $ RTP/AVP 0 18 +v=0 +c=IN IP4 $ +m=image $ udpt1 t38 + } ; RTP profile for G.711 is 0, G.729 is 18, t38 is ITU-T T.38 + } + }, +``` + +``` + + } + } +} + +``` + +A similar exchange happens between the MGC and MG2. + +- 2) The end user decides to send a fax from device F1 and enters the phone number. The fax device gets dial tone and then dials the phone number. As a result, the central office within the local SCN loop sends an SS7 message to the signalling gateway (SG). The SG sends a *Setup* message to the MGC after receiving this IAM from a SCN switch that conveys the called and calling phone numbers. SCTP (for example) carries the SS7 signalling from the SG to the MGC. +- 3) From the IAM message, the MGC may infer which circuit on which MG is involved and where to terminate the call. How the MGC does this is outside the scope of this appendix. The endpoints are found by the media gateway controller (MGC) and it sets up the audio channel between the two media gateways and instructs the SS7 facility of the receiving CO to connect to the end phone destination, which results in the generation of ringing. So, to start, the controller determines that a connection needs to be made from MG1 to MG2. The MGC creates a Context for the call. Both the TDM termination DS0/1/1, and an RTP termination are added to a new context in MG1. Mode is ReceiveOnly since Remote descriptor values are not yet specified. Preferred codecs are in the MGC's preferred order of choice. The MGC sets to CHOOSE (i.e., \$) the fields in the SDP in the Local descriptor that the MG will set itself. Also, in order for the MGC to infer whether both gateways support the ITU-T T.38 autonomous transitioning method or ITU-T T.38 MGC transitioning method, the MGC instructs MG1 to respond with the values of both its audio RTP/AVP capabilities and its image/t38 capabilities. Note that this is achieved by including in the LocalControl descriptor "ReserveGroup=True" to ask the MG to reserve resources for both audio and image media descriptors. In addition, "ReserveValue = True" to ask the MG to reserve resources for all the possible codecs offered in the media descriptor (alternatively, an MGC may include ReserveValue=false to ask for the most preferred codec; however, if omitted, a MG by default must set this value to false). + +MGC to MG1: + +``` + +MEGACO/1 [123.123.123.4]:55555 +Transaction = 11 { + Context = $ { + Add = DS0/1/1 { + Events = 1 {al/on, ctyp/dtone } + }, ; SCN termination prepared to listen for tones + Add = $ { + Media { + Stream = 1 { + LocalControl { Mode = ReceiveOnly, ReserveGroup = True, ReserveValue = +True}, + Local { +v=0 +c=IN IP4 $ +m=audio $ RTP/AVP 18 0 +v=0 +c=IN IP4 $ +m=image $ udpt1 t38 + }; IP termination for audio + } + } + } + } +} + +``` + +- 4) MG1 acknowledges the new Termination and fills in the Local IP address and UDP port. In this example, MG1 supports both offered codecs, hence returns both codecs in the same preference order provided by the MGC (thus leaving the final choice to MG2). MG1 sets the RTP port to 2222. Also, because MG1 does not support the ITU-T T.38 autonomous transitioning method for transitioning between VoIP and FoIP, it omits the image media descriptor line all together (alternatively, it could have set the ITU-T T.38 port to 0). + +``` +MEGACO/1 [124.124.124.222]:55555 +Reply = 11 { + Context = 2000 { + Add = DS0/1/1, ; SCN termination added + Add = RTP/1 { + Media { + Stream = 1 { + Local { +v=0 +c=IN IP4 124.124.124.222 +m=audio 2222 RTP/AVP 18 0 ;MG1 supports both offered codecs +aptime:20 + } ; IP termination added + } + } + } + } +} +``` + +- 5) Assume that the MGC has control over the remote MG2 also. The MGC, based on the reply of MG1, has inferred that the ITU-T T.38 MGC Transitioning method shall be used to transition between VoIP and FoIP, and will now associate DS0/2/2 with a new Context on MG2, and establish an RTP Stream (i.e., RTP/2 will be assigned), SendReceive connection through to the originating user, User 1. MGC includes in the LocalControl descriptor of the ephemeral termination the property "ReserveValue=False" to indicate to MG2 to select a codec. + +MGC to MG2: + +``` +MEGACO/1 [123.123.123.4]:55555 +Transaction = 30 { + Context = $ { + Add = DS0/2/2 { + Media { + Stream = 1 { + LocalControl {Mode = SendReceive } }, + Events = 10 {al/of, ctyp/dtone }, + Signals = {al/ri } + } + }, + Add = $ { + Media { + Stream = 1 { + LocalControl {Mode = SendReceive, ReserveValue=False }, + Local { +v=0 +c=IN IP4 $ +m=audio $ RTP/AVP 18 0 + }, + Remote { +v=0 +c=IN IP4 124.124.124.222 +m=audio 2222 RTP/AVP 18 0 +aptime:20 + } ; RTP profile for G.729 is 18 + } + } + } + } + } +} +``` + +``` + + } + } +} + +``` + +- 6) This is acknowledged. Also, based on the remote SDP provided, MG2 can infer that the ITU-T T.38 MGC transition method shall be used for transitioning from a VoIP state to a FoIP state. The stream port number is 1111 (in the SDP). Also, MG2 selects the first codec in the offered priority codec list as the preferred codec, i.e., ITU-T G.729 (RTP payload type = 18). + +MG2 to MGC: + +``` + +MEGACO/1 [125.125.125.111]:55555 +Reply = 30 { + Context = 5000 { + Add = DS0/2/2, + Add = RTP/2 { + Media { + Stream = 1 { + Local { +v=0 +c=IN IP4 125.125.125.111 +m=audio 1111 RTP/AVP 18 + } + } + } + } + } +} + +``` + +- 7) The above IPAddr, UDPport, and selected codec need to be given to MG1 now. Also, because the MGC knows that the ITU-T T.38 MGC transition method shall be used, it needs to indicate to MG1 that it has to detect facsimile tones and inform it appropriately as well as apply ringing tone ringback to the DS0/1/1 termination and change it to a SendReceive. + +MGC to MG1: + +``` + +MEGACO/1 [123.123.123.4]:55555 +Transaction = 12 { + Context = 2000 { + Modify = DS0/1/1 { +Events = 10 { ctyp/dtone}, ; detect facsimile tones + +Signals {cg/rt} }, ;apply ringing tone + Modify = RTP/1 { + Media { + Stream = 1 { + LocalControl {Mode = SendReceive } + Remote { +v=0 +c=IN IP4 125.125.125.111 +m=audio 1111 RTP/AVP 18 + } + } + } + } + } +} + +``` + +from MG1 to MGC: + +``` + +MEGACO/1 [124.124.124.222]:55555 +Reply = 12 { + Context = 2000 {Modify = DS0/1/1, Modify = RTP/1} +} + +``` + +- 8) The calling fax machine typically will start to generate CNG calling tones. When the CNG tone event is detected by the first media gateway (MG1), this event shall be reported to the media gateway controller. The media gateway controller then shall issue a command to the second media gateway (MG2) to generate a CNG tone. At this point, the full duplex channel is still in a voice mode and using the indicated audio codec such as ITU-T G.723.1 and ITU-T G.729A. + +from MG1 to MGC: + +``` +MEGACO/1 [124.124.124.222]:55555 +Transaction = 50 { + Context = 2000 { + Notify = DS0/1/1 { + ObservedEvents = 1 { + 19991212T22110001: ctyp/dtone{dtc=cng} } + } + } + } +} +``` + +from MGC to MG1: + +``` +MEGACO/1 [123.123.123.4]:55555 +Reply = 50 { + Context = 2000 {Notify = DS0/1/1} +} +``` + +MGC to MG2: + +``` +MEGACO/1 [123.123.123.4]:55555 +Transaction = 31 { + Context = 5000 { + Modify = DS0/2/2 { + Signals {ctyp/callsig{callSigname=cng}}; issue CNG at remote end + } + } +} +``` + +MG2 to MGC: + +``` +MEGACO/1 [125.125.125.111]:55555 +Reply = 31 { + Context = 5000 {Modify = DS0/2/2} +} +``` + +- 9) In the previous step, the MG2 generated a CNG tone requested by the MGC in the Signals descriptor. In the typical case, if the final destination phone number is fax capable, a CED tone will be generated by the recipient fax machine. This step is illustrated here. However, if there is not a fax receiver on the line, the typical response will be via voice. + +from MG2 to MGC: + +``` +MEGACO/1 [123.123.123.4]:55555 +Transaction = 70 { + Context = 5000 { + Notify = DS0/2/2 { + ObservedEvents = 10 { + 19991212T22110031: ctyp/dtone{dtc=ANS}}; CED and ANS are equivalent. Reported under the name ANS. + } + } + } +} +``` + +from MGC to MG2: + +``` +MEGACO/1 [125.125.125.111]:55555 +``` + +``` + +Reply = 70 { + Context = 5000 {Notify = DS0/2/2} +} + +``` + +- 10) Assuming that a CED has been generated by the recipient fax device, the MG2 will then receive the CED and uses its tone detection algorithms to detect that it actually is a CED. + +NOTE – Some research was done to check out modem answer tones, which are defined in ITU-T V.25 and [ITU-T V.8]. The modem answer tone without phase reversals is known as ANS in ITU-T V.25 and with answer tones is ANS (with a bar on top denoting Phase reversals). Some modems and DSPs may have a difficult time distinguishing among the CED, ANS and ANS(bar). However, the group felt that if a CED-like tone was generated in response to a CNG, there is a very high likelihood that the tone is indeed a CED and not one of the ANS tones. Higher end modems are able to discriminate between ANSam and the other modem and fax tones. + +Since a CNG was reported by the calling side and a CED by the called side, the media gateway controller will issue a command instructing MG1 to play the CED. Both media gateways shift into a fax mode (either ITU-T T.38 if supported, or [ITU-T G.711]). From this point, the ITU-T V.21 fax data will be conveyed between the media gateways. Note that at this point, the MGC could decide that there is sufficient confidence to switch to fax, unless, for example, some other answer tone has been detected, such as ANSam (see step 18). For the purpose of this example, it does not believe it has sufficient confidence. + +MGC to MG1: + +``` + +MEGACO/1 [123.123.123.4]:55555 +Transaction = 13 { + Context = 2000 { + Modify = DS0/1/1 { + Signals {ctyp/ans{anstype=ans}} + } + } +} + +``` + +MG1 to MGC: + +``` + +MEGACO/1 [124.125.125.222]:55555 +Reply = 13 { + Context = 2000 {Modify = DS0/1/1} +} + +``` + +- 11) When MG2 detects an ITU-T V.21 carrier followed by flags, it will send a message to the MGC reporting this event. At this point, the MGC is certain that the call is a fax and will initiate a switch, first on the DS0 terminations. Note that ITU-T V.21 flags are not signalled to MG1. The event causes the MGC to ask MG1 to play v21 flags to its SCN termination. + +MG2 notifying MGC of ITU-T V.21 carrier event: + +from MG2 to MGC: + +``` + +MEGACO/1 [123.123.123.4]:55555 +Transaction = 71 { + Context = 5000 { + Notify = DS0/2/2 { + ObservedEvents = 10 { + 19991212T22110031:ctyp/dtone{dtt=v21flag}} + } + } + } +} + +``` + +MGC responds. + +from MGC to MG2: + +``` + +MEGACO/1 [125.125.125.111]:55555 +Reply = 71 { + Context = 5000 {Notify = DS0/2/2} +} + +``` + +MGC sends a command to MG1 to send the ITU-T V.21 flags on its SCN termination and hand over the continuation of the session to the fax package. + +MGC to MG1: + +``` + +MEGACO/1 [123.123.123.4]:55555 +Transaction = 5{ + Context = 2000 { + Modify = DS0/1/1 { + Signals {ctyp/ans{anstype=v21flags, SignalType=TimeOut}} + Events = 2 { fax/faxconnchange} + Media{ + TerminationState + {fax/faxstate = TrainT; + } + } + } + } +} + +``` + +MG1 to MGC: + +``` + +MEGACO/1 [124.125.125.222]:55555 +Reply = 5 { + Context = 2000 {Modify = DS0/1/1} +} + +``` + +The MG must generate the v21flags signal until the ITU-T V.21 flags indication arrives in the ITU-T T.38 media stream (see step 17) and then continue until the ITU-T V.21 flags termination is indicated in the ITU-T T.38 media stream. + +- 12) At this point the SCN termination on MG2 and MG1 shall be put into fax mode (this stage is Negotiating). Only the example of MG2 is shown. Note that in the case of MG2, since the ctyp package is not mentioned in the Events Descriptor, the MG is no longer required to perform call type discrimination event notification. Also, since CNG is not mentioned in the signal descriptor, this signal is terminated. + +MGC to MG2: + +``` + +MEGACO/1 [123.123.123.4]:55555 +Transaction = 33{ + Context = 5000 { + Modify = DS0/2/2 { + Events = 12 { fax/faxconnchange} + Signals{}, + Media{ + TerminationState + {fax/faxstate = Negotiating; + } + } + } + } +} + +``` + +And MG2 responds. + +MG2 to MGC: + +``` +MEGACO/1 [125.125.125.111]:55555 +Reply = 33 { + Context = 5000 {Modify = DS0/2/2} +``` + +- 13) At this point in the call, the switch to fax continues with a request for each MG to switch to ITU-T T.38 mode. Note that the MGC is aware that the MGs support ITU-T T.38 as a result of a previous audit. If ITU-T T.38 was not available, then the audio mode may be changed to ITU-T G.711 (the details of this are out of scope). Selection among the voice, fax and data modes will have been achieved, unless some other answer tone has been detected, such as ANSam. In the event that ANSam is detected, the two MGs should be switched into a mode where they can conduct a ITU-T V.8 session to further determine the type of call (e.g., ITU-T V.34 fax, ITU-T V.90 data, text telephone, etc.). The handling of ITU-T V.34 fax calls in this environment is for further study. + +MGC to MG1: + +``` +MEGACO/1 [123.123.123.4]:55555 +Transaction = 15 { + Context = 2000 { + Modify = RTP/1 { + Media { + TerminationState {ipfax/faxstate = Negotiating; + } + Stream = 1 { + Local { +v=0 +c=IN IP4 124.124.124.222 +m=image 2222 udptl t38 +a=T38FaxRateManagement:transferredTCF +a=T38FaxUdpEC:t38UDPFEC + } ; change to ITU-T T.38 in the IP connection + } + } + } +} +``` + +- 14) Following is the response from MG1. MG1 changes one of the a= fields: The ITU-T T.38 parameter transferredTCF is changed by MG1 to localTCF. MG1 may also change the port number if it does not want to switch the use of the existing voice channel to faxport. In this example, it changes the port from 2222 to 3333. + +from MG1 to MGC: + +``` +MEGACO/1 [124.124.124.222]:55555 +Reply = 15 { + Context = 2000 {Modify = RTP/1 { + Media { + Stream = 1 { + Local { +v=0 +c=IN IP4 124.124.124.222 +m=image 3333 udptl t38 +a=T38FaxRateManagement:localTCF +a=T38FaxUdpEC:t38UDPFEC + }; the IP connection brought into fax mode + } + } + } +} +``` + +- 15) The new media information must be passed on to MG2. + +MGC to MG2: + +``` + +MEGACO/1 [123.123.123.4]:55555 +Transaction = 32 { + Context = 5000 { + Modify = RTP/2 { + Media { + TerminationState {ipfax/faxstate = Negotiating; + } + Stream = 1 { + Local { +v=0 +c=IN IP4 125.125.125.111 +m=image 1111 udpt1 t38 +a=T38FaxRateManagement:localTCF +a=T38FaxUdpEC:t38UDPFEC + }, + Remote { +v=0 +c=IN IP4 124.124.124.222 +m=image 3333 udpt1 t38 +a=T38FaxRateManagement:localTCF +a=T38FaxUdpEC:t38UDPFEC + } + } + } + } + } +} + +``` + +- 16) This is acknowledged MG2 elects NOT to change the port (it remains as 1111), and does not change any ITU-T T.38 parameters. + +#### MG2 to MGC: + +``` + +MEGACO/1 [125.125.125.111]:55555 +Reply = 32 { + Context = 5000 { + Modify = RTP/2 { + Media { + Stream = 1 { + Local { +v=0 +c=IN IP4 125.125.125.111 +m=image 1111 udpt1 t38 +a=T38FaxRateManagement:localTCF +a=T38FaxUdpEC:t38UDPFEC + } + } + } + } + } +} + +``` + +- 17) Now, MG1 needs to be given the new media information from MG2. + +#### MGC to MG1: + +``` + +MEGACO/1 [123.123.123.4]:55555 +Transaction = 15 { + Context = 2000 { + Modify = RTP/1 { + Media { + Stream = 1 { + Remote { +v=0 +c=IN IP4 125.125.125.111 +m=image 1111 udpt1 t38 +a=T38FaxRateManagement:localTCF + +``` + +``` + +a=T38FaxUdpEC:t38UDPFEC + } + } + } + } +} + +``` + +from MG1 to MGC: + +``` + +MEGACO/1 [124.124.124.222]:55555 +Reply = 15 { + Context = 2000 { Modify = RTP/1} +} + +``` + +The fax call will now proceed in ITU-T T.38 mode between the MGs. The first from MG2 message will be a ITU-T T.30 Indicator packet containing ITU-T V.21 flags. This will be generated by the continued appearance of this signal on the DS0 since the MG has no memory of previous events. + +Note that the event/faxconnchange is left on the event list of both MGs and so each state change will result in a Notify to MGC; however, MGC need not explicitly set the fax/faxstate in response since faxstate should be set implicitly by each MG as it changes state. MGC may take no action for most state changes but will likely take the appropriate action for states such as Disconnect. + +- 18) Variant: In the event that a CED or similar tone is detected by the MG2, it will always report this to the MGC. For the case where the MGC had not previously received notification of CNG detection by MG1, the group felt that it is still not clear whether a fax or data mode is applicable. However, the compressed voice codecs are not adequate in either case, so the MGC should place both MGs into a data-capable mode (i.e., ITU-T G.711) or wait for additional tones to further discriminate the call. +- 19) If the MG2 has the facility to detect an ITU-T V.21 carrier followed by flags, it will send a message to the MGC reporting this event. (It is assumed that MGs will generally not have memory of prior events, so that the notification of ITU-T V.21 and flags will be sent even if the MGC has already placed the two MGs into a fax mode.) If the MGC had not previously placed the two MGs into a fax mode, it will do so now. If the MGs are already in an ITU-T G.711 mode, the MGC shall have the choice of not requesting a mode change or of requesting that the two media gateways switch to an ITU-T T.38 mode. + +MG2 notifying MGC of ITU-T V.21 carrier event: + +from MG2 to MGC: + +``` + +MEGACO/1 [123.123.123.4]:55555 +Transaction = 4 { + Context = 5000 { + Notify = DS0/2/2 { + ObservedEvents = 10 { + 19991212T22110031:ctyp/dtone{dtt=v21flag}} + } + } + } +} + +``` + +- 20) Variant: At this point in the call, the selection among the voice, fax and data modes will have been achieved, unless some other answer tone has been detected, such as ANSam. In the event that ANSam is detected, the two MGs should be switched into a mode where they can conduct an ITU-T V.8 session to further determine the type of call (e.g., ITU-T V.34 fax, ITU-T V.90 data, text, telephone, etc.) The handling of ITU-T V.34 fax calls in this environment is for further study. + +MG notifying MG2 of an ANSam event: + +from MG2 to MGC: + +``` +MEGACO/1 [123.123.123.4]:55555 +Transaction = 4 { + Context = 5000 { + Notify = DS0/2/2 { + ObservedEvents = 10 { + 19991212T22110031:ctyp/dtone{dt=ansam}} + } + } + } +} +``` + +### **III.2.2 Fax-only call set-up between ITU-T H.248 and an ITU-T H.323 endpoint** + +This facsimile-only call flow example (see Figure III.2) describes a facsimile call that originates in the SCN and is terminated in the packet network. The packet network signalling in this example is ITU-T H.323 but other signalling protocols such as SIP can be used. The purpose of the example is to describe MG/MGC interactions. + +The assumption is made that the signalling between the signalling gateway (SGW) and MGC is based on [ITU-T Q.931]. This does not indicate that no other signalling can be used on this interface. Capabilities described here are generic line package descriptions (but could also be SDP or ITU-T H.245 messages). + +The media gateway is configured for voice and fax; however, the ITU-T H.323 endpoint is fax only, taking the calls into fax-only mode. (i.e., it is likely an ITU-T T.38 Annex B endpoint). + +![Sequence diagram showing the fax-only call set-up between ITU-T H.248 and an ITU-T H.323 endpoint. The diagram involves six lifelines: G3FE, SCN, SGW, MGC, ITU-T H.323 GW, and G3FE. The sequence of messages is as follows: 1. G3FE sends OFF HOOK to SCN. 2. SCN sends DIAL TONE to G3FE. 3. G3FE sends DIALING to SCN. 4. SCN sends IAM to SGW. 5. SGW sends Q:SETUP[H:OLC] to MGC. 6. MGC sends CREATE CONTEXT to SGW. 7. SGW sends ACK to MGC. 8. MGC sends Q:SETUP[H:OLC] to ITU-T H.323 GW. 9. ITU-T H.323 GW sends Q:CALL PROC to MGC. 10. MGC sends Q:ALERT to ITU-T H.323 GW. 11. ITU-T H.323 GW sends RINGING to G3FE. 12. G3FE sends 7-CNG to SGW. 13. SGW sends Q:ALERT to MGC. 14. MGC sends Q:CONNECT[H:OLC] to ITU-T H.323 GW. 15. ITU-T H.323 GW sends OFF HOOK to G3FE. 16. G3FE sends RINGING to SCN. 17. SCN sends 10. MODIFY to SGW. 18. SGW sends 11. CONNECT to MGC. 19. MGC sends 12. ACK to SGW. 20. A shaded bar labeled 'Fax mode' covers the next set of messages. 21. SCN sends CNG to SGW. 22. SGW sends ITU-T T.38 CNG packet to ITU-T H.323 GW. 23. ITU-T H.323 GW sends CNG to G3FE. 24. G3FE sends CED to SCN. 25. SCN sends ITU-T T.38 CED packet to ITU-T H.323 GW. 26. ITU-T H.323 GW sends CED to G3FE. 27. G3FE sends ITU-T V.21 to SCN. 28. SCN sends ITU-T T.38 ITU-T V.21 packet to ITU-T H.323 GW. 29. ITU-T H.323 GW sends ITU-T V.21 to G3FE. 30. SCN sends 13. NOTIFY to MGC.](e47d450f315d0b633906c03cc91f90ef_img.jpg) + +Sequence diagram showing the fax-only call set-up between ITU-T H.248 and an ITU-T H.323 endpoint. The diagram involves six lifelines: G3FE, SCN, SGW, MGC, ITU-T H.323 GW, and G3FE. The sequence of messages is as follows: 1. G3FE sends OFF HOOK to SCN. 2. SCN sends DIAL TONE to G3FE. 3. G3FE sends DIALING to SCN. 4. SCN sends IAM to SGW. 5. SGW sends Q:SETUP[H:OLC] to MGC. 6. MGC sends CREATE CONTEXT to SGW. 7. SGW sends ACK to MGC. 8. MGC sends Q:SETUP[H:OLC] to ITU-T H.323 GW. 9. ITU-T H.323 GW sends Q:CALL PROC to MGC. 10. MGC sends Q:ALERT to ITU-T H.323 GW. 11. ITU-T H.323 GW sends RINGING to G3FE. 12. G3FE sends 7-CNG to SGW. 13. SGW sends Q:ALERT to MGC. 14. MGC sends Q:CONNECT[H:OLC] to ITU-T H.323 GW. 15. ITU-T H.323 GW sends OFF HOOK to G3FE. 16. G3FE sends RINGING to SCN. 17. SCN sends 10. MODIFY to SGW. 18. SGW sends 11. CONNECT to MGC. 19. MGC sends 12. ACK to SGW. 20. A shaded bar labeled 'Fax mode' covers the next set of messages. 21. SCN sends CNG to SGW. 22. SGW sends ITU-T T.38 CNG packet to ITU-T H.323 GW. 23. ITU-T H.323 GW sends CNG to G3FE. 24. G3FE sends CED to SCN. 25. SCN sends ITU-T T.38 CED packet to ITU-T H.323 GW. 26. ITU-T H.323 GW sends CED to G3FE. 27. G3FE sends ITU-T V.21 to SCN. 28. SCN sends ITU-T T.38 ITU-T V.21 packet to ITU-T H.323 GW. 29. ITU-T H.323 GW sends ITU-T V.21 to G3FE. 30. SCN sends 13. NOTIFY to MGC. + +T.38(15)\_FIII.2 + +**Figure III.2 – Fax-only call set-up between ITU-T H.248 and an ITU-T H.323 endpoint** + +- 1) The SGW sends a *Setup* message to the MGC after receiving an IAM from a SCN switch. From the Setup message, the MGC may infer which circuit on which MG is involved and where to terminate the call. How the MGC does this is outside the scope of this Recommendation. +- 2) The MGC creates a Context for the call. The Context contains two terminations: one for the SCN side and one for the packet side. Also, in order for the MGC to infer whether both gateways support the ITU-T T.38 autonomous transitioning method or the ITU-T T.38 MGC transitioning method, the MGC instructs MG1 to respond with the values of both its + +audio RTP/AVP capabilities and its image/t38 capabilities. Note that in the LocalControl descriptor, ReserveGroup = True to ask the MG to take both audio and image media descriptors (in addition, an MGC may include ReserveValue = false to ask for the most preferred codec. However, if omitted, an MG by default must set this value to false in accordance with [ITU-T H.248]): + +MGC to MG: + +``` +MEGACO/1 [123.123.123.4]:55555 +Transaction = 11 { + Context = $ { + Add = DS0/1/1 { + Events = 1 { ctyp/dtone, fax/faxconnchange, al/of} + }, ; the SCN side termination listening for call type indicating tones + Add = $ { + Media { + Stream = 1 { + LocalControl { Mode = ReceiveOnly, ReserveGroup = True }, + Local { +v=0 +c=IN IP4 $ +m=audio $ RTP/AVP 18 0 +v=0 +c=IN IP4 $ +m=image $ udptl t38 + } ; the IP side term. showing capability of RTP audio with PT 0 (G.711 + PCMU) and 18 (G.729). + } +} +} +} +} +``` + +- 3) The MG accepts the Context creation and fills in the unknown (\$) parameters. MG1 does not support the ITU-T T.38 autonomous transitioning method; hence, it omits the image media line in the response: + +``` +MEGACO/1 [124.124.124.222]:55555 +Reply = 11 { + Context = 2000 { + Add = DS0/1/1,; the SCN termination is accepted + Add = RTP/1 { + Media { + Stream = 1 { + Local { +v=0 +c=IN IP4 124.124.124.222 +m=audio 2222 RTP/AVP 18 + } ; the IP RTP termination is accepted with audio payload type 18. + } +} +} +} +} +``` + +This shows how the MG reports to the MGC what parameters it filled in. + +- 4) The MGC sends a *Setup* message to the destination endpoint, here assumed to be an ITU-T H.323 endpoint (terminal, GW, etc.). It indicates in the fastStart element that either the capability to use UDP or TCP may be used for the ITU-T T.38 facsimile stream. + +- 5) The ITU-T H.323 endpoint sends a *CallProceeding* message followed by an *Alerting* message back to the MGC, informing it of the mode to be used (assume UDP for both directions) and the transport address; followed by an *Alerting* message, indicating that it is ringing the G3FE. +- 6) The MGC sends a Modify command to the MG to set the mode and remote termination description on the packet side: + +MGC to MG: + +``` +MEGACO/1 [123.123.123.4]:55555 +Transaction = 1450 { + Context = 2000 { + Modify = RTP/1 { + Events= 3 {fax/faxconnchange}, + Media { + TerminationState { + fax/faxstate=Prepare; + ipfax/ipftrpt=T38UDPTL; + } + Stream = 1 { + Local { +v=0 +c=IN IP4 124.124.124.222 +m=image 2222 udptl t38 +a=T38FaxRateManagement:transferredTCF +a=T38FaxUdpEC:t38UDPFEC + } ; modify media stream 1 to use image media , udptl transport for T38 + } + } + } + } +} +``` + +- 7) The MG accepts the Modify commands. At about this time, the MG may detect a CNG on the line; thus notifies the MGC, which acknowledges. Since there is no way to initiate a playing of CNG on the ITU-T H.323 endpoint, the MGC will wait until the connection is open. Note that the MGC may not receive a CNG before the ITU-T H.323 *Connect*: + +from MG to MGC: + +``` +MEGACO/1 [124.124.124.222]:55555 +Reply = 1450 { + Context = 2000 {Modify = RTP/1 { + Media { + Stream = 1 { + Local { +v=0 +c=IN IP4 124.124.124.222 +m=image 3333 udptl t38 +a=T38FaxRateManagement:transferredTCF +a=T38FaxUdpEC:t38UDPFEC + } ; The fax udptl/t38 transport channel is accepted on the IP session + } + } + } +} +``` + +``` +MEGACO/1 [124.124.124.222]:55555 +Transaction = 50 { + Context = 2000 { +Notify = DSO/1/1 { + ObservedEvents = 1 { + 19991212T22110001:ctyp/dtone{dtt=cng} + } +} +``` + +``` + + } +} + +``` + +from MGC to MG: + +``` + +MEGACO/1 [123.123.123.4]:55555 +Reply = 50 { + Context = 2000 {Notify = DS0/1/1} +} + +``` + +- 8) The MGC sends an *Alerting* message to the SGW. +- 9) The called endpoint, at some instance, sends a *Connect* message to the MGC once the G3FE goes off-hook. Note that this message only contains facsimile capabilities and does not include an ITU-T H.245 port +- 10) A Modify command to the MG to change the mode of the SCN side termination to SendRecv and to fax mode. Also, the indication of fax capabilities to be set up on the ITU-T T.38 is also included in this command (this information was included in the *Connect* from the ITU-T H.323 endpoint): + +MGC to MG: + +``` + +MEGACO/1 [123.123.123.4]:55555 +Transaction = 30 { + Context = $ { + Modify = DS0/1/1 { + Media { + TerminationState { fax/faxstate = Prepare}, + Stream = 1 { + LocalControl { Mode=SendReceive } } }, + Events = 10 {al/of, ctyp/dtone, fax/faxconnchange }, + Signals = {al/ri } + } ; modify SCN termination to reflect that we are connected through + Modify = RTP/1 { + Media { + TerminationState { ipfax/faxstate = Prepare, + ipfax/ipftrpt=T38UDPTL }, + Stream = 1 { + Local { +v=0 +c=IN IP4 124.124.124.222 +m=image 2222 udptl t38 +a=T38FaxRateManagement:transferredTCF +a=T38FaxUdpEC:t38UDPFEC + } ; modify media stream 1 to use image media , udptl transport for T38 + LocalControl { Mode = SendReceive + } + } + }, + Events = 2 { ipfax/faxconnchnng } + } +} +} + +``` + +- 11) The MGC sends a *Connect* message to the SGW to indicate the call is connected. +- 12) The MG accepts the Modify command that was sent to it earlier (see point 10). + +from MG to MGC: + +``` + +MEGACO/1 [124.124.124.222]:55555 +Reply = 14 { + Context = 2000 { + Modify = RTP/1 { + Media { + Stream = 1 { + Local { + +``` + +``` + +v=0 +c=IN IP4 124.124.124.222 +m=image 3333 udpt1 t38 +a=T38FaxRateManagement:transferredTCF +a=T38FaxUdpEC:t38UDPFEC + }; The fax udpt1/t38 transport channel is accepted on the IP session + } + }, + Modify = DS0/1/1 + }; The modify is accepted on the DS0 session +} + +``` + +At this point, the call proceeds in ITU-T T.38 mode between the gateways. Likely the originating G3FE is still sending CNG so this will be sent first, followed by CED from the destination G3FE. + +- 13) Note that since the MG has been asked to indicate when the fax connection state changes, after the ITU-T V.21 flags packet is received, the MG notifies the MGC of this event. + +from MG to MGC: + +``` + +MEGACO/1 [124.124.124.222]:55555 +Transaction = 60 { + Context = 2000 { + Notify = RTP/1 { + ObservedEvents = 1 { + 19991212T22110001:ipfax/faxconnchange{faxconnchnng=Negotiating } + } + } + } +} + +``` + +from MGC to MG: + +``` + +MEGACO/1 [123.123.123.4]:55555 +Reply = 60 { + Context = 2000 {Notify = RTP/1} +} + +``` + +### III.2.3 Voice to fax call set-up with ITU-T H.248 endpoints that support the ITU-T T.38 autonomous transitioning method + +This call flow example (see Figure III.3) describes a voice call that originates and terminates in the SCN and is transported through the packet network. The packet network signalling in this example is not specified but any signalling protocols such as ITU-T H.323 or SIP can be used. The purpose of the example is to describe MG/MGC interactions when operating in the ITU-T T.38 autonomous transitioning mode including indication of support of the ITU-T T.38 autonomous transitioning mode, the detection of fax and switching from voice to fax. Note that, in contrast to the switchover to ITU-T T.38 fax mode under control of the MGC (i.e., the ITU-T T.38 MGC transitioning method), the fax package defined in Annex F of [ITU-T H.248.1] does not need to be supported by the MGs. + +![Sequence diagram showing the voice to fax call set-up process between G3FE1, MG1, MGC, MG2, and G3FE2. The process is divided into three main sections: initial setup, Voice mode, and ITU-T T.38 mode. The diagram includes messages like 1. AUDIT, 1. REPLY, 2. OFF HOOK, 2. DIAL TONE, 2. DIALLING, 2. SETUP (SCTP), 3. CREATE CONTEXT, 4. ACK, 5. CREATE CONTEXT, 6. ACK, 7. Modify, 8. ACK Response, 9. CNG, 9. ITU-T T.38 CNG indicator packet, 10a. DCN, 10a. ITU-T T.38 package with DCN, 10d. Modify (optional), and 10d. ACK. A dashed line separates the initial setup from the Voice mode section. A solid line separates the Voice mode section from the ITU-T T.38 mode section. A solid line separates the ITU-T T.38 mode section from the final Voice mode section.](e492fe1061d82aa76cbf7114f57eb90c_img.jpg) + +``` + +sequenceDiagram + participant G3FE1 + participant MG1 + participant MGC + participant MG2 + participant G3FE2 + + MG1->>MGC: 1. AUDIT + MGC->>MG1: 1. REPLY + MG1->>MG2: 1. AUDIT + MG2->>MG1: 1. REPLY + + Note over G3FE1, MG1: 2. OFF HOOK + MG1->>G3FE1: 2. DIAL TONE + MG1->>G3FE1: 2. DIALLING + + Note over MG1, MGC: 2. SETUP (SCTP) + MG1->>MGC: 2. SETUP (SCTP) + + Note over MG1, MGC: 3. CREATE CONTEXT + MG1->>MGC: 3. CREATE CONTEXT + MGC->>MG1: 4. ACK + + Note over MG1, MG2: 5. CREATE CONTEXT + MG1->>MG2: 5. CREATE CONTEXT + MG2->>MG1: 6. ACK + + Note over G3FE1, MG1, MGC, MG2, G3FE2: Voice mode + + Note over MG1, MGC: 7. Modify + MG1->>MGC: 7. Modify + MGC->>MG1: 8. ACK Response + + Note over G3FE1, MG1: 9. CNG + MG1->>MGC: 9. ITU-T T.38 CNG indicator packet + MG1->>MG2: 9. CNG + MG2->>G3FE2: 9. CNG + + Note over G3FE1, MG1, MGC, MG2, G3FE2: ITU-T T.38 mode + + Note over G3FE1, MG1: 10a. DCN + MG1->>MGC: 10a. ITU-T T.38 package with DCN + MG2->>MG1: 10a. DCN + + Note over MG1, MGC: 10d. Modify (optional) + MG1->>MGC: 10d. Modify (optional) + MGC->>MG1: 10d. ACK + + Note over MG1, MG2: 10d. Modify (optional) + MG1->>MG2: 10d. Modify (optional) + MG2->>MG1: 10d. ACK + + Note over G3FE1, MG1, MGC, MG2, G3FE2: Voice mode + +``` + +Sequence diagram showing the voice to fax call set-up process between G3FE1, MG1, MGC, MG2, and G3FE2. The process is divided into three main sections: initial setup, Voice mode, and ITU-T T.38 mode. The diagram includes messages like 1. AUDIT, 1. REPLY, 2. OFF HOOK, 2. DIAL TONE, 2. DIALLING, 2. SETUP (SCTP), 3. CREATE CONTEXT, 4. ACK, 5. CREATE CONTEXT, 6. ACK, 7. Modify, 8. ACK Response, 9. CNG, 9. ITU-T T.38 CNG indicator packet, 10a. DCN, 10a. ITU-T T.38 package with DCN, 10d. Modify (optional), and 10d. ACK. A dashed line separates the initial setup from the Voice mode section. A solid line separates the Voice mode section from the ITU-T T.38 mode section. A solid line separates the ITU-T T.38 mode section from the final Voice mode section. + +T.38(15)\_FIII.3 + +**Figure III.3 – Voice to fax call set-up with ITU-T H.248 endpoints that support autonomous transition between VoIP and FoIP** + +The sequence of events is as follows: + +- 1) At some point before a call, the media gateway controller will have issued an audit capabilities command to the media gateways under its control and will know what the voice and fax capabilities are for each gateway. In the scenarios below, if both media gateways support ITU-T T.38, then this is the preferred mode for IP fax operations. In the event that one or both media gateways do not support ITU-T T.38, then the fax call may proceed over the IP voice channel. However, since ITU-T T.30 facsimile may fail over a compressed voice codec, it would be preferable to use an ITU-T G.711 codec for communication between the media gateways. 'W-' is used to indicate that a wild-carded answer with a union of information on all terminations on the MG is requested, not an audit of each termination + +on the MG. Note that MG1 indicates to the MGC that it supports ITU-T T.38; however, the audit shall not be used to indicate support of the ITU-T T.38 autonomous transitioning method or the ITU-T T.38 MGC transitioning method (as described in clause E.2.2). This shall be done on a call-by-call basis during the Add ephemeral (see point 3 below). + +The MGC audits MG1. + +MGC to MG1: + +``` +MEGACO/1 [123.123.123.4]:55555 +Transaction = 9 { + Context = - {W-AuditValue = * {Audit{Packages}}} +``` + +MG1 replies. MG1 to MGC: + +``` +MEGACO/1 [125.125.125.111]:55555 +Reply = 9 { + Context = - { + AuditValue = * { + Packages {al, rtp, ipfax, fax, ctyp, cg} + ; al = analog line pkg, rtp = rtp pkg, ipfax = ITU-T T.38 fax pkg, fax = fax pkg + ; ftmd = fax/textphone/modem tones detection pkg + ; ctyp = Call Type Discrimination package) + ; cg =call progress tones generator pkg + } + } +} +``` + +MGC to MG1: + +``` +MEGACO/1 [123.123.123.4]:55555 +Transaction = 10 { + Context = - {W-AuditCapability = * {Audit{Media }}} +``` + +MG1 replies. MG1 to MGC: + +``` +MEGACO/1 [125.125.125.111]:55555 +Reply = 10 { + Context = - { + AuditCapability = * { + Media { + Stream = 1 { + Local { + +v=0 +c=IN IP4 $ +m=audio $ RTP/AVP 0 18 +v=0 +c=IN IP4 $ +m=image $ udpt1 t38 + } ; RTP profile for G.711 is 0, G.729 is 18, t38 is ITU-T T.38 + }, + } + } +} +``` + +A similar exchange happens between the MGC and MG2. + +- 2) The end user decides to send a fax from device F1 and enters the phone number. The fax device gets dial tone and then dials the phone number. As a result, the central office within the local SCN loop sends an SS7 message to the signalling gateway (SG). The SG sends a *Setup* message to the MGC after receiving this IAM from a SCN switch that conveys the + +called and calling phone numbers. Sigtran's SCTP carries the SS7 signalling from the SG to the MGC. + +- 3) From the IAM message, the MGC may infer which circuit on which MG is involved and where to terminate the call. How the MGC does this is outside the scope of this Recommendation. The endpoints are found by the media gateway controller (MGC) and it sets up the audio channel between the two media gateways and instructs the SS7 facility of the receiving CO to connect to the end phone destination, which results in the generation of ringing. So, to start, the controller determines that a connection needs to be made from MG1 to MG2. The MGC creates a Context for the call. A TDM termination DS0/1/1, an audio/RTP termination and an image/t38 termination are added to a new context in MG1. Mode is ReceiveOnly since Remote descriptor values are not yet specified. Preferred codecs are in the MGC's preferred order of choice. The MGC sets to CHOOSE (i.e., \$) the fields in the SDP in the Local descriptor that the MG will set itself. Also, in order for the MGC to infer whether both gateways support the ITU-T T.38 autonomous transitioning method or the ITU-T T.38 MGC transitioning method, the MGC instructs MG1 to respond with the values of both its audio RTP/AVP capabilities and its image/t38 capabilities. Note that this is achieved by including in the LocalControl descriptor "ReserveGroup=True" to ask the MG to reserve resources for both audio and image media descriptors. In addition, "ReserveValue=True" to ask the MG to reserve resources for all the possible codecs offered in the media descriptor (alternatively an MGC may include ReserveValue=false to ask for the most preferred codec; however, if omitted a MG by default must set this value to false). + +MGC to MG1: + +``` +MEGACO/1 [123.123.123.4]:55555 +Transaction = 11 { + Context = $ { + Add = DS0/1/1 { + Media { + Stream = 1 { + } + } + } + + Add = $ { + Media { + Stream = 1 { + LocalControl { Mode = ReceiveOnly, ReserveGroup=True, ReserveValue=True }, + Local { + +v=0 +c=IN IP4 $ +m=audio $ RTP/AVP 18 0 +v=0 +c=IN IP4 $ +m=image $ udpt1 t38 + + }; IP termination for audio + } + } + } + } +} +``` + +- 4) MG1 acknowledges the new termination and fills in the local IP address and UDP port. It also supports and can reserve resources for all the codecs offered in the list within the media descriptor of the SDP block in local, thus leaving the final choice of codec for the remote gateway. MG1 sets the RTP port to 2222. Because the MG supports the ITU-T T.38 autonomous transitioning method for transitioning between VoIP and FoIP; it also sets the ITU-T T.38 port to 4444 and includes the supported ITU-T T.38 capabilities. If the MG did not support autonomous transitioning between VoIP and FoIP; it would set the ITU-T T.38 port to 0 or omit the image media descriptor line altogether, and would proceed as indicated in clause III.2.1. + +``` +MEGACO/1 [124.124.124.222]:55555 +Reply = 11 { + Context = 2000 { + Add = DS0/1/1, ; SCN termination added + Add = RTP/1 { + Media { + Stream = 1 { + Local { +v=0 +c=IN IP4 124.124.124.222 +m=audio 2222 RTP/AVP 18 0 ; MG1 can reserve resources for both codecs +v=0 +c=IN IP4 124.124.124.222 +m=image 4444 udpt1 t38 +a=T38FaxRateManagement:transferredTCF +a=T38FaxUdpEC:t38UDPFEC + + } ; IP termination added + } + } + } + } +} +``` + +- 5) The MGC will now associate DS0/2/2 with a new Context on MG2, and establish an RTP Stream (i.e., RTP/2 will be assigned) and ITU-T T.38 stream SendReceive connections through to the originating user, User 1. Also, because MG1 supports the ITU-T T.38 autonomous transitioning method, the MGC needs to find out whether the MG2 supports the ITU-T T.38 autonomous transitioning method, for which the MGC will ask MG2 by including an audio media descriptor and an image media descriptor with the ports set to \$ in the Add ephemeral of the create context message and including, in the LocalControl descriptor, the property "ReserveGroup=True" to ask the MG to take both audio and image media descriptors, as well as indicating that the remote MG supports the ITU-T T.38 autonomous transitioning method. Note that, in addition, the MGC includes ReserveValue=false to ask for the most preferred Code. + +MGC to MG2: + +``` +MEGACO/1 [123.123.123.4]:55555 +Transaction = 30 { + Context = $ { + Add = DS0/2/2 { + Media { + Stream = 1 { + LocalControl {Mode = SendReceive, ReserveGroup=True, ReserveValue=false } + }, + }, + }, + Add = $ { + Media { + Stream = 1 { + LocalControl {Mode = SendReceive }, + +``` + +``` + + Local { +v=0 +c=IN IP4 $ +m=audio $ RTP/AVP 18 0 +v=0 +c=IN IP4 $ +m=image $ udpt1 t38 + }, + Remote { +v=0 +c=IN IP4 124.124.124.222 +m=audio 2222 RTP/AVP 18 0 +v=0 +c=IN IP4 124.124.124.222 +m=image 4444 udpt1 t38 +a=T38FaxRateManagement:transferredTCF +a=T38FaxUdpEC:t38UDPFEC + + } ; RTP profile for G.711 is 0 + } +} +} +} +} + +``` + +- 6) This is acknowledged. Also, because MG2 supports the ITU-T T.38 Autonomous Transitioning method for transitioning between VoIP and FoIP, it includes in the SDP response both an audio and an image media descriptor with valid port numbers. The RTP stream port number is different from the Megaco of ITU-T H.248 control port number. In this case, it is 1111 (in the SDP). The ITU-T T.38 stream port number is different from the Megaco/ITU-T H.248 control port number. In this case, it is 5555 (in the SDP). Also, from the remote SDP, MG2 knows that it shall transition between VoIP and FoIP using the ITU-T T.38 autonomous transitioning method. If the remote SDP did not have both the audio and an image media descriptor, MG2 would have defaulted to using the ITU-T T.38 MGC transitioning method for transitioning from an audio/RTP connection to an image/t38 connection and the procedures in point 7 of clause III.2.1 follow. Also, MG2 chooses ITU-T G.729 (payload type = 18) as the voice codec to use. + +#### MG2 to MGC: + +``` + +MEGACO/1 [125.125.125.111]:55555 +Reply = 30 { + Context = 5000 { + Add = DS0/2/2, + Add = RTP/2 { + Media { + Stream = 1 { + Local { +v=0 +c=IN IP4 125.125.125.111 +m=audio 1111 RTP/AVP 18 +v=0 +c=IN IP4 125.125.125.111 +m=image 5555 udpt1 t38 +a=T38FaxRateManagement:transferredTCF +a=T38FaxUdpEC:t38UDPFEC + + } + } + } + } + } +} +} +} + +``` + +- 7) The above IPAddr and UDPport and voice codec need to be given to MG1 now. As well as indicating that MG2 supports the ITU-T T.38 autonomous transitioning method for transitioning between VoIP & FoIP. Also apply ringing tone ringback to the DS0/1/1 termination and change it to a SendReceive. + +MGC to MG1: + +``` +MEGACO/1 [123.123.123.4]:55555 +Transaction = 12 { + Context = 2000 { + Modify = DS0/1/1 { + + Signals {cg/rt} }, ;apply ringing tone + Modify = RTP/1 { + Media { + Stream = 1 { + LocalControl {Mode = SendReceive, ReserveGroup=True }, + Remote { + +v=0 +c=IN IP4 125.125.125.111 +m=audio 1111 RTP/AVP 18 +v=0 +c=IN IP4 125.125.125.111 +m=image 5555 udpt1 t38 +a=T38FaxRateManagement:transferredTCF +a=T38FaxUdpEC:t38UDPFEC + + } + } + } + } + } + } +} +``` + +from MG1 to MGC: + +``` +MEGACO/1 [124.124.124.222]:55555 +Reply = 12 { + Context = 2000 {Modify = DS0/1/1, Modify = RTP/1} +} +``` + +- 8) MG1 acknowledges, and shall use the ITU-T T.38 autonomous transitioning method for transitioning from audio/RTP connection to an image/t38 connection. +- 9) The calling fax machine typically will start to generate CNG calling tones. It is envisioned that the first media gateway (MG1) will detect the CNG tone event and will determine that a facsimile call is commencing. Hence, MG1 will switch to image/t38 mode, mute its audio/RTP connection and transmit (via its image/t38 connection) to MG2 the ITU-T T.38 CNG indicator packet. MG2, on receipt of the ITU-T T.38 CNG indicator packet, will transition to image/t38 mode. This may be implemented such that receipt at its ITU-T T.38 UDP port of a valid IP/UDP packet whose source IP address corresponds to that of MG1 can be assumed to be a ITU-T T.38 packet causing a transition to ITU-T T.38. Hence, on transition to image/t38 mode, this packet will be decoded and analysed to be of type CNG, thus playing out the appropriate CNG tone. In order to avoid any unwanted UDP packet arriving at the ITU-T T.38 UDP port, this port should be activated only if the ITU-T T.38 autonomous transitioning method (and ITU-T T.38 capabilities) was successfully negotiated before the call. From here on, both MGs will operate in accordance with this Recommendation. If there were no CNG tone, then MG1 would transition the ITU-T T.38 on detection of a sufficient number of ITU-T T.30 preamble flags (also known as the + +ITU-T V.21 preamble flags) and send the corresponding ITU-T T.38 ITU-T V.21 preamble indicator packet. + +Alternatively: If IETF RFC 4733 telephone events are supported by both MGs (i.e., methods 2 and 3 described in clause E.2.2.2.2.1), and indicated either via SDP exchange or other mechanisms beyond the scope of this Recommendation, then a MG1 may choose to send the corresponding CNG, CED and ITU-T V.21 preamble across the packet network as described in clause E.2.2.2.2.1 and transition to ITU-T T.38 only on detection of a sufficient number of ITU-T V.21 preamble flags. + +- 10) The MGs shall revert back to the audio/RTP connection (VoIP) based on detection of any of the following: + - a) Detection of an ITU-T T.30 DCN message; + - b) Detection of bidirectional silence. It is recommended to detect transition back to voice mode on detection of more than 7 s of bidirectional silence to allow for the ITU-T T.30 T2 timers (within the G3FEs) to time out; + - c) Detection of voice; + - d) Reception of a Modify command in which only an audio media descriptor is present. + +### **III.2.4 Voice to fax call set-up between ITU-T H.248 and ITU-T H.323 endpoints that support the ITU-T T.38 autonomous transitioning method** + +This facsimile-only call flow example (see Figure III.4) describes a facsimile call that originates in the SCN and is terminated in the packet network. The packet network signalling in this example is clause D.3 of [ITU-T H.323], but other signalling protocols such as SIP can be used. The purpose of the example is to describe MG/MGC interactions. + +The assumption is made that the signalling between the signalling gateway (SGW) and MGC is based on [ITU-T Q.931]. This does not indicate that no other signalling can be used on this interface. Capabilities described here are generic line package descriptions (but could also be SDP or ITU-T H.245 messages). + +The media gateway and the ITU-T H.323 endpoint are configured for voice and fax. The purpose of the example is to describe MG/MGC and ITU-T H.323-endpoint/MGC interactions when operating in the ITU-T T.38 autonomous mode including indication to use the ITU-T T.38 autonomous mode, the detection of fax and switching from voice to fax. + +![Sequence diagram showing the voice to fax call set-up process between G3FE, SCN, SGW, MGC, and ITU-T H.323 GW. The process includes steps for off-hook, dialing, IAM, Q:SETUP, CREATE CONTEXT, ACK, Q:CALL PROC, Q:ALERTING, RINGING, Q:CONNECT, and various signaling packets like CNG, CED, and ITU-T T.38 packets.](8181865f1fd5e629dbe12ed89d22dc83_img.jpg) + +``` + +sequenceDiagram + participant G3FE1 as G3FE + participant SCN as SCN + participant SGW1 as SGW + participant MG1 as MG + participant MGC as MGC + participant SGW2 as SGW + participant MG2 as MG + participant SGW3 as SGW + participant MG3 as MG + participant ITU_T_H323_GW as ITU-T H.323 GW + participant G3FE2 as G3FE + + G3FE1->>SCN: 1. OFF HOOK + SCN->>G3FE1: 1. DIAL TONE + SCN->>G3FE1: 1. DIALLING + SCN->>SGW1: 1. IAM + SGW1->>MGC: 1. Q:SETUP + MGC->>MG1: 3. CREATE CONTEXT + MG1->>MGC: 4. ACK + MGC->>ITU_T_H323_GW: 5. SETUP[fastStart-ITU-T G.711 PCMU, ITU-T T.38] + ITU_T_H323_GW->>MGC: 6. Q:CALL PROC + MGC->>ITU_T_H323_GW: 7. Q:ALERTING [fastStart-ITU-T G.711 PCMU, ITU-T T.38] + ITU_T_H323_GW->>G3FE2: RINGING + SGW2->>G3FE1: RINGING + ITU_T_H323_GW->>MG2: 9. Q:CONNECT[H:OLC] + MG2->>SGW3: 10. MODIFY + SGW3->>MG3: 11. Q:CONNECT + MG3->>MGC: 12. ACK + MGC->>SGW1: Voice mode + SGW1->>SGW2: CNG + MGC->>ITU_T_H323_GW: Fax mode + ITU_T_H323_GW->>G3FE2: CNG + ITU_T_H323_GW->>G3FE2: CED + ITU_T_H323_GW->>G3FE2: ITU-T V.21 + ITU_T_H323_GW->>SGW2: ITU-T T.38 CNG packet + ITU_T_H323_GW->>SGW2: ITU-T T.38 CED packet + ITU_T_H323_GW->>SGW2: ITU-T T.38 ITU-T V.21 packet + SGW2->>G3FE1: CED + G3FE1->>SGW1: ITU-T V.21 + +``` + +Sequence diagram showing the voice to fax call set-up process between G3FE, SCN, SGW, MGC, and ITU-T H.323 GW. The process includes steps for off-hook, dialing, IAM, Q:SETUP, CREATE CONTEXT, ACK, Q:CALL PROC, Q:ALERTING, RINGING, Q:CONNECT, and various signaling packets like CNG, CED, and ITU-T T.38 packets. + +T.38(15)\_FIII.4 + +**Figure III.4 – Voice to fax call set-up with ITU-T H.248 and ITU-T H.323 endpoints that support ITU-T T.38 Autonomous Transition between VoIP and FoIP** + +- 1) The SGW sends a *Setup* message to the MGC after receiving an IAM from a SCN switch. +- 2) From the IAM message, the MGC may infer which circuit on which MG is involved and where to terminate the call. How the MGC does this is outside the scope of this Recommendation. +- 3) The MGC creates a Context for the call. The Context contains two terminations: one for the SCN side and one for the packet side. The MGC sets to CHOOSE (i.e., \$) the fields in the + +SDP in the Local descriptor that the MG will set itself. Also, in order for the MGC to infer whether MG1 supports the ITU-T T.38 autonomous transitioning method or the ITU-T T.38 MGC transitioning method, the MGC instructs MG1 to respond with the values of both its audio RTP/AVP capabilities and its image/t38 capabilities. Note that this is achieved by including in the LocalControl descriptor "ReserveGroup=True" to ask the MG to reserve resources for both audio and image media descriptors. In addition, the MGC may include ReserveValue=false to ask for the most preferred codec; however, if omitted, an MG by default should set this value to false: + +MGC to MG: + +``` +MEGACO/1 [123.123.123.4]:55555 +Transaction = 11 { + Context = $ { + Add = DS0/1/1 { + Events = 1 { ctyp/dtone, fax/faxconnchange, al/of} + }, ; the SCN side termination listening for call type indicating tones + Add = $ { + Media { + Stream = 1 { + LocalControl { Mode = ReceiveOnly, ReserveGroup=True }, + Local { +v=0 +c=IN IP4 $ +m=audio $ RTP/AVP 18 0 +v=0 +c=IN IP4 $ +m=image $ udptl t38 + } ; the IP side termination showing capability of RTP audio with PT 0 +and 18. + } + } + } + } +} +``` + +- 4) The MG accepts the Context creation and fills in the unknown (\$) parameters. The MG supports the ITU-T T.38 autonomous transitioning method; hence, it includes the image media line with an appropriate port number in the response and selects [ITU-T G.729] as the preferred codec: + +``` +MEGACO/1 [124.124.124.222]:55555 +Reply = 11 { + Context = 2000 { + Add = DS0/1/1,; the SCN termination is accepted + Add = RTP/1 { + Media { + Stream = 1 { + Local { +v=0 +c=IN IP4 124.124.124.222 +m=audio 2222 RTP/AVP 18 +v=0 +c=IN IP4 124.124.124.222 +m=image 5555 udptl t38 + } ; the IP RTP termination is accepted with audio payload type 0. Also, +the MG indicates that it supports the ITU-T T.38 Autonomous Transitioning method for +transitioning between VoIP and FoIP. + } + } + } + } +} +``` + +This shows how the MG reports to the MGC what parameters it filled in. + +- 5) The MGC sends a *Setup* message to the destination endpoint, here assumed to be an ITU-T H.323 endpoint (terminal, GW, etc.). Also, because it knows that the MG supports the ITU-T T.38 autonomous transitioning method, it indicates this in the fastStart element by the capability of simultaneous support of at least one audio codec and of receiving and transmitting ITU-T T.38 FoIP. +- 6) The ITU-T H.323 endpoint sends a *CallProceeding* message followed by an *Alerting* message with fastStart back to the MGC, informing it that it supports the ITU-T T.38 autonomous transitioning method by indicating its capability of simultaneous support of at least one audio codec and of receiving and transmitting ITU-T T.38 FoIP. +- 7) The MGC sends an *Alerting* message to the SGW. +- 8) The MGC sends a Modify command to the MG to set the mode and remote termination description on the packet side. +- 9) The called endpoint at some instance sends a *Connect* message to the MGC once the G3FE goes off-hook. Note that this message contains both the audio and facsimile capabilities and does not include an ITU-T H.245 port. +- 10) A Modify command is sent to the MG to change the mode of the SCN side termination to SendRecv. The remote endpoints audio and fax capabilities are also included in this command (this information was included in the *Connect* from the ITU-T H.323 endpoint). This also indicates that the remote endpoint supports the ITU-T T.38 autonomous transitioning method and that the call shall initially be set up as a voice call. + +MGC to MG: + +``` +MEGACO/1 [123.123.123.4]:55555 +Transaction = 30 { + Context = $ { + Modify = DS0/1/1 { + Media { + TerminationState { fax/faxstate = Prepare}, + Stream = 1 { + LocalControl { ReserveGroup=True } } }, + Events = 10 {al/of, fax/faxconnchange },; the MGC requests the MG to send it +an event when it transitions to ITU-T T.38. + Signals = {al/ri } + } ; modify SCN termination to reflect that we are connected through + Modify = RTP/1 { + Media { + TerminationState {ipfax/faxstate=Prepare, + ipfax/ipftrpt=T38UDPTL }, + Stream = 1 { + Local { +v=0 +c=IN IP4 124.124.124.222 +m=audio 1111 RTP/AVP 18 +v=0 +c=IN IP4 124.124.124.222 +m=image 2222 udpt1 t38 +a=T38FaxRateManagement:transferredTCF +a=T38FaxUdpEC:t38UDPFEC + } ; modify media stream 1 to use image media, udpt1 transport for T38 + LocalControl { Mode = SendReceive + } + } + }, + Events = 2 { ipfax/faxconnchnng } + } + } +} +``` + +- 11) The MGC sends a *Connect* message to the SGW to indicate the call is connected. +- 12) The MG accepts the Modify commands: + +from MG to MGC: + +``` +MEGACO/1 [124.124.124.222]:55555 +Reply = 14 { + Context = 2000 { + Modify = RTP/1 { + Media { + Stream = 1 { + Local { +v=0 +c=IN IP4 124.124.124.222 +m=audio 2222 RTP/AVP 18 +v=0 +c=IN IP4 124.124.124.222 +m=image 3333 udpt1 t38 +a=T38FaxRateManagement:transferredTCF +a=T38FaxUdpEC:t38UDPEEC + }; The fax udpt1/t38 transport channel is accepted on the IP session and the +T.38 Autonomous Transitioning method shall be used for transitioning between VoIP +and FoIP + } + } + }, + Modify = DS0/1/1 + }; The modify is accepted on the DS0 session + } +} +``` + +At this point, the call proceeds in voice mode between the gateways. The MGC knows from the responses from both gateways that the ITU-T T.38 autonomous transitioning method shall be used by both gateways for transitioning between VoIP and FoIP. Likely, the originating G3FE would send a CNG at which point the originating gateway will mute its audio/RTP port and transition to FoIP mode and send over the IP network the corresponding ITU-T T.38/T.30\_Indicator (CNG) packet. If no CNG tone was sent or detected, then the MGs would use the ITU-T V.21 preamble as the transitioning criteria. Because the destination gateway received the UDP packet at its UDP port that has been assigned for ITU-T T.38, it assumes that it is an ITU-T T.38 packet and that it must transition to ITU-T T.38 mode. From here on, both gateways will operate in accordance with this Recommendation. + +Alternatively: If IETF RFC 4733 telephone events are supported by both MGs (i.e., methods 2 and 3 described in clause E.2.2.2.2.1), and indicated either via SDP exchange or other mechanisms beyond the scope of this Recommendation, then a MG1 may choose to send the corresponding CNG, CED and ITU-T V.21 preamble across the packet network as described in clause E.2.2.2.2.1 and transition to ITU-T T.38 only on detection of a sufficient number of ITU-T V.21 preamble flags. + +The gateways shall revert back to the audio/RTP connection (VoIP) based on detection of any of the following: + +- Detection of an ITU-T T.30 DCN message; +- Detection of bidirectional silence. It is recommended to detect transition back to voice mode on detection of more than 7 s of bidirectional silence to allow for the ITU-T T.30 T2 timers (within the G3FEs) to timeout. + +# Appendix IV + +## ITU-T V.34 session examples + +(This appendix does not form an integral part of this Recommendation.) + +## IV.1 ITU-T V.34 session examples + +This clause contains several examples of signal flow in an ITU-T V.34 half-duplex fax session. In the diagrams, the labels F1, G1, G2 and F2 are used as shorthand for emitting G3FE, emitting gateway, receiving gateway and receiving G3FE, respectively. + +![Sequence diagram showing ITU-T V.8 signalling between F1, G1, G2, and F2.](35f0cb888f4aa1b5fd01738a3ea3f0c1_img.jpg) + +The diagram illustrates the ITU-T V.8 signalling sequence between four entities: F1 (emitting G3FE), G1 (emitting gateway), G2 (receiving gateway), and F2 (receiving G3FE). The sequence is as follows: + +- Initial Setup:** F1 sends a `CM` message to G1. G1 sends a `t30-indicator(v8-ansam)` message to G2. G2 sends an `ANSam` message to F2. +- First Data Transfer:** F1 sends a `CM` message to G1. G1 sends a `t30-data(v8:cm_message:FAP)` message to G2. G2 sends a `CM` message to F2. +- Second Data Transfer:** F1 sends a `CM` message to G1. G1 sends a `t30-data(V8:jm_message:A0)` message to G2. G2 sends a `CM` message to F2. +- Third Data Transfer:** F1 sends a `CM` message to G1. G1 sends a `JM` message to G2. G2 sends a `JM` message to F2. +- Fourth Data Transfer:** F1 sends a `CM` message to G1. G1 sends a `JM` message to G2. G2 sends a `JM` message to F2. +- Fifth Data Transfer:** F1 sends a `CM` message to G1. G1 sends a `JM` message to G2. G2 sends a `JM` message to F2. +- Sixth Data Transfer:** F1 sends a `CJ` message to G1. G1 sends a `JM` message to G2. G2 sends a `CJ` message to F2. +- Final Messages:** F1 sends an `INFO0c` message. G1 sends an `INFO0a` message. G2 sends an `INFO0c` message. F2 sends an `INFO0c` message. + +The diagram uses vertical lines to represent the entities and horizontal arrows to represent the messages. The messages are labeled with their respective profiles and data. The sequence ends with a double slash (//) indicating the end of the session. + +T.38(15)\_FIV.1 + +Sequence diagram showing ITU-T V.8 signalling between F1, G1, G2, and F2. + +Figure IV.1 – ITU-T V.8 signalling (using profiles and acks) + +![Sequence diagram showing data rate negotiation and control channel start-up between four entities: F1, G1, G2, and F2. The diagram includes various protocol elements like TRN, PPh, ALT, MPh, E, Flags, DIS, DCS, CFR, and '1s'. It also contains timing and data transfer annotations such as t30-data(v34-pri-rate:v34-rate:336) and t30-data(v34-CC-1200:HDLC (DIS octets)). A central text block provides logic for rate negotiation based on G1 and G2 values.](b8dd9521b601d25e46c5effa0a59b7e1_img.jpg) + +if $G1 = G2$ then okay. No rate change needed. + If $G1 < G2$ then that too is okay since source data arrives slower than sink can send it. + If $G1 > G2$ then $G1$ rate needs to be reduced since the source data is faster than sink data. + +T.38(15)\_FIV.2 + +Sequence diagram showing data rate negotiation and control channel start-up between four entities: F1, G1, G2, and F2. The diagram includes various protocol elements like TRN, PPh, ALT, MPh, E, Flags, DIS, DCS, CFR, and '1s'. It also contains timing and data transfer annotations such as t30-data(v34-pri-rate:v34-rate:336) and t30-data(v34-CC-1200:HDLC (DIS octets)). A central text block provides logic for rate negotiation based on G1 and G2 values. + +Figure IV.2 – Data rate negotiation and control channel start-up + +![Sequence diagram Figure IV.3 showing data flow between F1, G1, G2, and F2 for partial page transmission. The diagram shows the transition from image data to control signals (PPS-NULL, MCF) and back to image data for the next partial page.](f512ae9c630f2fb53197fa77a1bda0e8_img.jpg) + +``` + + sequenceDiagram + participant F1 + participant G1 + participant G2 + participant F2 + + Note over F1, G2: t30-data(v34-pri-ch:HDLC:image octets) + Note over F1, G2: t30-data(v34-pri-ch:HDLC-FCS-OK-Sig-End) + Note over F1, G2: t30-indicator(v34_cntl_channel-1200) + + Note over G1, G2: t30-data(v34-cc-1200:HDLC:PPS-NULL) + Note over G1, G2: t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End) + + Note over G2, G1: t30-data(v34-cc-1200:HDLC:MCF) + Note over G2, G1: t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End) + + Note over G1, G2: t30-indicator(v34-pri-channel) + + Note over F1, G2: t30-data(v34-pri-ch:HDLC:image octets) + Note over F1, G2: t30-data(v34-pri-ch:HDLC:image octets) + +``` + +The diagram details the sequence of protocol elements and T.38 messages between four entities: F1, G1, G2, and F2. + +- F1** sequence: DATA, Flag, Sh, Sh\*, ALT, E, Flags, PPS-NULL, Flag, 1s, S, S\*, PP, B1, Flags, DATA. +- G1** sequence: Sh, Sh\*, ALT, E, FLAG, MCF, FLAG. +- G2** sequence: DATA, Flag, Sh, Sh\*, ALT, E, Flags, PPS-NULL, MCF, FLAG, 1s, S, S\*, PP, B1, Flags, DATA. +- F2** sequence: Sh, Sh\*, ALT, E, Flag, MCF, FLAG. + +Messages exchanged between G1 and G2 include control channel data (v34-cc-1200) for PPS-NULL and MCF, while primary channel data (v34-pri-ch) is used for image octets. + +Sequence diagram Figure IV.3 showing data flow between F1, G1, G2, and F2 for partial page transmission. The diagram shows the transition from image data to control signals (PPS-NULL, MCF) and back to image data for the next partial page. + +T.38(15)\_FIV.3 + +**Figure IV.3 – Between partial pages** + +![Sequence diagram showing data flow between F1, G1, G2, and F2. The diagram includes various data blocks like DATA, Flag, Sh, Sh*, ALT, E, PPS-EOP, MCF, DCN, and 1s, connected by arrows representing data transfer. The flow starts with F1 sending data to G1, which then sends it to G2. G2 then sends data back to G1, which finally sends it to F2. The diagram is labeled T.38(15)_FIV.4.](3eb2af31c2e61e2595c8440d726f5d4e_img.jpg) + +The diagram illustrates a sequence of data transfers between four entities: F1, G1, G2, and F2. The entities are represented by vertical lines with associated data blocks. The data blocks are labeled as follows: + +- F1:** DATA, Flag, Sh, Sh\*, ALT, E, Flag, PPS-EOP, Flag, DCN, Flag, 1s. +- G1:** Sh, Sh\*, ALT, E, Flag, MCF, FLAG. +- G2:** DATA, Flag, Sh, Sh\*, ALT, E, Flag, PPS-EOP, Flag, DCN, Flag, 1s. +- F2:** Sh, Sh\*, ALT, E, Flag, MCF, Flag. + +The data flow is as follows: + +- F1 sends **t30-data(v34-pri-ch:HDLC:octets)** to G1. +- G1 sends **t30-data(v34-pri-ch:HDLC-FCS-OK-Sig-End)** to G2. +- G2 sends **t30-indicator(v34-cntl-channel-1200)** to G1. +- G1 sends **t30-data(v34-CC-1200:HDLC:PPS-EOP)** to G2. +- G2 sends **t30-data(v34-CC-1200:HDLC-FCS-OK-Sig-End)** to G1. +- G1 sends **t30-data(v34-CC-1200:HDLC:MCF)** to G2. +- G2 sends **t30-data(v34-CC-1200:HDLC-FCS-OK-Sig-End)** to G1. +- G1 sends **t30-data(v34-CC-1200:HDLC:DCN)** to G2. +- G2 sends **t30-data(v34-CC-1200:HDLC-FCS-OK-Sig-End)** to G1. +- G1 sends **t30-data(v34-CC-1200:HDLC-Sig-End)** to G2. + +The diagram is labeled T.38(15)\_FIV.4. + +Sequence diagram showing data flow between F1, G1, G2, and F2. The diagram includes various data blocks like DATA, Flag, Sh, Sh\*, ALT, E, PPS-EOP, MCF, DCN, and 1s, connected by arrows representing data transfer. The flow starts with F1 sending data to G1, which then sends it to G2. G2 then sends data back to G1, which finally sends it to F2. The diagram is labeled T.38(15)\_FIV.4. + +T.38(15)\_FIV.4 + +Figure IV.4 – Last page + +![Sequence diagram showing the data rate change sequence when receiving G3FE initiates retraining. The diagram involves four entities: F1, G1, G2, and F2. It details the exchange of various signaling messages and data frames, including primary channel data, flags, and control channel retrain indicators. A central note explains that if F1/G1 Primary channel data signalling rate is greater than G2/F2 Primary channel data signalling rate, G1 changes its rate sequences and initiates a control channel retrain.](defe20e5056d0c3552de2d50ce88c5cb_img.jpg) + +**F2 requests data rate change** + +The diagram illustrates the sequence of events when F2 requests a data rate change, leading to a retrain initiated by G1. The participants are F1, G1, G2, and F2. + +**Sequence of Events:** + +- F1 sends **Primary channel data** to G1. +- G1 sends **t30-indicator(v34-cntl-channel-1200)** to G2. +- G2 sends **Primary channel data** to F2. +- F1 sends **Flags** to G1. +- G1 sends **Flags** to G2. +- G2 sends **Flags** to F2. +- F1 sends **Sh** to G1. +- G1 sends **Sh** to G2. +- G2 sends **Sh** to F2. +- F1 sends **/Sh** to G1. +- G1 sends **/Sh** to G2. +- G2 sends **/Sh** to F2. +- F1 sends **ALT** to G1. +- G1 sends **ALT** to G2. +- G2 sends **ALT** to F2. +- F1 sends **E** to G1. +- G1 sends **E** to G2. +- G2 sends **E** to F2. +- F1 sends **Flags** to G1. +- G1 sends **Flags** to G2. +- G2 sends **Flags** to F2. +- F1 sends **PPh** to G1. +- G1 sends **PPh** to G2. +- G2 sends **PPh** to F2. +- F1 sends **ALT** to G1. +- G1 sends **ALT** to G2. +- G2 sends **ALT** to F2. +- F1 sends **MPh** to G1. +- G1 sends **MPh** to G2. +- G2 sends **MPh** to F2. +- F1 sends **MPh** to G1. +- G1 sends **MPh** to G2. +- G2 sends **MPh** to F2. +- F1 sends **E** to G1. +- G1 sends **E** to G2. +- G2 sends **E** to F2. +- F1 sends **PPS-MPS** to G1. +- G1 sends **PPS-MPS** to G2. +- G2 sends **PPS-MPS** to F2. +- F1 sends **Flags** to G1. +- G1 sends **Flags** to G2. +- G2 sends **Flags** to F2. +- F1 sends **"1s"** to G1. +- G1 sends **"1s"** to G2. +- G2 sends **"1s"** to F2. +- F1 sends **S** to G1. +- G1 sends **S** to G2. +- G2 sends **S** to F2. +- F1 sends **/S** to G1. +- G1 sends **/S** to G2. +- G2 sends **/S** to F2. +- F1 sends **PP** to G1. +- G1 sends **PP** to G2. +- G2 sends **PP** to F2. + +**Central Note:** If F1/G1 Primary channel data signalling rate as indicated by PCrate is > G2/F2 Primary channel data signalling rate, then G1 changes its rate sequences and initiates a control channel retrain, while delaying transmission of MPS-PPS. + +**Additional Messages:** + +- G1 sends **t30-indicator(v34-cc-retrain)** to G2. +- G2 sends **t30-indicator(v34-cc-retrain)** to F2. +- G1 sends **t30-data(v34-pri-rate:v34rate:288)** to G2. +- G2 sends **t30-data(v34-pri-rate:v34rate:288)** to F2. +- G1 sends **t30-data(v34-CC-1200:HDLC:PPS-MPS)** to G2. +- G2 sends **t30-data(v34-CC-1200:HDLC:PPS-MPS)** to F2. +- G1 sends **t30-data(v34-CC-1200:HDLC:FCS-OK-Sig-End)** to G2. +- G2 sends **t30-data(v34-CC-1200:HDLC:FCS-OK-Sig-End)** to F2. +- G1 sends **t30-data(v34-CC-1200:HDLC:MCF)** to G2. +- G2 sends **t30-data(v34-CC-1200:HDLC:MCF)** to F2. +- G1 sends **t30-data(v34-CC-1200:HDLC:FCS-OK-Sig-End)** to G2. +- G2 sends **t30-data(v34-CC-1200:HDLC:FCS-OK-Sig-End)** to F2. +- G1 sends **t30-indicator(v34-pri-channel)** to G2. +- G2 sends **t30-indicator(v34-pri-channel)** to F2. + +T.38(15)\_FIV.5 + +Sequence diagram showing the data rate change sequence when receiving G3FE initiates retraining. The diagram involves four entities: F1, G1, G2, and F2. It details the exchange of various signaling messages and data frames, including primary channel data, flags, and control channel retrain indicators. A central note explains that if F1/G1 Primary channel data signalling rate is greater than G2/F2 Primary channel data signalling rate, G1 changes its rate sequences and initiates a control channel retrain. + +**Figure IV.5 – Data rate change sequence when receiving G3FE initiates retraining** + +**F1 requests data rate change** + +F1 + +G1 + +G2 + +F2 + +![Sequence diagram showing data rate change sequence between F1, G1, G2, and F2.](15a7570852cac42d754e4a0e50b1dfbe_img.jpg) + +The diagram shows a sequence of interactions for a data rate change initiated by F1. + Vertical lifelines for F1, G1, G2, and F2 are shown. + F1 sends 'Primary channel data' and 'Flags' to G1. + G1 sends 't30-indicator(v34-cntl-channel-1200)' to G2. + G2 sends 'Primary channel data' and 'Flags' to F2. + A series of handshakes (PPh, ALT, MPh, E) occurs between F1 and G1. + G2 and F2 exchange Sh, /Sh, ALT, /Sh, ALT, and E. + F1 sends 'PPS-MPS' to G1. + G1 sends 't30-data(v34-CC-1200:HDLC:PPS-MPS)' and 't30-data(v34-CC-1200:HDLC:FCS-OK-Sig-End)' to G2. + G2 sends 'PPS-MPS' to F2. + F2 responds with 'MCF' to G2. + G2 sends 't30-data(v34-CC-1200:HDLC:MCF)' and 't30-data(v34-CC-1200:HDLC:FCS-OK-Sig-End)' to G1. + G1 sends 'MCF' to F1. + G1 sends 't30-indicator(v34-pri-channel)' to G2. + Both sides then transition to '"1s"' and subsequent states (S, /S, PP). + +Central text: For the situation where F1 requires a rate change, this can be permitted as long as the rate requested meets the requirements as specified. The G2/F2 pair are not required to change rates. + +Sequence diagram showing data rate change sequence between F1, G1, G2, and F2. + +T.38(15)\_FIV.6 + +**Figure IV.6 – Data rate change sequence when calling G3FE initiates retraining** + +148 Rec. ITU-T T.38 (11/2015) + +![Sequence diagram showing the data rate change sequence when receiving gateway (G2) initiates retraining. The diagram involves four entities: F1, G1, G2, and F2. It details the exchange of primary channel data, flags, and various signaling messages (t30-indicator, t30-data) between these entities. A central note explains that if F1/G1 primary channel data signalling rate is greater than G2/F2 primary channel data signalling rate, G1 changes its rate sequences and initiates a control channel retrain. The diagram shows the flow of data and control signals, including a 1-second delay in G1's response to G2's indicator.](43f7b6b61db9a2f3e3920740a9527d97_img.jpg) + +**G2 requests data rate change** + +The diagram illustrates the sequence of events for a data rate change initiated by the receiving gateway (G2). The participants are F1, G1, G2, and F2. + +**Sequence of Events:** + +- F1 sends Primary channel data to G1. +- G1 sends Primary channel data to G2. +- G2 sends Primary channel data to F2. +- F1 sends Flags to G1. +- G1 sends Flags to G2. +- G2 sends Flags to F2. +- F1 sends Sh to G1. +- G1 sends Sh to G2. +- G2 sends Sh to F2. +- F1 sends /Sh to G1. +- G1 sends /Sh to G2. +- G2 sends /Sh to F2. +- F1 sends ALT to G1. +- G1 sends ALT to G2. +- G2 sends ALT to F2. +- F1 sends E to G1. +- G1 sends E to G2. +- G2 sends E to F2. +- F1 sends Flags to G1. +- G1 sends Flags to G2. +- G2 sends Flags to F2. +- F1 sends PPh to G1. +- G1 sends PPh to G2. +- G2 sends PPh to F2. +- F1 sends ALT to G1. +- G1 sends ALT to G2. +- G2 sends ALT to F2. +- F1 sends MPh to G1. +- G1 sends MPh to G2. +- G2 sends MPh to F2. +- F1 sends MPh to G1. +- G1 sends MPh to G2. +- G2 sends MPh to F2. +- F1 sends E to G1. +- G1 sends E to G2. +- G2 sends E to F2. +- F1 sends PPS-MPS to G1. +- G1 sends PPS-MPS to G2. +- G2 sends PPS-MPS to F2. +- F1 sends Flags to G1. +- G1 sends Flags to G2. +- G2 sends Flags to F2. +- F1 sends "1s" to G1. +- G1 sends "1s" to G2. +- G2 sends "1s" to F2. +- F1 sends S to G1. +- G1 sends S to G2. +- G2 sends S to F2. +- F1 sends /S to G1. +- G1 sends /S to G2. +- G2 sends /S to F2. +- F1 sends PP to G1. +- G1 sends PP to G2. +- G2 sends PP to F2. + +**Central Note:** If F1/G1 primary channel data signalling rate as indicated by PCrate is > G2/F2 primary channel data signalling rate, then G1 changes its rate sequences and initiates a control channel retrain, while delaying transmission of MPS-PPS. + +**Message Details:** + +- t30-indicator(v34-ctrl-channel-1200) +- t30-indicator(v34-CC-retrain) +- t30-data(v34-pri-rate:v34rate:264) +- t30-data(v34-CC-1200:HDLC:PPS-MPS) +- t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End) +- t30-data(v34-CC-1200:HDLC:MCF) +- t30-data(v34-CC-1200:HDLC:FCS-OK-Sig-End) +- t30-indicator(v34-pri-channel) + +T.38(15)\_FIV.7 + +Sequence diagram showing the data rate change sequence when receiving gateway (G2) initiates retraining. The diagram involves four entities: F1, G1, G2, and F2. It details the exchange of primary channel data, flags, and various signaling messages (t30-indicator, t30-data) between these entities. A central note explains that if F1/G1 primary channel data signalling rate is greater than G2/F2 primary channel data signalling rate, G1 changes its rate sequences and initiates a control channel retrain. The diagram shows the flow of data and control signals, including a 1-second delay in G1's response to G2's indicator. + +**Figure IV.7 – Data rate change sequence when receiving gateway initiates retraining** + +![Sequence diagram showing data rate change sequence between F1, G1, G2, and F2. The diagram includes various control and data frames like Primary channel data, Flags, Sh, /Sh, ALT, PPh, MPh, E, PPS-MPS, MCF, and '1s'. It also shows t30 data frames for HDLC control and primary channel data. A central note explains that G1's rate change request is permitted if it meets requirements, and G2/F2 do not need to change rates.](5cc9a312ebe733ae244e3b93cfea67e1_img.jpg) + +**G1 requests data rate change** + +For the situation where G1 requires a rate change, this can be permitted as long as the rate requested meets the requirements as specified. The G2/F2 pair are not required to change rates. + +The diagram illustrates the sequence of events for a data rate change initiated by G1. The participants are F1, G1, G2, and F2. The sequence includes the exchange of control frames (Flags, Sh, /Sh, ALT, PPh, MPh, E, PPS-MPS, MCF, '1s') and data frames (t30-data) between the entities. A central note specifies that G1's rate change request is permitted if it meets requirements, and G2/F2 are not required to change rates. + +Sequence diagram showing data rate change sequence between F1, G1, G2, and F2. The diagram includes various control and data frames like Primary channel data, Flags, Sh, /Sh, ALT, PPh, MPh, E, PPS-MPS, MCF, and '1s'. It also shows t30 data frames for HDLC control and primary channel data. A central note explains that G1's rate change request is permitted if it meets requirements, and G2/F2 do not need to change rates. + +T.38(15)\_FIV.8 + +**Figure IV.8 – Data rate change sequence when emitting gateway initiates retraining** + +![Sequence diagram for Turn-around polling showing interactions between F1, G1, G2, and F2. The diagram illustrates the flow of data and control signals between these entities, including various data blocks like DATA, Flags, Sh, Sh*, ALT, E, PPS-EOM, MCF, DIS, DTC, CM, JM, CJ, and INFO0c/a, and control signals like t30-data and t30-indicator.](ce06eec6bb6d76bf7688932b2f6eb6fa_img.jpg) + +The diagram illustrates the turn-around polling process between four entities: F1, G1, G2, and F2. The interactions are as follows: + +- F1 to G1:** + - DATA (t30-data(v34-pri-ch:HDLC:image octets)) + - Flags (t30-data(v34-pri-ch:HDLC-FCS-OK-Sig-End)) + - Sh (t30-indicator(v34-ctrl-channel-1200)) + - Sh\* + - ALT + - E + - PPS-EOM (t30-data(v34-cc-1200:HDLC:PPS-EOM)) + - Flags (t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End)) + - Flags (t30-data(v34-cc-1200:HDLC:MCF)) + - MCF (t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End)) + - Flags (t30-data(v34-cc-1200:HDLC:DIS)) + - DIS (t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End)) + - DTC (t30-data(v34-cc-1200:HDLC:DTC)) + - Flags (t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End)) + - 1s (t30-indicator(v8)) + - CM (t30-data(v8:cm\_message:FAP Prof 4)) + - CM + - CM + - CM + - CM + - CM + - CM + - CJ + - INFO0c +- G1 to G2:** + - DATA (t30-data(v34-pri-ch:HDLC:image octets)) + - Flags (t30-data(v34-pri-ch:HDLC-FCS-OK-Sig-End)) + - Sh (t30-indicator(v34-ctrl-channel-1200)) + - Sh\* + - ALT + - E + - Flags (t30-data(v34-cc-1200:HDLC:PPS-EOM)) + - PPS-EOM (t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End)) + - MCF (t30-data(v34-cc-1200:HDLC:MCF)) + - MCF (t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End)) + - Flags (t30-data(v34-cc-1200:HDLC:DIS)) + - DIS (t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End)) + - DTC (t30-data(v34-cc-1200:HDLC:DTC)) + - Flags (t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End)) + - 1s (t30-indicator(v8)) + - CM (t30-data(v8:cm\_message:FAP Prof 4)) + - CM + - CM + - CM + - CM + - CM + - CJ + - INFO0c +- G2 to F2:** + - DATA (t30-data(v34-pri-ch:HDLC:image octets)) + - Flags (t30-data(v34-pri-ch:HDLC-FCS-OK-Sig-End)) + - Sh (t30-indicator(v34-ctrl-channel-1200)) + - Sh\* + - ALT + - E + - Flags (t30-data(v34-cc-1200:HDLC:PPS-EOM)) + - PPS-EOM (t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End)) + - MCF (t30-data(v34-cc-1200:HDLC:MCF)) + - MCF (t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End)) + - Flags (t30-data(v34-cc-1200:HDLC:DIS)) + - DIS (t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End)) + - DTC (t30-data(v34-cc-1200:HDLC:DTC)) + - Flags (t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End)) + - 1s (t30-indicator(v8)) + - CM (t30-data(v8:cm\_message:FAP Prof 4)) + - CM + - CM + - CM + - CM + - CM + - CJ + - INFO0c +- F2 to F1:** + - DATA (t30-data(v34-pri-ch:HDLC:image octets)) + - Flags (t30-data(v34-pri-ch:HDLC-FCS-OK-Sig-End)) + - Sh (t30-indicator(v34-ctrl-channel-1200)) + - Sh\* + - ALT + - E + - PPS-EOM (t30-data(v34-cc-1200:HDLC:PPS-EOM)) + - Flags (t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End)) + - Flags (t30-data(v34-cc-1200:HDLC:MCF)) + - MCF (t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End)) + - Flags (t30-data(v34-cc-1200:HDLC:DIS)) + - DIS (t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End)) + - DTC (t30-data(v34-cc-1200:HDLC:DTC)) + - Flags (t30-data(v34-cc-1200:HDLC-FCS-OK-Sig-End)) + - 1s (t30-indicator(v8)) + - CM (t30-data(v8:cm\_message:FAP Prof 4)) + - CM + - CM + - CM + - CM + - CM + - CJ + - INFO0c + +Sequence diagram for Turn-around polling showing interactions between F1, G1, G2, and F2. The diagram illustrates the flow of data and control signals between these entities, including various data blocks like DATA, Flags, Sh, Sh\*, ALT, E, PPS-EOM, MCF, DIS, DTC, CM, JM, CJ, and INFO0c/a, and control signals like t30-data and t30-indicator. + +T.38(15)\_FIV.9 + +Figure IV.9 – Turn-around polling + + + +![Sequence diagram showing Manual Receive with V.8 capability indication.](3a9770b1a9c420c7473a5bd6feb5070c_img.jpg) + +``` + + sequenceDiagram + participant F1 + participant G1 + participant G2 + participant F2 + + Note right of F2: START + Note over F2: No answer tone (optional) + F1->>G1: CNG (repeated) + G2->>G1: t30-indicator(v21-preamble) + G2->>G1: t30-data(v21:HDLC:DIS octets) + Note over F2: DIS + G1->>F1: DIS + G2->>G1: t30-data(v21:HDLC-FCS-OK-Sig-End) + G2->>G1: t30-indicator(v21-preamble) + G2->>G1: t30-data(v21:HDLC:DIS octets) + Note over F2: DIS + G1->>F1: DIS + G2->>G1: t30-data(v21:HDLC-FCS-OK-Sig-End) + F1->>G1: CI + G1->>G2: t30-data(v8:ci-message: octet) + G2->>F2: CNG (repeated) + G2->>F2: CI (repeated) + G2->>G1: t30-indicator(v8-ansam) + Note over F2: ANSam + Note over G1,G2: ANSam + F1->>G1: CM (repeated) + G1->>G2: t30-data(v8:cm-message:FAP) + G2->>F2: CM (repeated) + Note over F2: JM + F2->>G2: JM (repeated) + G2->>G1: t30-data(v8:jm-message:A0) + G1->>F1: JM (repeated) + F1->>G1: CJ + G2->>F2: CJ + Note over F2: INFO0a + Note over G2: INFO0c + Note over G1: INFO0a + Note over F1: INFO0c + +``` + +The diagram illustrates the signal flow for a manual receive fax call where V.8 capability is indicated. It shows the transition from V.21 DIS signals to V.8 negotiation (ANSam, CM, JM). F1 sends CNG and then CI. G2 sends DIS twice. Upon receiving CI, G2 switches to V.8 mode, sending ANSam. F1 responds with CM, F2 responds with JM, and the session proceeds to INFO0 exchange. + +T.38(15)\_FIV.11 + +Sequence diagram showing Manual Receive with V.8 capability indication. + +**Figure IV.11 – Manual Receive (DIS has bit 6 set to 1 to indicate ITU-T V.8 capability)** + + Rec. ITU-T T.38 (11/2015) 153 + +# Appendix V + +## ITU-T T.38 implementation guidelines + +(This appendix does not form an integral part of this Recommendation.) + +This appendix provides guidance for implementers to improve interoperability amongst ITU-T T.38 devices, based on experience gained with actual implementations of the ITU-T T.38 specification. + +## V.1 General issue + +### V.1.1 Transmission bit order + +The transmission bit order complies with clauses 7.1.1 and 7.1.2. As an example, DIS frame starts with "7E FF C8 01 ...": + +| | | | | | | | | +|----------|---|----------|---|----------|---|----------|---| +| 7E | | FF | | C8 | | 01 | | +| 01111110 | | 11111111 | | 11001000 | | 00000001 | | +| B | E | B | E | B | E | B | E | + +'B' means "beginning" and 'E' means "end" in each octet. 'B' bit is first stored in an octet of IP packet and is first transmitted. + +### V.1.2 Interval between packets + +An interval between a preamble packet and an ITU-T T.30 signal packet, and an interval between a training packet and an image packet, may be necessary for some gateway implementations, because they do not have enough buffers for dealing with multiple packets. When multiple ITU-T T.30 signals like CSI and DIS are sent, an interval between the signals may be necessary for some gateway implementations for the same reason. + +In addition, when packets are sent to gateway, they should be sent at the negotiated modem speed in DIS/DCS exchange. IAF implementations may be particularly prone to this problem because there is no fax terminal connected to GSTN where the modem limits the rate at which packets can be created. + +### V.1.3 Preamble packet between ITU-T T.30 signals + +Some implementations incorrectly send a preamble packet between ITU-T T.30 signal packets. An ITU-T T.38 implementation that receives a sequence of this type, should handle it properly. For example, the received preamble packet before "sig-end" in field-type should be regarded as flag (0x7e). + +### V.1.4 Disassembly of one signal in packet + +Some implementations send one ITU-T T.30 signal frame in one packet and other implementations send it in multiple packets. Therefore, an ITU-T T.38 implementation should handle both situations and assemble the multiple packets when necessary. This principle applies to image packets as well. Some implementations place an entire HDLC frame (between flags) into a single packet, others may ignore the frame boundaries when inserting the data into packets. + +### V.1.5 Limitation of packet size + +Some implementations limit the packet size to receive even in **tcp** mode. The limitation often relates to the size of one ECM packet. It is the responsibility of the sender to address this situation. + +One possibility is to use the same packet size regardless of whether the transport protocol is **tcp** or **udp** and regardless of whether the remote side is an IAF or a gateway. + +In **udp** mode, the `t38FaxMaxDatagram` value negotiated in call set-up, should be used to determine the size of the packets. + +### V.1.6 Packet of transferred TCF + +A series of ZEROs for 1.5 s must be sent in one or more packets in transferred TCF, based on the negotiated modem speed in DIS/DCS exchange. An IAF sender must generate the TCF if the receiving ITU-T T.38 devices is not an IAF. + +### V.1.7 Network engineering guidelines + +#### V.1.7.1 Network engineering with T.38 gateways + +##### V.1.7.1.1 Single T.38 FoIP network domain + +Figure V.0a recalls again the underlying network configuration, which was the baseline when ITU-T T.38 was developed. + +![Figure V.0a: End-to-end facsimile transmission over a single interim IP network domain. The diagram shows a sequence of components: a Standard fax terminal (= G3FE) labeled as ITU-T T.4 terminal, connected to a PSTN cloud, then a PSTN-IP gateway labeled as ITU-T T.38 gateway, followed by an IP network cloud, another PSTN-IP gateway labeled as ITU-T T.38 gateway, another PSTN cloud, and finally another Standard fax terminal (= G3FE) labeled as ITU-T T.4 terminal. A double-headed arrow labeled 'ITU-T T.38 FoIP' spans the IP network and the two PSTN-IP gateways. Below the rightmost terminal is the label 'T.38(15)_FV.0a'.](dc79f71c6bae35b5d62f636dbc7f9bb9_img.jpg) + +Figure V.0a: End-to-end facsimile transmission over a single interim IP network domain. The diagram shows a sequence of components: a Standard fax terminal (= G3FE) labeled as ITU-T T.4 terminal, connected to a PSTN cloud, then a PSTN-IP gateway labeled as ITU-T T.38 gateway, followed by an IP network cloud, another PSTN-IP gateway labeled as ITU-T T.38 gateway, another PSTN cloud, and finally another Standard fax terminal (= G3FE) labeled as ITU-T T.4 terminal. A double-headed arrow labeled 'ITU-T T.38 FoIP' spans the IP network and the two PSTN-IP gateways. Below the rightmost terminal is the label 'T.38(15)\_FV.0a'. + +**Figure V.0a – End-to-end facsimile transmission over a single interim IP network domain** + +Thus, there is supposed to be a single IP network domain only within the end-to-end communication path for facsimile information. Such a network configuration is the primary scope of T.38, see Figure 1, but also all illustrations related to network configurations in Annexes D, E and F, as well as in Appendices II, III and IV. The T.38 FoIP service was not designed to cover multiple IP network domains (as outlined in next clause). + +##### V.1.7.1.2 Multiple T.38 FoIP network domains + +Figure V.0b illustrates an end-to-end facsimile transmission over multiple interim IP network domains. + +![Figure V.0b: End-to-end facsimile transmission over multiple interim IP network domains. The diagram shows a sequence of components: a Standard fax terminal (= G3FE) labeled as ITU-T T.4 terminal, connected to a PSTN cloud, then a PSTN-IP gateway labeled as ITU-T T.38 gateway, followed by an IP network cloud, another PSTN-IP gateway labeled as ITU-T T.38 gateway, and a PSTN cloud. This is followed by a break symbol (//), then another PSTN cloud, a PSTN-IP gateway labeled as ITU-T T.38 gateway, an IP network cloud, another PSTN-IP gateway labeled as ITU-T T.38 gateway, and a PSTN cloud, and finally another Standard fax terminal (= G3FE) labeled as ITU-T T.4 terminal. A double-headed arrow labeled 'ITU-T T.38 FoIP' spans the first IP network and its gateways. Another double-headed arrow labeled 'ITU-T T.38 FoIP' spans the second IP network and its gateways. Dashed lines below the first and second IP network sections are labeled 'IP network domain 1 with ITU-T T.38 service' and 'IP network domain N with ITU-T T.38 service' respectively. Below the rightmost terminal is the label 'T.38(15)_FV.0b'.](0d4c85e57a0386f48be3fbe6165b5598_img.jpg) + +Figure V.0b: End-to-end facsimile transmission over multiple interim IP network domains. The diagram shows a sequence of components: a Standard fax terminal (= G3FE) labeled as ITU-T T.4 terminal, connected to a PSTN cloud, then a PSTN-IP gateway labeled as ITU-T T.38 gateway, followed by an IP network cloud, another PSTN-IP gateway labeled as ITU-T T.38 gateway, and a PSTN cloud. This is followed by a break symbol (//), then another PSTN cloud, a PSTN-IP gateway labeled as ITU-T T.38 gateway, an IP network cloud, another PSTN-IP gateway labeled as ITU-T T.38 gateway, and a PSTN cloud, and finally another Standard fax terminal (= G3FE) labeled as ITU-T T.4 terminal. A double-headed arrow labeled 'ITU-T T.38 FoIP' spans the first IP network and its gateways. Another double-headed arrow labeled 'ITU-T T.38 FoIP' spans the second IP network and its gateways. Dashed lines below the first and second IP network sections are labeled 'IP network domain 1 with ITU-T T.38 service' and 'IP network domain N with ITU-T T.38 service' respectively. Below the rightmost terminal is the label 'T.38(15)\_FV.0b'. + +**Figure V.0b – End-to-end facsimile transmission over multiple interim IP network domains** + +A multiple ITU-T T.38 domain configuration could be e.g. the result when: + +- ITU-T T.38 is used at (IP) access network level and TDM is used at core network level; or +- multiple network operators use TDM for core-to-core network interconnection. + +It has to be noted that ITU-T T.38 was *not* designed for end-to-end facsimile transmission over multiple interim IP network domains, hence may *not* provide any guarantees for reliable service support. Such kind of ITU-T T.38 network engineering is therefore *not recommended*! + +Background: + +The ITU-T T.38 gateway is supposed to be connected directly with a remote fax terminal across a PSTN link. There are timing conditions at modem level, protocol timers at T.30 endpoints, inherent delays of ITU-T T.30-to-ITU-T T.38 transcoders and ITU-T T.38 capabilities such as data rate management tuned for such a network and gateway model. There is a single on-ramp and off-ramp ITU-T T.38 supposed to be in the communication path. The occurrence of ITU-T T.38 gateway pairs, linked via an interim PSTN domain (as the result of a Figure V.0b configuration), was out of scope when ITU-T T.38 was designed. + +Alternative IP emulation service for facsimile transport: + +End-to-end facsimile transmission over multiple interim IP network domains could use voiceband data over IP (VBDoIP) [ITU-T V.152] as alternative transport. It is recommended that all IP domains should use consistently ITU-T V.152 in an end-to-end manner. + +#### V.1.7.2 Network engineering with ITU-T V.153 gateways + +A ITU-T V.153 gateway is positioned for the interconnection of two IP network domains and provides a ITU-T T.38 (FoIP) to ITU-T V.152 (VBDoIP) interworking service, see [ITU-T V.153]. There are similar network engineering constraints due to ITU-T T.38. + +##### V.1.7.2.1 Single ITU-T T.38 FoIP network domain + +Figure V.0c recalls again the underlying network configuration for ITU-T T.38 to ITU-T V.152 interworking (see also Figure 2/[ITU-T V.153]): + +![Figure V.0c: End-to-end facsimile transmission over a single pair of ITU-T T.38 and ITU-T V.152 IP network domains, using a ITU-T V.153 gateway. The diagram shows a sequence of components: a Standard fax terminal (= G3FE) connected to a PSTN cloud, then a PSTN-IP gateway, followed by an IP network cloud. This is connected to an IP-IP gateway, followed by another IP network cloud, then another PSTN-IP gateway, and finally another PSTN cloud connected to another Standard fax terminal (= G3FE). Above the IP-IP gateway, two double-headed arrows indicate connections: one labeled 'ITU-T T.38 FoIP' connecting to the first PSTN-IP gateway, and another labeled 'ITU-T V.152 VBDoIP' connecting to the second PSTN-IP gateway. Below the IP networks, two dashed boxes represent 'IP network domain 1 with ITU-T T.38 service' and 'IP network domain 2 with ITU-T V.152 service'. The entire diagram is labeled 'T.38(15)_FV.0c' at the bottom right.](351432d1a55458897fdc5e81ffc832fe_img.jpg) + +Figure V.0c: End-to-end facsimile transmission over a single pair of ITU-T T.38 and ITU-T V.152 IP network domains, using a ITU-T V.153 gateway. The diagram shows a sequence of components: a Standard fax terminal (= G3FE) connected to a PSTN cloud, then a PSTN-IP gateway, followed by an IP network cloud. This is connected to an IP-IP gateway, followed by another IP network cloud, then another PSTN-IP gateway, and finally another PSTN cloud connected to another Standard fax terminal (= G3FE). Above the IP-IP gateway, two double-headed arrows indicate connections: one labeled 'ITU-T T.38 FoIP' connecting to the first PSTN-IP gateway, and another labeled 'ITU-T V.152 VBDoIP' connecting to the second PSTN-IP gateway. Below the IP networks, two dashed boxes represent 'IP network domain 1 with ITU-T T.38 service' and 'IP network domain 2 with ITU-T V.152 service'. The entire diagram is labeled 'T.38(15)\_FV.0c' at the bottom right. + +**Figure V.0c – End-to-end facsimile transmission over a single pair of ITU-T T.38 and ITU-T V.152 IP network domains, using a ITU-T V.153 gateway** + +Such a network solution is feasible and implies the usage of a V.153 gateway at the interconnection point of the two IP network domains. + +##### V.1.7.2.2 Two interconnected ITU-T T.38 FoIP network domains + +Multiple ITU-T T.38 FoIP network domains might be interconnected via IP-to-IP gateways, such as an *ITU-T IP-to-IP voice gateway* [b-ITU-T G.799.3] or *3GPP Transition gateway* [b-ETSI TS 129 238]. Figure V.0d illustrates the network configuration. + +![Figure V.0d: End-to-end facsimile transmission over two interconnected ITU-T T.38 FoIP network domains. The diagram shows a sequence of components: a Standard fax terminal (= G3FE) connected to a PSTN, then a PSTN-IP gateway, followed by an IP network, an IP-IP gateway, another IP network, another PSTN-IP gateway, another PSTN, and finally another Standard fax terminal (= G3FE). Above the sequence, a double-headed arrow labeled 'ITU-T T.38 FoIP' spans from the first PSTN-IP gateway to the second. Below the sequence, two dashed boxes represent 'IP network domain 1 with ITU-T T.38 service' (covering the first IP network and IP-IP gateway) and 'IP network domain 2 with ITU-T T.38 service' (covering the second IP network and IP-IP gateway). The central IP-IP gateway is labeled 'ITU-T T.38 agnostic'. Labels below the gateways indicate they are 'ITU-T T.38 gateway'. The terminals are labeled 'ITU-T T.4 terminal'. The reference 'T.38(15)_FV.0d' is at the bottom right.](54f73f693f36dcbd300fa21ac4e410e8_img.jpg) + +Figure V.0d: End-to-end facsimile transmission over two interconnected ITU-T T.38 FoIP network domains. The diagram shows a sequence of components: a Standard fax terminal (= G3FE) connected to a PSTN, then a PSTN-IP gateway, followed by an IP network, an IP-IP gateway, another IP network, another PSTN-IP gateway, another PSTN, and finally another Standard fax terminal (= G3FE). Above the sequence, a double-headed arrow labeled 'ITU-T T.38 FoIP' spans from the first PSTN-IP gateway to the second. Below the sequence, two dashed boxes represent 'IP network domain 1 with ITU-T T.38 service' (covering the first IP network and IP-IP gateway) and 'IP network domain 2 with ITU-T T.38 service' (covering the second IP network and IP-IP gateway). The central IP-IP gateway is labeled 'ITU-T T.38 agnostic'. Labels below the gateways indicate they are 'ITU-T T.38 gateway'. The terminals are labeled 'ITU-T T.4 terminal'. The reference 'T.38(15)\_FV.0d' is at the bottom right. + +**Figure V.0d – End-to-end facsimile transmission over two interconnected ITU-T T.38 FoIP network domains** + +Such a network solution is feasible under the condition that the IP-to-IP gateway is not enabled for any kind of ITU-T T.38 processing! The IP-to-IP gateway is rather required to provide a pure packet forwarding mode (e.g., *UDP transparent forwarding* in case of ITU-T T.38 transport mode "UDPTL/UDP"), resulting in a single, virtual ITU-T T.38 FoIP domains across the two IP networks. + +It is up to the control plane to indicate and negotiate a common ITU-T T.38 configuration across all interconnected IP network segments. + +##### V.1.7.2.3 Multiple ITU-T T.38 FoIP network domains interrupted by ITU-T V.152 VBDolP network sections + +Figure V.0e illustrates such a configuration at the example of ITU-T T.38 FoIP network domains, interconnected by an interim ITU-T V.152 VBDolP domain. + +![Figure V.0e: Multiple ITU-T T.38 FoIP network domains interrupted by ITU-T V.152 VBDolP network sections. The diagram shows a sequence of components: a Standard fax terminal (= G3FE) connected to a PSTN, then a PSTN-IP gateway, followed by an IP network, an IP-IP gateway, another IP network, another IP-IP gateway, another IP network, another PSTN-IP gateway, another PSTN, and finally another Standard fax terminal (= G3FE). Above the sequence, three double-headed arrows indicate the domains: 'ITU-T T.38 FoIP' (from first PSTN-IP gateway to first IP-IP gateway), 'ITU-T V.152 VBDolP' (between the two IP-IP gateways), and 'ITU-T T.38 FoIP' (from second IP-IP gateway to second PSTN-IP gateway). Below the sequence, three dashed boxes represent 'IP network domain 1 with ITU-T T.38 service' (first IP network and gateway), 'IP network domain 2 with ITU-T V.152 service' (the V.152 section), and 'IP network domain 3 with ITU-T T.38 service' (second IP network and gateway). Labels below the gateways indicate they are 'ITU-T T.38 gateway' or 'ITU-T V.153 gateway'. The terminals are labeled 'ITU-T T.4 terminal'. The reference 'T.38(15)_FV.0e' is at the bottom right.](3ea179b463e612d0285714550eaf5c09_img.jpg) + +Figure V.0e: Multiple ITU-T T.38 FoIP network domains interrupted by ITU-T V.152 VBDolP network sections. The diagram shows a sequence of components: a Standard fax terminal (= G3FE) connected to a PSTN, then a PSTN-IP gateway, followed by an IP network, an IP-IP gateway, another IP network, another IP-IP gateway, another IP network, another PSTN-IP gateway, another PSTN, and finally another Standard fax terminal (= G3FE). Above the sequence, three double-headed arrows indicate the domains: 'ITU-T T.38 FoIP' (from first PSTN-IP gateway to first IP-IP gateway), 'ITU-T V.152 VBDolP' (between the two IP-IP gateways), and 'ITU-T T.38 FoIP' (from second IP-IP gateway to second PSTN-IP gateway). Below the sequence, three dashed boxes represent 'IP network domain 1 with ITU-T T.38 service' (first IP network and gateway), 'IP network domain 2 with ITU-T V.152 service' (the V.152 section), and 'IP network domain 3 with ITU-T T.38 service' (second IP network and gateway). Labels below the gateways indicate they are 'ITU-T T.38 gateway' or 'ITU-T V.153 gateway'. The terminals are labeled 'ITU-T T.4 terminal'. The reference 'T.38(15)\_FV.0e' is at the bottom right. + +**Figure V.0e – Multiple ITU-T T.38 FoIP network domains interrupted by ITU-T V.152 VBDolP network sections** + +Such kind of network engineering could lead to problems because they were out of scope during the design of ITU-T T.38, ITU-T V.152 and ITU-T V.153. Thus, again there are no guarantees for reliable service support due to similar reasons as outlined in clause V.1.7.1.2. Such kind of T.38 network engineering is therefore *not* recommended. + +## V.2 IAF issues + +### V.2.1 ITU-T T.30 timer value + +When both implementations are IAFs, ITU-T T.30 timer values may be extended by two or three times. Extension of the timers allows two terminals to have successful facsimile transactions in certain difficult environments. These environments include narrow-band transports or when there is a high degree of network delay and/or loss of packets. Bit 123 in DIS/DCS is the negotiation bit that indicates an IAF device. + +### **V.2.2 Data rate between IAFs** + +When TCP is selected, the data rate between IAFs is not limited by modem speeds indicated in DIS/DTC (see clause 8.1) and can be as fast a rate as both sides can support. TCP allows both sides to ignore the MaxBitRate attribute and rely on the protocol itself to throttle the data transfer between the two IAFs. + +### **V.2.3 Data rate between IAFs and gateways** + +If a gateway does not support TCP, an IAF shall send data so as to not cause a buffer overflow in the receiving gateway. A potential problem arises because the messages and data are sent without HDLC framing (insertion of FLAGS and ZEROS) and an IAF is not limited by a fax modem in the speed that it can generate messages and data. The likely effect of this problem for image data is one or more ECM frames in error. + +The sending IAF should send packets that, by some means, account for the overhead due to the HDLC framing that is added by the receiving gateway, so as to not overflow the gateway's buffer. + +## **V.3 Call set-up issues** + +### **V.3.1 CalledPartyNumber in Setup (Annex B)** + +The destination fax number should be set in CalledPartyNumber of Setup. Some receiving gateways have several fax ports and use the information to select one. + +### **V.3.2 Announcement of voice capability** + +ITU-T H.323 gateway implementations generally support voice communication as the default and initial call type. When an ITU-T T.38 Annex B implementation calls an ITU-T H.323 Annex D implementation, the ITU-T T.38 implementation may need to indicate voice capability in call set-up, even if it wants only fax communication. + +### **V.3.3 Incorrect use of the colon (":") in several ITU-T T.38 attributes in Annex D** + +Some equipment vendors have incorrectly implemented the ABNF as defined in Annex D for several parameters: T38FaxFillBitRemoval, T38FaxTranscodingMMR, and T38FaxTranscodingJBIG. Several implementers incorrectly assumed that these attributes have a value (an "att-value" in SDP) following a colon (e.g., "a=T38FaxTranscodingJBIG:0"), but they do not. Implementers should treat the presence of the attribute as "true" and absence as "false", regardless of any attribute value that might be present. Furthermore, implementers shall not construct SDP attribute lines for these Boolean attributes that include a colon and attribute value. A proper attribute line for T38FaxTranscodingJBIG, for example, is "a=T38FaxTranscodingJBIG". + +The correct behaviour of these parameters is defined in clauses D.2.3.1 and D.2.3.2. + +### **V.3.4 Case sensitivity of udptl and T38MaxBitRate in SIP and ITU-T H.248.1** + +There are case differences between the ITU-T T.38 and IANA definitions of udptl (UDPTL) and T38MaxBitRate (T38maxBitRate) for SIP and ITU-T H.248.1. The preferred implementation is the ITU-T T.38 definitions, namely udptl and T38MaxBitRate. + +## **V.4 Others** + +### **V.4.1 Delay to report the DCN to MGC** + +It is possible for a gateway after receiving a DCN signal from a transmitting facsimile terminal to initiate the transition to AUDIO. If this mode switch is too fast, there is a possibility that the playout + +of the DCN signal from the remote gateway may be truncated prematurely due to receiving the transition request from a media gateway controller. + +When the DCN transition mode is adopted, delay (for example, 600 ms) is needed between when the MG(DSP) detects the DCN and reports this event to the MGC, to ensure that the gateway can send the complete DCN to the facsimile terminal. + +![Sequence diagram showing the interaction between G3FE 1, MG 1, MG C, MG 2, and G3FE 2 during a mode transition from ITU-T T.38 mode to Voice mode. MG 1 receives a DCN from G3FE 1, sends an ITU-T T.38 package with DCN to MG C, and then sends an event:fax-end to MG C. MG C sends a Modify message to MG 2, which then sends a DCN to G3FE 2. MG 1 also sends an ACK to MG C, and MG C sends an ACK to MG 2. A 600 ms timer is shown between MG 1 receiving the DCN and sending the event:fax-end message.](10f4e3a2f3c016555ee12a5b556ba834_img.jpg) + +``` +sequenceDiagram + participant G3FE1 as G3FE 1 + participant MG1 as MG 1 + participant MGC as MG C + participant MG2 as MG 2 + participant G3FE2 as G3FE 2 + + Note over G3FE1, MG1: ITU-T T.38 mode + G3FE1->>MG1: DCN + MG1->>MGC: ITU-T T.38 package with DCN + MG1->>MGC: event:fax-end + MGC->>MG2: Modify + MG2->>G3FE2: DCN + MG1->>MGC: ACK + MGC->>MG2: ACK + Note over G3FE1, MG1: Voice mode +``` + +T.38(15)\_FV.1 + +Sequence diagram showing the interaction between G3FE 1, MG 1, MG C, MG 2, and G3FE 2 during a mode transition from ITU-T T.38 mode to Voice mode. MG 1 receives a DCN from G3FE 1, sends an ITU-T T.38 package with DCN to MG C, and then sends an event:fax-end to MG C. MG C sends a Modify message to MG 2, which then sends a DCN to G3FE 2. MG 1 also sends an ACK to MG C, and MG C sends an ACK to MG 2. A 600 ms timer is shown between MG 1 receiving the DCN and sending the event:fax-end message. + +**Figure V.1 – MG1 uses timer before initiating mode transition request** + +# Appendix VI + +## Security considerations from a historical perspective + +(This appendix does not form an integral part of this Recommendation.) + +## VI.1 Historical origin and use of Recommendation ITU-T T.38 + +Recommendation ITU-T T.38 itself does not define any explicit means for security support. The rationale behind it can be found in the historical usage and evolution of packet-switched networks with real-time transport of facsimile data. + +Figure VI.1 simplifies the history by dividing the past two decades into four significant phases. The predecessor technology of ITU-T T.38 is ITU-T X.38 (see [b-ITU-T X.38]). ITU-T T.38 shares many capabilities from ITU-T X.38. ITU-T X.38 itself (phase 1) did not provide any security support, primarily because: + +- ITU-T X.38 was only used between two gateways (the emitting and receiving gateway); +- network access via PSTN only, and PSTN is per se a trusted domain (as circuit-switched network); and +- packet data network (PDN) is an overlay on top of a circuit-/frame-switched network, again a network technology highly robust against potential security attacks. + +ITU-T T.38 was initially (and still is) deployed in PSTN emulation systems (PES; phase 2). IP transport was/is limited on the network core level, typically a managed (and trusted) IP network. + +Recommendation ITU-T T.38 (1998 to 2010) primarily gave scope to such types of service deployments (phase 2), thus, there were no explicit security requirements received for support by ITU-T T.38. This assumption could be confirmed by the stage 1/2 specification for ITU-T T.38: the service definition for Internet facsimile F.185 [ITU-T F.185] does not define any security requirements. + +NOTE – [b- Nagireddi] mentions using the ITU-T T.38 FEC capability for security support: + +*"Forward error correction is used in many digital communication systems. It is also useful in ITU-T T.38 ... based fax calls as given in ... A FEC technique also helps to encrypt the transmitted bits that help in sending secured VoIP voice and fax. Some FEC - based techniques are reported as patented for VoIP as a part of a secured VoIP communication"* + +Almost all new wireline and wireless access technologies provide IP support; this means that ITU-T T.38 PSTN-IP gateways (phase 3) may no longer be required. The ITU-T T.38 endpoint is located in the IP-based end user equipment itself, the so called IAF terminal. The IP-based access network becomes the focal point of security discussions (e.g., trusted or untrusted network segment). + +The last evolution step would be an all IP network (phase 4). ITU-T T.38 might then be replaced by better-suited IP transport technologies, but typically still be dependent on legal requirements for electronic documents. + +![Figure VI.1: Real-time facsimile over packet networks – Simplified network evolution over the past two decades. The diagram shows four phases of network evolution for real-time facsimile.](669c88c4149a2add62ce1cbc7e8bb659_img.jpg) + +**Phase 1 ("pre-ITU-T T.38"):** + +Standard fax terminal (= G3FE) ITU-T T.4 terminal + +PSTN + +ITU-T X.38 gateway + +ITU-T X.38 gateway + +Packet data network (PDN) + +ITU-T X.38 FoPDN + +Standard fax terminal (= G3FE) ITU-T T.4 terminal + +**Phase 2 ("PSTN emulation systems"):** + +Standard fax terminal (= G3FE) ITU-T T.4 terminal + +PSTN + +ITU-T T.38 gateway + +ITU-T T.38 gateway + +IP network + +ITU-T T.38 FoIP + +Standard fax terminal (= G3FE) ITU-T T.4 terminal + +**Phase 3 ("mix of PSTN- and IP-based network access"):** + +Internet aware fax terminal (IAF) ITU-T T.38 terminal + +IP network + +ITU-T T.38 gateway + +PSTN + +ITU-T T.38 FoIP + +Standard fax terminal (= G3FE) ITU-T T.4 terminal + +**Phase 4 ("all IP"):** + +Internet aware fax terminal (IAF) ITU-T T.38 terminal + +IP network + +ITU-T T.38 FoIP + +Internet aware fax terminal (IAF) ITU-T T.38 terminal + +Figure VI.1: Real-time facsimile over packet networks – Simplified network evolution over the past two decades. The diagram shows four phases of network evolution for real-time facsimile. + +T.38(10)-Amd.1(14) FV1.1 + +**Figure VI.1 – Real-time facsimile over packet networks – Simplified network evolution over the past two decades** + +## VI.2 Application vs network/transport level security + +ITU-T T.38 usage in deployments with IP-based network access (phase 3) appears to be the most critical scenario from a security perspective. Security could in principle be supported at multiple protocol layers; see Figure VI.2. + +![Diagram illustrating Application vs network/transport level security in a fax communication system. The system consists of an Internet aware fax terminal (IAF) connected to an IP network, which is connected to a PSTN-IP gateway, then a PSTN, and finally a Standard fax terminal (= G3FE). Three security levels are shown: a) End-to-end communication: application level security (e.g., ITU-T T.30 image encryption) spanning the entire path; b) IP domain: transport level security (e.g., DTLS, TLS, SRTP) spanning the IP network and the connection to the PSTN-IP gateway; c) IP domain: network level security (e.g., IPsec) spanning the IP network. A dashed line labeled 'ITU-T T.38 FoIP' connects the IAF to the PSTN-IP gateway. The diagram is labeled 'T.38(10)-Amd.1(14), F.VI.2'.](bdee2715697a4142d16a360549fa7c7f_img.jpg) + +Diagram illustrating Application vs network/transport level security in a fax communication system. The system consists of an Internet aware fax terminal (IAF) connected to an IP network, which is connected to a PSTN-IP gateway, then a PSTN, and finally a Standard fax terminal (= G3FE). Three security levels are shown: a) End-to-end communication: application level security (e.g., ITU-T T.30 image encryption) spanning the entire path; b) IP domain: transport level security (e.g., DTLS, TLS, SRTP) spanning the IP network and the connection to the PSTN-IP gateway; c) IP domain: network level security (e.g., IPsec) spanning the IP network. A dashed line labeled 'ITU-T T.38 FoIP' connects the IAF to the PSTN-IP gateway. The diagram is labeled 'T.38(10)-Amd.1(14), F.VI.2'. + +**Figure VI.2 – Application vs network/transport level security** + +The scope of network and transport level security is limited to the IP network. There are multiple options for transport level security, which are dependent on the ITU-T T.38 transport mode (see clause 3.6). + +Application level security would be related to the encoding of the facsimile document (also known as image) itself. [ITU-T T.30] defines two optional security support functions (see Annexes G and H in [ITU-T T.30]), in order to provide document confidentiality and document integrity. + +# Bibliography + +- [b-ITU-T G.799.3] Recommendation ITU-T G.799.3 (05/2011), *Signal processing functionality and performance of an IP-to-IP voice gateway optimized for the transport of voice and voiceband data.* +- [b-ITU-T X.38] Recommendation ITU-T X.38 (1996), *G3 facsimile equipment/DCE interface for G3 facsimile equipment accessing the Facsimile Packet Assembly/Disassembly facility (FPAD) in a public data network situated in the same country.* +- [b-ETSI TS 129 238] ETSI TS 129 238 (04/2015), *Digital cellular telecommunications system (Phase 2+); Universal Mobile Telecommunications System (UMTS); LTE; Interconnection Border Control Functions (IBCF) - Transition Gateway (TrGW) interface, Ix interface; Stage 3 (3GPP TS 29.238 version 12.5.0 Release 12).* +- [b-IETF RFC 2833] IETF RFC 2833 (2000), *RTP Payload for DTMF Digits, Telephony Tones and Telephony Signals.* +- [b-IETF RFC 4566] IETF RFC 4566 (2006), *SDP: Session Description Protocol.* +- [b-IETF RFC 4734] IETF RFC 4734 (2006), *Definition of Events for Modem, Fax, and Text Telephony Signals.* +- [b-IETF RFC 6871] IETF RFC 6871 (2013), *SDP Media Capabilities Negotiation.* +- [b-Nagireddi] Nagireddi, S. (2008), *VoIP Voice and Fax Signal Processing.* Wiley, ISBN 978-0-470-22736-7. + + + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.390-198811-I_PDF-E/raw.md b/marked/T/T-REC-T.390-198811-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..629f4313db25bf77ab93de681bf901bead928890 --- /dev/null +++ b/marked/T/T-REC-T.390-198811-I_PDF-E/raw.md @@ -0,0 +1,683 @@ + + +![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU and a lightning bolt symbol. + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**T.390** + +**TERMINAL EQUIPMENT AND PROTOCOLS FOR +TELEMATIC SERVICES** + +--- + +**TELETEX REQUIREMENTS FOR +INTERWORKING WITH THE TELEX SERVICE** + +**ITU-T Recommendation T.390** + +(Extract from the *Blue Book*) + +--- + +# NOTES + +1 ITU-T Recommendation T.390 was published in Fascicle VII.5 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below). + +2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# **TELETEX REQUIREMENTS FOR INTERWORKING WITH THE TELEX SERVICE** + +*(Malaga-Torremolinos, 1984)* + +## **1 General** + +### **1.1 Scope** + +1.1.1 Recommendation F.200 lays down the provisions for the operation of the automatic international Teletex service. In particular, Recommendation F.200 defines the basic service requirements and principles for interworking between Teletex and telex services via a conversion facility (CF). + +1.1.2 Recommendation T.60 defines the requirements for terminal equipment used in the international Teletex service, including the interworking with telex terminals, and the conversion table to the telex repertoire in case of interworking. + +1.1.3 Recommendation T.61 defines the character repertoire and the coded character sets for the Teletex service. + +1.1.4 Recommendation T.62 defines the end-to-end control procedures to be used within the Teletex service as well as between a Teletex terminal and a Teletex/telex conversion facility (CF). + +1.1.5 Recommendation T.70 defines the network-independent basic transport service applicable to Teletex terminals, as well as between a Teletex terminal and a CF. + +1.1.6 This Recommendation defines the requirements additional to Recommendation T.62 for use between a Teletex terminal and a CF to provide interworking between Teletex and telex services, using store-and-forward principles, in the following cases: + +- a) when the CF and Teletex terminal are in the same country, with message transfer in either direction; +- b) when the CF and Teletex terminal are in different countries, with message transfer in the CF to Teletex terminal direction. This is subject to bilateral agreement. + +*Note 1* – Due to practical operational difficulties such as charging, message transfer in the direction from a Teletex terminal to a CF in another country is not considered in this Recommendation. + +*Note 2* – The requirements of interconnection of CFs for the international interworking between Teletex and telex services are for further study. + +*Note 3* – The real-time conversion operation is not considered in this Recommendation. + +1.1.7 The provisions in this Recommendation are independent of the means and procedures for communication between the CF and the telex network. These are covered in Recommendation F.200. + +### **1.2 Basic Teletex/telex interworking model** + +1.2.1 As illustrated in Figure 1/T.390 and in the single-message case, the communications between a CF and a Teletex terminal for the transfer of a message from Teletex to telex may consist of two calls, namely: + +- a) a submission call initiated by a Teletex terminal to transfer to the CF a message prepared in the telex mode as per Recommendations F.200 and T.60, and related control information; +- b) a notification call initiated by the CF in which delivery or non-delivery information may be provided. This call is mandatory if the telex call is unsuccessful but optional if the telex call succeeds. + +![Diagram of interworking model with message transfer from Teletex to telex. A central box labeled 'Conversion facility (CF)' has two inputs from the left: 'Submission call' (solid arrow) and 'Notification call (see Note)' (dashed arrow). It has one output to the right: 'Telex call' (solid arrow). The diagram is labeled 'CCITT-59070'.](2763901b7a1fd1b5d704cdc450d12ed0_img.jpg) + +Diagram of interworking model with message transfer from Teletex to telex. A central box labeled 'Conversion facility (CF)' has two inputs from the left: 'Submission call' (solid arrow) and 'Notification call (see Note)' (dashed arrow). It has one output to the right: 'Telex call' (solid arrow). The diagram is labeled 'CCITT-59070'. + +**Note** — A notification call is mandatory if the telex call is unsuccessful but optional if the telex call succeeds (see § 4.3.1). + +FIGURE 1/T.390 + +**Interworking model with message transfer from Teletex to telex** + +1.2.2 As illustrated in Figure 2/T.390, the communications between a CF and a Teletex terminal for the transfer of a message from telex to Teletex may consist of two calls, namely: + +- a) an address validation call initiated by the CF to validate the called Teletex number. The requirement for this call is a national matter; +- b) a delivery call initiated by the CF to transfer to the Teletex terminal a message received from the telex terminal. + +![Diagram of interworking model with message transfer from telex to Teletex. A central box labeled 'Conversion facility (CF)' has two inputs from the left: 'Telex' (solid arrow) and 'Telex call' (solid arrow). It has two outputs to the right: 'Address validation call (see Note)' (dashed arrow) and 'Delivery call' (solid arrow). The diagram is labeled 'CCITT-59080'.](12a6537c92844d5b393104c02e8dfc2f_img.jpg) + +Diagram of interworking model with message transfer from telex to Teletex. A central box labeled 'Conversion facility (CF)' has two inputs from the left: 'Telex' (solid arrow) and 'Telex call' (solid arrow). It has two outputs to the right: 'Address validation call (see Note)' (dashed arrow) and 'Delivery call' (solid arrow). The diagram is labeled 'CCITT-59080'. + +**Note** — The requirement for this call is a national matter (see Figure 2/F.201). + +FIGURE 2/T.390 + +**Interworking model with message transfer from telex to Teletex** + +1.2.3 For transferring additional control information between the Teletex terminal and the CF, *control documents* are used. A control document may be associated with one or more normal documents. This set will be called a *message*. All these normal documents should be in telex mode and shall be delivered by the CF as a single *telex message*. The control document need not be prepared in telex mode. An acknowledgement control document will refer to a message and not to individual documents. + +## 2 Session elements of procedure + +2.1 The session elements of procedure shall be in accordance with Recommendation T.62. However, the following qualifications shall apply: + +2.1.1 The values of mandatory parameters used during session establishment shall be as given in Table 1/T.390. + +2.1.2 The value of the “terminal identifier of the calling terminal” parameter in the CSS of the delivery call depends on whether the CF and Teletex terminal are in the same or different countries. + +2.1.2.1 When the CF and Teletex terminal are in the same country, it may be either the terminal identification of the CF or, alternatively, the terminal identifier derived from the calling telex answerback (A/B) in one of the following forms in which optional fields are enclosed in parentheses: + +8 – = + +8 – = + +8 < TDC > – < A/B number > (– < A/B machine identity >) = (< A/B subscriber >) + +*Note 1* – is the value of the answerback received from the telex terminal after the deletion of the CR LF characters, if present. + +*Note 2* – < TDC > is the value of the Recommendation F.69 “telex destination code” of the originating network. + +*Note 3* – < A/B number > is the subscriber number part of the received < A/B >, as described in Note 1, which conforms to Recommendation F.60. + +*Note 4* – < A/B machine identity > is the optional machine identity part of the received < A/B >, as described in Note 1, which conforms to Recommendation F.60. + +*Note 5* – < A/B subscriber name > is the optional subscriber name part of the received < A/B >, as described in Note 1, which conforms to Recommendation F.60. This may also include the telex network identification code. + +TABLE 1/T.390 + +### **Mandatory parameter values during session establishment** + +| T.62 parameters | Call type | | | | +|------------------------------------------------------|--------------------------------------------------|---------------------------------------------------|---------------------------------------------------------|-----------------------------------------------| +| | Submission | Notification | Address validation | Delivery | +| Terminal identifier of the calling terminal (in CSS) | TTX's TID | CF's TID | CF's TID | See § 2.1.2 | +| Terminal identifier of the called terminal (in RSSP) | CF's TID | TTX's TID | TTX's TID | TTX's TID | +| Date and time | Submission call originating date and time by TTX | Notification call originating date and time by CF | Address validation call originating date and time by CF | Delivery call originating date and time by CF | +| Service identifier | Teletex | Teletex | Teletex | Teletex | + +TID Terminal Identification + +TTX Teletex Terminal + +CF Conversion facility + +2.1.2.2 When the CF and Teletex terminal are in different countries, it shall be the terminal identification of the CF in accordance to the format specified in Recommendation F.201. The calling telex answerback shall be contained in the text of the normal document in the format and at the point at which it was obtained by the CF. + +## 3 Document elements of procedures + +### 3.1 General + +3.1.1 The document elements of procedure shall be in accordance with Recommendation T.62. In addition, the Teletex terminal and the CF shall be able to handle control documents defined in this Recommendation as shown in Table 2/T.390. + +## 4 Control documents + +4.1 For transferring additional control information between the Teletex terminal and the CF, control documents are used. The additional control information is contained in the user information part of the control document and is called "control text". A summary of the control documents is given in Table 2/T.390. + +TABLE 2/T.390 + +Control documents for Teletex/telex interworking service + +| Type of call (see Figures 1/T.390 and 2/T.390) | Control document | Status of control document | | +|------------------------------------------------|------------------------------------------|----------------------------|----------------| +| | | CF | Telex terminal | +| Telex to telex message transfer | | | | +| Submission | Telex submission | Mandatory | Mandatory | +| Notification | Telex delivery notification (Note 2) | Mandatory | Selectable | +| | Telex non-delivery notification (Note 2) | Mandatory | Mandatory | +| Telex to telex message transfer | | | | +| Address validation | Telex validation (Note 1) | Optional | Optional | +| Delivery | Telex message delivery | Optional | Optional | + +Mandatory: Shall always be implemented. + +Optional: Shall be implemented according to national requirements. + +Selectable: To be implemented as appropriate. + +*Note 1* – An address validation call need not contain a telex validation control document. + +*Note 2* – At present, this only relates to a single telex address. + +### 4.2 Telex submission control document + +4.2.1 The Telex submission control document shall be used by the Teletex terminal to indicate to the CF that the associated subsequent normal document(s) is to be transferred to a telex terminal. + +4.2.2 Elements of the control text are: + +- control document identifier – mandatory; +- submission control information – optional. + +This element consists of the following parameters: + +- i) telex address – optional. + +This is the address of the recipient. It need not be present if provided in lower layer procedures; + +- ii) answerback – optional. + +This is the expected telex answerback. It is to be provided if automatic check by the CF is required; + +- iii) acknowledgement request – optional. + +This is the request for telex delivery notification. This parameter is only present if the user requires advice of a successful telex call. It need not be present in cases where the CF always provides delivery notification. + +4.2.3 This control document may be utilized in multi-addressing by providing several sets of the submission control information element in § 4.2.2 above. The provision of this capability in a CF is a national matter. + +*Note* – The inclusion of Teletex addresses within the multi-addressing list is for further study. + +4.2.4 Multiple telex submission control documents (each with associated normal documents) may be used within the same session. The provision of this capability in a CF is a national matter. + +### 4.3 *Telex delivery notification control document* + +4.3.1 If the Teletex user requires notification after the successful message transfer to the telex terminal [see § 4.2.2 b)], then the telex delivery notification control document shall be sent by the CF to the originator of the telex message. As a national matter, some CFs may always provide this delivery notification. + +#### 4.3.2 *Elements of the control text are:* + +- a) control document identifier — mandatory; +- b) correlation information — mandatory. + +This provides a unique reference to the corresponding telex submission control document. The element parameters which are provided by the CF are a national matter. These parameters are: + +- CF TID + +This is the terminal identification of the CF to which the corresponding telex submission control document was sent. + +- TTX TID + +This is the terminal identification of the Teletex terminal which sent the telex submission control document. + +- Date and time + +This is the date and time of the submission call. + +- CD No. + +This is the document reference number of the telex submission control document. + +- Add'l session Ref No. + +This is the additional session reference number if used in both the CSS and RSSP in the submission call; + +- c) submitted control information – mandatory. + +This reflects the relevant parameters of the telex submission control document pertaining to a single address. These parameters are: + +- telex address + +*Note* – This parameter can be derived from lower layer procedures if not present in the telex submission control document. + +- answerback + +- acknowledgement request; + +##### d) delivery information – mandatory. + +This provides information concerning call establishment from CF to the called telex terminal. The element parameters which are provided by the CF are a national matter. These parameters are: + +##### – telex address + +This is the address derived from the telex submission control document and used by the CF to establish the call. + +*Note* – This parameter can be derived from lower layer procedures if not present in the telex submission control document. + +###### – received answerback + +This is the complete telex answerback as received by the CF; + +##### e) time of delivery – optional. + +This is the time at which the CF delivered the telex message to the telex terminal; + +##### f) telex transmission duration – optional; + +##### g) note – optional. + +This is used to convey additional information; + +##### h) received recorded message – optional. + +This is used to convey to the Teletex terminal any recorded message from the telex destination. + +### 4.4 *Telex non-delivery notification control document* + +#### 4.4.1 The telex non-delivery notification control document shall be used in the following cases: + +##### a) if a telex message cannot be delivered; + +##### b) if a telex message was only partially delivered; + +##### c) if a message is incompletely received in the CF and this partial message successfully delivered (see § 6.1.2). + +#### 4.4.2 Elements of the control text are: + +##### a) control document identifier – mandatory; + +##### b) correlation information – mandatory [see § 4.3.2 b)]; + +##### c) submitted control information – mandatory [see § 4.3.2 c)]; + +##### d) delivery information – mandatory. + +This provides information concerning call attempt or call establishment. [For details of the parameters, see § 4.3.2 d)]; + +##### e) time of delivery – optional. + +This is the time at which the CF delivered the partial telex message to the telex terminal if a partial delivery was achieved; + +##### f) telex transmission duration - optional. + +This may be provided if a partial delivery was achieved; + +##### g) last page delivered - optional. + +This shall identify the last page number, and its document reference number, successfully transmitted to telex; + +##### h) failure cause - mandatory. + +The cause may be one of the following examples: + +###### – service signal from telex network; + +###### – clearing before call connect; + +###### – wrong answerback; + +###### – clear or break during message transmission; + +###### – submitted normal document not in the telex mode; + +- i) note – optional [see § 4.3.2 g)]; +- j) received recorded message – optional [see § 4.3.2 h)]. + +### 4.5 *Telex validation control document* + +4.5.1 The telex validation control document is used by the CF to indicate to the called Teletex terminal that a message from telex will subsequently be sent from the CF. The use of this control document is a national matter (e.g. for unique message identification) and shall not be allowed over international connections. + +4.5.2 Elements of the control text are: + +- a) control document identifier - mandatory; +- b) reference - mandatory. This reference is assigned by the CF. + +### 4.6 *Telex message delivery control document* + +4.6.1 The telex message delivery control document is used by the CF to indicate to the Teletex terminal that the associated subsequent normal document was received from a telex terminal. The use of this control document is a national matter. + +*Note* – The use of this control document over international connections requires further study. + +4.6.2 Elements of the control text are: + +- a) control document identifier – mandatory; +- b) reference – optional. +This reference is assigned by the CF. If the telex validation control document is used, then this reference must be quoted; +- c) received time – mandatory. +This contains the time at which the telex was received by the CF; +- d) received telex answerback – optional. +This is the complete telex answerback as received by the CF; +- e) Note – optional [see § 4.3.2 g)]. + +## 5 **General rules for control documents** + +### 5.1 *Control document utilization* + +Teletex terminals shall be capable of constructing messages, each consisting of a control document linked with a sequence of normal documents. The message ends at either the start of the next control document, or at the normal end of the session. + +5.1.1 The Teletex terminal will allow the following types of communication to a CF within a single session: + +- one or more normal documents covered by the same control document (“normal” documents shall be in the “telex” mode); +- one or more addresses covered by the same control document. The provision of this capability in a CF is a national matter; +- more than one control document and related normal documents in the same session. The provision of this capability in a CF is a national matter. + +5.1.2 When interworking with telex, the following rules shall apply (see Figure 3/T.390): + +- a control document relates to the normal documents which follow it, up to the next control document (if any) within the session, or up to the normal end of the session; +- the presence of more than one address in a control document indicates multi-addressing of all related normal documents; +- within a session, document reference numbers will be assigned, as specified in Recommendation T.62, without distinction between control documents and normal documents. + +![Diagram illustrating examples of types of communication (not exhaustive) within a session. The diagram shows two 'Message' blocks, each containing three rows of communication data. The first 'Message' block contains: 1. TELEX SUBMISSION (telex address = answerback + ACK) and CONTROL DOC (DOC REF 001); 2. (empty) and NORMAL DOC (DOC REF 002); 3. (empty) and NORMAL DOC (DOC REF 003). The second 'Message' block contains: 1. TELEX SUBMISSION (telex address = answerback + ACK, telex address = answerback, telex address + ACK, telex address) and CONTROL DOC (DOC REF 004); 2. (empty) and NORMAL DOC (DOC REF 005); 3. (empty) and NORMAL DOC (DOC REF 006). A large bracket on the right groups all these rows under the label 'Session'. The reference 'CCITT-50090' is at the bottom right.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +Diagram illustrating examples of types of communication (not exhaustive) within a session. The diagram shows two 'Message' blocks, each containing three rows of communication data. The first 'Message' block contains: 1. TELEX SUBMISSION (telex address = answerback + ACK) and CONTROL DOC (DOC REF 001); 2. (empty) and NORMAL DOC (DOC REF 002); 3. (empty) and NORMAL DOC (DOC REF 003). The second 'Message' block contains: 1. TELEX SUBMISSION (telex address = answerback + ACK, telex address = answerback, telex address + ACK, telex address) and CONTROL DOC (DOC REF 004); 2. (empty) and NORMAL DOC (DOC REF 005); 3. (empty) and NORMAL DOC (DOC REF 006). A large bracket on the right groups all these rows under the label 'Session'. The reference 'CCITT-50090' is at the bottom right. + +FIGURE 3/T.390 + +Examples of types of communication (not exhaustive) + +## 6 Error recovery in Teletex/telex interworking + +### 6.1 Message transfer from Teletex to telex + +6.1.1 During a session, the CF shall perform automatic linking using the procedures specified in T.62. + +6.1.2 In the case where a session interruption or CF memory overflow occurs, the following shall apply: + +- a) All complete messages received and positively acknowledged in that session shall be handled by the CF as in error-free operation. +- b) The CF shall handle the interrupted message in one of the following ways: + - The CF shall forward to the telex terminal all positively acknowledged documents and pages of the interrupted document, with an appropriate explanatory text. + +At the end of the text part which is transferred to telex an explanatory text is added, for example: + +“This is an incomplete telex message which may be continued later with the following reference information: + +< rearranged TTX terminal ID > < date and time >” + +At the end of the telex call, the CF may optionally transfer a telex non-delivery notification control document indicating the last page number, and its document reference number, which was successfully transferred to the telex network. + +- The CF shall not forward the interrupted message, but shall return a telex non-delivery notification control document to the Teletex terminal to indicate that the complete message has to be retransmitted to the CF. +- c) Additionally, in the case of the interrupted message: + - the reaction of the CF is independent of the acknowledgement request of the telex submission control document; + - if a CF in case of interrupted message always sends a telex non-delivery notification, a Teletex terminal or operator should not retransmit any part of that message before receiving that notification. + +6.1.3 When the CF is not able to forward the telex message (e.g. because of line interruption) to the telex network, it shall transfer to the Teletex terminal a telex non-delivery notification control document. + +6.1.4 If the Teletex terminal retransmits an interrupted message in a new session, it shall send as the first document the control document relating to the interrupted message. When the Teletex operator wants to indicate to the telex terminal that this transmission is a continuation of an interrupted one, the Teletex terminal shall always start the interrupted normal document with CDC. When delivering this message to the telex network, the CF shall precede the continuation of the transmitted message with an appropriate explanatory text, for example “This is a continuation of an incomplete message with the following reference information: + +< rearranged TTX terminal ID > < date and time > ” + +*Note* – Both parameters of the reference information are taken from the linking information of the CDC command and are identical to the parameters described in § 6.1.2 b). + +### 6.2 Message transfer from telex to Teletex + +6.2.1 For error conditions arising during the Teletex call, normal error recovery procedures in Recommendation T.62 shall apply. + +6.2.2 If an error was detected during telex input, the CF shall add to the end of the interrupted telex message an appropriate explanatory text. An example is “This may be an incomplete message”. + +This explanatory text may also be used if the telex call was cleared before the CF received the end of input signal (EOI). + +## 7 Coding and formatting of control documents + +### 7.1 Control document structure + +7.1.1 Figure 4/T.390 illustrates the structure of control documents. The user information part of the control document user information (CDUI) in control documents is called *control text*. + +![Diagram illustrating the structure of control documents. The diagram shows a vertical stack of fields: CDS, Document reference number, Document type identifier (= control document), a dashed line indicating non-mandatory parameters, CDUI, and CDE. Brackets on the left group the first four fields as 'Control document' and the last two as 'Control text'. A bracket on the right groups the dashed line and CDUI as 'Non-mandatory parameters'.](b3c108e7145f2017957569d06ea359cb_img.jpg) + +The diagram illustrates the structure of control documents. It shows a vertical stack of fields: + +- CDS +- Document reference number +- Document type identifier (= control document) +- A dashed line indicating non-mandatory parameters. +- CDUI +- CDE + +Brackets on the left group the first four fields as "Control document" and the last two as "Control text". A bracket on the right groups the dashed line and CDUI as "Non-mandatory parameters". + +CCITT-59100 + +Diagram illustrating the structure of control documents. The diagram shows a vertical stack of fields: CDS, Document reference number, Document type identifier (= control document), a dashed line indicating non-mandatory parameters, CDUI, and CDE. Brackets on the left group the first four fields as 'Control document' and the last two as 'Control text'. A bracket on the right groups the dashed line and CDUI as 'Non-mandatory parameters'. + +FIGURE 4/T.390 +Structure of control documents + +### 7.2 Control document coding principles + +7.2.1 For the basic Teletex/telex interworking service, the control text shall be coded using explicit, human-readable graphic characters of Recommendation T.61 coding scheme. + +### 7.3 General formatting of control text + +7.3.1 The control text is subdivided in *elements* each consisting of a number of *fields*. + +7.3.2 An element is uniquely identifiable by an *element number* field, which is language-independent, and an *element name* field, which is language dependent. These two fields are always closed by the character “colon” (:). In control documents sent by the CF to the Teletex terminal, at least one of the above fields must be present. For international communications, the element number field shall be mandatory. + +7.3.2.1 The element number assigned to the control document identifier shall consist of two parts separated by a period. Each part is a sequentially assigned number. The first part identifies the application which uses the control document. The second part identifies the control document. + +7.3.2.2 Each distinct element name, other than control document identifiers, shall be sequentially assigned a different number. + +7.3.2.3 There shall be no restriction on the number of digits for element numbers. Any leading zeros in an element number are ignored. + +7.3.2.4 Where national requirements dictate the use of non-standardized element numbers, Administrations may choose any value in the range 1000-1999 for the first part of non-standardized control document identifiers and for non-standardized elements. + +7.3.3 Parameters to the elements shall be coded in separate *element value* fields. + +The parameters will be illustrated in this Recommendation by enclosing them between angular brackets (<>). + +7.3.4 In the text each element is contained in one or more lines. When more than one line is used, only the element number field and the element name field shall be present in the first line. See Figure 5/T.390. + +![Figure 5/T.390: Formats of the elements. The diagram shows four possible formats for an element, separated by 'or'. Format 1: A box labeled 'Element No. field' followed by a box with a colon, then 'SP', then a box labeled 'Element name field' followed by a box with a colon, then 'SP', then a box labeled 'Element value field', then 'SP', then another box labeled 'Element value field', and finally '...'. Format 2: A box labeled 'Element No. field' followed by a box with a colon, then 'SP', then a box labeled 'Element name field' followed by a box with a colon, then '"New line function"'. Format 3: A box labeled 'Element value field', then 'SP', then another box labeled 'Element value field', then 'SP ... "New line function"'. Format 4: A box labeled 'Element value field', then 'SP ...'. A legend at the bottom states 'SP = Separator'. The text 'CCITT-59 110' is in the top right corner.](5a95b187de0044da69b7322e04761b86_img.jpg) + +Element No. field : SP Element name field : SP Element value field SP Element value field ... + +or + +Element No. field : SP Element name field : "New line function" + +Element value field SP Element value field SP ... "New line function" + +Element value field SP ... + +SP = Separator + +CCITT-59 110 + +Figure 5/T.390: Formats of the elements. The diagram shows four possible formats for an element, separated by 'or'. Format 1: A box labeled 'Element No. field' followed by a box with a colon, then 'SP', then a box labeled 'Element name field' followed by a box with a colon, then 'SP', then a box labeled 'Element value field', then 'SP', then another box labeled 'Element value field', and finally '...'. Format 2: A box labeled 'Element No. field' followed by a box with a colon, then 'SP', then a box labeled 'Element name field' followed by a box with a colon, then '"New line function"'. Format 3: A box labeled 'Element value field', then 'SP', then another box labeled 'Element value field', then 'SP ... "New line function"'. Format 4: A box labeled 'Element value field', then 'SP ...'. A legend at the bottom states 'SP = Separator'. The text 'CCITT-59 110' is in the top right corner. + +FIGURE 5/T.390 + +Formats of the elements + +7.3.5 The first element present in the control text shall be the control document identifier. This element is mandatory and used to identify the function of the control document, e.g. submission of a telex message, acknowledgement of a previous message. + +7.3.6 The element denoted by the name “Note” will be allowed for extending the format to accommodate national requirements. + +7.3.7 An element name shall be represented by a *text string*, that is, a sequence of graphic characters. Some parameters may also consist of such text strings. All text strings are language-dependent. + +7.3.8 When encoding the control text the following rules shall apply: + +- a) The control text shall always begin with the character sequence FF CR or CR FF preceded by applicable presentation control functions (see Recommendation T.61, § 3.3.1.4). +- b) Each element following the control document identifier may be preceded by one or more empty lines. +- c) Each field in an element shall be separated by the character "space" if no other special separator is defined for the element. + +*Note* – It is allowed to have leading spaces or backspaces in a line. + +7.3.9 When decoding the control text the following rules shall apply: + +- a) The first element in the text shall be recognized as the control document identifier. Leading New Line functions (CR LF or LF CR), LF and leading spaces shall be ignored. +- b) Contiguous New Line functions (CR LF or LF CR) or LF shall be considered as *one* New Line function. +- c) Contiguous embedded spaces are considered as one space. Leading spaces in a line shall be ignored. + +*Note* – Leading backspaces in a line shall be ignored. + +### 7.4 *Format of Teletex/telex interworking control documents* + +In this section the formats of the different control documents are shown. Their control texts are illustrated by the use of four different syntax elements: + +- The element number field is represented by a sequence of numeric graphic characters. +- The element name field is represented by a text string giving the CCITT language reference name of the field. The actual value shall be a language-dependent representation of that reference name. +- Separators [i.e.: (SP13), / (SP12), = (SA04)] are shown as they shall be represented in the actual control text. +- Element value fields are shown in angular brackets (< >). The actual parameter values are described in § 7.5. + +The formats are illustrated in terms of layout and contents, but do not explicitly show the presentation control functions. These shall be inserted as appropriate (see § 7.3.8). + +#### 7.4.1 *Telex submission control document format* + +7.4.1.1 Figure 6/T.390 illustrates the format of the control text in the telex submission control document. + +1.1:        **TELEX SUBMISSION:** +              <=ANSWERBACK> <+ACKNOWLEDGEMENT REQUEST> + +**FIGURE 6/T.390** +**Telex submission control document** + +7.4.1.2 The submission control information element does not have an explicit identification. + +#### 7.4.2 *Telex delivery notification control document format* + +7.4.2.1 Figure 7/T.390 illustrates the format of the control text in the telex delivery notification control document. + +- 1.2:     TELEX DELIVERY NOTIFICATION: +- 1:       CORRELATION INFORMATION: +            +- 2:       SUBMITTED CONTROL INFORMATION: +            <=ANSWERBACK> <+ACKNOWLEDGEMENT REQUEST> +- 3:       DELIVERY INFORMATION: +            = +- 4:       TIME OF DELIVERY: +- 5:       TELEX TRANSMISSION DURATION: +- 6:       NOTE: +- 7:       RECEIVED RECORDED MESSAGE: +            + +*Note* — If is 5 digits long, and is used, the correlation information line will be 73 characters long. A backspace into the left margin is then necessary, in order not to exceed the printable area of a basic Teletex terminal. + +FIGURE 7/T.390 + +##### **Telex delivery notification control document** + +#### 7.4.3 *Telex non-delivery notification control document format* + +7.4.3.1 Figure 8/T.390 illustrates the format of the control text in the telex non-delivery notification control document. + +- 1.3:     TELEX NON-DELIVERY NOTIFICATION: +- 1:       CORRELATION INFORMATION: +            / / / / +- 2:       SUBMITTED CONTROL INFORMATION: +            <=ANSWERBACK> <+ACKNOWLEDGEMENT REQUEST> +- 3:       DELIVERY INFORMATION: +            = +- 4:       TIME OF DELIVERY: +- 5:       TELEX TRANSMISSION DURATION: +- 8:       LAST PAGE DELIVERED: DOCUMENT = PAGE = +- 9:       FAILURE CAUSE: +- 6:       NOTE: +- 7:       RECEIVED RECORDED MESSAGE: +            + +*Note* — See Note of Figure 7/T.390. + +FIGURE 8/T.390 + +##### **Telex non-delivery notification control document** + +#### 7.4.4 *Telex validation control document format* + +7.4.4.1 Figure 9/T.390 illustrates the format of the control text in the telex validation control document. + +1.4:      **TELEX VALIDATION:** +10:      **REFERENCE: ** + +**FIGURE 9/T.390** +**Telex validation control document** + +#### 7.4.5 *Telex message delivery control document format* + +7.4.5.1 Figure 10/T.390 illustrates the format of the control text in the telex message delivery control document. + +1.5:      **TELEX MESSAGE DELIVERY:** +10:      **REFERENCE: ** +11:      **RECEIVED TIME: ** +12:      **RECEIVED TELEX ANSWERBACK: ** +6:      **NOTE: ** + +**FIGURE 10/T.390** +**Telex message delivery control document** + +### 7.5 *Description of parameter values in Teletex/telex interworking control documents* + +#### 7.5.1 + +A sequence of numeric graphic characters. As a national option, a limited set of graphic characters may be allowed to be embedded in this field as punctuation marks. + +#### 7.5.2 <= ANSWERBACK> + +An equals sign graphic character followed by a sequence of alphanumeric graphic characters which comprise part or all of the expected answerback code. The carriage return and line feed characters shall not occur in this parameter. + +#### 7.5.3 <+ ACKNOWLEDGEMENT REQUEST> + +A plus sign graphic character followed by the text string "ACK". + +#### 7.5.4 + +A sequence of graphic characters as defined in Figure 2/F.200. + +#### 7.5.5 + +A sequence of graphic characters as defined in Figure 2/F.200. + +#### 7.5.6 + +A sequence of graphic characters as defined in Figure 1/F.200. + +#### 7.5.7 + +A document reference number as specified in Recommendation T.62. + +#### 7.5.8 + +An additional session reference number as specified in Recommendation T.62. + +#### 7.5.9 + +A sequence of graphic characters representing a telex answerback code from which CR LF characters have been deleted, if present. + +#### 7.5.10 + +A sequence of graphic characters in the form "HH : MM : SS" representing the numeric values in hours, minutes and seconds. + +#### 7.5.11 + +Any text string coded as in Recommendation T.61. + +#### 7.5.12 + +A document reference number as specified in Recommendation T.62 with a length not exceeding five digits. + +#### 7.5.13 + +A page reference number as specified in Recommendation T.62 with a length not exceeding five digits. + +#### 7.5.14 < CAUSE > + +This is a text string with the following possible values – the list is not exhaustive: + +- network service signal as received from the telex network (see Recommendation U.12) or/and a corresponding text string in the appropriate language; +- error in submitted control document; +- invalid telex address; +- not delivered – interruption in the transmission; +- submitted text not prepared for telex; +- not permitted telex answerback; +- procedural error during the submission call. + +#### 7.5.15 + +An alphanumeric text string. \ No newline at end of file diff --git a/marked/T/T-REC-T.411-199303-I_PDF-E/raw.md b/marked/T/T-REC-T.411-199303-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..192a464af4d6faead98a39621ca762254a7f52d0 --- /dev/null +++ b/marked/T/T-REC-T.411-199303-I_PDF-E/raw.md @@ -0,0 +1,3072 @@ + + +![ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol below it.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol below it. + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**T.411** + +(03/93) + +**TELEMATIC SERVICES** + +**TERMINAL EQUIPMENTS AND PROTOCOLS +FOR TELEMATIC SERVICES** + +--- + +**INFORMATION TECHNOLOGY – OPEN +DOCUMENT ARCHITECTURE (ODA) +AND INTERCHANGE FORMAT: +INTRODUCTION AND GENERAL PRINCIPLES** + +**ITU-T Recommendation T.411** + +--- + +# Foreword + +ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. Some 179 member countries, 84 telecom operating entities, 145 scientific and industrial organizations and 38 international organizations participate in ITU-T which is the body which sets world telecommunications standards (Recommendations). + +The approval of Recommendations by the Members of ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, 1993). In addition, the World Telecommunication Standardization Conference (WTSC), which meets every four years, approves Recommendations submitted to it and establishes the study programme for the following period. + +In some areas of information technology, which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. The text of ITU-T Recommendation T.411 was approved by the WTSC (Helsinki, March 1-12, 1993). The identical text is also published as ISO/IEC International Standard 8613-1. + +# --- NOTES + +1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector. + +In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms "CCITT, CCIR or IFRB" or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. + +2 In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# CONTENTS + +| | Page | +|--------------------------------------------------------------------------------------------|-------------| +| Introduction ..... | iv | +| 1 Scope ..... | 1 | +| 2 Normative references ..... | 1 | +| 2.1 Identical Recommendations International Standards ..... | 2 | +| 2.2 Paired Recommendations International Standards equivalent in technical content ..... | 2 | +| 2.3 Additional references ..... | 2 | +| 3 Definitions ..... | 3 | +| 4 Abbreviations ..... | 12 | +| 5 Conventions ..... | 13 | +| 5.1 Names of attributes and parameters ..... | 13 | +| 5.2 Names of attribute and parameter values ..... | 13 | +| 5.3 Component and component description ..... | 13 | +| 5.4 Introduction of terms ..... | 13 | +| 5.5 Representation of degrees ..... | 14 | +| 6 General concept of ODA ..... | 14 | +| 6.1 Purpose of ODA ..... | 14 | +| 6.2 Overall concept of ODA ..... | 14 | +| 6.2.1 Logical structure and layout structure ..... | 14 | +| 6.2.2 Content portions ..... | 16 | +| 6.2.3 Content architectures ..... | 16 | +| 6.2.4 Attributes ..... | 17 | +| 6.2.5 Relations between logical structure and layout structure ..... | 17 | +| 6.2.6 Specific and generic structures ..... | 17 | +| 6.2.7 Document profile ..... | 19 | +| 6.2.8 Generic-document ..... | 19 | +| 6.2.9 Protected parts ..... | 19 | +| 6.3 Document processing model ..... | 19 | +| 6.3.1 Relationships of ODA to document processing ..... | 19 | +| 6.3.2 Editing process ..... | 19 | +| 6.3.3 Layout process ..... | 19 | +| 6.3.4 Imaging process ..... | 20 | +| 7 Overview of the ITU-T Rec. T.410-Series ISO/IEC 8613 ..... | 20 | +| 7.1 ITU-T Rec. T.411 ISO/IEC 8613-1: Introduction and general principles ..... | 20 | +| 7.2 ITU-T Rec. T.412 ISO/IEC 8613-2: Document structures ..... | 21 | +| 7.3 ITU-T Rec. T.414 ISO/IEC 8613-4: Document profile ..... | 21 | +| 7.4 ITU-T Rec. T.415 ISO/IEC 8613-5: Open document interchange format ..... | 21 | +| 7.5 ITU-T Rec. T.416 ISO/IEC 8613-6: Character content architectures ..... | 21 | +| 7.6 ITU-T Rec. T.417 ISO/IEC 8613-7: Raster graphics content architectures ..... | 21 | +| 7.7 ITU-T Rec. T.418 ISO/IEC 8613-8: Geometric graphics content architectures ..... | 22 | +| 7.8 ISO/IEC 8613-10: Formal specifications ..... | 22 | +| 8 Inter-dependencies of the Specifications ..... | 22 | +| 9 Conformance ..... | 23 | + +| | Page | +|---------------------------------------------------------------------------|-------------| +| 10 Document application profile ..... | 23 | +| 10.1 General principles for defining a document application profile ..... | 24 | +| 10.2 Rules for defining a document application profile ..... | 24 | +| 10.2.1 Rules for defining a document architecture class ..... | 24 | +| 10.2.2 Rules for defining a content architecture class ..... | 25 | +| 10.2.3 Rules for defining a document profile ..... | 27 | +| 10.2.4 Rules for selecting the interchange format class ..... | 27 | + +# LIST OF FIGURES + +| | Page | +|-------------------------------------------------------------------------------|-------------| +| Figure 1 – Example of a logical view of a document ..... | 15 | +| Figure 2 – Possible correspondence between logical and layout objects ..... | 16 | +| Figure 3 – Example of a page layout ..... | 18 | +| Figure 4 – Basic document processing model ..... | 20 | +| Figure G.1 – Data stream conformance to ITU-T Rec. T.410 ISO/IEC 8613 ..... | 76 | + +# LIST OF TABLES + +| | | +|------------------------------------------------------------|----| +| Table F.1 – List of attributes and data types ..... | 57 | +| Table F.2 – List of control functions and data types ..... | 74 | + +# Introduction + +This ITU-T Recommendation | International Standard was prepared as a joint publication by TSS Study Group 8 and ISO/IEC Joint Technical Committee 1. + +At present, the ITU-T series of Recommendations in the T.410-Series | International Standard ISO/IEC 8613 consists of: + +- Introduction and general principles; +- Document structures; +- Document profile; +- Open document interchange format; +- Character content architectures; +- Raster graphics content architectures; +- Geometric graphics content architectures; +- Formal specifications. + +(The formal specification is applicable to ISO/IEC 8613 only.) + +Further Recommendations | International Standards may be added to this series of ITU-T Recommendations | International Standard. + +Development of this series of ITU-T Recommendations | International Standards was originally in parallel with the ECMA 101 standard: *Open Document Architecture*. + +This series of ITU-T Recommendations | International Standards is a new edition of the CCITT T.410-Series of Recommendations (1988) and ISO/IEC 8613 (1989). + +Significant technical changes are the inclusion of the following amendments as agreed by TSS and ISO/IEC: + +- Alternative representation +- Annex on use of MHS/MOTIS +- Colour +- Conformance Testing annex +- Document Application Profile Proforma and Notation +- Security +- Streams +- Styles +- Tiled raster graphics + +In addition, a number of technical corrigenda have been applied to this series of ITU-T Recommendations | International Standard. + +This ITU-T Recommendation | International Standard contains eight annexes: + +- Annex A (non-integral) gives references to other standards and registers; +- Annex B (non-integral) gives the relationship of this series of ITU-T Recommendations | International Standards with other CCITT Recommendations and International Standards; +- Annex C (integral) specifies the method of recording documents in conformance with this series of ITU-T Recommendations | International Standards on volume and file structures of interchangeable storage media in conformance with international standards for volume and file structures; + +- Annex D (integral) gives the principles for the assignment of ASN.1 object identifier values for this series of ITU-T Recommendations | International Standards; +- Annex E (integral) describes the use of MHS to interchange documents conforming to this series of ITU-T Recommendations | International Standards; +- Annex F (non-integral) defines a standardized proforma for the specification of document application profiles based on this series of ITU-T Recommendations | International Standards; +- Annex G (non-integral) gives directions for the development of a conformance testing methodology for this series of ITU-T Recommendations | International Standards. + + + +## INTERNATIONAL STANDARD + +###### ITU-T RECOMMENDATION + +## INFORMATION TECHNOLOGY – OPEN DOCUMENT ARCHITECTURE (ODA) AND INTERCHANGE FORMAT: INTRODUCTION AND GENERAL PRINCIPLES + +# 1 Scope + +The purpose of the ITU-T Rec. T.410-Series | ISO/IEC 8613 is to facilitate the interchange of documents. + +In the context of these Recommendations | International Standards, documents are to be items such as memoranda, letters, invoices, forms and reports, which may include pictures and tabular material. The content elements used within the documents may include graphic characters, raster graphics elements, and geometric graphics elements, all potentially within one document. + +NOTE – These Recommendations | International Standards are designed to allow for extensions, including hypermedia features, spreadsheets and additional types of content such as audio and video. + +In addition to content types defined in these Recommendations | International Standards, ODA also provides for arbitrary content types to be included in documents. + +These Recommendations | International Standards apply to the interchange of documents by means of data communications or the exchange of storage media. + +These Recommendations | International Standards provide for the interchange of documents for either or both of the following purposes: + +- to allow presentation as intended by the originator; +- to allow processing, such as editing and reformatting. + +The composition of a document in interchange can take several forms: + +- formatted form, allowing presentation of the document; +- processable form, allowing processing of the document; +- formatted processable form, allowing both presentation and processing of the document. + +These Recommendations | International Standards also provide for the interchange of ODA information structures used for the processing of interchanged documents. + +This ITU-T Recommendation | International Standard: + +- introduces this ITU-T T.410-Series of Recommendations | ISO/IEC 8613 as a whole; +- gives the references necessary for the ITU-T T.410-Series of Recommendations | ISO/IEC 8613; +- defines terms used in the context of the ITU-T T.410-Series of Recommendations | ISO/IEC 8613; +- presents the concepts of the document architecture; +- gives an overview of the ITU-T T.410-Series of Recommendations | ISO/IEC 8613; +- describes the inter-dependencies of the ITU-T T.410-Series of Recommendations | ISO/IEC 8613; +- defines conformance to the ITU-T T.410-Series of Recommendations | ISO/IEC 8613; +- gives rules for defining document application profiles. + +# 2 Normative references + +The following ITU-T/CCITT Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The TSS Secretariat maintains a list of the currently valid ITU-T/CCITT Recommendations. + +## 2.1 Identical Recommendations | International Standards + +- ITU-T Recommendation T.412 (1992) | ISO/IEC 8613-2:1993, *Information technology – Open Document Architecture (ODA) and interchange format: Document structures.* +- ITU-T Recommendation T.414 (1992) | ISO/IEC 8613-4:1993, *Information technology – Open Document Architecture (ODA) and interchange format: Document profile.* +- ITU-T Recommendation T.415 (1992) | ISO/IEC 8613-5:1993, *Information technology – Open Document Architecture (ODA) and interchange format: Open Document Interchange Format.* +- ITU-T Recommendation T.416 (1992) | ISO/IEC 8613-6:1993, *Information technology – Open Document Architecture (ODA) and interchange format: Character content architectures.* +- ITU-T Recommendation T.417 (1992) | ISO/IEC 8613-7:1993, *Information technology – Open Document Architecture (ODA) and interchange format: Raster graphics content architectures.* +- ITU-T Recommendation T.418 (1992) | ISO/IEC 8613-8:1993, *Information technology – Open Document Architecture (ODA) and interchange format: Geometric graphics content architectures.* + +## 2.2 Paired Recommendations | International Standards equivalent in technical content + +- CCITT Recommendation X.208 (1988), *Specification of Abstract Syntax Notation One (ASN.1).* +ISO/IEC 8824:1990, *Information technology – Open Systems Interconnection – Specification of Abstract Syntax Notation One (ASN.1).* +- CCITT Recommendation X.209 (1988), *Specification of basic encoding rules for Abstract Syntax Notation One (ASN.1).* +ISO/IEC 8825:1990, *Information technology – Open Systems Interconnection – Specification of Basic Encoding Rules for Abstract Syntax Notation One (ASN.1).* +- CCITT Recommendation X.411 (1992), *Message Handling Systems: Message Transfer System: Abstract Service Definition and Procedures.* +ISO/IEC 10021-4:1990, *Information technology – Text Communication – Message Oriented Text Interchange Systems (MOTIS) – Part 4: Message Transfer System: Abstract Service Definition and Procedures.* +- CCITT Recommendation X.420 (1992), *Message Handling Systems: Message Transfer System: Interpersonal Messaging System.* +ISO/IEC 10021-7:1990, *Information technology – Text Communication – Message Oriented Text Interchange Systems (MOTIS) – Part 7: Interpersonal Messaging System.* + +## 2.3 Additional references + +- ISO 2022:1986, *Information processing – ISO 7-bit and 8-bit coded character sets – Code extension techniques.* +- ISO/IEC 8613-10:1991, *Information processing – Text and office systems – Office Document Architecture (ODA) and interchange format – Part 10: Formal specifications.* +- ISO/IEC 8632-1:1992, *Information technology – Computer graphics – Metafile for the storage and transfer of picture description information – Part 1: Functional specification.* +- ISO/IEC 8632-3:1992, *Information technology – Computer graphics – Metafile for the storage and transfer of picture description information – Part 3: Binary encoding.* +- ISO 8879:1986, *Information processing – Text and office systems – Standard Generalized Markup Language (SGML).* +- ISO 9069:1988, *Information processing – SGML support facilities – SGML Document Interchange Format (SDIF).* +- ISO 9293:1987, *Information processing – Volume and file structure of flexible disk cartridges for information interchange.* +- ISO/IEC 9541-1:1991, *Information technology – Font information interchange – Part 1: Architecture.* +- ISO 9660:1988, *Information processing – Volume and file structure of CD-ROM for information interchange.* + +# 3 Definitions + +For the purposes of this Recommendation | International Standard, the following definitions apply. + +- 3.1 active position:** The point at which the action specified by the next character is to be effected. +- 3.2 aligned around:** A tabulation alignment that positions the sequence of character images for a specified character string such that the position point of the character image of the first instance of a specified group of characters within that string is positioned at the tabulation stop. +- 3.3 alternative description:** A description that represents a basic object that is intended to be used by the recipient in lieu of the primary description of that basic object when the primary description cannot be processed. +- 3.4 alternative subtree:** An alternative basic object description in conjunction with its associated content portion descriptions. +- 3.5 aspect ratio:** The ratio of the dimension of a pel array in the direction of the pel path to the dimension in the direction of the line progression. +- 3.6 assured reproduction area:** The rectangular area that remains on the nominal page after deducting an agreed allowance for edge losses. +- 3.7 attribute:** An element of a constituent of a document that has a name and a value and that expresses a characteristic of this constituent or a relationship with one or more constituents. +- 3.8 authenticity:** The property that the claimed data source can be verified to the satisfaction of the recipient. +- 3.9 available area:** The area determined by the document layout process into which the content portion is formatted by the content layout process. +- 3.10 basic component:** A basic logical or layout object, or an object class from which basic logical or layout objects may be derived. +- 3.11 basic layout object:** An object in the specific layout structure that has no subordinate. +- 3.12 basic logical object:** An object in the specific logical structure that has no subordinate. +- 3.13 basic measurement unit; BMU (abbreviation):** A unit of linear measurement equal to 1/1200 of 25,4 mm. +NOTE – A locally defined scaling factor may be used to map the document to a particular imaging device. +- 3.14 basic value:** An attribute value, a control function parameter value or the value of any other capability that is unconditionally allowed in document interchange in the context of a given document application profile. +- 3.15 binding:** A pair comprising an identifier and a value, where the value may be of any type, may be specified by an expression, and is accessed through use of the binding identifier. +- 3.16 block:** A basic layout component that corresponds to a rectangular area within a frame or a page. +- 3.17 bottom edge:** The edge of the positioning area of a basic layout object that is in the direction of the line progression. +- 3.18 bottom left corner:** The corner of a layout object that is least progressed in the horizontal direction and most progressed in the vertical direction of a layout object. +- 3.19 bottom right corner:** The corner of a layout object that is most progressed both in the horizontal and vertical directions of a layout object. +- 3.20 centred:** +- a) The result of a layout or imaging process that positions the sequence of character images for a line such that the distance from the line home position to the position point of the first character image is approximately equal to the distance from the escapement point of the last character image to the end edge of the positioning area. + - b) A tabulation alignment that positions the sequence of character images for a specified character string such that the distance from the position point of the first character image to the tabulation stop is approximately equal to the distance from the tabulation stop to the escapement point of the last character image. +- NOTE – The term *centred* is also used as a value in the sub-parameter “alignment” of the parameter “position” and in the attribute “block alignment”. +- 3.21 character:** A member of a set of elements used for the organization, control and representation of information. + +- 3.22 character base line:** A line across a character image, in the horizontal direction when the character image is in its intended viewing orientation. +- 3.23 character image:** The human perceptible rendering of a character on a presentation medium. +NOTE – The term *glyph* in ISO/IEC 9541 is equivalent to the term *character image* in this Specification. +- 3.24 character orientation:** The direction of the character base line relative to the characters. +- 3.25 character path:** The direction of progression of successive character images within a line box. +- 3.26 character sequence:** A sequence of characters intended to be presented as one or more lines. +- 3.27 character spacing (for constant spacing fonts only):** The distance between the position points of successive character images when the inter-character space equals zero. +- 3.28 clipped pel array:** The actual pel array to be imaged as determined by taking account of all clipping parameters. +- 3.29 colour component:** One of the dimensions of a colour space. +- 3.30 colour gamut:** The range of colours a given system is capable of reproducing. +- 3.31 complete generator set:** A constituent of a document consisting of a document root object class description and at least one level of subordinate object class descriptions which are used to control the creation and/or modification of the set of object descriptions representing a corresponding specific structure. +- 3.32 component:** An object or an object class. +- 3.33 composite component:** A composite logical or layout object, or an object class from which composite logical or layout objects may be derived. +- 3.34 composite layout object:** An object in the layout structure that has one or more subordinate objects. +- 3.35 composite logical object:** An object in the logical structure that has one or more subordinate objects. +- 3.36 confidentiality:** The property that information is not made available or disclosed to unauthorized individuals, entities or processes. +NOTE – This property is limited here to preventing unauthorized semantic knowledge of a document or specified parts of it. +- 3.37 constant spacing:** The characteristic of a font wherein the distance between the position point and the escapement point is the same for all character images. +- 3.38 constituent:** A set of attributes that is one of the following types: a document profile, an object description, an object class description, a presentation style, a layout style, a content portion description or a protected part description. +- 3.39 content:** The information conveyed by the document, other than the structural information, and that is intended for human perception. +- 3.40 content architecture:** Rules for defining the internal structure and representation of the content of basic components in terms of a set of content elements, attributes and control functions, and guidelines for the presentation of the content. +- 3.41 content architecture class:** The rules for defining the internal structure and representation of the content of basic components in one of a set of forms defined for each type of content element. +NOTE – Examples of content architecture classes are formatted form, processable form and formatted processable form in the case of character content elements. +- 3.42 content editing process:** The process that creates new content or modifies previous content. +- 3.43 content element:** A basic element of the content of a document. +- 3.44 content layout process:** The process that, interacting with the document layout process, consists of the formatting of content portions into available areas and the determination of the sizes of blocks in accordance with information contained in the presentation styles. +- 3.45 content portion:** The result of partitioning the content of a document according to its logical and/or layout structure. +- 3.46 content portion description:** A constituent of a document, representing a content portion that consists of content information and attributes to specify the properties of its content information. + +- 3.47 content type:** A category of content elements such as graphic characters, raster graphic elements and geometric graphic elements. +- 3.48 control function:** An element of a character set that affects the recording, processing, transmission or interpretation of data, and that has a coded representation consisting of one or more bit combinations. +- NOTE – Examples of control functions are Selected Graphic Rendition (SGR) in character content architectures and Set Line Type in geometric graphics content architectures. +- 3.49 current layout position:** The identification of a lowest level frame which is maintained during the layout process for each layout stream which occurs. +- 3.50 Cyan Magenta Yellow (Black); CMY(K) (abbreviation) colour space:** Colour space based on the subtractive colour mixture of Cyan (C), Magenta (M) and Yellow (Y) primaries with the optional inclusion of Black (K) as indicated by the parentheses. +- 3.51 DAP-*n* data stream:** An ODA data stream in which the data elements are in accordance with a particular document application profile named *n*, defined in accordance with this Specification. +- 3.52 data integrity:** The property that data has not been altered or destroyed. +- 3.53 data structure:** A set of data items and the relationship between them representing the whole or a part of a constituent. +- NOTE – The data items constituting a data structure represent attributes of the document, the document profile, the components, the styles, or the content portions concerned. +- 3.54 description:** A constituent that corresponds to a structural element. +- NOTE – A basic object may have several descriptions when alternative descriptions are used. +- 3.55 descriptor:** A data structure representing the document profile, an object class description, a layout style, a presentation style, an object description, or a protected part description. +- 3.56 device space:** A colour space where the coordinates are those used by a particular device in the measurement or rendition of colour. +- 3.57 digital signature:** A form of seal associated with a specified part of a document which provides proof of uniqueness of the identity of the originator (source) who applied the seal; it supports non-repudiation of origin of the sealed (signed) part. +- 3.58 document:** A structured amount of information intended for human perception, that may be interchanged as a unit between users and/or systems. +- 3.59 document application profile:** The specification of a combination of features defined in ITU-T Rec. T.410-Series | ISO/IEC 8613, intended to form a subset to fulfil the requirements of an application. +- 3.60 document architecture:** +- a) Rules for defining the structure of documents, in terms of collections of constituents and the attributes of which these are composed. + - b) The structural information of a document consisting of the set of one or more of the following structures: specific logical structure, specific layout structure, generic logical structure and/or generic layout structure together with presentation styles and/or layout styles. +- 3.61 document architecture class:** The rules for defining the structure and representation of documents in formatted form, processable form or formatted processable form. +- 3.62 document body:** The part of a document that may include a generic logical and layout structure, specific logical and layout structure, layout and presentation styles, protected parts but excludes the document profile. +- 3.63 document class:** A set of logical object class descriptions, layout object class descriptions, generic content portion descriptions, styles and a document profile, that specifies a set of documents with common characteristics. +- 3.64 document class description:** The specification of a document class. +- 3.65 document layout process:** The process that creates a specific layout structure in accordance with the generic layout structure and information contained in the specific logical structure, the generic logical structure and the layout styles. +- 3.66 document layout root:** The composite object of the specific layout structure at the highest level of the hierarchy. + +- 3.67 document logical root:** The composite object of the specific logical structure at the highest level of the hierarchy. +- 3.68 document profile:** A set of attributes which specifies the characteristics of the document as a whole. +- 3.69 editing:** The carrying out of operations associated with creation and modification of the structure and/or the content of a document. +- 3.70 editing process:** The stage of document processing that consists of the content editing process and the logical structure editing process. +- 3.71 end-aligned:** +- a) The result of a layout or imaging process that positions the sequence of character images for a line such that the escapement point of the last character image is positioned at the end edge of the positioning area. + - b) A tabulation alignment that positions the sequence of character images for a specified character string such that the escapement point of the last character image is positioned at the tabulation stop. +- 3.72 end edge:** The edge of the positioning area of a basic layout object that is in the direction of the character path. +- 3.73 escapement point:** A reference point associated with a character image that is used for positioning of the next character image. +- 3.74 external document class:** A document class referred to by the document profile of an interchanged document containing no generic structure. +- 3.75 factor set:** One or more object class descriptions which are used to factorise the attributes of object descriptions representing a specific structure. +- 3.76 file:** A named collection of information. +- 3.77 file section:** For a file recorded over more than one volume, that part of the file that is recorded on any one volume. +- NOTE – The term *file* in ISO 9293 is equivalent to the term *file section* in this Specification. +- 3.78 file space:** The region within which a file section may be recorded on a volume. +- 3.79 filing:** The storage of a document according to some defined method in order to facilitate retrieval of the document. +- 3.80 fingerprint:** A short and compact code that may be computed in order to characterize some specified information, with the property that it is not practicable to construct different information which would yield the same output. +- 3.81 font:** A set of character images normally with a common design and size. +- 3.82 font size:** The height of the character images in a font. +- 3.83 formatted form:** A form of representation of a document that allows the presentation of the document as intended by the originator and that does not support editing and (re)formatting. +- 3.84 formatted processable form:** A form of representation of the document that allows presentation of the document as intended by the originator and also supports editing and (re)formatting. +- 3.85 formatting:** The carrying out of operations to determine the layout of a document. +- 3.86 frame:** A type of composite layout component that corresponds to a rectangular area within a page or another frame. +- 3.87 generic content portion:** A content portion associated with an object class. +- 3.88 generic content portion description:** A content portion description associated with an object class description. +- 3.89 generic-document:** A structured amount of information intended for the interchange of generic structures, and optionally associated styles and content portions, for use in the processing of interchanged documents. +- 3.90 generic layout structure:** A set of layout object classes and associated generic content portions. +- 3.91 generic logical structure:** A set of logical object classes and associated generic content portions. + +- 3.92 geometric graphic element:** A graphic element used to describe an image by geometric graphical means. +NOTE – Geometric graphics elements include those describing primitive geometric shapes such as points, arcs, lines. +- 3.93 graphic character:** A member of a set of graphic symbols used for the representation of information. +NOTE – Graphic characters include simple alphanumeric characters (for example, accented letters) and pictorial characters (for example, mosaics). +- 3.94 graphic element:** A content element that is capable of having a visual representation. +NOTE – Three types of graphic elements are distinguished in the ITU-T Rec. T.410-Series | ISO/IEC 8613: graphic characters, raster graphics elements, and geometric graphics elements. +- 3.95 hard line terminator:** A line terminator that is intended not to be removed in a reformatting process. +- 3.96 horizontal direction (of a layout object):** The direction in a layout object relative to which content architectures may define attributes determined by using the horizontal axis of the page. +- 3.97 imaging order:** The order of precedence of layout objects for imaging in the layout object to which they are immediately subordinate. +- 3.98 imaging process:** The process of producing a document on a presentation medium in human-perceptible form, making use of the document profile, specific and generic layout structures, presentation styles and content portions. +- 3.99 implicit layout category:** The layout category of a logical object which is used in the absence of an explicit specification of a layout category for that object. +- 3.100 indentation:** The result of a layout or imaging process that causes the sequence of character images for a line to begin at a distance from the line home position in the direction of the character path. +- 3.101 initial point:** +- a) The point associated with a basic layout object relative to which all line boxes imaged within that basic layout object are positioned (character content architectures ITU-T Rec. T.416 | ISO/IEC 8613-6). + - b) The point associated with a basic layout object relative to which all pels imaged within that basic layout object are positioned (raster graphics content architectures ITU-T Rec. T.417 | ISO/IEC 8613-7). +- 3.102 integrity:** Used here synonymously with data integrity. +- 3.103 intended recipient:** A recipient of a document that is expected to receive or have access to the document. +- 3.104 interchange:** The process of providing a document to a receiving person or device, by means of data communication or by exchange of storage media. +- 3.105 interchange data element:** A data structure representing a constituent of a document. +- 3.106 interchange format:** The rules for representing a document for the purpose of interchange. +- 3.107 interchange format class:** A form of interchange format suitable to a specific application. +NOTE – In the ITU-T Rec. T.410-Series | ISO/IEC 8613, the defined classes differ by the ordering of the interchange data elements or by the coding. +- 3.108 interchangeable storage medium:** Storage medium which can be used to interchange information by moving the medium from one information processing system to another. +- 3.109 inter-character space:** An additional amount of spacing that is included between adjacent character images. +- 3.110 intersection:** The common area of two or more layout objects that overlap each other partially or fully on the presentation medium. +- 3.111 item identifier:** A string of characters that precedes and is separated from the remainder of the first line of a basic component with content. An item identifier is used to identify the subsequent text. +- 3.112 justified:** The result of a layout or imaging process that varies the width of the space character and/or the inter-character space to produce a simultaneously start-aligned and end-aligned presentation of the text. +- 3.113 kern:** The part of a character image which extends beyond its position point or escapement point. +- 3.114 layout category:** The association of basic logical objects with lowest level frames such that the content of these basic logical objects is placed in the appropriate frames. +- 3.115 layout object:** An element of the specific layout structure of a document, for example, page, block. + +**3.116 layout object class:** An element of the generic layout structure from which a set of layout objects with common characteristics may be derived, for example, pages with common headers and footers. + +**3.117 layout process:** The stage of document processing that consists of the document layout process and the content layout process. + +NOTE – This is also referred to as formatting. + +**3.118 layout stream:** A set of basic logical objects pertaining to the same layout category. + +**3.119 layout structure:** + +- a) The result of dividing and subdividing the content of a document into increasingly smaller parts, on the basis of the presentation, for example, into pages, blocks. +- b) All layout objects and associated content portions forming the layout hierarchy of a document. + +**3.120 layout style:** A constituent of the document, referred to from a logical component, that guides the creation of a specific layout structure. + +**3.121 leading edge:** The edge of a frame or block that is orthogonal to the direction of the layout path and that is met first, from the outside of the frame or the block, in the opposite direction of the layout path. + +**3.122 left hand edge:** The edge of a frame or block that is parallel to the direction of the layout path and that is met first, from the outside of the frame or the block, in the direction at an angle of 270 degrees counterclockwise relative to the direction of the layout path. + +**3.123 line box:** A rectangular area within which a sequence of character images are positioned. + +**3.124 line home position:** The point within a line box that is used for positioning that line box. + +**3.125 line progression:** + +- a) The direction of progression of successive line boxes within a basic layout object (character content architectures ITU-T Rec. T.416 | ISO/IEC 8613-6). +- b) The direction of progression of successive lines of pels within a basic layout object (raster graphics content architectures ITU-T Rec. T.417 | ISO/IEC 8613-7). + +**3.126 line spacing:** + +- a) The distance between two adjacent reference lines within a basic layout object (character content architectures ITU-T Rec. T.416 | ISO/IEC 8613-6). +- b) The distance between two adjacent lines of pels within a basic layout object (raster graphics content architectures ITU-T Rec. T.417 | ISO/IEC 8613-7). + +**3.127 line terminator:** A control function or combination of control functions that indicates the end of a line or the end of a character sequence. + +**3.128 logical object:** An element of the specific logical structure of a document which may have a meaning that is significant to the application or user, for example, chapter, section, paragraph. + +**3.129 logical object class:** An element of the generic logical structure from which a set of logical objects with common characteristics may be derived, for example, composite logical objects representing sections with a common internal structure. + +**3.130 logical structure:** + +- a) The result of dividing and subdividing the content of a document into increasingly smaller parts, on the basis of the human-perceptible meaning of the content, for example, into chapters, sections, paragraphs. +- b) All logical objects and associated content portions representing the logical hierarchy of a document. + +**3.131 logical structure editing process:** The process that creates a new specific logical structure or modifies a previous specific logical structure and allocates or (re)allocates content to basic logical objects. + +**3.132 mandatory attribute:** An attribute which, when applicable to a constituent, must be specified explicitly in the constituent. + +**3.133 nominal page:** A rectangular area which, as assumed by the sender of a document, has the ideal size of the presentation surface. + +NOTE – Examples of ideal sizes are given in ISO 216. + +**3.134 non-basic:** A qualifier for attribute values, control function parameter values and other capabilities that are allowed in document interchange in the context of a given document application profile only if their use is declared in the document profile. + +**3.135 non-mandatory attribute:** An attribute which, when applicable to a constituent, need not be specified explicitly; if the attribute is not specified explicitly in a given constituent, the attribute does not apply. + +**3.136 non-repudiation of origin:** The property that an originator can be proved to the satisfaction of a third party to be the source of a document or a specified part of it. + +**3.137 object:** An element of the specific layout structure or of the specific logical structure. + +**3.138 object class:** An element of a generic structure from which objects with common characteristics may be derived. + +**3.139 object class description:** A set of attributes that specify the properties of an object class including its relationships, if any, with other components. + +**3.140 object description:** A set of attributes that specify the properties of an object including its relationships, if any, with other components. + +**3.141 object type:** A property of every component that specifies which attributes are permitted in the description to which it applies and indicates the role of the component in the document architecture. + +**3.142 ODA data stream:** A data stream conforming to the ITU-T Rec. T.410-Series | ISO/IEC 8613 in which the data elements representing constituents and attribute values are in accordance with ITU-T Rec. T.412, T.414 ISO/IEC 8613-2, 8613-4 and one or more of the ITU-T Rec. T.410-Series | ISO/IEC 8613 Specifications including: + +- ITU-T Rec. T.416 | ISO/IEC 8613-6; +- ITU-T Rec. T.417 | ISO/IEC 8613-7; +- ITU-T Rec. T.418 | ISO/IEC 8613-8; + +and any referenced standards. + +**3.143 Open Document Language; ODL (abbreviation):** A Standard Generalized Markup Language (SGML, ISO 8879) application for representing documents conforming to ISO/IEC 8613. + +**3.144 orphan:** One or more lines of text that are associated with subsequent text but isolated from it by a page or column boundary. + +**3.145 overhang:** The result of a layout or imaging process that positions the sequence of character images for a line to begin at a distance from the line home position in the direction opposite to the character path. + +**3.146 page:** A layout component that corresponds to a rectangular area used for presenting the content of the document. + +**3.147 page coordinate system:** An orthogonal coordinate system whose origin is the top left corner of the page; its horizontal axis and its vertical axis coincide with the top edge and the left edge of the page, respectively. + +**3.148 page set:** A composite layout component that represents a collection of pages or further page sets. + +**3.149 pairwise kerning:** The distance between two adjacent character images depending on the combination of the two characters together rather than separately. + +**3.150 parallel annotation:** Two sequential character strings that are presented in parallel, wherein the second string is used to indicate the pronunciation or interpretation of the first string. + +**3.151 partial generator set:** A collection consisting of hierarchically related object class descriptions which are used to guide the creation of hierarchically related corresponding object descriptions but do not fully specify all specific structures that may be created. + +**3.152 pel array:** A two-dimensional array of pels used to represent a pictorial image. + +**3.153 pel path:** The direction of progression of successive pels along a line within a basic layout object. + +**3.154 pel spacing:** The distance between any two successive pels along a line within a basic layout object. + +**3.155 picture element; pel (abbreviation):** The smallest graphic element that may be individually addressed within a picture (an alternative term for raster graphics element). + +- 3.156 positioning area:** The rectangular area within a basic layout object within which the position points and the escapement points of all character images are located. +- 3.157 position point:** The point relative to which the character image is placed, i.e. the character is imaged with the position point at the active position. +- 3.158 presentation:** The operation of rendering the content of a document in a form perceptible to a human being. +- 3.159 presentation medium:** The carrier of information in a form perceptible to a human being. +- 3.160 presentation style:** A constituent of the document, referred to from a basic logical or layout component, which guides the format and appearance of the document content. +- 3.161 presentation surface:** A two-dimensional presentation medium (such as paper, film, video display screen) on which the formatted form of a document may be displayed for human viewing. +- 3.162 primary description:** A description that represents a basic object that best represents the intent of the originator. +- 3.163 primary subtree:** The basic object description in conjunction with its associated content portion descriptions, with the potential to be replaced by an alternative subtree. +- 3.164 privileged recipient:** A recipient of a document that in addition to being an intended recipient, has the right to perform certain security-related operations intended for that particular recipient, such as to interpret specified enciphered parts of the document, and to perform integrity and authenticity checks on specified parts of the document. +- 3.165 processable form:** A form of representation of a document that allows editing and formatting. +- 3.166 processing:** The carrying out of operations on a document, including editing, (re)formatting, presentation, filing and retrieval. +- 3.167 protected part:** A constituent consisting of a part of the document that is sealed or enciphered, e.g. a sealed document profile or pre-enciphered document body part. +- 3.168 raster graphics element:** An alternative term for a picture element (pel). +- 3.169 recipient:** Any application or user receiving or having access to a document. +- 3.170 record:** A sequence of bytes treated as a unit of information stored on a file. + +standard for volume and file structure: An international standard that specifies the format of the recorded structures that contain descriptive information about the volume and the files recorded on an interchangeable storage medium. + +- 3.171 reference area:** A rectangular area within a basic layout object, with its sides equal to the pel spacing and the line spacing, within which the main part of a pel is imaged. +- 3.172 reference colour space:** Basic colour space within ODA relative to which relationships to colour spaces used in document and content architectures are specified. +- NOTE – The reference colour space is defined by the Commission Internationale de l'Eclairage (CIE) Standard Colorimetric System (XYZ), 1931. +- 3.173 reference line:** A line through the line home position and parallel to the character path. +- 3.174 reference point:** The point at the corner of the reference area situated in the opposite direction of both pel path and line progression and which is used for positioning a pel. +- 3.175 reformatting:** The carrying out of operations to determine the new layout of a previously formatted document. +- 3.176 region of interest:** A rectangular area within a virtual coordinate space, with sides which are parallel to the axes of its coordinate system, surrounding those (parts of) geometric graphics that are intended to be imaged. +- 3.177 resource-document:** A generic-document containing one or more object class descriptions and their associated generic content descriptions referred to by one or more object class descriptions of another document. +- 3.178 retrieval:** The recovery of previously filed information. +- 3.179 Red Green Blue; RGB (abbreviation) colour space:** A colour space based on red, green and blue stimuli or primaries. + +# NOTES + +- 1 The RGB values are not to be confused with the CIE **Error!** as defined in CIE colorimetry. +- 2 RGB values are negative in certain areas outside the gamut defined by the RGB primaries. + +- 3.180 right hand edge:** The edge of a frame or block that is parallel to the direction of the layout path and that is met first, from the outside of the frame or the block, in the direction at an angle of 90 degrees counterclockwise relative to the direction of the layout path. +- 3.181 scaled measurement unit; SMU (abbreviation):** A unit of linear measurement used for positioning and dimensioning layout objects and content elements on a presentation surface, its value being equal to the basic measurement unit (BMU) times the unit scaling. +- 3.182 seal (noun):** Data associated with a specified part of a document by an originator, which a recipient (privileged recipient) may use to verify the integrity and authenticity of the specified part. +- 3.183 seal (verb):** To associate a seal with a specified part of a document. +- 3.184 security domain:** The set of resources subject to a single security policy. +- 3.185 security label:** A marking of a document, which specifies the handling of the document according to the security policy in force. +- 3.186 security policy:** The set of rules that specify the procedures and services required to maintain the intended level of security of a set of resources. +- 3.187 sequential layout order:** The sequential order in which layout objects are to be imaged when an imaging order is not specified. +- 3.188 sequential logical order:** The sequential order in which logical objects are to be processed by the layout process. +- 3.189 sequential order:** A convention for ordering the objects in a structure such that each object is succeeded by all of its immediate subordinates, before any other object with the same immediate superior, i.e. in order tree traversal. +- 3.190 soft line terminator:** A line terminator that is allowed to be removed, relocated or replaced in a subsequent layout process. +- 3.191 spacing ratio:** The ratio of line spacing to pel spacing. +- 3.192 specific layout structure:** A set of layout objects and associated content portions. +- 3.193 specific logical structure:** A set of logical objects and associated content portions. +- 3.194 start-aligned:** +- a) The result of a layout or imaging process that positions the sequence of character images for a line such that the position point of the first character image of that sequence is positioned on the line home position or at the point specified by the first line indentation or overhang, if any, for the line. + - b) A tabulation alignment that positions the sequence of character images for a specified character string such that the position point of the first character image of that sequence is positioned at the tabulation stop. +- 3.195 start edge:** The edge of the positioning area of a basic layout object that is in the direction opposite to the character path. +- 3.196 stream root category:** A property of components that can be used to designate the layout objects into which the content associated with logical objects shall be placed. +- 3.197 stream root sub category:** A property of components that can be used to designate the subordinate layout objects into which the content associated with logical objects shall be placed. The designated subordinate layout objects shall all be subordinates of a single layout object that has the property of being a stream root category layout object. +- 3.198 structural element:** The structural elements of a document are the content portion, the object and the object class. +- 3.199 tabulation alignment:** A layout or imaging process that causes the sequence of character images for a specified character string to be positioned according to a specified method, (start-aligned, end-aligned, centred or aligned-around) at a specified point (tabulation stop) along a reference line. +- 3.200 tabulation stop:** A position along a reference line that is to be used for a specified method (start-aligned, end-aligned, centred or aligned-around) of tabulation alignment. +- 3.201 tile:** One element of a two dimensional array of non-overlapping rectangular regions of a pel array. +- 3.202 text unit:** A data structure representing a content portion description. + +- 3.203 top edge:** The edge of the positioning area of a basic layout object that is in the direction opposite to the line progression. +- 3.204 top left corner:** The corner of a layout object that is least progressed both in the horizontal and vertical directions of this layout object. +- 3.205 top right corner:** The corner of a layout object that is most progressed in the horizontal direction and least progressed in the vertical direction of this layout object. +- 3.206 trailing edge:** The edge of a frame or block that is orthogonal to the direction of the layout path and that is met first, from the outside of the frame or the block, in the direction of the layout path. +- 3.207 unit scaling:** A scaling factor (an integer or a fraction) that is applied to the basic measurement unit (BMU) to derive a scaled measurement unit (SMU). +- 3.208 variable spacing:** The characteristics of a font wherein the distance between the position point and the escapement point for different character images may be different. +- 3.209 volume:** A dismountable physical unit of storage medium, for example a flexible disk cartridge. +- 3.210 widow:** One or more lines of text associated with preceding text but isolated from it by a page or column boundary. + +# 4 Abbreviations + +For the purposes of this Recommendation | International Standard, the following definitions apply. + +| | | +|--------|---------------------------------------------------------------------------------------------------| +| ASN.1 | Abstract Syntax Notation One | +| BMU | Basic Measurement Unit | +| BNF | Backus-Naur-Form | +| CF | Character Formatted | +| CGM | Computer Graphics Metafile | +| CIE | Commission Internationale de l'Eclairage | +| CIELAB | Commission Internationale de l'Eclairage lightness-hue-chroma CIE 1976 $L^* a^* b^*$ colour space | +| CIELUV | Commission Internationale de l'Eclairage lightness-hue-chroma CIE 1976 $L^* u^* v^*$ colour space | +| CMY | Cyan Magenta Yellow | +| CMY(K) | Cyan Magenta Yellow Black | +| DAPPN | Document Application Profile Proforma Notation | +| DIS | Disallowed | +| ECMA | European Computer Manufacturer's Association | +| FDA | Formatted Document Architecture | +| FODA | Formal Specification of the Open Document Architecture | +| FPDA | Formatted Processable Document Architecture | +| ID | Identifier | +| IMCL | Information Modeling by Composition Language | +| IPM | Interpersonal Message | +| IPMS | Interpersonal Message System | +| LUT | Colour LookUp Table | +| MHS | Message Handling System | +| mm | Millimeter | +| MOTIS | Message Oriented Text Interchange System | +| MTS | Message Transfer System | +| MUL | Multiple (Repetition) | +| NIST | National Institute of Standards and Technology | +| NOVR | No Override | + +| | | +|-------|----------------------------------------------------| +| ODA | Open Document Architecture | +| ODIF | Open Document Interchange Format | +| ODL | Open Document Language | +| PDA | Processable Document Architecture | +| pel | Picture Element | +| PERM | Permitted | +| PMUL | Permitted Multiple (Optional Repetition) | +| RGB | Red Green Blue | +| REQ | Required | +| SDIF | SGML Document Interchange Format | +| SGML | Standard Generalized Markup Language | +| SMPTE | Society of Motion Picture and Television Engineers | +| SMU | Scaled Measurement Unit | +| tpi | Tracks Per Inch | +| tpmm | Tracks Per Millimeter | + +# 5 Conventions + +The following conventions are used within this Recommendation | International Standard. In this clause, the word parameter(s) is to be interpreted to apply to parameter(s), sub-parameter(s), sub-sub-parameter(s), etc. to any level. + +## 5.1 Names of attributes and parameters + +The names of attributes and parameters are referenced by giving the name of the attribute or parameter in double quotation marks preceded by the word attribute or parameter. For example: + +- ...expressed by the attribute “subordinates”. This attribute...; +- ...two parameters “horizontal dimension”...; +- ...by a sub-parameter “fixed dimension”.... + +In some cases terms are used to describe concepts which have the same name as an attribute or parameter. In the case of reference to such concepts neither the word attribute or parameter nor quotes are used. + +## 5.2 Names of attribute and parameter values + +If the values of attributes and parameters are terminal symbols, they are referenced by giving the name of the attribute or parameter value in single quotation marks. For example: + +- ...value is ‘opaque’; +- ...this parameter allows a sender to select a recto or a verso presentation of the page by specifying the value ‘recto’ or ‘verso’, respectively. + +## 5.3 Component and component description + +The term component may be used in conjunction with qualifying terms, including: basic, composite, page set, page, frame, block, logical and layout. For example: + +- a) layout components containing blocks means layout objects containing blocks, or layout object classes containing blocks; +- b) frame component means an object of type frame, or a class to which objects of type frame belong. + +The term component description may be qualified in the same way. + +## 5.4 Introduction of terms + +Italics are used for the purpose of highlighting the point at which the definition of a term occurs in the text. + +These terms are also defined in clause 3. + +## 5.5 Representation of degrees + +A lower case d is used for the purpose of signifying that the associated value specifies degrees. For example, the notation d0 specifies zero degrees and d180 specifies 180 degrees. + +# 6 General concept of ODA + +## 6.1 Purpose of ODA + +The purpose of the document architecture is to facilitate the interchange of documents in a manner such that: + +- different types of content, including text, image, graphic and audio, can coexist within a document; +- the intentions of a document originator with respect to the logical and layout structure of a document can be transmitted to a recipient. + +It also supports security aspects such as + +- protection against unauthorized semantic knowledge of parts of a document; +- detection of discrepancies between the claimed and actual source and content of parts of the document. + +This clause uses a number of terms for which definitions are given in clause 3. However, for the purpose of the current clause, different though compatible definitions of the essential terms are given below. + +- *Interchange* – The process of providing a document to a receiving person or device, by means of data communication or by exchange of storage media. +- *Editing* – The carrying out of operations associated with creation and modification of the structure and/or the content of a document. +- *Formatting* – The carrying out of operations to determine the layout of a document, i.e. the appearance of its content on a presentation medium. +- *Presentation* – The operation of rendering the content of a document in a form perceptible to a human being. Typical presentation media are paper, and video screens. + +The document architecture provides for the representation of documents in three forms: + +- formatted form, that allows documents to be presented as intended by the originator; +- processable form, that allows documents to be edited and formatted; +- formatted processable form, that allows documents to be presented as well as edited and reformatted. + +Alternative terms commonly used are final form and image form for formatted form, and revisable form for processable form. + +Each of these forms allows the originator to express intentions regarding the structuring and/or formatting of the interchanged document. + +## 6.2 Overall concept of ODA + +The concept of ODA is based on + +- the existence of a layout view and a logical view of the document; the view from the physical viewpoint (for example, a collection of pages) and the view in the sense of its abstract components (for example, an assembly of chapters); +- the existence of a specific structure and a generic structure; the specific document structure is the one that the user may read; the generic structure is the template that guides the creation of the document and that could be re-used for its amendment; +- the existence of document classes; a document class is the set of generic features that are common to a category of documents (for example, Sales Report Form). + +### 6.2.1 Logical structure and layout structure + +The key concept in the document architecture is that of structure. Document structure is the division and repeated subdivision of the content of a document into increasingly smaller parts. The parts are called objects. The structure has the form of a tree. + +The document architecture permits two structures to be applied to a document: a logical structure and a layout structure. Any one or both structures may be applied to a given document. + +In the logical structure, the document is divided and subdivided on the basis of the meaning. Examples of logical objects are chapters, sections, figures and paragraphs. + +In the layout structure, the document is divided and subdivided on the basis of the layout. Examples of layout objects are pages and blocks. + +An example of the logical view of a document called report is shown in Figure 1. + +![Figure 1: Example of a logical view of a document. The diagram shows a hierarchical tree structure for a 'Report'. The root is 'Report', which branches into 'Report heading', 'Table of contents', and 'Chapter'. 'Report heading' branches into 'Author's name', 'Title', and 'Date'. 'Table of contents' branches into 'T.O.C. entry', which further branches into 'Chapter number', 'Chapter title', and 'Page reference'. 'Chapter' branches into 'Chapter heading' and 'Section'. 'Section' branches into 'Section heading' and 'Section element'. 'Section element' branches into 'Paragraph' and 'Figure'. 'Figure' branches into 'Picture' and 'Caption'. A legend on the left explains the notation: a double-lined box represents 'One or more occurrence of A'; a box 'A' with lines to boxes 'B' and 'C' represents 'A consists of B and C'; and a box 'A' with lines to either 'B' or 'C' represents 'A consists of B or C'. The identifier 'T0812470-93/d01' is at the bottom right.](d9c0a780cd22626253dab4aa41699e2f_img.jpg) + +``` + +graph TD + Report[Report] --> Report_heading[Report heading] + Report --> Table_of_contents[Table of contents] + Report --> Chapter[Chapter] + + Report_heading --> Author_name[Author's name] + Report_heading --> Title[Title] + Report_heading --> Date[Date] + + Table_of_contents --> TOC_entry[T.O.C. entry] + TOC_entry --> Chapter_number[Chapter number] + TOC_entry --> Chapter_title[Chapter title] + TOC_entry --> Page_reference[Page reference] + + Chapter --> Chapter_heading[Chapter heading] + Chapter --> Section[Section] + + Section --> Section_heading[Section heading] + Section --> Section_element[Section element] + + Section_element --> Paragraph[Paragraph] + Section_element --> Figure[Figure] + + Figure --> Picture[Picture] + Figure --> Caption[Caption] + +``` + +Legend + +- A One or more occurrence of A +- A A consists of B and C +- A A consists of B or C + +T0812470-93/d01 + +Figure 1: Example of a logical view of a document. The diagram shows a hierarchical tree structure for a 'Report'. The root is 'Report', which branches into 'Report heading', 'Table of contents', and 'Chapter'. 'Report heading' branches into 'Author's name', 'Title', and 'Date'. 'Table of contents' branches into 'T.O.C. entry', which further branches into 'Chapter number', 'Chapter title', and 'Page reference'. 'Chapter' branches into 'Chapter heading' and 'Section'. 'Section' branches into 'Section heading' and 'Section element'. 'Section element' branches into 'Paragraph' and 'Figure'. 'Figure' branches into 'Picture' and 'Caption'. A legend on the left explains the notation: a double-lined box represents 'One or more occurrence of A'; a box 'A' with lines to boxes 'B' and 'C' represents 'A consists of B and C'; and a box 'A' with lines to either 'B' or 'C' represents 'A consists of B or C'. The identifier 'T0812470-93/d01' is at the bottom right. + +**Figure 1 – Example of a logical view of a document** + +The logical structure and the layout structure provide alternative but complementary views of the same document. For example, a book can be regarded as consisting of chapters containing figures and paragraphs, or alternatively, as consisting of pages that contain text blocks and/or graphic blocks. + +An object that is not subdivided into smaller objects is called a basic object. All other objects are called composite objects. + +The following types of layout objects are defined in the document architecture: + +- *block* – A basic layout object corresponding to a rectangular area on the presentation medium containing a portion of the document content. +- *frame* – A composite layout object corresponding to a rectangular area on the presentation medium and containing either one or more frames or one or more blocks. +- *page* – A basic or composite layout object corresponding to a rectangular area on the presentation medium and, if it is a composite object, containing either one or more frames or one or more blocks or, if it is a basic object, containing one or more content portions of the document content. +- *page set* – A set of one or more page sets and/or pages. +- *document layout root* – The highest level object in the hierarchy of the specific layout structure. + +For logical objects, no classification other than basic logical object, composite logical object and document logical root is defined in the document architecture. Logical object categories such as chapter, section and paragraph are application-dependent and can be defined by a document application profile using the object class mechanism (see 6.2.6). + +### 6.2.2 Content portions + +The basic elements of the content of a document are called content elements. For content consisting of character text, the content elements are characters. In the case of images or graphics, the content elements are picture elements (also called pels) or geometric graphics elements (lines, arcs, polygons, etc.). + +When a document has both logical structure and layout structure, each content element belongs, in general, to exactly one basic logical object and to exactly one basic layout object. A set of related content elements that belong to one basic logical object (if the document has any logical structure) and one basic layout object (if the document has any layout structure) is collected within a constituent type called a content portion. + +The relationships between basic logical objects, basic layout objects and content portions are: + +- a basic logical object has associated with it one or more content portions; +- a basic layout object has associated with it one or more content portions; +- any logical or layout object (basic or composite) has associated with it zero or more content portions; +- there is, in general, no one-to-one correspondence between logical objects and layout objects. + +The last point is illustrated by Figure 2. + +![Figure 2: Possible correspondence between logical and layout objects. The diagram shows a hierarchical structure. At the top, a 'Section' box is connected by a dashed line to a horizontal line. Below this line, four boxes are shown: 'Section heading', 'Paragraph', 'Paragraph', and 'Paragraph'. Arrows point from the 'Section heading' box to a 'Content portion' box. Arrows point from each of the three 'Paragraph' boxes to their respective 'Content portion' boxes. Below the 'Content portion' boxes, there are three 'Block' boxes. Arrows point from the 'Content portion' box under 'Section heading' to the first 'Block' box. Arrows point from the 'Content portion' box under the first 'Paragraph' to the first 'Block' box. Arrows point from the 'Content portion' box under the second 'Paragraph' to the second 'Block' box. Arrows point from the 'Content portion' box under the third 'Paragraph' to the third 'Block' box. At the bottom, there are two 'Page' boxes. Arrows point from the first 'Page' box to the first 'Block' box. Arrows point from the second 'Page' box to the third 'Block' box. Dashed lines extend from the top of the 'Section' box and the bottom of the 'Page' boxes.](19a5f0db57a21a0e82a7f326083e96fd_img.jpg) + +Figure 2: Possible correspondence between logical and layout objects. The diagram shows a hierarchical structure. At the top, a 'Section' box is connected by a dashed line to a horizontal line. Below this line, four boxes are shown: 'Section heading', 'Paragraph', 'Paragraph', and 'Paragraph'. Arrows point from the 'Section heading' box to a 'Content portion' box. Arrows point from each of the three 'Paragraph' boxes to their respective 'Content portion' boxes. Below the 'Content portion' boxes, there are three 'Block' boxes. Arrows point from the 'Content portion' box under 'Section heading' to the first 'Block' box. Arrows point from the 'Content portion' box under the first 'Paragraph' to the first 'Block' box. Arrows point from the 'Content portion' box under the second 'Paragraph' to the second 'Block' box. Arrows point from the 'Content portion' box under the third 'Paragraph' to the third 'Block' box. At the bottom, there are two 'Page' boxes. Arrows point from the first 'Page' box to the first 'Block' box. Arrows point from the second 'Page' box to the third 'Block' box. Dashed lines extend from the top of the 'Section' box and the bottom of the 'Page' boxes. + +T0812480-93/d02 + +Figure 2 – Possible correspondence between logical and layout objects + +### 6.2.3 Content architectures + +A content portion associated with a basic logical object or a basic layout object may have a more detailed internal structure. The rules governing such an internal structure depend on the type of content and are called a content architecture. The content of a basic logical object or a basic layout object is structured according to only one content architecture. + +Definitions of content architectures are given in other Specifications of the ITU-T Rec. T.410-Series | ISO/IEC 8613. These include: + +- ITU-T Rec. T.416 | ISO/IEC 8613-6: Character content architectures; +- ITU-T Rec. T.417 | ISO/IEC 8613-7: Raster graphics content architectures; +- ITU-T Rec. T.418 | ISO/IEC 8613-8: Geometric graphics content architectures. + +### 6.2.4 Attributes + +An attribute is a property of a document, or of a document constituent (i.e. a logical object, a layout object, a logical object class, a layout object class, a style, a content portion or a protected part). It expresses a characteristic of the document or document component concerned, or a relationship with one or more documents or document components. + +The set of attributes associated with a document as a whole is called a document profile. It represents reference information about the document and may repeat information in the document content, for example, the title and the name of the author. + +The set of attributes that applies to a logical object or a layout object depends on the type of the object; different sets of attributes are defined for basic logical objects, composite logical objects, document logical root, blocks, frames, pages, page sets and document layout root. These are called document architecture attributes. In general, document architecture attributes are independent of the type of content of the objects to which they apply. + +Examples of document architecture attributes are: + +- the attribute “object identifier” (all objects); +- the attribute “subordinates” (composite objects); +- layout directives such as the attribute “concatenation”, the attribute “offset”, the attribute “separation” (basic logical objects); +- the attribute “position” (blocks and frames); +- the attribute “dimensions” (blocks, frames and pages). + +In addition to the document architecture attributes, a set of presentation attributes applies to basic logical and basic layout objects. The set of presentation attributes that applies to a given basic object depends on the content architecture governing the content of this object; a different set of presentation attributes is defined for each content architecture. + +Examples of presentation attributes are: + +- the attribute “character spacing” (character content architectures); +- the attribute “clipping” (raster graphics content architectures); +- the attribute “line rendition” (geometric graphics content architectures). + +Presentation attributes may be collected into presentation styles, to which references may be made from both logical and layout objects. The attributes that apply to a content portion include a content portion identifier and a set of coding attributes, the composition of which depends on the coding method used for the content, for example, the attribute “number of pels per line” for facsimile-coded raster graphics images. + +### 6.2.5 Relations between logical structure and layout structure + +The logical structure and the layout structure are, in principle, independent of each other. The logical structure of a document is determined by the author and embedded in the document during the editing process. The layout structure is usually determined by a formatting process. In addition to the presentation attributes, the formatting process may be controlled by attributes called layout directives associated with the logical structure. + +Examples of layout directives are: + +- the requirement that a chapter starts on a new page; +- the requirement that the title of a section and the first two lines of its first paragraph are presented on the same page. + +Layout directives may be collected into layout styles each of which may be referred to by one or more logical objects. + +### 6.2.6 Specific and generic structures + +In a document, the logical objects and/or the layout objects can often be classified into groups of similar objects. Therefore the concept of object class is introduced. + +The similarity can be related to logical features such as chapter, section or paragraph hierarchy, to layout features such as size or style, or to content such as page headers and footers. Even an entire document may be a member of a group of similar documents, a letter, a memorandum or a report. + +An object class or a document class is a specification of the set of properties that are common to its members. Such a specification consists of a set of rules to determine the values of the attributes that specify the common properties. These rules are used to control the consistency among the objects or documents making up the class, and to facilitate the creation of additional objects or documents within the class. + +The set of logical object classes and layout object classes associated with a document, and their relationships, are called generic logical structure and generic layout structure. + +The structures that are particular to a given document are named specific logical structure and specific layout structure. + +A document class contains a generic logical structure and/or a generic layout structure. In addition, all document class descriptions shall include a document profile and may include layout styles, presentation styles and generic content portion descriptions. + +The generic logical structure represents the set of all potential specific logical structures, and the generic layout structure represents the set of all potential specific layout structures that are applicable to the document class concerned. + +The generic logical structure is used as a set of rules from which specific logical objects and structures are derived during the editing process. The generic layout structure is used as a set of rules from which specific layout objects and structures are derived during the formatting process. + +An example of generic layout structure is depicted in Figure 3 which shows a page layout with frames for a header, a footer and two columns of body text. + +![Diagram of a page layout structure showing a header, two columns of body text, and a footer.](bb3354f497635d15bef873577125c48d_img.jpg) + +The diagram illustrates a generic layout structure for a page. It consists of a large outer rectangle with a dashed border. Inside this rectangle, there are three main sections: a top section labeled 'Header', a middle section labeled 'Body', and a bottom section labeled 'Footer'. The 'Body' section is further divided into two columns, each labeled 'Body' and containing the word 'Text'. All sections are enclosed in dashed lines, indicating they are frames or containers for content. + +Diagram of a page layout structure showing a header, two columns of body text, and a footer. + +T0812490-93/d03 + +**Figure 3 – Example of a page layout** + +### 6.2.7 Document profile + +The document profile consists of a set of attributes associated with a document as a whole. In addition to reference information such as title, date and author's name, which facilitates storage and retrieval of the document, the document profile contains a summary of the document architecture features some of which are and the remainder of which may be used in the document, in order that a recipient can easily determine which capabilities are required for processing or imaging the document. The attributes representing the latter type of information are called document characteristics and include: + +- a specification of the form (formatted, processable or formatted processable) of the document; +- specifications of the content architectures used in the document; +- specifications of the character sets, character fonts, character styles, character orientations and types of emphasis used in the document. + +The document profile may be interchanged alone. + +### 6.2.8 Generic-document + +A generic-document consisting of a document profile and generic structures may be used to assist in the processing of interchanged documents. A generic-document may be interchanged. + +### 6.2.9 Protected parts + +Protected parts enable protection to be provided for parts of a document offering confidentiality, integrity, authenticity and non-repudiation of origin. + +Protected parts cannot provide for the protection of a document as a whole. Treatment of the complete document as an object is outside the scope of this series of Recommendations | International Standards. + +Parts of a document may be protected before the layout process in their processable form, or after the layout process in formatted or formatted processable forms. + +## 6.3 Document processing model + +### 6.3.1 Relationships of ODA to document processing + +The ITU-T Rec. T.410-Series | ISO/IEC 8613 is concerned with the definition of a document architecture which permits processing of interchanged documents. A model of document processing is provided as a basis for determining the scope of the processes described by the ITU-T Rec. T.410-Series | ISO/IEC 8613. + +A basic model of document processing is summarized in this subclause (see Figure 4). This model is not intended to represent an actual implementation, nor to restrict in any way the processing that may be applied to an interchanged document. + +Conceptually, a document is viewed as progressing through three phases of processing as shown in Figure 4. The order of the processes is not intended to imply that they are performed sequentially in an actual implementation. + +### 6.3.2 Editing process + +The document editing process is concerned with creating a new document or modifying an existing one. The document architecture provides data structures for representing the document resulting from this process. + +While document creation and modification can differ in the functions performed and procedures followed, they are considered to be equivalent in the view of this model because the result of both is the same: a new document. + +Upon completion of editing, the resulting document may be interchanged. Such a document is said to be interchanged in processable form; it is suitable for input to either the editing or layout process. + +### 6.3.3 Layout process + +The document layout process is concerned with defining a page-oriented organization (i.e. a layout) for the document content. This process can operate in two ways. + +The layout process can generate a document which is not intended to be modified; it is suitable only for input to the imaging process. Such a document is said to be in formatted form. + +This process can also generate a formatted processable form document which can be processed further if desired; it is suitable for input to any of the imaging, layout or editing processes. + +A formatted processable form document which is processed by an editing process is considered to have reverted to its processable form, because editing changes in the processable form usually result in concomitant changes to the formatted form. The extent to which the original formatted form of the edited document is preserved is regarded as a locally defined agreement between the editing and layout processes and is not defined by the ITU-T Rec. T.410-Series | ISO/IEC 8613. + +The document architecture provides data structures for representing both forms of formatted documents and for representing control information which influences the layout process. + +### 6.3.4 Imaging process + +The document imaging process is concerned with presenting an image of the document in a form perceptible to a human, for example, on paper or on a screen. A document interchanged in accordance with the ITU-T Rec. T.410-Series | ISO/IEC 8613 may contain information relating to the imaging process which allows it to be imaged as required by the originator of the document. However, the imaging process is not defined by the ITU-T Rec. T.410-Series | ISO/IEC 8613 and is regarded as a locally defined process that depends on the presentation device used. + +Other forms of document processing are possible; these are not specifically addressed by the document architecture. + +![Figure 4 – Basic document processing model. A flowchart showing the relationships between document forms and processes. 'Processable document' (interchangeable data structure) flows to 'Editing process' (process). 'Editing process' flows to 'Formatted processable document' (interchangeable data structure). 'Formatted processable document' flows to 'Layout process' (process). 'Layout process' flows to 'Formatted document' (interchangeable data structure). Both 'Formatted processable document' and 'Formatted document' flow to 'Imaging process' (process). 'Imaging process' flows to 'Document' (image). A legend indicates: dashed box = Interchangeable data structure, solid box = Process, dotted box = Image. Reference: T0812500-93/d04.](705ee99c3c44fd2a1ea6a3348ce8878f_img.jpg) + +``` + +graph TD + PD[Processable document] --> EP[Editing process] + EP --> FPD[Formatted processable document] + FPD --> LP[Layout process] + LP --> FD[Formatted document] + FPD --> IP[Imaging process] + FD --> IP + IP --> Doc[Document] + +``` + +Legend: + +- Interchangeable data structure (dashed box) +- Process (solid box) +- Image (dotted box) + +T0812500-93/d04 + +Figure 4 – Basic document processing model. A flowchart showing the relationships between document forms and processes. 'Processable document' (interchangeable data structure) flows to 'Editing process' (process). 'Editing process' flows to 'Formatted processable document' (interchangeable data structure). 'Formatted processable document' flows to 'Layout process' (process). 'Layout process' flows to 'Formatted document' (interchangeable data structure). Both 'Formatted processable document' and 'Formatted document' flow to 'Imaging process' (process). 'Imaging process' flows to 'Document' (image). A legend indicates: dashed box = Interchangeable data structure, solid box = Process, dotted box = Image. Reference: T0812500-93/d04. + +Figure 4 – Basic document processing model + +# 7 Overview of the ITU-T Rec. T.410-Series | ISO/IEC 8613 + +The Specifications of the ITU-T Rec. T.410-Series are numbered T.411, T.412 and T.414 through T.418. At present there is no T.413. The Parts of ISO/IEC 8613 are numbered 8613-1, 8613-2, 8613-4 through 8613-8 and 8613-10. At present, there is no 8613-3 or 8613-9. + +## 7.1 ITU-T Rec. T.411 | ISO/IEC 8613-1: Introduction and general principles + +This Specification provides information about the ITU-T Rec. T.410-Series | ISO/IEC 8613 as a whole by way of an introductory description of the document architecture, an overview of each of the Specifications and a description of their inter-dependencies. References necessary for all Specifications are given, and terms used throughout all Specifications are defined. Conformance to the ITU-T Rec. T.410-Series | ISO/IEC 8613 is specified and rules for defining document application profiles are given. + +## 7.2 ITU-T Rec. T.412 | ISO/IEC 8613-2: Document structures + +ITU-T Rec. T.412 | ISO/IEC 8613-2 defines document architecture concepts which may be applied to the description of representations of documents. The purpose is to permit a common understanding of the structure of a document. The term *document architecture* is used to mean a set of rules by which a document may be produced or interpreted. + +ITU-T Rec. T.412 | ISO/IEC 8613-2 describes the architectural concepts and defines the document structures and attributes. It specifies the interface between the document architecture and the content architectures, and defines the document architecture classes. A description of the document processing model is provided. In addition, examples of document structures based on the ITU-T Rec. T.410-Series | ISO/IEC 8613 and a suggested notation for representing them are included. + +## 7.3 ITU-T Rec. T.414 | ISO/IEC 8613-4: Document profile + +ITU-T Rec. T.414 | ISO/IEC 8613-4 defines the document profile that provides information concerning the handling of the document. This is accomplished by means of attributes (for example, title, authors), a few of which apply to the representation of the document profile itself. Some relate to the processing of the document (for example, filing/retrieval, other applications). Other attributes provide a means for a user to specify user-specific information (for example, organization, status). Some of the information given in the document profile could duplicate that in the body of the document. + +The document profile may be interchanged alone, that is without the remainder of the document constituents. + +NOTE – Information contained in the document profile is intended for a recipient (person) and/or device (for example, keywords). Some attribute values can have been automatically generated by a process (for example, size). + +## 7.4 ITU-T Rec. T.415 | ISO/IEC 8613-5: Open document interchange format + +ITU-T Rec. T.415 | ISO/IEC 8613-5 defines the format of the data stream used to interchange office documents structured in accordance with ITU-T Rec. T.412 | ISO/IEC 8613-2. + +The ODIF data stream is described in terms of a set of data structures, called interchange data elements, which represent the constituents (document profile, object descriptions, object class descriptions, presentation styles, layout styles, content portion descriptions and protected parts) of a document. The formats of the interchanged data elements according to ODIF are defined using the Abstract Syntax Notation One (ASN.1) specified in CCITT Rec. X.208 | ISO/IEC 8824. + +ISO/IEC 8613-5 also specifies a clear text language, known as the Open Document Language (ODL), that is used to represent and process documents structured in accordance with ISO/IEC 8613-2. The use of ODL is applicable to ISO/IEC 8613 only. + +ODL uses the Standard Generalized Markup Language (SGML) specified in ISO 8879. It consists of a standard set of SGML names and markup conventions for representing the constituents and attributes of a document. + +The SGML Document Interchange Format (SDIF) specified in ISO 9069 may be used for interchange of ODA documents represented in ODL between conforming SGML systems. + +Both data structure (ODIF) and language (ODL) representations have been standardized in order to meet the document representation requirements of distinct application environments. + +## 7.5 ITU-T Rec. T.416 | ISO/IEC 8613-6: Character content architectures + +ITU-T Rec. T.416 | ISO/IEC 8613-6 applies to documents that are structured according to the architecture defined in ITU-T Rec. T.412 | ISO/IEC 8613-2 and that include character content, consisting of a combination of graphic characters, control functions and space characters. + +For this type of content architecture, it defines those aspects of positioning and imaging that are applicable to the presentation of character content. It also defines specific character content architecture classes in terms of their structure, attributes, character repertoires, control functions and coding. + +## 7.6 ITU-T Rec. T.417 | ISO/IEC 8613-7: Raster graphics content architectures + +ITU-T Rec. T.417 | ISO/IEC 8613-7 applies to documents that are structured according to the architecture defined in ITU-T Rec. T.412 | ISO/IEC 8613-2 that include raster graphics content, consisting of a descriptive representation of pictorial information provided by an array of picture elements (pels), encoded according to facsimile, bitmap encoding or other multi-valued encodings. + +For this type of content architecture, it defines those aspects of positioning and imaging that are applicable to the presentation of raster graphics content. It also defines each class of raster graphics content architecture in terms of its structure, presentation attributes, content layout process, control functions and coding attributes. + +## **7.7 ITU-T Rec. T.418 | ISO/IEC 8613-8: Geometric graphics content architectures** + +ITU-T Rec. T.418 | ISO/IEC 8613-8 applies to documents that are structured according to the architecture defined in ITU-T Rec. T.412 | ISO/IEC 8613-2 that include geometric graphics content, consisting of a descriptive representation of picture description information as an ordered set of drawing elements such as lines, arcs, polygons, attributes for these drawing elements, elements that structure the content portion, and elements that among other things specify the precision of attribute and element values and control the imaging of the picture using the Computer Graphic Metafile (CGM) and its binary encoding defined in ISO/IEC 8632-1 and ISO/IEC 8632-3, respectively. + +For this type of content architecture, it defines those aspects of positioning and imaging that are applicable to the presentation of geometric graphics content. It also defines the geometric graphics content architecture class in terms of its structure, presentation attributes, the relevant CGM parameters, the content layout process, control functions and coding attributes. + +## **7.8 ISO/IEC 8613-10: Formal specifications** + +The use of ISO/IEC 8613-10 is applicable to ISO/IEC 8613 only. This text provides a formal specification of the concepts, structures, attributes and control functions expressed in natural language in other Parts of ISO/IEC 8613. These include: + +- ISO/IEC 8613-2: Document structures; +- ISO/IEC 8613-4: Document profile; +- ISO/IEC 8613-6: Character content architectures; +- ISO/IEC 8613-7: Raster graphics content architectures; +- ISO/IEC 8613-8: Geometric graphics content architectures. + +FODA uses a language called Information Modeling by Composition Language (IMCL) to describe ODA document structures, the document profile and the content architectures in terms of abstract information constructs. IMCL is also defined in ISO/IEC 8613-10. + +# **8 Inter-dependencies of the Specifications** + +If there is a requirement to interchange documents or generic-documents, it is necessary to use the following Specifications together: + +- ITU-T Rec. T.411 | ISO/IEC 8613-1: Introduction and general principles; +- ITU-T Rec. T.412 | ISO/IEC 8613-2: Document structures; +- ITU-T Rec. T.414 | ISO/IEC 8613-4: Document profile; +- ITU-T Rec. T.415 | ISO/IEC 8613-5: Open document interchange format. + +Additionally, it will be necessary to use one or more of the remaining Specifications, depending on the particular type of content to be interchanged. These include: + +- ITU-T Rec. T.416 | ISO/IEC 8613-6: Character content architectures; +- ITU-T Rec. T.417 | ISO/IEC 8613-7: Raster graphics content architectures; +- ITU-T Rec. T.418 | ISO/IEC 8613-8: Geometric graphics content architectures. + +If there is a requirement to interchange just the document profile, it is necessary to use the following Specifications together: + +- ITU-T Rec. T.411 | ISO/IEC 8613-1: Introduction and general principles; +- ITU-T Rec. T.414 | ISO/IEC 8613-4: Document profile; +- ITU-T Rec. T.415 | ISO/IEC 8613-5: Open document interchange format. + +# 9 Conformance + +Conformance to the ITU-T Rec. T.410-Series | ISO/IEC 8613 is defined in terms of conformance of a data stream that represents a document, a generic-document or a document profile. For the definition of conformance it is necessary to distinguish two cases: + +- no value is specified for the document profile attribute “document application profile”; +- the document profile attribute “document application profile” specifies the identifier of a document application profile. + +A document application profile shall be specified only if it is identified by an ASN.1 object identifier. This includes document application profiles defined in International Standards or ITU-T Recommendations, or registered by registration authorities; see Annexes B, C and D of CCITT Rec. X.208 | ISO/IEC 8824. ISO/IEC 8824 as published is not in Parts. + +In the absence of the specification of a document application profile, the data stream representing the document shall conform to the specifications in this series of Recommendations | International Standards. + +When the attribute “document application profile” is present in the document profile of a given document or generic-document, the data stream representing this document or generic-document is in conformance with the ITU-T Rec. T.410-Series | ISO/IEC 8613 if it conforms to the requirements above and to the additional constraints specified in the specified document application profile. + +# 10 Document application profile + +A document application profile is the specification of a combination of features that are defined in various Specifications of the ITU-T Rec. T.410-Series | ISO/IEC 8613. It is identified by a unique ASN.1 object identifier obtained in accordance with the rules in ISO/IEC 8824. + +In order to define a valid combination, the features shall be selected according to the rules given in 10.2. + +A document application profile shall include + +- one or more document architecture classes; +- one or more content architecture classes; +- the mandatory document profile attributes and optionally one or more permitted document profile attributes; +- an interchange format class. + +The document architecture features can be broken down into + +- a) three classes: + - 1) formatted document architecture (FDA); + - 2) processable document architecture (PDA); + - 3) formatted processable document architecture (FPDA); +- b) for each class its + - 1) constituents; +- c) for each constituent its + - 1) attributes; +- d) for each attribute its + - 1) classification (mandatory, non-mandatory, defaultable); + - 2) permissible values divided into basic, non-basic values; + - 3) default value, if the attribute is defaultable. + +###### ISO/IEC 8613-1:1994(E) + +The content architecture features depend primarily on the type of content. For each type of content, various content architecture classes exist (for example, for character content architectures the classes are: formatted character, processable character, and formatted processable character). The content architecture features are: + +- e) for each content architecture class its + - 1) presentation attributes; + - 2) coding attributes; + - 3) control functions; +- f) for each presentation attribute, coding attribute and control function its + - 1) permissible values divided into basic, non-basic values; + - 2) default value. + +The features of the document profile are its + +- g) attributes; +- h) for each attribute its + - 1) classification (mandatory, non-mandatory); + - 2) permissible values. + +The interchange formats that are permitted by the ITU-T Rec. T.410-Series | ISO/IEC 8613 are + +- i) the open document interchange format (ODIF) divided into + - 1) class A; + - 2) class B; +- j) and the SGML document interchange format (SDIF) which is applicable to ISO/IEC 8613 only. + +Annex F (informative) defines a standardized Proforma and a standardized Proforma notation that may be used for specifying document application profiles in a consistent manner. + +## 10.1 General principles for defining a document application profile + +A document application profile shall only place constraints on the previously listed features, it shall not extend them. + +A document application profile shall not allow the use of attributes for purposes beyond those defined in the ITU-T Rec. T.410-Series | ISO/IEC 8613. That is, a document application profile shall not modify in any way the semantics of the attributes defined in the ITU-T Rec. T.410-Series | ISO/IEC 8613. + +## 10.2 Rules for defining a document application profile + +The rules for defining a document application profile consist of rules for defining document architecture classes, content architecture classes, document profile attributes, and for selecting an interchange format class. + +### 10.2.1 Rules for defining a document architecture class + +ITU-T Rec. T.412 | ISO/IEC 8613-2 specifies three document architecture classes. These are formatted document architecture class, processable document architecture class and formatted processable document architecture class. + +For each of these classes, ITU-T Rec. T.412 | ISO/IEC 8613-2 defines which document structures may be used in documents that pertain to that class. These structures are classified as mandatory or optional. Each class also specifies which objects and object classes are applicable to these structures and objects and object classes are classified as mandatory or optional. The document architecture class also defines which attributes are applicable to those objects and object classes and ITU-T Rec. T.412 | ISO/IEC 8613-2 defines all permissible values and a standard default value for each defaultable attribute. + +A document application profile defines sets of document architecture class constraints concerning which structures, objects and object classes, attributes and attribute values are allowed to be contained in documents or generic-documents that pertain to that profile. + +For each document architecture class, only one set of document architecture class constraints shall be specified. For example, a document application profile cannot make use of two different sets of document architecture class constraints pertaining to the processable document architecture class (PDA). + +The rules for defining a document architecture class are given below. + +- a) A set of document architecture class constraints shall pertain to a particular document architecture class, that is, the set of document architecture class constraints shall make use of only those document structures, objects and object classes that pertain to the specified document architecture class. +- b) A set of document architecture class constraints shall specify which document structures pertain to that set of document architecture class constraints. Structures pertaining to the corresponding document architecture class that are mandatory shall be specified as mandatory in the set of document architecture class constraints. Structures specified as optional in the document architecture class may be specified as optional or mandatory in the set of document architecture class constraints or they may be disallowed from the document architecture class specification. +- c) When a document application profile allows the interchange of more than one document architecture class (for example, formatted, processable and formatted processable), the sets of document architecture class constraints shall be consistent. For example, the generic logical structure used in the sets of document architecture class constraints of processable form shall be identical to that used in the sets of document architecture class constraints of formatted processable form. +- d) A set of document architecture class constraints shall specify which objects and object classes pertain to that class. Objects and object classes that are mandatory for a particular structure shall be specified as mandatory in the set of document architecture class constraints. Objects and object classes that are specified as optional may be specified as optional or mandatory in the set of document architecture class constraints or they may be disallowed from the document architecture class specification. +- e) The document application profile shall specify for each document architecture class any restrictions that are applicable to the document structures. For example, the number of hierarchical levels allowed in a particular structure may be restricted or the specific structures allowed may be required to pertain to certain defined document classes. +- f) The document application profile shall specify, in the case of formatted document architecture class, whether the pages are to be composite or basic. +- g) The document application profile shall specify all nominal page sizes used in the document. In the case of each nominal page size not defined in ITU-T Rec. T.412 | ISO/IEC 8613-2, the document application profile shall also specify the dimensions of the assured reproduction area, and its position on the nominal page. + +In the case of nominal page sizes defined in ITU-T Rec. T.412 | ISO/IEC 8613-2, the document application profile shall not specify the dimensions of the assured reproduction area, or its position on the nominal page. These shall be the values defined in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +- h) The document application profile shall specify, in the case of formatted or processable document architecture classes, whether only one content portion or multiple content portions may be associated with basic objects. +- i) For each object or object class used, the document application profile shall specify for each document architecture class which attributes are applicable. These shall include the appropriate minimum set of attributes pertaining to each object type as defined in ITU-T Rec. T.412 | ISO/IEC 8613-2. +- j) For each permitted attribute, the document application profile shall specify the basic, default and non-basic (if any) values that are applicable. These values shall be taken from the range of permissible values specified in the attribute definitions in ITU-T Rec. T.412 | ISO/IEC 8613-2. +- k) The document application profile may classify attributes that are designated as being defaultable or non-mandatory in ITU-T Rec. T.412 | ISO/IEC 8613-2 as being mandatory for each document architecture class. The classification of mandatory attributes shall not be changed. +- l) The document application profile shall specify for each document architecture class which attributes may be included in the attribute “default value lists” and shall specify the object types for which a default value list may be specified. ITU-T Rec. T.412 | ISO/IEC 8613-2 gives a definition of the use of this attribute. + +### 10.2.2 Rules for defining a content architecture class + +Each specification of the ITU-T Rec. T.410-Series | ISO/IEC 8613 that caters for particular content types defines one or more content architecture classes that corresponds to that content type. The number of content architecture classes defined depends upon the particular content type. + +Each content architecture class definition consists of the specification of the following: + +- a set of presentation attributes; +- a set of content elements; +- a set of control functions, if applicable; +- the types of coding used; +- a set of coding attributes. + +For each presentation attribute and coding attribute, the content architecture class definition specifies the permissible values and a recommended default value. Similarly, the content architecture class definition specifies the permissible values and a recommended default value for the control functions (where applicable). + +Each content architecture class definition also specifies the basic component types that the content architecture class may be used in. + +A document application profile defines sets of architecture class constraints and content elements. The sets of architecture class constraints specify the presentation attributes, control functions (if applicable) and coding attributes, and their values, that pertain to the content elements. The document application profile may also define restrictions concerning the content elements and types of coding that may be used. + +For each content architecture class that is defined for a particular type of content, only one set of content architecture class constraints shall be specified. For example, a document application profile cannot make use of two different sets of content architecture class constraints pertaining to the formatted character content architecture class (CF). + +The rules for defining a content architecture class are given below. + +- a) A set of content architecture class constraints shall pertain to a particular content architecture class, that is, the presentation attributes, content elements, control functions (if applicable), types of coding and coding attributes specified by the content architecture shall be taken from those specified in the corresponding content architecture class. +- b) When a document application profile allows the interchange of more than one content architecture class pertaining to the same content type (for example, processable and formatted processable for character content architecture classes), the sets of content architecture class constraints shall be consistent. For example, the features used in the set of content architecture class constraints of formatted form shall be, when applicable, identical to those used in the set of content architecture class constraints of formatted processable form. +- c) Subject to the above restrictions, there is no further restriction on which presentation attributes, content elements, control functions, type of coding and coding attributes may be specified in a set of content architecture class constraints. +- d) The document application profile shall specify, for each permitted presentation attribute, control function and coding attribute, the basic, default and non-basic (if any) values that are applicable. These values shall be taken from the range of permissible values specified in the corresponding content architecture class. + +NOTE 1 – It is recommended that the default values used are those specified in other Specifications of the ITU-T Rec. T.410-Series | ISO/IEC 8613. These include: + +- ITU-T Rec. T.416 | ISO/IEC 8613-6: Character content architecture classes; + - ITU-T Rec. T.417 | ISO/IEC 8613-7: Raster graphics content architecture classes; + - ITU-T Rec. T.418 | ISO/IEC 8613-8: Geometric graphics content architecture classes. +- e) The document application profile shall specify which set or sets of content elements are applicable. These shall be taken from the permissible sets specified in the corresponding content architecture class. The type or types of coding allowable shall also be specified. + +NOTE 2 – There may be mandatory content elements (for example, BEGIN METAFILE or END METAFILE in the case of geometric graphics content type) that are to be present in every set of content elements specified by a document application profile. + +When using a document application profile, the ITU-T Rec. T.410-Series | ISO/IEC 8613 allows the interchange of documents containing content architecture classes that are not defined in this Recommendation | International Standard. The ITU-T Rec. T.410-Series | ISO/IEC 8613 does not define how such content architecture classes should be specified except that the interface between the content architecture and the document architecture should be defined as specified in ITU-T Rec. T.412 | ISO/IEC 8613-2. The only restriction imposed on the use of content architecture classes defined outside the ITU-T Rec. T.410-Series | ISO/IEC 8613 is that they are not allowed to be used if no document application profile identifier is indicated in the document profile (see clause 9). + +### 10.2.3 Rules for defining a document profile + +ITU-T Rec. T.414 | ISO/IEC 8613-4 defines all attributes that may be specified for use in a document profile. The rules for specifying how document profile attributes may be used in a document profile of a document application profile are given below. + +- a) The document application profile may specify any document profile attribute defined in ITU-T Rec. T.414 | ISO/IEC 8613-4. It shall not specify attributes not defined in ITU-T Rec. T.414 | ISO/IEC 8613-4. +- b) The classification of mandatory attributes shall not be changed. That is, the document application profile shall specify the mandatory document profile attributes as defined in ITU-T Rec. T.414 | ISO/IEC 8613-4. +- c) The document application profile may classify attributes that are designated as non-mandatory in ITU-T Rec. T.414 | ISO/IEC 8613-4 as being mandatory for that profile. +- d) The document application profile shall specify attribute values taken from the range of permissible values defined in ITU-T Rec. T.414 | ISO/IEC 8613-4. +- e) The document application profile may specify additional restrictions on the use of certain attributes and limit the values applicable to these attributes. +- f) The document application profile shall not modify the semantics of the absence of attributes from those semantics specified in ITU-T Rec. T.414 | ISO/IEC 8613-4. + +### 10.2.4 Rules for selecting the interchange format class + +ITU-T Rec. T.415 | ISO/IEC 8613-5 defines the valid interchange format classes that may be used for interchanging a document or a generic-document. It also defines the restrictions on the use of these interchange format classes. Only one interchange format class may be specified in a document application profile. No other restriction shall be specified concerning the use of an interchange format class in a document application profile. + +NOTE – This requirement does not preclude applications in a mixed office and publishing environment, in which documents could be interchanged using class A, class B or SDIF. Such interchange is effected by defining two document application profiles that differ only in their interchange format class; for example, by creating a single specification document with individual ASN.1 object identifiers for class A and SDIF interchange. The use of SDIF is applicable to ISO/IEC 8613 only. Interchange class B is provided only for use with a document application profile for the interchange of Group 4 facsimile documents as documented in CCITT Rec. T.503. + +# Annex A + +## References to other standards and registers + +(This annex does not form an integral part of this Recommendation | International Standard) + +The following Recommendations and International Standards are given for information. They are not required for the application of this series of Recommendations | International Standard: + +## A.1 Paired Recommendations | International Standards equivalent in technical content + +- CCITT Recommendation X.200 (1988), *Reference Model of Open Systems – Open Systems Interconnection – Basic Reference Model*. +- ISO 7498:1984, *Information processing systems – Open Systems Interconnection – Basic Reference Model*. + +## A.2 Additional references + +- ISO 216:1975, *Writing paper and certain classes of printed matter – Trimmed sizes – A and B series*. +- ISO/IEC TR 10183 +- *ISO International register of character sets to be used with escape sequences*. +- *ISO International register of graphic character subrepertoires*. +- ECMA 101:1988, *Open Document Architecture*. +- ANSI X3.151:1987, *Bond papers and index bristols – Basic sheet sizes and standard stock sizes*. +- JIS P 0138:1961, *Trimmed sizes of paper*. +- CCITT Recommendation T.61:1984, *Character repertoire and coded character sets for the international Teletex service*. +- CCITT Recommendation T.73:1984, *Document interchange protocol for the telematic services*. + - NOTE – CCITT Recommendation T.73 is no longer valid. +- CCITT Recommendation T.400:1988, *Introduction to document architecture, transfer and manipulation*. +- CCITT Recommendation T.503:1988, *A document application profile for the interchange of Group 4 facsimile documents*. + +# Annex B + +## Relationships with other standards + +(This annex does not form an integral part of this Recommendation | International Standard) + +## B.1 Transfer standards + +Documents structured and represented according to the ITU-T Rec. T.410-Series | ISO/IEC 8613 can be transferred using the functions defined in the following standards and other similar standards. + +- ISO 8378-1:1986, *Information processing – Data interchange on 130 mm (5.25 in) flexible disk cartridges using modified frequency modulation recording at 7958 f/track, 3.8 t/mm (96 tpi), on both sides – Part 1: Dimensional, physical and magnetic characteristics.* +- ISO 8571:1988, *Information processing systems – Open System Interconnection – File Transfer, Access and Management.* +- ISO 8630-1:1987, *Information processing – Data interchange on 130 mm (5.25 in) flexible disk cartridges using modified frequency modulation recording at 13262 f/track, on 80 tracks on each side – Part 1: Dimensional, physical and magnetic characteristics.* +- ISO 8860-1:1987, *Information processing – Data interchange on 90 mm (3.5 in) flexible disk cartridges using modified frequency modulation recording at 7958 f/track, on 80 tracks on each side – Part 1: Dimensional, physical and magnetic characteristics.* +- ISO/IEC 10021:1990, *Information technology – Text Communication – Message Oriented Text Interchange Systems (MOTIS).* + +The interchange format defined in the ITU-T Rec. T.410-Series | ISO/IEC 8613 constitutes an application context as defined in: + +- ISO 8822:1988, *Information processing systems – Open Systems Interconnection – Connection oriented presentation service definition.* + +The abstract syntax of the application context is defined in the ITU-T Rec. T.410-Series | ISO/IEC 8613-5. ISO/IEC 8613-5 also specifies that an interchanged document can be represented by the interchange format defined in: + +- ISO 9069:1988, *Information processing – SGML support facilities – SGML Document Interchange Format (SDIF).* + +The use of SDIF is applicable to ISO/IEC 8613 only. + +## B.2 Other standards + +For document interchange on magnetic disk the following part of ISO 7487 should be used: + +- ISO 7487-1:1985, *Information processing – Data interchange on 130 mm (5.25 in) flexible disk cartridges using modified frequency modulation recording at 7958 f/track, 1.9 t/mm (48 tpi), on both sides – Part 1: Dimensional, physical and magnetic characteristics.* + +# Annex C + +## Recording of documents in conformance with ISO/IEC 8613 on interchangeable storage media + +(This annex forms an integral part of this International Standard) + +This annex is applicable to ISO/IEC only. + +## C.1 Introduction + +This annex specifies the method of recording documents in conformance with ISO/IEC 8613 on volume and file structures of interchangeable storage media in conformance with international standards for volume and file structures, for the purpose of interchanging such documents between users of information processing systems. + +Specifically this annex defines how to record documents in conformance with ISO/IEC 8613 when: + +- a flexible disk cartridge is employed as an interchangeable storage medium with its volume and file structure in conformance with ISO 9293; +- a CD-ROM is employed as an interchangeable storage medium with its volume and file structure in conformance with ISO 9660. + +## C.2 Conformance + +Recorded document conformance is defined in terms of storage representation conformance, which is specified by the mode of representation of a conforming data stream on an interchangeable storage medium. + +A recorded document shall be in conformance with this annex, when the representation of its data stream on a volume and file structure satisfies the requirements specified in C.4. + +A prerequisite of such conformance is conformance of the interchangeable storage medium to a standard for volume and file structure. The standard for volume and file structure used in conjunction with this annex is subject to agreement between the originator and the recipient of the medium. + +## C.3 References + +This annex refers to the following documents: + +- ISO 9293:1987, *Information processing – Volume and file structure of flexible disk cartridges for information interchange.* +- ISO 9660:1988, *Information processing – Volume and file structure of CD-ROM for information interchange.* + +## C.4 Procedure for recording documents on interchangeable storage media + +### C.4.1 Representation and encoding of documents + +A document recorded on an interchangeable storage medium shall be in conformance with ISO/IEC 8613. The data stream comprising the recorded document shall be represented using either ODIF or ODL/SDIF as defined in parts 5, 6, 7 and 8 of ISO/IEC 8613 and in accordance with ISO 8825/IEC and ISO 9069. + +A document shall be recorded according to an international standard for volume and file structure of the interchangeable storage medium. + +- A document shall be recorded in the data space of a file. +- The international standard for volume and file structure may permit a file to be recorded on more than one volume. If a document is recorded over more than one volume, the document shall be recorded over more than one volume as a file in conformance with the standard for volume and file structure. +- The international standard for volume and file structure may permit a file to be recorded on no more than one volume. If a document is recorded over more than one volume, the document shall be recorded in more than one part and each part of the document shall be recorded as a separate file in conformance with the standard for volume and file structure. + +NOTE – If the document comprises more than one file, the method of identifying the sequence of the successive files is not specified by this annex. + +### C.4.3 Recording of the data stream + +The bytes in the data space of a file shall be treated as if they were numbered with consecutive integers assigned in an ascending sequence. The numbering shall start with the first byte of the data space of a file as specified in the relevant standard for volume and file structure. + +The successive octets of the data stream comprising an encoded document or part of an encoded document shall be recorded in the consecutive bytes of the data space of a file starting from the first byte of the data space. + +If the international standard for volume and file structure for an interchangeable storage medium requires the recording of the file as an organized set of records, the document shall be recorded in the file as a set of records of a record type specified in the international standard for volume and file structure. + +### C.4.4 Specification for recording on flexible disk cartridges in conformance with ISO 9293 + +The successive octets of the data stream comprising an encoded document or part of an encoded document shall be recorded in the consecutive bytes of the file space of a file section starting from the first byte of the file space. + +#### NOTES + +1 For a file recorded over more than one volume, file section is that part of the file that is recorded on any one volume. The term “file” in ISO 9293 is equivalent to the term “file section” in this clause. + +2 If the file comprises more than one file section, the method of identifying the sequence of the successive file sections is not specified by this annex. + +3 The Name Extension field of the directory entry that identifies the file or file section is not specified by this annex and is specified by the local system that creates the file or file section. To identify files and file sections that conform to this annex, it is recommended that local systems consider using ODA for the Name Extension field, when the coded graphic character set that applies to the Name Extension field includes these graphic characters. + +### C.4.5 Specification for recording on CD-ROM in conformance with ISO 9660 + +The generic specification in C.4.2 and C.4.3 can be applied directly in this case. + +NOTE – The File Name Extension field is not specified by this annex and is specified by the local system that creates the file. However, it is recommended that ODA be used as the extension for the file in conformance with this annex when the coded graphic characters permitted in a File Identifier include the Latin alphabet. + +# Annex D + +## Principles for the assignment of ASN.1 object identifier values + +(This annex forms an integral part of this Recommendation | International Standard) + +Values of ASN.1 object identifiers are assigned in various specifications parts of the ITU-T Rec. T.410-Series | ISO/IEC 8613. The assignment of these values is based on the following principles: + +- a) The value of the first component is 2, representing “joint-iso-ccitt”. +- b) The value of the second component is 8, designating the area of joint ISO-TSS work “document architecture”. +- c) The value of the third component is 0, 1, 2, 3 or 4, identifying one of the following categories of object identifier values assigned within this area of work: + - 1) 0 – object identifier value to be used as a part of an ASN.1 external data type; + - 2) 1 – object identifier value to be used as a part of an ASN.1 module identifier; + - 3) 2 – object identifier value for the identification of a content architecture class; + - 4) 3 – object identifier value for the identification of a type of coding; + - 5) 4 – object identifier value for the identification of a document application profile. +- d) The meaning of the fourth component and that of the fifth component, if any, depends on the value of the third component as follows: + - 1) if the value of the third component is 0, the fourth component identifies a particular external data type; values of the fourth component are assigned in ITU-T Rec. T.415 | ISO/IEC 8613-5; in this case, there is no fifth component; + - 2) if the third component is 1, 2, or 3, the fourth component identifies the ITU-T Rec. T.410-Series | ISO/IEC 8613 Specification in which the value of the fifth component is assigned: + - 1) ITU-T Rec. T.411 | ISO/IEC 8613-1; + - 2) ITU-T Rec. T.412 | ISO/IEC 8613-2; + - 4) ITU-T Rec. T.414 | ISO/IEC 8613-4; + - 5) ITU-T Rec. T.415 | ISO/IEC 8613-5; + - 6) ITU-T Rec. T.416 | ISO/IEC 8613-6; + - 7) ITU-T Rec. T.417 | ISO/IEC 8613-7; + - 8) ITU-T Rec. T.418 | ISO/IEC 8613-8. + - 3) if the value of the third component is 4, the fourth component identifies a document application profile and the fifth component identifies a version number of this document application profile. + +# Annex E + +## Use of MHS to interchange documents conforming to the ITU-T Rec. T.410-Series | ISO/IEC 8613 + +(This annex forms an integral part of this Recommendation | International Standard) + +## E.1 ODA identification in the P1 Protocol of MHS + +Documents shall be identified by a set of ASN.1 object identifiers as externally-defined encoded-information-types. One member shall always be the ASN.1 object identifier for ODA, the other members shall be one or more ASN.1 object identifiers for the document application profiles to which the message body parts conform. + +| | | +|-------------------------------------|-----------------------| +| ODA document | { 2 8 0 0 } | +| Document Application Profile | { See Note 2 } | +| ... .. | { . . . . } | +| ... .. | { . . . . } | +| ... .. | { . . . . } | + +###### NOTES + +1 When using [ MHS/MOTIS ] to transfer documents conforming to ODA, the MTS may perform format conversion. Format conversion of ODA documents may result in loss of information. If format conversion is not appropriate, this should be indicated by the sender when submitting a message with ODA body parts to [ MHS/MOTIS ]. + +2 These document application profiles ASN.1 object identifiers are those defined for TSS | ISO/IEC. Other organizations shall use object identifiers as appropriate. + +## E.2 ODA identification in the P2 Protocol of MHS + +Documents conforming to ODA shall be identified as ODA extended body parts. Each extended body part shall contain parameter information about the applicable document application profile and the document architecture class. + +NOTE – ODA body parts can be mixed with non-ODA body parts in a P2 Body. + +The module for specifying the ODA Body Parts is described below: + +**IPMSExtendedBodyPartTypeOda { joint-iso-ccitt(2) oda(8) modules(1) part(0) extended-body-part-type-oda(0) }** + +**DEFINITIONS IMPLICIT TAGS ::=** + +**BEGIN** + +*-- Prologue --* + +**EXPORTS** + +**oda-body-part, +OdaBodyPartParameters, +OdaData;** + +**IMPORTS** + +**Interchange-Data-Element +FROM Interchange-Data-Elements { 2 8 1 5 5 } +EXTENDED-BODY-PART-TYPE +FROM IPMSInformationObjects { joint-iso-ccitt(2) mhs-motis(6) ipms(1) modules(0) +information- +objects(2) };** + +**oda-body-part EXTENDED-BODY-PART-TYPE** + +**PARAMETERS OdaBodyPartParameters IDENTIFIED BY id-et-oda-param** + +**DATA OdaData** + +**::= id-et-oda-data** + +*-- Abstract syntax for ODA body part parameters shall appear in the parameter elements of an IPM +ExternallyDefinedBodyPart --* + +``` + +OdaBodyPartParameters ::= SET { + document-application-profile [0] OBJECT IDENTIFIER, + -- This object identifier value shall also be used in the MTS ExternalEncodedInformationType in addition to the + id-et-oda-data object identifier -- + document-architecture-class [1] INTEGER { + formatted (0), + processable (1), + formatted processable (2) } } + -- Abstract syntax for ODA data shall appear in the data element of an IPM ExternallyDefinedBodyPart -- +OdaData ::= SEQUENCE OF Interchange-Data-Element + id-et-oda-param OBJECT IDENTIFIER ::= { 2 8 1 1 2 }, + -- identifies the Abstract Syntax for ODA bodypart parameters using the ASN.1 basic encoding rules -- + id-et-oda-data OBJECT IDENTIFIER ::= { 2 8 1 1 1 } + -- identifies the Abstract Syntax for ODA data using the ASN.1 basic encoding rules -- +END -- of IPMSExtendedBodyPartTypeOda -- + +``` + +# Annex F + +## Document Application Profile Proforma and Notation + +(This annex does not form an integral part of this Recommendation | International Standard) + +## F.1 Introduction + +This annex defines a standardized Proforma for the specification of document application profiles. It also defines a recommended notation for describing the technical specifications of document application profiles. + +The use of both Proforma and notation is intended to + +- aid clarity and remove ambiguity in the definition of document application profiles; +- ensure that all necessary information is included in the document application profile and is correctly specified; +- aid comparison between document application profiles; +- aid verification that a particular document application profile conforms to the rules defined in clause 10 for the specification of document application profiles. + +## F.2 Proforma + +This subclause contains two parts: a document application profile proforma outline in F.2.1 and a description of the material that should be contained in the clauses of any particular document application profile in F.2.2. + +### F.2.1 Document application profile proforma outline + +- 0 Introduction +- 1 Scope and field of application +- 2 References +- 3 Definitions and abbreviations +- 4 Relationships to other document application profiles +- 5 Conformance +- 6 Characteristics supported by this document application profile + - 6.1 Overview + - 6.2 Logical constituents + - 6.3 Layout constituents + - 6.4 Document layout control + - 6.5 Content layout and imaging control + - 6.6 Miscellaneous features + - 6.7 Document management features +- 7 Specification of constituent constraints + - 7.1 Document profile constraints + - 7.2 Logical constituent constraints + - 7.3 Layout constituent constraints + - 7.4 Layout style constraints + - 7.5 Presentation style constraints + - 7.6 Content portion constraints + - 7.7 Additional usage constraints +- 8 Interchange Format + +### **F.2.2 Document application profile clause description** + +Where possible, a document application profile should follow the terminology defined in the ITU-T Rec. T.410-Series | ISO/IEC 8613 and the naming convention used in F.3.6 (Table F.1) and F.3.7 (Table F.2). + +#### **F.2.2.1 Clauses 0-3** + +Clauses 0 to 3 are intended to be supplied in accordance with TSS | ISO/IEC Rules for the drafting and presentation of Recommendations | International Standards. + +#### **F.2.2.2 Clause 4** + +Clause 4 describes how the document application profile relates to other document application profiles; for example in its hierarchical relationship with other document application profiles. + +#### **F.2.2.3 Clause 5** + +Clause 5 details conformance requirements, specified in terms of data stream representations of documents conforming to the document application profile. This clause should also contain further information concerning the use of the document application profile in applications. + +#### **F.2.2.4 Clause 6** + +The purpose of clause 6 is to specify, in natural language form, the constituent constraints that are formally defined in clause 7 of a document application profile and that may be used to represent documents in accordance with the document application profile. The specification in clause 6 should be complete. That is, it should specify all the characteristics of each constituent constraint including any usage constraints that are applicable. Such usage constraints shall be adhered to when representing documents in accordance with the document application profile. + +In addition, clause 6 should contain a description of the typical use of the constraints to provide guidance as to how a data stream conforming to the document application profile is to be interpreted. This should be described in terms of a set of abstract features that are supported by the document application profile. + +The subclauses given for clause 6 in F.2.1 are for guidance only since the requirements may differ depending on the document application profile. Following an overview, the logical and layout constituents are described in 6.2 and 6.3 in a document application profile respectively. The content independent layout features that are supported by the document application profile are described in 6.4. This describes the controls available for positioning content within pages and frames, for example, offsets between the content and frame boundaries, separation between blocks of content and page breaks. + +The layout and presentation features that pertain to each content type that is supported by the document application profile are described in 6.5. Miscellaneous features supported by the document application profile that are not covered elsewhere, such as automatic page or paragraph numbering, are described in 6.6. Document management features that are supported are described in 6.7. + +#### **F.2.2.5 Clause 7** + +This clause contains a definition of the constituents that should be used to represent a document that conforms to the document application profile. These definitions shall be in accordance with the notation defined in subclause F.3. In clause 7, 7.1 should contain the document profile constraints, 7.2 the logical constituent constraints, 7.3 the layout constituent constraints, 7.4 the layout style constraints, 7.5 the presentation style constraints and 7.6 the content portion constraints. All of the additional usage constraints not covered in 7.1 to 7.6 should be contained in 7.7. The constraints contained in 7.7 should be specified in the appropriate natural language and/or using the same formal specification techniques as are used in the Formal Specification of the ITU-T Rec. T.410-Series | ISO/IEC 8613. Such constraints could also be included as comments in affected constituent constraints. + +It is recommended that 7.1 to 7.6 in clause 7 each be divided into three further parts: + +7.x.1 Macro definitions + +7.x.2 Factor constraints + +7.x.3 Constituent constraints + +7.x.1 and 7.x.2 contain, respectively, any macro definitions (see F.3.3.1) and factor constraints (see F.3.3.2) that pertain to the constituent constraints defined in 7.x.3. + +#### F.2.2.6 Clause 8 + +This clause specifies the interchange classes selected for the document application profile. It is possible to specify, in a document application profile description based on the ITU-T Rec. T.410-Series, that ODIF is used for document interchange. It is possible to specify, in a document application profile description based on ISO/IEC 8613, that ODIF or ODL/SDIF (or both) are used for the interchange of documents. The use of ODL/SDIF is applicable to ISO/IEC 8613 only. + +## F.3 Proforma and notation + +This subclause provides production rules for the specification of the constituent constraints allowed in a document application profile. + +F.3.1 gives an overview of how clause 7 of the document application profile is formally defined according to the notation and production rules specified in this annex. + +The production rules are defined according to a context free grammar using a Backus-Naur-Form (BNF) which makes use of the symbols defined in F.3.2.1. The terminal symbols used in the notation are defined in F.3.2.2. + +F.3.3 contains the description and format of the production rules used for the specification of the set of constituent constraint definitions which constitutes clause 7 of a document application profile. This includes a macro facility described in F.3.3.1. For convenience the production rules are listed in full in F.3.4. F.3.5 provides an example of the recommended style of layout for document application profile specifications. + +F.3.6 contains a table of the ITU-T Rec. T.410-Series | ISO/IEC 8613 attribute and (sub-)parameter names and their associated Document Application Profile Proforma Notation data types. This table provides a set of unique names that will facilitate the construction of clause 7 of a document application profile that is consistent with clause F.3. F.3.7 provides a similar table for the character content architecture control functions, that is, a list of abbreviated control function names and their associated Document Application Profile Proforma Notation data types. + +### F.3.1 Overview + +A document application profile defined in accordance with this annex consists of a set of constituent constraint definitions. The section numbers and headers in clause 7 of a Document Application Profile Proforma do not form part of the notation. + +A constituent constraint definition consists of a number of attribute constraint definitions for attributes that are either specified explicitly for the constituent or are applicable to the constituent (for example, layout directives in the case of object descriptions). Thus a document application profile specification consists of a set of constituent constraint definitions relating to the document profile, object and object class descriptions, layout styles, presentation styles and content portion descriptions. + +A constituent constraint definition specifies which attributes shall be specified in instances of that constituent, which attributes should be optionally specified and which attributes are disallowed. + +Also, a constituent constraint definition specifies which values should be unconditionally specified for each attribute as it specifies the basic values that are applicable. The non-basic values that are allowed (if any) and any default values which are other than the recommended values in the ITU-T Rec. T.410-Series | ISO/IEC 8613 are specified in the constituent constraint definition relating to the document profile. + +When defining a document application profile using this Specification Proforma, it is necessary to take into account + +- a) The rules for defining document application profiles as specified in clause 10 of this Specification. In particular, attributes specified as mandatory in the ITU-T Rec. T.410-Series | ISO/IEC 8613 shall be specified as required in the corresponding constituent constraint definitions in the document application profile. Attributes classified as defaultable or non-mandatory in the ITU-T Rec. T.410-Series | ISO/IEC 8613 should be specified as permitted or required in the corresponding document application profile constituent constraint definitions. +- b) A document application profile specification may disallow the occurrence of a defaultable attribute in a constituent. An application shall take into account all defaultable attributes that are applicable to each constituent in the document, irrespective of whether the document application profile allows the occurrence of those attributes or not. + +- c) A document application profile specification does not repeat requirements already specified in the ITU-T Rec. T.410-Series | ISO/IEC 8613 although these requirements automatically apply to the documents conforming to the document application profile. As a consequence, a document application profile specification does not provide information relating to the internal consistency of a document and does not include any additional information that will ensure the internal consistency of a document. + +### F.3.2 Description of the notation + +#### F.3.2.1 Symbols used in the meta-language + +The symbols listed and defined below are used to define the production rules contained in F.3.3 which specify the format of a document application profile specification. + +- ::=** is used to specify that the string of symbols on the right side is to be substituted for the non-terminal symbol on the left side. +- |** is used to separate alternatives. +- < >** is used as a pair of symbols to delimit a non-terminal symbol. +- is used as a paired pair of symbols to delimit a comment string. + NOTE – A comment string is used for describing symbols (non-terminals) which are not formally defined by further production rules but are defined in the ITU-T Rec. T.410-Series | ISO/IEC 8613; e.g. **{ attribute-name }** -- *a name that identifies an attribute from the ITU-T Rec. T.410-Series | ISO/IEC 8613, see F.3.6 (Table F.1)* -- +- { }** is used as a pair of symbols to delimit a syntactical unit. +- [ ]** is used as a pair of symbols to delimit an optional syntactical unit, i.e. which may be present or absent. +- ...** is used following a syntactical unit to indicate that the syntactical unit may be repeated, e.g. **[ ]...** +- ' '** is used as a pair of symbols to delimit a terminal symbol. + +A syntactical unit is either a non-terminal symbol or a sequence of symbols enclosed in either curly brackets **{ }** or square brackets **[ ]**. + +These symbols are also used in document application profile defined production rules used for the definition of allowed values for attributes such as “bindings” and “generator for subordinates”. However, an exception to this is that the apostrophe symbols used to delimit a terminal symbol are not used in document application profile defined production rules. + +#### F.3.2.2 Terminal symbols used in the notation (Reserved Names) + +The following is a list of the terminal symbols used in the notation defined in F.3.3. It does not include those terminal symbols in ITU-T Rec. T.412 | ISO/IEC 8613-2 which are used in some of the constraint specifications. + +| | | +|----------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| GENERIC | announces attributes specified for object classes. | +| SPECIFIC | announces attributes specified for objects. | +| SPECIFIC_AND_GENERIC | announces attributes specified for object classes, objects or both. | +| REQ | announces attributes or parameters that shall be specified for the associated constituent or attribute. | +| PERM | announces defaultable and non-mandatory attributes or parameters that may be specified for the associated constituent or attribute. If the attribute/parameter is defaultable, then the attribute/parameter shall have a value within the specified value range, either explicitly specified in the constituent/attribute or derived using the defaulting rules specified in ITU-T Rec. T.412 ISO/IEC 8613-2. If the attribute/parameter is non-mandatory, then the constraint on the value is applicable only if the attribute/parameter is specified in the constituent/attribute. | +| DIS | announces defaultable attributes or parameters that shall not be specified for the associated constituent or attribute. The value of that attribute/parameter obtained by using the defaulting rules specified in ITU-T Rec. T.412 ISO/IEC 8613-2 shall be within the specified value range. | + +| | | +|--------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------| +| MUL | announces a repetitive group of attributes or parameters. | +| PMUL | announces an optionally repetitive group of attributes or parameters. | +| FACTOR | announces a common set of constraints. | +| DEFINE | announces a string substitution macro. | +| CASE | announces a conditional selection mechanism that depends on another attribute value. | +| OF | announces a list of possible attribute values in the CASE conditional selection mechanism. | +| ANY_VALUE | is used to denote that any attribute or (sub-)parameter value may be specified that is permitted in the ITU-T Rec. T.410-Series ISO/IEC 8613. | +| OBJECT_CLASS_ID_OF | is used to specify any object class identifier from the set of instances of a particular constituent constraint. | +| OBJECT_ID_OF | is used to specify any object identifier from the set of instances of a particular constituent constraint. | +| STYLE_ID_OF | is used to specify any style identifier from the set of instances of a particular style constraint. | +| SUB_ID_OF | is used to specify, implicitly, a subordinate object identifier from the set of instances of a particular constituent constraint. | +| CONTENT_ID_OF | is used to specify, implicitly, a content portion identifier from the set of instances of a particular constituent constraint. | +| VIRTUAL | is used to specify that the attribute value is specified in another constraint. | +| NOVR | is used to specify that an attribute or parameter value derived from an object class shall not be overridden in corresponding objects. | +| SUPERIOR | is used when referencing an attribute, in a conditional selection mechanism, to specify the first superior constituent constraint containing the attribute. | +| VOID | is used when referencing an attribute to specify the case when the attribute is absent. | +| ANY_STRING | is used to specify any character string allowed by the ITU-T Rec. T.410-Series ISO/IEC 8613 consistent with the document application profile. | +| ANY_INTEGER | is used to specify any integer value allowed by the ITU-T Rec. T.410-Series ISO/IEC 8613. | +| ASN.1 | is used to announce an ASN.1 object identifier value. | +| EXCEPT | is used to specify a range of values that shall not be used. | +| CHARACTER | is used to specify any graphic character allowed by the document application profile. | +| RASTER | is used to specify any raster content allowed by the document application profile. | +| GEOMETRIC | is used to specify any geometric content allowed by the document application profile. | +| ESC | is used to specify an escape sequence allowed by the document application profile. | +| + | is used to indicate one or more occurrences of an attribute value. | +| { } | is used as a pair of symbols to delimit a syntactical unit. | +| [ ] | is used as a pair of symbols to delimit an optional syntactical unit. | +| ( ) | is used as a pair of symbols to delimit parameters in functions and macros. | +| <> | is used as a pair of symbols to delimit a non-terminal symbol. | +| -- -- | is used as a paired pair of symbols to delimit a comment in a document application profile. Comments shall not be nested. | + +| | | +|---------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ; | is used to terminate a simple attribute specification. | +| | is used to separate alternatives. | +| : | is used to separate attribute or (sub-)parameter values in a case specification from the associated attribute or (sub-)parameter specification. | +| , | is used to separate elements of a set. | +| .. | is used to specify a range of integers or characters. | +| # | is used to announce a parameter or a control function name. | +| " " | is used as a pair of symbols to delimit a character string. If a double quotation mark is to be used within the character string, then it shall be announced with another double quotation mark. | +| 'space' | is used to separate elements of a sequence and terminal symbols in general. | +| ... | is used to indicate that an element may be repeated. | +| \$ | is used to announce a macro substitution. | +| = | is used to specify equality. | +| > | is used to specify greater than. | +| < | is used to specify less than. | +| >= | is used to specify greater than or equal to. | +| <= | is used to specify less than or equal to. | +| / | is used to separate character code table column and row positions in an escape sequence constraint specification. | +| \ | is used, within character strings, to delimit non-printable strings. | + +In addition to the above a space is used as a terminal symbol to indicate the presence of one or more spaces separating integer values in the specification . + +### F.3.3 The document application profile specification + +A document application profile specification consists of intermixed macro definitions and constraint definitions. The format of the macro definitions and the method of substitution is described in F.3.3.1. F.3.3.2 defines the format of the constraint definitions and F.3.3.3 defines the format of the individual attribute specifications which make up a constraint definition. + +Thus the format of the document application profile specification is as follows: + +** ::= { | }...** + +#### F.3.3.1 Format of macro definition + +The macro facility provides a shorthand mechanism for the notation. For each macro definition of the form DEFINE (S, "..."), corresponding text or additional macros are substituted for all strings of the form: \$\$S where S is a unique macro name identifying the macro. The string substitution macros shall be fully expanded to a defined single string of characters lexically inserted into the corresponding part of the notation. + +The format of a macro definition is as follows : + +** ::= 'DEFINE' '(' ',' ')'** + +**** -- A unique name that identifies a document application profile macro name. It consists of a sequence of one or more characters. The first character shall be a letter ('a'..'z', 'A'..'Z'). The remaining characters shall be letters ('a'..'z', 'A'..'Z'), digits ('0'..'9') or hyphens ('-'). Uppercase and lowercase letters are not significant but their use throughout a document application profile should be consistent. -- + +** ::= ** + +Macros shall be defined before their macro names are used. Macros may be repeated for readability but should not be redefined. + +EXAMPLE 1 (in recommended style) + +\$S is expanded to the string "abc" with the macro definitions: + +``` +DEFINE (S, "$T") +``` + +``` +DEFINE (T, "abc") +``` + +EXAMPLE 2 (in recommended style) + +With the following two macro definitions: + +``` +DEFINE (CHAPTER, " +``` + +``` + ::= SEQ ( <body>) + | <body> + ; + <title> ::= "Chapter1" + ; +``` + +``` +$BODY +") +``` + +``` +DEFINE (BODY, " + <body> ::= SEQ (<section> ... <ending>) + ; +") +``` + +\$CHAPTER would be expanded to : + +``` +<chapter> ::= SEQ (<title> <body>) + | <body> + ; +<title> ::= "Chapter1" + ; +<body> ::= SEQ (<section> ... <ending>) + ; +``` + +#### F.3.3.2 Format of constraint definitions + +A constraint definition consists of a document application profile constituent constraint or a factor constraint. + +A document application profile constituent constraint definition specifies the constraints on the presence and values of attributes that are applicable to that particular constraint. + +A factor constraint definition specifies constraint information that is common to one or more of the document application profile constituent constraints. + +The format of the constraint definition is as follows: + +``` +<constraint-definition> ::= <constraint-name> '{' <constraint> '}' +``` + +##### F.3.3.2.1 Constituent and factor names + +Document application profile constituent names and factor names are used to identify document application profile constituent constraints and factor constraints respectively within a document application profile specification. + +The format of a constraint name is as follows: + +``` +<constraint-name> ::= <constituent-name> | <factor-name> +``` + +A document application profile constituent name consists of one or two fields separated by the colon character ":". The first field applies to the constituent itself. The second field (if used) identifies factor constituent constraints that specify additional constraints imposed on that constituent. + +A factor name is structured similarly to a document application profile constituent name. The first field in the name is used to identify the factor constituent constraint. The second field (if used) identifies another factor constituent constraint which contains additional constraints that are applicable to that factor constituent constraint. + +| | | +|---------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b><constituent-name></b> | <b>::= <c-name> [ <factor-reference> ]</b> | +| <b><c-name></b> | -- A unique name that identifies a document application profile constituent constraint. It consists of a sequence of one or more characters. The first character shall be an uppercase letter ('A'..'Z'). The remaining characters shall be uppercase letters ('A'..'Z'), lowercase letters ('a'..'z'), digits ('0'..'9') or hyphens ('-'). -- | +| <b><factor-reference></b> | <b>::= ':' <f-name></b> | +| <b><factor-name></b> | <b>::= 'FACTOR' <f-name> [ <factor-reference> ]</b> | +| <b><f-name></b> | -- A unique name that identifies a document application profile factored constraint. It consists of a sequence of one or more characters. The first character shall be an uppercase letter ('A'..'Z'). The remaining characters shall be uppercase letters ('A'..'Z'), digits ('0'..'9') or hyphens ('-'). -- | + +##### F.3.3.2.2 Constraint specifications + +If a constraint specification relates to an object or object class, the constraint specification is divided into sections (up to three sections). These are the generic part, the specific part and the specific\_and\_generic part. They respectively define the constraints that are applicable to object classes, to objects, and to both objects and object classes for which the constraint specification applies. + +If the constraint specification relates to some other constituent of the document, for example, the document profile, a style or a content portion, then the constraint specification consists of an attribute expression. + +Each section consists of an attribute expression specification. + +The format of the constraint specification is as follows: + +| | | +|---------------------------|---------------------------------------------------------------------------------------------| +| <b><constraint></b> | <b>::= <section>... <attribute-expr-a></b> | +| <b><section></b> | <b>::= { 'GENERIC' 'SPECIFIC' 'SPECIFIC_AND_GENERIC' } ':' <attribute-expr-a></b> | + +#### F.3.3.3 Attribute expression specifications + +An attribute expression specification is used to separate a list of attributes and to allow a choice between groups of attributes. + +| | | +|---------------------------------|-------------------------------------------------------------------------| +| <b><attribute-expr-a></b> | <b>::= <attribute-expr-b> [ ' ' <attribute-expr-b> ]...</b> | +| <b><attribute-expr-b></b> | <b>::= <attribute-expr-c> [ ',' <attribute-expr-c> ]...</b> | + +An attribute expression type c may take one of two forms : + +- case attribute value range specification; +- simple attribute value range specification. + +The format of an attribute expression type c specification is as follows: + +| | | +|---------------------------------|--------------------------------------------------------------| +| <b><attribute-expr-c></b> | <b>::= <case-attribute> <simple-attribute></b> | +|---------------------------------|--------------------------------------------------------------| + +##### F.3.3.3.1 Case attribute value range specifications + +This form is used when the attribute specification within a constraint definition depends upon the value of another attribute (or parameter) in the same or another constraint definition. + +This specification begins with the terminal symbol CASE. The specification then consists of the field <reference-type> which may be either a functional reference or a direct reference. The terminal symbol SUPERIOR is used to specify the first superior constituent constraint containing the attribute. The <attribute-reference> non-terminal is a reference to an attribute (or parameter) in the same or another constituent definition. + +The attribute or parameter reference and terminal symbol OF, is followed by a list of case specifications. Each case specification consists of an attribute (or parameter) value pertaining to the attribute indicated in the field <attribute-reference> and an associated attribute specification which corresponds to that value. The terminal symbol VOID is used to specify the case where the attribute is not present. Each attribute value specification is in the format defined in F.3.3.3. + +The format is as follows: + +``` + +<case-attribute> ::= 'CASE' <reference-type> 'OF' + '{' <single-case-attribute>... '}' + +<reference-type> ::= <functional-reference> | <direct-reference> + +<functional-reference> ::= <function> '(' <direct-reference> ')' + +<function> ::= 'SUPERIOR' + +<direct-reference> ::= <c-name> '(' <attribute-reference> ')' + +<attribute-reference> ::= <attribute-name> [ '#' <parameter-name> ]... + +<single-case-attribute> ::= <case-value> ':' <attribute-expr-a> + +<case-value> ::= <attribute-value-except> | 'VOID' + +``` + +EXAMPLE 3 (in recommended style) + +``` + +DEFINE (FDA, " 'formatted' ") + +DEFINE (FPDA " 'formatted-processable' ") + +DEFINE (FC "ASN.1 { 2 8 2 6 0 }") + +CASE Document-profile (Document-architecture-class) OF { + + { $FDA }: + REQ Presentation-attributes { + REQ #content-architecture-class { $FC } + } + + { $FPDA }: + REQ Presentation-attributes { + REQ #content-architecture-class { ANY_VALUE } + } +} + +``` + +In this example, the value of the parameter “content architecture class” for the attribute “Presentation attributes” depends on the document architecture class to which the document belongs. + +##### F.3.3.3.2 Simple attribute value range specifications + +A simple attribute value range specification begins with one of the following keywords: + +**REQ** (required) – This means that the attribute shall always be specified for the constituent, i.e. the attribute is mandatory. + +**PERM** (permitted) – This means that a defaultable or non-mandatory attribute may but need not be specified for the constituent. If the attribute is defaultable, then the attribute shall have a value within the specified value range, either explicitly specified for the constituent or derived using the defaulting rules specified in ITU-T Rec. T.412 | ISO/IEC 8613-2. If the attribute is non-mandatory, then the constraint on the value is applicable only if the attribute is specified for the constituent. + +**DIS** (disallowed) – This means that a defaultable attribute shall not be specified for the associated constituent. The value of the attribute derived using the defaulting rules specified in ITU-T Rec. T.412 | ISO/IEC 8613-2 shall be within the specified value range. + +If an attribute is not explicitly specified and the attribute is defaultable, then the attribute value is derived using the defaulting rules specified in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +The keyword REQ, PERM or DIS is followed by the attribute name and the attribute specification. The keyword EXCEPT maybe inserted between attribute value specifications to restrict a range of values. Each attribute value specification may consist of a parameter expression, a keyword such as ANY\_VALUE, content information or an attribute value expression optionally preceded by the keyword NOVR. The keyword NOVR indicates that the attribute derived from an object class shall not be overridden in the corresponding object. An attribute value specification may also be empty to allow for the empty parameter list. + +The format of the simple attribute specification is as follows: + +| | | +|---------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b><simple-attribute></b> | <b>::= { 'REQ' 'PERM' 'DIS' } <attribute-name><br/><attribute-value-except></b> | +| <b><attribute-name></b> | <i>-- a name that identifies an attribute from the ITU-T Rec. T.410-Series ISO/IEC 8613, see also Table F.1 in F.3.6 --</i> | +| <b><attribute-value-except></b> | <b>::= '{' <attribute-value> '}'<br/>[ 'EXCEPT' '{' <attribute-value> '}' ]</b> | +| <b><attribute-value></b> | <b>::= -- empty --<br/> <parameter-expr-a><br/> <keyword><br/> <content-information><br/> [ 'NOVR' ] <attribute-value-expr></b> | + +Attribute names consist of a sequence of one or more characters. The first character shall be an uppercase letter ('A'..'Z'). All the other characters shall be lowercase letters ('a'..'z'), digits ('0'..'9') or hyphens ('-'). + +These names are as specified in the ITU-T Rec. T.410-Series | ISO/IEC 8613 with the exception that where the attribute name consists of more than one word, the spaces between the words are replaced by hyphens. F.3.6 (Table F.1) lists all the attribute names and their associated data types. + +#### F.3.3.4 Parameter expression specifications + +A parameter (or sub-parameter) expression specification allows choices between groups of parameters and allows repetition of groups of parameters. The comma symbol “,” is used to separate parameters and the vertical bar symbol “|” is used to separate groups of parameters. The keywords MUL and PMUL are used to indicate repetition and optional repetition of a group of parameters. This is necessary for some applications of the definition of the attribute “Bindings” in document application profiles and other cases which allow sets of parameters. Each parameter name in a parameter expression shall be preceded by either the REQ, PERM or DIS keyword. + +REQ (required) – This means that the parameter shall always be specified for the constituent, i.e. the parameter is mandatory. + +PERM (permitted) – This means that a defaultable or non-mandatory parameter may but need not be specified for an attribute. If the parameter is defaultable, then the parameter shall have a value within the specified value range, either explicitly specified for the parameter or derived using the defaulting rules specified in ITU-T Rec. T.412 | ISO/IEC 8613-2. If the parameter is non-mandatory, then the constraint on the value is applicable only if the parameter is specified for the attribute. + +DIS (disallowed) – This means that a defaultable parameter shall not be specified for the associated attribute. The value of the parameter derived using the defaulting rules specified in ITU-T Rec. T.412 | ISO/IEC 8613-2 shall be within the specified value range. + +The format of the parameter expression specification is as follows: + +| | | +|---------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b><parameter-expr-a></b> | <b>::= <parameter-expr-b> [ ' ' <parameter-expr-b> ]...</b> | +| <b><parameter-expr-b></b> | <b>::= <parameter-expr-c><br/> <parameter-expr-c> <parameter-expr-c>...<br/> <parameter-expr-c> { ',' <parameter-expr-c> }...</b> | +| <b><parameter-expr-c></b> | <b>::= <case-parameter><br/><simple-parameter><br/> 'REQ' '{' <parameter-expr-a> '}'<br/> 'PERM' '{' <parameter-expr-a> '}'<br/> 'MUL' '{' <parameter-expr-a> '}'<br/> 'PMUL' '{' <parameter-expr-a> '}'</b> | + +A parameter expression type c may be a case parameter or a simple parameter for single parameter specifications. The case form of specification is used when the parameter specification depends on the value of another attribute (or parameter) in the same or another constraint definition. (See F.3.3.3.1 for a description of the case mechanism.) + +##### F.3.3.4.1 Case parameter value range specifications + +The format of the case parameter specification is as follows: + +| | | +|--------------------------------------|----------------------------------------------------------------------------------------| +| <b><case-parameter></b> | <b>::= 'CASE' <reference-type> 'OF' '{' <single-case-parameter> '}'...</b> | +| <b><single-case-parameter></b> | <b>::= <case-value> ':' <attribute-value-except></b> | + +##### F.3.3.4.2 Simple parameter value range specifications + +In the case of a simple parameter value specification the format is as follows: + +**<simple-parameter>** ::= { 'REQ' | 'PERM' | 'DIS' } '#' <parameter-name> +<attribute-value-except> + +**<parameter-name>** -- *a name that identifies a (sub-)parameter from the ITU-T Rec. T.410-Series | ISO/IEC 8613, see F.3.6 (Table F.1) --* + +(Sub-)parameter names consist of a sequence of one or more characters. The first character shall be a lowercase letter ('a'..'z'). All the other characters shall be lowercase letters ('a'..'z'), digits ('0'..'9') or hyphens ('-'). + +These names are as specified in the ITU-T Rec. T.410-Series | ISO/IEC 8613 with the exception that where the parameter name consists of more than one word, the spaces between the words are replaced by hyphens. F.3.6 (Table F.1) lists all the parameter names and their associated data types. + +EXAMPLE 4 (in recommended style) + +``` +REQ Object-type { 'composite-logical-object' }, +REQ Position { + REQ #fixed-position { + REQ #horizontal-position { ANY_INTEGER }, + REQ #vertical-position { ANY_INTEGER } + } +} +``` + +#### F.3.3.5 Keywords + +The keywords allowed for an attribute or parameter value are ANY\_VALUE and VIRTUAL. ANY\_VALUE denotes that the attribute or parameter may take any value permitted for it in the ITU-T Rec. T.410-Series | ISO/IEC 8613. VIRTUAL is used in factor constraints to denote that the attribute or parameter value will be determined in a constraint definition that references that factor constraint. + +The format of the keyword constraint is as follows: + +**<keyword>** ::= 'ANY\_VALUE' | 'VIRTUAL' + +EXAMPLE 5 (in recommended style) + +**PERM Dimensions** { ANY\_VALUE } + +#### F.3.3.6 Content information constraint + +A content information constraint is used to define the allowed values for the attribute "Content information". This type of constraint has two parts for content information structured in accordance with the character content architecture and a single terminal symbol for raster and geometric content information. + +The format of the content information constraint is as follows: + +**<content-information>** ::= 'CHARACTER' [ '{' <control-function-list> '}' '...' ] +| 'RASTER' +| 'GEOMETRIC' + +**<control-function-list>** ::= <control-function> [ '|' <control-function> ]... + +**<control-function>** ::= '#' <control-function-name> [ '{' <attribute-value> '}' ] + +**<control-function-name>** -- *any abbreviated control function name specified in ITU-T Rec. T.416 | ISO/IEC 8613-6, see F.3.7 (Table F.2) --* + +EXAMPLE 6 (in recommended style) + +``` +DEFINE (CONTRLFNS," + { #CR + | #SGR { [ 'cancel' | 'increased-intensity' | 'normal-intensity' ]... } + | #SLS { ANY_INTEGER } + }...") +``` + +**PERM Content-information** { CHARACTER \$CONTRLFNS }, + +#### F.3.3.7 Attribute value expression specifications and production rules + +An attribute value expression defines the allowed range of values (that is both basic and non-basic values) that may be specified for that particular attribute. + +NOTE – The document profile constraint specification defines the non-basic attribute values allowed and also defines the default values to be used for those attributes for which a non-standard default value is specified. + +The attribute value expression specification allows one or more value types to be specified by means of sequences, choices, sets and repetitions of value expressions. Elements of a sequence construction are separated by a space. Elements of a set construction are separated by a comma. Elements of a choice construction are separated by a vertical bar, i.e. “|”. Elements that are repeated are suffixed with an ellipsis, i.e. “...”. Elements enclosed in square brackets, i.e. “[” and “]” are optional. Elements are grouped using curly brackets, i.e. “{” and “}”. In the cases where an attribute value type allows the specification of a set of production rules to define the allowed values, each production rule in the set shall be terminated by a semicolon “;”. The value type specification consists of one of fourteen different types of constraint as defined below. + +The format of the attribute expression specification is as follows: + +| | | +|-------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b><attribute-value-expr></b> | <b>::= <production-rule>...<br/><value-expr-a></b> | +| <b><production-rule></b> | <b>::= non-terminal-symbol> '::=' <value-expr-a> ','</b> | +| <b><non-terminal-symbol></b> | <i>-- A document application profile non-terminal symbol. It consists of a sequence of one or more characters enclosed in angle brackets ('<' and '>'). The first character shall be a lowercase letter ('a'..'z'). The remaining characters shall be lowercase letters ('a'..'z'), digits ('0'..'9') or hyphens ('-'). Within a given set of production rules, each non-terminal symbol referenced shall be defined once and only once and each non-terminal symbol defined shall be referenced at least once. --</i> | +| <b><value-expr-a></b> | <b>::= <value-expr-b> [' ' <value-expr-b> ]...</b> | +| <b><value-expr-b></b> | <b>::= <value-expr-c><br/> <value-expr-c> <value-expr-c>...<br/> <value-expr-c> { ',' <value-expr-c> }...</b> | +| <b><value-expr-c></b> | <b>::= '{' <value-expr-a> '}' [ '...' ]<br/> '[' <value-expr-a> ']' [ '...' ]<br/> <value-type> [ '...' ]</b> | +| <b><value-type></b> | <b>::= <non-terminal-symbol><br/> <enumerated-type><br/> <integer-value><br/> <real-value><br/> <character-string><br/> <escape-sequence><br/> <asn.1-object-id><br/> <reference-to-object-id><br/> <reference-to-object-class-id><br/> <reference-to-style-id><br/> <reference-to-subordinates><br/> <reference-to-content-portions><br/> <expr-function><br/> <invocation-control-function></b> | + +##### F.3.3.7.1 Enumerated data type constraint + +The enumerated data type constraint is used when an attribute or parameter consists of an enumerated data type as defined in the ITU-T Rec. T.410-Series | ISO/IEC 8613. The specification consists of an enumerated data type value. + +The format of the enumerated data type constraint is as follows: + +| | | +|--------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------| +| <b><enumerated-type></b> | <i>-- any enumerated data value specified in the ITU-T Rec. T.410-Series ISO/IEC 8613, enclosed in single quotes, see F.3.6 (Table F.1) --</i> | +|--------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------| + +EXAMPLE 7 (in recommended style) + +``` +REQ Layout-path { 'd0' + | 'd90' + | 'd270' + } +``` + +##### F.3.3.7.2 Integer value constraint + +An integer value constraint may be one of four different types of specification. These are: an integer, a relational specification, the specification of an inclusive range between two integers, and the keyword ANY\_INTEGER. ANY\_INTEGER is used to specify any integer value allowed by the ITU-T Rec. T.410-Series | ISO/IEC 8613. + +The format of the integer value constraint is as follows: + +``` + +<integer-value> ::= <integer> + | <relational-operator> <integer> + | <integer> '..' <integer> + | 'ANY_INTEGER' +<integer> ::= any integer constant -- +<relational-operator> ::= '>' | '<' | '>=' | '<=' + +``` + +Note – The relational operator “<>” may be implemented using the ‘EXCEPT’ mechanism (see F.3.3.3.2). + +EXAMPLE 8 (in recommended style) + +``` + +PERM Dimensions { + PERM #horizontal-dimension { + PERM #fixed-dimension { <= 9240 } + } + PERM #vertical-dimension { + PERM #fixed-dimension { 20..12400 } + } +} + +``` + +##### F.3.3.7.3 Real value constraint + +The real value constraint is used when an attribute or parameter consists of a real number specification. + +The format of the real value constraint is as follows: + +``` + +<real-value> ::= <real> +<real> ::= -- any real number -- + +``` + +EXAMPLE 9 (in recommended style) + +``` + +PERM #colour-specification { + PERM #cmyk-colour { + PERM #c-value { 0.1200..0.3200 } + PERM #m-value { 0.3800..0.4700 } + PERM #y-value { 0.5100..0.6800 } + PERM #k-value { 0.700..0.8100 } + } +} + +``` + +##### F.3.3.7.4 Character string constraint + +A character string constraint is used to define the allowed character strings for an attribute or parameter. ‘ANY\_STRING’ is used to specify any string allowed by the ITU-T Rec. T.410-Series | ISO/IEC 8613 consistent with the document application profile. + +The format of the character string constraint is as follows: + +``` + +<character-string> ::= <printable-string> + | '\ <octet>...' + | 'ANY_STRING' +<printable-string> ::= -- any string of printable characters enclosed in double quotes. A double quote in the + string is announced by another double quote -- +<octet> ::= <integer> '/' <integer> + -- where each integer is in the range 00..15 -- + +``` + +##### F.3.3.7.5 Escape sequence constraint + +This form of constraint is used when an attribute or parameter value consists of an escape sequence used for control purposes. Escape sequences are described in terms of the ESC terminal symbol followed by one or more characters defined by row and column positions in a character code table and optionally followed by a single invocation control function. + +The format of the escape sequence constraint is as follows: + +``` +<escape-sequence> ::= 'ESC' <octet>... [ <invocation-control-function> ] +<invocation-control-function> ::= { 'SI' | 'SO' | 'LS0' | 'LS1' | 'LS1R' | 'LS2' | 'LS2R' | 'LS3' | 'LS3R' | + 'SS2' | 'SS3' } +``` + +EXAMPLE 10 (in recommended style) + +-- Non-basic document characteristics -- + +``` +PERM Presentation-features { + PERM #character-presentation-features { + PERM #graphic-character-sets { ESC 02/15 04/06, ESC 07/12 } + -- Greek in G3 (Designation and Invocation) -- + } +} +``` + +##### F.3.3.7.6 ASN.1 object identifier constraint + +An ASN.1 object identifier constraint is used to define the allowed ASN.1 object identifiers for an attribute or parameter. This type of constraint allows a sequence of integers separated by spaces, as the possible attribute or parameter value. + +The format of the ASN.1 object identifier is as follows: + +``` +<asn.1-object-id> ::= 'ASN.1' '{' <integer>...'}' +``` + +EXAMPLE 11 (in recommended style) + +``` +DEFINE (FC, "ASN.1 { 2 8 2 6 0 }") +DEFINE (PC, "ASN.1 { 2 8 2 6 1 }") +DEFINE (FPC, "ASN.1 { 2 8 2 6 2 }") +``` + +``` +REQ Content-architecture-class { $FC | $PC | $FPC } +``` + +##### F.3.3.7.7 References to objects, object classes, styles, subordinates and content portions + +The references to objects, object classes, styles, subordinates, and content portions are used when an attribute or parameter consists of an identifier of an object, object class, layout or presentation style or the sequence of numeric strings that implicitly identify subordinates or content portions. The constraint specification consists of a keyword followed by a document application profile constituent name corresponding to one of the possible constituent constraints. + +The format of the reference to objects, object classes, content portions, and styles constraint is as follows: + +``` +<reference-to-object-id> ::= 'OBJECT_ID_OF' '(' <c-name> ')' +<reference-to-object-class-id> ::= 'OBJECT_CLASS_ID_OF' '(' <c-name> ')' +<reference-to-style-id> ::= 'STYLE_ID_OF' '(' <c-name> ')' +<reference-to-subordinates> ::= 'SUB_ID_OF' '(' <c-name> ')' [ '+' ] +<reference-to-content-portions> ::= 'CONTENT_ID_OF' '(' <c-name> ')' [ '+' ] +``` + +EXAMPLE 12 (in recommended style) + +``` +REQ Object-class { OBJECT_CLASS_ID_OF (PageSet) }, +PERM Presentation-style { STYLE_ID_OF (PresStyle-1) }, +``` + +##### F.3.3.7.8 Expression functions + +This form of value type is used to specify the constraints for object identifier expressions, string expressions and construction expressions. + +The format of an expression function is as follows: + +| | | +|---------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b><expr-function></b> | <b>::= <expr-token-word-0></b><br><b> <expr-token-word-1a> <one-parameter-a></b><br><b> <expr-token-word-1b> <one-parameter-b></b><br><b> <expr-token-word-2a> <two-parameter-a></b><br><b> <expr-token-word-2b> <two-parameter-b></b> | +| <b><one-parameter-a></b> | <b>::= <value-type></b><br><b> '{' <value-expr-a> '}'</b> | +| <b><one-parameter-b></b> | <b>::= '(' <value-expr-a> ')'</b> | +| <b><two-parameter-a></b> | <b>::= '(' <class-or-type> ',' <object-reference> ')'</b> | +| <b><two-parameter-b></b> | <b>::= '(' <value-expr-a> ')' '(' <value-expr-a> ')'</b> | +| <b><class-or-type></b> | <b>::= <value-expr-c> <object-type></b> | +| <b><object-type></b> | <b>::= 'DLAR' 'DOCUMENT_LAYOUT_ROOT' 'PAGESET' 'PAGE' 'FRAME' </b><br><b>'BLOCK' 'DLOR' 'DOCUMENT_LOGICAL_ROOT' 'CLO' </b><br><b>'COMPOSITE_LOGICAL' 'BLO' 'BASIC_LOGICAL'</b> | +| <b><object-reference></b> | <b>::= <value-expr-c> '(' <value-expr-c> ')'</b> | + +The expression token words are those words used as terminal symbols in ITU-T Rec. T.412 | ISO/IEC 8613-2. The association of these words is as follows: + +| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +|---------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------|----------|-------------------|----------|---------------------------|--|----------------|----------|--------------------|----------|--------------|----------|-----------------|--------------|----------|--------------------|----------|--------------|----------|--------------------|------------------|----------|----------------------|----------|----------------|----------|----------------------|-----------------|----------|----------------------|----------|--------------|----------|------------------|---------------|----------|--------------------|----------|-------------------|----------|---------------------------|--------------|----------|-------------------|----------|--------------|----------|-------------------|------------------|----------|--------------------------|----------|------------------|----------|----------------------|----------------|----------|------------------------|--|--|--|--| +| <b><expr-token-word-0> ::=</b> | <b>{ 'CURR-OBJ' 'CURRENT-OBJECT' }</b> | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| <b><expr-token-word-1a> ::=</b> | <b>{ 'OPT' 'OPT REP' 'REP' }</b> | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| <b><expr-token-word-1b> ::=</b> | <table border="0" style="width: 100%;"> <tr> <td><b>{ 'AGG'</b></td><td><b> </b></td><td><b>'AGGREGATE'</b></td><td><b> </b></td><td><b>'CHO'</b></td><td><b> </b></td><td><b>'CHOICE'</b></td> </tr> <tr> <td><b>'DEC'</b></td><td><b> </b></td><td><b>'DECREMENT'</b></td><td><b> </b></td><td><b>'INC'</b></td><td><b> </b></td><td><b>'INCREMENT'</b></td> </tr> <tr> <td><b>'L-ALPHA'</b></td><td><b> </b></td><td><b>'LOWER-ALPHA'</b></td><td><b> </b></td><td><b>'L-ROM'</b></td><td><b> </b></td><td><b>'LOWER-ROMAN'</b></td> </tr> <tr> <td><b>'MK-STR'</b></td><td><b> </b></td><td><b>'MAKE-STRING'</b></td><td><b> </b></td><td><b>'ORD'</b></td><td><b> </b></td><td><b>'ORDINAL'</b></td> </tr> <tr> <td><b>'PREC'</b></td><td><b> </b></td><td><b>'PRECEDING'</b></td><td><b> </b></td><td><b>'PREC-OBJ'</b></td><td><b> </b></td><td><b>'PRECEDING-OBJECT'</b></td> </tr> <tr> <td><b>'SEQ'</b></td><td><b> </b></td><td><b>'SEQUENCE'</b></td><td><b> </b></td><td><b>'SUP'</b></td><td><b> </b></td><td><b>'SUPERIOR'</b></td> </tr> <tr> <td><b>'SUP-OBJ'</b></td><td><b> </b></td><td><b>'SUPERIOR-OBJECT'</b></td><td><b> </b></td><td><b>'U-ALPHA'</b></td><td><b> </b></td><td><b>'UPPER-ALPHA'</b></td> </tr> <tr> <td><b>'U-ROM'</b></td><td><b> </b></td><td><b>'UPPER-ROMAN' }</b></td><td></td><td></td><td></td><td></td> </tr> </table> | | | | | | | <b>{ 'AGG'</b> | <b> </b> | <b>'AGGREGATE'</b> | <b> </b> | <b>'CHO'</b> | <b> </b> | <b>'CHOICE'</b> | <b>'DEC'</b> | <b> </b> | <b>'DECREMENT'</b> | <b> </b> | <b>'INC'</b> | <b> </b> | <b>'INCREMENT'</b> | <b>'L-ALPHA'</b> | <b> </b> | <b>'LOWER-ALPHA'</b> | <b> </b> | <b>'L-ROM'</b> | <b> </b> | <b>'LOWER-ROMAN'</b> | <b>'MK-STR'</b> | <b> </b> | <b>'MAKE-STRING'</b> | <b> </b> | <b>'ORD'</b> | <b> </b> | <b>'ORDINAL'</b> | <b>'PREC'</b> | <b> </b> | <b>'PRECEDING'</b> | <b> </b> | <b>'PREC-OBJ'</b> | <b> </b> | <b>'PRECEDING-OBJECT'</b> | <b>'SEQ'</b> | <b> </b> | <b>'SEQUENCE'</b> | <b> </b> | <b>'SUP'</b> | <b> </b> | <b>'SUPERIOR'</b> | <b>'SUP-OBJ'</b> | <b> </b> | <b>'SUPERIOR-OBJECT'</b> | <b> </b> | <b>'U-ALPHA'</b> | <b> </b> | <b>'UPPER-ALPHA'</b> | <b>'U-ROM'</b> | <b> </b> | <b>'UPPER-ROMAN' }</b> | | | | | +| <b>{ 'AGG'</b> | <b> </b> | <b>'AGGREGATE'</b> | <b> </b> | <b>'CHO'</b> | <b> </b> | <b>'CHOICE'</b> | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| <b>'DEC'</b> | <b> </b> | <b>'DECREMENT'</b> | <b> </b> | <b>'INC'</b> | <b> </b> | <b>'INCREMENT'</b> | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| <b>'L-ALPHA'</b> | <b> </b> | <b>'LOWER-ALPHA'</b> | <b> </b> | <b>'L-ROM'</b> | <b> </b> | <b>'LOWER-ROMAN'</b> | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| <b>'MK-STR'</b> | <b> </b> | <b>'MAKE-STRING'</b> | <b> </b> | <b>'ORD'</b> | <b> </b> | <b>'ORDINAL'</b> | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| <b>'PREC'</b> | <b> </b> | <b>'PRECEDING'</b> | <b> </b> | <b>'PREC-OBJ'</b> | <b> </b> | <b>'PRECEDING-OBJECT'</b> | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| <b>'SEQ'</b> | <b> </b> | <b>'SEQUENCE'</b> | <b> </b> | <b>'SUP'</b> | <b> </b> | <b>'SUPERIOR'</b> | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| <b>'SUP-OBJ'</b> | <b> </b> | <b>'SUPERIOR-OBJECT'</b> | <b> </b> | <b>'U-ALPHA'</b> | <b> </b> | <b>'UPPER-ALPHA'</b> | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| <b>'U-ROM'</b> | <b> </b> | <b>'UPPER-ROMAN' }</b> | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| <b><expr-token-word-2a> ::=</b> | <b>{ 'CURR-INST' 'CURRENT-INSTANCE' }</b> | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| <b><expr-token-word-2b> ::=</b> | <b>{ 'B_REF' 'BINDING_REFERENCE' }</b> | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | + +###### F.3.3.7.8.1 Object identifier expression constraint + +An object identifier expression constraint is an expression function used to define the allowed object identifier expressions for an attribute or parameter. This type of constraint is specified by means of a set of production rules using the meta symbols defined in F.3.2.1. The exception to this rule is that the apostrophe symbols "'" and "'" used to delimit terminals in the Document application profile proforma are not used in a document application profile specification. + +The following restrictions also apply : + +- a) The start symbol shall be the non-terminal <object-id-expr>. +- b) The terminal symbols are restricted to those defined in ITU-T Rec. T.412 | ISO/IEC 8613-2 together with 'OBJECT\_CLASS\_ID\_OF', 'OBJECT\_ID\_OF', '(', ')' and any document application profile constituent name. +- c) The set of production rules shall be defined such that they always generate an object identifier expression which is in accordance with the rules defined in ITU-T Rec. T.412 | ISO/IEC 8613-2 and each production rule in the set shall be terminated by a semicolon ";". + +EXAMPLE 13 (in recommended style) + +``` + +PERM Same-layout-object { + PERM #to-logical-object { + <object-id-expr> ::= PREC-OBJ (CURR-OBJ); + }, + PERM #to-layout-object { 'page' } + } + +``` + +###### F.3.3.7.8.2 String expression constraint + +A string expression constraint is an expression function used to define the allowed string expressions for an attribute or parameter. This type of constraint is specified by means of a set of production rules using the meta symbols defined in F.3.2.1. The exception to this rule is that the apostrophe symbols “'” and “'” used to delimit terminals in the Document application profile proforma are not used in a document application profile specification. + +The following restrictions also apply: + +- The start symbol shall be the non-terminal <string-expr>. +- The terminal symbols are restricted to those defined in ITU-T Rec. T.412 | ISO/IEC 8613-2 together with ‘OBJECT\_CLASS\_ID\_OF’, ‘OBJECT\_ID\_OF’, ‘(’, ‘)’, ‘ANY\_STRING’, ‘ANY\_INTEGER’, any document application profile constituent name and any Document application profile defined character string enclosed in quotation marks, i.e. “...”. +- The set of production rules shall be defined such that they always generate a string expression which is in accordance with the rules defined in ITU-T Rec. T.412 | ISO/IEC 8613-2 and each production rule in the set shall be terminated by a semicolon “;”. +- The production rule for integer value constraint in F.3.3.7.2 is used in place of the non-terminal <numeric literal> production rule in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +EXAMPLE 14 (in recommended style) + +**DEFINE (PAGENUMBERSTRING, "** + +``` + +<string-expr> ::= [ ANY_STRING ] + INC (B_REF (PREC (CURR-OBJ)) ("PGnum" )) + [ ANY_STRING ]; " + +``` + +**PERM Content-generator**            **{ \$PAGENUMBERSTRING },** + +###### F.3.3.7.8.3 Construction expression constraint + +A construction expression constraint is an expression function used to define the allowed values for the attribute “Generator for subordinates”. This type of constraint is specified by means of a set of production rules using the meta symbols defined in F.3.2.1. The exception to this rule is that the apostrophe symbols “'” and “'” used to delimit terminals in the Document application profile proforma are not used in a document application profile specification. + +The following restrictions also apply : + +- The start symbol shall be the non-terminal <construction-expr>. +- The terminal symbols are restricted to those defined in ITU-T Rec. T.412 | ISO/IEC 8613-2 together with ‘OBJECT\_CLASS\_ID\_OF’ and any document application profile constituent name. +- The set of production rules shall be defined such that they always generate a construction expression which is in accordance with the rules defined in ITU-T Rec. T.412 | ISO/IEC 8613-2 and each production rule in the set shall be terminated by a semicolon “;”. + +EXAMPLE 15 (in recommended style) + +**DEFINE (POSS-A, "** + +``` + +<construction-expr> ::= <object-class> + | CHO (<object-class>...) + | OPT <object-class>; + +<object-class> ::= OBJECT_CLASS_ID_OF (A) ; " + +``` + +**REQ Generator-for-subordinates**            **{ \$POSS-A }** + +EXAMPLE 16 (in recommended style) + +DEFINE (ITERANY--A-B-C, " + +``` + + <construction-expr> ::= <construction-term> + | <construction-type> ; + + <construction-term> ::= <construction-factor> + | OPT <construction-factor> + | REP <construction-factor> + | OPT REP <construction-factor>; + + <construction-type> ::= SEQ (<construction-term>...) + | AGG (<construction-term>...) + | CHO (<construction-term>...); + + <construction-factor> ::= OBJECT_CLASS_ID_OF (A) + | OBJECT_CLASS_ID_OF (B) + | OBJECT_CLASS_ID_OF (C) + | <construction-type> ; " +``` + +REQ Generator-for-subordinates { \$ITERANY--A-B-C }, + +##### F.3.3.7.9 Invocation control function constraint + +This form of value type constraint is used when an attribute or parameter value consists of an invocation sequence. Invocation control function constraint specification consists of a list of possible invocation control functions allowed by the ITU-T Rec. T.410-Series | ISO/IEC 8613. The format of the invocation control function constraint is as follows: + +``` + +<invocation-control-function> ::= { 'S0', 'LS0', 'S1', 'LS1', 'LS1R', 'LS2', 'LS2R', 'LS3', 'LS3R', 'SS2', 'SS3' } +``` + +EXAMPLE 17 (in recommended style) + +``` + +PERM Presentation-attributes { + PERM #character-attributes { + PERM #graphic-character-sets { S1 } +} +} +``` + +### F.3.4 Summary of production rules + +``` + +<document-application-profile> ::= { <macro-definition> | <constraint-definition> }... + +<macro-definition> ::= 'DEFINE' '(' <macro-name> ',' <macro-string> ')' + +<macro-name> -- A unique name that identifies a document application profile macro name. It + consists of a sequence of one or more characters. The first character shall be a + letter ('a'..'z', 'A'..'Z'). The remaining characters shall be the letters ('a'..'z', 'A'..'Z'), + digits ('0'..'9') or hyphens ('-'). Uppercase and lowercase letters are not significant + but their use throughout a document application profile should be consistent. -- + +<macro-string> ::= <printable-string> + +<constraint-definition> ::= <constraint-name> '{' <constraint> '}' + +<constraint-name> ::= <constituent-name> | <factor-name> + +<constituent-name> ::= <c-name> [ <factor-reference> ] + +<c-name> -- A unique name that identifies a document application profile constituent constraint. + It consists of a sequence of one or more characters. The first character shall be + an uppercase letter ('A'..'Z'). The remaining characters shall be uppercase letters + ('A'..'Z'), digits ('0'..'9') or hyphens ('-'). -- + +<factor-reference> ::= ':' <f-name> + +<factor-name> ::= 'FACTOR' <f-name> [ <factor-reference> ] +``` + +| | | +|--------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <f-name> | -- A unique name that identifies a document application profile factored constraint. It consists of a sequence of one or more characters. The first character shall be an uppercase letter ('A'..'Z'). The remaining characters shall be uppercase letters ('A'..'Z'), digits ('0'..'9') or hyphens ('-'). -- | +| <constraint> | ::= <section>... <attribute-expr-a> | +| <section> | ::= { 'GENERIC' 'SPECIFIC' 'SPECIFIC_AND_GENERIC' } ':' <attribute-expr-a> | +| <attribute-expr-a> | ::= <attribute-expr-b> [ ' ' <attribute-expr-b> ]... | +| <attribute-expr-b> | ::= <attribute-expr-c> [ ',' <attribute-expr-c> ]... | +| <attribute-expr-c> | ::= <case-attribute> <simple-attribute> | +| <case-attribute> | ::= 'CASE' <reference-type> 'OF' '{' <single-case-attribute>... '}' | +| <reference-type> | ::= <functional-reference> <direct-reference> | +| <functional-reference> | ::= <function> '(' <direct-reference> ')' | +| <function> | ::= 'SUPERIOR' | +| <direct-reference> | ::= <c-name> '(' <attribute-reference> ')' | +| <attribute-reference> | ::= <attribute-name> [ '#' <parameter-name> ]... | +| <single-case-attribute> | ::= <case-value> ':' <attribute-expr-a> | +| <case-value> | ::= <attribute-value-except> 'VOID' | +| <simple-attribute> | ::= { 'REQ' 'PERM' 'DIS' } <attribute-name><br><attribute-value-except> | +| <attribute-name> | -- a name that identifies an attribute from the ITU-T Rec. T.410-Series ISO/IEC 8613, see F.3.6 (Table F.1) -- | +| <attribute-value-except> | ::= '{' <attribute-value> '}'<br>[ 'EXCEPT' '{' <attribute-value> '}' ] | +| <attribute-value> | ::= -- empty --<br> <parameter-expr-a><br> <keyword><br> <content-information><br> [ 'NOVR' ] <attribute-value-expr> | +| <parameter-expr-a> | ::= <parameter-expr-b> [ ' ' <parameter-expr-b> ]... | +| <parameter-expr-b> | ::= <parameter-expr-c><br> <parameter-expr-c> <parameter-expr-c>...<br> <parameter-expr-c> { ',' <parameter-expr-c> }... | +| <parameter-expr-c> | ::= <case-parameter><br> <simple-parameter><br> 'REQ' '{' <parameter-expr-a> '}'<br> 'PERM' '{' <parameter-expr-a> '}'<br> 'MUL' '{' <parameter-expr-a> '}'<br> 'PMUL' '{' <parameter-expr-a> '}' | +| <case-parameter> | ::= 'CASE' <reference-type> 'OF' '{' <single-case-parameter>... '}' | +| <single-case-parameter> | ::= <case-value> ':' <attribute-value-except> | +| <simple-parameter> | ::= { 'REQ' 'PERM' 'DIS' } '#' <parameter-name><br><attribute-value-except> | +| <parameter-name> | -- a name that identifies a (sub-)parameter from the ITU-T Rec. T.410-Series ISO/IEC 8613, see F.3.6 (Table F.1) -- | +| <keyword> | ::= 'ANY_VALUE' 'VIRTUAL' | +| <content-information> | ::= 'CHARACTER' [ '{' <control-function-list> '}' '...' ]<br> 'RASTER'<br> 'GEOMETRIC' | + +| | | +|-------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <control-function-list> | ::= <control-function> [ ' ' <control-function> ]... | +| <control-function> | ::= '#' <control-function-name> [ '{' <attribute-value> '}' ] | +| <control-function-name> | -- any abbreviated control function name specified in ITU-T Rec. T.416 <br>ISO/IEC 8613-6, see 7.3.7 (Table F.2) -- | +| <attribute-value-expr> | ::= <production-rule>...<br> <value-expr-a> | +| <production-rule> | ::= <non-terminal-symbol> '::=' <value-expr-a> ';' | +| <non-terminal-symbol> | -- A document application profile non-terminal symbol. It consists of a sequence of<br>one or more characters enclosed in angle brackets ('<' and '>'). The first character<br>shall be a lowercase letter ('a'..'z'). The remaining characters shall be lowercase<br>letters ('a'..'z'), digits ('0'..'9') or hyphens ('-'). Within a given set of production rules,<br>each non-terminal symbol referenced shall be defined once and only once and<br>each non-terminal symbol defined shall be referenced at least once. -- | +| <value-expr-a> | ::= <value-expr-b> [ ' ' <value-expr-b> ]... | +| <value-expr-b> | ::= <value-expr-c><br> <value-expr-c> <value-expr-c>...<br> <value-expr-c> { ',' <value-expr-c> }... | +| <value-expr-c> | ::= '{' <value-expr-a> '}' [ '...' ]<br> '[' <value-expr-a> ']' [ '...' ]<br> <value-type> [ '...' ] | +| <value-type> | ::= <non-terminal-symbol><br> <enumerated-type><br> <integer-value><br> <real-value><br> <character-string><br> <escape-sequence><br> <asn.1-object-id><br> <reference-to-object-id><br> <reference-to-object-class-id><br> <reference-to-style-id><br> <reference-to-subordinates><br> <reference-to-content-portions><br> <expr-function><br> <invocation-control-function> | +| <enumerated-type> | -- any enumerated data value specified in the ITU-T Rec. T.410-Series<br>ISO/IEC 8613 enclosed in single quotes, see F.3.6 (Table F.1) -- | +| <integer-value> | ::= <integer><br> <relational-operator> <integer><br> <integer> '..' <integer><br> 'ANY_INTEGER' | +| <integer> | -- any integer constant -- | +| <relational-operator> | ::= '>' '<' '>=' '<=' | +| <real-value> | ::= <real> | +| <real> | -- any real constant -- | +| <character-string> | ::= <printable-string><br> '\<octet>...' '\'<br> 'ANY_STRING' | +| <printable-string> | -- any string of printable characters enclosed in double quotes. A double quote in the<br>string is announced by another double quote -- | +| <octet> | ::= <integer> '/' <integer><br><br>-- where each integer is in the range 00..15 -- | + +| | | +|---------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <escape-sequence> | ::= [ 'ESC' <octet>... <invocation-control-function> ] | +| <invocation-control-function> | ::= { 'SI' 'SO' 'LS0' 'LS1' 'LS1R' 'LS2' 'LS2R' 'LS3' 'LS3R' 'SS2' 'SS3' } | +| <asn.1-object-id> | ::= 'ASN.1' '{' <integer>... '}' | +| <reference-to-object-id> | ::= 'OBJECT_ID_OF' '(' <c-name> ')' | +| <reference-to-object-class-id> | ::= 'OBJECT_CLASS_ID_OF' '(' <c-name> ')' | +| <reference-to-style-id> | ::= 'STYLE_ID_OF' '(' <c-name> ')' | +| <reference-to-subordinates> | ::= 'SUB_ID_OF' '(' <c-name> ')' [ '+' ] | +| <reference-to-content-portions> | ::= 'CONTENT_ID_OF' '(' <c-name> ')' [ '+' ] | +| <expr-function> | ::= <expr-token-word-0><br> <expr-token-word-1a> <one-parameter-a><br> <expr-token-word-1b> <one-parameter-b><br> <expr-token-word-2a> <two-parameter-a><br> <expr-token-word-2b> <two-parameter-b> | +| <one-parameter-a> | ::= <value-type><br> '{' <value-expr-a> '}' | +| <one-parameter-b> | ::= '(' <value-expr-a> ')' | +| <two-parameter-a> | ::= '(' <class-or-type> ',' <object-reference> ')' | +| <two-parameter-b> | ::= '(' <value-expr-a> ')' '(' <value-expr-a> ')' | +| <class-or-type> | ::= <value-expr-c> <object-type> | +| <object-type> | ::= 'DLAR' 'DOCUMENT_LAYOUT_ROOT' 'PAGESET' 'PAGE' 'FRAME' <br>'BLOCK' 'DLOR' 'DOCUMENT_LOGICAL_ROOT' 'CLO' <br>'COMPOSITE_LOGICAL' 'BLO' 'BASIC_LOGICAL' | +| <object-reference> | ::= <value-expr-c> '(' <value-expr-c> ')' | + +The expression token words are those words used as terminal symbols in ITU-T Rec. T.412 | ISO/IEC 8613-2. The association of these words is as follows: + +| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +|--------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------|--|-------------|--|--------------------|--|----------|-------|--|-------------|--|-------|--|-------------|-----------|--|---------------|--|---------|--|---------------|----------|--|---------------|--|-------|--|-----------|--------|--|-------------|--|------------|--|--------------------|-------|--|------------|--|-------|--|------------|-----------|--|-------------------|--|-----------|--|---------------|---------|--|-----------------|--|--|--|--| +| <expr-token-word-0> ::= | { 'CURR-OBJ' 'CURRENT-OBJECT' } | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| <expr-token-word-1a> ::= | { 'OPT' 'OPT REP' 'REP' } | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| <expr-token-word-1b> ::= | <table border="0"> <tr> <td>{ 'AGG'</td> <td> </td> <td>'AGGREGATE'</td> <td> </td> <td>'CHO'</td> <td> </td> <td>'CHOICE'</td> </tr> <tr> <td>'DEC'</td> <td> </td> <td>'DECREMENT'</td> <td> </td> <td>'INC'</td> <td> </td> <td>'INCREMENT'</td> </tr> <tr> <td>'L-ALPHA'</td> <td> </td> <td>'LOWER-ALPHA'</td> <td> </td> <td>'L-ROM'</td> <td> </td> <td>'LOWER-ROMAN'</td> </tr> <tr> <td>'MK-STR'</td> <td> </td> <td>'MAKE-STRING'</td> <td> </td> <td>'ORD'</td> <td> </td> <td>'ORDINAL'</td> </tr> <tr> <td>'PREC'</td> <td> </td> <td>'PRECEDING'</td> <td> </td> <td>'PREC-OBJ'</td> <td> </td> <td>'PRECEDING-OBJECT'</td> </tr> <tr> <td>'SEQ'</td> <td> </td> <td>'SEQUENCE'</td> <td> </td> <td>'SUP'</td> <td> </td> <td>'SUPERIOR'</td> </tr> <tr> <td>'SUP-OBJ'</td> <td> </td> <td>'SUPERIOR-OBJECT'</td> <td> </td> <td>'U-ALPHA'</td> <td> </td> <td>'UPPER-ALPHA'</td> </tr> <tr> <td>'U-ROM'</td> <td> </td> <td>'UPPER-ROMAN' }</td> <td></td> <td></td> <td></td> <td></td> </tr> </table> | { 'AGG' | | 'AGGREGATE' | | 'CHO' | | 'CHOICE' | 'DEC' | | 'DECREMENT' | | 'INC' | | 'INCREMENT' | 'L-ALPHA' | | 'LOWER-ALPHA' | | 'L-ROM' | | 'LOWER-ROMAN' | 'MK-STR' | | 'MAKE-STRING' | | 'ORD' | | 'ORDINAL' | 'PREC' | | 'PRECEDING' | | 'PREC-OBJ' | | 'PRECEDING-OBJECT' | 'SEQ' | | 'SEQUENCE' | | 'SUP' | | 'SUPERIOR' | 'SUP-OBJ' | | 'SUPERIOR-OBJECT' | | 'U-ALPHA' | | 'UPPER-ALPHA' | 'U-ROM' | | 'UPPER-ROMAN' } | | | | | +| { 'AGG' | | 'AGGREGATE' | | 'CHO' | | 'CHOICE' | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| 'DEC' | | 'DECREMENT' | | 'INC' | | 'INCREMENT' | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| 'L-ALPHA' | | 'LOWER-ALPHA' | | 'L-ROM' | | 'LOWER-ROMAN' | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| 'MK-STR' | | 'MAKE-STRING' | | 'ORD' | | 'ORDINAL' | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| 'PREC' | | 'PRECEDING' | | 'PREC-OBJ' | | 'PRECEDING-OBJECT' | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| 'SEQ' | | 'SEQUENCE' | | 'SUP' | | 'SUPERIOR' | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| 'SUP-OBJ' | | 'SUPERIOR-OBJECT' | | 'U-ALPHA' | | 'UPPER-ALPHA' | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| 'U-ROM' | | 'UPPER-ROMAN' } | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| <expr-token-word-2a> ::= | { 'CURR-INST' 'CURRENT-INSTANCE' } | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +| <expr-token-word-2b> ::= | { 'B_REF' 'BINDING_REFERENCE' } | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | + +### F.3.5 Presentation of document application profile specification + +This annex does not define a presentation style for the document application profile specification. However, a consistent style of presentation should be adopted to aid readability. The following is an example of a style that may be used. + +#### Layout-Object-Block { + +#### SPECIFIC: + +``` + +REQ Object-type { 'block' }, +REQ Object-identifier { OBJECT_ID_OF (Block1) }, +REQ Content-portions { CONTENT_ID_OF + (Character-content-portion-1) + }, +PERM Presentation-style { STYLE_ID_OF (Pres-style-1) }, +PERM Content-architecture-class { ASN.1 { 2 8 2 6 0 } + | ASN.1 { 2 8 2 6 2 } + }, +PERM Presentation-attributes { + -- Character presentation attributes -- + PERM #alignment { 'start-aligned' | 'justified' }, + PERM #character-spacing { 100 | 200 }, + PERM #first-line-offset { ANY_INTEGER }, + PERM #graphic-rendition { [ 'cancel' + | 'increased-intensity' + | 'italicized' + | 'underlined' + | 'normal-intensity' + | 'not-italicized' + | 'not-underlined' + ]... + }, + PERM #itemization { ANY_VALUE }, + PERM #line-layout-table { + PMUL + PERM #tabulation-reference { ANY_VALUE }, + PERM #tabulation-position { ANY_INTEGER }, + PERM #alignment { 'start-aligned' + | 'aligned-around' + }, + PERM #alignment-string { ANY_STRING } + } +}, +PERM #line-spacing { 200 | 300 | 400 }, +PERM #initial-offset { + PERM #horizontal-coordinate { 200 } + PERM #vertical-coordinate { 200 } +} +}, +PERM User-readable-comments { ANY_STRING }, +PERM User-visible-name { "BLOCK" }, +REQ Position { + REQ #fixed-position { + REQ #horizontal-dimension { ANY_INTEGER } + REQ #vertical-dimension { ANY_INTEGER } + } +}, +REQ Dimensions { + REQ #horizontal-dimension { + REQ #fixed-dimension { ANY_INTEGER } + } + REQ #vertical-dimension { + REQ #fixed-dimension { ANY_INTEGER } + } +} +} + +``` + +### **F.3.6 Table F.1 ITU-T Rec. T.410-Series | ISO/IEC 8613 attribute/(sub-) parameter names and their associated DAPPN data types** + +The association between the ITU-T Rec. T.410-Series | ISO/IEC 8613 attribute/(sub-) parameter names and DAPPN data types is specified in Table F.1. In Table F.1: + +- each (sub-) parameter of an attribute is preceded by the hash symbol: “#”; +- comments are delimited by a pair of hyphen symbols: “--”; +- more than one occurrence of a name or data type is indicated using the ellipsis symbol: “...”. If an ellipsis appears after an attribute/(sub-) parameter name, it specifies that the attribute/(sub-) parameter and all previous attribute/(sub-) parameters that are part of that declaration description and which are at the same indentation level as the immediately preceding attribute/(sub-) parameter, may be repeated. If an ellipsis appears for a data type specification declaration, it specifies that only the immediately preceding data type in the data type specification may be repeated. When more than one data type in a data type specification may be repeated, the repeatable data types are grouped using parentheses, “(” and “)”, and the ellipsis immediately follows the closing parenthesis: “)”;; +- for <enumeration-type> data types the names of the enumerations follow the colon symbol: “:”; +- in the case of attributes or (sub-) parameters that have more than one data type the possible types are separated by the comma symbol: “,”; +- macros are also used as defined in F.3.3.1; +- the comment -- empty -- implies that the value of the attribute or parameter name has no corresponding value or, in the case of a control function, that the control function has no control function parameter value; +- the data type specifications do not include the <keyword> data type that is allowed for any attribute or parameter value specification; +- use of presentation attributes in the document profile shall be restricted to the specification of those non-basic attribute values which should be used in the document; +- the presentation attribute values specified in the attribute “Document-application-profile-defaults” for a particular document profile shall be used in place of the default values specified in this document for those same attributes, as needed, in order to process unambiguously the particular document instance associated with the document profile. + +### **F.3.7 Table F.2 ITU-T Rec. T.416 | ISO/IEC 8613-6 character content information control function names and their associated DAPPN data types** + +The association between ITU-T Rec. T.416 | ISO/IEC 8613-6 character content information control function names and DAPPN data types is specified in Table F.2. In Table F.2: + +- comments are delimited by a pair of hyphen symbols: “--” ; +- for <enumeration-type> data types the names of the enumerations follow the colon symbol: “:” ; +- the comment -- empty -- implies that the control function has no control function parameter value. + +Table F.1 – List of attributes and data types + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <pre> .. macro definitions .. DEFINE (case-i-dimensions-val," #horizontal-dimension #fixed-dimension #vertical-dimension #fixed-dimension ") DEFINE (min-max," #minimum #maximum ") DEFINE (case-ii-dimensions-val," #horizontal-dimension #fixed-dimension #rule-a #rule-b #maximum-size #vertical-dimension #fixed-dimension #rule-a #rule-b #maximum-size ") DEFINE (case-iii-dimensions-val," #horizontal-dimension #fixed-dimension #vertical-dimension #fixed-dimension #variable-page-height ") DEFINE (colour-exp," #colour-access-mode #direct-colour-expression #colour-space-id #colour-specification #cmyk-colour #c-value #m-value #y-value #k-value #rgb-colour #r-value #g-value #b-value #cie-colour #x-value #y-value #z-value #colour-tolerance #specified-tolerance #tolerance-value #tolerance-space #unspecified-tolerance #indexed-colour-expression #index ") DEFINE (colour-tbl," #colour-space-id #colour-table-entry #index #colour-coordinates #colour-tolerance #specified-tolerance #tolerance-value #tolerance-space #unspecified-tolerance ... ") </pre> | <pre> -- empty --, <integer-value> -- empty --, <integer-value> <integer-value> <integer-value> -- empty --, <integer-value> -- empty --, \$min-max -- empty --, \$min-max <enumeration-type>:'applies' -- empty --, <integer-value> -- empty --, \$min-max -- empty --, \$min-max <enumeration-type>:'applies' <enumeration-type>:'null', <integer-value> <enumeration-type>:'null', <integer-value> <integer-value> <enumeration-type>:'direct' 'indirect' <integer-value> <integer-value>... <integer-value>, <real-value> <integer-value>, <real-value> <integer-value>, <real-value> <integer-value>, <real-value> <integer-value>, <real-value> <integer-value>, <real-value> <integer-value>, <real-value> <integer-value>, <real-value> <integer-value>, <real-value> <integer-value>, <real-value> <integer-value> <enumeration-type>:'CIELUV' 'CIELAB' <enumeration-type>:'infinite' <integer-value> <integer value> <integer-value> <integer-value>... <integer-value> <enumeration-type>:'CIELUV' 'CIELAB' <enumeration-type>:'infinite' </pre> | + +Table F.1 – List of attributes and data types (*continued*) + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b>DEFINE (offset-val,"</b><br><b>#leading-offset</b><br><b>#trailing-offset</b><br><b>#left-hand-offset</b><br><b>#right-hand-offset</b><br><b>)</b><br><b>DEFINE (separation-val,"</b><br><b>#leading-edge</b><br><b>#trailing-edge</b><br><b>#centre-separation</b><br><b>)</b><br><b>DEFINE (edge,"</b><br><b>#line-width</b><br><b>#line-type</b><br><br><b>#free-space-width</b><br><b>#line-colour</b><br><b>#implementation-defined</b><br><b>#colour-expression</b><br><b>)</b><br><b>DEFINE (border-val,"</b><br><b>#left-hand-edge</b><br><b>#right-hand-edge</b><br><b>#trailing-edge</b><br><b>#leading-edge</b><br><b>)</b><br><b>DEFINE (medium-type-val,"</b><br><b>#nominal-page-size</b><br><b>#horizontal-dimension</b><br><b>#vertical-dimension</b><br><b>#side-of-sheet</b><br><b>#colour-of-medium</b><br><b>#unspecified-colour</b><br><b>#specified-colour</b><br><b>)</b><br><b>DEFINE (bundle-part-val,"</b><br><b>#bundle-index</b><br><b>#bundle-representation</b><br><b>...</b><br><b>)</b><br><b>DEFINE (name,"</b><br><b>#surname</b><br><b>#givenname</b><br><b>#initials</b><br><b>#generation-qualifier</b><br><b>)</b><br><b>DEFINE (method-info,"</b><br><b>#unique-method-info</b><br><b>#descriptive-method-info</b><br><b>)</b><br><b>DEFINE (key-info,"</b><br><b>#method-information</b><br><b>#additional-information</b><br><b>#descriptive-information</b><br><b>#octet-string</b><br><b>)</b><br><b>DEFINE (seal-data,"</b><br><b>#seal-method</b><br><b>#fingerprint-method</b><br><b>#fingerprint-key-information</b><br><b>#sealing-method</b><br><b>#sealing-key-information</b><br><b>#sealing-information</b><br><b>#fingerprint</b><br><b>#time</b><br><b>#seal-originator</b><br><b>#location</b><br><b>#unique-location</b><br><b>#descriptive-location</b><br><b>#seal</b><br><b>)</b> | <br><integer-value><br><integer-value><br><integer-value><br><integer-value><br><br><integer-value><br><integer-value><br><integer-value><br><br><integer-value><br><enumeration-type>:'invisible' 'solid' 'dashed' 'dot'<br>'dash-dot' 'dash-dot-dot'<br><integer-value><br><br>-- empty --, <character-string><br>-- empty --, \$colour-exp<br><br>-- empty --, \$edge<br>-- empty --, \$edge<br>-- empty --, \$edge<br>-- empty --, \$edge<br><br><integer-value><br><integer-value><br><enumeration-type>:'unspecified' 'recto' 'verso'<br><br>-- empty --, <character-string><br>-- empty --, \$colour-exp<br><br><integer-value><br><character-string><br><br><character-string><br><character-string><br><character-string><br><character-string><br><br><asn.1-object-id><br><character-string><br><br>\$method-info<br><br><character-string><br><character-string><br><br>\$method-info<br>\$key-info<br>\$method-info<br>\$key-info<br><br><character-string><br><character-string><br>\$name<br><br><asn.1-object-id><br><character-string><br><character-string> | + +ISO/IEC 8613-1:1994(E) + +Table F.1 – List of attributes and data types (continued) + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b>DEFINE (sealed-doc-bodyparts,"</b><br><b>#sealing-id</b><br><b>#sealed-constituents</b><br><b>#object-class-identifiers</b><br><b>#presentation-style-identifiers</b><br><b>#layout-style-identifiers</b><br><b>#object-identifiers</b><br><b>#privileged-recipients</b><br><b>#doc-body-part-seal</b><br><b>")</b> | <br><integer-value><br><br><reference-to-object-class-id>...<br><reference-to-style-id>...<br><reference-to-style-id>...<br><reference-to-object-id>...<br>\$name...<br>\$seal-data | +| <b>DEFINE (protected-doc-parts,"</b><br><b>#protected-doc-part-id</b><br><b>#priv-recipients-info</b><br><b>#privileged-recipients</b><br><b>#encipherment-method-info</b><br><b>#encipherment-key-info</b><br><b>")</b> | <br><integer-value> <integer-value><br><br>\$name...<br>\$method-info<br>\$key-info | +| <b>DEFINE (graphic-rendition-aspect,"</b><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><b>")</b> | <enumeration-type>:'cancel' 'increased-intensity'<br>'decreased-intensity' 'italicized' 'underline' 'slowly-<br>blinking' 'rapidly-blinking' 'negative-image' 'crossed-out'<br>'primary-font' 'first-alternative-font' 'second-alternative-<br>font' 'third-alternative-font' 'fourth-alternative-font' 'fifth-<br>alternative-font' 'sixth-alternative-font' 'seventh-<br>alternative-font' 'eighth-alternative-font' 'ninth-alternative-<br>font' 'doubly-underlined' 'normal-intensity' 'not-italicized'<br>'not-underlined' 'steady' 'variable-spacing' 'positive-<br>image' 'not-crossed-out' 'black-foreground' 'red-<br>foreground' 'green-foreground' 'yellow-foreground' 'blue-<br>foreground' 'magenta-foreground' 'cyan-foreground'<br>'white-foreground' 'select-character-foreground-colour'<br>'black-background' 'red-background' 'green-background'<br>'yellow-background' 'blue-background' 'magenta-<br>background' 'cyan-background' 'white-background'<br>'select-character-background-colour' 'not-variable-<br>spacing'... | +| <b>DEFINE (char-pres-atts,"</b><br><b>#character-path</b><br><b>#line-progression</b><br><b>#character-orientation</b><br><b>#initial-offset</b><br><b>#horizontal-coordinate</b><br><b>#vertical-coordinate</b><br><b>#character-spacing</b><br><b>#line-spacing</b><br><b>#alignment</b><br><br><b>#line-layout-table</b><br><b>#tabulation-reference</b><br><b>#tabulation-position</b><br><b>#alignment</b><br><br><b>#alignment-character-string</b><br>...<br><b>#graphic-rendition</b><br><b>#formatting-indicator</b><br><b>#character-fonts</b><br><b>#primary-font-spec</b><br><b>#font-size</b><br><b>#font-identifier</b><br><b>#first-alternative-font-spec</b><br><b>#font-size</b><br><b>#font-identifier</b><br><b>#second-alternative-font-spec</b><br><b>#font-size</b><br><b>#font-identifier</b><br><b>#third-alternative-font-spec</b><br><b>#font-size</b><br><b>#font-identifier</b><br><b>#fourth-alternative-font-spec</b><br><b>#font-size</b><br><b>#font-identifier</b> | <br><enumeration-type>:'d0' 'd90' 'd180' 'd270'<br><enumeration-type>:'d90' 'd270'<br><enumeration-type>:'d0' 'd90' 'd180' 'd270'<br><br><integer-value><br><integer-value><br><integer-value><br><integer-value><br><enumeration-type>:'start-aligned' 'end-aligned'<br>'centred' 'justified'<br><br><integer-value><br><integer-value><br><enumeration-type>:'start-aligned' 'end-aligned'<br>'centred' 'aligned-around'<br><character-string><br><br>\$graphic-rendition-aspect...<br><enumeration-type>:'no' 'yes'<br><br><br><integer-value><br><integer-value><br><br><integer-value><br><integer-value><br><br><integer-value><br><integer-value><br><br><integer-value><br><integer-value><br><br><integer-value><br><integer-value> | + + ITU-T Rec. T.411 (1993 E) 59 + +Table F.1 – List of attributes and data types (*continued*) + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|-----------------------------------------|-------------------------------------------------------------------| +| <b>#fifth-alternative-font-spec</b> | | +| <b>#font-size</b> | <integer-value> | +| <b>#font-identifier</b> | <integer-value> | +| <b>#sixth-alternative-font-spec</b> | | +| <b>#font-size</b> | <integer-value> | +| <b>#font-identifier</b> | <integer-value> | +| <b>#seventh-alternative-font-spec</b> | | +| <b>#font-size</b> | <integer-value> | +| <b>#font-identifier</b> | <integer-value> | +| <b>#eighth-alternative-font-spec</b> | | +| <b>#font-size</b> | <integer-value> | +| <b>#font-identifier</b> | <integer-value> | +| <b>#ninth-alternative-font-spec</b> | | +| <b>#font-size</b> | <integer-value> | +| <b>#font-identifier</b> | <integer-value> | +| <b>#graphic-character-subrepertoire</b> | <integer-value> | +| <b>#itemization</b> | | +| <b>#identifier-alignment</b> | <enumeration-type>:'no-itemization' 'start-aligned' 'end-aligned' | +| <b>#identifier-start-offset</b> | <integer-value> | +| <b>#identifier-end-offset</b> | <integer-value> | +| <b>#widow-size</b> | <integer-value> | +| <b>#orphan-size</b> | <integer-value> | +| <b>#graphic-character-sets</b> | <escape-sequence>... | +| <b>#indentation</b> | <integer-value> | +| <b>#kerning-offset</b> | | +| <b>#start-edge-offset</b> | <integer-value> | +| <b>#end-edge-offset</b> | <integer-value> | +| <b>#proportional-line-spacing</b> | <enumeration-type>:'no' 'yes' | +| <b>#pairwise-kerning</b> | <enumeration-type>:'no' 'yes' | +| <b>#first-line-offset</b> | <integer-value> | +| <b>#code-extension-announcers</b> | <escape-sequence>... | +| ") | | +| <b>DEFINE (ras-pres-atts,"</b> | | +| <b>#pel-path</b> | <enumeration-type>:'d0' 'd90' 'd180' 'd270' | +| <b>#line-progression</b> | <enumeration-type>:'d90' 'd270' | +| <b>#pel-transmission-density</b> | <enumeration-type>:'p6' 'p5' 'p4' 'p3' 'p2' 'p1' | +| <b>#initial-offset</b> | | +| <b>#horizontal-coordinate</b> | <integer-value> | +| <b>#vertical-coordinate</b> | <integer-value> | +| <b>#clipping</b> | | +| <b>#first-coordinate-pair</b> | | +| <b>#x-coordinate</b> | <integer-value> | +| <b>#y-coordinate</b> | <integer-value> | +| <b>#second-coordinate-pair</b> | | +| <b>#x-coordinate</b> | <integer-value> | +| <b>#y-coordinate</b> | <integer-value> | +| <b>#pel-spacing</b> | <enumeration-type>:'null' | +| <b>#length</b> | <integer-value> | +| <b>#pel-spaces</b> | <integer-value> | +| <b>#spacing-ratio</b> | | +| <b>#line-spacing-value</b> | <integer-value> | +| <b>#pel-spacing-value</b> | <integer-value> | +| <b>#image-dimensions</b> | | +| <b>#width-controlled</b> | | +| <b>#minimum-width</b> | <integer-value> | +| <b>#preferred-width</b> | <integer-value> | +| <b>#height-controlled</b> | | +| <b>#minimum-height</b> | <integer-value> | +| <b>#preferred-height</b> | <integer-value> | +| <b>#area-controlled</b> | | +| <b>#minimum-width</b> | <integer-value> | +| <b>#preferred-width</b> | <integer-value> | +| <b>#minimum-height</b> | <integer-value> | +| <b>#preferred-height</b> | <integer-value> | +| <b>#aspect-ratio-flag</b> | <enumeration-type>:'fixed' 'variable' | +| <b>#automatic</b> | <enumeration-type>:'null' | +| ") | | + +Table F.1 – List of attributes and data types (*continued*) + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b>DEFINE (geo-pres-atts,"</b><br><b>#encoding-announcer</b><br><b>#line-rendition</b><br><b>#individual-part</b><br><b>#asf-part</b><br><b>#line-type-asf</b><br><b>#line-width-asf</b><br><b>#line-colour-asf</b><br><b>#bundle-part</b><br><b>#marker-rendition</b><br><b>#individual-part</b><br><b>#asf-part</b><br><b>#marker-type-asf</b><br><b>#marker-size-asf</b><br><b>#marker-colour-asf</b><br><b>#bundle-part</b><br><b>#text-rendition</b><br><b>#individual-part</b><br><b>#asf-part</b><br><b>#text-font-asf</b><br><b>#text-precision-asf</b><br><b>#character-expansion-factor-asf</b><br><b>#character-spacing-asf</b><br><b>#text-colour-asf</b><br><b>#bundle-part</b><br><b>#filled-area-rendition</b><br><b>#individual-part</b><br><b>#pattern-table-part</b><br><b>#asf-part</b><br><b>#interior-style-asf</b><br><b>#fill-colour-asf</b><br><b>#hatch-index-asf</b><br><b>#pattern-index-asf</b><br><b>#bundle-part</b><br><b>#edge-rendition</b><br><b>#individual-part</b><br><b>#asf-part</b><br><b>#edge-type-asf</b><br><b>#edge-width-asf</b><br><b>#edge-colour-asf</b><br><b>#bundle-part</b><br><b>#colour-representations</b><br><b>#background-colour</b><br><b>#colour-table-part</b><br><b>#transparency-specification</b><br><b>#transformation-of-layout-object-specification</b><br><b>#region-of-interest</b><br><b>#automatic</b><br><b>#rectangle</b><br><b>#first-corner</b><br><b>#second-corner</b><br><b>#picture-orientation</b><br><b>#picture-dimensions</b><br><b>#width-controlled</b><br><b>#minimum-width</b><br><b>#preferred-width</b><br><b>#height-controlled</b><br><b>#minimum-height</b><br><b>#preferred-height</b><br><b>#area-controlled</b><br><b>#minimum-width</b><br><b>#preferred-width</b><br><b>#minimum-height</b><br><b>#preferred-height</b><br><b>#aspect-ratio-flag</b><br><b>#automatic</b><br><b>)</b><br><b>DEFINE (page-set-attributes,"</b><br><b>#layout-stream-categories</b><br><b>#layout-stream-sub-categories</b><br><b>)</b> | <character-string><br><character-string><br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br>\$bundle-part-val<br><character-string><br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br>\$bundle-part-val<br><character-string><br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br>\$bundle-part-val<br><character-string><br><character-string>...<br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br>\$bundle-part-val<br><character-string><br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br>\$bundle-part-val<br><character-string><br><character-string><br><character-string><br><character-string><br><enumeration-type>:'null'<br><character-string><br><character-string><br><enumeration-type>:'d0' 'd90' 'd180' 'd270'<br><integer-value><br><integer-value><br><integer-value><br><integer-value><br><integer-value><br><integer-value><br><integer-value><br><integer-value><br><enumeration-type>:'fixed' 'variable'<br><enumeration-type>:'null'<br><character-string>...<br><character-string>... | + +Table F.1 – List of attributes and data types (*continued*) + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b>DEFINE (page-attributes,"</b><br><b>#dimensions</b><br><b>#transparency</b><br><b>#content-architecture-class</b><br><b>#presentation-attributes</b><br><b>#external-content-architecture-</b><br><b>presentation-attributes</b><br><b>#page-position</b><br><b>#horizontal-position</b><br><b>#vertical-position</b><br><b>#medium-type</b><br><b>#presentation-style</b><br><b>#colour</b><br><b>#colour-of-layout-object</b><br><b>#object-colour-table</b><br><b>#content-background-colour</b><br><br><b>#content-foreground-colour</b><br><br><b>#content-colour-table</b><br><b>#sealing</b><br><b>#sealing-status</b><br><b>#sealing-ids</b><br><b>#layout-stream-categories</b><br><b>#layout-stream-sub-categories</b><br><b>")</b><br><b>DEFINE (frame-attributes,"</b><br><b>#position</b><br><b>#fixed-position</b><br><b>#horizontal-position</b><br><b>#vertical-position</b><br><b>#dimensions</b><br><b>#transparency</b><br><b>#layout-path</b><br><b>#permitted-categories</b><br><b>#colour</b><br><b>#colour-of-layout-object</b><br><b>#object-colour-table</b><br><b>#content-background-colour</b><br><br><b>#content-foreground-colour</b><br><br><b>#content-colour-table</b><br><b>#border</b><br><b>#sealing</b><br><b>#sealing-status</b><br><b>#sealing-ids</b><br><b>#layout-stream-categories</b><br><b>#layout-stream-sub-categories</b><br><b>")</b><br><b>DEFINE (block-attributes,"</b><br><b>#position</b><br><b>#fixed-position</b><br><b>#horizontal-position</b><br><b>#vertical-position</b><br><b>#dimensions</b><br><b>#transparency</b><br><b>#presentation-attributes</b><br><b>#external-content-architecture-</b><br><b>presentation-attributes</b><br><b>#presentation-style</b><br><b>#colour</b><br><b>#colour-of-layout-object</b><br><b>#object-colour-table</b><br><b>#content-background-colour</b><br><br><b>#content-foreground-colour</b><br><br><b>#content-colour-table</b><br><b>#border</b> | <b>\$case-i-dimensions-val</b><br><b><enumeration-type>:'transparent' 'opaque'</b><br><b><asn.1-object-id></b><br><b>\$char-pres-atts \$ras-pres-atts \$geo-pres-atts</b><br><b>-- external --</b><br><br><b>-- empty --, <integer-value></b><br><b>-- empty --, <integer-value></b><br><b>\$medium-type-val</b><br><b><reference-to-style-id></b><br><b><enumeration-type>:'colourless' 'white'</b><br><b>\$colour-exp</b><br><b>\$colour-tbl</b><br><b><enumeration-type>:'content-background-</b><br><b>transparency', \$colour-exp</b><br><b><enumeration-type>:'implementation-defined'</b><br><b>'content-foreground-transparency', \$colour-exp</b><br><b>\$colour-tbl</b><br><br><b><enumeration-type>:'no' 'yes'</b><br><b><integer-value>...</b><br><b><character-string>...</b><br><b><character-string>...</b><br><br><br><b>-- empty --, <integer-value></b><br><b>-- empty --, <integer-value></b><br><b>\$case-i-dimensions-val</b><br><b><enumeration-type>:'transparent' 'opaque'</b><br><b><enumeration-type>:'d0' 'd90' 'd180' 'd270'</b><br><b>-- empty --, <character-string></b><br><b><enumeration-type>:'colourless' 'white'</b><br><b>\$colour-exp</b><br><b>\$colour-tbl</b><br><b><enumeration-type>:'content-background-transparency',</b><br><b>\$colour-exp</b><br><b><enumeration-type>:'implementation-defined'</b><br><b>'content-foreground-transparency', \$colour-exp</b><br><b>\$colour-tbl</b><br><b>-- empty --, \$border-val</b><br><br><b><enumeration-type>:'no' 'yes'</b><br><b><integer-value>...</b><br><b><character-string>...</b><br><b><character-string>...</b><br><br><br><b><integer-value></b><br><b><integer-value></b><br><b>\$case-i-dimensions-val</b><br><b><enumeration-type>:'transparent' 'opaque'</b><br><b>\$char-pres-atts, \$ras-pres-atts, \$geo-pres-atts</b><br><b>-- external --</b><br><br><b><reference-to-style-id></b><br><b><enumeration-type>:'colourless' 'white'</b><br><b>\$colour-exp</b><br><b>\$colour-tbl</b><br><b><enumeration-type>:'content-background-transparency',</b><br><b>\$colour-exp</b><br><b><enumeration-type>:'implementation-defined'</b><br><b>'content-foreground-transparency', \$colour-exp</b><br><b>\$colour-tbl</b><br><b>-- empty --, \$border-val</b> | + +Table F.1 – List of attributes and data types (*continued*) + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b>#sealing</b><br><b>#sealing-status</b><br><b>#sealing-ids</b><br><b>#layout-stream-categories</b><br><b>#layout-stream-sub-categories</b><br><b>)</b><br><b>DEFINE (comp-log-attributes,"</b><br><b>#protection</b><br><b>#layout-style</b><br><b>#sealing</b><br><b>#sealing-status</b><br><b>#sealing-ids</b><br><b>)</b><br><b>DEFINE (basic-log-attributes,"</b><br><b>#presentation-attributes</b><br><b>#character-attributes</b><br><b>#raster-graphics-attributes</b><br><b>#geometric-graphics-attributes</b><br><b>#external-content-architecture-</b><br><b>presentation-attributes</b><br><b>#content-architecture-class</b><br><b>#protection</b><br><b>#presentation-style</b><br><b>#layout-style</b><br><b>#sealing</b><br><b>#sealing-status</b><br><b>#sealing-ids</b><br><b>)</b><br><b>-- document profile --</b><br><b>Generic-layout-structure</b><br><br><b>Specific-layout-structure</b><br><b>Generic-logical-structure</b><br><br><b>Specific-logical-structure</b><br><b>Layout-styles</b><br><b>Presentation-styles</b><br><b>Sealed-profiles</b><br><b>Enciphered-profiles</b><br><b>Pre-enciphered-body-parts</b><br><b>Post-enciphered-body-parts</b><br><b>External-document-class</b><br><b>Resource-document</b><br><b>Resources</b><br><b>#resource-identifier</b><br><b>#resource-object-class-identifier</b><br><b>...</b><br><b>Document-application-profile</b><br><br><b>Document-application-profile-defaults</b><br><b>#content-architecture-class</b><br><b>#content type</b><br><b>#dimensions</b><br><b>#transparency</b><br><b>#colour</b><br><b>#colour-of-layout-object</b><br><b>#object-colour-table</b><br><b>#content-background-colour</b><br><br><b>#content-foreground-colour</b><br><br><b>#content-colour-table</b><br><b>#border</b><br><b>#layout-path</b><br><b>#page-position</b><br><b>#horizontal-position</b><br><b>#vertical-position</b><br><b>#medium-type</b><br><b>#block-alignment</b> | <b><enumeration-type>:'no' 'yes'</b><br><b><integer-value>...</b><br><b><character-string>...</b><br><b><character-string>...</b><br><br><b><enumeration-type>:'unprotected' 'protected'</b><br><b><reference-to-style-id></b><br><br><b><enumeration-type>:'no' 'yes'</b><br><b><integer-value>...</b><br><br><b>\$char-pres-atts</b><br><b>\$ras-pres-atts</b><br><b>\$geo-pres-atts</b><br><b>-- external --</b><br><br><b><asn.1-object-id></b><br><b><enumeration-type>:'unprotected' 'protected'</b><br><b><reference-to-style-id></b><br><b><reference-to-style-id></b><br><br><b><enumeration-type>:'no' 'yes'</b><br><b><integer-value>...</b><br><br><b><enumeration-type>:'partial-generator-set' 'complete-generator-set' 'factor-set'</b><br><b><enumeration-type>:'present'</b><br><b><enumeration-type>:'partial-generator-set'</b><br><b>complete-generator-set' 'factor-set'</b><br><b><enumeration-type>:'present'</b><br><b><enumeration-type>:'present'</b><br><b><enumeration-type>:'present'</b><br><b><enumeration-type>:'present'</b><br><b><enumeration-type>:'present'</b><br><b><enumeration-type>:'present'</b><br><b><enumeration-type>:'present'</b><br><b><asn.1-object-id>, <character-string></b><br><b><asn.1-object-id>, <character-string></b><br><br><b><character-string></b><br><b><reference-to-object-class-id></b><br><br><b><asn.1-object-id>, <enumeration-type>:'group-4-facsimile'</b><br><br><b>-- empty --, <asn.1-object-id></b><br><b><enumeration-type 'formatted-raster-graphics'</b><br><b>\$case-i-dimensions-val</b><br><b><enumeration-type>:', 'transparent' 'opaque'</b><br><b><enumeration-type>:', 'colourless' 'white'</b><br><b>\$colour-exp</b><br><b>\$colour-tbl</b><br><b><enumeration-type>:'content-background-transparency', \$colour-exp</b><br><b><enumeration-type>:'implementation-defined' 'content-foreground-transparency', \$colour-exp</b><br><b>\$colour-tbl</b><br><b>-- empty --, \$border-val</b><br><b><enumeration-type>:'d0' 'd90' 'd180' 'd270'</b><br><br><b><integer-value></b><br><b><integer-value></b><br><b>\$medium-type-val</b><br><b><enumeration-type>:'right-hand' 'left-hand' 'centred' 'null'</b> | + +Table F.1 – List of attributes and data types (*continued*) + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b>#type-of-coding</b><br><b>#character-content-defaults</b><br><b>#alignment</b><br><br><b>#character-orientation</b><br><b>#character-path</b><br><b>#character-spacing</b><br><b>#graphic-character-sets</b><br><b>#graphic-character-subrepertoire</b><br><b>#graphic-rendition</b><br><b>#indentation</b><br><b>#kerning-offset</b><br><b>#start-edge-offset</b><br><b>#end-edge-offset</b><br><b>#line-progression</b><br><b>#line-spacing</b><br><b>#orphan-size</b><br><b>#proportional-line-spacing</b><br><b>#widow-size</b><br><b>#pairwise-kerning</b><br><b>#raster-graphics-content-defaults</b><br><b>#clipping</b><br><b>#first-coordinate-pair</b><br><b>#second-coordinate-pair</b><br><b>#pel-path</b><br><b>#line-progression</b><br><b>#initial-offset</b><br><b>#horizontal-coordinate</b><br><b>#vertical-coordinate</b><br><b>#pel-transmission-density</b><br><b>#pel-spacing</b><br><b>#length</b><br><b>#pel-spaces</b><br><b>#spacing-ratio</b><br><b>#line-spacing-value</b><br><b>#pel-spacing-value</b><br><b>#image-dimensions</b><br><b>#width-controlled</b><br><b>#minimum-width</b><br><b>#preferred-width</b><br><b>#height-controlled</b><br><b>#minimum-height</b><br><b>#preferred-height</b><br><b>#area-controlled</b><br><b>#minimum-width</b><br><b>#preferred-width</b><br><b>#minimum-height</b><br><b>#preferred-height</b><br><b>#aspect-ratio-flag</b><br><b>#automatic</b><br><b>#compression</b><br><b>#number-of-pels-per-tile-line</b><br><b>#number-of-lines-per-tile</b><br><b>#tiling-offset</b><br><b>#tiling-types</b><br><br><b>#number-of-pels-per-line</b><br><b>#number-of-discarded-pels</b><br><b>#geometric-graphics-content-defaults</b><br><b>#encoding-announcer</b><br><b>#line-rendition</b><br><b>#individual-part</b><br><b>#asf-part</b><br><b>#line-type-asf</b><br><b>#line-width-asf</b><br><b>#line-colour-asf</b><br><b>#bundle-part</b> | <enumeration-type>:'t6' 't6m <sup>a)</sup> '<asn.1-object-id><br><br><enumeration-type>:'start-aligned' 'end-aligned'<br>'centred' 'justified'<br><enumeration-type>:'d0' 'd90' 'd180' 'd270'<br><enumeration-type>:'d0' 'd90' 'd180' 'd270'<br><integer-value><br><escape-sequence>...<br><integer-value><br>\$graphic-rendition-aspect...<br><integer-value><br><br><integer-value><br><integer-value><br><enumeration-type>:'d90' 'd270'<br><integer-value><br><integer-value><br><enumeration-type>:'no' 'yes'<br><integer-value><br><enumeration-type>:'no' 'yes'<br><br><integer-value> <integer-value><br><integer-value> <integer-value><br><enumeration-type>:'d0' 'd90' 'd180' 'd270'<br><enumeration-type>:'d90' 'd270'<br><br><integer-value><br><integer-value><br><enumeration-type>:'p6' 'p5' 'p4' 'p3' 'p2' 'p1'<br><enumeration-type>:'null'<br><integer-value><br><integer-value><br><br><integer-value><br><integer-value><br><br><integer-value><br><integer-value><br><integer-value><br><integer-value><br><enumeration-type>:'fixed' 'variable'<br><enumeration-type>:'null'<br><enumeration-type>:'uncompressed' 'compressed'<br><integer-value><br><integer-value><br><integer-value> <integer-value><br><enumeration-type>:'null-background' 'null-foreground'<br>'t6-encoded' 't4-one-dimensional-encoded'<br>'t4-two-dimensional-encoded' 'bitmap-encoded'<br><integer-value><br><integer-value><br><br><character-string><br><br><character-string><br><br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br>\$bundle-part-val | +| a) | The use of 't6m' is applicable to the ITU-T Rec. T.410-Series only. | + +Table F.1 – List of attributes and data types (*continued*) + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b>#marker-rendition</b><br><b>#individual-part</b><br><b>#asf-part</b><br><b>#marker-type-asf</b><br><b>#marker-width-asf</b><br><b>#marker-colour-asf</b><br><b>#bundle-part</b><br><b>#text-rendition</b><br><b>#individual-part</b><br><b>#asf-part</b><br><b>#text-font-asf</b><br><b>#text-precision-asf</b><br><b>#character-expansion-factor-asf</b><br><b>#character-spacing-asf</b><br><b>#text-colour-asf</b><br><b>#bundle-part</b><br><b>#filled-area-rendition</b><br><b>#individual-part</b><br><b>#pattern-table-part</b><br><b>#asf-part</b><br><b>#interior-style-asf</b><br><b>#fill-colour-asf</b><br><b>#hatch-index-asf</b><br><b>#pattern-index-asf</b><br><b>#bundle-part</b><br><b>#edge-rendition</b><br><b>#individual-part</b><br><b>#asf-part</b><br><b>#edge-type-asf</b><br><b>#edge-width-asf</b><br><b>#edge-colour-asf</b><br><b>#bundle-part</b><br><b>#colour-representation</b><br><b>#background-colour</b><br><b>#colour-table-part</b><br><b>#transparency-specification</b><br><b>#transformation-of-layout-object-specification</b><br><b>#region-of-interest</b><br><b>#automatic</b><br><b>#rectangle</b><br><b>#first-corner</b><br><b>#second-corner</b><br><b>#picture-orientation</b><br><b>#picture-dimensions</b><br><b>#width-controlled</b><br><b>#minimum-width</b><br><b>#preferred-width</b><br><b>#height-controlled</b><br><b>#minimum-height</b><br><b>#preferred-height</b><br><b>#area-controlled</b><br><b>#minimum-width</b><br><b>#preferred-width</b><br><b>#minimum-height</b><br><b>#preferred-height</b><br><b>#aspect-ratio-flag</b><br><b>#automatic</b><br><b>#external-content-architecture-defaults</b><br><b>Document-architecture-class</b><br><b>Content-architecture-classes</b><br><b>Interchange-format-class</b><br><b>ODA version</b><br><b>#standard-or-recommendation</b><br><b>#publication-date</b><br><b>Alternative-features-sets</b><br>...<br>-- non-basic document characteristics --<br><b>Profile-character-sets</b> | <character-string><br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><b>\$bundle-part-val</b><br><character-string><br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><b>\$bundle-part-val</b><br><character-string><br><character-string><br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><b>\$bundle-part-val</b><br><character-string><br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><enumeration-type>:'bundled' 'individual'<br><b>\$bundle-part-val</b><br><character-string><br><character-string><br><character-string><br><character-string><br><enumeration-type>:'null'<br><character-string><br><character-string><br><enumeration-type>:'d0' 'd90' 'd180' 'd270'<br><integer-value><br><integer-value><br><integer-value><br><integer-value><br><integer-value><br><integer-value><br><integer-value><br><enumeration-type>:'fixed' 'variable'<br><enumeration-type>:'null'<br>-- external --<br><enumeration-type>:'formatted' 'processable'<br>'formatted-processable'<br><asn.1-object-id>...<br><enumeration-type>:'if-a' 'if-b'<br><character-string><br><character-string><br><reference-to-object-id>...<br><escape-sequence>... | + +Table F.1 – List of attributes and data types (*continued*) + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b>Comments-character-sets</b><br><b>Alternative-representation-character-sets</b><br><b>Page-dimensions</b><br><b>Medium-types</b><br><b>Layout-paths</b><br><b>Protections</b><br><b>Block-alignments</b><br><br><b>Fill-orders</b><br><b>Transparencies</b><br><b>Colours</b><br><b>Colours-of-layout-object</b><br>#colour-access-modes<br>#direct-colour-expressions<br><br>...<br><b>Object-colour-tables</b><br><b>Content-background-colours</b><br><br><b>Content-foreground-colours</b><br><br><b>Content-colour-tables</b><br><b>Borders</b><br><b>Page-positions</b><br>#horizontal<br>#vertical<br><br>...<br><b>Types-of-coding</b><br><b>Coding-attributes</b><br>#character-coding-attributes<br>#raster-graphics-coding-attributes<br>#compression<br>#number-of-pels-per-tile-line<br>#number-of-pels-per-tile<br>#tiling-offset<br>#tile-types<br><br>#geometric-graphics-coding-attributes<br><b>Presentation-features</b><br>#character-pres-features<br>#raster-pres-features<br>#geometric-pres-features<br>#external-non-basic-pres-features<br>#external-non-basic-coding-attributes<br><br>-- non-basic structure characteristics --<br><b>Number-of-objects-per-page</b><br><br>-- additional document characteristics --<br><b>Unit-scaling</b><br>#unit-scaling-m<br>#unit-scaling-n<br><b>Fonts-list</b><br>#font-identifier<br>#font-reference<br>#user-visible-name<br>#user-readable-comment<br>#font-information<br>#user-readable-comment<br>#precedence-number<br>#font-properties<br><br>...<br><b>Colour-characteristics</b><br>#colour-spaces-present<br>#colour-space-type<br><br>#colour-calibration-type<br><br>#colour-modes-present<br>#minimum-colour-tolerance | <escape-sequence>...<br><escape-sequence>...<br>\$case-iii-dimensions-val...<br>\$medium-type-val...<br><enumeration-type>:'d0' '90' '180' '270'...<br><enumeration-type>:'protected' 'unprotected'...<br><enumeration-type>:'right-hand' 'left-hand' 'centred'<br>'null'...<br><enumeration-type>:'normal' 'reverse'...<br><enumeration-type>:'transparent' 'opaque'...<br><enumeration-type>:'colourless' 'white'...<br><br><enumeration-type>:'direct' 'indirect'...<br>\$colour-exp...<br><br>\$colour-tbl...<br><enumeration-type>:'content-background-transparency',<br>'\$colour-exp'...<br><enumeration-type>:'implementation-defined' 'content-<br>foreground-transparency', '\$colour-exp'...<br>\$colour-tbl...<br>-- empty --, \$border-val...<br><br><integer-value><br><integer-value><br><br><enumeration-type>:'t6' 't6m <sup>a</sup> ', <asn.1-object-id>...<br><br>-- empty --<br><br><enumeration-type>:'compressed' 'uncompressed'<br><integer-value><br><integer-value><br><integer-value> <integer-value><br><enumeration-type>:'null-background' 'null-foreground'<br>'t6-encoded' 't4-one-dimensional-encoded'<br>'t4-two-dimensional-encoded' 'bitmap-encoded'<br>-- empty --<br><br>\$char-pres-atts<br>\$char-pres-atts<br>\$char-pres-atts<br>-- external --<br>-- external --<br><br><integer-value><br><br><integer-value><br><integer-value><br><br><integer-value><br><br><character-string><br><character-string><br><br><character-string><br><integer-value><br>-- as defined in ISO/IEC 9541 --<br><br><enumeration-type>:'RGB' 'CMYK' 'CMY' 'CIELUV'<br>'CIELAB'...<br><enumeration-type>:'no-calibration' 'matrices'<br>'look-up-tables' 'matrices-and-look-up-tables'<br><enumeration-type>:'indexed' 'direct' 'both' | +| a) | The use of 't6m' is applicable to the ITU-T Rec. T.410-Series only. | + +Table F.1 – List of attributes and data types (*continued*) + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|-------------------------------------------------|----------------------------------------------------------| +| <b>#unspecified-tolerance</b> | -- empty -- | +| <b>#specified-tolerance</b> | | +| <b>#tolerance-value</b> | <integer-value>, <real-value> | +| <b>#tolerance-space</b> | <enumeration-type>: 'CIELUV' 'CIELAB' | +| <b>#maximum-number-of-colour-table-entries</b> | <integer-value> | +| <b>#maximum-number-of-look-up-table-entries</b> | <integer-value> | +| <b>#maximum-CMY(K)-grid-size</b> | <integer-value> | +| <b>Colour-spaces-list</b> | | +| <b>#colour-space-id</b> | <integer-value> | +| <b>#colour-space-type</b> | <enumeration-type>: 'RGB' 'CMYK' 'CMY' 'CIELUV' 'CIELAB' | +| <b>#colour-space-name</b> | <character-string> | +| <b>#colour-data-scaling</b> | | +| <b>#colour-scale</b> | <integer-value>, <real-value> | +| <b>#colour-offset</b> | <integer-value>, <real-value> | +| <b>#colour-scale</b> | <integer-value>, <real-value> | +| <b>#colour-offset</b> | <integer-value>, <real-value> | +| <b>#colour-scale</b> | <integer-value>, <real-value> | +| <b>#colour-offset</b> | <integer-value>, <real-value> | +| <b>#colour-scale</b> | <integer-value>, <real-value> | +| <b>#colour-offset</b> | <integer-value>, <real-value> | +| ... | | +| <b>#calibration-data</b> | | +| <b>#reference-white</b> | | +| <b>#xn-value</b> | <integer-value>, <real-value> | +| <b>#yn-value</b> | <integer-value>, <real-value> | +| <b>#zn-value</b> | <integer-value>, <real-value> | +| <b>#matrix-one</b> | | +| <b>#row-1-column-1</b> | <integer-value>, <real-value> | +| <b>#row-1-column-2</b> | <integer-value>, <real-value> | +| <b>#row-1-column-3</b> | <integer-value>, <real-value> | +| <b>#row-2-column-1</b> | <integer-value>, <real-value> | +| <b>#row-2-column-2</b> | <integer-value>, <real-value> | +| <b>#row-2-column-3</b> | <integer-value>, <real-value> | +| <b>#row-3-column-1</b> | <integer-value>, <real-value> | +| <b>#row-3-column-2</b> | <integer-value>, <real-value> | +| <b>#row-3-column-3</b> | <integer-value>, <real-value> | +| <b>#matrix-two</b> | | +| <b>#row-1-column-1</b> | <integer-value>, <real-value> | +| <b>#row-1-column-2</b> | <integer-value>, <real-value> | +| <b>#row-1-column-3</b> | <integer-value>, <real-value> | +| <b>#row-2-column-1</b> | <integer-value>, <real-value> | +| <b>#row-2-column-2</b> | <integer-value>, <real-value> | +| <b>#row-2-column-3</b> | <integer-value>, <real-value> | +| <b>#row-3-column-1</b> | <integer-value>, <real-value> | +| <b>#row-3-column-2</b> | <integer-value>, <real-value> | +| <b>#row-3-column-3</b> | <integer-value>, <real-value> | +| <b>#colour-lookup-table</b> | | +| <b>#number of entries</b> | <integer-value> | +| <b>#slope-m</b> | <integer-value> | +| <b>#offset-n</b> | <integer-value> | +| <b>#colour-table</b> | | +| <b>#index</b> | <integer-value> | +| <b>#red-r</b> | <integer-value>, <real-value> | +| <b>#green-g</b> | <integer-value>, <real-value> | +| <b>#blue-b</b> | <integer-value>, <real-value> | +| ... | | +| <b>#comment</b> | <character-string> | +| <b>#grid specifications</b> | | +| <b>#grid-location</b> | | +| <b>#cyan-value</b> | <integer-value>, <real-value> | +| <b>#yellow-value</b> | <integer-value>, <real-value> | +| <b>#magenta-value</b> | <integer-value>, <real-value> | +| <b>#black-value</b> | <integer-value>, <real-value> | +| <b>#grid-value</b> | | +| <b>#grid-point-x</b> | <real-value> | +| <b>#grid-point-y</b> | <real-value> | +| <b>#grid-point-z</b> | <real-value> | +| ... | | +| ... | | + +Table F.1 – List of attributes and data types (*continued*) + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|--------------------------------------|--------------------------------------------| +| -- document management attributes -- | | +| Title | <character-string> | +| Subject | <character-string> | +| Document-type | <character-string> | +| Document-reference | <asn.1-object-id>, <character-string> | +| Abstract | <character-string> | +| Keywords | <character-string>... | +| Document-date-and-time | <character-string> | +| Creation-date-and-time | <character-string> | +| Local-filing-date-and-time | <character-string>... | +| Expiry-date-and-time | <character-string> | +| Start-date-and-time | <characters-string> | +| Purge-date-and-time | <character-string> | +| Release-date-and-time | <character-string> | +| Revision-history | | +| #revision-date-and-time | <character-string> | +| #version-identifier | <character-string> | +| #revisers | | +| #names | \$name... | +| #position | <character-string>... | +| #organization | <character-string>... | +| ... | | +| #version-reference | <asn.1-object-id>, <character-string> | +| #user-comments | <character-string>... | +| ... | | +| Organizations | <character-string>... | +| Preparers | | +| #personal-name | \$name | +| #organization | <character-string> | +| ... | | +| Owners | | +| #personal-name | \$name | +| #organization | <character-string> | +| ... | | +| Authors | | +| #personal-name | \$name | +| #organization | <character-string> | +| ... | | +| Copyright | | +| #copyright-information | <character-string>... | +| #copyright-dates | <character-string>... | +| ... | | +| Status | <character-string> | +| User-specific-codes | <character-string>... | +| Distribution-list | | +| #personal-name | \$name | +| #organizations | <character-string>... | +| ... | | +| Additional-information | -- any value -- | +| References-to-other-documents | (<asn.1-object-id>, <character-string>)... | +| Superseded-documents | <asn.1-object-id>... | +| Local-file-references | | +| #file-name | <character-string> | +| #location-of-document | <character-string> | +| #user-comments | <character-string> | +| ... | | +| Document-size | <integer-value> | +| Number-of-pages | <integer-value> | +| Languages | <character-string>... | +| Authorization | | +| #personal-name | \$name | +| #authorization-organization | <character-string> | +| Security-classification | <character-string> | +| Access-rights | <character-string>... | +| -- Document-security-attributes -- | | +| Sealed-information-encoding | <asn.1-object-id> | +| ODA-security-label | | +| #ODA-label-text | <character-string> | +| #ODA-label-data | <character-string> | + +Table F.1 – List of attributes and data types (*continued*) + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b>Sealed-doc-profiles</b><br>#sealed-doc-prof-descriptor-id<br>#privileged-recipients<br>#doc-prof-seal<br>...<br>Pre-sealed-doc-bodyparts<br>Post-sealed-doc-bodyparts<br>Enciphered-doc-profiles<br>Pre-enciphered-doc-profiles<br>Post-enciphered-doc-profiles<br><br>-- layout object class --<br><b>Object-type</b><br><br><b>Object-class-identifier</b><br><b>Generator-for-subordinates</b><br><b>Content-portions</b><br><b>Position</b><br>#fixed-position<br>#horizontal-position<br>#vertical-position<br>#variable-position<br>#offset<br>#separation<br>#alignment<br>#fill-order<br><b>Dimensions</b><br><b>Transparency</b><br><b>Content-architecture-class</b><br><b>Presentation-attributes</b><br>#character-attributes<br>#raster-graphics-attributes<br>#geometric-graphics-attributes<br>#external-content-architecture-<br>presentation-attributes<br><b>Default-value-lists</b><br>#page-set-attributes<br>#page-attributes<br>#frame-attributes<br>#block-attributes<br><b>User-readable-comments</b><br><b>Bindings</b><br>#binding-name<br>#binding-value<br>...<br><b>Content-generator</b><br><b>Layout-path</b><br><b>Layout-stream-categories</b><br><b>Layout-stream-sub-categories</b><br><b>Permitted-categories</b><br><b>User-visible-name</b><br><b>Page-position</b><br>#horizontal-position<br>#vertical-position<br><b>Medium-type</b><br><b>Presentation-style</b><br><b>Logical-source</b><br><b>Balance</b><br><br><b>Colour</b><br><b>Colour-of-layout-object</b><br><b>Content-background-colour</b><br><br><b>Content-foreground-colour</b><br><br><br><b>Content-colour-table</b><br><b>Border</b><br><b>Resource</b> | <character-string><br><br>\$name...<br>\$seal-data<br><br>\$sealed-doc-bodyparts...<br>\$sealed-doc-bodyparts...<br>\$protected-doc-parts...<br>\$protected-doc-parts...<br>\$protected-doc-parts...<br><br><enumeration-type>:'document-layout-root' 'page-set'<br>'page' 'frame' 'block'<br><reference-to-object-class-id><br><construction-expr><br><reference-to-content-portions><br><br>-- empty --, <integer-value><br>-- empty --, <integer-value><br><br>-- empty --, \$offset-val<br>-- empty --, \$separation-val<br><enumeration-type>:'right-hand' 'centred' 'left-hand'<br><enumeration-type>:'normal' 'reverse'<br>\$case-ii-dimensions-val<br><enumeration-type>:'transparent' 'opaque'<br><asn.1-object-id><br><br>\$char-pres-atts<br>\$ras-pres-atts<br>\$geo-pres-atts<br>-- external --<br><br>\$page-set-attributes<br>\$page-attributes<br>\$frame-attributes<br>\$block-attributes<br><character-string><br><br><character-string><br><string-expr><br><br><string-expr><br><enumeration-type>:'d0' 'd90' 'd180' 'd270'<br><character-string>...<br><character-string>...<br><character-string>...<br>-- empty --, <character-string><br><br>-- empty --, <integer-value><br>-- empty --, <integer-value><br>\$medium-type-val<br><reference-to-style-id><br><reference-to-object-class-id><br><enumeration-type>:( 'null', <reference-to-object-<br>class-id>)...<br>\$colour-exp<br>\$colour-tbl<br><enumeration-type>:'content-background-transparency',<br>\$colour-exp<br><enumeration-type>:'implementation-defined' 'content-<br>foreground-transparency', \$colour-exp<br><br>\$colour-tbl<br>-- empty --, \$border-val<br><character-string> | + +Table F.1 – List of attributes and data types (*continued*) + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|--------------------------------------------------------|---------------------------------------------------------------------------------------------| +| Application-comments | <character-string> | +| Enciphered | | +| #enciphered-subordinates | | +| #none-all | <enumeration-type>:'none' 'all' | +| #partial | <integer-value>... | +| #protected-part-id | <character-string> | +| ... | | +| Sealing | | +| #sealing-status | <enumeration-type>:'no' 'yes' | +| #sealing-ids | (<integer-value> <integer value>)... | +| -- layout object -- | | +| Object-type | <enumeration-type>:'document-layout-root' 'page-set' 'page' 'frame' 'block' | +| Object-identifier | <reference-to-object-id> | +| Subordinates | <reference-to-subordinates> | +| Content-portions | <reference-to-content-portions> | +| Object-class | <reference-to-object-class-id> | +| Position | | +| #fixed-position | | +| #horizontal-position | -- empty --, <integer-value> | +| #vertical-position | -- empty --, <integer-value> | +| Dimensions | \$case-iii-dimensions-val | +| Transparencies | <enumeration-type>:'transparent' 'opaque' | +| Content-architecture-class | <asn.1-object-id> | +| Presentation-attributes | | +| #character-attributes | \$char-pres-atts | +| #raster-graphics-attributes | \$ras-pres-atts | +| #geometric-graphics-attributes | \$geo-pres-atts | +| #external-content-architecture-presentation-attributes | -- external -- | +| Default-value-lists | | +| #page-set-attributes | \$page-set-attributes | +| #page-attributes | \$page-attributes | +| #frame-attributes | \$frame-attributes | +| #block-attributes | \$block-attributes | +| User-readable-comments | <character-string> | +| Bindings | | +| #binding-name | <character-string> | +| #binding-value | <string-expr> | +| ... | | +| Layout-path | <enumeration-type>:'d0' 'd90' 'd180' 'd270' | +| Imaging-order | <character-string>... | +| Layout-stream-categories | <character-string>... | +| Layout-stream-sub-categories | <character-string>... | +| Permitted-categories | -- empty --, <character-string> | +| User-visible-name | <character-string> | +| Page-position | | +| #horizontal-position | -- empty --, <integer-value> | +| #vertical-position | -- empty --, <integer-value> | +| Medium-type | \$medium-type-val | +| Presentation-style | <reference-to-style-id> | +| Balance | <enumeration-type>:'null', <reference-to-object-id>... | +| Colour | <enumeration-type>:'colour-of-media' 'coloured' | +| Colour-of-layout-object | \$colour-exp | +| Object-colour-table | \$colour-tbl | +| Content-background-colour | <enumeration-type>:'content-background-transparency', \$colour-exp | +| Content-foreground-colour | <enumeration-type>:'implementation-defined' 'content-foreground-transparency', \$colour-exp | +| Content-colour-table | \$colour-tbl | +| Border | -- empty --, \$border-val | +| Application-comments | <character-string> | +| Primary | <reference-to-object-id> | +| Alternate | <reference-to-object-id> | +| Enciphered | | +| #enciphered-subordinates | | +| #none-all | <enumeration-type>:'none' 'all' | +| #partial | <integer-value>... | +| #protected-part-id | <character-string> | + +Table F.1 – List of attributes and data types (*continued*) + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b>Sealing</b><br><b>#sealing-status</b><br><b>#sealing-ids</b><br><br>-- logical object class --<br><b>Object-type</b><br><br><b>Object-class-identifier</b><br><b>Generator-for-subordinates</b><br><b>Content-portions</b><br><b>Content-architecture-class</b><br><b>Default-value-lists</b><br><b>#composite-logical-attributes</b><br><b>#basic-logical-attributes</b><br><b>User-readable-comments</b><br><b>Bindings</b><br><b>#binding-name</b><br><b>#binding-value</b><br><br>...<br><b>Content-generator</b><br><b>User-visible-name</b><br><b>Presentation-style</b><br><b>Layout-style</b><br><b>Protection</b><br><b>Resource</b><br><b>Application-comments</b><br><b>Enciphered</b><br><b>#enciphered-subordinates</b><br><b>#none-all</b><br><b>#partial</b><br><b>#protected-part-id</b><br><b>Sealing</b><br><b>#sealing-status</b><br><b>#sealing-ids</b><br><br>-- logical object --<br><b>Object-type</b><br><br><b>Object-identifier</b><br><b>Subordinates</b><br><b>Content-portions</b><br><b>Content-architecture-class</b><br><b>Object-class</b><br><b>Default-value-lists</b><br><b>#composite-logical-attributes</b><br><b>#basic-logical-attributes</b><br><b>User-readable-comments</b><br><b>Bindings</b><br><b>#binding-name</b><br><b>#binding-value</b><br><br>...<br><b>Content-generator</b><br><b>User-visible-name</b><br><b>Presentation-style</b><br><b>Layout-style</b><br><b>Protection</b><br><b>Application-comments</b><br><b>Primary</b><br><b>Alternate</b><br><b>Enciphered</b><br><b>#enciphered-subordinates</b><br><b>#none-all</b><br><b>#partial</b><br><b>#protected-part-id</b><br><b>Sealing</b><br><b>#sealing-status</b><br><b>#sealing-ids</b> | <br><enumeration-type>:'no' 'yes'<br>(<integer-value> <integer-value>)...<br><br><br><enumeration-type>:'document-logical-root' 'composite-logical-object' 'basic-logical-object'<br><reference-to-object-class-id><br><construction-expression><br><reference-to-content-portions><br><asn.1-object-id><br><br>\$comp-log-attributes<br>\$basic-log-attributes<br><character-string><br><br><br><character-string><br><string-expr><br><br><br><string-expr><br><character-string><br><reference-to-style-id><br><reference-to-style-id><br><enumeration-type>:'unprotected' 'protected'<br><character-string><br><character-string><br><br><br><enumeration-type>:'none' 'all'<br><integer-value>...<br><character-string><br><br><br><enumeration-type>:'no' 'yes'<br>(<integer-value> <integer-value>)...<br><br><br><enumeration-type>:'document-logical-root' 'composite-logical-object' 'basic-logical-object'<br><reference-to-object-id><br><reference-to-subordinates><br><reference-to-content-portions><br><asn.1-object-id><br><reference-to-object-class><br><br>\$comp-log-attributes<br>\$basic-log-attributes<br><character-string><br><br><br><character-string><br><string-expr><br><br><br><string-expr><br><character-string><br><reference-to-style-id><br><reference-to-style-id><br><enumeration-type>:'unprotected' 'protected'<br><character-string><br><reference-to-object-id><br><reference-to-object-id><br><br><br><enumerated-type>:'none' 'all'<br><integer-value>...<br><character-string>...<br><br><br><enumeration-type>:'no' 'yes'<br>(<integer-value> <integer-value>)... | + +Table F.1 – List of attributes and data types (*continued*) + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| -- <i>layout style</i> --<br><b>Layout-style-identifier</b><br><b>User-readable-comments</b><br><b>User-visible-name</b><br><b>Application-comments</b><br><b>Indivisibility</b><br><br><b>Separation</b><br>#leading-edge<br>#trailing-edge<br>#centre-separation<br><b>Offset</b><br><b>Fill-order</b><br><b>Concatenation</b><br><b>New-layout-object</b><br><br><b>Same-layout-object</b><br>#logical-object<br><br>#layout-object<br><br><b>Layout-object-class</b><br><b>Logical-stream-category</b><br><b>Logical-stream-sub-category</b><br><b>Layout-category</b><br><b>Synchronization</b><br><b>Block-alignment</b><br><b>Derived-from</b><br><b>Sealing</b><br>#sealing-status<br>#sealing-ids<br><b>Floatability-range</b><br>#logical-object<br><br>#layout-object<br><br>#backward-limit<br>#logical-object<br><br>#layout-object<br><br><br>-- <i>protected part descriptors</i> --<br><b>Sealed-doc-prof-descriptor</b><br>#sealed-doc-prof-identifier<br>#sealed-doc-prof-information | <reference-to-style-id><br><character-string><br><character-string><br><character-string><br><reference-to-object-class-id>, <character-string>,<br><enumeration-type>:'page' 'null'<br><br><integer-value><br><integer-value><br><integer-value><br>\$offset-val<br><enumeration-type>:'normal' 'reverse'<br><enumeration-type>:'concatenated' 'non-concatenated'<br><reference-to-object-class-id>, <character-string>,<br><enumeration-type>:'page' 'null'<br><br><reference-to-object-id>, <object-id-expr>, <enumeration-<br>type>:'null'<br><reference-to-object-class-id>, <character-string>,<br><enumeration-type>:'page'<br><reference-to-object-class-id>, <enumeration-type>:'null'<br><character-string>...<br><character-string>...<br>-- <i>empty</i> --, <character-string><br><object-id-expr>, <enumeration-type>:'null'<br><enumeration-type>:'right-hand' 'left-hand' 'centred' 'null'<br><reference-to-style-id><br><br><enumeration-type>:'no' 'yes'<br><integer-value>...<br><br><reference-to-object-id>, <reference-to-object-class-id>,<br><object-id-expr>, <enumeration-type>:'page' 'null'<br><reference-to-object-id>, <reference-to-object-class-id>,<br><object-id-expr>, <enumeration-type>:'page' 'null'<br><br><reference-to-object-id>, <reference-to-object-class-id>,<br><object-id-expr>, <enumeration-type>:'page' 'null'<br><reference-to-object-id>, <reference-to-object-class-id>,<br><object-id-expr>, <enumeration-type>:'page' 'null'<br><br><br><integer-value> <integer-value><br><enumeration-type>:'generic-layout-structure' 'specific-<br>layout-structure' 'generic-logical-structure' 'specific-<br>logical-structure' 'layout-styles' 'presentation-styles'<br>'sealed-profiles' 'enciphered-profiles' 'pre-enciphered-<br>body-parts' 'post-enciphered-body-parts' 'external-<br>document-class' 'resource-document' 'resources'<br>'document-application-profile' 'document-application-<br>profile-defaults' 'document-architecture-class' 'content-<br>architecture-class' 'interchange-format-class' 'oda-<br>version' 'alternative-feature-sets' 'profile-character-sets'<br>'comments-character-sets' 'alternative-representation-<br>character-sets' 'page-dimensions' 'medium-types'<br>'layout-paths' 'protections' 'block-alignments' 'fill-orders'<br>'transparencies' 'colours' 'colours-of-layout-object'<br>'object-colour-tables' 'content-background-colours'<br>'content-foreground-colours' 'content-colour-tables'<br>'borders' 'page-positions' 'types-of-coding' 'coding-<br>attributes' 'presentation-features' 'number-of-objects-per-<br>page' 'unit-scaling' 'fonts-list' 'colour-characteristics'<br>'colour-spaces-list' 'title' 'subject' 'document-reference'<br>'document-type' 'abstract' 'keywords' 'document-date-<br>and-time' 'creation-date-and-time' 'local-filing-date-and-<br>time' 'expiry-date-and-time' 'start-date-and-time' 'purge-<br>date-and-time' 'release-date-and-time' 'revision-history'<br>'organizations' 'preparers' 'owners' 'authors' 'copyright' | + +Table F.1 – List of attributes and data types (*concluded*) + +| Attribute/(Sub) Parameter Name | Data Type Specification | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Enciphered-doc-prof-descriptor<br>#enciphered-doc-prof-identifier<br>#enciphered-doc-prof-information<br>Pre-enciphered-bodypart-descriptor<br>#pre-enciphered-bodypart-identifier<br>#pre-enciphered-bodypart-information<br>Post-enciphered-bodypart-descriptor<br>#post-enciphered-bodypart-identifier<br>#post-enciphered-bodypart-information<br><br>-- presentation style --<br>Presentation-style-identifier<br>User-readable-comments<br>User-visible-name<br>Application-comments<br>Transparency<br>Presentation-attributes<br>#character-attributes<br>#raster-graphics-attributes<br>#geometric-graphics-attributes<br>#external-content-architecture-<br>presentation-attributes<br>Colour<br>Colour-of-layout-object<br>Object-colour-table<br>Content-background-colour<br><br>Content-foreground-colour<br><br>Content-colour-table<br>Border<br>Derived-from<br>Sealing<br>#sealing-status<br>#sealing-ids<br><br>-- content portion --<br>Content-identifier-layout<br>Content-identifier-logical<br>Type-of-coding<br>Coding-attributes<br>#character-coding-attributes<br>#raster-graphics-coding-attributes<br>#compression<br>#number-of-lines<br>#number-of-pels-per-line<br>#number-of-discarded-pels<br>#number-of-pels-per-tile-line<br>#number-of-pels-per-tile<br>#tiling-offset<br>#tile-types<br><br>#geometric-graphics-coding-attributes<br>#external-content-architecture-coding-<br>attributes<br>Alternative-representation<br>Content-information | 'status' 'user-specific-codes' 'distribution-list' 'additional-<br>information' 'references-to-other-documents'<br>'superseded-documents' 'local-file-references'<br>'document-size' 'number-of-pages' 'language'<br>'authorization' 'security-classification' 'access-rights'<br>'oda-security-label' 'sealed-information-encoding'<br>'sealed-document-profiles' 'pre-sealed-document-body-<br>parts' 'post-sealed-document-body-parts' 'enciphered-<br>document-profiles' 'pre-enciphered-document-body-<br>parts' 'post-enciphered-document-body-parts'...<br><br><character-string><br><character-string><br><br><character-string><br><character-string><br><br><character-string><br><character-string><br><br><reference-to-style-id><br><character-string><br><character-string><br><character-string><br><enumeration-type>:'transparent' 'opaque'<br><br>\$char-pres-atts<br>\$ras-pres-atts<br>\$geo-pres-atts<br>-- external --<br><br><enumeration-type>:'colourless' 'white'<br>\$colour-exp<br>\$colour-tbl<br><enumeration-type>:'content-background-transparency',<br>\$colour-exp<br><enumeration-type>:'implementation-defined' 'content-<br>foreground-transparency', \$colour-exp<br>\$colour-tbl<br>-- empty --, \$border-val<br><reference-style-id><br><br><enumeration-type>:'no' 'yes'<br><integer-value>...<br><br><reference-to-content-portions><br><reference-to-content-portions><br><enumeration-type>:'t6' 't6m <sup>a</sup> ', <asn.1-object-id><br><br>-- empty --<br><br><enumeration-type>:'compressed' 'uncompressed'<br><integer-value><br><integer-value><br><integer-value><br><integer-value><br><integer-value><br><integer-value> <integer-value><br><enumeration-type>:'null-background' 'null-foreground' ,<br>'t6-encoded' 't4-one-dimensional-encoded'<br>'t4-two-dimensional-encoded' 'bitmap-encoded'<br>-- empty --<br>-- external --<br><br><character-string><br><content-information> | +| a) | The use of 't6m' is applicable to the ITU-T Rec. T.410-Series only. | + +Table F.2 – List of control functions and data types + +| Control function | Name | Data Type Specification | +|----------------------------------|------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Carriage Return | CR | -- empty -- | +| Graphic Character Composition | GCC | <enumeration-type>:'0' '1' '2' | +| Identify Graphic Subrepertoire | IGS | <integer-value> | +| Line Feed | LF | -- empty -- | +| Partial Line Down | PLD | -- empty -- | +| Partial Line Up | PLU | -- empty -- | +| Set Character Spacing | SCS | <integer-value> | +| Select Graphic Rendition | SGR | <enumeration-type>:'cancel' 'increased-intensity' 'decreased-intensity' 'italicized' 'underlined' 'slowly-blinking' 'rapidly-blinking' 'negative-image' 'crossed-out' 'primary-font' 'first-alternative-font' 'second-alternative-font' 'third-alternative-font' 'fourth-alternative-font' 'fifth-alternative-font' 'sixth-alternative-font' 'seventh-alternative-font' 'eighth-alternative-font' 'ninth-alternative-font' 'doubly-underlined' 'normal-intensity' 'not-italicized' 'not-underlined' 'steady' 'variable-spacing' 'positive-image' 'not-crossed-out' 'black-foreground' 'red-foreground' 'green-foreground' 'yellow-foreground' 'blue-foreground' 'magenta-foreground' 'cyan-foreground' 'white-foreground' 'select-character-foreground-colour' 'black-background' 'red-background' 'green-background' 'yellow-background' 'blue background' 'magenta-background' 'cyan-background' 'white-background' 'select-character-background-colour' 'not-variable-spacing'... | +| Select Character Spacing | SHS | <enumeration-type>:'120' '100' '80' '200' '400' | +| Set Line Spacing | SLS | <integer-value> | +| Start Reverse String | SRS | <enumeration-type>:'start' 'end' | +| Selective Tabulation | STAB | <integer-value> | +| Substitute Character | SUB | -- empty -- | +| Select Line Spacing | SVS | <enumeration-type>:'200' '300' '400' '100' '150' '600' | +| Line Position Backwards | VPB | <integer-value> | +| Line Position Relative | VPR | <integer-value> | +| Code extension control functions | | | +| Escape | ESC | <escape-sequence> | +| Locking Shift Zero | LS0 | -- empty -- | +| Locking Shift One | LS1 | -- empty -- | +| Locking Shift One Right | LS1R | -- empty -- | +| Locking Shift Two | LS2 | -- empty -- | +| Locking Shift Two Right | LS2R | -- empty -- | +| Locking Shift Three | LS3 | -- empty -- | +| Locking Shift Three Right | LS3R | -- empty -- | +| Single Shift Two | SS2 | -- empty -- | +| Single Shift Three | SS3 | -- empty -- | +| Shift In | SI | -- empty -- | +| Shift Out | SO | -- empty -- | +| Backspace | BS | -- empty -- | +| Character Position Backward | HPB | <integer-value> | +| Character Position Relative | HPR | <integer-value> | +| No Justify | JFY | <enumeration-type>:'0' | +| Set Additional Character Spacing | SACS | <integer-value> | +| Set Reduced Character Spacing | SRCS | <integer-value> | +| Set SPACE Width | SSW | <integer-value> | +| Break Permitted Here | BPH | -- empty -- | +| No Break Here | NBH | -- empty -- | +| Parallel Texts | PTX | <enumeration-type>:'end-parallel' 'start-principal' 'start-supplementary' | +| SPACE | SP | -- empty -- | +| Start Of String | SOS | -- empty -- | +| Start Of Original String | SOOS | -- empty -- | +| String Terminator | ST | -- empty -- | + +# Annex G + +## Conformance testing methodology + +(This annex does not form an integral part of this Recommendation | International Standard) + +## G.1 Introduction + +This annex sets the direction for the development of a conformance testing methodology for the ITU-T Rec. T.410-Series | ISO/IEC 8613 in order to check that a given data stream is conforming to the ITU-T Rec. T.410-Series | ISO/IEC 8613. + +NOTE – Additional testing can be required to supplement conformance testing of data streams to determine a level of confidence in an implementation's ability to receive and subsequently process data streams and thereby interoperate successfully with other implementations. This is outside the scope of the ITU-T Rec. T.410-Series | ISO/IEC 8613 conformance testing, but addressed in ISO/IEC TR 10183. + +## G.2 Testing methodology + +The conformance testing methodology for the ITU-T Rec. T.410-Series | ISO/IEC 8613 is restricted to analyzing data streams. Conformance testing does not include testing that implementations can correctly generate and/or receive, and subsequently process particular data streams. However, indirectly this methodology increases the confidence that implementations generate only conforming data streams. Consequently this methodology does not include the specification of test cases or test documents that could be generated or processed by implementations of the ITU-T Rec. T.410-Series | ISO/IEC 8613. + +Any data stream can be tested based on this conformance testing methodology. However, this conformance testing methodology is not concerned with the procedure involved in the submission of data streams for conformance testing. + +## G.3 Reference model for conformance testing + +In analysis of a data stream, three distinct areas of conformance can be identified (see Figure G.1): + +- document representation conformance; +- document profile, structure and content conformance; +- document application profile n (DAP-n) conformance. + +### G.3.1 Document representation conformance + +Document representation conformance is determined by verifying that a data stream conforms to rules specified in other specifications of the ITU-T Rec. T.410-Series | ISO/IEC 8613. These include: + +- ITU-T Rec. T.415 | ISO/IEC 8613-5; +- ITU-T Rec. T.416 | ISO/IEC 8613-6; +- ITU-T Rec. T.417 | ISO/IEC 8613-7; +- ITU-T Rec. T.418 | ISO/IEC 8613-8. + +![Flowchart of Data Stream Conformance to ITU-T Rec. T.410 Series I ISO/IEC 8613. The process starts with a 'Data stream' box, which points to a dashed box labeled 'DATA STREAM ANALYSIS'. Inside this dashed box are three stacked boxes: 'Document representation conformance', 'Document profile, structure and content conformance', and 'DAP-n conformance'. Arrows point from external boxes to these three categories. For 'Document representation conformance', the external box lists 'ITU-T Rec. T.415, T.416, T.417, T.418 I' and 'ISO/IEC 8613-5, 8613-6, 8613-7, 8613-8'. For 'Document profile, structure and content conformance', the external boxes list 'ITU-T Rec. T.412, T.414, T.416, T.417, T.418 I' and 'ISO/IEC 8613-2, 8613-4, 8613-6, 8613-7, 8613-8', followed by 'ISO/IEC 8613-10 (The use of ISO/IEC 8613-10 is applicable to ISO/IEC 8613 only)'. For 'DAP-n conformance', the external boxes list 'ITU-T Rec. T.411 I ISO/IEC 8613-1' and 'DAP-n'. An arrow from the 'DATA STREAM ANALYSIS' dashed box points to a 'Test results' box. A reference 'T0812510-93/d05' is at the bottom right.](e776395ba1d4a6d568f08b406d784abd_img.jpg) + +``` + +graph TD + DS[Data stream] --> DSA[DATA STREAM ANALYSIS] + subgraph DSA [DATA STREAM ANALYSIS] + DRC[Document representation conformance] + DPC[Document profile, structure and content conformance] + DAPN[DAP-n conformance] + end + DSA --> TR[Test results] + + R1["ITU-T Rec. T.415, T.416, T.417, T.418 I +ISO/IEC 8613-5, 8613-6, 8613-7, 8613-8"] --> DRC + R2["ITU-T Rec. T.412, T.414, T.416, T.417, T.418 I +ISO/IEC 8613-2, 8613-4, 8613-6, 8613-7, 8613-8"] --> DPC + R3["ISO/IEC 8613-10 +(The use of ISO/IEC 8613-10 is applicable to ISO/IEC 8613 only)"] --> DPC + R4["ITU-T Rec. T.411 I ISO/IEC 8613-1"] --> DAPN + R5[DAP-n] --> DAPN + +``` + +T0812510-93/d05 + +Flowchart of Data Stream Conformance to ITU-T Rec. T.410 Series I ISO/IEC 8613. The process starts with a 'Data stream' box, which points to a dashed box labeled 'DATA STREAM ANALYSIS'. Inside this dashed box are three stacked boxes: 'Document representation conformance', 'Document profile, structure and content conformance', and 'DAP-n conformance'. Arrows point from external boxes to these three categories. For 'Document representation conformance', the external box lists 'ITU-T Rec. T.415, T.416, T.417, T.418 I' and 'ISO/IEC 8613-5, 8613-6, 8613-7, 8613-8'. For 'Document profile, structure and content conformance', the external boxes list 'ITU-T Rec. T.412, T.414, T.416, T.417, T.418 I' and 'ISO/IEC 8613-2, 8613-4, 8613-6, 8613-7, 8613-8', followed by 'ISO/IEC 8613-10 (The use of ISO/IEC 8613-10 is applicable to ISO/IEC 8613 only)'. For 'DAP-n conformance', the external boxes list 'ITU-T Rec. T.411 I ISO/IEC 8613-1' and 'DAP-n'. An arrow from the 'DATA STREAM ANALYSIS' dashed box points to a 'Test results' box. A reference 'T0812510-93/d05' is at the bottom right. + +**Figure G.1 – Data stream conformance to the ITU-T Rec. T.410 Series I ISO/IEC 8613** + +These rules require that the data stream be encoded in accordance with the ASN.1 basic encoding rules specified in CCITT Rec. X.209 | ISO/IEC 8825 and that the data stream syntax be in accordance with: + +- either the Open Document Interchange Format specified in other specifications of the ITU-T Rec. T.410-Series | ISO/IEC 8613. These include: + - 1) ITU-T Rec. T.415 | ISO/IEC 8613-5; + - 2) ITU-T Rec. T.416 | ISO/IEC 8613-6; + - 3) ITU-T Rec. T.417 | ISO/IEC 8613-7; + - 4) ITU-T Rec. T.418 | ISO/IEC 8613-8. +- or the SGML Document Interchange Format specified in ISO 9069 with a document descriptor in accordance with ISO 8879 and the ODL application of SGML specified in other parts of ISO/IEC 8613. These include: + - 1) ISO/IEC 8613-5; + - 2) ISO/IEC 8613-6; + - 3) ISO/IEC 8613-7; + - 4) ISO/IEC 8613-8. + +The use of SGML and ODL is applicable to ISO/IEC 8613 only. + +### G.3.2 Document profile, structure and content conformance + +Document profile, structure and content conformance is determined by verifying that the constituents and attributes represented in the data stream conform to the rules specified in other specifications of the ITU-T Rec. T.410-Series | ISO/IEC 8613. These include: + +- ITU-T Rec. T.412 | ISO/IEC 8613-2; +- ITU-T Rec. T.414 | ISO/IEC 8613-4; +- ITU-T Rec. T.416 | ISO/IEC 8613-6; +- ITU-T Rec. T.417 | ISO/IEC 8613-7; +- ITU-T Rec. T.418 | ISO/IEC 8613-8. + +Document profile, structure and content conformance should be verified against the Formal Specification of ODA specified in ISO/IEC 8613-10. These include: + +- ISO/IEC 8613-2; +- ISO/IEC 8613-4; +- ISO/IEC 8613-6; +- ISO/IEC 8613-7; +- ISO/IEC 8613-8. + +The use of ISO/IEC 8613-10 is applicable to ISO/IEC 8613 only. + +### G.3.3 Document application profile n (DAP-n) conformance + +If applicable, document application profile n (DAP-n) conformance is determined by verifying that the constituents and attributes conform to any additional constraints specified in a particular document application profile DAP-n defined in accordance with the rules specified in the DAP Proforma and Notation in Annex F. + +### G.3.4 Test results + +If no errors are present in the test results from the data stream analysis, output must be produced which declares that the data stream under test is in conformance with the ITU-T Rec. T.410-Series | ISO/IEC 8613. If any of the test results indicate that an error exists in the data stream, then output must be produced which declares that the data stream under test is not in conformance with the ITU-T Rec. T.410-Series | ISO/IEC 8613. This output should provide information to identify the component of the data stream that contained the error and the nature of the error in the data stream. \ No newline at end of file diff --git a/marked/T/T-REC-T.413-199411-I_PDF-E/raw.md b/marked/T/T-REC-T.413-199411-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..688c275f479def2aeca20edbc67de26c6d06ebcb --- /dev/null +++ b/marked/T/T-REC-T.413-199411-I_PDF-E/raw.md @@ -0,0 +1,1334 @@ + + +![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU and a lightning bolt symbol. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## T.413 + +(11/94) + +### TERMINALS FOR TELEMATIC SERVICES + +--- + +**INFORMATION TECHNOLOGY – OPEN +DOCUMENT ARCHITECTURE (ODA) +AND INTERCHANGE FORMAT: ABSTRACT +INTERFACE FOR THE MANIPULATION OF +ODA DOCUMENTS** + +### ITU-T Recommendation T.413 + +(Previously “CCITT Recommendation”) + +--- + +# Foreword + +ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. Some 179 member countries, 84 telecom operating entities, 145 scientific and industrial organizations and 38 international organizations participate in ITU-T which is the body which sets world telecommunications standards (Recommendations). + +The approval of Recommendations by the Members of ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, 1993). In addition, the World Telecommunication Standardization Conference (WTSC), which meets every four years, approves Recommendations submitted to it and establishes the study programme for the following period. + +In some areas of information technology, which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. The text of ITU-T Recommendation T.413 was approved on 11th of November 1994. The identical text is also published as ISO/IEC International Standard 8613-3. + +# --- NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +© ITU 1995 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +# CONTENTS + +| | <i>Page</i> | +|--------------------------------------------------------------------------------------------|-------------| +| Summary..... | iii | +| Foreword ..... | iv | +| 1 Scope..... | 1 | +| 2 Normative references ..... | 1 | +| 2.1 Identical Recommendations International Standards ..... | 2 | +| 2.2 Paired Recommendations International Standards equivalent in technical content ..... | 2 | +| 2.3 Additional references ..... | 2 | +| 3 Definitions..... | 3 | +| 4 Abbreviations ..... | 3 | +| 5 Conventions..... | 3 | +| 6 Purpose..... | 3 | +| 6.1 Concept of the Abstract Interface ..... | 3 | +| 6.2 Relationship to functional profiles ..... | 4 | +| 6.3 Identification ..... | 4 | +| 6.4 Consistent handling of ODA documents ..... | 4 | +| 6.5 Relationship between operations ..... | 4 | +| 6.6 Grouping of operations ..... | 5 | +| 6.7 Relationship to communication aspects ..... | 5 | +| 7 Operations on ODA documents ..... | 5 | +| 7.1 Document level operations..... | 6 | +| 7.1.1 List ..... | 6 | +| 7.1.2 Open..... | 7 | +| 7.1.3 Close ..... | 7 | +| 7.2 Read only operations..... | 8 | +| 7.2.1 Get..... | 8 | +| 7.2.2 Search..... | 8 | +| 7.3 Altering operations..... | 9 | +| 7.3.1 Create ..... | 9 | +| 7.3.2 Delete ..... | 10 | +| 7.3.3 Modify ..... | 10 | +| 7.3.4 Replace..... | 11 | +| 7.3.5 Copy..... | 11 | +| 7.3.6 Move ..... | 12 | +| 7.4 Reservation operations ..... | 13 | +| 7.4.1 Reserve..... | 13 | +| 7.4.2 Unreserve ..... | 13 | +| 7.5 ODA-independent operations ..... | 14 | +| 7.5.1 BeginGroup..... | 14 | +| 7.5.2 EndGroup..... | 14 | +| 8 ASN.1 specification of the abstract operations ..... | 14 | +| Annex A – Alignment with DTAM document Manipulation abstract service ..... | 18 | +| A.1 Introduction..... | 18 | +| A.2 Description of the mapping to DTAM-DM abstract service..... | 18 | +| Annex B – Alignment with DOAM set of operations ..... | 20 | + +# LIST OF TABLES + +| | <i>Page</i> | +|------------------------------------------------------------------------------------------|-------------| +| Table A.1 – Mapping of arguments between Abstract Interface and DTAM-DM operations ..... | 19 | +| Table B.1 – Alignment of operations between Abstract Interface and DOAM..... | 20 | + +# Summary + +This Recommendation | International Standard describes an abstract interface that supports manipulation of ODA documents and the functions that are applicable to document fragments in order to facilitate the handling of ODA documents and to support applications + +# Foreword + +This ITU-T Recommendation | International Standard was prepared as a joint publication by ITU-T Study Group 8 and ISO/IEC Joint Technical Committee 1. + +At present, the ITU-T Recommendations in the T.410-Series | International Standard ISO/IEC 8613 consists of: + +- Introduction and general principles; +- Document structures; +- Abstract interface for the manipulation of ODA documents; +- Document profile; +- Open document interchange format; +- Character content architectures; +- Raster graphics content architectures; +- Geometric graphics content architectures; +- Audio content architectures; +- Formal specification of the Open Document Architecture (FODA) +(The formal specification is applicable to ISO/IEC 8613 only.) +- Tabular structures and tabular layout; +- Identification of document fragments; +- Temporal relationships and non-linear structures. + +Further Recommendations | International Standards may be added to this series of ITU-T Recommendations | International Standards. + +Development of this series of ITU-T Recommendations | International Standards was originally in parallel with ECMA-101 standard: *Open Document Architecture*. + +This ITU-T Recommendation | International Standard contains two annexes: + +- Annex A (integral) specifies the alignment with DTAM abstract service; +- Annex B (non-integral) specifies the alignment with DOAM set of operations. + +###### **INTERNATIONAL STANDARD** + +###### **ITU-T RECOMMENDATION** + +###### **INFORMATION TECHNOLOGY – OPEN DOCUMENT ARCHITECTURE (ODA) AND INTERCHANGE FORMAT: ABSTRACT INTERFACE FOR THE MANIPULATION OF ODA DOCUMENTS** + +# **1 Scope** + +The purpose of ITU-T Rec. T.410-Series | ISO/IEC 8613 is to facilitate the interchange and manipulation of documents. + +In the context of these Recommendations | International Standards, documents are considered to be items such as memoranda, letters, invoices, forms and reports, which may include pictures and tabular material. The content elements used within the documents may include graphic characters, raster graphics elements and geometric graphics element, all potentially within one document. + +NOTE – These Recommendations | International Standards are designed to allow for extensions, including spreadsheets and additional types of content such as video. + +In addition to the content types defined in these Recommendations | International Standards, ODA also provides for arbitrary content types to be included in documents. + +These Recommendations | International Standards apply to the interchange of documents by means of data communications or the exchange of storage media. + +These Recommendations | International Standards provide for the interchange of documents for either or both of the following purposes: + +- to allow presentation as intended by the originator; +- to allow processing, such as editing and reformatting. + +The composition of a document in interchange can take several forms: + +- formatted form, allowing presentation of the document; +- processable form, allowing processing of the document; +- formatted processable form, allowing both presentation and processing of the document. + +These Recommendations | International Standards also provide for the interchange of ODA information structures used for the processing of interchanged documents. + +This Recommendation | International Standard: + +- describes an Abstract Interface that supports manipulation of ODA documents; +- defines the operations that are applicable to document fragments in order to facilitate the handling of ODA documents, and to support applications. + +# **2 Normative references** + +The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T/CCITT Recommendations. + +## 2.1 Identical Recommendations | International Standards + +- ITU-T Recommendation T.411 (1993) | ISO/IEC 8613-1:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Introduction and general principles.* +- ITU-T Recommendation T.412 (1993) | ISO/IEC 8613-2:1995, *Information technology – Open Document Architecture (ODA) and interchange format: Document structures.* +- ITU-T Recommendation T.414 (1993) | ISO/IEC 8613-4:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Document profile.* +- ITU-T Recommendation T.415 (1993) | ISO/IEC 8613-5:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Open document interchange format.* +- ITU-T Recommendation T.416 (1993) | ISO/IEC 8613-6:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Character content architectures.* +- ITU-T Recommendation T.417 (1993) | ISO/IEC 8613-7:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Raster graphics content architectures.* +- ITU-T Recommendation T.418 (1993) | ISO/IEC 8613-8:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Geometric graphics content architectures.* +- ITU-T Recommendation T.419<sup>1)</sup> | ISO/IEC 8613-9: ...<sup>1)</sup>, *Information technology – Open Document Architecture (ODA) and interchange format: Audio content architectures.* +- ITU-T Recommendation T.421 (1994) | ISO/IEC 8613-11:1995, *Information technology – Open Document Architecture (ODA) and interchange format: Tabular structures and tabular layout.* +- ITU-T Recommendation T.422<sup>1)</sup> | ISO/IEC 8613-12: ...<sup>1)</sup>, *Information technology – Open Document Architecture (ODA) and interchange format: Identification of document fragments.* +- ITU-T Recommendation T.424<sup>1)</sup> | ISO/IEC 8613-14: ...<sup>1)</sup>, *Information technology – Open Document Architecture (ODA) and interchange format: Temporal relationships and non-linear structures.* + +## 2.2 Paired Recommendations | International Standards equivalent in technical content + +- CCITT Recommendation X.208 (1988), *Specification of Abstract Syntax Notation One (ASN.1).* +ISO/IEC 8824:1990, *Information technology – Open Systems Interconnection – Specification of Abstract Syntax Notation One (ASN.1).* +- CCITT X.400-Series Recommendations (1988), *Message Handling System.* +ISO/IEC 10021:1990, *Information technology – Text communication – Message Oriented Text Interchange Systems (MOTIS).* + +## 2.3 Additional references + +- CCITT Recommendation T.431 (1991), *Document Transfer and Manipulation (DTAM) – Services and protocols - Introduction and general principles.* +- CCITT Recommendation T.432 (1991), *Document Transfer and Manipulation (DTAM) – Services and protocols - Service definition.* +- CCITT Recommendation T.433 (1991), *Document Transfer and Manipulation (DTAM) – Services and protocols - Protocol specification.* +- ITU-T Recommendation T.435 (1995), *Document Transfer and Manipulation (DTAM) – Services and protocols – Abstract service definition and procedures for confirmed document manipulation.* +- ITU-T Recommendation T.436 (1995), *Document Transfer and Manipulation (DTAM) – Services and protocols – Protocol specifications for confirmed document manipulation.* +- ISO/IEC 8613-10:1991, *Information processing – Text and office systems – Office Document Architecture (ODA) and interchange format – Part 10: Formal specifications.* +- ISO/IEC 10031-1:1991, *Information technology – Text and office systems – Distributed-office-applications model – Part 1: General model.* +- ISO/IEC 10166-1 (1991), *Information technology – Text and office systems – Document Filing and Retrieval (DFR) – Part 1: Abstract service definition and procedures.* + +--- + +<sup>1)</sup> Presently at the stage of draft. + +# 3 Definitions + +For the purposes of this Recommendation | International Standard, the definitions given in ITU-T Rec. T.411 | ISO/IEC 8613-1 and ITU-T Rec. T.422 | ISO/IEC 8613-12 apply. + +The following additional definitions are used within this Recommendation | International Standard: + +- 3.1 basic operation:** An operation that could not consist of a sequence of other operations without a clear loss of efficiency. +- 3.2 compound operation:** An operation that could be substituted by a sequence of other operations. +- 3.3 document identifier:** An identification of an ODA document that may be permanent (the “document reference” document profile attribute) or not (an integer value). +- 3.4 query:** A logical expression comprising logical operators that connect values of attributes. + +# 4 Abbreviations + +For the purposes of this Recommendation | International Standard, the abbreviations given in ITU-T Rec. T.411 | ISO/IEC 8613-1 apply. + +The following additional abbreviations are used within this Recommendation | International Standard: + +| | | +|---------|------------------------------------------------------------| +| AGCS | Audio Graphics Conferencing Service | +| AVIS | Audio Visual Interactive Service | +| CDH | Cooperative Document Handling | +| DAP | Document Application Profile | +| DFR | Document Filing and Retrieval | +| DOAM | Distributed Office Applications Model | +| DTAM | Document Transfer And Manipulation | +| DTAM-DM | Document Transfer And Manipulation - Document Manipulation | +| ROSE | Remote Operations Service Element | + +# 5 Conventions + +For the purposes of this Recommendation | International Standard, the conventions given in ITU-T Rec. T.411 | ISO/IEC 8613-1 and ITU-T Rec. T.412 | ISO/IEC 8613-2 apply. + +# 6 Purpose + +## 6.1 Concept of the Abstract Interface + +Documents may be edited, formatted, imaged, manipulated, and stored locally or in an open environment. The Abstract Interface applies to those aspects of manipulation that may be defined in an open environment. Nevertheless, it may be up to a specific implementation to provide interfaces in a compatible way for the open and the local environments. + +Although the Abstract Interface defines functions to handle ODA documents, it does not preclude any definition of any specific application, but the applications themselves are responsible for the proper use of the operations provided by the Abstract Interface. + +The objectives of the Abstract Interface are summarized in the following list of functions: + +- Ensure consistency of manipulated ODA documents. +- Facilitate distributed processing of ODA documents. The Abstract Interface hides distribution details. Furthermore, local integration of products from different vendors can be achieved by using the Abstract Interface. +- Enable the defined operations to be mapped onto existing services, such as Document Transfer And Manipulation (DTAM). + +- Facilitate the integration of a variety of applications that manipulate ODA documents. The applications can be designed and interfaced at a higher level of abstraction. +- Present the user a simple conceptual model of a complex ODA document. + +The operations that are defined in the Abstract Interface are specified on a general level to support document manipulation in the context of various types of applications, such as: + +- Reading and manipulation of fragments of a document. +- Simple conferencing, where two or more users possess identical copies of a document and are exchanging updates on document fragments in terms of operations. +- Audio Graphics Conferencing Service (AGCS). +- Remote editing, where one or more users have a complete or partial view of a document. The document is read and updated by exchanging operations. +- Cooperative Document Handling (CDH), where several partners handle ODA documents in a distributed environment. +- Videotex Interworking, for compatibility with ITU-T applications. +- AudioVisual Interactive Service (AVIS). +- ODA document processing applications development, including word processors and desktop publishing systems. +- Asynchronous distributed document handling. + +## 6.2 Relationship to functional profiles + +For document manipulation, specific functional profiles or amendments to existing ones may be defined to specify: + +- which operations may be used; +- which operations may be applied to which type of constituents; +- which sets of constituents shall be carried together by one operation; +- which rules have to be followed to guarantee consistency of the document; +- how the grouping of operations shall be used; +- how the reserving of constituents of a document shall be realized. + +## 6.3 Identification + +In the Abstract Interface for the manipulation of ODA documents, the mechanism for identifying document fragments, to be used as arguments to the manipulation operations, is based on the use of location expressions, according to ITU-T Rec. T.422 | ISO/IEC 8613-12. + +## 6.4 Consistent handling of ODA documents + +It is a basic requirement of the manipulation of ODA documents that consistency of the documents being manipulated is guaranteed. After successful manipulation and closing of a document, it shall be a conformant ODA document and it shall conform to the Document Application Profile (DAP) specified in the document profile, if any. + +The Abstract Interface defines some general rules to describe the effect that the different operations have on the documents. The implementations of the Abstract Interface shall guarantee the consistency of the documents. To help in this task, BeginGroup and EndGroup operations are provided, that could be used to indicate that the manipulated document has to be updated in order to achieve the required consistency. + +## 6.5 Relationship between operations + +The List operation applies to the document store, and it is used to select one or more documents for further manipulation. + +The Open operation identifies a document which is to be handled. Several documents may be opened at the same time (e.g. for copying a document fragment from one document to another). There is a Close operation to complement the Open operation. + +Before issuing any read only, altering, or reservation operation (see clause 7), the Open operation shall be issued. The Open operation also allows to create a completely new document. + +A Reserve operation (and a complementary Unreserve operation) is provided to handle the possible concurrent manipulation of a document fragment. If a document fragment is manipulated without a previous use of the Reserve operation, the result may be unpredictable if other users have access to that document fragment. + +Read only and altering operations may be issued without any particular order restriction, apart from those given in this subclause. + +The use of all the operations is explained in the corresponding subclauses of clause 7. + +## 6.6 Grouping of operations + +A mechanism for grouping a sequence of operations is provided by the Abstract Interface. + +The application shall be responsible for the correct use of this feature and shall define the meaning of the grouping of operations. + +The main objective of this mechanism is to group operations with some meaning for the application that is using the Abstract Interface, in order to: + +- avoid communications overhead; +- ease the handling of consistency, including the provision of recovery procedures applied to a group of operations. + +This mechanism is provided by BeginGroup and EndGroup operations (see 7.5.1 and 7.5.2), that allow grouping to be performed during operations invocation. + +## 6.7 Relationship to communication aspects + +The Abstract Interface is independent of the communication mechanism. However, it is aligned with the communication support for access and manipulation provided by DTAM, as explained in Annex A. + +In the context of interactive handling, three aspects are distinguished: + +- the access to an ODA document; +- the inner manipulation of an accessed ODA document; +- the communication environment supporting access and manipulation. + +In the case that the Abstract Interface is used by communication applications, specific communication application profiles, or functional profiles, may be specified to: + +- transfer manipulations of ODA documents in an appropriate way; +- negotiate the application environment; +- negotiate the capabilities of the user system. + +NOTE – Rules for specifying communication application profiles are defined, for example, in CCITT Recommendation T.431. + +# 7 Operations on ODA documents + +This clause specifies the operations that constitute the Abstract Interface to support the manipulation of documents. + +The operations are specified as abstract operations in terms of: + +- argument(s); +- result(s); +- error(s). + +Operations are applied to the constituents of the document architecture. + +Five kinds of operations are distinguished by the Abstract Interface: + +- document level operations; +- read only operations; +- altering operations; +- reservation operations; +- ODA-independent operations. + +Furthermore, operations are classified as: + +- *basic operations*; +- *compound operations*. + +Compound operations can be performed as a sequence of basic operations. + +The operations defined by the Abstract Interface are aligned with those defined in ISO/IEC 10031-1 Distributed Office Applications Model (DOAM), as explained in Annex B. + +Some errors are defined that apply to several operations. These are: + +- *Error in the constituents* – The constituent or constituents of the argument are not valid. +- *Invalid location expression or document* – The document or the location expression used as arguments are invalid. +- *Location expression does not match* – The location expression of the argument does not match. +- *Document fragments reserved (source region reserved, target region reserved)* – The location expression of the argument contains reserved constituents. For some operations which work with two documents, this error is referred to as “source region reserved” (for the origin document) and “target region reserved” (for the destination document). +- *Invalid document identifier* – The document identifier of the argument is not valid. +- *Document does not exist* – The document that is intended to be opened or closed does not exist. +- *Improper access rights* – The requestor of the operation does not have the necessary access rights to perform the operation. +- *Document is not open* – A manipulation operation is requested onto a document that has not been previously open using the Open operation. +- *Unspecified error* – An error has occurred that is not specified. + +## 7.1 Document level operations + +### 7.1.1 List + +The List abstract operation obtains a list of ODA documents, matching particular criteria, in a document store. This operation is independent of the structure of the store. If the store has a standard structure, like, for example, that specified in ISO/IEC 10166 Document Filing and Retrieval (DFR), selection of documents may be achieved using DFR operations. + +The selection criteria are expressed in a *query* that consists of a logical expression comprising ‘not’, ‘and’ and ‘or’ logical operators that connect values of document profile management attributes. In this way, for example, documents with specific values in one or more attributes can be selected. + +If the “query” argument is not provided, then all documents from the store are listed. + +(Identifiers of) complete documents are selected with the List operation. For selecting (identifiers of) document constituents the Search operation (see 7.2.2) shall be used. + +Possible errors specific for this operation are: + +- *Invalid query* – The query of the argument is not valid. +- *Query does not match* – The query of the argument does not match with any document. + +This is a basic operation. + +*Argument:* query. (optional) + +*Result:* sequence of document identifiers. + +*Errors:* invalid query; +query does not match; +improper access rights; +unspecified error. + +### 7.1.2 Open + +The Open abstract operation selects a particular document in order to make further manipulations on fragments of it. The document identifier used as the argument may be obtained from a previous use of the List operation. + +Several documents may be maintained open at the same time. This shall be achieved by issuing several Open operations before closing all open documents. + +An Open operation is always necessary before inner manipulation of a document. + +A complete document is selected with the Open operation. The Reserve operation (see 7.4.1) is used to select and reserve a fragment of a document already open. + +The “document identifier” argument shall be a permanent identifier (the “document reference” attribute of the document profile). The “mode” optional argument may have three values: ‘read’, ‘modify’ and ‘create’. If a document is open with “mode” equal to ‘read’, it will only be possible to perform read operations on it. In case it is open with “mode” equal to ‘modify’, it will be possible to apply all manipulation operations. Finally, with the ‘create’ value, it means that the document is to be created. In this latter case, the permanent identifier is the identification to be given to the document. + +The “document identifier” result is a non-permanent (temporary) identifier of the document (as an integer value) that is provided when opening a document. + +A possible error specific for this operation is: + +- *Document already open* – This error is used when there is an attempt to open an already open document. + +This is a basic operation. + +| | | | +|-------------------|-------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------| +| <i>Arguments:</i> | document identifier;<br>mode. | <i>(permanent identifier)</i><br><i>(optional)</i> | +| <i>Result:</i> | document identifier. | <i>(non-permanent identifier)</i> | +| <i>Errors:</i> | invalid document identifier;<br>document does not exist;<br>improper access rights;<br>document already open;<br>unspecified error. | | + +### 7.1.3 Close + +The Close abstract operation is used to finish the manipulation process of a document. The document identifier used as the argument has to correspond to an already open document. No argument is needed if only one document is open. + +When the application wants to close a document, the document could be inconsistent if altering operations (see 7.3) have been applied to the document. In this case, and to avoid closing a non-conformant document, the document is implicitly updated. + +Furthermore, when closing a document, all reserved document fragments are implicitly unreserved (see 7.4.1 and 7.4.2). + +The “document identifier” result is the permanent identifier of the document (the “document reference” attribute of the document profile), that is provided when closing the document. + +Possible errors specific for this operation are: + +- *Document impossible to update* – There is a problem in the document to be closed that makes the document impossible to update. +- *Groups not yet ended* – Some BeginGroup operations still need EndGroup operations to be issued. + +This is a basic operation. + +| | | | +|------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------| +| <i>Argument:</i> | document identifier. | <i>(optional)</i> | +| <i>Result:</i> | document identifier. | <i>(permanent identifier)</i> | +| <i>Errors:</i> | invalid document identifier;<br>improper access rights;<br>document is not open;<br>document impossible to update;<br>groups not yet ended;<br>unspecified error. | | + +## 7.2 Read only operations + +### 7.2.1 Get + +The Get operation is used to request one or more constituents of the ODA document. In the case of more than one constituent, the result can be one or more subtrees. + +The Get operation returns the relevant constituents, identified by the “location expression” argument, with all their attributes. The “no-defaults” argument determines whether or not defaulted values are returned. If this argument is not provided, defaulted attributes are returned. + +The “document identifier” argument is not needed if only one document is open. + +The location expression used as argument may be a constituent identifier obtained from a previous use of the Search operation (see 7.2.2). + +This is a basic operation. + +*Arguments:* document identifier; (optional) +location expression; +no-defaults. (optional) + +*Result:* one or more constituent descriptions. + +*Errors:* invalid location expression or document; +location expression does not match; +document fragments reserved; +improper access rights; +document is not open; +unspecified error. + +### 7.2.2 Search + +The Search abstract operation looks for the information specified in the location expression of the argument, that may be: + +- structure information; +- content portions information (the way this information is searched for depends on the content architecture in use); +- structure and content information. + +The result of the Search operation is the sequence of identifiers matching the search criteria specified in the “location expression” argument. + +The number of occurrences of the target information that are returned may be limited with the “maximum number of occurrences” argument. If this argument is not provided, then all occurrences are returned. In any case, the number of returned occurrences is given in the result. + +The “document identifier” argument is not needed if only one document is open. + +The Search and Get operations may each return more than one constituent. The difference is that the Search operation returns only constituent identifiers, while the Get operation returns complete constituents. + +NOTE 1 – A normal use of the Search operation is before a Get operation to select the constituent or constituents that are required. + +The difference between the Search and List operations is that the former applies to one document and returns constituent identifiers, while the latter applies to a set of documents and returns document identifiers. + +This is a basic operation. + +*Arguments:* document identifier; (optional) +location expression; +maximum number of occurrences. (optional) + +*Results:* identification of all the objects where the target information was found, up to the specified maximum; +the number of occurrences of the specified information. + +*Errors:* invalid location expression or document; +location expression does not match; +document fragments reserved; + +improper access rights; +document is not open; +unspecified error. + +NOTE 2 – Following is an example of the use of the Search operation. + +A location expression (see ITU-T Rec. T.422 | ISO/IEC 8613-12) that could be used as an argument to a Search operation to get the identifiers of all footnotes in a document conforming to ISO/IEC ISP 11181-1 would be: + +``` +OBJECT-WITH (attribute-name = "application-comments", + value-specification = "$Footnote", + object-locator = "3" -- document logical root--, + ( , end-counter = 0), + defaulting = true) +``` + +where "\$Footnote" stands for the value that ISO/IEC ISP 11181-1 mandates for the attribute "application-comments" of those constituents representing footnotes. + +The result would be a list of identifiers, looking like (see ASN.1 specification in clause 8): + +``` +SearchResult = + constituentList = -- In the case of the Search operation, "ConstituentType" includes identifiers only. + ConstituentType = "3 2 0 1" + ConstituentType = "3 4 5 1" + numberOfOccurrences = 2 +``` + +## 7.3 Altering operations + +### 7.3.1 Create + +The Create abstract operation effects the creation and insertion of a new constituent or several new constituents (in the case of objects in the form of a subtree) into the document. + +It is necessary to specify the constituents to be created and (except for root objects, styles and classes) the place where they are to be included (a location expression) and also the relative position of the new constituent(s) with respect to the constituent obtained from the location expression. + +The place to include the created constituents shall be indicated by a constituent location, i.e. a location expression that (as specified in ITU-T Rec. T.422 | ISO/IEC 8613-12) selects a simple constituent. + +Two options are provided for the relative position, that include all possible cases: *before* the identified constituent, or *after last child* of the identified constituent. + +The “document identifier” argument is not needed if only one document is open. + +If a constituent or a subtree is successfully created (the document is still complete, and, in the case of objects, the generic structure remains consistent), a value is automatically assigned to its “identifier” attribute (or to the “identifier” attribute of all the constituents of the subtree). The “identifier” attribute of the constituent (or of the root of the subtree) is returned in the “constituent identifier” result. When objects (other than the root) and content portions are created, the “subordinates” or “content portions” attribute of the superior of the constituent (or of the root of the subtree) is updated. + +This is a basic operation. + +| | | | +|-------------------|---------------------------------------|-----------------------------------------| +| <i>Arguments:</i> | one or more constituent descriptions; | | +| | document identifier: | <i>(optional)</i> | +| | constituent location; | <i>(only for objects, except roots)</i> | +| | position (before, after last child). | <i>(optional)</i> | + +*Result:* constituent identifier. + +*Errors:* + +- error in the constituents; +- invalid location expression or document; +- location expression does not match; +- document fragments reserved; +- improper access rights; +- document is not open; +- unspecified error. + +### 7.3.2 Delete + +The Delete abstract operation causes the deletion of one or more constituents of the ODA document, identified by the “location expression” argument, and implies the deletion of all constituents that are subordinate to the identified constituent(s). In the case of objects (other than the root) and content portions, the “subordinates” or “content portions” attribute of the superior is updated. + +The “document identifier” argument is not needed if only one document is open. + +The location expression used as argument may be a constituent identifier obtained from a previous use of the Search operation. + +This is a basic operation. + +*Arguments:* document identifier; (optional) +location expression. + +*Result:* success or failure. + +*Errors:* invalid location expression or document; +location expression does not match; +document fragments reserved; +improper access rights; +document is not open; +unspecified error. + +### 7.3.3 Modify + +The Modify abstract operation assigns new values to attributes of the identified (by the “location expression” argument), already existing, constituents. + +Attributes that are not mentioned as a parameter of the Modify operation retain their previous values, unless the optional argument “deleting” is set to ‘true’; in this case, optional attributes not included in the argument “attribute values” are deleted. This is the way of deleting attributes with the Modify operation. + +Optional attributes, that have not been present in the identified constituent, may be added to the relevant constituent by use of the Modify operation. This is the way of adding new attributes with the Modify operation. + +The “document identifier” argument is not needed if only one document is open. + +Identification attributes, if present, shall not be changed by the Modify abstract operation. The constituent “identifier” attributes and the “subordinates”, “object type” and “content portions” attributes shall not be modified. + +The location expression used as argument may be a constituent identifier obtained from a previous use of the Search operation. + +A possible error specific for this operation is: + +- *Error in the attributes* – The constituent or constituents, giving the attribute values, of the argument are wrong. + +This is a basic operation. + +*Arguments:* document identifier; (optional) +location expression; +attribute values; +deleting. (optional) + +*Result:* success or failure. + +*Errors:* error in the attributes; +invalid location expression or document; +location expression does not match; +document fragments reserved; +improper access rights; +document is not open; +unspecified error. + +### 7.3.4 Replace + +The Replace abstract operation effects the deletion of the identified constituent, including all subordinate constituents, and the replacement by one new constituent, which may have subordinate constituents, specified in the argument of the operation. + +The “document identifier” argument is not needed if only one document is open. + +Replace is a compound operation that is provided by the Abstract Interface for efficiency and compatibility reasons. The Replace abstract operation is equivalent to the application of the Delete and Create operations. + +*Arguments:* one or more constituent descriptions; +document identifier; *(optional)* +constituent location. *(only for objects, except roots)* + +*Result:* success or failure. + +*Errors:* error in the constituents; +invalid location expression or document; +location expression does not match; +document fragments reserved; +improper access rights; +document is not open; +unspecified error. + +### 7.3.5 Copy + +The Copy abstract operation duplicates one constituent or several constituents (in the case of objects in the form of a subtree) of an ODA document in another location in the same document or in a different document. + +It is necessary to specify the constituents to be copied and (except for root objects, styles and classes) the place where they are to be copied (a target location expression) and also the relative position of the new constituent(s) with respect to the constituent obtained from the target location expression. + +For the “position” argument, the same options as for the Create operation (see 7.3.1) are provided. + +The place to include the copied constituents shall be indicated by a constituent location, as for the Create operation (see 7.3.1). + +The document identifier arguments are not needed if only one document is open. + +If a constituent or a subtree is successfully copied (the document is still complete, and, in the case of objects, the generic structure remains consistent), a value is automatically assigned to the “identifier” attribute of the target constituent (or of all the constituents of the target subtree). The “identifier” attribute of the target constituent (or of the root of the target subtree) is returned in the “constituent identifier” result. When objects (other than the root) and content portions are copied, the “subordinates” or “content portions” attribute of the superior of the target constituent (or of the root of the target subtree) is updated. + +Copy is provided as a basic operation for efficiency reasons. + +*Arguments:* source document identifier; *(optional)* +source basic location expression; +target document identifier; *(optional)* +target constituent location; *(only for objects, except roots)* +position (before, after last child). *(optional)* + +*Result:* constituent identifier. + +*Errors:* invalid source location expression or document; + invalid target location expression or document; + source location expression does not match; + target location expression does not match; + source region reserved; + target region reserved; + improper access rights; + source document is not open; + target document is not open; + unspecified error. + +### 7.3.6 Move + +The Move abstract operation changes the position of one constituent or several constituents (in the case of objects in the form of a subtree) inside an ODA document, or moves constituents from one document to another. + +It is necessary to specify the constituents to be moved and (except for root objects, styles and classes) the place where they are to be moved (a target location expression) and also the relative position of the new constituent(s) with respect to the constituent obtained from the target location expression. + +For the “position” argument, the same options as for the Create operation (see 7.3.1) are provided. + +The place to include the moved constituents shall be indicated by a constituent location, as for the Create operation (see 7.3.1). + +The document identifier arguments are not needed if only one document is open. + +If a constituent or a subtree is successfully moved to a new place in the document (the document is still complete, and, in the case of objects, the generic structure remains consistent), a value is automatically assigned to its “identifier” attribute (or to the “identifier” attribute of all the constituents of the subtree). The “identifier” attribute of the constituent (or of the root of the subtree) is returned in the “constituent identifier” result. When objects (other than the root) and content portions are moved, the “subordinates” or “content portions” attribute of the new superior of the constituent (or of the root of the subtree) is updated. + +When the moved constituent(s) are objects (other than the root) and content portions, the “subordinates” or “content portions” attribute of the superior of the constituent (or of the root of the subtree), before moving, is updated. + +This is a compound operation that is provided by the Abstract Interface for efficiency and compatibility reasons. This operation is, in general, equivalent to a pair of Copy and Delete operations. + +| | | | +|-------------------|--------------------------------------|-----------------------------------------| +| <i>Arguments:</i> | source document identifier; | <i>(optional)</i> | +| | source basic location expression; | | +| | target document identifier; | <i>(optional)</i> | +| | target constituent location; | <i>(only for objects, except roots)</i> | +| | position (before, after last child). | <i>(optional)</i> | + +*Result:* constituent identifier. + +*Errors:* invalid source location expression or document; + invalid target location expression or document; + source location expression does not match; + target location expression does not match; + source region reserved; + target region reserved; + improper access rights; + source document is not open; + target document is not open; + unspecified error. + +## 7.4 Reservation operations + +### 7.4.1 Reserve + +This operation, together with the Unreserve operation (see 7.4.2), is provided for multi-use of a document. + +The Reserve abstract operation causes the reservation, if possible, of one or more constituents (including all subordinate constituents), identified by the “location expression” argument, of the ODA document for further manipulation by the requesting user. + +With the Reserve operation, it is possible to select fragments of a document previously open with the Open operation. + +The “document identifier” argument is not needed if only one document is open. + +A “reservation identifier” result (as an integer value) is returned by this operation, that temporarily identifies the reserved location expression. + +Reserving of constituents of a document that have impact on, or are referenced by, other constituents may require a strategy to reserve also implicitly or explicitly the constituents that may be influenced by the subsequent manipulation. + +This is a basic operation. + +*Arguments:* document identifier; (optional) +location expression. + +*Result:* reservation identifier. + +*Errors:* invalid location expression or document; +location expression does not match; +document fragments reserved; +improper access rights; +document is not open; +unspecified error. + +### 7.4.2 Unreserve + +This operation, together with the Reserve operation (see 7.4.1), is provided for multi-use of a document. + +The Unreserve abstract operation causes the release of one or more constituents (including all subordinates), identified by the “location expression” argument, previously reserved by the Reserve operation. + +The “document identifier” argument is not needed if only one document is open. + +A “reservation identifier” argument may be used instead of a location expression. + +The Unreserve operation, like the Reserve operation, applies to document fragments, not to complete documents. + +The strategy followed by applications on reserving document fragments has to be coherent with the way of using the Unreserve operation. + +A possible error specific for this operation is: + +- *Constituents are not reserved* – This error is returned when trying to unreserve constituents not previously reserved. + +This is a basic operation. + +*Arguments:* document identifier; (optional) +location expression; (optional) +reservation identifier. (optional) + +*Result:* success or failure. + +*Errors:* invalid location expression or document; +location expression does not match; +improper access rights; +document is not open; +constituents are not reserved; +unspecified error. + +## 7.5 ODA-independent operations + +Two operations that are ODA-independent are provided. Both are related to grouping. + +BeginGroup and EndGroup operations (see 7.5.1 and 7.5.2) mark the beginning and end of a group of operations. They may be used for the following purposes: + +- informing a communication protocol that the selected group of operations (those between BeginGroup and EndGroup) could be communicated in one single interchange; +- informing a server (document store) that the selected group of operations (those between BeginGroup and EndGroup) have all to be processed at the same time. + +Nesting is allowed for mixing both kinds of groups of operations. + +### 7.5.1 BeginGroup + +The BeginGroup operation marks the beginning of a group of operations that have a special meaning for the application. + +This operation is always used in combination with the EndGroup operation (see 7.5.2). + +Groups of operations may be nested if allowed by the application. An invocation identifier is used to distinguish between different nested instances of the same group of operations, identified by the Operation group identifier. + +A possible error specific for this operation is: + +- *Invocation identifier duplicated* – An existing invocation identifier is being used. + +This is a basic operation. + +*Arguments:* operation group identifier; +invocation identifier. + +*Result:* success or failure. + +*Errors:* invocation identifier duplicated; +unspecified error. + +### 7.5.2 EndGroup + +The EndGroup operation marks the end of a previously initiated group of operations. + +This operation is always used in combination with the BeginGroup operation (see 7.5.1). + +A possible error specific for this operation is: + +- *No BeginGroup* – A previous BeginGroup operation has not been issued. + +This is a basic operation. + +*Arguments:* operation group identifier; +invocation identifier. + +*Result:* success or failure. + +*Errors:* no BeginGroup; +unspecified error. + +# 8 ASN.1 specification of the Abstract Operations + +In this clause, the arguments and results of the abstract operations defined in clause 7 are specified using ASN.1. The use of ASN.1 does not imply any encoding of the operations; such encoding is outside the scope of this Specification, and may be specified in other Recommendations | International Standards. + +NOTE – Rules for specifying how to encode operations are defined, for example, in ITU-T Recommendation T.435 DTAM Document Manipulation. + +###### ISO/IEC 8613-3 : 1995 (E) + +Abstract-Operations { 2 8 1 3 0 } + +DEFINITIONSIMPLICIT TAGS ::= BEGIN + +EXPORTS EVERYTHING; + +IMPORTS Location-expression, Basic-location-expression, Constituent-locator +FROM Location-Model { 2 8 1 12 0 } + +-- see ITU-T Rec. T.422 | ISO/IEC 8613-12 + +Document-Reference, Document-Profile-Descriptor +FROM Document-Profile-Descriptor { 2 8 1 5 6 } +-- see ITU-T Rec. T.415 | ISO/IEC 8613-5 + +Object-or-Class-Identifier, Content-Portion-Identifier, Style-Identifier +FROM Identifiers-and-Expressions { 2 8 1 5 7 } +-- see ITU-T Rec. T.415 | ISO/IEC 8613-5 + +Interchange-Data-Element +FROM Interchange-Data-Elements { 2 8 1 5 5 }; +-- see ITU-T Rec. T.415 | ISO/IEC 8613-5 + +-- COMMON DATA TYPES + +LocationInDocumentType ::= SEQUENCE { +document [0] Document-Id OPTIONAL, +location [1] Location-expression } + +BasicLocationInDocumentType ::= SEQUENCE { +document [0] Document-Id OPTIONAL, +basic-location [1] Basic-location-expression } + +ConstituentLocationInDocumentType ::= SEQUENCE { +document [0] Document-Id OPTIONAL, +constituent-location [1] Constituent-locator OPTIONAL } -- It is optional for styles and +-- root + +Document-Id ::= CHOICE { +permanent [0] Document-Reference, +non-permanent [1] INTEGER } + +ConstituentType ::= ManipulationDataElement + +ManipulationDataElement ::= Interchange-Data-Element + +SuccessType ::= BOOLEAN + +PositionType ::= ENUMERATED { +before (0), +afterLastChild (1) } + +ConstituentIdentifier ::= CHOICE { +object-or-class [0] Object-or-Class-Identifier, +content-portion [1] Content-Portion-Identifier, +style [2] Style-Identifier } + +-- ABSTRACT OPERATIONS ARGUMENTS AND RESULTS + +-- DOCUMENT LEVEL OPERATIONS + +-- List + +ListArgument ::= QueryType + +QueryType ::= CHOICE { +basic[0] Document-Profile-Descriptor, -- Some values of document profile attributes +not [1] QueryType, +and [2] SET OF QueryType, +or [3] SET OF QueryType } + +ListResult ::= SEQUENCE OF Document-Id -- Permanent identifiers + +-- Open + +OpenArgument ::= SEQUENCE { + +``` + + identifier [0] Document-Id, -- Permanent identifier + mode [1] ModeType OPTIONAL } + +ModeType ::= ENUMERATED { + read (0), + modify (1), + create (2) } + +OpenResult ::= Document-Id -- Non-permanent identifier + +-- Close + +CloseArgument ::= Document-Id + +CloseResult ::= Document-Id -- Permanent identifier + +-- READ ONLY OPERATIONS + +-- Get + +GetArgument ::= SEQUENCE { + location-in-document [0] LocationInDocumentType, + no-defaults [1] BOOLEAN DEFAULT FALSE } + +GetResult ::= SEQUENCE OF SEQUENCE OF ConstituentType + +-- Search + +SearchArgument ::= SEQUENCE { + location-in-document [0] LocationInDocumentType, + maxOccurrences [1] INTEGER OPTIONAL } + +SearchResult ::= SEQUENCE { + constituentList [0] SEQUENCE OF ConstituentIdentifier, + numberOfOccurrences [1] INTEGER } + +-- ALTERING OPERATIONS + +-- Create + +CreateArgument ::= SEQUENCE { + constituent-or-subtree [0] SEQUENCE OF ConstituentType, -- If the elements of this + -- sequence are objects, they + -- form a subtree + + location-in-document [1] ConstituentLocationInDocumentType OPTIONAL, + position [2] PositionType OPTIONAL } + +CreateResult ::= ConstituentIdentifier + +-- Delete + +DeleteArgument ::= LocationInDocumentType + +DeleteResult ::= SuccessType + +-- Modify + +ModifyArgument ::= SEQUENCE { + location-in-document [0] LocationInDocumentType, + attributeValue [1] AttributeValuesType, + deleting [2] BOOLEAN DEFAULT FALSE } + +AttributeValuesType ::= Interchange-Data-Element + +ModifyResult ::= SuccessType + +-- Replace + +``` + +``` + +ReplaceArgument ::= SEQUENCE { + constituent-or-subtree [0] SEQUENCE OF ConstituentType, + -- If the elements of this + -- sequence are objects, they + -- form a subtree + location-in-document [1] ConstituentLocationInDocumentType } + +``` + +ReplaceResult ::= SuccessType + +-- Copy + +``` + +CopyArgument ::= SEQUENCE { + source [0] BasicLocationInDocumentType, + target [1] ConstituentLocationInDocumentType, + position [2] PositionType OPTIONAL } + +``` + +CopyResult ::= ConstituentIdentifier + +-- Move + +``` + +MoveArgument ::= SEQUENCE { + source [0] BasicLocationInDocumentType, + target [1] ConstituentLocationInDocumentType, + position [2] PositionType OPTIONAL } + +``` + +MoveResult ::= ConstituentIdentifier + +-- OTHER OPERATIONS + +-- Reserve + +ReserveArgument ::= LocationInDocumentType + +ReserveResult ::= Reservation-Id + +Reservation-Id ::= INTEGER + +-- Unreserve + +``` + +UnreserveArgument ::= CHOICE { + location-in-document [0] LocationInDocumentType, + reservation [1] Reservation-Id } + +``` + +UnreserveResult ::= SuccessType + +-- BeginGroup + +``` + +BeginGroupArgument ::= SEQUENCE { + group-identifier [0] INTEGER, + invocation-identifier [1] INTEGER } + +``` + +BeginGroupResult ::= SuccessType + +-- EndGroup + +``` + +EndGroupArgument ::= SEQUENCE { + group-identifier [0] INTEGER, + invocation-identifier [1] INTEGER } + +``` + +EndGroupResult ::= SuccessType + +END + +# Annex A + +## Alignment with DTAM document manipulation abstract service + +(This annex forms an integral part of this Recommendation | International Standard) + +## A.1 Introduction + +The ODA Abstract Interface is intended (but not restricted) to be used in conjunction with other Recommendations | International Standards that facilitate the open interchange of the manipulations defined by this Specification. + +Even if, in some applications, operations may be transferred asynchronously as messages, or may be combined in a file, e.g. for a bulk-update of a document, the most typical way to use the Abstract Interface is the direct mapping to the DTAM Document Manipulation (DTAM-DM) abstract service, defined in ITU-T Recommendation T.435. + +## A.2 Description of the mapping to DTAM-DM abstract service + +The operations defined in this Specification are mapped to operations defined in ITU-T Recommendation T.435. + +This Specification defines the abstract operations that can be applied to a document. DTAM-DM provides the service to transfer these operations and defines the encoding of operations for the open interchange. Abstract Interface operations, arguments, results and errors are then mapped to DTAM-DM operations, arguments, results and errors. Furthermore, DTAM-DM specifies their encoding and how the Remote Operations Service Element (ROSE) shall be used. + +Each operation contained in the Abstract Interface has one corresponding operation in the DTAM-DM abstract service. Both operations have identical names, except that DTAM-DM operations are combined with the prefix DM- (e.g. the Create abstract operation of the Abstract Interface is mapped to the DM-CREATE of the DTAM-DM abstract service). There are few exceptions to this rule: + +- there are no equivalent operations to the DTAM-DM abstract operations Save, Discard, Point and Macro-Call; +- the Open, Close, List, Save and Discard operations have the DM-DOCUMENT- prefix because they apply to complete documents; +- in ITU-T Recommendation T.435 the BeginGroup and EndGroup operations (called DM-GROUP-BEGIN and DM-GROUP-END) are left for further study, as the DM-MACRO-CALL abstract service. + +DTAM-DM operations may apply to other document formats than ODA (including proprietary formats). For this reason, names of parameters contained in DTAM-DM operations may be more general than the corresponding names in the Abstract Interface. + +Table A.1 specifies the mapping of arguments from the Abstract Interface operations to the corresponding arguments of the DTAM-DM abstract service operations. + +Table A.1 – Mapping of arguments between Abstract Interface and DTAM-DM operations + +| Operation | ODA Abstract Interface | DTAM-DM abstract service | +|-----------|------------------------------------------------------------------------|----------------------------------------------------------------------| +| LIST | query | criteria | +| OPEN | document identifier<br>mode | document id<br>mode | +| CLOSE | document identifier | document id | +| GET | location in document, no-defaults | manipulation object | +| SEARCH | location in document,<br>maximum number of occurrences | manipulation object<br>limit | +| CREATE | constituent or subtree<br>location in document<br>position | content<br>manipulation object<br>position | +| DELETE | location in document | manipulation object | +| MODIFY | location in document<br>attribute values, deleting | manipulation object<br>modifications | +| REPLACE | constituent or subtree<br>location in document | object content<br>manipulation object | +| COPY | source location in document<br>target location in document<br>position | source manipulation object<br>target manipulation object<br>position | +| MOVE | source location in document<br>target location in document<br>position | source manipulation object<br>target manipulation object<br>position | +| RESERVE | location in document | manipulation object | +| UNRESERVE | location in document, reservation identifier | manipulation object | + +# Annex B + +## Alignment with DOAM set of operations + +(This annex does not form an integral part of this Recommendation | International Standard) + +ISO/IEC 10031-1 specifies in subclause 6.6 a standard set of abstract operations for Distributed Office Applications, and gives details of their functionality in Annex K. + +The set of operations defined in the Abstract Interface for the manipulation of ODA documents is aligned with the DOAM set, as shown in Table B.1. + +**Table B.1 – Alignment of operations between Abstract Interface and DOAM** + +| ODA Abstract Interface | DOAM | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------| +| List | List | +| Get | Read | +| Modify | Modify | +| Copy | Copy | +| Move | Move | +| Search | Search | +| Create | Create | +| Delete | Delete | +| Reserve | Reserve | +| – | Notify | +| – | Abandon | +| Open | – | +| Close | – | +| Replace | – | +| BeginGroup | – | +| EndGroup | – | +| NOTES<br>1 Get (ODA Abstract Interface) and Read (DOAM) is the only difference in name.<br>2 The ODA Abstract Interface Reserve operation is complemented by the Unreserve operation. | | + +# Index + +Abandon, 21 + after last child, **10** + AGCS, **3**; 4 + altering operation, 5; 6; 8; **10** + attribute values, **11** + Audio Graphics Conferencing Service, 3; 4 + AudioVisual Interactive Service, 3; 4 + AVIS, **3**; 4 + basic operation, **3**; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15 + before, **10** + BeginGroup, 5; 8; **14**; 15; 19; 21 + CDH, **3**; 4 + classes, 10; 12 + Close, 5; **8**; 19; 21 + compound operation, **3**; 6; 11; 13 + constituent, 10 + constituent identifier, 10; 11; 12 + constituent location, 10; 12 + constituents are not reserved, **14** + content architecture, 9 + content portions, 9; 10; 11; 12 + Cooperative Document Handling, 3; 4 + Copy, **12**; 13; 21 + Create, **10**; 11; 12; 19; 21 + create, **7** + DAP, **3**; 4 + defaulted attributes, 8 + defaulted values, 8 + Delete, **10**; 11; 13; 21 + deleting, **11** + DFR, **3**; 6 + Discard, 19 + Distributed Office Applications Model, 3; 6 + DM-DOCUMENT- prefix, 19 + DOAM, **3**; 6; 21 + document already open, **7** + Document Application Profile, 3; 4 + document constituents, **7** + +document does not exist, **6** + +Document Filing and Retrieval, 3; **6** + +document fragments, **14** + +document fragments reserved, **6** + +document identifier, **3**; 7; 8; 9; 10; 11; 12; 13; **14** + +document impossible to update, **8** + +document is not open, **6** + +document level operation, **6** + +document profile attribute, **3** + +document reference, 3; 7; **8** + +Document Transfer And Manipulation, 3; **4** + +Document Transfer And Manipulation - Document Manipulation, 3; **19** + +DTAM, **3**; 4; 5; **19** + +DTAM-DM, **3**; **19** + +EndGroup, 5; 8; 14; **15**; 19; **21** + +error in the attributes, **11** + +error in the constituents, **6** + +formatted form, **1** + +formatted processable form, **1** + +Get, **8**; 9; **21** + +grouping, **5** + +groups not yet ended, **8** + +identifier, 10; 11; **12** + +improper access rights, **6** + +invalid document identifier, **6** + +invalid location expression or document, **6** + +invalid query, **7** + +invocation identifier duplicated, **14** + +List, 5; **6**; 9; 19; **21** + +location expression, 8; 9; 10; 11; 13; **14** + +location expression does not match, **6** + +Macro-Call, **19** + +manipulation operation, **7** + +maximum number of occurrences, **9** + +mode, **7** + +Modify, **11**; **21** + +modify, **7** + +Move, **12**; **21** + +no BeginGroup, **15** + +###### ISO/IEC 8613-3 : 1995 (E) + +no-defaults, **8** +non-permanent identifier, **7** +Notify, **21** +object type, **11** +objects, **10; 12** +ODA-independent operation, **6; 14** +Open, **5; 7; 13; 19; 21** +operations, **6** +permanent identifier, **7; 8** +Point, **19** +position, **10; 12** +processable form, **1** +query, **3; 7** +query does not match, **7** +Read, **21** +read, **7** +read only operation, **5; 6; 8** +Remote Operations Service Element, **3; 19** +Replace, **11; 21** +reservation identifier, **13; 14** +reservation operation, **5; 6; 13** +Reserve, **5; 7; 13; 21** +root, **10; 12** +root objects, **10; 12** +ROSE, **3; 19** +Save, **19** +Search, **8; 9; 10; 11; 21** +source region reserved, **6** +structure, **9** +styles, **10; 12** +subordinates, **10; 11; 12** +target region reserved, **6** +Unreserve, **5; 13** +unspecified error, **6** \ No newline at end of file diff --git a/marked/T/T-REC-T.416-199303-I_PDF-E/raw.md b/marked/T/T-REC-T.416-199303-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..1eea7f21ab1aa4a39e05c1217ae9452496ee3327 --- /dev/null +++ b/marked/T/T-REC-T.416-199303-I_PDF-E/raw.md @@ -0,0 +1,3350 @@ + + +![ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## T.416 + +(03/93) + +**TELEMATIC SERVICES** + +**TERMINAL EQUIPMENTS AND PROTOCOLS +FOR TELEMATIC SERVICES** + +--- + +**INFORMATION TECHNOLOGY –** + +**OPEN DOCUMENT ARCHITECTURE (ODA) +AND INTERCHANGE FORMAT: +CHARACTER CONTENT ARCHITECTURES** + +**ITU-T Recommendation T.416** + +(Previously “CCITT Recommendation”) + +--- + +# Foreword + +ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. Some 179 member countries, 84 telecom operating entities, 145 scientific and industrial organizations and 38 international organizations participate in ITU-T which is the body which sets world telecommunications standards (Recommendations). + +The approval of Recommendations by the members of ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, 1993). In addition, the World Telecommunication Standardization Conference (WTSC), which meets every four years, approves Recommendations submitted to it and establishes the study programme for the following period. + +In some areas of information technology, which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. The text of ITU-T Recommendation T.416 was approved by the WTSC (Helsinki, March 1-12, 1993). The identical text is also published as ISO/IEC International Standard 8613-6. + +# --- NOTE + +1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector. + +In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms "CCITT, CCIR or IFRB" or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. + +2 In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# Contents + +| | <i>Page</i> | +|-------------------------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 Normative references..... | 2 | +| 2.1 Identical Recommendations International Standards..... | 2 | +| 2.2 Paired Recommendations International Standards equivalent in technical content..... | 2 | +| 2.3 Additional references ..... | 2 | +| 3 Definitions ..... | 2 | +| 4 Abbreviations ..... | 3 | +| 5 Conventions..... | 3 | +| 6 General principles..... | 3 | +| 6.1 Content architecture classes ..... | 3 | +| 6.2 Content ..... | 4 | +| 6.3 Presentation attributes ..... | 4 | +| 6.4 Control functions..... | 4 | +| 6.5 Graphic characters..... | 5 | +| 6.6 Space characters ..... | 5 | +| 6.7 Coding of content information ..... | 5 | +| 6.8 Internal structure ..... | 5 | +| 6.8.1 Formatted content..... | 5 | +| 6.8.2 Processable content ..... | 5 | +| 6.8.3 Formatted processable content ..... | 6 | +| 7 Character positioning..... | 6 | +| 7.1 Basic concepts ..... | 6 | +| 7.1.1 Character fonts ..... | 6 | +| 7.1.2 Directions ..... | 7 | +| 7.1.3 Character image model..... | 7 | +| 7.1.4 Character spacing ..... | 9 | +| 7.1.5 Active position ..... | 9 | +| 7.1.6 Positioning area ..... | 9 | +| 7.1.7 Line boxes ..... | 9 | +| 7.2 Positioning of character images within a line box..... | 10 | +| 7.2.1 Spacing between characters..... | 11 | +| 7.2.2 Alignment..... | 12 | +| 7.2.3 Tabulation..... | 12 | +| 7.2.4 Character ordering..... | 12 | +| 7.2.5 Parallel annotation ..... | 14 | +| 7.2.6 Subscript/superscript ..... | 15 | +| 7.2.7 Pairwise kerning ..... | 15 | +| 7.2.8 First line offset ..... | 15 | +| 7.2.9 Itemization..... | 15 | +| 7.3 Positioning of line boxes within a basic layout object ..... | 15 | +| 8 Character imaging..... | 17 | +| 8.1 Emphasis ..... | 18 | +| 8.1.1 Weight ..... | 18 | +| 8.1.2 Posture..... | 18 | +| 8.1.3 Underlining..... | 18 | +| 8.1.4 Blinking..... | 19 | + +| | <i>Page</i> | +|------------------------------------------------------------------------------------|-------------| +| 8.1.5 Image inversion ..... | 19 | +| 8.1.6 Crossing-out ..... | 19 | +| 8.1.7 Colour..... | 19 | +| 8.2 Font selection ..... | 21 | +| 8.2.1 Font specification ..... | 21 | +| 8.2.2 Font designation ..... | 21 | +| 8.2.3 Font invocation..... | 21 | +| 8.3 Subscript and superscript..... | 21 | +| 8.4 Character combinations ..... | 22 | +| 9 Definition of character presentation attributes..... | 22 | +| 9.1 Shared presentation attributes ..... | 23 | +| 9.1.1 Alignment..... | 23 | +| 9.1.2 Character fonts ..... | 23 | +| 9.1.3 Character orientation ..... | 24 | +| 9.1.4 Character path ..... | 24 | +| 9.1.5 Character spacing ..... | 24 | +| 9.1.6 Code extension announcers ..... | 24 | +| 9.1.7 First line offset ..... | 25 | +| 9.1.8 Graphic character sets ..... | 25 | +| 9.1.9 Graphic character subrepertoire ..... | 25 | +| 9.1.10 Graphic rendition..... | 26 | +| 9.1.11 Itemization..... | 26 | +| 9.1.12 Kerning offset..... | 27 | +| 9.1.13 Line layout table ..... | 27 | +| 9.1.14 Line progression ..... | 28 | +| 9.1.15 Line spacing ..... | 28 | +| 9.1.16 Pairwise kerning..... | 28 | +| 9.2 Layout presentation attributes ..... | 28 | +| 9.2.1 Formatting indicator ..... | 28 | +| 9.2.2 Initial offset ..... | 29 | +| 9.3 Logical presentation attributes ..... | 29 | +| 9.3.1 Indentation..... | 29 | +| 9.3.2 Orphan size..... | 30 | +| 9.3.3 Proportional line spacing..... | 30 | +| 9.3.4 Widow size..... | 30 | +| 9.4 Content architecture class attributes ..... | 31 | +| 9.4.1 Content architecture class..... | 31 | +| 9.5 Interactions between presentation attributes and layout directives ..... | 31 | +| 10 Character content portion attributes..... | 31 | +| 10.1 Common coding attributes ..... | 31 | +| 10.2 Other coding attributes ..... | 31 | +| 10.3 Content information ..... | 31 | +| 11 Formal definitions of character content architecture dependent data types ..... | 32 | +| 11.1 Introduction ..... | 32 | +| 11.2 Representation of presentation attributes ..... | 32 | +| 11.3 Representation of coding attributes ..... | 35 | +| 11.4 Representation of non-basic features and non-standard defaults ..... | 35 | +| 12 Graphic Characters ..... | 36 | +| 13 Definition of control functions and the character SPACE..... | 36 | +| 13.1 Shared control functions..... | 37 | +| 13.1.1 Carriage Return (CR) ..... | 37 | +| 13.1.2 Graphic Character Composition (GCC) ..... | 38 | + +| | <i>Page</i> | +|---------------------------------------------------------------------------|-------------| +| 13.1.3 Identify Graphic Subrepertoire (IGS)..... | 38 | +| 13.1.4 Line Feed (LF) ..... | 38 | +| 13.1.5 Partial Line Down (PLD) ..... | 39 | +| 13.1.6 Partial Line Up (PLU) ..... | 39 | +| 13.1.7 Set Character Spacing (SCS)..... | 39 | +| 13.1.8 Select Graphic Rendition (SGR) ..... | 39 | +| 13.1.9 Select Character Spacing (SHS)..... | 42 | +| 13.1.10 Set Line Spacing (SLS) ..... | 42 | +| 13.1.11 Start Reverse String (SRS) ..... | 42 | +| 13.1.12 Selective Tabulation (STAB) ..... | 42 | +| 13.1.13 Substitute Character (SUB) ..... | 42 | +| 13.1.14 Select Line Spacing (SVS) ..... | 43 | +| 13.1.15 Line Position Backward (VPB) ..... | 43 | +| 13.1.16 Line Position Relative (VPR) ..... | 43 | +| 13.1.17 Code extension control functions ..... | 43 | +| 13.2 Layout control functions ..... | 43 | +| 13.2.1 Backspace (BS) ..... | 43 | +| 13.2.2 Character Position Backward (HPB)..... | 44 | +| 13.2.3 Character Position Relative (HPR)..... | 44 | +| 13.2.4 No Justify (JFY) ..... | 44 | +| 13.2.5 Set Additional Character Separation (SACS)..... | 44 | +| 13.2.6 Set Reduced Character Separation (SRCS) ..... | 44 | +| 13.2.7 Set SPACE Width (SSW) ..... | 44 | +| 13.3 Logical control functions..... | 45 | +| 13.3.1 Break Permitted Here (BPH)..... | 45 | +| 13.3.2 No Break Here (NBH)..... | 45 | +| 13.3.3 Parallel Texts (PTX)..... | 45 | +| 13.4 Delimiters ..... | 45 | +| 13.4.1 Start Of Original String (SOOS) ..... | 45 | +| 13.4.2 Start Of String (SOS) ..... | 45 | +| 13.4.3 String Terminator (ST)..... | 45 | +| 13.5 SPACE (SP) ..... | 45 | +| 14 Content layout process..... | 46 | +| 14.1 Introduction ..... | 46 | +| 14.1.1 Purpose ..... | 46 | +| 14.1.2 Available area..... | 46 | +| 14.1.3 Presentation attributes ..... | 46 | +| 14.1.4 Character content architecture classes ..... | 46 | +| 14.1.5 Use of delimiters ..... | 47 | +| 14.1.6 Layout of the content..... | 47 | +| 14.1.7 Layout sequence ..... | 47 | +| 14.1.8 Character sets ..... | 47 | +| 14.2 Content layout process for processable content ..... | 48 | +| 14.2.1 Single basic logical object to single basic layout object ..... | 48 | +| 14.2.2 Single basic logical object to multiple basic layout objects ..... | 52 | +| 14.2.3 Multiple basic logical objects to single basic layout object ..... | 52 | +| 14.3 Content layout process for formatted processable content ..... | 53 | +| 14.4 Content layout process for formatted content..... | 53 | +| 15 Content imaging process ..... | 53 | +| 15.1 Introduction ..... | 53 | +| 15.2 Content imaging process for formatted content ..... | 53 | +| 15.2.1 Determination of initial point ..... | 54 | +| 15.2.2 Choosing character images..... | 54 | +| 15.2.3 Formatting indicator ..... | 54 | + +| | <i>Page</i> | +|--------------------------------------------------------------------------------------|-------------| +| 15.3 Content imaging process for formatted processable content ..... | 54 | +| 16 Interactions between presentation attributes and control functions ..... | 54 | +| 17 Definition of character content architecture classes ..... | 55 | +| 17.1 Formatted character content architecture class ..... | 55 | +| 17.2 Processable character content architecture class ..... | 56 | +| 17.3 Formatted processable character content architecture class ..... | 56 | +| Annex A – SGML representation of character content-specific attributes for ODL ..... | 58 | +| A.1 Introduction ..... | 58 | +| A.2 Names and public identifiers ..... | 58 | +| A.3 Representation of attribute values ..... | 58 | +| A.3.1 Constructed parameters ..... | 58 | +| A.3.2 Parentheses ..... | 59 | +| A.3.3 Alternative representation ..... | 59 | +| A.3.4 String parameters ..... | 59 | +| A.3.5 Keyword parameters ..... | 59 | +| A.3.6 Integer parameters ..... | 59 | +| A.4 Presentation attributes ..... | 59 | +| A.4.1 Shared presentation attributes (format attribute-directives) ..... | 59 | +| A.4.2 Layout presentation attributes (format attributes) ..... | 60 | +| A.4.3 Logical presentation attributes (format directives) ..... | 60 | +| A.5 Coding attributes ..... | 60 | +| Annex B – Summary of content architecture classes ..... | 61 | +| B.1 Formatted character content architecture class ..... | 61 | +| B.2 Processable character content architecture class ..... | 63 | +| B.3 Formatted processable character content architecture class ..... | 65 | +| Annex C – Coded representations of control functions ..... | 67 | +| Annex D – Summary of object identifiers ..... | 68 | + +# Introduction + +This ITU-T Recommendation | International Standard was prepared as a joint publication by ITU-T Study Group VII and ISO/IEC Joint Technical Committee 1. + +At present, the ITU-T Set of Recommendations in the T.410 series | International Standard ISO 8613 consists of: + +- Introduction and general principles; + - Document structures; + - Document profile; + - Open document interchange formats; + - Character content architectures; + - Raster graphics content architectures; + - Geometric graphics content architectures; + - Formal specification of the Open Document Architecture (FODA) +- (The formal specification is applicable to ISO/IEC 8613 only). + +Further Recommendations | International Standards may be added to this series of ITU-T Recommendations | International Standards. + +Development of this set of ITU-T Recommendations | International Standards was originally in parallel with ECMA-101 standard: *Open document architecture*. + +This series of ITU-T Recommendations | International Standards is a new edition of the CCITT T.410-Series of Recommendations (1998) and ISO 8613 (1989). + +Significant technical changes are the inclusion of the following amendments as agreed by ITU-T and ISO/IEC: + +- Alternative Representation; +- Annex on use of MHS/MOTIS; +- Colour; +- Conformance Testing Annex; +- Document Application Profile, Proforma and Notation; +- Security; +- Streams; +- Styles; +- Tiled Raster Graphics. + +In addition, a number of technical corrigenda have been applied to this ITU-T Recommendation | International Standard. + +This ITU-T Recommendation | International Standard contains four annexes: + +- Annex A (integral): SGML representation of character content-specific attributes for ODL; +- Annex B (non-integral): Summary of content architecture classes Summary of content architecture classes; +- Annex C (non-integral): Coded representations of control functions; +- Annex D (non-integral): Summary of object identifiers. + + + +## INTERNATIONAL STANDARD + +## ITU-T RECOMMENDATION + +## **INFORMATION TECHNOLOGY – OPEN DOCUMENT ARCHITECTURE (ODA) AND INTERCHANGE FORMAT: CHARACTER CONTENT ARCHITECTURES** + +# **1 Scope** + +The purpose of the ITU-T Rec. T.410-Series | ISO/IEC 8613 is to facilitate the interchange of documents. + +In the context of these Recommendations | International Standards, documents are considered to be items such as memoranda, letters, invoices, forms and reports, which may include pictures and tabular material. The content elements used within the documents may include graphic characters, raster graphic elements and geometric graphic elements, all potentially within one document. + +NOTE – These Recommendations | International Standards are designed to allow for extensions, including hypermedia features, spreadsheets and additional types of content such as audio and video. + +In addition to the content types defined in these Recommendations | International Standards, ODA also provides for arbitrary content types to be included in documents. + +These Recommendations | International Standards apply to the interchange of documents by means of data communications or the exchange of storage media. + +These Recommendations | International Standards provide for the interchange of documents for either or both of the following purposes: + +- to allow presentation as intended by the originator; +- to allow processing such as editing and reformatting. + +The composition of a document in interchange can take several forms: + +- formatted form, allowing presentation of the document; +- processable form, allowing processing of the document; +- formatted processable form, allowing both presentation and processing. + +These Recommendations | International Standards also provide for the interchange of ODA information structures used for the processing of interchanged documents. + +This ITU-T Recommendation | International Standard: + +- defines a character content architecture that can be used in conjunction with the document architecture defined in ITU-T Rec. T.412 | ISO/IEC 8613-2; +- defines the internal structure of content conforming to this character content architecture; +- defines those aspects of rendition applicable to the presentation of character content; +- defines the presentation and content portion attributes applicable to this character content architecture; +- describes a character content layout process which, together with the document processing model described in ITU-T Rec. T.412 | ISO/IEC 8613-2, determines the layout of character content in basic layout objects. + +# 2 Normative references + +The following ITU-T Recommendations and International Standards contain provisions which, through references, in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The ITU-T Secretariat maintains a list of currently valid ITU-T Recommendations. + +## 2.1 Identical Recommendations | International Standards + +- ITU-T Recommendation T.411 (1992) | ISO/IEC 8613-1:1994, *Information technology – Open Document Architecture (ODA) and Interchange Format: Introduction and general principles*. +- ITU-T Recommendation T.412 (1992) | ISO/IEC 8613-2:1994, *Information technology – Open Document Architecture (ODA) and Interchange Format: Document structures*. +- ITU-T Recommendation T.414 (1992) | ISO/IEC 8613-4:1994, *Information technology – Open Document Architecture (ODA) and Interchange Format: Document profile*. +- ITU-T Recommendation T.415 (1992) | ISO/IEC 8613-5:1994, *Information technology – Open Document Architecture (ODA) and Interchange Format: Open document interchange format*. +- ITU-T Recommendation T.417 (1992) | ISO/IEC 8613-7:1994, *Information technology – Open Document Architecture (ODA) and Interchange Format: Raster graphics content architectures*. +- ITU-T Recommendation T.418 (1992) | ISO/IEC 8613-8:1994, *Information technology – Open Document Architecture (ODA) and Interchange Format: Geometric graphics content architectures*. + +## 2.2 Paired Recommendations | International Standards equivalent in technical content + +- CCITT Recommendation X.208 (1988), *Specification of Abstract Syntax Notation One (ASN.1)*; +ISO/IEC 8824:1990, *Information technology – Open Systems Interconnection – Specification of Abstract Syntax Notation One (ASN.1)*. + +## 2.3 Additional references + +- ISO 2022:1986, *Information processing – ISO 7-bit and 8-bit coded character sets – Code extension techniques*. +- ISO 2375:1985, *Data processing – Procedure for registration of escape sequences*. +- ISO/IEC 6429:1992, *Information technology – Control functions for coded character sets*. +- ISO 6937-1:1983, *Information processing – Coded character sets for text communication – Part 1: General introduction*. +- ISO 6937-2:1983, *Information processing – Coded character sets for text communication – Part 2: Latin alphabetic and non-alphabetic graphic characters*. +- ISO/IEC 7350:1991, *Information technology – Registration of repertoires of graphic characters from ISO 10367*. +- ISO/IEC 8613-10:1991, *Information technology – Text and office systems – Open Document Architecture (ODA) and interchange format – Part 10: Formal specifications*. +- ISO 8879:1986, *Information processing – Text and office systems – Standard Generalized Markup Language (SGML)*. +- ISO/IEC 9541-1:1991, *Information technology – Font information interchange: Part 1 – Architecture*. + +# 3 Definitions + +For the purposes of this Recommendation | International Standard, the definitions given in ITU-T Rec. T.411 | ISO/IEC 8613-1 apply. + +# 4 Abbreviations + +| | | +|------|-------------------------------------| +| BPH | Break Permitted Here | +| BS | Backspace | +| CR | Carriage Return | +| GCC | Graphic Character Composition | +| HPB | Character Position Backward | +| HPR | Character Position Relative | +| IGS | Identify Graphic Subrepertoire | +| JFY | No Justify | +| LF | Line Feed | +| NBH | No Break Here | +| PLD | Partial Line Up | +| PLU | Partial Line Down | +| PTX | Parallel Texts | +| SACS | Set Additional Character Separation | +| SCS | Set Character Spacing | +| SGR | Select Graphic Rendition | +| SHS | Select Character Spacing | +| SLS | Set Line Spacing | +| SOOS | Start Of Original String | +| SOS | Start Of String | +| SRCS | Set Reduced Character Separation | +| SRS | Start Reverse String | +| ST | String Terminator | +| SSW | Set Space Width | +| STAB | Selective Tabulation | +| SUB | Substitute Character | +| SVS | Select Line Spacing | +| VPB | Line Position Backward | +| VPR | Line Position Relative | + +# 5 Conventions + +For the purpose of this Recommendation | International Standard, the conventions given in ITU-T Rec. T.411 | ISO/IEC 8613-1 apply. + +# 6 General principles + +## 6.1 Content architecture classes + +This part of ITU-T Rec. T.410-Series | ISO/IEC 8613 defines three classes of character content architecture: + +- A character content architecture for formatted content which allows for document content to be presented (e.g. printed or displayed) as intended by the originator. Formatted content can be used in any basic component. + +- A character content architecture for processable content which allows for document content to be processed (e.g. edited or formatted). Processable content can be used in any basic logical component. +- A character content architecture for formatted processable content which allows for document content to be processed and also to be presented as intended by the originator. Formatted processable content can be used in any basic component. + +## 6.2 Content + +The content of a basic component that conforms to a character content architecture is a character string. This character string is formed by concatenating the character strings in the content portions of the basic component. + +The content character string consists of a combination of graphic characters, control functions and space characters. + +## 6.3 Presentation attributes + +Presentation attributes are applicable to basic logical and layout components. They contain information that specifies the initial conditions relating to the layout, the imaging and the selection of graphic characters of the content of these basic components. Some of these conditions can be changed by control functions contained within the content. + +Presentation attributes are classified as follows: + +- Logical presentation attributes which can be associated with processable and formatted processable character content. These attributes take effect during the content layout process but are ignored during the content imaging process. +- Layout presentation attributes which can be associated with formatted and formatted processable character content. These attributes take effect during the content imaging process. They are generated either by a content layout process or by a process that creates or edits the formatted or formatted processable content. +- Shared presentation attributes which can be associated with all character content architecture classes. + +These attributes take effect during either or both of the content layout and imaging processes. + +All presentation attributes in this Specification are defaultable. + +## 6.4 Control functions + +Control functions with zero or more parameters may specify information relating to the layout or imaging of subsequent graphic characters. A control function can also be used to extend or replace the set of graphic characters being used. The scope of all control functions is limited to the basic component in which they occur and, in the case of basic logical components, any basic logical component concatenated to this component (see 14.2.3). + +Classification of control functions is similar to that of presentation attributes: + +- Logical control functions which can be used in processable and formatted processable character content. +These control functions take effect during the content layout process but are ignored during the content imaging process. +- Layout control functions which can be used in formatted and formatted processable character content. +These control functions take effect during the content imaging process. They are generated by the content layout process. Alternatively, they may be inserted by a process (not described in ITU-T Rec. T.410-Series | ISO/IEC 8613) that creates or edits the formatted or formatted processable content. +- Shared control functions which can be used in all character content architecture classes. These control functions take effect during either or both of the content layout and imaging processes. + +In addition, formatted processable content may contain control functions known as delimiters. These delimiters are used to indicate a string of one or more graphic characters and/or control functions that have been inserted or deleted as the result of a content layout process (see clause 14). The inserted graphic characters and/or control functions take effect only during the content imaging process. The delimiters take effect during the content layout process by deleting them and the inserted character sequence. + +## 6.5 Graphic characters + +The set of graphic characters used in the content of a basic component, and their coded representation, are specified by presentation attributes and code extension control functions (see clause 12 and 13.1.17). + +Any set or sets of graphic characters may be used in the content of basic components, subject to the restrictions associated with the particular content architecture in use and subject to proper designation and invocation in accordance with ISO 2022. + +Any non-spacing characters included in a graphic character set are not to be used in isolation but only in combination with spacing characters. + +## 6.6 Space characters + +The character SPACE (SP) is considered both as a logical control function and as a graphic character. As a graphic character, it has a graphical representation consisting of the absence of a graphic symbol. As a control function, it indicates a potential line break point (see 14.2.1.3.2). + +NOTE – NBSP (No Break SPace) and any fixed-width space characters, such as “digit space”, “em space” and “en space” are regarded as graphic characters i.e. are not regarded as line break points. + +## 6.7 Coding of content information + +The coded representation of the content information within a content portion is in accordance with the rules specified in ISO 2022. If ODIF is used as the interchange format, the coding shall be performed for an 8-bit environment. + +NOTE 1 – This is equivalent to presuming a code extension announcer value of ESC 2/0 4/7 for the C1 set. + +If ODL is used in the interchange format, the coding should where possible be performed for an 8-bit environment. (The use of ODL is applicable to ISO/IEC 8613 only.) + +NOTE 2 – If an ODL application requires coding for a 7-bit environment, this should be specified by the document application profile, preferably also stating the appropriate code extension announcer(s). + +Coded representations of control functions are defined in ISO 6429 and are summarized in Annex C. + +## 6.8 Internal structure + +### 6.8.1 Formatted content + +Formatted content is content for which all the necessary information relating to the layout and imaging of that content has been specified. Content in this form is intended to be imaged as specified and is not intended to be revised by an editing process or to be reformatted. + +The content of a basic component conforming to a formatted character content architecture consists of one or more lines of characters. Each pair of successive lines is separated by a hard line terminator. The end of the content of a basic component implicitly terminates the last line. + +### 6.8.2 Processable content + +Processable content is content which has not been laid out. Content in this form is suitable for revision by an editing process. + +NOTE – The editing process is implementation dependent and is not described in ITU-T Rec. T.410-Series | ISO/IEC 8613. + +In order to image content in this form, it is necessary to apply a content layout process (see clause 14) to the content which converts the processable content into formatted content (see 6.8.1) or into formatted processable content (see 6.8.3). + +To assist the processing (i.e. editing or layout processes) of processable content, a number of logical presentation attributes and control functions have been defined (see clauses 9 and 13). In addition, the character SPACE is regarded both as a graphic character and as a control function that indicates where a line break may occur when the content is laid out. + +The content of a basic component conforming to a processable character content architecture consists of one or more sequences of characters. Each pair of successive character sequences is separated by a hard line terminator control function. + +At the end of the content of a basic logical component to which another basic logical component is concatenated (see ITU-T Rec. T.412 | ISO/IEC 8613-2), the last character sequence continues into the content of the next basic logical component. In all other cases, the end of the content of the basic logical component implicitly terminates the last character sequence. + +The division into character sequences represents the internal structure of the processable content of a basic logical component. Each character sequence is anonymous, in that no name or identifier is associated with it, and no relationship exists among character sequences except that of sequence. + +### 6.8.3 Formatted processable content + +Formatted processable content is content that is structured such that it contains both the formatted content and the processable content as subsets. It is identical in structure to the processable content, except that it may contain additional control functions and graphic characters that have been added as a result of the content layout process. It is identical in structure to the formatted content, except that it may contain logical control functions and delimiters as well as deleted logical content. + +Thus, formatted processable content can be converted to processable content by deleting (or ignoring) all layout control functions, all occurrences of the delimiters and all control functions and characters inserted within those delimiters. + +Alternatively, formatted processable content can be converted to formatted content by deleting (or ignoring) all logical control functions and the delimiters as well as deleted content but retaining the control functions and characters inserted within the delimiters. + +NOTE – The conversion of formatted processable content to processable content is a reversible process (providing the same layout constraints are applicable to the content layout process) but converting formatted processable content to formatted content is irreversible. + +The formatted view of a basic component conforming to a formatted processable character content architecture consists of one or more lines of characters. Each pair of successive lines is separated by either a hard or soft line terminator. The end of the content of a basic layout component implicitly terminates the last line. + +The processable view of a basic component conforming to a formatted processable character content architecture consists of one or more sequences of characters. Each pair of successive character sequences is separated by a hard line terminator. + +At the end of the content of a basic logical component to which another basic logical component is concatenated (see ITU-T Rec. T.412 | ISO/IEC 8613-2), the last character sequence continues into the content of the next basic logical component. In all other cases, the end of the content of the basic logical component implicitly terminates the last character sequence. + +Soft line terminators are used as separators between lines within a character sequence. The division into character sequences represents the internal structure of the content of a basic logical component. Each character sequence is anonymous, in that no name or identifier is associated with it, and no relationship exists among character sequences except that of sequence. + +# 7 Character positioning + +This clause specifies how characters are to be positioned within a basic layout object. The intention is to aid understanding of the presentation attributes and control functions that relate to character positioning. + +This clause provides for the positioning of any font that is defined in accordance with ISO/IEC 9541-1. This clause also caters for the positioning of characters pertaining to different fonts within the same basic layout object. + +## 7.1 Basic concepts + +### 7.1.1 Character fonts + +In the context of this part of ITU-T Rec. T.410-Series | ISO/IEC 8613, the term *graphic character* is used in its abstract sense; that is, this term refers to a member of a set of graphic symbols used for the representation of information. The term *character image* is then used to refer to the rendition of a graphic character on a presentation medium. + +A *font* is a set of character images, normally with a common design and size. A set of font attributes is associated with the font as a whole and a set of character attributes is associated with each individual character. These attributes are defined in ISO/IEC 9541-1. + +The main purpose of the font attributes is for the recipient to identify the font used by the originator and, in case the specified font is not available, the font and character attributes serve as guidance for the recipient to find an appropriate substitute font among those available. + +Further information concerning the designation and invocation of different fonts within a basic object is given in clause 8. + +### 7.1.2 Directions + +In the context of this part of ITU-T Rec. T.410-Series | ISO/IEC 8613, all directions are expressed as counter clockwise angles of rotation (in degrees) relative to a specified reference direction (an example is given in Figure 1). + +![Figure 1: Example of direction. A diagram showing a horizontal line pointing left labeled 'Reference direction'. A vertical line points down, and a curved arrow indicates a 90-degree counter-clockwise rotation from the reference direction to the vertical line. Labels include 'Angle of rotation' and 'Direction = 90 degrees'.](ace13edeb79bdfa129ed84fbb4ac44e5_img.jpg) + +Figure 1: Example of direction. A diagram showing a horizontal line pointing left labeled 'Reference direction'. A vertical line points down, and a curved arrow indicates a 90-degree counter-clockwise rotation from the reference direction to the vertical line. Labels include 'Angle of rotation' and 'Direction = 90 degrees'. + +T0812850-93/d01 + +Figure 1 – Example of direction + +The *character path* is the direction of progression of successive character images within a line box (defined in 7.1.7) and is expressed as a direction relative to the horizontal direction of the layout object (see Figure 4). + +The *line progression* is the direction of progression of successive line boxes within the basic layout object and is expressed as a direction relative to the character path (see Figure 11). + +The *character orientation* is the direction of the character baseline (defined in 7.1.3) relative to the character path. + +Only one value for the character path, line progression and character orientation may be specified for a basic component. + +### 7.1.3 Character image model + +The *position point* is a reference point associated with a character image (see Figure 2). It is used for the positioning of the character image within a line box. The *escapement point* is a reference point associated with a character image (see Figure 2). It is used for the positioning of the next character image. + +The *character baseline* is an imaginary line across a character image, for the purpose of defining the character orientation. The character baseline is a horizontal line when the character image is in its intended viewing orientation (see Figure 3). + +A position point and escapement point shall be defined for each character orientation which is intended to be used (see Figure 3); i.e. “writing modes” corresponding to the required character orientations shall be defined in the font description, or fall-backs shall be defined in document application profiles. + +A *kern* is that part of the character image that extends beyond its position and escapement points (see Figure 2). + +![Figure 2: Illustration of kerns. The diagram shows a lowercase letter 'f' positioned between two vertical lines. The left vertical line is labeled 'Position point' and the right vertical line is labeled 'Escapement point'. The horizontal distance between these two lines is labeled 'Kern' with arrows pointing to the space between the lines. The letter 'f' is shown with its ascender and x-height. The reference code T0812860-93/d02 is located at the bottom right.](662933fe00899933b36b5a214ac6095c_img.jpg) + +Figure 2: Illustration of kerns. The diagram shows a lowercase letter 'f' positioned between two vertical lines. The left vertical line is labeled 'Position point' and the right vertical line is labeled 'Escapement point'. The horizontal distance between these two lines is labeled 'Kern' with arrows pointing to the space between the lines. The letter 'f' is shown with its ascender and x-height. The reference code T0812860-93/d02 is located at the bottom right. + +Figure 2 – Illustration of kerns + +![Figure 3: Reference points for character image positioning. This figure consists of four diagrams showing the character 'A' at different orientations: 0, 90, 180, and 270 degrees. Each diagram shows the 'Character path' (indicated by an arrow) and the 'Character baseline' (indicated by a horizontal line). The 'Position point' (PP) and 'Escapement point' (EP) are marked on the baseline. For 0 and 180 degrees, the character is upright or inverted along the baseline. For 90 and 270 degrees, the character is rotated 90 degrees clockwise and counter-clockwise respectively, with the baseline becoming vertical. The reference code T0812870-93/d03 is located at the bottom right of the 270-degree diagram.](555df5c0300cb1fca5dc028fec5ec6be_img.jpg) + +Figure 3: Reference points for character image positioning. This figure consists of four diagrams showing the character 'A' at different orientations: 0, 90, 180, and 270 degrees. Each diagram shows the 'Character path' (indicated by an arrow) and the 'Character baseline' (indicated by a horizontal line). The 'Position point' (PP) and 'Escapement point' (EP) are marked on the baseline. For 0 and 180 degrees, the character is upright or inverted along the baseline. For 90 and 270 degrees, the character is rotated 90 degrees clockwise and counter-clockwise respectively, with the baseline becoming vertical. The reference code T0812870-93/d03 is located at the bottom right of the 270-degree diagram. + +PP Position point +EP Escapement point + +Figure 3 – Reference points for character image positioning + +### 7.1.4 Character spacing + +The concept of character spacing is only applicable when a constant spacing font is selected. It is used (in conjunction with the inter-character space) to determine the distance between character images within a line box as defined in 7.2.1. + +The character spacing is equal to the distance between the position points of successive character images when the inter-character space is zero. + +The character spacing is independent of the distance between the position point and escapement point of character images. + +### 7.1.5 Active position + +The *active position* is an abstraction of an imaging device concept such as a cursor. This concept is used in the definitions of control functions (see clause 13) where a sequential method of processing a character string is assumed. + +The active position indicates the point, within the positioning area of a basic layout object, at which the action specified by the next character (graphic character or control function) is to be effected. + +If the next character is a graphic character, its character image is positioned with the position point at the active position and the active position is advanced in the direction of the character path by the amount of spacing (defined in 7.2.1). + +If the next character is a control function, this may cause the active position to move to another point within the positioning area. + +### 7.1.6 Positioning area + +A *positioning area* is a rectangular area, wholly contained within a basic layout object, within which position points and escapement points are to be positioned (see Figure 4). Kerns of character images are permitted to extend beyond the positioning area but are not permitted to extend beyond the edges of the basic layout object. + +Two of the edges of the positioning area are referred to as the *start edge* and *end edge* (see Figure 4). The start edge and the end edge are defined such that the direction from the start edge to the end edge is in the direction of the character path. + +The other two edges of the positioning area are referred to as the top edge and bottom edge. The top edge and the bottom edge are defined such that the direction from the top edge to the bottom edge is in the direction of line progression. + +The start and end edges are indented from the corresponding edges of the basic layout object by a distance referred to as the *kerning offset* (see Figure 4). The kerning offset specified depends upon the fonts of the characters to be positioned in the positioning area. Its value is chosen such that no part of any character image with kerns will extend beyond the boundary of the basic layout object when sequences of character images are positioned within it. + +### 7.1.7 Line boxes + +Within the positioning area, a sequence of character images is positioned within an area called a *line box* (see Figure 11). Each line box is a rectangular area that extends from the start edge to the end edge of the positioning area. + +Each line box contains a reference point called the *line home position* (see Figure 4). This point is used for positioning the line box within the basic layout object. It also serves as the active position for the first graphic character or control function in each line. + +Each line box contains an imaginary line called a *reference line* (see Figure 4). The reference line passes through the line home position in the direction of the character path. It extends from the start edge to the end edge within the line box and is used for the alignment of character images. + +The length of the line box is equal to the distance between the start and end edges. The width (or height) of a line box is equal to the sum of the line box forward extent and the line box backward extent (see Figure 11). The line box backward extent is the distance between the reference line and the edge of the line box in the direction opposite to the direction of line progression. The line box forward extent is the distance between the reference line and the edge of the line box in the direction of line progression. + +![Diagram illustrating character positioning concepts within a line box. The diagram shows a 'Basic layout object' containing a 'Positioning area'. Inside the positioning area is a 'Line box' which contains the text 'pc In a c-box'. Key elements labeled include: 'Top edge' (top of the line box), 'Character path' (direction of text flow), 'Line home position' (start of the line box), 'Reference line' (baseline for characters), 'Start edge' (left edge of the line box), 'End edge' (right edge of the line box), 'Bottom edge' (bottom of the line box), and 'Kerning offset' (space between characters).](ff7ce44f3fdd51bae7b231f34df07c6a_img.jpg) + +Diagram illustrating character positioning concepts within a line box. The diagram shows a 'Basic layout object' containing a 'Positioning area'. Inside the positioning area is a 'Line box' which contains the text 'pc In a c-box'. Key elements labeled include: 'Top edge' (top of the line box), 'Character path' (direction of text flow), 'Line home position' (start of the line box), 'Reference line' (baseline for characters), 'Start edge' (left edge of the line box), 'End edge' (right edge of the line box), 'Bottom edge' (bottom of the line box), and 'Kerning offset' (space between characters). + +T0812880-93/d04 + +Figure 4 – Illustration of character positioning concepts + +The values of the forward and backward extents depend on the maximum extents (measured perpendicular to the reference line) of the character fonts used in the line box. Determination of the forward and backward extents takes into account any displacements of character images perpendicular to the character path, e.g. for subscripts, superscripts and parallel annotation. + +NOTE – As an example, for a Latin font with character path do, line progression d270 and when a single font is used in the line box, then the forward and backward extents are equal to the maximum right and maximum left extents for that font as defined in ISO/IEC 9541-1. + +If no graphic characters are present in a line box, the font that is used to determine the backward and forward extents shall be the last font that is invoked in the line box, if any, or, otherwise, the font that was invoked or was assumed to be invoked (see 8.2.3) before the line box was started. + +## 7.2 Positioning of character images within a line box + +Successive character images are positioned within a line box in the direction of the character path. + +The position points of the character images are aligned on the reference line unless the characters are imaged as subscripts, superscripts or parallel annotation. + +There are several factors which affect the positioning of character images along the reference line: + +- spacing between characters; +- alignment; +- tabulation; +- character ordering; +- parallel annotation; +- subscript/superscript; +- pairwise kerning; +- first line offset; +- itemization. + +### 7.2.1 Spacing between characters + +The *inter-character space* is an additional amount of spacing between the position points of successive character images, in the direction of the character path (see 7.1.4). A negative value indicates a reduction in the spacing between successive character images. + +The distance between the position points of successive character images may be constant or variable depending upon the font as follows: + +- For fonts with *constant spacing*, the distance between the position points of successive character images is independent of the characters and is the sum of the character spacing (as specified by presentation attributes and control functions) and the inter-character space (see Figure 5). +- For fonts with *variable spacing*, the distance between the position points of successive character images is dependent upon the character, i.e. normally the distance between the position point and the escapement point of a character, and is the sum of the net escapement of the character (as specified by the font) and the inter-character space (see Figure 6). + +![Figure 5: Spacing for constant spacing font. The diagram shows the word 'Italic' in a bold, sans-serif font. A horizontal line represents the 'Reference line'. Above the line, an arrow labeled 'Character path' points to the right. Below the line, a series of vertical bars represent the 'Character spacing' for each letter. The 'Inter-character space' is indicated by a double-headed arrow between the end of one character's spacing bar and the start of the next. The text 'T0812890-93/d05' is located at the bottom right of the diagram.](6551284cc15a2ba106451485aaac265a_img.jpg) + +Figure 5: Spacing for constant spacing font. The diagram shows the word 'Italic' in a bold, sans-serif font. A horizontal line represents the 'Reference line'. Above the line, an arrow labeled 'Character path' points to the right. Below the line, a series of vertical bars represent the 'Character spacing' for each letter. The 'Inter-character space' is indicated by a double-headed arrow between the end of one character's spacing bar and the start of the next. The text 'T0812890-93/d05' is located at the bottom right of the diagram. + +Figure 5 – Spacing for constant spacing font + +![Figure 6: Spacing for variable spacing font. The diagram shows the word 'Italic' in a serif font. A horizontal line represents the 'Reference line'. Above the line, an arrow labeled 'Character path' points to the right. Below the line, a series of vertical bars represent the 'Net escapement' for each letter. The 'Inter-character space' is indicated by a double-headed arrow between the end of one character's escapement bar and the start of the next. The text 'T0812900-93/d06' is located at the bottom right of the diagram.](67af94a7c462e85f3a310c9a45c0980d_img.jpg) + +Figure 6: Spacing for variable spacing font. The diagram shows the word 'Italic' in a serif font. A horizontal line represents the 'Reference line'. Above the line, an arrow labeled 'Character path' points to the right. Below the line, a series of vertical bars represent the 'Net escapement' for each letter. The 'Inter-character space' is indicated by a double-headed arrow between the end of one character's escapement bar and the start of the next. The text 'T0812900-93/d06' is located at the bottom right of the diagram. + +Figure 6 – Spacing for variable spacing font + +The space width, i.e. the width of the SP (Space) character image, shall be determined as follows: + +- for any SP that follows a soft line terminator and precedes the first graphic character of a line, or precedes a soft line terminator and follows the last graphic character of a line, the width is equal to zero; +- in a constant spacing font, the default width equals the character spacing; +- in a variable spacing font, the width is implicitly defined by the font; +- for all fonts, the width may be specified by a control function. + +### 7.2.2 Alignment + +The character images are positioned within a line box in accordance with the attribute “alignment” as follows: + +- *Start-aligned* – The position point of the first character image is placed at the line home position. +- *End-aligned* – The escapement point of the last character is placed at the end edge of the positioning area. +- *Centred* – The distance from the line home position to the position point of the first character image is approximately equal to the distance from the escapement point of the last character image to the end edge of the positioning area. +- *Justified* – The position point of the first character image is placed at the line home position and the escapement point of the last character image is made coincident with the end edge of the positioning area by appropriately setting the space width and/or the inter-character space. + +### 7.2.3 Tabulation + +The position of character images along a reference line can be controlled by means of a set of *tabulation stops*. Each tabulation stop specifies a point along a reference line relative to the start edge of the positioning area. + +A string of character images can be placed at a tabulation stop by means of a control function embedded in the text. The string may be start-aligned, end-aligned, centred or aligned around one or more specified characters within that string as follows (see Figure 7): + +- *Start-aligned* – The position point of the first character image of the string is placed at the tabulation stop. +- *End-aligned* – The escapement point of the last character image of the string is placed at the tabulation stop. +- *Centred* – The string is placed such that the position point of the first character image and the escapement point of the last character image of the string are approximately equidistant from the tabulation stop. +- *Aligned-around* – The position point of the first character image of the first instance of the specified group of characters in that string is positioned at the tabulation stop. If the specified group of characters does not appear in the text associated with that tabulation stop, then the alignment defaults to end-aligned as defined above. + +### 7.2.4 Character ordering + +Within the content of a basic object, the interchange order is always the reading order of the language used. + +In the case of certain languages, e.g. Arabic and Hebrew, where the alphanumeric text is read from right to left and the numeric text is read from left to right, the interchanged stream shall indicate the change in presentation direction at the appropriate point(s). + +This is necessary since control functions in character content architectures are defined to operate sequentially according to their position in the character stream. + +When a string of characters with reversed presentation direction is embedded in the text with normal presentation direction, the image of the last character of the string with reversed presentation direction is positioned adjacent to the image of the last character of the preceding string with normal presentation direction (see Figure 8). + +NOTE – In Figure 8, the terms “first” and “last” are used in relation to the interchange order and the terms “normal” and “reversed” in relation to the direction of the character path. + +![Diagram showing four tabulation stops: Start-aligned, End-aligned, Centred, and Aligned-around ](812e188283162af0b54fb3e30ffee51b_img.jpg) + +Tabulation stops + +Start-aligned      End-aligned      Centred      Aligned-around "." + +This is start aligned text      This is end aligned text      This is centred text      124.56 +is 23.5 +start 1254.76 +aligned 32.456 +text 342 + +T0812910-93/d07 + +Diagram showing four tabulation stops: Start-aligned, End-aligned, Centred, and Aligned-around + +Figure 7 – Tabulation + +![Diagram showing character ordering. A box contains 'HGF123EDCBA'. Arrows indicate the character path: from left to right for 'HGF', then right to left for '123', then left to right for 'EDCBA'. Labels point to specific characters: 'Last character of normal P/D' (A), 'Last character of reversed P/D' (3), 'First character of reversed P/D' (E), and 'First character of next normal P/D' (H). A legend defines the square symbol as 'Control function to reverse presentation direction' and 'P/D' as 'Presentation direction'.](79e1709a7317ead45379cbb8ff3ba802_img.jpg) + +Interchange order = ABCDE ■ 123 ■ FGH + +**HGF123EDCBA** + +Character path + +Last character of normal P/D +Last character of reversed P/D +First character of reversed P/D +First character of next normal P/D + +■ Control function to reverse presentation direction +P/D Presentation direction + +T0812920-93/d08 + +Diagram showing character ordering. A box contains 'HGF123EDCBA'. Arrows indicate the character path: from left to right for 'HGF', then right to left for '123', then left to right for 'EDCBA'. Labels point to specific characters: 'Last character of normal P/D' (A), 'Last character of reversed P/D' (3), 'First character of reversed P/D' (E), and 'First character of next normal P/D' (H). A legend defines the square symbol as 'Control function to reverse presentation direction' and 'P/D' as 'Presentation direction'. + +Figure 8 – Character ordering + +### 7.2.5 Parallel annotation + +Two character strings can be presented in parallel, by delimiting them such that the second string is used to indicate the pronunciation and interpretation of the first string. This feature is intended to be used for the Japanese language to provide pronunciation and interpretation information (Ruby) in the form of Kana character(s) for one or more Kanji characters. This is indicated in the formatted text by the Kana character(s) being centred either above or to the right of the Kanji character(s), for character image orientations orthogonal and parallel to the character path respectively (see Figure 9). + +Where centering would result in Kana characters being positioned outside the positioning area, then the Kana character string is positioned such that it is start-aligned or end-aligned with the edge of the available area. + +![Figure 9: Diagram showing the imaged content of Japanese Ruby. It displays the Kanji characters '漢字' in large boxes with the Kana characters 'カ', 'ン', 'ジ' in smaller boxes centered above them. Dimension lines indicate 'xx' as the total width of the Kana string, 'zz' as the width of the character 'ジ', and 'yy' as the height of the Kanji boxes. Reference points 'a', 'b', and 'c' are marked along the baseline.](09955ff8214ffb6947951fc0f60eb6ab_img.jpg) + +P +T +X +1 + +漢字 + +P +T +X +3 + +カンジ + +P +T +X +0 + +Processable content + +⬇️ Content layout process + +P +T +X +1 + +漢字 + +P H +T P xx +X B +3 + +S V +O P yy +S B + +S +T + +カンジ + +P H +T P zz +X R +0 + +S H +O P yy +S R + +S +T + +Formatted processable content + +⬇️ Content imaging process + +T0812930-93/d09 + +Figure 9: Diagram showing the imaged content of Japanese Ruby. It displays the Kanji characters '漢字' in large boxes with the Kana characters 'カ', 'ン', 'ジ' in smaller boxes centered above them. Dimension lines indicate 'xx' as the total width of the Kana string, 'zz' as the width of the character 'ジ', and 'yy' as the height of the Kanji boxes. Reference points 'a', 'b', and 'c' are marked along the baseline. + +HPB, HPR, VPB, VPR, SOS, ST, PTX +xx, zz, yy + +Control functions (see clause 13) +Parameter values determined by the content layout process + +The current reference point moves from "a" to "b" to "c" and then returns to "a". + +**Figure 9 – An example of the specification of Japanese Ruby** + +### 7.2.6 Subscript/superscript + +Subscript rendition allows for the active position to be displaced from the reference line in the direction of line progression. + +Superscript rendition allows for the active position to be displaced from the reference line in the direction opposite to that of line progression. + +The combined effect of all subscript/superscript renditions within a line box shall be such that the active position is returned to the reference line before the occurrence of a hard or soft line terminator. + +### 7.2.7 Pairwise kerning + +Pairwise kerning allows for the moving of the active position from that defined by the preceding character. The distance and direction depend both on the character being imaged and the preceding character. + +In the case of a constant spacing font, pairwise kerning is ignored. + +In the case of a variable spacing font, the actual distance between the escapement point of one character image and the position point of the next character image is modified by the kerning information as defined in the character attributes of the font. + +### 7.2.8 First line offset + +First line offset allows for character imaging of the first line of a basic component to start at a position displaced from the line home position. + +The offset is either in the direction of the character path (producing first line indentation) or in the direction opposite to the character path (producing overhang) as illustrated in Figure 10. + +### 7.2.9 Itemization + +Itemization allows for imaging of an item identifier on the first line of a basic component in positions which are not directly constrained by the line home position and the first line offset (see Figure 10). + +An *item identifier* is a string of characters that precedes and is separated from the remainder of the first line of a basic component. + +A start offset and an end offset are defined relative to the line home position. These offsets determine the location of the item identifier and the separation between the item identifier and the line home position. + +The item identifier may be positioned on the first line in accordance with the item identifier alignment attribute as follows: + +- *Start-aligned* – The position point of the first character image of the item identifier is placed at the start offset. +- *End-aligned* – The escapement point of the last character image of the item identifier is placed at the end offset. + +## 7.3 Positioning of line boxes within a basic layout object + +For positioning of line boxes in a basic layout object, the area of that object is independent of any adjoining areas. No part of the image shall be permitted to extend beyond the boundaries of the basic layout object. + +The *initial point* is the point relative to which all line boxes are positioned within the basic layout object (see 9.2.2 and Figure 11). + +The line home position of the first line box is at the initial point of the basic layout object. Subsequent line home positions are located on a line through the initial point in the direction of line progression. + +![Diagram for Example 10.1 showing a text block with a positive First Line Offset (FLO). The text is indented from the left margin. The Line Home Position (LHP) is at the start of the first line.](73b5cce955ba9415a98791db7b0080ad_img.jpg) + +Diagram for Example 10.1 showing a text block with a positive First Line Offset (FLO). The text is indented from the left margin. The Line Home Position (LHP) is at the start of the first line. + +Example 10.1 + +First line offset: positive + Identifier alignment: no itemization + Identifier start offset: zero + Identifier end offset: zero + Indentation: zero + +![Diagram for Example 10.2 showing a text block with a negative First Line Offset (FLO). The text is indented from the left margin. The Line Home Position (LHP) is at the start of the first line.](4b87467ad9642943235f48f7d4b59449_img.jpg) + +Diagram for Example 10.2 showing a text block with a negative First Line Offset (FLO). The text is indented from the left margin. The Line Home Position (LHP) is at the start of the first line. + +Example 10.2 + +First line offset: negative + Identifier alignment: no itemization + Identifier start offset: zero + Identifier end offset: zero + Indentation: positive + +![Diagram for Example 10.3 showing a text block with a positive Identifier Start Offset (ISO). The identifier 'ABCD' is indented from the left margin. The Line Home Position (LHP) is at the start of the first line.](5132b3a97ac70fe4765c1e07e66b72b3_img.jpg) + +Diagram for Example 10.3 showing a text block with a positive Identifier Start Offset (ISO). The identifier 'ABCD' is indented from the left margin. The Line Home Position (LHP) is at the start of the first line. + +Example 10.3 + +First line offset: zero + Identifier alignment: start aligned + Identifier start offset: negative + Identifier end offset: zero + Indentation: positive + +![Diagram for Example 10.4 showing a text block with a positive Identifier End Offset (IEO). The identifier 'ABCD' is indented from the left margin. The Line Home Position (LHP) is at the start of the first line.](d3b5eac55166fc428a223bba5c46961b_img.jpg) + +Diagram for Example 10.4 showing a text block with a positive Identifier End Offset (IEO). The identifier 'ABCD' is indented from the left margin. The Line Home Position (LHP) is at the start of the first line. + +Example 10.4 + +First line offset: zero + Identifier alignment: end aligned + Identifier start offset: negative + Identifier end offset: negative + Indentation: positive + +![Diagram for Example 10.5 showing a text block with a positive First Line Offset (FLO) and a positive Identifier End Offset (IEO). The identifier 'TBW PMKJGLS' is indented from the left margin. The Line Home Position (LHP) is at the start of the first line.](6a555cff11e140861ce08db72b01a6a2_img.jpg) + +Diagram for Example 10.5 showing a text block with a positive First Line Offset (FLO) and a positive Identifier End Offset (IEO). The identifier 'TBW PMKJGLS' is indented from the left margin. The Line Home Position (LHP) is at the start of the first line. + +Example 10.5 + +First line offset: positive + Identifier alignment: start aligned + Identifier start offset: negative + Identifier end offset: positive + Indentation: positive + +FLO First line offset + ISO Identifier start offset + IEO Identifier end offset + LHP Line home position + IND Indentation + +T0812940-93/D10 + +Figure 10 – Illustration of itemization, first line offset and indentation + +![Diagram illustrating character positioning concepts. It shows a 'Basic layout object' containing a 'Positioning area'. Within the positioning area, a vertical line represents the 'Line home position'. A 'Line box' is shown as a horizontal rectangle. The 'Initial point' is marked at the top-left corner of the line box. 'Line progression' is indicated by a downward arrow on the right. 'Line box backward extent' and 'Line box forward extent' are shown as vertical distances from the initial point to the top and bottom of the line box, respectively. The diagram is labeled T0812950-93/d11.](a74294f34a0c736b7ee0f5f0cdca7e28_img.jpg) + +Diagram illustrating character positioning concepts. It shows a 'Basic layout object' containing a 'Positioning area'. Within the positioning area, a vertical line represents the 'Line home position'. A 'Line box' is shown as a horizontal rectangle. The 'Initial point' is marked at the top-left corner of the line box. 'Line progression' is indicated by a downward arrow on the right. 'Line box backward extent' and 'Line box forward extent' are shown as vertical distances from the initial point to the top and bottom of the line box, respectively. The diagram is labeled T0812950-93/d11. + +**Figure 11 – Illustration of character positioning concepts** + +The distance between the line home positions of two successive line boxes shall be determined as follows: + +- when proportional line spacing is to be performed, the distance between the reference lines of two successive line boxes is evaluated by an implementation dependent algorithm not defined in ITU-T Rec. T.410-Series | ISO/IEC 8613; +- when proportional line spacing is not to be performed, the distance between the reference lines of two successive line boxes is equal to the current line spacing as specified by presentation attributes and control functions. + +# 8 Character imaging + +Four groups of specifications may apply to the imaging of graphic character elements in a basic object, namely those relating to: + +- emphasis; +- font selection; +- subscript and superscript; +- character combinations. + +These groups of specifications are defined below. + +###### NOTES + +1 Certain emphasis (e.g. 'weight', 'posture') and subscript/superscript rendition may be achieved by font selection. + +2 Document application profiles may define additional restrictions on the use of the character features defined in this clause. In addition, an implementation may replace an imaging feature by an alternative fall-back feature. However, ITU-T Rec. T.410-Series | ISO/IEC 8613 does not define preferred fall-back features. It should also be noted that use of a fall-back feature may cause incorrect or misleading information to be conveyed to the user. It is particularly recommended that a fall-back is not used when the feature 'crossed-out' is specified (see 8.1.6). + +## 8.1 Emphasis + +Portions of text may be visually differentiated or emphasized in character imaging. Seven methods of emphasis are provided: + +- weight; +- posture; +- underlining; +- blinking; +- image inversion; +- crossing-out; +- colour. + +All of these may be controlled by means of rendition selection using the presentation attribute “Graphic rendition” and the control function SGR (Select Graphic Rendition). + +The emphasis takes effect at the active position of the line box where the control function initiates it and ends at the active position of the line box where the control function specifies an end to the emphasis or at the end of the object. + +NOTE – Not all forms of emphasis allowed by ITU-T Rec. T.410-Series | ISO/IEC 8613 are applicable to all presentation devices. For example, in printed text, ‘blinking’ may not be able to be represented, a second colour may be an available alternative to ‘faint’ (decreased intensity), and ‘image inversion’ may only be practicable by the use of appropriately designed cameo fonts. + +### 8.1.1 Weight + +This feature provides emphasis or de-emphasis by means of varying the contrast or intensity of the character image. + +Using rendition selection, three weights are provided: + +- faint (decreased intensity); +- normal intensity (neither faint nor bold); +- bold (increased intensity). + +Only one of these may be in effect at any one point in the character stream, so that invoking one resets the others. + +### 8.1.2 Posture + +This feature provides for a change of posture between an upright font and an italic font. + +Using rendition selection, two renditions are provided: + +- not italicized; +- italicized. + +Only one of these renditions may be in effect at any one point in the character stream, so that invoking one resets the other. + +### 8.1.3 Underlining + +This feature provides for underlining character images. Three renditions are provided: + +- not underlined; +- underlined; +- doubly underlined. + +Only one of these renditions may be in effect at any one point in the character stream, so that invoking one resets the others. + +NOTE – For writing systems other than those that use a horizontal writing direction, underlining may be replaced by a suitable emphasis. + +### 8.1.4 Blinking + +This feature provides for flashing of the graphic symbol in the line box ON and OFF. Three renditions are provided: + +- steady (not blinking); +- slowly blinking; +- rapidly blinking. + +Only one of these renditions may be in effect at any one point in the character stream, so that invoking one resets the others. + +NOTE – Slow blinking should be taken as less than 150 ON/OFF cycles per minute and rapid blinking should be taken as more than 150 cycles per minute. + +### 8.1.5 Image inversion + +This feature provides for the colours of the graphic symbol and the line box to be exchanged. + +Two renditions are provided: + +- positive image; +- negative image. + +If the character content is coloured, then the rendition 'negative image' causes the character foreground and character background colours to be exchanged. + +Only one of these renditions may be in effect at any one point in the character stream, so that invoking one resets the other. + +NOTE – Simple inversion of the pels within the line box area may not be sufficient for inverting the character image. + +### 8.1.6 Crossing-out + +This feature allows characters to be marked for deletion. The method of crossing out is not defined but the characters should be legible. Two renditions are provided: + +- not crossed-out; +- crossed-out. + +Only one of these renditions may be in effect at any one point in the character stream, so that invoking one resets the other. + +### 8.1.7 Colour + +This feature provides for characters, words or other elements of a character content portion to be presented in a different colour. More than one emphasis colour is permitted in a single character content portion. The character content architecture can specify colour specifications in RGB or CMY(K) colour spaces (see Figure 12). Colours may be specified in either direct mode or indexed mode. + +When imaging text, there are two coloured elements for each character: the character image and the character image background (see Figure 13). For each character, the character image is imaged in a colour referred to as the *character foreground colour* and the character image background is imaged in a colour referred to as the character background colour. + +The use of character background colours can be described by means of the following rules. The character background colour is applied to rectangular areas above and between the escapement and position points of successive character images in a line box termed *segments*. + +Orthogonal to the character path, the extent of each line box delimits that segment with the character background colour. + +For each line box, in the direction of the character path, the first segment begins at the line home position and the last segment ends at either the hard line terminator or the end of the line box. The specification of a new value for the character background colour or the emphasis "image inversion" (see 8.1.5) within the content terminates the current segment at the escapement point of the previous character and starts a new segment at the position point of the next character. + +Usage of the control functions HPB (Character Position Backward) and HPR (Character Position Relative) terminates the current segment before moving the active position and starts a new segment at the new active position. + +![Figure 12: Relationships between colour space. This diagram illustrates the flow of color information from input spaces to an imaging system. At the top, 'RGB' and 'CMY(K)' boxes are connected by a dashed line labeled 'Optional transformation'. Both have arrows pointing to a central 'Reference CIE XYZ' box. A solid line connects 'Reference CIE XYZ' to an 'Imaging system colour space' box at the bottom. A dashed line labeled 'Content imaging transformation' separates the 'Reference CIE XYZ' box from the 'Imaging system colour space' box. The diagram is labeled 'Character content architecture' and 'T0812960-93/d12'.](d17aa1fcc3b86503ad1dd0717a6c34c2_img.jpg) + +Figure 12: Relationships between colour space. This diagram illustrates the flow of color information from input spaces to an imaging system. At the top, 'RGB' and 'CMY(K)' boxes are connected by a dashed line labeled 'Optional transformation'. Both have arrows pointing to a central 'Reference CIE XYZ' box. A solid line connects 'Reference CIE XYZ' to an 'Imaging system colour space' box at the bottom. A dashed line labeled 'Content imaging transformation' separates the 'Reference CIE XYZ' box from the 'Imaging system colour space' box. The diagram is labeled 'Character content architecture' and 'T0812960-93/d12'. + +Figure 12 – Relationships between colour space + +![Figure 13: Areas affected by colour emphasis. This diagram shows a rectangular area divided into three vertical sections labeled 'B', 'J', and 'S'. The top section is labeled 'Block background colour'. The middle section is divided into 'Character foreground colour' (the letters themselves) and 'Character background colour' (the area behind the letters). The bottom section is labeled 'Position point for B', 'Position point for J', and 'Position point for S'. A vertical double-headed arrow on the left is labeled 'Line box height'. The diagram is labeled 'T0812970-93/d13'.](9c1d3678db4a12d5864cb2a4def1135d_img.jpg) + +Figure 13: Areas affected by colour emphasis. This diagram shows a rectangular area divided into three vertical sections labeled 'B', 'J', and 'S'. The top section is labeled 'Block background colour'. The middle section is divided into 'Character foreground colour' (the letters themselves) and 'Character background colour' (the area behind the letters). The bottom section is labeled 'Position point for B', 'Position point for J', and 'Position point for S'. A vertical double-headed arrow on the left is labeled 'Line box height'. The diagram is labeled 'T0812970-93/d13'. + +Figure 13 – Areas affected by colour emphasis + +Initially, the values for the character foreground colour and the character background colour are those specified by the attributes “content foreground colour” and “colour background colour” of the basic object with the associated character content. These attributes are defined in ITU-T Rec. T.412 | ISO/IEC 8613-2. The two colours can independently be altered within the content information using the control function SGR (Select Graphic Rendition) with values 30 to 38 for the character foreground colour and values 40 to 48 for the character background colour. If negative image is in effect these two colours are exchanged. + +## 8.2 Font selection + +The capability for font selection is based upon: + +- *font specification* – The required fonts and their characteristics shall be specified in the document profile (see ITU-T Rec. T.414 | ISO/IEC 8613-4). There is no limit to the number of fonts that can be specified; +- *font designation* – A subset of these fonts can be designated for use within a basic component by means of the presentation attribute “character fonts”. This subset is limited to a maximum of ten fonts; +- *font invocation* – Any of the fonts within this subset can be invoked by means of the presentation attribute “graphic rendition” and/or control function SGR (Select Graphic Rendition). + +### 8.2.1 Font specification + +Within the document profile, there is an attribute “fonts list”. This specifies, for each font used in the document: + +- a font identifier, represented by an integer, unique within the document; +- a font description consisting of a set of font attributes specifying properties that are common to all characters of the font, e.g. weight, posture, constant or variable spacing, as well as properties that are unique to the individual characters. + +The font description includes a structured font name as defined in ISO/IEC 9541-1. The other font attributes allow a recipient to select a suitable substitute font when the font specified by the structured font name is not available. + +NOTE – It is necessary to consider that font designs are typically proprietary, and that, in addition, the recipient may have a limited repertoire. Thus, there can be no assurance that a particular font selected by the originator is actually available at the recipient’s location, unless the originator has prior knowledge of the facilities available to the recipient. Since this would not generally be true in open interchange, it is necessary to specify the font and character characteristics in a manner that facilitates the selection of a near-equivalent alternative, from the repertoire of fonts available to the recipient. + +### 8.2.2 Font designation + +The presentation attribute “Character fonts” enables a subset of up to ten fonts from the set of fonts specified in the attribute “Fonts list” in the document profile to be designated for use within the basic component. + +Each font and its size is specified together with the method of invoking the font, i.e. as the primary or one of the alternative fonts. + +If no font is designated for the primary font or for a particular alternative font, it is left to the recipient to select a suitable font for the primary or alternative font concerned. + +#### NOTES + +- 1 The selection of a substitution font may depend upon the characteristics and capabilities of the presentation device. +- 2 When selecting a suitable font, it is recommended to consider the specification of character spacing and line spacing for its dimension and the specification of emphasis for its design. +- 3 It is not recommended to use proportional fonts for the non-designated font in a layout process that generates a formatted document that is to be interchanged. + +### 8.2.3 Font invocation + +The control function SGR (Select Graphic Rendition) is used to invoke the primary font or one of the nine alternative fonts. Such an invocation can be performed anywhere within the content of a basic component. + +For the initial conditions at the beginning of the basic component, the font indicated by the presentation attribute “Graphic rendition” is invoked. In the absence of this attribute, the primary font is assumed to be invoked. If no font has been specified, the font used is implementation dependent. + +When a designated font is invoked, any specification of weight or posture by an SGR parameter value, or by the presentation attribute “Graphic rendition”, is ignored. + +Invocation of a character set by means of a code extension control function does not imply invocation of a font for that character set. + +## 8.3 Subscript and superscript + +The control functions PLD (Partial Line Down) and PLU (Partial Line Up) provide for characters to be imaged as subscript and superscript respectively. + +Finer control of subscript and superscript rendition is provided by the control functions VPB (Line Position Backward) and VPR (Line Position Relative). + +## 8.4 Character combinations + +Two or more characters can be imaged as if they were a single symbol. + +The control function GCC (Graphic Character Composition) within the content identifies the string of characters to be imaged as a single symbol. + +# 9 Definition of character presentation attributes + +Presentation attributes are applicable to basic logical and layout components. They specify the initial conditions at the start of the rendition of the content of that basic component. The content architecture associated with each basic component can have the means for changing certain of these presentation attributes by means of control functions embedded in the content; such capabilities are indicated in the definition of each presentation attribute. + +The following categories of presentation attributes are defined: + +- shared attributes which are available to all character content architecture classes; +- layout attributes which are available to formatted and formatted processable form character content architecture classes; +- logical attributes which are available to processable and formatted processable form character content architecture classes. + +For each presentation attribute, a default value is defined. This value is used in the defaulting mechanism as defined in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +This clause also defines values specific to character content architectures for the attribute “content architecture class” as defined in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +Table 1 – Character presentation attributes + +| Shared attributes | Layout attributes | +|---------------------------------|---------------------------| +| Alignment | Formatting indicator | +| Character fonts | Initial offset | +| Character orientation | | +| Character path | | +| Character spacing | | +| Code extension announcers | | +| First line offset | | +| Graphic character sets | Logical attributes | +| Graphic character subrepertoire | | +| Graphic rendition | Indentation | +| Itemization | Proportional line spacing | +| Kerning offset | Orphan size | +| Line layout table | Widow size | +| Line progression | | +| Line spacing | | +| Pairwise kerning | | + +## 9.1 Shared presentation attributes + +### 9.1.1 Alignment + +| | | +|---------------------|--------------------------------------------------------------| +| CATEGORY: | Shared | +| PERMISSIBLE VALUES: | ‘start-aligned’<br>‘end-aligned’<br>‘centred’<br>‘justified’ | +| DEFAULT VALUE: | ‘start-aligned’ | + +#### DEFINITION: + +This attribute specifies the method of character alignment (see 7.2.2). + +The character alignment cannot be altered within the content of a basic component. Application of the value ‘justified’ may be suppressed by an occurrence of the control function JFY (No Justify). + +This attribute can be overridden by the presentation attribute “line layout table” when any tabulation stops are specified (see 9.1.13). + +### 9.1.2 Character fonts + +| | | | | | | | | | | | | +|--------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------|------------------------|-------------------------|------------------------|-------------------------|------------------------|------------------------|--------------------------|-------------------------|------------------------| +| CATEGORY: | Shared | | | | | | | | | | | +| STRUCTURE: | ten optional parameters: <table style="margin-left: 150px;"> <tr><td>primary font</td></tr> <tr><td>first alternative font</td></tr> <tr><td>second alternative font</td></tr> <tr><td>third alternative font</td></tr> <tr><td>fourth alternative font</td></tr> <tr><td>fifth alternative font</td></tr> <tr><td>sixth alternative font</td></tr> <tr><td>seventh alternative font</td></tr> <tr><td>eighth alternative font</td></tr> <tr><td>ninth alternative font</td></tr> </table> | primary font | first alternative font | second alternative font | third alternative font | fourth alternative font | fifth alternative font | sixth alternative font | seventh alternative font | eighth alternative font | ninth alternative font | +| primary font | | | | | | | | | | | | +| first alternative font | | | | | | | | | | | | +| second alternative font | | | | | | | | | | | | +| third alternative font | | | | | | | | | | | | +| fourth alternative font | | | | | | | | | | | | +| fifth alternative font | | | | | | | | | | | | +| sixth alternative font | | | | | | | | | | | | +| seventh alternative font | | | | | | | | | | | | +| eighth alternative font | | | | | | | | | | | | +| ninth alternative font | | | | | | | | | | | | + +Each parameter has two subparameters: + +| | | | +|---------------------|-------------------------|----------------------| +| | | font size | +| | | font identifier | +| PERMISSIBLE VALUES: | font size: | any positive integer | +| | font identifier: | any positive integer | +| DEFAULT VALUE: | no fonts are designated | | + +#### DEFINITION: + +This attribute designates up to ten fonts which may be used within the basic component (see 7.1.2 and 8.2). These fonts are referred to as the primary font, the first alternative font, the second alternative font etc. The fonts designated shall be chosen from the fonts listed in the document profile (see ITU-T Rec. T.414 | ISO/IEC 8613-4). + +The subparameter “font size” specifies the size of the font i.e. the height of the character image; its value is an integer representing the size of the font in SMUs. + +The subparameter “font identifier” is an integer equal to the font identifier associated with the font in the document profile attribute “Fonts list”. + +One of the designated fonts may be invoked at the start of the presentation of the content associated with a basic component by means of the presentation attribute “Graphic rendition”, otherwise the primary font is assumed to be invoked. Also, fonts may be invoked within the content by means of the control function SGR (Select Graphic Rendition). + +### 9.1.3 Character orientation + +CATEGORY: Shared + +PERMISSIBLE VALUES: d0 +d90 +d180 +d270 + +DEFAULT VALUE: d0 + +DEFINITION: + +This attribute specifies the character orientation (see 7.1.3). + +The character orientation cannot be altered within the content of a basic component. + +### 9.1.4 Character path + +CATEGORY: Shared + +PERMISSIBLE VALUES: d0 +d90 +d180 + +DEFAULT VALUE: d0 + +DEFINITION: + +This attribute specifies the character path (see 7.1.2). + +The character path cannot be altered within the content of a basic component. However, local changes of the relationship between the imaging order of the characters and the interchange order can be specified by the control function SRS (Start Reverse String). + +### 9.1.5 Character spacing + +CATEGORY: Shared + +PERMISSIBLE VALUES: any positive integer + +DEFAULT VALUE: the equivalent of 120 BMUs + +DEFINITION: + +This attribute specifies the character spacing which applies at the beginning of the basic component (see 7.1.4). + +The value of this attribute is an integer specifying the distance in SMUs. + +The character spacing value is only used while a constant spacing font is in use; it has no effect while a variable spacing font is in use. + +It can be altered within the content of a basic component by means of the control functions SHS (Select Character Spacing) or SCS (Set Character Spacing). + +### 9.1.6 Code extension announcers + +CATEGORY: Shared + +PERMISSIBLE VALUES: The value of this attribute consists of a string of escape sequences, in accordance with ISO 2022, to announce the use of code extension features. The permissible final characters of the escape sequences are: 4/1, 4/3, 4/4, 4/7, 4/9, 4/11, 4/12, 4/13, 4/14, 5/0, 5/3, 5/5, 5/10 and 5/11 + +DEFAULT VALUE: Escape sequences with final characters: 5/0, 5/5, 4/7, 4/9 and 4/11. + +DEFINITION: + +This attribute announces the code extension features allowed in the basic component. + +The set of code extension features announced by this attribute cannot be altered within the content of a basic component. + +The default value announces an 8-bit environment with an 8-bit code, the use of the G0 and G2 sets, the G2 set being invoked in columns 10 to 15, where the character sets may comprise 94 and/or 96 characters and each C1 control function is represented by a single bit combination from columns 08 and 09. + +### **9.1.7 First line offset** + +CATEGORY:                             Shared + +PERMISSIBLE VALUES:           any integer + +DEFAULT VALUE:                    0 + +#### DEFINITION: + +This attribute specifies an offset along the character path from the line home position, measured in SMUs (see 7.2.8). + +The offset may be positive (in the direction of the character path), negative (in the direction opposite to the character path) or zero. + +The position identified by application of this offset to the line home position is used instead of the line home position for the purposes of formatting and imaging the first line of the basic layout object in which the content of the basic logical component is laid out. + +The value of the presentation attribute “indentation” (see 9.3.1) shall be set such that the resulting displacement of the line home position from the start edge of the positioning area is sufficient to enable overhanging characters to be imaged within the positioning area. + +The first line offset cannot be altered within the content of a basic component. + +### **9.1.8 Graphic character sets** + +CATEGORY:                             Shared + +PERMISSIBLE VALUES:           The value of this attribute consists of a string of escape sequences, in accordance with ISO 2022 and the register of ISO 2375, to designate one or more graphic character sets, and any locking shift functions needed to invoke these character sets. + +DEFAULT VALUE:                    The escapade sequences and shift functions designating and invoking the primary character set of ISO 6937-2 as the G0 set and the supplementary character set of ISO 6937-2 as the G2 set in columns 10 to 15. + +#### DEFINITION: + +This attribute specifies the graphic character set(s) designated and/or invoked at the beginning of the basic component. + +Other graphic character sets can be designated and/or invoked within the content of a basic component by means of the appropriate code extension escape sequences and shift functions. + +### **9.1.9 Graphic character subrepertoire** + +CATEGORY:                             Shared + +PERMISSIBLE VALUES:           The value of this attribute is either 0 or the identifier of a subrepertoire assigned in the register of ISO/IEC 7350. The value 0 identifies the full repertoire of the graphic character sets that are designated at the beginning of the basic component. + +DEFAULT VALUE:                    0 + +#### DEFINITION: + +This attribute identifies the subrepertoire of the graphic character repertoire of ISO 6937 used at the beginning of the basic component. + +This attribute is only applicable if the graphic character sets of ISO 6937 are used. + +Other graphic character subrepertoires can be invoked within the content of a basic component by means of the control function IGS (Identify Graphic Subrepertoire). + +### 9.1.10 Graphic rendition + +| | | +|---------------------|------------------------------------------------------------------------------------------------------------------------------| +| CATEGORY: | Shared | +| PERMISSIBLE VALUES: | A sequence of one or more integers corresponding to parameter values of the control function SGR (Select Graphic Rendition). | +| DEFAULT VALUE: | 0 | +| DEFINITION: | | + +This attribute specifies the rendition parameters for font, underlining, etc. which apply at the beginning of the basic component (see 8.1). The SGR values 30 to 37 and 40 to 47 are not permitted in this attribute. + +The graphic rendition can be altered within the content of a basic component by means of the control function SGR (Select Graphic Rendition). + +NOTE – If more than one graphic rendition parameter is encoded, then it is the user's responsibility to ensure that they are consistent. + +### 9.1.11 Itemization + +| | | +|---------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| CATEGORY: | Shared | +| STRUCTURE: | One required parameter: identifier alignment<br>Two optional parameters: identifier start offset, identifier end offset | +| PERMISSIBLE VALUES: | identifier alignment: 'no itemization', 'start-aligned', 'end-aligned'<br>identifier start offset: any integer value<br>identifier end offset: any integer value | +| DEFAULT VALUES: | identifier alignment: 'no itemization'<br>identifier start offset: the distance from the line home position to the start of the positioning area<br>identifier end offset: 0 | + +#### DEFINITION: + +This attribute specifies the placement of an item identifier which may begin the basic component (see 7.2.9). + +If the value of the parameter "identifier alignment" is 'no itemization', then no item identifier is present. + +For other values of the parameter "identifier alignment", the parameters "identifier start offset" and "identifier end offset" specify offsets, in SMUs, from the line home position along the character path which identify, respectively, the start edge and end edge of a portion of the line box in which the item identifier will be formatted. These offsets may be positive (in the direction of the character path), negative (in the direction opposite to the character path) or zero. + +The item identifier consists of all graphic characters preceding the first occurrence of the control function CR (Carriage Return) in the basic component. The content of the basic component following that CR shall be formatted as specified by the presentation attribute "first line offset". + +Values of the parameter "identifier alignment" other than 'no itemization' specify the method of character alignment for the item identifier. + +The value of the presentation attribute "indentation" (see 9.3.1) shall be set such that the resulting displacement of the line home position from the start edge of the positioning area is sufficient to enable the item identifier to be imaged within the positioning area. + +Itemization cannot be altered within the content of a basic component. + +### **9.1.12 Kerning offset** + +| | | | +|--------------------|--------------------|--------------------------------------| +| CATEGORY: | Shared | | +| STRUCTURE: | two parameters: | start edge offset<br>end edge offset | +| PERMISSIBLE VALUE: | start edge offset: | any non-negative integer | +| | end edge offset: | any non-negative integer | +| DEFAULT VALUES: | start edge offset: | 0 | +| | end edge offset: | 0 | + +#### **DEFINITION:** + +This attribute specifies the kerning offset as a pair of integer values in SMUs (see 7.1.6). The parameter “start edge offset” specifies the distance from the edge of the basic layout object to the start edge of the positioning area. The parameter “end edge offset” specifies the distance from the edge of the basic layout object to the end edge of the positioning area. + +The kerning offset cannot be altered within the content of a basic component. + +### **9.1.13 Line layout table** + +| | | | +|---------------------|--------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------| +| CATEGORY: | Shared | | +| STRUCTURE: | A set of entries where each entry consists of three required parameters: | tab reference<br>tab position<br>alignment | +| | and one optional parameter: | alignment string | +| PERMISSIBLE VALUES: | tab reference: | A string of one to four decimal digits used as the reference parameter in the control function STAB (Selective Tabulation). | +| | tab position: | any non-negative integer | +| | alignment: | ‘start-aligned’<br>‘end-aligned’<br>‘centred’<br>‘aligned-around’ | +| | alignment string: | Graphic characters from the set of graphic elements specified by the presentation attributes “graphic character sets” and “graphic character subrepertoire”. | +| DEFAULT VALUE: | The default value is such that no tabulation stop is defined. | | + +#### **DEFINITION:** + +This attribute specifies the positions and types of a set of tabulation stops (see 7.2.3). The value of the parameter “tab position” specifies the distance in SMUs, in the direction of the character path, from the start edge of the positioning area to the tabulation stop. + +If the value of the parameter “alignment” is ‘aligned-around’, then the parameter “alignment string” shall be specified otherwise this parameter shall not be specified. + +When this presentation attribute specifies any tabulation stops, the presentation attribute “alignment” is assumed to have the value ‘start-aligned’ (see 9.1.1). + +The tabulation stops cannot be altered within the content of a basic component. + +### **9.1.14 Line progression** + +CATEGORY: Shared + +PERMISSIBLE VALUES: d90 +d270 + +DEFAULT VALUE: d270 + +DEFINITION: + +This attribute specifies the line progression (see 7.1.2). + +The line progression cannot be altered within the content of a basic component. + +### **9.1.15 Line spacing** + +CATEGORY: Shared + +PERMISSIBLE VALUES: any positive integer + +DEFAULT VALUE: the equivalent of 200 BMUs + +DEFINITION: + +This attribute only applies when proportional line spacing is not to be done by the content layout process. In this case, it specifies the line spacing which applies at the beginning of the basic component (see 7.3). + +The value of this attribute is an integer specifying the distance in SMUs. + +The line spacing can be altered within the content of a basic component by means of the control functions SVS (Select Line Spacing) or SLS (Set Line Spacing). + +### **9.1.16 Pairwise kerning** + +CATEGORY: Shared + +PERMISSIBLE VALUES: 'yes' +'no' + +DEFAULT VALUE: 'no' + +DEFINITION: + +This attribute specifies whether pairwise kerning should be performed on the content during the formatting process (see 7.2.7). + +The value 'yes' indicates that the formatting process should perform, if possible, pairwise kerning on the content. + +The value 'no' specifies that pairwise kerning should not be performed on the content. + +The specification of pairwise kerning cannot be altered within the content of a basic component. + +## **9.2 Layout presentation attributes** + +### **9.2.1 Formatting indicator** + +CATEGORY: Layout + +PERMISSIBLE VALUES: 'yes' +'no' + +DEFAULT VALUE: 'no' + +DEFINITION: + +This attribute specifies whether the content of a basic component has been formatted by a content layout process or not. + +The value 'yes' indicates that the content of the basic layout component concerned contains layout control functions representing the effects of any use of the control function STAB (Selective Tabulation) or of the presentation attributes "alignment", "first line offset", "itemization" and/or "pairwise kerning" (see 14.2.1.3.1). + +The specification of alignment cannot be altered within the content of a basic component. + +NOTE – In interchange, a recipient can take advantage of this attribute only if he has a character font that is similar to that of the sender, i.e. a font that has the same width for each character as the sender's font. + +### 9.2.2 Initial offset + +| | | | | +|---------------------|-------------------------------------------------------------------------------------------------------------------------|--------------------------|---------------------| +| CATEGORY: | Layout | | | +| STRUCTURE: | two parameters: | horizontal coordinate | vertical coordinate | +| PERMISSIBLE VALUES: | horizontal coordinate: | any non-negative integer | | +| | vertical coordinate: | any non-negative integer | | +| DEFAULT VALUES: | The default values of this attribute depend on character path, line progression and line spacing as defined in Table 2. | | | + +**Table 2 – Default values of the presentation attribute "initial offset"** + +| Character path<br>(degrees) | Line progression<br>(degrees) | Horizontal<br>coordinate | Vertical<br>coordinate | +|-----------------------------------------------|-------------------------------|--------------------------|------------------------| +| d0 | d270 | 0 | S | +| | d90 | 0 | H-S | +| d90 | d270 | S | H | +| | d90 | W-S | H | +| d180 | d270 | W | H-S | +| | d90 | W | S | +| d270 | d270 | W-S | 0 | +| | d90 | S | 0 | +| W Horizontal dimension of the basic component | | | | +| H Vertical dimension of the basic component | | | | +| S Backward extent of the first line box | | | | + +#### DEFINITION: + +This attribute specifies the position of the initial point (see 7.3). + +The values of the parameters "horizontal coordinate" and "vertical coordinate" specify the horizontal and vertical coordinates, in SMUs, of the initial point relative to the top left corner of the basic component. The horizontal coordinate is measured positively from the vertical axis to the right and the vertical coordinate is measured positively from the horizontal axis downwards. + +The position of the initial point cannot be altered within the content of a basic component. + +## 9.3 Logical presentation attributes + +### 9.3.1 Indentation + +| | | +|---------------------|--------------------------| +| CATEGORY: | Logical | +| PERMISSIBLE VALUES: | any non-negative integer | +| DEFAULT VALUE: | 0 | +| DEFINITION: | | + +This attribute specifies the distance, in the direction of character path, from the start edge of the positioning area to the initial point of the basic layout object in which the content of the basic logical component is laid out (see Figure 10). The distance is specified in SMUs. + +The indentation cannot be altered within the content of a basic component. + +### 9.3.2 Orphan size + +CATEGORY: Logical +PERMISSIBLE VALUES: any positive integer +DEFAULT VALUE: 1 + +#### DEFINITION: + +This attribute only applies when the content layout process would result in the basic logical object being laid out in two or more basic layout objects; for example, at a page or frame boundary. + +The value of this attribute specifies the minimum number of lines of content that shall be placed in the first basic layout object. + +If the number of lines remaining in the first basic layout object is less than the value of this attribute, all the content is laid out in subsequent layout objects. + +### 9.3.3 Proportional line spacing + +CATEGORY: Logical +PERMISSIBLE VALUES: 'yes' +'no' +DEFAULT VALUE: 'no' + +#### DEFINITION: + +This attribute specifies how the content layout process is to determine the distance between the reference lines of two successive line boxes. + +If the value is 'yes', the line spacing is variable and the content layout process takes into account the forward extent of the first line box and the backward extent of the second line box. + +If the value is 'no', the line spacing does not depend on the content of the line boxes but is determined from values set by the presentation attribute "line spacing" or the control functions SLS (Set Line Spacing) and SVS (Select Line Spacing). + +### 9.3.4 Widow size + +CATEGORY: Logical +PERMISSIBLE VALUES: any positive integer +DEFAULT VALUE: 1 + +#### DEFINITION: + +This attribute only applies when the content layout process would result in the basic logical object being laid out in two or more basic layout objects; for example, at a page or frame boundary. + +The value of this attribute specifies the minimum number of lines of content that shall be placed in the last basic layout object. + +If the number of lines in the last basic layout object is less than the value of this attribute, sufficient lines shall be moved from the end of the previous basic layout object to meet this requirement. + +The widow size cannot be altered within the content of a basic component. + +It is possible, e.g. for short basic layout objects, that, in satisfying this requirement and the requirements of the presentation attribute "orphan size", the entire content may be removed from the first basic layout object. + +## 9.4 Content architecture class attributes + +### 9.4.1 Content architecture class + +The value of the attribute “content architecture class” of a basic component description that conforms to this part of ITU-T Rec. T.410-Series | ISO/IEC 8613 is an ASN.1 object identifier with one of the following values: + +- { 2 8 2 6 0 } for the formatted character content architecture class; +- { 2 8 2 6 1 } for the processable character content architecture class; +- { 2 8 2 6 2 } for the formatted processable character content architecture class; + +## 9.5 Interactions between presentation attributes and layout directives + +The attribute “concatenation” of the document architecture (see ITU-T Rec. T.412 | ISO/IEC 8613-2) is applicable to content portions belonging to the same character content architecture class. When concatenation is in effect, as a result of the layout directive “concatenation”, then, for the following presentation attributes + +- “alignment” +- “character fonts” +- “character orientation” +- “character path” +- “first line offset” +- “indentation” +- “itemization” +- “kerning offset” +- “line layout table” +- “line progression” +- “orphan size” +- “pairwise kerning” +- “widow size” + +any value that is specified for the first component of the concatenated sequence applies to all components in the sequence. Thus, in the case of presentation attributes, the values specified for the first component override the values for the other components in the sequence. + +# 10 Character content portion attributes + +## 10.1 Common coding attributes + +The value of the attribute “type of coding” of a content portion description that conforms to this part of ITU-T Rec. T.410-Series | ISO/IEC 8613 is an ASN.1 object identifier with the value { 2 8 3 6 0 }. + +## 10.2 Other coding attributes + +No other coding attributes are defined for content portions conforming to this part of ITU-T Rec. T.410-Series | ISO/IEC 8613. + +## 10.3 Content information + +For character content architectures, the value of this attribute is an octet string representing character coded information in accordance with this part of ITU-T Rec. T.410-Series | ISO/IEC 8613. + +# 11 Formal definitions of character content architecture dependent data types + +## 11.1 Introduction + +This clause contains the formal definitions, in ASN.1 notation (defined in CCITT Rec. X.208 | ISO/IEC 8824), of the data types that are applicable to the character content architecture. + +These data types are: + +- the data type to represent character content architecture specific presentation attributes in basic components, presentation styles and default value lists; +- the data type to represent character content architecture coding attributes in content portions; +- the data type to represent non-basic values of the character content architecture presentation attributes in the document profile; +- the data type to represent non-basic values of the character content architecture coding attributes in the document profile; +- the data type to represent non-standard default values of the character content architecture presentation and coding attributes in the document profile. + +## 11.2 Representation of presentation attributes + +The data type “Character-Attributes” contains a set of subordinate data types that specify the character presentation attributes. Some of these subordinate data types are elementary but others are structured and are themselves made up of subordinate data types. The format of these data types is given below. + +The subset of subordinate data types that may occur within a particular instance of the data type “Character-Attributes” depends upon a document application profile that is specified, using the rules specified in ITU-T Rec. T.411 | ISO/IEC 8613-1.Character-Presentation-Attributes { 2 8 1 6 2 } + +**DEFINITIONS ::= BEGIN** + +**EXPORTS**            **Character-Attributes,** +                      **One-Of-Four-Angles,** +                      **One-Of-Two-Angles,** +                      **Measure-Pair,** +                      **Alignment,** +                      **Layout-Table,**Error! Bookmark not defined. +                      **Graphic-Rendition,** +                      **formatting-Indicator,** +                      **character-Fonts,** +                      **itemization,** +                      **kerning-Offset,** +                      **proportional-Line-Spacing,** +                      **pairwise-Kerning;** + +| | | | +|-----------------------------|-------------|------------------------------------------------| +| <b>Character-Attributes</b> | <b>::=</b> | <b>SET {</b> | +| character-path | <b>[0]</b> | <b>IMPLICIT One-Of-Four-Angles OPTIONAL,</b> | +| line-progression | <b>[1]</b> | <b>IMPLICIT One-Of-Two-Angles OPTIONAL,</b> | +| character-orientation | <b>[2]</b> | <b>IMPLICIT One-Of-Four-Angles OPTIONAL,</b> | +| initial-offset | <b>[3]</b> | <b>IMPLICIT Measure-Pair OPTIONAL,</b> | +| character-spacing | <b>[6]</b> | <b>IMPLICIT INTEGER OPTIONAL,</b> | +| line-spacing | <b>[7]</b> | <b>IMPLICIT INTEGER OPTIONAL,</b> | +| alignment | <b>[8]</b> | <b>IMPLICIT Alignment OPTIONAL,</b> | +| line-layout-table | <b>[9]</b> | <b>IMPLICIT Layout-Table OPTIONAL,</b> | +| graphic-rendition | <b>[10]</b> | <b>IMPLICIT Graphic-Rendition OPTIONAL,</b> | +| formatting-indicator | <b>[11]</b> | <b>IMPLICIT Formatting-Indicator OPTIONAL,</b> | +| character-fonts | <b>[12]</b> | <b>IMPLICIT Character-Fonts OPTIONAL,</b> | +| graphic-char-subrepertoire | <b>[13]</b> | <b>IMPLICIT INTEGER OPTIONAL,</b> | +| itemization | <b>[14]</b> | <b>IMPLICIT Itemization OPTIONAL,</b> | + +| | | | +|----------------------------|------|-------------------------------------------------------------------------------------| +| widow-size | [15] | IMPLICIT INTEGER OPTIONAL, | +| orphan-size | [16] | IMPLICIT INTEGER OPTIONAL, | +| graphic-character-sets | [17] | IMPLICIT OCTET STRING OPTIONAL, | +| indentation | [19] | IMPLICIT INTEGER OPTIONAL, | +| kerning-offset | [20] | IMPLICIT Kerning-Offset OPTIONAL, | +| proportional-line-spacing | [21] | IMPLICIT Proportional-Line-Spacing OPTIONAL, | +| pairwise-kerning | [22] | IMPLICIT Pairwise-Kerning OPTIONAL, | +| first-line-offset | [23] | IMPLICIT INTEGER OPTIONAL, | +| code-extension-announcers | [24] | IMPLICIT OCTET STRING OPTIONAL } | +| One-of-Four-Angles | ::= | INTEGER { d0 (0),<br>d90 (1),<br>d180 (2),<br>d270 (3) } | +| One-of-Two-Angles | ::= | INTEGER { d90 (1),<br>d270 (3) } | +| Measure-Pair | ::= | SEQUENCE { | +| horizontal | | [0] IMPLICIT INTEGER, | +| vertical | | [1] IMPLICIT INTEGER } | +| Alignment | ::= | INTEGER { start-aligned (0),<br>end-aligned (1),<br>centred (2),<br>justified (3) } | +| Layout-Table | ::= | SET OF Tabulation-Stop | +| Tabulation-Stop | ::= | SET { | +| tabulation-reference | | [0] IMPLICIT NumericString, | +| tabulation-position | | [1] IMPLICIT INTEGER, | +| alignment | | [2] IMPLICIT INTEGER { | +| | | start-aligned (0), | +| | | end-aligned (1), | +| | | centred (2), | +| | | aligned-around (3) }, | +| alignment-character-string | [3] | IMPLICIT OCTET STRING OPTIONAL } | +| | | -- <i>string of graphic characters</i> | +| | | -- <i>from the set of graphic elements</i> | +| | | -- <i>specified by the presentation</i> | +| | | -- <i>attributes "graphic character</i> | +| | | -- <i>sets" and "graphic character</i> | +| | | -- <i>subrepertoire"</i> | +| Graphic-Rendition | ::= | SET OF Graphic-Rendition-Aspect | +| Character-Fonts | ::= | SET { | +| primary-font | | [0] IMPLICIT Font-Type OPTIONAL, | +| first-alternative-font | | [1] IMPLICIT Font-Type OPTIONAL, | +| second-alternative-font | | [2] IMPLICIT Font-Type OPTIONAL, | +| third-alternative-font | | [3] IMPLICIT Font-Type OPTIONAL, | +| fourth-alternative-font | | [4] IMPLICIT Font-Type OPTIONAL, | +| fifth-alternative-font | | [5] IMPLICIT Font-Type OPTIONAL, | +| sixth-alternative-font | | [6] IMPLICIT Font-Type OPTIONAL, | +| seventh-alternative-font | | [7] IMPLICIT Font-Type OPTIONAL, | +| eighth-alternative-font | | [8] IMPLICIT Font-Type OPTIONAL, | +| ninth-alternative-font | | [9] IMPLICIT Font-Type OPTIONAL } | +| Font-Type | ::= | SET { | +| font-size | | [0] IMPLICIT INTEGER, | +| font-identifier | | [1] IMPLICIT INTEGER } | +| Graphic-Rendition-Aspect | ::= | INTEGER { | +| cancel | | (0), | + +| | | +|-------------------------------|---------------------------------| +| increased-intensity | (1), | +| decreased-intensity | (2), | +| italicized | (3), | +| underlined | (4), | +| slowly-blinking | (5), | +| rapidly-blinking | (6), | +| negative-image | (7), | +| crossed-out | (9), | +| primary-font | (10), | +| first-alternative-font | (11), | +| second-alternative-font | (12), | +| third-alternative-font | (13), | +| fourth-alternative-font | (14), | +| fifth-alternative-font | (15), | +| sixth-alternative-font | (16), | +| seventh-alternative-font | (17), | +| eighth-alternative-font | (18), | +| ninth-alternative-font | (19), | +| doubly-underlined | (21), | +| normal-intensity | (22), | +| not-italicized | (23), | +| not-underlined | (24), | +| steady | (25), | +| variable-spacing | (26), | +| positive-image | (27), | +| not-crossed-out | (29), | +| black-foreground | (30), | +| red-foreground | (31), | +| green-foreground | (32), | +| yellow-foreground | (33), | +| blue-foreground | (34), | +| magenta-foreground | (35), | +| cyan-foreground | (36), | +| white-foreground | (37), | +| select-char-foreground-colour | (38), | +| black-background | (40), | +| red-background | (41), | +| green-background | (42), | +| yellow-background | (43), | +| blue-background | (44), | +| magenta-background | (45), | +| cyan-background | (46), | +| white-background | (47), | +| select-char-background-colour | (48), | +| not-variable-spacing | (50) } | +| Formatting-Indicator | ::= INTEGER { no (0), yes (1) } | +| Itemization | ::= SET { | +| identifier-alignment | [0] IMPLICIT INTEGER { | +| | no-itemization (0), | +| | start-aligned (1), | +| | end-aligned (2) } | +| identifier-start-offset | [1] IMPLICIT INTEGER OPTIONAL, | +| identifier-end-offset | [2] IMPLICIT INTEGER OPTIONAL } | +| Kerning-Offset | ::= SET { | +| start-offset | [0] IMPLICIT INTEGER, | +| end-offset | [1] IMPLICIT INTEGER } | +| Proportional-Line-Spacing | ::= INTEGER { no (0), yes (1) } | +| Pairwise-Kerning | ::= INTEGER { no (0), yes (1) } | +| END | | + +## 11.3 Representation of coding attributes + +Character-Coding-Attributes { 2 8 1 6 3 } + +DEFINITIONS ::= BEGIN + +``` +EXPORTS Character-Coding-Attributes; + Character-Coding-Attributes ::=SET { } + -- no character coding attributes + -- are defined in this part of + -- ITU-T Rec. T.410-Series | ISO/IEC 8613 +``` + +END + +## 11.4 Representation of non-basic features and non-standard defaults + +Character-Profile-Attributes { 2 8 1 6 4 } + +DEFINITIONS ::= BEGIN + +``` +EXPORTS Character-Presentation-Feature, + Character-Coding-Attribute, + Character-Content-Defaults; + +IMPORTS Character-Attributes, + One-Of-Four-Angles, + One-Of-Two-Angles, + Measure-Pair, + Alignment, + Layout-Table, + Graphic-Rendition, + Formatting-Indicator, + Character-Fonts + Itemization, + Kerning-Offset, + Proportional-Line-Spacing, + Pairwise-Kerning + FROM Character-Presentation-Attributes; +``` + +-- see 11.2 + +``` +Character-Presentation-Feature ::=CHOICE { + character-path [0] IMPLICIT One-Of-Four-Angles, + line-progression [1] IMPLICIT One-Of-Two-Angles, + character-orientation [2] IMPLICIT One-Of-Four-Angles, + initial-offset [3] IMPLICIT Measure-Pair, + character-spacing [6] IMPLICIT INTEGER, + line-spacing [7] IMPLICIT INTEGER, + alignment [8] IMPLICIT Alignment, + line-layout-table [9] IMPLICIT Layout-Table, + graphic-rendition [10] IMPLICIT Graphic-Rendition, + formatting-indicator [11] IMPLICIT Formatting-Indicator, + character-fonts [12] IMPLICIT Character-Fonts, + graphic-char-subrepertoire [13] IMPLICIT INTEGER, + itemization [14] IMPLICIT Itemization, + widow-size [15] IMPLICIT INTEGER, + orphan-size [16] IMPLICIT INTEGER, + graphic-character-sets [17] IMPLICIT OCTET STRING, + indentation [19] IMPLICIT INTEGER, + kerning-offset [20] IMPLICIT Kerning-Offset, + proportional-line-spacing [21] IMPLICIT Proportional-Line-Spacing, + pairwise-kerning [22] IMPLICIT Pairwise-Kerning, +``` + +| | | +|-----------------------------------|--------------------------------------------------| +| <b>first-line-offset</b> | <b>[23] IMPLICIT INTEGER,</b> | +| <b>code-extension-announcers</b> | <b>[24] IMPLICIT OCTET STRING }</b> | +| <b>Character-Coding-Attribute</b> | <b>::=NULL</b> | +| | -- <i>no character coding attributes</i> | +| | -- <i>are defined in this part of</i> | +| | -- <i>ITU-T Rec. T.410-Series ISO/IEC 8613</i> | +| <b>Character-Content-Defaults</b> | <b>::=Character-Attributes</b> | +| <b>END</b> | | + +# 12 Graphic Characters + +The set of graphic characters used in the content of a basic component, and their coded representations, are specified by the presentation attributes “Graphic character sets” and “Graphic character subrepertoire” and the associated control functions, that is, the code extension control functions and the control function Identify Graphic Subrepertoire (IGS) as follows: + +- “graphic character sets” – This presentation attribute specifies the graphic character sets designated and/or invoked at the beginning of the basic component. The specification of the graphic character sets by this attribute implies the definition of a repertoire of graphic characters and of a unique coded representation for each character of that repertoire; +- “graphic character subrepertoire” – This presentation attribute can be used, when the graphic character sets designated are those of ISO 6937, to restrict the repertoire of graphic characters to a subset of the repertoire implied by the specification of the graphic character sets. Use of this attribute does not affect the coded representations of the graphic characters; +- code extension control functions – These control functions can be used within the content of a basic component to alter the designations and/or invocations of graphic character sets from those specified by the presentation attribute “graphic character sets”; +- Identify Graphic Subrepertoire (IGS) – This control function can be used within the content of a basic component, when the graphic character sets designated are those of ISO 6937, to alter the subrepertoire from that specified by the presentation attribute “graphic character subrepertoire”. + +When the presentation attributes “graphic character sets” and “graphic character subrepertoire” are not specified for a basic component, their values are determined using the defaulting mechanism defined in ITU-T Rec. T.412 | ISO/IEC 8613-2, as for any other presentation attribute. + +# 13 Definition of control functions and the character SPACE + +Control functions are classified in the following four categories: + +- Shared control functions, including code extension control functions, which are available to all classes of character content architecture; +- Layout control functions which are available only to formatted form and formatted processable form character content architectures; +- Logical control functions which are available only to processable form and formatted processable form character content architectures; +- Delimiters which are used to delimit graphic characters and/or shared control functions introduced as a result of a formatting process. The delimiters are available only to formatted processable form character content architectures. + +The control functions in these four categories are defined in 13.1 to 13.4 respectively; subclause 13.5 defines the character SPACE. The allocation of control functions to categories is summarized in Table 3. + +Control functions that have not been included explicitly in this clause are: + +- the sequence introducers Escape (ESC) and Control Sequence Introducer (CSI) that are permitted to be used in the character content architecture when required to represent a graphic character or a control function; +- line terminators: + - 1) A soft line terminator is represented by the control function Carriage Return (CR) then Line Feed (LF) in that order, where the CR and LF are enclosed between a pair of delimiters Start of String (SOS) and String Terminator (ST); + - 2) A hard line terminator is represented by a control function Line Feed (LF) that immediately follows either a control function Carriage Return (CR) or another LF where the entire sequence of CR and LF(s) is NOT enclosed between a pair of delimiters Start of String (SOS) and String Terminator (ST). + +**Table 3 – Control functions** + +| | | +|---------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Shared control functions | CR Carriage Return<br>GCC Graphic Character Composition<br>IGS Identify Graphic Subrepertoire<br>LF Line Feed<br>PLD Partial Line Up<br>PLU Partial Line Down<br>SCS Set Character Spacing<br>SGR Select Graphic Rendition<br>SHS Select Character Spacing<br>SLS Set Line Spacing<br>SRS Start Reverse String<br>STAB Selective Tabulation<br>SUB Substitute Character<br>SVS Select Line Spacing<br>VPB Line Position Backward<br>VPR Line Position Relative<br>Code extension control functions | +| Layout control functions | BS Backspace<br>HPB Character Position Backward<br>HPR Character Position Relative<br>JFY No Justify<br>SACS Set Additional Character Separation<br>SRCS Set Reduced Character Separation<br>SSW Set SPACE Width | +| Logical control functions | BPH Break Permitted Here<br>NBH No Break Here<br>PTX Parallel Texts | +| Delimiters | SOOS (Start of Original String)<br>SOS (Start of String)<br>ST String Terminator | + +## 13.1 Shared control functions + +### 13.1.1 Carriage Return (CR) + +A control function which causes the active position to be moved to the line home position but not to be moved in the direction of line progression. + +NOTE – CR is used in conjunction with the control function LF (Line Feed) to move the active position to the line home position at the beginning of a new line of text. It is also used to move the active position to the line home position. For example, after an item identifier (see 9.1.11). CR should not be used to cause character images to be superimposed. + +### **13.1.2 Graphic Character Composition (GCC)** + +A control function with one optional parameter which specifies that two or more graphic characters are to be combined into one graphic symbol. + +The value of the parameter is 0, 1 or 2. + +GCC with the parameter value 0 indicates that the two following graphic characters are to be presented as a single symbol. + +GCC with the parameter value 1 indicates the start and GCC with the parameter value 2 indicates the end of a string of graphic characters that are to be presented as a single symbol. + +If no parameter value is specified the parameter value is assumed to be 0. + +### **13.1.3 Identify Graphic Subrepertoire (IGS)** + +A control function with one optional selective parameter which is used to indicate that a subrepertoire of the graphic character repertoire of ISO 6937 is used in the subsequent text. All graphic character sets that are used to represent the indicated graphic character subrepertoire shall be explicitly designated, but need not be invoked, prior to the occurrence of IGS. + +The identification of the graphic character subrepertoire may be changed at any point within a document and becomes effective immediately. No graphic characters other than those of the specified subrepertoire shall be used in the text following the occurrence of IGS. The effect of a graphic character subrepertoire identification ceases upon the next occurrence of + +- another IGS; +- the end of the current basic object; +- the designation of any graphic character set. + +If no parameter value is specified the parameter value is assumed to be 0. + +A non-zero parameter value is the identifier assigned to a subrepertoire of the repertoire of ISO 6937 in accordance with the registration procedure specified in ISO/IEC 7350. + +The parameter value zero identifies the entire repertoire of the currently designated graphic character sets. + +In the absence of IGS, the subrepertoire identified by the presentation attribute “graphic character subrepertoire” applies or the entire repertoire of the currently designated graphic character sets otherwise. + +NOTE – The use of IGS in document application profiles based on ISO/IEC 8613 is deprecated. IGS is included in this part of ITU-T Rec. T.410-Series | ISO/IEC 8613 only for compatibility with some existing applications such as those based upon Recommendation T.61 (1984). + +### **13.1.4 Line Feed (LF)** + +A control function which causes the active position to be advanced in the direction of line progression but not to be moved in the direction of the character path. As a result, in the content layout process, the current line box is terminated and a new line box is started. The amount of movement is that specified by the most recent occurrence either of the control functions Set Line Spacing (SLS) or Select Line Spacing (SVS) if any, or otherwise by the presentation attribute “line spacing”. + +LF is restricted to be used in the following cases: + +- at the beginning of the content of a basic layout component; +- immediately following a control function Carriage Return (CR); +- immediately following another LF. + +### 13.1.5 Partial Line Down (PLD) + +A control function which causes either the start of subscript rendition or the end of superscript rendition of graphic characters. + +When superscript rendition is in effect, it is terminated by PLD; otherwise, subscript rendition is initiated by PLD. + +Any occurrence of PLD to start subscript rendition shall be followed by a control function PLU (Partial Line Up) in the same line before another PLD or control function LF (Line Feed) is used. + +PLD does not affect the position of any (graphic) lines used to implement the graphic rendition “underlined”, “crossed-out”, or “doubly underlined” when such a graphic rendition is in effect prior to the occurrence of PLD. + +#### NOTES + +- The implementation of the subscript rendition initiated by PLD may be accomplished with special character fonts and/or movement of the active position not exceeding a half line space. + +- The graphic rendition “underlined” may have been effected, prior to the occurrence of PLD, either by the control function Select Graphic Rendition (SGR) or by the non-spacing underline character (see ISO 6937). + +### 13.1.6 Partial Line Up (PLU) + +A control function which causes either the start of superscript rendition or the end of subscript rendition of graphic characters. + +When subscript rendition is in effect, it is terminated by PLU; otherwise, superscript rendition is initiated by PLU. + +Any occurrence of PLU to start superscript rendition shall be followed by a control function PLD (Partial Line Down) in the same line before another PLU or control function LF (Line Feed) is used. + +PLU does not affect the position of any (graphic) lines used to implement the graphic rendition “underlined”, “crossed-out” or “doubly underlined” when such a graphic rendition is in effect prior to the occurrence of PLU. + +#### NOTES + +- The implementation of the superscript rendition initiated by PLU may be accomplished with special character fonts and/or movement of the active position not exceeding a half line space. + +- The graphic rendition “underlined” may have been affected, prior to the occurrence of PLU, either by the control function SGR (Select Graphic Rendition) or by the non-spacing underline character (see ISO 6937). + +### 13.1.7 Set Character Spacing (SCS) + +A control function with one optional numeric parameter which specifies the character spacing to be applied to constant spacing fonts in subsequent text. + +The specified character spacing takes effect immediately and remains in effect until it is changed by a subsequent occurrence of either SCS or the control function Select Character Spacing (SHS) in the current basic component. + +The character spacing is expressed as an integral multiple of SMUs. + +If no parameter value is specified the parameter value is assumed to be the equivalent of 120 BMUs. + +### 13.1.8 Select Graphic Rendition (SGR) + +A control function with zero, one or more selective parameters which specify one or more graphic rendition aspects for graphic characters and space characters in the subsequent text. The specified graphic rendition(s) takes effect immediately and remains in effect until a subsequent occurrence of SGR in the basic object. + +The meaning of the parameter values is shown in Table 4. + +If no parameter value is specified the parameter value is assumed to be 0. + +Any graphic rendition aspect specified by an occurrence of SGR, apart from the exceptions specified below, is combined with the graphic rendition aspects that are in effect prior to that occurrence of SGR as a result of either an earlier occurrence of SGR or the presentation attribute “graphic rendition” of the current basic object. + +Table 4 – Parameter values for SGR + +| Value | Meaning | +|-------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 0 | Default rendition (implementation-defined); cancels the effect of any preceding occurrence of SGR and cancels the effect of the presentation attribute “graphic rendition”; invokes the primary font, character foreground and character background colour | +| 1 | Bold or increased intensity | +| 2 | Faint or decreased intensity | +| 3 | Italicized | +| 4 | Underlined | +| 5 | Slowly blinking | +| 6 | Rapidly blinking | +| 7 | Negative image | +| 9 | Crossed-out (characters still legible but marked as to be deleted) | +| 10 | Primary (default) font | +| 11 | First alternative font | +| 12 | Second alternative font | +| 13 | Third alternative font | +| 14 | Fourth alternative font | +| 15 | Fifth alternative font | +| 16 | Sixth alternative font | +| 17 | Seventh alternative font | +| 18 | Eighth alternative font | +| 19 | Ninth alternative font | +| 21 | Doubly underlined | +| 22 | Normal intensity (neither bold nor faint) | +| 23 | Not italicized | +| 24 | Not underlined (neither singly nor doubly) | +| 25 | Steady (not blinking) | +| 26 | Variable spacing | +| 27 | Positive image | +| 29 | Not crossed-out | +| 30 | Black foreground | +| 31 | Red foreground | +| 32 | Green foreground | +| 33 | Yellow foreground | +| 34 | Blue foreground | +| 35 | Magenta foreground | +| 36 | Cyan foreground | +| 37 | White foreground | +| 38 | Select character foreground colour | +| 40 | Black background | +| 41 | Red background | +| 42 | Green background | +| 43 | Yellow background | +| 44 | Blue background | +| 45 | Magenta background | +| 46 | Cyan background | +| 47 | White background | +| 48 | Select character background colour | +| 50 | Not variable spacing | + +When SGR is used to start underlining (singly or doubly), or crossing out, within the scope of subscript or superscript rendition (see 13.1.5 and 13.1.6), any lines used to implement such a graphic rendition are lowered or raised in order that the graphic rendition concerned applies to the subscript or superscript characters. + +The default parameter value cannot be used in combination with any other parameter value. + +When a designated font is invoked, any specification of weight or posture by an SGR parameter value is ignored. This applies to the parameter values 1, 2, 3, 22 and 23. These parameter values are enabled when a primary or alternative font is invoked for which no designation has been made. + +#### NOTES + +- 1 Several parameter values can be used in combination, in order to obtain, for example, underlined italics. +- 2 The use of parameter values 26 and 50 in document application profiles based on ISO/IEC 8613 is deprecated. + +These values are included in this Specification only for compatibility with some existing applications such as those based upon Recommendation T.61 (1984). + +The values 30 to 37 and 40 to 47 are interpreted as indexes into the colour table specified in the attribute “content colour table” applying to the object to which the content is associated. This attribute is defined in ITU-T Rec. T.412 | ISO/IEC 8613-2. The values are associated with indexes as follows: + +| SGR values | Entry in default colour table | +|------------|-------------------------------| +| 30 and 40 | index 1 | +| 31 and 41 | index 2 | +| 32 and 42 | index 3 | +| 33 and 43 | index 4 | +| 34 and 44 | index 5 | +| 35 and 45 | index 6 | +| 36 and 46 | index 7 | +| 37 and 47 | index 0 | + +The parameter values 38 and 48 are followed by a parameter substring used to select either the character foreground “colour value” or the character background “colour value”. + +A parameter substring for values 38 or 48 may be divided by one or more separators (03/10) into parameter elements, denoted as Pe. The format of such a parameter sub-string is indicated as: + +Pe : P ... + +Each parameter element consists of zero, one or more bit combinations from 03/00 to 03/09, representing the digits 0 to 9. An empty parameter element represents a default value for this parameter element. Empty parameter elements at the end of the parameter substring need not be included. + +The first parameter element indicates a choice between: + +- 0 implementation defined (only applicable for the character foreground colour) +- 1 transparent; +- 2 direct colour in RGB space; +- 3 direct colour in CMY space; +- 4 direct colour in CMYK space; +- 5 indexed colour. + +If the first parameter has the value 0 or 1, there are no additional parameter elements. + +If the first parameter element has the value 5, then there is a second parameter element specifying the index into the colour table given by the attribute “content colour table” applying to the object with which the content is associated. + +If the first parameter element has the value 2, 3, or 4, the second parameter element specifies a colour space identifier referring to a colour space definition in the document profile. + +If the first parameter element has the value 2, the parameter elements 3, 4, and 5, are three integers for red, green, and blue colour components. Parameter 6 has no meaning. + +If the first parameter has the value 3, the parameter elements 3, 4, and 5 and three integers for cyan, magenta, and yellow colour components. Parameter 6 has no meaning. + +If the first parameter has the value 4, the parameter elements 3, 4, 5, and 6, are four integers for cyan, magenta, yellow, and black colour components. + +If the first parameter element has the value 2, 3, or 4, the parameter element 7 may be used to specify a tolerance value (an integer) and the parameter element 8 may be used to specify a colour space associated with the tolerance (0 for CIELUV, 1 for CIELAB). + +NOTE 3 – The “colour space id” component will refer to the applicable colour space description in the document profile which may contain colour scaling data that describe the scale and offset to be applied to the specified colour components in the character content. Appropriate use of scaling and offsets may be required to map all colour values required into the integer encoding space provided. This may be particularly important if concatenated content requires the insertion of such SGR sequences by the content layout process. + +### 13.1.9 Select Character Spacing (SHS) + +A control function with one optional selective parameter which specifies the character spacing to be applied to constant spacing fonts in subsequent text. + +The specified character spacing remains in effect until it is changed by a subsequent occurrence of either SHS or the control function Set Character Spacing (SCS) in the current basic object. + +The meaning of the parameter value is: + +- 0 120 BMUs; +- 1 100 BMUs; +- 2 80 BMUs; +- 3 200 BMUs; +- 4 400 BMUs. + +If no parameter value is specified the parameter value is assumed to be 0. + +### 13.1.10 Set Line Spacing (SLS) + +A control function with one optional numeric parameter which specifies the line spacing for subsequent text. + +The specified line spacing takes effect immediately and remains in effect until it is changed by a subsequent occurrence of either SLS or the control function Select Line Spacing (SVS) in the current basic component. + +The line spacing is expressed as an integral multiple of SMUs. + +If no parameter value is specified the parameter value is assumed to be the equivalent of 200 BMUs. + +### 13.1.11 Start Reverse String (SRS) + +A control function with one optional selective parameter which is used to indicate either the start or end of a string of graphic characters that are to be imaged in the direction opposite to that of the immediately preceding text (see 7.2.4). + +SRS with parameter value 1 indicates the start of the string. + +SRS with parameter value 0 indicates the end of the string. + +If no parameter value is specified the parameter value is assumed to be 0. + +Hard and soft line terminators shall not be used between SRS 1 and SRS 0. + +Any occurrence of the control functions Partial Line Down (PLD), Partial Line Up (PLU), Line Position Backward (VPB) or Line Position Relative (VPR) within the string of characters delimited by SRS 1 and SRS 0 shall be matched by an occurrence of the opposite control function within the string. + +Strings delimited by SRS may be nested. + +### 13.1.12 Selective Tabulation (STAB) + +A control function with one optional selective parameter which references a tabulation stop position in an associated "line layout table" (see 9.1.13). + +This control function specifies the positioning of the subsequent text, until either the occurrence of another STAB or the end of the current line. + +This text is to be positioned at the referenced tabulation stop and aligned in accordance with the properties specified for that tabulation stop. + +If no parameter value is specified the parameter value is assumed to be a reference to the next tabulation stop position. + +### 13.1.13 Substitute Character (SUB) + +A control function which is used in the place of a character that has been found invalid or in error. + +### **13.1.14 Select Line Spacing (SVS)** + +A control function with one optional selective parameter which specifies the line spacing for subsequent text. The specified line spacing takes effect immediately and remains in effect until it is changed by a subsequent occurrence of either SVS or the control function Set Line Spacing (SLS) in the current basic object. + +The meaning of the parameter value is: + +- 0 200 BMUs; +- 1 300 BMUs; +- 2 400 BMUs; +- 3 100 BMUs; +- 4 150 BMUs; +- 9 600 BMUs. + +If no parameter value is specified the parameter value is assumed to be 0. + +### **13.1.15 Line Position Backward (VPB)** + +A control function with one optional numeric parameter which causes the active position to be moved in the opposite direction to the line progression the number of SMUs specified by the parameter. + +The combined effect of all occurrences of the control functions VPB and Line Position Relative (VPR) within a given line shall be such that the active position is returned to the reference line before the occurrence of a hard or soft line terminator. + +If no parameter value is specified the parameter value is assumed to be the equivalent of 100 BMUs. + +NOTE – The main purposes of VPB are to provide for positioning of parallel annotation and for explicit control for the positioning of superscripts. + +### **13.1.16 Line Position Relative (VPR)** + +A control function with one optional numeric parameter which causes the active position to be moved in the direction of line progression the number of SMUs specified by the parameter. + +The combined effect of all occurrences of the control functions Line Position Backward (VPB) and VPR within a given line shall be such that the active position is returned to the reference line before the occurrence of a hard or soft line terminator. + +If no parameter value is specified the parameter value is assumed to be the equivalent of 100 BMUs. + +NOTE - The main purposes of VPR are to provide for positioning of parallel annotation and for explicit control for the positioning of subscripts. + +### **13.1.17 Code extension control functions** + +This is a category of control functions used for the designation and invocation of graphic character sets. They are defined in ISO 6429 and their use is defined in ISO 2022. + +## **13.2 Layout control functions** + +### **13.2.1 Backspace (BS)** + +A control function that causes the active position to be moved, in the direction opposite to the character path, a distance specified by the most recent occurrence of either of the control functions Select Character Spacing (SHS) or Set Character Spacing (SCS), if any, or otherwise by the presentation attribute “character spacing”. The control function Set SPACE Width (SSW) has no effect on BS. + +NOTE – BS allows for the positioning of item identifiers (see 7.2.9) on systems which do not implement the control function Character Position Backward (HPB). It is included in this Specification only for compatibility with Recommendation T.61 (1984). Its use in other document application profiles based upon ITU-T Rec. T.410-Series | ISO/IEC 8613 is deprecated. It should not be used to cause character images to be superimposed. + +### **13.2.2 Character Position Backward (HPB)** + +A control function with one optional numeric parameter which causes the active position to be moved in the opposite direction to the character path the number of SMUs specified by the parameter. + +If no parameter value is specified the parameter value is assumed to be the equivalent of 120 BMUs. + +NOTE - The main purposes of HPB are to move the active position backwards from the line home position, and to provide for the positioning of parallel annotation. + +### **13.2.3 Character Position Relative (HPR)** + +A control function with one optional numeric parameter which causes the active position to be moved in the direction of the character path the number of SMUs specified by the parameter. + +If no parameter value is specified the parameter value is assumed to be the equivalent of 120 BMUs. + +#### NOTES + +- 1 Although HPR has a control effect similar to that of one or more space characters, it does not have the graphic equivalence of space characters. Therefore, HPR does not cause spaces to be imaged in accordance with the current graphic rendition, such as underlined, possibly specified by a preceding occurrence of the control function Select Graphic Rendition (SGR). + +- 2 HPR also provides for the positioning of parallel annotation. + +### **13.2.4 No Justify (JFY)** + +A control function with one optional selective parameter which is used at the beginning of a line to indicate that the line must not be justified. It has no effect on subsequent lines. + +The meaning of the parameter value is: + +0 no justification + +If no parameter value is specified the parameter value is assumed to be 0. + +### **13.2.5 Set Additional Character Separation (SACS)** + +A control function with one optional numeric parameter which specifies increased escapement between graphic characters in subsequent text i.e. a positive value for the inter-character space (see 7.2.1). + +The specified value applies after the first subsequent graphic character and remains in effect until the next occurrence of SACS or a control function Set Reduced Character Separation (SRCS) or until it is reset to 0 by a subsequent occurrence of a hard or soft line terminator. + +The parameter value is expressed in SMUs. + +If no parameter value is specified the parameter value is assumed to be 0. + +### **13.2.6 Set Reduced Character Separation (SRCS)** + +A control function with one optional numeric parameter which specifies reduced escapement between graphic characters in subsequent text i.e. a negative value for the inter-character space (see 7.2.1). + +The specified value applies after the first subsequent graphic character and remains in effect until the next occurrence of SRCS or a control function Set Additional Character Separation (SACS) or until it is reset to 0 by a subsequent occurrence of a hard or soft line terminator. + +The parameter value is expressed in SMUs. + +If no parameter value is specified the parameter value is assumed to be 0. + +### **13.2.7 Set SPACE Width (SSW)** + +A control function with one optional numeric parameter which specifies the character escapement associated with the character SPACE for subsequent text. The specified value takes effect immediately and remains in effect until it is changed by a subsequent occurrence of SSW or reset to the default value by a subsequent occurrence of a hard or soft line terminator. + +The parameter value is expressed in SMUs. + +If no parameter value is specified the parameter value is assumed to be equal to the character spacing if the current font has constant spacing. Otherwise it is determined by the font in use. + +## 13.3 Logical control functions + +### 13.3.1 Break Permitted Here (BPH) + +A control function which indicates a point where a line break may occur when text is formatted (see 14.2.1.3.2). + +### 13.3.2 No Break Here (NBH) + +A control function which indicates a point where no line break may occur when text is formatted (see 14.2.1.3.2). + +NOTE - The graphic character No Break SPace (NBSP) should be taken to be equivalent to SPACE followed by NBH. + +### 13.3.3 Parallel Texts (PTX) + +A control function with one optional selective parameter which delimits passages of text which are interchanged one after the other, but which are intended to be presented in parallel with one another (see 7.2.5). + +The meaning of the parameter values are: + +- 0 end of parallel texts +- 1 start of principal text +- 3 start of supplementary text (e.g. Japanese Ruby annotation). + +If no parameter value is specified the parameter value is assumed to be 0. + +PTX with parameter value 1 is the opening delimiter of the first (principal) of two passages of text intended to be presented in parallel with one another. + +PTX with parameter value 3 is the closing delimiter of the first passage of text and the opening delimiter of the second (supplementary) passage intended to be presented in parallel with the first. + +PTX with parameter value 0 indicates the end of the supplementary passage of text. + +NOTE – Japanese Ruby permits the specification of exactly one supplementary passage of text. + +## 13.4 Delimiters + +### 13.4.1 Start Of Original String (SOOS) + +A control function that acts as the opening delimiter of a string of graphic characters and/or control functions that is marked to facilitate its reintroduction by a subsequent editing or content layout process. The string is closed by either an intermediate control function Start of String (SOS) or the terminating delimiter control function String Terminator (ST), whichever occurs earlier in the content. If the string is closed by an SOS control function, the latter is interpreted as the opening delimiter of a string as defined in 13.4.2. + +The string thus delimited may contain occurrences of graphic characters and control functions, in particular parts of a word subject to hyphenation, that have been removed from the content as a result of a formatting process (see 14.2.1.3). + +### 13.4.2 Start Of String (SOS) + +A control function that acts as the opening delimiter of a string of graphic characters and/or control functions that is marked to facilitate its removal by a subsequent content layout process. The string is closed by the terminating delimiter control function String Terminator (ST). + +A string thus delimited may contain occurrences of graphic characters and control functions, in particular Carriage Return (CR), Line Feed (LF) and HYPHEN, introduced as a result of a formatting process (see 14.2.1.3). + +### 13.4.3 String Terminator (ST) + +A control function that acts as the terminating delimiter of a string opened by the delimiter control function Start of String (SOS) or Start of Original String (SOOS). + +## 13.5 SPACE (SP) + +A character with properties of both a graphic character and a logical control function. + +As a control function, SP is significant to the content layout process. It acts as a word delimiter and indicates a potential line break point except when it is immediately followed by another SP or by an occurrence of the control function No Break Here (NBH) (see 13.3.2). + +As a graphic character, SP causes the active position to be advanced without a graphic symbol to be imaged. However, any graphic renditions that are in effect, e.g. underlining, also apply to SP. + +Any SP(s) that precede a line terminator after the last graphic character of a line, are ignored by the imaging process. + +# **14 Content layout process** + +This clause describes a content layout process for basic logical objects associated with content architecture of type character. + +Its purpose is to aid understanding of the semantics of the presentation attributes by describing the required results of such a process. However, it is not intended to specify any process that might be carried out in a particular implementation to achieve these results. + +## **14.1 Introduction** + +### **14.1.1 Purpose** + +The content layout process defines a process of formatting and laying out character content into an allocated area. This area is referred to as the available area and is determined by the document layout process defined in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +The purpose of the content layout process is to convert content associated with basic logical components into content associated with basic layout objects. This might imply a transformation of the content from one form to another. + +The content layout process results in the creation of basic layout object(s) into which the content is to be positioned. + +The dimensions of the basic layout object(s) are returned to the document layout process which determines the precise position of that basic layout object within the available area. + +### **14.1.2 Available area** + +The content layout process is constrained by the available area. That is, the maximum line length is constrained by the dimension of the available area in the direction of the character path. + +During the layout of the content of a basic logical object into a basic layout object, the following cases can occur: + +- the formatted or formatted processable content fits into the available area; +- the formatted or formatted processable content does not fit into the dimension of the available area in the direction of line progression. In this case, an additional or a new available area is required depending upon any constraints imposed by the document layout process; +- the formatted content does not fit into the dimension of the available area in the direction of the character path. In this case, a larger available area is required. + +NOTE – This case is most likely to occur when laying out formatted content associated with a basic logical component. + +### **14.1.3 Presentation attributes** + +The content layout process is carried out taking into account the presentation attributes applying to the basic logical object with which the content is associated. The content layout process must also take into account any control functions that are embedded in the content. + +The presentation attributes applying to the content layout process can be specified in the generic layout structure and presentation styles. The values of these presentation attributes are determined according to the defaulting rules specified in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +### **14.1.4 Character content architecture classes** + +The content layout process is described for basic logical objects associated with content that conforms to any of the three character content architecture classes (see 6.1) as follows: + +- Processable form character content in which the content layout process provides for formatting of the content. The content layout process results in the output of content in formatted or formatted processable form depending upon the desired form of document. + +- Formatted processable form character content in which the content layout process provides for reformatting of the content. This involves an initialization process which must be carried out on the content before the content layout process can be applied to that content. The content layout process results in the output of content in formatted or formatted processable form depending upon the desired form of document. +- Formatted form character content in which the content layout process has no effect on the content itself but still determines the dimensions of the basic layout object into which that content is to be positioned. + +### **14.1.5 Use of delimiters** + +When formatted processable form content is created as a result of the content layout process, all shared control functions and graphic characters inserted into the content as a result of the content layout process are enclosed between the delimiter control functions Start of String (SOS) and String Terminator (ST), and control functions and graphic characters deleted from the content as a result of the layout process are either enclosed between the delimiter control functions Start of Original String (SOOS) and ST or between SOOS and an inserted string delimited by the control functions SOS and ST. + +### **14.1.6 Layout of the content** + +For each of the three character content architecture classes, three cases of laying out the content of basic logical objects into basic layout objects are possible: + +- single basic logical object to single basic layout object: the content of a single basic logical object can be laid out into a single basic layout object and is the only content associated with this basic layout object; +- single basic logical object to multiple basic layout objects: the content of a single basic logical object is split among two or more basic layout objects, i.e. the content portions associated with two or more basic layout objects are derived from a single basic logical object; +- multiple basic logical objects to single basic layout object: the content of two or more basic logical objects is laid out into a single basic layout object, i.e. the content portions of two or more basic logical objects are associated with a single basic layout object. + +Multiple basic logical objects to multiple basic layout objects is also possible, but is not described explicitly since this is a combination of the last two cases above. + +### **14.1.7 Layout sequence** + +In all cases, the same sequence of steps for laying out content associated with a basic logical object is executed as follows: + +- initialization; +- determination of initial point; +- formatting of the content; +- identification of content portions; +- determination of basic layout object dimensions; +- determination of the value of the presentation attribute “initial offset”. + +This also results in the creation of a basic layout object. + +Although the sequence of steps is the same in all cases, the action performed at individual steps may vary. + +### **14.1.8 Character sets** + +The value of the attribute “content information” is always interpreted as a sequence of characters from the character set(s) designated and invoked by the attribute “graphic character sets” and by corresponding control functions in the content. Character content specified in the value of the attribute “content generator” is interpreted as follows: + +- Character content that is a string literal is interpreted in the same way as character content in the attribute “content information”. +- Character content that is generated by the application of string functions is interpreted as a sequence of characters from the character set(s) specified for those string functions. If these character sets are different from those used by any content preceding or following the content generated by application of the string functions, the character content layout process inserts appropriate designation and invocation control functions before and after the content generated by the application of the string functions. + +## **14.2 Content layout process for processable content** + +### **14.2.1 Single basic logical object to single basic layout object** + +#### **14.2.1.1 Initialization** + +In the case of processable form content, no initialization of the content is necessary. + +#### **14.2.1.2 Determination of initial point** + +The location of the initial point depends upon: + +- the presentation attributes “character path” and “line progression” (determining the start edge and top edge of the basic layout object); +- the presentation attribute “kerning offset” (specifying the location of the start edge of the positioning area relative to the start edge of the basic layout object); +- the presentation attribute “indentation” (specifying the distance between the initial point and the start edge of the positioning area); +- the invocation of a font by the presentation attribute “graphic rendition” and the presentation attribute “character orientation” (specifying the minimum backward extent of the first line box); +- the presence of control functions Partial Line Up (PLU), Parallel Texts (PTX), Line Position Backward (VPB) and font invocation by Select Graphic Rendition (SGR) in the first line of characters to be imaged (modifying the backward extent of the first line box). + +The position of the initial point relative to the start edge and top edge of the positioning area is determined such that: + +- its distance from the top edge of the positioning area is equal to the backward extent of the first line box; +- its distance from the start edge of the positioning area is equal to the value specified by the presentation attribute “indentation”. + +The position of the initial point relative to the upper left corner of the basic layout object can be determined only after the dimension of the basic layout object has been determined (see 14.2.1.5). This value is assigned to the presentation attribute “initial offset” and should always be specified explicitly in order to achieve the desired result by the content imaging process. + +#### **14.2.1.3 Formatting of the content** + +Formatting of the content involves: + +- the positioning of character images within a line box (see 7.2); +- the determination of line breaks; +- the positioning of line boxes within the basic layout object (see 7.3). + +It may involve the insertion of control functions and the assignment of presentation attribute values to the basic layout object. + +##### **14.2.1.3.1 Positioning of character images within a line box** + +There are two sets of operations that have an effect on the positioning of character images within a line box. One of these sets is related to the presentation attribute “formatting indicator”, the other is not. + +The operations related to the attribute “formatting indicator” are: + +- alignment (presentation attribute “alignment”); +- tabulation (presentation attribute “line layout table” and the control function STAB); +- first line offset (presentation attribute “first line offset”); +- itemization (presentation attribute “itemization”); +- pairwise kerning (presentation attribute “pairwise kerning”). + +Alignment and tabulation are mutually exclusive but itemization and first line offset may be applied in combination with either of them. + +These operations may be performed by either the content layout process or the content imaging process. However, they can be performed by the content layout process only if the presentation attribute “formatting indicator” and the control functions Character Position Backward (HPB), Character Position Relative (HPR), Set Additional Character Separation (SACS), Set Reduced Character Separation (SRCS) and Set SPACE Width (SSW) are available in the content architecture class concerned. + +The result of performing these operations by the content layout process is the insertion of the above control functions in the content. + +If the content layout process has performed all of the specified operations for a basic layout object and inserted all necessary control functions, the value of the presentation attribute “formatting indicator” is set to “yes”, otherwise it is set to “no”. + +Whether or not the content layout process inserts these control functions, it always determines the allocation of characters to each line box and the dimensions of each line box. + +NOTE – If the value of the presentation attribute “formatting indicator” is “no” or if the font substitution has been made, then the content imaging process should perform these operations. + +The other set of operations which are not related to the presentation attribute “formatting indicator” are: + +- character ordering (control function SRS); +- parallel annotation (control function PTX); +- graphic character composition (control function GCC). + +###### **14.2.1.3.1.1 Pairwise kerning** + +If the presentation attribute “pairwise kerning” specifies “yes” and the content layout process is capable of performing this function and the font used provides the necessary information, then certain combinations of character images are positioned closer to (or further apart from) each other than determined by their position and escapement points. + +When pairwise kerning is performed by the content layout process, it will result in the insertion of control functions Character Position Backward (HPB) or Character Position Relative (HPR) between the two characters involved. + +###### **14.2.1.3.1.2 First line offset** + +The characters associated with the first line can be controlled to be laid out differently from the rest of the lines in this object. + +The presentation attribute “first line offset” specifies if the first line has an overhang or indentation relative to the line home position. + +When first line offset is performed by the content layout process, it will result in the insertion of a control function Character Position Backward (HPB) or Character Position Relative (HPR). + +###### **14.2.1.3.1.3 Itemization** + +The first line of a basic layout object may contain an item identifier. The position of the item identifier is controlled by the presentation attribute “itemization”. + +When itemization is performed by the content layout process, it will result in the insertion of a control function Character Position Backward (HPB) or Character Position Relative (HPR) before the text of the item identifier. + +###### **14.2.1.3.1.4 Alignment** + +None of the alignments except “start-aligned” can be performed until the dimensions of the basic layout object have been determined (see 14.2.1.5). + +When alignment is performed by the content layout process, the line length for alignment is determined to be: + +- for the first line, the distance between the line home position and the end edge of the positioning area minus the value of the presentation attribute “first line offset”; +- for all other lines, the distance between the line home position and the end edge of the positioning area. + +The various values of the presentation attribute “alignment” are treated as follows: + +- “start-aligned” does not affect the output of the content layout process; + +- “end-aligned“ and “centred“ result in the insertion of a control function Character Position Relative (HPR) either before the first graphic character of each line or after the Carriage Return (CR) delimiting the item identifier if the presentation attribute “itemization” specifies a value other than “no itemization“; +- “justified“ results in the insertion of zero, one or more control functions Set SPACE Width (SSW), Set Additional Character Separation (SACS) and/or Set Reduced Character Separation (SRCS) in each line which ends with a line terminator inserted by the content layout process. The precise usage of SACS, SRCS and SSW is implementation dependent. + +NOTE – The presentation attribute alignment” does not apply to the item identifier. + +When the presentation attribute “alignment” has the value “justified“, irrespective of whether the alignment is performed by the content layout process or the content imaging process, the control function No Justify (JFY) is inserted at the beginning of the last line of a character sequence in order to avoid justification of this line by the content imaging process. + +###### **14.2.1.3.1.5 Tabulation** + +When tabulation is performed by the content layout process, it results in the insertion of each occurrence of a control function Character Position Relative (HPR) or Character Position Backward (HPB) between each occurrence of the control function Selective Tabulation (STAB) and the first graphic character following it. + +###### **14.2.1.3.1.6 Parallel annotation** + +The occurrence of the control function Parallel Texts (PTX) in the content specifies that a string of characters is to be laid out as a parallel annotation to another specified string of characters. The result of the content layout process is as described in 7.2.5. + +If the output of the content layout process is in formatted form, the positioning of the parallel annotation is achieved by the removal of all occurrences of PTX and the insertion of the appropriate control functions Character Position Relative (HPR), Character Position Backward (HPB), Line Position Relative (VPR) and Line Position Backward (VPB). + +If the output of the content layout process is in formatted processable form, the positioning of the parallel annotation is achieved by inserting the control functions Character Position Relative (HPR), Character Position Backward (HPB), Line Position Relative (VPR) and Line Position Backward (VPB) and enclosing them by the delimiter control functions Start of String (SOS) and String Terminator (ST). + +###### **14.2.1.3.1.7 Character ordering** + +The occurrence of the control function Start Reverse String (SRS) in the content of a basic logical object controls the direction of imaging of the interchanged characters. The result of the content layout process is as described in 7.2.4. + +###### **14.2.1.3.1.8 Graphic character composition** + +The control function Graphic Character Composition (GCC) is used to combine two or more graphic characters into a single symbol, the width of which may be less than the sum of the widths of the component characters. + +##### **14.2.1.3.2 Insertion of line breaks** + +The formatting process commences by creating a line box. Each hard line terminator in the content causes the creation of a subsequent line box. + +Additional line breaks, and hence additional line boxes, may be produced as a result of the formatting process. If the output of the formatting process is formatted processable form, the inserted line breaks are represented by CR/LF combinations delimited by the control function sequence SOS ... ST. This control function sequence may include other characters or control functions created as a result of the inserted line break (hyphens, for example). Optionally, characters deleted by such an algorithm are enclosed either in an SOOS-ST string or between an SOOS control function and the SOS-ST string. + +If the output is in formatted form, the inserted line breaks consist of hard line terminators represented by the control function sequence CR LF. All occurrences of the control functions Break Permitted Here (BPH) and No Break Here (NBH) are deleted. + +It is the intention of the formatting process that the number of characters between the inserted line breaks is the maximum possible for each line. The exact algorithm for inserting line breaks is implementation dependent and is not defined in UIT-T Rec. T.410-Series | ISO/IEC 8613. However, the line break algorithm shall conform to the following constraints: + +- a) a soft line break may be inserted + - after a SP which is not immediately followed by another SP or the control function NBH (No Break Here); + - after the control function BPH (Break Permitted Here); + - at a point determined by an implementation or language dependent algorithm. +- b) a line break is not permitted + - when a subscripted rendition is active; + - within a string with reversed presentation direction; + - within a string of parallel annotation. + +##### **14.2.1.3.3 Positioning of line boxes** + +The first line box is positioned with its line home position at the initial point as described in 14.2.1.2. + +Each line box is positioned with its line home position on the line from the initial point in the direction of line progression. + +When proportional line spacing is not to be performed, the distance between the line home positions of two successive line boxes is equal to the current line spacing. The initial value of the current line spacing is the value of the presentation attribute “line spacing”. This value may be altered by occurrences of the control function Select Line Spacing (SVS) and Set Line Spacing (SLS). + +When proportional line spacing is to be performed by the content layout process, the distance between the line home positions of two successive line boxes is evaluated by an implementation dependent algorithm. If the evaluated distance differs from the current value of line spacing, the control function Set Line Spacing (SLS) is inserted before the line terminator of the first line. The evaluated distance is inserted as the parameter of this control function and also becomes the current line spacing. + +If the output of the content layout process is in formatted processable form, those occurrences of the control function Set Line Spacing (SLS) inserted by the content layout process are enclosed by the delimiters Start of String (SOS) and String Terminator (ST). + +#### **14.2.1.4 Identification of content portions** + +The content layout process shall also provide a value for the attribute “content portion identifier-layout” for each content portion associated with the layout structure. + +#### **14.2.1.5 Determination of object dimensions** + +The dimensions of the basic layout object created by the content layout process can only be determined after the formatting action is completed. + +The dimension of the basic layout object in the direction of the line progression is such that this dimension is the minimum required to contain all line boxes that make up the formatted content allocated to it. + +NOTE 1 – There may be only one line box created by the formatting process. + +For the dimension of the basic layout object in the direction of the character path, two cases have to be distinguished. + +- The formatting process can allocate all content to one single line box, taking into account all applicable presentation attributes. In this case, the dimension of the basic layout object in the direction of the character path is equal to the minimum dimension of that line box which can contain the formatted content. + +NOTE 2 – This dimension will usually be less than the dimension of the available area in the direction of the character path and therefore a value of “left-hand aligned” or “centred” for the attribute “block alignment” will have a visual effect. + +- The formatting process cannot allocate all content to one single line box, taking into account all applicable presentation attributes. In this case, the dimension of the basic layout object in the direction of the character path is equal to the dimension of the available area in that direction. Full use of the value of this dimension should be made during the formatting process, i.e. the number of line boxes should be minimized, subject to the specifications of the presentation attributes and layout directives. + +NOTE 3 – The formatting process is considered implementation dependent, i.e. different implementations may produce a different number of line boxes for the same character content. + +The mapping to horizontal and vertical dimensions of the basic layout object is dependent upon the character path as shown in Table 5: + +**Table 5 – Character path and horizontal/vertical dimension of a basic layout object** + +| Character path | Dimension in direction of character path | Dimension in direction orthogonal to character path | +|-----------------------|--------------------------------------------|-----------------------------------------------------| +| d0, d180<br>d90, d270 | Horizontal dimension<br>Vertical dimension | Vertical dimension<br>Horizontal dimension | + +### 14.2.2 Single basic logical object to multiple basic layout objects + +If the formatted content does not fit into the available area in the direction of line progression then an additional available area has to be obtained from the document layout process, e.g. in the case of a page boundary. In this case, the content of a single basic logical object is allocated to more than one basic layout object. The original content portion is split into several content portions, each corresponding to a different basic layout object. + +There are two changes with respect to the description in 14.2.1: + +- the presentation attributes of the second and subsequent basic layout objects are given values corresponding to the status of rendition (line spacing, character spacing, graphic renditions etc.) at the end of the previous basic layout object; +- the allocation of content to basic layout objects is performed such that the presentation attributes “orphan size” and “widow size” are fulfilled. + +### 14.2.3 Multiple basic logical objects to single basic layout object + +When concatenation results in the content associated with a more than one basic logical object being laid out in a single basic layout object (see 9.5), it may be necessary for the content layout process to insert control functions at the beginning of the second and subsequent basic logical objects so that the values of certain presentation attributes associated with those basic logical objects are applied. These control functions are: + +- Select Character Spacing (SFS) or Set Character Spacing (SCS) for “character spacing”; +- Designation and/or invocation sequences for “graphic character sets”; +- Identify Graphic Subrepertoire (IGS) for “graphic character subrepertoire”; +- Select Graphic Rendition (SGR) for “graphic rendition”; +- Select Line Spacing (SVS) or Set Line Spacing (SLS) for “line spacing”. + +If the output of the content layout process is in formatted processable form, then the control functions inserted by the content layout process are enclosed by the delimiters Start of String (SOS), Start of Original String (SOOS) and String Terminator (ST). + +The presentation attribute “proportional line spacing” specified for the second or subsequent basic logical objects is interpreted by the content layout process as described in 14.2.1. + +The other presentation attributes specified for the second and subsequent basic logical objects are ignored (see 9.5). + +For logical and shared control functions other than those for which a corresponding presentation attribute exists that is not ignored when concatenation is in effect, the scope extends to the end of the concatenated sequence of basic logical objects. These control functions are: Partial Line Up (PLU) and Partial Line Down (PLD), Line Position Relative (VPR) and Line Position Backward (VPB), Start Reverse String (SRS), Parallel Texts (PTX), and Selective Tabulation (STAB). Accordingly, no insertion of such control functions at the start of a new basic logical object is necessary. + +## 14.3 Content layout process for formatted processable content + +For formatted processable form content, the initialization step of the content layout process shall + +- remove all SOOS control functions and all SOS-ST control strings from the content; +- remove all layout control functions (BS, HPB, HPR, JFY, SACS, SRCS and SSW) from the content (see 13.2); +- combine all content portions associated with the same basic logical object into a single content portion in order to prevent unnecessary fragmentation of the document content which could otherwise occur; +- delete the content portion attribute “Content identifier-layout”, if present. + +After initialization, the content is in processable form. The remaining steps of the content layout process are as described for processable content (see 14.2). + +## 14.4 Content layout process for formatted content + +For formatted content, the content layout process still has to determine the dimension of the basic layout object to be allocated. + +The same steps of the content layout process are used as for processable form content. In this case, however, formatting only involves + +- the positioning of character images within a line box as described in 7.2 and 14.2.1.3.1; +- the positioning of line boxes within a basic layout object as described in 7.3. + +The dimension of the basic layout object in the direction of the character path is set equal to the minimum required to allow for the positioning within line boxes of all characters associated with the basic layout object. + +# 15 Content imaging process + +This clause describes a content imaging process for basic logical objects associated with content architecture of type character. + +Its purpose is to aid understanding of the semantics of the presentation attributes and control functions by describing the required results of such a process. However, it is not intended to specify any process that might be carried out in a particular implementation to achieve these results. + +## 15.1 Introduction + +The content imaging process is only concerned with the layout structures, the presentation styles and the content of basic layout components conforming to this part of ITU-T Rec. T.410-Series | ISO/IEC 8613. + +All logical control functions, if any, are ignored. + +The content imaging process is only applicable to the formatted and formatted processable form character content architecture classes. + +## 15.2 Content imaging process for formatted content + +This subclause describes how the various shared and layout presentation attributes and shared and layout control functions influence the image of the contents. + +Most shared presentation attributes and shared control functions serve the purpose of positioning and orienting character images along reference lines and of positioning and orienting these reference lines within the basic layout object. + +Thus, the effects of most shared presentation attributes and shared control functions have already been described in the content layout process. + +Most layout presentation attributes and control functions are related to positioning and, thus, have already been described as the result of the content layout process. + +The following subclauses provide additional information relating to the content imaging process. + +### **15.2.1 Determination of initial point** + +The active position for imaging is set on the initial point within the basic layout object. This information is derived from the presentation attribute “initial offset”. + +### **15.2.2 Choosing character images** + +The following presentation attributes and control functions determine the character images to be chosen for imaging: + +- “graphic character sets” and code extension announcers”, designation and invocation control functions; +- “character fonts” (together with the attribute “fonts list” in the document profile); +- “graphic rendition” and Select Graphic Rendition (SGR). + +If the specified font is not available, the content imaging process may decide to substitute this font by making use of the font information available in the document profile attribute “fonts list”. + +### **15.2.3 Formatting indicator** + +The presentation attribute “formatting indicator” specifies whether first line offset, itemization, alignment, tabulation and pairwise kerning have already been performed by the content layout process or not. + +If not, or if the result from the content layout process has been invalidated by a font substitution, then the content imaging process shall perform the task in the same way as described in the content layout process (see 14.2.1.3.1). + +## **15.3 Content imaging process for formatted processable content** + +For content in formatted processable form, the only difference from the case of formatted form is that all logical control functions and the delimiter control functions Start of String (SOS) and String Terminator (ST) as well as any deleted text delimited by the delimiter control function Start of Original String (SOOS) and the next occurrence of one of the delimiter control functions SOS or ST are ignored. + +The effect of shared and layout presentation attributes and shared and layout control functions is as described in 15.2. + +# **16 Interactions between presentation attributes and control functions** + +This clause contains a summary of the interactions among and between presentation attributes and control functions defined in various places in this part of ITU-T Rec. T.410-Series | ISO/IEC 8613 as follows: + +- Line Feed (LF) is restricted to be used in the following cases: + - 1) at the beginning of the content of a basic layout component; + - 2) immediately following a control function Carriage Return (CR); + - 3) immediately following another LF. +- Break Permitted Here (BPH) or CR is not permitted in the following cases: + - 1) when Partial Line Up (PLU) or Partial Line Down (PLD) is active; + - 2) after Line Position Relative (VPR) and/or Line Position Backward (VPB) have moved the active position away from the reference line; + - 3) between the control functions SRS 1 and SRS 0; + - 4) between the control functions PTX 1 and PTX 0. + +- Rendition aspects defined by some presentation attributes can be overridden by control functions embedded in content portions as shown in Table 6. +- When the presentation attribute “line layout table” specifies any tabulation stops, the presentation attribute “alignment” is assumed to have the value “start-aligned”. + +**Table 6 – Presentation attributes that can be overridden by control functions** + +| Presentation attribute | Control function | +|---------------------------------|----------------------------------| +| Character spacing | SHS, SCS | +| Line spacing | SVS, SLS | +| Graphic rendition | SGR | +| Graphic character subrepertoire | IGS | +| Graphic character sets | Code extension control functions | + +# 17 Definition of character content architecture classes + +This clause defines the three classes of character content architecture as described in 6.1, namely: + +- A formatted form character content architecture which allows for document content to be presented (e.g. printed or displayed) as intended by the originator. Formatted form can be used in any basic component. +- A processable form character content architecture which allows for document content to be processed (e.g. edited or formatted). Processable form can be used in any basic logical component. +- A formatted processable form character content architecture which allows for document content to be processed and also to be presented as intended by the originator. Formatted processable form can be used in any basic component. + +Subclauses 17.1, 17.2 and 17.3 specify the categories of presentation attributes and control functions that pertain to these content architecture classes. The individual presentation attributes and control functions are summarized in Tables 5 and 6. + +The permissible values and the default values of the presentation attributes and the control functions parameter values are defined in clauses 9 and 13 respectively. + +In order to aid the definition of a subset of a content architecture class for use in document application profiles (see ITU-T Rec. T.411 | ISO/IEC 8613-1), the presentation attributes and the control functions that are applicable to each content architecture class are listed in Annex B, together with their permissible values and default values. + +## 17.1 Formatted character content architecture class + +The following categories of presentation attributes and control functions pertain to the formatted character content architecture class: + +- shared presentation attributes (see 9.1); +- layout presentation attributes (see 9.2); +- shared control functions (see 13.1); +- layout control functions (see 13.2). + +## 17.2 Processable character content architecture class + +The following categories of presentation attributes and control functions pertain to the processable character content architecture class: + +- shared presentation attributes (see 9.1); +- logical presentation attributes (see 9.3); +- shared control functions (see 13.1); +- logical control functions (see 13.3). + +## 17.3 Formatted processable character content architecture class + +The following categories of presentation attributes and control functions pertain to the formatted processable character content architecture class: + +- shared presentation attributes (see 9.1); +- layout presentation attributes (see 9.2); +- logical presentation attributes (see 9.3); +- shared control functions (see 13.1); +- layout control functions (see 13.2). +- logical control functions (see 13.3); +- delimiters (see 13.4). + +**Table 7 – Summary of presentation attributes** + +| Presentation attribute | Character content architecture class | | | +|---------------------------------|--------------------------------------|-------------|-----------------------| +| | Formatted | Processable | Formatted processable | +| alignment | X | X | X | +| character fonts | X | X | X | +| character orientation | X | X | X | +| character path | X | X | X | +| character spacing | X | X | X | +| code extension announcers | X | X | X | +| first line offset | X | | X | +| formatting indicator | X | X | X | +| graphic character sets | X | X | X | +| graphic character subrepertoire | X | X | X | +| graphic rendition | X | X | X | +| indentation | | X | X | +| initial offset | X | | X | +| itemization | X | X | X | +| kerning offset | X | X | X | +| line layout table | X | X | X | +| line progression | X | X | X | +| line spacing | X | X | X | +| orphan size | | X | X | +| pairwise kerning | X | X | X | +| proportional line spacing | | X | X | +| widow size | | X | X | + +Table 8 – Summary of control functions + +| Control function | | Character content architecture | | | +|----------------------------------|----------------------------------|--------------------------------|-------------|-----------------------| +| | | Formatted | Processable | Formatted processable | +| BPH | Break Permitted Here | | X | X | +| BS | Backspace | X | | X | +| CR | Carriage Return | X | X | X | +| GCC | Graphic Character Composition | X | X | X | +| HPB | Character Position Relative | X | | X | +| HPR | Character Position Backward | X | | X | +| IGS | Identify Graphic Subrepertoire | X | X | X | +| JFY | No Justify | X | | X | +| LF | Line Feed | X | X | X | +| NBH | No Break Here | | X | X | +| PLD | Partial Line Down | X | X | X | +| PLU | Partial Line Up | X | X | X | +| PTX | Parallel Texts | | X | X | +| SACS | Set Additional Character Spacing | X | | X | +| SCS | Set Character Spacing | X | X | X | +| SGR | Select Graphic Rendition | X | X | X | +| SHS | Select Character Spacing | X | X | X | +| SLS | Set Line Spacing | X | X | X | +| SOOS | Start of Original String | | | X | +| SOS | Start of String | | | X | +| SP | SPACE | X | X | X | +| SRCS | Set Reduced Character Spacing | X | | X | +| SRS | Start Reverse String | X | X | X | +| SSW | Set SPACE Width | X | | X | +| ST | String Terminator | | | X | +| STAB | Selective Tabulation | X | X | X | +| SUB | Substitute | X | X | X | +| SVS | Selective Line Spacing | X | X | X | +| VPB | Line Position Backward | X | X | X | +| VPR | Line Position Relative | X | X | X | +| Code extension control functions | | X | X | X | + +# Annex A SGML representation of character content-specific attributes for ODL + +(This annex forms an integral part of this International Standard) + +## A.1 Introduction + +This annex specifies a standardized SGML representation of attributes related to the character content architecture, for use with the Office Document Language (ODL) defined in ITU-T Rec. T.415 | ISO/IEC 8613-5. ODL is an SGML application conforming to ISO 8879. + +The definitions of ISO 8879 apply to this annex. + +## A.2 Names and public identifiers + +The following notation declarations include the public identifiers of the data content notations for content architecture classes defined in this Specification. The ODL content architecture class names follow the prefix ODA” in the notation names. + +``` +<!NOTATION ODAcf PUBLIC ISO/IEC 8613-6:1993//NOTATION + Character formatted content architecture//EN"> + +<!NOTATION ODAcfp PUBLIC ISO/IEC 8613-6:1993//NOTATION + Character formatted processable content architecture//EN"> + +<!NOTATION ODAcp PUBLIC ISO/IEC 8613-6:1993//NOTATION + Character processable content architecture//EN"> +``` + +## A.3 Representation of attribute values + +Attribute values are represented in a clear text encoding, using the rules defined in this annex. + +NOTE 1 – The content portions themselves are encoded according to the body of this part of ITU-T Rec. T.410-Series | ISO/IEC 8613. + +The representations of the ODA attributes are presented in the form of SGML public text. In this form they can be referenced from a document, rather than be included within it. + +The semantics of the attribute values are specified in the body of this part of ITU-T Rec. T.410-Series | ISO/IEC 8613. + +The representation of attribute values is as specified in the body of this part of ITU-T Rec. T.410-Series | ISO/IEC 8613, except where a different representation is specified in the public text or elsewhere in this annex. + +The default values specified in the public text are those defined in the body of this part of ITU-T Rec. T.410-Series | ISO/IEC 8613. If a different default value is wanted for an element (such as a non-standard default value specified in the document profile or in an object class description), the public text should not be referenced; instead, the definitions should be duplicated with the required changes made in the default values. + +Attribute values are sequences of one or more parameters, separated by SGML separator characters. An omitted parameter is represented by the keyword: 00 + +A parameter is one of a number of primitive types: string, keyword, or integer. String parameters are delimited, and may contain separator characters. Other parameters are not delimited, and may not contain separator characters. + +NOTE 2 – Most attribute values consist of a single parameter. + +### A.3.1 Constructed parameters + +In this part of ITU-T Rec. T.410-Series | ISO/IEC 8613, a parameter is a constructed parameter if one or more of its permissible values is a group of two or more sub-parameters. The description of the attribute in the body of this part of ITU-T Rec. T.410-Series | ISO/IEC 8613 determines the number of sub-parameters, and whether any can be omitted. If more than one sub-parameter is present, they are separated from one another by commas. Successive commas denote an omitted sub-parameter, but they are required only if a succeeding sub-parameter is present. + +NOTE - For an example of a constructed parameter, see the attribute line layout table” in the public text. + +### A.3.2 Parentheses + +A constructed parameter is normally enclosed in parentheses but they can be omitted if no ambiguity would be created by doing so. If a sub-parameter is itself constructed, it shall be enclosed in parentheses. + +An empty constructed parameter is represented by: ( ) + +### A.3.3 Alternative representation + +The value of a constructed parameter can optionally be represented as the name of a data entity that contains the actual constructed parameter. + +NOTE - This technique can be used for long, constructed parameters that would otherwise cause the quantity limits of the concrete syntax to be exceeded. + +### A.3.4 String parameters + +A string parameter could contain characters not permitted in an SGML name token, and is therefore delimited by SGML LIT or LITA delimiters. + +A string parameter that is an escape sequence formulated in accordance with ISO 2022 is represented in the form used for the public text designating sequence" defined in ISO 8879. + +NOTE – This is the clear text form commonly used in ISO standards. + +### A.3.5 Keyword parameters + +Possible keyword values are defined by the body of this part of ITU-T Rec. T.410-Series | ISO/IEC 8613 for some parameters, and by this annex for others. + +Lowercase letters in keyword parameters are treated as though they were uppercase. + +For certain parameters whose permissible values constitute a set of keywords, fixed numeric values, or both keywords and fixed numeric values, the value is represented by choosing from a set of substitute keywords. These parameters are documented in comments in the public text, in the form: + +parameter name: keyword keyword ... + +with the keywords appearing in the same order as the permissible values that they represent appear within the body of this part of ISO 8613. For attributes that have only one parameter, the attribute name is the parameter name. + +NOTE - For example: -- alignment: S E C J - means that in the alignment attribute, a value of "s" represents "start-aligned", a value of "e" represents "end-aligned", and so on. + +### A.3.6 Integer parameters + +An integer is represented by a sequence of digits. If preceded by a hyphen, it represents a negative integer; otherwise, a positive integer. + +Parameters whose permissible values constitute an enumerated set of quantities of degrees or SMUs are represented by the integer quantities alone, without the word "degrees" or "SMU". + +## A.4 Presentation attributes + +### A.4.1 Shared presentation attributes (format attribute-directives) + +``` +<! -- (C) International Organization for Standardization 1993 +Permission to copy in any form is granted for use with conforming SGML systems and applications as +defined in ISO 8879, provided this notice is included in all copies. +``` + +``` +--> +``` + +``` +<! -- Public text entity. Typical invocation: +``` + +``` +<! ENTITY % c-p-ad PUBLIC "ISO/IEC 8613-6:1993//TEXT +Character Presentation format Attribute-Directives//EN"> +``` + +``` +<! ATTLIST (cf|cfp) %c-p-a; %c-p-ad;> +``` + +``` +--> +``` + +| | | | | +|----------|--------|----------|-------------------------------------------| +| calign | NAME | s | -- alignment: S E C J -- | +| cfonts | CDATA | #IMPLIED | -- character fonts -- | +| corient | NUMBER | 0 | -- character orientation: 0 90 180 270 -- | +| cpath | NUMBER | 0 | -- character path: 0 90 180 270 -- | +| ccharspc | NUMBER | #IMPLIED | -- character spacing -- | + +| | | | | +|----------|-------------------------------------------------------------|----------|---------------------------------------| +| cannounc | CDATA | #IMPLIED | -- code extension announcer -- | +| cfloff | NMTOKEN | 0 | -- first line offset -- | +| cgrcsets | CDATA | #IMPLIED | -- graphic character sets -- | +| cgrcsub | NUMBER | 0 | -- graphic character subrepertoire -- | +| cgrrend | NUMBERS | 0 | -- graphic rendition -- | +| citem | NMTOKENS | #IMPLIED | -- itemization -- | +| | -- identifier alignment: N S E -- | | | +| | -- identifier start offset: integer -- | | | +| | -- identifier end offset: integer -- | | | +| ckernoff | NUMBERS | "0 0" | -- kerning offset | +| lat | CDATA | " " | -- line layout table | +| | -- tabulation reference: integer -- | | | +| | -- tabulation position: integer -- | | | +| | -- alignment: S E C A -- | | | +| | -- alignment character string: string -- | | | +| | -- Example: lat = "(1,600,s) (2,2400,a, ".") (3,4800,e)" -- | | | +| clinepro | NUMBER | 270 | -- line progression: 90 270 -- | +| clinespc | NUMBER | #IMPLIED | -- line spacing -- | +| cpwkern | NAME | nk | -- pairwise kerning: K NK -- | + +### A.4.2 Layout presentation attributes (format attributes) + +<! -- (C) International Organization for Standardization 1993 + +Permission to copy in any form is granted for use with conforming SGML systems and applications as defined in ISO 8879, provided this notice is included in all copies. + +--> + +<! -- Public text entity. Typical invocation: + +<!ENTITY % c-p-a PUBLIC ISO/IEC 8613-6: 1993//TEXT +Character Presentation Format Attributes//EN"> + +<!ATTLIST (cf|cfp) %c-p-a; %c-p-ad; > + +--> + +| | | | | +|---------|---------|----------|----------------------------------| +| cformat | NAME | nf | -- formatting indicator: F NF -- | +| cintoff | NUMBERS | #IMPLIED | -- initial offset-- | + +### A.4.3 Logical presentation attributes (format directives) + +<! -- (C) International Organization for Standardization 1993 + +Permission to copy in any form is granted for use with conforming SGML systems and applications as defined in ISO 8879, provided this notice is included in all copies. + +--> + +<! -- Public text entity. Typical invocation: + +<!ENTITY % c-p-d PUBLIC ISO/IEC 8613-6: 1993//TEXT +Character Presentation Format Directives//EN"> + +<!ATTLIST (cfp|cp) %c-p-d; > + +--> + +| | | | | +|---------|--------|----|---------------------------------------| +| cindent | NUMBER | 0 | -- indentation -- | +| corphan | NUMBER | 1 | -- orphan size -- | +| cpropls | NAME | np | -- proportional line spacing: P NP -- | +| cwidow | NUMBER | 1 | -- widow size -- | + +## A.5 Coding attributes + +No character content coding attributes are defined for ODL. + +# **Annex B****Summary of content architecture classes** + +(This annex does not form an integral part of this Recommendation | International Standard.) + +This annex summarizes the presentation attributes and control functions that apply to each of the three content architecture classes (formatted, processable and formatted processable) defined in clause 17, together with their permissible values and default values or assumed values in the case that a control function/ parameter is not specified. + +The purpose of this annex is to facilitate the definition of a subset of a content architecture class for use in document application profiles (see ITU-T Rec. T.411 | ISO/IEC 8613-1). + +## **B.1 Formatted character content architecture class** + +**Table B.1 – Summary of permissible and default values for presentation attributes +applicable to the formatted character content architecture class** + +| Attribute | Permissible value(s) | Default value | +|------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------| +| alignment | Start-aligned,<br>end-aligned,<br>centred,<br>justified | Start-aligned | +| character fonts | | | +| font size | Any positive integer | None | +| font identifier | Any positive integer | None | +| character orientation | d0, d90,<br>d180, d270 | d0 | +| character path | 0, d90,<br>d180, d270 | d0 | +| character spacing | Any positive integer | Equivalent of 120 BMUs | +| code extension<br>announcers | Any string of escape sequences in accordance with ISO 2022 | Escape sequences for the G0 and G2 sets | +| first line offset | Any integer | 0 | +| formatting indicator | No, yes | No | +| graphic character sets | The escape sequences to designate, and any required locking shift functions to invoke, one or more registered graphic character sets | The escape sequences to designate, and the locking shift functions to invoke, the graphic character sets of ISO 6937-2 | +| graphic character<br>subrepertoire | 0 or the identifier of any registered subrepertoire of ISO 6937 | 0 | +| graphic rendition | 0, 1-7, 9, 10-19, 21-27, 29, 30-38, 40-48, 50 | 0 | +| initial offset | | | +| horizontal<br>coordinate | Any non-negative integer | See Table 2 | +| vertical coordinate | Any non-negative integer | See Table 2 | +| itemization | | | +| identifier alignment | No itemization,<br>start-aligned,<br>end-aligned | No itemisation | +| identifier start<br>offset | Any integer | The distance from the start edge of the positioning area to the line home position | +| identifier end offset | Any integer | 0 | +| kerning offset | | | +| start edge offset | Any non-negative integer | 0 | +| end edge offset | Any non-negative integer | 0 | +| line layout table | | | +| tab reference | One to four decimal digits | ) | +| tab position | Any non-negative integer | ) | +| alignment | Start-aligned,<br>end-aligned,<br>centred,<br>aligned-around | ) No<br>) Tabulationstops<br>) Defined<br>) | +| alignment string | Any characters | ) | +| line progression | d90, d270 | d270 | +| line spacing | Any positive integer | Equivalent of 200 BMUs | +| pairwise kerning | Yes, no | No | + +**Table B.2 – Summary of permissible and assumed values for control functions applicable to the formatted character content architecture class** + +| Attribute | Permissible value(s) | Default value | +|-----------|-----------------------------------------------------------------|------------------------| +| BS | Not applicable | Not applicable | +| CR | Not applicable | Not applicable | +| GCC | 0, 1, 2 | 0 | +| HPB | Any positive integer | Equivalent of 120 BMUs | +| HPR | Any positive integer | Equivalent of 120 BMUs | +| IGS | 0 or the identifier of any registered subrepertoire of ISO 6937 | 0 | +| JFY | 0 | 0 | +| LF | Not applicable | Not applicable | +| PLD | Not applicable | Not applicable | +| PLU | Not applicable | Not applicable | +| SACS | Any positive integer | 0 | +| SCS | Any positive integer | Equivalent of 120 BMUs | +| SGR | 0, 1-7, 9, 10-19, 21-27, 29, 30-38, 40-48, 50 | 0 | +| SHS | 0, 1, 2, 3 | 0 | +| SLS | Any positive integer | Equivalent of 200 BMUs | +| SP | Not applicable | Not applicable | +| SRCS | Any positive integer | 0 | +| SRS | 0, 1 | 0 | +| SSW | Any positive integer | None | +| STAB | Any | None | +| SUB | Not applicable | Not applicable | +| SVS | 0, 1, 2, 3, 4, 9 | 0 | +| VPB | Any positive integer | Equivalent of 100 BMUs | +| VPR | Any positive integer | Equivalent of 100 BMUs | + +In addition, any code extension control functions defined in ISO 2022, within the scope of the value of the attribute “code extension announcers”, is permitted. + +## B.2 Processable character content architecture class + +Table B.3 – Summary of permissible and default values for presentation attributes applicable to the processable character content architecture class + +| Attribute | Permissible value(s) | Default value | +|------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------| +| alignment | Start-aligned,<br>end-aligned,<br>centred,<br>justified | Start-aligned, | +| character fonts | Any positive integer | None | +| font size | Any positive integer | None | +| font identifier | d0, d90,<br>d180, d270 | d0 | +| character orientation | d0, d90,<br>d180, d270 | d0 | +| character path | Any positive integer | Equivalent of 120 BMUs | +| character spacing | Any string of escape | Escape sequences for the G0 and<br>G2 sets | +| code extension<br>announcers | Sequences in accordance with ISO 2022 | | +| first line offset | Any integer | 0 | +| formatting indicator | No, yes | No | +| graphic character sets | The escape sequences to designate, and any required locking<br>shift functions to invoke, one or more registered graphic<br>character sets | The escape sequences to designate,<br>and the locking shift functions to<br>invoke, the graphic character sets of<br>ISO 6937-2 | +| graphic character<br>subrepertoire | 0 or the identifier of any registered subrepertoire of ISO 6937 | 0 | +| graphic rendition | 0, 1-7, 9, 10-19, 21-27, 29, 30-38, 40-48, 50 | 0 | +| indentation | Any non-negative integer | 0 | +| itemization | | | +| identifier alignment | No itemization,<br>start-aligned,<br>end-aligned | No itemization | +| identifier start<br>offset | Any integer | The distance from the start edge of the<br>positioning area to the line home<br>position | +| identifier end offset | Any integer | 0 | +| kerning offset | | | +| start edge offset | Any non-negative integer | 0 | +| end edge offset | Any non-negative integer | 0 | +| line layout table | | | +| tab reference | One to four decimal digits | None | +| tab position | Any non-negative integer | None | +| alignment | Start-aligned,<br>end-aligned,<br>centred,<br>aligned-around | Start-aligned | +| alignment string | Any characters | None | +| line progression | d90, d270 | d270 | +| line spacing | Any positive integer | Equivalent of 200 BMUs | +| orphan size | Any positive integer | 1 | +| pairwise kerning | Yes, no | No | +| proportional line<br>spacing | Yes, no | No | +| widow size | Any positive integer | 1 | + +**Table B.4 – Summary of permissible and assumed values for control functions applicable to the processable character content architecture class** + +| Attribute | Permissible value(s) | Default value | +|-----------|-----------------------------------------------------------------|------------------------| +| BPH | Not applicable | Not applicable | +| CR | Not applicable | Not applicable | +| GCC | 0, 1, 2 | 0 | +| IGS | 0 or the identifier of any registered subrepertoire of ISO 6937 | 0 | +| LF | Not applicable | Not applicable | +| NBH | Not applicable | Not applicable | +| PLD | Not applicable | Not applicable | +| PLU | Not applicable | Not applicable | +| PTX | Not applicable | Not applicable | +| SCS | Any positive integer | Equivalent of 120 BMUs | +| SGR | 0, 1-7, 9, 10-19, 21-27, 29, 30-38, 40-48, 50 | 0 | +| SHS | 0, 1, 2, 3 | 0 | +| SLS | Any positive integer | Equivalent of 200 BMUs | +| SP | Not applicable | Not applicable | +| SRS | 0, 1 | 0 | +| STAB | Any | None | +| SUB | Not applicable | Not applicable | +| SVS | 0, 1, 2, 3, 4, 9 | 0 | +| VPB | Any positive integer | Equivalent of 100 BMUs | +| VPR | Any positive integer | Equivalent of 100 BMUs | + +In addition, any code extension control functions defined in ISO 2022, within the scope of the value of the attribute “code extension announcers”, is permitted. + +## **B.3 Formatted processable character content architecture class** + +**Table B.5 – Summary of permissible and default values for presentation attributes +applicable to the formatted processable character content architecture classs** + +| Attribute | Permissible value(s) | Default value | +|------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------| +| alignment | Start-aligned,<br>end-aligned,<br>centred,<br>justified | Start-aligned | +| character fonts | | | +| font size | Any positive integer | None | +| font identifier | Any positive integer | None | +| character orientation | d0, d90,<br>d180, d270 | d0 | +| character path | d0, d90,<br>d180, d270 | d0 | +| character spacing | Any positive integer | Equivalent of 120 BMUs | +| code extension<br>announcers | Any string of escape<br>sequences in accordance with ISO 2022 | Escape sequences for the G0 and G2 sets | +| first line offset | Any integer | 0 | +| formatting indicator | No, yes | No | +| graphic character sets | The escape sequences to designate, and any required locking shift functions to invoke, one or more registered graphic character sets | The escape sequences to designate, and the locking shift functions to invoke, the graphic character sets of ISO 6937-2 | +| graphic character<br>subrepertoire | 0 or the identifier of any registered subrepertoire of ISO 6937 | 0 | +| graphic rendition | 0, 1-7, 9, 10-19, 21-27, 29, 30-38, 40-48, 50 | 0 | +| initial offset | | | +| horizontal<br>coordinate | Any non-negative integer | See Table 2 | +| vertical coordinate | Any non-negative integer | See Table 2 | +| indentation | Any positive integer | 0 | +| itemisation | | | +| identifier alignment | No itemisation,<br>start-aligned,<br>end-aligned | No itemisation | +| identifier start<br>offset | Any integer | The distance from the start edge of the positioning area to the line home position | +| identifier end offset | Any integer | 0 | +| kerning offset | | | +| start edge offset | Any non-negative integer | 0 | +| end edge offset | Any non-negative integer | 0 | +| line layout table | | | +| tab reference | One to four decimal digits | None | +| tab position | Any non-negative integer | None | +| alignment | start-aligned;<br>end-aligned,<br>centred,<br>aligned-around | start aligned | +| alignment string | Any characters | None | +| line progression | d90, d270 | d270 | +| line spacing | Any positive integer | Equivalent of 200 BMUs | +| orphan size | Any positive integer | 1 | +| pairwise kerning | Yes, no | No | +| proportional line<br>spacing | Yes, no | No | +| widow size | Any positive integer | 1 | + +**Table B.6 – Summary of permissible and assumed values for control functions applicable to the formatted processable character content architecture class** + +| Control function | Permissible value(s) | Assumed value | +|------------------|-----------------------------------------------------------------|------------------------| +| BPH | Not applicable | Not applicable | +| BS | Not applicable | Not applicable | +| CR | Not applicable | Not applicable | +| GCC | 0, 1, 2 | 0 | +| HPB | Any positive integer | Equivalent of 120 BMUs | +| HPR | Any positive integer | Equivalent of 120 BMUs | +| IGS | 0 or the identifier of any registered subrepertoire of ISO 6937 | 0 | +| JFY | 0 | 0 | +| LF | Not applicable | Not applicable | +| NBH | Not applicable | Not applicable | +| PLD | Not applicable | Not applicable | +| PLU | Not applicable | Not applicable | +| PTX | 0, 1, 3 | 0 | +| SACS | Any positive integer | 0 | +| SCS | Any positive integer | Equivalent of 120 BMUs | +| SGR | 0, 1-7, 9, 10-19, 21-27, 29, 30-38, 40-48, 50 | 0 | +| SHS | 0, 1, 2, 3 | 0 | +| SLS | Any positive integer | Equivalent of 200 BMUs | +| SOOS | Not applicable | Not applicable | +| SOS | Not applicable | Not applicable | +| SP | Not applicable | Not applicable | +| SRCS | Any positive integer | 0 | +| SRS | 0, 1 | 0 | +| SSW | Any positive integer | None | +| ST | Not applicable | Not applicable | +| STAB | Any | None | +| SUB | Not applicable | Not applicable | +| SVS | 0, 1, 2, 3, 4, 9 | 0 | +| VPB | Any positive integer | Equivalent of 100 BMUs | +| VPR | Any positive integer | Equivalent of 100 BMUs | + +In addition, any code extension control functions defined in ISO 2022, within the scope of the value of the attribute “code extension announcers”, is permitted. + +# Annex C Coded representations of control functions + +(This annex does not form an integral part of this Recommendation | International Standard.) + +Coded representations of control functions are defined in ISO 6429. A summary of the coded representations of the control functions defined in this Specification is given in Table C.1. + +**Table C.1 – Coded representations of control functions** + +| Control function | | Coded representation | +|------------------|----------------------------------|-----------------------| +| BPH | Break Permitted Here | 08/02 | +| BS | Backspace | 00/08 | +| CR | Carriage Return | 00/13 | +| HPB | Character Position Backward | CSI Pn 06/10 | +| HPR | Character Position Relative | CSI Pn 06/01 | +| GCC | Graphic Character Composition | CSI Ps 02/00 05/15 | +| IGS | Identify Graphic Subrepertoire | CSI Ps 02/00 04/13 | +| JFY | No Justify | CSI 02/00 04/06 | +| LF | Line Feed | 00/10 | +| NBH | No Break Here | 08/03 | +| PLD | Partial Line Down | 08/11 | +| PLU | Partial Line Up | 08/12 | +| PTX | Parallel Texts | CSI Ps 05/12 | +| SCS | Set Character Spacing | CSI Pn 02/00 06/07 | +| SGR | Select Graphic Rendition | CSI Ps... 06/13 | +| SHS | Select Character Spacing | CSI Ps 02/00 04/11 | +| SACS | Set Additional Character Spacing | CSI Pn 02/00 05/12 | +| SLS | Set Line Spacing | CSI Pn 02/00 06/08 | +| SRCS | Set Reduced Character Spacing | CSI Pn 02/00 06/06 | +| SOOS | Start Of Original String | <currently undefined> | +| SOS | Start Of String | 09/08 | +| SSW | Set SPACE Width | CSI Pn 02/00 05/11 | +| SP | Space | 02/00 | +| SRS | Start Reverse String | CSI Ps 05/11 | +| ST | String Terminator | 09/12 | +| STAB | Selective Tabulation | CSI Ps 02/00 05/14 | +| SUB | Substitute | 01/10 | +| SVS | Select Line Spacing | CSI Ps 02/00 04/12 | +| VPB | Line Position Backwards | CSI Pn 06/11 | +| VPR | Line Position Relative | CSI Pn 06/05 | + +In Table C.1, CSI denotes the Control Sequence Introducer represented by the bit-combination 09/11 and Pn and Ps denote respectively numeric and selective parameter values represented by one or more bit combinations in the range 03/00 to 03/09. + +The coded representation of a control function with parameters but with Pn or Ps omitted represents that control function with the default value of the parameter. + +# Annex D Summary of object identifiers + +(This annex does not form an integral part of this Recommendation | International Standard.) + +Values of ASN.1 object identifiers are assigned in various clauses of this part of ITU-T Rec. T.410-Series | ISO/IEC 8613. These assignments are summarized in Table D.1. + +**Table D.1 – Summary of ASN.1 object identifiers** + +| Object identifier value | Description | Clause | +|-------------------------|--------------------------------------------------------------------------|--------| +| { 2 8 1 6 2 } | Identifies module<br>Character-Presentation-Attributes | 11.2 | +| { 2 8 1 6 3 } | Identifies module<br>Character-Coding-Attributes | 11.3 | +| { 2 8 1 6 4 } | Identifies module<br>Character-Profile-Attributes | 11.4 | +| { 2 8 2 6 0 } | Identifies Formatted character content<br>architecture class | 9.4 | +| { 2 8 2 6 1 } | Identifies Processable character content<br>architecture class | 9.4 | +| { 2 8 2 6 2 } | Identifies Formatted-processable character<br>content architecture class | 9.4 | +| { 2 8 3 6 0 } | Identifies ISO 2022 type of coding | 10.1 | \ No newline at end of file diff --git a/marked/T/T-REC-T.417-199303-I_PDF-E/raw.md b/marked/T/T-REC-T.417-199303-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..92c2452ae2cfc019d0c5d50099b48ea4f6737326 --- /dev/null +++ b/marked/T/T-REC-T.417-199303-I_PDF-E/raw.md @@ -0,0 +1,2274 @@ + + +![ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol crossing it diagonally from bottom-left to top-right.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol crossing it diagonally from bottom-left to top-right. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## T.417 + +(03/93) + +**TELEMATIC SERVICES** + +**TERMINAL EQUIPMENTS AND PROTOCOLS +FOR TELEMATIC SERVICES** + +**INFORMATION TECHNOLOGY – OPEN +DOCUMENT ARCHITECTURE (ODA) +AND INTERCHANGE FORMAT: RASTER +GRAPHICS CONTENT ARCHITECTURES** + +**ITU-T Recommendation T.417** + +# Foreword + +ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. Some 179 member countries, 84 telecom operating entities, 145 scientific and industrial organizations and 38 international organizations participate in ITU-T which is the body which sets world telecommunications standards (Recommendations). + +The approval of Recommendations by the Members of ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, 1993). In addition, the World Telecommunication Standardization Conference (WTSC), which meets every four years, approves Recommendations submitted to it and establishes the study programme for the following period. + +In some areas of information technology, which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. The text of ITU-T Recommendation T.417 was approved by the WTSC (Helsinki, March 1-12, 1993). The identical text is also published as ISO/IEC International Standard 8613-7. + +# --- NOTES + +1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector. + +In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms "CCITT, CCIR or IFRB" or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. + +2 In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# CONTENTS + +| | <i>Page</i> | +|--------------------------------------------------------------------------------------|-------------| +| SUMMARY | vi | +| INTRODUCTION | vi | +| 1 Scope | 1 | +| 2 Normative references | 2 | +| 2.1 Identical Recommendations International Standards | 2 | +| 2.2 Paired Recommendations International Standards equivalent in technical content | 2 | +| 2.3 Additional references | 2 | +| 3 Definitions | 2 | +| 4 Abbreviations | 2 | +| 5 Conventions | 3 | +| 6 General principles | 3 | +| 6.1 Content architecture classes | 3 | +| 6.1.1 Formatted content architecture class | 3 | +| 6.1.2 Formatted processable content architecture class | 3 | +| 6.2 Content | 4 | +| 6.2.1 Binary mode | 4 | +| 6.2.2 Colour mode | 4 | +| 6.3 Presentation attributes | 4 | +| 6.4 Content portion attributes | 4 | +| 6.5 Coding of content information | 4 | +| 6.6 Picture element (pel) array | 4 | +| 6.7 Colour spaces applicable to the raster graphics content architecture | 5 | +| 7 Principles of positioning pels | 5 | +| 7.1 Basic concepts | 6 | +| 7.1.1 Measurement units and directions | 6 | +| 7.1.2 Coordinate systems | 6 | +| 7.2 Pel image model | 6 | +| 7.3 Positioning of pels | 6 | +| 7.3.1 The clipped pel array | 7 | +| 7.3.2 Discarded pels | 7 | +| 7.4 Tiling | 7 | +| 7.5 Positioning of pels in a basic layout object | 9 | +| 7.5.1 Positioning parameters | 9 | +| 7.5.2 Positioning rules for formatted content | 10 | +| 7.5.3 Positioning rules for formatted processable content | 10 | +| 8 Definition of raster graphics presentation attributes | 10 | +| 8.1 Shared presentation attributes | 11 | +| 8.1.1 Clipping | 11 | +| 8.1.2 Line progression | 12 | +| 8.1.3 Pel path | 12 | +| 8.2 Layout presentation attributes | 12 | +| 8.2.1 Initial offset | 12 | +| 8.2.2 Pel transmission density | 13 | +| 8.3 Logical presentation attributes | 14 | +| 8.3.1 Image dimensions | 14 | +| 8.3.2 Pel spacing | 15 | +| 8.3.3 Spacing ratio | 15 | +| 8.4 Content architecture class attributes | 15 | +| 8.4.1 Content architecture class | 15 | + +| | | | +|---------|---------------------------------------------------------------------------------|----| +| 9 | Definition of raster graphics content portion attributes | 16 | +| 9.1 | Common coding attributes | 16 | +| 9.1.1 | Type of coding | 16 | +| 9.2 | Other coding attributes | 17 | +| 9.2.1 | Compression | 17 | +| 9.2.2 | Number of lines | 18 | +| 9.2.3 | Number of pels per line | 18 | +| 9.2.4 | Number of discarded pels | 19 | +| 9.2.5 | Number of lines per tile | 19 | +| 9.2.6 | Number of pels per tile line | 19 | +| 9.2.7 | Tiling offset | 19 | +| 9.2.8 | Tile types | 20 | +| 9.2.9 | Bits per colour component | 20 | +| 9.2.10 | Interleaving format | 21 | +| 9.3 | Content information attributes | 21 | +| 9.4 | Interactions with document architecture attributes | 21 | +| 10 | Formal definitions of raster graphics content architecture dependent data types | 21 | +| 10.1 | Introduction | 21 | +| 10.2 | Representation of presentation attributes | 22 | +| 10.3 | Representation of coding attributes | 23 | +| 10.4 | Representation of non-basic features and non-standard defaults | 24 | +| 11 | Coding schemes | 25 | +| 11.1 | CCITT Rec. T.6 encoding scheme | 25 | +| 11.2 | CCITT Rec. T.4 encoding schemes | 25 | +| 11.3 | Bitmap encoding scheme | 26 | +| 11.4 | Tiled encoding scheme | 26 | +| 11.5 | Direct value encoding scheme | 27 | +| 11.6 | Octet run-length encoding scheme | 27 | +| 11.7 | Packed index encoding scheme | 27 | +| 12 | Content layout process | 28 | +| 12.1 | Introduction | 28 | +| 12.1.1 | Purpose | 28 | +| 12.1.2 | Available area | 28 | +| 12.1.3 | Presentation attributes | 28 | +| 12.1.4 | Coding attributes | 28 | +| 12.1.5 | Raster graphics content architecture classes | 28 | +| 12.1.6 | Layout of the content | 29 | +| 12.2 | Notation | 29 | +| 12.3 | The fixed dimension content layout method | 29 | +| 12.4 | The scalable dimension content layout method | 30 | +| 13 | Content imaging process | 31 | +| 13.1 | Introduction | 36 | +| 13.2 | Content imaging process for formatted form | 36 | +| 13.3 | Content imaging process for formatted processable form | 36 | +| 14 | Definition of raster graphics content architecture classes | 36 | +| 14.1 | Summary of raster graphics presentation attributes | 36 | +| 14.2 | Summary of raster graphic content portion attributes | 37 | +| Annex A | – Summary of raster graphics content architecture classes | 38 | +| A.1 | Formatted raster graphics content architecture class | 38 | +| A.1.1 | Presentation attributes | 38 | +| A.1.2 | Content portion attributes | 38 | +| A.2 | Formatted processable raster graphics content architecture class | 39 | +| A.2.1 | Presentation attributes | 39 | +| A.2.2 | Content portion attributes | 40 | +| Annex B | – Summary of ASN.1 object identifiers | 41 | +| Annex C | – SGML representation of raster graphics content-specific attributes for ODL | 42 | + +| | | | +|-------|--------------------------------------------------------------|----| +| C.1 | Introduction | 42 | +| C.2 | Names and public identifiers | 42 | +| C.3 | Representation of attribute values | 42 | +| C.3.1 | Constructed parameters | 42 | +| C.3.2 | String parameters | 42 | +| C.3.3 | Keyword parameters | 43 | +| C.3.4 | Integer parameters | 43 | +| C.4 | Presentation attributes | 43 | +| C.4.1 | Shared presentation attributes (format attribute-directives) | 43 | +| C.4.2 | Layout presentation attributes (formal attributes) | 43 | +| C.4.3 | Logical presentation attributes (format directives) | 43 | +| C.5 | Coding attributes | 44 | +| Index | | 45 | + +# LIST OF TABLES + +| | <i>Page</i> | +|---------------------------------------------------------------------------------------------------------|-------------| +| Table 1 – Raster graphics presentation attributes | 11 | +| Table 2 – Default values of the presentation attribute “initial offset” (position of initial point) | 13 | +| Table 3 – Relation of pel spacing and line spacing to resolution | 13 | +| Table 4 – Default value of the presentation attribute “number of pels per line” | 18 | +| Table 5 – Dimensions of basic layout object | 29 | +| Table 6 – Raster graphics presentation attributes | 37 | +| Table 7 – Raster graphics content portion attributes | 37 | +| Table A.1 – Formatted raster graphics content architecture class presentation attributes | 38 | +| Table A.2 – Formatted processable raster graphics content architecture class content portion attributes | 38 | +| Table A.3 – Formatted processable raster graphics content architecture class presentation attributes | 39 | +| Table A.4 – Formatted processable raster graphics content architecture class content portion attributes | 40 | +| Table B.1 – Summary of ASN.1 object identifiers | 41 | + +# LIST OF FIGURES + +| | <i>Page</i> | +|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| Figure 1 – Relationships among the colour spaces for the Raster Graphics Content Architecture | 5 | +| Figure 2 – Example of direction | 6 | +| Figure 3 – Example of clipping a content portion | 7 | +| Figure 4 – Location of the pel array in the set of tiles | 8 | +| Figure 5 – Example of the tile content ordering | 8 | +| Figure 6 – Positioning of pels of the clipped pel array within a basic layout object | 9 | +| Figure 7 – Diagrams used to illustrate the process of determining the basic layout object dimensions | 32 | +| Figure 8 – Layout process for the presentation attribute “image dimensions” when a value is specified for the parameter “automatic” | 33 | +| Figure 9 – Layout process for the presentation attribute “image dimensions” when a value is specified for the parameter “width controlled” or “height controlled” | 34 | +| Figure 10 – Layout process for the presentation attribute “image dimensions” when a value is specified for the parameter “area controlled” | 35 | + +# **SUMMARY** + +This Recommendation is one of the Recommendations of the T.410-Series. It defines the raster graphics content architecture used to include images in a document. Image coding methods used in the raster graphics content architecture include methods used in the facsimile environments as well as methods used in non-facsimile environments. + +# **INTRODUCTION** + +This ITU-T Recommendation | International Standard was prepared as a joint publication by ITU-T Study Group 8 and ISO/IEC Joint Technical Committee 1. + +At present, the ITU-T Recommendation T.410-Series | ISO/IEC 8613 consists of: + +- Introduction and general principles; +- Document structures; +- Document profile; +- Open document interchange formats; +- Character content architectures; +- Raster graphics content architectures; +- Geometric graphics content architectures; +- Formal Specification of the Open Document Architecture (FODA) + +NOTE – The use of FODA is applicable to ISO/IEC only. + +Further Specifications may be added to this set of ITU-T Recommendations | International Standard. + +Development of these Recommendations | International Standard was originally in parallel with ECMA 101:1989, Open Document Architecture. + +This set of ITU-T Recommendations | International Standard replaces the CCITT T.410-Series of Recommendations (1988) and ISO 8613:1989. + +Significant technical changes are the inclusion in this Recommendation | International Standard of the following amendments as agreed by ITU-TS and ISO/IEC JTC 1: + +- Tiled raster graphics; +- Colour. + +In addition, a number of technical corrigenda have been applied to the Specification. + +This part contains three annexes: + +- Annex A (integral) contains a summary of the raster graphics content architecture classes; +- Annex B (non-integral) lists the ASN.1 object identifiers used by the raster graphics content architecture; +- Annex C (integral to ISO/IEC only) contains ODL, the SGML representation of the attributes specific to raster graphics content architectures. + +## **INTERNATIONAL STANDARD** + +## **ITU-T RECOMMENDATION** + +## INFORMATION TECHNOLOGY – OPEN DOCUMENT ARCHITECTURE (ODA) AND INTERCHANGE FORMAT: RASTER GRAPHICS CONTENT ARCHITECTURES + +# **1 Scope** + +The purpose of the ITU-T Rec. T.410-Series | ISO/IEC 8613 is to facilitate the interchange of documents. + +In the context of these Recommendations | International Standards, documents are considered to be items such as memoranda, letters, invoices, forms and reports, which may include pictures and tabular material. The content elements used within the documents may include graphic characters, geometric graphics elements and raster graphics elements, all potentially within one document. + +NOTE – These Recommendations | International Standards are designed to allow for extensions, including hypermedia features, spreadsheets and additional types of content such as audio and video. + +In addition to the content types defined in these specifications, ODA also provides for arbitrary content types to be included in documents. + +These Recommendations | International Standards apply to the interchange of documents by means of data communications or the exchange of storage media. + +These Recommendations | International Standards provide for the interchange of documents for either or both of the following purposes: + +- to allow presentation as intended by the originator; +- to allow processing such as editing and reformatting. + +The composition of a document in interchange can take several forms: + +- formatted form, allowing presentation of the document; +- processable form, allowing processing of the document; +- formatted processable form, allowing both presentation and processing. + +These Recommendations | International Standards also provide for the interchange of ODA information structures used for the processing of interchanged documents. + +This ITU-T Recommendation | International Standard defines: + +- the raster graphics content architectures that can be used in conjunction with the document architecture defined in ITU-T Rec. T.412 | ISO/IEC 8613-2; +- the internal structure of content portions that are structured according to a raster graphics content architecture; +- those aspects of positioning and imaging applicable to the presentation of raster graphics contents in a basic layout object; +- a content layout process which, together with the document layout process defined in ITU-T Rec. T.412 | ISO/IEC 8613-2, specifies the method for determining the dimensions of basic layout objects for raster graphics content portions; +- the presentation and content portion attributes applicable to raster graphics content architectures. + +# **2 Normative references** + +The following ITU-T Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently + +valid International Standards. The ITU-T Secretariat maintains a list of currently valid ITU-T Recommendations/CCITT Recommendations. + +## 2.1 Identical Recommendations | International Standards + +- ITU-T Recommendation T.411 (1992) | ISO/IEC 8613-1:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Introduction and general principles.* +- ITU-T Recommendation T.412 (1992) | ISO/IEC 8613-2:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Document structures.* +- ITU-T Recommendation T.414 (1992) | ISO/IEC 8613-4:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Document profile.* +- ITU-T Recommendation T.415 (1992) | ISO/IEC 8613-5:1994, *Information technology – Open Document Architecture (ODA) and interchange format: Open Document Interchange Format.* + +## 2.2 Paired Recommendations | International Standards equivalent in technical content + +- CCITT Rec. X.208 (1988), *Specification of abstract syntax notation one (ASN.1).* +ISO/IEC 8824:1990, *Information technology – Open Systems Interconnection – Specification of Abstract Syntax Notation One (ASN.1).* +- CCITT Rec. X.209 (1988), *Specification of basic encoding rules for Abstract Syntax Notation One (ASN.1).* +ISO/IEC 8825:1990, *Information technology – Open Systems Interconnection – Specification of Basic Encoding Rules for Abstract Syntax Notation One (ASN.1).* + +## 2.3 Additional references + +- ITU-T Recommendation T.4 (1993), *Standardization of Group 3 facsimile apparatus for document transmission.* +- CCITT Recommendation T.6 (1992), *Facsimile coding schemes and coding control functions for Group 4 facsimile apparatus.* +- ISO 8879:1986, *Information processing – Text and office systems – Standard Generalized Markup Language (SGML).* + +# 3 Definitions + +For the purposes of this Recommendation | International Standard, the definitions given in ITU-T Rec. T.411 | ISO/IEC 8613-1 apply. For the purpose of this Specification the definitions in CCITT Recommendations T.4 and T.6 apply. + +# 4 Abbreviations + +For the purposes of this Recommendation | International Standard, the abbreviations in ITU-T Rec. T.411 | ISO/IEC 8613-1 apply. + +For the purposes of this Recommendation | International Standard, the following additional abbreviations apply. + +| | | +|------|----------------------------------------------| +| AAH | Horizontal dimension of available area | +| AAV | Vertical dimension of available area | +| BDH | Horizontal block dimension | +| BDV | Vertical block dimension | +| EOFB | End-of-facsimile-block | +| MSB | Most significant bit | +| NLC | Number of lines of the clipped array | +| NPC | Number of pels per line of the clipped array | +| PS | Pel spacing | +| RTC | Return-to-control | + +SR                      Spacing ratio + +# 5 Conventions + +For the purposes of this Recommendation | International Standard, the conventions given in ITU-T Rec. T.411 | ISO 8613-1 apply. + +# 6 General principles + +## 6.1 Content architecture classes + +This Specification defines two classes of raster graphics content architectures: + +- Formatted raster graphics content architecture class, which allows for document content to be presented as intended by the originator. Formatted form content can only be associated with basic layout components. +- Formatted processable raster graphics content architecture class, which allows for document content to be processed and also to be presented as intended by the originator. Formatted processable content can be associated with any basic component. + +### 6.1.1 Formatted content architecture class + +Formatted raster graphics content is intended to be laid out, or imaged, by the recipient in accordance with the originator's intent. It is not intended to be reformatted. This form of content may only be used in formatted form documents. + +For this form of content all the necessary information for positioning of pels has been specified. The method of positioning is specified in clause 8. + +A particular feature of this form of content is that the position of the pel array can be offset relative to the position of the basic layout object. As a result, it is possible that not all of the area of the basic layout object is utilized for positioning pels. A portion of the pel array may also be positioned such that it is outside the basic layout object. Such a portion, if any, is not imaged. + +### 6.1.2 Formatted processable content architecture class + +Formatted processable raster graphics content is intended to be laid out, reformatted or imaged by the recipient in accordance with the originator's intent. This form of content may be used in formatted, processable and formatted processable form documents. + +The originator may, when using this form of content, specify the precise requirements for the layout and imaging of the pel array. Alternatively, the originator may specify various constraints concerning the intended layout and imaging of the pel array, i.e. the precise requirements are not specified and the layout is determined by the content layout process performed by the recipient. + +When the precise requirements for the layout are specified, the fixed dimension layout method is used to layout and image the content. Otherwise, the content is laid out and imaged using the scalable dimension layout method. These layout methods are defined in clause 12. + +A particular feature of these layout methods is that in both cases the content is laid out such that the entire basic layout object is utilized. In addition it is possible to specify that only a portion of the pel array is to be laid out. + +## 6.2 Content + +There are two modes, named *binary* and *colour*, for determining the image of a pel. Each encoding scheme defined in clause 11 corresponds to just one mode. + +### 6.2.1 Binary mode + +In the binary mode, the data which determines the image of a pel specifies one of the two states, named *set* and *unset*. The set state indicates that the colour specified in the attribute "content foreground colour" applying to the object to which the content is associated is to be used. The unset state indicates that the colour specified in the attribute "content background colour" applying to the object to which the content is associated is to be used. Both attributes are defined in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +NOTE – According to ITU-T Rec. T.414 | ISO/IEC 8613-4, all of the colour space types RGB, CMY(K), CIELUV, and CIELAB are permitted. + +### **6.2.2 Colour mode** + +In the colour mode, the colour of the image of a pel is specified in the pel encoding. + +The attribute “content background colour” applying to the object with which the content is associated is ignored. The attribute “content foreground colour” applying to the object with which the content is associated is used in some encoding schemes to derive the reference to the applying colour space and the colour tolerance specification (see clause 11). + +NOTE – According to ITU-T Rec. T.414 | ISO/IEC 8613-4, all of the colour space types RGB, CMY(K), CIELUV, and CIELAB are permitted. + +## **6.3 Presentation attributes** + +Presentation attributes are applicable to basic components and specify information for laying out and imaging the content of the basic component, and are defined in clause 7. This information cannot be modified within the content of the basic component to which it applies. + +All raster graphics content presentation attributes are: + +- non-mandatory when specified for presentation styles; +- non-mandatory when applied to object class descriptions; +- defaultable when applied to object descriptions. + +Presentation attributes are classified as shared attributes, layout attributes or logical attributes: + +- shared attributes are applicable to logical and layout components; +- layout attributes are applicable only to layout components; +- logical attributes are applicable only to logical components. + +## **6.4 Content portion attributes** + +Content portion attributes are applicable to content portions and specify information related to the identification and coding of the content. They are also used in laying out and imaging the content of the content portion. Content portion attributes are defined in clause 9. + +## **6.5 Coding of content information** + +The methods of encoding the pel array in a content portion structured according to a raster graphics content architecture are specified in clause 11. + +## **6.6 Picture element (pel) array** + +The picture elements in an array have a defined order. The array consists of an ordered sequence of rows of picture elements. Each row in the array contains the same number of picture elements and consists of an ordered sequence of picture elements that represents a line of the image. + +## 6.7 Colour spaces applicable to the raster graphics content architecture + +The raster graphics content architecture can employ colour specification in CIELUV, CIELAB, RGB or CMY(K) (see Figure 1). Colour may be specified in either direct mode or indexed mode. + +![Figure 1: Relationships among the colour spaces for the raster graphics content architecture. The diagram shows four input boxes at the top: RGB, CMY(K), CIELUV, and CIELAB. Arrows from these boxes point to a central box labeled 'Reference CIE XYZ'. This central box is positioned between two horizontal dashed lines. The top dashed line is labeled 'Optional transformation' and the bottom dashed line is labeled 'Content imaging transformation'. Arrows from the 'Reference CIE XYZ' box point down to a final box at the bottom labeled 'Imaging system colour space'. The entire top section is labeled 'Raster graphics content architecture'.](5a4e62bead259c258d069fd3663ea670_img.jpg) + +``` + +graph TD + subgraph "Raster graphics content architecture" + RGB[RGB] + CMYK["CMY(K)"] + CIELUV[CIELUV] + CIELAB[CIELAB] + XYZ[Reference CIE XYZ] + end + RGB --> XYZ + CMYK --> XYZ + CIELUV --> XYZ + CIELAB --> XYZ + XYZ --> ISSC[Imaging system colour space] + + OT[Optional transformation] -.- XYZ + XYZ -.- CIT[Content imaging transformation] + +``` + +T0816820-94/d01 + +Figure 1: Relationships among the colour spaces for the raster graphics content architecture. The diagram shows four input boxes at the top: RGB, CMY(K), CIELUV, and CIELAB. Arrows from these boxes point to a central box labeled 'Reference CIE XYZ'. This central box is positioned between two horizontal dashed lines. The top dashed line is labeled 'Optional transformation' and the bottom dashed line is labeled 'Content imaging transformation'. Arrows from the 'Reference CIE XYZ' box point down to a final box at the bottom labeled 'Imaging system colour space'. The entire top section is labeled 'Raster graphics content architecture'. + +**Figure 1 – Relationships among the colour spaces for the raster graphics content architecture** + +In order to support colour, the data which determine the image of a pel are separated into colour components. Each colour component corresponds to one dimension of the colour space in which the image is specified. For example, for an image specified in CIELUV in direct mode, the data for each pel comprise three colour components representing $L^*$ , $u^*$ and $v^*$ values. + +**NOTE** – Additional compression techniques are required for compression of colour images. A basic run-length compression is defined in this version of the ITU-T Rec. T.410-Series | ISO 8613, and it is anticipated that further techniques will be specified in later versions. An example might be the use of sub-sampling of the $u^*$ and $v^*$ components in CIELUV. Such techniques may require parameters specific to them, in which case it will be necessary to introduce an attribute for this purpose. + +# 7 Principles of positioning pels + +Two methods of positioning pels within a basic layout object are described in this clause. One of these applies to content portions which pertain to the formatted content architecture class. The other applies to content portions which pertain to the formatted processable form content architecture class. + +The general principles of positioning that apply to both these methods are described in 7.5.1. Subsequently, 7.5.2 and 7.5.3 describe the specific principles that apply to the formatted and formatted processable content architecture class. + +A basic logical component with a formatted processable content architecture class must undergo the content layout process before it can be positioned and imaged. The content layout process (defined in clause 12) determines the block size into which the content portion is to be imaged. The content is then positioned in accordance with the positioning rules for content pertaining to the formatted processable content architecture class. + +Any parts of a raster graphics content portion which extend beyond the boundaries of the basic layout object are not imaged. + +## 7.1 Basic concepts + +### 7.1.1 Measurement units and directions + +For raster graphics content, the unit for positioning pels is the Scaled Measurement Unit (SMU). + +The SMU is derived from the Basic Measurement Unit BMU by multiplying the BMU with a factor which is specified by the attribute “unit scaling” (defined in ITU-T Rec. T.414 | ISO/IEC 8613-4). The BMU and SMU are defined in ITU-T Recommendation T.412 | ISO/IEC 8613-2. + +All directions are expressed as counter clockwise angles of rotation relative to some specified reference direction (as illustrated in Figure 2). + +![Figure 2: Example of direction. The diagram shows a horizontal arrow pointing right labeled 'Reference direction'. A vertical arrow points down from the end of the reference direction. A curved arrow indicates a counter-clockwise rotation from the reference direction to the vertical arrow. A label 'Angle of rotation' points to this curved arrow. Below the vertical arrow, the text 'Direction = 270 deg.' is written. In the bottom right corner, the identifier 'T0816880-94/d02' is present.](e3b8510f6a2194e250205ab7bc38076d_img.jpg) + +Figure 2: Example of direction. The diagram shows a horizontal arrow pointing right labeled 'Reference direction'. A vertical arrow points down from the end of the reference direction. A curved arrow indicates a counter-clockwise rotation from the reference direction to the vertical arrow. A label 'Angle of rotation' points to this curved arrow. Below the vertical arrow, the text 'Direction = 270 deg.' is written. In the bottom right corner, the identifier 'T0816880-94/d02' is present. + +Figure 2 – Example of direction + +### 7.1.2 Coordinate systems + +Two rectangular coordinate systems are used in the positioning of pels. + +One system is a dimensionless coordinate system used to identify the pels that constitute a clipped pel array (defined in 7.3.1). In this system, the origin of the coordinate system is positioned at the first pel in the pel array. One axis is in the direction of the pels in each row of pels. The second axis is in the direction of the columns of pels. This system uses non-negative dimensionless integer values. Coordinate pairs are denoted using upper case letters. + +The second system is used for the positioning of pels associated with basic layout objects. In this system, one axis is parallel to the horizontal axis of the page coordinate system (defined in ITU-T Rec. T.412 | ISO/IEC 8613-2) and the other axis is in a direction d270 relative to the horizontal axis. This system uses rational values in scaled measurements units (SMUs) to identify points or specify lengths within a basic layout object. Coordinate pairs are indicated by lower case letters. + +## 7.2 Pel image model + +Each pel is associated with a *reference area*. The side of the reference area along the direction of the pel path equals the pel spacing and the side along the direction of line progression equals the line spacing. + +Each reference area has a *reference point*, which is used for positioning the pel. The reference point is defined as the corner of the reference area situated in the direction opposite to both pel path and line progression. The position of a pel in a basic layout object is defined as the position of the reference point of the reference area of that pel. + +NOTE – The position of the image of the pel relative to the reference area is implementation dependent, but it is the intention that the main part of the image of the pel is positioned within the reference area. + +## 7.3 Positioning of pels + +In general, when positioning (and subsequently imaging) the content of a content portion in relation to a basic layout object, only part of the content is considered. Two methods of selecting the required part of the content are provided: + +- specification of a clipped pel array; +- discarding of pels. + +### 7.3.1 The clipped pel array + +The clipped pel array is a rectangular array of pels defined by two coordinate pairs in the dimensionless coordinate system. The diagonally opposite pairs of the clipped pel array are identified by the coordinate pairs (X1, Y1) and (X2, Y2) where $X1 \leq X2$ and $Y1 \leq Y2$ . Figure 3 illustrates the clipping of a content portion. + +![Diagram illustrating the clipping of a content portion from a pel array. A large grid of dots represents the pel array. A smaller rectangle, labeled 'Content portion', is defined by coordinates (X1, Y1) and (X2, Y2). A third, shaded rectangle, labeled 'Clipped pel array', is shown below, representing the result of clipping the content portion. Arrows indicate the mapping from the content portion to the clipped array. The origin (0,0) is marked at the top-left of the grid. A reference code 'T0816890-94/d03' is present at the bottom right of the diagram area.](4e4be0bd8b235167902f2c03e41da651_img.jpg) + +(0, 0) → + +(X1, Y1) + +Content portion + +(X2, Y2) + +Clipped pel array + +T0816890-94/d03 + +(X1, Y1) “Clipping” first coordinate pair +(X2, Y2) “Clipping” second coordinate pair + +Diagram illustrating the clipping of a content portion from a pel array. A large grid of dots represents the pel array. A smaller rectangle, labeled 'Content portion', is defined by coordinates (X1, Y1) and (X2, Y2). A third, shaded rectangle, labeled 'Clipped pel array', is shown below, representing the result of clipping the content portion. Arrows indicate the mapping from the content portion to the clipped array. The origin (0,0) is marked at the top-left of the grid. A reference code 'T0816890-94/d03' is present at the bottom right of the diagram area. + +**Figure 3 – Example of clipping a content portion** + +### 7.3.2 Discarded pels + +In the formatted raster graphics content architecture class, the number of pels to be discarded at the beginning and the end of each line of pels can be specified by a coding attribute. + +## 7.4 Tiling + +The pel array may be segmented into a two-dimensional array of non-overlapping rectangular regions called *tiles*. The content information of each tile is coded independently of the coding of the content information of the other tiles of the same pel array. + +Tiling facilitates convenient access to, and/or processing of portions of the pel array independent of access to, and/or processing of other portions. The capability to encode each tile separately as bitmap, compressed or null maximizes the possible compression of the tiled pel array. + +NOTE 1 – Tiling provides an alternative method for coding of raster graphics content and therefore does not affect the positioning of the clipped pel array. + +The basic concepts, pel image model and positioning of pels in a basic layout object continue to apply. Furthermore the attributes for pel array clipping continue to apply to the pel array. + +The location of pel array content relative to the tile content is specified by the “tiling offset” attribute. Figure 4 illustrates the location of the pel array in the set of tiles. + +Tiled raster graphics content information consists of a sequence of tiles ordered in the direction of the pel path and line progression as illustrated in Figure 5. + +The content of each tile may be encoded according to ITU-T Recs. T.4, T.6, T.4 – MSB, T.6 – MSB or bitmap encoded as specified by the coding attributes. Alternatively, it may be omitted if the pels within the tile are either all foreground or all background. + +NOTE 2 – Rec. T.6 encoding – MSB and Rec. T.4 encodings – MSB apply to ITU-TS only. + +![Diagram illustrating the location of the pel array in the set of tiles. It shows a grid of tiles with a 'Pel array' highlighted in one tile. Labels include 'Number of pels per line', 'Number of pels per tile line', 'Tiling offset', '(0, 0)', 'Clipped pel array', 'Content portion', 'Number of lines', and 'Number of lines per tile'. A reference code T0804940-90/d04 is at the bottom right.](b9ecbc3baefab13719e000faa6e0c7eb_img.jpg) + +Number of pels per line + +Number of pels per tile line + +Pel array + +Content portion + +Tiling offset + +(0, 0) + +Clipped pel array + +Number of lines + +Number of lines per tile + +T0804940-90/d04 + +Diagram illustrating the location of the pel array in the set of tiles. It shows a grid of tiles with a 'Pel array' highlighted in one tile. Labels include 'Number of pels per line', 'Number of pels per tile line', 'Tiling offset', '(0, 0)', 'Clipped pel array', 'Content portion', 'Number of lines', and 'Number of lines per tile'. A reference code T0804940-90/d04 is at the bottom right. + +Figure 4 – Location of the pel array in the set of tiles + +![Diagram illustrating tile content ordering. A 5x4 grid of tiles is shown with a 'Pel path' arrow pointing right and a 'Line progression' arrow pointing down. The tiles are numbered 1 to 20 in row-major order. A reference code T0804950-90/d05 is at the bottom right.](a33da0f14e456f92539ce3e9b7d81f9a_img.jpg) + +Pel path + +Line progression + +| | | | | +|----|----|----|----| +| 1 | 2 | 3 | 4 | +| 5 | 6 | 7 | 8 | +| 9 | 10 | 11 | 12 | +| 13 | 14 | 15 | 16 | +| 17 | 18 | 19 | 20 | + +T0804950-90/d05 + +Diagram illustrating tile content ordering. A 5x4 grid of tiles is shown with a 'Pel path' arrow pointing right and a 'Line progression' arrow pointing down. The tiles are numbered 1 to 20 in row-major order. A reference code T0804950-90/d05 is at the bottom right. + +Figure 5 – Example of tile content ordering + +## 7.5 Positioning of pels in a basic layout object + +### 7.5.1 Positioning parameters + +As illustrated in Figure 6, the positioning of pels within a basic layout object is determined by the following parameters: + +- initial point; +- pel path; +- line progression; + +- pel spacing; +- line spacing. + +![Diagram illustrating the positioning of pels of a clipped pel array within a basic layout object. It shows a rectangular layout object with a horizontal axis at the top and a vertical axis on the left. Inside, a grid of black dots (pels) is shown. An 'Initial point' is marked at the top-left of the grid, defined by horizontal distance 'h' and vertical distance 'v' from the 'Reference point of basic layout object'. Arrows indicate 'Pel path' (horizontal to the right) and 'Line progression' (vertical downwards). 'Pel spacing' is the horizontal distance between dots, and 'Line spacing' is the vertical distance between rows of dots. A single pel is highlighted with a grey square labeled 'Reference point of a pel'.](724c7777b608e53be38b12b6fb3c43bc_img.jpg) + +Diagram illustrating the positioning of pels of a clipped pel array within a basic layout object. It shows a rectangular layout object with a horizontal axis at the top and a vertical axis on the left. Inside, a grid of black dots (pels) is shown. An 'Initial point' is marked at the top-left of the grid, defined by horizontal distance 'h' and vertical distance 'v' from the 'Reference point of basic layout object'. Arrows indicate 'Pel path' (horizontal to the right) and 'Line progression' (vertical downwards). 'Pel spacing' is the horizontal distance between dots, and 'Line spacing' is the vertical distance between rows of dots. A single pel is highlighted with a grey square labeled 'Reference point of a pel'. + +- v Vertical coordinate of initial point +- h Horizontal coordinate of initial point +- ![Shaded square representing reference area of a pel](439c03ca276a335a90a4e7ed2b3945c1_img.jpg) Reference area of a pel + +**Figure 6 – Positioning of pels of the clipped pel array within a basic layout object** + +These properties of a raster image remain constant within the content associated with a particular basic layout object. + +The general use of these properties when positioning pels is described below and illustrated in Figure 6. The particular applicability of these parameters to formatted and formatted processable form content is described in 7.5.2 and 7.5.3 respectively. + +The *initial point* is the point relative to which all pels are positioned within a basic layout object. + +The value of the initial point is a coordinate pair $(h,v)$ , where $h$ and $v$ are the horizontal and vertical distances respectively, of the initial point from the reference point of the basic layout object. + +The *pel path* is the direction of progression of successive pels along a line and is expressed as a direction relative to the horizontal axis of the page coordinate system (as defined in ITU-T Rec. T.412 | ISO/IEC 8613-2). + +*Line progression* is the direction of progression of successive lines and is expressed as a direction relative to the pel path. + +*Lines of pels* are positioned such that the first pel to be positioned on each line falls on an imaginary line through the initial point in the direction of line progression. + +The *pel spacing* is the distance between two adjacent pels along a line in the direction of the pel path. + +The *line spacing* is the distance between adjacent pels in the direction of line progression. The line spacing may be less than, greater than or equal to the pel spacing. + +The *spacing ratio* is defined as the ratio of the line spacing to the pel spacing. + +The *aspect ratio* of a clipped pel array that has been positioned in a basic layout object is defined as the ratio of the dimension of the pel array in the direction of the pel path to the dimension in the direction of line progression. + +The first pel of the clipped pel array is positioned at the initial point. + +Each pel on the first line is positioned along a line through the initial point in the direction of the pel path. + +The first pel of each line is positioned along a line through the initial point in the direction of line progression. + +### **7.5.2 Positioning rules for formatted content** + +For this form of content, the positioning parameters are explicitly specified by applicable presentation attributes (see clause 8). + +It is not possible to define a clipped pel array when using this form of content. However, a coding attribute can be used to indicate that a specified number of pels are to be discarded at the beginning and end of each line of the content portion. In this case, only the remaining pels in the content position are considered for positioning. + +The line spacing and pel spacing are both specified by the same presentation attribute, and take the same value from the limited set of values specified in 8.2.2. + +The initial point can be positioned anywhere inside or outside the basic layout object. Its default position (see 8.2.1) is the corner of the basic layout object in the direction opposite to both pel path and line progression. + +All the pels within a content portion are to be considered for positioning (apart from any pels that are to be discarded). However, pels that would be positioned outside the basic layout object are not to be imaged by the imaging process. + +### **7.5.3 Positioning rules for formatted processable content** + +For this form of content, the positioning parameters are determined from information specified in presentation and coding attributes and from the dimensions of the basic layout object. + +The clipped pel array is specified by a presentation attribute, which selects the portion of the content portion to be positioned. + +The pel path and line progression are explicitly specified by presentation attributes. The initial point is determined from the pel path and line progression specified, such that it is situated in the corner of the basic layout object in the direction opposite to both pel path and line progression (see Table 2); other values for the initial point cannot be specified. + +The pel spacing is set to be equal to the dimension of the basic layout object in the direction of the pel path divided by the number of pels per line in the clipped pel array. Similarly, the line spacing is set to be equal to the dimension of the basic layout object in the direction of line progression divided by the number of lines in the clipped pel array. + +Thus the clipped pel array is positioned within the basic layout object such that the reference areas of all the pels completely fill the basic layout object. None of the pels in the clipped pel array may be positioned outside of the basic layout object. + +# **8 Definition of raster graphics presentation attributes** + +Presentation attributes specify the initial conditions relating to the layout and imaging of the content of a basic component. They may be specified for basic logical and layout components and for presentation styles. + +There are three categories of raster graphics presentation attributes: + +- Logical presentation attributes which take effect during the content layout process, but are ignored during the content imaging process. +- Layout presentation attributes which take effect during the content imaging process. Their values are generated either by the content layout process, or by a process that creates or edits the content. +- Shared presentation attributes which take effect during either or both the content layout and imaging processes. + +These attributes are listed in Table 1. + +**Table 1 – Raster graphics presentation attributes** + +| Shared attributes | Layout attributes | Logical attributes | +|-------------------|--------------------------|--------------------| +| Pel path | Pel transmission density | Pel spacing | +| Line progression | Initial offset | Spacing ratio | +| Clipping | | Image dimensions | + +For each presentation attribute a default value is defined. This value is used in the defaulting mechanism as defined in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +This clause also defines values specific to raster graphics content architectures for the attribute “content architecture class” as defined in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +## **8.1 Shared presentation attributes** + +### **8.1.1 Clipping** + +| | | | +|---------------------|--------------------------------------------------|-------------------------------------------------------------------------------------| +| CATEGORY: | Shared | | +| APPLICABILITY: | Formatted processable content architecture class | | +| STRUCTURE: | First coordinate pair: | X coordinate,<br>Y coordinate | +| | second coordinate pair: | X coordinate,<br>Y coordinate | +| PERMISSIBLE VALUES: | First coordinate pair: | non-negative integer,<br>non-negative integer | +| | second coordinate pair: | non-negative integer,<br>non-negative integer | +| DEFAULT VALUES: | First coordinate pair: | (0,0) | +| | second coordinate pair: | (N-1,L-1)<br>where:<br>N is the number of pels per line<br>L is the number of lines | + +#### **DEFINITION:** + +This attribute determines the sub-region of the pel array, as described by the content portion, which is to be considered by the content layout process and the content imaging process. + +This attribute consists of two coordinate pairs. The first pair specifies the first pel that is part of the selected array. The second pair specifies the last pel that is part of the selected array. + +Each coordinate of the first pair shall be less than or equal to the corresponding coordinate of the second pair. + +### **8.1.2 Line progression** + +| | | +|---------------------|---------------------------------------------------------------------| +| CATEGORY: | Shared | +| APPLICABILITY: | Formatted and formatted processable<br>content architecture classes | +| PERMISSIBLE VALUES: | d90, d270 | +| DEFAULT VALUE: | d270 | + +#### **DEFINITION:** + +This attribute specifies the direction of the progression of successive lines, relative to the pel path. + +### **8.1.3 Pel path** + +| | | +|-----------|--------| +| CATEGORY: | Shared | +|-----------|--------| + +| | | +|---------------------|------------------------------------------------------------------| +| APPLICABILITY: | Formatted and formatted processable content architecture classes | +| PERMISSIBLE VALUES: | d0, d90, d180, d270 | +| DEFAULT VALUE: | d0 | + +#### DEFINITION: + +This attribute specifies the direction of the progression of successive pels along a line, relative to the horizontal axis of the basic layout object. + +## 8.2 Layout presentation attributes + +### 8.2.1 Initial offset + +| | | | +|---------------------|--------------------------------------------------------------------------------------------------------|---------------------------------------------------| +| CATEGORY: | Layout | | +| APPLICABILITY: | Formatted content architecture class | | +| STRUCTURE: | Two parameters: | “horizontal coordinate”,<br>“vertical coordinate” | +| PERMISSIBLE VALUES: | horizontal coordinate:<br>vertical coordinate: | any integer<br>any integer | +| DEFAULT VALUES: | The default value of this attribute depends on the pel path and line progression as defined in Table 2 | | + +#### DEFINITION: + +This attribute specifies the position of the initial point relative to the basic layout object. + +The parameters “horizontal coordinate” and “vertical coordinate” specify the horizontal and vertical coordinates, in SMUs, of the initial point relative to the reference point of the basic layout object. The value of each coordinate should be positive or zero. + +NOTE – The facility to specify negative coordinate values for the initial point is not intended to be used. It was provided for use with content architectures based on CCITT Recommendation T.73, which is no longer valid. + +**Table 2 – Default values of the presentation attribute “initial offset” +(position of initial point)** + +| Pel path | Line progression | Horizontal coordinate (SMU) | Vertical coordinate (SMU) | +|-----------------------------------|------------------|-----------------------------|---------------------------| +| d0 | d270 | 0 | 0 | +| | d90 | 0 | BDV | +| d270 | d270 | BDH | 0 | +| | d90 | 0 | 0 | +| d180 | d270 | BDH | BDV | +| | d90 | BDH | 0 | +| d90 | d270 | 0 | BDV | +| | d90 | BDH | BDV | +| BDV Vertical dimension of block | | | | +| BDH Horizontal dimension of block | | | | + +### **8.2.2 Pel transmission density** + +| | | +|---------------------|--------------------------------------| +| CATEGORY: | Layout | +| APPLICABILITY: | Formatted content architecture class | +| PERMISSIBLE VALUES: | 1, 2, 3, 4, 5, 6 BMU | +| DEFAULT VALUE: | 6 BMU | + +#### DEFINITION: + +This attribute specifies a single value for both the pel spacing and the line spacing + +NOTE – The correspondence between pel spacing, line spacing and resolution is shown in Table 3. + +**Table 3 – Relation of pel spacing and line spacing to resolution** + +| Pel spacing and line spacing<br>in BMU | Resolution in number of pels<br>per 1 200 BMU | +|----------------------------------------|-----------------------------------------------| +| 6 | 200 | +| 5 | 240 | +| 4 | 300 | +| 3 | 400 | +| 2 | 600 | +| 1 | 1 200 | + +## **8.3 Logical presentation attributes** + +### **8.3.1 Image dimensions** + +| | | +|---------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| CATEGORY: | Logical | +| APPLICABILITY: | Formatted processable content architecture class | +| STRUCTURE: | One of four parameters: <ul style="list-style-type: none"> <li>a) “width controlled” with sub-parameters: <ul style="list-style-type: none"> <li>“minimum width”</li> <li>“preferred width”</li> </ul> </li> <li>b) “height controlled” with sub-parameters: <ul style="list-style-type: none"> <li>“minimum height”</li> <li>“preferred height”</li> </ul> </li> <li>c) “area controlled” with sub-parameters: <ul style="list-style-type: none"> <li>“minimum width”</li> <li>“preferred width”</li> <li>“minimum height”</li> <li>“preferred height”</li> <li>“aspect ratio flag”</li> </ul> </li> <li>d) “automatic” with no sub-parameters</li> </ul> | +| PERMISSIBLE VALUES: | <ul style="list-style-type: none"> <li>“minimum width”: non-negative integer</li> <li>“preferred width”: non-negative integer</li> <li>“minimum height”: non-negative integer</li> <li>“preferred height”: non-negative integer</li> <li>“aspect ratio flag”: ‘fixed’, ‘variable’</li> <li>“automatic” with the value ‘null’</li> </ul> | + +DEFAULT VALUE: “automatic”. + +#### DEFINITION: + +This attribute specifies the intended dimensions of the basic layout object that is to contain the clipped pel array. + +The values of “minimum width” and “preferred width” specify, respectively, the lower limit and the upper limit of the allowed dimensions of the basic layout object in the direction of the pel path. The value of the ‘minimum width’ shall not to be greater than the value of the ‘preferred width’. + +The values of “minimum height” and “preferred height” specify, respectively, the lower limit and the upper limit of the dimensions of the basic layout object in the direction of the line progression. The value of the ‘minimum height’ shall not to be greater than the value of the ‘preferred height’. + +If either or both of the values of the preferred parameters are specified, the corresponding dimensions of the basic layout object are required to be as close to these values as possible. + +If only the range of allowed widths is specified [see case a)], this attribute specifies that the height shall be such that the aspect ratio of the clipped pel array is maintained. + +If only the range of allowed heights is specified [see case b)], this attribute specifies that the width shall be such that the aspect ratio of the clipped pel array is maintained. + +If both the ranges of allowed widths and heights are specified [see case c)] the value of ‘aspect ratio flag’ determines whether or not the aspect ratio of the clipped pel array shall be maintained during the determination of the dimensions of the basic layout object. + +If neither the range of allowed heights nor the range of allowed widths is specified (case d), this attribute specifies that the aspect ratio of the basic layout object shall be the same as the aspect ratio of the clipped pel array, and also that the dimension of the basic layout object in the direction of the pel path shall be equal to the dimension of the available area in that direction. + +All parameters specifying a width or height are specified in SMUs. + +### 8.3.2 Pel spacing + +| | | | +|---------------------|--------------------------------------------------|--------------------------| +| CATEGORY: | Logical | | +| APPLICABILITY: | Formatted processable content architecture class | | +| STRUCTURE: | Two parameters: | “length”<br>“pel spaces” | +| | or the value: | “null” | +| PERMISSIBLE VALUES: | “length”: | positive integer | +| | “pel spaces”: | positive integer | +| | “null” | | +| DEFAULT VALUE: | “length”: | 4 | +| | “pel spaces”: | 1 | + +#### DEFINITION: + +This attribute specifies the method for determining the distance between successive pels along a line. The attribute consists of either the value “null”, or the two parameters “length” (with integer value m) and “pel spaces” (with integer value n). + +If the attribute has a value of “null” the scalable dimension content layout method is followed. + +If the attribute consists of the two parameters, the ratio of the integers m and n (m/n) specifies the spacing in SMUs between two successive pels, and the fixed dimension content layout method is followed. + +NOTE – The scalable and fixed dimension content layout methods are described in clause 12.3 and 12.4. + +### 8.3.3 Spacing ratio + +| | | | +|---------------------|--------------------------------------------------|---------------------------------------------| +| CATEGORY: | Logical | | +| APPLICABILITY: | Formatted processable content architecture class | | +| STRUCTURE: | Two parameters: | “line spacing value”<br>“pel spacing value” | +| PERMISSIBLE VALUES: | “line spacing value”: | positive integer | +| | “pel spacing value”: | positive integer | + +| | | | +|----------------|-----------------------|---| +| DEFAULT VALUE: | “line spacing value”: | 1 | +| | “pel spacing value”: | 1 | + +#### **DEFINITION:** + +This attribute specifies the ratio between the line spacing and the pel spacing of the image represented by the content portion. This ratio is to be observed by the raster graphics content layout process (defined in clause 12) in determining the block size, and by the imaging process (defined in clause 13) to avoid image distortion. + +This attribute consists of two parameters, the “line spacing value” and the “pel spacing value”, the ratio of which is the ratio of the line spacing to the pel spacing. + +The attribute “spacing ratio” is only applicable when the value of the parameter “aspect ratio flag” in the attribute “image dimensions” is set to ‘fixed’. + +## 8.4 Content architecture class attributes + +### 8.4.1 Content architecture class + +The value of the attribute “content architecture class” of a basic component description that conforms to this Specification is an ASN.1 object identifier with one of the following values: + +- { 2 8 2 7 0 } for the formatted raster graphics content architecture class; +- { 2 8 2 7 2 } for the formatted raster graphics processable content architecture class. + +# 9 Definition of raster graphics content portion attributes + +According to ITU-T Rec. T.412 | ISO/IEC 8613-2, content portion attributes consist of four categories: + +- identification attributes; +- common coding attributes; +- coding attributes; +- content information attributes. + +The identification attributes are completely defined in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +The common coding attributes are described in ITU-T Rec. T.412 | ISO/IEC 8613-2; attribute values that are specific to raster graphics content architectures are specified in 9.1. + +Other coding attributes are defined in 9.2 and the format of the content information, i.e. the possible values of the attribute “content information”, is specified in 9.3. + +## 9.1 Common coding attributes + +### 9.1.1 Type of coding + +| | | +|---------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| CLASSIFICATION: | Defaultable | +| APPLICABILITY: | Formatted and formatted processable content architecture class | +| STRUCTURE: | ASN.1 object identifier or non-negative integer. | +| PERMISSIBLE VALUES: | <p>The permissible values for this attribute depend on the value of the attribute “bits per colour component” as follows:</p> <p>“bits per colour component” = 1:</p> <p>ASN.1 object identifier:</p> <ul style="list-style-type: none"> <li>{ 2 8 3 7 0 } for ‘Rec. T.6 encoding’,</li> <li>{ 2 8 3 7 1 } for ‘Rec. T.4 one-dimensional encoding’,</li> <li>{ 2 8 3 7 2 } for ‘Rec. T.4 two-dimensional encoding’,</li> <li>{ 2 8 3 7 3 } for ‘bitmap encoding’,</li> <li>{ 2 8 3 7 5 } for ‘tiled encoding’,</li> <li>{ 2 8 3 7 6 } for ‘Rec. T.6 encoding – MSB’,</li> <li>{ 2 8 3 7 7 } for ‘Rec. T.4 one-dimensional encoding – MSB’,</li> <li>{ 2 8 3 7 8 } for ‘Rec. T.4 two-dimensional encoding – MSB’,</li> </ul> | + +non-negative integer: + +1 for 'Rec. T.6 encoding'. + +"bits per colour component" > 1: + +ASN.1 object identifier: + +{ 2 8 3 7 9 } for 'direct value encoding', + +{ 2 8 3 7 10 } for 'octet run-length encoding', + +{ 2 8 3 7 11 } for 'packed index encoding'. + +NOTE – The use of 'Rec. T.6 encoding – MSB'; 'Rec. T.4 one-dimensional encoding – MSB'; and 'Rec. T.4 two-dimensional encoding – MSB' is applicable to ITU-T Rec. T.417 only. + +DEFAULT VALUE: + +The permissible values for this attribute depend on the value of the attribute "bits per colour component" as follows: + +"bits per colour component" = 1: +'Rec. T.6 encoding', + +"bits per colour component" > 1 +for further study + +DEFINITION: + +For the raster graphics content architectures, the possible values of this attribute are + +- 'Rec. T.6 encoding', for the two-dimensional encoding scheme defined in CCITT Rec. T.6; +- 'Rec. T.4 one-dimensional encoding', for the one-dimensional encoding scheme defined in ITU-T Rec. T.4; +- 'Rec. T.4 two-dimensional encoding', for the two-dimensional encoding scheme defined in ITU-T Rec. T.4; +- 'bitmap encoding'; +- 'Rec. T.6 encoding – MSB', for the two-dimensional encoding scheme defined in CCITT Rec. T.6 and where the first bit of the encoded T.6 data is allocated to the most significant bit of the first octet; +- 'Rec. T.4 one-dimensional encoding – MSB', for the one-dimensional encoding scheme defined in ITU-T Rec. T.4 and where the first bit of the encoded T.4 data is allocated to the most significant bit of the first octet; +- 'Rec. T.4 two-dimensional encoding – MSB', for the two-dimensional encoding scheme defined in ITU-T Rec. T.4 and where the first bit of the encoded T.4 data is allocated to the most significant bit of the first octet; +- 'tiled encoding' for the tiling scheme defined in this Specification, the bitmap encoding scheme, the two-dimensional coding scheme defined in CCITT Rec. T.6, or the one- or two-dimensional coding schemes defined in ITU-T Rec. T.4, the two-dimensional coding scheme defined in CCITT Rec. T.6 with MSB mapping, or the one- or two-dimensional coding schemes defined in ITU-T Rec. T.4 with MSB mapping; +- 'direct value encoding'; +- 'octet run-length encoding'; +- 'packed index encoding'. + +An explanation of these coding schemes is given in clause 11. + +The value 'tiled encoding' indicates that the tiles in the content portion description are each encoded per the value of the associated "tile types" attribute as defined in 9.2.8. + +The value of the attribute "type of coding" of a content portion description, that conforms to this Specification, is an ASN.1 object identifier or an integer. + +In coding, the relationship between the order of pels and the order of bits within an octet is such that the first pel in the order of bits is allocated to the most significant bit of an octet. + +The relationship between the order of pels, the order of encoded bits and the order of encoded octets is the same for tiled, as for untiled bitmap, Rec. T.4, Rec. T.4 – MSB, Rec. T.6 and Rec. T.6 – MSB encoding. + +## 9.2 Other coding attributes + +These attributes provide information required for encoding and decoding the content information, as well as other information that is intrinsic to the content portion and required by the content layout and imaging processes. + +### 9.2.1 Compression + +| | | +|---------------------|----------------------------------------------------------------| +| CLASSIFICATION: | Defaultable | +| APPLICABILITY: | Formatted and formatted processable content architecture class | +| PERMISSIBLE VALUES: | 'compressed', 'uncompressed' | +| DEFAULT VALUE: | 'compressed' | + +#### DEFINITION: + +This attribute indicates if the code extension technique for uncompressed mode is present in the content portion. This attribute can have one of two values: + +- 'compressed' indicates that the code extension technique for uncompressed mode is not used; +- 'uncompressed' indicates that the code extension technique for uncompressed mode may be used. + +NOTE – Basic mode (compressed) encoding is used initially for coding all such content portions. The occurrence of the code extension technique for uncompressed mode coding results in subsequent content being coded in uncompressed mode. + +This attribute is only applicable if the value of the attribute "type of coding" is 'Rec. T.6 encoding' or 'Rec. T.4 two-dimensional encoding'. + +### 9.2.2 Number of lines + +| | | +|---------------------|--------------------------------------------------| +| CLASSIFICATION: | Non-mandatory | +| APPLICABILITY: | Formatted processable content architecture class | +| PERMISSIBLE VALUES: | Positive integer | + +#### DEFINITION: + +This attribute specifies the number of lines of pels within a content portion. + +NOTE – This attribute takes effect during the content layout process. + +### 9.2.3 Number of pels per line + +| | | +|---------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| CLASSIFICATION: | Defaultable for components of the formatted content architecture class;<br><br>Mandatory for components of the formatted processable content architecture class | +| APPLICABILITY: | Formatted and formatted processable content architecture classes | +| PERMISSIBLE VALUES: | Non-negative integer | +| DEFAULT VALUE: | The default value for components of the formatted content architecture class depends upon the "pel transmission density" as specified in Table 4. No default value is specified for components of the formatted processable content architecture class | + +#### DEFINITION: + +This attribute specifies the number of pels in each line within a content portion. + +**Table 4 – Default value of the presentation attribute +“number of pels per line”** + +| Pel transmission density (BMU) | Default number of pels per line | +|--------------------------------|---------------------------------| +| 1 | 10 368 | +| 2 | 5 184 | +| 3 | 3 456 | +| 4 | 2 592 | +| 5 | 2 074 | +| 6 | 1 728 | + +### **9.2.4 Number of discarded pels** + +| | | +|---------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| CLASSIFICATION: | Defaultable | +| APPLICABILITY: | Formatted content architecture class | +| PERMISSIBLE VALUES: | non-negative integer | +| DEFAULT VALUE: | If the number of pels per line exceeds the number that can be placed within the available area by use of the reference imaging process specified in clause 13, then the default value is half the excess number of pels, otherwise it is 0. | + +#### DEFINITION: + +This attribute specifies the number of pels that are to be ignored at the beginning of each line within a content portion. The positioning of each line is started from the next pel in the line. + +### **9.2.5 Number of lines per tile** + +| | | +|--------------------|--------------------------------------------------| +| CLASSIFICATION: | Defaultable | +| APPLICABILITY: | Formatted processable content architecture class | +| PERMISSIBLE VALUE: | Positive integer | +| DEFAULT VALUE: | 512 | + +#### DEFINITION: + +This attribute specifies the tile dimension in units of line spaces in the direction of line progression. + +This attribute is only applicable if the value of the attribute “type of coding” is ‘tiled encoding’. + +### **9.2.6 Number of pels per tile line** + +| | | +|--------------------|--------------------------------------------------| +| CLASSIFICATION: | Defaultable | +| APPLICABILITY: | Formatted processable content architecture class | +| PERMISSIBLE VALUE: | Positive integer | +| DEFAULT VALUE: | 512 | + +#### DEFINITION: + +This attribute specifies the tile dimension in units of pel spaces in the pel path direction. + +This attribute is only applicable if the value of the attribute “type of coding” is ‘tiled encoding’. + +### **9.2.7 Tiling offset** + +| | | +|-----------------|-------------| +| CLASSIFICATION: | Defaultable | +|-----------------|-------------| + +| | | +|---------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| APPLICABILITY: | Formatted processable content<br>architecture class | +| STRUCTURE: | Coordinate pair: <span style="float: right;">X coordinate,<br/>Y coordinate</span> | +| PERMISSIBLE VALUES: | Coordinate pair<br>non-negative integer less than the value<br>of the attribute “number of pels per tile line”<br>non-negative integer less than the value<br>of the attribute “number of lines per tile” | +| DEFAULT VALUE: | (0,0) | + +#### **DEFINITION:** + +This attribute specifies the location of the pel array within the tile space by defining the offset of the first pel of the pel array from the first pel position of the first tile. The offset is specified in pel spaces in the direction of the pel path and line spaces in the direction of the line progression. + +All tiles cover a portion of the pel array. Portions of the tile space outside the pel array are artifacts of tiling and contain no information. + +This attribute is only applicable if the value of the attribute “type of coding” is ‘tiled encoding’. + +### **9.2.8 Tile types** + +| | | +|---------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| CLASSIFICATION: | Defaultable | +| APPLICABILITY: | Formatted processable content architecture class | +| PERMISSIBLE VALUES: | A sequence of one or more data elements with<br>one of the following values:<br>‘null background’, ‘null foreground’,<br>‘bitmap encoded’, ‘Rec. T.6 encoded’,<br>‘Rec. T.4 one-dimensional encoded’,<br>‘Rec. T.4 two-dimensional encoded’<br>‘Rec. T.6 encoded – MSB’, ‘Rec. T.4<br>one-dimensional encoded – MSB’,<br>‘Rec. T.4 two-dimensional encoded – MSB’<br>‘packed index encoding’<br>‘direct value encoding’<br>‘octet run-length encoding’ | +| DEFAULT VALUE: | All tiles are Rec. T.6 encoded | + +#### **DEFINITION:** + +This attribute indicates the type of coding of tiles in the content portion as a sequence of values. Each value specifies the type of coding of the corresponding tile (see Figure 6) in the content portion as follows: + +- ‘null background’, indicating that all pels in the tile are known to be background and the tile has no encoded content; +- ‘null foreground’, indicating that all pels in the tile are known as foreground and the tile has no encoded content; +- ‘Rec. T.6 encoded’, indicating that the pels in the tile are encoded as a Rec. T.6 octet string; +- ‘Rec. T.4 one-dimensional encoded’, indicating that the pels in the tile are encoded as a Rec. T.4 one-dimensional octet string; +- ‘Rec. T.4 two-dimensional encoded’, indicating that the pels in the tile are encoded as a Rec. T.4 two-dimensional octet string; +- ‘Rec. T.6 encoded’, indicating that the pels in the tile are encoded as a Rec. T.6 octet string; +- ‘Rec. T.4 one-dimensional encoded – MSB’, indicating that the pels in the tile are encoded as a Rec. T.4 one-dimensional octet string; +- ‘Rec. T.4 two-dimensional encoded – MSB’, indicating that the pels in the tile are encoded as a Rec. T.4 two-dimensional octet string; +- ‘bitmap encoded’, indicating that the pels in the tile are encoded as a bitmap octet string; + +- packed index encoding; +- direct value encoding; +- octet run-length encoding. + +The number of values is equal to the number of tiles. + +This attribute is only applicable if the value of the attribute “type of coding” is ‘tiled encoding’. + +### **9.2.9 Bits per colour component** + +| | | +|----------------------------|----------------------------------------------------------------| +| <b>CLASSIFICATION:</b> | Defaultable | +| <b>APPLICABILITY:</b> | Formatted and formatted processable content architecture class | +| <b>PERMISSIBLE VALUES:</b> | A positive integer, or a sequence of non-negative integers. | +| <b>DEFAULT VALUE:</b> | 1 | + +#### **DEFINITION:** + +This attribute defines the number of bits used to represent each colour component of the image. If the value is specified as a single integer, then that value applies to each component. Otherwise, each integer in the sequence specifies the number of bits in the corresponding component. + +Where a sequence of integers is specified, a zero value indicates that the corresponding colour component is not present in this image. At least one value in the sequence shall be non-zero. + +### **9.2.10 Interleaving format** + +| | | +|----------------------------|----------------------------------------------------------------| +| <b>CLASSIFICATION:</b> | Defaultable | +| <b>APPLICABILITY:</b> | Formatted and formatted processable content architecture class | +| <b>PERMISSIBLE VALUES:</b> | ‘pel’, ‘line’, ‘plane’ | +| <b>DEFAULT VALUE:</b> | ‘plane’ | + +#### **DEFINITION:** + +This attribute defines the method of interleaving of the components of the image. The values are defined as follows: + +- ‘pel’ for each pel, the colour component values are contiguous; +- ‘line’ for each colour component, all values corresponding to each pel on a line are contiguous; +- ‘plane’ for each colour component, all values corresponding to that component are contiguous. + +## **9.3 Content information attributes** + +For raster graphics content architectures, the value of the “content information” attribute is an octet string, or a sequence of octet strings in the case of tiled encoding, representing a pel array encoded according to the value of the attribute “type of coding”. + +## **9.4 Interactions with document architecture attributes** + +The layout directives “indivisibility” and “concatenation” are not taken into account during the layout of raster graphics content associated with a basic logical component. + +# **10 Formal definitions of raster graphics content architecture dependent data types** + +## **10.1 Introduction** + +This clause contains formal definitions in ASN.1 notation (defined in ISO/IEC 8824) of the data types corresponding to presentation and coding attributes that are applicable to raster graphics content architectures: + +Normative Annex C (to ISO/IEC 8613-7) contains the SGML representation of the attributes specific to raster graphics content architectures. + +These data types are: + +- the data type to represent raster graphics content architecture specific presentation attributes in basic layout components, presentation styles and default value lists; +- the data type to represent raster graphics content architecture specific coding attributes in content portions; +- the data type to represent non-basic values of raster graphics content architecture presentation attributes in the document profile; +- the data type to represent non-basic values of raster graphics content architecture coding attributes in the document profile; +- the data type to represent non-standard default values of raster graphics content architecture presentation and coding attributes in the document profile. + +## 10.2 Representation of presentation attributes + +The data type **Raster-Graphics-Attributes** contains a set of subordinate data types that specify the raster graphics presentation attributes. Some of these subordinate data types are elementary but others are structured and are themselves made up of subordinate data types. The format of these data types is given below. + +The subset of subordinate data types that may occur within a particular instance of the data type **Raster-Graphics-Attributes** depends upon the particular raster graphics content architecture level that is specified. + +**Raster-Gr-Presentation-Attributes { 2 8 1 7 2 }** + +**DEFINITIONS ::= BEGIN** + +**EXPORTS** + +**Raster-Graphics-Attributes, +Clipping, +Measure-Pair, +One-Of-Four-Angles, +One-Of-Two-Angles, +Pel-Transmission-Density, +Pel-Spacing, +Spacing-Ratio, +Coordinate-Pair;** + +``` + +Raster-Graphics-Attributes ::= SET { + pel-path [0] IMPLICIT One-Of-Four-Angles OPTIONAL, + line-progression [1] IMPLICIT One-Of-Two-Angles OPTIONAL, + pel-transmission-density [2] IMPLICIT Pel-Transmission-Density OPTIONAL, + initial-offset [3] IMPLICIT Measure-Pair OPTIONAL, + clipping [4] IMPLICIT Clipping OPTIONAL, + pel-spacing [5] Pel-Spacing OPTIONAL, + spacing-ratio [6] IMPLICIT Spacing-Ratio OPTIONAL, + image-dimensions [7] Image-Dimensions OPTIONAL } + +One-Of-Four-Angles ::= INTEGER { + d0 (0), d0 + d90 (1), d90 + d180 (2), d180 + d270 (3) d270 +} + +One-Of-Two-Angles ::= INTEGER { + d90 (1), d90 + d270 (3) d270 +} + +Pel-Transmission-Density ::= INTEGER { + p6 (1), 6 BMU + p5 (2), 5 BMU + p4 (3), 4 BMU + p3 (4), 3 BMU + p2 (5), 2 BMU + p1 (6) 1 BMU +} + +Measure-Pair ::= SEQUENCE { + +``` + +| | | +|------------------------|-----------------------------------------| +| horizontal | [0] IMPLICIT INTEGER, | +| vertical | [0] IMPLICIT INTEGER } | +| Clipping | ::= SEQUENCE { | +| first-coordinate-pair | [0] IMPLICIT Coordinate-Pair OPTIONAL, | +| second-coordinate-pair | [1] IMPLICIT Coordinate-Pair OPTIONAL } | +| Coordinate-Pair | ::= SEQUENCE { | +| x-coordinate | INTEGER, | +| y-coordinate, | INTEGER }, | +| Pel-Spacing | ::= CHOICE { | +| spacing | [0] IMPLICIT SEQUENCE { | +| length | INTEGER, | +| pel-spaces | INTEGER }, | +| null | [1] IMPLICIT NULL } | +| Spacing-Ratio | ::= SEQUENCE { | +| line-spacing-value | INTEGER, | +| pel-spacing-value | INTEGER }, | +| Image-Dimensions | ::= CHOICE { | +| width-controlled | [0] IMPLICIT SEQUENCE { | +| minimum-width | INTEGER, | +| preferred-width | INTEGER }, | +| height-controlled | [1] IMPLICIT SEQUENCE { | +| minimum-height | INTEGER, | +| preferred-height | INTEGER }, | +| area-controlled | [2] IMPLICIT SEQUENCE { | +| minimum-width | INTEGER, | +| preferred-width | INTEGER, | +| minimum-height | INTEGER, | +| preferred-height | INTEGER, | +| aspect-ratio-flag | INTEGER { | +| | fixed (0), | +| | variable (1) } }, | +| automatic | [3] IMPLICIT NULL } | +| END | | + +NOTE – The following types are also defined in other parts of the ITU-T Rec. T.410-Series | ISO/IEC 8613: ‘One-Of-Four-Angles’, ‘One-Of-Two-Angles’, ‘Measure-Pair’. + +## 10.3 Representation of coding attributes + +**Raster-Gr-Coding-Attributes { 2 8 1 7 3 }** + +**DEFINITIONS ::= BEGIN** + +**EXPORTS** + +Raster-Gr-Coding-Attributes, +Compression, +Tile-Type; + +**IMPORTS** + +Coordinate-Pair + +**FROM** + +Raster-Gr-Presentation-Attributes; + +| | | +|-----------------------------|-------------------------------------------| +| Raster-Gr-Coding-Attributes | ::= SET { | +| number-of-pels-per-line | [0] IMPLICIT INTEGER OPTIONAL, | +| number-of-lines | [1] IMPLICIT INTEGER OPTIONAL, | +| compression | [2] IMPLICIT Compression OPTIONAL, | +| number-of-discarded-pels | [3] IMPLICIT INTEGER OPTIONAL, | +| bits-per-colour-component | [4] Bits-Per-Colour-Component OPTIONAL, | +| interleaving-format | [5] IMPLICIT INTEGER | +| | { pel(0), line(1), plane(2) } OPTIONAL }, | + +| | | +|-----------------------------|------------------------------------------------| +| number-of-pels-er-tile-line | [6] IMPLICIT INTEGER OPTIONAL, | +| number-of-lines-er-title | [7] IMPLICIT INTEGER OPTIONAL, | +| tiling-offset | [8] IMPLICIT Coordinate-Pair OPTIONAL, | +| tile-types | [9] IMPLICIT SEQUENCE OF Tile-Type<br>OPTIONAL | + +Compression ::= INTEGER { uncompressed (0), compressed (1) } + +Tile-type ::= INTEGER { +null-background (0), +null-foreground (1), +T.6-encoded (2), +T.4-one-dimensional-encoded (3), +T.4-two-dimensional-encoded (4), +bitmap-encoded (5), +T.6-encoded–msb (6), +T.4-one-dimensional-encoded–msb (7), +T.4-two-dimensional-encoded–msb (8), +packed-index-encoding (9), +direct-value-encoding (10), +octet-run-length-encoding (11) } + +Bits-Per-Colour-Component ::= CHOICE { +component-list single-integer INTEGER, +component-list SEQUENCE OF INTEGER } + +END + +## 10.4 Representation of non-basic features and non-standard defaults + +Raster-Gr-Profile-Attributes { 2 8 1 7 4 } + +DEFINITIONS ::= BEGIN + +### EXPORTS + +Ra-Gr-Presentation-Feature, Ra-Gr-Coding-Attribute, +Raster-Gr-Content-Defaults; + +### IMPORTS + +One-Of-Four-Angles, +One-Of-Two-Angles, +Pel-Transmission-Density, +Measure-Pair, +Clipping, +Pel-Spacing, +Spacing-Ratio, +Image-Dimensions, +Coordinate-Pair, +Raster-Graphics-Attributes, +FROM Raster-Gr-Presentation-Attributes, +Compression, +Tile-Type, +FROM Raster-Gr-Coding-Attributes; + +Ra-Gr-Presentation-Feature ::= CHOICE { +Initial-offset [3] IMPLICIT Measure-Pair, +clipping [4] IMPLICIT Clipping, +pel-spacing [5] Pel-Spacing, +spacing-ratio [6] IMPLICIT Spacing-Ratio, +image-dimensions [7] Image-Dimensions, +pel-path [9] IMPLICIT One-Of-Four-Angles, +line-progression [10] IMPLICIT One-Of-Two-Angles, +pel-transmission-density [11] IMPLICIT Pel-Transmission-Density } +-- The tag values used above preserve compatibility +-- with Group 4 Class I facsimile data streams. + +Ra-Gr-Coding-Attributes := CHOICE { +compression [0] IMPLICIT Compression, +number of pels-per-tile-line [6] IMPLICIT INTEGER, +number of lines-per-tile [7] IMPLICIT INTEGER, +tiling-offset [8] IMPLICIT Coordinate-Pair, + +**tiling-types** [9] IMPLICIT Tile-Type } +-- The tag values used above preserve compatibility +-- with Group 4 Class I facsimile data streams. + +**Raster-Gr-Content-Defaults ::= SET {** +    **COMPONENTS OF Raster-Graphics-Attributes,** +    **compression [8] IMPLICIT Compression OPTIONAL,** +    **number-of-pels-per-tile-line [11] IMPLICIT INTEGER OPTIONAL,** +    **number-of-lines-per-tile [12] IMPLICIT INTEGER OPTIONAL,** +    **tiling-offset [13] IMPLICIT Coordinate-Pair** +        **OPTIONAL,** +    **tiling-type [14] IMPLICIT Tile-Type OPTIONAL }** +**END** + +# 11 Coding schemes + +A pel array may be represented within a text unit by means of one of the following encoding schemes: + +- CCITT Rec. T.6 encoding scheme; +- CCITT Rec. T.4 encoding schemes; +- CCITT Rec. T.6 encoding scheme – MSB; +- CCITT Rec. T.4 encoding schemes – MSB; +- bitmap encoding scheme; +- direct value encoding scheme; +- octet run-length encoding scheme; +- packed index encoding scheme. + +## 11.1 CCITT Rec. T.6 encoding scheme + +In this encoding scheme, a pel array is encoded according to CCITT Rec. T.6. The colours *black* and *white* referred to in that Recommendation should be interpreted as *foreground* and *background*, or *set* and *unset*, respectively. + +This part of the ITU-T Rec. T.417 | ISO/IEC 8613-7 allows the encoding scheme in CCITT Rec. T.6 to be extended to allow the encoding of run lengths greater than 2623. That is, this extension allows run lengths of greater than 2623 to be encoded by allowing the concatenation of two or more Make-up codewords. Thus, when horizontal mode encoding is used in the Rec. T.6 encoding algorithm, run lengths of 64 or greater are encoded first by one or more Make-up codewords representing the run lengths equal to or shorter than the run required. The minimum number of Make-up codewords shall be used. This is then followed by a single Terminating codeword (as defined in Rec. T.6) representing the difference between the required run lengths and the run lengths represented by the Make-up codeword or codewords. + +In addition, the encoded data belonging to each content portion shall be terminated by an EOFB (end-of-facsimile-block), the format of which is defined in CCITT Rec. T.6. + +The bits in the bit string defined by CCITT Rec. T.6, commencing with the first bit, and proceeding to the trailing bit, shall be placed in bits 1 to 8 of the first octet, followed by bits 1 to 8 of each octet in turn, followed by as many bits as are needed of the final octet, commencing with bit 1. For the purposes of this definition, the bits of an octet are numbered from 8 to 1, where bit 8 is the *most significant bit*, and bit 1 is the *least significant bit*. + +For Rec. T.6 – MSB encoding, the bits in the bit string defined by CCITT Rec. T.6, commencing with the trailing bit, and proceeding to the first bit, shall be placed in bits 1 to 8 of the first octet, followed by bits 1 to 8 of each octet in turn, followed by as many bits as are needed of the final octet, commencing with bit 1. For the purposes of this definition, the bits of an octet are numbered from 8 to 1, where bit 8 is the *most significant bit*, and bit 1 is the *least significant bit*. + +NOTE – The use of Rec. T.6 encoding – MSB is applicable to ITU-T Rec. T.417 only. + +## 11.2 CCITT Rec. T.4 encoding schemes + +In these encoding schemes, a pel array is encoded according the one or two-dimensional encoding schemes defined in CCITT Rec. T.4. The colours *black* and *white* referred to in that Recommendation should be interpreted as *foreground* and *background*, or *set* and *unset*, respectively. + +This part of the ITU-T Rec. T.417 | ISO/IEC 8613-7 allows the encoding scheme in CCITT Rec. T.4 to be extended to allow the encoding of run lengths greater than 2623. That is, this extension allows run lengths of greater than 2623 to be + +encoded by allowing the concatenation of two or more Make-up codewords. Thus, run lengths of 64 or greater are encoded first by one or more Make-up codewords representing the run lengths equal to or shorter than the run required. The minimum number of Make-up codewords shall be used. This is then followed by a single Terminating codeword representing the difference between the required run lengths and the run lengths represented by the Make-up codeword or codewords. + +When using the T.4 one- or two-dimensional encoding scheme, the use of EOL is required to indicate the end of the encoding of each line of pels. In addition, the encoded data belonging to each content portion shall be terminated by an RTC (return to control), the format of which is defined in CCITT Rec. T.4. If the total number of bits belonging to a content portion is not a multiple of eight (i.e. an integral number of octets), then the RTC must be followed by the minimum number of '0' bits such that the last bit aligns on an octet boundary. + +When using the two-dimensional encoding scheme, any number of fill bits and any value of K-parameter may be used without declaration in the coding attributes. + +The bits in the bit string defined by CCITT Rec. T.4, commencing with the first bit, and proceeding to the trailing bit, shall be placed in bits 1 to 8 of the first octet, followed by bits 1 to 8 of each octet in turn, followed by as many bits as are needed of the final octet, commencing with bit 1. For the purposes of this definition, the bits of an octet are numbered from 8 to 1, where bit 8 is the *most significant bit*, and bit 1 is the *least significant bit*. + +For Rec. T.4 – MSB encodings, the bits in the bit string defined by CCITT Rec. T.4, commencing with the trailing bit, and proceeding to the first bit, shall be placed in bits 1 to 8 of the first octet, followed by bits 1 to 8 of each octet in turn, followed by as many bits as are needed of the final octet, commencing with bit 1. For the purposes of this definition, the bits of an octet are numbered from 8 to 1, where bit 8 is the *most significant bit*, and bit 1 is the *least significant bit*. + +NOTE – The use of Rec. T.4 encodings – MSB is applicable to ITU-T Rec. T.417 only. + +## 11.3 Bitmap encoding scheme + +Each element in a pel array may have one of two distinct states. These are the set state, corresponding to foreground colour and the unset state, corresponding to background colour. For the purpose of representing such an array within a content portion, each pel may be represented by a single bit which has the value '0' or '1' depending on the state of that pel. If the pel has the unset state, the value of the bit is '0'; otherwise the value of the bit is '1'. + +In the bitmap encoding scheme, each row of the resulting array of bits is encoded, within a content portion, by a string of octets. If the number of bits in each row of the pel array is not a multiple of eight, then it is extended by the minimum number of '0' bits such that the last bit aligns on an octet boundary. + +When the content portion is decoded, the coding attribute “number of pels per line” is used to determine the number of bits in each line that are significant, the remaining bits being ignored. + +The relationship between the order of the pels and the order of the bits within an octet is such that the first pel in the order of bits is allocated to the most significant bit of an octet. + +NOTE – This encoding scheme is distinct from the uncompressed mode of the CCITT Recs. T.4 and T.6 encoding schemes. + +## 11.4 Tiled encoding scheme + +Tiled content information is coded as a sequence of octet strings representing a sequence of independently coded tiles. Each tile is encoded as one octet string which may be structured or unstructured. + +All the pels of a tile may be coded according to one of the following coding schemes: + +- CCITT Rec. T.6 encoding scheme; +- CCITT Rec. T.4 encoding schemes; +- CCITT Rec. T.6 encoding scheme – MSB; +- CCITT Rec. T.4 encoding schemes – MSB; +- bitmap encoding scheme; +- octet run-length encoding scheme; +- packed index encoding scheme. + +Alternatively the pels of a tile may be all background or all foreground, and not be coded. + +## 11.5 Direct value encoding scheme + +In this encoding the colour of each pel is directly specified in the content. The method of interleaving of the components is specified by the coding attribute “interleaving format”. The number of bits allocated for each component is specified by the coding attribute “bits per colour component”. The component values are integers. They may be scaled and offset by the colour scaling data. The scale, offset and interchange colour space are defined through the “colour spaces lists” attribute within the document profile. + +The component values are integers and are interpreted as the sub-components of the “colour specification” parameter of a direct colour expression (as defined in ITU-T Rec. T.412 | ISO/IEC 8613-2). The “colour space id” and “colour tolerance” parameters of the resulting direct colour expression are derived from the corresponding parameters of the attribute “content foreground colour” applying to the object with which the raster content is associated. For this purpose, the attribute value applying is required to be a direct colour expression. + +NOTE – The colour space id component will refer to the applying colour space description in the document profile which may contain colour scaling data that describe the scale and offset to be applied to the specified colour components in the raster content. Appropriate use of scaling and offsets may be required to map all colour values desired into the integer encoding space provided. + +For direct value encoding, the relationship between the order of the pels and the order of the bits within an octet is such that successive pels are allocated in the order of the most significant to least significant bit. + +## 11.6 Octet run-length encoding scheme + +In this encoding scheme, an image is encoded as a sequence of runs, each run consisting of a code octet followed by one or more data octets. Each line is encoded independently. The code octet is interpreted as a binary integer in the range 0 to 255, with the most significant bit of the integer aligned to the most significant bit of the octet, and is interpreted as follows: + +| | | +|----------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------| +| $0 ≤ ext{code} ≤ 128$ : | the next n octets, where n is given by the code, are used to directly encode pel color components as defined in the direct value encoding scheme; | +| $129 ≤ ext{code} ≤ 255$ : | the next octet is replicated (code – 128) times to obtain pel colour components encoded as defined in the direct value encoding scheme. | + +### NOTES + +1 The value 0 can be used as padding for alignment on multiple octet boundaries. + +2 To understand how this scheme works, suppose an image employs ‘line’ or ‘plane’ as the interleaving format. Further, for this explanation, suppose the value of the parameter “bits per colour component” is equal to 8 and that during the compression of an image a point is reached where N consecutive/adjacent pels have the same value (KK) for the colour component being processed. The encoded data stream would then contain a code octet, with (in this example) the value (N+128). The next octet would contain the common colour component data value (KK in this example). For N between 2 and 128, this saves N-2 octets in the compressed data stream. + +This encoding scheme is best applied in applications that use colour as an accent, for example, a blue border around a printed character text page. This encoding scheme is also most optimal when plane interleaving or line interleaving format is used. For applications that use images containing many colours and shades of colours, other encoding schemes are more appropriate. + +## 11.7 Packed index encoding scheme + +In this encoding the pel values are indices to the colour table specified in the attribute “content colour table” applying to the object with which the content is associated. This attribute is defined in ITU-T Rec. 412 | ISO 8613-2. Each index value is in the range from zero to $2^{**}( ext{bits-per-colour-component})-1$ and occupies “bits-per-colour-component-bits”. The pel values are packed sequentially independent of the octet boundaries. + +NOTE – A method of specifying colour tables in the content may be developed in a future version of this Specification. + +For packed index encoding, the relationship between the order of the pels and the order of the bits within an octet is such that successive pels are allocated in the order of the most significant to least significant bit. + +# 12 Content layout process + +This clause describes a content layout process for basic logical objects associated with raster graphics content architectures. + +Its purpose is to aid understanding of the semantics of the presentation attributes and coding attributes by describing the required results of such a process. However, it is not intended to specify any process that might be carried out in a particular implementation to achieve these results. + +## 12.1 Introduction + +### 12.1.1 Purpose + +The content layout process describes the process of laying out raster graphics content into an allocated area. This area is referred to as the available area and is determined by the document layout process defined in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +The purpose of the content layout process is to convert content associated with basic logical components into content associated with basic layout objects. + +The content layout process results in the creation of a basic layout object(s) into which the content is to be positioned. The dimensions of each basic layout object are returned to the document layout process, which determines the precise position of that basic layout object within the available area. + +One of two methods can be followed for laying out the content of a basic logical object. These methods are: + +- the fixed dimension content layout method; +- the scalable dimension content layout method. + +The choice of method depends on the particular presentation attributes associated with the basic logical object. + +### 12.1.2 Available area + +The content layout process is constrained by the available area. The maximum dimensions that a basic layout object can take are constrained by the dimensions of the available area. + +During the layout of the content associated with a basic logical object into a basic layout object, the following cases can occur: + +- the formatted processable content fits into the available area; +- the formatted processable content does not fit into the dimensions of the available area. In this case, a new available area is required. + +### 12.1.3 Presentation attributes + +The content layout process takes into account the presentation attributes applying to the basic logical object with which the content is associated. + +The presentation attributes applying to the content layout process may be specified in the generic layout structure and presentation styles. The values of these presentation attributes are determined according to the defaulting rules specified in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +### 12.1.4 Coding attributes + +The content layout process takes into account the coding attributes applying to the content portion. + +### 12.1.5 Raster graphics content architecture classes + +The content layout process is only specified for basic logical objects associated with the formatted processable raster graphics content architecture class. The content layout process does not modify the value of the attribute “content information”. + +### 12.1.6 Layout of the content + +For the raster graphics formatted processable content architecture class, one case of laying out the content into basic objects is possible: + +- *Single basic logical to single basic layout object* – The content of a single basic logical object may be laid out into a single basic layout object and is the only content associated with this basic layout object. + +## 12.2 Notation + +The abbreviations used in the description of the determination of block dimensions are defined in clause 4. + +## 12.3 The fixed dimension content layout method + +If the value of the attribute “pel spacing” is specified as other than ‘null’, the fixed dimension content layout method shall be followed. + +The fixed dimension content layout method creates a block with dimensions that satisfy the values of the following attributes: + +- the presentation attributes (defined in clause 8): + - “clipping”, + - “pel path”, + - “pel spacing”, + - “spacing ratio”, +- the coding attributes (defined in 9.2): + - “number of lines”, + - “number of pels per line”. + +The fixed dimension content layout process creates a block of the minimum dimensions that are required to accommodate the clipped pel array in accordance with the pel spacing and line spacing. Note that the pel spacing is explicitly specified by the attribute “pel spacing”, whereas the line spacing is determined from the pel spacing and the attribute “spacing ratio”. + +The horizontal and vertical block dimensions are determined, such that the reference areas of all the pels of the clipped pel array completely fill the basic layout object. The block dimensions depend on the pel path, pel spacing, spacing ratio, number of pels per line and number of lines as defined in Table 5. + +If one of the following conditions occurs: + +$$BDH > AAH \text{ or } BDV > AAV$$ + +then the block will not fit into the available area. It is then the responsibility of the document layout process to determine whether or not the content layout process is to be repeated for an alternative available area. + +**Table 5 – Dimensions of basic layout object** + +| Pel path | Horizontal block dimension<br>(BDH in SMUs) | Vertical block dimension<br>(BDV in SMUs) | +|--------------------------------------------------------------|---------------------------------------------|-------------------------------------------| +| d0, d180 | $NPC * PS$ | $NLC * PS * SR$ | +| d90, d270 | $NLC * PS * SR$ | $NPC * PS$ | +| NOTE – The notation used in this table is described in 12.2. | | | + +## 12.4 The scalable dimension content layout method + +If the value of the attribute “pel spacing” is specified as ‘null’, the scalable content layout method is followed. In this case the pel spacing will depend upon the value of the attribute “image dimensions” and the available area provided by the document layout process. + +The aim of the content layout process for scalable dimension content portions is to lay out the content, within the available area, in a basic layout object with the maximum dimensions possible, considering the image dimensions and the spacing ratio specified. + +The block dimensions are determined by + +- the presentation attributes (defined in clause 8): + - ‘clipping’, + - ‘pel path’, + - ‘image dimensions’, + +- ‘spacing ratio’, +- the coding attributes (defined in 9.2): + - “number of lines”, + - “number of pels per line”. + +The scalable dimension content layout method first determines the aspect ratio of the clipped pel array, from the values of the attributes “number of pels per line” and “number of lines”, taking into consideration the value of the attribute “spacing ratio”: + +$$\text{aspect ratio} = \frac{\text{NPC}}{\text{NLC} * \text{SR}} \quad (12-1)$$ + +Determination of the dimensions of the basic layout object depends on the value of the presentation attribute “image dimensions”. The four possible cases are illustrated in Figures 7 to 10, and are described below: + +- a) The attribute “image dimensions” specifies a value for the parameter “width controlled”. In this case the width of the basic layout object will be within the range specified by the originator. + +The determination of basic layout dimensions is constrained by the range of allowed widths given by the value of the parameter “width controlled”, the dimensions of the available area and the aspect ratio of the clipped array. + +The dimensions of the basic layout object shall be determined such that the basic layout object fits into the available area; the aspect ratio of the basic layout object is the same as that of the clipped pel array; and the width of the basic layout object has a value that is within the range of allowed widths. Also, the width of the basic layout object is determined such that the deviation from the value of the sub-parameter of “preferred width”, of the parameter “width controlled”, is as small as possible. + +- b) The presentation attribute “image dimensions” specifies a value for the parameter “height controlled”. In this case the height of the basic layout object will be within the range specified by the originator. + +The determination of basic layout object dimensions is constrained by the range of allowed heights given by the value of the parameter “height controlled”, the dimensions of the available area and the aspect ratio of the clipped pel array. + +The dimensions of the basic layout object shall be determined such that the basic layout object fits into the available area; the aspect ratio of the basic layout object is the same as that of the clipped pel array; and the height of the basic layout object has a value that is within the range of allowed heights. Also, the height of the basic layout object is determined such that the deviation from the value of the sub-parameter “preferred height”, of the parameter “height controlled”, is as small as possible. + +- c) The attribute “image dimensions” specifies a value for the parameter “area controlled”. In this case the dimensions of the basic layout object will be within the range specified by the originator. In particular, this can be used to ensure that the basic layout object will have a fixed size. + +The determination of basic layout object dimensions is constrained by the range of allowed heights and widths given by the value of the parameter “area controlled”, the dimensions of the available area and, depending upon the value of the “aspect ratio flag” of the parameter “area controlled”, by the aspect ratio of the clipped pel array. + +The dimensions of the basic layout object shall be determined such that the basic layout object fits into the available area; the width of the basic layout object has a value that is within the range of allowed widths; and the height of the basic layout object has a value that is within the range of allowed heights. If the value of the attribute “aspect ratio flag” is ‘fixed’ there is the further constraint to the basic layout object dimensions, that the aspect ratio of the basic layout object must be the same as that of the clipped pel array. Also both the width and height of the basic layout object shall be chosen such, that their deviations from their preferred values, of the parameter ‘area controlled’, are both as small as possible. + +- d) The attribute “image dimensions” specifies a value for the parameter “automatic”. In this case the dimensions of the basic layout object will be automatically adjusted to the page layout. + +The determination of basic layout object dimensions is constrained by the dimensions of the available area and the aspect ratio of the clipped pel array. + +The dimensions of the basic layout object have to be determined such that the basic layout object fits into the available area; the width of the basic layout object is given the same value as the dimension of the available area in the same direction; and the height of the basic layout object is determined such, that the aspect ratio of the basic layout object is the same as that of the clipped pel array. + +If the given constraints cannot be met, then the document layout process (defined in ITU-T Rec. T.412 | ISO/IEC 8613-2) is responsible for determining if the content layout method is to be repeated for an alternative available area. + +The dimensions of a basic layout object are restricted to integral multiples of 1 SMU. + +# **13 Content imaging process** + +This clause describes a content imaging process for basic layout objects associated with raster graphics content architectures. + +Its purpose is to aid understanding of the semantics of the shared and layout presentation attributes and coding attributes by describing the required results of such a process. However, it is not intended to specify any process that might be carried out in a particular implementation to achieve these results. + +The raster graphics content + +![Diagram of raster graphics content within a clipped pel array.](9612f08d343bcc2a11b174db64ba7b3a_img.jpg) + +A diagram showing a rectangular frame representing a raster graphics content area. Inside the frame, there is a stylized graphic consisting of a circle on the right and several horizontal lines extending to the left from the circle's center. An arrow points from the text 'Clipped pel array' to the right edge of the rectangular frame. + +Diagram of raster graphics content within a clipped pel array. + +Assumed page layout A + +![Assumed page layout A diagram.](08c7a76a7786bd08b99dd4cb41583ef4_img.jpg) + +A diagram of a page layout. At the top right is a small square box. Below it is a rectangular box labeled 'Title'. Below the 'Title' box is a larger rectangular box labeled 'Paragraph'. At the bottom is a large shaded rectangular area labeled 'Available area'. + +Assumed page layout A diagram. + +Alternate assumed page layout B + +![Alternate assumed page layout B diagram.](fb18a83d10ebdad8e3e5ea2e86b36136_img.jpg) + +A diagram of an alternate page layout. At the top right is a small square box. Below it is a rectangular box labeled 'Title'. Below the 'Title' box is a large rectangular box labeled 'Paragraph'. At the bottom is a shaded rectangular area labeled 'Available area'. + +Alternate assumed page layout B diagram. + +T0816840-94/d07 + +**Figure 7 – Diagrams used to illustrate the process of determining the basic layout object dimensions** + +Value of presentation attribute “image dimensions”: automatic + +- *Initial constraints* + +![Diagram showing initial constraints for layout. A clipped pel array icon and a box labeled 'Available area' (Page layout A) are shown. Arrows point from the icon to 'Aspect ratio of clipped pel array' and from the box to 'Width of available area' and 'Dimensions of available area'.](6629e8a87e7552e2454b7c3e9f6d73a0_img.jpg) + +(Page layout A) + +Available area + +Dimensions of available area + +Width of available area + +Aspect ratio of clipped pel array + +Diagram showing initial constraints for layout. A clipped pel array icon and a box labeled 'Available area' (Page layout A) are shown. Arrows point from the icon to 'Aspect ratio of clipped pel array' and from the box to 'Width of available area' and 'Dimensions of available area'. + +- *Allowable dimensions of basic layout object* + +![Diagram showing the allowable dimensions of a basic layout object. A dashed rectangle is shown with its width equal to the width of the available area and its height calculated as width divided by aspect ratio.](382a9c9e4816bd229191ab4591424dd8_img.jpg) + +Height = width of available area/aspect ratio + +Width = width of available area + +Diagram showing the allowable dimensions of a basic layout object. A dashed rectangle is shown with its width equal to the width of the available area and its height calculated as width divided by aspect ratio. + +- *Basic layout object dimensions determined* + +![Diagram showing the basic layout object dimensions determined. A shaded rectangle is shown within the available area, with labels for 'Dimensions of the basic layout object' and 'Dimensions of the available area'.](896e86ed12aff206d302c64f2e3091fa_img.jpg) + +Dimensions of the basic layout object + +Dimensions of the available area + +Diagram showing the basic layout object dimensions determined. A shaded rectangle is shown within the available area, with labels for 'Dimensions of the basic layout object' and 'Dimensions of the available area'. + +- *Basic objects laid out, positioned and imaged* + +![Diagram showing the final layout. A page frame contains several rectangular objects. The bottom-most object is a shaded rectangle labeled 'Available area for next base object'.](a8050baf48cc2c8e25d5ea2d1a67ef39_img.jpg) + +Available area for next base object + +Diagram showing the final layout. A page frame contains several rectangular objects. The bottom-most object is a shaded rectangle labeled 'Available area for next base object'. + +T0816860-94/d08 + +NOTE – In this example, the positioning of these basic layout objects assumes normal fill order, the attribute “block alignment” has value “centered” and a certain separation between two consecutive blocks. + +**Figure 8 – Layout process for the presentation attribute “image dimensions” when a value is specified for the parameter “automatic”** + +Value of "image dimensions": width controlled + +Value of "image dimensions": height controlled + +## - Initial constraints + +![Diagram showing initial constraints for a layout object. A central box contains a diagram of a layout object with a dashed line indicating its aspect ratio. To the left, horizontal arrows indicate 'Preferred width' and 'Minimum width'. To the right, vertical arrows indicate 'Minimum height' and 'Preferred height'. Below the central box, the text 'Aspect ratio of clipped pel array' is shown with arrows pointing to the width and height dimensions.](b58cedaf15ad4f0edee5621820865ccc_img.jpg) + +Diagram showing initial constraints for a layout object. A central box contains a diagram of a layout object with a dashed line indicating its aspect ratio. To the left, horizontal arrows indicate 'Preferred width' and 'Minimum width'. To the right, vertical arrows indicate 'Minimum height' and 'Preferred height'. Below the central box, the text 'Aspect ratio of clipped pel array' is shown with arrows pointing to the width and height dimensions. + +### - Allowable dimensions of basic layout object + +![Diagram showing allowable dimensions for two layout scenarios. On the left, for 'width controlled', a hatched rectangle shows 'Preferred width' and 'Minimum width' on the horizontal axis, and 'Minimum height = minimum width / aspect ratio' on the vertical axis. On the right, for 'height controlled', a hatched rectangle shows 'Preferred height' and 'Minimum height' on the vertical axis, and 'Minimum width = minimum height x aspect ratio' on the horizontal axis.](b6ad8b32179842fca5ad086cf22b03eb_img.jpg) + +Diagram showing allowable dimensions for two layout scenarios. On the left, for 'width controlled', a hatched rectangle shows 'Preferred width' and 'Minimum width' on the horizontal axis, and 'Minimum height = minimum width / aspect ratio' on the vertical axis. On the right, for 'height controlled', a hatched rectangle shows 'Preferred height' and 'Minimum height' on the vertical axis, and 'Minimum width = minimum height x aspect ratio' on the horizontal axis. + +NOTE – The hatched areas show a range of allowable dimensions of basic layout object. + +### - Basic layout object dimensions determined + +![Diagram showing the determination of basic layout object dimensions. It compares two page layouts: (Page layout A) and (Page layout B). In (Page layout A), the object is constrained by width, and a 'Deviation' is shown between the object's preferred width and the available area. In (Page layout B), the object is constrained by height, and a 'Deviation' is shown between the object's preferred height and the available area. Arrows indicate the 'Dimensions of available area' for both layouts.](24b1ac9eb58a2f22801620b9e2ea8bd3_img.jpg) + +Diagram showing the determination of basic layout object dimensions. It compares two page layouts: (Page layout A) and (Page layout B). In (Page layout A), the object is constrained by width, and a 'Deviation' is shown between the object's preferred width and the available area. In (Page layout B), the object is constrained by height, and a 'Deviation' is shown between the object's preferred height and the available area. Arrows indicate the 'Dimensions of available area' for both layouts. + +#### NOTES + +- 1 The basic layout object is indicated by the dashed-dotted boundary. +- 2 For specifying range of allowed image widths and layout A the preferred width cannot be satisfied due to the available width. +- 3 For specifying range of allowed image heights and layout B the major constraint is the height of the available area. + +## - Basic objects laid out, positioned and imaged + +NOTE – In this example, the positioning of these basic layout objects assumes normal fill order, the attribute "block alignment" has value "centered" and a certain separation between two consecutive blocks. + +![Diagram showing two examples of basic objects laid out, positioned, and imaged. Each example shows a vertical stack of three objects: a small rectangle at the top, a larger rectangle in the middle, and a complex object at the bottom. The bottom object is shown with a dashed-dotted boundary. Below the bottom object in the left example, a box indicates the 'Available area for next base object'. The right example is labeled 'T0816870-94/d09'.](0ec56da4ebeb9d5c0a8023653ddfed5c_img.jpg) + +Diagram showing two examples of basic objects laid out, positioned, and imaged. Each example shows a vertical stack of three objects: a small rectangle at the top, a larger rectangle in the middle, and a complex object at the bottom. The bottom object is shown with a dashed-dotted boundary. Below the bottom object in the left example, a box indicates the 'Available area for next base object'. The right example is labeled 'T0816870-94/d09'. + +Figure 9 – Layout process for the presentation attribute "image dimensions" when a value is specified for the parameter "width controlled" or "height controlled" + +Value of presentation attribute “image dimensions”: area controlled + +### - Initial constraints + +![Diagram showing initial constraints for image dimensions. It includes Preferred width, Minimum width, Minimum height, and Preferred height. A hatched rectangle represents the allowable range of dimensions.](329c96049bb432e9c2cbda4e224a0c9c_img.jpg) + +The diagram illustrates the initial constraints for image dimensions. It shows a rectangle divided into two horizontal sections. The top section is labeled 'Preferred width' and 'Minimum width' with horizontal arrows. The bottom section is labeled 'Minimum height' and 'Preferred height' with vertical arrows. A hatched area within the rectangle represents the range of allowable picture dimensions. + +Diagram showing initial constraints for image dimensions. It includes Preferred width, Minimum width, Minimum height, and Preferred height. A hatched rectangle represents the allowable range of dimensions. + +NOTE – The hatched area shows a range of allowable picture dimensions. + +### - Allowable picture dimensions + +The allowable picture dimensions are completely determined by the initial constraints. + +### - Basic layout dimensions determined (page layout A is used) + +![Diagram showing the determination of basic layout dimensions. It compares a 'fixed' aspect ratio flag with a 'variable' aspect ratio flag, showing how they affect the dimensions of the available area and the resulting deviation.](132cff7e872feb31f629703959beddd7_img.jpg) + +The diagram illustrates the determination of basic layout dimensions based on the aspect ratio flag. It shows two scenarios: 'fixed' and 'variable'. In the 'fixed' scenario, the aspect ratio of the region of interest is fixed, leading to a specific deviation. In the 'variable' scenario, the aspect ratio is variable, leading to a different deviation. The dimensions of the available area are shown for both cases. + +Diagram showing the determination of basic layout dimensions. It compares a 'fixed' aspect ratio flag with a 'variable' aspect ratio flag, showing how they affect the dimensions of the available area and the resulting deviation. + +NOTE – The basic layout object is indicated by the dashed-dotted boundary. + +### - Basic objects positioned, laid out and imaged + +NOTE – In this example, the positioning of these basic layout objects assumes normal fill order, the attribute “block alignment” has value “centered” and a certain separation between two consecutive blocks. + +![Diagram showing the final layout of basic objects. It displays a vertical stack of four rectangular blocks, with the third block containing a picture of a person sitting at a desk.](3621e1493d508bd789fec58ba8be9a40_img.jpg) + +The diagram shows the final layout of basic objects. It consists of a vertical stack of four rectangular blocks. The top block is a small rectangle. The second block is a larger rectangle. The third block contains a picture of a person sitting at a desk. The bottom block is a large rectangle. The objects are centered and separated by a certain distance. + +Diagram showing the final layout of basic objects. It displays a vertical stack of four rectangular blocks, with the third block containing a picture of a person sitting at a desk. + +T0816850-94/d10 + +Figure 10 – Layout process for the presentation attribute “picture dimensions” when a value is specified for the parameter “area controlled” + +## 13.1 Introduction + +The content imaging process is only concerned with the layout structures, the presentation styles and the content of basic layout components conforming to this Specification. + +The content imaging process is applicable to basic layout objects associated with the formatted and formatted processable raster graphics content architecture classes. + +## 13.2 Content imaging process for formatted form + +This clause describes how the image of the content is influenced by the various presentation and coding attributes applying to the formatted raster graphics content architecture class. + +The array of pels to be imaged consists only of those pels of the interchanged pel array which remain after the pels at the beginning of each line, specified by coding attribute “number of discarded pels”, have been subtracted. The first pel of this array is positioned at the initial point. + +The initial point is determined by the attribute “initial offset”. + +Only the pels which are positioned completely within the basic layout object are imaged. + +## 13.3 Content imaging process for formatted processable form + +This clause describes how the image of the content is influenced by the various presentation and coding attributes applying to the formatted processable raster graphics content architecture class. + +The clipped pel array is imaged in the basic layout object with the first pel at the initial point. + +The initial point is determined by the pel path, line progression and by the dimensions of the basic layout object, as defined in Table 2. + +The pel spacing is defined as the width of the basic layout object divided by the number of pels in a line of the clipped pel array. + +The line spacing is defined as the height of the basic layout object divided by the number of lines in the clipped pel array. + +# 14 Definition of raster graphics content architecture classes + +This clause defines the two classes of raster graphics content architectures described in clause 6: + +- formatted raster graphics content architecture class; +- formatted processable raster graphics content architecture class. + +Tables 6 and 7 specify the categories of presentation and content portion attributes that pertain to these content architecture classes. Content architecture levels for use in application profiles can be defined from these classes using the rules specified in ITU-T Rec. T.411 | ISO/IEC 8613-1. + +## 14.1 Summary of raster graphics presentation attributes + +Table 6 contains a list of raster graphics presentation attributes, and identifies, for each content architecture class, those which are defaultable and those which are not applicable. + +**Table 6 – Raster graphics presentation attributes** + +| Presentation attribute | Content architecture class | | +|------------------------------------------------------|----------------------------|----------------------------| +| | Formatted form | Formatted processable form | +| Pel path | D | D | +| Line progression | D | D | +| Pel transmission density | D | --- | +| Initial offset | D | --- | +| Pel spacing | --- | D | +| Spacing ratio | --- | D | +| Clipping | --- | D | +| Image dimensions | --- | D | +| --- Not applicable;<br>D Applicable and defaultable. | | | + +## 14.2 Summary of raster graphic content portion attributes + +Table 7 contains a list of raster graphics content portion attributes, and identifies, for each content architecture class, those which are mandatory, non-mandatory, defaultable and not applicable. + +**Table 7 – Raster graphics content portion attributes** + +| Presentation attribute | Content architecture class | | +|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------|----------------------------| +| | Formatted form | Formatted processable form | +| Number of pels per line | D | M | +| Type of coding | D | D | +| Compression | D | D <sup>a)</sup> | +| Number of discarded pels | D | --- | +| Number of lines | --- | NM | +| Number of pels per tile line | --- | D <sup>b)</sup> | +| Number of lines per tile | --- | D <sup>b)</sup> | +| Tiling offset | --- | D <sup>b)</sup> | +| Bits per colour component | NM | NM | +| Interleaving format | NM | NM | +| The notation used in this table is<br>--- Not applicable;<br>M Applicable and mandatory;<br>D Applicable and defaultable;<br>NM Applicable and non-mandatory.<br>a) This attribute is only applicable if the value of the attribute “type of coding” is ‘T.6 encoding or ‘T.4 two-dimensional encoding’.<br>b) This attribute is only applicable if the value of the attribute “type of coding” is ‘tiled encoding’. | | | + +# Annex A + +## Summary of raster graphics content architecture classes + +(This annex does not form an integral part of this Recommendation | International Standard) + +This annex summarizes the presentation attributes and content portion attributes that apply to each of the two content architecture classes (formatted and formatted processable) defined in clause 14, together with their permissible values and default values. + +The purpose of this annex is to facilitate the definition of raster graphic content architecture levels for use in document application profiles (see ITU-T Rec. T.411 | ISO/IEC 8613-1). + +## A.1 Formatted raster graphics content architecture class + +Content pertaining to the formatted raster graphics content architecture class may only be associated with basic layout components. + +### A.1.1 Presentation attributes + +See Table A.1 + +**Table A.1 – Formatted raster graphics content architecture class presentation attributes** + +| Attribute | Permissible values | Default value | +|--------------------------------------------------------------------------------------------------------------------|----------------------------|---------------| +| Pel path | d0, d90, d180, d270 | d0 | +| Line progression | d90, d270 | d270 | +| Pel transmission density | 6, 5, 4, 3, 2, 1 BMU | 6 BMU | +| Initial offset | (Any integer, any integer) | (Note) | +| NOTE – The default value of “initial offset” depends upon the pel path and line progression as defined in Table 2. | | | + +### A.1.2 Content portion attributes + +See Table A.2 + +**Table A.2 – Formatted processable raster graphics content architecture class content portion attributes** + +| Attribute | Permissible values | Default value | +|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------|---------------------------| +| Number of pels per line | Any positive integer | (Note 1) | +| Number of discarded pels | Any non-negative integer | (Note 2) | +| Type of coding | See clause 9.1.1. | Rec. T.6 encoding | +| Compression | ‘compressed’, ‘uncompressed’<br>as in Rec. T.6 | Compressed as in Rec. T.6 | +| NOTES<br>1 The default number of pels per line depends upon the pel transmission density as defined in Table 4.<br>2 If the number of pels per line exceeds the image line length, the default number of discarded pels is half the excess number of pels, otherwise it is zero. | | | + +## **A.2 Formatted processable raster graphics content architecture class** + +Content pertaining to the formatted processable raster graphics form content architecture class may be associated with basic layout or logical objects. + +### **A.2.1 Presentation attributes** + +See Table A.3. + +**Table A.3 – Formatted processable raster graphics content architecture class presentation attributes** + +| Attribute | Permissible values | Default value | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------| +| Pel path | d0, d90, d180, d270 | d90 | +| Line progression | d90, d270 | d270 | +| Pel spacing | (Any positive integer, any positive integer) SMU, 'null' | (4,1) SMU | +| Spacing ratio | (Any positive integer, any positive integer) | (1,1) | +| Clipping<br>First coordinate pair<br>Second coordinate pair | (Any non-negative integer, any non-negative integer)<br>(Any non-negative integer, any non-negative integer) | (Note 1) | +| Image dimensions<br>Width controlled<br>Minimum width<br>Preferred width<br>Height controlled<br>Minimum height<br>Preferred height<br>Area controlled<br>Minimum height<br>Preferred height<br>Minimum width<br>Preferred width<br>Aspect ratio flag<br>Automatic | (Note 2)<br><br>Any non-negative integer<br>Any non-negative integer<br><br>Any non-negative integer<br>Any non-negative integer<br><br>Any non-negative integer<br>Any non-negative integer<br>Any non-negative integer<br>Any non-negative integer<br>'Variable', 'fixed'<br>'null' | Automatic | +| NOTES<br>1 The default value of "clipping" is the first coordinate pair in the content portion (0,0) and the last coordinate pair (N-1, L-1), where N is number of pels per line and L is number of lines.<br>2 Minimum values must not be greater than preferred values. | | | + +### **A.2.2 Content portion attributes** + +See Table A.4. + +**Table A.4 – Formatted processable raster graphics content architecture class content portion attributes** + +| Attribute | Permissible values | Default value | +|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------| +| Number of pels per line | Any positive integer | None | +| Number of lines | Any positive integer | None | +| Type of coding | Bitmap encoding<br>Rec. T.4 encoding (one-dim.)<br>Rec. T.4 encoding (two-dim.)<br>Rec. T.6 encoding<br>Rec. T.4 encoding (two-dim.) – MSB<br>Rec. T.6 encoding – MSB<br>Tiled<br>Direct value<br>Octet run-length<br>Packed index | Rec. T.6 encoding | +| Compression | ‘compressed’<br>‘uncompressed’ as in Rec. T.6 | ‘compressed’ as in Rec. T.6<br>(Note) | +| Number of pels per tile line | Any positive integer | 512 | +| Number of lines per tile | Any positive integer | 512 | +| Tiling offset | (Any non-negative integer, less than<br>“number of pels per tile line”,<br>Any non-negative integer less than<br>“number of lines per tile”) | (0,0) | +| Tile types | Sequence of positive integers | Rec. T.6 encoded | +| Bits per colour component | A positive integer or a sequence of non-negative integers | 1 | +| Interleaving format | ‘pel’, ‘line’, ‘plane’ | ‘plane’ | +| NOTE – The attribute “compression” is only applicable if the value of the attribute “type of coding” is ‘Rec. T.6 encoding’, ‘Rec. T.4 two dimensional encoding’, ‘Rec. T.6 encoding – MSB’, ‘Rec. T.4 two dimensional encoding – MSB’, or ‘tiled encoding’. | | | + +# Annex B + +## Summary of ASN.1 object identifiers + +(This annex does not form an integral part of this Recommendation | International Standard) + +Values of ASN.1 object identifiers are assigned in various clauses of this Specification. These assignments are summarised in Table B.1. + +Table B.1 – Summary of ASN.1 object identifiers + +| ASN.1 object identifier value | Description | Subclause | +|-------------------------------|------------------------------------------------------------------|-----------| +| { 2 8 1 7 2 } | Raster-Gr-Presentation-Attributes | 10.2 | +| { 2 8 1 7 3 } | Raster-Gr-Coding-Attributes | 10.3 | +| { 2 8 1 7 4 } | Raster-Gr-Profile-Attributes | 10.4 | +| { 2 8 2 7 0 } | Formatted raster graphics content architecture class | 8.4.1 | +| { 2 8 2 7 2 } | Formatted processable raster graphics content architecture class | 8.4.1 | +| { 2 8 3 7 0 } | Identifies ‘Rec. T.6 encoding’ | 9.1.1 | +| { 2 8 3 7 1 } | Identifies ‘Rec. T.4 one-dimensional encoding’ | 9.1.1 | +| { 2 8 3 7 2 } | Identifies ‘Rec. T.4 two-dimensional encoding’ | 9.1.1 | +| { 2 8 3 7 3 } | Identifies ‘bitmap encoding’ | 9.1.1 | +| { 2 8 3 7 5 } | Identifies ‘tiled encoding’ | 9.1.1 | +| { 2 8 3 7 6 } | Identifies ‘Rec. T.6 encoding – MSB’ | 9.1.1 | +| { 2 8 3 7 7 } | Identifies ‘Rec. T.4 one-dimensional encoding – MSB’ | 9.1.1 | +| { 2 8 3 7 8 } | Identifies ‘Rec. T.4 two-dimensional encoding – MSB’ | 9.1.1 | +| { 2 8 3 7 9 } | Identifies ‘direct value encoding’ | 9.1.1 | +| { 2 8 3 7 10 } | Identifies ‘octet run-length encoding’ | 9.1.1 | +| { 2 8 3 7 11 } | Identifies ‘packed index encoding’ | 9.1.1 | + +# Annex C + +## SGML representation of raster graphics content-specific attributes for ODL + +(This annex forms an integral part of ISO/IEC 8613-7 only) + +NOTE – To maintain correspondence in clause numbering within the body of this Specification, this portion describing the use of Open Document Language (ODL) is specified in a normative annex rather than in the body of this Specification. + +## C.1 Introduction + +This annex specifies a standardised SGML representation of attributes related to raster graphics content architectures, for use with the Open Document Language (ODL) defined in ISO/IEC 8613-5. ODL is an SGML application conforming to ISO 8879. + +The definitions of ISO 8879 apply to this annex. + +## C.2 Names and public identifiers + +The following notation declarations include the public identifiers of the data content notations for the content architecture classes defined in this Specification. The ODL content architecture class names follow the prefix 'ODA' in the notation names. + +``` +<!NOTATION ODArfp PUBLIC "ISO/IEC 8613-7:1994//NOTATION +``` + +``` +Raster graphics formatted content architecture//EN"> +``` + +``` +<!NOTATION ODArfp PUBLIC "ISO/IEC 8613-7:1994//NOTATION +``` + +``` +Raster graphics formatted processable content architecture//EN"> +``` + +## C.3 Representation of attribute values + +Attribute values are represented in a clear text encoding, using the rules defined in this annex. + +NOTE 1 – The content portions themselves are encoded according to the body of this Specification. + +The representations of the ODA attributes are presented in the form of SGML public text. In this form they can be referenced from a document, rather than be included within it. + +The semantics of the attribute values are specified in the body of this Specification. The representation of attribute values is as specified in the body of this Specification, except where a different representation is specified in the public text or elsewhere in this annex. + +The default values specified in the public text are those defined in the body of this Specification. If a different default value is wanted for an element (such as a non-standard default value specified in the document profile or in an object class description), the public text should not be referenced; instead, the definitions should be duplicated with the required changes made in the default values. + +Attribute values are sequences of one or more parameters, separated by SGML separator characters. An omitted parameter is represented by the keyword: 00 + +A parameter is one of a number of primitive types: string, keyword, or integer. String parameters are delimited, and may contain separator characters. Other parameters are not delimited, and may not contain separator characters. + +NOTE 2 – Most attribute values consist of a single parameter. + +### C.3.1 Constructed parameters + +No constructed parameters are defined in this Specification. + +### C.3.2 String parameters + +A string parameter could contain characters not permitted in an SGML name token, and is therefore delimited by SGML LIT or LITA delimiters. + +### C.3.3 Keyword parameters + +Possible keyword values are defined by the body of this part for some parameters, and by this annex for others. + +Lower-case letters in keyword parameters are treated as though they were upper-case. + +For certain parameters whose permissible values constitute a set of keywords, fixed numeric values, or both keywords and fixed numeric values, the value is chosen by choosing from a set of substitute keywords. These parameters are documented in comments in the public text, in the form: + +parameter name: keyword .. + +with the keywords appearing in the same order as the permissible values that they represent appear within the body of this Specification. For attributes that have only one parameter, the attribute name is the parameter name. + +NOTE – For example: + +-- line progression: d90 d270 - + +means that a value of 'd90' represents 'd90' and a value of 'd270' represents 'd270'. + +### C.3.4 Integer parameters + +An integer is represented by a sequence of digits. If preceded by a hyphen, it represents a negative integer; otherwise, a positive integer. + +## C.4 Presentation attributes + +### C.4.1 Shared presentation attributes (format attribute-directives) + +<!-- © International Organization for Standardization 1994 + +Permission to copy in any form is granted for use with conforming SGML systems and applications as defined in ISO 8879, provided this notice is included in all copies. + +⇒ + +<!-- Public text entity. Typical invocation: + +<!ENTITY % r-p-ad PUBLIC "ISO/IEC 8613-7:1994//TEXT +Raster Presentation Format Attribute-Directives//EN"> + +<!ATTLIST (rf|rfp) %r-p-a; \%r-p-ad; > + +⇒ + +| | | | | +|----------|---------|----------|-----------------------------------| +| relip | NUMBERS | #IMPLIED | -- clipping -- | +| rlinepro | NUMBER | d270 | -- line progression: d90 d270 -- | +| rpelath | NUMBER | d0 | -- pel path: d0 d90 d180 d270 --, | + +### C.4.2 Layout presentation attributes (formal attributes) + +<!-- © International Organization for Standardization 1994 + +Permission to copy in any form is granted for use with conforming SGML systems and applications as defined in ISO 8879, provided this notice is included in all copies. + +⇒ + +<!-- Public text entity. Typical invocation: + +<!ENTITY \%r-p-a PUBLIC "ISO/IEC 8613-7:1994//TEXT +Raster Presentation Format Attributes//EN"> + +<!ATTLIST (rf|rfp) \%r-p-a; \%r-p-ad; > + +⇒ + +| | | | | +|----------|----------|----------|--------------------------------| +| rinitoff | NMTOKENS | #IMPLIED | -- initial offset -- | +| rpelens | NUMBER | 6 | -- pel transmission density -- | + +### C.4.3 Logical presentation attributes (format directives) + +<!-- © International Organization for Standardization 1994. + +Permission to copy in any form is granted for use with conforming SGML systems and applications as defined in ISO 8879, provided this notice is included in all copies. + +⇒ + +<!-- Public text entity. Typical invocation: + +<!ENTITY \%r-p-d PUBLIC "ISO/IEC 8613-7:1994//TEXT +Raster Presentation Format Directives//EN"> + +<!ATTLIST rfp \%r-p-d; > + +⇒ + +| | | | | +|---------|----------|-----------|------------------------------------------------| +| rdim | NAME | auto | -- image dimensions: width height area auto -- | +| rdimsub | NMTOKENS | ,#IMPLIED | -- image dimensions sub-parameters -- | + +``` + +rpelsp NUMBERS "4 1" -- pel spacing: '0' means 'null' -- +rspacing NUMBERS "1 1" -- spacing ratio -- + +``` + +## C.5 Coding attributes + +<! -- © International Organization for Standardization 1994 + +Permission to copy in any form is granted for use with conforming SGML systems and applications as defined in ISO 8879, provided this notice is included in all copies. + +⇒ + +<! -- Public text entity. Typical invocation: + +``` + +<!ENTITY % r-p-c PUBLIC "ISO/IEC 8613-7:1994//TEXT + Raster Coding Attributes//EN"> + +``` + +<!ATTLIST NOTATION (ODArf|ODArfp) %r-p-c; > + +``` + +⇒ codetype NAME T.6 -- type of coding: T.6 T.4-1 T.4-2 BITMAP + DIRECT RUNLEN INDEX -- + + rcomp NAME compress -- compression: COMPRESS UNCOMP -- + + rintlv NAME plane -- interleaving format: PEL LINE PLANE -- + + rlines NUMBER #IMPLIED -- number of lines -- + + rppl NUMBER #REQUIRED -- number of pels per line -- + + rdiscard NUMBER #IMPLIED -- number of discarded pels -- + + bitscomp NUMBERS 1 -- bits per colour component -- + +``` + +# Index + +NOTE – The number(s) associated with the index entry indicates the page(s) where the index entry can be found. + +- | | | +|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <ul style="list-style-type: none"> <li>alignment, 10, 14, 15, 16, 17, 27, 30, 31, 41</li> <li>angles of rotation, 6</li> <li>area controlled, 31</li> <li>aspect ratio, 10, 14, 15, 30, 31, 39</li> <li>aspect ratio flag, 14</li> <li>automatic, 14, 23, 39</li> <li>background, 25, 26</li> <li>background colour, 4, 26</li> <li>basic component, 3, 4, 10, 15</li> <li>basic components, 4</li> <li>basic layout components, 21, 36, 38</li> <li>basic layout object, 1, 3, 5, 6, 9, 10, 12, 14, 28, 29, 30, 31, 36</li> <li>basic logical object, 28, 29</li> <li>basic measurement unit, 6</li> <li>binary mode, 4</li> <li>bitmap encoding, 16, 17, 25, 26</li> <li>bits per colour component, 16, 20, 27</li> <li>black, 25</li> <li>BMU, 6, 13, 18, 22, 38</li> <li>clipped array, 3, 30</li> <li>clipped pel array, 6, 7, 10, 14, 29, 30, 31, 36</li> <li>clipping, 7, 11, 22, 29, 30, 37, 39, 43</li> <li>colour, 4, 5, 21, 23, 24, 27, 44</li> <li>colour component, 5</li> <li>colour components, 5</li> <li>colour mode, 4</li> <li>colour space, 4, 5</li> <li>colour spaces lists, 27</li> <li>colour specification, 5</li> <li>colour table, 27</li> <li>colour tolerance, 4</li> <li>content background colour, 4</li> <li>content colour table, 27</li> </ul> | <ul style="list-style-type: none"> <li>content foreground colour, 4, 27</li> <li>content information, 4</li> <li>content layout process, 28</li> <li>content portion attributes, 1, 4, 16, 36, 37, 38, 40</li> <li>coordinate pair, 6</li> <li>coordinate system, 6</li> <li>dimensionless coordinate system, 6</li> <li>direct colour expression, 27</li> <li>direct mode, 5</li> <li>direct value encoding scheme, 25</li> <li>discarded pels, 7, 19, 36, 37, 38, 44</li> <li>discarding of pels, 6</li> <li>end-of-facsimile-block, 2, 25</li> <li>EOFB, 25</li> <li>EOL, 26</li> <li>fixed dimension content layout method, 28</li> <li>fixed dimension layout method, 3</li> <li>foreground, 25, 26</li> <li>foreground colour, 26</li> <li>formatted form, 1</li> <li>formatted form content, 3, 10</li> <li>formatted processable content, 3</li> <li>formatted processable form, 1</li> <li>formatted processable raster graphics content, 3</li> <li>formatted processable raster graphics content architecture class, 3</li> <li>formatted raster graphics content, 3</li> <li>formatted raster graphics content architecture class, 3</li> <li>height controlled, 30</li> <li>horizontal block dimension, 2</li> <li>horizontal dimension of available area, 2</li> <li>image dimension, 30</li> <li>image dimensions, 11, 30</li> <li>imaging process, 10, 11, 15, 19, 31, 36</li> </ul> | +|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| + +- indexed mode, 5 +- line spacing, 10 +- initial offset, 11, 36 +- initial point, 9, 10 +- interchange colour space, 27 +- interleaving format, 27 +- layout presentation attributes, 11, 43 +- line progression, 7, 9, 11 +- line spacing, 9, 10 +- lines of pel, 10 +- logical presentation attributes, 10, 14 +- Make-up codeword, 25, 26 +- most significant bit, 2 +- number of discarded pels, 19, 36 +- number of lines, 29 +- number of pels per line, 26, 29, 30 +- octet run-length encoding, 26 +- octet run-length encoding scheme, 25 +- ordered sequence, 4 +- packed index encoding, 26, 27 +- packed index encoding scheme, 25 +- page coordinate system, 6 +- pel array, 3, 4 +- pel path, 6, 7, 9, 10, 11, 12, 14, 19, 29, 30, 36, 37, 38, 39, 43 +- pel spacing, 3, 6, 9, 10, 11, 13, 15, 29, 30, 36, 37, 39, 44 +- Pel transmission density, 13, 18, 38, 43 +- pel transmission density, 11, 37 +- pel values, 27 +- picture elements, 4 +- positioning of pels, 3 +- positioning pels, 3, 5, 6, 9 +- positioning rules, 5, 10 +- preferred height, 30 +- presentation attributes, 4, 10, 12, 21, 22, 28, 29, 38, 39, 43 +- processable form, 1 +- raster graphics content architecture presentation attributes, 21 +- raster graphics presentation attributes, 10, 36 +- raster-graphics-presentation attributes, 37 +- rectangular coordinate system, 6 +- reference area, 6 +- reference point, 6, 9, 12 +- return to control, 26 +- return-to-control, 3 +- RTC, 26 +- scalable dimension content layout method, 28 +- scalable dimension layout method, 3 +- scaled measurements units, 6 +- set, 4, 10, 15, 22, 23, 25, 26, 43 +- shared presentation attributes, 11, 43 +- SMU, 6, 13, 31, 39 +- spacing ratio, 3, 10, 11, 29, 30 +- states, 4, 26 +- Terminating codeword, 25, 26 +- tiles, 7 +- tiling offset, 7 +- unit scaling, 6 +- unset, 4, 25, 26 +- vertical block dimension, 2 +- vertical dimension of available area, 2 +- white, 25 \ No newline at end of file diff --git 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b/marked/T/T-REC-T.418-199303-I_PDF-E/raw.md @@ -0,0 +1,1972 @@ + + +![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU and a lightning bolt symbol. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## T.418 + +(03/93) + +**TELEMATIC SERVICES** + +**TERMINAL EQUIPMENTS AND PROTOCOLS +FOR TELEMATIC SERVICES** + +--- + +**INFORMATION TECHNOLOGY – OPEN +DOCUMENT ARCHITECTURE (ODA) AND +INTERCHANGE FORMAT: +GEOMETRIC GRAPHICS CONTENT +ARCHITECTURE** + +**ITU-T Recommendation T.418** + +--- + +# Foreword + +ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. Some 179 member countries, 84 telecom operating entities, 145 scientific and industrial organizations and 38 international organizations participate in ITU-T which is the body which sets world telecommunications standards (Recommendations). + +The approval of Recommendations by the Members of ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, 1993). In addition, the World Telecommunication Standardization Conference (WTSC), which meets every four years, approves Recommendations submitted to it and establishes the study programme for the following period. + +In some areas of information technology, which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. The text of ITU-T Recommendation T.418 was approved by the WTSC (Helsinki, March 1-12, 1993). The identical text is also published as ISO/IEC International Standard 8613-8. + +# --- NOTES + +1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector. + +In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms "CCITT, CCIR or IFRB" or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. + +2 In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# CONTENTS + +| | <i>Page</i> | +|---------------------------------------------------------------------------------------|-------------| +| INTRODUCTION | iii | +| 1 Scope | 1 | +| 2 Normative references | 2 | +| 2.1 Identical Recommendations International Standards | 2 | +| 2.2 Paired Recommendations International Standards equivalent in technical content | 2 | +| 2.3 Additional references | 2 | +| 3 Definitions | 2 | +| 4 Abbreviations | 2 | +| 5 Conventions | 3 | +| 5.1 CGM | 3 | +| 5.2 Individual CGM elements | 3 | +| 5.3 CGM concepts | 3 | +| 5.4 CGM defaults | 3 | +| 5.5 Parameter names | 3 | +| 5.6 Width and height | 3 | +| 6 General principles | 4 | +| 6.1 Content architecture classes | 4 | +| 6.2 Content | 4 | +| 6.3 Presentation attributes | 4 | +| 6.4 Coding of content information | 4 | +| 6.5 Layout and imaging of the content | 5 | +| 6.6 Colour spaces applicable to geometric graphics content architecture | 5 | +| 7 Positioning | 5 | +| 7.1 Introduction | 5 | +| 7.2 Measurement units and directions | 5 | +| 7.3 The relationship between the region of interest and the basic layout object | 6 | +| 8 Definition of geometric graphics presentation attributes | 8 | +| 8.1 Shared presentation attributes | 8 | +| 8.1.1 Attributes specifying CGM defaults | 8 | +| 8.1.2 Region of interest specification | 18 | +| 8.1.3 Picture orientation | 18 | +| 8.2 Logical presentation attributes | 19 | +| 8.2.1 Picture dimensions | 19 | +| 8.3 Content architecture class attributes | 20 | +| 8.3.1 Content architecture class | 20 | +| 8.4 Interaction with document architecture attributes | 20 | +| 9 Geometric graphics content portion attributes | 20 | +| 9.1 Common coding attributes | 20 | +| 9.2 Content information | 20 | +| 9.3 Other coding attributes | 20 | +| 10 Formal definitions of geometric graphics content architecture dependent data types | 21 | +| 10.1 Introduction | 21 | +| 10.2 Representation of geometric graphics presentation attributes | 21 | +| 10.3 Representation of coding attributes | 25 | +| 10.4 Representation of non-basic features and non-standard defaults | 25 | + +| | <i>Page</i> | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 11 Content layout process ..... | 26 | +| 11.1 Introduction..... | 26 | +| 11.1.1 Purpose ..... | 26 | +| 11.1.2 Available area ..... | 26 | +| 11.1.3 Presentation attributes..... | 26 | +| 11.1.4 Geometric graphics content architecture classes..... | 26 | +| 11.1.5 Layout of the content ..... | 26 | +| 11.2 Content layout process for formatted processable content architecture class ..... | 27 | +| 12 Content imaging process ..... | 32 | +| 12.1 Introduction..... | 32 | +| 12.2 Content imaging process for formatted processable form content architecture class ..... | 32 | +| 12.2.1 Initialization of the imaging process ..... | 32 | +| 12.2.2 Imaging ..... | 32 | +| 13 Definition of geometric graphics content architecture classes ..... | 33 | +| Annex A – Summary of ASN.1 object identifiers..... | 34 | +| Annex B – Basic differences between character primitives in the geometric graphics and the content of a basic component structured according to the character content architectures defined in ITU-T Rec. T.416 ISO/IEC 8613-6..... | 35 | +| Annex C – SGML representation of geometric graphics content-specific attributes for ODL ..... | 36 | +| C.1 Introduction..... | 36 | +| C.2 Names and public identifiers..... | 36 | +| C.3 Representation of attribute values..... | 36 | +| C.3.1 Constructed parameters..... | 36 | +| C.3.2 String parameters ..... | 37 | +| C.3.3 Keyword parameters ..... | 37 | +| C.3.4 Integer parameters..... | 37 | +| C.3.5 Real parameters..... | 38 | +| C.3.6 Aspect source flags (ASF) parameters..... | 38 | +| C.4 Presentation attributes ..... | 38 | +| C.4.1 Shared presentation attributes (format attribute-directives)..... | 38 | +| C.4.2 Logical presentation attributes (format directives) ..... | 39 | +| C.5 Coding attributes..... | 39 | +| Index ..... | 41 | + +# INTRODUCTION + +This ITU-T Recommendation | International Standard was prepared as a joint publication by ITU-T Study Group 8 and ISO/IEC Joint Technical Committee 1. + +At present, the ITU-T Recommendation T.410-Series | ISO/IEC 8613 consists of: + +- Introduction and general principles; +- Document structures; +- Document profile; +- Open document interchange formats; +- Character content architectures; +- Raster graphics content architectures; +- Geometric graphics content architectures; +- Formal Specification of the Open Document Architecture (FODA). + +(The formal specification is applicable to ISO/IEC 8613 only). + +Further Recommendations | International Standards may be added to this series of ITU-T Recommendations | International Standards. + +Development of this series of ITU-T Recommendations | International Standards was originally in parallel with the ECMA-101 standard: Open Document Architecture. + +This series of ITU-T Recommendations | International Standards is a new edition of the CCITT T.410-Series of Recommendations (1988) and ISO 8613 (1989). + +Significant technical changes are the inclusion of the following amendments as agreed by ITU-T and ISO/IEC: + +- Alternative representation; +- Annex on use of MHS/MOTIS; +- Colour; +- Conformance Testing Annex; +- Document Application Profile, Proforma and Notation; +- Security; +- Streams; +- Styles; +- Tiled raster graphics. + +In addition, a number of technical corrigenda have been applied to this ITU-T Recommendation | International Standard. + +This ITU-T Recommendation | International Standard contains three annexes: + +- Annex A summarises the ASN.1 object identifiers (non-integral); +- Annex B describes the differences between character primitives in the geometric graphics and the content structured according to the character content architectures defined in ITU-T Rec. T.416 | ISO/IEC 8613-6 (non-integral); +- Annex C describes the SGML representation of geometric graphics content-specific attributes for ODL (integral). + +(The use of Annex C is applicable to ISO/IEC 8613 only.) + + + +## INTERNATIONAL STANDARD + +## ITU-T RECOMMENDATION + +## **INFORMATION TECHNOLOGY – OPEN DOCUMENT ARCHITECTURE (ODA) AND INTERCHANGE FORMAT: GEOMETRIC GRAPHICS CONTENT ARCHITECTURES** + +# **1 Scope** + +The purpose of the ITU-T Rec. T.410-Series | ISO/IEC 8613 is to facilitate the interchange of documents. + +In the context of these Recommendations | International Standards, documents are to be items such as memoranda, letters, invoices, forms and reports, which may include pictures and tabular material. The content elements used within the documents may include graphic characters, raster graphics elements and geometric graphics elements, all potentially within one document. + +NOTE – These Recommendations | International Standards are designed to allow for extensions, including hypermedia features, spreadsheets and additional types of content such as audio and video. + +In addition to the content types defined in these Recommendations | International Standards, ODA also provides for arbitrary content types to be included in documents. + +These Recommendations | International Standards apply to the interchange of documents by means of data communication or the exchange of storage media. + +These Recommendations | International Standards provide for the interchange of documents for either or both of the following purposes: + +- to allow presentation as intended by the originator; +- to allow processing such as editing and reformatting. + +The composition of a document in interchange can take several forms: + +- formatted form, allowing presentation of the document; +- processable form, allowing processing of the document; +- formatted processable form, allowing both presentation and processing. + +These Recommendations | International Standards also provide for the interchange of ODA information structures used for the processing of interchanged documents. + +This ITU-T Recommendation | International Standard: + +- defines a geometric graphics content architecture that can be used in conjunction with the document architecture defined in ITU-T Rec. T.412 | ISO/IEC 8613-2; +- defines an interface which allows the use of content structured according to ISO/IEC 8632 within documents structured according to ITU-T Rec. T.412 | ISO/IEC 8613-2; +- defines those aspects of positioning and imaging applicable to the presentation of this geometric graphics content architecture in a basic layout object; +- defines the presentation attributes applicable to this geometric graphics content architecture; +- describes a content layout process, which together with the document layout process described in ITU-T Rec. T.412 | ISO/IEC 8613-2, describes the layout of geometric graphics content in basic layout objects and determines the dimensions of these basic layout objects. + +# 2 Normative references + +The following ITU-T/CCITT Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations | International Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent editions of the Recommendations and International Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The ITU-T Secretariat maintains a list of currently valid ITU-T/CCITT Recommendations. + +## 2.1 Identical Recommendations | International Standards + +- ITU-T Recommendation T.411 (1993) | ISO/IEC 8613-1:1994, *Information technology – Open Document Architecture (ODA) and Interchange Format: Introduction and general principles*. +- ITU-T Recommendation T.412 (1993) | ISO/IEC 8613-2:1994, *Information technology – Open Document Architecture (ODA) and Interchange Format: Document structures*. +- ITU-T Recommendation T.414 (1993) | ISO/IEC 8613-4:1994, *Information technology – Open Document Architecture (ODA) and Interchange Format: Document profile*. +- ITU-T Recommendation T.415 (1993) | ISO/IEC 8613-5:1994, *Information technology – Open Document Architecture (ODA) and Interchange Format: Open Document Interchange Format*. +- ITU-T Recommendation T.416 (1993) | ISO/IEC 8613-6:1994, *Information technology – Open Document Architecture (ODA) and Interchange Format: Character content architectures*. +- ITU-T Recommendation T.417 (1993) | ISO/IEC 8613-7:1994, *Information technology – Open Document Architecture (ODA) and Interchange Format: Raster graphics content architectures*. + +## 2.2 Paired Recommendations | International Standards equivalent in technical content + +- CCITT Recommendation X.208 (1988), *Specification of Abstract Syntax Notation One (ASN.1)*. +ISO/IEC 8824:1990, *Information technology – Open Systems Interconnection – Specification of Abstract Syntax Notation One (ASN.1)*. + +## 2.3 Additional references + +- ISO/IEC 646:1991, *Information technology – ISO 7-bit coded character set for information interchange*. +- ISO/IEC 8632-1:1992, *Information technology – Computer graphics – Metafile for the storage and transfer of picture description information – Part 1: Functional specification*. +- ISO/IEC 8632-3:1992, *Information technology – Computer graphics – Metafile for the storage and transfer of picture description information – Part 3: Binary encoding*. +- ISO 8879:1986, *Information processing – Text and office systems – Standard Generalized Markup Language (SGML)*. + +# 3 Definitions + +For the purposes of this Recommendation | International Standard, the definitions given in ITU-T Rec. T.411 | ISO/IEC 8613-1, ISO/IEC 8632-1 and ISO 8879 apply. + +# 4 Abbreviations + +For the purposes of this Recommendation | International Standard the abbreviations given in ITU-T Rec. T.411 | ISO/IEC 8613-1 apply. + +For the purposes of this Recommendation | International Standard the following additional abbreviations apply. + +| | | +|------|-----------------------------------------| +| ASF | Aspect source flag | +| CCA | Character content architecture | +| GGCA | Geometric graphics content architecture | +| NX | Number of columns in pattern array | +| NY | Number of rows in pattern array | +| VDC | Virtual Device Coordinate(s) | + +# 5 Conventions + +For the purposes of this Recommendation | International Standard the conventions given in ITU-T Rec. T.411 | ISO/IEC 8613-1 apply. + +The following additional conventions are used within this Recommendation | International Standard. + +## 5.1 CGM + +The term CGM is used to reference the Computer Graphics Metafile defined in ISO/IEC 8632. It is used as a qualifier for terms defined in ISO/IEC 8632 (for example, CGM elements). + +## 5.2 Individual CGM elements + +Throughout this Specification whenever individual CGM elements are referred to they are written in uppercase; for example, SCALING MODE. + +## 5.3 CGM concepts + +Whenever the concepts defined in CGM are referred to they are written in mixed upper and lower case as appropriate; for example, Direct Colour or Virtual Device Coordinates. + +## 5.4 CGM defaults + +This Specification uses the term *CGM defaults* whenever ISO/IEC 8632 uses the term *metafile defaults*. This is intended to indicate the different semantics, in conformance with 5.1, of the term *defaults* when used in the context of the ITU-T Rec. T.410-Series | ISO/IEC 8613 (ODA) or of ISO/IEC 8632 (CGM). + +## 5.5 Parameter names + +Whenever parameters or sub-parameters of presentation attributes defined in this Specification refer to elements or parameters defined in ISO/IEC 8632 the parameter names and sub-parameter names respectively, are written in mixed upper and lower case as appropriate; for example, Scaling Mode or Line Type. + +## 5.6 Width and height + +*Width* is used throughout this Specification to express the extent of a two-dimensional area in the direction given by the counter-clockwise rotation from the horizontal direction as specified by the geometric graphics presentation attribute “picture orientation”. + +*Height* is used throughout this Specification to express the extent of a two-dimensional area orthogonal to its width. + +NOTE – Width and height are mostly used in combination with a reference to an area; for example, width of the available area. + +# **6 General principles** + +## **6.1 Content architecture classes** + +This Specification defines one class of geometric graphics content architectures: + +- a formatted processable form, which allows for document content to be processed and also to be presented as intended by the originator. Formatted processable form content may be associated with any basic component. + +## **6.2 Content** + +A content portion that is structured according to a geometric graphics content architecture represents a single pictorial image. The representation is based on the Computer Graphics Metafile (CGM) defined in ISO/IEC 8632 (see 9.2). The functionality used in this Specification is limited to Version 1 metafiles. + +The CGM provides a format suitable for the storage, retrieval and interchange of picture description information. The format consists of an ordered set of elements. These elements are split into groups that + +- structure the information in the metafile; +- specify the precision of the values used within the metafile; +- control the display of the picture; +- perform basic drawing actions; +- control the attributes of the basic drawing actions; +- provide access to non-standard device capabilities. + +ISO/IEC 8632 defines the form (syntax) and the functional behaviour (semantics) of these elements. + +## **6.3 Presentation attributes** + +The geometric graphics content architecture defines geometric graphics presentation attributes applicable to basic layout and basic logical components. The geometric graphics presentation attributes direct the content layout process and specify the initial conditions at the start of the presentation of the content associated with a basic object. + +Only the geometric graphics presentation attributes specifying CGM defaults (see 8.1.1) may be overwritten by CGM elements in the content of the basic component to which they apply. + +The functionality represented by the geometric graphics presentation attributes specifying CGM defaults (see 8.1.1) and CGM element groups is that defined by ISO/IEC 8632-1 and ISO/IEC 8632-3, except that the defaulting rules are modified (see 12.2.1). + +All geometric graphics presentation attributes are: + +- non-mandatory for presentation styles; +- non-mandatory for object class descriptions; +- defaultable when applied to object descriptions. + +Presentation attributes are classified as shared attributes, layout attributes or logical attributes: + +- shared attributes are applicable to logical and layout components; +- layout attributes are applicable only to layout components; +- logical attributes are applicable only to logical components. + +## **6.4 Coding of content information** + +The ordered set of elements of the content portion is encoded according to the binary encoding defined in ISO/IEC 8632-3 and constitutes a complete CGM, which is limited to contain only one picture. + +## 6.5 Layout and imaging of the content + +The geometric graphics content architecture describes a content layout process which creates a basic layout object and determines the dimensions of this object into which the content associated with a basic logical object is to be laid out. + +It also describes a content imaging process which determines the image of the content. + +## 6.6 Colour spaces applicable to geometric graphics content architecture + +The geometric graphics content architecture may employ colour specification in RGB or CMY(K) when there is no internal CGM colour table (see Figure 1). The indexed colour expression is used when geometric graphics content employs indexed mode and does not contain a colour look-up table (LUT). The CMY(K) colour space is employed only in an indexed colour expression. + +![Figure 1: Relationships among the colour spaces for the Geometric Graphics Content Architecture. The diagram shows a flow from RGB and CMY(K) spaces through an optional transformation to a Reference CIE XYZ space, and then through a content imaging transformation to an Imaging System Colour Space.](5e92d9e8e9ce204e405bff2367f88176_img.jpg) + +``` + +graph TD + RGB[RGB] --> RXYZ[Reference CIE XYZ] + CMYK[CMY(K)] --> RXYZ + RXYZ --> ISCS[Imaging System Colour Space] + subgraph "Geometric Graphics Content Architecture" + RGB + CMYK + end + subgraph "Optional Transformation" + RXYZ + end + subgraph "Content Imaging Transformation" + ISCS + end + +``` + +The diagram illustrates the relationships between different color spaces in the Geometric Graphics Content Architecture. At the top, two boxes labeled 'RGB' and 'CMY(K)' are connected by lines to a central box labeled 'Reference CIE XYZ'. This central box is positioned between two horizontal dashed lines. The top dashed line is labeled 'Optional Transformation' on the right. The bottom dashed line is labeled 'Content Imaging Transformation' on the right. Below the bottom dashed line, a box labeled 'Imaging System Colour Space' is connected to the 'Reference CIE XYZ' box by a vertical line. The entire diagram is labeled 'T0812980-93/d01' in the bottom right corner. + +Figure 1: Relationships among the colour spaces for the Geometric Graphics Content Architecture. The diagram shows a flow from RGB and CMY(K) spaces through an optional transformation to a Reference CIE XYZ space, and then through a content imaging transformation to an Imaging System Colour Space. + +**Figure 1 – Relationships among the colour spaces for the Geometric Graphics Content Architecture** + +# 7 Positioning + +## 7.1 Introduction + +This clause describes the general principles concerning the positioning of a part of the VDC Space within basic layout objects. + +This part is known as the *region of interest*. It is a rectangular region within the VDC Space, and is defined by two VDC pairs termed *First Corner* and *Second Corner*. + +NOTE – The VDC Space is used within ISO/IEC 8632 for positioning geometric graphics elements, specifying directions, dimensions, etc. + +## 7.2 Measurement units and directions + +The positioning of geometric graphics content within a basic layout object is specified with relation to an orthogonal coordinate system. + +The definition of the region of interest specifies the origin and directions of the axes of the coordinate system, with respect to the basic layout object. + +Figure 2 illustrates that depending on which coordinates of the VDC Space are referenced by First Corner and Second Corner the region of interest can affect the orientation of the axes used when imaging the geometric graphics content. + +The measurement units of the x- and y-axis of the coordinate system are determined by the relationship of the dimensions of the region of interest to the dimensions of the basic layout object. + +![Figure 2: Mapping of a virtual image defined in the VDC Space to an output medium using different region of interest specifications. The diagram shows a VDC Range containing a virtual image of a chair. Two regions of interest are defined: one with corners (1,3) and (5,6), and another with corners (1,6) and (5,3). These are mapped to two different output media, each showing the chair image within a rectangular frame with corners L (lower left) and R (upper right).](007b053fe94a8348f75128a584503fd0_img.jpg) + +VDC Range + +(1,6) (5,6) + +y + +(1,3) (5,3) + +x + +Virtual image in region of interest + +Region of interest [(1,3), (5,6)] + +Region of interest [(1,6), (5,3)] + +Output medium + +L R + +Output medium + +L R + +T0816750-94/d02 + +L Lower left corner of output medium +R Upper right corner of output medium + +Figure 2: Mapping of a virtual image defined in the VDC Space to an output medium using different region of interest specifications. The diagram shows a VDC Range containing a virtual image of a chair. Two regions of interest are defined: one with corners (1,3) and (5,6), and another with corners (1,6) and (5,3). These are mapped to two different output media, each showing the chair image within a rectangular frame with corners L (lower left) and R (upper right). + +**Figure 2 – Mapping of a virtual image defined in the VDC Space to an output medium (e.g. a softcopy device) using different region of interest specifications** + +## 7.3 The relationship between the region of interest and the basic layout object + +When imaging geometric graphics content, the geometric graphics presentation attribute “picture orientation” determines the relationship of the First Corner of the region of interest to the corners of the basic layout object. + +The First Corner of the region of interest is coincident with the corner of the basic layout object defined by the geometric graphics presentation attribute “picture orientation” (for example, the bottom left corner if the presentation attribute “picture orientation” has the value ‘d0’, see 8.1.3). The Second Corner of the region of interest is coincident with the diagonally opposite corner of the basic layout object. It is implied that the x-axis of the VDC Space always maps to the direction parallel to the width of the basic layout object. Figures 3 and 4 illustrate this mapping. + +CGM picture with region of interest [(1,3), (5,6)] as normally mapped to an output medium +the dotted line represents the region of interest +the arrows indicate the direction of increasing coordinate values + +![Diagram showing a CGM picture with a region of interest (ROI) defined by a dotted rectangle. The ROI corners are labeled (1,3) at the bottom-left and (5,6) at the top-right. The picture contains a stylized object with horizontal lines and a black circle. Arrows on the x and y axes indicate increasing coordinate values.](bb6d33498937738ff5dac8d91c9ebaad_img.jpg) + +Diagram showing a CGM picture with a region of interest (ROI) defined by a dotted rectangle. The ROI corners are labeled (1,3) at the bottom-left and (5,6) at the top-right. The picture contains a stylized object with horizontal lines and a black circle. Arrows on the x and y axes indicate increasing coordinate values. + +The picture above is imaged into the basic layout object as shown. The heavy border represents the boundary of the basic layout object. + +![Four diagrams showing the mapping of the CGM picture into a basic layout object for different orientations: 0°, 90°, 180°, and 270°. Each diagram shows the object within a heavy-bordered rectangle. For 0°, the ROI is [(1,3), (5,6)] with x increasing right and y increasing up. For 90°, the ROI is [(5,6), (1,3)] with x increasing right and y increasing down. For 180°, the ROI is [(5,6), (1,3)] with x increasing left and y increasing down. For 270°, the ROI is [(1,3), (5,6)] with x increasing right and y increasing up.](e6b5ee67ac260b0a3ed3e3c5ad7ea19c_img.jpg) + +Picture orientation 0° (5,6) +Picture orientation 90° (5,6) +Picture orientation 180° (1,3) +Picture orientation 270° (1,3) + +T0816760-94/d03 + +Four diagrams showing the mapping of the CGM picture into a basic layout object for different orientations: 0°, 90°, 180°, and 270°. Each diagram shows the object within a heavy-bordered rectangle. For 0°, the ROI is [(1,3), (5,6)] with x increasing right and y increasing up. For 90°, the ROI is [(5,6), (1,3)] with x increasing right and y increasing down. For 180°, the ROI is [(5,6), (1,3)] with x increasing left and y increasing down. For 270°, the ROI is [(1,3), (5,6)] with x increasing right and y increasing up. + +Figure 3 – Relationship of region of interest to the basic layout object (right handed axes) + +CGM picture with region of interest [(1,6), (5,3)] as normally mapped to an output medium +the dotted line represents the region of interest +the arrows indicate the direction of increasing coordinate values + +![Diagram showing a CGM picture with a region of interest (ROI) defined by a dotted rectangle. The ROI corners are labeled (1,6) at the bottom-left and (5,3) at the top-right. The picture contains a stylized object with horizontal lines and a black circle. Arrows on the x and y axes indicate increasing coordinate values.](9999a06627f39a35b608912ed95b09ac_img.jpg) + +Diagram showing a CGM picture with a region of interest (ROI) defined by a dotted rectangle. The ROI corners are labeled (1,6) at the bottom-left and (5,3) at the top-right. The picture contains a stylized object with horizontal lines and a black circle. Arrows on the x and y axes indicate increasing coordinate values. + +The picture above is imaged into the basic layout object as shown. The heavy border represents the boundary of the basic layout object. + +![Four diagrams showing the mapping of the CGM picture into a basic layout object for different orientations: 0°, 90°, 180°, and 270°. Each diagram shows the object within a heavy-bordered rectangle. For 0°, the ROI is [(1,6), (5,3)] with x increasing right and y increasing up. For 90°, the ROI is [(5,3), (1,6)] with x increasing right and y increasing down. For 180°, the ROI is [(5,3), (1,6)] with x increasing left and y increasing down. For 270°, the ROI is [(1,6), (5,3)] with x increasing right and y increasing up.](9d1abc573e35610946ece87a18cbe862_img.jpg) + +Picture orientation 0° (5,3) +Picture orientation 90° (5,3) +Picture orientation 180° (1,6) +Picture orientation 270° (1,6) + +T0816770-94/d04 + +Four diagrams showing the mapping of the CGM picture into a basic layout object for different orientations: 0°, 90°, 180°, and 270°. Each diagram shows the object within a heavy-bordered rectangle. For 0°, the ROI is [(1,6), (5,3)] with x increasing right and y increasing up. For 90°, the ROI is [(5,3), (1,6)] with x increasing right and y increasing down. For 180°, the ROI is [(5,3), (1,6)] with x increasing left and y increasing down. For 270°, the ROI is [(1,6), (5,3)] with x increasing right and y increasing up. + +Figure 4 – Relationship of region of interest to the basic layout object (left handed axes) + +# 8        **Definition of geometric graphics presentation attributes** + +Presentation attributes specify the constraints and initial conditions relating to the layout and imaging of a basic component. They may be specified for basic layout components, presentation styles and default value lists. + +The following categories of presentation attributes are defined: + +- logical presentation attributes which take effect during the content layout process but are ignored during the content imaging process; + - shared presentation attributes which take effect during both the content layout and imaging processes. +- NOTE – For this content architecture no layout presentation attributes are defined. + +The geometric graphics presentation attributes are summarized in Table 1. + +**Table 1 – Geometric graphics presentation attributes** + +| Shared attributes | Logical attributes | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------| +| Line rendition<br>Marker rendition<br>Text rendition<br>Filled area rendition<br>Edge rendition<br>Colour representation<br>Transparency specification<br>Transformation specification<br>Region of interest specification<br>Picture orientation | Picture dimensions | + +During the layout and imaging processes, the values of the presentation attributes are evaluated in the following order: + +- 1) transformation specification; +- 2) other presentation attributes in arbitrary order. + +For each presentation attribute, a default value is defined. This value is used in the defaulting rules as defined in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +This clause also defines values specific to the geometric graphics content architecture for the attribute “content architecture class” as defined in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +## **8.1        Shared presentation attributes** + +### **8.1.1      Attributes specifying CGM defaults** + +The following presentation attributes provide information used for the construction and interpretation of the CGM defaults. They provide information used by the layout and imaging processes. + +The default values given for the parameters of these presentation attributes have been derived from the defaults of the corresponding CGM elements as given in ISO/IEC 8632-1 and ISO/IEC 8632-3. + +NOTE – Defaults for parameters specifying Direct Colour Values are given either as *foreground* representing the foreground colour, or *background* representing the background colour. The choice of foreground and background colour is implementation dependent. For reproduction on paper the background colour will normally be the colour of the paper, e.g. white, and the foreground colour a contrasting colour, e.g. black. + +The values of the CGM defaults attributes applicable to a basic object are determined by the defaulting rules defined in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +The value of each parameter of a CGM defaults attribute is + +- the value specified; +- if a value is not specified, the value defined in the specification of the default values for the attribute applicable to this parameter. + +This Specification does not contain definitions of the semantics of parameters of presentation attributes specifying CGM defaults which have the same semantics as CGM elements or parameters of these CGM elements with corresponding names defined in ISO/IEC 8632-1. This clause and its sub-clauses contain only definitions of the semantics of parameters for which the definitions differ from the definitions given in ISO/IEC 8632-1 and those parameters which are not defined in ISO/IEC 8632-1. + +For certain parameters the CGM defines value ranges as being reserved for registration. The meanings of these values may be defined using the established procedures of the ISO International Registration Authority for Graphical Items. + +The specification of the parameters of the CGM defaults attributes, their permissible values and default values is made in tabular form. Some of these parameters have values composed of several sub-parameters. They are shown indented beyond the parameters. The sub-parameters may be further substructured. This is shown by further indentation. + +Tables 2, 3 and 4 define the default values for the bundle representations, the pattern representations and colour representations, respectively. These tables are used when determining the default state of the imaging process (see 12.2.1). + +**Table 2 – Default bundle representations** + +| Representations | Bundle Index | | | | | +|----------------------------------------------|---------------------------------------------------------------------------|---------------------------------------------------------------------------|---------------------------------------------------------------------------|---------------------------------------------------------------------------|---------------------------------------------------------------------------| +| | 1 | 2 | 3 | 4 | 5 | +| Line | | | | | | +| Line Type | 1 (solid) | 2 (dash) | 3 (dot) | 4 (dash-dot) | 5 (dash-dot-dot) | +| Line Width<br>(if scaled)<br>(if absolute) | 1.0<br>$0.001 \times \text{length of longest side of default VDC Extent}$ | 1.0<br>$0.001 \times \text{length of longest side of default VDC Extent}$ | 1.0<br>$0.001 \times \text{length of longest side of default VDC Extent}$ | 1.0<br>$0.001 \times \text{length of longest side of default VDC Extent}$ | 1.0<br>$0.001 \times \text{length of longest side of default VDC Extent}$ | +| Line Colour<br>(if indexed)<br>(if direct) | 1<br>foreground | 1<br>foreground | 1<br>foreground | 1<br>foreground | 1<br>foreground | +| Marker | | | | | | +| Marker Type | 1 (dot) | 2 (plus) | 3 (asterisk) | 4 (circle) | 5 (cross) | +| Marker Size<br>(if scaled)<br>(if absolute) | 1.0<br>$0.01 \times \text{length of longest side of default VDC Extent}$ | 1.0<br>$0.01 \times \text{length of longest side of default VDC Extent}$ | 1.0<br>$0.01 \times \text{length of longest side of default VDC Extent}$ | 1.0<br>$0.01 \times \text{length of longest side of default VDC Extent}$ | 1.0<br>$0.01 \times \text{length of longest side of default VDC Extent}$ | +| Marker Colour<br>(if indexed)<br>(if direct) | 1<br>foreground | 1<br>foreground | 1<br>foreground | 1<br>foreground | 1<br>foreground | +| Text | | | | | | +| Font Index | 1 | 1 | None defined | None defined | None defined | +| Text Precision | string | character | | | | +| Character Expansion Factor | 1.0 | 0.7 | | | | +| Character Spacing | 0.0 | 0.0 | | | | +| Text Colour<br>(if indexed)<br>(if direct) | 1<br>foreground | 1<br>foreground | <br> | <br> | <br> | + +**Table 2 – (concluded) Default bundle representations** + +| Representations | Bundle Index | | | | | +|--------------------------------------------|---------------------------------------------------------------------------|---------------------------------------------------------------------------|---------------------------------------------------------------------------|---------------------------------------------------------------------------|---------------------------------------------------------------------------| +| | 1 | 2 | 3 | 4 | 5 | +| Filled Area | | | | | | +| Interior Style | hollow | hatch | hatch | hatch | hatch | +| Fill Colour<br>(if indexed)<br>(if direct) | 1<br>foreground | 1<br>foreground | 1<br>foreground | 1<br>foreground | 1<br>foreground | +| Hatch Index | 1<br>(horizontal equally spaced parallel lines) | 1<br>(horizontal equally spaced parallel lines) | 2<br>(vertical equally spaced parallel lines) | 3<br>(positive slope equally spaced parallel lines) | 4<br>(negative slope equally spaced parallel lines) | +| Pattern Index | 1 | 1 | 1 | 1 | 1 | +| Edge | | | | | | +| Edge Type | 1 (solid) | 2 (dash) | 3 (dot) | 4 (dash-dot) | 5 (dash-dot-dot) | +| Edge Width<br>(if scaled)<br>(if absolute) | 1.0<br>$0.001 \times \text{length of longest side of default VDC Extent}$ | 1.0<br>$0.001 \times \text{length of longest side of default VDC Extent}$ | 1.0<br>$0.001 \times \text{length of longest side of default VDC Extent}$ | 1.0<br>$0.001 \times \text{length of longest side of default VDC Extent}$ | 1.0<br>$0.001 \times \text{length of longest side of default VDC Extent}$ | +| Edge Colour<br>(if indexed)<br>(if direct) | 1<br>foreground | 1<br>foreground | 1<br>foreground | 1<br>foreground | 1<br>foreground | + +**Table 3 – Default pattern representations** + +| Pattern Table Entry | Pattern Table Index | +|---------------------------------------------------------------|---------------------| +| | 1 | +| NX (number of columns in pattern array) | 1 | +| NY (number of rows in pattern array) | 1 | +| Local Colour Precision | 0 | +| Colour<br>Index Array (if indexed)<br>Value Array (if direct) | {1}<br>{foreground} | + +**Table 4 – Default colour representations** + +| Colour Table Entry | Colour Table Index | | +|---------------------|--------------------|------------| +| | 0 | 1 | +| Direct Colour Value | background | foreground | + +#### 8.1.1.1 Line rendition + +The presentation attribute “line rendition” sets default values used for the presentation of the line primitives in the geometric graphics content portion. It specifies the default values for the Line Width Specification Mode, the Line Bundle Index, the individual CGM line attributes, the line aspect source flags and specifies the default line bundle representations. Table 5 summarizes the permissible values and the default values for the individual parameters and sub-parameters of this presentation attribute. + +**Table 5 – Structure, permissible values and default values of the attribute “line rendition”** + +| Parameter | Permissible values | Default | +|--------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------|-----------------------------------------------------------------------| +| Line Width Specification Mode | absolute, scaled | scaled | +| Line Bundle Index | any integer > 0 | 1 | +| Line Type | 1 through 5 plus any registered line type > 5<br>(see Note) | 1 (solid) | +| Line Width<br>(if scaled)<br>(if absolute) | any real $\geq 0.0$<br>any non-negative VDC Value | 1.0<br>$0.001 \times$ length of longest side<br>of default VDC Extent | +| Line Colour<br>(if indexed)<br>(if direct) | any integer $\geq 0$<br>any Direct Colour Value | 1<br>foreground | +| line aspect source flags | any three-tuple of<br>(Line Type ASF, Line Width ASF, Line Colour ASF) | | +| Line Type ASF | bundled, individual | individual | +| Line Width ASF | bundled, individual | individual | +| Line Colour ASF | bundled, individual | individual | +| line bundle specifications | any list containing zero, one or more entries | empty list | +| Line Bundle Index | any integer > 0 | | +| line bundle representation | any three-tuple of<br>(Line Type, Line Width, Line Colour) | | +| Line Type | as for individual | | +| Line Width<br>(if scaled)<br>(if absolute) | as for individual<br>as for individual | | +| Line Colour<br>(if indexed)<br>(if direct) | as for individual<br>as for individual | | +| NOTE – The permissible values of the parameter are restricted to values which are standardized and registered. Private values are not permitted. | | | + +The parameter “line bundle specifications” defines the initial line representations to be used for imaging a basic object. For each unspecified representation the values in Table 2 apply. + +This parameter consists of a list of zero, one or more entries. Each entry consists of the sub-parameters + +- “Line Bundle Index”; +- “line bundle representation”, which supplies values for the bundled CGM line attributes. + +The parameters are independently defaultable. + +#### **8.1.1.2 Marker rendition** + +The presentation attribute “marker rendition” sets default values used for the rendition of the marker primitives in the geometric graphics content portion. It specifies the default values for the Marker Size Specification Mode, the Marker Bundle Index, the individual CGM marker attributes, the marker aspect source flags and specifies the default marker bundle representations. Table 6 summarizes the permissible values and the default values for the individual parameters and sub-parameters of this presentation attribute. + +**Table 6 – Structure, permissible values and default values of the attribute “marker rendition”** + +| Parameter | Permissible values | Default | +|--------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------|----------------------------------------------------------------------| +| Marker Size Specification Mode | absolute, scaled | scaled | +| Marker Bundle Index | any integer > 0 | 1 | +| Marker Type | 1 through 5 plus any registered marker type > 5<br>(see Note) | 3 (asterisk) | +| Marker Size<br>(if scaled)<br>(if absolute) | any real $\geq 0.0$<br>any non-negative VDC Value | 1.0<br>$0.01 \times$ length of longest side of<br>default VDC Extent | +| Marker Colour<br>(if indexed)<br>(if direct) | any integer $\geq 0$<br>any Direct Colour Value | 1<br>foreground | +| marker aspect source flags | any three-tuple of<br>(Marker Type ASF, Marker Size ASF, Marker Colour ASF) | | +| Marker Type ASF | bundled, individual | individual | +| Marker Size ASF | bundled, individual | individual | +| Marker Colour ASF | bundled, individual | individual | +| marker bundle specifications | any list containing zero, one or more elements | empty list | +| Marker Bundle Index | any integer > 0 | | +| marker bundle representation | any three-tuple of<br>(Marker Type, Marker Size, Marker Colour) | | +| Marker Type | as for individual | | +| Marker Size<br>(if scaled)<br>(if absolute) | as for individual<br>as for individual | | +| Marker Colour<br>(if indexed)<br>(if direct) | as for individual<br>as for individual | | +| NOTE – The permissible values of the parameter are restricted to values which are standardized and registered. Private values are not permitted. | | | + +The parameter “marker bundle specifications” defines the initial marker representations to be used for imaging a basic object. For each unspecified representation the values in Table 2 apply. + +This parameter consists of a list of zero, one or more entries. Each entry consists of the sub-parameters + +- “Marker Bundle Index”; +- “marker bundle representation”, which supplies values for the bundled CGM marker attributes. + +The parameters are independently defaultable. + +#### 8.1.1.3 Text rendition + +The presentation attribute “text rendition” sets default values used for the rendition of the text primitives in the geometric graphics content portion. It specifies the default values for the Font List, the Character Set List, the Character Coding Announcer, the Text Bundle Index, the individual CGM text attributes, the text aspect source flags and specifies the default text bundle representations. Table 7 summarizes the permissible values and the default values for the individual parameters and sub-parameters of this presentation attribute. + +The parameter “text bundle specifications” defines the initial text representations to be used for imaging a basic object. For each unspecified representation the values in Table 2 apply. + +This parameter consists of a list of zero, one or more entries. Each entry consists of the sub-parameters + +- “Text Bundle Index”; +- “text bundle representation”, which supplies values for the bundled CGM text attributes. + +The parameters are independently defaultable. + +**Table 7 – Structure, permissible values and default values of the attribute “text rendition”** + +| Parameter | Permissible values | Default | +|--------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Font List | any list of registered font names<br>(see Note) | list containing one element: the registered name of any font that can represent the nationality-independent character subset of ISO/IEC 646 | +| Character Set List | any list of<br>(Character Set Type,<br>Designation Sequence Tail) | | +| Character Set Type | 94-character sets, 96-character sets,<br>94-character multibyte sets,<br>96-character multibyte sets,<br>complete code | 94-character sets | +| Designation Sequence Tail | any registered designation sequence tail<br>(see Note) | designation sequence tail that is registered for a character set which includes the nationality-independent subset of ISO/IEC 646 in the positions specified in ISO/IEC 646 | +| Character Coding Announcer | basic 7-bit, basic 8-bit, extended 7-bit,<br>extended 8-bit (Note) | basic 7-bit | +| Text Bundle Index | any integer > 0 | 1 | +| Text Font Index | any integer > 0 | 1 | +| Text Precision | string, character, stroke | string | +| Character Expansion Factor | any real > 0.0 | 1.0 | +| Character Spacing | any real | 0.0 | +| Text Colour<br>(if indexed)<br>(if direct) | any integer $\geq 0$<br>any Direct Colour Value | 1<br>foreground | +| Character Height | any non-negative VDC Value | $0.01 \times$ length of the longest side of the default VDC Extent | +| Character Orientation | any pair of VDC Vectors which have non-zero length and are not collinear | ((0;1), (1;0)) | +| Text Path | right, left, up, down | right | +| Text Alignment | any four-tuple of<br>(Horizontal Alignment, Vertical Alignment,<br>Continuous Horizontal Alignment,<br>Continuous Vertical Alignment) | | +| Horizontal Alignment | normal horizontal, left, centre, right,<br>continuous horizontal | normal horizontal | +| Vertical Alignment | normal vertical, top, cap, half, base, bottom,<br>continuous vertical | normal vertical | +| Continuous Horizontal Alignment | any real | --- | +| Continuous Vertical Alignment | any real | --- | + +**Table 7 – (concluded) Structure, permissible values and default values of the attribute “text rendition”** + +| Parameter | Permissible values | Default | +|--------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------|------------| +| Character Set Index | any integer > 0 | 1 | +| Alternate Character Set Index | any integer > 0 | 1 | +| text aspect source flags | any five-tuple of<br>(Text Font Index ASF, Text Precision ASF,<br>Character Expansion Factor ASF,<br>Character Spacing ASF, Text Colour ASF) | | +| Text Font ASF | bundled, individual | individual | +| Text Precision ASF | bundled, individual | individual | +| Character Expansion Factor ASF | bundled, individual | individual | +| Character Spacing ASF | bundled, individual | individual | +| Text Colour ASF | bundled, individual | individual | +| text bundle specifications | any list containing zero, one or more entries | empty list | +| Text Bundle Index | any integer > 0 | | +| text bundle representation | any five-tuple of<br>(Text Font Index, Text Precision,<br>Character Expansion Factor,<br>Character Spacing, Text Colour) | | +| Text Font Index | as for individual | | +| Text Precision | as for individual | | +| Character Expansion Factor | as for individual | | +| Character Spacing | as for individual | | +| Text Colour<br>(if indexed) | as for individual | | +| (if direct) | as for individual | | +| NOTE – The permissible values of the parameter are restricted to values which are standardized and registered. Private values are not permitted. | | | + +#### 8.1.1.4 Filled area rendition + +The presentation attribute “filled area rendition” sets default values used for the presentation of the interior of filled area primitives of a geometric graphics content portion. It specifies the default values for the Fill Bundle Index, the individual CGM filled area attributes, the pattern representations, the filled area aspect source flags and default fill bundle representations, applicable to the interior region of the filled area. Table 8 summarizes the permissible values and the default values for the individual parameters and sub-parameters of this presentation attribute. + +The parameter “pattern table specifications” is a list which supplies a complete set of values for zero, one or more pattern table entries. For each unspecified pattern table entry the values in Table 3 apply. + +The parameter “fill bundle specifications” defines the initial bundle representations to be used for imaging a basic object. For each unspecified representation the values in Table 2 apply. + +This parameter consists of a list of zero, one or more entries. Each entry consists of the sub-parameters + +- “Fill Bundle Index”; +- “fill bundle representation”, which supplies values for the bundled CGM filled area attributes. + +The parameters are independently defaultable. + +**Table 8 – Structure, permissible values and default values of the attribute “filled area rendition”** + +| Parameter | Permissible values | Default | +|--------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------| +| Fill Bundle Index | any integer > 0 | 1 | +| Interior Style | hollow, solid, pattern, hatch, empty | hollow | +| Fill Colour<br>(if indexed)<br>(if direct) | any integer $\geq 0$<br>any Direct Colour Value | 1<br>foreground | +| Hatch Index | 1 through 6 plus any registered hatch<br>index > 6 (see Note) | 1<br>(horizontal equally spaced parallel lines) | +| Pattern Index | any integer > 0 | 1 | +| Fill Reference Point | any VDC Pair | First Corner of default VDC Extent | +| Pattern Size | any four-tuple of<br>(Height Vector X Component,<br>Height Vector Y Component,<br>Width Vector X Component,<br>Width Vector Y Component) | | +| Height Vector X Component | any VDC Value | 0 | +| Height Vector Y Component | any VDC Value | height of default VDC Extent | +| Width Vector X Component | any VDC Value | width of default VDC Extent | +| Width Vector Y Component | any VDC Value | 0 | +| pattern table specifications | any list containing zero, one or more<br>Pattern Table elements | empty list | +| Pattern Table Index | any integer > 0 | | +| NX (number of columns in pattern) | any integer > 0 | | +| NY (number of rows in pattern) | any integer > 0 | | +| Local Colour Precision | 0, 1, 2, 4, 8, 16, 24, 32 | | +| Colour Index Array (if indexed) | $NX * NY$ cells of any integer $\geq 0$ | | +| Colour Value Array (if direct) | $NX * NY$ cells of any Direct Colour Value | | +| fill aspect source flags | any four-tuple of<br>(Interior Style ASF, Fill Colour ASF,<br>Hatch Index ASF, Pattern Index ASF) | | +| Interior Style ASF | bundled, individual | individual | +| Fill Colour ASF | bundled, individual | individual | +| Hatch Index ASF | bundled, individual | individual | +| Pattern Index ASF | bundled, individual | individual | +| fill bundle specifications | any list containing zero, one or more elements | empty list | +| Fill Bundle Index | any integer > 0 | | +| fill bundle representation | any four-tuple of<br>(Interior Style, Fill Colour,<br>Hatch Index, Pattern Index) | | +| Interior Style | as for individual | | +| Fill Colour<br>(if indexed)<br>(if direct) | as for individual<br>as for individual | | +| Hatch Index | as for individual | | +| Pattern Index | as for individual | | +| NOTE – The permissible values of the parameter are restricted to values which are standardized and registered. Private values are not permitted. | | | + +#### 8.1.1.5 Edge rendition + +The presentation attribute “edge rendition” sets default values used for the presentation of the edges of the filled area primitives in the geometric graphics content portion. It specifies the default values for the Edge Width Specification Mode, the Edge Visibility, the Edge Bundle Index, the individual CGM edge attributes, the edge aspect source flags, and specifies the default edge bundle representations, applicable to the boundary of the filled area. Table 9 summarizes the permissible values and the default values for the individual parameters and sub-parameters of this presentation attribute. + +The parameter “edge bundle specifications” defines the initial edge representations to be used for imaging a basic object. For each unspecified representation the values in Table 2 apply. + +This parameter consists of a list of zero, one or more entries. Each entry consists of the sub-parameters + +- “Edge Bundle Index”; +- “edge bundle representation”, which supplies values for the bundled CGM edge attributes. + +The parameters are independently defaultable. + +**Table 9 – Structure, permissible values and default values of the attribute “edge rendition”** + +| Parameter | Permissible values | Default | +|--------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------|--------------------------------------------------------------------| +| Edge Width Specification Mode | absolute, scaled | scaled | +| Edge Visibility | off, on | off | +| Edge Bundle Index | any integer > 0 | 1 | +| Edge Type | 1 through 5 plus any registered line type > 5 (see Note) | 1 (solid) | +| Edge Width<br>(if scaled)<br>(if absolute) | any real $\geq 0.0$<br>any non-negative VDC Value | 1.0<br>$0.001 \times$ length of longest side of default VDC Extent | +| Edge Colour<br>(if indexed)<br>(if direct) | any integer $\geq 0$<br>any Direct Colour Value | 1<br>foreground | +| edge aspect source flags | any three-tuple of<br>(Edge Type ASF, Edge Width ASF,<br>Edge Colour ASF) | | +| Edge Type ASF | bundled, individual | individual | +| Edge Width ASF | bundled, individual | individual | +| Edge Colour ASF | bundled, individual | individual | +| edge bundle specifications | any list containing zero, one or more elements | empty list | +| Edge Bundle Index | any integer > 0 | | +| edge bundle representation | any three-tuple of<br>(Edge Type, Edge Width, Edge Colour) | | +| Edge Type | as for individual | | +| Edge Width<br>(if scaled)<br>(if absolute) | as for individual<br>as for individual | | +| Edge Colour<br>(if indexed)<br>(if direct) | as for individual<br>as for individual | | +| NOTE – The permissible values of the parameter are restricted to values which are standardized and registered. Private values are not permitted. | | | + +#### 8.1.1.6 Colour representations + +The presentation attribute ‘‘colour representations’’ sets the default value for Background Colour and defines the initial colour representations to be used for imaging a basic object. Table 10 summarizes the permissible values and the default values for the individual parameters and sub-parameters of this presentation attribute. + +The parameter ‘‘colour table specifications’’ is a list which supplies a complete set of values for zero, one or more elements each of which supplies a list of Direct Colour Value specifications together with the index of the Starting Colour Table Entry for a continuous interval of one or more Colour Table Entries. For each unspecified colour representation the values of Table 4 apply. + +**Table 10 – Structure, permissible values and default values of the attribute ‘‘colour representations’’** + +| Parameter | Permissible values | Default | +|-------------------------------|------------------------------------------------------------------------------|------------| +| Background Colour | any Direct Colour Value | background | +| colour table specifications | any list containing zero, one or more elements | empty list | +| Starting Index<br>Colour List | any integer $\geq 0$<br>any list containing one or more Direct Colour Values | | + +#### 8.1.1.7 Transparency specification + +The presentation attribute ‘‘transparency specification’’ sets the default values for Transparency and Auxiliary Colour. Table 11 summarizes the permissible values and the default values for the individual parameters of this presentation attribute. + +NOTE – Auxiliary Colour as defined in ISO/IEC 8632 is intended to address hardware features commonly available in raster devices. Some devices may have no such capabilities, or may have a subset of these capabilities to which this parameter pertains. Simulations of such a feature may be very complex. ISO/IEC 8632 does not require that a CGM interpreter need simulate the feature when it is not available in the hardware or firmware. + +**Table 11 – Structure, permissible values and default values of the attribute ‘‘transparency specification’’** + +| Parameter | Permissible values | Default | +|-------------------------------------------------|-----------------------------------------------------|---------------------| +| Transparency | off, on | on | +| Auxiliary Colour<br>(if indexed)<br>(if direct) | <br>any integer $\geq 0$<br>any Direct Colour Value | <br>0<br>background | + +#### 8.1.1.8 Transformation specification + +The presentation attribute ‘‘transformation specification’’ sets the default values for VDC Extent, Clip Rectangle and Clip Indicator. Table 12 summarizes the permissible values and the default values for the individual parameters of this presentation attribute. + +The Virtual Device Coordinate (0;0) is the symbolic value of the origin of the coordinate system of the VDC Space. The Virtual Device Coordinate (1;1) is the symbolic value of + +- (1.0;1.0) for VDC Type ‘real’; +- (32767;32767) for VDC Type ‘integer’. + +The parameters are independently defaultable. + +**Table 12 – Structure, permissible values and default values of the attribute “transformation specification”** + +| Parameter | Permissible values | Default | +|----------------|----------------------------------------------|--------------------| +| VDC Extent | any two VDC Value pairs defining a rectangle | ((0;0), (1;1) ) | +| Clip Rectangle | any two VDC Value pairs defining a rectangle | same as VDC EXTENT | +| Clip Indicator | off, on | on | + +### 8.1.2 Region of interest specification + +CATEGORY: Shared + +STRUCTURE: + +One of the parameters “rectangle” or “automatic”. + +The parameter “rectangle” consists of the two sub-parameters “First Corner” and “Second Corner”. + +PERMISSIBLE VALUES: + +For the parameter “automatic”: ‘null’. + +For each of the sub-parameters “First Corner” and “Second Corner”: a pair of VDC Values. + +DEFAULT VALUES: + +The default value is the parameter “automatic” with the value ‘null’. + +DEFINITION: + +This presentation attribute specifies the region of interest used when laying out and imaging the content of the basic object. + +If the parameter “automatic” is specified the region of interest is the same as the VDC Extent. + +If coordinate pairs for the First Corner and Second Corner are specified using the parameter “rectangle” then the region of interest is specified by these values. + +### 8.1.3 Picture orientation + +CATEGORY: Shared + +PERMISSIBLE VALUES: + +One of the following: + +- ‘d0’ bottom left corner; +- ‘d90’ bottom right corner; +- ‘d180’ top right corner; +- ‘d270’ top left corner. + +DEFAULT VALUES: + +The default value is ‘d0’, bottom left corner. + +DEFINITION: + +This presentation attribute specifies with which corner of the basic layout object the First Corner of the region of interest is to be made coincident. + +## 8.2 Logical presentation attributes + +### 8.2.1 Picture dimensions + +CATEGORY: Logical + +STRUCTURE: + +One of the following four parameters: + +- a) “width controlled” +- b) “height controlled”; +- c) “area controlled”; +- d) “automatic”. + +The parameter “width controlled” has two sub-parameters “minimum width” and “preferred width”. + +The parameter “height controlled” has two sub-parameters “minimum height” and “preferred height”. + +The parameter “area controlled” has five sub-parameters: + +- “minimum width”; +- “preferred width”; +- “minimum height”; +- “preferred height”; +- “aspect ratio flag”. + +PERMISSIBLE VALUES: + +For the parameter “automatic”: ‘null’. + +For the sub-parameter “aspect ratio flag”: ‘fixed’ or ‘variable’. + +For all other sub-parameters: a non-negative integer value in SMUs. + +DEFAULT VALUE: + +The parameter “automatic” with the value ‘null’. + +DEFINITION: + +This presentation attribute specifies the intended dimensions of the basic layout object that is to contain the image defined by the geometric graphics content portion. + +The values of the sub-parameters “minimum width” and “preferred width” specify the lower limit and the upper limit of the allowed widths of the basic layout object. The value of the sub-parameter “minimum width” shall not be greater than the value of the sub-parameter “preferred width”. + +The values of the sub-parameters “minimum height” and “preferred height” specify the lower limit and the upper limit of the allowed heights of the basic layout object. The value of the sub-parameter “minimum height” shall not be greater than the value of the sub-parameter “preferred height”. + +If either or both of the values for the sub-parameters “preferred width” and “preferred height” are specified, the dimensions of the basic layout object shall be as close to the corresponding specified values as possible. + +If only the range of allowed widths for the basic layout object is specified (case a), this attribute specifies that the height of the basic layout object shall be such that the aspect ratio of the region of interest is maintained. + +If only the range of allowed heights for the basic layout object is specified (case b), this attribute specifies that the width of the basic layout object shall be such that the aspect ratio of the region of interest is maintained. + +If both the ranges of allowed widths and heights are specified (case c) the value of the sub-parameter “aspect ratio flag”, which is either “fixed” or “variable” determines whether or not the aspect ratio of the region of interest shall be maintained during the determination of the dimensions of the basic layout object. + +If neither the range of allowed heights nor the range of allowed widths is specified (case d), this attribute specifies that the width of the basic layout object shall be equal to the dimension of the available area in that direction and that the height is constrained to maintain the aspect ratio of the region of interest. + +## 8.3 Content architecture class attributes + +### 8.3.1 Content architecture class + +The value of the attribute “content architecture class” of a basic component description that conforms to this Specification is an ASN.1 object identifier with the value + +{ 2 8 2 8 0 } + +## 8.4 Interaction with document architecture attributes + +The value ‘concatenated’ of the layout directive attribute “concatenation” is ignored. This attribute is not taken into account during the layout of the geometric graphics content. + +The layout directive attribute “indivisibility” may be ignored. It provides no additional constraint for the geometric graphics content layout process. + +# 9 Geometric graphics content portion attributes + +## 9.1 Common coding attributes + +The value of the content portion attribute “type of coding” of a content portion description that conforms to this Specification is an ASN.1 object identifier with the value + +{ 2 8 3 8 0 } + +## 9.2 Content information + +The value of the content portion attribute “content information” of a content portion description that conforms to this Specification is an ASN.1 octet string representing a CGM conforming to the rules defined in ISO/IEC 8632-1 with the binary encoding defined in ISO/IEC 8632-3. + +The relationship between this Specification and ISO/IEC 8632 is such that + +- the string specified by the attribute “content information” in a geometric graphics content portion is a complete CGM as defined in ISO/IEC 8632-1 and ISO/IEC 8632-3; +- any Version 1 CGM as defined in ISO/IEC 8632-1 and ISO/IEC 8632-3 containing a single picture may be used as the value of a string specified by the attribute “content information” in a geometric graphics content portion. + +NOTE – The presentation attributes specifying CGM defaults (see 8.1.1) are provided for applying the factorization mechanism of an ODA environment to data that may be shared among several geometric graphics content portions. If a geometric graphics content portion is provided by importing a CGM into the ODA environment, then extreme care should be used in any attempt to assign this CGM as a data value for the content portion attribute “content information” and using the presentation attributes to change the default values of the CGM. The effects of changing the default values of such an imported CGM could quite possibly make the interpretation of the CGM non-sensible. The presentation attributes that should especially be considered are those that would cause graphical effects which are not intended (e.g. the presentation attribute “transformation specification”). + +## 9.3 Other coding attributes + +No other coding attributes are defined in this Specification. + +# 10 Formal definitions of geometric graphics content architecture dependent data types + +## 10.1 Introduction + +This clause contains the formal definitions, in ASN.1 notation (defined in ISO/IEC 8824 | CCITT Rec. X.208), of data types corresponding to presentation and coding attributes that are applicable to geometric graphics content architectures. + +Annex C contains the SGML representation of attributes specific to the geometric graphics content architecture. + +These data types are + +- the data type to represent the geometric graphics content architecture specific presentation attributes in basic layout components, presentation styles and default value lists; +- the data type to represent the geometric graphics content architecture specific coding attributes in content portions; +- the data type to represent the non-basic values of the geometric graphics content architecture presentation attributes in the document profile; +- the data type to represent the non-basic values of the geometric graphics content architecture coding attributes in the document profile; +- the data type to represent the non-standard default values of geometric graphics content architecture presentation and coding attributes in the document profile. + +## 10.2 Representation of geometric graphics presentation attributes + +The data type “Geometric-Graphics-Attributes” contains a set of subordinate data types that specify the geometric graphics presentation attributes. Some of these subordinate data types are elementary but others are structured and themselves made up of subordinate data types. The format of these data types is given below. + +**Geo-Gr-Presentation-Attributes { 2 8 1 8 2 }** + +**DEFINITIONS IMPLICIT TAGS ::= BEGIN** + +**EXPORTS** +**Geometric-Graphics-Attributes,** +**Line-Rendition, Marker-Rendition, Text-Rendition,** +**Filled-Area-Rendition, Edge-Rendition,** +**Colour-Representations,** +**Transparency-Specification, Transformation-Specification,** +**Region-Of-Interest-Specification, Picture-Orientation,** +**Picture-Dimensions, ASF-Type, VDC-Pair, One-Of-Four-Angles;** + +``` +Geometric-Graphics-Attributes ::= SET { +line-rendition [1] Line-Rendition OPTIONAL, +marker-rendition [2] Marker-Rendition OPTIONAL, +text-rendition [3] Text-Rendition OPTIONAL, +filled-area-rendition [4] Filled-Area-Rendition OPTIONAL, +edge-rendition [5] Edge-Rendition OPTIONAL, +colour-representations [6] Colour-Representations OPTIONAL, +transparency-specification [7] Transparency-Specification OPTIONAL, +transformation-specification [8] Transformation-Specification OPTIONAL, +region-of-interest-specification [9] Region-Of-Interest-Specification OPTIONAL, +picture-orientation [10] Picture-Orientation OPTIONAL, +picture-dimensions [11] Picture-Dimensions OPTIONAL } +``` + +**ASF-Type ::= ENUMERATED { bundled(0), individual(1) }** + +``` +Colour ::= CHOICE { +indexed [0] INTEGER, +direct [1] RGB } +``` + +``` +RGB ::= SEQUENCE { +red REAL, +green REAL, +blue REAL } +``` + +| | | +|--------------------------------|--------------------------------------------------------------------| +| <b>SpecificationMode ::=</b> | <b>ENUMERATED { absolute(0), scaled(1) }</b> | +| <b>Line-Rendition ::=</b> | <b>SEQUENCE {</b> | +| line-width-specification-mode | [0] SpecificationMode OPTIONAL, | +| line-bundle-index | [1] INTEGER OPTIONAL, | +| line-type | [2] INTEGER OPTIONAL, | +| line-width | [3] Scaled-or-Absolute OPTIONAL, | +| line-colour | [4] Colour OPTIONAL, | +| line-aspect-source-flags | [5] SEQUENCE { | +| line-type-asf | ASF-Type, | +| line-width-asf | ASF-Type, | +| line-colour-asf | ASF-Type } OPTIONAL, | +| line-bundle-specifications | [6] SEQUENCE OF SEQUENCE { | +| line-bundle-index | INTEGER, | +| line-bundle-representation | SEQUENCE { | +| line-type | INTEGER, | +| line-width | Scaled-or-Absolute, | +| line-colour | Colour } } OPTIONAL } | +| <b>Scaled-or-Absolute ::=</b> | <b>CHOICE {</b> | +| absolute | [0] CHOICE { | +| | [0] INTEGER,                 -- absolute | +| | [1] REAL },                -- for VDC Type INTEGER | +| scaled | [1] REAL }                         -- scaled | +| <b>Marker-Rendition ::=</b> | <b>SEQUENCE {</b> | +| marker-size-specification-mode | [0] SpecificationMode OPTIONAL, | +| marker-bundle-index | [1] INTEGER OPTIONAL, | +| marker-type | [2] INTEGER OPTIONAL, | +| marker-size | [3] Scaled-or-Absolute OPTIONAL, | +| marker-colour | [4] Colour OPTIONAL, | +| marker-aspect-source-flags | [5] SEQUENCE { | +| marker-type-asf | ASF-Type, | +| marker-size-asf | ASF-Type, | +| marker-colour-asf | ASF-Type } OPTIONAL, | +| marker-bundle-specifications | [6] SEQUENCE OF SEQUENCE { | +| marker-bundle-index | INTEGER, | +| marker-bundle-representation | SEQUENCE { | +| marker-type | INTEGER, | +| marker-size | Scaled-or-Absolute, | +| marker-colour | Colour } } OPTIONAL } | +| <b>Text-Rendition ::=</b> | <b>SEQUENCE {</b> | +| font-list | [0] SEQUENCE OF GeneralString OPTIONAL, | +| character-set-list | [1] SEQUENCE { | +| character-set-type | ENUMERATED { n94-char-sets (0), n96-char-sets (1), | +| | n94-char-multibyte-sets (2), | +| | n96-char-multibyte-sets (3), comp-code (4) }, | +| designation-sequence-tail | GeneralString } OPTIONAL, | +| character-coding-announcer | [2] ENUMERATED { basic-7-bit (0), basic-8-bit (1), | +| | extended-7-bit (2), | +| | extended-8-bit (3) } OPTIONAL, | +| text-bundle-index | [3] INTEGER OPTIONAL, | +| text-font-index | [4] INTEGER OPTIONAL, | +| text-precision | [5] ENUMERATED { string (0), character (1), stroke (2) } OPTIONAL, | +| character-expansion-factor | [6] REAL OPTIONAL, | +| character-spacing | [7] REAL OPTIONAL, | +| text-colour | [8] Colour OPTIONAL, | +| character-height | [9] VDC-Value OPTIONAL, | +| character-orientation | [10] SEQUENCE {VDC-Pair, VDC-Pair } OPTIONAL, | +| text-path | [11] ENUMERATED {right (0), left (1), up (2), down (3) } OPTIONAL, | + +| | | +|----------------------------------------|-----------------------------------------------------------------------------| +| <b>text-alignment</b> | <b>[12] SEQUENCE {</b> | +| <b>horizontal-alignment</b> | <b>ENUMERATED { normal-horizontal (0), left (1), centre (2), right (3),</b> | +| | <b>continuous-horizontal (4) },</b> | +| <b>vertical-alignment</b> | <b>ENUMERATED { normal-vertical (0), top (1), cap (2), half (3), base</b> | +| | <b>(4), bottom (5), continuous-vertical (6) },</b> | +| <b>continuous-horizontal-alignment</b> | <b>[0] REAL OPTIONAL,</b> | +| <b>continuous-vertical-alignment</b> | <b>[1] REAL OPTIONAL } OPTIONAL,</b> | +| <b>character-set-index</b> | <b>[13] INTEGER OPTIONAL,</b> | +| <b>alternate-character-set-index</b> | <b>[14] INTEGER OPTIONAL,</b> | +| <b>text-aspect-source-flags</b> | <b>[15] SEQUENCE {</b> | +| <b>text-font-asf</b> | <b>ASF-Type,</b> | +| <b>text-precision-asf</b> | <b>ASF-Type,</b> | +| <b>character-expansion-factor-asf</b> | <b>ASF-Type,</b> | +| <b>character-spacing-asf</b> | <b>ASF-Type,</b> | +| <b>text-colour-asf</b> | <b>ASF-Type } OPTIONAL,</b> | +| <b>text-bundle-specifications</b> | <b>[16] SEQUENCE OF SEQUENCE {</b> | +| <b>text-bundle-index</b> | <b>INTEGER,</b> | +| <b>text-bundle-representation</b> | <b>SEQUENCE {</b> | +| <b>text-font-index</b> | <b>INTEGER,</b> | +| <b>text-precision</b> | <b>ENUMERATED { string (0), character (1), stroke (2) },</b> | +| <b>character-expansion-factor</b> | <b>REAL,</b> | +| <b>character-spacing</b> | <b>REAL,</b> | +| <b>text-colour</b> | <b>Colour } } OPTIONAL }</b> | +| <br> | | +| <b>VDC-Value ::=</b> | <b>CHOICE {</b> | +| | <b>INTEGER,</b> | +| | <b>REAL }</b> | +| <br> | | +| <b>VDC-Pair ::=</b> | <b>SEQUENCE {</b> | +| <b>x</b> | <b>VDC-Value,</b> | +| <b>y</b> | <b>VDC-Value }</b> | +| <br> | | +| <b>Filled-Area-Rendition ::=</b> | <b>SEQUENCE {</b> | +| <b>fill-bundle-index</b> | <b>[1] INTEGER OPTIONAL,</b> | +| <b>interior-style</b> | <b>[2] ENUMERATED { hollow (0), solid (1), pattern (2),</b> | +| | <b>hatch (3), empty (4) } OPTIONAL,</b> | +| <b>fill-colour</b> | <b>[3] Colour OPTIONAL,</b> | +| <b>hatch-index</b> | <b>[4] INTEGER OPTIONAL,</b> | +| <b>pattern-index</b> | <b>[5] INTEGER OPTIONAL,</b> | +| <b>fill-reference-point</b> | <b>[6] VDC-Pair OPTIONAL,</b> | +| <b>pattern-size</b> | <b>[7] SEQUENCE {</b> | +| <b>height-x-component</b> | <b>VDC-Value,</b> | +| <b>height-y-component</b> | <b>VDC-Value,</b> | +| <b>width-x-component</b> | <b>VDC-Value,</b> | +| <b>width-y-component</b> | <b>VDC-Value } OPTIONAL,</b> | +| <b>pattern-table-specifications</b> | <b>[8] SEQUENCE OF PatternTableElement OPTIONAL,</b> | +| <b>fill-aspect-source-flags</b> | <b>[9] SEQUENCE {</b> | +| <b>interior-style-asf</b> | <b>ASF-Type,</b> | +| <b>fill-colour-asf</b> | <b>ASF-Type,</b> | +| <b>hatch-index-asf</b> | <b>ASF-Type,</b> | +| <b>pattern-index-asf</b> | <b>ASF-Type } OPTIONAL,</b> | +| <b>fill-bundle-specifications</b> | <b>[10] SEQUENCE {</b> | +| <b>fill-bundle-index</b> | <b>INTEGER,</b> | +| <b>fill-bundle-representation</b> | <b>SEQUENCE {</b> | +| <b>interior-style</b> | <b>ENUMERATED { hollow (0), solid (1), pattern (2),</b> | +| | <b>hatch (3), empty (4) },</b> | +| <b>fill-colour</b> | <b>Colour,</b> | +| <b>hatch-index</b> | <b>INTEGER,</b> | +| <b>patttern-index</b> | <b>INTEGER } } OPTIONAL }</b> | + +| | | +|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b>PatternTableElement ::=</b><br>pattern-table-index<br>nx<br>ny<br>local-colour-precision<br>colour | <b>SEQUENCE {</b><br>INTEGER,<br>INTEGER,<br>INTEGER,<br>INTEGER,<br>SEQUENCE OF Colour } | +| <b>Edge-Rendition ::=</b><br>edge-width-spec-mode<br>edge-visibility<br>edge-bundle-index<br>edge-type<br>edge-width<br>edge-colour<br>edge-aspect-source-flags<br>edge-type-asf<br>edge-width-asf<br>edge-colour-asf<br>edge-bundle-specifications<br>edge-bundle-index<br>edge-bundle-representation<br>edge-type<br>edge-width<br>edge-colour | <b>SEQUENCE {</b><br>[0] SpecificationMode OPTIONAL,<br>[1] On-or-Off OPTIONAL,<br>[2] INTEGER OPTIONAL,<br>[3] INTEGER OPTIONAL,<br>[4] Scaled-or-Absolute OPTIONAL,<br>[5] Colour OPTIONAL,<br>[6] SEQUENCE {<br>ASF-Type,<br>ASF-Type,<br>ASF-Type } OPTIONAL,<br>[7] SEQUENCE OF SEQUENCE {<br>INTEGER,<br>SEQUENCE {<br>INTEGER,<br>Scaled-or-Absolute,<br>Colour } } OPTIONAL } | +| <b>On-or-Off ::=</b> | <b>ENUMERATED { off (0), on (1) }</b> | +| <b>Colour-Representations ::=</b><br>background-colour<br>colour-table-specification<br>starting-index<br>colour-list | <b>SEQUENCE {</b><br>[0] RGB OPTIONAL,<br>[1] SEQUENCE OF SEQUENCE {<br>INTEGER,<br>SEQUENCE OF RGB } OPTIONAL } | +| <b>Transparency-Specification ::=</b><br>transparency<br>auxiliary-colour | <b>SEQUENCE {</b><br>[0] On-or-Off OPTIONAL,<br>[1] Colour OPTIONAL } | +| <b>Transformation-Specification ::=</b><br>vdc-extent<br>clip-rectangle<br>clip-indicator | <b>SEQUENCE {</b><br>[0] Rectangle OPTIONAL,<br>[1] Rectangle OPTIONAL,<br>[2] On-or-Off OPTIONAL } | +| <b>Rectangle ::=</b><br>first-corner<br>second-corner | <b>SEQUENCE {</b><br>VDC-Pair,<br>VDC-Pair } | +| <b>Region-Of-Interest-Specification ::=</b><br>automatic<br>rectangle | <b>CHOICE {</b><br>[0] NULL,<br>[1] SEQUENCE { VDC-Pair, VDC-Pair } } | +| <b>Picture-Orientation ::=</b> | <b>One-Of-Four-Angles</b> | +| <b>One-Of-Four-Angles ::=</b> | <b>ENUMERATED { d0(0), d90(1), d180(2), d270(3) }</b> | +| <b>Picture-Dimensions ::=</b><br>width-controlled<br>minimum-width<br>preferred-width<br>height-controlled<br>minimum-height<br>preferred-height<br>area-controlled<br>minimum-width<br>preferred-width<br>minimum-height<br>preferred-height<br>aspect-ratio-flag<br>automatic | <b>CHOICE {</b><br>[0] SEQUENCE {<br>INTEGER,<br>INTEGER },<br>[1] SEQUENCE {<br>INTEGER,<br>INTEGER },<br>[2] SEQUENCE {<br>INTEGER,<br>INTEGER,<br>INTEGER,<br>INTEGER,<br>ENUMERATED { fixed(0) , variable(1) } },<br>[3] NULL } | + +END + +## **10.3 Representation of coding attributes** + +``` + +Geo-Gr-Coding-Attributes { 2 8 1 8 3 } +DEFINITIONS ::= BEGIN +EXPORTS Geo-Gr-Coding-Attributes; +Geo-Gr-Coding-Attributes ::= SET { } + -- no geometric graphics coding attributes are defined + -- in this Specification +END + +``` + +## **10.4 Representation of non-basic features and non-standard defaults** + +``` + +Geo-Gr-Profile-Attributes { 2 8 1 8 4 } +DEFINITIONS IMPLICIT TAGS ::= BEGIN +EXPORTS Geo-Gr-Presentation-Feature, + Geo-Gr-Coding-Attribute, + Geo-Gr-Content-Defaults; + +IMPORTS Line-Rendition, Marker-Rendition, + Text-Rendition, Filled-Area-Rendition, Edge-Rendition, + Colour-Representations, Transparency-Specification, + Transformation-Specification, + Region-Of-Interest-Specification, + Picture-Orientation, Picture-Dimensions, ASF-Type, + VDC-Pair, One-Of-Four-Angles + FROM Geo-Gr-Presentation-Attributes { 2 8 1 8 2 }; -- see 10.2 + +Geo-Gr-Presentation-Feature ::= CHOICE { + text-rendition NULL, + [3] Text-Rendition } + +Geo-Gr-Coding-Attribute ::= NULL + -- no non-basic values are defined for the + -- geometric graphics coding attributes in this Specification + +Geo-Gr-Content-Defaults ::= SET { + line-rendition [1] Line-Rendition OPTIONAL, + marker-rendition [2] Marker-Rendition OPTIONAL, + text-rendition [3] Text-Rendition OPTIONAL, + filled-area-rendition [4] Filled-Area-Rendition OPTIONAL, + edge-rendition [5] Edge-Rendition OPTIONAL, + colour-representations [6] Colour-Representations OPTIONAL, + transparency-specification [7] Transparency-Specification OPTIONAL, + transformation-specification [8] Transformation-Specification OPTIONAL, + region-of-interest-specification [9] Region-Of-Interest-Specification OPTIONAL, + picture-orientation [10] Picture-Orientation OPTIONAL, + picture-dimensions [11] Picture-Dimensions OPTIONAL } + +END + +``` + +# **11 Content layout process** + +This clause describes a content layout process for basic logical objects associated with content architectures of type geometric graphics. + +Its purpose is to aid understanding of the semantics of the presentation attributes by describing the required results of such a process. However, it is not intended to specify any process that might be carried out in a particular implementation to achieve these results. + +## **11.1 Introduction** + +### **11.1.1 Purpose** + +The content layout process describes a process of laying out the geometric graphics content into an allocated area. This area is referred to as the available area and is determined by the document layout process described in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +The purpose of the content layout process is to convert content associated with basic logical components into content associated with basic layout objects. + +The content layout process results in the creation of a basic layout object into which the content shall be positioned. The dimensions of the basic layout object are returned to the document layout process which determines the precise position of that basic layout object within the available area. + +### **11.1.2 Available area** + +The content layout process is constrained by the available area. The maximum dimensions that a basic layout object can take are constrained by the dimensions of the available area. + +During the layout of content associated with a basic logical component into a basic layout object, the following cases can occur: + +- the formatted processable content fits into the dimensions of the available area; +- the formatted processable content does not fit into the dimensions of the available area; in this case, a new available area is required. + +### **11.1.3 Presentation attributes** + +The content layout process takes into account the presentation attributes applying to the basic logical object with which the content is associated. The content layout process takes also into account the region of interest that may depend on CGM elements in the content portion. + +The presentation attributes applying to the content layout process may be specified in the generic layout structure and presentation styles. The values of these presentation attributes are determined according to the defaulting rules specified in ITU-T Rec. T.412 | ISO/IEC 8613-2. + +### **11.1.4 Geometric graphics content architecture classes** + +The content layout process is specified for basic logical objects associated with the formatted processable form geometric graphics content architecture class. The content layout process does not modify the form of the content. + +### **11.1.5 Layout of the content** + +For the geometric graphics content architecture class, one case of laying out the content of basic logical objects into layout objects is possible: + +- single basic logical object to single basic layout object: the content associated with a single basic logical object may be laid out into a single basic layout object and is the only content associated with this basic layout object. + +## 11.2 Content layout process for formatted processable content architecture class + +Determination of the dimensions of the basic layout object depends on the value of the presentation attribute “picture dimensions” (the four possible cases are illustrated in Figures 5 to 8): + +- a) The presentation attribute “picture dimensions” specifies a value for the parameter “width controlled”. + +In this case the width of the picture will be within the range specified by the originator. + +The determination of the basic layout object dimensions is constrained by the range of allowed widths given by the value of the parameter “width controlled”, the dimensions of the available area and the aspect ratio of the region of interest. + +The dimensions of the basic layout object shall be determined such that the basic layout object fits into the available area; the aspect ratio of the basic layout object is the same as that of the region of interest; and the width of the basic layout object has a value that is within the range of allowed widths. The width of the basic layout object shall in addition be determined such that the deviation from the value of “preferred width”, specified by the parameter “width controlled”, is as small as possible. + +- b) The presentation attribute “picture dimensions” specifies a value for the parameter “height controlled”. + +In this case the height of the picture will be within the range specified by the originator. + +The determination of the basic layout object dimensions is constrained by the range of allowed heights given by the value of the parameter “height controlled”, the dimensions of the available area and the aspect ratio of the region of interest. + +The dimensions of the basic layout object shall be determined such that: the basic layout object fits into the available area; the aspect ratio of the basic layout object is the same as that of the region of interest; and the height of the basic layout object has a value that is within the range of allowed heights. The height of the basic layout object shall in addition be determined such that the deviation from the value of “preferred height”, specified by the parameter “height controlled”, is as small as possible. + +- c) The presentation attribute “picture dimensions” specifies a value for the parameter “area controlled”. + +In this case the dimensions of the picture will be within the range specified by the originator. In particular, this can be used to ensure that a picture will have a fixed size. + +The determination of the basic layout object dimensions is constrained by the range of allowed heights and widths given by the value of the parameter “area controlled”, the dimensions of the available area and, depending on the value of the sub-parameter “aspect ratio flag” of the parameter “area controlled”, by the aspect ratio of the region of interest. + +The dimensions of the basic layout object shall be determined such that the basic layout object fits into the available area; the width of the basic layout object has a value that is within the range of allowed widths; and the height of the basic layout object has a value that is within the range of allowed heights. If the value of the sub-parameter “aspect ratio flag” is ‘fixed’ there is the further constraint on the basic layout object dimensions, that the aspect ratio of the basic layout object shall be the same as that of the region of interest. Both the width and height of the basic layout object shall additionally be chosen such that their deviations from their preferred values, specified by the parameter “area controlled”, are both as small as possible. + +- d) The presentation attribute “picture dimensions” specifies the parameter “automatic” with the value ‘null’. + +In this case the picture dimensions are automatically adjusted to the page layout. + +The determination of the basic layout object dimensions is constrained by the dimensions of the available area and the aspect ratio of the region of interest. + +The dimensions of the basic layout object shall be determined such that the basic layout object fits into the available area; the width of the basic layout object is given the same value as the dimension of the available area in that direction; and the height of the basic layout object is determined such that the aspect ratio of the basic layout object dimensions is the same as that of the region of interest. + +![Diagram titled 'The Geometric Graphics Content' showing a rectangular frame. Inside, there is a geometric drawing of a four-legged object with horizontal lines and a large solid black circle to its right. An arrow from the text 'Region of interest' points to the black circle. Diagram of 'Assumed Page Layout A'. It shows a page border containing a small square in the top right corner, a horizontal box labeled 'Title', a horizontal box labeled 'Paragraph', and a large rectangular area at the bottom filled with a dot pattern labeled 'Available area'. Diagram of 'Alternate Assumed Page Layout B'. It shows a page border containing a small square in the top right corner, a horizontal box labeled 'Title', a large central box labeled 'Paragraph', and a smaller rectangular area at the bottom filled with a dot pattern labeled 'Available area'.](399a5af4f606059626c92c92279d54b7_img.jpg) + +The Geometric Graphics Content + +Region of interest + +Assumed Page Layout A + +Alternate Assumed Page Layout B + +T0816780-94/d05 + +Diagram titled 'The Geometric Graphics Content' showing a rectangular frame. Inside, there is a geometric drawing of a four-legged object with horizontal lines and a large solid black circle to its right. An arrow from the text 'Region of interest' points to the black circle. Diagram of 'Assumed Page Layout A'. It shows a page border containing a small square in the top right corner, a horizontal box labeled 'Title', a horizontal box labeled 'Paragraph', and a large rectangular area at the bottom filled with a dot pattern labeled 'Available area'. Diagram of 'Alternate Assumed Page Layout B'. It shows a page border containing a small square in the top right corner, a horizontal box labeled 'Title', a large central box labeled 'Paragraph', and a smaller rectangular area at the bottom filled with a dot pattern labeled 'Available area'. + +**Figure 5 – Diagrams used to illustrate the process of determining the basic layout object dimensions** + +![Diagram showing initial constraints for width-controlled and height-controlled picture dimensions. A central box contains a picture of a car. A dashed line from the top points to the box with the label 'Value of "picture dimensions": "width controlled"'. To the left, arrows indicate 'Preferred width' and 'Minimum width'. To the right, arrows indicate 'Minimum height' and 'Preferred height'. Below the box, 'Aspect ratio of region of interest' is labeled with arrows pointing to the width and height dimensions. Diagram showing allowable picture dimensions for width-controlled and height-controlled cases. The width-controlled case shows a hatched rectangle with 'Minimum height = minimum width/aspect ratio', 'Preferred width', and 'Minimum width' labeled. The height-controlled case shows a hatched rectangle with 'Minimum height', 'Preferred height', and 'Minimum width = minimum height x aspect ratio' labeled.](85e2327652d513a7fee8fdbf97ad06f1_img.jpg) + +Value of "picture dimensions": 'width controlled'      Value of "picture dimensions": 'height controlled' + +● *Initial constraints* + +Preferred width +Minimum width + +Aspect ratio of region of interest + +Minimum height +Preferred height + +● *Allowable picture dimensions* + +Minimum height = minimum width/aspect ratio +Preferred width +Minimum width + +Minimum height +Preferred height +Minimum width = minimum height $\times$ aspect ratio + +Diagram showing initial constraints for width-controlled and height-controlled picture dimensions. A central box contains a picture of a car. A dashed line from the top points to the box with the label 'Value of "picture dimensions": "width controlled"'. To the left, arrows indicate 'Preferred width' and 'Minimum width'. To the right, arrows indicate 'Minimum height' and 'Preferred height'. Below the box, 'Aspect ratio of region of interest' is labeled with arrows pointing to the width and height dimensions. Diagram showing allowable picture dimensions for width-controlled and height-controlled cases. The width-controlled case shows a hatched rectangle with 'Minimum height = minimum width/aspect ratio', 'Preferred width', and 'Minimum width' labeled. The height-controlled case shows a hatched rectangle with 'Minimum height', 'Preferred height', and 'Minimum width = minimum height x aspect ratio' labeled. + +NOTE – The hatched areas show a range of allowable picture dimensions. + +### ● *Basic layout object dimensions determined* + +![Diagram for Page layout A showing a rectangular area with 'Dimensions of available area' labeled. Below it, a hatched rectangle represents the picture dimensions, with a dashed-dotted boundary and 'Deviation' labeled. Diagram for Page layout B showing a rectangular area with 'Dimensions of available area' labeled. Below it, a hatched rectangle represents the picture dimensions, with a dashed-dotted boundary and 'Deviation' labeled.](9870bf462aa0d916a16d14b5a100c60a_img.jpg) + +(Page layout A) + +Dimensions of available area + +Deviation + +(Page layout B) + +Dimensions of available area + +Deviation + +Diagram for Page layout A showing a rectangular area with 'Dimensions of available area' labeled. Below it, a hatched rectangle represents the picture dimensions, with a dashed-dotted boundary and 'Deviation' labeled. Diagram for Page layout B showing a rectangular area with 'Dimensions of available area' labeled. Below it, a hatched rectangle represents the picture dimensions, with a dashed-dotted boundary and 'Deviation' labeled. + +###### NOTES + +- 1 The basic layout object is indicated by the dashed-dotted boundary. +- 2 For specifying range of allowed picture widths and layout A the preferred width cannot be satisfied due to the available width. +- 3 For specifying range of allowed picture heights and layout B the major constraint is the height of the available area. + +### ● *Basic objects laid out, positioned and imaged* + +NOTE – In this example the positioning of these basic layout objects assumes normal fill order, the attribute "block alignment" has the value 'centered' and a certain separation between two consecutive blocks. + +![Diagram showing two page layouts with basic objects laid out. The left layout shows a sequence of objects: a small rectangle, a larger rectangle, a picture of a car, and a box labeled 'Available area for next basic object'. The right layout shows a similar sequence but with different dimensions and positioning.](b2ddf2a678bd20b1b491023eb1db6458_img.jpg) + +Available area for next basic object + +Diagram showing two page layouts with basic objects laid out. The left layout shows a sequence of objects: a small rectangle, a larger rectangle, a picture of a car, and a box labeled 'Available area for next basic object'. The right layout shows a similar sequence but with different dimensions and positioning. + +T0816790-94/d06 + +Figure 6 – Layout process for the presentation attribute "picture dimensions" when a value is specified for the parameter "width controlled" or "height controlled" + +Value of the presentation attribute “picture dimensions”: ‘area controlled’ + +### ● *Initial constraints* + +![Diagram showing initial constraints for picture dimensions. It includes horizontal arrows for 'Preferred width' and 'Minimum width', and vertical arrows for 'Minimum height' and 'Preferred height'. A rectangle is shown with hatched areas indicating allowable dimensions.](2837ffdadcdb1e5bababa56b564e56ed_img.jpg) + +Preferred width +Minimum width +Minimum height +Preferred height + +Diagram showing initial constraints for picture dimensions. It includes horizontal arrows for 'Preferred width' and 'Minimum width', and vertical arrows for 'Minimum height' and 'Preferred height'. A rectangle is shown with hatched areas indicating allowable dimensions. + +NOTE – The hatched areas show a range of allowable picture dimensions. + +### ● *Allowable picture dimensions* + +The allowable picture dimensions are completely determined by the initial constraints + +### ● *Basic layout object dimensions determined (page layout A is used)* + +![Diagram illustrating the determination of basic layout object dimensions. It shows two paths: one for a 'fixed' aspect ratio flag leading to a specific object size, and another for a 'variable' aspect ratio flag leading to a different object size. Both paths start from 'Dimensions of available area' and end with a 'Deviation' measurement.](409498e57b1f988b2b604d12cd997002_img.jpg) + +Value of aspect ratio flag +'fixed' +Value of aspect ratio flag +'variable' +Dimensions of available area +Aspect ratio of region of interest +Deviation + +Diagram illustrating the determination of basic layout object dimensions. It shows two paths: one for a 'fixed' aspect ratio flag leading to a specific object size, and another for a 'variable' aspect ratio flag leading to a different object size. Both paths start from 'Dimensions of available area' and end with a 'Deviation' measurement. + +NOTE – The basic layout object is indicated by the dashed – dotted boundary. + +### ● *Basic objects laid out, positioned and imaged* + +NOTE – In this example the positioning of these basic layout objects assumes normal fill order, the attribute “block alignment” has the value ‘centered’ and a certain separation between two consecutive blocks. + +![Diagram showing two vertical layouts of basic objects. Each layout contains a header, a body, and a footer. The objects are centered and separated by space.](1dc5e74b1032f935e1b1ea3a9c876ac6_img.jpg) + +Diagram showing two vertical layouts of basic objects. Each layout contains a header, a body, and a footer. The objects are centered and separated by space. + +T0816800-94/d07 + +Figure 7 – Layout process for the presentation attribute “picture dimensions” when a value is specified for the parameter “area controlled” + +Value of the presentation attribute “picture dimensions”: ‘automatic’ + +### ● *Initial constraints* + +![Diagram showing initial constraints for layout. On the left, a rectangle contains a graphic of a chair and a black circle. An arrow points from this rectangle to the text 'Aspect ratio of region of interest'. On the right, a rectangle is labeled '(Page layout A)' and 'Available area'. Two arrows point from this rectangle: one to 'Width of available area' and another to 'Dimensions of available area'.](78ff716475b2f65bf01c3a4d02d89fc4_img.jpg) + +Diagram showing initial constraints for layout. On the left, a rectangle contains a graphic of a chair and a black circle. An arrow points from this rectangle to the text 'Aspect ratio of region of interest'. On the right, a rectangle is labeled '(Page layout A)' and 'Available area'. Two arrows point from this rectangle: one to 'Width of available area' and another to 'Dimensions of available area'. + +### ● *Allowable picture dimensions* + +![Diagram showing allowable picture dimensions. A dashed rectangle is shown with dimension lines. The width is labeled 'Width = width of available area' and the height is labeled 'Height = width of available area/aspect ratio'.](b2f5606b9c7184c1c6070a290080a3e3_img.jpg) + +Diagram showing allowable picture dimensions. A dashed rectangle is shown with dimension lines. The width is labeled 'Width = width of available area' and the height is labeled 'Height = width of available area/aspect ratio'. + +### ● *Basic layout object dimensions determined* + +![Diagram showing basic layout object dimensions determined. A shaded rectangle is shown within a larger dashed rectangle. An arrow points from the shaded rectangle to the text 'Dimensions of the basic layout object'. Another arrow points from the dashed rectangle to the text 'Dimensions of the available area'.](6be06b7dc72bb42afcb3465394667c3b_img.jpg) + +Diagram showing basic layout object dimensions determined. A shaded rectangle is shown within a larger dashed rectangle. An arrow points from the shaded rectangle to the text 'Dimensions of the basic layout object'. Another arrow points from the dashed rectangle to the text 'Dimensions of the available area'. + +### ● *Basic objects laid out, positioned and imaged* + +NOTE – In this example the positioning of these basic layout objects assumes normal fill order, the attribute “block alignment” has the value ‘centered’ and a certain separation between two consecutive blocks. + +![Diagram showing the final layout. A vertical rectangle contains several elements: a small square at the top right, a horizontal rectangle below it, another horizontal rectangle below that, a graphic of a chair and a black circle below that, and a shaded rectangle at the bottom labeled 'Available area for next basic object'.](02d0c8a07c481d880b73a25d02050fad_img.jpg) + +Diagram showing the final layout. A vertical rectangle contains several elements: a small square at the top right, a horizontal rectangle below it, another horizontal rectangle below that, a graphic of a chair and a black circle below that, and a shaded rectangle at the bottom labeled 'Available area for next basic object'. + +T0816810-94/d08 + +**Figure 8 – Layout process for the presentation attribute “picture dimensions” when a value is specified for the parameter “automatic”** + +If the given constraints cannot be met, then no dimensions of the basic layout object are determined. + +If the SCALING MODE is 'metric' it is required that the value of the parameter "area controlled" is the equivalent value in SMUs of the specified metric size, taking into account the document profile attribute "unit scaling". + +The dimensions of a basic layout object are restricted to integral multiples of 1 SMU. + +The presentation attribute "picture orientation" may rotate the region of interest. The rotated region of interest is used for the calculation of the basic layout object dimensions. + +# **12 Content imaging process** + +This clause describes a content imaging process for basic layout objects associated with content architectures of type geometric graphics. + +Its purpose is to aid understanding of the semantics of the presentation attributes by describing the required results of such a process. However, it is not intended to specify any process that might be carried out in a particular implementation to achieve these results. + +## **12.1 Introduction** + +The content imaging process is concerned only with the layout structures, the presentation styles and the content of basic layout components conforming to this Specification. + +The content imaging process is applicable to the formatted processable form geometric graphics content architecture class. + +## **12.2 Content imaging process for formatted processable form content architecture class** + +This clause describes how the various shared presentation attributes and CGM elements determine the image of the content. + +The imaging process is divided into two parts: + +- initialization; +- imaging. + +### **12.2.1 Initialization of the imaging process** + +At the start of the imaging of a geometric graphics content portion the imaging process is set to an initial state. The initial state of the imaging process is defined by the presentation attributes specifying CGM defaults (see 8.1.1) except for those parameters overwritten by CGM elements explicitly specified in the geometric graphics content portion. + +The imaging process uses bundle representations, pattern representations and colour representations specified by the bundle specification, pattern table specification and colour table specification parameter values, respectively, of the geometric graphics presentation attributes "line rendition", "marker rendition", "text rendition", "filled area rendition", "edge rendition" and "colour representations" in conjunction with the defaults for these representations defined in tables 2, 3 and 4. After it has been set to its initial state, the imaging process proceeds as if the CGM defaults have been explicitly specified in the content portion by CGM elements. + +### **12.2.2 Imaging** + +Within geometric graphics content, geometric graphics elements are positioned in a Virtual Device Coordinate Space using a Virtual Device Coordinate system. For each basic layout object a part of the Virtual Device Coordinate Space specified by the region of interest is imaged according to the geometric graphics positioning principles (see clause 7). No part of the graphical image which extends beyond the boundaries of the basic layout object is imaged. + +The imaging process ignores the element SCALING MODE as the required dimensions, and hence the aspect ratio, of the basic layout object have already been determined appropriately by the layout process. + +In the case where, for the basic layout object, the attribute "colour" has the value 'colour of media' and the attribute "transparency" has the value 'transparent', the picture descriptor element BACKGROUND COLOUR is ignored. + +The support of the CGM elements EXTERNAL and ESCAPE is not required. A valid interpretation is to ignore them. The use of private unregistered escapes is not supported in open systems interchange. + +Negative values of parameters of CGM elements are allowed. However, a valid interpretation is to ignore them; i.e. the use of private unregistered values is not supported in open systems interchange. + +The image of the graphic elements is as specified by ISO/IEC 8632-1. + +# 13 Definition of geometric graphics content architecture classes + +There is only one geometric graphics content architecture class. This content architecture class provides for formatted processable form content. It is characterized as follows: + +| | | +|---------------------------------------------|--------------------------------------------------------------------------------------| +| Content architecture class: | Formatted processable form | +| CGM elements: | All elements defined in ISO/IEC 8632-1<br>and ISO/IEC 8632-3 for Version 1 Metafiles | +| Type of coding: | As defined in ISO/IEC 8632-3 | +| Geometric graphics presentation attributes: | As listed in clause 8 | +| CGM attributes: | All CGM attributes defined for Version 1 Metafiles | + +# Annex A + +## Summary of ASN.1 object identifiers + +(This annex does not form an integral part of this Recommendation | International Standard.) + +Values of ASN.1 object identifiers are assigned in various clauses of this Specification. These assignments are summarized in Table A.1. + +Table A.1 – Summary of ASN.1 object identifiers + +| ASN.1 object identifier value | Description | Reference (Subclause) | +|-------------------------------|-----------------------------------------------------|-----------------------| +| { 2 8 2 8 0 } | Value of attribute “content architecture class” | 8.3 | +| { 2 8 3 8 0 } | Value of attribute “type of coding” | 9.1 | +| { 2 8 1 8 2 } | Identifies module<br>Geo-Gr-Presentation-Attributes | 10.2 | +| { 2 8 1 8 3 } | Identifies module<br>Geo-Gr-Coding-Attributes | 10.3 | +| { 2 8 1 8 4 } | Identifies module<br>Geo-Gr-Profile-Attributes | 10.4 | + +# Annex B + +## **Basic differences between character primitives in the geometric graphics and the content of a basic component structured according to the character content architectures defined in ITU-T Rec. T.416 | ISO/IEC 8613-6** (This annex does not form an integral part of this Recommendation | International Standard.) + +This annex identifies the basic differences between character strings regarded as graphical primitives and as character content. + +Within the geometric graphics content architecture (GGCA) the graphical primitive elements which may be used to describe a picture include a text primitive. The text primitive permits the inclusion of textual information in geometric graphics pictures. + +The most important basic differences between the text within the two different content architectures are as follows: + +- Within GGCA each primitive is conceptually independent of any other within the same content portion. Within the character content architecture (CCA) all content is a single text string. +- Within GGCA a text primitive may be positioned anywhere in the VDC Space. Within CCA the positioning of characters is sequential in nature and, therefore, the position at which a character is imaged is derived from the position at which its predecessor was imaged. +- Within GGCA the size of the basic layout object is not affected by the text within the content portion. Within CCA the size of the basic layout object is totally dependent on the amount of text within the content portion. +- Within GGCA the orientation of a text primitive may be set to any angle relative to the Virtual Device Coordinate system first axis. Within CCA the character path must be 0°, 90°, 180° or 270° relative to the horizontal axis of the layout object. +- Within GGCA the character size is specified by the CGM attribute elements CHARACTER HEIGHT and CHARACTER EXPANSION FACTOR and is conceptually independent of the font. This allows the aspect ratio of the character to be changed. Within CCA the character size is defined by the font. +- Within GGCA a text primitive is a geometric element and may undergo geometric transformation such as scaling and arbitrary rotation. Within CCA no such functionality exists. +- Within GGCA text primitives the effect of embedded control functions (e.g.: <CR>, <LF>) is not standardized. These control functions may occur but there is no definition of their semantics. Within CCA such control functions have a standardized effect. +- Within GGCA there is a character attribute which permits the inter-character space to be set or changed without constraint on a particular string of characters or a given line length. This permits the justification of either monospaced or proportionally spaced fonts. Within CCA, such justification may be specified as a requirement in the logical text, but resolves to embedded control functions working in units of SMU in the laid out (formatted) text. + +# Annex C + +## **SGML representation of geometric graphics content-specific attributes for ODL** + +(This annex forms an integral part of Recommendation | International Standard.) + +This annex is applicable to ISO/IEC 8613-8 only. + +NOTE – To maintain correspondence in clause numbering with ITU-T Recommendation T.418, this portion of the Office Document Language (ODL) is specified in an integral annex rather than in the body of this Specification. + +## **C.1 Introduction** + +This annex specifies a standardized SGML representation of attributes related to a geometric graphics content architecture, for use with the Office Document Language (ODL) defined in ISO/IEC 8613-5. ODL is an SGML application conforming to ISO 8879. + +The definitions of ISO 8879 apply to this annex. + +## **C.2 Names and public identifiers** + +The following notation declaration includes the public identifier of the data content notation for the content architecture class defined in this Specification. The ODL content architecture class name follows the prefix “ODA” in the notation name. + +``` +<! NOTATION ODAgfp PUBLIC “ISO/IEC 8613-8:1993//NOTATION +Geometric graphics formatted processable content architecture//EN”> +``` + +## **C.3 Representation of attribute values** + +Attribute values are represented in a clear-text equivalent of the CGM binary encoding, using the rules defined in this subclause. + +NOTE – The content portions themselves are encoded according to ISO/IEC 8632-3. The values of the attributes refer only to this encoding of the content, not to the encoding of the attribute values. + +The representations of the ODA attributes are presented in the form of SGML public text. In this form they can be referenced from a document rather than included within it. + +The semantics of the attribute values are specified in the body of this Specification. The representation of attribute values is as specified in the body of this Specification, except where a different representation is specified in the public text or elsewhere in this annex. + +The default values specified in the public text are those defined in the body of this Specification. If a different default value is wanted for an element (such as a non-standard default value specified in the document profile or in an object class description), the public text should not be referenced; instead, the definitions should be duplicated with the required changes made in the default values. + +Attribute values are sequences of one or more parameters, separated by SGML separator characters. An omitted parameter is represented by the keyword: 00. + +A parameter is either constructed, or is one of a number of primitive types: aspect source flags (ASF), keyword, integer, real, or string. String parameters are delimited, and may contain separator characters. Other parameters are not delimited, and cannot contain separator characters. + +### **C.3.1 Constructed parameters** + +In this Specification, a parameter whose permissible values include a pair, three-tuple, four-tuple, five-tuple, set, or list, is a constructed parameter. The sole exception is an ASF parameter (see C.3.6). + +A constructed parameter contains the required number of sub-parameters implied by its name, or its definition can permit it to be empty or to have a different number of sub-parameters. If more than one sub-parameter is present, they are separated from one another by commas. Adjacent commas denote an omitted sub-parameter, but they are required only if a succeeding sub-parameter is present. + +NOTE – See the specification of default values in the tables in 8.1 for examples of constructed parameters. + +#### **C.3.1.1 Parentheses** + +A constructed parameter is normally enclosed in parentheses, but they may be omitted if no ambiguity would be created by doing so. If a sub-parameter is itself constructed, it shall be enclosed in parentheses. + +An empty constructed parameter is represented by: ( ). + +#### **C.3.1.2 Alternative representation** + +The value of a constructed parameter can optionally be represented as the name of a data entity that contains the actual constructed parameter. + +NOTE – This technique can be used for long constructed parameters that would otherwise cause the quantity limits of the concrete syntax to be exceeded. + +#### **C.3.1.3 Default values** + +Parameters and sub-parameters are represented in attribute definitions in the same way as they are represented in attribute specifications. If the body of this Specification provides that the default value of a parameter or sub-parameter is determined by a formula, or by the value of other attributes, the default value is represented by the keyword “F”. + +### **C.3.2 String parameters** + +A string parameter could contain characters not permitted in an SGML name token, and it is therefore delimited by SGML LIT or LITA delimiters. + +A string parameter that is an escape sequence formulated in accordance with ISO 2022 is represented in the form used for the “public text designation sequence” defined in ISO 8879. + +NOTE – This is the clear text form commonly used in ISO standards. + +### **C.3.3 Keyword parameters** + +Possible keyword values are defined by the body of this Specification for some parameters, and by this annex for others. + +Lower-case letters in keyword parameters are treated as though they were uppercase. + +Certain keyword parameters defined for attributes are represented in ODL by abbreviated keywords, which are shown in uppercase in the following list: + +INTEger +INDExed +DIRect +ABSolute +SCAled +CHARacter + +For certain parameters whose permissible values constitute a set of keywords, fixed numerical values, or both keywords and fixed numerical values, the value is represented by choosing from a set of substitute keywords. These parameters are documented in comments in the public text, in the form: + +parameter name: keyword keyword .. + +with the keywords appearing in the same order as the permissible values that they represent appear within the body of this Specification. + +NOTE – For example +-- character set type: 94 96 94M 96M CC + +means that a value of “94” represents “(94-character sets)”, a value of “94M” represents “(94-character multibyte sets)”, and so on. + +### **C.3.4 Integer parameters** + +An integer is represented by a sequence of digits. If preceded by a hyphen, it represents a negative integer; otherwise, a positive integer. + +### C.3.5 Real parameters + +A real number is represented in floating point format: + +-d.dEd + +where each “d” represents a sequence of digits. + +### C.3.6 Aspect source flags (ASF) parameters + +A parameter identified as “aspect source flags” is an ASF parameter. Its permissible value is a sequence of the keywords “bundled” and “individual”, represented as a keyword consisting of an uninterrupted and undelimited sequence of “B” and “I” characters, respectively. + +NOTE – For example, the default value of the line aspect source flags parameter is represented as: III or, equivalently, iii. + +## C.4 Presentation attributes + +### C.4.1 Shared presentation attributes (format attribute-directives) + +<! -- © International Organisation for Standardization 1994 +Permission to copy in any form is granted for use with conforming SGML systems and applications as defined in ISO 8879, provided this notice is included in all copies. + +--> + +<! -- Public text entity. Typical invocation: + +<! ENTITY % g-p-ad PUBLIC “ISO/IEC 8613-8:1994 //TEXT +Geometric Presentation Format Attribute-Directives//EN”> + +<! ATTLIST gfp %g-p-ad;> + +--> + +gline CDATA -- line rendition -- +“sca 1 1 f f iii ()” + +gmarker CDATA -- marker rendition -- +“sca 1 3 f f iii ()” + +gtext CDATA -- text rendition -- +-- font name is a string -- +-- character set type: 94 96 94M 96M CC -- +-- designation sequence tail is a string, represented as a public text +designating sequence as defined in ISO 8879 -- +-- character coding announcer: B7 B8 E7 E8 -- +-- text path: R L U D -- +-- horizontal alignment: NH L C R CH -- +-- vertical alignment: NV T C H BA BO CV -- +“ ‘base font’ 94, ‘ESC 2/5 4/0’ b7 1 1 string 1.0 0.0 f f (0,1),(1,0) r nh,nv 1 1 iiiii ()” + +garea CDATA -- filled area rendition -- +-- interior style: HOL SOL PAT HAT EMP -- +“1 hol f 1 1 f 0,f,f,0 () iiiii ()” + +gedge CDATA -- edge rendition -- +“sca off 1 1 f f iii ()” + +gcolour CDATA “f ()” -- colour representations -- + +gtrnspar CDATA “on f” -- transparency specification -- + +gtrnsfor CDATA -- transformation specification -- +“(0,0),(1,1) f on” + +gregion CDATA “ “ -- region of interest specification -- + +gorient NUMBER 0 -- picture orientation: 0 90 180 270 -- + +### **C.4.2 Logical presentation attributes (format directives)** + +``` + +<!-- + © International Organization for Standardization 1994 + Permission to copy in any form is granted for use with conforming SGML systems + and applications as defined in ISO 8879, provided this notice is included in all copies. +--> +<!-- Public text entity. Typical invocation: +<! ENTITY %g-p-d PUBLIC "ISO/IEC 8613-8:1994//TEXT + Geometric Presentation Format Directives//EN"> + +<! ATTLIST gfp %g-p-d; > +--> + + gdim NAME auto -- picture dimensions: width height area auto -- + gdimsb NMTOKENS #IMPLIED -- picture dimensions sub-parameters -- + +``` + +## **C.5 Coding attributes** + +No geometric graphics coding attributes are defined for ODL. + +# Index + +Note – The number associated with the index entry indicates the page(s) where the index entry can be found. + +- Alternate Character Set Index, 14 +- ASN.1 object identifier, 34 +- aspect ratio, 32, 35 +- aspect ratio flag, 19 +- aspect source flags, 38 +- Auxiliary Colour, 17 +- available area, 26 +- Background Colour, 17, 32 +- bundle representations, 9, 10, 32 +- CGM + - binary encoding, 4, 36 + - concepts, 3 + - defaults, 3, 4, 8, 20, 32 + - elements, 3, 9 +- Character Coding Announcer, 13 +- Character Expansion Factor, 9, 13 +- Character Expansion Factor ASF, 14 +- Character Height, 13 +- Character Orientation, 13 +- character path, 35 +- Character Set Index, 14 +- Character Set List, 13 +- Character Set Type, 13 +- character size, 35 +- Character Spacing, 9, 13 +- Character Spacing ASF, 14 +- Clip Indicator, 18 +- Clip Rectangle, 18 +- coding attributes, 20, 39 + - representation of, 25 +- Colour Index Array, 10, 15 +- colour representations, 17, 32 +- colour specification, 5 +- Colour Table Entry, 10 +- colour table specifications, 17 +- Colour Value Array, 10, 15 +- concatenation, 20 +- content, 4 +- content architecture class, 4, 20, 26, 33, 34 +- content imaging process, 5, 32 +- content information, 20 +- content layout process, 5, 26 +- Continuous Horizontal Alignment, 13 +- Continuous Vertical Alignment, 13 +- control functions, 35 +- defaulting rules, 8 +- Designation Sequence Tail, 13 +- edge, 10 +- edge aspect source flags, 16 +- Edge Bundle Index, 16 +- edge bundle specifications, 16 +- Edge Colour, 10, 16 +- Edge Colour ASF, 16 +- edge rendition, 16, 32 +- Edge Type, 10, 16 +- Edge Type ASF, 16 +- Edge Visibility, 16 +- Edge Width, 10, 16 +- Edge Width ASF, 16 +- Edge Width Specification Mode, 16 +- fill aspect source flags, 15 +- Fill Bundle Index, 15 +- fill bundle specifications, 15 +- Fill Colour, 10, 15 +- Fill Colour ASF, 15 +- Fill Reference Point, 15 +- Filled Area, 10 +- filled area primitives + - edges, 16 + - interior, 14 +- filled area rendition, 14, 32 +- Font Index, 9 + +###### ISO/IEC 8613-8 : 1994 (E) + +- Font List, 13 +- formatted processable form, 4, 33 +- geometric graphics coding attributes, 34 +- geometric graphics positioning, 32 +- geometric graphics presentation attributes + - representation of, 21 +- Hatch Index, 10, 15 +- Hatch Index ASF, 15 +- height + - minimum, 19 + - preferred, 19, 27 +- Horizontal Alignment, 13 +- imaging, 6 +- imaging process, 8 + - default state, 9 +- indivisibility, 20 +- initial bundle representations, 14 +- initial edge representations, 16 +- initial line representation, 11 +- initial marker representation, 12 +- initial text representation, 13 +- inter-character space, 35 +- Interior Style, 10, 15 +- Interior Style ASF, 15 +- justification, 35 +- layout process, 8, 26 +- line, 9 +- line aspect source flags, 11 +- Line Bundle Index, 11 +- line bundle representation, 11 +- line bundle specifications, 11 +- Line Colour, 9, 11 +- Line Colour ASF, 11 +- line primitives, 11 +- line rendition, 11, 32 +- Line Type, 9, 11 +- Line Type ASF, 11 +- Line Width, 9, 11 +- Line Width ASF, 11 +- Line Width Specification Mode, 11 +- Local Colour Precision, 10, 15 +- marker, 9 +- marker aspect source flags, 12 +- Marker Bundle Index, 12 +- marker bundle specifications, 12 +- Marker Colour, 9 +- Marker Colour ASF, 12 +- marker primitives, 12 +- marker rendition, 12, 32 +- Marker Size, 9, 12 +- Marker Size Specification Mode, 12 +- Marker Type, 9, 12 +- measurement units, 5 +- non-basic features + - representation of, 25 +- non-basic values, 21 +- non-standard default values, 21, 34, 36 + - representation of, 25 +- Office Document Language, 36 +- Pattern Index, 10, 15 +- Pattern Index ASF, 15 +- pattern representations, 10, 32 +- Pattern Size, 15 +- Pattern Table Entry, 10 +- Pattern Table Index, 15 +- pattern table specifications, 15 +- picture dimensions, 19, 27 +- picture orientation, 6, 18 +- positioning within basic layout objects, 5 +- presentation attributes, 4, 8, 26 + - logical, 8, 19, 39 + - shared, 8, 38 +- presentation styles, 26 +- public identifier, 36 +- region of interest, 5, 18 + - aspect ratio of, 27 +- rotation, 35 +- scaling, 35 +- SCALING MODE, 32 +- text, 9 + +- Text Alignment, 13 +- text aspect source flags, 14 +- Text Bundle Index, 13 +- text bundle specifications, 14 +- Text Colour, 9, 13 +- Text Colour ASF, 14 +- Text Font ASF, 14 +- Text Font Index, 13 +- Text Path, 13 +- Text Precision, 9, 13 +- Text Precision ASF, 14 +- text primitive, 13, 35 +- text rendition, 13, 32 +- transformation specification, 8, 17, 20 +- transparency, 17 +- transparency specification, 17 +- type of coding, 20, 34 +- VDC Extent, 18 +- VDC Space, 5, 17, 32, 35 +- Vertical Alignment, 13 +- Virtual Device Coordinate pairs, 5 +- Virtual Device Coordinate System, 32 +- width + - minimum, 19 + - preferred, 19, 27 \ No newline at end of file diff --git a/marked/T/T-REC-T.441-198811-I_PDF-E/raw.md b/marked/T/T-REC-T.441-198811-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..2c9eefbeaa22855ffe6340c08a5039178d23ddef --- /dev/null +++ b/marked/T/T-REC-T.441-198811-I_PDF-E/raw.md @@ -0,0 +1,166 @@ + + +![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU and a lightning bolt symbol. + +INTERNATIONAL TELECOMMUNICATION UNION + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**T.441** + +**TERMINAL EQUIPMENT AND PROTOCOLS FOR +TELEMATIC SERVICES** + +--- + +**DOCUMENT TRANSFER AND MANIPULATION +(DTAM) - OPERATIONAL STRUCTURE** + +**ITU-T Recommendation T.441** + +(Extract from the *Blue Book*) + +--- + +## NOTES + +1 ITU-T Recommendation T.441 was published in Fascicle VII.7 of the *Blue Book*. This file is an extract from the *Blue Book*. While the presentation and layout of the text might be slightly different from the *Blue Book* version, the contents of the file are identical to the *Blue Book* version and copyright conditions remain unchanged (see below). + +2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# **DOCUMENT TRANSFER AND MANIPULATION (DTAM) – OPERATIONAL STRUCTURE** + +## CONTENTS + +## *Scope* + +- 1 *Overview of operational concept* +- 2 *Operational application profile rules* +- 3 *Operational structures* +- 4 *Operational reference model* +- 5 *Operational profile information* +- 6 *Operational data formats* + +## Scope + +This Recommendation has been established to cover the needs of videotex interworking. It will be further developed to cover the needs of other telematic services. + +The operational structure should be developed as a set of rules for an interface between telematic applications based on T.400 Series of Recommendations and an ODA-document. + +## **1 Overview of operational concept** + +A document is defined in terms of logical and/or layout structure according to the specifications of the T.410 Series of Recommendations. + +The basic principle of the operational concept is to provide the means for the integration of telematic services requirements, not covered by the T.410 Series of Recommendations within the applications on the top of DTAM (see Figure I/T.441). + +![Diagram of DTAM overview showing the relationship between DTAM user (Document and Operational structure), DTAM services, and Communication functions (Association use control, Capability, Document bulk transfer, Document manipulation, Typed data transfer, Session management). A DTAM protocol arrow is shown on the right.](5d92d5c9cc01a262b0389d138caa9aea_img.jpg) + +FIGURE 1/T.441 + +**Overview of DTAM (including operational structure)** + +Diagram of DTAM overview showing the relationship between DTAM user (Document and Operational structure), DTAM services, and Communication functions (Association use control, Capability, Document bulk transfer, Document manipulation, Typed data transfer, Session management). A DTAM protocol arrow is shown on the right. + +Document handling, *e.g.* access to parts of a document and manipulation of a document requires detailed considerations; two aspects of document handling shall be distinguished: + +- a) In addition to the document, structural concepts need to be defined in T.400 Series of Recommendations; these concepts shall define the structural aspect of the document handling (as for example "forms for data entry"). +*Note* – The definition of structural concepts is not in the scope of this Recommendation. Specifications concerning such concepts require further detailed study. +- b) In addition to the document, applications may require operational features which provide information for the interface between the document and the application. Interfaces are for example necessary for "Data Entry", "Spread Sheet", "Remote Editing", etc. + +As an application on top of DTAM shall solely use DTAM service and protocol, this Recommendation provides the operational concept which allows to integrate operational features within the concept of DTAM. + +The operational structure is introduced as a set of rules to structure the interface between a document and the application (see Figure 2/T.441). By defining a mapping onto the operational structure, the application integrates its operational features within DTAM. The mapping has to be specified within the appropriate Recommendation for the relevant application. The semantic of the interface is generally determined by the relevant application. + +2          **Fascicle VII.7 - Rec. T.441** + +T. 410 Series of Recommendations +provide the document structure + +![A hierarchical tree diagram representing document structure. It starts with a single root node at the top, which branches into two child nodes. These two nodes further branch into three child nodes each, resulting in a total of seven nodes. The nodes are represented by circles, and the connections between them are lines.](690fce4fb5c9cbb8beb560cb2a3fcbeb_img.jpg) + +A hierarchical tree diagram representing document structure. It starts with a single root node at the top, which branches into two child nodes. These two nodes further branch into three child nodes each, resulting in a total of seven nodes. The nodes are represented by circles, and the connections between them are lines. + +Additional features such as forms for +data entry, for further study + +This Recommendation provides +operational structures + +The application handles the +document in a specific way : +(For example data entry programs) +using the structured interface + +![A horizontal arrow pointing to the left, indicating a relationship or flow from the application handling the document to the operational structures provided by the recommendation.](446fd00eff6eb62c8d5eefa8a8aa3238_img.jpg) + +A horizontal arrow pointing to the left, indicating a relationship or flow from the application handling the document to the operational structures provided by the recommendation. + +T0801020-89 + +FIGURE 2/T.441 + +**Operational structures provide the information for a structured +interface between the document and the application** + +## 2 Operational application profile rules + +### 2.1 General principles + +This section specifies how operational application profiles can be implemented by using this Recommendation. Application defined usage of T.400 Series of Recommendations is specified in terms of application profiles. An application profile consists of a combination of: + +- document application profiles according to the rules defined in T.411; +- communication application profiles according to the rules defined in T.431; +- operational structure application profiles according to the rules which will be defined in this Recommendation. + +## 3 Operational structures + +This section describes the operational concept which is the basis for remote operation on a document. It facilitates access and manipulation to parts of a document through operations defined in T.430 Series of Recommendations. + +The concept can be used to associate application defined attributes and content with constituents of documents. For example, it may be used to specify fields for data entry and actions on the content of these fields. In this example, the semantics for data entry and actions may be expressed by the application. + +The operational structure follows in general the structuring principles typical of the document architecture as described in T.412. + +The constituents of the operational structure reference the document constituents they are operating on. + +Multiple operational structures may be defined referring to a single document class. + +## 4 Operational reference model + +This section describes the common understanding of operations on: + +- the document as a whole; +- parts of document. + +This section provides a narrative description of these operations. + +At present two types of operations will be defined: + +- partial document transfer; +- remote document update. + +Any complete set of operations on a document using the operational structure should result in document conforming to the rules of the T.410 Series of Recommendations. + +## **5 Operational profile information** + +An operational structure profile includes information concerning: + +- the reference to a document or a document class; +- application dependent references; +- operational structure level; +- the type of the content. + +## **6 Operational data formats** + +This section describes the format of the datastream used to interchange operational structures. + +The operational structure can be interchanged as a whole or in parts. + +The datastream is described in terms of a set of operational interchange data units which represent the constituents (e.g. operational profile, object class descriptors, object descriptors, and content) of an operational structure. + +The formats of the interchanged data units are defined using the abstract syntax notation one (ASN. 1). \ No newline at end of file diff --git a/marked/T/T-REC-T.501-199303-I_PDF-E/raw.md b/marked/T/T-REC-T.501-199303-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..0cdf80897efa7e073c0b1946858d5b7759197991 --- /dev/null +++ b/marked/T/T-REC-T.501-199303-I_PDF-E/raw.md @@ -0,0 +1,1103 @@ + + +![ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol below it.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol below it. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## T.501 + +(03/93) + +**TELEMATIC SERVICES** + +**TERMINAL EQUIPMENTS AND PROTOCOLS +FOR TELEMATIC SERVICES** + +--- + +**DOCUMENT APPLICATION PROFILE MM +FOR THE INTERCHANGE OF FORMATTED +MIXED MODE DOCUMENTS** + +**ITU-T Recommendation T.501** + +(Previously "CCITT Recommendation") + +--- + +# FOREWORD + +The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecommunication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +ITU-T Recommendation T.501 was revised by the ITU-T Study Group VIII (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). + +# --- NOTES + +1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector. + +In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms “CCITT, CCIR or IFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. + +2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# CONTENTS + +| | | <i>Page</i> | +|---|----------------------------------------------------------------------|-------------| +| 1 | Scope and field of application ..... | 1 | +| 2 | References ..... | 1 | +| 3 | Definitions and abbreviations ..... | 2 | +| | 3.1 Definitions ..... | 2 | +| | 3.2 Abbreviations ..... | 2 | +| 4 | Relationships with other profiles ..... | 2 | +| 5 | Conformance ..... | 2 | +| | 5.1 Data stream conformance ..... | 2 | +| | 5.2 Implementation conformance ..... | 2 | +| 6 | Characteristics supported by this document application profile ..... | 2 | +| | 6.1 Overview ..... | 2 | +| | 6.2 Logical characteristics ..... | 3 | +| | 6.3 Layout characteristics ..... | 3 | +| | 6.4 Document layout characteristics ..... | 5 | +| | 6.5 Content layout and imaging characteristics ..... | 6 | +| | 6.6 Miscellaneous features ..... | 13 | +| | 6.7 Document management features ..... | 13 | +| 7 | Specification of constituent constraints ..... | 15 | +| | 7.1 Document profile constraints ..... | 15 | +| | 7.2 Logical constituent constraints ..... | 19 | +| | 7.3 Layout constituent constraints ..... | 19 | +| | 7.4 Layout style constraints ..... | 20 | +| | 7.5 Presentation style constraints ..... | 20 | +| | 7.6 Content portion constraints ..... | 20 | +| 8 | Interchange format ..... | 21 | + +# INTRODUCTION + +This is the definition of an ODA document application profile (DAP) named MM. This DAP is suitable for interchanging mixed mode documents in formatted form. This DAP is defined in accordance with Recommendation T.411 and the format of this DAP is in accordance with the standardized proforma and notation defined in addendum to Annex F/T.411. + +# DOCUMENT APPLICATION PROFILE MM FOR THE INTERCHANGE OF FORMATTED MIXED MODE DOCUMENTS + +(Melbourne, 1988; revised at Helsinki, 1993) + +# 1 Scope and field of application + +This DAP specifies the interchange format suitable for the interchange of mixed mode documents such as memoranda, letters and reports. + +Mixed mode documents are interchanged only in a formatted form. The purpose of this DAP is to allow the transfer of the complete layout of the interchanged document. + +Furthermore, two types of content are allowed within the same page, namely: + +- a character content as used by word processing machines (e.g. basic teletex equipment); +- a raster graphics content as used by facsimile group 4 apparatus. + +This DAP is independent of the processes carried out in an end system to create or reproduce documents. It is also independent of the means to transfer documents which for example, may be by means of communication links or storage media. + +# 2 References + +- CCITT Recommendation T.411 (1988), *Open Document Architecture (ODA) and interchange format – Introduction and general principles.* +- CCITT Recommendation T.412 (1988), *Open Document Architecture (ODA) and interchange format – Document structures.* +- CCITT Recommendation T.414 (1988), *Open Document Architecture (ODA) and interchange format – Document profile.* +- CCITT Recommendation T.415 (1988), *Open Document Architecture (ODA) and interchange format – Open document interchange format.* +- CCITT Recommendation T.416 (1988), *Open Document Architecture (ODA) and interchange format – Character content architecture.* +- CCITT Recommendation T.417 (1988), *Open Document Architecture (ODA) and interchange format – Raster graphics content architecture.* +- CCITT Recommendation T.411.F (1991) (Annex F/T.411). +- ISO 8859-1, *Information Processing – 8-bit single-byte coded graphic character sets – Part 1: Latin Alphabet No. 1.* +- ISO 646: revised 1990, *Information Processing – ISO 7-bits coded character sets for information interchange.* +- ISO 6937-2, *Information Processing – Coded character sets for text communication – Part 2: Latin alphabet and non-alphabetic graphic characters.* +- ISO 2022, *Information Processing – ISO 7-bit and 8-bit coded character sets – Code extension techniques.* +- ISO 7350, *Text communication – Registration of graphic character subrepertoires.* +- CCITT Recommendation X.209 (1988), *Specification of basic encoding rules for Abstract Syntax Notation One (ASN.1).* +- CCITT Recommendation T.511 (to be published), *Implementation requirements for document application profile MM.* + +# **3 Definitions and abbreviations** + +## **3.1 Definitions** + +The definitions defined in Recommendation T.411 are applicable to this DAP. + +## **3.2 Abbreviations** + +DAP Document Application Profile + +# **4 Relationships with other profiles** + +This DAP does not have relationships with other DAPs. + +# **5 Conformance** + +In order to conform to this DAP, a data stream representing a document must meet the requirements specified in 5.1. + +This Recommendation does not define implementation or service requirements. These requirements are defined in other Recommendations that make use of this DAP. + +## **5.1 Data stream conformance** + +The following requirements apply to the encoding of data streams which conform to this DAP. + +- a) The data stream shall be encoded in accordance with the ASN.1 encoding rules defined in Recommendation X.209. +- b) The data stream shall be structured in accordance with the interchange format defined in clause 8. +- c) The document, as represented by the data stream, shall be structured in accordance with the document architecture class as defined in 6.1 and shall contain all mandatory constituents defined for that class; other constituents may be included, provided that they are permitted for that class, as defined in clause 7. +- d) Each constituent shall contain all those attributes defined as required for that constituent in this DAP; other attributes may be specified provided that they are permitted for that constituent. +- e) The attribute values defined shall be within the range or permissible values specified in this DAP. +- f) The encoded document shall be constructed in accordance with the abstract document architecture defined in Recommendation T.412. +- g) The document shall be structured in accordance with the characteristics and constraints defined in clause 6. + +## **5.2 Implementation conformance** + +The implementation requirements associated with this DAP are defined in Recommendation T.511. + +# **6 Characteristics supported by this document application profile** + +This clause describes the characteristics of documents which can be represented by data streams conforming to this DAP. + +## **6.1 Overview** + +This DAP allows documents to be interchanged only in a formatted form which facilitates the reproduction of a document as intended by the originator. + +The generic layout structure allowed in this DAP is a “factor” structure. The purpose of a “factor” generic layout structure allowed in this DAP is to provide for factorization. That is, it provides for predefined attribute values of the object of type block and/or a generic content. + +The form of document may be made up of the following constituents. Constituents defined as “required” must occur in any document that conforms to this DAP. Constituents defined as “optional” may or may not be present in the document depending on the requirements of the particular document. + +- a) *Required constituents:* + - a document profile; + - layout object descriptions representing a specific layout structure: + - layout object description of type document layout root, + - layout object description of type page, + - layout object description of type block. +- b) *Optional constituents:* + - layout object class description representing a “factor” generic layout structure: + - layout object class description of type block; + - content portion description representing a specific layout structure; + - content portion description representing a generic layout structure. + +Either content portion description representing a specific layout structure or content portion description representing a generic layout structure is required. + +When the content portion description in the generic layout structure is present, layout object class description of the type block is required. + +The combinations of constituents allowed in this DAP are illustrated in Figure 1. In this figure document profile is omitted. In the case of b), it provides only for predefined attribute values of the object of type block, for example some presentation attributes. + +## **6.2 Logical characteristics** + +No logical characteristics are applicable in this DAP. + +## **6.3 Layout characteristics** + +This subclause defines the layout constituent constraints provided by this DAP to represent the characteristics of documents. + +### **6.3.1 Overview of the layout characteristics** + +The specific layout structure has 3 hierarchical levels, i.e. a document layout root, pages and blocks. And the generic layout structure has only 1 hierarchical level, i.e. blocks. + +Therefore, a mixed mode document is seen as a sequence of pages. The content of a page may be: + +- a character content; or +- a raster graphics content; or +- both of them. + +When different content types are used within the same page, this page must be composed of several blocks. Each block has a homogeneous content. + +### **6.3.2 Document layout root** + +Document layout root is a required constituent constraint and represents the top level in the specific layout structure. Its immediate subordinates consist of a sequence of one or more constituents of type page. + +![Figure 1/T.501: Allowed combinations of constituents. The figure consists of three diagrams (a, b, c) illustrating the relationship between generic and specific layout structures. Each diagram is divided into two columns: '[Generic layout structure]' on the left and '[Specific layout structure]' on the right. A vertical line separates the two. In all diagrams, the specific structure is a tree where circles represent 'Document layout root', 'Page', and 'Block', and squares represent 'Content portion'. Arrows on the right point to these levels. Diagram (a) shows a generic structure with no elements. Diagram (b) shows a generic structure with one circle (Block) connected to a specific structure's Block node by a dashed arrow. Diagram (c) shows a generic structure with one circle (Block) and one square (Content portion) connected to a specific structure's Block node and its Content portion respectively by dashed arrows. A small code 'T0818510-94/d01' is at the bottom right of diagram (c).](3121ebddccf183ca63bb9781be440a7e_img.jpg) + +**a) In the case of no generic layout structure** + +**b) In the case of presence of generic block** + +**c) In the case of presence of generic block and generic content portion** + +T0818510-94/d01 + +Figure 1/T.501: Allowed combinations of constituents. The figure consists of three diagrams (a, b, c) illustrating the relationship between generic and specific layout structures. Each diagram is divided into two columns: '[Generic layout structure]' on the left and '[Specific layout structure]' on the right. A vertical line separates the two. In all diagrams, the specific structure is a tree where circles represent 'Document layout root', 'Page', and 'Block', and squares represent 'Content portion'. Arrows on the right point to these levels. Diagram (a) shows a generic structure with no elements. Diagram (b) shows a generic structure with one circle (Block) connected to a specific structure's Block node by a dashed arrow. Diagram (c) shows a generic structure with one circle (Block) and one square (Content portion) connected to a specific structure's Block node and its Content portion respectively by dashed arrows. A small code 'T0818510-94/d01' is at the bottom right of diagram (c). + +FIGURE 1/T.501 +Allowed combinations of constituents + +### 6.3.3 Page + +Page is a required constituent constraint in a specific layout structure. Its immediate subordinates consist of a sequence of one or more constituents of type block. + +The page dimensions, which constrain the area made available for the positioning and display of the document content, can take any values (in BMUs) provided that the page size is no longer than ISO A3 nominal page size in portrait orientation. + +Furthermore, when the page size is no longer than the ISO A4 nominal page size in portrait orientation, the corresponding page dimensions are basic values; otherwise, the page dimensions are non-basic values and must be indicated in the document profile. The allowed page dimensions are listed in Table 1. + +The page dimensions are specified using the attribute “dimension” of the layout objects of type page. Any default page dimensions may be specified in the document profile subject to the maximum dimensions defined above. + +TABLE 1/T.501 + +#### **Page dimensions** + +| Page type | Size in inches or millimeters | Nominal size in BMUs | ARA in BMUs | +|-----------------|-------------------------------|----------------------|-----------------| +| ISO A4 | 210 mm × 297 mm | 9 920 × 14 030 | 9 240 × 13 200 | +| ISO A3 | 297 mm × 420 mm | 14 030 × 19 840 | 13 200 × 18 480 | +| ANSI A (NAL) | 8.5 inches × 11 inches | 10 200 × 13 200 | 9 240 × 12 400 | +| Japanese legal | 257 mm × 364 mm | 12 141 × 17 196 | 11 200 × 15 300 | +| Japanese letter | 182 mm × 257 mm | 8 598 × 12 141 | 7 600 × 10 200 | + +### **6.3.4 Block** + +Block is a required constituent constraint in the specific layout structure and an optional constituent constraint in the generic layout structure. + +Block may refer to only one content portion. Each block is positioned in the page and has its own dimensions (independently of the other blocks). + +Within a page, blocks may be positioned in such a way that they intersect partially or fully, i.e. they share common areas. All blocks are “transparent”, which means that the contents of the intersecting area are combined. + +The number of objects of type block per page is restricted. If more than 31 objects of type block are included in one page, the maximum number in a document must be indicated using the attribute “number of objects per page” in the document profile. This number does not contain the number of object class of block. + +Three block layout types are allowed by this DAP. Each block layout specifies how the character content can be presented within a block. These three types are referred to as block layout A, B and C and are illustrated in Figure 2. + +Block layout A is used when the character content is laid out horizontally from left to right or right to left and vertically from top to bottom within the block. This block layout is typically used for documents written in Latin based, Hebrew and Arabic languages. + +Block layout B is used when the character content is laid out vertically from bottom to top or top to bottom and horizontally from left to right within a block. This block layout is typically used for documents written in Latin based, Hebrew and Arabic languages in which it is required to lay out the content in landscape orientation within the block of the page. + +Block layout C is used when the character content is laid out vertically from top to bottom and horizontally from right to left within the block. This block layout is typically used for documents written in languages which use ideograms, such as Japanese and Chinese characters. + +### **6.3.5 Content portion** + +Content portion is an optional constituent constraint in the specific and generic layout structure. However, if a content portion description in the specific layout structure is not present, a content portion description in the generic layout structure is required. This means that when the content portion is not directly associated with the object of type block, then the content must be derived from the content portion associated with the referenced object class of type block. + +## **6.4 Document layout characteristics** + +No document layout characteristics are applicable in this DAP. + +![Figure 2/T.501: Block layout diagrams showing three different orientations of Character Path (CP) and Line Progression (LP) within a block. [Block layout A] shows CP as a horizontal double-headed arrow and LP as a vertical downward arrow. [Block layout B] shows CP as a vertical double-headed arrow and LP as a horizontal rightward arrow. [Block layout C] shows LP as a horizontal leftward arrow and CP as a vertical downward arrow. A legend below defines CP as Character path and LP as Line progression.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +T0818520-94/d02 + +CP Character path +LP Line progression + +Figure 2/T.501: Block layout diagrams showing three different orientations of Character Path (CP) and Line Progression (LP) within a block. [Block layout A] shows CP as a horizontal double-headed arrow and LP as a vertical downward arrow. [Block layout B] shows CP as a vertical double-headed arrow and LP as a horizontal rightward arrow. [Block layout C] shows LP as a horizontal leftward arrow and CP as a vertical downward arrow. A legend below defines CP as Character path and LP as Line progression. + +FIGURE 2/T.501 +**Block layout** + +## 6.5 Content layout and imaging characteristics + +A document may contain character content and raster graphics content. + +### 6.5.1 Character content + +#### 6.5.1.1 Introduction + +This subclause defines the features that are applicable to the character content contained in a document. These features apply to a content associated with a block component, i.e. the object or object class of type block. + +The default values for the following features may be specified in the document profile: + +- graphic character sets; +- graphic character subrepertoire; +- code extension announcers; +- line spacing; +- line progression; +- character spacing; +- character path; +- character orientation; +- graphic rendition, including the parameters: + - normal rendition, bold, italicized, underlined, not bold, not italicized, not underlined; +- initial point. + +The specification in a document of a non-basic feature by a presentation attribute or control function must be indicated in the document profile. + +#### 6.5.1.2 Character content architecture class + +Only the formatted character content architecture class is allowed in a document that conforms to this DAP. This is specified using the attribute “content architecture class”. + +The default content architecture class which specifies formatted character content may be specified in the document profile using the attribute “content architecture class”. + +#### 6.5.1.3 Character repertoire + +The basic character repertoire defined in this DAP is composed of the 94 characters of the IRV of ISO 646 (revised 1990) plus the character space. + +Any other graphic character set which is registered in accordance with ISO 2375 is designated and invoked at any point in the document provided its use is indicated in the document profile as a non-basic value using the character presentation feature “graphic character sets”. No locking shift functions are specified in this presentation feature. + +The code extension techniques allowed for the designation and invocation of character sets to the left hand side and right hand side of the 8-bit code table (GL and GR respectively) are defined in 6.5.1.4. + +Using these code extension techniques, the graphic character sets designated and/or invoked at the beginning of a content portion containing character content are specified by the presentation attribute “graphic character sets”. The graphic character sets can be changed at any point within a content portion. + +The default graphic character sets which apply to the content portions within a document can be specified in the document profile using the presentation attribute “graphic character sets”. + +If the character set defined in ISO 6937-2 is designated and invoked, then the use of any subrepertoire registered according to ISO 7350 is specified using the presentation attribute “graphic character subrepertoire”. All subrepertoires are non-basic and their use must be indicated in the document profile. The subrepertoire shall not be changed within a content portion. + +##### NOTES + +1 The basic character repertoire defined in this DAP is not the standard default value defined in Recommendation T.416; hence it is necessary to specify, in the document profile of a particular document, that this is the default value being used for that document. + +2 Revised Recommendations T.50 and T.51 and new Recommendation T.52 are under preparation. Recommendations T.50 and T.51 are intended to be completely compatible with ISO 646 (revised 1990) and ISO 6937 (under revision), respectively. + +#### 6.5.1.4 Code extension techniques + +The code extension techniques defined in ISO 2022 are used subject to the following restrictions: + +- i) *GO set* – Only the IRV of ISO 646 (revised 1990), the primary set of ISO 6937-2 and a version of ISO 646 can be designated for this set; these character sets may only be invoked in GL. +- ii) *G1, G2, G3 sets* – No restrictions are placed on the character sets that can be designated for these sets; these character sets can only be invoked in GR. +- iii) The locking and single shift functions allowed are as follows: + - LS0 to invoke the G0 set into GL; + - LS1R to invoke the G1 set into GR; + - LS2R to invoke the G2 set into GR; + - LS3R to invoke the G3 set into GR; + - SS2 to invoke one character from the G2 set into GL; + - SS3 to invoke one character from the G3 set into GL. + +(Here GL and GR refer to the left and right hand parts respectively of the 8-bit code table.) + +- iv) When specifying the presentation attribute “graphic character sets”, it is necessary to invoke character sets for both GL and GR. Thus an allowed character set must be designated into G0 [see item i) above] and invoked into GL. It is also necessary to invoke a character set into GR which has been designated into G1, G2 or G3 set. +- v) The empty set must be designated into G1 and invoked into GR if no other specific character set is invoked into GR. + +The code extension techniques allowed are illustrated in Figure 3. + +![Diagram showing code extension features for basic and all possible character sets. Part (a) shows a basic character set with G0, G1, G2, G3 planes and GL, GR planes in the 8-bit code table. Part (b) shows all possible character sets with G0, G1, G2, G3 planes and GL, GR planes in the 8-bit code table, including SS2, SS3, LS1R, LS2R, LS3R, and LS0 planes.](d4af765160d04ecef538e5066006dc77_img.jpg) + +[8-bits code table] + +**a) In the case of basic character set** + +**b) In the case of all possible character sets** + +T0818530-94 + +Diagram showing code extension features for basic and all possible character sets. Part (a) shows a basic character set with G0, G1, G2, G3 planes and GL, GR planes in the 8-bit code table. Part (b) shows all possible character sets with G0, G1, G2, G3 planes and GL, GR planes in the 8-bit code table, including SS2, SS3, LS1R, LS2R, LS3R, and LS0 planes. + +FIGURE 3/T.501 +Code extension features + +The announcement and encoding of these functions are to be as defined in ISO 2022. + +The code extension techniques that are used or may be used in a content are specified by the presentation attribute “code extension announcers”. The default code extension announcers used throughout a document may be specified in the document profile using the presentation attribute “code extension announcers”. + +NOTE – In accordance with Recommendation T.416, there is no restriction concerning the number of graphic character sets which are designated and/or invoked in the presentation attribute “graphic character sets” providing the restrictions defined in this subclause are applied. Hence designation to a particular G set overrides the previous designation to that set, and invocation to GL or GR overrides the previous invocation to GL or GR, respectively. Thus the sequential order of designation and/or invocation sequences in the attribute “graphic character sets” is significant. + +#### **6.5.1.5 Line spacing** + +Line spacing values of 100, 150, 200, 300 and 400 BMUs are specified. The values of 100, 200, 300 and 400 BMUs are basic; the use of the value of 150 BMUs in a document is non-basic and must be indicated in the document profile. + +The line spacing is specified at the beginning of the content using the presentation attribute “line spacing”. The value can be changed anywhere within the content portion using the control function SVS. + +#### **6.5.1.6 Character spacing** + +Character spacing values of 80, 100, 120 and 200 BMUs are specified. The value of 120 BMUs is basic; the use of any other value in a document is non-basic and must be indicated in the document profile. + +The character spacing is specified at the beginning of the content using the presentation attribute “character spacing”. The value can be changed anywhere within the content portion using the control function SHS. + +#### **6.5.1.7 Character path and line progression** + +Both horizontal writing and vertical writing directions can be used within a document. In the case of horizontal writing, the characters progress either from left to right or right to left across the block and line progression is from the top of the block to bottom. In the case of vertical writing, the characters progress from the top of the block to the bottom and line progression is from the right to the left. The use of these writing directions is restricted by the block layout type used. + +For block layout A, only horizontal writing is used. Thus, in this case the character path and line progression is specified either as 0 degree and 270 degrees respectively or 180 degrees and 90 degrees respectively. + +For block layout B, again horizontal writing is used. However, in this case the character content in the block is presented for viewing with the page in landscape orientation. Thus, character path and line progression is specified either as 90 degrees and 270 degrees respectively or 270 degrees and 90 degrees respectively. + +For block layout C, only vertical writing is used. Thus, in this case the character path and line progression is specified as 270 degrees and 270 degrees respectively. + +The character path values of 0 degree and 90 degrees are basic. The character path values of 180 degrees and 270 degrees are non-basic and must be indicated in the document profile. + +The values of character path are specified at the beginning of the content using the presentation attribute “character path”. The value cannot be changed within a content portion. + +The line progression value of 270 degrees is basic. The line progression value of 90 degrees is non-basic and must be indicated in the document profile. + +The value of line progression is specified at the beginning of the content using the presentation attribute “line progression”. The value cannot be changed within a content portion. + +#### **6.5.1.8 Character orientation** + +The character orientation is specified as 0 degree, 90 degrees and 180 degrees depending on the writing direction (see 6.5.1.7). + +When from left to right horizontal writing is used, characters is orientated at 0 degree. When from right to left horizontal writing is used, characters is orientated at 180 degrees. + +When vertical writing is used, characters is orientated at 90 degrees or 0 degree. The character orientation value of 0 degree in the case of vertical writing is typically used when it is required to mix diagram characters with Latin characters. In order to achieve this, character strings orientated at 0 degree and 90 degrees must be defined in separate blocks. + +The character orientation value of 0 is basic. The value of 90 degrees and 180 degrees are non-basic and must be indicated in the document profile. + +The values of character orientation are specified at the beginning of the content using the presentation attribute “character orientation”. The value can not be changed within a content portion. + +The allowed combinations of character path, line progression and character orientation in this DAP are shown in Table 2. + +TABLE 2/T.501 + +##### **Allowed combinations of character path, line progression and character orientation** + +| Block layout type | Character path (degrees) | Line progression (degrees) | Character orientation (degrees) | Remarks | +|-------------------|--------------------------|----------------------------|---------------------------------|----------------------------------------------| +| A | 0 | 270 | 0 | Left to right horizontal writing | +| | 180 | 90 | 180 | Right to left horizontal writing | +| B | 90 | 270 | 0 | Left to right horizontal writing (landscape) | +| | 270 | 90 | 180 | Right to left horizontal writing (landscape) | +| C | 270 | 270 | 90 | Top to bottom vertical writing | +| | 270 | 270 | 0 | Top to bottom vertical writing | + +#### 6.5.1.9 Emphasis + +The following modes of emphasizing graphic characters are specified as basic: + +- normal rendition (cancel); +- bold (increase intensity); +- not bold (normal intensity); +- italicized; +- not italicized; +- underlined; +- not underlined. + +If no default mode is explicitly specified in the document profile, then the default mode is normal rendition. + +The mode of emphasis is specified at the beginning of the content using the presentation attribute “graphic rendition”. The mode can be changed anywhere within the content using the control function SGR. + +The mode of emphasis remains in effect within the content associated with a block component until changed into a mutually exclusive mode or by the specification or “normal rendition”. Mutually exclusive modes are bold/not bold, italicized/not italicized and underlined/not underlined. One mode from each mutually exclusive set can be in operation at any point in the document content. + +Normal rendition cancels the effect of all methods of emphasis that are currently in operation and specifies that the text should be displayed in accordance with the default rendition parameters set for the presentation device. Thus, for example, if it is required to ensure that the content is not underlined, then it is necessary to explicitly specify that underlined is not to be used. + +#### **6.5.1.10 Reverse character string** + +Bidirectional writing is supported by this DAP (see 6.5.1.7). Hence, a string of characters in a content portion associated with a block can be specified to be imaged in the reverse direction of the immediately preceding character string. Such strings are specified by the control function SRS. + +This control function is provided for cases in which the text belongs to different languages and the character content is written, for example, from left to right or from right to left within the same line of characters, dependent upon the language and/or character set being used. + +#### **6.5.1.11 Initial point** + +The initial point which is applicable to a block components is specified by the presentation attribute “initial offset”. Any values are specified as basic. + +#### **6.5.1.12 Superscripts and subscripts** + +Superscripts and subscripts are specified anywhere within the content by using the control functions PLU and PLD. The use of these control functions shall be in accordance with Recommendation T.416. + +#### **6.5.1.13 Substitution of characters** + +The control functions SUB is provided to represent characters produced by a local system that cannot be represented by a character within a character set supported by this DAP. + +#### **6.5.1.14 Use of control functions** + +The following is a list of all the control functions and parameter values (where applicable) that can be specified in character content: + +| | | +|-----|--------------------------------------------------------------------------------| +| SHS | select character spacing<br>(allowed parameter values: 0, 1, 2, 3) | +| SVS | select line spacing<br>(allowed parameter values: 0, 1, 2, 3, 4) | +| SGR | select graphic rendition<br>(allowed parameter values: 0, 1, 3, 4, 22, 23, 24) | +| SRS | set reverse string<br>(allowed parameter values: any) | +| PLD | partial line down | +| PLU | partial line up | +| SUB | substitute character | +| BS | backspace | +| SP | space | +| CR | carriage return | +| LF | line feed | +| | code extension control functions (see 6.5.1.4). | + +### **6.5.2 Raster graphics content** + +#### **6.5.2.1 Introduction** + +This subclause defines the features that are applicable to the raster graphics content contained in a document. These features apply to a content associated with a block component, i.e. the object or object class of type block. + +The default values for the following features may be specified in the document profile: + +- type of coding; +- compression; +- pel density; +- initial point. + +The specification in a document of a non-basic feature by a presentation attribute or coding attributes must be indicated in the document profile. + +#### **6.5.2.2 Raster graphics content architecture class** + +The formatted raster graphics content architecture class is allowed in a document that conforms to this DAP. This is specified using the attribute “content architecture class”. + +The default content architecture class which specifies formatted raster graphics content may be specified in the document profile using the attribute “content architecture class”. + +#### **6.5.2.3 Raster graphics encoding method** + +The raster graphics content must be encoded in accordance with the encoding method scheme defined in Recommendation T.6. The T.6 encoding used is specified as basic by the common coding attribute “type of coding”. This attribute is also used to specify the character encoding. + +The default content architecture class which indicates T.6 encoding or character encoding may be specified in the document profile using the common coding attribute “type of coding”. + +The use of the common coding attribute “type of coding” is non-mandatory. Thus, if this attribute is not specified for a particular content portion and if the content architecture class specified corresponds to the formatted raster graphics content architecture class, then the default encoding method is assumed to be T.6. + +In a content portion, it is required that the coding attribute “number of pels per line” is specified and any value of this attribute is specified. The coding attribute “compression” which specifies “uncompressed” mode of T.6 encoding is specified as a non-basic feature. + +#### **6.5.2.4 Pel density** + +Pel density values of 200, 240, 300, 400, 600 and 1200 pels per 1200 BMUs are specified. The values of 240 and 300 pels per 1200 BMUs are basic; the use of other values in a document is non-basic and must be indicated in the document profile. + +The pel density is specified at the beginning of the content using the presentation attribute “pel transmission density”. The value cannot be changed within a content portion. + +#### **6.5.2.5 Initial point** + +The initial point which is applicable to a block components is specified by the presentation attribute “initial offset”. Any values are specified as basic. + +#### **6.5.2.6 Pel path and line progression** + +The pel path supported by this DAP is 0 degree only which is the standard default value specified in Recommendation T.416. Thus, the pel path may not be specified. + +The line progression supported by this DAP is 270 degrees only which is the standard default value specified in Recommendation T.416. Thus, the line progression may not be specified. + +## **6.6 Miscellaneous features** + +### **6.6.1 Alternative representation** + +The content information in a content portion may be replaced by a string of characters specified in the attribute “alternative representation”. This attribute is specified in content portions. + +The string of characters specified must belong to the character repertoires indicated in the document profile attribute “alternative representation character sets” (see 6.7.4.2). If the latter attribute is not explicitly specified in the document profile, then the default character set is the minimum subrepertoire of ISO 6937-2. The control functions CR and LF are also used within the character string but no other control function is allowed; hence graphic character set cannot be changed in the attributes “alternative representation”. + +## **6.7 Document management features** + +Information relating to the document as a whole is specified in the document profile which is represented by the constituent of type document profile. This constituent must be specified in every document. + +The information in the document profile is classified into the following categories: + +- i) document constituent information; +- ii) document identification information; +- iii) document default information; +- iv) non-basic characteristics information; +- v) document management information. + +The information in the document profile may be of interest to the user or may be used for machine processing of the document. + +### **6.7.1 Document constituent information** + +This information specifies which constituents are used to represent the document. + +#### **6.7.1.1 Presence of document constituents** + +This information indicates which constituents are included in the document. That is, this information indicates whether or not the document contains a generic layout structure and a specific layout structure. It is mandatory to specify this information in the document profile. + +### **6.7.2 Document identification information** + +This information relates to the identification of the document. This information is divided into six categories. + +#### **6.7.2.1 Document application profile information** + +This information indicates the document application profile to which the document belongs. It is mandatory to specify this information using the attribute “document application profile”. + +#### **6.7.2.2 Document architecture class information** + +This information indicates the document architecture class to which the document belongs (see 6.1). It is mandatory to specify this information using the attribute “document architecture class”. + +#### **6.7.2.3 Content architecture class information** + +This information indicates the content architecture class used in the document (see 6.5.1.2 and 6.5.2.2). It is mandatory to specify this information using the attribute “content architecture class”. + +#### 6.7.2.4 Interchange format class information + +This information indicates the interchange format class used to represent the document (see clause 8). It is mandatory to specify this information using the attribute “interchange format class”. + +#### 6.7.2.5 ODA version information + +This information indicates the CCITT Recommendation to which the document conforms. It also specifies a calendar data, which indicates that the document conforms to the version of the CCITT Recommendation and any addenda that are current on that date. It is mandatory to specify this information using the attribute “ODA version”. + +### 6.7.3 Document default information + +This information specifies various default values for attributes used in the document. The default values that are allowed are specified in the various subclauses of clause 6. The specification of this information is only required when it is required to specify a default value which is other than the standard default value specified in the T.410-Series Recommendations. + +Default values for the following groups of attributes can be specified: + +- document architecture attributes; +- character content attributes; +- raster graphics content attributes. + +### 6.7.4 Non-basic characteristics information + +This information specifies the non-basic attribute values specified in the document. It is mandatory to specify a non-basic attribute in the document profile when such a value is used in the document. + +The following types of non-basic attributes can be specified: + +- profile character sets; +- alternative representation character sets; +- page dimensions; +- character presentation features; +- raster graphics presentation features; +- raster graphics coding attributes; +- number of objects per page. + +Further information concerning profile and alternative representation character sets is given below. + +#### 6.7.4.1 Profile character sets + +Some document profile attributes have values consisting of character strings, for example, the attribute “document reference”. The character sets assumed to be designated and invoked at the beginning of these character strings is specified by the document profile attribute “profile character sets”. + +The character sets that are designated and invoked by the attribute “profile character sets” are subject to the following restrictions: + +- i) *GO set* – Only the IRV of ISO 646 (revised 1990), the primary set of ISO 6937-2 and a version of ISO 646 can be designated for this set; these graphic character sets may only be invoked in GL. +- ii) *G1, G2, G3 sets* – No restrictions are placed on the graphic character sets that can be designated for these sets; these graphic character sets can only be invoked in GR. +- iii) The empty set must be designated into G1 and invoked into GR if no further specific character set is invoked into GR. + +If the attribute “profile character sets” is not specified, then the character set designated and invoked is assumed to be the minimum subrepertoire of ISO 6937-2. + +When the Teletex subrepertoire of ISO 6937-2 is needed, the primary set and the supplementary set of Recommendation T.61 is designated and invoked in this attribute. + +#### 6.7.4.2 Alternative representation character sets + +This attribute specifies the graphic character sets designated and invoked at the beginning of the attribute “alternative representation” other than the standard default graphic character sets. + +The restriction on graphic character sets described in 6.7.4.1 is also applied. If this attribute is not explicitly specified in the document profile, the minimum subrepertoire of ISO 6937-2 is used in the attribute “alternative representation”. + +When the Teletex subrepertoire of ISO 6937-2 is needed, the primary set and the supplementary set of Recommendation T.61 is designated and invoked in this attribute. + +### 6.7.5 Document management information + +#### 6.7.5.1 Document reference + +This information serves to identify the document. Typically this information is allocated to the document by the creator of the document. The identifier consists of an ASN.1 object identifier or string of characters. It is mandatory to specify this information using the attribute “document reference”. + +# 7 Specification of constituent constraints + +This clause specifies the definitions of the constituent constraints which can be represented by data streams conforming to this DAP. + +## 7.1 Document profile constraints + +### 7.1.1 Macro definitions + +``` +DEFINE(FC, "ASN.1 { 2 8 2 6 0 }" -- formatted character content --) +DEFINE(FR, "ASN.1 { 2 8 2 7 0 }" -- formatted raster graphics content --) +DEFINE(CE, "ASN.1 { 2 8 3 6 0 }" -- character encoding --) +DEFINE(RE, "ASN.1 { 2 8 3 7 0 }" -- T.6 encoding --) +``` + +``` +DEFINE(BasicPageDimensions, " + { REQ #horizontal-dimension + { REQ #fixed-dimension { <=9920 } }, + REQ #vertical-dimension + { REQ #fixed-dimension { <=14030 } } }") +``` + +-- Any size equal to or smaller than nominal page size of ISO A4. +-- Only portrait may be specified -- + +``` +DEFINE(NonBasicPageDimensions, " + { { REQ #horizontal-dimension + { REQ #fixed-dimension { <= 14030 } }, + REQ #vertical-dimension + { REQ #fixed-dimension { 14031..19840 } } } + | { REQ #horizontal-dimension + { REQ #fixed-dimension { 9921..14030 } }, + REQ #vertical-dimension + { REQ #fixed-dimension { <= 19840 } } } ") +``` + +-- Any size equal to or smaller than nominal page size of ISO A3 +-- and larger than the range of basic value. -- + +``` +DEFINE(PermissiblePageDimensions, "$BasicPageDimensions + $NonBasicPageDimensions") +``` + +-- Macro defining permissible values of graphic renditions. +-- All the values are basic -- + +``` +DEFINE(GRAPHICRENDITIONS, " + { 'cancel' | 'increased-intensity' | 'italicized' + | 'underlined' | 'normal-intensity' | 'not-italicized' + | 'not underlined' } ... ") +``` + +-- Macro defining permissible code extension announcer. +-- All the values are basic -- + +DEFINE(CDEXTAN, " ESC 02/00 05/00, -- Use G0 & LS0 -- +[ ESC 02/00 05/03 ], -- Use G1 & LS1R -- +[ ESC 02/00 05/05 ], -- Use G2 & LS2R -- +[ ESC 02/00 05/07 ], -- Use G3 & LS3R -- +[ ESC 02/00 05/10 ], -- Use G2 & SS2 -- +[ ESC 02/00 05/11 ], -- Use G3 & SS3 --") + +-- Macros defining final character for designation -- + +DEFINE(FCORE, "04/02" -- The 94 characters of the IRV of ISO 646 (revised 1990) +plus the character space (i.e. ASCII) --) + +DEFINE(F646, "-- A final character designating any version of ISO 646 except 04/02 --") + +DEFINE(F94S, "-- A final character designating any registered 94 single byte graphic +character set --") + +DEFINE(F94M, "-- A final character designating any registered 94 multi byte graphic +character set --") + +DEFINE(F96S, "-- A final character designating any registered 96 single byte graphic +character set --") + +DEFINE(F96M, "-- A final character designating any registered 96 multi byte graphic +character set --") + +DEFINE(FEMPTY, "07/14" -- The empty set. --) + +-- Macro defining a revision number of character set -- + +DEFINE(REV, "-- A revision number of character set from 04/00 to 07/14 --") + +-- Macros defining designation sequences -- + +DEFINE(DEG-CORE-G0, "ESC 02/08 \$FCORE") +-- Designate 94 characters of the IRV of ISO 646 to G0 -- + +DEFINE(DEG-646-G0, "ESC 02/08 \$F646") +-- Designate any version of ISO 646, except 04/02, to G0 -- + +DEFINE(DEG-ANY-G1, "{ [ESC 02/06 \$REV], +{ ESC 02/09 \$F94S +| ESC 02/04 02/09 \$F94M +| ESC 02/13 \$F96S +| ESC 02/04 02/13 \$F96M } }") +-- Designate any character set to G1 -- + +DEFINE(DEG-ANY-G2, "{ [ESC 02/06 \$REV], +{ ESC 02/10 \$F94S +| ESC 02/04 02/10 \$F94M +| ESC 02/14 \$F96S +| ESC 02/04 02/14 \$F96M } }") +-- Designate any character set to G2 -- + +DEFINE(DEG-ANY-G3, "{ [ESC 02/06 \$REV], +{ ESC 02/11 \$F94S +| ESC 02/04 02/11 \$F94M +| ESC 02/15 \$F96S +| ESC 02/04 02/15 \$F96M } }") +-- Designate any character set to G3 -- + +DEFINE(DEG-EMPTY-G1, "ESC 02/09 \$FEMPTY") +-- Designate the empty set to G1 -- + +-- Macros defining shift functions -- + +``` +DEFINE(LS0, "00/15") -- Locking shift invoking G0 -> GL -- +DEFINE(LS1R, "ESC 07/14") -- Locking shift invoking G1 -> GR -- +DEFINE(LS2R, "ESC 07/13") -- Locking shift invoking G2 -> GR -- +DEFINE(LS3R, "ESC 07/12") -- Locking shift invoking G3 -> GR -- +DEFINE(SS2, "08/14") -- Single shift invoking G2 -> GL -- +DEFINE(SS3, "08/15") -- Single shift invoking G3 -> GL -- +``` + +-- Macro defining permissible graphic character sets -- + +``` +DEFINE(PERMIT-GRCHAR, "{ $DEG-CORE-G0 $LS0 | $DEG-646-G0 $LS0 } , + { { $DEG-ANY-G1 $LS1R + | $DEG-ANY-G2 $LS2R + | $DEG-ANY-G3 $LS3R } ... + | $DEG-EMPTY-G1 $LS1R } ") +``` + +-- Macro defining basic graphic character sets. Note that this macro +-- is defined for clarifications of the specification and is not to be used in +-- any other part of this DAP specification -- + +``` +DEFINE(BASIC-GRCHAR, "$DEG-CORE-G0 $LS0, $DEG-EMPTY-G1 $LS1R ") +``` + +-- Macro defining non-basic character sets -- + +``` +DEFINE(NON-BASIC-GRCHAR, " { $DEG-646-G0 + | $DEG-ANY-G1 + | $DEG-ANY-G2 + | $DEG-ANY-G3 } ... ") +``` + +-- Macro defining character sets used in document profile attributes -- + +``` +DEFINE(PROFCHAR, "{ $DEG-CORE-G0 $LS0 | $DEG-646-G0 $LS0 } , + { $DEG-ANY-G1 $LS1R + | $DEG-ANY-G2 $LS2R + | $DEG-ANY-G3 $LS3R + | $DEG-EMPTY-G1 $LS1R } ") +``` + +-- Macro defining character sets used for alternative representation -- + +``` +DEFINE(ALTCHAR, " $PROFCHAR") -- Same constraint as PROFCHAR -- +``` + +-- Macro defining character presentation attributes -- + +``` +DEFINE(CharacterPreAttributes, " { + PERM #character-path {'0-degrees' | '90-degrees', + | '180-degrees' | '270-degrees' } , + PERM #character-orientation {'0-degrees' | '90-degrees', + | '180-degrees' } , + PERM #initial-offset { ANY_VALUE } , + PERM #character-spacing { 80 | 100 | 120 | 200 } , + PERM #line-spacing { 100 | 150 | 200 | 300 | 400 } , + PERM #line-progression { '90-degrees' | '270-degrees' } , + PERM #graphic-rendition { $GRAPHICRENDITIONS } , + PERM #graphic-character-subrepertoire, { ANY_VALUE } , + PERM #graphic-character-sets { $PERMIT-GRCHAR } , + PERM #code-extension-announcers { $CDEXTAN } } ") +``` + +-- Macro defining raster graphics presentation attributes -- + +``` +DEFINE(RasterGraphicsPreAttributes, " { + PERM #pel-transmission-density { 'P1' | 'P2' | 'P3' | 'P4' | 'P5' | 'P6' } , + PERM #initial-offset { ANY_VALUE } } ") +``` + +-- Macro defining raster graphics content defaults -- + +``` +DEFINE(RasterGraphicsDefaults, " { + PERM # pel-transmission-density { 'P1' | 'P2' | 'P3' | 'P4' | 'P5' | 'P6' }, + PERM # initial-offset { ANY_VALUE }, + PERM # compression { ANY_VALUE } }") +``` + +### 7.1.2 Constituent constraints + +#### 7.1.2.1 DocumentProfile { + +``` +PERM Generic-layout-structure { 'factor-generator-set' }, +REQ Specific-layout-structure { 'present' }, +``` + +-- Document characteristics -- + +``` +REQ Document-application-profile { ASN.1 { 0 0 20 501 0 } }, +PERM Document-application-profile-defaults { + PERM #content-architecture-class { $FC | $FR }, + PERM #page-dimensions { $PermissiblePageDimensions }, + PERM #type-of-coding { $CE | $RE }, + PERM #character-content-defaults { $CharacterPreAttributes }, + PERM #raster-graphics-content-defaults { $RasterGraphicsDefaults } }, +REQ Document-architecture-class { 'formatted' }, +REQ Content-architecture-classes { [$FC], [$FR] }, +REQ Interchange-format-class { 'if-a' }, +REQ Oda-version { REQ #standard-or-recommendation + { "CCITT Recommendation T.410" }, + REQ #publication-date + { "1992-04-23" }, +``` + +-- Non-basic document characteristics -- + +``` +PERM Profile-character-sets { $PROFCHAR }, +PERM Alternative-representation-character-sets { $ALTCHAR }, +PERM Page-dimensions { PMUL { $NonBasicPageDimensions } }, +PERM Coding-attributes { + PERM #raster-graphics-coding-attributes { + PERM #compression { 'uncompressed' } }, +PERM Presentation-features { + PERM #character-presentation-features { + PERM #character-path { '180-degrees' | '270-degrees' }, + PERM #character-orientation { '90-degrees' | '180-degrees' }, + PMUL #character-spacing { 80 | 100 | 200 }, + PERM #line-spacing { 150 }, + PERM #line-progression { '90-degrees' }, + PMUL #graphic-character-subrepertoire { ANY_VALUE }, + PMUL #graphic-character-sets { $NON-BASIC-GRCHAR }, + PERM #raster-graphics-presentation-features { + PMUL #pel-transmission-density { 'P6' | 'P3' | 'P2' | 'P1' } }, +PERM Number-of-objects-per-page { > 31 }, +``` + +-- Document management attributes -- + +``` +REQ Document-reference { ANY_VALUE } +``` + +## 7.2 Logical constituent constraints + +No logical constituent constraints are applicable in this DAP. + +## 7.3 Layout constituent constraints + +### 7.3.1 Macro definitions + +No macro definitions are applicable in this subclause. + +### 7.3.2 Factor constraints + +No factor constraints are applicable in this subclause. + +### 7.3.3 Constituent constraints + +#### 7.3.3.1 DocumentLayoutRoot { + +SPECIFIC: + +| | | | +|------|-----------------------------|-----------------------------------------| +| REQ | Object-type | { 'document-layout-root' }, | +| REQ | Object-identifier | { ANY_VALUE }, | +| REQ | Subordinates | { SUB_ID_OF (Page) + }, | +| PERM | Default-value-lists | { | +| PERM | #page-attributes | { | +| PERM | Dimensions | { \$PermissiblePageDimensions } }, | +| PERM | #block-attributes | { | +| PERM | Position | { REQ #fixed-position | +| | | { REQ #horizontal-position | +| | | { ANY_INTEGER }, | +| | | REQ #vertical-position | +| | | { ANY_INTEGER } } }, | +| PERM | Dimensions | { REQ #horizontal-dimension | +| | | { REQ #fixed-dimension | +| | | { ANY_INTEGER } }, | +| | | REQ #vertical-dimension | +| | | { REQ #fixed-dimension | +| | | { ANY_INTEGER } } }, | +| PERM | Presentation-attributes | { | +| PERM | #character-attributes | { \$CharacterPreAttributes }, | +| PERM | #raster-graphics-attributes | { \$RasterGraphicsPreAttributes } } } } | + +#### 7.3.3.2 Page { + +SPECIFIC: + +| | | | +|------|-----------------------------|---------------------------------------| +| REQ | Object-type | { 'page' }, | +| REQ | Object-identifier | { ANY_VALUE }, | +| REQ | Subordinates | { SUB_ID_OF (Block) + }, | +| PERM | Dimensions | { \$PermissiblePageDimensions }, | +| PERM | Default-value-lists | { | +| PERM | #block-attributes | { | +| PERM | Position | { REQ #fixed-position | +| | | { REQ #horizontal-position | +| | | { ANY_INTEGER }, | +| | | REQ #vertical-position | +| | | { ANY_INTEGER } } }, | +| PERM | Dimensions | { REQ #horizontal-dimension | +| | | { REQ #fixed-dimension | +| | | { ANY_INTEGER } }, | +| | | REQ #vertical-dimension | +| | | { REQ #fixed-dimension | +| | | { ANY_INTEGER } } }, | +| PERM | Presentation-attributes | { | +| PERM | #character-attributes | { \$CharacterPreAttributes }, | +| PERM | #raster-graphics-attributes | { \$RasterGraphicsPreAttributes } } } | + +#### 7.3.3.3 Block { + +##### GENERIC: + +REQ Object-class-identifier { ANY\_VALUE } + +##### SPECIFIC: + +REQ Object-identifier { ANY\_VALUE }, + +PERM Object-class { OBJECT\_CLASS\_ID\_OF (Block) } + +##### GENERIC\_AND\_SPECIFIC: + +REQ Object-type { 'block' }, + +PERM Content-portions { CONTENT\_ID\_OF +(Character-content-portion) +| CONTENT\_ID\_OF +(Raster-graphics-content-portion) }, + +PERM Position { REQ #fixed-position +{ REQ #horizontal-position +{ ANY\_INTEGER }, +REQ #vertical-position +{ ANY\_INTEGER } } }, + +PERM Dimensions { REQ #horizontal-dimension +{ REQ #fixed-dimension +{ ANY\_INTEGER } }, +REQ #vertical-dimension +{ REQ #fixed-dimension +{ ANY\_INTEGER } } }, + +PERM Content-architecture-class { \$FC | \$FR }, + +PERM Presentation-attributes { +PERM #character-attributes { \$CharacterPreAttributes }, +PERM #raster-graphics-attributes { \$RasterGraphicsPreAttributes } } + +-- The attribute "content portion" must be specified +-- in either object or object class of type block -- + +## 7.4 Layout style constraints + +No layout style constraints are applicable in this DAP. + +## 7.5 Presentation style constraints + +No presentation style constraints are applicable in this DAP. + +## 7.6 Content portion constraints + +### 7.6.1 Macro definitions + +No macro definitions are applicable in this subclause. + +### 7.6.2 Factor constraints + +No factor constraints are applicable in this subclause. + +### 7.6.3 Content portion constraints + +#### 7.6.3.1 Character-content-portion { + +REQ Content-identifier-layout { ANY\_VALUE }, + +PERM Type-of-coding { \$CE }, + +PERM Alternative-representation { ANY\_VALUE }, + +REQ Content-information { CHARACTER, +{ #SHS { 80 | 100 | 120 | 200 } +| #SGR { \$GRAPHICRENDITIONS } +| #SVS { 100 | 150 | 200 | 300 | 400 } +| #SRS { ANY\_VALUE } +| #BS +| #CR + +``` + +| #LF +| #PLD +| #PLU +| #SP +| #SUB +| #SLS0 +| #SLS1R +| #SLS2R +| #SLS3R +| #SSS2 +| #SSS3 +| #SDEG-CORE-G0 +| #SDEG-646-G0 +| #SDEG-ANY-G1 +| #SDEG-ANY-G2 +| #SDEG-ANY-G3 +| #SDEG-EMPTY-G1 } ... } + +``` + +**7.6.3.2 Raster-graphics-content-portion {** + +| | | | +|-------------|-------------------------------------|-------------------------| +| <b>REQ</b> | <b>Content-identifier-layout</b> | <b>{ ANY_VALUE },</b> | +| <b>PERM</b> | <b>Type-of-coding</b> | <b>{ \$RE },</b> | +| <b>REQ</b> | <b>Coding-attributes</b> | <b>{</b> | +| | <b>REQ #number-of-pels-per-line</b> | <b>{ ANY_VALUE },</b> | +| | <b>PERM #compression</b> | <b>{ ANY_VALUE } },</b> | +| <b>PERM</b> | <b>Alternative-representation</b> | <b>{ ANY_VALUE },</b> | +| <b>REQ</b> | <b>Content-information</b> | <b>{ RASTER } }</b> | + +# 8 Interchange format + +Interchange format class ‘‘A’’ is to be used in this DAP, as defined in Recommendation T.415. \ No newline at end of file diff --git a/marked/T/T-REC-T.502-199411-I_PDF-E/raw.md b/marked/T/T-REC-T.502-199411-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..75c95d0054ce2b91a4d07867606a97f94c0ce7eb --- /dev/null +++ b/marked/T/T-REC-T.502-199411-I_PDF-E/raw.md @@ -0,0 +1,2875 @@ + + +![ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol below it.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol below it. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## T.502 + +(11/94) + +# TERMINALS FOR TELEMATIC SERVICES --- + +**DOCUMENT APPLICATION PROFILE PM-11 +FOR THE INTERCHANGE OF SIMPLE +STRUCTURE, CHARACTER CONTENT +DOCUMENTS IN PROCESSABLE AND +FORMATTED FORMS** + +**ITU-T Recommendation T.502** + +(Previously "CCITT Recommendation") + +--- + +# FOREWORD + +The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). + +ITU-T Recommendation T.502 was revised by ITU-T Study Group 8 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 11th of November 1994. + +## --- NOTE + +In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +© ITU 1995 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +# CONTENTS + +| | <i>Page</i> | +|--------------------------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 Normative references ..... | 1 | +| 2.1 Paired Recommendations International Standards equivalent in technical content ..... | 1 | +| 2.2 Additional references ..... | 2 | +| 3 Definitions ..... | 3 | +| 4 Relationship with other Profiles ..... | 3 | +| 5 Conformance ..... | 3 | +| 5.1 Data stream conformance ..... | 4 | +| 5.2 Implementation conformance ..... | 4 | +| 6 Characteristics supported by this document application profile ..... | 4 | +| 6.1 Overview ..... | 4 | +| 6.1.1 General ..... | 4 | +| 6.1.2 Formatted form documents ..... | 4 | +| 6.1.3 Processable form documents ..... | 5 | +| 6.1.4 Formatted processable form documents ..... | 5 | +| 6.2 Logical characteristics ..... | 5 | +| 6.2.1 Introduction ..... | 5 | +| 6.2.2 Overview of the logical structure ..... | 6 | +| 6.2.3 Body part of the logical structure ..... | 6 | +| 6.2.4 Common content part of the logical structure ..... | 6 | +| 6.3 Layout characteristics ..... | 7 | +| 6.3.1 Overview of the layout characteristics ..... | 7 | +| 6.3.2 DocumentLayoutRoot ..... | 9 | +| 6.3.3 PageSet ..... | 9 | +| 6.3.4 Page characteristics ..... | 9 | +| 6.3.5 Body area characteristics ..... | 11 | +| 6.3.6 Header and footer area characteristics ..... | 11 | +| 6.3.7 SpecificBlock ..... | 11 | +| 6.4 Document layout characteristics ..... | 11 | +| 6.4.1 Flow controls ..... | 12 | +| 6.4.2 Layout of the document content ..... | 13 | +| 6.4.3 Layout controls applicable in the absence of a generic layout structure ..... | 13 | +| 6.5 Content layout and imaging characteristics ..... | 14 | +| 6.5.1 Introduction ..... | 14 | +| 6.5.2 Character content architecture class ..... | 15 | +| 6.5.3 Character repertoire ..... | 15 | +| 6.5.4 Code extension techniques ..... | 16 | +| 6.5.5 Line spacing ..... | 16 | +| 6.5.6 Character spacing ..... | 16 | +| 6.5.7 Character path and line progression ..... | 18 | +| 6.5.8 Character orientation ..... | 18 | + +| | <i>Page</i> | +|--------|------------------------------------------------------------| +| 6.5.9 | Emphasis ..... 18 | +| 6.5.10 | Tabulation ..... 19 | +| 6.5.11 | Indentation ..... 19 | +| 6.5.12 | Alignment ..... 19 | +| 6.5.13 | First line format..... 19 | +| 6.5.14 | Widow and orphan sizes ..... 20 | +| 6.5.15 | Reverse character string ..... 20 | +| 6.5.16 | Superscripts and subscripts ..... 20 | +| 6.5.17 | Line breaks..... 20 | +| 6.5.18 | Substitution of characters..... 20 | +| 6.5.19 | Initial point..... 21 | +| 6.5.20 | Use of control functions..... 21 | +| 6.5.21 | Formatting the content ..... 21 | +| 6.6 | Miscellaneous features..... 21 | +| 6.6.1 | Application comments ..... 21 | +| 6.6.2 | Alternative representation ..... 22 | +| 6.6.3 | Page numbering ..... 22 | +| 6.6.4 | User readable comments ..... 23 | +| 6.6.5 | User visible name..... 23 | +| 6.7 | Document management features..... 24 | +| 6.7.1 | Document constituent information..... 24 | +| 6.7.2 | Document identification information..... 24 | +| 6.7.3 | Document default information ..... 25 | +| 6.7.4 | Non-basic characteristics information..... 25 | +| 6.7.5 | Document management attributes..... 26 | +| 7 | Specification of constituent constraints..... 27 | +| 7.1 | Introduction ..... 27 | +| 7.1.1 | Diagrams of relationships of logical constituents ..... 27 | +| 7.1.2 | Diagrams of relationships of layout constituents ..... 28 | +| 7.1.3 | Notation ..... 29 | +| 7.2 | Document profile constituent constraints ..... 30 | +| 7.2.1 | Macro definitions ..... 30 | +| 7.2.2 | Constituent constraints..... 34 | +| 7.3 | Logical constituent constraints ..... 36 | +| 7.3.1 | Macro definitions ..... 36 | +| 7.3.2 | Factor constraints ..... 37 | +| 7.3.3 | Constituent constraints..... 37 | +| 7.4 | Layout constituent constraints ..... 39 | +| 7.4.1 | Macro definitions ..... 39 | +| 7.4.2 | Factor constraints ..... 40 | +| 7.4.3 | Constituent constraints..... 41 | +| 7.5 | Layout style constituent constraints..... 44 | +| 7.5.1 | Macro definitions ..... 44 | +| 7.5.2 | Factor constraints ..... 44 | +| 7.5.3 | Constituent constraints..... 44 | +| 7.6 | Presentation style constituent constraints ..... 45 | +| 7.6.1 | Macro definitions ..... 45 | +| 7.6.2 | Factor constituent constraints..... 45 | +| 7.6.3 | Constituent constraints..... 45 | + +| | <i>Page</i> | +|----------------------------------------------------------|-------------| +| 7.7 Content portion constituent constraints ..... | 46 | +| 7.7.1 Macro definitions ..... | 46 | +| 7.7.2 Factor constraints ..... | 46 | +| 7.7.3 Constituent constraints ..... | 46 | +| 8 Interchange format ..... | 47 | +| 8.1 Interchange format ..... | 47 | +| 8.2 Document application profile object identifier ..... | 48 | +| 8.3 Encoding of application comments ..... | 48 | +| 8.4 Data lengths ..... | 48 | +| Annex A – Amendments and technical corrigenda ..... | 48 | +| A.1 Amendments ..... | 48 | +| A.1.1 Amendments to the base standard ..... | 48 | +| A.1.2 Proposed changes to standards due to defects ..... | 49 | +| A.2 Technical corrigenda ..... | 49 | +| A.2.1 Technical corrigenda to this Recommendation ..... | 49 | +| A.3 Versions of the ODA International Standard ..... | 49 | +| Annex B – Recommended practices ..... | 49 | +| B.1 Transfer methods for ODA ..... | 49 | +| B.1.1 Conveyance of ODA over CCITT X.400-1984 ..... | 49 | +| B.1.2 Conveyance of ODA over FTAM ..... | 50 | +| B.1.3 Conveyance of ODA over DTAM ..... | 50 | +| B.1.4 Conveyance of ODA over flexible disks ..... | 50 | +| Annex C – Bibliography ..... | 50 | + +# **SUMMARY** + +This Recommendation specifies an ODA Document Application Profile (DAP) named PM-11. + +This Profile specifies interchange format for the transfer of structured documents between equipment designed for word or document processing. Such documents contain character content. + +The documents that can be interchanged using this Profile range from memos and letters to simple structured documents. This Profile provides a comprehensive level of features for the transfer of documents between these systems. + +A document structured in accordance with this Profile is represented for interchange by the Open Document Interchange Format (ODIF), as defined in Recommendation T.415. + +# INTRODUCTION + +This Recommendation specifies an ODA Document Application Profile (DAP) named PM-11. The purpose of this Profile is to facilitate the interworking of applications interchanging documents based on ODA, T.410-Series CCITT Recommendations | ISO/IEC 8613. This Profile is suitable for interchanging documents in formatted form, processable form or formatted processable form and has been defined in accordance with CCITT Recommendation T.411 | ISO/IEC 8613-1. The format of this Profile is in accordance with the standardized proforma and notation defined in Annex F of CCITT Recommendation T.411 | ISO/IEC 8613-1. + + + +## **DOCUMENT APPLICATION PROFILE PM-11 FOR THE INTERCHANGE OF SIMPLE STRUCTURE, CHARACTER CONTENT DOCUMENTS IN PROCESSABLE AND FORMATTED FORMS** + +*(revised in 1994)* + +# **1 Scope** + +This Profile specifies interchange format for the transfer of structured documents between equipment designed for word or document processing. Such documents contain character content. + +The documents that can be interchanged using this Profile range from memos and letters to simple structured documents. This Profile provides a comprehensive level of features for the transfer of documents between these systems. + +This Profile allows documents to be interchanged in the following forms: + +- formatted form; +- processable form; +- formatted processable form. + +The architecture levels defined for these three forms have matching functionalities so that the interchange formats of a document are convertible from a processable form to any other form. + +This Profile is independent of the processes carried out in an end system to create, edit or reproduce documents. It is also independent of the means to transfer documents which, for example, may be by means of communication links or storage media. + +A document structured in accordance with this Profile is represented for interchange by the Open Document Interchange Format (ODIF), as defined in Recommendation T.415 | ISO/IEC 8613-5. + +# **2 Normative references** + +The following Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision: all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of currently valid ITU-T Recommendations is regularly published. + +## **2.1 Paired Recommendations | International Standards equivalent in technical content** + +- CCITT Recommendation T.411 (1988), *Open Document Architecture (ODA) and Interchange Format: Introduction and General Principles*. + +ISO 8613-1:1989, *Information processing – Text and office systems – Office Document – Architecture (ODA) and Interchange Format – Part 1: Introduction and General Principles*. +- CCITT Recommendation T.411 Annex F (1991), *Open Document Architecture (ODA) and Interchange Format: Introduction and General Principles – Annex F: Document Application Profile Proforma and Notation*. + +ISO 8613-1 Add. 1: *Information processing – Text and office systems – Office Document Architecture (ODA) and Interchange Format – Part 1: Introduction and General Principles – Addendum 1: Document Application Profile Proforma and Notation*. + +- CCITT Recommendation T.412 (1988), *Open Document Architecture (ODA) and Interchange Format: Document Structures*. +ISO 8613-2:1989, *Information processing – Text and office systems – Office Document Architecture (ODA) and Interchange Format – Part 2: Document Structures*. +- CCITT Recommendation T.414 (1988), *Open Document Architecture (ODA) and Interchange Format: Document Profile*. +ISO 8613-4:1989, *Information processing – Text and office systems – Office Document Architecture (ODA) and Interchange Format – Part 4: Document Profile*. +- CCITT Recommendation T.415 (1988), *Open Document Architecture (ODA) and Interchange Format: Open Document Interchange Format (ODIF)*. +ISO 8613-5:1989, *Information processing – Text and office systems – Office Document Architecture (ODA) and Interchange Format – Part 5: Office Document Interchange Format (ODIF)*. +- CCITT Recommendation T.416 (1988), *Open Document Architecture (ODA) and Interchange Format: Character Content Architecture*. +ISO 8613-6:1989, *Information processing – Text and office systems – Office Document Architecture (ODA) and Interchange Format – Part 6: Character content architectures*. +- CCITT Recommendation X.208 (1988), *Specification of Abstract Syntax Notation One (ASN.1)*. +ISO/IEC 8824:1990, *Information technology – Open Systems Interconnection – Specification of Abstract Syntax Notation One (ASN.1)*. +- CCITT Recommendation X.209 (1988), *Specification of basic encoding rules for Abstract Syntax Notation One (ASN.1)*. +ISO/IEC 8825:1990, *Information technology – Open Systems Interconnection – Specification of Basic Encoding Rules for Abstract Syntax Notation One (ASN.1)*. +- ITU-T Recommendation T.505 (1994), *Document Application Profile PM-26 for the Interchange of Enhanced Structure, Mixed Content Documents in Processable and Formatted Forms*. +ISO/IEC ISP 11181-1:1993, *Information technology – International Standardized Profile FOD26 – Open Document Format: Enhanced document structure – Character, raster graphics and geometric graphics content architectures – Part 1: Document Application Profile (DAP)*. +- ITU-T Recommendation T.506 (1993), *Document Application Profile PM-36 for the Interchange of Extended Structure, Mixed Content Documents in Processable and Formatted Forms*. +ISO/IEC ISP 11182-1:1993, *Information technology – International Standardized Profile FOD36 – Open Document Format: Extended document structure – Character, raster graphics and geometric graphics content architectures – Part 1: Document Application Profile (DAP)*. +- CCITT Recommendation T.50 (1992), *International Reference Alphabet (IRA). Information technology – 7-bit coded character set for information interchange*. +ISO/IEC 646:1991, *Information technology – ISO 7-bit coded character set for information interchange*. +- CCITT Recommendation T.51 (1992), *Latin Based Coded Character Sets for Telematic Services*. +ISO/IEC 6937:1994, *Information technology – Coded graphic character set for the communication of texts using the Latin alphabet*. + +## 2.2 Additional references + +- ISO 2022:1986, *Information processing – ISO 7-bit and 8-bit coded character sets – Code extension techniques*. +- ISO 2375:1985, *Data processing – Procedure for registration of escape sequences*. +- ISO/IEC 7350:1991, *Information technology – Registration of repertoires of graphic characters from ISO/IEC 10367*. + +- ISO 8859-1:1987, *Information processing – 8-bit single-byte coded graphic character sets – Part 1: Latin Alphabet No. 1.* +- ISO 9293:1987, *Information processing – Volume and file structure of flexible disk cartridges for information interchange.* +- ISO/IEC TR 10000-1:1992, *Information technology – Framework and taxonomy of International Standardized Profiles – Part 1 : Framework.* +- ISO/IEC TR 10000-2:1992, *Information technology – Framework and taxonomy of International Standardized Profiles – Part 2: Taxonomy of OSI Profiles.* +- CCITT Recommendation T.400 (1988), *Introduction to Document Architecture, Transfer and Manipulation.* +- ISO/IEC ISP 10610-1:1993, *Information technology – International Standardized Profile FOD11 – Open Document Format: Simple document structure – Character content architecture only.* + +# 3 Definitions + +For the purposes of this Profile, the following definitions apply. + +The definitions given in CCITT Rec. T.411 | ISO 8613-1 are applicable to this Profile. + +**constituent constraint names:** Each constituent that may be included in a document that conforms to this Profile has been given a unique name which serves to associate that constituent with a constituent constraint defined in this Profile. + +The convention is that full names are used (i.e. no abbreviations are used), two or more words in a name are concatenated and each word begins with a capital. Examples of constituent constraint names used in this Profile are BodyText and RectoPage. + +In clause 6, each constituent constraint provided by this Profile is italicized once at the point in the text at which the purpose of that constituent constraint is defined. This also serves to identify all the constituent constraints provided by this Profile. + +The same constituent constraint names are also used in the technical specification in clause 7 so that there is a one-to-one correspondence between the use of these names in clauses 6 and 7. + +Although the constituent constraint names relate to the purpose of the constituent constraints, the semantics of constituents shall not be implied from the names that are used. Also, these names do not appear in an interchanged document but a mechanism for associating constituents in a document with constituent constraints is provided (see 6.6.1). Thus, in an application using this Profile, the constituents may be known to the user by different names. + +# 4 Relationship with other Profiles + +This Profile belongs to a series of hierarchically related Profiles which include PM-26 and PM-36. + +The features supported by this Profile are a subset of the features supported by the Profiles PM-26 and PM-36 and thus, all data streams conformant to this Profile are also conformant to PM-26 and PM-36, apart from the document application profile identifier. + +NOTE – This Profile is technically aligned with (but not identical to) the Specification defined in the ISO International Standardized Profile FOD11, except that FOD11 not only defines the use of the ODIF interchange format, but also the use of the SDIF interchange format. + +# 5 Conformance + +In order to conform to this Profile, a data stream representing a document shall meet the requirements specified in 5.1. + +This Recommendation does not define implementation or service requirements. + +## 5.1 Data stream conformance + +The following requirements apply to the encoding of data streams which conform to this Profile: + +- a) the data stream shall be encoded either in accordance with the ASN.1 encoding rules defined in CCITT Rec. X.209 | ISO/IEC 8825; +- b) the data stream shall be structured in accordance with the interchange formats defined in clause 8; +- c) the document, as represented by the data stream after resolution of any external references, shall be structured in accordance with one of the documents architecture classes as defined in 6.1 and shall contain all mandatory constituents specified for that class; other constituents may be included, provided that they are permitted for that class, as specified in clause 7; +- d) each constituent shall contain all those attributes specified as required for that constituent in this Profile; other attributes may be specified provided that they are permitted for that constituent; +- e) the attribute values specified shall be within the range of permissible values specified in this Profile; +- f) the encoded document shall be constructed in accordance with the abstract document architecture defined in CCITT Rec. T.412 | ISO 8613-2; +- g) the document shall be structured in accordance with the characteristics and constraints specified in clause 6. + +## 5.2 Implementation conformance + +This subclause states the requirements for implementations claiming conformance to this Profile. + +A conforming receiving implementation shall be capable of receiving either any data streams conforming to this Profile structured in accordance with ODIF. Receiving usually, but not always, involves recognizing and further processing the data stream elements. + +# 6 Characteristics supported by this document application profile + +This clause describes the characteristics of documents which may be represented by data streams conforming to this Profile. This clause also describes how these characteristics are represented in term of constituent constraints. + +## 6.1 Overview + +### 6.1.1 General + +This Profile supports the interchange of documents in the following forms: + +- processable form, which facilitates the revision of a document by a recipient; +- formatted form, which facilitates the reproduction of a document as intended by the originator; +- formatted processable form, which facilitates the reproduction of a document as intended by the originator or facilitates the revision of a document by a recipient. + +The constituents that make up these three classes of data stream are defined in 6.1.2, 6.1.3 and 6.1.4. Constituents defined as “required” shall occur in any data stream that conforms to this Profile. Constituents listed as “optional” may or may not be present in the data stream depending on the requirements of the particular data stream. + +### 6.1.2 Formatted form documents + +*Required constituents:* + +- a document profile; +- layout object descriptions representing a specific layout structure; +- content portion descriptions associated to the basic objects in the specific layout structure. + +*Optional constituents:* + +- layout object class descriptions representing a factor generic layout structure; +- presentation styles. + +### **6.1.3 Processable form documents** + +*Required constituents:* + +- a document profile; +- logical object class descriptions representing a complete or partial generic logical structure; +- logical object descriptions representing a specific logical structure; +- content portion descriptions associated to the basic objects in the specific logical structure. + +*Optional constituents:* + +- layout object class descriptions representing a complete generic layout structure; +- layout styles; +- presentation styles; +- content portion descriptions associated to the basic object classes in the generic logical structure. + +In the case of processable form documents, when the generic layout structure is not present, additional restrictions are placed on the layout directives that may be included in layout styles. These restrictions are defined in 6.4.3. + +Note that when the generic layout structure is present, a layout style is required by the constituent constraint of the type Passage. + +### **6.1.4 Formatted processable form documents** + +*Required constituents:* + +- a document profile; +- logical object class descriptions representing a complete or partial generic logical structure; +- logical object descriptions representing a specific logical structure; +- layout object class descriptions representing a complete generic layout structure; +- layout object descriptions representing a specific layout structure; +- content portion descriptions associated to the basic objects in the specific logical/layout structure; +- layout styles. + +*Optional constituents:* + +- presentation styles; +- content portion descriptions associated to the basic object classes generic logical structure. + +## **6.2 Logical characteristics** + +### **6.2.1 Introduction** + +This subclause defines the logical constituent constraints provided by this Profile to represent the characteristics of documents containing logical component descriptions. + +Different constituent constraints may be used to represent and distinguish parts of a document that have different logical characteristics. This subclause describes the general characteristics and typical uses of the constituent constraints that are provided. + +The descriptions of the logical characteristics represented by each of the constituent constraints are provided for guidance only. It is the responsibility of the user to determine how a document is to be represented using the constituents provided. Adherence to these guidelines can enhance the mutual understanding of a document by an originator and a recipient. + +### **6.2.2 Overview of the logical structure** + +From the logical point of view, the document consists of two parts, namely a body part and a common part. + +The body part represents the main content of a document and is intended to be reproduced in the body area of the pages that make up the document. The body part shall be included in all documents that are interchanged in accordance with this Profile. + +The common part represents common content that is to be placed in reserved header and footer areas on each page of a document. Header and footer content are independently optional and so may be included in an interchanged document only if required. + +### **6.2.3 Body part of the logical structure** + +#### **6.2.3.1 DocumentLogicalRoot** + +*DocumentLogicalRoot* is a constituent constraint representing the top level in the document logical structure. Its immediate subordinates consist of a sequence of one or more constituent constraints of the type *Passage*. + +#### **6.2.3.2 Passage** + +*Passage* is a constituent constraint that represents the first level of logical subdivision of a document. It may be used to indicate a logical grouping of subordinate parts of a document that are to be regarded as an entity for reading or that have common layout and presentation characteristics. + +Passages are typically used to represent: + +- the contents to be placed on the title page of a report; +- the front matter in the table of contents or foreword; +- the main matter of the document; +- the back matter, consisting of appendices, glossary or index. + +The immediate subordinates of a *Passage* consist of a sequence of one or more constituent constraints of the type *BodyText*. + +A document contains only one class definition of the type *Passage*, which defines the common characteristics of sets of *Passages* within the document such as layout properties. For example, when the generic layout structure is present, *Passage* shall be entirely laid out in the pages of one page set. + +#### **6.2.3.3 BodyText** + +*BodyText* is a constituent constraint which represents the lowest level of logical subdivision of a document. This constituent constraint is a subdivision of *Passages*. This allows the layout and presentation requirements of different parts of the document to be specified. + +This is a basic logical constituent that directly refers to content portions that contain character content. *BodyText* in the specific logical structure shall refer to one or more content portions each containing processable, formatted or formatted processable character content. However, this constituent in the generic logical structure shall not refer to generic content. + +### **6.2.4 Common content part of the logical structure** + +#### **6.2.4.1 CommonContent** + +*CommonContent* is a constituent constraint that represents common content that is to be laid out in the header and footer areas of the pages of a document. Common content consists of character content. + +Any number of constituent constraints of the type `CommonContent` may be contained in a document. `CommonContent` is a composite logical object class whose immediate subordinates consist of an arbitrary ordered sequence of one or more of the following constituent constraints: + +- `CommonText`; +- `PageNumber`. + +When the generic layout structure is present, constituents of the type `CommonContent` and their associated subordinate constituents are constrained to be laid out in frames representing header or footer areas using the “logical source” mechanism (see 6.3.6). + +#### **6.2.4.2 CommonText** + +*CommonText* is a constituent constraint that represents the common character content that is to be laid out in the header or footer area of a document. For example, header or footer content that appears on each page in a sequence of pages may be represented by this constituent. + +`CommonText` is a constituent constraint for a basic logical object class that references one content portion containing processable, formatted or formatted processable character content. + +#### **6.2.4.3 PageNumber** + +*PageNumber* is a constituent constraint that represents the common character content that is to be laid out in the header or footer area of a document. This constituent is specifically used when it is required to present a header or footer content which contains an automatically generated page number. + +`PageNumber` is a basic logical object class that contains a content generator. This content generator contains a reference to a page number which is automatically evaluated when the document is laid out. This provides the means of representing the page numbers that are displayed on the consecutive pages of a document. + +Each page number consists of a single number which may be represented in the form of Arabic or Roman numerals or in its alphabetic equivalent. Page numbering schemes may start at 0 or any value greater than 0 at the document root or page set level. + +The format of the content generators is defined in 6.6.3. + +## **6.3 Layout characteristics** + +This subclause defines the constituent constraints for layout components which are provided by this Profile to represent the characteristics of documents. + +Different constituent constraints may be used to represent and distinguish parts of a document that have different layout characteristics. This subclause describes the general characteristics and typical uses of the constituent constraints that are provided. + +The descriptions of the layout characteristics represented by each of the constituent constraints are provided for guidance only. It is the responsibility of the user to determine how a document is to be represented using the constituents provided. Adherence to these guidelines can enhance the mutual understanding of a document by an originator and a recipient. + +### **6.3.1 Overview of the layout characteristics** + +The document structure allows the document content to be laid out and presented in one or more page sets. Each page set may be used for different parts of the document, for example, the title page, foreword, table of contents, document body and appendices. + +Each page set consists of a series of pages. In general, each page may be subdivided into three areas; the body area, which is used to layout the document body; and the header and footer areas, which may be used to layout the common content. + +Page layout type supported by this Profile is used when the character content is to be laid out horizontally (from left to right or from right to left) and from top to bottom within the body area, the header area and footer area. Portrait and landscape orientations of this page layout are illustrated in Figures 1 and 2 respectively. + +![Diagram of page layout in portrait orientation showing nested areas and paths.](fa859e4e468bfb2710a94527f2c504af_img.jpg) + +The diagram illustrates the layout of a page in portrait orientation. It shows a large outer rectangle labeled "Page" with a "Page offset" indicated at the top-left corner. Inside this is a "Nominal page size" rectangle, which contains "Page dimensions" indicated by arrows. The page is divided into three horizontal sections: "Header area", "Body area", and "Footer area". Each section contains a "Layout path" indicated by a downward arrow and a "CP" (Character path) indicated by a horizontal double-headed arrow, with "LP" (Line progression) indicated by a downward arrow from the CP. + +T0810550/d01 + +Diagram of page layout in portrait orientation showing nested areas and paths. + +CP Character path +LP Line progression + +FIGURE 1/T.502 +**Page layout (portrait orientation)** + +![Diagram of page layout in landscape orientation showing nested areas and paths.](1a827b10290f33d4fec04d0e8ef7a897_img.jpg) + +The diagram illustrates the layout of a page in landscape orientation. It shows a large outer rectangle labeled "Page" with a "Page offset" indicated at the top-left corner. Inside this is a "Nominal page size" rectangle, which contains "Page dimensions" indicated by arrows. The page is divided into three horizontal sections: "Header area", "Body area", and "Footer area". Each section contains a "Layout path" indicated by a downward arrow and a "CP" (Character path) indicated by a horizontal double-headed arrow, with "LP" (Line progression) indicated by a downward arrow from the CP. + +T0810560-92/d02 + +Diagram of page layout in landscape orientation showing nested areas and paths. + +CP Character path +LP Line progression + +FIGURE 2/T.502 +**Page layout (landscape orientation)** + +### 6.3.2 DocumentLayoutRoot + +*DocumentLayoutRoot* is a constituent constraint represents the top level in the document layout structure. Its immediate subordinates consist of a sequence of one or more constituent constraints of the type *PageSet*. The numbering schemes for pages may be initialized on this constituent constraint. + +### 6.3.3 PageSet + +*PageSet* is a constituent constraint that represents a grouping of pages within a document. A *PageSet* is typically used to represent a part of a document that has different layout requirements from other parts of a document. Also, a *PageSet* may correspond to a part of a document that has a certain logical significance, for example, a *PageSet* might represent the front matter in a document or an individual chapter. + +Only one level of *PageSet* is allowed in a document. However, a document may contain any number of class definitions of type *PageSet* which may be used, for example, to provide a choice of alternative layouts for different parts of a document or to specify the exact layout requirements for each successive part of a document. + +The immediate subordinates of a *PageSet* consist of a combination of constituent constraints of the types *Page*, *RectoPage* and *VersoPage* as described in 6.3.4.1. + +### 6.3.4 Page characteristics + +#### 6.3.4.1 Page constituents + +Three constituent constraints are provided to represent the pages within a document, namely *Page*, *RectoPage* and *VersoPage*. + +The only difference in the characteristics of these types of constituent constraints concerns the values that may be specified for the parameter “side of sheet” in the attribute “medium type”. In the case of *Page*, the value of this parameter may be specified as 'recto', 'verso' or 'unspecified'. In the case of *RectoPage*, the value of this parameter may be specified as 'recto' or 'unspecified'. In the case of *VersoPage*, the value of this parameter may be specified as 'verso' or 'unspecified'. The values 'recto' and 'verso' of the “side of sheet” parameter of the “medium type” attribute are non-basic. + +The pages that make up a page set consist of an optional initial page which is represented by the constituent constraint *Page* and which is optionally followed by either: + +- a) A sequence of pages represented by the constituent constraint *Page*. All pages in this sequence shall have the same layout characteristics but these characteristics may differ from those of the initial page. +- b) A sequence of pages which are intended to be laid out alternatively on the 'recto' and 'verso' (or on the 'verso' and 'recto') sides of the presentation medium and are represented by the constituent constraints *RectoPage* and *VersoPage* respectively. All pages in this sequence shall have the same layout characteristics but these characteristics may differ from those of the initial page. + +Pages having the same layout characteristics are pages that have the same page layout (see 6.3.4.5) and for which the body area, header area (if present) and footer area (if present) have the same dimensions and positions within the page (see 6.3.4.3). Pages having the same layout characteristics do not necessarily have the same position on the presentation medium (see 6.3.4.4). + +A page set shall contain at least one page. + +An initial page is typically used at the beginning of a document or of a section within a document. It may be used, for example, for a title page whose layout requirements differ from the following pages. + +The following restrictions also apply to the pages within a page set: + +- all the pages must have the same dimensions and orientation (see 6.3.4.2); +- all pages are to be laid out on the same size of presentation medium (see 6.3.4.3). + +#### 6.3.4.2 Page dimensions + +The dimensions of the pages may be specified as any value (in BMUs) that is equivalent to or less than ISO A3 or ANSI B paper sizes in portrait or landscape orientation. The dimensions may be specified in portrait or landscape orientation. Japanese page sizes B4 and B5 are also supported but the dimensions of these pages lie within the range of dimensions given above. + +Dimensions equivalent to or less than the common assured reproduction area of ISO A4 and ANSI A in portrait or landscape orientation are basic values. Larger page sizes are non-basic and their use shall be indicated in the document profile. + +Any default page dimensions may be specified in the document profile subject to the maximum dimensions defined above. + +NOTE – The size termed “North American Letter (NAL)” in CCITT Rec. T.410-Series | ISO 8613 (e.g. in CCITT Rec. T.412 | ISO 8613-2, clause 7) is in this Specification called “ANSI A” in order to be consistent with the other reference to ANSI standard paper sizes. + +#### 6.3.4.3 Nominal Page sizes + +The nominal page sizes that may be specified are listed in Table 1. These may be specified in portrait or landscape orientation. All values of nominal page size are non-basic and hence all values used in a document must be indicated in the document profile. + +Any value of nominal page size defined in Table 1, subject to the restrictions specified above, may be specified as the default value in the document profile. + +Table 1 also includes the recommended assured reproduction area (ARA). Information loss may occur when a document is reproduced if the dimensions of constituent constraints of the type page exceed the ARA for the specified nominal page size. + +TABLE 1/T.502 +Nominal page sizes + +| Page type | Size in inches<br>or millimetres | Size in BMUs | ARA in BMUs | +|-----------------|----------------------------------|-----------------|-----------------| +| ISO A5 | 148 mm × 210 mm | 7 015 × 9 920 | Not defined | +| ISO A4 | 210 mm × 297 mm | 9 920 × 14 030 | 9 240 × 13 200 | +| ISO A3 | 297 mm × 420 mm | 14 030 × 19 840 | 13 200 × 18 480 | +| ANSI legal | 8.5 × 14 inches | 10 200 × 16 800 | 9 240 × 15 480 | +| ANSI A | 8.5 × 11 inches | 10 200 × 13 200 | 9 240 × 12 400 | +| ANSI B | 11 × 17 inches | 13 200 × 20 400 | 12 744 × 19 656 | +| Japanese legal | 257 mm × 364 mm | 12 141 × 17 196 | 11 200 × 15 300 | +| Japanese letter | 182 mm × 257 mm | 8 598 × 12 141 | 7 600 × 10 200 | + +#### 6.3.4.4 Page offset + +The page offset is the distance of the position of the left and top edges of the page relative to the left and top edges respectively of the presentation medium on which each page is reproduced. Any value of page offset may be specified provided that no part of the page area lies outside the area of the nominal page. Also, page offsets specified for the initial, recto and verso pages within a given page set may differ. The default page offset may be specified in the document profile. + +#### 6.3.4.5 Page layout characteristics + +Each page in a document may be subdivided into three rectangular areas, as follows: + +- a body area which is reserved for content that belongs to the body part of the document (see 6.3.5); +- a header area which is reserved for common header content (see 6.3.6); +- a footer area which is reserved for common footer content (see 6.3.6). + +The body area is mandatory and shall occur on every page in a document. The header and footer areas are both optional. + +Also, these three areas shall be entirely contained within the page area and shall not overlap. + +For the style of page layout supported by this Profile, the header and footer areas are placed above and below the body area respectively. The layout paths in the header, body, and footer area always have a value of 270 degrees, as shown in Figures 1 and 2. As this Profile only supports a layout path of 270 degrees, which is the standard default value specified in CCITT Rec. T.412 | ISO 8613-2, the layout path shall not be explicitly specified in a document. + +### **6.3.5 Body area characteristics** + +#### **6.3.5.1 General characteristics** + +The body area is the area within a page where the main matter of the document, that is the body part of the document, is laid out. + +The body area consists of a single frame into which the content is directly laid out. This body area is represented by a BasicBody frame. + +#### **6.3.5.2 BasicBody** + +*BasicBody* is a constituent constraint which defines a lowest level frame into which the content is directly laid out. + +The position and dimensions of this frame are fixed. The layout path of BasicBody is implicitly specified as 270 degrees (see 6.3.4.5). + +### **6.3.6 Header and footer area characteristics** + +#### **6.3.6.1 General characteristics** + +The header area consists of a basic area and the footer area consists of a basic area. + +A basic header or footer area is an area into which the content is directly laid out. This type of area is represented by a constituent constraint of the type BasicHeader or BasicFooter respectively. + +The content allocated to these areas is derived from the common part of the logical structure of a document. + +#### **6.3.6.2 BasicHeader and BasicFooter** + +*BasicHeader* and *BasicFooter* are constituent constraints that define lowest level frames that represent areas within a page that are reserved for common content. + +These types of frame have fixed positions and dimensions. The layout path of these frames is implicitly specified as 270 degrees (see 6.3.4.5). + +The content that is laid out in these frames is derived, using the logical source mechanism, from the content associated with the composite logical object classes of the type CommonContent. + +### **6.3.7 SpecificBlock** + +*SpecificBlock* is a constituent constraint that defines a specific block. + +Objects of the type SpecificBlock may only occur in the specific layout structure. They are created during the document layout process and result from the layout of basic logical objects into lowest level frames that constitute the body, header and footer areas. + +Each SpecificBlock in a BasicBody frame shall refer to one content portion. A SpecificBlock in a BasicHeader frame or BasicFooter frame may refer to one or more content portions. + +## **6.4 Document layout characteristics** + +Mechanisms for controlling the allocation of logical constituents to various areas in the layout structure are defined in 6.4.1. Mechanisms for controlling the layout of the content within the allocated areas are defined in 6.4.2. + + + +##### **6.4.1.4.1 Concatenation** + +Concatenation provides the means to specify that the content associated with a logical object derived from a basic logical constituent constraint and the content associated with the logical object derived from the previous basic logical constituent constraint are to be regarded as an unbroken stream of content. This may be specified for basic logical constituent constraints of the type CommonText and PageNumber. The attribute “concatenation” is used to specify this feature. + +### **6.4.2 Layout of the document content** + +Various constraints may be specified to control the layout of the content into the body, header and footer areas. These constraints are described below. + +#### **6.4.2.1 Margins** + +The margins are the minimum distances, or offsets, between a part of the document content and the edge of the particular area in which that content is laid out. The margins define the maximum extents of the available area into which the content shall be positioned. + +Margins may be specified for the basic logical constituent constraints of the type BodyText, CommonText and PageNumber; different margin values may be specified for different basic logical constituent constraints without restriction. + +Four margins may be independently specified for each logical constituent constraint (see Figure 3), namely: + +- trailing edge margin; +- leading edge margin; +- right hand edge margin; +- left hand edge margin. + +Any combination of the above margins may be specified for a particular logical constituent constraint. These margins are specified by the attribute “offset”. Any value may be specified in units of BMUs. If a particular margin is not specified then it is assumed to be 0 BMUs. + +#### **6.4.2.2 Separation** + +Leading separation is the minimum distance between one basic logical object and the next one, if any, when they are laid out. Trailing separation is the minimum distance between one basic logical object and the previous one, if any, when they are laid out. Both may be specified for basic logical components of the constituent constraint types BodyText, CommonText and PageNumber. These distances are specified in BMUs by the attribute “separation”. If no value is specified, then the minimum distance is assumed to be 0 BMUs. + +### **6.4.3 Layout controls applicable in the absence of a generic layout structure** + +In processable form documents the generic layout structure is optional. If the generic layout structure is omitted, then it is the responsibility of the receiver to define an appropriate layout structure. No limitations are placed on the layout structure that is used. + +When a generic layout structure is not specified within a processable form document, then restrictions are placed on the layout control functions described in 6.4.1 and 6.4.2 that may be specified within the document. These restrictions are indicated below: + +- It is not possible to specify that certain logical parts of a document are to be allocated to a given page set as defined in 6.4.1.1. +- It is possible to specify page break as defined in 6.4.1.2.1 but it is only possible to indicate that the layout should begin on a new page. It is not possible to specify a particular page class. + +- The logical parts of the document that are intended to be laid out in the body area and in the header/footer areas of each page may be distinguished from each other by means of application comments specified for them (see 6.6.1). An exception is that it is not possible to distinguish whether a particular portion of the common content is to be placed in a header or a footer area (or both). +- Margins and separation as defined in 6.4.2 may all be specified. Indivisibility as defined in 6.4.1.2.2 and same layout object as defined in 6.4.1.2.3 may all be specified. Concatenation as defined in 6.4.1.4.1 may all be specified. + +![Diagram illustrating the specification of margins for a layout frame. It shows a solid rectangle representing the 'Lowest level frame' and a dashed rectangle inside it representing the 'Area available for laying the content'. A 'Layout path' arrow points downwards along the left side of the dashed frame. Margins are indicated by arrows: 'Trailing edge margin' at the top, 'Leading edge margin' at the bottom, 'Right hand edge margin' on the left, and 'Left hand edge margin' on the right. The identifier 'T0804900-90/d03' is located at the bottom right of the diagram.](08a978a124d3ed6cf1a3d0cfd89418d0_img.jpg) + +Diagram illustrating the specification of margins for a layout frame. It shows a solid rectangle representing the 'Lowest level frame' and a dashed rectangle inside it representing the 'Area available for laying the content'. A 'Layout path' arrow points downwards along the left side of the dashed frame. Margins are indicated by arrows: 'Trailing edge margin' at the top, 'Leading edge margin' at the bottom, 'Right hand edge margin' on the left, and 'Left hand edge margin' on the right. The identifier 'T0804900-90/d03' is located at the bottom right of the diagram. + +FIGURE 3/T.502 +Specification of margins + +## 6.5 Content layout and imaging characteristics + +A document contains character content. + +The content architectures that may be specified using the attribute “content architecture class” are formatted character, processable character and formatted processable character. Any of these may be specified as the default in the document profile. + +### 6.5.1 Introduction + +This subclause defines the features that are applicable to the character content contained in a document and the presentation attributes and control functions that may be used to specify these features. These features may apply to basic logical and layout components unless otherwise indicated. + +The default values for the following features may be specified in the document profile: + +- graphic character sets; +- graphic character subrepertoire; +- code extension announcers; +- line spacing; +- character spacing; +- character path; +- line progression; +- graphic rendition, including the parameter values: + - default rendition, increased intensity (bold), italicized, underlined, crossed-out, normal intensity, not italicized, not underlined, not crossed-out; +- line layout table; +- indentation; +- alignment; +- first line offset; +- itemization; +- widow size; +- orphan size; +- initial offset. + +The specification in a document of a non-basic feature by a presentation attribute or control function shall be indicated in the document profile. + +### **6.5.2 Character content architecture class** + +Processable and formatted processable form documents may contain processable, formatted or formatted processable character content. Formatted form documents may contain formatted or formatted processable character content. + +### **6.5.3 Character repertoire** + +The basic character repertoire supported by this Profile is composed of the 94 characters of ISO-IR 6 (the IRV of ISO/IEC 646) plus the character space. + +Any other graphic character set which is registered in accordance with ISO 2375 may be designated and invoked at any point in the document provided its use is indicated in the document profile as a non-basic value using the character presentation feature “graphic character sets”. No locking shift functions are specified in this presentation feature. + +The code extension techniques allowed for the designation and invocation of character sets to the left hand side and right hand side of the 8-bit code table (GL and GR respectively) are defined in 6.5.4. + +Using these code extension techniques, the graphic character sets designated and/or invoked at the beginning of a content portion containing character content are specified by the presentation attribute “graphic character sets”. The graphic character sets may be changed at any point within a content portion. + +The default graphic character sets which apply to the content portions within a document may be specified in the document profile using the presentation attribute “graphic character sets”. + +If the character set defined in ISO 6937 is designated and invoked, then the use of any of its subrepertoires registered according to ISO/IEC 7350 may be specified using the presentation attribute “graphic character subrepertoire”. All subrepertoires are non-basic and their use must be indicated in the document profile. The subrepertoire shall not be changed within a content portion. + +NOTE – The basic character repertoire supported by this Profile is not the standard default value specified in CCITT Rec. T.416 | ISO 8613-6; hence it may be necessary to specify, in the document profile of a particular document, that this is the default value being used for that document. + +### 6.5.4 Code extension techniques + +The code extension techniques specified in ISO 2022 may be used subject to the following restrictions: + +- a) G0 set – Only ISO-IR 6 (the IRV of ISO/IEC 646), ISO-IR 2 (the primary set of ISO 6937-2), or any other version of ISO 646 may be designated for this set; these graphic character sets may only be invoked in GL. +- b) G1, G2, G3 sets – No restrictions are placed on the character sets that may be designated for these sets; these graphic character sets may only be invoked in GR. +- c) The locking and single shift functions allowed are as follows: + - LS0 to invoke the G0 set into GL; + - LS1R to invoke the G1 set into GR; + - LS2R to invoke the G2 set into GR; + - LS3R to invoke the G3 set into GR; + - SS2 to invoke one character from the G2 set into GL; + - SS3 to invoke one character from the G3 set into GL. + +(Here GL and GR refer to the left and right hand parts respectively of the 8-bit code table.) +- d) When specifying the presentation attribute “graphic character sets”, it is necessary to invoke character sets for both GL and GR. Thus, an allowed character set shall be designated into G0 [see item a) above] and invoked into GL. It is also necessary to invoke a character set into GR which has been designated into G1, G2 or G3 set. +- e) The empty set shall be designated into G1 and invoked into GR if no other specific character set is invoked in GR. + +The code extension techniques allowed are illustrated in Figures 4 and 5. + +The announcement and encoding of these functions are to be as specified in ISO 2022. + +The code extension techniques that are used or may be used in a basic component shall be specified by the presentation attribute “code extension announcers”. The default code extension announcers used throughout a document may be specified in the document profile using the presentation attribute “code extension announcers”. + +NOTE – In accordance with CCITT Rec. T.416 | ISO 8613-6, there is no restriction concerning the number of graphic character sets which may be designated and/or invoked in the presentation attribute “graphic character sets” providing the restrictions defined in this subclause are applied. Hence designation to a particular G set overrides the previous designation to that set, and invocation to GL or GR overrides the previous invocation to GL or GR respectively. Thus, the sequential order of designation and/or invocation sequences in the attribute “graphic character sets” is significant. + +### 6.5.5 Line spacing + +Line spacing values of 100, 150, 200, 300 and 400 BMUs may be specified. The values of 200, 300 and 400 BMUs are basic; the use of any other value in a document is non-basic and shall be indicated in the document profile. + +The line spacing may be specified at the beginning of the content associated with a basic component using the presentation attribute “line spacing”. The value may be changed anywhere within the content portion using the control function SVS. + +### 6.5.6 Character spacing + +Character spacing values of 80, 100, 120, 160 and 200 BMUs may be specified. The value of 120 BMUs is basic; the use of any other value in a document is non-basic and shall be indicated in the document profile. + +![Diagram illustrating Code extension features (basic case). It shows an 8-bit code table divided into GL and GR sections. Arrows indicate mappings from G0, G1, G2, and G3 to the code table. G0 maps to LS0, G1 to LS1R, G2 to LS1R, and G3 to LS1R. The diagram also shows the IRV of ISO/646 (ISO-IR6) and an empty set.](7133ccf78043568ca62ecbcd43628a4a_img.jpg) + +[8-bit code table] + +GL GR + +LS0 LS1R [Invocation] + +G0 G1 G2 G3 + +The IRV of ISO/646 (ISO-IR6) Empty set [Designation] + +T0810570-92/d04 + +Diagram illustrating Code extension features (basic case). It shows an 8-bit code table divided into GL and GR sections. Arrows indicate mappings from G0, G1, G2, and G3 to the code table. G0 maps to LS0, G1 to LS1R, G2 to LS1R, and G3 to LS1R. The diagram also shows the IRV of ISO/646 (ISO-IR6) and an empty set. + +FIGURE 4/T.502 +Code extension features (basic case) + +![Diagram illustrating Code extension features (all possible cases). It shows an 8-bit code table divided into GL and GR sections. Arrows indicate mappings from G0, G1, G2, and G3 to the code table. G0 maps to LS0, G1 to LS1R, G2 to LS2R, and G3 to LS3R. The diagram also shows the IRV of ISO/IEC 646 (ISO-IR6) or the primary set of ISO 6937-2 or a version of ISO/IEC 646, and any registered graphic character set.](552265bdbcf6d43d341fd018a9076269_img.jpg) + +[8-bit code table] + +GL GR + +SS2 SS3 + +LS0 LS1R LS2R LS3R [Invocation] + +G0 G1 G2 G3 + +The IRV of ISO/IEC 646 (ISO-IR6) or the primary set of ISO 6937-2 or a version of ISO/IEC 646 Any registered graphic character set [Designation] + +T0810580-92/d05 + +Diagram illustrating Code extension features (all possible cases). It shows an 8-bit code table divided into GL and GR sections. Arrows indicate mappings from G0, G1, G2, and G3 to the code table. G0 maps to LS0, G1 to LS1R, G2 to LS2R, and G3 to LS3R. The diagram also shows the IRV of ISO/IEC 646 (ISO-IR6) or the primary set of ISO 6937-2 or a version of ISO/IEC 646, and any registered graphic character set. + +FIGURE 5/T.502 +Code extension features (all possible cases) + +The character spacing may be specified at the beginning of the content associated with a basic component using the presentation attribute “character spacing”. The value may be changed anywhere within the content portion using the control functions SHS and SCS. + +#### NOTES + +- 1 A character spacing value of 160 BMUs is provided for use with Korean Hangul characters. +- 2 SHS parameters 0, 1, 2 and 3 are provided. The use of parameters 5 and 6 may be provided in a future edition of this Profile for use with Chinese characters. + +### 6.5.7 Character path and line progression + +Both from left to right and from right to left horizontal writing directions may be specified within a document. The line progression is then from top to bottom only on the page. + +Character path values of 0 degrees and 180 degrees may be specified. The value of 0 degrees is basic. The value of 180 degrees is non-basic and must be indicated in the document profile. + +The values of character path may be specified at the beginning of the content associated with a basic component using the presentation attribute “character path”. The value shall not be changed within a content portion. + +The line progression supported by this Profile is 90 degrees and 270 degrees. The value of 270 degrees is basic. The value of 90 degrees is non-basic and must be indicated in the document profile. The line progression value of 270 degrees may be specified in case of the character path 0 degrees, and the line progression value of 90 degrees may be specified in case of the character path value of 180 degrees. + +### 6.5.8 Character orientation + +The character orientation supported by this Profile is 0 degrees only which is the standard default value specified in CCITT Rec. T.416 | ISO 8613-6. Thus, the character orientation shall not be specified. + +### 6.5.9 Emphasis + +The following modes of emphasising graphic characters may be specified as basic: + +- default rendition; +- normal intensity; +- increase intensity (bold); +- italicized; +- not italicized; +- underlined; +- not underlined. + +The following modes of emphasising graphic characters may be specified as non-basic: + +- crossed-out; +- not crossed-out. + +The above mentioned non-basic modes shall be indicated in the document profile. If no default mode is explicitly specified in the document profile, then the default mode is default rendition. + +The mode of emphasis may be specified at the beginning of the content associated with a basic component using the presentation attribute “graphic rendition”. The mode may be changed anywhere within the content using the control function SGR. + +The mode of emphasis remains in effect within the content associated with a basic component until changed into a mutually exclusive mode or by the specification of 'default rendition'. Mutually exclusive modes are normal/increased intensity, italicized/not italicized, underlined/not underlined and crossed-out/not crossed-out. One mode from each mutually exclusive set may be in operation at any point in the document content. + +Default rendition cancels the effect of all modes of emphasis that are currently in operation and specifies that the text shall be displayed in accordance with the default rendition parameters set for the presentation device. Thus, for example, if it is required to ensure that the content is not underlined, then it is necessary to explicitly specify that underlined is not to be used. + +### 6.5.10 Tabulation + +Tabulation stop positions may be specified at any character position along the character path. Each stop is specified by means of the following: + +- a) The tabulation position, relative to the margin position is in the direction opposite to the character path. +- b) An optional alignment qualifier that specifies the type of alignment to be used at the designated tabulation position. The type may be specified as one of the following: + - start aligned; + - end aligned; + - centred; + - aligned around. + +These alignment qualifiers are defined in CCITT Rec. T.416 | ISO 8613-6. If the alignment qualifier is not explicitly specified, then it is assumed that start aligned is to be used. + +Only one set of tabulation stops can be specified to be applicable to the content associated with a basic component. No limit is placed on the number of tabulation stops that may be specified within a given set. + +The set of tabulation stop positions associated with the content of a basic component are specified using the presentation attribute “line layout table”. Tabulation stop positions are invoked within the content using the control function STAB. + +The tabulation reference numbers used in the control function STAB and associated presentation attribute “line layout table” shall be chosen so that, in any given line layout table the reference numbers are unique, sequential in the direction of the character path and do not include leading zeroes. + +### 6.5.11 Indentation + +Indentation is the distance between the first character on a line of content and the position of the margin that is in the direction opposite to the character path. Thus, the value of indentation specified determines the line home position (as defined in CCITT Rec. T.416 | ISO 8613-6). + +Indentation acts as temporary alternation in the position of the offset in the direction opposite to the direction of the character path. When text is formatted, it is intended to be laid out between the indentation position and the margin position in the direction of the character path. + +Any value of indentation may be specified for basic logical components using the presentation attribute “indentation”. The indentation value shall not be changed within a content portion. + +### 6.5.12 Alignment + +This feature is concerned with how the first and last characters on each line of character content are to be laid out during the formatting process. + +The following values of alignment may be specified as basic: + +- start aligned; +- end aligned; +- centred; +- justified. + +The semantics of these values are as defined in CCITT Rec. T.416 | ISO 8613-6. + +The presentation attribute “alignment” is used to specify the alignment that is applicable to the content associated with a basic component. The alignment value cannot be changed within a content portion. + +### 6.5.13 First line format + +This feature specifies how the first line of the content associated with a basic component is to be laid out and provides for the itemization of paragraphs. + +It allows the first character in the content to be positioned at some point along the character path relative to the indentation position (as defined in 6.5.11). This point may be in the direction of the character path or in the direction opposite to the direction of the character path relative to the indentation position. + +In addition, this feature provides for the specification of an item identifier on the first line. The item identifier is a string of characters that precedes and is separated from the remaining characters that form the first line. The control function CR (Carriage Return) is used as the separator. + +The features provided correspond to examples 10.1 to 10.5 shown in Figure 10 of CCITT Rec. T.416 | ISO 8613-6. + +First line format is specified by the presentation attributes “first line offset” and “itemization”, and “indentation”. Only those values of the attributes which combine to form the examples shown in Figure 10 of CCITT Rec. T.416 | ISO 8613-6 may be used. + +### **6.5.14 Widow and orphan sizes** + +The widow size specifies the minimum number of lines of content that shall be allocated to a following frame or page when the content associated with a basic logical component is laid out such that it flows over two frames or pages. To accommodate this, it may be necessary to move a number of lines of content from one frame or page to the next frame or page. + +The orphan size specifies the minimum number of lines of content that shall be placed in the current frame or page when the content associated with a basic logical component is split over two frames or pages. If this minimum cannot be accommodated, then the whole content shall be placed in the next frame or page. + +Any value of widow or orphan size may be specified using the presentation attributes “widow size” and “orphan size” respectively. + +Widow and orphan size may only be specified for character content placed in the body area of pages. + +### **6.5.15 Reverse character string** + +Bi-directional writing is supported by this Profile (see 6.5.7). Hence, a string of characters in a content portion associated with a basic component may be specified to be imaged in the reverse direction of the immediately preceding character string. Such strings may be specified by the control function SRS as defined in CCITT Rec. T.416 | ISO 8613-6. + +This control function is provided for cases in which the text belongs to different languages and the character content is written, for example, from left to right or from right to left within the same line of characters, dependent upon the language and/or character set being used. + +NOTE – The use of this control function cannot be indicated in the document profile. Thus, it is intended that implementations should ignore this control function when reverse character string layout and presentation is not supported. + +### **6.5.16 Superscripts and subscripts** + +Superscripts and subscripts may be specified anywhere within the content associated with a basic component by using the control functions PLU and PLD. The use of these control functions shall be in accordance with CCITT Rec. T.416 | ISO 8613-6. + +### **6.5.17 Line breaks** + +The control functions BPH and NBH may be inserted in processable and formatted processable form character content to indicate where line breaks may occur or may not occur respectively, when the content is laid out. + +### **6.5.18 Substitution of characters** + +The control function SUB is provided to represent characters produced by a local system that cannot be represented by a character within a character set supported by this Profile. + +### 6.5.19 Initial point + +The initial point which is applicable to basic layout components may be specified by the attribute “initial offset”. Any value may be specified. + +### 6.5.20 Use of control functions + +The following is a list of all the control functions and parameter values (where applicable) that may be specified in character content: + +| | | +|------|-------------------------------------------------------------------------------| +| SHS | Select character spacing (allowed parameter values: 0, 1, 2, 3) | +| SCS | Set character spacing (allowed parameter values: 80, 100, 120, 160, 200 BMUs) | +| SVS | Select line spacing (allowed parameter values: 0, 1, 2, 3, 4) | +| SGR | Select graphic rendition (allowed parameter values: 0, 1, 3, 4, 9, 22-24, 29) | +| STAB | Selective tabulation (allowed parameter values: any) | +| SRS | Start reverse string (allowed parameter values: any) | +| PLD | Partial line down | +| PLU | Partial line up | +| BPH | Break permitted here | +| NBH | No break here | +| JFY | No justify | +| SUB | Substitute | +| SP | Space | +| CR | Carriage return | +| LF | Line feed | +| SOS | Start of string | +| ST | String terminator | + +Code extension control functions (see 6.5.4) + +The use of all these control functions, with exception of SP, CR, LF, SOS and ST, are described in 6.5.3 through 6.5.19. + +### 6.5.21 Formatting the content + +The attribute “formatting indicator” shall not be specified within documents that are conformant with this Profile. + +## 6.6 Miscellaneous features + +### 6.6.1 Application comments + +Specification of the attribute “application comments” is mandatory for all object classes contained in a document that conforms to this Profile. Specification of this attribute is mandatory for all objects that do not refer to an object class. Specification of this attribute is optional for all objects that refer to object classes. + +This attribute is structured so that it contains two fields. The first field is mandatory when the attribute is specified and contains a numeric string which uniquely identifies the constituent constraint applicable to the constituent for which the attribute is specified. This facilitates the processing of documents. A list of these identifiers is given in Table 2. + +#### NOTES + +1 The values of the constituent constraint numeric identifiers are not unique between the logical and layout structures, and therefore in order to identify the constituent constraint applicable to a constituent, it is necessary to know the structure of which the constituent is a part. + +2 For constituent constraints that correspond to each other between the hierarchically related profiles to which this Profile belongs, the same constituent constraint numeric identifier is specified. + +TABLE 2/T.502 + +#### **List of constituent constraint numeric identifier** + +| Logical constituent constraints | Constituent constraint numeric identifier | +|---------------------------------|-------------------------------------------| +| DocumentLogicalRoot | 0 | +| Passage | 1 | +| BodyText | 14 | +| CommonContent | 19 | +| CommonText | 20 | +| PageNumber | 40 | +| Layout constituent constraints | Constituent constraint numeric identifier | +| DocumentLayoutRoot | 0 | +| PageSet | 1 | +| Page | 2 | +| RectoPage | 3 | +| VersoPage | 4 | +| BasicHeader | 27 | +| BasicBody | 28 | +| SpecificBlock | 30 | +| BasicFooter | 33 | + +The second field is optional and may contain any information that is relevant to the application or user. The format of the second field is not defined in this Profile and the interpretation of this field depends upon a private agreement between the originator and recipient of the document. + +The encoding of the attribute “application comments” is defined in 8.1.3 and 8.2.3. + +### 6.6.2 Alternative representation + +The content information in a content portion may be replaced by a string of characters specified in the attribute “alternative representation”. This attribute may be specified in content portions. + +The specification and use of this attribute is optional. The string of characters specified must belong to the character repertoires indicated in the document profile attribute “alternative representation character sets” (see 6.7.4.3). If the latter attribute is not explicitly specified in the document profile, then the default defined in CCITT Rec. T.410-Series | ISO 8613 is assumed. The control functions SP, CR and LF may also be used within the character string but no other control function is allowed; hence graphic character set cannot be changed within the alternative representation. + +### 6.6.3 Page numbering + +As described in 6.2.4.3, the constituent constraint PageNumber contains a content generator which may refer to a page number. This content generator is evaluated when the document is laid out and this mechanism provides a means of reproducing the appropriate number of each page of a document. + +The content generator has the following format: + +<string-literal><num-expr><string-literal> + +The format of this content generator is defined in the macro PGNUMBER (see 7.3.1). + +The <string-literal> fields are optional and are pre-defined character strings. The basic character repertoire used to specify these strings is ISO-IR 6 (the IRV of ISO/IEC 646). Any other character repertoire, and subrepertoire if appropriate, may be used provided that it is designated and invoked by the appropriate code designation and invocation sequences and indicated in the document profile as a non-basic value. SP and no other control functions may be used in these strings. + +The field <num-expr> is a reference to a binding 'PGnum' which specifies the number of the page concerned. This binding is initialized at the document layout root or page set level (see the macro INITIALISEPGNUM in 7.4.1) and automatically incremented on each successive page (see the macro PAGENUMBER in 7.4.1). By placing initialization on the layout root, rather than on the pageset class(es), the pagenumbers may be defined to be continued from one pageset to the next. + +The content associated with logical object classes of the type PageNumber is laid out in a frame of one of the following types: BasicHeader or BasicFooter (see 6.3.6) using the logical source mechanism. Thus, when the appropriate frame is being laid out, the field <num-expr> in the content generator contained in a logical object class of the type PageNumber is evaluated and this determines the value of the binding 'PGnum' that is associated with the current page being laid out. + +The number associated with the binding 'PGnum' is applied to a string function during its evaluation in order to convert the number into a character string. This enables the number to be represented in the form of an Arabic numeric string, an upper or lower case Roman numeric string or an upper or lower case alphabetic string. + +Each page class may refer to a different instance of logical object classes of the type PageNumber and this allows different page numbering formats to be used for different parts of the document. + +An example of page numbering is "Page X" which consists of two concatenated character strings. The first is the literal character string 'Page' and this is concatenated to a string function denoted by 'X'. When 'X' is evaluated in a particular instance it may, for example, return the character string 'iv', the Roman numerical (lower case) for the number '4'. + +### **6.6.4 User readable comments** + +Information which is to be interpreted as comments relevant to constituents and associated content portions may be specified using the attribute "user readable comments". This information is intended for presentation to humans. + +The information consists of a string of characters which shall belong to one of the character repertoires indicated in the document profile attribute "comments character sets" (see 6.7.4.2). If the latter attribute is not explicitly specified, then the default defined in CCITT Rec. T.410-Series | ISO 8613 is assumed. The control functions CR, LF, SP and code extension control functions may also be used within the character string but no other control functions are allowed. + +### **6.6.5 User visible name** + +Information which may be used to identify constituents within a document may be specified using the attribute "user visible name". This information is intended for presentation to humans, for example, to assist in the editing of documents. + +The information consists of a string of characters which shall belong to one of the character repertoires indicated in the document profile attribute "comments character sets" (see 6.7.4.2). If the latter attribute is not explicitly specified, then the default defined in CCITT Rec. T.410-Series | ISO 8613 is assumed. The control functions CR, LF, SP and code extension control functions may also be used within the character string but no other control functions are allowed. + +## **6.7 Document management features** + +Information relating to the document as a whole is specified in the document profile which is represented by the constituent *DocumentProfile*. This constituent must be specified in every document. + +The information in the document profile is classified into the following categories: + +- document constituent information; +- document identification information; +- document default information; +- non-basic characteristics information; +- document management information. + +The information in the document profile may be of interest to the user or may be used for machine processing of the document. + +### **6.7.1 Document constituent information** + +This information specifies which constituents are used to represent the document. + +#### **6.7.1.1 Presence of document constituents** + +This information indicates which constituents are included in the document. That is, this information indicates whether or not the document contains a generic logical structure, a specific logical structure, a generic layout structure, a specific layout structure, layout styles and presentation styles. It is mandatory to specify this information in the document profile. + +### **6.7.2 Document identification information** + +This information relates to the identification of the document. This information is divided into six categories. + +#### **6.7.2.1 Document application profile information** + +This information indicates the document application profile to which the document belongs. It is mandatory to specify this information using the attribute “document application profile”. + +#### **6.7.2.2 Document architecture class information** + +This information indicates the document architecture class to which the document belongs (see 6.1). It is mandatory to specify this information using the attribute “document architecture class”. + +#### **6.7.2.3 Content architecture classes information** + +This information indicates the content architecture classes used in the document (see 6.5.2). It is mandatory to specify this information using the attribute “content architecture classes”. + +#### **6.7.2.4 Interchange format class information** + +This information indicates the interchange format class used to represent the document (see clause 8). It is mandatory to specify this information using the attribute “interchange format class”. + +#### **6.7.2.5 ODA version information** + +This information indicates the International Standard or CCITT Recommendation to which the document conforms. It also specifies a calendar date, which indicates that the document conforms to the version of the International Standard or CCITT Recommendation and any addenda that are current on that date. It is mandatory to specify this information using the attribute “ODA version”. + +#### **6.7.2.6 Document reference** + +This information serves to identify the document. Typically this information is allocated to the document by the creator of the document. The identifier may consist of an ASN.1 object identifier or string of characters. It is mandatory to specify this information using the attribute “document reference”. + +### **6.7.3 Document default information** + +This information specifies various default values for attributes used in the document. The default values that are allowed are specified in the various subclauses of clause 6. The specification of this information is only required when it is required to specify a default value which is other than the standard default value specified in CCITT Rec. T.410-Series | ISO 8613. + +Default values for the following groups of attributes may be specified: + +- document architecture attributes; +- character content attributes. + +### **6.7.4 Non-basic characteristics information** + +This information specifies the non-basic attribute values specified in the document. It is mandatory to specify a non-basic attribute value in the document profile when such a value is used in the document. + +The following types of non-basic attribute values may be specified: + +- profile character sets; +- comments character sets; +- alternative representation character sets; +- page dimensions; +- medium-types; +- character presentation features. + +Further information concerning document profile, comments and alternative representation character sets is given below. + +#### **6.7.4.1 Profile character sets** + +Some document profile attributes have values consisting of character strings, for example, the document management attributes. The character sets used in these character strings are specified by the document profile attribute “profile character sets”. + +This attribute “profile character sets” specifies a code extension announcer and designations of character sets, which are subject to the following restrictions: + +- The code extension announcer shall be 04/03 when specified. This code extension announcer specifies the use of G0 and G1 sets in an 8-bit environment and also the invocation of G0 and G1 sets into GL and GR respectively. Thus, in each attribute to which this attribute applies, invocation shift functions are not necessary, because G0 and G1 sets are implicitly invoked by this code extension announcer. +- G0 set – Only ISO-IR 6 (the IRV of ISO/IEC 646), ISO-IR 2 (the primary set of ISO 6937), or any other version of ISO 646 may be designated for this set; these graphic character sets are implicitly invoked in GL. +- G1 set – No restrictions are placed on the graphic character sets that may be designated for this set; these graphic character sets are implicitly invoked in GR. +- The empty set shall be designated into G1 and invoked into GR if no other specific character set is invoked in GR. + +If the attribute “profile character sets” is not specified, then the default defined in CCITT Rec. T.410-Series | ISO 8613 is assumed. + +#### **6.7.4.2 Comments character sets** + +The character sets assumed to have been designated and optionally invoked at the beginning of the character strings specified by the attributes “user readable comments” (see 6.6.4) and “user visible name” (see 6.6.5) are specified using the document profile attribute “comments character sets”. + +It also specifies code extension techniques and the graphic character sets which may be used in the attributes “user readable comments” and “user visible name”. + +If this attribute is specified, the code extension techniques which may be used in the “user readable comments” and “user visible name” shall be announced by appropriate code extension announcers. The use of G0 set and GL shall always be announced. Other code extension announcers are to be specified according to the requirements of a particular document. + +Two kinds of code extension techniques are permitted for this attribute. One is to use GL and GR without shift functions, and the other is to use various character sets by shift functions. The former is rather restricted but no shift functions are necessary in the “user readable comments” and “user visible name”. The same restriction as in 6.7.4.1 is applied in this case. The latter permits various usages of character sets but invocations shall be specified by shift functions in the “user readable comments” and “user visible name”. The same restriction as in 6.5.4 is applied in this case. + +All the graphic character sets which may be used in the attributes “user readable comments” and “user visible name” shall be designated in the “comments character sets”. + +There are no restrictions concerning the number of graphic character sets which are designated and/or invoked in the “comments character sets”; hence designation to the same G set overrides the previous G set. + +If the attribute “comments character sets” is not specified, then the default defined in CCITT Rec. T.410-Series | ISO 8613 is assumed. + +#### **6.7.4.3 Alternative representation character sets** + +This attribute specifies the graphic character sets designated and invoked at the beginning of the attribute “alternative representation” other than the standard default graphic character sets. + +The restriction on profile character sets described in 6.7.4.1 is also applied. If this attribute is not explicitly specified in the document profile, the default defined in CCITT Rec. T.410-Series | ISO 8613 is assumed. + +### **6.7.5 Document management attributes** + +Document management attributes contain information about the content of the document and its purpose. Information relating to the following may be specified: + +- document description (see the Note below); +- dates and times; +- originators; +- other user information; +- external references; +- local file references; +- content attributes; +- security information. + +The attributes that may be used to specify this information are defined in CCITT Rec. T.414 | ISO 8613-4. + +The string of characters used in the document management attributes shall belong to the character sets indicated in the document profile attribute “profile character sets” (see 6.7.4.1). If the latter attribute is not explicitly specified in the document profile, then the default defined in CCITT Rec. T.410-Series | ISO 8613 is assumed. + +The control functions SP, CR and LF may also be used within the character strings but no other control functions are allowed. Hence the graphic character set cannot be changed in the document management attributes. + +NOTE – The document description includes the specification of the document reference (see 6.7.2.6). + +# 7 Specification of constituent constraints + +This clause specifies the definitions of the constituent constraints which may be represented by data streams conforming to this Profile. + +## 7.1 Introduction + +The structure diagrams illustrating the relationships between the constituents in the logical structures are shown in 7.1.1. The macros indicated on these diagrams are defined in 7.3.1. These macros define the permissible values for the attribute “generator for subordinates” that are applicable to the constituents, and define the allowed structures that are supported by this Profile. + +The structure diagrams illustrating the layout structures are shown in 7.1.2. The macros indicated on these diagrams are defined in 7.4.1. + +### 7.1.1 Diagrams of relationships of logical constituents + +See Figures 6 and 7. + +![A hierarchical diagram showing the relationships between logical constituents. At the top is a box labeled 'Document LogicalRoot'. A vertical line connects it to a box labeled 'Passage', with the label 'DocLogRootGFS' to the right of the line. Another vertical line connects 'Passage' to a box labeled 'BodyText', with the label 'PassageGFS' to the right of the line. Below the 'BodyText' box is the identifier 'T0804910-90/d06'.](875c6f4f441fdd3ca7e1908fd1582983_img.jpg) + +``` +graph TD; A[Document LogicalRoot] ---|DocLogRootGFS| B[Passage]; B ---|PassageGFS| C[BodyText]; +``` + +T0804910-90/d06 + +A hierarchical diagram showing the relationships between logical constituents. At the top is a box labeled 'Document LogicalRoot'. A vertical line connects it to a box labeled 'Passage', with the label 'DocLogRootGFS' to the right of the line. Another vertical line connects 'Passage' to a box labeled 'BodyText', with the label 'PassageGFS' to the right of the line. Below the 'BodyText' box is the identifier 'T0804910-90/d06'. + +FIGURE 6/T.502 +The body part of the generic logical structure + +![](e451401f8fa77b466f401d5fce15b26c_img.jpg) + +``` + +graph TD + CommonContent[CommonContent] --- CommonContentGFS + CommonContentGFS --- CommonText[CommonText] + CommonContentGFS --- PageNumber[PageNumber] + +``` + +T0804920-90/d07 + +FIGURE 7/T.502 +**The common part of the generic logical structure** + +### 7.1.2 Diagrams of relationships of layout constituents + +See Figures 8 and 9. + +![](1cac1845cf99a3f64ae00cd2bb4f9ed7_img.jpg) + +``` + +graph TD + DocumentLayoutRoot[Document +LayoutRoot] --- DocLayRootGFS + DocLayRootGFS --- PageSet[PageSet] + PageSet --- PageSetGFS + PageSetGFS --- Page[Page] + PageSetGFS --- RectoPage[RectoPage] + PageSetGFS --- VersoPage[VersoPage] + Page -.- P1[P] + RectoPage -.- P2[P] + VersoPage -.- P3[P] + +``` + +T0810590-92/d08 + +FIGURE 8/T.502 +**The layout structure – Document root and page sets** + +![Diagram showing the layout structure of a page. A dashed box labeled 'P' is connected to a horizontal line. Below this line are three boxes: 'BasicHeader', 'BasicBody', and 'BasicFooter'. The connection to 'BasicBody' is labeled 'PageGFS'. The identifier 'T0810600-92/d09' is at the bottom right.](f57c7b37d7a05a99618104f390089f03_img.jpg) + +``` + +graph TD + P[P] --- Line[ ] + Line --- BasicHeader[BasicHeader] + Line --- BasicBody[BasicBody] + Line --- BasicFooter[BasicFooter] + BasicBody --- PageGFS[PageGFS] + +``` + +T0810600-92/d09 + +Diagram showing the layout structure of a page. A dashed box labeled 'P' is connected to a horizontal line. Below this line are three boxes: 'BasicHeader', 'BasicBody', and 'BasicFooter'. The connection to 'BasicBody' is labeled 'PageGFS'. The identifier 'T0810600-92/d09' is at the bottom right. + +FIGURE 9/T.502 +The layout structure – Page structure + +### 7.1.3 Notation + +This clause is written in accordance with the Document Application Profile Proforma and Notation (DAPPN) of CCITT Rec. T.411 | ISO 8613-1, Annex F. The following clarifications and minor extensions apply : + +#### a) [Clarification] + +The value range definition for the attributes “subordinates” and “imaging order” specify the set of object instances that may occur. The ordering and number (which may be zero) of object instances for the attribute “subordinates” must be in accordance with the value of the attribute “generator for subordinates” in the respective object class. + +#### b) [Clarification] + +The value “ANY\_STRING” may include code extension control functions as well as graphic characters. + +#### c) [Extension] + +In order to write the specification of the usage of character sets and code extension control functions precisely, the following extensions are applied: + +1) Table 3 defines the symbols that are introduced to denote shift functions. + +2) <escape-sequence> is extended to include shift functions: + +<escape-sequence> ::= 'ESC' <octet>... [<invocation-control-function>] ; + +<invocation-control-function> ::= 'LS0'|'LS1R'|'LS2R'|'LS3R'|'SS2'|'SS3' ; + +3) Data type specification for #ESC in content information is extended as: + +<escape-sequence>... + +TABLE 3/T.502 +Symbols to denote shift functions + +| Symbol | Shift function | Coded representation | +|--------|---------------------------|----------------------| +| LS0 | Locking shift zero | 00/15 | +| LS1R | Locking shift one right | ESC 07/14 | +| LS2R | Locking shift two right | ESC 07/13 | +| LS3R | Locking shift three right | ESC 07/12 | +| SS2 | Single shift two | 08/14 | +| SS3 | Single shift three | 08/15 | + +## 7.2 Document profile constituent constraints + +### 7.2.1 Macro definitions + +``` +DEFINE(FC, "ASN.1{ 2 8 2 6 0 }" -- formatted character content --) +DEFINE(PC, "ASN.1{ 2 8 2 6 1 }" -- processable character content --) +DEFINE(FPC, "ASN.1{ 2 8 2 6 2 }" -- formatted processable character content --) +``` + +``` +DEFINE(FDA, "'formatted'") +DEFINE(PDA, "'processable'") +DEFINE(FPDA, "'formatted-processable'") +DEFINE(PDA-FPDA, "'processable' | 'formatted-processable'") + +DEFINE(DAC, "DocumentProfile (Document-architecture-class)") +DEFINE(GLAS, "DocumentProfile (Generic-layout-structure)") +DEFINE(COMPLETE, "'complete-generator-set'") +``` + +``` +DEFINE(BasicPageDimensions, " + REQ #horizontal-dimension + {REQ #fixed-dimension {<=9240}}, + REQ #vertical-dimension + {REQ #fixed-dimension {<=12400}} +| REQ #horizontal-dimension + {REQ #fixed-dimension {<=12400}}, + REQ #vertical-dimension + {REQ #fixed-dimension {<=9240}} ") +``` + +-- Any size equal to or smaller than CARA (Common Assured Reproduction Area) of ISO A4 and ANSI-A. Both +-- Landscape and Portrait may be specified. +-- Note that the above macro is defined for clarification of the specification and is not used in any other part of this DAP +-- specification. + +``` +DEFINE(NonBasicPageDimensions, " + REQ #horizontal-dimension + {REQ #fixed-dimension {<=14030}}, + REQ #vertical-dimension + {REQ #fixed-dimension {12401..19840}} +| REQ #horizontal-dimension + {REQ #fixed-dimension {9241..14030}}, + REQ #vertical-dimension + {REQ #fixed-dimension {<=19840}} + -- up to ISO A3 portrait -- + +| REQ #horizontal-dimension + {REQ #fixed-dimension {12401..19840}}, + REQ #vertical-dimension + {REQ #fixed-dimension {<=14030}} +| REQ #horizontal-dimension + {REQ #fixed-dimension {<=19840}}, + REQ #vertical-dimension + {REQ #fixed-dimension {9241..14030}} + -- up to ISO A3 landscape -- + +| REQ #horizontal-dimension + {REQ #fixed-dimension {<=13200}}, + REQ #vertical-dimension + {REQ #fixed-dimension {12401..20400}} +| REQ #horizontal-dimension + {REQ #fixed-dimension {9241..13200}}, + REQ #vertical-dimension + {REQ #fixed-dimension {<=20400}} + -- up to ANSI-B portrait -- +``` + +``` + +| REQ #horizontal-dimension + {REQ #fixed-dimension {12401..20400}}, +REQ #vertical-dimension + {REQ #fixed-dimension {<=13200}} +| REQ #horizontal-dimension + {REQ #fixed-dimension {<=20400}}, +REQ #vertical-dimension + {REQ #fixed-dimension {9241..13200}} ") + -- up to ANSI-B landscape -- + +DEFINE(PermissiblePageDimensions, " + REQ #horizontal-dimension + {REQ #fixed-dimension {<=14030}}, + REQ #vertical-dimension + {REQ #fixed-dimension {<=19840}} -- up to ISO A3 portrait -- +| REQ #horizontal-dimension + {REQ #fixed-dimension {<=19840}}, + REQ #vertical-dimension + {REQ #fixed-dimension {<=14030}} -- up to ISO A3 landscape -- +| REQ #horizontal-dimension + {REQ #fixed-dimension {<=13200}}, + REQ #vertical-dimension + {REQ #fixed-dimension {<=20400}} -- up to ANSI-B portrait -- +| REQ #horizontal-dimension + {REQ #fixed-dimension {<=20400}}, + REQ #vertical-dimension + {REQ #fixed-dimension {<=13200}} -- up to ANSI-B landscape -- ") + +DEFINE(NominalPageSizes, + "REQ #horizontal-dimension {14030}, + REQ #vertical-dimension {19840} -- ISO A3 portrait -- +| REQ #horizontal-dimension {19840}, + REQ #vertical-dimension {14030} -- ISO A3 landscape -- +| REQ #horizontal-dimension {9920}, + REQ #vertical-dimension {14030} -- ISO A4 portrait -- +| REQ #horizontal-dimension {14030}, + REQ #vertical-dimension {9920} -- ISO A4 landscape -- +| REQ #horizontal-dimension {7015}, + REQ #vertical-dimension {9920} -- ISO A5 portrait -- +| REQ #horizontal-dimension {9920}, + REQ #vertical-dimension {7015} -- ISO A5 landscape -- +| REQ #horizontal-dimension {12141}, + REQ #vertical-dimension {17196} -- JIS B4 (Japanese legal) portrait -- +| REQ #horizontal-dimension {17196}, + REQ #vertical-dimension {12141} -- JIS B4 (Japanese legal) landscape -- +| REQ #horizontal-dimension {8598}, + REQ #vertical-dimension {12141} -- JIS B5 (Japanese letter) portrait -- +| REQ #horizontal-dimension {12141}, + REQ #vertical-dimension {8598} -- JIS B5 (Japanese letter) landscape -- +| REQ #horizontal-dimension {10200}, + REQ #vertical-dimension {16800} -- ANSI legal portrait -- +| REQ #horizontal-dimension {16800}, + REQ #vertical-dimension {10200} -- ANSI legal landscape -- +| REQ #horizontal-dimension {10200}, + REQ #vertical-dimension {13200} -- ANSI-A portrait -- +| REQ #horizontal-dimension {13200}, + REQ #vertical-dimension {10200} -- ANSI-A landscape -- +| REQ #horizontal-dimension {13200}, + REQ #vertical-dimension {20400} -- ANSI-B portrait -- +| REQ #horizontal-dimension {20400}, + REQ #vertical-dimension {13200} -- ANSI-B landscape -- ") + +``` + +``` + +DEFINE(GRAPHICRENDITIONS, " + {'cancel' | 'increased-intensity' | 'italicized' | 'underlined' | 'crossed-out' + | 'normal-intensity' | 'not-italicized' | 'not-underlined' | 'not-crossed-out'}... ") + +-- Macro defining permissible code extension announcer. Note that all the values are basic. -- + +DEFINE(CDEXTEN, " ESC 02/00 05/00, -- Use G0 & LS0 -- + [ ESC 02/00 05/03 ], -- Use G1 & LS1R -- + [ ESC 02/00 05/05 ], -- Use G2 & LS2R -- + [ ESC 02/00 05/07 ], -- Use G3 & LS3R -- + [ ESC 02/00 05/10 ], -- Use G2 & SS2 -- + [ ESC 02/00 05/11 ] -- Use G3 & SS3 -- ") + +-- Macro defining code extension announcer for DAP defaults -- + +DEFINE(DAP-DEFAULT-CDEXTEN, "$CDEXTEN") + +-- Macros defining final character for designation -- + +DEFINE(FCORE, "04/02" -- A final character designating ISO-IR 6 (the IRV of + -- ISO/IEC 646, i.e. ASCII) --) + +DEFINE(F646, "-- A final character designating any version of ISO/IEC 646, except ISO-IR 6 --") + +DEFINE(F94S, "-- A final character designating any registered 94 single byte graphic + -- character set, optionally preceded by one or more intermediate + -- characters as defined in Annex C of ISO 2022 --") + +DEFINE(F94M, "-- A final character designating any registered 94 multi byte graphic + -- character set, optionally preceded by one or more intermediate + -- characters as defined in Annex C of ISO 2022 --") + +DEFINE(F96S, "-- A final character designating any registered 96 single byte graphic + -- character set, optionally preceded by one or more intermediate + -- characters as defined in Annex C of ISO 2022 --") + +DEFINE(F96M, "-- A final character designating any registered 96 multi byte graphic + -- character set, optionally preceded by one or more intermediate + -- characters as defined in Annex C of ISO 2022 --") + +DEFINE(FEMPTY, "07/14" -- The empty set --) + +-- Macro defining a revision number of a character set -- + +DEFINE(REV, "-- An octet between 04/00 and 07/14, which represents a revision number as + -- defined in ISO 2022. --") + +-- Macros defining designation sequences -- + +DEFINE(DEG-CORE-G0, "ESC 02/08 $FCORE") + + -- Designate 94 characters of ISO-IR 6 (the IRV of ISO/IEC 646 ) to G0 -- + +DEFINE(DEG-646-G0, "ESC 02/08 $F646") + + -- Designate any version of ISO/IEC 646, except ISO-IR 6, to G0 -- + +DEFINE(DEG-ANY-G1, "{[ESC 02/06 $REV] + {ESC 02/09 $F94S + | ESC 02/04 02/09 $F94M + | ESC 02/13 $F96S + | ESC 02/04 02/13 $F96M}"}) + + -- Designate any character set to G1 -- + +``` + +``` + +DEFINE(DEG-ANY-G2, "{[ESC 02/06 $REV] + {ESC 02/10 $F94S + | ESC 02/04 02/10 $F94M + | ESC 02/14 $F96S + | ESC 02/04 02/14 $F96M}}") +-- Designate any character set to G2 -- + +DEFINE(DEG-ANY-G3, "{[ESC 02/06 $REV] + {ESC 02/11 $F94S + | ESC 02/04 02/11 $F94M + | ESC 02/15 $F96S + | ESC 02/04 02/15 $F96M}}") +-- Designate any character set to G3 -- + +DEFINE(DEG-EMPTY-G1, "ESC 02/09 $FEMPTY") +-- Designate the empty set to G1 -- + +-- Macro defining permissible graphic character sets -- + +DEFINE(PERMIT-GRCHAR, "{$DEG-CORE-G0 LS0 | $DEG-646-G0 LS0}, + {{$DEG-ANY-G1 LS1R + | $DEG-ANY-G2 LS2R + | $DEG-ANY-G3 LS3R}... + | $DEG-EMPTY-G1 LS1R}") + +-- Macro defining graphic character sets for DAP defaults -- + +DEFINE(DAP-DEFAULT-GRCHAR, "$PERMIT-GRCHAR") + +-- Macro defining basic graphic character sets. Note that this macro is defined for clarification of the specification and +-- is not used in any other part of this DAP specification. -- + +DEFINE(BASIC-GRCHAR, "$DEG-CORE-G0 LS0, + $DEG-EMPTY-G1 LS1R") + +-- Macro defining non-basic graphic character sets -- + +DEFINE(NON-BASIC-GRCHAR, "{$DEG-646-G0 + | $DEG-ANY-G1 + | $DEG-ANY-G2 + | $DEG-ANY-G3}... ") + +-- Macro defining character sets used in document profile attributes -- + +DEFINE(PROFCHAR, " + ESC 02/00 04/03 -- announcement of use of G0 and G1, and + -- invocation into GL and GR respectively (no shift + -- functions are necessary) -- + + { $DEG-CORE-G0 | $DEG-646-G0 } -- designate G0 -- + { $DEG-ANY-G1 | $DEG-EMPTY-G1 } -- designate G1 -- +") + +-- Macro defining comments character sets -- + +DEFINE(COMCHAR, " + -- in the case to use both GL and GR without shift functions -- + ESC 02/00 04/03 -- announcement of use of G0 and G1, and + -- invocation into GL and GR respectively (no shift + -- functions are necessary) -- + { $DEG-CORE-G0 | $DEG-646-G0 } -- designate G0 -- + { $DEG-ANY-G1 | $DEG-EMPTY-G1 } -- designate G1 -- + + | -- in the case of use of various character sets (shift functions are necessary) -- + {ESC 02/00 05/00, -- announcement to use G0 and LS0 -- + [ESC 02/00 05/03], -- announcement to use G1 and LS1R -- + [ESC 02/00 05/05], -- announcement to use G2 and LS2R -- + [ESC 02/00 05/07], -- announcement to use G3 and LS3R -- + [ESC 02/00 05/10], -- announcement to use G2 and SS2 -- + [ESC 02/00 05/11]} -- announcement to use G3 and SS3 -- +") + +``` + +``` + + { $DEG-CORE-G0 | $DEG-646-G0 } designate G0 + + {{ $DEG-ANY-G1 designate G1 + | $DEG-ANY-G2 designate G2 + | $DEG-ANY-G3 } ... designate G3 + | $DEG-EMPTY-G1 } + + ") + + Macro defining character sets used for alternative representation +DEFINE(ALTCHAR, "$PROFCHAR") + +7.2.2 Constituent constraints + +7.2.2.1 DocumentProfile + +{ +CASE $DAC OF { + + $FDA: PERM Generic-layout-structure {'factor-set'}, + REQ Specific-layout-structure {'present'}, + PERM Presentation-styles {'present'} + + $PDA: PERM Generic-layout-structure {'complete-generator-set'}, + REQ Generic-logical-structure {'complete-generator-set' + | 'partial-generator-set'}, + + REQ Specific-logical-structure {'present'}, + PERM Presentation-styles {'present'}, + PERM Layout-styles {'present'} + + $FPDA: REQ Generic-layout-structure {'complete-generator-set'}, + REQ Specific-layout-structure {'present'}, + REQ Generic-logical-structure {'complete-generator-set' + | 'partial-generator-set'}, + + REQ Specific-logical-structure {'present'}, + PERM Presentation-styles {'present'}, + REQ Layout-styles {'present'} + +}, + + Document characteristics + +REQ Document-application-profile { See clause 8 for a definition of the + permitted values for this attribute }, + +PERM Document-application-profile-defaults { +CASE $DAC OF { + $FDA: {PERM #content-architecture-class { $FC | $FPC }} + $PDA: {PERM #content-architecture-class { $FC | $PC | $FPC }} + $FPDA: {PERM #content-architecture-class { $FC | $FPC }} +}, + +PERM #dimensions { $PermissiblePageDimensions }, + +PERM #medium-type { PERM #nominal-page-size { $NominalPageSizes }, + PERM #side-of-sheet { ANY_VALUE } }, + +PERM #page-position { ANY_VALUE }, + +PERM #character-content-defaults { + PERM #alignment { ANY_VALUE }, + PERM #character-path { '0-degrees' | '180-degrees' }, + PERM #character-spacing { 80 | 100 | 120 | 160 | 200 }, + PERM #code-extension-announcers { $DAP-DEFAULT-CDEXTEN }, + PERM #first-line-offset { ANY_VALUE }, + PERM #graphic-character-sets { $DAP-DEFAULT-GRCHAR }, + +``` + +``` + + PERM #graphic-character-subrepertoire {ANY_VALUE}, + PERM #graphic-rendition {$GRAPHICRENDITIONS}, + PERM #itemization {ANY_VALUE}, + PERM #line-layout-table {ANY_VALUE}, + PERM #line-progression {'90-degrees' | '270-degrees'}, + PERM #line-spacing {100 | 150 | 200 | 300 | 400}, + PERM #initial-offset {ANY_VALUE}, + PERM #indentation {ANY_VALUE}, + PERM #orphan-size {ANY_VALUE}, + PERM #widow-size {ANY_VALUE} + } + +}, + +REQ Document-architecture-class {$FDA | $PDA | $FPDA}, +REQ Content-architecture-classes {[$FC], [$PC], [$FPC]}, +REQ Interchange-format-class {-- See clause 8 for a definition of the + -- permitted values for this attribute --}, + +REQ Oda-version {REQ #standard-or-recommendation + {"CCITT Rec. T.410-Series(1988)|ISO 8613(1989); version 1.1"}, + REQ #publication-date {"1992-01-01"}}, + +-- Non-basic document characteristics -- + +PERM Profile-character-sets {$PROFCHAR}, +PERM Comments-character-sets {$COMCHAR}, +PERM Alternative-representation-character-sets {$ALTCHAR}, +PERM Page-dimensions {PMUL {$NonBasicPageDimensions}}, +PERM Medium-types {PMUL + {PERM #nominal-page-size + {$NominalPageSizes}, + -- All permissible page sizes are non-basic. -- + PERM #side-of-sheet {'recto'|'verso'}}} + +}, + +PERM Presentation-features { + PERM #character-presentation-features { + PERM #character-path {'180-degrees'}, + PERM #line-progression {'90-degrees'}, + PMUL {PERM #graphic-character-sets {$NON-BASIC-GRCHAR}}, + PMUL {PERM #graphic-character-subrepertoire {ANY_VALUE}}, + PMUL {PERM #character-spacing {80 | 100 | 160 | 200}}, + PMUL {PERM #line-spacing {100 | 150}}, + PMUL {PERM #graphic-rendition {'crossed-out' | 'not-crossed-out'}} + } +} + +}, + +-- Document management attributes -- + +-- Document description -- + +PERM Title {ANY_STRING}, +PERM Subject {ANY_STRING}, +PERM Document-type {ANY_STRING}, +PERM Abstract {ANY_STRING}, +PERM Keywords {ANY_STRING...}, +REQ Document-reference {ANY_VALUE}, + +-- Dates and times -- + +``` + +| | | | +|------|----------------------------|---------------| +| PERM | Document-date-and-time | {ANY_STRING}, | +| PERM | Creation-date-and-time | {ANY_STRING}, | +| PERM | Local-filing-date-and-time | {ANY_VALUE}, | +| PERM | Expiry-date-and-time | {ANY_STRING}, | +| PERM | Start-date-and-time | {ANY_STRING}, | +| PERM | Purge-date-and-time | {ANY_STRING}, | +| PERM | Release-date-and-time | {ANY_STRING}, | +| PERM | Revision-history | {ANY_VALUE}, | + +-- Originators -- + +| | | | +|------|---------------|------------------| +| PERM | Organizations | {ANY_STRING...}, | +| PERM | Preparers | {ANY_VALUE}, | +| PERM | Owners | {ANY_VALUE}, | +| PERM | Authors | {ANY_VALUE}, | + +-- Other user information -- + +| | | | +|------|------------------------|------------------| +| PERM | Copyright | {ANY_VALUE}, | +| PERM | Status | {ANY_STRING}, | +| PERM | User-specific-codes | {ANY_STRING...}, | +| PERM | Distribution-list | {ANY_VALUE}, | +| PERM | Additional-information | {ANY_VALUE}, | + +-- External references -- + +| | | | +|------|-------------------------------|--------------| +| PERM | References-to-other-documents | {ANY_VALUE}, | +| PERM | Superseded-documents | {ANY_VALUE}, | + +-- Local file references -- + +| | | | +|------|-----------------------|--------------| +| PERM | Local-file-references | {ANY_VALUE}, | +|------|-----------------------|--------------| + +-- Content attributes -- + +| | | | +|------|-----------------|------------------| +| PERM | Document-size | {ANY_INTEGER}, | +| PERM | Number-of-pages | {ANY_INTEGER}, | +| PERM | Languages | {ANY_STRING...}, | + +-- Security information -- + +| | | | +|------|-------------------------|-----------------| +| PERM | Authorization | {ANY_VALUE}, | +| PERM | Security-classification | {ANY_STRING}, | +| PERM | Access-rights | {ANY_STRING...} | + +} + +## 7.3 Logical constituent constraints + +### 7.3.1 Macro definitions + +``` + +DEFINE(DocLogRootGFS, " + <construction-expr> ::= REP OBJECT_CLASS_ID_OF(Passage);") + +DEFINE(PassageGFS, " + <construction-expr> ::= REP OBJECT_CLASS_ID_OF(BodyText);") + +DEFINE(CommonContentGFS, " + <construction-expr> ::= <construction-factor> | SEQ(<construction-factor>...); + + <construction-factor> ::= OBJECT_CLASS_ID_OF(PageNumber) + | OBJECT_CLASS_ID_OF(CommonText);") + +``` + +``` + +DEFINE(PGNUMBER, " + <string-expr> ::= [ANY_STRING] <str-exp> [ANY_STRING]; + + <str-exp> ::= MAKE-STRING(<num-exp>) + | UPPER-ALPHA(<num-exp>) + | LOWER-ALPHA(<num-exp>) + | UPPER-ROMAN(<num-exp>) + | LOWER-ROMAN(<num-exp>); + + <num-exp> ::= B_REF(SUP(CURR-INST('frame', (CURR-OBJ))))("PGnum");") + +DEFINE(DocumentLogicalRoot, "REQ #constraint-name {"0"}, + PERM #external-data {ANY_VALUE}") + +DEFINE(Passage, "REQ #constraint-name {"1"}, + PERM #external-data {ANY_VALUE}") + +DEFINE(BodyText, "REQ #constraint-name {"14"}, + PERM #external-data {ANY_VALUE}") + +DEFINE(CommonContent, "REQ #constraint-name {"19"}, + PERM #external-data {ANY_VALUE}") + +DEFINE(CommonText, "REQ #constraint-name {"20"}, + PERM #external-data {ANY_VALUE}") + +DEFINE(PageNumber, "REQ #constraint-name {"40"}, + PERM #external-data {ANY_VALUE}") + +``` + +### 7.3.2 Factor constraints + +#### 7.3.2.1 FACTOR ANY-LOGICAL + +``` + +{ +GENERIC: + REQ Object-type {VIRTUAL}, + REQ Object-class-identifier {ANY_VALUE} + +SPECIFIC: + PERM Object-type {VIRTUAL}, + REQ Object-identifier {ANY_VALUE}, + REQ Object-class {VIRTUAL} + +SPECIFIC_AND_GENERIC: + PERM User-readable-comments {ANY_STRING}, + PERM User-visible-name {ANY_STRING} +} + +``` + +### 7.3.3 Constituent constraints + +#### 7.3.3.1 DocumentLogicalRoot + +``` + +: ANY-LOGICAL { +GENERIC: + REQ Object-type {'document-logical-root'}, + REQ Generator-for-subordinates {$DocLogRootGFS}, + REQ Application-comments {$DocumentLogicalRoot} + +SPECIFIC: + PERM Object-type {'document-logical-root'}, + REQ Object-class {OBJECT_CLASS_ID_OF + (DocumentLogicalRoot)}, + REQ Subordinates {SUB_ID_OF(Passage)+}, + PERM Application-comments {$DocumentLogicalRoot} +} + +``` + +#### 7.3.3.2 Passage + +: ANY-LOGICAL { + +GENERIC: + +| | | | +|-----|----------------------------|-------------------------------| +| REQ | Object-type | {'composite-logical-object'}, | +| REQ | Generator-for-subordinates | {\$PassageGFS}, | +| REQ | Application-comments | {\$Passage} | + +SPECIFIC: + +| | | | +|------|--------------|--------------------------------| +| PERM | Object-type | {'composite-logical-object'}, | +| REQ | Object-class | {OBJECT_CLASS_ID_OF(Passage)}, | +| REQ | Subordinates | {SUB_ID_OF(BodyText)+}, | + +CASE \$GLAS OF { + +    \$COMPLETE: + +| | | | +|-----|--------------|-------------------------| +| REQ | Layout-style | {STYLE_ID_OF(L-Style1)} | +|-----|--------------|-------------------------| + +    VOID: + +| | | | +|------|--------------|-------------------------| +| PERM | Layout-style | {STYLE_ID_OF(L-Style1)} | +|------|--------------|-------------------------| + +}, + +| | | | +|------|----------------------|-------------| +| PERM | Application-comments | {\$Passage} | +|------|----------------------|-------------| + +} + +#### 7.3.3.3 BodyText + +: ANY-LOGICAL { + +GENERIC: + +| | | | +|-----|----------------------|---------------------------| +| REQ | Object-type | {'basic-logical-object'}, | +| REQ | Application-comments | {\$BodyText} | + +SPECIFIC: + +| | | | +|------|------------------|---------------------------------| +| PERM | Object-type | {'basic-logical-object'}, | +| REQ | Object-class | {OBJECT_CLASS_ID_OF(BodyText)}, | +| REQ | Content-portions | {CONTENT_ID_OF | + +    (Character-content-portion)+}, + +| | | | +|------|--------------------|--------------------------| +| PERM | Presentation-style | {STYLE_ID_OF(P-Style1)}, | +|------|--------------------|--------------------------| + +| | | | +|------|----------------------------|---------------------| +| PERM | Content-architecture-class | {SFC SPC SFPC}, | +|------|----------------------------|---------------------| + +| | | | +|------|--------------|--------------------------| +| PERM | Layout-style | {STYLE_ID_OF(L-Style2)}, | +|------|--------------|--------------------------| + +| | | | +|------|----------------------|--------------| +| PERM | Application-comments | {\$BodyText} | +|------|----------------------|--------------| + +} + +#### 7.3.3.4 CommonContent + +{ + +GENERIC: + +| | | | +|------|----------------------------|-------------------------------| +| REQ | Object-type | {'composite-logical-object'}, | +| REQ | Object-class-identifier | {ANY_VALUE}, | +| REQ | Generator-for-subordinates | {\$CommonContentGFS}, | +| REQ | Application-comments | {\$CommonContent}, | +| PERM | User-readable-comments | {ANY_STRING}, | +| PERM | User-visible-name | {ANY_STRING} | + +} + +#### 7.3.3.5 CommonText + +{ + +GENERIC: + +| | | | +|-----|-------------------------|---------------------------| +| REQ | Object-type | {'basic-logical-object'}, | +| REQ | Object-class-identifier | {ANY_VALUE}, | +| REQ | Content-portions | {CONTENT_ID_OF | + +    (Character-content-portion)}, + +| | | | +|------|--------------------|--------------------------| +| PERM | Presentation-style | {STYLE_ID_OF(P-Style4)}, | +|------|--------------------|--------------------------| + +| | | | +|------|----------------------------|---------------------| +| PERM | Content-architecture-class | {SFC SPC SFPC}, | +|------|----------------------------|---------------------| + +| | | | +|------|--------------|--------------------------| +| PERM | Layout-style | {STYLE_ID_OF(L-Style3)}, | +|------|--------------|--------------------------| + +| | | | +|-----|----------------------|-----------------| +| REQ | Application-comments | {\$CommonText}, | +|-----|----------------------|-----------------| + +| | | | +|------|------------------------|---------------| +| PERM | User-readable-comments | {ANY_STRING}, | +|------|------------------------|---------------| + +| | | | +|------|-------------------|--------------| +| PERM | User-visible-name | {ANY_STRING} | +|------|-------------------|--------------| + +} + +#### 7.3.3.6 PageNumber + +``` +{ +GENERIC: + REQ Object-type {'basic-logical-object'}, + REQ Object-class-identifier {ANY_VALUE}, + REQ Content-generator {SPGNUMBER}, + PERM Presentation-style {STYLE_ID_OF(P-Style4)}, + PERM Content-architecture-class {SFC | SPC | SFPC}, + PERM Layout-style {STYLE_ID_OF(L-Style3)}, + REQ Application-comments {$PageNumber}, + PERM User-readable-comments {ANY_STRING}, + PERM User-visible-name {ANY_STRING} +} +``` + +## 7.4 Layout constituent constraints + +### 7.4.1 Macro definitions + +``` +DEFINE(DocLayRootGFS, " + <construction-expr> ::= REP CHO({OBJECT_CLASS_ID_OF(PageSet)}...); +") + +DEFINE(PageSetGFS, "<construction-expr> ::= <constraint-1> + | <constraint-2> + | <constraint-3> + | <constraint-4> + | <constraint-5>; + +<constraint-1> ::= OBJECT_CLASS_ID_OF(Page); + +<constraint-2> ::= REP OBJECT_CLASS_ID_OF(Page); + +<constraint-3> ::= REP SEQ(OBJECT_CLASS_ID_OF(RectoPage) + OPT OBJECT_CLASS_ID_OF(VersoPage)) + | REP SEQ(OBJECT_CLASS_ID_OF(VersoPage) + OPT OBJECT_CLASS_ID_OF(RectoPage)); + +<constraint-4> ::= SEQ(OBJECT_CLASS_ID_OF(Page) + OPT REP OBJECT_CLASS_ID_OF(Page)); + +<constraint-5> ::= SEQ(OBJECT_CLASS_ID_OF(Page) + OPT REP SEQ(OBJECT_CLASS_ID_OF(RectoPage) + OPT OBJECT_CLASS_ID_OF(VersoPage))) + | SEQ(OBJECT_CLASS_ID_OF(Page) + OPT REP SEQ(OBJECT_CLASS_ID_OF(VersoPage) + OPT OBJECT_CLASS_ID_OF(RectoPage))); +") + +DEFINE(PageGFS, " + <construction-expr> ::= SEQ([OBJECT_CLASS_ID_OF (BasicHeader)] + OBJECT_CLASS_ID_OF (BasicBody) + [OBJECT_CLASS_ID_OF (BasicFooter)]); +") + +DEFINE(INITIALISEPGNUM, " + REQ #binding-name {""PGnum""}, + REQ #binding-value {>=1} +") + +DEFINE(PAGENUMBER, " + REQ #binding-name {""PGnum""}, + REQ #binding-value {<string-expr> ::= + INC(B_REF(PREC(CURR-OBJ)) (""PGnum""));} +") +``` + +| | | | +|----------------------------|-----------------------|---------------| +| DEFINE(DocumentLayoutRoot, | "REQ #constraint-name | {"'0""}, | +| | PERM #external-data | {ANY_VALUE}") | +| DEFINE(PageSet, | "REQ #constraint-name | {"'1""}, | +| | PERM #external-data | {ANY_VALUE}") | +| DEFINE(Page, | "REQ #constraint-name | {"'2""}, | +| | PERM #external-data | {ANY_VALUE}") | +| DEFINE(RectoPage, | "REQ #constraint-name | {"'3""}, | +| | PERM #external-data | {ANY_VALUE}") | +| DEFINE(VersoPage, | "REQ #constraint-name | {"'4""}, | +| | PERM #external-data | {ANY_VALUE}") | +| DEFINE(BasicHeader, | "REQ #constraint-name | {"'27""}, | +| | PERM #external-data | {ANY_VALUE}") | +| DEFINE(BasicBody, | "REQ #constraint-name | {"'28""}, | +| | PERM #external-data | {ANY_VALUE}") | +| DEFINE(SpecificBlock, | "REQ #constraint-name | {"'30""}, | +| | PERM #external-data | {ANY_VALUE}") | +| DEFINE(BasicFooter, | "REQ #constraint-name | {"'33""}, | +| | PERM #external-data | {ANY_VALUE}") | + +### 7.4.2 Factor constraints + +#### 7.4.2.1 FACTOR ANY-COMPOSITE-LAYOUT + +``` + +{ +GENERIC: + REQ Object-type {VIRTUAL}, + REQ Object-class-identifier {ANY_VALUE} + +SPECIFIC: + PERM Object-type {VIRTUAL}, + REQ Object-identifier {ANY_VALUE} + +SPECIFIC_AND_GENERIC: + PERM User-readable-comments {ANY_STRING}, + PERM User-visible-name {ANY_STRING} +} + +``` + +#### 7.4.2.2 FACTOR ANY-PAGE + +``` + +: ANY-COMPOSITE-LAYOUT { +GENERIC: + REQ Object-type {'page'}, + CASE $DAC OF { + $PDA-FPDA: + PERM Bindings {$PAGENUMBER}, + REQ Generator-for-subordinates {$PageGFS} + } + +SPECIFIC: + PERM Object-type {'page'}, + REQ Subordinates {SUB_ID_OF(BasicHeader), + SUB_ID_OF(BasicBody), + SUB_ID_OF(BasicFooter)} + +SPECIFIC_AND_GENERIC: + PERM Dimensions {$PermissiblePageDimensions}, + PERM Page-position {ANY_VALUE} +} + +``` + +#### 7.4.2.3 FACTOR ANY-FRAME + +``` +: ANY-COMPOSITE-LAYOUT { +GENERIC: + REQ Object-type {'frame'} + +SPECIFIC: + PERM Object-type {'frame'}, + REQ Subordinates {SUB_ID_OF(SpecificBlock)+} + +SPECIFIC_AND_GENERIC: + PERM Position {REQ #fixed-position + {REQ #horizontal-position {ANY_VALUE}, + REQ #vertical-position {ANY_VALUE}}}, + + PERM Dimensions {REQ #horizontal-dimension + {REQ #fixed-dimension {ANY_VALUE}}, + REQ #vertical-dimension + {REQ #fixed-dimension {ANY_VALUE}}} + +} +``` + +### 7.4.3 Constituent constraints + +#### 7.4.3.1 DocumentLayoutRoot + +``` +: ANY-COMPOSITE-LAYOUT { +GENERIC: + REQ Object-type {'document-layout-root'}, + CASE $DAC OF { + SPDA-FPDA: + PERM Bindings {$INITIALISEPGNUM}, + REQ Generator-for-subordinates {$DocLayRootGFS} + }, + REQ Application-comments {$DocumentLayoutRoot} + +SPECIFIC: + PERM Object-type {'document-layout-root'}, + CASE $DAC OF { + SFDA: PERM Object-class {OBJECT_CLASS_ID_OF(DocumentLayoutRoot)} + SFPDA: REQ Object-class {OBJECT_CLASS_ID_OF(DocumentLayoutRoot)} + }, + REQ Subordinates {SUB_ID_OF (PageSet)+}, + PERM Application-comments {$DocumentLayoutRoot} + +} +``` + +#### 7.4.3.2 PageSet + +``` +: ANY-COMPOSITE-LAYOUT { +GENERIC: + REQ Object-type {'page-set'}, + CASE $DAC OF { + SPDA-FPDA: + PERM Bindings {$INITIALISEPGNUM}, + REQ Generator-for-subordinates {$PageSetGFS} + }, + REQ Application-comments {$PageSet} + +SPECIFIC: + PERM Object-type {'page-set'}, + CASE $DAC OF { + SFDA: PERM Object-class {OBJECT_CLASS_ID_OF (PageSet)} + SFPDA: REQ Object-class {OBJECT_CLASS_ID_OF (PageSet)} + }, + REQ Subordinates {SUB_ID_OF (Page)+, + SUB_ID_OF (RectoPage)+, + SUB_ID_OF (VersoPage)+ }, + PERM Application-comments {$PageSet} + +} +``` + +#### 7.4.3.3 Page + +: ANY-PAGE { + +GENERIC: + +REQ Application-comments {\$Page} + +SPECIFIC: + +CASE \$DAC OF { + +\$FDA: PERM Object-class {OBJECT\_CLASS\_ID\_OF(Page)} + +\$FPDA: REQ Object-class {OBJECT\_CLASS\_ID\_OF(Page)} + +}, + +PERM Application-comments {\$Page} + +SPECIFIC\_AND\_GENERIC: + +PERM Medium-type {PERM #nominal-page-size + {\$NominalPageSizes}, + PERM #side-of-sheet {ANY\_VALUE}} + +} + +#### 7.4.3.4 RectoPage + +: ANY-PAGE { + +GENERIC: + +REQ Application-comments {\$RectoPage}, + +REQ Medium-type {PERM #nominal-page-size + +{\$NominalPageSizes}, + +REQ #side-of-sheet {'recto' | 'unspecified'}} + +SPECIFIC: + +CASE \$DAC OF { + +\$FDA: PERM Object-class {OBJECT\_CLASS\_ID\_OF (RectoPage)} + +\$FPDA: REQ Object-class {OBJECT\_CLASS\_ID\_OF (RectoPage)} + +}, + +PERM Application-comments {\$RectoPage}, + +PERM Medium-type {PERM #nominal-page-size + +{\$NominalPageSizes}, + +PERM #side-of-sheet {'recto' | 'unspecified'}} + +} + +#### 7.4.3.5 VersoPage + +: ANY-PAGE { + +GENERIC: + +REQ Application-comments {\$VersoPage}, + +REQ Medium-type {PERM #nominal-page-size + +{\$NominalPageSizes}, + +REQ #side-of-sheet {'verso' | 'unspecified'}} + +SPECIFIC: + +CASE \$DAC OF { + +\$FDA: PERM Object-class {OBJECT\_CLASS\_ID\_OF (VersoPage)} + +\$FPDA: REQ Object-class {OBJECT\_CLASS\_ID\_OF (VersoPage)} + +}, + +PERM Application-comments {\$VersoPage}, + +PERM Medium-type {PERM #nominal-page-size + +{\$NominalPageSizes}, + +PERM #side-of-sheet {'verso' | 'unspecified'}} + +} + +#### 7.4.3.6 BasicHeader + +: ANY-FRAME { + +GENERIC: + +CASE \$DAC OF { + +\$PDA-\$FPDA: + +REQ Logical-source {OBJECT\_CLASS\_ID\_OF (CommonContent)} + +}, + +REQ Application-comments {\$BasicHeader} + +##### **SPECIFIC:** + +``` + CASE $DAC OF { + $FDA: PERM Object-class {OBJECT_CLASS_ID_OF (BasicHeader)} + $FPDA: REQ Object-class {OBJECT_CLASS_ID_OF (BasicHeader)} + }, + PERM Application-comments {$BasicHeader} +} +``` + +#### **7.4.3.7 BasicBody** + +: ANY-FRAME { + +##### **GENERIC:** + +``` + REQ Application-comments {$BasicBody} +``` + +##### **SPECIFIC:** + +``` + CASE $DAC OF { + $FDA: PERM Object-class {OBJECT_CLASS_ID_OF (BasicBody)} + $FPDA: REQ Object-class {OBJECT_CLASS_ID_OF (BasicBody)} + }, + PERM Application-comments {$BasicBody} +} +``` + +#### **7.4.3.8 BasicFooter** + +: ANY-FRAME { + +##### **GENERIC:** + +``` + CASE $DAC OF { + $PDA-FPDA: + REQ Logical-source {OBJECT_CLASS_ID_OF (CommonContent)} + }, + REQ Application-comments {$BasicFooter} +``` + +##### **SPECIFIC:** + +``` + CASE $DAC OF { + $FDA: PERM Object-class {OBJECT_CLASS_ID_OF (BasicFooter)} + $FPDA: REQ Object-class {OBJECT_CLASS_ID_OF (BasicFooter)} + }, + PERM Application-comments {$BasicFooter} +} +``` + +#### **7.4.3.9 SpecificBlock** + +{ + +##### **SPECIFIC:** + +``` + REQ Object-type {'block'}, + REQ Object-identifier {ANY_VALUE}, + REQ Content-portions {CONTENT_ID_OF(Character-content-portion)+}, + PERM Presentation-style {STYLE_ID_OF(P-Style1) + | STYLE_ID_OF(P-Style4)}, + PERM Content-architecture-class {$FC | $FPC}, + + PERM Presentation-attributes { + PERM #character-attributes { + PERM #alignment {ANY_VALUE}, + PERM #character-path {'0-degrees' | '180-degrees'}, + PERM #character-spacing {80 | 100 | 120 | 160 | 200}, + PERM #code-extension-announcers {$CDEXTEN}, + PERM #first-line-offset {ANY_VALUE}, + PERM #graphic-character-sets {$PERMIT-GRCHAR}, + PERM #graphic-character-subrepertoire {ANY_VALUE}, + PERM #graphic-rendition {$GRAPHICRENDITIONS}, + PERM #itemization {ANY_VALUE}, + PERM #line-layout-table {ANY_VALUE}, + PERM #line-progression {'90-degrees' | '270-degrees'}, + PERM #line-spacing {100 | 150 | 200 | 300 | 400}, + PERM #initial-offset {ANY_VALUE} + } + } +}, +``` + +| | | | +|------|------------------------|------------------------------------------------------------------------------------------------------------------------------------| +| PERM | User-readable-comments | {ANY_STRING}, | +| PERM | User-visible-name | {ANY_STRING}, | +| PERM | Position | {REQ #fixed-position<br>REQ #horizontal-position {ANY_VALUE},<br>REQ #vertical-position {ANY_VALUE}}}, | +| PERM | Dimensions | {REQ #horizontal-dimension<br>REQ #fixed-dimension {ANY_VALUE}},<br>REQ #vertical-dimension<br>REQ #fixed-dimension {ANY_VALUE}}}, | +| PERM | Application-comments | {{SpecificBlock} } | + +-- Each block in a BasicBody shall reference only one content portion. -- + +-- A block in a BasicHeader or BasicFooter may reference any number of content portions. -- + +## 7.5 Layout style constituent constraints + +### 7.5.1 Macro definitions + +-- No macro definitions are applicable in this clause. -- + +### 7.5.2 Factor constraints + +#### 7.5.2.1 FACTOR ANY-LAYOUT-STYLE + +``` +{ +REQ Layout-style-identifier {ANY_VALUE}, +PERM User-readable-comments {ANY_STRING}, +PERM User-visible-name {ANY_STRING} +} +``` + +### 7.5.3 Constituent constraints + +#### 7.5.3.1 L-Style1 + +: ANY-LAYOUT-STYLE { + +-- This style is used for the constituent constraints Passage only. -- + +``` +CASE $GLAS OF { + $COMPLETE: + PERM Indivisibility {'page' -- to layout object type -- + | 'null'}, + REQ Layout-object-class {OBJECT_CLASS_ID_OF (PageSet)} + VOID: + PERM Indivisibility {'page' -- to layout object type -- + | 'null'} +}} +``` + +#### 7.5.3.2 L-Style2 + +: ANY-LAYOUT-STYLE { + +-- This style is used for the constituent constraints BodyText only. -- + +``` +CASE $GLAS OF { + $COMPLETE: + PERM Indivisibility {'page' -- to layout object type -- + | 'null'}, + PERM New-layout-object {{OBJECT_CLASS_ID_OF (Page) + | OBJECT_CLASS_ID_OF (RectoPage) + | OBJECT_CLASS_ID_OF (VersoPage) + | OBJECT_CLASS_ID_OF (BasicBody) + -- to layout object class -- } + | 'page' -- to layout object type -- + | 'null'}, +}} +``` + +| | | | +|------|--------------------|--------------------------------------------------------------------------------------------------------------| +| PERM | Offset | {ANY_VALUE}, | +| PERM | Same-layout-object | {REQ {REQ #logical-object<br>{<object-id-expr> ::= PREC-OBJ(CURR-OBJ);}<br> REQ #logical-object {'null'}}}, | +| PERM | Separation | PERM #layout-object {'page'},<br>{PERM #leading-edge {ANY_INTEGER},<br>PERM #trailing-edge {ANY_INTEGER}} | + +VOID: + +| | | | +|------|--------------------|--------------------------------------------------------------------------------------------------------------| +| PERM | Indivisibility | {'page' -- to layout object type --<br> 'null'}, | +| PERM | New-layout-object | {'page' -- to layout object type--<br> 'null'}, | +| PERM | Offset | {ANY_VALUE}, | +| PERM | Same-layout-object | {REQ {REQ #logical-object<br>{<object-id-expr> ::= PREC-OBJ(CURR-OBJ);}<br> REQ #logical-object {'null'}}}, | +| PERM | Separation | PERM #layout-object {'page'},<br>{PERM #leading-edge {ANY_INTEGER},<br>PERM #trailing-edge {ANY_INTEGER}} | + +}} + +#### 7.5.3.3 L-Style3 + +: ANY-LAYOUT-STYLE { + +-- This style is used for the constituent constraints *CommonText* and *PageNumber*. -- + +| | | | +|------|---------------|--------------------------------------------------------------------------| +| PERM | Concatenation | {ANY_VALUE}, | +| PERM | Offset | {ANY_VALUE}, | +| PERM | Separation | {PERM #leading-edge {ANY_INTEGER},<br>PERM #trailing-edge {ANY_INTEGER}} | + +} + +## 7.6 Presentation style constituent constraints + +### 7.6.1 Macro definitions + +-- No macro definitions are applicable in this subclause. -- + +### 7.6.2 Factor constituent constraints + +#### 7.6.2.1 FACTOR ANY-PRESENTATION-STYLE + +| | | | +|------|-------------------------------|---------------| +| REQ | Presentation-style-identifier | {ANY_VALUE}, | +| PERM | User-readable-comments | {ANY_STRING}, | +| PERM | User-visible-name | {ANY_STRING} | + +} + +### 7.6.3 Constituent constraints + +#### 7.6.3.1 P-Style1 + +: ANY-PRESENTATION-STYLE { + +-- This style is used for the constituent constraints *BodyText* and *SpecificBlock*.-- + +| | | | +|------|----------------------------|--------------------------------| +| PERM | Presentation-attributes | { | +| PERM | #character-attributes | { | +| PERM | #alignment | {ANY_VALUE}, | +| PERM | #character-path | {'0-degrees' '180-degrees'}, | +| PERM | #character-spacing | {80 100 120 160 200}, | +| PERM | #code-extension-announcers | {\$CDEXTEN}, | +| PERM | #first-line-offset | {ANY_VALUE}, | + +``` + + PERM #graphic-character-sets {$PERMIT-GRCHAR}, + PERM #graphic-character-subrepertoire {ANY_VALUE}, + PERM #graphic-rendition {$GRAPHICRENDITIONS}, + PERM #itemization {ANY_VALUE}, + PERM #line-layout-table {ANY_VALUE}, + PERM #line-progression {'90-degrees' | '270-degrees'}, + PERM #line-spacing {100 | 150 | 200 | 300 | 400}, + PERM #indentation {ANY_VALUE}, + PERM #orphan-size {ANY_VALUE}, + PERM #widow-size {ANY_VALUE} + } +}} +``` + +#### 7.6.3.2 P-Style2 + +-- This presentation style is not used.-- + +#### 7.6.3.3 P-Style3 + +-- This presentation style is not used.-- + +#### 7.6.3.4 P-Style4 + +: ANY-PRESENTATION-STYLE { + +-- This style is used for the constituent constraints *CommonText*, *PageNumber* and *SpecificBlock*.-- + +``` + +PERM Presentation-attributes { + PERM #character-attributes { + PERM #alignment {ANY_VALUE}, + PERM #character-path {'0-degrees' | '180-degrees'}, + PERM #character-spacing {80 | 100 | 120 | 160 | 200}, + PERM #code-extension-announcers {$CDEXTEN}, + PERM #first-line-offset {ANY_VALUE}, + PERM #graphic-character-sets {$PERMIT-GRCHAR}, + PERM #graphic-character-subrepertoire {ANY_VALUE}, + PERM #graphic-rendition {$GRAPHICRENDITIONS}, + PERM #itemization {ANY_VALUE}, + PERM #line-layout-table {ANY_VALUE}, + PERM #line-progression {'90-degrees' | '270-degrees'}, + PERM #line-spacing {100 | 150 | 200 | 300 | 400}, + PERM #indentation {ANY_VALUE} + } +} +} +``` + +## 7.7 Content portion constituent constraints + +### 7.7.1 Macro definitions + +-- No macro definitions are applicable in this subclause.-- + +### 7.7.2 Factor constraints + +-- No factor constraints are applicable in this subclause.-- + +### 7.7.3 Constituent constraints + +#### 7.7.3.1 Character-content-portion + +``` + +{ +CASE $DAC OF { + $FDA : + REQ Content-identifier-layout {ANY_VALUE} +``` + +**SPDA:** +    **REQ**    **Content-identifier-logical**            **{ANY\_VALUE}** +                -- *This attribute is specified, if the content portion is associated with a basic* +                -- *logical object or a basic logical object class.* -- + +**SFPDA:** +    **REQ**    **Content-identifier-layout**            **{ANY\_VALUE},** +    **REQ**    **Content-identifier-logical**           **{ANY\_VALUE}** +                -- *Both attributes are specified, if the content portion is associated with a* +                -- *basic logical object and a basic layout object.* -- + +**| REQ**   **Content-identifier-logical**           **{ANY\_VALUE}** + +                -- *This attribute is specified, if the content portion is associated with a basic* +                -- *logical object class.*-- + +**},** + +**PERM    Alternative-representation           {ANY\_STRING},** +**PERM    Content-information                 {CHARACTER** +                                **{|#STAB                {ANY\_VALUE}** +                                **| #SHS                 {0 | 1 | 2 | 3 }**    -- *120, 100, 80 or 200 BMU* -- +                                **| #SCS                 {80 | 100 | 120 | 160 | 200}** +                                **| #SGR                 {\$GRAPHICRENDITIONS}** +                                **| #SVS                 { 0 | 1 | 2 | 3 | 4 }**   -- *200, 300, 400, 100 or 150 BMU* -- +                                **| #SRS                 {ANY\_VALUE}** +                                **| #JFY                 {0}** +                                **| #CR** +                                **| #LF** +                                **| #PLD** +                                **| #PLU** +                                **| #SP** +                                **| #SUB** +                                **| #BPH** +                                **| #NBH** +                                **| #SOS** +                                **| #ST** +                                **| #LS0** +                                **| #LS1R** +                                **| #LS2R** +                                **| #LS3R** +                                **| #SS2** +                                **| #SS3** +                                **| #ESC                 {\$DEG-CORE-G0}** +                                **| #ESC                 {\$DEG-646-G0}** +                                **| #ESC                 {\$DEG-ANY-G1}** +                                **| #ESC                 {\$DEG-ANY-G2}** +                                **| #ESC                 {\$DEG-ANY-G3}** +                                **| #ESC                 {\$DEG-EMPTY-G1}** +                                **} ...                  }** + +**}** + +### 8 Interchange format + +#### 8.1 Interchange format + +For conformance to this Profile, the ODIF interchange format class A shall be used. The value of the document profile attribute “interchange format” for this interchange format is 'if-a'. This form of ODIF is defined in CCITT Rec. T.415 | ISO 8613-5. + +Recommendation T.502 (11/94) 47 + +## 8.2 Document application profile object identifier + +The value for the document profile attribute “document application profile” for this interchange format is represented by the following object identifier: + +ASN.1 {2 8 4 0 11 0} + +## 8.3 Encoding of application comments + +The encoding of the attribute “application comments” is defined in this encoding as an octet string as specified in CCITT Rec. T.415 | ISO 8613-5. This document application profile requires that the encoding within that octet string be in accordance with the ASN.1 syntax specified in the following module definition: + +**FOD-DAPSpecification** + +**DEFINITIONS ::= BEGIN** + +**EXPORTS Appl-Comm-Encoding;** + +**Appl-Comm-Encoding ::= SEQUENCE {** +    **constraint-name [0] IMPLICIT PrintableString OPTIONAL,** +    **external-data [1] IMPLICIT OCTET STRING OPTIONAL }** + +**END** + +## 8.4 Data lengths + +The maximum length of data values of the type OCTET STRING, as defined in CCITT Rec. X.208 | ISO/IEC 8824, in data streams which may be encoded in accordance with this DAP is 32 767 octets. If it is required to encode an octet string of greater length than this, constructed type encoding shall be used. That is, data values greater than 32 767 in length shall be split into a sequence of strings shorter than 32 767, each of which is encoded using a primitive type. + +# Annex A + +## Amendments and technical corrigenda + +(This annex forms an integral part of this Recommendation) + +## A.1 Amendments + +### A.1.1 Amendments to the base standard + +The amendments applicable to this Profile includes text to be included in CCITT Rec. T.411 | ISO 8613-1 as the following annexes: + +- *Annex E* – Use of ISO/IEC 10021 (MOTIS) to interchange documents conforming to CCITT Rec. T.410-Series | ISO 8613 – Published as First extension to the CCITT Rec. T.410-Series (1988), Addendum II | ISO 8613-1 (1989): Amendment 1. +- *Annex F* – Document Application Profile proforma and notation – Published as CCITT Rec. T.411, Annex F (1991) | ISO 8613-1 (1989): Addendum 1. +- *Annex G* – Conformance testing methodology – Published as ISO 8613-1 (1989): Amendment 2. +- *Annex H* – Recording of documents conforming to CCITT Rec. T.410-Series | ISO 8613 on flexible disk cartridges conforming to ISO 9293 – Currently a Draft Amendment to ISO 8613-1 (1989), Annex H. + +This Profile does not include the following features of the amendment: + +- *Addendum on security* – Published as First extension to the CCITT Rec. T.410-Series (1988), Addendum V | ISO 8613 (1989): Addendum 4. +- *Addendum on styles* – Published as First extension to the CCITT Rec. T.410-Series (1988), Addendum IV | ISO 8613 (1989): Addendum 6. + +- *Addendum on alternative representation* – Published as First extension to the CCITT Rec. T.410-Series (1988), Addendum III | ISO 8613 (1989): Addendum 3. +- *Addendum on colour* – Published as Revision of the CCITT Rec. T.410-Series contained in COM VIII – R30-E Addendum 2 | ISO 8613 (1989): Amendment 2. +- *Addendum on tiled raster graphics* – Published as First extension to the CCITT Rec. T.410-Series (1988), Addendum I | ISO 8613 (1989): Addendum 1. + +### **A.1.2 Proposed changes to standards due to defects** + +This amendment addresses the inclusion of the CCITT Rec. T.410-Series (1988) | ISO 8613 (1989) Technical Corrigenda 1, 2 and 3. + +## **A.2 Technical corrigenda** + +### **A.2.1 Technical corrigenda to this Recommendation** + +There is no corrigenda specific to this Recommendation. + +## **A.3 Versions of the ODA International Standard** + +The version of the ODA International Standard defined in A.1 is known as version “1.1”. The associated date is 1992-01-01. The version of the ODA International Standard including all features of the amendments, addenda and technical corrigenda mentioned in A.1 is known as “version 1.2”. The associated date is 1992-07-01. + +The entries for ODA version for this DAP is: + +- Standard or Recommendation: “CCITT Rec. T.410-Series (1988) | ISO 8613 (1989); version 1.1”. +- Publication date: “1992-01-01”. + +# **Annex B** + +## **Recommended practices** + +(This annex does not form an integral part of this Recommendation) + +## **B.1 Transfer methods for ODA** + +### **B.1.1 Conveyance of ODA over CCITT X.400-1984** + +This describes how ODA body parts are to be encoded for transmission over a CCITT X.400-1984 service. + +An ODA body part is encoded as OdaBodyPart in the definition given below: + +``` + +OdaBodyPart ::= SEQUENCE { OdaBodyPartParameters, OdaData } +OdaBodyPartParameters ::= SET { + document-application-profile + [0] IMPLICIT OBJECT IDENTIFIER, + document-architecture-class + [1] IMPLICIT INTEGER { + formatted (0), + processable (1), + formatted-processable (2) } +OdaData ::= SEQUENCE OF Interchange-Data-Element + +``` + +NOTE – It is recommended to transfer an ODA document as a single body part with tag 12: + +``` +Oda [12] IMPLICIT OCTET STRING +``` + +The content of the octet string is encoded as OdaBodyPart, defined above. However, this is out of the scope of this Profile. + +### **B.1.2 Conveyance of ODA over FTAM** + +This describes the FTAM Document Type to be used for minimal storage and transfer capabilities of ODA data streams. It is recognized that enhanced capabilities may at some point be added. + +When using FTAM to transfer an ODA file, the FTAM-3, “ISO FTAM Unstructured Binary”, document type shall be specified. + +However, since files that do not contain ODA data streams can have the same document type, it is left up to the user of application programs that remotely access files using FTAM to know that a given file contains an ODA data stream. + +### **B.1.3 Conveyance of ODA over DTAM** + +This provides for information concerning the interchange of ODA based documents with DTAM protocols. + +DTAM (Document Transfer and Manipulation) is defined in the T.430-Series CCITT Recommendations and is, like ODA, an integral part of the T.400-Series CCITT Recommendations named *Open Document Architecture, Transfer and Manipulation*. + +The T.520-Series CCITT Recommendations contain *Communication Application Profiles (CAP)*. CCITT Recommendation T.522 describes the Communication Application Profile BT1 for document bulk transfer. CCITT Recommendation T.522 is applicable for the Open Document Format Profile (FOD) published in this Recommendation. + +NOTE – The use of BT1 within the end-to-end oriented Telematic Services Telefax 4 and Teletex is described in CCITT Recommendation T.561, 7.1, and CCITT Recommendation T.562, 7.1. + +### **B.1.4 Conveyance of ODA over flexible disks** + +The recommended method for interchanging ODA documents between systems by the exchange of magnetically recorded Flexible Disk Cartridges by the use of an annex to CCITT Rec. T.411 | ISO/IEC 8613-1 (to be published), *Recording of Documents Conforming to ISO 8613 on Flexible Disk Cartridges Conforming to ISO 9293*. This annex provides for recording each ODA document as a separate file as defined in ISO 9293. + +# **Annex C** + +## **Bibliography** + +(This annex does not form an integral part of this Recommendation) + +- CCITT Recommendation T.52 (1993), *Non-Latin coded character sets for telematic services*. +- CCITT Recommendation T.502 (1991), *Document Application Profile PM-11 for the Interchange of Character Content Documents in Processable and Formatted Forms*. +- CCITT Recommendation T.505 (1991), *Document Application Profile PM-26 for the Interchange of Mixed Content Documents in Processable and Formatted Forms*. +- ISO 8571:1988, *Information processing systems – Open Systems Interconnection – File Transfer, Access and Management*. +- ISO/IEC 9070:1991, *Information technology – SGML support facilities – Registration procedures for public text owner identifiers*. +- ISO/IEC TR 9573:1988, *Information processing – SGML support facilities – Techniques for using SGML*. +- ISO/IEC 10021:1990, *Information technology – Text Communication – Message-Oriented Text Interchange Systems (MOTIS)*. \ No newline at end of file diff --git a/marked/T/T-REC-T.505-199411-I_PDF-E/raw.md b/marked/T/T-REC-T.505-199411-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..497ff46953c2d8573d9edf60dd751ed583a06f14 --- /dev/null +++ b/marked/T/T-REC-T.505-199411-I_PDF-E/raw.md @@ -0,0 +1,5417 @@ + + +![ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol below it.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol below it. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## T.505 + +(11/94) + +### TERMINALS FOR TELEMATIC SERVICES + +--- + +**DOCUMENT APPLICATION PROFILE PM-26 +FOR THE INTERCHANGE OF ENHANCED +STRUCTURE, MIXED CONTENT DOCUMENTS +IN PROCESSABLE AND FORMATTED FORMS** + +### ITU-T Recommendation T.505 + +(Previously "CCITT Recommendation") + +--- + +# FOREWORD + +The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). + +ITU-T Recommendation T.505 was prepared by ITU-T Study Group 8 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 11th November 1994. + +# --- NOTE + +In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +© ITU 1995 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +# CONTENTS + +Page + +| | | | +|---|--------------------------------------------------------------------------------------------|----| +| 1 | Scope..... | 1 | +| 2 | Normative references ..... | 1 | +| | 2.1 Paired Recommendations International Standards equivalent in technical content ..... | 1 | +| | 2.2 Additional references ..... | 3 | +| 3 | Definitions..... | 3 | +| 4 | Relationship with other Profiles ..... | 4 | +| 5 | Conformance ..... | 4 | +| | 5.1 Data stream conformance..... | 4 | +| | 5.2 Implementation conformance ..... | 5 | +| 6 | Characteristics supported by this document application profile..... | 5 | +| | 6.1 Overview ..... | 5 | +| | 6.1.1 General ..... | 5 | +| | 6.1.2 Formatted form documents..... | 5 | +| | 6.1.3 Processable form documents..... | 5 | +| | 6.1.4 Formatted processable form documents ..... | 6 | +| | 6.1.5 Generic-documents ..... | 6 | +| | 6.1.6 Document profile ..... | 6 | +| | 6.2 Logical characteristics..... | 7 | +| | 6.2.1 Introduction ..... | 7 | +| | 6.2.2 Overview of the logical structure..... | 7 | +| | 6.2.3 Body part of the logical structure..... | 7 | +| | 6.2.4 Common content part of the logical structure ..... | 11 | +| | 6.3 Layout characteristics..... | 12 | +| | 6.3.1 Overview of the layout characteristics ..... | 12 | +| | 6.3.2 DocumentLayoutRoot..... | 14 | +| | 6.3.3 PageSet..... | 14 | +| | 6.3.4 Page characteristics..... | 15 | +| | 6.3.5 Body area characteristics..... | 17 | +| | 6.3.6 Header and footer area characteristics ..... | 24 | +| | 6.3.7 GenericBlock and SpecificBlock ..... | 25 | +| | 6.4 Document layout characteristics ..... | 25 | +| | 6.4.1 Flow controls ..... | 26 | +| | 6.4.2 Layout of the document content..... | 28 | +| | 6.4.3 Layout controls applicable in the absence of a generic layout structure ..... | 30 | +| | 6.5 Content layout and imaging characteristics ..... | 30 | +| | 6.5.1 Character content..... | 30 | +| | 6.5.2 Raster graphics content ..... | 39 | +| | 6.5.3 Geometric graphics content..... | 41 | +| | 6.6 Miscellaneous features ..... | 41 | +| | 6.6.1 Resource-documents ..... | 41 | +| | 6.6.2 External documents ..... | 42 | +| | 6.6.3 Border..... | 42 | +| | 6.6.4 Application comments ..... | 42 | +| | 6.6.5 Alternative representation..... | 42 | +| | 6.6.6 Automatic numbering mechanisms ..... | 43 | +| | 6.6.7 User readable comments ..... | 46 | +| | 6.6.8 User visible name..... | 46 | +| | 6.7 Document management features..... | 47 | +| | 6.7.1 Document constituent information ..... | 47 | +| | 6.7.2 Document identification information..... | 47 | +| | 6.7.3 Document default information..... | 48 | +| | 6.7.4 Non-basic characteristics information ..... | 48 | +| | 6.7.5 Fonts list..... | 50 | +| | 6.7.6 Document management attributes ..... | 50 | + +| | <i>Page</i> | +|-------------------------------------------------------------------------------|-------------| +| 7 Specification of constituent constraints..... | 46 | +| 7.1 Introduction..... | 46 | +| 7.1.1 Diagrams of relationships of logical constituents..... | 46 | +| 7.1.2 Diagrams of relationships of layout constituents..... | 46 | +| 7.1.3 Notation..... | 46 | +| 7.2 Document profile constituent constraints..... | 46 | +| 7.2.1 Macro definitions..... | 47 | +| 7.2.2 Constituents constraints..... | 48 | +| 7.3 Logical constituent constraints..... | 51 | +| 7.3.1 Macro definitions..... | 51 | +| 7.3.2 Factor constraints..... | 51 | +| 7.3.3 Constituent constraints..... | 52 | +| 7.4 Layout constituent constraints..... | 58 | +| 7.4.1 Macro definitions..... | 59 | +| 7.4.2 Factor constraints..... | 60 | +| 7.4.3 Constituent constraints..... | 61 | +| 7.5 Layout style constituent constraints..... | 81 | +| 7.5.1 Macro definitions..... | 81 | +| 7.5.2 Factor constraints..... | 81 | +| 7.5.3 Constituent constraints..... | 82 | +| 7.6 Presentation style constituent constraints..... | 83 | +| 7.6.1 Macro definitions..... | 83 | +| 7.6.2 Factor constraints..... | 83 | +| 7.6.3 Constituent constraints..... | 83 | +| 7.7 Content portion constituent constraints..... | 85 | +| 7.7.1 Macro definitions..... | 85 | +| 7.7.2 Factor constraints..... | 85 | +| 7.7.3 Constituent constraints..... | 85 | +| 8 Interchange format..... | 86 | +| 8.1 Interchange format..... | 86 | +| 8.2 Document application profile object identifier..... | 86 | +| 8.3 Encoding of application comments..... | 87 | +| 8.4 Data lengths..... | 87 | +| Annex A – Amendments and technical corrigenda..... | 87 | +| A.1 Amendments..... | 87 | +| A.1.1 Amendments to the base standard..... | 87 | +| A.1.2 Proposed changes to standards due to defects..... | 87 | +| A.2 Technical corrigenda..... | 87 | +| A.2.1 Technical corrigenda to this Recommendation..... | 87 | +| A.3 Versions of the ODA Specification..... | 87 | +| Annex B – Recommended practices..... | 88 | +| B.1 Transfer methods for ODA..... | 88 | +| B.1.1 Conveyance of ODA over CCITT Recommendation X.400-1984..... | 88 | +| B.1.2 Conveyance of ODA over FTAM..... | 88 | +| B.1.3 Conveyance of ODA over DTAM..... | 88 | +| B.1.4 Conveyance of ODA over flexible disks..... | 88 | +| B.2 Font reference..... | 88 | +| B.3 ISO/IEC 8632 (CGM) constraints for this document application profile..... | 89 | +| B.3.1 Delimiter elements..... | 89 | +| B.3.2 Metafile descriptor elements..... | 90 | +| B.3.3 Picture descriptor elements..... | 90 | +| B.3.4 Control elements..... | 91 | +| B.3.5 Graphical primitive elements..... | 91 | +| B.3.6 Attribute elements..... | 91 | +| B.3.7 External elements..... | 93 | +| Annex C – Bibliography..... | 94 | + +# **SUMMARY** + +This Recommendation specifies an ODA Document Application Profile (DAP) named PM-26. + +This Profile specifies an interchange format for the transfer of structured documents between equipments designed for word or document processing. Such documents may contain character, raster graphics and geometric graphics content. + +The documents that can be interchanged using this Profile range from simple documents to highly structured technical reports, articles and typeset documents such as brochures. This Profile provides a comprehensive level of features for the transfer of documents between these systems. + +A document structured in accordance with this Profile is represented for interchange by the Open Document Interchange Format (ODIF), as defined in Recommendation T.415. + +# INTRODUCTION + +This Recommendation specifies an ODA Document Application Profile (DAP) named PM-26. The purpose of this Profile is to facilitate the interworking of applications interchanging documents based on ODA, T.410 Series of CCITT Rec. | ISO/IEC 8613. This Profile is suitable for interchanging documents in formatted form, processable form or formatted processable form and has been defined in accordance with CCITT Rec. T.411\_|\_ISO/IEC 8613-1. The format of this Profile is in accordance with the standardized proforma and notation defined in Annex F of CCITT Rec. T.411\_|\_ISO/IEC 8613-1. + + + +# **DOCUMENT APPLICATION PROFILE PM-26** **FOR THE INTERCHANGE OF** **ENHANCED STRUCTURE, MIXED CONTENT DOCUMENTS** **IN PROCESSABLE AND FORMATTED FORMS<sup>1)</sup>** + +(Geneva, 1991; amended in Geneva, 1994) + +# 1 Scope + +This Profile specifies an interchange format for the transfer of structured documents between equipments designed for word or document processing. Such documents may contain character, raster graphics and geometric graphics content. + +The documents that can be interchanged using this Profile range from simple documents to highly structured technical reports, articles and typeset documents such as brochures. This Profile provides a comprehensive level of features for the transfer of documents between these systems. + +This Profile allows documents to be interchanged in the following forms: + +- formatted form; +- processable form; +- formatted processable form. + +The architecture levels defined for these three forms have matching functionalities so that the interchange formats of a document are convertible from a processable form to any other form. + +This Profile is independent of the processes carried out in an end system to create, edit or reproduce documents. It is also independent of the means to transfer documents which, for example, may be by means of communication links or storage media. + +A document structured in accordance with this Profile is represented for interchange by the Open Document Interchange Format (ODIF), as defined in CCITT Rec. T.415 | ISO/IEC 8613-5. + +# 2 Normative references + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. All Recommendations and other references are subject to revision; as a general rule, all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. However, users are warned against automatically applying any more recent editions of the Recommendations and other references listed below, since the nature of the references made by this Recommendation to such documents is that it may be specific to a particular edition. Members of IEC and ISO maintain registers of currently valid International Standards and ISPs, and ITU-T maintains published editions of its current Recommendations. + +## 2.1 Paired Recommendations | International Standards equivalent in technical content + +- CCITT Recommendation T.411 (1988), *Open Document Architecture (ODA) and interchange format – Introduction and general principles.* +ISO 8613-1:1989, *Information processing – Text and office systems – Office Document Architecture (ODA) and interchange format – Part 1: Introduction and general principles.* +- CCITT Recommendation T.411 Annex F (1991), *Open Document Architecture (ODA) and interchange format: Introduction and general principles – Annex F: Document Application Profile Proforma and Notation.* +ISO 8613-1 Add.1: *Information processing – Text and office systems – Office Document Architecture (ODA) and interchange format – Part 1: Introduction and general principles – Addendum 1: Document Application Profile Proforma and Notation.* + +<sup>1)</sup> Recommendation T.505 is technically aligned with ISO/IEC ISP 11181-1:1993. + +- CCITT Recommendation T.412 (1988), *Open Document Architecture (ODA) and interchange format – Document structures*. +ISO 8613-2:1989, *Information processing – Text and office systems – Office Document Architecture (ODA) and interchange format – Part 2: Document structures*. +- CCITT Recommendation T.414 (1988), *Open Document Architecture (ODA) and interchange format – Document profile*. +ISO 8613-4:1989, *Information processing – Text and office systems – Office Document Architecture (ODA) and interchange format – Part 4: Document profile*. +- CCITT Recommendation T.415 (1988), *Open Document Architecture (ODA) and interchange format – Open Document Interchange Format (ODIF)*. +ISO 8613-5:1989, *Information processing – Text and office systems – Office Document Architecture (ODA) and interchange format – Part 5: Office Document Interchange Format (ODIF)*. +- CCITT Recommendation T.416 (1988), *Open Document Architecture (ODA) and interchange format – Character content architectures*. +ISO 8613-6:1989, *Information processing – Text and office systems – Office Document Architecture (ODA) and interchange format – Part 6: Character content architecture*. +- CCITT Recommendation T.417 (1988), *Open Document Architecture (ODA) and interchange format – Raster graphics content architectures*. +ISO 8613-7:1989, *Information processing – Text and office systems – Office Document Architecture (ODA) and interchange format – Part 7: Raster graphics content architecture*. +- CCITT Recommendation T.418 (1988), *Open Document Architecture (ODA) and interchange format – Geometric graphics content architectures*. +ISO 8613-8:1989, *Information processing – Text and office systems – Office Document Architecture (ODA) and interchange format – Part 8: Geometric graphics content architecture*. +- CCITT Recommendation X.208 (1988), *Specification of Abstract Syntax Notation One (ASN.1)*. +ISO/IEC 8824:1990, *Information Technology – Open Systems Interconnection - Specification of Abstract Syntax Notation One (ASN.1)*. +- CCITT Recommendation X.209 (1988), *Specification of basic encoding rules for Abstract Syntax Notation One (ASN.1)*. +ISO/IEC 8825:1990, *Information technology – Open Systems Interconnection – Specification of basic encoding rules for Abstract Syntax Notation One (ASN.1)*. +- ITU-T Recommendation T.502 (1994), *Document application profile PM-11 for the interchange of simple structure, character content documents in processable and formatted forms*. +ISO/IEC ISP 10610-1:1993, *Information technology – International Standardized Profile FOD11 – Open document format: Simple document structure – Character content architecture only – Part 1: Document Application Profile (DAP)*. +- ITU-T Recommendation T.506 (1993), *Document application profile PM-36 for the interchange of extended document structures and mixed content documents in processable and formatted forms*. +ISO/IEC ISP 11182-1:1993, *Information technology – International Standardized Profile FOD36 – Open document format: Extended document structure – Character, raster graphics and geometric graphics content architectures – Part 1: Document Application Profile (DAP)*. +- CCITT Recommendation T.50 (1992), *International Reference Alphabet (IRA) – Information technology – 7-bit coded character set for information interchange*. +ISO/IEC 646:1991, *Information technology – ISO 7-bit coded character set for information interchange*. +- CCITT Recommendation T.51 (1992), *Latin based coded character sets for telematic services*. +ISO 6937:1994, *Information technology – Coded graphic character set for the communication of texts using the Latin alphabet*. + +## 2.2 Additional references + +- CCITT Recommendation T.4 (1988), *Standardization of group 3 facsimile apparatus for document transmission*. + +- CCITT Recommendation T.6 (1988), *Facsimile coding schemes and coding control functions for group 4 facsimile apparatus*. +- ISO 2022:1986, *Information processing – ISO 7-bit and 8-bit coded character sets – Code extension techniques*. +- ISO 2375:1985, *Data processing – Procedure for registration of escape sequences*. +- ISO/IEC 7350:1991, *Information technology – Registration of repertoires of graphic characters from ISO/IEC 10367*. +- ISO/IEC 8632:1992, *Information technology – Computer graphics – Metafile for the storage and transfer of picture description information* + - *Part 1: Functional specification*. + - *Part 3: Binary encoding*. +- ISO 8859-1:1987, *Information processing – 8-bit single-byte coded graphic character sets – Part 1: Latin alphabet No 1*. +- ISO 9293:1987, *Information processing – Volume and file structure of flexible disk cartridges for information interchange*. +- ISO/IEC 9541:1991, *Information technology – Font information interchange*. +- ISO/IEC TR 10000-1:1992, *Information technology – Framework and taxonomy of International Standardized Profiles – Part 1: Framework*. +- ISO/IEC TR 10000-2:1992, *Information technology – Framework and taxonomy of International Standardized Profiles – Part 2 Taxonomy of OSI profiles*. +- CCITT Recommendation T.400 (1988), *Introduction to document architecture, transfer and manipulation*. +- ISO/IEC ISP 11181-1:1993, *Information technology – International Standardized Profile FOD26 – Open Document Format : Enhanced document structure – Character, raster graphics and geometric graphics content architectures – Part 1: Document Application Profile (DAP)*. + +# 3 Definitions + +For the purposes of this Recommendation, the following definitions apply. The definitions given in CCITT Rec. T.411| ISO/IEC 8613-1 are applicable to this Profile. + +**constituent constraint names:** Each constituent that may be included in a document that conforms to this Profile has been given a unique name which serves to associate that constituent with a constituent constraint defined in this Recommendation. + +The convention is that full names are used (i.e., no abbreviations are used), two or more words in a name are concatenated and each word begins with a capital. Examples of constituent constraint names used in this Profile are BodyText, Footnote, RectoPage and ColumnFixed. + +In clause 6 each constituent constraint provided by this Profile is italicized once at the point in the text at which the purpose of that constituent constraint is defined. This also serves to identify all the constituent constraints provided by this Profile. + +The same constituent constraint names are also used in the technical specification in clause 7 so that there is a one-to-one correspondence between the use of these names in clauses 6 and 7. + +Although the constituent constraint names relate to the purpose of the constituent constraints, the semantics of constituents shall not be implied from the names that are used. Also, these names do not appear in an interchanged document but a mechanism for associating constituents in a document with constituent constraints is provided (see 6.6.4). Thus in an application using this Profile, the constituents may be known to the user by different names. + +# 4 Relationship with other Profiles + +This Profile belongs to a series of hierarchically related Profiles which include PM-11 and PM-36. + +The features supported by this Profile are a superset of the features supported by the Profile PM-11 and thus all data streams that are conformant to PM-11 are also conformant to this Profile, apart from the document application profile identifier. + +Also the features supported by this Profile are a subset of the features supported by the Profile PM-36 and thus all data streams conformant to this Profile are also conformant to PM-36, apart from the document application profile identifier. + +NOTE – This Profile is technically aligned with (but not identical to) the Specification defined in the ISO International Standardized Profile FOD26, except that FOD26 not only defines the use of the ODIF interchange format, but also the use of the SDIF interchange format. + +# 5 Conformance + +In order to conform to this Profile, a data stream representing a document shall meet the requirements specified in 5.1. + +This Recommendation does not define implementation or service requirements. + +## 5.1 Data stream conformance + +The following requirements apply to the encoding of data streams which conform to this Profile: + +- the data stream shall be encoded in accordance with the ASN.1 encoding rules defined in CCITT Rec. X.209 | ISO/IEC 8825; +- the data stream shall be structured in accordance with the interchange format defined in clause 8; +- the document, as represented by the data stream after resolution of any external references, shall be structured in accordance with one of the documents architecture classes as defined in 6.1 and shall contain all mandatory constituents specified for that class; other constituents may be included, provided that they are permitted for that class, as specified in clause 7; +- each constituent shall contain all those attributes specified as required for that constituent in this Profile; other attributes may be specified provided that they are permitted for that constituent; +- the attribute values specified shall be within the range of permissible values specified in this Profile; +- the encoded document shall be constructed in accordance with the abstract document architecture defined in CCITT Rec. T.412 | ISO/IEC 8613-2; +- the document shall be structured in accordance with the characteristics and constraints specified in clause 6. + +## 5.2 Implementation conformance + +This subclause states the requirements for implementations claiming conformance to this Profile. + +A conforming receiving implementation shall be capable of receiving any data streams conforming to this Profile structured in accordance with ODIF. Receiving usually, but not always, involves recognizing and further processing the data stream elements. + +A receiving system which claims conformance to this document application profile shall be capable of handling data streams which are conformant to document application profiles that are subordinate to this document application profile within the taxonomy described in clause 4, (i.e. PM-11). + +# 6 Characteristics supported by this document application profile + +This clause describes the characteristics of documents which may be represented by data streams conforming to this Profile. This clause also describes how these characteristics are represented in terms of constituent constraints. + +## 6.1 Overview + +### 6.1.1 General + +This Profile supports the interchange of documents in the following forms: + +- processable form, which facilitates the revision of a document by a recipient; +- formatted form, which facilitates the reproduction of a document as intended by the originator; +- formatted processable form, which facilitates the reproduction of a document as intended by the originator or facilitates the revision of a document by a recipient. + +In addition, this Profile supports the interchange of: + +- generic-documents; +- document profile. + +The constituents that make up these five classes of data stream are defined in 6.1.2 to 6.1.6. Constituents defined as *required* shall occur in any data stream that conforms to this Profile. Constituents listed as *optional* may or may not be present in the data stream depending on the requirements of the particular data stream. + +The constituents that make up a complete document that is conformant to this Profile include all those referenced and contained in resource-documents and external-documents, if any (see 6.6.1 and 6.6.2). + +### **6.1.2 Formatted form documents** + +Required constituents: + +- a document profile; +- layout object descriptions representing a specific layout structure. + +Optional constituents: + +- layout object class descriptions representing a factor generic layout structure; +- presentation styles; +- content portion descriptions. + +### **6.1.3 Processable form documents** + +Required constituents: + +- a document profile; +- logical object class descriptions representing a complete or partial generic logical structure; +- logical object descriptions representing a specific logical structure. + +Optional constituents: + +- layout object class descriptions representing a complete generic layout structure; +- layout styles; +- presentation styles; +- content portion descriptions. + +In the case of processable form documents, when the generic layout structure is not present, additional restrictions are placed on the layout directives that may be included in layout styles. These restrictions are defined in 6.4.3. + +### **6.1.4 Formatted processable form documents** + +Required constituents: + +- a document profile; +- logical object class descriptions representing a complete or partial generic logical structure; +- logical object descriptions representing a specific logical structure; +- layout object class descriptions representing a complete generic layout structure; +- layout object descriptions representing a specific layout structure. + +Optional constituents: + +- layout styles; +- presentation styles; +- content portion descriptions. + +### **6.1.5 Generic-documents** + +A generic-document consists of one of the following sets of constituents: + +- a) + - a document profile; + - logical object class descriptions which represent a complete or partial generic logical structure; + - layout styles whose presence is optional; + - presentation styles whose presence is optional; + +- generic content portions whose presence is optional. +- b) – a document profile; + - layout object class descriptions which represent a complete generic layout structure or factor set; + - presentation styles whose presence is optional; + - generic content portions whose presence is optional. +- c) – a document profile; + - logical object class descriptions which represent a complete or partial generic logical structure; + - layout object class descriptions which represent a complete generic layout structure; + - layout styles whose presence is optional; + - presentation styles whose presence is optional; + - generic content portions whose presence is optional. + +### 6.1.6 Document profile + +This form of document contains a document profile only. + +## 6.2 Logical characteristics + +### 6.2.1 Introduction + +This subclause defines the constituent constraints for logical components which are provided by this Profile to represent the characteristics of documents containing logical component descriptions. + +Different constituent constraints may be used to represent and distinguish parts of a document that have different logical characteristics. This subclause describes the general characteristics and typical uses of the constituent constraints that are provided. + +The descriptions of the logical characteristics represented by each of the constituent constraints is provided for guidance only. It is the responsibility of the user to determine how a document is to be represented using the constituents provided. Adherence to these guidelines can enhance the mutual understanding of a document by an originator and a recipient. + +### 6.2.2 Overview of the logical structure + +From the logical point of view, the document consists of two parts, namely a body part and a common part. + +The body part represents the main content of a document and is intended to be reproduced in the body area of the pages that make up the document. + +The common part represents common content that is to be placed in reserved header and footer areas on each page of a document. Header and footer content are independently optional and so may be included in an interchanged document only if required. + +### 6.2.3 Body part of the logical structure + +#### 6.2.3.1 DocumentLogicalRoot + +*DocumentLogicalRoot* is a constituent constraint representing the top level in the document logical structure. Its immediate subordinates consist of a sequence of one or more constituent constraints of the type *Passage*. + +The automatic numbering schemes that apply to constituent constraints of the types *NumberedSegment* and *Footnote* may be initialised on the *DocumentLogicalRoot*. + +#### 6.2.3.2 Passage + +*Passage* is a constituent constraint that represents the first level of logical subdivision of a document. It may be used to indicate a logical grouping of subordinate parts of a document that are to be regarded as an entity for reading or that have common layout and presentation characteristics. + +Passages are typically used to represent: + +- the contents to be placed on the title page of a report; +- the front matter in the table of contents or foreword; +- the main matter of the document; + +- the back matter, consisting of appendices, glossary or index. + +The automatic numbering schemes that apply to subordinate constituent constraints of the types `NumberedSegment` and `Footnote` may be initialised on a `Passage`. + +The immediate subordinates of a `Passage` consist of an optional arbitrary ordered sequence of one or more of the following constituent constraint types: + +- `Paragraph`; +- `BodyGeometric`; +- `BodyRaster`; +- `BodyText`. + +These may be optionally followed by one or more constituent constraints of the type `NumberedSegment`. + +A `Passage` shall have at least one of the above constituent constraint types as a subordinate. + +A document may contain several different class definitions of the type `Passage`, each of which defines the common characteristics of sets of `Passages` within the document such as their allowed subordinates or layout properties. For example, a class of `Passages` may be defined which always begin on a new page set. + +#### 6.2.3.3 `NumberedSegment` + +*NumberedSegment* is a constituent constraint that represents a logical subdivision within a document that is distinguished by an identifier. The logical subdivision may be a subdivision of a `Passage` or another higher level `NumberedSegment`. The logical subdivision may also have some common layout characteristics. + +The automatic numbering schemes that apply to subordinate constituent constraints of the types `NumberedSegment` and `Footnote` may be initialised on a `Passage`. + +The immediate subordinates of a `NumberedSegment` consist of the constituent constraint `Number`, whose presence is mandatory and serves to carry the identifier of the `NumberedSegment`. This is followed by an optional arbitrary ordered sequence of one or more of the following constituent constraints: + +- `Paragraph`; +- `BodyGeometric`; +- `BodyRaster`; +- `BodyText`. + +These are optionally followed by a sequence of one or more constituent constraints of the type `NumberedSegment`. Hence a document may contain any number of nested levels of the `NumberedSegment` constituents. + +A `NumberedSegment` is typically used to represent entities such as chapters, sections, nested sub-sections and appendices which contain an identifier that serves to distinguish that entity for human comprehension. + +A document may contain any number of different class definitions of `NumberedSegment` which define the common characteristics of sets of `NumberedSegments`, such as their allowed subordinates and layout properties. + +Class definitions of `NumberedSegments` may be recursively defined. In this case only one call of `NumberedSegment` may be specified, and the `<simple-expr>` construction in the macro `USENUMBERSTRINGS` in the bindings attribute of this class shall use the optional `ORD` construction only. If the recursive class definitions are used for `NumberedSegment`, the following constraints shall also apply. For all levels which reference recursively defined classes: + +- numbering format shall be the same; +- no initial value other than 1 or re-initialisation of the numbering is possible; +- it is not possible to continue the numbering across `Passages`. + +If class definitions are not recursive in this way, there shall be one and only one class definition for `NumberedSegments` corresponding to each level of numbering within each `Passage`. Class definitions may be shared between `NumberedSegments` belonging to different `Passages` but they shall then be used at the same level. + +#### 6.2.3.4 `Number` + +*Number* is a constituent constraint that represents the identifier of a `NumberedSegment` to which it is subordinate. This identifier allows the `NumberedSegment` to be distinguished within the document for machine processing or human comprehension. + +A Number defines a basic logical constituent which contains a content generator which, when evaluated, produces the identifier referred to above. This evaluation takes place during the layout process. + +The identifiers are structured and consist of a sequence of one or more numerals that allow NumberedSegments at the same or different levels in a document structure to be uniquely distinguished. The numerals may be represented by Arabic or Roman numerals or by their alphabetic equivalent in lower or upper case characters (the number 1 is represented by “A”, etc.). Each numeral in an identifier is distinguished by means of separator characters such as spaces and full stops (the character “period”); a typical example is “6.2.3.4”. + +NOTE – The separator may be an empty string. + +Further details of the structure and generation of the identifiers are given in 6.6.6.2. + +#### **6.2.3.5 Paragraph** + +*Paragraph* is a constituent constraint that is a subdivision of a Passage or NumberedSegment. It is typically used to represent the grouping of parts of a document that deals with a single theme or topic. These parts may consist of character, raster graphics and geometric graphics content. + +The immediate subordinates of a Paragraph consist of an arbitrary ordered sequence of one or more of the following constituent constraints: + +- BodyText; +- BodyRaster; +- BodyGeometric; +- Footnote. + +Content from any subordinate basic text objects within a paragraph may be run on one from another (that is, to continue on the same line) by use of the Concatenation feature (see 6.4.2.5). Alternatively, content from subordinates of a paragraph may be separated one from another to give white space between them, using Separation (see 6.4.2.2). This may be used to give an effect similar to that achieved with empty lines of text. Use of empty text lines to achieve white space between areas of text or other content may lead to unintended blank areas adjacent to the leading edge of layout objects (e.g., at page breaks) whereas the use of Separation avoids this. + +Constituents of the type BodyText may be concatenated to form a continuous stream of character content which is laid out as a single unit. Sequences of constituents of the types BodyText and Footnote may be concatenated to represent a stream of character content with embedded footnotes. Multiple embedded footnotes, which may be consecutive without intervening text, may be included in the content. + +Another typical use of a Paragraph is to represent a group of document parts that have common layout characteristics. An example is a graphical illustration with associated text which is to be laid out in a particular frame. + +#### **6.2.3.6 BodyText, BodyRaster and BodyGeometric** + +*BodyText*, *BodyRaster* and *BodyGeometric* are constituent constraints which represent the lowest level of logical subdivision of a document. These constituent constraints are subdivisions of Passages, NumberedSegments and Paragraphs. They allow the layout and presentation requirements of different parts of a document to be specified. + +These are basic logical constituents that directly refer to content portions that contain character, raster graphics and geometric graphics content respectively. BodyText in the specific logical structure shall refer to one or more content portions each containing processable, formatted or formatted processable character content. BodyRaster and BodyGeometric shall only refer to a single content portion containing formatted processable raster graphics content or formatted processable geometric graphics content respectively. + +Constituents of these types in the generic logical structure may refer to generic content. This provides the means of defining common content within the body part of a document. + +#### **6.2.3.7 Footnote** + +*Footnote* is a constituent constraint that is a subdivision of a Paragraph and is used to represent footnotes within a document. + +A footnote is an amount of content that is logically associated with a particular part of the document body but which is intended to be read and laid out separately from its associated part of the document. Typically, a footnote consists of a footnote identifier, which is embedded within the document body, and the footnote itself, which is laid out elsewhere. + +A Footnote defines a composite logical constituent whose immediate subordinates consist of the constituent constraint FootnoteReference, which represents the footnote identifier, followed by the constituent constraint FootnoteBody, which represents the footnote itself. Both of these subordinates are mandatory. + +#### 6.2.3.8 FootnoteReference + +*FootnoteReference* defines a constituent constraint that is used to represent a footnote reference within the body of a document. + +FootnoteReference defines a basic logical constituent that contains a content generator which when evaluated produces a character string which constitutes the footnote reference referred to above. + +The generated character string consists of a label with optional prefix and suffix character strings. The label is used to uniquely identify a particular footnote and may consist of a number which is represented in the form of Arabic or Roman numerals or by an alphabetic equivalent. The number may be automatically generated so that its value is incremented for each successive footnote. Alternatively, the label may consist of a user defined character string. + +In a sequence of footnotes, automatic and user defined labels may be freely mixed (giving for example the sequence 1, 2\*, 3, 4). If the label consists of a user-defined character string, the automatically generated number sequence is not incremented. + +An example of a footnote reference is '(2)' where '(' and ')' are user defined prefix and suffix strings respectively and '2' is the automatically generated label. Another example is 'note<sup>5</sup>' where '5' is the label and 'note' is a prefix string which also contains the control function PLU to enable the label to be represented in the form of a superscript. In this case, a suffix string containing the control function PLD would be required to cause the superscripting to be cancelled before the following text. + +The format of the content generator referred to above is described in 6.6.6.3. + +#### 6.2.3.9 FootnoteBody + +*FootnoteBody* is a constituent constraint which represents the content of a footnote. + +FootnoteBody defines a composite logical constituent whose subordinates consist of a FootnoteNumber constituent, which is mandatory and represents the footnote identifier, followed by a sequence of one or more FootnoteText constituents which represents the footnote content. The identifier referred to above is identical to the corresponding footnote identifier which is embedded in the content of the document body and represented by the constituent constraint FootnoteReference. + +The constituents subordinate to FootnoteBody are intended to be laid out separately from the other parts of the document content. When a generic layout structure is specified for the document, these constituents are constrained to be laid out in a FootnoteArea frame (see 6.3.5.9). + +#### 6.2.3.10 FootnoteNumber + +*FootnoteNumber* is a constituent constraint that represents the footnote identifier within the footnote body. + +This identifier is identical to the content associated with the constituent constraint FootnoteReference but is intended to be laid out so that it immediately precedes the content of the footnote body. + +FootnoteNumber defines a basic logical constituent that contains a content generator which when evaluated produces the identifier referenced above. The format of this content generator is the same as the content generator that may be specified for the constituent constraint FootnoteReference. + +It is required to specify the attribute "layout category" with the value 'Footnote' for this constituent. This along with the attribute "permitted categories" with the value 'Footnote' on the footnote frame will ensure that this constituent is laid out in a FootnoteArea frame when generic layout structure is specified within the document. + +#### 6.2.3.11 FootnoteText + +*FootnoteText* is a constituent constraint that is used to represent the footnote content. It is the lowest logical subdivision of a FootnoteBody. + +FootnoteText defines a basic logical constituent that references one or more content portions each containing processable, formatted or formatted processable character content. + +It is required to specify the attribute "layout category" with the value 'Footnote' for this constituent. This along with the attribute "permitted categories" with the value 'Footnote' on the footnote frame will ensure that this constituent is laid out in a FootnoteArea frame when generic layout structure is specified within the document. + +### **6.2.4 Common content part of the logical structure** + +#### **6.2.4.1 CommonContent** + +*CommonContent* is a constituent constraint that represents common content that is to be laid out in the header and footer areas of the pages of a document. Common content consists of any combination of character, raster graphics and geometric graphics content. + +Any number of constituent constraints of the type *CommonContent* may be contained in a document. *CommonContent* is a composite logical object class whose immediate subordinates consist of an arbitrary ordered sequence of one or more of the following constituent constraints: + +- *CommonText*; +- *PageNumber*; +- *CommonRaster*; +- *CommonGeometric*. + +When the generic layout structure is present, constituents of the type *CommonContent* and their associated subordinate constituents are constrained to be laid out in frames representing header or footer areas using the logical source mechanism (see 6.3.6). + +#### **6.2.4.2 CommonText** + +*CommonText* is a constituent constraint that represents the common character content that is to be laid out in the header or footer area of a document. For example, header or footer content that appears on each page in a sequence of pages may be represented by this constituent constraint. + +*CommonText* is a constituent constraint for a basic logical object class that references one or more content portions each containing character content in a processable, formatted or formatted processable form. + +#### **6.2.4.3 PageNumber** + +*PageNumber* is a constituent constraint that represents the common character content that is to be laid out in the header or footer area of a document. This constituent constraint is specifically used when it is required to present a header or footer content which contains an automatically generated page number. + +*PageNumber* is a basic logical object class that contains a content generator. This content generator contains a reference to a page number which is automatically evaluated when the document is laid out. This provides the means of representing the page numbers that are displayed on the consecutive pages of a document. + +Each page number consists of a single number which may be represented in the form of Arabic or Roman numerals or in its alphabetic equivalent. Page numbering schemes may start at 0 or any value greater than 0, at the document root or pageset levels. + +The format of the content generators is defined in 6.6.6.1. + +#### **6.2.4.4 CommonRaster** + +*CommonRaster* is a constituent constraint that represents the common raster graphics content that is to be laid out in the header or footer area of a document. For example, this constraint may be used to represent a logo which is to be laid out on each page of a document. + +*CommonRaster* is a basic logical object class which references a single content portion containing formatted processable raster graphics content. + +#### **6.2.4.5 CommonGeometric** + +*CommonGeometric* is a constituent constraint that represents the common geometric graphics content that is to be laid out in the header or footer area of a document. For example, this constraint may be used to represent a graphical icon which is to be laid out on each page of a document. + +*CommonGeometric* is a constituent constraint for a basic logical object class which refers to a single content portion containing formatted processable geometric graphics content. + +## **6.3 Layout characteristics** + +This subclause defines the constituent constraints for layout components which are provided by this Profile to represent the characteristics of documents. + +Different constituent constraints may be used to represent and distinguish parts of a document that have different layout characteristics. This subclause describes the general characteristics and typical uses of the constituent constraints that are provided. + +The descriptions of the layout characteristics represented by each of the constituent constraints is provided for guidance only. It is the responsibility of the user to determine how a document is to be represented using the constituents provided. Adherence to these guidelines can enhance the mutual understanding of a document by an originator and a recipient. + +### 6.3.1 Overview of the layout characteristics + +The document structure allows the document content to be laid out and presented in one or more page sets. Each page set may be used for different parts of the document, for example, the title page, foreword, table of contents, document body and appendices. + +Each page set consists of a series of pages. In general, each page may be sub-divided into three areas: the body area, which is used to layout the document body; and the header and footer areas, which may be used to layout the common content. + +Four page layout types are provided by this Profile. Each page layout type specifies how the body, header and footer areas are positioned within each page and how the content may be presented within each of those areas. These four types are referred to as page layouts A, B, C and D and are illustrated in Figures 1, 2, 3 and 4 respectively. + +![Diagram of Page layout type A showing HeaderArea, BodyArea, and FooterArea with Character Path (CP) and Line Progression (LP) arrows.](8592a32c2fdf17c1e562f0ba6b7e8e1a_img.jpg) + +The diagram illustrates the layout of a page, labeled 'Page' at the top. It is divided into three main sections: HeaderArea, BodyArea, and FooterArea. Each section contains arrows indicating the flow of content. In the HeaderArea, a vertical arrow labeled 'Layout path' points down, and a horizontal arrow labeled 'CP' (Character Path) points right, with a vertical arrow labeled 'LP' (Line Progression) pointing down. In the BodyArea, a horizontal arrow labeled 'CP' points right, a vertical arrow labeled 'LP' points down, and a vertical arrow labeled 'Layout path' points down. In the FooterArea, a vertical arrow labeled 'Layout path' points down, a horizontal arrow labeled 'CP' points right, and a vertical arrow labeled 'LP' points down. The diagram is identified by the code T0810610-92/d01. + +CP Character Path +LP Line Progression + +Diagram of Page layout type A showing HeaderArea, BodyArea, and FooterArea with Character Path (CP) and Line Progression (LP) arrows. + +FIGURE 1/T.505 +Page layout type A + +![Diagram of Page layout type B showing HeaderArea, BodyArea, and FooterArea with layout paths and character/line progression directions.](9c6461e1e94afae4dec455e69a2ce152_img.jpg) + +The diagram illustrates the layout of a page (Page) divided into three main sections: HeaderArea, BodyArea, and FooterArea. The layout path (LP) and character path (CP) are indicated by arrows. + +- HeaderArea:** The layout path (LP) is vertical, pointing downwards. The character path (CP) is horizontal, pointing to the right. +- BodyArea:** The layout path (LP) is vertical, pointing upwards. The character path (CP) is horizontal, pointing to the right. +- FooterArea:** The layout path (LP) is vertical, pointing downwards. The character path (CP) is horizontal, pointing to the right. + +CP Character path +LP Line progression + +T0810620-92/d02 + +Diagram of Page layout type B showing HeaderArea, BodyArea, and FooterArea with layout paths and character/line progression directions. + +FIGURE 2/T.505 +Page layout type B + +![Diagram of Page layout type C showing HeaderArea, BodyArea, and FooterArea with layout paths and character/line progression directions.](2b3a967f6ce4f23649be995a353e39f8_img.jpg) + +The diagram illustrates the layout of a page (Page) divided into three main sections: HeaderArea, BodyArea, and FooterArea. The layout path (LP) and character path (CP) are indicated by arrows. + +- HeaderArea:** The layout path (LP) is vertical, pointing downwards. The character path (CP) is horizontal, pointing to the right. +- BodyArea:** The layout path (LP) is vertical, pointing upwards. The character path (CP) is horizontal, pointing to the right. +- FooterArea:** The layout path (LP) is vertical, pointing downwards. The character path (CP) is horizontal, pointing to the right. + +CP Character path +LP Line progression + +T0810630-92/d03 + +Diagram of Page layout type C showing HeaderArea, BodyArea, and FooterArea with layout paths and character/line progression directions. + +FIGURE 3/T.505 +Page layout type C + +![Diagram of Page layout type D showing three vertical areas: FooterArea, BodyArea, and HeaderArea. Each area contains a 'Layout path' arrow pointing left and a 'CP' (Character path) arrow pointing down. A legend below the diagram defines CP as Character path and LP as Line progression. The identifier T0810640-92/d04 is also present.](b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg) + +CP Character path +LP Line progression + +T0810640-92/d04 + +Diagram of Page layout type D showing three vertical areas: FooterArea, BodyArea, and HeaderArea. Each area contains a 'Layout path' arrow pointing left and a 'CP' (Character path) arrow pointing down. A legend below the diagram defines CP as Character path and LP as Line progression. The identifier T0810640-92/d04 is also present. + +FIGURE 4/T.505 +**Page layout type D** + +It is intended that all applications which use this Profile shall support page layout A, whereas support for the other three page layouts may be specified as optional. + +Page layout A is used when the character content is to be laid out horizontally (from left to right or from right to left) and from top to bottom within the body area. This layout is typically used for documents written in Latin based, Hebrew and Arabic languages. + +Page layout B is used when the character content is to be laid out vertically bottom to top or top to bottom and from left to right within the body area. This layout is typically used for documents written in Latin based, Hebrew and Arabic languages in which it is required to layout the content in landscape orientation within the body area of the page. + +Page layouts C and D are used when the character content is to be laid out from top to bottom and from right to left within the body area. These layouts are typically used in documents written in languages which use ideograms, such as Japanese and Chinese characters. + +The body area may be further sub-divided into areas composed of single and multiple columns and an area may be reserved for footnotes. In addition, the header and footer areas may be sub-divided to allow the representation of different content types. + +### 6.3.2 DocumentLayoutRoot + +*DocumentLayoutRoot* is a constituent constraint that represents the top level in the document layout structure. Its immediate subordinates consist of a sequence of one or more constituents of the type PageSet. The numbering schemes for pages may be initialised on this constituent constraint. + +### 6.3.3 PageSet + +*PageSet* is a constituent constraint that represents a grouping of pages within a document. A PageSet is typically used to represent a part of a document that has different layout requirements from other parts of a document. Also, a PageSet may correspond to a part of a document that has a certain logical significance, for example, a PageSet might represent the front matter in a document or an individual chapter. + +Only one level of PageSet is allowed in a document. However, a document may contain any number of class definitions of the type PageSet which may be used, for example, to provide a choice of alternative layouts for different parts of a document or to specify the exact layout requirements for each successive part of a document. + +The immediate subordinates of a PageSet consist of a combination of constituent constraints of the types Page, RectoPage and VersoPage, as described in 6.3.4.1. + +### 6.3.4 Page characteristics + +#### 6.3.4.1 Page constituents + +Three constituent constraints are provided to represent the pages within a document, namely *Page*, *RectoPage* and *VersoPage*. + +The only difference in the characteristics of these types of constituent constraints concerns the values that may be specified for the parameter “side of sheet” in the attribute “medium type”. In the case of Page, this parameter may be specified with the value ‘recto’, ‘verso’ or ‘unspecified’. In the case of RectoPage, this parameter may be specified with the value ‘recto’ or ‘unspecified’; in the case of VersoPage, this parameter may be specified with the value ‘verso’ or ‘unspecified’. The values ‘recto’ and ‘verso’ of the parameter “side of sheet” of the attribute “medium type” are non-basic. + +The pages that make up a page set consist of an optional initial page which is represented by the constituent constraint Page and which is optionally followed by either: + +- A sequence of pages represented by the constituent constraint Page. All pages in this sequence shall have the same layout characteristics but these characteristics may differ from those of the initial page. +- A sequence of pages which are intended to be laid out alternatively on the recto and verso (or on the verso and recto) sides of the presentation medium and are represented by the constituent constraints RectoPage and VersoPage respectively. All pages in this sequence shall have the same layout characteristics but these characteristics may differ from those of the initial page. + +Pages having the same layout characteristics are pages that have the same page layout (see 6.3.4.5) and for which the body area, header area (if present) and footer area (if present) have the same dimensions and positions within the page (see 6.3.4.3). Pages having the same layout characteristics do not necessarily have the same position on the presentation medium (see 6.3.4.4). + +A page set shall contain at least one page. + +An initial page is typically used at the beginning of a document or of a section within a document. It may be used, for example, for a title page whose layout requirements differ from the following pages. + +The following restrictions also apply to the pages within a page set: + +- all the pages shall have the same dimensions and orientation (see 6.3.4.2); +- all pages shall be laid out on the same size of presentation medium (see 6.3.4.3). + +#### 6.3.4.2 Page dimensions + +The dimensions of the pages may be specified as any value (in BMUs) that is equivalent to or less than ISO A3 or ANSI B paper sizes in portrait or landscape orientation. The dimensions may be specified in portrait or landscape orientation. Japanese page sizes B4 and B5 are also supported but the dimensions of these pages lie within the range of dimensions given above. + +Dimensions equivalent to or less than the common assured reproduction area of ISO A4 and ANSI A in portrait or landscape orientation are basic values. Larger page sizes are non-basic and their use shall be indicated in the document profile. + +Any default page dimensions may be specified in the document profile subject to the maximum dimensions defined above. + +NOTE – The size termed *North American Letter (NAL)* in CCITT Rec. T.410 series | ISO/IEC 8613, clause 7 is called *ANSI A* in this Recommendation to be consistent with the other references to ANSI standard paper sizes. + +#### 6.3.4.3 Nominal page sizes + +The nominal page sizes that may be specified are listed in Table 1. These may be specified in portrait or landscape orientation. All values of nominal page size are non-basic and hence all values used in a document shall be indicated in the document profile. + +Any value of nominal page size defined in Table 1, subject to the restrictions specified above, may be specified as the default value in the document profile. + +Table 1 also includes the recommended Assured Reproduction Area (ARA). Information loss may occur when a document is reproduced if the dimensions of constituent constraints of the type page exceed the ARA for the specified nominal page size. + +TABLE 1/T.505 +Nominal page sizes + +| Page type | Size in inches or millimetres | Size in BMUs | ARA in BMUs | +|--------------|-------------------------------|-----------------|-----------------| +| ISO A5 | 148 mm × 210 mm | 7 015 × 9 920 | Not defined | +| ISO A4 | 210 mm × 297 mm | 9 920 × 14 030 | 9 240 × 13 200 | +| ISO A3 | 297 mm × 420 mm | 14 030 × 19 840 | 13 200 × 18 480 | +| ANSI legal | 8.5 in. × 14 in. | 10 200 × 16 800 | 9 240 × 15 480 | +| ANSI A | 8.5 in. × 11 in. | 10 200 × 13 200 | 9 240 × 12 400 | +| ANSI B | 11 in. × 17 in. | 13 200 × 20 400 | 12 744 × 19 656 | +| Japan-legal | 257 mm × 364 mm | 12 141 × 17 196 | 11 200 × 15 300 | +| Japan-letter | 182 mm × 257 mm | 8 598 × 12 141 | 7 600 × 10 200 | + +#### 6.3.4.4 Page offset + +The page offset is the distance of the position of the left and top edges of the page relative to the left and top edges respectively of the presentation medium on which each page is reproduced. Any value of page offset may be specified provided that no part of the page area lies outside the area of the nominal page. Also, page offsets specified for the initial, recto and verso pages within a given page set may differ. The default page offset may be specified in the document profile. + +#### 6.3.4.5 Page layout characteristics + +##### 6.3.4.5.1 General characteristics + +Each page in a document may be subdivided into three rectangular areas, as follows: + +- a body area which is reserved for content that belongs to the body part of the document (see 6.3.5); +- a header area which is reserved for common header content (see 6.3.6); +- a footer area which is reserved for common footer content (see 6.3.6). + +The body area is mandatory and shall occur on every page in a document. The header and footer areas are both optional. + +Also, these three areas shall be entirely contained within the page area and shall not overlap. + +Four types of page layout are defined: + +##### 6.3.4.5.2 Page layout A + +For page layout A the header and footer areas are placed above and below the body area respectively. The layout paths in the header, body and footer areas are specified as 270°. This type of layout is illustrated in Figure 1. + +##### 6.3.4.5.3 Page layout B + +For page layout B the header and footer areas are placed above and below the body area respectively. The layout path in the body area is specified as 0°; in the header and footer areas the layout paths are specified as 270°. This type of layout is illustrated in Figure 2. + +##### 6.3.4.5.4 Page layout C + +For page layout C the header and footer areas are placed above and below the body area respectively. The layout path in the body area is specified as 180°; in the header and footer areas, the layout paths are specified as 270°. This type of layout is illustrated in Figure 3. + +##### 6.3.4.5.5 Page layout D + +For page layout D the header and footer areas are placed to the right and left of the body area respectively. The layout paths in the header, body and footer areas are all specified as 180°. This type of layout is illustrated in Figure 4. + +### 6.3.5 Body area characteristics + +#### 6.3.5.1 General characteristics + +The body area is the area within a page where the main matter of the document, that is the *body* part of the document, is laid out. + +The body area may consist of a single frame into which the content is directly laid out. In this case, the body area is represented by a BasicBody frame. + +Alternatively, the body area may be subdivided into different rectangular areas to provide for different layout requirements. In this case, the body frame is represented by a VariableCompositeBody frame. + +#### 6.3.5.2 BasicBody + +*BasicBody* is a constituent constraint which defines a lowest level frame into which content is directly laid out. + +The position and dimensions of this frame are fixed. The layout path specified depends upon the page layout type being used (see 6.3.4.5). + +#### 6.3.5.3 VariableCompositeBody + +*VariableCompositeBody* is a constituent constraint that defines a composite frame which contains one or more subordinate variably positioned frames. These subordinates are not pre-determined and are automatically adjusted during the layout process to accommodate the content that is allocated to them. For example, to provide for combinations of single or multiple column layout and the layout of footnotes. A VariableCompositeBody frame has a fixed position and fixed dimensions. The layout path specified for this frame depends upon the page layout type being used (see 6.3.4.5). + +The immediate subordinates of VariableCompositeBody frames consist of an arbitrary ordered sequence of one or more frames of the following constituent constraints: + +- BasicFloat; +- SnakingColumns; +- SynchronizedColumns. + +It may also contain a single frame of the type FootnoteArea. + +The subordinate frames are all variably positioned and may have variable dimensions. + +Thus the relative positions of these frames in the body area may vary and depend upon the positions of other frames (if any) that are placed in the same VariableCompositeBody frame. + +The layout path for VariableCompositeBody frames may be specified as 270°, 0° or 180°. This determines the page layout type used in the case where VariableCompositeBody represents the entire body area. + +Frames of the type BasicFloat, SnakingColumns and SynchronizedColumns are laid out along the layout path specified (in normal positioning fill order). FootnoteArea frames are laid out in the same direction as the body area layout path, but reverse fill order is used. + +These frames are constrained to have the same layout path as the VariableCompositeBody frame to which they are subordinate. An exception to this rule is made for frames of the type SnakingColumns (see subclause below). + +Figures 5, 6 and 7 provide illustrations of the layout of frames within a VariableCompositeBody frame for the various page layout types. + +A choice of subordinate frames of the types listed above may be specified for a VariableCompositeBody frame. Different frame types may be selected using various layout directives (see 6.4) and hence the layout characteristics of the body areas within a page set may change from page to page within a page set. + +![Diagram illustrating the layout path for a body area, showing the flow from the top of the page down through various content areas: SnakingColumns, ColumnVariable, BasicFloat, SynchronizedColumns, ColumnFixed, and FootnoteArea. The layout path is indicated by arrows, showing a top-to-bottom flow. The FootnoteArea frame has a 'reverse' positioning fill order.](c5452f95f3b28f1bfe29e84fbc2e1267_img.jpg) + +The diagram illustrates the layout path for a body area, showing the flow from the top of the page down through various content areas: + +- BodyArea**: The main container for the page content. +- SnakingColumns**: A container for columns that snake across the page. +- ColumnVariable**: A container for columns with variable widths. The layout path starts at the top, goes down, and then moves horizontally to the right. +- BasicFloat**: A container for basic floating elements. The layout path continues down from the previous section. +- SynchronizedColumns**: A container for columns that are synchronized. The layout path continues down from the previous section. +- ColumnFixed**: A container for columns with fixed widths. The layout path continues down from the previous section. +- FootnoteArea**: A container for footnotes. The layout path continues down from the previous section. A note indicates: "FootnoteArea frame has 'reverse' positioning fill order". + +The layout path is indicated by arrows, showing a top-to-bottom flow. The FootnoteArea frame has a 'reverse' positioning fill order. + +T0810650-92/d05 + +Diagram illustrating the layout path for a body area, showing the flow from the top of the page down through various content areas: SnakingColumns, ColumnVariable, BasicFloat, SynchronizedColumns, ColumnFixed, and FootnoteArea. The layout path is indicated by arrows, showing a top-to-bottom flow. The FootnoteArea frame has a 'reverse' positioning fill order. + +FIGURE 5/T.505 +Example of body area layout for page layout A + +![Diagram illustrating the layout of a body area. The BodyArea is divided into four main sections: SnakingColumns, BasicFloat, SynchronizedColumns, and FootnoteArea. SnakingColumns contains multiple ColumnVariable frames, each with a horizontal layout path. A vertical layout path is shown on the left of the SnakingColumns section. BasicFloat is a single column area with a horizontal layout path. SynchronizedColumns contains multiple ColumnFixed frames, each with a horizontal layout path. A horizontal layout path is shown at the bottom of the SynchronizedColumns section. FootnoteArea is a single column area with a horizontal layout path. A horizontal layout path is shown at the bottom of the FootnoteArea section. A horizontal layout path is also shown at the bottom of the entire BodyArea.](7133ccf78043568ca62ecbcd43628a4a_img.jpg) + +T0810660-92/d06 + +Diagram illustrating the layout of a body area. The BodyArea is divided into four main sections: SnakingColumns, BasicFloat, SynchronizedColumns, and FootnoteArea. SnakingColumns contains multiple ColumnVariable frames, each with a horizontal layout path. A vertical layout path is shown on the left of the SnakingColumns section. BasicFloat is a single column area with a horizontal layout path. SynchronizedColumns contains multiple ColumnFixed frames, each with a horizontal layout path. A horizontal layout path is shown at the bottom of the SynchronizedColumns section. FootnoteArea is a single column area with a horizontal layout path. A horizontal layout path is shown at the bottom of the FootnoteArea section. A horizontal layout path is also shown at the bottom of the entire BodyArea. + +FIGURE 6/T.505 +Example of body area layout for page layout B + +#### 6.3.5.4 BasicFloat + +*BasicFloat* is a constituent constraint that defines a lowest level frame that is used to represent a single column area within a body area. A single column area is typically used to layout content in the form of a single column. This is a variably positioned frame. + +The dimension of this frame in the direction orthogonal to the layout path of the body area is fixed or defaults to the maximum value allowed within the body area. + +The dimension of this frame in the direction parallel to the layout path of the body area is specified by sub-parameter “Rule-B”. This dimension is therefore automatically adjusted during the layout process to be the minimum required to contain all the content allocated to the frame. + +The layout path specified for this frame is the same as that specified for the body area. Content shall only be laid out in this frame in the direction of the layout path specified. + +#### 6.3.5.5 SnakingColumns + +*SnakingColumns* is a constituent constraint that defines a composite frame that represents a snaking columns area within a body area. A snaking columns area is typically used for the layout of one or more columns of content in which the content is allowed to flow freely from one column to the next. + +This frame is variably positioned. Its immediate subordinates consist of one or more frames of the type *ColumnVariable*. Examples of the layout of *SnakingColumns* frames are given in Figure 8. + +![Diagram illustrating the layout of a body area containing various subordinate frames. The main container is labeled 'BodyArea'. Inside, there are four main sections: 'FootnoteArea', 'SynchronizedColumns', 'BasicFloat', and 'SnakingColumns'. 'FootnoteArea' contains a 'Layout path' arrow pointing left. 'SynchronizedColumns' contains two 'ColumnFixed' frames, each with a 'Layout path' arrow pointing left. 'BasicFloat' contains a 'Layout path' arrow pointing left. 'SnakingColumns' contains two 'ColumnVariable' frames, each with a 'Layout path' arrow pointing left. A vertical 'Layout path' arrow points down between the 'ColumnVariable' frames. A horizontal 'Layout path' arrow points left at the bottom of the 'BodyArea' container.](cbdfdade780e677eb1c1aef3081ce9ef_img.jpg) + +Diagram illustrating the layout of a body area containing various subordinate frames. The main container is labeled 'BodyArea'. Inside, there are four main sections: 'FootnoteArea', 'SynchronizedColumns', 'BasicFloat', and 'SnakingColumns'. 'FootnoteArea' contains a 'Layout path' arrow pointing left. 'SynchronizedColumns' contains two 'ColumnFixed' frames, each with a 'Layout path' arrow pointing left. 'BasicFloat' contains a 'Layout path' arrow pointing left. 'SnakingColumns' contains two 'ColumnVariable' frames, each with a 'Layout path' arrow pointing left. A vertical 'Layout path' arrow points down between the 'ColumnVariable' frames. A horizontal 'Layout path' arrow points left at the bottom of the 'BodyArea' container. + +T0810670-92/d07 + +FIGURE 7/T.505 + +##### **Example of body area layout for page layouts C and D** + +The dimension of a SnakingColumns frame in the direction orthogonal to the layout path of the body area is fixed or defaults to the maximum value allowed within the body area. + +The dimension of this frame in the direction parallel to the layout path of the body area is specified by sub-parameter “Rule-B”. This dimension is therefore automatically adjusted to accommodate the subordinate frames which are laid out in it. + +The layout path for a SnakingColumns frame may be specified as 0° or 180° in the case of page layout A, 90° or 270° in the case of page layout B, and 270° in the cases of page layouts C and D. + +The attribute “balance” may be specified for a SnakingColumns frame to indicate that two or more of the subordinate ColumnVariable frames are to be approximately equal in length in the vertical dimension in the case of page layout A and are to be approximately equal in length in the horizontal dimension in the cases of page layouts B, C and D. Note that the term *approximately equal* in the context of the attribute “balance” means that the leading edges of the layout objects being balanced are aligned, as closely as possible, to a line orthogonal to the layout path for the objects. + +The attribute “balance” may be ignored when the subordinate ColumnVariable frames have unequal widths. + +![Diagrams illustrating the layout of snaking columns in three different page layouts (A, B, and C/D).](aaf3e6e44cdeabd6d1df869c5f392ea1_img.jpg) + +Page layout A + +VariableCompositeBody frame +SnakingColumns frame +ColumnVariable + +Block containing character content +Block containing graphics + +Page layout B + +VariableCompositeBody +SnakingColumns +ColumnVariable + +Page layouts C and D + +VariableComposit Body +SnakingColumns +ColumnVariable + +FLP Frame Layout Path +CP Character Path +LP Line Progression + +T0810680-92/d08 + +Diagrams illustrating the layout of snaking columns in three different page layouts (A, B, and C/D). + +FIGURE 8/T.505 +**Examples of the layout of snaking columns** + +#### 6.3.5.6 SynchronizedColumns + +*SynchronizedColumns* is a constituent constraint that defines a composite frame that represents a synchronized columns area within a body area. A synchronized columns area is typically used to represent one or more columns of content such that the content laid out in each column belongs to different layout streams. Thus content laid out in one column is not allowed to flow into the next column. + +This type of column layout is typically used when it is required to layout separate amounts of content in parallel with one another such that they are aligned. Examples are the synchronized layout of content belonging to different languages and the layout of a figure in parallel with some text. An example is shown in Figure 9. + +With regard to positioning and dimensioning, *SynchronizedColumns* frames have the same characteristics as *SnakingColumns* frames. + +The immediate subordinates of a *SynchronizedColumns* frame consist of any number of frames of the type *ColumnFixed*. + +The layout path for a *SynchronizedColumns* frame is 270° for page layout A, 0° for page layout B and 180° for page layouts C and D. + +![Diagram illustrating the layout of a SynchronizedColumns frame within a BodyArea. The diagram shows a BodyArea containing a SynchronizedColumns frame. Inside SynchronizedColumns are two ColumnFixed frames. The left ColumnFixed frame contains a BodyRaster and a Paragraph. The right ColumnFixed frame contains a BodyText and a Paragraph. Arrows indicate the layout path and synchronization alignment.](705ee99c3c44fd2a1ea6a3348ce8878f_img.jpg) + +The diagram illustrates the layout of a *SynchronizedColumns* frame within a *BodyArea*. The *BodyArea* contains a *SynchronizedColumns* frame. Inside the *SynchronizedColumns* frame are two *ColumnFixed* frames. The left *ColumnFixed* frame contains a *BodyRaster* and a *Paragraph*. The right *ColumnFixed* frame contains a *BodyText* and a *Paragraph*. Arrows indicate the layout path and synchronization alignment. + +Annotations in the diagram: + +- Blocks aligned along this line as specified by the attribute "synchronization" +- Alignment of two constituents of the type paragraph +- Layout path +- Layout path + +T0810690-92/d09 + +Diagram illustrating the layout of a SynchronizedColumns frame within a BodyArea. The diagram shows a BodyArea containing a SynchronizedColumns frame. Inside SynchronizedColumns are two ColumnFixed frames. The left ColumnFixed frame contains a BodyRaster and a Paragraph. The right ColumnFixed frame contains a BodyText and a Paragraph. Arrows indicate the layout path and synchronization alignment. + +FIGURE 9/T.505 + +Example of synchronized column layout for page layout A + +#### 6.3.5.7 ColumnVariable + +*ColumnVariable* is a constituent constraint that defines a lowest level frame that is used to represent a column of content within a *SnakingColumns* frame. This is a frame which is variably positioned. + +The dimension of this frame in the direction parallel to the layout path of the superior *SnakingColumns* frame (that is, the column width) is fixed. The dimensions of different instances of *ColumnVariable* frames within a given *SnakingColumns* frame may differ to allow columns of different widths to be specified. + +The dimension in the direction orthogonal to the layout path of the superior frame (that is, the column length) may be specified by the sub-parameters "Rule-B" or "maximum-size". + +The layout path for ColumnVariable frames is 270° in the case of page layout A, 0° in page layout B and 180° in page layouts C and D. + +All ColumnVariable frames subordinate to the same SnakingColumns frame shall have the same category name; different names may be used for ColumnVariable frames laid out in different SnakingColumns frames. + +#### **6.3.5.8 ColumnFixed** + +*ColumnFixed* is a constituent constraint that defines a lowest level frame that is used to represent a column of content within a SynchronizedColumns frame. This is a frame which has a fixed position. + +The dimension of this frame in the direction orthogonal to the layout path of the superior SynchronizedColumns frame (that is, the column width) may be specified by either of the sub-parameters “fixed dimension” or “maximum size” in all page layout types. This dimension may differ for different instances of ColumnFixed frames within a given SynchronizedColumns frame to allow columns of different widths to be specified. However, the widths shall be specified such that the columns do not overlap. + +The dimension of this frame in the direction parallel to the layout path of the superior frame (that is, the column length) may be specified by sub-parameters “Rule-B” or “maximum-size” in the cases of page layouts A and B. In the cases of page layouts C and D, this dimension shall only be specified as ‘maximum-size’. + +The ColumnFixed frames subordinate to a given SynchronizedColumns frame shall have different category names. + +The layout path for ColumnFixed frames shall be equal to the layout path of the superior SynchronizedColumns frame. + +The content laid out in different ColumnFixed frames within the same SynchronizedColumns frame may be specified synchronized by using the attribute “synchronization”. + +The sub-parameter “maximum size” shall only be specified for the right most ColumnFixed frames (relative to the page co-ordinate system) laid out in a SynchronizedColumns frame, to prevent overlapping of the frames. + +#### **6.3.5.9 FootnoteArea** + +*FootnoteArea* is a constituent constraint that defines a lowest level frame that is used to represent a footnote area within a body area. A footnote area is typically used for the layout of footnotes. + +Frames of this type are variably positioned with a positioning fill order specified as ‘reverse’. Hence this frame is positioned adjacent to the leading edge of the VariableCompositeBody frame. + +The dimension of FootnoteArea frames in the direction orthogonal to the layout path of its superior frame is specified by one of the sub-parameters “fixed dimension” or “maximum size”. In the direction of the layout path, the dimension is specified by sub-parameter “Rule-B” which means that this dimension is automatically adjusted to contain all the content that is allocated to it. + +The layout path for FootnoteArea frames is the same as that specified for the body area. + +The content that may be laid out in this frame is limited to the content that is associated with basic logical objects which are subordinates of the composite logical object FootnoteBody. To achieve this, the attribute “permitted categories” of this frame shall specify the value ‘Footnote’, the same name required on the basic logical objects for footnotes (see 6.2.3.10 and 6.2.3.11). + +### **6.3.6 Header and footer area characteristics** + +#### **6.3.6.1 General characteristics** + +The header and footer areas consist of either basic areas or composite areas. + +A basic header or footer area is an area into which the content is directly laid out. This type of area is represented by a constituent constraint of the type BasicHeader or BasicFooter respectively. + +A composite header or footer area is an area which is subdivided into separate sourced content and arranged content areas to provide greater versatility with regard to the layout of the content. This type of area is represented by a constituent constraint of the type CompositeHeader or CompositeFooter respectively. + +In the case of basic header or footer areas, the content allocated to these areas is derived from the common part of the logical structure of a document. In the case of composite header or footer areas, the content may again be derived from the common part of the logical structure of a document but the content may also be derived from common content specified in the generic layout structure. + +#### 6.3.6.2 BasicHeader and BasicFooter + +*BasicHeader* and *BasicFooter* are constituent constraints that define lowest level frames that represent areas within a page that are reserved for common content. + +These types of frame have fixed positions and dimensions. The positioning of these frames within a page and the layout paths that may be specified for them depends upon the page layout type used (see 6.3.4.5). + +The content that is laid out in these frames is derived, using the logical source mechanism, from the content associated with the composite logical object classes of the type *CommonContent*. + +#### 6.3.6.3 CompositeHeader and CompositeFooter + +*CompositeHeader* and *CompositeFooter* are constituent constraints that define composite frames that represent areas within a page that are reserved for common content. + +These types of frame have fixed positions and dimensions. The positioning of these frames within a page and the layout path that may be specified for them depends upon the page layout type used (see 6.3.4.5). + +The subordinates of these frames may consist of either: + +- a) any number and combination of variably positioned frames of the types *SourcedContentVariable* and *ArrangedContentVariable*; or +- b) any number and combination of fixed positioned frames of the types *SourcedContentFixed* and *ArrangedContentFixed*. + +In case b), the subordinate frames may overlap without restriction. + +#### 6.3.6.4 SourcedContentVariable + +A *SourcedContentVariable* frame is a constituent constraint that defines a lowest level frame that represents a region within a header or footer area that contains common content derived from the generic logical structure. This frame is variably positioned and its layout path is the same as that of the containing header or footer area. + +The dimension of this frame in the direction orthogonal to the layout path of the superior frame is specified by one of the sub-parameters “fixed dimension” or “maximum-size”. The dimension of the frame in the direction parallel to the layout path of the superior frame is specified by one of the sub-parameters “fixed dimension” or “Rule-B”. + +This frame is required to specify the attribute “logical source” which indicates the particular instance of the constituent constraint *CommonContent* which contains the content to be laid out in this frame. + +Typically, this frame is used for the positioning of content which is generated during the layout process, such as a character sequence containing a page number. + +#### 6.3.6.5 ArrangedContentVariable + +An *ArrangedContentVariable* frame is a constituent constraint that defines a lowest level frame that represents a region within a header or footer area that contains pre-defined common content contained in the generic layout structure. + +This frame is variably positioned and its dimensions are fixed. + +This frame refers to one or more blocks of type *GenericBlock* (see 6.3.7) which contain the content to be laid out in this frame. Thus, this frame is typically used when it is required to layout pre-determined common content. + +#### 6.3.6.6 SourcedContentFixed + +A *SourcedContentFixed* frame is a constituent constraint that defines a lowest level frame that represents a region within a header or footer area that contains common content derived from the generic logical structure. This frame has a fixed position and its layout path is equal to that of the containing header or footer area. + +The horizontal dimension of this frame is specified by the sub-parameter “fixed dimension”. The vertical dimension of this frame is specified by one of the sub-parameters “fixed dimension” or “Rule-B”. + +This frame is required to specify the attribute “logical source” which indicates the particular instance of the constituent constraint *CommonContent* which contains the content to be laid out in this frame. + +Thus, as in the case of *SourcedContentVariable* frames, this frame is used for the positioning of content which is generated during the layout process, such as a character sequence containing a page number. + +#### 6.3.6.7 ArrangedContentFixed + +An *ArrangedContentFixed* frame is a constituent constraint that defines a lowest level frame that represents a region within a header or footer area that contains pre-defined common content derived from the generic layout structure. + +The position and dimensions of this frame are fixed. This frame refers to one or several blocks of type *GenericBlock* (see 6.3.7) which contain the content to be laid out in this frame. Thus this frame is typically used when it is required to layout common content at pre-determined positions in the header or footer areas. + +### 6.3.7 GenericBlock and SpecificBlock + +Two types of constituent constraints of the object type ‘block’ are defined, namely *GenericBlock* and *SpecificBlock*. Object classes of the type *GenericBlock* may occur in the generic layout structure referred to by the attribute “generator for subordinates” of object classes of the types *ArrangedContentVariable* and *ArrangedContentFixed*. When the layout process is performed to produce a document in formatted processable form, equivalent blocks may occur in the specific layout structure. Objects of this type are restricted to occur within the header and footer areas of the page. + +Objects of the type *SpecificBlock* shall only occur in the specific layout structure. They are created during the document layout process and result from the layout of basic logical objects into lowest level frames that constitute the body, header and footer areas. + +## 6.4 Document layout characteristics + +Mechanisms for controlling the allocation of logical constituents to various areas in the layout structure are defined in 6.4.1. Mechanisms for controlling the layout of the content within the allocated areas are defined in 6.4.2. + +These mechanisms relate to documents for which a generic layout structure is specified. When a generic layout structure is not present, then these mechanisms are restricted as described in 6.4.3. + +### 6.4.1 Flow controls + +Various mechanisms are provided to control the allocation of constituent constraints representing the body parts of the logical structure of a document to pages sets, pages and body areas. These are described in 6.4.1.1, 6.4.1.2 and 6.4.1.3. The mechanisms for controlling the layout of the common parts of a document are described in 6.4.1.4. + +#### 6.4.1.1 Allocation of content to page sets + +Two methods of allocating the constituent constraints associated with the *body* part of the document to page sets are provided: + +- layout in a nominated page set; +- starting a new page set. + +The first method provides the ability to specify that a part of a document is to be laid out entirely within a specified page set. This may be specified for constituent constraints of the types *Passage*, *NumberedSegment* and *Paragraph* using the attribute “layout object class” which specifies the object class identifier of the required class of page set. + +The second method provides the ability to specify that the logical objects derived from a particular constituent constraint in a document and all subsequent parts of a document are to be laid out starting at the beginning of a new page set. This may be specified for the following constituent constraints: + +- *Passage*; +- *NumberedSegment*; +- *Paragraph*; +- *Number*; +- *BodyText*; +- *BodyRaster*; +- *BodyGeometric*. + +This is achieved using the attribute “new layout object” which specifies the object class identifier of the required class of page set. + +#### 6.4.1.2 Page breaks + +This provides the ability to specify that the logical objects derived from a particular constituent constraint in a document and all subsequent parts of a document are to be laid out starting at the beginning of a new page. The page specified shall + +belong to the page set in which the logical objects from the immediately preceding constituent constraint is laid out. The specification of a page break shall not be used to layout part of a document in a new page set. If a new page set is required, then this shall be explicitly specified as described in 6.4.1.1. + +This may be specified for the following constituent constraints: + +- Passage; +- NumberedSegment; +- Paragraph; +- Number; +- BodyText; +- BodyRaster; +- BodyGeometric. + +This is achieved using the attribute “new layout object”. This attribute may specify the value ‘page’ indicating that the constituent constraint is to be laid out starting on the next available page which may be of any class. Alternatively, the attribute may specify that the constituent constraint is to be laid out starting on a page of a particular class; this is achieved by specifying the object class identifier of the required page class. + +#### **6.4.1.3 Allocation of content to body areas** + +If the page to which the content is allocated contains a basic body area, then the content is laid out in sequential order in that body area in the form of a single column. + +If the page contains a composite body area, then the content is allocated to single, snaking and synchronized columns areas and footnote areas as described below. + +##### **6.4.1.3.1 Layout of content into column areas** + +When laying out content into a composite body area having more than one subordinate frame class (excluding FootnoteArea frame classes), it is necessary to indicate which of the column areas is to be used. + +Logical objects of the types Number, FootnoteReference, BodyText, BodyRaster and BodyGeometric may be specified to be laid out in instances of one or more single columns area, snaking columns area or synchronized columns area. + +This is done by giving each such basic logical component a value of the attribute “layout category” which corresponds to the value of the attribute “permitted categories” which applies to the lowest level of frame in which the content is to be laid out. + +Note that any basic logical objects in the specific logical structure to which this attribute does not apply will be laid out only in a lowest level frame which has the implicit value of the attribute “permitted categories”. + +The use of layout categories ensures that if there is insufficient area on one page to lay out all of the content allocated to a particular type of area, then the laying out of the content will automatically continue in the same type of area in a succeeding page. Thus content is allowed to flow freely from one page to the next when the type of layout used at the end of one page is the same as that at the beginning of the succeeding page. + +It is necessary to ensure the correct use of the mechanism for the layout of independent layout streams. In the absence of additional layout directives, content may be placed in available space within an earlier frame with appropriate values for the attribute “permitted categories”. If this is not intended, it may be prevented by the use of the attribute “new layout object”. + +The attribute “new layout object” may be applied to logical components of the types NumberedSegment, Paragraph, Number, FootnoteReference, BodyText, BodyRaster and BodyGeometric, whenever a change in column layout is required. + +The attribute “new layout object” may specify the identifier of the frame class that represents the single, snaking or synchronized column area required. In the case of single or synchronised column areas, the attribute “new layout object” may indicate the category name corresponding to the frame class of the single column area or of any of the columns within the synchronised column area that is required. + +When layout occurs in a snaking columns area, column breaks may be indicated by using the attribute “new layout object”. This attribute may specify the identifier or the category name of the frame corresponding to the column in which the layout is to continue. However only the use of a category name will ensure that a single column break is always obtained, irrespective of the frame class actually used. + +When the layout is to occur in a synchronized columns area, category names are used to control the particular columns that are to be used to layout the logical entities. Each column within a synchronized columns area shall have a different permitted category and each basic logical entity to be laid out in this particular area shall have a category name corresponding to a name allocated to one of the columns. The logical entities allocated to different columns may be aligned using the attribute “synchronization”. + +##### **6.4.1.3.2 Layout of footnotes** + +The basic logical objects derived from constituent constraints that represent the content belonging to a footnote (i.e FootnoteNumber and FootnoteText) are constrained to be laid out in a footnote area which is represented by a FootnoteArea frame (see 6.3.5.9). + +This constraint is specified by means of category names. That is, the logical constituents of the types FootnoteNumber and FootnoteText and layout constituents of the type FootnoteArea are all required to have the category name with the value ‘Footnote’. + +More than one footnote may be placed in a footnote area within a given body area. In this case the content belonging to the footnotes are laid out sequentially in the footnote area in accordance with their reading order. + +If the content belonging to a footnote cannot all be accommodated in the footnote area on one page, then the content may freely flow into the next footnote area on the subsequent page. Alternatively, it is possible to specify that a footnote is to be laid out entirely within a particular footnote area. This is achieved using the attribute “indivisibility”. + +#### **6.4.1.4 Allocation of content to header-footer areas** + +A header or footer area may be basic or composite (see 6.3.6.1). In the case of a basic area, the frame representing that area specifies the attribute “logical source” which indicates the particular instance of the constituent constraint of the type CommonContent that is to be laid out in that area. The basic logical constituents subordinate to CommonContent are then laid out in accordance with their sequential order. + +In the case of a composite header or footer area (see 6.3.6.3), the area is divided into one or more separate areas, each of which is represented by a lowest level frame. The content allocated to the separate areas may be derived from one of two sources. That is, the content may be pre-defined and represented by one or more blocks which are directly associated with the lowest level frame. Alternatively, the lowest level frame may specify the attribute “logical source” which, as above, indicates the particular logical object of the type CommonContent that is to be laid out in that frame. + +### **6.4.2 Layout of the document content** + +Various constraints may be specified to control the layout of the content into the body, header and footer areas. These constraints are described below. + +#### **6.4.2.1 Margins** + +The margins are the minimum distances, or offsets, between a part of the document content and the edge of the particular area in which that content is laid out. The margins define the maximum extents of the available area into which the content shall be positioned. + +Margins may be specified for any constituent constraint representing a basic logical object; different margin values may be specified for different constituent constraints without restriction. + +Four margins may be independently specified for each constituent constraint, namely: + +- trailing edge margin; +- leading edge margin; +- right hand edge margin; +- left hand edge margin. + +These margins are defined in relationship to the layout path specified for the frame in which the content is to be laid out in (see Figure 10). + +Any combination of the above margins may be specified for a particular constituent constraint. These margins are specified by the attribute “offset”. Any value may be specified in units of BMUs. If a particular margin is not specified, then it is assumed to be 0 BMUs. + +#### **6.4.2.2 Separation** + +Leading separation is the minimum distance between one basic logical object and the next one, if any, when they are laid out; trailing separation is the minimum distance between one basic logical object and the previous one, if any, when they + +are laid out. Both may be specified for basic logical components of any constituent constraint types. These distances are specified in BMUs by the attribute “separation”. If no value is specified, then the minimum distance is assumed to be 0 BMUs. + +#### 6.4.2.3 Indivisibility + +Indivisibility provides the means to specify whether or not a basic or composite logical object derived from a constituent constraint is allowed to be split over more than one page or over more than one area within a page. It may be specified for constituent constraints of the types Passage, NumberedSegment, Paragraph, Footnote, Number, FootnoteReference and BodyText. The attribute “indivisibility” is used to specify this feature. + +![Diagram illustrating the specification of margins for a layout object. A large rectangle represents the 'Lowest level frame'. Inside it is a smaller dashed rectangle representing the 'Area available for laying the content'. A path of arrows within the dashed rectangle indicates the 'Layout path'. Margins are defined as follows: 'Trailing edge margin' (top), 'Leading edge margin' (bottom), 'Right hand edge margin' (left), and 'Left hand edge margin' (right). The identifier 'T0804930-90/d10' is located at the bottom right of the diagram.](05eb72d372e4bf78e3d6a64949d77bcc_img.jpg) + +Diagram illustrating the specification of margins for a layout object. A large rectangle represents the 'Lowest level frame'. Inside it is a smaller dashed rectangle representing the 'Area available for laying the content'. A path of arrows within the dashed rectangle indicates the 'Layout path'. Margins are defined as follows: 'Trailing edge margin' (top), 'Leading edge margin' (bottom), 'Right hand edge margin' (left), and 'Left hand edge margin' (right). The identifier 'T0804930-90/d10' is located at the bottom right of the diagram. + +FIGURE 10/T.505 +Specification of margins + +#### 6.4.2.4 Same layout object + +Same layout object provides the means to specify that the start of the content associated with a logical object and the end of the content associated with the previous logical object are to be laid out within a single layout object. This may be specified for logical objects of the types NumberedSegment, Paragraph, Number, Footnote, FootnoteReference, BodyText, BodyRaster and BodyGeometric. The attribute “same layout object” is used to specify this feature. + +#### 6.4.2.5 Concatenation + +Concatenation provides the means to specify that the content associated with a basic logical object derived from a constituent constraint and the content associated with the basic logical object derived from a previous constituent constraint are to be regarded as an unbroken stream of content. This may be specified for constituent constraints of the types BodyText, Number, FootnoteReference, FootnoteText, CommonText and PageNumber. The attribute “concatenation” is used to specify this feature. + +#### 6.4.2.6 Block alignment + +Block alignment allows the content associated with a basic logical object to be specified as ‘left aligned’, ‘right aligned’ or ‘centred’ within the area in which that content is laid out. Left aligned means that the content is laid out adjacent to the left hand edge margin. Right aligned means that the content is laid out adjacent to the right hand edge margin and centred means that the content is laid out midway between the left and right margins. + +This feature may only be specified using the attribute “block alignment” for constituent constraints of the types Number, FootnoteReference, FootnoteText, PageNumber, FootnoteNumber, BodyText and CommonText, and when they contain formatted character content, BodyRaster, BodyGeometric, CommonRaster and CommonGeometric. + +### 6.4.3 Layout controls applicable in the absence of a generic layout structure + +In processable form documents the generic layout structure is optional. If the generic layout structure is omitted, then it is the responsibility of the receiver to define an appropriate layout structure. No limitations are placed on the layout structure that is used. + +When a generic layout structure is not specified within a processable form document, then restrictions are placed on the layout control functions described in 6.4.1 and 6.4.2 that may be specified within the document. These restrictions are indicated below. + +- It is not possible to specify that certain logical parts of a document are to be allocated to a given page set or that a part of a document is to be laid out starting in a new page set, as defined in 6.4.1.1. +- It is possible to specify page breaks as defined in 6.4.1.2 but it is only possible to indicate that the layout shall begin on a new page. It is not possible to specify a particular page class. +- The logical parts of the document that are intended to be laid out in the body area and in the header/footer areas of each page may be distinguished from each other by means of application comments specified for them (see 6.6.4). An exception is that it is not possible to distinguish whether a particular portion of the common content is to be placed in a header or footer area (or both). +- It is not possible to indicate the type of layout area to be used to layout each logical constituent in the body part of a document. That is, it is not possible to indicate whether single column or multiple column areas are to be used (see 6.4.1.3.1). This shall be decided by the receiver. +- Footnotes within the body part of a document may be distinguished by use of the attribute “application comments”. Footnotes are intended to be read and laid out separately from the other logical constituents of the body part (see 6.4.1.3.2). However, it is the responsibility of the receiver to decide how footnotes are laid out. +- Margins, separation, indivisibility, same layout object, concatenation, and block alignment, as defined in 6.4.2 may all be specified. Only one restriction applies. Indivisibility (see 6.4.2.3) may be assumed to specify that a logical object derived from the constituent constraint is not to split over more than one page but indivisibility shall not be specified for other types of layout areas such as single or multiple column areas. + +## 6.5 Content layout and imaging characteristics + +A document may contain character, raster graphics and geometric graphics content. + +The content architectures that may be specified using the attribute “content architecture class” are formatted character, processable character, formatted processable character, formatted processable raster graphics and formatted processable geometric graphics. Any of these may be specified as the default in the document profile. + +### 6.5.1 Character content + +#### 6.5.1.1 Introduction + +This subclause defines the features that are applicable to the character content contained in a document and the presentation attributes and control functions that may be used to specify these features. These features may apply to basic logical and layout components unless otherwise indicated. + +The default values for the following features may be specified in the document profile: + +- graphic character sets; +- graphic character subrepertoire; +- code extension announcers; +- line spacing; + +- character spacing; +- character path; +- line progression; +- character orientation; +- graphic rendition, including the parameters values: default rendition, increased intensity (bold), italicized, underlined, crossed-out, primary font, 1st alternative font, 2nd alternative font, 3rd alternative font, 4th alternative font, 5th alternative font, 6th alternative font, 7th alternative font, 8th alternative font, 9th alternative font, doubly underlined, normal intensity, not italicized, not underlined, not crossed out; +- line layout table; +- indentation; +- alignment; +- first line offset; +- itemization; +- widow size; +- orphan size; +- character fonts; +- kerning offset; +- proportional line spacing; +- initial offset. + +The specification in a document of a non-basic feature by a presentation attribute or control function shall be indicated in the document profile. + +#### **6.5.1.2 Character content architecture class** + +Processable and formatted processable form documents may contain processable, formatted or formatted processable character content. Formatted form documents may contain formatted and formatted processable character content. + +When using character content, any number of content portions may be associated with a basic component. + +The content information in a content portion may be absent. This is to allow the representation and interchange of documents in which parts of the content may be supplied, for example, during subsequent editing. + +#### **6.5.1.3 Character repertoires** + +The basic character repertoire supported by this Profile is composed of the 94 characters of ISO-IR 6 (the IRV of ISO/IEC 646) plus the character space. + +Any other graphic character set which is registered in accordance with ISO 2375 may be designated and invoked at any point in the document provided its use is indicated in the document profile as a non-basic value using the character presentation feature attribute “graphic character sets”. No locking shift functions are specified in this presentation feature. + +The code extension techniques allowed for the designation and invocation of character sets to the left hand side and right hand side of the 8-bit code table (GL and GR respectively) are defined in 6.5.1.4. + +Using these code extension techniques, the graphic character sets designated and/or invoked at the beginning of a content portion containing character content are specified by the presentation attribute “graphic character sets”. The graphic character sets may also be changed at any point within a content portion. + +The default graphic character sets which apply to the content portions within a document may be specified in the document profile using the presentation attribute “graphic character sets”. + +If the character set defined in ISO 6937 is designated and invoked, then the use of any of its sub-repertoires registered according to ISO/IEC 7350 may be specified using the presentation attribute “graphic character sub-repertoire”. All sub-repertoires are non-basic and their use shall be indicated in the document profile. The sub-repertoire shall not be changed within a content portion. + +NOTE – The basic character repertoire supported by this Profile is not the standard default value specified in CCITT Rec. T.416| ISO/IEC 8613-6; hence it may be necessary to specify, in the document profile of a particular document, that this is the default value being used for that document. + +#### 6.5.1.4 Code extension techniques + +The code extension techniques specified in ISO 2022 may be used subject to the following restrictions: + +- a) G0 set: only ISO-IR 6 (the IRV of ISO/IEC 646), ISO-IR 2 (the primary set of ISO 6937-2), or any other version of ISO/IEC 646 may be designated for this set; these graphic character sets may only be invoked in GL. +- b) G1, G2, G3 sets: no restrictions are placed on the character sets that may be designated for these sets; these graphic character sets may only be invoked in GR. +- c) The locking and single shift functions allowed are as follows: + - LS0 to invoke the G0 set into GL; + - LS1R to invoke the G1 set into GR; + - LS2R to invoke the G2 set into GR; + - LS3R to invoke the G3 set into GR; + - SS2 to invoke one character from the G2 set into GL; + - SS3 to invoke one character from the G3 set into GL.(Here GL and GR refer to the left and right hand parts respectively of the 8-bit code table) +- d) When specifying the presentation attribute “graphic character sets”, it is necessary to invoke character sets for both GL and GR. Thus an allowed character set shall be designated into G0 (see item a) above) and invoked into GL. It is also necessary to invoke a character set into GR which has been designated into the G1, G2 or G3 set. +- e) The empty set shall be designated into G1 and invoked into GR if no other specific character set is invoked into GR. + +The code extension techniques allowed are illustrated in Figures 11 and 12. + +The announcement and encoding of these functions are to be as specified in ISO 2022. + +The code extension techniques that are used or may be used in a basic component shall be specified by the presentation attribute “code extension announcers”. The default code extension announcers used throughout a document may be specified in the document profile, using the presentation attribute “code extension announcers”. + +NOTE – In accordance with CCITT Rec. T.416 ISO/IEC 8613-6, there is no restriction concerning the number of graphic character sets which may be designated and/or invoked in the presentation attribute “graphic character sets” providing the restrictions defined in this subclause are applied. Hence designation to a particular G set overrides a previous designation to that set and invocation to GL or GR overrides the previous invocation to the GL or GR respectively. Thus the sequential order of designation and/or invocation sequences in the attribute “graphic character sets” is significant. + +#### 6.5.1.5 Line spacing + +Any value of line spacing may be specified. The values of 150, 200, 300 and 400 BMUs are basic; the use of any other value in a document is non-basic and shall be indicated in the document profile. + +The line spacing may be specified at the beginning of the content associated with a basic component using the presentation attribute “line spacing”. The value may be changed anywhere within the content portion using the control functions SVS and SLS. + +![Diagram illustrating code extension features (basic case) for an 8-bit code table. The top part shows an 8-bit code table with two main sections: GL (left) and GR (right). Below the table, four boxes represent different code sets: G0, G1, G2, and G3. Arrows indicate mappings: LS0 points to G0, LS1R points to G1, and G2 and G3 are also shown. The bottom part shows the IRV of ISO/IEC 646 (ISO-IR 6) and an empty set. The designation T0810700-92/d11 is shown at the bottom right.](e64c7b989e5bdb2708cd7aefd18b06e1_img.jpg) + +[8-bit code table] + +| | | +|----|----| +| GL | GR | +|----|----| + +LS0                      LS1R                      [Invocation] + +G0 + +↑ + +The IRV of +ISO/IEC 646 +(ISO-IR 6) + +G1 + +↑ + +Empty set + +G2 + +G3 + +T0810700-92/d11 + +[Designation] + +Diagram illustrating code extension features (basic case) for an 8-bit code table. The top part shows an 8-bit code table with two main sections: GL (left) and GR (right). Below the table, four boxes represent different code sets: G0, G1, G2, and G3. Arrows indicate mappings: LS0 points to G0, LS1R points to G1, and G2 and G3 are also shown. The bottom part shows the IRV of ISO/IEC 646 (ISO-IR 6) and an empty set. The designation T0810700-92/d11 is shown at the bottom right. + +FIGURE 11/T.505 +Code extension features (basic case) + +#### 6.5.1.6 Character spacing + +Any value of character spacing may be specified. The values greater than or equal to 100 are basic; the use of any other value in a document is non-basic and shall be indicated in the document profile. + +The character spacing may be specified at the beginning of the content associated with a basic component using the attribute “character spacing”. The value may be changed anywhere within a content portion using the control functions SHS or SCS. + +##### NOTES + +- 1 A character spacing value of 160 BMUs is provided for use with Korean Hangul characters. +- 2 SHS parameters of 0, 1, 2, 3 and 4 are provided. The use of parameters 5 and 6 may be provided in a future edition of this Recommendation for use with Chinese characters. + +![Diagram illustrating code extension features for a 2-bit code table. The diagram shows a hierarchy of boxes representing different code sets. At the top is a box labeled '[8-bit code table]' containing 'GL' and 'GR'. Below it are four boxes labeled 'G0', 'G1', 'G2', and 'G3'. Arrows indicate mappings: 'LS0' points from 'G0' to 'GL'; 'LS1R' points from 'G1' to 'GL'; 'LS2R' points from 'G2' to 'GR'; 'LS3R' points from 'G3' to 'GR'. 'SS2' and 'SS3' are also shown within the 'GL' and 'GR' boxes. A note at the bottom left refers to 'The IRV of ISO/IEC 646 (ISO-IR 6) or the primary set of ISO 6937, or a version of ISO/IEC 646'. A note at the bottom right refers to 'Any registered graphic character set' and 'T0810710-92/d12 [Designation]'.](77959075c823bb5169480d7b8ff82a63_img.jpg) + +The diagram illustrates the mapping of code extension features. At the top is a box labeled "[8-bit code table]" containing "GL" and "GR". Below it are four boxes labeled "G0", "G1", "G2", and "G3". Arrows indicate mappings: "LS0" points from "G0" to "GL"; "LS1R" points from "G1" to "GL"; "LS2R" points from "G2" to "GR"; "LS3R" points from "G3" to "GR". "SS2" and "SS3" are also shown within the "GL" and "GR" boxes. A note at the bottom left refers to "The IRV of ISO/IEC 646 (ISO-IR 6) or the primary set of ISO 6937, or a version of ISO/IEC 646". A note at the bottom right refers to "Any registered graphic character set" and "T0810710-92/d12 [Designation]". + +Diagram illustrating code extension features for a 2-bit code table. The diagram shows a hierarchy of boxes representing different code sets. At the top is a box labeled '[8-bit code table]' containing 'GL' and 'GR'. Below it are four boxes labeled 'G0', 'G1', 'G2', and 'G3'. Arrows indicate mappings: 'LS0' points from 'G0' to 'GL'; 'LS1R' points from 'G1' to 'GL'; 'LS2R' points from 'G2' to 'GR'; 'LS3R' points from 'G3' to 'GR'. 'SS2' and 'SS3' are also shown within the 'GL' and 'GR' boxes. A note at the bottom left refers to 'The IRV of ISO/IEC 646 (ISO-IR 6) or the primary set of ISO 6937, or a version of ISO/IEC 646'. A note at the bottom right refers to 'Any registered graphic character set' and 'T0810710-92/d12 [Designation]'. + +FIGURE 12/T.505 +Code extension features (all possible cases) + +#### 6.5.1.7 Character path and line progression + +Both horizontal and vertical writing directions may be used within a document. In the case of horizontal writing, the characters progress either from left to right or from right to left across the page and the line progression is from the top of the page to the bottom. In the case of vertical writing, the characters progress from the top of the page to the bottom and the line progression is from the right to the left. The use of these writing directions is restricted by the page layout type used. + +For page layout A, only horizontal writing may be used in the body, header and footer areas. Thus, in this case the character path and line progression is specified either as 0° and 270° respectively or 180° and 90° respectively. + +For page layout B, again only horizontal writing may be used in the body, header and footer areas. However, in this case the content in the body area is presented for viewing with the page in landscape orientation and the content in the header and footer areas is presented for viewing when the page is in the portrait orientation. + +Thus for page layout B, in the body area the character path and line progression is specified either as 90° and 270° respectively or 270° and 90° respectively. In the header and footer areas, the character path and line progression is specified as in page layout A. + +For page layout C, only vertical writing may be used in the body area and only horizontal writing may be used in the header and footer areas. Thus in the body area the character path and line progression are specified as 270° and 270° respectively. In the header and footer areas, the character path and line progression is specified as in page layout A. + +For page layout D, only vertical writing may be used in the body, header and footer areas. Thus in all these areas, the character path and line progression are specified as 270° and 270° respectively. + +A character path value of 0° and a line progression value of 270° are basic values. All other values are non-basic and their use in a document shall be indicated in the document profile. + +The values of character path and line progression may be specified at the beginning of the content associated with a basic component using the presentation attributes “character path” and “line progression” respectively. These values cannot be changed within a content portion. + +#### **6.5.1.8 Character positioning controls** + +The active position of a character (as defined in CCITT Rec. T.416 | ISO/IEC 8613-6) can be moved forward or backward along the direction of the line progression using the control functions Line Position Backward (VPB) and Line Position Relative (VPR). These control functions may be specified in all forms of character content, and any parameter value may be specified. + +#### **6.5.1.9 Character orientation** + +The character orientation may be specified as 0° or 90° depending on whether vertical or horizontal writing is used (see 6.5.1.7). + +When horizontal writing is used, characters may only be orientated at 0°. When vertical writing is used, characters may be orientated at 90°. + +A value of 0° is basic; a value of 90° is non-basic and its use in a document shall be indicated in the document profile. + +The value of the character orientation is specified at the beginning of the content associated with a basic component by the presentation attribute “character orientation”. This value cannot be changed within the content. + +#### **6.5.1.10 Emphasis** + +The following modes of emphasizing graphic characters may be distinguished: + +- default rendition; +- normal intensity; +- increased intensity (bold); +- italicized; +- not italicized; +- underlined; +- doubly underlined; +- not underlined; +- crossed-out; +- not crossed-out. + +All the above mentioned modes of emphasis are basic. If no default mode is explicitly specified in the document profile, then the default mode is ‘default rendition’. + +The mode of emphasis may be specified at the beginning of the content associated with a basic component using the presentation attribute “graphic rendition”. The mode may be changed anywhere within the content using the control function SGR. + +The mode of emphasis remains in effect within the content associated with a basic component until changed into a mutually exclusive mode or by the specification of ‘default rendition’. Mutually exclusive modes are normal/increased intensity, italicized/not italicized, underlined/doubly underlined/not underlined and crossed out/not crossed-out. One mode from each mutually exclusive set may be in operation at any point in the document content. + +‘Default rendition’ cancels the effect of all modes of emphasis that are currently in operation and specifies that the text shall be displayed in accordance with the default rendition parameters set for the presentation device. Thus, for example, if it is required to ensure that the content is not underlined, then it is necessary to explicitly specify that underlined is not to be used. + +#### **6.5.1.11 Tabulation** + +Tabulation stop positions may be specified at any position along the character path. Each stop is specified by means of the following: + +- a) the tabulation position relative to the margin position in the direction opposite to the character path; +- b) an optional alignment qualifier that specifies the type of alignment to be used at the designated tabulation position. The type may be specified as one of the following: + - start aligned; + +- end aligned; +- centred; +- aligned around. + +These alignment qualifiers are defined in CCITT Rec. T.416| ISO/IEC 8613-6. If the alignment qualifier is not explicitly specified, then it is assumed that start aligned is to be used. + +Only one set of tabulation stops can be specified to be applicable to the content associated with a basic component. No limit is placed on the number of tabulation stops that may be specified within a given set. + +The set of tabulation stop positions associated with the content of a basic component are specified using the presentation attribute “line layout table”. Tabulation stop positions are invoked within the content using the control function STAB. + +The tabulation reference numbers used in the control function STAB and associated presentation attribute “line layout table” shall be chosen so that, in any given line layout table the reference numbers are unique, sequential in the direction of the character path and do not include leading zeroes. + +#### **6.5.1.12 Indentation** + +Indentation is the distance between the first character on a line of content and the position of the margin that is in the direction opposite to the direction of the character path. Thus the value of the indentation specified determines the line home position (as defined in CCITT Rec. T.416| ISO/IEC 8613-6). + +Indentation acts as temporary alteration in the position of the offset in the direction opposite to the direction of the character path. When text is formatted, it is intended to be laid out between the indentation position and the margin position in the direction of the character path. + +Any value of indentation may be specified for basic logical components using the presentation attribute “indentation”. The indentation value shall not be changed within a content portion. + +#### **6.5.1.13 Alignment** + +This feature is concerned with how the first and last characters on each line of character content are to be laid out during the formatting process. + +The following values of alignment may be specified as basic: + +- start aligned; +- end aligned; +- centred; +- justified. + +The semantics of these values are as defined in CCITT Rec. T.416| ISO/IEC 8613-6. + +The presentation attribute “alignment” is used to specify the alignment that is applicable to the content associated with a basic component. The alignment value cannot be changed within a content portion. + +#### **6.5.1.14 First line format** + +This feature specifies how the first line of the content associated with a basic component is to be laid out and provides for the itemisation of paragraphs. + +It allows the first character in the content to be positioned at some point along the character path relative to the indentation position (as specified in 6.5.1.12). This point may be in the direction of the character path or in the direction opposite to the direction of the character path relative to the indentation position. + +In addition, this feature provides for the specification of an item identifier on the first line. The item identifier is a string of characters that precedes and is separated from the remaining characters that form the first line. The control function Carriage Return (CR) is used as the separator. + +The features provided correspond to examples 10.1 to 10.5 shown in Figure 10 of CCITT Rec. T.416| ISO/IEC 8613-6. + +First line format is specified by the presentation attributes “first line offset”, “itemisation”, and “indentation”. Only those values of the attributes which combine to form the examples shown in Figure 10 of CCITT Rec. T.416| ISO/IEC 8613-6 may be used. + +#### 6.5.1.15 Widow and orphan sizes + +The widow size specifies the minimum number of lines of content that shall be allocated to a following frame or page when the content associated with a basic logical component is laid out such that it flows over two frames or pages. To accommodate this, it may be necessary to move a number of lines of content from one frame or page to the next frame or page. + +The orphan size specifies the minimum number of lines of content that shall be placed in the current frame or page when the content associated with a basic logical component is split over two frames or pages. If this minimum cannot be accommodated, then the whole content shall be placed in the next frame or page. + +Any value of widow or orphan size may be specified using the presentation attributes “widow size” and “orphan size” respectively. + +Widow and orphan size may only be specified for character content placed in body area of pages. + +#### 6.5.1.16 Fonts + +Any number of fonts may be used within a document. The fonts used in a particular document are specified in the document profile using the attribute “fonts list”. + +Further information concerning the specification of font references in the document profile is given in B.2. + +The fonts that may be used within the content associated with each basic component are specified by the presentation attribute “character fonts”. Up to 10 fonts taken from the list specified by the attribute “fonts list” may be specified by the attribute “character fonts”. + +The font to be used at the start of the content associated with a basic component is specified using the attribute “graphic rendition”. The fonts used within the content may be changed using the control function SGR. + +The document profile may specify, using the attribute “character fonts”, a default set of up to 10 fonts that are applicable to the whole document. + +#### 6.5.1.17 Reverse character strings + +Bi-directional writing is supported by this Profile. Hence, a string of characters in a content portion associated with a basic component may be specified to be imaged in the reverse direction of the immediately preceding character string. Such strings may be specified by the control function SRS as defined in CCITT Rec. T.416 | ISO/IEC 8613-6. + +This control function is provided for cases in which the text belongs to different languages and the character content is written, for example, from left to right or from right to left within the same line of characters, dependent upon the language and/or character set being used. + +NOTE – The use of this control function cannot be indicated in the document profile. Thus it is intended that implementations shall ignore this control function when reverse character string layout and presentation is not supported. + +#### 6.5.1.18 Kerning offset + +A kerning offset value for the content associated with a basic component may be specified using the presentation attribute “kerning offset”. It is necessary to specify such a value when certain fonts are invoked to ensure that no part of character images are positioned outside the boundary of the available area. + +#### 6.5.1.19 Proportional line spacing + +The use of proportional line spacing may be invoked for the content associated with a basic logical component using the attribute “proportional line spacing”. When this invocation occurs, the line spacing between each pair of consecutive lines is determined in an implementation-defined way from the attributes associated with the fonts used within the two lines and may vary from one line to the next. This process is application dependent. + +#### 6.5.1.20 Superscripts and subscripts + +Superscripts and subscripts may be specified anywhere within the content associated with a basic component by using the control functions PLU and PLD. The use of these control functions shall be in accordance with CCITT Rec. T.416 | ISO/IEC 8613-6. + +#### 6.5.1.21 Line breaks + +The control functions BPH and NBH may be inserted in processable and formatted precessable form character content to indicate where line breaks may occur or may not occur respectively, when the content is laid out. + +#### 6.5.1.22 Substitution of characters + +The control function SUB is provided to represent characters produced by a local system that cannot be represented by a character within a character set supported by this [Profile](#). + +#### 6.5.1.23 Initial point + +The initial point which is applicable to basic layout components may be specified by the attribute “initial offset”. Any value may be specified. + +#### 6.5.1.24 Use of control functions + +The following is a list of all the control functions and parameter values (where applicable) that may be specified in character content: + +| | | +|------------------------------------------------|-------------------------------------------------------------------------------------| +| SHS | Select Character Spacing (allowed parameter values: 0, 1, 2, 3, 4) | +| SCS | Set Character Spacing (allowed parameter values: any) | +| SVS | Select Vertical Spacing (allowed parameter values: any) | +| SLS | Set Line Spacing (allowed parameter values: any) | +| SGR | Select Graphic Rendition (allowed parameter values: 0, 1, 2, 3, 4, 9-19, 21-24, 29) | +| STAB | Selective Tabulation (allowed parameter values: any) | +| SRS | Start Reverse String (allowed parameters: any) | +| VPB | Line Position Backward (allowed parameter values: any) | +| VPR | Line Position Relative (allowed parameter values: any) | +| PLD | Partial Line Down | +| PLU | Partial Line Up | +| BPH | Break Permitted Here | +| NBH | No Break Here | +| JFY | No Justify | +| SUB | Substitute | +| SP | Space | +| CR | Carriage Return | +| LF | Line Feed | +| SOS | Start Of String | +| ST | String Terminator | +| Code extension control functions (see 6.5.1.4) | | + +The use of all these control functions, with the exception of SP, CR, LF, SOS and ST are described in various subclauses in 6.5.1. + +#### 6.5.1.25 Formatting the content + +The attribute “formatting indicator” shall not be specified within documents that are conformant with this [Profile](#). + +### 6.5.2 Raster graphics content + +#### 6.5.2.1 Introduction + +This subclause defines the features that are applicable to the raster graphics content contained in a document. These features may apply to basic logical and layout components unless otherwise indicated. + +The default values for the following features may be specified in the document profile: + +- type of coding; +- compression; +- pel spacing; +- spacing ratio; +- image dimensions. + +The specification in a document of a non-basic feature by a presentation or coding attribute or control function shall be indicated in the document profile. + +#### 6.5.2.2 Raster graphics content architecture + +Only the formatted processable raster graphics content architecture class may be used in documents that conform to this document application profile. This type of content may be used in processable, formatted and formatted processable form documents. + +When using raster graphics content, only one content portion may be associated with an object or object class. + +The content information in a content portion may be absent. This is to allow the representation and interchange of documents in which parts of the content may be supplied, for example, during subsequent editing. + +Also, the scalable or fixed dimension content layout process may be used when laying out and imaging the content depending upon the specification of the presentation attributes “pel spacing” and “imaging dimensions” as described in 6.5.2.6 and 6.5.2.8. Both forms of content layout processes may be used in a single document. + +#### 6.5.2.3 Raster graphics encoding methods + +The content may be encoded in accordance with the encoding schemes defined in CCITT Recommendations T.4 and T.6. In the case of Recommendation T.4, either the one-dimensional or two dimensional encoding scheme may be used. Also the ‘bit-map encoding’ scheme defined in CCITT Rec. T.417 ISO/IEC 8613-7 may be used. All these forms of encoding may be used in a single document and all are basic. ‘Uncompressed’ mode of encoding may also be used but as a non-basic feature. + +When using the T.4 or T.6 encoding method, the relationship between the order of pels and the order of bits in the octets in the coded data stream shall be such that the first pel in the order of bits is allocated to the least significant bit of an octet. In the case of bit-map encoding, the order of encoding shall be that the first pel is allocated to the most significant bit of an octet. + +In a content portion, if content information is specified then it is required that the coding attribute “number of pels per line” is specified; the coding attribute “number of lines” may also be specified. No restriction is placed on the values that may be specified for these coding attributes. Thus this Profile places no restriction of the size of the pel arrays that may be used. + +The type of encoding method used is specified by the attribute “type of coding”. The use of this attribute is non-mandatory. Thus, if this attribute is not specified for a particular content portion and if the content architecture class specified corresponds to the formatted processable raster graphics content architecture class, then the default encoding method is assumed to be that defined in CCITT Recommendation T.6. + +#### 6.5.2.4 Pel path and line progression + +The pel path and line progression provided are 0° and 270° respectively. This Profile does not allow the specification of other values. + +#### 6.5.2.5 Clipping + +A sub-region within a pel array represented by a content portion associated with a basic component may be defined using the presentation attribute “clipping”. No restriction is placed on the use of this attribute. + +#### 6.5.2.6 Pel spacing + +The pel spacing is the distance in BMUs between any two pels on a line when a pel array is imaged. Any value may be explicitly specified provided that the spacing between pels is not less than 1 BMU. The pel spacing need not be an integer value. Also, the value ‘null’ may be specified, indicating that the scalable layout process is to be used. + +The specification of the value ‘null’ or spacings of 16, 12, 8, 6, 5, 4, 3, 2, and 1 BMU between adjacent pels are basic. The specification of any other spacing is non-basic and shall be indicated in the document profile. + +The pel spacing applicable to content associated with basic logical components is specified by the presentation attribute “pel spacing”. + +##### NOTES + +1 The basic pel spacing values listed above are equivalent to resolutions of 75, 100, 150, 200, 240, 300, 400, 600 and 1200 pels per 25.4mm respectively when the document is imaged in its specified size. + +2 The attribute “pel spacing” specifies two integers, the ratio of which determines the pels spacing. No restriction is placed on the values of these integers. + +#### 6.5.2.7 Spacing ratio + +The spacing ratio is the ratio between the pel spacing and the line spacing when a pel array is imaged. This ratio is used to determine the line spacing from the pel spacing specified. + +No restrictions are placed on the value of this ratio providing that the resultant line spacing is not less than 1 BMU. Also, the line spacing need not be an integral number of BMUs. All values are basic. + +The default value may be specified in the document profile. If no default value is explicitly specified then the default value is the ratio 1:1, that is, the line spacing is equal to the pel spacing. + +The spacing ratio applicable to the content associated with a basic logical component is specified by the presentation attribute “spacing ratio”. + +#### 6.5.2.8 Image dimensions + +The image dimensions are the constraints to be applied to the size of the image produced when laying out a pel array represented by a content portion associated with a basic logical component. + +These constraints are specified for basic logical components by the presentation attribute “image dimensions”. The value of this attribute is only taken into account if the value of the attribute “pel spacing” is ‘null’. + +### 6.5.3 Geometric graphics content + +A document may contain graphic images composed of geometric graphic content encoded as CGM metafiles in accordance with ISO/IEC 8632. Each CGM Figure shall consist of a single picture only. Each GCM Figure may specify its minimum dimensions. + +Further information concerning the specification of geometric graphics content information is given in Annex B. + +## 6.6 Miscellaneous features + +### 6.6.1 Resource-documents + +Object classes of the types BodyText, BodyRaster and BodyGeometric, CommonText, CommonRaster, CommonGeometric and GenericBlock may refer to corresponding constituents in a resource-document. + +The constituents in the resource-document may refer to content portions and to layout and presentation styles that are contained within the resource-document. + +The constituents listed above are the only ones that are allowed to be referenced from another document via the attribute “resource”; however, a generic-document used as a resource-document may contain any combination of generic constituents which is conformant to this document application profile. + +### 6.6.2 External documents + +In the case of processable and formatted processable, the generic logical structure, and the generic layout structure if present, may be contained in an external document. Note that it is not permitted to exchange one generic structure in the interchanged document whilst referencing the other through the external document. + +### 6.6.3 Border + +Border may be specified for all the frames defined in 6.3.5 and 6.3.6 using the attribute “border”. Borders may also be specified in presentation styles. All the features of border specified in CCITT Rec. T.412 | ISO/IEC 8613-2, may be specified. The use of border is a non-basic feature and shall be indicated in the document profile. Border shall not be specified for the constituents GenericBlock and SpecificBlock. + +### 6.6.4 Application comments + +Specification of the attribute “application comments” is mandatory for all object classes contained in a document that conforms to this Profile. Specification of this attribute is mandatory for all objects that do not refer to an object class. Specification of this attribute is optional for all objects that refer to object classes. + +This attribute is structured so that it contains two fields. The first field is mandatory when the attribute is specified and contains a numeric string which uniquely identifies the constituent constraint applicable to the constituent for which the attribute is specified. This facilitates the processing of documents. A list of these identifiers is given in Table 2. + +NOTES + +1 The values of the constituent constraint numeric identifiers are not unique between the logical and layout structures and therefore in order to identify the constituent constraint applicable to a constituent it is necessary to know the structure of which the constituent is a part. + +2 For constituent constraints that correspond to each other between the hierarchically related Profiles to which this Profile belongs, the same constituent constraint numeric identifier is specified. + +The second field is optional and may contain any information that is relevant to the application or user. The format of the second field is not defined in this Profile and the interpretation of this field depends upon a private agreement between the originator and recipient of the document. + +The encoding of the attribute “application comments” is defined in 8.1.3. and 8.2.3. + +### **6.6.5 Alternative representation** + +The content information in a content portion may be replaced by a string of characters specified in the attribute “alternative representation”. This attribute may be specified in content portions that contain character, raster graphics or geometric graphics content. + +The specification and use of this attribute is optional. The string of characters specified shall belong to the character repertoires indicated in the document profile attribute “alternative representation character sets” (see 6.7.4.3). If the latter attribute is not explicitly specified in the document profile, then the default defined in CCITT Rec. T.411 | ISO/IEC 8613-1 is assumed. The control functions SP, CR and LF may also be used within the character string but no other control function is allowed; hence graphic character sets cannot be changed within the alternative representation. + +TABLE 2/T.505 + +#### **List of number string identifiers** + +| Logical constituent constraints | Constituent constraint numeric identifiers | +|---------------------------------|--------------------------------------------| +| DocumentLogicalRoot | 0 | +| Passage | 1 | +| NumberedSegment | 2 | +| Number | 3 | +| Paragraph | 6 | +| Footnote | 8 | +| FootnoteNumber | 9 | +| FootnoteReference | 10 | +| FootnoteBody | 11 | +| FootnoteText | 12 | +| BodyText | 14 | +| BodyRaster | 17 | +| BodyGeometric | 18 | +| CommonContent | 19 | +| CommonText | 20 | +| CommonRaster | 21 | +| CommonGeometric | 22 | +| PageNumber | 40 | +| Layout constituent constraints | Constituent constraint numeric identifiers | +| DocumentLayoutRoot | 0 | +| PageSet | 1 | +| Page | 2 | +| RectoPage | 3 | +| VersoPage | 4 | +| CompositeHeader | 5 | +| VariableCompositeBody | 7 | +| ColumnFixed | 8 | +| ColumnVariable | 9 | +| SnakingColumns | 10 | +| SynchronizedColumns | 11 | +| BasicFloat | 12 | +| FootnoteArea | 15 | +| ArrangedContentFixed | 16 | +| ArrangedContentVariable | 17 | +| SourcedContentFixed | 18 | +| SourcedContentVariable | 19 | +| BasicHeader | 27 | +| BasicBody | 28 | +| GenericBlock | 29 | +| SpecificBlock | 30 | +| CompositeFooter | 32 | +| BasicFooter | 33 | + +### **6.6.6 Automatic numbering mechanisms** + +#### **6.6.6.1 Page Numbering** + +As described in 6.2.4.3, the constituent constraint PageNumber contains a content generator which may refer to a page number. This content generator is evaluated when the document is laid out and this mechanism provides a means of reproducing the appropriate number of each page of a document. + +The content generator has the following format: + +<string-literal><num-expr><string-literal> + +The format of this content generator is defined in the macro PGNUMBER (see Note). + +The <string-literal> fields are optional and are pre-defined character strings. The basic character repertoire used to specify these strings is the ISO-IR 6 (the IRV of ISO/IEC 646). Any other character repertoire, and sub-repertoire if appropriate, may be used provided that it is designated and invoked by the appropriate code designation and invocation + +sequences, and indicated in the document profile as a non-basic value. SP and no other control functions may be used in these strings. + +The field <num-expr> is a reference to a binding PGnum which specifies the number of the page concerned. This binding is initialised at the document layout root or page set level (see the macro INITIALISEPGNUM in 7.4.1) and automatically incremented on each successive page (see macro PAGENUMBER in 7.4.1). By placing initialisation on the layout root, rather than on the pageset class(es), the pagenumbers may be defined to be continued from one pageset to the next. + +The content associated with logical object classes of the type PageNumber is laid out in a frame of one of the following types: BasicHeader, BasicFooter, SourcedContentVariable, SourcedContentFixed (see 6.3.6) using the logical source mechanism. Thus when the appropriate frame is being laid out, the field <num-expr> in the content generator contained in a logical object class of the type PageNumber is evaluated and this determines the value of the binding PGnum that is associated with the current page being laid out. + +The number associated with the binding PGnum is applied to a string function during its evaluation in order to convert the number into a character string. This enables the number to be represented in the form of an Arabic numeric string, an upper or lower case Roman numeric string or an upper or lower case alphabetic string. + +Each page class may refer to a different instance of logical object classes of the type PageNumber and this allows different page numbering formats to be used for different parts of the document. + +An example of page numbering is 'Page X' which consists of two concatenated character strings. The first is the literal character string 'Page' and this is concatenated to a string function denoted by 'X'. When 'X' is evaluated in a particular instance it may, for example, return the character string 'iv', the Roman numeral (lower case) for the number '4'. + +#### 6.6.6.2 Segment numbering + +As described in 6.2.3.4, the constituent constraint Number contains a content generator which, when evaluated during the layout process, produces a character string that serves to identify the NumberedSegment to which the Number belongs. + +The format of this character string is as follows: + +<pre-str><num-str><suf-str> + +This format is defined in the macro SEGMENTNUMBER (see Note). + +The fields <pre-str> and <suf-str> are optional prefix and suffix character strings respectively which may be of any length. The basic character repertoire used to specify these strings is the primary character repertoire of ISO 8859-1. Any other character repertoire, and sub-repertoire if appropriate, may be used provided that it is designated and invoked by the appropriate designation and innovation sequences and indicated in the document profile as a non-basic value. No other control functions may be used in these strings. + +The field <num-str> is the segment identifier which consists of a single number or a sequence of two or more numbers, each of which is separated by a separator. The separator is a character string and may, for example, consist of a full stop or space. An example of a segment identifier is "6.3.4.2.1". Thus segment identifiers have the general form: + +<number>[<separator><number>]... + +where [...] indicates optional repetition. + +In a document, the prefix and suffix character strings are string literals or carried by the bindings 'prefix -<n>' and 'suffix -<n>' respectively. The separator character strings are carried by bindings of the form 'separator-<n>' and the segment identifier <num-str> is carried by the binding 'numberstring-<n>'. + +In all these bindings '<n>' is a sequence of one or more digits which indicate the depth of numbering, such that n = 1 indicates the number (prefix, suffix, numberstring etc) for the numbered segments immediately subordinate to a Passage, n = 2 indicates the number (prefix, suffix, separator etc) for the numbered segments immediately subordinate to the first level of numbered segments, and so on. The level number shall be indicated using the smallest possible number of characters, that is, there shall be no leading zeroes. + +These bindings may be initialised at the document logical root, passage or at any numbered segment level to start the numbering scheme sequence at a subordinate level of numbered segment. They may also be re-specified at any level within the numbering scheme. The initialisation of bindings is specified by the macro INITIALISEANY. + +The placement of bindings initialisations for numbering schemes is significant. Initial values for numbers-n bindings shall be placed either at the Passage level, or on the NumberedSegment class which is superior to that in which the binding will be referenced. Similarly, prefix and suffixes and separators shall be initialised either at the Passage or at the + +immediately superior NumberedSegment level to their use. In particular note the prefix and suffix are not inherited by lower levels in hierarchy (since they belong to the content generator SEGMENTNUMBERS rather than the binding Numberstrings-n). Thus to have concatenation to say '(1).a', lower level shall have a prefix of '(' and separator of ')'.', + +In order to evaluate the value of 'numberstring-<n>' for each numbered segment, a number is assigned to each numbered segment at a given level. If the numbered segments are all of the same class then this number may be determined by the ORDINAL numeric function. If they are of different classes, then the number is carried by a binding of the form 'number-<n>'. + +A different binding of the type 'number-<n>' is used for each numbered segment level and is initialised at a higher level constituent than the one in which it is used. The number associated with each numbered segment level is automatically incremented for each successive numbered segment (see the macro USENUMBERS). + +The binding 'numberstring-<n>' that is applicable to a given level of numbered segment is now constructed as follows: + +<numberstring-x><separator-y><number-z> + +Hence, the segment identifier consists of a concatenation of up to three fields. The field <numberstring-x> is a reference to the segment identifier applicable to the immediately superior level of numbered segment (if any). This identifier is in the form of a character string. The field <separator-y> is a reference to a separator defined at some higher level in the document structure. + +The field <number-z> is the number applicable to the given numbered segment whose identifier is being constructed. As indicated above, this number may be determined from an ORDINAL expression or by reference to a binding of the form 'number-<n>' which is specified for the same numbered segment whose identifier is being constructed. In either case, a string function is applied to the number to convert it into a character string. This string function allows the number to be represented in one of the following forms: Arabic number string, upper or lower case Roman numeral string, or upper or lower case alphabetic characters. This construction is defined in the macro USENUMBERSTRINGS. + +The constructed binding of the form 'numberstring-<n>' is then available for constructing the identifiers at lower levels of numbered segments. This binding is also referred to in a content generator carried by the Number, which causes the identifier (with optional prefix and suffix strings) to be generated and reproduced when the document is laid out. + +NOTE – The macros referred to in this subclause are defined in 7.3.1. + +#### 6.6.6.3 Footnote numbering + +A footnote number is a character string that identifies a given footnote. The format of this string is as follows: + +<string-literal><num-str><string-literal> + +This format is defined in the macro FNOTENUMBER. + +The <string-literal> fields are optional and are pre-defined prefix or suffix character strings. The basic character repertoire used to specify these strings is the primary character repertoire of ISO 8859-1. Any other character repertoire, and sub-repertoire if appropriate, may be used provided that it is designated and invoked by the appropriate designation and innovation sequences, and indicated in the document profile as a non-basic value. No other control functions may be used in these strings. + +The field <num-str> is an automatically generated numeral or a user supplied character string that generally serves to identify a particular footnote. Numerals may be represented in the form of Arabic numerals, upper or lower case Roman numerals or upper or lower case Alphabetic characters. Automatically generated footnote numbers are incremented sequentially from an initial value which may be set to any positive value at the beginning of the document and reset at any passage. + +A single binding 'fnotenumber' is provided to represent footnote numbers. This may be initialised to any non-negative number at the logical root or on any Passage (see specification of the macro INITIALISEFNOTE). + +The footnote number is incremented using a binding expression at each footnote object (see the macro INCFNOTENUMBER). This is then made into a character string using a string function. This value is assigned to the binding 'fnotestring' (see the macro FNOTENUMBERSTRING). + +Alternatively, a character string literal may be assigned to the binding 'fnotestring'; this provides the user with the ability to supply particular footnote labels for individual footnotes (see the macro FNOTESTRINGLITERAL). + +The constituents FootnoteReference and FootnoteNumber contain content generators whose format is defined by the macro FNOTENUMBER. As indicated above, this format consists of a field represented by <num-str> which has optional prefix and suffix string literals. The field <num-str> consists of a reference to a binding 'fnotestring' which specifies the number of the footnote in the form of a character string. + +### 6.6.7 User readable comments + +Information which is to be interpreted as comments relevant to constituents and associated content portions may be specified using the attribute “user readable comments”. This information is intended for presentation to humans. + +The information consists of a string of characters which shall belong to one of the character repertoires indicated in the document profile attribute “comments character sets” (see 6.7.4.2). If the latter attribute is not explicitly specified, then the default defined in CCITT Rec. T.411 | ISO/IEC 8613-1 is assumed. The control functions CR, LF, SP and code extension control functions may also be used within the character string but no other control functions are allowed. + +### 6.6.8 User visible name + +Information which may be used to identify constituents within a document may be specified using the attribute “user visible name”. This information is intended for presentation to humans, for example, to assist in the editing of documents. + +The information consists of a string of characters which shall belong to one of the character repertoires indicated in the document profile attribute “comments character sets” (see 6.7.4.2). If the latter attribute is not explicitly specified, then the default defined in CCITT Rec. T.411 | ISO/IEC 8613-1 is assumed. The control functions CR, LF, SP and code extension control functions may also be used within the character string but no other control functions are allowed. + +## 6.7 Document management features + +Information relating to the document as a whole is specified in the document profile which is represented by the constituent constraint *DocumentProfile*. This constituent shall be specified in every document. + +The information in the document profile is classified into the following categories: + +- document constituent information; +- document identification information; +- document default information; +- non-basic characteristics information; +- document management information. + +The information in the document profile may be of interest to the user or may be used for machine processing of the document. + +### 6.7.1 Document constituent information + +This information specifies which constituents are used to represent the document, including constituents that are external to the interchanged document. This information is divided into three categories. + +#### 6.7.1.1 Presence of document constituents + +This information indicates which constituents are included in the document. That is, this information indicates whether or not the document contains a generic logical structure, a specific logical structure, a generic layout structure, a specific layout structure, layout styles and presentation styles (see Note). It is mandatory to specify this information in the document profile. + +NOTE – If the generic logical or layout structure is external to the document (see 6.7.1.3), then it is still necessary to indicate that these structures are present and form part of the document. + +#### 6.7.1.2 Resource-document information + +This information consists of a reference to a resource-document (see 6.6.1). This is specified by the attribute “resource-document”. If constituents in the document contain references to object classes in a resource-document, then it is mandatory to specify this information in the document profile. + +#### 6.7.1.3 External document information + +This information consists of a reference to an external document which may consist of a generic logical structure, or both generic layout and generic logical structures (see 6.6.2). If such a reference is required, then it is specified by the attribute “external document class” in the document profile. + +### 6.7.2 Document identification information + +This information relates to the identification of the document. This information is divided into six categories. + +#### **6.7.2.1 Document application profile information** + +This information indicates the document application profile to which the document belongs. It is mandatory to specify this information using the attribute “document application profile”. + +#### **6.7.2.2 Document architecture class information** + +This information indicates the document architecture class to which the document belongs (see 6.1). It is mandatory to specify this information using the attribute “document architecture class”. + +#### **6.7.2.3 Content architecture classes information** + +This information indicates the content architecture classes used in the document (see 6.5.1.2, 6.5.2.2 and 6.5.3). It is mandatory to specify this information using the attribute “content architecture classes”. + +#### **6.7.2.4 Interchange format class information** + +This information indicates the interchange format class used to represent the document (see clause 8). It is mandatory to specify this information using the attribute “interchange format class”. + +#### **6.7.2.5 ODA version information** + +This information indicates the International Standard or CCITT/ITU-T Recommendation to which the document conforms. It also specifies a calendar date, which indicates that the document conforms to the version of the International Standard or CCITT/ITU-T Recommendation and any addenda that are current on that date. It is mandatory to specify this information using the attribute “ODA version”. + +#### **6.7.2.6 Document reference** + +This information serves to identify the document. Typically this information is allocated to the document by the creator of the document. The identifier may consist of an ASN.1 object identifier or a string of characters. It is mandatory to specify this information using the attribute “document reference”. + +### **6.7.3 Document default information** + +This information specifies various default values for attributes used in the document. The default values that are allowed are specified in the various subclauses of clause 6. The specification of this information is only required when it is required to specify a default value which is other than the standard default value specified in CCITT Rec. T.411 | ISO/IEC 8613-1. + +Default values for the following groups of attributes may be specified: + +- document architecture attributes; +- character content attributes; +- raster graphics attributes; +- geometric graphics attributes. + +### **6.7.4 Non-basic characteristics information** + +This information specifies the non-basic attribute values specified in the document. It is mandatory to specify a non-basic attribute value in the document profile when such a value is used in the document. + +The following types of non-basic attribute values may be specified: + +- comments character sets; +- alternative representation character sets; +- page dimensions; +- medium-types; +- layout paths; +- borders; +- character presentation features; +- raster graphics presentation features; +- raster graphics coding attributes. + +Further information concerning document profile, comments and alternative representation character sets is given below. + +#### 6.7.4.1 Profile character sets + +Some document profile attributes have values consisting of character strings, for example, the document management attributes. The character sets used in these character strings are specified by the document profile attribute “profile character sets”. + +This attribute “profile character sets” specifies a code extension announcer and designations of character sets, which are subject to the following restrictions: + +- The code extension announcer shall be 04/03 when specified. This code extension announcer specifies the use of G0 and G1 sets in an 8-bit environment and also the invocation of G0 and G1 sets into GL and GR respectively. Thus, in each attribute to which this attribute applies, invocation shift functions are not necessary, because G0 and G1 sets are implicitly invoked by this code extension announcer. +- G0 set: only ISO-IR 6 (the IRV of ISO/IEC 646), ISO-IR 2 (the primary set of ISO 6937), or any other version of ISO/IEC 646 may be designated for this set; these graphic character sets are implicitly invoked in GL. +- G1: no restrictions are placed on the graphic character sets that may be designated for this set; these graphic character sets are implicitly invoked in GR. +- Profile character sets. +- The empty set shall be designated into G1 and invoked into GR if no other specific character set is invoked in GR. + +If the attribute “profile character sets” is not specified, then the default defined in CCITT Rec. T.411 | ISO/IEC 8613-1 is assumed. + +#### 6.7.4.2 Comments character sets + +The character sets assumed to have been designated and optionally invoked at the beginning of the character strings specified by the attributes “user readable comments” (see 6.6.7) and “user visible name” (see 6.6.8) are specified using the document profile attribute “comments character sets”. + +It also specifies the code extension techniques and the graphic character sets which may be used in the attributes “user readable comments” and “user visible name”. + +If this attribute is specified, the code extension techniques which may be used in the attributes “user readable comments” and “user visible name” shall be announced by appropriate code extension announcers. The use of G0 set and GL shall always be announced. Other code extension announcers are to be specified according to the requirements of a particular document. + +Two kinds of code extension techniques are permitted for this attribute. One is to use GL and GR without shift functions, and the other is to use various character sets by shift functions. The former is rather restricted but no shift functions are necessary in the “user readable comments” and “user visible name”. The same restriction as in 6.7.4.1 is applied in this case. + +The latter permits various usages of character sets but invocations shall be specified by shift functions in the “user readable comment” and “user visible name”. The same restriction as in 6.5.1.4 is applied in this case. + +All the graphic character sets which may be used in the attributes “user readable comments” and “user visible name” shall be designated in the “comments character sets”. + +There are no restrictions concerning the number of graphic character sets which are designated and/or invoked in the “comments character sets”; hence designation to the same G set overrides the previous G set. + +If the attribute “comments character sets” is not specified, then the default defined in CCITT Rec. T.411 | ISO/IEC 8613-1 is assumed. + +#### 6.7.4.3 Alternative representation character sets + +This attribute specifies the graphic character sets designated and invoked at the beginning of the attribute “alternative representation” other than the standard default graphic character sets. + +The restriction on profile character sets described in 6.7.4.1 is also applied. If this attribute is not explicitly specified in the document profile, the default defined in CCITT Rec. T.411 | ISO/IEC 8613-1 is assumed. + +### 6.7.5 Fonts list + +This information specifies all the fonts (if any) used in the document. It is specified using the attribute “fonts list” (see B.2). + +### 6.7.6 Document management attributes + +Document management attributes contain information about the content of the document and its purpose. Information relating to the following may be specified: + +- document description (see the Note below); +- dates and times; +- originators; +- other user information; +- external references; +- local file references; +- content attributes; +- security information. + +The attributes that may be used to specify this information are defined in CCITT Rec. T.414 | ISO/IEC 8613-4. + +The string of characters used in the document management attributes shall belong to the character sets indicated in the document profile attribute “profile character sets” (see 6.7.4.1). If the latter attribute is not explicitly specified in the document profile, then the default character set is the minimum sub-repertoire of ISO 6937. + +The control functions SP, CR and LF may also be used within the character strings but no other control functions are allowed. Hence the graphic character set cannot be changed in the document management attributes. + +NOTE – The document description includes the specification of the document reference (see 6.7.2.6). + +# 7 Specification of constituent constraints + +This clause specifies the definition of the constituent constraints which may be represented by data streams conforming to this Profile. + +## 7.1 Introduction + +The structure diagrams illustrating the relationships between the constituents in the logical structures are shown in 7.1.1 (see Figures 13 to 15). The macros indicated on these diagrams are defined in 7.3.1. These macros define the permissible values for the attribute “generator for subordinates” that are applicable to the constituents and define the allowed structures that are provided by this Profile. + +The structure diagrams illustrating the layout structures are shown in 7.1.2 (see Figures 16 to 18). The macros indicated in these diagrams are defined in 7.4.1. + +### 7.1.1 Diagrams of relationships of logical constituents + +![Figure 13/T.505: The body part of the generic logical structure – The passage and numbered segment levels. This hierarchical diagram shows the structure from DocumentLogicalRoot down to various body elements. DocumentLogicalRoot connects to Passage via DocLogRootGFS. Passage connects to a dashed box 'X' via PassageGFS. This 'X' connects to another dashed box 'X'. This second 'X' branches into five paths: Paragraph (via Constraint-1), BodyText, BodyGeometric, BodyRaster, and NumberedSegment (via Constraint-2). Paragraph connects to a dashed box 'Y'. NumberedSegment connects to Number and a dashed box 'X' via Numbered-SegmentGFS.](701bc79e78b382bcfd3ba85597dbb9c3_img.jpg) + +``` + +graph TD + DL[DocumentLogicalRoot] -- DocLogRootGFS --> P[Passage] + P -- PassageGFS --> X1[X] + X1 -.-> X2[X] + X2 -- Constraint-1 --> Para[Paragraph] + X2 --> BT[BodyText] + X2 --> BG[BodyGeometric] + X2 --> BR[BodyRaster] + X2 -- Constraint-2 --> NS[NumberedSegment] + Para --> Y[Y] + NS -- Numbered-SegmentGFS --> N[Number] + NS -- Numbered-SegmentGFS --> X3[X] + +``` + +T0810720-92/d13 + +Figure 13/T.505: The body part of the generic logical structure – The passage and numbered segment levels. This hierarchical diagram shows the structure from DocumentLogicalRoot down to various body elements. DocumentLogicalRoot connects to Passage via DocLogRootGFS. Passage connects to a dashed box 'X' via PassageGFS. This 'X' connects to another dashed box 'X'. This second 'X' branches into five paths: Paragraph (via Constraint-1), BodyText, BodyGeometric, BodyRaster, and NumberedSegment (via Constraint-2). Paragraph connects to a dashed box 'Y'. NumberedSegment connects to Number and a dashed box 'X' via Numbered-SegmentGFS. + +FIGURE 13/T.505 + +The body part of the generic logical structure – The passage and numbered segment levels + +![Figure 14/T.505: The body part of the generic logical structure – The paragraph level. This hierarchical diagram shows the structure from a dashed box 'Y' down to paragraph-level elements. 'Y' connects to ParagraphGFS. ParagraphGFS branches into BodyText, Footnote, BodyGeometric, and BodyRaster. Footnote connects to FootnoteGFS. FootnoteGFS branches into FootnoteReference and FootnoteBody. FootnoteBody connects to FootnoteBodyGFS. FootnoteBodyGFS branches into FootnoteNumber and FootnoteText.](0a73b03fba21af142d619a9a662e6490_img.jpg) + +``` + +graph TD + Y[Y] --> PG[ParagraphGFS] + PG --> BT[BodyText] + PG --> FN[Footnote] + PG --> BG[BodyGeometric] + PG --> BR[BodyRaster] + FN --> FNG[FootnoteGFS] + FNG --> FR[FootnoteReference] + FNG --> FNB[FootnoteBody] + FNB --> FNBG[FootnoteBodyGFS] + FNBG --> FNN[FootnoteNumber] + FNBG --> FNT[FootnoteText] + +``` + +T0810730-92/d14 + +Figure 14/T.505: The body part of the generic logical structure – The paragraph level. This hierarchical diagram shows the structure from a dashed box 'Y' down to paragraph-level elements. 'Y' connects to ParagraphGFS. ParagraphGFS branches into BodyText, Footnote, BodyGeometric, and BodyRaster. Footnote connects to FootnoteGFS. FootnoteGFS branches into FootnoteReference and FootnoteBody. FootnoteBody connects to FootnoteBodyGFS. FootnoteBodyGFS branches into FootnoteNumber and FootnoteText. + +FIGURE 14/T.505 + +The body part of the generic logical structure – The paragraph level + +![Diagram showing the common part of the generic logical structure. A hierarchy starting with CommonContent, followed by CommonContentGFS, which branches into CommonText, CommonRaster, CommonGeometric, and PageNumber.](89f8aefc01866631793087542316cef2_img.jpg) + +``` + +graph TD + CommonContent[CommonContent] -- CommonContentGFS --> CommonText[CommonText] + CommonContent -- CommonContentGFS --> CommonRaster[CommonRaster] + CommonContent -- CommonContentGFS --> CommonGeometric[CommonGeometric] + CommonContent -- CommonContentGFS --> PageNumber[PageNumber] + +``` + +T0810740-92/d15 + +Diagram showing the common part of the generic logical structure. A hierarchy starting with CommonContent, followed by CommonContentGFS, which branches into CommonText, CommonRaster, CommonGeometric, and PageNumber. + +FIGURE 15/T.505 +The common part of the generic logical structure + +### 7.1.2 Diagrams of relationships of layout constituents + +![Diagram showing the layout structure – Document root and page sets. A hierarchy starting with DocumentLauoutRoot, followed by DocLayRootGFS, then PageSet, and PageSetGFS. PageSetGFS branches into Page, RectoPage or VersoPage, and VersoPage or RectoPage. Each of these branches leads to a dashed box containing the letter 'P'.](9e8ebf03cae78f4f81b697548c2d7250_img.jpg) + +``` + +graph TD + DocumentLauoutRoot[DocumentLauoutRoot] -- DocLayRootGFS --> PageSet[PageSet] + PageSet -- PageSetGFS --> Page[Page] + PageSet -- PageSetGFS --> RectoPage[RectoPage or VersoPage] + PageSet -- PageSetGFS --> VersoPage[VersoPage or RectoPage] + Page -.-> P1[P] + RectoPage -.-> P2[P] + VersoPage -.-> P3[P] + +``` + +T0810750-92/d16 + +Diagram showing the layout structure – Document root and page sets. A hierarchy starting with DocumentLauoutRoot, followed by DocLayRootGFS, then PageSet, and PageSetGFS. PageSetGFS branches into Page, RectoPage or VersoPage, and VersoPage or RectoPage. Each of these branches leads to a dashed box containing the letter 'P'. + +FIGURE 16/T.505 +The layout structure – Document root and page sets + +![Figure 17/T.505: The layout structure – The page structure. A hierarchical tree diagram showing the structure of a page layout. The root node is 'P' (dashed box), which connects to 'PageSetGFS'. 'PageSetGFS' branches into 'BasicHeader', 'CompositeHeader', 'BasicFooter', and 'CompositeFooter'. 'CompositeHeader' and 'CompositeFooter' both connect to 'Q' (dashed box). 'PageSetGFS' also connects to 'BasicBody' and 'VariableComposite-Body'. 'VariableComposite-Body' connects to 'VariableCompositeBodyGFS', which then branches into 'BasicFloat', 'SynchronizedColumns', 'SnakingColumns', and 'FootnoteArea'. 'SynchronizedColumns' connects to 'Synchronized ColumnsGFS', which then connects to 'ColumnFixed'. 'SnakingColumns' connects to 'Snaking ColumnsGFS', which then connects to 'ColumnVariable'. The identifier 'T0810760-92/d17' is located at the bottom right of the diagram.](a2251e3bbfcd726b68cc50b091e53b02_img.jpg) + +``` + +graph TD + P[P] --- PageSetGFS[PageSetGFS] + PageSetGFS --- BasicHeader[BasicHeader] + PageSetGFS --- CompositeHeader[CompositeHeader] + PageSetGFS --- BasicFooter[BasicFooter] + PageSetGFS --- CompositeFooter[CompositeFooter] + CompositeHeader --- Q1[Q] + CompositeFooter --- Q2[Q] + PageSetGFS --- BasicBody[BasicBody] + PageSetGFS --- VariableCompositeBody[VariableComposite-Body] + VariableCompositeBody --- VariableCompositeBodyGFS[VariableCompositeBodyGFS] + VariableCompositeBodyGFS --- BasicFloat[BasicFloat] + VariableCompositeBodyGFS --- SynchronizedColumns[SynchronizedColumns] + VariableCompositeBodyGFS --- SnakingColumns[SnakingColumns] + VariableCompositeBodyGFS --- FootnoteArea[FootnoteArea] + SynchronizedColumns --- SynchronizedColumnsGFS[Synchronized ColumnsGFS] + SnakingColumns --- SnakingColumnsGFS[Snaking ColumnsGFS] + SynchronizedColumnsGFS --- ColumnFixed[ColumnFixed] + SnakingColumnsGFS --- ColumnVariable[ColumnVariable] + +``` + +T0810760-92/d17 + +Figure 17/T.505: The layout structure – The page structure. A hierarchical tree diagram showing the structure of a page layout. The root node is 'P' (dashed box), which connects to 'PageSetGFS'. 'PageSetGFS' branches into 'BasicHeader', 'CompositeHeader', 'BasicFooter', and 'CompositeFooter'. 'CompositeHeader' and 'CompositeFooter' both connect to 'Q' (dashed box). 'PageSetGFS' also connects to 'BasicBody' and 'VariableComposite-Body'. 'VariableComposite-Body' connects to 'VariableCompositeBodyGFS', which then branches into 'BasicFloat', 'SynchronizedColumns', 'SnakingColumns', and 'FootnoteArea'. 'SynchronizedColumns' connects to 'Synchronized ColumnsGFS', which then connects to 'ColumnFixed'. 'SnakingColumns' connects to 'Snaking ColumnsGFS', which then connects to 'ColumnVariable'. The identifier 'T0810760-92/d17' is located at the bottom right of the diagram. + +FIGURE 17/T.505 +The layout structure – The page structure + +![Figure 18/T.505: The layout structure – The header and footer frame structure. A hierarchical tree diagram showing the structure of header and footer frames. The root node is 'Q' (dashed box), which connects to 'HeaderFooterGFS'. 'HeaderFooterGFS' branches into 'SourcedContent-Variable', 'ArrangedContent-Variable', 'SourcedContent-Fixed', and 'ArrangedContent-Fixed'. 'ArrangedContent-Variable' and 'ArrangedContent-Fixed' both connect to 'GenericBlock'. The identifier 'T0810770-92/d18' is located at the bottom right of the diagram.](675af5bb2357ce5b510e613d04f66bdc_img.jpg) + +``` + +graph TD + Q[Q] --- HeaderFooterGFS[HeaderFooterGFS] + HeaderFooterGFS --- SourcedContentVariable[SourcedContent-Variable] + HeaderFooterGFS --- ArrangedContentVariable[ArrangedContent-Variable] + HeaderFooterGFS --- SourcedContentFixed[SourcedContent-Fixed] + HeaderFooterGFS --- ArrangedContentFixed[ArrangedContent-Fixed] + ArrangedContentVariable --- GenericBlock1[GenericBlock] + ArrangedContentFixed --- GenericBlock2[GenericBlock] + +``` + +T0810770-92/d18 + +Figure 18/T.505: The layout structure – The header and footer frame structure. A hierarchical tree diagram showing the structure of header and footer frames. The root node is 'Q' (dashed box), which connects to 'HeaderFooterGFS'. 'HeaderFooterGFS' branches into 'SourcedContent-Variable', 'ArrangedContent-Variable', 'SourcedContent-Fixed', and 'ArrangedContent-Fixed'. 'ArrangedContent-Variable' and 'ArrangedContent-Fixed' both connect to 'GenericBlock'. The identifier 'T0810770-92/d18' is located at the bottom right of the diagram. + +FIGURE 18/T.505 +The layout structure – The header and footer frame structure + +### 7.1.3 Notation + +This subclause is written in accordance with the Document Application Profile Proforma and Notation (DAPPN) of CCITT Rec. T.411 | ISO/IEC 8613-1, Annex F. The following clarifications and minor extensions apply: + +- a) [Clarification] + +The value range definition for the attributes “subordinates” and “imaging order” specify the set of object instances that may occur. The ordering and number (which may be zero) of object instances for the attribute “subordinates” shall be in accordance with the value of the attribute “generator for subordinates” in the respective object class. + +#### b) [Clarification] + +The value 'ANY\_STRING' may include code extension control functions as well as graphic characters. + +#### c) [Extension] + +In order to write the specification of the usage of character sets and code extension control functions precisely, the following extensions are applied: + +- 1) Table 3 defines the symbols that are introduced to denote shift functions. + +TABLE 3/T.505 + +**Symbols to denote shift functions** + +| Symbol | Shift function | Coded representation | +|--------|---------------------------|----------------------| +| LS0 | Locking shift zero | 00/15 | +| LS1R | Locking shift one right | ESC 07/14 | +| LS2R | Locking shift two right | ESC 07/13 | +| LS3R | Locking shift three right | ESC 07/12 | +| SS2 | Single shift two | 08/14 | +| SS3 | Single shift three | 08/15 | + +- 2) <escape-sequence> is extended to include shift functions: + +<escape-sequence>::='ESC'<octet>...[<invocation-control-function>]; + +<invocation-control-function>::='LS0'|'LS1R'|'LS2R'|'LS3R'|'SS2'|'SS3'; + +- 3) Data type specification for #ESC in content information is extended as: + +<escape-sequence>... + +#### d) [Clarification] + +When an attribute value is specified by a set of production rules, a non-terminal symbol which occurs first is its start symbol. Note that start symbols other than <object-id-expr>, <string-expr> and <construction-expr> are used. + +#### e) [Extension] + +Data type specifications other than those specified in the tables in DAPPN are applied for some attributes within the range that the base standards permit. + +#### f) [Extension] + +'|' is used in CASE SUPERIOR expressions in the following format in order to shorten the text: + +CASE SUPERIOR ( {const1|const2|...|constn} (aaaa) ) OF {.....} + +where “const1, const2, ... , constn” are names of constituent constraints, and “aaaa” is the name of an attribute. + +This expression is equivalent to the following expression: + +CASE SUPERIOR (const1(aaaa) ) OF {.....} + +CASE SUPERIOR (const2(aaaa) ) OF {.....} + +..... + +CASE SUPERIOR (constn(aaaa) ) OF {.....} + +When CASE SUPERIOR is evaluated, constituents are searched from the immediate superior to the root. Only the first one which satisfies one of the constituent constraints const1, const2, .... and constn is selected, and the attribute “aaaa” in it is tested. + +## 7.2 Document profile constituent constraints + +### 7.2.1 Macro definitions + +``` + +DEFINE(FC, "ASN.1{2 8 2 6 0}" -- formatted character content --) +DEFINE(PC, "ASN.1{2 8 2 6 1}" -- processable character content --) +DEFINE(FPC, "ASN.1{2 8 2 6 2}" -- formatted processable character content --) +DEFINE(FPR, "ASN.1{2 8 2 7 2}" -- formatted processable raster graphics content --) +DEFINE(FPG, "ASN.1{2 8 2 8 0}" -- formatted processable geometric graphics content --) +DEFINE(FDA, "{formatted}") +DEFINE(PDA, "{processable}") +DEFINE(FPDA, "{formatted-processable}") +DEFINE(PDA-FPDA, "{processable}'formatted processable}") +DEFINE(DAC, "DocumentProfile (Document-architecture-class)") + +DEFINE(NominalPageSizes, " + REQ #horizontal-dimension {7015}, + REQ #vertical-dimension {9920} -- ISO A5 portrait -- +|REQ #horizontal-dimension {9920}, + REQ #vertical-dimension {7015} -- ISO A5 landscape -- +|REQ #horizontal-dimension {9920}, + REQ #vertical-dimension {14030} -- ISO A4 portrait -- +|REQ #horizontal-dimension {14030}, + REQ #vertical-dimension {9920} -- ISO A4 landscape -- +|REQ #horizontal-dimension {14030}, + REQ #vertical-dimension {19840} -- ISO A3 portrait -- +|REQ #horizontal-dimension {19840}, + REQ #vertical-dimension {14030} -- ISO A3 landscape -- +|REQ #horizontal-dimension {12141}, + REQ #vertical-dimension {17196} -- JIS B4 (Japanese legal) portrait -- +|REQ #horizontal-dimension {17196}, + REQ #vertical-dimension {12141} -- JIS B4 (Japanese legal) landscape -- +|REQ #horizontal-dimension {8598}, + REQ #vertical-dimension {12141} -- JIS B5 (Japanese letter) portrait -- +|REQ #horizontal-dimension {12141}, + REQ #vertical-dimension {8598} -- JIS B5 (Japanese letter) landscape -- +|REQ #horizontal-dimension {10200}, + REQ #vertical-dimension {16800} -- ANSI legal portrait -- +|REQ #horizontal-dimension {16800}, + REQ #vertical-dimension {10200} -- ANSI legal landscape -- +|REQ #horizontal-dimension {10200}, + REQ #vertical-dimension {13200} -- ANSI-A portrait -- +|REQ #horizontal-dimension {13200}, + REQ #vertical-dimension {10200} -- ANSI-A landscape -- +|REQ #horizontal-dimension {13200}, + REQ #vertical-dimension {20400} -- ANSI-B portrait -- +|REQ #horizontal-dimension {20400}, + REQ #vertical-dimension {13200} -- ANSI-B landscape -- + ") + +DEFINE(GRAPHICRENDITIONS, " + {'cancel'}'increased-intensity' + {'italicized'}'underlined'}'crossed-out' + {'primary-font'}'first-alternative-font' + {'second-alternative-font'}'third-alternative-font' + {'fourth-alternative-font'}'fifth-alternative-font' + {'sixth-alternative-font'}'seventh-alternative-font' + {'eighth-alternative-font'}'ninth-alternative-font' + {'doubly-underlined'}'normal-intensity' + {'not-italicized'}'not-underlined'}'not-crossed-out'}... + ") + +``` + +-- Macro defining permissible code extension announcers. Note that all the values are basic. -- + +``` +DEFINE(CDEXTEN,"ESC 02/00 05/00, -- LSO -- + [ESC 02/00 05/03], -- LSR1 -- + [ESC 02/00 05/05], -- LSR2 -- + [ESC 02/00 05/07], -- LSR3 -- + [ESC 02/00 05/10], -- SS2 -- + [ESC 02/00 05/11] -- SS3 -- + ") +``` + +-- Macro defining code extension announcers for document application profile defaults -- + +``` +DEFINE(DAP-DEFAULT-CDEXTEN, "SCDEXTEN") +``` + +-- Macros defining final character for designation -- + +``` +DEFINE(FCORE, "04/02 -- A final character designating ISO-IR 6 (the IRV of ISO/IEC 646, i.e ASCII) --") +``` + +``` +DEFINE(F646, "-- A final character designating any version of ISO/IEC 646 except, ISO-IR 6 --") +``` + +``` +DEFINE(F94S, "-- A final character designating any registered 94 single byte graphic character set, optionally +preceded by one or more intermediate characters as defined in Annex C of ISO 2022 --") +``` + +``` +DEFINE(F94M, "-- A final character designating any registered 94 multi byte graphic character set, optionally +preceded by one or more intermediate characters as defined in Annex C of ISO 2022 --") +``` + +``` +DEFINE(F96S, "-- A final character designating any registered 96 single byte graphic character set, optionally +preceded by one or more intermediate characters as defined in Annex C of ISO 2022 --") +``` + +``` +DEFINE(F96M, "-- A final character designating any registered 96 multi byte graphic character set, optionally +preceded by one or more intermediate characters as defined in Annex C of ISO 2022 --") +``` + +``` +DEFINE(FEMPTY, "07/14 -- The empty set --") +``` + +-- Macro defining a revision number of a character set -- + +``` +DEFINE (REV,"-- An octet between 04/00 and 07/14 which represents a revision number as defined in ISO 2022 --") +``` + +-- Macro defining designation sequences -- + +``` +DEFINE(DEG-CORE-G0, "ESC 02/08 $FCORE") +-- Designate the 94 characters of ISO-IR 6 (the IRV of ISO/IEC 646) to G0 -- +``` + +``` +DEFINE(DEG-646-G0, "ESC 02/08 $F646") +-- Designate any version of ISO/IEC 646, except ISO-IR 6, to G0 -- +``` + +``` +DEFINE(DEG-ANY-G1, "{ [ESC 02/06 $REV] {ESC 02/09 $F94S +|ESC 02/04 02/09 $F94M +|ESC 02/13 $F96S +|ESC 02/04 02/13 $F96M}}") +-- Designate any character set to G1 -- +``` + +``` +DEFINE(DEG-ANY-G2, "{ [ESC 02/06 $REV] {ESC 02/10 $F94S +|ESC 02/04 02/10 $F94M +|ESC 02/14 $F96S +|ESC 02/04 02/14 $F96M}}") +-- Designate any character set to G2 -- +``` + +``` +DEFINE(DEG-ANY-G3, "{ [ESC 02/06 $REV] {ESC 02/11 $F94S +|ESC 02/04 02/11 $F94M +|ESC 02/15 $F96S +|ESC 02/04 02/15 $F96M}}") +-- Designate any character set to G3 -- +``` + +``` +DEFINE(DEG-EMPTY-G1, "ESC 02/09 $FEMPTY") +-- Designate the empty set to G1 -- +``` + +-- Macro defining permissible graphic character sets -- + +``` + +DEFINE(PERMIT-GRCHAR, " {$DEG-CORE-G0 LS0 + |$DEG-646-G0 LS0}, + {{$DEG-ANY-G1 LS1R + |$DEG-ANY-G2 LS2R + |$DEG-ANY-G3 LS3R}... + |$DEG-EMPTY-G1 LS1R} ") + +``` + +*-- Macro defining graphic character sets for document application profile defaults --* + +``` + +DEFINE(DAP-DEFAULT-GRCHAR, "$PERMIT-GRCHAR") + +``` + +*-- Macro defining basic character sets. Note that this macro is defined for clarification of the specification and is not used in any other part of this document application profile specification --* + +``` + +DEFINE(BASIC-GRCHAR, " $DEG-CORE-G0 LS0, + $DEG-EMPTY-G1 LS1R ") + +``` + +*-- Macro defining non-basic graphic character sets --* + +``` + +DEFINE(NON-BASIC-GRCHAR, " {$DEG-646-G0 + |$DEG-ANY-G1 + |$DEG-ANY-G2 + |$DEG-ANY-G3}... ") + +``` + +*-- Macro defining character sets used in document profile attributes --* + +``` + +DEFINE(PROFCHAR, " + +``` + +``` + +ESC 02/00 04/03 -- announcement of use of G0 and G1, and invocation into GL and GR + respectively. (No shift functions are necessary.) -- +{$DEG-CORE-G0|$DEG-646-G0} -- designate G0 -- +{$DEG-ANY-G1|$DEG-EMPTY-G1} -- designate G1 -- +") + +``` + +*-- Macro defining comments character sets --* + +``` + +DEFINE(COMCHAR," + +``` + +*-- in the case to use both GL and GR without shift functions --* + +``` + +ESC 02/00 04/03 -- announcement of use of G0 and G1, and invocation into GL and GR + respectively. (No shift functions are necessary.) -- +{$DEG-CORE-G0|$DEG-646-G0} -- designate G0 -- +{$DEG-ANY-G1|$DEG-EMPTY-G1} -- designate G1 -- + +``` + +*-- in the case of use of various character sets (shift functions are necessary) --* + +``` + +{ESC 02/00 05/00, -- announcement to use G0 and LS0 -- +[ESC 02/00 05/03], -- announcement to use G1 and LS1R -- +[ESC 02/00 05/05], -- announcement to use G2 and LS2R -- +[ESC 02/00 05/07], -- announcement to use G3 and LS3R -- +[ESC 02/00 05/10], -- announcement to use G2 and SS2 -- +[ESC 02/00 05/11] } -- announcement to use G3 and SS3 -- + +{$DEG-CORE-G0|$DEG-646-G0} -- designate G0 -- +{{$DEG-ANY-G1 -- designate G1 -- +|$DEG-ANY-G2 -- designate G2 -- +|$DEG-ANY-G3} -- designate G3 -- +|$DEG-EMPTY-G1} +") + +``` + +*-- Macro defining character sets used for alternative representation --* + +``` + +DEFINE(ALTCHAR, "$PROFCHAR") + +``` + +### 7.2.2 Constituents constraints + +#### 7.2.2.1 DocumentProfile { + +CASE \$DAC OF { + +\$FDA:        PERM Generic-layout-structure        {'factor-set'}, +              PERM Specific-layout-structure        {'present'}, +              -- shall be present in the case of specific document -- +              -- and shall not be present in the case of generic document -- +              PERM Presentation-styles            {'present'} + +\$PDA:        PERM Generic-layout-structure        {'complete-generator-set'}, +              PERM Generic-logical-structure        {'complete-generator-set' +                                                      |'partial-generator-set'}, +              -- shall be present if there is no external document class reference -- +              PERM Specific-logical-structure        {'present'}, +              -- shall be present in the case of complete document -- +              -- and shall not be present in the case of generic document -- +              PERM Presentation-styles            {'present'}, +              PERM Layout-styles                  {'present'} + +\$FPDA:       PERM Generic-layout-structure        {'complete-generator-set'}, +              -- shall be present if there is no external document class reference -- +              PERM Specific-layout-structure        {'present'}, +              -- shall be present in the case of complete document -- +              -- and shall not be present in the case of generic document -- +              PERM Generic-logical-structure        {'complete-generator-set' +                                                      |'partial-generator-set'}, +              -- shall be present if there is no external document class reference -- +              PERM Specific-logical-structure        {'present'}, +              -- shall be present in the case of complete document -- +              -- and shall not be present in the case of generic document -- +              PERM Presentation-styles            {'present'}, +              PERM Layout-styles                  {'present'} + +              }, + +PERM External-document-class                    ANY\_VALUE}, + +PERM Resource-document                         ANY\_VALUE}, + +PERM Resources                    {MUL{REQ #resource-identifier {ANY\_VALUE}, +                                                      REQ #resource-object-class-identifier {ANY\_VALUE}}}, + +-- document characteristics -- + +REQ Document-application-profile {-- see clause 8 for a definition of the permitted values for this attribute --}, + +PERM Document-application-profile-defaults { + +CASE \$DAC OF { + +\$FDA :{PERM #content-architecture-class {SFC}\$FPC} +\$PDA :{PERM #content-architecture-class {SFC}\$PC}\$FPC} +\$FPDA :{PERM #content-architecture-class {SFC}\$FPC} +              }, + +PERM #dimensions                                {REQ #horizontal-dimension +                                                      {REQ #fixed-dimension {<=14030}}, +REQ #vertical-dimension +                                                      {REQ #fixed-dimension {<=19840}} +                                                      -- up to ISO A3 portrait -- + +                                                      |REQ #horizontal-dimension +                                                      {REQ #fixed-dimension {<=19840}}, +REQ #vertical-dimension +                                                      {REQ #fixed-dimension {<=14030}} +                                                      -- up to ISO A3 landscape -- + +                                                      |REQ #horizontal-dimension +                                                      {REQ #fixed-dimension {<=13200}}, +REQ #vertical-dimension + +{REQ #fixed-dimension {<=20400}} +-- up to ANSI-B portrait -- + +|REQ #horizontal-dimension +{REQ #fixed-dimension {<=20400}}, +REQ #vertical-dimension +{REQ #fixed-dimension {<=13200}} +-- up to ANSI-B landscape --}, + +**PERM #medium-type** {PERM #nominal-page-size{\$NominalPageSizes}, +PERM #side-of-sheet {ANY\_VALUE}}, + +**PERM #page-position** {ANY\_VALUE}, + +**PERM #layout-path** {'0-degrees'|'180-degrees'|'270-degrees'}, + +**PERM #type-of-coding** {ASN.1{2 8 3 6 0} -- character encoding -- +|ASN.1{2 8 3 7 0} -- T.6 encoding -- +|ASN.1{2 8 3 7 1} -- T.4 one dimensional encoding -- +|ASN.1{2 8 3 7 2} -- T.4 two dimensional encoding -- +|ASN.1{2 8 3 7 3} -- bitmap encoding -- +|ASN.1{2 8 3 8 0} -- geometric encoding --}, + +**PERM #character-content-defaults {** +**PERM #alignment** {ANY\_VALUE}, +**PERM #character-fonts** {ANY\_VALUE}, +**PERM #character-path** {ANY\_VALUE}, +**PERM #character-spacing** {ANY\_VALUE}, +**PERM #character-orientation** {'0-degrees' | '90-degrees'}, +**PERM #code-extension-announcers** {\$DAP-DEFAULT-CDEXTEN}, +**PERM #first-line-offset** {ANY\_VALUE}, +**PERM #graphic-character-sets** {\$DAP-DEFAULT-GRCHAR}, +**PERM #graphic-character-sub-repertoire** {ANY\_VALUE}, +**PERM #graphic-rendition** {\$GRAPHICRENDITIONS}, +**PERM #indentation** {ANY\_VALUE}, +**PERM #initial-offset** {ANY\_VALUE}, +**PERM #itemization** {ANY\_VALUE}, +**PERM #kerning-offset** {ANY\_VALUE}, +**PERM #line-layout-table** {ANY\_VALUE}, +**PERM #line-progression** {ANY\_VALUE}, +**PERM #line-spacing** {ANY\_VALUE}, +**PERM #orphan-size** {ANY\_VALUE}, +**PERM #proportional-line-spacing** {ANY\_VALUE}, +**PERM #widow-size** {ANY\_VALUE}}, + +**PERM #raster-graphics-content-defaults {** +**PERM #image-dimensions** {ANY\_VALUE}, +**PERM #pel-spacing** {ANY\_VALUE}, +**PERM #spacing-ratio** {ANY\_VALUE}, +**PERM #compression** {ANY\_VALUE}}}, + +**REQ Document-architecture-class** {\$FDA|\$PDA|\$FPDA}, + +**REQ Content-architecture-classes** {[\$FC],[\$PC],[\$FPC],[\$FPR],[\$FPG]}, + +**REQ Interchange-format-class** { -- see clause 8 for a definition of the permitted values for this attribute --}, + +**REQ Oda-version** {REQ #standard-or-recommendation{"CCITT Rec. T.410 +Series(1988)|ISO 8613(1989); version 1.1"}, +REQ #publication-date{1992-01-01}}, + +-- non basic document characteristics -- + +**PERM Profile-character-sets** {\$PROFCHAR}, + +**PERM Comments-character-sets** {\$COMCHAR}, + +**PERM Alternative-representation-character-sets** {\$ALTCHAR}, + +**PERM Page-dimensions {PMUL** +{REQ #horizontal-dimension +{REQ #fixed-dimension {<=14030}}, +REQ #vertical-dimension +{REQ #fixed-dimension {12401..19840}} + +|REQ #horizontal-dimension + {REQ #fixed-dimension {9241..14030}}, + REQ #vertical-dimension + {REQ #fixed-dimension {<=19840}} + -- up to ISO A3 portrait -- + +|REQ #horizontal-dimension + {REQ #fixed-dimension {12401..19840}}, + REQ #vertical-dimension + {REQ #fixed-dimension {<=14030}} + |REQ #horizontal-dimension + {REQ #fixed-dimension {<=19840}}, + REQ #vertical-dimension + {REQ #fixed-dimension {9241..14030}} + -- up to ISO A3 landscape -- + +|REQ #horizontal-dimension + {REQ #fixed-dimension {<=13200}}, + REQ #vertical-dimension + {REQ #fixed-dimension {12401..20400}} + |REQ #horizontal-dimension + {REQ #fixed-dimension {9241..13200}}, + REQ #vertical-dimension + {REQ #fixed-dimension {<=20400}} + -- up to ANSI-B portrait -- + +|REQ #horizontal-dimension + {REQ #fixed-dimension {12401..20400}}, + REQ #vertical-dimension + {REQ #fixed-dimension {<=13200}} + |REQ #horizontal-dimension + {REQ #fixed-dimension {<=20400}}, + REQ #vertical-dimension + {REQ #fixed-dimension {9241..13200}} + -- up to ANSI-B landscape -- }, + +-- any value of dimensions which is greater than the common assured reproduction area of ISO A4 and + -- ANSI-A is non-basic -- + +PERM Medium-types {PMUL + {PERM #nominal-page-size{\$NominalPageSizes}, + PERM #side-of-sheet{'recto'|'verso'}}}, + +-- all values of "medium type" are non-basic -- + +PERM Layout-paths {{'0-degrees'|'90-degrees'|'180-degrees'}...}, + +PERM Borders {ANY\_VALUE}, + +PERM Coding-attributes { + +PERM #raster-graphics-coding-attributes { + PERM #compression {uncompressed}}}, + +PERM Presentation-features { + PERM #character-presentation-features { + PERM #character-orientation {'90-degrees'}, + PMUL {PERM #character-path + {'90-degrees' + '|180-degrees' + '|270-degrees'}}}, + +PMUL {PERM #character-spacing {<100|100|160|200}}, + -- only values <100 are required to be specified. Values 100, 160 200 need not be declared and are only + -- permitted to be specified for upwards compatibility from PM-11 -- + +PMUL {PERM #graphic-character-sets {NON-BASIC-GRCHAR}}, + PMUL {PERM #graphic-character-sub-repertoire {ANY\_VALUE}}, + PMUL {PERM #graphic-rendition {'crossed-out'|'not-crossed-out'}}, + +-- values need not be declared and are only permitted to be specified for upwards compatibility from PM-11 -- + +PMUL {PERM #line-spacing {ANY\_VALUE} + EXCEPT{200,300,400}}, + +-- value 150 need not be declared and is only permitted to be specified for upwards compatibility from PM-11 -- + +``` + + PERM #line-progression {'90-degrees'}}, +PERM #raster-graphics-presentation-features { + PMUL {PERM #pel-spacing {ANY_VALUE} + EXCEPT{16,12,8,6,5,4,3,2,1}} + } +-- Any value of #pel spaces is permitted as basic -- +-- Basic values of #length are multiples of #pel spaces as listed -- }, + +-- additional document characteristics -- + + PERM Fonts-lis {PMUL{REQ #font-identifier {ANY_VALUE}, + REQ #font-reference {ANY_VALUE}}}, + +-- document management attributes -- + +-- document description -- +PERM Title {ANY_STRING}, +PERM Subject {ANY_STRING}, +PERM Document-type {ANY_STRING}, +PERM Abstract {ANY_STRING}, +PERM Keywords {ANY_STRING...}, +REQ Document-reference {ANY_VALUE}, + +-- dates and times -- +PERM Document-date-and-time {ANY_STRING}, +PERM Creation-date-and-time {ANY_STRING}, +PERM Local-filing-date-and-time {ANY_VALUE}, +PERM Expiry-date-and-time {ANY_STRING}, +PERM Start-date-and-time {ANY_STRING}, +PERM Purge-date-and-time {ANY_STRING}, +PERM Release-date-and-time {ANY_STRING}, +PERM Revision-history {ANY_VALUE}, + +-- originators -- +PERM Organizations {ANY_STRING...}, +PERM Owners {ANY_VALUE}, +PERM Preparers {ANY_VALUE}, +PERM Authors {ANY_VALUE}, + +-- other user information -- +PERM Copyright {ANY_VALUE}, +PERM Status {ANY_STRING}, +PERM User-specific-codes {ANY_STRING...}, +PERM Distribution-list {ANY_VALUE}, +PERM Additional-information {ANY_VALUE}, +-- external references -- +PERM References-to-other-documents {ANY_VALUE}, +PERM Superseded-documents {ANY_VALUE}, + +-- local file references -- +PERM Local-file-references {ANY_VALUE}, + +-- content attributes -- +PERM Document-size {ANY_INTEGER}, +PERM Number-of-pages {ANY_INTEGER}, +PERM Languages {ANY_STRING...}, + +-- security information -- +PERM Authorization {ANY_VALUE}, +PERM Security-classification {ANY_STRING}, +PERM Access-rights {ANY_STRING...} + +``` + +## 7.3 Logical constituent constraints + +### 7.3.1 Macro definitions + +``` +DEFINE(DocLogRootGFS, " +<construction-expr> ::= <construction-term> + |<construction-type>; + +<construction-term> ::= <construction-factor> + |OPT <construction-factor> + |REP <construction-factor> + |OPT REP <construction-factor>; + +<construction-type> ::= SEQ({<construction-term>}...) + |CHO({<construction-term>}...); + +<construction-factor> ::= OBJECT_CLASS_ID_OF(Passage) + |<construction-type>; + ") + +DEFINE(CONSTRAINT-1, " +<constraint-1> ::= <construction-term> + |<construction-type>; + +<construction-term> ::= <construction-factor> + |OPT <construction-factor> + |REP <construction-factor> + |OPT REP <construction-factor>; + +<construction-type> ::= SEQ({<construction-term>}...) + |CHO({<construction-term>}...); + +<construction-factor> ::= OBJECT_CLASS_ID_OF(Paragraph) + |OBJECT_CLASS_ID_OF(BodyText) + |OBJECT_CLASS_ID_OF(BodyRaster) + |OBJECT_CLASS_ID_OF(BodyGeometric) + |<construction-type>; + ") + +DEFINE(CONSTRAINT-2, " +<constraint-2> ::= OBJECT_CLASS_ID_OF(NumberedSegment) + |OPT REP OBJECT_CLASS_ID_OF(NumberedSegment) + |REP OBJECT_CLASS_ID_OF(NumberedSegment) + |OPT OBJECT_CLASS_ID_OF(NumberedSegment); + ") + +DEFINE(PassageGFS, " +<construction-expr> ::= <constraint-1> + |<constraint-2> + |SEQ(<constraint-1><constraint-2>); + +$CONSTRAINT-1 +$CONSTRAINT-2 ") + +DEFINE(NumberedSegmentGFS, " +<construction-expr> ::= SEQ(<term-1>|<constraint-1>| + |<constraint-2>|); + +<term-1> ::= OBJECT_CLASS_ID_OF(Number); + +$CONSTRAINT-1 +$CONSTRAINT-2 ") + +DEFINE(ParagraphGFS, " +<construction-expr> ::= <construction-term> + |<construction-type>; + +<construction-term> ::= <construction-factor> + |OPT <construction-factor> + |REP <construction-factor> + |OPT REP <construction-factor>; + +<construction-type> ::= SEQ({<construction-term>}...) + |CHO({<construction-term>}...); +``` + +``` + +<construction-factor> ::= OBJECT_CLASS_ID_OF(BodyText) + |OBJECT_CLASS_ID_OF(BodyRaster) + |OBJECT_CLASS_ID_OF(BodyGeometric) + |OBJECT_CLASS_ID_OF(Footnote) + |<construction-type>; + ") + +DEFINE(FootnoteGFS, " +<construction-expr> ::= SEQ(OBJECT_CLASS_ID_OF(FootnoteReference) + OBJECT_CLASS_ID_OF(FootnoteBody)); + ") + +DEFINE(FootnoteBodyGFS, " +<construction-expr> ::= SEQ(OBJECT_CLASS_ID_OF(FootnoteNumber) + <term-1>); + +<term-1> ::= OBJECT_CLASS_ID_OF(FootnoteText) + |REP OBJECT_CLASS_ID_OF(FootnoteText) + |CHO({OBJECT_CLASS_ID_OF(FootnoteText)}...) + |REP CHO({OBJECT_CLASS_ID_OF(FootnoteText)}...); + ") + +DEFINE(CommonContentGFS, " +<construction-expr> ::= <construction-factor> + |SEQ(<construction-factor>...); + +<construction-factor> ::= OBJECT_CLASS_ID_OF(PageNumber) + |OBJECT_CLASS_ID_OF(CommonText) + |OBJECT_CLASS_ID_OF(CommonRaster) + |OBJECT_CLASS_ID_OF(CommonGeometric); + ") + +DEFINE(N, + "<n>::={""0""|""1""|""2""|""3""|""4""|""5""|""6""|""7""|""8""|""9""}...; + -- any string of characters from the set of characters: '0'... '9' -- + + -- Defines the prefix binding. This binding may be used to associate a string literal with an object or object class. + -- In addition, this binding is used to prefix text to another binding, such as a segment number, footnote number + -- or page number. The instances are differentiated by a suffix number. -- + ") + +DEFINE(PREFIX, " +<prefix> ::= ""prefix-""<n>; +$N + ") + +-- Defines the suffix binding. This binding may be used to associate a string literal with an object or object class. +-- In addition, this binding is used to suffix text to another binding, such as a segment number, footnote number +-- or page number. The instances are differentiated by a suffix number. -- + +DEFINE(SUFFIX, " +<suffix> ::= ""suffix-""<n>; +$N + ") + +-- Defines the separator binding. This binding is used to provide a separator character +-- for a hierarchical form of a segment number, footnote number or page number. +-- The instances are differentiated by a suffix number. -- + +DEFINE(SEPARATOR, " +<separator> ::= ""separator-""<n>; +$N + ") + +-- Defines the general number binding. This binding may be instantiated for use as the numeric value +-- for use such as in segment number, footnote number or page number bindings. +-- The instances are differentiated by a suffix number. -- + +DEFINE(NUMBER, " +<number> ::= ""number-""<n>; +$N + ") + +``` + +-- Defines the general number string binding. This binding may be instanced for use + -- as the string value such as for segment number, footnote number or page numbers. + -- The instances are differentiated by a suffix number. -- + +``` +DEFINE(NUMBERSTRING, " +<numberstring> ::= ""numberstring-""<n>; +$N +``` + +``` + ") +-- Used to initialise/specify any of the bindings. The bindings defined by this macro are permitted to: + - any logical object class + - any logical object + - any layout object class except frame classes and block classes, and + - any layout object except frames and blocks in the case of FPDA and FDA. -- +``` + +``` +DEFINE(INITIALISEANY, " + REQ #binding-name{$PREFIX}, + REQ #binding-value{ANY_STRING} + |REQ #binding-name{$SUFFIX}, + REQ #binding-value{ANY_STRING} + |REQ #binding-name{$SEPARATOR}, + REQ #binding-value{ANY_STRING} + |REQ #binding-name{$NUMBER}, + REQ #binding-value{>=0} + |REQ #binding-name{$NUMBERSTRING}, + REQ #binding-value{ANY_STRING} + ") +``` + +-- Used to make a simple or compound string out of the number bindings. -- + +``` +DEFINE(USENUMBERSTRINGS, " + REQ #binding-name{$NUMBERSTRING}, + REQ #binding-value{ + <string-expr>::=<hierarchic-expr>|<simple-expr>; +``` + +``` +<hierarchic-expr> ::= B_REF(SUP(CURR-OBJ))(<numberstring>) + |B_REF(SUP(CURR-OBJ))(<separator>) + |<simple-expr>; +``` + +``` +<simple-expr> ::= MK-STR(B_REF(CURR-OBJ))(<number>)) + |U-ALPHA(B_REF(CURR-OBJ))(<number>)) + |L-ALPHA(B_REF(CURR-OBJ))(<number>)) + |U-ROM(B_REF(CURR-OBJ))(<number>)) + |L-ROM(B_REF(CURR-OBJ))(<number>)) + |MK-STR(ORD(CURR-OBJ)) + |U-ALPHA(ORD(CURR-OBJ)) + |L-ALPHA(ORD(CURR-OBJ)) + |U-ROM(ORD(CURR-OBJ)) + |L-ROM(ORD(CURR-OBJ)) + |ANY_STRING; +``` + +``` +$NUMBERSTRING +$SEPARATOR +$NUMBER +} + ") +``` + +-- Used to increment any of the number bindings. -- + +``` +DEFINE(USENUMBERS, " + REQ #binding-name{$NUMBER}, + REQ #binding-value + {<num-expr>::=INC(B_REF(PREC(CURR-OBJ))(<number>)); +$NUMBER} + ") +``` + +-- This string expression is allowed in a content generator for Number to automatically +-- generate text for segment numbers. -- + +``` +DEFINE(SEGMENTNUMBER, " +``` + +``` + +<string-expr> ::= [<pre-str>]|<num-str>|[<suf-str>]; +<num-str> ::= B_REF(SUP(CURR-OBJ))(<numberstring>); +<pre-str> ::= B_REF(SUP(CURR-OBJ))(<prefix>) + |ANY_STRING; +<suf-str> ::= B_REF(SUP(CURR-OBJ))(<suffix>) + |ANY_STRING; + +$NUMBERSTRING +$PREFIX +$SUFFIX + + ") +-- Used to initialise fnotenumber and fnotestring bindings. -- + +DEFINE(INITIALISEFNOTE, " + REQ #binding-name{""fnotenumber""}, + REQ #binding-value{>=0} + ") + +-- Used to increment fnotenumber binding. -- + +DEFINE(INCFNOTENUMBER, " + REQ #binding-name{""fnotenumber""}, + REQ #binding-value{<num-expr>::=INC(B_REF(PREC + (CURR-OBJ))(""fnotenumber"")));} + ") + +-- Used to create a fnotestring from a fnotenumber binding. -- + +DEFINE(FNOTENUMBERSTRING, " +REQ #binding-name{""fnotestring""}, +REQ #binding-value{<str-expr> ::= + MK-STR(B_REF(CURR-OBJ))(""fnotenumber"")) + |U-ALPHA(B_REF(CURR-OBJ))(""fnotenumber"")) + |L-ALPHA(B_REF(CURR-OBJ))(""fnotenumber"")) + |U-ROM(B_REF(CURR-OBJ))(""fnotenumber"")) + |L-ROM(B_REF(CURR-OBJ))(""fnotenumber""));} + ") + +-- Used to reset the footnote number string to a string literal. This provides a mechanism for setting +-- the footnote number string to something other than a numeric value. -- + +DEFINE(FNOTESTRINGLITERAL, " + REQ #binding-name{""fnotestring""}, + REQ #binding-value{ANY_STRING} + ") + +-- This string expression is allowed in a content generator for FootnoteNumber and FootnoteReference +-- to automatically generate text for a footnote number. -- + +DEFINE(FNOTENUMBER, " +<string-expr> ::= [ANY_STRING]<num-str>[ANY_STRING]; +<num-str> ::= B_REF(SUP(CURR-OBJ))(""fnotestring""); + ") + +DEFINE(PGNUMBER , " +<string-expr> ::= [ANY_STRING]{<num-str>}[ANY_STRING]; + +<num-str> ::= MK-STR(<numeric-expr>) + |U-ALPHA(<numeric-expr>) + |L-ALPHA(<numeric-expr>) + |U-ROM(<numeric-expr>) + |L-ROM(<numeric-expr>); + +<numeric-expr> ::= B_REF(SUP(CURR-INST(<class-or-type-1>, + CURR-OBJ))(""PGnum"")) + +``` + +``` + +|B_REF(CURR-INST(<class-or-type-2>, +CURR-OBJ))("PGnum"); + +<class-or-type-1> ::= 'frame'; + +<class-or-type-2> ::= +|OBJECT_CLASS_ID_OF(Page) +|OBJECT_CLASS_ID_OF(RectoPage) +|OBJECT_CLASS_ID_OF(VersoPage); + +") + +``` + +### 7.3.2 Factor constraints + +#### 7.3.2.1 FACTOR ANY-LOGICAL { + +##### GENERIC: + +``` + +REQ Object-type {VIRTUAL}, +REQ Object-class-identifier {ANY_VALUE} + +``` + +##### SPECIFIC: + +``` + +PERM Object-type {VIRTUAL}, +REQ Object-identifier {ANY_VALUE}, +REQ Object-class {VIRTUAL} + +``` + +##### SPECIFIC\_AND\_GENERIC: + +``` + +PERM User-readable-comments {ANY_STRING}, +PERM User-visible-name {ANY_STRING} + +``` + +### 7.3.3 Constituent constraints + +#### 7.3.3.1 DocumentLogicalRoot: ANY-LOGICAL { + +##### GENERIC: + +``` + +REQ Object-type {'document-logical-root'}, +REQ Generator-for-subordinates {$DocLogRootGFS}, +REQ Application-comments {REQ #constraint-name {"0"}, +PERM #external-data {ANY_VALUE}} + +``` + +##### SPECIFIC: + +``` + +PERM Object-type {'document-logical-root'}, +REQ Object-class {OBJECT_CLASS_ID_OF (DocumentLogicalRoot)}, +REQ Subordinates {SUB_ID_OF(Passage)+}, +PERM Application-comments {REQ #constraint-name {"0"}, +PERM #external-data {ANY_VALUE}} + +``` + +##### SPECIFIC\_AND\_GENERIC: + +``` + +PERM Bindings {PMUL{$INITIALISEANY}, +PERM{$INITIALISEFNOTE}} + +``` + +#### 7.3.3.2 Passage: ANY-LOGICAL { + +##### GENERIC: + +``` + +REQ Object-type {'composite-logical-object'}, +REQ Generator-for-subordinates {$PassageGFS}, +REQ Application-comments {REQ #constraint-name {"1"}, +PERM #external-data {ANY_VALUE}} + +``` + +##### SPECIFIC: + +``` + +PERM Object-type {'composite-logical-object'}, +REQ Object-class {OBJECT_CLASS_ID_OF(Passage)}, +REQ Subordinates {SUB_ID_OF(NumberedSegment)+, +SUB_ID_OF(BodyText)+, +SUB_ID_OF(BodyRaster)+, +SUB_ID_OF(BodyGeometric)+, +SUB_ID_OF(Paragraph)+}, +PERM Application-comments {REQ #constraint-name {"1"}, +PERM #external-data {ANY_VALUE}} + +``` + +##### SPECIFIC\_AND\_GENERIC: + +``` + +PERM Layout-style {STYLE_ID_OF(L-Style1)}, +PERM Bindings {PMUL{$INITIALISEANY}, +PERM{$INITIALISEFNOTE}} + +``` + +#### 7.3.3.3 NumberedSegment: ANY-LOGICAL { + +##### GENERIC: + +| | | | +|-----|----------------------------|----------------------------------------------------------------------------| +| REQ | Object-type | {'composite-logical-object'}, | +| REQ | Generator-for-subordinates | {\$NumberedSegmentGFS}, | +| REQ | Application-comments | {REQ #constraint-name {"2"},<br>PERM #external-data {ANY_VALUE}}, | +| REQ | Bindings | {PMUL{\$INITIALISEANY},<br>PERM{\$USENUMBERS},<br>REQ{\$USENUMBERSTRINGS}} | + +-- The binding USE NUMBERS shall also be present if USENUMBERSTRINGS does not use the ORD option. -- + +##### SPECIFIC: + +| | | | +|------|----------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| PERM | Object-type | {'composite-logical-object'}, | +| REQ | Object-class | {OBJECT_CLASS_ID_OF(NumberedSegment)}, | +| REQ | Subordinates | {SUB_ID_OF(Number),<br>SUB_ID_OF(NumberedSegment)+,<br>SUB_ID_OF(BodyText)+,<br>SUB_ID_OF(BodyRaster)+,<br>SUB_ID_OF(BodyGeometric)+,<br>SUB_ID_OF(Paragraph)+}, | +| PERM | Bindings | {PMUL{\$INITIALISEANY}}, | +| PERM | Application-comments | {REQ #constraint-name {"2"},<br>PERM #external-data {ANY_VALUE}} | + +##### SPECIFIC\_AND\_GENERIC: + +| | | | +|------|--------------|-------------------------| +| PERM | Layout-style | {STYLE_ID_OF(L-Style4)} | +|------|--------------|-------------------------| + +#### 7.3.3.4 Number: ANY-LOGICAL { + +##### GENERIC: + +| | | | +|-----|----------------------|------------------------------------------------------------------| +| REQ | Object-type | {'basic-logical-object'}, | +| REQ | Content-generator | {\$SEGMENTNUMBER}, | +| REQ | Application-comments | {REQ #constraint-name {"3"},<br>PERM #external-data {ANY_VALUE}} | + +##### SPECIFIC: + +| | | | +|------|----------------------|------------------------------------------------------------------| +| PERM | Object-type | {'basic-logical-object'}, | +| REQ | Object-class | {OBJECT_CLASS_ID_OF(Number)}, | +| PERM | Application-comments | {REQ #constraint-name {"3"},<br>PERM #external-data {ANY_VALUE}} | + +##### SPECIFIC\_AND\_GENERIC: + +| | | | +|------|----------------------------|--------------------------| +| PERM | Layout-style | {STYLE_ID_OF(L-Style2)}, | +| PERM | Presentation-style | {STYLE_ID_OF(P-Style1)}, | +| PERM | Content-architecture-class | {\$FC SPC \$FPC}} | + +#### 7.3.3.5 Paragraph: ANY-LOGICAL { + +##### GENERIC: + +| | | | +|-----|----------------------------|------------------------------------------------------------------| +| REQ | Object-type | {'composite-logical-object'}, | +| REQ | Generator-for-subordinates | {\$ParagraphGFS}, | +| REQ | Application-comments | {REQ #constraint-name {"6"},<br>PERM #external-data {ANY_VALUE}} | + +##### SPECIFIC: + +| | | | +|------|----------------------|-----------------------------------------------------------------------------------------------------------| +| PERM | Object-type | {'composite-logical-object'}, | +| REQ | Object-class | {OBJECT_CLASS_ID_OF(Paragraph)}, | +| REQ | Subordinates | {SUB_ID_OF(BodyText)+,<br>SUB_ID_OF(Footnote)+,<br>SUB_ID_OF(BodyRaster)+,<br>SUB_ID_OF(BodyGeometric)+}, | +| PERM | Application-comments | {REQ #constraint-name {"6"},<br>PERM #external-data {ANY_VALUE}} | + +##### SPECIFIC\_AND\_GENERIC: + +| | | | +|------|--------------|-------------------------| +| PERM | Layout-style | {STYLE_ID_OF(L-Style4)} | +|------|--------------|-------------------------| + +#### 7.3.3.6 BodyText: ANY-LOGICAL { + +##### GENERIC: + +| | | | +|-----|-------------|---------------------------| +| REQ | Object-type | {'basic-logical-object'}, | +|-----|-------------|---------------------------| + +| | | | +|------|----------------------|-------------------------------------------------------------------| +| PERM | Resource | {ANY_VALUE}, | +| REQ | Application-comments | {REQ #constraint-name {"14"},<br>PERM #external-data {ANY_VALUE}} | + +##### **SPECIFIC:** + +| | | | +|------|----------------------|-------------------------------------------------------------------| +| PERM | Object-type | {'basic-logical-object'}, | +| REQ | Object-class | {OBJECT_CLASS_ID_OF(BodyText)}, | +| PERM | Application-comments | {REQ #constraint-name {"14"},<br>PERM #external-data {ANY_VALUE}} | + +##### **SPECIFIC\_AND\_GENERIC:** + +| | | | +|------|----------------------------|---------------------------------------------| +| PERM | Layout-style | {STYLE_ID_OF(L-Style2)}, | +| PERM | Presentation-style | {STYLE_ID_OF(P-Style1)}, | +| PERM | Content-architecture-class | {SFC\$PC\$FPC}, | +| PERM | Content-portions | {CONTENT_ID_OF(Character-content-portion)+} | + +-- if the attribute "content portions" is specified neither in the specific nor in the generic part then +-- the attribute "resource" shall be specified -- + +#### 7.3.3.7 BodyGeometric: ANY-LOGICAL { + +##### **GENERIC:** + +| | | | +|------|----------------------------|-------------------------------------------------------------------| +| REQ | Object-type | {'basic-logical-object'}, | +| REQ | Content-architecture-class | {SFPG}, | +| PERM | Resource | {ANY_VALUE}, | +| REQ | Application-comments | {REQ #constraint-name {"18"},<br>PERM #external-data {ANY_VALUE}} | + +##### **SPECIFIC:** + +| | | | +|------|----------------------------|-------------------------------------------------------------------| +| PERM | Object-type | {'basic-logical-object'}, | +| REQ | Object-class | {OBJECT_CLASS_ID_OF(BodyGeometric)}, | +| PERM | Content-architecture-class | {SFPG}, | +| PERM | Application-comments | {REQ #constraint-name {"18"},<br>PERM #external-data {ANY_VALUE}} | + +##### **SPECIFIC\_AND\_GENERIC:** + +| | | | +|------|--------------------|-----------------------------------------------------| +| PERM | Layout-style | {STYLE_ID_OF(L-Style5)}, | +| PERM | Presentation-style | {STYLE_ID_OF(P-Style4)}, | +| PERM | Content-portions | {CONTENT_ID_OF(Geometric-graphics-content-portion)} | + +-- if the attribute "content portions" is specified neither in the specific nor in the generic part then +-- the attribute "resource" shall be specified -- + +#### 7.3.3.8 BodyRaster: ANY-LOGICAL { + +##### **GENERIC:** + +| | | | +|------|----------------------------|-------------------------------------------------------------------| +| REQ | Object-type | {'basic-logical-object'}, | +| REQ | Content-architecture-class | {SFPR}, | +| PERM | Resource | {ANY_VALUE}, | +| REQ | Application-comments | {REQ #constraint-name {"17"},<br>PERM #external-data {ANY_VALUE}} | + +##### **SPECIFIC:** + +| | | | +|------|----------------------------|-------------------------------------------------------------------| +| PERM | Object-type | {'basic-logical-object'}, | +| REQ | Object-class | {OBJECT_CLASS_ID_OF(BodyRaster)}, | +| PERM | Content-architecture-class | {SFPR}, | +| PERM | Application-comments | {REQ #constraint-name {"17"},<br>PERM #external-data {ANY_VALUE}} | + +##### **SPECIFIC\_AND\_GENERIC:** + +| | | | +|------|--------------------|--------------------------------------------------| +| PERM | Layout-style | {STYLE_ID_OF(L-Style5)}, | +| PERM | Presentation-style | {STYLE_ID_OF(P-Style3)}, | +| PERM | Content-portions | {CONTENT_ID_OF(Raster-graphics-content-portion)} | + +-- if the attribute "content portions" is specified neither in the specific nor in the generic part then +-- the attribute "resource" shall be specified -- + +#### 7.3.3.9 Footnote: ANY-LOGICAL { + +##### **GENERIC:** + +| | | | +|------|----------------------------|--------------------------------------------------------------------------------| +| REQ | Object-type | {'composite-logical-object'}, | +| REQ | Generator-for-subordinates | {FootnoteGFS}, | +| PERM | Bindings | {PERM{REQ{\$INCFNOTENUMBER,<br>\$FNOTENUMBERSTRING}<br>\$FNOTESTRINGLITERAL}}, | + +| | | | +|-----|----------------------|------------------------------------------------------------------| +| REQ | Application-comments | {REQ #constraint-name {"8"},<br>PERM #external-data {ANY_VALUE}} | +|-----|----------------------|------------------------------------------------------------------| + +SPECIFIC: + +| | | | +|------|--------------|-------------------------------------------------------------| +| PERM | Object-type | {'composite-logical-object'}, | +| REQ | Object-class | {OBJECT_CLASS_ID_OF(Footnote)}, | +| REQ | Subordinates | {SUB_ID_OF(FootnoteReference),<br>SUB_ID_OF(FootnoteBody)}, | +| PERM | Bindings | {\$FNOTESTRINGLITERAL}, | +| PERM | Bindings | {\$FNOTESTRINGLITERAL}, | + +-- if bindings are not specified on the GENERIC then they shall be specified on the SPECIFIC -- + +| | | | +|------|----------------------|------------------------------------------------------------------| +| PERM | Application-comments | {REQ #constraint-name {"8"},<br>PERM #external-data {ANY_VALUE}} | +|------|----------------------|------------------------------------------------------------------| + +SPECIFIC\_AND\_GENERIC: + +| | | | +|------|--------------|-------------------------| +| PERM | Layout-style | {STYLE_ID_OF(L-Style7)} | +|------|--------------|-------------------------| + +#### 7.3.3.10 FootnoteReference: ANY-LOGICAL { + +GENERIC: + +| | | | +|-----|----------------------|-------------------------------------------------------------------| +| REQ | Object-type | {'basic-logical-object'}, | +| REQ | Content-generator | {\$FNOTENUMBER}, | +| REQ | Application-comments | {REQ #constraint-name {"10"},<br>PERM #external-data {ANY_VALUE}} | + +SPECIFIC: + +| | | | +|------|----------------------|-------------------------------------------------------------------| +| PERM | Object-type | {'basic-logical-object'}, | +| REQ | Object-class | {OBJECT_CLASS_ID_OF (FootnoteReference)}, | +| PERM | Application-comments | {REQ #constraint-name {"10"},<br>PERM #external-data {ANY_VALUE}} | + +SPECIFIC\_AND\_GENERIC: + +| | | | +|------|----------------------------|---------------------------| +| PERM | Layout-style | {STYLE_ID_OF(L-Style10)}, | +| PERM | Presentation-style | {STYLE_ID_OF(P-Style1)}, | +| PERM | Content-architecture-class | {\$FC \$PC \$FPC}} | + +#### 7.3.3.11 FootnoteBody: ANY-LOGICAL { + +GENERIC: + +| | | | +|------|----------------------------|--------------------------------------------------------------------| +| REQ | Object-type | {'composite-logical-object'}, | +| REQ | Generator-for-subordinates | {\$FootnoteBodyGFS}, | +| REQ | Application-comments | {REQ #constraint-name {"11"},<br>PERM #external-data {ANY_VALUE}}, | +| PERM | Layout-style | {STYLE_ID_OF (L-Style11)} | + +SPECIFIC: + +| | | | +|------|----------------------|--------------------------------------------------------------------| +| PERM | Object-type | {'composite-logical-object'}, | +| REQ | Object-class | {OBJECT_CLASS_ID_OF(FootnoteBody)}, | +| REQ | Subordinates | {SUB_ID_OF(FootnoteNumber),<br>SUB_ID_OF(FootnoteText)+}, | +| PERM | Application-comments | {REQ #constraint-name {"11"},<br>PERM #external-data {ANY_VALUE}}, | +| PERM | Layout-style | {STYLE_ID_OF (L-Style11)} | + +#### 7.3.3.12 FootnoteNumber: ANY-LOGICAL { + +GENERIC: + +| | | | +|-----|----------------------|-------------------------------------------------------------------| +| REQ | Object-type | {'basic-logical-object'}, | +| REQ | Content-generator | {\$FNOTENUMBER}, | +| REQ | Application-comments | {REQ #constraint-name {"9"},<br>PERM #external-data {ANY_VALUE}}, | +| REQ | Layout-style | {STYLE_ID_OF(L-Style9)} | + +SPECIFIC: + +| | | | +|------|----------------------|-------------------------------------------------------------------| +| PERM | Object-type | {'basic-logical-object'}, | +| REQ | Object-class | {OBJECT_CLASS_ID_OF(FootnoteNumber)}, | +| PERM | Application-comments | {REQ #constraint-name {"9"},<br>PERM #external-data {ANY_VALUE}}, | +| PERM | Layout-style | {STYLE_ID_OF(L-Style9)} | + +SPECIFIC\_AND\_GENERIC: + +| | | | +|------|----------------------------|--------------------------| +| PERM | Presentation-style | {STYLE_ID_OF(P-Style1)}, | +| PERM | Content-architecture-class | {SFC SPC SFPC}} | + +#### 7.3.3.13 FootnoteText: ANY-LOGICAL { + +##### GENERIC: + +| | | | +|-----|----------------------|--------------------------------------------------------------------| +| REQ | Object-type | {'basic-logical-object'}, | +| REQ | Application-comments | {REQ #constraint-name {"12"},<br>PERM #external-data {ANY_VALUE}}, | +| REQ | Layout-style | {STYLE_ID_OF(L-Style6)} | + +##### SPECIFIC: + +| | | | +|------|----------------------|--------------------------------------------------------------------| +| PERM | Object-type | {'basic-logical-object'}, | +| REQ | Object-class | {OBJECT_CLASS_ID_OF(FootnoteText)}, | +| REQ | Content-portions | {CONTENT_ID_OF(<br>Character-content-portion)+}, | +| PERM | Application-comments | {REQ #constraint-name {"12"},<br>PERM #external-data {ANY_VALUE}}, | +| PERM | Layout-style | {STYLE_ID_OF(L-Style6)} | + +##### SPECIFIC\_AND\_GENERIC: + +| | | | +|------|----------------------------|--------------------------| +| PERM | Presentation-style | {STYLE_ID_OF(P-Style1)}, | +| PERM | Content-architecture-class | {SFC SPC SFPC}} | + +#### 7.3.3.14 CommonContent { + +##### GENERIC: + +| | | | +|------|----------------------------|--------------------------------------------------------------------| +| REQ | Object-type | {'composite-logical-object'}, | +| REQ | Object-class-identifier | {ANY_VALUE}, | +| REQ | Generator-for-subordinates | {\$CommonContentGFS}, | +| REQ | Application-comments | {REQ #constraint-name {"19"},<br>PERM #external-data {ANY_VALUE}}, | +| PERM | User-readable-comments | {ANY_STRING}, | +| PERM | User-visible-name | {ANY_STRING}} | + +#### 7.3.3.15 CommonText { + +##### GENERIC: + +| | | | +|------|----------------------------|--------------------------------------------------------------------| +| REQ | Object-type | {'basic-logical-object'}, | +| REQ | Object-class-identifier | {ANY_VALUE}, | +| PERM | Content-portions | {CONTENT_ID_OF(Character-content-portion)+}, | +| PERM | Resource | {ANY_VALUE}, | +| PERM | Layout-style | {STYLE_ID_OF(L-Style3)}, | +| PERM | Presentation-style | {STYLE_ID_OF(P-Style2)}, | +| PERM | Content-architecture-class | {SFC SPC SFPC}, | +| REQ | Application-comments | {REQ #constraint-name {"20"},<br>PERM #external-data {ANY_VALUE}}, | +| PERM | User-readable-comments | {ANY_STRING}, | +| PERM | User-visible-name | {ANY_STRING}} | + +-- either the attribute "content portions" or "resource" shall be specified in the above constituent constraint -- + +#### 7.3.3.16 PageNumber { + +##### GENERIC: + +| | | | +|------|----------------------------|--------------------------------------------------------------------| +| REQ | Object-type | {'basic-logical-object'}, | +| REQ | Object-class-identifier | {ANY_VALUE}, | +| REQ | Content-generator | {SPGNUMBER}, | +| PERM | Layout-style | {STYLE_ID_OF(L-Style3)}, | +| PERM | Presentation-style | {STYLE_ID_OF(P-Style2)}, | +| PERM | Content-architecture-class | {SFC SPC SFPC}, | +| REQ | Application-comments | {REQ #constraint-name {"40"},<br>PERM #external-data {ANY_VALUE}}, | +| PERM | User-readable-comments | {ANY_STRING}, | +| PERM | User-visible-name | {ANY_STRING}} | + +#### 7.3.3.17 CommonGeometric { + +##### GENERIC: + +| | | | +|------|-------------------------|------------------------------------------------------| +| REQ | Object-type | {'basic-logical-object'}, | +| REQ | Object-class-identifier | {ANY_VALUE}, | +| PERM | Content-portions | {CONTENT_ID_OF(Geometric-graphics-content-portion)}, | + +| | | | +|------|----------------------------|--------------------------------------------------------------------| +| PERM | Resource | {ANY_VALUE}, | +| PERM | Layout-style | {STYLE_ID_OF(L-Style8)}, | +| PERM | Presentation-style | {STYLE_ID_OF(P-Style4)}, | +| REQ | Content-architecture-class | {\$FPG}, | +| REQ | Application-comments | {REQ #constraint-name {"22"},<br>PERM #external-data {ANY_VALUE}}, | +| PERM | User-readable-comments | {ANY_STRING}, | +| PERM | User-visible-name | {ANY_STRING}} | + +-- either the attribute "content portions" or "resource" shall be specified in the above constituent constraint -- + +#### 7.3.3.18 CommonRaster { + +##### GENERIC: + +| | | | +|------|----------------------------|--------------------------------------------------------------------| +| REQ | Object-type | {'basic-logical-object'}, | +| REQ | Object-class-identifier | {ANY_VALUE}, | +| PERM | Content-portions | {CONTENT_ID_OF(Raster-graphics-content-portion)}, | +| PERM | Resource | {ANY_VALUE}, | +| PERM | Layout-style | {STYLE_ID_OF(L-Style8)}, | +| PERM | Presentation-style | {STYLE_ID_OF(P-Style3)}, | +| REQ | Content-architecture-class | {\$FPR}, | +| REQ | Application-comments | {REQ #constraint-name {"21"},<br>PERM #external-data {ANY_VALUE}}, | +| PERM | User-readable-comments | {ANY_STRING}, | +| PERM | User-visible-name | {ANY_STRING}} | + +-- either the attribute "content portions" or "resource" shall be specified in the above constituent constraint -- + +## 7.4 Layout constituent constraints + +### 7.4.1 Macro definitions + +``` + +DEFINE(DocLayRootGFS, " +<construction-expr> ::= <construction-term> +|<construction-type>; + +<construction-term> ::= <construction-factor> +|OPT <construction-factor> +|REP <construction-factor> +|OPT REP <construction-factor>; + +<construction-type> ::= SEQ({<construction-term>}...) +|CHO({<construction-term>}...); + +<construction-factor> ::= OBJECT_CLASS_ID_OF(PageSet) +|<construction-type>; + +") + +DEFINE(PageSetGFS, " +<construction-expr> ::= <pageset-1> +|<pageset-2> +|<pageset-3> +|SEQ(<pageset-1><pageset-2>) +|SEQ(<pageset-1><pageset-3>); + +<pageset-1> ::= OBJECT_CLASS_ID_OF(Page) +|OPT OBJECT_CLASS_ID_OF(Page); + +<pageset-2> ::= REP OBJECT_CLASS_ID_OF(Page) +|OPT REP OBJECT_CLASS_ID_OF(Page); + +<pageset-3> ::= OPT REP SEQ(OBJECT_CLASS_ID_OF(RectoPage) +OPT OBJECT_CLASS_ID_OF(VersoPage)) +|OPT REP SEQ(OBJECT_CLASS_ID_OF(VersoPage) +OPT OBJECT_CLASS_ID_OF(RectoPage)) +|REP SEQ(OBJECT_CLASS_ID_OF(RectoPage) +OPT OBJECT_CLASS_ID_OF(VersoPage)) +|REP SEQ(OBJECT_CLASS_ID_OF(VersoPage) +OPT OBJECT_CLASS_ID_OF(RectoPage)); + +") + +DEFINE(PageGFS, " +<construction-expr> ::= SEQ(|<headerarea>|<bodyarea>|<footerarea>|) +|<bodyarea>; + +``` + +``` + +<headerarea> ::= OBJECT_CLASS_ID_OF(BasicHeader) + |OBJECT_CLASS_ID_OF(CompositeHeader); + +<bodyarea> ::= OBJECT_CLASS_ID_OF(BasicBody) + |OBJECT_CLASS_ID_OF(VariableCompositeBody); + +<footerarea> ::= OBJECT_CLASS_ID_OF(BasicFooter) + |OBJECT_CLASS_ID_OF(CompositeFooter); + + ") +DEFINE(VariableCompositeBodyGFS, " +<construction-expr> ::= <construction-term> + |<construction-type> + |SEQ(<construction-term>, <construction-footnote>) + |SEQ(<construction-type>, <construction-footnote>); + +<construction-term> ::= <construction-factor> + |OPT <construction-factor> + |REP <construction-factor> + |OPT REP <construction-factor>; + +<construction-type> ::= SEQ({<construction-term>}...) + |CHO({<construction-term>}...); + +<construction-factor> ::= OBJECT_CLASS_ID_OF(BasicFloat) + |OBJECT_CLASS_ID_OF(SnakingColumns) + |OBJECT_CLASS_ID_OF(SynchronizedColumns) + |<construction-type>; + +<construction-footnote> ::= OBJECT_CLASS_ID_OF(FootnoteArea) + |OPT OBJECT_CLASS_ID_OF(FootnoteArea); + + ") +DEFINE(SnakingColumnsGFS, " +<construction-expr> ::= SEQ({OBJECT_CLASS_ID_OF(ColumnVariable)}...) + |REP OBJECT_CLASS_ID_OF(ColumnVariable); + + ") +DEFINE(SynchronizedColumnsGFS, " +<construction-expr> ::= SEQ({OBJECT_CLASS_ID_OF(ColumnFixed)}...); + + ") +DEFINE(HeaderFooterGFS, " +<construction-expr> ::= <fixed-common-content-frames> + |<variable-common-content-frames>; + +<fixed-common-content-frames> ::= SEQ({OBJECT_CLASS_ID_OF(SourcedContentFixed) + |OBJECT_CLASS_ID_OF(ArrangedContentFixed)}...); + +<variable-common-content-frames> ::= SEQ({OBJECT_CLASS_ID_OF(SourcedContentVariable) + |OBJECT_CLASS_ID_OF(ArrangedContentVariable)}...); + + ") +DEFINE(INITIALISEPGNUM, " + REQ #binding-name{""PGnum""}, + REQ #binding-value{>=1} + + ") +DEFINE(PAGENUMBER, " + REQ #binding-name{""PGnum""}, + REQ #binding-value{<num-expr>::=INC(B_REF(PREC( + CURR-OBJ))(""PGnum""))}; + + ") +DEFINE(PDA-FPDA, "{'processable'|'formatted-processable'}") + +``` + +### 7.4.2 Factor constraints + +#### 7.4.2.1 FACTOR ANY-LAYOUT { + +##### GENERIC: + +| | | | +|-----|-------------------------|--------------| +| REQ | Object-type | {VIRTUAL}, | +| REQ | Object-class-identifier | {ANY_VALUE}, | + +| | | | +|-----|----------------------|-----------| +| REQ | Application-comments | {VIRTUAL} | +|-----|----------------------|-----------| + +SPECIFIC: + +| | | | +|--------|------------------------|--------------| +| PERM | Object-type | {VIRTUAL}, | +| REQ | Object-identifier | {ANY_VALUE}, | +| CASE | \$DAC OF { | | +| SFDA: | PERM      Object-class | {VIRTUAL} | +| SFPDA: | REQ      Object-class | {VIRTUAL} | +| | } | | +| REQ | Subordinates | {VIRTUAL}, | +| PERM | Application-comments | {VIRTUAL} | + +SPECIFIC\_AND\_GENERIC: + +| | | | +|------|------------------------|---------------| +| PERM | User-readable-comments | {ANY_STRING}, | +| PERM | User-visible-name | {ANY_STRING}} | + +#### 7.4.2.2 FACTOR ANY-PAGE: ANY-LAYOUT { + +GENERIC: + +| | | | +|------|----------------------------|----------------| +| REQ | Object-type | {'page'}, | +| CASE | \$DAC OF { | | +| | \$PDA-FPDA: | | +| PERM | Bindings | {SPAGENUMBER}, | +| REQ | Generator-for-subordinates | {\$PageGFS} | +| | } | | + +SPECIFIC: + +| | | | +|------|--------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| PERM | Object-type | {'page'}, | +| REQ | Subordinates | {SUB_ID_OF(BasicHeader),<br>SUB_ID_OF(CompositeHeader),<br>SUB_ID_OF(BasicBody),<br>SUB_ID_OF(VariableCompositeBody),<br>SUB_ID_OF(BasicFooter),<br>SUB_ID_OF(CompositeFooter)} | + +SPECIFIC\_AND\_GENERIC: + +| | | | +|------|---------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| PERM | Dimensions | {REQ #horizontal-dimension<br>{REQ #fixed-dimension {<=14030}},<br>REQ #vertical-dimension<br>{REQ #fixed-dimension {<=19840}}<br>-- up to ISO A3 portrait --<br> REQ #horizontal-dimension<br>{REQ #fixed-dimension {<=19840}},<br>REQ #vertical-dimension<br>{REQ #fixed-dimension {<=14030}}<br>-- up to ISO A3 landscape --<br> REQ #horizontal-dimension<br>{REQ #fixed-dimension {<=13200}},<br>REQ #vertical-dimension<br>{REQ #fixed-dimension {<=20400}}<br>-- up to ANSI-B portrait --<br> REQ #horizontal-dimension<br>{REQ #fixed-dimension {<=20400}},<br>REQ #vertical-dimension<br>REQ #fixed-dimension {<=13200}}<br>-- up to ANSI-B landscape --}, | +| PERM | Page-position | {ANY_VALUE}} | + +#### 7.4.2.3 FACTOR ANY-FRAME-FIXED: ANY-LAYOUT { + +GENERIC: + +| | | | +|-----|-------------|-----------| +| REQ | Object-type | {'frame'} | +|-----|-------------|-----------| + +SPECIFIC: + +| | | | +|------|-------------|-----------| +| PERM | Object-type | {'frame'} | +|------|-------------|-----------| + +SPECIFIC\_AND\_GENERIC: + +| | | | +|------|------------|---------------------------------------------------------------------------------------------------------| +| PERM | Position | {REQ #fixed-position<br>{REQ #horizontal-position {ANY_VALUE},<br>REQ #vertical-position {ANY_VALUE}}}, | +| PERM | Dimensions | {REQ #horizontal-dimension | + +| | | | | | +|------|--------|--|--|--------------------------------------| +| | | | | {REQ #fixed-dimension {ANY_VALUE}}, | +| | | | | REQ #vertical-dimension | +| | | | | {REQ #fixed-dimension {ANY_VALUE}}}, | +| PERM | Border | | | {ANY_VALUE}} | + +#### 7.4.2.4 FACTOR ANY-FRAME-VARIABLE: ANY-LAYOUT { + +##### GENERIC: + +| | | | | | +|-----|-------------|--|--|-----------| +| REQ | Object-type | | | {'frame'} | +|-----|-------------|--|--|-----------| + +##### SPECIFIC: + +| | | | | | +|------|-------------|-----|------------|----------------------------------------| +| PERM | Object-type | | | {'frame'}, | +| CASE | SDAC OF { | | | | +| | SFPDA: | REQ | Position | {REQ #fixed-position | +| | | | | {REQ #horizontal-position {ANY_VALUE}, | +| | | | | REQ #vertical-position {ANY_VALUE}}}, | +| | | REQ | Dimensions | {REQ #horizontal-dimension | +| | | | | {REQ #fixed-dimension {ANY_VALUE}}, | +| | | | | REQ #vertical-dimension | +| | | | | {REQ #fixed-dimension {ANY_VALUE}}} | +| | } | | | | + +##### SPECIFIC\_AND\_GENERIC: + +| | | | | | +|------|-----------|------|------------|----------------------------------------| +| CASE | SDAC OF { | | | | +| | SFDA: | PERM | Position | {REQ #fixed-position | +| | | | | {REQ #horizontal-position {ANY_VALUE}, | +| | | | | REQ #vertical-position {ANY_VALUE}}}, | +| | | PERM | Dimensions | {REQ #horizontal-dimension | +| | | | | {REQ #fixed-dimension {ANY_VALUE}}, | +| | | | | REQ #vertical-dimension | +| | | | | {REQ #fixed-dimension {ANY_VALUE}}} | +| | } | | | | +| PERM | Border | | | {ANY_VALUE} | +| | } | | | | + +#### 7.4.2.5 FACTOR BLOCK { + +##### SPECIFIC: + +| | | | | | +|------|----------------------------------------|--|--|----------------------------------------| +| REQ | Object-type | | | {'block'}, | +| REQ | Object-identifier | | | {ANY_VALUE}, | +| PERM | Content-architecture-class | | | {SFC SFPC SFPR SFPG}, | +| PERM | Presentation-attributes { | | | | +| | PERM #character-attributes { | | | | +| | PERM #alignment | | | {ANY_VALUE}, | +| | PERM #character-fonts | | | {ANY_VALUE}, | +| | PERM #character-spacing | | | {ANY_VALUE}, | +| | PERM #character-orientation | | | {'0-degrees' | +| | | | | '90-degrees'}, | +| | PERM #character-path | | | {'0-degrees' | +| | | | | '90-degrees' | +| | | | | '180-degrees' | +| | | | | '270-degrees'}, | +| | PERM #code-extension-announcers | | | {SCDEXTEN}, | +| | PERM #first-line-offset | | | {ANY_VALUE}, | +| | PERM #graphic-character-sets | | | {SPERMIT-GRCHAR}, | +| | PERM #graphic-character-sub-repertoire | | | {ANY_VALUE}, | +| | PERM #graphic-rendition | | | {SGRAPHICRENDITIONS}, | +| | PERM #itemization | | | {ANY_VALUE}, | +| | PERM #kerning-offset | | | {ANY_VALUE}, | +| | PERM #line-layout-table | | | {ANY_VALUE}, | +| | PERM #line-progression | | | {'90-degrees' '270-degrees'}, | +| | PERM #line-spacing | | | {ANY_VALUE}, | +| | PERM #initial-offset | | | {ANY_VALUE}}}, | +| PERM | User-readable-comments | | | {ANY_STRING}, | +| PERM | User-visible-name | | | {ANY_STRING}, | +| PERM | Position | | | {REQ #fixed-position | +| | | | | {REQ #horizontal-position {ANY_VALUE}, | +| | | | | REQ #vertical-position {ANY_VALUE}}}, | +| PERM | Dimensions | | | {REQ #horizontal-dimension | +| | | | | {REQ #fixed-dimension {ANY_VALUE}}}, | + +REQ #vertical-dimension + {REQ #fixed-dimension {ANY\_VALUE}}} + +### 7.4.3 Constituent constraints + +#### 7.4.3.1 DocumentLayoutRoot: ANY-LAYOUT { + +##### GENERIC: + +REQ Object-type {'document-layout-root'}, + CASE \$DAC OF { +   \$PDA-FPDA: + PERM Bindings {INITIALISEPGNUM}, + REQ Generator-for-subordinates {\$DocLayRootGFS} + }, + REQ Application-comments {REQ #constraint-name {"0"}, + PERM #external-data {ANY\_VALUE}} + +##### SPECIFIC: + +PERM Object-type {'document-layout-root'}, + CASE \$DAC OF { +   \$FDA: PERM Object-class {OBJECT\_CLASS\_ID\_OF(DocumentLayoutRoot)} +   \$FPDA: REQ Object-class {OBJECT\_CLASS\_ID\_OF(DocumentLayoutRoot)} + }, + REQ Subordinates {SUB\_ID\_OF(PageSet)+}, + PERM Application-comments {REQ #constraint-name {"0"}, + PERM #external-data {ANY\_VALUE}} + +#### 7.4.3.2 PageSet: ANY-LAYOUT { + +##### GENERIC: + +REQ Object-type {'page-set'}, + CASE \$DAC OF { +   \$PDA-FPDA: + PERM Bindings {INITIALISEPGNUM}, + REQ Generator-for-subordinates {\$PageSetGFS} + }, + REQ Application-comments {REQ #constraint-name {"1"}, + PERM #external-data {ANY\_VALUE}} + +##### SPECIFIC: + +PERM Object-type {'page-set'}, + CASE \$DAC OF { +   \$FDA: PERM Object-class {OBJECT\_CLASS\_ID\_OF(PageSet)} +   \$FPDA: REQ Object-class {OBJECT\_CLASS\_ID\_OF(PageSet)} + }, + REQ Subordinates {SUB\_ID\_OF(Page)+, + SUB\_ID\_OF(RectoPage)+, + SUB\_ID\_OF(VersoPage)+}, + PERM Application-comments {REQ #constraint-name {"1"}, + PERM #external-data {ANY\_VALUE}} + +#### 7.4.3.3 Page: ANY-PAGE { + +##### GENERIC: + +REQ Application-comments {REQ #constraint-name {"2"}, + PERM #external-data {ANY\_VALUE}} + +##### SPECIFIC: + +CASE \$DAC OF { +   \$FDA: PERM Object-class {OBJECT\_CLASS\_ID\_OF(Page)} +   \$FPDA: REQ Object-class {OBJECT\_CLASS\_ID\_OF(Page)} + }, + PERM Application-comments {REQ #constraint-name {"2"}, + PERM #external-data {ANY\_VALUE}} + +##### SPECIFIC\_AND\_GENERIC: + +PERM Medium-type {PERM #nominal-page-size {\$NominalPageSizes}, + PERM #side-of-sheet {ANY\_VALUE}} + +#### 7.4.3.4 RectoPage: ANY-PAGE { + +##### GENERIC: + +| | | | +|-----------|--------------------------------------------------------------------------|------------------------------------------------------------------------------------------------| +| REQ | Application-comments | {REQ #constraint-name {"3"},<br>PERM #external-data {ANY_VALUE}}, | +| REQ | Medium-type | {PERM #nominal-page-size {\$NominalPageSizes},<br>REQ #side-of-sheet {'recto' 'unspecified'}} | +| SPECIFIC: | | | +| CASE | \$DAC OF {<br>\$FDA: PERM Object-class<br>\$FPDA: REQ Object-class<br>}, | {OBJECT_CLASS_ID_OF(RectoPage)}<br>{OBJECT_CLASS_ID_OF(RectoPage)} | +| PERM | Application-comments | {REQ #constraint-name {"3"},<br>PERM #external-data {ANY_VALUE}}, | +| PERM | Medium-type | {PERM #nominal-page-size {\$NominalPageSizes},<br>PERM #side-of-sheet {'recto' 'unspecified'}} | + +#### 7.4.3.5 VersoPage: ANY-PAGE { + +| | | | +|-----------|--------------------------------------------------------------------------|------------------------------------------------------------------------------------------------| +| GENERIC: | | | +| REQ | Application-comments | {REQ #constraint-name {"4"},<br>PERM #external-data {ANY_VALUE}}, | +| REQ | Medium-type | {PERM #nominal-page-size {\$NominalPageSizes},<br>REQ #side-of-sheet {'verso' 'unspecified'}} | +| SPECIFIC: | | | +| CASE | \$DAC OF {<br>\$FDA: PERM Object-class<br>\$FPDA: REQ Object-class<br>}, | {OBJECT_CLASS_ID_OF(VersoPage)}<br>{OBJECT_CLASS_ID_OF(VersoPage)} | +| PERM | Application-comments | {REQ #constraint-name {"4"},<br>PERM #external-data {ANY_VALUE}}, | +| PERM | Medium-type | {PERM #nominal-page-size {\$NominalPageSizes},<br>PERM #side-of-sheet {'verso' 'unspecified'}} | + +#### 7.4.3.6 BasicBody: ANY-FRAME-FIXED { + +| | | | +|-----------|--------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------| +| GENERIC: | | | +| PERM | Layout-path | {'270-degrees' -- page layout A --<br> '0-degrees' -- page layout B --<br> '180-degrees' -- page layouts C and D --}, | +| REQ | Application-comments | {REQ #constraint-name {"28"},<br>PERM #external-data {ANY_VALUE}} | +| SPECIFIC: | | | +| CASE | \$DAC OF {<br>\$FDA: PERM Object-class<br>\$FPDA: REQ Object-class<br>}, | {OBJECT_CLASS_ID_OF(BasicBody)}<br>{OBJECT_CLASS_ID_OF(BasicBody)} | +| REQ | Subordinates | {SUB_ID_OF(SpecificBlock)+}, | +| PERM | Application-comments | {REQ #constraint-name {"28"},<br>PERM #external-data {ANY_VALUE}} | + +#### 7.4.3.7 VariableCompositeBody: ANY-FRAME-FIXED { + +| | | | +|-----------|---------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------| +| GENERIC: | | | +| CASE | \$DAC OF {<br>\$PDA-FPDA:<br>REQ Generator-for-subordinates<br>PERM Layout-path<br>}, | {SVariableCompositeBodyGFS},<br>{'270-degrees' -- page layout A --<br> '0-degrees' -- page layout B --<br> '180-degrees' -- page layouts C and D --} | +| REQ | Application-comments | {REQ #constraint-name {"7"},<br>PERM #external-data {ANY_VALUE}} | +| SPECIFIC: | | | +| CASE | \$DAC OF {<br>\$FDA: PERM Object-class<br>\$FPDA: REQ Object-class<br>}, | {OBJECT_CLASS_ID_OF(VariableCompositeBody)}<br>{OBJECT_CLASS_ID_OF(VariableCompositeBody)} | +| REQ | Subordinates | {SUB_ID_OF(BasicFloat)+}, | + +| | | | +|------|----------------------|----------------------------------| +| | | SUB_ID_OF(SnakingColumns)+, | +| | | SUB_ID_OF(SynchronizedColumns)+, | +| | | SUB_ID_OF(FootnoteArea)}, | +| PERM | Application-comments | {REQ #constraint-name {"7"}, | +| | | PERM #external-data {ANY_VALUE}} | + +#### 7.4.3.8 BasicFloat: ANY-FRAME-VARIABLE { + +##### GENERIC: + +| | | | +|------|---------------------------------------------------------|--------------------------------------| +| CASE | \$DAC OF { | | +| | \$PDA-FPDA: | | +| | REQ Position | {REQ #variable-position { | +| | | PERM #offset {ANY_VALUE}, | +| | | PERM #separation {ANY_VALUE}, | +| | | PERM #alignment {ANY_VALUE}, | +| | | PERM #fill-order {'normal-order'}}}, | +| | PERM Permitted-categories {ANY_STRING}, | | +| | CASE SUPERIOR (VariableCompositeBody(Layout-path)) OF { | | +| | {'270-degrees': -- page layout A -- | | +| | REQ Dimensions | {REQ #horizontal-dimension | +| | | {REQ #fixed-dimension {ANY_VALUE} | +| | | REQ #maximum-size {'applies'}}, | +| | | REQ #vertical-dimension | +| | | {REQ #rule-b {ANY_VALUE}}}, | +| | PERM Layout-path | {'270-degrees'} | +| | {'0-degrees': -- page layout B -- | | +| | REQ Dimensions | {REQ #horizontal-dimension | +| | | {REQ #rule-b {ANY_VALUE}}, | +| | | REQ #vertical-dimension | +| | | {REQ #fixed-dimension {ANY_VALUE} | +| | | REQ #maximum-size {'applies'}}}, | +| | REQ Layout-path | {'0-degrees'} | +| | {'180-degrees': -- page layouts C and D -- | | +| | REQ Dimensions | {REQ #horizontal-dimension | +| | | {REQ #rule-b {ANY_VALUE}}, | +| | | REQ #vertical-dimension | +| | | {REQ #fixed-dimension {ANY_VALUE} | +| | | REQ #maximum-size {'applies'}}}, | +| | REQ Layout-path | {'180-degrees'} | +| | } | | +| | } | | +| | } | | +| REQ | Application-comments | {REQ #constraint-name {"12"}, | +| | | PERM #external-data {ANY_VALUE}} | + +##### SPECIFIC: + +| | | | +|------|--------------------------|----------------------------------| +| CASE | \$DAC OF { | | +| | \$FDA: PERM Object-class | {OBJECT_CLASS_ID_OF(BasicFloat)} | +| | \$FPDA: REQ Object-class | {OBJECT_CLASS_ID_OF(BasicFloat)} | +| | } | | +| REQ | Subordinates | {SUB_ID_OF(SpecificBlock)+}, | +| PERM | Application-comments | {REQ #constraint-name {"12"}, | +| | | PERM #external-data {ANY_VALUE}} | + +#### 7.4.3.9 SynchronizedColumns: ANY-FRAME-VARIABLE { + +##### GENERIC: + +| | | | +|------|---------------------------------------------------------|--------------------------------------| +| CASE | \$DAC OF { | | +| | \$PDA-FPDA: | | +| | REQ Generator-for-subordinates | {{SynchronizedColumnsGFS}, | +| | REQ Position | {REQ #variable-position { | +| | | PERM #offset {ANY_VALUE}, | +| | | PERM #separation {ANY_VALUE}, | +| | | PERM #alignment {ANY_VALUE}, | +| | | PERM #fill-order {'normal-order'}}}, | +| | CASE SUPERIOR (VariableCompositeBody(Layout-path)) OF { | | +| | {'270-degrees': -- page layout A -- | | +| | REQ Dimensions | {REQ #horizontal-dimension | +| | | {REQ #fixed-dimension {ANY_VALUE} | +| | | REQ #maximum-size {'applies'}}, | + +``` + + REQ #vertical-dimension + {REQ #rule-b {ANY_VALUE}}}, + PERM Layout-path {'270-degrees'} +{'0-degrees'}:-- page layout B -- + REQ Dimensions {REQ #horizontal-dimension + {REQ #rule-b {ANY_VALUE}}, + REQ #vertical-dimension + {REQ #fixed-dimension {ANY_VALUE} + |REQ #maximum-size {'applies'}}}, + + REQ Layout-path {'0-degrees'} +{'180-degrees'}:-- page layouts C and D -- + REQ Dimensions {REQ #horizontal-dimension + {REQ #rule-b {ANY_VALUE}}, + REQ #vertical-dimension + {REQ #fixed-dimension {ANY_VALUE} + |REQ #maximum-size {'applies'}}}, + + REQ Layout-path {'180-degrees'} +}, +}, +REQ Application-comments {REQ #constraint-name {"11"}, + PERM #external-data {ANY_VALUE}} + +SPECIFIC: +CASE $DAC OF { + $FDA: PERM Object-class {OBJECT_CLASS_ID_OF(SynchronizedColumns)} + $FPDA: REQ Object-class {OBJECT_CLASS_ID_OF(SynchronizedColumns)} + }, +REQ Subordinates {SUB_ID_OF(ColumnFixed)+}, +PERM Application-comments {REQ #constraint-name {"11"}, + PERM #external-data {ANY_VALUE}} + +``` + +#### 7.4.3.10 SnakingColumns: ANY-FRAME-VARIABLE { + +##### GENERIC: + +``` + +CASE $DAC OF { + $PDA-FPDA: + REQ Generator-for-subordinates {$SnakingColumnsGFS}, + REQ Position {REQ #variable-position { + PERM #offset {ANY_VALUE}, + PERM #separation {ANY_VALUE}, + PERM #alignment {ANY_VALUE}, + PERM #fill-order {'normal-order'}}}, + + PERM Balance {ANY_VALUE}, + CASE SUPERIOR (VariableCompositeBody(Layout-path)) OF { + {'270-degrees'}:-- page layout A -- + REQ Dimensions {REQ #horizontal-dimension + {REQ #fixed-dimension {ANY_VALUE} + |REQ #maximum-size {'applies'}}}, + REQ #vertical-dimension + {REQ #rule-b {ANY_VALUE}}}, + + REQ Layout-path {'0-degrees'|'180-degrees'} +{'0-degrees'}:-- page layout B -- + REQ Dimensions {REQ #horizontal-dimension + {REQ #rule-b {ANY_VALUE}}, + REQ #vertical-dimension + {REQ #fixed-dimension {ANY_VALUE} + |REQ #maximum-size {'applies'}}}, + + PERM Layout-path {'90-degrees'|'270-degrees'} +{'180-degrees'}:-- page layouts C and D -- + REQ Dimensions {REQ #horizontal-dimension + {REQ #rule-b {ANY_VALUE}}, + REQ #vertical-dimension + {REQ #fixed-dimension {ANY_VALUE} + |REQ #maximum-size {'applies'}}}, + + PERM Layout-path {'270-degrees'} + }, + }, +REQ Application-comments {REQ #constraint-name {"10"}, + PERM #external-data {ANY_VALUE}} + +``` + +##### **SPECIFIC:** + +| | | | +|------|--------------------------|-------------------------------------------------------------------| +| CASE | SDAC OF { | | +| | \$FDA: PERM Object-class | {OBJECT_CLASS_ID_OF(SnakingColumns)} | +| | \$FPDA: REQ Object-class | {OBJECT_CLASS_ID_OF(SnakingColumns)} | +| | } | | +| REQ | Subordinates | {SUB_ID_OF(ColumnVariable)+}, | +| PERM | Application-comments | {REQ #constraint-name {"10"},<br>PERM #external-data {ANY_VALUE}} | + +#### **7.4.3.11 ColumnVariable: ANY-FRAME-VARIABLE {** + +##### **GENERIC:** + +| | | | +|------|---------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------| +| CASE | SDAC OF { | | +| | \$PDA-FPDA: | | +| | PERM Permitted-categories | {ANY_STRING}, | +| | REQ Position | {REQ #variable-position {<br>PERM #offset {ANY_VALUE},<br>PERM #separation {ANY_VALUE},<br>PERM #alignment {ANY_VALUE},<br>PERM #fill-order {'normal-order'}}}, | +| | CASE SUPERIOR (VariableCompositeBody(Layout-path)) OF { | | +| | {'270-degrees'}: -- page layout A -- | | +| | REQ Dimensions | {REQ #horizontal-dimension<br>{REQ #fixed-dimension {ANY_VALUE}},<br>REQ #vertical-dimension<br>{REQ #rule-b {ANY_VALUE}<br> REQ #maximum-size {'applies'}}}, | +| | PERM Layout-path | {'270 degrees'} | +| | {'0-degrees'}: -- page layout B -- | | +| | REQ Dimensions | {REQ #horizontal-dimension<br>{REQ #rule-b {ANY_VALUE}<br> REQ #maximum-size {'applies'}},<br>REQ #vertical-dimension<br>{REQ #fixed-dimension {ANY_VALUE}}}, | +| | REQ Layout-path | {'0-degrees'} | +| | {'180-degrees'}: -- page layouts C and D -- | | +| | REQ Dimensions | {REQ #horizontal-dimension<br>{REQ #rule-b {ANY_VALUE}<br> REQ #maximum-size {'applies'}},<br>REQ #vertical-dimension<br>{REQ #fixed-dimension {ANY_VALUE}}}, | +| | REQ Layout-path | {'180-degrees'} | +| | } | | +| REQ | Application-comments | {REQ #constraint-name {"9"},<br>PERM #external-data {ANY_VALUE}} | + +##### **SPECIFIC:** + +| | | | +|------|--------------------------|------------------------------------------------------------------| +| CASE | SDAC OF { | | +| | \$FDA: PERM Object-class | {OBJECT_CLASS_ID_OF(ColumnVariable)} | +| | \$FPDA: REQ Object-class | {OBJECT_CLASS_ID_OF(ColumnVariable)} | +| | } | | +| REQ | Subordinates | {SUB_ID_OF(SpecificBlock)+}, | +| PERM | Application-comments | {REQ #constraint-name {"9"},<br>PERM #external-data {ANY_VALUE}} | + +#### **7.4.3.12 ColumnFixed: ANY-FRAME-VARIABLE {** + +##### **GENERIC:** + +| | | | +|------|---------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------| +| CASE | SDAC OF { | | +| | \$PDA-FPDA: | | +| | REQ Permitted-categories | {ANY_STRING}, | +| | REQ Position | {REQ #fixed-position<br>{REQ #horizontal-position {ANY_VALUE},<br>REQ #vertical-position {ANY_VALUE}}}, | +| | CASE SUPERIOR (VariableCompositeBody(Layout-path)) OF { | | +| | {'270-degrees'}: -- page layout A -- | | +| | REQ Dimensions | {REQ #horizontal-dimension<br>{REQ #fixed-dimension {ANY_VALUE}<br> REQ #maximum-size {'applies'}},<br>REQ #vertical-dimension | + +{REQ #rule-b {ANY\_VALUE} +|REQ #maximum-size {'applies'}}, + +PERM Layout-path {'270-degrees'} + +{'0-degrees'}: -- page layout B -- + +REQ Dimensions + +{REQ #horizontal-dimension +{REQ #rule-b {ANY\_VALUE} +|REQ #maximum-size {'applies'}}, +REQ #vertical-dimension +{REQ #fixed-dimension {ANY\_VALUE} +|REQ #maximum-size {'applies'}}}, + +REQ Layout-path {'0-degrees'} + +{'180-degrees'}: -- page layouts C and D -- + +REQ Dimensions + +{REQ #horizontal-dimension +{REQ #maximum-size {'applies'}}, +REQ #vertical-dimension +{REQ #fixed-dimension {ANY\_VALUE} +|REQ #maximum-size {'applies'}}}, + +REQ Layout-path {'180-degrees'} + +} +}, + +REQ Application-comments + +{REQ #constraint-name {"8"}, +PERM #external-data {ANY\_VALUE}} + +SPECIFIC: +CASE \$DAC OF { +    \$FDA: PERM Object-class {OBJECT\_CLASS\_ID\_OF(ColumnFixed)} +    \$SFPDA: REQ Object-class {OBJECT\_CLASS\_ID\_OF(ColumnFixed)} +}, + +REQ Subordinates {SUB\_ID\_OF(SpecificBlock)+}, +PERM Application-comments {REQ #constraint-name {"8"}, +    PERM #external-data {ANY\_VALUE}} + +#### 7.4.3.13 FootnoteArea: ANY-FRAME-VARIABLE { + +##### GENERIC: + +CASE \$DAC OF { +    SPDA-FPDA: +        REQ Position {REQ #variable-position { +            PERM #offset {ANY\_VALUE}, +            PERM #separation {ANY\_VALUE}, +            PERM #alignment {ANY\_VALUE}, +            REQ #fill-order {'reverse-order'}}}, + +REQ Permitted-categories {"Footnote"}, + +CASE SUPERIOR (VariableCompositeBody(Layout-path)) OF { +{'270-degrees'}: -- page layout A -- +    REQ Dimensions {REQ #horizontal-dimension +        {REQ #fixed-dimension {ANY\_VALUE} +        |REQ #maximum-size {'applies'}}, +        REQ #vertical-dimension +        {REQ #rule-b {ANY\_VALUE}}}, + +PERM Layout-path {'270-degrees'} + +{'0-degrees'}: -- page layout B -- +    REQ Dimensions {REQ #horizontal-dimension +        {REQ #rule-b {ANY\_VALUE}}, +        REQ #vertical-dimension +        {REQ #fixed-dimension {ANY\_VALUE} +        |REQ #maximum-size {'applies'}}}, + +REQ Layout-path {'0-degrees'} + +{'180-degrees'}: -- page layouts C and D -- +    REQ Dimensions {REQ #horizontal-dimension +        {REQ #rule-b {ANY\_VALUE}}, +        REQ #vertical-dimension +        {REQ #fixed-dimension {ANY\_VALUE} +        |REQ #maximum-size {'applies'}}}, + +REQ Layout-path {'180-degrees'} +    }, +}, +REQ Application-comments {REQ #constraint-name {"15"}, +    PERM #external-data {ANY\_VALUE}} + +##### **SPECIFIC:** + +| | | +|------|------------------------------------------------------------------------------------------------------------------------------------------------| +| CASE | \$DAC OF {<br>\$FDA: PERM Object-class {OBJECT_CLASS_ID_OF(FootnoteArea)}<br>\$FPDA: REQ Object-class {OBJECT_CLASS_ID_OF(FootnoteArea)}<br>}, | +| REQ | Subordinates {SUB_ID_OF(SpecificBlock)+}, | +| PERM | Application-comments {REQ #constraint-name {"15"},<br>PERM #external-data {ANY_VALUE}} | + +#### **7.4.3.14 BasicHeader: ANY-FRAME-FIXED {** + +##### **GENERIC:** + +| | | +|------|---------------------------------------------------------------------------------------------| +| CASE | \$DAC OF{<br>\$PDA-FPDA: | +| REQ | Logical-source {OBJECT_CLASS_ID_OF(CommonContent)}}, | +| PERM | Layout-path {'270-degrees' -- page layouts A,B,C --<br> '180-degrees' -- page layout D --}, | +| REQ | Application-comments {REQ #constraint-name {"27"},<br>PERM #external-data {ANY_VALUE}} | + +##### **SPECIFIC:** + +| | | +|------|----------------------------------------------------------------------------------------------------------------------------------------------| +| CASE | \$DAC OF {<br>\$FDA: PERM Object-class {OBJECT_CLASS_ID_OF(BasicHeader)}<br>\$FPDA: REQ Object-class {OBJECT_CLASS_ID_OF(BasicHeader)}<br>}, | +| REQ | Subordinates {SUB_ID_OF(SpecificBlock)+}, | +| PERM | Application-comments {REQ #constraint-name {"27"},<br>PERM #external-data {ANY_VALUE}} | + +#### **7.4.3.15 BasicFooter: ANY-FRAME-FIXED {** + +##### **GENERIC:** + +| | | +|------|---------------------------------------------------------------------------------------------| +| CASE | \$DAC OF{<br>\$PDA-FPDA: | +| REQ | Logical-source {OBJECT_CLASS_ID_OF(CommonContent)}}, | +| PERM | Layout-path {'270-degrees' -- page layouts A,B,C --<br> '180-degrees' -- page layout D --}, | +| REQ | Application-comments {REQ #constraint-name {"33"},<br>PERM #external-data {ANY_VALUE}} | + +##### **SPECIFIC:** + +| | | +|------|----------------------------------------------------------------------------------------------------------------------------------------------| +| CASE | \$DAC OF {<br>\$FDA: PERM Object-class {OBJECT_CLASS_ID_OF(BasicFooter)}<br>\$FPDA: REQ Object-class {OBJECT_CLASS_ID_OF(BasicFooter)}<br>}, | +| REQ | Subordinates {SUB_ID_OF(SpecificBlock)+}, | +| PERM | Application-comments {REQ #constraint-name {"33"},<br>PERM #external-data {ANY_VALUE}} | + +#### **7.4.3.16 CompositeHeader: ANY-FRAME-FIXED {** + +##### **GENERIC:** + +| | | +|------|---------------------------------------------------------------------------------------------| +| CASE | \$DAC OF {<br>\$PDA-FPDA: | +| REQ | Generator-for-subordinates {\$HeaderFooterGFS}<br>}, | +| PERM | Layout-path {'270-degrees' -- page layouts A,B,C --<br> '180-degrees' -- page layout D --}, | +| REQ | Application-comments {REQ #constraint-name {"5"},<br>PERM #external-data {ANY_VALUE}} | + +##### **SPECIFIC:** + +| | | +|------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| CASE | \$DAC OF {<br>\$FDA: PERM Object-class {OBJECT_CLASS_ID_OF(CompositeHeader)}<br>\$FPDA: REQ Object-class {OBJECT_CLASS_ID_OF(CompositeHeader)}<br>}, | +| REQ | Subordinates {SUB_ID_OF(SourcedContentFixed)+,<br>SUB_ID_OF(ArrangedContentFixed)+,<br>SUB_ID_OF(SourcedContentVariable)+,<br>SUB_ID_OF(ArrangedContentVariable)+}, | + +| | | | +|------|----------------------|------------------------------------------------------------------| +| PERM | Application-comments | {REQ #constraint-name {"5"},<br>PERM #external-data {ANY_VALUE}} | +|------|----------------------|------------------------------------------------------------------| + +#### 7.4.3.17 CompositeFooter: ANY-FRAME-FIXED { + +##### GENERIC: + +| | | | +|------|----------------------------|---------------------------------------------------------------------------------| +| CASE | \$DAC OF {<br>\$PDA-FPDA: | | +| REQ | Generator-for-subordinates | {\$HeaderFooterGFS} | +| | }, | | +| PERM | Layout-path | {'270-degrees' -- page layouts A,B,C --<br> '180-degrees' -- page layout D --}, | +| REQ | Application-comments | {REQ #constraint-name {"32"},<br>PERM #external-data {ANY_VALUE}} | + +##### SPECIFIC: + +| | | | +|------|--------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------| +| CASE | \$DAC OF {<br>\$FDA: PERM Object-class<br>\$FPDA: REQ Object-class<br>}, | <br>{OBJECT_CLASS_ID_OF(CompositeFooter)}<br>{OBJECT_CLASS_ID_OF(CompositeFooter)} | +| REQ | Subordinates | {SUB_ID_OF(SourcedContentFixed)+,<br>SUB_ID_OF(ArrangedContentFixed)+,<br>SUB_ID_OF(SourcedContentVariable)+,<br>SUB_ID_OF(ArrangedContentVariable)+}, | +| PERM | Application-comments | {REQ #constraint-name {"32"},<br>PERM #external-data {ANY_VALUE}} | + +#### 7.4.3.18 SourcedContentVariable: ANY-FRAME-VARIABLE { + +##### GENERIC: + +| | | | +|------|-----------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| CASE | \$DAC OF {<br>\$PDA-FPDA: | | +| | REQ Logical-source | {OBJECT_CLASS_ID_OF(CommonContent)}, | +| | REQ Position | {REQ #variable-position {<br>PERM #offset {ANY_VALUE},<br>PERM #separation {ANY_VALUE},<br>PERM #alignment {ANY_VALUE},<br>PERM #fill-order {'normal-order'}}}, | +| | CASE SUPERIOR (CompositeHeader CompositeFooter<br>(Layout-path)) OF { | | +| | {'270-degrees'}: | | +| | REQ Dimensions | {REQ #horizontal-dimension<br>{REQ #fixed-dimension {ANY_VALUE}<br> REQ #maximum-size {'applies'}},<br>REQ #vertical-dimension<br>{REQ #fixed-dimension {ANY_VALUE}<br> REQ #rule-b {ANY_VALUE}}}, | +| | PERM Layout-path | {'270-degrees'} | +| | {'180-degrees'}: | | +| | REQ Dimensions | {REQ #horizontal-dimension<br>{REQ #fixed-dimension {ANY_VALUE}<br> REQ #rule-b {ANY_VALUE}},<br>REQ #vertical-dimension<br>{REQ #fixed-dimension {ANY_VALUE}<br> REQ #maximum-size {'applies'}}}, | +| | REQ Layout-path | {'180-degrees'} | +| | } | | +| | }, | | +| REQ | Application-comments | {REQ #constraint-name {"19"},<br>PERM #external-data {ANY_VALUE}} | + +##### SPECIFIC: + +| | | | +|------|--------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------| +| CASE | \$DAC OF {<br>\$FDA: PERM Object-class<br>\$FPDA: REQ Object-class<br>}, | <br>{OBJECT_CLASS_ID_OF(SourcedContentVariable)}<br>{OBJECT_CLASS_ID_OF(SourcedContentVariable)} | +| REQ | Subordinates | {SUB_ID_OF(SpecificBlock)+}, | +| PERM | Application-comments | {REQ #constraint-name {"19"},<br>PERM #external-data {ANY_VALUE}} | + +#### 7.4.3.19 ArrangedContentVariable: ANY-FRAME-VARIABLE { + +##### GENERIC: + +| | | | +|------|--------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------| +| CASE | \$DAC OF { | | +| | \$PDA-FPDA: | | +| | REQ Generator-for-subordinates | {<construction-expr>::=SEQ<br>(OBJECT_CLASS_ID_OF(GenericBlock)...)}; | +| | REQ Position | {REQ #variable-position {<br>PERM #offset {ANY_VALUE},<br>PERM #separation {ANY_VALUE},<br>PERM #alignment {ANY_VALUE},<br>PERM #fill-order {'normal-order'}}}, | +| | REQ Dimensions | {REQ #horizontal-dimension<br>{REQ #fixed-dimension {ANY_VALUE}},<br>REQ #vertical-dimension<br>{REQ #fixed-dimension {ANY_VALUE}}} | +| | }}, | | +| REQ | Application-comments | {REQ #constraint-name {"17"},<br>PERM #external-data {ANY_VALUE}} | + +##### SPECIFIC: + +| | | | +|------|--------------------------|--------------------------------------------------------------------| +| CASE | \$DAC OF { | | +| | \$FDA: PERM Object-class | {OBJECT_CLASS_ID_OF(ArrangedContentVariable)} | +| | \$FPDA: REQ Object-class | {OBJECT_CLASS_ID_OF(ArrangedContentVariable)} | +| | }, | | +| REQ | Subordinates | {SUB_ID_OF(GenericBlock)+}, | +| PERM | Application-comments | {REQ #constraint-name {"17"},<br>PERM #external-data {ANY_VALUE}}} | + +#### 7.4.3.20 SourcedContentFixed: ANY-FRAME-VARIABLE { + +##### GENERIC: + +| | | | +|------|-----------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| CASE | \$DAC OF { | | +| | \$PDA-FPDA: | | +| | REQ Logical-source | {OBJECT_CLASS_ID_OF(CommonContent)}, | +| | REQ Position | {REQ #fixed-position<br>{REQ #horizontal-position{ANY_VALUE},<br>REQ #vertical-position{ANY_VALUE}}}, | +| | REQ Dimensions | {REQ #horizontal-dimension<br>{REQ #fixed-dimension {ANY_VALUE}},<br>REQ #vertical-dimension<br>{REQ #fixed-dimension {ANY_VALUE}<br> REQ #rule-b {ANY_VALUE}}}, | +| | CASE SUPERIOR (CompositeHeader CompositeFooter<br>(Layout-path)) OF { | | +| | {'270-degrees'}: | PERM Layout-path {'270-degrees'} | +| | {'180-degrees'}: | REQ Layout-path {'180-degrees'} | +| | } | | +| | }}, | | +| REQ | Application-comments | {REQ #constraint-name {"18"},<br>PERM #external-data {ANY_VALUE}} | + +##### SPECIFIC: + +| | | | +|------|--------------------------|--------------------------------------------------------------------| +| CASE | \$DAC OF { | | +| | \$FDA: PERM Object-class | {OBJECT_CLASS_ID_OF(SourcedContentFixed)} | +| | \$FPDA: REQ Object-class | {OBJECT_CLASS_ID_OF(SourcedContentFixed)} | +| | }, | | +| REQ | Subordinates | {SUB_ID_OF(SpecificBlock)+}, | +| PERM | Application-comments | {REQ #constraint-name {"18"},<br>PERM #external-data {ANY_VALUE}}} | + +#### 7.4.3.21 ArrangedContentFixed: ANY-FRAME-FIXED { + +##### GENERIC: + +| | | | +|------|----------------------------|-----------------------------------------------------------------------| +| CASE | \$DAC OF { | | +| | \$PDA-FPDA: | | +| REQ | Generator-for-subordinates | {<construction-expr>::=SEQ<br>(OBJECT_CLASS_ID_OF(GenericBlock)...)}; | + +| | | | +|----------------------------------------|--------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| REQ | Application-comments | {REQ #constraint-name {"16"},<br>PERM #external-data {ANY_VALUE}} | +| <b>SPECIFIC:</b> | | | +| CASE | \$DAC OF {<br>\$FDA: PERM Object-class<br>\$FPDA: REQ Object-class<br>}, | {OBJECT_CLASS_ID_OF(ArrangedContentFixed)}<br>{OBJECT_CLASS_ID_OF(ArrangedContentFixed)} | +| REQ | Subordinates | {SUB_ID_OF(GenericBlock)+}, | +| PERM | Application-comments | {REQ #constraint-name {"16"},<br>PERM #external-data {ANY_VALUE}} | +| <b>7.4.3.22 GenericBlock: BLOCK {</b> | | | +| <b>GENERIC:</b> | | | +| REQ | Object-class-identifier | {ANY_VALUE}, | +| REQ | Object-type | {'block'}, | +| REQ | Content-architecture-class | {\$FC \$FPC \$FPR \$FPG}, | +| PERM | Resource | {ANY_VALUE}, | +| PERM | Content-portions | {CONTENT_ID_OF<br>(Character-content-portion)+<br> CONTENT_ID_OF<br>(Raster-graphics-content-portion)<br> CONTENT_ID_OF<br>(Geometric-graphics-content-portion)}, | +| PERM | User-readable-comments | {ANY_STRING}, | +| PERM | User-visible-name | {ANY_STRING}, | +| PERM | Position | {REQ #fixed-position<br>{REQ #horizontal-position {ANY_VALUE},<br>REQ #vertical-position {ANY_VALUE}}}, | +| PERM | Dimensions | {REQ #horizontal-dimension<br>{REQ #fixed-dimension {ANY_VALUE}},<br>REQ #vertical-dimension<br>{REQ #fixed-dimension {ANY_VALUE}}}, | +| REQ | Application-comments | {REQ #constraint-name {"29"},<br>PERM #external-data {ANY_VALUE}} | +| <b>SPECIFIC:</b> | | | +| CASE | \$DAC OF {<br>\$FDA: PERM Object-class<br>\$FPDA: REQ Object-class<br>}, | {OBJECT_CLASS_ID_OF(GenericBlock)}<br>{OBJECT_CLASS_ID_OF(GenericBlock)} | +| CASE | GenericBlock(object-class)<br>REQ Content-portions | OF {VOID:<br>{CONTENT_ID_OF(Character-content-portion)+<br> CONTENT_ID_OF(Raster-graphics-content-portion)<br> CONTENT_ID_OF(Geometric-graphics-content-portion)}} | +| PERM | Application-comments | {REQ #constraint-name {"29"},<br>PERM #external-data {ANY_VALUE}} | +| <b>SPECIFIC_AND_GENERIC:</b> | | | +| PERM | Presentation-style | {STYLE_ID_OF(P-Style1)<br> STYLE_ID_OF(P-Style4)<br> STYLE_ID_OF(P-Style3)} | +| <b>7.4.3.23 SpecificBlock: BLOCK {</b> | | | +| <b>SPECIFIC:</b> | | | +| PERM | Presentation-style | {STYLE_ID_OF(P-Style1)<br> STYLE_ID_OF(P-Style4)<br> STYLE_ID_OF(P-Style3)<br> STYLE_ID_OF(P-Style2)}, | +| REQ | Content-portions | {CONTENT_ID_OF(Character-content-portion)+<br> CONTENT_ID_OF(Raster-graphics-content-portion)<br> CONTENT_ID_OF(Geometric-graphics-content-portion)}, | +| PERM | Application-comments | {REQ #constraint-name {"30"},<br>PERM #external-data {ANY_VALUE}} | + +## 7.5 Layout style constituent constraints + +### 7.5.1 Macro definitions + +``` +DEFINE(LayoutObjectClasses, " + OBJECT_CLASS_ID_OF(PageSet) + |OBJECT_CLASS_ID_OF(Page) + |OBJECT_CLASS_ID_OF(RectoPage) + |OBJECT_CLASS_ID_OF(VersoPage) + |OBJECT_CLASS_ID_OF(BasicBody) + |OBJECT_CLASS_ID_OF(VariableCompositeBody) + |OBJECT_CLASS_ID_OF(BasicFloat) + |OBJECT_CLASS_ID_OF(SnakingColumns) + |OBJECT_CLASS_ID_OF(SynchronizedColumns) + |OBJECT_CLASS_ID_OF(ColumnFixed) + |OBJECT_CLASS_ID_OF(ColumnVariable) + ") + +DEFINE(SameLayoutObject, " + REQ{REQ #logical-object{<object-id-expr>::=PREC-OBJ(CURR-OBJ);} + |REQ#logical-object{'null'}}, + PERM #layout-object{'page'} + ") +``` + +### 7.5.2 Factor constraints + +#### 7.5.2.1 **FACTOR ANY-LAYOUT-STYLE {** + +| | | | +|-------------|-------------------------|---------------| +| <b>REQ</b> | Layout-style-identifier | {ANY_VALUE}, | +| <b>PERM</b> | User-readable-comments | {ANY_STRING}, | +| <b>PERM</b> | User-visible-name | {ANY_STRING}} | + +### 7.5.3 Constituent constraints + +#### 7.5.3.1 L-Style1: ANY-LAYOUT-STYLE { + +-- this style is used for the constituent constraint Passage only -- + +``` +CASE DocumentProfile(Generic-layout-structure) OF { + {'complete-generator-set'}: + PERM Layout-object-class {OBJECT_CLASS_ID_OF(PageSet)}, + PERM New-layout-object {OBJECT_CLASS_ID_OF(PageSet)}, + PERM Indivisibility {$LayoutObjectClasses + |ANY_STRING|'page'|'null'} + VOID: + PERM Indivisibility {ANY_STRING|'page'|'null'} + } +} +``` + +-- ANY\_STRING is interpreted as representing the name of a layout category -- + +#### 7.5.3.2 L-Style2: ANY-LAYOUT-STYLE { + +-- this style is used for the constituent constraints BodyText, and Number -- + +``` +CASE DocumentProfile(Generic-layout-structure) OF { + {'complete-generator-set'}: + PERM Indivisibility {$LayoutObjectClasses + |ANY_STRING|'page'|'null'}, + PERM New-layout-object {$LayoutObjectClasses + |ANY_STRING|'page'|'null'} + VOID: + PERM Indivisibility {ANY_STRING|'page'|'null'}, + PERM New-layout-object {ANY_STRING|'page'|'null'} + }, + PERM Layout-category {ANY_STRING}, + PERM Same-layout-object {$SameLayoutObject}, + PERM Concatenation {ANY_VALUE}, + PERM Offset {ANY_VALUE}, + PERM Separation {PERM #leading-edge{ANY_INTEGER}, + PERM #trailing-edge{ANY_INTEGER}}, + PERM Block-alignment {ANY_VALUE}, + PERM Synchronization {ANY_VALUE}} +``` + +#### 7.5.3.3 L-Style3: ANY-LAYOUT-STYLE { + +-- this style is used for the constituent constraints *CommonText* and *PageNumber* -- + +| | | | +|------|-----------------|-------------------------------------------------------------------------| +| PERM | Concatenation | {ANY_VALUE}, | +| PERM | Offset | {ANY_VALUE}, | +| PERM | Block-alignment | {ANY_VALUE}, | +| PERM | Separation | {PERM #leading-edge{ANY_INTEGER},<br>PERM #trailing-edge{ANY_INTEGER}}} | + +#### 7.5.3.4 L-Style4: ANY-LAYOUT-STYLE { + +-- this style is used for the constituent constraints *NumberedSegment* and *Paragraph* -- + +CASE DocumentProfile(Generic-layout-structure) OF { +   {'complete-generator-set': +     PERM Indivisibility               {\$LayoutObjectClasses +                                   |ANY\_STRING|'page'|'null'}, +     PERM Layout-object-class         {OBJECT\_CLASS\_ID\_OF(PageSet)}, +     PERM New-layout-object           {\$LayoutObjectClasses +                                   |ANY\_STRING|'page'|'null'} +   VOID: +     PERM Indivisibility               {ANY\_STRING|'page'|'null'}, +     PERM New-layout-object           {ANY\_STRING|'page'|'null'} +   }, + PERM Same-layout-object             {\$SameLayoutObject}, + PERM Synchronization               {ANY\_VALUE}} + -- ANY\_STRING is interpreted as representing the name of a layout category -- + +#### 7.5.3.5 L-Style5: ANY-LAYOUT-STYLE { + +-- this style is used for the constituent constraints *BodyRaster* and *BodyGeometric* -- + +CASE DocumentProfile(Generic-layout-structure) OF { +   {'complete-generator-set': +     PERM New-layout-object           {\$LayoutObjectClasses +                                   |ANY\_STRING|'page'|'null'} +   VOID: +     PERM New-layout-object           {ANY\_STRING|'page'|'null'} +   }, + -- ANY\_STRING is interpreted as representing the name of a layout category -- + PERM Layout-category               {ANY\_STRING}, + PERM Offset                         {ANY\_VALUE}, + PERM Same-layout-object             {\$SameLayoutObject}, + PERM Separation                     {PERM #leading-edge {ANY\_INTEGER}, +                                       PERM #trailing-edge {ANY\_INTEGER}}, + PERM Block-alignment               {ANY\_VALUE}, + PERM Synchronization               {ANY\_VALUE}} + +#### 7.5.3.6 L-Style6: ANY-LAYOUT-STYLE { + +-- this style is used for the constituent constraint *FootnoteText* -- + +| | | | +|------|-----------------|---------------| +| REQ | Layout-category | {"Footnote"}, | +| PERM | Concatenation | {ANY_VALUE}, | + +CASE DocumentProfile(Generic-layout-structure) OF { +   {'complete-generator-set': +     PERM Indivisibility               {OBJECT\_CLASS\_ID\_OF(FootnoteArea) +                                   |'page'|'null'} +   VOID: +     PERM Indivisibility               {ANY\_STRING|'page'|'null'} +   }, + PERM Offset                         {ANY\_VALUE}, + PERM Block-alignment               {ANY\_VALUE}, + PERM Separation                     {PERM #leading-edge {ANY\_INTEGER}, +                                       PERM #trailing-edge {ANY\_INTEGER}}} + +#### 7.5.3.7 L-Style7: ANY-LAYOUT-STYLE { + +-- this style is used for the constituent constraint *Footnote* only -- + +| | | | +|------|--------------------|-----------------------| +| PERM | Same-layout-object | {\$SameLayoutObject}} | +|------|--------------------|-----------------------| + +#### 7.5.3.8 L-Style8: ANY-LAYOUT-STYLE { + +-- this style is used for the constituent constraints CommonRaster and CommonGeometric -- + +| | | | +|------|-----------------|---------------------------------------------------------------------------| +| PERM | Offset | {ANY_VALUE}, | +| PERM | Block-alignment | {ANY_VALUE}, | +| PERM | Separation | {PERM #leading-edge {ANY_INTEGER},<br>PERM #trailing-edge {ANY_INTEGER}}} | + +#### 7.5.3.9 L-Style9: ANY-LAYOUT-STYLE { + +-- this style is used for the constituent constraint FootnoteNumber -- + +| | | | +|------|-----------------|---------------------------------------------------------------------------| +| REQ | Layout-category | {"Footnote"}, | +| PERM | Offset | {ANY_VALUE}, | +| PERM | Block-alignment | {ANY_VALUE}, | +| PERM | Separation | {PERM #leading-edge {ANY_INTEGER},<br>PERM #trailing-edge {ANY_INTEGER}}} | + +#### 7.5.3.10 L-Style10: ANY-LAYOUT-STYLE { + +-- this style is used for the constituent constraints FootnoteReference only -- + +CASE DocumentProfile(Generic-layout-structure) OF { +  {'complete-generator-set'}: +    PERM Indivisibility                    {\$LayoutObjectClasses +                                          |ANY\_STRING|'page'|'null'} + +VOID: +  PERM Indivisibility                    {ANY\_STRING|'page'|'null'} + +                                          }, + +| | | | +|------|--------------------|---------------------------------------------------------------------------| +| PERM | Layout-category | {ANY_STRING}, | +| PERM | Same-layout-object | {\$SameLayoutObject}, | +| PERM | Concatenation | {ANY_VALUE}, | +| PERM | Offset | {ANY_VALUE}, | +| PERM | Separation | {PERM #leading-edge {ANY_INTEGER},<br>PERM #trailing-edge {ANY_INTEGER}}, | +| PERM | Block-alignment | {ANY_VALUE}} | + +#### 7.5.3.11 L-Style11: ANY-LAYOUT-STYLE { + +-- this style is used for the constituent constraint Footnotebody -- + +| | | | +|------|--------------------|-----------------------| +| PERM | Same-layout-object | {\$SameLayoutObject}, | +|------|--------------------|-----------------------| + +CASE DocumentProfile(Generic-layout-structure) OF { +  {'complete-generator-set'}: +    PERM Indivisibility                    {OBJECT\_CLASS\_ID\_OF(FootnoteArea) +                                          |'page'|'null'} + +VOID: +  PERM Indivisibility                    {ANY\_STRING|'page'|'null'}}} + +## 7.6 Presentation style constituent constraints + +### 7.6.1 Macro definitions + +-- No macro definitions are applicable to this subclause. -- + +### 7.6.2 Factor constraints + +#### 7.6.2.1 FACTOR ANY-PRESENTATION-STYLE { + +| | | | +|------|-------------------------------|---------------| +| REQ | Presentation-style-identifier | {ANY_VALUE}, | +| PERM | User-visible-name | {ANY_STRING}, | +| PERM | Border | {ANY_VALUE}, | +| PERM | User-readable-comments | {ANY_STRING}} | + +### 7.6.3 Constituent constraints + +#### 7.6.3.1 P-Style1: ANY-PRESENTATION-STYLE { + +-- this style is used for the constituent constraints BodyText, Number, FootnoteNumber, FootnoteReference, +-- FootnoteText, GenericBlock and SpecificBlock -- + +``` + +PERM Presentation-attributes { + PERM #character-attributes { + PERM #alignment {ANY_VALUE}, + PERM #character-fonts {ANY_VALUE}, + PERM #character-orientation {'0-degrees' + |'90-degrees'}, + PERM #character-path {ANY_VALUE}, + PERM #character-spacing {ANY_VALUE}, + PERM #code-extension-announcers {$CDEXTEN}, + PERM #first-line-offset {ANY_VALUE}, + PERM #graphic-character-sets {$PERMIT-GRCHAR}, + PERM #graphic-character-sub-repertoire {ANY_VALUE}, + PERM #graphic-rendition {$GRAPHICRENDITIONS}, + PERM #indentation {ANY_VALUE}, + PERM #itemization {ANY_VALUE}, + PERM #kerning-offset {ANY_VALUE}, + PERM #line-layout-table {ANY_VALUE}, + PERM #line-progression {ANY_VALUE}, + PERM #line-spacing {ANY_VALUE}, + PERM #orphan-size {ANY_VALUE}, + PERM #proportional-line-spacing {ANY_VALUE}, + PERM #widow-size {ANY_VALUE}}}} +``` + +#### 7.6.3.2 P-Style2: ANY-PRESENTATION-STYLE { + +-- *this style is used for the constituent constraints CommonText, PageNumber and SpecificBlock* -- + +``` + +PERM Presentation-attributes { + PERM #character-attributes { + PERM #alignment {ANY_VALUE}, + PERM #character-fonts {ANY_VALUE}, + PERM #character-orientation {'0-degrees' + |'90-degrees'}, + PERM #character-path {'0-degrees' + |'180-degrees' + |'270-degrees'}, + PERM #character-spacing {ANY_VALUE}, + PERM #code-extension-announcers {$CDEXTEN}, + PERM #first-line-offset {ANY_VALUE}, + PERM #graphic-character-sets {$PERMIT-GRCHAR}, + PERM #graphic-character-sub-repertoire {ANY_VALUE}, + PERM #graphic-rendition {$GRAPHICRENDITIONS}, + PERM #indentation {ANY_VALUE}, + PERM #itemization {ANY_VALUE}, + PERM #kerning-offset {ANY_VALUE}, + PERM #line-progression {ANY_VALUE}, + PERM #line-spacing {ANY_VALUE}, + PERM #line-layout-table {ANY_VALUE}, + PERM #proportional-line-spacing {ANY_VALUE}}}} +``` + +#### 7.6.3.3 P-Style3: ANY-PRESENTATION-STYLE { + +-- *this style is used for the constituent constraints BodyRaster, CommonRaster, GenericBlock and SpecificBlock* -- + +``` + +PERM Presentation-attributes { + PERM #raster-graphics-attributes { + PERM #image-dimensions {ANY_VALUE}, + PERM #clipping {ANY_VALUE}, + PERM #pel-spacing {ANY_VALUE}, + PERM #spacing-ratio {ANY_VALUE}}}} +``` + +#### 7.6.3.4 P-Style4: ANY-PRESENTATION-STYLE { + +-- *this style is used for the constituent constraints BodyGeometric, CommonGeometric, GenericBlock and SpecificBlock* -- + +``` + +PERM Presentation-attributes { + PERM #geometric-graphics-attributes { + PERM #picture-dimensions {ANY_VALUE}, + PERM #picture-orientation {ANY_VALUE}, + PERM #text-rendition {PERM #fonts-list {ANY_VALUE}, +``` + +## 7.7 Content portion constituent constraints + +### 7.7.1 Macro definitions + +-- No macro definitions are applicable to this subclause. -- + +### 7.7.2 Factor constraints + +#### 7.7.2.1 FACTOR ANY-CONTENT { + +CASE \$DAC OF { + +\$FDA: + +REQ Content-identifier-layout {ANY\_VALUE} + +\$PDA: + +REQ Content-identifier-logical {ANY\_VALUE} + +-- This attribute is specified, if the content portion is associated with a basic logical object +-- or a basic logical object class. -- + +|REQ Content-identifier-layout {ANY\_VALUE} + +-- This attribute is specified, if the content portion is associated with a basic layout object class. -- + +\$FPDA: + +REQ Content-identifier-layout {ANY\_VALUE}, + +REQ Content-identifier-logical {ANY\_VALUE} + +-- Both attributes are specified, if the content portion associated with a basic logical object +-- and a basic layout object. -- + +|REQ Content-identifier-layout {ANY\_VALUE} + +-- This attribute is specified, if the content portion is associated with a basic layout object class. -- + +|REQ Content-identifier-logical {ANY\_VALUE} + +-- This attribute is specified, if the content portion is associated with a basic logical object class -- + +} + +### 7.7.3 Constituent constraints + +#### 7.7.3.1 Character-content-portion: ANY-CONTENT { + +PERM Type-of-coding {ASN.1{2 8 3 6 0}}, + +PERM Alternative-representation {ANY\_STRING}, + +PERM Content-information + +| | | | +|------------|---------------------|-----------------------| +| {CHARACTER | {#STAB | {ANY_VALUE} | +| | #SHS | {0,1,2,3,4} | +| | #SGR | {\$GRAPHICRENDITIONS} | +| | #SVS | {ANY_VALUE} | +| | #SLS | {ANY_VALUE} | +| | #SCS | {ANY_VALUE} | +| | #SRS | {ANY_VALUE} | +| | #JFY | {0} | +| | #CR | | +| | #LF | | +| | #VPB | | +| | #VPR | | +| | #PLD | | +| | #PLU | | +| | #SUB | | +| | #BPH | | +| | #NBH | | +| | #SOS | | +| | #ST | | +| | #SP | | +| | #LS0 | | +| | #LS1R | | +| | #LS2R | | +| | #LS3R | | +| | #SS2 | | +| | #SS3 | | +| | #ESC{\$DEG-CORE-G0} | | +| | #ESC{\$DEG-646-G0} | | + +``` + +#ESC{$DEG-ANY-G1} +#ESC{$DEG-ANY-G2} +#ESC{$DEG-ANY-G3} +#ESC{$DEG-EMPTY-G1} +}...} + +``` + +#### 7.7.3.2 Raster-graphics-content-portion: ANY-CONTENT { + +``` + +PERM Type-of-coding {ASN.1{2 8 3 7 0} -- T.6 encoding -- + |ASN.1{2 8 3 7 1} -- T.4 one-dimensional encoding -- + |ASN.1{2 8 3 7 2} -- T.4 two dimensional encoding -- + |ASN.1{2 8 3 7 3} -- bitmap encoding --}, + +PERM Coding-attributes{ + PERM #raster-graphics-coding-attributes{ + PERM #number-of-lines {>0}, + REQ #number-of-pels-per-line {>=0}, + PERM #compression {ANY_VALUE}}, + PERM Alternative-representation {ANY_STRING}, + PERM Content-information {RASTER}} + +``` + +#### 7.7.3.3 Geometric-graphics-content-portion: ANY-CONTENT { + +``` + +PERM Type-of-coding {ASN.1{2 8 3 8 0}}, +PERM Alternative-representation {ANY_STRING}, +PERM Content-information {GEOMETRIC}} + +``` + +# 8 Interchange format + +## 8.1 Interchange format + +For conformance to this Profile, the ODIF interchange format class A shall be used. This form of ODIF is defined in CCITT Rec T.415 | ISO/IEC 8613-5. The value of the document profile attribute “interchange format” is 'if-a'. + +## 8.2 Document application profile object identifier + +The value for the document profile attribute “document application profile” for this interchange format is represented by the following object identifier: ASN.1 {2 8 4 0 26 0} + +## 8.3 Encoding of application comments + +The encoding of the attribute “application comments” is defined in this encoding as an octet string as specified in CCITT Rec. T.415 | ISO/IEC 8613-5. This document application profile requires that the encoding within that octet string be in accordance with the ASN.1 syntax specified in the following module definition: + +``` + +FOD-DAPSpecification +DEFINITIONS ::= BEGIN +EXPORTS Appl-Comm-Encoding; + +Appl-Comm-Encoding ::= SEQUENCE { +constraint-name [0] IMPLICIT PrintableString OPTIONAL, +external-data [1] IMPLICIT OCTET STRING OPTIONAL } +END + +``` + +## 8.4 Data lengths + +The maximum length of data values of the type OCTET STRING, as defined in CCITT Rec. X.208 | ISO/IEC 8824 in data streams which may be encoded in accordance with this document application profile is 32 767 octets. If it is required to encode an octet string of greater length than this, constructed type encoding shall be used. That is, data values greater than 32 767 in length shall be split into a sequence of strings shorter than 32 767, each of which is encoded using a primitive type. + +# **Annex A** + +## **Amendments and technical corrigenda** + +(This annex forms an integral part of this Recommendation) + +## **A.1 Amendments** + +### **A.1.1 Amendments to the base standard** + +The amendments applicable to this Recommendation include text to be included in CCITT Rec. T.411 | ISO/IEC 8613-1 as the following annexes: + +- Annex E: Use of ISO/IEC 10021 (MOTIS) to interchange documents conforming to CCITT Rec. T.410 Series | ISO 8613 – published as [First extension to the CCITT Rec. T.410 Series (1988), Addendum II | ISO 8613-1 (1989): Amendment 1]; +- Annex F: Document Application Profile Proforma and Notation – published as CCITT Rec. T.411 – Annex F (1991) | ISO 8613-1 (1989): Addendum 1; +- Annex G: Conformance testing methodology – published as ISO 8613-1 (1989): Amendment 2; +- Annex H: Recording of documents conforming to CCITT Rec. T.410 Series | ISO/IEC 8613 on flexible disk cartridges conforming to ISO 9293 – currently a Draft Amendment 5 to ISO 8613-1 (1989) – Annex H. + +This Recommendation does not include the following features of the amendment: + +- Addendum on security – published as [First extension to the CCITT Rec. T.410 Series (1988), Addendum V | ISO 8613 (1989) Addendum 4]; +- Addendum on styles – published as [First extension to the CCITT Rec. T.410 Series (1988), Addendum IV | ISO 8613 (1989) Addendum 6]; +- Addendum on alternative representation – published as [First extension to the CCITT Rec. T.410 Series (1988), Addendum III | ISO 8613 (1989) Addendum 3]; +- Addendum on colour – published as [Revision of the CCITT Rec. T.410 Series contained in COM VIII – R30-E Addendum 2 | ISO 8613 (1989) – Amendment 2]; +- Addendum on tiled raster graphics – published as [First extension to the CCITT Rec. T.410 Series (1988) Addendum I | ISO 8613 (1989) – Addendum 1]; +- Addendum on streams – published as ISO 8613 (1989) – Amendment 5. + +### **A.1.2 Proposed changes to standards due to defects** + +This amendment addresses the inclusion of the CCITT Rec. T.410 Series (1988) | ISO/IEC 8613 (1988) – Technical corrigenda 1, 2 and 3. + +## **A.2 Technical corrigenda** + +### **A.2.1 Technical corrigenda to this Recommendation** + +There are no technical corrigenda specific to this Recommendation. + +## **A.3 Versions of the ODA Specification** + +The version of the ODA International Standard defined in A.1 is known as version 1.1. The associated date is 1992-01-01. The version of the ODA International Standard including all features of the amendments, addenda and technical corrigenda mentioned in A.1 is known as version 1.2. The associated date is 1992-07-01. + +The entries for ODA version for this document application profile is: + +- standard or recommendation: “CCITT Rec. T.410 Series (1988) | ISO 8613 (1989); version 1.1”; +- publication date: “1992-01-01”. + +# Annex B + +## Recommended practices + +(This annex does not form an integral part of this Recommendation) + +## B.1 Transfer methods for ODA + +### B.1.1 Conveyance of ODA over CCITT Recommendation X.400-1984 + +This describes how ODA body parts are to be encoded for transmission over a CCITT X.400-1984 service. + +An ODA body part is encoded as OdaBodyPart in the definition given below: + +**OdaBodyPart ::= SEQUENCE { OdaBodyPartParameters, OdaData }** + +**OdaBodyPartParameters ::= SET {** + +**document-application-profile** + +**[0] IMPLICIT OBJECT IDENTIFIER,** + +**document-architecture-class** + +**[1] IMPLICIT INTEGER {** + +**formatted (0),** + +**processable (1),** + +**formatted-processable (2) }** + +**OdaData ::= SEQUENCE OF Interchange-Data-Element** + +NOTE – It is recommended to transfer an ODA document as a single body part with tag 12: + +**Oda [12] IMPLICIT OCTETSTRING** + +The content of the octet string is encoded as OdaBodyPart, defined above. However, this is out of the scope of this Profile. + +### B.1.2 Conveyance of ODA over FTAM + +This describes the FTAM Document Type to be used for minimal storage and transfer capabilities of ODA data streams. It is recognized that enhanced capabilities may at some point be added. + +When using FTAM to transfer an ODA file, the FTAM-3, “ISO FTAM Unstructured Binary”, document type shall be specified. + +However, since files that do not contain ODA data streams can have the same document type, it is left up to the user of application programs that remotely access files using FTAM to know that a given file contains an ODA data stream. + +### B.1.3 Conveyance of ODA over DTAM + +This provides for information concerning the interchange of ODA based documents with DTAM protocols. + +DTAM (Document Transfer and Manipulation) is defined in the T.430-Series of CCITT Recommendations and is, like ODA, an integral part of the T.400-Series of CCITT Recommendations named Open Document Architecture, Transfer and Manipulation. + +The T.520-Series of CCITT Recommendations contain Communication Application Profiles (CAP). CCITT Recommendation T.522 describes the Communication Application Profile BT1 for document bulk transfer. CCITT Recommendation T.522 is applicable for the Profile published in this Recommendation. + +NOTE – The use of BT1 within the end-to-end oriented Telematic Services Telefax 4 and Teletex is described in 7.1/T.561 and in 7.1/T.562. + +### B.1.4 Conveyance of ODA over flexible disks + +The recommended method for interchanging ODA documents between systems by the exchange of magnetically recorded Flexible Disk Cartridges by the use of an annex to CCITT Rec. T.411 | ISO/IEC 8613-1 (to be published), “*Recording of Documents Conforming to ISO 8613 on Flexible Disk Cartridges Conforming to ISO 9293*”. This annex provides for recording each ODA document as a separate file as defined by ISO 9293. + +## B.2 Font reference + +The recommended method for specifying a font reference is to be based on ISO/IEC 9541. + +Font sizes from 6 to 72 points (100 to 1200 BMU) are intended to be supported by implementation conforming to this Recommendation. All other values of font sizes may additionally be supported, but implementations may also support using some form of fallback. + +The minimum font properties and values from ISO/IEC 9541 that are to be specified in a Font-Attribute-Set are those specified by the following document application profile notation. + +``` +Font-Attribute-Set { + PERM Fontname {ANY_VALUE}, + PERM Standard-Version {ANY_VALUE}, + PERM Data-Source {ANY_VALUE}, + PERM Design-Source {ANY_VALUE}, + PERM Font-Family-Name {ANY_VALUE}, + PERM Posture {'upright' | 'italic-forward'}, + PERM Weight {'light' | 'medium' | 'bold'}, + PERM Proportionate-Width {ANY_VALUE}, + PERM Glyph-Complement { + PERM #Included-Glyph-Collections {ANY_VALUE}, + PERM #Excluded-Glyph-Collections {ANY_VALUE}, + PERM #Included-Glyphs {ANY_VALUE}, + PERM #Excluded-Glyphs {ANY_VALUE} + }, + PERM Design-Size {ANY_VALUE}, + PERM Min-Size { + PERM #Numerator {100 .. 1200}, + PERM #Denominator {1} + }, + PERM Max-Size { + PERM #Numerator {100 .. 1200}, + PERM #Denominator {1} + }, + -- BMU Units equivalent to range of 6..72 point sizes -- + PERM Design-Group { + PERM #Class {ANY_VALUE}, + PERM #Subclass {ANY_VALUE}, + PERM #Specific-Group {ANY_VALUE} + }, + PERM Structure {ANY_VALUE}, + PERM Writing-Modes { + MUL { + REQ #Writing-Mode-Name {ANY_VALUE}, + PERM #Nominal-Escapement-Direction {ANY_VALUE}, + PERM #Escapement-Class {ANY_VALUE}, + PERM #Average-Escapement-X {ANY_VALUE}, + PERM #Average-Escapement-Y {ANY_VALUE} + } + } +} +``` + +## B.3 ISO/IEC 8632 (CGM) constraints for this document application profile + +It is recommended that geometric graphics content information contain only those elements listed in this portion of the document, in addition to the constraints imposed by CCITT Rec. T.415 | ISO/IEC 8613-5. It is believed that this subset of the CGM is sufficiently implemented to enable interworking of geometric graphics for application conforming to this document application profile. + +Where an element has parameters, recommended constraints on the values are given. The -- symbol indicates that there is no recommended constraint. + +Requirements in ISO/IEC 8632 and CCITT Rec. T.415 | ISO/IEC 8613-5 concerning mandatory elements, parameters shall be fulfilled. + +### B.3.1 Delimiter elements + +No-op An arbitrary sequence of n octets. Where n = 0, 1, ..., 32 767. The sequence of zero or more octets is for padding purposes. + +Begin Metafile Support will be provided for strings with a length up to 254 octets, except for data records which will support strings with a length up to 32 767 octets. + +End Metafile + +| | | +|---------------|------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Begin Picture | Support will be provided for strings up with a length to 254 octets, except for data records which will support strings with a length up to 32 767 octets. | +|---------------|------------------------------------------------------------------------------------------------------------------------------------------------------------| + +Begin Picture Body + +End Picture + +### **B.3.2 Metafile descriptor elements** + +| | | +|-------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Metafile Version | 1 | +| Metafile Description | Support will be provided for strings with a length up to 254 octets, except for data records which will support strings with a length up to 32 767 octets. The METAFILE DESCRIPTION string parameter will be used to include the sub-string "ISO FOD26" to the label content information as conforming to this Profile.<br><br>In addition, generators of content are encouraged to append a sub-string that identifies the company and product that produced the CGM. | +| VDC Type | Integer | +| Integer Precision | 16 | +| Real Precision | (0, 9, 23), (1, 16, 16) | +| Index Precision | 16 | +| Colour Precision | 8, 16 | +| Colour Index Precision | 8, 16 | +| Maximum Colour Index | 0 .. 63 | +| Colour Value Extent | | +| Metafile Element List | | +| Metafile Defaults Replacement | | +| Font List | All fonts referenced in the metafile shall be defined. Font referencing in FONT LISTS using ISO/IEC 9541 names is preferred, but font names may be specified using proprietary font names. | +| Character Set List | All character sets referenced in the metafile shall be defined in CHARACTER SET LIST. Permissible character sets are the same as for character content architecture. | +| Character Coding Announcer | | + +### **B.3.3 Picture descriptor elements** + +| | | +|--------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Scaling Mode | The Scale Factor parameter of SCALING MODE element is always a 32-bit floating point value, even when the REAL PRECISION has selected fixed point for other real numbers. It is not apparent in ISO/IEC 8632 what the precision of this floating point value is when fixed point has been selected. Its precision shall be (0, 9, 23). | +| Colour Selection Mode | Indexed | +| Line Width Specification Mode | Scaled | +| Marker Size Specification Mode | Scaled | +| Edge Width Specification Mode | Scaled | +| VDC Extent | | +| Background Colour | | + +### **B.3.4 Control elements** + +| | | +|-----------------------|-------------------------| +| VDC Integer Precision | 16 | +| VDC Real Precision | (0, 9, 23), (1, 16, 16) | +| Auxiliary Colour | -- | +| Transparency | Transparent | +| Clip Rectangle | -- | +| Clip Indicator | -- | + +### **B.3.5 Graphical primitive elements** + +| | | +|----------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Polyline | Support for point lists with up to 255 vertices. | +| Disjoint Polyline | Support for point lists with up to 255 vertices. | +| Polymarker | Support for point lists with up to 255 vertices. | +| Text | Support will be provided for strings with a length up to 254 octets, except for data records which will support strings with a length up to 32 767 octets. Format effector control characters are disallowed in the string parameter. | +| Restricted Text | Support will be provided for strings with a length up to 254 octets, except for data records which will support strings with a length up to 32 767 octets. Format effector control characters are disallowed in the string parameter. | +| Append Text | Support will be provided for strings with a length up to 254 octets, except for data records which will support strings with a length up to 32 767 octets. Format effector control characters are disallowed in the string parameter. | +| Polygon | Support for point lists with up to 255 vertices. | +| Polygon Set | Support for point lists with up to 255 vertices. | +| Cell Array | -- | +| Rectangle | -- | +| Circle | -- | +| Circular Arc 3 Point | -- | +| Circular Arc 3 Point Close | -- | +| Circular Arc Centre | -- | +| Circular Arc Centre Close | -- | +| Ellipse | -- | +| Elliptical Arc | -- | +| Elliptical Arc Close | -- | + +### **B.3.6 Attribute elements** + +| | | +|---------------------|-----| +| Line Bundle Index | 1 | +| Line Type | 1-5 | +| Line Width | -- | +| Line Colour | -- | +| Marker Bundle Index | 1 | +| Marker Type | 1-5 | +| Marker Size | -- | +| Marker Colour | -- | + +| | | +|-------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Text Bundle Index | 1 | +| Text Font Index | All fonts referenced (indexed by TEXT FONT INDEX) in the metafile shall be defined in FONT LIST either in presentation parameters of CCITT Rec. T.410 Series ISO/IEC 8613 or in ISO/IEC 8632. | +| Text Precision | 0 (string) | +| Character Expansion Factor | 1.0 | +| Character Spacing | 0.0 | +| Text Colour | -- | +| Character Height | -- | +| Character Orientation | -- | +| Text Alignment | -- | +| Character Set Index | All character sets referenced in the metafile (indexed by CHARACTER SET INDEX) shall be defined in CHARACTER SET LIST. The only character sets which may be designated in G0 are ISO/IEC 646:1991 IRV or versions of ISO/IEC 646:1991. Other character sets shall be designated in G1, G2 or G3. | +| Alternate Character Set Index | All character sets referenced in the metafile (indexed by ALTERNATE CHARACTER SET INDEX) shall be defined in CHARACTER SET LIST. | +| Fill Bundle Index | 1 | +| Interior Style | -- | +| Fill Colour | -- | +| Hatch Index | Negative values are prohibited. | +| Pattern Index | 1 | +| Edge Bundle Index | 1 | +| Edge Type | 1 | +| Edge Width | 1.0 | +| Edge Colour | -- | +| Edge Visibility | 0 (off) | +| Fill Reference Point | -- | +| Pattern Table | The PATTERN TABLE element has an unspecified effect when it appears in a picture subsequent to any graphical primitives. The PATTERN TABLE element shall appear prior to any graphical primitive element to assure that interpreting systems without dynamic pattern update can render the intended effect. The minimum support for the length of the Colour Array parameter for the PATTERN TABLE element is 2048. This will support 8 patterns of $16 \times 16$ , 2 patterns of $32 \times 32$ or 1 pattern of $32 \times 64$ . All indexes which are used in the metafile shall be defined. | +| Pattern Size | -- | +| Colour Table Specification | The COLOUR TABLE element has an unspecified effect when it appears in a picture subsequent to any graphical primitives. The COLOUR TABLE element shall appear prior to any graphical primitive elements to assure that interpreting systems without dynamic colour update can render the intended effect. The minimum support for the length of the Colour List parameter in the COLOUR TABLE element is 63. This will support a 64 (0..63) entry colour table. All indexes which are used in the metafile shall be defined. | +| Aspect Source Flags | Individuals | + +### B.3.7 External elements + +#### Message + +The presentation of a message string may not be appropriate for all applications. No requirement for the formatted presentation of the message string has been placed on the Interpreter. Only the No Action Flag needs to be supported. Support for string lengths up to 254. + +#### Application Data + +Support will be provided for strings with a length up to 254 octets, except for data records which will support strings with a length up to 32 767 octets. + +# Annex C + +## Bibliography + +(This annex does not form an integral part of this Recommendation) + +- ITU-T Recommendation T.52 (1993), *Non-latin coded character sets for telematic services*. +- CCITT Recommendation T.502 (1991), *Document application profile PM-11 for the interchange of character content documents in processable and formatted forms*. +- CCITT Recommendation T.505 (1991), *Document application profile PM-26 for the interchange of mixed content documents in processable and formatted forms*. +- ISO 8571:1988, *Information processing systems – Open systems interconnection – File transfer access and management*. +- ISO/IEC 9070:1991, *Information technology – SGML support facilities – Registration procedures for public text owner identifiers*. +- ISO/IEC TR 9573:1988, *Information processing – SGML support facilities – Techniques for using SGML*. +- ISO/IEC 10021:1990, *Information technology – Text communication – Message-Oriented Text Interchange Systems (MOTIS)*. \ No newline at end of file diff --git a/marked/T/T-REC-T.510-199303-I_PDF-E/raw.md b/marked/T/T-REC-T.510-199303-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..fb98891b427a5706e1e7686543da1a7afbbb3dcf --- /dev/null +++ b/marked/T/T-REC-T.510-199303-I_PDF-E/raw.md @@ -0,0 +1,510 @@ + + +![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU and a lightning bolt symbol. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# T.510 + +(03/93) + +**TELEMATIC SERVICES** + +**TERMINAL EQUIPMENTS AND PROTOCOLS +FOR TELEMATIC SERVICES** + +--- + +**GENERAL OVERVIEW OF THE +T.510-SERIES RECOMMENDATIONS** + +**ITU-T Recommendation T.510** + +(Previously "CCITT Recommendation") + +--- + +# FOREWORD + +The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecommunication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +ITU-T Recommendation T.510 was prepared by the ITU-T Study Group VIII (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). + +# --- NOTES + +1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector. + +In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms “CCITT, CCIR or IFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. + +2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# CONTENTS + +| | <i>Page</i> | +|----------------------------------------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 Field of application ..... | 1 | +| 3 References ..... | 1 | +| 4 Definitions ..... | 1 | +| 5 Introduction to the definition of implementation requirements (IRs) ..... | 2 | +| 6 Requirements classification ..... | 3 | +| 7 Implementation model and actual implementation ..... | 4 | +| 8 Specification of implementation requirements ..... | 7 | +| 9 Implementation support statement (ISS) ..... | 9 | +| Annex A – Relationships between the DAPs, Implementation Requirements and Terminal Characteristics ..... | 11 | + + + +# GENERAL OVERVIEW OF THE T.510-SERIES RECOMMENDATIONS + +(Helsinki, 1993) + +# 1 Scope + +The T.510-Series Recommendations contains the specifications for implementation requirements (IR) in correspondence with the T.500-Series Recommendations. + +This Recommendation provides the necessary definitions required for the establishment of Recommendations within the T.510-Series. + +This Recommendation gives the guidelines on how to describe the requirements to DAP implementations to be used by an application. Specific requirements of telematic services are not covered by this series of Recommendations. + +This Recommendation defines an abstract implementation model in order to structure the IRs and to qualify the function units depending on the classes of requirements. + +This Recommendation defines the structure and the notation which have to be used for the description of IRs and how the tables can be used for support statement purposes. + +# 2 Field of application + +This Recommendation may be used as an introduction to the Recommendations of the T.510-Series. + +This Recommendation describes how the IRs are to be defined in the T.510-Series Recommendations and how they are to be interpreted. + +# 3 References + +- Rec. T.400-Series Recommendations *Document Transfer, Access and Manipulation*. +- Rec. T.500-Series Recommendation *Document Application Profiles*. +- Rec. T.560-Series Recommendation *Terminal Characteristics*. + +# 4 Definitions + +The terms between double quote marks are defined in this clause. + +**application:** The word “Application” is used as the generic term to represent the set of features, combining communication and document processing, on which end-users may perform operations. The “Applications” may depend on working methods and on allowed processing of documents. Examples of “Applications” are : open interchange of processable documents, cooperative working, etc. + +**conversion process:** The “Conversion” process is used to convert an ODA based format into another format (standardized format or proprietary format), and vice versa. This process should map the “Function Units” composing an ODA document to the corresponding features performed by the other format, if any. + +**DAP minimum implementation requirements (DMIR):** For each DAP, the DMIR identifies the set of requirements that all the “Implementations” should conform to, regardless of the “Applications”. This DMIR corresponds to the common kernel of requirements which will be implemented, and therefore will ensure interworking between “Applications” selecting the same DAP. + +**externalization/internalization process:** The “Externalization” process is used to encode the ODA based file into an ODIF data stream by using the coding rules expressed by ODIF (Recommendation T.415). Conversely, the “Internalization” process is used to decode an ODIF data stream into an ODA based file. + +**fall-back:** A “Fall-back” is a guideline for an alternative processing of a “Function Unit” that may be used by a particular process when the latter is unable to process directly that “Function Unit”. “Fall-backs” may only be used when they are allowed by IRs and solely by “Implementations” acting as receivers. + +**function unit (FU):** The “Function Units” are DAP constituent constraints, or combination of constraints, that will be used to specify DAP IRs. “Function Units” sometimes correspond exactly to end-user known document processing features. + +**generation:** An “Implementation” supports the “Generation” of a particular “Function Unit” if it can issue a data stream carrying the corresponding DAP constituent constraints. + +**imaging:** When acting as a receiver, an “Implementation” supports the “Imaging” of a particular “Function Unit” if the received “Function Unit” can be further processed by an imaging process according to the imaging information given by the constituents constraints forming that function unit. + +**implementation:** An “Implementation” is an actual realization (combination of hardware and/or software) that satisfies all or part of the requirements of a particular “Application” in terms of communication as well as in terms of document processing. + +**implementation support statement (ISS):** The ISS is a proforma to be used by vendors to state which IRs are actually supported by their “Implementation”. + +**layout:** When acting as a receiver, an “Implementation” supports the “Layout” of a particular “Function Unit” if the received “Function Unit” can be further processed by a layout process according to the layout information given by the constituents constraints forming that Function Unit. + +**point of control and observation (PCO):** A “Point of Control and Observation” is a point available to the user (or the tester) where data can be manipulated and/or observed. This point acts as a point of control when it is used to input some data in the “Implementation” in order to *control* the test procedure. On the contrary, this point acts as a point of observation when, after having performed some *control* on the “Implementation” under test, it is used to *observe* the behaviour of this “Implementation”. It is through the PCOs that the user will *see* the “Function Units”. + +**qualifier:** A “Qualifier” is a term used to specify the level of requirement attached to a particular “Function Unit” depending on the nature of the process to be performed. For example, the processing of a particular “Function Unit” may be *required* for the generation process while it may be *optional* for another process. + +**reception:** An “Implementation” supports the “Reception” of a particular “Function Unit” when it can interpret the corresponding constituents constraints and perform the appropriate processing. + +**retention:** When acting as a receiver, an “Implementation” supports the “Retention” of a particular “Function Unit” if this received “Function Unit” can be further accessed and processed without loss of semantic information. + +**terminal characteristics:** “Terminal Characteristics” represent the complete technical description of an equipment which has to be developed to satisfy any particular CCITT service defined by Study Group 1. This includes the selection of appropriate “Implementation” specifications depending on the “Applications” allowed by the service. Also, “Terminal Characteristics” may specify additional service dependent characteristics to “Applications” and their corresponding “Implementations”. + +# 5 Introduction to the definition of implementation requirements (IRs) + +The Document Application Profiles (DAPs) are described in the T.500-Series Recommendations. The prime purpose of a DAP is to define a set of data streams as a subset of all the data streams allowed by the ODA Standard. This is achieved by constraining the constituents and attribute values that may be contained in the data streams that conform to the DAP. + +For each DAP, there is need to specify the corresponding IRs. These requirements are concerned with the ability of implementations to generate data streams that conform to a DAP and their ability to correctly interpret the information contained in received data streams so that it can be used by the application or presented to a user. + +IRs may be of two types, namely requirements which are application independent and those which are application dependent. + +The application independent requirements are defined in the T.510-Series Recommendations in conjunction with the relevant DAPs. As one given DAP may be used by more than one application, the corresponding DAP IRs defined in the T.510-Series Recommendations will be independent of these applications. This ensures that all implementations based on the same DAP will at least satisfy the requirements expressed by the T.510-Series Recommendations whatever the applications are. + +The application dependent requirements are to be defined in the T.560-Series Recommendations describing the terminal characteristics. + +Implementation independent requirements are specified based on Function Units. A Function Unit is a unit to which a requirement to implementations is specified. A Function Unit is a constraint on data streams, expressed by DAP constituent constraints, their combination or condition on attribute values, etc. + +Requirements classification is specified in clause 6. IRs qualify every Function Unit as “required” or “optional” to be supported, and also provide fall-back methods when necessary. + +# 6 Requirements classification + +## 6.1 Classification + +As stated before, a precise specification of implementation should guarantee the ability of an implementation to generate data streams that conform to a DAP and their ability to correctly interpret the information contained in received data streams so that it can be used by the application or presented to a user. + +Consequently, the following requirements will be addressed: + +- requirements on the **generation** of documents by the implementation; +- requirements on the **reception** of documents by the implementation. + +## 6.2 Requirements on generation + +An implementation may claim to support the generation of a particular FU if it can issue a corresponding constrained ODIF data stream. + +## 6.3 Requirements on reception + +Three different classes of requirements are specified when receiving an ODIF data stream depending on the nature of the manipulation performed by the receiver on the received document: + +- *Retention requirements* + +An implementation may claim to support the retention of a particular FU if the semantics of that FU can be retained by the implementation and can be further accessed and processed locally. That information either can be modified by the end-user (for instance, the line spacing in a character content portion), or remains available after more general editing of the received document (for instance, automatic numbering of the footnotes). + +- *Layout requirements* + +An implementation may claim to support the layout of a particular FU if it can layout the document in accordance with the layout information when specified within the received document for that FU. + +Note 1 – If the received document does not contain any layout related information, the implementation may be able to present the document to the user by performing a local layout process. The actual layout of the document is then a local matter and is not specified by this Recommendation. + +- *Imaging requirements* + +An implementation may claim to support the imaging of a particular FU if it can present the document in a human readable form in accordance with the imaging information specified within the received document for that FU. + +Note 2 – If the received document does not contain any imaging related information, the implementation may be able to present the document to the user by performing a local imaging process. The actual image of the document is then a local matter and is not specified by this Recommendation. + +## **6.4 DAP Minimum Implementation Requirements (DMIR)** + +In order to aid interworking between implementations based on the same DAP but providing different applications, every DAP has a DAP Minimum Implementation Requirement (DMIR). Any implementation supporting a DAP must conform to the corresponding DMIR. The DMIRs are defined implicitly for every DAP in the T.510-Series Recommendations (see Figure 4). + +# **7 Implementation model and actual implementation** + +## **7.1 Implementation model** + +According to the previous clause, an implementation may be viewed as a box containing two modules: generation and reception. The second is itself composed of three sub-modules: retention, layout and imaging. + +A partial implementation may be composed of one or more of these modules or sub-modules. A complete implementation, that is an implementation composed of all the modules and sub-modules, should, at least, satisfy the DMIR of a given DAP, and can make use of an appropriate set of partial implementations. + +## **7.2 Points of control and observation (PCO)** + +In order to specify only requirements that can be observed, and consequently for testing purposes as well, it is necessary to define the possible points of control and observation (PCO). As illustrated in Figure 1, the points of control and observation are: + +- The data stream: input of the reception module and output of the generation module. +- The input and/or output device. + +Therefore, an implementation may be able to demonstrate: + +- The claimed generation support for a particular Function Unit if it can generate the corresponding constrained ODIF data stream. The point of observation will be the data stream. +- The claimed retention support for a particular Function Unit if it can provide a presentation of the document which exhibits that Function Unit. The point of observation will be the output of the I/O device. +- The claimed layout support for a particular Function Unit if it can provide a presentation of the document which exhibits the layout of that Function Unit. The point of observation will be the output of the I/O device. +- The claimed imaging support for a particular Function Unit if it can provide soft or hard copy of the document which exhibits the imaging of that Function Unit. The point of observation will be the output of the I/O device. See Table 1. + +![Diagram of the DAP implementation model showing Generation, Reception (Retention, Layout, Imaging), and connections to Input/output device and Data stream, both leading to PCO.](ebff22fb5dd6f50a90e44dca0f82f285_img.jpg) + +The diagram illustrates the DAP implementation model. A large grey box labeled 'DAP implementation' contains a 'Generation' block and a 'Reception' block. The 'Reception' block is further divided into 'Retention', 'Layout', and 'Imaging' sub-blocks. Arrows indicate data flow from 'Generation' to 'Retention' and from 'Imaging' to the 'Input/output device'. The 'Input/output device' is connected to a 'PCO' (Point of Control/Point of Observation) via a bidirectional arrow. Additionally, a 'Data stream' is shown entering the 'DAP implementation' box from below, connected to another 'PCO' via a bidirectional arrow. The identifier 'T1203770-92/d01' is located in the bottom right corner of the diagram area. + +Diagram of the DAP implementation model showing Generation, Reception (Retention, Layout, Imaging), and connections to Input/output device and Data stream, both leading to PCO. + +FIGURE 1/T.510 +Implementation model + +TABLE 1/T.510 +Location of the PCOs + +| | | PCO | | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------|------------------|----------------------| +| | | Point of control | Point of observation | +| Generation | | I/O device | Data stream | +| R<br>e<br>c<br>e<br>p<br>t<br>i<br>o<br>n | Retention | Data stream | I/O device | +| | Layout | Data stream | I/O device | +| | Imaging | Data stream | I/O device | +| NOTE – Table 1 does not specify the test methods to be used. These test methods should be described in conjunction with the definition of test cases and could imply other actual PCOs than those indicated in the table. | | | | + +## 7.3 Actual implementations + +This subclause shows possible actual implementations with the processes involved and the relationships between the abstract model defined above and these real processes. + +As illustrated in Figure 2, two main types of implementations may be envisaged. + +### 7.3.1 ODA based implementation + +This type of implementation performs the editing, layout and imaging of the document directly from an ODA file which either reflects the received ODIF data stream, or has been totally produced. This type of implementation may be composed of an externalization/internalization process which translates the ASN.1 encoding in an ODA file (e.g. using C primitives, etc.) and editing, layout and imaging processes as defined in the ODA Standard itself. + +### 7.3.2 Non-ODA based implementation + +This type of implementation performs the editing, layout and imaging of a received document after conversion between the ODA format and an internal proprietary format. This type of implementation may be composed of an externalization/internalization process along with a conversion process which converts the Function Unit into the implementation internal format. The editing, layout and imaging processes are local processes which may not be conforming to the corresponding processes defined by the ODA Standard. + +Combinations of these two types of implementations are allowed. For instance, an implementation may use conversion for retention requirements and consequently will use a local editing process to update the document while the layout and imaging requirements are satisfied by the use of direct ODA layout and imaging processes. + +![Diagram illustrating the possible actual implementation of ODA and Non-ODA environments.](b8661c6c54f72ecc7ff6cb05e47b2891_img.jpg) + +The diagram illustrates two parallel processing flows within a single system boundary. On the left, the 'ODA environment' is shown. It starts with an 'ODIF' input from a 'PCO' (Presentation Control Object) circle. This input goes into an 'Ext. Int. Process' block. The output of this block is an 'ODA file'. The 'ODA file' is then processed by three components: 'ODA editing process', 'ODA layout process', and 'ODA Imaging process'. These three processes are grouped together by a dashed oval. The output of the 'ODA Imaging process' is a 'PCO' circle. On the right, the 'Non-ODA environment' is shown. It starts with a 'Conversion Process' block that takes input from the 'ODA file'. The output of the 'Conversion Process' is a 'Non-ODA file'. This file is then processed by three components: 'Editing process', 'Layout process', and 'Imaging process'. These three processes are also grouped together by a dashed oval. The output of the 'Imaging process' is a 'PCO' circle. The entire diagram is labeled with the reference 'T1203780-92/d02' at the bottom right. + +Diagram illustrating the possible actual implementation of ODA and Non-ODA environments. + +FIGURE 2/T.510 +Possible actual implementation + +IRs are not specified for real processes, but for the abstract modules defined in the implementation model. However, the specified requirements will have some impact on actual processes of an implementation which will be used for performing the abstract module. + +For instance, for a non-ODA implementation, three processes (internalization/externalization, conversion and editing processes) will be necessary for performing the abstract “generation” module. Therefore, the requirements which are defined for this module should apply to these relevant real processes. + +# 8 Specification of implementation requirements + +## 8.1 Introduction + +In order to specify IRs, the structure shown in Figure 3 is used, where an FU points to one or several IR classes. Within each IR class, one or several qualifiers apply to the FUs and finally each qualifier may be combined with fall-backs. + +![Figure 3/T.510: Structure of IRs. A flow diagram showing the relationship between Feature, Implementation requirements class, Qualifiers, and Fall-backs.](5a4e62bead259c258d069fd3663ea670_img.jpg) + +``` +graph LR; A[Feature] --> B[Implementation requirements class]; B --> C[Qualifiers]; C --> D[Fall-backs]; +``` + +T1203790-92/d03 + +Figure 3/T.510: Structure of IRs. A flow diagram showing the relationship between Feature, Implementation requirements class, Qualifiers, and Fall-backs. + +FIGURE 3/T.510 +Structure of IRs + +The two main classes that are defined in clause 6 are the *generation* and *reception* classes. Requirements on these classes are described in 8.3 and 8.4, respectively. + +## 8.2 Description of Function Units + +The “Function Units” are DAP constituent constraints, or combination of constraints, that will be used to specify DAP IRs. As stated in clause 4, “Function Units” sometimes correspond exactly to end-user known document processing features. + +Therefore, these FUs will correspond to a combination of attributes to which some conditions apply as illustrated by Figure 5. + +Three levels of FUs have been defined: + +- the 1st level corresponds to FUs which are performed by a single attribute; +- the 2nd level corresponds to FUs which are performed by a simple combination of constituents and attributes; +- the 3rd level corresponds to FUs which are performed by more complex combination of constituents and attributes. + +Each Recommendation of the T.510-Series may specify IRs for the whole set of FUs or may limit the IRs to a limited set of FUs, for example to the 1st and 2nd levels only. + +## 8.3 Requirements for generation + +For that class of requirements, each FU will be qualified by using one of the following: + +- *Mandatory (M)* – This indicates that the implementation must generate the FU in every document. +- *Required (R)* – This indicates that the implementation must have the capability of generating the FU. +- *Optional (O)* – This indicates that the FU is optional and the implementation may or may not have the capability of including this FU in a document. +- *Prohibited (P)* – The implementation shall not offer the capability of supporting the FU. This FU must not appear in the generated data stream. The use of this P-qualifier may depend on conditions. + +The DMIR includes all FUs which are classified either as mandatory or as required. + +## 8.4 Requirements for reception + +For that class of requirements, each FU will be qualified by using one of the following: + +- *Required (R)* – This indicates that the implementation must be capable of processing the FU when that FU is present in the received data stream. +- *Optional (O)* – This indicates that the FU is optional and the implementation may or may not have the capability of processing this FU when it is present in the received data stream. +- *Not Applicable (N/A)* – This indicates that the FU has no impact on the receiving side. + +Additionally, the R and O qualifiers may each be combined with the following: + +- *Fall-back (F)* – This indicates that the implementation may provide a specified fall-back mechanism to process the FU when it is present in the received data stream. + +The DMIR includes all FUs which are classified as required. + +## 8.5 Summary + +Depending on the requirements classes, Figure 4 illustrates the possible qualifiers (or combination of qualifiers) that could apply to the FUs. Thus, four qualifiers may occur for the generation support (M, R, O and P) and four qualifiers may occur for the reception support (R, RF, O and OF). + +![A hierarchical diagram showing the qualifiers for Features (FUs). A 'Feature' box branches into 'IR for Generation' and 'IR for Reception'. 'IR for Generation' branches into 'Mandatory (M)', 'Required (R)', 'Optional (O)', and 'Prohibited (P)'. 'Mandatory (M)' and 'Required (R)' are grouped by a bracket labeled 'DMIR'. 'IR for Reception' branches into 'Required (R)', 'Optional (O)', and 'N/A'. 'Required (R)' further branches into 'Without Fall-back (R)' and 'With Fall-back (RF)'. 'Optional (O)' further branches into 'Without Fall-back (O)' and 'With Fall-back (OF)'. 'Without Fall-back (R)' and 'With Fall-back (RF)' are grouped by a bracket labeled 'DMIR'. The identifier 'T1203800-92/d04' is at the bottom right.](78ffccd66df9bafd96e3e081110d09dd_img.jpg) + +``` +graph LR; Feature[Feature] --> IR_Generation[IR for Generation]; Feature --> IR_Reception[IR for Reception]; IR_Generation --> Mandatory[Mandatory (M)]; IR_Generation --> Required_G[Required (R)]; IR_Generation --> Optional_G[Optional (O)]; IR_Generation --> Prohibited[Prohibited (P)]; Mandatory --- DMIR1[DMIR]; Required_G --- DMIR1; IR_Reception --> Required_R[Required (R)]; IR_Reception --> Optional_R[Optional (O)]; IR_Reception --> N_A[N/A]; Required_R --> Without_FB_R[Without Fall-back (R)]; Required_R --> With_FB_RF[With Fall-back (RF)]; Optional_R --> Without_FB_O[Without Fall-back (O)]; Optional_R --> With_FB_OF[With Fall-back (OF)]; Without_FB_R --- DMIR2[DMIR]; With_FB_RF --- DMIR2; T1203800-92/d04 +``` + +A hierarchical diagram showing the qualifiers for Features (FUs). A 'Feature' box branches into 'IR for Generation' and 'IR for Reception'. 'IR for Generation' branches into 'Mandatory (M)', 'Required (R)', 'Optional (O)', and 'Prohibited (P)'. 'Mandatory (M)' and 'Required (R)' are grouped by a bracket labeled 'DMIR'. 'IR for Reception' branches into 'Required (R)', 'Optional (O)', and 'N/A'. 'Required (R)' further branches into 'Without Fall-back (R)' and 'With Fall-back (RF)'. 'Optional (O)' further branches into 'Without Fall-back (O)' and 'With Fall-back (OF)'. 'Without Fall-back (R)' and 'With Fall-back (RF)' are grouped by a bracket labeled 'DMIR'. The identifier 'T1203800-92/d04' is at the bottom right. + +FIGURE 4/T.510 +Qualifiers applying to FUs + +## 8.6 Tables proforma + +Tables describing IRs should include the list of relevant FUs and should qualify each FU relative to the requirement class to be used. An example of proforma is shown in Figure 5. + +| | | | Generation | Reception | | | | +|----------------|-----------|-----------|------------|-----------|------|------|-----------| +| Function units | | | G | R | L | I | Notes | +| | Attribute | Condition | | | | | | +| 100 | | | XXX | XXX | XXX | XXX | .... .... | +| .... | | | .... | .... | .... | .... | .... .... | +| 1nn | | | | | | | | + +FIGURE 5/T.510 + +### Tables proforma + +# 9 Implementation support statement (ISS) + +## 9.1 Introduction + +The tables of the relevant Recommendations of the T.510-Series containing the IRs may be used for support statements, or as a basis for the developments of these support statements. + +The set of minimum implementation requirements must be supported by the implementation while the implemented options are to be indicated in the ISS. + +## 9.2 Description of implementation + +The supplier, i.e. the entity who wants to state the conformity of its developed implementation, must describe the implementation. This description should include the total system configuration, the portion of the implementation in such configuration and scope of the support of the implementation. + +## 9.3 ISS + +The supplier states whether the implementation (called the *stated implementation* in this subclause) which is defined in the “Description of Implementation” can execute the processes (called the *stated processes* in this subclause) which are also defined in the “Description of Implementation”. + +The ISS shall be provided by the supplier specifying the following qualifiers for each FU. + +### 1) *In the case of a Generator* + +- Y(es) The stated implementation can execute the stated processes for all satisfying data streams. +- P(artial) The stated implementation can execute the stated processes for some satisfying data streams. In this case, the supplier must state the range of data streams that the stated processes can execute. +- N(o) The stated implementation cannot execute, or is not confirmed to execute, the stated processes for satisfying data streams. (It includes the case that the stated implementation can execute the stated processes for some satisfying data streams but the range cannot be described). +- The stated processes do not relate to this Function Unit. + +### 2) *In the case of a Receiver* + +- Y(es)      The stated implementation can execute the stated processes for all satisfying data streams. +- Fall-back is possible if permitted by the Requirement. In this case, the supplier must describe the way of fall-back. +- P(artial)    The stated implementation can execute the stated processes for some satisfying data streams. In this case, the supplier must state the range of data streams that the stated processes can execute. +- Fall-back is possible if permitted. In this case, the supplier must describe the way of fall-back. +- N(o)        The stated implementation cannot execute, or is not confirmed to execute, the stated processes for satisfying data streams. (It includes the case that the stated implementation can execute the stated processes for some satisfying data streams but the range cannot be described or the performed fall-back is not permitted). +- The stated processes do not relate to this Function Unit. + +#### *Range* + +For a particular process, the supplier describes the range of data streams that the stated implementation can execute when the *Support* is “P”. + +#### *Fall-back* + +The supplier describes the way of fall-back that the stated implementation follows, which must be a way permitted by the *Fall-back* description in the IR. + +## 9.4      **Relation to the qualifiers** + +The following relations must be fulfilled when a supplier creates its ISS: + +### 1) *In the case of generation:* + +If the qualifier of the FU is M, then the supplier must fill-in “Y”. + +If the qualifier of the FU is R, then the supplier must fill-in “Y” or “–”. + +If the qualifier of the FU is O, then the supplier must fill-in “Y” or “P” or “N” or “–”. + +If the qualifier of the FU is P, then the supplier must fill in “–”. + +### 2) *In the case of reception:* + +If the qualifier of the FU is R, then the supplier must fill-in “Y” or “–”. + +If the qualifier of the FU is O, then the supplier must fill-in “Y” or “P” or “N” or “–”. + +If the qualifier of the FU is N/A, then the supplier must fill-in “–”. + +## 9.5      **Relation to testing** + +In the case of provision of ISS, the testing device may select the test cases that apply to the implementation under test (IUT). + +![Flowchart showing the process from Document application profile to Implementation requirements, then to ISS, and finally to Test selection.](638091db82245c9dc328387edff215d8_img.jpg) + +``` +graph LR; A[Document application profile] --> B[Implementation requirements]; B --> C[ISS]; C --> D[Test selection] +``` + +Flowchart showing the process from Document application profile to Implementation requirements, then to ISS, and finally to Test selection. + +T1203810-92/d05 + +# **Annex A** (informative) + +# **Relationships between the DAPs, Implementation Requirements and Terminal Characteristics** + +Figure A.1 illustrates the relationships between the various components of the T.500-Series Recommendations. + +At the top of Figure A.1 is represented the set of Recommendations defining Document Application Profiles specifications: T.501, 50x... These Recommendations include the specification of the constituent constraints. + +Each DAP specification refers to DAP implementation requirements which are represented in the middle of the figure: T.511, T.51x... Each T.51x Recommendation is dedicated to one DAP specification and contains, for that DAP, the definition of the function units allowed by the DAP and the minimum requirements (DMIR) for the processes involved: generation, retention, layout and imaging. + +For one given application or service, there is one Recommendation of the T.560-Series which defines Terminal Characteristics by: + +- selecting the DAP specifications which are allowed by this service; +- for each DAP specification, selecting the relevant processes which can be used; +- for each relevant process, specifying additional service dependent requirements that may apply, +- defining the application minimum implementation requirements (AMIR) that all implementations must satisfy whatever the DAP actually used. + +The bottom of the figure represents the actual implementation statement. This corresponds to the actual features which are implemented and is outside the scope of the T.500-Series Recommendations. Indeed, the mapping between the FUs as specified by the DAP specification and the actual features depends on individual implementation and these Recommendations do not provide any guidance for such mapping. However, it can be interesting, mainly for testing purposes, to specify a form identifying all the possible FUs and the corresponding actually implemented features. Such a form could be filled by manufacturers to describe their real implementations. This leads to the definition of a proforma called “Implementation Support Statement” (ISS) which is defined, for every DAP, in the corresponding DAP implementation requirement. Additional service dependent requirements as specified by T.560-Series Recommendations may lead to some extend to this ISS proforma. + +![Diagram illustrating the relationships between DAPs, implementation requirements, and terminal characteristics. The diagram is organized into three main horizontal sections: 'DAPs Specifications' at the top, 'DAPs Implementation requirements' in the middle, and 'Actual implementation' at the bottom. The 'DAPs Specifications' section includes boxes for 'T.501' (containing 'Constituents attributes Constraints' and 'Function Units'), 'T.50x', and 'T.50y'. The 'DAPs Implementation requirements' section includes 'T.511' (containing 'Generation' and 'Reception' sub-sections with 'Retention', 'Layout', and 'Imaging' components), 'T.51x', 'T.51y', and 'T.561' (containing 'Relevant Processes Selection', 'Additional Service Dependent requirements', and 'Communication Protocol Selection'). The 'Actual implementation' section shows 'Editing process', 'Layout process', and 'Imaging process' leading to 'Generation reception'. Arrows indicate references between these components, with a dashed double-headed arrow connecting the 'Actual implementation' section to the 'DAPs Implementation requirements' section. A note at the bottom right states: 'NOTE - The arrows illustrate the actual references made from series to other series.'](5cab96b2d23174c25919840ecd50aa48_img.jpg) + +DAPs Specifications + +T.501 + +Constituents attributes Constraints + +Function Units + +T.50x + +T.50y + +DAPs Implementation requirements + +T.511 + +Generation + +Reception + +Retention + +Layout + +Imaging + +T.51x + +T.51y + +Terminal Characteristics + +T.561 + +Relevant Processes Selection + +Additional Service Dependent requirements + +Communication Protocol Selection + +T.56x + +T.56y + +Actual implementation + +Editing process + +Layout process + +Imaging process + +Generation reception + +NOTE - The arrows illustrate the actual references made from series to other series. + +T1203820-92/d06 + +Diagram illustrating the relationships between DAPs, implementation requirements, and terminal characteristics. The diagram is organized into three main horizontal sections: 'DAPs Specifications' at the top, 'DAPs Implementation requirements' in the middle, and 'Actual implementation' at the bottom. The 'DAPs Specifications' section includes boxes for 'T.501' (containing 'Constituents attributes Constraints' and 'Function Units'), 'T.50x', and 'T.50y'. The 'DAPs Implementation requirements' section includes 'T.511' (containing 'Generation' and 'Reception' sub-sections with 'Retention', 'Layout', and 'Imaging' components), 'T.51x', 'T.51y', and 'T.561' (containing 'Relevant Processes Selection', 'Additional Service Dependent requirements', and 'Communication Protocol Selection'). The 'Actual implementation' section shows 'Editing process', 'Layout process', and 'Imaging process' leading to 'Generation reception'. Arrows indicate references between these components, with a dashed double-headed arrow connecting the 'Actual implementation' section to the 'DAPs Implementation requirements' section. A note at the bottom right states: 'NOTE - The arrows illustrate the actual references made from series to other series.' + +FIGURE A.1/T.510 +Relationships between DAPs, implmentation requirements and terminal characteristics \ No newline at end of file diff --git a/marked/T/T-REC-T.53-199404-I_PDF-E/raw.md b/marked/T/T-REC-T.53-199404-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..62dacf0302f614411d71bbd0a07155730715996a --- /dev/null +++ b/marked/T/T-REC-T.53-199404-I_PDF-E/raw.md @@ -0,0 +1,3175 @@ + + +![ITU logo: a globe with the letters ITU inside, and a lightning bolt passing through it.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, and a lightning bolt passing through it. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## T.53 + +(04/94) + +### TELEMATIC SERVICES + +### TERMINAL EQUIPMENTS AND PROTOCOLS FOR TELEMATIC SERVICES + +--- + +### CHARACTER CODED CONTROL FUNCTIONS FOR TELEMATIC SERVICES + +### ITU-T Recommendation T.53 + +(Previously "CCITT Recommendation") + +--- + +# FOREWORD + +The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). + +ITU-T Recommendation T.53 was prepared by ITU-T Study Group 8 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 7th of April 1994. + +# --- NOTE + +In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +© ITU 1994 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +# CONTENTS + +| | <i>Page</i> | +|-------------------------------------------------------------------------------------------|-------------| +| 1 Scope..... | 1 | +| 1.1 General..... | 1 | +| 1.2 The ITU-T..... | 1 | +| 2 Normative references ..... | 2 | +| 2.1 Identical Recommendations International Standards..... | 2 | +| 2.2 Paired Recommendations International Standards equivalent in technical content..... | 2 | +| 2.3 Additional references..... | 2 | +| 3 Definitions..... | 3 | +| 4 Abbreviations and acronyms..... | 7 | +| 4.1 Abbreviations..... | 7 | +| 4.2 Acronyms..... | 7 | +| 5 Device concepts ..... | 7 | +| 6 Notation and Names..... | 7 | +| 6.1 Notation ..... | 8 | +| 6.2 Names ..... | 8 | +| 7 Code extension techniques ..... | 8 | +| 8 Types of control functions ..... | 8 | +| 8.1 Elements of the C0 set..... | 8 | +| 8.2 Elements of the C1 set..... | 9 | +| 8.3 Control sequences..... | 9 | +| 8.4 Independent control functions ..... | 9 | +| 8.5 Control strings ..... | 9 | +| 8.6 Not an element of any set ..... | 10 | +| 8.7 Notation ..... | 10 | +| 9 Categories of control functions considered in this Recommendation ..... | 10 | +| 10 Concepts relating to text formatting..... | 11 | +| 10.1 Formatted content / page-image format (PIF)..... | 11 | +| 10.2 Processable content..... | 12 | +| 10.3 Formatted processable content (formattable content)..... | 12 | +| 11 Repertoire of control functions ..... | 12 | +| 11.1 Delimiters ..... | 13 | +| 11.2 Device control functions..... | 13 | +| 11.3 Display control functions..... | 14 | +| 11.4 Format effectors..... | 14 | +| 11.5 Information separators ..... | 16 | +| 11.6 Introducers ..... | 16 | +| 11.7 Miscellaneous control functions ..... | 17 | +| 11.8 Presentation control functions ..... | 17 | +| 11.9 Shift functions..... | 19 | +| 11.10 Transmission control functions..... | 20 | +| 12 Definition of control functions..... | 20 | +| 12.1 ACKNOWLEDGE (ACK) ..... | 20 | +| 12.2 AUXILIARY DEVICE OFF (ADF) ..... | 20 | +| 12.3 AUXILIARY DEVICE ON (ADO) ..... | 21 | + +| | <i>Page</i> | +|--------------------------------------------------------------------|-------------| +| 12.4    ACTIVATE IMPLICIT SCROLLING (AIS)..... | 21 | +| 12.5    ACTIVE POSITION ADDRESSING (APA)..... | 21 | +| 12.6    ACTIVE POSITION BACKWARD (APB)..... | 21 | +| 12.7    ACTIVE POSITION DOWN (APD) ..... | 21 | +| 12.8    ACTIVE POSITION FORWARD (APF)..... | 21 | +| 12.9    ACTIVE POSITION HOME (APH) ..... | 22 | +| 12.10   ACTIVE POSITION RETURN (APR) ..... | 22 | +| 12.11   ACTIVE POSITION SET (APS) ..... | 22 | +| 12.12   ACTIVE POSITION UP (APU)..... | 22 | +| 12.13   BELL (BEL) ..... | 22 | +| 12.14   BREAK PERMITTED HERE (BPH)..... | 22 | +| 12.15   BACKSPACE (BS) ..... | 23 | +| 12.16   CANCEL (CAN) ..... | 23 | +| 12.17   CURSOR OFF (COF) (used only in Recommendation T.101) ..... | 23 | +| 12.18   CURSOR ON (CON) (used only in Recommendation T.101)..... | 23 | +| 12.19   CARRIAGE RETURN (CR) ..... | 23 | +| 12.20   CLEAR SCREEN (CS) ..... | 24 | +| 12.21   CONTROL SEQUENCE INTRODUCER (CSI) ..... | 24 | +| 12.22   DEVICE CONTROL ONE (DC1) ..... | 24 | +| 12.23   DEVICE CONTROL TWO (DC2)..... | 25 | +| 12.24   DEVICE CONTROL THREE (DC3)..... | 25 | +| 12.25   DEVICE CONTROL FOUR (DC4) ..... | 25 | +| 12.26   DISPLAY DEVICE OFF (DDF) ..... | 25 | +| 12.27   DISPLAY DEVICE ON (DDO)..... | 25 | +| 12.28   DELETE (DEL)..... | 25 | +| 12.29   DEACTIVATE IMPLICIT SCROLLING (DIS) ..... | 26 | +| 12.30   DATA LINK ESCAPE (DLE) ..... | 26 | +| 12.31   EMPTY BUFFER (EBU) ..... | 26 | +| 12.32   EXTENDED DEVICE CONTROL ONE (EDC1) ..... | 26 | +| 12.33   EXTENDED DEVICE CONTROL TWO (EDC2) ..... | 26 | +| 12.34   EXTENDED DEVICE CONTROL THREE (EDC3) ..... | 26 | +| 12.35   EXTENDED DEVICE CONTROL FOUR (EDC4) ..... | 26 | +| 12.36   ENQUIRY (ENQ) ..... | 27 | +| 12.37   END OF TRANSMISSION (EOT) ..... | 27 | +| 12.38   ESCAPE (ESC) ..... | 27 | +| 12.39   END OF TRANSMISSION BLOCK (ETB)..... | 27 | +| 12.40   END OF TEXT (ETX) ..... | 27 | +| 12.41   FORM FEED (FF)..... | 27 | +| 12.42   FONT SELECTION (FNT)..... | 28 | +| 12.43   GRAPHIC CHARACTER COMBINATION (GCC) ..... | 28 | +| 12.44   GRAPHIC SIZE MODIFICATION (GSM)..... | 28 | +| 12.45   GRAPHIC SIZE SELECTION (GSS)..... | 29 | +| 12.46   HARD COPY START (HCS) ..... | 29 | +| 12.47   HARD COPY STOP (HCT)..... | 29 | + +| | <i>Page</i> | +|----------------------------------------------------------------------|-------------| +| 12.48 HARD COPY WAIT (HCW) ..... | 29 | +| 12.49 CHARACTER POSITION BACKWARD (HPB) ..... | 30 | +| 12.50 CHARACTER POSITION FORWARD (HPR)..... | 30 | +| 12.51 CHARACTER TABULATION (HT) ..... | 30 | +| 12.52 IDENTIFY GRAPHIC SUBREPERTOIRE (IGS) ..... | 30 | +| 12.53 INFORMATION SEPARATOR ONE (US - UNIT SEPARATOR) (IS1) ..... | 31 | +| 12.54 INFORMATION SEPARATOR TWO (IS2) – RECORD SEPARATOR) (RS)..... | 31 | +| 12.55 INFORMATION SEPARATOR THREE (IS3) [GROUP SEPARATOR (GS)] ..... | 31 | +| 12.56 INFORMATION SEPARATOR FOUR (IS4) [FILE SEPARATOR (FS)] ..... | 31 | + +# **SUMMARY** + +This Recommendation defines the character coded control functions and their coded representation for use in 7-bit and 8-bit coded ITU-T Telematic services and related to the text communication part of the Telematic services. + +The control functions contained in this Recommendation define the basic meanings which may be common in some (or all) of the Telematic services. The definitions of the control functions are aligned to those in ISO/IEC 6429 and ISO/IEC 10538 where possible with the exception of some specific functions defined by particular services. + +This Recommendation specifies control functions to handle bi-directional texts in character-imaging devices. The bi-directional concept is an addition to the uni-directional device concept which was the base for the former ITU-T Recommendations | ISO standards. It means that the control functions which were modified to meet the bi-directional requirements can be used for uni-directional devices, as before. + +# **CHARACTER CODED CONTROL FUNCTIONS FOR TELEMATIC SERVICES** + +*(Geneva, 1994)* + +# **1 Scope** + +## **1.1 General** + +This Recommendation defines the character coded control functions and their coded representation for use in 7-bit and 8-bit codes, in use by ITU-T Telematic services. + +The control functions contained in this Recommendation define the basic meanings which may be common in some (or all) of the Telematic services. The definitions of the control functions are aligned to those in ISO/IEC 6429 and ISO/IEC 10538 where possible with the exception of some specific functions defined by particular services for their use. Where the control function definitions differ between those in particular existing Telematic services on the one hand, and those in this Recommendation on the other hand, then the definitions in the particular Telematic services should take precedence. For future development, Telematic services should use the control functions defined in this Recommendation. + +This Recommendation specifies control functions to handle bi-directional texts in character-imaging devices. The bi-directional concept is an addition to the uni-directional device concept which was the base for the former ITU-T Recommendations | ISO Standards. That means that the control functions which were modified to meet the bi-directional requirements can be used for uni-directional devices, as before. + +## **1.2 The ITU-T** + +*considering* + +- (a) the increasing interdependence of the various ITU-T character sets and coding schemes in various Telematic services; +- (b) the introduction of new facilities such as code conversion and interworking between various Telematic services; +- (c) the advantage of having relevant control functions and coding schemes compiled in one Recommendation; +- (d) that Recommendation T.50 specifies the International Reference Version (IRV) of the 7-bit coded character set; +- (e) that Recommendations T.51 and T.52 define the Latin based, respectively the non-Latin based, coded character sets for Telematic services; +- (f) that Recommendation T.51 defines the code extension mechanisms used in Telematic services; +- (g) that Recommendations T.61 and T.101 define the character coding systems for Teletex and Videotex; +- (h) that Recommendation T.416 defines the character content architecture in Open Document Architecture (ODA) environments, +- (i) that Annex D/T.4 defines an optional character mode of group 3 facsimile apparatus, + +*provides* the following Recommendation as a reference document, from which control functions should be derived for individual Telematic services. + +**1.3** This Recommendation specifies the character coded control functions related to the text communication part of Telematic services. + +**1.4** This Recommendation is open-ended, additional control functions being subject to further inclusion as the need for such is identified for one or more Telematic services. + +# **2 Normative references** + +The following ITU-T Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain lists of currently valid International Standards. The TSB maintains a list of currently valid ITU-T Recommendations. + +## **2.1 Identical Recommendations | International Standards** + +None. + +## **2.2 Paired Recommendations | International Standards equivalent in technical content** + +- CCITT Recommendation T.50 (1992), *International Reference Alphabet*. +ISO/IEC 646:1991, *Information technology – ISO 7-bit coded character set for information technology*. +- CCITT Recommendation T.51 (1992), *Latin based coded character sets for Telematic services*. +ISO/DIS 6937:1991, *Information technology – Coded graphic character set for the communication of texts using the Latin alphabet*. +- CCITT Recommendation T.416 (1988) | ISO 8613-6:1988, *Open document architecture (ODA) and interchange format – Character content architecture*. + +## **2.3 Additional references** + +- CCITT Recommendation T.4 (1992), *Standardization of Group 3 Facsimile Apparatus for Document Transmission, Annex D – Optional Character Mode of Group 3*. +- ITU-T Recommendation T.52 (1993), *Non-Latin coded character sets for Telematic services*. +- ITU-T Recommendation T.61 (1993), *Character repertoire and coded character sets for the international Teletex service*. +- ITU-T Recommendation T.101 (1993), *International interworking for Videotex services*. +- ISO 1745:1975, *Information processing – Basic mode control procedures for data communication systems*. +- ISO 2022:1986, *Information processing – ISO 7-bit and 8-bit coded character sets – Code extension techniques* (under revision). +- ISO 2375:1985, *Data processing – Procedure for registration of escape sequences*. +- ISO/IEC 6429:1992, *Information processing – Control functions for 7-bit and 8-bit coded character sets*. +- ISO/IEC 7350:1991, *Information technology – Registration of repertoires of graphic characters from ISO/IEC 10367*. + +- ISO/IEC 10367:1991, *Information technology – Standardized coded graphic character sets for use in 8-bit codes*. +- ISO/IEC 10538:1991, *Information technology – Control functions for text communication*. +- Standard ECMA-48, *Control functions for coded character sets*, June 1991. +- ECMA TR/53, *Handling of bi-directional texts*, June 1992. +- ISO/IEC JTC 1/SC 2 WG 3 N2122 – *Guidelines for generating and presenting unique names of the characters in SC 2 Standards*, December 1990. + +# 3 Definitions + +The definitions in this Recommendation assume a bi-directional device model which has both a presentation component and a data component. In the case of a uni-directional device or a bi-directional device without a data component (only with presentation component), all references to active data position, data component, character progression, etc., are to be read as referring to active presentation position, presentation component, character path, etc., respectively. + +The model of handling bi-directional text according to ECMA TR/53 is described in Annex B. + +**3.1 active data position:** In the data component the character position which is to receive the next graphic character or the next control function from the data stream and relative to which certain control functions are to be executed. + +**3.2 active line:** The line in the data component is the line which contains the active data position. + +The line in the presentation component is the line which contains the active presentation position. + +**3.3 active page:** The page in the data component is the page which contains the active data position. + +The page in the presentation component the page which contains the active presentation position. + +**3.4 active position:** The character position which is to image the graphic symbol representing the next graphic character or relative which the next control function is to be executed. + +NOTE – In general, the active position is indicated in a display by a cursor. + +**3.5 active presentation position:** In the presentation component the character position which is to receive the next graphic character for graphic image output and relative to which certain control functions are to be executed. + +NOTE – In general, the active presentation position is indicated in a display by a cursor. + +**3.6 auxiliary device:** A device connected to a character-imaging device for the purpose of inputting, storing, retrieving, or imaging data. + +**3.7 bi-directional data:** Data containing text strings which are to be presented in different writing directions, like left-to-right and right-to-left. + +**3.8 bit combination:** An ordered set of bits used for the representation of characters. + +**3.9 byte:** A bit string that is operated upon as a unit. + +**3.10 to cancel:** To mark data in such a way that it can be ignored in subsequent processing. + +**3.11 character:** A member of a set of elements used for the organization, control or representation of data. + +**3.12 character-imaging device:** A device that gives a visual representation of data in the form of graphic symbols using any technology, for example cathode ray tube or printer. + +**3.13 character path:** The sequential order of the character positions along a line of the presentation component. + +**3.14 character position:** The portion of a display that is imaging or is capable of imaging a graphic symbol. + +In the data component a position available for receiving graphic characters for further presentation processing. + +In the presentation component a position available for receiving graphic characters for the rendering of the graphic image output. + +**3.15 character progression:** The sequential order of the character positions along a line of the data component. + +**3.16 to clear:** To remove the display of data or the information used for the display of data, for example tabulation stops marking the boundaries between fields. + +**3.17 code extension:** The techniques for the encoding of characters that are not included in the character set of a given code. + +**3.18 code table:** A table showing the character allocated to each bit combination in a code. + +**3.19 coded-character-data-element (ICC-data-element):** An element of interchanged information that is specified to consist of a sequence of coded representations of characters, in accordance with one or more identified standards for coded character sets. + +### NOTES + +1 In a communication environment according to the reference model for Open Systems Interconnection of CCITT Rec. X.200 | ISO 7498, a CC-data-element will form all or part of the information that corresponds to the Presentation-Protocol-Data-Units (PPDU) defined in those specifications. + +2 When information interchange is accomplished by means of interchangeable media, a CC-data-element will form all or part of the information that corresponds to the user data, and not that recorded during formatting and initialization. + +**3.20 coded character set; code:** A set of unambiguous rules that establishes a character set and the one-to-one relationship between the characters of the set and their bit combination. + +**3.21 control character:** A control function, the coded representation of which consists of a single bit combination. + +**3.22 control function:** An action that affects the recording, processing, transmission, or interpretation of data that has a coded representation consisting of one or more bit combinations. + +**3.23 control sequence:** A string of bit combinations starting with that representing the control character CONTROL SEQUENCE INTRODUCER (CSI), used for the coded representation of control functions with or without parameters. + +**3.24 control string:** A string of bit combinations which may occur in the data stream as a logical entity for control purposes. + +**3.25 cursor:** A special indicator used in a display to mark the active presentation position. + +**3.26 data component:** The device component which is used for storing the received data for further presentation processing. + +**3.27 default:** A value or a state that is to be assumed when no value or state is explicitly specified. + +**3.28 to delete:** To remove the contents from character positions and closing the resulting gap by moving adjacent graphic characters into the empty positions. + +**3.29 to designate:** To identify a set of characters that are to be represented, in some cases immediately and in others on the occurrence of a further control function, in a prescribed manner. + +**3.30 device:** A component of information processing equipment which can transmit, and/or receive, coded information within coded-character-data-elements. + +NOTE – It may be an input/output device in the conventional sense, or a process such as an application program or gateway function. + +**3.31 dynamically redefinable character set (DRCS):** A graphic character set containing definable characters whose pattern can be downloaded from the host. + +**3.32 environment:** The characteristic that identifies the number of bits used for representing a character in a data processing or data communication system or in part of such a system. + +**3.33 to erase:** To remove the contents from character positions and leaving the resulting gap open. + +**3.34 escape sequence:** A string of bit combinations that is used for control purposes in code extension procedures. The first of these bit combinations represents the character ESCAPE. + +## **3.35 Explicit movement** + +See B.3.3.2. + +**3.36 field:** An area consisting of the character position at a character tabulation stop (beginning of the field) and the character positions up to, but not including, the character position at the following character tabulation stop (end of the field). + +**3.37 Final Byte:** The bit combination that terminates an escape sequence or a control sequence. + +NOTE – In some specifications appears the term Final Character, with the same meaning. + +**3.38 formator function:** A control function (format effector or presentation control function) describing how the originator of the data stream wishes the information to be formatted or presented. + +**3.39 formatted form:** A form of representation of a document that allows the presentation of the document as intended by the originator and does not support editing and (re)formatting (also mentioned as final form). + +NOTE – See also page-image format (PIF). + +**3.40 formatted processable form (formattable form):** A form of representation of a document that allows the presentation of the document as intended by the originator and also supports editing and (re)formatting. For example, Recommendation T.416 defines such a form. + +**3.41 graphic character:** A character, other than a control function, that has a visual representation normally handwritten, printed or displayed, and that has a coded representation consisting of one or more bit combinations. + +**3.42 graphic rendition:** The visual style of displaying a set of graphic symbols. + +**3.43 graphic symbol:** A visual representation of a graphic character or of a control function. + +## **3.44 Implicit movement** + +See Annex B.3.3.1. + +## **3.45 Indirect movement** + +See Annex B.3.3.3. + +## **3.46 Intermediate byte:** + +- a) In an escape sequence, a bit combination that may occur between the control function ESCAPE (ESC) and the Final Byte. +- b) In a control sequence, a bit combination that may occur between the control function CONTROL SEQUENCE INTRODUCER (CSI) and the Final Byte, or between a Parameter Byte and the Final Byte. + +NOTE – In some specifications the term Intermediate Character appears with the same meaning. + +**3.47 to invoke:** To cause a designated set of characters to be represented by the prescribed bit combinations whenever those bit combinations occur. + +**3.48 line:** A set of consecutive character positions. + +**3.49 line home position:** A reference position on a line in the data component ahead of which the active data position can normally not be moved. + +A reference position on a line in the presentation component ahead of which the active presentation position can normally not be moved. + +**3.50 line limit position:** A reference position on a line in the data component beyond of which the active data position can normally not be moved. + +A reference position on a line in the presentation component beyond of which the active presentation position can normally not be moved. + +**3.51 line orientation:** The term used to describe the way in which a line will appear in the graphic image output. In this Recommendation line orientation may only be horizontal or vertical. + +**3.52 line progression:** The direction of presentation of successive lines. + +**3.53 nesting level:** The number of ancestors between given substring and the string with no parent. + +**3.54 page:** A set of consecutive lines. + +**3.55 page home position:** A reference position on a page in the data component ahead of which the active line (the line that contains the active data position) can normally not be moved. + +A reference position on a page in the presentation component ahead of which the active line (the line that contains the active presentation position) can normally not be moved. + +**3.56 page limit position:** A reference position on a page in the data component beyond which the active line (the line that contains the active data position) can normally not be moved. + +A reference position on a page in the presentation component beyond which the active line (the line that contains the active presentation position) can normally not be moved. + +**3.57 page-image format (PIF):** A representation of the image of text which is formatted by the sender for presentation by the recipient and which is not intended to be subjected to reformatting operations by the recipient. + +NOTE – Same as “formatted form”. Recommendations T.61 and T.101 (also ISO/IEC 10538) use this term. + +**3.58 Parameter Byte:** In a control sequence, a bit combination that may occur between the control function CONTROL SEQUENCE INTRODUCER (CSI) and the Final Byte, or between CSI and an Intermediate Byte. + +NOTE – In some specifications appears the term Parameter Character, with the same meaning. + +**3.59 presentation component:** The device component which is used for producing the graphic image output. + +**3.60 repertoire:** A specified set of characters that are represented by one or more bit combinations of a coded character set. + +**3.61 scroll:** The action whereby all, or part of, the graphic symbols of a display are moved in a specified direction. + +**3.62 substring:** A string which is nested within another string. + +**3.63 tabulation:** The technique of identifying character positions or lines in a display for the purpose of arranging information systematically. + +**3.64 tabulation stop:** The indication that a character position or a line is to be used for tabulation; a character tabulation stop may also serve as a boundary between fields. + +- 3.65 text area:** The image of that part of a page on which text may be presented. +- 3.66 uni-directional text:** Data containing text strings which are to be presented in a single writing direction. + +# **4 Abbreviations and acronyms** + +## **4.1 Abbreviations** + +For the purposes of this Recommendation, the following abbreviations apply: + +| | | +|---------|---------------------------------------------------------------------------------------------------------| +| CCITT | International Telegraph and Telephone Consultative Committee<br>(replaced with ITU-T from 1 March 1993) | +| ECMA | European Computer Manufacturers Association | +| IEC | International Electrotechnical Commission | +| ISO | International Organization for Standardization | +| ITU | International Telecommunication Union | +| ITU-T | ITU Telecommunication Standardization Sector (formerly the CCITT) | +| ITU-TSB | ITU Telecommunication Sector Bureau (formerly the Secretariat of the CCITT) | + +## **4.2 Acronyms** + +See Annex D. + +# **5 Device concepts** + +The definitions of the control functions in this Recommendation are based on general assumptions about the architecture of a character-imaging device. Examples of devices conforming to these concepts are: an alphanumeric display device, a printer or a microfilm output device. + +A character-imaging device is a device capable of receiving a data stream that consists of coded control functions and graphic characters, and is capable of producing graphic image output. Such output must be readable by a human being according to the various traditional writing conventions such as left-to-right, right-to-left, top-to-bottom and bottom-to-top. The graphic image output is, in general, produced in the form of one or more rectangular arrays of character positions and lines which are called pages. + +If the device is an input/output device rather than merely an output device, it is also capable of transmitting a data stream that consists of coded control functions and graphic characters; the transmitted data stream is, in general, composed of a combination of data which have been sent to the device and data which have been entered locally into the device, for example by an associated keyboard. + +A number of facilities for the organization of the graphic image output and for establishing the direction of presented text are provided by this Recommendation. A device may support all of these facilities or only a subset of them appropriate to the application. + +The definitions in this Recommendation assume a bi-directional device which has both a presentation component and a data component. + +In the case of a uni-directional device or a bi-directional device without a data component, all references to active data position, data component, character progression, etc., are to be read as referring to active presentation position, presentation component, character path, etc., respectively. The bi-directional device model is described in Annex B. + +# **6 Notation and Names** + +The 7-bit and 8-bit code notation and naming rules are described in detail in Recommendation T.52. + +## 6.1 Notation + +This Recommendation uses the notation of the form xx/yy, where xx represents the column number 00 to 07 in a 7-bit code table or 00 to 15 in an 8-bit code table and yy represents the row number 00 to 15 (see Table 6-1). + +TABLE 6-1/T.53 + +Row and column allocation in 7-bit and 8-bit environment + +| | | | | | | | | | +|-----------------------------------------|----------------|----------------|----------------|----------------|----------------|----------------|----------------|----------------| +| Bits of an 8-bit code | b <sub>8</sub> | b <sub>7</sub> | b <sub>6</sub> | b <sub>5</sub> | b <sub>4</sub> | b <sub>3</sub> | b <sub>2</sub> | b <sub>1</sub> | +| Bits of a 7-bit code | – | b <sub>7</sub> | b <sub>6</sub> | b <sub>5</sub> | b <sub>4</sub> | b <sub>3</sub> | b <sub>2</sub> | b <sub>1</sub> | +| Bit weight for column and row reference | 2 <sup>3</sup> | 2 <sup>2</sup> | 2 <sup>1</sup> | 2 <sup>0</sup> | 2 <sup>3</sup> | 2 <sup>2</sup> | 2 <sup>1</sup> | 2 <sup>0</sup> | +| Column (xx) | | | | | Row (yy) | | | | + +## 6.2 Names + +This Recommendation assigns at least one name and specifies an acronym for each control function. By convention, only capital letters and hyphen are used for writing the names of graphic characters and control functions. For acronyms only capital letters and digits are allowed. The acronym should be retained in all translations of the text. + +# 7 Code extension techniques + +The code extension techniques applicable to the ITU-T Telematic services are described in Recommendation T.51 and are based on ISO 2022. + +# 8 Types of control functions + +Each control function defined in this Recommendation belongs to one of the following types: + +- elements of the C0 set; +- elements of the C1 set; +- control sequences; +- independent control functions; +- control strings; +- not an element of any set. + +## 8.1 Elements of the C0 set + +These control functions are represented in 7-bit and 8-bit codes by bit combinations from 00/00 to 01/15. + +The definitions and the coded representations of the control functions are specified in clause 12. + +NOTE – It is assumed that even with no invoked C0 set the control character ESCAPE is available and is represented by bit combination 01/11. + +The registered C0 sets for different Telematic services and their invocation escape sequences are listed in Annex A. + +## 8.2 Elements of the C1 set + +These control functions are represented: + +- a) in a 7-bit code by 2-byte escape sequences of the form ESC Fe, where ESC is represented by bit combination 01/11 and Final Byte Fe is represented by a bit combination from 04/00 to 05/15; +- b) in an 8-bit code by bit combinations from 08/00 to 09/15; however, when the announcer sequence ESC 02/00 04/06 according to ISO 2022 is used, the control functions of the C1 set are represented by ESC Fe sequences as in a 7-bit code. + +The definitions and the coded representations of the control functions are specified in clause 12. + +The unallocated bit combinations are reserved for future standardization and shall not be used. + +The registered C1 sets for different Telematic services and their invocation escape sequences are listed in Annex A. + +## 8.3 Control sequences + +A control sequence consists of a sequence of bit combinations starting with that representing the control character CONTROL SEQUENCE INTRODUCER (CSI) followed by one or more bit combinations representing parameters, if any, and by one or more bit combinations identifying the control function. The control character CSI itself is an element of the C1 set. + +The format of a control sequence is: + +CSI P<sub>1</sub>...P<sub>n</sub> I<sub>1</sub>...I<sub>n</sub> F + +where: + +- a) CSI is represented by bit combination 01/11 (representing ESC) and 05/11 in a 7-bit code or by bit combination 09/11 in an 8-bit code; +- b) P<sub>1</sub>...P<sub>n</sub> are Parameter Bytes, which, if present, consist of bit combinations from 03/00 to 03/15. The parameter representation, the format of the parameter string, and the types of parameters are specified in ISO/IEC 6429; +- c) I<sub>1</sub>...I<sub>n</sub> are Intermediate Bytes, which if present, consist of bit combinations from 02/00 to 02/15. Together with the Final Byte F, they identify the control function; +- d) F is the Final Byte; it consists of a bit combination from 04/00 to 07/14; it terminates the control sequence and together with the Intermediate Bytes, if present, identifies the control function. + +## 8.4 Independent control functions + +These control functions are represented in 7-bit and 8-bit codes by two-character ESCAPE sequences of the form ESC Fs, where ESC is represented by bit combination 01/11 and Fs is represented by bit combination from 06/00 to 07/14. + +## 8.5 Control strings + +A control string is a string of bit combinations which may occur in the data stream as a logical entity for control purposes. A control string consists of an opening delimiter, a command string or a character string, and a terminating delimiter, the STRING TERMINATOR (ST). + +The opening delimiter defined in this Recommendation is START OF STRING (SOS). + +A command string is a sequence of bit combinations in the range 00/08 to 00/13 and 02/00 to 07/14. + +A character string is a sequence of any bit combinations, except those representing SOS or ST. + +The interpretation of the command string or the character string is not defined by this Recommendation, but instead requires prior agreement between the sender and the recipient of the data. + +NOTE – Control strings are used in CCITT Rec. T.416 | ISO 8613-6. + +## 8.6 Not an element of any set + +Some Telematic services still make use of the characters SPACE (SP) and DELETE (DEL) which do not belong to any type. The character SPACE is now definitely defined as a graphic character in ISO and the character DELETE is not a control function in the strict sense, both being removed from ISO/IEC 6429. The use of them as control functions is deprecated. New services shall not implement them, other control functions being available with same functionality. + +## 8.7 Notation + +| Notation | Description | +|------------|-----------------------------------------------------------------| +| (Cx) | Not an element of any set | +| (C0) | Element of the C0 set | +| (C1) | Element of the C1 set | +| (NP) | Control sequence with no parameter | +| (Pn) | Control sequence with a single numeric parameter | +| (Pn1; Pn2) | Control sequence with two numeric parameters | +| (Pn...) | Control sequence with any number of numeric parameters | +| (Ps) | Control sequence with a single selective parameter | +| (Ps1; Ps2) | Control sequence with two selective parameters | +| (Ps...) | Control sequence with any number of selective parameters | +| (Fs) | Independent control function, represented by an ESC Fs sequence | + +# 9 Categories of control functions considered in this Recommendation + +The control functions described in this Recommendation belong in all or some of the following categories: + +## a) *Delimiters* + +which are used to delimit graphic characters and/or shared control functions introduced as a result of a formatting process. + +## b) *Device control functions* + +which control local or remote devices or ancillary devices connected to a data processing or data communication system. + +## c) *Display control functions* + +which control the attributes of the display. + +## d) *Format effectors* + +which cause the active presentation position/cursor to be moved within the text area of a page, and from page to page. + +## e) *Information separators* + +which are application dependent and control separation of unit, record, group and files. + +- f) *Introducers* +which specify controls such as ESC and CSI used to introduce other control functions. +- g) *Miscellaneous control functions* +which do not fit in any of the preceding categories. +- h) *Presentation control functions* +which specify presentation attributes, that is, ways in which subsequent text is to be presented. Examples of presentation attributes are page format, character rendition and tabulation. +- i) *Shift functions* +which are mainly used in code extension techniques conforming to ISO 2022. +- j) *Transmission control functions* +which are intended to control or facilitate transmission of information over telecommunication networks. + +# 10 Concepts relating to text formatting + +## 10.1 Formatted content / page-image format (PIF) + +Formatted content is content for which all the necessary information relating to the layout and imaging of that content has been specified. Content in this form is intended to be imaged as specified and is not intended to be revised by an editing process or to be reformatted. + +The content of a basic component conforming to a formatted character content architecture consists of one or more lines of characters. Each pair of successive lines is separated by a hard line terminator. The last (or only) line may or may not be terminated by a hard line terminator; the end of the content of a basic component implicitly terminates the last line. + +NOTE – Control functions used in formatted content (but not in processable content), as per CCITT Rec. T.416 | ISO 8613-6, are: BS, HPB, HPR, JFY, SACS, SRCS, SSW. + +The communication or interchange of formatted text (page-image format) form implies the transfer of a stream of bit combinations representing graphic characters in the order in which they appear on the pages of the documents, starting with the first character in the first line of the text area of the first page of the first document, and proceeding character by character, line by line and page by page until the end of the last document. + +Embedded in the data stream, there may be coded representations of control functions for various purposes, including the following: + +- a) to specify the size and the orientation of a page, and the size and the position of the text area on a page; +- b) to specify the location of the next graphic character, if that location is other than at the character position following the one at which the previous graphic character on the same line was presented; +- c) to specify the rendition aspects of graphic characters, such as character style and character emphasis, and the character spacing and the line spacing; +- d) to mark the end of a page or the end of a document. + +The interpretation of the control functions and of the coded representations of the graphic characters are unambiguous only if + +- the sequence of the text is followed as specified above; +- no graphic character is located outside the text area; +- no more than one graphic character is located in any one character position on the page, unless a provision for the superimposition of characters forms part of the coding method for the graphic characters of the repertoire in use. + +NOTE – The page-image format is implemented by Telematic services like Teletex and Videotex. + +## 10.2 Processable content + +Processable content is a content which has not been laid out. Content in this form is suitable for revision by an implementation-dependent editing process. In order to image content in this form, it is necessary to apply a content layout process to the content, which converts the processable content into formatted content, or into formatted processable content. + +The content of a basic component conforming to a processable character content architecture consists of one or more sequences of characters. Each pair of successive character sequences is separated by a hard line terminator control function. The last (or only) character sequence may or may not be terminated by a hard line terminator. If the hard line terminator is omitted at the end of the content of a basic logical component to which another basic logical component is concatenated, then the last character sequence continues into the content of the next basic logical component. In all other cases, the end of the content of the basic logical component implicitly terminates the last character sequence. + +The division into character sequences represents the internal structure of the processable content of a basic logical component. Each character sequence is anonymous, in that no name or identifier is associated with it, and no relationship exists among character sequences except that of sequence. + +NOTE – Control functions used in processable content (but not in formatted content), as per CCITT Rec. T.416 | ISO 8613-6, are: BPH, PTX. + +## 10.3 Formatted processable content (formattable content) + +Formatted processable content is content that is structured such that it contains both the formatted content and the processable content as subsets. It is identical in structure to the processable content, except that it may contain additional control functions and graphic characters that have been added as a result of the content layout process. It is identical in structure to the formatted content, except that it may contain logical control functions and delimiters. + +Formatted processable content can be converted to processable content by deleting (or ignoring) all layout control functions, all occurrences of the delimiters and all control functions and characters within those delimiters. This conversion is reversible. + +Formatted processable content can be converted to formatted content by deleting (or ignoring) all logical control functions and the delimiters but retaining the control functions and characters within the delimiters. This conversion is irreversible. + +Soft line terminators are used as separators between lines within a character sequence. + +### NOTES + +1 The formatted and formattable contents are implemented by the Open Document Architecture (ODA) as described in CCITT Rec. T.416 | ISO 8613-6. + +2 Control functions used in formatted processable (formattable) content are all those specified by CCITT Rec. T.416 | ISO 8613-6 for formatted content and for processable content together. + +# 11 Repertoire of control functions + +The control functions defined in this Recommendation are grouped according to their main use. The grouping is intended to aid in understanding the Recommendation and does not restrict the use of the control functions to the indicated categories. + +Under each group, the control functions are presented depending in which Telematic services they are implemented: + +- “common” control functions – Those defined identically by at least the Teletex and Videotex services and in line with the definitions in this Recommendation. +- Videotex specific control functions (as in Recommendation T.101). +- Teletex specific control functions (as in Recommendation T.61). +- Facsimile specific control functions (as in Annex D/T.4). +- ODA specific control functions (as in Rec. T.416 | ISO 8613-6). + +Further Telematic services implementing character coded control functions will be added in the future to this list. + +## 11.1 Delimiters + +| Acronym | Notation | Coded representation | Name | Defined in | +|--------------------|----------|------------------------------------|-------------------|------------| +| <b>ODA (T.416)</b> | | | | | +| SOS | (C1) | ESC 05/08 (7-bit)<br>09/08 (8-bit) | START OF STRING | 12.103 | +| ST | (C1) | ESC 05/12 (7-bit)<br>09/12 (8-bit) | STRING TERMINATOR | 12.109 | + +## 11.2 Device control functions + +| Acronym | Notation | Coded representation | Name | Defined in | +|-------------------------|----------|------------------------------------|-------------------------------|------------| +| <b>Videotex (T.101)</b> | | | | | +| ADF | (C0) | ESC 03/15 | AUXILIARY DEVICE OFF | 12.2 | +| ADO | (C0) | ESC 03/14 | AUXILIARY DEVICE ON | 12.3 | +| COF | (C0) | 01/04 | CURSOR OFF | 12.17 | +| CON | (C0) | 01/01 | CURSON ON | 12.18 | +| DC1 | (C0) | 01/01 | DEVICE CONTROL ONE | 12.22 | +| DC2 | (C0) | 01/02 | DEVICE CONTROL TWO | 12.23 | +| DC3 | (C0) | 01/03 | DEVICE CONTROL THREE | 12.24 | +| DC4 | (C0) | 01/04 | DEVICE CONTROL FOUR | 12.25 | +| DDF | (C1) | ESC 03/13 | DISPLAY DEVICE OFF | 12.26 | +| DDO | (C1) | ESC 03/12 | DISPLAY DEVICE ON | 12.27 | +| EBU | (C1) | ESC 03/11 | EMPTY BUFFER | 12.31 | +| EDC1 | (C1) | ESC 05/01 (7-bit)<br>09/01 (8-bit) | EXTENDED DEVICE CONTROL ONE | 12.32 | +| EDC2 | (C1) | ESC 05/02 (7-bit)<br>09/02 (8-bit) | EXTENDED DEVICE CONTROL TWO | 12.33 | +| EDC3 | (C1) | ESC 05/03 (7-bit)<br>09/03 (8-bit) | EXTENDED DEVICE CONTROL THREE | 12.34 | +| EDC4 | (C1) | ESC 05/04 (7-bit)<br>09/04 (8-bit) | EXTENDED DEVICE CONTROL FOUR | 12.35 | +| HCS | (C1) | ESC 03/09 | HARD COPY START | 12.46 | +| HCT | (C1) | ESC 03/10 | HARD COPY STOP | 12.47 | +| HCW | (C1) | ESC 03/08 | HARD COPY WAIT | 12.48 | +| RDS | (C1) | ESC 03/06 | RECORDING DEVICE START | 12.74 | +| RDT | (C1) | ESC 03/07 | RECORDING DEVICE STOP | 12.75 | +| RDW | (C1) | ESC 03/05 | RECORDING DEVICE WAIT | 12.76 | + +## 11.3 Display control functions + +| Acronym | Notation | Coded representation | Name | Defined in | +|-------------------------|----------|------------------------------------|-------------------------------|------------| +| <b>Videotex (T.101)</b> | | | | | +| AIS | (Pn) | CSI 03/02 06/00 | ACTIVATE IMPLICIT SCROLLING | 12.4 | +| DIS | (Pn) | CSI 03/03 06/00 | DEACTIVATE IMPLICIT SCROLLING | 12.29 | +| SCD | (Pn) | CSI 03/01 06/00 | SCROLL DOWN | 12.84 | +| SCF | (C1) | ESC 05/08 (7-bit)<br>09/08 (8-bit) | SCROLL OFF | 12.85 | +| SCN | (C1) | ESC 05/07 (7-bit)<br>09/07 (8-bit) | SCROLL ON | 12.86 | +| SCU | (Pn) | CSI 03/00 06/00 | SCROLL UP | 12.89 | +| WWF | (C1) | ESC 05/06 (7-bit)<br>09/06 (8-bit) | WORD WRAP OFF | 12.117 | +| WWN | (C1) | ESC 05/05 (7-bit)<br>09/05 (8-bit) | WORD WRAP ON | 12.118 | + +## 11.4 Format effectors + +| Acronym | Notation | Coded representation | Name | Defined in | +|-------------------------|----------|------------------------------------|----------------------------|------------| +| <b>Videotex (T.101)</b> | | | | | +| APA | (C0) | 01/15 | ACTIVE POSITION ADDRESSING | 12.5 | +| APB | (C0) | 00/08 | ACTIVE POSITION BACKWARD | 12.6 | +| APD | (C0) | 00/10 | ACTIVE POSITION DOWN | 12.7 | +| APF | (C0) | 00/09 | ACTIVE POSITION FORWARD | 12.8 | +| APH | (C0) | 01/14 | ACTIVE POSITION HOME | 12.9 | +| APR | (C0) | 00/13 | ACTIVE POSITION RETURN | 12.10 | +| APS | (C0) | 01/12 | ACTIVE POSITION SET | 12.11 | +| APU | (C0) | 00/11 | ACTIVE POSITION UP | 12.12 | +| CS | (C0) | 00/12 | CLEAR SCREEN | 12.20 | +| NSR | (C0) | 01/15 | NON-SELECTIVE RESET | 12.68 | +| ROL | (C1) | ESC 04/07 (7-bit)<br>08/07 (8-bit) | REPEAT TO END OF LINE | 12.79 | +| RPC | (C1) | ESC 05/08 (7-bit)<br>09/08 (8-bit) | REPEAT CONTROLS | 12.80 | +| RPT | (C0) | 01/02 | REPEAT | 12.81 | + +| Acronym | Notation | Coded representation | Name | Defined in | +|------------------------|----------|------------------------------------|-----------------------------|------------| +| <b>Teletex (T.61)</b> | | | | | +| BS | (C0) | 00/08 | BACKSPACE | 12.15 | +| CR | (C0) | 00/13 | CARRIAGE RETURN | 12.19 | +| FF | (C0) | 00/12 | FORM FEED | 12.41 | +| LF | (C0) | 00/10 | LINE FEED | 12.58 | +| PLD | (C1) | ESC 04/11 (7-bit)<br>08/11 (8-bit) | PARTIAL LINE FORWARD | 12.71 | +| PLU | (C1) | ESC 04/12 (7-bit)<br>08/12 (8-bit) | PARTIAL LINE BACKWARD | 12.72 | +| RI | (C1) | ESC 04/13 (7-bit)<br>08/13 (8-bit) | REVERSE LINE FEED | 12.78 | +| SP | (Cx) | 02/00 | SPACE (see 8.6) | 12.101 | +| <b>Facsimile (T.4)</b> | | | | | +| CR | (C0) | 00/13 | CARRIAGE RETURN | 12.19 | +| FF | (C0) | 00/12 | FORM FEED | 12.41 | +| HT | (C0) | 00/09 | CHARACTER TABULATION | 12.51 | +| LF | (C0) | 00/10 | LINE FEED | 12.58 | +| <b>ODA (T.416)</b> | | | | | +| CR | (C0) | 00/13 | CARRIAGE RETURN | 12.19 | +| HPB | (Pn) | CSI Pn 06/01 | CHARACTER POSITION BACKWARD | 12.49 | +| HPR | (Pn) | CSI Pn 06/01 | CHARACTER POSITION FORWARD | 12.50 | +| LF | (C0) | 00/10 | LINE FEED | 12.58 | +| PLD | (C1) | ESC 04/11 (7-bit)<br>08/11 (8-bit) | PARTIAL LINE FORWARD | 12.71 | +| PLU | (C1) | ESC 04/12 (7-bit)<br>08/12 (8-bit) | PARTIAL LINE BACKWARD | 12.72 | +| SP | (Cx) | 02/00 | SPACE (see 8.6) | 12.101 | +| VPB | (Pn) | CSI Pn 06/11 | LINE POSITION BACKWARD | 12.115 | +| VPR | (Pn) | CSI Pn 06/05 | LINE POSITION FORWARD | 12.116 | +| <b>(T.53)</b> | | | | | +| REP | (Pn) | CSI Pn 06/02 | REPEAT | 12.77 | + +## 11.5 Information separators + +| Acronym | Notation | Coded representation | Name | Defined in | +|-------------------------|----------|----------------------|-------------------------------------------------------------------------|------------| +| <b>(T.53)</b> | | | | | +| IS1<br>(US) | (C0) | 01/15 | INFORMATION SEPARATOR ONE<br>(UNIT SEPARATOR) | 12.53 | +| IS2<br>(RS) | (C0) | 01/14 | INFORMATION SEPARATOR TWO<br>(RECORD SEPARATOR) | 12.54 | +| IS3<br>(GS)<br>(PT) | (C0) | 01/13 | INFORMATION SEPARATOR THREE<br>(GROUP SEPARATOR)<br>(PAGE TERMINATOR) | 12.55 | +| IS4<br>(FS)<br>(DT) | (C0) | 01/12 | INFORMATION SEPARATOR FOUR<br>(FILE SEPARATOR)<br>(DOCUMENT TERMINATOR) | 12.56 | +| <b>Videotex (T.101)</b> | | | | | +| US | (C0) | 00/07 | UNIT SEPARATOR | 12.53 | + +## 11.6 Introducers + +| Acronym | Notation | Coded representation | Name | Defined in | +|------------------------|----------|------------------------------------|-----------------------------|------------| +| <b>“Common” (T.53)</b> | | | | | +| CSI | (C1) | ESC 05/11 (7-bit)<br>09/11 (8-bit) | CONTROL SEQUENCE INTRODUCER | 12.21 | +| ESC | (C0) | 01/11 | ESCAPE | 12.38 | + +## 11.7 Miscellaneous control functions + +| Acronym | Notation | Coded representation | Name | Defined in | +|-------------------------|----------|----------------------|--------------------------------|------------| +| <b>Videotex (T.101)</b> | | | | | +| BEL | (C0) | 00/07 | BELL | 12.13 | +| CAN | (C0) | 01/08 | CANCEL | 12.16 | +| DEL | (Cx) | 07/15 | DELETE (see 8.6) | 12.28 | +| NUL | (C0) | 00/00 | NULL | 12.69 | +| <b>Teletex (T.61)</b> | | | | | +| IGS | (Ps) | CSI Ps 02/00 04/13 | IDENTIFY GRAPHIC SUBREPERTOIRE | 12.52 | +| SUB | (C0) | 01/10 | SUBSTITUTE | 12.112 | +| <b>ODA (T.416)</b> | | | | | +| IGS | (Ps) | CSI Ps 02/00 04/13 | IDENTIFY GRAPHIC SUBREPERTOIRE | 12.52 | +| SUB | (C0) | 01/10 | SUBSTITUTE | 12.112 | + +## 11.8 Presentation control functions + +| Acronym | Notation | Coded representation | Name | Defined in | +|-------------------------|------------|-------------------------|------------------------------------------|------------| +| <b>“Common” (T.53)</b> | | | | | +| SGR | (Ps...) | CSI Ps...06/13 | SELECT GRAPHIC RENDITION | 12.91 | +| <b>Videotex (T.101)</b> | | | | | +| FNT | (Ps1; Ps2) | CSI Ps1 Ps2 02/00 04/04 | FONT SELECTION | 12.42 | +| SAPV | (Ps...) | CSI Ps... 02/00 05/13 | SELECT ALTERNATIVE PRESENTATION VARIANTS | 12.83 | +| SDS | (Ps) | CSI Ps 05/13 | START DIRECTED STRING | 12.90 | +| SHS | (Ps) | CSI Ps 02/00 04/11 | SELECT CHARACTER SPACING | 12.92 | +| SPD | (PS1; Ps2) | CSI Ps1 Ps2 02/00 05/03 | SLECT PRESENTATION DIRECTIONS | 12.102 | +| SRS | (Ps) | CSI Ps 05/11 | START REVERSED STRING | 12.104 | + +| Acronym | Notation | Coded representation | Name | Defined in | +|-----------------------|------------|------------------------------------|-------------------------------------|------------| +| <b>Teletex (T.61)</b> | | | | | +| GSM | (Pn1; Pn2) | CSI Pn1 Pn2 02/00 04/02 | GRAPHIC SIZE MODIFICATION | 12.44 | +| PFS | (Ps) | CSI Ps 02/00 04/10 | PAGE FORMAT SELECTION | 12.70 | +| SCO | (Ps) | CSI Ps 02/00 06/05 | SELECT CHARACTER ORIENTATION | 12.87 | +| SDS | (Ps) | CSI Ps 05/13 | START DIRECTED STRING | 12.90 | +| SHS | (Ps) | CSI Ps 02/00 04/11 | SELECT CHARACTER SPACING | 12.92 | +| SPD | (Ps1; Ps2) | CSI Ps1 Ps2 02/00 05/03 | SELECT PRESENTATION DIRECTIONS | 12.102 | +| SVS | (Ps) | CSI Ps 02/00 04/12 | SELECT LINE SPACING | 12.113 | +| <b>ODA (T.416)</b> | | | | | +| BPH | (C1) | ESC 04/02 (7-bit)<br>08/02 (8-bit) | BREAK PERMITTED HERE | 12.14 | +| GCC | (Ps) | CSI Ps 02/00 05/15 | GRAPHIC CHARACTER COMPOSITION | 12.43 | +| JFY | (Ps...) | CSI Ps... 02/00 04/06 | JUSTIFY | 12.57 | +| NBH | (C1) | ESC 04/03 (7-bit)<br>08/03 (8-bit) | NO BREAK HERE | 12.67 | +| PTX | (Ps) | CSI Ps 05/12 | PARALLEL TEXTS | 12.73 | +| SACS | (Pn) | CSI Pn 02/00 05/12 | SET ADDITIONAL CHARACTER SEPARATION | 12.82 | +| SCS | (Pn) | CSI Pn 02/00 06/07 | SET CHARACTER SPACING | 12.88 | +| SHS | (Ps) | CSI Ps 02/00 04/11 | SELECT CHARACTER SPACING | 12.92 | +| SLS | (Pn) | CSI Pn 02/00 06/08 | SET LINE SPACING | 12.97 | +| SRCS | (Pn) | CSI Pn 02/00 06/06 | SET REDUCED CHARACTER SEPARATION | 12.103 | +| SRS | (Ps) | CSI Ps 05/11 | START REVERSED STRING | 12.104 | +| SSW | (Pn) | CSI Pn 02/00 05/11 | SET SPACE WIDTH | 12.106 | +| STAB | (Ps) | CSI Ps 02/00 05/14 | SELECTIVE TABULATION | 12.110 | +| SVS | (Ps) | CSI Ps 02/00 04/12 | SELECT LINE SPACING | 12.113 | +| <b>(T.53)</b> | | | | | +| GSS | (Pn) | CSI Pn 02/00 04/03 | GRAPHIC SIZE SELECTION | 12.45 | +| SIMD | (Ps) | CSI Ps 05/14 | SELECT IMPLICIT MOVEMENT DIRECTION | 12.94 | +| SLH | (Pn) | CSI Pn 02/00 05/05 | SET LINE HOME | 12.95 | +| SLL | (Pn) | CSI Pn 02/00 05/06 | SET LINE LIMIT | 12.96 | +| SSU | (Ps) | CSI Ps 02/00 04/09 | SELECT SIZE UNIT | 12.105 | + +## 11.9 Shift functions + +| Acronym | Notation | Coded representation | Name | Defined in | +|-------------------------|----------|-----------------------------------------------------------|---------------------------|------------| +| <b>“Common” (T.53)</b> | | | | | +| LSO | (C0) | 00/15 | LOCKING-SHIFT ZERO | 12.59 | +| LS1 | (C0) | 00/14 | LOCKING-SHIFT ONE | 12.60 | +| LS1R | (Fs) | ESC 07/14 | LOCKING-SHIFT ONE RIGHT | 12.61 | +| LS2 | (Fs) | ESC 06/14 | LOCKING-SHIFT TWO | 12.62 | +| LS2R | (Fs) | ESC 07/13 | LOCKING-SHIFT TWO RIGHT | 12.63 | +| LS3 | (Fs) | ESC 06/15 | LOCKING-SHIFT THREE | 12.64 | +| LS3R | (Fs) | ESC 07/12 | LOCKING-SHIFT THREE RIGHT | 12.65 | +| SS2 | (C1) | ESC 04/14 (7-bit)<br>08/14 (8-bit)<br>01/09 (T.61, T.101) | SINGLE-SHIFT TWO | 12.107 | +| SS3 | (C1) | ESC 04/15 (7-bit)<br>08/15 (8-bit)<br>01/13 (T.61, T.101) | SINGLE-SHIFT THREE | 12.108 | +| <b>Videotex (T.101)</b> | | | | | +| SI | (C0) | 00/15 | SHIFT-IN | 12.93 | +| SO | (C0) | 00/14 | SHIFT-OUT | 12.98 | +| SS2 | (C1) | 01/09 | SINGLE-SHIFT TWO | 12.107 | +| SS3 | (C1) | 01/13 | SINGLE-SHIFT THREE | 12.108 | +| <b>Teletex (T.61)</b> | | | | | +| SS2 | (C1) | 01/09 | SINGLE-SHIFT TWO | 12.107 | +| SS3 | (C1) | 01/13 | SINGLE-SHIFT THREE | 12.108 | +| <b>ODA (T.416)</b> | | | | | +| SI | (C0) | 00/15 | SHIFT-IN | 12.93 | +| SO | (C0) | 00/14 | SHIFT-OUT | 12.98 | + +## 11.10 Transmission control functions + +| Acronym | Notation | Coded representation | Name | Defined in | +|-------------------------------------------------------------------------------|----------|----------------------|---------------------------|------------| +| <b>Videotex (T.101)</b> | | | | | +| ACK | (C0) | 00/06 | ACKNOWLEDGE | 12.1 | +| DLE | (C0) | 01/00 | DATA LINK ESCAPE | 12.30 | +| ENQ | (C0) | 00/05 | ENQUIRY | 12.36 | +| EOT | (C0) | 00/04 | END OF TRANSMISSION | 12.37 | +| ETB | (C0) | 01/07 | END OF TRANSMISSION BLOCK | 12.39 | +| ETX | (C0) | 00/03 | END OF TEXT | 12.40 | +| NAK | (C0) | 01/05 | NEGATIVE ACKNOWLEDGE | 12.66 | +| SOH | (C0) | 00/01 | START OF HEADING | 12.99 | +| STX | (C0) | 00/02 | START OF TEXT | 12.111 | +| SYN | (C0) | 01/06 | SYNCHRONOUS IDLE | 12.114 | +| NOTE – Some Telematic services do not use control functions for transmission. | | | | | + +# 12 Definition of control functions + +The control functions are listed in the alphabetical order of their acronyms. The acronyms shall be retained in all translations of the text. + +The definitions of the control functions cover bi-directional devices which have both a presentation component and a data component. + +In the case of a uni-directional device or a bi-directional device without a data component, all references to active data position, data component, character progression, etc., are to be read as referring to active presentation position, presentation component, character path, etc., respectively (see Note). This also means that the use of the control functions in implementations already existing, is not affected by the inclusion of bi-directional capabilities in this Recommendation. + +NOTE – This Recommendation specifies a basic device profile for Telematic services based on a bi-directional device with presentation component only. + +## 12.1 ACKNOWLEDGE (ACK) + +Notation: (C0) + +Representation: 00/06 + +ACK is transmitted by a receiver as an affirmative response to the sender. + +The use of ACK is defined in ISO 1745. + +## 12.2 AUXILIARY DEVICE OFF (ADF) (used only in Recommendation T.101) + +Notation: (C0) + +Representation: ESC 03/15 + +Data subsequently received by the terminal is not passed to the auxiliary device. + +## **12.3      AUXILIARY DEVICE ON (ADO)** (used only in Recommendation T.101) + +Notation: (C0) + +Representation: ESC 03/14 + +Data subsequently received by the terminal is passed to the auxiliary device. + +## **12.4      ACTIVATE IMPLICIT SCROLLING (AIS)** (used only in Recommendation T.101) + +Notation: (Pn) + +Representation: CSI 03/02 06/00 + +A device control function which restores the implicit scrolling effect of format effectors. + +## **12.5      ACTIVE POSITION ADDRESSING (APA)** (used only in Recommendation T.101) + +Notation: (C0) + +Representation: 01/15 + +A format effector which causes the active position to move to a defined position on the screen in accordance with parameters following. + +## **12.6      ACTIVE POSITION BACKWARD (APB)** (used only in Recommendation T.101) + +Notation: (C0) + +Representation: 00/08 + +APB causes the active position to move backwards one character position on the same row. At the first character position on the row it moves the active position to the last character position of the preceding row. On the first character position of the first row it moves the active position to the last character position of the last row in the defined display area. + +## **12.7      ACTIVE POSITION DOWN (APD)** (used only in Recommendation T.101) + +Notation: (C0) + +Representation: 00/10 + +APD causes the active position to the equivalent character position on the following row. On the last row it moves the active position to the equivalent character position on the first row in the defined display area. + +## **12.8      ACTIVE POSITION FORWARD (APF)** (used only in Recommendation T.101) + +Notation: (C0) + +Representation: 00/09 + +APF causes the active position to move forward to the next character position on the same row. At the last position on the row, it moves the active position to the first character position on the following row. On the last character of the last row it moves the active position to the first character position on the first row in the defined display area. + +See also CHARACTER POSITION FORWARD (HPR). + +## **12.9 ACTIVE POSITION HOME (APH) (used only in Recommendation T.101)** + +Notation: (C0) + +Representation: 01/14 + +APH is used to position the cursor to the upper left character position in the defined display area. + +## **12.10 ACTIVE POSITION RETURN (APR) (used only in Recommendation T.101)** + +Notation: (C0) + +Representation: 00/13 + +APR causes the active position to move to the first character position of the same row. + +## **12.11 ACTIVE POSITION SET (APS) (used only in Recommendation T.101)** + +Notation: (C0) + +Representation: 01/12 + +This character is used to set the cursor position without resetting any parameters or attributes. APS is used to set the cursor position which is specified by two-bytes parameter immediately following an APS. The two bytes shall come from columns 02 through 07 or 10 through 15. The first byte represents the row address and the second byte does the column address. The address is obtained by taking the binary values comprising bits b7 through b1 with b7 being the MSB, masking out b8 and subtracting 32. This gives an address range from 0 through 95 inclusive for the row and column addresses. For example, the bit combination 03/06 yields the binary integer 54, which after subtracting 32, gives the address 22. If either of the characters following the APS character is a C0 or C1 control, the APS is ignored and the C0 or C1 control is executed. + +Rows and columns are numbered starting with row 0, column 0, in the lower leftmost character position of the display area, and refer to the nominal screen format established by the current character field size (with the default intercharacter and interrow spacing). The cursor is positioned assuming zero character rotation to establish the character field origin. Once the character field origin is established, the character field and cursor are rotated, if necessary. + +## **12.12 ACTIVE POSITION UP (APU) (used only in Recommendation T.101)** + +Notation: (C0) + +Representation: 00/11 + +APU causes the active position to move to the equivalent character position on the preceding row. On the first row it moves the active position to the equivalent character position on the last row in the defined display area. + +## **12.13 BELL (BEL)** + +Notation: (C0) + +Representation: 00/07 + +BEL is used when there is a need to call for attention; it may control alarm or attention devices. + +## **12.14 BREAK PERMITTED HERE (BPH)** + +Notation: (C1) + +Representation: ESC 04/02 (in 7-bit code) or 08/02 (in 8-bit code) + +BPH is used to indicate a point where a line break may occur when text is formatted. BPH may occur between two graphic characters, either or both of which may be SPACE. + +## 12.15 BACKSPACE (BS) + +Notation: (C0) + +Representation: 00/08 + +BS causes the active data position to be moved one character position in the direction opposite to that of the implicit movement. + +The direction of the implicit movement depends on the parameter value of SELECT IMPLICIT MOVEMENT DIRECTION (SIMD). + +The amount of movement depends on the character spacing established by the most recent occurrence of SELECT CHARACTER SPACING (SHS), if any, or otherwise is the default character spacing. + +BS shall not be used for combining the images of two or more graphic symbols in a single character position. + +### NOTES + +1 The control function SET SPACE WIDTH (SSW) has no effect on BS. + +2 The use of BS in document application profiles based on Recommendation T.416 | ISO 8613-6 is deprecated; it is included only for compatibility with Recommendation T.61. Instead, the control function CHARACTER POSITION BACKWARD (HPB) with parameter value Pn = 1 shall be implemented. + +## 12.16 CANCEL (CAN) + +Notation: (C0) + +Representation: 01/08 + +CAN is used to indicate that the data preceding it in the data stream is in error. As a result, this data shall be ignored. The specific meaning of this character shall be defined for each application and/or between sender and recipient. + +## 12.17 CURSOR OFF (COF) (used only in Recommendation T.101) + +Notation: (C0) + +Representation: 01/04 + +COF terminates the action of CURSOR ON (CON). + +NOTE – Recommendation T.101 – DS II defines CURSOR OFF (COF) as an implementation-dependent case of DEVICE CONTROL FOUR (DC4). + +## 12.18 CURSOR ON (CON) (used only in Recommendation T.101) + +Notation: (C0) + +Representation: 01/01 + +CON causes the active position to be indicated. + +NOTE – Recommendation T.101 – DS II defines CURSOR ON (CON) as an implementation-dependent case of DEVICE CONTROL ONE (DC1). + +## 12.19 CARRIAGE RETURN (CR) + +Notation: (C0) + +Representation: 00/13 + +The effect of CR depends on the parameter value of SELECT IMPLICIT MOVEMENT DIRECTION (SIMD). + +For devices with presentation component and with the parameter value of SIMD equal to 0, CR causes the active presentation position to be moved to the line home position of the same line in the presentation component. + +For devices with presentation component and with the parameter value of SIMD equal to 1, CR causes the active presentation position to be moved to the line limit position of the same line in the presentation component. + +For devices with data component and with the parameter value of SIMD equal to 0, CR causes the active data position to be moved to the line home position of the same line in the data component. + +For devices with data component and with the parameter value of SIMD equal to 1, CR causes the active data position to be moved to the line limit position of the same line in the data component. + +The line home position is established by the parameter value of SET LINE HOME (SLH). + +The line limit position is established by the parameter value of SET LINE LIMIT (SLL). + +CR shall not be used for combining the images of two or more graphic symbols in a single character position. + +### NOTES + +1 The Telematic services do not define the line home position and line limit position, by the SLH, respectively SLL control functions. + +2 The line home position for various page formats used in the Teletex service (also in ISO/IEC 10538), is specified in C.2. + +## 12.20 CLEAR SCREEN (CS) + +Notation: (C0) + +Representation: 00/12 + +CS causes the active position to be moved to the first character position of the first row in the defined display area and causes all character positions to be filled with SPACES with all attributes set to the default conditions. + +## 12.21 CONTROL SEQUENCE INTRODUCER (CSI) + +Notation: (C1) + +Representation: ESC 05/11 (in 7-bit code) or 09/11 (in 8-bit code) + +CSI is used as the first character of a control sequence, to provide representations for additional control functions, in particular for control functions with parameters, such as presentation control functions. + +## 12.22 DEVICE CONTROL ONE (DC1) + +Notation: (C0) + +Representation: 01/01 + +DC1 is primarily intended for turning on or starting an ancillary device. If it is not required for this purpose, it may be used to restore a device to the basic mode of operation ( see also DC2 and DC3), or for any other device control function not provided by other DC's. + +### NOTES + +1 When used for data flow control, DC1 is sometimes called "X-ON". + +2 Recommendation T.101 – DS II defines the implementation-dependent specific case of DC1: CURSOR ON (CON). + +## 12.23 DEVICE CONTROL TWO (DC2) + +Notation: (C0) + +Representation: 01/02 + +DC2 is primarily intended for turning on or starting an ancillary device. If it is not required for this purpose, it may be used to set a device to a special mode of operation (in which case DC1 is used to restore the device to the basic mode), or for any other device control function not provided by other DC's. + +## 12.24 DEVICE CONTROL THREE (DC3) + +Notation: (C0) + +Representation: 01/03 + +DC3 is primarily intended for turning off or stopping an ancillary device. This function may be a secondary level stop, for example wait, pause, stand-by or halt (in which case DC1 is used to restore normal operation). If it is not required for this purpose, it may be used for any other ancillary device control function not provided by other DC's. + +NOTE – When used for data flow control, DC3 is sometimes called “X-OFF”. + +## 12.25 DEVICE CONTROL FOUR (DC4) + +Notation: (C0) + +Representation: 01/04 + +DC4 is primarily intended for turning off, stopping or interrupting an ancillary device. It is not required for this purpose, it may be used for any other device control function not provided by other DC's. + +NOTE – Recommendation T.101 - DS II defines the implementation-dependent specific case of DC4: CURSOR OFF (COF). + +## 12.26 DISPLAY DEVICE OFF (DDF) (used only in Recommendation T.101) + +Notation: (C1) + +Representation: ESC 03/13 + +DDF causes the subsequently received data by the terminal not to be displayed. + +## 12.27 DISPLAY DEVICE ON (DDO) (used only in Recommendation T.101) + +Notation: (C1) + +Representation: ESC 03/12 + +DDO causes the subsequently received data by the terminal to be displayed. + +## 12.28 DELETE (DEL) (used only in Recommendation T.101) + +Notation: (Cx) + +Representation: 07/15 + +A character used primarily to erase or obliterate an erroneous or unwanted character in punched tape. DEL characters may also serve to accomplish media-fill or time-fill. They may be inserted into, or removed from, a stream of data without affecting the information content of the stream, but such action may affect the information layout and/or the control equipment. + +### NOTES + +1 When a set of 96 graphic characters is invoked into columns 02 to 07, or when the last character of such a set is invoked by a single-shift function, bit combination 07/15 will not have the meaning of DEL. + +2 DEL is not a control function in the strict sense. Its control functionality can be achieved by other control functions. The reason of maintaining it in this Recommendation is only for backward compatibility. The use of DEL is deprecated. It is foreseen to remove DEL from the next edition of this Recommendation. + +## **12.29 DEACTIVATE IMPLICIT SCROLLING (DIS)** (used only in Recommendation T.101) + +Notation: (Pn) + +Representation: CSI 03/00 06/00 + +DIS deactivates the implicit scrolling, allowing the active presentation position in to move across the border of a scrolling area. + +## **12.30 DATA LINK ESCAPE (DLE)** + +Notation: (C0) + +Representation: 01/00 + +DLE is used exclusively to provide supplementary transmission control functions. + +DLE will change the meaning of a limited number of contiguously following bit combinations. Only graphic characters and transmission control characters may be used in DLE sequences. + +The use of DLE is defined in ISO 1745. + +## **12.31 EMPTY BUFFER (EBU)** (used only in Recommendation T.101) + +Notation: (C1) + +Representation: ESC 03/11 + +EBU causes the contents of the terminal buffer to be transmitted to the line. + +## **12.32 EXTENDED DEVICE CONTROL ONE (EDC1)** (used only in Recommendation T.101) + +Notation: (C1) + +Representation: ESC 05/01 (in 7-bit code) or 09/01 (in 8-bit code) + +The precise meaning of EDC1, is reserved for future standardization, and is executed as NULL. + +## **12.33 EXTENDED DEVICE CONTROL TWO (EDC2)** (used only in Recommendation T.101) + +Notation: (C1) + +Representation: ESC 05/02 (in 7-bit code) or 09/02 (in 8-bit code) + +The precise meaning of EDC2, is reserved for future standardization, and is executed as NULL. + +## **12.34 EXTENDED DEVICE CONTROL THREE (EDC3)** (used only in Recommendation T.101) + +Notation: (C1) + +Representation: ESC 05/03 (in 7-bit code) or 09/03 (in 8-bit code) + +The precise meaning of EDC3, is reserved for future standardization, and is executed as NULL. + +## **12.35 EXTENDED DEVICE CONTROL FOUR (EDC4)** (used only in Recommendation T.101) + +Notation: (C1) + +Representation: ESC 05/04 (in 7-bit code) or 09/04 (in 8-bit code) + +The precise meaning of EDC4, is reserved for future standardization, and is executed as NULL. + +## **12.36 ENQUIRY (ENQ)** + +Notation: (C0) + +Representation: 00/05 + +ENQ is transmitted by a sender as a request for a response from a receiver. + +The response may include station identification and/or station status. When a “Who are you” function is required on the general switched transmission network, the first use of ENQ after the connection is established shall have the meaning “Who are you” (station identification). Subsequent use of ENQ may, or may not, include the function “Who are you”, as determined by agreement. + +The use of ENQ is defined in ISO 1745. + +## **12.37 END OF TRANSMISSION (EOT)** + +Notation: (C0) + +Representation: 00/04 + +EOT is used to indicate the conclusion of the transmission of one or more texts. + +The use of EOT is defined in ISO 1745. + +## **12.38 ESCAPE (ESC)** + +Notation: (C0) + +Representation: 01/11 + +ESC is used for code extension purposes. It causes the meanings of a limited number of bit combinations following it in the data stream to be changed. + +The use of ESC is defined in ISO 2022. + +NOTE – In applications based on Recommendation T.50, it is a transmission control character preceding a text and it is used to terminate a heading. + +## **12.39 END OF TRANSMISSION BLOCK (ETB)** + +Notation: (C0) + +Representation: 01/07 + +ETB is used to indicate the end of a block of data where the data are divided into such blocks for transmission purposes. + +The use of ETB is defined in ISO 1745. + +## **12.40 END OF TEXT (ETX)** + +Notation: (C0) + +Representation: 00/03 + +ETX is used to indicate the end of a text. + +It is defined in ISO 1745 and Recommendation T.50. + +## **12.41 FORM FEED (FF)** + +Notation: (C0) + +Representation: 00/12 + +FF causes the active presentation position to be moved to the corresponding character position of the line at the page home position of the next form or page in the presentation component. + +The text area format is that specified by the most recent occurrence of PAGE FORMAT SELECTION (PFS), if any, or otherwise is the default text area format. + +Following an occurrence of SELECT PRESENTATION DIRECTIONS (SPD) with another than the default parameter or an occurrence of PFS with a parameter value other than 0 to 9, FF shall be followed by CR in order to move the active presentation position to the line home position of the first line of the new page. + +NOTE – Different Recommendations make use of control functions with similar functionality as FF, identical coding but with a different name and acronym, e.g. Recommendation T.101 defines the control function: CLEAR SCREEN (CS). + +## **12.42 FONT SELECTION (FNT)** + +Notation: (Ps1;Ps2) + +Representation: CSI Ps1 Ps2 02/00 04/04 + +Parameter default values: Ps1 = 0; Ps2 = 0 + +FNT is used to identify the character font to be selected as primary or alternative font by subsequent occurrences of SELECT GRAPHIC RENDITION (SGR) in the data stream. + +Ps1 specifies the primary or alternative font concerned: + +- 0 Primary font +- 1 First alternative font +- 2 Second alternative font +- 3 Third alternative font +- 4 Fourth alternative font +- 5 Fifth alternative font +- 6 Sixth alternative font +- 7 Seventh alternative font +- 8 Eighth alternative font +- 9 Ninth alternative font + +Ps2 identifies the character font according to a register which is to be established. + +## **12.43 GRAPHIC CHARACTER COMBINATION (GCC)** + +Notation: (Ps) + +Representation: CSI Ps 02/00 05/15 + +Parameter default value: Ps = 0 + +GCC is used to indicate that two or more graphic characters are to be imaged as one single graphic symbol. GCC with a parameter value of 0 indicates that the following two graphic characters are to be imaged as one single graphic symbol; GCC with a parameter value of 1 and GCC with a parameter value of 2 indicate respectively the beginning and the end of a string of graphic characters which are to be imaged as one single graphic symbol. + +NOTE – GCC does not explicitly specify the relative sizes or placements of the component parts of a composite graphic symbol. In the simplest case, two components may be “half-width” and side-by-side. For example, in Japanese text a pair of characters may be presented side-by-side, and occupy the space of a normal-size Kanji character. + +## **12.44 GRAPHIC SIZE MODIFICATION (GSM)** + +Notation: (Pn1,Pn2) + +Representation: CSI Pn1 Pn2 02/00 04/02 + +Parameter default values: Pn1 = 100; Pn2 = 100 + +GSM is used to modify for subsequent text the height and/or the width of all primary and alternative fonts identified by FONT SELECTION (FNT) and established by GRAPHIC SIZE SELECTION (GSS). The established values remain in effect until the next occurrence of GSM or GSS in the data stream. + +Pn1 specifies the height as a percentage of the height established by GSS. + +Pn2 specifies the width as a percentage of the width established by GSS. + +NOTE – Recommendation T.61 specifies the following parameter values with effect on the character spacing (as specified by SHS or SCS) and size, as follows: + +- a) *For horizontal line orientation* (SPD parameter Ps1 = 0, 3, 5 or 6) + +GSM 100, 50 causes character spacing and width to be halved + +GSM 100, 100 has no effect + +GSM 100, 200 causes character spacing and width to be doubled. + +- b) *For vertical line orientation* (SPD parameter Ps1 = 1, 2, 4 or 7) + +GSM 100, 100 has no effect + +GSM 100, 200 causes character spacing and height to be doubled. + +## **12.45 GRAPHIC SIZE SELECTION (GSS)** + +Notation: (Pn) + +Representation: CSI Pn 02/00 04/03 + +Parameter default value: None + +GSS is used to establish for subsequent text the height and the width of all primary and alternative fonts identified by FONT SELECTION (FNT). The established values remain in effect until the next occurrence of GSS in the data stream. + +Pn specifies the height, the width is implicitly defined by the height. + +The unit in which the parameter value is expressed is that established by the parameter value of SELECT SIZE UNIT (SSU). + +## **12.46 HARD COPY START (HCS) (used only in Recommendation T.101)** + +Notation: (C1) + +Representation: ESC 03/09 + +HCS causes the associated hard copy device to start copying data subsequently received by the terminal. + +## **12.47 HARD COPY STOP (HCT) (used only in Recommendation T.101)** + +Notation: (C1) + +Representation: ESC 03/10 + +HCT causes the associated hard copy device to stop. + +## **12.48 HARD COPY WAIT (HCW) (used only in Recommendation T.101)** + +Notation: (C1) + +Representation: ESC 03/08 + +HCW causes the associated hard copy device to wait. + +## 12.49 CHARACTER POSITION BACKWARD (HPB) + +Notation: (Pn) + +Representation: CSI Pn 06/10 + +Parameter default value: Pn = 1 (See Note) + +HPB causes the active data position to be moved by n character positions in the data component in the direction opposite to that of the character progression, where n equals the value of Pn. + +NOTE – CCITT Rec. T.416 | ISO 8613-6 defines the parameter default value of HPB as the equivalent of 120 BMUs, where BMU (BASIC MEASUREMENT UNIT) has the value of 1/1200 of 25,4 mm (0,02117 mm). + +Also it mentions that the main purposes of HPB are to move the active data position backwards from the line home position and to provide for the positioning of parallel annotation. + +## 12.50 CHARACTER POSITION FORWARD (HPR) + +Notation: (Pn) + +Representation: CSI Pn 06/01 + +Parameter default value: Pn = 1 (See Note 1) + +HPR causes the active data position to be moved by n character positions in the data component in the direction of the character progression, where n equals the value of Pn. + +### NOTES + +1 CCITT Recommendation T.416 | ISO 8613-6 defines the parameter default value of HPR as the equivalent of 120 BMUs, where BMU (BASIC MEASUREMENT UNIT) has the value of 1/1200 of 25,4 mm (0,02117 mm). + +Also it mentions that one of the main purposes of HPR is to provide for the positioning of parallel annotation. + +2 Although HPR has a control effect similar to that of one or more SPACE characters, it does not have the graphic equivalence of SPACE characters. Therefore, HPR does not cause spaces to be imaged in accordance with the current graphic rendition, such as underlined, possibly specified by a preceding occurrence of the control function SELECT GRAPHIC RENDITION (SGR). + +## 12.51 CHARACTER TABULATION (HT) + +Notation: (C0) + +Representation: 00/09 + +HT causes the active presentation position to be moved to the following character tabulation stop in the presentation component. + +## 12.52 IDENTIFY GRAPHIC SUBREPERTOIRE (IGS) + +Notation: (Ps) + +Representation: CSI Ps 02/00 04/13 + +Parameter default value: None + +IGS is used to indicate that a subrepertoire of the graphic character repertoire of ISO/IEC 10367 is used in the subsequent text. All graphic characters needed to represent the indicated subrepertoire shall be explicitly or implicitly designated, but need not be invoked, prior to the occurrence of IGS. The identification of the graphic character subrepertoire may be changed at any point within the document and takes effect immediately. + +The effect of IGS ceases upon the next occurrence of: + +- a) another IGS; +- b) the control function PAGE TERMINATOR (PT); +- c) the control function DOCUMENT TERMINATOR (DT); +- d) the designation of any graphic character set. + +The parameter value is the identifier assigned to a subrepertoire of the repertoire of ISO/IEC 10367 in accordance with the registration procedure specified in ISO/IEC 7350. In the absence of IGS, the entire repertoire of the currently designated graphic character set applies. An occurrence of IGS without a parameter value cancels any subrepertoire identification by a preceding IGS. + +## **12.53 INFORMATION SEPARATOR ONE (US – UNIT SEPARATOR) (IS1)** + +Notation: (C0) + +Representation: 01/15 + +IS1 is used to separate and qualify data logically; its specific meaning has to be defined for each application. If this control function is used in hierarchical order, it may delimit a data item called a unit. In this case the control function is named UNIT SEPARATOR (US). + +## **12.54 INFORMATION SEPARATOR TWO (IS2) – RECORD SEPARATOR (RS)** + +Notation: (C0) + +Representation: 01/14 + +IS2 is used to separate and qualify data logically; its specific meaning has to be defined for each application. If this control function is used in hierarchical order, it may delimit a data item called a record. In this case the control function is named RECORD SEPARATOR (RS). + +## **12.55 INFORMATION SEPARATOR THREE (IS3) [GROUP SEPARATOR (GS)]** + +Notation: (C0) + +Representation: 01/13 + +IS3 is used to separate and qualify data logically; its specific meaning has to be defined for each application. If this control function is used in hierarchical order, it may delimit a data item called a group. In this case the control function is named GROUP SEPARATOR (GS). + +NOTE – In accordance with ISO/IEC 10538 and ISO/IEC 6429, this control function is given two names. The name INFORMATION SEPARATOR THREE (IS3) is the general name. The name PAGE TERMINATOR (PT) is the specific name. The information separators in this Recommendation are used in hierarchical order. The ascending order is PT(IS3), DT(IS4). + +PAGE TERMINATOR (PT) delimits the text that is to be imaged on a given page and separates it from the text of the next page, if any, of the same document. The separator is either an occurrence of the control functions PT (IS3) or DOCUMENT TERMINATOR (DT) (INFORMATION SEPARATOR FOUR (IS4)) embedded in the text, or the equivalent function as a protocol element. + +This is an application-oriented use of control function IS3, as a page terminator function. It causes all representation attributes to be reset to the default state, causes any graphic character subrepertoire identification, as well as all non-default designations and invocations of graphic character sets to be cancelled, and causes the default character sets, if any, to be implicitly designated and invoked. Any such attribute, identification, etc. shall be (re)specified at the beginning of each page. + +## **12.56 INFORMATION SEPARATOR FOUR (IS4) [FILE SEPARATOR (FS)]** + +Notation: (C0) + +Representation: 01/12 + +IS4 is used to separate and qualify data logically; its specific meaning has to be defined for each application. If this control function is used in hierarchical order, it may delimit a data item called a file. In this case the control function is named FILE SEPARATOR (FS). + +NOTE – In accordance with ISO/IEC 10538 and ISO/IEC 6429, this control function is given two names. The name INFORMATION SEPARATOR FOUR (IS4) is the general name. The name DOCUMENT TERMINATOR (DT) is the specific name. The information separators in this Recommendation are used in hierarchical order. The ascending order is PT(IS3), DT(IS4). + +DOCUMENT TERMINATOR (DT) is used to indicate the end of the text on a document. This is an application-oriented use of control function IS4, as a document terminator function. In addition, it has the same effect as the control function PAGE TERMINATOR (PT), namely it causes all representation attributes to be reset to the default state, causes any graphic character subrepertoire identification, as well as all non-default designations and invocations of graphic character sets to be cancelled, and causes the default character sets, if any, to be implicitly designated and invoked. Any such attribute, identification, etc., shall be (re)specified at the beginning of each page. + +## 12.57 JUSTIFY (JFY) + +Notation: (Ps...) + +Representation: CSI Ps 02/00 04/06 + +Parameter default value: Ps = 0 + +JFY is used to indicate the beginning of a string of graphic characters in the presentation component that are to be justified according to the layout specified by the parameter values: + +- 0 No justification, end of justification of preceding text +- 1 Word fill +- 2 Word space +- 3 Letter space +- 4 Hyphenation +- 5 Flush to line home position margin +- 6 Center between line home position and the line limit position margins +- 7 Flush to line limit position margin +- 8 Italian hyphenation + +The end of the string to be justified is indicated by the next occurrence of JFY in the data stream. + +The line home position is established by the parameter value of SET LINE HOME (SLH). The line limit position is established by the parameter value of SET LINE LIMIT (SLL). + +NOTE – CCITT Rec. T.416 | ISO 8613-6 names this function “NO JUSTIFY” perhaps because the only allowed parameter value is the default value Ps = 0. + +## 12.58 LINE FEED (LF) + +Notation: (C0) + +Representation: 00/10 + +For devices with presentation component, LF causes the active presentation position to be moved to the corresponding character position of the following line in the presentation component. + +For devices with data component, LF causes the active data position to be moved to the corresponding character position of the following line in the data component. + +NOTE – The direction of the line progression depends on the parameter SELECT PRESENTATION DIRECTIONS (SPD), if any, prior to the most recent occurrence of FORM FEED (FF), or otherwise is from top-to-bottom. The amount of movement depends on the line spacing established by the most recent occurrence of SELECT LINE SPACING (SVS), if any, or otherwise is the default line spacing. + +## 12.59 LOCKING-SHIFT ZERO (LS0) + +Notation: (C0) + +Representation: 00/15 + +LS0 is used for code extension purposes. It causes the meanings of the bit combinations following it in the data stream to be changed. + +The use of LS0 is defined in ISO 2022. + +### NOTES + +- 1 LS0 is used in 8-bit environments only; in 7-bit environments SHIFT-IN (SI) is used instead. +- 2 LS0 invokes the currently designated G0 set into positions 02/01 to 07/14. + +## **12.60 LOCKING-SHIFT ONE (LS1)** + +Notation: (C0) + +Representation: 00/14 + +LS1 is used for code extension purposes. It causes the meanings of the bit combinations following it in the data stream to be changed. + +The use of LS1 is defined in ISO 2022. + +### NOTES + +- 1 LS1 is used in 8-bit environments only; in 7-bit environments SHIFT-OUT (SO) is used instead. +- 2 LS1 invokes the currently designated G1 set into positions 02/01 to 07/14. + +## **12.61 LOCKING-SHIFT ONE RIGHT (LS1R)** + +Notation: (Fs) + +Representation: ESC 07/14 + +LS1R is used for code extension purposes. It causes the meanings of the bit combinations following it in the data stream to be changed. + +The use of LS1R is defined in ISO 2022. + +### NOTES + +- 1 LS1R is used in 8-bit environments only. +- 2 LS1R invokes the currently designated G1 set into positions 10/01 to 15/14. + +## **12.62 LOCKING-SHIFT TWO (LS2)** + +Notation: (Fs) + +Representation: ESC 06/14 + +LS2 is used for code extension purposes. It causes the meanings of the bit combinations following it in the data stream to be changed. + +The use of LS2 is defined in ISO 2022. + +NOTE – LS2 invokes the currently designated G2 set into positions 02/01 to 07/14. + +## **12.63 LOCKING-SHIFT TWO RIGHT (LS2R)** + +Notation: (Fs) + +Representation: ESC 07/13 + +LS2R is used for code extension purposes. It causes the meanings of the bit combinations following it in the data stream to be changed. + +The use of LS2R is defined in ISO 2022. + +### NOTES + +- 1 LS2R is used in 8-bit environments only. +- 2 LS2R invokes the currently designated G2 set into positions 10/01 to 15/14. + +## **12.64 LOCKING-SHIFT THREE (LS3)** + +Notation: (Fs) + +Representation: ESC 06/15 + +LS3 is used for code extension purposes. It causes the meanings of the bit combinations following it in the data stream to be changed. + +The use of LS3 is defined in ISO 2022. + +NOTE – LS3 invokes the currently designated G3 set into positions 02/01 to 07/14. + +## **12.65 LOCKING-SHIFT THREE RIGHT (LS3R)** + +Notation: (Fs) + +Representation: ESC 07/12 + +LS3R is used for code extension purposes. It causes the meanings of the bit combinations following it in the data stream to be changed. + +The use of LS3R is defined in ISO 2022. + +NOTES + +- 1 LS3R is used in 8-bit environments only +- 2 LS3R invokes the currently designated G3 set into positions 10/01 to 15/14. + +## **12.66 NEGATIVE ACKNOWLEDGE (NAK)** + +Notation: (C0) + +Representation: 01/05 + +NAK is transmitted by a receiver as a negative response to the sender. + +The use of NAK is defined in ISO 1745. + +## **12.67 NO BREAK HERE (NBH)** + +Notation: (C1) + +Representation: ESC 04/03 (in 7-bit code) or 08/03 (in 8-bit code) + +NBH is used to indicate a point where a line break shall not occur when text is formatted. NBH may occur between two graphic characters either or both of which may be SPACE. + +## **12.68 NON-SELECTIVE RESET (NSR)** + +Notation: (C0) + +Representation: 01/15 + +NSR serves two functions. First, NSR resets non-selectively all the display attributes to their default states. Then, NSR sets the cursor position by the two-byte parameter immediately following NSR. The cursor positioning is the same as ACTIVE POSITION SET (APS), except that APS sets the cursor according to the current inter-character spacing and inter-row spacing, while NSR sets the cursor according to its default values. + +## **12.69 NULL (NUL)** + +Notation: (C0) + +Representation: 00/00 + +NUL is used for media-fill or time-fill. NUL characters may be inserted into, or removed from, a data stream without affecting the information content of that stream, but such action may affect the information layout and/or the control of equipment. + +## 12.70 PAGE FORMAT SELECTION (PFS) + +Notation: (Ps) + +Representation: CSI Ps 02/00 04/10 + +Parameter default value: Ps = 0 + +PFS is used to establish the available area for the imaging of text based on paper size. The pages are introduced by subsequent occurrences of FORM FEED (FF) in the data stream. + +The established image area remains in effect until the next occurrence of PFS in the data stream. + +The parameter values are: + +- 0 Tall basic text communication format +- 1 Wide basic text communication format +- 2 Tall basic A4 format +- 3 Wide basic A4 format +- 4 Tall North American letter format +- 5 Wide North American letter format +- 6 Tall extended A4 format +- 7 Wide extended A4 format +- 8 Tall North American legal format +- 9 Wide North American legal format +- 10 A4 short lines format +- 11 A4 long lines format +- 12 B5 short lines format +- 13 B5 long lines format +- 14 B4 short lines format +- 15 B4 long lines format + +### NOTES + +1 Dimensions and other properties of the text areas corresponding to the page formats specified by the parameter values of PFS are shown in Annex C. + +2 “Short lines” page formats have lines of text parallel to the shorter dimension of the text area; “long lines” page formats have lines of text parallel to the longer dimension of the text area. + +3 For the Teletex service the text areas corresponding to these page formats are defined in Recommendation T.60. + +TABLE 12-1/T.53 + +### Page orientation + +| PFS parameter value | Page orientation | | +|---------------------|---------------------------------------------------------|-------------------------------------------------------| +| | SPD (Ps1 = 0,3,5 or 6)<br>(horizontal line orientation) | SPD (Ps1 = 1,2,4 or 7)<br>(vertical line orientation) | +| 10, 12, 14 | Portrait | Landscape | +| 11, 13, 15 | Landscape | Portrait | + +## 12.71 PARTIAL LINE FORWARD (PLD) + +Notation: (C1) + +Representation: ESC 04/11 (in 7-bit code) or 08/11 (in 8-bit code) + +PLD causes the active presentation position to be moved in the presentation component to the corresponding position of an imaginary line with a partial offset in the direction of the line progression. This offset should be sufficient either to image following characters as subscripts until the first following occurrence of PARTIAL LINE BACKWARD (PLU) in the data stream, or, if preceding characters were imaged as superscripts, to restore imaging of following characters to the active line (the line that contains the active presentation position). + +If PLD is used to start a subscript image while the graphic rendition aspects “underlined” (singly or doubly) or “crossed out” specified by a parameter of SELECT GRAPHIC RENDITION (SGR) are in effect, the subscript image does not affect the line or the part of the line in which the relevant graphic rendition aspects are in use. + +### NOTES + +1 The subscript image initiated by PLD may be implemented by using special character fonts and/or by a movement of the active presentation position in the direction of the line progression, not exceeding a half line space. + +2 This Recommendation does not specify the use of PLD with parameter values of SELECT PRESENTATION DIRECTIONS (SPD) other than Ps1 = 0,3,5 or 6 (horizontal line orientation). When used in conjunction with other parameter values of SPD, PLD may be taken to cause a movement of the active presentation position not exceeding a half line space in the direction of the line progression. + +3 The control function LINE POSITION FORWARD (VPR) allows subscripting to be specified more precisely than is possible with PLD. + +## 12.72 PARTIAL LINE BACKWARD (PLU) + +Notation: (C1) + +Representation: ESC 04/12 (in 7-bit code) or 08/12 (in 8-bit code) + +PLU causes the active presentation position to be moved in the presentation component to the corresponding position of an imaginary line with a partial offset in the direction opposite to that of the line progression. This offset should be sufficient either to image following characters as superscripts until the first following occurrence of PARTIAL LINE FORWARD (PLD) in the data stream, or, if preceding characters were imaged as subscripts, to restore imaging of following characters to the active line (the line that contains the active presentation position). + +If PLU is used to start a superscript image while the graphic rendition aspects “underlined” (singly or doubly) or “crossed out” specified by a parameter of SELECT GRAPHIC RENDITION (SGR) are in effect, the superscript image does not affect the line or the part of the line in which the relevant graphic rendition aspects are in use. + +### NOTES + +1 The superscript image initiated by PLU may be implemented by using special character fonts and/or by a movement of the active presentation position in the direction opposite to that of the line progression, not exceeding a half line space. + +2 This Recommendation does not specify the use of PLU with parameter values of SELECT PRESENTATION DIRECTIONS (SPD) other than Ps1 = 0,3,5 or 6 (horizontal line orientation). When used in conjunction with other parameter values of SPD, PLU may be taken to cause a movement of the active presentation position not exceeding a half line space in the direction opposite to that of the line progression. + +3 The control function LINE POSITION BACKWARD (VPB) allows superscripting to be specified more precisely than is possible with PLU. + +## 12.73 PARALLEL TEXTS (PTX) + +Notation: (Ps) + +Representation: CSI Ps 05/12 + +Parameter default value: Ps = 0 + +PTX is used to delimit strings of graphic characters that are communicated one after another in the data stream but that are intended to be presented in parallel with one another, usually in adjacent lines. + +The parameter values are: + +- 0 End of parallel texts +- 1 Beginning of a string of principal parallel text +- 2 Beginning of a string of supplementary parallel text +- 3 Beginning of a string of supplementary Japanese phonetic annotation +- 4 Beginning of a string of supplementary Chinese phonetic annotation +- 5 End of a string of supplementary phonetic annotation + +PTX with a parameter value of 1 indicates the beginning of the principal text intended to be presented in parallel with one or more strings of supplementary text. + +PTX with a parameter value of 2, 3 or 4 indicates the beginning of a string of supplementary text that is intended to be presented in parallel with either a string of principal text or with the immediately preceding string of supplementary text, if any; at the same time it indicates the end of the preceding string of supplementary text, if any. The end of a string of supplementary text is indicated by a subsequent occurrence of PTX with a parameter value other than 1. + +PTX with a parameter value of 0 indicates the end of the strings of text intended to be presented in parallel with one another. + +### NOTES + +1 PTX does not explicitly specify the relative placement of the strings of principal and supplementary texts, or the relative sizes of graphic characters in the strings of parallel texts. A string of supplementary text is normally presented in a line adjacent to the line containing the string of principal text, or adjacent to the line containing the immediately preceding string of supplementary text, if any. The first graphic character of the string of principal text and the first graphic character of the string of supplementary text are normally presented in the same character position of their respective lines. However, a string of supplementary text longer (when presented) than the associated string of principal text may be centered on that string. In the case of long strings of text, such as the paragraphs in different languages, the strings may be presented in parallel columns, with their beginnings aligned with one another and the shorter of the paragraphs followed by an appropriate amount of “white space”. + +Japanese phonetic annotation typically consists of a few half-size or smaller Kana characters which indicate the pronunciation or interpretation of one or more Kanji characters and that are presented above those Kanji characters if the character path is horizontal, or to the right of them if the character path is vertical. + +Chinese phonetic annotation typically consists of a few Pinyin characters which indicate the pronunciation of one or more Hanzi characters and that are presented above those Hanzi characters. Alternatively, the Pinyin characters may be presented in the same line as the Hanzi characters and following the respective Hanzi characters. The Pinyin characters will then be presented within enclosing pairs of parenthesis. + +2 CCITT Recommendation T.416 | ISO 8613-6 provide for alignment of the trailing edges (beginnings) of parallel strings of text. PTX should not be used where such alternative facilities are available and adequate; it is intended primarily to cater for parallel texts consisting of only a few characters, but could be used for other purposes by systems that handle only simple character coded text – perhaps as a means of “signifying intent” to more sophisticated systems. + +3 Simple devices may present texts delimited by PTX in series rather than in parallel, with supplementary text(s) merely following the principal text, perhaps with graphic symbols representing PTX to provide visible delimiters, for example: {Kanji | Ruby} or + +| | | | | | +|-----------|----------|---------|---------------|---| +| { English | Français | Deutsch | Lingua latina | } | +| { thus | ainsi | so | sic | } | + +## 12.74 RECORDING DEVICE START (RDS) (used only in Recommendation T.101) + +Notation: (C1) + +Representation: ESC 03/06 + +RDS causes the associated recording device to start recording data subsequently received by the terminal. + +## **12.75 RECORDING DEVICE STOP (RDT)** (used only in Recommendation T.101) + +Notation: (C1) + +Representation: ESC 03/07 + +RDT causes the associated recording device to stop. + +## **12.76 RECORDING DEVICE WAIT (RDW)** (used only in Recommendation T.101) + +Notation: (C1) + +Representation: ESC 03/05 + +RDW causes the associated recording device to wait. + +## **12.77 REPEAT (REP)** + +Notation: (Pn) + +Representation: CSI Pn 06/02 (See Note) + +Parameter default value: Pn = 1 + +REP is used to indicate that the preceding character in the data stream, if it is a graphic character (represented by one or more bit combinations) including SPACE, is to be repeated n times, where n equals the value of Pn. If the character preceding REP is a control function or part of a control function, the effect of REP is not defined by this Recommendation. + +NOTE – Different Recommendations make use of control functions with similar functionality as REP, with similar names and acronyms, but different coding: Recommendation T.101, DS I defines RPC, and Recommendation T.101, DS II and DS III define RPT. + +## **12.78 REVERSE LINE FEED (RI)** + +Notation: (C1) + +Representation: ESC 04/13 (in 7-bit code) or 08/13 (in 8-bit code) + +For devices with presentation component, RI causes the active presentation position to be moved in the presentation component to the corresponding character position of the preceding line. + +For devices with data component, RI causes the active data position to be moved in the data component to the corresponding character position of the preceding line. + +The direction of the movement depends on the direction of the line progression established by the parameter value Ps1 of SELECT PRESENTATION DIRECTIONS (SPD). The amount of the movement depends on the line spacing selected by the most recent occurrence of SELECT LINE SPACING (SVS). + +NOTE – In the Teletex service in order to use RI, it is first necessary to negotiate the use of an optional supplementary control character set containing RI (in addition to the characters CSI, PLU and PLD shown in Figure 3/T.61 using the control procedures of Recommendation T.62). Designation and invocation of this control character set may appear at any position in the text. + +The escape sequence for this control set is ESC 02/02 F. The Final Byte is not yet assigned, since no identifiable use for RI could be found. The need for RI is for further study. + +## **12.79 REPEAT TO END OF LINE (ROL)** (used only in Recommendation T.101) + +Notation: (C1) + +Representation: ESC 04/07 (in 7-bit code) or 08/07 (in 8-bit code) + +This command causes the immediately preceding byte to be repeated until the last character position of the line, along the current character progression direction. This is reached if the byte is SPACE or any spacing character from the primary, supplementary, DRCS, or mosaic sets. Otherwise the command is in error and shall be executed as a NULL. + +## **12.80 REPEAT CONTROL (RPC) (used only in Recommendation T.101)** + +Notation: (C1) + +Representation: ESC 05/08 (in 7-bit code) or 09/08 (in 8-bit code) + +RPC causes the following transmitted G-set character, if the following character is a non-spacing character, both the non-spacing character and the next character, to be displayed as a number of times specified by the byte following it. The byte must be from columns 06-07. + +NOTE – This function, defined in Recommendation T.101 DS I, does not correspond to the REPEAT (REP) control function defined in ISO/IEC 6429 although they have similar names, but different acronyms, definitions, coding and functionality. + +## **12.81 REPEAT (RPT) (used only in Recommendation T.101)** + +Notation: (C0) + +Representation: 01/02 + +A format effector which causes the immediately preceding complete graphic character, including SPACE and DEL, to be displayed a number of times as defined by a parameter. + +NOTE – This function, defined in Recommendation T.101 DS II and DS III, does not correspond to the REPEAT (REP) control function defined in ISO/IEC 6429 although they have the same name, but different acronyms, definitions, coding and functionality. + +New Recommendations should use the REPEAT (REP) function. + +## **12.82 SET ADDITIONAL CHARACTER SEPARATION (SACS)** + +Notation: (Pn) + +Representation: CSI Pn 02/00 05/12 + +Parameter default value: Pn = 0 + +SACS is used to establish extra inter-character escapement for subsequent text. The established extra escapement remains in effect until the next occurrence of SACS or of SET REDUCED CHARACTER SEPARATION (SRCS) in the data stream or until it is reset to the default value by a subsequent occurrence of CARRIAGE RETURN / LINE FEED (CR/LF) in the data stream. + +Pn specifies the number of units by which the inter-character escapement is enlarged. + +The unit in which the parameter value is expressed is that established by the parameter value of SELECT SIZE UNIT (SSU). + +### **NOTES** + +1 CCITT Rec. T.416 | ISO 8613-6 specifies the parameter default value of SACS as Pn = 0 SMU. The measuring unit SMU (SCALED MEASUREMENT UNIT) is defined directly, without the function SELECT SIZE UNIT (SSU): its value is equal to the BMU times the unit scaling. + +2 ISO/IEC 10538 defines the measuring unit for SACS the BMU (BASIC MEASUREMENT UNIT), the value of which is 1/1200 of 25,4 mm. + +## **12.83 SELECT ALTERNATIVE PRESENTATION VARIANTS (SAPV)** + +Notation: (Ps...) + +Representation: CSI Ps... 02/00 05/13 + +Parameter default value: Ps = 0 + +SAPV is used to specify one or more variants for the presentation of subsequent text. + +The parameter values are: + +- 0 Default presentation (implementation defined); cancels the effect of any preceding occurrence of SAPV in the data stream. +- 1 The decimal digits are presented by means of graphic symbols used in the Latin script. +- 2 The decimal digits are presented by means of graphic symbols used in the Arabic script, i.e. the Hindi symbols. +- 3 When the direction of the character path is right-to-left, each of the graphic characters in the graphic character set(s) in use which is one of a left/right handed pair (parenthesis, square brackets, curly brackets, greater-than/less-than signs, etc.) is presented as “mirrored”, i.e. as the other member of the pair. For example, the coded graphic character given the name LEFT PARENTHESIS is presented as RIGHT PARENTHESIS, and vice versa. +- 4 When the direction of the character path is right-to-left, all graphic characters which represent operators and delimiters in mathematical formulae and which are not symmetrical about a vertical axis are presented as mirrored about that vertical axis. +- 5 The following graphic character is presented in its isolated form. +- 6 The following graphic character is presented in its initial form. +- 7 The following graphic character is presented in its medial form. +- 8 The following graphic character is presented in its final form. +- 9 Where the bit combination 02/14 is intended to represent a decimal mark in a decimal number it shall be presented by means of the graphic symbol FULL STOP. +- 10 Where the bit combination 02/14 is intended to represent a decimal mark in a decimal number it shall be presented by means of the graphic symbol COMMA. +- 11 Vowels are presented above or below the preceding character. +- 12 Vowels are presented after the preceding character. +- 13 Contextual shape determination of Arabic scripts, including the LAM-ALEPH ligature but excluding all other Arabic ligature. +- 14 Contextual shape determination of Arabic scripts, excluding all other Arabic ligature. +- 15 Cancels the effect of parameter values 3 and 4. +- 16 Vowels are not presented. +- 17 When the string direction is right-to-left, the italicized characters are slanted to the left; when the string direction is left-to-right, the italicized characters are slanted to the right. +- 18 Contextual shape determination of Arabic scripts is not used, the graphic characters – including the digits – are presented in the form they are stored (Passthrough). +- 19 Contextual shape determination of Arabic scripts is not used, the graphic characters – excluding the digits – are presented in the form they are stored (Passthrough). +- 20 The graphic symbols used to present the decimal digits are device dependent. +- 21 Establishes the effect of parameter values 5, 6, 7 and 8 for the following graphic characters until cancelled. +- 22 Cancels the effect of parameter value 21, i.e. re-establishes the effect of parameter values 5, 6, 7 and 8 for the next single graphic character only. + +## **12.84 SCROLL DOWN (SCD) (used only in Recommendation T.101)** + +Notation: (Pn) + +Representation: CSI 03/01 06/00 + +SCD causes a scrolling down of the designated scrolling area. The active position does not move relative to the defined display area. + +NOTE – This function, defined in Recommendation T.101 DS II, does not correspond to the SCROLL DOWN (SD) control function defined in ISO/IEC 6429 although they have the same name, but different acronyms, definitions, coding and functionality. + +New Recommendations should use the SCROLL DOWN (SD) function (Representation: CSI Pn 05/14). + +## **12.85 SCROLL OFF (SCF) (used only in Recommendation T.101)** + +Notation: (C1) + +Representation: ESC 05/08 (in 7-bit code) or 09/08 (in 8-bit code) + +SCROLL OFF, upon receiving APD, APU or an automatic APR APD that would advance any part of the data out of the display area, causes the data position to be repositioned within the text area such that the character field lies entirely within the area or field. + +NOTE – This coding of SCF is defined in Recommendation T.101 DS III. The same code position is used for example in T.101 DS I for REPEAT CONTROL (RPC), or in Recommendation T.416 for START OF STRING (SOS). + +## **12.86 SCROLL ON (SCN) (used only in Recommendation T.101)** + +Notation: (C1) + +Representation: ESC 05/07 (in 7-bit code) or 09/07 (in 8-bit code) + +SCROLL ON, upon receiving APD, APU or an automatic APR APD that would advance any part of the data out of the display area, causes the entire display within the area or field to be scrolled. + +## **12.87 SELECT CHARACTER ORIENTATION (SCO)** + +Notation: (Ps) + +Representation: CSI Ps 02/00 06/05 + +Parameter default value: Ps = 0 + +SCO is used to establish the amount of rotation of the graphic characters following in the data stream. The established value remains in effect until the next occurrence of SCO in the data stream. + +The parameter values are: + +| | | +|---|------| +| 0 | 0° | +| 1 | 45° | +| 2 | 90° | +| 3 | 135° | +| 4 | 180° | +| 5 | 225° | +| 6 | 270° | +| 7 | 315° | + +Rotation is positive, i.e. counter-clockwise and applies to the normal presentation of graphic characters along the character path. The center of rotation of the affected graphic characters is not defined by this Recommendation. + +The direction of the character path depends on the parameter of SELECT PRESENTATION DIRECTIONS (SPD), if any, or otherwise is left-to-right. + +NOTE – for Chinese ideogram terminals, the center of character rotation is the center of the character cell. + +## 12.88 SET CHARACTER SPACING (SCS) + +Notation: (Pn) + +Representation: CSI Pn 02/00 06/07 + +Parameter default value: None (See Note) + +SCS is used to establish the character spacing for subsequent text. The established spacing remains in effect until the next occurrence of SCS or of SELECT CHARACTER SPACING (SHS) in the data stream. + +Pn specifies the character spacing. The unit in which the parameter value is expressed is that established by the parameter value of SELECT SIZE UNIT (SSU). + +NOTE – CCITT Rec. T.416 | ISO 8613-6 specifies the parameter default value of SCS as Pn = 120 BMU. The measuring unit BMU (BASIC MEASUREMENT UNIT) which is 1/1200 of 25.4 mm, is defined directly, without the function SELECT SIZE UNIT (SSU). + +## 12.89 SCROLL UP (SCU) (used only in Recommendation T.101) + +Notation: (Pn) + +Representation: CSI 03/00 06/00 + +SCU causes a scrolling up of the designated scrolling area. The active position does not move relative to the defined display area. + +NOTE – This function, defined in Recommendation T.101 DS II, does not correspond to the SCROLL UP (SU) control function defined in ISO/IEC 6429 although they have the same name, but different acronyms, definitions, coding and functionality. + +New Recommendations should use the SCROLL UP (SU) function (Representation: CSI Pn 05/03). + +## 12.90 START DIRECTED STRING (SDS) + +Notation: (Ps) + +Representation: CSI Ps 05/13 + +Parameter default value: Ps = 0 + +SDS is used to establish in the data component the beginning and the end of a string of characters as well as the direction of the string. This direction may be different from that currently established. The indicated string follows the preceding text. + +The beginning of a directed string is indicated by SDS with parameter value not equal to 0. A directed string may contain one or more nested strings. These nested strings may be directed strings, the beginnings of which are indicated by SDS with a parameter value not equal to 0, or reversed strings the beginnings of which are indicated by START REVERSED STRING (SRS) with a parameter value of 1. Every beginning of such a string invokes the next deeper level of nesting (substring). + +This Recommendation does not define the location of the active data position within any such nested string. + +The end of a directed string is indicated by SDS with a parameter value of 0. Every end of such a string re-establishes the next higher level of nesting (the one in effect prior to the string just ended). The direction is re-established to that in effect prior to the string just ended. The active data position is moved to the character position following the characters of the string just ended. + +The parameter values are: + +- 0 End of a directed string; re-establish the previous direction +- 1 Start of a directed string; establish the direction left-to-right +- 2 Start of a directed string; establish the direction right-to-left + +NOTE – The effect of receiving HT or SPD control function within an SDS string is not defined by this Recommendation. + +## 12.91 SELECT GRAPHIC RENDITION (SGR) + +Notation: (Ps...) + +Representation: CSI Ps... 06/13 + +Parameter default value: Ps = 0 + +SGR is used to establish one or more graphic rendition aspects for subsequent text. The established aspects remain in effect until the next occurrence of SGR in the data stream. + +Each graphic rendition aspect is specified by a parameter value: + +- 0 Default rendition (implementation-defined), cancels the effect of any preceding occurrence of SGR in the data stream +- 1 Bold or increased intensity +- 2 Faint, decreased intensity or second colour +- 3 Italicized +- 4 Singly underlined +- 5 Slowly blinking (less than 150 per minute) +- 6 Rapidly blinking (150 per minute or more) +- 7 Negative image +- 8 Concealed characters +- 9 Crossed-out (characters still legible but marked as to be deleted) +- 10 Primary (default) font +- 11 First alternative font +- 12 Second alternative font +- 13 Third alternative font +- 14 Fourth alternative font +- 15 Fifth alternative font +- 16 Sixth alternative font +- 17 Seventh alternative font +- 18 Eighth alternative font +- 19 Ninth alternative font +- 20 Fraktur (Gothic) +- 21 Doubly underlined +- 22 Normal colour or normal intensity (neither bold nor faint) +- 23 Not italicized, not fraktur +- 24 Not underlined (neither singly nor doubly) +- 25 Steady (not blinking) +- 26 (Reserved for proportional spacing as specified in CCITT Recommendation T.61 – see also Note 6) +- 27 Positive image +- 28 Revealed characters +- 29 Not crossed out +- 30 Black display +- 31 Red display +- 32 Green display +- 33 Yellow display +- 34 Blue display +- 35 Magenta display +- 36 Cyan display +- 37 White display +- 38 (Reserved for future standardization; intended for setting character foreground colour as specified in CCITT Rec. T.416 | ISO 8613-6) +- 39 Default display colour (implementation-defined) +- 40 Black background +- 41 Red background +- 42 Green background +- 43 Yellow background +- 44 Blue background + +- 45 Magenta background +- 46 Cyan background +- 47 White background +- 48 (Reserved for future standardization; intended for setting character background colour as specified in CCITT Rec. T.416 | ISO 8613-6) +- 49 Default background colour (implementation-defined) +- 50 (Reserved for cancelling the effect of the rendering aspect established by parameter value 26) +- 51 Framed +- 52 Encircled +- 53 Overlined +- 54 Not framed, not encircled +- 55 Not overlined +- 56 (Reserved for future standardization) +- 57 (Reserved for future standardization) +- 58 (Reserved for future standardization) +- 59 (Reserved for future standardization) +- 60 Single line below character with horizontal line orientation or single line on the right side of character with vertical line orientation +- 61 Double line below character with horizontal line orientation or double line on the right side of character with vertical line orientation +- 62 Single line above character with horizontal line orientation or single line on the left side of character with vertical line orientation +- 63 Double line above character with horizontal line orientation or double line on the left side of character with vertical line orientation +- 64 Ideogram stress marking +- 65 Cancels the effect of the rendition aspects established by parameters 60 to 64 and 66 to 69 +- 66 Single line below character with horizontal line orientation or single line on the left side of character with vertical line orientation +- 67 Double line below character with horizontal line orientation or double line on the left side of character with vertical line orientation +- 68 Single line above character with horizontal line orientation or single line on the right side of character with vertical line orientation +- 69 Double line above character with horizontal line orientation or double line on the right side of character with vertical line orientation + +When SGR is used to start the graphic rendition aspects “underlined” (singly or doubly), or “crossed out”, while a subscript or a superscript image specified by PARTIAL LINE FORWARD (PLD), or PARTIAL LINE BACKWARD (PLU) is in effect, the relevant graphic rendition aspects also apply - in the appropriate form - to the subscript or the superscript image, respectively. + +### NOTES + +- 1 The usable combinations of parameter values are determined by the implementation. +- 2 Several parameter values can be used in combination in order to obtain, for example, the graphic rendition aspects “underlined italics”. The maximum number of parameter values is four. +- 3 The default parameter value cannot be used in combination with any other parameter value. +- 4 The parameter values 4 and 21 cannot be used in combination with each other. +- 5 The parameter values 10 to 19 cannot be used in combination with each other. +- 6 Parameter value 26 (as specified in CCITT Recommendation T.61) indicates that the text that follows may be presented with variable-spacing graphic symbols, if required by the recipient. When variable-spacing character pitch is invoked, the parameter value of SELECT CHARACTER SPACING (SHS) shall specify the nominal character pitch. For interworking with devices not capable of variable-spacing character pitch, a line or part of a line with variable-spacing graphic symbols should not contain more characters than are permitted by the currently effective pitch specified by the parameter value of the most recent occurrence of SHS. +- 7 This Recommendation does not specify the use of SGR in conjunction with parameter values of SELECT PRESENTATION DIRECTIONS (SPD) other than the default value. For text consisting of graphic characters ordered other than from left-to-right along the lines of the page images, it may be that some parameter values of SGR have no meaning or only a meaning analogous to but not identical with the meaning defined in this Recommendation. For example, Hebrew or Arabic script (written from right to left) might appear bold or with increased intensity and/or crossed out, but not italicized; for Japanese Kanji characters presented in vertical lines, the analogues of singly and doubly underlined may be taken to be straight and wavy vertical lines on the left of the highlighted characters. + +## 12.92 SELECT CHARACTER SPACING (SHS) + +Notation: (Ps) + +Representation: CSI Ps 02/00 04/11 + +Parameter default value: Ps = 0 + +SHS is used to establish the character spacing for subsequent text. The established spacing remains in effect until the next occurrence of SHS or of SET CHARACTER SPACING (SCS) in the data stream. + +The parameter values are: + +- | | | +|---|---------------------------| +| 0 | 10 characters per 25.4 mm | +| 1 | 12 characters per 25.4 mm | +| 2 | 15 characters per 25.4 mm | +| 3 | 6 characters per 25.4 mm | +| 4 | 3 characters per 25.4 mm | +| 5 | 9 characters per 50.8 mm | +| 6 | 4 characters per 25.4 mm | + +### NOTES + +1 The character spacing specified by the parameter values of SHS takes effect immediately. When it is required to specify the character spacing that will become effective with the beginning of a line, SHS should immediately precede the combination of CARRIAGE RETURN (CR) and LINE FEED (LF), or CR and FORM FEED (FF), that indicates the beginning of that line. + +2 SHS affects the active presentation position movement caused by subsequent occurrence of graphic characters including SPACE or of the control functions BACKSPACE (BS), or CHARACTER POSITION BACKWARD (HPB), or CHARACTER POSITION FORWARD (HPR). + +3 A change of character spacing may be taken to imply an appropriate change in the size of graphic characters for subsequent text. + +4 SHS with a parameter value of 0, 1, or 2 may be taken to imply that graphic characters are to be presented with their baseline parallel to the character path. + +5 SHS is relevant only for use with constant-spacing graphic characters. When variable-spacing graphic characters are to be used, their spacing along the line will depend on the font in use. This matter is outside the scope of this Recommendation and is implementation-dependent. + +6 CCITT Rec. T.416 | ISO 8613-6 defines the meaning of the parameter values as follows: + +- | | | +|---|----------| +| 0 | 120 BMUs | +| 1 | 100 BMUs | +| 2 | 80 BMUs | +| 3 | 200 BMUs | +| 4 | 400 BMUs | + +where BMU (BASIC MEASUREMENT UNIT) has the value of 1/1200 of 25.4 mm (0.02117 mm). + +## 12.93 SHIFT-IN (SI) + +Notation: (C0) + +Representation: 00/15 + +SI is used (in conjunction with SO and ESC) for code extension purposes. It causes the meanings of the bit combinations following it in the data stream to be changed. + +The use of SI is defined in ISO 2022. + +### NOTES + +- 1 SI is used in 7-bit environments only (in 8-bit environments LS0 is used instead). +- 2 SI invokes the currently designated G0 set into positions 02/01 to 07/14. + +## 12.94 SELECT IMPLICIT MOVEMENT DIRECTION (SIMD) + +Notation: (Ps) + +Representation: CSI Ps 05/14 + +Parameter default values: Ps = 0 + +SIMD is used to select the direction of the implicit movement of the data position relative to the character progression. The direction selected remains in effect until the next occurrence of SIMD. + +The parameter values are: + +- 0 The direction of implicit movement is the same as that of the character progression +- 1 The direction of implicit movement is opposite to that of the character progression. + +## 12.95 SET LINE HOME (SLH) + +Notation: (Pn) + +Representation: CSI Pn 02/00 05/05 + +Parameter default value: None + +For devices with presentation component only, SLH is used to establish at character position n in the active line (the line that contains the active presentation position) and lines of subsequent text in the presentation component the position to which the active presentation position will be moved by subsequent occurrences of CARRIAGE RETURN (CR) in the data stream; where n equals the value of Pn. In this case it is also the position ahead of which no implicit movement of the active presentation position shall occur. + +For devices with data component SLH is used to establish at character position n in the active line (the line that contains the active data position) and lines of subsequent text in the data component the position to which the active data position will be moved by subsequent occurrences of CARRIAGE RETURN (CR) in the data stream; where n equals the value of Pn. It is also the position ahead of which no implicit movement of the active data position shall occur. + +The established position is called the line home position and remains in effect until the next occurrence of SLH in the data stream. + +NOTE – Present Telematic services do not use this control function but other means to reach the same effect for uni-directional applications. This function is needed for bi-directional applications. + +## 12.96 SET LINE LIMIT (SLL) + +Notation: (Pn) + +Representation: CSI Pn 02/00 05/06 + +Parameter default value: None + +For devices with presentation component only, SLL is used to establish at character position n in the active line (the line that contains the active presentation position) and lines of subsequent text in the presentation component the position to which the active presentation position will be moved by subsequent occurrences of CARRIAGE RETURN (CR) in the data stream, if the parameter value of SELECT IMPLICIT MOVEMENT DIRECTION (SIMD) is equal to 1; where n equals the value of Pn. In this case it is also the position beyond which no implicit movement of the active presentation position shall occur. + +For devices with data component, SLL is used to establish at character position n in the active line (the line that contains the active data position) and lines of subsequent text in the data component the position beyond which no implicit movement of the active data position shall occur. It is also the position in the data component to which the active data position will be moved by subsequent occurrences of CARRIAGE RETURN (CR) in the data stream, if the parameter value of SELECT IMPLICIT MOVEMENT DIRECTION (SIMD) is equal to 1. + +The established position is called the line limit position and remains in effect until the next occurrence of SLL in the data stream. + +NOTE – Present Telematic services do not use this control function but other means to reach the same effect for uni-directional applications. This function is needed for bi-directional applications. + +## **12.97 SET LINE SPACING (SLS)** + +Notation: (Pn) + +Representation: CSI Pn 02/00 06/08 + +Parameter default value: None (See Note) + +SLS is used to establish the line spacing for subsequent text. The established spacing remains in effect until the next occurrence of SLS or of SELECT LINE SPACING (SVS) in the data stream. + +Pn specifies the line spacing. The unit in which the parameter value is expressed is that established by the parameter value of SELECT SIZE UNIT (SSU) + +NOTE – CCITT Rec. T.416 | ISO 8613-6 specifies the parameter default value of SLS as Pn = 200 BMU. The measuring unit BMU (BASIC MEASUREMENT UNIT) which is 1/1200 of 25.4 mm, is defined directly, without the function SELECT SIZE UNIT (SSU). + +## **12.98 SHIFT-OUT (SO)** + +Notation: (C0) + +Representation: 00/14 + +SO is used (in conjunction with SI and ESC) for code extension purposes. It causes the meanings of the bit combinations following it in the data stream to be changed. + +The use of SO is defined in ISO 2022. + +### **NOTES** + +- 1 SO is used in 7-bit environments only (in 8-bit environments LS1 is used instead). +- 2 SO invokes the currently designated G1 set into positions 02/01 to 07/14. + +## **12.99 START OF HEADING (SOH)** + +Notation: (C0) + +Representation: 00/01 + +SOH is used to indicate the beginning of a heading. + +The use of SOH is defined in ISO 1745. + +## **12.100 START OF STRING (SOS)** + +Notation: (C1) + +Representation: ESC 05/08 (in 7-bit code) or 09/08 (in 8-bit code) (See Note) + +SOS is used as the opening delimiter of a control string. The character string following may consist of a sequence of characters represented by any bit combination (in particular CR, LF introduced as a result of a formatting process), except those representing SOS or STRING TERMINATOR (ST). The control string is closed by the terminating delimiter ST. The interpretation of the character string depends on the application. + +NOTE – This coding of SOS is used in CCITT Recommendation T.416. The same coding is used in T.101 DS I for REPEAT CONTROL (RPC), and in T.101 DS III for SCROLL OFF (SCF). + +## 12.101 SPACE (SP) + +Notation: (Cx) + +Representation: 02/00 + +In this Recommendation, SP has the properties of both a graphic character and a control function. + +As a logical control function, SP acts as a word delimiter and indicates a potential line breaking point, except when it is immediately followed by another SP or by an occurrence of NO BREAK HERE (NBH). Any SPs that precede a line terminating control function and follow the last graphic character of that line, shall be ignored in processing. + +As a graphic character, SP has a visual representation consisting of the absence of a graphic symbol. However, any graphic rendition aspect that is in effect, i.e. “underlined” also applies to SP. SP causes the active data position to advance by one character position in the direction of the character progression. + +NOTE – SP, as per revised CCITT Rec. T.50 | ISO 646, is considered exclusively a non-printing graphic character (therefore not included in ISO/IEC 6429). The reason of maintaining it in this Recommendation is only for backward compatibility. The use of SP as a control function is deprecated. It is foreseen to remove SP from the next edition of this Recommendation. + +## 12.102 SELECT PRESENTATION DIRECTIONS (SPD) + +Notation: (Ps1;Ps2) + +Representation: CSI Ps1 Ps2 02/00 05/03 + +Parameter default values: Ps1 = 0; Ps2 = 0 + +SPD is used to select the line orientation, the line progression, and the character path in the presentation component. It is also used to update the content of the presentation component and the content of the data component. This takes effect immediately. + +Ps1 specifies the line orientation, the line progression and the character path: + +- | | | | +|---|--------------------|---------------| +| 0 | Line orientation : | horizontal | +| | Line progression: | top-to-bottom | +| | Character path : | left-to-right | +| 1 | Line orientation : | vertical | +| | Line progression: | right-to-left | +| | character path : | top-to-bottom | +| 2 | Line orientation : | vertical | +| | Line progression: | left-to-right | +| | Character path : | top-to-bottom | +| 3 | line orientation : | horizontal | +| | Line progression: | top-to-bottom | +| | Character path : | right-to-left | +| 4 | Line orientation : | vertical | +| | Line progression: | left-to-right | +| | Character path : | bottom-to-top | +| 5 | Line orientation : | horizontal | +| | Line progression: | bottom-to-top | +| | Character path : | right-to-left | +| 6 | Line orientation : | horizontal | +| | Line progression: | bottom-to-top | +| | Character path : | left-to-right | +| 7 | Line orientation : | vertical | +| | Line progression: | right-to-left | +| | Character path : | bottom-to-top | + +Ps2 specifies the effect on the content of the presentation component and the content of the data component: + +- 0 Undefined (implementation-dependent) + +NOTE – This may also permit the effect to take place after the next occurrence of CR, FF, or any control function which initiates an absolute movement of the active presentation position or the active data position. + +- 1 The content of the presentation component is updated to correspond to the content of the data component according to the newly established characteristics of the presentation component; the active data position is moved to the first character position in the first line in the data component, the active presentation position is updated accordingly +- 2 The content of the data component is updated to correspond to the content of the presentation component according to the newly established characteristics of the presentation component; the active presentation position is moved to the first character position in the first line in the presentation component, the active data position is updated accordingly. + +## 12.103 SET REDUCED CHARACTER SEPARATION (SRCS) + +Notation: (Pn) + +Representation: CSI Pn 02/00 06/06 + +Parameter default value: Pn = 0 + +SRCS is used to establish reduced inter-character escapement for subsequent text. The established reduced escapement remains in effect until the next occurrence of SRCS or of SET ADDITIONAL CHARACTER SEPARATION (SACS) in the data stream or until it is reset to the default value by a subsequent occurrence of CARRIAGE RETURN/LINE FEED (CR/LF) in the data stream. + +Pn specifies the number of units by which the inter-character escapement is reduced. The unit in which the parameter values are expressed is that established by the parameter value of SELECT SIZE UNIT (SSU). + +### NOTES + +1 CCITT Rec. T.416 | ISO 8613-6 specifies the parameter default value of SRCS as Pn = 0 SMU. The measuring unit SMU (SCALED MEASUREMENT UNIT) is defined directly, without the function SELECT SIZE UNIT (SSU): its value is equal to the BMU times the unit scaling. + +2 ISO/IEC 10538 defines the measuring unit for SRCS the BMU (BASIC MEASUREMENT UNIT), the value of which is 1/1200 of 25.4 mm. + +## 12.104 START REVERSED STRING (SRS) + +Notation: (Ps) + +Representation: CSI Ps 05/11 + +Parameter default value: Ps = 0 + +SRS is used to establish in the data component the beginning and the end of a string of characters as well as the direction of the string. This direction is opposite to that currently established. The indicated string follows the preceding text. + +The beginning of a reversed string is indicated by SRS with a parameter value of 1. A reversed string may contain one or more nested strings. These nested strings may be reversed strings, the beginnings of which are indicated by SRS with a parameter value of 1, or directed strings the beginnings of which are indicated by START DIRECTED STRING (SDS) with a parameter value not equal to 0. Every beginning of such a string invokes the next deeper level of nesting. + +This Recommendation does not define the location of the active data position within any such nested string. + +The end of a reversed string is indicated by SRS with a parameter value of 0. Every end of such a string re-establishes the next higher level of nesting (the one in effect prior to the string just ended). The direction is re-established to that in effect prior to the string just ended. The active data position is moved to the character position following the characters of the string just ended. + +The parameter values are: + +- 0 End of a reversed string; re-establish the previous direction +- 1 Beginning of a reversed string; reverse the direction. + +NOTE – The effect of receiving an HT or SPD control function within an SRS string is not defined by this Recommendation. + +## 12.105 SELECT SIZE UNIT (SSU) + +Notation: (Ps) + +Representation: CSI Ps 02/00 04/09 + +Parameter default value: Ps = 0 + +SSU is used to establish the unit in which the numeric parameters of certain control functions are expressed. The established unit remains in effect until the next occurrence of SSU in the data stream. + +The parameter values are: + +- 0 CHARACTER – The dimensions of this unit are device-dependent +- 1 MILLIMETRE +- 5 BASIC MEASURING UNIT (BMU) – 0,02117 mm (1/1200 of 25.4 mm) +- 7 PIXEL – The smallest increment that can be specified in a device + +NOTES + +- 1 CCITT Rec. T.416 | ISO 8613-6 does not use this control function; instead, it defines directly the measuring unit BMU. +- 2 ISO/IEC 10538 defines SSU, but with the parameter default value Ps = 5 (which is the BMU). + +## 12.106 SET SPACE WIDTH (SSW) + +Notation: (Pn) + +Representation: CSI Pn 02/00 05/11 + +Parameter default value: None + +SSW is used to establish for subsequent text the character escapement associated with the character SPACE. The established escapement remains in effect until the next occurrence of SSW in the data stream or until it is reset to the default value by a subsequent occurrence of CARRIAGE RETURN / LINE FEED (CR/LF) or CARRIAGE RETURN / FORM FEED (CR/FF) in the data stream. + +Pn specifies the escapement. The unit in which the parameter value is expressed is that established by the parameter value of SELECT SIZE UNIT (SSU). + +The default character escapement of SPACE is specified by the most recent occurrence of SET CHARACTER SPACING (SCS) or of SELECT CHARACTER SPACING (SHS) in the data stream if the current font has constant spacing, or is specified by the nominal width of the character SPACE in the current font if that font has proportional spacing. + +NOTE – CCITT Rec. T.416 | ISO 8613-6 specifies for the measuring unit the SMU (SCALED MEASUREMENT UNIT) which is defined directly, without the function SELECT SIZE UNIT (SSU): its value is equal to the BMU times the unit scaling (the value of BMU is 1/1200 of 25.4 mm). + +## 12.107 SINGLE-SHIFT TWO (SS2) + +Notation: (C1) + +Representation: ESC 04/14 (in 7-bit code) or 08/14 (in 8-bit code) (see Note) + +SS2 is used for code extension purposes. SS2 causes the bit combination following it in the data stream to be interpreted according to the currently designated G2 set. + +In the case where the characters of the G2 set are represented by more than one bit combination, SS2 changes the interpretation of the relevant number of following bit combinations. + +The bit combination following SS2 shall be one from 02/00 to 07/15. + +The use of SS2 is defined in ISO 2022. + +NOTE – Recommendations T.101 and T.61 specify for SS2 the representation 01/09. + +## **12.108 SINGLE-SHIFT THREE (SS3)** + +Notation: (C1) + +Representation: ESC 04/15 (in 7-bit code) or 08/15 (in 8-bit code) (see Note) + +SS3 is used for code extension purposes. SS3 causes the bit combination following it in the data stream to be interpreted according to the currently designated G3 set. + +In the case where the characters of the G3 set are represented by more than one bit combination, SS3 changes the interpretation of the relevant number of following bit combinations. + +The bit combination following SS3 shall be one from 02/00 to 07/15. + +The use of SS3 is defined in ISO 2022. + +NOTE – Recommendations T.101 and T.61 specify for SS3 the representation 01/13. + +## **12.109 STRING TERMINATOR (ST)** + +Notation: (C1) + +Representation: ESC 05/12 (in 7-bit code) or 09/12 (in 8-bit code) + +ST is used as the closing delimiter of a control string opened by START OF STRING (SOS). + +## **12.110 SELECTIVE TABULATION (STAB)** + +Notation: (Ps) + +Representation: CSI Ps 02/00 05/14 + +Parameter default value: None + +STAB causes subsequent text in the presentation component to be aligned according to the position and the properties of a tabulation stop which is selected from a list according to the value of parameter Ps. + +The use of this control function and means of specifying a list of tabulation stops to be referenced by the control function are specified in other Recommendations, for example CCITT Rec. T.416 | ISO 8613-6. + +## **12.111 START OF TEXT (STX)** + +Notation: (C0) + +Representation: 00/02 + +STX is used to indicate the beginning of a text and the end of a heading. + +The use of STX is defined in ISO 1745. + +## **12.112 SUBSTITUTE (SUB)** + +Notation: (C0) + +Representation: 01/10 + +SUB is used in the place of a character that has been found to be invalid or in error. SUB is intended to be introduced by automatic means. + +NOTE – This Recommendation does not specify a graphical representation for the SUB character. + +## 12.113 SELECT LINE SPACING (SVS) + +Notation: (Ps) + +Representation: CSI Ps 02/00 04/12 + +Parameter default value: Ps = 0 + +SVS is used to establish the line spacing for subsequent text. The established spacing remains in effect until the next occurrence of SVS or of SET LINE SPACING (SLS) in the data stream. + +The parameter values are: (See Note 3) + +- | | | +|---|----------------------| +| 0 | 6 lines per 25.4 mm | +| 1 | 4 lines per 25.4 mm | +| 2 | 3 lines per 25.4 mm | +| 3 | 12 lines per 25.4 mm | +| 4 | 8 lines per 25.4 mm | +| 5 | 6 lines per 30.0 mm | +| 6 | 4 lines per 30.0 mm | +| 7 | 3 lines per 30.0 mm | +| 8 | 12 lines per 30.0 mm | +| 9 | 2 lines per 25.4 mm | + +### NOTES + +1 SVS affects the active presentation position movements caused by subsequent occurrences of LINE FEED (LF), or of LINE POSITION FORWARD (VPR). + +2 When text contains both ideographic and non-ideographic characters, the line spacing should be selected so as to accommodate the ideographic characters. + +3 CCITT Rec. T.416 | ISO 8613-6 defines the meaning of the parameter values as follows: + +- | | | +|---|----------| +| 0 | 200 BMUs | +| 1 | 300 BMUs | +| 2 | 400 BMUs | +| 3 | 100 BMUs | +| 4 | 150 BMUs | +| 9 | 600 BMUs | + +where BMU (BASIC MEASUREMENT UNIT) has the value of $1/1200$ of 25.4 mm (0.02117 mm). + +## 12.114 SYNCHRONOUS IDLE (SYN) + +Notation: (C0) + +Representation: 01/06 + +SYN is used by a synchronous transmission system in the absence of any other character (idle condition) to provide a signal from which synchronism may be achieved or retained between data terminal equipment. + +The use of SYN is defined in ISO 1745. + +## 12.115 LINE POSITION BACKWARD (VPB) + +Notation: (Pn) + +Representation: CSI Pn 06/11 + +Parameter default value: Pn = 1 + +VPB causes the active data position to be moved by n line positions in the data component in a direction opposite to that of the line progression, where n equals the value of Pn. + +The unit in which the parameter value is expressed is that established by the parameter value of SELECT SIZE UNIT (SSU); if the unit is CHARACTER, the amount of movement is specified by the most recent occurrence of SET LINE SPACING (SLS) or of SELECT LINE SPACING (SVS), if any, or otherwise is the default line spacing. + +The direction of the line progression depends on the parameter of SELECT PRESENTATION DIRECTIONS (SPD), if any, or otherwise is from top-to-bottom. + +NOTE – CCITT Rec. T.416 | ISO 8613-6 defines the parameter default value of VPB as the equivalent of 100 BMUs, where BMU (BASIC MEASUREMENT UNIT) has the value of 1/1200 of 25.4 mm (0.02117 mm). + +Also it mentions that the main purpose of VPB is to provide for positioning of parallel annotation and for explicit control for the positioning of superscripts. + +## **12.116 LINE POSITION FORWARD (VPR)** + +Notation: (Pn) + +Representation: CSI Pn 06/05 + +Parameter default value: Pn = 1 + +VPR causes the active data position to be moved by n line positions in the data component in a direction parallel to the line progression, where n equals the value of Pn. + +The unit in which the parameter value is expressed is that established by the parameter value of SELECT SIZE UNIT (SSU); if the unit is CHARACTER, the amount of movement is specified by the most recent occurrence of SET LINE SPACING (SLS) or of SELECT LINE SPACING (SVS), if any, or otherwise is the default line spacing. + +The direction of the line progression depends on the parameter of SELECT PRESENTATION DIRECTIONS (SPD), if any, or otherwise is from top-to-bottom. + +NOTE – CCITT Rec. T.416 | ISO 8613-6 defines the parameter default value of VPR as the equivalent of 100 BMUs, where BMU (BASIC MEASUREMENT UNIT) has the value of 1/1200 of 25.4 mm (0.02117 mm). + +Also it mentions that the main purpose of VPR is to provide for positioning of parallel annotation and for explicit control for the positioning of subscripts. + +## **12.117 WORD WRAP OFF (WWF)** + +Notation: (C1) + +Representation: ESC 05/06 (in 7-bit code) or 09/06 (in 8-bit code) + +WORD WRAP OFF causes the receiving device to exit the word wrap mode. + +## **12.118 WORD WRAP ON (WWN)** + +Notation: (C1) + +Representation: ESC 05/05 (in 7-bit code) or 09/05 (in 8-bit code) + +WORD WRAP ON causes the receiving device to enter the word wrap mode. In this mode, subsequently received alphanumeric text is buffered into words. + +# **Annex A** + +## **Table of registered control sets** + +(This annex forms an integral part of this Recommendation) + +This annex lists the various registered control sets available in ITU-T Recommendations and their invocation functions. + +NOTE – This listing is contained also in Annex B/T.51, together with the registered character sets. + +The control sets C0 and C1 are invoked using the following sequences: + +C0 ESC 02/01 F + +C1 ESC 02/02 F + +where + +F is the Final Byte which identifies the control set. + +| Reg. No. | Name of registered set | | Final Byte | C0 | C1 | +|-------------------------------------------------------------------------------------------|--------------------------------|------------------------------------------------------|--------------|----------|----------| +| 1 | Rec. T.50, | Primary control set | 04/00 | X | | +| 132 | Rec. T.101, | Data Syntax I<br>Primary control set | 04/09 | X | | +| 125 | Rec. T.101, | Data Syntax I<br>Supplementary control set | 04/04 | | X | +| 134 | Rec. T.101, | Data Syntax II<br>Primary control set | 04/10 | X | | +| 56 | Rec. T.101, | Data Syntax II<br>Serial supplementary control set | 04/00 | | X | +| 73 | Rec. T.101 | Data Syntax II<br>Parallel supplementary control set | 04/01 | | X | +| 135 | Rec. T.101, | Data Syntax III<br>Primary control set | 04/11 | X | | +| 136 | Rec. T.101, | Data Syntax III<br>Supplementary control set | 04/06 | | X | +| 106 | Rec. T.61, | Primary control set | 04/05 | X | | +| 107 | Rec. T.61, | Supplementary control set | 04/08 | | X | +| <u>1</u> | <u>ISO/IEC 6429</u> | | <u>04/00</u> | <u>X</u> | | +| 77 | <u>ISO/IEC 6429</u> (see Note) | | <u>04/03</u> | | <u>X</u> | +| NOTE – This C1 set can be designated also by the escape sequence <u>ESC 02/06 04/00</u> . | | | | | | + +# Annex B + +## Bi-directional text (BDT) model + +(This annex forms an integral part of this Recommendation) + +## B.1 General + +This annex describes a model for handling bi-directional text as described in detail in the Technical Report ECMA TR/53. + +The description of the model is regarding the handling of bi-directional text from the point of view of presentation and content directionality but in order to show the context the full bidirectional device model is shown and explained. + +A basic example from the report is given to illustrate the working of the model. + +### B.1.1 Telematic services basic device profile + +This Recommendation defines a basic device profile for Telematic applications. In addition to the unidirectional device concept which was considered before a bidirectional device – for the present – with presentation component only is now assumed. This basic solution for this new profile allows for the easiest transition to bidirectionality being derived from the existing “unidirectional” Telematic services. + +The minimum set of control functions to be used for bidirectionality is as follows: + +| | | +|------|------------------------------------------| +| SAPV | SELECT ALTERNATIVE PRESENTATION VARIANTS | +| SDS | START DIRECTED STRING | +| SPD | SELECT PRESENTATION DIRECTIONS | +| SRS | START REVERSED STRING | +| SIMD | SELECT IMPLICIT MOVEMENT DIRECTION | + +Of this list, only SIMD is a new control function to be introduced to Telematic services. The definitions of the other functions already contained in different Telematic services have been aligned to ISO/IEC 6429. Accordingly, all references to the active data position, the data component, character progression, etc. are referring to the active presentation position, the presentation component, character path, etc. respectively, considering this basic device profile. + +This initial introduction of bidirectionality does not prevent future developments of Telematic services to make use of the full bidirectional device concept with both a presentation component and a data component to achieve a higher level of bidirectional support. In this case additional device profiles will be included within this Recommendation. + +## **B.2 Requirements for handling bi-directional text** + +Many languages, like those using the Latin script, are written and read from left-to-right. Other ones, such as Arabic or Hebrew, are written and read from right-to-left. Numbers, in these languages, are written and read from left-to-right. Furthermore, texts of languages with opposite presentation directions can be intermixed. As a result, bi-directional character-imaging devices should provide support for: + +- both left-to-right and right-to-left presentation directions; +- text with embedded (nested) sections with left-to-right and right-to-left presentation directions. + +### **B.2.1 Direction of strings** + +Many graphic characters have an inherent directionality. Others have no inherent directionality and abide by context. Examples of such characters are: space, punctuation marks, separators, parenthesis, a.s.o. + +In order to fully specify the directionality of a string of text constituted of graphic characters with and without inherent directionality, control functions need to be embedded in the text string. + +Another requirement is to support some presentation variants which depend on the direction of the presented text string: italicized characters, for instance, are right-slanting for strings running from left-to-right, and left slanting for strings running from right-to-left. + +### **B.2.2 Ordering of data** + +The order in which the graphic characters in a string of bi-directional text (data stream) are interchanged may differ from the order in which the graphic characters are presented in the graphic image output. For example, “hello” may be presented as “olleh” on a right-to-left device. + +Such cases, and all their consequences must be handled as part of a bi-directional support. + +### **B.2.3 Transparency** + +Applications that are designed to handle bi-directional data streams can fully control the functionality of a bi-directional device. Such applications are called “bi-directionality-aware” applications. + +On the other hand, there is a need to allow applications not designed to handle bi-directional data streams to function reasonably well in a bi-directional environment, making this environment “transparent” to the application. Such applications are called “bi-directionality-unaware” applications. + +## **B.3 The bi-directional device model** + +To explain the requirements for and the methods of handling bi-directional texts, a device model is defined in this Recommendation. This model was also used to extend the uni-directional device concepts supported until now by Telematic services. + +Different devices complying with the model are represented schematically in Figures B.1, B.2 and B.3. + +A character-imaging device, according to this bi-directional device model is a device which is capable of receiving a data stream consisting of graphic characters and control functions and which is capable of producing a graphic image output from the received information. The graphic image output must be readable by a human being according to the applicable traditional writing conventions such as left-to-right, right-to-left, top-to-bottom and bottom-to-top. The graphic image output is, in general, produced in the form of one or more rectangular arrays of character positions and lines which are called pages. + +In addition to receiving a data stream, a character-imaging device may also be capable of transmitting a data stream consisting of graphic characters and control functions. The transmitted data stream is, in general, composed of a combination of data which have been sent to the device and data which have been entered locally into the device, for example by an associated keyboard. + +### **B.3.1 The device structure** + +A uni-directional device as referred to in this Recommendation is shown in Figure B.1. + +A bi-directional device as described in this model consists of either + +- an input component, a data component, a presentation component and a graphic image output as shown in Figure B.2, or +- an input component, a presentation component only, and a graphic image output as shown in Figure B.3. + +#### **B.3.1.1 The input component** + +The input component is used for receiving the data stream. In addition, the input component may receive data from a manual input device such as a keyboard or a mouse. + +This Recommendation does not deal with the input component. + +#### **B.3.1.2 The data component** + +The data component is used to store the data stream received from the input component and to make it available to a presentation process that transforms the data stream for the presentation component for subsequent graphic image output. A data component is generally not provided in uni-directional devices. + +The data component structures the information in successive lines; each line consisting of successive character positions. + +The lines in the data component convey the organizational aspects of the information. In the data component lines have no orientation; to simplify matters their orientation is considered to be horizontal only. + +The sequential order of the lines is called the line progression. In the data component the line progression is considered to be from top-to-bottom only. The lines are counted in the direction of the line progression and are numbered consecutively by the numbers 1, 2, 3, .... + +The sequential order of the character positions along a line in the data component is called the character progression. The character progression is considered to be from left-to-right only. The character positions along a line are counted in the direction of the character progression and are numbered consecutively by the numbers 1, 2, 3, .... + +At any time, there is a unique character position in the data component which is available for the next graphic character or relative to which certain control functions are to be executed. This character position is called the active data position. The active data position can be moved implicitly or explicitly or indirectly. + +The line in the data component containing the active data position is called the active data line, the field in the data component containing the active data position is called the active data field, the area in the data component containing the active data position is called the active data area, the page in the data component containing the active data position is called the active data page. + +Each character position, either is in the erased state or contains a graphic character, or a control function. The initial state of all character positions is “erased”. Depending on the implementation, there may or may not be a distinction between a character position in the erased state and a character position containing SPACE. + +#### **B.3.1.3 The presentation component** + +The presentation component is used for receiving the information from the data component through the presentation process and for producing the graphic image output. This output may, for example, be rendered on a display or a printer. A presentation component is provided in bi-directional as well as in uni-directional devices. + +The presentation component structures the information into successive lines; each line consisting of successive character positions. + +The lines in the presentation component convey the graphic image output aspects and their orientation can be considered to be either horizontal or vertical. This Recommendation deals only with horizontal line orientation. + +The sequential order of the lines is called the line progression. The lines are counted in the direction of the line progression and are numbered consecutively by the numbers 1, 2, 3, .... For horizontal line orientation the direction of the line progression can be considered to be either from top-to-bottom or from bottom-to-top. This Recommendation deals only with the line progression from top-to-bottom. + +The sequential order of the character positions along a line in the presentation component is called the character path. For horizontal line orientation the character path can be either from left-to-right or from right-to-left. The character positions along a line are counted in the direction of the character path and are numbered consecutively by the numbers 1, 2, 3, .... + +At any time, there is a unique character position in the presentation component which is available for the next graphic character or relative to which certain control functions are to be executed. This character position is called the active presentation position. The active presentation position can be moved implicitly or indirectly. In the case where a device has no data component, the active presentation position can also be moved explicitly. It is common practice to mark the active presentation position in a graphic image output by a special visible indicator called the cursor. + +The line in the presentation component containing the active presentation position is called the active presentation line, the field in the presentation component containing the active presentation position is called the active presentation field, the area in the presentation component containing the active presentation position is called the active presentation area, the page in the presentation component containing the active presentation position is called the active presentation page. + +#### **B.3.1.4 The graphic image output** + +The graphic image output is regarded as being produced in the form of a continuous stream, but eventually may be made available character-by-character, line-by-line, or page-by-page. + +The graphic image output usually consists of pages that are composed of a predetermined number of lines. The lines are composed of a predetermined number of character positions. The size of a character position may be fixed or may depend on the graphic symbol of the character being imaged. + +In the case of a character-imaging device with a data component and a presentation component, the graphic image output is created in the presentation component by the presentation process from the information in the data component. + +In the case of a character-imaging device with a presentation component only, the graphic image output is created in the presentation component from the information in the input component. + +### **B.3.2 Relationship between the active data position and the active presentation position** + +The relation between the active data position and the active presentation position depends on whether the device is a uni-directional one or a bi-directional one and whether it has both a data and a presentation component or a presentation component only. + +In a uni-directional device, no distinction can be made between an active data position and an active presentation position; they are considered to be equivalent and are referred to as active position only. + +In the case where a bi-directional device has a presentation component only, all references to the data component, to the active data position, to the character progression, etc., are to be considered as if they were references to the presentation component, to the active presentation position, to the character path, etc. + +In a bi-directional device with a data component and a presentation component, the active presentation position is the character position in the presentation component that corresponds to the active data position in the data component. Because the direction of the character progression (in the data component) may be different from the direction of the character path (in the presentation component) in particular bi-directional applications, the coordinates of the active data position in the data component and the active presentation position in the presentation component may also be different. + +Some control functions act on and affect the active data position, while other control functions act on and affect the active presentation position. Examples of such functions are: character insertion, character erasure, reference point movements, etc. When one of the active positions is moved, the other is subjected to a corresponding displacement, although not necessarily in the same direction. This displacement is referred to as indirect movement of the “other” position. + +### **B.3.3 Movement of the active positions** + +As a result of the content of the received data stream, the active data position as well as the active presentation position can be moved in their corresponding components. The movement can be implicit, explicit or indirect. + +#### **B.3.3.1 Implicit movement** + +An implicit movement is a movement of the active data position in the data component which is performed after receiving a graphic character or after receiving a control function for which a graphical representation is required. + +In unidirectional devices the direction of the implicit movement of the active data position in the data component is the same as the direction of the character progression; in devices without a data component the implicit movement applies to the active presentation position in the presentation component and is then the same as the direction of the character path. In bi-directional devices, the direction of the implicit movement may be different from the direction of the character progression. The direction is the same as the direction of the character progression until it is modified by an appropriate control function. + +If the direction of the implicit movement is the same as that of the character progression and the active data position is not the last character position (line limit position) of the active line, the active data position is moved to the following character position of that line. + +If the direction of the implicit movement is the opposite to that of the character progression and the active data position is not the first character position (line home position) of the active line, the active data position is moved to the preceding character position of that line. + +When the active data position, has been modified by an implicit movement, the active presentation position in the presentation component is updated accordingly; this is referred to as indirect movement. + +In a bi-directional device without a data component the implicit movement applies to the active presentation position in the presentation component and is then the same as the direction of the character path. + +NOTE – In the following situations, the effect of an attempt to move the active data position is not defined by this Recommendation: + +- an attempt to perform an implicit movement when the active data position is the last character position (line limit position) of a line and the direction of the implicit movement is the same as that of the character progression; or +- when the active data position is the first character position (line home position) of a line and the direction of the implicit movement is opposite to that of the character progression. + +#### **B.3.3.2 Explicit movement** + +In the data component an explicit movement is a movement the active data position that is performed when a control function is executed which causes the active data position to be moved to a specified character position in the data component. When the active data position has been modified by an explicit movement, the active presentation position in the presentation component is updated accordingly; this is referred to as indirect movement. + +In the presentation component an explicit movement is a movement of the active presentation position that is performed when a control function is executed which causes the active presentation position to be moved to a specified character position in the data component. When the active presentation position has been modified by an explicit movement, the active data position in the data component is updated accordingly; this is referred to as indirect movement. + +NOTE – In the following situations, the effect of an attempt to move the active data position or the active presentation position is not defined by this Recommendation: + +- an attempt to perform an explicit movement to a non-existing character position, for example beyond the last character position (line limit position) of a line; or +- beyond the last line of a page, i.e. beyond the page limit position. + +#### B.3.3.3 Indirect movement + +In the data component, an indirect movement is the movement by which of the active data position is modified to reflect modification of the active presentation position by an explicit movement in the presentation component. + +In the presentation component, an indirect movement is the movement by which the active presentation position is modified to reflect a modification of the active data position by an implicit movement or by an explicit movement in the data component. + +### B.3.4 Data stream and data organization + +The data stream is considered to be a continuous stream. It may be structured in messages, records and/or blocks, but that does not affect the operation of the character-imaging device at the abstract level of description in this Recommendation. + +The text in a data stream can be viewed as being constructed from character strings. Each such string may contain nested strings. The graphic characters in the strings are organized in the order in which they are intended to be read by a human being. + +Each string has a direction associated with it. This association may be accomplished by using an appropriate control function or by using a higher-level protocol. If the direction of a string is not determined in this way, the direction is taken to be the same as that of the currently established character path. + +### B.3.5 Simplified presentation of the device model + +See Figures B.1, B.2 and B.3. + +![Diagram of a Uni-directional device model showing the flow from Data stream to Input component, then through Active position, Character path, Implicit movement, and Explicit movement, finally to Image output.](6e0ac4070edc6a056713e6f0a3222db5_img.jpg) + +The diagram illustrates the Uni-directional device model. A 'Data stream' (represented by two parallel arrows) enters from the left into the 'Input component'. The 'Input component' is a vertical rectangle containing the text 'I n p u t c o m p o n e n t' (with spaces between letters). To the right of the 'Input component' is a large rectangle labeled 'Device'. Inside the 'Device' rectangle, the text 'Active position', 'Character path', 'Implicit movement', and 'Explicit movement' are listed vertically. To the right of the 'Device' rectangle is a vertical rectangle labeled 'I m a g e o u t p u t' (with spaces between letters). A line connects the top of the 'Input component' to the top of the 'Image output' rectangle, passing through the 'Device' rectangle. + +T0812820-93/d01 + +Diagram of a Uni-directional device model showing the flow from Data stream to Input component, then through Active position, Character path, Implicit movement, and Explicit movement, finally to Image output. + +FIGURE B.1/T.53 +Uni-directional device + +![Diagram of a bi-directional device with data and presentation components.](fd8f5da2b60cdca94896f3cde8ee81f0_img.jpg) + +The diagram illustrates a bi-directional device architecture. A horizontal line at the top is labeled "Device". Below this line, the device is divided into three main sections: "Data component", "Presentation component", and a central "Presentation process" block. On the left, a "Data stream" (represented by two parallel arrows) enters the "Data component". The "Data component" is a large rectangle containing a vertical bar on its left labeled "Input component" and a list of items: "Active data position", "Character progression", "Implicit movement", "Explicit movement", and "Indirect movement". An arrow points from the "Data component" to the "Presentation process" block, which is a vertical rectangle labeled "Presentation process". Another arrow points from the "Presentation process" block to the "Presentation component". The "Presentation component" is a large rectangle containing a vertical bar on its right labeled "Image output" and a list of items: "Active presentation position", "Character path", "Explicit movement", and "Indirect movement". A feedback line connects the top of the "Presentation component" back to the "Data component". + +T0812830-93/d02 + +Diagram of a bi-directional device with data and presentation components. + +FIGURE B.2/T.53 +Bi-directional device with data and presentation component + +![Diagram of a bi-directional device with only a presentation component.](fef7e3f08b408e4ab937a75f5c8b6bfc_img.jpg) + +The diagram illustrates a bi-directional device architecture where the data and presentation components are integrated. A horizontal line at the top is labeled "Device". Below this line, the device is divided into two main sections: "Input component" and "Image output". The "Input component" is a vertical bar on the left, and the "Image output" is a vertical bar on the right. Between them is a large rectangle labeled "Presentation component" containing the following text: "Active presentation position = active data position", "Character path = character progression", "Implicit movement", and "Explicit movement". A "Data stream" (represented by two parallel arrows) enters the "Input component". + +T0812840-93/d03 + +Diagram of a bi-directional device with only a presentation component. + +FIGURE B.3/T.53 +Bi-directional device with presentation component only + +### B.3.6 Character path and character progression + +Example illustrating the relationship between character path and character progression: + +*Data Component:* + +| | | | | | | | | | | | | | | | +|-------------------------|---|---|---|---|---|---|---|---|---|----|----|----|----|----| +| character progression : | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | +| characters : | a | b | c | d | _ | E | F | G | H | _ | i | j | k | l | +| directionality : | R | R | R | R | R | L | L | L | L | R | R | R | R | R | +| nesting level : | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | + +*Graphic image output for horizontal left-to-right lines:* + +![Diagram showing character progression and path for horizontal left-to-right lines. The character progression is 14 to 1, and the character path is 1 to 14. The characters are arranged in a box from left to right: l, k, j, i, -, E, F, G, H, -, d, c, b, a.](a47713c2491e6ce619259ed2f196fd24_img.jpg) + +14 13 12 11 10 9 8 7 6 5 4 3 2 1 → Character progression + +| | | | | | | | | | | | | | | +|---|---|---|---|---|---|---|---|---|---|---|---|---|---| +| l | k | j | i | - | E | F | G | H | - | d | c | b | a | +|---|---|---|---|---|---|---|---|---|---|---|---|---|---| + +1 2 3 4 5 6 7 8 9 10 11 12 13 14 → Character path + +Diagram showing character progression and path for horizontal left-to-right lines. The character progression is 14 to 1, and the character path is 1 to 14. The characters are arranged in a box from left to right: l, k, j, i, -, E, F, G, H, -, d, c, b, a. + +*Graphic image output for horizontal right-to-left lines:* + +![Diagram showing character progression and path for horizontal right-to-left lines. The character progression is 14 to 1, and the character path is 14 to 1. The characters are arranged in a box from left to right: l, k, j, i, -, E, F, G, H, -, d, c, b, a.](3e20f0289a1945c7c3894f51383d8e37_img.jpg) + +14 13 12 11 10 9 8 7 6 5 4 3 2 1 → Character progression + +| | | | | | | | | | | | | | | +|---|---|---|---|---|---|---|---|---|---|---|---|---|---| +| l | k | j | i | - | E | F | G | H | - | d | c | b | a | +|---|---|---|---|---|---|---|---|---|---|---|---|---|---| + +14 13 12 11 10 9 8 7 6 5 4 3 2 1 ← Character path + +Diagram showing character progression and path for horizontal right-to-left lines. The character progression is 14 to 1, and the character path is 14 to 1. The characters are arranged in a box from left to right: l, k, j, i, -, E, F, G, H, -, d, c, b, a. + +## B.4 Control functions for handling bi-directionality in Telematic services – Bi-directional devices with presentation component only + +| | | +|------|------------------------------------------| +| BS | BACKSPACE | +| CR | CARRIAGE RETURN | +| LF | LINE FEED | +| RI | REVERSE LINE FEED | +| SAPV | SELECT ALTERNATIVE PRESENTATION VARIANTS | +| SIMD | SELECT IMPLICIT MOVEMENT DIRECTION | +| SPD | SELECT PRESENTATION DIRECTIONS | +| SDS | START DIRECTED STRING | +| SRS | START REVERSED STRING | + +## **B.5 Levels of device support for bi-directionality** + +Because of the diversity of application and device requirements, different levels of bi-directional support may be considered. For the present, this Recommendation specifies a bi-directional device with presentation component only. In the future, bi-directional devices with presentation component and data component will be also included. + +# **Annex C** + +## **Text area formats** + +(This annex does not form an integral part of this Recommendation) + +The purpose of this annex is to provide supplementary information for the control function PAGE FORMAT SELECTION (PFS) defined in 12.70. + +## **C.1 Dimension of the text area** + +Table C.1 shows the dimensions of the text area corresponding to various values of the parameters of PFS. + +### **NOTES** + +1 When determining the number of lines per page for the parameter values 0 to 9, account is taken of any additional space needed for an optional “call identification line” (see Recommendation T.60). This space is not included in the text area. + +2 This annex does not specify the number of lines per page for line spacing of 6 per 30.0 mm used in conjunction with the North American page formats, or for line spacing of 2 or 12 lines per 25.4 mm or 3, 4 or 12 lines per 30.0 mm used in conjunction with any of the page formats. + +3 This annex does not specify the number of characters per line for spacing of 10 or 15 characters per 25.4 mm used in conjunction with page formats specified by PFS with parameter values 10 to 15, or for spacing of 3 characters per 25.4 mm used in conjunction with page formats specified by PFS with parameters values 0 to 9. + +## **C.2 Line home position** + +For the page formats specified by PFS with parameter values 0 to 9 and 10 to 15, the line home position is, depending on the character spacing, as shown in Table C.2. + +### **NOTES** + +1 For the page formats specified by PFS with parameter values 0 to 9, the line home position is specified so as to provide a margin of approximately 20 mm between the line home position and the edge of the paper. + +2 For the page formats specified by PFS with parameter values 10 to 15, the line home position is specified so as to provide a margin of approximately 25 mm between the line home position and the edge of the paper. + +TABLE C.1/T.53 + +### **Dimensions of the text area (for Teletex service)** + +| PFS<br><br>Ps | Meaning | Dimension | Number of lines per page<br>for spacing of | | | | | Number of characters<br>per line for spacing of | | | | | +|---------------|-------------------------------|-----------|--------------------------------------------|----|----|----|----------------------|-------------------------------------------------|----|-----|-----|-----| +| | | | 8 | 6 | 4 | 3 | 6<br>per<br>30<br>mm | 3 | 6 | 10 | 12 | 15 | +| | | | per 25.4 mm | | | | | per 25.4 mm | | | | | +| 0 | Tall basic text communication | | 73 | 55 | 37 | 28 | 46 | | 46 | 77 | 92 | 115 | +| 1 | Wide basic text communication | | 50 | 38 | 25 | 19 | 32 | | 62 | 105 | 125 | 156 | +| 2 | Tall basic A4 | | 78 | 59 | 39 | 30 | 49 | | 46 | 77 | 92 | 115 | +| 3 | Wide basic A4 | | 50 | 38 | 25 | 19 | 32 | | 66 | 110 | 132 | 165 | +| 4 | Tall North American letter | | 74 | 56 | 37 | 28 | | | 48 | 80 | 96 | 120 | +| 5 | Wide North American letter | | 53 | 40 | 27 | 20 | | | 62 | 105 | 125 | 156 | +| 6 | Tall extended A4 | ISO 3535 | 88 | 66 | 44 | 33 | 55 | | 46 | 77 | 92 | 115 | +| 7 | Wide extended A4 | ISO 3535 | 58 | 44 | 29 | 22 | 36 | | 66 | 110 | 132 | 165 | +| 8 | Tall North American legal | | 98 | 74 | 49 | 37 | | | 48 | 80 | 96 | 120 | +| 9 | Wide North American legal | | 53 | 40 | 27 | 20 | | | 80 | 135 | 161 | 201 | +| 10 | A4 short lines | | | 59 | 39 | 30 | | 22 | 45 | | 89 | | +| 11 | A4 long lines | | | 38 | 25 | 19 | | 32 | 66 | | 131 | | +| 12 | B4 short lines | | | 49 | 33 | 24 | | 18 | 38 | | 75 | | +| 13 | B5 long lines | | | 32 | 21 | 16 | | 27 | 56 | | 111 | | +| 14 | B4 short lines | | | 75 | 50 | 38 | | 27 | 56 | | 111 | | +| 15 | B4 long lines | | | 49 | 33 | 25 | | 39 | 79 | | 157 | | + +TABLE C.2/T.53 + +### **Line home position** + +| PFS<br>parameter value | Characters<br>per 25.4 mm | Line home<br>position | Line limit<br>position | +|------------------------|---------------------------|-----------------------|------------------------| +| 0 to 9 | 6 | 4 | | +| | 10 | 6 | | +| | 12 | 7 | | +| | 15 | 8 | | +| 10 to 15 | 3 | 3 | | +| | 6 | 5 | | +| | 12 | 9 | | + +# **Annex D** + +## **Cross reference table** + +(This annex does not form an integral part of this Recommendation) + +The cross reference table contains the location in specific Recommendations of the control functions defined in this Recommendation. For control functions with similar functionality (or application-dependent implementation) but with different names, and/or notations, and/or coded representation, that similar control function is mentioned in the column of the Recommendation(s) it appears in. + +| Acronym | Name | Recommendation | | | | | | | +|---------|-----------------------------|---------------------|-----|------|---------------|----------------|-----------------|-------| +| | | ISO/<br>IEC<br>6429 | T.4 | T.61 | T.101<br>DS I | T.101<br>DS II | T.101<br>DS III | T.416 | +| ACK | ACKNOWLEDGE | x | | | | | x | | +| ADF | AUXILIARY DEVICE OFF | | | | | x | | | +| ADO | AUXILIARY DEVICE ON | | | | | x | | | +| AIS | ACTIVATE IMPLICIT SCROLLING | | | | | x | | | +| APA | ACTIVE POSITION ADDRESSING | | | | NSR | x | NSR | | +| APB | ACTIVE POSITION BACKWARD | | | BS | x | x | x | HPB | +| APD | ACTIVE POSITION DOWN | | | LF | x | x | x | VPR | +| APF | ACTIVE POSITION FORWARD | | | | x | x | x | HPR | +| APH | ACTIVE POSITION HOME | | | | x | x | x | | +| APR | ACTIVE POSITION RETURN | | | CR | x | x | x | | +| APS | ACTIVE POSITION SET | | | | x | | x | | +| APU | ACTIVE POSITION UP | | | | x | x | x | VPB | + +| Acronym | Name | Recommendation | | | | | | | +|---------|-------------------------------------|---------------------|-----|------|---------------|----------------|-----------------|-------| +| | | ISO/<br>IEC<br>6429 | T.4 | T.61 | T.101<br>DS I | T.101<br>DS II | T.101<br>DS III | T.416 | +| BEL | BELL | x | | | x | | x | | +| BPH | BREAK PERMITTED HERE | x | | | | | | x | +| BS | BACKSPACE | x | | x | APB | APB | APB | x | +| CAN | CANCEL | x | | | x | x | x | | +| COF | CURSOR OFF | DC4 | | | | x | | | +| CON | CURSOR ON | DC1 | | | | x | | | +| CR | CARRIAGE RETURN | x | x | x | APR | APR | APR | x | +| CS | CLEAR SCREEN | FF | | FF | x | x | x | | +| CSI | CONTROL SEQUENCE INTRODUCER | x | x | x | | x | | x | +| DC1 | DEVICE CONTROL ONE | x | | | x | CON | x | | +| DC2 | DEVICE CONTROL TWO | x | | | x | | x | | +| DC3 | DEVICE CONTROL THREE | x | | | x | | x | | +| DC4 | DEVICE CONTROL FOUR | x | | | x | COF | x | | +| DDF | DISPLAY DEVICE OFF | | | | | x | | | +| DDO | DISPLAY DEVICE ON | | | | | x | | | +| DEL | DELETE ( <i>see 12.28, Note 2</i> ) | | | | | x | | | +| DIS | DEACTIVATE IMPLICIT SCROLLING | | | | | x | | | +| DLE | DATA LINK ESCAPE | x | | | | | x | | +| DT | DOCUMENT TERMINATOR | IS4 | | | | | | | +| EBU | EMPTY BUFFER | | | | | x | | | +| EDC1 | EXTENDED DEVICE CONTROL ONE | | | | | | x | | +| EDC2 | EXTENDED DEVICE CONTROL TWO | | | | | | x | | +| EDC3 | EXTENDED DEVICE CONTROL THREE | | | | | | x | | +| EDC4 | EXTENDED DEVICE CONTROL FOUR | | | | | | x | | +| ENQ | ENQUIRY | x | | | | | x | | +| EOT | END OF TRANSMISSION | x | | | | | x | | +| ESC | ESCAPE | x | x | x | x | x | x | x | +| ETB | END OF TRANSMISSION BLOCK | x | | | | | x | | +| ETX | END OF TEXT | x | | | | | x | | +| FF | FORM FEED | x | x | x | CS | CS | CS | | + +| Acronym | Name | Recommendation | | | | | | | +|---------|--------------------------------------|---------------------|-----|------|---------------|----------------|-----------------|-------| +| | | ISO/<br>IEC<br>6429 | T.4 | T.61 | T.101<br>DS I | T.101<br>DS II | T.101<br>DS III | T.416 | +| FNT | FONT SELECTION | x | | | | x | | | +| FS | FILE SEPARATOR | IS4 | | | | | | | +| GCC | GRAPHIC CHARACTER <u>COMBINATION</u> | x | | | | | | x | +| GS | GROUP SEPARATOR | IS3 | | | | | | | +| GSM | GRAPHIC SIZE MODIFICATION | x | | x | | | | | +| GSS | GRAPHIC SIZE <u>SELECTION</u> | x | | | | | | | +| HCS | HARD COPY START | | | | | x | | | +| HCT | HARD COPY STOP | | | | | x | | | +| HCW | HARD COPY WAIT | | | | | x | | | +| HPB | CHARACTER POSITION BACKWARD | x | | BS | APB | APB | APB | x | +| HPR | CHARACTER POSITION FORWARD | x | | SP | APF | APF | APF | x | +| HT | CHARACTER TABULATION | x | x | | | | | | +| IGS | IDENTIFY GRAPHIC SUBREPERTOIRE | x | | x | | | | x | +| IS1 | INFORMATION SEPARATOR ONE | x | | | NSR | US | NSR | | +| IS2 | INFORMATION SEPARATOR TWO | x | | | APH | APH | APH | | +| IS3 | INFORMATION SEPARATOR THREE | x | | | | | | | +| IS4 | INFORMATION SEPARATOR FOUR | x | | | APS | | APS | | +| JFY | JUSTIFY | x | | | | | | x | +| LF | LINE FEED | x | x | x | APD | APD | APD | x | +| LS0 | LOCKING-SHIFT ZERO | x | | x | | x | x | x | +| LS1 | LOCKING-SHIFT ONE | x | | x | | x | x | x | +| LS1R | LOCKING-SHIFT ONE RIGHT | x | | x | | x | x | x | +| LS2 | LOCKING-SHIFT TWO | x | | x | | x | x | x | +| LS2R | LOCKING-SHIFT TWO RIGHT | x | | x | | x | x | x | +| LS3 | LOCKING-SHIFT THREE | x | | x | | x | x | x | +| LS3R | LOCKING-SHIFT THREE RIGHT | x | | x | | x | x | x | + +| Acronym | Name | Recommendation | | | | | | | +|---------|------------------------------------------|---------------------|-----|------|---------------|----------------|-----------------|-------| +| | | ISO/<br>IEC<br>6429 | T.4 | T.61 | T.101<br>DS I | T.101<br>DS II | T.101<br>DS III | T.416 | +| NAK | NEGATIVE ACKNOWLEDGE | x | | | | | x | | +| NBH | NO BREAK HERE | x | | | | | | x | +| NSR | NON-SELECTIVE RESET | | | | x | APA | x | | +| NUL | NULL | x | | | x | | x | | +| PFS | PAGE FORMAT SELECTION | x | | x | | | | | +| PLD | PARTIAL LINE FORWARD | x | | x | | | | x | +| PLU | PARTIAL LINE BACKWARD | x | | x | | | | x | +| PT | PAGE TERMINATOR | IS3 | | | | | | | +| PTX | PARALLEL TEXTS | x | | | | | | x | +| RDS | RECORDING DEVICE START | | | | | x | | | +| RDT | RECORDING DEVICE STOP | | | | | x | | | +| RDW | RECORDING DEVICE WAIT | | | | | x | | | +| REP | REPEAT | x | | | RPC | RPT | RPT | | +| RI | REVERSE LINE FEED | x | | x | | | | | +| ROL | REPEAT TO END OF LINE | | | | | | x | | +| RPC | REPEAT CONTROL | REP | | | x | RPT | RPT | | +| RPT | REPEAT | REP | | | RPC | x | x | | +| RS | RECORD SEPARATOR | IS2 | | | | | | | +| SACS | SET ADDITIONAL CHARACTER SEPARATION | x | | | | | | x | +| SAPV | SELECT ALTERNATIVE PRESENTATION VARIANTS | x | | | | x | | | +| SCD | SCROLL DOWN | SD | | | | x | | | +| SCF | SCROLL OFF | | | | | | x | | +| SCN | SCROLL ON | | | | | | x | | +| SCO | SELECT CHARACTER ORIENTATION | x | | x | | | | | +| SCS | SET CHARACTER SPACING | x | | | | | | x | +| SCU | SCROLL UP | SU | | | | x | | | +| SDS | START DIRECTED STRING | x | | x | | x | x | | +| SGR | SELECT GRAPHIC RENDITION | x | x | x | | x | | x | + +| Acronym | Name | Recommendation | | | | | | | +|---------|------------------------------------|---------------------|-----|------|---------------|----------------|-----------------|-------| +| | | ISO/<br>IEC<br>6429 | T.4 | T.61 | T.101<br>DS I | T.101<br>DS II | T.101<br>DS III | T.416 | +| SHS | SELECT CHARACTER SPACING | x | | x | | x | | x | +| SI | SHIFT-IN | x | | | x | x | x | x | +| SIMD | SELECT IMPLICIT MOVEMENT DIRECTION | x | | | | | | | +| SLH | SET LINE HOME | x | | | | | | | +| SLL | SET LINE LIMIT | x | | | | | | | +| SLS | SET LINE SPACING | x | | | | | | x | +| SO | SHIFT-OUT | x | | | x | x | x | x | +| SOH | START OF HEADING | x | | | | | x | | +| SOS | START OF STRING | x | | | | | | x | +| SP | SPACE (see 12.101, Note) | | | x | | | | x | +| SPD | SELECT PRESENTATION DIRECTIONS | x | | x | | x | x | | +| SRCS | SET REDUCED CHARACTER SEPARATION | x | | | | | | x | +| SRS | START REVERSED STRING | x | | | | x | | x | +| SSU | SELECT SIZE UNIT | x | | | | | | | +| SSW | SET SPACE WIDTH | x | | | | | | x | +| SS2 | SINGLE-SHIFT TWO | x | x | x | x | x | x | x | +| SS3 | SINGLE-SHIFT THREE | x | | x | x | x | x | x | +| ST | STRING TERMINATOR | x | | | | | | x | +| STAB | SELECTIVE TABULATION | x | | | | | | x | +| STX | START OF TEXT | x | | | | | x | | +| SUB | SUBSTITUTE | x | | x | | | | x | +| SVS | SELECT LINE SPACING | x | | x | | | | x | +| SYN | SYNCHRONOUS IDLE | x | | | | | x | | +| US | UNIT SEPARATOR | IS1 | | | | x | | | +| VPB | LINE POSITION BACKWARD | x | | | APU | APU | APU | x | +| VPR | LINE POSITION FORWARD | x | | | APD | APD | APD | x | +| WWF | WORD WRAP OFF | | | | | | x | | +| WWN | WORD WRAP ON | | | | | | x | | \ No newline at end of file diff --git a/marked/T/T-REC-T.55-200806-I_PDF-E/e8ba5d4a3a22e24e44f7935ea26afcb0_img.jpg b/marked/T/T-REC-T.55-200806-I_PDF-E/e8ba5d4a3a22e24e44f7935ea26afcb0_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..d5a35041124e73f88d6638cd17f42a2eb4f6781a --- /dev/null +++ b/marked/T/T-REC-T.55-200806-I_PDF-E/e8ba5d4a3a22e24e44f7935ea26afcb0_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:8f24b214263bab4142643453a604fb5196f9397e2500c675cde79d53ce5e5d8e +size 3645 diff --git a/marked/T/T-REC-T.55-200806-I_PDF-E/raw.md b/marked/T/T-REC-T.55-200806-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..06dac81f0348034e9d70b3e50c51ea685c2ebdbc --- /dev/null +++ b/marked/T/T-REC-T.55-200806-I_PDF-E/raw.md @@ -0,0 +1,125 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**T.55** + +(06/2008) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES +Character coding + +# --- **Use of the universal multiple-octet coded character set (UCS)** + +Recommendation ITU-T T.55 + +## ITU-T T-SERIES RECOMMENDATIONS TERMINALS FOR TELEMATIC SERVICES + +| | | +|-----------------------------------------------------|------------------| +| Facsimile – Framework | T.0–T.19 | +| Still-image compression – Test charts | T.20–T.29 | +| Facsimile – Group 3 protocols | T.30–T.39 | +| Colour representation | T.40–T.49 | +| <b>Character coding</b> | <b>T.50–T.59</b> | +| Facsimile – Group 4 protocols | T.60–T.69 | +| Telematic services – Framework | T.70–T.79 | +| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89 | +| Telematic services – ISDN Terminals and protocols | T.90–T.99 | +| Videotext – Framework | T.100–T.109 | +| Data protocols for multimedia conferencing | T.120–T.149 | +| Telewriting | T.150–T.159 | +| Multimedia and hypermedia framework | T.170–T.189 | +| Cooperative document handling | T.190–T.199 | +| Telematic services – Interworking | T.300–T.399 | +| Open document architecture | T.400–T.429 | +| Document transfer and manipulation | T.430–T.449 | +| Document application profile | T.500–T.509 | +| Communication application profile | T.510–T.559 | +| Telematic services – Equipment characteristics | T.560–T.649 | +| Still-image compression – JPEG 2000 | T.800–T.849 | +| Still-image compression – JPEG-1 extensions | T.850–T.899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **Recommendation ITU-T T.55** + +## **Use of the universal multiple-octet coded character set (UCS)** + +## **Summary** + +Recommendation ITU-T T.55 recommends that for the representation, transmission, interchange, processing, storage, and presentation of written form of the languages of the world, as well as additional symbols, the universal multiple-octet coded character set (UCS) specified in ISO/IEC 10646 be used. + +### **Source** + +Recommendation ITU-T T.55 was approved on 13 June 2008 by ITU-T Study Group 16 (2005-2008) under Recommendation ITU-T A.8 procedure. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at <http://www.itu.int/ITU-T/ipr/>. + +© ITU 2008 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +# **Recommendation ITU-T T.55** + +## **Use of the universal multiple-octet coded character set (UCS)** + +ITU-T recommends that for the representation, transmission, interchange, processing, storage and presentation of the written forms of the languages of the world as well as additional symbols, the universal multiple-octet coded character set (UCS) specified in ISO/IEC 10646:2003 "*Information technology – Universal Multiple-Octet Coded Character Set (UCS)*" be used. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|---------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| <b>Series T</b> | <b>Terminals for telematic services</b> | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.564-199303-I_PDF-E/raw.md b/marked/T/T-REC-T.564-199303-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..9b8ab9b2d52ad6f88a928d551100a827f7a3cf80 --- /dev/null +++ b/marked/T/T-REC-T.564-199303-I_PDF-E/raw.md @@ -0,0 +1,1413 @@ + + +![ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, and a lightning bolt striking the globe. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## T.564 + +(03/93) + +**TELEMATIC SERVICES** + +**TERMINAL EQUIPMENTS AND PROTOCOLS +FOR TELEMATIC SERVICES** + +--- + +**GATEWAY CHARACTERISTICS +FOR VIDEOTEX INTERWORKING** + +**ITU-T Recommendation T.564** + +(Previously "CCITT Recommendation") + +--- + +# FOREWORD + +The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecommunication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +ITU-T Recommendation T.564 was revised by the ITU-T Study Group VIII (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). + +# --- NOTES + +1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector. + +In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms “CCITT, CCIR or IFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. + +2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# CONTENTS + +| | <i>Page</i> | +|--------------------------------------------------------------------|-------------| +| 1 Introduction ..... | 1 | +| 2 Scope and field of application ..... | 1 | +| 2.1 National videotex services ..... | 1 | +| 2.2 Videotex interworking definition ..... | 1 | +| 2.3 Relation to other Recommendations ..... | 1 | +| 3 References ..... | 1 | +| 4 Definitions ..... | 2 | +| 5 Abbreviations ..... | 3 | +| 6 Model of the communication between local and external host ..... | 3 | +| 6.1 International videotex interworking between gateways ..... | 3 | +| 6.2 Position of videotex interworking relative to OSI ..... | 4 | +| 6.3 Organization of the videotex interworking ..... | 4 | +| 7 Relation between videotex and DTAM service ..... | 5 | +| 8 Use of lower layer services ..... | 6 | +| 9 General structure of the VIA ..... | 6 | +| 9.1 General data structure ..... | 6 | +| 9.2 Attributes ..... | 7 | +| 9.3 General VIA operation ..... | 8 | +| 10 Videotex structure ..... | 8 | +| 10.1 Display structure ..... | 9 | +| 10.2 Data entry structure ..... | 10 | +| 10.3 Administrative structure ..... | 26 | +| 10.4 Special terminal facilities structure ..... | 28 | +| Annex A – Layout structure and operational structure ..... | 30 | +| Annex B – Minimum size of data structures ..... | 30 | + + + +# GATEWAY CHARACTERISTICS FOR VIDEOTEX INTERWORKING + +(Melbourne, 1988; amended at Helsinki, 1993) + +# 1 Introduction + +This Recommendation specifies gateway characteristics which should be used for international videotex interworking between gateways. + +This Recommendation is a part of a set of standards produced to facilitate the interconnection of national videotex services. This set of standards is positioned with respect to the open systems interconnection basic reference model (see Recommendation X.200). This Recommendation lies within the field of application layer of the OSI application layer. Inside the application layer it makes use of DTAM (document transfer, access and manipulation) specific application service element (see Recommendation T.400). + +# 2 Scope and field of application + +This Recommendation applies to the international videotex interworking between gateways as specified in this clause. + +## 2.1 National videotex services + +It is the responsibility of Administrations to decide the configuration of the national videotex services. + +## 2.2 Videotex interworking definition + +*Videotex interworking* allows a videotex terminal pertaining to a given videotex service of a given country to interact in real time with a videotex host computer located in a different country. This videotex host may be either a videotex center or an external computer. + +## 2.3 Relation to other Recommendations + +Videotex interworking gateway characteristics are based upon concepts of DTAM defined in the T.400-Series Recommendations. + +Videotex interworking conforms to the videotex service defined in Recommendation F.300 and it is specified by the following profiles: + +- a document application profile specified in Recommendation T.504; +- a communication application profile specified in Recommendation T.523; +- an operational application profile specified in Recommendation T.541. + +General concepts of the international videotex interworking and the data syntaxes relevant for the videotex interworking are defined in Recommendation T.101. + +# 3 References + +- Recommendation F.300 *Videotex service*. +- Recommendation X.200 (1988) *Reference model of open systems interconnection for CCITT applications*. +- Recommendation X.213 (1992) *Information technology – Network service definition for open systems interconnection*. +- Recommendation X.214 (1988) *Transport service definition for open systems interconnection for CCITT applications*. + +- Recommendation X.224 (1988) *Transport protocol specification for open systems interconnection for CCITT applications.* +- Recommendation X.215 (1988) *Session service definition for open systems interconnection for CCITT applications.* +- Recommendation X.225 (1988) *Session protocol specification for open systems interconnection for CCITT applications.* +- Recommendation X.216 (1988) *Presentation service definition for open systems interconnection for CCITT applications.* +- Recommendation X.226 (1988) *Presentation protocol specification for open systems interconnection for CCITT applications.* +- Recommendation X.217 (1992) *Service definition for the Association Control Service Element.* +- Recommendation X.227 (1992) *Connection-oriented protocol specification for the Association Control Service Element.* +- Recommendation T.101 *International interworking for videotex services.* +- Recommendation T.400 (1988) *Introduction to document architecture, transfer and manipulation.* +- Recommendation T.411 (1988) *Open document architecture (ODA) and interchange format – Introduction and general principles.* +- Recommendation T.412 (1988) *Open document architecture (ODA) and interchange format – Document structures.* +- Recommendation T.414 (1988) *Open document architecture (ODA) and interchange format – Document profile.* +- Recommendation T.415 (1988) *Open document architecture (ODA) and interchange format – Open document interchange format (ODIF).* +- Recommendation T.431 (1988) *Document transfer and manipulation (DTAM) – Services and protocols – Introduction and general principles.* +- Recommendation T.432 (1988) *Document transfer and manipulation (DTAM) – Services and protocols – Service definition.* +- Recommendation T.433 (1988) *Document transfer and manipulation (DTAM) – Services and protocols – Protocol specification.* +- Recommendation T.441 (1988) *Document transfer and manipulation (DTAM) – Operational structure.* +- Recommendation T.504 *Document application profile for videotex interworking.* +- Recommendation T.523 *Communication application profile DM-1 for videotex interworking.* +- Recommendation T.541 *Operational application profile for videotex interworking.* + +# 4 Definitions + +The following definitions apply to all other parts of the Recommendation. + +This Recommendation makes use of the following terms as they are defined in Recommendation F.300: + +- videotex access point; +- videotex frame; +- videotex gateway; +- videotex host; +- videotex service; +- videotex service center; +- videotex terminal; +- videotex user. + +This Recommendation makes use of the following terms as they are defined in Recommendation T.400: + +- attribute; +- content portion; +- page; +- block; +- specific layout structure; +- subordinate. + +# 5 Abbreviations + +For the purpose of this Recommendation, the following abbreviations are used: + +| | | +|------|--------------------------------------------| +| ACSE | Association control service element | +| CASE | Common application service elements | +| DDA | Defined display area | +| DTAM | Document transfer, access and manipulation | +| OSI | Open systems interconnection | +| SASE | Specific application service element | +| SE | Structure element | +| VIA | Videotex interworking architecture | + +# 6 Model of the communication between local and external host + +## 6.1 International videotex interworking between gateways + +Videotex interworking may take place between videotex services in different countries, independently from the national configuration being used. An abstract configuration model has been established in Recommendation F.300 to represent an international videotex interworking configuration using gateways. In this abstract model, each cooperating country is represented by a videotex gateway. The DTAM protocol is intended to be used between the two gateways. Consequently a typical communication may be described as shown in Figure 1. + +![Diagram illustrating the communication model between Country A and Country B. Country A includes a Terminal connected to a National videotex service, which is connected to a Gateway (Local host). Country B includes a Videotex host connected to a National videotex service, which is connected to a Gateway (External host). The two Gateways are connected via the DTAM protocol. Reference: T0818600-94/d01.](9791722d75115ddcc599b07d7bc35d73_img.jpg) + +The diagram illustrates the communication model between Country A and Country B. In Country A, a 'Terminal' (represented by a computer monitor and keyboard) is connected to a 'National videotex service' (represented by a vertical rectangle with two circular icons at the top). This service is connected to a 'Gateway' (represented by a vertical rectangle with a grid icon and a keyboard icon), which is also labeled as the 'Local host'. In Country B, a 'Videotex host' (represented by a vertical rectangle with a grid icon and a keyboard icon) is connected to a 'National videotex service' (represented by a vertical rectangle with two circular icons at the top). This service is connected to a 'Gateway' (represented by a vertical rectangle with a grid icon and a keyboard icon), which is also labeled as the 'External host'. A double-headed arrow labeled 'DTAM protocol' connects the two Gateways. The reference 'T0818600-94/d01' is located at the bottom right of the diagram. + +Diagram illustrating the communication model between Country A and Country B. Country A includes a Terminal connected to a National videotex service, which is connected to a Gateway (Local host). Country B includes a Videotex host connected to a National videotex service, which is connected to a Gateway (External host). The two Gateways are connected via the DTAM protocol. Reference: T0818600-94/d01. + +FIGURE 1/T.564 + +The abstract model is not intended to be implemented as such. It is the responsibility of Administrations to decide how a gateway may be implemented. + +Throughout this Recommendation, and for a given terminal to videotex host communication, the gateway which supports the videotex terminal through its own national videotex service is called local host. On the other hand, the gateway which supports the videotex host through its own national videotex service is called external host. + +## 6.2 Position of videotex interworking relative to OSI + +Videotex interworking between gateways handles a specific architecture called Videotex Interworking Architecture (VIA), conforming to DTAM document structures (see the T.410-Series Recommendations) and DTAM operational structure (see the T.440-Series Recommendations), and makes use of services and protocol provided by DTAM (see the T.430-Series Recommendations). + +Videotex interworking gateway characteristics are specifying the general concepts of handling the VIA. The application profiles are specifying the use of DTAM document structures, DTAM operational structures, and DTAM service and protocol. + +Figure 2 depicts this situation: + +![Diagram illustrating the position of videotex interworking relative to the OSI model. The diagram shows three layers: DTAM service, Application layer, and Presentation layer. The DTAM service layer contains a box labeled 'DTAM' with a double-headed arrow labeled 'DTAM protocol' to its right. The Application layer contains a box labeled 'ACSE' with a double-headed arrow labeled 'Presentation protocol' to its right. The Presentation layer contains a box labeled 'Presentation layer' with a double-headed arrow labeled 'Presentation protocol' to its right. A dashed oval labeled 'VIA' encloses the 'Document application profile' and 'Operational application profile' boxes. A larger dashed oval labeled 'Videotex interworking' encloses the 'VIA' oval and the 'Communication application profile' box. A horizontal dashed line separates the Application layer from the Presentation layer.](5860ad6bd2a2dd8d1ab12864b8f90f37_img.jpg) + +T0818610-94/d02 + +Diagram illustrating the position of videotex interworking relative to the OSI model. The diagram shows three layers: DTAM service, Application layer, and Presentation layer. The DTAM service layer contains a box labeled 'DTAM' with a double-headed arrow labeled 'DTAM protocol' to its right. The Application layer contains a box labeled 'ACSE' with a double-headed arrow labeled 'Presentation protocol' to its right. The Presentation layer contains a box labeled 'Presentation layer' with a double-headed arrow labeled 'Presentation protocol' to its right. A dashed oval labeled 'VIA' encloses the 'Document application profile' and 'Operational application profile' boxes. A larger dashed oval labeled 'Videotex interworking' encloses the 'VIA' oval and the 'Communication application profile' box. A horizontal dashed line separates the Application layer from the Presentation layer. + +FIGURE 2/T.564 + +## 6.3 Organization of the videotex interworking + +The videotex interworking application process consists of two parts which are in charge of: + +- managing the communication with the peer entity; +- supporting the local application process. + +The Videotex Interworking Architecture (VIA), the DTAM service and the DTAM protocol correspond to the communicating part of the application process and represent those aspects of the application process which are pertinent to OSI. + +The VIA is a virtual data structure with a set of possible actions that can be performed on it. This structure is used to represent the current state of the communication between the two applications processes. + +Any operation on VIA must be reported to the peer entity and to the Videotex service user. These operations are reported to the peer entity by using the DTAM service which is provided by the DTAM protocol. + +- a) In the first dialogue step, the external host defines a data entry program which describes all the actions the local host must follow when the user enters data. This data entry program contains the description of the form, i.e. the description of the different areas of the screen where entry will be performed. It also contains the reactions to user's inputs the local host has to follow. These reactions, called rules, contain e.g. the list of allowed character, the type of echo to be performed, the list of possible commands, etc. Moreover, a guidance message, called prompts, may be associated with each Field. These messages are displayed each time the cursor reaches or leaves the corresponding Field in order to give to the user some information about the filling of the form; +- b) When the local host then receives the run (in the case of duplex mode) the local host immediately sends it back to the external host. It then executes the defined data entry program till encountering an event which provokes the termination of the entry. This events must be one of the termination reasons defined by the external host and correspond either to a valid user command or to the running out of a time-out or to the entire filling of a field. The termination reason is reported back to the external host as the second dialogue step. According to the regulations of the Videotex service at the local host side, the report may or may not contain the data entered by the Videotex user. + +NOTE – Figure 3 is for information on the videotex interworking organization only. + +![Diagram illustrating the interworking organization between two Videotex services (Videotex service 1 and Videotex service 2) via the DTAM protocol. Each service consists of a Local application process (containing VIA) and a DTAM service interface. The DTAM service interfaces of both services are connected via the DTAM protocol.](b3baf3a29b67c7425d2562ddbc52f0cc_img.jpg) + +``` + +graph LR + subgraph "Videotex service 1" + LAP1[Local application process] + LAP1 --- VIA1([VIA]) + LAP1 --- DTAM1[DTAM] + end + subgraph "Videotex service 2" + LAP2[Local application process] + LAP2 --- VIA2([VIA]) + LAP2 --- DTAM2[DTAM] + end + DTAM1 <--> |DTAM protocol| DTAM2 + +``` + +T0818620-94/d03 + +Diagram illustrating the interworking organization between two Videotex services (Videotex service 1 and Videotex service 2) via the DTAM protocol. Each service consists of a Local application process (containing VIA) and a DTAM service interface. The DTAM service interfaces of both services are connected via the DTAM protocol. + +FIGURE 3/T.564 + +# 7 Relation between videotex and DTAM service (see Figure 4) + +This clause does not form an integral part of this Recommendation. + +The local application process is in charge of the local mapping between the communicating OSI environment and the videotex service as defined by a given Administration. On the local host side, the local application process is in charge of converting the local host to external host dialogue into a videotex user dialogue. On the external host side, the local application process is in charge of converting the external host to local host dialogue into a national videotex host access dialogue. + +The two local application processes are able to communicate on an international basis by updating both their own and the peer entity VIA, which represents the common view of the communication as seen by both partners. To indicate that a VIA update is needed, the local process may express all the VIA modifications as DTAM service elements through the DTAM service interface. Any modification of the VIA must be reported to both the local and the remote users. + +When receiving a DTAM service primitive, the VIA is updated and the receiving local application process takes the updating into account. + +![Diagram illustrating the interaction between a Local application process, VIA, Videotex service, and DTAM service.](a5ee5c23b6dc52ec1d724b76d5a5f58f_img.jpg) + +The diagram shows a central box labeled 'Local application process'. Above it is an oval labeled 'VIA'. To the left is a vertical dashed line labeled 'Videotex service' with a double-headed arrow connecting it to the 'Local application process' box. To the right is a vertical dashed line labeled 'DTAM service' with a double-headed arrow connecting it to the 'Local application process' box. A single-headed arrow points from the 'Local application process' box up to the 'VIA' oval, and another single-headed arrow points from the 'VIA' oval down to the 'Local application process' box. Below the 'DTAM service' label is the text 'T0818630-94/d04'. + +Diagram illustrating the interaction between a Local application process, VIA, Videotex service, and DTAM service. + +FIGURE 4/T.564 + +For a given definition of a videotex service, several local application processes may exist with different levels of complexity. For example, a given local application process may not take into account the existing VIA, or for each new frame to be displayed, delete the existing VIA and create a brand new one. A more clever local application process may, on its own, take care of the previous VIA and express through the DTAM service interface the sole modification of the VIA. + +It is up to the Administrations concerned to define all the details of the local application process to communicate through the DTAM service, which supports the local application process. + +# 8 Use of lower layer services + +The use of lower layer services is specified in Recommendation T.101. + +# 9 General structure of the VIA + +## 9.1 General data structure + +The following list is a basic set of requirements for the properties of a general data structure handled by the videotex interworking gateway. + +Videotex interworking is an application profile on top of DTAM and the videotex interworking architecture (VIA) is in line with the general structuring principles defined in Recommendation T.400. + +The VIA consists of a document profile, an operational profile and five data structures: + +- a specific layout structure: the display structure; +- four operational structures which are used to carry: + - 1) the data entry structure; + - 2) the application control memory structure; + - 3) the administrative structure; + - 4) the special terminal facilities structure. + +NOTE – Only one operation profile is used for the four concerned operational structures. + +The data structure is composed of structure elements (SE) which can be manipulated independently as long as the protocol and other dependency rules are observed. + +The state of the VIA is determined by the states of all the elements of the VIA and the relationship between them. + +The station of the VIA expresses the current state of communication between the two partners. + +Manipulations of the structure elements of the VIA are specified as VIA operations and mapped to DTAM service elements. + +## **9.2 Attributes** + +The categories of SE attributes are: + +- a) identification attributes which specify the type of the SE and identify individual SE; +- b) application defined attributes which are only meaningful for the videotex interworking architecture; +- c) specific attributes which depend on the SE type; +- d) default-value attributes which specify values to be used in identified SE types at lower level in the hierarchy; +- e) reference attributes which specify the relation between SEs. + +### **9.2.1 Identification attributes** + +The identification attributes are the object type and object identifier attributes defined in Recommendation T.412 and in Recommendation T.441 (see also Annex A/T.541). + +### **9.2.2 Application defined attributes** + +Application defined attributes are attributes specified within this Recommendation for the structure elements of the VIA, with nonequivalent attributes within the T.400-Series Recommendations. They are either mapped to the attribute “application comments” specified in Recommendation T.412 (for attributes pertaining to the display structure) or mapped on the “application defined attribute list” specified in Recommendation T.441 (for attributes pertaining to one of the four other VIA data structures). The mapping is specified in Recommendation T.504 or in Recommendation T.541, respectively. + +### **9.2.3 Specific attributes** + +These attributes depend on the SE-type. Examples of specific attributes are attributes specifying the position or the dimension of the text. These attributes are defined in Recommendation T.412. + +### **9.2.4 Default value attributes** + +Since no generic structure, neither object class specification, nor styles are used for the VIA, the values of defaultable attributes may only be derived from either standard default values specified for the VIA (in a relevant ITU-T Recommendation) or from a default value list. A default value list may only be used at the highest level of hierarchy in a given data structure. + +Therefore, to determine the value of an attribute classified as defaultable the priority order is: + +- 1) attribute values specified explicitly in the attribute list of the SE itself; +- 2) attribute values specified in the “default value list” attributes of the SE situated at the highest level of hierarchy in the considered data structure; +- 3) the default value derived from the document profile (see Recommendation T.504) or from the operational application profile (see Recommendation T.541); +- 4) the default value defined in Recommendation T.412 or Recommendation T.441 (see also Annex A/T.541). + +### **9.2.5 Reference attributes** + +Reference attributes specify the relationships between the SEs aside from the tree-structure. Reference attributes are specified in Recommendation T.441 (see also Annex A/T.541). The use of the reference attribute is specified in this Recommendation. + +## 9.3 General VIA operation + +The VIA data structure is partly initialized at the connection establishment time. A number of SEs are implicitly created (see Annex A). + +The VIA is then created and modified by a series of general VIA-operations on SEs. All the VIA operations provoke: + +- a modification of the local VIA; +- the exchange of DTAM primitives specifying which VIA operations are to be performed on the remote VIA. Recommendation T.523 specifies the mapping of the general VIA operations onto the relevant DTAM operations and the rules for the use of the DTAM service. + +After reception of an indication primitive from the DTAM service the VIA is updated and the VIA operations are indicated to the local videotex service user. + +The general VIA operations to be performed on the SEs are: + +- a) *CREATE* – The creation of an SE. +- b) *DELETE* – The deletion of an SE and all its subordinate SEs. +- c) *MODIFY* – The modification of attributes of an SE. + +NOTE – Use of MODIFY operation to add text to both content information attribute of text-unit and operational element content attribute is for further study. +- d) *REBUILD* – The deletion of an SE and its subordinates followed by the creation of a new SE replacing the previously deleted one. This is for further study. +- e) *CALL MEMORY* – The invocation of predefined or stored sequences of VIA operations. + +A DTAM service primitive addressing a particular SE has influence on the existence of that SE (CREATE, DELETE) or on the attributes of the SE (MODIFY). + +# 10 Videotex structure + +The videotex structure consists of a document profile, an operational profile and the following structures: + +- *The display structure (layout structure)* + +It contains information concerning the layout and information to be displayed. In the VIA the display structure is represented by the DOCUMENT-SE and the subordinate SEs of the DOCUMENT-SE. +- *Four operational structures* + - 1) *The data entry structure* + +It provides the user with a flexible means of entering data. It contains elements for describing the layout of fields, for storing data and for describing the reaction to various user inputs. It is represented in the VIA by the DATA-ENTRY-SE and its subordinate SEs. + - 2) *The application control memory structure* + +It is used to store VIA operations which can be repeatedly invoked. It is represented in the VIA by the APPLICATION-CONTROL-MEMORY-SE and its subordinate SEs. + - 3) *The administrative structure* + +It copes with informations such as accounting and identification and is represented in the VIA by the ADMINISTRATIVE-INFORMATION-SE and its subordinate SEs. + - 4) *The special terminal facilities structure* + +It is used to handle data necessary to set the terminal in a special state. This data is sent to the terminal before the actual “display data” is sent (e.g. character of dynamically redefinable character set). It is represented in the VIA by the SPECIAL-TERMINAL-FACILITIES-SE and its subordinate SEs. + +## 10.1 Display structure + +### 10.1.1 Overview of the display structure + +The display structure is concerned with the data to be displayed on the videotex terminal. The following paragraphs only describe the elements specific to the display structure. The text of a document to be displayed on a screen can be separated into various parts in order to: + +- distinguish between presentation units (such as areas on the screen) or logical units and the rest of the screen; +- use of different types of coding; +- allow some parts of the screen to be protected or scrolled; +- allow some parts of the screen to be updated independently from the rest of the screen and have a longer or shorter life than other parts. + +This separation introduces a sub-image concept which allows different logical and independent areas to be recognized within the screen. These sub-images can be: + +- updated independently; +- coded independently; +- organized in order to take care of application requirements. + +The sub-image concept also allows: + +- to clearly separate data entry and display areas; +- to compose a screen via a library of sub-images; +- to store sub-images independently of the final position on the screen. + +The display structure consists of: + +- one DOCUMENT-SE; +- one PAGE-SE describing the page structure which is used to display videotex frames; +- one or more BLOCK-SEs subordinate to the page; +- at most one content portion subordinate to each block. + +Figure 5 describes the hierarchy of the display structure elements. + +![A hierarchical diagram showing the structure of display elements. It consists of four vertically stacked shapes connected by lines. The top shape is an oval labeled 'Document layout root'. A line connects it to a second oval labeled 'Page'. Another line connects 'Page' to a third oval labeled 'Block'. A final line connects 'Block' to a rectangle at the bottom labeled 'Content portion'.](5a9282ac54ca7bc50f1d2ab6cfb376ba_img.jpg) + +``` +graph TD; A([Document layout root]) --- B([Page]); B --- C([Block]); C --- D[Content portion]; +``` + +T0818640-94/d05 + +A hierarchical diagram showing the structure of display elements. It consists of four vertically stacked shapes connected by lines. The top shape is an oval labeled 'Document layout root'. A line connects it to a second oval labeled 'Page'. Another line connects 'Page' to a third oval labeled 'Block'. A final line connects 'Block' to a rectangle at the bottom labeled 'Content portion'. + +FIGURE 5/T.564 + +In the context of videotex interworking between gateways, a page is a rectangular area that corresponds to the interchanged defined display area (DDA). A page is always a composite object. + +Blocks are immediately subordinate to a page. Blocks are rectangular areas. Block-size is restricted to be equal to the page. The use of block-size not equal to page is for further study. + +All constituents of the display structure conform to the definitions of the document structures as specified in the T.400-Series Recommendations. + +The document application profile defined in Recommendation T.504 specifies details on the document profile and the display structure for the videotex interworking between gateways. + +### **10.1.2 Application defined attributes** + +This subclause identifies specific attributes used by the videotex interworking gateway which do not influence the layout process as defined in the T.400-Series Recommendations. These attributes have no direct equivalent in Recommendation T.412 and are mapped to the attribute “application comments”. + +#### **10.1.2.1 Write-access attribute** + +This attribute is associated with each SE. The specification of this attribute is valid for all structures of the VIA. Its value is used to control the independent manipulation of the SE by any of two communicating hosts (local and external), specifying which host may, at any time: + +- modify the attributes of the SE; +- delete or create subordinates SEs. + +This attribute also specifies the way how the write access may be transferred between the two hosts. + +This attribute is introduced for further structuring and controlling of the dialogue. This is for further study. + +#### **10.1.2.2 Display-indication** + +This attribute identifies if the block is to be displayed or not. It may take the value “mandatory” or “optional”. + +If the value “mandatory” is selected, then the block is to be displayed, even if the user types ahead. + +If the value “optional” is selected, then the local host may decide not to display the block when the user types ahead. + +All “mandatory” blocks within the page must be displayed. + +## **10.2 Data entry structure** + +### **10.2.1 Overview of the data entry structure** + +The data entry structure is used to represent the data entry function. This function is sometimes also referred to as data collection function. It allows for a controlled entrance of user supplied information in a truly distributed environment between the local and external hosts. In order to prevent exchange of data through the network for each elementary action of the user, several dialogue steps have to be considered between the local and external host: + +- a) In the first dialogue step, the external host defines a data entry program which describes all the actions the local host must follow when the user enters data. This data entry program contains the description of the form, i.e. the description of the different areas of the screen where entry will be performed. It also contains the reactions to user’s inputs the local host has to follow. These reactions, called rules, contain e.g. the list of allowed character, the type of echo to be performed, the list of possible commands, etc. Moreover, a guidance message, called prompts, may be associated with each field. These messages are displayed each time the cursor reaches or leaves the corresponding field in order to give to the user some information about the filling of the form; + +- b) When the local host then receives the run (in the case of duplex mode) the local host immediately sends it back to the external host. It executes the defined data entry program till encountering an event which provokes the termination of the entry. This event must be one of the termination reasons defined by the external host and correspond either to a valid user command or to the running out of a time out or to the entire filling of a field. The termination reason is reported back to the external host as the second dialogue step. According to the regulations of the videotex service at the local host side, the report may or may not contain the data entered by the videotex user. + +### 10.2.2 Data entry structure description (see Figure 6) + +The data entry structure consists of: + +- a) one DATA-ENTRY-SE; +- b) subordinate to the DATA-ENTRY-SE: + - zero, one or more FIELD-SEs; + - one DATA-ENTRY-PROGRAM-SE; + - one or more RULES-SEs; + - zero, one or more PROMPT-SEs; + - one RESULT-SE; +- c) a single content portion subordinate to a FIELD-SE; +- d) a single content portion subordinate to RESULT-SE; +- e) one or more DATA-ENTRY-SUBPROGRAM-SEs subordinate to the DATA-ENTRY-PROGRAM-SE; +- f) a single content portion subordinate to a PROMPT-SE. + +![Figure 6/T.564: Data entry structure diagram. The diagram shows a hierarchical structure. At the top is an oval labeled 'Data-entry'. It has five direct connections to ovals below it: 'Field', 'Data-entry program', 'Rules', 'Prompt', and 'Result'. Below 'Field' is a rectangle labeled 'Content'. Below 'Data-entry program' is an oval labeled 'Data-entry subprogram'. Below 'Rules' is a rectangle labeled 'Content'. Below 'Prompt' is a rectangle labeled 'Content'. Below 'Result' is a rectangle labeled 'Content'. Dashed arrows point from 'Data-entry subprogram' to 'Field', 'Rules', and 'Prompt'.](75f0cb39f1cd165dfe4a6aa6c4d9388d_img.jpg) + +``` + +graph TD + DE([Data-entry]) --- F([Field]) + DE --- DEP([Data-entry program]) + DE --- R([Rules]) + DE --- P([Prompt]) + DE --- RES([Result]) + F --- C1[Content] + DEP --- DES([Data-entry subprogram]) + DES -.-> F + DES -.-> R + DES -.-> P + R --- C2[Content] + P --- C3[Content] + RES --- C4[Content] + +``` + +Figure 6/T.564: Data entry structure diagram. The diagram shows a hierarchical structure. At the top is an oval labeled 'Data-entry'. It has five direct connections to ovals below it: 'Field', 'Data-entry program', 'Rules', 'Prompt', and 'Result'. Below 'Field' is a rectangle labeled 'Content'. Below 'Data-entry program' is an oval labeled 'Data-entry subprogram'. Below 'Rules' is a rectangle labeled 'Content'. Below 'Prompt' is a rectangle labeled 'Content'. Below 'Result' is a rectangle labeled 'Content'. Dashed arrows point from 'Data-entry subprogram' to 'Field', 'Rules', and 'Prompt'. + +T0818650-94/d06 + +FIGURE 6/T.564 + +### 10.2.3 Modes of communication + +Two modes of communication between local and external host are defined: + +- alternate mode; +- duplex mode. + +The communication between local and external host may be based on the alternate mode, on the duplex mode, or on both modes. + +If the communication is based on the alternate mode, the local host should support data entry type 1, type 2 and type 3. + +If the communication is based on the duplex mode, the local host should support data entry type 4. + +If the communication is based on both modes, the local host should support all types of data entry. + +The mode of communication is negotiated in the DTAM association initialization phase. Details are specified in Recommendation T.523. + +**10.2.4 Types of data entry** + +The four different types of data entry program which have been identified, correspond to different types of applications and different characteristics of fields: + +- a) *Type 1 – Information retrieval* + This type makes use of a single implicit information retrieval field which is always present when data entry type 1 is selected. The position and dimensions of the field are determined by the lost host, generally corresponding to an area located in the bottom part of the screen. Consequently, non-specific FIELD-SE must be used and the reference- to-a-FIELD-SE attribute of the DATA-ENTRY-SUBPROGRAM-SE may be set to undefined or not be taken into account if defined. When the user has terminated the data entry, the information which is sent back to the external host consists of the RESULT-SE which describes all the conditions encountered when the entry is stopped (termination reason, ...). The text associated with the termination reason, if any, is sent to the external host via the content portion associated with the RESULT-SE. + +- b) *Type 2 – Data collection* + This type generally corresponds to a form type of entry and makes use of one or more fields entirely defined by the external host. Moreover, in some videotex services, a single implicit information retrieval field may also be associated with this entry type to enter a videotex command (see 10.2.12.8.1). When the user has terminated the data entry, the information which is sent back to the external host are the content portions associated with the fields and the RESULT-SE. The text associated with the termination reason, if any, is sent to the external host via the content portion associated with the RESULT-SE. + +- c) *Type 3 – Data entry “on the fly”* + This type makes use of a single implicit field which is always present when data entry type 3 is selected. The position and dimensions of this implicit field are determined by the cursor position after the display of the information sent by the external host. Consequently, no specified FIELD-SE is used and reference-to-a-FIELD-SE attribute of the DATA-ENTRY-SUBPROGRAM-SE may be set to undefined and should not be taken into account when defined. The size of the field is fixed to 128 bytes. When the user has terminated the data entry, the information which is sent back to the external host consists of the RESULT-SE. The text associated with the termination reason, if any, is sent to the external host via the content portion associated with the RESULT-SE. + +- d) *Type 4 – Duplex data entry* + This type makes use of a single implicit field which is always present when data entry type 4 is selected. The position and dimensions of this implicit field are determined by the current cursor position. Consequently, no specific FIELD-SE is used and reference-to-a-FIELD-SE attribute of the DATA-ENTRY-SUBPROGRAM-SE may be set to undefined and should not be taken into account when defined. The size of the field is fixed to 128 bytes. When the user has terminated the data entry, the information which is sent back to the external host consists of the RESULT-SE. The text associated with the termination reason, if any, is sent to the external host via the content portion associated with the RESULT-SE. + +**10.2.5 DATA-ENTRY-SE** + +This is the SE at the highest level of the data entry structure. Only one DATA-ENTRY-SE may be defined at a given time. + +12 Recommendation T.564 (03/93) + +### **10.2.6 DATA-ENTRY-PROGRAM-SE** + +This SE is subordinate to the DATA-ENTRY-SE. At a given time, one and only one DATA-ENTRY-PROGRAM-SE may be subordinate to the DATA-ENTRY-SE. A data entry program performs a data collection function on a form. A form corresponds to a screen structured into none, one or more fields where the user may enter data. + +The following attribute is mapped to the reference attribute defined in Recommendation T.441 (see also Annex A/T.541). + +#### **10.2.6.1 First-subprogram** + +This attribute is set by the external host to indicate to the local host the reference to the first data entry subprogram to be executed. However, if the local host is not able to start with the indicated first subprogram the local host may fall back to process the subprograms in the natural order of the SE-identifiers. + +The application defined attributes of the DATA-ENTRY-PROGRAM-SE are the following: + +#### **10.2.6.2 Data-entry-type** + +This attribute is specified by the external host to indicate which interpretation the local host has to perform in order to be able to support the entry. This attribute may take the value type 1, 2, 3 or 4. The value indicates which type of data entry has to be performed. + +##### **Control of the user input** + +NOTE – In the general situation of an international videotex interworking the following attributes, specified to allow local hosts to control the users' input, may not be supported by some local hosts. In these cases no checking of the relevant attributes will be performed by the local host. + +#### **10.2.6.3 Allowed-characters-for-a-keyword-access-command** + +This attribute set by the external host indicates whether the list of characters represents the allowed or forbidden characters. + +*Possible values:* + +- Yes: means allowed characters in the list; +- No: means forbidden characters in the list. + +This attribute is not taken into account if the D1 d command is disabled. + +#### **10.2.6.4 Character-list-for-keyword-access** + +This attribute set by the external host contains a list of allowed or forbidden characters for keyword access. The list is encoded according to T.51 plus "space". + +This attribute is not taken into account if the D1 d command is disabled. + +#### **10.2.6.5 Max-length-keyword-access** + +This attribute set by the external host specifies the maximum length of the input field for keyword access. + +#### **10.2.6.6 Allowed-character-for-a-direct-access-command** + +This attribute indicates whether alphabetic characters (a, b, ... z) may be used inside a direct access command. This attribute is defined by the external host but not taken into account if the D1 b command is disabled. + +*Possible values:* + +- Yes: means alphabetic characters are allowed; +- No: means alphabetic characters are not allowed. + +#### **10.2.6.7 Max-length-direct-access** + +This attribute set by the external host specifies the maximum length of the direct access input. + +### **10.2.7 RESULT-SE** + +The RESULT-SE is subordinate to the DATA-ENTRY-SE. At a given time only one RESULT-SE may be subordinate to the DATA-ENTRY-SE. + +The following attribute is mapped to the reference attribute defined in Recommendation T.441 (see also Annex A/T.541). + +#### **10.2.7.1 Last subprogram** + +This attribute set by the local host reflects the reference to the data entry subprogram currently being executed when a termination reason was detected. Some local hosts may not be able to update this attribute when the user aborts the filling of the form. Consequently, this attribute may be left undefined when the termination reason is D17. + +The application defined attribute of the RESULT-SE is the following: + +#### **10.2.7.2 Termination reason** + +This attribute set by the local host indicates the reason which provoked the termination of the data entry. This reason may be either a valid command, the entire filling of the field or the expiration of a time-out. + +### **10.2.8 Result content portion** + +This content portion set by the local host and reported in some cases to the external host if the termination reason attribute of the RESULT-SE corresponds to a command with parameter: D1. + +The result content portion makes use of the attribute operational element content type (see Recommendation T.441 and Annex A/T.541), as follows: + +#### **10.2.8.1 Type of coding** + +This attribute is set by the local host and specifies the coding used to represent the content and may take one of the following values: + +- T.50 (IRV); +- T.51 “plus space”. + +The result content portion makes use of the attribute operational element content (see Recommendation T.441 or Annex A/T.541), as follows: + +#### **10.2.8.2 Content information** + +This attribute is set by the local host to report the text associated with the termination-reason attribute of the RESULT-SE, if any. + +### **10.2.9 FIELD-SE** + +A field is used to define a sub-image where user inputs are to be echoed. It is used by the local host for reporting to the external host user inputs. It may also be used by the external host to describe a sub-image or to set initial data into an entry area. A FIELD-SE is subordinate to a DATA-ENTRY-SE. At a given time, several FIELD-SEs may be subordinate to a DATA-ENTRY-SE. + +The application defined attributes of the FIELD-SE are the following: + +#### **10.2.9.1 Field layout** + +This attribute specifies the layout characteristics of the field. A field is described as a sequence of rectangular areas called hereafter field-blocks. Each field-block is described by its position (X, Y) and its dimensions (DX, DY). + +##### Use of system fields + +##### NOTES + +1 The system field facility is an optional function provided by a videotex service. A system field is a data collection field in which predetermined type of data is filled in by the videotex service or by the user. + +2 When using system fields in an international connection it has to be taken into account that a general user identification mechanism based on the ongoing work on ACSE and the use of association (D-INITIATE service) is for further study, and that the harmonization of the concerned type of data with other telematic services is still under study. + +3 It is up to the Administrations to decide to set up or not the system field facility. + +4 The implementation and use of the above system fields in international connections may be subject to legal restrictions (e.g. consumer privacy) that may be in effect nationally or internationally. + +5 Services which do not support the system field facility will ignore all the associated protocol items and consider all the system fields as normal data collection fields. + +6 The international availability of this data or parts of it may be subject to legal restrictions or restrictions imposed by users or Administrations. + +#### 10.2.9.2 Field-type + +This attribute is set by the external host to indicate whether or not the field is a system field. A system field is a field that should be filled in by the local host system itself and not by the user. If this attribute has the value "0" then the field is to be completed by the user – i.e. a normal data collection field. A non-zero value indicates that (if possible) the local host should complete the field with system data as follows: + +- 1 Country code + - 1a National telephone number +- 2 Subscriber No. + - 2a Co-user-suffix + - 2b User No. +- 3 Subscriber title +- 4 Subscriber name +- 5 Additional name +- 6 Street +- 7 Town +- 8 Postcode +- 9 Date +- 10 Time +- 11 Date and time + +NOTE – Local hosts which do not support system fields regard all system fields as marked with a zero value. + +If on the other hand an external host does not support system fields, local hosts requiring this attribute are defaulting the value of the field-type attribute to "0". + +#### 10.2.9.3 Protected + +This attribute is only meaningful for system fields. For those local hosts which are not able to process system fields, this attribute is not taken into account. + +This attribute indicates whether or not the system field may be modified by the user. The value "yes" indicates that the local host must prevent the user from modifying the contents of the field. + +#### 10.2.9.4 Data-source + +This attribute is only meaningful when the field-type attribute is used, the value is not equal to “0” and the protected attribute has the value “not protected”. + +This attribute can have the values “local host” and “user” to indicate whether the data returned to the external host was supplied by the local host or by the user. + +#### 10.2.9.5 Field-text-marking + +This attribute specifies the visual appearance on the terminal of the contents of the field. The following values have been identified: + +- a) “explicit” means that a value for one or more of the following attributes: + - foreground colour; + - background colour; + - underlining; + - flashing; + - reverse video,may explicitly be defined by the external host; +- b) “keep current attributes” means that the value of the foreground colour, background colour, underlining, flashing and reverse video are then those naturally defined by positioning the cursor in the field. + +In both cases, this attribute is applied by the local host as far as possible but the local host may ignore it. + +### 10.2.10 Field content portion + +This content portion is used when data entry type 2 is selected. The field content portion makes use of the attribute operational element content type (see Recommendation T.441, or Annex A/T.541) as follows: + +#### 10.2.10.1 Type of coding + +This attribute may be set either by the external or local host and specifies the coding used to represent the content and may take one of the following values: + +- T.50 (IRV); +- T.51 “plus space”. + +The field content portion makes use of the attribute operational element content (see Recommendation T.441, or Annex A/T.541) as follows: + +#### 10.2.10.2 Content information + +This attribute may be set either by the external or by the local host and represents the contents of the field. The correspondence between the content information and the different field-blocks of the field is given by the defined order of these field-blocks in the layout attribute of the FIELD-SE, regardless of the relative position of these parts with respect to the screen. + +When set by the external host, this attribute represents the initial content of the field. + +When set by the local host, this attribute represents the data entered by the user. + +### 10.2.11 DATA-ENTRY-SUBPROGRAM-SE + +The DATA-ENTRY-SUBPROGRAM-SE is subordinate to the DATA-ENTRY-PROGRAM-SE. Each data entry subprogram applies to one and only one field. There are as many subprograms as fields in the form; consequently, depending on the complexity of the form, one or more data entry subprograms may be defined at the same time. + +The following attributes are mapped to the reference attribute defined in Recommendation T.441 (or in Annex A/T.541). + +#### **10.2.11.1 Reference-to-a-RULES-SE** + +This attribute points to a RULES-SE. This attribute cannot take the value “undefined” and must be defined either explicitly or via the default value list mechanism. + +##### **Use of prompts** + +NOTE – Prompts are guidance messages that may be associated with each data entry subprogram and are described by the corresponding PROMPT-SEs. Zero, one or two prompts may be associated with each data entry subprogram. If no prompt is associated, both of the relevant reference attributes will not be defined and no prompt message is to be displayed. It is up to the external host to use only a prompt-in or a prompt-in and a prompt-out. On the other hand some local hosts may not support the use of a prompt-out and consequently will ignore the relevant attribute and automatically erase the prompt-in. + +#### **10.2.11.2 Reference-to-a-PROMPT-IN-SE** + +This attribute set by the external host points to a PROMPT-SE which is displayed by the local host when this data entry subprogram starts. This attribute may be set to undefined if no prompt-in message is to be displayed. + +#### **10.2.11.3 Reference-to-a-PROMPT-OUT-SE** + +This attribute set by the external host points to a PROMPT-SE which is displayed by the local host when this data entry subprogram is stopped. This attribute may be set to undefined if no prompt out message is to be displayed. + +Using a prompt-in and a prompt-out instead of one prompt has not been finally discussed. This is for further study. + +#### **10.2.11.4 Reference-to-a-FIELD-SE** + +The value of this attribute depends on the type of the data entry subprogram concerned (information retrieval, data collection or data entry “on-the-fly” or duplex data entry). When defined, it indicates the area in which input characters have to be echoed. + +The application defined attributes of the data entry subprogram are the following: + +#### **10.2.11.5 Echo** + +This attribute set by the external host specifies the type of echo to be performed by the local host. It may take one of the three values: + +- *Normal echo* – The input character is echoed. +- *Fixed echo* – A fixed character is displayed. +- *Null* – No echo is performed. + +#### **10.2.11.6 Echoed character** + +This attribute is set by the external host and taken into account only if the echo attribute is set to “fixed echo”. This attribute specifies a character from the list described in Recommendation T.51 “plus space”. + +#### **10.2.11.7 Echoed parameter** + +This attribute set by the external host specifies the videotex attributes which should apply to the echo, if any. This attribute may specify values for one or several of the following attributes: foreground colour, background colour, underline, echo size (normal size, double high, double width, double size), flashing and reverse video. + +This attribute is applied by the local host as far as possible, but the local host may ignore it. + +### **10.2.12 RULES-SE** + +This SE is subordinate to the DATA-ENTRY-SE. It describes the rules applicable to the entry in a field: list of allowed characters, list of authorized retrieval functions, etc. + +The application defined attributes of the RULES-SE are the following: + +#### 10.2.12.1 Time-out + +This attribute set by the external host defines the maximum time allowed to the user to enter data. The length of time is measured in seconds. Value 0 indicates that there is no time limit imposed in seconds. Value 1 is reserved for data entry type 1 and will be interpreted by some external hosts as a request for chained frames. A value 1 should be interpreted by the local host as a normal time-out. some local hosts may overwrite with their own value a time-out whose value is greater than 1. + +Expiration of time-out provokes termination of the data entry. + +#### 10.2.12.2 Entry-invoke-character + +This attribute set by the external host defines how the empty positions of the field are filled after displaying the initial contents. The following value is identified: + +- a fixed character from T.51 plus the character “space”. + +The visual appearance of the entry-invoke-character is controlled by the field-text-marking attribute. These characters are not entered in the field content portion and not reported to the external host. + +#### 10.2.12.3 Local editing + +This attribute set by the external host indicates that powerful editing capabilities should be performed in the associated field. Such a local editing capability defined by the local host, would allow to insert/delete character/word/line, powerful cursor movement, etc. This local editing facility is intended to be used by applications dealing with message handling. + +##### Control of the user input + +NOTE – In the general situation of an international videotex interworking the following attributes (from subclauses 10.2.12.4 to 10.2.12.7), specified to allow local hosts to control the users input, may not be supported by some local hosts. In those cases no checking of the relevant attributes will be performed by the local host. + +#### 10.2.12.4 Length of valid choices + +This attribute may take the value 1 or 2 depending on the size of the choice (one or two digits). This attribute is used only in data entry type 1 and not taken into account if the D1 c command is disabled. + +#### 10.2.12.5 List-of-enabled-choices + +This attribute is set by the external host and specifies the list of enabled choices. This attribute is not taken into account by the local host if the D1 c command is disabled. This attribute is used only in data entry type 1. + +#### 10.2.12.6 Allowed-characters (for data collections) + +This attribute set by the external host indicates if the list of characters represents the allowed or forbidden characters. + +*Possible values:* + +- “allowed”: means allowed characters in the list; +- “not allowed”: means forbidden characters in the list; +- “alphabetic”: only alphabetic characters may be entered; +- “alphanumeric”: only alphanumeric characters may be entered; +- “numeric”: only numeric characters may be entered. + +When this attribute does not have the value “allowed” or “not allowed”, the character-list attribute must not be used or will be ignored. + +This attribute is only used in data-entry-type 2. + +#### 10.2.12.7 Character-list (for data collection) + +List of characters according to the specified set in the type of coding attribute of the FIELD-SE. This attribute is set by the external host. It specifies the list of characters which may or may not be entered as user inputs in the field associated with the DATA-ENTRY-SUBPROGRAM-SE from which the RULES-SE is referred. The list of characters is encoded according to T.51 plus “space”. + +This attribute is only used in data-entry-type 2. + +#### 10.2.12.8 List of valid commands + +This attribute set by the external host specifies the list of commands which are enabled and then may be used as values for the termination reason attribute of the RESULT-SE. Other commands are disabled and cannot be used as value for the termination-reason attribute. However, enabling of commands does not imply that the local host is forced to support all the enabled commands. It is up to the local host to do its best to properly image some commands. Some local hosts may transform some commands into a disconnect. + +##### *Abbreviations:* + +| | | +|----------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| E | Enabled | +| D | Disabled | +| CP | Indicates if a result content portion may be associated with the command | +| Local | Functions handled locally between the user and the local host; such functions are not exchanged on the international link between gateways. Some functions of this type may provoke a disconnect between the local and the external host. | +| Not used | Not used for a given type of data entry. | + +NOTE 1 – Further development of videotex interworking may identify a requirement to use also the commands V1, V4, V7 on the international link. This is for further study. + +The following list defines the valid commands taken from the list of functions defined by Recommendation F.300. + +##### a) *Type 1 – Information retrieval* + +| <i>Termination reason</i> | <i>Command</i> | <i>Local</i> | <i>CP</i> | <i>E/D</i> | +|----------------------------------------------------------------------------------------------------------------|----------------|----------------|-----------|------------| +| – Select an application on a videotex service | V1 | Yes | | | +| – Leave the application and return to the first effective choice of the national videotex service (see Note 2) | V2 | No | No | E/D | +| – Return to the first effective choice of the foreign videotex service | V3 | No | No | E | +| – Leave the application and return to the point from which this application was selected | V4 | Yes | | | +| – Provide billing information | V5 | Yes | | | +| – Leave the videotex service (mandatory) (see Note 3) | V6 | Yes | | | +| – Request service/application Id | V7 | Yes | | | +| – Declare and validate an input (see Note 4) | D1 | | | | +| a) free text input | a) | No | Yes | E/D | +| b) direct selection of a frame | b) | No | Yes | E/D | +| c) progress through a choice from one frame to another by the use of one or two digits | c) | No | Yes | E/D | +| d) select a frame through the use of a keyword | d) | No | Yes | E/D | +| – Correcting an input | D2 | Yes | | | +| – Clearing an input | D3 | Yes | | | +| – Move one step forward in the application | D4 | No | No | E/D | +| – Move to the next input field | D5 | -- Not used -- | | | +| – Retrace the previous step | D6 | No | No | E/D | +| – Move to the previous field | D7 | -- Not used -- | | | +| – Repeat the frame | D8 | Yes | | | + +| | | | | | +|-----------------------------------------------------------------------------------------------------------|-----|----------------|----|-----| +| – Repeat the updated frame | D9 | No | No | E/D | +| – Return to the first menu in the application | D10 | No | No | E/D | +| – Previous menu | D11 | No | No | E/D | +| – Ask for help or guidance without leaving the application | D12 | No | No | E/D | +| – Redisplay the initial version of the currently active form | D13 | No | No | E/D | +| – Redisplay the completed version of the currently active form | D14 | No | No | E/D | +| – Interrupt the action in progress | D15 | Yes | | | +| – Set a marker at the current point in the application for access at a later time within the same session | D16 | Yes | | | +| – Abstain from forwarding the contents of the input field | D17 | -- Not used -- | | | +| – Declare valid a “set” of inputs | D18 | -- Not used -- | | | +| – Time-out (see Note 5) | | No | No | E | +| – End of field | | -- Not used -- | | | + +NOTE 2 – If this command is not supported by the local host or if this command is disabled, then the corresponding local command is mapped to a D-TERMINATE. + +NOTE 3 – This command is directly mapped to a D-TERMINATE. + +NOTE 4 – Some local hosts may not be able to make the difference between the four D1 sub-commands and consequently may replace D1 b, D1 c and D1 d by D1 a, even if disabled. + +NOTE 5 – The time-out is disabled by setting its value to 0. + +###### Use of “good-by” frames + +NOTE 6 – The local host does not support the use of “good-by” frames: in this case the local host maps the local V2 command to a D-TERMINATE request on the international connection. + +NOTE 7 – The external host does not support the use of “good-by” frames: in this case the external host should disable the V2 command and the local host consequently maps a local V2 command to a D-TERMINATE request on the international connection. + +NOTE 8 – Both hosts are supporting the use of “good-by” frames: in this case the external host enables the V2 command. If the local host sends a V2 command to the external host, the external host may send the “good-by” frame, followed by a D-TERMINATE request. + +##### b) Type 2 – Data collection + +| <i>Termination reason</i> | <i>Command</i> | <i>Local</i> | <i>CP</i> | <i>E/D</i> | +|----------------------------------------------------------------------------------------------------------------|----------------|--------------|-----------|------------| +| – Select an application on a videotex service | V1 | Yes | | | +| – Leave the application and return to the first effective choice of the national videotex service (see Note 9) | V2 | No | No | E/D | +| – Return to the first effective choice of the foreign videotex service | V3 | No | No | E | +| – Leave the application and return to the point from which this application was selected | V4 | Yes | | | +| – Provide billing information | V5 | Yes | | | +| – Leave the videotex service (mandatory) (see Note 10) | V6 | Yes | | | +| – Request service/application Id | V7 | Yes | | | +| – Declare and validate an input (see Note 11) | D1 | | | | +| a) free text input | a) | No | Yes | E/D | +| b) direct selection of a frame | b) | No | Yes | E/D | + +| | | | | | +|-----------------------------------------------------------------------------------------------------------|-----|----------------|-----|-----| +| c) progress through a choice from one frame to another by the use of one or two digits | c) | -- Not used -- | | | +| d) select a frame through the use of a keyword | d) | No | Yes | E/D | +| – Correcting an input | D2 | Yes | | | +| – Clearing an input | D3 | Yes | | | +| – Move one step forward in the application | D4 | No | No | E/D | +| – Move to the next input field | D5 | No | No | E/D | +| – Retrace the previous step | D6 | No | No | E/D | +| – Move to the previous field | D7 | No | No | E/D | +| – Repeat the frame | D8 | Yes | | | +| – Repeat the updated frame | D9 | No | No | E/D | +| – Return to the first menu in the application | D10 | No | No | E/D | +| – Previous menu | D11 | No | No | E/D | +| – Ask for help or guidance without leaving the application | D12 | No | No | E/D | +| – Redisplay the initial version of the currently active form | D13 | No | No | E/D | +| – Redisplay the completed version of the currently active form | D14 | No | No | E/D | +| – Interrupt the action in progress | D15 | Yes | | | +| – Set a marker at the current point in the application for access at a later time within the same session | D16 | Yes | | | +| – Abstain from forwarding the contents of the input field | D17 | No | No | E/D | +| – Declare valid a “set” of inputs | D18 | No | No | E/D | +| – Time-out (see Note 12) | | No | No | E | +| – End of field | | No | No | E/D | + +NOTE 9 – If this command is not supported by the local host or if this command is disabled, then the corresponding local command is mapped to a D-TERMINATE. + +NOTE 10 – This command is directly mapped to a D-TERMINATE. + +NOTE 11 – Some local hosts may not be able to make the difference between the four D1 sub-commands and consequently may replace D1 b, D1 c and D1 d by D1 a, even if disabled. + +NOTE 12 – The time-out is disabled by setting its value to 0. + +NOTE 13 – See also Notes 6 to 8 to data entry-type 1. + +##### c) *Types 3 and 4 – Data entry on the fly/duplex data entry* + +| <i>Termination reason</i> | <i>Command</i> | <i>Local</i> | <i>CP</i> | <i>E/D</i> | +|-----------------------------------------------------------------------------------------------------------------|----------------|--------------|-----------|------------| +| – Select an application on a videotex service | V1 | Yes | | | +| – Leave the application and return to the first effective choice of the national videotex service (see Note 14) | V2 | No | No | E/D | +| – Return to the first effective choice of the foreign videotex service | V3 | No | No | E | +| – Leave the application and return to the point from which this application was selected | V4 | Yes | | | +| – Provide billing information | V5 | Yes | | | +| – Leave the videotex service (see Note 15) (mandatory) | V6 | Yes | | | +| – Request service/application Id | V7 | Yes | | | + +| | | | | | +|-----------------------------------------------------------------------------------------------------------|-----|----------------|-----|-----| +| – Declare and validate an input (see Note 16) | D1 | | | | +| a) free text input | a) | No | Yes | E/D | +| b) direct selection of a frame | b) | -- Not used -- | | | +| c) progress through a choice from one frame to another by the use of one or two digits | c) | -- Not used -- | | | +| d) select a frame through the use of a keyword | d) | -- Not used -- | | | +| – Correcting an input | D2 | Yes | | | +| – Clearing an input | D3 | Yes | | | +| – Move one step forward in the application | D4 | No | No | E/D | +| – Move to the next input field | D5 | -- Not used -- | | | +| – Retrace the previous step | D6 | No | No | E/D | +| – Move to the previous field | D7 | -- Not used -- | | | +| – Repeat the frame | D8 | Yes | | | +| – Repeat the updated frame | D9 | No | No | E/D | +| – Return to the first menu in the application | D10 | No | No | E/D | +| – Previous menu | D11 | No | No | E/D | +| – Ask for help or guidance without leaving the application | D12 | No | No | E/D | +| – Redisplay the initial version of the currently active form | D13 | No | No | E/D | +| – Redisplay the completed version of the currently active form | D14 | No | No | E/D | +| – Interrupt the action in progress | D15 | Yes | | | +| – Set a marker at the current point in the application for access at a later time within the same session | D16 | Yes | | | +| – Abstain from forwarding the contents of the input field | D17 | No | No | E/D | +| – Declare valid a “set” of inputs | D18 | -- Not used -- | | | +| – Time-out (see Note 16) | | No | No | E | +| – End of field | | No | No | E/D | + +NOTE 14 – If this command is not supported by the local host or if this command is disabled, then the corresponding local command is mapped to a D-TERMINATE. + +NOTE 15 – This command is directly mapped to a D-TERMINATE. + +NOTE 16 – Time-out is disabled by setting its value to 0. + +NOTE 17 – See also Notes 6 to 8 to data-entry type 1. + +##### 10.2.12.8.1 Specification of local characteristics + +Within the national videotex service of country A the user may enter commands which are: + +- disabled by the external host; +- specified as local in the list of valid commands; +- or not used in a specific type of data entry. + +As these commands may not be passed to the external host, the following list describes the behaviour a local host should perform when receiving such a command: + +- V1 Select an application on a videotex service +Local action +- V2 Leave the application and return to the first effective choice of the national videotex service +Enabled: send to the EH or D-TERMINATE +Disabled: D-TERMINATE +- V3 Return to the first effective choice of the foreign videotex service +Enabled: send to the EH +Disabled: local error indication +- V4 Leave the application and return to the point from which this application was selected +Local action +- V5 Provide billing information +Local action +- V6 Leave the videotex service +D-TERMINATE +- V7 Request service/application id +Local action +- D1 Declare and validate an input +Enabled: send to the EH +Disabled: local error indication +- D2 Correcting an input +Local action: delete the character, if any +- D3 Clearing an input +Local action: delete the current field content and restart the current input +- D4 Move one step forward in the application (typically Next or # on the last field) +Enabled: send to the EH +Disabled: local error indication +- D5 Move to the next input field +Enabled: send to the EH +Disabled: move to the next field if any +- D6 Retrace the previous field +Enabled: send to the EH +Disabled: local error indication +- D7 Move to the previous field +Enabled: send to the EH +Disabled: move to the previous field if any +- D8 Repeat the frame +Local action: redisplay the display structure and the content of the data entry structure (field contents and prompts) then restart the data entry at the interrupted point +- D9 Repeat the updated frame +Enabled: send to the EH +Disabled: local error indication +- D10 Return to the first menu in the application +Enabled: send to the EH +Disabled: local error indication +- D11 Previous menu +Enabled: send to the EH +Disabled: local error indication + +- D12 Ask for help or guidance without leaving the application + Enabled: send to the EH + Disabled: local error indication +- D13 Redisplay the initial version of the currently active form + Enabled: send to the EH + Disabled: local error indication. (When no user input has been transmitted to the external host, also other local actions may be taken) +- D14 Redisplay the completed version of the currently active form + Enabled: send to the EH + Disabled: local error indication +- D15 Interrupt the action in progress + Local action +- D16 Set a marker at the current point + For further study +- D17 Abstain from forwarding the content (abort data collection) + Enabled: send to the EH + Disabled: local error indication +- D18 Declare valid a set of inputs + Enabled: send to the EH + Disabled: local error indication +- End of field + Enabled: send to the EH + Disabled: move to the next field if any, otherwise local error indication +- Time-out + Enabled: send to the EH + Disabled: no action + +##### **10.2.12.8.2 Use of the information retrieval field in data collection** + +In some videotex services, some user's keying action (e.g. \* or Next) may automatically provoke, even in a data entry subprogram, the termination of the filling of the current field and a cursor movement to the information retrieval field where a retrieval command may be entered. Such a command, once completed, will be interpreted as a termination event by the local host and reported back to the external host as a termination reason. + +Moreover, in the case of a direct access or keyword command, an associated text is also to be reported to the external host, setting the termination-reason-text attribute of the DATA-ENTRY-PROGRAM-SE. + +There is not a DATA-ENTRY-SUBPROGRAM-SE present in the VIA for the information retrieval field when "data-collection-type" has been selected. This includes that the RULES-SE of the last data collection field, the user has "touched", before going to the information retrieval field, is to be used also for the information retrieval field. + +### **10.2.13 PROMPT-SE** + +The PROMPT-SE is subordinate to the DATA-ENTRY-SE. The attributes of a PROMPT-SE are those of a BLOCK-SE, except for the SE-type which is PROMPT. A prompt is a message to be displayed to the user for guidance by the filling of a field. + +The prompt referred from a DATA-ENTRY-SUBPROGRAM-SE is automatically displayed when the data entry subprogram becomes active. The prompt is cancelled by the local host when the associated data entry subprogram becomes inactive i.e. when another data entry subprogram becomes active or when the data entry program is terminated. + +The cancelled prompt text on the screen must be replaced by a new prompt text and/or by "spaces". + +The application defined attributes of a PROMPT-SE are the following (as defined for the display structure): + +#### 10.2.13.1 Position + +#### 10.2.13.2 Dimensions + +### 10.2.14 Prompt content portion + +The prompt content portion makes use of the attributes operational element identifier, operational element content type, operational element content (see Recommendation T.441, or Annex A/T.541) as the related attributes for content portions (defined in Recommendation T.412) are used for blocks. + +The application defined attributes for prompt is the following: + +#### 10.2.14.1 Coding attributes + +This attribute is used in the same way as for blocks, it is specified within Recommendation T.412. + +### 10.2.15 Application control memory structure + +The application control memory structure can be used to store any operation on the VIA, for example: + +- the display structure or parts of it (e.g. create BLOCK-SE or modify FIELD-SE) or parts of it; +- the data entry structure or parts of it; +- the administrative structure or parts of it; +- the special terminal facilities structure or parts of it. + +An element from the application control memory is invoked by a D-CALL operation and applied to the VIA, if applicable, in both hosts. + +The application control memory structure consists of: + +- the APPLICATION-CONTROL-MEMORY-SE; +- one or more RECORD-SEs subordinate to the APPLICATION-CONTROL-MEMORY-SE. + +The RECORD-SE contains a sequence of one or more of the operations: D-CREATE, D-DELETE, D-MODIFY, which do not concern SEs of the application control memory structure. + +Figure 7 describes the hierarchy of the application control memory structure constituents. + +![A hierarchical diagram showing 'Application control memory' in an oval at the top, connected by a vertical line to 'Record' in an oval below it.](db395493033edacd83e212049fd55715_img.jpg) + +``` +graph TD; A([Application control memory]) --- B([Record]) +``` + +T0818660-94/d07 + +A hierarchical diagram showing 'Application control memory' in an oval at the top, connected by a vertical line to 'Record' in an oval below it. + +FIGURE 7/T.564 + +### 10.2.16 APPLICATION-CONTROL-MEMORY-SE + +### 10.2.17 RECORD-SE + +The application defined attributes of the RECORD-SE are the following: + +#### 10.2.17.1 Record content + +This attribute consists of a list of VIA operations which do not concern the RECORD-SE or the APPLICATION-CONTROL-MEMORY-SE. + +Details will depend on the ongoing work on operational structures. + +## 10.3 Administrative structure + +NOTE – This subclause is provisional. The final version will be established taking into account the results of CCITT Study Groups I and III concerning videotex administrative and charging matters. + +### 10.3.1 Overview of the administrative structure + +This structure is used for exchanging supervisory information such as: + +- items subject to negotiation (e.g. limits); +- accounting information; +- global information related to the state of the association; +- global information related to the document transferred. + +This structure consists of the ADMINISTRATIVE-INFORMATION-SE which has three subordinates (see Figure 8): + +- LOCAL-HOST-INFORMATION-SE; +- EXTERNAL-HOST-INFORMATION-SE; +- DOCUMENT-INFORMATION-SE. + +One and only one SE of each type should exist within the administrative structure. + +![A hierarchical diagram showing 'Administrative information' at the top, connected to three subordinates: 'Local host information', 'External host information', and 'Document information'.](718be1eb075833deb7a3b80729a06264_img.jpg) + +``` +graph TD; A([Administrative information]) --- B([Local host information]); A --- C([External host information]); A --- D([Document information]); +``` + +T0818670-94/d08 + +A hierarchical diagram showing 'Administrative information' at the top, connected to three subordinates: 'Local host information', 'External host information', and 'Document information'. + +FIGURE 8/T.564 + +### **10.3.2 ADMINISTRATIVE-INFORMATION-SE** + +This SE contains information pertinent throughout the whole association. This SE makes use of the following application defined attributes: + +#### **10.3.2.1 External host Id** + +This attribute identifies the external host to be connected to. + +#### **10.3.2.2 Local host Id** + +This attribute identifies the originating host. + +#### **10.3.2.3 Bilateral management parameter** + +This attribute is reserved for information which is exchanged between the two gateways and can be based on bilateral agreement. + +### **10.3.3 LOCAL-HOST-INFORMATION-SE** + +This element is used to transfer information from the local host to the external host. + +This element makes use of the following application defined attribute: + +#### **10.3.3.1 Error report to external host** + +This attribute is used to indicate to the external host the reason why the local host could not handle the previously received reply. + +### **10.3.4 EXTERNAL-HOST-INFORMATION-SE** + +This element is used to transfer information from the external host to the local host. + +This element makes use of the following application defined attributes: + +#### **10.3.4.1 Error report to local host** + +This attribute is used to indicate to the local host the reason why the external host could not handle the previously received reply. + +#### **10.3.4.2 Asynchronous message** + +This attribute is used to transfer a warning message to the local host. + +### **10.3.5 DOCUMENT-INFORMATION-SE** + +This element contains attributes that supply additional charging information associated with the document and to be used by the local host. + +This element contains the following application defined attributes: + +#### **10.3.5.1 Application time based charging period** + +This attribute defines the length of the time base in seconds. + +#### **10.3.5.2 Application price: frame based** + +This attribute indicates the frame based price of the application in the currency of the external host. + +#### **10.3.5.3 Application price: transaction based** + +This attribute indicates the transaction based price of the application in the currency of the external host. + +#### **10.3.5.4 Application time based charging price** + +This attribute defines the price per unit in the currency of the external host. + +#### **10.3.5.5 Communication cost: time based charging period** + +The service cost corresponds to the additional cost in the currency of the external host for using a videotex service. This cost is time-dependent. This attribute indicates the value of the period for the service cost. It may depend on the day and the time (for further study). + +#### **10.3.5.6 Communication cost: time based charging price** + +The service cost corresponds to the additional cost in the currency of the external host for using a videotex service. This cost is time-dependent. This attribute indicates the value of the price for the service cost per time unit. It may depend on the day and the time (for further study). + +### **10.3.6 Items for further study concerning the administrative structure** + +- a) Depending on the decisions of CCITT Study Group III on the interpretation of the item-over-limit facility, the introduction of an ACCOUNTING-INFORMATION-SE might be necessary so that the local host can provide the external host with limits on the: + - item cost; + - time-based charging; + - session cost;and the currently conversion. This is for further study. +- b) The exchange of total session cost at the end of the session, which might be achieved by introducing a charge-info and a charge-info-request attribute to the LOCAL-HOST-SE and to the EXTERNAL-HOST-SE, is for further study. +- c) Introducing value added taxes is for further study. +- d) Using a result parameter is for further study. +- e) In addition to a time-based charging for the communication cost, other methods could be taken into account (i.e. volume oriented). This is for further study. + +## **10.4 Special terminal facilities structure** + +This Special Terminal Facilities Structure is concerned with information which enables the external host to reconfigure the videotex terminal. The following categories of such information are identified: + +- screen format; +- dynamically redefinable character sets (DRCS); +- redefinable colours. + +NOTE – If the local host does not support these categories the structure is not used. + +The special terminal facilities structure consists of: + +- one SPECIAL-TERMINAL-FACILITIES-SE; +- zero, one or more REDEFINITION-ENTRY-SEs subordinate to the SPECIAL-TERMINAL-FACILITIES-SE. + +Terminal redefinition data shall be downloaded by the local host to the videotex terminal, before any blocks or fields are displayed. + +Figure 9 describes the hierarchy of the special terminal facilities structure. + +![A hierarchical diagram showing 'Special terminal facilities' in an oval at the top, connected by a vertical line to 'Redefinition entity' in an oval below it. Below the diagram is the text 'T0818680-94/d09'.](c76da2d73c064464051d1583fd80bb6b_img.jpg) + +``` + +graph TD; + A([Special terminal facilities]) --- B([Redefinition entity]); + +``` + +T0818680-94/d09 + +A hierarchical diagram showing 'Special terminal facilities' in an oval at the top, connected by a vertical line to 'Redefinition entity' in an oval below it. Below the diagram is the text 'T0818680-94/d09'. + +FIGURE 9/T.564 + +### 10.4.1 SPECIAL-TERMINAL-FACILITIES-SE + +This element contains the following application defined attributes: + +#### 10.4.1.1 Measurement unit + +This attribute specifies the unit used to express the dimensions attribute of the PAGE-SE. The following value is identified: + +- character box. + +#### 10.4.1.2 Dimensions + +This attribute consists of a pair of coordinates that specify the dimensions of the DDA of the videotex terminal. These dimensions are expressed in accordance with the measurement-unit attribute. + +### 10.4.2 REDEFINITION-ENTITY-SE + +This SE contains the following application defined attribute: + +#### 10.4.2.1 Redefinition coding + +This attribute is subdivided in two parts: it specifies the type and it specifies the syntax used to encode the redefinition content. The following redefinition types have been identified: + +- DRCS; +- colour redefinition. + +The following redefinition syntax have been identified: + +- interworking data syntax; +- data syntax I; +- data syntax II; +- data syntax III. + +#### 10.4.2.2 Redefinition content + +This attribute contains the actual redefinition data to be downloaded to the userw's terminal. This data will redefine a terminal facility as identified by the redefinition coding type. It consists of a sequel of bytes coded in accordance with the value of the redefinition coding attribute. + +# **Annex A** + +## **Layout structure and operational structure** + +(This annex forms an integral part of this Recommendation) + +This annex specifies the constituents of the layout structure and of the operational structure which are implicitly created at connection time. + +### *Profiles* + +- document profile; +- operational profile (for further study). + +### *Layout structure* + +- specific layout root. + +### *Operational structure* + +- DATA-ENTRY-SE; +- RESULT-SE; +- Result-Content-Portion; +- APPLICATION-CONTROL-MEMORY-SE; +- ADMINISTRATIVE-INFORMATION-SE; +- LOCAL-HOST-INFORMATION-SE; +- EXTERNAL-HOST-INFORMATION-SE; +- DOCUMENT-INFORMATION-SE; +- SPECIAL-TERMINAL-FACILITIES-SE. + +Some attributes of these objects are updated at connection time with values carried by parameters of the D-INITIATE service element (to be detailed). + +# **Annex B** + +## **Minimum size of data structures** + +(This annex is a provisional part of this Recommendation) + +This annex describes the minimum size of the data structures which must be supported by the local host. + +- Size of the display and the data entry structures: 2 K bytes. +- Size of application control memory structure: for further study. +- Number of characters that may be input in the fields: 500. +- Number of data entry subprograms: 24. +- Number of fields: 24. +- Number of rules: 24. +- Number of prompts: 24. +- Number of records: for further study. \ No newline at end of file diff --git a/marked/T/T-REC-T.571-199209-I_PDF-E/raw.md b/marked/T/T-REC-T.571-199209-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..b705c53fa8ffb3e27ef8bb79c0e05a24d3bae4e2 --- /dev/null +++ b/marked/T/T-REC-T.571-199209-I_PDF-E/raw.md @@ -0,0 +1,445 @@ + + +![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt. + +INTERNATIONAL TELECOMMUNICATION UNION + +# CCITT + +THE INTERNATIONAL +TELEGRAPH AND TELEPHONE +CONSULTATIVE COMMITTEE + +## T.571 + +(09/92) + +**TERMINAL EQUIPMENT AND PROTOCOLS +FOR TELEMATIC SERVICES** + +--- + +**TERMINAL CHARACTERISTICS +FOR THE TELEMATIC FILE TRANSFER +WITHIN THE TELETEX SERVICE** + +![CCITT logo: a stylized globe with the letters CCITT inside.](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +CCITT logo: a stylized globe with the letters CCITT inside. + +**Recommendation T.571** + +--- + +# FOREWORD + +The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988). + +Recommendation T.571 was prepared by Study Group VIII and was approved under the Resolution No. 2 procedure on the 18 September 1992. + +# --- CCITT NOTE + +In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized private operating agency. + +© ITU 1993 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +# CONTENTS + +| | <i>Page</i> | +|-------------------------------------------------------|-------------| +| INTRODUCTION..... | ii | +| 1 Scope..... | 1 | +| 2 Normative references ..... | 1 | +| 3 Definitions..... | 1 | +| 3.1 basic transfer mode..... | 1 | +| 3.2 document transfer mode..... | 2 | +| 3.3 binary file transfer..... | 2 | +| 3.4 EDIFACT ..... | 2 | +| 3.5 control document ..... | 2 | +| 3.6 mandatory ..... | 2 | +| 3.7 optional ..... | 2 | +| 4 Abbreviations ..... | 2 | +| 5 File Transfer ..... | 3 | +| 5.1 Essential features ..... | 3 | +| 5.2 Protocol aspects ..... | 3 | +| 5.3 Control document (optional)..... | 4 | +| 6 Mechanism used..... | 4 | +| 6.1 Capabilities exchange ..... | 4 | +| 6.1.1 BTM capability negotiation (mandatory)..... | 4 | +| 6.1.2 BFT capability negotiation (optional)..... | 4 | +| 6.1.3 EDIFACT capability negotiation (optional) ..... | 4 | +| 6.2 Invokation (start of a file) ..... | 5 | +| 6.2.1 BTM indication invokation (optional) ..... | 5 | +| 6.2.2 BFT indication invokation (optional) ..... | 5 | +| 6.2.3 EDIFACT indication invokation (optional) ..... | 5 | +| 6.2.4 File name indication invokation (optional)..... | 5 | +| 6.2.5 Free user field invokation (optional)..... | 5 | +| 6.3 File transfer..... | 5 | +| 6.3.1 File management..... | 5 | +| 6.4 End of the telematic file transfer..... | 6 | +| 6.5 Connection interrupt ..... | 6 | +| 7 Log books (if available) ..... | 6 | +| 8 Communication Identification Line (CIL) ..... | 6 | +| 9 Coding and structure of the control document ..... | 6 | +| 9.1 Telematic file transfer parameter coding ..... | 7 | +| 9.1.1 Parameters used in CDCL/RDCLP ..... | 7 | +| 9.1.2 Parameters used in CDS/CDC ..... | 8 | + +# INTRODUCTION + +This Recommendation defines the general rules required for the implementation of the Telematic file transfer for Teletex applications. + +It defines the technical mechanisms and coding used. + +*Note* – The use of this Recommendation for Facsimile Group 4 is for further study. + +# **TERMINAL CHARACTERISTICS FOR THE TELEMATIC FILE TRANSFER WITHIN THE TELETEX SERVICE** + +(1992) + +# **1 Scope** + +This Recommendation contains technical requirements for implementing the functionalities allowed by the telematic file transfer. The service requirements for telematic file transfer are described in Recommendation F.551. It explains the general and equipment features for the telematic file transfer which are required from a service point of view. + +The objective is to allow the transmission of a data file using the telematic file transfer possibilities with or without additional information concerning the file to be transmitted. + +# **2 Normative references** + +This Recommendation contains provision which, through references in the text, constitute provisions of this Recommendation. + +At the time of publication, the editions indicated were valid. All Recommendations are subject to revision. The CCITT secretariat maintains a list of the currently valid CCITT Recommendations. + +- [1] CCITT Recommendation T.62 (1988), *Control procedures for Teletex and G.4 facsimile services*. +- [2] CCITT Recommendation T.61 (1988), *Character repertoire and coded character sets for the international Teletex service*. +- [3] CCITT Recommendation T.50 (1988), *International Alphabet No. 5*. +- [4] CCITT Recommendation F.200 (1988), *Teletex service*. +- [5] CCITT Recommendation X.209 (1988), *Specification of basic encoding rules for Abstract Syntax Notation One (ASN.1)*. +- [6] CCITT Recommendation T.434 (1992), *Specification of binary file transfer*. +- [7] ISO/IEC 9735:1990, *Electronic data interchange for administration commerce and transport (EDIFACT) – Application level syntax rules*. +- [8] CCITT Recommendation F.551 (1992), *Service Recommendation for the Telematic File Transfer within the Telefax 3, Telefax 4, Teletex and Message Handling Services*. + +# **3 Definitions** + +For the purposes of this Recommendation, the following definitions apply. + +## **3.1 basic transfer mode** + +It provides the user of a telematic equipment with a means to exchange files of any kind (binary files, wordprocessor native format documents, bitmaps, etc.) without additional information. + +## 3.2 **document transfer mode** + +It provides the user of a telematic equipment with a means to exchange file of any kind with additional information, readable by the user or possibly automatically processed, included in a control document. + +In the Teletex environment the DTM is merged to the BTM feature. + +## 3.3 **binary file transfer** + +It provides the user of a telematic equipment with a means to exchange files of any kind with additional information automatically processed on the receiving side. The coding rules which apply to these additional information are technically aligned of those of FTAM (Recommendation X.209 [5]) coded. + +The binary file transfer is described in Recommendation T.434. Within the context of this Recommendation the diagnostic message mentioned in Recommendation T.434 is not used. + +## 3.4 **EDIFACT** + +It provides the user of a telematic equipment with a means to exchange files according to ISO/IEC 9735 [8] rules. + +## 3.5 **control document** + +It is a structured document which can either be used for automatic processing or, for file in an end-to-end communication or within a communication with an intermediate store-and-forward equipment. + +## 3.6 **mandatory** + +The feature described shall be used. + +## 3.7 **optional** + +The feature described can be used. + +# 4 **Abbreviations** + +The following abbreviations shall apply: + +| | | +|---------|------------------------------------------------------------------------| +| BFT | Binary File Transfer | +| BTM | Basic Transfer Mode | +| CDC | Command Document Continue | +| CDCL | Command Document Capability List | +| CDS | Command Document Start | +| CDPB | Command Document Page Boundary | +| CIL | Communication Identification Line | +| EDIFACT | Electronic Data Interchange for Administration, Commerce and Transport | +| IA5 | International Alphabet No. 5 | +| LI | Length Indicator | +| PGI | Parameter Group Identifier | + +| | | +|-------|--------------------------------------------| +| PV | Parameter Value | +| RDCLP | Response Document Capability List Positive | +| RDEP | Response Document End Positive | + +# 5 File Transfer + +## 5.1 *Essential features* + +- a) The transmission of a data file using the telematic file transfer possibilities consists of the transmission of the data file itself and, on user requirement, the transmission of information describing the file. +- b) The content of the data file may be any kind of coding. For the time being, three types of data files are taken into account. They are: + - Basic Transfer Mode (BTM); + - Binary File Transfer (BFT); + - EDIFACT. +- c) The BTM mode is the minimum requirement that an equipment must provide for participating in the Telematic File Transfer. +- d) Information describing the file may be found in Recommendation T.62 [1] session protocol element (i.e file name, tree user field). +- e) Additional information concerning a more detailed file description are defined in a control document (e.g file type, file coding, editor program, etc.). +- f) In case of BFT, the data structure contains attributes describing the file. These attributes are coded in ASN1 [5]. + +## 5.2 *Protocol aspects* + +- a) The telematic file transfer for Teletex equipments is based on Recommendation T.62 [1] session. +- b) Teletex or group 4 facsimile equipments may negotiate one or more of the features mentioned above. The mechanism used is the same as the one used for the private mode negotiation [i.e CDCL (Command Document Capability List) or RDCLP (Response Document Capability List Positive)]. +- c) The actual transmission (invocation) of one of the data files (BTM, BFT, EDIFACT) is indicated by means of a parameter within the Command Document Start (CDS) or Command Document Continue (CDC) session protocol element. + +Regarding to the case of the data file indication the following rules apply: + +- the capability negotiation must have succeeded; +- only one data file indication per transmission. + +The implementation of BTM is the minimum feature. + +- When the use of BTM has been agreed between the terminal equipments, a BTM indication may be transmitted in the CDS/CDC protocol elements. Information like file name and free user field may also be transmitted in the CDS/CDC protocol elements. + +Additional information, associated to the file to be transmitted, are described in the control document. + +- When the use of BFT has been agreed between the terminal equipments, a BFT indication may be transmitted in the CDS/CDC protocol elements. + +No additional information is transmitted in CDS/CDC protocol elements. + +- When the use of EDIFACT has been agreed between the terminal equipments, an EDIFACT indication may be transmitted in the CDS/CDC protocol elements. + +Information like file name and free user field may also be transmitted in the CDS/CDC protocol elements. + +- d) The telematic file transfer allows to link automatically the different parts of a document when it is transmitted in several parts. +- e) When telematic file transfer is used, the negotiation of the receiving memory capacity is strongly recommended. +Furthermore, a binary file which is not completely transmitted cannot be processed. +- f) When the telematic file transfer is supported, it should have priority over the manufacturer private mode. + +## 5.3 *Control document (optional)* + +To transfer a file using the BTM mode, a control document containing additional information may be sent during the same communication, prior to the file (see clause 7). + +The definition of the control document content is based on a standardized file description. + +The coding shall be in line with Recommendation T.61 [2]. + +The additional information which may be transmitted using a control document is defined in Recommendation F.551 [8]. + +# 6 **Mechanism used** + +## 6.1 *Capabilities exchange* + +Before sending any kind of file by the telematic file transfer features, it is mandatory to check the transmitting capabilities. + +### 6.1.1 *BTM capability negotiation (mandatory)* + +After the session establishment, the calling equipment shall negotiate the BTM mode. + +To this end, a BTM parameter (PGI = E3, PI = E9, PI = EA, see 9.1.1) shall be sent in the CDCL protocol element. + +If the called equipment provides the BTM mode, it sends back this parameter in the response RDCLP. If there is no BTM parameter in the RDCLP, the Telematic File Transfer will not be allowed. + +### 6.1.2 *BFT capability negotiation (optional)* + +A BFT parameter (PG1 = E3, PI = E9, PI = EE, see 9.1.1.) is sent in the protocol element CDCL indicating the capability of the calling equipment to transfer BFT files. The rules applying on BFT are described in Recommendation T.434 [6]. + +If the called equipment provides the BFT capability, it sends back the same BFT parameter in the RDCLP protocol element. + +If there is no BFT parameter in RDCLP, the binary file transfer will not be allowed. + +### 6.1.3 *EDIFACT capability negotiation (optional)* + +An EDIFACT parameter (PGI = E3, PI = E9, PI = EA, PI = EB, see 9.1.1) is sent in the protocol element CDCL indicating the capability of the calling equipment to be able to cope with EDIFACT files. The rules applying on EDIFACT are described in ISO/IEC 9735 [7]. + +If the called equipment provides the EDIFACT capability, it sends back the same EDIFACT parameter in the RDCLP protocol element. + +If there is no EDIFACT parameter in RDCLP, the EDIFACT file shall not be sent. Nevertheless, this file can be transferred, on user request, without the EDIFACT parameter as any other kind of file by using the BTM mode. + +## 6.2 *Invokation (start of a file)* + +### 6.2.1 *BTM indication invokation (optional)* + +One or several files may be transferred in the same session. + +The BTM is invoked by CDS or CDC carrying the BTM indication parameter (PGI = E3, PI = E9, PI = EA, see 9.1.2). The BTM parameter or any other additional information shall only be used in CDS or CDC when the BTM was successfully negotiated in the CDCL/RDCLP protocol elements. + +### 6.2.2 *BFT indication invokation (optional)* + +The terminal equipment invokes the BFT using the BFT indication parameter in CDS or CDC protocol elements (PGI = E3, PI = E9, PI = EE, see 9.1.2). + +### 6.2.3 *EDIFACT indication invokation (optional)* + +The terminal equipment invokes the EDIFACT using the EDIFACT indication parameter in CDS or CDC protocol elements (PGI = E3, PI = E9, PI = EA, PI = EB, see 9.1.2). + +### 6.2.4 *File name indication invokation (optional)* + +A file name may be transferred together with BTM parameter in order to identify a transparent file. The file name is also useful for facilitating the relationship between the file name attribut in the control document (if it is present) and the file. So, the file name used in the control document and the file name parameter in CDS or CDC should be identical. + +This information is transferred in CDS or CDC (PI = EC, see 9.1.2). + +Recommendation T.61 [2] coding shall be used. preferably with characters of the IA No. 5 Recommendation T.50 [3]. + +If the called equipment has already in its receiving memory file a file, the name of which is identical to the name contained in the file name parameter, it is necessary to avoid the destruction of these files. + +For assignment of a filename to a basic Teletex document, (i.e. transmitted in the Teletex service) the "FILE-name" parameter may also be used. + +In this case the CDS/CDC command contains only the parameters "new mode", "unique identification" and "file name". + +### 6.2.5 *Free user field invokation (optional)* + +On the sending side, the user may need to input some additional information (e.g reference, which software is running, etc.) in order to help the recipient of the file. This information is transferred in CDS or CDC (PI = ED, see 9.1.2). + +Recommendation T.61 [2] coding shall be used. preferably with characters of the IA No. 5 Recommendation T.50 [3]. + +On the receiving side, the information should be presented to the recipient (in the log book, somewhere on the screen when the file is locally selected, etc.). However, this information may be ignored by the receiving equipment. This information may also be automatically handled on the receiving side. + +## 6.3 *File transfer* + +The transfer procedure for the file transfer shall be fully in line with the Recommendation T.62 [1] (or X.215/X.225 and T.62 *bis*) (in particular the window mechanism). The checkpoints, Command Document Page Boundary (CDPB) should be set every 2 kilo-octets. + +*Note* – In some cases (e.g. long transmission delay times due to satellite links) other values for the checkpointing or window size may be necessary. + +### 6.3.1 *File management* + +Any service rules concerning the management of received documents or files are not relevant for the telematic file transfer. + +## 6.4 *End of the telematic file transfer* + +The end of the telematic file transfer is indicated by reception of the Response Document End Positive (RDEP) at the side which initiated the file transfer (sending of CDS or CDC). + +## 6.5 *Connection interrupt* + +In case of failure, any information for automatic linking is available on the receiving side provided by the CDC command. If the linking is not possible on the receiving side, the file shall be retransmitted as a whole. + +# 7 **Log books (if available)** + +When the telematic file transfer is provided, a location should be available, in addition to the minimum content of the communication log book. It should contain the indication “telematic file transfer” in the local national language. Furthermore it is desirable that a location should be reserved for containing each of the information: “BTM”, “BFT”, “EDIFACT”. For the BTM file transfer, the file name or the free user field could be indicated in this place. + +# 8 **Communication Identification Line (CIL)** + +Service rules concerning the management of the Communication Identification Line (CIL) do not apply for the files transmitted within telematic file transfer. + +# 9 **Coding and structure of the control document** + +*Note* – Recommendation T.61 [2] coding shall be used with the provision that the “backslash” character should be replaced by the “solidus” character. + +The definition of the parameters used below are described in Recommendation F.551 [8]. + +| | | | | +|-------|-----|---------------------------|-------------------------| +| CR FF | 6.1 | : ADDITIONAL INFORMATION: | | +| CR LF | 1 | : FILE NAME: | | +| CR LF | | [file name] | (72 characters maximum) | +| CR LF | 2 | : APPLICATION REFERENCE: | | +| CR LF | | [application reference] | (72 characters maximum) | +| CR LF | 3 | : TYPE: | | +| CR LF | | [coding] | (72 characters maximum) | +| CR LF | 4 | : ENVIRONMENT | | +| CR LF | 4.1 | : MACHINE: | | +| CR LF | | [machine] | (72 characters maximum) | +| CR LF | 4.2 | : OPERATING SYSTEM: | | +| CR LF | | [operating system] | (72 characters maximum) | +| CR LF | 4.3 | : PROGRAM: | | +| CR LF | | [program] | (72 characters maximum) | +| CR LF | 4.4 | : CHARACTER SET: | | +| CR LF | | [machine character set] | (72 characters maximum) | +| CR LF | 5 | : LAST REVISION: | | +| CR LF | | [last revision] | (72 characters maximum) | +| CR LF | 6 | : LENGTH: | | +| CR LF | | [file length] | (72 characters maximum) | +| CR LF | 7 | : PATH: | | +| CR LF | | [path name] | (72 characters maximum) | + +| | | | | +|-------|----|----------------------------------|-------------------------------------------| +| CR LF | 8 | : RESERVED: | | +| CR LF | | [reserved] | (72 characters maximum) | +| CR LF | 9 | : AUTHOR NAME: | | +| CR LF | | [author's name] | (72 characters maximum) | +| CR LF | 10 | : USER VISIBLE STRING: | | +| CR LF | | [[user's comments]] | (8 lines. 72 characters maximum per line) | +| CR LF | 11 | : FUTUR FILE LENGTH: | | +| CR LF | | [futur file length] | (72 characters maximum) | +| CR LF | 12 | : STRUCTURE: | | +| CR LF | | [structure] | (72 characters maximum) | +| CR LF | 13 | : PERMITTED ACTIONS: | | +| CR LF | | [permitted actions] | (72 characters maximum) | +| CR LF | 14 | : LEGAL QUALIFICATION: | | +| CR LF | | [legal qualification] | (72 characters maximum) | +| CR LF | 15 | : CREATION: | | +| | | [date and time of creation] | (72 characters maximum) | +| CR LF | 16 | : LAST READ ACCESS: | | +| CR LF | | [last read access] | (72 characters maximum) | +| CR LF | 17 | : IDENTITY OF THE LAST MODIFIER: | | +| CR LF | | [identity of the last modifier] | (72 characters maximum) | +| CR LF | 18 | : IDENTITY OF THE LAST READER: | | +| CR LF | | [identity of the last reader] | (72 characters maximum) | +| CR LF | 19 | : RECIPIENT: | | +| CR LF | | [recipient] | (72 characters maximum) | +| CR LF | 20 | : TFT VERSION: | | +| | | [TFT version] | (72 characters maximum) | +| CR LF | 21 | : COMPRESSED: | | +| | | [compression] | (72 characters maximum) | + +When only one [ ] is used, this element is included in one line. When [[ ]] is used, this element can be included in several line. + +## 9.1 *Telematic file transfer parameter coding* + +To be in line with Recommendation T.62 [1], this parameter shall be formed from the “private use” parameter. + +### 9.1.1 *Parameters used in CDCL/RDCLP* + +The parameters described in Figure 1/T.571 allow the negotiation of the capabilities between Teletex equipments. + +These parameters shall be sent in protocol element CDCL for exchange of the capabilities. + +The called equipment sends back its capabilities in protocol element RDCLP. + +| Parameter | Content and status | +|-------------------------------------|-------------------------------------------------| +| PGI: E3<br>LI: ? | NEW MODE (mandatory) | +| PI: E9<br>LI: 04<br>PV: 54 2E 4D 2E | Unique identification (mandatory) | +| PI: EA<br>LI: 01<br>PV: 00 | “T.M.”according to Rec. T.61<br>BTM (mandatory) | +| PI: EB (Note)<br>LI: 01<br>PV: 00 | EDIFACT (optional) | +| PI: EE<br>LI: 01<br>PV: 00 | BFT (optional) | + +*Note* – This parameter shall be used together with the BTM PI when the terminal is able to support EDIFACT files. + +FIGURE 1/T.571 + +#### **Parameters used in CDCL/RDCLP** + +### 9.1.2 *Parameters used in CDS/CDC* + +When the use of telematic file transfer has been agreed between the terminal equipments, the parameters described in Figure 2/T.571 should be transmitted in CDS or CDC commands. + +| Parameter | Content and status | +|-------------------------------------|--------------------------------------------------| +| PGI: E3<br>LI: ? | NEW MODE (mandatory) | +| PI: E9<br>LI: 04<br>PV: 54 2E 4D 2E | Unique identification (mandatory) | +| PI: EA (1)<br>LI: 01<br>PV: 00 | “T.M.” according to Rec. T.61<br>BTM (mandatory) | +| PI: EB (1, 2)<br>LI: 01<br>PV: 00 | EDIFACT indication (optional) | +| PI: EE (1)<br>LI: 01<br>PV: 00 | BFT indication (optional) | +| PI: EC<br>LI: 01<br>PV: XX | FILE NAME (optional)<br>12 octets maximum | +| PI: ED (1)<br>LI: 01<br>PV: XX | FREE USER FIELD (optional)<br>12 octets maximum | + +*Note 1* – These PI’s are absent if a basic document is to be indicated by means of the “file name” parameter. This allows the user to give a name to that document (see § 6.2.4). + +*Note 2* – This PI shall be used together with the BTM PI when an EDIFACT file is transferred. + +FIGURE 2/T.571 + +#### **Parameters used in CDS/CDC** \ No newline at end of file diff --git a/marked/T/T-REC-T.62-199303-I_PDF-E/raw.md b/marked/T/T-REC-T.62-199303-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..caa6f455d44ceecf2a61c09b4657a9f169847f69 --- /dev/null +++ b/marked/T/T-REC-T.62-199303-I_PDF-E/raw.md @@ -0,0 +1,5122 @@ + + +![ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol passing through it.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol passing through it. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## T.62 + +(03/93) + +**TELEMATIC SERVICES +TERMINAL EQUIPMENTS AND PROTOCOLS +FOR TELEMATIC SERVICES** + +**CONTROL PROCEDURES FOR TELETEX AND +GROUP 4 FACSIMILE SERVICES** + +**ITU-T Recommendation T.62** + +(Previously “CCITT Recommendation”) + +# FOREWORD + +The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecommunication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +ITU-T Recommendation T.62 was revised by the ITU-T Study Group VIII (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). + +--- + +# NOTES + +1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector. + +In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms “CCITT, CCIR or IFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. + +2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# CONTENTS + +| | <i>Page</i> | +|------------------------------------------------------------------------------------|-------------| +| 1 General | 1 | +| 1.1 Scope | 1 | +| 1.2 Fundamental principles | 1 | +| 1.3 Definitions | 2 | +| 2 Functions of the procedures | 2 | +| 2.1 General | 2 | +| 2.2 Background information | 4 | +| 3 Elements of procedure | 4 | +| 3.1 General | 4 | +| 3.2 Session commands, responses and parameters | 4 | +| 3.3 Session procedures | 8 | +| 3.4 Document commands, responses and parameters | 9 | +| 3.5 General rules for document elements of procedure | 15 | +| 3.6 Rules for document state diagrams | 16 | +| 4 Error recovery | 19 | +| 4.1 General principles | 19 | +| 4.2 Rules for checkpointing | 19 | +| 4.3 Acknowledgement window | 20 | +| 5 Coding | 21 | +| 5.1 Definition of terms used in coding | 21 | +| 5.2 Principles of coding | 21 | +| 5.3 Coding of length indicators | 24 | +| 5.4 Coding of command and response identifiers for session elements | 25 | +| 5.5 Coding of command and response identifiers for document elements | 25 | +| 5.6 Coding of parameter group identifiers and parameter identifiers | 25 | +| 5.7 Parameter values | 28 | +| Annex A – Definitions | 40 | +| A.1 General | 40 | +| A.2 Terms specific to session procedures | 41 | +| A.3 Terms specific to document procedures | 42 | +| Annex B – Telematic modes of operation | 43 | +| B.1 Introduction | 43 | +| B.2 Telematic modes of operation | 43 | +| B.3 Relationship between Telematic modes of operation and the OSI session services | 43 | +| Annex C – Definition of valid/invalid session protocol data units | 45 | +| C.1 Introduction | 45 | +| C.2 Invalid protocol data units (PDUs) (definition and rules) | 45 | +| C.3 Valid PDUs (rules for mandatory acceptance of PDUs) | 45 | +| Annex D – General description and rules of operation for state diagrams | 46 | + +| | <i>Page</i> | +|-------------------------------------------------------------------------------------------|-------------| +| Annex E – Types of document | 47 | +| E.1 General | 47 | +| E.2 Normal document | 47 | +| E.3 Operator document (optional) | 47 | +| E.4 Control document | 47 | +| E.5 Monitor document (optional) | 47 | +| Annex F – Interactive session protocol and typed data transfer for the Telematic services | 48 | +| Annex G – Detailed state transition diagrams for session/document procedures | 48 | +| G.1 General | 48 | +| G.2 Description on notations | 48 | +| G.3 Service primitives | 50 | +| G.4 Detailed state transition diagrams for the basic services | 55 | +| Annex H – State transition tables for session/document procedures | 60 | +| H.1 General | 60 | +| H.2 Notation details | 60 | +| H.3 State tables | 61 | + +# **CONTROL PROCEDURES FOR TELETEX AND GROUP 4 FACSIMILE SERVICES** + +*(Malaga-Torremolinos, 1984; amended at Melbourne, 1988 and at Helsinki, 1993)* + +# **1 General** + +## **1.1 Scope** + +**1.1.1** Recommendation F.200 lays down the provisions for the operation of the automatic international Teletex service. On the technical side, Recommendation T.60 specifies the requirements for international compatibility between Teletex terminals and Recommendation T.61 defines the character repertoire and coded character sets for the international Teletex service. + +**1.1.2** Recommendation F.161 defines the rules to be followed in the Group 4 facsimile service. On the technical side, Recommendations T.563, T.503 and T.521 specify the requirements for Group 4 facsimile apparatus and Recommendation T.6 defines the Group 4 facsimile coding scheme and facsimile control functions. + +**1.1.3** The T.400 – Series Recommendations define the document interchange protocol which may be used when services other than basic Teletex are utilized; e.g. Group 4 facsimile, mixed-mode operation, etc. + +**1.1.4** Network-dependent communication procedures for call establishment and termination are defined in Recommendations T.60 and T.563 for the Teletex and Group 4 facsimile services, respectively. + +**1.1.5** This Recommendation defines the end-to-end procedures to be used within the Teletex and Group 4 facsimile services. + +**1.1.6** Specifically, this Recommendation concerns the end-to-end control procedures that are network-independent. The network-dependent procedures forming a network-independent transport service are specified in Recommendations T.70 and, as applicable, T.71. + +**1.1.7** The procedure described in this Recommendation should also be used between a Teletex terminal and a Teletex/telex conversion facility (see Recommendations F.201, T.60 and T.390) and when a Teletex or G4 facsimile terminal takes an access to IPMS (see Recommendations F.422, T.60, T.330 and T.563). + +**1.1.8** Interworking between Teletex and services other than telex and IPMS, and between Group 4 facsimile and services other than IPMS is for further study. + +**1.1.9** This Recommendation assumes that the terminal initiating a call is the terminal regarded as responsible for call charges and that it retains full control of the call. + +**1.1.10** The provisions in this Recommendation are to be regarded as a first stage in the establishment of Teletex and Group 4 facsimile services in accordance with Recommendations F.200, T.60, T.61 and T.70 as defined in 1980 and Recommendations F.161, T.5, T.6 and T.73 as defined in 1984, respectively. Enhancements and additions to these Recommendations must ensure compatibility with established services. + +## **1.2 Fundamental principles** + +**1.2.1** The relationship between the control procedures in this Recommendation and the transport service shall respect the principle that the higher level procedures require the transport service to preserve the structure of blocks, which may be of arbitrary size, given to it by the session level for transmission. Only one session command or response is allowed in such a block. Only one document command or response is allowed in a CSUI or RSUI field (command or response session user information). + +**1.2.2** The sending terminal is responsible for verifying the correct delivery of the information in its document to the recipient's physical media, i.e. store, hard copy device. This may include linking and other relevant information. + +## 1.3 Definitions + +**1.3.1** Terms and their definitions are listed in Annex A. Where appropriate, each definition mentions the control procedures to which it refers. + +**1.3.2** Some of the terms used in this Recommendation have been defined in ways that may differ from the meanings of similar terms in other Recommendations. + +# 2 Functions of the procedures + +## 2.1 General + +**2.1.1** The broad functional categories provided to implement the control procedures are listed in Tables 1 and 2. + +TABLE 1/T.62 +**Session commands and responses** + +| Command | Response | Abbreviation | Reference<br>(subclause) | +|------------------------------------|------------------------------------------|--------------|--------------------------| +| Session establishment and clearing | | | | +| Command session start | | CSS | 3.2.1 | +| | Response session start positive | RSSP | 3.2.2 | +| | Response session start negative | RSSN | 3.2.3 | +| Command session end | | CSE | 3.2.4 | +| | Response session end positive | RSEP | 3.2.5 | +| Command session abort | | CSA | 3.2.6 | +| | Response session abort positive | RSAP | 3.2.7 | +| Information transfer | | | | +| Command session user information | | CSUI | 3.2.8 | +| | Response session user information | RSUI | 3.2.9 | +| Session management | | | | +| Command session change control | | CSCC | 3.2.10 | +| | Response session change control positive | RSCCP | 3.2.11 | + +TABLE 2/T.62 + +### **Document commands and responses** + +| Command | Response | Abbreviation | Reference<br>(subclause) | +|-------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------|-------------------|--------------------------| +| Document control | | | | +| Command document start | | CDS <sup>a)</sup> | 3.4.1 | +| Command document continue | | CDC <sup>a)</sup> | 3.4.3 | +| Commande document capability list | | CDCL | 3.4.4 | +| | Response document capability list positive | RDCLP | 3.4.5 | +| Command document end | | CDE <sup>b)</sup> | 3.4.6 | +| | Response document end positive | RDEP | 3.4.7 | +| Command document discard | | CDD | 3.4.8 | +| | Response document discard positive | RDDP | 3.4.9 | +| Command document resynchronize | | CDR | 3.4.10 | +| | Response document resynchoronize positive | RDRP | 3.4.11 | +| Information transfer | | | | +| Command document user information | | CDUI | 3.4.12 | +| Error recovery | | | | +| | Response document general reject | RDGR | 3.4.2 | +| Command document page boundary | | CDPB | 3.4.13 | +| | Response document page boundary positive | RDPBP | 3.4.14 | +| | Response document page boundary negative | RDPBN | 3.4.15 | +| a) RDGR is used as a negative response to this command. A specific negative response is not required.<br>b) The negative response to this command is RDPBN. | | | | + +**2.1.2** The procedural elements have also been listed in the appropriate categories since the definitions of the elements together with their associated rules completely specify the functions of the procedures. + +## **2.2 Background information** + +NOTE – Clause 2 is given as an aid for the understanding of the procedures. The exact definitions of the control procedures are given in subsequent Clauses of the Recommendation. + +### **2.2.1 Exchange of service identification** + +**2.2.1.1** Two terminals, when connected by a transport service, will, at session establishment, exchange information identifying whether they are participating in the Telematic services and thus they will invoke the relevant service facilities and the associated protocol. + +### **2.2.2 Negotiation of optional capabilities** + +**2.2.2.1** Two methods are provided. The first is used at session initiation to exchange a limited list of capabilities. The second method may be used when required, after session initiation, to indicate the sender's requirements for extended capabilities. + +### **2.2.3 Negotiation of storage requirements** + +**2.2.3.1** Storage availability can be indicated in the following ways: + +- a) When a Teletex session is established, it is implicitly assumed that there is adequate receive memory for the call. Exceptionally a receiver memory overflow will occur. The continued sending of the document from the source will be stopped by the sink. The sink shall indicate the reason for stopping the transmission. +- b) When a Group 4 facsimile session is established, it can only be assumed that the called terminal has adequate recording paper to print at least one page of information (for basic Class 1 apparatus). Negotiation of storage requirements is mandatory for Group 4 Classes 2 and 3 facsimile apparatus. Having negotiated this requirement, exceptionally, a receive memory overflow may occur. The continued sending of the document from the source will be stopped by the sink. The sink shall indicate the reason for stopping the transmission. +- c) The provision is also made in the procedure for a mandatory indication that the ability of the receiving terminal to continue to accept traffic is jeopardized. +- d) The control procedure also provides the possibility to investigate the storage availability at the receiving terminal prior to the transmission of a document. + +# **3 Elements of procedure** + +## **3.1 General** + +**3.1.1** The subclauses below contain elements of procedure and rules of use which, when combined, define the control procedures. + +**3.1.2** Definitions applying to the elements of procedure may be found in Annexes A and B. + +**3.1.3** Annex D describes the session suspension function, which is not applicable to the basic services. + +## **3.2 Session commands, responses and parameters** + +(For a summary of session commands and responses, see Table 1.) + +### **3.2.1 Command session start (CSS)** + +**3.2.1.1** The CSS initiates entry into a session. + +**3.2.1.2** Command parameters are: + +- a) *Service identifier* – This mandatory parameter identifies whether the sender of this command intends to use the Telematic service. +- b) *Terminal identifier* – This mandatory parameter identifies the calling terminal in accordance with the terminal identification specified in Recommendation F.200. +- c) *Date and time* – This mandatory parameter gives date and time information as specified in Recommendation F.200. + +- d) *Additional session reference number* – This number shall be used in addition to the basic session reference (terminal identifier of the called terminal, terminal identifier of the calling terminal, date and time) when the basic session reference is not sufficient to uniquely identify the session and such unique identification is required. If the additional session reference number is not used, the parameter shall not be included. +- e) *Non-basic terminal capabilities* – These parameters indicate which of the non-basic terminal capabilities listed in Table 3 for the Teletex service are available as receiving capabilities of the sender of this command. These parameters are mandatory if the terminal is capable of any of the specific functions listed in this table. Absence of the parameter indicates that the specific function is not available. +- f) *Non-basic session capabilities* – If used, this non-mandatory parameter indicates which non-basic session capabilities are available as receiving capabilities of the sender of this command. + + +NOTE – Examples of the use of this parameter are session suspension (see Annex D) and negotiation of the window size for checkpoint (see 3.3.2.7 and 4.3). +- g) *Inactivity timer* – This non-mandatory parameter is used to negotiate the value of the inactivity timer (see 4.1.2 and 5.7.2.11). +- h) *Session service functions* – This non-mandatory parameter is used to specify the session service capabilities available. This parameter is used for the interactive session protocol (ISP) and typed data transfer (TDX). + + +NOTE – Examples of the use of this parameter are for further study in association with Annex F. +- i) *Session user data* – This non-mandatory parameter is used to convey data of the presentation and/or application protocol(s). All information necessary to negotiate the document interchange protocol parameters defined in the T.400-Series Recommendations is contained in this parameter field. +- j) *Non-standardized capabilities* – This non-mandatory parameter is used to ascertain compatibility regarding the use of non-standardized terminal capabilities. + + +The first octet following the parameter identifier and the length indicator identifies a particular country. The meaning and code assignments of subsequent octets are defined by the indicated country. +- k) *Private use parameters* – These parameters are not mandatory. Their definition and use are not standardized. + +TABLE 3/T.62 + +#### **Non-basic terminal capabilities included in CSS** + +| Parameter | Function | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Control character sets | Reverse line feed | +| Page formats | ISO A4 vertical and horizontal orientation | +| Miscellaneous terminal capabilities | Character spacing of 2.12 mm (12 characters per 25.4 mm)<br>Character spacing of 1.69 mm (15 characters per 25.4 mm)<br>Line feed parameter value of one spacing of 3.175 mm<br>Line feed parameter value of one spacing of 0.5, 1.0, 1.5 and two spacings of 5 mm | +| NOTE – The definitions of these presentation capabilities may be found in Recommendation T.60. Future extensions and private-use capabilities are to be accommodated with CDCL. | | + +### 3.2.2 Response session start positive (RSSP) + +**3.2.2.1** The RSSP shall be used to acknowledge entry into a session. It indicates that the CSS command has been understood and is in a correct format. + +#### 3.2.2.2 Response parameters are: + +- a) *Service identifier* – This mandatory parameter identifies whether the sender of this response intends to use the Telematic service. + +##### NOTES + +- 1 For the basic Teletex services, the service identifiers in RSSP and CSS must be identical. + - 2 In case of interconnections between the terminals of different services, the service identifiers in RSSP and CSS may not be identical. +- b) *Terminal identifier* – This mandatory parameter provides the terminal identification of the sender of the RSSP in accordance with the terminal identification specified in Recommendation F.200. + - c) *Date and time* – This mandatory parameter must be identical to the corresponding parameter in the CSS. It is used in conjunction with the terminal identifications of both terminals in a session as a reference to that session. + - d) *Additional session reference number* – If used in the CSS and if used by the receiver of CSS, this parameter shall have the same value as in the CSS. In this case, it shall also be used, together with the basic session reference when referring to this session in a CDC command. If it is not used by the receiver of CSS, it shall not appear in the RSSP. + - e) *Non-basic terminal capabilities* (i.e. those available as receiving capabilities of the sender of the RSSP) – The same conditions apply as for 3.2.1.2 e) above. + - f) *Non-basic session capabilities* – As for 3.2.1.2 f) above. + - g) *Session control functions* – This parameter is used to indicate “request control” and “request session suspension” as defined in this Recommendation. + - h) *Inactivity timer* – As for 3.2.1.2 g) above. + - i) *Session service functions* – As for 3.2.1.2 h) above. + - j) *Session user data* – As for 3.2.1.2 i) above. + - k) *Non-standardized capabilities* – As for 3.2.1.2 j) above. + - l) *Private use parameters* – As for 3.2.1.2 k) above. + +### 3.2.3 Response session start negative (RSSN) + +**3.2.3.1** The negative response indicates that the session was not entered by the receiver of the CSS. It is not mandatory to indicate the reasons for rejection. A non-mandatory private-use parameter may be used with this response. + +NOTE – It should be noted that existing equipment may send an RSSN without any parameter fields. This shall not be regarded as an error. + +#### 3.2.3.2 Response parameters are: + +- a) *Service identifier* – This mandatory parameter identifies whether the sender of this response intends to use the telematic service. + +##### NOTES + +- 1 For the basic services, the service identifiers in RSSN and CSS must be identical. + - 2 In case of interconnections between the terminals of different services, the service identifiers in RSSN and CSS may not be identical. +- b) *Terminal identifier* – This mandatory parameter provides the terminal identification of the sender of the RSSN in accordance with the terminal identification specified in Recommendation F.200. + - c) *Date and time* – This mandatory parameter must be identical to the corresponding parameter in the CSS. It is used in conjunction with the terminal identifications of both terminals in a session as a reference to that session. + - d) *Additional session reference number* – If used in the CSS and if used by the receiver of CSS, this parameter shall have the same value as in the CSS. If it is not used by the receiver of CSS, it shall not appear in the RSSN. + - e) *Non-basic terminal capabilities* (i.e. those available as receiving capabilities of the sender of the RSSN) – The same conditions apply as for 3.2.1.2 e) above. + - f) *Non-basic session capabilities* – As for 3.2.1.2 f) above. + +- g) *Reason for sending the negative response* – This parameter is used to indicate the reason for sending the RSSN. The parameter value may be presented to an operator when received. One of the following reasons may be used as a value of the parameter: + - no reason given; + - temporarily unable to enter the session. Shall be used e.g. in the case of memory full; + - text message of maximum 69 characters. It may be possible for the operator to enter this message from the keyboard. +- h) *Session service functions* – As for 3.2.1.2 h) above. +- i) *Session user data* – As for 3.2.1.2 i) above. +- j) *Private use parameter* – As for 3.2.1.2 k) above. + +### **3.2.4 Command session end (CSE)** + +**3.2.4.1** The CSE is used for normal (or error-free) termination of a session. + +NOTE – A parameter is reserved to indicate whether the transport connection is to be cleared. Absence of this parameter will cause the transport connection to be cleared. + +### **3.2.5 Response session end positive (RSEP)** + +**3.2.5.1** The RSEP indicates to the calling terminal that the called terminal has entered the idle state in an orderly manner. + +### **3.2.6 Command session abort (CSA)** + +**3.2.6.1** The CSA may be used at any time by either terminal to terminate a session, whenever a condition is detected indicating that the session cannot be continued successfully. CSA shall only be used when there is no other suitable way of ending the session. + +**3.2.6.2** One of the following reasons for the abnormal termination of the session must be given as a CSA parameter: + +- a) local terminal error; +- b) unrecoverable procedural error; +- c) reason not defined. + +NOTE – One value is reserved to indicate whether the transport connection is to be cleared. + +### **3.2.7 Response session abort positive (RSAP)** + +**3.2.7.1** The RSAP response indicates to the sender of a CSA command (either the source or the sink terminal) that the receiver of CSA has entered the idle state in an orderly manner. + +### **3.2.8 Command session user information (CSUI)** + +**3.2.8.1** The CSUI is used to indicate to the receiver that the associated information field of this command conveys command, parameters and information for the document procedures. + +**3.2.8.2** CSUI does not call for a response. There is no relationship between this command and the response RSUI. + +### **3.2.9 Response session user information (RSUI)** + +**3.2.9.1** The RSUI is used to indicate to the receiver of this response (source) that the associated information field conveys response and parameters for the document procedures. A non-mandatory parameter, session control function, may be used with this response. + +**3.2.9.2** This RSUI response is not related to any CSUI command. + +**3.2.9.3** The parameter, session control functions, is sent with RSUI in conjunction with document response. Use of this parameter with RSUI but without an associated document response is permitted only in the case where the session may intentionally be inactive for a period of time. In this case, when no document responses are being generated, use of the session control functions parameter is permitted without an associated document response. For the Teletex service, this requires a preceding negotiation of the inactivity timer to a value different from the default value. + +### **3.2.10 Command session change control (CSCC)** + +**3.2.10.1** In the two-way alternate (TWA) mode CSCC changes the source/sink relationship between the two terminals. + +NOTE – A signal for request control is available in some responses (see coding scheme). It may be used to indicate that a terminal sending this signal has information to transmit. The terminal receiving this signal is not required to take any action if this signal is detected. + +### **3.2.11 Response session change control positive (RSCCP)** + +**3.2.11.1** The RSCCP indicates to the sender of the CSCC that the sink terminal intends to enter the session sending state. + +## **3.3 Session procedures** + +### **3.3.1 Session modes of operation** + +**3.3.1.1** The following provisions concern the TWA mode of session operation: + +- a) the basic protocol provides the capability of the TWA mode; +- b) at session initiation, the sender of the CSS is defined as being the current source of any text information and is therefore the source terminal; +- c) the CSCC exchanges the source/sink relationship between the two terminals. The CSCC command should only be invoked outside document boundaries; +- d) only the terminal that is currently the source terminal may send the CSCC; +- e) there is no requirement for sending text information prior to sending a CSCC; +- f) when the called terminal has finished transmitting text, it shall hand back the right of sending text to the calling terminal. Only the calling terminal is allowed to send CSE. + +**3.3.1.2** The following provisions concern the one-way communication (OWC) mode of session operation: + +- a) the OWC mode is achieved by the CSS sender not issuing a CSCC; +- b) there is no requirement to send text information; +- c) this mode is a subset of TWA. + +### **3.3.2 Rules for session elements of procedure** + +**3.3.2.1** Only the terminal that has established the transport connection (the calling terminal) shall send CSS. + +**3.3.2.2** It is the responsibility of the sender of CSS to examine the parameters of RSSP and to determine whether the session should continue. If it is not to be continued, the session shall be ended normally (by CSE). + +**3.3.2.3** In continuing the session, neither terminal is permitted to use any procedure or to send any information that does not comply with the receiving capabilities indicated by the session partner in the service identifier and non-basic session and terminal capabilities parameters of the CSS/RSSP exchange at session initiation and/or by the parameters of CDCL/RDCLP exchange. + +**3.3.2.4** In the TWA or OWC mode, only the sender of CSS may send CSE when he is the current source. + +**3.3.2.5** In the TWA mode, the recipient of both CSS and CSCC must terminate his period as source by sending CSCC. + +**3.3.2.6** In any mode of operation, CSA may be sent at any time by either terminal whenever a condition is detected indicating that the session cannot be successfully continued (e.g. due to failure or charging problems). The following rules are applied to the session abort procedure: + +- a) the session abort procedure is in general completed when the sender of a CSA command receives an RSAP response; + +- b) the terminal sending the CSA waits for a response RSAP. In state 14, all other commands or responses received will be discarded. If RSAP is not received before a time-out (e.g. T = 4 seconds), the terminal that send the CSA clears the transport connection. + +NOTE – In all cases the transport connection must be cleared when the CSA timer has expired. + +#### **3.3.2.7** The following rules should apply to the use of window size: + +- a) the indication of the window size parameter is not mandatory for the Teletex service, but is mandatory for the Group 4 facsimile service. It may have a value in the range of 1 to 255. The absence of this parameter in CSS or its corresponding response must be interpreted as the default value of three for the Teletex service; +- b) all the Teletex terminals should support a window size of 3. Group 4 facsimile terminals of Classes 2 and 3 should be able to support a window size of 3 when interworking with Teletex. Enhanced Teletex terminals (e.g. with mixed-mode capability) and all Group 4 facsimile terminals may require other window sizes; +- c) the rule for the use of window size is that the source terminal is free to use any window size that does not exceed the window size indicated by the sink terminal (in CSS or its corresponding response); +- d) if the sender of CSS or its corresponding response is a basic Teletex terminal which does not indicate any parameter for the window size, the receiver should be aware that the sender may ignore any window size indicated and use the window size of 3. + +**3.3.2.8** Figure 1 is a state transition diagram for TWA and OWC session modes. The change control commands and responses [marked with an “a” in the diagram] do not apply to the OWC mode. The general description and rules of operation for state diagrams may be found at Annex D. + +**3.3.2.9** In a session where the use of the RSUI with request control is permitted (as specified in 3.2.9.3), the following will apply: + +- a) an RSUI requesting control may be received after giving control and before receiving any valid session protocol element. This shall not be regarded as a procedural error and shall be discarded; +- b) an RSUI requesting control may be received after sending a CSE and before receiving an RSEP. This shall not be regarded as a procedural error and shall be discarded. + +## **3.4 Document commands, responses and parameters** + +(For summary of document commands and responses, see Table 2.) + +### **3.4.1 Command document start (CDS)** + +**3.4.1.1** The CDS indicates the start of a document to the receiver of this command. It also indicates the start of the first page. + +**3.4.1.2** Command parameters are: + +- a) *Service interworking identifier* – Not a mandatory field (see 3.5.2). + +NOTE – When communicating with a conversion facility, an identifier may be required for: + + - i) Teletex/telex interworking – the identifier will indicate that the document(s) has been prepared in accordance with the rules given in Recommendations F.200, T.90 and T.91; + - ii) Teletex/Videotex interworking – for further study; + - iii) Teletex/facsimile interworking – For further study. +- b) *Document type identifier* – Not a mandatory field. If a normal document is used, this parameter shall not be indicated. If other types of document are used, the inclusion of this field is obligatory (for a description of types of document, see Annex E). +- c) *Document reference number* – (See 4.2.9). +- d) *Indication of required terminal capability* (standardized or private use) – Not a mandatory field, however, this parameter must be used if standardized optional terminal capabilities are required for the document. + +- e) *Session user data* – This non-mandatory parameter is used to convey data of the presentation and/or application protocol(s). All information necessary to negotiate the document interchange protocol parameters defined in the T.400-Series Recommendations is contained in this parameter field. +- f) *Private use parameters (not mandatory)* – Definition of such parameters is not standardized. + +**3.4.1.3** There is no response to CDS except in the case of an error, for which RDGR is used. + +### **3.4.2 Response document general reject (RDGR)** + +**3.4.2.1** The RDGR may be used by the sink to indicate to the source that a procedural error has occurred and that resynchronization is requested. The bit pattern of command or response up to and including the error shall be returned to the source. Only the first detected error within a command or response must be processed by this method. + +**3.4.2.2** The response parameter is the bit pattern required by 3.4.2.1. + +**3.4.2.3** It is the responsibility of the terminal receiving an RDGR response to take appropriate action. + +NOTE – Use of RDGR for other kinds of error is for further study. + +### **3.4.3 Command document continue (CDC)** + +**3.4.3.1** The CDC indicates to the receiver of this command the continuation of transmission of a document that has previously been partially transmitted. + +**3.4.3.2** Command parameters are: + +- a) *Document linking information*, in order to identify the previous transmission of the partial document, including: + - the checkpoint reference number (see 4.2.7) from which the transmission is being continued; + - the document reference number, which shall be the same as the document reference number in the CDS; + - the session reference information identifying the session in which the first part of the document was sent. + +#### NOTES + +1 If several continuations are required to complete transmission of a document, all are linked to the partial transmission in which the CDS was used. The sequence of checkpoint reference numbers is then used to identify the correct sequencing for linking and all such continuations shall be transmitted in this sequence. + +2 It is the responsibility of the receiving terminal to discard any text information that has been duplicated in the process of continuation of an interrupted transmission. + +3 The checkpoint reference number appearing in CDC is the last checkpoint reference number for which a positive acknowledgement has been received. + +- b) *Service interworking identifier* – Not a mandatory field [see the note under 3.4.1.2 a) for CDS]. +- c) *Document type identifier* – Not a mandatory field. If a normal Teletex document is used, this parameter shall not be indicated. If other types of document are used, the inclusion of this field is obligatory (for a description of types of document, see Annex E). +- d) *Document reference number* (of the current session) – See 4.2.9. +- e) Optionally, any other parameter field(s) that appeared in the CDS command at the start of the document may be repeated as parameter(s) in CDC. Indication of required terminal capability is mandatory if standardized optional terminal capabilities are required for the document. A terminal receiving a CDC that does not contain all of the terminal capabilities should not reject the continuation of the document. +- f) *Session user data* – This non-mandatory parameter is used to convey data of the presentation and/or application protocol(s). All information necessary to negotiate the document interchange protocol parameters defined in the T.400-Series Recommendations is contained in this parameter field. + +**3.4.3.3** There is no response to CDC except in the case of an error, for which RDGR is used. + +From any state +except 14 + +From any state + +S-CSA + +R-CSA + +7 +Response +pending + +14 +Demand +response + +S-RSAP + +R-RSAP + +0 +Idle + +Error states + +S-RSEP + +R-CSS + +S-CSS + +R-RSEP + +S-RSSN + +R-RSSN + +6 +Response +pending + +1 +Response +pending + +8 +Demand +response + +13 +Demand +response + +R-CSE + +S-RSSP + +R-RSSP + +S-CSE + +2 +Session +receive + +9 +Session send and +transmission control + +R-CSUI + +S-RSUI + +S-CSUI + +R-RSUI + +R-RSCCP<sup>a)</sup> + +R-CSCC<sup>a)</sup> + +S-RSCCP<sup>a)</sup> + +S-CSCC<sup>a)</sup> + +5 +Demand +response + +3 +Response +pending + +12 +Response +pending + +10 +Demand +response + +S-CSCC<sup>a)</sup> + +S-RSCCP<sup>a)</sup> + +R-CSCC<sup>a)</sup> + +R-RSCCP<sup>a)</sup> + +4 +Session +send + +11 +Session receive +and transmission +control + +R-RSUI + +S-CSUI + +S-RSUI + +R-CSUI + +Called terminal + +Calling terminal + +T0817380-94/d01 + +<sup>a)</sup> These “change control” commands and responses do not apply to the OWC. + +FIGURE 1/T.62 + +**State transition diagram for TWA and OWC session modes** + +**Recommendation T.62 (03/93) 11** + +![State transition diagram for TWA and OWC session modes showing states 0-14 and transitions between them for Called and Calling terminals.](b39862f3c688ad67d99be31e05d5bab4_img.jpg) + +``` + +stateDiagram-v2 + [*] --> 7: R-CSA (From any state except 14) + [*] --> 14: S-CSA (From any state) + 7 --> 0: S-RSAP + 14 --> 0: R-RSAP + + state "Called terminal" as Called { + 0 --> 1: R-CSS + 0 --> 6: S-RSEP + 1 --> 0: S-RSSN + 1 --> 2: S-RSSP + 6 --> 2: R-CSE + 2 --> 2: R-CSUI / S-RSUI + 2 --> 5: R-RSCCP(a) + 2 --> 3: R-CSCC(a) + 5 --> 4: S-CSCC(a) + 3 --> 4: S-RSCCP(a) + 4 --> 4: R-RSUI / S-CSUI + } + + state "Calling terminal" as Calling { + 0 --> 8: S-CSS + 0 --> 13: R-RSEP + 8 --> 0: R-RSSN + 8 --> 9: R-RSSP + 13 --> 9: S-CSE + 9 --> 9: S-CSUI / R-RSUI + 9 --> 12: S-RSCCP(a) + 9 --> 10: S-CSCC(a) + 12 --> 11: R-CSCC(a) + 10 --> 11: R-RSCCP(a) + 11 --> 11: S-RSUI / R-CSUI + } + +``` + +State transition diagram for TWA and OWC session modes showing states 0-14 and transitions between them for Called and Calling terminals. + +### **3.4.4 Command document capability list (CDCL)** + +**3.4.4.1** The CDCL initiates an exchange of information to enable a check of the terminal capabilities (both standardized and private use). The command shall include a list of receiving capabilities that may be needed at the receiver by the sender of this command. + +**3.4.4.2** The command may also be used to investigate the storage capability of the remote terminal. The required amount of storage (given in kilo-octets) is indicated in a parameter of the command in this case. + +**3.4.4.3** Command parameters are the list of receiving capabilities and the required amount of storage. + +**3.4.4.4** The CDCL command should only be invoked outside document boundaries. + +**3.4.4.5** The CDCL command may be used to negotiate the value of the inactivity timer. The value of the inactivity timer that the sender of this command wishes to use is indicated in a parameter field of this command. + +**3.4.4.6** The CDCL command may be used to convey the session user data of the presentation and/or application protocol(s). All information necessary to negotiate the document interchange protocol parameters defined in the T.400-Series Recommendations is contained in this parameter field. + +**3.4.4.7** The CDCL command may be used to ascertain compatibility regarding the use of non-standardized capabilities. + +### **3.4.5 Response document capability list positive (RDCLP)** + +**3.4.5.1** The RDCLP response is sent by the receiver of a CDCL command as a positive acknowledgement of the command. + +**3.4.5.2** If the CDCL command includes the information to check the non-basic Teletex terminal capabilities, the corresponding RDCLP response has to contain one of the following: + +- a) confirmation that all the requested capabilities are available at the receiver by use of “acceptance of CDCL parameters”; +- b) a list of capabilities available at the receiver by use of the “non-basic Teletex terminal capabilities” parameter. This will indicate one of the following: + - the complete list of all the capabilities requested in the CDCL; + - a list of the requested capabilities that are available at the receiver. Absence of parameters associated with non-basic capabilities indicated that the requested capabilities are not available at the receiver; + - a complete list of non-basic receiving capabilities, irrespective of the requested ones. + +**3.4.5.3** If the CDCL is used for memory negotiation, one of the following shall be included in the RDCLP: + +- a) confirmation that the amount of memory requested is available and has been reserved; +- b) indication of the available (and reserved) amount of memory (in kilo-octets); +- c) indication that the requested memory capacity cannot now be reserved; +- d) indication that the available memory cannot be estimated (through either explicit indication or the absence of a memory negotiation parameter in a response to a response to a CDCL with a memory request). + +#### **NOTES** + +1 Storage that has been reserved by the CDCL command can be released after session termination or when a new CDCL with storage requirement indication is received. + +2 The use of the memory negotiation parameter in RDCLP (i.e. indicating that the memory cannot be estimated) when not present in CDCL is not prohibited. Therefore, reception of such RDCLP in response to CDCL is not to be regarded as an error. + +**3.4.5.4** The RDCLP response may be used to negotiate the value of the inactivity timer. The value of the inactivity timer that the sender of this response wishes to use is indicated in a parameter field of this response. + +**3.4.5.5** The RDCLP response may be used to convey the session user data of the presentation and/or application protocol(s). All information necessary to negotiate the document interchange protocol parameters defined in the T.400 – Series Recommendations is contained in this parameter field. + +**3.4.5.6** The RDCLP response may be used to ascertain compatibility regarding the use of the non-standardized and private use capabilities. + +### **3.4.6 Command document end (CDE)** + +**3.4.6.1** The CDE shall be used to indicate to the receiver of this command the end of a document. It also represents the final checkpoint to which a response shall be made. + +**3.4.6.2** The command parameter is the checkpoint reference number. + +**3.4.6.3** The RDPBN shall be used as the negative response to the checkpoint in CDE. + +### **3.4.7 Response document end positive (RDEP)** + +**3.4.7.1** The RDEP gives a positive acknowledgement to the last checkpoint. In the basic services, this is the last page reference number. + +**3.4.7.2** The RDEP shall also indicate that the receiver: + +- a) has not detected any error; +- b) accepts responsibility for the received document; and +- c) is ready to receive a new CDS or CDC. + +**3.4.7.3** The RDEP shall include as a parameter the checkpoint reference number of the CDE. + +**3.4.7.4** Only if the sink terminal has sent an RDEP and received either a valid CDS, CDC, CDCL, CSE or CSCC, is it certain that the source terminal will not use error recovery procedures regarding the preceding document. In all other cases it can happen that after sending RDEP a repetition of pages takes place and the duplications may be deleted by the sink terminal. + +### **3.4.8 Command document discard (CDD)** + +**3.4.8.1** The CDD shall be used to indicate to the receiver of this command the abnormal ending of a document and that the receiver of the command is not held responsible for the part of the document received so far. Therefore, as a local function outside these control procedures, the receiver can delete the part of the text received. + +#### NOTES + +1 CDD is an invitation to discard the whole of the document and not merely the part of the document transmitted since the last CDC. + +2 The receiving terminal may discard the document from its memory and/or indicate to the operator that his part of the document has no value. + +3 The implementation of this function for Group 4 facsimile is for further study. + +**3.4.8.2** The reason for sending the CDD command may be given as a CDD parameter. If used, only one of the following reasons shall be indicated: + +- a) unable to continue a session (e.g. due to memory full, out of recording paper); +- b) sequence error; +- c) local terminal error; +- d) unrecoverable procedural error; +- e) no specific reason stated (used for reasons other than those listed). + +**3.4.8.3** The CDD may only be used to terminate the current document, instead of using CDE or CDR. It cannot be used after a CDR has been sent (see 4.3.2). + +**3.4.8.4** The receiver of a CDD is allowed to delete the received part of the document, but has no obligation to do so. If the text is not deleted, the operator shall be informed. + +**3.4.8.5** No negative response to CDD is allowed except for error conditions where RDGR applies. + +### **3.4.9 Response document discard positive (RDDP)** + +**3.4.9.1** The RDDP acknowledges the CDD and indicates that the receiver of the command is ready to receive a new CDS or CDC. + +### **3.4.10 Command document resynchronize (CDR)** + +**3.4.10.1** The CDR shall be used by the source to indicate to the sink the point of resynchronization. If used within a document it shall abnormally end that document. + +**3.4.10.2** The reason for an abnormal ending of a document may be given as a CDR parameter. If used, only one of the following reasons may be given: + +- a) unable to continue a session (e.g. due to memory full, out of recording paper); +- b) sequence error; +- c) local terminal error; +- d) unrecoverable procedural error; +- e) no specific reason stated (used for reasons other than those listed). + +**3.4.10.3** No negative response to CDR is allowed except for error conditions where RDGR applies. + +### **3.4.11 Response document resynchronize positive (RDRP)** + +**3.4.11.1** The RDRP is sent by the receiver of a CDR as a positive acknowledgement of the command. + +**3.4.11.2** If RDRP is used within a document, it confirms to the sender of a CDR that the sender of RDRP has already accepted responsibility for the received document (up to the last checkpoint for which a positive acknowledgement has been sent). It does not indicate that the sender of RDRP will be able to perform linking of the following parts of the interrupted document. + +**3.4.11.3** The control procedures provide a means for resuming transmission of an interrupted document. + +**3.4.11.4** The linking of the parts of an interrupted document is a local operation at the receiver and is therefore not within the responsibility of the control procedures. Thus these procedures cannot guarantee that this linking of parts of a document will be effected. + +### **3.4.12 Command document user information (CDUI)** + +**3.4.12.1** The CDUI indicates to the receiver of this command that the associated information is to be interpreted as the user text information field being conveyed. + +**3.4.12.2** The basic services do not require any parameter for CDUI. The procedure provides means for adding parameters. Any such need is for further study. For the basic services a CDUI has to contain a user information field. The need for having CDUIs without information field is for further study. + +**3.4.12.3** Several CDUIs may be used to transfer the contents of one page. + +### **3.4.13 Command document page boundary (CDPB)** + +**3.4.13.1** The CDPB indicates to the receiver the boundary between pages. It also indicates a checkpoint for error recovery purposes (see clause 4). CDPB invites the sink to accept responsibility for the previously received page. + +**3.4.13.2** The CDPB command parameter is the checkpoint reference number, which, in the basic services, is the page reference number. + +**3.4.13.3** The checkpoint reference number appearing in the first CDPB after a CDC is the one appearing in this CDC plus one. + +### **3.4.14 Response document page boundary positive (RDPBP)** + +**3.4.14.1** This response shall be used to indicate that the receiver accepts responsibility for that page. + +**3.4.14.2** Response parameters are: + +- a) a mandatory parameter giving the checkpoint reference number (see 3.4.13.2 above); +- b) a mandatory parameter indicating whether or not the ability of the receiving terminal to continue to accept traffic is jeopardized (e.g. whether or not the memory threshold has been reached). + +### **3.4.15 Response document page boundary negative (RDPBN)** + +**3.4.15.1** This response shall be used to indicate that the receiver does not accept the responsibility for that page for example, due to a detected error or other failure. + +NOTE – This response may also be returned at any point within the document boundary after the receipt of CDS. + +**3.4.15.2** The value of the mandatory parameter giving the reason for a negative response should be one of the following: + +- a) unable to continue a session (e.g. due to memory full, out of recording paper); +- b) sequence error; +- c) local terminal error; +- d) unrecoverable procedural error; +- e) no specific reason stated (used for reasons other than those listed). + +## **3.5 General rules for document elements of procedure** + +**3.5.1** When a document has been either started by CDS or continued by CDC, it must be terminated by either CDE, CDR or CDD prior to sending the next CDS or CDC. + +**3.5.2** The following rules relate to the CDS and CDC parameters: + +- a) the service interworking parameter may be used to indicate that the document is suitable for interworking; however, use of this parameter is mandatory in the case of service interworking; +- b) absence of the document type identifier indicates that the associated document is a normal document. + +**3.5.3** No negative response to CDS or CDC may be sent after the sending of a positive response to any checkpoint within that document. No negative response may be sent to any document commands once the checkpoint associated with those commands has been positively acknowledged. + +**3.5.4** With regard to the responses to CDPB (RDPBP or RDPBN), the receiver may reject reception for a detected error, but the receiver is not obligated to monitor for errors in the document. Once a page has been positively acknowledged, any error recovery for the subsequent detection of an error is beyond the scope of these control procedures. + +**3.5.5** If, during the transmission of a document, there is an interruption of the transport connection or session such that another call and/or session establishment is needed, the following rules apply: + +- a) In the case that a document transmission is initiated by a CDS and no checkpoint is positively acknowledged during that document transmission: + - the receiving terminal shall treat the failure as if a CDD had been received and an RDDP had been sent; + - the sending terminal shall treat the failure as if a CDD had been sent and an RDDP had been received. +- b) In other cases: + - the receiving terminal shall treat the failure as if a CDR had been received and an RDRP had been sent; + - the sending terminal shall treat the failure as if a CDR had been sent and an RDRP had been received. + +**3.5.6** If, during the transmission of a document, an abnormal condition except those described in 3.5.5 takes place, the following rules apply: + +- a) in the case that a document transmission is initiated by CDS command and no checkpoint is positively acknowledged, either a CDD or a CDR command should be used. If a CDR is used, it should be interpreted as a CDD; +- b) in other cases, a CDD or CDR should be used. + +**3.5.7** When a source terminal receives an RDPBP with the receiving ability jeopardized (RAJ) parameter set to 1 during a document transmission, it may continue to transmit one or more pages until the window is closed. In this context the following rules apply: + +- a) if the source subsequently receives an RDPBP with the RAJ parameter set to 0, it will be able to continue transmission; +- b) if the source subsequently receives an RDPBN indicating “memory overflow”, the document transmission should be terminated abnormally; e.g. exchange of either CDD/RDDP or CDR/RDRP. + +*NOTE – In other contexts (e.g. window size of 1), the session may be terminated abnormally due to expiration of an inactivity timer. However, this requires further study.* + +**3.5.8** When a sink terminal sends an RDPBP with the receiving ability jeopardized parameter set to 1, and subsequent memory overflow results in sending RDPBN, the reason code “unable to continue the session” has to be indicated. + +## **3.6 Rules for document state diagrams** + +### **3.6.1 General** + +**3.6.1.1** The rules common to all state diagrams are given in Annex D. + +**3.6.1.2** For any error a terminal is permitted to send CSA. If this procedure is not used, the following rules shall apply. + +### **3.6.2 Rules for the sending protocol (see Figure 2)** + +**3.6.2.1** Any command or response received in state 1 shall cause an abnormal end of the session and sending of CSA. + +**3.6.2.2** Reception of any command or response not shown as allowed in the state diagram in states 2 to 11 shall cause CDR or CDD to be sent in accordance with 3.5.6. + +**3.6.2.3** Reception of any command or response except RDCLP in state 14 shall cause CDR to be sent. + +**3.6.2.4** In state 13 receipt of RDRP or RDDP will cause a transition to state 1. Any other command or response will be discarded. + +**3.6.2.5** The demand response timer started when state 13 is entered is only reset when a valid response is received. + +### **3.6.3 Rules for the receiving protocol (see Figure 3)** + +**3.6.3.1** Reception of any command or response except CDS, CDC, CDCL, CDR or CDD in state 1 shall cause RDGR to be sent. + +**3.6.3.2** In state 12 receipt of CDR or CDD will cause a transition to state 13. Any other command or response received will be discarded. + +**3.6.3.3** Reception of any command or response not allowed in the state diagram or any invalid parameters or parameter values in state 2 to 11 may cause RDGR to be sent. + +**3.6.3.4** The inactivity timer started when state 12 is entered is only reset when a valid command is received. + +![Document state transition diagram for a window size of 3 (sending protocol). The diagram shows 15 states (0-14) and their transitions. State 0 is 'Idle'. State 1 is 'Send (outside document)'. States 2, 4, and 6 represent 'Checkpoint outstanding' counts of 0, 1, and 2. States 3, 5, and 7 are 'Page' states. States 8, 13, and 14 are 'Demand response' states. States 9, 10, and 11 are 'End document' states. State 12 is 'Error'. Transitions are triggered by sending (S-) or receiving (R-) specific protocol commands like CDCL, RDCLP, CDS, CDC, CDUI, CDPB, CDE, RDPBP, RDEP, CDR, CDD, RDRP, RDDP, RDPBN, and RDGR.](5b8a756d9a71c35f17db8bcb90b438a3_img.jpg) + +``` + +stateDiagram-v2 + [*] --> 0 : Reset + [*] --> 1 : Set when in session sending state + state 0 as "0 +Idle" + state 1 as "1 +Send (outside document)" + state 2 as "2 +Checkpoint +outstanding = 0" + state 3 as "3 +Page" + state 4 as "4 +Checkpoint +outstanding = 1" + state 5 as "5 +Page" + state 6 as "6 +Checkpoint +outstanding = 2" + state 7 as "7 +Page" + state 8 as "8 +Demand +response" + state 9 as "9 +End +document" + state 10 as "10 +End +document" + state 11 as "11 +End +document" + state 12 as "12 +Error" + state 13 as "13 +Demand +response" + state 14 as "14 +Demand +response" + + 0 --> 1 : S-CDCL + 1 --> 14 : S-CDCL + 14 --> 1 : R-RDCLP + 1 --> 2 : S-CDS or CDC + 2 --> 3 : S-CDUI + 3 --> 3 : S-CDUI + 3 --> 4 : S-CDPB + 3 --> 9 : S-CDE + 4 --> 2 : R-RDPBP + 4 --> 5 : S-CDUI + 5 --> 5 : S-CDUI + 5 --> 6 : S-CDPB + 5 --> 10 : S-CDE + 6 --> 4 : R-RDPBP + 6 --> 7 : S-CDUI + 7 --> 7 : S-CDUI + 7 --> 8 : S-CDPB + 7 --> 11 : S-CDE + 8 --> 6 : R-RDPBP + 9 --> 1 : R-RDEP + 10 --> 9 : R-RDPBP + 11 --> 10 : R-RDPBP + 12 --> 13 : S-CDR or CDD + 13 --> 1 : R-RDRP or RDDP + [*] --> 12 : R-RDPBN ou RDGR (Receiver error) + [*] --> 13 : S-CDR ou CDD (Sender error) + +``` + +In the case of errors detected at the receiver's side: +R-RDPBN ou RDGR + +In the case of errors detected at the sender's side: +S-CDR or CDD + +In the case of errors detected at the sender's side: +S-CDR ou CDD + +Document state transition diagram for a window size of 3 (sending protocol). The diagram shows 15 states (0-14) and their transitions. State 0 is 'Idle'. State 1 is 'Send (outside document)'. States 2, 4, and 6 represent 'Checkpoint outstanding' counts of 0, 1, and 2. States 3, 5, and 7 are 'Page' states. States 8, 13, and 14 are 'Demand response' states. States 9, 10, and 11 are 'End document' states. State 12 is 'Error'. Transitions are triggered by sending (S-) or receiving (R-) specific protocol commands like CDCL, RDCLP, CDS, CDC, CDUI, CDPB, CDE, RDPBP, RDEP, CDR, CDD, RDRP, RDDP, RDPBN, and RDGR. + +T0817390-94/d02 + +FIGURE 2/T.62 +**Document state transition diagram for a window size of 3 +(sending protocol)** + +![Document state transition diagram for a window size of 3 (receiving protocol). The diagram shows 15 states: 0 Idle, 1 Receiving (out-side document), 2 Checkpoint outstanding = 0, 3 Page, 4 Checkpoint outstanding = 1, 5 Page, 6 Checkpoint outstanding = 2, 7 Page, 8 Checkpoint outstanding = 3, 9 End document, 10 End document, 11 End document, 12 Error, 13 Abnormal end, and 14 Response pending. Transitions are labeled with protocol events like R-CDCL, S-RDCLP, R-CDS or CDC, S-RDEP, R-CDUI, R-CDPB, S-RDPBP, R-CDE, S-RDPBN or RDGR, R-CDR or CDD, and S-RDRP or RDDP. A 'Reset' arrow points to state 0, and a note 'Set when in session receiving state' points to the transition from 0 to 1. Error handling paths lead from states 2, 4, 6, 8 to state 12, and from state 12 to state 13. Transitions from 14 and 13 lead back to state 1.](e69b9188aa2c14ec6b21c83f711fef65_img.jpg) + +``` + +stateDiagram-v2 + state 0 as "0 +Idle" + state 1 as "1 +Receiving (out-side +document)" + state 2 as "2 +Checkpoint +outstanding = 0" + state 3 as "3 +Page" + state 4 as "4 +Checkpoint +outstanding = 1" + state 5 as "5 +Page" + state 6 as "6 +Checkpoint +outstanding = 2" + state 7 as "7 +Page" + state 8 as "8 +Checkpoint +outstanding = 3" + state 9 as "9 +End +document" + state 10 as "10 +End +document" + state 11 as "11 +End +document" + state 12 as "12 +Error" + state 13 as "13 +Abnormal +end" + state 14 as "14 +Response +pending" + + [*] --> 0 : Reset + 0 --> 1 : Set when in session +receiving state + 1 --> 14 : R-CDCL + 14 --> 1 : S-RDCLP + 1 --> 2 : R-CDS or CDC + 2 --> 3 : R-CDUI + 3 --> 3 : R-CDUI + 3 --> 4 : R-CDPB + 4 --> 3 : S-RDPBP + 3 --> 9 : R-CDE + 9 --> 1 : S-RDEP + 4 --> 5 : S-RDPBP + 5 --> 5 : R-CDUI + 5 --> 4 : R-CDUI + 5 --> 6 : R-CDPB + 6 --> 5 : S-RDPBP + 5 --> 10 : R-CDE + 10 --> 9 : S-RDPBP + 6 --> 7 : S-RDPBP + 7 --> 7 : S-CDUI + 7 --> 6 : R-CDUI + 7 --> 8 : R-CDPB + 8 --> 7 : R-CDPB + 7 --> 11 : R-CDE + 11 --> 10 : S-RDPBP + 2 --> 12 : S-RDPBN or RDGR + 4 --> 12 : S-RDPBN or RDGR + 6 --> 12 : S-RDPBN or RDGR + 8 --> 12 : S-RDPBN or RDGR + 12 --> 13 : R-CDR or CDD + 13 --> 1 : S-RDRP or RDDP + [*] --> 13 : R-CDR or CDD + +``` + +Reset + +Set when in session receiving state + +0 Idle + +1 Receiving (out-side document) + +2 Checkpoint outstanding = 0 + +3 Page + +4 Checkpoint outstanding = 1 + +5 Page + +6 Checkpoint outstanding = 2 + +7 Page + +8 Checkpoint outstanding = 3 + +9 End document + +10 End document + +11 End document + +12 Error + +13 Abnormal end + +14 Response pending + +R-CDCL + +S-RDCLP + +R-CDS or CDC + +S-RDEP + +R-CDUI + +R-CDPB + +S-RDPBP + +R-CDE + +S-RDPBN or RDGR + +R-CDR or CDD + +S-RDRP or RDDP + +In the case of error detected at the receiver's side + +In the case of errors detected at the sender's side + +Document state transition diagram for a window size of 3 (receiving protocol). The diagram shows 15 states: 0 Idle, 1 Receiving (out-side document), 2 Checkpoint outstanding = 0, 3 Page, 4 Checkpoint outstanding = 1, 5 Page, 6 Checkpoint outstanding = 2, 7 Page, 8 Checkpoint outstanding = 3, 9 End document, 10 End document, 11 End document, 12 Error, 13 Abnormal end, and 14 Response pending. Transitions are labeled with protocol events like R-CDCL, S-RDCLP, R-CDS or CDC, S-RDEP, R-CDUI, R-CDPB, S-RDPBP, R-CDE, S-RDPBN or RDGR, R-CDR or CDD, and S-RDRP or RDDP. A 'Reset' arrow points to state 0, and a note 'Set when in session receiving state' points to the transition from 0 to 1. Error handling paths lead from states 2, 4, 6, 8 to state 12, and from state 12 to state 13. Transitions from 14 and 13 lead back to state 1. + +T0817400-94/d03 + +FIGURE 3/T.62 +**Document state transition diagram +for a window size of 3 (receiving protocol)** + +# **4 Error recovery** + +## **4.1 General principles** + +**4.1.1** During a session, each partner is responsible for monitoring for the correct operation of the following: + +- a) maintenance of the currently agreed source/sink relationship; +- b) proper use of the command/response procedural sequences as described in the state diagrams and rules for operation (see 3.6); +- c) detection of any period of inactivity in excess of the inactivity timer value as determined by negotiation (indicating, for example, a failure or other inability to continue productive use of the session); +- d) detection of a period of time in excess of the demand response timer value in which the remote terminal has failed to issue a response. + +NOTE – Negotiation of the demand response timer value is for further study. + +**4.1.2** The following rules apply to the negotiation of the value of the inactivity timer; + +- a) an inactivity timer value different from 60 seconds will apply only if this parameter is indicated by both terminals, i.e. negotiation, at session establishment (via CSS/RSSP) or document boundaries (via CDCL/RDCLP); +- b) if both terminals indicate an inactivity timer value the following rules apply for the duration of the session or until a subsequent negotiation has taken place: + - i) The smaller of the two values applies when both values are greater than or equal to 60 seconds. + - ii) The larger of the two values applies when both values are less than 60 seconds. + - iii) A timer value of 60 seconds applies if one value is above and one is below 60 seconds. + +**4.1.3** Upon detection of any failure to maintain proper operation as described in 4.1.1, use of the error recovery procedures defined for each state is mandatory; or, where such error recovery procedures are not specifically defined, session termination (abnormal end) is mandatory. In the event of an error, this control procedure allows for repeated transmission of information. The number of repetitions should be limited by the sender and may be zero. + +## **4.2 Rules for checkpointing** + +**4.2.1** After an abnormal termination of a document, for recovery in the same session the checkpoint reference number and the document reference number are required in order to identify unambiguously the point from which to recover. + +**4.2.2** A new session (and call) has to be initiated after abnormal termination of a document where recovery is to be effected in a subsequent session or after an abnormal termination and/or interruption of the call. The information required in order to identify unambiguously the point from which to recover is: + +- a) the reference for the interrupted session; +- b) the document reference number; and +- c) the checkpoint reference number. + +**4.2.3** In the basic services a checkpoint must be inserted at each page boundary using CDPB. + +**4.2.4** If a negative response is received to a command representing a checkpoint, the transmission must be interrupted by sending a CDR or CDD. + +**4.2.5** Within a document, a final checkpoint will be represented by the CDE. Transmission of another document is not permitted until the response to this command has been received. + +**4.2.6** No other checkpointing is permitted in the basic service. + +**4.2.7** Each command representing a checkpoint shall contain a parameter showing the reference number. Each such command calls for a response, which shall contain a parameter showing the checkpoint reference number to which that response applies. Each checkpoint in the CDPB must be explicitly acknowledged and the acknowledgements must be in the right sequence. + +**4.2.8** Checkpoint reference numbers shall be assigned as decimal digits starting from 001 and sequentially incremented by one for each checkpoint within a document. The number does not necessarily have to comprise 3 digits and leading zeros do not necessarily have to be transmitted. In all cases, the leading zeroes must be ignored. + +**4.2.9** Document reference numbers (DRNs) shall be assigned as decimal digits, preferably, but not necessarily, starting from 001. DRNs shall then sequentially be incremented by one for each successive document. DRNs shall be assigned to all documents in a session, irrespective of the document type identifier or whether CDS or CDC is used as the initiating command. The number does not necessarily have to comprise 3 digits and leading zeros do not necessarily have to be transmitted. In all cases, the leading zeroes must be ignored. + +NOTE – In order to uniquely identify the documents exchanged, it is recommended that the same DRNs should not appear within a session. However, it is noted that some existing terminals may cause duplication of DRNs when documents are exchanged in both directions. + +**4.2.10** The sum of the numbers of digits contained in the checkpoint reference number and the document reference number shall not exceed six, to permit printing in the available space in the call identification line as defined in Recommendation F.200. There is no constraint on the maximum number of digits in either number, as long as this limitation is not exceeded. + +## **4.3 Acknowledgement window** + +**4.3.1** In the basic Teletex service the sender is prohibited from exceeding an acknowledgement window size of three. The maximum window size may be negotiated during session establishment using the parameters of the CSS command and the corresponding response (see 5.7.2.6). + +**4.3.2** In the Group 4 facsimile service, indication of window size parameters in both CSS command and the corresponding response is required (see 3.3.2.7 and 5.7.2.6). + +**4.3.3** There are two ways that the sender is permitted to recover from an interrupted transmission: + +- a) a cancellation is achieved by the subsequent use of CDC and CDD commands and the transmission will be resumed by the CDS command; +- b) the sender may resume by use of CDC command, starting at the point in the text of the last checkpoint for which an acknowledging response was received. + +On this basis, the receiver must be able to resume reception at a checkpoint ranging from the last acknowledged checkpoint to the last acknowledged checkpoint plus one, minus the window size. + +**4.3.4** The window mechanism has been introduced in order to allow continuous transmission of pages. The window mechanism may also be used by the receiving terminal to resolve local time problems without affecting the continuous transmission. + +NOTE – For efficiency reasons, the receiving terminal will transmit the response to acknowledge outstanding checkpoint(s) as soon as possible. + +**4.3.5** The design of a terminal should be such that continuous reception is possible in normal operation of the terminal (e.g. with an average Teletex page content of 1600 octets). The use of the window mechanism should take into account the quality of service requirements in Recommendations F.200 and F.184. + +**4.3.6** If transmission flow control is needed, it shall be provided by the transport service. + +# **5 Coding** + +## **5.1 Definition of terms used in coding** + +### **5.1.1 command identifier (CI) or response identifier (RI)** + +*F: identificateur de commande (CI) ou de réponse (RI)* + +*S: identificador de instrucción (CI) o identificador de respuesta (RI)* + +The heading information that identifies the command or response concerned. + +### **5.1.2 length indicator (LI)** + +*F: indicateur de longueur (LI)* + +*S: indicador de longitud (LI)* + +Represents the length in octets of an associated field or group of fields. + +### **5.1.3 parameter identifier (PI)** + +*F: identificateur de paramètre (PI)* + +*S: identificador de parámetro (PI)* + +Indicates the type of information contained in an associated field or group of fields. + +### **5.1.4 parameter group identifier (PGI)** + +*F: identificateur de groupe de paramètres (PGI)* + +*S: identificador de grupo de parámetros (PGI)* + +A special case of a parameter identifier, which indicates that the associated field consists entirely of a group of parameters, each identified by a parameter identifier. + +### **5.1.5 parameter value (PV)** + +*F: valeur de paramètre (PV)* + +*S: valor de parámetro (PV)* + +The information that represents the value of the parameter identified by either a PI or PGI. + +### **5.1.6 field** + +*F: champ; domaine* + +*S: campo* + +Either a group of one or more bits within a single octet or a group of one or more octets, used to represent a particular set of information. + +## **5.2 Principles of coding** + +**5.2.1** The coding of session commands, responses and parameters is independent of the coding of document commands, responses and parameters and vice versa. + +**5.2.2** Binary field encoding principles have been used to allocate bit patterns for the CI, RI, PGI and PI. + +**5.2.3** The first section of a session or document field consists of either a CI or an RI. Each CI or RI is always immediately followed by an LI. + +**5.2.4** Bits of an octet are numbered 8 to 1 where bit 1 is the low order bit and is transmitted first. Octets of a session or document field are consecutively numbered starting from 1 and transmitted in this order. + +**5.2.5** The value of an LI is a binary number that represents the total length of the immediately following parameter field(s) in octets. The value of the LI does not include either itself or any subsequent user information. + +**5.2.6** If a parameter field indicated by a PGI appears within a parameter field initiated by a PGI, the PV field of the nested PGI field may not extend beyond the end of the PV of the enclosing PGI field. + +**5.2.7** To decode CI, RI, PGI and PI, all the bits of the identifier must be considered. + +**5.2.8** The format of a parameter field initiated by a PGI is the same as the format of such a field initiated by a PI except that the entire PV field consists of a sequence of one or more parameter fields, each of which is initiated by either PI or PGI. + +**5.2.9** The absence of non-mandatory PI or PGI indicates that no such functions are available. Therefore PIs or PGIs with LI set to zero should be avoided. + +**5.2.10** Figures 4, 5 and 6 illustrate the coding principles. + +![Diagram illustrating the relationship between session and document commands/responses. It shows nested fields: Text, Document (with CI, LI, Parameter field, and User information field), and Session (with CI, LI, Parameter field, and User information field). Arrows indicate the sequence of commands and responses at each level.](e821c3d8a87ee2a9ff6b8644ffe6bdae_img.jpg) + +| | | | | | | | | | +|---------------------------------------------------------------|----------------------|----------------------------------|------------------------------------------|--------|----------------------|----------------------------------|-----------------------------------------|----------| +| | | | | Text | | | | | +| | | | | C<br>I | L<br>I <sup>c)</sup> | Parameter<br>field <sup>a)</sup> | User information<br>field <sup>b)</sup> | Document | +| C<br>I | L<br>I <sup>c)</sup> | Parameter<br>field <sup>a)</sup> | User information field <sup>b), d)</sup> | | | | | Session | +| ← Session field (delivered to the transport service) (TSDU) → | | | | | | | | | +| ← Session command (or response) → | | | | | | | | | +| | | | ← Document field → | | | | | | +| | | | ← Document command (or response) → | | | | | | + +Diagram illustrating the relationship between session and document commands/responses. It shows nested fields: Text, Document (with CI, LI, Parameter field, and User information field), and Session (with CI, LI, Parameter field, and User information field). Arrows indicate the sequence of commands and responses at each level. + +T0817410-94/d04 + +TSDU Transport service data unit + +<sup>a)</sup> Present only if LI ≠ 0. + +<sup>b)</sup> Present only after user information commands (or responses) + +<sup>c)</sup> See 5.2.5. + +<sup>d)</sup> See 1.2.1. + +FIGURE 4/T.62 +**Illustration of the relationship between session +and document commands/responses** + +![Figure 5/T.62: Examples of command/response structure. The figure shows six diagrams (a-f) illustrating different command/response structures. Each diagram consists of a sequence of fields: C (Command), I (Information), L (Length), P (Parameter), L (Length), P (Parameter), L (Length), and V (Value). Arrows indicate the nesting and flow of the structure. a) LI = 0 (i.e. no parameter field). b) LI = 3 and 1 respectively means one parameter of one octet value. c) Two parameters of 1 and 3 octets respectively – LI's are 8, 1 and 3 respectively. d) One PGI with two enclosed PIs. e) The most simple carrier of user information. f) Example of complex use of PGIs.](aaf3e6e44cdeabd6d1df869c5f392ea1_img.jpg) + +a) LI = 0 (i. e. no parameter field) + +b) LI = 3 and 1 respectively means one parameter of one octet value + +c) Two parameters of 1 and 3 octets respectively – LI's are 8, 1 and 3 respectively + +d) One PGI with two enclosed PIs + +e) The most simple carrier of user information + +f) Example of complex use of PGIs + +Figure 5/T.62: Examples of command/response structure. The figure shows six diagrams (a-f) illustrating different command/response structures. Each diagram consists of a sequence of fields: C (Command), I (Information), L (Length), P (Parameter), L (Length), P (Parameter), L (Length), and V (Value). Arrows indicate the nesting and flow of the structure. a) LI = 0 (i.e. no parameter field). b) LI = 3 and 1 respectively means one parameter of one octet value. c) Two parameters of 1 and 3 octets respectively – LI's are 8, 1 and 3 respectively. d) One PGI with two enclosed PIs. e) The most simple carrier of user information. f) Example of complex use of PGIs. + +T0817420-94/d05 + +#### NOTES + +- 1 In every case the CI can be replaced by an RI. +- 2 Any PI or PGI may be omitted when it is not used for conveying information (i.e. paramater values). PIs and PGIs within the same nesting level are put in order of increasing binary value. + +FIGURE 5/T.62 +**Examples of command/response structure** + +![Two flowcharts illustrating allowable sequences of units within a command or response. The left flowchart starts with 'Command/response' (oval), leading to 'CI or RI' (rectangle), then 'LI' (rectangle). From 'LI', a vertical line descends with two branches: one to 'Parameter field' (rectangle) and another to 'User information field' (rectangle), both of which merge back into the vertical line. The right flowchart starts with 'Parameter field' (oval), leading to a split into two parallel paths. The left path consists of 'PI' (rectangle) leading to 'LI' (rectangle) leading to 'PV' (rectangle). The right path consists of 'PGI' (rectangle) leading to 'LI' (rectangle) leading to 'Parameter field' (rectangle). Both paths merge into a single vertical line that ends with an arrow pointing down.](8c348bf9c2c81b018017ae1d19506a9a_img.jpg) + +``` + +graph TD + subgraph Left_Flowchart + CR([Command/response]) --> CIRI[CI or RI] + CIRI --> LI1[LI] + LI1 --> PF1[Parameter field] + LI1 --> UIF[User information field] + PF1 --> Out1[ ] + UIF --> Out1 + Out1 --> Exit1[ ] + end + subgraph Right_Flowchart + PF2([Parameter field]) --> PI[PI] + PF2 --> PGI[PGI] + PI --> LI2[LI] + LI2 --> PV[PV] + PGI --> LI3[LI] + LI3 --> PF3[Parameter field] + PV --> Out2[ ] + PF3 --> Out2 + Out2 --> Exit2[ ] + end + +``` + +Two flowcharts illustrating allowable sequences of units within a command or response. The left flowchart starts with 'Command/response' (oval), leading to 'CI or RI' (rectangle), then 'LI' (rectangle). From 'LI', a vertical line descends with two branches: one to 'Parameter field' (rectangle) and another to 'User information field' (rectangle), both of which merge back into the vertical line. The right flowchart starts with 'Parameter field' (oval), leading to a split into two parallel paths. The left path consists of 'PI' (rectangle) leading to 'LI' (rectangle) leading to 'PV' (rectangle). The right path consists of 'PGI' (rectangle) leading to 'LI' (rectangle) leading to 'Parameter field' (rectangle). Both paths merge into a single vertical line that ends with an arrow pointing down. + +T0817430-94/d06 + +NOTE – This figure may need further study. + +FIGURE 6/T.62 +Allowable sequences of units within a command or response + +## 5.3 Coding of length indicators + +**5.3.1** The value of an LI is a binary number that represents the total length in octets of the immediately following CI, RI, PI and/or PGI fields. The value of the LI does not include either itself or any subsequent user information, as noted in 5.2.5 above. + +**5.3.2** The basic LI consists of a single octet with a maximum value of 254 in decimal (i.e. a binary value of 11111110). + +**5.3.3** If the first octet of the LI is 255 decimal (i.e. a binary value of 11111111), this indicates that the value of the LI is contained in the next two following octets allowing a maximum value of 65 535 octets. + +**5.3.4** Within any octet, the highest order bit is bit 8 with the remaining bits assigned in descending order. Where the length value is represented in two octets, the first contains the higher order bits. + +## **5.4 Coding of command and response identifiers for session elements** + +5.4.1 The coding of CI and RI for session commands and responses is shown in Table 4. + +5.4.2 Apart from private use, the codes of the commands and responses in Table 4 are assigned in such a way that the bits may be interpreted as follows: + +| | | | +|--------------|------------------------------------------------------------------|------------------------------| +| Bit 1 | 1 = Command | 0 = Response | +| Bit 2 | 1 = Positive | 0 = Negative (for responses) | +| Bit 3 | 1 = Initiate | 0 = Stop (for most commands) | +| Bits 4, 5 | 11 Session | | +| | 10 Session | | +| | 01 Interaction | | +| | 00 Session user | | +| Bits 6, 7, 8 | Set to zero (except for private use) and reserved for extension. | | + +NOTE – If possible, this binary field coding structure should be followed in making future code assignments, but this is not mandatory if the number of available code combinations is insufficient. Therefore, it is not intended as a guide for implementation. + +5.4.3 One or more of the non-allocated values are to be reserved for future extension. The method of future extension is for further study. + +## **5.5 Coding of command and response identifiers for document elements** + +5.5.1 The coding of command and response identifiers for document commands and responses is shown in Tables 5 and 6 respectively. + +5.5.2 Apart from private use, the codes of the commands and responses in Tables 5 and 6 are assigned in such a way that the bits may be interpreted as follows: + +| | | | +|--------------|-------------------------------------------------|------------------------------| +| Bit 1 | 1 = Command | 0 = Response | +| Bit 2 | 1 = Positive | 0 = Negative (for responses) | +| Bit 3 | 1 = Initiate | 0 = Stop (for most commands) | +| Bits 4, 5, 6 | 111, 110, 101 | Document | +| | 100 | Reserved | +| | 011 | Page | +| | 010 | Reserved | +| | 001 | Reserved for recovery unit | +| | 000 | Text | +| Bits 7, 8 | Set to zero, and reserved for future extension. | | + +5.5.3 With regard to future extension, see the note in 5.4.2 and, 5.4.3 above. + +## **5.6 Coding of parameter group identifiers and parameter identifiers** + +5.6.1 The coding of PGIs and PIs for session commands and responses is shown in Table 7. The coding of the PGIs and PIs for document commands and responses is shown in Table 8. + +5.6.2 Tables 9 and 10 list the PGIs and PIs for each command and response for the session and document elements of procedure together with an indication of whether the PGIs and PIs concerned are mandatory or not. + +5.6.3 Where a PI is allocated to a particular PGI this is shown in Table 7 or 8. Some PIs are not allocated to a PGI and are used as required. Some PIs may be used without preceding PGIs as defined in Tables 9 and 10. + +TABLE 4/T.62 + +### **Command and response identifiers for session elements** + +| Command/response | Bit number | | | | | | | | +|--------------------------|------------|---|---|---|---|---|---|---| +| | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| CSS | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 1 | +| CSE | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 1 | +| CSA | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 1 | +| CSCC | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 1 | +| CSUI | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | +| RSSP | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | +| RSSN | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | +| RSEP | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | +| RSAP | 0 | 0 | 0 | 1 | 1 | 0 | 1 | 0 | +| RSCCP | 0 | 0 | 0 | 1 | 0 | 1 | 1 | 0 | +| RSUI | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | +| Reserved for private use | 1 | 1 | 1 | 1 | x | x | x | x | + +TABLE 5/T.62 + +### **Coding for document command identifiers** + +| Command | Bit number | | | | | | | | +|--------------------------|------------|---|---|---|---|---|---|---| +| | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| CDS | 0 | 0 | 1 | 0 | 1 | 1 | 0 | 1 | +| CDC | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | +| CDE | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 1 | +| CDR | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 1 | +| CDD | 0 | 0 | 1 | 1 | 1 | 0 | 0 | 1 | +| CDPB | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 1 | +| CDCL | 0 | 0 | 1 | 1 | 1 | 1 | 0 | 1 | +| CDUI | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | +| Reserved for private use | 1 | 1 | 1 | 1 | x | x | x | x | + +TABLE 6/T.62 + +### **Coding for document response identifiers** + +| Response | Bit number | | | | | | | | +|--------------------------|------------|---|---|---|---|---|---|---| +| | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| RDEP | 0 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | +| RDRP | 0 | 0 | 0 | 1 | 1 | 0 | 1 | 0 | +| RDDP | 0 | 0 | 1 | 1 | 1 | 0 | 1 | 0 | +| RDPBP | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 0 | +| RDPBN | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | +| RDCLP | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | +| RDGR | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | +| Reserved for private use | 1 | 1 | 1 | 1 | x | x | x | x | + +**5.6.4** The codes of these PGIs and PIs are assigned in such a way that the binary field consisting of bits 8, 7 and 6 may be interpreted as follows: + +Bits 876 + +| | | +|-----|--------------------------------------------------------------------------------------------------| +| 000 | Session related | +| 001 | Document related (These document related PGIs and PIs may possibly be of use to other services.) | +| 010 | Document related (for Teletex) | +| 011 | Reserved | +| 100 | | +| 101 | | +| 110 | User data | +| 111 | Private use | + +The binary field consisting of bits 5 and 4 may be interpreted as follows: + +Bits 54 + +| | | +|----|-----| +| 00 | PGI | +| 01 | PI | +| 10 | PI | +| 11 | PI | + +The binary field consisting of bits 3, 2 and 1 is used to extend the PGIs when set to 000. + +NOTE – If possible, this binary field coding structure should be followed in making future code assignments, but this is not mandatory if the number of available code combinations is insufficient. Therefore, it is not intended as a guide for implementation. + +**5.6.5** PGIs and PIs within the same nesting level should be put in the order of increasing binary value. The coding order of PGIs and PIs included in each command or response is defined in Tables 9 and 10. + +**5.6.6** The following rules shall apply to the private use and presently not defined parameters: + +- these parameters, if present in CSS or CDCL (or their corresponding responses), shall not lead to procedural errors; +- the use of these parameters in other commands or responses must be negotiated upon in advance by CSS or CDCL and their corresponding responses (see 3.3.2.3); + +- c) presence of these parameters “unexpectedly” in elements other than CSS, RSSP, CDCL or RDCLP may result in procedural errors; +- d) the absence of a parameter of this kind in a response to CSS or CDCL must be interpreted as an indication that the terminal is not capable of handling any of these functions. + +## **5.7 Parameter values** + +### **5.7.1 General** + +**5.7.1.1** Unless otherwise specified the following rules apply to the fields containing parameter values (PV): + +- a) Where a binary number is used to represent a value, the highest order bit of each octet is bit 8 with the remaining bits assigned in descending order. Where a binary value is represented by more than one octet, the first octet contains the highest order bits, with successive octets assigned in descending order. +- b) All bits reserved for future standardization shall be set to zero. +- c) Where a PV contains graphic characters that may be printed or displayed, they shall be in the intended printing/display sequence and shall be coded as defined in Recommendation T.61. +- d) For a PGI designated for extension, the PIs and/or PGIs included in the parameter field do not necessarily conform to the following assignments of PI and PGI values. + +**5.7.1.2** Assignment of coding to the various parameter values is shown in the following paragraphs. + +### **5.7.2 Session related parameters** + +NOTE – The following paragraphs include either session related or both session and document related parameters. + +#### **5.7.2.1 Terminal identifier of the called terminal** + +A sequence of graphic characters as defined in Recommendation F.200. + +#### **5.7.2.2 Terminal identifier of the calling terminal** + +A sequence of graphic characters as defined in Recommendation F.200. + +#### **5.7.2.3 Date and time** + +A sequence of graphic characters as defined in Recommendation F.200. + +#### **5.7.2.4 Additional session reference number** + +A fixed length sequence of two decimal digits as coded in Recommendation T.61. + +#### **5.7.2.5 Miscellaneous session capabilities** + +Bit 1 of the first octet set to 1 indicates the terminal capability for two-way simultaneous information transfer. + +Bit 2 of the first octet set to 1 indicates the terminal capability for session suspension. + +Bit 3 of the first octet set to 1 indicates the terminal capability for interactive operation. + +All other bit values are reserved for future standardization. + +#### **5.7.2.6 Window size** + +A binary number of fixed length of one octet, with a minimum value of one and a maximum value of 255 in decimal (i.e. a binary value of 11111111). The default value is three in decimal (i.e. a binary value of 00000011). + +TABLE 7/T.62 + +##### Coding of session PGIs and PIs + +| Parameter group identifier (PGI) | | | | | | | | | Parameter identifier (PI) | | | | | | | | | +|-----------------------------------------|------------|---|---|---|---|---|---|---|---------------------------------------------|------------|---|---|---|---|---|---|---| +| Name or function | Bit number | | | | | | | | Name | Bit number | | | | | | | | +| | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| Reserved for extension | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | | | | | | | | | | +| Session reference | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | Terminal identifier of the called terminal | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 1 | +| | | | | | | | | | Terminal identifier of the calling terminal | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | +| | | | | | | | | | Date and time | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 1 | +| | | | | | | | | | Additional session reference number | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | +| Non-basic session capabilities | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | Miscellaneous session capabilities | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 1 | +| | | | | | | | | | Window size | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | +| No PGI associated with these PIs | | | | | | | | | Service identifier | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | +| | | | | | | | | | Session control functions | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | +| | | | | | | | | | Session termination parameter | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 1 | +| | | | | | | | | | Inactivity timer | 0 | 0 | 0 | 1 | 0 | 0 | 1 | 0 | +| | | | | | | | | | Session service functions | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 0 | +| | | | | | | | | | Reason | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 0 | +| Non-basic Teletex terminal capabilities | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | Control character set | 0 | 1 | 0 | 0 | 1 | 0 | 0 | 1 | +| | | | | | | | | | Teletex page format | 0 | 1 | 0 | 0 | 1 | 0 | 1 | 0 | +| | | | | | | | | | Miscellaneous Teletex terminal capabilities | 0 | 1 | 0 | 0 | 1 | 0 | 1 | 1 | +| Session user data | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | | | | | | | | | | +| Private use | 1 | 1 | 1 | 0 | 0 | x | x | x | Private use | 1 | 1 | 1 | 0 | 1 | x | x | x | +| | | | | | | | | | Private use | 1 | 1 | 1 | 1 | 0 | x | x | x | +| | | | | | | | | | Private use | 1 | 1 | 1 | 1 | 1 | x | x | x | +| | | | | | | | | | Non-standardized capabilities | 1 | 1 | 1 | 0 | 1 | 0 | 0 | 0 | + +TABLE 8/T.62 + +##### Coding of document PGIs and PIs + +| Parameter group identifier (PGI) | | | | | | | | Parameter identifier (PI) | | | | | | | | | | +|-----------------------------------------|------------|---|---|---|---|---|---|---------------------------|---------------------------------------------|------------|---|---|---|---|---|---|---| +| Name or function | Bit number | | | | | | | | Name | Bit number | | | | | | | | +| | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| Reserved for extension | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | | | | | | | | | | +| Document linking | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 1 | Terminal identifier of the called terminal | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 1 | +| | | | | | | | | | Terminal identifier of the calling terminal | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | +| | | | | | | | | | Date and time | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 1 | +| | | | | | | | | | Additional session reference number | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | +| | | | | | | | | | Document reference number | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 1 | +| | | | | | | | | | Checkpoint reference number | 0 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | +| No PGI associated with these PIs | | | | | | | | | Inactivity timer | 0 | 0 | 0 | 1 | 0 | 0 | 1 | 0 | +| | | | | | | | | | Service interworking identifier | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | +| | | | | | | | | | Document reference number | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 1 | +| | | | | | | | | | Checkpoint reference number | 0 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | +| | | | | | | | | | Acceptance of CDCL parameters | 0 | 0 | 1 | 0 | 1 | 1 | 0 | 0 | +| | | | | | | | | | Storage capacity negotiation | 0 | 0 | 1 | 0 | 1 | 1 | 0 | 1 | +| | | | | | | | | | Receiving ability jeopardized | 0 | 0 | 1 | 0 | 1 | 1 | 1 | 0 | +| | | | | | | | | | Reserved | 0 | 0 | 1 | 0 | 1 | 1 | 1 | 1 | +| | | | | | | | | | Document type identifier | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | +| | | | | | | | | | Reflect parameter values | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 1 | +| | | | | | | | | | Reason | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 0 | +| Reserved for extension | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | | | | | | | | | | +| Non-basic Teletex terminal capabilities | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | Graphic character set | 0 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | +| | | | | | | | | | Control character set | 0 | 1 | 0 | 0 | 1 | 0 | 0 | 1 | +| | | | | | | | | | Teletex page format | 0 | 1 | 0 | 0 | 1 | 0 | 1 | 0 | +| | | | | | | | | | Miscellaneous Teletex terminal capabilities | 0 | 1 | 0 | 0 | 1 | 0 | 1 | 1 | +| | | | | | | | | | Character box height | 0 | 1 | 0 | 0 | 1 | 1 | 0 | 1 | +| | | | | | | | | | Character box width | 0 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | +| Session user data | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | | | | | | | | | | +| Private use | 1 | 1 | 1 | 0 | 0 | x | x | x | Private use | 1 | 1 | 1 | 0 | 1 | x | x | x | +| | | | | | | | | | Private use | 1 | 1 | 1 | 1 | 0 | x | x | x | +| | | | | | | | | | Private use | 1 | 1 | 1 | 1 | 1 | x | x | x | +| | | | | | | | | | Non-standardized capabilities | 1 | 1 | 1 | 0 | 1 | 0 | 0 | 0 | + +TABLE 9/T.62 + +###### **PGIs and PIs for session elements of procedure** + +| Session command or response identifier | Parameter group identifier (PGI) | | Parameter identifier (PI) | | +|----------------------------------------|-----------------------------------------|----------------------------|---------------------------------------------|----------------------------| +| | Description | Mandatory or not mandatory | Description | Mandatory or not mandatory | +| CSS | Session reference | M | Terminal identifier of the calling terminal | M | +| | | | Date and time | M | +| | | | Additional session reference number | Nm | +| | Non-basic session capabilities | Nm | Miscellaneous session capabilities | Nm | +| | | | Window size (Note) | Nm | +| | | | Service identifier | M | +| | | | Inactivity timer | Nm | +| | | | Session service functions | Nm | +| | Non-basic Teletex terminal capabilities | Nm | Control character sets | Nm | +| | | | Teletex page formats | Nm | +| | | | Miscellaneous Teletex terminal capabilities | Nm | +| | Session user data | Nm | | | +| | Private use | Nm | | | +| | | | Non-standardized capabilities | Nm | +| CSE | | | Session termination parameter | Nm | +| CSA | | | Session termination parameter | M | +| CSCC | | | | | +| CSUI | | | Session control functions | Nm | +| RSSP | Session reference | M | Terminal identifier of the called terminal | M | +| | | | Date and time | M | +| | | | Additional session reference number | Nm | +| | Non-basic session capabilities | Nm | Miscellaneous session capabilities | Nm | +| | | | Window size | Nm | +| | | | Service identifier | M | +| | | | Session control functions | Nm | +| | | | Inactivity timer | Nm | +| | | | Session service functions | Nm | + +TABLE 9/T.62 (end) + +###### PGIs and PIs for session elements of procedure + +| Session command or response identifier | Parameter group identifier (PGI) | | Parameter identifier (PI) | | +|------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------|----------------------------|---------------------------------------------|----------------------------| +| | Description | Mandatory or not mandatory | Description | Mandatory or not mandatory | +| RSSP (cont.) | Non-basic Teletex terminal capabilities | Nm | Control character sets | Nm | +| | | | Teletex page formats | Nm | +| | | | Miscellaneous Teletex terminal capabilities | Nm | +| | Session user data | Nm | | | +| | Private use | Nm | | | +| | | | Non-standardized capabilities | Nm | +| RSSN | Session reference | M | Terminal identifier of the called terminal | M | +| | | | Date and time | M | +| | | | Additional session reference number | Nm | +| | Non-basic session capabilities | Nm | Miscellaneous session capabilities | Nm | +| | | | Window size | Nm | +| | | | Service identifier | M | +| | | | Session service functions | Nm | +| | | | Reason | Nm | +| | Non-basic Teletex terminal capabilities | Nm | Control character sets | Nm | +| | | | Teletex page formats | Nm | +| | | | Miscellaneous Teletex terminal capabilities | Nm | +| | Session user data | Nm | | | +| | Private use | Nm | | | +| RSEP | | | | | +| RSAP | | | | | +| RSCCP | | | | | +| RSUI | | | Session control functions | Nm | +| NOTE - This parameter "window size" in CSS, RSSP and RSSN is mandatory for the Group 4 facsimile service (see 4.3.2), but not mandatory for the Teletex service. | | | | | + +TABLE 10/T.62 + +###### **PGIs and PIs for document elements of procedure** + +| Document command or response identifier | Parameter group identifier (PGI) | | Parameter identifier (PI) | | +|-----------------------------------------|-----------------------------------------|----------------------------|---------------------------------------------|----------------------------| +| | Description | Mandatory or not mandatory | Description | Mandatory or not mandatory | +| CDS | | | Service interworking identifier | Nm | +| | | | Document reference number | M | +| | | | Document type identifier | Nm | +| | Non-basic Teletex terminal capabilities | Nm | Graphic character sets | Nm | +| | | | Control character sets | Nm | +| | | | Teletex page formats | Nm | +| | | | Miscellaneous Teletex terminal capabilities | Nm | +| | | | Character box height | Nm | +| | | | Character box width | Nm | +| | Session user data | Nm | | | +| | Private use | Nm | | | +| CDC | Document linking | M<br><br>(Note) | Terminal identifier of the called terminal | M | +| | | | Terminal identifier of the calling terminal | M | +| | | | Date and time | M | +| | | | Additional session reference number | Nm | +| | | | Document reference number | M | +| | | | Check point reference number | M | +| | | | Service interworking identifier | Nm | +| | | | Document reference number (current session) | M | +| | | | Document type identifier | Nm | +| | Non-basic Teletex terminal capabilities | Nm | Graphic character sets | Nm | +| | | | Control character sets | Nm | +| | | | Teletex page formats | Nm | + +TABLE 10/T.62 (continued) + +###### **PGIs and PIs for document elements of procedure** + +| Document command or response identifier | Parameter group identifier (PGI) | | Parameter identifier (PI) | | +|-----------------------------------------|-----------------------------------------|----------------------------|---------------------------------------------|----------------------------| +| | Description | Mandatory or not mandatory | Description | Mandatory or not mandatory | +| CDC (cont.) | | | Miscellaneous Teletex terminal capabilities | Nm | +| | | | Character box height | Nm | +| | | | Character box width | Nm | +| | Session user data | Nm | | | +| | Private use | Nm | | | +| CDE | | | Checkpoint reference number | M | +| CDR | | | Reason | Nm | +| CDD | | | Reason | Nm | +| CDPB | | | Checkpoint reference number | M | +| CDUI | | | | | +| CDCL | | | Inactivity timer | Nm | +| | | | Storage capacity negotiation | Nm | +| | Non-basic Teletex terminal capabilities | Nm | Graphic character sets | Nm | +| | | | Control character sets | Nm | +| | | | Teletex page formats | Nm | +| | | | Miscellaneous Teletex terminal capabilities | Nm | +| | | | Character box height | Nm | +| | | | Character box width | Nm | +| | Session user data | Nm | | | +| | Private use | Nm | | | +| | | | Non-standardized capabilities | Nm | +| RDEP | | | Checkpoint reference number | M | +| RDRP | | | | | +| RDDP | | | | | +| RDPBP | | | Checkpoint reference number | M | +| | | | Receiving ability jeopardized | M | + +TABLE 10/T.62 (*end*) + +###### **PGIs and PIs for document elements of procedure** + +| Document command or response identifier | Parameter group identifier (PGI) | | Parameter identifier (PI) | | +|------------------------------------------------------------------------------|-----------------------------------------|----------------------------|---------------------------------------------|----------------------------| +| | Description | Mandatory or not mandatory | Description | Mandatory or not mandatory | +| RDPBN | | | Reason | M | +| RDCLP | | | Inactivity timer | Nm | +| | | | Acceptance of CDCL parameters | Nm | +| | | | Storage capacity negotiation | Nm | +| | Non-basic Teletex terminal capabilities | Nm | Graphic character sets | Nm | +| | | | Control character sets | Nm | +| | | | Teletex page formats | Nm | +| | | | Miscellaneous Teletex terminal capabilities | Nm | +| | | | Character box height | Nm | +| | | | Character box width | Nm | +| | Session user data | Nm | | | +| | Private use | Nm | | | +| | | | Non-standardized capabilities | Nm | +| RDGR | | | Reflect parameter values | M | +| NOTE – These PIs are required only if linking is attempted in a new session. | | | | | + +#### **5.7.2.7 Service identifier** + +The coding for the service identifier is as follows: + +| | | +|---------------|-----------| +| Bits 87654321 | Service | +| 00000001 | Telematic | + +All other encodings are for further study. + +#### **5.7.2.8 Session control functions** + +When used with a response, i.e. either RSSP or RSUI, the following bit assignments are defined in the first octet: + +- bit 1 set to 1 indicates request control (as defined in this Recommendation); +- all other bits are reserved for future standardization. + +#### **5.7.2.9 Session termination parameter** + +Bit 1 of the first octet set to 1 indicates that the transport connection shall be cleared (default value). When set to 0 it indicates that the connection should not be cleared. + +Bit 2 of the first octet set to 1 indicates a local terminal error. + +Bit 3 of the first octet set to 1 indicates an unrecoverable procedural error. + +Bit 4 of the first octet set to 1 indicates that no reason is given. + +All other bits are reserved for future standardization. The CSE command uses only bit 1; all other bits shall be set to 0. + +#### 5.7.2.10 Reason (session or document) + +A field indicating the reason for sending the associated command or response. The value can either be given as a binary coded field or as plain text message. The absence of this parameter indicates that no reason is given. + +| Bits 87654321 | <i>Reason</i> | +|---------------|------------------------------------------------------------------------------------------------------------------| +| 00000000 | No specific reason stated (used for session or document reasons other than those listed). | +| 00000001 | Temporarily unable to enter into, or to continue, a session (e.g. due to memory full or out of recording paper). | +| 00000010 | Explicit text message only for use with RSSN (see Note 1). | +| 00000011 | Sequence error (see Note 2). | +| 00000101 | Local terminal error (see Note 2). | +| 00000110 | Unrecoverable procedural error (see Note 2). | + +##### NOTES + +1 For the basic Teletex service, the text follows immediately after the first byte of the value. Maximum of 69 characters (control characters included). Only characters convertible one-to-one to the telex alphabet (ITA2) shall be allowed. Teletex code shall be used. + +2 These parameter values are valid only in document commands and responses. + +#### 5.7.2.11 Inactivity timer + +- a) Bits 8 and 7 indicate the unit of inactivity timer value and bits 6 to 1 indicate the binary value in the range of 1 to 63. + +| Bits 87 | <i>Unit of timer</i> | +|---------|-------------------------| +| 00 | Second(s); | +| 01 | Minute(s); | +| 10 | Hour(s); | +| 11 | Reserved for extension. | + +- b) All bits of the first octet set to zero indicates the inactivity timer value is of infinity, i.e. the timer is disabled. + +#### 5.7.2.12 Session service functions + +The parameter value is indicated by a sequence of two octets. + +- a) In octet 1: + +| | | +|-----------------------|---------------------------------------------------------------------| +| Bits 8-4 (see Note 1) | Reserved (set to 0). | +| Bit 3 | Set to 1 to indicate the typed data capability (for further study). | +| Bit 2 (see Note 2) | Set to 1 to indicate the ability to send RDPBN. | +| Bit 1 (see Note 2) | Set to 1 to indicate the ability to send/receive CDCL/RDCLP. | + +- b) In octet 2: + +| | | +|---------------------------------|-----------------------------------------------------------| +| Bits 8, 6, 5 and 3 (see Note 1) | Reserved (set to 0). | +| Bit 7 (see Note 2) | Set to 1 to indicate the capability of document transfer. | + +| | | +|-----------------------|------------------------------------------------------------------------------| +| Bit 4 (see Note 2) | Set to 1 to indicate the capability of page synchronization [CDPB/RDPBP(N)]. | +| Bits 2-1 (see Note 3) | Set to 0 1 to indicate “half duplex”. | +| | Set to 1 0 to indicate “duplex”. | + +##### NOTES + +- 1 All bits reserved should be ignored when comparing capabilities indicated in CSS and RSSP. +- 2 The indicated bits should be set (to 1 for document transfer and to 0 for no document transfer) as a unit. +- 3 Half-duplex and duplex are for further study. + +The absence of this parameter should be interpreted as the following default values: + +| | | +|----------|----------| +| Bits | 87654321 | +| Octet 1: | 00000011 | +| Octet 2: | 01001001 | + +#### 5.7.2.13 Non-standardized capabilities + +The first octet represents the registered CCITT country code as specified in Recommendation T.35 to be used to identify non-standard capabilities. Additional octets, may be specified by each country's Administration. + +#### 5.7.2.14 Session user data + +Some parameters associated with this PGI are defined in the T.400-Series Recommendations. The maximum length of this user data field following the PGI and its LI is restricted to 512 octets. + +#### 5.7.2.15 Private use + +A set of PGI and PI values is designated as being for private use. Other than the PGIs designated for extensions and the permitted use of private parameters only with certain command and responses, the use of these parameters is not defined. + +### 5.7.3 Document related parameters + +NOTE – The following paragraphs include parameters commonly used by basic Teletex and Group 4 facsimile services. + +#### 5.7.3.1 Service interworking identifier + +Bit 1 of the first octet set to 1 shall indicate that the associated document is suitable for forwarding via the telex service. + +All other bit values are reserved for future standardization. + +#### 5.7.3.2 Document reference number + +A sequence of decimal digits as defined in this Recommendation and coded in Recommendation T.61. + +#### 5.7.3.3 Checkpoint reference number + +A sequence of decimal digits as defined in this Recommendation and coded in Recommendation T.61. + +#### 5.7.3.4 Acceptance of CDCL parameters + +Bit 1 of the first octet set to 1 indicates acceptance of all non-basic terminal capabilities which are defined in this Recommendation and requested by a CDCL command. + +All other bit values are reserved for future standardization. + +NOTE – Bit 1 of the first octet set to 1 does not indicate acceptance of non-basic terminal capabilities conveyed in the session under data of CDCL. + +#### 5.7.3.5 Storage capacity negotiation + +A fixed length sequence of two octets: + +- a) Bit 1 of the first octet set to 1 indicates that a terminal has reserved the requested amount of storage. +- b) Bit 2 of the first octet set to 1 indicates that the binary field in the following octet contains a number indicating storage capacity required/reserved in kilo-octets. +- c) Bit 5 of the first octet set to 1 indicates that the binary field in the following octet contains a number, which, when multiplied by 16, indicates storage capacity required/reserved in kilo-octets. +- d) Bit 6 of the first octet set to 1 indicates that the binary field in the following octet contains a number, which, when multiplied by 256, indicates storage capacity required/reserved in kilo-octets. +- e) Bit 3 of the first octet set to 1 indicates that a terminal cannot estimate its memory capacity. +- f) Bit 4 of the first octet set to 1 indicates that a terminal cannot now reserve the requested amount of memory. +- g) In the first octet, only one of bits 2, 5 and 6 may be set to 1. For negotiation of storage capacity less than or equal to 255 kilo-octets, bit 2 shall be used. + +NOTE – Use of bit 5 or 6 for negotiation of a storage capacity greater than 65 kilo-octets but less than or equal to 255 kilo-octets is not to be interpreted as a procedural error by the receiver. +- h) Bits 7 and 8 of the first octet are reserved for future standardization. + +Octet 2 indicates the memory size available and/or reserved (the meaning is defined in the first octet). It shall be set to 11111111 if bit 3 and/or 4 in the first octet is set to 1. + +In cases a), e) and f), the second octet may be ignored by the recipient of RDCLP. + +#### 5.7.3.6 Receiving ability jeopardized + +The first octet shall be encoded as follows: + +| Bits | 87654321 | Meaning | +|----------|----------|----------------------------------------------------| +| 00000000 | | Further traffic can be accepted. | +| 00000001 | | Ability to receive further traffic is jeopardized. | + +All other binary values are reserved for future standardization. + +#### 5.7.3.7 Document type identifier + +Absence of this parameter shall indicate a normal document. This parameter, if used, is a binary encoded field of fixed length of one octet identifying the document type as follows: + +| Bits | 87654321 | Type of document | +|----------|----------|--------------------| +| 00000001 | | Operator document. | +| 00000010 | | Control document. | +| 00000011 | | Monitor document. | + +All other encodings are reserved for future standardization. + +#### 5.7.3.8 Reflect parameter value + +This is an arbitrary length field that contains the bit pattern of the command or response up to and including the detected error. + +### 5.7.4 Document related parameter for teletex + +NOTE – The following parameters may also be used by services other than teletex. + +#### 5.7.4.1 Control character sets (refer to Recommendations T.60 and T.61) + +A variable length field indicating the receiving capability for non-basic standardized control character sets. Each such control character set shall be indicated by the sequence of characters used to designate that set, as defined in Recommendation T.61. Where more than one such character set are to be indicated, the ESC character fulfills the purpose of a separator between the character set indicators. + +**5.7.4.2 Graphic character sets** (refer to Recommendations T.60 and T.61) + +**5.7.4.2.1** A variable length field indicating the receiving capabilities for non-basic standardized graphic character sets. Each such graphic character sets or DRCS (dynamically redefinable character set) for Japanese Kanji and Chinese ideogram characters shall be indicated by the sequence of characters used to designate that set, as defined in Recommendation T.61. Where more than one such character set are to be indicated, the ESC character fulfills the purpose of a separator between the character set indicators. + +**5.7.4.2.2** The following descriptions apply to the use of a DRCS set for Japanese Kanji and Chinese ideogram characters: + +a) if the DRCS set is indicated as a parameter value associated with a CDS or CDC command, this should be followed by combinations of a character code (CC) to be registered to the DRCS set and its character dot pattern (DP); + +b) the field length of a character code is defined by the DRCS set and that of a character dot pattern is indicated as parameter values of a character box height and a character box width. + +NOTE – The PV field of this parameter in either CDS or CDC will be as follows: + +DRCS CC<sub>1</sub> EP<sub>1</sub> CC<sub>2</sub> DP<sub>2</sub> ... CC<sub>i</sub> DP<sub>i</sub> + +**5.7.4.3 Teletex page formats** (refer to Recommendations T.60 and T.61) + +The value of the first octet of the parameter value will indicate the capability of a page format, as defined in Table 11. If the terminal is capable of more than one format, these will be indicated in the first and subsequent octets, one octet per value (see Note 1 of Table 11). No separator between the values will be given. The length indicator of the parameter will indicate if more than one value is given. All parameter values shall be inserted in increasing order of their binary values. + +TABLE 11/T.62 + +| Bits | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | Format | | | | | | | | | | | | | | +|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----|-------------------------|---|---|---|---|---|---|----------|--------------------------------------------------------------------------------------------|------|----------|---------------------------------|--|-----|-------------------------|--|-----|-----------------|--|-----|----------------| +| | | 0 | 0 | 0 | 0 | 0 | 0 | 0 | | | 1 | (option) | ISO A4, horizontal and vertical | | | | | | | | | | +| | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | (option) | North American, horizontal and vertical | | | | | | | | | | | | | +| | 1 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | (option) | ISO A4 extended (ISO standard 3535), vertical | | | | | | | | | | | | | +| | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 0 | (option) | ISO A4 extended (ISO standard 3535), horizontal | | | | | | | | | | | | | +| | 1 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | (option) | North American legal, vertical | | | | | | | | | | | | | +| | 0 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | (option) | North American legal, horizontal | | | | | | | | | | | | | +| | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | (option) | ISO A4, horizontal and vertical (for use by Japanese Kanji and Chinese ideogram terminals) | | | | | | | | | | | | | +| | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | (option) | ISO B5, horizontal and vertical (for use by Japanese Kanji and Chinese ideogram terminals) | | | | | | | | | | | | | +| | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | (option) | ISO B4, horizontal and vertical (for use by Japanese Kanji and Chinese ideogram terminals) | | | | | | | | | | | | | +| NOTES<br>1 The whole octet has to be considered when decoded, since the meaning is coded as a value, not as a single bit position within the octet. All other values are reserved, i.e. it is not allowed to "combine" the indication of several formats into the same octet by setting more than one bit to "one".<br>2 The following rule is used for the coding of bits 7 and 8:<br><table style="margin-left: 300px;"> <tr> <td>Bits</td> <td>8 7</td> <td>Meaning</td> </tr> <tr> <td></td> <td>0 0</td> <td>Vertical and horizontal</td> </tr> <tr> <td></td> <td>0 1</td> <td>Horizontal only</td> </tr> <tr> <td></td> <td>1 0</td> <td>Vertical only.</td> </tr> </table> | | | | | | | | | | | Bits | 8 7 | Meaning | | 0 0 | Vertical and horizontal | | 0 1 | Horizontal only | | 1 0 | Vertical only. | +| Bits | 8 7 | Meaning | | | | | | | | | | | | | | | | | | | | | +| | 0 0 | Vertical and horizontal | | | | | | | | | | | | | | | | | | | | | +| | 0 1 | Horizontal only | | | | | | | | | | | | | | | | | | | | | +| | 1 0 | Vertical only. | | | | | | | | | | | | | | | | | | | | | + + Recommendation T.62 (03/93) 39 + +#### **5.7.4.4 Miscellaneous terminal capabilities** (refer to Recommendation T.61) + +A variable length field indicating the receiving capabilities for non-basic standardized values of character spacing, line spacing and graphic renditions. Each parameter value of such a function shall be indicated by the control sequence (CSI $P_i I_i F$ ) as defined in Recommendation T.61. This applies to the functions select horizontal spacing (SHS) for a character pitch, select vertical spacing (SVS) for a line pitch and select graphic rendition (SGR) for a graphic rendition. This also applies to the functions graphic size modification (GSM) and select presentation direction (SPD) for Japanese Kanji and Chinese ideogram capabilities, and to select character orientation (SCO) for Chinese ideogram capabilities. When more than one such character sequence is to be indicated, a single space shall be inserted between them. Only one parameter value is allowed within a CSI sequence. + +#### **5.7.4.5 Character box height** + +A variable length field indicating the receiving capabilities for the number of dots of the character box height. The number of dots shall be indicated by the numeric character as defined in Recommendation T.61. + +Further study is required for indicating more than one value. + +#### **5.7.4.6 Character box width** + +A variable length field indicating the receiving capabilities for the number of dots of the character box width. The number of dots shall be indicated by the numeric character as defined in Recommendation T.61. + +Further study is required for indicating more than one value. + +# **Annex A** + +## **Definitions** + +(This annex forms an integral part of this Recommendation) + +NOTE – Some of the terms used in this Recommendation have been defined in ways that may differ from the meanings of similar terms in other Recommendations. + +## **A.1 General** + +### **A.1.1 Teletex terminal** + +*F: terminal télétex* +*S: terminal teletex* + +A device that is capable of transmitting and receiving Teletex documents in accordance with the basic requirements of Recommendation T.60. + +### **A.1.2 call** + +*F: communication* +*S: comunicación* + +The temporary connection (or apparent connection as perceived by the caller) of one terminal to another for the purpose of exchanging information. + +### **A.1.3 calling terminal** + +*F: équipement terminal demandeur* +*S: terminal llamante (que llama)* + +The terminal that initiates the procedures to establish a call. + +### **A.1.4 called terminal** + +*F: équipement terminal demandé* + +*S: terminal llamado* + +The terminal to which a call is made. + +### **A.1.5 service interworking** + +*F: interfonctionnement de service* + +*S: interfuncionamiento de servicios* + +The facility of sending and receiving information between a Teletex terminal and a terminal of another service, e.g. telex. + +### **A.1.6 command** + +*F: commande* + +*S: instrucción; orden* + +A command is control information sent to another terminal to initiate execution of a specific function. Some commands require a response. + +### **A.1.7 response** + +*F: réponse* + +*S: respuesta* + +A response is control information sent by the recipient of the command to advise the sender of the command of the action taken. Exceptionally, the reaction to a response may be another response. + +### **A.1.8 source/sink relationship** + +*F: relation source/collecteur* + +*S: relación fuente/aceptor (o fuente/sumidero)* + +User information is transferred from a source to a sink. + +### **A.1.9 group 4 facsimile apparatus** + +*F: télécopieur du groupe 4* + +*S: aparato facsímil del grupo 4* + +A device that is capable of transmitting and receiving facsimile documents in accordance with the basic requirements of Recommendation T.5. + +## **A.2 Terms specific to session procedures** + +### **A.2.1 session** + +*F: session* + +*S: sesión* + +A session is the interval during which a logical, mutually agreed correspondence between two application/presentation processes exists for the transfer of application and presentation related information. + +### **A.2.2 Modes of session** + +There are three different modes: + +#### **A.2.2.1 one way communication (OWC)** + +*F: échange unidirectionnel (OWC)* + +*S: comunicación unidireccional (OWC)* + +User information is transferred in one direction only during the session, i.e. only one of the terminals will have the right to be the source. + +#### **A.2.2.2 two way alternate (TWA)** + +*F : échange bidirectionnel à l'alternat (TWA)* + +*S : modo bidireccional alternado (TWA)* + +User information is transferred in both directions, but only in one direction at a time, i.e. the source/sink relation will be changed one or more times during the session. + +#### **A.2.2.3 two way simultaneous (TWS)** + +*F : échange bidirectionnel simultané (TWS)* + +*S : modo bidireccional simultáneo (TWS)* + +User information is transferred in both directions simultaneously, i.e. both terminals are simultaneously a source as well as a sink. + +NOTE – TWS mode is for further study. + +### **A.2.3 basic session reference** + +*F : référence de base de la session* + +*S : referencia básica de la sesión* + +The basic session reference is used to identify a session. It consists of: + +- a) terminal identifier of the called terminal; +- b) terminal identifier of the calling terminal; +- c) date and time. + +### **A.2.4 expanded session reference** + +*F : référence élargie de la session* + +*S : referencia extendida de la sesión* + +The expanded session reference is used to identify a session uniquely. It consists of the mandatory basic session reference plus an optional additional session reference number. + +## **A.3 Terms specific to document procedures** + +### **A.3.1 document** + +*F : document* + +*S : documento* + +A document is a sequence of one or more pages intended by the originator to be delivered to the address(es) as a single entity in the original page sequence. + +### **A.3.2 page** + +*F : page* + +*S : página* + +The basic element of office correspondence in the Telematic services. One A4 (or A4L, North American Standard or North American Legal) page or the information that may be presented on it. + +### **A.3.3 checkpoint** + +*F : point de repère* + +*S : punto de comprobación; punto de validación* + +A checkpoint is a numbered mark inserted by the sender in the text stream to provide a reference point for error recovery. + +### **A.3.4 acknowledgement window** + +*F : fenêtre d'accusé de réception* + +*S : ventana de acuse de recibo* + +The maximum number of checkpoints that a sender can transmit without receiving an acknowledgement from the receiver. + +# Annex B + +## Telematic modes of operation + +(This annex forms an integral part of this Recommendation) + +## B.1 Introduction + +**B.1.1** The purpose of this annex is to provide for explanation on the Telematic modes of operation that are realized by the use of this Recommendation. + +## B.2 Telematic modes of operation + +There are three modes of operation defined for the Telematic services. + +**B.2.1 document transfer mode:** This mode allows only for transfer of documents without interactive capability. Procedures applying to this mode are defined in the main body of this Recommendation. + +**B.2.2 interactive mode:** This mode allows only for interactive dialogue. No document transfer can take place. Procedures applying to this mode are for further study. + +**B.2.3 document transfer and interactive mode:** This mode allows for interleaving of document transfer with interactive dialogue. Procedures applying to this mode are for further study. + +## B.3 Relationship between Telematic modes of operation and the OSI session services + +### B.3.1 Required session service subsets + +**B.3.1.1** The three modes of operation defined in B.2 above use different subsets of the OSI session services as illustrated in Figure B.1. + +![Diagram illustrating the relationship between Modes of operation and Session service subsets.](56680df276d8e8d21e5ed5c8e21527c6_img.jpg) + +The diagram illustrates the relationship between Modes of operation and Session service subsets. It is divided into two horizontal sections by a line. The top section, labeled 'Modes of operation' on the left, contains three boxes: 'Document transfer', 'Document transfer and interactive', and 'Interactive'. The bottom section, labeled 'Session service subsets' on the left, contains four boxes: 'Subset 2 half duplex', 'Subset 2 duplex', 'Subset 1 half duplex', and 'Subset 1 duplex'. Arrows indicate the following connections: 'Document transfer' connects to 'Subset 2 half duplex'; 'Document transfer and interactive' connects to both 'Subset 2 half duplex' and 'Subset 2 duplex'; 'Interactive' connects to both 'Subset 1 half duplex' and 'Subset 1 duplex'. + +T0817440-94/d07 + +Diagram illustrating the relationship between Modes of operation and Session service subsets. + +FIGURE B.1/T.62 + +Modes of operation and supporting session service subsets + +#### **B.3.1.2 Subset 1** + +This subset is composed of: + +- a) kernel functional unit; +- b) half-duplex functional unit; +- c) duplex functional unit; +- d) typed data functional unit. + +For one connection, only either duplex or half-duplex functional units can be selected. + +#### **B.3.1.3 Subset 2** + +This subset is composed of: + +- a) kernel functional unit; +- b) half-duplex functional unit; +- c) duplex functional unit; +- d) typed data functional unit; +- e) capability data exchange functional unit; +- f) minor synchronize functional unit; +- g) exception functional unit; +- h) activity management functional unit. + +Typed data functional unit is an option for the “interactive” and “document transfer and interactive” modes. + +Only half-duplex functional unit can be used for the document transfer mode. Either half-duplex or duplex functional unit can be used for “interactive” and “document transfer and interactive” modes. + +### **B.3.2 Restrictions on the use of the session services** + +**B.3.2.1** Every mode of operation specifies how it uses the session services. This encompasses restrictions put on the generality offered by the session services. A number of them are reflected in the state transition diagrams given in Annex G. For this, these state transition diagrams take into account only those sequences of events, which are valid in the respective mode of operation, at the session layer boundary. + +### **B.3.3 Selection of a specific mode** + +**B.3.3.1** The selection of a particular mode is achieved through the negotiation of the session services available over the established session. + +**B.3.3.2** Table B.1 summarizes different cases that may occur and the results of the negotiation. + +NOTE – The availability of the typed data service has no impact on the selection of a mode. If the availability of this has been agreed to, it can be used in any mode. + +**B.3.3.2.1** The result of the negotiation of the session services can be: + +- a) the functionalities of the subset 2 have been agreed to. The duplex mode is in use; +- b) the functionalities of the subset 2 have been agreed to. The half-duplex mode is in use; +- c) only the functionalities of the subset 1 have been retained by both systems. + +**B.3.3.2.2** The combination of the supported capabilities can be: + +- d) document transfer is the only capability commonly supported by both systems; +- e) both systems have indicated that they have the interactive capability. + +TABLE B.1/T.62 + +#### **Selection of a mode of operation** + +| | a) | b) | c) | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------|----------|---------| +| d) | – | Mode I | – | +| e) | Mode III | Mode III | Mode II | +| <p>NOTES</p> <p>1 Modes I, II and III stand for “document transfer”, “interactive” and “document transfer and interactive” modes, respectively.</p> <p>2 Cases a) to c) are explained in B.3.3.2.1, cases d) and e) in B.3.3.2.2.</p> | | | | + +# **Annex C** + +## **Definition of valid/invalid session protocol data units** + +(This annex forms an integral part of this Recommendation) + +## **C.1 Introduction** + +This annex is intended to provide the comprehensive definition and rules on valid/invalid session protocol data units (SPDUs). + +## **C.2 Invalid protocol data units (PDUs) (definition and rules)** + +If the command/response PDUs do not meet the following conditions, such PDUs are invalid: + +- a) the sum of the length indicators (LIs) of parameter group identifiers (PGIs) and freestanding parameter identifiers (PIs) is equal to the overall LI; +- b) the sum of the LIs of PIs embedded within recognized PGIs is equal to the PGIs LI; +- c) for all mandatory parameters, the PGIs or PIs are present and the LIs are not equal to zero. + +### NOTES + +1 In case of CSA, RSAP and RSSN PDUs, the same checking rules may be applied. However, it is recognized that no externally visible procedure is provided to react to the detection of such invalid PDUs. + +2 Invalid RDPBN or RDGR can either be rejected or processed normally to start error recovery. + +3 When receiving an invalid CSS it is recommended that the connection be refused by serving an RSSN with the appropriate parameters and not to release the transport connection. + +4 An equipment is not required to make any checking at all on parameters it does not support. In such cases it may also omit the checking of the overall LI. In particular it should be noted that not recognized parameters, e.g. new parameters, may appear either between supported parameters or after the complete set of supported parameters. + +## **C.3 Valid PDUs (rules for mandatory acceptance of PDUs)** + +An SPDU shall not be rejected if it does not meet the rejection conditions described in C.2. They must not be rejected for any of the following conditions: + +- a) the presence of a non-mandatory PI or PGI of having an LI = 0; +- b) the presence of any 3-octet LI, the coding of which follows the rules described in 5.3.3; +- c) the presence of any correctly formed parameter value (PV) for which future values can be assigned; + +- d) the presence of one or more undefined PIs or PGIs in CSS or CDCL and their corresponding responses; +- e) the presence of a T.61 coded hyphen (“-”) instead of a colon (“:”) as the separator between the hours and minutes of the date and time PV in CSS; +- f) a greater or smaller length of the CRN (checkpoint reference number) in RDPBP than the CRN in the corresponding CDPB (with more or less preceding zeros); +- g) more PVs in RSSP or RSSN than in CSS. + +NOTE – The scope of these rules are restricted to the determination of protocol element validity (formal validity) and do not impact on rejection of protocol elements due to the functions they invoke. + +# **Annex D** + +## **General description and rules of operation for state diagrams** + +((This annex forms an integral part of this Recommendation)) + +- D.1** Each state diagram is in only one state at any time. +- D.2** Each state is represented as an ellipse, which contains a number for reference and a descriptive name. +- D.3** Permissible transitions from one state to another are shown as connecting lines with an arrow indicating the permitted direction of the state transition and labelled with the event or events that cause that transition. +- D.4** Where a transition may originate from any of several states, it may be indicated by a broad arrow terminating on the destination state and labelled with the permissible states of origination and with the event or events that cause that entry into the destination state. +- D.5** An event is either the sending (S-) or reception (R-) of a command or a response or an indicated local operation. +- D.6** Each state diagram has a state named “idle” and numbered zero. This is the initial or reset state when that state diagram is inactive. +- D.7** Upon sending any command that causes entry into a state named “demand response”, the sending of any additional commands is not permitted until a response is received. A demand response timer is started, and, if a response is not received prior to expiration of that time-out, session termination, either directly if command session abort (CSA) was sent, or by sending CSA, is mandatory. +- D.8** The effect of each event that causes a state transition must be completed prior to consideration of a subsequent event. +- D.9** During a session, each session partner has a responsibility for monitoring for proper operation as follows: + - a) maintenance of the currently agreed source/sink relationship; + - b) proper use of command/response procedural sequences as described in the state diagrams and the rules for their operation; + - c) monitoring for a period of inactivity (e.g. indicating a failure or other inability to continue productive use of the session). + +Upon detection of a failure to maintain proper operation as described above, use of error recovery procedures defined for each state diagram is mandatory, or where such error recovery procedures are not specifically defined, session termination (abnormal end) is mandatory. This is necessary in order to avoid unproductive use of telematic facilities, incurring unnecessary charges where the service is not being used effectively, and causing degradation of the service. + +- D.10** The purpose of the state diagrams is to assist in defining proper use of the elements of procedure, and not to define any particular implementation. + +# **Annex E** + +## **Types of document** + +(This annex forms an integral part of this Recommendation) + +## **E.1 General** + +**E.1.1** An indication of the type of document that is transferred shall be given at the start of each document; if not, the normal type of document is used. + +**E.1.2** A document type indication will indicate to the operating system of the receiving terminal that a special action is required (the action is defined for each type of document). + +**E.1.3** No additional procedure elements or changes in state transition diagrams are required. + +## **E.2 Normal document** + +**E.2.1** This is the normal type of document to be used to transfer text in the Telematic services. Upon reception, the document may be immediately printed (in the case of G4 facsimile Class 1) or be immediately stored (all other terminals). + +**E.2.2** From the procedures point of view, every Teletex terminal must be able to handle this type of document. + +NOTE – Where appropriate, the rules for the usage of optional functions have to be followed. + +## **E.3 Operator document (optional)** + +**E.3.1** The operator document represents a type of priority message. It can be used in the conversational mode of operation. + +It is intended to be presented immediately to the operator (although the decision to present it is left to the receiving operator). It may therefore be immediately indicated to the operator that a new operator document has been received. The operator document shall conform to the same presentation control functions and be treated in the procedure as a normal document. The length of an operator document is arbitrary but, preferably (due to the application), it shall not exceed one page. Note that a terminal that does not have a special dialogue mode can handle an operator document as a normal document. + +## **E.4 Control document** + +**E.4.1** The control document can be used in communication with intermediate store-and-forward equipment; e.g. interworking with the telex service, in standardized options and national applications. + +**E.4.2** The addressing information (and other control information required) can be included as text within such a document. The control document shall, except for the document type indication, follow the same rules (in the procedure) as a normal document. The use of the control document is outside the scope of this Recommendation. + +**E.4.3** Teletex terminals shall be able to support the control documents defined, in Recommendation T.90, for interworking with the telex service. + +## **E.5 Monitor document (optional)** + +**E.5.1** The monitor document will not be made available to the user. It is intended to be available for purposes that can be defined by each Administration, e.g. for maintenance purposes. + +**E.5.2** The monitor document will be handled by the operating system of the terminal and not displayed to the operator. The monitor document shall, except for the document type indication, conform to the same rules (in the procedure) as a normal document. + +# Annex F + +## Interactive session protocol and typed data transfer for the Telematic services + +(This annex forms an integral part of this Recommendation) + +NOTE – Further study is required for such capabilities. + +# Annex G + +## Detailed state transition diagrams for session/document procedures + +(This annex forms an integral part of this Recommendation) + +## G.1 General + +This annex provides detailed state transition diagrams for session/document procedures for the basic services. These diagrams are modelled using the terminology of the open systems interconnection (OSI) model and are aligned with the latest understanding of the CCITT and ISO activities on the OSI session layer. These diagrams are also aligned with the state transition diagrams in this Recommendation but assume a window- independent mechanism. + +## G.2 Description on notations + +**G.2.1** These diagrams use a presentation method which provides the following levels of description. + +### a) *Protocol level* + +This level addresses only the peer to peer protocol activities between two session entities. It identifies the protocol states, events [receipt of session protocol data units (SPDUs)] and actions (sending of SPDUs). + +### b) *Detailed level* + +This level addresses the inter-layer and local activities (e.g. management of timers, counters, etc.). It identifies the events, actions and states within each of the protocol level states. The inter-layer activities are described using the session service primitives defined in G.3. + +### G.2.2 Presentation symbols + +#### G.2.2.1 State S + +![Diagram of State S: An oval shape containing the letter 'S'.](3606e4bf364833083bb56188301933ca_img.jpg) + +T0817450-94/d08 + +Diagram of State S: An oval shape containing the letter 'S'. + +#### G.2.2.2 Action A + +![Diagram of Action A: A rectangular shape containing the letter 'A'.](5059950dfb4d23591af5f575fab959d3_img.jpg) + +T0817450-94/d09 + +Diagram of Action A: A rectangular shape containing the letter 'A'. + +**G.2.2.3** If condition C is true, then action $a_1$ , otherwise, action $a_2$ . + +![Flowchart for G.2.2.3 showing a decision diamond labeled 'C'. An arrow enters the top of the diamond. A 'Yes' branch exits the left side and leads to action 'a1'. A 'No' branch exits the bottom and leads to action 'a2'.](fc02903382cebe6fc11e4c0d74b5313f_img.jpg) + +``` +graph TD; Entry(( )) --> C{C}; C -- Yes --> a1[a1]; C -- No --> a2[a2]; +``` + +T0817450-94/d10 + +Flowchart for G.2.2.3 showing a decision diamond labeled 'C'. An arrow enters the top of the diamond. A 'Yes' branch exits the left side and leads to action 'a1'. A 'No' branch exits the bottom and leads to action 'a2'. + +**G.2.2.4** Event E + +![Diagram for G.2.2.4 showing a horizontal arrow pointing right, labeled 'E' above it.](a0e8fe7862a6d7341faf5dac275277cc_img.jpg) + +``` +graph LR; E --> Right[ ]; +``` + +T0817450-94/d11 + +Diagram for G.2.2.4 showing a horizontal arrow pointing right, labeled 'E' above it. + +**G.2.2.5** Send SPDU action + +![Diagram for G.2.2.5 showing a horizontal arrow pointing right, labeled 'S-SPDU' above it.](df1966d80c74bc127f159a48f38b13ee_img.jpg) + +``` +graph LR; S-SPDU --> Right[ ]; +``` + +T0817450-94/d12 + +Diagram for G.2.2.5 showing a horizontal arrow pointing right, labeled 'S-SPDU' above it. + +**G.2.2.6** Receive SPDU event + +![Diagram for G.2.2.6 showing a horizontal arrow pointing right, labeled 'R-SPDU' above it.](458fdbcb4015a4ee90bd84809afc4aac_img.jpg) + +``` +graph LR; R-SPDU --> Right[ ]; +``` + +T0817450-94/d13 + +Diagram for G.2.2.6 showing a horizontal arrow pointing right, labeled 'R-SPDU' above it. + +**G.2.2.7** Timers + +- a) *Timer T1* – Inactivity timer, value as determined by inactivity timer value negotiation. +- b) *Timer T2* – Demand response timer, value 60s [see the Note in 4.1.1.d)]. +- c) *Timer T3* – CSA timer of, for example, 4 seconds. + +### G.2.3 Notes + +**G.2.3.1** With regard to the interactions between session and transport layers, the following is assumed: + +- a) Each SPDU is transferred by “T-DATA req”. The transport service data unit (TSDU) will contain the SPDU; +- b) Each SPDU is received by “T-DATA ind”. The TSDU will contain the SPDU. + +**G.2.3.2** The management of the various timers requires further study. + +**G.2.3.3** Response (or confirm) service primitive shall indicate a positive response (or confirm) unless otherwise stated. + +### G.2.4 Abbreviations + +**G.2.4.1** The abbreviations contained in Table G.1 apply to the description of service primitives. + +TABLE G.1/T.62 + +**Abbreviation of service primitives** + +| Abbreviation | Meaning | Abbreviation | Meaning | +|--------------|-----------------|--------------|---------------| +| CON | Connection | REL | Release | +| CONF | Confirmation | REQ | Request | +| IND | Indication | RESP | Response | +| POS | Positive | NEG | Negative | +| S | Session | U | User | +| P | Provider | BEG | Begin | +| CONT | Continue | ACT | Activity | +| SYNC | Synchronization | MIN | Minor | +| EXPT | Exception | CAPAB | Capability | +| ERR | Error | FAIL | Failure | +| CTRL | Control | PLS | Please | +| INT | Interrupt | ABT | Abort | +| DCAD | Discard | DISC | Disconnection | + +## G.3 Service primitives + +The following illustrates the service primitives and associated SPDUs for the basic session/document control procedures. + +### G.3.1 Service primitives for the services provided to the session/document user + +#### G.3.1.1 Session connection + +![Sequence diagram illustrating the session connection process between a Calling party and a Called party.](1230eaa9d75a09d7e7b8509931e9190e_img.jpg) + +``` +sequenceDiagram + participant C as Calling + participant Ca as Called + C->>Ca: S-CON REQ + Note over C,Ca: CSS + Ca->>C: S-CON IND + Ca-->>C: S-CON RESP (positive or negative) + C-->>Ca: S-CON CONF (positive or negative) + Note over C,Ca: RSSP or RSSN +``` + +The diagram shows the sequence of service primitives for a session connection. It starts with a 'Calling' party sending an 'S-CON REQ' to a 'Called' party. This is followed by a 'CSS' (Call Setup Signaling) phase. The 'Called' party then sends an 'S-CON IND' back to the 'Calling' party. Finally, the 'Called' party sends an 'S-CON RESP (positive or negative)' to the 'Calling' party, and the 'Calling' party sends an 'S-CON CONF (positive or negative)' back to the 'Called' party. The entire process is governed by 'RSSP or RSSN' (Request/Response Signaling Primitives or Signaling Service Primitives). + +T0817460-94/d14 + +Sequence diagram illustrating the session connection process between a Calling party and a Called party. + +#### G.3.1.2 Session release + +![Sequence diagram for Session release (G.3.1.2).](284768c5ee1a05aa1b9ce396f606a040_img.jpg) + +Sequence diagram for Session release (G.3.1.2). The diagram shows two entities: *Calling* and *Called*. The *Calling* entity sends an S-REL REQ message to the *Called* entity. The *Called* entity sends an S-REL IND message back to the *Calling* entity. The *Calling* entity sends an S-REL CONF message to the *Called* entity. The *Called* entity sends an S-REL RESP message back to the *Calling* entity. The diagram is labeled T0817460-94/d15. + +``` + +sequenceDiagram + participant Calling + participant Called + Calling->>Called: S-REL REQ + Called->>Calling: S-REL IND + Calling->>Called: S-REL CONF + Called->>Calling: S-REL RESP + +``` + +T0817460-94/d15 + +Sequence diagram for Session release (G.3.1.2). + +#### G.3.1.3 Session user abort + +![Sequence diagram for Session user abort (G.3.1.3).](9e8ebf03cae78f4f81b697548c2d7250_img.jpg) + +Sequence diagram for Session user abort (G.3.1.3). The diagram shows two entities: *Calling or called* and *Called or calling*. The *Calling or called* entity sends an S-U-ABT REQ message to the *Called or calling* entity. The *Called or calling* entity sends an S-U-ABT IND message back to the *Calling or called* entity. The *Calling or called* entity sends an S-U-ABT CONF message to the *Called or calling* entity. The *Called or calling* entity sends an S-U-ABT RESP message back to the *Calling or called* entity. The diagram is labeled T0817460-94/D16. + +``` + +sequenceDiagram + participant Calling_or_called as Calling or called + participant Called_or_calling as Called or calling + Calling_or_called->>Called_or_calling: S-U-ABT REQ + Called_or_calling->>Calling_or_called: S-U-ABT IND + Calling_or_called->>Called_or_calling: S-U-ABT CONF + Called_or_calling->>Calling_or_called: S-U-ABT RESP + +``` + +T0817460-94/D16 + +Sequence diagram for Session user abort (G.3.1.3). + +#### G.3.1.4 Session provider abort + +![Sequence diagram for Session provider abort (G.3.1.4).](18e519d1f91133e080347562f681dfb5_img.jpg) + +Sequence diagram for Session provider abort (G.3.1.4). The diagram shows a single entity *Calling or called*. The entity sends an S-P-ABT IND message to itself. The diagram is labeled T0817460-94/d17. + +``` + +sequenceDiagram + participant Calling_or_called as Calling or called + Calling_or_called->>Calling_or_called: S-P-ABT IND + +``` + +T0817460-94/d17 + +Sequence diagram for Session provider abort (G.3.1.4). + +#### G.3.1.5 Session control give + +![Sequence diagram for Session control give (G.3.1.5).](3e2dcee303cecdd31b7f9ec0d8942fed_img.jpg) + +Sequence diagram for Session control give (G.3.1.5). The diagram shows two entities: *Current source* and *Current sink*. The *Current source* entity sends an S-CTRL GIVE REQ message to the *Current sink* entity. The *Current sink* entity sends an S-CTRL GIVE IND message back to the *Current source* entity. The *Current source* entity sends an S-CTRL GIVE CONF message to the *Current sink* entity. The *Current sink* entity sends an S-CTRL GIVE RESP message back to the *Current source* entity. The diagram is labeled T0817460-94/d18. + +``` + +sequenceDiagram + participant Current_source + participant Current_sink + Current_source->>Current_sink: S-CTRL GIVE REQ + Current_sink->>Current_source: S-CTRL GIVE IND + Current_source->>Current_sink: S-CTRL GIVE CONF + Current_sink->>Current_source: S-CTRL GIVE RESP + +``` + +T0817460-94/d18 + +Sequence diagram for Session control give (G.3.1.5). + +#### G.3.1.6 Session token please + +![Sequence diagram for Session token please](b2cc37ae1974ec7b87b91f54963b855d_img.jpg) + +Sequence diagram illustrating the 'Session token please' interaction: + +- Current sink** sends **S-TOKEN PLS REQ** to **Current source**. +- Current source** sends **RSUI with document element and request control bit set to 1** to **Current sink**. +- Current source** sends **S-TOKEN PLS IND** to **Current sink**. + +T0817470-94/d19 + +Sequence diagram for Session token please + +#### G.3.1.7 Session activity begin (start or continue) + +![Sequence diagram for Session activity begin (start or continue)](2cf3896394a2342a2b46c504ab9a8830_img.jpg) + +Sequence diagram illustrating the 'Session activity begin (start or continue)' interaction: + +- Current source** sends **S-ACT BEG (START or CONT) REQ** to **Current sink**. +- Current sink** sends **CSUI/CDS or CSUI/CDC** to **Current source**. +- Current sink** sends **S-ACT BEG (START or CONT) IND** to **Current source**. + +T0817470-94/d20 + +Sequence diagram for Session activity begin (start or continue) + +#### G.3.1.8 Session data transfer + +![Sequence diagram for Session data transfer](cc6f9dbfc36aa5821d9749ca84861f93_img.jpg) + +Sequence diagram illustrating the 'Session data transfer' interaction: + +- Current source** sends **S-DATA REQ** to **Current sink**. +- Current sink** sends **CSUI/CDUI** to **Current source**. +- Current sink** sends **S-DATA IND** to **Current source**. + +T0817470-94/d21 + +Sequence diagram for Session data transfer + +#### G.3.1.9 Session synchronization minor + +![Sequence diagram for Session synchronization minor](0997dbaa9dfecedd60029d70b53327b8_img.jpg) + +Sequence diagram illustrating the 'Session synchronization minor' interaction: + +- Current source** sends **S-SYNC MIN REQ** to **Current sink**. +- Current sink** sends **S-SYNC MIN IND** to **Current source**. +- Current sink** sends **S-SYNC MIN RESP or S-U-EXPT REQ** to **Current source**. +- Current source** sends **S-SYNC MIN CONF or S-U-EXPT IND** to **Current sink**. +- Current source** sends **RSUI/RDPBP or RSUI/RDPBN** to **Current sink**. + +T0817470-94/d22 + +Sequence diagram for Session synchronization minor + +#### G.3.1.10 Session activity end + +![Sequence diagram for Session activity end (G.3.1.10).](8a9f4764511ce90622893ec65c065eeb_img.jpg) + +Sequence diagram for Session activity end (G.3.1.10). The diagram shows interactions between a **Current source** and a **Current sink**. + +- The **Current source** sends **S-ACT END REQ** to the **Current sink**. +- The **Current sink** sends **S-ACT END IND** to the **Current source**. +- The **Current sink** sends **S-ACT END RESP or S-U-EXPT REQ** to the **Current source**. +- The **Current source** sends **CSUI/CDE** to the **Current sink**. +- The **Current source** sends **RSUI/RDEP or RSUI/RDPBN** to the **Current sink**. + +T0817470-94/d23 + +Sequence diagram for Session activity end (G.3.1.10). + +#### G.3.1.11 Session activity interrupt + +![Sequence diagram for Session activity interrupt (G.3.1.11).](7ed5d5770331f31ade15439a21c31425_img.jpg) + +Sequence diagram for Session activity interrupt (G.3.1.11). The diagram shows interactions between a **Current source** and a **Current sink**. + +- The **Current source** sends **S-ACT INT REQ** to the **Current sink**. +- The **Current sink** sends **S-ACT INT IND** to the **Current source**. +- The **Current sink** sends **S-ACT INT RESP** to the **Current source**. +- The **Current source** sends **CSUI/CDR** to the **Current sink**. +- The **Current source** sends **RSUI/RDRP** to the **Current sink**. + +T0817480-94/d24 + +Sequence diagram for Session activity interrupt (G.3.1.11). + +#### G.3.1.12 Session activity discard + +![Sequence diagram for Session activity discard (G.3.1.12).](c419b566d720267c499087add1506018_img.jpg) + +Sequence diagram for Session activity discard (G.3.1.12). The diagram shows interactions between a **Current source** and a **Current sink**. + +- The **Current source** sends **S-ACT DCAD REQ** to the **Current sink**. +- The **Current sink** sends **S-ACT DCAD IND** to the **Current source**. +- The **Current sink** sends **S-ACT DCAD RESP** to the **Current source**. +- The **Current source** sends **CSUI/CDD** to the **Current sink**. +- The **Current source** sends **RSUI/RDDP** to the **Current sink**. + +T0817480-94/d25 + +Sequence diagram for Session activity discard (G.3.1.12). + +#### G.3.1.13 Session capability data + +![Sequence diagram for Session capability data (G.3.1.13).](d7948c38a18636aefecdd95388196460_img.jpg) + +Sequence diagram for Session capability data (G.3.1.13). The diagram shows interactions between a **Current source** and a **Current sink**. + +- The **Current source** sends **S-CAPAB DATA REQ** to the **Current sink**. +- The **Current sink** sends **S-CAPAB DATA IND** to the **Current source**. +- The **Current sink** sends **S-CAPAB DATA RESP** to the **Current source**. +- The **Current source** sends **CSUI/CDCL** to the **Current sink**. +- The **Current source** sends **RSUI/RDCLP** to the **Current sink**. + +T0817480-94/d26 + +Sequence diagram for Session capability data (G.3.1.13). + +#### G.3.1.14 Session user exception reporting + +![Sequence diagram for Session user exception reporting showing a message exchange between a Current sink and a Current source.](7d929ba1b7d09ea8e00b9e7abbbe50c9_img.jpg) + +``` + +sequenceDiagram + participant CS as Current sink + participant CU as Current source + CS->>CU: S-U-EXPT REQ + CU-->>CS: RSUI/RDPBN + +``` + +T0817480-94/d27 + +Sequence diagram for Session user exception reporting showing a message exchange between a Current sink and a Current source. + +#### G.3.1.15 Session provider exception reporting + +![Sequence diagram for Session provider exception reporting showing a message exchange between a Calling or called entity.](3337af75dfee8af7687b4f49914d6c93_img.jpg) + +``` + +sequenceDiagram + participant CC as Calling or called + CC->>CC: S-P-EXPT IND (ERR or FAIL) + +``` + +T0817480-94/d28 + +Sequence diagram for Session provider exception reporting showing a message exchange between a Calling or called entity. + +NOTE – This primitive carries one of the following parameters: + +- a) ERR – to invite the application to take appropriate action (CDR, CDD, CSA or RDPBN); +- b) FAIL – to invite the application to abort (CSA). + +### G.3.2 Service primitives for the services expected from the transport layer + +#### G.3.2.1 Transport connection + +![Sequence diagram for Transport connection showing a message exchange between a Calling entity and a Called entity.](39536a630fa74c3bcfd1670ee2152809_img.jpg) + +``` + +sequenceDiagram + participant C as Calling + participant CA as Called + C->>CA: T-CON REQ + CA-->>C: T-CON IND + CA->>C: T-CON RESP or T-DISC REQ + C-->>CA: T-CON CONF or T-DISC IND + +``` + +T0817490-94/d29 + +Sequence diagram for Transport connection showing a message exchange between a Calling entity and a Called entity. + +#### G.3.2.2 Transport disconnection (implicit) + +![Sequence diagram for Transport disconnection (implicit) showing a message exchange between a Calling or called entity and a Called or calling entity.](17439b945bd5156395c7ba15bf04f8fb_img.jpg) + +``` + +sequenceDiagram + participant CC as Calling or called + participant CC2 as Called or calling + CC->>CC2: T-DISC REQ + CC2-->>CC: T-DISC IND + +``` + +T0817490-94/d30 + +Sequence diagram for Transport disconnection (implicit) showing a message exchange between a Calling or called entity and a Called or calling entity. + +#### G.3.2.3 Transport data transfer + +![Sequence diagram for transport data transfer showing T-DATA REQ and T-DATA IND messages between calling and called sides.](9cd85f266cdb1fb3ad544eb3dd3bd5e4_img.jpg) + +Sequence diagram illustrating transport data transfer: + +- On the left, under the label *Calling or called*, a downward arrow is labeled T-DATA REQ. +- On the right, under the label *Called or calling*, an upward arrow is labeled T-DATA IND. +- A horizontal line connects the two sides, with the reference T0817490-94/d31 centered below it. + +Sequence diagram for transport data transfer showing T-DATA REQ and T-DATA IND messages between calling and called sides. + +#### G.3.2.4 Transport exception reporting (optional and not part of OSI transport class 0) + +![Sequence diagram for transport exception reporting showing T-EXPT IND message.](9b1ec0090070bdf52ea28763b8d52477_img.jpg) + +Sequence diagram illustrating transport exception reporting: + +- On the left, under the label *Calling or called*, an upward arrow is labeled T-EXPT IND. +- The reference T0817490-94/d32 is centered below the arrow. + +Sequence diagram for transport exception reporting showing T-EXPT IND message. + +## G.4 Detailed state transition diagrams for the basic services + +**G.4.1** Figures G.1 and G.2 illustrate the detailed state transition diagrams for the calling and the called sides, respectively. + +**G.4.2** Figures G.3 and G.4 illustrate the detailed state transition diagrams for the sending and the receiving protocols, respectively. + +![Teletex session state transition diagram (calling side) showing various states and transitions between them.](c2c4e63ebb9afc1ab64e39a159890e0f_img.jpg) + +The diagram illustrates the state transitions for a Teletex session on the calling side. It consists of several states, each represented by an oval containing specific actions and timers. Transitions between these states are triggered by various events and messages. + +**States and their internal logic:** + +- Initial State (Top Left):** Contains the note "Any state except 0.1, 0.2, 0.3, 7.1, 14.1". A transition labeled "R-CSA (Note)" leads to State 7. +- State 7:** Contains "Stop T1, T2", "S-U-ABT IND", and a "7.1 Wait" timer. Transitions include "T-EXPT IND" (to "Discard"), "S-U-ABT RESP" (to "7.1 Wait"), and "R-Any PDU" (to "7.1 Wait"). A transition labeled "S-RSAP" leads to State 0. +- State 0:** A central state with two main modes: "0.1 Idle (transport disconnected)" and "0.2 Idle (transport connected)". It includes "S-P ABT IND", "T-DISC REQ", "T-DISC IND", "T-CON REQ", "T-CON CONF", "S-CON REQ", "S-CON NEG", "S-REL CONF", and a decision diamond "Transport disconnection required?". Transitions include "T-DISC IND" (to "0.1 Idle"), "T-CON REQ" (to "0.2 Idle"), "T-CON CONF" (to "0.2 Idle"), "S-CON REQ" (to "0.2 Idle"), "S-CON NEG" (to "0.1 Idle"), "S-REL CONF" (to "0.2 Idle"), and "T-DISC REQ" (to "0.1 Idle"). A transition labeled "R-RSSN" leads to State 8. +- State 8:** Contains "Start T2" and an "8.1 Wait" timer. Transitions include "R-RSSP" (to State 9) and "S-CSS" (to State 0). +- State 9:** Contains "Stop T2", "S-CON CONF", "DS Doc. send", "S-REL REQ", and "S-CTRL GIVE REQ". Transitions include "S-RSCCP" (to State 12), "S-CSCC" (to State 10), and "R-RSEP" (to State 0). +- State 12:** Contains "S-CTRL GIVE IND", "12.1 Wait", "S-CTRL GIVE RESP", and "Stop T1". Transitions include "R-CSCC" (to State 11) and "S-RSCCP" (to State 9). +- State 11:** Contains "DR Doc. receive", "Stop T2", "Start T1", and "S-CTRL GIVE CONF". Transitions include "R-RSCCP" (to State 10) and "S-RSCCP" (to State 9). +- State 10:** Contains "Start T2" and a "10.1 Wait" timer. Transitions include "R-RSCCP" (to State 11) and "S-CSCC" (to State 9). +- State 13:** Contains "Start T2" and a "13.1 Wait" timer. Transitions include "R-RSEP" (to State 0) and "S-CSE (Note)" (to State 9). +- State 14:** Contains "Start T3", "T-EXPT IND", "Discard", and a "14.1 Wait" timer. Transitions include "R-Any PDU except RSAP" (to "14.1 Wait") and "R-RSAP" (to State 0). +- State 14.1:** Contains "Any state except 0.1, 0.2, 0.3, 7.1, 14.1 X". Transitions include "S-U-ABT REQ" (to "14.1 Wait") and "Timeout or T-EXPT IND" (to "14.1 Wait"). A transition labeled "R-Invalid PDU" leads to "S-P-EXPT (Fail) IND", which then leads to "X Wait", which leads to "S-U-ABT REQ", which leads to "14.1 Wait". + +**Legend:** + +- T1 Inactivity timer +- T2 Demand response timer +- T3 CSA timer + +**NOTE** – With or without transport release bit set. + +Teletex session state transition diagram (calling side) showing various states and transitions between them. + +T0817500-94/d33 + +FIGURE G.1/T.62 +Teletex session state transition diagram (calling side) + +![Teletex session state transition diagram (called side) showing various states and transitions between them.](6f11044c88ea04e43de06c3491defeee_img.jpg) + +The diagram illustrates the state transitions for a Teletex session on the called side. It consists of several states, each represented by an oval, and transitions between them triggered by specific events. + +**States:** + +- Initial State:** Any state except 0.1, 0.2, 7.1, 14.1 +- State 7:** Contains 'Stop T1, T2', 'Discard', and 'S-U-ABT IND'. Transitions: 'T-EXPT IND' to '7.1 Wait'; 'S-U-ABT RESP' to '7.1 Wait'. +- State 7.1 Wait:** Transitions: 'S-RSAP' to '0.1 Idle transport disconnected'; 'S-RSEP' to '6.1 Wait'. +- State 0.1 Idle transport disconnected:** Transitions: 'T-CON IND' to 'T-Connection acceptable?'; 'T-DISC REQ' to 'T-DISC REQ'; 'S-P ABT IND' to 'Stop T3'; 'S-U-ABT CONF' to 'Transport disconnection required?'; 'T-EXPT IND' to 'Start T1'; 'R-Invalid PDU' to '0.2 Idle transport connected'. +- State 0.2 Idle transport connected:** Transitions: 'T-CON RESP' to 'Start T1'; 'T-DISC IND' to 'Start T1'; 'T-EXPT IND' to 'Start T1'; 'R-Invalid PDU' to '0.1 Idle transport disconnected'; 'R-CSS' to '1.1 Wait'; 'R-CSCC' to '3.1 Wait'; 'S-RSSP' to '1.1 Wait'. +- State 6.1 Wait:** Transitions: 'S-REL IND' to 'Stop T1'; 'S-REL RESP' to '6.1 Wait'. +- State 1.1 Wait:** Transitions: 'S-CON IND' to 'S-CON RESP NEG'; 'S-CON RESP' to 'Start T1'. +- State 2 DR Doc. Receive:** Transitions: 'S-CTRL GIVE CONF' to 'Stop T2 Start T1'. +- State 3.1 Wait:** Transitions: 'S-CTRL GIVE IND' to 'S-CTRL GIVE RESP'; 'S-CTRL GIVE RESP' to 'Start T2'. +- State 5.1 Wait:** Transitions: 'Start T2' to '5.1 Wait'. +- State 4 DS Doc. send:** Transitions: 'S-CTRL GIVE REQ' to 'S-RSCCP'. +- State 3 Stop T1:** Transitions: 'S-CTRL GIVE IND' to '3.1 Wait'. +- State 14.1 Wait:** Transitions: 'Start T3' to '14.1 Wait'; 'T-EXPT IND' to 'Discard'; 'Discard' to '14.1 Wait'. + +**Transitions and Events:** + +- R-Invalid PDU:** Triggers transitions from State 0.1 to 0.2 and from State 0.2 to 0.1. +- S-RSAP:** Triggers transition from State 7.1 Wait to State 0.1. +- S-RSEP:** Triggers transition from State 7.1 Wait to State 6.1 Wait. +- S-REL IND/RESP:** Triggers transitions in State 6.1 Wait. +- S-CON IND/RESP/NEG:** Triggers transitions in State 1.1 Wait. +- S-CTRL GIVE CONF/REQ/IND/RESP:** Triggers transitions in States 2, 3, 4, and 3.1. +- S-U-ABT IND/CONF/REQ/RESP:** Triggers transitions in States 7, 0.1, and 0.2. +- T-EXPT IND:** Triggers transitions in States 7, 0.1, 0.2, and 14.1. +- T-CON IND/RESP:** Triggers transitions in State 0.1. +- T-DISC IND/REQ:** Triggers transitions in State 0.1. +- Start T1/T2/T3:** Triggers transitions in various states. +- Stop T1/T2/T3:** Triggers transitions in various states. +- Discard:** Triggers transitions in States 7 and 14.1. +- Wait:** Triggers transitions in States 7.1, 6.1, 1.1, 5.1, 3.1, and 14.1. + +**Legend:** + +- T1 Inactivity timer +- T2 Demand response timer +- T3 CSA timer + +**NOTE** – With or without transport release bit set. + +Teletex session state transition diagram (called side) showing various states and transitions between them. + +FIGURE G.2/T.62 +Teletex session state transition diagram (called side) + +![Teletex document state transition diagram (sending protocol)](7e14467740b2570a44379b347a697921_img.jpg) + +The diagram illustrates the state transitions for a Teletex document sending protocol. Major states include: + +- DS 1:** Central state with sub-state DS 1.1 Wait. Handles S-ACT, S-CAPAB, and S-SYNC transitions. +- DS 2:** Sub-state DS 2.1 Wait. Involves S-SYNC MIN CONF and R-RSUI/RDPBP(K) logic. +- DS 3:** Sub-state DS 3.1 Wait. Involves S-SYNC MIN CONF and S-ACT END REQ logic. +- DS 4:** Sub-state DS 4.1 Wait. Transitioned to via S-CSUI/CDPB (I). +- DS 5:** Sub-state DS 5.1 Wait. Involves R = R + 1 logic and RESTART T2. +- DS 6:** Sub-state DS 6.1 Wait. Involves Start T2 and R-RSUI/RDCLP. +- DS 7:** Sub-state DS 7.1 Wait. Involves S-U-EXPT IND and S-P-EXPT (ERR) IND. +- DS 8:** Sub-state DS 8.1 Wait. Involves Start T2 and Discard logic. +- DS 9:** Sub-state DS 9.1 Wait. Involves Start T2 and Discard logic. + +Transitions are triggered by events such as S-ACT (Session Activity), R-RSUI (Receive Response), and timer T2 events. Logic within states often updates variables S (next checkpoint) and R (next expected checkpoint acknowledgement). + +Teletex document state transition diagram (sending protocol) + +S Number of next checkpoint + R Number of next expected checkpoint acknowledgement + I Actual checkpoint number (in CDPB and CDE) + K Actual checkpoint acknowledgement number (in RDPBP and RDEP) + C Checkpoint number from which the sender wishes to start + W Window size + T2 Demand response timer + +FIGURE G.3/T.62 + +**Teletex document state transition diagram (sending protocol)** + +58 **Recommendation T.62 (03/93)** + +![Teletex document state transition diagram (receiving protocol) showing states DR 1 through DR 9 and transitions between them based on various events and actions.](5a9cdc1fed33ae8fb871a8cd4d591729_img.jpg) + +The diagram illustrates the state transitions for the receiving protocol in a teletex document. It features nine states, labeled DR 1 through DR 9, each containing specific actions and timers. Transitions between these states are triggered by various events and actions, such as receiving a PDU, sending a response, or receiving a synchronization message. + +**Legend:** + +- P: Number of next checkpoint +- Q: Number of next expected checkpoint acknowledgement +- I: Actual checkpoint number (in CDPB and CDE) +- K: Actual checkpoint acknowledgement number (in RDPBP and RDEP) +- C: Checkpoint number from which the sender wishes to start +- W: Window size +- \*: This primitive shall carry an error parameter if $I \neq P$ (sequence error) +- T1: Inactivity timer + +**States and Transitions:** + +- DR 1:** Contains 'Start T1'. Transitions include 'R-CSUI/CDD' to DR 9, 'R-CSUI/CDCL' to DR 6, 'R-CSUI/CDC(C)' to DR 2, 'R-CSUI/CDU(I)' to DR 3, and 'R-CSUI/CDU(I) and $(P - Q) = (W - 1)$ ' to DR 4. +- DR 2:** Contains 'S-ACT BEG (CONT) IND $P = Q = C + 1$ ', 'S-ACT BEG (STR) IND $P = Q = 1$ ', 'DR 2.1 Wait', '\* S-SYNC MIN IND $P = P + 1$ Restart T1', and 'Q = Q + 1 Restart T1'. Transitions include 'S-SYNC MIN RESP' to DR 5, 'S-RSUI/RDPBP(K) and $P > Q$ ' to DR 3, and 'S-RSUI/RDPBP(K) and $P > Q$ ' to DR 4. +- DR 3:** Contains 'S-DATA IND Restart T1', 'Q = Q + 1 Restart T1', 'S-DATA IND Restart T1', and 'DR 3.1 Wait'. Transitions include 'S-SYNC MIN RESP' to DR 5, 'S-RSUI/RDPBP(K) and $P > Q$ ' to DR 4, and 'R-CSUI/CDU(I) and $(P - Q) = (W - 1)$ ' to DR 4. +- DR 4:** Contains '\* S-SYNC MIN IND $P = P + 1$ Stop T1' and 'DR 4.1 Wait'. Transitions include 'S-SYNC MIN RESP' to DR 5 and 'S-RSUI/RDPBP(K) and $P > Q$ ' to DR 3. +- DR 5:** Contains 'DR 5.1 Wait', 'Q = Q + 1', and '\* S-ACT END IND Stop T1'. Transitions include 'S-SYNC MIN RESP' to DR 2, 'S-RSUI/RDPBP(K) and $P > Q$ ' to DR 3, and 'S-RSUI/RDPBP(K) and $P > Q$ ' to DR 4. +- DR 6:** Contains 'S-CAPAB DATA IND Stop T1', 'DR 6.1 Wait', and 'S-CAPAB DATA RESP'. Transitions include 'S-RSUI/RDCLP' to DR 1 and 'S-RSUI/RDCLP' to DR 2. +- DR 7:** Contains 'Start T1', 'DR 7.1 Wait', and 'Discard'. Transitions include 'R-CSUI/CDR' to DR 1, 'R-CSUI/CDR' to DR 8, and 'R-CSUI/CDR' to DR 9. +- DR 8:** Contains 'S-ACT INT IND', 'Stop T1', 'S-ACT INT RESP', and 'DR 8.1 Wait'. Transitions include 'S-RSUI/RDRP' to DR 1 and 'S-RSUI/RDRP' to DR 2. +- DR 9:** Contains 'S-ACT DCAD IND', 'S-ACT DCAD RESP', 'Stop T1', and 'DR 9.1 Wait'. Transitions include 'R-CSUI/CDD' to DR 1, 'R-CSUI/CDD' to DR 7, and 'R-CSUI/CDD' to DR 8. + +Teletex document state transition diagram (receiving protocol) showing states DR 1 through DR 9 and transitions between them based on various events and actions. + +FIGURE G.4/T.62 +Teletex document state transition diagram (receiving protocol) + +# Annex H + +## State transition tables for session/document procedures + +(This annex forms an integral part of this Recommendation) + +## H.1 General + +This annex provides state transition tables for session/document procedures for the basic services. + +## H.2 Notation details + +### H.2.1 Timers + +**H.2.1.1** The following timers are used in the state tables: + +- a) *Timer T1* – Inactivity timer, value as determined by inactivity timer value negotiation. +- b) *Timer T2* – Demand response timer, value 60 seconds. +- c) *Timer T3* – CSA timer of, for example, 4 seconds. + +### H.2.2 Notes + +**H.2.2.1** Several actions described in the state tables are marked by a number which relates to the following notes: + +- 1) only if T-DISC is not required; +- 2) ——— [see H.2.3.2 h) below]; +- 3) alternative error recovery mechanism; +- 4) this may also be considered as an error; +- 5) S-SYNC MIN ind with parameter “procedural error”; +- 6) S-SYNC MIN ind with parameter “sequence error”; +- 7) only if the reuse of the transport connection is intended. + +### H.2.3 Symbols + +**H.2.3.1** For the description of several different conditions Boolean equations and symbols are used. + +**H.2.3.2** The symbols have the following meanings: + +- a) < less than; +- b) > greater than; +- c) = equal; +- d) ≠ not equal; +- e) ∨ or; +- f) ∧ and; +- g) ¬ not; +- h) ——— event irrelevant in this specific state since error free operation of the considered terminal is assumed. + +### H.2.4 Counters + +**H.2.4.1** For the description of the dynamic behaviour of parameters such as checkpoint numbers, several counters and parameter abbreviations are introduced. + +**H.2.4.2** Counters of the source are as follows: + +- a) S – This indicates the next allowed checkpoint reference number for a CDPB or CDE. +- b) R – This indicates the next expected checkpoint reference number in an RDPBP or RDEP. + +**H.2.4.3** Counters of the sink are as follows: + +- a) P – This indicates the next expected checkpoint reference number in a CDPB or CDE to be acknowledged by the sink. +- b) Q – This indicates the next allowed checkpoint reference number to be acknowledged in an RDPBP or RDEP. + +**H.2.4.4** Parameter abbreviations are as follows: + +- a) C – A checkpoint reference number from which the source will resume transmission (in case of continuation with CDC). +- b) I – An actual checkpoint reference number in a CDPB or CDE. +- c) K – An actual checkpoint reference number to be acknowledged in an RDPBP or RDEP. +- d) W – Acknowledgement window size. + +### **H.2.5 Abbreviations** + +**H.2.5.1** The abbreviations contained in Table G.1 apply to the description of service primitives. + +## **H.3 State tables** + +**H.3.1** State tables for a calling terminal is shown in Table H.1. + +**H.3.2** State tables for a called terminal is shown in Table H.2. + +TABLE H.1/T.62 +State transition tables for calling terminal + +Calling terminal + +| State | | | Idle | | | | | | | | | | | | Wait | | | | +|-------------|----------------|---------------------|---------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------| +| Event | | | 0.1 | | | | 0.2 | | | | 0.3 | | | | 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CON REQ | | | T-CON REQ | 0.3 | START T2 | S-CSS | | 8.1 | (-----) | | | | (-----) | | | | +| | | S-REL REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CTRL GIVE REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CTRL GIVE RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-SYNC MIN REQ (I) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-SYNC MIN RESP (K) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-U-EXPT REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT END REQ (I) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT END RESP (K) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-U-ABT REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | Idle | | | | | | | | | | | | Wait | | | | | +|-------------|----------------|--------------------------|---------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------|--| +| Event | | | 0.1 | | | | 0.2 | | | | 0.3 | | | | 7.1 | | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | | +| | | S-U-ABT RESP | (-----) | | | | (-----) | | | | (-----) | | | | | S-RSAP | T-DISCON REQ | 0.1 | | +| | | | | | | | | | | | | | | | | | — 1) | 0.2 | | +| | | S-ACT BEG (START) REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-ACT BEG (CONT) REQ (C) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-ACT DCAD REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-ACT DCAD RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-ACT INT REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-ACT INT RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-CAPAB DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| Event | | | State | | | | | | | | | | | | | | | | +|-------------|----------------|-------------------|-------|-----------------|-------------------|-------------|-------|-----------------|-------------------|-------------|----------|-----------------|--------------------------------|-------------|-------|-----------------|-------------------|-------------| +| | | | Idle | | | | | | | | | | | | Wait | | | | +| | | | 0.1 | | | | 0.2 | | | | 0.3 | | | | 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CAPAB DATA RESP | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | T-CON CONF | ( ) | | | | ( ) | | | | START T2 | S-CSS | | 8.1 | ( ) | | | | +| | | T-DISCON IND | ( ) | | | | | | | 0.1 | | | S-CON CONF NEG | 0.1 | | | S-P-ABT IND | 0.1 | +| | | T-EXPT IND | ( ) | | | | | | T-DISCON REQ | 0.1 | | | T-DISCON REQ<br>S-CON CONF NEG | 0.1 | | | | 7.1 | +| | R-CSS | | ( ) | | | | | | T-DISCON REQ | 0.1 | ( ) | | | | | | | 7.1 | +| | R-RSSP | | ( ) | | | | | | T-DISCON REQ | 0.1 | ( ) | | | | | | | 7.1 | +| | R-RSSN | | ( ) | | | | | | T-DISCON REQ | 0.1 | ( ) | | | | | | | 7.1 | +| | R-CSE | | ( ) | | | | | | T-DISCON REQ | 0.1 | ( ) | | | | | | | 7.1 | +| | R-RSEP | | ( ) | | | | | | T-DISCON REQ | 0.1 | ( ) | | | | | | | 7.1 | +| | R-CSA | | ( ) | | | | | | T-DISCON REQ | 0.1 | ( ) | | | | | | | 7.1 | +| | R-RSAP | | ( ) | | | | | | T-DISCON REQ | 0.1 | ( ) | | | | | | | 7.1 | +| | R-CSCC | | ( ) | | | | | | T-DISCON REQ | 0.1 | ( ) | | | | | | | 7.1 | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | Idle | | | | | | | | | | | | Wait | | | | +|-------------|-----------------|-------------------|---------|-----------------|-------------------|-------------|-------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------|-------|-----------------|-------------------|-------------| +| Event | | | 0.1 | | | | 0.2 | | | | 0.3 | | | | 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-RSCCP | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | +| | R-CSUI/CDS | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | +| | R-CSUI/CDC (C) | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | +| | R-CSUI/CDCL | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | +| | R-RSUI/RDCLP | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | +| | R-CSUI/CDE (I) | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | +| | R-RSUI/RDEP (K) | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | +| | R-CSUI/CDD | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | +| | R-RSUI/RDDP | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | +| | R-CSUI/CDR | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | +| | R-RSUI/RDRP | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | +| | R-CSUI/CDUI | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | +| | R-RSUI/RDGR | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | Idle | | | | | | | | | | | | Wait | | | | +|--------------|-------------------------------------------|-------------------|---------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------| +| Event | | | 0.1 | | | | 0.2 | | | | 0.3 | | | | 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/CDPB (I) | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | +| | R-RSUI/RDPBP (K) | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | +| | R-RSUI/RDPBN | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | +| | ANY OTHER COMMAND OR RESP OR WRONG FORMAT | | (-----) | | | | | | T-DISCON REQ | 0.1 | (-----) | | | | | | | 7.1 | +| EXPIRY OF T1 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| EXPIRY OF T2 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| EXPIRY OF T3 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| Event | | | State | | | | | | | | | | | | | | | | +|-------------|----------------|----------------------------------------------------------------|-------|-----------------|-------------------|-------------|-----------------|-----------------|-------------------|-------------|--------|-----------------|-------------------|-------------|----------|--------------------------------|-------------------|-------------| +| | | | Wait | | | | 9 Document send | | | | | | | | | | | | +| | | | 8.1 | | | | DS 1.1 | | | | DS 2.1 | | | | DS 3.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CON REQ | | | | | | | | | | | | | | | | | +| | | S-REL REQ | | | | | START T2 | S-CSE | | 13.1 | | | | | | | | | +| | | S-CTRL GIVE REQ | | | | | START T2 | S-CSCC | | 10.1 | | | | | | | | | +| | | S-CTRL GIVE RESP | | | | | | | | | | | | | | | | | +| | | S-SYNC MIN REQ (I)<br>$\wedge (S-R) < (W-1)$<br>$\wedge I = S$ | | | | | | | | | | | | | START T2 | S-CSUI/CDPB (I)<br>$S = S + 1$ | | DS 2.1 | +| | | S-SYNC MIN REQ (I)<br>$\wedge (S-R) = (W-1)$<br>$\wedge I = S$ | | | | | | | | | | | | | START T2 | S-CSUI/CDPB (I)<br>$S = S + 1$ | | DS 4.1 | +| | | S-SYNC MIN RESP (K) | | | | | | | | | | | | | | | | | +| | | S-U-EXPT REQ | | | | | | | | | | | | | | | | | +| | | S-ACT END REQ (I) | | | | | | | | | | | | | START T2 | S-CSUI/CDE (I) | | DS 5.1 | + +TABLE H.1/T.62 (continued) +**State transition tables for calling terminal** + +Calling terminal + +| State | | | Wait | | | | 9 Document send | | | | | | | | | | | | +|-------------|----------------|-----------------------------------|-------------|-----------------|-------------------|-------------|-----------------|----------------------------------------|-------------------|-------------|-------------|-----------------|-------------------|-------------|-------------|-----------------|-------------------|-------------| +| | | | 8.1 | | | | DS 1.1 | | | | DS 2.1 | | | | DS 3.1 | | | | +| Event | | | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| Local event | Protocol event | Service primitive | | | | | | | | | | | | | | | | | +| | | S-ACT<br>END<br>RESP (K) | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-U-ABT<br>REQ | START<br>T3 | S-CSA | | 14.1 | START<br>T3 | S-CSA | | 14.1 | START<br>T3 | S-CSA | | 14.1 | START<br>T3 | S-CSA | | 14.1 | +| | | S-U-ABT<br>RESP | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT<br>BEG<br>(START)<br>REQ | ( ) | | | | | S-CSUI/<br>CDS<br>S = R = 1 | | DS 2.1 | ( ) | | | | ( ) | | | | +| | | S-ACT<br>BEG<br>(CONT)<br>REQ (C) | ( ) | | | | | S-CSUI/<br>CDC (C)<br>S = R =<br>C + 1 | | DS 2.1 | ( ) | | | | ( ) | | | | +| | | S-DATA<br>REQ | ( ) | | | | ( ) | | | | | S-CSUI/<br>CDUI | | DS 3.1 | | S-CSUI/<br>CDUI | | DS 3.1 | +| | | S-ACT<br>DCAD<br>REQ | ( ) | | | | ( ) | | | | START<br>T2 | S-CSUI/<br>CDD | | DS 9.1 | START<br>T2 | S-CSUI/<br>CDD | | DS 9.1 | +| | | S-ACT<br>DCAD<br>RESP | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT<br>INT<br>REQ | ( ) | | | | ( ) | | | | START<br>T2 | S-CSUI/<br>CDR | | DS 8.1 | START<br>T2 | S-CSUI/<br>CDR | | DS 8.1 | +| | | S-ACT<br>INT<br>RESP | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | Wait | | | | 9 Document send | | | | | | | | | | | | +|-------------|----------------|-------------------|---------|-----------------|--------------------------------|-------------|-----------------|-----------------|---------------------|-------------|---------|-----------------|-----------------------|-------------|---------|-----------------|-----------------------|-------------| +| Event | | | 8.1 | | | | DS 1.1 | | | | DS 2.1 | | | | DS 3.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CAPAB DATA REQ | (-----) | | | | START T2 | S-CSUI/ CDCL | | DS 6.1 | (-----) | | | | (-----) | | | | +| | | S-CAPAB DATA RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | T-CON CONF | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | T-DISCON IND | STOP T2 | | S-P-ABT IND | 0.1 | | | S-P-ABT IND | 0.1 | STOP T2 | | S-P-ABT IND | 0.1 | STOP T2 | | S-P-ABT IND | 0.1 | +| | | T-EXPT IND | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSS | | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSSP | | STOP T2 | | S-CON CONF | DS 1.1 | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSSN | | STOP T2 | | T-DISCON REQ<br>S-CON CONF NEG | 0.1 | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSE | | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | Wait | | | | 9 Document send | | | | | | | | | | | | +|-------------|-----------------|-------------------|---------|-----------------|---------------------|-------------|-----------------|-----------------|---------------------|-------------|---------|-----------------|-----------------------|-------------|---------|-----------------|-----------------------|-------------| +| Event | | | 8.1 | | | | DS 1.1 | | | | DS 2.1 | | | | DS 3.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-RSEP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSA | | STOP T2 | | S-ABT IND | 7.1 | | | S-ABT IND | 7.1 | STOP T2 | | S-ABT IND | 7.1 | STOP T2 | | S-ABT IND | 7.1 | +| | R-RSAP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSCC | | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSCCP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDS | | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDC (C) | | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDCL | | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/ RDCLP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | + +TABLE H.1/T.62 (*continued*) +**State transition tables for calling terminal** + +Calling terminal + +| State | | | Wait | | | | 9 Document send | | | | | | | | | | | | +|-------------|---------------------------------------|-------------------|------------|-----------------|---------------------------|-------------|-----------------|-----------------|---------------------------|-------------|------------|-----------------|-----------------------------|-------------|------------|-----------------|-----------------------------|-------------| +| Event | | | 8.1 | | | | DS 1.1 | | | | DS 2.1 | | | | DS 3.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/<br>CDE (I) | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDEP (K)<br>$\wedge$ K = R | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDD | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDDP | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDR | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDRP | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | + +TABLE H.1/T.62 (continued) +**State transition tables for calling terminal** + +Calling terminal + +| Event | | | State | | | | | | | | | | | | | | | | +|-------------|-----------------------------------------------------------------|-------------------|------------|-----------------|---------------------------|-------------|-----------------|-----------------|---------------------------|-------------|---------------|-----------------|-----------------------------------|-------------|---------------|-----------------|-----------------------------------|-------------| +| | | | Wait | | | | 9 Document send | | | | | | | | | | | | +| | | | 8.1 | | | | DS 1.1 | | | | DS 2.1 | | | | DS 3.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/<br>CDUI | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDGR | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDPB (1) | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDPBP<br>(K)<br>$\wedge K = R$<br>$\wedge S > R$ | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | RESTART<br>T2 | | S-SYNC<br>MIN CONF<br>$R = R + 1$ | DS 2.1 | RESTART<br>T2 | | S-SYNC<br>MIN CONF<br>$R = R + 1$ | DS 3.1 | +| | R-RSUI/<br>RDPBP<br>(K)<br>$\wedge K = R$<br>$\wedge S = R + 1$ | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-SYNC<br>MIN CONF<br>$R = R + 1$ | DS 2.1 | STOP<br>T2 | | S-SYNC<br>MIN CONF<br>$R = R + 1$ | DS 3.1 | +| | R-RSUI/<br>RDPBN | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-U-EXPT<br>IND 3) | DS 7.1 | STOP<br>T2 | | S-U-EXPT<br>IND 3) | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | + +TABLE H.1/T.62 (continued) +**State transition tables for calling terminal** + +Calling terminal + +| State | | | Wait | | | | 9 Document send | | | | | | | | | | | | +|--------------|-----------------------------------------------------------------------------|-------------------|---------|-----------------|---------------------|-------------|-----------------|-----------------|---------------------|-------------|---------|-----------------|----------------------|-------------|---------|-----------------|----------------------|-------------| +| Event | | | 8.1 | | | | DS 1.1 | | | | DS 2.1 | | | | DS 3.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | ANY OTHER DOCUMENT COMMAND OR RESP. OR WRONG FORMAT IN CONNECTION WITH RSUI | | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (ERR) 3 | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3 | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | ANY OTHER COMMAND OR RESP. OR WRONG FORMAT | | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| EXPIRY OF T1 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| EXPIRY OF T2 | | | STOP T2 | | S-P-EXPT IND (FAIL) | x | (-----) | | | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| EXPIRY OF T3 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 9 Document send | | | | | | | | | | | | | | | | +|-------------|----------------|---------------------|-----------------|-----------------|-------------------|-------------|-------------|-----------------|-------------------|-------------|-------------|-----------------|-------------------|-------------|-------------|-----------------|-------------------|-------------| +| Event | | | DS 4.1 | | | | DS 5.1 | | | | DS 6.1 | | | | DS 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CON REQ | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-REL REQ | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-CTRL GIVE REQ | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-CTRL GIVE RESP | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-SYNC MIN REQ (I) | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-SYNC MIN RESP (K) | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-U-EXPT REQ | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-ACT END REQ (I) | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-ACT END RESP (K) | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-U-ABT REQ | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | +| | | S-U-ABT RESP | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 9 Document send | | | | | | | | | | | | | | | | +|-------------|----------------|--------------------------|-----------------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------| +| Event | | | DS 4.1 | | | | DS 5.1 | | | | DS 6.1 | | | | DS 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-ACT BEG (START) REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT BEG (CONT) REQ (C) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT DCAD REQ | START T2 | S-CSUI/ CDD | | DS 9.1 | START T2 | S-CSUI/ CDD | | DS 9.1 | (-----) | | | | START T2 | S-CSUI/ CDD | | DS 9.1 | +| | | S-ACT DCAD RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT INT REQ | START T2 | S-CSUI/ CDR | | DS 8.1 | START T2 | S-CSUI/ CDR | | DS 8.1 | START T2 | S-CSUI/ CDR | | DS 8.1 | START T2 | S-CSUI/ CDR | | DS 8.1 | +| | | S-ACT INT RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CAPAB DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CAPAB DATA RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | T-CON CONF | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 9 Document send | | | | | | | | | | | | | | | | +|-------------|----------------|-------------------|-----------------|-----------------|-----------------------|-------------|---------|-----------------|-----------------------|-------------|---------|-----------------|-----------------------|-------------|--------|-----------------|---------------------|-------------| +| Event | | | DS 4.1 | | | | DS 5.1 | | | | DS 6.1 | | | | DS 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | T-DISCON IND | STOP T2 | | S-P-ABT IND | 0.1 | STOP T2 | | S-P-ABT IND | 0.1 | STOP T2 | | S-P-ABT IND | 0.1 | | | S-P-ABT IND | 0.1 | +| | | T-EXPT IND | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | | | | DS 7.1 | +| | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSS | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSSP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSSN | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSE | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSEP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSA | | STOP T2 | | S-ABT IND | 7.1 | STOP T2 | | S-ABT IND | 7.1 | STOP T2 | | S-ABT IND | 7.1 | | | S-ABT IND | 7.1 | +| | R-RSAP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 9 Document send | | | | | | | | | | | | | | | | +|-------------|--------------------------|-------------------|-----------------|-----------------|-----------------------|-------------|---------|-----------------|-----------------------|-------------|---------|-----------------|-----------------------|-------------|--------|-----------------|---------------------|-------------| +| Event | | | DS 4.1 | | | | DS 5.1 | | | | DS 6.1 | | | | DS 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSCC | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSCCP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDS | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDC (C) | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDCL | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/ RDCLP | | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | STOP T2 | | S-CAPAB DATA CONF | DS 1.1 | | | | DS 7.1 | +| | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | | | | | | +| | R-CSUI/ CDE (I) | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/ RDEP (K) ^ K = R | | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | STOP T2 | | S-ACT END CONF | DS 1.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | | | | DS 7.1 | +| | | | | | S-P-EXPT IND (FAIL) | x | | | | | | | S-P-EXPT IND (FAIL) | x | | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 9 Document send | | | | | | | | | | | | | | | | +|-------------|-----------------|-------------------|-----------------|-----------------|-----------------------------|-------------|------------|-----------------|-----------------------------|-------------|------------|-----------------|-----------------------------|-------------|--------|-----------------|---------------------------|-------------| +| Event | | | DS 4.1 | | | | DS 5.1 | | | | DS 6.1 | | | | DS 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/<br>CDD | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDDP | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | | | | DS 7.1 | +| | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | | +| | R-CSUI/<br>CDR | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDRP | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | | | | DS 7.1 | +| | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | | +| | R-CSUI/<br>CDUI | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDGR | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | | | | DS 7.1 | +| | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| Event | | | State | | | 9 Document send | | | | | | | | | | | | | | | | +|-------------|-------------------------------------------------------------------------------------------|-------------------|------------|-----------------|--------------------------------------|-----------------|---------------|-----------------|--------------------------------------|-------------|------------|-----------------|-----------------------------|-------------|--------|-----------------|---------------------------|-------------|--|--|--| +| | | | DS 4.1 | | | | DS 5.1 | | | | DS 6.1 | | | | DS 7.1 | | | | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | | | | +| | R-CSUI/<br>CDPB (I) | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | +| | R-RSUI/<br>RDPBP<br>(K)<br>$\wedge K = R$<br>$\wedge S > R$ | | | | S-SYNC<br>MIN<br>CONF<br>$R = R + 1$ | DS 2.1 | RESTART<br>T2 | | S-SYNC<br>MIN<br>CONF<br>$R = R + 1$ | DS 5.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | | | | DS 7.1 | | | | +| | | | | | | | | | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | | | | | +| | R RSUI/<br>RDPBP<br>(K)<br>$\wedge K = R$<br>$\wedge S = R + 1$ | | STOP<br>T2 | | S-SYNC<br>MIN<br>CONF<br>$R = R + 1$ | DS 2.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | | | | | | | | +| | | | | | | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | | | | | +| | R-RSUI/<br>RDPBN | | STOP<br>T2 | | S-U-EXPT<br>IND 3) | DS 7.1 | STOP<br>T2 | | S-U-EXPT<br>IND 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | | | | | | | | +| | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | | | | | +| | ANY OTHER<br>COMMAND<br>OR RESP.<br>OR WRONG<br>FORMAT<br>IN CON-<br>NECTION<br>WITH RSUI | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | | | | | | | | +| | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | | | | | + +TABLE H.1/T.62 (continued) +**State transition tables for calling terminal** + +Calling terminal + +| State | | | 9 Document send | | | | | | | | | | | | | | | | +|--------------|--------------------------------------------|-------------------|-----------------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------| +| Event | | | DS 4.1 | | | | DS 5.1 | | | | DS 6.1 | | | | DS 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | ANY OTHER COMMAND OR RESP. OR WRONG FORMAT | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| EXPIRY OF T1 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| EXPIRY OF T2 | | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | (-----) | | | | +| EXPIRY OF T3 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 9 Document send | | | | | | | | Wait | | | | +|-------------|----------------|---------------------------------------|-----------------|-----------------|-------------------|-------------|-------------|-----------------|-------------------|-------------|-------------|-----------------|-------------------|-------------| +| Event | | | DS 8.1 | | | | DS 9.1 | | | | 10.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CON REQ | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-REL REQ | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-CTRL GIVE REQ | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-CTRL GIVE RESP | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-SYNC MIN REQ (I) | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-SYNC MIN RESP (K)<br>$\wedge K = Q$ | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-U-EXPT REQ | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-ACT END REQ (I) | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-ACT END RESP (K) | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-U-ABT REQ | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | +| | | S-U-ABT RESP | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 9 Document send | | | | | | | | Wait | | | | +|-------------|----------------|--------------------------|-----------------|-----------------|-------------------|-------------|-------------|-----------------|-------------------|-------------|-------------|-----------------|-------------------|-------------| +| Event | | | DS 8.1 | | | | DS 9.1 | | | | 10.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-ACT BEG (START) REQ | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-ACT BEG (CONT) REQ (C) | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-DATA REQ | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-ACT DCAD REQ | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-ACT DCAD RESP | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-ACT INT REQ | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-ACT INT RESP | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-CAPAB DATA REQ | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | S-CAPAB DATA RESP | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | T-CON CONF | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | T-DISCON IND | STOP T2 | | S-P-ABT IND | 0.1 | STOP T2 | | S-P-ABT IND | 0.1 | STOP T2 | | S-P-ABT IND | 0.1 | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| Event | | | State 9 Document send | | | | | | | | Wait | | | | +|-------------|----------------|-------------------|-----------------------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------| +| | | | DS 8.1 | | | | DS 9.1 | | | | 10.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | T-EXPT IND | | | | DS 8.1 | | | | DS 9.1 | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | | | +| | R-CSS | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSSP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSSN | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSE | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSEP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSA | | STOP T2 | | S-ABT IND | 7.1 | STOP T2 | | S-ABT IND | 7.1 | STOP T2 | | S-ABT IND | 7.1 | +| | R-RSAP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSCC | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 9 Document send | | | | | | | | Wait | | | | +|-------------|------------------|-------------------|-----------------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------|---------------------|-----------------|---------------------|-------------| +| Event | | | DS 8.1 | | | | DS 9.1 | | | | 10.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-RSCCP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2<br>START T1 | | S-CTRL GIVE CONF | DR 1.1 | +| | R-CSUI/ CDS | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDC (C) | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDCL | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/ RDCLP | | | | | DS 8.1 | | | | DS 9.1 | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDE (I) | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/ RDEP (K) | | | | | DS 8.1 | | | | DS 9.1 | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDD | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/ RDDP | | | | | DS 8.1 | STOP T2 | | S-ACT DCAD CONF | DS 1.1 | STOP T2 | | S-P-EXPT IND (FAIL) | x | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 9 Document send | | | | | | | | Wait | | | | +|-------------|-----------------------------------------------------------------------------|-------------------|-----------------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------| +| Event | | | DS 8.1 | | | | DS 9.1 | | | | 10.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/CDR | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/RDRP | | STOP T2 | | S-ACT INT CONF | DS 1.1 | | | | DS 9.1 | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/CDUI | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/RDGR | | | | | DS 8.1 | | | | DS 9.1 | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/CDPB (I) | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/RDPBP (K) | | | | | DS 8.1 | | | | DS 9.1 | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/RDPBN | | | | | DS 8.1 | | | | DS 9.1 | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | ANY OTHER DOCUMENT COMMAND OR RESP. OR WRONG FORMAT IN CONNECTION WITH RSUI | | | | | DS 8.1 | | | | DS 9.1 | STOP T2 | | S-P-EXPT IND (FAIL) | x | + +TABLE H.1/T.62 (continued) +**State transition tables for calling terminal** + +Calling terminal + +| State | | | 9 Document send | | | | | | | | Wait | | | | +|--------------|--------------------------------------------|-------------------|-----------------|-----------------|---------------------|-------------|-------------|-----------------|---------------------|-------------|-------------|-----------------|---------------------|-------------| +| Event | | | DS 8.1 | | | | DS 9.1 | | | | 10.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | ANY OTHER COMMAND OR RESP. OR WRONG FORMAT | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| EXPIRY OF T1 | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| EXPIRY OF T2 | | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| EXPIRY OF T3 | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | + +TABLE H.1/T.62 (continued) +**State transition tables for calling terminal** + +Calling terminal + +| Event | | | State | | | | | | | | | | | | | | | | +|-------------|----------------|---------------------------------------|---------------------|-----------------|-------------------|-------------|------------|-------------------|--------------------|-------------|------------|-------------------|--------------------|-------------|----------|-------------------|--------------------|-------------| +| | | | 11 Document receive | | | | | | | | | | | | | | | | +| | | | DR 1.1 | | | | DR 2.1 | | | | DR 3.1 | | | | DR 4.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CON REQ | | | | | | | | | | | | | | | | | +| | | S-REL REQ | | | | | | | | | | | | | | | | | +| | | S-CTRL GIVE REQ | | | | | | | | | | | | | | | | | +| | | S-CTRL GIVE RESP | | | | | | | | | | | | | | | | | +| | | S-SYNC MIN REQ (I) | | | | | | | | | | | | | | | | | +| | | S-SYNC MIN RESP (K)<br>$\wedge K = Q$ | | | | | RESTART T1 | S-RSUI/ RDPBP (K) | COUNTER: Q = Q + 1 | DR 2.1 | RESTART T1 | S-RSUI/ RDPBP (K) | COUNTER: Q = Q + 1 | DR 3.1 | START T1 | S-RSUI/ RDPBP (K) | COUNTER: Q = Q + 1 | DR 2.1 | +| | | S-U-EXPT REQ | | | | | RESTART T1 | S-RSUI/ RDPBN | | DR 7.1 | RESTART T1 | S-RSUI/ RDPBN | | DR 7.1 | START T1 | S-RSUI/ RDPBN | | DR 7.1 | +| | | S-ACT END REQ (I) | | | | | | | | | | | | | | | | | +| | | S-ACT END RESP (K) | | | | | | | | | | | | | | | | | +| | | S-U-ABT REQ | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| Event | | | State | | | | | | | | | | | | | | | | +|-------------|----------------|-----------------------------------|---------------------|-----------------|-------------------|-------------|--------|-----------------|-------------------|-------------|--------|-----------------|-------------------|-------------|--------|-----------------|-------------------|-------------| +| | | | 11 Document receive | | | | | | | | | | | | | | | | +| | | | DR 1.1 | | | | DR 2.1 | | | | DR 3.1 | | | | DR 4.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-U-ABT<br>RESP | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT<br>BEG<br>(START)<br>REQ | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT<br>BEG<br>(CONT)<br>REQ (C) | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-DATA<br>REQ | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT<br>DCAD<br>REQ | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT<br>DCAD<br>RESP | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT<br>INT<br>REQ | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT<br>INT<br>RESP | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-CAPAB<br>DATA<br>REQ | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 11 Document receive | | | | | | | | | | | | | | | | +|-------------|----------------|-------------------|---------------------|-----------------|----------------------|-------------|---------|-----------------|----------------------|-------------|---------|-----------------|----------------------|-------------|---------|-----------------|----------------------|-------------| +| Event | | | DR 1.1 | | | | DR 2.1 | | | | DR 3.1 | | | | DR 4.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CAPAB DATA RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | T-CON CONF | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | T-DISCON IND | STOP T1 | | S-P-ABT IND | 0.1 | STOP T1 | | S-P-ABT IND | 0.1 | STOP T1 | | S-P-ABT IND | 0.1 | | | S-P-ABT IND | 0.1 | +| | | T-EXPT IND | | | S-P-EXPT IND (ERR) 3 | DR 1.1 | | | S-P-EXPT IND (ERR) 3 | DR 2.1 | | | S-P-EXPT IND (ERR) 3 | DR 3.1 | | | S-P-EXPT IND (ERR) 3 | DR 4.1 | +| | | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSS | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSSP | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSSN | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSE | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSEP | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 11 Document receive | | | | | | | | | | | | | | | | +|-------------|-----------------|-------------------|---------------------|-----------------|-----------------------------------|-------------|------------|-----------------|-----------------------|-------------|------------|-----------------|-----------------------|-------------|----------|-----------------|-----------------------|-------------| +| Event | | | DR 1.1 | | | | DR 2.1 | | | | DR 3.1 | | | | DR 4.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSA | | STOP T1 | | S-ABT IND | 7.1 | STOP T1 | | S-ABT IND | 7.1 | STOP T1 | | S-ABT IND | 7.1 | | | S-ABT IND | 7.1 | +| | R-RSAP | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSCC | | STOP T1 | | S-CTRL GIVE IND | 12.1 | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSCCP | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDS | | RESTART T1 | | S-ACT (START) IND<br>P = Q = 1 | DR 2.1 | RESTART T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | RESTART T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | START T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | +| | | | | | | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDC (C) | | RESTART T1 | | S-ACT (CONT) IND<br>P = Q = C + 1 | DR 2.1 | RESTART T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | RESTART T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | START T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | +| | | | | | | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDCL | | STOP T1 | | S-CAPAB DATA IND | DR 6.1 | RESTART T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | RESTART T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | START T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | +| | | | | | | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 11 Document receive | | | | | | | | | | | | | | | | +|-------------|-------------------------------------------------------------------|-------------------|---------------------|-----------------|-----------------------------|-------------|---------------|-----------------|-----------------------------|-------------|---------------|-----------------|---------------------------|-------------|-------------|-----------------|-----------------------------|-------------| +| Event | | | DR 1.1 | | | | DR 2.1 | | | | DR 3.1 | | | | DR 4.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-RSUI/<br>RDCLP | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R CSUI/<br>CDE (I)<br>$\wedge (P-Q) \leq (W-1)$<br>$\wedge I = P$ | | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | STOP<br>T1 | | S-ACT<br>END IND | DR 5.1 | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | +| | | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDEP (K) | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDD | | STOP<br>T1 | | S-ACT<br>DCAD<br>IND | DR 9.1 | STOP<br>T1 | | S-ACT<br>DCAD<br>IND | DR 9.1 | STOP<br>T1 | | S-ACT<br>DCAD<br>IND | DR 9.1 | | | S-ACT<br>DCAD<br>IND | DR 9.1 | +| | R-RSUI/<br>RDDP | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDR | | STOP<br>T1 | | S-ACT<br>INT IND | DR 8.1 | STOP<br>T1 | | S-ACT<br>INT IND | DR 8.1 | STOP<br>T1 | | S-ACT<br>INT IND | DR 8.1 | | | S-ACT<br>INT IND | DR 8.1 | +| | R-RSUI/<br>RDRP | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDUI | | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | RESTART<br>T1 | | S-DATA<br>IND | DR 3.1 | RESTART<br>T1 | | S-DATA<br>IND | DR 3.1 | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | +| | | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | | | | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | + +TABLE H.1/T.62 (continued) +**State transition tables for calling terminal** + +Calling terminal + +| Event | | | State: 11 Document receive | | | | | | | | | | | | | | | | +|-------------|-----------------------------------------------------------------|-------------------|----------------------------|-----------------|-----------------------------|-------------|---------------|-----------------|-----------------------------|--------------|---------------|-----------------|-----------------------------|--------------|-------------|-----------------|-----------------------------|--------------| +| | | | DR 1.1 | | | | DR 2.1 | | | | DR 3.1 | | | | DR 4.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-RSUI/<br>RDGR | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R CSUI/<br>CDPB (I)<br>$\wedge (P-Q) < (W-1)$<br>$\wedge I = P$ | | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | RESTART<br>T1 | | S-SYNC<br>MIN IND<br>5) | DR 2.1<br>3) | RESTART<br>T1 | | S-SYNC<br>MIN IND | DR 2.1 | | | S-SYNC<br>MIN IND<br>5) | DR 4.1<br>3) | +| | | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | | | | | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | +| | | | | | | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | COUNTER:<br>P = P + 1 | | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R CSUI/<br>CDPB (I)<br>$\wedge (P-Q) = (W-1)$<br>$\wedge I = P$ | | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | RESTART<br>T1 | | S-SYNC<br>MIN IND<br>5) | DR 2.1<br>3) | STOP<br>T1 | | S-SYNC<br>MIN IND | DR 4.1 | | | S-SYNC<br>MIN IND<br>5) | DR 4.1<br>3) | +| | | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | | | | | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | +| | | | | | | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | COUNTER:<br>P = P + 1 | | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDPB (I)<br>$\wedge I \neq P$ | | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | RESTART<br>T1 | | S-SYNC<br>MIN IND<br>5) | DR 2.1<br>3) | RESTART<br>T1 | | S-SYNC<br>MIN IND<br>6) | DR 2.1<br>3) | | | S-SYNC<br>MIN IND<br>5) | DR 4.1<br>3) | +| | | | | | | | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | +| | | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 11 Document receive | | | | | | | | | | | | | | | | +|--------------|-----------------------------------------------------------------------------|-------------------|---------------------|-----------------|-----------------------|-------------|------------|-----------------|-----------------------|-------------|------------|-----------------|-----------------------|-------------|----------|-----------------|-----------------------|-------------| +| Event | | | DR 1.1 | | | | DR 2.1 | | | | DR 3.1 | | | | DR 4.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-RSUI/RDPBP (K) | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/RDPBN | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | ANY OTHER DOCUMENT COMMAND OR RESP. OR WRONG FORMAT IN CONNECTION WITH CSUI | | RESTART T1 | S-RSUI/RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | RESTART T1 | S-RSUI/RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | RESTART T1 | S-RSUI/RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | START T1 | S-RSUI/RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | +| | | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | ANY OTHER COMMAND OR RESP. OR WRONG FORMAT | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| EXPIRY OF T1 | | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | (-----) | | | | +| EXPIRY OF T2 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| EXPIRY OF T3 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| Event | | | State | | | | | | | | | | | | | | | | +|-------------|----------------|---------------------------------------|---------------------|-------------------|----------------------|-------------|----------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------| +| | | | 11 Document receive | | | | | | | | | | | | | | | | +| | | | DR 5.1 | | | | DR 6.1 | | | | DR 7.1 | | | | DR 8.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CON REQ | | | | | | | | | | | | | | | | | +| | | S-REL REQ | | | | | | | | | | | | | | | | | +| | | S-CTRL GIVE REQ | | | | | | | | | | | | | | | | | +| | | S-CTRL GIVE RESP | | | | | | | | | | | | | | | | | +| | | S-SYNC MIN REQ (I) | | | | | | | | | | | | | | | | | +| | | S-SYNC MIN RESP (K)<br>$\wedge K = Q$ | | S-RSUI/ RDPBP (K) | COUNTER: $Q = Q + 1$ | DR 5.1 | | | | | | | | | | | | | +| | | S-U-EXPT REQ | START T1 | S-RSUI/ RDPBN | | DR 7.1 | | | | | | | | | | | | | +| | | S-ACT END REQ (I) | | | | | | | | | | | | | | | | | +| | | S-ACT END RESP (K) | START T1 | S-RSUI/ RDEP | | DR 1.1 | | | | | | | | | | | | | +| | | S-U-ABT REQ | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| Event State | | | 11 Document receive | | | | | | | | | | | | | | | | +|-------------|----------------|--------------------------|---------------------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|--------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------| +| | | | DR 5.1 | | | | DR 6.1 | | | | DR 7.1 | | | | DR 8.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-U-ABT RESP | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT BEG (START) REQ | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT BEG (CONT) REQ (C) | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-DATA REQ | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT DCAD REQ | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT DCAD RESP | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT INT REQ | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT INT RESP | ( ) | | | | ( ) | | | | ( ) | | | | START T1 | S-RSUI/ RDRP | | DR 1.1 | +| | | S-CAPAB DATA REQ | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-CAPAB DATA RESP | ( ) | | | | START T1 | S-RSUI/ RDCLP | | DR 1.1 | ( ) | | | | ( ) | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 11 Document receive | | | | | | | | | | | | | | | | +|-------------|----------------|-------------------|---------------------|-----------------|-----------------------------|-------------|--------|-----------------|-----------------------------|-------------|------------|-----------------|---------------------------|-------------|--------|-----------------|---------------------------|-------------| +| Event | | | DR 5.1 | | | | DR 6.1 | | | | DR 7.1 | | | | DR 8.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | T-CON<br>CONF | | | | | | | | | | | | | | | | | +| | | T-DISCON<br>IND | | | S-P-ABT<br>IND | 0.1 | | | S-P-ABT<br>IND | 0.1 | STOP<br>T1 | | S-P-ABT<br>IND | 0.1 | | | S-P-ABT<br>IND | 0.1 | +| | | T-EXPT<br>IND | | | S-P-EXPT<br>IND<br>(ERR) 3) | DR 5.1 | | | S-P-EXPT<br>IND<br>(ERR) 3) | DR 6.1 | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSS | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSSP | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSSN | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSE | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSEP | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSA | | | | S-ABT<br>IND | 7.1 | | | S-ABT<br>IND | 7.1 | STOP<br>T1 | | S-ABT<br>IND | 7.1 | | | S-ABT<br>IND | 7.1 | +| | R-RSAP | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 11 Document receive | | | | | | | | | | | | | | | | +|-------------|-----------------|-------------------|---------------------|-----------------|-----------------------|-------------|----------|-----------------|-----------------------|-------------|---------|-----------------|---------------------|-------------|--------|-----------------|---------------------|-------------| +| Event | | | DR 5.1 | | | | DR 6.1 | | | | DR 7.1 | | | | DR 8.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSCC | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSCCP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDS | | START T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | START T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | | | | DR 7.1 | | | S-P-EXPT IND (FAIL) | x | +| | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | | | | | | +| | R-CSUI/ CDC (C) | | START T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | START T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | | | | DR 7.1 | | | S-P-EXPT IND (FAIL) | x | +| | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | | | | | | +| | R-CSUI/ CDCL | | START T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | START T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | | | | DR 7.1 | | | S-P-EXPT IND (FAIL) | x | +| | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | | | | | | +| | R-RSUI/ RDCLP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 11 Document receive | | | | | | | | | | | | | | | | +|-------------|---------------------|-------------------|---------------------|-----------------|-----------------------------|-------------|-------------|-----------------|-----------------------------|-------------|------------|-----------------|---------------------------|-------------|--------|-----------------|---------------------------|-------------| +| Event | | | DR 5.1 | | | | DR 6.1 | | | | DR 7.1 | | | | DR 8.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/<br>CDE (I) | | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | | | | DR 7.1 | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | | | | | | +| | R-RSUI/<br>RDEP (K) | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDD | | | | S-ACT<br>DCAD<br>IND | DR 9.1 | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | STOP<br>T1 | | S-ACT<br>DCAD<br>IND | DR 9.1 | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDDP | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDR | | | | S-ACT<br>INT<br>IND | DR 8.1 | | | S-ACT<br>INT<br>IND | DR 8.1 | STOP<br>T1 | | S-ACT<br>INT<br>IND | DR 8.1 | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDRP | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 11 Document receive | | | | | | | | | | | | | | | | +|-------------|-------------------------|-------------------|---------------------|-----------------|-----------------------------|-------------|-------------|-----------------|-----------------------------|-------------|------------|-----------------|---------------------------|-------------|--------|-----------------|---------------------------|-------------| +| Event | | | DR 5.1 | | | | DR 6.1 | | | | DR 7.1 | | | | DR 8.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/<br>CDUI | | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | | | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | DR 7.1 | | | | | +| | R-RSUI/<br>RDGR | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDPB (I) | | (-----) | | | | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | | | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | | | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | DR 7.1 | | | | | +| | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | | | | | | | | | | +| | R-RSUI/<br>RDPBP<br>(K) | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDPBN | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 11 Document receive | | | | | | | | | | | | | | | | +|--------------|-----------------------------------------------------------------------------|-------------------|---------------------|-----------------|----------------------|-------------|----------|-----------------|----------------------|-------------|---------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------| +| Event | | | DR 5.1 | | | | DR 6.1 | | | | DR 7.1 | | | | DR 8.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | ANY OTHER DOCUMENT COMMAND OR RESP. OR WRONG FORMAT IN CONNECTION WITH CSUI | | START T1 | S-RSUI/RDGR | S-P-EXPT IND (ERR) 3 | DR 7.1 | START T1 | S-RSUI/RDGR | S-P-EXPT IND (ERR) 3 | DR 7.1 | | | | | | | S-P-EXPT IND (FAIL) | x | +| | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | DR 7.1 | | | | | +| | ANY OTHER COMMAND OR RESP. OR WRONG FORMAT | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| EXPIRY OF T1 | | | (-----) | | | | (-----) | | | | STOP T1 | | S-P-EXPT IND (FAIL) | x | (-----) | | | | +| EXPIRY OF T2 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| EXPIRY OF T3 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 11 Document receive | | | | Wait | | | | Wait | | | | Wait | | | | +|-------------|----------------|---------------------|---------------------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------| +| Event | | | DR 9.1 | | | | 12.1 | | | | 13.1 | | | | 14.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CON REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-REL REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CTRL GIVE REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CTRL GIVE RESP | (-----) | | | | | S-RSCCP | | DS 1.1 | (-----) | | | | (-----) | | | | +| | | S-SYNC MIN REQ (I) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-SYNC MIN RESP (K) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-U-EXPT REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT END REQ (I) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT END RESP (K) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-U-ABT REQ | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | (-----) | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 11 Document receive | | | | Wait | | | | Wait | | | | Wait | | | | +|-------------|----------------|--------------------------|---------------------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------| +| Event | | | DR 9.1 | | | | 12.1 | | | | 13.1 | | | | 14.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-U-ABT RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT BEG (START) REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT BEG (CONT) REQ (C) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT DCAD REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT DCAD RESP | START T1 | S-RSUI/ RDDP | | DR 1.1 | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT INT REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT INT RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CAPAB DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CAPAB DATA RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 11 Document receive | | | | Wait | | | | Wait | | | | Wait | | | | +|-------------|----------------|-------------------|---------------------|-----------------|---------------------------|-------------|---------|-----------------|---------------------------|-------------|------------|-----------------|-------------------------------|-------------|------------|-----------------|-------------------|-------------| +| Event | | | DR 9.1 | | | | 12.1 | | | | 13.1 | | | | 14.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | T-CON<br>CONF | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | T-DISCON<br>IND | | | S-P-ABT<br>IND | 0.1 | | | S-P-ABT<br>IND | 0.1 | STOP<br>T2 | | S-P-ABT<br>IND | 0.1 | STOP<br>T3 | | S-P-ABT<br>IND | 0.1 | +| | | T-EXPT<br>IND | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | 14.1 | +| | R-CSS | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | 14.1 | +| | R-RSSP | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | 14.1 | +| | R-RSSN | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | 14.1 | +| | R-CSE | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | 14.1 | +| | R-RSEP | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-REL<br>CONF | 0.2<br>7) | | | | 14.1 | +| | | | | | | | | | | | | | S-REL<br>CONF/ T-<br>DISC REQ | 0.1 | | | | | +| | R-CSA | | | | S-ABT<br>IND | 7.1 | | | S-ABT<br>IND | 7.1 | STOP<br>T2 | | S-ABT<br>IND | 7.1 | | | | 14.1 | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 11 Document receive | | | | Wait | | | | Wait | | | | Wait | | | | +|-------------|-----------------|-------------------|---------------------|-----------------|---------------------|-------------|-------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------|---------|-----------------|------------------------|-------------| +| Event | | | DR 9.1 | | | | 12.1 | | | | 13.1 | | | | 14.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-RSAP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T3 | | S-ABT CONF | 0.2 7) | +| | | | | | | | | | | | | | | | | | S-ABT CONF/ T-DISC REQ | 0.1 | +| | R-CSCC | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-RSCCP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-CSUI/ CDS | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-CSUI/ CDC (C) | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-CSUI/ CDCL | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-RSUI/ RDCLP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-CSUI/ CDE (I) | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | 11 Document receive | | | | Wait | | | | Wait | | | | Wait | | | | +|-------------|----------------------|-------------------|---------------------|-----------------|---------------------------|-------------|-------|-----------------|---------------------------|-------------|------------|-----------------|---------------------------|-------------|-------|-----------------|-------------------|-------------| +| Event | | | DR 9.1 | | | | 12.1 | | | | 13.1 | | | | 14.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-RSUI/<br>RDEP (K) | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | 14.1 | +| | R-CSUI/<br>CDD | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | 14.1 | +| | R-RSUI/<br>RDDP | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | 14.1 | +| | R-CSUI/<br>CDR | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | 14.1 | +| | R-RSUI/<br>RDRP | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | 14.1 | +| | R-CSUI/<br>CDUI | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | 14.1 | +| | R-RSUI/<br>RDGR | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | 14.1 | +| | R-CSUI/<br>CDPB (I) | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | 14.1 | +| | R-RSUI/<br>RDPBP (K) | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | 14.1 | + +TABLE H.1/T.62 (continued) +**State transition tables for calling terminal** + +Calling terminal + +| State | | | 11 Document receive | | | | Wait | | | | Wait | | | | Wait | | | | +|--------------|-----------------------------------------------------|-------------------|---------------------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------|---------|-----------------|--------------------------|-------------| +| Event | | | DR 9.1 | | | | 12.1 | | | | 13.1 | | | | 14.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-RSUI/RDPBN | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | ANY OTHER DOCUMENT COMMAND OR RESP. OR WRONG FORMAT | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| EXPIRY OF T1 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| EXPIRY OF T2 | | | (-----) | | | | (-----) | | | | STOP T2 | | S-P-EXPT IND (FAIL) | x | (-----) | | | | +| EXPIRY OF T3 | | | (-----) | | | | (-----) | | | | (-----) | | | | STOP T3 | | S-P-ABT IND T-DISCON REQ | 0.1 | + +TABLE H.1/T.62 (continued) +**State transition tables for calling terminal** + +Calling terminal + +| Event | | | State | | | | +|-------------|----------------|--------------------------------|-------------|-----------------|-------------------|-------------| +| | | | Wait | | | | +| | | | x | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | +| | | S-CON REQ | ( ) | | | | +| | | S-REL REQ | ( ) | | | | +| | | S-CTRL<br>GIVE REQ | ( ) | | | | +| | | S-CTRL<br>GIVE RESP | ( ) | | | | +| | | S-SYNC<br>MIN<br>REQ (I) | ( ) | | | | +| | | S-SYNC<br>MIN<br>RESP (K) | ( ) | | | | +| | | S-U-EXPT<br>REQ | ( ) | | | | +| | | S-ACT END<br>REQ (I) | ( ) | | | | +| | | S-ACT END<br>RESP (K) | ( ) | | | | +| | | S-U-ABT<br>REQ | START<br>T3 | S-CSA | | 14.1 | +| | | S-U-ABT<br>RESP | ( ) | | | | +| | | S-ACT BEG<br>(START)<br>REQ | ( ) | | | | +| | | S-ACT BEG<br>(CONT)<br>REQ (C) | ( ) | | | | +| | | S-DATA<br>REQ | ( ) | | | | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| Event | | | State | Wait | | | +|-------------|----------------|-------------------------|---------|-----------------|-------------------|-------------| +| | | | x | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | +| | | S-ACT<br>DCAD REQ | (-----) | | | | +| | | S-ACT<br>DCAD<br>RESP | (-----) | | | | +| | | S-ACT<br>INT REQ | (-----) | | | | +| | | S-ACT<br>INT RESP | (-----) | | | | +| | | S-CAPAB<br>DATA REQ | (-----) | | | | +| | | S-CAPAB<br>DATA<br>RESP | (-----) | | | | +| | | T-CON<br>CONF | (-----) | | | | +| | | T-DISCON<br>IND | | | S-P-ABT<br>IND | 0.1 | +| | | T-EXPT<br>IND | | | | x | +| | R-CSS | | | | | x | +| | R-RSSP | | | | | x | +| | R-RSSN | | | | | x | +| | R-CSE | | | | | x | +| | R-RSEP | | | | | x | + +TABLE H.1/T.62 (continued) +State transition tables for calling terminal + +Calling terminal + +| State | | | Wait | | | | +|-------------|---------------------|-------------------|-------|-----------------|-------------------|-------------| +| Event | | | x | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | +| | R-CSA | | | | S-ABT<br>IND | 7.1 | +| | R-RSAP | | | | | x | +| | R-CSCC | | | | | x | +| | R-RSCCP | | | | | x | +| | R-CSUI/<br>CDS | | | | | x | +| | R-CSUI/<br>CDC (C) | | | | | x | +| | R-CSUI/<br>CDCL | | | | | x | +| | R-RSUI/<br>RDCLP | | | | | x | +| | R-CSUI/<br>CDE (I) | | | | | x | +| | R-RSUI/<br>RDEP (K) | | | | | x | +| | R-CSUI/<br>CDD | | | | | x | +| | R-RSUI/<br>RDDP | | | | | x | +| | R-CSUI/<br>CDR | | | | | x | +| | R-RSUI/<br>RDRP | | | | | x | + +TABLE H.1/T.62 (*end*) +**State transition tables for calling terminal** + +Calling terminal + +| State | | | Wait | | | | +|-----------------|--------------------------------------------------------|-------------------|---------|-----------------|-------------------|-------------| +| Event | | | x | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/<br>CDUI | | | | | x | +| | R-RSUI/<br>RDGR | | | | | x | +| | R-CSUI/<br>CDPB (I) | | | | | x | +| | R-RSUI/<br>RDPBP (K) | | | | | x | +| | R-RSUI/<br>RDPBN | | | | | x | +| | ANY OTHER<br>COMMAND<br>OR RESP.<br>OR WRONG<br>FORMAT | | | | | x | +| EXPIRY<br>OF T1 | | | (-----) | | | | +| EXPIRY<br>OF T2 | | | (-----) | | | | +| EXPIRY<br>OF T3 | | | (-----) | | | | + +TABLE H.2/T.62 +State transition tables for called terminal + +Called terminal + +| State | | | Idle | | | | | | | | Wait | | | | +|-------------|----------------|--------------------|----------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------| +| Event | | | 0.1 | | | | 0.2 | | | | 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CON RESP POS | (------) | | | | (------) | | | | (------) | | | | +| | | S-CON RESP NEG | (------) | | | | (------) | | | | (------) | | | | +| | | S-REL RESP | (------) | | | | (------) | | | | (------) | | | | +| | | S-CTRL GIVE REQ | (------) | | | | (------) | | | | (------) | | | | +| | | S-CTRL GIVE RESP | (------) | | | | (------) | | | | (------) | | | | +| | | S-SYNC MIN REQ (I) | (------) | | | | (------) | | | | (------) | | | | +| | | S-SYNC MIN REQ (K) | (------) | | | | (------) | | | | (------) | | | | +| | | S-U-EXPT REQ | (------) | | | | (------) | | | | (------) | | | | +| | | S-ACT END REQ (I) | (------) | | | | (------) | | | | (------) | | | | +| | | S-ACT END RESP (K) | (------) | | | | (------) | | | | (------) | | | | +| | | S-U-ABT REQ | (------) | | | | (------) | | | | (------) | | | | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | Idle | | | | | | | | Wait | | | | | +|-------------|----------------|---------------------------|----------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|--| +| | | | 0.1 | | | | 0.2 | | | | 7.1 | | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | | +| | | S-U-ABT RESP | (-----) | | | | (-----) | | | | START T3 | S-RSAP | | 0.2 | | +| | | | | | | | | | | | START T1 | S-RSAP | 1) | | | +| | | S-ACT BEG (START) REQ | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-ACT BEG (CONT) REQ (C) | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-DATA REQ. | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-ACT DCAD REQ | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-ACT DCAD RESP | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-ACT INT REQ | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-ACT INT RESP | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-CAPAB DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-CAPAB DATA RESP | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | T-CON IND ^ T CON ACCEPT. | START T1 | | T-CON RESP POS | 0.2 | (-----) | | | | (-----) | | | | | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | Idle | | | | | | | | Wait | | | | +|-------------|----------------|----------------------------------|---------|-----------------|-------------------|-------------|-----------------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------| +| Event | | | 0.1 | | | | 0.2 | | | | 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | T-CON IND<br>^T-CON<br>¬ ACCEPT. | | | T-DISC REQ | 0.1 | (-----) | | | | (-----) | | | | +| | | T-DISCON IND | (-----) | | | | STOP<br>T1 ∨ T3 | | | 0.1 | | | S-P-ABT IND | 0.1 | +| | | T-EXPT IND | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON REQ | 0.1 | | | | 7.1 | +| | R-CSS | | (-----) | | | | STOP<br>T1 | | S-CON IND | 1.1 | | | | 7.1 | +| | R-RSSP | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON REQ | 0.1 | | | | 7.1 | +| | R-RSSN | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON REQ | 0.1 | | | | 7.1 | +| | R-CSE | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON REQ | 0.1 | | | | 7.1 | +| | R-RSEP | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON REQ | 0.1 | | | | 7.1 | +| | R-CSA | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON REQ | 0.1 | | | | 7.1 | +| | R-RSAP | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON REQ | 0.1 | | | | 7.1 | +| | R-CSCC | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON REQ | 0.1 | | | | 7.1 | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State<br>Event | | | Idle | | | | | | | | Wait | | | | +|----------------|---------------------|-------------------|---------|-----------------|-------------------|-------------|-----------------|-----------------|-------------------|-------------|-------|-----------------|-------------------|-------------| +| | | | 0.1 | | | | 0.2 | | | | 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-RSCCP | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | +| | R-CSUI/<br>CDS | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | +| | R-CSUI/<br>CDC (C) | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | +| | R-CSUI/<br>CDCL | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | +| | R-CSUI/<br>RDCLP | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | +| | R-CSUI/<br>CDE (I) | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | +| | R-RSUI/<br>RDEP (K) | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | +| | R-CSUI/<br>CDD | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | +| | R-RSUI/<br>RDDP | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | +| | R-CSUI/<br>CDR | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | +| | R-RSUI/<br>RDRP | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | Idle | | | | | | | | Wait | | | | +|-----------------|----------------------------------------------------------|-------------------|---------|-----------------|-------------------|-------------|-----------------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------| +| Event | | | 0.1 | | | | 0.2 | | | | 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/CDUI | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | +| | R-RSUI/RDGR | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | +| | R-CSUI/CDPB | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | +| | R-RSUI/RDPBP (K) | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | +| | R-RSUI/RDPBN | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | +| | ANY<br>OTHER<br>COMMAND<br>OR RESP<br>OR WRONG<br>FORMAT | | (-----) | | | | STOP<br>T1 ∨ T3 | | T-DISCON<br>REQ | 0.1 | | | | 7.1 | +| EXPIRY<br>OF T1 | | | (-----) | | | | STOP<br>T1 | | T-DISCON<br>REQ | 0.1 | (-----) | | | | +| EXPIRY<br>OF T2 | | | (-----) | | | | (-----) | | | | (-----) | | | | +| EXPIRY<br>OF T3 | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | Wait | | | | 4 Document send | | | | | | | | | | | | +|-------------|----------------|--------------------------------------------------------------------|----------|-----------------|-------------------|-------------|-----------------|-----------------|-------------------|-------------|--------|-----------------|-------------------|-------------|----------|---------------------------------|-------------------|-------------| +| | | | 1.1 | | | | DS 1.1 | | | | DS 2.1 | | | | DS 3.1 | | | | +| Event | | | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| Local event | Protocol event | Service primitive | | | | | | | | | | | | | | | | | +| | | S-CON RESP POS | START T1 | S-RSSP | | DR 1.1 | | | | | | | | | | | | | +| | | S-CON RESP NEG | START T1 | S-RSSN | | 0.2 | | | | | | | | | | | | | +| | | S-REL RESP | | | | | | | | | | | | | | | | | +| | | S-CTRL GIVE REQ | | | | | START T2 | S-CSCC | | 5.1 | | | | | | | | | +| | | S-CTRL GIVE RESP | | | | | | | | | | | | | | | | | +| | | S-SYNC MIN REQ (I)<br>$\wedge (S - R) < (W - 1)$<br>$\wedge I = S$ | | | | | | | | | | | | | START T2 | S-CSUI/ CDPB (I)<br>$S = S + 1$ | | DS 2.1 | +| | | S-SYNC MIN REQ (I)<br>$\wedge (S - R) = (W - 1)$<br>$\wedge I = S$ | | | | | | | | | | | | | START T2 | S-CSUI/ CDPB (I)<br>$S = S + 1$ | | DS 4.1 | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | Wait | | | | 4 Document send | | | | | | | | | | | | +|-------------|----------------|--------------------------|----------|-----------------|-------------------|-------------|-----------------|----------------------------------|-------------------|-------------|----------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------| +| Event | | | 1.1 | | | | DS 1.1 | | | | DS 2.1 | | | | DS 3.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-SYNC MIN RESP (K) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-U-EXPT REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT END REQ (I) | (-----) | | | | (-----) | | | | (-----) | | | | START T2 | S-CSUI/ CDE (I) | | DS 5.1 | +| | | S-ACT END RESP (K) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-U-ABT REQ | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | +| | | S-U-ABT RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT BEG (START) REQ | (-----) | | | | | S-CSUI/ CDS<br>S = R = 1 | | DS 2.1 | (-----) | | | | (-----) | | | | +| | | S-ACT BEG (CONT) REQ (C) | (-----) | | | | | S-CSUI/ CDC (C)<br>S = R = C + 1 | | DS 2.1 | (-----) | | | | (-----) | | | | +| | | S-DATA REQ | (-----) | | | | (-----) | | | | | S-CSUI/ CDUI | | DS 3.1 | | S-CSUI/ CDUI | | DS 3.1 | +| | | S-ACT DCAD REQ | (-----) | | | | (-----) | | | | START T2 | S-CSUI/ CDD | | DS 9.1 | START T2 | S-CSUI/ CDD | | DS 9.1 | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | Wait | | | | 4 Document send | | | | | | | | | | | | +|-------------|----------------|-------------------|---------|-----------------|---------------------|-------------|-----------------|-----------------|---------------------|-------------|----------|-----------------|-----------------------|-------------|----------|-----------------|-----------------------|-------------| +| Event | | | 1.1 | | | | DS 1.1 | | | | DS 2.1 | | | | DS 3.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-ACT DCAD RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT INT REQ | (-----) | | | | (-----) | | | | START T2 | S-CSUI/ CDR | | DS 8.1 | START T2 | S-CSUI/ CDR | | DS 8.1 | +| | | S-ACT INT RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CAPAB DATA REQ | (-----) | | | | START T2 | S-CSUI/ CDCL | | DS 6.1 | (-----) | | | | (-----) | | | | +| | | S-CAPAB DATA RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | T-CON IND | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | T-DISCON IND | | | S-P-ABT IND | 0.1 | | | S-P-ABT IND | 0.1 | STOP T2 | | S-P-ABT IND | 0.1 | STOP T2 | | S-P-ABT IND | 0.1 | +| | | T-EXPT IND | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSS | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | + +TABLE H.2/T.62 (continued) + +### State transition tables for called terminal + +Called terminal + +| State | | | Wait | | | | 4 Document send | | | | | | | | | | | | +|-------------|----------------|-------------------|-------|-----------------|---------------------|-------------|-----------------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------| +| Event | | | 1.1 | | | | DS 1.1 | | | | DS 2.1 | | | | DS 3.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-RSSP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSSN | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSE | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSEP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSA | | | | S-ABT IND | 7.1 | | | S-ABT IND | 7.1 | STOP T2 | | S-ABT IND | 7.1 | STOP T2 | | S-ABT IND | 7.1 | +| | R-RSAP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSCC | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSCCP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDS | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | Wait | | | | 4 Document send | | | | | | | | | | | | +|-------------|--------------------------------|-------------------|-------|-----------------|---------------------------|-------------|-----------------|-----------------|---------------------------|-------------|------------|-----------------|-----------------------------|-------------|------------|-----------------|-----------------------------|-------------| +| Event | | | 1.1 | | | | DS 1.1 | | | | DS 2.1 | | | | DS 3.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/<br>CDC (C) | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDCL | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDCLP | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT IND<br>(FAIL) | x | | | S-P-EXPT IND<br>(FAIL) | x | +| | R-CSUI/<br>CDE (I) | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDEP (K)<br>^ K = R | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT IND<br>(FAIL) | x | | | S-P-EXPT IND<br>(FAIL) | x | +| | R-CSUI/<br>CDD | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | Attente | | | | 4 Document send | | | | | | | | | | | | +|-------------|----------------------------------------|-------------------|---------|-----------------|---------------------|-------|-----------------|-----------------|---------------------|-------------|------------|-----------------|---------------------------|-------------|---------|-----------------|---------------------------|-------------| +| Event | | | 1.1 | | | | DS 1.1 | | | | DS 2.1 | | | | DS 3.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Timer | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-RSUI/RDDP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/CDR | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/RDRP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/CDUI | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/RDGR | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/CDPB (I) | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/RDPBP (K)<br>^ K = R<br>^ S > R | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | RESTART T2 | | S-SYNC MIN CONF R = R + 1 | DS 2.1 | | | S-SYNC MIN CONF R = R + 1 | DS 3.1 | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | Wait | | | | 4 Document send | | | | | | | | | | | | +|-----------------|-------------------------------------------------------------------------------------------------|-------------------|-------|-----------------|---------------------------|-------------|-----------------|-----------------|---------------------------|-------------|------------|-----------------|--------------------------------------|-------------|------------|-----------------|-----------------------------------|-------------| +| Event | | | 1.1 | | | | DS 1.1 | | | | DS 2.1 | | | | DS 3.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-RSUI/<br>RDPBP (K)<br>$\wedge K = R$<br>$\wedge S = R + 1$ | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-SYNC<br>MIN<br>CONF<br>$R = R + 1$ | DS 2.1 | STOP<br>T2 | | S-SYNC<br>MIN CONF<br>$R = R + 1$ | DS 3.1 | +| | R-RSUI/<br>RDPBN | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-U-EXPT<br>IND 3) | DS 7.1 | STOP<br>T2 | | S-U-EXPT<br>IND 3) | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT IND<br>(FAIL) | x | | | S-P-EXPT IND<br>(FAIL) | x | +| | ANY OTHER<br>DOCUMENT<br>COMMAND<br>OR RESP<br>OR WRONG<br>FORMAT IN<br>CONNECTION<br>WITH RSUI | | | | S-PEXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | ANY OTHER<br>COMMAND<br>OR RESP<br>OR WRONG<br>FORMAT | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | +| EXPIRY<br>OF T1 | | | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| EXPIRY<br>OF T2 | | | ( ) | | | | ( ) | | | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | +| EXPIRY<br>OF T3 | | | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 4 Document send | | | | | | | | | | | | | | | | +|-------------|----------------|---------------------|-----------------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------| +| Event | | | DS 4.1 | | | | DS 5.1 | | | | DS 6.1 | | | | DS 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CON RESP POS | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CON RESP NEG | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-REL RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CTRL GIVE REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CTRL GIVE RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-SYNC MIN REQ (I) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-SYNC MIN RESP (K) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-U-EXPT REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT END REQ (I) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT END RESP (K) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 4 Document send | | | | | | | | | | | | | | | | | +|-------------|----------------|--------------------------|-----------------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|--| +| | | | DS 4.1 | | | | DS 5.1 | | | | DS 6.1 | | | | DS 7.1 | | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | | +| | | S-U ABT REQ | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | | +| | | S-U-ABT RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-ACT BEG (START) REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-ACT BEG (CONT) REQ (C) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-ACT DCAD REQ | START T2 | S-CSUI/CDD | | DS 9.1 | START T2 | S-CSUI/CDD | | DS 9.1 | (-----) | | | | START T2 | S-CSUI/CDD | | DS 9.1 | | +| | | S-ACT DCAD RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | | +| | | S-ACT INT REQ | START T2 | S-CSUI/CDR | | DS 8.1 | START T2 | S-CSUI/CDR | | DS 8.1 | START T2 | S-CSUI/CDR | | DS 8.1 | START T2 | S-CSUI/CDR | | DS 8.1 | | +| | | S-ACT INT RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 4 Document send | | | | | | | | | | | | | | | | +|-------------|----------------|-------------------|-----------------|-----------------|----------------------|-------------|---------|-----------------|----------------------|-------------|---------|-----------------|----------------------|-------------|---------|-----------------|---------------------|-------------| +| Event | | | DS 4.1 | | | | DS 5.1 | | | | DS 6.1 | | | | DS 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CAPAB DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CAPAB DATA RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | T-CON IND | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | T-DISCON IND | STOP T2 | | S-P-ABT IND | 0.1 | STOP T2 | | S-P-ABT IND | 0.1 | STOP T2 | | S-P-ABT IND | 0.1 | | | S-P-ABT IND | 0.1 | +| | | T-EXPT IND | STOP T2 | | S-P-EXPT IND (ERR) 3 | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3 | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3 | DS 7.1 | | | | DS 7.1 | +| | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSS | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSSP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSSN | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSE | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | + +TABLE H.2/T.62 (continued) + +### State transition tables for called terminal + +Called terminal + +| State | | | 4 Document send | | | | | | | | | | | | | | | | +|-------------|-----------------|-------------------|-----------------|-----------------|-----------------------|------------|---------|-----------------|-----------------------|------------|---------|---------------------|---------------------|------------|--------|---------------------|---------------------|------------| +| Event | | | DS 4.1 | | | | DS 5.1 | | | | DS 6.1 | | | | DS 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Etat final | Timer | Protocol action | Service primitive | Etat final | Timer | Action de protocole | Service primitive | Etat final | Timer | Action de protocole | Service primitive | Etat final | +| | R-RSEP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSA | | STOP T2 | | S-ABT IND | 7.1 | STOP T2 | | S-ABT IND | 7.1 | STOP T2 | | S-ABT IND | 7.1 | | | S-ABT IND | 7.1 | +| | R-RSAP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSCC | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSCCP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDS | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDC (C) | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDCL | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/ RDCLP | | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | STOP T2 | | S-CAPAB DATA CONF | DS 1.1 | | | | DS 7.1 | +| | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | | | | | | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 4 Document send | | | | | | | | | | | | | | | | +|-------------|---------------------------------------|-------------------|-----------------|-----------------|-----------------------------|-------------|------------|-----------------|-----------------------------|-------------|------------|-----------------|-----------------------------|-------------|--------|-----------------|---------------------------|-------------| +| Event | | | DS 4.1 | | | | DS 5.1 | | | | DS 6.1 | | | | DS 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/<br>CDE (I) | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDEP (K)<br>$\wedge K = R$ | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-ACT<br>END CONF | DS 1.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | | | | DS 7.1 | +| | | | | | S-P-EXPT IND<br>(FAIL) | x | | | | | | | S-P-EXPT IND<br>(FAIL) | x | | | | | +| | R-CSUI/<br>CDD | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDDP | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | | | | DS 7.1 | +| | | | | | S-P-EXPT IND<br>(FAIL) | x | | | S-P-EXPT IND<br>(FAIL) | x | | | S-P-EXPT IND<br>(FAIL) | x | | | | | +| | R-CSUI/<br>CDR | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDRP | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(ERR) 3) | DS 7.1 | | | | DS 7.1 | +| | | | | | S-P-EXPT IND<br>(FAIL) | x | | | S-P-EXPT IND<br>(FAIL) | x | | | S-P-EXPT IND<br>(FAIL) | x | | | | | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| Event | | | 4 Document send | | | | | | | | | | | | | | | | +|-------------|--------------------------------------------------------------|-------------------|-----------------|-----------------|--------------------------------|-------------|---------|-----------------|--------------------------------|-------------|---------|-----------------|-----------------------|-------------|--------|-----------------|---------------------|-------------| +| | | | DS 4.1 | | | | DS 5.1 | | | | DS 6.1 | | | | DS 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/<br>CDUI | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/<br>RDGR | | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | | | | DS 7.1 | +| | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | | +| | R-CSUI/<br>CDPB (I) | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/<br>RDPBP (K)<br>$\wedge K = R$<br>$\wedge S > R$ | | | | S-SYNC MIN CONF<br>$R = R + 1$ | DS 2.1 | | | S-SYNC MIN CONF<br>$R = R + 1$ | DS 5.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | | | | DS 7.1 | +| | | | | | | | | | | | | | S-P-EXPT IND (FAIL) | x | | | | | +| | R-RSUI/<br>RDPBP (K)<br>$\wedge K = R$<br>$\wedge S > R + 1$ | | STOP T2 | | S-SYNC MIN CONF<br>$R = R + 1$ | DS 2.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | | | | DS 7.1 | +| | | | | | | | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | | +| | R-RSUI/<br>RDPBN | | STOP T2 | | S-U-EXPT IND 3) | DS 7.1 | STOP T2 | | S-U-EXPT REQ 3) | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3) | DS 7.1 | | | | DS 7.1 | +| | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 4 Document send | | | | | | | | | | | | | | | | +|--------------|----------------------------------------------------------------------------|-------------------|-----------------|-----------------|----------------------|-------------|---------|-----------------|----------------------|-------------|---------|-----------------|----------------------|-------------|---------|-----------------|---------------------|-------------| +| Event | | | DS 4.1 | | | | DS 5.1 | | | | DS 6.1 | | | | DS 7.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | ANY OTHER DOCUMENT COMMAND OR RESP OR WRONG FORMAT IN CONNECTION WITH RSUI | | STOP T2 | | S-P-EXPT IND (ERR) 3 | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3 | DS 7.1 | STOP T2 | | S-P-EXPT IND (ERR) 3 | DS 7.1 | | | | DS 7.1 | +| | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | | +| | ANY OTHER COMMAND OR RESP OR WRONG FORMAT | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| EXPIRY OF T1 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| EXPIRY OF T2 | | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | (-----) | | | | +| EXPIRY OF T3 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.2/T.62 (continued) +**State transition tables for called terminal** + +Called terminal + +| State | | | 4 Document send | | | | | | | | Wait | | | | +|-------------|----------------|---------------------------------------------|-----------------|-----------------|-------------------|-------------|--------|-----------------|-------------------|-------------|-------|-----------------|-------------------|-------------| +| Event | | | DS 8.1 | | | | DS 9.1 | | | | 5.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CON<br>RESP POS | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-CON<br>RESP NEG | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-REL<br>RESP | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-CTRL<br>GIVE REQ | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-CTRL<br>GIVE RESP | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-SYNC<br>MIN<br>REQ (I) | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-SYNC<br>MIN RESP<br>(K)<br>$\wedge K = Q$ | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-U-EXPT<br>REQ | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT END<br>REQ (I) | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT END<br>RESP (K) | ( ) | | | | ( ) | | | | ( ) | | | | + +TABLE H.2/T.62 (continued) +**State transition tables for called terminal** + +Called terminal + +| State | | | 4 Document send | | | | | | | | Wait | | | | +|-------------|----------------|--------------------------|-----------------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------| +| | | | DS 8.1 | | | | DS 9.1 | | | | 5.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-U-ABT REQ | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | +| | | S-U-ABT RESP | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT BEG (START) REQ | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT BEG (CONT) REQ (C) | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT DCAD REQ | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT DCAD RESP | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT INT REQ | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT INT RESP | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CAPAB DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.2/T.62 (continued) + +### State transition tables for called terminal + +Called terminal + +| State | | | 4 Document send | | | | | | | | Wait | | | | +|-------------|----------------|-------------------|-----------------|-----------------|---------------------|-------------|-------------|-----------------|---------------------|-------------|-------------|-----------------|---------------------|-------------| +| Event | | | DS 8.1 | | | | DS 9.1 | | | | 5.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CAPAB DATA RESP | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | T-CON IND | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| | | T-DISCON IND | STOP T2 | | S-P-ABT IND | 0.1 | STOP T2 | | S-P-ABT IND | 0.1 | STOP T2 | | S-P-ABT IND | 0.1 | +| | | T-EXPT IND | | | | DS 8.1 | | | | DS 9.1 | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | | | | | +| | R-CSS | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSSP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSSN | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSE | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSEP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | + +TABLE H.2/T.62 (continued) + +### State transition tables for called terminal + +Called terminal + +| State | | | 4 Document send | | | | | | | | Wait | | | | +|-------------|-----------------|-------------------|-----------------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------| +| Event | | | DS 8.1 | | | | DS 9.1 | | | | 5.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSA | | STOP T2 | | S-ABT IND | 7.1 | STOP T2 | | S-ABT IND | 7.1 | STOP T2 | | S-ABT IND | 7.1 | +| | R-RSAP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSCC | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSCCP | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-CTRL GIVE CONF | DR 1.1 | +| | R-CSUI/ CDS | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDC (C) | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDCL | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/ RDCLP | | | | | DS 8.1 | | | | DS 9.1 | STOP T2 | | S-P-EXPT IND (FAIL) | x | + +TABLE H.2/T.62 (continued) + +### State transition tables for called terminal + +Called terminal + +| State | | | 4 Document send | | | | | | | | Wait | | | | +|-------------|-----------------|-------------------|-----------------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------| +| Event | | | DS 8.1 | | | | DS 9.1 | | | | 5.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/CDE (I) | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/RDEP (K) | | | | | DS 8.1 | | | | DS 9.1 | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/CDD | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/RDDP | | | | | DS 8.1 | STOP T2 | | S-ACT DCAD CONF | DS 1.1 | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/CDR | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/RDRP | | STOP T2 | | S-ACT INT CONF | DS 1.1 | | | | DS 9.1 | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/CDUI | | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | STOP T2 | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/RDGR | | | | | DS 8.1 | | | | DS 9.1 | STOP T2 | | S-P-EXPT IND (FAIL) | x | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 4 Document send | | | | | | | | Wait | | | | +|-----------------|-------------------------------------------------------------------------------------------------|-------------------|-----------------|-----------------|---------------------------|-------------|------------|-----------------|---------------------------|-------------|------------|-----------------|---------------------------|-------------| +| Event | | | DS 8.1 | | | | DS 9.1 | | | | 5.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/<br>CDPB (I) | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | | DS 9.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDPBP (K) | | | | | DS 8.1 | | | | DS 9.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDPBN | | | | | DS 8.1 | | | | DS 9.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | ANY OTHER<br>DOCUMENT<br>COMMAND<br>OR RESP<br>OR WRONG<br>FORMAT IN<br>CONNECTION<br>WITH RSUI | | | | | DS 8.1 | | | | DS 9.1 | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | ANY OTHER<br>COMMAND<br>OR RESP<br>OR WRONG<br>FORMAT | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | +| EXPIRY<br>OF T1 | | | (-----) | | | | (-----) | | | | (-----) | | | | +| EXPIRY<br>OF T2 | | | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T2 | | S-P-EXPT<br>IND<br>(FAIL) | x | +| EXPIRY<br>OF T3 | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | | | | | | | | | | | | | +|-------------|----------------|---------------------------------------|--------------------|-----------------|-------------------|-------------|------------|-------------------|--------------------|-------------|------------|-------------------|--------------------|-------------|----------|-------------------|--------------------|-------------| +| Event | | | DR 1.1 | | | | DR 2.1 | | | | DR 3.1 | | | | DR 4.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CON RESP POS | | | | | | | | | | | | | | | | | +| | | S-CON RESP NEG | | | | | | | | | | | | | | | | | +| | | S-REL RESP | | | | | | | | | | | | | | | | | +| | | S-CTRL GIVE REQ | | | | | | | | | | | | | | | | | +| | | S-CTRL GIVE RESP | | | | | | | | | | | | | | | | | +| | | S-SYNC MIN REQ (I) | | | | | | | | | | | | | | | | | +| | | S-SYNC MIN RESP (K)<br>$\wedge K = Q$ | | | | | RESTART T1 | S-RSUI/ RDPBP (K) | COUNTER: Q = Q + 1 | DR 2.1 | RESTART T1 | S-RSUI/ RDPBP (K) | COUNTER: Q = Q + 1 | DR 3.1 | START T1 | S-RSUI/ RDPBP (K) | COUNTER: Q = Q + 1 | DR 2.1 | +| | | S-U-EXPT REQ | | | | | RESTART T1 | S-RSUI/ RDPBN | | DR 7.1 | RESTART T1 | S-RSUI/ RDPBN | | DR 7.1 | START T1 | S-RSUI/ RDPBN | | DR 7.1 | + +TABLE H.2/T.62 (continued) +**State transition tables for called terminal** + +Called terminal + +| State | | | 2 Document receive | | | | | | | | | | | | | | | | +|-------------|----------------|--------------------------|--------------------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------| +| | | | DR 1.1 | | | | DR 2.1 | | | | DR 3.1 | | | | DR 4.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-ACT END REQ (I) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT END RESP (K) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-U-ABT REQ | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | +| | | S-U-ABT RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT BEG (START) REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT BEG (CONT) REQ (C) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT DCAD REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT DCAD RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | | | | | | | | | | | | | +|-------------|----------------|-------------------|--------------------|-----------------|----------------------|-------------|---------|-----------------|----------------------|-------------|---------|-----------------|----------------------|-------------|---------|-----------------|----------------------|-------------| +| Event | | | DR 1.1 | | | | DR 2.1 | | | | DR 3.1 | | | | DR 4.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-ACT INT REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT INT RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CAPAB DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CAPAB DATA RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | T-CON IND | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | T-DISCON IND | STOP T1 | | S-P-ABT IND | 0.1 | STOP T1 | | S-P-ABT IND | 0.1 | STOP T1 | | S-P-ABT IND | 0.1 | | | S-P-ABT IND | 0.1 | +| | | T-EXPT IND | | | S-P-EXPT IND (ERR) 3 | DR 1.1 | | | S-P-EXPT IND (ERR) 3 | DR 2.1 | | | S-P-EXPT IND (ERR) 3 | DR 3.1 | | | S-P-EXPT IND (ERR) 3 | DR 4.1 | +| | | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSS | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSSP | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | + +TABLE H.2/T.62 (continued) + +### State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | | | | | | | | | | | | | +|-------------|----------------|-------------------|--------------------|-----------------|------------------------------------|-------------|------------|-----------------|-----------------------|-------------|------------|-----------------|-----------------------|-------------|----------|-----------------|-----------------------|-------------| +| Event | | | DR 1.1 | | | | DR 2.1 | | | | DR 3.1 | | | | DR 4.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-RSSN | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSE | | STOP T1 | | S-REL IND | 6.1 | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSEP | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSA | | STOP T1 | | S-ABORT IND | 7.1 | STOP T1 | | S-ABORT IND | 7.1 | STOP T1 | | S-ABORT IND | 7.1 | | | S-ABORT IND | 7.1 | +| | R-RSAP | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSCC | | STOP T1 | | S-CTRL GIVE IND | 3.1 | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSCCP | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDS | | RESTART T1 | | S-ACT BEG (START) IND<br>P = Q = 1 | DR 2.1 | RESTART T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | RESTART T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | START T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | +| | | | | | | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| Event | | | State | | | | | | | | | | | | | | | | +|-------------|-----------------------------------------------------------------------|-------------------|--------------------|-----------------|----------------------------------------------|-------------|---------------|-----------------|-----------------------------|-------------|---------------|-----------------|-----------------------------|-------------|-------------|-----------------|-----------------------------|-------------| +| | | | 2 Document receive | | | | | | | | | | | | | | | | +| | | | DR 1.1 | | | | DR 2.1 | | | | DR 3.1 | | | | DR 4.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/<br>CDC (C) | | RESTART<br>T1 | | S-ACT BEG<br>(CON)<br>IND<br>$P = Q = C + 1$ | DR 2.1 | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | +| | | | | | | | STOP<br>T1 | | S-P-EXPT IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT IND<br>(FAIL) | x | | | S-P-EXPT IND<br>(FAIL) | x | +| | R-CSUI/<br>CDCL | | STOP<br>T1 | | S-CAPAB<br>DATA IND | DR 6.1 | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | +| | | | | | | | STOP<br>T1 | | S-P-EXPT IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT IND<br>(FAIL) | x | | | S-P-EXPT IND<br>(FAIL) | x | +| | R-RSUI/<br>RDCLP | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDE (I)<br>$\wedge (P - Q) \leq (W - 1)$<br>$\wedge I = P$ | | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | STOP<br>T1 | | S-ACT<br>END IND | DR 5.1 | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | +| | | | STOP<br>T1 | | S-P-EXPT IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT IND<br>(FAIL) | x | | | | | | | S-P-EXPT IND<br>(FAIL) | x | +| | R-RSUI/<br>RDEP (K) | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDD | | STOP<br>T1 | | S-ACT<br>DCAD IND | DR 9.1 | STOP<br>T1 | | S-ACT<br>DCAD IND | DR 9.1 | STOP<br>T1 | | S-ACT<br>DCAD IND | DR 9.1 | | | S-ACT<br>DCAD IND | DR 9.1 | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | | | | | | | | | | | | | +|-------------|---------------------------------------------------------------------|-------------------|--------------------|-----------------|-----------------------------|-------------|---------------|-----------------|-----------------------------|--------------|---------------|-----------------------|---------------------------|-------------|-------------|-----------------|-----------------------------|--------------| +| Event | | | DR 1.1 | | | | DR 2.1 | | | | DR 3.1 | | | | DR 4.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-RSUI/<br>RDDP | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDR | | STOP<br>T1 | | S-ACT<br>INT IND | DR 8.1 | STOP<br>T1 | | S-ACT<br>INT IND | DR 8.1 | STOP<br>T1 | | S-ACT<br>INT IND | DR 8.1 | | | S-ACT<br>INT IND | DR 8.1 | +| | R-RSUI/<br>RDRP | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDUI | | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | RESTART<br>T1 | | S-DATA<br>IND | DR 3.1 | RESTART<br>T1 | | S-DATA<br>IND | DR 3.1 | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | +| | | | STOP<br>T1 | | S-P-EXPT IND<br>(FAIL) | x | | | | | | | | | | | S-P-EXPT IND<br>(FAIL) | x | +| | R-RSUI/<br>RDGR | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDPB (I)<br>$\wedge (P - Q) < (W - 1)$<br>$\wedge I = P$ | | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | RESTART<br>T1 | | S-SYNC<br>MIN IND<br>5) | DR 2.1<br>3) | RESTART<br>T1 | | S-SYNC<br>MIN IND | DR 2.1 | | | S-SYNC<br>MIN IND<br>5) | DR 4.1<br>3) | +| | | | STOP<br>T1 | | S-P-EXPT IND<br>(FAIL) | x | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | | | | | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | +| | | | | | | | STOP<br>T1 | | S-P-EXPT IND<br>(FAIL) | x | RESTART<br>T1 | COUNTER:<br>P = P + 1 | | | | | | | +| | | | | | | | | | | | | | | | | | S-P-EXPT IND<br>(FAIL) | x | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | | | | | | | | | | | | | +|-------------|-------------------------------------------------------------------------|-------------------|--------------------|-----------------|-----------------------------|-------------|---------------|-----------------|-----------------------------|--------------|---------------|-----------------|-----------------------------|--------------|-------------|-----------------|-----------------------------|--------------| +| Event | | | DR 1.1 | | | | DR 2.1 | | | | DR 3.1 | | | | DR 4.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/<br>CDPB (I)<br>$\wedge(P - Q) =$<br>$(W - 1)$<br>$\wedge I = P$ | | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | RESTART<br>T1 | | S-SYNC<br>MIN IND<br>5) | DR 2.1<br>3) | STOP<br>T1 | | S-SYNC<br>MIN IND | DR 4.1 | | | S-SYNC<br>MIN IND<br>5) | DR 4.1<br>3) | +| | | | STOP<br>T1 | | S-P-EXPT IND<br>(FAIL) | x | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | | | | | START<br>T1 | S-RSUI<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | +| | | | | | | | STOP<br>T1 | | S-P-EXPT IND<br>(FAIL) | x | | | | | | | S-P-EXPT IND<br>(FAIL) | x | +| | R-CSUI/<br>CDPB (I)<br>$\wedge I \neq P$ | | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | RESTART<br>T1 | | S-SYNC<br>MIN IND<br>5) | DR 2.1<br>3) | RESTART<br>T1 | | S-SYNC<br>MIN IND<br>6) | DR 2.1<br>3) | | | S-SYNC<br>MIN IND<br>5) | DR 4.1 | +| | | | STOP<br>T1 | | S-P-EXPT IND<br>(FAIL) | x | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | RESTART<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | START<br>T1 | S-RSUI<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | +| | | | | | | | STOP<br>T1 | | S-P-EXPT IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT IND<br>(FAIL) | x | | | S-P-EXPT IND<br>(FAIL) | x | +| | R-RSUI/<br>RDPBP (K) | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDPBN | | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | | | | | | | | | | | | | +|--------------|-------------------------------------------|-------------------|--------------------|-----------------|-----------------------|-------------|------------|-----------------|-----------------------|-------------|------------|-----------------|-----------------------|-------------|----------|-----------------|-----------------------|-------------| +| Event | | | DR 1.1 | | | | DR 2.1 | | | | DR 3.1 | | | | DR 4.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | ANY OTHER DOCUMENT COMMAND OR RESP | | RESTART T1 | S-RSUI/RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | RESTART T1 | S-RSUI/RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | RESTART T1 | S-RSUI/RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | START T1 | S-RSUI/RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | +| | OR WRONG FORMAT IN CONNECTION WITH CSUI | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | ANY OTHER COMMAND OR RESP OR WRONG FORMAT | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| EXPIRY OF T1 | | | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | (-----) | | | | +| EXPIRY OF T2 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| EXPIRY OF T3 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.2/T.62 (continued) +**State transition tables for called terminal** + +Called terminal + +| State | | | 2 Document receive | | | | | | | | | | | | | | | | +|-------------|----------------|---------------------------------------|--------------------|-------------------|-------------------------|-------------|--------|-----------------|-------------------|-------------|--------|-----------------|-------------------|-------------|--------|-----------------|-------------------|-------------| +| | | | DR 5.1 | | | | DR 6.1 | | | | DR 7.1 | | | | DR 8.1 | | | | +| Event | | | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| Local event | Protocol event | Service primitive | | | | | | | | | | | | | | | | | +| | | S-CON RESP POS | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-CON RESP NEG | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-REL RESP | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-CTRL GIVE REQ | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-CTRL GIVE RESP | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-SYNC MIN REQ (I) | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-SYNC MIN RESP (K)<br>$\wedge K = Q$ | | S-RSUI/ RDPBP (K) | COUNTER:<br>$Q = Q + 1$ | DR 5.1 | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-U-EXPT REQ | START T1 | S-RSUI/ RDPBN | | DR 7.1 | ( ) | | | | ( ) | | | | ( ) | | | | +| | | S-ACT END REQ (I) | ( ) | | | | ( ) | | | | ( ) | | | | ( ) | | | | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | | | | | | | | | | | | | +|-------------|----------------|--------------------------|--------------------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------| +| Event | | | DR 5.1 | | | | DR 6.1 | | | | DR 7.1 | | | | DR 8.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-ACT END RESP (K) | START T1 | S-RSUI/RDEP | | DR 1.1 | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-U ABT REQ | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | +| | | S-U-ABT RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT BEG (START) REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT BEG (CONT) REQ (C) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT DCAD REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT DCAD RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT INT REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT INT RESP | (-----) | | | | (-----) | | | | (-----) | | | | START T1 | S-RSUI/RDRP | | DR 1.1 | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | | | | | | | | | | | | | +|-------------|----------------|-------------------|--------------------|-----------------|----------------------|-------------|----------|-----------------|----------------------|-------------|---------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------| +| Event | | | DR 5.1 | | | | DR 6.1 | | | | DR 7.1 | | | | DR 8.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CAPAB DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CAPAB DATA RESP | (-----) | | | | START T1 | S-RSUI/RDCLP | | DR 1.1 | (-----) | | | | (-----) | | | | +| | | T-CON IND | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | T-DISCON IND | | | S-P-ABT IND | 0.1 | | | S-P-ABT IND | 0.1 | STOP T1 | | S-P-ABT IND | 0.1 | | | S-P-ABT IND | 0.1 | +| | | T-EXPT IND | | | S-P-EXPT IND (ERR) 3 | DR 5.1 | | | S-P-EXPT IND (ERR) 3 | DR 6.1 | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSS | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSSP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSSN | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | + +TABLE H.2/T.62 (continued) + +### State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | | | | | | | | | | | | | +|-------------|----------------|-------------------|--------------------|-----------------|-----------------------|-------------|----------|-----------------|-----------------------|-------------|---------|-----------------|---------------------|-------------|--------|-----------------|---------------------|-------------| +| Event | | | DR 5.1 | | | | DR 6.1 | | | | DR 7.1 | | | | DR 8.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSE | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSEP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSA | | | | S-ABT IND | 7.1 | | | S-ABT IND | 7.1 | STOP T1 | | S-ABT IND | 7.1 | | | S-ABT IND | 7.1 | +| | R-RSAP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSCC | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSCCP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/ CDS | | START T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | START T1 | S-RSUI/ RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | | | | | | | S-P-EXPT IND (FAIL) | x | +| | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | DR 7.1 | | | | | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | | | | | | | | | | | | | +|-------------|---------------------|-------------------|--------------------|-----------------|-----------------------|-------------|----------|-----------------|-----------------------|-------------|---------|-----------------|---------------------|-------------|--------|-----------------|---------------------|-------------| +| Event | | | DR 5.1 | | | | DR 6.1 | | | | DR 7.1 | | | | DR 8.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/<br>CDC (C) | | START T1 | S-RSUI/<br>RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | START T1 | S-RSUI/<br>RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | | | | DR 7.1 | | | S-P-EXPT IND (FAIL) | x | +| | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | | | | | | +| | R-CSUI/<br>CDCL | | START T1 | S-RSUI/<br>RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | START T1 | S-RSUI/<br>RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | | | | DR 7.1 | | | S-P-EXPT IND (FAIL) | x | +| | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | | | | | | +| | R-RSUI/<br>RDCLP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-CSUI/<br>CDE (I) | | START T1 | S-RSUI/<br>RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | START T1 | S-RSUI/<br>RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | | | | DR 7.1 | | | S-P-EXPT IND (FAIL) | x | +| | | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | | | | | | +| | R-RSUI/<br>RDEP (K) | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | + +TABLE H.2/T.62 (continued) + +### State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | | | | | | | | | | | | | +|-------------|-----------------|-------------------|--------------------|-----------------|-----------------------------|-------------|-------------|-----------------|-----------------------------|-------------|------------|-----------------|---------------------------|-------------|--------|-----------------|---------------------------|-------------| +| Event | | | DR 5.1 | | | | DR 6.1 | | | | DR 7.1 | | | | DR 8.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/<br>CDD | | | | S-ACT<br>DCAD IND | DR 9.1 | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | | | S-ACT<br>DCAD IND | DR 9.1 | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | | | | | | | | | S-P-EXPT IND<br>(FAIL) | x | STOP<br>T1 | | | | | | | | +| | R-RSUI/<br>RDDP | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>CDR | | | | S-ACT<br>INT IND | DR 8.1 | | | S-ACT<br>INT IND | DR 8.1 | STOP<br>T1 | | S-ACT<br>INT IND | DR 8.1 | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-RSUI/<br>RDRP | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | R-CSUI/<br>CDUI | | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | START<br>T1 | S-RSUI/<br>RDGR | S-P-EXPT<br>IND<br>(ERR) 3) | DR 7.1 | | | | DR 7.1 | | | S-P-EXPT<br>IND<br>(FAIL) | x | +| | | | | | S-P-EXPT IND<br>(FAIL) | x | | | S-P-EXPT IND<br>(FAIL) | x | | | | | | | | | +| | R-RSUI/<br>RDGR | | | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | STOP<br>T1 | | S-P-EXPT<br>IND<br>(FAIL) | x | | | S-P-EXPT<br>IND<br>(FAIL) | x | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | | | | | | | | | | | | | +|-------------|-----------------------------------------|-------------------|--------------------|-----------------|-----------------------|-------------|----------|-----------------|-----------------------|-------------|---------|-----------------|---------------------|-------------|--------|-----------------|---------------------|-------------| +| Event | | | DR 5.1 | | | | DR 6.1 | | | | DR 7.1 | | | | DR 8.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/<br>CDPB (I) | | (-----) | | | | START T1 | S-RSUI/<br>RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | | | | | | | S-P-EXPT IND (FAIL) | x | +| | | | START T1 | S-RSUI/<br>RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | | | S-P-EXPT IND (FAIL) | x | | | | DR 7.1 | | | | | +| | | | | | S-P-EXPT IND (FAIL) | x | | | | | | | | | | | | | +| | R-RSUI/<br>RDPBP (K) | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | R-RSUI/<br>RDPBN | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| | ANY OTHER DOCUMENT COMMAND OR RESP | | START T1 | S-RSUI/<br>RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | START T1 | S-RSUI/<br>RDGR | S-P-EXPT IND (ERR) 3) | DR 7.1 | | | | | | | S-P-EXPT IND (FAIL) | x | +| | OR WRONG FORMAT IN CONNECTION WITH CSUI | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | DR 7.1 | | | | | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | | | | | | | | | | | | | +|--------------|-------------------------------------------|-------------------|--------------------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------| +| | | | DR 5.1 | | | | DR 6.1 | | | | DR 7.1 | | | | DR 8.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | ANY OTHER COMMAND OR RESP OR WRONG FORMAT | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T1 | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | +| EXPIRY OF T1 | | | (-----) | | | | (-----) | | | | STOP T1 | | S-P-EXPT IND (FAIL) | x | (-----) | | | | +| EXPIRY OF T2 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| EXPIRY OF T3 | | | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | Wait | | | | Wait | | | | Wait | | | | +|-------------|----------------|---------------------|--------------------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------| +| Event | | | DR 9.1 | | | | 3.1 | | | | 6.1 | | | | 14.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CON RESP POS | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CON RESP NEG | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-REL RESP | (-----) | | | | (-----) | | | | START T1 | S-RSEP | | 0.2 | (-----) | | | | +| | | S-CTRL GIVE REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CTRL GIVE RESP | (-----) | | | | | S-RSCCP | | DS 1.1 | (-----) | | | | (-----) | | | | +| | | S-SYNC MIN REQ (I) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-SYNC MIN RESP (K) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-U-EXPT REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT END REQ (I) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | Wait | | | | Wait | | | | Wait | | | | +|-------------|----------------|--------------------------|--------------------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|----------|-----------------|-------------------|-------------|---------|-----------------|-------------------|-------------| +| Event | | | DR 9.1 | | | | 3.1 | | | | 6.1 | | | | 14.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-ACT END RESP (K) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-U-ABT REQ | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | START T3 | S-CSA | | 14.1 | (-----) | | | | +| | | S-U-ABT RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT BEG (START) REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT BEG (CONT) REQ (C) | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT DCAD REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT DCAD RESP | START T1 | S-RSUI/ RDDP | | DR 1.1 | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT INT REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-ACT INT RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | + +TABLE H.2/T.62 (continued) + +### State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | Wait | | | | Wait | | | | Wait | | | | +|-------------|----------------|-------------------|--------------------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------|---------|-----------------|---------------------|-------------|---------|-----------------|-------------------|-------------| +| Event | | | DR 9.1 | | | | 3.1 | | | | 6.1 | | | | 14.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | | S-CAPAB DATA REQ | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | S-CAPAB DATA RESP | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | T-CON IND | (-----) | | | | (-----) | | | | (-----) | | | | (-----) | | | | +| | | T-DISCON IND | | | S-P-ABT IND | 0.1 | | | S-P-ABT IND | 0.1 | | | S-P-ABT IND | 0.1 | STOP T3 | | S-P-ABT IND | 0.1 | +| | | T-EXPT IND | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-CSS | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-RSSP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-RSSN | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-CSE | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | Wait | | | | Wait | | | | Wait | | | | +|-------------|-----------------|-------------------|--------------------|-----------------|---------------------|-------------|-------|-----------------|---------------------|-------------|-------|-----------------|---------------------|-------------|---------|-----------------|-------------------------|-------------| +| Event | | | DR 9.1 | | | | 3.1 | | | | 6.1 | | | | 14.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-RSEP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-CSA | | | | S-ABT IND | 7.1 | | | S-ABT IND | 7.1 | | | S-ABT IND | 7.1 | | | | 14.1 | +| | R-RSAP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | STOP T3 | | S-ABT CONF | 0.2<br>7) | +| | | | | | | | | | | | | | | | | | S-ABT CONF T-DISCON REQ | 0.1 | +| | R-CSCC | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-RSCCP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-CSUI/ CDS | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-CSUI/ CDC (C) | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | + +TABLE H.2/T.62 (continued) +**State transition tables for called terminal** + +Called terminal + +| State | | | 2 Document receive | | | | Wait | | | | Wait | | | | Wait | | | | +|-------------|-----------------|-------------------|--------------------|-----------------|---------------------|-------------|-------|-----------------|---------------------|-------------|-------|-----------------|---------------------|-------------|-------|-----------------|-------------------|-------------| +| Event | | | DR 9.1 | | | | 3.1 | | | | 6.1 | | | | 14.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/CDCL | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-RSUI/RDCPL | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-CSUI/CDE (I) | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-RSUI/RDEP (K) | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-CSUI/CDD | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-RSUI/RDDP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | + +TABLE H.2/T.62 (continued) + +### State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | Wait | | | | Wait | | | | Wait | | | | +|-------------|------------------|-------------------|--------------------|-----------------|---------------------|-------------|-------|-----------------|---------------------|-------------|-------|-----------------|---------------------|-------------|-------|-----------------|-------------------|-------------| +| Event | | | DR 9.1 | | | | 3.1 | | | | 6.1 | | | | 14.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/CDR | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-RSUI/RDRP | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-CSUI/CDUI | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-RSUI/RDGR | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-CSUI/CDPB (I) | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-RSUI/RDPBP (K) | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| | R-RSUI/RDPBN | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | + +TABLE H.2/T.62 (continued) +State transition tables for called terminal + +Called terminal + +| State | | | 2 Document receive | | | | Wait | | | | Wait | | | | Wait | | | | +|--------------|-------------------------------------------|-------------------|--------------------|-----------------|---------------------|-------------|-------------|-----------------|---------------------|-------------|-------------|-----------------|---------------------|-------------|-------------|-----------------|--------------------------|-------------| +| Event | | | DR 9.1 | | | | 3.1 | | | | 6.1 | | | | 14.1 | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | Timer | Protocol action | Service primitive | Final state | +| | ANY OTHER COMMAND OR RESP OR WRONG FORMAT | | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | S-P-EXPT IND (FAIL) | x | | | | 14.1 | +| EXPIRY OF T1 | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| EXPIRY OF T2 | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | +| EXPIRY OF T3 | | | (- - - - -) | | | | (- - - - -) | | | | (- - - - -) | | | | STOP T3 | | S-P-ABT IND T-DISCON REQ | 0.1 | + +TABLE H.2/T.62 (*continued*) +**State transition tables for called terminal** + +Called terminal + +| State | | | Wait | | | | +|-------------|----------------|---------------------------|-------------|-----------------|-------------------|-------------| +| | | | x | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | +| | | S-CON<br>RESP POS | (-----) | | | | +| | | S-CON<br>RESP NEG | (-----) | | | | +| | | S-REL<br>RESP | (-----) | | | | +| | | S-CTRL<br>GIVE REQ | (-----) | | | | +| | | S-CTRL<br>GIVE RESP | (-----) | | | | +| | | S-SYNC<br>MIN<br>REQ (I) | (-----) | | | | +| | | S-SYNC<br>MIN RESP<br>(K) | (-----) | | | | +| | | S-U-EXPT<br>REQ | (-----) | | | | +| | | S-ACT END<br>REQ (I) | (-----) | | | | +| | | S-ACT END<br>RESP (K) | (-----) | | | | +| | | S-U-ABT<br>REQ | START<br>T3 | S-CSA | | 14.1 | + +TABLE H.2/T.62 (*continued*) +**State transition tables for called terminal** + +Called terminal + +| State | | | Wait | | | | +|-------------|----------------|--------------------------|---------|-----------------|-------------------|-------------| +| | | | x | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | +| | | S-U-ABT RESP | (-----) | | | | +| | | S-ACT BEG (START) REQ | (-----) | | | | +| | | S-ACT BEG (CONT) REQ (C) | (-----) | | | | +| | | S-DATA REQ | (-----) | | | | +| | | S-ACT DCAD REQ | (-----) | | | | +| | | S-ACT DCAD RESP | (-----) | | | | +| | | S-ACT INT REQ | (-----) | | | | +| | | S-ACT INT RESP | (-----) | | | | +| | | S-CAPAB DATA REQ | (-----) | | | | +| | | S-CAPAB DATA RESP | (-----) | | | | +| | | T-CON IND | (-----) | | | | + +TABLE H.2/T.62 (continued) +**State transition tables for called terminal** + +Called terminal + +| State | | | Wait | | | | +|-------------|----------------|-------------------|-------|-----------------|-------------------|-------------| +| Event | | | x | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | +| | | T-DISCON IND | | | S-P-ABT IND | 0.1 | +| | | T-EXPT IND | | | | x | +| | R-CSS | | | | | x | +| | R-RSSP | | | | | x | +| | R-RSSN | | | | | x | +| | R-CSE | | | | | x | +| | R-RSEP | | | | | x | +| | R-CSA | | | | S-ABT IND | 7.1 | +| | R-RSAP | | | | | x | +| | R-CSCC | | | | | x | +| | R-RSCCP | | | | | x | + +TABLE H.2/T.62 (*continued*) +**State transition tables for called terminal** + +Called terminal + +| State | | | Wait | | | | +|-------------|---------------------|-------------------|-------|-----------------|-------------------|-------------| +| | | | x | | | | +| Event | | | | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | +| | R-CSUI/<br>CDS | | | | | x | +| | R-CSUI/<br>CDC (C) | | | | | x | +| | R-CSUI/<br>CDCL | | | | | x | +| | R-RSUI/<br>RDCLP | | | | | x | +| | R-CSUI/<br>CDE (I) | | | | | x | +| | R-RSUI/<br>RDEP (K) | | | | | x | +| | R-CSUI/<br>CDD | | | | | x | +| | R-RSUI/<br>RDDP | | | | | x | +| | R-CSUI/<br>CDR | | | | | x | +| | R-RSUI/<br>RDRP | | | | | x | +| | R-CSUI/<br>CDUI | | | | | x | + +TABLE H.2/T.62 (*end*) +**State transition tables for called terminal** + +Called terminal + +| State<br>Event | | | Wait | | | | +|-----------------|-------------------------------------------------------|-------------------|---------|-----------------|-------------------|-------------| +| | | | x | | | | +| Local event | Protocol event | Service primitive | Timer | Protocol action | Service primitive | Final state | +| | R-RSUI/<br>RDGR | | | | | x | +| | R-CSUI/<br>CDPB (I) | | | | | x | +| | R-RSUI/<br>RDPBP (K) | | | | | x | +| | R-RSUI/<br>RDPBN | | | | | x | +| | ANY OTHER<br>COMMAND<br>OR RESP<br>OR WRONG<br>FORMAT | | | | | x | +| EXPIRY<br>OF T1 | | | (.....) | | | | +| EXPIRY<br>OF T2 | | | (.....) | | | | +| EXPIRY<br>OF T3 | | | (.....) | | | | \ No newline at end of file diff --git a/marked/T/T-REC-T.621-201703-I_PDF-E/raw.md b/marked/T/T-REC-T.621-201703-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..6059db8b7fbfcfda6365492888d48c82ef8473e3 --- /dev/null +++ b/marked/T/T-REC-T.621-201703-I_PDF-E/raw.md @@ -0,0 +1,678 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**T.621** + +(03/2017) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES +General multimedia application frameworks + +# --- **File structure for interactive mobile comic and animation content** + +Recommendation ITU-T T.621 + +![ITU logo](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with a red lightning bolt striking it, and the text "ITU" in blue, with "International Telecommunication Union" in smaller blue text below it. + +ITU logo + +## ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES** + +| | | +|-----------------------------------------------------|--------------------| +| Facsimile – Framework | T.0–T.19 | +| Still-image compression – Test charts | T.20–T.29 | +| Facsimile – Group 3 protocols | T.30–T.39 | +| Colour representation | T.40–T.49 | +| Character coding | T.50–T.59 | +| Facsimile – Group 4 protocols | T.60–T.69 | +| Telematic services – Framework | T.70–T.79 | +| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89 | +| Telematic services – ISDN Terminals and protocols | T.90–T.99 | +| Videotext – Framework | T.100–T.109 | +| Data protocols for multimedia conferencing | T.120–T.149 | +| Telewriting | T.150–T.159 | +| Multimedia and hypermedia framework | T.170–T.189 | +| Cooperative document handling | T.190–T.199 | +| Telematic services – Interworking | T.300–T.399 | +| Open document architecture | T.400–T.429 | +| Document transfer and manipulation | T.430–T.449 | +| Document application profile | T.500–T.509 | +| Communication application profile | T.510–T.559 | +| Telematic services – Equipment characteristics | T.560–T.619 | +| <b>General multimedia application frameworks</b> | <b>T.620–T.649</b> | +| Still-image compression – JPEG 2000 | T.800–T.829 | +| Still-image compression JPEG XR | T.830–T.849 | +| Still-image compression – JPEG-1 extensions | T.850–T.899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## Recommendation ITU-T T.621 + +# File structure for interactive mobile comic and animation content + +## Summary + +Recommendation ITU-T T.621 defines an interactive mobile comic and animation file structure used for organization and storage of mobile animation contents. It consists of a header, a resource file list, an asset list, an index of all movies and a movie list that contains animation and interactive attributes. This Recommendation can be used as a guideline for creation, processing, transmission and play of mobile animation contents. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T T.621 | 2017-03-01 | 16 | <a href="http://handle.itu.int/11.1002/1000/13240">11.1002/1000/13240</a> | + +## Keywords + +Animation, comic, file structure, interactive, mobile. + +--- + +\* To access the Recommendation, type the URL <http://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID. For example, <http://handle.itu.int/11.1002/1000/11830-en>. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at <http://www.itu.int/ITU-T/ipr/>. + +© ITU 2017 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | Page | +|------------------------------------------------|------| +| 1 Scope..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this recommendation ..... | 1 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Data types ..... | 2 | +| 7 File structure ..... | 2 | +| 7.1 File name extension..... | 2 | +| 7.2 Basic file structure ..... | 2 | +| 7.3 Header..... | 3 | +| 7.4 Resource file list ..... | 4 | +| 7.5 Asset list ..... | 4 | +| 7.6 Movie index..... | 10 | +| 7.7 Movie list..... | 11 | +| Appendix I – Behaviour list..... | 15 | +| Appendix II – Action list ..... | 16 | + + + +## Recommendation ITU-T T.621 + +# File structure for interactive mobile comic and animation content + +## 1 Scope + +This Recommendation defines an interactive mobile animation file structure used for organization and storage of mobile animation files. + +## 2 References + +The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is published regularly. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +[IETF RFC 1321] IETF RFC 1321 (1992), *The MD5 Message-Digest Algorithm*. +<https://tools.ietf.org/html/rfc1321> + +[ISO/IEC 16262] ISO/IEC 16262:2011, *Information technology – Programming languages, their environments and system software interfaces – ECMAScript language specification*. <https://www.iso.org/standard/55755.html> + +## 3 Definitions + +### 3.1 Terms defined elsewhere + +None. + +### 3.2 Terms defined in this recommendation + +This Recommendation defines the following terms: + +**3.2.1 action:** The changes caused by user behaviour that can be used as outputs of an action track. + +**3.2.2 animation object:** An object that contains an asset and the information of its changes over time. + +**3.2.3 asset:** A digital material used to make animations, including bitmaps, vector diagrams, texture, subtexture, sound or movie clips. + +**3.2.4 behaviour:** User interactions that can be used as inputs of an action track. + +**3.2.5 movie clip:** A container that can hold one or more animation objects. + +**3.2.6 subtexture:** A part of texture that can be used independently. A subtexture contains information about its size and offset position in a texture. + +**3.2.7 texture:** A bitmap image that can be applied to a surface in computer graphics. + +**3.2.8 track:** A set of data that describes the changes of a single attribute in an animation object. + +## 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|------|-----------------------------------------| +| GPS | Global Positioning System | +| ID | Identification | +| JSON | JavaScript Object Notation | +| MACF | Mobile Animation and Comic File Formats | +| MD5 | Message-Digest Algorithm 5 | + +## 5 Conventions + +The file structure described in this Recommendation is called mobile animation and comic file formats (MACF). + +## 6 Data types + +The data types used in the animation file structure are listed as follows: + +| | | +|---------|-------------------------------------------------------------------------------------------| +| NUMBER | Numeric type. Double-precision floating-point data type. | +| BOOLEAN | Boolean type. The value is either true or false. | +| STRING | String type. The string length can be 0. | +| ARRAY | Array type. An array is a collection of data elements that are sorted in a certain order. | +| OBJECT | Object type. The object type contains the data type of the subfields. | + +## 7 File structure + +This clause defines file structure. Data in the file structure is carried in key/value pairs. The recommended file format is JavaScript object notation (JSON) that is defined in [ISO/IEC 16262]. + +### 7.1 File name extension + +The recommended file name extension is mobile animation and comic file formats (MACF). + +### 7.2 Basic file structure + +A file consists of a header, a resource file list, the index to a movie in the asset list and one or more movie markers as shown in Figure 1. + +![Diagram illustrating the structure of the file body. The file is divided into sections: Header, Resource file list, Asset list, Movie index, and Movie list. The Movie list contains Movie 1, Movie 2, ..., and Movie N. Arrows indicate that the Movie index points to the start of the Movie list, and the Movie list contains the actual movie data.](18f841ac4f2ef28f34a026f1bdc5af9a_img.jpg) + +The diagram shows a horizontal bar representing a file. It is divided into several sections: 'Header', 'Resource file list', 'Asset list', 'Movie index', and 'Movie list'. The 'Movie list' section is further divided into 'Movie 1', 'Movie 2', '...', and 'Movie N'. Arrows indicate that the 'Movie index' points to the start of the 'Movie list', and the 'Movie list' contains the actual movie data. + +Diagram illustrating the structure of the file body. The file is divided into sections: Header, Resource file list, Asset list, Movie index, and Movie list. The Movie list contains Movie 1, Movie 2, ..., and Movie N. Arrows indicate that the Movie index points to the start of the Movie list, and the Movie list contains the actual movie data. + +T.621(17)\_F01 + +**Figure 1 – Structure of the file body** + +### 7.3 Header + +The header describes basic information about the file. Description attributes include, inter alia, file name, author, keywords and description. + +The key of the header is "head" and the value is an object. Table 1 describes the structure of the head field. + +**Table 1 – Structure of header** + +| Field | Type | Mandatory (Y/N) | Description | +|-------|--------|-----------------|----------------------------------------------------------------------| +| head | OBJECT | Y | The head field contains relevant information about the file content. | + +Table 2 describes the attributes of the header object. + +**Table 2 – Attributes of header object** + +| Field | Type | Mandatory (Y/N) | Description | +|-------------|--------|-----------------|----------------------------------------------------------------------------------------------------------------------| +| version | STRING | Y | Major version of the file in MACF format. Backward compatibility cannot be ensured if the major version changes. | +| subVersion | STRING | Y | Minor version of the file in the MACF format. Backward compatibility cannot be ensured if the minor version changes. | +| name | STRING | Y | Official name of the item corresponding to the file. | +| volumeCount | STRING | Y | Total number of episodes of the item corresponding to the file. | +| volume | STRING | Y | Current episode of the item corresponding to the file. | +| keyword | ARRAY | Y | Keywords of the item corresponding to the file, separated by comma (,). | +| language | STRING | Y | Language used in the item corresponding to the file, such as Chinese or English. | +| description | STRING | Y | Detailed description of the item corresponding to the file. | +| author | ARRAY | Y | Names and detailed description of the company and persons creating the file. | +| date | STRING | Y | Date when the file is created. | +| producer | ARRAY | Y | Names and detailed description of the company and persons producing the file. | +| produceDate | STRING | Y | Date when the file is produced. | +| publisher | ARRAY | Y | The name and detailed description of the company publishing the file. | +| publishDate | STRING | Y | Date when the file is published. | +| copyright | STRING | Y | Copyright statement of the file. | + +### 7.4 Resource file list + +The resource file list is an array that contains all asset data required in a movie. The key of the resource file list is "files" and the value is an array. Each item in the array is an object. The resource file object contains the file data, including the path and data of the file. Generally, data is in a binary format. Following this standard, binary data is converted into string data in Base64 mode. Hash data is a string obtained by converting the binary data of the resource file by using the MD5 algorithm. The hash string is used to verify the data integrity of the resource file. Table 3 describes the structure of the resource file list and Table 4 describes the relevant attributes. + +There is no limitation for supported resource file types in this Recommendation. + +**Table 3 – Structure of resource file list** + +| Field | Value type | Mandatory (Y/N) | Description | +|-------|------------|-----------------|-------------------------------------------------------------------| +| files | Array | Y | All resource file data used in the movie as described in Table 4. | + +**Table 4 – Attributes of a single resource file** + +| Field | Value type | Mandatory (Y/N) | Description | +|-------|------------|-----------------|------------------------------------------------------------------------------------------------------| +| id | STRING | Y | Unique identifier of the resource file. | +| path | STRING | Y | The path of the resource file. | +| data | STRING | Y | Binary data of the resource file in the form of a string | +| hash | STRING | Y | Hash string obtained by converting the binary data using the MD5 algorithm to verify data integrity. | + +### 7.5 Asset list + +The asset list is an array that contains all assets required in the movie. Assets are packaged resource file data. The key of the asset list is the "assets" field and the value is an array that contains all assets. Table 5 describes the structure of the asset list. + +**Table 5 – Data structure of asset list (file information)** + +| Field | Value type | Mandatory (Y/N) | Description | +|--------|------------|-----------------|----------------------------------------------------------------------------------------------| +| assets | Array | Y | All asset data used in the movie. Table 6 describes the structure of each item in the array. | + +Table 6 describes the structure of a single asset. + +**Table 6 – Data structure of one asset** + +| Field | Value type | Mandatory (Y/N) | Description | +|-----------------|------------|-----------------|-------------------------------------------------------------------------------------------------------------------------------------| +| id | STRING | Y | Unique identifier. | +| type | STRING | Y | Asset type. Different types of assets have different attributes. | +| fileId | ARRAY | Y | Unique identifier of the resource file used by the current asset. | +| asset attribute | – | Y | The attribute list varies with the asset type. Tables 7, 8, 9, 10, 11 and 12 define the asset attributes for different asset types. | + +#### 7.5.1 Asset type + +There are four types of asset: picture, texture, sound and movie clip. + +#### 7.5.2 Picture attributes + +Pictures contain a number of attributes, some of which are mandatory and some which are not. If an attribute is not set, the default value prevails. All optional attributes have default values. + +A mask is a graphic. If the mask attribute of a picture is not null, the picture will be displayed in the area of the mask graphic and will not be displayed outside the area thereof. A mask is represented in an array that contains the coordinates of multiple points. A mask indicates a graphic formed by connecting all points. For example, mask:[0,0,100,0,100,100,0,100] indicates a square with a width and height of 100. + +Table 7 describes the complete list of attributes of a picture. + +**Table 7 – Picture attributes** + +| Field | Value type | Mandatory (Y/N) | Description | +|--------|------------|-----------------|------------------------------------------------------------------------------------------------------------------------------------| +| width | NUMBER | Y | Width of the picture, in pixels. | +| height | NUMBER | Y | Height of the picture, in pixels. | +| pivotX | NUMBER | N | X coordinate of the pivot. The default value is half of the width. | +| pivotY | NUMBER | N | Y coordinate of the pivot. The default value is half of the height. | +| mask | ARRAY | N | A mask, indicating the shape of the mask layer of the picture. It is represented in a series of points. The default value is null. | +| zOrder | NUMBER | Y | The layer of the picture. A lower-layer picture will be covered by an upper-layer picture. | +| path | ARRAY | N | The path, described in a Bezier curve. The default value is null. | +| x | NUMBER | N | X coordinate of the picture. The default value is 0. | +| y | NUMBER | N | Y coordinate of the picture. The default value is 0. | + +**Table 7 – Picture attributes** + +| Field | Value type | Mandatory (Y/N) | Description | +|----------|------------|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| scaleX | NUMBER | N | Scale of the picture in the X direction. The default value is 1. | +| scaleY | NUMBER | N | Scale of the picture in the Y direction. The default value is 1. | +| rotation | NUMBER | N | Rotation angle of the picture. The default value is 0. | +| skewX | NUMBER | N | Skew of the picture in the X direction. The rotation angle of a picture can be represented by the skew in the X and Y directions. Therefore, the skew attributes and the rotation angle are mutually exclusive. The default value is 0. | +| skewY | NUMBER | N | Skew of the picture in the Y direction. The default value is 0. | +| blend | STRING | N | Blend mode of the picture with lower-layer pictures. The default value is normal. | +| visible | BOOL | N | Whether the picture is visible or not. The default value is true. | +| alpha | NUMBER | N | The range of Alpha value is 0-1. The value 0 indicates full transparency and the value 1 indicates opacity. The default value is 1. | + +#### 7.5.3 Texture attributes + +The texture refers to a picture that is composed of multiple smaller pictures arranged in a certain manner. Each small picture is a subtexture. A texture consists of one or more subtextures. If a subtexture is surrounded by many transparent areas, these areas can be cut when forming a texture to save space. Figure 2 shows the meaning of each attribute of a subtexture. The key of a texture is "subTexture" and the value is an array. Each item in the array is an attribute of the subtexture. + +![Figure 2: Texture and subtexture. The image shows a large texture composed of many small subtextures. A red box highlights one subtexture, which is then shown in a larger, detailed view on the right. The detailed view shows a green, flame-like subtexture within a grid. The grid has a coordinate system with (0,0) at the top-left corner and (frame X, frame Y) at the top-right corner. The subtexture is defined by its width and height, which are also labeled as frame width and frame height respectively.](4d2624b1b2871a23382b647cd71e1c1c_img.jpg) + +The diagram illustrates the relationship between a texture and its subtextures. On the left, a collection of various subtextures (like dragon parts) is shown as a single texture. A red box highlights one specific subtexture. On the right, this subtexture is shown in detail, overlaid on a grid. The grid's origin is marked as (0,0) at the top-left corner, and a point (frame X, frame Y) is marked at the top-right corner. The subtexture itself is a green flame-like shape. Red arrows indicate the 'Width' and 'Height' of the subtexture, which are also labeled as 'Frame width' and 'Frame height' respectively, spanning from the origin to the subtexture's dimensions. + +Figure 2: Texture and subtexture. The image shows a large texture composed of many small subtextures. A red box highlights one subtexture, which is then shown in a larger, detailed view on the right. The detailed view shows a green, flame-like subtexture within a grid. The grid has a coordinate system with (0,0) at the top-left corner and (frame X, frame Y) at the top-right corner. The subtexture is defined by its width and height, which are also labeled as frame width and frame height respectively. + +**Figure 2 – Texture and subtexture** + +Table 8 describes the structure of a texture and Table 9 describes the attributes of a subtexture. + +**Table 8 – Texture structure** + +| Field | Value type | Mandatory (Y/N) | Description | +|------------|------------|-----------------|--------------------------------------------------------------------------------------------------------------------------| +| subTexture | ARRAY | Y | A subtexture represents a picture contained in a texture. For details about the attributes of a subtexture, see Table 9. | + +**Table 9 – Subtexture attributes** + +| Field | Value type | Mandatory (Y/N) | Description | +|-------------|------------|-----------------|----------------------------------------------------------------------| +| name | STRING | Y | Subtexture name. | +| height | NUMBER | Y | Height of the subtexture with transparent areas removed. | +| width | NUMBER | Y | Width of the subtexture with transparent areas removed. | +| X | NUMBER | Y | Position of the subtexture in the X direction of the larger picture. | +| Y | NUMBER | Y | Position of the subtexture in the Y direction of the larger picture. | +| frameX | NUMBER | N | Offset of X with transparent areas added to the subtexture. | +| frameY | NUMBER | N | Offset of Y with transparent areas added to the subtexture. | +| frameHeight | NUMBER | N | Height of the subtexture with transparent areas added. | +| frameWidth | NUMBER | N | Width of the subtexture with transparent areas added. | + +#### 7.5.4 Sound attributes + +The sound attributes include play and volume. The play attribute indicates the number of times played and the value 0 indicates a cyclical play mode. The volume attribute indicates the volume. The sound attributes are usually used together with the track. Table 10 describes the sound attributes. + +**Table 10 – Sound attributes** + +| Field | Value type | Mandatory (Y/N) | Description | +|--------|------------|-----------------|-----------------------------------------------------------------------------------------------------------------| +| play | NUMBER | N | Number of times the sound is played. The value 0 indicates a cyclical play mode. | +| volume | NUMBER | N | Volume. The value range is 0-100. The value 0 indicates no sound and the value 100 indicates the maximum sound. | + +#### 7.5.5 Movie clip attributes + +A picture or sound plus a track together form an animation object. One or multiple animation objects form a movie clip. A movie clip may contain nothing, which is referred to as a blank movie clip. A track is the data of an attribute that changes over time. Not all attributes have a track. Table 27 lists the attributes of a track. + +A movie clip is an animation object as well as a container of multiple animation objects. + +Table 11 describes the attributes of a movie clip. + +**Table 11 – Movie clip attributes** + +| Field | Value type | Mandatory (Y/N) | Description | +|----------|------------|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| children | ARRAY | | All animation objects contained in the movie clip. | +| pivotX | NUMBER | N | X coordinate of the pivot. The default value is half of the width. | +| pivotY | NUMBER | N | Y coordinate of the pivot. The default value is half of the height. | +| mask | ARRAY | N | A mask, indicating the shape of the mask layer of the picture. It is represented by a series of points. The default value is null. | +| zOrder | NUMBER | Y | The layer of the picture. A lower-layer picture will be covered by an upper-layer picture. | +| path | ARRAY | N | The path, described in a Bezier curve. The default value is null. | +| x | NUMBER | N | x coordinate of the picture. The default value is 0. | +| y | NUMBER | N | y coordinate of the picture. The default value is 0. | +| scaleX | NUMBER | N | Scale of the picture in the X direction. The default value is 1. | +| scaleY | NUMBER | N | Scale of the picture in the Y direction. The default value is 1. | +| rotation | NUMBER | N | Rotation angle of the picture. The default value is 0. | +| skewX | NUMBER | N | Skew of the picture in the X direction. The rotation angle of a picture can be represented by the skew in the X and Y directions. Therefore, the skew attributes and the rotation angle are mutually exclusive. The default value is 0. | +| skewY | NUMBER | N | Skew of the picture in the Y direction. The default value is 0. | +| blend | STRING | N | Blend mode of the picture with lower-layer pictures. The default value is normal. | +| visible | BOOL | N | Whether the picture is visible or not. The default value is true. | +| alpha | NUMBER | N | The range of the Alpha value is 0-1. The value 0 indicates full transparency and the value 1 indicates opacity. The default value is 1. | + +**Table 11 – Movie clip attributes** + +| Field | Value type | Mandatory (Y/N) | Description | +|--------------|------------|-----------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| tracks | OBJECT | Y | Track data, which is an object. The object contains one or multiple attributes. Not all attributes have a track. Table 27 lists the attributes of a track.<br>For details about the structure of a track, see Table 13. | +| actionTracks | ARRAY | N | Action track data. An action track describes the changes that occur according to user interactions. Table I.1 lists different types of user interactions. Changes caused by user interactions are called actions. Table II.1 lists different types of actions. Table 15 describes the structure of an action track. | + +Table 12 describes the attributes of an animation object. + +**Table 12 – Animation object attributes** + +| Field | Value type | Mandatory (Y/N) | Description | +|----------------|------------|-----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| assetId | STRING | Y | Unique asset identifier. The data of an asset can be located by the asset ID. The asset type can be acquired based on the asset data. | +| name | STRING | N | Name of the subtexture if the asset is a texture. | +| attribute list | – | Y | Different types of assets have different attributes. For details about the attributes of each type of asset, see Table 27. | +| tracks | OBJECT | Y | Track data, which is an object. The object contains one or multiple attributes. Not all attributes have a track. Table 27 lists the attributes of a track.<br>For details about the structure of a track, see Table 13. | +| actionTracks | ARRAY | N | Action track data. An action track describes the changes that occur according to user interactions. Table I.1 lists different types of user interactions. Changes caused by user interactions are called actions. Table II.1 lists different types of actions. | + +Table 13 describes the structure of a track. + +**Table 13 – Track structure** + +| Field | Value type | Mandatory (Y/N) | Description | +|----------------|------------|-----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| attribute name | ARRAY | Y | The attribute name varies according to the type of the animation object. For details about attributes that can have a track, see Table 27. The attribute name is the key and the value is an array. Each item in the array is a key frame. A key frame defines the value of an attribute at a specific time point. | + +Table 14 describes the attributes of a key frame. + +**Table 14 – Attributes of a key frame** + +| Field | Value type | Mandatory (Y/N) | Description | +|-------|------------|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| time | NUMBER | Y | Time position of the current key frame. | +| value | NUMBER | Y | Value of the attribute corresponding to the current key frame. | +| curve | ARRAY | N | Interpolation curve data from the current key frame to the next key frame. The default value is null. The value null indicates that the curve is a broken line, on which the attribute changes instantaneously. | + +Table 15 describes the attributes of an action track. + +**Table 15 – Attributes of an action track** + +| Field | Value type | Mandatory (Y/N) | Description | +|-----------|------------|-----------------|---------------------------------------------| +| condition | STRING | Y | Type of condition that triggers an action. | +| value | ARRAY | Y | Value of condition that triggers an action. | +| action | STRING | Y | Type of triggered action. | +| params | ARRAY | Y | Action parameter. | + +### 7.6 Movie index + +A file may contain the data of one or multiple movies. A movie index is an array. Each item in the array contains ID, storage address and duration of a movie, excluding the actual movie data. The movie index and movie data are stored separately to implement the function of playing the movie while downloading. + +A movie contains a stage. All animation objects of the movie are presented on this stage. See Figure 3. + +![Figure 3 – Stage coordinates. A diagram showing a rectangular stage on a 2D coordinate system. The origin (0, 0) is at the top-left corner. The x-axis points to the right, and the y-axis points downwards. The word 'Stage' is centered within the rectangle. The reference 'T.621(17)_F03' is located at the bottom right of the diagram.](8fbdfc3d17fb1dae7b2d8f5a287fa9fc_img.jpg) + +Figure 3 – Stage coordinates. A diagram showing a rectangular stage on a 2D coordinate system. The origin (0, 0) is at the top-left corner. The x-axis points to the right, and the y-axis points downwards. The word 'Stage' is centered within the rectangle. The reference 'T.621(17)\_F03' is located at the bottom right of the diagram. + +**Figure 3 – Stage coordinates** + +Table 16 describes the structure of a movie index array. + +**Table 16 – Movie index array** + +| Field | Value type | Mandatory (Y/N) | Description | +|------------|------------|-----------------|------------------------------------------------------------------------------------------------------------------| +| movieIndex | ARRAY | Y | Array of movie indices listed based on the play order. Table 17 describes the structure of a single movie index. | + +Table 17 describes the movie index attributes. + +**Table 17 – Movie index attributes** + +| Field | Value type | Mandatory (Y/N) | Description | +|-----------|------------|-----------------|---------------------------------------------| +| movieId | STRING | Y | Unique identifier of the movie. | +| address | NUMBER | Y | Physical offset of the content in the file. | +| totaltime | NUMBER | Y | Duration of the movie. | +| size | NUMBER | Y | Physical size of the movie in the file. | + +### 7.7 Movie list + +A movie is a special type of movie clip. Therefore, a movie has all the attributes and structures of a movie clip. The differences lie in that the attributes and track data of a movie are stored separately and track data is stored as segments based on the order of time. In this way, movies can be played while downloading. + +A movie list stores all movie data. Table 18 describes the structure of a movie list. Each item in a movie list indicates a movie. + +**Table 18 – Movie list structure** + +| Field | Value type | Mandatory (Y/N) | Description | +|--------|------------|-----------------|-------------------------------------------------| +| movies | ARRAY | Y | Array of movies listed based on the play order. | + +Table 19 describes the movie attributes. + +**Table 19 – Movie attributes** + +| Field | Value type | Mandatory (Y/N) | Description | +|----------------|------------|-----------------|---------------------------------------------------------------------------------------------------------------| +| id | STRING | Y | Unique identifier of the movie. | +| movieClipIndex | NUMBER | Y | Index information about all movie clips of the movie. Table 21 describes the structure of a movie clip index. | +| movieClips | ARRAY | Y | Information about all movie clips of the movie. | +| stream | ARRAY | Y | Track data of all movie clips of the movie, described as segments. | + +#### 7.7.1 Movie clip index + +A movie clip index is a data record that contains the index information of all movie clips. A movie clip index contains the ID, address, size and life attributes of the movie clip. The life attribute indicates the lifespan of a movie clip and is actually a miniature of the track of the movie clip. The value of the life attribute is an array, which contains the appearance and disappearance time of a movie clip on the stage. For example, life: [0,100,400,500] indicates that a movie clip appears at 0 s and disappears at 100 s, then reappears at 400 s and disappears at 500 s. + +Table 20 describes the structure of a movie clip index array. + +**Table 20 – Movie clip index array structure** + +| Field | Value type | Mandatory (Y/N) | Description | +|----------------|------------|-----------------|-------------------------------------------------------| +| movieClipIndex | ARRAY | Y | Index information about all movie clips of the movie. | + +Table 21 describes the structure of a movie clip index. + +**Table 21 – Movie clip index structure** + +| Field | Value type | Mandatory (Y/N) | Description | +|---------|------------|-----------------|---------------------------------------------| +| mcId | STRING | Y | Unique identifier of the movie clip. | +| address | NUMBER | Y | Physical offset of the content in the file. | +| size | NUMBER | Y | Content length. | +| life | ARRAY | Y | Lifespan of the movie clip. | + +#### 7.7.2 Movie clip array + +A movie clip array contains all movie clip attributes in the movie. The track information will be presented in the movie stream. Table 22 describes the attributes of a movie clip array. + +**Table 22 – Movie clip array structure** + +| Field | Value type | Mandatory (Y/N) | Description | +|------------|------------|-----------------|------------------------------------------------------------------------------------------------------------| +| movieClips | ARRAY | Y | Information about all movie clips in a movie. A movie clip contains all other attributes except the track. | + +Table 23 describes the attributes of a movie clip. + +**Table 23 – Movie clip attributes** + +| Field | Value type | Mandatory (Y/N) | Description | +|---------|------------|-----------------|-----------------------------------------------------------------------| +| id | STRING | Y | Unique identifier of the movie clip. | +| objects | ARRAY | Y | Different types have different attributes. For details, see Table 12. | + +#### 7.7.3 Movie stream array + +Table 24 describes the structure of a movie stream array. + +**Table 24 – Movie stream array structure** + +| Field | Value type | Mandatory (Y/N) | Description | +|--------|------------|-----------------|------------------------------------------| +| stream | ARRAY | Y | Track information presented in segments. | + +Table 25 describes the attributes of a movie stream. + +**Table 25 – Movie stream attributes** + +| Field | Value type | Mandatory (Y/N) | Description | +|-----------|------------|-----------------|----------------------------------| +| timeStamp | STRING | Y | Time period of the movie stream. | +| timelines | ARRAY | Y | Track data of the movie stream. | + +#### 7.7.4 Track + +Table 26 describes the structure of the track of a movie stream. + +**Table 26 – Movie stream track structure** + +| Field | Value type | Mandatory (Y/N) | Description | +|--------|------------|-----------------|--------------------------------------------------------------------------------------------------------------------| +| mcId | STRING | Y | Unique identifier of the movie clip. | +| tracks | ARRAY | Y | Track data of the movie clip. Different types of movie clips have different track data. For details, see Table 27. | + +Table 27 describes the attributes of a track. + +**Table 27 – Track attributes** + +| Asset type | Attribute | +|------------------|-----------| +| Image, MovieClip | x | +| | y | +| | scaleX | +| | scaleY | +| | Rotation | +| | skewX | +| | skewY | +| | path | +| | zOrder | +| | visible | +| | alpha | +| | event | +| Sound | play | +| | volume | + +## Appendix I + +### Behaviour list + +(This appendix does not form an integral part of this Recommendation.) + +Table I.1 contains user inputs that can trigger interaction events in mobile. + +**Table I.1 – Behaviour list** + +| Field name | Field description | Data type | Value description | +|-------------------|---------------------------------|-----------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| light_intensity | Light intensity | NUMBER | The value range is 0–100. The value 0 indicates complete darkness and 100 indicates the highest light intensity. | +| rotation | Rotation change of mobile phone | ARRAY | The value is an array of six items. Each value in the array is a number. The six values are described as follows: <ul style="list-style-type: none"> <li>– Start angle for turnover forwards or backwards.</li> <li>– End angle for turnover forwards or backwards.</li> <li>– Start angle for turnover leftwards or rightwards.</li> <li>– End angle for turnover leftwards or rightwards.</li> <li>– Start angle for horizontal rotation.</li> <li>– End angle for horizontal rotation.</li> </ul> | +| direction | Direction change | NUMBER | North-oriented clockwise offset.<br>Unit: radians. | +| location | Location detection | ARRAY | The value is an array of 5 items. The 5 values are described as follows: <ul style="list-style-type: none"> <li>– Integral part of the longitude returned by GPS.</li> <li>– Decimal part of the longitude returned by GPS.</li> <li>– Integral part of the latitude returned by GPS.</li> <li>– Decimal part of the latitude returned by GPS.</li> <li>– The longitude and latitude are determined based on the pivot, in meters.</li> </ul> | +| air_pressure | Air pressure | NUMBER | Unit: hectopascal (hPa). | +| temperature | Temperature detection | NUMBER | Unit: °C. | +| accelerator | Displacement acceleration | NUMBER | Unit: m/s <sup>2</sup> . | +| angle_accelerator | Angle acceleration | NUMBER | Unit: rad/s <sup>2</sup> . | +| gesture | Gesture | NUMBER | 1: leftwards.<br>2: rightwards.<br>3: downwards.<br>4: upwards.<br>5: long press.<br>6: tap. | + +## Appendix II + +## Action list + +(This appendix does not form an integral part of this Recommendation.) + +Table II.1 contains animation actions triggered by user inputs in mobile. + +**Table II.1 – Action list** + +| Action type name | Action type value | Data type | Action description | +|-------------------------|-------------------------------------------|-----------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| link | Link | STRING | Destination link address. | +| gotoAndPlay | Jump to a time point and continue to play | STRING | Jump to a time point and continue to play. | +| gotoAndStop | Jump to a time point and stop playing | STRING | Jump to a time point and stop playing. | +| gotoMovie | Jump to a movie and play it | STRING | Jump to a movie and play it. | +| playSound/<br>stopSound | Pause/play sound | STRING | Pause/play sound. | +| vibrate | Vibration | ARRAY | The value is an array of two items.<br>The first value in the array indicates the number of times the vibration occurs, which is mutually exclusive to the vibration duration.<br>The second value in the array indicates the vibration duration, which is mutually exclusive to the number of times the vibration occurs. | + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| <b>Series T</b> | <b>Terminals for telematic services</b> | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.627-202106-I_PDF-E/raw.md b/marked/T/T-REC-T.627-202106-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..9b5de4bf4622e0c9fd8ef6ec066be9927899459f --- /dev/null +++ b/marked/T/T-REC-T.627-202106-I_PDF-E/raw.md @@ -0,0 +1,885 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# T.627 + +(06/2021) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES +General multimedia application frameworks + +# --- Test specification for video surveillance networking + +Recommendation ITU-T T.627 + +![ITU logo](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +The logo of the International Telecommunication Union (ITU), featuring a blue globe with a network of lines and the letters 'ITU' in the center. + +ITU logo + +## ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES** + +| | | +|-----------------------------------------------------|--------------------| +| Facsimile – Framework | T.0–T.19 | +| Still-image compression – Test charts | T.20–T.29 | +| Facsimile – Group 3 protocols | T.30–T.39 | +| Colour representation | T.40–T.49 | +| Character coding | T.50–T.59 | +| Facsimile – Group 4 protocols | T.60–T.69 | +| Telematic services – Framework | T.70–T.79 | +| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89 | +| Telematic services – ISDN Terminals and protocols | T.90–T.99 | +| Videotext – Framework | T.100–T.109 | +| Data protocols for multimedia conferencing | T.120–T.149 | +| Telewriting | T.150–T.159 | +| Multimedia and hypermedia framework | T.170–T.189 | +| Cooperative document handling | T.190–T.199 | +| Telematic services – Interworking | T.300–T.399 | +| Open document architecture | T.400–T.429 | +| Document transfer and manipulation | T.430–T.449 | +| Document application profile | T.500–T.509 | +| Communication application profile | T.510–T.559 | +| Telematic services – Equipment characteristics | T.560–T.619 | +| <b>General multimedia application frameworks</b> | <b>T.620–T.649</b> | +| User interfaces - Accessibility and human factors | T.700–T.799 | +| Still-image compression – JPEG 2000 | T.800–T.829 | +| Still-image compression JPEG XR | T.830–T.849 | +| Still-image compression – JPEG-1 extensions | T.850–T.899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Recommendation ITU-T T.627 + +# Test specification for video surveillance networking + +# Summary + +Recommendation ITU-T T.627 describes the test specification for video surveillance networking. The Recommendation specifies the test objects, test classification and test tools, test environment, and test requirements that can be used for testing against ITU-T H.626 and ITU-T H.627. Recommendation ITU-T H.626 specifies the architecture of the video surveillance system, and Recommendation ITU-T H.627 specifies the signalling and protocols for a video surveillance system. + +## History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|----------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T T.627 | 2021-06-13 | 16 | <a href="http://handle.itu.int/11.1002/1000/14692">11.1002/1000/14692</a> | + +## Keywords + +Conformance test, networking, test specification, video surveillance. + +--- + +\* To access the Recommendation, type the URL <http://handle.itu.int/> in the address field of your web browser, followed by the Recommendation's unique ID. For example, <http://handle.itu.int/11.1002/1000/11830-en>. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at <http://www.itu.int/ITU-T/ipr/>. + +© ITU 2021 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | <b>Page</b> | +|-------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 References..... | 1 | +| 3 Definitions ..... | 1 | +| 3.1 Terms defined elsewhere ..... | 1 | +| 3.2 Terms defined in this Recommendation..... | 2 | +| 4 Abbreviations and acronyms ..... | 2 | +| 5 Conventions ..... | 2 | +| 6 Test objects ..... | 2 | +| 7 Test classification and test tools ..... | 3 | +| 7.1 Test classification ..... | 3 | +| 7.2 Test tools ..... | 3 | +| 8 Test environment ..... | 3 | +| 8.1 Device test environment..... | 3 | +| 8.2 Conversion gateway test environment..... | 5 | +| 8.3 Platform test environment ..... | 6 | +| 9 Test requirements ..... | 7 | +| 9.1 Test items and test methods..... | 7 | +| 9.2 Test content and test criteria..... | 7 | +| Annex A – Test items and test methods..... | 13 | +| A.1 Test of acquisition, encoding and storage devices ..... | 13 | +| A.2 Decoding device test..... | 16 | +| A.3 Conversion gateway and platform test ..... | 17 | + + + +# Recommendation ITU-T T.627 + +# Test specification for video surveillance networking + +# 1 Scope + +This Recommendation describes the test specification for video surveillance networking based on the architecture and protocols specified in [ITU-T H.626] and [ITU-T H.627]. In particular, this Recommendation specifies test objects, test classification and test tools, test environment, and test requirements. + +# 2 References + +The following ITU-T Recommendations and other references contain provisions, which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. + +- [ITU-T H.626] Recommendation ITU-T H.626 (2019), *Architectural requirements for a video surveillance system*. +- [ITU-T H.626.3] Recommendation ITU-T H.626.3 (2018), *Architecture for visual surveillance system interworking*. +- [ITU-T H.627] Recommendation ITU-T H.627 (2020), *Signalling and protocols for a video surveillance system*. + +# 3 Definitions + +## 3.1 Terms defined elsewhere + +This Recommendation uses the following terms defined elsewhere: + +**3.1.1 central control server (CCS)** [ITU-T H.626.3]: A device located at the central part of the visual surveillance system. It is used for centralized system management, service operation management and access control. + +**3.1.2 control protocol gateway (CPG)** [ITU-T H.626.3]: A gateway device located between two heterogeneous visual surveillance systems. It is used for routing, forwarding and transformation of control signals between heterogeneous visual surveillance systems. + +**3.1.3 media gateway (MG)** [ITU-T H.626.3]: A gateway device located between two heterogeneous visual surveillance systems. It is used for routing, forwarding and transformation of media between heterogeneous visual surveillance systems. + +**3.1.4 media server** [ITU-T H.626]: A device located at the centre part of a video surveillance system. It is used to forward real-time media stream as well as store, retrieve and replay historical media stream. The media server receives the media stream from premises unit or other media server and forwards the media stream to other customer unit or media server. It consists of media distribution unit and media storage unit. + +## 3.2 Terms defined in this Recommendation + +This Recommendation defines the following terms: + +**3.2.1 conversion gateway:** Device or system that converts the communication protocol, and the format of video and audio media data between a session initiation protocol (SIP) surveillance domain and a non-SIP surveillance domain, which is the combination of a unit control protocol gateway and a media gateway defined in [ITU-T H.626.3]. + +**3.2.2 standard device:** Device compliant with the provisions of [ITU-T H.626] and [ITU-T H.627], used for conformance testing of devices and platform. + +**3.2.3 video surveillance networking platform:** Platform used for centralized system management, service operation management, access control and forwarding real-time media stream, as well as storage, retrieval and replay of historical media stream, which corresponds to a unit central control server defined in [ITU-T H.626.3] and media server defined in [ITU-T H.626]. + +**3.2.4 video surveillance networking test system:** System compliant with the provisions of [ITU-T H.626] and [ITU-T H.627], used to conduct ITU-T H.626 and ITU-T H.627 conformance testing on a video surveillance networking platform, conversion gateway and main video surveillance devices in the video surveillance networking application. + +# 4 Abbreviations and acronyms + +This Recommendation uses the following abbreviations and acronyms: + +| | | +|-----|-------------------------------| +| CCS | Central Control Server | +| CPG | Control Protocol Gateway | +| DVR | Digital Video Recorder | +| ID | Identifier | +| IPC | Internet Protocol Camera | +| MG | Media Gateway | +| NVR | Network Video Recorder | +| OSD | On-Screen Display | +| PTZ | Pan/Tilt/Zoom | +| SIP | Session Initiation Protocol | +| TCP | Transmission Control Protocol | +| UDP | User Datagram Protocol | + +# 5 Conventions + +None. + +# 6 Test objects + +The test objects include the products in the video surveillance networking application. The products include the video surveillance-networking platform (hereinafter referred to as the "platform"), conversion gateway and main video surveillance devices. The main video surveillance devices include acquisition, encoding, storage, decoding and other related devices, i.e., Internet protocol camera (IPC), digital video recorder (DVR), network video recorder (NVR), encoder, decoder, etc. + +# **7 Test classification and test tools** + +## **7.1 Test classification** + +### **7.1.1 Conformance test of acquisition, encoding and storage devices** + +The conformance test of [ITU-T H.626] and [ITU-T H.627] (hereinafter referred to as "the conformance test") is carried out by connecting the tested acquisition, encoding and storage devices to the video surveillance interworking test system (hereinafter referred to as the "test system"). + +### **7.1.2 Conformance test of decoding device** + +The conformance test is carried out by connecting the tested decoding devices to the test system. + +### **7.1.3 Conformance test of conversion gateway** + +The conformance test is carried out by connecting the tested conversion gateway to the test system. + +### **7.1.4 Conformance test of platform** + +The conformance test of the platform is divided into three parts as follows. + +- 1) When the tested platform is regarded as the lower level and the test system is regarded as the upper level to carry out the conformance test, it is referred to as an "uplink test". +- 2) When the tested platform is regarded as the upper level and the test system is regarded as the lower level to carry out the conformance test, it is referred to as a "downlink test". +- 3) The standard devices are connected to the tested platform for the conformance test and it is referred to as a "device access test". + +## **7.2 Test tools** + +### **7.2.1 Test system** + +The test system is a conformance test tool. It has the service functions of registration message debugging, extended control command set message debugging, video and audio debugging, status detection, cross level forwarding message processing, link status management, subscription and notification, etc. + +The related network protocol analysis software tool installed on the test system has the functions of real-time network packet capture, network protocol analysis and statistics compilation. It aids the analysis of the signalling and media stream in the conformance test. + +### **7.2.2 Standard devices** + +Standard devices include a standard IPC, standard NVR and standard decoding device. + +# **8 Test environment** + +## **8.1 Device test environment** + +### **8.1.1 Acquisition, encoding, storage device** + +To test the acquisition, encoding and storage devices, the test system and auxiliary device should be deployed and configured in the test environment. The test objects are acquisition, encoding and storage devices. Table 8-1 describes the test environment for the acquisition, encoding and storage devices. Figure 8-1 is a device connection diagram of the acquisition, encoding, storage device conformance test. + +**Table 8-1 – Test environment for acquisition, encoding and storage devices** + +| Number | Name | Usage | Note | +|--------|----------------------------------------|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Acquisition, encoding, storage devices | Test object | Test whether the signalling a device sends and receives, and the media streams it sends, meet the relevant requirements of [ITU-T H.627]. The acquisition, encoding and storage devices should be configured with parameters such as device identifier (ID), channel ID, and alarm input device ID in accordance with [ITU-T H.626]. | +| 2 | Test system | Test tools | Used for platform, conversion gateway and main video surveillance device-related functional test. | +| 3 | Auxiliary device | Auxiliary test | A standard IPC provides a video source for an NVR; an analogue camera provides a video source for a DVR; a pan/tilt/zoom (PTZ) auxiliary device is used for the remote control functional test of the encoder and camera without PTZ; an alarm switch is used to trigger the alarm to assist in the test of alarm-related functions; audio output, audio input and front-end audio acquisition devices are used for the voice broadcasting and voice intercom-related functional test of the tested encoding device. | + +![Figure 8-1: Device connection diagram of an acquisition, encoding and storage device conformance test. The diagram shows a 'Test system' (represented by a computer tower and monitor) connected to a 'Switch'. The 'Switch' is connected to two devices: a 'Tested acquisition/encoding device' (represented by a dome camera) and a 'Tested encoding/storage device' (represented by a DVR/NVR unit). The label 'T.627(21)_F8-1' is located below the storage device.](cfda9df1319e04207eb28bcefd1dab7b_img.jpg) + +Figure 8-1: Device connection diagram of an acquisition, encoding and storage device conformance test. The diagram shows a 'Test system' (represented by a computer tower and monitor) connected to a 'Switch'. The 'Switch' is connected to two devices: a 'Tested acquisition/encoding device' (represented by a dome camera) and a 'Tested encoding/storage device' (represented by a DVR/NVR unit). The label 'T.627(21)\_F8-1' is located below the storage device. + +**Figure 8-1 – Device connection diagram of an acquisition, encoding and storage device conformance test** + +### 8.1.2 Decoding device + +To test the decoding device, the test system and monitor should be deployed and configured in the test environment. The test object is the decoding device. Table 8-2 describes the test environment for the decoding device. Figure 8-2 is a device connection diagram of the decoding device conformance test. + +**Table 8-2 – Decoding device test environment** + +| Number | Name | Usage | Note | +|--------|-----------------|-------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Decoding device | Test object | Test whether the sending and receiving signalling meets the relevant requirements of [ITU-T H.627] and the ability to decode the standard media streams. The decoding device should be configured with parameters such as decoding device ID, display ID, IP, port and password in accordance with [ITU-T H.626]. | + +**Table 8-2 – Decoding device test environment** + +| Number | Name | Usage | Note | +|--------|-------------|----------------------------------------|-------------------------------------------------------------------------------------------------------| +| 2 | Test system | Test tools | Used for the platform, conversion gateway and main video surveillance device-related functional test. | +| 3 | Monitor | Auxiliary decoding test output display | Used to view the decoded video stream. | + +![Device connection diagram of a decoding device conformance test.](e9314c83043183351ed74908e9bf2f90_img.jpg) + +``` + +graph LR + TS[Test system] --- SW[Switch] + SW --- TDD[Tested decoding device] + TDD --- MON[Monitor] + +``` + +T.627(21)\_F8-2 + +Device connection diagram of a decoding device conformance test. + +**Figure 8-2 – Device connection diagram of a decoding device conformance test** + +## 8.2 Conversion gateway test environment + +To test the conversion gateway, the test system and auxiliary device should be deployed and configured in the test environment. The test object is the conversion gateway. Table 8-3 describes the test environment of the conversion gateway. Figure 8-3 is a device connection diagram of the conversion gateway conformance test. + +**Table 8-3 – Conversion gateway test environment** + +| Number | Name | Usage | Note | +|--------|--------------------|-------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Conversion gateway | Test object | Test whether the signalling a gateway sends and receives, and the media streams it sends, meet the relevant requirements of [ITU-T H.627]. The conversion gateway should be configured with parameters such as device ID, channel ID and alarm input device ID in accordance with [ITU-T H.626]. | +| 2 | Test system | Test tools | Used for the platform, conversion gateway, and main video surveillance device-related functional test. | + +**Table 8-3 – Conversion gateway test environment** + +| Number | Name | Usage | Note | +|--------|------------------|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 3 | Auxiliary device | Auxiliary test | Acquisition, encoding and storage devices are used for video and audio on demand, video download, PTZ control and other related functional tests; an alarm switch is used to trigger the alarm to assist in the test of alarm-related functions; audio output, audio input and front-end audio acquisition devices are used for the voice broadcasting and voice intercom related functional test of the test object. | + +![Device connection diagram of a conversion gateway conformance test. It shows a 'Test system' (represented by a computer monitor and tower) connected by a line to a 'Tested conversion gateway' (represented by a server rack). Below the server rack is the label 'T.627(21)_F8-3'.](042733dc5e8e7f5f30b60adba3266cde_img.jpg) + +``` + +graph LR + TS[Test system] --- TC[Tested conversion gateway] + TC --- T627[T.627(21)_F8-3] + +``` + +Device connection diagram of a conversion gateway conformance test. It shows a 'Test system' (represented by a computer monitor and tower) connected by a line to a 'Tested conversion gateway' (represented by a server rack). Below the server rack is the label 'T.627(21)\_F8-3'. + +**Figure 8-3 – Device connection diagram of a conversion gateway conformance test** + +## 8.3 Platform test environment + +To test the platform, the test system and auxiliary device should be deployed and configured in the test environment. Table 8-4 describes the test environment description of the platform. Figure 8-4 is a device connection diagram of the platform conformance test. + +**Table 8-4 – Platform test environment** + +| Number | Name | Usage | Note | +|--------|------------------|----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | Platform | Test object | Test whether the signalling a platform sends and receives, and the media streams it sends, meet the relevant requirements of [ITU-T H.627]. | +| 2 | Test system | Test tools | Used for the platform, conversion gateway and main video surveillance device-related functional test. | +| 3 | Auxiliary device | Auxiliary test | A standard NVR is used for the video recording-related functional test; a standard IPC is used for the video source and remote control related functional test; a standard decoding device is used for the decoding-related functional test; a monitor is used to view the decoded video stream; an alarm switch is used to trigger the alarm to assist in the test of alarm-related functions; audio output, audio input and front-end audio acquisition devices are used for the voice broadcasting and voice intercom related functional test of the test object. | + +![Figure 8-4 – Device connection diagram of the platform conformance test. The diagram shows a 'Tested platform' connected to a 'Switch'. The 'Switch' is connected to four devices: 'Standard IPC', 'Standard decoding device', 'Test system', and 'Standard NVR'. The 'Standard NVR' is labeled with 'T.627(21)_F8-4' below it.](af7916c89a458fdab6c3f443217388ae_img.jpg) + +``` + +graph LR + TP[Tested platform] --- S[Switch] + S --- SIPC[Standard IPC] + S --- SDD[Standard decoding device] + S --- TS[Test system] + S --- SNVR[Standard NVR] + SNVR --- T627[T.627(21)_F8-4] + +``` + +Figure 8-4 – Device connection diagram of the platform conformance test. The diagram shows a 'Tested platform' connected to a 'Switch'. The 'Switch' is connected to four devices: 'Standard IPC', 'Standard decoding device', 'Test system', and 'Standard NVR'. The 'Standard NVR' is labeled with 'T.627(21)\_F8-4' below it. + +**Figure 8-4 – Device connection diagram of the platform conformance test** + +# 9 Test requirements + +## 9.1 Test items and test methods + +According to the functions specified in [ITU-T H.627], the conformance test is carried out for the platform, conversion gateway and main devices in the video surveillance system. The test items and test methods are specified in Annex A. + +## 9.2 Test content and test criteria + +### 9.2.1 Registration and de-registration + +For the registration and de-registration of the tested platform and tested device, the test objective is to check whether the basic registration/de-registration signalling process and content meet the requirements of clause 8.1 of [ITU-T H.627]. Table 9-1 describes the registration and de-registration tests. + +**Table 9-1 – Registration and de-registration tests** + +| Test items | Test contents | Test criteria | +|----------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------| +| Registration and de-registration | The tested platform (uplink test)/the tested device registers/de-registers with the test system; the tested platform (downlink test) accepts registration/de-registration of the test system. | The signalling process and content are correct, and registration/de-registration is successful. | + +### 9.2.2 Real-time media stream + +For the real-time media stream of a tested platform and tested device, the test objective is to check whether the signalling process and the content of requesting the real-time media stream meet the requirements of clause 8.2 of [ITU-T H.627], as well as whether the media stream meets the requirements of clause 7.6 of [ITU-T H.627]. Table 9-2 describes the real-time media stream test. + +**Table 9-2 – Real-time media stream test** + +| Test items | Test contents | Test criteria | +|------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------| +| Real-time media stream | The test system requests a real-time media stream from the tested platform (uplink test) and the tested device; the tested platform (downlink test) requests a real-time media stream from the test system. | The signalling process and content are correct, and audio and video playback formats are compliant. | + +### 9.2.3 Device control + +#### 9.2.3.1 Non-responsive device control + +For non-responsive device control of the tested platform and tested device, the test objective is to check whether the signalling process and content of the non-responsive device control meet the requirements of clause 8.3.3 of [ITU-T H.627]. Table 9-3 describes the non-responsive device control test. + +**Table 9-3 – Non-responsive device control test** + +| Test items | Test contents | Test criteria | +|-------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------| +| Non-responsive device control | The test system sends PTZ control, remote booting, mandatory key frame, zoom-in, zoom-out, PTZ precise angle control and on-screen display (OSD) configuration commands to the tested platform (uplink test) and tested device; the tested platform (downlink test) sends PTZ control, remote booting, mandatory key frame, zoom-in, zoom-out, PTZ precise angle control and OSD configuration commands to the test system. | The signalling process and content are correct, and the device control is effective. | + +#### 9.2.3.2 Responsive device control + +For responsive device control of the tested platform and tested device, the test objective is to check whether the signalling process and content of the responsive device control meet the requirements of clauses 8.3.1, 8.3.2, and 8.13 of [ITU-T H.627]. Table 9-4 describes the responsive device control test. + +**Table 9-4 – Responsive device control test** + +| Test items | Test contents | Test criteria | +|---------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------| +| Responsive device control | The test system sends recording control, guard/unguard, alarm reset, guard control, device configuration and instant image snapshot commands to the tested platform (uplink test) and tested device; the tested platform (downlink test) sends recording control, guard/unguard, alarm reset, guard control, device configuration and instant image snapshot commands to the test system. | The signalling process and content are correct, and the device control is effective. | + +### 9.2.4 Alarm event notification and distribution + +For alarm emission from the alarm device of the tested platform and the tested alarm device, the test objective is to check whether the signalling process and content of the alarm event notification and distribution meet the requirements of clause 8.4 of [ITU-T H.627], and whether the alarm parameters comply with clause A.2.5 b) of [ITU-T H.627]. Table 9-5 describes the alarm event notification and distribution test. + +**Table 9-5 – Alarm event notification and distribution test** + +| Test items | Test contents | Test criteria | +|-------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------| +| Alarm event notification and distribution | The tested platform (uplink test) and tested device send alarm event notifications to the test system; the tested platform (downlink test) receives the alarm event notification sent by the test system. | The signalling process and content are correct, and the alarm message is sent successfully. | + +### 9.2.5 Device information query + +For a device information query of the tested platform and tested device, the test objective is to check whether the signalling process and content of the device information query meet the requirements of clause 8.5 of [ITU-T H.627]. Table 9-6 describes the device information query test. + +**Table 9-6 – Device information query test** + +| Test items | Test contents | Test criteria | +|--------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------| +| Device information query | The test system sends directory query, information query, status query, configuration query and preset position query commands to the tested platform (uplink test) and tested device; the tested platform (downlink test) sends directory query, information query, status query, configuration query and preset position query commands to the test system. | The signalling process and content are correct, and the device information query is correct. | + +### 9.2.6 Status information reporting + +For status information reporting of the tested platform and tested device, the test objective is to check whether the signalling process and content of status information reporting meet the requirements of clause 8.6 of [ITU-T H.627]. Table 9-7 describes the status information-reporting test. + +**Table 9-7 – Status information-reporting test** + +| Test items | Test contents | Test criteria | +|------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------| +| Status information reporting | The tested platform (uplink test) and tested device send heartbeat status information reporting to the test system; the tested platform (downlink test) receives heartbeat status information reporting sent by the test system. | The signalling process and content are correct, and the heartbeat status information sent according to the set time interval. | + +### 9.2.7 Historical media file retrieval + +For historical media file retrieval of the tested platform and tested device, the test objective is to check whether the signalling process and content of historical media file retrieval meet the requirements of clause 8.7 of [ITU-T H.627]. Table 9-8 describes the historical media file retrieval test. + +**Table 9-8 – Historical media file retrieval test** + +| Test items | Test contents | Test criteria | +|---------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------| +| Historical media file retrieval | The tested platform (uplink test) and tested device accept the historical media file retrieval request of the test system; the tested platform (downlink test) retrieves the historical media files from the test system. | The signalling process and content are correct, and the retrieval result of the historical media file is correct. | + +### 9.2.8 Historical media file playback + +For historical media file playback of the tested platform and tested device, the test objective is to check whether the signalling process and content of historical media file playback and playback control meet the requirements of clause 8.8 of [ITU-T H.627], as well as whether the media streams meet the requirements of clause 7.6 of [ITU-T H.627]. Table 9-9 describes the historical media file playback test. + +**Table 9-9 – Historical media file playback test** + +| Test items | Test contents | Test criteria | +|--------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------| +| Historical media file playback | The test system sends historical media file playback and playback control commands to the tested platform (uplink test) and tested device; the tested platform (downlink test) sends historical media file playback and playback control commands to the test system. | The signalling process and content are correct, the format of historical media file is compliant, and the playback control is effective. | + +### 9.2.9 Historical media file download + +For historical media file download from the tested platform and tested device, the test objective is to check whether the signalling process and content of historical media file download meet the requirements of clause 8.9 of [ITU-T H.627], as well as whether the media streams meet the requirements of clause 7.6 of [ITU-T H.627]. Table 9-10 describes the historical media file download test. + +**Table 9-10 – Historical media file download test** + +| Test items | Test contents | Test criteria | +|--------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------| +| Historical media file download | The test system downloads historical media files from the tested platform (uplink test) and tested device; the tested platform (downlink test) downloads historical media files from the test system. | The signalling process and content are correct, and the historical media file is downloaded successfully. | + +### 9.2.10 Time calibration + +For time calibration of the tested platform and tested device, the test objective is to check whether the signalling process and content of time calibration meet the requirements of clause 8.10 of [ITU-T H.627]. Table 9-11 describes the time calibration test. + +**Table 9-11 – Time calibration test** + +| Test items | Test contents | Test criteria | +|------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------| +| Time calibration | The test system sends a time calibration command to the tested platform (uplink test) and tested device; the tested platform (downlink test) sends a time calibration command to the test system. | The signalling process and content are correct, and the time is calibrated successfully. | + +### 9.2.11 Subscription and notification + +#### 9.2.11.1 Directory subscription/unsubscription + +For directory subscription/unsubscription of the tested platform, the test objective is to check whether the signalling process and content of directory subscription/unsubscription between the platforms meet the requirements of clause 8.11.3 of [ITU-T H.627]. Table 9-12 describes the directory subscription/unsubscription test. + +**Table 9-12 – Directory subscription/unsubscription test** + +| Test items | Test contents | Test criteria | +|----------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------| +| Directory subscription/un-subscription | The test system sends the directory subscription/unsubscription commands to the tested platform (uplink test); the tested platform (downlink test) sends the directory subscription/unsubscription command to the test system. | The signalling process and content are correct, and the directory subscription/unsubscription between the platforms is successful. | + +#### 9.2.11.2 Directory notification + +For the directory notification of the tested platform, the test objective is to check whether the signalling process and content of directory notification between the platforms meet the requirements of clause 8.11.4 of [ITU-T H.627]. Table 9-13 describes the directory notification test. + +**Table 9-13 – Directory notification test** + +| Test items | Test contents | Test criteria | +|------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------| +| Directory notification | The tested platform (uplink test) sends a directory notification command to the test system; the tested platform (downlink test) receives the directory notification sent by the test system. | The signalling process and content are correct, and the directory notification between the platforms is effective. | + +#### 9.2.11.3 Event subscription/unsubscription + +For event subscription/unsubscription of the tested platform and tested device, the test objective is to check whether the signalling process and content of event subscription/unsubscription meet the requirements of clause 8.11.1 of [ITU-T H.627]. Table 9-14 describes the event subscription/unsubscription test. + +**Table 9-14 – Event subscription/unsubscription test** + +| Test items | Test contents | Test criteria | +|-----------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------| +| Event subscription unsubscription | The test system sends the event subscription/unsubscription command to the tested platform (uplink test) and tested device; the tested platform (downlink test) sends the event subscription/unsubscription command to the test system. | The signalling process and content are correct, and the event subscription/unsubscription is successful. | + +#### 9.2.11.4 Event notification + +For event notification of the tested platform and tested device, the test objective is to check whether the signalling process and content of event notification meet the requirements of clause 8.11.2 of [ITU-T H.627]. Table 9-15 describes of the event notification test. + +**Table 9-15 – Event notification test** + +| <b>Test items</b> | <b>Test contents</b> | <b>Test criteria</b> | +|--------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------| +| Event notification | The tested system (uplink test) and the tested device send an event notification to the test platform; the tested platform (downlink test) receives the event notification sent by the test system. | The signalling process and content are correct, and the event notification is effective. | + +### 9.2.12 Audio broadcast and audio intercom + +For audio broadcast and audio intercom of the tested platform and tested device, the test objective is to check whether the signalling process and content of audio broadcast and audio intercom meet the requirements of clause 8.12 of [ITU-T H.627], as well as whether the media streams meet the requirements of clause 7.6 of [ITU-T H.627]. Table 9-16 describes the audio broadcast and audio intercom test. + +**Table 9-16 – Audio broadcast and audio intercom test** + +| <b>Test items</b> | <b>Test contents</b> | <b>Test criteria</b> | +|------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------| +| Audio broadcast and audio intercom | The test system sends audio broadcast and audio intercom commands to the tested platform (uplink test) and tested device; the tested platform (downlink test) sends the audio broadcast and audio intercom commands to the test system. | The signalling process and content are correct, and the audio broadcast and audio intercom is effective. | + +# Annex A + +## Test items and test methods + +(This annex forms an integral part of this Recommendation.) + +## A.1 Test of acquisition, encoding and storage devices + +The test of video acquisition, encoding and storage devices is carried out according to Table A.1. + +**Table A.1 – Test of acquisition, encoding and storage devices** + +| Number | Test items | Test methods | Test tools | +|--------|---------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 1 | Tested device registration | Register the tested device on the test system; the tested device refreshes the registration before the registration expiry to check whether the signalling process and content are correct, and whether the registration is successful. | Test system | +| 2 | Tested device de-registration | De-register the tested device from the test system to check whether the signalling process and content are correct, and whether the de-registration is successful. | Test system | +| 3 | Tested device time calibration | The tested device obtains the time from the test system to check whether the time calibration is successful. | Test system | +| 4 | Tested device heartbeat | Check whether the tested device sends a heartbeat message to the registered test system according to the set time interval, and whether the signalling process and content are correct. | Test system | +| 5 | Tested device directory query | The test system queries the directory and information of the tested device to check whether the signalling process and content are correct, and whether the directory query result of the tested device is correct. | Test system | +| 6 | Tested device real-time media stream | The test system plays the video and audio stream transmitted by the tested device in real time to check whether the tested device supports transmission control protocol (TCP; active and passive connection)/user datagram protocol (UDP) media stream mode, and whether the media parameter values comply with the specification. | Test system | +| 7 | Tested device remote control | The test system remotely controls IPC and the acquisition devices connected to DVR/NVR to make up, down, left, right, zoom in, zoom out, pull frame zoom in, pull frame zoom out operations to check whether the remote control of the tested device is effective. | Test system | +| 8 | Tested device remote control cancel | The test system cancels the remote control of IPC and the acquisition devices connected to DVR/NVR to check whether the remote control cancel of the tested device is effective. | Test system | +| 9 | Tested device preset position setting | The test system sets the preset position of IPC and the acquisition devices connected to DVR/NVR to check whether the preset position setting of the tested device is effective. | Test system | + +**Table A.1 – Test of acquisition, encoding and storage devices** + +| Number | Test items | Test methods | Test tools | +|--------|------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 10 | Tested device preset position query | The test system queries the preset position of IPC and the acquisition devices connected to DVR/NVR to check whether the preset position query result of the tested device is correct. | Test system | +| 11 | Tested device preset position call | The test system calls the preset position of IPC and the acquisition devices connected to DVR/NVR to check whether the preset position call of the tested device is effective. | Test system | +| 12 | Tested device preset position cancel | The test system deletes the preset position of IPC and the acquisition devices connected to DVR/NVR to check whether preset position deletion of the tested device is successful. | Test system | +| 13 | Tested device guard control | The test system sets/cancels the guard position of IPC and the acquisition devices connected to DVR/NVR to check whether the guard control of the tested device is effective. | Test system | +| 14 | Tested device mandatory key frame | The test system sends the mandatory key frame command to the tested device to check whether the tested device sends the key frame in the video stream immediately. | Test system | +| 15 | Tested device video files retrieval | The test system retrieves the video files of the tested device to check whether the retrieval results sent by the tested device are correct; whether the retrieval result reply supports UDP and TCP transmission; whether there are replies to the message with SumNum equal to 0 when there is no video file. | Test system | +| 16 | Tested device video and audio file playback and playback control | The test system plays the video recording of the tested device back to check whether the playback control including play, pause, fast play, slow play, and random drag and drop of the tested device is effective; after playback, checks whether the tested device sends a flag of playback end; checks whether the tested device supports TCP (active and passive connection)/UDP playback mode; and whether the media parameter values comply with the specification. | Test system | +| 17 | Tested device starts manual recording | The test system sends a manual recording control command to the tested device to check whether the signalling process and content are correct, and whether the tested device starts the manual recording successfully. | Test system | +| 18 | Tested device stops manual recording | The test system sends a command to stop manual recording to the tested device to check whether the signalling process and content are correct, and whether the tested device stops the manual recording successfully. | Test system | +| 19 | Tested device guard | The test system sends a guard control command to the tested device to check whether the signalling process and content are correct, and whether the guard of the tested device is successful. | Test system | + +**Table A.1 – Test of acquisition, encoding and storage devices** + +| Number | Test items | Test methods | Test tools | +|--------|----------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 20 | Tested device unguard | The test system sends an unguard control command to the tested device to check whether the signalling process and content are correct, and whether the tested device is successfully unguarded. | Test system | +| 21 | Tested device alarm | The tested device sends alarm messages to the test system to check whether the signalling process and content are correct. | Test system | +| 22 | Tested device alarm reset | The test system sends an alarm reset command to the tested device to check whether the signalling process and content are correct, and whether the alarm reset of the tested device is successful. | Test system | +| 23 | Tested device information query | The test system sends a device information query command to the tested device to check whether the signalling process and content are correct, and whether the device information query result is correct. | Test system | +| 24 | Tested device status query | The test system sends a device status query command to the tested device to check whether the signalling process and content are correct, and whether the device status query result is correct. | Test system | +| 25 | Tested device video and audio file download | The test system sends a video and audio file download command with parameters such as download speed to the tested device to check whether the tested device returns the parameters of download speed and file size to the test system, and sends the video and audio stream; checks whether the tested device sends the download completion notification message to the test system after the download is completed; checks whether the tested device supports TCP (active and passive connection)/UDP download mode; checks whether the media parameter values comply with the specification. | Test system | +| 26 | Tested device remote booting | The test system sends the remote booting command to the tested device to check whether the signalling process and content are correct and whether the tested device is rebooted successfully. | Test system | +| 27 | Tested device registered heartbeat status detection | Check whether the tested device can determine that the test system is offline after registration failure or continuous heartbeat timeout reaches the specified number, and reinitiate registration at an interval. | Test system | +| 28 | Tested device media stream keepalive mechanism detection | After the tested device detects that the test system is offline, check whether the tested device stops sending media stream to the test system. | Test system | +| 29 | Tested device configuration acquisition | The test system sends a device basic parameter configuration acquisition command to the tested device to check whether the signalling process and content are correct, and whether the configuration acquisition of the tested device is successful. | Test system | + +**Table A.1 – Test of acquisition, encoding and storage devices** + +| Number | Test items | Test methods | Test tools | +|-------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 30 | Tested device configuration | The test system sends a device basic parameter configuration command to the tested device to check whether the signalling process and content are correct, and whether the parameter configuration of the tested device is successful | Test system | +| 31 | Tested device event subscription/ unsubscription | The test system sends an event subscription/ unsubscription command to the tested device to check whether the signalling process and content are correct, and whether the event subscription of the tested device is successful. | Test system | +| 32 | Tested device event notification | After the test system sends the event subscription to the tested device successfully, the tested device sends the event notification to the test system to check whether the signalling process and content are correct, and whether the event notification of the tested device is correct. | Test system | +| 33 | Tested device audio broadcast and audio intercom | The test system dispatches the tested device to establish a voice broadcast channel to check whether the signalling process and content are correct, and whether the voice intercom is realized, combined with the real-time media stream of the tested device. | Test system | +| 34 | Tested device image snapshot | The test system sends an instant image snapshot command to the tested device, and the tested device sends the snapshot path to the test system to check whether the signalling process and content are correct and whether the image is uploaded correctly. | Test system | +| NOTE – Test items with serial numbers 15-18, 25 and 31-34 can be selected according to the specific encoding device function. | | | | + +### A.2 Decoding device test + +The decoding device test is carried out according to Table A.2. + +**Table A.2 – Decoding device test** + +| Number | Test items | Test methods | Test tools | +|--------|--------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 1 | Tested device registration | Register the tested device on the test system, and the tested device refreshes registration before registration expiry to check whether the signalling process and content are correct, and whether the registration is successful. | Test system | +| 2 | Tested device de-registration | De-register the tested device from the test system to check whether the signalling process and content are correct, and whether the de-registration is successful. | Test system | +| 3 | Tested device time calibration | The tested device obtains the time from the test system to check whether the time calibration is successful. | Test system | + +**Table A.2 – Decoding device test** + +| Number | Test items | Test methods | Test tools | +|--------|-----------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 4 | Tested device heartbeat | Check whether the tested device sends a heartbeat message to the registered test system according to the set time interval, and whether the signalling process and content are correct. | Test system | +| 5 | Tested device directory query | The test system queries the directory and information of the tested device to check whether the signalling process and content are correct, and whether the directory query result of the tested device is correct. | Test system | +| 6 | Tested device real-time media stream | The test system plays a real-time media stream transmitted by the test system to check whether the tested device supports TCP (active and passive connection)/UDP media stream mode. | Test system | +| 7 | Tested device information query | The test system sends a device information query command to the tested device to check whether the signalling process and content are correct, and whether the device information query result is correct | Test system | +| 8 | Tested device status query | The test system sends a device status query command to the tested device to check whether the signalling process and content are correct, and whether the device status query result is correct. | Test system | +| 9 | Tested device remote booting | The test system sends a remote booting command to the tested device to check whether the signalling process and content are correct, and whether the tested device is rebooted successfully. | Test system | +| 10 | Tested device configuration acquisition | The test system sends a device basic parameter configuration acquisition command to the tested device to check whether the signalling process and content are correct, and whether the configuration acquisition of the tested device is successful. | Test system | +| 11 | Tested device configuration | The test system sends a device basic parameter configuration command to the tested device to check whether the signalling process and content are correct, and whether the parameter configuration of the tested device is successful. | Test system | + +## A.3 Conversion gateway and platform test + +The conversion gateway test is carried out according to Table A.3. The platform test is carried out according to Tables A.3 and A.4, including an uplink test (in Table A.3), a downlink test (in Table A.3), and a device access test (in Table A.4). + +**Table A.3 – Test of conversion gateway, uplink and downlink of platform** + +| Number | Test items | Test methods | Test tools | +|--------|-----------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 1 | Tested gateway/platform registration (uplink) | Register the tested gateway/platform on the test system, and the tested gateway/platform refreshes registration before registration expiry to check whether the signalling process and content are correct, and whether the registration is successful. | Test system | + +**Table A.3 – Test of conversion gateway, uplink and downlink of platform** + +| Number | Test items | Test methods | Test tools | +|--------|----------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 2 | Tested gateway/platform de-registration (uplink) | De-register the tested gateway/platform from the test system to check whether the signalling process and content are correct and whether the de-registration is successful. | Test system | +| 3 | Tested gateway/platform time calibration (uplink) | The tested gateway/platform obtains the time from the test system to check whether the time calibration is successful. | Test system | +| 4 | Tested gateway/platform heartbeat (uplink) | Check whether the tested gateway/platform sends a heartbeat message to the test system according to the set time interval, and whether the signalling process and content are correct. | Test system | +| 5 | Tested gateway/platform directory query (uplink) | The test system queries the directory of a tested gateway/platform to check whether the signalling process and content are correct, and whether the directory query result of the tested gateway/platform is correct, check whether the tested gateway/platform supports UDP, TCP method to send the directory. | Test system | +| 6 | Tested gateway/platform real-time media stream (uplink) | The test system plays a video and audio stream transmitted by a standard IPC connected to the tested gateway/platform in real time to check whether the tested gateway/platform supports TCP (active and passive connection)/UDP media stream mode, and whether the media parameters comply with the specification. | Test system | +| 7 | Tested gateway/platform remote control (uplink) | The test system remotely controls a standard IPC connected to the tested gateway/platform to make up, down, left, right, zoom in, zoom out, pull frame zoom in, pull frame zoom out operations to check whether the remote control of the tested gateway/platform is effective. | Test system | +| 8 | Tested gateway/platform remote control cancel (uplink) | The test system cancels the remote control of a standard IPC connected to the tested gateway/platform to check whether the remote control cancel of the tested gateway/platform is effective. | Test system | +| 9 | Tested gateway/platform preset position setting (uplink) | The test system sets the preset position of a standard IPC connected to the tested gateway/platform to check whether the preset position setting of the tested gateway/platform is effective. | Test system | +| 10 | Tested gateway/platform position query (uplink) | The test system queries the preset position of a standard IPC connected to the tested gateway/platform to check whether the preset position query result of the tested gateway/platform is correct. | Test system | +| 11 | Tested gateway/platform preset position call (uplink) | The test system calls the preset position of a standard IPC connected to the tested gateway/platform to check whether the preset position call of the tested gateway/platform is effective. | Test system | + +**Table A.3 – Test of conversion gateway, uplink and downlink of platform** + +| Number | Test items | Test methods | Test tools | +|--------|-------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 12 | Tested gateway/platform preset position deletion (uplink) | The test system deletes the preset position of a standard IPC connected to the tested gateway/platform to check whether preset position deletion of the tested gateway/platform is successful. | Test system | +| 13 | Tested gateway/platform guard control (uplink) | The test system sets/cancels the guard position of a standard IPC connected to the tested gateway/platform to check whether the guard control of the tested gateway/platform is effective. | Test system | +| 14 | Tested gateway/platform mandatory key frame (uplink) | The test system sends a mandatory key frame command to a standard IPC connected to the tested gateway/platform to check whether the standard IPC sends the key frame in the video stream immediately. | Test system | +| 15 | Tested gateway/platform video files retrieval (uplink) | The test system retrieves video files of a standard IPC connected to the tested gateway/platform to check whether the retrieval result supplied by the tested gateway/platform supports UDP and TCP transmission; whether there are replies to the message with SumNum equal to 0 when there is no video file. | Test system | +| 16 | Tested gateway/platform video and audio file playback and playback control (uplink) | The test system plays the video recording back of a standard IPC connected to the tested gateway/platform to check whether the playback control including play, pause, fast play, slow play and random drag and drop of the tested gateway/platform is effective; after playback, checks whether the tested gateway/platform sends the flag of playback end; checks whether the tested gateway/platform supports TCP (active and passive connection)/UDP playback mode and whether the media parameters comply with the specification. | Test system | +| 17 | Tested gateway/platform starts manual recording (uplink) | The test system sends a manual recording control command to the standard IPC connected to the tested gateway/platform to check whether the signalling process and content are correct, and whether the tested gateway/platform starts the manual recording successfully. | Test system | +| 18 | Tested gateway/platform stops manual recording (uplink) | The test system sends a command to stop manual recording to a standard IPC connected to the tested gateway/platform to check whether the signalling process and content are correct, and whether the tested gateway/platform stops the manual recording successfully. | Test system | +| 19 | Tested gateway/platform guard (uplink) | The test system sends the guard control command to the standard IPC connected to the tested gateway/platform to check whether the signalling process and content are correct, and whether the guard of the tested gateway/platform is successful. | Test system | + +**Table A.3 – Test of conversion gateway, uplink and downlink of platform** + +| Number | Test items | Test methods | Test tools | +|--------|------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 20 | Tested gateway/platform unguard (uplink) | The test system sends the unguard control command to a standard IPC connected to the tested gateway/platform to check whether the signalling process and content are correct, and whether the tested gateway/platform is successfully unguarded. | Test system | +| 21 | Tested gateway/platform alarm (uplink) | The standard IPC sends alarm messages through the tested gateway/platform to the test system to check whether the signalling process and content are correct. | Test system | +| 22 | Tested gateway/platform alarm reset (uplink) | The test system sends an alarm reset command to a standard IPC connected to the tested gateway/platform to check whether the signalling process and content are correct, and whether the alarm reset of the tested gateway/platform is successful. | Test system | +| 23 | Tested gateway/platform information query (uplink) | The test system sends a device information query command to a standard IPC connected to the tested gateway/platform to check whether the signalling process and content are correct, and whether the device information query result replied by the tested gateway/platform is correct. | Test system | +| 24 | Tested gateway/platform status query (uplink) | The test system sends a device status query command to a standard IPC connected to the tested gateway/platform to check whether the signalling process and content are correct, and whether the device status query result replied by the tested gateway/platform is correct. | Test system | +| 25 | Tested gateway/platform video and audio file download (uplink) | The test system sends a video and audio file download command with parameters such as download speed to a standard IPC connected to the tested gateway/platform to check whether the tested gateway/platform returns the parameters of download speed and file size to the test system and sends the video and audio stream; checks whether the tested gateway/platform sends a download completion notification message to the test system after download is completed; checks whether the tested gateway/platform supports TCP (active and passive connection)/UDP download mode; checks whether media parameters comply with the specification. | Test system | +| 26 | Tested gateway/platform remote booting (uplink) | The test system sends a remote booting command to a standard IPC connected to the tested gateway/platform to check whether the signalling process and content are correct, and whether the standard IPC connected to the tested gateway/platform restarts successfully. | Test system | +| 27 | Tested gateway/platform registered heartbeat status detection (uplink) | Check whether a tested gateway/platform can determine that the test system is offline after registration failure or continuous heartbeat timeout reaches the specified number, and reinitiate registration at an interval. | Test system | + +**Table A.3 – Test of conversion gateway, uplink and downlink of platform** + +| Number | Test items | Test methods | Test tools | +|--------|------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 28 | Tested gateway/platform media stream keepalive mechanism (uplink) | After a tested gateway/platform detects that the test system is offline, check whether the tested gateway/platform stops sending media stream to the test system. | Test system | +| 29 | Tested gateway/platform configuration acquisition (uplink) | The test system sends a device basic parameter configuration acquisition command to the standard IPC connected to the tested gateway/platform to check whether the signalling process and content are correct, and whether the configuration acquisition of the standard IPC connected to the tested gateway/platform is successful. | Test system | +| 30 | Tested gateway/platform configuration (uplink) | The test system sends a device basic parameter configuration command to the standard IPC connected to the tested gateway/platform to check whether the signalling process and content are correct, and whether the parameter configuration of a standard IPC connected to the tested gateway/platform is successful. | Test system | +| 31 | Tested gateway/platform event subscription/unsubscription (uplink) | The test system sends an event subscription/unsubscription command to a standard IPC connected to the tested gateway/platform to check whether the signalling process and content are correct, and whether the event subscription of the tested gateway/platform is successful. | Test system | +| 32 | Tested gateway/platform event notification (uplink) | After the test system sends an event subscription to a standard IPC connected to the tested gateway/platform successfully, the tested gateway/platform sends an event notification to the test system to check whether the signalling process and content are correct, and whether the event notification of the tested gateway/platform is correct. | Test system | +| 33 | Tested gateway/platform audio broadcast and audio intercom (uplink) | The test system dispatches a standard IPC connected to the tested gateway/platform to establish a voice broadcast channel to check whether the signalling process and content are correct, whether the voice stream sent to the standard IPC is effective, and whether the voice intercom is realized, combined with real-time video on demand of the tested gateway/platform. | Test system | +| 34 | Tested gateway/platform directory subscription/unsubscription (uplink) | The test system sends a directory subscription/unsubscription command to the tested gateway/platform to check whether the signalling process and content are correct, and whether the directory subscription/unsubscription is successful. | Test system | + +**Table A.3 – Test of conversion gateway, uplink and downlink of platform** + +| Number | Test items | Test methods | Test tools | +|--------|----------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 35 | Tested gateway/platform directory subscription notification (uplink) | Check whether the tested gateway/platform reports offline status device information after the initial subscription; check whether the signalling process and content are correct, whether the tested gateway/platform notifies to the test system by subscription notification mode after the status and directory changes. | Test system | +| 36 | Tested gateway/platform image snapshot (uplink) | The test system sends an instant image snapshot command to the standard IPC connected to the tested gateway/platform, and the tested gateway/platform sends the snapshot path to the test system to check whether the signalling process and content are correct, and whether the image is uploaded correctly. | Test system | +| 37 | Tested gateway/platform registration (downlink) | Register the test system on the tested gateway/platform, and refreshes registration before registration expiry to check whether the signalling process and content are correct, and whether the registration is successful. | Test system | +| 38 | Tested gateway/platform de-registration (downlink) | De-register the test system from the tested gateway/platform to check whether the signalling process and content are correct and whether the de-registration is successful. | Test system | +| 39 | Tested gateway/platform time calibration (downlink) | The test system obtains the time from the tested gateway/platform to check whether the time calibration is successful. | Test system | +| 40 | Tested gateway/platform heartbeat (downlink) | Check whether the test system sends a heartbeat message to the tested gateway/platform according to the set time interval, and whether the signalling process and content are correct. | Test system | +| 41 | Tested gateway/platform directory query (downlink) | The tested gateway/platform queries the directory of the test system to check whether the signalling process and content are correct, and whether the directory query result of the tested gateway/platform is correct. | Test system | +| 42 | Tested gateway/platform real-time media stream (downlink) | Check whether the tested gateway/platform can play the video and audio stream from the test system in real time; whether the tested gateway/platform supports TCP (active and passive connection)/UDP media stream mode | Test system | +| 43 | Tested gateway/platform remote control (downlink) | The tested gateway/platform sends up, down, left, right, zoom in, zoom out, pull frame zoom in, pull frame zoom out operations to an IPC connected to the test system, check whether the signalling process and content are correct. | Test system | +| 44 | Tested gateway/platform remote control cancel (downlink) | The tested gateway/platform sends a remote control cancellation command to the IPC connected to test system, check whether the signalling process and content are correct. | Test system | + +**Table A.3 – Test of conversion gateway, uplink and downlink of platform** + +| Number | Test items | Test methods | Test tools | +|--------|---------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 45 | Tested gateway/platform preset position setting (downlink) | The tested gateway/platform sets the preset position of an IPC connected to the test system to check whether the signalling process and content are correct. | Test system | +| 46 | Tested gateway/platform position query (downlink) | The tested gateway/platform queries the preset position of an IPC connected to the test system to check whether the signalling process and content are correct. | Test system | +| 47 | Tested gateway/platform preset position call (downlink) | The tested gateway/platform calls the preset position of an IPC connected to the test system to check whether the signalling process and content are correct. | Test system | +| 48 | Tested gateway/platform preset position deletion (downlink) | The tested gateway/platform deletes the preset position of an IPC connected to the test system to check whether the signalling process and content are correct. | Test system | +| 49 | Tested gateway/platform guard control (downlink) | The tested gateway/platform sets/cancels the guard position of an IPC connected to the test system to check whether the signalling process and content are correct. | Test system | +| 50 | Tested gateway/platform mandatory key frame (downlink) | The tested gateway/platform sends a mandatory key frame command to an IPC connected to the test system to check whether the signalling process and content are correct. | Test system | +| 51 | Tested gateway/platform video files retrieval (downlink) | The tested gateway/platform retrieves video files from the test system to check whether the test gateway/platform supports receiving the video file information through UDP, TCP. | Test system | +| 52 | Tested gateway/platform video and audio file playback and playback control (downlink) | The tested gateway/platform plays the video recording back of the test system, and performs playback control of play, pause, fast play, slow play and random drag-and-drop; when the playback is over, the test system sends a playback completion notification message to check whether the tested gateway/platform disconnects the playback channel; checks whether the tested gateway/platform supports TCP (active and passive connection mode)/UDP playback mode. | Test system | +| 53 | Tested gateway/platform starts manual recording (downlink) | The tested gateway/platform sends a manual recording control command to an IPC connected to the test system, check whether the signalling process and content are correct. | Test system | +| 54 | Tested gateway/platform stops manual recording (downlink) | The tested gateway/platform sends a command to stop manual recording to the IPC connected to the test system, check whether the signalling process and content are correct. | Test system | + +**Table A.3 – Test of conversion gateway, uplink and downlink of platform** + +| Number | Test items | Test methods | Test tools | +|--------|--------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 55 | Tested gateway/platform guard (downlink) | The tested gateway/platform sends a guard command to the test system, check whether the signalling process and content are correct. | Test system | +| 56 | Tested gateway/platform unguard (downlink) | The tested gateway/platform sends an unguard command to the test system, check whether the signalling process and content are correct. | Test system | +| 57 | Tested gateway/platform alarm (downlink) | The IPC sends alarm messages through the test system to the tested gateway/platform to check whether the tested gateway/platform receives the messages and displays them. | Test system | +| 58 | Tested gateway/platform alarm reset (downlink) | The tested gateway/platform sends an arm reset command to the test system, check whether the signalling process and content are correct. | Test system | +| 59 | Tested gateway/platform information query (downlink) | The tested gateway/platform sends an information query command to the test system, check whether the signalling process and content are correct. | Test system | +| 60 | Tested gateway/platform status query (downlink) | The tested gateway/platform sends a status query command of to the test system, check whether the signalling process and content are correct. | Test system | +| 61 | Tested gateway/platform video and audio file download (downlink) | The tested gateway/platform sends a video and audio file download command to the test system, the test system sends the video and audio stream after receiving the command message, when the download is over, the test system sends a download completion notification message to the tested gateway/platform, checks whether the tested gateway/platform disconnects the download link; checks whether the tested gateway/platform supports the TCP (active and passive connection)/UDP download mode. | Test system | +| 62 | Tested gateway/platform remote booting (downlink) | The tested gateway/platform sends a remote booting command to the test system, check whether the signalling process and content are correct. | Test system | +| 63 | Tested gateway/platform registered heartbeat status detection (downlink) | Check whether the tested gateway/platform can determine that the test system is offline after the registration failure or continuous heartbeat timeout reaches the specified number. | Test system | +| 64 | Tested gateway/platform media stream keepalive mechanism (downlink) | After the tested gateway/platform detects that the test system is offline, check whether the tested gateway/platform disconnects the media stream link. | Test system | + +**Table A.3 – Test of conversion gateway, uplink and downlink of platform** + +| Number | Test items | Test methods | Test tools | +|--------|---------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------| +| 65 | Tested gateway/platform configuration acquisition (downlink) | The tested gateway/platform sends a device basic parameter configuration acquisition command to an IPC connected to the test system, check whether the signalling process and content are correct. | Test system | +| 66 | Tested gateway/platform configuration (downlink) | The tested gateway/platform sends a device basic parameter configuration command to an IPC connected to the test system, check whether the signalling process and content are correct. | Test system | +| 67 | Tested gateway/platform event subscription/ unsubscription (downlink) | The tested gateway/platform sends an event subscription/unsubscription command to the IPC connected to the test system, check whether the signalling process and content are correct. | Test system | +| 68 | Tested gateway/platform event notification (downlink) | After the tested gateway/platform sends an event subscription to an IPC connected to the test system successfully, the test system sends an event notification to the tested gateway/platform to check whether the signalling process and content are correct. | Test system | +| 69 | Tested gateway/platform audio broadcast and audio intercom (downlink) | The tested gateway/platform dispatches an IPC connected to the test system to establish a voice broadcast channel to check whether the signalling process and content are correct, check whether the voice intercom is realized, combined with the real-time media stream of the tested gateway/platform. | Test system | +| 70 | Tested gateway/platform directory subscription/ unsubscription (downlink) | The tested gateway/platform sends a directory subscription/unsubscription command to the IPC connected to the test system, check whether the signalling process and content are correct. | Test system | +| 71 | Tested gateway/platform directory subscription notification (downlink) | The test system reports offline status device information after initial subscription, check whether the signalling process and content are correct; the test system sends the status change, directory change message, check whether the signalling process and content are correct, whether the tested gateway/platform updates the directory. | Test system | +| 72 | Tested gateway/platform image snapshot (downlink) | The tested gateway/platform sends an instant image snapshot command to an IPC connected to the test system, and the test system sends the snapshot path to the tested gateway/platform, check whether the signalling process and content are correct and whether the image is uploaded correctly. | Test system | + +**Table A.4 – Standard device access test** + +| Number | Testing items | Testing methods | Test tools | +|--------|----------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------| +| 1 | NVR device registration | Register the standard NVR on the tested platform and refresh registration before registration expiry to check whether the signalling process and content are correct, and whether the registration is successful. | test system, standard NVR, standard IPC | +| 2 | NVR device de-registration | De-register the standard NVR from the tested platform, and check whether the signalling process and content are correct and whether the de-registration is successful. | test system, standard NVR, standard IPC | +| 3 | NVR device time calibration | The standard NVR obtains the time from the tested platform to check whether the time calibration is successful. | test system, standard NVR, standard IPC | +| 4 | NVR device heartbeat | Check whether the standard NVR sends a heartbeat messages to the registered tested platform according to the set time interval, and whether the signalling process and content are correct. | test system, standard NVR, standard IPC | +| 5 | NVR device directory query | The tested platform queries the directory and equipment information of the standard NVR to check whether the signalling process and content are correct, and whether the query result of the standard NVR directory is correct. | test system, standard NVR, standard IPC | +| 6 | NVR real time media stream | The tested platform plays the video and audio stream transmitted by the standard NVR in real time, and checks whether the platform under test supports TCP (active and passive connection mode)/UDP media stream mode. | test system, standard NVR, standard IPC | +| 7 | NVR device remote control | The tested platform remotely controls the acquisition device connected to the standard NVR, performs the operations of up, down, left, right, zoom in, zoom out, pull frame zoom out, etc., and checks whether the signalling process and content are correct, and whether the remote control of the standard NVR device is effective. | test system, standard NVR, standard IPC | +| 8 | NVR device remote control cancellation | The tested platform cancels the remote control of the acquisition device connected to the standard NVR, and checks whether the signalling process and content are correct, and whether the cancellation of the remote control of the standard NVR equipment is effective. | test system, standard NVR, standard IPC | +| 9 | NVR preset setting | The tested platform sets the preset position of the acquisition device connected to the standard NVR to check whether the signalling process and content are correct, and whether the preset bit setting of the standard NVR equipment is effective. | test system, standard NVR, standard IPC | +| 10 | NVR preset position query | The tested platform queries the preset position of the acquisition device connected to the standard NVR to check whether the signalling process and content are correct, and whether the query result of the preset position of the standard NVR device is correct. | test system, standard NVR, standard IPC | + +**Table A.4 – Standard device access test** + +| Number | Testing items | Testing methods | Test tools | +|--------|------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------| +| 11 | NVR preset position calling | The tested platform calls the preset position of the acquisition device connected to the standard NVR to check whether the signalling process and content are correct, and whether the call of the preset position of the standard NVR device is effective. | test system, standard NVR, standard IPC | +| 12 | NVR preset position deletion | The tested platform deletes the preset position of the acquisition device connected to the standard NVR, checks whether the signalling process and content are correct, and whether the deletion of the preset position of the standard NVR device is effective. | test system, standard NVR, standard IPC | +| 13 | NVR guard control | The tested platform sets/cancels the guard position of the acquisition device connected to the standard NVR, and checks whether the signalling process and content are correct, and whether the guard bit control of the standard NVR device is effective. | test system, standard NVR, standard IPC | +| 14 | NVR mandatory key frame | The tested platform sends the mandatory key frame command to the standard NVR to check whether the standard NVR sends the key frame in the video and audio stream immediately. | test system, standard NVR, standard IPC | +| 15 | NVR device video file retrieval | The tested platform retrieves the video files in the standard NVR to check whether the tested platform supports receiving video file information through UDP and TCP. | test system, standard NVR, standard IPC | +| 16 | Video and audio file playback and playback control of NVR device | The tested platform plays video and audio files back in the standard NVR, and performs the playback control to check whether the playback control of standard NVR play, pause, fast play, slow play and random drag and drop is effective; at the end of playback, the standard NVR sends a playback completion notification message to check whether the tested platform has disconnected the playback link; and whether the tested platform supports TCP (active and passive connection mode)/UDP playback mode. | test system, standard NVR, standard IPC | +| 17 | NVR device starts manual recording | The tested platform sends a manual recording control command to the standard NVR to check whether the signalling process and content are correct, and whether the standard NVR starts the manual recording successfully. | test system, standard NVR, standard IPC | +| 18 | NVR device stops manual recording | The tested platform sends a command to stop manual recording to a standard NVR device to check whether the signalling process and content are correct, and whether the standard NVR stops the manual recording successfully. | test system, standard NVR, standard IPC | +| 19 | NVR device guard | The tested platform sends a guard command to the standard NVR to check whether the signalling process and content are correct and whether the guard of the standard NVR is successful. | test system, standard NVR, standard IPC | + +**Table A.4 – Standard device access test** + +| Number | Testing items | Testing methods | Test tools | +|--------|------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------| +| 20 | NVR device unguard | The tested platform sends an unguard command to the standard NVR to check whether the signalling process and content are correct and whether the unguard of the standard NVR has successfully proceeded. | test system, standard NVR, standard IPC | +| 21 | NVR device alarm | The standard NVR sends device alarm messages to the tested platform with guard to check whether the signalling process and content are correct. | test system, standard NVR, standard IPC | +| 22 | NVR device alarm reset | The tested platform sends an alarm reset command to the standard NVR to check whether the signalling process and content are correct and whether the standard NVR alarm reset is successful. | test system, standard NVR, standard IPC | +| 23 | NVR device information query | The tested platform sends a device information query command to the standard NVR to check whether the signalling process and content are correct, and whether the standard NVR information query result is correct. | test system, standard NVR, standard IPC | +| 24 | NVR device status query | The tested platform sends a device status query command to the standard NVR to check whether the signalling process and content are correct, and whether the standard NVR status query result is correct. | test system, standard NVR, standard IPC | +| 25 | NVR device video and audio file download | The tested platform sends an video and audio file download command with download speed and other parameters to the standard NVR device, checks whether the standard NVR receives the message, whether the parameters such as download speed and file size are sent back to the tested platform, and sends the video and audio stream; checks whether the platform under test supports TCP (active and passive connection mode)/UDP download mode; after the download, the standard NVR sends the download completion notice message to check whether the tested platform is disconnected from the download link. | test system, standard NVR, standard IPC | +| 26 | NVR device remote start | The tested platform sends a remote boot command to the standard NVR to check whether the signalling process and content are correct and whether the standard NVR restart is successful. | test system, standard NVR, standard IPC | +| 27 | NVR device configuration query | The tested platform sends a device configuration query command to the standard NVR to check whether the signalling process and content are correct and whether the query of the basic parameter configuration of the standard NVR is successful. | test system, standard NVR, standard IPC | +| 28 | NVR device configuration | The tested platform sends the basic parameter configuration command to the standard NVR to check whether signalling process and content are correct and whether the basic parameter configuration of the standard NVR is successful. | test system, standard NVR, standard IPC | + +**Table A.4 – Standard device access test** + +| Number | Testing items | Testing methods | Test tools | +|--------|---------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------| +| 29 | NVR event subscription/unsubscription | The tested platform sends an event subscription/unsubscription command to the standard NVR to check whether the signalling process and content are correct, and whether the standard NVR event subscription/unsubscription is successful. | test system, standard NVR, standard IPC | +| 30 | NVR event notification | The standard NVR sends an event notification to the tested platform to check whether the signalling process and content are correct, and whether the event notification received by the tested platform is correct. | test system, standard NVR, standard IPC | +| 31 | NVR image snapshot | The tested platform sends a standard IPC image snapshot command to the standard NVR, checks whether the signalling process and content are correct, whether the image uploading is correct. | test system, standard NVR, standard IPC | +| 32 | IPC device registration | Register the standard IPC on the tested platform, and refresh registration before registration expiry to check whether the signalling process and content are correct, and whether the registration is successful. | test system, standard IPC | +| 33 | IPC device de-registration | De-register a standard IPC from the tested platform, and check whether the signalling process and content are correct and whether the de-registration is successful. | test system, standard IPC | +| 34 | IPC device time calibration | The standard IPC obtains the time from the tested platform to check whether the time calibration is successful. | test system, standard IPC | +| 35 | IPC device heartbeat | Check whether a standard IPC sends heartbeat messages to the registered tested platform according to the set time interval, and whether the signalling process and content are correct. | test system, standard IPC | +| 36 | IPC device directory query | The tested platform queries the directory and device information of a standard IPC to check whether the signalling process and content are correct, and whether the query result of the standard IPC directory is correct. | test system, standard IPC | +| 37 | IPC device real-time media stream | The tested platform plays the video and audio stream transmitted by a standard IPC in real time to check whether the platform supports TCP (active and passive connection mode)/UDP media stream mode. | test system, standard IPC | +| 38 | Remote control of IPC device | The tested platform remotely controls a standard IPC, performs the operations of up, down, left, right, zoom in, zoom out, pull frame zoom in, etc., checks whether the signalling process and content are correct, and whether the remote control of the standard IPC device is effective. | test system, standard IPC | + +**Table A.4 – Standard device access test** + +| Number | Testing items | Testing methods | Test tools | +|--------|------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------| +| 39 | Remote control cancel of IPC device | The tested platform cancels the remote control of a standard IPC, and checks whether the signalling process and content are correct, and whether the cancellation of remote control of the standard IPC device is effective. | test system, standard IPC | +| 40 | IPC preset position setting | The tested platform sets the preset position of a standard IPC, to check whether the signalling process and content are correct, and whether the preset position setting of the standard IPC device is effective. | test system, standard IPC | +| 41 | IPC preset position query | The tested platform queries the preset position of a standard IPC, and checks whether the signalling process and content are correct, and whether the query results of the preset position of the standard IPC device are correct. | test system, standard IPC | +| 42 | IPC preset position call | The tested platform calls the preset position of a standard IPC to check whether the signalling process and content are correct, and whether the call of the standard IPC device preset position is effective. | test system, standard IPC | +| 43 | IPC preset position deletion | The platform under test deletes the preset position of a standard IPC, checks whether the signalling process and content are correct, and whether the deletion of preset position of the standard IPC device is effective. | test system, standard IPC | +| 44 | IPC guard control | The tested platform sets/cancels the guard position of a standard IPC, checks whether the signalling process and content are correct, and whether the guard position control of the standard IPC device is effective. | test system, standard IPC | +| 45 | IPC mandatory key frame | The tested platform sends a mandatory key frame command to a standard IPC, and checks whether the tested platform sends the key frame in the video stream to the IPC device immediately. | test system, standard IPC | +| 46 | IPC device video file retrieval | The tested platform retrieves the video files in a standard IPC to check whether the tested platform supports receiving video file information through UDP and TCP. | test system, standard IPC | +| 47 | Video and audio file playback and playback control of IPC device | The tested platform plays video and audio files back in the standard IPC, and performs playback control to check whether the playback control of the standard IPC play, pause, fast play, slow play and random drag and drop is effective; at the end of playback, the standard IPC sends a playback completion notification message to check whether the tested platform has disconnected the playback link, and whether the tested platform supports TCP (active and passive connection mode)/UDP playback mode. | test system, standard IPC | + +**Table A.4 – Standard device access test** + +| Number | Testing items | Testing methods | Test tools | +|--------|------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------| +| 48 | IPC device starts manual recording | The tested platform sends a manual recording control command to a standard IPC to check whether the signalling process and content are correct, and whether the standard IPC starts the manual recording successfully. | test system, standard IPC | +| 49 | IPC device stops manual recording | The tested platform sends a command to stop manual recording to the standard IPC to check whether the signalling process and content are correct, and whether the standard IPC stops the manual recording successfully. | test system, standard IPC | +| 50 | IPC device guard | The tested platform sends a guard command to a standard IPC to check whether the signalling process and content are correct, and whether the standard IPC guard is successful. | test system, standard IPC | +| 51 | IPC device unguard | The tested platform sends an unguard command to the standard IPC to check whether the signalling process and content are correct, and whether the standard IPC unguard is successful. | test system, standard IPC | +| 52 | IPC device alarm | The standard IPC sends device alarm messages to the tested platform to check whether the signalling process and content are correct. | test system, standard IPC | +| 53 | IPC device alarm reset | The tested platform sends a device alarm reset command to the standard IPC to check whether signalling process and content are correct, and whether the device alarm reset of the standard IPC is successful. | test system, standard IPC | +| 54 | IPC device information query | The tested platform sends a device information query command to a standard IPC to check whether the signalling process and content are correct, and whether the query result of the standard IPC information is correct. | test system, standard IPC | +| 55 | IPC device status query | The tested platform sends a device status query command to a standard IPC to check whether the signalling process and content are correct, and whether the query result of the standard IPC status is correct. | test system, standard IPC | + +**Table A.4 – Standard device access test** + +| Number | Testing items | Testing methods | Test tools | +|--------|------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------| +| 56 | IPC device audio and video file download | The tested platform sends a video and audio file download command with parameters such as download speed to a standard IPC device, checks whether the standard IPC receives the message, whether the parameters such as download speed and file size are sent back to the tested platform, and sends video and audio stream; checks whether the tested platform supports TCP (active and passive connection mode)/UDP download mode; when the download ends, the standard IPC sends a download completion notice message to check whether the tested platform is disconnected from the download link. | test system, standard IPC | +| 57 | IPC device remote start | The tested platform sends a remote start command to a standard IPC device to check whether the signalling process and content are correct, and whether the standard IPC is restarted successfully. | test system, standard IPC | +| 58 | IPC device configuration acquisition | The tested platform sends a device configuration acquisition command to the standard IPC to check whether the signalling process and content are correct, and whether the acquisition of basic parameter configuration of the standard IPC is successful. | test system, standard IPC | +| 59 | IPC device configuration | The tested platform sends a basic parameter configuration command to a standard IPC to check whether the signalling process and content are correct, and whether the basic parameter configuration of the standard IPC is successful. | test system, standard IPC | +| 60 | IPC event subscription/unsubscription | The tested platform sends an event subscription/unsubscription command to a standard IPC to check whether the signalling process and content are correct, and whether the standard IPC event subscription/unsubscription is successful. | test system, standard IPC | +| 61 | IPC event notification | A standard IPC sends event notification messages to the tested platform to check whether the signalling process and content are correct, and whether the event notification received by the tested platform is correct. | test system, standard IPC | +| 62 | IPC image snapshot | The tested platform sends the image snapshot command to the standard IPC to check whether the signalling process and content are correct, and whether the image uploading is correct. | test system, standard IPC | +| 63 | Decoding device registration | Register the standard decoding device on the tested platform, and refresh registration before registration expiry to check whether the signalling process and content are correct, and whether the registration is successful. | test system, standard decoder | + +**Table A.4 – Standard device access test** + +| Number | Testing items | Testing methods | Test tools | +|--------|-------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------| +| 64 | Decoding device de-registration | De-register a standard decoding device from the tested platform, and check whether the signalling process and content are correct, and whether the de-registration is successful. | test system, standard decoder | +| 65 | Decoding device time calibration | A standard decoding device obtains the time from the tested platform and checks whether the time calibration is successful. | test system, standard decoder | +| 66 | Decoding device heartbeat | Check whether a standard decoding device sends a heartbeat message to the registered tested platform according to the set time interval, and whether the signalling process and content are correct. | test system, standard decoder | +| 67 | Decoding device directory query | The tested platform queries the standard decoding device directory and device information to check whether the signalling process and content are correct, and whether the query result of the standard decoding device directory is correct. | test system, standard decoder | +| 68 | Decoding device real-time media stream | Check whether a standard decoding device can play the video and audio stream sent by the tested platform in real time, and whether the tested platform supports TCP (active and passive connection mode)/UDP media stream mode. | test system, standard decoder | +| 69 | Decoding device information query | The tested platform sends a device information query command to a standard decoding device to check whether the signalling process and content are correct, and whether the standard decoding device information query result is correct. | test system, standard decoder | +| 70 | Decoding device status query | The tested platform sends a device status query command to a standard decoding device to check whether the signalling process and content are correct, and whether the standard decoding device status query result is correct. | test system, standard decoder | +| 71 | Decoding device remote start | The tested platform sends a remote start command to a standard decoding device to check whether the signalling process and content are correct, and whether the standard decoding device is restarted successfully. | test system, standard decoder | +| 72 | Decoding device configuration acquisition | The tested platform sends a device configuration acquisition command to a standard decoding device to check whether the signalling process and content are correct, and whether the acquisition of the basic parameter configuration of the standard decoding device is successful. | test system, standard decoder | +| 73 | Decoding device configuration | The tested platform sends a device configuration command to a standard decoding device to check whether the signalling process and content are correct, and whether the basic parameter configuration of the standard decoding device is successful. | test system, standard decoder | + + + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| <b>Series T</b> | <b>Terminals for telematic services</b> | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.70-199303-I_PDF-E/raw.md b/marked/T/T-REC-T.70-199303-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..7519f383d3d92db20150c9f9633f4ca464a2c74e --- /dev/null +++ b/marked/T/T-REC-T.70-199303-I_PDF-E/raw.md @@ -0,0 +1,2880 @@ + + +![ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol below it.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, and a lightning bolt symbol below it. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## T.70 + +(03/93) + +**TELEMATIC SERVICES** + +**TERMINAL EQUIPMENTS AND PROTOCOLS +FOR TELEMATIC SERVICES** + +--- + +**NETWORK-INDEPENDENT +BASIC TRANSPORT SERVICE +FOR THE TELEMATIC SERVICES** + +**ITU-T Recommendation T.70** + +(Previously "CCITT Recommendation") + +--- + +# FOREWORD + +The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the International Telecommunication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +ITU-T Recommendation T.70 was revised by the ITU-T Study Group VIII (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). + +# --- NOTES + +1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCITT ceased to exist as of 28 February 1993. In its place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector. + +In order not to delay publication of this Recommendation, no change has been made in the text to references containing the acronyms “CCITT, CCIR or IFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new ITU structure. + +2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +# CONTENTS + +| | | <i>Page</i> | +|-----------|-----------------------------------------------------------------------------------------------------------------------|-------------| +| 1 | Scope..... | 1 | +| 2 | Transport service..... | 1 | +| | 2.1 Transport service objectives ..... | 1 | +| | 2.2 General structure of the transport service ..... | 2 | +| 3 | Transport service implementation for different types of networks ..... | 3 | +| | 3.1 Terminals connected to a PSPDN..... | 3 | +| | 3.2 Terminals connected to the PSTN ..... | 3 | +| | 3.3 Terminals connected to a CSPDN ..... | 4 | +| | 3.4 Terminals connected to an ISDN..... | 8 | +| 4 | Interworking between networks ..... | 8 | +| 5 | Transport layer procedure ..... | 9 | +| | 5.1 Transport functions..... | 9 | +| | 5.2 Description of connection establishment and termination procedures ..... | 10 | +| | 5.3 Description of data transfer procedures ..... | 12 | +| | 5.4 Treatment of procedure errors ..... | 13 | +| | 5.5 Formats ..... | 13 | +| Annex A | ..... | 22 | +| | A.1 Transport and network service..... | 22 | +| | A.2 State transition diagrams for the basic transport layer procedures ..... | 27 | +| Annex B | ..... | 30 | +| | B.1 State tables..... | 30 | +| | B.2 Lists of events, actions and conditions ..... | 30 | +| Annex C – | Recommendations for implementation of Recommendation X.21 ..... | 40 | +| | C.1 General..... | 40 | +| | C.2 Receipt of call progress signals 01 or 04 ..... | 40 | +| | C.3 Receipt of call progress signal 03 ..... | 40 | +| | C.4 Receipt of call progress signals of the group 2 to 8 ..... | 41 | +| Annex D – | Service definitions and state transition diagrams for the HDLC procedure and the network layer defined for CSPDN..... | 41 | +| | D.1 Service definitions ..... | 41 | +| | D.2 State transition diagrams HDLC..... | 46 | +| | D.3 Summary of frame definitions ..... | 53 | +| | D.4 X.21 service, controlled by the network layer ..... | 53 | + + + +# NETWORK-INDEPENDENT BASIC TRANSPORT SERVICE FOR THE TELEMATIC SERVICES + +(Geneva, 1980, amended at Malaga-Torremolinos, 1984; +Melbourne, 1988 and Helsinki, 1993) + +The CCITT, + +*considering* + +- (a) that the Teletex service will be introduced in different types of network, i.e. circuit-switched public data networks (CSPDN), packet-switched public data networks (PSPDN) and the public switched telephone network (PSTN); +- (b) that there is a need for international interworking between terminals belonging to the same or different types of Telematic services; + +*unanimously declares the following view* + +# 1 Scope + +**1.1** This Recommendation defines the *network-independent basic transport service* applicable to Teletex and Group 4 facsimile terminals connected to the types of network mentioned in (a) above in terms of: + +- a) the transport services provided to the higher layer [the transport services are provided by the transport layer (layer 4) in association with the underlying services provided by the supporting layers 1 to 3]; +- b) the transport layer procedure (see clause 5 below). + +**1.2** Clause 2 describes the transport service. Clause 3 describes the transport service implementation for different types of networks. Clause 4 outlines the guidelines for interworking between networks. Clause 5 specifies the transport layer procedure, and Annexes A and B provide associated state transition diagrams and tables, respectively. + +# 2 Transport service + +## 2.1 Transport service objectives + +**2.1.1** The purpose of the transport service is to provide two communicating session entities within two terminals with transport services, i.e. the means for transparent and reliable end-to-end transfer of data between them irrespective of the particular type of network used. + +**2.1.2** The main requirements of the transport service to be provided by a transport entity to the local transport user, i.e. the session entity, are: + +- a) *Network independence* – The transport service shall be homogeneous, while allowing a suitable wide variety of underlying communications media, protocols and mechanisms. +- b) *End-to-end significance* – The transport service shall have end-to-end significance, connecting the end users irrespective of the number of individual communication links used. +- c) *Transparency* – The transport service shall be octet transparent, i.e. not restrict the content, format or coding of the information (data or control) received from or delivered to the transport user. +- d) *Error-free delivery* – The transport service shall assure error-free delivery. Non-recoverable errors are to be visible to the transport service user. +- e) *Cost efficiency* – The transport service shall optimize the use of the available communication resources to provide the performance required by each communicating transport user at maximum efficiency. + +## 2.2 General structure of the transport service + +### 2.2.1 The general structure of the transport service is shown in Figure 1. + +![Figure 1: Transport service general structure. A hierarchical diagram showing four layers: Transport layer (layer 4), Network layer (layer 3), Link layer (layer 2), and Physical layer (layer 1). The Transport layer connects to a 'To and from transport user (session layer)'. The Network layer is divided into 'Call control phase' and 'Data transfer phase'. The Link layer is also divided into 'Call control phase' and 'Data transfer phase'. The Physical layer is divided into 'PSPDN', 'CSPDN', 'PSTN', and 'ISDN'. The diagram shows the flow of data and control signals between these layers and networks.](a7d78d22e465dea388b31d0739f9d0cd_img.jpg) + +The diagram illustrates the general structure of the transport service across four layers: + +- Transport layer (layer 4):** Contains the 'Transport layer procedure (Clause 5) (Note 6)'. It connects to the 'To and from transport user (session layer)'. +- Network layer (layer 3):** Divided into 'Call control phase' and 'Data transfer phase'. + - Call control phase:** Includes 'X.25 call procedure', 'X.21 call procedure', 'Telephone + X.25 call procedure (Notes 2, 3, 9)', and 'Rec. T.90'. + - Data transfer phase:** Includes 'X.25 data transfer', 'Null (Note 7)', 'X.25 data transfer (Note 1)', and 'Rec. T.90'. +- Link layer (layer 2):** Divided into 'Call control phase' and 'Data transfer phase'. + - Call control phase:** Includes 'LAPB/X.25', '2 syn. characters (X.21)', and 'X.75 (Note 5)'. + - Data transfer phase:** Includes 'X.75 or T.71 (Notes 4, 5)' and 'Rec. T.90'. +- Physical layer (layer 1):** Divided into 'PSPDN', 'CSPDN', 'PSTN', and 'ISDN'. + - PSPDN:** Includes 'X.21 or X.21 bis'. + - CSPDN:** Includes 'X.21, X.21 bis or X.22'. + - PSTN:** Includes 'e.g. V.24 (Notes 8, 9)'. + - ISDN:** Includes 'Rec. T.90'. + +References: T0817560-94/d01 + +Figure 1: Transport service general structure. A hierarchical diagram showing four layers: Transport layer (layer 4), Network layer (layer 3), Link layer (layer 2), and Physical layer (layer 1). The Transport layer connects to a 'To and from transport user (session layer)'. The Network layer is divided into 'Call control phase' and 'Data transfer phase'. The Link layer is also divided into 'Call control phase' and 'Data transfer phase'. The Physical layer is divided into 'PSPDN', 'CSPDN', 'PSTN', and 'ISDN'. The diagram shows the flow of data and control signals between these layers and networks. + +#### NOTES + +- 1 The X.25 network layer procedure is introduced to ease interworking with PSPDNs. +- 2 The establishing of the network connection is performed by two-stage selection: the first using normal telephone procedures and the second using X.25 call control procedures. +- 3 For terminals connected to PSTN accessing PSPDN, the procedures in Note 2 apply. See also Recommendation X.32. +- 4 Recommendation T.71 defines a half-duplex link access procedure, based on Recommendation X.75 for single link operation (see 3.2.2). +- 5 The link layer procedures are in accordance with Recommendation X.75 for single link operation. Additional application rules can be found in 3.2.2. and 3.3.2. +- 6 In all cases of interworking including interworking between terminals connected to the same type of network or to different types of networks (i.e. CSPDN, PSPDN, PSTN), this transport layer procedure is executed peer-to-peer between the communicating terminals. +- 7 For terminals connected to CSPDNs, no function is needed in the network layer in the data transfer phase as indicated in this figure. However, in order to facilitate interworking with PSPDNs a minimum network layer is introduced (see 3.3.3). +- 8 The modem may also be integrated within the terminal and in such cases Recommendation V.24 need not apply (see 3.2.1). +- 9 For automatic calling and/or answering, Recommendation V.25 may be applicable. + +FIGURE 1/T.70 +Transport service general structure + +# 3 Transport service implementation for different types of networks + +NOTE – The transport layer procedure on all types of networks is defined in clause 5. The network dependent control procedures of the underlying layers are described in the following. + +## 3.1 Terminals connected to a PSPDN + +### 3.1.1 Physical layer DTE/DCE interface characteristics + +The physical layer of Recommendation X.25 applies. + +### 3.1.2 Link layer procedure + +The link layer procedure shall, unless otherwise specified, be the symmetrical procedures as specified in Recommendation X.25, LAPB (Link Access Procedure B). + +### 3.1.3 Network layer procedure + +Recommendation X.25 Virtual Call procedures apply. However, the following points should be noted when using this transport protocol: + +- a) The qualifier bit in data packets should always be set to 0. +- b) The delivery confirmation bits in all packets should be set to 0. +- c) The terminal should not send an *interrupt request* packet. +- d) Normal X.25 reset procedures will apply. +- e) Each control block or data block of the transport layer shall be carried in a complete data packet sequence. +- f) The terminal should not send a *DTE REJ packet*. +- g) Terminals shall use a specific protocol identifier within call request/incoming call packets for the Teletex service and Group 4 facsimile apparatus. This identifier is represented by the first octet of the call user data field (remaining octets, if any, should be ignored) as shown below: + +bit            87654321 + +octet 1       00000010 + +In the case of CSPDN/PSPDN interworking the functional mapping of this protocol identifier requires further study. + +- h) Terminals shall not use the fast select facility. + +## 3.2 Terminals connected to the PSTN + +### 3.2.1 Physical layer DTE/DCE interface characteristics + +The DTE/DCE physical layer element shall be in accordance with existing Series V Recommendations. The physical layer may provide for half-duplex or full-duplex transmission depending on the modem standard. + +NOTE – The PSTN modem standards are discussed in Study Group XVII. Furthermore, in the case of a modem integrated in the terminal, the interface may only be functionally equivalent to a Series V Recommendation. This is also for further consideration in Study Group XVII. + +### 3.2.2 Link layer procedure + +**3.2.2.1** Depending on the service provided by the physical layer, the link layer procedures over a single physical circuit between two terminals have to cater for a half-duplex or full-duplex transmission facility to provide a full-duplex service to the network layer. For full-duplex physical layer service, the link layer procedure shall conform to the Link Access Procedure described in Recommendation X.75, for single link operation. For addressing assignments and the system parameters see 3.2.2.2 and 3.2.2.3, respectively. For half-duplex physical layer service the link layer procedure is as defined in Recommendation T.71. This is a half-duplex Link Access Procedure, based on Recommendation X.75 for single link operation. + +**3.2.2.2** The following describes the application of the link addressing procedure of Recommendation X.75. Link addresses (A and B) shall be assigned dynamically or on a per-call basis according to the following rules: + +- a) the calling terminal shall take Address A; +- b) the called terminal shall take Address B; +- c) commands and responses shall be transferred as shown in Figure 2; +- d) A and B addresses are coded as follows: + +| | | +|---------|----------| +| Address | 12345678 | +| A | 11000000 | +| B | 10000000 | + +*NOTE – The terminal will discard all frames received with an address other than A and B.* + +![Diagram showing message flow between Calling terminal A and Called terminal B. Commands (B) and Responses (A) flow from A to B. Responses (B) and Commands (A) flow from B to A.](35a7554182eb055209552843f341a1ae_img.jpg) + +``` + +sequenceDiagram + participant A as Calling terminal A + participant B as Called terminal B + A->>B: Commands (B) + B->>A: Responses (B) + B->>A: Commands (A) + A->>B: Responses (A) + +``` + +T0817570-94/d02 + +Diagram showing message flow between Calling terminal A and Called terminal B. Commands (B) and Responses (A) flow from A to B. Responses (B) and Commands (A) flow from B to A. + +FIGURE 2/T.70 + +**3.2.2.3** System parameters are: + +- a) timer, T1; +- b) maximum number of retransmissions, N2; +- c) maximum number of bits in an I frame, N1; +- d) maximum number of outstanding I frames, $k$ . + +The above system parameters are to be specified by the Administration. However, the possible range of values that may be attributed to each parameter is to be standardized. Such values are for further study. + +### 3.2.3 Network layer procedure + +**3.2.3.1** See 3.1.3. In addition, for all calls (PSTN only, PSTN-PSPDN, PSTN-PSPDN-PSTN) second stage addressing will apply using X.25 virtual call procedures. The calling terminal should include the called address and the calling address (see Note 2) in call request packets. The format of the called address shall conform to: + +- a) the telephone network addressing scheme for PSTN only calls; +- b) the telephone network addressing scheme with an X.121 DNIC for PSTN-PSPDN calls (see Note 3); +- c) the X.121 addressing scheme for PSTN-PSPDN calls (see Note 1). + +#### **NOTES** + +- 1 For other cases of internetworking the above rule shall apply. +- 2 In the case of PSTN-PSPDN calls the verification of the calling address by the network requires further study. The format of the calling address is for further study. +- 3 The feasibility of such connections is for further study. + +## 3.3 Terminals connected to a CSPDN + +### 3.3.1 Physical layer DTE/DCE interface characteristics + +The DTE/DCE physical interface characteristics shall be in accordance with Recommendation X.21, or as an option, Recommendation X.22 for multi-call operation. + +### 3.3.2 Link layer procedure + +#### 3.3.2.1 General + +The link layer procedure shall be used during the data phase of Recommendation X.21 (or X.22) for data interchange over a single physical circuit between two terminals operating in User Classes of Services 3 to 7 and 30 as defined in Recommendation X.1. The link layer procedure shall consist of a fully symmetrical HDLC procedure as defined in Recommendation X.75 for single link operation. + +#### 3.3.2.2 Link layer address procedure + +The following describes the application of the link addressing procedures of Recommendation X.75. Link addresses (A and B) shall be assigned dynamically on a per-call basis according to the following rules: + +- a) the calling terminal shall take address A; +- b) the called terminal shall take address B; +- c) commands and responses shall be transferred as shown in Figure 3; +- d) A and B addresses are coded as follows: + +| | | +|---------|----------| +| Address | 12345678 | +| A | 11000000 | +| B | 10000000 | + +NOTE – The terminal will discard all frames received with an address other than A and B. + +![Diagram showing the link layer address procedure between a Calling terminal A and a Called terminal B. The diagram illustrates the flow of commands and responses for both terminals. Calling terminal A sends Commands (B) to Called terminal B and receives Responses (B) back. Similarly, Called terminal B sends Commands (A) to Calling terminal A and receives Responses (A) back. The diagram is labeled T0817580-94/d03.](a234352dfaccdc24745c88eef7724cc6_img.jpg) + +``` +graph LR; A[Calling terminal A] -- "Commands (B)" --> B[Called terminal B]; B -- "Responses (B)" --> A; B -- "Commands (A)" --> A; A -- "Responses (A)" --> B; +``` + +T0817580-94/d03 + +Diagram showing the link layer address procedure between a Calling terminal A and a Called terminal B. The diagram illustrates the flow of commands and responses for both terminals. Calling terminal A sends Commands (B) to Called terminal B and receives Responses (B) back. Similarly, Called terminal B sends Commands (A) to Calling terminal A and receives Responses (A) back. The diagram is labeled T0817580-94/d03. + +FIGURE 3/T.70 + +#### 3.3.2.3 Link layer implementation rules + +In order to achieve full compatibility between different implementations, the rules below for the implementation of Recommendation X.75 shall be followed. + +##### 3.3.2.3.1 General rules + +- a) The 1984 version (*Red Book*) of clause 2/X.75, shall be used as the reference specification. +- b) The term “STE” shall be read as “DTE”. +- c) At present the non-extended mode of operation (i.e. modulo 8) and the extended mode of operation (i.e. modulo 128) are defined. The support of modulo 8 is mandatory and modulo 128 is optional. However, the long term objective is to use modulo 128 as the common base modulo. Therefore, it is strongly recommended that the extended mode of operation (i.e. modulo 128) be supported, and the terminal supporting the extended mode shall also support the non-extended mode. +- d) Only the single link procedure (SLP) shall be used. + +##### 3.3.2.3.2 Specific rules + +The following rules refer to the indicated subclauses and tables of Recommendation X.75. + +- a) *Table 1/X.75* (see Note 1) +I-frame must not be sent with an empty I-field. + $N \geq 0$ + $N \leq N1 - 32$ +A received empty I-frame shall be treated as a valid I-frame. +- b) *Subclause 2.3.4.9* +Items 5), 6) and 7) are not valid (shall not result in the sending of a FRMR). Instead the following actions shall be implemented: + - Not expected supervisory frames with the F bit set to 1 shall be ignored. + - Not expected UA or DM response shall be ignored. + - Frames with an invalid N(S) shall be responded to by sending REJECT.Frames with an FRMR control field shall not be responded by sending a FRMR. +- c) *Table 7/X.75* +Bits W, X, Y and Z set to 0 indicate that no reason for frame rejection is given. +- d) *Subclause 2.3.5.3* +The DTE and the CSPDN are not octet aligned and the last paragraph is therefore not valid. +- e) *Subclause 2.3.5.5* +Higher layers should be notified when timer T3 expires (excessive idle state). +- f) *Subclause 2.4.3* +Related to the first paragraph, read instead of “next response” “corresponding response”. +- g) *Subclause 2.4.4.1* +In the active channel state, the DTE shall transmit contiguous flags independent of the other DTE. +The calling DTE shall initialize the link by sending a SABM command with the P bit set to 1. +- h) *Subclause 2.4.4.4.1* +A condition for entering the disconnected phase is also that no unacknowledged DISC command exists, because of collision cases (see 2.4.4.5/X.75). +In the disconnected phase, it is the calling DTE which may initiate link set up. +- i) *Subclause 2.4.5.9, fourth paragraph* +If an RNR is received, the DTE shall remain in the timer recovery condition (because the other DTE is still in the busy condition). +- j) *Subclause 2.4.5.9, fifth paragraph* +If an RNR is received, the DTE shall not resume I-frame transmission or retransmission. +- k) *Subclause 2.4.5.9, last paragraph* +If the transmission attempt variable is equal to N2, the DTE shall enter the disconnected phase. +- l) *Subclause 2.4.7.3* +In the frame rejection condition, the DTE shall only check the commands and react with an FRMR according to the P bit. +The frame rejection condition is cleared when the DTE receives an SABM, or, receives or transmits a DISC command. +- m) *Subclause 2.4.7.3, second paragraph* (see Note 2) +Only the DTE which caused the FRMR condition may try to reset the link. + +- n) *Subclause 2.4.7.3, third paragraph* (see Note 3) + +After N2 attempts to get the other DTE to reset the link, the DTE shall enter the disconnected phase. + +- o) *Subclause 2.4.8.1* (see Note 4) + +The timer T1 shall be started at the end of frame transmission. The value of T1 depends on the data signalling rate, the frame length, the value of N2, and a fixed time representing both T2 and the transmission delay [see item r)]. A value is recommended between 2.5 and 7 seconds. + +- p) *Subclause 2.4.8.2* (see Note 4) + +$$T1 > T2$$ + +$$T2 < 1 \text{ s}$$ + +Depending on the acknowledgement strategy used, the DTE designer may regard T2 as a decision parameter only, in which case the DTE is not obliged to implement a corresponding timer. + +- q) *Subclause 2.4.8.3, second paragraph* + +$$30 \text{ s} \leq T3 \leq 60 \text{ s}$$ + +- r) *Subclause 2.4.8.4* + +$$N2 \times T1 \geq 60 \text{ s}$$ + +- s) *Subclause 2.4.8.5* (see Note 5) + +For the non-extended mode, + +$$N1 = 1080 + (n \times 1024) \text{ bits; } n = 0 \text{ or } 1 \text{ or } 3 \text{ or } 7 \text{ or } 15.$$ + +For the extended mode, + +$$N1 = 1096 + (n \times 1024) \text{ bits; } n = 0 \text{ or } 1 \text{ or } 3 \text{ or } 7 \text{ or } 15.$$ + +- t) *Subclause 2.4.8.6* (see Note 5) + +For the non-extended mode, $k \leq 7$ . + +For the extended mode, $k \leq 127$ . + +###### NOTES + +1 Terminals complying with the *Red Book* version of this Recommendation may react by DL-RESET indication (FRMR). + +2 Terminals complying with the *Red Book* version of this Recommendation may react differently. + +3 It is not meaningful to reset the link if the other DTE is not responding for $N2 \times T1$ . + +4 The acknowledge strategy used by the receiving DTE should be independent of any knowledge about the value of $k$ used by the sending DTE. This can be achieved by acknowledging every correctly received I-frame as soon as possible. + +5 The selection of N1 and $k$ values should be performed so that adequate throughput performance can be achieved for a link with longer transmission delay. The recommended combination of N1 and $k$ values for a link having a higher data rate (e.g. 48 kbit/s or 64 kbit/s) are as follows: + +For the non-extended mode, $N1 = 16\,440$ ( $n = 15$ ) and $k = 7$ ; + +For the extended mode, $N1 = 16\,456$ ( $n = 15$ ) and $k = 80$ . + +### 3.3.3 Network layer procedure + +#### 3.3.3.1 Call control phase + +The call control procedure conforms to Recommendation X.21, or as an option, Recommendation X.22 for multi-call operation. + +#### 3.3.3.2 Data transfer phase + +A minimal network layer is present during the data transfer phase and accommodated through the use of a two-octet network block header. The header comprises a one-octet length indicator followed by a network block type code specified below. The only network block currently defined is a network protocol data block as shown in Figure 4. + +![](d4af765160d04ecef538e5066006dc77_img.jpg) + +| | | | | | | | | | | +|--------|--------|----------------------------|-----------------|-----------------|-----------------|-----------------|-----------------|-----------------|-----------------| +| | | Bits | | | | | | | | +| | | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| Octets | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 <sup>a)</sup> | +| | 2 | M <sup>b)</sup> | Q <sup>c)</sup> | 0 <sup>d)</sup> | 0 <sup>e)</sup> | 0 <sup>f)</sup> | 0 <sup>f)</sup> | 0 <sup>f)</sup> | 0 <sup>f)</sup> | +| | 3 to n | Network user<br>data field | | | | | | | | + +T0819200-94/d04 + +- a) The length indicator expresses in octets the length of the network data block header. This length does not include octet 1. +- b) The more data mark (M) is used to preserve the integrity of transport layer control and transport data blocks. When M is set to 1 it indicates that more data is to follow. A terminal has to accept as much bytes as the terminal can support by block size negotiation. Receiving more bytes the terminal may react by N-DISC indication. +- c) The qualifier bit (Q) is introduced to provide a functional mapping with the X.25 qualifier bit for CSPDN/PSPDN interworking. If the Q bit is not used it shall be set to zero. +- d) and e) are spare bits for possible new single bit functions. +- f) The bits 1 to 4 with the code four zeros (0000) are used to identify the network data block. Other network layer protocol unit types (i.e. control blocks used in the data transfer phase) may be defined in the future. The network user data field is delimited by the HDLC Closing Flag at the link layer. It must contain at least one octet. + +FIGURE 4/T.70 +**Network data block** + +#### 3.3.3.3 Data transfer procedure + +##### 3.3.3.3.1 Handling of the M-bit + +The calling DTE shall negotiate the TPDU size with the called DTE at the transport layer, based on either the maximum TPDU size supported or the optimum TPDU size for the specific call, unless the default value of 128 octets is used. The agreed value will allow the sending DTE to transfer TPDU's without the need for segmenting at the Network layer and consequently the M-bit is set to zero. + +However, receiving DTEs must always be capable of reassembling segmented TPDU's by using the M-bit, since segmenting may take place in the network in some interworking situations, e.g., when the composite network connection comprises a PSDN. + +##### 3.3.3.3.2 Error procedures + +A Data PDU with a length indicator different from hexadecimal "01" and/or with less than three octets shall be discarded and the physical network connection shall be cleared. + +## 3.4 Terminals connected to an ISDN + +See Recommendation T.90. + +# 4 Interworking between networks + +**4.1** It is the responsibility of Administrations to decide in which network(s) the telematic services are to be provided. + +**4.2** Four possibilities are considered below: + +- a) Terminals connected to a circuit switched public data network (CSPDN); +- b) Terminals connected to a packet switched public data network (PSPDN); +- c) Terminals connected to a public switched telephone network (PSTN); +- d) Terminals connected to an integrated services digital network (ISDN). + +**4.3** Interworking between telematic terminals connected to any network must be possible. + +**4.4** International interworking between telematic terminals shall preferably take place between networks of the same type when these networks are provided by both countries involved. + +**4.5** In the case of international interworking between telematic terminals connected to dissimilar networks, Recommendation X.300 shall apply. + +The interworking between CSPDNs and PSPDNs is described in Recommendation X.82 (detailed arrangements for interworking between CSPDNs and PSPDNs based on this Recommendation). + +# **5 Transport layer procedure** + +## **5.1 Transport functions** + +### **5.1.1 General** + +**5.1.1.1** The transport layer will perform all those functions that are necessary to bridge the gap between the services provided by the network layer and the services needed by the session layer. Therefore, the functions performed are dependent on two criteria: the services provided by the underlying network layer and the services required by the session layer. + +**5.1.1.2** It is the responsibility of the transport service user to select a given quality of service, which may imply the use of certain transport layer functions such as: + +- a) establishment of a transport connection + - transport connection identification + - transport connection multiplexing; +- b) data transfer + - sequence control + - error detection + - error recovery + - segmenting and reassembling + - flow control + - purge; +- c) termination of a transport connection. + +NOTE – Not all of the above functions will be available in the basic transport service (see 5.1.3). + +### **5.1.2 Transport protocol classes** + +**5.1.2.1** Transport layer functions are grouped (for ease of negotiation) into a hierarchical system of transport protocol classes whereby classes occupying superior positions in the hierarchy implement functions of the lower classes together with the optional functions identified for their own class. + +**5.1.2.2** During transport connection establishment the use of a given transport protocol and optional functions should be negotiated according to the following rules: + +- the calling terminal indicates the transport protocol class and (if applicable) the optional functions required; +- the called terminal indicates the transport protocol class and (if applicable) the optional functions that it is willing to support; +- all parameters to be used in the transport connection must be explicitly indicated, otherwise default values will apply. + +**5.1.2.3** The basic transport service described here is fulfilled by a protocol denoted in Recommendation X.224 as transport protocol class 0. That protocol class is compatible with this Recommendation. In the event of a discrepancy between transport protocol class 0 as described in Recommendation X.224 and in this Recommendation, the latter takes precedence. + +### **5.1.3 The basic transport service (TS)** + +**5.1.3.1** A limited set of transport layer functions is defined for a basic transport service. The basic transport service is provided by transport layer functions which are performed by *transport layer protocol elements*. + +**5.1.3.2** Transport protocol data units (TPDUs) carrying transport service (TS) user information or control information are called *blocks*. + +**5.1.3.3** Transport layer block types are as follows: + +- a) transport connection request (TCR) block; +- b) transport connection accept (TCA) block; +- c) transport connection clear (TCC) block; +- d) transport data (TDT) block; +- e) transport block reject (TBR) block. + +**5.1.3.4** The TCR and TCA blocks are used to indicate the protocol class, and optional functions, applying to a transport connection. The TCC block is used to indicate the reason for refusing a connection establishment. The TDT block carries information of the transport service user. The TBR block is used to report procedure errors to the remote terminal. + +### **5.1.4 Transport layer functions** + +**5.1.4.1** Basic class functions and associated transport layer protocol elements, i.e. blocks, include: + +- a) transport connection establishment, transport connection identification, optional extended addressing and optional transport data block size negotiation (TCR, TCA and TCC blocks); +- b) data delimitation, segmentation/reassembling of arbitrarily long transport service data units (TSDU). These are contained within TDT blocks. The end of a TSDU is indicated by a TSDU end mark in the last data block; +- c) detection and indication of procedural errors (TBR block). + +**5.1.4.2** Other characteristics of the basic transport service are: + +- a) Maintenance of TSDU integrity. +- b) *Overflow* – If the user cannot absorb new data and if the appropriate buffers are not available, flow control is performed at the network/link layer as appropriate. +- c) *Error* – No mechanism is provided within the transport layer to facilitate recovery from detected errors. Where such errors are detected the user of the transport service should be informed so that appropriate recovery action may be taken. + +## **5.2 Description of connection establishment and termination procedures** + +### **5.2.1 General** + +**5.2.1.1** The transport layer connection establishment and termination procedures shall also be used for negotiating transport protocol class and, if applicable, optional transport connection functions. + +**5.2.1.2** For the basic transport service, means are provided to establish a transport connection using a TCR block and a TCA block. This exchange provides: + +- a) a way to negotiate options; +- b) a transport connection identification. The transport connection is identified by use of cross-references. Each end of the connection is responsible for selecting a suitable transport connection identifier. + +**5.2.1.3** This mechanism also provides an identification of the transport connection independent of any network connection identification and therefore provides independence from the life of the network connection. The binary value 0 should not be used as an identifier. The use of such references for reconnection requires further definition. + +### **5.2.2 Transport connection request (TCR) block** + +**5.2.2.1** The calling terminal shall indicate a transport connection request by transferring a TCR block to the remote terminal. The TCR block includes the transport functions (e.g. source reference, class, and optional functions) for negotiation of the characteristics of the transport connection being established. + +### **5.2.3 Transport connection accept (TCA) block** + +**5.2.3.1** The called terminal shall indicate its acceptance of the transport connection by transferring a TCA block to the remote terminal. The TCA block includes the transport parameters applying to the connection and to be used by the calling terminal. + +**5.2.3.2** If a terminal receives the request for an optional TDT block size it may either: + +- indicate its support by reproducing the requested value in the TCA block; +- request in the TCA block the use of a shorter allowable TDT block. The calling side either accepts this size by sending the first TDT block or disconnects the network connection; +- not accept the requested TDT block size parameter value by sending a TCA block without a TDT block size parameter. Therefore, the standardized TDT block size will apply. + +A TCR requesting an optional TDT block size not supported by the called side should not be answered with TBR. + +### **5.2.4 Transport connection clear (TCC) block** + +**5.2.4.1** If a transport connection cannot be established, the called terminal shall respond to the TCR block with a TCC block. The clearing cause shall indicate why the connection was not accepted. + +It is up to the calling side whether the receipt of a TCC will cause complete disconnection or whether a new TCR with a parameter different from the first one will be sent (e.g. another extended transport layer address). In order to allow for subsequent TCRs, the sender of TCC may provide in the optional parameter field an appropriate parameter and associated value to indicate that another TCR is invited. The new optional parameter and its associated value(s) are for further study. + +NOTE – There is no explicit transport connection termination procedure in this Recommendation. Therefore, the lifetime of the transport connection is directly correlated to the lifetime of the supporting network connection. + +### **5.2.5 Transport connection collision** + +**5.2.5.1** If the calling terminal receives a TCR block, it shall transfer a TBR block to notify the called terminal of the procedure error (see Annex B). + +### **5.2.6 Extended addressing** + +**5.2.6.1** The extended addressing capability may be used to address terminals in a multiterminal configuration. + +The extension addresses for called and calling terminals are optional parameters to TCR and TCA. The use of the calling extension address is for further study. + +**5.2.6.2** The receiving terminal shall respond with a TCA according to Table 1. + +**5.2.6.3** The calling terminal may, when receiving a called terminal address in the TCA, act as specified in Table 2. + +TABLE 1/T.70 + +| Received TCR | Receiver reaction | | +|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------|-----------------------------------------| +| | Multi-terminal<br>with extended addressing <sup>a)</sup> | Stand-alone terminal | +| Without extended addressing | Send TCA<br>with extended addressing | Send TCA<br>without extended addressing | +| With extended addressing | Send TCA<br>with extended addressing <sup>b)</sup> | Send TCA<br>without extended addressing | +| <sup>a)</sup> Multi-terminal configuration, with capability for extended addressing.<br><sup>b)</sup> If the called terminal is occupied or out of order, the call should be routed to a default terminal or mailbox. The sender will then be informed of the routing by the extension address of the connected terminal. The receiver of TCR may also in this case react by sending TCC. | | | + +TABLE 2/T.70 + +| Sent TCR | Calling terminal reaction | | | +|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------|--------------------------------|----------------------------------| +| | TCA received with: | | | +| | No extended<br>addressing | Correct extended<br>addressing | Incorrect extended<br>addressing | +| Without extended addressing | OK | Neglect extension<br>(Note) | | +| With extended addressing | <sup>a)</sup> | OK | <sup>a)</sup> | +| <sup>a)</sup> Reaction left to the discretion of the calling terminal.<br>NOTE – Terminal complying with the 1980-1984 version of this Recommendation may react by releasing the network connection. | | | | + +## 5.3 Description of data transfer procedures + +### 5.3.1 General + +**5.3.1.1** The data transfer procedure described in the following subclauses applies only when the transport layer is in the data transfer phase, i.e. after completion of transport connection establishment and prior to clearing. + +NOTE – When a connection is cleared, transport data blocks may be discarded. Hence it is left to the transport service user to define protocols able to cope with the various possible situations that may occur. + +### 5.3.2 Transport data block (TDT) length + +**5.3.2.1** The standard maximum TDT block length to be supported by all terminals is 128 octets including the data block header octets. However, the TDT block length may be restricted to a lower value when the TDT block is concatenated with other TDT blocks (see 5.5.3). + +**5.3.2.2** Other maximum data field lengths may be supported in conjunction with an optional TDT block size negotiation connection function (see 5.5.4.3 and 5.5.5.3). Optional maximum data field lengths shall be chosen from the following: 256, 512, 1024 and 2048 octets. If the requested optional TDT block size cannot be supported, a shorter allowable TDT block size must be selected (see 5.2.3.2). + +The agreed maximum TDT block size should be aimed at for TDT blocks having the TSDU end mark set to 0 and a number of octets less than the agreed maximum shall not cause the receiving transport entity to reject this TDT block. + +**5.3.2.3** The selection of the maximum TDT length should be performed so that adequate throughput performance can be achieved for a link with a longer transmission delay. + +### **5.3.3 Transport service data unit (TSDU) end** + +**5.3.3.1** The TSDU end mark is used to preserve the integrity of the TSDU. The TSDU end mark is set to binary 1 in the last TDT data block carrying information related to a certain TSDU. Exceptionally, this TDT block may be sent without carrying user information in order to allow for an immediate termination of a TSDU in certain error conditions. + +In case of a TSDU that comprises a single TDT block the TSDU end mark is also set to 1. In all other cases the TSDU end mark is set to zero. + +## **5.4 Treatment of procedure errors** + +**5.4.1** A terminal shall send a TBR block to the remote terminal to report the receipt of an invalid or not implemented block (if not explicitly specified otherwise in this Recommendation). During the establishment of a transport connection, terminals shall not send a TBR block upon the receipt of a TCR block whose parameters or parameter values are invalid or not implemented. In this case, terminals shall act as if no errors have occurred and send the appropriate response (if any). + +A terminal receiving a TBR block shall take appropriate recovery action. + +###### NOTES + +- 1 A TBR whether invalid or valid shall not be answered by sending a TBR block. +- 2 Terminals complying with the 1981-1984 study period version of this Recommendation may react to all of the above indicated conditions by sending TBR. +- 3 The definition of invalid block/parameter, etc. is provided by the state transition tables (see Annex B). +- 4 A TCR of which the PV of the TPDU size parameter is less than 07 (which is the basic length of the transport block size) shall be considered as an invalid TPDU. +- 5 In the states 1.1 for the calling side and 2.1 for the calling and called side the terminal may react either by sending TBR or by releasing the network connection. +- 6 The state tables and state transition diagrams have to be read according to Notes 4 and 5 above. + +## **5.5 Formats** + +### **5.5.1 General** + +**5.5.1.1** Transport protocol data units (TPDUs) carrying transport service (TS) user information or control information are called *blocks* (see 5.1.3). All blocks contain an integral number of octets. + +**5.5.1.2** Bits of an octet are numbered 8 to 1 where bit 1 is the low order bit and is transmitted first. Octets of a block are consecutively numbered starting from 1 and are transmitted in this order. + +When consecutive octets are used to represent a binary number, the lower octet has the most significant value. + +**5.5.1.3** *TDT block(s)* are used to transfer a transport service data unit (TSDU) transparently whilst maintaining the structure of the latter by means of the TSDU end mark. + +**5.5.1.4** *Control blocks* (TCR, TCA, TCC, TBR) are used to control the transport protocol functions, including optional functions. + +**5.5.1.5** A parameter field is present in all control blocks within the basic transport service to indicate optional functions. The parameter field contains one or more parameter elements. The first octet of each parameter element contains a parameter code to indicate the function(s) requested. + +The general coding structure is shown in Figure 5. + +![Diagram showing the parameter element coding structure. It is a table with 8 bits per octet. Octet 1 contains the parameter code. Octet 2 contains the parameter length indicator. Octets 3 through n contain the parameter value.](dfe556fea00682b09a59427aaf72051c_img.jpg) + +| | | | | | | | | | +|-----|----------------------------|---|---|---|---|---|---|---| +| | Bits | | | | | | | | +| | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| 1 | Parameter code | | | | | | | | +| 2 | Parameter length indicator | | | | | | | | +| 3 | Parameter value | | | | | | | | +| ... | | | | | | | | | +| n | | | | | | | | | + +T0819210-94/d05 + +Diagram showing the parameter element coding structure. It is a table with 8 bits per octet. Octet 1 contains the parameter code. Octet 2 contains the parameter length indicator. Octets 3 through n contain the parameter value. + +FIGURE 5/T.70 +**Parameter element coding structure** + +**5.5.1.6** The parameter code field is binary coded and, without extension, provides for a maximum of 255 parameters. Parameter code 11111111 is reserved for extension of the parameter code. The extension mechanism is for further study. + +Octet 2 indicates the length, in octets, of the parameter value field. The parameter field length is binary coded and bit 1 is the low order bit of this indicator. + +Octet 3 and subsequent octets contain the value of the parameter identified in the parameter code field. The coding of the parameter value field is dependent on the function being requested. + +### **5.5.2 Structure of transport control and transport data blocks** + +**5.5.2.1** Figure 6 illustrates the general structure of transport layer blocks. A summary of transport layer blocks is given in Figure 7. + +![Diagram showing the general structure of transport layer blocks. It is a table with 4 columns: Length indicator (Octet 1, 8 bits), Block type (Octet 2, 1 bit), Functional code field (fixed format) (Octet 3 ... Octet N), and Parameter or data field (variable format) (Octet N + 1 ... Octet M).](3fa8bfee86764e3c3a1a6fbbe61bbd52_img.jpg) + +| | | | | | +|------|------------------|------------|--------------------------------------|-------------------------------------------| +| | Octet 1 | Octet 2 | Octet 3 ... Octet N | Octet N + 1 ... Octet M | +| Bits | 8 | 1 | | | +| | Length indicator | Block type | Functional code field (fixed format) | Parameter or data field (variable format) | + +T0819220-94/d06 + +Diagram showing the general structure of transport layer blocks. It is a table with 4 columns: Length indicator (Octet 1, 8 bits), Block type (Octet 2, 1 bit), Functional code field (fixed format) (Octet 3 ... Octet N), and Parameter or data field (variable format) (Octet N + 1 ... Octet M). + +FIGURE 6/T.70 +**General block structure** + +#### **5.5.2.2 Length indicator (LI) field** + +**5.5.2.2.1** Octet 1 contains the length indicator (LI). The value of this indicator is a binary number that represents the length in octets of the control block (including parameters) and the header length in octets of data blocks (excluding any subsequent user information). In both cases this length does not include octet 1. + +**5.5.2.2.2** The basic LI value shall be restricted to 127 (i.e. a binary value of 01111111). The use of higher LI values and the use of the binary value 11111111 for extension purposes is for further study. + +#### 5.5.2.3 Block type field + +**5.5.2.3.1** Octet 2 contains the block type code. Bits 1 to 4 of octet 2 are set to 0 for all transport layer blocks currently defined. It is for further study to determine whether or not bits 1 to 4 are required for future extension to the range of transport layer blocks currently defined or are used for other functions. + +#### 5.5.2.4 Functional code field + +**5.5.2.4.1** Octet 3 and subsequent octets contain functional codes in a fixed format as per the block type (see Figure 7). + +| | Octet 1 | Octet 2 | Octet 3 | Octet 4 | Octet 5 | Octet 6 | Octet 7 | +|-----|---------|----------|-----------------------|----------|------------------|----------------|------------| +| TCR | Length | 11100000 | 00000000 | 00000000 | Source reference | 00000000 | Parameters | +| TCA | Length | 11010000 | Destination reference | | Source reference | 00000000 | Parameters | +| TCC | Length | 10000000 | Destination reference | | Source reference | Clearing cause | Parameters | +| TBR | Length | 01110000 | Destination reference | | Reject cause | | Parameters | +| TDT | Length | 11110000 | 00000000 | | | | Data | + +↑ TSDU end mark + +T0817590-94/d07 + +NOTE – The terms “source” and “destination” refer to the initiator and the recipient of the transport protocol data unit (TPDU), respectively. The value of the “source reference” is a local system parameter. The source reference of a received transport block is to be used as destination reference in the response to that transport block. + +FIGURE 7/T.70 +Transport layer block types + +#### 5.5.2.5 Parameter or TSDU field + +**5.5.2.5.1** A parameter field or a data field containing transport service (TS) user data may optionally follow the functional code field. + +### 5.5.3 Concatenation + +**5.5.3.1** Concatenation of transport control and/or transport data blocks is currently not applicable to this Recommendation. However, where concatenation is used in the future, the arrangement shown in Figure 8 would apply. + +### 5.5.4 Transport connection request (TCR) block format + +**5.5.4.1** Figure 9 illustrates the format of the TCR block. + +#### 5.5.4.2 Parameters for extended addressing + +Separate parameters are provided for the indication of called and calling extension addresses. The coding of these parameters is shown in Figure 10. The setting of bit 8 for extended addressing should be ignored by the transport layer. + +The use of more than one called extension address is for further study. + +#### 5.5.4.3 Parameter for transport data block size negotiation + +This parameter defines the proposed maximum transport data block size (in octets including the transport data block header) to be used over the requested transport connection. The coding of this parameter is shown in Figure 11. + +![](b6671cfafda3820aafe9a24fa7a4d8c7_img.jpg) + +Bits + +| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | | +|-----------------------------------------------------------|---|---|---|---|---|---|---|------------------------------| +| HDLC flag | | | | | | | | {<br>Link level | +| HDLC address field | | | | | | | | | +| HDLC control field | | | | | | | | | +| Network header (e.g. Rec. X.25 or as per subclause 3.3.3) | | | | | | | | {<br>Network level | +| Transport control block | | | | | | | | | +| Transport control block | | | | | | | | {<br>Transport level | +| • | | | | | | | | | +| • | | | | | | | | | +| • | | | | | | | | | +| Transport data block header | | | | | | | | {<br>Session level and above | +| Transport user data | | | | | | | | | +| • | | | | | | | | | +| • | | | | | | | | | +| • | | | | | | | | {<br>Link level | +| HDLC frame check-sequence | | | | | | | | | +| HDLC flag | | | | | | | | | + +T0819230-94/d08 + +NOTE – This figure does not imply that a transport data or control block will fit within a single network data block. + +FIGURE 8/T.70 +Information field structure of HDLC I-frame (example) + +![](5b8a756d9a71c35f17db8bcb90b438a3_img.jpg) + +| | | Bits | | | | | | | | | | | | | | | +|--------|---|-------------------------------------|---|---|---|---|---|---|-----------------|--|--|--|--|--|--|--| +| | | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | | | | | | | | +| Octets | 1 | Length (octets) | | | | | | | | | | | | | | | +| | 2 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 <sup>a)</sup> | | | | | | | | +| | 3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 <sup>b)</sup> | | | | | | | | +| | 4 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 <sup>b)</sup> | | | | | | | | +| | 5 | Source | | | | | | | | | | | | | | | +| | 6 | reference | | | | | | | | | | | | | | | +| | 7 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 <sup>c)</sup> | | | | | | | | +| | 8 | Parameters <sup>d)</sup> (optional) | | | | | | | | | | | | | | | +| ... | | | | | | | | | | | | | | | | | +| n | | | | | | | | | | | | | | | | | + +T0819240-94/d09 + +- a) Block type: TCR. +- b) Octets 3 and 4 are not used and shall be set to zero. +- c) Transport service extension field: Octet 7 is reserved for any future extension such as providing for a range of transport service classes. In the basic transport service this octet shall be set to zero. +- d) The parameter field is present only when the terminal is requesting an optional transport connection function. + +FIGURE 9/T.70 +**Transport connection request block** + +![](79e1709a7317ead45379cbb8ff3ba802_img.jpg) + +| | | Bits | | | | | | | | +|--------|---|----------------------------------|---|---|---|---|---|---|---| +| | | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| Octets | 1 | Extension address parameter type | | | | | | | | +| | 2 | Parameter length indicator | | | | | | | | +| | 3 | IA5 digit | | | | | | | 1 | +| | | IA5 digit | | | | | | | 2 | +| | | | | | | | | | • | +| | | | | | | | | | • | +| | | | | | | | | | • | +| | | | | | | | | | n | + +} 11000001 for calling address type + or 11000010 for called address type + +T0819250-94/d10 + +FIGURE 10/T.70 +**Extended addressing** + +![](e69b9188aa2c14ec6b21c83f711fef65_img.jpg) + +| | | Bits | | | | | | | | | +|--------|---|------|---|---|---|---|---|---|---|-----------------------------| +| | | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | | +| Octets | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | } Parameter type code | +| | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | | +| | 3 | 0 | 0 | 0 | 0 | X | X | X | X | } Transport data block size | + +T0819260-94/d11 + + + +| | | | | +|------|---|-----------|-------------| +| XXXX | { | 1 0 1 1 = | 2048 octets | +| | | 1 0 1 0 = | 1024 octets | +| | | 1 0 0 1 = | 512 octets | +| | | 1 0 0 0 = | 256 octets | +| | | 0 1 1 1 = | 128 octets | + +FIGURE 11/T.70 +Transport data block size parameter + +### 5.5.5 Transport connection accept (TCA) block format + +5.5.5.1 Figure 12 illustrates the format of the TCA block. + +![](09955ff8214ffb6947951fc0f60eb6ab_img.jpg) + +| | | Bits | | | | | | | | +|--------|---|-------------------------------------|---|---|---|---|---|---|-----------------| +| | | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| Octets | 1 | Length (octets) | | | | | | | | +| | 2 | 1 | 1 | 0 | 1 | 0 | 0 | 0 | 0 <sup>a)</sup> | +| | 3 | Destination | | | | | | | | +| | 4 | reference | | | | | | | | +| | 5 | Source | | | | | | | | +| | 6 | reference | | | | | | | | +| | 7 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 <sup>b)</sup> | +| | 8 | Parameters (optional) <sup>c)</sup> | | | | | | | | +| n | | | | | | | | | | + +T0819270-94/d12 + +- a) Block type: TCA. +- b) Transport service extension field; Octet 7 is reserved for any future extension such as providing for a range of transport service classes. In the basic transport service this octet shall be set to zero irrespective of the setting in the TCR block. +- c) The parameter field is present only when the terminal is requesting or confirming an optional transport connection function. + +FIGURE 12/T.70 +Transport connection accept block + +#### 5.5.5.2 Parameters for extended addressing + +See 5.5.4.2. + +#### 5.5.5.3 Parameter for transport data block size negotiation + +See 5.5.4.3. The parameter value shall be equal to or less than the value specified in the TCR block. + +### 5.5.6 Transport connection clear (TCC) block format + +5.5.6.1 Figure 13 illustrates the format of the TCC block. + +![Diagram of the Transport Connection Clear (TCC) block format. The block is 8 octets long. Octet 1: Length (octets) = 8. Octet 2: 1 0 0 0 0 0 0 0^a). Octet 3: Destination reference. Octet 4: Source reference. Octet 5: Clearing cause^b). Octet 6: Parameter (optional). Octet 7: Parameter (optional). Octet 8: Parameter (optional).](ab846b81e78dbc8da2a6f9511e2f248a_img.jpg) + +Bits + +8 7 6 5 4 3 2 1 + +Octets + +1 Length (octets) + +2 1 0 0 0 0 0 0<sup>a)</sup> + +3 Destination + +4 reference + +5 Source + +6 reference + +7 Clearing cause<sup>b)</sup> + +8 Parameter (optional) + +n + +T0819280-94/d13 + +Diagram of the Transport Connection Clear (TCC) block format. The block is 8 octets long. Octet 1: Length (octets) = 8. Octet 2: 1 0 0 0 0 0 0 0^a). Octet 3: Destination reference. Octet 4: Source reference. Octet 5: Clearing cause^b). Octet 6: Parameter (optional). Octet 7: Parameter (optional). Octet 8: Parameter (optional). + +| | | | +|----|---------------------------|-------------------| +| a) | Block type: TCC. | Bits | +| b) | Clearing cause: | 8 7 6 5 4 3 2 1 | +| | 0 – Reason not specified | = 0 0 0 0 0 0 0 0 | +| | 1 – Terminal occupied | = 0 0 0 0 0 0 0 1 | +| | 2 – Terminal out of order | = 0 0 0 0 0 0 1 0 | +| | 3 – Address unknown | = 0 0 0 0 0 0 1 1 | + +FIGURE 13/T.70 +Transport connection clear block + +#### 5.5.6.2 Parameter for additional clearing information + +This parameter is provided to allow additional information relating to the clearing of the connection. The coding of this parameter is given in Figure 14. + +### 5.5.7 Transport block reject (TBR) block format + +5.5.7.1 Figure 15 illustrates the format of the TBR block. + +Bits + +| Octets | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | | +|--------|----------------------------|---|---|---|---|---|---|---|------------------| +| 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | } Parameter code | +| 2 | Parameter length indicator | | | | | | | | | +| 3 | Additional information | | | | | | | | | +| n | | | | | | | | | | + +T0819290-94/d14 + +FIGURE 14/T.70 +**Additional clearing information parameter** + +Bits + +| Octets | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +|--------|----------------------------|---|---|---|---|---|---|-----------------| +| 1 | Length (octets) | | | | | | | | +| 2 | 0 | 1 | 1 | 1 | 0 | 0 | 0 | 0 <sup>a)</sup> | +| 3 | Destination<br>reference | | | | | | | | +| 4 | | | | | | | | | +| 5 | Reject cause <sup>b)</sup> | | | | | | | | +| 6 | Parameter field | | | | | | | | +| n | | | | | | | | | + +T0819300-94/d15 + +<sup>a)</sup> Block type: TBR. + +<sup>b)</sup> Reject cause: + +| | | +|------------------------------|-------------------| +| | Bits | +| | 8 7 6 5 4 3 2 1 | +| 0 – Reason not specified | = 0 0 0 0 0 0 0 0 | +| 1 – Function not implemented | = 0 0 0 0 0 0 0 1 | +| 2 – Invalid block | = 0 0 0 0 0 0 1 0 | +| 3 – Invalid parameter | = 0 0 0 0 0 0 1 1 | + +FIGURE 15/T.70 +**Transport block reject block** + +20       **Recommendation T.70 (03/93)** + +#### 5.5.7.2 Rejected block parameter (mandatory) + +This parameter is used to indicate the bit pattern of the rejected block up to and including the octet that caused the rejection. Only the first detected procedural error or parameter, which cannot be acted upon, shall be indicated by this method. The coding of this parameter is given in Figure 16. + +![](552265bdbcf6d43d341fd018a9076269_img.jpg) + +| | | Bits | | | | | | | | +|--------|---|----------------------------|---|---|---|---|---|---|---| +| | | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| Octets | 1 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | +| | 2 | Parameter length indicator | | | | | | | | +| | 3 | Rejected information | | | | | | | | +| | n | | | | | | | | | + +T0819310-94/d16 + +FIGURE 16/T.70 + +### 5.5.8 Transport data block (TDT) format + +5.5.8.1 Figure 17 illustrates the format of the TDT block. + +![](2734e7f9be3e1dc046f14be2e6c9a085_img.jpg) + +| | | Bits | | | | | | | | +|--------|---|------------------------|---|---|---|---|---|---|-----------------| +| | | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| Octets | 1 | Length (octets) | | | | | | | | +| | 2 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 <sup>a)</sup> | +| | 3 | TSDU end <sup>b)</sup> | 0 | 0 | 0 | 0 | 0 | 0 | 0 | +| | 4 | Data | | | | | | | | +| n | | | | | | | | | | + +T0819320-94/d17 + +a) Block type: TDT. + +b) TSDU end: indicates the end of TSDU when set to 1. + +FIGURE 17/T.70 +Transport data block + +# Annex A + +(This annex forms an integral part of this Recommendation) + +## A.1 Transport and network service + +The transport service (TS) is provided by the transport protocol (TP) making use of the services available from the network layer. This annex also defines the TS characteristics which the TS users may exploit. + +Interactions between TS users and the TS provider take place at the two TS access points (TSAP) (see Figures A.1 to A.6). Information is passed between a TS user and a TS provider by means of primitives, which may convey parameters. + +Primitives are abstract representations of interactions. They are solely descriptive and do not represent a specification or implementation. + +The occurrence of a primitive is a logically instantaneous and indivisible event. The event occurs at a logically separate instant, which cannot be interrupted by another event. Only primitives of global significance are mentioned (having an impact on the remote user). + +The following types of primitives are defined: + +- a) request primitive; +- b) indication primitive; +- c) response primitive; +- d) confirm primitive. + +The primitives a) and c) are directed from the service user to the service provider, b) and d) are going in the opposite direction. + +“Transport” is designated by T, “Network” is designated by N. The terms CONNECT, DATA, DISCONNECT as part of a primitive name indicate that the primitive is used for establishment, data transfer, release of a transport connection (TC) or network connection (NC). + +*Examples:* + +| | | +|-------------------------|-------------------------------------------| +| T-CONNECT request | Request to establish a TC. | +| T-DATA request | Request to transmit TS user data. | +| N-DISCONNECT indication | Indication that the NC has been released. | + +The relationship between valid sequences of TS primitives and the appropriate protocol elements is shown in Figures A.1 to A.6. The sequences of valid network service (NS) primitives are illustrated in Figures A.7 to A.12. + +### A.1.1 Transport service + +The interactions shown in Figures A.1 to A.6 are not exhaustive. + +#### A.1.1.1 Transport connection establishment + +![Sequence diagram for successful TC establishment showing messages between TS user, TS provider, and TS user.](043e64d41a3368d138ace3816fd26469_img.jpg) + +``` + +sequenceDiagram + participant U1 as TS user + participant P as TS provider + participant U2 as TS user + + U1->>P: T-CONNECT request + Note over P: TSAP + P->>P: TCR + P->>U2: T-CONNECT indication + Note over P: TSAP + U2->>P: T-CONNECT response + P->>P: TCA + P->>U1: T-CONNECT confirm + +``` + +TS user TS provider TS user + +T-CONNECT request + +TCR + +T-CONNECT indication + +T-CONNECT response + +TCA + +T-CONNECT confirm + +TSAP TSAP + +T0817600-94/d18 + +Sequence diagram for successful TC establishment showing messages between TS user, TS provider, and TS user. + +FIGURE A.1/T.70 +Successful TC establishment + +![Sequence diagram for rejection of TC establishment by TS user showing messages between TS user, TS provider, and TS user.](2ae3eae1bd80a90f192f568ae246a9a6_img.jpg) + +``` + +sequenceDiagram + participant U1 as TS user + participant P as TS provider + participant U2 as TS user + + U1->>P: T-CONNECT request + Note over P: TSAP + P->>P: TCR + P->>U2: T-CONNECT indication + Note over P: TSAP + U2->>P: T-DISCONNECT request + P->>P: TCC + P->>U1: T-DISCONNECT indication + +``` + +TS user TS provider TS user + +T-CONNECT request + +TCR + +T-CONNECT indication + +T-DISCONNECT request + +TCC + +T-DISCONNECT indication + +TSAP TSAP + +T0817610-94/d19 + +Sequence diagram for rejection of TC establishment by TS user showing messages between TS user, TS provider, and TS user. + +FIGURE A.2/T.70 +Rejection of TC establishment by TS user + +#### A.1.1.2 Transfer phase + +![Sequence diagram for T-DATA transfer showing messages between TS user, TS provider, and TS user.](088921fa3f5a44c8551815122517eefd_img.jpg) + +``` + +sequenceDiagram + participant U1 as Calling or called + participant P as TS provider + participant U2 as Calling or called + + U1->>P: T-DATA request + Note over P: TSAP + P->>U2: TDT (EM = 0) + P->>U2: TDT (EM = 0) + P->>U2: TDT (EM = 0) + P->>U2: TDT (EM = 1) + Note over P: TSAP + U2->>P: T-DATA indication + +``` + +Calling or called Calling or called + +T-DATA request + +TDT (EM = 0) + +TDT (EM = 0) + +TDT (EM = 0) + +TDT (EM = 1) + +T-DATA indication + +TS user TS provider TS user + +TSAP TSAP + +T0817620-94/d20 + +Sequence diagram for T-DATA transfer showing messages between TS user, TS provider, and TS user. + +NOTE – This is one method of realizing segmenting/reassembling. + +FIGURE A.3/T.70 +T-DATA transfer + +#### A.1.1.3 Transport service error reporting + +![Sequence diagram for Transport service error reporting showing T-EXCEPTION indication between TS user and TS provider.](d17aa1fcc3b86503ad1dd0717a6c34c2_img.jpg) + +``` +sequenceDiagram + participant TS_user1 as TS user + participant TS_provider as TS provider + participant TS_user2 as TS user + TS_provider->>TS_user1: T-EXCEPTION indication + TS_provider->>TS_user2: T-EXCEPTION indication + Note over TS_provider: T0817630-94/d21 +``` + +The diagram illustrates the transport service error reporting process. It shows three vertical lifelines: 'TS user' on the left, 'TS provider' in the center, and 'TS user' on the right. Below each lifeline is the label 'TSAP'. Message arrows labeled 'T-EXCEPTION indication' point from the 'TS provider' outward to both the left and right 'TS users'. A reference code 'T0817630-94/d21' is located at the bottom right of the diagram. + +Sequence diagram for Transport service error reporting showing T-EXCEPTION indication between TS user and TS provider. + +NOTE – The use of this primitive is optional. + +FIGURE A.4/T.70 + +##### Transport service error reporting + +#### A.1.1.4 TC release + +At present only the implicit release of TC is defined (see 5.2.4.1). + +![Sequence diagram for TC release initiated by TS user showing T-DISCONNECT request and indication.](805c475f0859e607af0530ba43194bf1_img.jpg) + +``` +sequenceDiagram + participant TS_user1 as TS user + participant TS_provider as TS provider + participant TS_user2 as TS user + TS_user1->>TS_provider: T-DISCONNECT request + TS_provider->>TS_user2: T-DISCONNECT indication + Note over TS_provider: T0817640-94/d22 +``` + +The diagram illustrates the TC release process initiated by the TS user. It shows three vertical lifelines: 'TS user' on the left, 'TS provider' in the center, and 'TS user' on the right. Below each lifeline is the label 'TSAP'. A message arrow labeled 'T-DISCONNECT request' points from the left 'TS user' to the 'TS provider'. Another message arrow labeled 'T-DISCONNECT indication' points from the 'TS provider' to the right 'TS user'. A reference code 'T0817640-94/d22' is located at the bottom right of the diagram. + +Sequence diagram for TC release initiated by TS user showing T-DISCONNECT request and indication. + +FIGURE A.5/T.70 + +##### TC release initiated by TS user + +![Sequence diagram for TC release initiated by the TS provider showing T-DISCONNECT indication.](7a02de7ed198501f7a4f6ca37c3f28c5_img.jpg) + +``` +sequenceDiagram + participant TS_user1 as TS user + participant TS_provider as TS provider + participant TS_user2 as TS user + TS_provider->>TS_user1: T-DISCONNECT indication + TS_provider->>TS_user2: T-DISCONNECT indication + Note over TS_provider: T0817650-94/d23 +``` + +The diagram illustrates the TC release process initiated by the TS provider. It shows three vertical lifelines: 'TS user' on the left, 'TS provider' in the center, and 'TS user' on the right. Below each lifeline is the label 'TSAP'. A message arrow labeled 'T-DISCONNECT indication' points from the 'TS provider' to the left 'TS user'. Another message arrow labeled 'T-DISCONNECT indication' points from the 'TS provider' to the right 'TS user'. A reference code 'T0817650-94/d23' is located at the bottom right of the diagram. + +Sequence diagram for TC release initiated by the TS provider showing T-DISCONNECT indication. + +FIGURE A.6/T.70 + +##### TC release initiated by the TS provider + +### A.1.2 Network service + +Figures A.7 to A.12 show the relationships of network service (NS) primitives at both sides of an NC. + +#### A.1.2.1 Network connection establishment + +![Sequence diagram for successful network connection establishment (NC establishment).](2bacc162a73d75c43a7f90715832bd13_img.jpg) + +Sequence diagram illustrating the successful establishment of a Network Connection (NC) between an NS user and an NS provider. + +The diagram shows three lifelines: NS user, NS provider, and NS user. The NS user initiates the process by sending an N-CONNECT request to the NS provider. The NS provider then sends an N-CONNECT indication to the NS user. The NS user responds with an N-CONNECT response to the NS provider. Finally, the NS provider sends an N-CONNECT confirm to the NS user. + +NS user      NS provider      NS user + +N-CONNECT request + +N-CONNECT indication + +N-CONNECT response + +N-CONNECT confirm + +NSAP      NSAP + +T0817660-94/d24 + +Sequence diagram for successful network connection establishment (NC establishment). + +FIGURE A.7/T.70 +Successful NC establishment + +![Sequence diagram for rejection of network connection establishment (NC establishment) by the NS user.](28d75f39a24203712ee907b32cf0bbe5_img.jpg) + +Sequence diagram illustrating the rejection of a Network Connection (NC) establishment by the NS user. + +The diagram shows three lifelines: NS user, NS provider, and NS user. The NS user initiates the process by sending an N-CONNECT request to the NS provider. The NS provider then sends an N-CONNECT indication to the NS user. The NS user responds with an N-DISCONNECT request to the NS provider. Finally, the NS provider sends an N-DISCONNECT indication to the NS user. + +NS user      NS provider      NS user + +N-CONNECT request + +N-CONNECT indication + +N-DISCONNECT request + +N-DISCONNECT indication + +NSAP      NSAP + +T0817670-94/d25 + +Sequence diagram for rejection of network connection establishment (NC establishment) by the NS user. + +FIGURE A.8/T.70 +Rejection of NC establishment by NS user + +#### A.1.2.2 Network data transfer + +![Sequence diagram for network data transfer (N-DATA transfer).](f0a97d0d3818a253c1d2a009966081b1_img.jpg) + +Sequence diagram illustrating the Network Data (N-DATA) transfer between an NS user and an NS provider. + +The diagram shows three lifelines: NS user, NS provider, and NS user. The NS user initiates the process by sending an N-DATA request to the NS provider. The NS provider then sends an N-DATA indication to the NS user. + +NS user      NS provider      NS user + +N-DATA request + +N-DATA indication + +NSAP      NSAP + +T0817680-94/d26 + +Sequence diagram for network data transfer (N-DATA transfer). + +FIGURE A.9/T.70 +N-DATA transfer + +#### A.1.2.3 Network service error reporting + +![Sequence diagram for Network service error reporting (N-RESET).](5414f65867392f05ba0063b208eeb5e1_img.jpg) + +Sequence diagram illustrating Network service error reporting (N-RESET). The diagram shows three lifelines: NS user, NS provider, and NS user. The NS user sends an N-RESET indication to the NS provider. The NS provider then sends an N-RESET indication to the NS user. The diagram is labeled T0817690-94/d27. + +Sequence diagram for Network service error reporting (N-RESET). + +FIGURE A.10/T.70 +Network service error reporting + +#### A.1.2.4 Network connection release + +![Sequence diagram for Network connection release initiated by NS user (N-DISCONNECT).](744acfe8d4e31bcf03f95714c2f6e567_img.jpg) + +Sequence diagram illustrating Network connection release initiated by NS user (N-DISCONNECT). The diagram shows three lifelines: NS user, NS provider, and NS user. The NS user sends an N-DISCONNECT request to the NS provider. The NS provider then sends an N-DISCONNECT indication to the NS user. The diagram is labeled T0817700-94/d28. + +Sequence diagram for Network connection release initiated by NS user (N-DISCONNECT). + +FIGURE A.11/T.70 +NC release initiated by NS user + +![Sequence diagram for Network connection release initiated by NS provider (N-DISCONNECT).](6470d350326789d5306eabcb76533951_img.jpg) + +Sequence diagram illustrating Network connection release initiated by NS provider (N-DISCONNECT). The diagram shows three lifelines: NS user, NS provider, and NS user. The NS provider sends an N-DISCONNECT indication to the NS user. The NS user then sends an N-DISCONNECT request to the NS provider. The diagram is labeled T0817710-94/d29. + +Sequence diagram for Network connection release initiated by NS provider (N-DISCONNECT). + +FIGURE A.12/T.70 +NC release initiated by the NS provider + +## A.2 State transition diagrams for the basic transport layer procedures + +This part represents detailed state transition diagrams for the basic transport procedures. + +Two description levels are used: + +### a) *Protocol level* + +This level addresses only the peer to peer protocol activities between two transport entities. It identifies the protocol state, events [receipt of transport protocol data units (TPDUs)] and actions (sending of TPDUs). + +### b) *Detailed level* + +This level addresses the inter-layer and local activities. It identifies the events, actions, conditions and states within each of the protocol level states. The inter-layer activities are described using the transport service primitives defined in the first part of this annex. + +*Example* (see Figure A.13). + +For pure illustrative reasons, the example shows a simplified description of state 1 (response pending, called side) of the state transition diagram of this Recommendation. The event R-TCR may be answered either by sending the action S-TCA or S-TCC. + +The events and actions are not interruptable. They will complete their transfer irrespective of the occurrence of other events. + +The detailed state transition diagrams are given in Figures A.14 and A.15. + +![Figure A.13/T.70: State transition diagram for the basic transport layer procedures. The diagram shows a state transition for state 1 (response pending, called side). The state is represented by an oval labeled 'Wait'. Transitions are triggered by events (R-TCR, T-DISCONNECT request, T-CONNECT response) and result in actions (S-TCC, S-TCA, Stop timer, T-CONNECT indication).](ca5dc5fde2061d0ca2051ef7840fc842_img.jpg) + +Legend: + +- E → Event E +- S-TPDU → Send TPDU action +- R-TPDU → Receive TPDU event +- Ti → Timer associated with state i + +Diagram components: + +- State: Oval labeled 'Wait' +- Action: Rectangle labeled 'Stop timer', 'T-CONNECT indication', 'T-DISCONNECT request', 'T-CONNECT response' +- Protocol Level: Thick line +- Detailed Level: Thin line + +Transitions: + +- R-TCR (Event) → Stop timer (Action) +- Stop timer (Action) → T-CONNECT indication (Action) +- T-CONNECT indication (Action) → Wait (State) +- T-DISCONNECT request (Action) → S-TCC (Action) +- T-CONNECT response (Action) → S-TCA (Action) + +T0817720-94/d30 + +Figure A.13/T.70: State transition diagram for the basic transport layer procedures. The diagram shows a state transition for state 1 (response pending, called side). The state is represented by an oval labeled 'Wait'. Transitions are triggered by events (R-TCR, T-DISCONNECT request, T-CONNECT response) and result in actions (S-TCC, S-TCA, Stop timer, T-CONNECT indication). + +###### NOTES + +- 1 Each TPDU is transferred by N-DATA request. The NSDU will contain the TPDU. +- 2 Each TPDU is received by N-DATA indication. The NSDU will contain the TPDU. + +FIGURE A.13/T.70 + +![Teletex transport state transition diagram (calling side) showing states 0, 1, and 2 with various transitions and sub-diagrams for related states.](692541e65db4dc852988ce77ebb60ce5_img.jpg) + +The diagram illustrates the state transitions for the calling side of Teletex transport. It is organized into three main sections representing states 0, 1, and 2. + +- State 0 (Idle):** + - Initial state: 0.1 Idle. + - Transitions from 0.1: + - T-CONN req → 0.2 Wait + - N-DISC req → T-DISC ind + - N-DISC ind → T-DISC ind + - State 0.2 (Wait):** + - Transitions: N-CONN conf → T-DISC ind; N-DISC ind → Retry? + - Retry?** decision: + - Yes → 0.2 Wait + - No → 0.3 Wait<sup>1)</sup> + - 0.3 Wait<sup>1)</sup>: + - Transitions: T0.3 Timeout or N-RESET ind → N-DISC req; Discard → 0.3 Wait<sup>1)</sup>; R-any TPDU<sup>3)</sup> → 0.3 Wait<sup>1)</sup> + - N-DISC req → T-DISC ind + - State 1 (Wait<sup>1)</sup>):** + - Transitions: R-TCC → 1.1 Wait<sup>1)</sup>; S-TBR → 1.1 Wait<sup>1)</sup>; R-TCR → 1.1 Wait<sup>1)</sup> + - 1.1 Wait<sup>1)</sup>: + - Transitions: N-RESET ind or T1.1 timeout → 1.1 Wait<sup>1)</sup>; R-TBR or R-Invalid TPDU other than TCR → 1.1 Wait<sup>1)</sup> + - State 2 (Wait):** + - Transitions: R-TCA → 2.1 Wait; T-CONN conf → 2.1 Wait + - 2.1 Wait:** + - Transitions: T-EXCEPTION ind → 2.1 Wait; N-RESET ind<sup>5)</sup> → 2.1 Wait; T-EXCEPTION ind<sup>4)</sup> → 2.1 Wait + - Reassembly (EM = 0)?** decision: + - Yes → 2.1 Wait + - No → T-DATA ind + - T-DATA ind → T-DATA req or TSDU part(s) outstanding + - Segmentation?** decision: + - Yes → EM = 0 + - No → EM = 1 + - EM = 0 → S-TDT + - EM = 1 → S-TDT + - S-TDT → 2.1 Wait + - R-TDT → 2.1 Wait + - R-TBR<sup>4)</sup> → 2.1 Wait + - R-Invalid TPDU<sup>4)</sup> → 2.1 Wait + +Sub-diagrams and external inputs: + + - States 1.1, 2.1:** N-DISC ind → T-DISC ind + - States 0.2, 0.3, 1.1, 2.1:** T-DISC req → T-DISC ind + - State 2.1:** N-RESET ind → T-DISC ind + +T0817730-94/d31 + +Teletex transport state transition diagram (calling side) showing states 0, 1, and 2 with various transitions and sub-diagrams for related states. + +- 1) States 0.3 and 1.1 have timers, T0.3 and T1.1 respectively. When entering any of these states the associated timer is started. The timer is stopped upon exit from the state [see <sup>3)</sup>]. +- 2) There are other valid methods for describing segmentation. +- 3) This state transition does not start/stop T0.3 timer. +- 4) Optional transition (shown in broken lines) if "T-EXCEPTION ind" is provided. +- 5) Optional transition (shown in broken lines) if "T-EXCEPTION ind" is provided. The use of this option is independent of the use of option <sup>4)</sup> above. + +FIGURE A.14/T.70 +Teletex transport state transition diagram (calling side) + +![Teletex transport transition diagram (called side)](08dce7ad4c512fdf0c0cde60415fade6_img.jpg) + +``` + + graph TD + %% State 0 + S0((0 0.1 Idle)) -->|N-CONN ind| D1{CONN acceptable?} + D1 -->|No| S0 + D1 -->|Yes| S02((0.2 Wait1))) + S02 -->|N-CONN resp| S1((1)) + + %% State 1 + S1 -->|R-TCR| D2{Acceptable?} + D2 -->|No| S1 + D2 -->|Yes| S11((1.1 Wait)) + S11 -->|T-CONN ind| S11 + S11 -->|T-CONN resp| S2((2)) + + %% State 2 + S2 -->|S-TCA| S21((2.1 Wait)) + S21 -->|T-DATA req or TSDU part(s) outstanding| D3{Segmentation?} + D3 -->|Yes| S21 + D3 -->|No| S21 + + %% Global Transitions and Disconnects + AnyState((Any state except 0.1, 0.2, 1.1)) -->|T-DISC req| S0 + S11 -->|T-DISC req| S0 + S03((0.3 Wait1))) -->|T0.3 timeout or N-RESET ind| S0 + +``` + +Detailed description: The diagram shows the state transitions for the called side of a Teletex transport connection. It starts at state 0.1 (Idle). Upon receiving an N-CONN indication, it checks if the connection is acceptable. If yes, it moves to state 0.2 (Wait) and then to state 1 after an N-CONN response. In state 1, it waits for a TCR. If acceptable, it moves to state 1.1 (Wait) and then to state 2 after a T-CONN response. State 2 involves data transfer (S-TCA, S-TDT, R-TDT) and handles segmentation. Various disconnect (T-DISC, N-DISC) and reset (N-RESET) signals can trigger transitions back to the Idle state or intermediate wait states. Broken lines indicate optional transitions related to T-EXCEPTION indications. + +Teletex transport transition diagram (called side) + +- States 0.2 and 0.3 have timers, T0.2 and T0.3 respectively. When entering any of these states the asssociated timer is started. The timer is stopped upon exit from the state [see<sup>3)</sup>]. +- There are other valid methods for describing segmentation. +- This state transition does not start/stop T0.3 timer. +- Optional transition (shown in broken lines) if “T-EXCEPTION ind” is provided. +- Optional transition (shown in broken lines) if “T-EXCEPTION ind” is provided. The use of this option is independent of the use of option <sup>4)</sup> above. + +FIGURE A.15/T.70 +**Teletex transport transition diagram (called side)** + +**Recommendation T.70 (03/93)**      29 + +# Annex B + +(This annex forms an integral part of this Recommendation) + +## B.1 State tables + +The state tables: + +B.1: Transport connection establishment, calling side + +B.2: Transport connection establishment, called side + +B.3: Data phase (symmetrical protocol) + +present the transitions of the transport protocol in a table form in contrast to the diagram form to be seen in Annex A. While the diagrams are useful to overview the protocol mechanism the appropriate tables give clear information of which event is possible in which state and which actions are to be performed. Moreover each of the events and conditions is combined with a shortening in brackets (e.g.: E 5) which is a pointer to the 2nd part of this annex, so that the reader of these tables can easily come to know which meaning a certain event, action or condition has. + +An impossible event related to a certain state can be recognized by an empty field in the crossing-point of the state and the event. + +## B.2 Lists of events, actions and conditions + +The lists of events (Table B.4), actions (Table B.5) and conditions (Table B.6) intend to care for detailed explanations and clarification related to the protocol components (events, actions and conditions) found in the diagrams and tables. + +All the components in the tables are accompanied by a list number (e.g. E 1, A 10, C 3, etc.) which can be interpreted as a pointer to the corresponding additional information in the lists. The letters E, A, C of the list numbers stand for Event, Action, Condition. + +The following abbreviations are used: + +| | | +|------|---------------------------------------------------| +| EM | End Mark | +| LI | Length Indicator of the transport block (octet 1) | +| loc. | local | +| NC | Network Connection | +| NS | Network Service | +| NSDU | Network Service Data Unit | +| PLI | Parameter Length Indicator | +| TC | Transport Connection | +| TP | Transport Protocol | +| TPDU | Transport Protocol Data Unit | +| TS | Transport Service | +| TSDU | Transport Service Data Unit | + +AND, OR and NOT (used mainly in E 5) shall be considered as the known Boolean operators. + +TABLE B.1/T.70 + +### State table for calling side + +| State | | | | Idle | | | | | | | | | | | | Waiting | | | | +|-------|-------|-------------------------------|-------------------|-------|-----------------|-------------------|-------------|-------|-----------------|-------------------|-------------|-------|---------------------------|-------------------|-------------|-------------------------------------|-----------------|--------------------------------------|-------------| +| Event | | | | 0.1 | | | | 0.2 | | | | 0.3 | | | | 1.1 | | | | +| No. | Local | Protocol event | Service primitive | Local | Protocol action | Service primitive | Final state | Local | Protocol action | Service primitive | Final state | Local | Protocol action | Service primitive | Final state | Local | Protocol action | Service primitive | Final state | +| 1.1 | | R-TCR (E 1) | | | | | | | | | | | Discard any R-TPDU (A 14) | | 0.3 | STOP T1.1 (A 1)<br>START T0.3 (A 2) | S-TBR (A 3) | | 0.3 | +| 1.2 | | R-TCC (E 2)<br>Retry (C 1) | | | | | | | | | | | | | 0.3 | RESTART T1.1 (A 6) | S-TCR (A 7) | | 1.1 | +| 1.3 | | R-TCC (E 2)<br>No retry (C 2) | | | | | | | | | | | | | 0.3 | STOP T1.1 (A 1) | | N-DISC req (A 4)<br>T-DISC ind (A 5) | 0.1 | +| 1.4 | | R-TCA (E 3) | | | | | | | | | | | | | 0.3 | STOP T1.1 (A 1) | | T-CONN conf (A 8) | 2.1 | +| 1.5 | | R-TBR (E 4) | | | | | | | | | | | | | 0.3 | STOP T1.1 (A 1) | | T-DISC ind (A 5)<br>N-DISC req (A 4) | 0.1 | +| 1.6 | | R-invalid TPDU (E 5) | | | | | | | | | | | | | 0.3 | STOP T1.1 (A 1) | | T-DISC ind (A 5)<br>N-DISC req (A 4) | 0.1 | + +TABLE B.1/T.70 (end) + +### State table for calling side + +| State | | | | Idle | | | | | | | | | | | | Waiting | | | | +|-------|-----------------|----------------|-------------------|-------|-----------------|-------------------|-------------|-------------------|-----------------|-------------------|-------------|------------------|-----------------|----------------------------------------|-------------|-----------------|-----------------|----------------------------------------|-------------| +| Event | | | | 0.1 | | | | 0.2 | | | | 0.3 | | | | 1.1 | | | | +| No. | Local | Protocol event | Service primitive | Local | Protocol action | Service primitive | Final state | Local | Protocol action | Service primitive | Final state | Local | Protocol action | Service primitive | Final state | Local | Protocol action | Service primitive | Final state | +| 1.7 | | | T-CONN req (E 6) | | | T-CONN req (A 10) | 0.2 | | | | | | | | | | | | | +| 1.8 | | | N-CONN conf (E 7) | | | | | START T1.1 (A 12) | S-TCR (A 7) | | 1.1 | | | | | | | | | +| 1.9 | | | N-DISC ind (E 8) | | | | | | | T-DISC ind (A 5) | 0.1 | STOP T0.3 (A 13) | | T-DISC ind. (A 5) | 0.1 | STOP T1.1 (A 1) | | T-DISC ind. (A 5) | 0.1 | +| 1.10 | | | N-RESET ind (E 9) | | | | | | | | | STOP T0.3 (A 13) | | N-DISC req. (A 4)<br>T-DISC ind. (A 5) | 0.1 | STOP T1.1 (A 1) | | T-DISC ind. (A 5)<br>N-DISC req. (A 4) | 0.1 | +| 1.11 | | | T-DISC req (E 10) | | | | | | | N-DISC req (A 4) | 0.1 | STOP T0.3 (A 13) | | N-DISC req. (A 4) | 0.1 | STOP T1.1 (A 1) | | N-DISC req. (A 4) | 0.1 | +| 1.12 | TIME OUT (E 11) | | | | | | | | | | | STOP T0.3 (A 13) | | N-DISC req. (A 4)<br>T-DISC ind. (A 5) | 0.1 | STOP T1.1 (A 1) | | T-DISC ind. (A 5)<br>N-DISC req. (A 4) | 0.1 | +| Req | Request | | | CONN | CONNECTION | | | | | | | | | | | | | | | +| Ind | Indication | | | DISC | DISCONNECTION | | | | | | | | | | | | | | | +| Conf | Confirmation | | | | | | | | | | | | | | | | | | | + +TABLE B.2/T.70 +State table for called side + +| State | | | | Idle | | | | | | | | | | | | Waiting | | | | +|-------|-------|-------------------------------------|-------------------------------------------|------------------|-----------------|--------------------|-------------|---------------------|------------------|-------------------|-------------|------------------|---------------------------|-------------------|-------------|------------------|-----------------|-------------------|-------------| +| Event | | | | 0.1 | | | | 0.2 | | | | 0.3 | | | | 1.1 | | | | +| No. | Local | Protocol event | Service primitive | Local | Protocol action | Service primitive | Final state | Local | Protocol action | Service primitive | Final state | Local | Protocol action | Service primitive | Final state | Local | Protocol action | Service primitive | Final state | +| 2.1 | | R-TCR (E 1)<br>Acceptable (C 3) | | | | | | STOP T0.2 (A 11) | | T-CONN ind (A 15) | 1.1 | | Discard any R-TPDU (A 14) | | 0.3 | | | | | +| 2.2 | | R-TCR (E 1)<br>Not acceptable (C 4) | | | | | | RESTART T0.2 (A 16) | S-TCC (A 17) | | 0.2 | | | | 0.3 | | | | | +| 2.3 | | R-invalid TPDU (E 5) | | | | | | STOP T0.2 (A 11) | N-DISC req (A 4) | | 0.1 | | | | 0.3 | START T0.3 (A 2) | S-TBR (A 3) | | 0.3 | +| 2.4 | | | N-CONN ind (E 12)<br>Acceptable (C 5) | START T0.2 (A 9) | | N-CONN resp (A 22) | 0.2 | | | | | | | | | | | | | +| 2.5 | | | N-CONN ind (E 12)<br>Not acceptable (C 6) | | | N-DISC req (A 4) | 0.1 | | | | | | | | | | | | | +| 2.6 | | | T-CONN resp (E 13) | | | | | | | | | | | | | | S-TCA (A 24) | | 2.1 | +| 2.7 | | | N-DISC ind (E 8) | | | | | STOP T0.2 (A 11) | | | 0.1 | STOP T0.3 (A 13) | | T-DISC ind (A 5) | 0.1 | | | T-DISC ind (A 5) | 0.1 | + +TABLE B.2/T.70 (*end*) + +### **State table for called side** + +| State | | | | Idle | | | | | | | | | | | | Waiting | | | | +|-------|-----------------|----------------|-------------------|-------|-----------------|-------------------|-------------|------------------|-----------------|-------------------|-------------|------------------|-----------------|----------------------------------------|-------------|------------------|-----------------|--------------------------------------|-------------| +| Event | | | | 0.1 | | | | 0.2 | | | | 0.3 | | | | 1.1 | | | | +| No. | Local | Protocol event | Service primitive | Local | Protocol action | Service primitive | Final state | Local | Protocol action | Service primitive | Final state | Local | Protocol action | Service primitive | Final state | Local | Protocol action | Service primitive | Final state | +| 2.8 | | | N-RESET ind (E 9) | | | | | STOP T0.2 (A 11) | | N-DISC req (A 4) | 0.1 | STOP T0.3 (A 13) | | T-DISC ind (A 5)<br>N-DISC req (A 4) | 0.1 | | | T-DISC ind (A 5)<br>N-DISC req (A 4) | 0.1 | +| 2.9 | | | T-DISC req (E 10) | | | | | | | | | STOP T0.3 (A 13) | | N-DISC req (A 4) | 0.1 | START T0.2 (A 9) | S-TCC (A 17) | | 0.2 | +| 2.10 | TIME OUT (E 11) | | | | | | | STOP T0.2 (A 11) | | N-DISC req (A 4) | 0.1 | STOP T0.3 (A 13) | | T-DISC ind. (A 5)<br>N-DISC req. (A 4) | 0.1 | | | | | +| Req | Request | | | CONN | CONNECTION | | | | | | | | | | | | | | | +| Ind | Indication | | | DISC | DISCONNECTION | | | | | | | | | | | | | | | +| Resp | Response | | | | | | | | | | | | | | | | | | | + +TABLE B.3/T.70 + +### **Data phase (symmetrical protocol)** + +| | State | | | Data phase | | | | +|---------|--------------------|--------------------------------------------|-----------------------------------------|----------------------------|-----------------------|--------------------------------------|-------------| +| | Event | | | 2.1 | | | | +| | Local | Protocol event | Service primitive | Local | Protocol action | Service primitive | Final state | +| 3.1 | | R-TDT (E 14)<br>EM = 0 (C 7) | | | | | 2.1 | +| 3.2 | | R-TDT (E 14)<br>EM = 1 (C 8) | | | | T-DATA ind (A 18) | 2.1 | +| 3.3 | | R-TBR (E 4)<br>Recovery (C 9) | | | | T-EXCEPT ind (A 19) | 2.1 | +| 3.4 | | R-TBR (E 4)<br>No recovery (C 10) | | | | T-DISC ind (A 5)<br>N-DISC req (A 4) | 0.1 | +| 3.5 | | R-invalid TPDU (E 5)<br>Recovery (C 9) | | | S-TBR (A 3) | T-EXCEPT (A 19) | 2.1 | +| 3.6 | | R-invalid TPDU (E 5)<br>No recovery (C 10) | | START T0.3 (A 2) | S-TBR (A 3) | | 0.3 | +| 3.7 | | | T-DATA req (E 15)<br>Segm. (C 11) | | S-TDT (EM = 0) (A 20) | | 2.1 | +| 3.8 | | | T-DATA req (E 15)<br>No segm. (C 12) | | S-TDT (EM = 1) (A 21) | | 2.1 | +| 3.9 | TSDU part(s) | Segm. (C 11) | | | S-TDT (EM = 0) (A 20) | | 2.1 | +| 3.10 | outsand (E 16) | No segm. (C 12) | | | S-TDT (EM = 1) (A 21) | | 2.1 | +| 3.11 | | | N-RESET ind (E 9)<br>Recovery (C 9) | | | T-EXCEPT ind (A 19) | 2.1 | +| 3.12 | | | N-RESET ind (E 9)<br>No recovery (C 10) | | | T-DISC ind (A 5)<br>N-DISC req (A 4) | 0.1 | +| 3.13 | | | N-DISC ind (E 8) | | | T-DISC ind (A 5) | 0.1 | +| 3.14 | | | T-DISC ind (E 10) | | | N-DISC ind (A 4) | 0.1 | +| Ind Req | Indication Request | | DISC<br>EXCEPT | DISCONNECTION<br>EXCEPTION | | | | + +TABLE B.4/T.70 + +### List of events + +| No. | Name | Type | Description | +|-----|----------------|------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| E 1 | R-TCR | TP | Layer 4 receives via the NS N-DATA indication a TPDU including the transport block TCR. | +| E 2 | R-TCC | TP | Layer 4 receives via the NS N-DATA indication a TPDU including the transport block TCC. | +| E 3 | R-TCA | TP | Layer 4 receives via the NS N-DATA indication a TPDU including the transport block TCA. | +| E 4 | R-TBR | TP | Layer 4 receives via the NS N-DATA indication a TPDU including the transport block TBR. | +| E 5 | R-invalid TPDU | TP | <p>Layer 4 receives via the NS N-DATA indication a TPDU whose validity check fails due to the following reasons:</p> <ul style="list-style-type: none"> <li>– syntactical errors</li> <li>– procedure errors</li> </ul> <ol style="list-style-type: none"> <li>1. <i>Invalid TPDUs due to syntactical errors</i> <ol style="list-style-type: none"> <li>1.1 TCR: <ol style="list-style-type: none"> <li>1.1.1 The value of octet 1 (LI): <ol style="list-style-type: none"> <li>1.1.1.1 <math>\neq</math> the number of the TCR block octets minus 1 OR</li> <li>1.1.1.2 is greater than 127 OR</li> <li>1.1.1.3 is smaller than 6 OR</li> </ol></li> <li>1.1.2 see 1.6</li> </ol></li> <li>1.2 TCA: <ol style="list-style-type: none"> <li>1.2.1 The value of octet 1 (LI): <ol style="list-style-type: none"> <li>1.2.1.1 <math>\neq</math> the number of the TCA block octets minus 1 OR</li> <li>1.2.1.2 is greater than 127 OR</li> <li>1.2.1.3 is smaller than 6 OR</li> </ol></li> <li>1.2.2 see 1.6 OR</li> <li>1.2.3 The value of octet 3 (4 resp.) <math>\neq</math> octet 5 (6 resp.) of the appropriate TCR block OR</li> <li>1.2.4 The value of octet 7 <math>\neq</math> 0 OR</li> <li>1.2.5 The parameter ‐Transport Data Block Size‑ is present: <ol style="list-style-type: none"> <li>1.2.5.1 AND its value <math>\neq</math> 07 (hexadecimal), in response to a TCR block without the transport data block size parameter OR</li> <li>1.2.5.2 AND its value does not respond to the rules according to subclause 5.2.3.2 OR</li> <li>1.2.5.3 AND its value is different from the values (hexadecimal): 07, 08, 09, 0A, 0B OR</li> <li>1.2.5.4 AND the PLI > 1 OR</li> </ol></li> <li>1.2.6 <math>LI \neq 6 + 2N + \sum_{i=1}^{N} PLI</math><br/>where N is the number of parameters</li> </ol></li> <li>1.3 TCC: <ol style="list-style-type: none"> <li>1.3.1 The value of the LI (octet 1): <ol style="list-style-type: none"> <li>1.3.1.1 <math>\neq</math> the number of the TCC block octets minus 1 OR</li> <li>1.3.1.2 is greater than 127 OR</li> <li>1.3.1.3 is smaller than 6 OR</li> </ol></li> <li>1.3.2 see 1.6 OR</li> <li>1.3.3 The value of octet 3 (4 resp.) <math>\neq</math> octet 5 (6 resp.) of the appropriate TCR block OR</li> <li>1.3.4 <math>LI \neq 6 + 2N + \sum_{i=1}^{N} PLI</math><br/>where N is the number of parameters</li> </ol></li> <li>1.4 TBR: (also see subclause 5.4.1, Note 1) <ol style="list-style-type: none"> <li>1.4.1 The value of the LI: <ol style="list-style-type: none"> <li>1.4.1.1 <math>\neq</math> the number of the TBR block octets minus 1 OR</li> <li>1.4.1.2 is greater than 127 OR</li> <li>1.4.1.3 is smaller than 7 OR</li> </ol></li> <li>1.4.2 see 1.6 OR</li> </ol></li> </ol></li> </ol> | + +TABLE B.4/T.70 (continued) + +### List of events + +| No. | Name | Type | Description | | | | | | | | | | | | | | | | +|--------|-------------------------|-----------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--|--------|--|--------|--------------|-------------|-----|----------------|-----------------|-----|---------------|---------------|-----|-----------------|----------------| +| E 5 | R-invalid TPDU | TP | <p>1.4.3 The value of octet 3 (4 resp.) <math>\neq</math> octet 5 (6 resp.) of the appropriate TC establishment block (TCR resp. TCA) received from the peer entity OR</p> <p>1.4.4 The value of LI minus 6 <math>\neq</math> value of the PLI OR</p> <p>1.4.5 The Rejected block parameter is not present</p> <p>1.5 TDT:</p> <p>1.5.1 The value of the LI <math>\neq</math> 2 OR</p> <p>1.5.2 The TSDU end mark is 0 AND the information field is empty OR</p> <p>1.5.3 The TDT block size is larger than negotiated in the establishment phase</p> <p>1.6 No identified block:<br/>The value of the TPDU octet 2 is not equal to one of the following values (hexadecimal): EX, DO, 80, 70, FO.<br/>X may be in the range of <math>0 \leq X \leq F</math></p> <p>2. Invalid TPDUs due to procedure errors</p> <p>Failure cases:</p> <p>2.1 After S-TCR:</p> <p>2.1.1 NOT R-TCA OR</p> <p>2.1.2 NOT R-TCC OR</p> <p>2.1.3 NOT R-TBR OR</p> <p>2.2 After S-TCA:</p> <p>2.2.1 NOT R-TDT OR</p> <p>2.2.2 NOT R-TBR OR</p> <p>2.3 After S-TDT:</p> <p>2.3.1 Not R-TDT OR</p> <p>2.3.2 Not R-TBR OR</p> <p>2.4 After S-TCC: NOT R-TCR OR</p> <p>2.5 After S-TBR: NOT R-TDT (in state 2.1) OR</p> <p>2.6 After R-TDT (EM = 1): R-empty TDT (EM = 1) OR</p> <p>2.7 After R-empty (EM = 1): R-empty TDT (EM = 1) OR</p> <p>2.8 After N-CONNECT response: NOT R-TCR</p> | | | | | | | | | | | | | | | | +| E 6 | T-CONNECT request | TS | Layer 5 requests a TC from layer 4. | | | | | | | | | | | | | | | | +| E 7 | N-CONNECT confirm | NS | Affirmative answer to N-CONNECT request (A 10); an NC is existing now. | | | | | | | | | | | | | | | | +| E 8 | N-DISCONNECT indication | NS | Report from layer 3 to layer 4 that the NC is not existing (any more). | | | | | | | | | | | | | | | | +| E 9 | N-RESET indication | NS | Indication to layer 4 that an error has occurred in layer 1, 2 or 3, possibly with data loss. The NC is kept existing. | | | | | | | | | | | | | | | | +| E 10 | T-DISCONNECT request | TS | Layer 5 requests a TC clearing from layer 4. | | | | | | | | | | | | | | | | +| E 11 | TIMEOUT | loc. | <p>The timer presently surveying a state reached its limit. Following value ranges are defined:</p> <table border="1" data-bbox="662 1563 1394 1845"> <thead> <tr> <th></th> <th colspan="2">Values</th> </tr> <tr> <th>States</th> <th>Calling side</th> <th>Called side</th> </tr> </thead> <tbody> <tr> <td>0.2</td> <td>Not applicable</td> <td>45 s <math>\pm</math> 30 s</td> </tr> <tr> <td>0.3</td> <td>6 s <math>\pm</math> 4 s</td> <td>6 s <math>\pm</math> 4 s</td> </tr> <tr> <td>1.1</td> <td>45 s <math>\pm</math> 30 s</td> <td>Not applicable</td> </tr> </tbody> </table> | | Values | | States | Calling side | Called side | 0.2 | Not applicable | 45 s $\pm$ 30 s | 0.3 | 6 s $\pm$ 4 s | 6 s $\pm$ 4 s | 1.1 | 45 s $\pm$ 30 s | Not applicable | +| | Values | | | | | | | | | | | | | | | | | | +| States | Calling side | Called side | | | | | | | | | | | | | | | | | +| 0.2 | Not applicable | 45 s $\pm$ 30 s | | | | | | | | | | | | | | | | | +| 0.3 | 6 s $\pm$ 4 s | 6 s $\pm$ 4 s | | | | | | | | | | | | | | | | | +| 1.1 | 45 s $\pm$ 30 s | Not applicable | | | | | | | | | | | | | | | | | + +TABLE B.4/T.70 (*end*) + +### **List of events** + +| No. | Name | Type | Description | +|------|--------------------------|------|------------------------------------------------------------------------------------------------------------------------------------------------------| +| E 12 | N-CONNECT indication | NS | Indication to layer 4 by the layer 3 that an NC is being established; the answer to this is N-CONNECT response (A 22) or N-DISCONNECT request (A 4). | +| E 13 | T-CONNECT response | TS | Affirmative answer by the layer 5 to T-CONNECT indication (A 15). | +| E 14 | R-TDT | TP | Layer 4 receives via the NS N-DATA indication, an NSDU including the transport block TDT. | +| E 15 | T-DATA request | TS | Layer 5 requests the transmission of data. Whether this is a complete TSDU or not, is a local matter, and not subject of this definition. | +| E 16 | TSDU part(s) outstanding | loc. | Layer 4 is ready to send the next TDT block. | + +TABLE B.5/T.70 + +### **List of actions** + +| No. | Name | Type | Description | +|------|-------------------------|------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| A 1 | STOP Timer T1.1 | loc. | Timer T1.1 surveying the state 1.1 is stopped. | +| A 2 | START Timer T0.3 | loc. | Timer T0.3 surveying the state 0.3 is started after having been reset. | +| A 3 | S-TBR | TP | Via the NS N-DATA request an NSDU including the transport block TBR is sent to the peer entity. | +| A 4 | N-DISCONNECT request | NS | Layer 4 requests the layer 3 to release the offered or existing NC. | +| A 5 | T-DISCONNECT indication | TS | Layer 5 is informed by the layer 4 that the TC being established or existing is cleared. | +| A 6 | RESTART T1.1 | loc. | Timer T1.1 surveying the state 1.1 is reset and started again. Moreover, it is necessary either to limit the number of T1.1-restarts or to limit the sum of all the times of T1.1; otherwise, an infinite loop S-TCR – R-TCC – S-TCR – etc., would be allowed. | +| A 7 | S-TCR | TP | Via the NS N-DATA request an NSDU including the transport block TCR is sent to the peer entity. | +| A 8 | T-CONNECT confirm | TS | Affirmative answer to the event T-CONNECT request (E 6) indicating that the data phase of the TC has been entered. | +| A 9 | START T0.2 | loc. | Timer T0.2 surveying the state 0.2 is started after having been reset. | +| A 10 | N-CONNECT request | NS | Layer 4 requests the layer 3 for an NC to be established. | +| A 11 | STOP T0.2 | loc. | Timer T0.2 surveying the state 0.2 is stopped. | +| A 12 | START T1.1 | loc. | Timer T1.1 surveying the state 1.1 is started after having been reset. | +| A 13 | STOP T0.3 | loc. | Timer T0.3 surveying the state 0.3 is stopped. | +| A 14 | DISCARD any R-TPDU | TS | Any data received by N-DATA indication are discarded. The transmission of further data is stopped. | +| A 15 | T-CONNECT indication | TS | Layer 4 indicates a request for a TC-establishment to the layer 5. | +| A 16 | RESTART T0.2 | loc. | Timer T0.2 surveying the state 0.2 is reset and started again. | +| A 17 | S-TCC | TP | Via the NS N-DATA request, an NSDU including the transport block TCC is sent to the peer entity. | +| A 18 | T-DATA indication | TS | Layer 4 indicates the receipt of a complete TSDU to the layer 5. How and when the contents are transferred is a local matter, and therefore, not shown here. | +| A 19 | T-EXCEPTION indication | TS | Layer 5 is informed of an error which occurred between the layer 1 and layer 4, possibly with data loss; the TC is kept existing. Due to this error it is possible that the following TSDU transferred to the layer 5 contains errors or deficiencies. | +| A 20 | S-TDT (EM = 0) | TP | A TPDU with TSDU end mark set to 0 is sent to the peer entity and further parts of the TSDU will follow (i.e. segmenting occurs). | +| A 21 | S-TDT (EM = 1) | TP | See A 20, but the TSDU end mark is set to 1 (i.e. this TPDU contains a complete TSDU or the last part of a TSDU). | +| A 22 | N-CONNECT response | NS | Affirmative answer to N-CONNECT indication (E 12). | +| A 23 | S-TBR | TP | The called side sends a TBR block to the calling side in order to point to a received failure TPDU. In this case the destination reference can be set to 0. | +| A 24 | S-TCA | TP | Via the NS N-DATA request an NSDU including the transport block TCA is sent to the peer entity. | + +TABLE B.6/T.70 + +### **List of conditions** + +| No. | Name | Description | +|------|-------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| C 1 | Retry | The TC establishment is tried once more. | +| C 2 | No retry | NOT C 1 | +| C 3 | TC acceptable | The TC offered by the peer entity is accepted by the layer 4 due to local circumstances. | +| C 4 | TC not acceptable | NOT C 3 | +| C 5 | NC acceptable | The NC offered by the layer 3 is accepted by the layer 4 due to local circumstances. | +| C 6 | NC not acceptable | NOT C 5 | +| C 7 | EM = 0 | TSDU end mark of the TDT block is 0 | +| C 8 | EM = 1 | TSDU end mark of the TDT block is 1 | +| C 9 | Recovery | The terminal provides the TS T-EXCEPTION indication | +| C 10 | No recovery | NOT C 9 | +| C 11 | Segmentation | The TSDU received from layer 5 is longer than the negotiated TDT block size and has, therefore, to be segmented and consequently, to be reassembled on the receiver side. | +| C 12 | No segmentation | NOT C 11 | + +# **Annex C** + +# **Recommendations for implementation of Recommendation X.21** + +(This annex forms an integral part of this Recommendation) + +## **C.1 General** + +This Annex deals with recommended actions to be taken by a telematic DTE in relation to the receipt of call progress (CP) signals from the network and in relation to the handling of optional user facilities. The adherence to these recommendations is not mandatory in order to conform to this Recommendation but may be of importance for the performance of the DTE. + +Telematic terminals are in general assumed to make automatic repeated call attempts and sequential automatic calls to a number of addresses for which the following actions apply. + +## **C.2 Receipt of call progress signals 01 or 04** + +When one of the CPS 01 or 04 is received the DTE should use the timer T3B and wait up to 60s for the completion of the call. + +## **C.3 Receipt of call progress signal 03** + +The DTE should use either timer T3A or T3B in this case, depending on the time the DTE is prepared to wait for the completion of the call. Observe that the queuing time is charged as communication time in some networks. + +## C.4 Receipt of call progress signals of the group 2 to 8 + +See Table C.1. + +NOTE – Some networks charge for call attempts, when the call is unsuccessful due to the condition of the called DTE. Examples of such situations are the receipt of the call progress signals 21 (busy) and 45 (controlled not ready). + +TABLE C.1/T.70 + +| Code group/Code | Delay for reattempts (s) | Number of reattempts | Delay between series of reattempts (s) | +|-------------------------|--------------------------|----------------------|----------------------------------------| +| 2, 6 | $\geq 5$ | $\leq 7$ | $\geq 60$ | +| 41, 42, 43, 48<br>5, 8 | $\geq 5$ | $\leq 1$ | Retattempts are not recommended | +| 44, 45, 46, 47, 49<br>7 | $\geq 5$ | $\leq 1$ | $\geq 600$ | + +# Annex D + +## Service definitions and state transition diagrams for the HDLC procedure and the network layer defined for CSPDN + +(This annex forms an integral part of this Recommendation) + +## D.1 Service definitions + +### D.1.1 Physical service used by HDLC + +See Figure D.1. + +![Sequence diagram for PH-data-transfer showing the flow from PHS user to PHS provider and then to PHS user.](822e033872d5ab16e861571f47b81ba7_img.jpg) + +``` +sequenceDiagram + participant PHS_user1 as PHS user + participant PHS_provider as PHS provider + participant PHS_user2 as PHS user + PHS_user1->>PHS_provider: PH-DATA request + PHS_provider->>PHS_user2: PH-DATA indication + Note over PHS_provider: T0817750-94/d33 +``` + +The diagram illustrates the PH-data-transfer process. It shows three entities: PHS user, PHS provider, and PHS user. A PHS user sends a PH-DATA request to the PHS provider. The PHS provider then sends a PH-DATA indication to another PHS user. The PHS provider is also associated with the reference T0817750-94/d33. + +Sequence diagram for PH-data-transfer showing the flow from PHS user to PHS provider and then to PHS user. + +FIGURE D.1/T.70 +PH-data-transfer + +### D.1.2 Data link service (HDLC) + +#### D.1.2.1 Data link connection establishment + +See Figures D.2 and D.3. + +![Sequence diagram for Successful DLC-establishment showing interactions between DLS user and DLS provider.](0a42e05c07941450f34e4f7117725834_img.jpg) + +``` + +sequenceDiagram + participant DLS_user1 as DLS user + participant DLS_provider as DLS provider + participant DLS_user2 as DLS user + + DLS_user1->>DLS_provider: DL-ACTIVATE request + DLS_provider-->>DLS_user1: DL-ACTIVATE confirm + DLS_user1->>DLS_provider: DL-CONNECT request + DLS_provider->>DLS_user2: DL-CONNECT indication + DLS_provider->>DLS_user1: UA + DLS_provider->>DLS_provider: SABM + DLS_user1-->>DLS_provider: DL-CONNECT confirm + +``` + +T0817760-94/d34 + +DLSAP DLSAP + +Sequence diagram for Successful DLC-establishment showing interactions between DLS user and DLS provider. + +FIGURE D.2/T.70 +Successful DLC-establishment + +![Sequence diagram for Not successful DLC-establishment showing interactions between DLS user and DLS provider.](e22af684d8e56d4c61e61bb5ddac1087_img.jpg) + +``` + +sequenceDiagram + participant DLS_user1 as DLS user + participant DLS_provider as DLS provider + participant DLS_user2 as DLS user + + DLS_user1->>DLS_provider: DL-ACTIVATE request + DLS_provider-->>DLS_user1: DL-ACTIVATE confirm + DLS_user1->>DLS_provider: DL-CONNECT request + DLS_provider->>DLS_user2: DL-CONNECT indication + DLS_provider->>DLS_user1: SABM + DLS_provider->>DLS_provider: SABM N2 times + DLS_user1-->>DLS_provider: DL-DISCONNECT indication + +``` + +T0817770-94/d35 + +DLSAP DLSAP + +Sequence diagram for Not successful DLC-establishment showing interactions between DLS user and DLS provider. + +FIGURE D.3/T.70 +Not successful DLC-establishment + +#### D.1.2.2 Data link transfer phase + +See Figure D.4. + +![Sequence diagram for DL-data transfer showing interactions between DLS user and DLS provider.](c1278da91cbcabe32628e589ebc47418_img.jpg) + +``` + +sequenceDiagram + participant DLS_user1 as DLS user + participant DLS_provider as DLS provider + participant DLS_user2 as DLS user + + DLS_user1->>DLS_provider: DL-DATA request + DLS_provider->>DLS_user2: DL-DATA indication + DLS_provider->>DLS_user1: I-Frame + +``` + +T0817780-94/d36 + +DLSAP DLSAP + +Sequence diagram for DL-data transfer showing interactions between DLS user and DLS provider. + +FIGURE D.4/T.70 +DL-data transfer + +#### D.1.2.3 Data link release + +See Figures D.5 and D.6. + +![Sequence diagram for DL-release initiated by DL-user (Figure D.5/T.70).](41aef1f5efab13d4f38f69e86c726062_img.jpg) + +This sequence diagram illustrates the process of data link release initiated by a DL-user. It involves three entities: DLS user (left), DLS provider (center), and DLS user (right). The diagram shows the following sequence of messages: + +- The left DLS user sends a **DL-DISCONNECT request** to the DLS provider. +- The DLS provider sends a **DISC** message to the right DLS user. +- The right DLS user sends a **DL-DISCONNECT indication** to the DLS provider. +- The DLS provider sends a **UA** message to the left DLS user. +- The left DLS user sends a **DL-DISCONNECT confirm** to the DLS provider. +- The left DLS user sends a **DL-DEACTIVATE request** to the DLS provider. +- The right DLS user sends a **DL-DEACTIVATE request** to the DLS provider. +- The right DLS user sends a **DL-DEACTIVATE confirm** to the DLS provider. +- The left DLS user sends a **DL-DEACTIVATE confirm** to the DLS provider. + +The diagram is labeled with **DLSAP** at the bottom of each vertical line and includes the reference **T0817790-94/d37** at the bottom right. + +Sequence diagram for DL-release initiated by DL-user (Figure D.5/T.70). + +FIGURE D.5/T.70 +DL-release initiated by DL-user + +![Sequence diagram for DL-release initiated by DL-provider (Figure D.6/T.70).](036ceaf207a7b289ca76e160892eb724_img.jpg) + +This sequence diagram illustrates the process of data link release initiated by a DL-provider. It involves three entities: DLS user (left), DLS provider (center), and DLS user (right). The diagram shows the following sequence of messages: + +- The DLS provider sends a **DL-DISCONNECT indication** to the left DLS user. +- The left DLS user sends a **DL-DISCONNECT indication** to the DLS provider. +- The left DLS user sends a **DL-DEACTIVATE request** to the DLS provider. +- The right DLS user sends a **DL-DEACTIVATE request** to the DLS provider. +- The right DLS user sends a **DL-DEACTIVATE confirm** to the DLS provider. +- The left DLS user sends a **DL-DEACTIVATE confirm** to the DLS provider. + +The diagram is labeled with **DLSAP** at the bottom of each vertical line and includes the reference **T0817800-94/d38** at the bottom right. + +Sequence diagram for DL-release initiated by DL-provider (Figure D.6/T.70). + +FIGURE D.6/T.70 +DL-release initiated by DL-provider + +#### D.1.2.4 Data link resetting + +See Figures D.7 to D.10. + +![Sequence diagram for successful resetting (Figure D.7/T.70).](ec3647789b5c38fb686f2a0833324e79_img.jpg) + +This sequence diagram illustrates the successful resetting process between two DLS users and a central DLS provider. The participants are labeled at the top: DLS user, DLS provider, and DLS user. The diagram shows the following sequence of events: + +- The left DLS user sends a **DL-RESET indication** to the DLS provider. +- The DLS provider sends an **FRMR** (Frame Reset Request) to the right DLS user. +- The right DLS user sends a **DL-RESET indication** to the DLS provider. +- The DLS provider sends a **DL-RESET response** to the right DLS user. +- The right DLS user sends a **DL-RESET response** to the DLS provider. +- The DLS provider sends a **SABM** (Set Asynchronous Balanced Mode) to the left DLS user. +- The DLS provider sends a **UA** (Unnumbered Acknowledgment) to the left DLS user. + +At the bottom, the DLS provider's interface is labeled **DLSAP** on both sides. The reference **T0817810-94/d39** is noted in the bottom right corner. + +Sequence diagram for successful resetting (Figure D.7/T.70). + +FIGURE D.7/T.70 +Successful resetting + +![Sequence diagram for resetting not accepted by the receiver of FRMR (Figure D.8/T.70).](7fe5741e83bc9702d1b1d7585ddf66bd_img.jpg) + +This sequence diagram illustrates the scenario where resetting is not accepted by the receiver of the FRMR. The participants are labeled at the top: DLS user, DLS provider, and DLS user. The diagram shows the following sequence of events: + +- The left DLS user sends a **DL-RESET indication** to the DLS provider. +- The DLS provider sends an **FRMR** (Frame Reset Request) to the right DLS user. +- The right DLS user sends a **DL-RESET indication** to the DLS provider. +- The DLS provider sends a **DL-RESET response** to the right DLS user. +- The right DLS user sends a **DL-DISCONNECT request** to the DLS provider. +- The DLS provider sends a **DL-DISCONNECT indication** to the left DLS user. +- The DLS provider sends a **UA** (Unnumbered Acknowledgment) to the left DLS user. +- The DLS provider sends a **DL-DISCONNECT confirm** to the right DLS user. + +At the bottom, the DLS provider's interface is labeled **DLSAP** on both sides. The reference **T0817820-94/d40** is noted in the bottom right corner. + +Sequence diagram for resetting not accepted by the receiver of FRMR (Figure D.8/T.70). + +FIGURE D.8/T.70 +Resetting not accepted by the receiver of FRMR + +![Sequence diagram for Figure D.9/T.70 showing a reset sequence where the transmitter of FRMR does not support resetting. The diagram involves three lifelines: DLS user (left), DLS provider (middle), and DLS user (right). The left DLS user sends a DL-RESET indication to the DLS provider. The DLS provider sends FRMR to the right DLS user. The right DLS user sends a DL-RESET indication to the DLS provider. The DLS provider sends a DL-RESET response to the right DLS user. The left DLS user sends a DL-DISCONNECT request to the DLS provider. The DLS provider sends SABM to the right DLS user. The right DLS user sends a DL-DISCONNECT indication to the DLS provider. The DLS provider sends DM to the left DLS user. The left DLS user sends a DL-DISCONNECT confirm to the DLS provider. The DLS provider sends UA to the right DLS user. The diagram is labeled T0817830-94/d41.](12c19090355e19922e23044633b9d1ea_img.jpg) + +``` + +sequenceDiagram + participant L as DLS user + participant P as DLS provider + participant R as DLS user + L->>P: DL-RESET indication + P->>R: FRMR + R->>P: DL-RESET indication + P->>R: DL-RESET response + L->>P: DL-DISCONNECT request + P->>R: SABM + R->>P: DL-DISCONNECT indication + P->>L: DM + L->>P: DL-DISCONNECT confirm + P->>R: UA + +``` + +T0817830-94/d41 + +Sequence diagram for Figure D.9/T.70 showing a reset sequence where the transmitter of FRMR does not support resetting. The diagram involves three lifelines: DLS user (left), DLS provider (middle), and DLS user (right). The left DLS user sends a DL-RESET indication to the DLS provider. The DLS provider sends FRMR to the right DLS user. The right DLS user sends a DL-RESET indication to the DLS provider. The DLS provider sends a DL-RESET response to the right DLS user. The left DLS user sends a DL-DISCONNECT request to the DLS provider. The DLS provider sends SABM to the right DLS user. The right DLS user sends a DL-DISCONNECT indication to the DLS provider. The DLS provider sends DM to the left DLS user. The left DLS user sends a DL-DISCONNECT confirm to the DLS provider. The DLS provider sends UA to the right DLS user. The diagram is labeled T0817830-94/d41. + +FIGURE D.9/T.70 + +**Resetting not supported by the transmitter of FRMR** + +![Sequence diagram for Figure D.10/T.70 showing a reset sequence where resetting is not accepted by both. The diagram involves three lifelines: DLS user (left), DLS provider (middle), and DLS user (right). The left DLS user sends a DL-RESET indication to the DLS provider. The DLS provider sends FRMR to the right DLS user. The right DLS user sends a DL-RESET indication to the DLS provider. The left DLS user sends a DL-DISCONNECT request to the DLS provider. The DLS provider sends DISC to the right DLS user. The right DLS user sends a DL-DISCONNECT request to the DLS provider. The DLS provider sends DISC to the left DLS user. The left DLS user sends a DL-DISCONNECT confirm to the DLS provider. The DLS provider sends UA to the right DLS user. The right DLS user sends a DL-DISCONNECT confirm to the DLS provider. The DLS provider sends UA to the left DLS user. The diagram is labeled T0817840-94/d42.](8d66c9c295023a1380f9986d3663bb1e_img.jpg) + +``` + +sequenceDiagram + participant L as DLS user + participant P as DLS provider + participant R as DLS user + L->>P: DL-RESET indication + P->>R: FRMR + R->>P: DL-RESET indication + L->>P: DL-DISCONNECT request + P->>R: DISC + R->>P: DL-DISCONNECT request + P->>L: DISC + L->>P: DL-DISCONNECT confirm + P->>R: UA + R->>P: DL-DISCONNECT confirm + P->>L: UA + +``` + +T0817840-94/d42 + +Sequence diagram for Figure D.10/T.70 showing a reset sequence where resetting is not accepted by both. The diagram involves three lifelines: DLS user (left), DLS provider (middle), and DLS user (right). The left DLS user sends a DL-RESET indication to the DLS provider. The DLS provider sends FRMR to the right DLS user. The right DLS user sends a DL-RESET indication to the DLS provider. The left DLS user sends a DL-DISCONNECT request to the DLS provider. The DLS provider sends DISC to the right DLS user. The right DLS user sends a DL-DISCONNECT request to the DLS provider. The DLS provider sends DISC to the left DLS user. The left DLS user sends a DL-DISCONNECT confirm to the DLS provider. The DLS provider sends UA to the right DLS user. The right DLS user sends a DL-DISCONNECT confirm to the DLS provider. The DLS provider sends UA to the left DLS user. The diagram is labeled T0817840-94/d42. + +FIGURE D.10/T.70 + +**Resetting not accepted by both** + +## **D.2 State transition diagrams HDLC** + +### **D.2.1 The relation between the diagrams** + +The following diagrams (See Figures D.11 to D.16) describe the HDLC procedure as one functional unit. The first page comprises the whole protocol and the following page gives the details to specific states. + +### **D.2.2 Abbreviations** + +| | | +|-----------------|-----------------------------------| +| ABM | Asynchronous balanced mode | +| ADM | Asynchronous disconnected mode | +| R:xxx | Receive xxx (command or response) | +| R:Cxxx | Receive a command | +| R:Rxxx | Receive a response | +| S:xxx | Send xxx | +| F | Final bit | +| P | Poll bit | +| XXX | Not this condition | +| RC | Redrive counter | +| RCB | Redrive counter busy | +| IC | I-Frame counter | +| V <sub>su</sub> | Variable for sequence updating | + +Any state + +DL-DEACT req + +T3v +(T1∧RC=0) +∨RCB=0 + +Stop flag +DL-DEACT conf + +R: SABM + +6 + +R: UA, F=1 +VR: DM, F=1 + +0 + +3 + +3, 4, 5 + +S: DM, F=P +DL-DISC ind + +DL-DISC ind + +DL-ACT req +(Address A or B) + +R: DM, F=1 +∨F=0 + +R: DISCONNECTION + +DL-ACT conf +SET ADDRESS +SEND FLAG +SET T3 + +DL-DISC conf + +DL-DISC ind + +S: UA, F=P +DL-DISC ind + +1 + +R: COMMANDS, P=1 + +Disconnected +phase + +DL- +CON req + +S: DM, F=1 + +S: SABM, P=1 +SET T1 +RC=N2-1 +RESET T3 + +S: DM, F=P +DL-DISC ind + +ADM + +R: SABM + +DL-DISC ind +RESET T1 + +R: SABM + +S: UA, F=P + +R: DISCONNECTION + +R: DM, F=1 + +2 + +Link set-up +phase + +T1∧RC≠0 + +S: SABM, P=1 +RC=RC-1, SET T1 + +R: UA, F=1 + +DL-RESET resp + +S: UA, F=P +(N(R)=0, N(S)=0 +DL-CON ind +RESET T3 + +DL-CON conf +RESET T1 +N(R)=0, N(S)=0 + +SABM, P=1 +SET T1 +RC=N2-1 + +3 + +Information +transfer +phase + +R: FRMR + +R: NEF + +R: SABM + +S: FRMR, SET T1 +DL-RESET ind +RC=N2-1 + +S: UA, F=P +N(R)=0, N(S)=0 +RESET T1 + +S: UA, F=P +N(R)=0, N(S)=0 +DL-RESET ind + +DL-RESET ind + +R: SABM + +R: SABM +∧DL-RESET resp + +5 + +R: COMMAND, P=1 +∧DISC∧SABM + +4 + +S: UA, F=P + +ABM + +S: FRMR, SET T1 +RC=RC-1 + +S: FRMR, F=1 + +DL-DISC req + +DL-DISC req + +S: DISC, P=1 +SET T1 +RC=N2-1 + +DL-DISC req + +T1∧RC≠0 + +R: DISCONNECTION + +Link +disconnection + +S: DISC, P=1 +RC=RC-1 +SET T1 + +S: UA, F=P + +6 + +T0817850-94/d43 + +FIGURE D.11/T.70 + +**State transition diagram HDLC +(Data link control)** + +Recommendation T.70 (03/93) 47 + +![State transition diagram for HDLC data link control showing states 0 through 6 and transitions between them based on received (R) and sent (S) signals, categorized into ADM and ABM phases.](5b03dbbd1f7b826f363981eb476ab317_img.jpg) + +``` + +stateDiagram-v2 + [*] --> AnyState + AnyState --> 0 : DL-DEACT req + 0 --> 1 : DL-ACT req (Address A or B) / DL-ACT conf, SET ADDRESS, SEND FLAG, SET T3 + 1 --> 2 : DL-CON req / S: SABM, P=1, SET T1, RC=N2-1, RESET T3 + 2 --> 3 : R: UA, F=1 / DL-CON conf, RESET T1, N(R)=0, N(S)=0 + 3 --> 6 : DL-DISC req / S: DISC, P=1, SET T1, RC=N2-1 + 6 --> 1 : R: UA, F=1 or R: DM, F=1 / DL-DISC conf + + state ADM { + state "Disconnected phase" as DP + state "Link set-up phase" as LSP + 1 --> DP + 2 --> LSP + } + + state ABM { + state "Information transfer phase" as ITP + state "Link disconnection" as LD + 3 --> ITP + 6 --> LD + } + + %% Additional transitions + 1 --> 1 : R: COMMANDS, P=1 / S: DM, F=1 + 2 --> 1 : DL-DISC ind, RESET T1 + 2 --> 2 : T1 & RC != 0 / S: SABM, P=1, RC=RC-1, SET T1 + 3 --> 3 : R: SABM / S: UA, F=P, N(R)=0, N(S)=0, RESET T1 + 3 --> 4 : R: NEF / S: FRMR, SET T1, DL-RESET ind, RC=N2-1 + 4 --> 3 : R: SABM & DL-RESET resp / S: UA, F=P, N(R)=0, N(S)=0, RESET T1 + 4 --> 4 : R: COMMAND, P=1 & !DISC & !SABM / S: FRMR, F=1 + 3 --> 5 : DL-RESET ind + 5 --> 3 : DL-RESET resp / SABM, P=1, SET T1, RC=N2-1 + 6 --> 6 : T1 & RC != 0 / S: DISC, P=1, RC=RC-1, SET T1 + + %% Transitions to state 1 from various states + 3 --> 1 : R: DM, F=1 or F=0 / DL-DISC ind + 4 --> 1 : DL-DISC req + 5 --> 1 : R: DM, F=1 or F=0 / DL-DISC ind + 6 --> 1 : R: UA, F=1 or R: DM, F=1 / DL-DISC conf + +``` + +The diagram illustrates the state transitions for HDLC data link control. Key states include: + +- State 0:** Initial state after DL-DEACT req. +- State 1:** Disconnected phase. Transitions here from state 0 on DL-ACT req. +- State 2:** Link set-up phase. Entered from state 1 on DL-CON req. +- State 3:** Information transfer phase (ABM). Entered from state 2 on R: UA, F=1. +- State 4:** Error recovery state within ABM, entered on R: NEF. +- State 5:** Resetting state within ABM. +- State 6:** Link disconnection phase. Entered from state 3 on DL-DISC req. + +Phases are grouped into **ADM** (Asynchronous Disconnected Mode) covering states 1 and 2, and **ABM** (Asynchronous Balanced Mode) covering states 3, 4, 5, and 6. + +State transition diagram for HDLC data link control showing states 0 through 6 and transitions between them based on received (R) and sent (S) signals, categorized into ADM and ABM phases. + +![State transition diagram HDLC (3 information transfer phase, I-frame control)](2580688a4de0a29692805cc6ba4822d7_img.jpg) + +``` + + graph TD + S31((3.1)) -- "R: DL-DATA req" --> S31 + S31 -- "R: <CRR\vee CREJ> \wedge <N(R)=V(S)> \wedge P=1 \wedge BUSY" --> S31 + S31 -- "R: <CRR\vee CREJ> \wedge <N(R)=V(S)> \wedge P=1 \wedge \neg BUSY" --> S31 + S31 -- "R: RR \vee <CRR \wedge P=0> \wedge N(R)=V(S)" --> S31 + S31 -- "R: <CRR\vee CREJ> \wedge <N(R)\neq V(S)> \wedge P=1 \wedge BUSY" --> S31 + S31 -- "R: <CRR\vee CREJ> \wedge <N(R)\neq V(S)> \wedge P=1 \wedge \neg BUSY" --> S31 + S31 -- "R: RR \vee <CRR \wedge P=0> \wedge N(R)\neq V(S)" --> S31 + S31 -- "R: REJ \vee <CREJ \wedge P=0>" --> S31 + + S31 -- "IC > 0 \wedge DIFF < 7" --> S31 + + S31 -- "R: <RNR \vee <CRNR \wedge P=0> \vee T1> \wedge BUSY" --> S31 + S31 -- "R: CRNR \wedge P=1 \wedge BUSY" --> S31 + S31 -- "R: <CRNR \wedge P=0 \vee RNR \wedge T1> \wedge \neg BUSY" --> S31 + + S31 -- "R: RR F=1 \wedge N(R)=V(S)" --> S31 + S31 -- "R: [REJ \wedge F=1] \vee [RR \wedge F=1 \wedge N(R)\neq V(S)]" --> S31 + + S31 -- "R: <CRR \vee CRNR \vee CREJ \vee P=1> \wedge \neg BUSY" --> S32((3.2)) + S31 -- "T1 \wedge RC > 0 \wedge \neg BUSY" --> S32 + + S32 -- "R: RNR \wedge F=1" --> S32 + S32 -- "R: (CRR \vee CREJ \vee CRNR) \wedge P=1 \wedge BUSY" --> S32 + S32 -- "T1 \wedge RC > 0 \wedge BUSY" --> S32 + +``` + +Detailed description of the diagram transitions and actions: + +- State 3.1:** Central state for I-frame transfer. Transitions include handling of RR, RNR, REJ, CRR, CREJ, and CRNR frames with various P/F bit and BUSY conditions. +- Action Box (Top Left):** RESET T1, IC=IC+V(S)-N(R), V<sub>su</sub>=V(S)=N(R). +- Action Box (Top Center):** S: PH-DATA req, V(S)=V(S)+1, IC=IC-1, SET T1. +- Action Box (Top Right):** SET T1, V<sub>su</sub>=N(R) and RESET T1, V<sub>su</sub>=N(R). +- Action Box (Middle):** RESET T1, V<sub>su</sub>=N(R) and RESET T1, IC=IC+V(S)-N(R), V<sub>su</sub>=V(S)=N(R). +- State 3.2:** Timer recovery condition state. Transitions involve retransmission and recovery logic. +- Action Box (Bottom Left):** V<sub>su</sub>=N(R), SET T1, SET RC=N2-1, SET RCB=N2-1. +- Action Box (Bottom Center):** S: CRR, P=1, RC=RC-1, SET T1 and SET RC, RCB=RCB-1. +- Action Box (Bottom Right):** S: CRNR, P=1, RC=RC-1, SET T1. + +Note <sup>a)</sup> Alternatively to RR, P = 1 it is allowed to send PH-DATA req P = 1 or CREJ, P = 1. + +T0817860-94/d44 + +State transition diagram HDLC (3 information transfer phase, I-frame control) + +FIGURE D.12/T.70 +**State transition diagram HDLC + (3 information transfer phase, I-frame control)** + +48 Recommendation T.70 (03/93) + +![State transition diagram HDLC (3 information transfer phase, I-frame control with update of N(R) in timer recovery condition)](4162c218fc7881cd90fc9574e07d2327_img.jpg) + +R: <CRR ∨ CREJ> ∧ <N(R) = V(S)> ∧ P = 1 ∧ BUSY + +R: <CRR ∨ CREJ> ∧ <N(R) = V(S)> ∧ P = 1 ∧ ¬BUSY + +R: RR ∨ <CRR ∧ P = 0> ∧ N(R) = V(S) + +R: <CRR ∨ CREJ> ∧ <N(R) ≠ V(S)> ∧ P = 1 ∧ BUSY + +R: <CRR ∨ CREJ> ∧ <N(R) ≠ V(S)> ∧ P = 1 ∧ ¬BUSY + +R: RR ∨ <CRR ∧ P = 0> ∧ N(R) ≠ V(S) + +R: REJ ∨ <CREJ ∧ P = 0> + +R: DL-DATA req + +R: <<RNR ∨ <CRNR ∧ P = 0> ∨ T1> ∧ BUSY + +R: CRNR ∧ P = 1 ∧ ¬BUSY + +R: <CRNR ∧ P = 0 ∨ RNR ∨ T1> ∧ ¬BUSY + +R: CRNR ∧ P = 1 ∧ BUSY + +R: <CRR ∨ CRNR ∨ CREJ> ∧ P = 1 ∧ ¬BUSY + +R: RR F = 1 ∧ N(R) = V(S) + +R: RNR ∧ F = 1 + +R: [REJ ∧ F = 1] ∨ [RR ∧ F = 1 ∧ N(R) ≠ V(S)] + +R: [<RR ∨ REJ ∨ RNR> ∧ F = 0 ∨ <CRR ∨ CREJ ∨ CRNR>] ∧ ¬BUSY + +R: (CRR ∨ CREJ ∨ CRNR) ∧ P = 1 ∧ BUSY + +T1 ∧ RC > 0 ∧ ¬BUSY + +T1 ∧ RC > 0 ∧ BUSY + +RESET T1 + IC = IC + V(S) - N(R) + V<sub>su</sub> = V(S) = N(R) + +S: PH-DATA req + V(S) = V(S) + 1 + IC = IC - 1 + SET T1 + +SET T1 + V<sub>su</sub> = N(R) + +RESET T1 + V<sub>su</sub> = N(R) + +RESET T1 + V<sub>su</sub> = N(R) + +RESET T1 + IC = IC + V(S) - N(R) + V<sub>su</sub> = V(S) = N(R) + +V<sub>su</sub> = N(R), SET T1 + SET RC = N2 - 1 + SET RCB = N2 - 1 + +S: CRR, P = 1<sup>a)</sup> + RC = RC - 1 + SET T1 + +SET RC + RCB = RCB - 1 + V<sub>su</sub> = N(R) + +S: CRNR, P = 1 + RC = RC - 1 + SET T1 + +S: RNR, F = 1 + +S: RR, F = 1 + +S: RNR, F = 1 + +S: RR, F = 1 + +S: RNR, F = 1 + +S: CRNR, P = 1 + +S: RR, F = 1 + +S: RR, P = 1<sup>a)</sup> + +S: RNR, F = 1 +V<sub>su</sub> = N(R) + +V<sub>su</sub> = N(R) + +S: RR, F = 1 +V<sub>su</sub> = N(R) + +3.1 + +3.2 + +IC > 0 ∧ DIFF < 7 + +IC = IC + 1 + +Sending I-frame + +Timer recovery condition + +State transition diagram HDLC (3 information transfer phase, I-frame control with update of N(R) in timer recovery condition) + +<sup>a)</sup> Alternatively to RR, P = 1 it is allowed to send PH-DATA req P = 1 or CREJ, P = 1. + + FIGURE D.13/T.70 +**State transition diagram HDLC + (3 information transfer phase, I-frame control with update of N(R) + in timer recovery condition)** + +Recommendation T.70 (03/93) 49 + +![](701bc79e78b382bcfd3ba85597dbb9c3_img.jpg) + +``` + +graph TD + 3.1.1((3.1.1)) + 3.1.2((3.1.2)) + 3.1.3((3.1.3)) + + %% Receiving I-frame transitions + 3.1.1 -- "R: PH-DATA ind, N(S)=V(R), BUSY, N(R)=V(S)" --> 3.1.1 + 3.1.1 -- "R: PH-DATA ind, N(S)=V(R), BUSY, N(R)≠V(S)" --> 3.1.1 + + %% N(S) Sequence error condition transitions + 3.1.1 -- "R: PH-DATA ind, N(S)≠V(R), N(R)=V(S)" --> 3.1.2 + 3.1.1 -- "R: PH-DATA ind, N(S)≠V(R), N(R)≠V(S)" --> 3.1.2 + + 3.1.2 -- "R: PH-DATA ind, N(S)=V(R), N(R)=V(S)" --> 3.1.1 + 3.1.2 -- "R: PH-DATA ind, N(S)=V(R), N(R)≠V(S)" --> 3.1.1 + + 3.1.2 -- "R: PH-DATA ind, N(S)≠V(R), N(R)=V(S), P=1, BUSY" --> 3.1.2 + 3.1.2 -- "R: PH-DATA ind, N(S)≠V(R), N(R)≠V(S), P=1, BUSY" --> 3.1.2 + + %% BUSY condition transitions + 3.1.1 -- "R: PH-DATA ind, BUSY" --> 3.1.3 + 3.1.2 -- "PH-DATA ind, BUSY" --> 3.1.3 + 3.1.3 -- "RESET BUSY" --> 3.1.2 + 3.1.3 -- "PH-DATA ind" --> 3.1.3 + +``` + +The diagram shows transitions between states 3.1.1, 3.1.2, and 3.1.3. Action blocks include: +- For successful I-frame reception: $V(R)=V(R)+1$ , S: RR, F=P, DL-DATA ind, RESET T1 or SET T1, $V_{su}=N(R)$ . +- For sequence errors: S: REJ, F=P or F=1, RESET T1 or SET T1, $V_{su}=N(R)$ . +- For busy conditions: S: RNR, F=P. + +FIGURE D.14/T.70 +**State transition diagram HDLC +(3.1 information transfer phase, I-frame acknowledgement)** + +50 Recommendation T.70 (03/93) + +![State transition diagram HDLC (3.2 information transfer phase, I-frame acknowledgement in exceptional conditions). The diagram shows three states: 3.2.1, 3.2.2, and 3.2.3. Transitions are labeled with events and actions. Brackets on the right group transitions into 'Receiving I-frame', 'N(S) Sequence error condition', and 'BUSY condition'.](89f8aefc01866631793087542316cef2_img.jpg) + +State transition diagram HDLC (3.2 information transfer phase, I-frame acknowledgement in exceptional conditions) + +States: + +- 3.2.1 +- 3.2.2 +- 3.2.3 + +Transitions and Actions: + +- 3.2.1 to 3.2.1 (Self-loop): R: PH-DATA ind $\wedge$ N(S) = V(R) $\wedge$ $\overline{\text{BUSY}}$ + Action: V(R) = V(R) + 1, S: RR, F = P, DL-DATA ind +- 3.2.1 to 3.2.2: R: PH-DATA ind $\wedge$ N(S) $\neq$ V(R) + Action: S: REJ, F = P +- 3.2.1 to 3.2.3: R: PH-DATA ind $\wedge$ $\overline{\text{BUSY}}$ + Action: S: RNR, F = P +- 3.2.2 to 3.2.1: S: RR, F = P, DL-DATA ind +- 3.2.2 to 3.2.2 (Self-loop): R: PH-DATA ind $\wedge$ N(S) $\neq$ V(R) $\wedge$ P = 1 $\wedge$ $\overline{\text{BUSY}}$ + Action: S: REJ, F = 1 +- 3.2.2 to 3.2.3: PH-DATA ind $\wedge$ $\overline{\text{BUSY}}$ + Action: S: RNR, F = P +- 3.2.3 to 3.2.2: RESET BUSY +- 3.2.3 to 3.2.3 (Self-loop): PH-DATA ind $\wedge$ $\overline{\text{BUSY}}$ + Action: S: RNR, F = P + +Brackets on the right side of the diagram group transitions into three categories: + +- Receiving I-frame: Includes the self-loop on 3.2.1 and the transition from 3.2.1 to 3.2.2. +- N(S) Sequence error condition: Includes the transition from 3.2.2 to 3.2.1 and the self-loop on 3.2.2. +- BUSY condition: Includes the transition from 3.2.1 to 3.2.3, the transition from 3.2.3 to 3.2.2, and the self-loop on 3.2.3. + +T0817890-94/d47 + +State transition diagram HDLC (3.2 information transfer phase, I-frame acknowledgement in exceptional conditions). The diagram shows three states: 3.2.1, 3.2.2, and 3.2.3. Transitions are labeled with events and actions. Brackets on the right group transitions into 'Receiving I-frame', 'N(S) Sequence error condition', and 'BUSY condition'. + +FIGURE D.15/T.70 + State transition diagram HDLC + (3.2 information transfer phase, I-frame acknowledgement + in exceptional conditions) + +![State transition diagram HDLC for 3.2 information transfer phase, I-frame acknowledgement in exceptional conditions with update of N(R).](a2251e3bbfcd726b68cc50b091e53b02_img.jpg) + +The diagram illustrates the state transitions for the HDLC 3.2 information transfer phase during I-frame acknowledgement in exceptional conditions, specifically when updating $N(R)$ . The states are represented by ovals (3.2.1, 3.2.2, 3.2.3) and the actions by rectangles. + +**State 3.2.1:** Initial state. Transitions include a self-loop for $R: PH-DATA \text{ ind} \wedge N(S)=V(R) \wedge \overline{BUSY}$ with actions $V(R)=V(R)+1$ , $S: RR, F=P$ , $DL-DATA \text{ ind}$ , and $V_{su}=N(R)$ . Other transitions lead to 3.2.2 or 3.2.3. + +**State 3.2.2:** Reached from 3.2.1 via $R: PH-DATA \text{ ind} \wedge N(S) \neq V(R)$ or $R: PH-DATA \text{ ind} \wedge N(S)=V(R) \wedge \overline{BUSY}$ . It has a self-loop for $R: PH-DATA \text{ ind} \wedge N(S) \neq V(R) \wedge P=1 \wedge \overline{BUSY}$ with action $S: REJ, F=1$ , $V_{su}=N(R)$ . Transitions lead to 3.2.1 or 3.2.3. + +**State 3.2.3:** Reached from 3.2.1 via $R: PH-DATA \text{ ind} \wedge \overline{BUSY}$ or from 3.2.2 via $PH-DATA \text{ ind} \wedge \overline{BUSY}$ or $RESET \text{ BUSY}$ . It has a self-loop for $S: RNR, F=P$ . Transitions lead to 3.2.1 or 3.2.2. + +State transition diagram HDLC for 3.2 information transfer phase, I-frame acknowledgement in exceptional conditions with update of N(R). + +T0817900-94/d48 + +FIGURE D.16/T.70 +**State transition diagram HDLC** +**[3.2 information transfer phase, I-frame acknowledgement** +**in exceptional conditions with update of $N(R)$ ]** + +## D.3 Summary of frame definitions + +### D.3.1 Invalid frame + +- frames not properly bounded by flags; +- frames containing addresses other than A or B; +- frames with frame check sequence (FCS) error; +- frames containing less than 32 bits between flags. + +### D.3.2 Valid frames + +#### D.3.2.1 Not expected frames + +NEF, not expected frames (for the receiver) which lead to a frame reject condition (excluding frames with an FRMR control field): + +- | | | +|----------------------------------------------------------------------------------------------------------------------|--------| +| – a command or response control field that is undefined or not implemented; | Type W | +| – a frame with an information field which is not permitted or supervisory or unnumbered frame with incorrect length; | Type X | +| – an I-frame with an information field which exceeds the maximum established length; | Type Y | +| – a frame with an invalid N (R). | Type Z | + +#### D.3.2.2 Expected frames + +- frames which must lead to a reaction (in accordance with the Recommendation) by the receiving station; +- frames which must be ignored only in determined states by the receiving station. + +## D.4 X.21 service, controlled by the network layer + +### D.4.1 X.21 connection establishment + +See Figures D.17 and D.18. + +![Sequence diagram showing successful PHC establishment between X.21 user, X.21 provider, and X.21 user.](44c649b1c110b4cd617810ae17342927_img.jpg) + +``` +sequenceDiagram + participant U1 as X.21 user + participant P as X.21 provider + participant U2 as X.21 user + Note over U1: X.21-CONNECT + U1->>P: X.21-CONNECT + Note over P: X.21 SAP + P->>U2: X.21-CONNECT indication + U2->>P: X.21-CONNECT response + Note over U2: X.21 SAP + P->>U1: X.21-CONNECT confirmation + Note over P: X.21 SAP +``` + +The diagram illustrates the successful establishment of a Permanent Half-Circuit (PHC) in X.21. It involves three entities: an X.21 user on the left, an X.21 provider in the center, and another X.21 user on the right. The process begins with the first X.21 user sending an 'X.21-CONNECT' message to the X.21 provider. The provider then sends an 'X.21-CONNECT indication' to the second X.21 user, who responds with an 'X.21-CONNECT response' back to the provider. Finally, the provider sends an 'X.21-CONNECT confirmation' back to the first X.21 user. Vertical lines represent the lifelines of each entity, and horizontal arrows represent the messages. Labels 'X.21 SAP' are placed at the bottom of the provider's lifeline and below the second user's lifeline. + +Sequence diagram showing successful PHC establishment between X.21 user, X.21 provider, and X.21 user. + +FIGURE D.17/T.70 +Successful PHC establishment + +![Sequence diagram for Figure D.18/T.70: Not successful PHC establishment. It shows three lifelines: X.21 user, X.21 provider, and X.21 user. The first X.21 user sends an X.21-CONNECT request to the X.21 provider. The X.21 provider then sends a message to the second X.21 user. The X.21 provider also sends Call progress signals to the first X.21 user. Finally, the first X.21 user receives an X.21-DISCONNECT indication from the X.21 provider. The diagram is labeled T0817920-94/d50 at the bottom right.](c0b9e5fc63e19306394e0d4249da62cd_img.jpg) + +``` + +sequenceDiagram + participant U1 as X.21 user + participant P as X.21 provider + participant U2 as X.21 user + Note over U1, P: X.21 SAP + Note over P, U2: X.21 SAP + U1->>P: X.21-CONNECT request + P->>U2: + P->>U1: Call progress signals + P->>U1: X.21-DISCONNECT indication + +``` + +T0817920-94/d50 + +Sequence diagram for Figure D.18/T.70: Not successful PHC establishment. It shows three lifelines: X.21 user, X.21 provider, and X.21 user. The first X.21 user sends an X.21-CONNECT request to the X.21 provider. The X.21 provider then sends a message to the second X.21 user. The X.21 provider also sends Call progress signals to the first X.21 user. Finally, the first X.21 user receives an X.21-DISCONNECT indication from the X.21 provider. The diagram is labeled T0817920-94/d50 at the bottom right. + +FIGURE D.18/T.70 +**Not successful PHC establishment** + +### D.4.2 X.21 connection release + +See Figures D.19 to D.22. + +![Sequence diagram for Figure D.19/T.70: Disconnection initiated by the X.21 user. It shows three lifelines: X.21 user, X.21 provider, and X.21 user. The first X.21 user sends an X.21-DISCONNECT request to the X.21 provider. The X.21 provider then sends an X.21-DISCONNECT indication to the second X.21 user. The diagram is labeled T0817930-94/d51 at the bottom right.](e417ae35ab07134888be901c201d54cd_img.jpg) + +``` + +sequenceDiagram + participant U1 as X.21 user + participant P as X.21 provider + participant U2 as X.21 user + Note over U1, P: X.21 SAP + Note over P, U2: X.21 SAP + U1->>P: X.21-DISCONNECT request + P->>U2: X.21-DISCONNECT indication + +``` + +T0817930-94/d51 + +Sequence diagram for Figure D.19/T.70: Disconnection initiated by the X.21 user. It shows three lifelines: X.21 user, X.21 provider, and X.21 user. The first X.21 user sends an X.21-DISCONNECT request to the X.21 provider. The X.21 provider then sends an X.21-DISCONNECT indication to the second X.21 user. The diagram is labeled T0817930-94/d51 at the bottom right. + +FIGURE D.19/T.70 +**Disconnection initiated by the X.21 user** + +![Sequence diagram for Figure D.20/T.70: Disconnection initiated by the X.21 provider. It shows three lifelines: X.21 user, X.21 provider, and X.21 user. The X.21 provider sends an X.21-DISCONNECT indication to the first X.21 user and an X.21-DISCONNECT indication to the second X.21 user. The diagram is labeled T0817940-94/d52 at the bottom right.](237b76118be454462fc9b4e96adaa6c7_img.jpg) + +``` + +sequenceDiagram + participant U1 as X.21 user + participant P as X.21 provider + participant U2 as X.21 user + Note over U1, P: X.21 SAP + Note over P, U2: X.21 SAP + P->>U1: X.21-DISCONNECT indication + P->>U2: X.21-DISCONNECT indication + +``` + +T0817940-94/d52 + +Sequence diagram for Figure D.20/T.70: Disconnection initiated by the X.21 provider. It shows three lifelines: X.21 user, X.21 provider, and X.21 user. The X.21 provider sends an X.21-DISCONNECT indication to the first X.21 user and an X.21-DISCONNECT indication to the second X.21 user. The diagram is labeled T0817940-94/d52 at the bottom right. + +FIGURE D.20/T.70 +**Disconnection initiated by the X.21 provider** + +![State transition diagram for the network layer (calling side)](51d4540605fdfa2c090638305022143b_img.jpg) + +``` + + graph TD + StateGroup((State<br>0.4, 1.1, 2.1)) -- X.21-DISC ind --> Box1[DL-DEACT req<br>N-DISC ind] + Box1 --> S01((0.1<br>Idle)) + + S01 -- N-CON req --> Box2[X.21-CON req] + Box2 --> S02((0.2)) + + S02 -- X.21-CON conf --> Box3[DL-ACT req<br>(address A)] + Box3 --> S03((0.3)) + + S02 -- X.21-DISC ind --> Box4[N-DISC ind] + Box4 --> S01 + + S03 -- DL-ACT conf --> Box5[DL-CON req] + Box5 --> S04((0.4)) + + S03 -- X.21-DISC ind --> Box6[DL-DEACT req] + Box6 --> Box4 + + S04 -- DL-CON conf v DL-CON ind --> Box7[N-CON conf] + Box7 --> S11((1.1)) + + S04 -- DL-DISC ind --> Box8[DL-DEACT req<br>N-DISC ind] + Box8 --> S22((2.2)) + + S11 -- N-DATA req --> Box9[DL-DATA req] + Box9 --> S11 + + S11 -- DL-RESET ind --> Box10[DL-RESET resp<br>N-RESET ind] + Box10 --> S11 + + S11 -- DL-DATA ind --> D1{Inv. Header?} + D1 -- No --> D2{M-BIT} + D1 -- Yes --> Box11[N-DISC ind] + D2 -- Yes --> Box12[REASSEMBLY] + D2 -- No --> Box13[N-DATA ind] + Box12 --> S11 + Box13 --> S11 + + S11 -- N-DISC req --> Box14[DL-DISC req] + Box14 --> S21((2.1)) + + S11 -- DL-DISC ind --> Box8 + + S21 -- DL-DISC conf v DL-DISC ind --> Box15[DL-DEACT req] + Box15 --> S22 + + S22 -- DL-DEACT conf --> Box16[X.21-DISC req] + Box16 --> S01 + + S22 -- X.21-DISC ind --> S01 + + Box11 --> Box14 + + S11 -- N-RESET req --> D3{RESET} + D3 -- Yes --> S11 + D3 -- No --> Box11 + +``` + +State transition diagram for the network layer (calling side) + +T0817950-94/d53 + +FIGURE D.21/T.70 + +**State transition diagram for the network layer (calling side)** + +**Recommendation T.70 (03/93)** 55 + + + +TABLE D.1/T.70 + +### **Application rules regarding the network protocol data unit (NPDU)** + +| Conditions ↓ | | Combination of conditions | | | | | | | | | +|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------|---------------------------|-----|-----|-----|----------|-----|-----|-----|-----| +| | | a | b | c | d | e | f | g | h | i | +| C 1 | Transmit/receive | T | T | T | T | T | R | R | R | R | +| C 2 | NPDU length (octet) | > 2 | > 2 | > 2 | > 2 | < 3 | > 2 | > 2 | > 2 | < 3 | +| C 3 | 1st octet 01/<> | 01 | 01 | 01 | <> | * | 01 | 01 | <> | * | +| C 4 | 2nd octet bits 1 to 7 | 0 | 0 | <> | * | * | * | * | * | * | +| C 5 | 2nd octet bit 8 (M-bit) | 0 | 1 | * | * | * | 0 | 1 | * | * | +| Actions/applications rules | | | | | | | | | | | +| A 1 | Correct/acceptable | X | | | | X (Note) | | | | | +| A 2 | N-DISC ind, DL-DISC req | | | | | | | | X | X | +| A 3 | Not allowed | | X | X | X | X | | | | | +| A 4 | Error case | | | | | | | | X | X | +| <p>C Condition</p> <p>A Action/application rule</p> <p>T Transmit</p> <p>R Receive</p> <p><> Not equal</p> <p>* Not relevant</p> <p>X Valid/applicable</p> <p>NOTE – The Teletex system has to accept as many NPDUs, that at least, the same number of octets can be received as contained in the maximum negotiable transport block size.</p> | | | | | | | | | | | \ No newline at end of file diff --git a/marked/T/T-REC-T.80-199209-I_PDF-E/raw.md b/marked/T/T-REC-T.80-199209-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..ee026f1af334556910cb2e67a5f018ead63b8288 --- /dev/null +++ b/marked/T/T-REC-T.80-199209-I_PDF-E/raw.md @@ -0,0 +1,490 @@ + + +![ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside, crossed by a lightning bolt. + +INTERNATIONAL TELECOMMUNICATION UNION + +# CCITT + +THE INTERNATIONAL +TELEGRAPH AND TELEPHONE +CONSULTATIVE COMMITTEE + +## T.80 + +(09/92) + +**TERMINAL EQUIPMENT AND PROTOCOLS +FOR TELEMATIC SERVICES** + +--- + +**COMMON COMPONENTS FOR IMAGE +COMPRESSION AND COMMUNICATION – +BASIC PRINCIPLES** + +![CCITT logo: a stylized globe with the letters CITT inside.](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +CCITT logo: a stylized globe with the letters CITT inside. + +**Recommendation T.80** + +--- + +# FOREWORD + +The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988). + +Recommendation T.80 was prepared by Study Group VIII and was approved under the Resolution No. 2 procedure on the 18th of September 1992. + +## --- CCITT NOTE + +In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized private operating agency. + +© ITU 1993 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +# INTRODUCTION + +This Recommendation was prepared by CCITT SG VIII. The requirements, contained in clause 5, however, were forwarded to an informal CCITT-ISO/IEC “Joint Photographic Experts Group” (JPEG). The task of this Group was to develop a universal progressive/sequential compression algorithm for any type of colour model. + +During the development phase extensive testing and comparison of various techniques showed, that although the original goal was technically feasible, the initial solution did not produce the best compression and image-quality results for all the image types addressed. Therefore it was decided that JPEG should develop a progressive/sequential continuous-tone color and gray scale image compression technique (described in Recommendation T.81), while a newly formed separate group, CCITT-ISO/IEC “Joint Bi-level Image Group” (JBIG) should develop a separate (but from a functionality point of view similar) progressive/sequential bi-level (limited multi-level) image-compression technique (described in Recommendation T.82). Thus, there are many commonalities between the two techniques (such as their functionality, the use of a joint entropy coder, etc.), but the two techniques are different from an algorithm point of view. Reference to the JPEG and JBIG developed algorithm are provided in clause 2, Normative references. Both techniques were jointly standardized by CCITT and ISO/IEC. + + + +# **COMMON COMPONENTS FOR IMAGE COMPRESSION AND COMMUNICATION – BASIC PRINCIPLES** + +(1992) + +The CCITT, + +*considering* + +- (a) that the CCITT seeks the most efficient methods of coding, communication and storage of images; +- (b) that there is a growing interest in telematic services (such as facsimile, videotex, teleconferencing) and other CCITT applications to transmit images on telecommunication networks with varying speeds; +- (c) that there is a growing demand for multilevel (including gray-scale and continuous tone color) imagery; +- (d) that there is a trend to multifunctional terminals participating in more than one telematic services and/or other CCITT and/or data-processing applications; +- (e) that with the introduction of new telecommunication network technologies, such as ISDN, there is a growing tendency to provide multiple CCITT services and/or other applications on the same telecommunication network; +- (f) that there is an urgent demand for interworking among telematic services (and other CCITT applications) used for image-communication and/or image-storage; +- (g) that there is a strong convergence of image-processing, image-storage and image-communication techniques; +- (h) that there is strong tendency toward introducing “soft-copy” (i.e. screen oriented) image-communication services/applications; +- (i) that there is a need for harmonization of “soft-copy” (i.e. screen oriented) and “hard-copy” (i.e. print-oriented) image presentation modes, within the same, or among several CCITT services/applications, + +*recognizing* + +(j) that while several established techniques (see Recommendations T.4 and T.6) for efficient coding of images containing black and white text and line-drawings exist in CCITT without using new image-compression techniques, the needs expressed above can only partially be satisfied, unless new image-compression techniques are provided, + +*unanimously recommends* + +that in addition to image-compression techniques defined in Recommendations T.4 and T.6 a new generation of image-compression techniques containing new or improved properties (including, but not limited to: gray-scale/colour, progressive/sequential image build-up, lossy/lossless compression, be defined according to the T.80-Series Recommendations. + +# **1 Scope** + +The T.80-Series Recommendations are applicable to a wide range of CCITT applications which require use of compressed still images. Such images can range from bi-level to continuous-tone single-color and multi-color still digital image. It is applicable to a wide range of CCITT applications which require use of compressed images. + +This Recommendation is the introduction to the T.80-Series Recommendations. Recommendations T.81 and T.82 describe the individual image compression techniques. + +This Recommendation describes the basic principles of the requirements to be satisfied by the new compression techniques, the relation of those compression techniques to the individual CCITT applications and services. + +This Recommendation does not specify the individual compression techniques to be used. Neither does it specify, for a given application, a complete representation of coded image data, nor specify an application that is using any of the new compression techniques. + +## **2 Normative references** + +The following CCITT Recommendations and ISO/IEC International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and International Standards are subject to revision. + +- [1] CCITT Recommendation T.81 (1992) | ISO/IEC 10918-1:1992, *Information technology – Digital compression and coding of continuous-tone still images - Part I: Requirements and guidelines*. +- [2] CCITT Recommendation T.82 (1992) | ISO/IEC 11544:1992, *Information technology – Coded Representation of Picture and Audio Information – Progressive Bi-level Image Compression*. + +Informative references to other related CCITT Recommendations, ISO/IEC Standards and application oriented CCITT Recommendations are provided in the References clause. + +## **3 Definitions** + +For the purposes of this Recommendation, the following definitions apply. + +### **3.1 bi-level image** + +An image with two distinct levels of predefined colors (e.g. a typical facsimile image is a bi-level black-and-white image). + +### **3.2 bit-plane** + +An array (or “plane”) of bi-level symbols constructed from an image by choosing a particular bit from each pixel. + +### **3.3 byte** + +Eight bits of data. + +### **3.4 coding process** + +A general term referring to an encoding process, a decoding process, or both. + +### **3.5 color image** + +A bi-level or multi-level image containing more than one color component, defining the full color specification of that image. + +### **3.6 color component** + +One of the two-dimensional arrays which comprise a color image. The meaning of the color component is defined by the respective color model used. + +### 3.7 **color model** + +A defined way of describing colors. The color models selects the appropriate color components that are used to describe a specific color of an image sample. + +### 3.8 **complete representation of a coded image** + +A T.81 or T.82 data-stream embedded in the application (data) environment of a given CCITT application or service (e.g. in Photographic Data Syntax of Videotex). + +### 3.9 **compression** + +Reduction in the number of bits used to represent source image data. + +### 3.10 **continuous-tone image** + +An image whose color components contain a sufficient number of bits (color steps) per pixel, that the subjective appearance of the image appears continuous (e.g. 256 levels of gray provide the subjective impression of a true gray-scale image). + +### 3.11 **decoder** + +An embodiment of a decoding process. + +### 3.12 **decoding process** + +A process which takes as its input compressed image data and outputs either an equal to or similar to the original uncompressed image. + +### 3.13 **(digital) (still) image** + +A two-dimensional spatial array of image component data without time dimension, or a set of such arrays. + +### 3.14 **dithering** + +A technique applied to single bit-plane images, which makes the single bit-plane image appear subjectively as a continuous-tone image. When dithering is used in conjunction with a fixed image resolution, the result is a perceived "increase" in gray-levels. At the same time, however, the perceived image resolution decreases. + +### 3.15 **encoder** + +An embodiment of an encoding process. + +### 3.16 **encoding process** + +A process which takes as its input an original image as its input and outputs compressed image data. + +### 3.17 **entropy coder** + +Any lossless method for compressing data. + +### 3.18 **fixed-resolution progressive mode** + +A progressive image encoding/decoding process, whereby the quality of the image is improved by each successive step, while the original resolution of the image remains unchanged. + +### 3.19 **gray-scale image** + +A continuous-tone image with one color component only. + +### 3.20 **half-toning** + +An artificial coloring process (similar to dithering) used in printing that is applied to the bit-planes of the primary printing color components, and which results in a printout that subjectively appears to have continuous-tone color characteristics. + +### 3.21 **“hard-copy” image** + +An image which has been printed on an output device (a fixed, higher resolution image is usually expected). + +### 3.22 **hierarchical progressive mode** + +A progressive encoding/decoding process, such that, when decoding, a lower resolution image is decoded first, then by successive decoding steps, the resolution of the image is increased horizontally and vertically by predefined factors (usually by 2). In Recommendation T.82 this is the only type of “progressive” mode defined. + +### 3.23 **image data** + +Either source image data or reconstructed image data. + +### 3.24 **interleave** + +A sampling of different color components with different sampling frequencies. It results in different size of image resolutions for different color components. If correctly applied, remarkable compression gain can be achieved. + +### 3.25 **limited multi-level image** + +A term denoting that the precision with which each color component of a color image, or the single component a gray-scale image is specified, is limited to about two to seven bits. + +### 3.26 **lossless** + +A descriptive term for encoding and decoding processes in which the output of the decoding procedure is (data) identical to the input data to the encoding process. + +### 3.27 **lossy** + +A descriptive term for encoding and decoding processes which are not lossless, i.e. the decoding process output (data) is not identical with to the encoding process input (data). However, a lossy encoding and decoding process may produce an image with subjectively excellent image quality. Lossy coding compression is often applied in order to gain additional image compression. + +### 3.28 **multi-level image** + +A term for describing the precision-range of color components of a gray-scale or color image. Multi-level includes precision starting from about three levels (bits) to usually eight levels, but for some special applications 12, 16 or even higher. + +### 3.29 **picture** + +A bounded representation of visual information. + +### 3.30 **picture coding** + +The presentation in digital form of a picture, particularly for storage, interchange or processing. + +### 3.31 **pixel** + +One picture element of an image which is described by a rectangular array of such elements. + +### 3.32 **pixel aspect ratio** + +Definition of the actual shape of a single pixel, as defined by an application using the T.80-Series Recommendations. + +### 3.33 **photographic coding** + +A technique for representing pictures by means of pixels, using high resolution and a wide range of grey levels and/or colors giving a natural appearance. + +### 3.34 **progressive behaviour** + +A coding technique shows progressive behaviour if an image is first coded as a lowest resolution layer image and then is successively increased in resolution by means of differential layer images. + +### 3.35 **progressive coding** + +A method of describing the entire image is first described at a lower image quality (i.e. lower resolution image or an image without details) and then step-by-step successively build up and improve to the desired final image quality (i.e. final image resolution or image with many details). + +### 3.36 **progressive-compatible sequential coding** + +In Recommendation T.82, a method of coding an image, in which the image may be segmented into stripes, the image stripes are coded in sequence, and within each sequence, and within each stripe the image is coded to full resolution progressively. This is compatible by stripe/layer data reordering with progressive coding. + +### 3.37 **quantization** + +A process to represent an analogue signal source by an appropriate digital value. + +### 3.38 **sample** + +A sample represents one element in the two-dimensional array which comprises a component. In the image conversion process of the analogue source image into a digital image, “samples” are taken, line by line, in regular intervals. Depending on the application-dependent sampling process, the relation of samples to pixels is determined by factors, such as color model, interleave, sampling geometry, etc. + +### 3.39 **sequence behaviour** + +A coding technique shows sequential behaviour if portions of the image near the top are completely described before portions below have been described at all. + +### 3.40 **sequential coding** + +A method of describing an image in which portions of the image near to the top are completely described before portions below have been described at all. + +### 3.41 **single-progression sequential coding** + +In T.82, a method of coding an image, such that the image is fully coded in a single resolution layer, line by line, from left to right and top to bottom, without reference to any lower resolution images. This is compatible with progressive coding and progressive-compatible sequential coding, if the number of differential layers is zero. + +### 3.42 “soft-copy” image + +An image which is intended for a visual display unit as output device (thus usually variable lower resolutions are expected). + +### 3.43 spatial resolution + +The number of pixels used to describe a region of an image of fixed spatial size. + +### 3.44 subsampling + +A sampling technique whereby the sampling frequency of one color component is half, third, quarter, etc. of the sampling frequency of another color component. E.g. in CCIR 601 the sampling frequency of the chrominance component is half of the luminance component. Thus the chrominance component is subsampled. + +### 3.45 “tool-kit” + +A concept of providing a full set of common functional components (e.g. progressive build-up mode, lossy compression etc.) for image compression to be used by various image communication applications. Usually a given application uses only a logical subset of the entire “tool-kit”. + +## 4 Abbreviations + +| | | +|------|--------------------------------------------------------------------| +| CPU | Central Processing Unit | +| DPCM | Differential Pulse Code Modulation | +| DCT | Discrete Cosine Transform | +| JBIG | Joint Bi-level Image Group of CCITT-ISO/IEC | +| JPEG | Joint Photographic Experts Group of CCITT-ISO/IEC | +| MMR | Modified Modified READ Code (Algorithm used in Recommendation T.6) | +| TP | Typical Prediction (part of Recommendation T.82) | +| VLSI | Very Large Scale Integration | + +## 5 Requirements + +## 5.1 *Data quantization, sample precision* + +An overview of various type of picture data, presentation forms, and introduction to the basic concepts picture data is provided in Annexes A and B of ISO/IEC 9281-1. + +This Recommendation deals with still images made up of two-dimensional pixel arrays. Motion images – containing additionally to two-dimensional pixel arrays – also a time-component – are not a subject of this Recommendation. + +Both the source image and the reconstructed final image are presented by a color space which is encoded in an analogue signal form. Before an image compression algorithm, as described in T.80-Series Recommendations, can be applied, the image represented in analogue form must be converted (by sampling and quantization) to a digital form. The T.80-Series Recommendations compression schemes are concerned with the digital encoding/decoding of the image data only. The conversion process from analogue form into the digital form of data, and vice-versa, is outside of the scope of the compression schemes according to the T.80-Series Recommendations. + +The nature of conversion (sampling and quantization) is strongly influenced by the type of source image to be compressed: + +*Note* – In case of a scanned black/white document a bi-level (two-step) digital representation with a 50% gray-scale threshold is optimal from the storage point of view (1 bit/pixel in the uncompressed image). In case of a natural full-color image multi-level (usually 256) representation per color component is desirable to construct a true replica of the source image (usually 16-24 bits/pixel for the uncompressed image). The right selection of the quantization steps (often called precision) is outside of the scope of the techniques described in Recommendations T.81 and T.82. As a general guide-line, Recommendation T.81 is better suitable for multi-level continuous-tone images, and Recommendation T.82 for bi-level and/or limited multi-level images if lossy image compression is also sufficient. For lossless color images either Recommendation T.81 or T.82 can be applied. For bi-level lossless images only Recommendation T.82 is effective. The range of potential applicability of Recommendations T.81 and T.82 is illustrated for informational purposes in Figure 1/T.80. + +Both algorithms shall be prepared for a flexible, sufficiently narrow or wide range of precisions defined and parameterized by any application. More details can be found in Recommendations T.81 and T.82. + +![Diagram illustrating the typical application areas of T.81 and T.82 techniques. It shows the flow from source pictures (Continuous tone and Test, line drawing) through digital image data precision levels (1 to 8 bits/pixel/component) to compression processes (Multi-level, Limited multi-level, Bi-level). A table on the right categorizes these into Lossy (JPEG) and Lossless (JBIG) data.](e9314c83043183351ed74908e9bf2f90_img.jpg) + +Source picture: + +- 1) Image capturing (analogue signal, A/D conversion) +- 2) Image generation (digital signal) + +Digital image data Precision (bit/pixel/pomponent) + +Continuous tone image ("tone-art") + +Test, line drawing ("line-art") + +High precision + +Multi-level + +Limited multi-level + +Bi-level + +Compression process + +| Lossy | Loss-less | +|-----------------|-----------------| +| JPEG coded data | JBIG coded data | + +T0808430-92 + +Diagram illustrating the typical application areas of T.81 and T.82 techniques. It shows the flow from source pictures (Continuous tone and Test, line drawing) through digital image data precision levels (1 to 8 bits/pixel/component) to compression processes (Multi-level, Limited multi-level, Bi-level). A table on the right categorizes these into Lossy (JPEG) and Lossless (JBIG) data. + +FIGURE 1/T.80 + +Typical application areas of T.81 and T.82 techniques with regard to the digital quantization/precision of data + +## 5.2 Image resolution, interleave + +The resolution of an image shall be defined by the number of horizontal and vertical pixels. Both in Recommendations T.81 and T.82 the actual number of resolution shall be a parameter for the compression scheme. The actual definition of image resolution is defined by the CCITT service/application using T.81 and/or T.82 + +techniques. The range of the image resolution parameters shall be sufficient large enough to incorporate realistic size of images. More details can be found in Recommendations T.81 and T.82. + +The capability of interleave shall be supported to reduce the amount of data to code an image with high-fidelity. Interleave of color components result in different size of image resolutions for different color components. Sampling and actual resolutions of the individual color components are defined and controlled by the CCITT service/application using the compression techniques defined in Recommendations T.81 and T.82. T.81 and T.82 parametrization shall allow a great variety of interleave pattern. More details can be found in Recommendations T.81 and T.82. + +### 5.3 *Support of dithering and halftoning* + +Addaptive processing of halftone- and dither-images shall be supported by the T.80-Series Recommendations. + +*Note* – This requirement is new. Existing image compression methods defined in Recommendations T.4 and T.6 are tuned for text and line drawings, but perform badly on half-tone- and dither-images. + +### 5.4 *Lossy and lossless compression* + +The T.80-Series Recommendations specifie two classes of encoding and decoding processes, lossy and lossless processes. It is up to the CCITT service/application to define whether an application requires lossless compression, or whether a lossy compression also satisfied the quality requirements of that application. The requirement for lossy and/or lossless coding shall be signalized to the appropriate T.80-Series Recommendations by the application. + +*Note* – At this point in time, Recommendation T.81 supports both lossy and lossless coding, while Recommendation T.82 only lossless coding. + +The lossless encoding/decoding process shall produce an image data stream that is identical to the data stream of the original image. Thus, the source and final images data stream have to be identical. + +The lossy encoding/decoding process produces an image data stream that is different from the data stream of the original image. However, the subjective appearance of the final image shall be the same, or close to the original. + +*Note 1* – Based on the degree of lossyness, the appearance of the final image may vary between “subjectively identical” to the original and “noticeably different, but recognizable”. The former is suitable for many applications and produces a better compression as with lossless compression. The later is suitable for the first scan of a progressive image, a small size of “icon type” image, or a low quality image (e.g. for data base searches). + +*Note 2* – There are certain applications, such as medical images, high quality prints, images for subsequent image processing that require lossless data compression/decompression. The compression ratio for lossless images is, however, noticeably lower than for the same lossy image. Therefore, usually, the image quality achieved by lossy encoding/decoding process is lower than for lossless images. Image quality enhancement by local picture processing is possible, but it is outside of the scope of the T.80-Series Recommendations. + +*Note 3* – The right selection of the lossy/lossless parameter significantly influences data compression, and thus, transmission time and/or storage requirements. + +### 5.5 *Modes of operation* + +T.80-Series Recommendations specifie two distinct modes of operation, sequential and progressive. + +In a sequential encoding/decoding process, an image (or a color component of it) shall be processed from the top to the bottom. Depending on the compression technique applied, this can be done by entities of pixels, or by block of pixels, or by entire stripes of horizontal lines. The details are given in Recommendations T.81 and T.82. The sequential mode of operation may be either lossless or lossy. + +*Note* – The “sequential mode of operation” – as described in this Recommendation is also defined in Recommendations T.81 and T.82 (“sequential behaviour”). + +Recommendation T.81 distinguishes between “sequential DCT-based” (lossy process) and “lossless” (DPCM-based) operation mode. + +Recommendation T.82 defines a “single-progression sequential coding” operation mode that is compatible with the so-called “progressive-compatible” sequential coding (provided the number of differential layer is zero). An equivalent of this functionality is not defined/implemented in Recommendation T.81. + +In a progressive encoding/decoding process an image shall be processed in their entire integrity step-by-step, whereby after a first lower quality image after each decoding step, the quality of the reconstructed image improves step-by-step, until the final image quality. There are progressive processes where this may produce either a lossless progressive final image (Rec. T.82) or a lossy progressive final image (Rec. T.81) only. + +There are two distinct classes of progressive modes: *hierarchical* and *fixed-resolution* of progressive mode. + +In the hierarchical progressive mode, after each progressive step the horizontal and vertical resolution of the image multiplies by a predefined factor (usually by 2). + +*Note* – The “hierarchical progressive mode” – as defined in this Recommendation – is also defined in both Recommendations T.81 and T.82. + +Recommendation T.81, however, does not label its “hierarchical mode” as a type of “progressive mode”. In Recommendation T.81 the term “progressive” is left to what this Recommendation defines as the “fixed-resolution progressive mode”. + +Recommendation T.82, labels its “hierarchical mode” as “progressive mode”, because at this point in time no other form of progressivity is defined in Recommendation T. 82. + +In the fixed-resolution progressive mode, the resolution of the reconstructed image stays constant throughout the progressive build-up process. + +*Note* – The “fixed-resolution progressive mode” – as defined in this Recommendation – is defined in Recommendation T.81, but not in Recommendation T.82. + +Recommendation T.81 classifies its “fixed-resolution progressive mode” as “progressive DTC-based mode of operation”. + +The modes of operations are parameters of the compression techniques defined in Recommendations T.81 and T.82. Their selection is the task of the CCITT service/application referred to in Recommendations T.81 and T.82. + +### 5.6 *Hardware and software requirements referred to in Recommendations T.81 and T.82* + +The compression techniques defined in Recommendations T.81 and T.82 reflect a number of hardware and software requirements, which were established in order to allow a wide applicability of different algorithms: + +- “Tool-kit” (Common Components) concept; +- “Symmetrical” encoding/decoding; +- “Parallel” encoding/decoding; +- Support of “Hard-copy and/or “Soft-copy” applications; +- Compression targets; +- Computational complexity, speed targets; +- Robustness of implementation. + +#### 5.6.1 “Tool-kit” (Common components) concept + +Requirements are to be applicable to practically any kind of continuous-tone multi-level, limited-level, bi-level digital source images (i.e. for most practical purposes not to be restricted to images of certain dimensions, color spaces, pixel aspect ratios, etc.) and not to be limited to classes of imagery with restrictions on scene content (such as line drawing and/or text in case of Recommendations T.4 and T.6), including complexity, range of colors and statistical properties. + +To achieve the above goal, the concept of using for image compression “Common components” from a “Tool-kit” shall be a basic requirement. + +##### *Note – Advantages:* + +- various requirements of different imaging applications can be satisfied in a flexible way; +- use of common hardware/software components when implementing imaging application, make implementation easier and more economical; +- easier harmonization of different imaging for CCITT and ISO/IEC applications; +- easier implementation of interworking among imaging applications; + +##### *Disadvantages:* + +- Imaging applications using Recommendation T.81 and/or T.82 are not necessarily compatible; +- the T.80-Series “Tool-kit; is flexible, but very comprehensive; +- the employment of the T.80-Series compression methods in concrete application (including selection of proper parameters, defining resolutions, color models, interleave structure, pixel aspect ratio, communication protocols for transmission, etc.) is still a major task. + +#### 5.6.2 “Symmetrical” encoding/decoding + +The requirement of “symmetrical” encoding/decoding has two aspects: complexity of implementation, and “symmetricallity” in encoding/decoding time. + +*Note* – In practice the first requirement is very difficult to specify. In order to satisfy all types of applications, the main goal is to design a process which has about the same complexity requirement for the encoder and the decoder. In contrast to this, there are other encoding processes in practice, where the encoding process is more complex than the decoding process. There is a similar requirement for the encoding/decoding time, which should be about the same. + +#### 5.6.3 “Parallel” encoding/decoding + +The requirement of “parallel” encoding/decoding permits the start of decoding an image before the encoding process is finished. + +#### 5.6.4 Support of “Hard-copy” and/or “Soft-copy” applications + +The requirement to support “Hard-copy” and “Soft-copy” applications is achieved, especially by supporting the “progressive” build-up mode of operation. + +#### 5.6.5 Compression targets + +There are requirements to be at the state of the art with regard to compression rate and accompanying image fidelity, over a wide range of image quality ratings, in the range of “lossless” and in the “lossy” range where visual fidelity to the original is characterized as “excellent”, “good” and “fair”; also the encoder should be parametrizable, so that the application (or user) can set the desired compression/quality tradeoff. + +*Note* – For Recommendation T.81, the compression target was to compress a CCIR 601 4:2:2 continuous tone color image (source image precision: 16 bit/pixels) in “lossless” mode to about 8 bit/pixels, to an “excellent” quality “lossy” image with about 1.5 bit/pixel, to a “good” at about 0.75 bit/pixels and “fair” at 0.3 bit/pixels. It was a requirement, that there should be no significant difference between compression achieved by sequential and progressive build-up images. + +For Recommendation T.82, the compression target was to be superior to the compression technique described in Recommendation T.6. (MMR encoding). On scanned bi-level images of text and line drawings, observed compression gain ranged between 1.1 to 1.5. On computer generated bi-level images, including text and line drawings, compression ratios as much as 1.2 to 1.6 times those obtained with MMR were observed. On images where multilevel grey or color tones were rendered using bi-level halftoning or dithering, observed compression ratios have been from 2 to 30 those obtained with MMR. There was a requirement, that there should be no significant difference between compression achieved by sequential and progressive build-up images. + +#### 5.6.6 *Computational complexity, speed targets* + +There is a requirement to have traceable computational complexity to make feasible software implementations with viable performance on a range of CPUs, as well as hardware implementations with viable cost for applications requiring high performance. + +The requirements for target speed is an encoding/decoding throughput of up to 64 kbit/s. + +*Note* – Hardware tests have shown that VLSI implementations of T.81 and T.82 algorithms have practical complexity and have considerably higher data throughput than 64 kbit/s. + +Software implementations of T.81 with CCIR 601 4:2:2 type images have shown that current “industry standard PCs” are able to provide a coding/decoding throughput of around 64 kbit/s. Software implementations of Recommendation T.82 are slower. Moderately higher speed is provided by using either optional templates optimized for software implementations or TP (typical prediction). Both techniques are described in Recommendation T.82. + +#### 5.6.7 *Robustness of implementation* + +It is assumed that a given application using techniques defined in Recommendations T.81 and T.82 will use appropriate means to ensure the integrity of the compressed image data during transmission. Therefore, there is no requirement to implement error protection. Means shall, however, be provided to insert appropriate application marker codes into the compressed data stream, that provide aid to an underlying error correction mechanism. + +*Note* – There was a general requirement that the compression schemes defined in Recommendations T.81 and T.82 be sufficiently robust, to allow possible minimal negative effects should data transmission error occur. In practice, however, the compression schemes defined in the Recommendations T.81 and T.82 are not robust enough to tolerate data transmission errors. Therefore, error-free communication channels shall be used. + +# **References** + +- [1] CCITT Recommendation T.4 (1989), *Standardization of group 3 facsimile apparatus for document transmission*. +- [2] CCITT Recommendation T.6 (1989), *Facsimile coding schemes and coding control functions for group 4 facsimile apparatus*. +- [3] CCIR Recommendation 601 (1990), *Encoding parameters of digital television for studios*. +- [4] ISO/IEC 9281-1:1990, *Information technology – Picture coding methods – Part 1: Identification*. +- [5] CCITT Recommendation T.101 (1993), *International interworking for videotex services*. \ No newline at end of file diff --git a/marked/T/T-REC-T.805-201201-I_PDF-E/raw.md b/marked/T/T-REC-T.805-201201-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..18504070c0c6a557dd5beae5ef81d180b714f3a9 --- /dev/null +++ b/marked/T/T-REC-T.805-201201-I_PDF-E/raw.md @@ -0,0 +1,4611 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# T.805 + +(01/2012) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES +Still-image compression – JPEG 2000 + +--- + +**Information technology – JPEG 2000 image +coding system: Compound image file format** + +Recommendation ITU-T T.805 + +![ITU logo: A blue globe with red lightning bolts and the text 'ITU International Telecommunication Union'.](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with two red lightning bolts striking it. To the right of the globe, the text 'ITU' is written in a large, bold, blue font, and below it, the words 'International Telecommunication Union' are written in a smaller, blue font. + +ITU logo: A blue globe with red lightning bolts and the text 'ITU International Telecommunication Union'. + +# ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES** + +| | | +|-----------------------------------------------------|--------------------| +| Facsimile – Framework | T.0–T.19 | +| Still-image compression – Test charts | T.20–T.29 | +| Facsimile – Group 3 protocols | T.30–T.39 | +| Colour representation | T.40–T.49 | +| Character coding | T.50–T.59 | +| Facsimile – Group 4 protocols | T.60–T.69 | +| Telematic services – Framework | T.70–T.79 | +| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89 | +| Telematic services – ISDN Terminals and protocols | T.90–T.99 | +| Videotext – Framework | T.100–T.109 | +| Data protocols for multimedia conferencing | T.120–T.149 | +| Telewriting | T.150–T.159 | +| Multimedia and hypermedia framework | T.170–T.189 | +| Cooperative document handling | T.190–T.199 | +| Telematic services – Interworking | T.300–T.399 | +| Open document architecture | T.400–T.429 | +| Document transfer and manipulation | T.430–T.449 | +| Document application profile | T.500–T.509 | +| Communication application profile | T.510–T.559 | +| Telematic services – Equipment characteristics | T.560–T.649 | +| <b>Still-image compression – JPEG 2000</b> | <b>T.800–T.829</b> | +| Still-image compression – JPEG XR | T.830–T.849 | +| Still-image compression – JPEG-1 extensions | T.850–T.899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **Information technology – JPEG 2000 image coding system: Compound image file format** + +## Summary + +Recommendation ITU-T T.805 | International Standard ISO/IEC 15444-6 defines a normative but optional file format for storing compound images using the JPEG 2000 file format family architecture. This format is an extension of the JP2 file format defined in Recommendation ITU-T T.800 | ISO/IEC 15444-1 Annex I and uses boxes defined for both the JP2 file format and the JPX file format defined in Recommendation ITU-T T.801 | ISO/IEC 15444-2 Annex M. This Recommendation | International Standard is useful for applications storing multiple pages, images with mixed content, and/or images that need more structure than provided in JP2. + +Applications that implement this file format shall implement it as described in this Recommendation | International Standard. This Recommendation | International Standard: + +- specifies a binary container for multiple bi-level and continuous-tone images used to represent a compound image; +- specifies a mechanism by which multiple images can be combined into a single compound image, based on the mixed raster content (MRC) model; +- specifies a mechanism for grouping multiple images in a hierarchy of layout objects, pages and page collections; +- specifies a mechanism for storing JPEG 2000 and other compressed image data formats; +- specifies a mechanism by which metadata can be included in files specified by this Recommendation | International Standard. + +## History + +| Edition | Recommendation | Approval | Study Group | +|---------|----------------|------------|-------------| +| 1.0 | ITU-T T.805 | 2012-01-13 | 16 | + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at <http://www.itu.int/ITU-T/ipr/>. + +© ITU 2013 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +# CONTENTS + +| | <i>Page</i> | +|---------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 Normative references ..... | 1 | +| 2.1 Identical Recommendations International Standards ..... | 1 | +| 2.2 ITU, IEC and ISO references ..... | 2 | +| 2.3 Additional references ..... | 2 | +| 3 Definitions ..... | 3 | +| 4 Abbreviations ..... | 4 | +| 5 General arrangement ..... | 4 | +| 5.1 Mixed raster content model ..... | 5 | +| 5.2 File elements and structure ..... | 6 | +| 5.3 Hidden text metadata ..... | 14 | +| 5.4 JPM use scenarios ..... | 15 | +| Annex A – Compound image file structure ..... | 18 | +| A.1 File identification ..... | 18 | +| A.2 File organization ..... | 18 | +| A.3 Box definition ..... | 20 | +| A.4 Boxes used in a compound image file ..... | 20 | +| Annex B – Box definitions ..... | 23 | +| B.1 File level boxes ..... | 23 | +| B.2 Page level boxes ..... | 29 | +| B.3 Layout object level boxes ..... | 31 | +| B.4 Object level boxes ..... | 33 | +| B.5 JP2 codestream element boxes ..... | 36 | +| B.6 General/common boxes ..... | 37 | +| Annex C – Metadata ..... | 49 | +| C.1 Adding intellectual property rights information in JPM ..... | 49 | +| C.2 Adding vendor specific information to the JPM file format ..... | 49 | +| Annex D – Profiles ..... | 50 | +| D.1 JPM profiles ..... | 50 | +| D.2 Decompression profiles ..... | 51 | +| Annex E ..... | 52 | +| Annex F – Hidden text and annotations storage ..... | 53 | +| F.1 Storage of HTX in JPM ..... | 53 | +| F.2 Compression of HTX ..... | 53 | +| Annex G – Hidden text and annotations types and elements ..... | 54 | +| G.1 Overview ..... | 54 | +| G.2 Types ..... | 55 | +| G.3 Common attributes ..... | 56 | +| G.4 Elements ..... | 58 | +| Annex H – Hidden text and annotations schema ..... | 69 | +| H.1 XML schema ..... | 69 | +| Annex I – Hidden text and annotations examples ..... | 70 | +| I.1 Example 1 ..... | 70 | +| I.2 Example 2 ..... | 72 | +| I.3 Example 3 ..... | 72 | + +| | <i>Page</i> | +|----------------------------------------------------------------|-------------| +| Annex J – Guidelines for constructing URLs for JPM files ..... | 90 | +| J.1    Pages and layout objects ..... | 90 | +| J.2    Metadata boxes ..... | 90 | +| J.3    Labels..... | 90 | +| J.4    Page collections..... | 91 | +| J.5    Page thumbnails ..... | 91 | +| J.6    Document thumbnail..... | 91 | +| J.7    Byte ranges..... | 91 | + +# **Introduction** + +Recommendation ITU-T T.805 | ISO/IEC 15444-6 was prepared by ITU-T Study Group 16 and Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia information. + +ISO/IEC 15444 consists of the following parts, under the general title Information technology – JPEG 2000 image coding system: + +- Part 1: Core coding system +- Part 2: Extensions +- Part 3: Motion JPEG 2000 +- Part 4: Conformance testing +- Part 5: Reference software +- Part 6: Compound image file format +- Part 8: Secure JPEG 2000 +- Part 9: Interactivity tools, APIs and protocols +- Part 10: Extensions for three-dimensional data +- Part 11: Wireless +- Part 12: ISO base media file format +- Part 13: An entry level JPEG 2000 encoder +- Part 14: XML structural representation and reference + + + +## INTERNATIONAL STANDARD + +## RECOMMENDATION ITU-T + +## **Information technology – JPEG 2000 image coding system: Compound image file format** + +# **1 Scope** + +This Recommendation | International Standard defines a normative but optional file format for storing compound images using the JPEG 2000 file format family architecture. This format is an extension of the JP2 file format defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 Annex I and uses boxes defined for both the JP2 file format and the JPX file format defined in Rec. ITU-T T.801 | ISO/IEC 15444-2 Annex M. This Recommendation | International Standard is useful for applications storing multiple pages, images with mixed content, and/or images that need more structure than provided in JP2. + +Applications that implement this file format shall implement it as described in this Recommendation | International Standard. This Recommendation | International Standard: + +- specifies a binary container for multiple bi-level and continuous-tone images used to represent a compound image; +- specifies a mechanism by which multiple images can be combined into a single compound image, based on the mixed raster content (MRC) model; +- specifies a mechanism for grouping multiple images in a hierarchy of layout objects, pages and page collections; +- specifies a mechanism for storing JPEG 2000 and other compressed image data formats; +- specifies a mechanism by which metadata can be included in files specified by this Recommendation | International Standard. + +# **2 Normative references** + +The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations. + +## **2.1 Identical Recommendations | International Standards** + +- Recommendation ITU-T T.44 (1999) | ISO/IEC 16485/Amd 1:2000, *Information technology – Mixed Raster Content (MRC)*. +- Recommendation ITU-T T.44 Amd.1 (1999) | ISO/IEC 16485:2000 Amd 1, *Accommodation of new Annex B*. +- Recommendation ITU-T T.45 (2000), *Run-length Colour Encoding*. +- Recommendation ITU-T T.50 (1992) | ISO/IEC 646:1991, *International Reference Alphabet (IRA) (Formerly International Alphabet No. 5 or IA5) – Information technology – 7-bit coded character set for information interchange*. +- Recommendation ITU-T T.81 (1992) | ISO/IEC 10918-1:1994, *Information technology – Digital compression and coding of continuous-tone still images: Requirements and guidelines*. +- Recommendation ITU-T T.82 (1993) | ISO/IEC 11544:1993, *Information technology – Coded representation of picture and audio information – Progressive bi-level image compression*. +- Recommendation ITU-T T.83 (1994) | ISO/IEC 10918-2:1995, *Information technology – Digital compression and coding of continuous-tone still images: Compliance testing*. +- Recommendation ITU-T T.84 (1996) | ISO/IEC 10918-3:1997, *Information technology – Digital compression and coding of continuous-tone still images: Extensions*. + +- Recommendation ITU-T T.84 Amendment 1 (1999) | ISO/IEC 10918-3:1997/Amd 1:1999, *Provisions to allow registration of new compression types and versions in the SPIFF header.* +- Recommendation ITU-T T.86 (1998) | ISO/IEC 10918-4:1999, *Information technology – Digital compression and coding of continuous-tone still images: Registration of JPEG Profiles, SPIFF Profiles, SPIFF Tags, SPIFF colour Spaces, APPn Markers, SPIFF Compression types and Registration authorities (REGAUT).* +- Recommendation ITU-T T.87 (1998) | ISO/IEC 14495-1:2000, *Information technology – Lossless and near-lossless compression of continuous-tone still images – Baseline.* +- Recommendation ITU-T T.88 (2000) | ISO/IEC 14492:2001, *Information technology – Lossy/lossless coding of bi-level images.* +- Recommendation ITU-T T.800 (2002) | ISO/IEC 15444-1:2004, *Information technology – JPEG 2000 image coding system: Core coding system.* +- Recommendation ITU-T T.801 (2002) | ISO/IEC 15444-2:2004, *Information technology – JPEG 2000 image coding system: Extensions.* +- Recommendation ITU-T T.803 (2002) | ISO/IEC 15444-4:2004, *Information technology – JPEG 2000 image coding system: Conformance testing.* + +## 2.2 ITU, IEC and ISO references + +- Recommendation ITU-T T.4 (2003), *Standardization of Group 3 facsimile terminals for document transmission.* +- Recommendation ITU-T T.6 (1988), *Facsimile coding schemes and coding control functions for Group 4 facsimile apparatus.* +- Recommendation ITU-T T.42 (2003), *Continuous-tone colour representation method for facsimile.* +- Recommendation ITU-T T.89 (2001), *Application profiles for Recommendation T.88 – Lossy/lossless coding of bi-level images (JBIG2) for facsimile.* +- IEC 61966-2-1:1999-10, *Multimedia systems and equipment – Colour measurement and management – Part 2-1: Colour management – Default RGB colour space – sRGB.* +- IEC 61966-2-1/Amd.1:2003, *Multimedia systems and equipment – Colour measurement and management – Part 2-1: Colour management – Default RGB colour space – sRGB.* +- ISO 3166-1:1997, *Codes for the representation of names of countries and their subdivisions – Part 1: Country codes.* +- ISO 3166-2:1998, *Codes for the representation of names of countries and their subdivisions – Part 2: Country subdivision code.* +- ISO 5807:1985, *Information processing – Documentation symbols and conventions for data, program and system flowcharts, program network charts and system resources charts.* +- ISO 8601:2000, *Data elements and interchange formats – Information interchange – Representation of dates and times.* +- ISO/IEC 8859-1:1998, *Information technology – 8-bit single-byte coded graphic character sets – Part 1: Latin alphabet No. 1.* +- ISO/IEC 11578:1996, *Information technology – Open Systems Interconnection – Remote Procedure Call (RPC).* + +## 2.3 Additional references + +- IEEE Std. 754-1985, *IEEE Standard for Binary Floating-Point Arithmetic.* +- IETF RFC 1766 (1995), *Tags for the Identification of Languages.* +- IETF RFC 1950 (1996), *ZLIB Compressed Data Format Specification version 3.3.* +- IETF RFC 1951 (1996), *DEFLATE Compressed Data Format Specification version 1.3.* +- IETF RFC 2045 (1996), *Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies.* +- IETF RFC 2279 (1998), *UTF-8, a transformation format of ISO 10646.* +- IETF RFC 2396 (1998), *Uniform Resource Identifiers (URI): Generic Syntax.* +- W3C (2008), *Cascading Style Sheets, level 1 (CSS1) Specification.* <<http://www.w3.org/TR/REC-CSS1/>> + +- W3C (2011), *Cascading Style Sheets, level 2, revision 1 (CSS2) Specification*. <<http://www.w3.org/TR/REC-CSS2>> +- W3C (2008), *Extensible Markup Language (XML) 1.0, Fifth Edition*. <<http://www.w3.org/TR/REC-xml>> +- W3C (1999), *HTML 4.01 Specification*. <<http://www.w3.org/TR/html401>> +- W3C (2002), *XHTML™ 1.0 Extensible HyperText Markup Language, Second Edition*. <<http://www.w3.org/TR/xhtml1>> +- W3C (2004), *XML Schema Part 0: Primer, Second Edition*. <<http://www.w3.org/TR/xmlschema-0>> +- W3C (2004), *XML Schema Part 1: Structures, Second Edition*. <<http://www.w3.org/TR/xmlschema-1>> +- W3C (2004), *XML Schema Part 2: Datatypes, Second Edition*. <<http://www.w3.org/TR/xmlschema-2>> +- ICC.1:1998-09, *International Color Consortium, File Format for Color Profiles*. + +# 3 Definitions + +For the purposes of this Recommendation | International Standard, the following definitions apply. + +- 3.1 annotation:** Particular region of a page in a JPM document that has associated a URL reference, a note or a highlight. +- 3.2 base colour:** The colour of an object for which no image data is available. +- 3.3 BasePage:** The original state of the page before it is rendered with layout objects. +- 3.4 box:** A portion of the file format defined by a length and a unique box type. Boxes of some types may contain other boxes. +- 3.5 component:** A two-dimensional array of samples. +- 3.6 compound image:** An image that may contain scanned images, synthetic images or both, and that preferably requires a mix of continuous tone and bi-level compression methods. +- 3.7 compressed hidden text XML:** Hidden text XML data compressed using the mechanisms defined in clause F.2. +- 3.8 file format:** A codestream or codestreams and additional support and information not explicitly required for decoding of the codestream or codestreams. Examples of such support data include text fields providing security and historical information, data to support the placement of multiple codestreams within a given data file, and data to support exchange between platforms or conversions to other file formats. +- 3.9 fragment:** A portion of the codestream for an image. Clause 5.2.5 describes fragment usage. +- 3.10 hidden text:** Symbolic representation for the characters and words found in an image. +- 3.11 hidden text UUID box:** UUID box containing compressed hidden text XML. +- 3.12 hidden text XML:** XML data which describe hidden text and annotations for a single page in a JPM file and which conform to the schema in Annex H. +- 3.13 hidden text XML schema:** XML schema for hidden text XML, as defined in clause H.1. +- 3.14 JP2 file:** The name of a file in the file format described in Rec. ITU-T T.800 | ISO/IEC 15444-1. Structurally, a JP2 file is a contiguous sequence of boxes. +- 3.15 JPM file:** The name of a file in the file format described in this International Standard. A JPM file can contain one or more pages, composed from one or more layout objects, each of which is composed from at most two objects. Structurally, a JPM file is a contiguous sequence of boxes. +- 3.16 JPX file:** The name of a file in the file format described in Rec. ITU-T T.801 | ISO/IEC 15444-2. Structurally, a JPX file is a contiguous sequence of boxes. +- 3.17 layout object:** An entity that comprises at most two paired objects or MRC layers. +- 3.18 main page collection:** The main page collection contains all pages and page collections in a file. +- 3.19 mask object:** An object that is used to select the samples of a corresponding image object that are to be imaged on a page. +- 3.20 metadata:** Additional data associated with the image data beyond the image data. + +- 3.21 MRC:** Mixed raster content; a multi-layer imaging model described in Rec. ITU-T T.44 | ISO/IEC 16485. +- 3.22 object:** An image that is part of a layout object; an MRC layer. +- 3.23 page:** The largest collection of layout objects that can be imaged independently of any other layout objects; a canvas or frame for imaging. +- 3.24 page collection:** A collection of pages logically grouped together in a JPM file. Each page must be contained in at least one page collection. +- 3.25 PageImage<sub>k</sub>:** The image created by rendering the BasePage with the layout objects. The PageImage<sub>k</sub> are the images created by rendering the BasePage with the first *k* layout objects. +- 3.26 primary page collection:** A page collection which provides back and forward navigation in the main document associated with a page. +- 3.27 profile:** A subset of all possible field values in a file. +- 3.28 superbox:** A box that itself contains a contiguous sequence of boxes (and only a contiguous sequence of boxes). + +# 4 Abbreviations + +For the purposes of this Recommendation | International Standard, the following abbreviations apply. The abbreviations defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 clause 4 also apply. + +| | | +|---------------|-----------------------------------------------------------------------------------------------------| +| <b>DPI</b> | Dots per inch | +| <b>HTX</b> | Hidden Text XML | +| <b>IPR</b> | Intellectual Property Rights | +| <b>JP2</b> | JPEG 2000 File Format defined in Rec. ITU-T T.800 ISO/IEC 15444-1 | +| <b>JPX</b> | JPEG 2000 File Format defined in Rec. ITU-T T.801 ISO/IEC 15444-2; JPEG 2000 File Format Extended | +| <b>JPM</b> | JPEG 2000 File Format defined in this International Standard; JPEG 2000 File Format – Multilayer | +| <b>MRC</b> | Mixed Raster Content | +| <b>PPCLoc</b> | Primary Page Collection Locator | +| <b>UUID</b> | Universal Unique Identifier | + +# 5 General arrangement + +The purpose of this clause is to give an overview of this International Standard. Terms defined in previous clauses in this International Standard will also be introduced. (Terms defined in clauses 3 and 4 of Rec. ITU-T T.800 | ISO/IEC 15444-1 continue to apply in this International Standard.) Throughout this International Standard, text formatted as a NOTE in the following form is informative only: + +NOTE – Informative text appears here. + +This International Standard defines a file format for storing compound images using the JPEG 2000 file format family architecture. A compound image file contains multiple images, both contiguous tone and bi-level, together with composition models describing how the individual images are combined to generate the compound image. This International Standard is based on the multi-layer mixed raster content (MRC) imaging model, defined in Rec. ITU-T T.44 | ISO/IEC 16485. + +This International Standard defines a member of the JPEG 2000 file format family that enables the efficient processing, interchange and archiving of raster-oriented pages containing a mixture of multi-level and bi-level images. This efficiency is realized by representing the mixed-content image using multiple layers, determined by image type, and applying image specific encoding, spatial and colour resolution processing. A rasterized page may contain one or more image types, such as: multi-level continuous-tone or palettized (contone) content usually associated with naturally occurring images; bi-level detail associated with text and line-art; and multi-level colours associated with the text and line-art. This International Standard makes provisions for processing, interchange, and archiving of these image types in multiple layers and defines composition models which regenerate the desired image. + +## 5.1 Mixed raster content model + +A file that conforms with this International Standard contains one or more pages. The PageImage associated with a page is generated by combining the page's layout objects with the BasePage. + +The BasePage is the initial PageImage before any layout objects have been rendered. The BasePage has the same width and height as the page and is either transparent or filled with a single colour. BasePage is defined in clause 5.2.2.1. The layout objects are applied sequentially, in an order defined by the layout object identifier field in the layout object header boxes, to the BasePage to create the final PageImage. The layout object with a layout object identifier value of 0 is the page thumbnail and is not used in creating the PageImage. + +Associated with each layout object is a mask $M$ and an image $I$ . The mask $M$ is an opacity image and has only one component; $I$ can be greyscale or colour, with one or more components. $M$ and $I$ are defined in clause 5.2.3. Both $M$ and $I$ have the same width and height as the page. + +The following equations show the model for combining the BasePage and a sequence of $n$ layout objects with non-zero layout object identifier values to create the final PageImage. We will use the notation $N[c][x,y]$ to refer to the sample value at position $(x,y)$ in component $c$ of an image $N$ . + +$$\text{PageImage}_0[c][x,y] = \text{BasePage}[c][x,y] \quad (1)$$ + +$$\text{PageImage}_{m-1}[c][x,y] = \frac{s_m - M_m[c][x,y] \times \text{PageImage}_{m-1}[c][x,y] + M_m[0][x,y] \times I_m[c][x,y]}{s_m}, \quad m = 1, \dots, n \quad (2)$$ + +$$\text{PageImage}[c][x,y] = \text{PageImage}_n[c][x,y] \quad (3)$$ + +where $M_m[c][x,y]$ and $I_m[c][x,y]$ are the image sample values of component $c$ at position $(x,y)$ of the $m$ th layout object's mask $M$ and image $I$ respectively, and $s_m = 2^{\text{bit depth of } M_m} - 1$ . $M$ , $I$ and BasePage are defined in clauses 5.2.2.1 and 5.2.3. PageImage[c][x,y] is the final page image, obtained after combining all $n$ layout objects associated with the page. + +NOTE – Figure 1 shows a simple example of a PageImage constructed from a BasePage with a single solid colour and two layout objects. Note that white in the masks $M_0$ and $M_1$ denotes a value of 0. + +NOTE – In a JPM file, the mask and image objects in a layout object typically have different spatial resolutions. Therefore, they must be scaled to the same resolution and to the page resolution before they are combined to create a page image according to Equations 1-3. In a JPM file, the size of the mask, image and page are specified in page grid units, but their resolutions may not be specified. The scaling of the mask and image is specified by a scale factor. The method of scaling is not specified in this International Standard, although informative guidelines for scaling of the mask and image are provided. The page image would then be scaled to the resolution of the output device for rendering on a display or printer. As described here, there would be two separate scaling operations: in the first, the mask and image of successive layout objects are scaled to a common resolution and combined on the page; in the second, the resulting page image is scaled to the device resolution. In practice, these two scaling operations are often combined into a single, device-dependent and implementation-specific scaling operation. + +![Figure 1: Example compound document. The diagram illustrates the hierarchical composition of a compound document. It shows three levels of page images: PageImage0, PageImage1, and PageImage2. PageImage0 is a solid cyan rectangle. PageImage1 is a cyan rectangle containing a Siamese cat's head. PageImage2 is a cyan rectangle containing the same Siamese cat's head with the text 'Compound Cat' in red at the bottom. The transitions are defined by layout objects (I1, I2) and mask objects (M1, M2). I1 is a photo of a Siamese cat, M1 is its black silhouette mask, and PageImage1 is the result of compositing I1 onto PageImage0 using M1. I2 is a red rectangle, M2 is a white rectangle with a red bottom half, and PageImage2 is the result of compositing I2 onto PageImage1 using M2, with the text 'Compound Cat' added.](b9ecbc3baefab13719e000faa6e0c7eb_img.jpg) + +Figure 1: Example compound document. The diagram illustrates the hierarchical composition of a compound document. It shows three levels of page images: PageImage0, PageImage1, and PageImage2. PageImage0 is a solid cyan rectangle. PageImage1 is a cyan rectangle containing a Siamese cat's head. PageImage2 is a cyan rectangle containing the same Siamese cat's head with the text 'Compound Cat' in red at the bottom. The transitions are defined by layout objects (I1, I2) and mask objects (M1, M2). I1 is a photo of a Siamese cat, M1 is its black silhouette mask, and PageImage1 is the result of compositing I1 onto PageImage0 using M1. I2 is a red rectangle, M2 is a white rectangle with a red bottom half, and PageImage2 is the result of compositing I2 onto PageImage1 using M2, with the text 'Compound Cat' added. + +Figure 1 – Example compound document + +## 5.2 File elements and structure + +The files that conform to the format defined in this International Standard are called JPM files. At its core, a JPM file is a sequence of pages, where each page in turn is a sequence of layout objects. A layout object normally consists of a mask object and an image object. Mask and image objects are composited to build up the final page image according to Equations 1-3. The key elements or boxes of a JPM file are: page collections, page, layout object, and object. An object points to its image data directly via a contiguous codestream box or indirectly via a fragment table box. Like all members of the JPEG 2000 file format family, a JPM file begins with a JPEG 2000 signature box and a file type box. A compound image header box, containing general information about the file, is then followed by page collection, page, fragment table, contiguous codestream, media data and general metadata boxes. Refer to Annex B for constraints on the location of boxes in a JPM file. + +This list illustrates the hierarchical relationship between the key elements in a JPM file. A particular order of these boxes is not implied. Full details of all the boxes may be found in Annex B. + +- JPEG 2000 signature +- File type +- Compound image header +- Page collection + - Page + - Layout object + - Mask object + - Image object +- Fragment table +- Codestream fragment +- Contiguous codestream + +### 5.2.1 Page collections + +A JPM compatible file consists of a sequence of pages, each represented by a page box which occurs at the top level of the file and each of which can be rendered independently of any other page. Page collections are used to logically group pages in a JPM file. Page collections can be logically nested, so that a page collection can itself consist of one or more page collections and/or one or more pages. Page collections referred to from other page collections are called subsidiary page collections. All pages in a JPM file must be pointed to by at least one page collection. + +A page can be said to be contained in a page collection, but this does not mean that the page box is located within the page collection box. It is not. Page boxes and page collection boxes both occur at the top level of the file and are not contained within other boxes. + +A JPM file contains one page collection known as the main page collection which is used to locate all pages of the file. Any additional page collections in a JPM file are logically nested within the main page collection (see clause 5.2.1.3). A page collection box contains an optional label box, optional metadata (XML and/or UUID) boxes, and a page table box that contains the locations of the pages and page collections belonging to the page collection. + +It is recommended that optimized files have the main page collection located near the beginning of the file. While page boxes and page collection boxes occur at the top level of the file, they may be located in external files. This case may be viewed as equivalent to being at the top level of the file. + +Each page in a JPM file has a primary page collection. The purpose of a primary page collection is to enable navigation in the primary document to which the page belongs using the sequential order within the primary page collection, thus providing support for previous page and next page commands. + +Every page collection box contains a page table box. The page table box entries point to the locations of the page and page collection boxes within the page collection. A flag for each entry specifies whether the location is that of a page box or page collection box, as well as indicating whether the box contains a thumbnail or metadata. + +By walking the tree of pages and logically nested page collections in a page's primary page collection, all pages in the page's primary document can be reached. Every page (with the exception of a self-contained JPM file containing only a single page) has a primary page collection locator or PPCLoc box. This box points to the primary page collection of the page and provides an index, PIx, into that page collection's page table where the page is referenced. Then the next page and previous page can be found by walking one page forward or backward from the current page. + +NOTE – Multiple page collections can exist in a JPM file. Some may have functions other than basic navigation. A table of figures could point to those pages containing figures. A section table or chapter table might point to only the first pages of sections or chapters. Any page collections of this sort must be auxiliary page collections, since they provide redundant pointers to pages and page collections and are sparse rather than comprehensive (see clause 5.2.1.3). + +NOTE – Figure 2 illustrates a logical grouping of page collections PC and pages P in a JPM file. PCa is the main page collection and the primary page collection for pages P0, P8 and P9 and page collections PCb, PCc and PCe. In a JPM file, the page table box of the page collection box for PCa would reference the page boxes for P0, P8 and P9, and the page collection boxes for PCb, PCc and PCe. The primary page collection locator boxes in these page and page collection boxes would reference the page collection box for PCa. PCb is a subsidiary page collection of PCa and the primary page collection for pages P1, P6 and P7 and for page collection PCd. PCd is the primary page collection for pages P2, P3, P4 and P5. PCc is the primary page collection for pages P10 and P11. PCe is an auxiliary page collection, which references page collection PCc and page P5. + +![Figure 2: Example of page collections and pages. A hierarchical tree diagram showing the structure of page collections (PCa, PCb, PCc, PCd, PCe) and pages (P0, P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11). PCa is the root, containing P0, PCb, P8, P9, and PCc. PCb contains P1, PCd, P6, and P7. PCd contains P2, P3, P4, and P5. PCc contains P10 and P11. PCe is an auxiliary collection that references PCc and P5.](3f1987804d7d78bc3b3bc560e974280a_img.jpg) + +``` + +graph TD + PCa[PCa] --- P0[P0] + PCa --- PCb[PCb] + PCa --- P8[P8] + PCa --- P9[P9] + PCa --- PCc[PCc] + PCa --- PCe[PCe] + PCb --- P1[P1] + PCb --- PCd[PCd] + PCb --- P6[P6] + PCb --- P7[P7] + PCd --- P2[P2] + PCd --- P3[P3] + PCd --- P4[P4] + PCd --- P5[P5] + PCc --- P10[P10] + PCc --- P11[P11] + PCe -.- PCc + PCe -.- P5 + +``` + +Figure 2: Example of page collections and pages. A hierarchical tree diagram showing the structure of page collections (PCa, PCb, PCc, PCd, PCe) and pages (P0, P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11). PCa is the root, containing P0, PCb, P8, P9, and PCc. PCb contains P1, PCd, P6, and P7. PCd contains P2, P3, P4, and P5. PCc contains P10 and P11. PCe is an auxiliary collection that references PCc and P5. + +Figure 2 – Example of page collections and pages + +#### 5.2.1.1 Main page collection + +Each JPM file has one main page collection. The purpose of the file's main page collection is to comprehensively list all pages (and subsidiary page collections) within a JPM file. This allows random seeking to any of the pages in the file. + +The page boxes for these pages occur at the top level of the file format, as do media data boxes containing fragments of codestreams. Since these media data boxes may be large and since they would likely be interspersed with page boxes, the page boxes might be widely separated in the file. In a JPM file containing a client copy of several browsed pages of a server's JPM file, each successively viewed page and some portion of its codestream fragments would be appended in turn to the bottom of the file. An update to the main page collection allows each of these new pages to be located. + +The main page collection comprehensively references all pages and page collections by means of a hierarchical arrangement. Some pages may be referenced from a page collection beneath the main page collection, but all pages and page collections are part of the tree structure of the main page collection. + +A JPM file optimized for browsing would have the main page collection near the front of the file. On the other hand, a client copy created during a browsing session would likely have the main page collection appended to the end of the file each time it is modified. The old main page collection's page collection box could then be left in place but have its box type changed from "pcol" to "free". A later garbage collection step could delete these free boxes. Because of cases like this, the file format has a pointer to the main page collection included in the compound image header box near the top of the file. This makes it easy to locate the main page collection box. + +#### 5.2.1.2 Primary page collection + +Each page or page collection has a primary page collection. By way of distinction, each JPM file has a main page collection. A primary page collection is a property of a page or page collection, not a property of a JPM file. + +The primary page collection of a page is the page collection where a JPM reading application would find the "next page" and "previous page" for a current page. + +A primary page collection locator or PPCLoc box must appear in all page boxes and all page collection boxes, with the one exception detailed in the next paragraph. The PPCLoc box provides a pointer to the primary page collection of the page or page collection. This backward pointer enables a comprehensive tree walk to find all the pages and page collections in the file. + +The PPCLoc box is optional only in the case of a single-page, self-contained JPM file (i.e., one which has no external references). In this case, it appears that the page has no primary page collection, but in fact the file's main page collection functions as the page's primary page collection. + +The primary page collection of a page or page collection may not be in the local JPM file in which that page box or page collection box is located. The local file may, for example, have three single pages, each of which has been copied from one of three different remote files. Keeping the original primary page collection pointers for these pages pointing to the original remote files allows a user to keep browsing the original source document via next page and previous page commands. + +The main page collection for a file may be a copy of a subsidiary page collection on a remote server, for instance, in which case it would have the parent page collection on that remote server as its primary page collection. When the main page collection does not have a primary page collection, then the main page collection box shall not contain a PPCLoc box. + +#### 5.2.1.3 Auxiliary page collection + +Auxiliary page collections are page collections which provide redundant pointers to pages already pointed to in the logical tree structure of the main page collection. Examples of auxiliary page collections could include a list of figures or a list of tables. Auxiliary page collections still appear in the logical tree structure of the main page collection so that they can be located, but a flag is used to mark them as auxiliary. This way, a decoding application knows they are not to be used to perform a comprehensive tree walk through all the pages referenced in the main page collection. + +Auxiliary page collections appear in the main page collection to assist an application in locating them within the file, but they are not part of the logical tree that is walked to comprehensively locate all pages. They instead provide a redundant means of reaching selected pages and thus should be ignored when trying to determine the natural page order of the file. Auxiliary page collections can appear down in the hierarchy of the main page collection; they need not occur at the top level. + +Auxiliary page collections should be labelled by means of a label box in order to be useful to a receiving application. If they are labelled, then a decoding application could present the label to the end user and offer such options as "next page in List of Figures" and "previous page in List of Figures". + +As an example, if page 17 appears in the "List of Figures" page collection, the decoding application would return to that page collection to get the next or previous page containing a figure, but would return to the primary page collection for page 17 (by means of the PPCLoc box in page 17's page box) to find the next page or previous page. + +### 5.2.2 Pages + +A page in a JPM file is represented by a page box, a superbox that consists of a page header box, containing general information about the page, a page collection locator box, containing the location of the page's primary page collection, an optional base colour box, which describes the base page colour, optional metadata boxes, and layout object boxes, one for each layout object on the page. Full details of these boxes may be found in clause B.2. + +Pages occur at the top level of the file format. This means incremental updates to the file may be accomplished by simply appending new pages to the end of the file. Page boxes and boxes containing codestreams or portions of codestreams may be intermixed in the file. + +With the exception of document thumbnails, each image in a JPM files is logically associated with at least one page. + +#### 5.2.2.1 Base page + +The BasePage is the initial PageImage before any layout objects have been rendered. Let `page_width` and `page_height` be the width and height of the page respectively, as signalled in the page header box. + +Let `spc` be the colourspace in which the I images are to be combined to generate a PageImage. BasePage is an image with dimensions `page_width` and `page_height` and colourspace `spc`. + +If the PColour field of the page header box is 0 then the BasePage is transparent and contains the sample values of any underlying image, converted to the colourspace `spc`. + +If the PColour field of the page header box is 1 then every BasePage sample contains the representation of white in the colourspace `spc`. + +If the PColour field of the page header box is 2 then every BasePage sample contains the representation of black in the colourspace `spc`. + +If the PColour field of the page header box is 255 then there is a mandatory base colour box within the page box and every BasePage sample contains the `spc` representation of the colour indicated by the base colour box. + +### 5.2.3 Layout objects + +Within a page box, there are as many layout object boxes as there are layout objects on the page. A layout object box is a superbox that consists of a layout object header box, containing general information about the layout object, optional boxes containing metadata associated with the layout object, and one or two object boxes – either an image object box and/or mask object box, or a combined image/mask object box. + +Each object box contains an object header box identifying whether the object represents an image, a mask or a combined image/mask, specifying the location of any codestream associated with the object and containing positioning information for the object. + +An image object typically has a codestream associated with it, but may not, in which case the NoCodestream field in the image object header is set to 1. An image object may also have an associated constant colour or image base colour. If an image object does not have an associated codestream, then it must have a defined image base colour. A mask object or image/mask object, if present, must have a codestream associated with it and have NoCodestream=0. + +If an object has an associated codestream then the object header box is followed by an optional object scale box and a JP2 header box containing boxes describing the object data: an image header, colour specification, optional bits per component, palette, component mapping and channel definition boxes. + +Associated with each layout object is a single component opacity mask `M` and an image `I`, each with the same width and height as the containing page. + +The `I` images for the layout objects to be combined to generate a PageImage must all use the same colourspace and bit-depth. The colourspace to be used for the `I` images of layout objects may be decided by the implementer and is not defined by this International Standard. + +The general methods for generating the mask `M` and the image `I` associated with a layout object are described in clauses 5.2.3.2 and 5.2.3.4. + +Clause 5.2.3.1 describes the special case of generating a mask `M` and an image `I` from a JBIG 2 codestream with an associated Recommendation ITU-T 45 encoding of colour tags. + +#### 5.2.3.1 Colour tagged JBIG 2 layout objects + +If the layout object box contains an image object box with a compression type of Recommendation ITU-T T.45 (Run Length) coding then it must also contain a mask object box with a compression type of Recommendation ITU-T T.88 (JBIG 2), and both must have the NoCodestream field in the object header boxes set to 0. In addition, the following fields must be the same for the image and mask objects: + +- the OOff and OHoff fields in the object header boxes; +- the VRN, VRD, HRN, VRD fields in the scale boxes; +- the HEIGHT and WIDTH fields in the image header box in the JP2 header boxes. + +In clause 5.2.3.3.1, $m\_orig$ is the image obtained by decompressing the JBIG 2 codestream associated with the mask object box. + +In clause 5.2.3.4.1, $i\_orig$ is the image obtained by applying the colour tags associated with the image object box to the symbol occurrences in the JBIG 2 mask codestream as described in Recommendation ITU-T T.45. + +#### 5.2.3.2 Mask M for a layout object + +If the layout object box does not contain a mask object box or a combined image/mask object box, then the mask M for the layout object is defined to have a bit-depth of 1 and to have value 1 at all sample locations, i.e., $M[0][x,y] = 1$ . + +Clauses 5.2.3.3.1 – 5.2.3.3.5 define M when a codestream is associated with a mask object box or a combined image/mask object box in the layout object box. + +1. The first stage in generating M, described in clause 5.2.3.3.1, is to decode the mask object, converting to a bit-depth of 8 if the mask has a lower bit-depth, and ensuring that the samples use a "min is white" representation. +2. The second stage, described in clause 5.2.3.3.2, is to scale the mask. +3. The third stage, described in clause 5.2.3.3.3, is to clip the mask from the top and from the left. +4. The fourth stage, described in clause 5.2.3.3.4, is to position the mask on the page. +5. The fifth and final stage, described in clause 5.2.3.3.5, is to clip the mask to the layout window. + +These stages are described individually for clarity and an efficient JPM decoder may be able to combine one or more of these stages. + +Figure 3 illustrates the five stages for an example mask. Note that white in the images denotes a value of 0. + +![Figure 3: Example of generating M. The diagram illustrates five stages of mask generation: 1. Decoding the Mask: A circular mask with a walking figure, dimensions m_orig_height and m_orig_width. 2. Scaling the Mask: The same mask scaled to m_scaled_height and m_scaled_width. 3. Clipping the Mask: The scaled mask with a green box indicating clipping from the top and left, dimensions m_height and m_width, and offset m_OHoff. 4. Positioning the Mask: The masked figure positioned within a larger page frame with dimensions page_height and page_width, and offsets LHoff and LVoff. 5. Window Clipping the Mask: The final masked figure within a window of dimensions LHeight and LWidth, positioned within the page frame.](aa9441a5971655a79987d70fc551b26a_img.jpg) + +Figure 3: Example of generating M. The diagram illustrates five stages of mask generation: 1. Decoding the Mask: A circular mask with a walking figure, dimensions m\_orig\_height and m\_orig\_width. 2. Scaling the Mask: The same mask scaled to m\_scaled\_height and m\_scaled\_width. 3. Clipping the Mask: The scaled mask with a green box indicating clipping from the top and left, dimensions m\_height and m\_width, and offset m\_OHoff. 4. Positioning the Mask: The masked figure positioned within a larger page frame with dimensions page\_height and page\_width, and offsets LHoff and LVoff. 5. Window Clipping the Mask: The final masked figure within a window of dimensions LHeight and LWidth, positioned within the page frame. + +Figure 3 – Example of generating M + +##### 5.2.3.2.1 Decoding the mask + +If a mask object box is used then let $m\_orig$ be the image obtained by decompressing the associated codestream, otherwise let $m\_orig$ be the image containing only the opacity component of the image obtained by decompressing the associated codestream. Let $m\_orig\_width$ and $m\_orig\_height$ be the width and height of $m\_orig$ and let $b$ be the bit-depth of $m\_orig$ . + +If $b$ is 1 then, unless indicated otherwise by the codestream, samples of value 0 are assumed to represent white while samples of value 1 are assumed to represent black. + +If $b$ is greater than 1 then, unless indicated otherwise by the codestream, samples of value 0 are assumed to represent black while samples of value $2^b - 1$ are assumed to represent white. + +Let $grey$ be an image with bit-depth $g = \max(8, b)$ and the same width and height as $m\_orig$ . $grey$ , defined as follows: + +$$grey[0][x, y] = \begin{cases} 2^b - 1 - m\_orig[0][x, y] \times \frac{2^g - 1}{2^b - 1} & \text{if 0 represents black in } m\_orig \\ m\_orig[0][x, y] \times \frac{2^g - 1}{2^b - 1} & \text{otherwise} \end{cases} \quad (4)$$ + +##### 5.2.3.2.2 Scaling the mask + +If an object scale box is contained in the mask object box or combined image/mask object box then let $m\_VRN$ , $m\_VRD$ , $m\_HRN$ and $m\_HRD$ be the scaling factors contained in this box, otherwise let $m\_VRN$ , $m\_VRD$ , $m\_HRN$ and $m\_HRD$ all be 1. Let $m\_scaled$ be the result of scaling $grey$ vertically by the ratio $\frac{m\_VRN}{m\_VRD}$ and horizontally by the ratio $\frac{m\_HRN}{m\_HRD}$ , generating an image with bit-depth $g$ and dimensions: + +$$m\_scaled\_width = \left\lceil \frac{m\_HRN}{m\_HRD} \times m\_orig\_width \right\rceil \text{ and } m\_scaled\_height = \left\lceil \frac{m\_VRN}{m\_VRD} \times m\_orig\_height \right\rceil \quad (5)$$ + +NOTE – The method for scaling a binary or grey mask up or down is implementation specific. For example, the scaling may use nearest neighbour or bilinear interpolation. + +##### 5.2.3.2.3 Clipping the mask + +Let $m\_OVoff$ and $m\_OHoff$ be the vertical and horizontal offsets in the mask object box or combined image/ mask object box. + +Let $m\_clipped$ be an image with bit-depth $g$ , width $m\_width = \max(0, m\_scaled\_width - m\_OHoff)$ and $m\_height = \max(0, m\_scaled\_height - m\_OVoff)$ . $m\_clipped$ is defined as follows: + +$$m\_clipped[0][x, y] = m\_scaled[0][x + m\_OHoff, y + m\_OVoff] \quad (6)$$ + +##### 5.2.3.2.4 Positioning the mask + +Let $page\_width$ and $page\_height$ be the width of the page containing the layout object, as signalled in the page header box. Let $LVoff$ and $LHoff$ be the layout vertical and horizontal offsets in the layout object header box. + +Let $m\_pos$ be an image with a width of $page\_width$ and height of $page\_height$ , defined as follows: + +$$m\_pos[0][x, y] = \begin{cases} m\_clipped[0][x - LHoff, y - LVoff] & 0 \leq x - LHoff < m\_width \text{ and } 0 \leq y - LVoff < m\_height \\ 2^g - 1 & \text{otherwise} \end{cases} \quad (7)$$ + +##### 5.2.3.2.5 Window clipping the mask + +Let $M$ be an image with a width of $page\_width$ and height of $page\_height$ . Let $LWidth$ and $LHeight$ be the layout object width and layout object height as specified in the layout object header box. $M$ is defined as follows: + +$$M[0][x, y] = \begin{cases} m\_pos[0][x, y] & 0 \leq x - LHoff < m\_width \text{ and } 0 \leq y - LVoff < m\_height \\ 0 & \text{otherwise} \end{cases} \quad (8)$$ + +#### 5.2.3.3 Image I for a layout object + +Let *spc* be the colour space in which the I images are to be combined to generate a PageImage. + +If the layout object box contains an image in either an image object box or a combined image/mask object box and also contains a base colour box, then let *base* be the representation in colour space *spc* of the colour indicated by the base colour box; otherwise let *base* be the representation in colour space *spc* of the colour black. + +If the layout object box does not contain an image object box or a combined image/mask object box, then the image I for the layout object is defined to be an image in colour space *spc* where every sample has the colour *base*. + +If the layout object does contain an image object box or a combined image/mask object box, but with no associated codestream, then the image I for the layout object is also defined to be an image in colour space *spc* where every sample has the colour *base*. + +Clauses 5.2.3.4.1 – 5.2.3.4.5 define I when a codestream is associated with an image object box or a combined image/mask object box in the layout object box. + +1. The first stage in generating I, described in clause 5.2.3.4.1, is to decode the image object and convert the image to the *spc* colour space. +2. The second stage, described in clause 5.2.3.4.2, is to scale the image. +3. The third stage, described in clause 5.2.3.4.3, is to clip the image from the top and from the left. +4. The fourth stage, described in clause 5.2.3.4.4, is to position the image on the page. +5. The fifth and final stage, described in clause 5.2.3.4.5, is to clip the image to the layout window. + +These stages, as with those used to generate the mask M, are described individually for clarity and an efficient JPM decoder may be able to combine one or more of these stages. + +##### 5.2.3.3.1 Decoding the image + +If an image object box is used then let *i\_orig* be the image obtained by decompressing the associated codestream, otherwise let *i\_orig* be the image containing all but the last component of the image obtained by decompressing the associated codestream. Let *i\_orig\_width* and *i\_orig\_height* be the width and height of *i\_orig*. + +Let *conv* be the image obtained by converting *orig* to the colour space *spc*. + +##### 5.2.3.3.2 Scaling the image + +If an object scale box is contained in the image object box or combined image/mask object box then let *i\_VRN*, *i\_VRD*, *i\_HRN* and *i\_HRD* be the scaling factors contained in this box, otherwise let *i\_VRN*, *i\_VRD*, *i\_HRN* and *i\_HRD* all be 1. + +1. Let *i\_scaled* be the result of scaling *conv* vertically by the ratio $\frac{i\_VRN}{i\_VRD}$ and horizontally by the ratio $\frac{i\_HRN}{i\_HRD}$ , generating an image with dimensions: + +$$i\_scaled\_width = \left\lceil \frac{i\_HRN}{i\_HRD} \times i\_orig\_width \right\rceil \quad \text{and} \quad i\_scaled\_height = \left\lceil \frac{i\_VRN}{i\_VRD} \times i\_orig\_height \right\rceil \quad (9)$$ + +NOTE – An image may be scaled up using bilinear interpolation or, if it's a palette image, using nearest neighbour interpolation. An image may be scaled down using averaging followed by subsampling, or if it's a palette image, using subsampling. If the image is compressed using JPEG 2000, an implementation may also choose to use the progressive-by-resolution decompression feature to obtain a power-of-two reduced resolution image for scaling. + +##### 5.2.3.3.3 Clipping the image + +Let *i\_OVoff* and *i\_OHoff* be the vertical and horizontal offsets in the image object box or combined image/mask object box. + +Let *i\_clipped* be an image with bit-depth *g*, width *i\_width* = max(0, *i\_scaled\_width* – *i\_OHoff*) and *i\_height* = max(0, *i\_scaled\_height* – *i\_OVoff*). *i\_clipped* is defined as follows: + +$$i\_clipped[0][x,y] = i\_scaled[0][x + i\_OHoff, y + i\_OVoff] \quad (10)$$ + +##### 5.2.3.3.4 Positioning the image + +Let *page\_width* and *page\_height* be the width of the page containing the layout object, as signalled in the page header box. Let *LVoff* and *LHoff* be the layout vertical and horizontal offsets in the layout object header box. + +Let $i\_pos$ be an image with a width of $page\_width$ and height of $page\_height$ , defined as follows: + +$$i\_pos[0][x,y] = \begin{cases} i\_clipped[0][x - LHoff, y - LVoff] & 0 \leq x - LHoff < i\_width \text{ and } 0 \leq y - LVoff < i\_height \\ base[c] & \text{otherwise} \end{cases} \quad (11)$$ + +##### 5.2.3.3.5 Window clipping the image + +Let $I$ be an image with a width of $page\_width$ and height of $page\_height$ . Let $LWidth$ and $LHeight$ be the layout object width and layout object height as specified in the layout object header box. $I$ is defined as follows: + +$$I[0][x,y] = \begin{cases} i\_pos[0][x,y] & 0 \leq x - LHoff < i\_width \text{ and } 0 \leq y - LVoff < i\_height \\ 0 & \text{otherwise} \end{cases} \quad (12)$$ + +### 5.2.4 Thumbnails + +Thumbnails are an optional feature which allow an overview of a document or a page to be presented to an end user. There are two types of thumbnails: document thumbnails and page thumbnails. + +A document thumbnail offers an overview representation of an entire document, much as the cover or spine of a book serves to do. It may simply be a repetition of the page thumbnail for the title page. Document thumbnails may be JP2 compatible or not. + +A JPM file with a document thumbnail is created by adding a JP2 header box for the thumbnail image immediately after the file type box. The codestream for the thumbnail image must be contained in the first contiguous codestream box following the JP2 header box. + +NOTE – A JP2-compatible document thumbnail can be used in the construction of a JPM file that also conforms to the JP2 file format defined in Rec. ITU-T T.800 | ISO/IEC 15444-1. A JP2 compatible document thumbnail must use JPEG 2000 as the coder and appears to a JP2 reader to be a valid JP2 file. The JP2 compatibility flag is set in the file type box by adding the string "jp2\040" to the compatibility string. A JP2 reader shall then look for a JP2 header box and jump over any following boxes until it finds a contiguous codestream box. It would then access the image represented by the data in that box. When a document thumbnail is present, the file would contain a JP2 header box, and a contiguous codestream box near the beginning of the file, somewhere after the compound image header box and before the first page box, usually before the page collection box. + +A page thumbnail is simply the layout object in a page with layout object identifier 0. A page thumbnail layout object must be the first layout object in a page. Its presence is signalled by a flag in the page table which indicates that a given page pointed to from the page table contains a page thumbnail. Page thumbnails are optional. + +NOTE – Page thumbnails allow an overview of each individual page to be displayed. This can be used during navigation, for example to render a small icon near each node of a tree-like table of contents. It can also be used to allow the display of a more useful initial image onto a new page than simply the page's background colour while waiting for additional content to arrive. + +### 5.2.5 Contiguous and fragmented codestreams + +The codestream data for the objects of a page may either be a single contiguous codestream, or be composed of one or more codestream fragments. A codestream consisting of fragments is accessed via a fragment table box. A fragment list box lists the locations in the file, or external pointers to another file, for the codestream fragments. Each codestream fragment is contained within a media data box. If the codestream is not fragmented then the object shall contain the location of a contiguous codestream box containing the codestream data. Full details of these boxes may be found in Annex B.5. + +The fragment table mechanism permits any codestream to be broken up into an ordered list of fragments, each pointed to by its own offset and data reference. A data reference indexes into the data reference table and produces a string listing the filename or URI of an external file where the fragment is to be found. If the data reference is 0, the fragment is located in the current file. This mechanism allows fragments to be placed in an optimal position to support streaming of the data to a client application from a server, or to allow progressive refinement of multiple codestreams simultaneously. + +Fragments may start or stop at any byte boundary of the codestream. The length of each fragment is specified by the length parameter retrieved from the fragment table. If a fragment does not end at a point in the codestream where a full code block or full raster line can be decoded, the decoding application holds this additional information until the next fragment has been retrieved. The next fragment of the byte stream is then appended to the residual data from the prior fragment and then decoding is resumed. Codestreams having any compression type may be decoded in this way. + +Fragment table entries always point to codestreams. All header information that is required to decode the codestream, such as width and height, compression type or bit depth is stored in fields in the object box. + +### 5.2.6 Shared data + +A file can contain multiple boxes or fragments containing identical data. File size can be reduced by sharing these boxes, including by reference a box or fragment that occurs in one part of a JPM file in a different part of the same file or in a different JPM file. The two mechanisms for sharing boxes in a JPM file are a shared-data reference box and a cross-reference box. Wherever a shared-data reference or a cross-reference box occurs in the file, the data it references is treated as if it exists at the point in the file where the reference is located. The reference can be by means of either an identifier, in the case of a shared-data reference box (clause B.1.8), or a data reference including an offset and length, in the case of a cross-reference box (clause B.6.4). + +A shared-data reference box in a file uses an identifier that is defined in the same file; therefore this mechanism shall only be used to share data within a file. The cross-reference box uses a data reference and therefore may be used to share data across files. In the case of a reference to an offset from the beginning of the file and length, the offset applies before any substitution implied by the reference occurs. A shared data substitution would not be understood by a JP2-only reader, so that a JP2-conforming JPM file must include directly any box whose presence in the file is necessary for JP2 conformance. + +### 5.2.7 Metadata + +This International Standard allows metadata to be attached to any structural element of a JPM file, including the file or document itself, page collections, pages, layout objects and objects. This is indicated in the box definitions in Annex B by the inclusion of a "metadata" box in the data field of the container box. Whenever there is a reference to a metadata in a box definition, it is understood that the box may contain an XML box or a UUID box with metadata. These "metadata" boxes are defined in Annex C. + +## 5.3 Hidden text metadata + +Hidden text metadata is data representing the text, text elements and text flow associated with an image. In the context of this standard, hidden text is associated with a particular region of a page in a JPM document. + +Common uses for hidden text include text searching and highlighting, cut-and-paste, and text-to-speech processing. Hidden text describes the flow of the text on a page as well as the text elements. + +JPM allows a rich, multiple content-type representation of a document. Each region of a page may be encoded with a compression technique best suited to its characteristics. In regions containing text, high fidelity reproduction of the source image is retained by not replacing the text regions with a character-based rendition through OCR, but rather by using advanced coding methods such as JBIG2. Even OCR results with a 99 percent accuracy contain substantial numbers of errors per page which require expensive human labour to correct. The searchable nature of a character-based rendition can be obtained instead by associating hidden "dirty OCR" results with the corresponding text image. This standard defines a format for hidden text metadata. + +A key issue with hidden text is capturing the ambiguities seen by the OCR engine in a way that allows properly-constructed search engines to find whether and where a given word might be present in a text image. Properly captured, this information provides nearly as much searching precision as an approach using human-corrected "clean OCR" data, but at much lower cost. Search results are most useful where there are fewer false positives to weed through. Intelligent search engines can take account of such data as confidence and alternate characters or alternate words to appropriately alter the ranking of search hits on less certain characters. + +In many cases, true ambiguity exists in the image and it would confuse a human observer as well. In these cases, saving confidence values for characters and their alternatives or describing several alternative parsings of a string of characters into words can amount to saving the state of the OCR process to allow the problem to be revisited in a later stage, perhaps by a different engine or by access to first a general dictionary and then a set of more specialized dictionaries. + +As a last step, when a person is presented with the search results, they can dismiss a given search hit by comparison to the actual image data for a character or word. For this purpose (and to allow later-stage OCR processes to resume analysis on the image), bounding box rectangles can be defined for all the elements of the hidden text such as characters, words, lines, paragraphs and regions. By indicating a container relationship among these items, intelligent navigation and text selection can occur at character, word, line, paragraph boundaries. A reading order through these rectangles can be defined for what was in the image just a random placement of unrelated glyphs. + +While it is primarily designed for use by machines such as search engines, the hidden text can also serve as a crude (if "dirty") or adequate (if "clean") alternate representation for an image region to allow it to display on character-based devices (such as mobile phones) or small-area graphics devices (such as PDAs). + +Annotations are added to the document typically with a WYSIWYG editor to indicate URL references, notes, and to highlight key sections of the document text. Each annotation is associated with a particular region of a page in a JPM document. + +XML is used for hidden text and annotations because it is a format widely used to store structured information, and can be machine processed. + +## 5.4 JPM use scenarios + +### 5.4.1 Self-contained files and files with external references + +This clause is an informative section. Clause 5.2 outlines the structure of a JPM file. In a local file, typically all image content and parameter boxes are contained in a single file for ease of tracking and maintenance, and because local storage is available and local bandwidths are high. + +The multiple layout object model is a method of representing and constructing document images, which allows access paradigms based on the multiple objects in addition to providing compression advantages due to applying the optimal compression method to each object. In addition, document images have an internal structure that implies a reading order, unlike photographic images, so that breaking them into layout objects can bring streaming advantages where only the small area of the page (a column, say, or a paragraph) that is of interest is brought over and refined. + +The fragment table and cross reference features of the JPEG 2000 family of file formats provide enormous flexibility in the construction of files, whose contents are distributed across multiple files, some of which may be located remotely on networks such as the Internet. This clause examines some of the file organisations enabled by these features. + +Useful JPM files tend to have structural information boxes at the top and large codestream objects either at the bottom of the file or remotely located or both. This allows rapid parsing and seeking among the component parts of the file by first getting the necessary structural information and then seeking to the offsets specified in the local or remote files. + +Structural information includes such information as page table boxes, page collection boxes, label boxes and fragment table boxes. + +Page table boxes are a key structural feature. They refer to page boxes via page references. These references contain an offset, length and data reference for the page box associated with each page in the complete file. Each of these data references may be zero, indicating a page reference to a page box in the current file, or non-zero, indicating that the data reference value is to be used as an index into the data reference box. The data reference box contains an enumerated list of strings, each string being a file name or a URI pointing to an Internet file. + +### 5.4.2 Files prepared for the Internet + +JPM files prepared for use on the Internet will typically already have been decomposed into layers and perhaps also into separate layout objects. These preparation steps each give a measure of improved streaming performance in browsing remote JPM files. + +Such files would likely have structural information placed near the top of the file, with codestreams occurring later. Codestreams and subsets of codestreams are accessible directly by seeking to a point in the file indicated by entries in the fragment table associated with that codestream. + +### 5.4.3 Page collection example + +The main page collection of a very large multi-volume set of books such as an encyclopaedia should not point to each page individually; such a data structure would be too large to be brought over to a client before even the first page can be displayed. Instead, the main page collection might serve as what amounts to a table of contents and point to each of the front matter pages individually, then to page collections that each cover entire volumes: Volume A, Volume B and so on. Each of these "volume" page collections would reference "section" page collections that would reference "article" page collections, and so on. Each of these page collections could have an appropriate label applied by means of label boxes in their page collection boxes. + +A search of metadata for a term occurring on a few of the pages returns a new "search results" JPM file containing a single main "search results" page collection pointing to a handful of pages. The first entry in this page collection box would point directly to the first search result page. This would actually point to one of the pages in the encyclopaedia over on the server via an external reference. By navigating the "search results" page collection, the application can let the user go to the next search hit and previous search hit. If the user then finds the article of interest and wants to continue reading onto a page back in the remote encyclopaedia where no search hit occurred, they would then need a next page function as well. + +The client software would go to the PPCLoc box found in that page's page box. This entry has a pointer to the primary page collection box back in the main JPM file. This primary page collection box will then be used by the client software to first find the current page's entry in that page collection by means of the PIx portion of the PPCLoc box. The PIx + 1 entry in that page collection would be the next page. By that means, the previous and next pages can be found. + +### 5.4.4 Page collections in a client / server context + +The JPM file format places page boxes and page collection boxes at the file level (not within other superboxes) to assist with incremental browsing of pages. New pages or page collections drawn over from a server may simply be appended to the end of the local (incomplete) copy of the file. + +In a client/server environment such as the web, it would be common for a user of a client application to browse only certain pages of a multi-page JPM file on a server. An initial link could point the client application to a specific page in the server's JPM file. The client application would create a new local JPM file and could choose to continuously update it as portions of the server file are retrieved. This would ensure that the browser cache always contains a valid JPM file when browsing ceases. + +This local file would have a main page collection. The main page collection would initially contain just one page. As the user begins fetching additional pages, these would be appended to the local file and the main page collection's page table updated to point to each new local copy of a server page. At the end of browsing, a stand-alone file having no clear connection to the server file could exist on the client. + +A better way of performing this browsing step would be to copy the server's main page collection to the client prior to downloading any pages. This page collection would be fixed up to point to the server copies of the pages by creating a data reference to the server URL. Then, as the first page is brought down to the client, the main page collection is updated to point to the local page, while continuing to point to the server for all other pages. + +### 5.4.5 Example of a client/server interaction + +In a client/server system, a user might want to browse a multi-page JPM file on a server, and to begin on a page in the middle of that remote file. Perhaps a search engine found a hit on the JPM file metadata associated with that page. The URI returned by the search engine would point to the JPM file and could contain a construction such as <http://webimaging.org/test.jpm?page=page17>. This would instruct the JPM decoder subsystem of the browser to abort the download of the full JPM file as soon as the key structural boxes at the top of the box have completed downloading. Then, byte serving protocols would be used to retrieve only the ranges of bytes needed to render the data in the page box associated through the label box to label "page17." Each object box in each layout object box of a given page box may contain a fragment table reference to a fragment table box. By retrieving only enough of each layout object's fragments to render a rough initial version of the page, a full rendering of all the layout objects can be deferred. The end user could in parallel begin moving the mouse over the browser's display window to indicate which layout objects might better be refined next, based on their having been indicated as being of interest. + +During this interactive browsing session, fragments are streaming over to the client copy of the JPM file in an order that is quite different than the order in the server copy. Page 17 comes first in the client copy, where page 1 was more likely first in the server copy. Similarly, the layout objects within page 17 will have a different order in the client version of the page, since the user's mouse movements dictated their retrieval. The client version can nevertheless form a perfectly equivalent surrogate for the server version because the page tables and fragment tables in the client copy will have started out pointing entirely to fragments on the server. As fragments and page boxes stream partially over to the client, the appropriate entries in the page table boxes and fragment table boxes are updated to point to the appropriate segments of the client copy of the file whether it is just in the file cache or explicitly saved. + +When substantial changes are made to the fragment table, then the fragment table pointer can be changed to point to a new, post-pended fragment table at the end of the file, and the old fragment table can be turned into a free box. + +All the fragments of the data in the file could be retrieved either from another file located on the web server external to the server copy of the JPM file or from a file located on another web server, or from an external file located on the client machine. The fragment reference mechanism supports all of these sources of data fragments external to the main JPM file. + +Similarly, the cross reference mechanism provides a means for JPM boxes (as opposed to data fragments) to be located in any of those possible places as well. The cross-reference box has an offset, length and data reference that points to an internal or external location so that a box can be found. For cross references internal to the main file, shared-data reference boxes permit repeated boxes to appear only once, with the second and subsequent instances being included by reference to the first instance. The key difference between fragment tables and cross references is that cross references point to the beginning of the referenced box, whereas fragment table entries point directly to the first byte of the codestream fragment, beyond the beginning of any containing media data box or other box. + +### 5.4.6 Example of scanner capture + +In addition to supporting a variety of streaming and remote browsing behaviours, the file format can support data streams coming from high-speed document scanners, where the images are not yet optimised for viewing but must meet other stringent constraints, such as timing. These files are not heavily processed at scan time, but rather capture all the available image data (perhaps multiple images per page) coming from the scanner and capture software and save this data to make it available to downstream post-processing software that can convert it to a web-optimised form. + +Scanned files may have metadata specific to the scanning process. This could include scanner metrics such as histograms, skew angle measurements, or cropping rectangle specifications. Other metadata might describe the scanner model or date and time of scanning and so on. + +Scanned files have not been prepared for efficient browsing over a network. They are intended to involve minimal encoder processing effort in order to meet the speed constraints imposed by high-speed scanning. + +JPM files coming from a scanning subsystem would typically not have been decomposed into layers or layout objects, but may instead include an entire high-quality compressed colour or greyscale image suitable for use by a subsequent decomposition system. If the scanning system is also capable of producing a bitonal (depth 1 bit) image natively, it may wish to include both this image and the full colour image in the JPM file to assist downstream decomposition processing. Two different scanned images of the same content which have not been pre-processed according to the MRC model might be placed into a JPM file as follows: place the colour image as a layout object on one page and the bitonal image as a layout object on another page and associate the two pages by placing them together in a page collection. Appropriate label Boxes could clarify the relationship between the two images and indicate that they represent the same page. + +# Annex A + +## Compound image file structure + +(This annex forms an integral part of this Recommendation | International Standard.) + +This annex describes the structure and organization of a JPM file. A JPM file uses the file format architecture specified in Rec. ITU-T T.800 | ISO/IEC 15444-1. Therefore, a JPM file is a contiguous sequence of boxes. This annex defines a box and describes the notation used for the box definitions in this International Standard. This annex also lists the boxes that are used in a JPM file. + +## A.1 File identification + +The brand shall be 'jpm\040' for files that are completely defined by this part of this International Standard; the brand is defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 Annex I. JPM files are files that conform to this part of this International Standard. JPM files can be identified using several mechanisms. When stored in traditional computer file systems, files that conform to this part should have the file extension .jpm (readers should allow mixed case). On Macintosh file systems, the type code should be 'jpm\040'. The MIME type is image/jpm. + +## A.2 File organization + +A JPM file uses the file format architecture specified in Rec. ITU-T T.800 | ISO/IEC 15444-1. The binary structure of the file is a contiguous sequence of boxes. The start of the first box shall be the first byte of the file and the end of the last box shall be the last byte of the file. The binary structure of a box in a JPM file is identical to that defined in the JP2 file format (Rec. ITU-T T.800 | ISO/IEC 15444-1 clause I.4). + +This International Standard defines boxes mandatory to a JPM file, as well as several optional boxes. Other Recommendations | International Standards may define other boxes that may also be found within a JPM file. In all cases, the information contained within a JPM file shall be in the box format; byte-streams not in the box format shall not be found in a JPM file. + +A JPM file may be self-contained in that it contains all the data needed to composite the page or pages in the file. A JPM file may also reference images and data in external files. References to the content of an external file are by means of the data reference box (clause B.1.5) or cross-reference boxes (clause B.6.4). + +Schematically, the hierarchical organization of boxes in a JPM file is shown in Figure A.1. Boxes with dashed borders are optional in conforming JPM files. However, an optional box may define mandatory boxes within that optional box. In that case, if the optional box exists, those mandatory boxes within the optional box shall exist. This illustration specifies only the containment relationship between the boxes in the file. A particular order of those boxes in the file is not generally implied. The definition of a box will include whether or not that box is required to be found at a specific location within the file or another box. + +![Conceptual structure of a JPM file diagram showing nested boxes for various components like JPEG 2000 Signature, File Type, JP2 Header, Compound Image Header, Data Reference, Contiguous Codestream, Metadata, Shared Data Entry, Page Collection, Primary Page Collection Locator, Page Table, Page box, Page Header, Base Colour, HTX Reference, Hidden Text Metadata, Layout Object, Layout Object Header, Object box, Object Header, Base Colour, Object Scale, JP2 Header, Fragment Table, Fragment List, Media Data, and Hidden Text Metadata.](043e64d41a3368d138ace3816fd26469_img.jpg) + +The diagram illustrates the conceptual structure of a JPM file, organized into a series of nested boxes representing different components and their relationships. The structure is as follows: + +- JPM file** (Outermost container) + - JPEG 2000 Signature box (B.1.1) + - File Type box (B.1.2) + - JP2 Header box (B.1.3) + - Compound Image Header box (B.1.4) + - Data Reference box (B.1.5) + - Contiguous Codestream box (B.5.3) + - Metadata boxes (C.2) + - Shared Data Entry box (B.1.7) + - Page Collection box (B.1.6) + - Primary Page Collection Locator box (B.1.6.1) + - Metadata boxes (C.2) + - Page Table box (B.1.6.2) + - Page Collection box (B.1.6) + - Page box (B.2.1) + - Page Header box (B.2.1.1) + - Primary Page Collection Locator box (B.1.6.1) + - Base Colour box (B.6.1) + - Metadata boxes (C.2) + - HTX Reference box (B.6.6) + - Hidden Text Metadata box (B.6.5) + - Layout Object box (B.3.1) + - Layout Object Header box (B.3.1.1) + - Metadata boxes (C.2) + - Object box (B.4.1) + - Object Header box (B.4.1.1) + - Base Colour box (B.6.1.1) + - Object Scale (B.4.1.2) + - JP2 Header box (B.6.2) + - Object box (B.4.1) +- Fragment Table box (B.5.1) + - Fragment List box (B.5.1.1) +- Media Data box (B.5.2) +- Contiguous Codestream box (B.5.3) +- Hidden Text Metadata box (B.6.5) + +Conceptual structure of a JPM file diagram showing nested boxes for various components like JPEG 2000 Signature, File Type, JP2 Header, Compound Image Header, Data Reference, Contiguous Codestream, Metadata, Shared Data Entry, Page Collection, Primary Page Collection Locator, Page Table, Page box, Page Header, Base Colour, HTX Reference, Hidden Text Metadata, Layout Object, Layout Object Header, Object box, Object Header, Base Colour, Object Scale, JP2 Header, Fragment Table, Fragment List, Media Data, and Hidden Text Metadata. + +Figure A.1 — Conceptual structure of a JPM file + +The JPEG 2000 signature box identifies the file as being part of the JPEG 2000 family of file formats. + +The file type box specifies file type, version and compatibility, including specifying if this file is a conforming JPM file or if it may be read, at least in part, by a conforming JP2 or JPX reader. + +An optional JP2 header box may follow the file type box, describing a document thumbnail image for the JPM file. + +The compound image header box contains global information that describes the compound image file. + +The page collection box contains a page table box for locating the individual pages of a JPM file. + +The page box describes the page onto which its constituent layout objects are composited using the imaging model. It may also contain references to metadata associated with the page. The page box also contains one or more layout objects. + +A compound image file must contain a JPEG 2000 signature box, a file type box and a compound image header box. The file may or may not contain image data. Figure A.1 shows the data stored with the compound image file. + +The JPM format allows the codestreams in the image layers to be non-contiguous. This enables interleaving codestream fragments among images and inter-image progressive rendering, where multiple images are rendered progressively at the same time. + +The JPM format also allows the codestreams in the image layers to be stored outside but referenced from the compound image file. This means that the images used in a compound image can be stored separately from their parent compound image or JPM file. + +## A.3 Box definition + +Physically, each element in a JPM file is encapsulated within a binary structure called a box. That binary structure is defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 clause I.4. + +Annex B defines the boxes used in this part of this International Standard. Each box is described using the notation defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 clause I.3.6. + +The following additional information is provided in the box definitions. + +Box type: four character code and hexadecimal code for the box type + +Container: parent box name or file for the box + +Mandatory: Yes or no + +Quantity: number of boxes in the container + +Location: location of the box + +Box type is the value of the TBox field of the box. Mandatory indicates whether the box is required to be present in the box that contains it. Container specifies the box that contains the box being defined. Quantity is the number of boxes being defined that can occur in the container. Location describes where in the container the box being defined can occur. + +- Where not specified, all integer values are assumed to use the big endian byte order. +- Some boxes have values assigned to groups of bits within a field. In some cases there are bits, denoted by "x", that are not assigned a value for any field within a parameter. The fields shall contain a value of zero for all such bits. The decoder shall ignore these bits. + +## A.4 Boxes used in a compound image file + +Table A.1 lists the boxes used in a JPM file and defined or referenced within this International Standard. + +**Table A.1 – Boxes defined or referenced within this International Standard** + +| Box names | Types | Superbox | Comments (informative) | +|----------------------|-------------------------|----------|-----------------------------------------------------------------------------------------------------------------------------| +| Base colour | 'bclr'<br>(0x6263 6C72) | Yes | This box contains all the information specifying the colour of a page or of an object for which no image data is available. | +| Base colour value | 'bcvl'<br>(0x6263 766C) | No | This box specifies the component values for the colour of a page or of an object for which no image data is available. | +| Colour specification | 'colr'<br>(0x636F 6C72) | No | This box specifies the colourspace of an image. | + +Table A.1 – Boxes defined or referenced within this International Standard + +| Box names | Types | Superbox | Comments (informative) | +|---------------------------------|-------------------------------|----------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Compound image header | 'mhdr'<br>(0x6D68 6472) | No | This box contains general information about the compound image file, such as profile and version. | +| Contiguous codestream | 'jp2c'<br>(0x6A70 3263) | No | This box contains a valid and complete JPEG 2000 codestream. | +| Cross-reference | 'cref'<br>(0x6372 6566) | No | This box specifies that a box found in another location (either within the JPM file or within another file) should be considered as if it was directly contained at this location in the JPM file. | +| Data-reference | 'dtbl'<br>(0x6474 626C) | No | This box contains a set of pointers to other files or data streams not contained within the JPM file itself. | +| File type | 'ftyp'<br>(0x6674 7970) | No | This box specifies file type, version and compatibility information, including specifying if this file is a conforming JPM file. | +| Fragment list | 'flst'<br>(0x666C 7374) | No | This box specifies a list of fragments that make up one particular codestream within the file. | +| Fragment table | 'ftbl'<br>(0x6674 626C) | Yes | This box describes how a codestream has been split up or fragmented and then stored within the file. | +| Free | 'free'<br>(0x6672 6565) | No | This box contains data that is no longer used and may be overwritten when the file is updated. | +| Hidden text metadata | 'htxb'<br>(0x68747862) | Yes | This optional box contains hidden text and annotations. | +| HTX reference box | 'phtx'<br>(0x70687478) | No | This optional box can be used to point to hidden text metadata box contents at top file level. | +| Image header | 'ihdr'<br>(0x6968 6472) | No | This box specifies the size of the image and other related fields. | +| JP2 header | 'jp2h'<br>(0x6A70 3268) | Yes | This box contains a series of boxes that contain header-type information about a file containing a single image. | +| JPEG 2000 signature | 'JP\040\040'<br>(0x6A50 2020) | No | This box uniquely defines the file as being part of the JPEG 2000 family of files. | +| Label | 'lbl\040'<br>(0x6C62 6C20) | No | This box specifies a textual label for a Page box or a Page Collection box. | +| Layout object | 'lobj'<br>(0x6C6F 626A) | Yes | This box contains the information and image data needed to composite a mask-image object pair. | +| Layout object header | 'lhdr'<br>(0x6C68 6472) | No | This box describes the properties of the layout object and assigns each a unique identifier within the page. | +| Media data | 'mdat'<br>(0x6D64 6174) | No | This box contains generic media data, which is referenced through the fragment list box. | +| Object | 'objc'<br>(0x6F62 6A63) | Yes | This box contains all the image data and information for one object in a layout object. | +| Object header | 'ohdr'<br>(0x6F68 6472) | No | This box describes the properties of an object, identifying it as a mask, an image or a combined mask/image object, and assigns each object a unique identifier within the file. | +| Object scale | 'scal'<br>(0x7363 616C) | No | This box describes the scaling for an object before applying it to the page. | +| Page | 'page'<br>(0x7061 6765) | Yes | This box contains all the information needed to image a page including references to codestream data. | +| Page collection | 'pcol'<br>(0x7063 6F6C) | No | This box groups together the locations of a set of pages so that they are treated as related and associated with each other. | +| Page header | 'phdr'<br>(0x7068 6472) | No | This box describes the properties of a page and gives the number of layout objects in the page. | +| Page table | 'pagt'<br>(0x7061 6774) | No | This box gives the locations of the pages in a page collection and enables random access of pages in a file. | +| Primary page collection locator | 'ppcl'<br>(0x7070 636C) | No | This box gives the location of the primary page collection for the page collection. | + +**Table A.1 – Boxes defined or referenced within this International Standard** + +| <b>Box names</b> | <b>Types</b> | <b>Superbox</b> | <b>Comments (informative)</b> | +|-----------------------|----------------------------|-----------------|---------------------------------------------------------------------------------------------------------------------| +| Shared-data entry | 'sdat'<br>(0x7364 6174) | Yes | This box contains a box that can be referenced by an identifier from multiple places within a file. | +| Shared-data reference | 'sref'<br>(0x7372 6566) | No | This box can be used to insert a box in the file by reference to a previous occurrence of the box in the same file. | +| UUID | 'uuid'<br>(0x7575 6964) | No | This box contains vendor specific information. | +| UUID Info | 'uinf'<br>(0x7569 6E66) | Yes | This box contains additional information associated with a UUID. | +| XML | 'xml\040'<br>(0x786D 6C20) | No | This box contains vendor specific information in XML format. | + +# Annex B + +## Box definitions + +(This annex forms an integral part of this Recommendation | International Standard.) + +This annex defines the boxes that are used in a conforming JPM file and that shall be interpreted by all conforming readers. Each of these boxes conforms to the standard box structure as defined in clause A.3. + +## B.1 File level boxes + +### B.1.1 JPEG 2000 signature box + +Box type: 'JP\040\040' (0x6A502020) + +Container: File + +Mandatory: Yes + +Quantity: Exactly one + +Location: First box in file + +The format and structure of the JPEG 2000 signature box is defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 clause I.5.1. + +### B.1.2 File type box + +Box type: 'ftyp' (0x66747970) + +Container: File + +Mandatory: Yes + +Quantity: Exactly one + +Location: Immediately after the JPEG 2000 signature box + +The format and structure of the file type box is defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 clause I.5.1. + +The BR field in the file type box shall be 'jpm\040' for files that are completely defined by this International Standard. In addition, a file that conforms to this International Standard shall have at least one CLi field in the file type box, and shall contain the value 'jpm\040' in one of the CLi fields in the file type box. + +### B.1.3 JP2 header box (superbox) after file type box + +Box type: 'jp2h' (0x6A703268) + +Container: File + +Mandatory: No + +Quantity: At most one + +Location: Anywhere after the file type box + +The format and structure of the JP2 header box is defined in clause B.6.2. + +The first file level JP2 header box following the file type box describes a document level thumbnail of the JPM file. The first contiguous codestream following a file level JP2 header box shall contain the associated thumbnail codestream. If the JP2 header box and the contiguous codestream box are JP2 compatible, then the JPM file is JP2 compatible and 'jp2\040' occurs in the compatibility list in the file type box. See clause 5.2.5 for more details. + +### B.1.4 Compound image header box + +Box type: 'mhdr' (0x6D686472) + +Container: File + +Mandatory: Yes + +Quantity: Exactly one + +Location: Anywhere after the file type box + +The compound image header box contains general information about the compound image. It is recommended that this box be placed immediately after the file type box and any file level JP2 header box. + +The type of a compound image header box shall be 'mhdr' (0x6D686472). This box contains the following fields. + +![Diagram showing the organization of the contents of a compound image header box. The box is divided into sections: NP (Number of pages), SC (Self-contained), MPCOff (Main page collection offset), MPCLen (Main page collection length), MC (Mask coders), and IPR (Inter-page references). The SC, MPCOff, and MPCLen sections are grouped under the label 'P' (Profile ID). The MC and IPR sections are grouped under the label 'IC' (Image Coder).](14252bcd35912bd656e98b16b2ee51c0_img.jpg) + +Diagram showing the organization of the contents of a compound image header box. The box is divided into sections: NP (Number of pages), SC (Self-contained), MPCOff (Main page collection offset), MPCLen (Main page collection length), MC (Mask coders), and IPR (Inter-page references). The SC, MPCOff, and MPCLen sections are grouped under the label 'P' (Profile ID). The MC and IPR sections are grouped under the label 'IC' (Image Coder). + +Figure B.1 – Organization of the contents of a compound image header box + +- NP: Number of pages. This parameter specifies the number of page boxes in the compound image file and is stored as a 4-byte unsigned big endian integer. If not known, the value is 0. +- P: Profile ID; application profile or mode that must be supported to read this file. This value is stored as a 1-byte unsigned integer. Values defined in this specification are specified in Table B.1. See Annex D for full details of the profiles. + +Table B.1 – Legal P values + +| Value | Meaning | +|--------------|-----------------------| +| 0 | No profile specified | +| 1 | Web profile | +| other values | Reserved for ISO use. | + +- SC: Self-contained: This value is stored as a 1-byte unsigned integer. If it has value 1, then the file is self-contained and has no references to external data; otherwise, it has value 0. +- MPCOff: Main page collection offset. This field specifies the offset from the start of the file to the first byte of the main page collection box. This field is encoded as an 8-byte unsigned big endian integer. +- MPCLen: Main page collection length. This field specifies the length of the main page collection box. This field is encoded as a 4-byte unsigned big endian integer. +- MC: Mask coders; the coder or coders that may be used to compress the mask objects of the layout objects in this file. This field can be one or more bytes long, with values set bit-by-bit as specified in Table B.2. Bit 7, the extend bit, would be set when adding another byte to accommodate additional coders, such as an eighth, which would be assigned to bit number 8. + +Table B.2 – Mask coders + +| Values (bits)<br>MSB    LSB | Mask coder flags | +|-----------------------------|--------------------------------------------------------------------------------------------------------------------------------------------| +| xxxx xxx0<br>xxxx xxx1 | One dimensional Rec. ITU-T T.4 (MH) coding is not used<br>One dimensional Rec. ITU-T T.4 (MH) coding may be used | +| xxxx xx0x<br>xxxx xx1x | Two dimensional Rec. ITU-T T.4 (MR) coding is not used<br>Two dimensional Rec. ITU-T T.4 (MR) coding may be used | +| xxxx x0xx<br>xxxx x1xx | Rec. ITU-T T.6 (MMR) coding is not used<br>Rec. ITU-T T.6 (MMR) coding may be used | +| xxxx 0xxx<br>xxxx 1xxx | Rec. ITU-T T.82 (JBIG) coding is not used<br>Rec. ITU-T T.82 (JBIG) coding may be used | +| xxx0 xxxx<br>xxx1 xxxx | Rec. ITU-T T.800 (JPEG 2000) coding is not used<br>Rec. ITU-T T.800 (JPEG 2000) coding may be used | +| xx0x xxxx<br>xx1x xxxx | Rec. ITU-T T.88 (JBIG2) coding applying Rec. ITU-T T.89 is not used<br>Rec. ITU-T T.88 (JBIG2) coding applying Rec. ITU-T T.89 may be used | +| 0xxx xxxx<br>1xxx xxxx | Last byte specifying the coders which may be used<br>Extend with another byte specifying coders which may be used | +| other values | Reserved for ISO use | + +IC: Image coders; the coder or coders that may be used to compress the image objects of the layout objects in this file. This field can be one or more bytes long, with values set bit-by-bit as specified in Table B.3. Bit 7, the extend bit, would be set when adding another byte to accommodate future support for additional coders, such as an eighth, which would be assigned to bit number 8. + +**Table B.3 – Image coders** + +| Values (bits)<br>MSB LSB | Image coder flags | +|--------------------------|------------------------------------------------------------------------------------------------------------------------------------------| +| xxxx xxx0<br>xxxx xxx1 | Rec. ITU-T T.81 (JPEG) coding is not used<br>Rec. ITU-T T.81 (JPEG) coding may be used | +| xxxx xx0x<br>xxxx xx1x | Rec. ITU-T T.82 (JBIG) coding applying Rec. ITU-T T.43 is not used<br>Rec. ITU-T T.82 (JBIG) coding applying Rec. ITU-T T.43 may be used | +| xxxx x0xx<br>xxxx x1xx | Rec. ITU-T T.45 (Run-Length Colour Encoding) coding is not used<br>Rec. ITU-T T.45 (Run-Length Colour Encoding) coding may be used | +| xxxx 0xxx<br>xxxx 1xxx | Rec. ITU-T T.87 (JPEG-LS) coding is not used<br>Rec. ITU-T T.87 (JPEG-LS) coding may be used | +| xxx0 xxxx<br>xxx1 xxxx | Rec. ITU-T T.800 (JPEG 2000) coding is not used<br>Rec. ITU-T T.800 (JPEG 2000) coding may be used | +| 0xxx xxxx<br>1xxx xxxx | Last byte specifying the coders which may be used<br>Extend with another byte specifying coders which may be used | +| other values | Reserved for ISO use | + +IPR: Intellectual property. This parameter indicates whether this JPM file contains intellectual property rights information. This value is stored as a 1-byte unsigned integer. If the value of this field is 0, this file and the image files it contains do not contain rights information, and thus the file does not contain an IPR box. If the value is 1, then the file does contain rights information and thus does contain an IPR box as defined in clause C.1. Other values are reserved for ISO use. + +**Table B.4 – Format of the contents of the compound image header box** + +| Field name | Size (bits) | Value | +|------------|-------------|-------------------| +| NP | 32 | $0 - (2^{32}-1)$ | +| P | 8 | see Table B.1 | +| SC | 8 | 0 or 1 | +| MPCOff | 64 | $12 - (2^{64}-1)$ | +| MPCLen | 32 | $0 - (2^{32}-1)$ | +| MC | variable | see Table B.2 | +| IC | variable | see Table B.3 | +| IPR | 8 | 0–1 | + +### B.1.5 Data reference box + +Box type: 'dtbl' (0x6474626C) + +Container: File + +Mandatory: No + +Quantity: At most one + +Location: Anywhere after the compound image header box + +The data reference box contains an array of URLs that are referenced by this file. The data reference box is not a superbox because it does not contain only boxes. + +Data reference box entries are used by page table boxes, object header boxes and fragment list boxes to refer to data external to the JPM file. + +- In a page table box, a data reference and offset refer to an external page box or page collection box. +- In an object header box, a data reference and offset refer to an external fragment table box. + +- In a fragment list box within a fragment table box, a data reference and offset refer to an external codestream fragment. +- In a fragment list box within a cross-reference box, a data reference and offset refer to an external shared header or metadata fragment. + +The type of a data reference box shall be 'dtbl' (0x6474626C). This box contains the following fields: + +![Diagram showing the organization of the contents of a data reference box. It consists of a sequence of fields: NDR (Number of data references), followed by DR^1 (Data reference URL), and then DR^NDR (Data reference URL). The fields are represented as boxes with different shading patterns.](05eb72d372e4bf78e3d6a64949d77bcc_img.jpg) + +``` + + +-----+ +-----+ +-----+ + | NDR | | DR1 | | DRNDR | + +-----+ +-----+ +-----+ + +``` + +Diagram showing the organization of the contents of a data reference box. It consists of a sequence of fields: NDR (Number of data references), followed by DR^1 (Data reference URL), and then DR^NDR (Data reference URL). The fields are represented as boxes with different shading patterns. + +**Figure B.2 – Organization of the contents of a data reference box** + +- NDR:** Number of data references. This field specifies the number of data references, and thus the number of URL boxes contained within this data reference box. +- DR<sup>i</sup>:** Data reference URL. This field contains a data entry URL box as specified in Rec. ITU-T T.800 | ISO/IEC 15444-1 clause I.7.3.2. However, in this context, the location field in the box is not specific to UUID Info boxes. The meaning of the URL is specified in the context of the box that refers to the particular entry in the data reference box. The indices of the elements in the array of DR<sup>i</sup> fields are 1 based; a data reference of 1 in a DR<sup>i</sup> field within a fragment list box or page table box specifies the first data reference URL contained within the data reference box. A data reference value of 0 is a special case that indicates that the reference is to data contained within this file itself. + +**Table B.5 – Format of the contents of the data reference box** + +| Field name | Size (bits) | Value | +|-----------------|-------------|------------| +| NDR | 16 | 0 – 65 535 | +| DR <sup>i</sup> | Variable | Variable | + +### B.1.6 Page collection box (superbox) + +Box type: 'pcol' (0x70636F6C) + +Container: File + +Mandatory: No + +Quantity: At least one + +Location: Anywhere at the file level after the file type box + +NOTE – For efficient access, an optimized file would have the first page collection box located following the data reference box, if it exists, otherwise it would immediately follow the compound image header box. + +A page collection box is a superbox that contains a primary page collection box that is required except when the page collection is the main page collection without a primary page collection as described in clause 5.2.1.2, an optional label box, optional metadata boxes, and a mandatory page table box. A page collection box associates a collection of pages, whose locations are obtained using the page table box with an optional label and optional metadata. + +A JPM file shall have at least one page collection. Every page in a JPM file belongs to what is called its primary page collection. The role of the primary page collection is discussed in clause 5.2.1. + +The type of a page collection box shall be 'pcol' (0x70636F6C). This box contains the following fields: + +![Diagram showing the organization of the contents of a page collection box. It consists of a sequence of fields: PPCLoc (Primary page collection locator box), Label (optional), Metadata (optional), and PTable (Mandatory). The fields are represented as boxes with different shading patterns.](d999c095be67473b31693fab5e475f01_img.jpg) + +``` + + +-----+ +-----+ +-----+ +-----+ + | PPCLoc | | Label | | Metadata | | PTable | + +-----+ +-----+ +-----+ +-----+ + +``` + +Diagram showing the organization of the contents of a page collection box. It consists of a sequence of fields: PPCLoc (Primary page collection locator box), Label (optional), Metadata (optional), and PTable (Mandatory). The fields are represented as boxes with different shading patterns. + +**Figure B.3 – Organization of the contents of a page collection box** + +- PPCLoc:** Primary page collection locator box. This box contains a page collection locator box as specified in clause B.1.6.1. +- Label:** Label box. This optional field may contain a label box as specified in clause B.6.3. This box contains a label associated with the page collection; this box is optional. +- Metadata:** Optional metadata boxes + +PTable: Page table box. This field contains a page table box as specified in clause B.1.6.2. + +##### B.1.6.1 Primary page collection locator box + +Box type: 'ppcl' (0x7070636C) + +Container: Page collection box or page box + +Mandatory: Yes, except in the case of a single page, self-contained JPM file, where it is optional in the page box. + +Quantity: At most one + +Location: Anywhere + +Each page collection box and page box shall contain a primary page collection locator box. A primary page collection locator box contains a set of fields used to locate the "Primary Page Collection" of the page or page collection. The role of the primary page collection is discussed in clause 5.2.1. + +The type of a primary page collection locator box shall be 'ppcl' (0x7070636C). This box contains the following fields: + +![](05d8710f69c476939295486ab1440350_img.jpg) + +PPCDR + +| | | | | +|--------|--------|--|-----| +| PPCOff | PPCLen | | PIx | +|--------|--------|--|-----| + +**Figure B.4 – Organization of the contents of a primary page collection locator box** + +| | | +|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| PPCOff: | Primary page collection offset. This field specifies the offset from the start of the file to the first byte of the primary page collection box to which the page or page collection container belongs. This field is encoded as an 8-byte big endian unsigned integer. | +| PPCLen: | Primary page collection length. This field specifies the length of the primary page collection box for this page. This field is encoded as a 4-byte big endian unsigned integer. | +| PPCDR: | Primary page collection data reference. This field specifies the data file or resource that contains the primary page collection to which the page or page collection container belongs. If the value of this field is zero, then the primary page collection box is contained within this file. If the value is not zero, then the page is contained within the file specified by this index into the data reference box. This field is encoded as a 2-byte big endian unsigned integer. | +| PIx: | Primary page collection page table index. This field specifies an index in the page table of the primary page collection to which the page or page collection container belongs. The entry at the specified index in the page table of the primary page collection shall reference the page or page collection contained in the primary page collection. This field is encoded as a 4-byte big endian unsigned integer. | + +**Table B.6 – Format of the contents of the primary page collection locator box** + +| Field name | Size (bits) | Value | +|------------|-------------|------------------| +| PPCOff | 64 | $0 - (2^{64}-1)$ | +| PPCLen | 32 | $0 - (2^{32}-1)$ | +| PPCDR | 16 | 0 – 65 535 | +| PIx | 32 | $0 - (2^{32}-1)$ | + +#### B.1.6.2 Page table box + +Box type: 'pagt' (0x70616774) + +Container: Page collection box + +Mandatory: Yes + +Quantity: Exactly one in each page collection box + +Location: Anywhere + +The page table box contains the offsets to the page boxes and page collection boxes within the page collection. + +The box data contains the number of entries in the page table. Each entry in the table is a reference to a page box or a page collection box. A flag in each table entry indicates the type of box being referenced. + +The type of a page table box shall be 'pagt' (0x70616774). This box contains the following fields: + +![Diagram showing the organization of the contents of a page table box. The structure starts with a sequence of fields: OFF0, LEN0, DR0, and FL0. This is followed by a shaded area indicating repetition, and ends with fields OFFNE-1, LENNE-1, DRNE-1, and FLNE-1. The fields vary in width, with OFF and LEN being wider than DR and FL.](1142ba0197b158bb198186fe8baccc32_img.jpg) + +Diagram showing the organization of the contents of a page table box. The structure starts with a sequence of fields: OFF0, LEN0, DR0, and FL0. This is followed by a shaded area indicating repetition, and ends with fields OFFNE-1, LENNE-1, DRNE-1, and FLNE-1. The fields vary in width, with OFF and LEN being wider than DR and FL. + +**Figure B.5 – Organization of the contents of a page table box** + +- NE: Number of entries in the page table. The number of {OFF, LEN, DR, FL} tuples in the page table box shall be the same number as the value of the NE field. This field is encoded as a 4-byte big endian unsigned integer. +- OFF<sub>i</sub>: Offset. This field specifies the offset to the first byte of the referenced page or page collection box. The offset is relative to the first byte of the file (the first byte of the length field of the JPEG 2000 signature box). This field is encoded as an 8-byte big endian unsigned integer. +- LEN<sub>i</sub>: Length of the page. This field specifies the length of the page box containing the page. This field is encoded as a 4-byte big endian unsigned integer. +- DR<sub>i</sub>: Data reference. This field specifies the data file or resource that contains this page. If the value of this field is zero, then the page is contained within this file. If the value is not zero, then the page is contained within the file specified by this index into the data reference box. This field is encoded as a 2-byte big endian unsigned integer. +- FL<sub>i</sub>: Flag. This field indicates the type of entry. This field is encoded as a 1-byte unsigned integer. Legal values of this field are as follows: + +**Table B.7 – Legal FL values** + +| Values (bits)<br>MSB    LSB | Meaning | +|-----------------------------|---------------------------------------------------------------| +| xxxx x001 | Offset to page box. | +| xxxx x011 | Offset to page box containing thumbnail. | +| xxxx x000 | Offset to non-auxiliary page collection box. | +| xxxx x100 | Offset to auxiliary page collection box. | +| xxxx 0xxx | Offset to page or page collection box containing no metadata. | +| xxxx 1xxx | Offset to page or page collection box containing metadata. | +| other values | Reserved for ISO use. | + +**Table B.8 – Format of the contents of the page table box** + +| Parameter | Size (bits) | Value | +|------------------|-------------|-------------------| +| NE | 32 | $1 - (2^{32}-1)$ | +| OFF <sub>i</sub> | 64 | $12 - (2^{64}-1)$ | +| LEN <sub>i</sub> | 32 | $0 - (2^{32}-1)$ | +| DR <sub>i</sub> | 16 | 0 – 65 535 | +| FL <sub>i</sub> | 8 | see Table B.7 | + +### **B.1.7 Shared-data entry box** + +- Box type: 'sdat' (0x73646174) +- Container: File +- Mandatory: No +- Quantity: Any number +- Location: Anywhere after the compound image header box + +The shared-data entry box contains an identifier field and shared data, which is a box that can occur multiple times in the file. An example of shared data is a JP2 header box. Rather than replicate that box each time it is used, a reference to the box is used. The reference is contained in a shared-data reference box. When this reference is encountered, it is + +replaced by the shared data box from the shared-data entry box with the same identifier as used in the shared-data reference box. + +The type of a shared-data reference box shall be 'sdat' (0x73646174). This box contains the following fields: + +![Diagram of a shared-data entry box structure. It consists of a small box labeled 'ID' followed by a larger shaded box labeled 'SharedData'.](78ff716475b2f65bf01c3a4d02d89fc4_img.jpg) + +SharedData + +Diagram of a shared-data entry box structure. It consists of a small box labeled 'ID' followed by a larger shaded box labeled 'SharedData'. + +**Figure B.6 – Organization of the contents of a shared-data entry box** + +- ID: Identifier. This field specifies a number that is the unique identifier for the shared data contained in the box. It is encoded as a 2-byte unsigned integer. +- SharedData: This field contains the box that can be used multiple places in the file. + +**Table B.9 – Format of the contents of a shared-data entry box** + +| Field name | Size (bits) | Value | +|-------------|-------------|------------| +| ID | 16 | 0 – 65 535 | +| Shared Data | Variable | Variable | + +### B.1.8 Shared-data reference box + +Box type: 'sref' (0x73726566) + +Container: Not restricted + +Mandatory: No + +Quantity: Any number + +Location: Anywhere after the shared-data entry box with the same ID + +The shared-data reference box contains a reference to the shared data that is to be used or inserted at the point in the file where the shared-data reference box occurs. When a shared-data reference box is encountered, it is replaced by the shared data from the shared-data entry box with the ID value. + +Any offsets in the file are understood to apply before any substitution implied by the shared-data reference. + +The type of a shared-data reference box shall be 'sref' (0x73726566). This box contains the following field: + +![Diagram of a shared-data reference box structure. It consists of a single box labeled 'ID'.](2c532a9bb51e081048d718316f509294_img.jpg) + +Diagram of a shared-data reference box structure. It consists of a single box labeled 'ID'. + +**Figure B.7 – Organization of the contents of a shared-data reference box** + +- ID: Identifier. This field specifies a number that is the unique identifier of the shared data to be used. It is encoded as a 2-byte unsigned integer. It is a reference to the shared data in the shared-data entry box with the same ID field value. + +**Table B.10 – Format of the contents of the shared-data reference box** + +| Field name | Size (bits) | Value | +|------------|-------------|------------| +| ID | 16 | 0 – 65 535 | + +## B.2 Page level boxes + +### B.2.1 Page box (superbox) + +Box type: 'page' (0x70616765) + +Container: File + +Mandatory: Yes + +Quantity: At least one + +Location: Anywhere after the compound image header box + +The page box is a superbox that contains information about the page on which the layout objects are rendered, followed by the layout objects that make up the page contents. + +The type of a page box shall be 'page' (0x70616765). This box contains the following fields: + +![Diagram showing the organization of the contents of a page box. It consists of a sequence of boxes: PHDR, PPCLoc, Res, BCLR, Metadata, Label, Lobj0, and LobjN-1. The boxes are arranged horizontally, with PHDR on the left and LobjN-1 on the right. The boxes for Res, BCLR, Metadata, and Label are shaded with diagonal lines. The boxes for Lobj0 and LobjN-1 are also shaded, but with a different pattern. The boxes for PPCLoc and Lobj0 are white.](6629e8a87e7552e2454b7c3e9f6d73a0_img.jpg) + +| | | | | | | | | +|------|--------|-----|------|----------|-------|-------------------|---------------------| +| | PPCLoc | Res | BCLR | Metadata | Label | | | +| PHDR | | | | | | Lobj <sub>0</sub> | Lobj <sub>N-1</sub> | + +Diagram showing the organization of the contents of a page box. It consists of a sequence of boxes: PHDR, PPCLoc, Res, BCLR, Metadata, Label, Lobj0, and LobjN-1. The boxes are arranged horizontally, with PHDR on the left and LobjN-1 on the right. The boxes for Res, BCLR, Metadata, and Label are shaded with diagonal lines. The boxes for Lobj0 and LobjN-1 are also shaded, but with a different pattern. The boxes for PPCLoc and Lobj0 are white. + +Figure B.8 – Organization of the contents of a page box + +- PHDR: Page header box. This field contains a layout object header box as specified in clause B.2.1.1. +- PPCLoc: Primary page collection locator box. This box contains a page collection locator box as specified in clause B.1.6.1. This is mandatory except in the case of a single page, self-contained JPM file, where it is optional. +- Res: Resolution box. This optional field may contain a resolution box as specified in Rec. ITU-T T.800 | ISO/IEC 15444-1 clause I.5.3.7. This box gives the resolution of a page grid unit. Together with the page height and width in the page header box, it gives the physical size of the page. +- BCLR: Base colour box. This optional field may contain a base colour box as specified in clause B.6.1. The base colour box occurs in a page box when the value of the PColour field in the page header box is 255. Within a page box it specifies the colour that is applied prior to rendering any objects onto the page. +- Metadata: Optional metadata boxes. +- Label: Label box. This field may contain a label box as specified in clause B.6.3. This box contains a label associated with the page; this box is optional. +- Lobj<sup>i</sup>: Layout object box i, where i = 0, NObj–1; the layout object box is specified in clause B.3.1. NObj is the number of layout objects on this page and is specified in the page header box contained within this box. + +#### B.2.1.1 Page Header box + +- Box type: 'phdr'(0x70686472) +- Container: Page box +- Mandatory: Yes +- Quantity: Exactly one +- Location: First box in a page box + +A page header box specifies a number of layout objects on the page and describes the height, width, orientation and colour of the page, i.e., the surface on which the layout objects are rendered. + +The type of a page header box shall be 'phdr' (0x70686472). This box contains the following fields: + +![Diagram showing the organization of the contents of a page header box. It consists of a sequence of boxes: NObj, PHeight, PWidth, OR, and PColour. The boxes are arranged horizontally, with NObj on the left and PColour on the right. The boxes for NObj, PHeight, PWidth, and OR are white, and the box for PColour is shaded with diagonal lines.](257c8341b41f1f4a287f27d33227974c_img.jpg) + +| | | | | | +|------|---------|--------|----|---------| +| | | | | PColour | +| NObj | PHeight | PWidth | OR | | + +Diagram showing the organization of the contents of a page header box. It consists of a sequence of boxes: NObj, PHeight, PWidth, OR, and PColour. The boxes are arranged horizontally, with NObj on the left and PColour on the right. The boxes for NObj, PHeight, PWidth, and OR are white, and the box for PColour is shaded with diagonal lines. + +Figure B.9 – Organization of the contents of a page header box + +- NObj: Number of layout objects on this page. This value is stored as a 2-byte big endian unsigned integer. +- PHeight: Page height. This field indicates the height, in page grid units and before any rotation, of the region onto which the layout objects on this page are to be rendered. This value is stored as a 4-byte big endian unsigned integer. +- PWidth: Page width. This field indicates the width, in page grid units and before any rotation, of the region onto which the layout objects on this page are to be rendered. This value is stored as a 4-byte big endian unsigned integer. +- OR: Page orientation. This field indicates the orientation of the page. The value is a 2-byte big endian unsigned integer. Values defined in this specification are: + +Table B.11 – Legal OR values + +| Value | Meaning | +|--------------|-------------------------------------------------| +| 0 | Orientation not specified | +| 1 | Rotate 0° clockwise for a right-reading image | +| 2 | Rotate 90° clockwise for a right-reading image | +| 3 | Rotate 180° clockwise for a right-reading image | +| 4 | Rotate 270° clockwise for a right-reading image | +| other values | All other values reserved | + +PColour: Page colour. This field indicates whether the page is transparent, in which case the layout objects are imaged onto whatever exists within the boundaries of the page, or whether the page has a colour, in which case, the page colour is applied everywhere within the boundaries of the page and then the layout objects are imaged onto the page. The value is a 2-byte big endian unsigned integer. Values defined in this specification are: + +Table B.12 – Legal Pcolour values + +| Value | Meaning | +|--------------|------------------------------------------------------------| +| 0 | Page is transparent | +| 1 | Page is white | +| 2 | Page is black | +| 255 | Page colour is specified in base colour box (clause B.6.1) | +| other values | All other values reserved | + +Table B.13 – Format of the contents of a page header box + +| Field name | Size (bits) | Value | +|------------|-------------|------------------| +| NLobj | 16 | 0 – 65 535 | +| PHeight | 32 | $1 - (2^{32}-1)$ | +| PWidth | 32 | $1 - (2^{32}-1)$ | +| OR | 16 | see Table B.11 | +| PColour | 16 | see Table B.12 | + +## B.3 Layout object level boxes + +### B.3.1 Layout object box (superbox) + +Box type: 'lobj' (0x6C6F626A) +Container: Page box +Mandatory: Yes +Quantity: Any number +Location: Anywhere after page header box + +A layout object box contains the information needed to position and composite an image and optional mask on a page. It contains the layout object header box, optional metadata, and an object header box (for image data) and an optional object header box (for mask data). + +The type of a layout object box shall be 'lobj' (0x6C6F626A). This box contains the following fields: + +![Diagram showing the organization of the contents of a layout object box. It is a horizontal sequence of boxes: LHDR, Metadata, Label, OBJ0, and OBJ1. Metadata and Label boxes have dashed borders, indicating they are optional. OBJ0 and OBJ1 are adjacent in a single block.](00942e7d6db56fd4fbd5f45bdbad7fdb_img.jpg) + +``` + +graph LR + LHDR[LHDR] --- Metadata[Metadata] + Metadata -.- Label[Label] + Label -.- OBJ0[OBJ0] + OBJ0 --- OBJ1[OBJ1] + style Metadata stroke-dasharray: 5 5 + style Label stroke-dasharray: 5 5 + +``` + +Diagram showing the organization of the contents of a layout object box. It is a horizontal sequence of boxes: LHDR, Metadata, Label, OBJ0, and OBJ1. Metadata and Label boxes have dashed borders, indicating they are optional. OBJ0 and OBJ1 are adjacent in a single block. + +Figure B.10 – Organization of the contents of a layout object box + +LHDR: Layout object header box. This field contains a layout object header box as specified in clause B.3.1.1. + +| | | +|--------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------| +| Metadata: | Optional metadata boxes. | +| Label: | Label box. This field may contain a label box as specified in clause B.6.3. This box contains a label associated with the page; this box is optional. | +| OBJ <sup>0</sup> : | Object box; the first object box. This field contains an object box as specified in clause B.4.1. | +| OBJ <sup>1</sup> : | Object box; the second object box. This field contains an object box as specified in clause B.4.1; this box is optional. | + +#### B.3.1.1 Layout object header box + +Box type: 'lhdr' (0x6C686472) + +Container: Layout object box + +Mandatory: Yes + +Quantity: Exactly one + +Location: First box in layout object box + +This box gives the layout object ID (unique within a page), height (in page grid units), width (in page grid units), offset with respect to the page and style of the layout object. + +The type of a layout object header box shall be 'lhdr' (0x6C686472). This box contains the following fields: + +![](eb1a67ebd688e354edaacb7ec2abf5ad_img.jpg) + +| | | | | | | +|--------|---------|--------|-------|-------|--| +| LObjID | | | | Style | | +| | LHeight | LWidth | LVoff | LHoff | | + +**Figure B.11 – Organization of the contents of a layout object header box** + +| | | +|----------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| LObjID: | Layout object identifier. Each layout object in a given page box has a unique LObjID value and layout object boxes within a page box must occur in order of increasing LObjID value. If the page does not contain a page thumbnail then the LObjID values range from 1 to NObj, with NObj defined in the page header box within the page box. If a page does contain a page thumbnail then the LObjID values for the contained layout object boxes range from 0 to NObj – 1, with a LObjID value of 0 identifying the page thumbnail object (see 5.2.4). This value is stored as a 2-byte big endian unsigned integer. | +| LHeight: | Layout object height. This field indicates the height, in page grid units, of the layout object before any page rotation. This value is stored as a 4-byte big endian unsigned integer. | +| LWidth: | Layout object width. This field indicates the width, in page grid units, of the layout object before any page rotation. This value is stored as a 4-byte big endian unsigned integer. | +| LVoff: | Layout vertical offset. This field indicates the vertical starting offset in page grid units of the layout object. This value is stored as a 4-byte big endian unsigned integer. | +| LHoff: | Layout horizontal offset. This field indicates the horizontal starting offset in page grid units of the layout object. This value is stored as a 4-byte big endian unsigned integer. | +| Style: | Layout object style. This field indicates the style of the layout object. A layout object can consist of either a single image or an image and a mask pair. The image and mask of a layout object may consist of two separate objects or the mask may be the last component of the image object. The value is a 1-byte unsigned integer. Values defined in this specification are: | + +**Table B.14 – Legal style values** + +| Value | Meaning | +|--------------|----------------------------------------------------| +| 0 | Separate objects for image and mask components. | +| 1 | Single object for image and mask components. | +| 2 | Single object for image components only (no mask). | +| 3 | Single object for mask components only (no image). | +| 255 | User specified layout object. | +| other values | All other values reserved | + +**Table B.15 – Format of the contents of the Layout Object Header box** + +| Field name | Size (bits) | Value | +|------------|-------------|--------------------------| +| LObjID | 16 | 0 – 65 535 | +| LHeight | 32 | 0 – (2 <sup>32</sup> –1) | +| LWidth | 32 | 0 – (2 <sup>32</sup> –1) | +| LVoff | 32 | 0 – (2 <sup>32</sup> –1) | +| LHoff | 32 | 0 – (2 <sup>32</sup> –1) | +| Style | 8 | see Table B.14 | + +## **B.4 Object level boxes** + +### **B.4.1 Object box (superbox)** + +Box type: 'objc' (0x6F626A63) + +Container: Layout object box + +Mandatory: Yes + +Quantity: At least one in each layout object box + +Location: Anywhere after the layout object header box + +The object box is a superbox that contains information about the objects. + +The type of an object box shall be 'objc' (0x6F626A63). This box contains the following fields: + +![Diagram showing the organization of the contents of an object box. It is a horizontal sequence of boxes: OHDR (Object Header Box), BCLR (Optional base colour box), Metadata (Optional metadata box), Label (Optional label box), Scale (Optional object scale box), and JP2HDR (Optional JP2 header box). The OHDR box is solid black, while the others are hatched.](90aa518591dfa9a78f61c31296f9b158_img.jpg) + +``` + + +-----+-----+-----+-----+-----+ + | OHDR | BCLR | Metadata | Label | Scale | JP2HDR | + +-----+-----+-----+-----+-----+ + +``` + +Diagram showing the organization of the contents of an object box. It is a horizontal sequence of boxes: OHDR (Object Header Box), BCLR (Optional base colour box), Metadata (Optional metadata box), Label (Optional label box), Scale (Optional object scale box), and JP2HDR (Optional JP2 header box). The OHDR box is solid black, while the others are hatched. + +**Figure B.12 – Organization of the contents of an object box** + +- OHDR: Object header box. This field contains an object header box as specified in clause B.4.1.1. +- BCLR: Optional base colour box. This optional field may contain a base colour box as specified in clause B.6.1. The base colour box within the object box is used to specify the values to be used within the boundaries of the layout object in areas where no image is defined. This includes the situation where the object NoCodestream field is 1 and the situation when the scaled and positioned object image is smaller than the layout object. +- Metadata: Optional metadata box. +- Label: Optional label box. This optional field may contain a label box as specified in clause B.6.3. This box contains a label associated with the page. +- Scale: Optional object scale box. This optional field may contain an object scale box as specified in clause B.4.1.2. It specifies the scaling for the object before applying it to the page. +- JP2HDR: Optional JP2 header box. Always exists if the NoCodestream field in the object header box is 0. This optional field may contain a JP2 header box as specified in clause B.4.1.3. + +#### **B.4.1.1 Object header box** + +Box type: 'ohdr' (0x6F686472) + +Container: Object box + +Mandatory: Yes + +Quantity: Exactly one + +Location: First box in the object box + +This box contains fields that describe general properties of the object. The fields are: ObjType (if this object is used only for a mask the type is '0', if only for the image the type is '1', if for the image and mask the value is '2'), NoCodestream (if the value of this parameter is '1', then this object is coloured by a unique colour specified by the base colour box in the object box), OHoff (horizontal offset in page grid units), OVoff (vertical offset in page grid resolution), and a reference to the codestream data for the object – either an offset to and the length of a fragment table or contiguous codestream box. + +The type of an object header box shall be 'ohdr' (0x6F686472). This box contains the following fields: + +![Diagram showing the organization of the contents of an object header box. It is a 16-byte structure. The first byte is ObjType. The second byte is NoCdstrm. The next four bytes are OVoff. The next four bytes are OHoff. The next four bytes are OFF. The next four bytes are LEN. The last two bytes are DR.](1ab49904e6a60be337d5b75cb7cc8ab7_img.jpg) + +The diagram illustrates the layout of an object header box. It is a horizontal sequence of 16 bytes. The fields are: ObjType (1 byte), NoCdstrm (1 byte), OVoff (4 bytes), OHoff (4 bytes), OFF (4 bytes), LEN (4 bytes), and DR (2 bytes). Arrows point from the labels to their respective fields in the box. + +Diagram showing the organization of the contents of an object header box. It is a 16-byte structure. The first byte is ObjType. The second byte is NoCdstrm. The next four bytes are OVoff. The next four bytes are OHoff. The next four bytes are OFF. The next four bytes are LEN. The last two bytes are DR. + +Figure B.13 – Organization of the contents of an object header box + +**ObjType:** Object type. This identifies whether the object is a mask object or an image object in the layout object. The value is a 1-byte big endian unsigned integer. Values defined in this specification are: + +Table B.16 – Legal ObjType values + +| Value | Meaning | +|--------------|-----------------------------------------------------------| +| 0 | The object contains the mask of a layout object | +| 1 | The object contains the image of a layout object | +| 2 | The object contains the image and mask of a layout object | +| other values | All other values reserved | + +**NoCdstrm:** Identifies whether or not the object contains a compressed codestream. If the object does not contain a codestream, then there is no image for this object and an "image" with a single uniform colour value as specified in the base colour box is used as the object. The value is a 1-byte big endian unsigned integer. Values defined in this specification are: + +Table B.17 – Legal NoCdstrm values + +| Value | Meaning | +|--------------|------------------------------------------| +| 0 | The object contains a codestream | +| 1 | The object does not contain a codestream | +| other values | All other values reserved | + +**OVoff:** Vertical offset in the scaled object; the vertical offset into the scaled object in page grid units. This field is a 4-byte big endian unsigned integer. If the NoCodestream field has a value of 1, then this field is ignored. + +**OHoff:** Horizontal offset in the scaled object; the horizontal offset into the scaled object in page grid units. This field is a 4-byte big endian unsigned integer. If the NoCodestream field has a value of 1, then this field is ignored. + +**OFF:** Offset. This field specifies the file offset to the start of the contiguous codestream or fragment table box that is associated with this object's image. The contiguous codestream or fragment table box is used to access the actual codestream. The offset is relative to the first byte of the file. This field is encoded as an 8-byte big endian unsigned integer. If the NoCodestream field has a value of 1, then this field is ignored. + +**LEN:** Length of the contiguous codestream or fragment table box. This value includes only the actual data and not any headers of an encapsulating box. This field is encoded as a 4-byte big endian unsigned integer. If the value is 0, then the length of the contiguous codestream or fragment table box is not known. If the NoCodestream field has a value of 1, then this field is ignored. + +**DR:** Data reference. This field specifies the data file or resource that contains the fragment table box. If the value of this field is zero, then the fragment is contained within this file or the data is contained in a contiguous codestream box within the file. If the value is not zero, then the fragment table box is contained within the file specified by this index into the data reference box. This field is encoded as a 2-byte big endian unsigned integer. If the NoCodestream field has a value of 1, then this field is ignored. + +**Table B.18 – Format of the contents of the object header box** + +| Field name | Size (bits) | Value | +|------------|-------------|------------------| +| ObjType | 8 | see Table B.16 | +| NoCdstrm | 8 | see Table B.17 | +| OOff | 32 | $0 - (2^{32}-1)$ | +| OHoff | 32 | $0 - (2^{32}-1)$ | +| OFF | 64 | $0 - (2^{64}-1)$ | +| LEN | 32 | $0 - (2^{32}-1)$ | +| DR | 16 | $0 - 65\ 535$ | + +#### **B.4.1.2 Object scale box** + +Box type: 'scal' (0x7363616C) + +Container: Object box + +Mandatory: No + +Quantity: At most one in each object box + +Location: Anywhere after the object header box + +The object scale box optionally exists when the NoCodestream field of the object header box in the container object box is 0. If an object scale box does not exist within an object box then the vertical and horizontal scaling ratios are assumed to be 1, i.e., no scaling. This box describes the scaling required to transform from object units to page grid units. This scaling must be used before applying the object to the page. + +The vertical scaling is by the ratio $\frac{VRN}{VRD}$ , and the horizontal scaling is by the ratio $\frac{HRN}{HRD}$ . See clause 5.2.3 for a full description of the scaling operation. + +The type of an object scale box shall be 'scal' (0x7363616C). This box contains the following fields: + +![](ddd86d7df6cf14d68c0faf111c1e8fae_img.jpg) + +| | | | | +|-----|-----|-----|-----| +| VRN | VRD | HRN | VRD | +|-----|-----|-----|-----| + +**Figure B.14 – Organization of the contents of an object header box** + +- VRN: Vertical scaling numerator; this parameter is encoded as a 2-byte big endian unsigned integer. +- VRD: Vertical scaling denominator; this parameter is encoded as a 2-byte big endian unsigned integer. +- HRN: Horizontal scaling numerator; this parameter is encoded as a 2-byte big endian unsigned integer. +- HRD: Horizontal scaling denominator; this parameter is encoded as a 2-byte big endian unsigned integer. + +**Table B.19 – Format of the contents of the object scale box** + +| Field name | Size (bits) | Value | +|------------|-------------|---------------| +| VRN | 16 | $1 - 65\ 535$ | +| VRD | 16 | $1 - 65\ 535$ | +| HRN | 16 | $1 - 65\ 535$ | +| HRD | 16 | $1 - 65\ 535$ | + +#### **B.4.1.3 JP2 header box (superbox) in object box** + +Box type: 'jp2h' (0x6A70 3268') + +Container: Object box + +Mandatory: No + +Quantity: At most one; always exists if the NoCodestream field in the object header box is 0. + +Location: Immediately after the object scale box if present, anywhere after the object header box otherwise. + +The format and structure of the JP2 header box is defined in clause B.6.2. + +A JP2 header box exists within an object box when the NoCodestream field of the object header box in the container object box is 0. Within an object box of a JPM file, there shall be one and only one JP2 header box. + +## B.5 JP2 codestream element boxes + +### B.5.1 Fragment table box (superbox) + +Box type: 'ftbl' (0x6674626C) + +Container: File + +Mandatory: No + +Quantity: Any number + +Location: Anywhere after file type box + +A fragment table box specifies the location of one of the codestreams in a JPM file. A file may contain zero or more fragment table boxes. For the purpose of numbering codestreams, the fragment table box shall be considered equivalent to a contiguous codestream box. Fragment table boxes shall be found only at the top level of the file; they shall not be found within a superbox. + +The type of a fragment table box shall be 'ftbl' (0x6674626C). This box contains the following field: + +flst: Fragment List. This field contains a fragment list box as specified in clause B.5.2. + +![Diagram showing the organization of the contents of a fragment table box. It consists of a single box labeled 'flst'.](c8fcc1ae5d86caaae5607b58d16be8e4_img.jpg) + +``` + +graph TD + flst[flst] + +``` + +Diagram showing the organization of the contents of a fragment table box. It consists of a single box labeled 'flst'. + +Figure B.15 – Organization of the contents of a fragment table box + +#### B.5.1.1 Fragment list box + +Box type: 'flst' (0x666C7374) + +Container: Cross-reference box and fragment table box + +Mandatory: Yes + +Quantity: Exactly one + +Location: Anywhere + +The fragment list box specifies the location, length and order of each of the fragments that, once combined, form a valid and complete data stream. Depending on which box contains this particular fragment list box, the data stream forms either a codestream (if the fragment list box is contained in a fragment table box) or shared header or metadata (if the fragment list box is contained in a cross-reference box). + +If this fragment list box is contained within a fragment table box (and thus specifies the location of a codestream), then the first offset in the fragment list shall point directly to the first byte of codestream data; it shall not point to the header of the box containing the first codestream fragment. + +If this fragment list box is contained within a cross-reference box (and thus specifies the location of shared header or metadata), then the first offset in the fragment list shall point to the first byte of the contents of the referenced box; it shall not point to the header of the referenced box. However, if the referenced box is a superbox, then the offset of the first fragment does point to the box header of the first box contained within the superbox. + +For all other offsets in the fragment list box, the offsets shall point directly to the first byte of the fragment data and not to the header of the box that contains that fragment. + +The type of a fragment list box shall be 'flst' (0x666C7374). This box contains the following fields: + +![Diagram showing the organization of the contents of a fragment list box. The box is divided into several fields: NF, OFF0, LEN0, DR0, OFFNF-1, LENNF-1, and DRNF-1.](94746ca6aec95d1d643a61a48cd1d24b_img.jpg) + +``` + +graph LR + NF[NF] --- OFF0[OFF0] + OFF0 --- LEN0[LEN0] + LEN0 --- DR0[DR0] + DR0 --- OFFNF-1[OFFNF-1] + OFFNF-1 --- LENNF-1[LENNF-1] + LENNF-1 --- DRNF-1[DRNF-1] + +``` + +Diagram showing the organization of the contents of a fragment list box. The box is divided into several fields: NF, OFF0, LEN0, DR0, OFFNF-1, LENNF-1, and DRNF-1. + +Figure B.16 – Organization of the contents of a fragment list box + +- NF: Number of fragments. This field specifies the number of fragments used to contain the data stream. The number of {OFF, LEN, DR} tuples in the fragment list box shall be the same number as the value of the NF field. +- OFF<sup>i</sup>: Offset. This field specifies the offset to the start of the fragment in the file. The offset is relative to the first byte of the file (the first byte of the length field of the JPEG 2000 signature box). This field is encoded as an 8-byte big endian unsigned integer. Only the first fragment in a fragment list contained within a cross-reference box shall point to the first byte of a box header. +- LEN<sup>i</sup>: Length of fragment. This field specifies the length of the fragment. This value includes only the actual data and not any headers of an encapsulating box. This field is encoded as a 4-byte big endian unsigned integer. +- DR<sup>i</sup>: Data reference. This field specifies the data file or resource that contains this fragment. If the value of this field is zero, then the fragment is contained within this file. If the value is not zero, then the fragment is contained within the file specified by this index into the data reference box. This field is encoded as a 2-byte big endian unsigned integer. + +**Table B.20 – Format of the contents of the fragment list box** + +| Parameter | Size (bits) | Value | +|------------------|-------------|---------------------------| +| NF | 16 | 0 – 65 535 | +| OFF <sup>i</sup> | 64 | 12 – (2 <sup>64</sup> –1) | +| LEN <sup>i</sup> | 32 | 0 – (2 <sup>32</sup> –1) | +| DR <sup>i</sup> | 16 | 0 – 65535 | + +### **B.5.2 Media data box** + +Box type: 'mdat' (0x6D646174) + +Container: File + +Mandatory: No + +Quantity: Any number + +Location: Anywhere after the file type box + +The media data box contains fragments of the JPEG 2000 codestream or other media data. In any case, there shall be other boxes in the file that specify the meaning of the data within the media data box. Applications should not access media data boxes directly, but instead use the fragment table to determine what parts of which media data boxes represent a valid JPEG 2000 codestream or other media stream. + +The type of a media data box shall be 'mdat' (0x6D646174). The contents of a media data box in general are not defined by this International Standard. + +### **B.5.3 Contiguous codestream box** + +Box type: 'jp2c' (0x6A703263) + +Container: File + +Mandatory: No + +Quantity: Any number + +Location: Anywhere after the file type box + +The format and structure of the contiguous codestream box is defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 clause I.5.4. + +## **B.6 General/common boxes** + +### **B.6.1 Base colour box (superbox)** + +Box type: 'bclr'(0x62636C72) + +Container: Page box or object box + +Mandatory: No + +Quantity: At most one + +Location: Anywhere in the page box after the page header box or in the object box after the object header box. + +A base colour box is a superbox that specifies a base colour for an image object or a page. + +The type of a base colour box shall be 'bclr' (0x62636C72). The data field of the box is: + +![Diagram showing the organization of the contents of a base colour box. It consists of three adjacent rectangular boxes labeled BCVL, COLR, and BPCC from left to right.](b44f89b176c971c7dd264c07bfef2c2a_img.jpg) + +Diagram showing the organization of the contents of a base colour box. It consists of three adjacent rectangular boxes labeled BCVL, COLR, and BPCC from left to right. + +**Figure B.17 – Organization of the contents of a base colour box** + +- BCVL:** Base colour value box. This box specifies the individual component values for the base colour together with some additional information. +- COLR:** Colour specification box. This box specifies the colourspace of the base colour. Its structure is specified in clause B.6.2.2. +- BPCC:** Bits per component box. This box specifies the bit depth of each component in the image. This field contains a bits per component box as specified in Rec. ITU-T T.800 | ISO/IEC 15444-1 clause 1.5.3.2 of this International Standard. If the bit depth of all components in the image is the same (in both sign and precision), then this box shall not be found. Otherwise, this box specifies the bit depth of each individual component. + +#### B.6.1.1 Base colour value box + +Box type: 'bcvl'(0x6263766C) + +Container: Base colour box + +Mandatory: Yes + +Quantity: Exactly one + +Location: Anywhere + +A base colour value box specifies the individual component values for the base colour together with information regarding the bit depth for the components. + +The type of a base colour box shall be 'bcvl' (0x6263766C). The box contains the following fields: + +![Diagram showing the organization of the contents of a base colour value box. It consists of four adjacent rectangular boxes. The first box is labeled 'NC'. The second box is labeled 'BPC'. The third box is shaded and labeled 'Value^0'. The fourth box is labeled 'Value^{NC-1}'.](fbce213427570f177cd310adf8b7a604_img.jpg) + +Diagram showing the organization of the contents of a base colour value box. It consists of four adjacent rectangular boxes. The first box is labeled 'NC'. The second box is labeled 'BPC'. The third box is shaded and labeled 'Value^0'. The fourth box is labeled 'Value^{NC-1}'. + +**Figure B.18 – Organization of the contents of a base colour value box** + +- NC:** Number of components. This parameter specifies the number of components in the codestream and is stored as a 2-byte big endian unsigned integer. +- BPC:** Bits per component. This parameter specifies the bit depth of the components in the image, minus 1, and is stored as a 1-byte field. If the bit depth and the sign are the same for all components, then this parameter specifies that bit depth. If the components vary in bit depth and/or sign, then the value of this field shall be 255 and the base colour box shall also contain a bits per component box defining the bit depth of each component (as defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 clause 1.5.3.2). The low 7-bits of the value indicate the bit depth of the components. The high-bit indicates whether the components are signed or unsigned. If the high-bit is 1, then the components contain signed values. If the high-bit is 0, then the components contain unsigned values. Legal values of this field are given in Table B.22: + +Table B.21 – Legal BPC values + +| Values (bits)<br>MSB  LSB | Meaning | +|---------------------------|---------------------------------------------------------------------------------------------| +| x000 0000 –<br>x000 1111 | Component bit depth = value + 1. From 1 to 16 bits (counting the sign bit, if appropriate). | +| 0xxx xxxx | Components are unsigned values. | +| 1xxx xxxx | Components are signed values. | +| 1111 1111 | Components vary in bit depth and/or sign. | +| other values | Reserved for ISO use | + +Value<sup>1</sup>: The value of the individual base colour component. Each value is represented by a 2-byte big endian signed integer. + +Table B.22 – Format of the contents of the base colour value box + +| Field name | Size (bits) | Value | +|--------------------|-------------|----------------| +| NC | 16 | 1 – 16 384 | +| BPC | 8 | see Table B.21 | +| Value <sub>i</sub> | 16 | 0 – 65 535 | +| DR <sub>i</sub> | 16 | 0 – 65 535 | + +### B.6.2 JP2 header box (superbox) + +Box type: 'jp2h' (0x6A703268) + +Location: File or object box + +The format and structure of the JP2 header box is identical to that defined in Rec. ITU-T T.800 | ISO/IEC 15444- 1 clause I.5.3. + +A JP2 header box in a JPM file may be found immediately after the file type box, clause B.1.2, or within an object box, clause B.4.1. + +This box contains several boxes. Other boxes may be defined in other standards and may be ignored by conforming readers. Those boxes contained within the JP2 header box that are defined within this International Standard are as follows: + +![Diagram showing the organization of the contents of a JP2 header box. It starts with a box labeled 'ihdr', followed by an ellipsis, then a box labeled 'bpcc', followed by another ellipsis, then a box labeled 'colr0', followed by a box labeled 'colr^{n-1}', followed by an ellipsis, then a box labeled 'pclr', followed by an ellipsis, then a box labeled 'cmap', followed by an ellipsis, then a box labeled 'cdef', followed by an ellipsis, and finally a box labeled 'res'.](f56ab8d50c10444a7043b7e30880cd0a_img.jpg) + +The diagram illustrates the sequence of boxes within a JP2 header box. It begins with the 'ihdr' box, followed by an ellipsis indicating optional boxes. Then comes the 'bpcc' box, followed by another ellipsis. This is followed by a series of 'colr' boxes, specifically 'colr<sup>0</sup>' and 'colr<sup>n-1</sup>', with an ellipsis between them. After the 'colr' boxes, there is an ellipsis, followed by the 'pclr' box, another ellipsis, the 'cmap' box, an ellipsis, the 'cdef' box, an ellipsis, and finally the 'res' box. + +Diagram showing the organization of the contents of a JP2 header box. It starts with a box labeled 'ihdr', followed by an ellipsis, then a box labeled 'bpcc', followed by another ellipsis, then a box labeled 'colr0', followed by a box labeled 'colr^{n-1}', followed by an ellipsis, then a box labeled 'pclr', followed by an ellipsis, then a box labeled 'cmap', followed by an ellipsis, then a box labeled 'cdef', followed by an ellipsis, and finally a box labeled 'res'. + +Figure B.19 – Organization of the contents of a JP2 header box + +- ihdr: Image header box. This box specifies information about the object, such as its height and width. Its structure is specified in clause B.6.2.1. This box shall be the first box in the JP2 header box. +- bpcc: Bits per component box. This box specifies the bit depth of each component in the image. This field contains a bits per component box as specified in Rec. ITU-T T.800 | ISO/IEC 15444-1 clause I.5.3.2. If the bit depth of all components in the image is the same (in both sign and precision), then this box shall not be found. Otherwise, this box specifies the bit depth of each individual component. This box may be found anywhere in the JP2 header box provided that it comes after the image header box. +- colr<sub>i</sub>: Colour specification box. This box specifies the colourspace of the decompressed image. Its structure is specified in clause B.6.2.2. This box may be found anywhere in the JP2 header box provided that it comes after the image header box. +- pclr: Palette box. This box defines the palette to be used to create multiple components from a single component. This field contains a palette box as specified in Rec. ITU-T T.800 | ISO/IEC 15444-1 clause I.5.3.4. This box may be found anywhere in the JP2 header box provided that it comes after the image header box. + +| | | +|-------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| cmap: | Component mapping box. This field contains a component mapping box as specified in Rec. ITU-T T.800 ISO/IEC 15444-1 clause I.5.3.5. This box may be found anywhere in the JP2 header box provided that it comes after the image header box. | +| cdef: | Channel definition box. This field contains a channel definition box as specified in Rec. ITU-T T.800 ISO/IEC 15444-1 clause I.5.3.6. This box may be found anywhere in the JP2 header box provided that it comes after the image header box. | +| res: | Resolution box. This box is optional and may be used to specify the capture and/or default display grid resolutions of the object. This field may contain a resolution box as specified in Rec. ITU-T T.800 ISO/IEC 15444-1 clause I.5.3.7. This box may be found anywhere in the JP2 header box provided that it comes after the image header box. | + +The JP2 header box is a superbox that in a JPM file shall contain an image header box and a colour specification box, and may contain a bits per component box, a palette box, a component mapping box, a channel definition box and a resolution box. + +#### B.6.2.1 Image header box + +Box type: 'ihdr' (0x69686472) + +Container: JP2 header box + +Mandatory: Yes + +Quantity: Exactly one + +Location: First box in JP2 header box + +This box contains fixed length generic information about the object, such as the image size and number of components. The contents of the JP2 header box shall start with an image header box. Objects that contain contradictory information between the image header box and the object codestream are not conforming files. + +The type of the image header box shall be 'ihdr' (0x69686472) and the contents of the box shall have the following format: + +![Diagram showing the organization of the contents of an image header box. It consists of fields for HEIGHT, WIDTH, NC, BPC, C, IPR, and UnkC.](678ac9faaa56bb929499cebeea83a110_img.jpg) + +| | | | | | | | +|--------|-------|----|-----|------|---|-----| +| | | | | | C | IPR | +| HEIGHT | WIDTH | NC | | | | | +| | | | BPC | UnkC | | | + +Diagram showing the organization of the contents of an image header box. It consists of fields for HEIGHT, WIDTH, NC, BPC, C, IPR, and UnkC. + +**Figure B.20 – Organization of the contents of an image header box** + +| | | +|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| <b>HEIGHT:</b> | Image area height. The value of this parameter indicates the height of the image area. This field is stored as a 4-byte big endian unsigned integer. This field is identical to that defined in Rec. ITU-T T.800 ISO/IEC 15444-1 clause I.5.3.2. | +| <b>WIDTH:</b> | Image area width. The value of this parameter indicates the width of the image area. This field is stored as a 4-byte big endian unsigned integer. This field is identical to that defined in Rec. ITU-T T.800 ISO/IEC 15444-1 clause I.5.3.2. | +| <b>NC:</b> | Number of components. This parameter specifies the number of components in the codestream and is stored as a 2-byte big endian unsigned integer. This field is identical to that defined in Rec. ITU-T T.800 ISO/IEC 15444-1 clause I.5.3.2. | +| <b>BPC:</b> | Bits per component. This parameter specifies the bit depth of the components in the image, minus 1, and is stored as a 1-byte field. If the bit depth and the sign are the same for all components, then this parameter specifies that bit depth. If the components vary in bit depth and/or sign, then the value of this field shall be 255 and the JP2 header box shall also contain a bits per component box defining the bit depth of each component (as defined in Rec. ITU-T T.800 ISO/IEC 15444-1 clause I.5.3.2). The low 7-bits of the value indicate the bit depth of the components. The high-bit indicates whether the components are signed or unsigned. If the high-bit is 1, then the components contain signed values. If the high-bit is 0, then the components contain unsigned values. Legal values of this field are given in Table B.21. | +| <b>C:</b> | Compression type. This parameter specifies the compression algorithm used to compress the image data. It is encoded as a 1-byte unsigned integer. See Table B.24 for legal values of C. | +| <b>UnkC:</b> | Colourspace unknown. This field specifies if the actual colourspace of the image is known. This field is encoded as a 1-byte unsigned integer. Legal values for this field are 0, if the colourspace of the image is known and correctly specified in the colourspace specification box within the file, or 1, if the colourspace of the image is not known. A value of 1 will be | + +used in cases such as the transcoding of legacy images where the actual colourspace of the image data is not known. Values other than 0 and 1 are reserved for ISO use. This field is identical to that defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 clause I.5.3.2. + +**IPR:** Intellectual property. This parameter indicates whether this file contains intellectual property rights information. If the value of this field is 0, this image does not contain rights information. If the value is 1, then the image does have associated right information and thus does contain an IPR box as defined in clause C.2.1. Other values are reserved for ISO use. This field is identical to that defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 clause I.5.3.2. + +**Table B.23 – Format of the contents of the image header box** + +| Field name | Size (bits) | Value | +|------------|-------------|----------------| +| HEIGHT | 32 | $1-(2^{32}-1)$ | +| WIDTH | 32 | $1-(2^{32}-1)$ | +| NC | 16 | 1-16 384 | +| BPC | 8 | See Table B.21 | +| C | 8 | See Table B.24 | +| UnkC | 8 | 0-1 | +| IPR | 8 | 0-1 | + +**Table B.24 – Legal C values for the image header box** + +| Value | Meaning | +|--------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 0 | Uncompressed. Picture data is stored in component interleaved format, encoded at the bit depth as specified by the BPC field. This value is only permitted for codestreams where all components are encoded at the same bit depth. When the bit depth of each component is not 8, sample values shall be packed into bytes so that no bits are unused between samples. However, each sample shall begin on a byte boundary and padding bits having value zero shall be inserted after the last sample of a scan line as necessary to fill out the last byte of the scan line. Simple values appear in component-interleaved order. When multiple sample values are packed into a byte, the first sample shall appear in the most significant bits of the byte. When a sample is larger than a byte, its most significant bit shall appear in earlier bytes. | +| 1 | Rec. ITU-T T.4, the basic algorithm known as MH (Modified Huffman). This value is only permitted for bi-level images. | +| 2 | Rec. ITU-T T.4, commonly known as MR (Modified READ). This value is only permitted for bi-level images. | +| 3 | Rec. ITU-T T.6, commonly known as MMR (Modified Modified READ). This value is only permitted for bi-level images. | +| 4 | Rec. ITU-T T.82 ISO/IEC 11544. Commonly known as JBIG. This value is only permitted for bi-level images. | +| 5 | Rec. ITU-T T.81 ISO/IEC 10918-1 or Rec. ITU-T T.84 ISO/IEC 10918-3. Commonly known as JPEG. This compressed image stream shall conform to the syntax of interchange format for compressed image data as specified in the aforementioned standards. This value is only permitted for continuous tone, greyscale or colour images. | +| 6 | Rec. ITU-T T.87 (JPEG-LS). | +| 7 | ISO/IEC 15444-1 (JPEG 2000 Part 1). | +| 8 | Rec. ITU-T T.88 (JBIG2) coding. | +| 9 | Rec. ITU-T T.82 ISO/IEC 11544. Commonly known as JBIG. This value is permitted for any image permitted by the JBIG standard. | +| other values | Reserved for ISO use. | + +#### B.6.2.2 Colour specification box + +Box type: 'colr' (0x636F6C72) + +Mandatory: No + +Location: Anywhere after image header box in a JP2 header box + +A colour specification box defines a method by which an application can interpret the colourspace of the decompressed image data. This colour specification is to be applied to the image data after it has been decompressed and after any reverse decorrelating component transform has been applied to the data. + +A JP2 header box in a JPM file may contain multiple colour specification boxes, but must contain at least one. A conforming JPM reader shall ignore all colour specification boxes after the first. + +The type of a colour specification box shall be 'colr' (0x636F6C72). This box contains the following fields: + +![Diagram showing the organization of a colour specification box. The box is divided into several fields: METH (1 byte), APPROX (1 byte), EnumCS (4 bytes), and EP (variable length). The PROFILE field is also shown. The diagram uses boxes and arrows to indicate the structure and relationships between these fields.](7e61b2e2506cc7e5d6e16ce9c9df25bb_img.jpg) + +The diagram illustrates the layout of a colour specification box. It shows a sequence of fields: METH (1 byte), APPROX (1 byte), EnumCS (4 bytes), and EP (variable length). The PROFILE field is also indicated. The diagram uses boxes and arrows to show the structure and relationships between these fields. + +Diagram showing the organization of a colour specification box. The box is divided into several fields: METH (1 byte), APPROX (1 byte), EnumCS (4 bytes), and EP (variable length). The PROFILE field is also shown. The diagram uses boxes and arrows to indicate the structure and relationships between these fields. + +**Figure B.21 – Organization of the contents of a colour specification box in JPM** + +- METH:** Specification method. This field specifies the method used by this colour specification box to define the colourspace of the image. This field is encoded as a 1-byte unsigned integer. The value for this field in a JPM file shall be 1 or 2, as defined in Rec. ITU-T T.800 | ISO/IEC 15444-1 clause I.5.3.3. +- PREC:** Precedence. This field is reserved for ISO use and the value shall be set to zero; however conforming readers shall ignore the value of the field. This field is specified as a signed 1-byte integer. +- APPROX:** Colourspace approximation. This field specifies the extent to which this colour specification method approximates the "correct" definition of the colourspace. The value of this field shall be set to zero; however, conforming readers shall ignore the value of this field. Other values are reserved for other ISO use. This field is specified as a 1-byte unsigned integer. +- EnumCS:** Enumerated colourspace. This field specifies the colourspace of the image using integer codes. To correctly interpret the colour of an image using an enumerated colourspace, the application must know the definition of that colourspace internally. This field contains a 4-byte big endian unsigned integer value indicating the colourspace of the image. Valid EnumCS values are defined in Table B.26. A mask object must use the greyscale or bi-level enumerated colourspace. +- EP:** Enumerated parameters; this field contains a series of parameters that augment the generic colourspace definition specified by EnumCS. Together, the EnumCS and EP fields describe the colourspace and how that colourspace has been encoded in the JPM file. If a value of EP is not defined for a particular value of EnumCS, then the length of the EP field for that EnumCS value shall be zero, indicating that the EnumCS value alone describes the colourspace or that default values are used as defined by the referenced colourspace. This field shall not exist if the value of the METH field is 2. +- PROFILE:** ICC profile. This field contains a valid ICC profile, as specified by the ICC profile format specification, which specifies the transformation of the decompressed image data into the PCS. This field shall not exist if the value of the METH field is 1. If the value of the METH field is 2, then the ICC profile shall conform to the monochrome input profile class or the three-component matrix-based input profile class as defined in ICC.1:1998-09. + +Table B.25 – Legal METH values + +| Value | Meaning | +|--------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 1 | <b>Enumerated colourspace.</b> This colour specification box contains the enumerated value of the colour-space of this image. The enumerated value is found in the EnumCS field in this box. If the value of the METH field is 1, then the EnumCS shall exist in this box immediately following the APPROX field. | +| 2 | <p><b>Restricted ICC profile.</b> This colour specification box contains an ICC profile in the PROFILE field. This profile shall specify the transformation needed to convert the decompressed image data into the PCSXYZ space, and shall conform to either the monochrome input or three-component matrix-based input profile class, and contain all the required tags specified therein, as defined in ICC.1:1998-09. As such, the value of the profile connection space field in the profile header in the embedded profile shall be 'XYZ\040' (0x5859 5A20) indicating that the output colourspace of the profile is in the XYZ colourspace.</p> <p>Any private tags in the ICC profile shall not change the visual appearance of an image processed using this ICC profile.</p> <p>The components from the codestream may have a range greater than the input range of the tone reproduction curve (TRC) of the ICC profile. Any decoded values should be clipped to the limits of the TRC before processing the image through the ICC profile. For example, negative sample values of signed components may be clipped to zero before processing the image data through the profile.</p> <p>See Rec. ITU-T T.800 ISO/IEC 15444-1 clause J.9 for a more detailed description of the legal colourspace transforms, how those transforms are stored in the file, and how to process an image using that transform without using an ICC colour management engine.</p> <p>If the value of METH is 2, then the PROFILE field shall immediately follow the APPROX field and the PRO- FILE field shall be the last field in the box.</p> | +| other values | Reserved for ISO use. If the value of METH is not 1 or 2, there may be fields in this box following the APPROX field, and a conforming JPM reader shall ignore the entire colour specification box. | + +Table B.26 – Legal EnumCS values + +| Value | Meaning | +|-------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 0 | <b>Bi-level:</b> This value is used to indicate bi-level images. Each image sample is one bit: 0 = white, 1 = black. | +| 3 | <b>YCbCr(2):</b> This is the most commonly used format for image data that was originally captured in RGB (uncalibrated format). The colourspace is based on Recommendation ITU-R BT.601-5. The valid ranges of the YCbCr components in this space are [0,255] for Y, and [−128,127] for Cb and Cr (stored with an offset of 128 to convert range to [0,255]). These ranges are different from the ones defined in Recommendation ITU-R BT.601-5. Recommendation ITU-R BT.601-5 specifies a 3x3 matrix transform that can be used to convert these samples into RGB. | +| 14 | <b>CIELab:</b> The CIE 1976 (L*a*b*) colourspace. A colourspace defined by the CIE (Commission Internationale de l' Eclairage), having approximately equal visually perceptible differences between equally spaced points throughout the space. The three components are L*, or lightness, and a* and b* in chrominance. For this colourspace, additional enumerated parameters are specified in the EP field as specified in clause B.6.2.2.1 | +| 16 | <b>sRGB</b> as defined in IEC 61966-2 | +| 17 | <p><b>Greyscale:</b> A greyscale space where image luminance is related to code values using the sRGB non-linearity given in Equations (2) through (4) of IEC 61966-2-1 (sRGB) specification:</p> $Y' = Y_{8bit} / 255 \tag{B.1}$ $\text{for } (Y' \leq 0.04045), Y_{\text{lin}} = Y' / 12.92 \tag{B.2}$ $\text{for } (Y' > 0.04045), Y_{\text{lin}} = \left( \frac{Y' + 0.055}{1.055} \right)^{2.4} \tag{B.3}$ <p>where <math>Y_{\text{lin}}</math> is the linear image luminance value in the range 0.0 to 1.0. The image luminance values should be interpreted relative to the reference conditions in Section 2 of IEC 61966-2-1.</p> | +| 18 | <p><b>sRGB YCC</b> as defined by IEC 61966-2-1 Amd. 1.</p> <p>It is not recommend to use ICT or RCT specified in Rec. ITU-T T.800 ISO/IEC 15444-1 Annex G with sYCC image data. See Rec. ITU-T T.800 ISO/IEC 15444-1 clause J.15 for guidelines on handling YCC codestreams.</p> | + +Table B.27 – Format of the contents of the colour specification box + +| Field name | Size (bits) | Value | +|------------|---------------------------------|-------------------------| +| METH | 8 | 1 -2 | +| PREC | 8 | 0 | +| APPROX | 8 | 0 | +| EnumCS | 32 if METH = 1<br>0 if METH = 2 | See Table B.26 no value | +| PROFILE | variable | variable | +| EP | variable | variable | + +###### B.6.2.2.1 EP field format for the CIELab colourspace + +If the value of EnumCS is 14, specifying that the image is encoded in the CIELab colourspace, then the format of the EP field shall be as follows: + +![](aeb2a26a07219661191294dba528067a_img.jpg) + +| | | | | | | | +|----|----|----|----|----|----|----| +| RL | OL | RA | OA | RB | OB | IL | +|----|----|----|----|----|----|----| + +Figure B.22 – Organization of the contents of the EP field for CIELab (EnumCS = 14) + +The RL, OL, RA, OA, RB, and OB fields describe how to convert between the unsigned values $N_L$ , $N_a$ , $N_b$ , as defined by ITU-T T.42, that are sent to the compressor or received from the decompressor and the signed CIELab values $L^*$ , $a^*$ , $b^*$ as defined by the CIE. According to Recommendation. ITU-T T.42, the calculations from real values $L^*$ $a^*$ $b^*$ to $n_L$ $n_a$ $n_b$ bit integers, which are expressed by $N_L$ $N_a$ $N_b$ are made as follows: + +$$N_L = \frac{2^{n_L}}{RL} \times L^* + OL \quad (B.4)$$ + +$$N_a = \frac{2^{n_a}}{RA} \times a^* + OA \quad (B.5)$$ + +$$N_b = \frac{2^{n_b}}{RB} \times b^* + OB \quad (B.6)$$ + +The IL field specifies the illuminant data used in calculating the CIELab values. + +- RL: Range for $L^*$ . This field specifies the RL value from Equation B.4. It is encoded as a 4-byte big endian unsigned integer. +- OL: Offset for $L^*$ . This field specifies the OL value from Equation B.4. It is encoded as a 4-byte big endian unsigned integer. +- RA: Range for $a^*$ . This field specifies the RA value from Equation B.5. It is encoded as a 4-byte big endian unsigned integer. +- OA: Offset for $a^*$ . This field specifies the OA value from Equation B.5. It is encoded as a 4-byte big endian unsigned integer. +- RB: Range for $b^*$ . This field specifies the RB value from Equation B.6. It is encoded as a 4-byte big endian unsigned integer. +- OB: Offset for $b^*$ . This field specifies the OB value from Equation B.6. It is encoded as a 4-byte big endian unsigned integer. +- IL: Illuminant. This field specifies the illuminant data used in calculating the CIELab values. Rather than specify the XYZ values of the normalizing illuminant, which are used in calculating CIELab, the specification of the illuminant data follows Recommendation ITU-T T.4 Annex E. The illuminant data consists of 4 bytes, identifying the illuminant. In the case of a standard illuminant, the 4 bytes are one of the following in Table B.28. + +Table B.28 – Standard illuminant values for CIELab + +| Standard IL field value | Illuminant | +|-------------------------|--------------------| +| 0x0044 3530 | CIE Illuminant D50 | +| 0x0044 3635 | CIE Illuminant D65 | +| 0x0044 3735 | CIE Illuminant D75 | +| 0x0000 5341 | CIE Illuminant SA | +| 0x0000 5343 | CIE Illuminant SC | +| 0x0000 4632 | CIE Illuminant F2 | +| 0x0000 4637 | CIE Illuminant F7 | +| 0x0046 3131 | CIE Illuminant F11 | + +When the illuminant is specified by a colour temperature, then the 4 bytes consist of the string CT, followed by two unsigned bytes representing the temperature of the illuminant in degrees Kelvin as a 2-byte big endian unsigned integer. For example, a 7500K illuminant is represented by the 4 bytes 0x4354 1D4C. + +When the EP field is omitted for the CIELab colourspace, then the following default values shall be used. The default L\*, a\*, b\* range parameters are 100, 170 and 200. The default L\*, a\* and b\* offset values are 0, $2^{Na-1}$ and $2^{Nb-2} + 2^{Nb-3}$ . These defaults correspond to the CIELab encoding in Recommendation ITU-T T.42. The default value of the IL field is 0x0044 3530, specifying CIE Illuminant D50. + +Other applications may use other range values by specifying EP field values. For example, the CIELab encoding in the ICC profile format specification, ICC.1:2001-11 specifies ranges and offsets for the CIELab encoding that are different than the defaults given here. If the values specified in the CIELab encoding in the ICC profile format specification, ICC.1:2001-11 are used, then they would have to be explicitly given in the EP fields. + +Table B.29 – Format of the contents of the EP field for CIELab (EnumCS = 14) + +| Field name | Size (bits) | Value | +|------------|-------------|--------------------| +| RL | 32 | $0 - (2^{32} - 1)$ | +| OL | 32 | $0 - (2^{32} - 1)$ | +| RA | 32 | $0 - (2^{32} - 1)$ | +| OA | 32 | $0 - (2^{32} - 1)$ | +| RB | 32 | $0 - (2^{32} - 1)$ | +| OB | 32 | $0 - (2^{32} - 1)$ | +| IL | 32 | See Table B.28 | + +### B.6.3 Label box + +- Box type: 'lbl\040'(0x6C626C20) +- Container: Layout Object, Object, Page or Page Collection box +- Mandatory: No +- Quantity: Any number +- Location: Anywhere + +The type of a label box shall be 'lbl\040' (0x6C626C20). The contents of the label box are as follows: + +![A diagram showing a square box with a diagonal line from the top-left to the bottom-right, representing a label box.](f5d2a88925807080157c7cfb1d41cf0b_img.jpg) + +S + +A diagram showing a square box with a diagonal line from the top-left to the bottom-right, representing a label box. + +Figure B.23 – Organization of the contents of a label box + +- S: Label string. A textual label associated with a layout object, object, page or a page collection. This value is stored as ISO 10646 characters in the UTF-8 encoding. Characters in the ranges U+0000 to U+001F inclusive and U+007F to U+009F inclusive, as well as the specific characters '/', ';', '?', ':', and '#', are not permitted in the label string. Label strings are not null-terminated or padded in any other way; every character that is present is significant. + +### **B.6.4 Cross-reference box** + +- Box type: 'cref' (0x63726566) +- Container: See details below +- Mandatory: No +- Quantity: Any number +- Location: Anywhere + +If a JPM file contains multiple codestreams or layout objects, it may be useful to share header and metadata information to minimize file size. One mechanism to share such data is to use a cross-reference to the actual header or metadata box in place of the actual data. This is done using a cross-reference box. A JPM file may contain zero or more cross-reference boxes and a cross-reference box shall not point to another cross- reference box. + +The type of the cross-reference box shall be 'cref' (0x63726566) and it shall have the following contents: + +![Diagram showing the organization of the contents of a cross-reference box. It consists of two adjacent rectangular boxes. The left box is labeled 'Rtyp' and the right box is labeled 'flst' above it.](508bc574df81fa8d3027a374f6d155fc_img.jpg) + +The diagram illustrates the structure of a cross-reference box. It contains two fields: 'Rtyp' (Referenced box type) and 'flst' (Fragment list box). 'Rtyp' is represented by a rectangle with a vertical line on its right side. 'flst' is represented by a rectangle with a diagonal hatching pattern. + +Diagram showing the organization of the contents of a cross-reference box. It consists of two adjacent rectangular boxes. The left box is labeled 'Rtyp' and the right box is labeled 'flst' above it. + +**Figure B.24 – Organization of the contents of a cross-reference box** + +- Rtyp:** Referenced box type. This field specifies the actual type (as would be found in the TBox field in an actual box header) of the box referenced by this cross-reference box. However, a reader shall not attempt to locate a physically stored box header for the box represented by this cross-reference box, as it is legal to use a cross-reference box to create a new box that is not contiguously contained in other locations within this or other files, and thus the box header may not exist. This field is encoded as a 4-byte value. +- flst:** Fragment list box. This box specifies the actual locations of the fragments of the referenced box. When those fragments are concatenated, in order, as specified by the fragment list box definition, the resulting byte-stream shall be the entire referenced box and shall not include the box header fields. However, if the referenced box is a superbox, then the offset of the first fragment does point to the box header of the first box contained within the superbox. The format of the fragment list box is specified in clause B.5.1.1. + +**Table B.30 – Format of the contents of the cross-reference box** + +| Field name | Size (bits) | Value | +|------------|-------------|--------------------------| +| Rtyp | 32 | 0 – (2 <sup>32</sup> –1) | +| flst | variable | variable | + +### **B.6.5 Hidden text metadata box (superbox)** + +- Box type: 'htxb' (0x68747862) +- Container: Page box or file +- Mandatory: No +- Quantity: At most one if the container is the page box, any number if the container is the file +- Location: Anywhere in the page box after the page header box if the container is the page box, or anywhere after the file type box if the container is the file. + +The hidden text metadata box ('htxb') serves as a container for hidden text data. It is a superbox that may contain an optional label box and must contain one of two box types. It may either contain one XML box containing hidden text metadata, or it may contain one UUID box containing hidden text metadata as specified in clause F.2. + +The type of a hidden text metadata box shall be 'htxb' (0x68747862). The contents of a hidden text metadata box shall be as in Figure B.25: + +![Diagram showing two possible structures for a hidden text metadata box. The first structure consists of a 'label' box followed by an 'xml' box. The second structure consists of a 'label' box followed by a 'uuid' box. The two structures are separated by the word 'or'.](284768c5ee1a05aa1b9ce396f606a040_img.jpg) + +``` +graph LR + subgraph Structure1 [ ] + direction LR + L1[label] --- X1[xml] + end + or[or] + subgraph Structure2 [ ] + direction LR + L2[label] --- U2[uuid] + end +``` + +Diagram showing two possible structures for a hidden text metadata box. The first structure consists of a 'label' box followed by an 'xml' box. The second structure consists of a 'label' box followed by a 'uuid' box. The two structures are separated by the word 'or'. + +Figure B.25 – Organization of the contents of a hidden text metadata box + +### **B.6.6 HTX reference box** + +- Box type: 'phtx' (0x70687478) +- Container: Page box +- Mandatory: No +- Quantity: At most one +- Location: Anywhere in the page box after the page header box + +If the hidden text for a page is contained in a hidden text metadata box within the corresponding page box, this box must not appear. If the hidden text for a page is contained in a series of one or more hidden text metadata boxes at the file level, one HTX reference box has to be included in the corresponding page box. + +The type of an HTX reference box shall be 'phtx' (0x70687478). The contents of an HTX reference box shall be as in Figure B.26: + +![Diagram showing the organization of the contents of an HTX reference box. It consists of three fields: 'Rtyp', 'flst', and 'label'. The 'Rtyp' field is the first and is shaded. The 'flst' and 'label' fields are the second and third, respectively, and are also shaded.](3e2dcee303cecdd31b7f9ec0d8942fed_img.jpg) + +``` +graph LR + Rtyp[Rtyp] --- flst[flst] --- label[label] +``` + +Diagram showing the organization of the contents of an HTX reference box. It consists of three fields: 'Rtyp', 'flst', and 'label'. The 'Rtyp' field is the first and is shaded. The 'flst' and 'label' fields are the second and third, respectively, and are also shaded. + +Figure B.26 – Organization of the contents of an HTX reference box + +- Rtyp: Referenced box type. This field specifies the actual type (as would be found in the TBox field in an actual box header) of the box referenced by this HTX reference box. However, a reader shall not attempt to locate a physically stored box header for the box represented by this HTX reference box, as it is legal to use an HTX reference box to create a new box that is not contiguously contained in other locations within this or other files, and thus the box header will not exist. +- flst: Fragment list box. This box specifies the actual locations of the fragments of the referenced HTX element. When those fragments are concatenated, in order, as specified by the fragment list box definition, the resulting byte-stream shall be the contents of the referenced HTX element, which contains hidden text data, and shall not include the box header fields. The format of the fragment list box is specified in clause B.5.1.1. If Rtyp is 'uuid' and the UUID signals deflate compression as defined in clause F.2, the number of fragments of the fragment list box must be one. +- label: Label box. This optional box may contain a label box which specifies a label or name for the hidden text of the corresponding page. The structure of a label box is specified in clause B.6.3. + +Table B.31 – HTX reference box contents data structure values + +| Parameter | Size (bits) | Value | +|-----------|-------------|----------------| +| Rtyp | 32 | See Table B.32 | +| flst | Variable | Variable | +| label | Variable | Variable | + +Table B.32 – Legal Rtyp values + +| Value | Meaning | +|--------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| xml\40 | The referenced HTX data shall be contained in an XML box as described in Annex F. The XML box is defined in clause I.7.1 of Rec. ITU-T T.800 (2002) ISO/IEC 15444-1:2004. | +| uuid | The referenced HTX data shall be contained in a UUID box as described in Annex F. The UUID box is defined in clause I.7.2 of Rec. ITU-T T.800 (2002) ISO/IEC 15444-1:2004. | +| other values | All other values reserved | + +### **B.6.7 Free box** + +Box type: 'free' (0x66726565) + +Container: Anywhere + +Container: Any Mandatory: No + +Quantity: Any number + +The free box specifies a section of the JPM file that is not currently used and may be overwritten when editing the file. Readers shall ignore all free boxes. + +The type of a free box shall be 'free' (0x66726565). The contents of a free box in general are not defined by this International Standard. + +# Annex C + +## Metadata + +(This annex forms an integral part of this Recommendation | International Standard.) + +A JPM file may contain metadata boxes with intellectual property rights information or vendor specific information, as defined in this annex. Metadata boxes are optional in a JPM file and may be ignored by conforming readers. In addition, a JPM file may contain other metadata boxes not defined in this annex. + +## C.1 Adding intellectual property rights information in JPM + +ISO 15444-1/ITU-T 800 specifies a box type for a box that is devoted to carrying intellectual property rights information. Specifying the box type allows applications to recognize the existence of IPR information in a JPM file. Use and interpretation of this information is beyond the scope of this International Standard. Inclusion of this information in a JPM file is optional for conforming files. The definition of the format of the contents of this box is reserved for ISO. The type of the intellectual property Box shall be 'jp2i' (0x6A70 3269). + +## C.2 Adding vendor specific information to the JPM file format + +The following boxes provide a set of tools by which applications can add vendor specific information to the JPM file format. All of the following boxes are optional in conforming files and may be ignored by conforming readers. + +### C.2.1 XML boxes + +An XML box contains vendor specific information (in XML format) other than the information contained within boxes defined by this International Standard. There may be multiple XML boxes within the file, and those boxes may be found in an object box, layout object box, page box, page collection box, or anywhere at the file level except before the file type box. The XML box is defined in clause I.7.1 of Rec. ITU-T T.800 | ISO/IEC 15444-1. + +### C.2.2 UUID boxes + +A UUID box contains vendor specific information other than the information contained within boxes defined within this International Standard. There may be multiple UUID boxes within the file, and those boxes may be found in an object box, layout object box, page box, page collection box, or anywhere at the file level except before the file type box. The UUID box is defined in clause I.7.2 of Rec. ITU-T T.800 | ISO/IEC 15444-1. + +### C.2.3 UUID Info boxes (superbox) + +While it is useful to allow vendors to extend JPM files by adding information using UUID boxes, it is also useful to provide information in a standard form which can be used by non-extended applications to get more information about the extensions in the file. This information is contained in UUID Info boxes. A JPM file may contain zero or more UUID Info boxes. These boxes may be found anywhere in the top level of the file (the superbox of a UUID Info box shall be the JPM file itself) except before the file type box. + +These boxes, if present, may not provide a complete index for the UUID's in the file, may reference UUID's not used in the file, and possibly may provide multiple references for the same UUID. The UUID Info box is defined in clause I.7.3 of Rec. ITU-T T.800 | ISO/IEC 15444-1. + +# Annex D + +## Profiles + +(This annex forms an integral part of this Recommendation | International Standard.) + +This annex defines the profiles to which a JPM file can conform. In particular, this annex defines the values of the P field in the compound image header box. A profile defines legal values of various fields in a JPM file. + +## D.1 JPM profiles + +The P field of the compound image header box, defined in clause B.1.4, shows the profile to which the JPM file conforms. A profile defines legal values of various fields in a JPM file. This annex gives the legal values for the P field values specified in the compound image header box. + +### D.1.1 Web profile + +The profile field value for the web profile is 1. The following table gives values for boxes in a JPM file when the profile is in use. + +Table D.1 – Web profile values + +| Box | Field | Value | Comment | +|--------------------------------------------|--------|-------------------------------------|------------------------------------------------------------------------------------------------| +| Compound image header | MC | xxxx x1xx<br>xx1x xxxx<br>xxx1 xxxx | Rec. ITU-T T.6 (MMR)<br>Rec. ITU-T T.88 (JBIG2 profile)<br>Rec. ITU-T T.800 (JPEG 2000 Part 1) | +| | IC | xxxx xxx1<br>xxx1 xxxx<br>xxxx x1xx | Rec. ITU-T T.81 (JPEG)<br>Rec. ITU-T T.800 (JPEG 2000 Part 1)<br>Rec. ITU-T T.45 | +| Image header (in mask object box) | C | 3<br>7<br>8 | Rec. ITU-T T.6 (MMR)<br>Rec. ITU-T T.88 (JBIG2 profile)<br>Rec. ITU-T T.800 (JPEG 2000 Part 1) | +| Image header (in image object box) | C | 5<br>7<br>10 | Rec. ITU-T T.81 (JPEG)<br>Rec. ITU-T T.800 (JPEG 2000 Part 1)<br>Rec. ITU-T T.45 | +| | BPC | – | All image components shall have the same bits per component value | +| Colour specification (in image object box) | METH | 1<br>2 | Enumerated colourspace<br>Restricted ICC profile | +| | EnumCS | 16<br>17<br>14<br>3<br>18 | sRGB<br>Greyscale<br>CIELab<br>YCbCr(2)<br>sRGB sYCC | + +The mask objects in a JPM file conforming to the web profile can use MMR, JBIG2 or JPEG 2000 compression; only JPEG 2000 can be used when the mask has more than one bit per component. The image objects in a conforming JPM file can use JPEG or JPEG 2000. + +In this profile, all components of an image object shall have the same number of bits per component. All image objects within a page box shall have the same colour specification; image objects included by reference within a page box may or may not have the same colour specification as the image objects directly located within the page box. + +## D.2 Decompression profiles + +There are also profiles that determine the use of the compression methods allowed in a JPM file. Table D.2 shows the decompression profiles that are legal in a JPM file. + +**Table D.2 – Decompression profile values** + +| Compression method | Profile | +|--------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| JPEG 2000 | JPEG 2000 Profile 1 (Rec. ITU-T T.800 ISO/IEC 15444-1), Cclass1 (Rec. ITU-T T.803 ISO/IEC 15444-4), with maximum image height or width of 16,384. | +| JPEG | Baseline JPEG (ISO 10918-1) | +| JBIG2 | ITU-T T.88 profiles F3, F4, F5, F6 and F7, or ITU-T T.89, all profiles.<br>When using T.88 profiles F6 or F7, or T.89 profiles 0x0000101 or 0x00000103, no mixing of types within a stripe may occur; there must be 2 or more stripes per page | + +# **Annex E** + +This annex is intentionally left blank. + +# Annex F + +## Hidden text and annotations storage + +(This annex forms an integral part of this Recommendation | International Standard.) + +## F.1 Storage of HTX in JPM + +A hidden text XML element is restricted to represent text for a single page. It is stored in a hidden text metadata box as defined in clause B.6.5. The hidden text metadata box either appears within the corresponding page box or is placed at the top level of the file. If placed on the top level, an HTX reference box as defined in clause B.6.6 must be placed in the corresponding page box to point to the hidden text metadata boxes that composes the hidden text of the page. + +When a hidden text metadata box is small in size, it is reasonable to place it directly in the page box. In keeping with the usual JPM approach, large objects are generally placed at the top file level. In this case, the much smaller HTX reference box is placed in the page box and points to the actual data. Also in this case a single HTX reference box can point to multiple file level hidden text metadata boxes. This can be used to compose the HTX for many pages from combinations of fixed page content (such as page headers and footers) and variable page content unique to each page. + +XML data representing hidden text and annotations is defined using XML 1.0, and conforms to the schemas in Annex H. It shall be referred to as "Hidden Text XML" or HTX. + +HTX shall be stored in a hidden text metadata box as defined in clause B.6.5. + +The storage of uncompressed HTX may increase file size considerably. In order to minimise the increase in file size, HTX may be compressed using the mechanisms defined in clause F.2. + +## F.2 Compression of HTX + +HTX may be compressed using the zlib format defined in IETF RFC 1950 with DEFLATE compression defined in IETF RFC 1951. + +UUID boxes shall be used for the storage of compressed HTX in the JPM file format. + +Compressed HTX shall be stored in a UUID box, as defined in clause I.7.3 of Rec. ITU-T T.800 | ISO/IEC 15444-1:2004, with the following contents: + +**ID** This field shall contain the following 16 hexadecimal bytes: + +c2 f3 66 a4 27 ec 40 c4 a0 9a 7e 65 2f 36 eb 59 + +**DATA** This field will contain hidden text XML compressed to the DEFLATE format, as specified in clause F.1. + +A UUID box with the above content shall be referred to as a *hidden text UUID box*. + +The following URL may be used in a UUID data entry box, as defined in clause I.7.3.2 of Rec. ITU-T T.800 | ISO/IEC 15444-1:2004, to describe the format of the data contained in hidden text UUID boxes: + +<http://www.jpeg.org/hiddentext/htx.html> + +# Annex G + +## Hidden text and annotations types and elements + +(This annex forms an integral part of this Recommendation | International Standard.) + +## G.1 Overview + +*This section describes each of the HTX types and elements, and how they are to be used and interpreted.* + +Annex H formally describes the schemas that the hidden text XML must conform to. Here the text is a description of each of the elements, what they are for, how they relate to each other, how often they can occur, how they are to be interpreted. + +Hidden text can be encoded using subelements at different levels of detail as described in this section. This can be used to structure the hidden text and give it a text flow in regions, paragraphs, lines, words, etc. Whenever this kind of structured information is not available, the hidden text can be directly put into the appropriate elements, omitting specific positioning of lines inside paragraphs, words inside lines, etc. The following picture gives an overview of the various elements that can be used to store the hidden text of a page: + +![Figure G.1 – Structure of HTX. A hierarchical tree diagram showing the structure of hidden text elements. The root is 'htx', which branches into 'xhtml:head' (0..1), 'annotations' (0..1), and 'hiddentext' (0..1). 'hiddentext' branches into 'region' (1..∞) and 'param' (0..∞). 'region' branches into 'paragraph' (0..∞), 'line' (0..∞), 'word' (0..∞), 'char' (0..∞), 'snippet' (0..∞), 'param' (0..∞), and 'Text' (0..1). 'paragraph' branches into 'line' (0..∞), 'word' (0..∞), 'char' (0..∞), 'snippet' (0..∞), 'param' (0..∞), and 'Text' (0..1). 'line' branches into 'word' (0..∞), 'char' (0..∞), 'snippet' (0..∞), 'param' (0..∞), and 'Text' (0..1). 'word' branches into 'char' (0..∞), 'altword' (0..∞), 'snippet' (0..∞), 'param' (0..∞), and 'Text' (0..1). 'altword' branches into 'char' (0..∞), 'snippet' (0..∞), 'param' (0..∞), and 'Text' (0..1). 'char' branches into 'altchar' (0..∞), 'param' (0..∞), and 'Text' (1). 'altchar' branches into 'param' (0..∞) and 'Text' (1). 'snippet' branches into 'param' (0..∞). 'param' branches into 'Text' (0..1).](8bd7adf738ea4b7e65e0d6f67e122d55_img.jpg) + +``` + +graph TD + htx[htx] -- 0..1 --> xhtml_head[xhtml:head] + htx -- 0..1 --> annotations[annotations] + htx -- 0..1 --> hiddentext[hiddentext] + + hiddentext -- 1..∞ --> region[region] + hiddentext -- 0..∞ --> param1[param] + + region -- 0..∞ --> paragraph[paragraph] + region -- 0..∞ --> line1[line] + region -- 0..∞ --> word1[word] + region -- 0..∞ --> char1[char] + region -- 0..∞ --> snippet1[snippet] + region -- 0..∞ --> param2[param] + region -- 0..1 --> Text1((Text)) + + paragraph -- 0..∞ --> line2[line] + paragraph -- 0..∞ --> word2[word] + paragraph -- 0..∞ --> char2[char] + paragraph -- 0..∞ --> snippet2[snippet] + paragraph -- 0..∞ --> param3[param] + paragraph -- 0..1 --> Text2((Text)) + + line2 -- 0..∞ --> word3[word] + line2 -- 0..∞ --> char3[char] + line2 -- 0..∞ --> snippet3[snippet] + line2 -- 0..∞ --> param4[param] + line2 -- 0..1 --> Text3((Text)) + + word3 -- 0..∞ --> char4[char] + word3 -- 0..∞ --> altword[altword] + word3 -- 0..∞ --> snippet4[snippet] + word3 -- 0..∞ --> param5[param] + word3 -- 0..1 --> Text4((Text)) + + altword -- 0..∞ --> char5[char] + altword -- 0..∞ --> snippet5[snippet] + altword -- 0..∞ --> param6[param] + altword -- 0..1 --> Text5((Text)) + + char4 -- 0..∞ --> altchar[altchar] + char4 -- 0..∞ --> param7[param] + char4 -- 1 --> Text6((Text)) + + altchar -- 0..∞ --> param8[param] + altchar -- 1 --> Text7((Text)) + + snippet5 -- 0..∞ --> param9[param] + + param6 -- 0..1 --> Text8((Text)) + +``` + +Figure G.1 – Structure of HTX. A hierarchical tree diagram showing the structure of hidden text elements. The root is 'htx', which branches into 'xhtml:head' (0..1), 'annotations' (0..1), and 'hiddentext' (0..1). 'hiddentext' branches into 'region' (1..∞) and 'param' (0..∞). 'region' branches into 'paragraph' (0..∞), 'line' (0..∞), 'word' (0..∞), 'char' (0..∞), 'snippet' (0..∞), 'param' (0..∞), and 'Text' (0..1). 'paragraph' branches into 'line' (0..∞), 'word' (0..∞), 'char' (0..∞), 'snippet' (0..∞), 'param' (0..∞), and 'Text' (0..1). 'line' branches into 'word' (0..∞), 'char' (0..∞), 'snippet' (0..∞), 'param' (0..∞), and 'Text' (0..1). 'word' branches into 'char' (0..∞), 'altword' (0..∞), 'snippet' (0..∞), 'param' (0..∞), and 'Text' (0..1). 'altword' branches into 'char' (0..∞), 'snippet' (0..∞), 'param' (0..∞), and 'Text' (0..1). 'char' branches into 'altchar' (0..∞), 'param' (0..∞), and 'Text' (1). 'altchar' branches into 'param' (0..∞) and 'Text' (1). 'snippet' branches into 'param' (0..∞). 'param' branches into 'Text' (0..1). + +Figure G.1 – Structure of HTX + +The hidden text XML schema (see H.1) uses some types and elements defined in the XHTML 1.0 XML schema. See the XHTML 1.0 reference for full details of these types and elements. + +The following additional types and elements are defined: + +## G.2 Types + +### G.2.1 Shape + +The **Shape** type is used to describe the shape of a region in the document and is defined by the following XML schema declaration: + +``` +<xs:simpleType name="Shape"> + <xs:annotation> + <xs:documentation>Enumeration of shapes.</xs:documentation> + </xs:annotation> + <xs:restriction base="xs:token"> + <xs:enumeration value="rect"/> + <xs:enumeration value="poly"/> + </xs:restriction> +</xs:simpleType> +``` + +### G.2.2 Coordinates + +The **Coords** type is used to store a comma separated sequence of non-negative integer values. This type is similar to the XHTML 1.0 **Coords** type but excludes negative and percentage values. The attribute specifies the position and shape of the area. The number and order of values depends on the value of the shape attribute. Possible combinations: + +- **rect**: left-x, top-y, right-x, bottom-y. +- **poly**: x1, y1, x2, y2, ..., xN, yN. +If the first and last x and y coordinate pairs are not the same, user agents must infer an additional coordinate pair to close the polygon. + +The **Coords** element is defined by the following XML schema declaration: + +``` +<xs:simpleType name="Coords"> + <xs:annotation> + <xs:documentation> + Comma separated list of integer values. + </xs:documentation> + </xs:annotation> + <xs:restriction base="xs:string"> + <xs:pattern value="\d+, \s*\d+ (, \s*\d+, \s*\d+)+" /> + </xs:restriction> +</xs:simpleType> +``` + +### G.2.3 Percentage + +A simple type **Percentage** is defined to store a string that holds a percent value indicating the confidence of a hidden text word or character match. **Percentage** is defined as follows: + +``` +<xs:simpleType name="Percentage"> + <xs:annotation> + <xs:documentation>Percentage value.</xs:documentation> + </xs:annotation> + <xs:restriction base="xs:string"> + <xs:pattern value="\d+ (\. \d+)?%" /> + </xs:restriction> +</xs:simpleType> +``` + +### G.2.4 Angle + +A simple type **Angle** is defined to store a string that indicates an angle for use in hidden text. The **Angle** type is defined as follows: + +``` +<xs:simpleType name="Angle"> + <xs:annotation> + <xs:documentation>nn for radian measure or nn° for +degree</xs:documentation> + </xs:annotation> + <xs:restriction base="xs:string"> + <xs:pattern value="[\-\.+]?[0-9]+(\.[0-9]+)?°"/> + </xs:restriction> +</xs:simpleType> +``` + +### G.2.5 Resolution + +A simple type **Resolution** is defined to store a string that indicates a resolution for use with coordinates in hidden text and annotations. The **Resolution** type is defined as follows: + +``` +<xs:simpleType name="Resolution"> + <xs:annotation> + <xs:documentation> +Resolution value in dots per inch (dpi). A single number stands for horizontal +and vertical resolution having the same values. Two numbers can be used to +define different resolutions for horizontal (first number) and vertical +(second number). + </xs:documentation> + </xs:annotation> + <xs:restriction base="xs:string"> + <xs:pattern value="\d+(\.[0-9]+)?(,\s*\d+(\.[0-9]+)?)" /> + </xs:restriction> +</xs:simpleType> +``` + +## G.3 Common attributes + +### G.3.1 Core attributes + +**Coreattrs**, a set of core attributes that are common to most elements, is defined as follows: + +``` +<xs:attributeGroup name="coreattrs"> + <xs:annotation> + <xs:documentation> +core attributes common to most elements +id document-wide unique id +class space separated list of classes +lang language code (backwards compatible) +xml:lang language code (as per XML 1.0 spec) +dir direction for weak/neutral text +href URI of the image corresponding to the region + </xs:documentation> + </xs:annotation> + <xs:attribute name="id" type="xs:ID" /> + <xs:attribute name="class" type="xs:NMTOKENS" /> + <xs:attribute name="href" type="xs:anyURI" /> + <xs:attributeGroup ref="xhtml:i18n" /> +</xs:attributeGroup> +``` + +The following attributes are members of the **Coreattrs** group: + +- **lang** (optional) + +An optional attribute of type **LanguageCode** to indicate the default language for text in the hidden text XML. Refer to the XHTML 1.0 specification for further details. + +- **xml:lang** (optional) + +An optional attribute of type **xml:lang** to indicate the default language for text in the hidden text XML. Refer to the XHTML 1.0 specification for further details. + +- **dir** (optional) + +An optional attribute containing the string **rtl** or **ltr**, indicating the default direction for text in the hidden text XML. Refer to the XHTML 1.0 specification for further details. + +- **id** (optional) + +An optional attribute of type xs:ID. Contains an id that is unique in the scope of this document. This attribute can be used for referencing a certain element (e.g., in a style sheet). See the XML schema specification for further details. + +- **class** (optional) + +This attribute can contain a space separated list of classes. Useful for convenient style sheet usage. + +- **href** (optional) + +- URI which points to an image file corresponding to the region. + +(ex.1 href="http://jpeg.org/image.jp2", ex.2 href="jpip://jpeg.org/image.jp2?fsiz=32,32&rsiz=32,32") + +### G.3.2 Position attributes + +**Posattrs**, a set of position attributes that are common to most visual elements, is defined as follows: + +``` +<xs:attributeGroup name="posattrs"> + <xs:annotation> + <xs:documentation> + positioning attributes common to most elements + </xs:documentation> + </xs:annotation> + <xs:attribute name="shape" type="Shape" default="rect" /> + <xs:attribute name="coords" type="Coords" /> + <xs:attribute name="angle" type="Angle" default="0" /> + <xs:attribute name="baseline" type="Angle" default="0" /> +</xs:attributeGroup> +``` + +The following attributes are members of the **Posattrs** group: + +- **shape** (optional) + +An optional attribute of type **Shape** containing the shape of the region bounding the element. Possible values are 'rect' for a rectangle and 'poly' for a polygon. The default value for this attribute is **rect**. If this attribute is missing then the bounding shape for this element is the bounding shape of the parent element (which is the whole page in the case of hiddentext). + +- **coords** (optional) + +The logical coordinates of the shape bounding the hidden text for this page. The unit is pixels. A resolution can be defined as an attribute on the htx element. If this attribute is missing then the bounding shape for this element is the bounding shape of the parent element (which is the whole page in the case of hiddentext). How the value of coords is to be interpreted depends on the shape attribute. The coord values unit is pixel; there is no percentage or any length unit like inch or centimetre. + +The origin (coordinates '0, 0') is the upper left corner of the page. + +- **angle** (optional) + +An attribute of type **Angle** that indicates the angle of orientation of the element, relative to the direction of the element's parent. + +Can either be in degree (value followed by a ° sign) or radian measure (value without unit). A value of 0 means the same direction as the element's parent, positive values mean rotating counter-clockwise relative to that direction. Default value is '0'. + +- **baseline** (optional) + +An attribute of type **Angle** that indicates the relative orientation of the sub elements and direct content contained in the element with respect to the direction given by the angle attribute. + +Can either be in degree (value followed by a ° sign) or radian measure (value without unit). A value of 0 means the same direction as the element, positive values mean rotating counter-clockwise relative to that direction. Default value is '0'. + +The values of shape and cords attribute should be interpreted as described in HTML 4.01 clause 13.6.1 section "AREA attribute definitions". + +## G.4 Elements + +### G.4.1 HTX + +The **htx** element, the global container and root elements for hidden text and annotations, is declared as follows: + +``` +<xs:element name="htx"> + <xs:annotation> + <xs:documentation> +Global container for hidden text and annotations. Contains language +attributes, an optional xhtml head and a mandatory body. + </xs:documentation> + </xs:annotation> + <xs:complexType> + <xs:sequence> + <xs:element ref="xhtml:head" minOccurs="0"/> + <xs:element ref="annotations" minOccurs="0"/> + <xs:element ref="hiddentext" minOccurs="0"/> + </xs:sequence> + <xs:attribute name="res" type="xs:Resolution" /> + <xs:attribute name="width" type="xs:integer" /> + <xs:attribute name="height" type="xs:integer" /> + <xs:attributeGroup ref="coreattrs"/> + </xs:complexType> +</xs:element> +``` + +This root element contains an optional **xhtml:head** element, an annotations element and a **hiddentext** element. + +#### Attributes: + +Core attributes apply. + +- **res** (optional) + +An optional attribute of type Resolution indicating the resolution for any coordinates in dots per inch (dpi). A single number stands for horizontal and vertical resolution having the same values. Two numbers can be used to define different resolutions for horizontal (first number) and vertical (second number). + +- **width** (optional) + +The width of the page in pixels. + +- **height** (optional) + +The height of the page in pixels. + +#### Elements + +- **xhtml:head** (at most one) + +An optional element containing general header data for the hidden text XML elements, including any required cascading style sheet data. Refer to the XHTML 1.0 specification for further details. + +- **annotations** (at most one) +An optional annotations element may be used to attach notes and to describe clickable and highlighted regions on a page. +- **hiddentext** (at most one) +An optional hiddentext containing the hidden text XML data for a page. + +#### **Direct content** + +- **none** + +### **G.4.2 Parameter** + +The **param** element is declared as follows: + +``` +<xs:element name="param"> + <xs:annotation> + <xs:documentation> + User defined properties for a hidden text and annotations object. + </xs:documentation> + </xs:annotation> + <xs:complexType mixed="true"> + <xs:attribute name="name" type="xs:string" use="required"/> + </xs:complexType> +</xs:element> +``` + +A **param** element of an HTX contains user-defined properties for the associated element, e.g., to specify the OCR engine used to generate the hidden text. + +#### **Attributes:** + +- **name** (mandatory) +A mandatory string attribute containing the name of this parameter. + +#### **Elements** + +- **none** + +#### **Direct content** + +- **value** + +An optional string attribute containing the value for this parameter. + +### **G.4.3 Hidden Text** + +The **hiddentext** element is used to represent the hidden text for a page and is declared as follows: + +``` +<xs:element name="hiddentext"> + <xs:annotation> + <xs:documentation> + A hiddentext element contains hidden text for a page. + </xs:documentation> + </xs:annotation> + <xs:complexType> + <xs:sequence> + <xs:element ref="param" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="region" maxOccurs="unbounded" /> + </xs:sequence> + <xs:attributeGroup ref="coreattrs" /> + <xs:attributeGroup ref="posattrs" /> + </xs:complexType> +</xs:element> +``` + +A **hiddentext** element of an HTX contains a sequence of **region** elements. + +#### Attributes: + +Core and position attributes apply. + +#### Elements + +- **param** (zero or more) +Optional sequence of parameter elements may be used to specify user-defined properties for hidden text. +- **region** (one or more) +Sequence of elements containing hidden text for regions in the page. + +#### Direct content + +- **none** + +### G.4.4 Region + +The **region** element is declared as follows: + +``` +<xs:element name="region"> + <xs:annotation> + <xs:documentation> +A region element contains hidden text for a page region. + </xs:documentation> + </xs:annotation> + <xs:complexType mixed="true"> + <xs:sequence maxOccurs="unbounded"> + <xs:element ref="param" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="paragraph" minOccurs="0" + maxOccurs="unbounded" /> + <xs:element ref="word" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="char" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="snippet" minOccurs="0" maxOccurs="unbounded" /> + </xs:sequence> + <xs:attributeGroup ref="coreattrs" /> + <xs:attributeGroup ref="posattrs" /> + </xs:complexType> +</xs:element> +``` + +A **region** element of an HTX contains an optional sequence of **paragraph**, **line**, **word**, **char** and **snippet** elements and optional hidden text for a region. + +#### Attributes: + +Core and position attributes apply. + +#### Elements + +- **param** (zero or more) +Optional sequence of parameter elements may be used to specify user-defined properties for the region. +- **paragraph** (zero or more) +Optional sequence of elements containing hidden text for paragraphs in the region. +- **line** (zero or more) +Optional sequence of elements containing hidden text for lines in the region. +- **word** (zero or more) +Optional sequence of elements containing hidden text for words in the region. +- **char** (zero or more) +Optional sequence of elements containing hidden text for characters in the region. +- **snippet** (zero or more) +Optional sequence of elements each identifying an unrecognised portion of the raster. + +##### **Direct content** + +- Region level hidden text + +### **G.4.5 Paragraph** + +The **paragraph** element is declared as follows: + +``` +<xs:element name="paragraph"> + <xs:annotation> + <xs:documentation> + A paragraph element contains hidden text for a paragraph. + </xs:documentation> + </xs:annotation> + <xs:complexType mixed="true"> + <xs:sequence maxOccurs="unbounded"> + <xs:element ref="param" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="line" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="word" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="char" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="snippet" minOccurs="0" maxOccurs="unbounded" /> + </xs:sequence> + <xs:attributeGroup ref="coreattrs" /> + <xs:attributeGroup ref="posattrs" /> + </xs:complexType> +</xs:element> +``` + +A **paragraph** element of an HTX contains an optional sequence of **line**, **word**, **char** and **snippet** elements and optional hidden text for the paragraph. + +#### **Attributes:** + +Core and position attributes apply. + +#### **Elements** + +- **param** (zero or more) +Optional sequence of parameter elements may be used to specify user-defined properties for the paragraph. +- **line** (zero or more) +Optional sequence of elements containing hidden text for lines in the paragraph. +- **word** (zero or more) +Optional sequence of elements containing hidden text for words in the paragraph. +- **char** (zero or more) +Optional sequence of elements containing hidden text for characters in the paragraph. +- **snippet** (zero or more) +Optional sequence of elements each identifying an unrecognised portion of the raster. + +#### **Direct content** + +- Paragraph level hidden text + +### G.4.6 Line + +The **line** element is declared as follows: + +``` +<xs:element name="line"> + <xs:annotation> + <xs:documentation> + A line element contains hidden text for a line. + </xs:documentation> + </xs:annotation> + <xs:complexType mixed="true"> + <xs:sequence maxOccurs="unbounded"> + <xs:element ref="param" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="word" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="char" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="snippet" minOccurs="0" maxOccurs="unbounded" /> + </xs:sequence> + <xs:attributeGroup ref="coreattrs" /> + <xs:attributeGroup ref="posattrs" /> + </xs:complexType> +</xs:element> +``` + +A **line** element of an HTX contains an optional sequence of **word**, **char** and **snippet** elements and optional hidden text for a line. + +#### Attributes: + +Core and position attributes apply. + +#### Elements + +- **param** (zero or more) +Optional sequence of parameter elements may be used to specify user-defined properties for the line. +- **word** (zero or more) +Optional sequence of elements containing hidden text for words in the line. +- **char** (zero or more) +Optional sequence of elements containing hidden text for characters in the line. +- **snippet** (zero or more) +Optional sequence of elements each identifying an unrecognised portion of the raster. + +##### Direct content + +- Line level hidden text + +### G.4.7 Word + +The **word** element is declared as follows: + +``` +<xs:element name="word"> + <xs:annotation> + <xs:documentation> + A word element contains hidden text for a word. + </xs:documentation> + </xs:annotation> + <xs:complexType mixed="true"> + <xs:sequence maxOccurs="unbounded"> + <xs:element ref="param" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="char" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="snippet" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="altword" minOccurs="0" maxOccurs="unbounded" /> + </xs:sequence> + <xs:attribute name="conf" type="Percentage" /> + <xs:attributeGroup ref="coreattrs" /> + <xs:attributeGroup ref="posattrs" /> + </xs:complexType> +</xs:element> +``` + +A **word** element of an HTX contains an optional sequence of **char**, **altword** and **snippet** elements and optional hidden text for a word. + +#### Attributes: + +Core and position attributes apply. + +- **conf** (optional) + +An optional attribute indicating the confidence of the accuracy of the given word as a percentage in the range of 0% to 100%. + +#### Elements + +- **param** (zero or more) +Optional sequence of parameter elements may be used to specify user-defined properties for the word. +- **char** (zero or more) +Optional sequence of elements containing hidden text for characters in the word. +- **snippet** (zero or more) +Optional sequence of elements each identifying an unrecognised portion of the raster. +- **altword** (zero or more) +Optional sequence of elements containing hidden text for alternate words. It defines a possible alternative interpretation of the word in the raster image when uncertainties exist. + +#### Direct content + +- Word level hidden text + +### G.4.8 Alternative word + +The **altword** element contains alternative hidden text for a word and is declared as follows: + +``` +<xs:element name="altword"> + <xs:annotation> + <xs:documentation> + A altword element contains hidden text for a alternative word. + </xs:documentation> + </xs:annotation> + <xs:complexType mixed="true"> + <xs:sequence maxOccurs="unbounded"> + <xs:element ref="param" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="char" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="snippet" minOccurs="0" maxOccurs="unbounded" /> + </xs:sequence> + <xs:attribute name="conf" type="Percentage" /> + <xs:attributeGroup ref="coreattrs" /> + <xs:attributeGroup ref="posattrs" /> + </xs:complexType> +</xs:element> +``` + +An **altword** element of an HTX contains an optional sequence of **char** and **snippet** elements, and optional hidden text for an alternative word. + +#### **Attributes:** + +Core and position attributes apply. + +- **conf** (optional) + +An optional attribute indicating the confidence of the accuracy of the given alternate word as a percentage in the range of 0% to 100%. + +#### **Elements** + +- **param** (zero or more) + +Optional sequence of parameter elements may be used to specify user-defined properties for the alternate word. + +- **char** (zero or more) + +Optional sequence of elements containing hidden text for characters in the alternate word. + +- **snippet** (zero or more) + +Optional sequence of elements each identifying an unrecognised portion of the raster. + +#### **Direct content** + +- Word level hidden text specifying some alternative text. + +#### G.4.9 Character + +The **char** element contains a hidden text character and is declared as follows: + +``` +<xs:element name="char"> + <xs:annotation> + <xs:documentation> + A char element contains a hidden text character. + </xs:documentation> + </xs:annotation> + <xs:complexType mixed="true"> + <xs:sequence maxOccurs="unbounded"> + <xs:element ref="param" minOccurs="0" maxOccurs="unbounded" /> + <xs:element ref="altchar" minOccurs="0" maxOccurs="unbounded" /> + </xs:sequence> + <xs:attribute name="conf" type="Percentage" /> + <xs:attributeGroup ref="coreattrs" /> + <xs:attributeGroup ref="posattrs" /> + </xs:complexType> +</xs:element> +``` + +A **char** element of an HTX contains an optional sequence of **altchar** elements and an optional hidden text character. + +#### Attributes: + +Core and position attributes apply. + +- **conf** (optional) + +An optional attribute indicating the confidence of the accuracy of the given character as a percentage in the range of 0% to 100%. + +#### Elements + +- **param** (zero or more) + +Optional sequence of parameter elements may be used to specify user-defined properties for the character. + +- **altchar** (zero or more) + +Optional sequence of elements containing hidden text for alternate characters in the alternate word. This element may only occur directly after a char or altchar element. It defines a possible alternative interpretation of the character in the raster image when uncertainties exist. + +#### Direct content + +- Character level hidden text + +### G.4.10 Alternative character + +The **altchar** element is declared as follows: + +``` +<xs:element name="altchar"> + <xs:annotation> + <xs:documentation> + A altchar element contains a hidden text alternative character. + </xs:documentation> + </xs:annotation> + <xs:complexType mixed="true"> + <xs:sequence> + <xs:element ref="param" minOccurs="0" maxOccurs="unbounded" /> + </xs:sequence> + <xs:attribute name="conf" type="Percentage" /> + <xs:attributeGroup ref="coreattrs" /> + <xs:attributeGroup ref="posattrs" /> + </xs:complexType> +</xs:element> +``` + +An **altchar** element of an HTX contains an optional sequence of **snippet** elements and optional hidden text for an alternative character. + +#### Attributes: + +Core and position attributes apply. + +- **conf** (optional) + +An optional attribute indicating the confidence of the accuracy of the given alternate character as a percentage in the range of 0% to 100%. + +#### Elements + +- **param** (zero or more) + +Optional sequence of parameter elements may be used to specify user-defined properties for the alternate character. + +#### Direct content + +- Character level hidden text specifying an alternative character. + +### G.4.11 Snippet + +The **snippet** element is declared as follows: + +``` +<xs:element name="snippet"> + <xs:annotation> + <xs:documentation> + A snippet element identifies an unrecognised portion of the image. + </xs:documentation> + </xs:annotation> + <xs:complexType mixed="true"> + <xs:sequence minOccurs="0" maxOccurs="unbounded" > + <xs:element ref="param" /> + </xs:sequence> + <xs:attributeGroup ref="coreattrs" /> + <xs:attributeGroup ref="posattrs" /> + </xs:complexType> +</xs:element> +``` + +A **snippet** element of an HTX identifies an unrecognised portion of the image. + +#### Attributes: + +Core and position attributes apply. + +#### **Elements** + +- **param** (zero or more) + +Optional sequence of parameter elements may be used to specify user-defined properties for the snippet. + +#### **Direct content** + +- **none** + +### **G.4.12 Annotations** + +The **annotations** element is declared as follows: + +``` +<xs:element name="annotations"> + <xs:annotation> + <xs:documentation> +The annotations element represents annotated, clickable and highlighted areas +on a page. + </xs:documentation> + </xs:annotation> + <xs:complexType> + <xs:sequence maxOccurs="unbounded"> + <xs:element ref="area"/> + </xs:sequence> + <xs:attributeGroup ref="coreattrs" /> + </xs:complexType> +</xs:element> +``` + +An annotation element of an HTX contains a sequence of area elements defining clickable and/or highlighted areas as well as notes for a page. + +#### **Attributes:** + +Core attributes apply. + +#### **Elements** + +- **area** (at least one) + +Sequence of elements defining clickable and highlighted areas on a page. + +#### **Direct content** + +- **none** + +### **G.4.13 Area** + +The **area** element is declared as follows: + +``` +<xs:element name="area"> + <xs:annotation> + <xs:documentation> +An area element represents a clickable and/or highlighted area on a page. + </xs:documentation> + </xs:annotation> + <xs:complexType> + <xs:attribute name="href" type="xhtml:URI" /> + <xs:attribute name="alt" type="xhtml:Text" /> + <xs:attribute name="target" type="xhtml:URI" default="_self" /> + <xs:attribute name="shape" type="Shape" default="rect" /> + <xs:attribute name="coords" type="Coords" /> + <xs:attributeGroup ref="coreattrs" /> + </xs:complexType> +</xs:element> +``` + +An **area** element of an HTX defines a clickable and/or highlighted area on a page. To define a highlighted, non-clickable area the **href** attribute is to be omitted. + +#### **Attributes:** + +Core and position attributes apply. + +- **href** (optional) +URI of the hyperlink to use when the area is clicked. +- **alt** (optional) +An optional text descriptor for the hyperlink, possibly for use as a tooltip. Must not be used without the **href** attribute defined. +- **target** (optional) +The frame that the document the hyperlink points to should be displayed in (if the viewing program supports any kind of framing). Default is "\_self". See HTML 4.01 definition for further details. Must not be used without the **href** attribute defined. + +#### **Elements** + +- **none** + +#### **Direct content** + +- Notes for this area. + +# Annex H + +## Hidden text and annotations schema + +(This annex forms an integral part of this Recommendation | International Standard.) + +## H.1 XML schema + +The following URL references the XML schema for HTX: + +<http://www.jpeg.org/hiddentext/htx.xsd> + +This XML schema shall be referred to as the *Hidden Text XML Schema*. + +### H.1.1 Version and encoding + +The HTX schema uses XML 1.0 and UTF-8 encoding: + +``` +<?xml version="1.0" encoding="utf-8" ?> +``` + +### H.1.2 Schema + +The schema wrapper for HTX is declared as follows: + +``` +<xs:schema + id = "htx" + xmlns = "http://www.jpeg.org/hiddentext/htx" + xmlns:xs = "http://www.w3.org/2001/XMLSchema" + xmlns:xhtml = "http://www.w3.org/1999/xhtml" + targetNamespace = "http://www.jpeg.org/hiddentext/htx" + elementFormDefault = "qualified"> +``` + +The schema uses several types and elements from the XHTML 1.0 XML schema, and imports this schema as follows: + +``` +<xs:import + namespace = "http://www.w3.org/1999/xhtml" + schemaLocation = "http://www.w3.org/2002/08/xhtml/xhtml1-strict.xsd"> +</xs:import> +``` + +The following tag is used to close the HTX schema: + +``` +</xs:schema> +``` + +# Annex I + +## Hidden text and annotations examples + +(This annex does not form an integral part of this Recommendation | International Standard.) + +## I.1 Example 1 + +``` + +<?xml version="1.0" encoding="utf-8"?> +<?xml-stylesheet href="#style" type="text/css"?> +<htx xmlns + xmlns:xhtml = "http://www.w3.org/1999/xhtml" + xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" + xsi:schemaLocation = "http://www.jpeg.org/hiddenText/htx htx.xsd" + lang = "en" + dir = "ltr"> + + <!-- ***** --> + <!-- Hidden text and annotations optional xhtml header --> + <!-- ***** --> + + <xhtml:head lang="de" dir="ltr"> + <xhtml:title>Test Document Title</xhtml:title> + <xhtml:style type="text/css" media="Screen" + title="Style Sheet Name One" lang="de" dir="ltr" id="style"> + style { display: none; } + body, paragraph, line { display: block; } + word, altword, char, altchar, snippet { display: inline; } + body { font-family: Arial,sans-serif; } + altword, altchar { font-style: italic; color: grey; } + [class~="red"] { background-color: red; } + [class~="blue"] { color: blue; } + [class~="large"] { font-size: 150%; } + </xhtml:style> + </xhtml:head> + + <!-- ***** --> + <!-- Optional annotations for page --> + <!-- ***** --> + + <annotations> + <area shape="rect" coords="0, 10, 50, 200" alt="link somewhere" + href="http://some.where.com/there" class="red" /> + <area shape="poly" coords="23, 45, 0, 100, 90, 100" + alt="link to somewhere else" href="http://somewhere.else.org/" /> + </annotations> + + <!-- ***** --> + <!-- Object for hidden text in the page --> + <!-- ***** --> + + <hiddentext shape="rect" coords="0, 0, 100, 200"> + + <!-- Optional, user defined page level parameters --> + <param name="param1">abcd</param> + <!-- First, mandatory region --> + + <region shape="rect" coords="0, 0, 100, 100"> + Here is some region level hidden text. + + <!-- Optional region parameters --> + <param name="param2">efgh</param> + <paragraph shape="poly" + +``` + +``` + +coords="0, 0, 100, 0, 100, 50, 30, 50, 30, 60, 0, 60"> + Here is some paragraph level hidden text. + + <!-- Optional paragraph parameters --> + <param name="param3">ijkl</param> + <param name="param4">mnop</param> + + <line shape="rect" coords="0, 0, 100, 20" class="large" > + <word conf="70%"> + Word + <char conf="90%"> + c + <altchar conf="10%">o</altchar> + </char> + <char conf="80%"> + h + <altchar conf="12%">n</altchar> + <altchar conf="8%">k</altchar> + </char> + <altword conf="15%"> + Vordok + </altword> + <altword conf="5%"> + Wordoh + </altword> + </word> + <word> + Next + </word> + + Some line level hidden text. + </line> + +</paragraph> + +<line class="large blue"> + And some line level hidden text. +</line> + +</region> + +<!-- Second, optional region --> +<region> + <!-- ... --> +</region> + +</hiddentext> +</htx> + +``` + +## I.2 Example 2 + +This example shows three lines in Japanese language formatted within HTX. + +人々は、技術そのものではなく、 +その技術によって齎される機能や +性能に感動する。 + +``` +<paragraph angle="-90" baseline="90"> + <line shape="rect" coords="236, 20, 296, 854"> + <char conf="95%">人々は</char> + <char conf="70%">、 + <altchar conf="40%"> , </altchar> + </char> + <char conf="80%">技術</char> + <char conf="90%">そのものではなく</char> + <char conf="70%">、 + <altchar conf="40%"> , </altchar> + </char> + </line> + + <line shape="rect" coords="136, 20, 196, 888"> + <char conf="90%">その技術によって</char> + <char conf="70%">齎 + <altchar conf="50%"> 齎 </altchar> + </char> + <char conf="90%">される</char> + <char conf="80%">機能</char> + <char conf="90%">や</char> + </line> + + </line shape="rect" coords="36, 20, 96, 452"> + <word conf="80%"> + <char>性能</char> + </word> + <char conf="90%">に感動する</char> + <char conf="70%">。 + <altchar conf="50%"> . </altchar> + </char> + </line> +</paragraph> +``` + +## I.3 Example 3 + +This example shows an HTX that has been automatically generated from an OCR process' XML output by use of an extensible stylesheet language transformation (XSLT). It contains text formatting information and character confidences as provided by the OCR process. The included reference to HTX2HTML.xsl enables an automatic conversion of this HTX to HTML within a web browser that supports XSLT. + +![Logo of Egypt Travelling, featuring a stylized blue pyramid with a yellow sun rising behind it, and the text 'Egypt Travelling' below.](8df4b47ea3ab99d6b9dfb79edad57eb1_img.jpg) + +Logo of Egypt Travelling, featuring a stylized blue pyramid with a yellow sun rising behind it, and the text 'Egypt Travelling' below. + +## Booking confirmation + +Dear Customer, + +we want to inform you of your successful reservation. Your hotel is Pyramid View Resort, Giza. You booked a twin room from 3/7/2006 to 16/7/2006. +**Please arrive by 4 p.m. the first day.** + +In case of problems or questions, please feel free to call us: + +**++12 (34) ± 23 45 67** + +We wish you a great holiday! + +Best regards + +![Handwritten signature of Bob Bobby](dbf3ea362ea469475b8e07955c584a31_img.jpg) + Bob Bobby + +Figure I.1 – Example of a scanned document page + +``` +<?xml version="1.0" encoding="UTF-8"?> +<?xml-stylesheet href="HTX2HTML.xsl" type="text/xsl"?> +<htx xmlns="http://www.jpeg.org/hiddentext/htx" res="300" + xmlns:xhtml="http://www.w3.org/1999/xhtml" + xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" + xsi:schemaLocation="http://www.jpeg.org/hiddentext/htx htx.xsd"> +<xhtml:head lang="de" dir="ltr"> + <xhtml:title/> + <xhtml:style type="text/css" media="Screen" title="" lang="de" dir="ltr" id="style"> + style, param { display: none; } + body, paragraph, line { display: block; } + word, altword, char, altchar, snippet { display: inline; } + *.format-bold { font-weight:bold; } + *.format-italic { font-style:italic; } + *.format-subscript { vertical-align:sub; } + *.format-superscript { vertical-align:super; } + *.format-smallcaps { font-variant:small-caps; } + *.format-underline { text-decoration:underline; } + *.format-strikeout { text-decoration:line-through; } + *.format-ffTimes-New-Roman { font-family:Times New Roman; } + *.format-fs14 { font-size:14pt; } + *.format-ffArial { font-family:Arial; } +``` + +``` + + *.format-fs12 { font-size:12pt; } + *.format-color14942208 { color:rgb(0, 0, 228); } + *.format-fs32 { font-size:32pt; } + *.format-fs10 { font-size:10pt; } + </xhtml:style> +</xhtml:head> +<hiddentext> + <region shape="rect" coords="1744, 566, 2196, 634"> + <paragraph> + <line shape="rect" coords="1759, 578, 2179, 630"> + <word class="format-ffTimes-New-Roman format-fs14 "> + <char conf="100%" shape="rect" coords="1759, 579, 1793, 618">E</char> + <char conf="100%" shape="rect" coords="1798, 591, 1824, 630">g</char> + <char conf="100%" shape="rect" coords="1825, 592, 1854, 630">y</char> + <char conf="100%" shape="rect" coords="1855, 591, 1884, 630">p</char> + <char conf="100%" shape="rect" coords="1888, 582, 1905, 618">t</char> + <char conf="100%" shape="rect" coords="1905, 579, 1923, 618"> </char> + </word> + <word class="format-ffTimes-New-Roman format-fs14 "> + <char conf="100%" shape="rect" coords="1923, 579, 1958, 618">T</char> + <char conf="77%" shape="rect" coords="1962, 591, 1985, 618">r</char> + <char conf="100%" shape="rect" coords="1987, 591, 2013, 619">a</char> + <char conf="100%" shape="rect" coords="2016, 592, 2044, 619">v</char> + <char conf="100%" shape="rect" coords="2046, 591, 2068, 619">e</char> + <char conf="49%" shape="rect" coords="2071, 579, 2085, 618">l</char> + <char conf="49%" shape="rect" coords="2087, 579, 2101, 618">l</char> + <char conf="100%" shape="rect" coords="2103, 578, 2117, 618">i</char> + <char conf="100%" shape="rect" coords="2121, 591, 2150, 618">n</char> + <char conf="100%" shape="rect" coords="2153, 591, 2179, 630">g</char> + </word> + </line> + </paragraph> + </region> + <region shape="rect" coords="360, 832, 2052, 1758"> + <paragraph> + <line shape="rect" coords="379, 843, 888, 891"> + <word class="format-ffArial format-fs12 format-bold "> + <char conf="100%" shape="rect" coords="379, 844, 409, 880">B</char> + <char conf="100%" shape="rect" coords="413, 853, 440, 881">o</char> + <char conf="100%" shape="rect" coords="444, 853, 471, 881">o</char> + <char conf="100%" shape="rect" coords="475, 844, 499, 880">k</char> + <char conf="100%" shape="rect" coords="503, 844, 510, 880">i</char> + <char conf="100%" shape="rect" coords="517, 853, 541, 880">n</char> + <char conf="100%" shape="rect" coords="546, 853, 571, 891">g</char> + <char conf="100%" shape="rect" coords="571, 853, 591, 881"> </char> + </word> + <word class="format-ffArial format-fs12 format-bold "> + <char conf="100%" shape="rect" coords="591, 853, 615, 881">c</char> + <char conf="100%" shape="rect" coords="619, 853, 646, 881">o</char> + <char conf="100%" shape="rect" coords="650, 853, 674, 880">n</char> + <char conf="100%" shape="rect" coords="678, 843, 696, 880">f</char> + <char conf="100%" shape="rect" coords="698, 844, 705, 880">i</char> + <char conf="100%" shape="rect" coords="711, 853, 728, 880">r</char> + <char conf="100%" shape="rect" coords="731, 853, 770, 880">m</char> + <char conf="100%" shape="rect" coords="774, 853, 798, 881">a</char> + <char conf="100%" shape="rect" coords="801, 845, 816, 881">t</char> + <char conf="100%" shape="rect" coords="820, 844, 827, 880">i</char> + <char conf="100%" shape="rect" coords="833, 853, 860, 881">o</char> + <char conf="100%" shape="rect" coords="864, 853, 888, 880">n</char> + </word> + </line> + </paragraph> + </region> + +``` + +``` + +<line shape="rect" coords="379, 1015, 723, 1059"> + <word class="format-ffArial format-fs12 "> + <char conf="100%" shape="rect" coords="379, 1016, 408, 1052">D</char> + <char conf="84%" shape="rect" coords="413, 1025, 437, 1053">e</char> + <char conf="100%" shape="rect" coords="441, 1025, 464, 1053">a</char> + <char conf="100%" shape="rect" coords="470, 1025, 484, 1052">r</char> + <char conf="100%" shape="rect" coords="484, 1015, 500, 1052"> </char> + </word> + <word class="format-ffArial format-fs12 "> + <char conf="85%" shape="rect" coords="500, 1015, 531, 1053">C</char> + <char conf="100%" shape="rect" coords="537, 1026, 557, 1053">u</char> + <char conf="100%" shape="rect" coords="562, 1025, 584, 1053">s</char> + <char conf="100%" shape="rect" coords="587, 1017, 599, 1053">t</char> + <char conf="100%" shape="rect" coords="602, 1025, 626, 1053">o</char> + <char conf="100%" shape="rect" coords="631, 1025, 665, 1052">m</char> + <char conf="84%" shape="rect" coords="672, 1025, 696, 1053">e</char> + <char conf="100%" shape="rect" coords="701, 1025, 715, 1052">r</char> + <char conf="100%" shape="rect" coords="719, 1047, 723, 1059">,</char> + </word> +</line> +</paragraph> +<paragraph> + <line shape="rect" coords="375, 1130, 2036, 1178"> + <word class="format-ffArial format-fs12 "> + <char conf="100%" shape="rect" coords="375, 1141, 411, 1167">w</char> + <char conf="84%" shape="rect" coords="413, 1140, 437, 1168">e</char> + <char conf="84%" shape="rect" coords="437, 1140, 453, 1168"> </char> + </word> + <word class="format-ffArial format-fs12 "> + <char conf="100%" shape="rect" coords="453, 1141, 489, 1167">w</char> + <char conf="100%" shape="rect" coords="491, 1140, 514, 1168">a</char> + <char conf="100%" shape="rect" coords="521, 1140, 541, 1167">n</char> + <char conf="100%" shape="rect" coords="546, 1132, 558, 1168">t</char> + <char conf="100%" shape="rect" coords="558, 1132, 573, 1168"> </char> + </word> + <word class="format-ffArial format-fs12 "> + <char conf="100%" shape="rect" coords="573, 1132, 585, 1168">t</char> + <char conf="100%" shape="rect" coords="588, 1140, 612, 1168">o</char> + <char 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format-fs12 format-color14942208 format-bold "> + <char conf="100%" shape="rect" coords="1280, 1476, 1304, 1512">2</char> + <char conf="100%" shape="rect" coords="1309, 1476, 1333, 1513">3</char> + <char conf="100%" shape="rect" coords="1333, 1476, 1349, 1512"> </char> + </word> + <word class="format-ffArial format-fs12 format-color14942208 format-bold "> + <char conf="100%" shape="rect" coords="1349, 1476, 1375, 1512">4</char> + <char conf="100%" shape="rect" coords="1378, 1477, 1402, 1513">5</char> + <char conf="100%" shape="rect" coords="1402, 1476, 1420, 1513"> </char> + </word> + <word class="format-ffArial format-fs12 format-color14942208 format-bold "> + <char conf="100%" shape="rect" coords="1420, 1476, 1444, 1513">6</char> + <char conf="74%" shape="rect" coords="1448, 1477, 1471, 1512">7</char> + </word> +</line> +</paragraph> +<paragraph> + <line shape="rect" coords="376, 1591, 1009, 1638"> + <word class="format-ffArial format-fs12 "> + <char conf="100%" shape="rect" coords="376, 1591, 422, 1627">W</char> + <char conf="84%" shape="rect" coords="424, 1600, 448, 1628">e</char> + <char conf="84%" shape="rect" coords="448, 1600, 464, 1628"> </char> + </word> + <word class="format-ffArial format-fs12 "> + <char conf="100%" shape="rect" coords="464, 1601, 500, 1627">w</char> + <char conf="100%" shape="rect" coords="504, 1591, 508, 1627">i</char> + <char conf="100%" shape="rect" coords="512, 1600, 534, 1628">s</char> + <char conf="100%" shape="rect" coords="540, 1591, 560, 1627">h</char> + <char conf="100%" shape="rect" coords="560, 1591, 579, 1628"> </char> + </word> + <word class="format-ffArial format-fs12 "> + <char conf="100%" shape="rect" coords="579, 1601, 603, 1638">y</char> + <char conf="100%" shape="rect" coords="605, 1600, 629, 1628">o</char> + <char conf="100%" shape="rect" coords="635, 1601, 655, 1628">u</char> + <char conf="100%" shape="rect" coords="655, 1600, 674, 1628"> </char> + </word> + <word class="format-ffArial format-fs12 "> + <char conf="100%" shape="rect" coords="674, 1600, 697, 1628">a</char> + </word> + <word class="format-ffArial format-fs12 "> + <char conf="100%" shape="rect" coords="697, 1600, 716, 1628"> </char> + </word> + <word class="format-ffArial format-fs12 "> + <char conf="100%" shape="rect" coords="716, 1600, 739, 1638">g</char> + <char conf="100%" shape="rect" coords="745, 1600, 759, 1627">r</char> + <char conf="84%" shape="rect" coords="761, 1600, 785, 1628">e</char> + <char conf="100%" shape="rect" coords="788, 1600, 811, 1628">a</char> + <char conf="100%" shape="rect" coords="815, 1592, 827, 1628">t</char> + <char conf="100%" shape="rect" coords="827, 1591, 846, 1628"> </char> + </word> + <word class="format-ffArial format-fs12 "> + <char conf="100%" shape="rect" coords="846, 1591, 866, 1627">h</char> + <char conf="100%" shape="rect" coords="872, 1600, 896, 1628">o</char> + <char conf="100%" shape="rect" coords="902, 1591, 906, 1627">l</char> + <char conf="100%" shape="rect" coords="913, 1591, 917, 1627">i</char> + <char conf="100%" shape="rect" coords="922, 1591, 944, 1628">d</char> + <char conf="100%" shape="rect" coords="950, 1600, 973, 1628">a</char> + <char conf="100%" shape="rect" coords="976, 1601, 1000, 1638">y</char> + <char conf="100%" shape="rect" coords="1004, 1591, 1009, 1627">!</char> + </word> + </line> + +``` + +``` + + </paragraph> + <paragraph> + <line shape="rect" coords="379, 1706, 657, 1753"> + <word class="format-ffArial format-fs12 "> + <char conf="88%" shape="rect" coords="379, 1706, 405, 1742">B</char> + <char conf="84%" shape="rect" coords="410, 1715, 434, 1743">e</char> + <char conf="100%" shape="rect" coords="437, 1715, 459, 1743">s</char> + <char conf="100%" shape="rect" coords="462, 1707, 474, 1743">t</char> + <char conf="100%" shape="rect" coords="474, 1707, 492, 1743"> </char> + </word> + <word class="format-ffArial format-fs12 "> + <char conf="100%" shape="rect" coords="492, 1715, 506, 1742">r</char> + <char conf="84%" shape="rect" coords="508, 1715, 532, 1743">e</char> + <char conf="100%" shape="rect" coords="535, 1715, 558, 1753">g</char> + <char conf="100%" shape="rect" coords="563, 1715, 586, 1743">a</char> + <char conf="100%" shape="rect" coords="592, 1715, 606, 1742">r</char> + <char conf="100%" shape="rect" coords="608, 1706, 630, 1743">d</char> + <char conf="100%" shape="rect" coords="635, 1715, 657, 1743">s</char> + </word> + </line> + </paragraph> + </region> + <region shape="rect" coords="364, 1862, 830, 2018"> + <paragraph> + <line shape="rect" coords="380, 1892, 814, 2014"> + <word class="format-ffTimes-New-Roman format-fs32 format-bold format-italic "> + <char conf="1%" shape="rect" coords="380, 1892, 412, 1978">1</char> + <char conf="15%" shape="rect" coords="402, 1894, 460, 1986">2</char> + <char conf="100%" shape="rect" coords="450, 1914, 570, 1994">^</char> + <char conf="28%" shape="rect" coords="586, 1906, 628, 2002">!</char> + <char conf="100%" shape="rect" coords="610, 1908, 814, 2014">^</char> + </word> + </line> + </paragraph> + </region> + <region shape="rect" coords="362, 2028, 596, 2080"> + <paragraph> + <line shape="rect" coords="378, 2036, 579, 2075"> + <word class="format-ffArial format-fs10 "> + <char conf="100%" shape="rect" coords="378, 2036, 401, 2066">B</char> + <char conf="100%" shape="rect" coords="404, 2043, 425, 2067">o</char> + <char conf="100%" shape="rect" coords="429, 2036, 448, 2067">b</char> + <char conf="100%" shape="rect" coords="448, 2036, 464, 2067"> </char> + </word> + <word class="format-ffArial format-fs10 "> + <char conf="100%" shape="rect" coords="464, 2036, 487, 2066">B</char> + <char conf="100%" shape="rect" coords="490, 2043, 511, 2067">o</char> + <char conf="100%" shape="rect" coords="515, 2036, 534, 2067">b</char> + <char conf="100%" shape="rect" coords="538, 2036, 557, 2067">b</char> + <char conf="100%" shape="rect" coords="559, 2044, 579, 2075">y</char> + </word> + </line> + </paragraph> + </region> +</hiddentext> +</htx> + +``` + +The following XSLT can be used to translate HTX for viewing in a web browser. It is not the intention of the HTX to replace the original image. Translation to HTML might be used to review the OCR results, or to help in creating JPM viewers that provide copy and paste operations of the hidden text underneath the page image. + +``` +<?xml version="1.0" encoding="ISO-8859-1"?> +<!-- + XSL Script for translating from HTX to HTML. + + Tested with + - Xalan-C++ 1.10.0 + - Internet Explorer 6 + - Mozilla Firefox 1.5 + + Author: Andreas Hirth, LuraTech Imaging GmbH, www.luratech.com + + Todo: + - supporting polygonic bounding shapes + + Note: + - altchar and altword are skipped + - absolute positioning is used for every element with coordinates +--> + +<xsl:stylesheet version="1.0" + xmlns:xsl="http://www.w3.org/1999/XSL/Transform" + xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" + xmlns:xhtml="http://www.w3.org/1999/xhtml" + xmlns:xalan="http://xml.apache.org/xalan" + xmlns:htx="http://www.jpeg.org/hidden-text/htx" + exclude-result-prefixes="xsl xsi xhtml xalan htx"> + + <xsl:output method="html" indent="yes" xalan:indent-amount="4"/> + + <!-- Make the character enclosing <span> tags be written without linebreak + or whitespaces in between. This is important because the browser will put + a blank between each character otherwise. --> + <xsl:strip-space elements="*" /> + + <!-- Make a <title> tag from a xhtml <title> tag --> + <xsl:template match="xhtml:head/xhtml:title"> + <title><xsl:value-of select="text()" /> + + + + + + + + + + + + + + + + + + + + + + + + +``` + +``` + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Polygonic shapes are not supported yet. No positioning attributes are +written for element <>. + + + + + + + + + + + + Polygonic shapes are not supported yet. No positioning attributes are +written for element + + + + + + + + + + + + + + + + + + + + + + + + + +``` + +``` + + + + 0 + + + + + + + + + + + + + + + + 0 + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +``` + +``` + + + 0 + + + + + + + + + + + + + + + + + 0 + + + + + + in + px + + + position:absolute; left:; top:; + + + + + + + + + + + + + + + + + + + 0 + + + + + + +``` + +``` + + + + + + + + + + + + 0 + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + 0 + + + + + + + +``` + +``` + + + + + + + + + + + + + + + + + 0 + + + + + + + + + in + px + + + position:absolute; left:; top:; + + + + +``` + +# Annex J + +## **Guidelines for constructing URLs for JPM files** + +(This annex does not form an integral part of this Recommendation | International Standard.) + +This informative annex describes how to construct URLs that reference sub-elements of a JPM file. These sub-elements may be pages, images or metadata boxes. These conventions may be used when creating links within a JPM file or when linking to an interior element of a JPM file from a web page. When a decoding application receives such a request, it should render only the requested portion of a JPM file. + +Rec. ITU-T T.808 | ISO/IEC 15444-9 will define further how to remotely access JPM files. Implementers should refer to Rec. ITU-T T.808 | ISO/IEC 15444-9 for additional guidance on constructing URLs. + +These URLs are constructed by appending a question mark ("?") character to the path and file name of the JPM file and then appending attribute value pairs joined by equal signs ("="), separated by ampersands("&"), that identify the sub-element for which access is desired. + +## **J.1 Pages and layout objects** + +This shows how to reference a single layout object on a given page via its LObjID. + +**foo.jpm?page=3&obj=32** + +page=3 is a page reference + +obj=32 is a layout object reference to a layout object on page 3 + +## **J.2 Metadata boxes** + +Metadata boxes may be referred to in a URL containing a JPM file. In this case, the XML metadata from that level of the JPM file (whether page level, page collection level, or layout object level) is returned to the requester of the URL rather than any image data. + +**foo.jpm?page=43&type=meta** + +In cases where more than one metadata box occurs at the same level of a JPM file, an index parameter is used to select which metadata box is to be used. "index=1" refers to the first such metadata box. If no "index=" parameter is used, yet multiple metadata boxes exist at that level, the first metadata box is used. + +**foo.jpm?page=77&obj=19&type=meta&index=1** + +If the metadata box is an XML box, the metadata is of MIME type XML. If the metadata box is a UUID box, the type may or may not be XML. The "mtype=" parameter can be used to identify the type of the data using standard MIME type identification strings. If no "mtype=" parameter is used, the mtype is presumed to be XML. + +**foo.jpm?page=91&type=meta&mtype=text** + +## **J.3 Labels** + +Label boxes may be used in a JPM file to attach labels to other boxes in the file. Metadata, such as an XML box for example, may also be attached to these same boxes. In such a case, the metadata is returned to the requester of the URL rather than any image data. XHTML pages may occur inside an XML box, since they represent valid XML data. + +**foo.jpm?label=album.html** + +**foo.jpm?label=IPR-info&type=meta&index=2** + +## J.4 Page collections + +Page collection boxes may contain an optional label box. This label may be used to refer to a page collection in a URL. Every JPM file has a main page collection. Even if it contains no label, the main page collection may be referred to by the reserved label "main". If the "coll=" parameter is omitted, then any page referred to is presumed to be locatable in the main page collection. The behaviour of the decoder here is undefined. It may wish to provide a textual list of page labels of the pages in the collection, or it may wish to show the page thumbnails of the pages in the collection, or both. + +**foo.jpm?coll=toc** + +**foo.jpm?coll=main** + +**foo.jpm?coll=list-of-figs** + +**foo.jpm?coll=list-of-tables foo.jpm?coll=toc&page=31 foo.jpm?coll=main&page=7** + +**foo.jpm?page=7** + +**foo.jpm?** + +## J.5 Page thumbnails + +Each page may have an optional thumbnail. The "type=thumb" parameter value is used to specify the thumbnail for a page rather than the page itself. The "type=img" parameter value is used to specify the page itself is to be rendered, rather than the thumbnail. + +**foo.jpm?page=3&type=img** + +**foo.jpm?page=3&type=thumb** + +## J.6 Document thumbnail + +Every JPM file may have at most one optional document thumbnail. The reserved page label "thumb" gets and displays the document thumbnail even if no label box is used to label the document thumbnail image. + +**foo.jpm?page=thumb** + +## J.7 Byte ranges + +A byte range within a JPM file may be specified for processing by the decoder. The behaviour of the decoder then depends on what box types are located within the byte range. The "off=" parameter is used to specify an offset in bytes from the beginning of the file. The "len=" parameter is used to specify a number of bytes to be returned. This is not a very reliable method of getting to sub-elements of a JPM file, since they may be moved and re-arranged as the file grows or changes. Better methods are provided above for this purpose. If, however, the decoder has already received enough information from the file in question to know where a sub-element of interest is located, then this is a useful method. This method may also be useful to retrieve a small amount of data from the front of the file in order for the decoder to better understand the organization of the file. + +**foo.jpm?off=12384&len=1024** + + + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|---------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git 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b/marked/T/T-REC-T.812-200708-I_PDF-E/raw.md @@ -0,0 +1,2356 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# T.812 + +(08/2007) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES +Still-image compression – JPEG 2000 + +--- + +**Information technology – JPEG 2000 image +coding system: An entry level JPEG 2000 +encoder** + +ITU-T Recommendation T.812 + +![ITU logo](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with a red lightning bolt striking it, and the text 'ITU' in blue, with 'International Telecommunication Union' in smaller blue text below it. + +ITU logo + + + +# **Information technology – JPEG 2000 image coding system:** **An entry level JPEG 2000 encoder** + +## **Summary** + +The purpose of ITU-T Rec. T.812 | ISO/IEC 15444-13 is to define a normative entry level JPEG 2000 encoder providing one or more optional complete encoding paths that use various features defined in the JPEG 2000 specifications. This Recommendation | International Standard provides for an entry-level encoder that can be used in various applications with guidelines on its use, based on patents for which royalty and license fee free declarations are available. + +This Recommendation | International Standard defines a set of lossless (bit-preserving) and lossy compression methods for coding bi-level, continuous-tone greyscale, palletized colour, or continuous-tone colour digital still images. + +## **Source** + +ITU-T Recommendation T.812 was approved on 29 August 2007 by ITU-T Study Group 16 (2005-2008) under the ITU-T Recommendation A.8 procedure. An identical text is also published as ISO/IEC 15444-13. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2008 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## CONTENTS + +| | Page | +|--------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 1.1 Context ..... | 1 | +| 1.2 Requirements ..... | 1 | +| 2 References ..... | 1 | +| 2.1 Identical Recommendations International Standards ..... | 1 | +| 3 Definitions ..... | 2 | +| 4 Abbreviations and symbols ..... | 5 | +| 4.1 Abbreviations ..... | 5 | +| 4.2 Symbols ..... | 5 | +| 5 General description ..... | 6 | +| 5.1 Codestream ..... | 6 | +| 5.2 Coding principles ..... | 6 | +| 6 Encoder requirements ..... | 8 | +| 6.1 General ..... | 8 | +| 6.2 Encoder function definition ..... | 8 | +| 6.3 Implementation ..... | 12 | +| 6.4 Codestream description ..... | 13 | +| 7 Optional file format requirements ..... | 13 | +| Annex A – Codestream syntax ..... | 14 | +| Annex B – Image and compressed image data ordering ..... | 15 | +| Annex C – Arithmetic entropy coding ..... | 16 | +| C.1 Binary encoding ..... | 16 | +| C.2 Description of the arithmetic encoder ..... | 17 | +| Annex D – Coefficient bit modelling ..... | 25 | +| D.1 Code-block scan pattern within code-blocks ..... | 25 | +| D.2 Coefficient bits and significance ..... | 25 | +| D.3 Encoding passes over the bit-planes ..... | 26 | +| D.4 Initializing and terminating ..... | 29 | +| D.5 Error resilience segmentation symbol ..... | 31 | +| D.6 Selective arithmetic coding bypass ..... | 31 | +| D.7 Vertically causal context formation ..... | 32 | +| D.8 Flow diagram of the code-block coding ..... | 32 | +| Annex E – Quantization ..... | 35 | +| E.1 Inverse quantization procedure (Informative) ..... | 35 | +| E.2 Scalar coefficient quantization ..... | 36 | +| Annex F – Discrete wavelet transformation of tile-components ..... | 37 | +| F.1 Tile-component parameters ..... | 37 | +| F.2 Discrete wavelet transformations ..... | 37 | +| F.3 Forward transformation ..... | 37 | +| F.4 Sub-sampling of components ..... | 45 | +| F.5 Visual frequency weighting ..... | 45 | +| Annex G – DC level shifting and multiple component transformations ..... | 48 | +| G.1 DC level shifting of tile-components ..... | 48 | +| G.2 Forward reversible multiple component transformation (RCT) ..... | 48 | +| G.3 Forward irreversible multiple component transformation (ICT) ..... | 49 | +| G.4 Chrominance component sub-sampling and the reference grid ..... | 49 | +| Annex H – Coding of images with regions of interest ..... | 50 | +| H.1 Description of the Maxshift method ..... | 50 | +| H.2 Remarks on region of interest coding ..... | 51 | +| Annex I – JP2 file format syntax ..... | 53 | + + + +## **INTERNATIONAL STANDARD ITU-T RECOMMENDATION** + +# **Information technology – JPEG 2000 image coding system: An entry level JPEG 2000 encoder** + +# **1 Scope** + +This Recommendation | International Standard was developed by the Joint Photographic Experts Group (JPEG), the joint ISO/I–TU committee responsible for developing standards for continuous-tone still picture coding. It also refers to the Recommendations | International Standards produced by this committee: ITU-T Rec. T.81 | ISO/IEC 10918-1, ITU-T Rec. T.83 | ISO/IEC 10918-2, ITU-T Rec. T.84 | ISO/IEC 10918-3 and ITU-T Rec. T.87 | ISO/IEC 14495-1. + +## **1.1 Context** + +This Recommendation | International Standard defines a set of lossless (bit-preserving) and lossy compression methods for coding bi-level, continuous-tone greyscale, palletized colour, or continuous-tone colour digital still images. This Recommendation | International Standard: + +- specifies normative but optional encoding processes for converting source image data to JPEG 2000 compressed image data; +- specifies a complete encoding path to produce a conforming codestream as defined in Part 1 Annex A (ITU-T Rec. T.800 | ISO/IEC 15444-1); +- provides guidance on encoding processes for converting source image data to compressed image data; +- provides guidance on how to implement these processes in practice. + +## **1.2 Requirements** + +This subclause contains a list of requirements for the definitions of an entry-level encoder. + +An entry-level JPEG 2000 encoder implementation (this Recommendation | International Standard): + +- shall be normative but optional; implementers shall be allowed to select necessary technologies/paths that would suite their application needs; +- shall define a JPEG 2000 Part 1 codestream encoder implementation; should define a JP2 file format encoder implementation; +- shall define a complete encoding path to produce a conforming codestream as defined in Annex A of ITU-T Rec. T.800 | ISO/IEC 15444-1:2004; +- shall consist of technology with clear IP status being royalty fee-free. + +# **2 References** + +The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations. + +## **2.1 Identical Recommendations | International Standards** + +- ITU-T Recommendation T.81 (1992) | ISO/IEC 10918-1:1994, *Information technology – Digital compression and coding of continuous-tone still images: Requirements and guidelines.* +- ITU-T Recommendation T.84 (1996) | ISO/IEC 10918-3:1997, *Information technology – Digital compression and coding of continuous-tone still images: Extensions.* + +- ITU-T Recommendation T.86 (1998) | ISO/IEC 10918-4:1999, *Information technology – Digital compression and coding of continuous-tone still images: Registration of JPEG Profiles, SPIFF Profiles, SPIFF Tags, SPIFF Colour Spaces, APPn Markers, SPIFF Compression Types and Registration Authorities (REGAUT)*. +- ITU-T Recommendation T.87 (1998) | ISO/IEC 14495-1:2000, *Information technology – Lossless and near-lossless compression of continuous-tone still images – Baseline*. +- ITU-T Recommendation T.88 (2000) | ISO/IEC 14492:2001, *Information technology – Lossy/lossless coding of bi-level images*. +- ITU-T Recommendation T.800 (2002) | ISO/IEC 15444-1:2004, *Information technology – JPEG 2000 image coding system: Core coding system*. +- ITU-T Recommendation T.801 (2002) | ISO/IEC 15444-2:2004, *Information technology – JPEG 2000 image coding system: Extensions*. +- ITU-T Recommendation T.803 (2002) | ISO/IEC 15444-4:2004, *Information technology – JPEG 2000 image coding system: Conformance testing*. +- ITU-T Recommendation T.804 (2002) | ISO/IEC 15444-5:2003, *Information technology – JPEG 2000 image coding system: Reference software*. + +# 3 Definitions + +For the purposes of this Recommendation | International Standard, the following definitions apply. The definitions defined in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004 clause 3 also apply to this Recommendation | International Standard. + +**3.1 5-3 reversible filter (5-3R):** A particular filter pair used in the wavelet transformation. This reversible filter pair has 5 taps in the low-pass and 3 taps in the high-pass. + +**3.2 9-7 irreversible filter (9-7I):** A particular filter pair used in the wavelet transformation. This irreversible filter pair has 9 taps in the low-pass and 7 taps in the high-pass. + +**3.3 arithmetic coder:** An entropy coder that converts variable length strings to variable length codes (encoding) and visa versa (decoding). + +**3.4 bit-plane:** A two-dimensional array of bits. In this Recommendation | International Standard, a bit-plane refers to all the bits of the same magnitude in all coefficients or samples. This could refer to a bit-plane in a component, tile-component, code-block, region of interest, or other. + +**3.5 bit stream:** The actual sequence of bits resulting from the coding of a sequence of symbols. It does not include the markers or marker segments in the main and tile-part headers or the EOC marker. It does include any packet headers and in stream markers and marker segments not found within the main or tile-part headers. + +**3.6 channel:** One logical component of the image. A channel may be a direct representation of one component from the codestream, or may be generated by the application of a palette to a component from the codestream. + +**3.7 cleanup pass:** A coding pass performed on a single bit-plane of a code-block of coefficients. The first pass and only coding pass for the first significant bit-plane is a cleanup pass; the third and the last pass of every remaining bit-plane is a cleanup pass. + +**3.8 codestream:** A collection of one or more bit streams and the main header, tile-part headers, and the EOC required for their decoding and expansion into image data. This is the image data in a compressed form with all of the signalling needed to decode. + +**3.9 code-block:** A rectangular grouping of coefficients from the same sub-band of a tile-component. + +**3.10 coder:** An embodiment of either an encoding or decoding process. + +**3.11 coding pass:** A complete pass through a code-block where the appropriate coefficient values and context are applied. There are three types of coding passes: significance propagation pass, magnitude refinement pass and cleanup pass. The result of each pass (after arithmetic coding, if selective arithmetic coding bypass is not used) is a stream of compressed image data. + +**3.12 coefficient:** The values that are the result of a transformation. + +**3.13 component:** A two-dimensional array of samples. An image typically consists of several components, for instance representing red, green and blue. + +- 3.14 context:** Function of coefficients previously decoded and used to condition the decoding of the present coefficient. +- 3.15 decoder:** An embodiment of a decoding process, and optionally a colour transformation process. +- 3.16 decoding process:** A process which takes as its input all or part of a codestream and outputs all or part of a reconstructed image. +- 3.17 decomposition level:** A collection of wavelet sub-bands where each coefficient has the same spatial impact or span with respect to the source component samples. These include the HL, LH, and HH sub-bands of the same two dimensional sub-band decomposition. For the last decomposition level, the LL sub-band is also included. +- 3.18 discrete wavelet transformation (DWT):** A transformation that iteratively transforms one signal into two or more filtered and decimated signals corresponding to different frequency bands. This transformation operates on spatially discrete samples. +- 3.19 encoder:** An embodiment of an encoding process. +- 3.20 encoding process:** A process, that takes as its input all or part of a source image data and outputs a codestream. +- 3.21 file format:** A codestream and additional support data and information not explicitly required for the decoding of codestream. Examples of such support data include text fields providing titling, security and historical information, data to support placement of multiple codestream within a given data file, and data to support exchange between platforms or conversion to other file formats. +- 3.22 guard bits:** Additional most significant bits that have been added to sample data. +- 3.23 header:** Either a part of the codestream that contains only markers and marker segments (main header and tile part header) or the signalling part of a packet (packet header). +- 3.24 image area:** A rectangular part of the reference grid, registered by offsets from the origin and the extent of the reference grid. +- 3.25 image area offset:** The number of reference grid points down and to the right of the reference grid origin where the origin of the image area can be found. +- 3.26 irreversible:** A transformation, progression, system, quantization, or other process that, due to systemic or quantization error, disallows lossless recovery. An irreversible process can only lead to lossy compression. +- 3.27 JP2 file:** The name of a file in the file format described in this Recommendation | International Standard. Structurally, a JP2 file is a contiguous sequence of boxes. +- 3.28 JPEG:** Used to refer globally to the encoding and decoding process of the following Recommendations | International Standards: +- ITU-T Recommendation T.81 (1992) | ISO/IEC 10918-1:1994, *Information technology – Digital compression and coding of continuous-tone still images: Requirements and guidelines.* + - ITU-T Recommendation T.83 (1994) | ISO/IEC 10918-2:1995, *Information technology – Digital compression and coding of continuous-tone still images: Compliance testing.* + - ITU-T Recommendation T.84 (1996) | ISO/IEC 10918-3:1997, *Information technology – Digital compression and coding of continuous-tone still images: Extensions, plus Amendment 1 (1999), Provisions to allow registration of new compression types and versions in the SPIFF header.* + - ITU-T Recommendation T.86 (1998) | ISO/IEC 10918-4:1999, *Information technology – Digital compression and coding of continuous-tone still images: Registration of JPEG Profiles, SPIFF Profiles, SPIFF Tags, SPIFF Colour Spaces, APPn Markers, SPIFF Compression Types and Registration Authorities (REGAUT).* +- 3.29 JPEG 2000:** Used to refer globally to the encoding and decoding processes in this Recommendation | International Standard and their embodiment in applications. +- 3.30 JPX file:** JPEG 2000 File Format defined in ITU-T Rec. T.801 | ISO/IEC 15444-2:2004; JPEG 2000 File Format Extended. +- 3.31 layer:** A collection of compressed image data from coding passes of one, or more, code-blocks of a tile component. Layers have an order for encoding and decoding that must be preserved. +- 3.32 lossless:** A descriptive term for the effect of the overall encoding and decoding processes in which the output of the decoding process is identical to the input to the encoding process. Distortion free restoration can be assured. All of the coding processes or steps used for encoding and decoding are reversible. + +- 3.33 lossy:** A descriptive term for the effect of the overall encoding and decoding processes in which the output of the decoding process is not identical to the input to the encoding process. There is distortion (measured mathematically). At least one of the coding processes or steps used for encoding and decoding is irreversible. +- 3.34 magnitude refinement pass:** A type of coding pass. +- 3.35 main header:** A group of markers and marker segments at the beginning of the codestream that describe the image parameters and coding parameters that can apply to every tile and tile-component. +- 3.36 marker:** A two-byte code in which the first byte is hexadecimal FF (0xFF) and the second byte is a value between 1 (0x01) and hexadecimal FE (0xFE). +- 3.37 marker segment:** A marker and associated (not empty) set of parameters. +- 3.38 packet:** A part of the bit stream comprising a packet header and the compressed image data from one layer of one precinct of one resolution level of one tile-component. +- 3.39 packet header:** Portion of the packet that contains signalling necessary for decoding that packet. +- 3.40 precinct:** A one rectangular region of a transformed tile-component, within each resolution level, used for limiting the size of packets. +- 3.41 precision:** Number of bits allocated to a particular sample, coefficient, or other binary numerical representation. +- 3.42 progression:** The order of a codestream where the decoding of each successive bit contributes to a "better" reconstruction of the image. What metrics make the reconstruction "better" is a function of the application. Some examples of progression are increasing resolution or improved sample fidelity. +- 3.43 quantization:** A method of reducing the precision of the individual coefficients to reduce the number of bits used to entropy-code them. This is equivalent to division while compressing and multiplying while decompressing. Quantization can be achieved by an explicit operation with a given quantization value or by dropping (truncating) coding passes from the codestream. +- 3.44 reference grid:** A regular rectangular array of points used as a reference for other rectangular arrays of data. Examples include components and tiles. +- 3.45 region of interest (ROI):** A collections of coefficients that are considered of particular relevance by some user-defined measure. +- 3.46 resolution level:** Equivalent to decomposition level with one exception: the LL sub-band is also a separate resolution level. +- 3.47 reversible:** A transformation, progression, system, or other process that does not suffer systemic or quantization error and, therefore, allows lossless signal recovery. +- 3.48 segmentation symbol:** A special symbol coded with a uniform context at the end of each coding pass for error resilience. +- 3.49 selective arithmetic coding bypass:** A coding style where some of the code-block passes are not coded by the arithmetic coder. Instead the bits to be coded are appended directly to the bit stream without coding. +- 3.50 significance propagation pass:** A coding pass performed on a single bit-plane of a code-block of coefficients. +- 3.51 sub-band:** A group of transform coefficients resulting from the same sequence of low-pass and high-pass filtering operations, both vertically and horizontally. +- 3.52 tile:** A rectangular array of points on the reference grid, registered with and offset from the reference grid origin and defined by a width and height. The tiles that overlap are used to define tile-components. +- 3.53 tile-component:** All the samples of a given component in a tile. +- 3.54 tile index:** The index of the current tile ranging from zero to the number of tiles minus one. +- 3.55 tile-part:** A portion of the codestream with compressed image data for some, or all, of a tile. The tile-part includes at least one, and up to all, of the packets that make up the coded tile. +- 3.56 tile-part header:** A group of markers and marker segments at the beginning of each tile-part in the codestream that describe the tile-part coding parameters. + +**3.57 tile-part index:** The index of the current tile-part ranging from zero to the number of tile-parts minus one in a given tile. + +**3.58 transformation:** A mathematical mapping from one signal space to another. + +# 4 Abbreviations and symbols + +## 4.1 Abbreviations + +For the purposes of this Recommendation | International Standard, the following abbreviations apply. The abbreviations defined in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004 clause 4 also apply to this Recommendation | International Standard. + +| | | +|--------|-------------------------------------------------| +| 1D-DWT | One-dimensional Discrete Wavelet Transformation | +| FDWT | Forward Discrete Wavelet Transformation | +| ICC | International Colour Consortium | +| ICT | Irreversible Component Transformation | +| IDWT | Inverse Discrete Wavelet Transformation | +| JPEG | Joint Photographic Experts Group | +| JURA | JPEG Utilities Registration Authority | +| RCT | Reversible Component Transformation | +| ROI | Region of Interest | + +## 4.2 Symbols + +For the purposes of this Recommendation | International Standard, the following symbols apply. The abbreviations defined in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004 clause 4 also apply to this Recommendation | International Standard. + +| | | +|--------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 0x---- | Denotes a hexadecimal number | +| \nnn | A three-digit number preceded by a backslash indicates the value of a single byte within a character string, where the three digits specify the octal value of that byte | +| $\epsilon_b$ | Exponent of the quantization value for a sub-band defined in QCD and QCC | +| $\mu_b$ | Mantissa of the quantization value for a sub-band defined in QCD and QCC | +| $M_b$ | Maximum number of bit-planes coded in a given code-block | +| $N_L$ | Number of decomposition levels as defined in COD and COC | +| $R_b$ | Dynamic range of a component sample as defined in SIZ | +| COC | Coding style component marker | +| COD | Coding style default marker | +| COM | Comment marker | +| CRG | Component registration marker | +| EOC | End of codestream marker | +| EPH | End of packet header marker | +| PLM | Packet length, main header marker | +| PLT | Packet length, tile-part header marker | +| POC | Progression order change marker | +| PPM | Packed packet headers, main header marker | +| PPT | Packed packet headers, tile-part header marker | +| QCC | Quantization component marker | +| QCD | Quantization default marker | +| RGN | Region-of-interest marker | +| SIZ | Image and tile size marker | + +| | | +|-----|----------------------------| +| SOC | Start of codestream marker | +| SOD | Start of data marker | +| SOP | Start of packet marker | +| SOT | Start of tile-part marker | +| TLM | Tile-part lengths marker | + +# 5 General description + +## 5.1 Codestream + +The definition of codestream is the same as in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004. + +## 5.2 Coding principles + +The main procedures for this Recommendation | International Standard are shown in Figure 1. This shows the encoding order, a reverse ordering of the block diagram of Figure 5-1 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004. + +![Figure 1 – Specification block diagram. This block diagram illustrates the encoding process. On the left, 'Source image' is indicated by an arrow pointing into the process. The main flow consists of several sequential blocks: 'DC level shift, component transformation (Annex G)', 'Transformation (Annex F)', 'Quantization (Annex E)', 'Coefficient bit modelling (Annex D)', 'Arithmetic coding (Annex C)', and 'Data ordering (Annex B)'. Above this main flow is a large block labeled 'Codestream syntax (Annex A)', which has arrows pointing down to each of the six main processing blocks. Between the 'Transformation' and 'Quantization' blocks is a smaller block labeled 'ROI (Annex H)', with an arrow pointing down to the 'Quantization' block. Below the main flow is a block labeled 'File format (optional, Annex I)', with an arrow pointing up to the 'Data ordering' block. On the right, an arrow labeled 'Codestream' points away from the 'Data ordering' block. The diagram is identified by the code 'T.812(07)_F-01' in the bottom right corner.](853f59c89931a666c07903b31d098277_img.jpg) + +Figure 1 – Specification block diagram. This block diagram illustrates the encoding process. On the left, 'Source image' is indicated by an arrow pointing into the process. The main flow consists of several sequential blocks: 'DC level shift, component transformation (Annex G)', 'Transformation (Annex F)', 'Quantization (Annex E)', 'Coefficient bit modelling (Annex D)', 'Arithmetic coding (Annex C)', and 'Data ordering (Annex B)'. Above this main flow is a large block labeled 'Codestream syntax (Annex A)', which has arrows pointing down to each of the six main processing blocks. Between the 'Transformation' and 'Quantization' blocks is a smaller block labeled 'ROI (Annex H)', with an arrow pointing down to the 'Quantization' block. Below the main flow is a block labeled 'File format (optional, Annex I)', with an arrow pointing up to the 'Data ordering' block. On the right, an arrow labeled 'Codestream' points away from the 'Data ordering' block. The diagram is identified by the code 'T.812(07)\_F-01' in the bottom right corner. + +**Figure 1 – Specification block diagram** + +Procedures are presented in the annexes. The category of the annexes is the same as in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004. Also the index of the annex is the same. + +The coding process is summarized below. + +Many images have multiple components. This Specification has a multiple component transformation to correlate three components. This is the only function in this Specification that relates components to each other. (See Annex G.) + +The image components may be divided into tiles. These tile-components are rectangular arrays that relate to the same portion of each of the components that make up the image. Thus, tiling of the image actually creates tile-components that can be encoded independently of each other. This tile independence provides one of the methods for encoding a region of the image. (See Annex B.) + +The tile-components are composed into different decomposition levels using a wavelet transformation. These decomposition levels contain a number of sub-bands populated with coefficients that describe the horizontal and vertical spatial frequency characteristics of the original tile-components. The coefficients provide frequency information about a local area, rather than across the entire image like the Fourier transformation. A decomposition level is related to the next decomposition level by a spatial factor of two. That is, each successive decomposition level of the sub-bands has approximately half the horizontal and half the vertical resolution of the previous. (See Annex F.) + +Although there are as many coefficients as there are samples, the information content tends to be concentrated in just a few coefficients. Through quantization, the information content of a large number of small-magnitude coefficients is further reduced (Annex E). Additional processing by the entropy coder reduces the number of bits required to represent these quantized coefficients, sometimes significantly compared to the original image. (See Annexes C, D and B.) + +The individual sub-bands of a tile-component are further divided into code-blocks. These rectangular arrays of coefficients can be extracted independently. The individual bit-planes of the coefficients in a code-block are coded with three coding passes. Each of these coding passes collects contextual information about the bit-plane compressed image data. (See Annex D.) + +An arithmetic coder uses this contextual information, and its internal state, to encode coefficients. (See Annex C.) Different termination mechanisms allow different levels of independent extraction of this coding pass compressed image data. + +The bit stream compressed image data created from these coding passes is grouped in layers. Layers are arbitrary groupings of coding passes from code-blocks. (See Annex B.) + +NOTE – Although there is great flexibility in layering, the premise is that each successive layer contributes to a higher quality image. + +Sub-band coefficients at each resolution level are partitioned into rectangular areas called precincts. (See Annex B.) + +Packets are a fundamental unit of the compressed codestream. A packet contains compressed image data from one layer of a precinct of one resolution level of one tile-component. Packets provide another method for extracting a spatial region independently from the codestream. These packets are interleaved in the codestream using a few different methods. (See Annex B.) + +A mechanism is provided that allows the compressed image data corresponding to regions of interest in the original tile components to be coded and placed earlier in the bit stream. (See Annex H.) + +Several mechanisms are provided to allow the detection and concealment of bit errors that might occur over a noisy transmission channel. (See Annex D.) + +The codestream relating to a tile, organized in packets, are arranged in one, or more, tile-parts. A tile-part header, comprised of a series of markers and marker segments, contains information about the various mechanisms and coding styles that are needed to locate, extract, decode, and reconstruct every tile-component. At the beginning of the entire codestream is a main header, comprised of markers and marker segments, that offers similar information as well as information about the original image. (See Annex A.) + +The codestream is optionally wrapped in a file format that allows applications to interpret the meaning of, and other information about, the image. The file format may contain data besides the codestream. (See Annex I.) + +To review, procedures that divide the original image are the following: + +- The components of the image are divided into rectangular tiles. The tile-component is the basic unit of the original or reconstructed image. +- Performing the wavelet transformation on a tile-component creates decomposition levels. +- These decomposition levels are made up of sub-bands of coefficients that describe the frequency characteristics of local areas (rather than across the entire tile-component) of the tile-component. +- The sub-bands of coefficients are quantized and collected into rectangular arrays of code-blocks. +- Each bit-plane of the coefficients in a code-block is entropy coded in three types of coding passes. +- Some of the coefficients can be coded first to provide a region of interest. + +At this point the image data is fully converted to compressed image data. The procedures that reassemble these bit stream units into the codestream are the following: + +- The compressed image data from the coding passes are collected in layers. +- Packets are composed compressed image data from one precinct of a single layer of a single resolution level of a single tile-component. The packets are the basic unit of the compressed image data. +- All the packets from a tile are interleaved in one of several orders and placed in one, or more, tile-parts. +- The tile-parts have a descriptive tile-part header and can be interleaved in some orders. +- The codestream has a main header at the beginning that describes the original image and the various decomposition and coding styles. +- The optional file format describes the meaning of the image and its components in the context of the application. + +# 6 Encoder requirements + +## 6.1 General + +An encoding process converts source image data to compressed image data. Annexes A, B, C, D, E, F, G and H describe the encoding process. All encoding processes are normative. An encoder is an embodiment of the encoding process. In order to conform to this Recommendation | International Standard, an encoder shall convert source image data to compressed image data, that conform to the codestream syntax specified in Annex A. + +There is no required specific implementation for the encoder. In some cases, the descriptions use particular implementation techniques for illustrative purposes only. + +The definition of an entry-level encoder is separated into three groups: + +- encoder function; +- implementation; +- codestream description. + +## 6.2 Encoder function definition + +There are four encoding styles described in this Recommendation | International Standard: + +- lossless based colour encoding; +- lossy based colour encoding; +- lossless based greyscale encoding; +- lossy based greyscale encoding. + +The definition of image and compressed data ordering is applied commonly above four styles. Table 1 shows the definition of image and compressed data ordering. All reference of Table 1 is described in Annex B in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004. + +Table 1 – Function definition of image and compressed data ordering + +| Item | Reference | +|---------------------------------------------------------|-----------------| +| Reference grid | B.2* | +| Tiling | B.3* | +| Sub-band | B.5* | +| Precinct | B.6* | +| Code-block (64x64 or 32x32) | B.7* | +| Layer | B.8* | +| Packet | B.9* | +| Packet header coding | B.10* | +| Tile-parts (plural) | B.11* | +| Part 1 progression order (one of 5 progression methods) | B.12.1* | +| Progression order change | B.12.2, B.12.3* | +| * Described in ITU-T Rec. T.800 ISO/IEC 15444-1:2004. | | + +### 6.2.1 Lossless based colour encoding + +Lossless based colour encoding process is shown in Figure 2. Because a basic concept of lossless based colour encoding is colour image exchange lossless, reversible component transformation (RCT) and reversible wavelet transformation (5-3R) shall be executed. Also scalar quantization shall not be executed. It may be used in truncated codestream to provide lossy compression. + +Function definition of Lossless based colour encoding is shown in Table 2. + +![Figure 2 – Lossless based colour encoding block diagram. The diagram shows a sequential process: DC level shift (Annex G) → Component transformation (Annex G) containing RCT and ICT (dashed) → Transformation (Annex F) containing 5-3R and 9-7I (dashed) → Quantization (Annex E) (dashed) → Coefficient bit modelling (Annex D) → Arithmetic coding (Annex C) → Data ordering (Annex B). An ROI (Annex H) block points to the Coefficient bit modelling block.](75f0cb39f1cd165dfe4a6aa6c4d9388d_img.jpg) + +``` + +graph LR + Input(( )) --> DC[DC level shift +(Annex G)] + DC --> CT[Component transformation +(Annex G)] + subgraph CT_Box [Component transformation (Annex G)] + RCT[RCT] + ICT[ICT] + end + CT_Box --> TF[Transformation +(Annex F)] + subgraph TF_Box [Transformation (Annex F)] + 53R[5-3R] + 97I[9-7I] + end + TF_Box --> Q[Quantization +(Annex E)] + subgraph Q_Box [Quantization (Annex E)] + Q + end + Q_Box --> CBM[Coefficient bit modelling +(Annex D)] + ROI[ROI +(Annex H)] --> CBM + CBM --> AC[Arithmetic coding +(Annex C)] + AC --> DO[Data ordering +(Annex B)] + DO --> Output(( )) + +``` + +Figure 2 – Lossless based colour encoding block diagram. The diagram shows a sequential process: DC level shift (Annex G) → Component transformation (Annex G) containing RCT and ICT (dashed) → Transformation (Annex F) containing 5-3R and 9-7I (dashed) → Quantization (Annex E) (dashed) → Coefficient bit modelling (Annex D) → Arithmetic coding (Annex C) → Data ordering (Annex B). An ROI (Annex H) block points to the Coefficient bit modelling block. + +T.812(07)\_F-02 + +**Figure 2 – Lossless based colour encoding block diagram** + +**Table 2 – Function definition of lossless based colour encoding** + +| Category | Item | Reference | +|----------------------------------------------------------|-------------------------------------------------------|-----------| +| DC level shifting and multiple component transformations | DC level shifting data | G.1 | +| | RCT | G.2 | +| Discrete wavelet transform | Wavelet transform (5-3R) | F.3 | +| | Sub-sampling by discarding coefficients | F.4 | +| | Visual frequency weighting | F.5 | +| Coefficient bit modelling | 3-coding pass, 4-coding mode (EBCOT) | D.3 | +| | Predictable termination | D.4 | +| | Reset context probabilities on coding pass boundaries | D.4 | +| | Termination on each coding pass | D.4 | +| | Segmentation symbols | D.5 | +| | Selective AC bypass | D.6 | +| | Vertically causal context | D.7 | +| Arithmetic entropy coding | MQ-Coder Encoding | C.2 | +| Region of Interest | Max-shift | H.1, H.2 | + +### 6.2.2 Lossy based colour encoding + +Lossy-based colour encoding process is shown in Figure 3. Lossy-based colour encoding has several purposes such as high compression performance or fixed codestream size. Irreversible component transformation (ICT) and irreversible wavelet transformation (9-7I) shall be executed. Scalar quantization may be executed. + +Function definition of Lossy based colour encoding is shown in Table 3. + +![Figure 3 – Lossy based colour encoding block diagram. The diagram shows a sequential process: DC level shift (Annex G) -> Component transformation (Annex G) containing RCT and ICT -> Transformation (Annex F) containing 5-3R and 9-7I -> Quantization (Annex E) -> Coefficient bit modelling (Annex D) -> Arithmetic coding (Annex C) -> Data ordering (Annex B). A Region of Interest (ROI) block (Annex H) has arrows pointing to the Quantization and Coefficient bit modelling blocks.](16152cf1d84aea10848758f51a91ff6a_img.jpg) + +``` +graph LR + Input(( )) --> DC[DC level shift +(Annex G)] + DC --> Comp[Component transformation +(Annex G)] + subgraph CompBox [Component transformation (Annex G)] + RCT[RCT] + ICT[ICT] + end + Comp --> Trans[Transformation +(Annex F)] + subgraph TransBox [Transformation (Annex F)] + 53R[5-3R] + 97I[9-7I] + end + Trans --> Quant[Quantization +(Annex E)] + ROI[ROI +(Annex H)] --> Quant + ROI --> CBB[Coefficient bit modelling +(Annex D)] + Quant --> CBB + CBB --> AC[Arithmetic coding +(Annex C)] + AC --> DO[Data ordering +(Annex B)] + DO --> Output(( )) +``` + +Figure 3 – Lossy based colour encoding block diagram. The diagram shows a sequential process: DC level shift (Annex G) -> Component transformation (Annex G) containing RCT and ICT -> Transformation (Annex F) containing 5-3R and 9-7I -> Quantization (Annex E) -> Coefficient bit modelling (Annex D) -> Arithmetic coding (Annex C) -> Data ordering (Annex B). A Region of Interest (ROI) block (Annex H) has arrows pointing to the Quantization and Coefficient bit modelling blocks. + +T.812(07)\_F-03 + +Figure 3 – Lossy based colour encoding block diagram + +Table 3 – Function definition of lossy based colour encoding + +| Category | Item | Reference | +|----------------------------------------------------------|-------------------------------------------------------|-----------| +| DC level shifting and multiple component transformations | DC level shifting data | G.1 | +| | ICT | G.3 | +| Discrete wavelet transform | Wavelet transform (9-7I) | F.3 | +| | Sub-sampling by discarding coefficients | F.4 | +| | Visual frequency weighting | F.5 | +| Quantization | Scalar quantization | E.2 | +| Coefficient bit modelling | 3-coding pass, 4-coding mode (EBCOT) | D.3 | +| | Predictable termination | D.4 | +| | Reset context probabilities on coding pass boundaries | D.4 | +| | Termination on each coding pass | D.4 | +| | Segmentation symbols | D.5 | +| | Selective AC bypass | D.6 | +| | Vertically causal context | D.7 | +| Arithmetic entropy coding | MQ-Coder Encoding | C.2 | +| Region of Interest | Max-shift | H.1, H.2 | + +### 6.2.3 Lossless based greyscale encoding + +Lossless based greyscale encoding process is shown in Figure 4. A basic concept of lossless based greyscale encoding is almost the same as lossless based colour encoding, but source image is changed colour to greyscale. Reversible wavelet transformation (5-3R) shall be executed. Component transformation and scalar quantization shall not be executed. It may be used in truncated codestream to provide lossy compression. + +Function definition of lossless based greyscale encoding is shown in Table 4. + +![Figure 4 – Lossless based greyscale encoding block diagram. The diagram shows a sequence of processing blocks: DC level shift (Annex G) → Component transformation (Annex G) containing RCT and ICT → Transformation (Annex F) containing 5-3R and 9-7I → Quantization (Annex E) → Coefficient bit modelling (Annex D) → Arithmetic coding (Annex C) → Data ordering (Annex B). An ROI (Annex H) block points to the Coefficient bit modelling block. The text T.812(07)_F-04 is located at the bottom right.](df82d77a0d2637cbf2da9ea920a554fa_img.jpg) + +``` + +graph LR + Input(( )) --> DC[DC level shift +(Annex G)] + DC --> CT[Component transformation +(Annex G)] + subgraph CT_Box [Component transformation (Annex G)] + RCT[RCT] + ICT[ICT] + end + CT --> TF[Transformation +(Annex F)] + subgraph TF_Box [Transformation (Annex F)] + 53R[5-3R] + 97I[9-7I] + end + TF --> Q[Quantization +(Annex E)] + Q --> CBM[Coefficient bit modelling +(Annex D)] + ROI[ROI +(Annex H)] --> CBM + CBM --> AC[Arithmetic coding +(Annex C)] + AC --> DO[Data ordering +(Annex B)] + DO --> Output(( )) + +``` + +T.812(07)\_F-04 + +Figure 4 – Lossless based greyscale encoding block diagram. The diagram shows a sequence of processing blocks: DC level shift (Annex G) → Component transformation (Annex G) containing RCT and ICT → Transformation (Annex F) containing 5-3R and 9-7I → Quantization (Annex E) → Coefficient bit modelling (Annex D) → Arithmetic coding (Annex C) → Data ordering (Annex B). An ROI (Annex H) block points to the Coefficient bit modelling block. The text T.812(07)\_F-04 is located at the bottom right. + +**Figure 4 – Lossless based greyscale encoding block diagram** + +**Table 4 – Function definition of lossless based greyscale encoding** + +| Category | Item | Reference | +|----------------------------------------------------------|-------------------------------------------------------|-----------| +| DC level shifting and multiple component transformations | DC level shifting data | G.1 | +| Discrete wavelet transform | Wavelet transform (5-3R) | F.3 | +| | Visual frequency weighting | F.5 | +| Coefficient bit modelling | 3-coding pass, 4-coding mode (EBCOT) | D.3 | +| | Predictable termination | D.4 | +| | Reset context probabilities on coding pass boundaries | D.4 | +| | Termination on each coding pass | D.4 | +| | Segmentation symbols | D.5 | +| | Selective AC bypass | D.6 | +| | Vertically causal context | D.7 | +| Arithmetic entropy coding | MQ-Coder Encoding | C.2 | +| Region of Interest | Max-shift | H.1, H.2 | + +### 6.2.4 Lossy based greyscale encoding + +Lossy-based greyscale encoding process is shown in Figure 5. A concept of lossy-based greyscale encoding is almost the same as lossy based colour encoding, but source image is changed colour to greyscale. Irreversible wavelet transformation (9-7I) shall be executed. Scalar quantization may be executed. Component transformation shall not be executed. + +Function definition of lossy based greyscale encoding is shown in Table 5. + +![Figure 5 – Lossy based greyscale encoding block diagram. The diagram shows a sequence of processing blocks: DC level shift (Annex G) -> Component transformation (Annex G) containing RCT and ICT -> Transformation (Annex F) containing 5-3R and 9-7I -> Quantization (Annex E) -> Coefficient bit modelling (Annex D) -> Arithmetic coding (Annex C) -> Data ordering (Annex B). An ROI (Annex H) block has arrows pointing to the Quantization and Coefficient bit modelling blocks. The text 'T.812(07)_F-05' is located at the bottom right of the diagram area.](9b9d2abd741ed4bafe7f78f89961c663_img.jpg) + +T.812(07)\_F-05 + +Figure 5 – Lossy based greyscale encoding block diagram. The diagram shows a sequence of processing blocks: DC level shift (Annex G) -> Component transformation (Annex G) containing RCT and ICT -> Transformation (Annex F) containing 5-3R and 9-7I -> Quantization (Annex E) -> Coefficient bit modelling (Annex D) -> Arithmetic coding (Annex C) -> Data ordering (Annex B). An ROI (Annex H) block has arrows pointing to the Quantization and Coefficient bit modelling blocks. The text 'T.812(07)\_F-05' is located at the bottom right of the diagram area. + +Figure 5 – Lossy based greyscale encoding block diagram + +Table 5 – Function definition of lossy based greyscale encoding + +| Category | Item | Reference | +|----------------------------------------------------------|-------------------------------------------------------|-----------| +| DC level shifting and multiple component transformations | DC level shifting data | G.1 | +| Discrete wavelet transform | Wavelet transform (9-7I) | F.3 | +| | Visual frequency weighting | F.5 | +| Quantization | Scalar quantization | E.2 | +| Coefficient bit modelling | 3-coding pass, 4-coding mode (EBCOT) | D.3 | +| | Predictable termination | D.4 | +| | Reset context probabilities on coding pass boundaries | D.4 | +| | Termination on each coding pass | D.4 | +| | Segmentation symbols | D.5 | +| | Selective AC bypass | D.6 | +| | Vertically causal context | D.7 | +| Arithmetic entropy coding | MQ-Coder Encoding | C.2 | +| Region of Interest | Max-shift | H.1, H.2 | + +## 6.3 Implementation + +There is no required specific implementation for this Recommendation | International Standard. This subclause defines optional implementation choices. + +Implementation definition is shown in Table 6. All reference of Table 6 is described in Annex J in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004. + +Table 6 – Implementation definition + +| Category | Item | Reference | +|---------------------------------------------------------|-----------------------------|-----------| +| Implementation | Row-based wavelet transform | J.5* | +| | Visual frequency weighting | J.12* | +| | Rate control | J.14* | +| * Described in ITU-T Rec. T.800 ISO/IEC 15444-1:2004. | | | + +## 6.4 Codestream description + +Any compressed image data shall comply with the syntax and code assignments appropriate for the coding processes defined in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004. + +ITU-T Rec. T.803 | ISO/IEC 15444-4:2004 (JPEG 2000 Part 4) describes a definition of compliance or conformance. + +This subclause defines the use of a particular marker segment for an encoder. + +Codestream description is shown in Table 7. All reference of Table 7 is described in Annex A in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004. + +**Table 7 – Codestream description** + +| Category | Item | Reference | +|---------------------------------------------------------|--------------------|-----------| +| Implementation | SOC marker | A.4.1* | +| | SOT marker segment | A.4.2* | +| | SOD marker | A.4.3* | +| | EOC marker | A.4.4* | +| | SIZ marker segment | A.5.1* | +| | COD marker segment | A.6.1* | +| | COC marker segment | A.6.2* | +| | RGN marker segment | A.6.3* | +| | QCD marker segment | A.6.4* | +| | QCC marker segment | A.6.5* | +| | POC marker segment | A.6.6* | +| | TLM marker segment | A.7.1* | +| | PLM marker segment | A.7.2* | +| | PLT marker segment | A.7.3* | +| | PPM marker segment | A.7.4* | +| | PPT marker segment | A.7.5* | +| | SOP marker segment | A.8.1* | +| | EPH marker segment | A.8.2* | +| | CRG marker segment | A.9.1* | +| | COM marker segment | A.9.2* | +| * Described in ITU-T Rec. T.800 ISO/IEC 15444-1:2004. | | | + +# 7 Optional file format requirements + +Annex I describes the optional file format containing metadata about the image in addition to the codestream. This data allows, for example, screen display or printing at a specific resolution. The optional file format, when used, shall comply with the file format syntax and code assignments appropriate for the coding processes defined in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004. + +## **Annex A** + +## **Codestream syntax** + +(This annex forms an integral part of this Recommendation | International Standard) + +There is no additional codestream syntax of JPEG 2000 codestream. + +This annex is identical to Annex A in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004. + +## **Annex B** + +## **Image and compressed image data ordering** + +(This annex forms an integral part of this Recommendation | International Standard) + +There is no additional definition of image and compressed data ordering. + +This annex is identical to Annex B in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004. + +## Annex C + +## Arithmetic entropy coding + +(This annex forms an integral part of this Recommendation | International Standard) + +In this annex and all of its subclauses, the flow charts and tables are normative only in the sense that they are defining an output that alternative implementations shall duplicate. + +### C.1 Binary encoding + +Figure C.1 shows a simple block diagram of the binary adaptive arithmetic encoder. The decision (D) and context (CX) pairs are processed together to produce compressed image data (CD) output. Both D and CX are provided by the model unit (not shown). CX selects the probability estimate to use during the coding of D. In this Recommendation | International Standard, CX is a label for a context. + +![Block diagram of the arithmetic encoder. Two input arrows labeled 'D' and 'CX' enter a rectangular block labeled 'ENCODER' from the left. A single output arrow labeled 'CD' exits the block to the right. Below the diagram is the label 'T.812(07)_F-C1'.](90ddf538ef276510e2b631f7b96654e6_img.jpg) + +``` + +graph LR + D[D] --> ENCODER[ENCODER] + CX[CX] --> ENCODER + ENCODER --> CD[CD] + +``` + +T.812(07)\_F-C1 + +Block diagram of the arithmetic encoder. Two input arrows labeled 'D' and 'CX' enter a rectangular block labeled 'ENCODER' from the left. A single output arrow labeled 'CD' exits the block to the right. Below the diagram is the label 'T.812(07)\_F-C1'. + +Figure C.1 – Arithmetic encoder inputs and outputs + +#### C.1.1 Recursive interval subdivision + +The recursive probability interval subdivision of Elias coding is the basis for the binary arithmetic coding process. With each binary decision the current probability interval is subdivided into two sub-intervals, and the code string is modified (if necessary) so that it points to the base (the lower bound) of the probability sub-interval assigned to the symbol that occurred. + +In the partitioning of the current interval into two sub-intervals, the sub-interval for the more probable symbol (MPS) is ordered above the sub-interval for the less probable symbol (LPS). Therefore, when the MPS is coded, the LPS sub-interval is added to the code string. This coding convention requires that symbols be recognized as MPS or LPS, rather than 0 or 1. Consequently, the size of the LPS interval and the sense of the MPS for each decision must be known in order to code that decision. + +Since the code string always points to the base of the current interval, the decoding process is a matter of determining, for each decision, which sub-interval is pointed to by the compressed image data. This is also done recursively, using the same interval sub-division process as in the encoder. Each time a decision is decoded, the decoder subtracts any interval the encoder added to the code string. Therefore, the code string in the decoder is a pointer into the current interval relative to the base of the current interval. Since the coding process involves addition of binary fractions rather than concatenation of integer code words, the more probable binary decisions can often be coded at a cost of much less than one bit per decision. + +#### C.1.2 Coding conventions and approximations + +The coding operations are done using fixed precision integer arithmetic and using an integer representation of fractional values in which 0x8000 is equivalent to decimal 0.75. The interval A is kept in the range $0.75 \leq A < 1.5$ by doubling it whenever the integer value falls below 0x8000. + +The code register C is also doubled each time A is doubled. Periodically – to keep C from overflowing – a byte of compressed image data is removed from the high order bits of the C-register and placed in an external compressed image data buffer. Carry-over into the external buffer is prevented by a bit-stuffing procedure. + +Keeping A in the range $0.75 \leq A < 1.5$ allows a simple arithmetic approximation to be used in the interval subdivision. The interval is A and the current estimate of the LPS probability is Qe, a precise calculation of the sub-intervals would require: + +$$A - (Qe * A) = \text{sub-interval for the MPS} \quad (C-1)$$ + +$$Qe * A = \text{sub-interval for the LPS} \quad (C-2)$$ + +Because the value of A is of order unity, these are approximated by: + +$$A - Q_e = \text{sub-interval for the MPS} \quad (\text{C-3})$$ + +$$Q_e = \text{sub-interval for the LPS} \quad (\text{C-4})$$ + +Whenever the MPS is coded, the value of $Q_e$ is added to the code register and the interval is reduced to $A - Q_e$ . Whenever the LPS is coded, the code register is left unchanged and the interval is reduced to $Q_e$ . The precision range required for A is then restored, if necessary, by renormalization of both A and C. + +With the process illustrated above, the approximations in the interval subdivision process can sometimes make the LPS sub-interval larger than the MPS sub-interval. If, for example, the value of $Q_e$ is 0.5 and A is at the minimum allowed value of 0.75, the approximate scaling gives 1/3 of the interval to the MPS and 2/3 to the LPS. To avoid this size inversion, the MPS and LPS intervals are exchanged whenever the LPS interval is larger than the MPS interval. This MPS/LPS conditional exchange can only occur when a renormalization is needed. + +Whenever a renormalization occurs, a probability estimation process is invoked which determines a new probability estimate for the context currently being coded. No explicit symbol counts are needed for the estimation. The relative probabilities of renormalization after coding an LPS or MPS provide an approximate symbol counting mechanism which is used to directly estimate the probabilities. + +### C.2 Description of the arithmetic encoder + +The ENCODER (Figure C.2) initializes the encoder through the INITENC procedure. CX and D pairs are read and passed on to ENCODE until all pairs have been read. The probability estimation procedures that provide adaptive estimates of the probability for each context are imbedded in ENCODE. Bytes of compressed image data are output when necessary. When all of the CX and D pairs have been read, FLUSH sets the contents of the C-register to as many 1 bits as possible and then outputs the final bytes. FLUSH also terminates the encoding and generates the required terminating marker. + +![Flowchart of the Encoder for the MQ-coder. The process starts with an oval labeled 'ENCODER', followed by a rectangle 'INITENC'. Then a rectangle 'Read CX, D' leads to another rectangle 'ENCODE'. A decision diamond 'Finished?' follows. If 'No', it loops back to 'Read CX, D'. If 'Yes', it goes to a rectangle 'FLUSH', which then leads to an oval 'Done'. The label 'T.812(07)_F-C2' is at the bottom right of the flowchart.](19a59d6b53059ebd27b13c98793f88e0_img.jpg) + +``` + +graph TD + ENCODER([ENCODER]) --> INITENC[INITENC] + INITENC --> ReadCX[Read CX, D] + ReadCX --> ENCODE[ENCODE] + ENCODE --> Finished{Finished?} + Finished -- No --> ReadCX + Finished -- Yes --> FLUSH[FLUSH] + FLUSH --> Done([Done]) + +``` + +T.812(07)\_F-C2 + +Flowchart of the Encoder for the MQ-coder. The process starts with an oval labeled 'ENCODER', followed by a rectangle 'INITENC'. Then a rectangle 'Read CX, D' leads to another rectangle 'ENCODE'. A decision diamond 'Finished?' follows. If 'No', it loops back to 'Read CX, D'. If 'Yes', it goes to a rectangle 'FLUSH', which then leads to an oval 'Done'. The label 'T.812(07)\_F-C2' is at the bottom right of the flowchart. + +Figure C.2 – Encoder for the MQ-coder + +#### C.2.1 Encoder code register conventions + +The flow charts given in this annex assume the register structures for the encoder shown in Table C.1. + +Table C.1 – Encoder register structures + +| | MSB | | | LSB | +|------------|-----------|-----------|-----------|-----------| +| C-register | 0000 cbbb | bbbb bsss | xxxx xxxx | xxxx xxxx | +| A-register | 0000 0000 | 0000 0000 | 1aaa aaaa | aaaa aaaa | + +The "a" bits are the fractional bits in the A register (the current interval value) and the "x" bits are the fractional bits in the code register. The "s" bits are spacer bits which provide useful constraints on carry-over, and the "b" bits indicate the bit positions from which the completed bytes of the compressed image data are removed from the C-register. The "c" bit is a carry bit. The detailed description of bit stuffing and the handling of carry-over will be given in a later part of this annex. + +#### C.2.2 Encoding a decision (ENCODE) + +The ENCODE procedure determines whether the decision D is a 0 or not. Then a CODE0 or a CODE1 procedure is called appropriately. Often embodiments will not have an ENCODE procedure, but will call the CODE0 or CODE1 procedures directly to code a 0-decision or a 1-decision. Figure C.3 shows this procedure. + +![Flowchart of the ENCODE procedure. It starts with an oval labeled 'ENCODE', followed by a decision diamond 'D = 0?'. If 'No', it goes to a rectangle labeled 'CODE1'. If 'Yes', it goes to a rectangle labeled 'CODE0'. Both paths merge and lead to an oval labeled 'Done'.](4b87467ad9642943235f48f7d4b59449_img.jpg) + +``` + +graph TD + ENCODE([ENCODE]) --> D0{D = 0?} + D0 -- No --> CODE1[CODE1] + D0 -- Yes --> CODE0[CODE0] + CODE1 --> Done([Done]) + CODE0 --> Done + +``` + +T.812(07)\_F-C3 + +Flowchart of the ENCODE procedure. It starts with an oval labeled 'ENCODE', followed by a decision diamond 'D = 0?'. If 'No', it goes to a rectangle labeled 'CODE1'. If 'Yes', it goes to a rectangle labeled 'CODE0'. Both paths merge and lead to an oval labeled 'Done'. + +Figure C.3 – ENCODE procedure + +#### C.2.3 Encoding a 1 or a 0 (CODE1 and CODE0) + +When a given binary decision is coded, one of two possibilities occurs – the symbol is either the more probable symbol or it is the less probable symbol. CODE1 and CODE0 are illustrated in Figures C.4 and C.5. In these figures, CX is the context. For each context, the index of the probability estimate that is to be used in the coding operations and the MPS value are stored. MPS (CX) is the sense (0 or 1) of the MPS for context CX. + +![Flowchart of the CODE1 procedure. It starts with an oval labeled 'CODE1', followed by a decision diamond 'MPS (CX) = 1?'. If 'No', it goes to a rectangle labeled 'CODELPS'. If 'Yes', it goes to a rectangle labeled 'CODEMPS'. Both paths merge and lead to an oval labeled 'Done'.](19a5f0db57a21a0e82a7f326083e96fd_img.jpg) + +``` + +graph TD + CODE1([CODE1]) --> MPS1{MPS (CX) = 1?} + MPS1 -- No --> CODELPS[CODELPS] + MPS1 -- Yes --> CODEMPS[CODEMPS] + CODELPS --> Done([Done]) + CODEMPS --> Done + +``` + +T.812(07)\_F-C4 + +Flowchart of the CODE1 procedure. It starts with an oval labeled 'CODE1', followed by a decision diamond 'MPS (CX) = 1?'. If 'No', it goes to a rectangle labeled 'CODELPS'. If 'Yes', it goes to a rectangle labeled 'CODEMPS'. Both paths merge and lead to an oval labeled 'Done'. + +Figure C.4 – CODE1 procedure + +![Flowchart of the CODE0 procedure. It starts with an oval labeled 'CODE0', followed by a decision diamond 'MPS (CX) = 0?'. If 'No', it goes to a rectangle labeled 'CODELPS'. If 'Yes', it goes to a rectangle labeled 'CODEMPS'. Both paths merge and lead to an oval labeled 'Done'.](d3b5eac55166fc428a223bba5c46961b_img.jpg) + +``` + +graph TD + CODE0([CODE0]) --> MPS0{MPS (CX) = 0?} + MPS0 -- No --> CODELPS[CODELPS] + MPS0 -- Yes --> CODEMPS[CODEMPS] + CODELPS --> Done([Done]) + CODEMPS --> Done + +``` + +T.812(07)\_F-C5 + +Flowchart of the CODE0 procedure. It starts with an oval labeled 'CODE0', followed by a decision diamond 'MPS (CX) = 0?'. If 'No', it goes to a rectangle labeled 'CODELPS'. If 'Yes', it goes to a rectangle labeled 'CODEMPS'. Both paths merge and lead to an oval labeled 'Done'. + +Figure C.5 – CODE0 procedure + +#### C.2.4 Encoding an MPS or LPS (CODEMPS and CODELPS) + +The CODELPS (Figure C.6) procedure usually consists of a scaling of the interval to $Qe(I(CX))$ , the probability estimate of the LPS determined from the index $I$ stored for context $CX$ . The upper interval is first calculated so it can be compared to the lower interval to confirm that $Qe$ has the smaller size. It is always followed by a renormalization (RENORME). In the event that the interval sizes are inverted, however, the conditional MPS/LPS exchange occurs and the upper interval is coded. In either case, the probability estimate is updated. If the SWITCH flag for the index $I(CX)$ is set, then the $MPS(CX)$ is inverted. A new index $I$ is saved at $CX$ as determined from the next LPS index (NLPS) column in Table C.2. + +![Flowchart of the CODELPS procedure with conditional MPS/LPS exchange.](26d664119ad25250780f554633444e54_img.jpg) + +``` + +graph TD + Start([CODELPS]) --> A1[A = A - Qe(I(CX))] + A1 --> D1{A < Qe(I(CX))?} + D1 -- No --> A2[A = Qe(I(CX))] + D1 -- Yes --> C1[C = C + Qe(I(CX))] + A2 --> D2{SWITCH(I(CX)) = 1?} + C1 --> D2 + D2 -- Yes --> MPS[MPS(CX) = 1 - MPS(CX)] + D2 -- No --> I[I(CX) = NLPS(I(CX))] + MPS --> I + I --> RENORME[RENORME] + RENORME --> Done([Done]) + +``` + +T.812(07)\_F-C6 + +Flowchart of the CODELPS procedure with conditional MPS/LPS exchange. + +Figure C.6 – CODELPS procedure with conditional MPS/LPS exchange + +![Flowchart of the CODEMPS procedure with conditional MPS/LPS exchange.](a0739aaf13fa5a632d4faa830f6b2708_img.jpg) + +``` + +graph TD + Start([CODEMPS]) --> A1[A = A - Qe(I(CX))] + A1 --> D1{A AND 0x8000 = 0?} + D1 -- No --> C1[C = C + Qe(I(CX))] + D1 -- Yes --> D2{A < Qe(I(CX))?} + D2 -- No --> C2[C = C + Qe(I(CX))] + D2 -- Yes --> A2[A = Qe(I(CX))] + C1 --> I[I(CX) = NMPS(I(CX))] + C2 --> I + A2 --> I + I --> RENORME[RENORME] + RENORME --> Done([Done]) + +``` + +T.812(07)\_F-C7 + +Flowchart of the CODEMPS procedure with conditional MPS/LPS exchange. + +Figure C.7 – CODEMPS procedure with conditional MPS/LPS exchange + +Table C.2 – Qe values and probability estimation + +| Index | Qe_Value | | | NMPS | NLPS | SWITCH | +|-------|---------------|---------------------|-----------|------|------|--------| +| | (hexadecimal) | (binary) | (decimal) | | | | +| 0 | 0x5601 | 0101 0110 0000 0001 | 0.503937 | 1 | 1 | 1 | +| 1 | 0x3401 | 0011 0100 0000 0001 | 0.304715 | 2 | 6 | 0 | +| 2 | 0x1801 | 0001 1000 0000 0001 | 0.140650 | 3 | 9 | 0 | +| 3 | 0x0AC1 | 0000 1010 1100 0001 | 0.063012 | 4 | 12 | 0 | +| 4 | 0x0521 | 0000 0101 0010 0001 | 0.030053 | 5 | 29 | 0 | +| 5 | 0x0221 | 0000 0010 0010 0001 | 0.012474 | 38 | 33 | 0 | +| 6 | 0x5601 | 0101 0110 0000 0001 | 0.503937 | 7 | 6 | 1 | +| 7 | 0x5401 | 0101 0100 0000 0001 | 0.492218 | 8 | 14 | 0 | +| 8 | 0x4801 | 0100 1000 0000 0001 | 0.421904 | 9 | 14 | 0 | +| 9 | 0x3801 | 0011 1000 0000 0001 | 0.328153 | 10 | 14 | 0 | +| 10 | 0x3001 | 0011 0000 0000 0001 | 0.281277 | 11 | 17 | 0 | +| 11 | 0x2401 | 0010 0100 0000 0001 | 0.210964 | 12 | 18 | 0 | +| 12 | 0x1C01 | 0001 1100 0000 0001 | 0.164088 | 13 | 20 | 0 | +| 13 | 0x1601 | 0001 0110 0000 0001 | 0.128931 | 29 | 21 | 0 | +| 14 | 0x5601 | 0101 0110 0000 0001 | 0.503937 | 15 | 14 | 1 | +| 15 | 0x5401 | 0101 0100 0000 0001 | 0.492218 | 16 | 14 | 0 | +| 16 | 0x5101 | 0101 0001 0000 0001 | 0.474640 | 17 | 15 | 0 | +| 17 | 0x4801 | 0100 1000 0000 0001 | 0.421904 | 18 | 16 | 0 | +| 18 | 0x3801 | 0011 1000 0000 0001 | 0.328153 | 19 | 17 | 0 | +| 19 | 0x3401 | 0011 0100 0000 0001 | 0.304715 | 20 | 18 | 0 | +| 20 | 0x3001 | 0011 0000 0000 0001 | 0.281277 | 21 | 19 | 0 | +| 21 | 0x2801 | 0010 1000 0000 0001 | 0.234401 | 22 | 19 | 0 | +| 22 | 0x2401 | 0010 0100 0000 0001 | 0.210964 | 23 | 20 | 0 | +| 23 | 0x2201 | 0010 0010 0000 0001 | 0.199245 | 24 | 21 | 0 | +| 24 | 0x1C01 | 0001 1100 0000 0001 | 0.164088 | 25 | 22 | 0 | +| 25 | 0x1801 | 0001 1000 0000 0001 | 0.140650 | 26 | 23 | 0 | +| 26 | 0x1601 | 0001 0110 0000 0001 | 0.128931 | 27 | 24 | 0 | +| 27 | 0x1401 | 0001 0100 0000 0001 | 0.117212 | 28 | 25 | 0 | +| 28 | 0x1201 | 0001 0010 0000 0001 | 0.105493 | 29 | 26 | 0 | +| 29 | 0x1101 | 0001 0001 0000 0001 | 0.099634 | 30 | 27 | 0 | +| 30 | 0x0AC1 | 0000 1010 1100 0001 | 0.063012 | 31 | 28 | 0 | +| 31 | 0x09C1 | 0000 1001 1100 0001 | 0.057153 | 32 | 29 | 0 | +| 32 | 0x08A1 | 0000 1000 1010 0001 | 0.050561 | 33 | 30 | 0 | +| 33 | 0x0521 | 0000 0101 0010 0001 | 0.030053 | 34 | 31 | 0 | +| 34 | 0x0441 | 0000 0100 0100 0001 | 0.024926 | 35 | 32 | 0 | +| 35 | 0x02A1 | 0000 0010 1010 0001 | 0.015404 | 36 | 33 | 0 | +| 36 | 0x0221 | 0000 0010 0010 0001 | 0.012474 | 37 | 34 | 0 | +| 37 | 0x0141 | 0000 0001 0100 0001 | 0.007347 | 38 | 35 | 0 | +| 38 | 0x0111 | 0000 0001 0001 0001 | 0.006249 | 39 | 36 | 0 | +| 39 | 0x0085 | 0000 0000 1000 0101 | 0.003044 | 40 | 37 | 0 | +| 40 | 0x0049 | 0000 0000 0100 1001 | 0.001671 | 41 | 38 | 0 | +| 41 | 0x0025 | 0000 0000 0010 0101 | 0.000847 | 42 | 39 | 0 | +| 42 | 0x0015 | 0000 0000 0001 0101 | 0.000481 | 43 | 40 | 0 | +| 43 | 0x0009 | 0000 0000 0000 1001 | 0.000206 | 44 | 41 | 0 | +| 44 | 0x0005 | 0000 0000 0000 0101 | 0.000114 | 45 | 42 | 0 | + +Table C.2 – Qe values and probability estimation + +| Index | Qe_Value | | | NMPS | NLPS | SWITCH | +|-------|---------------|---------------------|-----------|------|------|--------| +| | (hexadecimal) | (binary) | (decimal) | | | | +| 45 | 0x0001 | 0000 0000 0000 0001 | 0.000023 | 45 | 43 | 0 | +| 46 | 0x5601 | 0101 0110 0000 0001 | 0.503937 | 46 | 46 | 0 | + +#### C.2.5 Probability estimation + +Table C.2 shows the Qe value associated with each Qe index. The Qe values are expressed as hexadecimal integers, as binary integers, and as decimal fractions. To convert the 15-bit integer representation of Qe to the decimal probability, the Qe values are divided by $(4/3) * (0x8000)$ . + +The estimator can be defined as a finite-state machine – a table of Qe indexes and associated next states for each type of renormalization (i.e., new table positions) – as shown in Table C.2. The change in state occurs only when the arithmetic coder interval register is renormalized. This is always done after coding the LPS, and whenever the interval register is less than 0x8000 (0.75 in decimal notation) after coding the MPS. + +After an LPS renormalization, NLPS gives the new index for the LPS probability estimate. If the switch is 1, the MPS symbol sense is reversed. + +The index to the current estimate is part of the information stored for context CX. This index is used as the index to the table of values in NMPS, which gives the next index for an MPS renormalization. This index is saved in the context storage at CX. MPS(CX) does not change. + +The procedure for estimating the probability on the LPS renormalization path is similar to that of an MPS renormalization, except that when SWITCH(I(CX)) is 1, the sense of MPS(CX) is inverted. + +The final index state 46 can be used to establish a fixed 0.5 probability estimate. + +#### C.2.6 Renormalization in the encoder (RENORME) + +Renormalization is very similar in both encoder and decoder, except that in the encoder it generates compressed bits and in the decoder it consumes compressed bits. + +The RENORME procedure for the encoder renormalization is illustrated in Figure C.8. Both the interval register A and the code register C are shifted, one bit at a time. The number of shifts is counted in the counter CT, and when CT is counted down to zero, a byte of compressed image data is removed from C by the procedure BYTEOUT. Renormalization continues until A is no longer less than 0x8000. + +![Flowchart of the RENORME procedure for encoder renormalization.](803776dff64331076ffc951fc95358ee_img.jpg) + +``` + +graph TD + RENORME([RENORME]) --> Shift[A = A << 1 +C = C << 1 +CT = CT - 1] + Shift --> CTZero{CT = 0?} + CTZero -- No --> AZero{A AND 0x8000 = 0?} + CTZero -- Yes --> BYTEOUT[BYTEOUT] + AZero -- Yes --> CTZero + AZero -- No --> Done([Done]) + +``` + +The flowchart illustrates the RENORME procedure. It begins with a process box labeled 'RENORME'. An arrow leads to a process box containing three lines of code: 'A = A << 1', 'C = C << 1', and 'CT = CT - 1'. From there, the flow enters a decision diamond labeled 'CT = 0?'. If the answer is 'No', the flow proceeds to a decision diamond labeled 'A AND 0x8000 = 0?'. If the answer to this second diamond is 'Yes', the flow loops back to the 'CT = 0?' diamond. If the answer is 'No', the flow proceeds to an oval labeled 'Done'. If the answer to the 'CT = 0?' diamond is 'Yes', the flow proceeds to a process box labeled 'BYTEOUT'. From 'BYTEOUT', the flow proceeds to the 'A AND 0x8000 = 0?' diamond. If the answer is 'Yes', the flow loops back to the 'CT = 0?' diamond. If the answer is 'No', the flow proceeds to the 'Done' oval. + +Flowchart of the RENORME procedure for encoder renormalization. + +T.812(07)\_F-C8 + +Figure C.8 – Encoder renormalization procedure + +#### C.2.7 Compressed image data output (BYTEOUT) + +The BYTEOUT routine called from RENORME is illustrated in Figure C.9. This routine contains the bit-stuffing procedures which are needed to limit carry propagation into the completed bytes of compressed image data. The conventions used make it impossible for a carry to propagate through more than the byte most recently written to the compressed image data buffer. + +![Flowchart of the BYTEOUT procedure for encoder. The process starts with a 'BYTEOUT' oval, leading to a decision 'B = 0xFF?'. If 'Yes', it goes to a block with 'BP = BP + 1', 'B = C >> 20', 'C = C AND 0xFFFF', and 'CT = 7'. If 'No', it goes to a decision 'C < 0x8000000?'. If 'Yes', it goes to the same block as the 'B = 0xFF?' 'Yes' path. If 'No', it goes to a block 'B = B + 1', then a decision 'B = 0xFF?'. If 'Yes', it goes to a block 'C = C AND 0x7FFFFFFF?', then to the same block as the 'B = 0xFF?' 'Yes' path. If 'No', it goes to a block with 'BP = BP + 1', 'B = C >> 19', 'C = C AND 0x7FFF', and 'CT = 8'. Both paths lead to a 'Done' oval.](9c1d3678db4a12d5864cb2a4def1135d_img.jpg) + +``` + +graph TD + Start([BYTEOUT]) --> B_FF{B = 0xFF?} + B_FF -- Yes --> B_FF_Yes[BP = BP + 1 +B = C >> 20 +C = C AND 0xFFFF +CT = 7] + B_FF -- No --> C_8000000{C < 0x8000000?} + C_8000000 -- Yes --> B_FF_Yes + C_8000000 -- No --> B_B_plus_1[B = B + 1] + B_B_plus_1 --> B_FF_2{B = 0xFF?} + B_FF_2 -- Yes --> C_7FFFFFFF[C = C AND 0x7FFFFFFF?] + C_7FFFFFFF --> B_FF_Yes + B_FF_2 -- No --> B_FF_2_No[BP = BP + 1 +B = C >> 19 +C = C AND 0x7FFF +CT = 8] + B_FF_Yes --> Done([Done]) + B_FF_2_No --> Done + +``` + +T.812(07)\_F-C9 + +Flowchart of the BYTEOUT procedure for encoder. The process starts with a 'BYTEOUT' oval, leading to a decision 'B = 0xFF?'. If 'Yes', it goes to a block with 'BP = BP + 1', 'B = C >> 20', 'C = C AND 0xFFFF', and 'CT = 7'. If 'No', it goes to a decision 'C < 0x8000000?'. If 'Yes', it goes to the same block as the 'B = 0xFF?' 'Yes' path. If 'No', it goes to a block 'B = B + 1', then a decision 'B = 0xFF?'. If 'Yes', it goes to a block 'C = C AND 0x7FFFFFFF?', then to the same block as the 'B = 0xFF?' 'Yes' path. If 'No', it goes to a block with 'BP = BP + 1', 'B = C >> 19', 'C = C AND 0x7FFF', and 'CT = 8'. Both paths lead to a 'Done' oval. + +Figure C.9 – BYTEOUT procedure for encoder + +The procedure in the block in the lower right section does bit stuffing after a 0xFF byte; the similar procedure on the left is for the case where bit stuffing is not needed. + +B is the byte pointed to by the compressed image data buffer pointer BP. If B is not a 0xFF byte, the carry bit is checked. If the carry bit is set, it is added to B and B is again checked to see if a bit needs to be stuffed in the next byte. After the need for bit stuffing has been determined, the appropriate path is chosen, BP is incremented and the new value of B is removed from the code register "b" bits. + +#### C.2.8 Initialization of the encoder (INITENC) + +The INITENC procedure is used to start the arithmetic coder. After MPS and I are initialized, the basic steps are shown in Figure C.10. + +![Flowchart of the INITENC procedure. It starts with an oval labeled 'INITENC', followed by a rectangle containing 'A = 0x8000', 'C = 0', 'BP = BPST - 1', and 'CT = 12'. Then a decision diamond asks 'B = 0xFF?'. If 'Yes', it goes to a rectangle 'CT = 13' and then to an oval 'Done'. If 'No', it bypasses the 'CT = 13' step and goes directly to 'Done'.](28d75f39a24203712ee907b32cf0bbe5_img.jpg) + +``` + +graph TD + Start([INITENC]) --> Init[A = 0x8000 +C = 0 +BP = BPST - 1 +CT = 12] + Init --> Decision{B = 0xFF?} + Decision -- Yes --> SetCT[CT = 13] + Decision -- No --> Done([Done]) + SetCT --> Done + +``` + +T.812(07)\_F-C10 + +Flowchart of the INITENC procedure. It starts with an oval labeled 'INITENC', followed by a rectangle containing 'A = 0x8000', 'C = 0', 'BP = BPST - 1', and 'CT = 12'. Then a decision diamond asks 'B = 0xFF?'. If 'Yes', it goes to a rectangle 'CT = 13' and then to an oval 'Done'. If 'No', it bypasses the 'CT = 13' step and goes directly to 'Done'. + +Figure C.10 – Initialization of the encoder + +The interval register and code register are set to their initial values, and the bit counter is set. Setting $CT = 12$ reflects the fact that there are three spacer bits in the register which need to be filled before the field from which the bytes are removed is reached. BP always points to the byte preceding the position BPST where the first byte is placed. Therefore, if the preceding byte is a 0xFF byte, a spurious bit stuff will occur, but can be compensated for by increasing CT. The initial settings for MPS and I are shown in Table D.7. + +#### C.2.9 Termination of coding (FLUSH) + +The FLUSH procedure shown in Figure C.11 is used to terminate the encoding operations and generate the required terminating marker. The procedure guarantees that the 0xFF prefix to the marker code overlaps the final bits of the compressed image data. This guarantees that any marker code at the end of the compressed image data will be recognized and interpreted before decoding is complete. + +![Flowchart of the FLUSH procedure (Figure C.11).](5414f65867392f05ba0063b208eeb5e1_img.jpg) + +``` + +graph TD + FLUSH([FLUSH]) --> SETBITS1[[SETBITS]] + SETBITS1 --> Cshift1[C = C << CT] + Cshift1 --> BYTEOUT1[[BYTEOUT]] + BYTEOUT1 --> Cshift2[C = C << CT] + Cshift2 --> BYTEOUT2[[BYTEOUT]] + BYTEOUT2 --> Bcheck{B = 0xFF?} + Bcheck -- Yes --> DiscardB[Discard B] + Bcheck -- No --> BPinc[BP = BP + 1] + DiscardB --> Done([Done]) + BPinc --> Done + +``` + +The flowchart illustrates the FLUSH procedure. It begins with a 'FLUSH' terminal, followed by a 'SETBITS' process, then a shift operation $C = C \ll CT$ , and a 'BYTEOUT' process. This sequence is repeated: another shift $C = C \ll CT$ followed by another 'BYTEOUT'. A decision diamond checks if $B = 0xFF$ . If 'Yes', the byte is discarded. If 'No', the buffer pointer is incremented ( $BP = BP + 1$ ). Both paths lead to the 'Done' terminal. + +T.812(07)\_F-C11 + +Flowchart of the FLUSH procedure (Figure C.11). + +**Figure C.11 – FLUSH procedure** + +The first part of the FLUSH procedure sets as many bits as possible in the C-register to 1 as shown in Figure C.12. The exclusive upper bound for the C-register is the sum of the C-register and the interval register. The low order 16 bits of C are forced to 1, and the result is compared to the upper bound. If C is too big, the leading 1 bit is removed, reducing C to a value which is within the interval. + +![Flowchart of setting the final bits in the C register (Figure C.12).](744acfe8d4e31bcf03f95714c2f6e567_img.jpg) + +``` + +graph TD + SETBITS([SETBITS]) --> TEMP[TEMPC = C + A +C = C OR 0xFFFF] + TEMP --> Ccheck{C ≥ TEMPC?} + Ccheck -- No --> Done([Done]) + Ccheck -- Yes --> Csub[C = C - 0x8000] + Csub --> Done + +``` + +The flowchart shows the process of setting the final bits in the C register. It starts with 'SETBITS', followed by the calculation $TEMPC = C + A$ and $C = C \text{ OR } 0xFFFF$ . A decision diamond checks if $C \ge TEMPC$ . If 'No', it proceeds to 'Done'. If 'Yes', it subtracts $0x8000$ from C ( $C = C - 0x8000$ ) and then proceeds to 'Done'. + +T.812(07)\_F-C12 + +Flowchart of setting the final bits in the C register (Figure C.12). + +**Figure C.12 – Setting the final bits in the C register** + +The byte in the C-register is then completed by shifting C, and two bytes are then removed. If the byte in buffer, B, is a 0xFF then it is discarded. Otherwise, buffer B is output to the bit stream. + +NOTE – This is the only normative option for termination in ITU-T Rec. T.88 | ISO/IEC 14492. However, further reduction of the bit stream is allowed in this Recommendation | International Standard provided correct decoding is assured (see D.4.2). + +## Annex D + +## Coefficient bit modelling + +(This annex forms an integral part of this Recommendation | International Standard) + +In this annex, the flow charts and tables are normative only in the sense that they are defining an output that alternative implementations shall duplicate. + +This annex defines the modelling and scanning of transform coefficient bits. + +Code-blocks (see Annex B in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004) are encoded a bit-plane at a time starting from the most significant bit-plane with a non-zero element to the least significant bit-plane. For each bit-plane in a code-block, a special code-block scan pattern is used for each of three coding passes. Each coefficient bit in the bit-plane appears in only one of the three coding passes called significance propagation, magnitude refinement, and cleanup. For each pass contexts are created which are provided to the arithmetic coder, CX, along with the decision, D (see Annex C). + +### D.1 Code-block scan pattern within code-blocks + +Each bit-plane of a code-block is scanned in a particular order. Starting at the top left, the first four coefficients of the first column are scanned, followed by the first four coefficients of the second column and so on, until the right side of the code-block is reached. The scan then returns to the left of the code-block and the second set of four coefficients in each column is scanned. The process is continued to the bottom of the code-block. If the code-block height is not divisible by 4, the last set of coefficients scanned in each column will contain fewer than 4 members. Figure D.1 shows an example of the code-block scan pattern for a code-block. + +![Figure D.1: Example scan pattern of a code-block bit-plane. The diagram shows a grid representing a code-block that is 16 wide by N high. The grid has 16 columns and 6 rows. The first four rows are numbered 0 to 63 following a vertical scan of 4 cells per column. The fifth row starts with 64 and dots. The sixth row contains dots.](f556082df0c46b714ad32cafd26dacd7_img.jpg) + +| Code-block 16 wide by N high | | | | | | | | | | | | | | | | +|------------------------------|-----|----|----|----|----|----|----|----|----|----|----|----|----|----|----| +| 0 | 4 | 8 | 12 | 16 | 20 | 24 | 28 | 32 | 36 | 40 | 44 | 48 | 52 | 56 | 60 | +| 1 | 5 | 9 | 13 | 17 | 21 | 25 | 29 | 33 | 37 | 41 | 45 | 49 | 53 | 57 | 61 | +| 2 | 6 | 10 | 14 | 18 | 22 | 26 | 30 | 34 | 38 | 42 | 46 | 50 | 54 | 58 | 62 | +| 3 | 7 | 11 | 15 | 19 | 23 | 27 | 31 | 35 | 39 | 43 | 47 | 51 | 55 | 59 | 63 | +| 64 | ... | | | | | | | | | | | | | | | +| ... | | | | | | | | | | | | | | | | + +T.812(07)\_F-D1 + +Figure D.1: Example scan pattern of a code-block bit-plane. The diagram shows a grid representing a code-block that is 16 wide by N high. The grid has 16 columns and 6 rows. The first four rows are numbered 0 to 63 following a vertical scan of 4 cells per column. The fifth row starts with 64 and dots. The sixth row contains dots. + +Figure D.1 – Example scan pattern of a code-block bit-plane + +### D.2 Coefficient bits and significance + +#### D.2.1 General case notations + +The encoding procedures specified in this annex produce for each transform coefficient $(u, v)$ of sub-band $b$ the decoded bits to be encoded which will be used to reconstruct the transform coefficient value $q_b(u, v)$ at the decoder. The bits produced are: a sign bit $s_b(u, v)$ and a number $N_b(u, v)$ of magnitude MSBs to be encoded, ordered from most to least significant: $MSB_i(b, u, v)$ is the $i$ th MSB of transform coefficient $(u, v)$ of sub-band $b$ ( $i = 1, ext{...}, N_b(u, v)$ ). As indicated in Equation (D-1), the sign bit $s_b(u, v)$ has a value of one for negative coefficients and of zero for positive coefficients. The number $N_b(u, v)$ of MSBs to be encoded includes the number of all zero most significant bit-planes signalled in the packet header (see B.10.5 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004). + +#### D.2.2 Notation in the case with ROI + +In the use of the RGN marker segment (indicating the presence of an ROI), modifications need to be made to the bits to be encoded, as well as the number $N_b(u, v)$ of magnitude MSBs to be encoded. These modifications are specified in clause H.1. In the absence of the RGN marker segment, no modification is required. + +### D.3 Encoding passes over the bit-planes + +Each coefficient in a code-block has an associated binary state variable called its significance state. Significance states are initialized to 0 (coefficient is insignificant) and may become 1 (coefficient is significant) during the course of the encoding of the code-block. The "significance state" changes from insignificant to significant (see the subclause below) at the bit-plane where the most significant magnitude bit equal to 1 is found. The context vector for a given current coefficient is the binary vector consisting of the significance states of its 8 nearest-neighbour coefficients, as shown in Figure D.2. Any nearest neighbour lying outside the current coefficient's code-block is regarded as insignificant (i.e., it is treated as having a zero significance state) for the purpose creating a context vector for encoding the current coefficient. + +![](e05b36c0d46549e681ce6581422c66b2_img.jpg) + +| | | | +|----------------|----------------|----------------| +| D 0 | V 0 | D 1 | +| H 0 | X | H 1 | +| D 2 | V 1 | D 3 | + +T.812(07)\_F-D2 + +Figure D.2 – Neighbour states used to form the context + +In general, a current coefficient can have 256 possible context vectors. These are clustered into a smaller number of contexts according to the rules specified below for context formation. Four different context formation rules are defined, one for each of the four coding passes: significance coding, sign coding, magnitude refinement coding, and cleanup coding. These coding operations are performed in three coding passes over each bit-plane: significance and sign coding in a significance propagation pass, magnitude refinement coding in a magnitude refinement pass, and cleanup and sign coding in a cleanup pass. For a given coding operation, the context label (or context) provided to the arithmetic coding engine is a label assigned to the current coefficient's context. + +NOTE – Although (for the sake of concreteness) specific integers are used in the tables below for labelling contexts, the tokens used for context labels are implementation-dependent and their values are not mandated by this Recommendation | International Standard. + +The first bit-plane within the current block with a non-zero element has a cleanup pass only. The remaining bit-planes are encoded in three coding passes. Each coefficient bit is encoded in exactly one of the three coding passes. Which pass a coefficient bit is encoded in depends on the conditions for that pass. In general, the significance propagation pass includes the coefficients that are predicted, or "most likely", to become significant and their sign bits, as appropriate. The magnitude refinement pass includes bits from already significant coefficients. The cleanup pass includes all the remaining coefficients. + +#### D.3.1 Significance propagation encoding pass + +The eight surrounding neighbour coefficients of a current coefficient (shown in Figure D.2 where X denotes the current coefficient) are used to create a context vector that maps into one of the 9 contexts shown in Table D.1. If a coefficient is significant then it is given a 1 value for the creation of the context, otherwise it is given a 0 value. The mapping to the contexts also depends on the sub-band. + +Table D.1 – Contexts for the significance propagation and cleanup coding passes + +| LL and LH sub-bands
(vertical high-pass) | | | HL sub-band
(horizontal high-pass) | | | HH sub-band
(diagonally high-pass) | | Context
label a) | +|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|------------|---------------------------------------|------------|------------|---------------------------------------|------------|--------------------------------| +| $\sum H_i$ | $\sum V_i$ | $\sum D_i$ | $\sum H_i$ | $\sum V_i$ | $\sum D_i$ | $\sum (H_i + V_i)$ | $\sum D_i$ | | +| 2 | x b) | x | x | 2 | x | x | $\geq 3$ | 8 | +| 1 | $\geq 1$ | x | $\geq 1$ | 1 | x | $\geq 1$ | 2 | 7 | +| 1 | 0 | $\geq 1$ | 0 | 1 | $\geq 1$ | 0 | 2 | 6 | +| 1 | 0 | 0 | 0 | 1 | 0 | $\geq 2$ | 1 | 5 | +| 0 | 2 | x | 2 | 0 | x | 1 | 1 | 4 | +| 0 | 1 | x | 1 | 0 | x | 0 | 1 | 3 | +| 0 | 0 | $\geq 2$ | 0 | 0 | $\geq 2$ | $\geq 2$ | 0 | 2 | +| 0 | 0 | 1 | 0 | 0 | 1 | 1 | 0 | 1 | +| 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | +| a) Note that the context labels are indexed only for identification convenience in this Recommendation International Standard.
The actual identifiers used is a matter of implementation. | | | | | | | | | +| b) "x" indicates a "don't care" state. | | | | | | | | | + +The significance propagation pass only includes bits of coefficients that were insignificant (the significance state has yet to be set) and have a non-zero context. All other coefficients are skipped. The context is delivered to the arithmetic encoder (along with the coefficient bit to be encoded). If the value of this bit is 1, then the significance state is set to 1 and the immediate next bit to be encoded is the sign bit for the coefficient. Otherwise, the significance state remains 0. When the contexts of successive coefficients and coding passes are considered, the most current significance state for this coefficient is used. + +#### D.3.2 Sign bit encoding + +The context label for sign bit encoding is determined using another context vector from the neighbourhood. Computation of the context label can be viewed as a two-step process. The first step summarizes the contribution of the vertical and the horizontal neighbours. The second step reduces those contributions to one of 5 context labels. + +For the first step, the two vertical neighbours (see Figure D.2) are considered together. Each neighbour may have one of three states: significant positive, significant negative, or insignificant. If the two vertical neighbours are both significant with the same sign, or if only one is significant, then the vertical contribution is 1 if the sign is positive or –1 if the sign is negative. If both vertical neighbours are insignificant, or both are significant with different signs, then the vertical contribution is 0. The horizontal contribution is created in the same way. Once again, if the neighbours fall outside the code-block they are considered to be insignificant. Table D.2 shows these contributions. + +Table D.2 – Contributions of the vertical (and the horizontal) neighbours to the sign context + +| V0 (or H0) | V1 (or H1) | V (or H) contribution | +|-----------------------|-----------------------|-----------------------| +| significant, positive | significant, positive | 1 | +| significant, negative | significant, positive | 0 | +| insignificant | significant, positive | 1 | +| significant, positive | significant, negative | 0 | +| significant, negative | significant, negative | –1 | +| insignificant | significant, negative | –1 | +| significant, positive | insignificant | 1 | +| significant, negative | insignificant | –1 | +| insignificant | insignificant | 0 | + +The second step reduces the nine permutations of the vertical and horizontal contributions into 5 context labels. Table D.3 shows these context labels. This context is provided to the arithmetic encoder with the decision. The sign bit is then logically exclusive ORed with the XORbit in Table D.3 to produce the decision, D (see Annex C). The following equation is used: + +$$D = \text{signbit} \otimes \text{XORbit} \quad (\text{D-1})$$ + +where *signbit* is the sign bit of the current coefficient (a one bit indicates a negative coefficient, a zero bit a positive coefficient), *D* is the value provided to the arithmetic encoder with the context label, and the *XORbit* is found in Table D.3 for the current context label. + +Table D.3 – Sign contexts from the vertical and horizontal contributions + +| Horizontal contribution | Vertical contribution | Context label | XORbit | +|-------------------------|-----------------------|---------------|--------| +| 1 | 1 | 13 | 0 | +| 1 | 0 | 12 | 0 | +| 1 | –1 | 11 | 0 | +| 0 | 1 | 10 | 0 | +| 0 | 0 | 9 | 0 | +| 0 | –1 | 10 | 1 | +| –1 | 1 | 11 | 1 | +| –1 | 0 | 12 | 1 | +| –1 | –1 | 13 | 1 | + +#### D.3.3 Magnitude refinement pass + +The magnitude refinement pass includes the bits from coefficients that are already significant (except those that have just become significant in the immediately preceding significance propagation pass). + +The context used is determined by the summation of the significance state of the horizontal, vertical and diagonal neighbours. These are the states as currently known to the encoder, not the states used before the significance encoding pass. Further, it is dependent on whether this is the first refinement bit (the bit immediately after the significance and sign bits) or not. Table D.4 shows the three contexts for this pass. + +Table D.4 – Contexts for the magnitude refinement coding passes + +| $\sum H_i + \sum V_i + \sum D_i$ | First refinement for this coefficient | Context label | +|----------------------------------------|---------------------------------------|---------------| +| $x^a)$ | false | 16 | +| $\geq 1$ | true | 15 | +| 0 | true | 14 | +| a) "x" indicates a "don't care" state. | | | + +The context is passed to the arithmetic coder along with the bit stream. The bit returned is the value of the current coefficient in the current bit-plane. + +#### D.3.4 Cleanup pass + +The remaining coefficients were previously insignificant and not handled by the significance propagation pass. The cleanup pass not only uses the neighbour context, like that of the significance propagation pass, from Table D.1, but also a run-length context. + +During this pass, the neighbour contexts for the coefficients in this pass are recreated using Table D.1. The context label can now have any value because the coefficients that were found to be significant in the significance propagation pass are considered to be significant in the cleanup pass. Run-lengths are encoded with a unique single context. If the four contiguous coefficients in the column being scanned are all encoded in the cleanup pass and the context label for all is 0 (including context coefficients from previous magnitude, significance and cleanup passes), then the unique run-length context is given to the arithmetic encoder along with the decision, D (see Annex C). If all four contiguous coefficients in the column remain insignificant, then the decision is 0. + +Otherwise, if at least one of the four contiguous coefficients in the column is significant, then the decision is 1. In this case, the next two bits, encoded with the UNIFORM context (index 46 in Table C.2), denote which coefficient from the top of the column down is the first to be found significant. The two bits encoded with the UNIFORM context are encoded MSB then LSB. That coefficient's sign bit is determined as described in D.3.2. The encoding of any remaining coefficients continues in the manner described in D.3.1. + +If the four contiguous coefficients in a column are not all to be encoded in the cleanup pass or the context bin for any is non-zero, then the coefficient bits are encoded with the context in Table D.1 as in the significance propagation pass. The same contexts as the significance propagation are used here (the state is used as well as the model). Table D.5 shows the logic for the cleanup pass. + +**Table D.5 – Run-length encoder for cleanup passes** + +| Four contiguous coefficients in a column remaining to be encoded and each currently has the 0 context | Symbols with run-length context | Four contiguous bits to be decoded are zero | Symbols decoded with UNIFORM a) context | Number of coefficients to decode | +|-------------------------------------------------------------------------------------------------------|---------------------------------|---------------------------------------------|----------------------------------------------------|----------------------------------| +| true | 0 | true | none | none | +| true | 1 | false | MSB LSB | | +| | | skip to first coefficient sign | 00 | 3 | +| | | skip to second coefficient sign | 01 | 2 | +| | | skip to third coefficient sign | 10 | 1 | +| | | skip to fourth coefficient sign | 11 | 0 | +| false | none | x | none | rest of column | +| a) See Annex C. | | | | | + +If there are fewer than four rows remaining in a code-block, then no run-length coding is used. Once again, the significance state of any coefficient is changed immediately after encoding the first 1 magnitude bit. + +#### D.3.5 Example of coding passes and significance propagation + +Table D.6 shows an example of the encoding order for the quantized coefficients of one 4-coefficient column in the scan. This example assumes all neighbours not included in the table are identically zero, and indicates in which pass each bit is encoded. The sign bit is encoded after the initial 1 bit and is indicated in the table by the + or – sign. The very first pass in a new block is always a cleanup pass because there can be no predicted significant, or refinement bits. After the first pass, the encoded 1 bit of the first coefficient causes the second coefficient to be encoded in the significance pass for the next bit-plane. The 1 bit encoded for the last coefficient in the second cleanup pass causes the third coefficient to be encoded in the next significance pass. + +**Table D.6 – Example of sub-bit-plane coding order and significance propagation** + +| Coding passes | 10 | 1 | 3 | –7 | Coefficient value | +|---------------|----|----|----|----|---------------------------------------| +| | + | + | + | – | Coefficient sign | +| | 1 | 0 | 0 | 0 | Coefficient magnitude
(MSB to LSB) | +| | 0 | 0 | 0 | 1 | | +| | 1 | 0 | 1 | 1 | | +| | 0 | 1 | 1 | 1 | | +| Cleanup | 1+ | 0 | 0 | 0 | | +| Significance | | 0 | | | | +| Refinement | 0 | | | | | +| Cleanup | | | 0 | 1– | | +| Significance | | 0 | 1+ | | | +| Refinement | 1 | | | 1 | | +| Cleanup | | | | | | +| Significance | | 1+ | | | | +| Refinement | 0 | | 1 | 1 | | +| Cleanup | | | | | | + +### D.4 Initializing and terminating + +When the contexts are initialized, or re-initialized, they are set to the values in Table D.7. + +Table D.7 – Initial states for all contexts + +| Context | Initial index from Table C.1 | MPS | +|----------------------------------------------------|------------------------------|-----| +| UNIFORM | 46 | 0 | +| Run-length | 3 | 0 | +| All zero neighbours (context label 0 in Table D.1) | 4 | 0 | +| All other contexts | 0 | 0 | + +In normal operation (not selective arithmetic coding bypass), the arithmetic coder shall be terminated either at the end of every coding pass or only at the end of every code-block (see D.4.1). Table D.8 shows two examples of termination patterns for the coding passes in a code-block. The COD or COC marker signals which termination pattern is used (see A.6.1 and A.6.2 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004). + +Table D.8 – Arithmetic coder termination patterns + +| # | Pass | Coding operation termination only on last pass | Coding operation termination on every pass | +|-------|--------------------------|------------------------------------------------|--------------------------------------------| +| 1 | cleanup | Arithmetic Coder (AC) | AC, terminate | +| 2 | significance propagation | AC | AC, terminate | +| 2 | magnitude refinement | AC | AC, terminate | +| 2 | cleanup | AC | AC, terminate | +| ... | ... | ... | ... | +| final | significance propagation | AC | AC, terminate | +| final | magnitude refinement | AC | AC, terminate | +| final | cleanup | AC, terminate | AC, terminate | + +When multiple terminations of the arithmetic coder are present, the length of each terminated segment is signalled in the packet header as described in B.10.7 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004. + +NOTE – Termination should never create a byte aligned value between 0xFF90 and 0xFFFF inclusive. These values are available as in-bit-stream marker values. + +#### D.4.1 Expected codestream termination + +The decoder anticipates that the given number of codestream bytes will decode a given number of coding passes before the arithmetic coder is terminated. During decoding, bytes are pulled successively from the codestream until all the bytes for those coding passes have been consumed. The number of bytes corresponding to the coding passes is specified in the packet header. Often at that point there are more symbols to be decoded. Therefore, the decoder shall extend the input bit stream to the arithmetic coder with 0xFF bytes, as necessary, until all symbols have been decoded. + +It is sufficient to append no more than two 0xFF bytes. This will cause the arithmetic coder to have at least one pair of consecutive 0xFF bytes at its input which is interpreted as an end-of-stream marker (see C.3.4 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004). The bit stream does not actually contain a terminating marker. However, the byte length is explicitly signalled enabling the terminating marker to be synthesized for the arithmetic decoder. + +NOTE – Two 0xFF bytes appended in this way is the simplest method. However, other equivalent extensions exist. This might be important since some arithmetic coder implementations might attach special meaning to the specific termination marker. + +#### D.4.2 Arithmetic coder termination + +The FLUSH procedure performs this task (see C.2.9). However, since the FLUSH procedure increases the length of the codestream, and frequent termination may be desirable, other techniques may be employed. Any technique that places all of the needed bytes in the codestream in such a way that the decoder need not backtrack to find the position at which the next segment of the codestream should begin is acceptable. + +When the predictable termination flag is set (see COD and COC in A.6.1 and A.6.2 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004), the following termination procedure shall be used. Using the notation of C.2, the following steps can be used: + +- 1) Identify the number of bits in code register, C, which must be pushed out through the byte buffer. This is given by $k = (11 - CT) + 1$ . +- 2) While ( $k > 0$ ): + - shift C left by CT and set $CT = 0$ . + +- execute the BYTEOUT procedure. This sets CT equal to the number of bits cleared out of the C register. + - subtract CT from k. +- 3) Execute the BYTEOUT procedure to push the contents of the byte buffer register out to the codestream. This step shall be skipped if the byte in the byte buffer has a 0xFF byte value. + +The relevant truncation length in this case is simply the total number of bytes pushed out onto the codestream. + +If the predictable termination flag is not set, the last byte output by the above procedure can generally be modified, within certain bounds, without affecting the symbols to be decoded. It will sometimes be possible to augment the last byte to the special value, 0xFF, which shall not be sent. It can be shown that this happens approximately 1/8 of the time. + +#### D.4.3 Length computation + +To include coding pass compressed image data into packets, the number of bytes to be included must be determined. If the coding pass compressed image data is terminated, the algorithm in the previous clause may be used. Otherwise, the encoder should calculate a suitable length such that corresponding bytes are sufficient for the decoder to reconstruct the coding passes. + +### D.5 Error resilience segmentation symbol + +A segmentation symbol is a special symbol. Whether it is used or not is signalled in the COD or COC marker segments (see A.6.1 and A.6.2 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004). The symbol is coded with the UNIFORM context of the arithmetic coder at the end of each bit-plane. The correct decoding of this symbol confirms the correctness of the decoding of this bit-plane, which allows error detection. At the encoder, a segmentation symbol 1010 or 0xA should be encoded at the end of each bit-plane (at the end of a cleanup pass). If the segmentation symbol is not decoded correctly at the decoder, then bit errors occurred for this bit-plane. + +NOTE – This can be used with or without the predictable termination. + +### D.6 Selective arithmetic coding bypass + +This style of coding allows bypassing the arithmetic coder for the significance propagation pass and magnitude refinement coding passes starting in the fifth significant bit-plane of the code-block. The COD or COC marker signals whether or not this coding style is used (see A.6.1 and A.6.2 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004). + +The first cleanup pass (which is the first bit-plane of a code-block with a non-zero element) and the next three sets of significance propagation, magnitude refinement, and cleanup coding passes are encoded with the arithmetic coder. The fourth cleanup pass shall include an arithmetic coder termination (see Table D.9). + +**Table D.9 – Selective arithmetic coding bypass** + +| Bit-plane number | Pass type | Coding operations | +|------------------|--------------------------|------------------------| +| 1 | cleanup | Arithmetic Coding (AC) | +| 2 | significance propagation | AC | +| 2 | magnitude refinement | AC | +| 2 | cleanup | AC | +| 3 | significance propagation | AC | +| 3 | magnitude refinement | AC | +| 3 | cleanup | AC | +| 4 | significance propagation | AC | +| 4 | magnitude refinement | AC | +| 4 | cleanup | AC, terminate | +| 5 | significance propagation | raw | +| 5 | magnitude refinement | raw, terminate | +| 5 | cleanup | AC, terminate | +| ... | ... | ... | +| final | significance | raw | +| final | magnitude refinement | raw, terminate | +| final | cleanup | AC, terminate | + +Starting with the fourth significance propagation and magnitude refinement coding passes, the bits that would have been provided to the arithmetic coder are instead provided directly to the bit stream. After each magnitude refinement pass, the bit stream has been "terminated" by padding to the byte boundary. + +When the predictable termination flag is set (see COD and COC in A.6.1 and A.6.2 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004) and all the bits from a magnitude refinement pass have been assembled, any remaining bits in the last byte are filled with an alternating sequence of 0s and 1s. This sequence should start with a 0 regardless of the number of bits to be padded. + +When the termination on each coding pass flag is set (see COD and COC in A.6.1 and A.6.2 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004), then the significance propagation passes are terminated in the same way as the magnitude refinement passes. + +The cleanup coding passes continue to provide compressed image data directly to the arithmetic coder and are always terminated. + +The sign bit is computed with Equation (D-2): + +$$raw\_value = signbit \quad (D-2)$$ + +where $raw\_value = 1$ is a negative sign bit and $raw\_value = 0$ is a positive sign bit. Table D.9 shows the coding sequence. + +The length of each terminated segment, plus the length of any remaining unterminated passes, is signalled in the packet header as described in B.10.7 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004. If termination on each coding pass is selected (see A.6.1 and A.6.2 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004), then every pass is terminated (including both raw passes). + +NOTE 1 – Using the selective bypass mode when encoding an image with an ROI may significantly decrease the compression efficiency. + +Bits are packed into bytes from the most significant bit to the least significant bit. Once a complete byte is assembled, it is emitted to the bit stream. If the value of the byte is a 0xFF a single zero bit is stuffed into the most significant bit of the next byte. Once all bits of the coding pass have been assembled, the last byte is packed to the byte boundary and emitted. The last byte shall not be a 0xFF value. + +At the decoder, if a 0xFF value is encountered in the bit stream, then the first bit of the next byte is discarded. The sequence of bits used in the selective arithmetic coding bypass have been stuffed into bytes using a bit-stuffing routine. + +NOTE 2 – Since the decoder appends 0xFF values, as necessary, to the bit stream representing the coding pass (see D.4.1), truncation of the bit stream may be possible. When the predictable termination flag is set (see COD and COC in A.6.1 and A.6.2 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004), such truncation is not permitted. The last byte cannot be an 0xFF, since the bit-stuffing routine appends a new byte following the FF, having most significant bit value of 0 and unused bits filled with the alternating sequence of 0 and 1 value bits. + +### **D.7 Vertically causal context formation** + +This style of coding constrains the context formation to the current and past code-block scans (four rows of vertically scanned coefficients). That is, any coefficient from the next code-block scan are considered to be insignificant. The COD or COC marker signals whether or not this style of coding is used (see A.6.1 and A.6.2 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004). + +To illustrate, the bit labelled 14 in Figure D.1 is encoded as usual using the neighbour states as specified in Figure D.2, independent of whether or not contexts are vertically causal. However when vertically causal context formation is used, the bit labelled 15 is encoded assuming $D_2 = V_1 = D_3 = 0$ in Figure D.2. + +### **D.8 Flow diagram of the code-block coding** + +The steps for modelling each bit-plane of each code-block can be viewed graphically in Figure D.3. The decisions made are in Table D.10 and the bits and context sent to the coder are in Table D.11. These show the context without the selective arithmetic coding bypass or the vertically causal model. + +![Flow chart for all coding passes on a code-block bit-plane. The chart starts with 'Start of significance propagation' and 'Start coding passes for a code-block bit-plane'. It branches into three main sections: significance propagation, magnitude refinement, and cleanup. The significance propagation section includes decisions D1, D2, D3, D4, and D7, leading to contexts C1, C2, and C0. The magnitude refinement section includes decisions D5, D6, and D7, leading to context C3. The cleanup section includes decisions D8, D9, D10, D11, and D12, leading to contexts C4, C5, C2, C0, and C1. The process ends with 'End of coding passes for a code-block bit-plane'.](cc72b4769f15fe33763025416c1e274d_img.jpg) + +``` + +graph TD + Start[Start coding passes for a code-block bit-plane] --> D0{D0} + D0 -- No --> D1{D1} + D0 -- Yes --> Cleanup[Start of cleanup pass] + + D1 -- Yes --> D2{D2} + D1 -- No --> D2 + D2 -- Yes --> C1[C1] + D2 -- No --> D3{D3} + D3 -- Yes --> C2[C2] + D3 -- No --> D4{D4} + D4 -- Yes --> C0[C0] + D4 -- No --> D5{D5} + + D5 -- Yes --> D6{D6} + D5 -- No --> D6 + D6 -- Yes --> C3[C3] + D6 -- No --> D7{D7} + D7 -- Yes --> C0 + D7 -- No --> Cleanup + + Cleanup --> D8{D8} + D8 -- Yes --> C4[C4] + D8 -- No --> D9{D9} + D9 -- Yes --> C1 + D9 -- No --> D3 + D3 -- Yes --> C2 + D3 -- No --> D10{D10} + D10 -- Yes --> C0 + D10 -- No --> D11{D11} + D11 -- Yes --> C5[C5] + D11 -- No --> C2 + C5 --> C2 + C2 --> D10 + D10 -- Yes --> C0 + C0 --> C1 + C1 --> D3 + D3 -- No --> D12{D12} + D12 -- Yes --> C0 + D12 -- No --> End[End of coding passes for a code-block bit-plane] + +``` + +Flow chart for all coding passes on a code-block bit-plane. The chart starts with 'Start of significance propagation' and 'Start coding passes for a code-block bit-plane'. It branches into three main sections: significance propagation, magnitude refinement, and cleanup. The significance propagation section includes decisions D1, D2, D3, D4, and D7, leading to contexts C1, C2, and C0. The magnitude refinement section includes decisions D5, D6, and D7, leading to context C3. The cleanup section includes decisions D8, D9, D10, D11, and D12, leading to contexts C4, C5, C2, C0, and C1. The process ends with 'End of coding passes for a code-block bit-plane'. + +T.812(07)\_F-D3 + +Figure D.3 – Flow chart for all coding passes on a code-block bit-plane + +Table D.10 – Decisions in the context model flow chart + +| Decision | Question | Description | +|----------|-------------------------------------------------------------------------------------------------------------------|-------------| +| D0 | Is this the first significant bit-plane for the code-block? | See D.3 | +| D1 | Is the current coefficient significant? | See D.3.1 | +| D2 | Is the context bin zero? (see Table D.1) | See D.3.1 | +| D3 | Did the current coefficient just become significant? | See D.3.1 | +| D4 | Are there more coefficients in the significance propagation? | | +| D5 | Is the coefficient insignificant? | See D.3.3 | +| D6 | Was the coefficient coded in the last significance propagation? | See D.3.3 | +| D7 | Are there more coefficients in the magnitude refinement pass? | | +| D8 | Are four contiguous undecoded coefficients in a column each with a 0 context? | See D.3.4 | +| D9 | Is the coefficient significant or has the bit already been coded during the Significance Propagation coding pass? | See D.3.4 | +| D10 | Are there more coefficients remaining of the four column coefficients? | | +| D11 | Are the four contiguous bits all zero? | See D.3.4 | +| D12 | Are there more coefficients in the cleanup pass? | | + +Table D.11 – Decoding in the context model flow chart + +| Code | Decoded symbol | Context | Brief explanation | Description | +|------|--------------------------|--------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------| +| C0 | – | – | Go to the next coefficient or column | | +| C1 | Newly significant? | Table D.1,
9 context labels | Decode significance bit of current coefficient
(significance propagation or cleanup) | See D.3.1 | +| C2 | Sign bit | Table D.3,
5 context labels | Decode sign bit of current coefficient | See D.3.2 | +| C3 | Current magnitude
bit | Table D.4,
3 context labels | Decode magnitude refinement pass bit of current
coefficient | See D.3.3 | +| C4 | 0
1 | Run-length context
label | Decode run-length of four zeros
Decode run-length not of four zeros | See D.3.4 | +| C5 | 00
01
10
11 | UNIFORM | First coefficient is first with non-zero bit
Second coefficient is first with non-zero bit
Third coefficient is first with non-zero bit
Fourth coefficient is first with non-zero bit | See D.3.4 and
Table C.2 | + +## Annex E + +## Quantization + +(This annex forms an integral part of this Recommendation | International Standard) + +In this annex and all of its subclauses, the flow charts and tables are normative only in the sense that they are defining an output that alternative implementations shall duplicate. + +This annex specifies the quantization of transform coefficients for encoding. Quantization is the process by which the transform coefficients are reduced in precision. + +### E.1 Inverse quantization procedure (Informative) + +For each transform coefficient $(u, v)$ of a given sub-band $b$ , the decoded transform coefficient value $\overline{q}_b(u, v)$ is given by the following equation: + +$$\overline{q}_b(u, v) = (1 - 2s_b(u, v)) \cdot \left( \sum_{i=1}^{N_b(u, v)} MSB_i(b, u, v) \cdot 2^{M_b - i} \right) \quad (\text{E-1})$$ + +NOTE 1 – $q_b(u, v)$ is quantized value of $a_b(u, v)$ according to Equation (E-6) and $\overline{q}_b(u, v)$ is inverse quantization value of $q_b(u, v)$ . + +where $s_b(u, v)$ , $N_b(u, v)$ and $MSB_i(b, u, v)$ are given in D.2, and where $M_b$ is retrieved using Equation (E-2), where the number of guard bits $G$ and the exponent $\varepsilon_b$ are specified in the QCD or QCC marker segments (see A.6.4 and A.6.5 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004). + +$$M_b = G + \varepsilon_b - 1 \quad (\text{E-2})$$ + +Each decoded transform coefficient $q_b(u, v)$ of sub-band $b$ is used to generate a reconstructed transform coefficient $Rq_b(u, v)$ , as will be described in E.1.1. + +NOTE 2 – Encoding only $N_b(u, v)$ (see D.2.1) bit-planes is equivalent to encoding data which has been encoded using a scalar quantizer with step size $2^{M_b - N_b(u, v)} \cdot \Delta_b$ for all the coefficients of this code-block. Due to the nature of the three coding passes (see D.3), $N_b(u, v)$ may be different for different coefficients within the same code-block. + +#### E.1.1 Determination of the quantization step size in Irreversible transformation + +For the irreversible transformation, the quantization step size $\Delta_b$ for a given sub-band $b$ is calculated from the dynamic range $R_b$ of sub-band $b$ , the exponent $\varepsilon_b$ and mantissa $\mu_b$ as given in Equation (E-3). + +$$\Delta_b = 2^{R_b - \varepsilon_b} \left( 1 + \frac{\mu_b}{2^{11}} \right) \quad (\text{E-3})$$ + +NOTE 1 – The denominator, $2^{11}$ , in Equation (E-3) is due to the allocation of 11 bits in the codestream for $\mu_b$ , as given in Table A.30 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004. + +In Equation (E-3), the exponent $\varepsilon_b$ and the mantissa $\mu_b$ are specified in the QCD or QCC marker segments (see A.6.4 and A.6.5 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004), and the nominal dynamic range $R_b$ (as given by Equation (E-4)) is the sum of $R_l$ (the number of bits used to represent the original tile-component samples which can be extracted from the SIZ marker – see Table A.11 in A.5.1 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004) and the base 2 exponent of the sub-band gain ( $gain_b$ ) of the current sub-band $b$ , which varies with the type of sub-band $b$ (*levLL*, *levLH* or *levHL*, *levHH* – see F.3.1) and can be found in Table E.1. + +Table E.1 – Sub-band gains + +| sub-band $b$ | gain b | log 2 (gain b ) | +|--------------|--------------------------------|----------------------------------------------------| +| levLL | 1 | 0 | +| levLH | 2 | 1 | +| levHL | 2 | 1 | +| levHH | 4 | 2 | + +$$R_b = R_I + \log_2(\text{gain}_b) \quad (\text{E-4})$$ + +The exponent/mantissa pairs $(\varepsilon_b, \mu_b)$ are either signalled in the codestream for every sub-band (expounded quantization) or else signalled only for the $N_{LL}$ sub-band and derived for all other sub-bands (derived quantization) (see Table A.30 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004). In the case of derived quantization, all exponent/mantissa pairs $(\varepsilon_b, \mu_b)$ are derived from the single exponent/mantissa pair $(\varepsilon_o, \mu_o)$ corresponding to the $N_{LL}$ sub-band, according to Equation (E-5): + +$$(\varepsilon_b, \mu_b) = (\varepsilon_o - N_L + n_b, \mu_o) \quad (\text{E-5})$$ + +where $n_b$ denotes the number of decomposition levels from the original tile-component to the sub-band $b$ . + +NOTE 2 – For a given sub-band $b$ , a quantized transform coefficient may exceed the dynamic range $R_b$ . + +#### E.1.2 Determination of the quantization step size in reversible transformation + +For the reversible transformation, the quantization step size $\Delta_b$ is equal to one (no quantization is performed). + +### E.2 Scalar coefficient quantization + +For irreversible compression, after the irreversible forward discrete wavelet transformation (see Annex F), each of the transform coefficients $a_b(u, v)$ of the sub-band is quantized to the value $q_b(u, v)$ according to Equation (E-6). + +$$q_b(u, v) = \text{sign}(a_b(u, v)) \cdot \left\lfloor \frac{|a_b(u, v)|}{\Delta_b} \right\rfloor \quad (\text{E-6})$$ + +where $\Delta_b$ is the quantization step size. The exponent $\varepsilon_b$ and mantissa corresponding to $\Delta_b$ can be derived from Equation (E-5), and must be recorded in the codestream in the QCD or QCC markers (see A.6.4 and A.6.5 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004). + +For reversible compression, the quantization step size is required to be 1. In this case, a parameter $\varepsilon_b$ has to be recorded in the codestream in the QCD or QCC markers (see A.6.4 and A.6.5 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004), and is calculated as: + +$$\varepsilon_b = R_I + \log_2(\text{gain}_b) + \zeta_c \quad (\text{E-7})$$ + +where $R_I$ and $\text{gain}_b$ are as described in E.1.1, and where $\zeta_c$ is zero if the RCT is not used and $\zeta_c$ is the number of additional bits added by the RCT if the RCT is used, as described in G.2. + +For both reversible and irreversible compression, in order to prevent possible overflow or excursion beyond the nominal range of the integer representation of $|q_b(u, v)|$ arising, for example during floating point calculations, the number $M_b$ of bits for the integer representation of $q_b(u, v)$ used at the encoder side is defined by Equation (E-2). The number $G$ of guard bits has to be specified in the QCD or QCC marker (see A.6.4 and A.6.5 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004). Typical values for the number of guard bits are $G = 1$ or $G = 2$ . + +## Annex F + +## Discrete wavelet transformation of tile-components + +(This annex forms an integral part of this Recommendation | International Standard) + +In this annex, the flow charts and tables are normative only in the sense that they are defining an output that alternative implementations shall duplicate. + +This annex describes the forward discrete wavelet transformation applied to one tile-component. + +### F.1 Tile-component parameters + +Consider the tile-component defined by the coordinates, $tcx_0$ , $tcx_1$ , $tcy_0$ and $tcy_1$ given in Equation (B-12) in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004, are reproduced herein: + +$$tcx_0 = \left\lceil \frac{tx_0}{XR_{siz}^i} \right\rceil \quad tcx_1 = \left\lceil \frac{tx_1}{XR_{siz}^i} \right\rceil \quad tcy_0 = \left\lceil \frac{ty_0}{YR_{siz}^i} \right\rceil \quad tcy_1 = \left\lceil \frac{ty_1}{YR_{siz}^i} \right\rceil$$ + +Then the coordinates $(x, y)$ of the tile-component (with sample values $I(x, y)$ ) lie in the range defined by: + +$$tcx_0 \leq x < tcx_1 \quad \text{and} \quad tcy_0 \leq y < tcy_1 \quad (\text{F-1})$$ + +### F.2 Discrete wavelet transformations + +#### F.2.1 Low-pass and high-pass filtering + +To perform the forward discrete wavelet transformation (FDWT), this Recommendation | International Standard uses a one-dimensional sub-band decomposition of a one-dimensional array of samples into low-pass coefficients, representing a downsampled low-resolution version of the original array, and high-pass coefficients, representing a downsampled residual version of the original array, needed to perfectly reconstruct the original array from the low-pass array. + +#### F.2.2 Decomposition levels + +Each tile-component is transformed into a set of two-dimensional sub-band signals (called sub-bands), each representing the activity of the signal in various frequency bands, at various spatial resolutions. $N_L$ denotes the number of decomposition levels. + +#### F.2.3 Discrete wavelet filters + +This Recommendation | International Standard specifies one reversible transformation and one irreversible transformation. Given that tile-component samples are integer-valued, a reversible transformation requires the specification of a rounding procedure for intermediate non-integer-valued transform coefficients. + +### F.3 Forward transformation + +#### F.3.1 The FDWT procedure + +The forward discrete wavelet transformation (FDWT) transforms DC-level shifted tile-component samples $I(x, y)$ into a set of sub-bands with coefficients $a_b(u_b, v_b)$ (FDWT procedure). The FDWT procedure (see Figure F.1) also takes as input the number of decomposition levels $N_L$ signalled in the COD or COC markers (see A.6.1 and A.6.2 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004). + +![Block diagram of the FDWT procedure. Two inputs, I(x, y) and N_L, enter a block labeled FDWT from the left. Three outputs exit the block to the right, labeled a_b(u_b, v_b).](58f0b869e4401281f67c1cacbd493a4a_img.jpg) + +``` + +graph LR + Ixy[I(x, y)] --> FDWT[FDWT] + NL[N_L] --> FDWT + FDWT --> abuvb[a_b(u_b, v_b)] + +``` + +T.812(07)\_F-F1 + +Block diagram of the FDWT procedure. Two inputs, I(x, y) and N\_L, enter a block labeled FDWT from the left. Three outputs exit the block to the right, labeled a\_b(u\_b, v\_b). + +Figure F.1 – Inputs and outputs of the FDWT procedure + +As illustrated in Figure F.2, all the sub-bands in the case where $N_L = 2$ can be represented in the following way: + +![Figure F.2: The FDWT (N_L = 2). A block diagram showing the decomposition of an input image I(x, y) into sub-bands. The input I(x, y) is processed by an FDWT block. The output is a 2x2 grid of sub-bands: a_{2LL}(u_{2LL}, v_{2LL}), a_{2HL}(u_{2HL}, v_{2HL}), a_{2LH}(u_{2LH}, v_{2LH}), and a_{2HH}(u_{2HH}, v_{2HH}). These are further decomposed into a_{1LL}(u_{1LL}, v_{1LL}) and a_{1HL}(u_{1HL}, v_{1HL}) on the left, and a_{1LH}(u_{1LH}, v_{1LH}) and a_{1HH}(u_{1HH}, v_{1HH}) on the right. The diagram is labeled T.812(07)_F-F2.](f5a5f52bc25d95a7f616290c99e88ae6_img.jpg) + +Figure F.2: The FDWT (N\_L = 2). A block diagram showing the decomposition of an input image I(x, y) into sub-bands. The input I(x, y) is processed by an FDWT block. The output is a 2x2 grid of sub-bands: a\_{2LL}(u\_{2LL}, v\_{2LL}), a\_{2HL}(u\_{2HL}, v\_{2HL}), a\_{2LH}(u\_{2LH}, v\_{2LH}), and a\_{2HH}(u\_{2HH}, v\_{2HH}). These are further decomposed into a\_{1LL}(u\_{1LL}, v\_{1LL}) and a\_{1HL}(u\_{1HL}, v\_{1HL}) on the left, and a\_{1LH}(u\_{1LH}, v\_{1LH}) and a\_{1HH}(u\_{1HH}, v\_{1HH}) on the right. The diagram is labeled T.812(07)\_F-F2. + +**Figure F.2 – The FDWT ( $N_L = 2$ )** + +The FDWT procedure starts with the initialization of the variable $lev$ (the current decomposition level) to zero, and setting the sub-band $a_{0LL}(u_{0LL}, v_{0LL})$ to the input array $I(u, v)$ . The 2D\_SD procedure is performed at every level $lev$ , where the level $lev$ increases by one at each iteration, and until $N_L$ iterations are performed. The 2D\_SD procedure is iterated over the $levLL$ sub-band produced at each iteration. + +As defined in Annex B (see Equation (B-15) in Annex B in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004), the coordinates of the sub-band $a_{levLL}(u, v)$ lie in the range defined by: + +$$tbx_0 \leq u < tbx_1 \quad \text{and} \quad tby_0 \leq v < tby_1 \quad (\text{F-2})$$ + +Figure F.3 describes the FDWT procedure. + +![Figure F.3: The FDWT procedure. A flowchart showing the iterative process. It starts with an oval 'FDWT', followed by a rectangle 'lev 1 = a_{0LL}(u, v) = I(u, v)'. A decision diamond 'lev > N_L?' follows. If 'Yes', it goes to an oval 'Done'. If 'No', it goes to a rectangle containing the equation (a_{levLL}, a_{levHL}, a_{levLH}, a_{levHH}) = 2D_SD(a_{(lev-1)LL}, u_0, u_1, v_0, v_1). This is followed by a rectangle 'lev = lev + 1', which loops back to the decision diamond. The diagram is labeled T.812(07)_F-F3.](09e20a17ecd8042b3d9b7fd462f2d9b4_img.jpg) + +Figure F.3: The FDWT procedure. A flowchart showing the iterative process. It starts with an oval 'FDWT', followed by a rectangle 'lev 1 = a\_{0LL}(u, v) = I(u, v)'. A decision diamond 'lev > N\_L?' follows. If 'Yes', it goes to an oval 'Done'. If 'No', it goes to a rectangle containing the equation (a\_{levLL}, a\_{levHL}, a\_{levLH}, a\_{levHH}) = 2D\_SD(a\_{(lev-1)LL}, u\_0, u\_1, v\_0, v\_1). This is followed by a rectangle 'lev = lev + 1', which loops back to the decision diamond. The diagram is labeled T.812(07)\_F-F3. + +**Figure F.3 – The FDWT procedure** + +#### F.3.2 The 2D\_SD procedure + +The 2D\_SD procedure performs a decomposition of a two-dimensional array of coefficients or samples $a_{(lev-1)LL}(u, v)$ into four groups of sub-band coefficients $a_{levLL}(u, v)$ , $a_{levHL}(u, v)$ , $a_{levLH}(u, v)$ , and $a_{levHH}(u, v)$ . + +The total number of coefficients of the $lev_{LL}$ sub-band is equal to the sum of the total number of coefficients of the four sub-bands resulting from the 2D\_SD procedure. + +Figure F.4 describes the input and output parameters of the 2D\_SD procedure. + +![Figure F.4: Inputs and outputs of the 2D_SD procedure. A block labeled '2D_SD' has two inputs on the left: a top input labeled a_{(lev-1)LL} and a bottom input labeled u_0, u_1, v_0, v_1. It has four outputs on the right: a_{levLL}, a_{levHL}, a_{levLH}, and a_{levHH}.](67d03c9e89620d73e3786c869e559752_img.jpg) + +Figure F.4: Inputs and outputs of the 2D\_SD procedure. A block labeled '2D\_SD' has two inputs on the left: a top input labeled a\_{(lev-1)LL} and a bottom input labeled u\_0, u\_1, v\_0, v\_1. It has four outputs on the right: a\_{levLL}, a\_{levHL}, a\_{levLH}, and a\_{levHH}. + +Figure F.4 – Inputs and outputs of the 2D\_SD procedure + +Figure F.5 illustrates the sub-band decomposition performed by the 2D\_SD procedure. + +![Figure F.5: One-level decomposition into four sub-bands (2D_SD procedure). A box on the left labeled a_{(lev-1)LL} has an arrow labeled '2D_SD' pointing to a 2x2 grid of boxes on the right. The top-left box is a_{levLL}, top-right is a_{levHL}, bottom-left is a_{levLH}, and bottom-right is a_{levHH}.](a97518a839da75f8379c578562b01bc2_img.jpg) + +Figure F.5: One-level decomposition into four sub-bands (2D\_SD procedure). A box on the left labeled a\_{(lev-1)LL} has an arrow labeled '2D\_SD' pointing to a 2x2 grid of boxes on the right. The top-left box is a\_{levLL}, top-right is a\_{levHL}, bottom-left is a\_{levLH}, and bottom-right is a\_{levHH}. + +Figure F.5 – One-level decomposition into four sub-bands (2D\_SD procedure) + +The 2D\_SD procedure first applies the VER\_SD procedure to all columns of $a(u, v)$ . It then applies the HOR\_SD procedure to all rows of $a(u, v)$ . The coefficients thus obtained from $a(u, v)$ are deinterleaved into the four sub-bands using the 2D\_DEINTERLEAVE procedure. + +Figure F.6 describes the 2D\_SD procedure. + +![Figure F.6: The 2D_SD procedure flowchart. It starts with an oval labeled '2D_SD'. An arrow points down to a rectangle labeled 'a = VER_SD(a_{(lev-1)LL}, u_0, u_1, v_0, v_1)'. Another arrow points down to a rectangle labeled 'a = HOR_SD(a, u_0, u_1, v_0, v_1)'. A third arrow points down to a wide rectangle labeled '(a_{levLL}, a_{levHL}, a_{levLH}, a_{levHH}) = 2D_DEINTERLEAVE(a, u_0, u_1, v_0, v_1)'. A final arrow points down to an oval labeled 'Done'.](18d8d7c537faf9057bd1fe0e7d152d7f_img.jpg) + +Figure F.6: The 2D\_SD procedure flowchart. It starts with an oval labeled '2D\_SD'. An arrow points down to a rectangle labeled 'a = VER\_SD(a\_{(lev-1)LL}, u\_0, u\_1, v\_0, v\_1)'. Another arrow points down to a rectangle labeled 'a = HOR\_SD(a, u\_0, u\_1, v\_0, v\_1)'. A third arrow points down to a wide rectangle labeled '(a\_{levLL}, a\_{levHL}, a\_{levLH}, a\_{levHH}) = 2D\_DEINTERLEAVE(a, u\_0, u\_1, v\_0, v\_1)'. A final arrow points down to an oval labeled 'Done'. + +Figure F.6 – The 2D\_SD procedure + +#### F.3.3 The VER\_SD procedure + +The VER\_SD procedure performs a vertical sub-band decomposition of a two-dimensional array of coefficients. It takes as input the two-dimensional array $a_{(lev-1)LL}(u, v)$ , the horizontal and vertical extent of its coefficients as indicated by $u_0 \leq u < u_1$ and $v_0 \leq v < v_1$ (see Figure F.7) and produces as output a vertically filtered version $a(u, v)$ of the input array, column by column. The values of $u_0, u_1, v_0, v_1$ used by the VER\_SD procedure are those of $tbx_0, tbx_1, tby_0, tby_1$ corresponding to sub-band $b = (lev-1)LL$ (see definition in Equation (B-15) in Annex B in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004). + +![Figure F.7: Inputs and outputs of the VER_SD procedure. A block diagram showing a process box labeled 'VER_SD'. Two input arrows on the left: the top one is labeled 'a(u, v)' and the bottom one is labeled 'u_0, u_1, v_0, v_1'. A single output arrow on the right is labeled 'a(u, v)'.](6cc85a2b62fd8a2a3faab29730f20e81_img.jpg) + +T.812(07)\_F-F7 + +Figure F.7: Inputs and outputs of the VER\_SD procedure. A block diagram showing a process box labeled 'VER\_SD'. Two input arrows on the left: the top one is labeled 'a(u, v)' and the bottom one is labeled 'u\_0, u\_1, v\_0, v\_1'. A single output arrow on the right is labeled 'a(u, v)'. + +Figure F.7 – Inputs and outputs of the VER\_SD procedure + +As illustrated in Figure F.8, the VER\_SD procedure applies the one-dimensional sub-band decomposition (1D\_SD procedure) to each column of the input array $a(u, v)$ , and stores the result back into each column. + +![Figure F.8: The VER_SD procedure flowchart. It starts with an oval 'VER_SD', followed by a rectangle 'u = u_0, i_0 = v_0, i_1 = v_1'. Then a rectangle 'X(v) = a(u, v)', then a rectangle 'Y(v) = 1D_SD(X(v), i_0, i_1)' (shaded), then 'a(u, v) = Y(v)', then 'u = u + 1', then a decision diamond 'u ≥ u_1?'. The 'No' branch loops back to before 'X(v) = a(u, v)'. The 'Yes' branch leads to an oval 'Done'.](a161a2bbb4d830e847ccb4f44b7e41a9_img.jpg) + +T.812(07)\_F-F8 + +Figure F.8: The VER\_SD procedure flowchart. It starts with an oval 'VER\_SD', followed by a rectangle 'u = u\_0, i\_0 = v\_0, i\_1 = v\_1'. Then a rectangle 'X(v) = a(u, v)', then a rectangle 'Y(v) = 1D\_SD(X(v), i\_0, i\_1)' (shaded), then 'a(u, v) = Y(v)', then 'u = u + 1', then a decision diamond 'u ≥ u\_1?'. The 'No' branch loops back to before 'X(v) = a(u, v)'. The 'Yes' branch leads to an oval 'Done'. + +Figure F.8 – The VER\_SD procedure + +#### F.3.4 The HOR\_SD procedure + +The HOR\_SD procedure performs a horizontal sub-band decomposition of a two-dimensional array of coefficients. It takes as input a two-dimensional array $a(u, v)$ , the horizontal and vertical extent of its coefficients as indicated by $u_0 \leq u < u_1$ and $v_0 \leq v < v_1$ (see Figure F.9) and produces as output a horizontally filtered version of the input array, row by row. + +![Figure F.9: Inputs and outputs of the HOR_SD procedure. A block diagram showing a process box labeled 'HOR_SD'. Two input arrows on the left: the top one is labeled 'a(u, v)' and the bottom one is labeled 'u_0, u_1, v_0, v_1'. A single output arrow on the right is labeled 'a(u, v)'.](48f209b7c0c1f91af40cfc3466dbd534_img.jpg) + +T.812(07)\_F-F9 + +Figure F.9: Inputs and outputs of the HOR\_SD procedure. A block diagram showing a process box labeled 'HOR\_SD'. Two input arrows on the left: the top one is labeled 'a(u, v)' and the bottom one is labeled 'u\_0, u\_1, v\_0, v\_1'. A single output arrow on the right is labeled 'a(u, v)'. + +Figure F.9 – Inputs and outputs of the HOR\_SD procedure + +As illustrated in Figure F.10, the HOR\_SD procedure applies the one-dimensional sub-band decomposition (1D\_SD procedure) to each row of the input array $a(u, v)$ and stores the result back in each row. + +![Flowchart of the HOR_SD procedure](5db6545aedab79741ebae9b27bb363b3_img.jpg) + +``` + +graph TD + Start([HOR_SD]) --> Init[v = v_0 +i_0 = u_0 +i_1 = u_1] + Init --> CalcX[X(u) = a(u, v)] + CalcX --> CalcY[Y(u) = 1D_SD(X(u), i_0, i_1)] + CalcY --> CalcA[a(u, v) = Y(u)] + CalcA --> IncV[v = v + 1] + IncV --> Decision{v ≥ v_1?} + Decision -- No --> CalcX + Decision -- Yes --> End([Done]) + +``` + +T.812(07)\_F-F10 + +Flowchart of the HOR\_SD procedure + +Figure F.10 – The HOR\_SD procedure + +#### F.3.5 The 2D\_DEINTERLEAVE procedure + +As illustrated in Figure F.11, the 2D\_DEINTERLEAVE procedure deinterleaves the coefficients of $a(u, v)$ into four sub-bands. The arrangement is dependent on the coordinates $(u_0, v_0)$ of the first coefficient of $a(u, v)$ . + +The way these sub-bands are formed from the output $a(u, v)$ of the HOR\_SD procedure is described by the 2D\_DEINTERLEAVE procedure illustrated in Figure F.12. + +![Block diagram of the 2D_DEINTERLEAVE procedure](683f755e8456c884716de4fce48c7e63_img.jpg) + +The diagram shows a block labeled "2D\_DEINTERLEAVE". It has two input arrows on the left: the top one is labeled $a(u, v)$ and the bottom one is labeled $u_0, u_1, v_0, v_1$ . It has four output arrows on the right, labeled from top to bottom as $a_{levLL}$ , $a_{levHL}$ , $a_{levLH}$ , and $a_{levHH}$ . + +T.812(07)\_F-F11 + +Block diagram of the 2D\_DEINTERLEAVE procedure + +Figure F.11 – Parameters of 2D\_DEINTERLEAVE procedure + +![Flowchart of the 2D_DEINTERLEAVE procedure. The process starts with a '2D_DEINTERLEAVE' block, branching into four parallel paths based on the value of 'b'. Each path involves calculating a_b(u_b, v_b), incrementing u_b, and checking if u_b is greater than or equal to a limit. If not, it loops back. If yes, it increments v_b and checks if v_b is greater than or equal to a limit. If not, it resets u_b and loops back. If yes, it proceeds to the next path or finishes.](b9c0d46c1148cf65cb79f27fac420981_img.jpg) + +``` + +graph TD + Start([2D_DEINTERLEAVE]) --> B1 + subgraph LL_Path + B1["b = levLL +u_b = ⌈u_0/2⌉ +v_b = ⌈v_0/2⌉"] --> A1["a_b(u_b, v_b) = a(2u_b, 2v_b)"] + A1 --> U1["u_b = u_b + 1"] + U1 --> D1{"u_b ≥ ⌈u_1/2⌉?"} + D1 -- No --> A1 + D1 -- Yes --> V1["v_b = v_b + 1"] + V1 --> D2{"v_b ≥ ⌈v_1/2⌉?"} + D2 -- No --> U1_0["u_b = ⌈u_0/2⌉"] + U1_0 --> A1 + end + D2 -- Yes --> B2 + + subgraph HL_Path + B2["b = levHL +u_b = ⌊u_0/2⌋ +v_b = ⌈v_0/2⌉"] --> A2["a_b(u_b, v_b) = a(2u_b + 1, 2v_b)"] + A2 --> U2["u_b = u_b + 1"] + U2 --> D3{"u_b ≥ ⌊u_1/2⌋?"} + D3 -- No --> A2 + D3 -- Yes --> V2["v_b = v_b + 1"] + V2 --> D4{"v_b ≥ ⌈v_1/2⌉?"} + D4 -- No --> U2_0["u_b = ⌊u_0/2⌋"] + U2_0 --> A2 + end + D4 -- Yes --> B3 + + subgraph LH_Path + B3["b = levLH +u_b = ⌈u_0/2⌉ +v_b = ⌊v_0/2⌋"] --> A3["a_b(u_b, v_b) = a(2u_b, 2v_b + 1)"] + A3 --> U3["u_b = u_b + 1"] + U3 --> D5{"u_b ≥ ⌈u_1/2⌉?"} + D5 -- No --> A3 + D5 -- Yes --> V3["v_b = v_b + 1"] + V3 --> D6{"v_b ≥ ⌊v_1/2⌋?"} + D6 -- No --> U3_0["u_b = ⌈u_0/2⌉"] + U3_0 --> A3 + end + D6 -- Yes --> B4 + + subgraph HH_Path + B4["b = levHH +u_b = ⌊u_0/2⌋ +v_b = ⌊v_0/2⌋"] --> A4["a_b(u_b, v_b) = a(2u_b + 1, 2v_b + 1)"] + A4 --> U4["u_b = u_b + 1"] + U4 --> D7{"u_b ≥ ⌊u_1/2⌋?"} + D7 -- No --> A4 + D7 -- Yes --> V4["v_b = v_b + 1"] + V4 --> D8{"v_b ≥ ⌊v_1/2⌋?"} + D8 -- No --> U4_0["u_b = ⌊u_0/2⌋"] + U4_0 --> A4 + end + D8 -- Yes --> Done([Done]) + +``` + +T.812(07)\_F-F12 + +Flowchart of the 2D\_DEINTERLEAVE procedure. The process starts with a '2D\_DEINTERLEAVE' block, branching into four parallel paths based on the value of 'b'. Each path involves calculating a\_b(u\_b, v\_b), incrementing u\_b, and checking if u\_b is greater than or equal to a limit. If not, it loops back. If yes, it increments v\_b and checks if v\_b is greater than or equal to a limit. If not, it resets u\_b and loops back. If yes, it proceeds to the next path or finishes. + +Figure F.12 – The 2D\_DEINTERLEAVE procedure + +#### F.3.6 The 1D\_SD procedure + +As illustrated in Figure F.13, the 1D\_SD procedure takes as input a one-dimensional array $X(i)$ , the extent of its coefficients as indicated by $i_0 \leq i < i_1$ . It produces as output an array $Y(i)$ , with the same indices $(i_0, i_1)$ . + +![Block diagram of the 1D_SD procedure. An input array X and indices i_0, i_1 are fed into a block labeled 1D_SD. The output of the block is an array Y.](73b28b0f5e3be628bb5a3d6bd1d79d21_img.jpg) + +``` + +graph LR + X --> 1D_SD[1D_SD] + i0_i1["i_0, i_1"] --> 1D_SD + 1D_SD --> Y + +``` + +T.812(07)\_F-F13 + +Block diagram of the 1D\_SD procedure. An input array X and indices i\_0, i\_1 are fed into a block labeled 1D\_SD. The output of the block is an array Y. + +Figure F.13 – Parameters of the 1D\_SD procedure + +For signals of length one (i.e., $i_0 = i_1 - 1$ ), the 1D\_SD procedure sets the value of $Y(i_0)$ to $Y(i_0) = X(i_0)$ if $i_0$ is an even integer, and to $Y(i_0) = 2X(i_0)$ if $i_0$ is an odd integer. + +For signals of length greater than or equal to two (i.e., $i_0 < i_1 - 1$ ), as illustrated in Figure F.14, the 1D\_SD procedure first uses the 1D\_EXTD procedure to extend the signal $X$ beyond its left and right boundaries resulting in the extended signal $X_{ext}$ , and then uses the 1D\_FILTD procedure to filter the extended signal $X_{ext}$ and produce the desired filtered signal $Y$ . + +![Flowchart of the 1D_SD procedure. It starts with a rounded rectangle labeled '1D_SD'. An arrow points down to a rectangle labeled 'X_ext = 1D_EXTD (X, i_0, i_1)'. Another arrow points down to a rectangle labeled 'Y_ext = 1D_FILTD (X_ext, i_0, i_1)'. A final arrow points down to a rounded rectangle labeled 'Done'. The reference T.812(07)_F-F14 is shown to the right of the 'Done' box.](8d66c9c295023a1380f9986d3663bb1e_img.jpg) + +``` + +graph TD + A([1D_SD]) --> B[X_ext = 1D_EXTD (X, i_0, i_1)] + B --> C[Y_ext = 1D_FILTD (X_ext, i_0, i_1)] + C --> D([Done]) + +``` + +Flowchart of the 1D\_SD procedure. It starts with a rounded rectangle labeled '1D\_SD'. An arrow points down to a rectangle labeled 'X\_ext = 1D\_EXTD (X, i\_0, i\_1)'. Another arrow points down to a rectangle labeled 'Y\_ext = 1D\_FILTD (X\_ext, i\_0, i\_1)'. A final arrow points down to a rounded rectangle labeled 'Done'. The reference T.812(07)\_F-F14 is shown to the right of the 'Done' box. + +Figure F.14 – The 1D\_SD procedure + +#### F.3.7 The 1D\_EXTD procedure + +The 1D\_EXTD procedure is identical to the 1D\_EXTR procedure, except for the values of the $i_{left9-7}$ , $i_{right9-7}$ , $i_{left5-3}$ and $i_{right5-3}$ parameters, which are given in Tables F.1 and F.2. + +Table F.1 – Extension to the left + +| $i_0$ | $i_{left5-3}$ | $i_{left9-7}$ | +|-------|---------------|---------------| +| even | 2 | 4 | +| odd | 1 | 3 | + +Table F.2 – Extension to the right + +| $i_1$ | $i_{right5-3}$ | $i_{right9-7}$ | +|-------|----------------|----------------| +| odd | 2 | 4 | +| even | 1 | 3 | + +#### F.3.8 The 1D\_FILTD procedure + +This Recommendation | International Standard specifies one irreversible procedure (1D\_FILTD9-7I) and one reversible filtering procedure (1D\_FILTD5-3R), depending on whether the 9-7 irreversible or 5-3 reversible wavelet transformation is selected. + +As illustrated in Figure F.15, both procedures take as input an extended 1D signal $X_{ext}$ , the index of the first coefficient $i_0$ , and the index of the coefficient $i_1$ immediately following the last coefficient ( $i_1 - 1$ ). They both produce an output signal, $Y$ . The even-indexed coefficients of the $Y$ signal are a low-pass downsampled version of the extended signal $X_{ext}$ , while the odd-indexed coefficients of the signal $Y$ are a high-pass downsampled version of the extended signal $X_{ext}$ . + +![Block diagram of the 1D_FILTD procedure. Two input arrows labeled 'X_ext' and 'i_0, i_1' enter a rectangular block labeled '1D_FILTD'. An output arrow labeled 'Y' exits the block to the right. The reference T.812(07)_F-F15 is shown to the right of the block.](901800172164e0494762ffa57a09993f_img.jpg) + +``` + +graph LR + X_ext[X_ext] --> 1D_FILTD[1D_FILTD] + i_0_i_1[i_0, i_1] --> 1D_FILTD + 1D_FILTD --> Y[Y] + +``` + +Block diagram of the 1D\_FILTD procedure. Two input arrows labeled 'X\_ext' and 'i\_0, i\_1' enter a rectangular block labeled '1D\_FILTD'. An output arrow labeled 'Y' exits the block to the right. The reference T.812(07)\_F-F15 is shown to the right of the block. + +Figure F.15 – Parameters of the 1D\_FILTD procedure + +##### F.3.8.1 The 1D\_FILTD5-3R procedure + +The reversible transformation described in this subclause is the reversible lifting-based implementation of filtering by the 5-3 reversible wavelet filter. The reversible transformation is defined using lifting-based filtering. The odd-indexed coefficients of output signal $Y$ are computed first for all values of $n$ such that $\left\lceil \frac{i_0}{2} \right\rceil - 1 \leq n < \left\lceil \frac{i_1}{2} \right\rceil$ , as given in Equation (F-3): + +$$Y(2n+1) = X_{ext}(2n+1) - \left\lfloor \frac{X_{ext}(2n) + X_{ext}(2n+2)}{4} \right\rfloor \quad (F-3)$$ + +Then the even-indexed coefficients of output signal $Y$ are computed from the even-indexed values of extended signal $X_{ext}$ and the odd-indexed coefficients of signal $Y$ for all values of $n$ such that $\left\lceil \frac{i_0}{2} \right\rceil \leq n < \left\lceil \frac{i_1}{2} \right\rceil$ as given in Equation (F-4): + +$$Y(2n) = X_{ext}(2n) + \left\lfloor \frac{Y(2n-1) + Y(2n+1) + 2}{4} \right\rfloor \quad (F-4)$$ + +The values of $Y(k)$ such that $i_0 \leq k < i_1$ form the output of the 1D\_FILTD5-3R procedure (see Annex F in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004). + +##### F.3.8.2 The 1D\_FILTD9-7I procedure + +The irreversible transformation described in this subclause is the lifting-based DWT implementation of filtering by the 9-7 irreversible filter. + +Equation (F-5) describes the four lifting steps (1 through 4) and the two scaling steps (5 and 6) of the 1D filtering performed on the extended signal $X_{ext}(n)$ to produce the $i_1 - i_0$ coefficients of signal $Y$ . These steps are performed in the following order. + +Firstly, step 1 is performed for all values of $n$ such that $\left\lceil \frac{i_0}{2} \right\rceil - 2 \leq n < \left\lceil \frac{i_1}{2} \right\rceil + 1$ . + +Then, step 2 is performed for all values of $n$ such that $\left\lceil \frac{i_0}{2} \right\rceil - 1 \leq n < \left\lceil \frac{i_1}{2} \right\rceil + 1$ , and uses values calculated at step 1. + +Then, step 3 is performed for all values of $n$ such that $\left\lceil \frac{i_0}{2} \right\rceil - 1 \leq n < \left\lceil \frac{i_1}{2} \right\rceil$ , and uses values calculated at steps 1 and 2. + +Then, step 4 is performed for all values of $n$ such that $\left\lceil \frac{i_0}{2} \right\rceil \leq n < \left\lceil \frac{i_1}{2} \right\rceil$ , and uses values calculated at steps 2 and 3. + +Finally, step 5 is performed for all values of $n$ such that $\left\lceil \frac{i_0}{2} \right\rceil \leq n < \left\lceil \frac{i_1}{2} \right\rceil$ and uses values calculated at step 3, and step 6 + +is performed for all values of $n$ such that $\left\lceil \frac{i_0}{2} \right\rceil \leq n < \left\lceil \frac{i_1}{2} \right\rceil$ and uses values calculated at step 4. + +$$\left\{ \begin{array}{ll} Y(2n+1) = X_{ext}(2n+1) + \alpha(X_{ext}(2n) + X_{ext}(2n+2)) & [STEP1] \\ Y(2n) = X_{ext}(2n) + \beta(Y(2n-1) + Y(2n+1)) & [STEP2] \\ Y(2n+1) = Y(2n+1) + \gamma(Y(2n) + Y(2n+2)) & [STEP3] \\ Y(2n) = Y(2n) + \delta(Y(2n-1) + Y(2n+1)) & [STEP4] \\ Y(2n+1) = KY(2n+1) & [STEP5] \\ Y(2n) = (1/K)Y(2n) & [STEP6] \end{array} \right. \quad (F-5)$$ + +where the values of the lifting parameters $\alpha$ , $\beta$ , $\gamma$ , $\delta$ , and $K$ are defined in Table F.3. + +**Table F.3 – Definition of lifting parameters for the 9-7 irreversible filter** + +| Parameter | Exact expression | Approximate value | +|-----------|------------------|------------------------| +| $\alpha$ | $-g_4 / g_3$ | -1.586 134 342 059 924 | +| $\beta$ | $g_3 / r_1$ | -0.052 980 118 572 961 | +| $\gamma$ | $r_1 / s_0$ | 0.882 911 075 530 934 | +| $\delta$ | $s_0 / t_0$ | 0.443 506 852 043 971 | +| K | $1 / t_0$ | 1.230 174 104 914 001 | + +The values of $Y(k)$ such that $i_0 \leq k < i_1$ form the output of the 1D\_FILTD9-71 procedure (see Annex F in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004). + +### F.4 Sub-sampling of components + +It has become common practice in some compression applications to utilize component sub-sampling in conjunction with certain decorrelating transforms. A typical example is the use of an RGB to YCrCb decorrelation transformation followed by sub-sampling of the chrominance (Cr, Cb) components. While this is an effective way to reduce the amount of image data to encode for DCT-based compression algorithms (ITU-T Rec. T.81 | ISO/IEC 10918-1), it is not recommended for use in this Recommendation | International Standard. + +The multi-resolution nature of the wavelet transformation described in this Recommendation | International Standard may be used to achieve the same effect as that obtained from component sub-sampling. For example, if the 1HL, 1LH, and 1HH sub-bands of a component's wavelet decomposition are discarded and all other sub-bands retained, a 2:1 sub-sampling has been achieved in the horizontal and vertical dimensions of the component. This technique provides the same benefits as explicitly sub-sampling the component prior to any wavelet transform. + +Furthermore, it frequently proves to be beneficial in terms of image quality to retain a few of the wavelet coefficients in the 1HL, 1LH, and 1HH sub-bands, while still discarding the vast majority. In such cases the number of coefficients is still approximately reduced 2:1, but the resultant decoded imagery will exhibit better quality with fewer compression artifacts. Using a sub-sampling technique denies encoders from making such choices and can impair decoded image quality. + +NOTE – Annex F.4 is identical to J.13 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004. + +### F.5 Visual frequency weighting + +The human visual system plays an important role in the perceived image quality of compressed images. It is therefore desirable to allow system designers and users to take advantage of the current knowledge of visual perception, e.g., to utilize models of the visual system's varying sensitivity to spatial frequencies, as measured in the contrast sensitivity function (CSF). Since the CSF weight is determined by the visual frequency of the transformation coefficient, there will be one CSF weight per sub-band in the wavelet transform. The design of the CSF weights is an encoder issue and depends on the specific viewing condition under which the decoded image is to be viewed. + +In many cases, only one set of CSF weights is chosen and applied according to the viewing condition. This application of visual frequency weighting is referred to as fixed visual weighting. In the case of embedded coders, as the coding bit stream may be truncated later, the viewing conditions at different stages of embedding may be very different. At low bit rates, the quality of the compressed image is poor and the detailed features of the image are not available. The image is usually viewed at a relatively large distance and the observers are more interested in the global features. As more and more bits are received, the image quality improves, and the details of the image are revealed. The image is usually examined at a closer distance, or is even magnified for close examination, which is equivalent to decreasing the viewing distance. Thus, different sets of CSF weights are called for at different stages of the embedding. This adjustable application of visual frequency weighting is referred to as visual progressive coding. It is clear that fixed visual weighting can be viewed as a special case of visual progressive coding. + +In fixed visual weighting, a set of CSF weights, $\{w_i\}$ , is chosen according to the final viewing condition, where $w_i$ is the weight for the $i$ th sub-band. The set of CSF weights can be incorporated in one of the following two ways. + +#### F.5.1 Modify quantization step size + +At the encoder, the quantization step size $q_i$ of the transformation coefficients of the $i$ th sub-band is adjusted to be inversely proportional to the CSF weight $w_i$ . The smaller the CSF weight, the larger the quantization step size. The CSF-normalized quantization indices are then treated uniformly in the R-D optimization process, which is not modified to take into account any changes in the quantization step size. The CSF weights do not need to be transmitted to the decoder. The information is included in the quantization step sizes, which are explicitly transmitted for each sub-band. + +This approach needs to explicitly specify the quantizer. Therefore, it may not be very suitable for embedded coding, especially for embedded coding from lossy all the way to lossless. + +#### F.5.2 Modify the embedded coding order + +The quantization step sizes are not modified but the distortion weights fed into the R-D optimization are altered instead. This effectively controls the relative significance of including different numbers of bit-planes from the embedded bit stream of each code-block. The frequency-weighting table does not need to be transmitted explicitly. This approach is recommended since it produces similar results in F.5.1 and is compatible with lossless compression. This approach affects only the compressor and it is compatible with all quantization strategies, including implicit quantization. + +#### F.5.3 Visual progressive coding (VIP) + +If the visual frequency weights are to be changed during the embedded coding process, it is very clumsy to change the coefficient values or quantization step sizes. Furthermore, the performance of the subsequent entropy coder may degrade due to the changing statistics of the binary representation. An elegant way to implement the visual progressive coding (VIP) is to change, on the fly, the order in which code-block sub-bit-planes should appear in the overall embedded bit stream based on the visual weights, instead of changing the coefficient values or quantization step sizes. In other words, the coding order rather than the coding content is affected by the visual weights. + +A series of visual weighting sets for different bit rate ranges are denoted as follows: + +$$\begin{aligned} \text{Weighting set 0 : } r(0), \text{ with } W(0) &= \{w_0(0), w_1(0), \dots, w_n(0)\}; \\ \text{Weighting set 1 : } r(1), \text{ with } W(1) &= \{w_0(1), w_1(1), \dots, w_n(1)\}; \\ &\dots \\ \text{Weighting set } m : r(m), \text{ with } W(m) &= \{w_0(m), w_1(m), \dots, w_n(m)\}, \end{aligned} \tag{F-6}$$ + +where $r(j)$ represents a bit-rate at which the weighting factors are changed, $r(0) < r(1) < \dots < r(m)$ , and $w_i(j)$ is the weight applied to sub-band $i$ over the bit rate range from $r(j)$ to $r(j+1)$ . Each set of visual weights will take effect within a certain bit rate range. If $m=0$ , i.e., there is only one set of visual weights, it degenerates to the fixed visual weighting case. The sets of visual weights, $W(0)$ to $W(m)$ , will be used to determine the embedding order in their corresponding bit rate ranges. For high bit rate embedding, especially embedded coding from lossy all the way to lossless, the final visual weights $W(m)$ need to be all ones (as no weighting for lossless coding). Visual progressive coding can adjust the visual weights to achieve good visual quality for all bit rates. + +The VIP weighting affects only the encoder and no signalling is required at the decoder. + +The encoder is expected to compute the order in which code-block sub-bit-planes should appear in the layered hierarchy of the overall bit stream, based upon rate-distortion criteria. A simple implementation of progressive visual weighting changes the distortion metric progressively based on the visual weights during bit stream formation. Since bit stream formation is driven by post-compression R-D optimization, progressively changing visual weights effectively controls the embedding order of code-block sub-bit-planes on the fly. + +#### F.5.4 Recommended frequency weighting tables + +Table F.4 specifies three sets of CSF weights which were designed for the luminance component based on the CSF value at the mid-frequency of each sub-band. The viewing distance is supposed to be 1000, 2000, and 4000 samples (e.g., corresponding to 10 inches for 100 dpi, 200 dpi, and 400 dpi print or display), respectively. Note that the tables are intended for a 5-level wavelet decomposition. + +Table F.4 does not include the weight for the lowest frequency sub-band, nLL, which is always 1. Levels 1, 2, ..., 5 denote the sub-band levels in low to high frequency order. (HL, LH, HH) denotes the three frequency orientations within each sub-band. + +Table F.4 – Recommended frequency weighting + +| Level | Viewing distance 1000 | | | Viewing distance 2000 | | | Viewing distance 4000 | | | +|-------|-----------------------|----------|----------|-----------------------|----------|----------|-----------------------|----------|----------| +| | HL | LH | HH | HL | LH | HH | HL | LH | HH | +| 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | +| 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0.731668 | +| 3 | 1 | 1 | 1 | 1 | 1 | 0.727203 | 0.564344 | 0.564344 | 0.285968 | +| 4 | 1 | 1 | 0.727172 | 0.560841 | 0.560841 | 0.284193 | 0.179609 | 0.179609 | 0.043903 | +| 5 | 0.560805 | 0.560805 | 0.284173 | 0.178494 | 0.178494 | 0.043631 | 0.014774 | 0.014774 | 0.000573 | + +For colour images, the frequency weighting tables of the Y, Cr, and Cb components should differ in order to take advantage of the properties of the human visual system. For example, it is usually desirable to emphasize the luminance component more than the chrominance components. Table F.5 specifies three sets of CSF weights for luminance and chrominance components. + +Table F.5 – Recommended frequency weighting for multiple component (colour) images + +| Component | Level | Viewing distance 1000 | | | Viewing distance 1700 | | | Viewing distance 3000 | | | +|------------|-------|-----------------------|----------|----------|-----------------------|----------|----------|-----------------------|----------|----------| +| | | HL | LH | HH | HL | LH | HH | HL | LH | HH | +| Y
(Y0) | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | +| | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | +| | 3 | 1 | 1 | 1 | 1 | 1 | 1 | 0.921045 | 0.921045 | 0.848324 | +| | 4 | 0.998276 | 0.998276 | 0.996555 | 0.861593 | 0.861593 | 0.742342 | 0.410628 | 0.410628 | 0.182760 | +| | 5 | 0.756353 | 0.756353 | 0.573057 | 0.307191 | 0.307191 | 0.108920 | 0.038487 | 0.038487 | 0.003075 | +| Cb
(Y1) | 1 | 0.883196 | 0.883196 | 0.833582 | 0.818766 | 0.818766 | 0.745875 | 0.717086 | 0.717086 | 0.613777 | +| | 2 | 0.793487 | 0.793487 | 0.712295 | 0.689404 | 0.689404 | 0.579220 | 0.539437 | 0.539437 | 0.403353 | +| | 3 | 0.650482 | 0.650482 | 0.531700 | 0.501652 | 0.501652 | 0.362279 | 0.319773 | 0.319773 | 0.185609 | +| | 4 | 0.450739 | 0.450739 | 0.309177 | 0.280068 | 0.280068 | 0.152290 | 0.124021 | 0.124021 | 0.044711 | +| | 5 | 0.230503 | 0.230503 | 0.113786 | 0.097816 | 0.097816 | 0.031179 | 0.023308 | 0.023308 | 0.003413 | +| Cr
(Y2) | 1 | 0.910877 | 0.910877 | 0.872378 | 0.860885 | 0.860885 | 0.803172 | 0.780091 | 0.780091 | 0.695128 | +| | 2 | 0.841032 | 0.841032 | 0.776180 | 0.757626 | 0.757626 | 0.665951 | 0.631632 | 0.631632 | 0.509729 | +| | 3 | 0.725657 | 0.725657 | 0.625103 | 0.598537 | 0.598537 | 0.470893 | 0.428659 | 0.428659 | 0.287593 | +| | 4 | 0.552901 | 0.552901 | 0.418938 | 0.388492 | 0.388492 | 0.248566 | 0.211871 | 0.211871 | 0.100658 | +| | 5 | 0.336166 | 0.336166 | 0.200507 | 0.177435 | 0.177435 | 0.077130 | 0.060277 | 0.060277 | 0.014977 | + +## Annex G + +### DC level shifting and multiple component transformations + +(This annex forms an integral part of this Recommendation | International Standard) + +In this annex, the flow charts and tables are normative only in the sense that they are defining an output that alternative implementations shall duplicate. + +This annex specifies DC level shifting that converts the source proper source samples into the signed values. + +This annex also describes two different multiple component transformations. These multiple component transformations are used to improve compression efficiency. They are not related to multiple component transformations used to map colour values for display purposes. One multiple component transformation is reversible and may be used for lossy or lossless coding. The other is irreversible and may only be used for lossy coding. + +### G.1 DC level shifting of tile-components + +Figure G.1 shows the flow of DC level shifting in the system with a multiple component transformation. + +![Flowchart showing the placement of DC level shifting with component transformation. The flow is: sample -> Forward DC level shift -> Forward component transformation -> Forward wavelet transformation -> coding -> Inverse wavelet transformation -> Inverse component transformation -> Inverse DC level shift -> reconstructed sample.](9e4f582a5d5f6742d1372956db0f8f0b_img.jpg) + +``` + +graph LR + sample --> FDC[Forward DC level shift] + FDC --> FCT[Forward component transformation] + FCT --> FWT[Forward wavelet transformation] + FWT -- coding --> IWT[Inverse wavelet transformation] + IWT --> ICT[Inverse component transformation] + ICT --> IDC[Inverse DC level shift] + IDC --> reconstructed_sample[reconstructed sample] + +``` + +T.812(07)\_F-G1 + +Flowchart showing the placement of DC level shifting with component transformation. The flow is: sample -> Forward DC level shift -> Forward component transformation -> Forward wavelet transformation -> coding -> Inverse wavelet transformation -> Inverse component transformation -> Inverse DC level shift -> reconstructed sample. + +**Figure G.1 – Placement of the DC level shifting with component transformation** + +Figure G.2 shows the flow of DC level shifting in the system without a multiple component transformation. + +![Flowchart showing the placement of DC level shifting without component transformation. The flow is: sample -> Forward DC level shift -> Forward wavelet transformation -> coding -> Inverse wavelet transformation -> Inverse DC level shift -> reconstructed sample.](86692d82da6655813b5acf58a767a38c_img.jpg) + +``` + +graph LR + sample --> FDC[Forward DC level shift] + FDC --> FWT[Forward wavelet transformation] + FWT -- coding --> IWT[Inverse wavelet transformation] + IWT --> IDC[Inverse DC level shift] + IDC --> reconstructed_sample[reconstructed sample] + +``` + +T.812(07)\_F-G2 + +Flowchart showing the placement of DC level shifting without component transformation. The flow is: sample -> Forward DC level shift -> Forward wavelet transformation -> coding -> Inverse wavelet transformation -> Inverse DC level shift -> reconstructed sample. + +**Figure G.2 – Placement of the DC level shifting without component transformation** + +#### G.1.1 DC level shifting of tile-components + +DC level shifting is performed on samples of components that are unsigned only. It is performed prior to computation of a forward multiple component transformation (RCT or ICT), if one is used. Otherwise, it is performed prior to the wavelet transformation described in Annex F. If the MSB of $Ssiz^i$ from the SIZ marker segment (see A.5.1 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004) is zero, all samples $I(x, y)$ of the $i$ th component are level shifted by subtracting the same quantity from each sample as follows: + +$$I(x, y) \leftarrow I(x, y) - 2^{Ssiz^i} \quad (G-1)$$ + +### G.2 Forward reversible multiple component transformation (RCT) + +The use of the reversible multiple component transformation is signalled in the COD marker segment (see A.6.1 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004). The RCT shall be used only with the 5-3 reversible filter. The RCT is a decorrelating transformation applied to the first three components of an image (indexed as 0, 1 and 2). The three components input into the RCT shall have the same separation on the reference grid and the same bit-depth. + +NOTE – While the RCT is reversible, and thus capable of lossless compression, it may be used in truncated codestream to provide lossy compression. + +Prior to applying the Forward RCT, the image component samples are DC level shifted, for unsigned components. + +The Forward RCT is applied to components $I_0(x, y)$ , $I_1(x, y)$ , $I_2(x, y)$ as follows: + +$$Y_0(x, y) = \left\lfloor \frac{I_0(x, y) + 2I_1(x, y) + I_2(x, y)}{4} \right\rfloor \quad (\text{G-2})$$ + +$$Y_1(x, y) = I_2(x, y) - I_1(x, y) \quad (\text{G-3})$$ + +$$Y_2(x, y) = I_0(x, y) - I_1(x, y) \quad (\text{G-4})$$ + +If $I_0$ , $I_1$ and $I_2$ are normalized to the same precision, then Equations (G-3) and (G-4) result in a numeric precision of $Y_1$ and $Y_2$ that is one bit greater than the precision of the original components. This increase in precision is necessary to ensure reversibility. + +### G.3 Forward irreversible multiple component transformation (ICT) + +This subclause specifies an irreversible multiple component transformation. The use of the irreversible component transformation is signalled in the COD marker segment (see A.6.1 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004). The ICT shall be used only with the 9-7 irreversible filter. The ICT is a decorrelating transformation applied to the first three components of an image (indexed as 0, 1 and 2). The three components input into the ICT shall have the same separation on the reference grid and the same bit-depth. + +The Forward ICT is applied to image component samples $I_0(x, y)$ , $I_1(x, y)$ , $I_2(x, y)$ , as follows: + +$$Y_0(x, y) = -0.299 I_0(x, y) - 0.587 I_1(x, y) + 0.114 I_2(x, y) \quad (\text{G-5})$$ + +$$Y_1(x, y) = -0.16875 I_0(x, y) - 0.331260 I_1(x, y) + 0.5 I_2(x, y) \quad (\text{G-6})$$ + +$$Y_2(x, y) = 0.5 I_0(x, y) - 0.41869 I_1(x, y) - 0.08131 I_2(x, y) \quad (\text{G-7})$$ + +NOTE – If the first three components are Red, Green and Blue components, then the Forward ICT is of a YCbCr transformation. + +### G.4 Chrominance component sub-sampling and the reference grid + +The relationship between the components and the reference grid is signalled in the SIZ marker (see Annex A.5.1 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004) and described in Annex B.2 in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004. + +## Annex H + +## Coding of images with regions of interest + +(This annex forms an integral part of this Recommendation | International Standard) + +In this annex and all of its subclauses, the flow charts and tables are normative only in the sense that they are defining an output that alternative implementations shall duplicate. + +This annex describes the region of interest (ROI) technology. An ROI is a part of an image that is coded earlier in the codestream than the rest of the image (the background). The coding is also done in such a way that the information associated with the ROI precedes the information associated with the background. The method used (and described in this annex) is the Maxshift method. + +### H.1 Description of the Maxshift method + +#### H.1.1 Encoding of ROI + +The encoding of the quantized transform coefficients is done in a similar way to encoding without any ROIs. At the encoder side, an ROI mask is created describing which quantized transform coefficients must be encoded with better quality (even up to losslessly) in order to encode the ROI with better quality (up to lossless). The ROI mask is a bit map describing these coefficients. See H.2 for details on how the mask is generated. + +The quantized transform coefficients outside of the ROI mask, called background coefficients, are scaled down so that the bits associated with the ROI are placed in higher bit-planes than the background. This means that when the entropy coder encodes the quantized transform coefficients, the bit-planes associated with the ROI are coded before the information associated with the background. + +The method can be described using the following steps: + +- 1) Generate ROI mask, $M(x, y)$ (see H.2). +- 2) Find the scaling value $s$ (see H.1.2). +- 3) Add $s$ LSBs to each coefficient $|q_b(u, v)|$ . The number $M'_b$ of magnitude bit-planes will then be: + +$$M'_b = M_b + s \quad (\text{H-1})$$ + +where $M_b$ is given by Equation (E-2) and the new value of each coefficient is given by: + +$$|q_b(u, v)| = |q_b(u, v)| \cdot 2^s \quad (\text{H-2})$$ + +- 4) Scale down all background coefficients given by $M(x, y)$ using the scaling value $s$ (see H.1.2). Thus, if $|q_b(u, v)|$ is a background coefficient given by $M(x, y)$ , then: + +$$|q_b(u, v)| = \frac{|q_b(u, v)|}{2^s} \quad (\text{H-3})$$ + +- 5) Write the scaling value $s$ into the codestream using the SPrgn parameter of the RGN marker segment. + +After these steps, the quantized transform coefficients are entropy coded as usual. + +#### H.1.2 Selection of scaling value, $s$ , at encoder side + +The scaling value, $s$ , may be chosen so that Equation (H-4) holds, where $\max(M_b)$ is the largest number of magnitude bit-planes, see Equation (E-1), for any background coefficient, $q_{BG}(x, y)$ in any code-block in the current component. + +$$s \geq \max(M_b) \quad (\text{H-4})$$ + +This guarantees that the scaling value used will be sufficiently large to ensure all the significant bits associated with the ROI will be in higher bit-planes than all the significant bits associated with the background. + +### H.2 Remarks on region of interest coding + +The ROI functionality described in H.1 depends only on the scaling value chosen on the encoder side and hence only on the amplitude of the coefficients on the decoder side. It is up to the encoder to generate a mask that corresponds to the coefficients that need to be encoded with better quality to yield an ROI with better quality than the background. Subclause H.2.1 describes how to generate the ROI mask for a particular region in the image. Subclause H.2.2 describes how to generate the mask in the case of multi-component images and H.2.3 describes how to generate the ROI mask for disjoint regions. + +#### H.2.1 Region of interest mask generation + +To achieve an ROI with better quality than the rest of the image while maintaining a fair amount of compression, bits need to be saved by sending less information for the background. To do this, an ROI mask is calculated. The mask is a bit-plane indicating a set of quantized transform coefficients whose coding is sufficient in order for the receiver to reconstruct the desired region with better quality than the background (up to lossless). + +To illustrate the concept of ROI mask generation, let us restrict ourselves to a single ROI and a single image component, and identify the samples that belong to the ROI in the image domain by a binary mask, $M(x, y)$ , where: + +$$M(x, y) = \begin{cases} 1 & \text{wavelet coefficient } (x, y) \text{ is needed} \\ 0 & \text{accuracy on } (x, y) \text{ can be sacrificed without affecting ROI} \end{cases} \quad (\text{H-5})$$ + +The mask is a map of the ROI in the wavelet domain so that it has a non-zero value inside the ROI and 0 outside. In each step, the LL sub-band of the mask is then updated row by row and then column by column. The mask will then indicate which coefficients are needed at this step so that the inverse wavelet transformation will reproduce the coefficients of the previous mask. + +For example, the last step of the inverse wavelet transformation is a composition of two sub-bands into one. Then to trace this step backwards, one finds the coefficients of both sub-bands that are needed. The step before that is a composition of four sub-bands into two. To trace this step backwards, the coefficients in the four sub-bands that are needed to give a perfect reconstruction of the coefficients included in the mask for two sub-bands are found. + +All steps are then traced backwards to give the mask. If the coefficients corresponding to the mask are transmitted and received, and the inverse wavelet transformation calculated on them, the desired ROI will be reconstructed with better quality than the rest of the image (up to lossless if the ROI coefficients were coded losslessly). + +Given below is a description of how the expansion of the mask is acquired from the various filters. Similar methods can be used for other filters. + +##### H.2.1.1 Region of interest mask generation using the 5-3 reversible filter + +In order to get the optimal set of quantized coefficients to be scaled, the following equations described in this subclause should be used. + +To see what coefficients need to be in the mask, the inverse wavelet transformation is studied. Equations (F-5) and (F-6) in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004 give the coefficients needed to reconstruct $X(2n)$ and $X(2n+1)$ losslessly. It can immediately be seen that these are $L(n)$ , $L(n+1)$ , $H(n-1)$ , $H(n)$ , $H(n+1)$ (see Figure H.1). Hence if $X(2n)$ and $X(2n+1)$ are in the ROI, the listed low and high sub-band coefficients are in the mask. Notice that $X(2n)$ and $X(2n+1)$ are even and odd indexed points respectively, relative to the origin of the reference grid. + +![Diagram illustrating the inverse wavelet transformation with the 5-3 reversible filter. It shows two input sub-bands, 'Low' and 'High', each with three coefficients: n-1, n, and n+1. These are combined to produce two output coefficients, 2n and 2n+1, in the 'X:s' sub-band. Lines connect the input coefficients to the output coefficients, showing the reconstruction process.](e9f5aa7b76362051c591d6783211f820_img.jpg) + +The diagram shows two input sub-bands, 'Low' and 'High', each with three coefficients: $n-1$ , $n$ , and $n+1$ . These are combined to produce two output coefficients, $2n$ and $2n+1$ , in the 'X:s' sub-band. Lines connect the input coefficients to the output coefficients, showing the reconstruction process. + +Diagram illustrating the inverse wavelet transformation with the 5-3 reversible filter. It shows two input sub-bands, 'Low' and 'High', each with three coefficients: n-1, n, and n+1. These are combined to produce two output coefficients, 2n and 2n+1, in the 'X:s' sub-band. Lines connect the input coefficients to the output coefficients, showing the reconstruction process. + +Figure H.1 – The inverse wavelet transformation with the 5-3 reversible filter + +##### H.2.1.2 Region of interest mask generation using the 9-7 irreversible filter + +Successful decoding does not depend upon the selection of samples to be scaled. In order to get the optimal set of quantized coefficients to be scaled, the following equations described in this subclause should be used. + +To see what coefficients need to be in the mask, the inverse wavelet transformation is studied as in H.2.1.1. Figure H.2 shows this $X(2n)$ and $X(2n + 1)$ are even and odd indexed points respectively, related to the origin of the reference grid. + +![Diagram illustrating the inverse wavelet transformation with the 9-7 irreversible filter. It shows three horizontal arrays of boxes. The top-left array, labeled 'Low', contains boxes indexed n-2, n-1, n, n+1, n+2. The top-right array, labeled 'High', contains boxes indexed n-3, n-2, n-1, n, n+1, n+2, n+3. The bottom array, labeled 'X:s', contains boxes indexed 2n and 2n+1. Lines connect the 'Low' array to the 'X:s' array: n-2 to 2n, n-1 to 2n, n to 2n+1, n+1 to 2n+1, and n+2 to 2n+1. Lines connect the 'High' array to the 'X:s' array: n-3 to 2n, n-2 to 2n, n-1 to 2n, n to 2n+1, n+1 to 2n+1, n+2 to 2n+1, and n+3 to 2n+1.](3c99312f83459559d9a301148555d7b9_img.jpg) + +Diagram illustrating the inverse wavelet transformation with the 9-7 irreversible filter. It shows three horizontal arrays of boxes. The top-left array, labeled 'Low', contains boxes indexed n-2, n-1, n, n+1, n+2. The top-right array, labeled 'High', contains boxes indexed n-3, n-2, n-1, n, n+1, n+2, n+3. The bottom array, labeled 'X:s', contains boxes indexed 2n and 2n+1. Lines connect the 'Low' array to the 'X:s' array: n-2 to 2n, n-1 to 2n, n to 2n+1, n+1 to 2n+1, and n+2 to 2n+1. Lines connect the 'High' array to the 'X:s' array: n-3 to 2n, n-2 to 2n, n-1 to 2n, n to 2n+1, n+1 to 2n+1, n+2 to 2n+1, and n+3 to 2n+1. + +T.812(07)\_F-H2 + +**Figure H.2 – The inverse wavelet transformation with the 9-7 irreversible filter** + +The coefficients needed to reconstruct $X(2n)$ and $X(2n + 1)$ losslessly can immediately be seen to be $L(n - 1)$ to $L(n + 2)$ and $H(n - 2)$ to $H(n + 2)$ . Hence if $X(2n)$ and $X(2n + 1)$ are in the ROI, those Low and High sub-band coefficients are in the mask. + +#### H.2.2 Multi-component remark + +For the case of colour images, the method applies separately in each colour component. If some of the colour components are down-sampled, the mask for the down-sampled components is created in the same way as the mask for the non-down-sampled components. + +#### H.2.3 Disjoint regions remark + +If the ROI consists of disjoint parts, then all parts have the same scaling value $s$ . + +## **Annex I** + +### **JP2 file format syntax** + +(This annex forms an integral part of this Recommendation | International Standard. +This annex is optional for the entry level encoder) + +There is no additional file format syntax of JP2 file format. + +This annex is identical to Annex I in ITU-T Rec. T.800 | ISO/IEC 15444-1:2004. + + + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|---------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.832-201906-I_PDF-E/raw.md b/marked/T/T-REC-T.832-201906-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..93b503b8e501d95cc67aedd616a247f16b2f5077 --- /dev/null +++ b/marked/T/T-REC-T.832-201906-I_PDF-E/raw.md @@ -0,0 +1,10890 @@ + + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# T.832 + +(06/2019) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES + +Still-image compression | JPEG XR + +# --- Information technology – JPEG XR image coding system – Image coding specification + +Recommendation   ITU-T   T.832 + +## ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES** + +| | | +|-----------------------------------------------------|--------------------| +| Facsimile – Framework | T.0–T.19 | +| Still-image compression – Test charts | T.20–T.29 | +| Facsimile – Group 3 protocols | T.30–T.39 | +| Colour representation | T.40–T.49 | +| Character coding | T.50–T.59 | +| Facsimile – Group 4 protocols | T.60–T.69 | +| Telematic services – Framework | T.70–T.79 | +| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89 | +| Telematic services – ISDN Terminals and protocols | T.90–T.99 | +| Videotext – Framework | T.100–T.109 | +| Data protocols for multimedia conferencing | T.120–T.149 | +| Telewriting | T.150–T.159 | +| Multimedia and hypermedia framework | T.170–T.189 | +| Cooperative document handling | T.190–T.199 | +| Telematic services – Interworking | T.300–T.399 | +| Open document architecture | T.400–T.429 | +| Document transfer and manipulation | T.430–T.449 | +| Document application profile | T.500–T.509 | +| Communication application profile | T.510–T.559 | +| Telematic services – Equipment characteristics | T.560–T.619 | +| General multimedia application frameworks | T.620–T.649 | +| Still-image compression – JPEG 2000 | T.800–T.829 | +| Still-image compression JPEG XR | T.830–T.849 | +| Still-image compression – JPEG-1 extensions | T.850–T.899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# Information technology – JPEG XR image coding system – Image coding specification + +# Summary + +Recommendation ITU-T T.832 specifies a coded image format, referred to as JPEG XR, which is designed primarily for the storage and interchange of continuous-tone photographic content. The main body of the text specifies the syntax and semantics of JPEG XR coded images and the associated decoding process. Annex A specifies a tag-based file storage format for the storage and interchange of such coded images. Annex B specifies profiles and levels that determine conformance requirements for classes of encoders and decoders. Aspects of colour imagery representations and colour management are discussed in Annex C. The typical expected encoding process is described in Annex D. + +The first edition of Recommendation ITU-T T.832 was approved in 03/2009. + +Corrigendum 1 (approved 12/2009) contained a set of various minor corrections. + +Corrigendum 2 (approved 05/2011) contained additional minor corrections. + +The second edition (approved 01/2012) included additional minor corrections. + +The third edition (approved 08/2016) added a media type specification for use in various Internet protocols to identify images encoded according to the tag-based format specified in Annex A of this Recommendation. + +This fourth edition (approved 06/2019) adds the specification of support for additional colour formats, support for an alternative file storage format based on ISO/IEC 23008-12 and associated media type specifications for the storage and interchange of JPEG XR coded images and image sequences. + +This text was developed as a twin text Recommendation corresponding to ISO/IEC 29199-2 in collaboration with ISO/IEC JTC 1/SC 29/WG 1 (JPEG). + +# History + +| Edition | Recommendation | Approval | Study Group | Unique ID* | +|---------|---------------------------|------------|-------------|---------------------------------------------------------------------------| +| 1.0 | ITU-T T.832 | 2009-03-16 | 16 | 11.1002/1000/9721 | +| 1.1 | ITU-T T.832 (2009) Cor.1 | 2009-12-14 | 16 | 11.1002/1000/10647 | +| 1.2 | ITU-T T.832 (2009) Cor. 2 | 2011-05-14 | 16 | 11.1002/1000/11317 | +| 2.0 | ITU-T T.832 | 2012-01-13 | 16 | 11.1002/1000/11471 | +| 3.0 | ITU-T T.832 | 2016-08-13 | 16 | 11.1002/1000/12959 | +| 4.0 | ITU-T T.832 (V4) | 2019-06-28 | 16 | 11.1002/1000/13914 | + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. For example, . + +# FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +# INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2019 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +# Table of Contents + +| | Page | +|-------------------------------------------------------------------------|------| +| 1 Scope ..... | 1 | +| 2 Normative references..... | 1 | +| 3 Definitions ..... | 1 | +| 4 Abbreviations ..... | 4 | +| 5 Conventions..... | 5 | +| 5.1 Conformance language..... | 5 | +| 5.2 Operators..... | 5 | +| 5.2.1 Arithmetic operators..... | 5 | +| 5.2.2 Logical operators..... | 6 | +| 5.2.3 Relational operators..... | 6 | +| 5.2.4 Bit-wise operators ..... | 6 | +| 5.2.5 Assignment operators..... | 7 | +| 5.2.6 Precedence order of operators ..... | 7 | +| 5.2.7 Pseudocode operations ..... | 8 | +| 5.2.8 Mathematical functions ..... | 9 | +| 5.3 Syntax and semantics notation ..... | 12 | +| 5.3.1 Method of specifying syntax in tabular form ..... | 12 | +| 5.3.2 SYNTAX_ELEMENT_EXAMPLE semantics..... | 13 | +| 5.3.3 Syntax functions..... | 13 | +| 5.4 Formatting conventions..... | 13 | +| 5.4.1 Variable and array naming conventions ..... | 13 | +| 5.4.2 Data structure naming conventions ..... | 14 | +| 5.4.3 Syntax element naming conventions ..... | 14 | +| 5.4.4 Syntax structure naming conventions..... | 14 | +| 5.4.5 Naming conventions for mnemonic constants..... | 14 | +| 5.4.6 Naming conventions for numerical values ..... | 14 | +| 5.4.7 Array dimensions convention..... | 14 | +| 5.5 Global variables ..... | 15 | +| 5.5.1 Image variables ..... | 15 | +| 5.5.2 Image plane variables..... | 15 | +| 5.5.3 Tile variables..... | 16 | +| 5.5.4 Macroblock variables ..... | 16 | +| 5.5.5 Data structures for adaptive VLC table selection ..... | 17 | +| 5.5.6 Adaptive coefficient normalization data structure instances ..... | 19 | +| 5.5.7 Adaptive CBPHP prediction data structure instance ..... | 19 | +| 5.5.8 Adaptive count CBPLP variables..... | 20 | +| 5.6 Adaptive VLC deltaDisc tables ..... | 20 | +| 5.7 Adaptive inverse scanning tables ..... | 20 | +| 6 Image and codestream structures..... | 20 | +| 6.1 General ..... | 20 | +| 6.2 Image planes and component arrays ..... | 21 | +| 6.3 Image windowing..... | 21 | +| 6.4 Image partitioning ..... | 21 | +| 6.5 Transform coefficients and frequency bands ..... | 22 | +| 6.6 Codestream structure..... | 23 | +| 6.7 Precision and word length ..... | 24 | + +| | | | +|--------|-------------------------------------------------------|----| +| 7 | Overview of decoder ..... | 24 | +| 7.1 | General ..... | 24 | +| 7.2 | Overview of parsing process ..... | 25 | +| 7.2.1 | Overview of image layer codestream parsing ..... | 25 | +| 7.2.2 | Overview of tile layer codestream parsing ..... | 25 | +| 7.2.3 | Overview of macroblock layer codestream parsing ..... | 25 | +| 7.3 | Overview of the decoding process ..... | 26 | +| 7.3.1 | Overview of coefficient mapping ..... | 26 | +| 7.3.2 | Overview of coefficient prediction ..... | 26 | +| 7.3.3 | Overview of dequantization ..... | 26 | +| 7.3.4 | Overview of sample reconstruction ..... | 26 | +| 7.3.5 | Overview of output formatting ..... | 27 | +| 8 | Syntax, semantics, and parsing process ..... | 27 | +| 8.1 | General ..... | 27 | +| 8.2 | CODED_IMAGE( ) ..... | 28 | +| 8.2.1 | Syntax structure ..... | 28 | +| 8.2.2 | SubsequentBytes ..... | 28 | +| 8.2.3 | RESERVED_A_BYTE ..... | 28 | +| 8.2.4 | VLW_ESC( ) ..... | 29 | +| 8.3 | IMAGE_HEADER( ) ..... | 30 | +| 8.3.1 | Syntax structure ..... | 30 | +| 8.3.2 | GDI_SIGNATURE ..... | 30 | +| 8.3.3 | RESERVED_B ..... | 31 | +| 8.3.4 | HARD_TILING_FLAG ..... | 31 | +| 8.3.5 | RESERVED_C ..... | 31 | +| 8.3.6 | TILING_FLAG ..... | 31 | +| 8.3.7 | FREQUENCY_MODE_CODESTREAM_FLAG ..... | 31 | +| 8.3.8 | SPATIAL_XFRM_SUBORDINATE ..... | 31 | +| 8.3.9 | INDEX_TABLE_PRESENT_FLAG ..... | 32 | +| 8.3.10 | OVERLAP_MODE ..... | 32 | +| 8.3.11 | SHORT_HEADER_FLAG ..... | 32 | +| 8.3.12 | LONG_WORD_FLAG ..... | 32 | +| 8.3.13 | WINDOWING_FLAG ..... | 33 | +| 8.3.14 | TRIM_FLEXBITS_FLAG ..... | 33 | +| 8.3.15 | RESERVED_D ..... | 33 | +| 8.3.16 | RED_BLUE_NOT_SWAPPED_FLAG ..... | 33 | +| 8.3.17 | PREMULTIPLIED_ALPHA_FLAG ..... | 33 | +| 8.3.18 | ALPHA_IMAGE_PLANE_FLAG ..... | 34 | +| 8.3.19 | OUTPUT_CLR_FMT ..... | 34 | +| 8.3.20 | OUTPUT_BITDEPTH ..... | 35 | +| 8.3.21 | WIDTH_MINUS1 ..... | 35 | +| 8.3.22 | HEIGHT_MINUS1 ..... | 35 | +| 8.3.23 | NUM_VER_TILES_MINUS1 ..... | 36 | +| 8.3.24 | NUM_HOR_TILES_MINUS1 ..... | 36 | +| 8.3.25 | TILE_WIDTH_IN_MB[n] ..... | 36 | +| 8.3.26 | TILE_HEIGHT_IN_MB[n] ..... | 36 | +| 8.3.27 | TOP_MARGIN ..... | 37 | +| 8.3.28 | LEFT_MARGIN ..... | 37 | +| 8.3.29 | BOTTOM_MARGIN ..... | 37 | +| 8.3.30 | RIGHT_MARGIN ..... | 37 | +| 8.4 | IMAGE_PLANE_HEADER( ) ..... | 37 | +| 8.4.1 | Syntax structure ..... | 37 | +| 8.4.2 | INTERNAL_CLR_FMT ..... | 38 | +| 8.4.3 | SCALED_FLAG ..... | 39 | +| 8.4.4 | BANDS_PRESENT ..... | 39 | +| 8.4.5 | RESERVED_E_BIT ..... | 40 | +| 8.4.6 | CHROMA_CENTERING_X ..... | 40 | +| 8.4.7 | RESERVED_F ..... | 40 | + +| | | | +|--------|---------------------------------------------------|----| +| 8.4.8 | RESERVED_G_BIT ..... | 40 | +| 8.4.9 | CHROMA_CENTERING_Y ..... | 40 | +| 8.4.10 | RESERVED_H ..... | 41 | +| 8.4.11 | NUM_COMPONENTS_MINUS1 ..... | 41 | +| 8.4.12 | NUM_COMPONENTS_EXTENDED_MINUS16 ..... | 41 | +| 8.4.13 | SHIFT_BITS ..... | 41 | +| 8.4.14 | LEN_MANTISSA ..... | 41 | +| 8.4.15 | EXP_BIAS ..... | 41 | +| 8.4.16 | DC_IMAGE_PLANE_UNIFORM_FLAG ..... | 41 | +| 8.4.17 | RESERVED_I_BIT ..... | 42 | +| 8.4.18 | LP_IMAGE_PLANE_UNIFORM_FLAG ..... | 42 | +| 8.4.19 | RESERVED_J_BIT ..... | 42 | +| 8.4.20 | HP_IMAGE_PLANE_UNIFORM_FLAG ..... | 42 | +| 8.4.21 | BYTE_ALIGNMENT_BIT ..... | 42 | +| 8.4.22 | DC_QP() ..... | 42 | +| 8.4.23 | LP_QP() ..... | 43 | +| 8.4.24 | HP_QP() ..... | 44 | +| 8.5 | INDEX_TABLE_TILES() ..... | 45 | +| 8.5.1 | Syntax structure ..... | 45 | +| 8.5.2 | INDEX_TABLE_STARTCODE ..... | 45 | +| 8.5.3 | IndexOffsetTile[n] ..... | 45 | +| 8.6 | PROFILE_LEVEL_INFO() ..... | 45 | +| 8.6.1 | Syntax structure ..... | 45 | +| 8.6.2 | PROFILE_IDC ..... | 46 | +| 8.6.3 | LEVEL_IDC ..... | 46 | +| 8.6.4 | RESERVED_L ..... | 46 | +| 8.6.5 | LAST_FLAG ..... | 46 | +| 8.7 | CODED_TILES() ..... | 46 | +| 8.7.1 | Syntax structure ..... | 46 | +| 8.7.2 | TILE_SPATIAL() ..... | 47 | +| 8.7.3 | TILE_DC() ..... | 48 | +| 8.7.4 | TILE_HEADER_DC() ..... | 48 | +| 8.7.5 | TILE_LOWPASS() ..... | 49 | +| 8.7.6 | TILE_HEADER_LOWPASS() ..... | 49 | +| 8.7.7 | TILE_HIGHPASS() ..... | 50 | +| 8.7.8 | TILE_HEADER_HIGHPASS() ..... | 51 | +| 8.7.9 | TILE_FLEXBITS() ..... | 51 | +| 8.7.10 | Tile-level semantics ..... | 51 | +| 8.7.11 | MB_DC() ..... | 54 | +| 8.7.12 | DECODE_DC() ..... | 55 | +| 8.7.13 | DECODE_ABS_LEVEL() ..... | 55 | +| 8.7.14 | Macroblock DC() semantics ..... | 56 | +| 8.7.15 | Macroblock lowpass ..... | 57 | +| 8.7.16 | General ..... | 57 | +| 8.7.17 | Coded block pattern highpass (CBPHP) ..... | 61 | +| 8.7.18 | Macroblock highpass ..... | 67 | +| 8.7.19 | Macroblock FLEXBITS ..... | 75 | +| 8.8 | Adaptive VLC code table selection ..... | 76 | +| 8.8.1 | General ..... | 76 | +| 8.8.2 | Adaptive VLC deltaDisc tables ..... | 77 | +| 8.8.3 | Initialization ..... | 79 | +| 8.8.4 | Update of adaptive VLC code table selection ..... | 81 | +| 8.9 | Adaptation of CBPLP state variables ..... | 84 | +| 8.9.1 | General ..... | 84 | +| 8.9.2 | InitializeCountCBPLP() ..... | 84 | +| 8.9.3 | UpdateCountCBPLP() ..... | 84 | +| 8.10 | Adaptive CBPHP prediction ..... | 84 | +| 8.10.1 | InitializeCBPHPModel() ..... | 84 | +| 8.10.2 | UpdateCBPHPModel() ..... | 84 | + +| | | | +|--------|----------------------------------------------------------|-----| +| 8.11 | Adaptive inverse scanning ..... | 85 | +| 8.11.1 | Adaptive inverse scanning tables ..... | 85 | +| 8.11.2 | InitializeAdaptiveScanLP( ) ..... | 86 | +| 8.11.3 | InitializeAdaptiveScanHP( ) ..... | 86 | +| 8.11.4 | ResetTotalsAdaptiveScanLP( ) ..... | 86 | +| 8.11.5 | ResetTotalsAdaptiveScanHP( ) ..... | 86 | +| 8.11.6 | AdaptiveLPScan( ) ..... | 87 | +| 8.11.7 | AdaptiveHPScan( ) ..... | 87 | +| 8.12 | Adaptive coefficient normalization ..... | 88 | +| 8.12.1 | InitializeModelMB( ) ..... | 88 | +| 8.12.2 | UpdateModelMB( ) ..... | 88 | +| 9 | Decoding process ..... | 89 | +| 9.1 | General ..... | 89 | +| 9.2 | Image decoding ..... | 89 | +| 9.3 | Image plane decoding ..... | 90 | +| 9.4 | Tile transform coefficient processing ..... | 90 | +| 9.4.1 | Overview ..... | 90 | +| 9.4.2 | DC transform coefficient decoding ..... | 91 | +| 9.4.3 | Lowpass transform coefficient decoding ..... | 91 | +| 9.4.4 | Highpass transform coefficient decoding ..... | 91 | +| 9.5 | Coefficient remapping ..... | 92 | +| 9.5.1 | DC coefficient remapping ..... | 92 | +| 9.5.2 | Lowpass coefficient remapping ..... | 92 | +| 9.5.3 | Highpass macroblock coefficient remapping ..... | 93 | +| 9.5.4 | Highpass block coefficient remapping ..... | 93 | +| 9.6 | Transform coefficient prediction ..... | 93 | +| 9.6.1 | DC coefficient prediction ..... | 93 | +| 9.6.2 | Lowpass prediction ..... | 96 | +| 9.6.3 | Highpass prediction ..... | 98 | +| 9.7 | Derivation of quantization parameters ..... | 102 | +| 9.7.1 | Derivation of DC quantization parameters ..... | 102 | +| 9.7.2 | Derivation of lowpass quantization parameters ..... | 103 | +| 9.7.3 | Derivation of highpass quantization parameters ..... | 104 | +| 9.8 | Dequantization ..... | 105 | +| 9.8.1 | Dequantization of DC coefficients ..... | 105 | +| 9.8.2 | Dequantization of lowpass coefficients ..... | 106 | +| 9.8.3 | Dequantization of highpass coefficients ..... | 106 | +| 9.8.4 | QuantMap( ) ..... | 107 | +| 9.9 | Sample reconstruction ..... | 108 | +| 9.9.1 | Overview ..... | 108 | +| 9.9.2 | First level inverse transform ..... | 108 | +| 9.9.3 | First level overlap filtering ..... | 109 | +| 9.9.4 | Second level coefficient combination ..... | 121 | +| 9.9.5 | Second level inverse transform ..... | 122 | +| 9.9.6 | Second level overlap filtering ..... | 123 | +| 9.9.7 | Inverse transform basic operations ..... | 129 | +| 9.9.8 | Overlap filtering functions ..... | 132 | +| 9.10 | Output formatting ..... | 136 | +| 9.10.1 | Overview ..... | 136 | +| 9.10.2 | Output formatting stage ..... | 136 | +| 9.10.3 | Sampling conversion ..... | 137 | +| 9.10.4 | Conversion from INTERNAL_CLR_FMT to OUTPUT_CLR_FMT ..... | 139 | +| 9.10.5 | AddBias( ) ..... | 142 | +| 9.10.6 | ComputeScaling( ) ..... | 143 | +| 9.10.7 | Postscaling process ..... | 144 | +| 9.10.8 | Clipping and packing stage ..... | 146 | + +| | | | +|---------|----------------------------------------------------------------------------------------|-----| +| Annex A | Tag-based file format ..... | 150 | +| A.1 | General ..... | 150 | +| A.2 | Normative references ..... | 150 | +| A.2.1 | Identical Recommendations International Standards ..... | 150 | +| A.2.2 | Paired Recommendations International Standards equivalent in technical content... .. | 150 | +| A.2.3 | Additional references ..... | 150 | +| A.3 | Definitions ..... | 150 | +| A.4 | Abbreviations ..... | 151 | +| A.5 | FILE_HEADER() ..... | 151 | +| A.5.1 | Syntax structure ..... | 151 | +| A.5.2 | FIXED_FILE_HEADER_II_2BYTES ..... | 151 | +| A.5.3 | FIXED_FILE_HEADER_0XBC_BYTE ..... | 151 | +| A.5.4 | FILE_VERSION_ID ..... | 151 | +| A.5.5 | FIRST_IFD_OFFSET ..... | 151 | +| A.6 | IMAGE_FILE_DIRECTORY() ..... | 152 | +| A.6.1 | Syntax structure ..... | 152 | +| A.6.2 | NUM_ENTRIES ..... | 152 | +| A.6.3 | ZERO_OR_NEXT_IFD_OFFSET ..... | 152 | +| A.7 | IFD_ENTRY() ..... | 152 | +| A.7.1 | Syntax structure ..... | 152 | +| A.7.2 | FIELD_TAG ..... | 154 | +| A.7.3 | ELEMENT_TYPE ..... | 154 | +| A.7.4 | NUM_ELEMENTS ..... | 155 | +| A.7.5 | VALUES_OR_OFFSET ..... | 155 | +| A.7.6 | DOCUMENT_NAME ..... | 155 | +| A.7.7 | IMAGE_DESCRIPTION ..... | 155 | +| A.7.8 | EQUIPMENT_MAKE ..... | 155 | +| A.7.9 | EQUIPMENT_MODEL ..... | 155 | +| A.7.10 | PAGE_NAME ..... | 156 | +| A.7.11 | PAGE_NUMBER ..... | 156 | +| A.7.12 | SOFTWARE_NAME_VERSION ..... | 156 | +| A.7.13 | DATE_TIME ..... | 156 | +| A.7.14 | ARTIST_NAME ..... | 157 | +| A.7.15 | HOST_COMPUTER ..... | 157 | +| A.7.16 | COPYRIGHT_NOTICE ..... | 157 | +| A.7.17 | COLOR_SPACE ..... | 158 | +| A.7.18 | PIXEL_FORMAT ..... | 158 | +| A.7.19 | SPATIAL_XFRM_PRIMARY ..... | 166 | +| A.7.20 | IMAGE_TYPE ..... | 166 | +| A.7.21 | PTM_COLOR_INFO() ..... | 167 | +| A.7.22 | PROFILE_LEVEL_CONTAINER() ..... | 174 | +| A.7.23 | IMAGE_WIDTH ..... | 174 | +| A.7.24 | IMAGE_HEIGHT ..... | 174 | +| A.7.25 | WIDTH_RESOLUTION ..... | 174 | +| A.7.26 | HEIGHT_RESOLUTION ..... | 174 | +| A.7.27 | IMAGE_OFFSET ..... | 174 | +| A.7.28 | IMAGE_BYTE_COUNT ..... | 174 | +| A.7.29 | ALPHA_OFFSET ..... | 175 | +| A.7.30 | ALPHA_BYTE_COUNT ..... | 175 | +| A.7.31 | IMAGE_BAND_PRESENCE ..... | 175 | +| A.7.32 | ALPHA_BAND_PRESENCE ..... | 175 | +| A.7.33 | PADDING_DATA ..... | 175 | +| Annex B | Profiles and levels ..... | 177 | +| B.1 | General ..... | 177 | +| B.2 | Profiles ..... | 177 | +| B.2.1 | Sub-baseline profile ..... | 177 | +| B.2.2 | Baseline profile ..... | 177 | + +| | | | +|---------|-------------------------------------------------------------------------------------------------|-----| +| B.2.3 | Main profile..... | 178 | +| B.2.4 | Advanced profile..... | 178 | +| B.2.5 | Reserved values of PROFILE_IDC ..... | 178 | +| B.3 | Levels..... | 178 | +| Annex C | Colour imagery representation and colour management ..... | 180 | +| C.1 | Background information ..... | 180 | +| C.2 | Colour interpretation in the JPEG XR context ..... | 180 | +| Annex D | Encoder processing ..... | 183 | +| D.1 | Overview ..... | 183 | +| D.2 | Pre-scaling..... | 183 | +| D.3 | Colour conversion ..... | 185 | +| D.3.1 | General ..... | 185 | +| D.3.2 | FwdColorFmtConvert1( )..... | 185 | +| D.3.3 | FwdColorFmtConvert2( )..... | 185 | +| D.3.4 | FwdColorFmtConvert3( )..... | 186 | +| D.3.5 | Macroblock alignment and padding ..... | 186 | +| D.4 | Transform..... | 186 | +| D.4.1 | T2x2h( )..... | 188 | +| D.4.2 | TOdd( )..... | 188 | +| D.4.3 | TOddOdd( )..... | 188 | +| D.4.4 | FwdPermute( )..... | 188 | +| D.4.5 | FCT operations..... | 189 | +| D.5 | Overlap pre-filtering..... | 190 | +| D.5.1 | Overview ..... | 190 | +| D.5.2 | OverlapPreFilter4( ) ..... | 193 | +| D.5.3 | OverlapPreFilter2x2 ..... | 194 | +| D.5.4 | OverlapPreFilter2 ..... | 194 | +| D.6 | Coefficient prediction..... | 194 | +| D.7 | Coefficient scanning..... | 194 | +| D.8 | Quantization ..... | 194 | +| D.9 | Adaptive coefficient normalization ..... | 195 | +| Annex E | Media type specification for the Annex A tag-based file format ..... | 196 | +| E.1 | General ..... | 196 | +| E.2 | Registration ..... | 196 | +| Annex F | Storage in the ISO/IEC 23008-12 image file format and associated media type registrations ..... | 198 | +| F.1 | General ..... | 198 | +| F.2 | Normative references ..... | 198 | +| F.2.1 | Identical Recommendations International Standards ..... | 198 | +| F.2.2 | Paired Recommendations International Standards equivalent in technical content... 198 | | +| F.2.3 | Additional references ..... | 198 | +| F.3 | JPEG XR images and image collections ..... | 198 | +| F.3.1 | General ..... | 198 | +| F.3.2 | Image data ..... | 198 | +| F.3.3 | JPEG XR header item property ..... | 199 | +| F.3.4 | JPEG XR info item property ..... | 199 | +| F.3.5 | JPEG XR profile item property ..... | 200 | +| F.4 | JPEG XR image sequences ..... | 200 | +| F.4.1 | General ..... | 200 | +| F.4.2 | Derivation from ISO/IEC 14496-12 and Rec. ITU-T T.833 ISO/IEC 29199-3 ..... | 200 | + +| | | | +|--------------------|------------------------------------------------------------------------------------------------------------------|-----| +| F.5 | JPEG XR-specific brands ..... | 200 | +| F.5.1 | JPEG XR image and image collection brands ..... | 200 | +| F.5.2 | JPEG XR image sequence brands ..... | 201 | +| F.6 | Media type registration for JPEG XR coded images and image collections in the ISO/IEC 23008-12 image file format | 202 | +| F.6.1 | General ..... | 202 | +| F.6.2 | Registration ..... | 202 | +| F.7 | Media type registration for JPEG XR coded image sequences in the ISO/IEC 23008-12 file format | 203 | +| F.7.1 | General ..... | 203 | +| F.7.2 | Registration ..... | 203 | +| Bibliography ..... | | 205 | + +## LIST OF FIGURES + +| | Page | +|------------------------------------------------------------------------------------------------------------------------------------------------------|------| +| Figure 1 – Informative overview of image partitions and internal windowing..... | 22 | +| Figure 2 – Informative overview of codestream structure. Image header is followed by a sequence of tiles which are in spatial or frequency mode..... | 23 | +| Figure 3 – Informative decoding process block diagram..... | 24 | +| Figure 4 – Informative overview of sample reconstruction process ..... | 27 | +| Figure 5 – DC and LP coefficients in (a) 4×4, (b) 422 chroma, and (c) 420 chroma block ..... | 96 | +| Figure 6 – HP prediction from left..... | 99 | +| Figure D.1 – Encoder transform ..... | 187 | +| Figure D.2 – Representation of the adaptive normalization process and partitioning of coefficients into VLC coded and FLC coded parts..... | 195 | + +## LIST OF TABLES + +| | Page | +|--------------------------------------------------------------------------------------------------|------| +| Table 1 – Precedence order of operators..... | 8 | +| Table 2 – Example of a pseudocode table ..... | 8 | +| Table 3 – Example of a pseudocode comment ..... | 9 | +| Table 4 – Example of a pseudocode while statement ..... | 9 | +| Table 5 – Example of a pseudocode for statement ..... | 9 | +| Table 6 – Example of a pseudocode conditional statement ..... | 9 | +| Table 7 – Example of the initialization of values in an array in pseudocode..... | 9 | +| Table 8 – Definition of mathematical function Max( ) ..... | 10 | +| Table 9 – Definition of mathematical function Min( )..... | 10 | +| Table 10 – Definition of mathematical function Abs( ) ..... | 10 | +| Table 11 – Definition of mathematical function Sign( ) ..... | 11 | +| Table 12 – Definition of mathematical function Round( )..... | 11 | +| Table 13 – Definition of mathematical function Clip( ) ..... | 11 | +| Table 14 – Definition of mathematical function Numones( ) ..... | 12 | +| Table 15 – Syntax table example..... | 13 | +| Table 16 – Defined mnemonic values ..... | 14 | +| Table 17 – Pseudocode to calculate chroma component array sizes..... | 21 | +| Table 18 – CODED_IMAGE( ) syntax structure..... | 28 | +| Table 19 – VLW_ESC( ) syntax structure ..... | 29 | +| Table 20 – IMAGE_HEADER( ) syntax structure ..... | 30 | +| Table 21 – Interpretation of SPATIAL_XFRM_SUBORDINATE..... | 32 | +| Table 22 – OUTPUT_CLR_FMT..... | 34 | +| Table 23 – OUTPUT_BITDEPTH ..... | 35 | +| Table 24 – Pseudocode to determine the position of the left boundaries of the tiles ..... | 36 | +| Table 25 – Pseudocode to determine the position of the top boundaries of the tiles ..... | 36 | +| Table 26 – Pseudocode to determine the number of macroblocks in each tile ..... | 37 | +| Table 27 – IMAGE_PLANE_HEADER( ) syntax structure ..... | 38 | +| Table 28 – INTERNAL_CLR_FMT ..... | 39 | +| Table 29 – BANDS_PRESENT ..... | 39 | +| Table 30 – Pseudocode to determine the number of bands present in the codestream, NumBands ..... | 39 | +| Table 31 – Pseudocode to determine the number of components present in the codestream ..... | 41 | +| Table 32 – DC_QP( ) syntax structure..... | 42 | +| Table 33 – COMPONENT_MODE..... | 43 | +| Table 34 – LP_QP( ) syntax structure..... | 43 | + +| | | +|----------------------------------------------------------------------------------------------------------|----| +| Table 35 – HP_QP( ) syntax structure ..... | 44 | +| Table 36 – INDEX_TABLE_TILES( ) syntax structure ..... | 45 | +| Table 37 – PROFILE_LEVEL_INFO( ) syntax structure ..... | 45 | +| Table 38 – CODED_TILES( ) syntax structure ..... | 46 | +| Table 39 – TILE_SPATIAL( ) syntax structure ..... | 47 | +| Table 40 – TILE_DC( ) syntax structure ..... | 48 | +| Table 41 – TILE_HEADER_DC( ) syntax structure ..... | 48 | +| Table 42 – TILE_LOWPASS( ) syntax structure ..... | 49 | +| Table 43 – TILE_HEADER_LOWPASS( ) syntax structure ..... | 49 | +| Table 44 – TILE_HIGHPASS( ) syntax structure ..... | 50 | +| Table 45 – TILE_HEADER_HIGHPASS( ) syntax structure ..... | 51 | +| Table 46 – TILE_FLEXBITS( ) syntax structure ..... | 51 | +| Table 47 – DECODE_QP_INDEX( ) syntax structure ..... | 53 | +| Table 48 – MB_DC( ) syntax structure ..... | 54 | +| Table 49 – DECODE_DC( ) syntax structure ..... | 55 | +| Table 50 – DECODE_ABS_LEVEL( ) syntax structure ..... | 55 | +| Table 51 – Code table for VAL_DC_YUV ..... | 56 | +| Table 52 – Code table for ABS_LEVEL_INDEX ..... | 57 | +| Table 53 – MB_LP( ) syntax structure ..... | 58 | +| Table 54 – REFINE_LP( ) syntax structure ..... | 60 | +| Table 55 – Code table for CBPLP_YUV1 when INTERNAL_CLR_FMT is equal to YUV444 ..... | 60 | +| Table 56 – Code table for CBPLP_YUV1 when INTERNAL_CLR_FMT is equal to YUV420 or YUV422 ..... | 60 | +| Table 57 – MB_CBPHP( ) syntax structure ..... | 62 | +| Table 58 – REFINE_CBPHP( ) syntax structure ..... | 63 | +| Table 59 – Code table for NUM_CBPHP( ) ..... | 64 | +| Table 60 – Code table for NUM_BLKCBPHP if INTERNAL_CLR_FMT is one of {YUVK, NCOMPONENT, YONLY} ..... | 64 | +| Table 61 – Code table for NUM_BLKCBPHP if INTERNAL_CLR_FMT is not one of {YUVK, NCOMPONENT, YONLY} ..... | 64 | +| Table 62 – Code table for CHR_CBPHP, VAL_INC, and CBPHP_CH_BLK ..... | 64 | +| Table 63 – Code table for NUM_CH_BLK ..... | 65 | +| Table 64 – Code table for REF_CBPHP1 ..... | 65 | +| Table 65 – Pseudocode for function PredCBPHP( ) ..... | 65 | +| Table 66 – Pseudocode for function PredCBPHP444( ) ..... | 66 | +| Table 67 – Pseudocode for function PredCBPHP422( ) ..... | 66 | + +| | | +|-----------------------------------------------------------------------------------------------------------------|----| +| Table 68 – Pseudocode for function PredCBPHP420( ) ..... | 67 | +| Table 69 – MB_HP( ) syntax structure ..... | 67 | +| Table 70 – MB_HP_FLEX( ) syntax structure ..... | 68 | +| Table 71 – DECODE_BLOCK_ADAPTIVE( ) syntax structure ..... | 69 | +| Table 72 – DECODE_BLOCK( ) syntax structure ..... | 70 | +| Table 73 – DECODE_RUN( ) syntax structure ..... | 71 | +| Table 74 – DECODE_INDEX( ) syntax structure ..... | 71 | +| Table 75 – DECODE_FIRST_INDEX( ) syntax structure ..... | 72 | +| Table 76 – Code table of RUN_VALUE if iMaxRun = = 2 ..... | 72 | +| Table 77 – Code table of RUN_VALUE if iMaxRun = = 3 ..... | 73 | +| Table 78 – Code table of RUN_VALUE if iMaxRun = = 4 ..... | 73 | +| Table 79 – Code table of RUN_INDEX ..... | 73 | +| Table 80 – Code table for INDEX_A ..... | 73 | +| Table 81 – Code table for INDEX_B ..... | 74 | +| Table 82 – Code table for FIRST_INDEX ..... | 74 | +| Table 83 – MB_FLEXBITS( ) syntax structure ..... | 75 | +| Table 84 – BLOCK_FLEXBITS( ) syntax structure ..... | 76 | +| Table 85 – DECODE_FLEX( ) syntax structure ..... | 76 | +| Table 86 – Constant table AbslevelIndexDelta[m][n] ..... | 77 | +| Table 87 – Constant table FirstIndexDelta[m][n] ..... | 78 | +| Table 88 – Constant table Index1Delta[m][n] ..... | 78 | +| Table 89 – Constant table NumCBPHPDelta[m][n] ..... | 78 | +| Table 90 – Constant table NumBlkCBPHPDelta[m][n] when INTERNAL_CLR_FMT is
YONLY, NCOMPONENT, or YUVK ..... | 79 | +| Table 91 – Constant table NumBlkCBPHPDelta for INTERNAL_CLR_FMT other than
YONLY, NCOMPONENT, and YUVK ..... | 79 | +| Table 92 – Pseudocode for function InitializeDCVLC( ) ..... | 80 | +| Table 93 – Pseudocode for function InitializeLPVLC( ) ..... | 80 | +| Table 94 – Pseudocode for function InitializeHPVLC( ) ..... | 80 | +| Table 95 – Pseudocode for function InitializeCBPHPVLC( ) ..... | 80 | +| Table 96 – Pseudocode for function InitializeVLCTable1( ) ..... | 81 | +| Table 97 – Pseudocode for function InitializeVLCTable2( ) ..... | 81 | +| Table 98 – Pseudocode for function AdaptDC( ) ..... | 81 | +| Table 99 – Pseudocode for function AdaptLP( ) ..... | 82 | +| Table 100 – Pseudocode for function AdaptHP( ) ..... | 82 | + +| | | +|---------------------------------------------------------------------------------|----| +| Table 101 – Pseudocode for function AdaptVLCTable1( ) ..... | 82 | +| Table 102 – Pseudocode for function AdaptVLCTable2( ) ..... | 83 | +| Table 103 – Pseudocode for function InitializeCountCBPLP( ) ..... | 84 | +| Table 104 – Pseudocode for function UpdateCountCBPLP( ) ..... | 84 | +| Table 105 – Pseudocode for function InitializeCBPHPModel( ) ..... | 84 | +| Table 106 – Pseudocode for function UpdateCBPHPModel( ) ..... | 85 | +| Table 107 – Definitions of ScanOrder0 and ScanOrder1 ..... | 85 | +| Table 108 – Definition of ScanTotals ..... | 85 | +| Table 109 – Pseudocode for function InitializeAdaptiveScanLP( ) ..... | 86 | +| Table 110 – Pseudocode for function InitializeAdaptiveScanHP( ) ..... | 86 | +| Table 111 – Pseudocode for function ResetTotalsAdaptiveScanLP( ) ..... | 86 | +| Table 112 – Pseudocode for function ResetTotalsAdaptiveScanHP( ) ..... | 86 | +| Table 113 – Pseudocode for function AdaptiveLPScan( ) ..... | 87 | +| Table 114 – Pseudocode for function AdaptiveHPScan( ) ..... | 87 | +| Table 115 – Pseudocode for function InitializeModelMB( ) ..... | 88 | +| Table 116 – Pseudocode for function UpdateModelMB( ) ..... | 88 | +| Table 117 – Pseudocode for function ImageDecoding( ) ..... | 89 | +| Table 118 – Pseudocode for function ImagePlaneDecoding( ) ..... | 90 | +| Table 119 – Pseudocode for function TileTransformCoefficientProcessing( ) ..... | 91 | +| Table 120 – Pseudocode for function DCTransformCoefficientDecoding( ) ..... | 91 | +| Table 121 – Pseudocode for function LPTransformCoefficientDecoding( ) ..... | 91 | +| Table 122 – Pseudocode for function HPTransformCoefficientDecoding( ) ..... | 92 | +| Table 123 – Pseudocode for function DCMBCoefficientRemap( ) ..... | 92 | +| Table 124 – Pseudocode for function LPMBCoefficientRemap( ) ..... | 92 | +| Table 125 – Pseudocode for function HPMBCoefficientRemap( ) ..... | 93 | +| Table 126 – Pseudocode for function HPBlockCoefficientRemap( ) ..... | 93 | +| Table 127 – Pseudocode for function DCPredictionGeneral( ) ..... | 94 | +| Table 128 – Pseudocode for function CalcDCPredMode( ) ..... | 94 | +| Table 129 – Pseudocode for function DCCoefficientPrediction( ) ..... | 95 | +| Table 130 – Pseudocode for function UpdateDCPredictionVariables( ) ..... | 96 | +| Table 131 – Pseudocode for function LPPredictionGeneral( ) ..... | 97 | +| Table 132 – Pseudocode for function CalcLPPredMode( ) ..... | 97 | +| Table 133 – Pseudocode for function LPCoefficientPrediction( ) ..... | 97 | +| Table 134 – Pseudocode for function UpdateLPPredictionVariables( ) ..... | 98 | + +| | | +|---------------------------------------------------------------------------------|-----| +| Table 135 – Pseudocode for function CalcHPPredMode( ) ..... | 100 | +| Table 136 – Pseudocode for function HPCoefficientPrediction( ) ..... | 100 | +| Table 137 – Pseudocode for function ImagePlaneDCQP( ) ..... | 102 | +| Table 138 – Pseudocode for function TileLevelDCQP( ) ..... | 102 | +| Table 139 – Pseudocode for function AssignDCQuantizationParameters( ) ..... | 102 | +| Table 140 – Pseudocode for function ImagePlaneLPQP( ) ..... | 103 | +| Table 141 – Pseudocode for function TileLevelLPQP( ) ..... | 103 | +| Table 142 – Pseudocode for function AssignLPQuantizationParameters( ) ..... | 104 | +| Table 143 – Pseudocode for function ImagePlaneHPQP( ) ..... | 104 | +| Table 144 – Pseudocode for function TileLevelHPQP( ) ..... | 105 | +| Table 145 – Pseudocode for function AssignHPQuantizationParameters( ) ..... | 105 | +| Table 146 – Pseudocode for function DequantizeDCCoefficients( ) ..... | 106 | +| Table 147 – Pseudocode for function DequantizeLPCoefficients( ) ..... | 106 | +| Table 148 – Pseudocode for function DequantizeHPCoefficients( ) ..... | 107 | +| Table 149 – Pseudocode for function QuantMap( ) ..... | 107 | +| Table 150 – Pseudocode for function SampleReconstruction( ) ..... | 108 | +| Table 151 – Pseudocode for function FirstLevelInverseTransform( ) ..... | 109 | +| Table 152 – Pseudocode for function FirstLevelOverlapFiltering( ) ..... | 110 | +| Table 153 – Pseudocode for function FirstLevelOverlapFilteringPrimary( ) ..... | 110 | +| Table 154 – Pseudocode for function FirstLevelOverlapFiltering422( ) ..... | 114 | +| Table 155 – Pseudocode for function FirstLevelOverlapFiltering420( ) ..... | 118 | +| Table 156 – Pseudocode for function FirstLevelCallOverlapPostFilter4x4( ) ..... | 121 | +| Table 157 – Pseudocode for function SecondLevelCoefficientCombination( ) ..... | 122 | +| Table 158 – Pseudocode for function SecondLevelInverseTransform( ) ..... | 123 | +| Table 159 – Pseudocode for function SecondLevelOverlapFiltering( ) ..... | 123 | +| Table 160 – Pseudocode for function ICT4x4( ) ..... | 129 | +| Table 161 – Pseudocode for function T2x2h( ) ..... | 130 | +| Table 162 – Pseudocode for function InvTodd( ) ..... | 131 | +| Table 163 – Pseudocode for function InvToddodd ..... | 131 | +| Table 164 – Inverse Permutation ..... | 131 | +| Table 165 – Pseudocode for function InvPermute( ) ..... | 132 | +| Table 166 – Pseudocode for function InvPermute2pt( ) ..... | 132 | +| Table 167 – Pseudocode for function T2pt( ) ..... | 132 | + +| | | +|-----------------------------------------------------------------------------------------------------------------|-----| +| Table 168 – Pseudocode for function OverlapPostFilter4x4( ) ..... | 133 | +| Table 169 – Pseudocode for function OverlapPostFilter4( ) ..... | 134 | +| Table 170 – Pseudocode for function OverlapPostFilter2x2( ) ..... | 135 | +| Table 171 – Pseudocode for function OverlapPostFilter2( ) ..... | 135 | +| Table 172 – Pseudocode for function InvRotate( ) ..... | 135 | +| Table 173 – Pseudocode for function InvScale( ) ..... | 135 | +| Table 174 – Pseudocode for function T2x2hPOST( ) ..... | 136 | +| Table 175 – Pseudocode for function InvToddoddPOST( ) ..... | 136 | +| Table 176 – Conformance-specified output formatting combinations of OUTPUT_BITDEPTH and
OUTPUT_CLR_FMT ..... | 137 | +| Table 177 – Pseudocode for function OutputFormatting( ) ..... | 137 | +| Table 178 – Pseudocode for function SamplingConversion( ) ..... | 138 | +| Table 179 – Conformance-specified sampling conversions ..... | 138 | +| Table 180 – Pseudocode for function Upsample( ) ..... | 138 | +| Table 181 – Upsampling filter coefficient for different chroma positions ..... | 139 | +| Table 182 – Pseudocode for function ConvertInternalToOutputClrFmt( ) ..... | 139 | +| Table 183 – Conformance-specified color format conversions ..... | 140 | +| Table 184 – Pseudocode for function InvColorFmtConvert1( ) ..... | 140 | +| Table 185 – Pseudocode for function InvColorFmtConvert2( ) ..... | 141 | +| Table 186 – Pseudocode for function InvColorFmtConvert3( ) ..... | 141 | +| Table 187 – Pseudocode for function InvColorFmtConvert4( ) ..... | 141 | +| Table 188 – Pseudocode for function AddBias( ) ..... | 142 | +| Table 189 – Pseudocode for function ComputeScaling( ) ..... | 143 | +| Table 190 – Pseudocode for function PostscalingProcess( ) ..... | 144 | +| Table 191 – Pseudocode for function PostScalingInt( ) ..... | 144 | +| Table 192 – Pseudocode for function PostScalingF1( ) ..... | 145 | +| Table 193 – Pseudocode for function PostScalingF2( ) ..... | 145 | +| Table 194 – Pseudocode for function ClippingAndPackingStage( ) ..... | 146 | +| Table 195 – Pseudocode for function ClippingBasic( ) ..... | 147 | +| Table 196 – Pseudocode for function ClipAndPackBD565( ) ..... | 148 | +| Table 197 – Pseudocode for function ClipAndPackBD5( ) ..... | 148 | +| Table 198 – Pseudocode for function ClipAndPackBD10( ) ..... | 148 | +| Table 199 – Pseudocode for function ClipAndPackBD10BorW( ) ..... | 149 | +| Table A.1 – FILE_HEADER( ) syntax structure ..... | 151 | +| Table A.2 – IMAGE_FILE_DIRECTORY( ) syntax structure ..... | 152 | + +| | | +|------------------------------------------------------------------------------------------------------------------------------|-----| +| Table A.3 – IFD_ENTRY( ) syntax structure..... | 152 | +| Table A.4 – Interpretation, allowed combinations, and presence of syntax elements of the IFD_ENTRY( ) syntax structure ..... | 153 | +| Table A.5 – ELEMENT_TYPE..... | 154 | +| Table A.6 – Interpretation of PIXEL_FORMAT..... | 160 | +| Table A.7 – PTM_COLOR_INFO( ) syntax structure..... | 167 | +| Table A.8 – Interpretation of COLOR_PRIMARIES syntax element..... | 167 | +| Table A.9 – Interpretation of TRANSFER_CHARACTERISTICS syntax element ..... | 169 | +| Table A.10 – Interpretation of MATRIX_COEFFICIENTS syntax element ..... | 170 | +| Table A.11 – Interpretation of IMAGE_BAND_PRESENCE and ALPHA_BAND_PRESENCE ..... | 175 | +| Table B.1 – Parameters of levels of conformance to this Specification..... | 179 | +| Table B.2 – Pseudocode for function ImageBufferBytes(valNC) ..... | 179 | +| Table D.1 – Pseudocode for function PreScaling1( )..... | 183 | +| Table D.2 – Pseudocode for function PreScalingBD16F( )..... | 183 | +| Table D.3 – Pseudocode for function PreScalingBD32F( )..... | 184 | +| Table D.4 – Pseudocode for function PreScalingRGBE( )..... | 184 | +| Table D.5 – Pseudocode for function RGBEForwardConversion( ) ..... | 184 | +| Table D.6 – Pseudocode for function FwdColorFmtConvert1( )..... | 185 | +| Table D.7 – Pseudocode for function FwdColorFmtConvert2( )..... | 186 | +| Table D.8 – Pseudocode for function FwdColorFmtConvert3( )..... | 186 | +| Table D.9 – Pseudocode for function TOdd( )..... | 188 | +| Table D.10 – Pseudocode for function TOddOdd( )..... | 188 | +| Table D.11 – Forward Permutation ..... | 189 | +| Table D.12 – Pseudocode for function FwdPermute( )..... | 189 | +| Table D.13 – Pseudocode for function FCT4x4( )..... | 189 | +| Table D.14 – Pseudocode for function T2x2hEnc( ) ..... | 191 | +| Table D.15 – Pseudocode for function FwdRotate( ) ..... | 191 | +| Table D.16 – Pseudocode for function FwdScale( ) ..... | 191 | +| Table D.17 – Pseudocode for function FwdTOddOdd( )..... | 191 | +| Table D.18 – Pseudocode for function OverlapPreFilter4x4( ) ..... | 192 | +| Table D.19 – Pseudocode for function OverlapPreFilter4( ) ..... | 193 | +| Table D.20 – Pseudocode for function OverlapPreFilter2x2( ) ..... | 194 | +| Table D.21 – Pseudocode for function OverlapPreFilter2( ) ..... | 194 | + +## Introduction + +This Recommendation | International Standard specifies requirements and implementation guidelines for the compressed representation of digital images for storage and interchange in a form referred to as JPEG XR. The JPEG XR design provides a practical coding technology for a broad range of applications with excellent compression capability and important additional functionalities. An input image is typically operated on by an encoder to create a JPEG XR coded image. The decoder then operates on the coded image to produce an output image that is either an exact or approximate reconstruction of the input image. + +The primary intended application of JPEG XR is the representation of continuous-tone still images, such as photographic images. The manner of representation of the compressed image data and the associated decoding process are specified. These processes and representations are generic, i.e., they are applicable to a broad range of applications using compressed colour and grayscale images in communications and computer systems, and within embedded applications, including mobile devices. + +As of 2019, the most widely used digital photography format is a nominal implementation of the first JPEG coding format as specified in Rec. ITU-T T.81 | ISO/IEC 10918-1. This encoding uses a bit depth of 8 for each of three channels, resulting in 256 representable values per channel (a total of 16 777 216 representable colour values). + +More demanding applications may require a bit depth of 16, providing 65 536 representable values for each channel, and resulting in over $2.8 \times 10^{14}$ colour values. Additional scenarios may necessitate even greater bit depths and sample representation formats. When memory or processing power is at a premium, as few as 5 or 6 bit per channel may be used. + +The JPEG XR specification enables greater effective use of compressed imagery with this broadened diversity of application requirements. JPEG XR supports a wide range of colour encoding formats including monochrome, red–green–blue (RGB), cyan–magenta–yellow–key (CMYK) and n-component encodings using a variety of unsigned integer, fixed point, and floating point decoded numerical representations with a variety of bit depths. The primary goal is to provide a compressed format specification appropriate for a wide range of applications while keeping the implementation requirements for encoders and decoders simple. A special focus of the design is support for emerging high dynamic range (HDR) imagery applications. + +JPEG XR combines the benefits of optimized image quality and compression efficiency together with low-complexity encoding and decoding implementation requirements. It also provides an extensive set of additional functionalities, including: + +- high compression capability; +- low computational and memory resource requirements; +- lossless and lossy compression; +- image tile segmentation for random access and large image formats; +- support for low-complexity compressed-domain image manipulations +- support for embedded thumbnail images and progressive resolution refinement; +- embedded codestream scalability for both image resolution and fidelity; +- alpha plane support; +- bit-exact decoder results for fixed and floating point image formats. + +Important detailed design properties include: + +- high performance, embedded system friendly compression; +- small memory footprint; +- integer-only operations with no divides; +- a signal processing structure that is highly amenable to parallel processing; +- use of the same signal processing operations for both lossless and lossy compression operation; +- support for a wide range of decoded sample formats (many of which support HDR imagery): + - monochrome, RGB, CMYK or n-component image representation, + - 8- or 16-bit unsigned integer, + - 16- or 32-bit fixed point, + - 16- or 32-bit floating point, + - several packed bit formats, + - 1-bit per sample monochrome, + +- 5 or 10 bit per sample RGB, +- Radiance red–green–blue–exponent (RGBE). + +The algorithm uses a reversible hierarchical lifting-based lapped biorthogonal transform. The transform has lossless image representation capability and requires only a small number of integer processing operations for both encoding and decoding. The processing is based on $16 \times 16$ macroblocks in the transform domain, which may or may not affect overlapping areas in the spatial domain (with the overlapping property selected under the control of the encoder). The design provides encoding and decoding with a minimal memory footprint suitable for embedded implementations. + +The algorithm provides native support for both RGB and CMYK colour types by converting these colour formats to an internal luma-dominant format through the use of a reversible colour transform. In addition, YUV, monochrome and arbitrary n-channel colour formats are supported. + +The transforms employed are reversible; both lossless and lossy operations are supported using the same algorithm. Using the same algorithm for both types of operation simplifies implementation, which is especially important for embedded applications. + +A wide range of numerical encodings at multiple bit depths are supported: 8-bit and 16-bit formats, as well as additional specialized packed bit formats, are supported for both lossy and lossless compression. (32-bit formats are supported using lossy compression.) Up to 24 bits are retained through the various transforms. While only integer arithmetic is used for internal processing, lossless and lossy coding are supported for floating point and fixed point image data – as well as for integer image formats. + +The main body of this Specification specifies the syntax and semantics of JPEG XR coded images and the associated decoding process that produces an output image from a coded image. Annex A specifies a tag-based file storage format for storage and interchange of such coded images. Annex B specifies profiles and levels, which determine conformance requirements for classes of encoders and decoders. Aspects of colour imagery representations and colour management are discussed in Annex C. The typical expected encoding process is described in Annex D. Annex E contains a media type specification for images encoded according to the tag-based format specified in Annex A. Annex F specifies an alternative file storage format based on ISO/IEC 23008-12 and associated media type specifications for the storage and interchange of JPEG XR coded images and image sequences. + +Corrigendum 1 (2009) and Corrigendum 2 (2011) introduced a set of various minor corrections to Rec. ITU-T T.832 (2009). Further corrections were introduced in a second edition of Rec. ITU-T T.832 (2012). Annex E was added in the third edition (2016) and Annex F was added in the fourth edition (2019). + + + +## Information technology – JPEG XR image coding system – Image coding specification + +### 1 Scope + +This Recommendation | International Standard specifies a coding format, referred to as JPEG XR, which is designed primarily for continuous-tone photographic content. The main body of this Recommendation | International Standard specifies the syntax and semantics of JPEG XR coded images and the associated decoding process. Annex A specifies a tag-based file storage format for the storage and interchange of such coded images. Annex B specifies profiles and levels that determine conformance requirements for classes of encoders and decoders. Aspects of colour imagery representations and colour management are discussed in Annex C. The typical expected encoding process is described in Annex D. Annex E contains a media type specification for images encoded according to the tag-based format specified in Annex A. Annex F specifies an alternative file storage format based on ISO/IEC 23008-12 and associated media type specifications for the storage and interchange of JPEG XR coded images and image sequences. + +### 2 Normative references + +Normative references which have a scope that is limited to the use of the file format specified in Annex A are listed in A.2. Normative references which have a scope that is limited to the use of the file format specified in Annex F are listed in F.2. + +### 3 Definitions + +For the purposes of this Recommendation | International Standard, the following definitions apply. Definitions of terms that have a scope that is limited to the use of the *file format* specified in Annex A are listed in A.3. + +In this clause, *italic* is used to identify all occurrences of terms that are defined in this clause. + +**3.1 adaptive coefficient normalization:** A parsing sub-process where *transform coefficients* are dynamically partitioned into a *VLC-coded part* and a *fixed-length coded part*, in a manner designed to control (i.e., "normalize") bits used to represent the *VLC-coded part*. The *fixed-length coded part* of *DC coefficients* and *lowpass coefficients* is called *FLC refinement* and the *fixed-length coded part* of *highpass coefficients* is called *flexbits*. + +**3.2 adaptive inverse scanning:** A parsing sub-process where the *zigzag scan order* associated with a set of *transform coefficients* is dynamically modified, based on the statistics of previously parsed *transform coefficients*. + +**3.3 adaptive VLC:** A parsing sub-process where the code table associated with *VLC* parsing of a particular *syntax element* is switched, among a finite set of fixed tables, based on the statistics of previously parsed instances of this *syntax element*. + +**3.4 alpha image plane:** An optional secondary *image plane* associated with an *image*, of the same dimensions as the *luma component* of the *primary image plane*. The *alpha image plane* has one *component*, a *luma component*. + +**3.5 block:** An $m \times n$ array of *samples* or an $m \times n$ array of *transform coefficients*. + +**3.6 block index:** An integer in the range 0 to 15, identifying, by its position in *raster scan order*, a particular $4 \times 4$ *block*, within a partition of a $16 \times 16$ *block* into 16 $4 \times 4$ *blocks*. + +**3.7 byte:** A sequence of 8 bits. + +**3.8 byte-aligned:** A bit in a *codestream* is *byte-aligned* if its position is an integer multiple of 8 bits from the beginning of the *codestream*, where the first bit in the *codestream* is at position 0. + +**3.9 chroma:** A *component* of the *primary image plane* with non-zero index or the *transform coefficients* and sample values associated with this *component*. + +**3.10 coded block pattern highpass:** The *coded block pattern highpass* is a *syntax element* indicating the *coded block status*, i.e., the presence or absence of non-zero *highpass transform coefficients*, for each of the *blocks* in the *macroblock*. + +**3.11 coded block pattern lowpass:** The *coded block pattern lowpass* is a *syntax element* indicating the presence or absence of non-zero *lowpass transform coefficients* in the *macroblock*. + +- 3.12 coded block status:** The *coded block status* is an indication of the presence or absence of non-zero *transform coefficients* in that *block*. +- 3.13 codestream:** A sequence of bits contained in a sequence of *bytes* from which syntax elements are parsed, such that the most significant bit of the first *byte* is the first bit of the *codestream*, the next most significant bit of the first *byte* is the second bit of the *codestream*, and so on, to the least significant bit of the first *byte* (which is the eighth bit of the *codestream*), followed by the most significant bit of the second *byte* (which is the ninth bit of the *codestream*), and so on, up to and including the least significant bit of the last *byte* of the sequence of *bytes* (which is the last bit of the *codestream*). +- 3.14 component:** One of the arrays of samples associated with an *image plane*. +- 3.15 context:** A possible value of a specific instance of a *context variable*. +- 3.16 context variable:** A variable used in the *parsing process* to select which data structure is to be used for the *adaptive VLC* parsing of a given syntax element. +- 3.17 DC coefficient:** The first subset when the *transform coefficients*, that are contained in a specific *macroblock* and a specific *component*, are partitioned into 3 subsets. +- 3.18 DC-LP array:** The array of all DC and lowpass (LP) *transform coefficients*, for all *macroblocks* associated with a specific *component*. +- 3.19 decoder:** An embodiment of a *parsing process* and *decoding process*. +- 3.20 decoding process:** The process of computing output sample values from the parsed syntax elements of the *codestream*. +- 3.21 dequantization:** The process of rescaling the quantized *transform coefficients* after their value has been parsed from the *codestream* and before they are presented to the *inverse transform process*. +- 3.22 discriminant:** A collective term for one of DiscrimVal1 or DiscrimVal2, which are the two member variables of an instance of the *adaptive VLC* data structure specified in 5.5.5. +- 3.23 encoder:** An embodiment of an *encoding process*. +- 3.24 encoding process:** The process of converting source sample values into a *codestream* conforming to this Specification. +- 3.25 extended image:** The *image* produced by the *decoding process* prior to *windowing*. The *extended image* has a *luma* array that is an integer multiple of 16 in width and height. +- 3.26 file:** A finite-length sequence of *bytes* that is accessible to a *decoder* in a manner such that the *decoder* can obtain access to the data at specified positions within the sequence of *bytes* (e.g. by storing the entire sequence of *bytes* in random access memory or by performing "position seek" operations to specified positions within the sequence of *bytes*). +- 3.27 file format:** A specified structure for the content of a *file*. +- 3.28 fixed-length code (FLC):** A code which assigns a finite set of allowable bit patterns to a specific set of values, where each bit pattern has the same length. +- 3.29 FLC refinement:** The *fixed-length coded* part of a *DC coefficient* or *lowpass coefficient* that is parsed using adaptive fixed-length codes. +- 3.30 flexbits:** The *fixed-length coded* part of the *highpass coefficient* information which is parsed using adaptive fixed-length codes. +- 3.31 frequency band:** A collective term for one of the following three subsets of the *transform coefficients* for an *image*, which are separately parsed: *DC coefficients*, *lowpass coefficients*, and *highpass coefficients*. +- 3.32 frequency mode:** A *codestream* structure mode where the DC, lowpass, highpass and *flexbits frequency bands* for each *tile* are grouped separately. +- 3.33 hard tiles:** A *codestream* structure mode where the overlap operators are not applied across tile boundaries. Instead, boundary overlap operators are applied at tile boundaries. +- 3.34 highpass coefficients:** The third subset, when the *transform coefficients* that are contained in a specific *macroblock* and a specific *component* are partitioned into three subsets. +- 3.35 image:** The result of the *decoding process*, consisting of a *primary image plane* and an optional *alpha image plane*. +- 3.36 image plane:** A collective term for a grouping of the *components* of the *image*. + +- 3.37 initial level value:** One of two values used to compute the *VLC-coded* part of a *transform coefficient*. +- 3.38 internal colour format:** The colour format associated with the spatial-domain samples obtained through the *inverse transform process* and the *sample reconstruction process*, and distinguished from the *output colour format* associated with the *output formatting process*. +- 3.39 inverse core transform (ICT):** The two steps of the *inverse transform process* that involve processing of *transform coefficients* associated with each *macroblock* independently, with no *overlap filtering*. +- 3.40 inverse transform process:** The part of the *decoding process* by which a set of *dequantized transform coefficients* are converted into spatial-domain values. +- 3.41 inverse scanning:** The process of reordering an ordered set of parsed *syntax elements* from the *codestream* to form an array of *transform coefficients* associated with a specific *component* and *macroblock*. +- 3.42 little-endian form:** An ordering of the *bytes* that represent a numerical value as an integer number of *bytes* in which the *bytes* representing the number are in ascending order of significance, i.e., with the least significant *byte* first, followed by the next least significant *byte*, etc. +- 3.43 lowpass coefficients:** The second subset, when the *transform coefficients* that are contained in a specific *macroblock* and a specific *component* are partitioned into three subsets. +- 3.44 luma:** The *component* of an *image plane* with index zero, and the *transform coefficients* and sample values associated with this *component*. Although this term is commonly associated with a signal that conveys perceptual brightness information, as used in this Specification the term is primarily an identifier of a particular array of samples or *transform coefficients* for an *image*. +- 3.45 macroblock:** The collection of *transform coefficients* or samples, across all *components*, that have the same indices *i* and *j* with respect to a *macroblock partition*. +- 3.46 macroblock partition:** The partitioning of each *component*, into $16 \times 16$ , $8 \times 8$ or $16 \times 8$ *blocks*, depending on the *internal colour format*. +- 3.47 output bit depth:** The representation, including the number of bits and the interpretation of the bit pattern, used for the sample values of the output *image* that are the result of the *decoding process*. +- 3.48 output colour format:** The colour format associated with the output *image* that is the result of the *decoding process*. +- 3.49 output formatting process:** The process of converting the arrays of samples – that are the result of the *sample reconstruction process* – into the output samples that constitute the output of the *decoding process*. This specifies a conversion (if necessary) into the appropriate *output colour format* and *output bit depth*. +- 3.50 output image height:** The height of the sub-array of the *luma component* of the *primary image plane* that is output by the *decoding process*. +- 3.51 output image width:** The width of the sub-array, of the *luma component* of the *primary image plane* that is output by the *decoding process*. +- 3.52 overlap filtering:** The steps of the *inverse transform process* that involve processing of *transform coefficients* across adjacent *blocks* and *macroblocks*. +- NOTE – When *overlap filtering* is applied, it is applied across *macroblock* boundaries as well as *block* boundaries. When the *codestream* uses *soft tiles*, the *overlap filtering* is also applied across *tile* boundaries. Otherwise, *overlap filtering* does not occur across *tile* boundaries. +- 3.53 parsing process:** The process of extracting bit sequences from the *codestream*, converting these bit sequences to syntax element values, and setting the values of global variables for use in the *decoding process*. +- 3.54 prediction:** The process of computing an estimate of the sample value or data element that is currently being decoded. +- 3.55 prediction residual:** The difference between the result of a *prediction* process invoked for a sample or data element and its intended value. +- 3.56 primary image plane:** The *image plane* that consists of all *image components* that are not a part of the *alpha image plane*. +- 3.57 QP index:** An integer, which for a particular *frequency band* and *macroblock* specifies the index into the table of *quantization parameters* available for this *frequency band* and *tile*. This *QP index* thereby selects, for this *macroblock*, the *quantization parameter* used for the *dequantization* of the *transform coefficients* in the specific *frequency band*. + +- 3.58 QP set:** The set of *quantization parameters* associated with a particular *frequency band*, corresponding to the *luma* and *chroma components*. +- 3.59 quantization parameter (QP):** A value used to compute the scaling factor for the *dequantization* of a *transform coefficient*, before the *inverse transform process* is applied. +- 3.60 raster scan order:** The scan order in which a two-dimensional array of values is scanned row-wise from left to right, and the rows are scanned from the top row to the bottom. +- 3.61 refinement:** The process of modifying a predicted or partially computed *transform coefficient*. +- 3.62 run:** The number of zero valued coefficient levels that precede a non-zero valued coefficient level in the *zigzag scan order* during the *inverse scanning process*. +- 3.63 sample reconstruction process:** The process of converting dequantized *transform coefficients* into samples of the *image*. +- 3.64 soft tiles:** A *codestream* structure mode where the overlap operators are applied across tile boundaries. +- 3.65 spatial co-location:** Sub-arrays of samples are *spatially co-located* across *components* when they correspond to the same spatial region of the decoded *image*. The *macroblock partition* of the *image* ensures that the *i*-th *macroblock* horizontally and *j*-th *macroblock* vertically across all *components* are *spatially co-located*. +- 3.66 spatial mode:** A *codestream* structure mode where the *DC*, *lowpass*, *highpass* and *flexbits frequency bands* for each specific *macroblock* are grouped together. +- 3.67 spatial transformation:** An element in the *codestream* indicating the preferred final displayed orientation of the decoded *image*, as specified in 8.3.8. The *spatial transformation* is only a suggestion, and *decoder conformance* is checked only for the decoded *image* prior to the application of this transformation (i.e., for orientation 0). +- 3.68 start code:** A bit pattern that specifies the beginning of a *tile packet* or other distinguished, contiguous set of syntax elements in the *codestream*. +- 3.69 tile:** The collection of *macroblocks* that have the same indices *i* and *j* with respect to a *tile partition*. Each *tile* corresponds to the *macroblocks* for a rectangular region of the *image*. +- 3.70 tile packet:** A contiguous subset of the *codestream*, which contains the coded *syntax elements* associated with a specific *tile*. +- 3.71 tile partition:** A partition of the *image* into rectangular arrays of *macroblocks*, as specified in 6.4. +- 3.72 transform coefficients:** The values, associated with each specific *macroblock* and specific *component*, that – after *dequantization* – form the input arrays into the *inverse transform process*. +- 3.73 variable-length code (VLC):** A code which assigns a finite set of allowable bit patterns to a specific set of values, where each bit pattern is potentially of a different length. +- 3.74 VLC refinement:** One of two values used to compute the *VLC-coded* part of a *transform coefficient*. The number of bits required to specify the *VLC-refinement* is dependent on the value of the *initial level value*. The *VLC refinement* is added to the *initial level value* to produce the *VLC-coded* part of the transform coefficient. +- 3.75 windowing:** A selection of *spatially co-located* sub-arrays of the *components* of all present *image planes* associated with an *image* that are output by the *decoding process*. +- 3.76 zigzag scan order:** An adaptive ordering for the *inverse scanning process*, which assigns array indices to each subsequent *transform coefficient* parsed from the *codestream*. + +## 4 Abbreviations + +For the purposes of this Recommendation | International Standard, the following abbreviations apply. Abbreviations which have a scope that is limited to the use of the file format specified in Annex A are listed in A.4. + +| | | +|-------|------------------------------| +| CBPHP | Coded Block Pattern Highpass | +| CBPLP | Coded Block Pattern Lowpass | +| CMYK | Cyan–Magenta–Yellow–Key | +| DC | Direct Current | +| FCT | Forward Core Transform | +| FLC | Fixed-Length Code | + +| | | +|------|----------------------------------| +| HDR | High Dynamic Range | +| heif | high efficiency image file | +| HP | Highpass | +| ICT | Inverse Core Transform | +| JPEG | Joint Photographic Experts Group | +| LP | Lowpass | +| LSB | Least Significant Bit | +| MSB | Most Significant Bit | +| QP | Quantization Parameter | +| RGB | Red–Green–Blue | +| RGBE | Red–Green–Blue–Exponent | +| VLC | Variable Length Code | +| XR | extended Range | + +## 5 Conventions + +### 5.1 Conformance language + +This Recommendation | International Standard consists of normative and informative text. + +Normative text is text which expresses mandatory requirements. The word "shall" is used to express mandatory requirements to be followed strictly in order to conform to this Specification and from which no deviation is permitted. A conforming implementation is one that fulfils all mandatory requirements. + +Informative text is text that is potentially helpful to the user, but not indispensable and can be removed, changed or added editorially without affecting interoperability. All text in this Recommendation | International Standard is normative, with the following exceptions: the Introduction, any parts of the text that are explicitly labelled as "informative", statements appearing with the preamble "NOTE", behaviour described using the word "should" and pseudocode comments delimited as specified in 5.2.7. The word "should" is used to describe behaviour that is preferred, but is not necessarily required for conformance to this Specification. + +The keywords "may" and "need not" indicate a course of action that is permissible in a conforming implementation. + +The keyword "reserved" indicates a provision that is not specified at this time, shall not be used in implementations conforming to this version of this Specification and may be specified in the future. The keyword "forbidden" indicates "reserved" and in addition indicates that the provision will never be specified in the future. + +### 5.2 Operators + +NOTE – Many of the operators used in this Specification are similar to those used in the C programming language (e.g. as specified in ISO/IEC 9899). + +#### 5.2.1 Arithmetic operators + +| | | +|---------------|--------------------------------------------------------------------------------| +| + | Addition | +| – | Subtraction (as a binary operator) or negation (as a unary prefix operator) | +| ++ | Increment by one as a unary postfix operator | +| -- | Decrement by one as a unary postfix operator | +| * | Multiplication | +| / | Integer division, where the result is truncated towards zero | +| ÷ | Division in mathematical equations where no truncation or rounding is intended | +| $\frac{x}{y}$ | Division in mathematical equations where no truncation or rounding is intended | + +| | | +|---|---------------------------------------------------------------------| +| % | x % a is defined as the modulus operator for $x \geq 0$ and $a > 0$ | +| | x % a is defined as $-((( -x) \% a))$ for $x < 0$ and $a > 0$ | + +NOTE 1 – Although sometimes used as unary prefix operators in the C programming language, the "+" and "-" arithmetic operators are not used as unary prefix operators in this Specification. + +NOTE 2 – The division operators used in this Specification differ somewhat from those used in the C programming language. + +### 5.2.2 Logical operators + +| | | +|----|-------------| +| | Logical OR | +| && | Logical AND | +| ! | Logical NOT | + +TRUE/FALSE convention: + +- When a variable or arithmetic expression having a non-zero value is evaluated as a logical condition or as an element of a logical expression, it is evaluated as TRUE, and when a variable or expression having a zero value is evaluated as a logical condition or as an element of a logical expression, it is evaluated as FALSE. +- When the value of a variable or arithmetic expression is compared to the value TRUE (in text or using a relational operator), it is compared to the value 1, and when the value of a variable or arithmetic expression is compared to the value FALSE (in text or using a relational operator), it is compared to the value 0. +- When a variable is set to the value TRUE, it is set to the value 1; and when a variable is set to the value FALSE, it is set to the value 0. + +### 5.2.3 Relational operators + +| | | +|-----|--------------------------| +| > | Greater than | +| >= | Greater than or equal to | +| < | Less than | +| <= | Less than or equal to | +| = = | Equal to | +| != | Not equal to | + +### 5.2.4 Bit-wise operators + +Bit-wise operators operate on bit pattern values that are produced by conversion of an integer value to an equivalent bit pattern value. Bit-wise operators operate on a two's complement representation of the integer value using a number of bits sufficient to represent the integer value [with a bit equal to 0 in the most significant bit (MSB) of non-negative integer value representations and otherwise with a bit equal to 1 in the MSB]. The result of a bit-wise operator is then interpreted as a two's complement representation of an integer value. The following bit-wise operators are defined: + +| | | +|-----------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| & | AND. When operating on a bit pattern argument that contains fewer bits than the other argument, the shorter argument is extended by adding more significant bits equal to the MSB of the shorter argument, such that the number of bits representing the shorter argument is made the same as the number of bits for the longer argument. | +| | OR. When operating on a bit pattern argument that contains fewer bits than the other argument, the shorter argument is extended by adding more significant bits equal to the MSB of the shorter argument, such that the number of bits representing the shorter argument is made the same as the number of bits for the longer argument. | +| ^ | XOR. When operating on a bit pattern argument that contains fewer bits than the other argument, the shorter argument is extended by adding more significant bits equal to the MSB of the shorter argument, such that the number of bits representing the shorter argument is made the same as the number of bits for the longer argument. | +| $x \gg b$ | Arithmetic right shift of a two's complement integer representation of $x$ by $b$ binary digits, where $b$ is a non-negative integer. Bits shifted into the MSBs as a result of the right shift have a value equal to the MSB of $x$ prior to the shift operation. | +| $x \ll b$ | Arithmetic left shift of a two's complement integer representation of $x$ by $b$ binary digits, where $b$ is a non-negative integer. Bits shifted into the least significant bits (LSBs) as a result of the left shift have a value equal to 0. | + +### 5.2.5 Assignment operators + +| | | +|-----------|---------------------------------------------| +| = | Assignment operator | +| $+=$ | $x += a$ is defined as $x = x + a$ | +| $-=$ | $x -= a$ is defined as $x = x - a$ | +| $\wedge=$ | $x \wedge a$ is defined as $x = x \wedge a$ | +| $*=$ | $x *= a$ is defined as $x = x * a$ | +| $\ll=$ | $x \ll= a$ is defined as $x = (x \ll a)$ | +| $\gg=$ | $x \gg= a$ is defined as $x = (x \gg a)$ | + +### 5.2.6 Precedence order of operators + +Operators are listed below in descending order of precedence. If several operators appear in the same line, they have equal precedence. When several operators of equal precedence appear at the same level in an expression, evaluation proceeds according to the associativity of the operator either from right to left or from left to right. See Table 1. + +**Table 1 – Precedence order of operators** + +| Operators | Type of operation | Associativity | +|--------------------------------|-----------------------------|---------------| +| ( ), [ ], . | Expression | Left to Right | +| ++, -- | Postfix operators | Right to Left | +| -, ! | Unary | | +| *, /, %, $\frac{x}{y}$ | Multiplication and division | Left to Right | +| +, - | Addition and subtraction | Left to Right | +| <<, >> | Arithmetic shift | Left to Right | +| <, >, <=, >= | Relational | Left to Right | +| =, != | Equality test | Left to Right | +| &, , ^ | Bit-wise operator | Left to Right | +| &&, | Logical operators | Left to Right | +| ?, =, *=, +=, -=, ^=, <<=, >>= | Assignment operators | Right to Left | + +### 5.2.7 Pseudocode operations + +Pseudocode is organized into "functions" that are specified in tabular form. A sample pseudocode table is presented in Table 2. Pseudocode statements are each expressed as a row of the table. A group of statements enclosed in curly brackets "{...}" is a compound statement and is treated functionally as a single statement. Each function definition begins with a table row specifying the name of the function, the arguments of the function, and containing the opening curly bracket of a compound statement. + +Arguments passed to a pseudocode function are listed in parentheses after the function name, and are comma delimited. Two types of arguments are used in pseudocode function definitions, as follows: + +- Non-array variables, which are passed by value (e.g., valueArgument1 in Table 2). +- Arrays, which are passed by reference (e.g., arrayArgument2[ ] in Table 2). + +Non-array variables that are passed to a function are addressed within the function using a local variable name, even when a global variable (5.5) has been used when calling the function. Since non-array variables are passed by value rather than by reference, any changes made to the value of the local variable within the function do not affect the value of the (local or global) variable that was used as a calling argument by the invoking process when the function was called. Since arrays are passed to a function by reference rather than by value, any changes made within the function to the values of entries in such an array (specified using a local array name within the function) do persist after the completion of the pseudocode function. Changes made to the values of global variables (5.5) that are specified within a function using the name of the global variable also persist after the completion of the pseudocode function. + +Pseudocode functions may or may not return a value. When a function returns a value, the value that is returned is specified by a "return" statement that appears as the last statement in the compound statement that specifies the function, and the value that is returned is the value of the expression that is specified after the term "return" in the pseudocode return statement. Functions that do not return a value do not contain a return statement. Table 2 provides an example of a function definition for a function that returns the value of a variable valueReturn. + +**Table 2 – Example of a pseudocode table** + +| ExamplePseudocode(valueArgument1, arrayArgument2[ ]) { | Reference | +|--------------------------------------------------------|-----------| +| statement | | +| return valueReturn | | +| } | | + +The pseudocode convention shown in Table 3 is used to indicate an informative comment. + +**Table 3 – Example of a pseudocode comment** + +| ExamplePseudocodeComment() { | Reference | +|---------------------------------------|-----------| +| /* this is a comment start and end */ | | +| } | | + +The pseudocode convention shown in Table 4 specifies repeated execution of a "condition" checking followed by a "statement" until the "condition" is no longer TRUE. + +**Table 4 – Example of a pseudocode while statement** + +| ExamplePseudocodeWhileStatement() { | Reference | +|-------------------------------------|-----------| +| while (condition) | | +| statement | | +| } | | + +The pseudocode convention shown in Table 5 specifies evaluation of an "initial statement" followed by evaluation of a "condition", and when the "condition" is TRUE, it specifies repeated execution of a "primary statement" followed by a "subsequent statement", and repeating the checking of the condition and the execution of the primary statement and subsequent statement until the checked condition no longer evaluates to the value TRUE. + +**Table 5 – Example of a pseudocode for statement** + +| ExamplePseudocodeForStatement() { | Reference | +|----------------------------------------------------------|-----------| +| for (initial statement; condition; subsequent statement) | | +| primary statement | | +| } | | + +The pseudocode convention shown in Table 6 specifies that a "statement" is executed if a "condition" is TRUE, and that an "alternate statement" is otherwise performed. + +**Table 6 – Example of a pseudocode conditional statement** + +| ExamplePseudocodeConditionalStatement() { | Reference | +|-------------------------------------------|-----------| +| if (condition) | | +| statement | | +| else | | +| alternative statement | | +| } | | + +The pseudocode convention shown in Table 7 specifies the initialization of the values of entries in an array. In this example, iArr[0] is set equal to 2, iArr[1] is set equal to 4, iArr[2] is set equal to 6, and iArr[3] is set equal to 8. + +**Table 7 – Example of the initialization of values in an array in pseudocode** + +| ExamplePseudocodeArrayInitialization() { | Reference | +|------------------------------------------|-----------| +| iArr[ ] = {2, 4, 6, 8} | | +| } | | + +### 5.2.8 Mathematical functions + +| | | +|------------|-------------------------------------------------------------------------------------------------------------| +| Ceiling(x) | Ceiling function. Returns the smallest integer that is greater than or equal to the real-valued argument x. | +| Floor(x) | Floor function. Returns the largest integer that is less than or equal to the real-valued argument x. | +| Max(a, b) | Maximum of two arguments as specified in Table 8. | + +**Table 8 – Definition of mathematical function Max( )** + +| Max(a, b) { | Reference | +|--------------------|------------------| +| if (a >= b) | | +| valueReturn = a | | +| else | | +| valueReturn = b | | +| return valueReturn | | +| } | | + +Min(a, b) Minimum of two arguments as specified in Table 9. + +**Table 9 – Definition of mathematical function Min( )** + +| Min(a, b) { | Reference | +|--------------------|------------------| +| if (a <= b) | | +| valueReturn = a | | +| else | | +| valueReturn = b | | +| return valueReturn | | +| } | | + +Abs(x) Absolute value of an argument as specified in Table 10. + +**Table 10 – Definition of mathematical function Abs( )** + +| Abs(x) { | Reference | +|--------------------|------------------| +| if (x >= 0) | | +| valueReturn = x | | +| else | | +| valueReturn = -x | | +| return valueReturn | | +| } | | + +Sign(x) Sign of an argument as specified in Table 11. + +**Table 11 – Definition of mathematical function Sign( )** + +| Sign(x) { | Reference | +|--------------------|------------------| +| if (x >= 0) | | +| valueReturn = 1 | | +| else | | +| valueReturn = -1 | | +| return valueReturn | | +| } | | + +Round(x) Rounding to integer value as specified in Table 12. + +**Table 12 – Definition of mathematical function Round( )** + +| Round(x) { | Reference | +|---------------------------------------------|------------------| +| valueReturn = Sign(x) * Floor(Abs(x) + 0.5) | | +| return valueReturn | | +| } | | + +Clip(x, iLow, iHigh) Clip integer value to a range between integers iLow and iHigh is specified in Table 13. + +**Table 13 – Definition of mathematical function Clip( )** + +| Clip(x, iLow, iHigh) { | Reference | +|---------------------------------------|------------------| +| valueReturn = Max(x, iLow) | | +| valueReturn = Min(valueReturn, iHigh) | | +| return valueReturn | | +| } | | + +ln(x) Natural logarithm of x (the base-e logarithm, where e is the natural logarithm base constant 2.718 281 828...) + +Sqrt(x) Square root of x + +Numones(x) Returns the number of bits in an argument that are set, for a positive integer argument x that is represented in two's complement arithmetic as specified in Table 14. + +**Table 14 – Definition of mathematical function Numones( )** + +| Numones(x) { | Reference | +|------------------------|-----------| +| valueReturn = 0 | | +| while (x != 0) { | | +| valueReturn += (x & 1) | | +| x >>= 1 | | +| } | | +| return valueReturn | | +| } | | + +## 5.3 Syntax and semantics notation + +### 5.3.1 Method of specifying syntax in tabular form + +The syntax tables specify a superset of the syntax of all allowed codestreams. Additional constraints on the syntax may also be specified, either directly or indirectly, in other subclauses. + +Table 15 lists an example of pseudocode used to specify the syntax. When the name of a syntax element appears in the first column, it specifies that the syntax element is parsed from the codestream and the codestream pointer is advanced to the next bit position beyond the syntax element in the codestream parsing process. + +See 5.3.2 for an example of how the semantics of a syntax element are specified in this Specification. + +The column with the heading "Descriptor" specifies the parsing process of an associated syntax element as follows: + +- i(n): two's complement signed integer using n bits, where the MSB is the leftmost bit. This indicates a fixed-length syntax element. The value of n is the size of the syntax element in bits. For example, i(3) indicates a 3-bit syntax element, and i(iVar) indicates a syntax element of length iVar, where iVar is a variable computed from the values of other previously parsed syntax elements. +- u(n): unsigned integer using n bits, where the MSB is the leftmost bit. This indicates a fixed-length syntax element. The value of n is the size of the syntax element in bits. For example, u(3) indicates a 3-bit syntax element, and u(iVar) indicates a syntax element of length iVar, where iVar is a variable computed from the values of other previously parsed syntax elements. +- le(n): unsigned integer using n bits in little-endian form, where n is an integer multiple of 8. This indicates a fixed-length syntax element. The value of n is the size of the syntax element in bits. For example, le(16) indicates a 16-bit syntax element, and le(iVar) indicates a syntax element of length iVar, where iVar is a variable having a value that is an integer multiple of 8 that is computed from the values of other previously parsed syntax elements. +- e(v): entropy coded syntax element where the MSB of the code is the leftmost bit. This indicates a variable-length coded syntax element, and a fixed VLC table is used to parse this syntax element. +- ae(v): adaptive entropy coded syntax element where the MSB of the code is the left most bit. This indicates a variable-length coded syntax element, where the VLC table used to parse the syntax element is selected adaptively based on the values of other previously parsed syntax elements. + +The column with the heading "Reference" provides one or more links to semantics or information about constraints on an associated syntax element. + +**Table 15 – Syntax table example** + +| HEADER_EXAMPLE() { | Descriptor | Reference | +|-----------------------------------------------------------------------------------------------------------------------------|------------|-----------| +| /* A statement can be a syntax element or a conditional statement that specifies the presence and type of syntax element */ | | | +| /* The conditional statements are expressed in terms of the pseudocode operations defined in 5.2.7 */ | | | +| if (condition) | | | +| SYNTAX_ELEMENT_EXAMPLE | u(8) | 5.3.2 | +| } | | | + +### 5.3.2 SYNTAX\_ELEMENT\_EXAMPLE semantics + +SYNTAX\_ELEMENT\_EXAMPLE is an example 8-bit syntax element having semantics and constraints specified in this subclause, as identified in the "Reference" column of Table 15. + +### 5.3.3 Syntax functions + +The codestream is formatted as an ordered sequence of bytes. These bytes contain sequences of bits. The syntax elements appear within a sequence of bits in the order specified in the syntax tables, and for each syntax element, the MSB of the syntax element representation is the first bit in the sequence of bits that represents the syntax element and the LSB of the syntax element representation is the rightmost bit. The bits of the syntax elements shall be extracted from the bytes that represent them by extracting the MSB of the first syntax element from the MSB of the first byte, the next bit of the syntax element from the next less significant bit of the byte, etc., proceeding through to the LSB of the byte and then the MSB of the following byte, if the bit pattern for the syntax element is longer than 8, etc. After the bits of the first syntax element, the same convention shall be followed, starting at the next bit, for the bits of the next syntax element and then for the subsequent syntax elements. + +Unless otherwise specified, the bytes of the codestream are ordered in the sequence of bytes that forms the codestream such that the conceptually first byte is placed first in the sequence of bytes, the second byte is placed second, etc. (i.e., so-called "network" or "big endian" byte ordering is used for the codestream unless otherwise specified). + +The syntax functions IS\_BYTE\_ALIGNED() and POS\_SEEK(iLoc) are used in the specification of some syntax structures. These functions assume the existence of a codestream pointer referring to the position of the next bit to be read from the codestream by the parsing process. Prior to operation of the parsing process, the codestream pointer refers to the position of the first bit of the first byte of the codestream. + +IS\_BYTE\_ALIGNED() is a syntax function specified as follows. + +- If the current position in the codestream is on a byte boundary, i.e., the next bit in the codestream is the first bit in a byte, the return value of IS\_BYTE\_ALIGNED() is equal to TRUE. +- Otherwise, the return value of IS\_BYTE\_ALIGNED() is equal to FALSE. + +POS\_SEEK(iLoc) is a syntax function that sets the codestream pointer to the position of the first bit of the byte, i.e., iLoc bytes from the start of the codestream, where iLoc is a non-negative integer argument, and the first byte of the codestream corresponds to iLoc equal to 0. + +## 5.4 Formatting conventions + +### 5.4.1 Variable and array naming conventions + +Global variables are in scope throughout more than one subclause. The extent of the scope of each global variable is specified in 5.5. The name of a global variable begins with an upper case letter and includes some lower case letters or numerals, and does not include underscore characters, e.g. as in "ImageWidth". With the exception of image variables (5.5.1), all other global variables are associated with a specific image plane; therefore, a separate instance of each global variable exists for the primary image plane and for the alpha image plane (if an alpha image plane is present). + +In the parsing syntax and pseudocode tables of clause 8, the global variable IsCurrPlaneAlphaFlag is used to indicate which set of global variables are referenced in the table; if IsCurrPlaneAlphaFlag is equal to FALSE, the global variables referenced are those of the primary image plane; otherwise (IsCurrPlaneAlphaFlag is equal to TRUE), the global variables referenced are those of the alpha image plane. + +The scope of local variables is limited to one subclause. They begin with a lower case letter and may include some upper case letters or numerals and do not include underscore characters, e.g., iValue. + +Square brackets are used for the indexing of arrays. Arrays can be either syntax elements or variables. A one-dimensional array is referred to as a list. Array indices count from zero. For example, the first element of arrayExample[ ] is arrayExample[0]. + +#### 5.4.2 Data structure naming conventions + +An instance of a data structure is labelled by bold-faced letters. The member variables of a data structure are formatted like global variables. To reference a member variable of a data structure instance, the data structure instance's name is associated with the member variable with a period ".", e.g. **AbslevelIndexDCLum**.TableIndex indicates that the member variable TableIndex is part of the data structure instance **AbslevelIndexDCLum**. + +#### 5.4.3 Syntax element naming conventions + +Syntax elements are labelled by a name in upper case letters, in which at least one underscore character is included. + +#### 5.4.4 Syntax structure naming conventions + +Syntax structure is a term used to refer to a collection of syntax elements. Syntax structures are identified by a name in upper case letters, in which at least one underscore character is included, followed by a pair of parentheses. Within the parentheses, there may be one or more variables. These variables correspond to variables or values that are associated with the pseudocode table for this syntax structure when the syntax structure is invoked within another syntax structure. + +#### 5.4.5 Naming conventions for mnemonic constants + +Mnemonics are used to refer to constant values taken by syntax elements in the parsing and decoding process. Mnemonics constants are in upper case letters without underscores and may include numbers, e.g. YUV420. The mnemonic constants that are used are defined in Table 16. The mnemonic constant RESERVED is used to specify a value that is reserved for future use. + +**Table 16 – Defined mnemonic values** + +| Mnemonics | Syntax element and Reference | +|------------------------------------------------------------------------|----------------------------------------------| +| YUV444, YUV422, YUV420, YONLY, CMYK, CMYKDIRECT, RGB, RGBE, NCOMPONENT | Table 22 for syntax element OUTPUT_CLR_FMT | +| YUV444, YUV422, YUV420, YONLY, YUVK, NCOMPONENT | Table 28 for syntax element INTERNAL_CLR_FMT | +| BD1WHITE1, BD8, BD16, BD16S, BD16F, BD32S, BD5, BD10, BD565, BD1BLACK1 | Table 23 for syntax element OUTPUT_BITDEPTH | +| ALL, NOFLEXBITS, NOHIGHPASS, DCONLY | Table 29 for syntax element BANDS_PRESENT | + +#### 5.4.6 Naming conventions for numerical values + +Integer numbers are expressed as bit patterns, hexadecimal values or decimal numbers. Bit patterns and hexadecimal values have both a numerical value and an associated particular length in bits. + +Hexadecimal notation, indicated by prefixing the hexadecimal number by "0x", may be used instead of binary notation to denote a bit pattern having a length that is an integer multiple of 4. For example, 0x41 represents an eight-bit pattern having only its second most significant bit and its MSB equal to 1. Numerical values that are specified under a "Code" heading in tables that are referred to as "code tables" are bit pattern values (specified as a string of digits equal to 0 or 1 in which the leftmost bit is considered the MSB). Other numerical values not prefixed by "0x" are decimal values. When used in expressions, a hexadecimal value is interpreted as having a value equal to the value of the corresponding bit pattern evaluated as a binary representation of an unsigned integer (i.e., as the value of the number formed by prefixing the bit pattern with a sign bit equal to 0 and interpreting the result as a two's complement representation of an integer value). For example, the hexadecimal value 0xF is equivalent to the 4-bit pattern '1111' and is interpreted in expressions as being equal to the decimal number 15. + +#### 5.4.7 Array dimensions convention + +Arrays of height valHeight and width valWidth are denoted as having dimension valHeight×valWidth. For variable and function names, the character "x" is used as the multiplication symbol. Otherwise, the cross symbol "×" is used to indicate multiplication in all other cases. + +## 5.5 Global variables + +In 5.5, **bold** is used to identify each global variable in the subclause in which it is described. Changes in value applied to global variables persist beyond single pseudocode functions. The scope of that persistence is specified by the subclause in which the global variable is defined. + +### 5.5.1 Image variables + +The following global variables maintain information relevant to the entire image. + +**ExtendedWidth[i]**: This variable specifies the extended image width of component i. + +**ExtendedHeight[i]**: This variable holds the extended image height of component i. + +**IndexOffsetTile[n]**: This variable specifies the offset of the n-th tile packet from the start of the coded image data in bytes. + +**ImagePrimary[i][x][y]**: For each specific triple (i, x, y), where $0 \leq i < \text{NumComponents}$ (subclause 8.4.11), $0 \leq x < \text{ExtendedWidth}[i]$ , $0 \leq y < \text{ExtendedHeight}[i]$ , the associated variable ImagePrimary[i][x][y] holds the image plane sample values associated with the component i, located at the sample position indicated by the values x and y, for the primary image plane. + +**ImageAlpha[i][x][y]**: For each specific triple (i, x, y), where $i = 0$ , $0 \leq x < \text{ExtendedWidth}[i]$ , $0 \leq y < \text{ExtendedHeight}[i]$ , this variable holds the image plane sample value, at the sample position determined by the values x and y, for the alpha image plane. + +**MBHeight**: This variable holds the value associated with the number of vertical macroblock partitions. + +**MBWidth**: This variable holds the value associated with the number of horizontal macroblock partitions. + +**NumTileCols**: This variable holds the value associated with the number of tile partitions in the image horizontally. + +**NumTileRows**: This variable holds the value associated with the number of tile partitions in the image vertically. + +**TopMBIndexOfTile[i]**: This variable holds the value associated with the macroblock index of the top macroblock row of the i-th tile row. + +**LeftMBIndexOfTile[j]**: This variable holds the value associated with the macroblock index of the left macroblock column of the j-th tile column. + +**NumMBInTile[n]**: This variable holds the value associated with the number of macroblocks in the n-th tile. + +**NumBandsOfPrimary**: This variable holds the value associated with the value of NumBands (defined in 5.5.2) for the primary image plane. + +**SubsequentBytes**: This variable holds the value associated with the number of bytes of subsequent data that precede the CODED\_TILES() (8.2.2) syntax element and follow the image plane headers and the tiles index table. + +### 5.5.2 Image plane variables + +The following global variables maintain information relevant for all tiles of the current image plane. + +**IsCurrPlaneAlphaFlag**: This variable is equal to TRUE if the current plane that is being parsed or decoded is the alpha image plane; otherwise, this variable is equal to FALSE. It is also used to specify which set of image plane variables, tile variables, and macroblock variables are being referenced. + +**NumComponents**: This variable holds the value associated with the number of colour components present in the codestream for the current image plane. For the primary image plane, its value can be obtained by calling DetermineNumComponents() (8.4.11). For the alpha image plane, its value is equal to 1. + +**NumBands**: This variable holds the value associated with the number of frequency bands present in the codestream for the current image plane. Its value can be obtained by calling DetermineNumBands() (8.4.4). + +**NumLPQPs**: This variable holds the value associated with the number of lowpass QP sets. This variable may have a constant value over an image plane or it may vary from tile to tile. + +**NumHPQPs**: This variable holds the value associated with the number of highpass QP sets. This variable may have a constant value over an image plane or it may vary from tile to tile. + +**MBQPIndexLP[MBx][MBy]**: (MBx and MBy are defined in 5.5.4) This variable holds the QP index into the table of quantization parameters for LP coefficients, corresponding to the macroblock indexed by MBx and MBy. The same index applies for all colour components. + +**MBQPIndexHP[MBx][MBy]**: (MBx and MBy are defined in 5.5.4) This variable holds the QP index into the table of quantization parameters for highpass (HP) coefficients, corresponding to the macroblock indexed by MBx and MBy. The same index applies for all colour components. + +**MbDCLP[MBx][MBy][i][j]**: (MBx and MBy are defined in 5.5.4) When j is equal to 0, this variable holds the DC transform coefficient for the macroblock indexed by MBx and MBy, associated with the colour component indexed by i. For non-zero values of the index j, this variable holds the j-th LP transform coefficient for the macroblock indexed by MBx and MBy, and associated with the colour component indexed by i. The index j ranges from 0 to 15 for luma components of all colour formats and chroma components of all colour formats except YUV 4:2:0 and YUV 4:2:2. In the YUV 4:2:0 chroma component case, j ranges from 0 to 3, and in the YUV 4:2:2 chroma component case, j ranges from 0 to 7. + +**MBBuffer[MBx][MBy][i][j]**: (MBx and MBy are defined in 5.5.4) This variable holds the j-th transform coefficient associated with the colour component i – for the macroblock indexed by MBx and MBy. The index j ranges from 0 to 255. + +The ordering of the 256 transform coefficients in the macroblock is as follows: let iBlkIndex represent the block index of a 4×4 block of component i in the macroblock, indexed in raster scan order, with iBlkIndex ranging from 0 to 15. Then the 16 transform coefficients for this block (indexed in raster scan order in the block) are represented by the values of MBBuffer[MBx][MBy][i][j], where j ranges from (16\*iBlkIndex + 0) to (16\*iBlkIndex + 15), inclusive. + +**MBCBPHP[MBx][mBy][i]**: (MBx and mBy are defined in 5.5.4) This variable holds the coded block status for the macroblock indexed by MBx and mBy, associated with the colour component indexed by i. The association of a bit of this variable to the block in the macroblock is specified in subclause 8.7.17.1, and a bit takes the value 1 if the corresponding block has non-zero HP transform coefficients to be scanned. + +**PredDCLP[MBx][mBy][i][j]**: (MBx and mBy are defined in 5.5.4) This variable holds the predicted DC and LP coefficient values, for the macroblock indexed by MBx and mBy, associated with the colour component indexed by i; the index j ranges from 0 to 6. The predicted DC value corresponds to index 0. + +**ModelBitsMBHP[MBx][mBy][i]**: (MBx and mBy are defined in 5.5.4) This variable holds the value of the member variable mBits[i], associated with the data structure ModelHP as defined in 5.5.6, for the macroblock indexed by MBx and mBy. The index i ranges from 0 to 1. For each macroblock, two values are stored: one value for the luma component, and one value for the chroma components. + +NOTE – The values ModelBitsMBHP[MBx][mBy][i] are used in the parsing process to communicate the state between the parsing of the syntax structures MB\_HP() and MB\_FLEXBITS(). See Table 83. + +**ImagePlane[i][x][y]**: This variable holds the sample value associated with the colour component i, located at the position indicated by the values x and y, where $0 \leq i < \text{NumComponents}$ , $0 \leq x < \text{ExtendedWidth}[i]$ , $0 \leq y < \text{ExtendedHeight}[i]$ , for the current image plane being decoded. + +### 5.5.3 Tile variables + +The following global variables maintain information that is relevant for all macroblocks in the current tile: + +**TileIndexx**: This variable holds the column index of the current tile. The value of TileIndexx is in the range $0 \leq \text{TileIndexx} < \text{NumTileCols}$ . + +**TileIndexy**: This variable holds the row index of the current tile. The value of TileIndexy is in the range $0 \leq \text{TileIndexy} < \text{NumTileRows}$ . + +**NumMBInCurrentTile**: This variable holds the value associated with the number of macroblocks in the current tile. + +**DCQuantParam[i]**: This variable holds the DC quantization parameter for the colour component i of the current tile. + +**LPQuantParam[i][j]**: This variable holds the LP quantization parameter for the colour component i, and the quantization parameter index j of the current tile. + +**HPQuantParam[i][j]**: This variable holds the HP quantization parameter for the colour component i and the quantization parameter index j of the current tile. + +### 5.5.4 Macroblock variables + +The following global variables hold information relevant for a specific macroblock: + +**MBx**: This variable holds the column index of the current macroblock, with respect to the block indices associated with the macroblock partition of the image. + +**mBy**: This variable holds the row index of the current macroblock, with respect to the block indices associated with the macroblock partition of the image. + +**MBDCMode:** This variable holds the DC coefficient prediction mode for the current macroblock. + +**MBLPMode:** This variable holds the LP coefficient prediction mode for the current macroblock. + +**MBHPMode:** This variable holds the HP coefficient prediction mode for the current macroblock. + +**DCInput[i]:** This variable holds the DC transform coefficient value for each colour component i. + +**LPInput[i][j]:** This variable holds the j-th LP transform coefficient value for each colour component i. + +**HPInputVLC[i][j][k]:** This variable holds the MSBs of the k-th HP transform coefficient value for the j-th block of the macroblock for each colour component i. + +**HPInputFlex[i][j][k]:** This variable holds the LSBs of the k-th HP transform coefficient value for the j-th block of the macroblock for each colour component i. + +**IsMBLeftEdgeofTileFlag:** This variable indicates whether the current macroblock is along the left edge of the tile. It is set equal to TRUE if MBx is equal to LeftMBIndexOfTile[TileIndexx]. Otherwise, it is set equal to FALSE. + +**IsMBTopEdgeofTileFlag:** This variable indicates whether current macroblock is along the top edge of the tile. It is set equal to TRUE if mBy is equal to TopMBIndexOfTile[TileIndexy]. Otherwise, it is set equal to FALSE. + +## 5.5.5 Data structures for adaptive VLC table selection + +### 5.5.5.1 General + +Syntax elements which are parsed using adaptive VLC tables are associated with a set of global state variables. The data structure template **AdaptiveVLC** is used to associate these variables to their respective syntax elements. + +**AdaptiveVLC** data structure template member variables are as follows: + +- **DiscrimVal1:** This variable accumulates statistics about the code table choice, used for adaptively switching to other code tables. +- **DiscrimVal2:** This is a second variable used to accumulate statistics about the code table choice, used for adaptively switching to other code tables. When there are more than two code tables for the parsing of a given syntax element, the associated AdaptiveVLC data structure instance requires two discriminants. +- **TableIndex:** The index selecting which code table is used for the current macroblock. +- **DeltaTableIndex:** The index selecting which Delta Table is used for modifying DiscrimVal1, for the current macroblock. +- **Delta2TableIndex:** The index selecting which Delta Table is used for modifying DiscrimVal2, for the current macroblock. + +The collective term discriminant is used, when referring to either DiscrimVal1 or DiscrimVal2; these two member variables are jointly referred to as the discriminants associated with a specific AdaptiveVLC data structure instance. + +See 5.5.5.2 to 5.5.5.4 for descriptions of instances of the AdaptiveVLC data structure that are used for the parsing of syntax elements associated with DC, LP, and HP transform coefficients. + +NOTE – Informative remarks related to this subclause are provided in D.9. + +### 5.5.5.2 DC adaptiveVLC data structure instances + +**AbslevelIndDCLum:** This data structure instance accumulates statistics for the ABS\_LEVEL\_INDEX syntax element, during parsing of the syntax structure DECODE\_ABS\_LEVEL() (Table 50) from within DECODE\_DC() (Table 49), referring to luma DC values. The corresponding TableIndex chooses between the code tables for the syntax element ABS\_LEVEL\_INDEX, which are specified in 8.7.14.5. + +**AbslevelIndDCChr:** This data structure instance accumulates statistics for the ABS\_LEVEL\_INDEX syntax element, during parsing of the syntax structure DECODE\_ABS\_LEVEL() (Table 50) from within DECODE\_DC() (Table 49), referring to chroma DC values. The corresponding TableIndex chooses between the code tables for the syntax element ABS\_LEVEL\_INDEX, which are specified in 8.7.14.5. + +### 5.5.5.3 Lowpass adaptiveVLC data structure instances + +**DecFirstIndLPLum:** This data structure instance accumulates statistics for the FIRST\_INDEX syntax element, during parsing of the syntax structure DECODE\_FIRST\_INDEX() (Table 75) from within DECODE\_BLOCK() (Table 72), referring to luma LP values. The corresponding TableIndex chooses between the code tables for the syntax element FIRST\_INDEX, which are specified in 8.7.18.9.7. + +**DecIndLPLum0:** This data structure instance accumulates statistics for the INDEX\_A syntax element, during parsing of the syntax structure DECODE\_INDEX() (Table 74) from within DECODE\_BLOCK() (Table 72), referring to luma LP values, with the local variable iContext (local to the pseudocode table for DECODE\_BLOCK()) equal to 0. The corresponding TableIndex chooses between the code tables for the syntax element INDEX\_A, which are specified in 8.7.18.9.4. + +**DecIndLPLum1:** This data structure instance accumulates statistics for the INDEX\_A syntax element, during parsing of the syntax structure DECODE\_INDEX() (Table 74) from within DECODE\_BLOCK() (Table 72), referring to luma LP values, with the local variable iContext (local to the pseudocode table for DECODE\_BLOCK()) equal to 1. The corresponding TableIndex chooses between the code tables for the syntax element INDEX\_A, which are specified in 8.7.18.9.4. + +**DecFirstIndLPChr:** This data structure instance accumulates statistics for the FIRST\_INDEX syntax element, during parsing of the syntax structure DECODE\_FIRST\_INDEX() (Table 75) from within DECODE\_BLOCK() (Table 72), referring to chroma LP values. The corresponding TableIndex chooses between the code tables for the syntax element FIRST\_INDEX, which are specified in 8.7.18.9.7. + +**DecIndLPChr0:** This data structure instance accumulates statistics for the INDEX\_A syntax element, during parsing of the syntax structure DECODE\_INDEX() (Table 74) from within DECODE\_BLOCK() (Table 72), referring to chroma LP values, with the local variable iContext (local to the pseudocode table for DECODE\_BLOCK()) equal to 0. The corresponding TableIndex chooses between the code tables for the syntax element INDEX\_A, which are specified in 8.7.18.9.4. + +**DecIndLPChr1:** This data structure instance accumulates statistics for the INDEX\_A syntax element, during parsing of the syntax structure DECODE\_INDEX() (Table 74) from within DECODE\_BLOCK() (Table 72), referring to chroma LP values, with the local variable iContext (local to the pseudocode table for DECODE\_BLOCK()) equal to 1. The corresponding TableIndex chooses between the code tables for the syntax element INDEX\_A, which are specified in 8.7.18.9.4. + +**AbsLevelIndLP0:** This data structure instance accumulates statistics for the ABS\_LEVEL\_INDEX syntax element, during parsing of the syntax structure DECODE\_ABS\_LEVEL() (Table 50) from within DECODE\_BLOCK() (Table 72), referring to LP values with iContext (local to the pseudocode table for DECODE\_BLOCK()) equal to 0. The corresponding TableIndex chooses between the code tables for the syntax element ABS\_LEVEL\_INDEX, which are specified in 8.7.14.5. + +**AbsLevelIndLP1:** This data structure instance accumulates statistics for the ABS\_LEVEL\_INDEX syntax element, during parsing of the syntax structure DECODE\_ABS\_LEVEL() (Table 50) from within DECODE\_BLOCK() (Table 72), referring to LP values with iContext (local to the pseudocode table for DECODE\_BLOCK()) equal to 1. The corresponding TableIndex chooses between the code tables for the syntax element ABS\_LEVEL\_INDEX, which are specified in 8.7.14.5. + +#### 5.5.5.4 Highpass adaptiveVLC data structure instances + +**DecFirstIndHPLum:** This data structure instance accumulates statistics for the FIRST\_INDEX syntax element, during parsing of the syntax structure DECODE\_FIRST\_INDEX() (Table 75) from within DECODE\_BLOCK() (Table 72), referring to luma HP values. The TableIndex chooses between the code tables for the syntax element FIRST\_INDEX, which are specified in 8.7.18.9.7. + +**DecIndHPLum0:** This data structure instance accumulates statistics for the INDEX\_A syntax element, during parsing of the syntax structure DECODE\_INDEX() (Table 74) from within DECODE\_BLOCK (Table 72), referring to luma HP values, with the local variable iContext (local to the pseudocode table for DECODE\_BLOCK()) equal to 0. The TableIndex chooses between the code tables for the syntax element INDEX\_A, which are specified in 8.7.18.9.4. + +**DecIndHPLum1:** This data structure instance accumulates statistics for the INDEX\_A syntax element, during parsing of the syntax structure DECODE\_INDEX() (Table 74) from within DECODE\_BLOCK() (Table 72), referring to luma HP values, with the local variable iContext (local to the pseudocode table for DECODE\_BLOCK()) equal to 1. The TableIndex chooses between the code tables for the syntax element INDEX\_A, which are specified in 8.7.18.9.4. + +**DecFirstIndHPChr:** This data structure instance accumulates statistics for the FIRST\_INDEX syntax element, during parsing of the syntax structure DECODE\_FIRST\_INDEX() (Table 75) from within DECODE\_BLOCK() (Table 72), referring to chroma HP values. The TableIndex chooses between the code tables for the syntax element FIRST\_INDEX, which are specified in 8.7.18.9.7. + +**DecIndHPChr0:** This data structure instance accumulates statistics for the INDEX\_A syntax element, during parsing of the syntax structure DECODE\_INDEX() (Table 74) from within DECODE\_BLOCK() (Table 72), referring to chroma HP values, with the local variable iContext (local to the pseudocode table for DECODE\_BLOCK()) equal to 0. The TableIndex chooses between the code tables for the syntax element INDEX\_A, which are specified in 8.7.18.9.4. + +**DecIndHPChr1:** This data structure instance accumulates statistics for the INDEX\_A syntax element, during parsing of the syntax structure DECODE\_INDEX() (Table 74) from within DECODE\_BLOCK() (Table 72), referring to chroma HP values, with the local variable iContext (local to the pseudocode table for DECODE\_BLOCK()) equal to 1. The TableIndex chooses between the code tables for the syntax element INDEX\_A, which are specified in 8.7.18.9.4. + +**AbsLevelIndHP0:** This data structure instance accumulates statistics for the ABS\_LEVEL\_INDEX syntax element, during parsing of the syntax structure DECODE\_ABS\_LEVEL() (Table 50) from within DECODE\_BLOCK() (Table 72), referring to HP values with iContext (local to the pseudocode table for DECODE\_BLOCK()) equal to 0. The TableIndex chooses between the code tables for the syntax element ABS\_LEVEL\_INDEX, which are specified in 8.7.14.5. + +**AbsLevelIndHP1:** This data structure instance accumulates statistics for the ABS\_LEVEL\_INDEX syntax element, during parsing of the syntax structure DECODE\_ABS\_LEVEL() (Table 50) from within DECODE\_BLOCK() (Table 72), referring to HP values with iContext (local to the pseudocode table for DECODE\_BLOCK()) equal to 1. The TableIndex chooses between the code tables for the syntax element ABS\_LEVEL\_INDEX. This syntax element's code tables are specified in 8.7.14.5. + +**DecNumCBPHP:** This data structure instance accumulates statistics for the NUM\_CBPHP syntax element, during parsing of the syntax structure MB\_CBPHP() (subclause 8.7.17.2). The TableIndex chooses between the code tables for the syntax element NUM\_CBPHP, which are specified in 8.7.17.4.1. + +**DecNumBlkCBPHP:** This data structure instance accumulates statistics for the NUM\_BLKCBPHP syntax element, during parsing of the syntax structure MB\_CBPHP() (subclause 8.7.17.2). The TableIndex chooses between the code tables for NUM\_BLKCBPHP, which are specified in 8.7.17.4.2. + +NOTE – The number of code tables for the NUM\_BLKCBPHP syntax element is either 5 or 9, depending on the INTERNAL\_CLR\_FMT of the image. + +### 5.5.6 Adaptive coefficient normalization data structure instances + +The parsing of syntax elements associated with transform coefficients involves maintaining state variables that are used for adaptive coefficient normalization. Each frequency band (DC, LP, HP) maintains its own collection of state variables to track these statistics. To denote the association of these variables, a data structure is used. The data structure template **Model** is defined as follows. + +**Model** data structure template member variables: + +- mState[i]: This variable maintains the associated state, where mState[0] represents the information for the luma component, and mState[1] represents the information for the chroma components; +- mBits[i]: This variable represents the number of bits, where mBits[0] represents the information for the luma component, and mBits[1] represents the information for the chroma components. + +The following instances of the **Model** data structure are used for the DC, LP, and HP bands: + +**ModelDC:** This data structure instance maintains the statistics for the DC band; + +**ModelLP:** This data structure instance maintains the statistics for the LP band; + +**ModelHP:** This data structure instance maintains the statistics for the HP band. + +### 5.5.7 Adaptive CBPHP prediction data structure instance + +The CBPHP prediction mechanism is adapted based on the statistics of CBPHP of previous macroblocks. Each colour component maintains its own collection of state variables to track these statistics. To denote the association of these variables, the data structure template **CBPHPModel** is defined as follows. + +**CBPHPModel** has three member variables indexed by i, where i is equal to either 0 or 1. This data structure template holds two independent sets of statistics: one for the luma component, corresponding to i = 0, and one for the chroma components, corresponding to i = 1. The three member variables are as follows: + +- CBPHPState[i]: This variable maintains the state; +- CountOnes[i]: This variable represents the count of blocks, computed as specified in 8.10.2, with the value of coded status (derived from CBPHP) equal to 1; +- CountZeroes[i]: This variable represents the count of blocks, computed as specified in 8.10.2, with the value of coded status equal to 0. + +The following instance of the CBPHPModel data structure is used for the HP band. + +**CBPHPModelHP:** This data structure instance maintains the CBPHP statistics for the HP band. + +### 5.5.8 Adaptive count CBPLP variables + +The following global variables maintain information that is relevant for the parsing of syntax elements associated with CBPLP: + +**CountZeroCBPLP:** This variable holds the sample value associated with a count the number of times the CBPLP is equal to zero; + +**CountMaxCBPLP:** This variable holds the sample value associated with a count the number of times the CBPLP is equal to its maximum (8.9.3). + +### 5.6 Adaptive VLC deltaDisc tables + +The following global variables maintain lists of the appropriate values of deltaDisc when a syntax element is parsed using a VLC having a code table that can be adaptively selected. + +**AbslevelIndexDelta[i][j]:** This variable holds the value associated with the incremental discriminant value for the i-th syntax element and the j-th code table associated with syntax element ABS\_LEVEL\_INDEX (8.7.14.5). + +**FirstIndexDelta[i][j]:** This variable holds the value associated with the incremental discriminant value for the i-th syntax element and the j-th code table associated with syntax element FIRST\_INDEX (8.7.18.9.7). + +**Index1Delta[i][j]:** This variable holds the value associated with the incremental discriminant value for the i-th syntax element and the j-th code table associated with syntax element INDEX\_A (8.7.18.9.4). + +**NumCBPHPDelta[i][j]:** This variable holds the value associated with the incremental discriminant value for the i-th syntax element and the j-th code table associated with syntax element NUM\_CBPHP (8.7.17.4.1). + +**NumBlkCBPHPDelta[i][j]:** This variable holds the value associated with the incremental discriminant value for the i-th syntax element and the j-th code table associated with syntax element NUM\_BLKCBPHP (8.7.17.4.2). + +### 5.7 Adaptive inverse scanning tables + +The following global variables maintain lists of the various coefficient scanning orders and related statistics. + +**LowpassScanOrder[i]:** This variable holds the value associated with the location where the i-th lowpass transform coefficient is put into a block in the raster scan order. + +**HighpassHorScanOrder[i]:** This variable holds the value associated with the location where the i-th highpass transform coefficient is put into a block in the raster scan order with horizontal scanning. + +**HighpassVerScanOrder[i]:** This variable holds the value associated with the location where the i-th highpass transform coefficient is put into a block in the raster scan order with vertical scanning. + +**ScanOrder0[i]:** This variable holds the value associated with the first of two possible initialization values for the lowpass and highpass coefficient scans. + +**ScanOrder1[i]:** This variable holds the value associated with the second of two possible initialization values for the lowpass and highpass coefficient scans. + +**LowpassTotals[i]:** This variable holds the value associated with the statistics used to determine how the lowpass scan order is updated. + +**HighpassHorTotals[i]:** This variable holds the value associated with the statistics used to determine how the highpass horizontal scan order is updated. + +**HighpassVerTotals[i]:** This variable holds the value associated with the statistics used to determine how the highpass vertical scan order is updated. + +**ScanTotals[i]:** This variable holds the value associated with the initialization of the lists used to determine how the lowpass and highpass scan order is updated. + +## 6 Image and codestream structures + +### 6.1 General + +In this clause, *italic* is used to identify all occurrences of terms defined in clause 3. + +6.2 Image planes and component arrays + +An *image* is composed of one or two *image planes*: a *primary image plane*, and, when present, an *alpha image plane*. An *image plane* is an ordered set of *components*. A *component* is an array of samples. The *primary image plane* may have multiple *components*; NumComponents (8.4.11) specifies the number of *components*, with $1 \leq \text{NumComponents} \leq 4111$ . For this *primary image plane*, each *component* is an ExtendedHeight[i] × ExtendedWidth[i] array of samples, where ExtendedWidth[i] and ExtendedHeight[i] specify (respectively) the width and height of the array for the i-th *component*, for the index i, $0 \leq i < \text{NumComponents}$ . + +For both the *primary image plane* and the *alpha image plane*, the *component* corresponding to the index i = 0 is defined to be the *luma component* of the respective *image plane*; in the case where NumComponents is greater than 1, the *components* of the *primary image plane* corresponding to non-zero indices are defined to be the *chroma components* of this *image plane*. + +The *alpha image plane* is an *image plane* that contains exactly one *component*. The dimensions of this *component* are the same as those of the *luma component* of the *primary image plane*. + +NOTE – The purpose of an *alpha image plane* is to indicate a level of blend of the *primary image plane* with relation to the background on which the *image* is being rendered. A common interpretation of the *alpha image plane* is as a multiplicative processing (normalized to between 0 and 1) applied to the sample values of the *primary image plane*. The normalized value of the *alpha image plane* determines the proportion of the blending. The value 0 indicates full transparency and the maximum representable value indicates full opacity. + +ExtendedHeight[0] is referred to as the *extended image height*. It specifies the number of rows in the *luma* array that are processed within the *decoding process*. Its value is set equal to HEIGHT\_MINUS1 + 1 + TOP\_MARGIN + BOTTOM\_MARGIN. + +ExtendedWidth[0] is referred to as the *extended image width*. It specifies the number of columns in the *luma* array that are processed within the *decoding process*. Its value is set equal to WIDTH\_MINUS1 + 1 + LEFT\_MARGIN + RIGHT\_MARGIN. + +The *chroma component* array sizes are specified such that ExtendedHeight[i] is equal to ExtendedHeight[1] and ExtendedWidth[i] is equal to ExtendedWidth[1] for all i > 1. The values of ExtendedHeight[1] and ExtendedWidth[1] are specified in Table 17. + +Table 17 – Pseudocode to calculate chroma component array sizes + +| CalculateChromaComponentArraySizes() { | Reference | +|-------------------------------------------|-----------| +| if (INTERNAL_CLR_FMT == YUV420) { | | +| ExtendedHeight[1] = ExtendedHeight[0] / 2 | | +| ExtendedWidth[1] = ExtendedWidth[0] / 2 | | +| } else if (INTERNAL_CLR_FMT == YUV422) { | | +| ExtendedHeight[1] = ExtendedHeight[0] | | +| ExtendedWidth[1] = ExtendedWidth[0] / 2 | | +| } else { | | +| ExtendedHeight[1] = ExtendedHeight[0] | | +| ExtendedWidth[1] = ExtendedWidth[0] | | +| } | | +| } | | + +6.3 Image windowing + +*Image windowing* is specified by four syntax elements: TOP\_MARGIN, BOTTOM\_MARGIN, RIGHT\_MARGIN, and LEFT\_MARGIN. These syntax elements determine the columns and rows of the *extended image* that are not present in the output *image*. With respect to a *raster scan ordering* in the *luma* array of an *image plane*, the first TOP\_MARGIN rows are not output, nor are the last BOTTOM\_MARGIN rows; also, the first LEFT\_MARGIN columns are not output, nor are the last RIGHT\_MARGIN columns of the *luma component*. Similarly, the *spatially co-located* portions of the *chroma components* are not output, in a manner that retains the ratios between the sizes of the arrays for the *chroma components* and that of the *luma component*, as specified in 6.2. + +6.4 Image partitioning + +The *luma component* is partitioned horizontally and vertically into an integer number of 16×16 *blocks* of samples. Label these *blocks* arrayLumaMB[j][k], where $0 \leq j < (\text{ExtendedWidth}[0] / 16)$ and $0 \leq k < (\text{ExtendedHeight}[0] / 16)$ are the *block indices* defined by this partitioning. MBHeight is defined to be equal to ExtendedHeight[0] / 16, and MBWidth is defined to be equal to ExtendedWidth[0] / 16. + +In a similar fashion, the *chroma components* are partitioned into *blocks* arrayChromaMB[i][j][k] of size 8×8 for 4:2:0 sampling, of size 16×8 for 4:2:2 sampling or of size 16×16 in the default case. + +This partitioning of the *components* into *blocks* is called a *macroblock partition*. + +For each specific pair of indices (j, k), the *macroblock* arrayMB[j][k] is defined to be the collection of *blocks* arrayComponenentMB[i][j][k], for $0 \leq i < \text{NumComponents}$ . Across all *components* (all values of i), arrayComponenent[i][j][k] and arrayChromaMB[i][j][k] are *spatially co-located*. + +Let $0 = \text{LeftMBIndexOfTile}[0] < \text{LeftMBIndexOfTile}[1] < \dots < \text{LeftMBIndexOfTile}[\text{NumTileCols}] = \text{MBWidth}$ , and $0 = \text{TopMBIndexOfTile}[0] < \text{TopMBIndexOfTile}[1] < \dots < \text{TopMBIndexOfTile}[\text{NumTileRows}] = \text{MBHeight}$ be two increasing sequences of integers, where the sequences are of length NumTileCols + 1 and NumTileRows + 1, respectively. LeftMBIndexOfTile[ ] is calculated by calling DetermineLeftBoundaryofTile( ) (8.3.25) and TopMBIndexOfTile[ ] is calculated by calling DetermineTopBoundaryofTile( ) (8.3.26). Associated with any such pair of sequences, a *tile partition* may be defined: partition the *macroblocks* of each into *tiles* arrayTile[m][n], for $0 \leq m < \text{NumTileCols}$ , and $0 \leq n < \text{NumTileRows}$ , where arrayTile[m][n] is defined to be the set of all *macroblocks* MB[j][k] $\text{LeftMBIndexOfTile}[m] \leq j < \text{LeftMBIndexOfTile}[m+1]$ and $\text{TopMBIndexOfTile}[n] \leq k < \text{TopMBIndexOfTile}[n+1]$ . + +The i-th *tile column* corresponds to the set of all *tiles* of the form arrayTile[i][n], for $0 \leq n < \text{NumTileRows}$ ; similarly, the j-th *tile row* corresponds to the set of all *tiles* arrayTile[m][j], for $0 \leq m < \text{NumTileCols}$ . The i-th *tile width* is defined to be $\text{LeftMBIndexOfTile}[i+1] - \text{LeftMBIndexOfTile}[i]$ ; likewise, the i-th *tile height* is defined to be $\text{TopMBIndexOfTile}[i+1] - \text{TopMBIndexOfTile}[i]$ . Both the *tile width* and the *tile height* correspond to an integer number of *macroblocks*. The *codestream* specifies a *tile partition* for the *image*, which impacts the order of the parsing of sample values associated with the *image*, as specified in the *codestream* parsing and *decoding processes*. The *tile partition* shall satisfy $1 \leq \text{NumTileCols} \leq 4096$ , and $1 \leq \text{NumTileRows} \leq 4096$ . + +NOTE – Figure 1 provides an informative overview of the *image plane* partitions and implicit *windowing* where; a) the *extended image plane* dimension is indicated by a bold rectangle; b) the output *image plane* edges on left and bottom are indicated by dashed lines); c) 2×4 regular tiling pattern is shown; d) a *macroblock* in tile (1,2) is shown; and e) *blocks* within the *macroblock* are shown in an expanded window. Colour *components* are not explicitly shown. + +![Figure 1: Informative overview of image partitions and internal windowing. The diagram shows a 2x4 grid of tiles. A bold rectangle represents the extended image plane. Dashed lines indicate the output image plane edges. A macroblock is shown within one tile, and its internal blocks are shown in an expanded window.](a5184899f915014fa38608754efcc9c7_img.jpg) + +The diagram illustrates the hierarchical partitioning of an image. At the top, a 2x4 grid of tiles is shown. A bold rectangle outlines the 'Internal image' plane. Dashed lines indicate the 'Output image' plane edges. A 'Macroblock' is highlighted within one of the tiles. Below the macroblock, an expanded window shows the internal 'Blocks' within the macroblock. + +Figure 1: Informative overview of image partitions and internal windowing. The diagram shows a 2x4 grid of tiles. A bold rectangle represents the extended image plane. Dashed lines indicate the output image plane edges. A macroblock is shown within one tile, and its internal blocks are shown in an expanded window. + +T.832(12)\_F01 + +**Figure 1 – Informative overview of image partitions and internal windowing** + +## 6.5 Transform coefficients and frequency bands + +The *decoding process* includes an inverse transform operation. The *transform coefficients* associated with each *component* and each *macroblock* are split into three subsets or *frequency bands*, which are called the *DC coefficient*, the *lowpass coefficients*, and the *highpass coefficients*. + +For each colour *component* of the *macroblock*, one of the following three conditions holds. + +- If the *component* is a *luma component* or a *chroma component* with no down sampling, the following is true. The *component* contains 256 *transform coefficients* for each *macroblock*. These 256 *transform coefficients* are partitioned into three subsets. One set is of size 1, and this coefficient constitutes the *DC coefficient* of this *component*. Another set is of size 15; this set constitutes the *lowpass coefficients*. The third set is of size 240, and constitutes the *highpass coefficients*. +- If the *component* is a *chroma component* with a sampling rate of $\frac{1}{2}$ for both the horizontal and vertical directions, the following holds true. The *component* contains 64 *transform coefficients* for each *macroblock*. These 64 *transform coefficients* are partitioned into three subsets. One set is of size 1, and this coefficient constitutes the *DC coefficient* of this *component*. Another set is of size 3; this set constitutes the *lowpass coefficients*. The third set is of size 60, and constitutes the *highpass coefficients*. +- If the *component* is a *chroma component* with a sampling rate of $\frac{1}{2}$ for the horizontal direction and a sampling rate of 1 for the vertical direction, the following holds true. The *component* contains 128 *transform coefficients* for each *macroblock*. These 128 *transform coefficients* are partitioned into three subsets. One set is of size 1, and this coefficient constitutes the *DC coefficient* of this *component*. Another set is of size 7; this set constitutes the *lowpass coefficients*. The third set is of size 120, and constitutes the *highpass coefficients*. + +NOTE 1 – The partitioning of *transform coefficients* into three sets, and the use of the terms DC, lowpass, and highpass is based on the hierarchical nature of the transform. + +*Transform coefficients* are dynamically partitioned into a *VLC-coded part* and a *fixed-length coded part*. The *fixed-length coded part* of the DC and lowpass coefficient is called *FLC refinement*. + +The *fixed-length coded part* of the highpass coefficient is called *flexbits*. *Flexbits* can be carried in a separate *tile packet* as specified in 6.6. + +NOTE 2 – This partition of *transform coefficients* is designed to control the number of bits used to represent the *VLC-coded part*. + +## 6.6 Codestream structure + +A *codestream* is laid out in one of two orderings called the *spatial mode* and the *frequency mode*. In both modes, the *codestream* is laid out as a header, followed by a sequence of *tile packets*. + +NOTE – Figure 2 provides an informative overview of the *codestream* structure for the *spatial mode* and the *frequency mode*. The fact that *tiles* can be out of order, and the fact that there can be *codestream* segments of unspecified content between the *tiles* is not shown in Figure 2. + +![Figure 2: Informative overview of codestream structure. The diagram shows a sequence of components: IMG_HDR, INDEXTBL, TILE1, TILE2, and an ellipsis. Dashed lines connect TILE1 and TILE2 to two detailed views. The 'Spatial mode' view shows a sequence of macroblocks MB_1, MB_2, MB_3, and an ellipsis. The 'Frequency mode' view shows a sequence of coefficients: DC, LOWPASS, HIGHPASS, and FLEXBITS. A reference T.832(12)_F02 is noted at the bottom right.](9edb407536d4d4d4a6ac391527af047c_img.jpg) + +``` + +graph LR + subgraph Header + IMG_HDR[IMG_HDR] + INDEXTBL[INDEXTBL] + end + subgraph Tiles + TILE1[TILE1] + TILE2[TILE2] + Ellipsis1[...] + end + subgraph Spatial_Mode [Spatial mode] + MB_1[MB_1] + MB_2[MB_2] + MB_3[MB_3] + Ellipsis2[...] + end + subgraph Frequency_Mode [Frequency mode] + DC[DC] + LOWPASS[LOWPASS] + HIGHPASS[HIGHPASS] + FLEXBITS[FLEXBITS] + end + Ellipsis3[T.832(12)_F02] + + TILE1 -.-> Spatial_Mode + TILE1 -.-> Frequency_Mode + TILE2 -.-> Frequency_Mode + +``` + +Figure 2: Informative overview of codestream structure. The diagram shows a sequence of components: IMG\_HDR, INDEXTBL, TILE1, TILE2, and an ellipsis. Dashed lines connect TILE1 and TILE2 to two detailed views. The 'Spatial mode' view shows a sequence of macroblocks MB\_1, MB\_2, MB\_3, and an ellipsis. The 'Frequency mode' view shows a sequence of coefficients: DC, LOWPASS, HIGHPASS, and FLEXBITS. A reference T.832(12)\_F02 is noted at the bottom right. + +**Figure 2 – Informative overview of codestream structure. Image header is followed by a sequence of tiles which are in spatial or frequency mode** + +In the *spatial mode*, a single *tile packet* carries the *codestream* of each *tile* in *macroblock* raster scan order (scanning left to right, top to bottom). The bits associated with each *macroblock* are located together. + +In the *frequency mode*, the *codestream* of each *tile* is carried in multiple *tile packets*, where each *tile packet* carries *transform coefficients* of one *frequency band* of that *tile*. The DC *tile packet* carries information of the DC value of each *macroblock*, in *raster scan order*. The LP *tile packet* carries information of the LP coefficients value of each *macroblock*. + +The HP *tile packet* carries information of the *VLC*-coded part of the HP coefficients of each *macroblock*. Finally, the *flexbits tile packet* carries information regarding the low order bits of the HP coefficients. + +## 6.7 Precision and word length + +This subclause is informative: It is not an integral part of this Specification. + +The SCALED\_FLAG syntax element specifies whether scaling is performed in the output formatting stage. If SCALED\_FLAG is equal to TRUE, the final output is divided by 8 in the output formatting stage and thus the effective precision of the *decoding processes* such as the inverse transform is higher. If SCALED\_FLAG is equal to FALSE, there is no such division operation on the final output and the effective prevision of the *decoding processes* of the inverse transform is lower. + +NOTE – Encoding with SCALED\_FLAG equal to TRUE typically improves rate-distortion performance for lossy coding. + +## 7 Overview of decoder + +This clause is informative: it is not an integral part of this Specification. + +### 7.1 General + +A block diagram of the decoder, comprising of the parsing process and decoding process, is shown in Figure 3. + +![Figure 3: Informative decoding process block diagram. The diagram shows the flow from the parsing process to the decoding process, which includes sample reconstruction and output formatting.](9dc9f41d7d76c1add4b190d348cb1533_img.jpg) + +``` + +graph LR + subgraph Parsing_process [Parsing process] + A[Image layer and tile layer parsing] --> B[MB layer and coefficient parsing and inverse coefficient scanning] + B --> C[Adaptation of VLC table selection and models] + end + + subgraph Decoding_process [Decoding process] + C --> D[Coefficient remapping] + D --> E[Coefficient prediction] + E --> F[Dequantization] + + subgraph Sample_reconstruction [Sample reconstruction] + F --> G[First-level inverse transform] + G --> H[First-level overlap filtering] + H --> I[Second-level inverse transform] + I --> J[Second-level overlap filtering] + end + + J --> K[Output formatting] + end + + C --> D + F --> G + K --> L[T832(12)_F03] + +``` + +The diagram illustrates the decoding process. It starts with the **Parsing process**, which includes three steps: **Image layer and tile layer parsing**, **MB layer and coefficient parsing and inverse coefficient scanning**, and **Adaptation of VLC table selection and models**. The output of the parsing process feeds into the **Decoding process**. The decoding process consists of **Coefficient remapping**, **Coefficient prediction**, and **Dequantization**. The output of dequantization enters the **Sample reconstruction** stage, which is enclosed in a dashed box. This stage includes **First-level inverse transform**, **First-level overlap filtering**, **Second-level inverse transform**, and **Second-level overlap filtering**. The final output of the sample reconstruction stage is **Output formatting**. A reference code **T832(12)\_F03** is located at the bottom right of the diagram. + +Figure 3: Informative decoding process block diagram. The diagram shows the flow from the parsing process to the decoding process, which includes sample reconstruction and output formatting. + +**Figure 3 – Informative decoding process block diagram** + +The parsing process consists of the following stages: + +- 1) image layer and tile layer codestream parsing; +- 2) macroblock layer codestream parsing which includes parsing the transform coefficients and inverse scanning; +- 3) adaptation of VLC table selection and context models. + +The decoding process consists of the following stages: + +- 4) coefficient remapping; +- 5) coefficient prediction; +- 6) dequantization; +- 7) sample reconstruction, which consists of the following stages: + +- a) first level inverse transform, + - b) when indicated, a first level overlap filter, + - c) second level inverse transform, + - d) when indicated, a second level overlap filter: +- 8) output formatting. + +Clause 8 specifies the stages in the parsing processes. An overview of these steps is provided in 7.2. + +Clause 9 specifies the stages in the decoding processes. An overview of these processes is provided in 7.3. + +## **7.2 Overview of parsing process** + +### **7.2.1 Overview of image layer codestream parsing** + +The image level codestream structure is specified in 8.2. It consists of the image header, the header of the primary image plane, and, when present, the header of the alpha image plane. The syntax of the image header is specified in 8.3. + +The image plane header defines information that is unique to that plane, and its syntax is specified in 8.4. + +The tile index table is used to locate the data that corresponds to a particular tile. The syntax of tile index table is specified in 8.5. + +### **7.2.2 Overview of tile layer codestream parsing** + +The syntax of the tile layer is specified in 8.7. A tile-packet consists of a tile-packet header, followed by compressed data associated with macroblocks of the tile. + +In spatial mode, all the compressed data pertinent to a macroblock is located together in a single tile-packet and the parsing of syntax elements for a spatial-mode tile is specified in 8.7.2. + +In frequency mode, each tile packet contains the data associated with a particular transform band; in this mode, a tile-packet is classified as a DC tile-packet, an LP tile-packet, a HP tile-packet or a flexbits tile-packet. + +The syntax elements contained in the DC tile-packet, LP tile-packet, HP tile-packet and flexbits tile-packet are specified in 8.7.3, 8.7.5, 8.7.7, and 8.7.9, respectively. + +If the quantization parameters associated with each band are not specified at the image plane header; they are specified at the tile level. + +### **7.2.3 Overview of macroblock layer codestream parsing** + +The macroblock layer is parsed to generate the coefficients of the different frequency bands. These coefficients are inverse transformed to reconstruct the macroblock. + +See 8.7.11 for the specification of the syntax structure MB\_DC( ), which parses the syntax elements related to the DC coefficient, for each component. + +See 8.7.16.1 for the specification of the syntax structure MB\_LP( ), which parses the syntax elements related to the lowpass coefficients for each component and also performs inverse scanning of the coefficients. + +The first step in decoding the HP coefficients involves derivation of CBPHP, which determines which 4×4 blocks of the macroblock have non-zero coefficients. The CBPHP is parsed as specified by the function MB\_CBPHP in 8.7.17.2. See 8.7.18.2 for the specification of the syntax structure MB\_HP( ), which parses the syntax elements for parsing the VLC part of the HP coefficients, and also performs the inverse scanning of the coefficients. The process of parsing syntax elements related to Flexbits and thus refine the HP coefficients is specified in 8.7.19.1. + +The VLC table used to parse the syntax elements can be adapted based on the value of previously parsed syntax elements. The adaptation processes for VLC table selection and other context models are also specified in pseudocode in these subclauses. + +## **7.3 Overview of the decoding process** + +### **7.3.1 Overview of coefficient mapping** + +The DC, LP and HP transform coefficients are remapped, and this remapping process is specified in 9.5. + +### **7.3.2 Overview of coefficient prediction** + +The transform coefficient may be predicted from the coefficients of the neighbouring blocks and macroblocks, and this prediction process is specified in 9.6. + +### **7.3.3 Overview of dequantization** + +The dequantization process specifies how the transform coefficients are scaled by the quantizer parameter, and this process is specified in 9.8. The derivation of the quantization parameter is specified in 9.7. + +### **7.3.4 Overview of sample reconstruction** + +See 9.9 for a specification of the sample reconstruction process. + +The inverse transform takes a two-level lapped transform. The steps are as follows. + +- An inverse core transform (ICT) is applied to each $4\times 4$ block corresponding to reconstructed DC and LP coefficients arranged in an array known as the DC-LP array. The first level inverse transform process is specified in 9.9.2. +- An overlap filter operation, when indicated, is applied to $4\times 4$ areas evenly straddling blocks in the DC-LP array. For images with soft tiles, this filter is applied to all such blocks. For images with hard tiles, this filter is applied only to the interior of tiles. Furthermore, an overlap filter is applied to boundary $2\times 4$ and $4\times 2$ areas, as well as the four $2\times 2$ corner areas. For images with hard tiles, these filters are additionally applied at tile boundaries. The first level overlap filtering process is specified in 9.9.3. For INTERNAL\_CLR\_FMT equal to YUV420 or YUV422, alternate filter operations are applied to the $2\times 2$ interior blocks and $2\times 1$ and $1\times 2$ edge blocks of the chroma components. For these cases, a prediction process is used for the corner samples, denoted 'OverlapPostFilter1' in Figure 4 and detailed in Table 154 and Table 155. +- The resulting array contains coefficients of the $4\times 4$ blocks corresponding to the first level transform. These coefficients are combined with the reconstructed HP coefficients into a larger array. This coefficient combination process is specified in 9.9.4. +- An ICT is applied to each $4\times 4$ block. The second level inverse transform process is specified in 9.9.5. +- An overlap filter operation, when indicated, is applied to $4\times 4$ areas evenly straddling blocks in the DC-LP array. For images with soft tiles, this filter is applied to all such blocks. For images with hard tiles, this filter is applied only to the interior of tiles. Furthermore, an overlap filter is applied to boundary $2\times 4$ and $4\times 2$ areas, as well as the four $2\times 2$ corner areas. For images with hard tiles, these filters are additionally applied at tile boundaries. The second level overlap filtering process is specified in 9.9.6. + +The flow chart for the sample reconstruction process is shown in Figure 4. + +![Flowchart of sample reconstruction process showing First level and Second level steps.](12c19090355e19922e23044633b9d1ea_img.jpg) + +The flowchart illustrates the sample reconstruction process, divided into a First level and a Second level. A vertical dashed line separates the two levels. + +**First level:** + +- Starts with a decision diamond: "422 U or V?". + - If "Yes", it proceeds to "T2pt". + - If "No", it proceeds to another decision diamond: "420 U or V?". +- From "420 U or V?": + - If "Yes", it proceeds to "T2x2h". + - If "No", it proceeds to "ICT4x4". +- From "T2x2h", it proceeds to a decision diamond: "OVERLAP == 2?". + - If "Yes", it proceeds to "Corner?". + - If "No", it proceeds to "Boundary?". +- From "Corner?": + - If "Yes", it proceeds to "OverlapPost Filter1". + - If "No", it proceeds to "Boundary?". +- From "Boundary?": + - If "Yes", it proceeds to "OverlapPost Filter2". + - If "No", it proceeds to "OverlapPost Filter2x2". +- From "ICT4x4", it proceeds to a decision diamond: "OVERLAP == 2?". + - If "Yes", it proceeds to "Corner?". + - If "No", it proceeds to "Boundary?". +- From "Corner?": + - If "Yes", it proceeds to "OverlapPost Filter4". + - If "No", it proceeds to "Boundary?". +- From "Boundary?": + - If "Yes", it proceeds to "OverlapPost Filter4". + - If "No", it proceeds to "OverlapPost Filter4x4". + +**Second level:** + +- Starts with "ICT4x4" (receiving input from the First level). + - Proceeds to a decision diamond: "OVERLAP == 1 or 2?". +- From "OVERLAP == 1 or 2?": + - If "Yes", it proceeds to "Corner?". + - If "No", it proceeds to "Boundary?". +- From "Corner?": + - If "Yes", it proceeds to "OverlapPost Filter4". + - If "No", it proceeds to "Boundary?". +- From "Boundary?": + - If "Yes", it proceeds to "OverlapPost Filter4". + - If "No", it proceeds to "OverlapPost Filter4x4". + +The flowchart concludes with a final output path from the "OverlapPost Filter4x4" blocks in both levels. + +T832(12)\_F04 + +Flowchart of sample reconstruction process showing First level and Second level steps. + +Figure 4 – Informative overview of sample reconstruction process + +### 7.3.5 Overview of output formatting + +See 9.10 for a specification of the outputting process that accounts for the various transformations required to handle the different colour formats and bit depths. + +## 8 Syntax, semantics, and parsing process + +### 8.1 General + +This clause specifies the codestream layout and the processes related to parsing syntax elements from the codestream. The parsing of syntax elements requires information about the order of syntax elements as they occur in the codestream, along with the manner of correctly interpreting these syntax elements. At a given point in the parsing of the codestream, the order and presence of syntax elements is conditional upon the state of the decoder itself at that time (based on the previously parsed and interpreted syntax elements as specified by the pseudocode of this subclause). + +This clause also specifies the adaptation processes that are associated with variable-length decoding, and with adaptive coefficient normalization. These adaptation processes require specific state variables to be maintained by the decoder in order to properly parse the syntax elements of the codestream. Therefore, the processes of initializing and updating these state variables are also specified in this clause. + +The codestream is comprised of the following layers: image; tile; macroblock; and block. Furthermore, the macroblock and block layers are laid out differently for the spatial and frequency modes of the codestream. The parsing processes of + +this subclause are organized by this hierarchy. Below the macroblock level, the parsing processes are further grouped by frequency band; separate syntax structures specify the decoding of the DC, LP and HP frequency bands. + +## 8.2 CODED\_IMAGE() + +### 8.2.1 Syntax structure + +The CODED\_IMAGE() syntax structure is specified in Table 18. + +NOTE – Throughout the parsing of syntax elements, it is assumed that, if ALPHA\_IMAGE\_PLANE\_FLAG is equal to TRUE, there are two sets of parsed syntax elements: one set corresponding to the primary image plane and used if IsCurrPlaneAlphaFlag is equal to FALSE, and one set corresponding to the alpha image plane and used if IsCurrPlaneAlphaFlag is equal to TRUE. + +**Table 18 – CODED\_IMAGE() syntax structure** + +| CODED_IMAGE() { | Descriptor | Reference | +|-----------------------------------------------------------|-------------------|------------------| +| IMAGE_HEADER( ) | | 8.3 | +| IsCurrPlaneAlphaFlag = FALSE | | | +| IMAGE_PLANE_HEADER( ) | | 8.4 | +| if (ALPHA_IMAGE_PLANE_FLAG) { | | | +| IsCurrPlaneAlphaFlag = TRUE | | | +| IMAGE_PLANE_HEADER( ) | | 8.4 | +| } | | | +| if (INDEX_TABLE_PRESENT_FLAG) | | | +| INDEX_TABLE_TILES( ) | | 8.5 | +| SubsequentBytes = VLW_ESC( ) | | 8.2.4 | +| if (SubsequentBytes > 0) { | | | +| iBytes = PROFILE_LEVEL_INFO( ) | | 8.6 | +| valueAdditionalBytes = SubsequentBytes – iBytes | | | +| for (iBytes = 0; iBytes < valueAdditionalBytes; iBytes++) | | | +| RESERVED_A_BYTE | u(8) | 8.2.3 | +| } | | | +| CODED_TILES( ) | | 8.7 | +| } | | | + +### 8.2.2 SubsequentBytes + +SubsequentBytes specifies the number of bytes of subsequent data that precede the CODED\_TILES( ). The value of this variable is determined by a VLW\_ESC( ) syntax structure as specified in 8.2.4. When SubsequentBytes is not equal to 0, it is a requirement of codestream conformance that SubsequentBytes shall not be less than 4. + +The value of the variable valueAdditionalBytes is derived from the value of SubsequentBytes as shown in Table 18. + +The value of valueAdditionalBytes shall be equal to 0 in codestreams encoded according to this version of this Specification. The use of other values of valueAdditionalBytes is reserved for future specification by ITU-T | ISO/IEC. Decoders shall allow this variable to have any value and shall use this value to determine the quantity of RESERVED\_A\_BYTE syntax elements that follow. + +NOTE – The purpose of the specification for decoders to allow this variable to have any value is to enable the future definition of a backward-compatible usage of different values of this variable. + +### 8.2.3 RESERVED\_A\_BYTE + +RESERVED\_A\_BYTE is an 8-bit syntax element. The use of this syntax element is reserved for future specification by ITU-T | ISO/IEC. When present, the value of this syntax element shall be ignored by the decoder. + +NOTE – The purpose of the specification for decoders to ignore the value of RESERVED\_A\_BYTE is to enable the future definition of a backward-compatible usage of this syntax element. + +## 8.2.4 VLW\_ESC() + +### 8.2.4.1 Syntax structure + +The VLW\_ESC() syntax structure is specified in Table 19. + +**Table 19 – VLW\_ESC() syntax structure** + +| VLW_ESC() { | Descriptor | Reference | +|---------------------------------------------------|-------------------|------------------| +| FIRST_BYTE | u(8) | 8.2.4.2 | +| if (FIRST_BYTE < 0xFB) { | | | +| SECOND_BYTE | u(8) | 8.2.4.3 | +| iValue = FIRST_BYTE * 256 + SECOND_BYTE | | | +| } else if (FIRST_BYTE == 0xFB) { | | | +| FOUR_BYTES | u(32) | 8.2.4.4 | +| iValue = FOUR_BYTES | | | +| } else if (FIRST_BYTE == 0xFC) { | | | +| EIGHT_BYTES | u(64) | 8.2.4.5 | +| iValue = EIGHT_BYTES | | | +| } else /* FIRST_BYTE is 0xFD, or 0xFE, or 0xFF */ | | | +| iValue = 0 /* Escape Mode */ | | | +| return iValue | | | +| } | | | + +#### 8.2.4.2 FIRST\_BYTE + +FIRST\_BYTE is an 8-bit syntax element that affects the computation of iValue as specified in 8.2.4.1. + +#### 8.2.4.3 SECOND\_BYTE + +SECOND\_BYTE is an 8-bit syntax element that affects the computation of iValue as specified in 8.2.4.1. + +#### 8.2.4.4 FOUR\_BYTES + +FOUR\_BYTES is a 32-bit syntax element that affects the computation of iValue as specified in 8.2.4.1. + +#### 8.2.4.5 EIGHT\_BYTES + +EIGHT\_BYTES is a 64-bit syntax element that affects the computation of iValue as specified in 8.2.4.1. + +## 8.3 IMAGE\_HEADER() + +### 8.3.1 Syntax structure + +The IMAGE\_HEADER() syntax structure is specified in Table 20. + +**Table 20 – IMAGE\_HEADER() syntax structure** + +| IMAGE_HEADER() { | Descriptor | Reference | +|--------------------------------------------|------------|-----------| +| GDI_SIGNATURE | u(64) | 8.3.2 | +| RESERVED_B | u(4) | 8.3.3 | +| HARD_TILING_FLAG | u(1) | 8.3.4 | +| RESERVED_C | u(3) | 8.3.5 | +| TILING_FLAG | u(1) | 8.3.6 | +| FREQUENCY_MODE_CODESTREAM_FLAG | u(1) | 8.3.7 | +| SPATIAL_XFRM_SUBORDINATE | u(3) | 8.3.8 | +| INDEX_TABLE_PRESENT_FLAG | u(1) | 8.3.9 | +| OVERLAP_MODE | u(2) | 8.3.10 | +| SHORT_HEADER_FLAG | u(1) | 8.3.11 | +| LONG_WORD_FLAG | u(1) | 8.3.12 | +| WINDOWING_FLAG | u(1) | 8.3.13 | +| TRIM_FLEXBITS_FLAG | u(1) | 8.3.14 | +| RESERVED_D | u(1) | 8.3.15 | +| RED_BLUE_NOT_SWAPPED_FLAG | u(1) | 8.3.16 | +| PREMULTIPLIED_ALPHA_FLAG | u(1) | 8.3.17 | +| ALPHA_IMAGE_PLANE_FLAG | u(1) | 8.3.18 | +| OUTPUT_CLR_FMT | u(4) | 8.3.19 | +| OUTPUT_BITDEPTH | u(4) | 8.3.20 | +| if (SHORT_HEADER_FLAG) { | | | +| WIDTH_MINUS1 | u(16) | 8.3.21 | +| HEIGHT_MINUS1 | u(16) | 8.3.22 | +| } else { | | | +| WIDTH_MINUS1 | u(32) | 8.3.21 | +| HEIGHT_MINUS1 | u(32) | 8.3.22 | +| } | | | +| if (TILING_FLAG) { | | | +| NUM_VER_TILES_MINUS1 | u(12) | 8.3.23 | +| NUM_HOR_TILES_MINUS1 | u(12) | 8.3.24 | +| } | | | +| for (n = 0; n < NUM_VER_TILES_MINUS1; n++) | | | +| if (SHORT_HEADER_FLAG) | | | +| TILE_WIDTH_IN_MB[n] | u(8) | 8.3.25 | +| else | | | +| TILE_WIDTH_IN_MB[n] | u(16) | 8.3.25 | +| for (n = 0; n < NUM_HOR_TILES_MINUS1; n++) | | | +| if (SHORT_HEADER_FLAG) | | | +| TILE_HEIGHT_IN_MB[n] | u(8) | 8.3.26 | +| else | | | +| TILE_HEIGHT_IN_MB[n] | u(16) | 8.3.26 | +| if (WINDOWING_FLAG) { | | | +| TOP_MARGIN | u(6) | 8.3.27 | +| LEFT_MARGIN | u(6) | 8.3.28 | +| BOTTOM_MARGIN | u(6) | 8.3.29 | +| RIGHT_MARGIN | u(6) | 8.3.30 | +| } | | | +| } | | | + +### 8.3.2 GDI\_SIGNATURE + +GDI\_SIGNATURE is a 64-bit syntax element that identifies the codestream. It shall have the value 0x574D50484F544F00. + +NOTE – This signature corresponds to "WMPHOTO" using the UTF-8 character set encoding specified in Annex D of ISO/IEC 10646, followed by a byte equal to 0. + +### 8.3.3 RESERVED\_B + +RESERVED\_B is a 4-bit syntax element that shall be equal to 1 in all codestreams conforming to this version of this Specification. All other values are reserved. + +NOTE – Alternative values for RESERVED\_B may be specified in the future as an indication of a codestream that is not compatible with prior decoder versions. + +### 8.3.4 HARD\_TILING\_FLAG + +HARD\_TILING\_FLAG is a 1-bit syntax element. If HARD\_TILING\_FLAG is equal to TRUE, overlap filtering is not performed across tile boundaries (hard tiles). Otherwise (HARD\_TILING\_FLAG is equal to FALSE), overlap filtering is performed across tile boundaries (soft tiles). + +### 8.3.5 RESERVED\_C + +RESERVED\_C is a 3-bit syntax element that shall be equal to 1 in all codestreams conforming to this version of this Specification. All other values are reserved. Decoders conforming to this version of this Specification shall ignore the value of RESERVED\_C. + +NOTE – The purpose of the specification for decoders to ignore the value of RESERVED\_C is to enable the future definition of a backward-compatible usage of different values of this syntax element. + +### 8.3.6 TILING\_FLAG + +TILING\_FLAG is a 1-bit syntax element. If TILING\_FLAG is equal to TRUE, both the syntax elements NUM\_VER\_TILES\_MINUS1 and NUM\_HOR\_TILES\_MINUS1 are present in the codestream. Otherwise, these syntax elements are not present, and the number of tiles is equal to 1. + +### 8.3.7 FREQUENCY\_MODE\_CODESTREAM\_FLAG + +FREQUENCY\_MODE\_CODESTREAM\_FLAG is a 1-bit syntax element. + +If FREQUENCY\_MODE\_CODESTREAM\_FLAG is equal to FALSE, the codestream is laid out in the spatial mode. If FREQUENCY\_MODE\_CODESTREAM\_FLAG is equal to TRUE, the codestream is laid out in the frequency mode. + +### 8.3.8 SPATIAL\_XFRM\_SUBORDINATE + +SPATIAL\_XFRM\_SUBORDINATE is a 3-bit syntax element that, in the absence of any overriding indication as determined by the application or by a file format usage context, indicates a preferred spatial transformation that should be applied to the decoded image, as specified in Table 21 as follows. + +- The "RCW" table column, when equal to 1, indicates a 90° clockwise rotation request of the output image. +- The "FlipH" table column, when equal to 1, indicates a horizontal flip request of the output image. +- The "FlipV" table column, when equal to 1, indicates a vertical flip request of the output image. +- The "Example" table column visually illustrates the application of the requested transformation to an image of the character "P". +- The "Fill" table column indicates the location of the [0][0] image sample coordinate position after application of the requested transformation, as follows: + - "TL" indicates that row 0 represents the top edge of the image and column 0 represents the left edge of the image. + - "BL" indicates that row 0 represents the bottom edge of the image and column 0 represents the left edge of the image. + - "TR" indicates that row 0 represents the top edge of the image and column 0 represents the right edge of the image. + - "BR" indicates that row 0 represents the bottom edge of the image and column 0 represents the right edge of the image. + - "RT" indicates that row 0 represents the right edge of the image and column 0 represents the top edge of the image. + - "RB" indicates that row 0 represents the right edge of the image and column 0 represents the bottom edge of the image. + +- "LT" indicates that row 0 represents the left edge of the image and the column 0 represents the top edge of the image. +- "LB" indicates that row 0 represents the left edge of the image and column 0 represents the bottom edge of the image. + +NOTE – The TIFF Revision 6.0 specification includes an "Orientation" tag with a similar purpose. The TIFF Orientation tag values that correspond to the SPATIAL\_XFRM\_SUBORDINATE values 0, 1, 2, 3, 4, 5, 6, and 7 are 1, 4, 2, 3, 6, 7, 5, and 8, respectively. + +**Table 21 – Interpretation of SPATIAL\_XFRM\_SUBORDINATE** + +| SPATIAL_XFRM_SUBORDINATE | RCW | FlipH | FlipV | Example | Fill | +|--------------------------|-----|-------|-------|----------------------------------------------------------------------------------------------------------------------------------------------------------------|------| +| 0 | 0 | 0 | 0 |

Image: Example image for SPATIAL_XFRM_SUBORDINATE 0: A 2x2 grid of 'P' characters, top-left to bottom-right.

| TL | +| 1 | 0 | 0 | 1 |

Image: Example image for SPATIAL_XFRM_SUBORDINATE 1: A 2x2 grid of 'P' characters, top-right to bottom-left.

| BL | +| 2 | 0 | 1 | 0 |

Image: Example image for SPATIAL_XFRM_SUBORDINATE 2: A 2x2 grid of 'P' characters, top-left to bottom-right, mirrored horizontally.

| TR | +| 3 | 0 | 1 | 1 |

Image: Example image for SPATIAL_XFRM_SUBORDINATE 3: A 2x2 grid of 'P' characters, top-right to bottom-left, mirrored horizontally.

| BR | +| 4 | 1 | 0 | 0 |

Image: Example image for SPATIAL_XFRM_SUBORDINATE 4: A 2x2 grid of 'P' characters, top-left to bottom-right, mirrored vertically.

| RT | +| 5 | 1 | 0 | 1 |

Image: Example image for SPATIAL_XFRM_SUBORDINATE 5: A 2x2 grid of 'P' characters, top-right to bottom-left, mirrored vertically.

| RB | +| 6 | 1 | 1 | 0 |

Image: Example image for SPATIAL_XFRM_SUBORDINATE 6: A 2x2 grid of 'P' characters, top-left to bottom-right, mirrored both horizontally and vertically.

| LT | +| 7 | 1 | 1 | 1 |

Image: Example image for SPATIAL_XFRM_SUBORDINATE 7: A 2x2 grid of 'P' characters, top-right to bottom-left, mirrored both horizontally and vertically.

| LB | + +### 8.3.9 INDEX\_TABLE\_PRESENT\_FLAG + +INDEX\_TABLE\_PRESENT\_FLAG is a 1-bit syntax element that specifies whether the index table is present in the codestream. If FREQUENCY\_MODE\_CODESTREAM\_FLAG is equal to TRUE or NUM\_VER\_TILES\_MINUS1 is greater than 0 or NUM\_HOR\_TILES\_MINUS1 is greater than 0, it is a requirement of codestream conformance that INDEX\_TABLE\_PRESENT\_FLAG shall be equal to TRUE. If INDEX\_TABLE\_PRESENT\_FLAG is equal to TRUE, the index table is present in the codestream. Otherwise, the index table is not present in the codestream. See 8.5. + +### 8.3.10 OVERLAP\_MODE + +OVERLAP\_MODE is a 2-bit syntax element that specifies the overlap processing mode. + +When OVERLAP\_MODE is equal to 0, no overlap filtering is performed. Otherwise, if OVERLAP\_MODE is equal to 1, only the second level overlap filtering is performed. Otherwise, if OVERLAP\_MODE is equal to 2, both first level and second level overlap filtering are performed. The value 3 is reserved. + +NOTE – The trade-offs between complexity and compression efficiency related to the different overlap modes are discussed in D.4. + +### 8.3.11 SHORT\_HEADER\_FLAG + +SHORT\_HEADER\_FLAG is a 1-bit syntax element that specifies the number of bits required to represent the syntax elements for the width and the height of the image and the tiles. If SHORT\_HEADER\_FLAG is equal to TRUE, WIDTH\_MINUS1 and HEIGHT\_MINUS1 are 16-bit syntax elements, and TILE\_WIDTH\_IN\_MB[n], when present, and TILE\_HEIGHT\_IN\_MB[n], when present, are 8-bit syntax elements. Otherwise, WIDTH\_MINUS1 and HEIGHT\_MINUS1 are 32-bit syntax elements, and TILE\_WIDTH\_IN\_MB[n], when present, and TILE\_HEIGHT\_IN\_MB[n], when present, are 16-bit syntax elements. + +### 8.3.12 LONG\_WORD\_FLAG + +LONG\_WORD\_FLAG is a 1-bit syntax element that specifies the range of values of variables associated with the decoding process (clause 9). The constraints imposed by LONG\_WORD\_FLAG equal to FALSE have the following scope: + +- All values of the global array variable MbDCLP[ ][ ][ ] +- All values of the global array variable MBBuffer[ ][ ][ ] +- All values of the global array variable PredDCLP[ ][ ][ ] +- Values of global array variable ImagePlane[ ][ ][ ] in the sample reconstruction process specified in 9.9. + +NOTE 1 – Values of the global array variable ImagePlane[ ][ ][ ] in the output formatting process specified in 9.10 are not included in the scope of the constraints imposed by LONG\_WORD\_FLAG equal to FALSE. + +- All values of local variables used in the sample reconstruction process specified in clause 9.9 except the index variables used to address the elements of arrays. + +NOTE 2 – Local variables used in the output formatting process specified in 9.10 are not included in the scope of the constraints imposed by LONG\_WORD\_FLAG equal to FALSE. + +The variables associated with the decoding process specified in clause 9 shall be constrained as follows: + +- If LONG\_WORD\_FLAG is equal to TRUE, it is a requirement for codestream conformance to this Specification that the range of values of all variables associated with the decoding process (clause 9) shall not exceed the signed 32-bit range from $-2^{31}$ range to $2^{31}-1$ , inclusive, although the range of values of these variables may exceed the signed 16-bit range from $-2^{15}$ range to $2^{15}-1$ , inclusive. Thus, all variables of the decoding process can be stored by decoders as 32 bit two's complement integers while producing output conforming to this Specification (regardless of the value of LONG\_WORD\_FLAG). +- Otherwise (LONG\_WORD\_FLAG is equal to FALSE), it is a requirement for codestream conformance to this Specification that the range of values of the specific affected variables listed above shall not exceed the signed 16-bit range from $-2^{15}$ range to $2^{15}-1$ , inclusive, and that the range of values of all intermediate expressions and other variables associated with the decoding process for the codestream shall not exceed the signed 32-bit range from $-2^{31}$ range to $2^{31}-1$ , inclusive. In this case, it is sufficient for decoders to store the affected variables of the decoding process as 16 bit two's complement integers in order to produce output images conforming to this Specification. + +NOTE 3 – Decoder implementations need not use two's complement arithmetic using fixed-word-length storage and processing. However, if such a representation is used, 32-bit variable storage and 32-bit arithmetic processing elements are sufficient to decode an image, regardless of the value of LONG\_WORD\_FLAG. The LONG\_WORD\_FLAG element can be used by the decoder to optimize its resource usage for the sample reconstruction process. + +### 8.3.13 WINDOWING\_FLAG + +WINDOWING\_FLAG is a 1-bit syntax element that specifies whether syntax elements specifying windowing dimensions (TOP\_MARGIN, LEFT\_MARGIN, BOTTOM\_MARGIN, and RIGHT\_MARGIN as specified in 8.3.27 to 8.3.30) are present in the codestream. If WINDOWING\_FLAG is equal to TRUE, these syntax elements are present in the codestream. If WINDOWING\_FLAG is equal to FALSE, these syntax elements are not present in the codestream. + +### 8.3.14 TRIM\_FLEXBITS\_FLAG + +TRIM\_FLEXBITS\_FLAG is a 1-bit syntax element that specifies whether TRIM\_FLEXBITS syntax element is present in the TILE\_SPATIAL() syntax structure and TILE\_FLEXBITS() syntax structure. If TRIM\_FLEXBITS\_FLAG is equal to TRUE, TRIM\_FLEXBITS is present. Otherwise, TRIM\_FLEXBITS is not present. + +### 8.3.15 RESERVED\_D + +RESERVED\_D is a 1-bit syntax element. The value of RESERVED\_D shall be equal to 0. Other values are reserved. Decoders shall ignore the value of this syntax element. + +NOTE – The purpose of the specification for decoders to ignore the value of RESERVED\_D is to enable the future definition of a backward-compatible usage of different values of this syntax element. + +### 8.3.16 RED\_BLUE\_NOT\_SWAPPED\_FLAG + +RED\_BLUE\_NOT\_SWAPPED\_FLAG is a 1-bit syntax element. Its interpretation is specified as follows. + +- If OUTPUT\_CLR\_FMT is equal to RGB and OUTPUT\_BITDEPTH is equal to BD5, BD565 or BD10, the value of RED\_BLUE\_NOT\_SWAPPED\_FLAG affects the operation of the output formatting process. +- Otherwise, the value of RED\_BLUE\_NOT\_SWAPPED\_FLAG shall be equal to 0 in all codestreams conforming to this version of this Specification. The value 1 is reserved. Decoders conforming to this version of this Specification shall ignore the value of RED\_BLUE\_NOT\_SWAPPED\_FLAG in this case. + +NOTE – The specification of semantics for RED\_BLUE\_NOT\_SWAPPED\_FLAG was not included in the original edition of this Specification. The specification of RED\_BLUE\_NOT\_SWAPPED\_FLAG was added later to address a problem with respect to the observed behaviour of existing implementations. In principle, when OUTPUT\_CLR\_FMT is equal to RGB and OUTPUT\_BITDEPTH is equal to BD5, BD565, or BD10, the value 1 for RED\_BLUE\_NOT\_SWAPPED\_FLAG should ordinarily provide better compression capability than the value 0. However, early product implementations of this Specification have operated in a manner corresponding to the value 0. + +### 8.3.17 PREMULIPLIED\_ALPHA\_FLAG + +PREMULIPLIED\_ALPHA\_FLAG is a 1-bit syntax element that can be used, when an alpha image plane is present, to indicate that the coded image channels other than the alpha channel are considered to be in pre-multiplied form in relation to the alpha channel. + +NOTE 1 – The designation of an alpha channel as pre-multiplied indicates that the decoded sample values do not require multiplication by the alpha channel values when performing compositing (as any such necessary multiplication process was performed as a pre-processing step prior to encoding). + +When `PREMULTIPLIED_ALPHA_FLAG` is equal to `TRUE` in the `IMAGE_HEADER()` of the coded image that contains the alpha image plane, the channels other than the alpha channel are indicated to be in pre-multiplied form in relation to the alpha channel. + +When no alpha image plane is present, `PREMULTIPLIED_ALPHA_FLAG` shall be equal to `FALSE`, and decoders shall ignore the value of this syntax element. + +When an alpha image plane is present as a separate alpha image plane, `PREMULTIPLIED_ALPHA_FLAG` shall be equal to `FALSE` in the `IMAGE_HEADER()` of the coded image that does not contain the alpha image plane, and decoders shall ignore the value of this syntax element in the `IMAGE_HEADER()` of the coded image that does not contain the alpha image plane. + +When an alpha image plane is present and `PREMULTIPLIED_ALPHA_FLAG` is equal to `FALSE` in the `IMAGE_HEADER()` of the coded image that contains the alpha image plane, other indicators provided by other means not specified in the main body of this Specification should be used to determine whether the channels other than the alpha channel (when present) are considered to be in pre-multiplied form in relation to the alpha channel. When an alpha image plane is present and `PREMULTIPLIED_ALPHA_FLAG` is equal to `FALSE` in the `IMAGE_HEADER()` of the coded image that contains the alpha image plane and such other indicators are not available, it is suggested that the default interpretation should be that the channels other than the alpha channel are considered not to be in pre-multiplied form in relation to the alpha channel. + +NOTE 2 – The specification of semantics for `PREMULTIPLIED_ALPHA_FLAG` was not included in the original edition of this Specification. The specification of `PREMULTIPLIED_ALPHA_FLAG` was added later to correct for the ambiguity of interpretation resulting from absence of such an indicator (when no indication is provided by other means outside the coded image syntax). In the original edition of this Specification, the bit corresponding to `PREMULTIPLIED_ALPHA_FLAG` was required to be equal to 0 and decoders were required to ignore the value of this bit. + +NOTE 3 – When the file format specified in Annex A is used, the `PIXEL_FORMAT` value indicates whether the channels other than the alpha channel (when present) are considered to be in pre-multiplied form in relation to the alpha channel, and the value of `PREMULTIPLIED_ALPHA_FLAG` is required to be consistent with the `PIXEL_FORMAT` value. When the codestream is conveyed by some means other than the file format specified in Annex A, some indicator may be available to indicate whether the channels other than the alpha channel (when present) are considered to be in pre-multiplied form in relation to the alpha channel, and the value of `PREMULTIPLIED_ALPHA_FLAG` should be set to be consistent with any such indicator. + +### 8.3.18 ALPHA\_IMAGE\_PLANE\_FLAG + +`ALPHA_IMAGE_PLANE_FLAG` is a 1-bit syntax element that specifies whether an alpha image plane is present in the codestream. If `ALPHA_IMAGE_PLANE_FLAG` is equal to `TRUE`, an alpha image plane is present. If `ALPHA_IMAGE_PLANE_FLAG` is equal to `FALSE`, no alpha image plane is present in the codestream. + +NOTE – If `ALPHA_IMAGE_PLANE_FLAG` is equal to `FALSE`, an alpha image plane can be carried as a separate image within a system or file. + +### 8.3.19 OUTPUT\_CLR\_FMT + +`OUTPUT_CLR_FMT` is a 4-bit syntax element that specifies the colour format of the output image as specified in Table 22. + +**Table 22 – OUTPUT\_CLR\_FMT** + +| OUTPUT_CLR_FMT | Mnemonic | +|-----------------------|-----------------| +| 0 | YONLY | +| 1 | YUV420 | +| 2 | YUV422 | +| 3 | YUV444 | +| 4 | CMYK | +| 5 | CMYKDIRECT | +| 6 | NCOMPONENT | +| 7 | RGB | +| 8 | RGBE | +| 9-15 | RESERVED | + +If `IsCurrPlaneAlphaFlag` is equal to `TRUE`, the value of `OUTPUT_CLR_FMT` shall be equal to 0. + +For the cases where OUTPUT\_CLR\_FMT is equal to YUV420, YUV422 or YUV444, there are three output colour components: the component corresponding to index 0 is the Y component, while the U and V correspond to colour components 1 and 2, respectively. For CMYK and CMYKDIRECT, components 0, 1, 2, and 3 correspond to the C, M, Y, and K components, respectively. For RGB, components 0, 1 and 2 correspond to R, G, and B, respectively and for RGBE, components 0, 1, 2, and 3 correspond to the R, G, B, and E components, respectively. + +### 8.3.20 OUTPUT\_BITDEPTH + +OUTPUT\_BITDEPTH is a 4-bit syntax element that specifies the bit depth and corresponding representation of the output image, as specified in Table 23. BD1WHITE1, BD1BLACK1, BD8, BD16, BD5 and BD10 are unsigned integer formats, corresponding to 1, 1, 8, 16, 5 and 10 bits per component, respectively, having a representation specified in 9.10.8. In BD1WHITE1, a value of 0 indicates the minimum level or black for the specific channel and the value 1 indicates the maximum value for that channel. In BD1BLACK1, a value of 1 indicates the minimum level or black for the specific channel and the value 0 indicates the maximum value for that channel. BD16S and BD32S are signed (two's complement) integer formats corresponding to 16 and 32 bits per component, respectively. BD16F is 16-bit Half float (1-bit sign, 5-bit exponent and 10-bit mantissa where the MSB is the sign bit) having a representation as specified in 9.10.7.3. BD32F is 32-bit float (1-bit sign, 8-bit exponent, and 23-bit mantissa where the MSB is the sign bit) having a representation as specified in 9.10.7.3. BD565 corresponds to unsigned integer formats where the R, G and B components have 5, 6 and 5 bits, respectively, having a representation as specified in 9.10.8. + +The values of OUTPUT\_BITDEPTH and OUTPUT\_CLR\_FMT shall be constrained as specified in 9.10. + +NOTE – See 9.10.7 for more details on the representation of these formats. + +**Table 23 – OUTPUT\_BITDEPTH** + +| OUTPUT_BITDEPTH | Mnemonic | +|-----------------|-----------| +| 0 | BD1WHITE1 | +| 1 | BD8 | +| 2 | BD16 | +| 3 | BD16S | +| 4 | BD16F | +| 5 | RESERVED | +| 6 | BD32S | +| 7 | BD32F | +| 8 | BD5 | +| 9 | BD10 | +| 10 | BD565 | +| 11-14 | RESERVED | +| 15 | BD1BLACK1 | + +### 8.3.21 WIDTH\_MINUS1 + +WIDTH\_MINUS1 plus 1 is the output image width. If SHORT\_HEADER\_FLAG is equal to TRUE, WIDTH\_MINUS1 is a 16-bit syntax element. Otherwise, WIDTH\_MINUS1 is a 32-bit syntax element. When OUTPUT\_CLR\_FMT is equal to YUV420 or YUV422, it is a requirement of codestream conformance to this Specification that the value of WIDTH\_MINUS1 + 1 shall be an integer multiple of 2. + +It is a requirement of codestream conformance to this Specification that the value of WIDTH\_MINUS1 + 1 + LEFT\_MARGIN + RIGHT\_MARGIN shall be an integer multiple of 16. When INTERNAL\_CLR\_FMT is equal to YUV420 or YUV422 and OVERLAP\_MODE is equal to 2, it is a requirement of codestream conformance to this Specification that the value of WIDTH\_MINUS1 + 1 + LEFT\_MARGIN + RIGHT\_MARGIN shall be greater than or equal to 32. + +NOTE – Images with INTERNAL\_CLR\_FMT equal to YUV420 or YUV422 and OVERLAP\_MODE equal to 2 must have a width of at least 2 macroblocks due to the adjacent coefficient residual process described in 9.9.3.1. + +### 8.3.22 HEIGHT\_MINUS1 + +HEIGHT\_MINUS1 plus 1 is the output image height. If SHORT\_HEADER\_FLAG is equal to TRUE, HEIGHT\_MINUS1 is a 16-bit syntax element. Otherwise, HEIGHT\_MINUS1 is a 32-bit syntax element. When OUTPUT\_CLR\_FMT is equal to YUV420, it is a requirement of codestream conformance to this Specification that the value of HEIGHT\_MINUS1 + 1 shall be an integer multiple of 2. + +It is a requirement of codestream conformance to this Specification that the value of HEIGHT\_MINUS1 + 1 + TOP\_MARGIN + BOTTOM\_MARGIN shall be an integer multiple of 16. + +### 8.3.23 NUM\_VER\_TILES\_MINUS1 + +NUM\_VER\_TILES\_MINUS1 is a 12-bit syntax element that is present when TILING\_FLAG is equal to TRUE, and specifies the number of tiles in a row minus 1. When NUM\_VER\_TILES\_MINUS1 is not present, its value shall be inferred to be equal to 0. + +NOTE – "Vertical" indicates that the partitioning of the image corresponding to these tiles runs in the vertical direction. + +### 8.3.24 NUM\_HOR\_TILES\_MINUS1 + +NUM\_HOR\_TILES\_MINUS1 is a 12-bit syntax element that is present when TILING\_FLAG is equal to TRUE, and specifies the number of tiles in a column minus 1. When NUM\_HOR\_TILES\_MINUS1 is not present, its value shall be inferred to be equal to 0. + +NOTE – "Horizontal" indicates that the partitioning of the image corresponding to these tiles runs in the horizontal direction. + +### 8.3.25 TILE\_WIDTH\_IN\_MB[n] + +TILE\_WIDTH\_IN\_MB[n] is a syntax element that specifies the width (in macroblock units) of the n-th tile column, where the 0-th tile column is the leftmost tile column in the image, and subsequent tile columns are numbered consecutively, left to right. If SHORT\_HEADER\_FLAG is equal to TRUE, TILE\_WIDTH\_IN\_MB[n] is an 8-bit syntax element. Otherwise, it is a 16-bit syntax element. + +The width of the rightmost tile in macroblock units is derived by subtracting the cumulative width of the previous tiles from the width of the coded area in macroblock units ExtendedWidth[0] divided by 16. + +The position of the left boundary of the tile, LeftMBIndexOfTile[ ], is calculated by calling DetermineLeftBoundaryofTile( ) in the pseudocode in Table 24. + +**Table 24 – Pseudocode to determine the position of the left boundaries of the tiles** + +| DetermineLeftBoundaryofTile( ) { | Reference | +|---------------------------------------------------------------------|-----------| +| LeftMBIndexOfTile[0] = 0 | | +| for (n = 0; n < NUM_VER_TILES_MINUS1; n++) | | +| LeftMBIndexOfTile[n+1] = LeftMBIndexOfTile[n] + TILE_WIDTH_IN_MB[n] | | +| LeftMBIndexOfTile[NUM_VER_TILES_MINUS1 + 1] = MBWidth | | +| } | | + +When INTERNAL\_CLR\_FMT is equal to YUV420 or YUV422, OVERLAP\_MODE is equal to 2, and HARD\_TILING\_FLAG is equal to TRUE, TILE\_WIDTH\_IN\_MB[n] shall be greater than or equal to 2 for all tiles. + +When INTERNAL\_CLR\_FMT is equal to YUV420 or YUV422, OVERLAP\_MODE is equal to 2, and HARD\_TILING\_FLAG is equal to TRUE, MBWidth – LeftMBIndexOfTile[NUM\_VER\_TILES\_MINUS1] shall be greater than or equal to 2. + +### 8.3.26 TILE\_HEIGHT\_IN\_MB[n] + +TILE\_HEIGHT\_IN\_MB[n] is a syntax element that specifies the height (in macroblock units) of the n-th tile row, where the 0-th tile row is the top tile row in the image, and subsequent tile rows are numbered consecutively, top to bottom. If SHORT\_HEADER\_FLAG is equal to TRUE, TILE\_HEIGHT\_IN\_MB[n] is an 8-bit syntax element. Otherwise, it is a 16-bit syntax element. + +The height of the bottom tile in macroblock units is derived by subtracting the transmitted heights (plus 1) from the height of the coded area in macroblock units ExtendedHeight[0] divided by 16. + +The position of the top boundary of the tile, TopMBIndexOfTile[ ], is calculated by calling DetermineTopBoundaryofTile( ) as specified in the pseudocode in Table 25. + +**Table 25 – Pseudocode to determine the position of the top boundaries of the tiles** + +| DetermineTopBoundaryofTile( ) { | Reference | +|--------------------------------------------------------------------|-----------| +| TopMBIndexOfTile[0] = 0 | | +| for (n = 0; n < NUM_HOR_TILES_MINUS1; n++) | | +| TopMBIndexOfTile[n+1] = TopMBIndexOfTile[n] + TILE_HEIGHT_IN_MB[n] | | +| TopMBIndexOfTile[NUM_HOR_TILES_MINUS1 + 1] = MBHeight | | +| } | | + +The number of macroblocks in a tile, NumMBInTile[ ], is calculated by calling DetermineNumMBInTile( ) as specified in the pseudocode in Table 26. + +**Table 26 – Pseudocode to determine the number of macroblocks in each tile** + +| DetermineNumMBInTile() { | Reference | +|----------------------------------------------------------------|-----------| +| n = 0 | | +| for (i = 0; i < NUM_HOR_TILES_MINUS1 + 1; i++) | | +| for (j = 0; j < NUM_VER_TILES_MINUS1 + 1; j++) { | | +| NumMBInTile[n] =
TILE_HEIGHT_IN_MB[i] * TILE_WIDTH_IN_MB[j] | | +| n++ | | +| } | | +| } | | + +### 8.3.27 TOP\_MARGIN + +TOP\_MARGIN is a 6-bit syntax element that is present when WINDOWING\_FLAG is equal to TRUE, and specifies the vertical offset of the top boundary of the output image relative to the top edge of the extended image. When TOP\_MARGIN is not present, its value shall be inferred to be equal to 0. When OUTPUT\_CLR\_FMT is equal to YUV420, it is a requirement of codestream conformance to this Specification that the value of TOP\_MARGIN shall be an integer multiple of 2. + +### 8.3.28 LEFT\_MARGIN + +LEFT\_MARGIN is a 6-bit syntax element that is present when WINDOWING\_FLAG is equal to TRUE, and specifies the horizontal offset of the left boundary of the output image relative to the left edge of the extended image. When LEFT\_MARGIN is not present, its value shall be inferred to be equal to 0. When OUTPUT\_CLR\_FMT is equal to YUV420 or YUV422, it is a requirement of codestream conformance to this Specification that the value of LEFT\_MARGIN shall be an integer multiple of 2. + +### 8.3.29 BOTTOM\_MARGIN + +BOTTOM\_MARGIN is a 6-bit syntax element that is present when WINDOWING\_FLAG is equal to TRUE, and specifies the vertical offset of the bottom of the output image relative to the bottom edge of the extended image. When BOTTOM\_MARGIN is not present, its value shall be inferred as follows: + +- If HEIGHT\_MINUS1 + 1 is an integer multiple of 16, BOTTOM\_MARGIN shall be inferred to be equal to 0. +- Otherwise, BOTTOM\_MARGIN shall be inferred to be equal to $16 - ((\text{HEIGHT\_MINUS1} + 1) \% 16)$ . + +When OUTPUT\_CLR\_FMT is equal to YUV420, it is a requirement of codestream conformance to this Specification that the value of BOTTOM\_MARGIN shall be an integer multiple of 2. + +### 8.3.30 RIGHT\_MARGIN + +RIGHT\_MARGIN is a 6-bit syntax element that is present when WINDOWING\_FLAG is equal to TRUE, and specifies the horizontal offset of the right boundary of the output image relative to the right edge of the extended image. When RIGHT\_MARGIN is not present, its value shall be inferred as follows: + +- If WIDTH\_MINUS1 + 1 is an integer multiple of 16, RIGHT\_MARGIN shall be inferred to be equal to 0. +- Otherwise, RIGHT\_MARGIN shall be inferred to be equal to $16 - ((\text{WIDTH\_MINUS1} + 1) \% 16)$ . + +When OUTPUT\_CLR\_FMT is equal to YUV420 or YUV422, it is a requirement of codestream conformance to this Specification that the value of RIGHT\_MARGIN shall be an integer multiple of 2. + +## 8.4 IMAGE\_PLANE\_HEADER() + +### 8.4.1 Syntax structure + +The IMAGE\_PLANE\_HEADER( ) syntax structure is specified in Table 27. + +**Table 27 – IMAGE\_PLANE\_HEADER() syntax structure** + +| IMAGE_PLANE_HEADER() { | Descriptor | Reference | +|--------------------------------------------------------------------------------------------------|-------------------|------------------| +| INTERNAL_CLR_FMT | u(3) | 8.4.2 | +| SCALED_FLAG | u(1) | 8.4.3 | +| BANDS_PRESENT | u(4) | 8.4.4 | +| if (INTERNAL_CLR_FMT == YUV444 INTERNAL_CLR_FMT == YUV420
INTERNAL_CLR_FMT == YUV422) { | | | +| if (INTERNAL_CLR_FMT == YUV420 INTERNAL_CLR_FMT == YUV422) { | | | +| RESERVED_E_BIT | u(1) | 8.4.5 | +| CHROMA_CENTERING_X | u(3) | 8.4.6 | +| } else /* INTERNAL_CLR_FMT == YUV444 */ | | | +| RESERVED_F | u(4) | 8.4.7 | +| if (INTERNAL_CLR_FMT == YUV420) { | | | +| RESERVED_G_BIT | u(1) | 8.4.8 | +| CHROMA_CENTERING_Y | u(3) | 8.4.9 | +| } else | | | +| RESERVED_H | u(4) | 8.4.10 | +| } else if (INTERNAL_CLR_FMT == NCOMPONENT) { | | | +| NUM_COMPONENTS_MINUS1 | u(4) | 8.4.11 | +| if (NUM_COMPONENTS_MINUS1 == 0xF) | | | +| NUM_COMPONENTS_EXTENDED_MINUS16 | u(12) | 8.4.12 | +| else | | | +| RESERVED_H | u(4) | 8.4.10 | +| } | | | +| if (OUTPUT_BITDEPTH == BD16 OUTPUT_BITDEPTH == BD16S
OUTPUT_BITDEPTH == BD32S) | | | +| SHIFT_BITS | u(8) | 8.4.13 | +| if (OUTPUT_BITDEPTH == BD32F) { | | | +| LEN_MANTISSA | u(8) | 8.4.14 | +| EXP_BIAS | i(8) | 8.4.15 | +| } | | | +| DC_IMAGE_PLANE_UNIFORM_FLAG | u(1) | 8.4.16 | +| if (DC_IMAGE_PLANE_UNIFORM_FLAG) | | | +| DC_QP() | | 8.4.22 | +| if (BANDS_PRESENT != DONLY) { | | | +| RESERVED_I_BIT | u(1) | 8.4.17 | +| LP_IMAGE_PLANE_UNIFORM_FLAG | u(1) | 8.4.18 | +| if (LP_IMAGE_PLANE_UNIFORM_FLAG) { | | | +| NumLPQPs = 1 | | | +| LP_QP() | | 8.4.23 | +| } | | | +| if (BANDS_PRESENT != NOHIGHPASS) { | | | +| RESERVED_J_BIT | u(1) | 8.4.19 | +| HP_IMAGE_PLANE_UNIFORM_FLAG | u(1) | 8.4.20 | +| if (HP_IMAGE_PLANE_UNIFORM_FLAG) { | | | +| NumHPQPs = 1 | | | +| HP_QP() | | 8.4.24 | +| } | | | +| } | | | +| } | | | +| while (!IS_BYTE_ALIGNED()) | | | +| BYTE_ALIGNMENT_BIT | u(1) | 8.4.21 | +| } | | | + +## 8.4.2 INTERNAL\_CLR\_FMT + +INTERNAL\_CLR\_FMT is a 3-bit syntax element that specifies the internal colour format of the coded image as specified in Table 28. For OUTPUT\_BITDEPTH of BD16F and BD32F and OUTPUT\_CLR\_FMT of RGBE, only YUV444 shall be used. The values of INTERNAL\_CLR\_FMT and OUTPUT\_CLR\_FMT shall be constrained as specified in 9.10. + +**Table 28 – INTERNAL\_CLR\_FMT** + +| INTERNAL_CLR_FMT | Mnemonic | +|------------------|------------| +| 0 | YONLY | +| 1 | YUV420 | +| 2 | YUV422 | +| 3 | YUV444 | +| 4 | YUVK | +| 5 | RESERVED | +| 6 | NCOMPONENT | +| 7 | RESERVED | + +When IsCurrPlaneAlphaFlag is equal to TRUE, the value of INTERNAL\_CLR\_FMT shall be equal to 0. + +For the cases where INTERNAL\_CLR\_FMT is equal to YUV420, YUV422 or YUV444, there are three internal colour components: the component corresponding to index 0 is the Y component, and the U and V correspond to colour components 1 and 2, respectively. For YUVK, components 0, 1, 2, and 3 correspond to the Y, U, V, and K components, respectively. + +### 8.4.3 SCALED\_FLAG + +SCALED\_FLAG is a 1-bit syntax element that specifies whether scaling is performed in the output formatting stage. If SCALED\_FLAG is equal to FALSE, scaling is not performed. If SCALED\_FLAG is equal to TRUE, scaling is performed as specified in 9.10.6. + +### 8.4.4 BANDS\_PRESENT + +BANDS\_PRESENT is a 4-bit syntax element that indicates whether the various frequency bands are present in the codestream, as specified in Table 29. + +**Table 29 – BANDS\_PRESENT** + +| BANDS_PRESENT | Mnemonic | Interpretation | +|---------------|------------|---------------------------------| +| 0 | ALL | All sub-bands are present | +| 1 | NOFLEXBITS | Flexbits is not present | +| 2 | NOHIGHPASS | Flexbits and HP are not present | +| 3 | DONLY | Only DC is present | +| 4-15 | RESERVED | | + +The number of bands present in the codestream, NumBands, is specified by calling DetermineNumBands( ), which is specified by the pseudocode in Table 30. When IsCurrPlaneAlphaFlag is equal to TRUE, it is a requirement of codestream conformance to this Specification that the value of NumBands shall be less than or equal to the value of NumBandsOfPrimary. + +**Table 30 – Pseudocode to determine the number of bands present in the codestream, NumBands** + +| DetermineNumBands() { | Reference | +|---------------------------------------|-----------| +| if (BANDS_PRESENT == ALL) | | +| NumBands = 4 | | +| else if (BANDS_PRESENT == NOFLEXBITS) | | +| NumBands = 3 | | +| else if (BANDS_PRESENT == NOHIGHPASS) | | +| NumBands = 2 | | +| else /* (BANDS_PRESENT == DONLY) */ | | +| NumBands = 1 | | +| if (IsCurrPlaneAlphaFlag == FALSE) | | +| NumBandsOfPrimary = NumBands | | +| } | | + +#### 8.4.5 RESERVED\_E\_BIT + +RESERVED\_E\_BIT is a 1-bit syntax element and is present when INTERNAL\_CLR\_FMT is equal to YUV422 or INTERNAL\_CLR\_FMT is equal to YUV420. + +When RESERVED\_E\_BIT is present, its value shall be equal to 0. The value 1 for RESERVED\_E\_BIT is reserved. + +The value of RESERVED\_E\_BIT shall be ignored by decoders. + +NOTE – The purpose of the specification for decoders to ignore the value of RESERVED\_E\_BIT is to enable the future definition of a backward-compatible usage of different values of this syntax element. + +#### 8.4.6 CHROMA\_CENTERING\_X + +CHROMA\_CENTERING\_X is a 3-bit syntax element. It is present when INTERNAL\_CLR\_FMT is equal to YUV422 or YUV420. When CHROMA\_CENTERING\_X is not present, its value should be inferred to be equal to 0. + +CHROMA\_CENTERING\_X indicates the positioning alignment of the chroma sampling grid with respect to the luma sampling grid. When present and in the range of 0 to 4, inclusive, CHROMA\_CENTERING\_X indicates that the left-most sample of each row of each chroma array of the image is considered to be horizontally positioned at the position CHROMA\_CENTERING\_X with respect to the left-most sample of each row of the luma array, in units of quarter luma sample positions. When present and equal to 7, CHROMA\_CENTERING\_X indicates that the positioning alignment is unknown or unspecified. + +For example, when CHROMA\_CENTERING\_X is equal to 0 and INTERNAL\_CLR\_FMT is equal to YUV422 or YUV420, each chroma sample is considered to be horizontally located at the same position as the left-most sample of a pair of luma samples. + +The value of CHROMA\_CENTERING\_X shall be equal to 0, 1, 2, 3, 4, or 7. The values 5 and 6 are reserved. Decoders conforming to this version of this Specification should treat the values 5 and 6 as equivalent to the value 7. + +NOTE – CHROMA\_CENTERING\_X is useful to aid in performing appropriate upsampling conversion from 4:2:0 or 4:2:2 to 4:4:4. However, the use of CHROMA\_CENTERING\_X is not required for decoder conformance to this Specification, as the manner of performing such an upsampling process is outside the scope of this Specification. + +#### 8.4.7 RESERVED\_F + +RESERVED\_F is a 4-bit syntax element that is present when INTERNAL\_CLR\_FMT is equal to YUV444. + +When RESERVED\_F is present, its value shall be equal to 0. Decoders shall ignore the value of this syntax element. + +NOTE – The specification for decoders to ignore the value of RESERVED\_F is to enable the future definition of a backward-compatible usage of different values of this syntax element. + +#### 8.4.8 RESERVED\_G\_BIT + +RESERVED\_G\_BIT is a 1-bit syntax element that is present when INTERNAL\_CLR\_FMT is equal to YUV420. + +When RESERVED\_G\_BIT is present, its value shall be equal to 0. The value 1 for RESERVED\_G\_BIT is reserved. + +Decoders shall ignore the value of RESERVED\_G\_BIT. + +NOTE – The specification for decoders to ignore the value of RESERVED\_G\_BIT is to enable the future definition of a backward-compatible usage of different values of this syntax element. + +#### 8.4.9 CHROMA\_CENTERING\_Y + +CHROMA\_CENTERING\_Y is a 3-bit syntax element. It is present when INTERNAL\_CLR\_FMT is equal to YUV420. When CHROMA\_CENTERING\_Y is not present, its value should be inferred to be equal to 0. + +CHROMA\_CENTERING\_Y indicates the positioning alignment of the chroma sampling grid with respect to the luma sampling grid. When present and in the range of 0 to 4, inclusive, CHROMA\_CENTERING\_Y indicates that the topmost sample of each column of each chroma array of the image is considered to be vertically positioned at the position CHROMA\_CENTERING\_Y with respect to the topmost sample of each column of the luma array, in units of quarter luma sample positions. When present and equal to 7, CHROMA\_CENTERING\_Y indicates that the positioning alignment is unknown or unspecified. + +For example, when CHROMA\_CENTERING\_Y is equal to 0 and INTERNAL\_CLR\_FMT is equal to YUV420, each chroma sample is considered to be vertically located at the same position as the upper sample of a pair of luma samples. + +The value of CHROMA\_CENTERING\_Y shall be equal to 0, 1, 2, 3, 4 or 7. The values 5 and 6 are reserved. Decoders conforming to this version of this Specification should treat the values 5 and 6 as equivalent to the value 7. + +NOTE – CHROMA\_CENTERING\_Y is useful to aid in performing appropriate upsampling conversion from 4:2:0 to 4:2:2 or 4:4:4. However, the use of CHROMA\_CENTERING\_Y is not required for decoder conformance to this Specification, as the manner of performing such an upsampling process is outside the scope of this Specification. + +#### 8.4.10 RESERVED\_H + +RESERVED\_H is a 4-bit syntax element that is present when INTERNAL\_CLR\_FMT is equal to one of YUV444, YUV422, or NCOMPONENT. + +When RESERVED\_H is present, its value shall be equal to 0. Decoders shall ignore the value of this syntax element. + +NOTE – The specification for decoders to ignore the value of RESERVED\_H is to enable the future definition of a backward-compatible usage of different values of this syntax element. + +#### 8.4.11 NUM\_COMPONENTS\_MINUS1 + +NUM\_COMPONENTS\_MINUS1 is a 4-bit syntax element that is present when INTERNAL\_CLR\_FMT is equal to NCOMPONENT. + +The number of components, NumComponents, is specified in pseudocode in Table 31. + +#### 8.4.12 NUM\_COMPONENTS\_EXTENDED\_MINUS16 + +NUM\_COMPONENTS\_EXTENDED\_MINUS16 is a 12-bit syntax element that is present when NUM\_COMPONENTS\_MINUS1 is equal to 0xF. + +The number of components, NumComponents, is specified in pseudocode in Table 31. + +**Table 31 – Pseudocode to determine the number of components present in the codestream** + +| DetermineNumComponents() { | Reference | +|--------------------------------------------------------------------------------------------------------|-----------| +| if (INTERNAL_CLR_FMT == NCOMPONENT) | | +| if (NUM_COMPONENTS_MINUS1 == 0xF) | | +| NumComponents =
NUM_COMPONENTS_EXTENDED_MINUS16 + 16 | | +| else | | +| NumComponents = NUM_COMPONENTS_MINUS1 + 1 | | +| else if (INTERNAL_CLR_FMT == YONLY) | | +| NumComponents = 1 | | +| else if (INTERNAL_CLR_FMT == YUV420
INTERNAL_CLR_FMT == YUV422
INTERNAL_CLR_FMT == YUV444) | | +| NumComponents = 3 | | +| else if (INTERNAL_CLR_FMT == YUVK) | | +| NumComponents = 4 | | +| } | | + +#### 8.4.13 SHIFT\_BITS + +SHIFT\_BITS is an 8-bit syntax element that is present when OUTPUT\_BITDEPTH is equal to BD16, BD16S or BD32S. SHIFT\_BITS is used to left-shift the sample values in the output formatting stage as specified in 9.10.7. + +#### 8.4.14 LEN\_MANTISSA + +LEN\_MANTISSA is an 8-bit syntax element that is present when OUTPUT\_BITDEPTH is equal to BD32F. It specifies the number of mantissa bits that are specified by the integer representation of floating point data as specified in 9.10.7 prior to output conversion processing. + +#### 8.4.15 EXP\_BIAS + +EXP\_BIAS is an 8-bit syntax element that is present when OUTPUT\_BITDEPTH is equal to BD32F. This element specifies the bias of the exponent in the representation of floating point data as specified in 9.10.7. + +#### 8.4.16 DC\_IMAGE\_PLANE\_UNIFORM\_FLAG + +DC\_IMAGE\_PLANE\_UNIFORM\_FLAG is a 1-bit syntax element that specifies whether a single QP set is used for the DC band for all the macroblocks in the corresponding image plane. If DC\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to TRUE, a single QP set is used for the DC band of all tiles in the image (and hence for all macroblocks of all tiles), and + +this QP set is present in the image plane header. In this case, the DC QP set used for all tiles shall be set equal to the value specified in the image plane header. If DC\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to FALSE, the DC band of each tile may use a different QP set, and these QP sets are specified in the tile headers. + +#### 8.4.17 RESERVED\_I\_BIT + +RESERVED\_I\_BIT is a 1-bit syntax element. It is a requirement of codestream conformance to this Specification that the value of RESERVED\_I\_BIT shall be equal to FALSE. Decoders shall ignore (remove from the codestream and discard) the value of RESERVED\_I\_BIT. + +NOTE – The purpose of the specification for decoders to ignore the value of RESERVED\_I\_BIT is to enable the future definition of a backward-compatible usage of different values of this syntax element. + +#### 8.4.18 LP\_IMAGE\_PLANE\_UNIFORM\_FLAG + +LP\_IMAGE\_PLANE\_UNIFORM\_FLAG is a 1-bit syntax element that specifies whether a single QP set is used for the LP band. If LP\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to TRUE, a single QP set is used for the LP band of all tiles in the image (and hence for all macroblocks of all tiles), and this QP set is specified in the image plane header. In this case, the LP QP set for all tiles shall be set equal to the corresponding values specified in the image plane header. If LP\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to FALSE, the LP band of each tile may use a different QP set, and these QP sets are specified in the tile header. + +#### 8.4.19 RESERVED\_J\_BIT + +RESERVED\_J\_BIT is a 1-bit syntax element. It is a requirement of codestream conformance to this Specification that the value of RESERVED\_J\_BIT shall be equal to FALSE. Decoders shall ignore (remove from the codestream and discard) the value of RESERVED\_J\_BIT. + +NOTE – The purpose of the specification for decoders to ignore the value of RESERVED\_J\_BIT is to enable the future definition of a backward-compatible usage of different values of this syntax element. + +#### 8.4.20 HP\_IMAGE\_PLANE\_UNIFORM\_FLAG + +HP\_IMAGE\_PLANE\_UNIFORM\_FLAG is a 1-bit syntax element that specifies whether a single QP set is used for the HP band. If HP\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to TRUE, a single QP set shall be used for the HP band of all tiles in the image (and hence for all macroblocks of all tiles), and this QP set is specified in the image plane header. In this case, the HP QP set for all tiles shall be set equal to the values specified in the image plane header. If HP\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to FALSE, multiple QP sets may be used for the HP bands of each colour component in each tile, and these QP sets are specified in the tile headers. + +#### 8.4.21 BYTE\_ALIGNMENT\_BIT + +BYTE\_ALIGNMENT\_BIT is a 1-bit syntax element. When it is present, its value shall be equal to 0. The value 1 is reserved. + +#### 8.4.22 DC\_QP() + +##### 8.4.22.1 Syntax structure + +The DC\_QP() syntax structure is specified in Table 32. + +Table 32 – DC\_QP() syntax structure + +| DC_QP() { | Descriptor | Reference | +|-------------------------------------------|------------|-----------| +| if (NumComponents != 1) | | | +| COMPONENT_MODE | u(2) | 8.4.22.2 | +| if (COMPONENT_MODE == UNIFORM) | | | +| DC_QUANT | u(8) | 8.4.22.3 | +| else if (COMPONENT_MODE == SEPARATE) { | | | +| DC_QUANT_LUMA | u(8) | 8.4.22.4 | +| DC_QUANT_CHROMA | u(8) | 8.4.22.5 | +| } else if (COMPONENT_MODE == INDEPENDENT) | | | +| for (i = 0; i < NumComponents; i++) | | | +| DC_QUANT_CH[i] | u(8) | 8.4.22.6 | +| } | | | + +NOTE – This function, DC\_QP(), is called from two locations: IMAGE\_PLANE\_HEADER or TILE\_HEADER\_DC. Care should be taken to use the correct value of DC\_QUANT\_CH[] when quantization parameters vary on a per tile basis. + +### 8.4.22.2 COMPONENT\_MODE + +COMPONENT\_MODE is a 2-bit syntax element that is present if NumComponents > 1, and specifies whether the colour components use or do not use the same QP set across components as specified in subclauses 8.4.22, 8.4.23 and 8.4.24. If NumComponents = 1, the value of COMPONENT\_MODE is inferred to be UNIFORM. + +**Table 33 – COMPONENT\_MODE** + +| Value | COMPONENT_MODE | +|-------|----------------| +| 0 | UNIFORM | +| 1 | SEPARATE | +| 2 | INDEPENDENT | +| 3 | RESERVED | + +### 8.4.22.3 DC\_QUANT + +DC\_QUANT is an 8-bit syntax element that is present if COMPONENT\_MODE is equal to UNIFORM. In this case, the value of the DC QP for all the colour components shall be set to DC\_QUANT. + +### 8.4.22.4 DC\_QUANT\_LUMA + +DC\_QUANT\_LUMA is an 8-bit syntax element that is present if COMPONENT\_MODE is equal to SEPARATE. In this case, the value of the DC QP for the luma component shall be set to DC\_QUANT\_LUMA. + +### 8.4.22.5 DC\_QUANT\_CHROMA + +DC\_QUANT\_CHROMA is an 8-bit syntax element that is present if COMPONENT\_MODE is equal to SEPARATE. In this case, the value of the DC QP for the chroma components shall be set to DC\_QUANT\_CHROMA. + +### 8.4.22.6 DC\_QUANT\_CH[i] + +DC\_QUANT\_CH[i] is an 8-bit syntax element that is present if COMPONENT\_MODE is equal to INDEPENDENT. In this case, the value of the DC QP for the i-th colour component shall be set to DC\_QUANT\_CH[i]. + +## 8.4.23 LP\_QP() + +### 8.4.23.1 Syntax structure + +The LP\_QP() syntax structure is specified in Table 34. + +**Table 34 – LP\_QP() syntax structure** + +| LP_QP() { | Descriptor | Reference | +|-------------------------------------------|------------|-----------| +| for (q = 0; q < NumLPQPs; q++) { | | | +| if (NumComponents != 1) | | | +| COMPONENT_MODE | u(2) | 8.4.22.2 | +| if (COMPONENT_MODE == UNIFORM) | | | +| LP_QUANT[q] | u(8) | 8.4.23.2 | +| else if (COMPONENT_MODE == SEPARATE) { | | | +| LP_QUANT_LUMA[q] | u(8) | 8.4.23.3 | +| LP_QUANT_CHROMA[q] | u(8) | 8.4.23.4 | +| } else if (COMPONENT_MODE == INDEPENDENT) | | | +| for (i = 0; i < NumComponents; i++) | | | +| LP_QUANT_CH[i][q] | u(8) | 8.4.23.5 | +| } | | | +| } | | | + +NOTE – This function, LP\_QP(), is called from two locations: IMAGE\_PLANE\_HEADER or TILE\_HEADER\_LOWPASS. Care should be taken to use the correct value of LP\_QUANT\_CH[ ][ ] when quantization parameters vary on a per tile basis. + +### 8.4.23.2 LP\_QUANT[q] + +LP\_QUANT[q] is an 8-bit syntax element that is present if COMPONENT\_MODE is equal to UNIFORM. In this case, the value of the q-th LP QP for all the colour components shall be set to LP\_QUANT[q]. + +### 8.4.23.3 LP\_QUANT\_LUMA[q] + +LP\_QUANT\_LUMA[q] is an 8-bit syntax element that is present if COMPONENT\_MODE is equal to SEPARATE. In this case, the value of the q-th LP QP for the luma component shall be set to LP\_QUANT\_LUMA[q]. + +### 8.4.23.4 LP\_QUANT\_CHROMA[q] + +LP\_QUANT\_CHROMA[q] is an 8-bit syntax element that is present if COMPONENT\_MODE is equal to SEPARATE. In this case, the value of the q-th LP QP for the chroma components shall be set to LP\_QUANT\_CHROMA[q]. + +### 8.4.23.5 LP\_QUANT\_CH[i][q] + +LP\_QUANT\_CH[i][q] is an 8-bit syntax element that is present if COMPONENT\_MODE is equal to INDEPENDENT. In this case, the value of the q-th LP QP for the i-th colour component shall be set to LP\_QUANT\_CH[i][q]. + +## 8.4.24 HP\_QP() + +### 8.4.24.1 Syntax structure + +The HP\_QP() syntax structure is specified in Table 35. + +Table 35 – HP\_QP() syntax structure + +| HP_QP() { | Descriptor | Reference | +|-------------------------------------------|------------|-----------| +| for (q = 0; q < NumHPQPs; q++) { | | | +| if (NumComponents != 1) | | | +| COMPONENT_MODE | u(2) | 8.4.22.2 | +| if (COMPONENT_MODE == UNIFORM) | | | +| HP_QUANT[q] | u(8) | 8.4.24.2 | +| else if (COMPONENT_MODE == SEPARATE) { | | | +| HP_QUANT_LUMA[q] | u(8) | 8.4.24.3 | +| HP_QUANT_CHROMA[q] | u(8) | 8.4.24.4 | +| } else if (COMPONENT_MODE == INDEPENDENT) | | | +| for (i = 0; i < NumComponents; i++) | | | +| HP_QUANT_CH[i][q] | u(8) | 8.4.24.5 | +| } | | | +| } | | | + +NOTE – This function, HP\_QP(), is called from two locations: IMAGE\_PLANE\_HEADER or TILE\_HEADER\_HIGHPASS. Care should be taken to use the correct value of HP\_QUANT\_CH[ ][ ] when quantization parameters vary on a per tile basis. + +### 8.4.24.2 HP\_QUANT[q] + +HP\_QUANT[q] is an 8-bit syntax element that is present if COMPONENT\_MODE is equal to UNIFORM. In this case, the value of the q-th HP QP for all the colour components shall be set to HP\_QUANT[q]. + +### 8.4.24.3 HP\_QUANT\_LUMA[q] + +HP\_QUANT\_LUMA[q] is an 8-bit syntax element that is present if COMPONENT\_MODE is equal to SEPARATE. In this case, the value of the q-th HP QP for the luma component shall be set to HP\_QUANT\_LUMA[q]. + +### 8.4.24.4 HP\_QUANT\_CHROMA[q] + +HP\_QUANT\_CHROMA[q] is an 8-bit syntax element that is present if COMPONENT\_MODE is equal to SEPARATE. In this case, the value of the q-th HP QP for the chroma components shall be set to HP\_QUANT\_CHROMA[q]. + +### 8.4.24.5 HP\_QUANT\_CH[i][q] + +HP\_QUANT\_CH[i][q] is an 8-bit syntax element that is present if COMPONENT\_MODE is equal to INDEPENDENT. In this case, the value of the q-th HP QP for the i-th colour component shall be set to HP\_QUANT\_CH[i][q]. + +## 8.5 INDEX\_TABLE\_TILES() + +### 8.5.1 Syntax structure + +The INDEX\_TABLE\_TILES() syntax structure is specified in Table 36. + +**Table 36 – INDEX\_TABLE\_TILES() syntax structure** + +| INDEX_TABLE_TILES() { | Descriptor | Reference | +|------------------------------------------------------------------------------------------------------------|------------|-----------| +| if (FREQUENCY_MODE_CODESTREAM_FLAG == FALSE) | | | +| valueNumIndexTableEntries = (NUM_HOR_TILES_MINUS1 + 1) *
(NUM_VER_TILES_MINUS1 + 1) | | | +| else /* FREQUENCY_MODE_CODESTREAM_FLAG == TRUE */ | | | +| valueNumIndexTableEntries = (NUM_HOR_TILES_MINUS1 + 1) *
(NUM_VER_TILES_MINUS1 + 1) * NumBandsOfPrimary | | | +| INDEX_TABLE_STARTCODE | u(16) | 8.5.2 | +| for (n = 0; n < valueNumIndexTableEntries; n++) | | | +| IndexOffsetTile[n] = VLW_ESC() | | 8.5.3 | +| } | | | + +### 8.5.2 INDEX\_TABLE\_STARTCODE + +INDEX\_TABLE\_STARTCODE is a 16-bit syntax element which indicates the start of the INDEX\_TABLE\_TILES(). This element shall have the value 0x0001. Other values of INDEX\_TABLE\_STARTCODE are reserved. + +### 8.5.3 IndexOffsetTile[n] + +IndexOffsetTile[n] is a variable that specifies the offset of the n-th tile packet from the start of the coded image data. The value of this variable is determined by a VLW\_ESC() syntax structure. + +The ordering of this information is as follows. Index offset elements corresponding to each tile shall be consecutively ordered in low-to-high order of the frequency, i.e., DC followed by lowpass, highpass, and flexbits. IndexOffsetTile entries are ordered in the raster scan order of the respective tiles, i.e. left-to-right for the top row of the tile, followed by left-to-right for the next row, and so on through to the bottom row of the tile. + +For spatial mode codestreams, only one IndexOffsetTile is sent per tile. For images with missing sub-bands (such as when BANDS\_PRESENT is not equal to ALL), Index Offset elements are sent only for the sub-bands that are present. An example of this syntax element for an image with four spatial tiles and two frequency bands (DC and LP, i.e. BANDS\_PRESENT is equal to NOHIGHPASS) is specified below. Here, pDCTile[n] and pLPTile[n] are the index offset elements of the DC and LP bands of tile n: + +pDCTile[0] pLPTile[0] pDCTile[1] pLPTile[1] pDCTile[2] pLPTile[2] pDCTile[3] pLPTile[3] + +When the number of tile packets is 1, the index offset of the only packet is 0. + +## 8.6 PROFILE\_LEVEL\_INFO() + +### 8.6.1 Syntax structure + +The PROFILE\_LEVEL\_INFO() syntax structure is specified in Table 37. + +**Table 37 – PROFILE\_LEVEL\_INFO() syntax structure** + +| PROFILE_LEVEL_INFO() { | Descriptor | Reference | +|--------------------------------------------------|------------|-----------| +| numBytes = 0 | | | +| for (iLast = 0; iLast == 0; iLast = LAST_FLAG) { | | | +| PROFILE_IDC | u(8) | 8.6.2 | +| LEVEL_IDC | u(8) | 8.6.3 | +| RESERVED_L | u(15) | 8.6.4 | +| LAST_FLAG | u(1) | 8.6.5 | +| numBytes += 4 | | | +| } | | | +| return numBytes | | | +| } | | | + +## 8.6.2 PROFILE\_IDC + +PROFILE\_IDC (when present) is an 8-bit syntax element. When present, the values of PROFILE\_IDC and LEVEL\_IDC indicate a set of profile and level constraints as specified in Annex B. + +## 8.6.3 LEVEL\_IDC + +LEVEL\_IDC (when present) is an 8-bit syntax element. When present, the values of PROFILE\_IDC and LEVEL\_IDC indicate a set of profile and level constraints as specified in Annex B. + +## 8.6.4 RESERVED\_L + +RESERVED\_L is a 15-bit syntax element. When present, the value of RESERVED\_L shall be equal to 0. Other values are reserved. Decoders shall ignore the value of this syntax element. + +NOTE – The purpose of the specification for decoders to ignore the value of RESERVED\_L is to enable the future definition of a backward-compatible usage of different values of this syntax element. + +No particular combination of PROFILE\_IDC, LEVEL\_IDC, and RESERVED\_L shall appear more than once in the PROFILE\_LEVEL\_INFO( ) syntax structure. + +## 8.6.5 LAST\_FLAG + +LAST\_FLAG (when present) is a 1-bit syntax element. It indicates whether the preceding PROFILE\_IDC, LEVEL\_IDC, and RESERVED\_L syntax elements are the last such syntax elements in the PROFILE\_LEVEL\_INFO( ) syntax structure. + +## 8.7 CODED\_TILES() + +### 8.7.1 Syntax structure + +The CODED\_TILES( ) syntax structure is specified in Table 38. + +**Table 38 – CODED\_TILES( ) syntax structure** + +| CODED_TILES( ) { | Descriptor | Reference | +|------------------------------------------------------------------------------------|-------------------|------------------| +| if (FREQUENCY_MODE_CODESTREAM_FLAG == FALSE) | | | +| for (n = 0; n < (NUM_HOR_TILES_MINUS1 + 1) *
(NUM_VER_TILES_MINUS1 + 1); n++) { | | | +| NumMBInCurrentTile = NumMBInTile[n] | | | +| POS_SEEK(IndexOffsetTile[n]) | | | +| TILE_SPATIAL( ) | | 8.7.2 | +| } | | | +| else { /* FREQUENCY_MODE_CODESTREAM_FLAG == TRUE */ | | | +| for (n = 0; n < (NUM_HOR_TILES_MINUS1 + 1) *
(NUM_VER_TILES_MINUS1 + 1); n++) { | | | +| NumMBInCurrentTile = NumMBInTile[n] | | | +| POS_SEEK(IndexOffsetTile[n * NumBandsOfPrimary]) | | | +| TILE_DC( ) | | 8.7.3 | +| } | | | +| if (NumBandsOfPrimary > 1) | | | +| for (n = 0; n < (NUM_HOR_TILES_MINUS1 + 1) *
(NUM_VER_TILES_MINUS1 + 1); n++) { | | | +| NumMBInCurrentTile = NumMBInTile[n] | | | +| POS_SEEK(IndexOffsetTile[n * NumBandsOfPrimary + 1]) | | | +| TILE_LOWPASS( ) | | 8.7.5 | +| } | | | +| if (NumBandsOfPrimary > 2) | | | +| for (n = 0; n < (NUM_HOR_TILES_MINUS1 + 1) *
(NUM_VER_TILES_MINUS1 + 1); n++) { | | | +| NumMBInCurrentTile = NumMBInTile[n] | | | +| POS_SEEK(IndexOffsetTile[n * NumBandsOfPrimary + 2]) | | | +| TILE_HIGHPASS( ) | | 8.7.7 | +| } | | | +| if (NumBandsOfPrimary > 3) | | | +| for (n = 0; n < (NUM_HOR_TILES_MINUS1 + 1) *
(NUM_VER_TILES_MINUS1 + 1); n++) { | | | +| NumMBInCurrentTile = NumMBInTile[n] | | | +| POS_SEEK(IndexOffsetTile[n * NumBandsOfPrimary + 3]) | | | +| TILE_FLEXBITS( ) | | 8.7.9 | +| } | | | +| } | | | +| } | | | + +## 8.7.2 TILE\_SPATIAL() + +The TILE\_SPATIAL( ) syntax structure is specified in Table 39. + +**Table 39 – TILE\_SPATIAL( ) syntax structure** + +| TILE_SPATIAL( ) { | Descriptor | Reference | +|-----------------------------------------------------------------------------|------------|-----------| +| TILE_STARTCODE | u(24) | 8.7.10.1 | +| ARBITRARY_BYTE | u(8) | 8.7.10.2 | +| if (TRIM_FLEXBITS_FLAG) | | | +| TRIM_FLEXBITS | u(4) | 8.7.10.3 | +| IsCurrPlaneAlphaFlag = FALSE | | | +| TILE_HEADER_DC( ) | | 8.7.4 | +| if (BANDS_PRESENT != DCONLY) { /* BANDS_PRESENT of Primary Plane */ | | | +| TILE_HEADER_LOWPASS( ) | | 8.7.6 | +| if (BANDS_PRESENT != NOHIGHPASS) | | | +| TILE_HEADER_HIGHPASS( ) | | 8.7.8 | +| } | | | +| if (ALPHA_IMAGE_PLANE_FLAG) { | | | +| IsCurrPlaneAlphaFlag = TRUE | | | +| TILE_HEADER_DC( ) | | 8.7.4 | +| if (BANDS_PRESENT != DCONLY) { | | | +| /* BANDS_PRESENT of Alpha plane */ | | | +| TILE_HEADER_LOWPASS( ) | | 8.7.6 | +| if (BANDS_PRESENT != NOHIGHPASS) | | | +| TILE_HEADER_HIGHPASS( ) | | 8.7.8 | +| } | | | +| } | | | +| for (n = 0; n < NumMBInCurrentTile; n++) { | | | +| IsCurrPlaneAlphaFlag = FALSE | | | +| if (BANDS_PRESENT != DCONLY) { | | | +| if (NumLPQPs > 1 && USE_DC_QP_FLAG == FALSE) | | | +| LP_QP_INDEX[n] = DECODE_QP_INDEX(NumLPQPs) | | 8.7.10.10 | +| if (BANDS_PRESENT != NOHIGHPASS && NumHPQPs > 1 && USE_LP_QP_FLAG == FALSE) | | | +| HP_QP_INDEX[n] = DECODE_QP_INDEX(NumHPQPs) | | 8.7.10.10 | +| } | | | +| MB_DC( ) | | 8.7.11 | +| if (BANDS_PRESENT != DCONLY) { | | | +| MB_LP( ) | | 8.7.16.1 | +| if (BANDS_PRESENT != NOHIGHPASS) { | | | +| MB_CBPHP( ) | | 8.7.17.2 | +| MB_HP_FLEX( ) | | 8.7.18.3 | +| } | | | +| } | | | +| if (ALPHA_IMAGE_PLANE_FLAG) { | | | +| IsCurrPlaneAlphaFlag = TRUE | | | +| if (BANDS_PRESENT != DCONLY) { | | | +| /* BANDS_PRESENT of Alpha plane */ | | | +| if (NumLPQPs > 1 && USE_DC_QP_FLAG == FALSE) | | | +| LP_QP_INDEX[n] = DECODE_QP_INDEX(NumLPQPs) | | 8.7.10.10 | +| if (BANDS_PRESENT != NOHIGHPASS && NumHPQPs > 1 && USE_LP_QP_FLAG == FALSE) | | | +| HP_QP_INDEX[n] = DECODE_QP_INDEX(NumHPQPs) | | 8.7.10.10 | +| } | | | +| MB_DC( ) | | 8.7.11 | +| if (BANDS_PRESENT != DCONLY) { | | | +| MB_LP( ) | | 8.7.16.1 | +| if (BANDS_PRESENT != NOHIGHPASS) { | | | +| MB_CBPHP( ) | | 8.7.17.2 | +| MB_HP_FLEX( ) | | 8.7.18.3 | +| } | | | +| } | | | +| } /* for if (ALPHA_IMAGE_PLANE_FLAG) */ | | | +| } /* for (n = 0; n < NumMBInCurrentTile; n++) */ | | | +| while (!IS_BYTE_ALIGNED( )) | | | +| BYTE_ALIGNMENT_BIT | u(1) | 8.4.21 | +| } | | | + +### 8.7.3 TILE\_DC() + +The TILE\_DC() syntax structure is specified in Table 40. + +Table 40 – TILE\_DC() syntax structure + +| TILE_DC() { | Descriptor | Reference | +|--------------------------------------------|------------|-----------| +| TILE_STARTCODE | u(24) | 8.7.10.1 | +| ARBITRARY_BYTE | u(8) | 8.7.10.2 | +| IsCurrPlaneAlphaFlag = FALSE | | | +| TILE_HEADER_DC() | | 8.7.4 | +| if (ALPHA_IMAGE_PLANE_FLAG) { | | | +| IsCurrPlaneAlphaFlag = TRUE | | | +| TILE_HEADER_DC() | | 8.7.4 | +| } | | | +| for (n = 0; n < NumMBInCurrentTile; n++) { | | | +| IsCurrPlaneAlphaFlag = FALSE | | | +| MB_DC() | | 8.7.11 | +| if (ALPHA_IMAGE_PLANE_FLAG) { | | | +| IsCurrPlaneAlphaFlag = TRUE | | | +| MB_DC() | | 8.7.11 | +| } | | | +| } | | | +| while (!IS_BYTE_ALIGNED()) | | | +| BYTE_ALIGNMENT_BIT | u(1) | 8.4.21 | +| } | | | + +### 8.7.4 TILE\_HEADER\_DC() + +The TILE\_HEADER\_DC() syntax structure is specified in Table 41. + +Table 41 – TILE\_HEADER\_DC() syntax structure + +| TILE_HEADER_DC() { | Descriptor | Reference | +|-------------------------------------------|------------|-----------| +| if (DC_IMAGE_PLANE_UNIFORM_FLAG == FALSE) | | | +| DC_QP() | | 8.4.22 | +| } | | | + +## 8.7.5 TILE\_LOWPASS() + +The TILE\_LOWPASS() syntax structure is specified in Table 42. + +**Table 42 – TILE\_LOWPASS() syntax structure** + +| TILE_LOWPASS() { | Descriptor | Reference | +|--------------------------------------------------------------------------|------------|-----------| +| TILE_STARTCODE | u(24) | 8.7.10.1 | +| ARBITRARY_BYTE | u(8) | 8.7.10.2 | +| IsCurrPlaneAlphaFlag = FALSE | | | +| if (BANDS_PRESENT != DONLY) /* BANDS_PRESENT of primary image plane */ | | | +| TILE_HEADER_LOWPASS() | | 8.7.6 | +| if (ALPHA_IMAGE_PLANE_FLAG) { | | | +| IsCurrPlaneAlphaFlag = TRUE | | | +| if (BANDS_PRESENT != DONLY) /* BANDS_PRESENT of alpha image plane */ | | | +| TILE_HEADER_LOWPASS() | | 8.7.6 | +| } | | | +| for (n = 0; n < NumMBInCurrentTile; n++) { | | | +| IsCurrPlaneAlphaFlag = FALSE | | | +| if (BANDS_PRESENT != DONLY) { /* BANDS_PRESENT of primary image plane */ | | | +| if (NumLPQPs > 1 && USE_DC_QP_FLAG == FALSE) | | | +| LP_QP_INDEX[n] = DECODE_QP_INDEX(NumLPQPs) /* primary image plane */ | | 8.7.10.10 | +| MB_LP() | | 8.7.16.1 | +| } | | | +| if (ALPHA_IMAGE_PLANE_FLAG) { | | | +| IsCurrPlaneAlphaFlag = TRUE | | | +| if (BANDS_PRESENT != DONLY) { /* BANDS_PRESENT of alpha image plane */ | | | +| if (NumLPQPs > 1 && USE_DC_QP_FLAG == FALSE) | | | +| LP_QP_INDEX[n] = DECODE_QP_INDEX(NumLPQPs) /* alpha image plane */ | | 8.7.10.10 | +| MB_LP() | | 8.7.16.1 | +| } | | | +| } | | | +| } | | | +| while (!IS_BYTE_ALIGNED()) | | | +| BYTE_ALIGNMENT_BIT | u(1) | 8.4.21 | +| } | | | + +## 8.7.6 TILE\_HEADER\_LOWPASS() + +The TILE\_HEADER\_LOWPASS() syntax structure is specified in Table 43. + +**Table 43 – TILE\_HEADER\_LOWPASS() syntax structure** + +| TILE_HEADER_LOWPASS() { | Descriptor | Reference | +|---------------------------------------------|------------|-----------| +| if (LP_IMAGE_PLANE_UNIFORM_FLAG == FALSE) { | | | +| USE_DC_QP_FLAG | u(1) | 8.7.10.4 | +| if (USE_DC_QP_FLAG) | | | +| NumLPQPs = 1 | | | +| else { | | | +| NUM_LP_QPS_MINUS1 | u(4) | 8.7.10.5 | +| NumLPQPs = NUM_LP_QPS_MINUS1 + 1 | | | +| LP_QP() | | 8.4.23 | +| } | | | +| } | | | +| } | | | + +### 8.7.7 TILE\_HIGHPASS() + +The TILE\_HIGHPASS() syntax structure is specified in Table 44. + +**Table 44 – TILE\_HIGHPASS() syntax structure** + +| TILE_HIGHPASS() { | Descriptor | Reference | +|-------------------------------------------------------------------------------------------------------------|-------------------|------------------| +| TILE_STARTCODE | u(24) | 8.7.10.1 | +| ARBITRARY_BYTE | u(8) | 8.7.10.2 | +| IsCurrPlaneAlphaFlag = FALSE | | | +| if (BANDS_PRESENT != DONLY &&
BANDS_PRESENT != NOHIGHPASS)
/* BANDS_PRESENT of primary image plane */ | | | +| TILE_HEADER_HIGHPASS() | | 8.7.8 | +| if (ALPHA_IMAGE_PLANE_FLAG) { | | | +| IsCurrPlaneAlphaFlag = TRUE | | | +| if (BANDS_PRESENT != DONLY &&
BANDS_PRESENT != NOHIGHPASS)
/* BANDS_PRESENT of alpha image plane */ | | | +| TILE_HEADER_HIGHPASS() | | 8.7.8 | +| } | | | +| for (n = 0; n < NumMBInCurrentTile; n++) { | | | +| IsCurrPlaneAlphaFlag = FALSE | | | +| if (BANDS_PRESENT != DONLY &&
BANDS_PRESENT != NOHIGHPASS) { | | | +| /* BANDS_PRESENT of primary image plane */ | | | +| if (NumHPQPs > 1 && USE_LP_QP_FLAG == FALSE) | | | +| HP_QP_INDEX[n] = DECODE_QP_INDEX(NumHPQPs) | | 8.7.10.10 | +| MB_CBPHP() | | 8.7.17.2 | +| MB_HP() | | 8.7.18.2 | +| } | | | +| if (ALPHA_IMAGE_PLANE_FLAG) { | | | +| IsCurrPlaneAlphaFlag = TRUE | | | +| if (BANDS_PRESENT != DONLY &&
BANDS_PRESENT != NOHIGHPASS) { | | | +| /* BANDS_PRESENT of alpha image plane */ | | | +| if (NumHPQPs > 1 && USE_LP_QP_FLAG == FALSE) | | | +| HP_QP_INDEX[n] = DECODE_QP_INDEX(NumHPQPs) | | 8.7.10.10 | +| MB_CBPHP() | | 8.7.17.2 | +| MB_HP() | | 8.7.18.2 | +| } | | | +| } | | | +| } | | | +| while (!IS_BYTE_ALIGNED()) | | | +| BYTE_ALIGNMENT_BIT | u(1) | 8.4.21 | +| } | | | + +## 8.7.8 TILE\_HEADER\_HIGHPASS() + +The TILE\_HEADER\_HIGHPASS() syntax structure is specified in Table 45. + +Table 45 – TILE\_HEADER\_HIGHPASS() syntax structure + +| TILE_HEADER_HIGHPASS() { | Descriptor | Reference | +|---------------------------------------------|------------|-----------| +| if (HP_IMAGE_PLANE_UNIFORM_FLAG == FALSE) { | | | +| USE_LP_QP_FLAG | u(1) | 8.7.10.6 | +| if (USE_LP_QP_FLAG) | | | +| NumHPQPs = NumLPQPs | | | +| else { | | | +| NUM_HP_QPS_MINUS1 | u(4) | 8.7.10.7 | +| NumHPQPs = NUM_HP_QPS_MINUS1 + 1 | | | +| HP_QP() | | 8.4.24 | +| } | | | +| } | | | +| } | | | + +## 8.7.9 TILE\_FLEXBITS() + +The TILE\_FLEXBITS() syntax structure is specified in Table 46. + +Table 46 – TILE\_FLEXBITS() syntax structure + +| TILE_FLEXBITS() { | Descriptor | Reference | +|--------------------------------------------|------------|-----------| +| TILE_STARTCODE | u(24) | 8.7.10.1 | +| ARBITRARY_BYTE | u(8) | 8.7.10.2 | +| if (TRIM_FLEXBITS_FLAG) | | | +| TRIM_FLEXBITS | u(4) | 8.7.10.3 | +| for (n = 0; n < NumMBInCurrentTile; n++) { | | | +| IsCurrPlaneAlphaFlag = FALSE | | | +| if (BANDS_PRESENT == ALL) | | | +| /* BANDS_PRESENT of primary image plane */ | | | +| MB_FLEXBITS() | | 8.7.19.1 | +| if (ALPHA_IMAGE_PLANE_FLAG) { | | | +| IsCurrPlaneAlphaFlag = TRUE | | | +| if (BANDS_PRESENT == ALL) | | | +| /* BANDS_PRESENT of alpha image plane */ | | | +| MB_FLEXBITS() | | 8.7.19.1 | +| } | | | +| } | | | +| while (!IS_BYTE_ALIGNED()) | | | +| BYTE_ALIGNMENT_BIT | u(1) | 8.4.21 | +| } | | | + +## 8.7.10 Tile-level semantics + +### 8.7.10.1 TILE\_STARTCODE + +TILE\_STARTCODE is a 24-bit syntax element that is present at the beginning of tile-level syntax structures. The value of TILE\_STARTCODE shall be equal to 0x000001. + +NOTE 1 – Decoders should check the value of TILE\_STARTCODE to ensure that it has the correct value. If some value other than 0x000001 is detected, decoders should infer the presence of an error condition. It is suggested that the subsequent data for any tiles that begin with an incorrect value of TILE\_STARTCODE should be discarded. When such an error condition is detected and the tile is not a flexbits tile-packet, it is suggested for the decoder to infer zero values for the transform coefficients in such a packet. When such an error condition is detected and the tile is a flexbits tile-packet, it is suggested for the decoder to infer zero values for all flexbits of such a tile-packet. Alternative approaches to handling such conditions may be preferable in some uses. + +NOTE 2 – There is no guarantee that a byte-aligned 24-bit pattern evaluating to 0x000001 will not occur at any other location in the codestream. Therefore, TILE\_STARTCODE can only be used to reconfirm the start of a tile in conjunction with the index table entries and not as a guaranteed indicator of the start of a tile. + +### 8.7.10.2 ARBITRARY\_BYTE + +ARBITRARY\_BYTE is an 8-bit syntax element. This syntax element may have any value. The value of this syntax element shall be ignored by the decoder. + +### 8.7.10.3 TRIM\_FLEXBITS + +TRIM\_FLEXBITS is a 4-bit syntax element that is present if TRIM\_FLEXBITS\_FLAG is equal to TRUE. Otherwise, TRIM\_FLEXBITS shall be inferred to be equal to 0. + +NOTE – The number of bits per transform coefficient that are present in the flexbits tile-packet is specified by the value of (ModelBitsMBHP[MBx][MBy][i] – TRIM\_FLEXBITS) as specified in 8.7.18.3 and 8.7.19.1. + +### 8.7.10.4 USE\_DC\_QP\_FLAG + +USE\_DC\_QP\_FLAG is a 1-bit syntax element which specifies whether the LP band uses the same QP set as the DC band. If USE\_DC\_QP\_FLAG is equal to TRUE, the values of the LP QP set are set to those of the DC band QP set; otherwise, the values of the LP QP set are explicitly specified in the codestream. When USE\_DC\_QP\_FLAG is not present, its value shall be inferred to be equal to FALSE. + +### 8.7.10.5 NUM\_LP\_QPS\_MINUS1 + +NUM\_LP\_QPS\_MINUS1 is a 4-bit syntax element that is present if LP\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to FALSE. This syntax element specifies the number of LP band QPs, per colour component in each tile, minus 1. + +### 8.7.10.6 USE\_LP\_QP\_FLAG + +USE\_LP\_QP\_FLAG is a 1-bit syntax element that specifies whether the HP band uses the same QP sets as the LP band. If USE\_LP\_QP\_FLAG is equal to TRUE, the values of the HP QP sets are set to those of the LP band QP sets; otherwise, the values of the HP QP sets are explicitly specified in the codestream. When USE\_LP\_QP\_FLAG is not present, its value shall be inferred to be equal to FALSE. + +### 8.7.10.7 NUM\_HP\_QPS\_MINUS1 + +NUM\_HP\_QPS\_MINUS1 is a 4-bit syntax element that is present if HP\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to FALSE. This syntax element specifies the number of HP band QPs, per colour component in each tile, minus 1. + +### 8.7.10.8 LP\_QP\_INDEX[n] + +LP\_QP\_INDEX[n] is a variable-length syntax element that is present when BANDS\_PRESENT is not equal to DONLY, NumLPQPs is greater than 1, and USE\_DC\_QP\_FLAG is equal to FALSE. It specifies the QP index used for the LP band of the n-th macroblock, in raster scan order, of the tile. The LP band QP for each colour component shall be derived from the q-th QP set when LP\_QP\_INDEX[n] takes the value q. The LP QP index is parsed using the syntax structure DECODE\_QP\_INDEX(). When LP\_QP\_INDEX[n] is not present, its value shall be inferred to be equal to 0. + +### 8.7.10.9 HP\_QP\_INDEX[n] + +HP\_QP\_INDEX[n] is a variable-length syntax element that is present when BANDS\_PRESENT is not equal to DONLY or NOHIGHPASS, NumHPQPs is greater than 1, and USE\_LP\_QP\_FLAG is equal to FALSE. It specifies the QP index for the HP band of the n-th macroblock, in raster scan order, of the tile. The HP band QP for each colour component shall be derived from the q-th QP set when HP\_QP\_INDEX[n] takes the value q. The HP QP index is parsed using the syntax structure DECODE\_QP\_INDEX(). When HP\_QP\_INDEX[n] is not present, its value shall be inferred as follows: + +- If USE\_LP\_QP\_FLAG is equal to TRUE, HP\_QP\_INDEX[n] shall be inferred to be equal to LP\_QP\_INDEX[n]. +- Otherwise, HP\_QP\_INDEX[n] shall be inferred to be equal to 0. + +**8.7.10.10      DECODE\_QP\_INDEX()** + +DECODE\_QP\_INDEX() is called when there is a table of quantization parameters associated with either the LP or HP band. When called, DECODE\_QP\_INDEX() returns the index into this table, that represents the quantization parameter to be used. This syntax structure takes the parameter iNumQP, which specifies the size of the relevant quantization parameter table. + +The syntax structure DECODE\_QP\_INDEX() is specified in Table 47. + +**Table 47 – DECODE\_QP\_INDEX() syntax structure** + +| DECODE_QP_INDEX(iNumQP) { | Descriptor | Reference | +|--------------------------------------------------------------------|------------|-----------| +| iBitsQPIndex[ ] = {0, 0, 1, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4} | | | +| iBits = iBitsQPIndex[iNumQP] | | | +| IS_QPINDEX_NONZERO_FLAG | u(1) | 8.7.10.11 | +| if (IS_QPINDEX_NONZERO_FLAG == FALSE) | | | +| iQPIndex = 0 | | | +| else { /* iBits > 0 as iNumQP > 1 */ | | | +| QPINDEX_REF | u(iBits) | 8.7.10.12 | +| iQPIndex = QPINDEX_REF + 1 | | | +| } | | | +| return iQPIndex | | | +| } | | | + +**8.7.10.11      IS\_QPINDEX\_NONZERO\_FLAG** + +IS\_QPINDEX\_NONZERO\_FLAG is a 1-bit syntax element. If IS\_QPINDEX\_NONZERO\_FLAG is equal to TRUE, the QP index is derived from the syntax element QPINDEX\_REF. Otherwise, the QP index is set to 0. + +**8.7.10.12      QPINDEX\_REF** + +QPINDEX\_REF is a syntax element that specifies the QP index when IS\_QPINDEX\_NONZERO\_FLAG is equal to TRUE. The value of QPINDEX\_REF shall be in the range of 0 to iNumQP–2. All other values are reserved. + +## 8.7.11 MB\_DC() + +The MB\_DC() syntax structure is specified in Table 48. + +**Table 48 – MB\_DC() syntax structure** + +| MB_DC() { | Descriptor | Reference | +|-------------------------------------------------------------------------------------------------------------------------------------------------------------|------------|-----------| +| /* IsCurrPlaneAlphaFlag is equal to TRUE for parsing alpha image plane,
and IsCurrPlaneAlphaFlag is equal to FALSE for parsing primary
image plane */ | | | +| iBand = 0 /* 0 = DC band, 1 = LP band, 2 = HP band */ | | | +| bInitializeContext = (IsMBLeftEdgeOfTileFlag && IsMBTopEdgeOfTileFlag) | | | +| if (bInitializeContext) { | | | +| InitializeDCVLC() | | 8.8.3.1 | +| InitializeModelMB(ModelDC, iBand) | | 8.12.1 | +| } | | | +| iLapMean[] = {0, 0} | | | +| if (INTERNAL_CLR_FMT == YONLY
INTERNAL_CLR_FMT == YUVK
INTERNAL_CLR_FMT == NCOMPONENT) | | | +| for (n=0; n < NumComponents; n++) { | | | +| IS_DC_CH_FLAG | u(1) | 8.7.14.1 | +| bAbsLevel = IS_DC_CH_FLAG | | | +| m = 0 | | | +| if (n != 0) | | | +| m = 1 | | | +| if (bAbsLevel) | | | +| iLapMean[m] = iLapMean[m] + 1 | | | +| bChroma = FALSE /* Luma */ | | | +| DCInput[n] =
DECODE_DC(ModelDC.MBits[m], iBand, bChroma, bAbsLevel) | | 8.7.12 | +| } | | | +| else { /* INTERNAL_CLR_FMT is not YONLY, YUVK,
or NCOMPONENT */ | | | +| VAL_DC_YUV /* Parse with VAL_DC_YUV Code table */ | e(v) | 8.7.14.2 | +| /* Luma (Y) DC Parsing */ | | | +| bAbsLevel = ((VAL_DC_YUV & 4) != 0) | | | +| if (bAbsLevel) | | | +| iLapMean[0] = iLapMean[0] + 1 | | | +| bChroma = FALSE /* i.e., Luma */ | | | +| DCInput[0] =
DECODE_DC(ModelDC.MBits[0], iBand, bChroma, bAbsLevel) | | 8.7.12 | +| /* First chroma (U) DC Parsing */ | | | +| bAbsLevel = ((VAL_DC_YUV & 2) != 0) | | | +| if (bAbsLevel) | | | +| iLapMean[1] = iLapMean[1] + 1 | | | +| bChroma = TRUE /* i.e., Chroma */ | | | +| DCInput[1] =
DECODE_DC(ModelDC.MBits[1], iBand, bChroma, bAbsLevel) | | 8.7.12 | +| /* Second chroma (V) DC Parsing */ | | | +| bAbsLevel = ((VAL_DC_YUV & 1) != 0) | | | +| if (bAbsLevel) | | | +| iLapMean[1] = iLapMean[1] + 1 /* Same index for U and V */ | | | +| bChroma = TRUE /* i.e., Chroma */ | | | +| DCInput[2] =
DECODE_DC(ModelDC.MBits[1], iBand, bChroma, bAbsLevel) | | 8.7.12 | +| } | | | +| UpdateModelMB(iLapMean[], ModelDC, iBand) | | 8.12.2 | +| bResetContext = (MBx == (LeftMBIndexOfTile[TileIndxx + 1] - 1)
(MBx - LeftMBIndexOfTile[TileIndxx]) % 16 == 0) | | | +| if (bResetContext) | | | +| AdaptDC() | | 8.8.4.1 | +| } | | | + +## 8.7.12 DECODE\_DC() + +Table 49 – DECODE\_DC() syntax structure + +| DECODE_DC(iModelBits, iBand, bChroma, bAbsLevel) { | Descriptor | Reference | +|------------------------------------------------------|---------------|-----------| +| iDC = 0 | | | +| iContext = 0 | | | +| if (bAbsLevel) | | | +| iDC = DECODE_ABS_LEVEL(iBand, bChroma, iContext) – 1 | | 8.7.13 | +| if (iModelBits) { | | | +| DC_REF | u(iModelBits) | 8.7.14.3 | +| iDCRef = DC_REF | | | +| iDC = (iDC << iModelBits) iDCRef | | | +| } | | | +| if (iDC != 0) { | | | +| SIGN_FLAG | u(1) | 8.7.14.4 | +| if (SIGN_FLAG) | | | +| iDC = –iDC | | | +| } | | | +| return iDC | | | +| } | | | + +## 8.7.13 DECODE\_ABS\_LEVEL() + +Table 50 – DECODE\_ABS\_LEVEL() syntax structure + +| DECODE_ABS_LEVEL(iBand, bChroma, iContext) { | Descriptor | Reference | +|------------------------------------------------------------------------|------------|-----------| +| /* sAdaptVLC is local instance of AdaptiveVLC data structure */ | | | +| if (iBand == 0) /* DC */ | | | +| if (bChroma) | | | +| sAdaptVLC = AbsLevelIndDCChr | | | +| else | | | +| sAdaptVLC = AbsLevelIndDCLum | | | +| else if (iBand == 1) /* LP */ | | | +| if (iContext) | | | +| sAdaptVLC = AbsLevelIndLP1 | | | +| else | | | +| sAdaptVLC = AbsLevelIndLP0 | | | +| else if (iBand == 2) /* HP */ | | | +| if (iContext) | | | +| sAdaptVLC = AbsLevelIndHP1 | | | +| else | | | +| sAdaptVLC = AbsLevelIndHP0 | | | +| iRemap[ ] = {2, 3, 4, 6, 10, 14} | | | +| iFixedLen[ ] = {0, 0, 1, 2, 2, 2} | | | +| ABS_LEVEL_INDEX /* Parse with table indexed by sAdaptVLC.TableIndex */ | ae(v) | 8.7.14.5 | +| sAdaptVLC.DiscrimVal1 += AbslevelIndexDelta[0][ABS_LEVEL_INDEX] | | Table 86 | +| if (ABS_LEVEL_INDEX < 6) { | | | +| iFixed = iFixedLen[ABS_LEVEL_INDEX] | | | +| iLevel = iRemap[ABS_LEVEL_INDEX] | | | +| if (iFixed > 0) { | | | +| LEVEL_REF | u(iFixed) | 8.7.14.6 | +| iLevel += LEVEL_REF | | | +| } | | | +| } else { /* Escape mode */ | | | +| FIXED_NUM | u(4) | 8.7.14.7 | +| iFixed = FIXED_NUM + 4 | | | +| if (iFixed == 19) { | | | +| FIXED_NUM_EXT | u(2) | 8.7.14.8 | +| iFixed += FIXED_NUM_EXT | | | +| if (iFixed == 22) { | | | +| FIXED_NUM_EXT2 | u(3) | 8.7.14.9 | +| iFixed += FIXED_NUM_EXT2 | | | + +| DECODE ABS_LEVEL(iBand, bChroma, iContext) { | Descriptor | Reference | +|----------------------------------------------|------------|-----------| +| } | | | +| } | | | +| LEVEL_REF | u(iFixed) | 8.7.14.6 | +| iLevel = 2 + (1 << iFixed) + LEVEL_REF | | | +| } | | | +| return iLevel | | | +| } | | | + +## 8.7.14 Macroblock DC() semantics + +### 8.7.14.1 IS\_DC\_CH\_FLAG + +IS\_DC\_CH\_FLAG is a 1-bit syntax element that is present if INTERNAL\_CLR\_FMT is one of YONLY, YUVK or NCOMPONENT. If IS\_DC\_CH\_FLAG is equal to TRUE, the variable-length coded part of the DC coefficient of the corresponding colour component is specified in the codestream. If IS\_DC\_CH\_FLAG is equal to FALSE, the variable-length coded part of the DC coefficient of the corresponding colour component is equal to 0. + +### 8.7.14.2 VAL\_DC\_YUV + +VAL\_DC\_YUV is a variable-length syntax element that is present if INTERNAL\_CLR\_FMT is not one of YONLY, YUVK or NCOMPONENT. The value of VAL\_DC\_YUV is a 3-bit number, which jointly specifies the zero/non-zero status of the DC coefficients of the Y, U and V, respectively (i.e., (VAL\_DC\_YUV & 4) specifies the Y, (VAL\_DC\_YUV & 2) specifies the U, and (VAL\_DC\_YUV & 1) specifies the V). The code table used in parsing VAL\_DC\_YUV is specified in Table 51. + +**Table 51 – Code table for VAL\_DC\_YUV** + +| Code | Value | +|--------|-------| +| 10 | 0 | +| 001 | 1 | +| 0000 1 | 2 | +| 0001 | 3 | +| 11 | 4 | +| 010 | 5 | +| 0000 0 | 6 | +| 011 | 7 | + +### 8.7.14.3 DC\_REF + +DC\_REF is a syntax element which specifies the FLC refinement in the DC value. The number of bits, iModelBits, needed to specify DC\_REF is computed as specified in 8.7.12. + +### 8.7.14.4 SIGN\_FLAG + +SIGN\_FLAG is a 1-bit syntax element which specifies the sign of a coefficient. If SIGN\_FLAG is equal to TRUE, the coefficient is negative. Otherwise, the coefficient is positive. + +### 8.7.14.5 ABS\_LEVEL\_INDEX + +ABS\_LEVEL\_INDEX is a variable-length syntax element that has a value in the range of 0 to 6, inclusive. This syntax element is used in the computation of the VLC-coded part of the transform coefficient. The VLC-coded part of a transform coefficient is parsed in two stages: the initial level value and the VLC refinement. If ABS\_LEVEL\_INDEX is less than 6, the initial level and the number of bits required to specify the VLC refinement are specified by this syntax element. If ABS\_LEVEL\_INDEX is equal to 6, further syntax elements are parsed to determine the initial level value and the number of bits required to specify the VLC refinement, as specified in 8.7.13. + +The coding of this syntax element uses one of two tables, adaptively determined as specified by the parsing process (see 8.8). The two code tables are specified in Table 52. + +**Table 52 – Code table for ABS\_LEVEL\_INDEX** + +| Code 0 | Code 1 | Value | +|--------|--------|-------| +| 01 | 1 | 0 | +| 10 | 01 | 1 | +| 11 | 001 | 2 | +| 001 | 0001 | 3 | +| 0001 | 00001 | 4 | +| 00000 | 000000 | 5 | +| 00001 | 000001 | 6 | + +#### 8.7.14.6 LEVEL\_REF + +LEVEL\_REF is a syntax element which specifies the VLC refinement. The number of bits, iFixed, needed to specify this syntax element is computed as specified in 8.7.13 from ABS\_LEVEL\_INDEX if ABS\_LEVEL\_INDEX is less than 6 or from FIXED\_NUM, FIXED\_NUM\_EXT and FIXED\_NUM\_EXT2 if ABS\_LEVEL\_INDEX is greater than or equal to 6. + +#### 8.7.14.7 FIXED\_NUM + +FIXED\_NUM is a 4-bit syntax element that is present if ABS\_LEVEL\_INDEX is equal to 6. It specifies the number of bits needed to specify the initial level value. + +#### 8.7.14.8 FIXED\_NUM\_EXT + +FIXED\_NUM\_EXT is a 2-bit syntax element that is present if FIXED\_NUM is equal to 15. It specifies the number of extension bits needed to specify the initial level value. + +#### 8.7.14.9 FIXED\_NUM\_EXT2 + +FIXED\_NUM\_EXT2 is a 3-bit syntax element that is present if FIXED\_NUM is equal to 15 and FIXED\_NUM\_EXT is equal to 3. It specifies the number of additional extension bits needed to specify the initial level value. + +### 8.7.15 Macroblock lowpass + +#### 8.7.16 General + +This subclause specifies the derivation of the LP coefficients of the blocks in a macroblock. The presence of non-zero entropy coded LP coefficients, i.e. coded block pattern lowpass, in a macroblock is represented by the variable iCBPLP as computed, as specified in Table 53, from the syntax elements CBPLP\_YUV1 or CBPLP\_YUV2 or CBPLP\_CH\_BIT. + +If INTERNAL\_CLR\_FMT is not equal to YUV420 or YUV422, the coded block status of the n-th colour component is specified by $((iCBPLP \gg n) \& 1)$ . If INTERNAL\_CLR\_FMT is equal to YUV420 or YUV422, the coded block status of the luma component is specified by $(iCBPLP \& 1)$ . If the coded block status bit of a component is non-zero, there can be up to 15 non-zero LP coefficients associated with that component. These coefficients are parsed by invoking the process DECODE\_BLOCK() specified in 8.7.18.5, and the inverse scanning order is determined by invoking the process AdaptiveLPScan(). + +If INTERNAL\_CLR\_FMT is equal to YUV420 or YUV422, the coded block status of the U and V component is jointly specified by $((iCBPLP \gg 1) \& 1)$ . If the coded block status bit is non-zero, the LP coefficients of U and V are parsed jointly by invoking the process DECODE\_BLOCK() specified in 8.7.18.5. The U and V coefficients are interleaved, and a fixed inverse scanning order (specified by iRemapArr and iRemapOffset) is used. If INTERNAL\_CLR\_FMT is equal to YUV420, there can be up to 3 U and 3 V coefficients and the inverse scanning order is U[1], V[1], U[2], V[2], U[3], V[3]. If INTERNAL\_CLR\_FMT is equal to YUV422, there can be up to 7 U and 7 V coefficients and the inverse scanning order is U[4], V[4], U[1], V[1], U[2], V[2], U[3], V[3], U[5], V[5], U[6], V[6]. + +The value of the LP coefficients is refined by invoking the process REFINE\_LP(), and this process is invoked irrespective of the value of iCBPLP. + +#### 8.7.16.1 MB\_LP() + +The MB\_LP() syntax structure is specified in Table 53. + +**Table 53 – MB\_LP() syntax structure** + +| MB_LP() { | Descriptor | Reference | +|----------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------|------------------| +| /* IsCurrPlaneAlphaFlag is equal to TRUE for parsing alpha image plane, and
IsCurrPlaneAlphaFlag is equal to FALSE for parsing primary image plane */ | | | +| iBand = 1 /* 0 = DC 1 = LP, 2 = HP */ | | | +| iTranspose444[] = {0, 4, 8, 12, 1, 5, 9, 13, 2, 6, 10, 14, 3, 7, 11, 15} | | | +| iTranspose422[] = {0, 2, 1, 3, 4, 6, 5, 7} | | | +| iTranspose420[] = {0, 2, 1, 3} | | | +| bInitializeContext = (IsMBLeftEdgeOfTileFlag && IsMBTopEdgeOfTileFlag) | | | +| if (bInitializeContext) { | | | +| InitializeCountCBPLP() | | 8.9.2 | +| InitializeLPVLC() | | 8.8.3.2 | +| InitializeAdaptiveScanLP() | | 8.11.2 | +| InitializeModelMB(ModelLP, iBand) | | 8.12.1 | +| } | | | +| bResetTotals = ((MBx - LeftMBIndexOfTile[TileIndexx]) % 16) == 0) | | | +| if (bResetTotals) | | | +| ResetTotalsAdaptiveScanLP() | | 8.11.4 | +| iLapMean[] = {0, 0} | | | +| if (INTERNAL_CLR_FMT == YUV422
INTERNAL_CLR_FMT == YUV420) | | | +| iFullPlanes = 2 | | | +| else | | | +| iFullPlanes = NumComponents | | | +| if (INTERNAL_CLR_FMT == YUV420
INTERNAL_CLR_FMT == YUV422
INTERNAL_CLR_FMT == YUV444) { | | | +| iMax = iFullPlanes * 4 - 5 /* Max value of CBPLP */ | | | +| if (CountZeroCBPLP <= 0 CountMaxCBPLP < 0) { | | | +| CBPLP_YUV1 | e(v) | 8.7.16.3.1 | +| if (CountMaxCBPLP < CountZeroCBPLP) | | | +| iCBPLP = iMax - CBPLP_YUV1 | | | +| else | | | +| iCBPLP = CBPLP_YUV1 | | | +| } else { | | | +| CBPLP_YUV2 | u(iFullPlanes) | 8.7.16.3.2 | +| iCBPLP = CBPLP_YUV2 | | | +| } | | | +| UpdateCountCBPLP(iCBPLP, iMax) | | 8.9.3 | +| } else { | | | +| iCBPLP = 0 | | | +| for (n=0; n < NumComponents; n++) { | | | +| CBPLP_CH_BIT | u(1) | 8.7.16.3.3 | +| iCBPLP = (CBPLP_CH_BIT << n) | | | +| } | | | +| } | | | +| for (n = 0; n < NumComponents; n++) { | | | +| if (INTERNAL_CLR_FMT == YUV420) | | | +| jMax = 3 | | | +| else if (INTERNAL_CLR_FMT == YUV422) | | | +| jMax = 7 | | | +| else | | | +| jMax = 15 | | | +| for (j = 0; j <= jMax; j++) | | | +| LPInput[k][j] = 0 | | | +| } | | | +| for (n = 0; n < iFullPlanes; n++) { | | | +| if (n == 0) | | | +| iIndex = 0 | | | +| else | | | +| iIndex = 1 | | | +| iNumNonZero = 0 | | | +| if ((iCBPLP >> n) & 1) { | | | +| for (i = 0; i < 32; i++) | | | + +| MB_LP() { | Descriptor | Reference | +|---------------------------------------------------------------------------------------|------------|-----------| +| iRLCoeffs[i] = 0 | | | +| iLocation = 1 | | | +| if ((INTERNAL_CLR_FMT == YUV420) && n) | | | +| iLocation = 10 | | | +| if ((INTERNAL_CLR_FMT == YUV422) && n) | | | +| iLocation = 2 | | | +| iNumNonZero =
DECODE_BLOCK(iIndex, iRLCoeffs[ ], iBand, iLocation) | | 8.7.18.5 | +| if ((INTERNAL_CLR_FMT == YUV420
INTERNAL_CLR_FMT == YUV422) && n) { | | | +| iTemp[14] = 0 /* Initializing the array iTemp to zero. */ | | | +| iRemapArr[ ] = {4, 1, 2, 3, 5, 6, 7} | | | +| iRemapOffset = 0 | | | +| if (INTERNAL_CLR_FMT == YUV420) | | | +| iRemapOffset = 1 | | | +| if (INTERNAL_CLR_FMT == YUV422) | | | +| iCountChr = 14 | | | +| else | | | +| iCountChr = 6 | | | +| i = 0 | | | +| for (k = 0; k < iNumNonZero; k++) { | | | +| i += iRLCoeffs[k * 2] | | | +| iTemp[i] = iRLCoeffs[k * 2 + 1] | | | +| i++ | | | +| } | | | +| for (k = 0; k < iCountChr; k++) { | | | +| iRemap = iRemapArr[(k >> 1) + iRemapOffset] | | | +| if (INTERNAL_CLR_FMT == YUV420) | | | +| LPInput[(k & 1) + 1][iTranspose420[iRemap]] = iTemp[k] | | | +| else | | | +| LPInput[(k & 1) + 1][iTranspose422[iRemap]] = iTemp[k] | | | +| } | | | +| } else { | | | +| i = 1 | | | +| for (k = 0; k < iNumNonZero; k++) { | | | +| i += iRLCoeffs[k*2] | | | +| AdaptiveLPScan(n, i, iRLCoeffs[k * 2 + 1]) /* Updates LPInput */ | | 8.11.6 | +| i++ | | | +| } | | | +| } | | | +| } /* if ((iCBPLP >> n) & 1) */ | | | +| iModelBits = ModelLP.MBits[iIndex] | | | +| iLapMean[iIndex] += iNumNonZero | | | +| if (iModelBits) | | | +| if ((INTERNAL_CLR_FMT == YUV420) && n) | | | +| for (k = 1; k < 4; k++) { | | | +| LPInput[1][iTranspose420[k]] =
REFINE_LP(LPInput[1][iTranspose420[k]], iModelBits) | | 8.7.16.2 | +| LPInput[2][iTranspose420[k]] =
REFINE_LP(LPInput[2][iTranspose420[k]], iModelBits) | | 8.7.16.2 | +| } | | | +| else if ((INTERNAL_CLR_FMT == YUV422) && n) | | | +| for (k = 1; k < 8; k++) { | | | +| LPInput[1][iTranspose422[k]] =
REFINE_LP(LPInput[1][iTranspose422[k]], iModelBits) | | 8.7.16.2 | +| LPInput[2][iTranspose422[k]] =
REFINE_LP(LPInput[2][iTranspose422[k]], iModelBits) | | 8.7.16.2 | +| } | | | +| else | | | +| for (k = 1; k < 16; k++) | | | +| LPInput[n][iTranspose444[k]] =
REFINE_LP(LPInput[n][iTranspose444[k]], iModelBits) | | 8.7.16.2 | +| } /* for (n=0 ... */ | | | +| UpdateModelMB(iLapMean[ ], ModelLP, iBand) | | 8.12.2 | + +| MB_LP() { | Descriptor | Reference | +|---------------------------------------------------------------------------------------------------------------------|-------------------|------------------| +| bResetContext = (MBx == (LeftMBIndexOfTile[TileIndexx + 1] - 1) (MBx - LeftMBIndexOfTile[TileIndexx]) % 16 == 0) | | | +| if (bResetContext) | | | +| AdaptLP() | | 8.8.4.2 | +| } | | | + +### 8.7.16.2 REFINE\_LP() + +The REFINE\_LP() syntax structure is specified in Table 54. + +**Table 54 – REFINE\_LP() syntax structure** + +| REFINE_LP(iCoeff, iModelBits) { | Descriptor | Reference | +|----------------------------------------|-------------------|------------------| +| COEFF_REF | u(iModelBits) | 8.7.16.3.4 | +| if (iCoeff > 0) { | | | +| iCoeff <<= iModelBits | | | +| iCoeff += COEFF_REF | | | +| } else if (iCoeff < 0) { | | | +| iCoeff <<= iModelBits | | | +| iCoeff -= COEFF_REF | | | +| } else { | | | +| iCoeff = COEFF_REF | | | +| if (iCoeff) { | | | +| SIGN_FLAG | u(1) | 8.7.14.4 | +| if (SIGN_FLAG) | | | +| iCoeff = -iCoeff | | | +| } | | | +| } | | | +| return iCoeff | | | +| } | | | + +### 8.7.16.3 MB\_LP() and REFINE\_LP() semantics + +#### 8.7.16.3.1 CBPLP\_YUV1 + +CBPLP\_YUV1 is a syntax element that is present if INTERNAL\_CLR\_FMT is one of YUV420, YUV422 or YUV444, and also CountZeroCBPLP is less than or equal to 0 or CountMaxCBPLP is less than 0; it jointly specifies the coded block pattern lowpass of the Y, U and V colour components as follows: + +- if INTERNAL\_CLR\_FMT is YUV444, the parsing of CBPLP\_YUV1 is specified in Table 55: +- if INTERNAL\_CLR\_FMT is YUV420 or YUV422, the parsing of CBPLP\_YUV1 is specified in Table 56. + +NOTE – If (CountZeroCBPLP > 0 && CountMaxCBPLP >= 0), the coded block pattern lowpass band is computed as specified in 8.7.16.1. + +**Table 55 – Code table for CBPLP\_YUV1 when INTERNAL\_CLR\_FMT is equal to YUV444** + +| Code | Value | +|-------------|--------------| +| 0 | 0 | +| 100 | 1 | +| 1010 | 2 | +| 1011 | 3 | +| 1100 | 4 | +| 1101 | 5 | +| 1110 | 6 | +| 1111 | 7 | + +**Table 56 – Code table for CBPLP\_YUV1 when INTERNAL\_CLR\_FMT is equal to YUV420 or YUV422** + +| Code | Value | +|-------------|--------------| +| 0 | 0 | +| 10 | 1 | +| 110 | 2 | +| 111 | 3 | + +### 8.7.16.3.2 CBPLP\_YUV2 + +CBPLP\_YUV2 is a syntax element that is present when INTERNAL\_CLR\_FMT is equal to YUV420, YUV422 or YUV444, and CountZeroCBPLP is greater than 0 and CountMaxCBPLP is greater than or equal to 0. The number of bits required to specify this syntax element is specified by iFullPlanes. + +### 8.7.16.3.3 CBPLP\_CH\_BIT + +CBPLP\_CH\_BIT is a 1-bit syntax element that is present for each colour component in an image when INTERNAL\_CLR\_FMT is not one of YUV422, YUV420 or YUV444. It specifies the coded block pattern lowpass of the corresponding colour component. If CBPLP\_CH\_BIT is equal to 0, all the coefficients in the LP band for this macroblock of the corresponding colour component are set to the value 0. If CBPLP\_CH\_BIT is equal to 1, the LP band for this macroblock of the corresponding component is non-zero. + +### 8.7.16.3.4 COEFF\_REF + +COEFF\_REF is a syntax element that refines the value of LP coefficients. The number of bits used to parse this syntax element is specified by iModelBits. + +## 8.7.17 Coded block pattern highpass (CBPHP) + +### 8.7.17.1 General + +The CBPHP derivation process is hierarchical, and proceeds as follows. + +First step: the syntax element NUM\_CBPHP and REFINE\_CBPHP() process specify the residual CBPHP status of block groups where each block group consists of multiple blocks as specified in the following. + +If INTERNAL\_CLR\_FMT is equal to YUV444, YUV422 or YUV420, there is a NUM\_CBPHP syntax element for each macroblock and each block group consists of $2 \times 2$ group of luma blocks, and the co-located chroma blocks. For each $2 \times 2$ group of luma block, the co-located chroma blocks consists of: a) $2 \times 2$ group of U blocks and $2 \times 2$ group of V blocks for YUV444, b) $2 \times 1$ group of U blocks and $2 \times 1$ group of V blocks for YUV422; and c) 1 U block and 1 V block for YUV420. Thus, there are 4 block groups in each macroblock. NUM\_CBPHP takes a value between 0 and 4 and specifies the number of block groups where CBPHP residual values are non-zero, i.e. block groups that have CBPHP status that differ from their predicted values. The REFINE\_CBPHP() process is invoked to determine which of the block groups has non-zero residual CBPHP values. + +If INTERNAL\_CLR\_FMT is equal to YONLY, YUVK or NCOMPONENT, there is a NUM\_CBPHP syntax for each colour component in that macroblock, and each block group consists of $2 \times 2$ groups of blocks in that colour component. Thus, there are 4 block groups for each colour component. NUM\_CBPHP takes a value between 0 and 4 and specifies the number of block groups (in that colour component) where CBPHP residual values are non-zero, and the REFINE\_CBPHP() process is invoked to determine which of the block groups has non-zero residual CBPHP values. + +Second step: If the residual CBPHP status of a block group is equal to 0, the residual CBPHP of all the blocks in the group is inferred to be equal to 0. If the residual CBPHP status of a given block group is non-zero, the NUM\_BLKCBPHP and subsequent syntax elements are used to indicate the residual CBPHP of specific blocks in that block group as summarized in the following. + +If INTERNAL\_CLR\_FMT is equal to YUV444, YUV422 or YUV420, there is a NUM\_BLKCBPHP syntax element for each block group with non-zero residual CBPHP status. NUM\_BLKCBPHP takes a value between 0 and 8. If NUM\_BLKCBPHP plus 1 is less than 6, it indicates that the residual CBPHP of all the chroma blocks in the block group are equal to 0. The luma blocks that have non-zero residual CBPHP are indicated by the value of NUM\_BLKCBPHP and CODE\_INC. If NUM\_BLKCBPHP plus 1 is greater than or equal to 6, the residual CBPHP of at least some chroma blocks in this block group are non-zero, and the syntax elements CHR\_CBPHP is parsed to specify if a) the U or b) V or c) both U and V, colour components have blocks with non-zero residual CBPHP. In this case, the luma blocks that have non-zero residual CBPHP are indicated by the value of NUM\_BLKCBPHP, VAL\_INC and CODE\_INC. + +If INTERNAL\_CLR\_FMT is equal to YUV444 or YUV422, the chroma component with non-zero residual CBPHP has multiple blocks. If INTERNAL\_CLR\_FMT is equal to YUV444, the syntax element NUM\_CH\_BLK and the process REFINE\_CBPHP() specify the chroma blocks that have non-zero residual CBPHP. If INTERNAL\_CLR\_FMT is equal to YUV422, the syntax element CBPHP\_CH\_BLK specifies the chroma blocks that have non-zero residual CBPHP. + +If INTERNAL\_CLR\_FMT is equal to YONLY, YUVK or NCOMPONENT, there is a NUM\_BLKCBPHP syntax element for each block group (in each colour component) where residual CBPHP status is non-zero. NUM\_BLKCBPHP takes a value between 0 and 4. The blocks in this block group that have non-zero residual CBPHP are indicated by the value of NUM\_BLKCBPHP and CODE\_INC. + +Third step: On the completion of the second step for all block groups in a macroblock, the residual CBPHP values for all the blocks in colour component i are stored in the corresponding iDiffCBPHP[i] variable. These values are stored in a hierarchical raster scan order, where each consecutive nibble of 4 bits corresponds to one 2×2 block group. Within each nibble, the blocks of a block group are in raster scan order, and 2×2 block groups in a macroblock are also in raster scan order. If INTERNAL\_CLR\_FMT is equal to YUV422 or YUV420), the hierarchical scan order for the chroma components is identical to the normal scan order. + +The PredCBPHP( ) process is invoked to compute the actual CBPHP values from the residual CBPHP values. The value of ((MBCBPHP[MBx][MBy][i] >> j) & 1) specifies the coded block status of the j-th block (in the same hierarchical raster scan order as iDiffCBPHP) associated with the i-th colour component in the macroblock indexed by MBx and MBy. + +### 8.7.17.2 MB\_CBPHP() + +The MB\_CBPHP( ) syntax structure is specified in Table 57. + +**Table 57 – MB\_CBPHP() syntax structure** + +| MB_CBPHP() { | Descriptor | Reference | +|----------------------------------------------------------------------------------------------------------------------------------------------------------|---------------|-----------------------| +| /* IsCurrPlaneAlphaFlag is equal to TRUE for parsing alpha image plane, and
IsCurrPlaneAlphaFlag is equal to FALSE for parsing primary image plane */ | | | +| /* sAdaptVLC is local instance of AdaptiveVLC data structure */ | | | +| iFLC[ ] = {0, 2, 1, 2, 2, 0} | | | +| iOff[ ] = {0, 4, 2, 8, 12, 1} | | | +| iOut[ ] = {0, 15, 3, 12, 1, 2, 4, 8, 5, 6, 9, 10, 7, 11, 13, 14} | | | +| iDiffCBPHP[NumComponents] = 0 /* Initializing the array to zero */ | | | +| bInitializeContext =
(IsMBLeftEdgeOfTileFlag && IsMBTopEdgeOfTileFlag) | | | +| if (bInitializeContext) | | | +| InitializeCBPHPVLC() | | 8.8.3.4 | +| if (INTERNAL_CLR_FMT == YUVK
INTERNAL_CLR_FMT == NCOMPONENT) | | | +| iComponent = NumComponents | | | +| else | | | +| iComponent = 1 | | | +| for (i = 0; i < iComponent; i++) { | | | +| sAdaptVLC = DecNumCBPHP | | | +| /* reference AdaptiveVLC struct for NUM_CBPHP */ | | | +| NUM_CBPHP /* using sAdaptVLC */ | ae(v) | 8.7.17.4.1 | +| sAdaptVLC.DiscrimVal1 +=
NumCBPHPDelta[sAdaptVLC.DeltaTableIndex][NUM_CBPHP]
/* sAdaptVLC.DeltaTableIndex is equal to 0 */ | | Table 89 | +| iCBPHP = REFINES_CBPHP(NUM_CBPHP) | | 8.7.17.3 | +| for (iBlock = 0; iBlock < 4; iBlock++) | | | +| if (iCBPHP & (1 << iBlock)) { | | | +| sAdaptVLC = DecNumBlkCBPHP | | | +| /* reference AdaptiveVLC struct for NUM_BLKCBPHP */ | | | +| NUM_BLKCBPHP /* using sAdaptVLC */ | ae(v) | 8.7.17.4.2 | +| sAdaptVLC.DiscrimVal1 +=
NumBlkCBPHPDelta[sAdaptVLC.DeltaTableIndex][NUM_BLKCBPHP] | | Table 90,
Table 91 | +| iVal = NUM_BLKCBPHP+1 | | | +| iBlkCBPHP = 0 | | | +| if (iVal >= 6) { /* Is chroma */ | | | +| CHR_CBPHP | e(v) | 8.7.17.4.3 | +| iBlkCBPHP = 0x10 * (CHR_CBPHP + 1) | | | +| if (iVal >= 9) { | | | +| VAL_INC | e(v) | 8.7.17.4.4 | +| iVal += VAL_INC | | | +| } | | | +| iVal -= 6 | | | +| } | | | +| iCode = iOff[iVal] | | | +| if (iFLC[iVal]) { | | | +| CODE_INC | u(iFLC[iVal]) | 8.7.17.4.5 | +| iCode += CODE_INC | | | +| } | | | +| iBlkCBPHP += iOut[iCode] | | | + +| MB_CBPHP() { | Descriptor | Reference | +|--------------------------------------------------------|------------|------------| +| if (INTERNAL_CLR_FMT == YUV444) { | | | +| iDiffCBPHP[0] = ((iBlkCBPHP & 0x0F) << (iBlock * 4)) | | | +| for (k = 0; k < 2; k++) | | | +| if ((iBlkCBPHP >> (k + 4)) & 0x01) { | | | +| NUM_CH_BLK | e(v) | 8.7.17.4.6 | +| iCBPHPChr = REFINE_CBPHP(NUM_CH_BLK + 1) | | 8.7.17.3 | +| iDiffCBPHP[k + 1] = (iCBPHPChr << (iBlock * 4)) | | | +| } | | | +| /* INTERNAL_CLR_FMT == YUV444 */ | | | +| } else if (INTERNAL_CLR_FMT == YUV422) { | | | +| iDiffCBPHP[0] = ((iBlkCBPHP & 0x0F) << (iBlock * 4)) | | | +| for (k = 0; k < 2; k++) | | | +| if ((iBlkCBPHP >> (k + 4)) & 0x01) { | | | +| iShift[4] = {0, 1, 4, 5} | | | +| CBPHP_CH_BLK | e(v) | 8.7.17.4.7 | +| iCBPHPChr = iShift[CBPHP_CH_BLK + 1] | | | +| iDiffCBPHP[k + 1] = (iCBPHPChr << iShift[iBlock]) | | | +| } | | | +| } else if (INTERNAL_CLR_FMT == YUV420) { | | | +| iDiffCBPHP[0] = ((iBlkCBPHP & 0x0F) << (iBlock * 4)) | | | +| iDiffCBPHP[1] = (((iBlkCBPHP >> 4) & 0x01) << iBlock) | | | +| iDiffCBPHP[2] = (((iBlkCBPHP >> 5) & 0x01) << iBlock) | | | +| } else /* Default */ | | | +| iDiffCBPHP[i] = ((iBlkCBPHP) << (iBlock * 4)) | | | +| } /* if (iCBPHP...) */ | | | +| } /* i */ | | | +| PredCBPHP(iDiffCBPHP) | | 8.7.17.5.1 | +| } | | | + +### 8.7.17.3 REFINE\_CBPHP() + +The REFINE\_CBPHP() syntax structure is specified in Table 58. + +**Table 58 – REFINE\_CBPHP() syntax structure** + +| REFINE_CBPHP(iNum) { | Descriptor | Reference | +|----------------------------------|------------|------------| +| if (iNum == 2) { | | | +| REF_CBPHP1 | e(v) | 8.7.17.4.8 | +| iRef = REF_CBPHP1 | | | +| } else if (iNum == 1) { | | | +| REF_CBPHP | u(2) | 8.7.17.4.9 | +| iRef = (1 << REF_CBPHP) | | | +| } else if (iNum == 3) { | | | +| REF_CBPHP | u(2) | 8.7.17.4.9 | +| iRef = (0x0F ^ (1 << REF_CBPHP)) | | | +| } else if (iNum == 4) | | | +| iRef = 0x0F | | | +| else | | | +| iRef = 0 | | | +| return iRef | | | +| } | | | + +### 8.7.17.4 MB\_CBPHP() and REFINE\_CBPHP() semantics + +#### 8.7.17.4.1 NUM\_CBPHP + +NUM\_CBPHP is a variable syntax element that specifies the number of block groups where CBPHP residual values CBPHP status differs from their predicted values as specified in 8.7.17.1. NUM\_CBPHP is parsed using one of two VLC tables specified in Table 59. The adaptive VLC structure used to parse NUM\_CBPHP is initialized to the VLC table corresponding to Code 0 as specified in 8.8.3.4, and the structure is updated as specified in 8.8.4. + +**Table 59 – Code table for NUM\_CBPHP()** + +| Code 0 | Code 1 | Value | +|--------|--------|-------| +| 1 | 1 | 0 | +| 01 | 000 | 1 | +| 001 | 001 | 2 | +| 0000 | 010 | 3 | +| 0001 | 011 | 4 | + +**8.7.17.4.2 NUM\_BLKCBPHP** + +NUM\_BLKCBPHP is a variable-length syntax element that specifies the CBPHP status of each block group where residual CBPHP status is non-zero as specified in 8.7.17.1. If INTERNAL\_CLR\_FMT is equal to YUVK, NCOMPONENT or YONLY, NUM\_BLKCBPHP is coded using one of the two VLC tables specified in Table 60. Otherwise, NUM\_BLKCBPHP is parsed using one of the two VLC tables specified in Table 61. The adaptive VLC structure used to parse NUM\_BLKCBPHP is initialized to the VLC table corresponding to Code 0 as specified in 8.8.3.4, and the structure is updated as specified in 8.8.4. + +**Table 60 – Code table for NUM\_BLKCBPHP** +**if INTERNAL\_CLR\_FMT is one of {YUVK, NCOMPONENT, YONLY}** + +| Code 0 | Code 1 | Value | +|--------|--------|-------| +| 1 | 1 | 0 | +| 01 | 000 | 1 | +| 001 | 001 | 2 | +| 0000 | 010 | 3 | +| 0001 | 011 | 4 | + +**Table 61 – Code table for NUM\_BLKCBPHP** +**if INTERNAL\_CLR\_FMT is not one of {YUVK, NCOMPONENT, YONLY}** + +| Code 0 | Code 1 | Value | +|--------|---------|-------| +| 010 | 1 | 0 | +| 00000 | 001 | 1 | +| 0010 | 010 | 2 | +| 00001 | 0001 | 3 | +| 00010 | 000001 | 4 | +| 1 | 011 | 5 | +| 011 | 00001 | 6 | +| 00011 | 0000000 | 7 | +| 0011 | 0000001 | 8 | + +**8.7.17.4.3 CHR\_CBPHP** + +CHR\_CBPHP is a syntax element that specifies the chroma components have non-zero CBPHP in a block group as specified in 8.7.17.1. The VLC used to parse CHR\_CBPHP is specified in Table 62. + +**Table 62 – Code table for CHR\_CBPHP, VAL\_INC, and CBPHP\_CH\_BLK** + +| Code | Value | +|------|-------| +| 1 | 0 | +| 01 | 1 | +| 00 | 2 | + +NOTE – Non-zero residual CBPHP in: a) U component blocks are indicated by CHR\_CBPHP = 0; b) V component blocks are indicated by CHR\_CBPHP = 1; and c) both U and V component blocks are indicated by CHR\_CBPHP = 2. + +#### 8.7.17.4.4 VAL\_INC + +VAL\_INC is a syntax element that refines the CBPHP of a block group as specified in 8.7.17.1 when NUM\_BLKCBPHP plus 1 is greater than or equal to 9. The VLC that specifies the parsing of VAL\_INC is specified in Table 62. + +#### 8.7.17.4.5 CODE\_INC + +CODE\_INC is a syntax element that specifies the location of coded blocks in a block group as specified in 8.7.17.1. The size of this syntax element is specified by iFLC[iVal], where iFLC[ ] and iVal are specified in 8.7.17.2. + +#### 8.7.17.4.6 NUM\_CH\_BLK + +When INTERNAL\_CLR\_FMT is equal to YUV444, NUM\_CH\_BLK is a syntax element that specifies the number of coded chroma blocks in a 2×2 block group as specified in 8.7.17.1. The VLC that specifies the parsing of NUM\_CH\_BLK is specified in Table 63. + +**Table 63 – Code table for NUM\_CH\_BLK** + +| Code | Value | +|------|-------| +| 1 | 0 | +| 01 | 1 | +| 000 | 2 | +| 001 | 3 | + +#### 8.7.17.4.7 CBPHP\_CH\_BLK + +When INTERNAL\_CLR\_FMT is equal to YUV422, CBPHP\_CH\_BLK is a syntax element that refines the chroma CBPHP for a block group as specified in 8.7.17.1. The VLC that specifies the parsing of CBPHP\_CH\_BLK is specified in Table 62. + +#### 8.7.17.4.8 REF\_CBPHP1 + +REF\_CBPHP1 is a variable size syntax element that refines the CBPHP of a block group as specified in 8.7.17.1. The VLC that specifies the parsing of REF\_CBPHP1 is specified in Table 64. + +**Table 64 – Code table for REF\_CBPHP1** + +| Code | Value | +|------|-------| +| 00 | 3 | +| 01 | 5 | +| 100 | 6 | +| 101 | 9 | +| 110 | 10 | +| 111 | 12 | + +#### 8.7.17.4.9 REF\_CBPHP + +REF\_CBPHP is a 2-bit syntax element that refines the CBPHP of a block group as specified in 8.7.17.1. + +#### 8.7.17.5 CBPHP prediction + +The CBPHP of neighbouring blocks is used to predict the CBPHP of current block as specified in 8.7.17.5.1. The prediction of CBPHP in each component is performed independently. The prediction of CBPHP for the U and V components in the YUV422 case is specified in 8.7.17.5.3. The prediction of CBPHP for the U and V components in the YUV420 is specified in 8.7.17.5.4. In all other cases, the prediction of CBPHP is specified in 8.7.17.5.2. After the CBPHP of the current block is reconstructed, the CBPHP prediction model is updated as specified in 8.10.2. + +##### 8.7.17.5.1 PredCBPHP() + +The pseudocode for the function PredCBPHP() is specified in Table 65. + +**Table 65 – Pseudocode for the function PredCBPHP( )** + +| PredCBPHP(iDiffCBPHP[ ] ) { | Reference | +|---------------------------------------------------------------------------|------------------| +| bInitializeContext =
(IsMBLeftEdgeOfTileFlag && IsMBTopEdgeOfTileFlag) | | +| if (bInitializeContext) | | +| InitializeCBPHPModel( ) | 8.10.1 | +| if (INTERNAL_CLR_FMT == YUV420
INTERNAL_CLR_FMT == YUV422) | | +| iComponent = 1 | | +| else | | +| iComponent = NumComponents | | +| for (i = 0; i < iComponent; i++) | | +| MBCBPHP[MBx][MBy][i] = PredCBPHP444(i, iDiffCBPHP) | 8.7.17.5.2 | +| if (INTERNAL_CLR_FMT == YUV422) { | | +| MBCBPHP[MBx][MBy][1] = PredCBPHP422(1, iDiffCBPHP) | 8.7.17.5.3 | +| MBCBPHP[MBx][MBy][2] = PredCBPHP422(2, iDiffCBPHP) | 8.7.17.5.3 | +| } else if (INTERNAL_CLR_FMT == YUV420) { | | +| MBCBPHP[MBx][MBy][1] = PredCBPHP420(1, iDiffCBPHP) | 8.7.17.5.4 | +| MBCBPHP[MBx][MBy][2] = PredCBPHP420(2, iDiffCBPHP) | 8.7.17.5.4 | +| } | | +| } | | + +### 8.7.17.5.2 PredCBPHP444( ) + +The pseudocode for the function PredCBPHP444( ) is specified in Table 66. + +**Table 66 – Pseudocode for the function PredCBPHP444( )** + +| PredCBPHP444(i, iDiffCBPHP) { | Reference | +|------------------------------------------------|------------------| +| c1 = 0 | | +| if (i > 0) | | +| c1 = 1 | | +| iCBPHP = iDiffCBPHP[i] | | +| if (CBPHPModelHP.CBPHPState[c1] == 0) { | | +| if (IsMBLeftEdgeofTileFlag) | | +| if (IsMBTopEdgeofTileFlag) | | +| iCBPHP ^= 1 | | +| else | | +| iCBPHP ^= ((MBCBPHP[MBx][MBy-1][i] >> 10) & 1) | | +| else | | +| iCBPHP ^= ((MBCBPHP[MBx-1][MBy][i] >> 5) & 1) | | +| iCBPHP ^= (0x02 & (iCBPHP << 1)) | | +| iCBPHP ^= (0x10 & (iCBPHP << 3)) | | +| iCBPHP ^= (0x20 & (iCBPHP << 1)) | | +| iCBPHP ^= ((iCBPHP & 0x33) << 2) | | +| iCBPHP ^= ((iCBPHP & 0x00CC) << 6) | | +| iCBPHP ^= ((iCBPHP & 0x3300) << 2) | | +| } else if (CBPHPModelHP.CBPHPState[c1] == 2) | | +| iCBPHP ^= 0x0000FFFF | | +| iNOrig = Numones(iCBPHP) | | +| UpdateCBPHPModel(c1, iNOrig) | 8.10.2 | +| return iCBPHP | | +| } | | + +### 8.7.17.5.3 PredCBPHP422( ) + +The pseudocode for the function PredCBPHP422( ) is specified in Table 67. + +**Table 67 – Pseudocode for the function PredCBPHP422()** + +| PredCBPHP422(i, iDiffCBPHP[] ) { | Reference | +|-----------------------------------------------|------------------| +| iCBPHP = iDiffCBPHP[i] | | +| if (CBPHPModelHP.CBPHPState[1] == 0) { | | +| if (IsMBLeftEdgeofTileFlag) | | +| if (IsMBTopEdgeofTileFlag) | | +| iCBPHP ^= 1 | | +| else | | +| iCBPHP ^= ((MBCBPHP[MBx][MBy-1][i] >> 6) & 1) | | +| else | | +| iCBPHP ^= ((MBCBPHP[MBx-1][MBy][i] >> 1) & 1) | | +| iCBPHP ^= ((iCBPHP & 0x01) << 1) | | +| iCBPHP ^= ((iCBPHP & 0x03) << 2) | | +| iCBPHP ^= ((iCBPHP & 0x0C) << 2) | | +| iCBPHP ^= ((iCBPHP & 0x30) << 2) | | +| } else if (CBPHPModelHP.CBPHPState[1] == 2) | | +| iCBPHP ^= 0x00FF | | +| iNOrig = Numones(iCBPHP) * 2 | | +| UpdateCBPHPModel(1, iNOrig) | 8.10.2 | +| return iCBPHP | | +| } | | + +#### 8.7.17.5.4PredCBPHP420( ) + +The pseudocode for the function PredCBPHP420() is specified in Table 68. + +**Table 68 – Pseudocode for the function PredCBPHP420()** + +| PredCBPHP420(i, iDiffCBPHP[] ) { | Reference | +|-----------------------------------------------|------------------| +| iCBPHP = iDiffCBPHP[i] | | +| if (CBPHPModelHP.CBPHPState[1] == 0) { | | +| if (IsMBLeftEdgeofTileFlag) | | +| if (IsMBTopEdgeofTileFlag) | | +| iCBPHP ^= 1 | | +| else | | +| iCBPHP ^= ((MBCBPHP[MBx][MBy-1][i] >> 2) & 1) | | +| else | | +| iCBPHP ^= ((MBCBPHP[MBx-1][MBy][i] >> 1) & 1) | | +| iCBPHP ^= (0x02 & (iCBPHP << 1)) | | +| iCBPHP ^= ((iCBPHP & 0x3) << 2) | | +| } else if (CBPHPModelHP.CBPHPState[1] == 2) | | +| iCBPHP ^= 0x0F | | +| iNOrig = Numones(iCBPHP) * 4 | | +| UpdateCBPHPModel(1, iNOrig) | 8.10.2 | +| return iCBPHP | | +| } | | + +### 8.7.18 Macroblock highpass + +#### 8.7.18.1 General + +The presence of non-zero HP coefficients in the j-th block in the colour component is specified by $((\text{MBCBPHP}[\text{MBx}][\text{MBy}][i] \gg j) \& 1)$ , where the blocks are scanned in the hierarchical raster scan order specified in 8.7.17.1. If there are non-zero coefficients in a block, these coefficients are parsed by invoking the process `DECODE_BLOCK_ADAPTIVE()`, specified in 8.7.18.4, which in turn invokes the process `DECODE_BLOCK()` specified in 8.7.18.5 for parsing the coefficients and invokes the process `AdaptiveHPScan()` to determine the inverse scanning order of the coefficients. + +#### 8.7.18.2 MB\_HP() + +The MB\_HP() syntax structure is specified in Table 69. + +**Table 69 – MB\_HP ( ) syntax structure** + +| MB_HP ( ) { | Descriptor | Reference | +|----------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------|------------------| +| /* IsCurrPlaneAlphaFlag is equal to TRUE for parsing alpha image plane, and
IsCurrPlaneAlphaFlag is equal to FALSE for parsing primary image plane */ | | | +| iBand = 2 | | | +| iHierScanOrder[ ] = {0, 1, 4, 5, 2, 3, 6, 7, 8, 9, 12, 13, 10, 11, 14, 15} | | | +| bInitializeContext = (IsMBLeftEdgeOfTileFlag && IsMBTopEdgeOfTileFlag) | | | +| if (bInitializeContext) { | | | +| InitializeHPVLC ( ) | | 8.8.3.3 | +| InitializeAdaptiveScanHP ( ) | | 8.11.3 | +| InitializeModelMB(ModelHP, iBand) | | 8.12.1 | +| } | | | +| bResetTotals = (((MBx - LeftMBIndexOfTile[TileIndexx]) % 16) == 0) | | | +| if (bResetTotals) | | | +| ResetTotalsAdaptiveScanHP ( ) | | 8.11.5 | +| iLapMean[ ] = {0, 0} | | | +| for (i = 0; i < NumComponents; i++) { | | | +| bChroma = (i > 0) | | | +| iNBlocks = 4 | | | +| if (bChroma && INTERNAL_CLR_FMT == YUV420) | | | +| iNBlocks = 1 | | | +| else if (bChroma && INTERNAL_CLR_FMT == YUV422) | | | +| iNBlocks = 2 | | | +| iCBPHP = MBCBPHP[MBx][MBy][i] | | | +| for (iBlock = 0; iBlock < iNBlocks * 4; iBlock++) { | | | +| iBlockMap = iBlock | | | +| if (iNBlocks == 4) | | | +| iBlockMap = iHierScanOrder[iBlock] | | | +| for (k = 0; k < 16; k++) | | | +| HPInputVLC[i][iBlock][k] = 0 | | | +| iNumNonZero = | | | +| DECODE_BLOCK_ADAPTIVE(iCBPHP & 1, bChroma, i, iBlockMap) | | 8.7.18.4 | +| iLapMean[bChroma] += iNumNonZero | | | +| iCBPHP >>= 1 | | | +| } | | | +| } | | | +| ModelBitsMBHP[MBx][MBy][0] = ModelHP.MBits[0] | | | +| ModelBitsMBHP[MBx][MBy][1] = ModelHP.MBits[1] | | | +| UpdateModelMB(iLapMean[ ], ModelHP, iBand) | | 8.12.2 | +| bResetContext = (MBx == (LeftMBIndexOfTile[TileIndexx] + 1) - 1)
(MBx - LeftMBIndexOfTile[TileIndexx]) % 16 == 0) | | | +| if (bResetContext) | | | +| AdaptHP ( ) | | 8.8.4.3 | +| } | | | + +### 8.7.18.3 MB\_HP\_FLEX ( ) + +The MB\_HP\_FLEX ( ) syntax structure is specified in Table 70. + +**Table 70 – MB\_HP\_FLEX() syntax structure** + +| MB_HP_FLEX() { | Descriptor | Reference | +|----------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------|------------------| +| /* IsCurrPlaneAlphaFlag is equal to TRUE for parsing alpha image plane, and
IsCurrPlaneAlphaFlag is equal to FALSE for parsing primary image plane */ | | | +| iBand = 2 | | | +| iHierScanOrder[ ] = {0, 1, 4, 5, 2, 3, 6, 7, 8, 9, 12, 13, 10, 11, 14, 15} | | | +| bInitializeContext = (IsMBLeftEdgeOfTileFlag && IsMBTopEdgeOfTileFlag) | | | +| if (bInitializeContext) { | | | +| InitializeHPVLC( ) | | 8.8.3.3 | +| InitializeAdaptiveScanHP( ) | | 8.11.3 | +| InitializeModelMB(ModelHP, iBand) | | 8.12.1 | +| } | | | +| bResetTotals = (((MBx - LeftMBIndexOfTile[TileIndexx]) % 16) == 0) | | | +| if (bResetTotals) | | | +| ResetTotalsAdaptiveScanHP( ) | | 8.11.5 | +| iLapMean[ ] = {0, 0} | | | +| for (i = 0; i < NumComponents; i++) { | | | +| iIndex = 0 | | | +| bChroma = i > 0 | | | +| if (i > 0) | | | +| iIndex = 1 | | | +| iModelBits = ModelHP.MBits[iIndex] | | | +| iNBlocks = 4 | | | +| if (bChroma && INTERNAL_CLR_FMT == YUV420) | | | +| iNBlocks = 1 | | | +| else if (bChroma && INTERNAL_CLR_FMT == YUV422) | | | +| iNBlocks = 2 | | | +| iCBPHP = MBCBPHP[MBx][MBy][i] | | | +| for (iBlock = 0; iBlock < iNBlocks*4; iBlock++) { | | | +| iBlockMap = iBlock | | | +| if (iNBlocks == 4) | | | +| iBlockMap = iHierScanOrder[iBlock] | | | +| for (k = 0; k < 16; k++) | | | +| HPInputVLC[i][iBlock][k] = 0 | | | +| iNumNonZero = | | 8.7.18.4 | +| DECODE_BLOCK_ADAPTIVE(iCBPHP & 1, bChroma, i, iBlockMap) | | | +| if (BANDS_PRESENT != NOFLEXBITS) | | | +| BLOCK_FLEXBITS(i, iBlockMap, iModelBits, TRIM_FLEXBITS) | | 8.7.19.2 | +| iLapMean[bChroma] += iNumNonZero | | | +| iCBPHP >>= 1 | | | +| } | | | +| } | | | +| ModelBitsMBHP[MBx][MBy][0] = ModelHP.MBits[0] | | | +| ModelBitsMBHP[MBx][MBy][1] = ModelHP.MBits[1] | | | +| UpdateModelMB(iLapMean[ ], ModelHP, iBand) | | 8.12.2 | +| bResetContext = (MBx == (LeftMBIndexOfTile[TileIndexx + 1] - 1)
(MBx - LeftMBIndexOfTile[TileIndexx]) % 16 == 0) | | | +| if (bResetContext) | | | +| AdaptHP( ) | | 8.8.4.3 | +| } | | | + +#### 8.7.18.4 DECODE\_BLOCK\_ADAPTIVE() + +The DECODE\_BLOCK\_ADAPTIVE( ) syntax structure is specified in Table 71. + +**Table 71 – DECODE\_BLOCK\_ADAPTIVE() syntax structure** + +| DECODE_BLOCK_ADAPTIVE(bNoSkip, bChroma, iComponent, iBlock) { | Descriptor | Reference | +|----------------------------------------------------------------------|-------------------|------------------| +| iBand = 2 /* 0 = DC 1 = LP, 2 = HP */ | | | +| for (i = 0; i < 32; i++) | | | +| iLocalCoeff[i] = 0 | | | +| iLocation = 1 | | | +| iNumNonZero = 0 | | | +| if (bNoSkip) { | | | +| iNumNonZero = | | 8.7.18.5 | +| DECODE_BLOCK(bChroma, iLocalCoeff[ ], iBand, iLocation) | | | +| k = iLocation | | | +| for (kk = 0; kk < iNumNonZero; kk++) { | | | +| k += iLocalCoeff[kk * 2] | | | +| AdaptiveHPScan(iComponent, iBlock, k, iLocalCoeff[kk * 2 + 1]) | | 8.11.7 | +| k++ | | | +| } | | | +| } | | | +| return iNumNonZero | | | +| } | | | + +### 8.7.18.5 DECODE\_BLOCK() + +The DECODE\_BLOCK() syntax structure is specified in Table 72. + +**Table 72 – DECODE\_BLOCK() syntax structure** + +| DECODE_BLOCK(bChroma, iCoeff[ ], iBand, iLocation) { | Descriptor | Reference | +|-------------------------------------------------------------|-------------------|------------------| +| iNumNZ = 1 | | | +| iFirstIndex = DECODE_FIRST_INDEX(bChroma, iBand) | | 8.7.18.8 | +| SIGN_FLAG | u(1) | 8.7.14.4 | +| iSR = (iFirstIndex & 1) | | | +| iSRn = (iFirstIndex >> 2) | | | +| iContext = (iSR & iSRn) | | | +| if (iFirstIndex & 2) | | | +| iCoeff[1] = DECODE_ABS_LEVEL(iBand, bChroma, iContext) | | 8.7.13 | +| else | | | +| iCoeff[1] = 1 | | | +| if (SIGN_FLAG) | | | +| iCoeff[1] = -iCoeff[1] | | | +| iCoeff[0] = 0 | | | +| if (iSR == 0) | | | +| iCoeff[0] = DECODE_RUN(15 - iLocation) | | 8.7.18.6 | +| iLocation += iCoeff[0] + 1 | | | +| while (iSRn != 0) { | | | +| iSR = (iSRn & 1) | | | +| iCoeff[iNumNZ * 2] = 0 | | | +| if (iSR == 0) | | | +| iCoeff[iNumNZ * 2] = DECODE_RUN(15 - iLocation) | | 8.7.18.6 | +| iLocation += (iCoeff[iNumNZ * 2] + 1) | | | +| iIndex = DECODE_INDEX(iLocation, bChroma, iBand, iContext) | | 8.7.18.7 | +| iSRn = (iIndex >> 1) | | | +| iContext &= iSRn | | | +| SIGN_FLAG | u(1) | 8.7.14.4 | +| if (iIndex & 1) | | | +| iCoeff[(iNumNZ * 2) + 1] = | | 8.7.13 | +| DECODE_ABS_LEVEL(iBand, bChroma, iContext) | | | +| else | | | +| iCoeff[(iNumNZ * 2) + 1] = 1 | | | +| if (SIGN_FLAG) | | | +| iCoeff[(iNumNZ * 2) + 1] = -iCoeff[(iNumNZ * 2) + 1] | | | +| iNumNZ++ | | | +| } | | | +| return iNumNZ | | | +| } | | | + +### 8.7.18.6 DECODE\_RUN() + +The DECODE\_RUN() syntax structure is specified in Table 73. + +Table 73 – DECODE\_RUN() syntax structure + +| DECODE_RUN(iMaxRun) { | Descriptor | Reference | +|--------------------------------------------------------------------|------------|------------| +| iRemap[ ] = {1, 2, 3, 5, 7, 1, 2, 3, 5, 7, 1, 2, 3, 4, 5} | | | +| iRunBin[ ] = {-1, -1, -1, -1, 2, 2, 2, 1, 1, 1, 1, 0, 0, 0, 0} | | | +| iRunFixedLength[ ] = {0, 0, 1, 1, 3, 0, 0, 1, 1, 2, 0, 0, 0, 0, 1} | | | +| if (iMaxRun < 5) { | | | +| iRun = 1; | | | +| if (iMaxRun != 1) { | | | +| RUN_VALUE | e(v) | 8.7.18.9.1 | +| iRun = RUN_VALUE | | | +| } | | | +| } else { | | | +| RUN_INDEX | e(v) | 8.7.18.9.2 | +| iIndex = RUN_INDEX + 5* iRunBin[iMaxRun] | | | +| iFixed = iRunFixedLength[iIndex] | | | +| iRun = iRemap[iIndex] | | | +| if (iFixed) { | | | +| RUN_REF | u(iFixed) | 8.7.18.9.3 | +| iRun += RUN_REF | | | +| } | | | +| } | | | +| return iRun | | | +| } | | | + +### 8.7.18.7 DECODE\_INDEX() + +The DECODE\_INDEX() syntax structure is specified in Table 74. + +Table 74 – DECODE\_INDEX() syntax structure + +| DECODE_INDEX(iLocation, bChroma, iBand, iContext) { | Descriptor | Reference | +|-----------------------------------------------------------------|------------|------------| +| /* sAdaptVLC is local instance of AdaptiveVLC data structure */ | | | +| if (iBand == 1) /* LP */ | | | +| if (bChroma) | | | +| if (iContext) | | | +| sAdaptVLC = DecIndLPChr1 | | | +| else | | | +| sAdaptVLC = DecIndLPChr0 | | | +| else /* Luma */ | | | +| if (iContext) | | | +| sAdaptVLC = DecIndLPum1 | | | +| else | | | +| sAdaptVLC = DecIndLPum0 | | | +| else if (iBand == 2) /* HP */ | | | +| if (bChroma) | | | +| if (iContext) | | | +| sAdaptVLC = DecIndHPChr1 | | | +| else | | | +| sAdaptVLC = DecIndHPChr0 | | | +| else /* Luma */ | | | +| if (iContext) | | | +| sAdaptVLC = DecIndHPLum1 | | | +| else | | | +| sAdaptVLC = DecIndHPLum0 | | | +| if (iLocation < 15) { | | | +| INDEX_A /* variable-length parse with sAdaptVLC */ | ae(v) | 8.7.18.9.4 | +| /* update the discriminants for sAdaptVLC */ | | | +| sAdaptVLC.DiscrimVal1 += | | Table 88 | +| Index1Delta[sAdaptVLC.DeltaTableIndex][INDEX_A] | | | + +| DECODE INDEX(iLocation, bChroma, iBand, iContext) { | Descriptor | Reference | +|------------------------------------------------------------------------------|------------|------------| +| sAdaptVLC.DiscrimVal2 +=
Index1Delta[sAdaptVLC.Delta2TableIndex][INDEX_A] | | Table 88 | +| iIndex = INDEX_A | | | +| } else if (iLocation == 15) { | | | +| INDEX_B | e(v) | 8.7.18.9.5 | +| iIndex = INDEX_B | | | +| } else { | | | +| INDEX_C_FLAG | u(1) | 8.7.18.9.6 | +| iIndex = INDEX_C_FLAG | | | +| } | | | +| return iIndex | | | +| } | | | + +### 8.7.18.8 DECODE\_FIRST\_INDEX() + +The DECODE\_FIRST\_INDEX() syntax structure is specified in Table 75. + +**Table 75 – DECODE\_FIRST\_INDEX() syntax structure** + +| DECODE FIRST_INDEX(bChroma, iBand) { | Descriptor | Reference | +|--------------------------------------------------------------------------------------|------------|------------| +| /* sAdaptVLC is local instance of AdaptiveVLC data structure */ | | | +| if (iBand == 1) /* LP */ | | | +| if (bChroma) | | | +| sAdaptVLC = DecFirstIndLPChr | | | +| else /* Luma */ | | | +| sAdaptVLC = DecFirstIndLP Lum | | | +| else if (iBand == 2) /* HP */ | | | +| if (bChroma) | | | +| sAdaptVLC = DecFirstIndHPChr | | | +| else /* Luma */ | | | +| sAdaptVLC = DecFirstIndHPLum | | | +| FIRST_INDEX /* Decode with sAdaptVLC */ | ae(v) | 8.7.18.9.7 | +| /* update Discriminants for sAdaptVLC */ | | | +| sAdaptVLC.DiscrimVal1 +=
FirstIndexDelta[sAdaptVLC.DeltaTableIndex][FIRST_INDEX] | | Table 87 | +| sAdaptVLC.DiscrimVal2 +=
FirstIndexDelta[sAdaptVLC.Delta2TableIndex][FIRST_INDEX] | | Table 87 | +| return FIRST_INDEX | | | +| } | | | + +### 8.7.18.9 Block-level semantics + +#### 8.7.18.9.1 RUN\_VALUE + +RUN\_VALUE is a variable-length syntax element that is present when iMaxRun is greater than 1 and iMaxRun is less than 5. It specifies the value of run. If iMaxRun is equal to 2, the parsing of RUN\_VALUE is specified in Table 76. Otherwise, if iMaxRun is equal to 3, the parsing of RUN\_VALUE is specified in Table 77. Otherwise, (if iMaxRun is equal to 4), the parsing of RUN\_VALUE is specified in Table 78. + +**Table 76 – Code table of RUN\_VALUE if iMaxRun == 2** + +| Code | Value | +|------|-------| +| 1 | 1 | +| 0 | 2 | + +**Table 77 – Code table of RUN\_VALUE if iMaxRun == 3** + +| Code | Value | +|------|-------| +| 1 | 1 | +| 01 | 2 | +| 00 | 3 | + +**Table 78 – Code table of RUN\_VALUE if iMaxRun == 4** + +| Code | Value | +|------|-------| +| 1 | 1 | +| 01 | 2 | +| 001 | 3 | +| 000 | 4 | + +**8.7.18.9.2 RUN\_INDEX** + +RUN\_INDEX is a variable-length syntax element that is present when iMaxRun is greater than or equal to 5. It specifies the value of iRun in 8.7.18.6. The parsing of RUN\_INDEX is specified in Table 79. + +**Table 79 – Code table of RUN\_INDEX** + +| Code | Value | +|------|-------| +| 1 | 0 | +| 01 | 1 | +| 001 | 2 | +| 0000 | 3 | +| 0001 | 4 | + +**8.7.18.9.3 RUN\_REF** + +RUN\_REF is a fixed-length syntax element that specifies the value of iRun in 8.7.18.6. The presence and size of the RUN\_REF syntax element is indicated by iFixed, as specified in 8.7.18.6. + +**8.7.18.9.4 INDEX\_A** + +INDEX\_A is a variable-length syntax element that is present when iLocation is less than 15. It has a value in the range of 0 to 5, inclusive. The coding of this symbol uses one of four tables. The choice of table is adaptively determined as specified in 8.8.4. The VLC tables are specified in Table 80. + +**Table 80 – Code table for INDEX\_A** + +| Code 0 | Code 1 | Code 2 | Code 3 | Value | +|--------|--------|--------|--------|-------| +| 1 | 01 | 0000 | 0 0000 | 0 | +| 0 0000 | 0000 | 0001 | 0 0001 | 1 | +| 001 | 10 | 01 | 01 | 2 | +| 0 0001 | 0001 | 10 | 1 | 3 | +| 01 | 11 | 11 | 0001 | 4 | +| 0001 | 001 | 001 | 001 | 5 | + +INDEX\_A jointly codes the following two events. + +- The binary event of whether the magnitude of the next non-zero coefficient is equal to 1 or greater than 1 as follows. + - If (INDEX\_A & 1) is equal to 0, this magnitude is equal to 1. + - Otherwise, this magnitude is greater than 1. +- The ternary of event whether this coefficient is the last coefficient in the block, and if there are more non-zero coefficients, whether the run before the next non-zero coefficient is zero or non-zero, as follows. + +- If $(\text{INDEX\_A} \gg 1)$ is equal to 0, this coefficient is the last coefficient in the block. +- Otherwise, if $(\text{INDEX\_A} \gg 1)$ is equal to 1, the run before the next non-zero coefficient is zero. +- Otherwise (i.e. when $(\text{INDEX\_A} \gg 1)$ is equal to 2), the run before the next non-zero coefficient is non-zero. + +NOTE – Thus INDEX\_A has an alphabet size of $2^3=6$ . + +### 8.7.18.9.5 INDEX\_B + +INDEX\_B is a variable-length syntax element that is present when iLocation is equal to 15. It has a value in the range of 0 to 3, inclusive. The VLC table is specified in Table 81. + +**Table 81 – Code table for INDEX\_B** + +| Code | Value | +|------|-------| +| 0 | 0 | +| 10 | 2 | +| 110 | 1 | +| 111 | 3 | + +INDEX\_B jointly codes the following two events. + +- The binary event of whether the magnitude of the next non-zero coefficient is equal to 1 or greater than 1 as follows. + - If $(\text{INDEX\_B} \& 1)$ is equal to 0, this magnitude is equal to 1. + - Otherwise, this magnitude is greater than 1. +- The binary event of whether this coefficient is the last coefficient in the block or if there are more non-zero coefficients, as follows. + - If $(\text{INDEX\_B} \gg 1)$ is equal to 0, this coefficient is the last coefficient in the block. + - Otherwise, the run before the next non-zero coefficient is zero. + +NOTE – Thus INDEX\_B has an alphabet size of $2^2=4$ . + +### 8.7.18.9.6 INDEX\_C\_FLAG + +INDEX\_C\_FLAG is a 1-bit syntax element that is present when iLocation is equal to 16. It specifies the presence of subsequent run/level symbols. + +### 8.7.18.9.7 FIRST\_INDEX + +FIRST\_INDEX is a variable-length syntax element that has a value in the range of 0 to 11, inclusive. The coding of this syntax element uses one of five tables. The choice of table is adaptively determined as specified in 8.8.4. The VLC tables are specified in Table 82. + +**Table 82 – Code table for FIRST\_INDEX** + +| Code 0 | Code 1 | Code 2 | Code 3 | Code 4 | Value | +|----------|---------|----------|----------|-----------|-------| +| 0000 1 | 0010 | 11 | 001 | 010 | 0 | +| 0000 01 | 0001 0 | 001 | 11 | 1 | 1 | +| 0000 000 | 0000 00 | 0000 000 | 0000 000 | 0000 001 | 2 | +| 0000 001 | 0000 01 | 0000 001 | 0000 1 | 0001 | 3 | +| 0010 0 | 0011 | 0000 1 | 0001 0 | 0000 010 | 4 | +| 010 | 010 | 010 | 010 | 011 | 5 | +| 0010 1 | 0001 1 | 0000 010 | 0000 001 | 0000 0000 | 6 | +| 1 | 11 | 011 | 011 | 0010 | 7 | +| 0011 0 | 011 | 100 | 0001 1 | 0000 011 | 8 | +| 0001 | 100 | 101 | 100 | 0011 | 9 | +| 0011 1 | 0000 1 | 0000 011 | 0000 01 | 0000 0001 | 10 | +| 011 | 101 | 0001 | 101 | 0000 1 | 11 | + +FIRST\_INDEX jointly codes the following three events. + +- The binary event of whether the run before the first non-zero coefficient is non-zero or zero as follows. + +- If (FIRST\_INDEX & 1) is equal to 0, this run is non-zero. + - Otherwise this run is zero. + - The binary event of whether the magnitude of the first non-zero coefficient is equal to 1 or greater than 1 as follows. + - If (FIRST\_INDEX & 2) is equal to 0, this magnitude is equal to 1. + - Otherwise, this magnitude is greater than 1. + - The ternary event of whether the first coefficient is the last coefficient in the block, and if there are more non-zero coefficients whether the run before the next non-zero coefficient is zero or non-zero, as follows. + - If (FIRST\_INDEX >> 2) is equal to 0, the first coefficient is the last coefficient in the block. + - Otherwise, if (FIRST\_INDEX >> 2) is equal to 1, the run before the next non-zero coefficient is zero. + - Otherwise ((FIRST\_INDEX >> 2) is equal to 2), the run before the next non-zero coefficient is non-zero. +- NOTE – Thus FIRST\_INDEX has an alphabet size of $2^3 \times 3 = 12$ . + +## 8.7.19 Macroblock FLEXBITS + +### 8.7.19.1 MB\_FLEXBITS() + +The MB\_FLEXBITS() syntax structure is specified in Table 83. + +**Table 83 – MB\_FLEXBITS() syntax structure** + +| MB_FLEXBITS() { | Descriptor | Reference | +|--------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------|------------------| +| /* IsCurrPlaneAlphaFlag is equal to TRUE for parsing alpha image plane, and IsCurrPlaneAlphaFlag is equal to FALSE for parsing primary image plane */ | | | +| iHierScanOrder[ ] = {0, 1, 4, 5, 2, 3, 6, 7, 8, 9, 12, 13, 10, 11, 14, 15} | | | +| for (i = 0; i < NumComponents; i++) { | | | +| iIndex = 0 | | | +| if (i > 0) | | | +| iIndex = 1 | | | +| iModelBits = ModelBitsMBHP[MBx][MBy][iIndex] | | | +| iNBlocks = 4 | | | +| if ((iIndex == 1) && (INTERNAL_CLR_FMT == YUV420)) | | | +| iNBlocks = 1 | | | +| else if (iIndex && (INTERNAL_CLR_FMT == YUV422)) | | | +| iNBlocks = 2 | | | +| for (iBlock = 0; iBlock < iNBlocks * 4; iBlock++) { | | | +| iBlockMap = iBlock | | | +| if (iNBlocks == 4) | | | +| iBlockMap = iHierScanOrder[iBlock] | | | +| BLOCK_FLEXBITS(i, iBlockMap, iModelBits, TRIM_FLEXBITS) | | 8.7.19.2 | +| } | | | +| } | | | +| } | | | + +NOTE – Informative remarks related to this subclause are provided in subclause D.9. + +### 8.7.19.2 BLOCK\_FLEXBITS( ) + +The BLOCK\_FLEXBITS( ) syntax structure is specified in Table 84. + +**Table 84 – BLOCK\_FLEXBITS( ) syntax structure** + +| BLOCK_FLEXBITS(iComponent, iBlock, iModelBits, iTrimFlexBits) { | Descriptor | Reference | +|---------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------|------------------| +| iTranspose444[ ] = {0, 4, 8, 12, 1, 5, 9, 13, 2, 6, 10, 14, 3, 7, 11, 15} | | | +| iFlexBitsLeft = iModelBits – iTrimFlexBits | | | +| if (iFlexBitsLeft < 0) | | | +| iFlexBitsLeft = 0 | | | +| if (iFlexBitsLeft) | | | +| for (n = 1; n < 16; n++) | | | +| HPInputFlex[iComponent][iBlock][iTranspose444[n]] =
DECODE_FLEX(HPInputVLC[iComponent][iBlock][iTranspose444[n]],
iFlexBitsLeft) << iTrimFlexBits | | 8.7.19.3 | +| } | | | + +### 8.7.19.3 DECODE\_FLEX( ) + +The DECODE\_FLEX( ) syntax structure is specified in Table 85. + +**Table 85 – DECODE\_FLEX( ) syntax structure** + +| DECODE_FLEX(iVLCCoeff, iFlexBitsLeft) { | Descriptor | Reference | +|------------------------------------------------|-------------------|------------------| +| FLEX_REF | u(iFlexBitsLeft) | 8.7.19.4.1 | +| if (iVLCCoeff > 0) | | | +| iFlexCoeff = FLEX_REF | | | +| else if (iVLCCoeff < 0) | | | +| iFlexCoeff = –FLEX_REF | | | +| else { | | | +| iFlexCoeff = FLEX_REF | | | +| if (iFlexCoeff) { | | | +| SIGN_FLAG | u(1) | 8.7.14.4 | +| if (SIGN_FLAG) | | | +| iFlexCoeff = –iFlexCoeff | | | +| } | | | +| } | | | +| return iFlexCoeff | | | +| } | | | + +### 8.7.19.4 FLEXBITS semantics + +#### 8.7.19.4.1 FLEX\_REF + +FLEX\_REF is a syntax element that specifies the flexbits part of the HP coefficient. The size of this syntax element is specified by iFlexBits. + +## 8.8 Adaptive VLC code table selection + +### 8.8.1 General + +Adaptive VLC table selection is a process by which the entropy coding method adapts to image statistics and thus provides better compression. First, a few representative VLC tables are predefined. These tables are designed to be suitable for a wide range of statistics. During the entropy coding process, the most appropriate code table is selected based on the history of recently coded symbols. The VLC tables and the information required for adaptation are precomputed as follows. + +Let the set of VLC tables be: **vT1**, **vT2**, ..., **vTn** where the ordering of the tables is predefined based on their relative similarity. That is **vT1** and **vT2** exhibit greater similarity to each other than **vT1** and **vT3** do to each other. The measure of similarity between tables can be qualified by using relative entropy. Let table **vTi** be a VLC table used for entropy coding of symbol **iX**, and let **vTj** and **vTk** be the two nearest tables (in terms of similarity). For each value of symbol **iX**, + +a metric $\text{deltaDisc}$ estimating the relative advantage of coding this value using table $\mathbf{vTj}$ or table $\mathbf{vTk}$ instead of table $\mathbf{vTi}$ is precomputed and stored in tables $\mathbf{vTi.DeltaTableIndex}$ and $\mathbf{vTi.Delta2TableIndex}$ . This $\text{deltaDisc}$ is positive if this symbol is more efficiently coded by the new table instead of the current table. This $\text{deltaDisc}$ is negative if this symbol is less efficiently coded by the new table instead of the current table. For example, if a given value of the symbol requires 3 bits in the new table, while it requires 5 bits in the current table, this value is more efficiently coded in the new table and the corresponding $\text{deltaDisc}$ is $(5 - 3 = 2)$ . + +The table selection proceeds as follows: After entropy coding a symbol, the adaptation process computes the relative advantage of the two nearest tables for coding this symbol. The weights obtained from the tables $\mathbf{vTi.DeltaTableIndex}$ and $\mathbf{vTi.Delta2TableIndex}$ are added to two discriminants, $\mathbf{vTi.DiscrimVal1}$ and $\mathbf{vTi.DiscrimVal2}$ , that are used for accumulating the statistics regarding code table transition. The $\text{AdaptVLCTable1}()$ (8.8.4.4) and the $\text{AdaptVLCTable2}()$ (8.8.4.5) pseudocode functions specify how these discriminants are compared to predefined threshold, and decide whether to continue to use the current table or to transition to one of the nearest tables. If there is a transition, the discriminants are reset to zero. + +As the discriminants are computed based on previously coded symbols both at the encoder and at the decoder, there is no need for additional side information to signal the selected VLC. For coding some symbols, there are only two code tables, and there is only one possible transition. The adaptation complexity is further reduced in these cases as there is only the $\text{DeltaTableIndex}$ and only one discriminant is required. + +NOTE – Informative remarks related to this subclause are provided in D.9. + +### 8.8.2 Adaptive VLC $\text{deltaDisc}$ tables + +When a syntax element is parsed using a VLC having a code table that can be adaptively selected, the associated AdaptiveVLC data structure's member variables $\text{DiscrimVal1}$ and $\text{DiscrimVal2}$ are modified by adding an amount $\text{deltaDisc}$ . The specific value of this $\text{deltaDisc}$ is dependent on the syntax element being parsed, the VLC code table currently being used to parse this syntax element, the current value of this syntax element and (when there are two discriminants) which discriminant is being modified. + +Based on these factors, the appropriate values of $\text{deltaDisc}$ are specified by collecting them in tables. For each syntax element, a distinct collection of tables of $\text{deltaDisc}$ values is defined; from here on these tables are called $\text{deltaDisc}$ tables. A syntax element which is parsed using adaptive VLC tables will have $N$ code tables for each syntax element, for some positive integer $N > 1$ . If there are $N$ code tables for a syntax element, there are $N - 1$ $\text{deltaDisc}$ tables (one $\text{deltaDisc}$ table for switching between code tables $i$ and $i + 1$ , for $i$ ranging between 0 and $N - 2$ inclusive). The AdaptiveVLC data structure associates to $\text{DiscrimVal1}$ the associated variable $\text{DeltaTableIndex}$ ( $\text{Delta2TableIndex}$ for $\text{DiscrimVal2}$ ); $\text{DeltaTableIndex}$ defines which of the $N - 1$ $\text{deltaDisc}$ tables is in use for the current macroblock. + +The syntax element itself takes values between 0 and $M - 1$ , where $M$ represents the number of entries in this syntax element's code table. For each of these values, there is defined an associated $\text{deltaDisc}$ value. In this way, when the syntax element takes the value $i\text{Val}$ , the modification of an AdaptiveVLC data structures discriminants is specified as follows (here, $\mathbf{sAdaptVLC}$ is a local variable used in place of particular AdaptiveVLC data structure instance). + +- $\mathbf{sAdaptVLC.DiscrimVal1}$ is incremented by $\text{deltaDisc}[\mathbf{sAdaptVLC.DeltaTableIndex}][i\text{Val}]$ . +- $\mathbf{sAdaptVLC.DiscrimVal2}$ is incremented by $\text{deltaDisc}[\mathbf{sAdaptVLC.Delta2TableIndex}][i\text{Val}]$ . + +Table 86, Table 87, Table 88, Table 89, Table 90 and Table 91 specify the set of $\text{deltaDisc}$ code tables for adaptive VLC syntax elements. + +For the syntax element $\text{ABS\_LEVEL\_INDEX}$ (8.7.14.5), there is one $\text{deltaDisc}$ table for switching between Code tables 0 and 1, as specified in Table 86. + +**Table 86 – Constant table $\text{AbslevelIndexDelta}[m][n]$** + +| Index value
$n$ | Value for
$m = 0$ | +|--------------------|----------------------| +| 0 | 1 | +| 1 | 0 | +| 2 | -1 | +| 3 | -1 | +| 4 | -1 | +| 5 | -1 | +| 6 | -1 | + +For the syntax element FIRST\_INDEX (8.7.18.9.7), there are four Delta tables, with the table associating a different deltaDisc value for each DeltaTableIndex and each value of FIRST\_INDEX; the deltaDisc values are specified in Table 87. + +**Table 87 – Constant table FirstIndexDelta[m][n]** + +| Index value
n | Value for
m = 0 | Value for
m = 1 | Value for
m = 2 | Value for
m = 3 | +|------------------|--------------------|--------------------|--------------------|--------------------| +| 0 | 1 | 2 | -1 | 0 | +| 1 | 1 | 2 | 1 | 1 | +| 2 | 1 | -1 | 0 | 0 | +| 3 | 1 | -1 | 2 | 1 | +| 4 | 1 | -1 | 0 | -2 | +| 5 | 0 | 0 | 0 | 0 | +| 6 | 0 | -2 | 0 | -1 | +| 7 | -1 | -1 | 0 | -1 | +| 8 | 2 | 0 | -2 | -2 | +| 9 | 1 | 0 | 0 | -1 | +| 10 | 0 | -2 | 1 | -2 | +| 11 | 0 | -1 | 1 | -2 | + +For the syntax element INDEX\_A (8.7.18.9.4), there are three Delta tables, as specified in Table 88. + +**Table 88 – Constant table Index1Delta[m][n]** + +| Index value
n | Value for
m = 0 | Value for
m = 1 | Value for
m = 2 | +|------------------|--------------------|--------------------|--------------------| +| 0 | -1 | -2 | -1 | +| 1 | 1 | 0 | -1 | +| 2 | 1 | 0 | 0 | +| 3 | 1 | 2 | 1 | +| 4 | 0 | 0 | -2 | +| 5 | 1 | 0 | 0 | + +For the syntax element NUM\_CBPHP (8.7.17.4.1), there is one deltaDisc table for switching between Code tables 0 and 1 as specified in Table 89. + +**Table 89 – Constant table NumCBPHPDelta[m][n]** + +| Index value
n | Value for
m = 0 | +|------------------|--------------------| +| 0 | 0 | +| 1 | -1 | +| 2 | 0 | +| 3 | 1 | +| 4 | 1 | + +For the syntax element NUM\_BLKCBPHP (8.7.17.4.2), there is one deltaDisc table for switching between Code tables 0 and 1. In the case where the INTERNAL\_CLR\_FMT is YONLY, NCOMPONENT or YUVK, the code tables have five symbols and the deltaDisc table is specified in Table 90. + +**Table 90 – Constant table NumBlkCBPHPDelta[m][n] +when INTERNAL\_CLR\_FMT is +YONLY, NCOMPONENT or YUVK** + +| Index value
n | Value for
m = 0 | +|------------------|--------------------| +| 0 | 0 | +| 1 | −1 | +| 2 | 0 | +| 3 | 1 | +| 4 | 1 | + +For all other values of INTERNAL\_CLR\_FMT, the code table for NUM\_BLKCBPHP has nine symbols, and the deltaDisc table is specified in Table 91. + +**Table 91 – Constant table NumBlkCBPHPDelta +for INTERNAL\_CLR\_FMT other than +YONLY, NCOMPONENT, and YUVK** + +| Index value
n | Value for
m = 0 | +|------------------|--------------------| +| 0 | 2 | +| 1 | 2 | +| 2 | 1 | +| 3 | 1 | +| 4 | −1 | +| 5 | −2 | +| 6 | −2 | +| 7 | −2 | +| 8 | −3 | + +### 8.8.3 Initialization + +The relevant adaptive VLC data structures that are associated with each of the three bands DC, LP and HP are initialized by the functions InitializeDCVLC(), InitializeLPVLC() and InitializeHPVLC(). These functions are specified in 8.8.3.1, 8.8.3.2, and 8.8.3.3, respectively. The adaptive VLC structure associated with CBPHP is initialized by the function InitializeCBPHPVLC() that is specified in 8.8.3.4. + +These functions in turn make use of the functions InitializeVLCTable1() and InitializeVLCTable2() which are specified in 8.8.3.5 and 8.8.3.6, respectively. + +NOTE – InitializeVLCTable1() is used for initializing VLC code tables when there are exactly two code tables. If there are more than two code table tables, InitializeVLCTable2() is used. + +### 8.8.3.1 InitializeDCVLC() + +The pseudocode for the function InitializeDCVLC() is specified in Table 92. + +**Table 92 – Pseudocode for the function InitializeDCVLC()** + +| InitializeDCVLC() { | Reference | +|-----------------------------------------------------------------|------------------| +| AbsLevelIndDCLum = InitializeVLCTable1(AbsLevelIndDCLum) | 8.8.3.5 | +| AbsLevelIndDCChr = InitializeVLCTable1(AbsLevelIndDCChr) | 8.8.3.5 | +| } | | + +### 8.8.3.2 InitializeLPVLC() + +The pseudocode for the function InitializeLPVLC() is specified in Table 93. + +**Table 93 – Pseudocode for the function InitializeLPVLC()** + +| InitializeLPVLC() { | Reference | +|-----------------------------------------------------------------|------------------| +| DecFirstIndLPLum = InitializeVLCTable2(DecFirstIndLPLum) | 8.8.3.6 | +| DecIndLPLum0 = InitializeVLCTable2(DecIndLPLum0) | 8.8.3.6 | +| DecIndLPLum1 = InitializeVLCTable2(DecIndLPLum1) | 8.8.3.6 | +| DecFirstIndLPChr = InitializeVLCTable2(DecFirstIndLPChr) | 8.8.3.6 | +| DecIndLPChr0 = InitializeVLCTable2(DecIndLPChr0) | 8.8.3.6 | +| DecIndLPChr1 = InitializeVLCTable2(DecIndLPChr1) | 8.8.3.6 | +| AbsLevelIndLP0 = InitializeVLCTable1(AbsLevelIndLP0) | 8.8.3.5 | +| AbsLevelIndLP1 = InitializeVLCTable1(AbsLevelIndLP1) | 8.8.3.5 | +| } | | + +### 8.8.3.3 InitializeHPVLC() + +The pseudocode for the function InitializeHPVLC() is specified in Table 94. + +**Table 94 – Pseudocode for the function InitializeHPVLC()** + +| InitializeHPVLC() { | Reference | +|-----------------------------------------------------------------|------------------| +| DecFirstIndHPLum = InitializeVLCTable2(DecFirstIndHPLum) | 8.8.3.6 | +| DecIndHPLum0 = InitializeVLCTable2(DecIndHPLum0) | 8.8.3.6 | +| DecIndHPLum1 = InitializeVLCTable2(DecIndHPLum1) | 8.8.3.6 | +| DecFirstIndHPChr = InitializeVLCTable2(DecFirstIndHPChr) | 8.8.3.6 | +| DecIndHPChr0 = InitializeVLCTable2(DecIndHPChr0) | 8.8.3.6 | +| DecIndHPChr1 = InitializeVLCTable2(DecIndHPChr1) | 8.8.3.6 | +| AbsLevelIndHP0 = InitializeVLCTable1(AbsLevelIndHP0) | 8.8.3.5 | +| AbsLevelIndHP1 = InitializeVLCTable1(AbsLevelIndHP1) | 8.8.3.5 | +| } | | + +### 8.8.3.4 InitializeCBPHPVLC() + +The pseudocode for the function InitializeCBPHPVLC() is specified in Table 95. + +**Table 95 – Pseudocode for the function InitializeCBPHPVLC()** + +| InitializeCBPHPVLC() { | Reference | +|-------------------------------------------------------------|------------------| +| DecNumCBPHP = InitializeVLCTable1(DecNumCBPHP) | 8.8.3.5 | +| DecNumBlkCBPHP = InitializeVLCTable1(DecNumBlkCBPHP) | 8.8.3.5 | +| } | | + +8.8.3.5 InitializeVLCTable1() + +The pseudocode for the function InitializeVLCTable1() is specified in Table 96. + +Table 96 – Pseudocode for the function InitializeVLCTable1() + +| InitializeVLCTable1(sAdaptVLC) { | Reference | +|------------------------------------------------------------------|-----------| +| /* sAdaptVLC is an instance of the AdaptiveVLC data structure */ | | +| sAdaptVLC.TableIndex = 0 | | +| sAdaptVLC.DeltaTableIndex = 0 | | +| sAdaptVLC.DiscrimVal1 = 0 | | +| return sAdaptVLC | | +| } | | + +8.8.3.6 InitializeVLCTable2() + +The pseudocode for the function InitializeVLCTable2() is specified in Table 97. + +Table 97 – Pseudocode for the function InitializeVLCTable2() + +| InitializeVLCTable2(sAdaptVLC) { | Reference | +|------------------------------------------------------------------|-----------| +| /* sAdaptVLC is an instance of the AdaptiveVLC data structure */ | | +| sAdaptVLC.TableIndex = 1 | | +| sAdaptVLC.DeltaTableIndex = 0 | | +| sAdaptVLC.Delta2TableIndex = 1 | | +| sAdaptVLC.DiscrimVal1 = 0 | | +| sAdaptVLC.DiscrimVal2 = 0 | | +| return sAdaptVLC | | +| } | | + +8.8.4 Update of adaptive VLC code table selection + +The relevant adaptive VLC data structures that are associated with each of the three bands DC, LP and HP are updated by the functions AdaptDC(), AdaptLP() and AdaptHP(), respectively. The pseudocode for the functions AdaptDC(), AdaptLP() and AdaptHP() are specified in 8.8.4.1, 8.8.4.2 and 8.8.4.3, respectively: + +The functions AdaptLP() and AdaptHP() perform the updates by using the functions AdaptVLCTable1() and AdaptVLCTable2() which are specified in 8.8.4.4 and 8.8.4.5. + +8.8.4.1 AdaptDC() + +The pseudocode for the function AdaptDC() is specified in Table 98. + +Table 98 – Pseudocode for the function AdaptDC() + +| AdaptDC() { | Reference | +|-----------------------------------------------------|-----------| +| AbsLevelIndDCLum = AdaptVLCTable1(AbsLevelIndDCLum) | 8.8.4.4 | +| AbsLevelIndDCChr = AdaptVLCTable1(AbsLevelIndDCChr) | 8.8.4.4 | +| } | | + +### 8.8.4.2 AdaptLP() + +The pseudocode for the function AdaptLP() is specified in Table 99. + +**Table 99 – Pseudocode for the function AdaptLP()** + +| AdaptLP() { | Reference | +|---------------------------------------------------------------|------------------| +| DecFirstIndLPLum = AdaptVLCTable2(DecFirstIndLPLum, 4) | 8.8.4.5 | +| DecIndLPLum0 = AdaptVLCTable2(DecIndLPLum0, 3) | 8.8.4.5 | +| DecIndLPLum1 = AdaptVLCTable2(DecIndLPLum1, 3) | 8.8.4.5 | +| DecFirstIndLPChr = AdaptVLCTable2(DecFirstIndLPChr, 4) | 8.8.4.5 | +| DecIndLPChr0 = AdaptVLCTable2(DecIndLPChr0, 3) | 8.8.4.5 | +| DecIndLPChr1 = AdaptVLCTable2(DecIndLPChr1, 3) | 8.8.4.5 | +| AbsLevelIndLP0 = AdaptVLCTable1(AbsLevelIndLP0) | 8.8.4.4 | +| AbsLevelIndLP1 = AdaptVLCTable1(AbsLevelIndLP1) | 8.8.4.4 | +| } | | + +### 8.8.4.3 AdaptHP() + +The pseudocode for the function AdaptHP() is specified in Table 100. + +**Table 100 – Pseudocode for the function AdaptHP()** + +| AdaptHP() { | Reference | +|---------------------------------------------------------------|------------------| +| DecFirstIndHPLum = AdaptVLCTable2(DecFirstIndHPLum, 4) | 8.8.4.5 | +| DecIndHPLum0 = AdaptVLCTable2(DecIndHPLum0, 3) | 8.8.4.5 | +| DecIndHPLum1 = AdaptVLCTable2(DecIndHPLum1, 3) | 8.8.4.5 | +| DecFirstIndHPChr = AdaptVLCTable2(DecFirstIndHPChr, 4) | 8.8.4.5 | +| DecIndHPChr0 = AdaptVLCTable2(DecIndHPChr0, 3) | 8.8.4.5 | +| DecIndHPChr1 = AdaptVLCTable2(DecIndHPChr1, 3) | 8.8.4.5 | +| AbsLevelIndHP0 = AdaptVLCTable1(AbsLevelIndHP0) | 8.8.4.4 | +| AbsLevelIndHP1 = AdaptVLCTable1(AbsLevelIndHP1) | 8.8.4.4 | +| DecNumCBPHP = AdaptVLCTable1(DecNumCBPHP) | 8.8.4.4 | +| DecNumBlkCBPHP = AdaptVLCTable1(DecNumBlkCBPHP) | 8.8.4.4 | +| } | | + +### 8.8.4.4 AdaptVLCTable1() + +AdaptVLCTable1() is used for choosing VLC code tables when there are exactly two code tables. In this case, the index TableIndex takes only the values 0 or 1, and there is only one parameter (DiscrimVal1) which determines the selection of VLC code tables. DeltaTableIndex takes only the value 0, and there is only the one deltaDisc table. + +The pseudocode for the function AdaptVLCTable1() is specified in Table 101. + +**Table 101 – Pseudocode for the function AdaptVLCTable1()** + +| AdaptVLCTable1(sAdaptVLC) { | Reference | +|-------------------------------------------------------------------------------------------------------------------|------------------| +| /* sAdaptVLC is an instance of the AdaptiveVLC data structure */ | | +| iMaxTableIndex = 1 /* Only two code tables */ | | +| cLowerBound = -8 | | +| cUpperBound = 8 | | +| /* sAdaptVLC.DeltaTableIndex = 0, since only 2 code tables */ | | +| if (sAdaptVLC.DiscrimVal1 < cLowerBound &&
sAdaptVLC.TableIndex != 0) { | | +| sAdaptVLC.TableIndex-- | | +| sAdaptVLC.DiscrimVal1 = 0 | | +| } else if (sAdaptVLC.DiscrimVal1 > cUpperBound &&
sAdaptVLC.TableIndex != iMaxTableIndex) { | | +| sAdaptVLC.TableIndex++ | | +| sAdaptVLC.DiscrimVal1 = 0 | | +| } else { | | + +| | | +|-----------------------------------------------------|--| +| /* no change to table, but clip the discriminant */ | | +| if (sAdaptVLC.DiscrimVal1 < -64) | | +| sAdaptVLC.DiscrimVal1 = -64 | | +| if (sAdaptVLC.DiscrimVal1 > 64) | | +| sAdaptVLC.DiscrimVal1 = 64 | | +| } | | +| return sAdaptVLC | | +| } | | + +#### 8.8.4.5 AdaptVLCTable2() + +AdaptVLCTable2() is used for choosing VLC code tables when there are more than two possible code tables. In this case, the index TableIndex can take values between 0 and the maximum table index for that set of VLC code tables. This maximum table index is contained in the parameter iMaxTableIndex. For AdaptVLCTable2(), there are two parameters (DiscrimVal1 and DiscrimVal2) which determine the selection of VLC code tables. DiscrimVal1 determines whether the code table index should be decreased, while DiscrimVal2 determines whether the code table index should be increased. + +The pseudocode for the function Adapt VLCTable2() is specified in Table 102. + +**Table 102 – Pseudocode for the function AdaptVLCTable2()** + +| AdaptVLCTable2(sAdaptVLC, iMaxTableIndex) { | Reference | +|------------------------------------------------------------------------------------|------------------| +| /* sAdaptVLC is an instance of the AdaptiveVLC struct */ | | +| /* iMaxTableIndex – max table index possible for this struct instance */ | | +| bChange = FALSE | | +| iDiscrimLow = sAdaptVLC.DiscrimVal1 | | +| iDiscrimHigh = sAdaptVLC.DiscrimVal2 | | +| cLowerBound = -8 | | +| cUpperBound = 8 | | +| if (iDiscrimLow < cLowerBound && sAdaptVLC.TableIndex != 0) { | | +| sAdaptVLC.TableIndex-- | | +| bChange = TRUE | | +| } else if (iDiscrimHigh > cUpperBound && sAdaptVLC.TableIndex != iMaxTableIndex) { | | +| sAdaptVLC.TableIndex++ | | +| bChange = TRUE | | +| } | | +| if (bChange) { | | +| sAdaptVLC.DiscrimVal1 = 0 | | +| sAdaptVLC.DiscrimVal2 = 0 | | +| if (sAdaptVLC.TableIndex == iMaxTableIndex) { | | +| sAdaptVLC.DeltaTableIndex = sAdaptVLC.TableIndex - 1 | | +| sAdaptVLC.Delta2TableIndex = sAdaptVLC.TableIndex - 1 | | +| } else if (sAdaptVLC.TableIndex == 0) { | | +| sAdaptVLC.DeltaTableIndex = sAdaptVLC.TableIndex | | +| sAdaptVLC.Delta2TableIndex = sAdaptVLC.TableIndex | | +| } else { | | +| sAdaptVLC.DeltaTableIndex = sAdaptVLC.TableIndex - 1 | | +| sAdaptVLC.Delta2TableIndex = sAdaptVLC.TableIndex | | +| } | | +| } else { /* no change to table, but clip the discriminant */ | | +| if (sAdaptVLC.DiscrimVal1 < -64) | | +| sAdaptVLC.DiscrimVal1 = -64 | | +| if (sAdaptVLC.DiscrimVal1 > 64) | | +| sAdaptVLC.DiscrimVal1 = 64 | | +| if (sAdaptVLC.DiscrimVal2 < -64) | | +| sAdaptVLC.DiscrimVal2 = -64 | | +| if (sAdaptVLC.DiscrimVal2 > 64) | | +| sAdaptVLC.DiscrimVal2 = 64 | | +| } | | +| return sAdaptVLC | | +| } | | + +## 8.9 Adaptation of CBPLP state variables + +### 8.9.1 General + +The parsing of CBPLP depends on the value of the variables CountZeroCBPLP and CountMaxCBPLP. The functions specified in this subclause specify the initialization and updating of these constants. + +### 8.9.2 InitializeCountCBPLP() + +The variable CountZeroCBPLP and CountMaxCBPLP for LP coefficients are initialized by the function InitializeCountCBPLP() specified in Table 103. + +**Table 103 – Pseudocode for function InitializeCountCBPLP()** + +| InitializeCountCBPLP() { | Reference | +|--------------------------|-----------| +| CountZeroCBPLP = 1 | | +| CountMaxCBPLP = 1 | | +| } | | + +### 8.9.3 UpdateCountCBPLP() + +The function UpdateCountCBPLP() updates the variables CountZeroCBPLP and CountMaxCBPLP. The pseudocode for this function is specified in Table 104. + +**Table 104 – Pseudocode for function UpdateCountCBPLP()** + +| UpdateCountCBPLP(iCBPLP, iMax) { | Reference | +|--------------------------------------------------|-----------| +| CountZeroCBPLP += 1 - (4 * (iCBPLP == 0)) | | +| CountZeroCBPLP = Max(-8, Min(7, CountZeroCBPLP)) | | +| CountMaxCBPLP += 1 - (4 * (iCBPLP == iMax)) | | +| CountMaxCBPLP = Max(-8, Min(7, CountMaxCBPLP)) | | +| } | | + +## 8.10 Adaptive CBPHP prediction + +CBPHP prediction depends on the value of member variables of the data structure instance **CBPHPModelHP**. The functions specified in this subclause specify the initialization and updating of this data structure. + +### 8.10.1 InitializeCBPHPModel() + +The data structure instance **CBPHPModelHP** is initialized in the function InitializeCBPHPModel() specified in Table 105. + +**Table 105 – Pseudocode for function InitializeCBPHPModel()** + +| InitializeCBPHPModel() { | Reference | +|---------------------------------------------------------------|-----------| +| CBPHPModelHP.CBPHPState[0] = CBPHPModelHP.CBPHPState[1] = 0 | | +| CBPHPModelHP.CountOnes[0] = CBPHPModelHP.CountOnes[1] = -4 | | +| CBPHPModelHP.CountZeroes[0] = CBPHPModelHP.CountZeroes[1] = 4 | | +| } | | + +### 8.10.2 UpdateCBPHPModel() + +The variables associated with the data structure instance **CBPHPModelHP** are updated by the function UpdateCBPHPModel() as specified in Table 106. + +**Table 106 – Pseudocode for function UpdateCBPHPModel()** + +| UpdateCBPHPModel(i, iNOrig) { | Reference | +|---------------------------------------------------------------------------------|------------------| +| iNDiff = 3 | | +| CBPHPModelHP.CountOnes[i] += iNOrig – iNDiff | | +| CBPHPModelHP.CountOnes[i] = Clip(CBPHPModelHP.CountOnes[i], –16,15) | | +| CBPHPModelHP.CountZeroes[i] += 16 – iNOrig – iNDiff | | +| CBPHPModelHP.CountZeroes[i] = Clip(CBPHPModelHP.CountZeroes[i], –16, 15) | | +| if (CBPHPModelHP.CountOnes[i] < 0) | | +| if (CBPHPModelHP.CountOnes[i] < CBPHPModelHP.CountZeroes[i]) | | +| CBPHPModelHP.CBPHPState[i] = 1 | | +| else | | +| CBPHPModelHP.CBPHPState[i] = 2 | | +| else if (CBPHPModelHP.CountZeroes[i] < 0) | | +| CBPHPModelHP.CBPHPState[i] = 2 | | +| else | | +| CBPHPModelHP.CBPHPState[i] = 0 | | +| } | | + +## 8.11 Adaptive inverse scanning + +The parsing of syntax elements corresponding to LP and HP coefficients depends on the state of the inverse scanning tables LowpassScanOrder[i], HighpassHorScanOrder[i], and HighpassVerScanOrder[i]. The functions specified in this subclause define the initialization and updating of these tables. + +### 8.11.1 Adaptive inverse scanning tables + +The inverse scanning order of transform coefficients is a permutation of the integers 1 to 15. Let the integer i represent the order in which a given transform coefficient is parsed from the codestream, and let the local example list listScanOrder[ ] specify an inverse scanning order as follows: the i-th transform coefficient is put into the block in the j-th position in raster scan order, where j is equal to listScanOrder[i]. + +The three lists LowpassScanOrder[ ], HighpassHorScanOrder[ ] and HighpassVerScanOrder[ ] are used to specify the inverse scanning order of LP coefficients, HP coefficients in the case of prediction from the left (9.6) and HP coefficients in the case of prediction from the top, respectively. These lists are initialized to scan orders as specified in the following. However, the lists are adaptive, and thus may change over the course of parsing, based on the statistics of non-zero transform coefficients in the codestream. + +The three lists LowpassScanOrder[ ], HighpassHorScanOrder[ ] and HighpassVerScanOrder[ ] are initialized as specified in 8.11.2 and 8.11.3. The initial orders are specified by the two lists ScanOrder0[ ] and ScanOrder1[ ], which are specified in Table 107. + +**Table 107 – Definitions of ScanOrder0 and ScanOrder1** + +| i | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | +|----------------------|----------|----------|----------|----------|----------|----------|----------|----------|----------|-----------|-----------|-----------|-----------|-----------|-----------| +| ScanOrder0[i] | 4 | 1 | 5 | 8 | 2 | 9 | 6 | 12 | 3 | 10 | 13 | 7 | 14 | 11 | 15 | +| ScanOrder1[i] | 1 | 2 | 5 | 4 | 3 | 6 | 9 | 8 | 7 | 12 | 15 | 13 | 10 | 11 | 14 | + +Each of the lists LowpassScanOrder[ ], HighpassHorScanOrder[ ] and HighpassVerScanOrder[ ] also has an associated list that determines how the scan order is updated. These corresponding lists are LowpassTotals[ ], HighpassHorTotals[ ] and HighpassVerTotals[ ], respectively. These associated lists are initialized to be equal to the list ScanTotals[ ], which is specified in Table 108. + +**Table 108 – Definition of ScanTotals** + +| i | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | +|----------------------|----------|----------|----------|----------|----------|----------|----------|----------|----------|-----------|-----------|-----------|-----------|-----------|-----------| +| ScanTotals[i] | 32 | 30 | 28 | 26 | 24 | 22 | 20 | 18 | 16 | 14 | 12 | 10 | 8 | 6 | 4 | + +The three lists LowpassScanOrder[ ], HighpassHorScanOrder[ ] and HighpassVerScanOrder[ ] are updated as specified in 8.11. + +### 8.11.2 InitializeAdaptiveScanLP() + +The adaptive inverse scanning tables for LP coefficients are initialized in the function InitializeAdaptiveScanLP() specified in Table 109. + +**Table 109 – Pseudocode for function InitializeAdaptiveScanLP()** + +| InitializeAdaptiveScanLP() { | Reference | +|-------------------------------------|-----------------------------------| +| for (i = 1; i <= 15; i++) { | | +| LowpassScanOrder[i] = ScanOrder0[i] | ScanOrder0[i] specified in 8.11.1 | +| LowpassTotals[i] = ScanTotals[i] | ScanTotals[i] specified in 8.11.1 | +| } | | +| } | | + +### 8.11.3 InitializeAdaptiveScanHP() + +The adaptive inverse scanning tables for HP coefficients are initialized in the function InitializeAdaptiveScanHP() specified in Table 110. + +**Table 110 – Pseudocode for function InitializeAdaptiveScanHP()** + +| InitializeAdaptiveScanHP() { | Reference | +|-----------------------------------------|-----------------------------------| +| for (i = 1; i <= 15; i++) { | | +| HighpassHorScanOrder[i] = ScanOrder0[i] | ScanOrder0[i] specified in 8.11.1 | +| HighpassVerScanOrder[i] = ScanOrder1[i] | ScanOrder1[i] specified in 8.11.1 | +| HighpassHorTotals[i] = ScanTotals[i] | ScanTotals[i] specified in 8.11.1 | +| HighpassVerTotals[i] = ScanTotals[i] | ScanTotals[i] specified in 8.11.1 | +| } | | +| } | | + +### 8.11.4 ResetTotalsAdaptiveScanLP() + +The list LowpassTotals of the adaptive inverse scanning tables for LP coefficients is reset in the function ResetTotalsAdaptiveScanLP() specified in Table 111. + +**Table 111 – Pseudocode for function ResetTotalsAdaptiveScanLP()** + +| ResetTotalsAdaptiveScanLP() { | Reference | +|--------------------------------------|-----------------------------------| +| for (i = 1; i <= 15; i++) | | +| LowpassTotals[i] = ScanTotals[i] | ScanTotals[i] specified in 8.11.1 | +| } | | + +### 8.11.5 ResetTotalsAdaptiveScanHP() + +The lists HighpassHorTotals and HighpassVerTotals of the adaptive inverse scanning tables for HP coefficients are reset in the function ResetTotalsAdaptiveScanHP() specified in Table 112. + +**Table 112 – Pseudocode for function ResetTotalsAdaptiveScanHP()** + +| ResetTotalsAdaptiveScanHP() { | Reference | +|--------------------------------------|-----------------------------------| +| for (i = 1; i <= 15; i++) { | | +| HighpassHorTotals[i] = ScanTotals[i] | ScanTotals[i] specified in 8.11.1 | +| HighpassVerTotals[i] = ScanTotals[i] | ScanTotals[i] specified in 8.11.1 | +| } | | +| } | | + +### 8.11.6 AdaptiveLPScan() + +The function AdaptiveLPScan ( ) updates the list LPInput[k] and also updates the variables associated with tracking and modifying the LP scan order LowpassScanOrder[i] as specified in Table 113. + +**Table 113 – Pseudocode for function AdaptiveLPScan()** + +| AdaptiveLPScan(n, i, iValue) { | Reference | +|-----------------------------------------------------------|------------------| +| k = LowpassScanOrder[i] | | +| LPInput[n][k] = iValue | | +| LowpassTotals[i]++ | | +| if ((i > 1) && (LowpassTotals[i] > LowpassTotals[i-1])) { | | +| valueTemp = LowpassTotals[i] | | +| LowpassTotals[i] = LowpassTotals[i-1] | | +| LowpassTotals[i-1] = valueTemp | | +| valueTemp = LowpassScanOrder[i] | | +| LowpassScanOrder[i] = LowpassScanOrder[i-1] | | +| LowpassScanOrder[i-1] = valueTemp | | +| } | | +| } | | + +### 8.11.7 AdaptiveHPScan() + +The function AdaptiveHPScan ( ) updates the list HPInputVLC[iComponent][iBlock][k], and also updates the variables associated with tracking and modifying the HP scan orders HighpassHorScanOrder[i] and HighpassVerScanOrder[i] as specified in Table 114. + +**Table 114 – Pseudocode for function AdaptiveHPScan()** + +| AdaptiveHPScan(iComponent, iBlock, i, iValue) { | Reference | +|--------------------------------------------------------|------------------| +| if (MBHPMode == 1) { /* vertical scan order */ | | +| k = HighpassVerScanOrder[i] | | +| HighpassVerTotals[i]++ | | +| HPInputVLC[iComponent][iBlock][k] = iValue | | +| if ((i > 1) && | | +| (HighpassVerTotals[i] > HighpassVerTotals[i-1])) { | | +| valueTemp = HighpassVerTotals[i] | | +| HighpassVerTotals[i] = HighpassVerTotals[i-1] | | +| HighpassVerTotals[i-1] = valueTemp | | +| valueTemp = HighpassVerScanOrder[i] | | +| HighpassVerScanOrder[i] = HighpassVerScanOrder[i-1] | | +| HighpassVerScanOrder[i-1] = valueTemp | | +| } | | +| } else { /* horizontal scan order */ | | +| k = HighpassHorScanOrder[i] | | +| HighpassHorTotals[i]++ | | +| HPInputVLC[iComponent][iBlock][k] = iValue | | +| if ((i > 1) && | | +| (HighpassHorTotals[i] > HighpassHorTotals[i-1])) { | | +| valueTemp = HighpassHorTotals[i] | | +| HighpassHorTotals[i] = HighpassHorTotals[i-1] | | +| HighpassHorTotals[i-1] = valueTemp | | +| valueTemp = HighpassHorScanOrder[i] | | +| HighpassHorScanOrder[i] = HighpassHorScanOrder[i-1] | | +| HighpassHorScanOrder[i-1] = valueTemp | | +| } | | +| } | | +| } | | + +The variable MBHPMode is computed during the HP prediction direction computation process specified in 9.6.3.2. The scan order is selected based on the value of the variable MBHPMode. AdaptiveHPScan ( ) shall only be invoked on a + +macroblock after the HP prediction direction computation process specified in 9.6.3.2 has been invoked and completed for this macroblock. The HP prediction direction process shall be invoked only after the completion of the LP transform coefficient parsing process. + +NOTE – See 9.6 for more information. + +## 8.12 Adaptive coefficient normalization + +### 8.12.1 InitializeModelMB() + +The initialization of the **Model** data structure is specified by the function InitializeModelMB() as specified in Table 115. + +**Table 115 – Pseudocode for function InitializeModelMB()** + +| InitializeModelMB(Model, iBand) { | Reference | +|-------------------------------------------------------------------|------------------| +| /* iBand is the frequency band (DC = 0, LP = 1, HP = 2) */ | | +| Model.MState[0] = Model.MState[1] = 0 | | +| Model.MBits[0] = Model.MBits[1] = (2 – iBand) * 4 | | +| } | | + +### 8.12.2 UpdateModelMB() + +The adaptation of the **Model** data structure is specified by the function UpdateModelMB() as specified in Table 116. + +**Table 116 – Pseudocode for function UpdateModelMB()** + +| UpdateModelMB(iLapMean[], Model, iBand) { | Reference | +|---------------------------------------------------------------------------|------------------| +| /* INTERNAL_CLR_FMT is the colour format of the image */ | | +| /* iBand is the frequency band (DC = 0, LP = 1, HP = 2) */ | | +| iModelWeight = 70 | | +| iWeight0[3] = {240 /*DC*/, 12 /*LP*/, 1} | | +| iWeight1[3][MAX_COMPONENTS] = { | | +| {0, 240, 120, 80, 60, 48, 40, 34, 30, 27, 24, 22, 20, 18, 17, 16}, | | +| {0, 12, 6, 4, 3, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1}, | | +| {0, 16, 8, 5, 4, 3, 3, 2, 2, 2, 2, 1, 1, 1, 1, 1} | | +| } | | +| iWeight2[6] = {120, 37, 2 /*YUV420*/, 120, 18, 1 /*YUV422*/} | | +| iLapMean[0] *= iWeight0[iBand] | | +| if (INTERNAL_CLR_FMT == YUV420) | | +|     iLapMean[1] *= iWeight2[iBand] | | +| else if (INTERNAL_CLR_FMT == YUV422) | | +|     iLapMean[1] *= iWeight2[3 + iBand] | | +| else { | | +|     iLapMean[1] *= iWeight1[iBand][NumComponents – 1] | | +|     if (iBand == 2) | | +|         iLapMean[1] >>= 4 | | +| } | | +| iNumModels = 2 | | +| if (INTERNAL_CLR_FMT == YONLY) | | +|     iNumModels = 1 | | +| for (j = 0; j < iNumModels; j++) { | | +|     iMS = Model.MState[j] | | +|     iDelta = ((iLapMean[j] – iModelWeight) >> 2) | | +|     if (iDelta <= –8) { | | +|         iDelta += 4 | | +|         if (iDelta < –16) | | +|             iDelta = –16 | | +|         iMS += iDelta | | +|         if (iMS < –8) | | +|             if (Model.MBits[j] == 0) | | +|                 iMS = –8 | | +|         else { | | +|             iMS = 0 | | +|         Model.MBits[j]– – | | + +| UpdateModelMB(iLapMean[ ], Model, iBand) { | Reference | +|---------------------------------------------------|------------------| +| } | | +| } else if (iDelta >= 8) { | | +| iDelta -= 4 | | +| if (iDelta > 15) | | +| iDelta = 15 | | +| iMS += iDelta | | +| if (iMS > 8) { | | +| if (Model.MBits[j] >= 15) { | | +| Model.MBits[j] = 15 | | +| iMS = 8 | | +| } else { | | +| iMS = 0 | | +| Model.MBits[j]++ | | +| } | | +| } | | +| Model.MState[j] = iMS | | +| } | | +| } | | + +## 9 Decoding process + +### 9.1 General + +This clause specifies the decoding process. The decoding process is interdependent with the initialization of variables and parsing of syntax elements as specified in clause 8. + +The decoding process specified in this clause is distinguished from the codestream parsing process in the following manner: the codestream parsing process manages all control flow regarding the correct parsing of codestream syntax elements. This includes maintaining state variables for adaptive VLC selection, adaptive coefficient normalization, and other related information. The processes in this clause therefore are written with the assumption that, when they are invoked, the input variables required for this process have been correctly parsed from the codestream. + +The decoding process is specified so that the decoded samples from any two JPEG XR decoders will be numerically identical. Any decoder which produces results that match the process specified here conforms to the requirements of this Specification. + +The image decoding process proceeds as specified in clause 9.2. + +### 9.2 Image decoding + +The outputs of this process are the output samples of the image. + +The image decoding process proceeds as specified in Table 117. + +**Table 117 – Pseudocode for function ImageDecoding( )** + +| ImageDecoding( ) { | Reference | +|----------------------------------------------------------------------------------------------------------------------------------------------|------------------| +| ImagePlaneDecoding( )
/* resulting sample values are stored in the variables ImagePlane[i][x][y] */ | 9.3 | +| if ((OUTPUT_CLR_FMT == RGB) &&
((OUTPUT_BITDEPTH == BD5) (OUTPUT_BITDEPTH == BD565)
(OUTPUT_BITDEPTH == BD10))) /* Packed RGB */ | | +| outputArrays = 1 | | +| else if ((OUTPUT_CLR_FMT == RGB) (OUTPUT_CLR_FMT == YUV444)
(OUTPUT_CLR_FMT == YUV422) (OUTPUT_CLR_FMT == YUV420)) | | +| outputArrays = 3 | | +| else if (OUTPUT_CLR_FMT == RGBE) | | +| outputArrays = 4 | | +| else | | +| outputArrays = NumComponents | | + +| ImageDecoding( ) { | Reference | +|---------------------------------------------------------------------------------------------------------------------------|------------------| +| for (i = 0; i < outputArrays; i++) { | | +| if ((i > 0) && (OUTPUT_CLR_FMT == YUV420)) | | +| outputHeight = (HEIGHT_MINUS1 + 1) / 2 | | +| else | | +| outputHeight = HEIGHT_MINUS1 + 1 | | +| if ((OUTPUT_BITDEPTH == BD1WHITE1)
(OUTPUT_BITDEPTH == BD1BLACK1)) /* Horizontally packed flags */ | | +| outputWidth = WIDTH_MINUS1 / 8 + 1 | | +| else if ((i > 0) &&
((OUTPUT_CLR_FMT == YUV422) (OUTPUT_CLR_FMT == YUV420))) | | +| outputWidth = (WIDTH_MINUS1 + 1) / 2 | | +| else | | +| outputWidth = WIDTH_MINUS1 + 1 | | +| for (y = 0; y < outputHeight; y++) | | +| for (x = 0; x < outputWidth; x++) | | +| ImagePrimary[i][x][y] = ImagePlane[i][x][y] | | +| } | | +| if (ALPHA_IMAGE_PLANE_FLAG == TRUE) { | | +| ImagePlaneDecoding( ) | 9.3 | +| /* resulting sample values, corresponding to the alpha image plane,
are stored in the variables ImagePlane[0][x][y] */ | | +| for (y = 0; y <= HEIGHT_MINUS1; y++) | | +| for (x = 0; x <= WIDTH_MINUS1; x++) | | +| ImageAlpha[0][x][y] = ImagePlane[0][x][y] | | +| } | | + +NOTE – Throughout the parsing of syntax elements in clause 8, it is assumed that if ALPHA\_IMAGE\_PLANE\_FLAG is equal to TRUE, there are two sets of parsed syntax elements: one set corresponding to the primary image plane and another to the alpha image plane. In the same manner, this subclause assumes that there are two sets of global variables being used in the decoding process, corresponding to the primary and alpha image planes, respectively. + +## 9.3 Image plane decoding + +This process is invoked for each image plane. + +The outputs of this process are the decoded samples for this image plane, ImagePlane[i][x][y]. + +The image plane decoding process proceeds as specified in Table 118. + +**Table 118 – Pseudocode for function ImagePlaneDecoding( )** + +| ImagePlaneDecoding( ) { | Reference | +|----------------------------------------------------------------------------------------------------------------|------------------| +| ImagePlaneDCQP( ) | 9.7.1.1 | +| ImagePlaneLPQP( ) | 9.7.2.1 | +| ImagePlaneHPQP( ) | 9.7.3.1 | +| for (TileIndexy = 0; TileIndexy < NumTileRows; TileIndexy++) | | +| for (TileIndexx = 0; TileIndexx < NumTileCols; TileIndexx++) { | | +| TileTransformCoefficientProcessing( ) | 9.4.1 | +| /* At this point, transform coefficients for the entire image plane have
been obtained */ | | +| SampleReconstruction( ) | 9.9.1 | +| /* This process performs both levels of the inverse transform and overlap
operations on the entire image */ | | +| OutputFormatting( ) | 9.10.2 | +| } | | + +## 9.4 Tile transform coefficient processing + +### 9.4.1 Overview + +This process is invoked for each tile. The inputs to this process are the horizontal and vertical indices of the current tile. + +The outputs of this process are transform coefficients for each macroblock in the tile. + +The transform coefficient processing proceeds as specified in Table 119. + +**Table 119 – Pseudocode for function TileTransformCoefficientProcessing()** + +| TileTransformCoefficientProcessing() { | Reference | +|---------------------------------------------------------------------------------------------|------------------| +| TileLevelDCQP() | 9.7.1.2 | +| TileLevelLPQP() | 9.7.2.2 | +| TileLevelHPQP() | 9.7.3.2 | +| n = 0 | | +| for (MBy = TopMBIndexOfTile[TileIndexy]; MBy < TopMBIndexOfTile[TileIndexy + 1]; MBy++) | | +| for (MBx = LeftMBIndexOfTile[TileIndexx]; MBx < LeftMBIndexOfTile[TileIndexx + 1]; MBx++) { | | +| MBQPIndexLP[MBx][MBy] = LP_QP_INDEX[n] | | +| MBQPIndexHP[MBx][MBy] = HP_QP_INDEX[n] | | +| DCTransformCoefficientDecoding() | 9.4.2 | +| LPTransformCoefficientDecoding() | 9.4.3 | +| HPTransformCoefficientDecoding() | 9.4.4 | +| n += 1 | | +| } | | +| } | | + +NOTE – The computation of the global variable MBHPMode is dependent upon the completion of the LP transform coefficient decoding process. MBHPMode is computed at the beginning of the HP coefficient decoding process. + +#### 9.4.2 DC transform coefficient decoding + +The outputs of this process are DC transform coefficients for each colour component of the current macroblock. + +The DC transform coefficient processing proceeds as specified in Table 120. + +**Table 120 – Pseudocode for function DCTransformCoefficientDecoding()** + +| DCTransformCoefficientDecoding() { | Reference | +|-------------------------------------------|------------------| +| DCMBCoefficientRemap() | 9.5.1 | +| DCPredictionGeneral() | 9.6.1.1 | +| DequantizeDCCoefficients() | 9.8.1 | +| } | | + +#### 9.4.3 Lowpass transform coefficient decoding + +The outputs of this process are LP transform coefficients for each colour component of the current macroblock. + +The LP transform coefficient processing proceeds as specified in Table 121. + +**Table 121 – Pseudocode for function LPTransformCoefficientDecoding()** + +| LPTransformCoefficientDecoding() { | Reference | +|-------------------------------------------|------------------| +| LPMBCoefficientRemap() | 9.5.2 | +| LPPredictionGeneral() | 9.6.2.1 | +| DequantizeLPCoefficients() | 9.8.2 | +| } | | + +#### 9.4.4 Highpass transform coefficient decoding + +Input to this process is the value of MBHPMode for the current macroblock. + +The outputs of this process are HP transform coefficients for each colour component of the current macroblock. + +The HP transform coefficient processing proceeds as specified in Table 122. + +**Table 122 – Pseudocode for function HPTransformCoefficientDecoding( )** + +| HPTransformCoefficientDecoding( ) { | Reference | +|--------------------------------------------|------------------| +| CalcHPPredMode( ) | 9.6.3.2 | +| HPMBCoefficientRemap( ) | 9.5.3 | +| DequantizeHPCoefficients( ) | 9.8.3 | +| HPCoefficientPrediction( ) | 9.6.3.3 | +| } | | + +## 9.5 Coefficient remapping + +This subclause specifies the coefficient remapping processes for DC, LP and HP coefficients. + +### 9.5.1 DC coefficient remapping + +Input to this process is a list DCInput[i] of DC level values for each colour component i, and the variables MBx and MBy, which identify the current macroblock. + +The output of this process is the list of values MbDCLP[MBx][MBy][i][0], of DC transform coefficients, for each colour component i of the current macroblock. + +NOTE – The values DCInput[j] are the outputs of the MB\_DC( ) syntax structure of 8.7.11. + +The values in the array MbDCLP[MBx][MBy][i][0] are set by Table 123. + +**Table 123 – Pseudocode for function DCMBCoefficientRemap( )** + +| DCMBCoefficientRemap( ) { | Reference | +|-------------------------------------|------------------| +| for (i = 0; i < NumComponents; i++) | | +| MbDCLP[MBx][MBy][i][0] = DCInput[i] | | +| } | | + +### 9.5.2 Lowpass coefficient remapping + +Inputs to this process are a list of variables LPInput[i][j] which hold the j-th LP transform coefficient value for each colour component i. + +The output of this process is the array of variables MbDCLP[MBx][MBy][i][j] which hold the j-th LP transform coefficients, indexed in raster scan order, of colour component i. + +The LP coefficient remapping process proceeds as specified in Table 124. + +**Table 124 – Pseudocode for function LPMBCoefficientRemap( )** + +| LPMBCoefficientRemap( ) { | Reference | +|-------------------------------------------------------------------------------|------------------| +| for (i = 0; i < NumComponents; i++) | | +| if (i != 0) && ((INTERNAL_CLR_FMT == YUV422) (INTERNAL_CLR_FMT == YUV420)) | | +| if (INTERNAL_CLR_FMT == YUV422) | | +| for (j = 1; j <= 7; j++) | | +| if (BANDS_PRESENT != DCONLY) | | +| MbDCLP[MBx][MBy][i][j] = LPInput[i][j] | | +| else | | +| MbDCLP[MBx][MBy][i][j] = 0 | | +| else /* INTERNAL_CLR_FMT == YUV420 */ | | +| for (j = 1; j <= 3; j++) | | +| if (BANDS_PRESENT != DCONLY) | | +| MbDCLP[MBx][MBy][i][j] = LPInput[i][j] | | +| else | | +| MbDCLP[MBx][MBy][i][j] = 0 | | +| else | | +| for (j = 1; j <= 15; j++) | | +| if (BANDS_PRESENT != DCONLY) | | +| MbDCLP[MBx][MBy][i][j] = LPInput[i][j] | | + +| LPMBCoefficientRemap() { | Reference | +|----------------------------|-----------| +| else | | +| MbDCLP[MBx][MBy][i][j] = 0 | | +| } | | + +### 9.5.3 Highpass macroblock coefficient remapping + +The HP coefficient remapping process proceeds as specified in Table 125. + +**Table 125 – Pseudocode for function HPMBCoefficientRemap()** + +| HPMBCoefficientRemap() { | Reference | +|------------------------------------------------|-----------| +| for (i = 0; i < NumComponents; i++) { | | +| if (i != 0 && INTERNAL_CLR_FMT == YUV420) | | +| jMax = 3 | | +| else if (i != 0 && INTERNAL_CLR_FMT == YUV422) | | +| jMax = 7 | | +| else | | +| jMax = 15 | | +| for (j = 0; j <= jMax; j++) | | +| HPBlockCoefficientRemap(i, j) | 9.5.4 | +| } | | +| } | | + +### 9.5.4 Highpass block coefficient remapping + +Inputs to this process are: the array HPInputVLC[currentComponent][blkIndex][j] for the current colour component currentComponent, and the current block index blkIndex, with j ranging from 1 to 15, the array HPInputFlex[currentComponent][blkIndex][j] for the current colour component currentComponent, and the current block index blkIndex, with j ranging from 1 to 15, the variable ModelBits[MBx][MBy], representing the number of flexbits for the current macroblock, and the variables MBx and MBy, which identify the current macroblock. + +Outputs of this process are the values MBBuffer[MBx][MBy][currentComponent][k] of HP transform coefficients, with k ranging from (16 \* blkIndex + 1) to (16 \* blkIndex + 15), corresponding to the current block. Pseudocode for this process is specified in Table 126. + +**Table 126 – Pseudocode for function HPBlockCoefficientRemap()** + +| HPBlockCoefficientRemap(currentComponent, blkIndex) { | Reference | +|------------------------------------------------------------------------------------------------------------------------------|-----------| +| if (currentComponent == 0) | | +| iIndex = 0 | | +| else | | +| iIndex = 1 | | +| for (j = 1; j <= 15; j++) { | | +| k = 16 * blkIndex + j | | +| if (BANDS_PRESENT == ALL
BANDS_PRESENT == NOFLEXBITS) | | +| MBBuffer[MBx][MBy][currentComponent][k] =
HPInputVLC[currentComponent][blkIndex][j] <<
ModelBitsMBHP[MBx][MBy][iIndex] | | +| else | | +| MBBuffer[MBx][MBy][currentComponent][k] = 0 | | +| if (BANDS_PRESENT == ALL) | | +| MBBuffer[MBx][MBy][currentComponent][k] +=
HPInputFlex[currentComponent][blkIndex][j] | | +| } | | +| } | | + +## 9.6 Transform coefficient prediction + +### 9.6.1 DC coefficient prediction + +### 9.6.1.1 Overview of DC prediction + +This subclause is informative: it is not an integral part of this Specification. + +Four modes are defined for the prediction of the DC coefficient of a macroblock. These modes are: + +- predict from left; +- predict from top; +- predict from left and top; +- no prediction. + +The prediction mode is determined from the position of the macroblock, as well as the DC values to the left, top and top-left of the macroblock. Furthermore, if the image has chroma components, the corresponding DC values of the chroma components are also used. + +### 9.6.1.2 DCPredictionGeneral() + +Inputs to this process are the Boolean variables IsMBLeftEdgeofTileFlag and IsMBTopEdgeofTileFlag, as well as the values MbDCLP[MBx][MBy][i][0], for each colour component i of the current macroblock. The variable IsMBLeftEdgeofTileFlag is equal to TRUE when the current macroblock is at the left edge of the tile; IsMBTopEdgeofTileFlag is equal to TRUE when the current macroblock is at the top edge of the current tile. + +NOTE – The values MbDCLP[MBx][MBy][i][0] come from the DC coefficient remapping process of clause 9.5.1. + +Outputs of this process are the updated values MbDCLP[MBx][MBy][i][0], for each colour component i of the current macroblock. + +The DC prediction process proceeds as specified in Table 127. + +**Table 127 – Pseudocode for function DCPredictionGeneral()** + +| DCPredictionGeneral() { | Reference | +|--------------------------------|------------------| +| CalcDCPredMode() | 9.6.1.3 | +| DCCoefficientPrediction() | 9.6.1.4 | +| UpdateDCPredictionVariables() | 9.6.1.5 | +| } | | + +### 9.6.1.3 DC prediction direction computation + +Inputs to this process are the variables IsMBLeftEdgeofTileFlag and IsMBTopEdgeofTileFlag, and the values PredDCLP[MBx-1][MBy][i][0], PredDCLP[MBx][MBy-1][i][0] and PredDCLP[MBx-1][MBy-1][i][0], for each colour component i. + +The output of this process is the value of MBDCMode. The possible values of MBDCMode are as follows: 0 specifies prediction from the left macroblock; 1 specifies prediction from the top macroblock; 2 specifies prediction from both the top and left macroblocks; and 3 specifies no prediction. + +The DC prediction direction process proceeds as specified in Table 128. + +**Table 128 – Pseudocode for function CalcDCPredMode()** + +| CalcDCPredMode() { | Reference | +|----------------------------------------------------------------------------------------|------------------| +| if (IsMBLeftEdgeofTileFlag == TRUE &&
IsMBTopEdgeofTileFlag == TRUE) | | +| MBDCMode = 3 /* no prediction */ | | +| else if (IsMBLeftEdgeofTileFlag == TRUE &&
IsMBTopEdgeofTileFlag == FALSE) | | +| MBDCMode = 1 /* prediction from top only */ | | +| else if (IsMBLeftEdgeofTileFlag == FALSE &&
IsMBTopEdgeofTileFlag == TRUE) | | +| MBDCMode = 0 /* prediction from left only */ | | +| else /* if (IsMBLeftEdgeofTileFlag == FALSE &&
IsMBTopEdgeofTileFlag == FALSE) */ { | | +| iLeft = PredDCLP[MBx-1][MBy][0][0] | | +| iTop = PredDCLP[MBx][MBy-1][0][0] | | +| iTopLeft = PredDCLP[MBx-1][MBy-1][0][0] | | + +| CalcDCPredMode() { | Reference | +|-------------------------------------------------------------------------------------------------|------------------| +| if (INTERNAL_CLR_FMT == Y_ONLY
INTERNAL_CLR_FMT == NCOMPONENT) { | | +| iStrHor = Abs(iTopLeft - iLeft) | | +| iStrVer = Abs(iTopLeft - iTop) | | +| } else { | | +| iLeftU = PredDCLP[MBx-1][MBy][1][0] | | +| iTopU = PredDCLP[MBx][MBy-1][1][0] | | +| iTopLeftU = PredDCLP[MBx-1][MBy-1][1][0] | | +| iLeftV = PredDCLP[MBx-1][MBy][2][0] | | +| iTopV = PredDCLP[MBx][MBy-1][2][0] | | +| iTopLeftV = PredDCLP[MBx-1][MBy-1][2][0] | | +| iScale = 2 | | +| if (INTERNAL_CLR_FMT == YUV420) | | +| iScale = 8 | | +| if (INTERNAL_CLR_FMT == YUV422) | | +| iScale = 4 | | +| iStrHor = Abs(iTopLeft - iLeft) * iScale +
Abs(iTopLeftU - iLeftU) + Abs(iTopLeftV - iLeftV) | | +| iStrVer = Abs(iTopLeft - iTop) * iScale +
Abs(iTopLeftU - iTopU) + Abs(iTopLeftV - iTopV) | | +| } | | +| iOrWt = 4 | | +| if ((iStrHor * iOrWt) < iStrVer) | | +| MBDCMode = 1 | | +| else if ((iStrVer * iOrWt) < iStrHor) | | +| MBDCMode = 0 | | +| else | | +| MBDCMode = 2 | | +| } | | +| } | | + +The value MBDCMode is used in subsequent stages of the DC prediction process. + +#### 9.6.1.4 DC coefficient prediction + +This process occurs when MBDCMode is not equal to 3. + +Inputs to this process are the variable MBDCMode representing the DC prediction direction, and the array variable MbDCLP[MBx][MBy][i][0] for each colour component i. + +Outputs to this process are the updated values MbDCLP[MBx][MBy][i][0], for each colour component i of the current macroblock. + +The DC coefficient prediction process proceeds as specified in Table 129. + +**Table 129 – Pseudocode for function DCCoefficientPrediction()** + +| DCCoefficientPrediction() { | Reference | +|----------------------------------------------------------------------------------|------------------| +| for (i = 0; i < NumComponents; i++) { | | +| iLeft = PredDCLP[MBx-1][MBy][i][0] | | +| iTop = PredDCLP[MBx][MBy-1][i][0] | | +| if (MBDCMode == 0) | | +| MbDCLP[MBx][MBy][i][0] += iLeft | | +| else if (MBDCMode == 1) | | +| MbDCLP[MBx][MBy][i][0] += iTop | | +| else if (MBDCMode == 2) { | | +| if (i == 0) ((INTERNAL_CLR_FMT != YUV420) &&
(INTERNAL_CLR_FMT != YUV422)) | | +| MbDCLP[MBx][MBy][i][0] += (iTop + iLeft) >> 1 | | +| else /* (INTERNAL_CLR_FMT == YUV420
INTERNAL_CLR_FMT == YUV422)*/ | | +| MbDCLP[MBx][MBy][i][0] +=
(iTop + iLeft + 1) >> 1 | | +| } | | +| } | | +| } | | + +### 9.6.1.5 Update of DC prediction variables + +Outputs of this process are the updated variables $\text{PredDCLP}[\text{MBx}][\text{MBy}][i]$ , for each colour component $i$ , where $\text{MBx}$ and $\text{MBy}$ are indexing the current macroblock. + +The update of DC prediction variables process proceeds as specified in Table 130. + +**Table 130 – Pseudocode for function UpdateDCPredictionVariables()** + +| UpdateDCPredictionVariables() { | Reference | +|-----------------------------------------------------------------------------------------------|-----------| +| for ( $i = 0$ ; $i < \text{NumComponents}$ ; $i++$ ) | | +| $\text{PredDCLP}[\text{MBx}][\text{MBy}][i][0] = \text{MbDCLP}[\text{MBx}][\text{MBy}][i][0]$ | | +| } | | + +## 9.6.2 Lowpass prediction + +### 9.6.2.1 Overview of lowpass prediction + +This subclause is informative: it is not an integral part of this Specification. + +Three modes are defined for the prediction of the LP coefficient of the inner transform of a macroblock. These modes are: + +- prediction from left when $\text{MBLPMODE}$ is equal to 0; +- prediction from top when $\text{MBLPMODE}$ is equal to 1; +- no prediction when $\text{MBLPMODE}$ is equal to 2. + +The LP coefficient prediction mode ( $\text{MBLPMODE}$ ) is determined by the DC coefficient prediction mode, together with the quantization parameters of both the current block and the block from which the DC values were predicted. + +This rule ensures that prediction of LP coefficients does not take place across macroblocks with different quantization parameters. + +Not all the LP coefficients associated with a macroblock are predicted. The definition and indices of DC and LP coefficients that are predicted are shown in Figure 5. The DC coefficient of the blocks shown in dark grey is at position 0 and the LP coefficients that can be predicted are shown in light grey. For the colour format YUV422, the LP coefficient associated with position 5 is predicted from position 1 in Figure 5, and if $\text{MBDCMODE}$ is equal to 1, irrespective of the value of $\text{MBLPMODE}$ , the LP coefficient associated with position 4 (indicated by crosshatching) can be predicted from both top and left. + +![Figure 5 shows three diagrams illustrating DC and LP coefficients for different macroblock sizes and chroma formats. (a) 4x4 block: A 4x4 grid of coefficients. Position 0 is dark grey (DC). Positions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 are light grey (LP). (b) 422 chroma block: A 2x2 grid of coefficients. Position 0 is dark grey (DC). Positions 1, 2, 3, 4, 5, 6, 7 are light grey (LP). Position 4 is crosshatched. (c) 420 chroma block: A 2x2 grid of coefficients. Position 0 is dark grey (DC). Positions 1, 2, 3 are light grey (LP).](8514933c69f6378f0567b77e4312a228_img.jpg) + +Figure 5 shows three diagrams illustrating DC and LP coefficients for different macroblock sizes and chroma formats. (a) 4x4 block: A 4x4 grid of coefficients. Position 0 is dark grey (DC). Positions 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 are light grey (LP). (b) 422 chroma block: A 2x2 grid of coefficients. Position 0 is dark grey (DC). Positions 1, 2, 3, 4, 5, 6, 7 are light grey (LP). Position 4 is crosshatched. (c) 420 chroma block: A 2x2 grid of coefficients. Position 0 is dark grey (DC). Positions 1, 2, 3 are light grey (LP). + +T.832(12)\_F05 + +**Figure 5 – DC and LP coefficients in: (a) 4x4; (b) 422 chroma; and (c) 420 chroma block** + +### 9.6.2.2 LPPredictionGeneral() + +Inputs to this process are the variable $\text{MBDCMODE}$ for the current macroblock, as well as the values $\text{MbDCLP}[\text{MBx}][\text{MBy}][i][j]$ , for each colour component $i$ of the current macroblock, and index $j$ referencing the LP transform coefficients, indexed in raster scan order. + +NOTE – The values $\text{MbDCLP}[\text{MBx}][\text{MBy}][i][j]$ come from the LP coefficient remapping process of 9.5.2. + +Outputs to this process are the values $\text{MbDCLP}[\text{MBx}][\text{MBy}][i][j]$ , for each colour component $i$ of the current macroblock. + +The LP prediction process proceeds as specified in Table 131. + +**Table 131 – Pseudocode for function LPPredictionGeneral()** + +| LPPredictionGeneral() { | Reference | +|--------------------------------|------------------| +| CalcLPPredMode( ) | 9.6.2.3 | +| LPCoefficientPrediction( ) | 9.6.2.4 | +| UpdateLPPredictionVariables( ) | 9.6.2.5 | +| } | | + +### 9.6.2.3 Lowpass prediction direction computation + +Inputs to this process are the variables MBDCMode and MBQPIndexLP[MBx][MBy]. + +The output to this process is the value of MBLPMode. The possible values of MBLPMode are as follows: the value 0 represents prediction from the left macroblock; the value 1 represents prediction from the top macroblock; and the value 2 represents no prediction. + +The LP prediction direction process proceeds as specified in Table 132. + +**Table 132 – Pseudocode for function CalcLPPredMode()** + +| CalcLPPredMode() { | Reference | +|--------------------------------------------------------------------------------|------------------| +| if (MBDCMode == 0 &&
MBQPIndexLP[MBx][MBy] == MBQPIndexLP[MBx-1][MBy]) | | +| MBLPMode = 0 | | +| else if (MBDCMode == 1 &&
MBQPIndexLP[MBx][MBy] == MBQPIndexLP[MBx][MBy-1]) | | +| MBLPMode = 1 | | +| else | | +| MBLPMode = 2 | | +| } | | + +### 9.6.2.4 Lowpass coefficient prediction + +Inputs to this process are: the variable MBLPMode representing the LP prediction direction; the variables MBx and MBy, which index the current macroblock in the image; and the variables PredDCLP[MBx][MBy][i][j]. + +Outputs to this process are the updated values MbDCLP[MBx][MBy][i][j], for each colour component i of the current macroblock, and j an index referencing the LP transform coefficients, indexed in raster scan order. + +The LP coefficient prediction process proceeds as specified in Table 133. + +**Table 133 – Pseudocode for function LPCoefficientPrediction()** + +| LPCoefficientPrediction() { | Reference | +|------------------------------------------------------------------------------------|------------------| +| for (i = 0; i < NumComponents; i++) { | | +| if (i == 0 ((INTERNAL_CLR_FMT != YUV420) &&
(INTERNAL_CLR_FMT != YUV422))) { | | +| if (MBLPMode == 0) { | | +| MbDCLP[MBx][MBy][i][4] += PredDCLP[MBx-1][MBy][i][4] | | +| MbDCLP[MBx][MBy][i][8] += PredDCLP[MBx-1][MBy][i][5] | | +| MbDCLP[MBx][MBy][i][12] += PredDCLP[MBx-1][MBy][i][6] | | +| } else if (MBLPMode == 1) { | | +| MbDCLP[MBx][MBy][i][1] += PredDCLP[MBx][MBy-1][i][1] | | +| MbDCLP[MBx][MBy][i][2] += PredDCLP[MBx][MBy-1][i][2] | | +| MbDCLP[MBx][MBy][i][3] += PredDCLP[MBx][MBy-1][i][3] | | +| } | | +| } else if (INTERNAL_CLR_FMT == YUV420) { /* i is equal to 1 or 2 here */ | | +| if (MBLPMode == 0) /* Prediction from left */ | | +| MbDCLP[MBx][MBy][i][2] += PredDCLP[MBx-1][MBy][i][2] | | +| else if (MBLPMode == 1) /* Prediction from top */ | | +| MbDCLP[MBx][MBy][i][1] += PredDCLP[MBx][MBy-1][i][1] | | +| } else if (INTERNAL_CLR_FMT == YUV422) /* i is equal to 1 or 2 here */ | | +| if (MBLPMode == 0) /* Prediction from left */ | | +| MbDCLP[MBx][MBy][i][4] += PredDCLP[MBx-1][MBy][i][4] | | + +| LPCoefficientPrediction() { | Reference | +|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------| +| MbDCLP[MBx][MBy][i][2] += PredDCLP[MBx-1][MBy][i][2] | | +| MbDCLP[MBx][MBy][i][6] += PredDCLP[MBx-1][MBy][i][6] | | +| } else if (MBLPMode == 1) { /* Prediction from top */ | | +| MbDCLP[MBx][MBy][i][4] += PredDCLP[MBx][MBy-1][i][4] | | +| MbDCLP[MBx][MBy][i][1] += PredDCLP[MBx][MBy-1][i][5] | | +| MbDCLP[MBx][MBy][i][5] += MbDCLP[MBx][MBy][i][1] | | +| /* In this line, prediction occurs using the current macroblock's data */ | | +| } else if (MBDCMode == 1) | | +| MbDCLP[MBx][MBy][i][5] += MbDCLP[MBx][MBy][i][1] | | +| /* When the colour format is YUV422,
MBLPMode is equal to 2 (no prediction), and
MBDCMode is equal to 1 (prediction from the top), the LP
coefficient associated with j=5 is predicted from that for j=1 */ | | +| } | | +| } | | + +### 9.6.2.5 Update of lowpass prediction variables + +Inputs to this process are the variables MBx and MBy, which index the current macroblock in the image. + +Outputs of this process are the variables PredDCLP[MBx][MBy][i][j], for each colour component i, and selected LP indices j. + +The update of LP prediction variables process proceeds as specified in Table 134. + +**Table 134 – Pseudocode for function UpdateLPPredictionVariables()** + +| UpdateLPPredictionVariables() { | Reference | +|------------------------------------------------------------------------------------|-----------| +| for (i = 0; i < NumComponents; i++) { | | +| if (i == 0 ((INTERNAL_CLR_FMT != YUV420) &&
(INTERNAL_CLR_FMT != YUV422))) { | | +| PredDCLP[MBx][MBy][i][1] = MbDCLP[MBx][MBy][i][1] | | +| PredDCLP[MBx][MBy][i][2] = MbDCLP[MBx][MBy][i][2] | | +| PredDCLP[MBx][MBy][i][3] = MbDCLP[MBx][MBy][i][3] | | +| PredDCLP[MBx][MBy][i][4] = MbDCLP[MBx][MBy][i][4] | | +| PredDCLP[MBx][MBy][i][5] = MbDCLP[MBx][MBy][i][8] | | +| PredDCLP[MBx][MBy][i][6] = MbDCLP[MBx][MBy][i][12] | | +| } else if (INTERNAL_CLR_FMT == YUV420) { | | +| PredDCLP[MBx][MBy][i][1] = MbDCLP[MBx][MBy][i][1] | | +| PredDCLP[MBx][MBy][i][2] = MbDCLP[MBx][MBy][i][2] | | +| } else if (INTERNAL_CLR_FMT == YUV422) { | | +| PredDCLP[MBx][MBy][i][1] = MbDCLP[MBx][MBy][i][1] | | +| PredDCLP[MBx][MBy][i][2] = MbDCLP[MBx][MBy][i][2] | | +| PredDCLP[MBx][MBy][i][4] = MbDCLP[MBx][MBy][i][4] | | +| PredDCLP[MBx][MBy][i][5] = MbDCLP[MBx][MBy][i][5] | | +| PredDCLP[MBx][MBy][i][6] = MbDCLP[MBx][MBy][i][6] | | +| } | | +| } | | +| } | | + +## 9.6.3 Highpass prediction + +### 9.6.3.1 Overview of highpass prediction + +This subclause is informative: it is not an integral part of this Specification. + +There are two prediction processes involving HP coefficients: the HP prediction direction process and the HP prediction process. The process that computes HP prediction direction also sets the HP direction variable MBHPMode, which determines the initial HP inverse scanning order. Therefore, the process that computes HP prediction direction shall be executed before the HP coefficient inverse scanning process. The HP prediction process is executed after the HP coefficient remapping process. + +Information in the LP transform coefficients is used to compute a simple metric to determine the *orientation* of prediction of HP coefficients associated with each macroblock. Three modes are defined for the prediction of the HP coefficients of the outer transform. The same mode is used for all blocks within a macroblock for which in-macroblock prediction is possible. For blocks that have no valid reference within the macroblock, null prediction is used. The three modes are: + +- prediction from left when MBHPMode is equal to 0; +- prediction from top when MBHPMode is equal to 1; +- no prediction when MBHPMode is equal to 2. + +Prediction from left is shown in Figure 6. Prediction from top is similar, with the pattern of arrows transposed to point downwards. + +![Figure 6: HP prediction from left. The diagram shows a 4x4 grid of macroblocks. Each macroblock is a 4x4 grid of coefficients. The first column of each macroblock is shaded dark grey, and the first three rows of the first column are numbered 1, 2, 3. The remaining three columns of each macroblock are numbered 4, 5, 6, 7 in the first row, 8, 9, 10, 11 in the second row, and 12, 13, 14, 15 in the third row. Blue arrows point from the first column of one macroblock to the first column of the next macroblock in the same row, illustrating prediction from the left. The grid is labeled T.832(12)_F06 at the bottom right.](da85343976fdbb19f866d9ddbdad0eae_img.jpg) + +Figure 6: HP prediction from left. The diagram shows a 4x4 grid of macroblocks. Each macroblock is a 4x4 grid of coefficients. The first column of each macroblock is shaded dark grey, and the first three rows of the first column are numbered 1, 2, 3. The remaining three columns of each macroblock are numbered 4, 5, 6, 7 in the first row, 8, 9, 10, 11 in the second row, and 12, 13, 14, 15 in the third row. Blue arrows point from the first column of one macroblock to the first column of the next macroblock in the same row, illustrating prediction from the left. The grid is labeled T.832(12)\_F06 at the bottom right. + +**Figure 6 – HP prediction from left** + +NOTE – In the implementation of a decoder, the only information that needs to be available for future use is 1 DC + 6 LP = 7 coefficients per macroblock component (fewer for YUV420 / YUV422 chrominance). Therefore, at most for YUV444, 21 coefficients need to be cached per macroblock. Furthermore, the coefficients used for prediction from left can be discarded after the next macroblock is predicted. For YUV444, therefore, it is necessary to only cache 12 coefficients per macroblock for use in the next row of macroblocks. More state is required on the encoder side: the HP coefficients must be maintained throughout this process, as the encoding of HP coefficients is dependent on the encoding of LP coefficients. + +### 9.6.3.2 Highpass prediction direction computation + +Inputs to this process are the variables MBx and MBy, indexing the location of the current macroblock in the image. + +The output of this process is the variable MBHPMode for the current macroblock. + +The HP prediction process proceeds as specified in Table 135. + +**Table 135 – Pseudocode for function CalcHPPredMode()** + +| CalcHPPredMode() { | Reference | +|----------------------------------------------------------------------------------------------------------|------------------| +| iStrHor = Abs(MbDCLP[MBx][MBy][0][1]) +
Abs(MbDCLP[MBx][MBy][0][2]) +
Abs(MbDCLP[MBx][MBy][0][3]) | | +| iStrVer = Abs(MbDCLP[MBx][MBy][0][4]) +
Abs(MbDCLP[MBx][MBy][0][8]) +
Abs(MbDCLP[MBx][MBy][0][12]) | | +| if ((INTERNAL_CLR_FMT != YONLY) &&
(INTERNAL_CLR_FMT != NCOMPONENT)) { | | +| for (i = 1; i <= 2; i++) { | | +| iStrHor += Abs(MbDCLP[MBx][MBy][i][1]) | | +| if (INTERNAL_CLR_FMT == YUV420) | | +| iStrVer += Abs(MbDCLP[MBx][MBy][i][2]) | | +| else if (INTERNAL_CLR_FMT == YUV422) { | | +| iStrVer += Abs(MbDCLP[MBx][MBy][i][2]) +
Abs(MbDCLP[MBx][MBy][i][6]) | | +| iStrHor += Abs(MbDCLP[MBx][MBy][i][5]) | | +| } else | | +| iStrVer += Abs(MbDCLP[MBx][MBy][i][4]) | | +| } | | +| } | | +| iOrWt = 4 | | +| if (iStrHor * iOrWt < iStrVer) | | +| MBHPMode = 0 /* predict from left */ | | +| else if (iStrVer * iOrWt < iStrHor) | | +| MBHPMode = 1 /* predict from top */ | | +| else | | +| MBHPMode = 2 /* no prediction */ | | +| } | | + +### 9.6.3.3 Highpass prediction + +Inputs to this process are: the variable MBHPMode, which indicates the HP prediction direction; the values MBx and MBy, which index the current macroblock in the image; and the values MBBuffer[MBx][MBy][i][j], which hold the HP transform coefficients obtained from the HP coefficient remapping process of 9.5.3. The outputs of this process are the updated values MBBuffer[MBx][MBy][i][k] of HP transform coefficients. + +The HP prediction process proceeds as specified in Table 136. + +**Table 136 – Pseudocode for function HPCoefficientPrediction()** + +| HPCoefficientPrediction() { | Reference | +|---------------------------------------------------------------------------------------------|------------------| +| if (INTERNAL_CLR_FMT == YUV420) (INTERNAL_CLR_FMT == YUV422) | | +| iComponents = 1 | | +| else | | +| iComponents = NumComponents | | +| for (i = 0; i < iComponents; i++) { | | +| if (MBHPMode == 0) { | | +| blkId[ ] = {1,2,3,5,6,7,9,10,11,13,14,15} | | +| for (j = 0; j < 12; j++) { | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 4] +=
MBBuffer[MBx][MBy][i][16*(blkId[j] - 1) + 4] | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 8] +=
MBBuffer[MBx][MBy][i][16*(blkId[j] - 1) + 8] | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 12] +=
MBBuffer[MBx][MBy][i][16*(blkId[j] - 1) + 12] | | +| } | | +| } else if (MBHPMode == 1) { | | +| blkId[ ] = {4,5,6,7,8,9,10,11,12,13,14,15} | | +| for (j = 0; j < 12; j++) { | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 1] +=
MBBuffer[MBx][MBy][i][16*(blkId[j] - 4) + 1] | | + +| HPCoefficientPrediction() { | Reference | +|-----------------------------------------------|-----------| +| MBBuffer[MBx][MBy][i][16*blkId[j] + 2] += | | +| MBBuffer[MBx][MBy][i][16*(blkId[j] - 4) + 2] | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 3] += | | +| MBBuffer[MBx][MBy][i][16*(blkId[j] - 4) + 3] | | +| } | | +| } | | +| } | | +| if (INTERNAL_CLR_FMT == YUV420) { | | +| for (i = 1; i <= 2; i++) { | | +| if (MBHPMode == 0) { | | +| blkId[ ] = {1,3} | | +| for (j = 0; j < 2; j++) { | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 4] += | | +| MBBuffer[MBx][MBy][i][16*(blkId[j] - 1) + 4] | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 8] += | | +| MBBuffer[MBx][MBy][i][16*(blkId[j] - 1) + 8] | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 12] += | | +| MBBuffer[MBx][MBy][i][16*(blkId[j] - 1) + 12] | | +| } | | +| } else if (MBHPMode == 1) { | | +| blkId[ ] = {2,3} | | +| for (j = 0; j < 2; j++) { | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 1] += | | +| MBBuffer[MBx][MBy][i][16*(blkId[j] - 2) + 1] | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 2] += | | +| MBBuffer[MBx][MBy][i][16*(blkId[j] - 2) + 2] | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 3] += | | +| MBBuffer[MBx][MBy][i][16*(blkId[j] - 2) + 3] | | +| } | | +| } | | +| } | | +| } else if (INTERNAL_CLR_FMT == YUV422) { | | +| for (i = 1; i <= 2; i++) { | | +| if (MBHPMode == 0) { | | +| blkId[ ] = {1,3,5,7} | | +| for (j = 0; j < 4; j++) { | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 4] += | | +| MBBuffer[MBx][MBy][i][16*(blkId[j] - 1) + 4] | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 8] += | | +| MBBuffer[MBx][MBy][i][16*(blkId[j] - 1) + 8] | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 12] += | | +| MBBuffer[MBx][MBy][i][16*(blkId[j] - 1) + 12] | | +| } | | +| } else if (MBHPMode == 1) { | | +| blkId[ ] = {2,4,6,3,5,7} | | +| for (j = 0; j < 6; j++) { | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 1] += | | +| MBBuffer[MBx][MBy][i][16*(blkId[j] - 2) + 1] | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 2] += | | +| MBBuffer[MBx][MBy][i][16*(blkId[j] - 2) + 2] | | +| MBBuffer[MBx][MBy][i][16*blkId[j] + 3] += | | +| MBBuffer[MBx][MBy][i][16*(blkId[j] - 2) + 3] | | +| } | | +| } | | +| } | | +| } | | +| } | | + +## 9.7 Derivation of quantization parameters + +### 9.7.1 Derivation of DC quantization parameters + +#### 9.7.1.1 Image plane level derivation of DC quantization parameters + +This process derives the array DCQuantParam[i] of image plane level DC quantization parameters for each colour component i, if these parameters are specified at the image plane level; otherwise, it does nothing, and it is expected that the tile-level derivation process will derive the array DCQuantParam[i], for each tile in the image plane. + +The image plane level derivation process of DC quantization parameters proceeds as specified in Table 137. + +**Table 137 – Pseudocode for function ImagePlaneDCQP( )** + +| ImagePlaneDCQP( ) { | Reference | +|------------------------------------------|------------------| +| if (DC_IMAGE_PLANE_UNIFORM_FLAG == TRUE) | | +| AssignDCQuantizationParameters( ) | 9.7.1.3 | +| } | | + +NOTE – If DC\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to FALSE, the quantization parameters are specified at tile level. + +#### 9.7.1.2 Tile level derivation of DC quantization parameters + +If these parameters are specified at the tile level, this process derives the array DCQuantParam[i] of tile-level DC quantization parameters for each colour component i. Otherwise, it does nothing and it is assumed that the image plane level derivation process has already derived the array DCQuantParam[i]. + +The tile-level derivation process of DC quantization parameters proceeds as specified in Table 138. + +**Table 138 – Pseudocode for function TileLevelDCQP( )** + +| TileLevelDCQP( ) { | Reference | +|-------------------------------------------|------------------| +| if (DC_IMAGE_PLANE_UNIFORM_FLAG == FALSE) | | +| AssignDCQuantizationParameters( ) | 9.7.1.3 | +| } | | + +NOTE – If DC\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to TRUE, quantization parameters were set at the image plane level. + +#### 9.7.1.3 Assignment of DC quantization parameters + +The assignment process of DC quantization parameters proceeds as specified in Table 139. + +**Table 139 – Pseudocode for function AssignDCQuantizationParameters( )** + +| AssignDCQuantizationParameters( ) { | Reference | +|--------------------------------------------|------------------| +| if (COMPONENT_MODE == UNIFORM) | | +| for (i = 0; i <= NumComponents-1; i++) | | +| DCQuantParam[i] = DC_QUANT | | +| else if (COMPONENT_MODE == SEPARATE) { | | +| DCQuantParam[0] = DC_QUANT_LUMA | | +| for (i = 1; i <= NumComponents-1; i++) | | +| DCQuantParam[i] = DC_QUANT_CHROMA | | +| } else if (COMPONENT_MODE == INDEPENDENT) | | +| for (i = 0; i <= NumComponents-1; i++) | | +| DCQuantParam[i] = DC_QUANT_CH[i] | | +| } | | + +## 9.7.2 Derivation of lowpass quantization parameters + +### 9.7.2.1 Image plane level derivation of lowpass quantization parameters + +This process derives the values LPQuantParam[i][j] of image plane level LP quantization parameters, for each colour component i, and each allowable index j (for image plane level LP quantization parameters, j can only take the value 0). These values are derived if LP\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to TRUE, which indicates that these quantization parameters are specified at the image plane level; otherwise, it does nothing, and it is expected that the tile-level derivation process will derive the array LPQuantParam[i][j], for each tile in the image plane. + +The image plane level derivation process of LP quantization parameters proceeds as specified in Table 140. + +**Table 140 – Pseudocode for function ImagePlaneLPQP( )** + +| ImagePlaneLPQP( ) { | Reference | +|-----------------------------------|------------------| +| if (LP_IMAGE_PLANE_UNIFORM_FLAG) | | +| AssignLPQuantizationParameters( ) | 9.7.2.3 | +| } | | + +NOTE 1 – When LP\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to TRUE, NumLPQPs is always equal to 1. + +NOTE 2 – If LP\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to FALSE, quantization parameters are set at the tile level. + +### 9.7.2.2 Tile level derivation of lowpass quantization parameters + +This process derives the values LPQuantParam[i][j] of tile-level LP quantization parameters, for each colour component i, and each allowable index j (ranging from 0 to NumLPQPs–1). These values are derived if these quantization parameters are specified at the tile level; otherwise, it does nothing, and the image plane level derivation process derived the array LPQuantParam[i][j], used for each tile in the current image plane. + +The tile-level derivation process of LP quantization parameters proceeds as specified in Table 141. + +**Table 141 – Pseudocode for function TileLevelLPQP( )** + +| TileLevelLPQP( ) { | Reference | +|-----------------------------------------------------------------------------|------------------| +| if ((LP_IMAGE_PLANE_UNIFORM_FLAG != TRUE) &&
(USE_DC_QP_FLAG == TRUE)) { | | +| NumLPQPs = 1 | | +| for (i = 0; i <= NumComponents–1; i++) | | +| LPQuantParam[i][0] = DCQuantParam[i] | | +| } else if (LP_IMAGE_PLANE_UNIFORM_FLAG != TRUE) | | +| AssignLPQuantizationParameters( ) | 9.7.2.3 | +| } | | + +NOTE – When LP\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to TRUE, nothing is done in this function, because quantization parameters were set at image plane level. + +9.7.2.3 Assignment of lowpass quantization parameters + +The assignment process of LP quantization parameters proceeds as specified in Table 142. + +Table 142 – Pseudocode for function AssignLPQuantizationParameters( ) + +| AssignLPQuantizationParameters( ) { | Reference | +|-------------------------------------------|-----------| +| for (j = 0; j < NumLPQPs; j++) { | | +| if (COMPONENT_MODE == UNIFORM) | | +| for (i = 0; i <= NumComponents-1; i++) | | +| LPQuantParam[i][j] = LP_QUANT[j] | | +| else if (COMPONENT_MODE == SEPARATE) { | | +| LPQuantParam[0][j] = LP_QUANT_LUMA[j] | | +| for (i = 1; i <= NumComponents-1; i++) | | +| LPQuantParam[i][j] = LP_QUANT_CHROMA[j] | | +| } else if (COMPONENT_MODE == INDEPENDENT) | | +| for (i = 0; i <= NumComponents-1; i++) | | +| LPQuantParam[i][j] = LP_QUANT_CH[i][j] | | +| } | | +| } | | + +9.7.3 Derivation of highpass quantization parameters + +9.7.3.1 Image plane level derivation of highpass quantization parameters + +This process derives the values HPQuantParam[i][j] of image plane level HP quantization parameters, for each colour component i, and each allowable index j. These values are derived if these quantization parameters are specified at the image plane level; otherwise, it does nothing, and it is expected that the tile-level derivation process will derive the array HPQuantParam[i][j], for each tile in the image plane. + +The image plane level derivation process of HP quantization parameters proceeds as specified in Table 143. + +Table 143 – Pseudocode for function ImagePlaneHPQP( ) + +| ImagePlaneHPQP( ) { | Reference | +|-----------------------------------|-----------| +| if (HP_IMAGE_PLANE_UNIFORM_FLAG) | | +| AssignHPQuantizationParameters( ) | 9.7.3.3 | +| } | | + +NOTE 1 – When HP\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to TRUE, NumHPQPs is always equal to 1. +NOTE 2 – When HP\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to FALSE, quantization parameters are set at the tile level. + +9.7.3.2 Tile level derivation of highpass quantization parameters + +This process derives the values HPQuantParam[i][j] of tile-level HP quantization parameters, for each colour component i, and each allowable index j (ranging from 0 to NumHPQPs-1). These values are derived if these quantization parameters are specified at the tile level; otherwise, this process has no effect, and it is expected that the image plane level derivation process derived the array HPQuantParam[i][j], used for each tile in the current image plane. + +The tile-level derivation process of HP quantization parameters proceeds as specified in Table 144. + +**Table 144 – Pseudocode for function TileLevelHPQP()** + +| TileLevelHPQP() { | Reference | +|-----------------------------------------------------------------------------|------------------| +| if ((HP_IMAGE_PLANE_UNIFORM_FLAG != TRUE) &&
(USE_LP_QP_FLAG == TRUE)) { | | +| NumHPQPs = NumLPQPs | | +| for (i = 0; i <= NumComponents-1; i++) | | +| for (j = 0; j <= NumLPQPs; j++) | | +| HPQuantParam[i][j] = LPQuantParam[i][j] | | +| } else if (HP_IMAGE_PLANE_UNIFORM_FLAG != TRUE) | | +| AssignHPQuantizationParameters() | 9.7.3.3 | +| } | | + +NOTE – When HP\_IMAGE\_PLANE\_UNIFORM\_FLAG is equal to TRUE, nothing is done in this function, because quantization parameters were set at image plane level. + +### 9.7.3.3 Assignment of highpass quantization parameters + +The assignment process of HP quantization parameters proceeds as specified in Table 145. + +**Table 145 – Pseudocode for function AssignHPQuantizationParameters()** + +| AssignHPQuantizationParameters() { | Reference | +|-------------------------------------------|------------------| +| for (j = 0; j < NumHPQPs; j++) { | | +| if (COMPONENT_MODE == UNIFORM) | | +| for (i = 0; i <= NumComponents-1; i++) | | +| HPQuantParam[i][j] = HP_QUANT[j] | | +| else if (COMPONENT_MODE == SEPARATE) { | | +| HPQuantParam[0][j] = HP_QUANT_LUMA[j] | | +| for (i = 1; i <= NumComponents-1; i++) | | +| HPQuantParam[i][j] = HP_QUANT_CHROMA[j] | | +| } else if (COMPONENT_MODE == INDEPENDENT) | | +| for (i = 0; i <= NumComponents-1; i++) | | +| HPQuantParam[i][j] = HP_QUANT_CH[i][j] | | +| } | | +| } | | + +## 9.8 Dequantization + +### 9.8.1 Dequantization of DC coefficients + +This process is applied for the DC coefficients of a macroblock, for all colour components. + +The input to this process is the array DCQuantParam[i] of DC quantization parameters for each colour component i; the array MbDCLP[MBx][MBy][i][0] of DC transform coefficients for each colour component i of the current macroblock; and the variables MBx and MBy which identify the current macroblock in the image. + +This process uses the local variable array iQuantScalingFactor[i], holding the scaling factor, for each colour component i. + +The output of this process is an array of scaled DC transform coefficients MbDCLP[MBx][MBy][i][0], for each colour component i. + +The dequantization process for DC coefficients proceeds as specified in Table 146. + +**Table 146 – Pseudocode for function DequantizeDCCoefficients( )** + +| DequantizeDCCoefficients( ) { | Reference | +|-----------------------------------------------------------------------------|------------------| +| for (i = 0; i < NumComponents; i++) { | | +| if (i == 0) | | +| iQuantScalingFactor[i] = QuantMap(DCQuantParam[i], 1) | 9.8.4 | +| else | | +| iQuantScalingFactor[i] = QuantMap(DCQuantParam[i], 0) | 9.8.4 | +| MbDCLP[MBx][MBy][i][0] =
MbDCLP[MBx][MBy][i][0] * iQuantScalingFactor[i] | | +| } | | +| } | | + +## 9.8.2 Dequantization of lowpass coefficients + +This process is applied for the LP coefficients of an entire macroblock, for all colour components. + +Inputs to this process are the values LPQuantParam[i][j] of LP quantization parameters, for each colour component i and index j; the quantization parameter index MBQPIndexLP[MBx][MBy]; the array MbDCLP[MBx][MBy][i][j] of LP transform coefficients, with i representing the colour component, and j referencing the LP transform coefficients, indexed in raster scan order. + +The output of this process is an array of scaled LP transform coefficients MbDCLP[MBx][MBy][i][j], for each colour component i and index j ranging from 1 to 15, referencing the respective LP transform coefficient. + +The dequantization process for LP coefficients proceeds as specified in Table 147. + +**Table 147 – Pseudocode for function DequantizeLPCoefficients( )** + +| DequantizeLPCoefficients( ) { | Reference | +|-----------------------------------------------------------------------------|------------------| +| for (i = 0; i < NumComponents; i++) { | | +| k = MBQPIndexLP[MBx][MBy] | | +| valueQP[i] = LPQuantParam[i][k] | | +| if (i == 0) | | +| iQuantScalingFactor[i] = QuantMap(valueQP[i], 1) | 9.8.4 | +| else | | +| iQuantScalingFactor[i] = QuantMap(valueQP[i], 0) | 9.8.4 | +| if (i == 0) /* Luma Component */ | | +| for (j = 1; j <= 15; j++) | | +| MbDCLP[MBx][MBy][i][j] =
MbDCLP[MBx][MBy][i][j] * iQuantScalingFactor[i] | | +| else if ((INTERNAL_CLR_FMT != YUV422) &&
(INTERNAL_CLR_FMT != YUV420)) | | +| for (j = 1; j <= 15; j++) | | +| MbDCLP[MBx][MBy][i][j] =
MbDCLP[MBx][MBy][i][j] * iQuantScalingFactor[i] | | +| else if (INTERNAL_CLR_FMT == YUV422) | | +| for (j = 1; j <= 7; j++) | | +| MbDCLP[MBx][MBy][i][j] =
MbDCLP[MBx][MBy][i][j] * iQuantScalingFactor[i] | | +| else /* if (INTERNAL_CLR_FMT == YUV420) */ | | +| for (j = 1; j <= 3; j++) | | +| MbDCLP[MBx][MBy][i][j] =
MbDCLP[MBx][MBy][i][j] * iQuantScalingFactor[i] | | +| } | | +| } | | + +## 9.8.3 Dequantization of highpass coefficients + +This process is applied for the HP coefficients of an entire macroblock, for all colour components. + +Inputs to this process are the values HPQuantParam[i][j] of HP quantization parameters, for each colour component i and index j; the quantization parameter index MBQPIndexHP[MBx][MBy]; the array MBBuffer[MBx][MBy][i][j] of HP transform coefficients, where i and j are indices, with i representing the colour component, and j ranging from 1 to 255. + +The output of this process is an array of scaled HP transform coefficients `MBBuffer[MBx][MBy][i][j]`, for each colour component `i` and index `j` ranging from 1 to 255, referencing the respective HP transform coefficient. + +The dequantization process for HP coefficients proceeds as specified in Table 148. + +**Table 148 – Pseudocode for function DequantizeHPCoefficients( )** + +| DequantizeHPCoefficients( ) { | Reference | +|--------------------------------------------------|------------------| +| for (i = 0; i < NumComponents; i++) { | | +| k = MBQPIndexHP[MBx][MBy] | | +| valueQP[i] = HPQuantParam[i][k] | | +| iQuantScalingFactor[i] = QuantMap(valueQP[i], 1) | 9.8.4 | +| if (i == 0) /* Luma Component */ | | +| for (blkIndex = 0; blkIndex <= 15; blkIndex++) | | +| for (j = 1; j <= 15; j++) | | +| MBBuffer[MBx][MBy][i][16*blkIndex + j] = | | +| MBBuffer[MBx][MBy][i][16*blkIndex + j] * | | +| iQuantScalingFactor[i] | | +| else if ((INTERNAL_CLR_FMT != YUV422) && | | +| (INTERNAL_CLR_FMT != YUV420)) | | +| for (blkIndex = 0; blkIndex <= 15; blkIndex++) | | +| for (j = 1; j <= 15; j++) | | +| MBBuffer[MBx][MBy][i][16*blkIndex + j] = | | +| MBBuffer[MBx][MBy][i][16*blkIndex + j] * | | +| iQuantScalingFactor[i] | | +| else if (INTERNAL_CLR_FMT == YUV422) | | +| for (blkIndex = 0; blkIndex <= 7; blkIndex++) | | +| for (j = 1; j <= 15; j++) | | +| MBBuffer[MBx][MBy][i][16*blkIndex + j] = | | +| MBBuffer[MBx][MBy][i][16*blkIndex + j] * | | +| iQuantScalingFactor[i] | | +| else /* if (INTERNAL_CLR_FMT == YUV420) */ | | +| for (blkIndex = 0; blkIndex <= 3; blkIndex++) | | +| for (j = 1; j <= 15; j++) | | +| MBBuffer[MBx][MBy][i][16*blkIndex + j] = | | +| MBBuffer[MBx][MBy][i][16*blkIndex + j] * | | +| iQuantScalingFactor[i] | | +| } | | +| } | | + +#### 9.8.4 QuantMap( ) + +The function `QuantMap` is used above to compute the scaling parameters based on the parsed syntax elements `QP`. The pseudocode for this function is specified in Table 149. + +**Table 149 – Pseudocode for function QuantMap( )** + +| QuantMap(iQP, iScaledShift) { | Reference | +|------------------------------------------------------|------------------| +| if (0 == iQP) | | +| iQuantScalingFactorResult = 1 | | +| else if (!SCALED_FLAG) { | | +| iNotScaledShift = -2 | | +| if (iQP < 32) { | | +| iMan = (iQP + 3) >> 2 | | +| iExp = 0 | | +| } else if (iQP < 48) { | | +| iMan = (16 + (iQP % 16) + 1) >> 1 | | +| iExp = (iQP >> 4) + iNotScaledShift | | +| } else { | | +| iMan = 16 + (iQP % 16) | | +| iExp = (iQP >> 4) - 1 + iNotScaledShift | | +| } | | +| iQuantScalingFactorResult = iMan << iExp | | +| } else /* SCALED_FLAG is TRUE, but not (0 == iQP) */ | | + +| QuantMap(iQP, iScaledShift) { | Reference | +|------------------------------------------|-----------| +| if (iQP < 16) { | | +| iMan = iQP | | +| iExp = iScaledShift | | +| } else { | | +| iMan = 16 + (iQP % 16) | | +| iExp = ((iQP >> 4) - 1) + iScaledShift | | +| } | | +| iQuantScalingFactorResult = iMan << iExp | | +| } | | +| return iQuantScalingFactorResult | | +| } | | + +NOTE – The input parameter iScaledShift takes the value of either 0 or 1, dependent on the component and band. When SCALED\_FLAG is equal to TRUE, the quantization scaling factor value can be modified by a power of 2. See the Note to 9.9.2. + +## 9.9 Sample reconstruction + +### 9.9.1 Overview + +Inputs to this process are the values MbDCLP[MBx][MBy][i][j] and MBBuffer[MBx][MBy][i][j] for the entire image plane, and the syntax element OVERLAP\_MODE. + +Outputs of this process are the decoded samples for the image plane. + +The sample reconstruction process proceeds as specified in Table 150. + +**Table 150 – Pseudocode for function SampleReconstruction()** + +| SampleReconstruction() { | Reference | +|-------------------------------------|-----------| +| FirstLevelInverseTransform() | 9.9.2 | +| if (OVERLAP_MODE == 2) | | +| FirstLevelOverlapFiltering() | 9.9.3 | +| SecondLevelCoefficientCombination() | 9.9.4 | +| SecondLevelInverseTransform() | 9.9.5 | +| if (OVERLAP_MODE != 0) | | +| SecondLevelOverlapFiltering() | 9.9.6 | +| } | | + +NOTE – Because the first level overlap filtering process in general involves interaction with adjacent macroblocks, the first level transform process must be complete for these adjacent macroblocks, prior to the overlap filtering process being invoked. The precedence of this relationship also holds between the second level processes: the second level's transform process must be complete for the adjacent macroblocks prior to the second level overlap filtering process. + +### 9.9.2 First level inverse transform + +Inputs to this process are the values MbDCLP[MBx][MBy][i][j] for the entire colour component. + +Outputs to this process are the modified values MbDCLP[MBx][MBy][i][j] for the current macroblock. + +The first level inverse transform process is specified as specified in Table 151. + +**Table 151 – Pseudocode for function FirstLevelInverseTransform()** + +| FirstLevelInverseTransform() { | Reference | +|------------------------------------------------------------------|------------------| +| for (i = 0; i < NumComponents; i++) | | +| for (MBy = 0; MBy < MBHeight; MBy++) | | +| for (MBx = 0; MBx < MBWidth; MBx++) | | +| if (i == 0) ((INTERNAL_CLR_FMT != YUV420) && | | +| (INTERNAL_CLR_FMT != YUV422)) { | | +| ICT4x4(MbDCLP[MBx][MBy][i][ ]) | 9.9.7.1 | +| if ((i > 0) && SCALED_FLAG) | | +| for (j = 0; j <= 15; j++) | | +| MbDCLP[MBx][MBy][i][j] = 2 * MbDCLP[MBx][MBy][i][j] | | +| } else if (INTERNAL_CLR_FMT == YUV420) { | | +| T2x2h(MbDCLP[MBx][MBy][i][ ], 0) | 9.9.7.2 | +| arrayLocal[ ] = {MbDCLP[MBx][MBy][i][1], MbDCLP[MBx][MBy][i][2]} | | +| InvPermute2pt(arrayLocal[ ]) | 9.9.7.6 | +| MbDCLP[MBx][MBy][i][1] = arrayLocal[0] | | +| MbDCLP[MBx][MBy][i][2] = arrayLocal[1] | | +| if ((i > 0) && SCALED_FLAG) | | +| for (j = 0; j <= 3; j++) | | +| MbDCLP[MBx][MBy][i][j] = 2 * MbDCLP[MBx][MBy][i][j] | | +| } else if (INTERNAL_CLR_FMT == YUV422) { | | +| arrayLocal[ ] = {MbDCLP[MBx][MBy][i][0], MbDCLP[MBx][MBy][i][4]} | | +| T2pt(arrayLocal[ ]) | 9.9.7.7 | +| MbDCLP[MBx][MBy][i][0] = arrayLocal[0] | | +| MbDCLP[MBx][MBy][i][4] = arrayLocal[1] | | +| T2x2h(MbDCLP[MBx][MBy][i][ ], 0) | 9.9.7.2 | +| arrayLocal[ ] = {MbDCLP[MBx][MBy][i][1], MbDCLP[MBx][MBy][i][2]} | | +| InvPermute2pt(arrayLocal[ ]) | 9.9.7.6 | +| MbDCLP[MBx][MBy][i][1] = arrayLocal[0] | | +| MbDCLP[MBx][MBy][i][2] = arrayLocal[1] | | +| arrayLocal[ ] = {MbDCLP[MBx][MBy][i][4], MbDCLP[MBx][MBy][i][6], | | +| MbDCLP[MBx][MBy][i][5], MbDCLP[MBx][MBy][i][7]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| MbDCLP[MBx][MBy][i][4] = arrayLocal[0] | | +| MbDCLP[MBx][MBy][i][6] = arrayLocal[1] | | +| MbDCLP[MBx][MBy][i][5] = arrayLocal[2] | | +| MbDCLP[MBx][MBy][i][7] = arrayLocal[3] | | +| arrayLocal[ ] = {MbDCLP[MBx][MBy][i][5], MbDCLP[MBx][MBy][i][6]} | | +| InvPermute2pt(arrayLocal[ ]) | 9.9.7.6 | +| MbDCLP[MBx][MBy][i][5] = arrayLocal[0] | | +| MbDCLP[MBx][MBy][i][6] = arrayLocal[1] | | +| if ((i > 0) && SCALED_FLAG) | | +| for (j = 0; j <= 7; j++) | | +| MbDCLP[MBx][MBy][i][j] = 2 * MbDCLP[MBx][MBy][i][j] | | +| } | | +| } | | +| } | | + +NOTE – The purpose of the multiplication by 2 for chroma components, in circumstances where scaling is involved, is to re-normalize the chroma with respect to the Y component. Due to possible conversion from RGB to YUV during encoding, the U and V components may have a numerical range that has increased by one bit. If SCALED\_FLAG is equal to TRUE, the dynamic range of the (DC and LP) U and V component values could potentially grow beyond 16 bits, due to the numerical range expansion associated with the two levels of transform on the encode side (for the DC and LP coefficients). Therefore, the quantization parameter for these chroma components is set to half the value used for luma components. The coefficients are scaled by this factor of two at the end of the first level transform process. + +## 9.9.3 First level overlap filtering + +### 9.9.3.1 Overview + +NOTE – The process specification in this subclause formalizes the geometric nature of the overlap filtering process. The various cases are described in the following. + +- interior: At every point where four 4×4 blocks meet in a corner, the 4×4 overlap filter process is applied to the 4×4 block straddling these four blocks evenly (i.e., overlapping with a 2×2 corner of each block). When HARD\_TILING\_FLAG is equal to FALSE, the 4×4 overlap filter process is applied across tile boundaries as well. +- top and bottom two rows: Along both the top two sample rows and the bottom two sample rows, a 4-point overlap filter process is applied evenly across adjacent block boundaries (overlapping with a 1×2 strip of each block). When HARD\_TILING\_FLAG is equal to TRUE, the 4-point overlap filter process is applied across the top 2 rows and bottom 2 rows of tiles as well. +- rightmost and leftmost two columns: Along both the leftmost two sample columns and the rightmost two sample columns, a 4-point overlap filter process is applied evenly across adjacent block boundaries (overlapping with a 2×1 strip of each block). When HARD\_TILING\_FLAG is equal to TRUE, the 4-point overlap filter process is applied across the top 2 columns and bottom 2 columns of tiles as well. +- four corners: Over the corner 2×2 blocks in the top-left, top-right, bottom-left and bottom-right, a 4-point overlap filter process is applied in a raster scan order (top-left, top-right, bottom-left, then bottom-right). When HARD\_TILING\_FLAG is equal to TRUE, the 4-point overlap filter process is applied to the four corners of each tile as well. + +Additionally, when INTERNAL\_CLR\_FMT is equal to either YUV422 or YUV420, alternate processes are considered for the chroma components for each of the above cases. These cases are described in the following. + +- chroma interior: The 2×2 overlap filter process is applied to the 2×2 block straddling interior block boundaries. When HARD\_TILING\_FLAG is equal to FALSE, the 2×2 overlap filter process is applied across tile boundaries as well. +- chroma top and bottom rows: Along both the top sample row and the bottom sample row, a 2-point overlap filter process is applied evenly across adjacent block boundaries. When HARD\_TILING\_FLAG is equal to TRUE, the 2-point overlap filter process is applied across the top row and bottom row of tiles as well. +- chroma rightmost and leftmost columns: Along both the leftmost sample column and the rightmost sample column, a 2-point overlap filter process is applied evenly across adjacent block boundaries. When HARD\_TILING\_FLAG is equal to TRUE, the 2-point overlap filter process is applied across the top column and bottom column of tiles as well. +- chroma four corners: Over the corner 1×1 blocks in the top-left, top-right, bottom-left and bottom-right, an adjacent coefficient residual process (specified in 9.9.3.3 and 9.9.3.4) is applied. When HARD\_TILING\_FLAG is equal to TRUE, the adjacent coefficient residual process is applied to the four corners of each tile as well. + +Inputs to this process are the values MbDCLP[MBx][MBy][i][j] for the entire image plane, and the values MBWidth and MBHeight. + +Outputs to this process are the modified values MbDCLP[MBx][MBy][i][j] for the current macroblock. + +The first level overlap filtering process is specified in Table 152. + +**Table 152 – Pseudocode for function FirstLevelOverlapFiltering( )** + +| FirstLevelOverlapFiltering( ) { | Reference | +|--------------------------------------------------------------------------------|------------------| +| for (i = 0; i < NumComponents; i++) | | +| if ((i == 0) ((INTERNAL_CLR_FMT != YUV420) &&(INTERNAL_CLR_FMT != YUV422))) | | +| FirstLevelOverlapFilteringPrimary(i) | 9.9.3.2 | +| else if (INTERNAL_CLR_FMT == YUV422) | | +| FirstLevelOverlapFiltering422(i) | 9.9.3.3 | +| else if (INTERNAL_CLR_FMT == YUV420) | | +| FirstLevelOverlapFiltering420(i) | 9.9.3.4 | +| } | | + +### 9.9.3.2 FirstLevelOverlapFilteringPrimary( ) + +Pseudocode for the function FirstLevelOverlapFilteringPrimary( ) is specified in Table 153. + +**Table 153 – Pseudocode for function FirstLevelOverlapFilteringPrimary( )** + +| FirstLevelOverlapFilteringPrimary(i) { | Reference | +|----------------------------------------------------------------------------------------------------------|------------------| +| for (Ty = 0; Ty <= (NumTileRows - 1); Ty++) { | | +| for (Tx = 0; Tx <= (NumTileCols - 1); Tx++) { | | +| for (y = TopMBIndexOfTile[Ty]; y <= (TopMBIndexOfTile[Ty + 1] - 2); y++) | | +| for (x = LeftMBIndexOfTile[Tx]; x <= (LeftMBIndexOfTile[Tx + 1] - 2); x++) | | +| FirstLevelCallOverlapPostFilter4x4(i, x, y) | 9.9.3.5 | +| if ((Tx == 0) (HARD_TILING_FLAG == TRUE)) { /* Left edge */ | | +| x = LeftMBIndexOfTile[Tx] | | +| for (y = TopMBIndexOfTile[Ty]; y <= TopMBIndexOfTile[Ty + 1] - 2; y++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][8], MbDCLP[x][y][i][12],
MbDCLP[x][y+1][i][0], MbDCLP[x][y+1][i][4]} | | + +| FirstLevelOverlapFilteringPrimary(i) { | Reference | +|-------------------------------------------------------------------------------------------------------------|-----------| +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][8] = arrayLocal[0] | | +| MbDCLP[x][y][i][12] = arrayLocal[1] | | +| MbDCLP[x][y+1][i][0] = arrayLocal[2] | | +| MbDCLP[x][y+1][i][4] = arrayLocal[3] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][9], MbDCLP[x][y][i][13],
MbDCLP[x][y+1][i][1], MbDCLP[x][y+1][i][5]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][9] = arrayLocal[0] | | +| MbDCLP[x][y][i][13] = arrayLocal[1] | | +| MbDCLP[x][y+1][i][1] = arrayLocal[2] | | +| MbDCLP[x][y+1][i][5] = arrayLocal[3] | | +| } | | +| } | | +| if ((Ty == 0) (HARD_TILING_FLAG == TRUE)) { /* Top edge */ | | +| y = TopMBIndexOfTile[Ty] | | +| for (x = LeftMBIndexOfTile[Tx]; x <= LeftMBIndexOfTile[Tx + 1] - 2; x++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][2], MbDCLP[x][y][i][3],
MbDCLP[x+1][y][i][0], MbDCLP[x+1][y][i][1]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][2] = arrayLocal[0] | | +| MbDCLP[x][y][i][3] = arrayLocal[1] | | +| MbDCLP[x+1][y][i][0] = arrayLocal[2] | | +| MbDCLP[x+1][y][i][1] = arrayLocal[3] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][6], MbDCLP[x][y][i][7],
MbDCLP[x+1][y][i][4], MbDCLP[x+1][y][i][5]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][6] = arrayLocal[0] | | +| MbDCLP[x][y][i][7] = arrayLocal[1] | | +| MbDCLP[x+1][y][i][4] = arrayLocal[2] | | +| MbDCLP[x+1][y][i][5] = arrayLocal[3] | | +| } | | +| } | | +| if ((Tx == NumTileCols - 1) (HARD_TILING_FLAG == TRUE)) { /* Right edge */ | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| for (y = TopMBIndexOfTile[Ty]; y <= TopMBIndexOfTile[Ty + 1] - 2; y++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][10], MbDCLP[x][y][i][14],
MbDCLP[x][y+1][i][2], MbDCLP[x][y+1][i][6]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][10] = arrayLocal[0] | | +| MbDCLP[x][y][i][14] = arrayLocal[1] | | +| MbDCLP[x][y+1][i][2] = arrayLocal[2] | | +| MbDCLP[x][y+1][i][6] = arrayLocal[3] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][11], MbDCLP[x][y][i][15],
MbDCLP[x][y+1][i][3], MbDCLP[x][y+1][i][7]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][11] = arrayLocal[0] | | +| MbDCLP[x][y][i][15] = arrayLocal[1] | | +| MbDCLP[x][y+1][i][3] = arrayLocal[2] | | +| MbDCLP[x][y+1][i][7] = arrayLocal[3] | | +| } | | +| } | | +| if ((Ty == NumTileRows - 1) (HARD_TILING_FLAG == TRUE)) { /* Bottom edge */ | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| for (x = LeftMBIndexOfTile[Tx]; x <= LeftMBIndexOfTile[Tx + 1] - 2; x++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][10], MbDCLP[x][y][i][11],
MbDCLP[x+1][y][i][8], MbDCLP[x+1][y][i][9]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][10] = arrayLocal[0] | | +| MbDCLP[x][y][i][11] = arrayLocal[1] | | +| MbDCLP[x+1][y][i][8] = arrayLocal[2] | | +| MbDCLP[x+1][y][i][9] = arrayLocal[3] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][14], MbDCLP[x][y][i][15],
MbDCLP[x+1][y][i][12], MbDCLP[x+1][y][i][13]} | | + +| FirstLevelOverlapFilteringPrimary(i) { | Reference | +|------------------------------------------------------------------------------------------------------------------------|-----------| +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][14] = arrayLocal[0] | | +| MbDCLP[x][y][i][15] = arrayLocal[1] | | +| MbDCLP[x+1][y][i][12] = arrayLocal[2] | | +| MbDCLP[x+1][y][i][13] = arrayLocal[3] | | +| } | | +| } | | +| if (((Tx == 0) && (Ty == 0)) (HARD_TILING_FLAG == TRUE)) { /* Top left corner */ | | +| x = LeftMBIndexOfTile[Tx] | | +| y = TopMBIndexOfTile[Ty] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][0], MbDCLP[x][y][i][1],
MbDCLP[x][y][i][4], MbDCLP[x][y][i][5]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][0] = arrayLocal[0] | | +| MbDCLP[x][y][i][1] = arrayLocal[1] | | +| MbDCLP[x][y][i][4] = arrayLocal[2] | | +| MbDCLP[x][y][i][5] = arrayLocal[3] | | +| } | | +| if (((Tx == NumTileCols - 1) && (Ty == 0)) (HARD_TILING_FLAG == TRUE)) { | | +| /* Top right corner */ | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| y = TopMBIndexOfTile[Ty] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][2], MbDCLP[x][y][i][3],
MbDCLP[x][y][i][6], MbDCLP[x][y][i][7]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][2] = arrayLocal[0] | | +| MbDCLP[x][y][i][3] = arrayLocal[1] | | +| MbDCLP[x][y][i][6] = arrayLocal[2] | | +| MbDCLP[x][y][i][7] = arrayLocal[3] | | +| } | | +| if (((Tx == 0) && (Ty == NumTileRows - 1)) (HARD_TILING_FLAG == TRUE)) { | | +| /* Bottom left corner */ | | +| x = LeftMBIndexOfTile[Tx] | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| arrayLocal[ ] = {MbDCLP[x][y][i][8], MbDCLP[x][y][i][9],
MbDCLP[x][y][i][12], MbDCLP[x][y][i][13]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][8] = arrayLocal[0] | | +| MbDCLP[x][y][i][9] = arrayLocal[1] | | +| MbDCLP[x][y][i][12] = arrayLocal[2] | | +| MbDCLP[x][y][i][13] = arrayLocal[3] | | +| } | | +| if (((Tx == NumTileCols - 1) && (Ty == NumTileRows - 1))
(HARD_TILING_FLAG == TRUE)) { /* Bottom right corner */ | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| arrayLocal[ ] = {MbDCLP[x][y][i][10], MbDCLP[x][y][i][11],
MbDCLP[x][y][i][14], MbDCLP[x][y][i][15]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][10] = arrayLocal[0] | | +| MbDCLP[x][y][i][11] = arrayLocal[1] | | +| MbDCLP[x][y][i][14] = arrayLocal[2] | | +| MbDCLP[x][y][i][15] = arrayLocal[3] | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx != NumTileCols - 1)) { | | +| /* Right across for soft tiles */ | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| for (y = TopMBIndexOfTile[Ty]; y <= (TopMBIndexOfTile[Ty + 1] - 2); y++) | | +| FirstLevelCallOverlapPostFilter4x4(i, x, y) | 9.9.3.5 | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Ty != NumTileRows - 1)) { | | +| /* Bottom across for soft tiles */ | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| for (x = LeftMBIndexOfTile[Tx]; x <= (LeftMBIndexOfTile[Tx + 1] - 2); x++) | | +| FirstLevelCallOverlapPostFilter4x4(i, x, y) | 9.9.3.5 | + +| FirstLevelOverlapFilteringPrimary(i) { | Reference | +|-----------------------------------------------------------------------------------------------------------------------------|-----------| +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx != NumTileCols - 1) && (Ty != NumTileRows - 1)) { /* Bottom across for soft tiles */ | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| FirstLevelCallOverlapPostFilter4x4(i, x, y) | 9.9.3.5 | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx == 0) && (Ty != NumTileRows - 1)) { | | +| /* Left edge for soft tiles */ | | +| x = LeftMBIndexOfTile[Tx] | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| arrayLocal[ ] = {MbDCLP[x][y][i][8], MbDCLP[x][y][i][12], MbDCLP[x][y+1][i][0], MbDCLP[x][y+1][i][4]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][8] = arrayLocal[0] | | +| MbDCLP[x][y][i][12] = arrayLocal[1] | | +| MbDCLP[x][y+1][i][0] = arrayLocal[2] | | +| MbDCLP[x][y+1][i][4] = arrayLocal[3] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][9], MbDCLP[x][y][i][13], MbDCLP[x][y+1][i][1], MbDCLP[x][y+1][i][5]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][9] = arrayLocal[0] | | +| MbDCLP[x][y][i][13] = arrayLocal[1] | | +| MbDCLP[x][y+1][i][1] = arrayLocal[2] | | +| MbDCLP[x][y+1][i][5] = arrayLocal[3] | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx != NumTileCols - 1) && (Ty == 0)) { | | +| /* Top edge for soft tiles */ | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| y = TopMBIndexOfTile[Ty] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][2], MbDCLP[x][y][i][3], MbDCLP[x+1][y][i][0], MbDCLP[x+1][y][i][1]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][2] = arrayLocal[0] | | +| MbDCLP[x][y][i][3] = arrayLocal[1] | | +| MbDCLP[x+1][y][i][0] = arrayLocal[2] | | +| MbDCLP[x+1][y][i][1] = arrayLocal[3] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][6], MbDCLP[x][y][i][7], MbDCLP[x+1][y][i][4], MbDCLP[x+1][y][i][5]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][6] = arrayLocal[0] | | +| MbDCLP[x][y][i][7] = arrayLocal[1] | | +| MbDCLP[x+1][y][i][4] = arrayLocal[2] | | +| MbDCLP[x+1][y][i][5] = arrayLocal[3] | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx == NumTileCols - 1) && (Ty != NumTileRows - 1)) { /* Right edge for soft tiles */ | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| arrayLocal[ ] = {MbDCLP[x][y][i][10], MbDCLP[x][y][i][14], MbDCLP[x][y+1][i][2], MbDCLP[x][y+1][i][6]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][10] = arrayLocal[0] | | +| MbDCLP[x][y][i][14] = arrayLocal[1] | | +| MbDCLP[x][y+1][i][2] = arrayLocal[2] | | +| MbDCLP[x][y+1][i][6] = arrayLocal[3] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][11], MbDCLP[x][y][i][15], MbDCLP[x][y+1][i][4], MbDCLP[x][y+1][i][7]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][11] = arrayLocal[0] | | +| MbDCLP[x][y][i][15] = arrayLocal[1] | | +| MbDCLP[x][y+1][i][4] = arrayLocal[2] | | +| MbDCLP[x][y+1][i][7] = arrayLocal[3] | | +| } | | + +| FirstLevelOverlapFilteringPrimary(i) { | Reference | +|---------------------------------------------------------------------------------------------------------------------------|-----------| +| if ((HARD_TILING_FLAG == FALSE) && (Tx != NumTileCols - 1) && (Ty == NumTileRows - 1)) { /* Bottom edge for soft tiles */ | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| arrayLocal[ ] = {MbDCLP[x][y][i][10], MbDCLP[x][y][i][11], MbDCLP[x+1][y][i][8], MbDCLP[x+1][y][i][9]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][10] = arrayLocal[0] | | +| MbDCLP[x][y][i][11] = arrayLocal[1] | | +| MbDCLP[x+1][y][i][8] = arrayLocal[2] | | +| MbDCLP[x+1][y][i][9] = arrayLocal[3] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][14], MbDCLP[x][y][i][15], MbDCLP[x+1][y][i][12], MbDCLP[x+1][y][i][13]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| MbDCLP[x][y][i][14] = arrayLocal[0] | | +| MbDCLP[x][y][i][15] = arrayLocal[1] | | +| MbDCLP[x+1][y][i][12] = arrayLocal[2] | | +| MbDCLP[x+1][y][i][13] = arrayLocal[3] | | +| } | | +| } | | +| } | | +| } | | + +### 9.9.3.3 FirstLevelOverlapFiltering422( ) + +Pseudocode for the function FirstLevelOverlapFiltering422( ) is specified in Table 154. + +**Table 154 – Pseudocode for function FirstLevelOverlapFiltering422( )** + +| FirstLevelOverlapFiltering422(i) { | Reference | +|-------------------------------------------------------------------------------------------------------------------------------------------------|-----------| +| for (Ty = 0; Ty <= (NumTileRows - 1); Ty++) { | | +| if ((Ty == 0) (HARD_TILING_FLAG == TRUE)) { /* Top edge */ | | +| /* OverlapPostFilter1 */ | | +| y = TopMBIndexOfTile[Ty] | | +| MbDCLP[LeftMBIndexOfTile[0]][y][i][0] -= MbDCLP[LeftMBIndexOfTile[0]][y][i][1] | | +| /* Upper left corner difference */ | | +| MbDCLP[LeftMBIndexOfTile[NumTileCols] - 1][y][i][1] -= MbDCLP[LeftMBIndexOfTile[NumTileCols] - 1][y][i][0] /* Upper right corner difference */ | | +| if (HARD_TILING_FLAG == TRUE) | | +| for (Tx = 1; Tx < (NumTileCols - 1); Tx++) { | | +| MbDCLP[LeftMBIndexOfTile[Tx]][y][i][0] -= MbDCLP[LeftMBIndexOfTile[Tx]][y][i][1] | | +| MbDCLP[LeftMBIndexOfTile[Tx] - 1][y][i][1] -= MbDCLP[LeftMBIndexOfTile[Tx] - 1][y][i][0] | | +| } | | +| } | | +| if ((Ty == NumTileRows - 1) (HARD_TILING_FLAG == TRUE)) { /* Bottom edge */ | | +| /* OverlapPostFilter1 */ | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| MbDCLP[LeftMBIndexOfTile[0]][y][i][6] -= MbDCLP[LeftMBIndexOfTile[0]][y][i][7] | | +| /* Bottom left corner difference */ | | +| MbDCLP[LeftMBIndexOfTile[NumTileCols] - 1][y][i][7] -= MbDCLP[LeftMBIndexOfTile[NumTileCols] - 1][y][i][6] /* Bottom right corner difference */ | | +| if (HARD_TILING_FLAG == TRUE) | | +| for (Tx = 1; Tx < (NumTileCols - 1); Tx++) { | | +| MbDCLP[LeftMBIndexOfTile[Tx]][y][i][6] -= MbDCLP[LeftMBIndexOfTile[Tx]][y][i][7] | | +| MbDCLP[LeftMBIndexOfTile[Tx] - 1][y][i][7] -= MbDCLP[LeftMBIndexOfTile[Tx] - 1][y][i][6] | | +| } | | +| } | | +| for (Tx = 0; Tx <= (NumTileCols - 1); Tx++) { | | +| for (y = TopMBIndexOfTile[Tx]; y <= (TopMBIndexOfTile[Tx + 1] - 1); y++) | | +| for (x = LeftMBIndexOfTile[Tx]; x <= (LeftMBIndexOfTile[Tx + 1] - 2); x++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][3], MbDCLP[x+1][y][i][2], MbDCLP[x][y][i][5], MbDCLP[x+1][y][i][4]} | | +| OverlapPostFilter2x2(arrayLocal[ ]) | 9.9.8.3 | +| MbDCLP[x][y][i][3] = arrayLocal[0] | | + +| FirstLevelOverlapFiltering422(i) { | Reference | +|--------------------------------------------------------------------------------|-----------| +| MbDCLP[x+1][y][i][2] = arrayLocal[1] | | +| MbDCLP[x][y][i][5] = arrayLocal[2] | | +| MbDCLP[x+1][y][i][4] = arrayLocal[3] | | +| if (y != (TopMBIndexOfTile[Ty + 1] - 1)) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][7], MbDCLP[x+1][y][i][6], | | +| MbDCLP[x][y+1][i][1], MbDCLP[x+1][y+1][i][0]} | | +| OverlapPostFilter2x2(arrayLocal[ ]) | 9.9.8.3 | +| MbDCLP[x][y][i][7] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][6] = arrayLocal[1] | | +| MbDCLP[x][y+1][i][1] = arrayLocal[2] | | +| MbDCLP[x+1][y+1][i][0] = arrayLocal[3] | | +| } | | +| } | | +| if ((Tx == 0) (HARD_TILING_FLAG == TRUE)) { /* Left edge */ | | +| x = LeftMBIndexOfTile[Tx] | | +| for (y = TopMBIndexOfTile[Ty]; y <= (TopMBIndexOfTile[Ty + 1] - 1); y++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][2], MbDCLP[x][y][i][4]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][2] = arrayLocal[0] | | +| MbDCLP[x][y][i][4] = arrayLocal[1] | | +| if (y != (TopMBIndexOfTile[Ty + 1] - 1)) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][6], MbDCLP[x][y+1][i][0]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][6] = arrayLocal[0] | | +| MbDCLP[x][y+1][i][0] = arrayLocal[1] | | +| } | | +| } | | +| } | | +| if ((Tx == NumTileCols - 1) (HARD_TILING_FLAG == TRUE)) { /* Right edge */ | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| for (y = TopMBIndexOfTile[Ty]; y <= (TopMBIndexOfTile[Ty + 1] - 1); y++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][3], MbDCLP[x][y][i][5]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][3] = arrayLocal[0] | | +| MbDCLP[x][y][i][5] = arrayLocal[1] | | +| if (y != (TopMBIndexOfTile[Ty + 1] - 1)) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][7], MbDCLP[x][y+1][i][1]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][7] = arrayLocal[0] | | +| MbDCLP[x][y+1][i][1] = arrayLocal[1] | | +| } | | +| } | | +| } | | +| if ((Ty == 0) (HARD_TILING_FLAG == TRUE)) { /* Top edge */ | | +| y = TopMBIndexOfTile[Ty] | | +| for (x = LeftMBIndexOfTile[Tx]; x <= (LeftMBIndexOfTile[Tx + 1] - 2); x++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][1], MbDCLP[x+1][y][i][0]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][1] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][0] = arrayLocal[1] | | +| } | | +| } | | +| if ((Ty == NumTileRows - 1) (HARD_TILING_FLAG == TRUE)) { /* Bottom edge */ | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| for (x = LeftMBIndexOfTile[Tx]; x <= (LeftMBIndexOfTile[Tx + 1] - 2); x++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][7], MbDCLP[x+1][y][i][6]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][7] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][6] = arrayLocal[1] | | +| } | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx != NumTileCols - 1)) { | | +| /* Right across for soft tiles */ | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | + +| FirstLevelOverlapFiltering422(i) { | Reference | +|-------------------------------------------------------------------------------------------------------------|------------------| +| for (y = TopMBIndexOfFile[Ty]; y <= (TopMBIndexOfFile[Ty + 1] - 2); y++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][3], MbDCLP[x+1][y][i][2],
MbDCLP[x][y][i][5], MbDCLP[x+1][y][i][4]} | | +| OverlapPostFilter2x2(arrayLocal[ ]) | 9.9.8.3 | +| MbDCLP[x][y][i][3] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][2] = arrayLocal[1] | | +| MbDCLP[x][y][i][5] = arrayLocal[2] | | +| MbDCLP[x+1][y][i][4] = arrayLocal[3] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][7], MbDCLP[x+1][y][i][6],
MbDCLP[x][y+1][i][1], MbDCLP[x+1][y+1][i][0]} | | +| OverlapPostFilter2x2(arrayLocal[ ]) | 9.9.8.3 | +| MbDCLP[x][y][i][7] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][6] = arrayLocal[1] | | +| MbDCLP[x][y+1][i][1] = arrayLocal[2] | | +| MbDCLP[x+1][y+1][i][0] = arrayLocal[3] | | +| } | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Ty != NumTileRows - 1)) { | | +| /* Bottom across for soft tiles */ | | +| y = TopMBIndexOfFile[Ty + 1] - 1 | | +| for (x = LeftMBIndexOfFile[Tx]; x <= (LeftMBIndexOfFile[Tx + 1] - 2); x++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][3], MbDCLP[x+1][y][i][2],
MbDCLP[x][y][i][5], MbDCLP[x+1][y][i][4]} | | +| OverlapPostFilter2x2(arrayLocal[ ]) | 9.9.8.3 | +| MbDCLP[x][y][i][3] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][2] = arrayLocal[1] | | +| MbDCLP[x][y][i][5] = arrayLocal[2] | | +| MbDCLP[x+1][y][i][4] = arrayLocal[3] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][7], MbDCLP[x+1][y][i][6],
MbDCLP[x][y+1][i][1], MbDCLP[x+1][y+1][i][0]} | | +| OverlapPostFilter2x2(arrayLocal[ ]) | 9.9.8.3 | +| MbDCLP[x][y][i][7] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][6] = arrayLocal[1] | | +| MbDCLP[x][y+1][i][1] = arrayLocal[2] | | +| MbDCLP[x+1][y+1][i][0] = arrayLocal[3] | | +| } | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx != NumTileCols - 1) &&
(Ty != NumTileRows - 1)) { | | +| x = LeftMBIndexOfFile[Tx + 1] - 1 | | +| y = TopMBIndexOfFile[Ty + 1] - 1 | | +| arrayLocal[ ] = {MbDCLP[x][y][i][3], MbDCLP[x+1][y][i][2],
MbDCLP[x][y][i][5], MbDCLP[x+1][y][i][4]} | | +| OverlapPostFilter2x2(arrayLocal[ ]) | 9.9.8.3 | +| MbDCLP[x][y][i][3] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][2] = arrayLocal[1] | | +| MbDCLP[x][y][i][5] = arrayLocal[2] | | +| MbDCLP[x+1][y][i][4] = arrayLocal[3] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][7], MbDCLP[x+1][y][i][6],
MbDCLP[x][y+1][i][1], MbDCLP[x+1][y+1][i][0]} | | +| OverlapPostFilter2x2(arrayLocal[ ]) | 9.9.8.3 | +| MbDCLP[x][y][i][7] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][6] = arrayLocal[1] | | +| MbDCLP[x][y+1][i][1] = arrayLocal[2] | | +| MbDCLP[x+1][y+1][i][0] = arrayLocal[3] | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx == 0) && (Ty != NumTileRows - 1)) { | | +| x = LeftMBIndexOfFile[Tx] | | +| y = TopMBIndexOfFile[Ty + 1] - 1 | | +| arrayLocal[ ] = {MbDCLP[x][y][i][2], MbDCLP[x][y][i][4]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][2] = arrayLocal[0] | | +| MbDCLP[x][y][i][4] = arrayLocal[1] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][6], MbDCLP[x][y+1][i][0]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | + +| FirstLevelOverlapFiltering422(i) { | Reference | +|------------------------------------------------------------------------------------------|-----------| +| MbDCLP[x][y][i][6] = arrayLocal[0] | | +| MbDCLP[x][y+1][i][0] = arrayLocal[1] | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx == NumTileCols - 1) && (Ty != NumTileRows - 1)) { | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| arrayLocal[ ] = {MbDCLP[x][y][i][3], MbDCLP[x][y][i][5]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][3] = arrayLocal[0] | | +| MbDCLP[x][y][i][5] = arrayLocal[1] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][7], MbDCLP[x][y+1][i][1]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][7] = arrayLocal[0] | | +| MbDCLP[x][y+1][i][1] = arrayLocal[1] | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx != NumTileCols - 1) && (Ty == 0)) { | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| y = TopMBIndexOfTile[Ty] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][1], MbDCLP[x+1][y][i][0]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][1] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][0] = arrayLocal[1] | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx != NumTileCols - 1) && (Ty == NumTileRows - 1)) { | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| arrayLocal[ ] = {MbDCLP[x][y][i][7], MbDCLP[x+1][y][i][6]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][7] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][6] = arrayLocal[1] | | +| } | | +| } | | +| if ((Ty == 0) (HARD_TILING_FLAG == TRUE)) { /*Top edge */ | | +| /* OverlapPostFilter1 */ | | +| y = TopMBIndexOfTile[Ty] | | +| MbDCLP[LeftMBIndexOfTile[0]][y][i][0] += MbDCLP[LeftMBIndexOfTile[0]][y][i][1] | | +| /* Upper left corner addition */ | | +| MbDCLP[LeftMBIndexOfTile[NumTileCols] - 1][y][i][1] += | | +| MbDCLP[LeftMBIndexOfTile[NumTileCols] - 1][y][i][0] /* Upper right corner addition */ | | +| if (HARD_TILING_FLAG == TRUE) | | +| for (Tx = 1; Tx < (NumTileCols - 1); Tx++) { | | +| MbDCLP[LeftMBIndexOfTile[Tx]][y][i][0] += MbDCLP[LeftMBIndexOfTile[Tx]][y][i][1] | | +| MbDCLP[LeftMBIndexOfTile[Tx] - 1][y][i][1] += | | +| MbDCLP[LeftMBIndexOfTile[Tx] - 1][y][i][0] | | +| } | | +| } | | +| if ((Ty == NumTileRows - 1) (HARD_TILING_FLAG == TRUE)) { /* Bottom edge */ | | +| /* OverlapPostFilter1 */ | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| MbDCLP[LeftMBIndexOfTile[0]][y][i][6] += MbDCLP[LeftMBIndexOfTile[0]][y][i][7] | | +| /* Bottom left corner addition */ | | +| MbDCLP[LeftMBIndexOfTile[NumTileCols] - 1][y][i][7] += | | +| MbDCLP[LeftMBIndexOfTile[NumTileCols] - 1][y][i][6] /* Bottom right corner addition */ | | +| if (HARD_TILING_FLAG == TRUE) | | +| for (Tx = 1; Tx < (NumTileCols - 1); Tx++) { | | +| MbDCLP[LeftMBIndexOfTile[Tx]][y][i][6] += MbDCLP[LeftMBIndexOfTile[Tx]][y][i][7] | | +| MbDCLP[LeftMBIndexOfTile[Tx] - 1][y][i][7] += | | +| MbDCLP[LeftMBIndexOfTile[Tx] - 1][y][i][6] | | +| } | | +| } | | +| } | | +| } | | + +### 9.9.3.4 FirstLevelOverlapFiltering420() + +Pseudocode for the function FirstLevelOverlapFiltering420() is specified in Table 155. + +**Table 155 – Pseudocode for function FirstLevelOverlapFiltering420()** + +| FirstLevelOverlapFiltering420(i) { | Reference | +|------------------------------------------------------------------------------------------|------------------| +| for (Ty = 0; Ty <= (NumTileRows - 1); Ty++) { | | +| if ((Ty == 0) (HARD_TILING_FLAG == TRUE)) { /* Top edge */ | | +| /* OverlapPostFilter1 */ | | +| y = TopMBIndexOfTile[Ty] | | +| MbDCLP[LeftMBIndexOfTile[0]][y][i][0] -= MbDCLP[LeftMBIndexOfTile[0]][y][i][1] | | +| /* Upper left corner difference */ | | +| MbDCLP[LeftMBIndexOfTile[NumTileCols - 1]][y][i][1] -= | | +| MbDCLP[LeftMBIndexOfTile[NumTileCols - 1]][y][i][0] /* Upper right corner difference */ | | +| if (HARD_TILING_FLAG == TRUE) | | +| for (Tx = 1; Tx < (NumTileCols - 1); Tx++) { | | +| MbDCLP[LeftMBIndexOfTile[Tx]][y][i][0] -= MbDCLP[LeftMBIndexOfTile[Tx]][y][i][1] | | +| MbDCLP[LeftMBIndexOfTile[Tx - 1]][y][i][1] -= | | +| MbDCLP[LeftMBIndexOfTile[Tx - 1]][y][i][0] | | +| } | | +| } | | +| if ((Ty == NumTileRows - 1) (HARD_TILING_FLAG == TRUE)) { /* Bottom edge */ | | +| /* OverlapPostFilter1 */ | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| MbDCLP[LeftMBIndexOfTile[0]][y][i][2] -= MbDCLP[LeftMBIndexOfTile[0]][y][i][3] | | +| /* Bottom left corner difference */ | | +| MbDCLP[LeftMBIndexOfTile[NumTileCols - 1]][y][i][3] -= | | +| MbDCLP[LeftMBIndexOfTile[NumTileCols - 1]][y][i][2] /* Bottom right corner difference */ | | +| if (HARD_TILING_FLAG == TRUE) | | +| for (Tx = 1; Tx < (NumTileCols - 1); Tx++) { | | +| MbDCLP[LeftMBIndexOfTile[Tx]][y][i][2] -= MbDCLP[LeftMBIndexOfTile[Tx]][y][i][3] | | +| MbDCLP[LeftMBIndexOfTile[Tx - 1]][y][i][3] -= | | +| MbDCLP[LeftMBIndexOfTile[Tx - 1]][y][i][2] | | +| } | | +| } | | +| for (Tx = 0; Tx <= (NumTileCols - 1); Tx++) { | | +| for (y = TopMBIndexOfTile[Tx]; y <= (TopMBIndexOfTile[Tx + 1] - 2); y++) | | +| for (x = LeftMBIndexOfTile[Tx]; x <= (LeftMBIndexOfTile[Tx + 1] - 2); x++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][3], MbDCLP[x+1][y][i][2], | | +| MbDCLP[x][y+1][i][1], MbDCLP[x+1][y+1][i][0]} | | +| OverlapPostFilter2x2(arrayLocal[ ]) | 9.9.8.3 | +| MbDCLP[x][y][i][3] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][2] = arrayLocal[1] | | +| MbDCLP[x][y+1][i][1] = arrayLocal[2] | | +| MbDCLP[x+1][y+1][i][0] = arrayLocal[3] | | +| } | | +| if ((Tx == 0) (HARD_TILING_FLAG == TRUE)) { /* Left edge */ | | +| x = LeftMBIndexOfTile[Tx] | | +| for (y = TopMBIndexOfTile[Ty]; y <= (TopMBIndexOfTile[Ty + 1] - 2); y++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][2], MbDCLP[x][y+1][i][0]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][2] = arrayLocal[0] | | +| MbDCLP[x][y+1][i][0] = arrayLocal[1] | | +| } | | +| } | | +| if ((Tx == NumTileCols - 1) (HARD_TILING_FLAG == TRUE)) { /* Right edge */ | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| for (y = TopMBIndexOfTile[Ty]; y <= (TopMBIndexOfTile[Ty + 1] - 2); y++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][3], MbDCLP[x][y+1][i][1]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][3] = arrayLocal[0] | | +| MbDCLP[x][y+1][i][1] = arrayLocal[1] | | +| } | | +| } | | +| } | | + +| FirstLevelOverlapFiltering420(i) { | Reference | +|--------------------------------------------------------------------------------|-----------| +| if ((Ty == 0) (HARD_TILING_FLAG == TRUE)) { /* Top edge */ | | +| y = TopMBIndexOfTile[Ty] | | +| for (x = LeftMBIndexOfTile[Tx]; x <= (LeftMBIndexOfTile[Tx + 1] - 2); x++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][1], MbDCLP[x+1][y][i][0]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][1] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][0] = arrayLocal[1] | | +| } | | +| } | | +| if ((Ty == NumTileRows - 1) (HARD_TILING_FLAG == TRUE)) { /* Bottom edge */ | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| for (x = LeftMBIndexOfTile[Tx]; x <= (LeftMBIndexOfTile[Tx + 1] - 2); x++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][3], MbDCLP[x+1][y][i][2]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][3] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][2] = arrayLocal[1] | | +| } | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx != NumTileCols - 1)) { | | +| /* Right across for soft tiles */ | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| for (y = TopMBIndexOfTile[Ty]; y <= (TopMBIndexOfTile[Ty + 1] - 2); y++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][3], MbDCLP[x+1][y][i][2], | | +| MbDCLP[x][y+1][i][1], MbDCLP[x+1][y+1][i][0]} | | +| OverlapPostFilter2x2(arrayLocal[ ]) | 9.9.8.3 | +| MbDCLP[x][y][i][3] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][2] = arrayLocal[1] | | +| MbDCLP[x][y+1][i][1] = arrayLocal[2] | | +| MbDCLP[x+1][y+1][i][0] = arrayLocal[3] | | +| } | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Ty != NumTileRows - 1)) { | | +| /* Bottom across for soft tiles */ | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| for (x = LeftMBIndexOfTile[Tx]; x <= (LeftMBIndexOfTile[Tx + 1] - 2); x++) { | | +| arrayLocal[ ] = {MbDCLP[x][y][i][3], MbDCLP[x+1][y][i][2], | | +| MbDCLP[x][y+1][i][1], MbDCLP[x+1][y+1][i][0]} | | +| OverlapPostFilter2x2(arrayLocal[ ]) | 9.9.8.3 | +| MbDCLP[x][y][i][3] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][2] = arrayLocal[1] | | +| MbDCLP[x][y+1][i][1] = arrayLocal[2] | | +| MbDCLP[x+1][y+1][i][0] = arrayLocal[3] | | +| } | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx != NumTileCols - 1) && | | +| (Ty != NumTileRows - 1)) { | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| arrayLocal[ ] = {MbDCLP[x][y][i][3], MbDCLP[x+1][y][i][2], | | +| MbDCLP[x][y+1][i][1], MbDCLP[x+1][y+1][i][0]} | | +| OverlapPostFilter2x2(arrayLocal[ ]) | 9.9.8.3 | +| MbDCLP[x][y][i][3] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][2] = arrayLocal[1] | | +| MbDCLP[x][y+1][i][1] = arrayLocal[2] | | +| MbDCLP[x+1][y+1][i][0] = arrayLocal[3] | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx == 0) && (Ty != NumTileRows - 1)) { | | +| x = LeftMBIndexOfTile[Tx] | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| arrayLocal[ ] = {MbDCLP[x][y][i][2], MbDCLP[x][y+1][i][0]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][2] = arrayLocal[0] | | +| MbDCLP[x][y+1][i][0] = arrayLocal[1] | | +| } | | + +| FirstLevelOverlapFiltering420(i) { | Reference | +|------------------------------------------------------------------------------------------|-----------| +| if ((HARD_TILING_FLAG == FALSE) && (Tx == NumTileCols - 1) && (Ty != NumTileRows - 1)) { | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| arrayLocal[ ] = {MbDCLP[x][y][i][3], MbDCLP[x][y+1][i][1]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][3] = arrayLocal[0] | | +| MbDCLP[x][y+1][i][1] = arrayLocal[1] | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx != NumTileCols - 1) && (Ty == 0)) { | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| y = TopMBIndexOfTile[Ty] | | +| arrayLocal[ ] = {MbDCLP[x][y][i][1], MbDCLP[x+1][y][i][0]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][1] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][0] = arrayLocal[1] | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx != NumTileCols - 1) && (Ty == NumTileRows - 1)) { | | +| x = LeftMBIndexOfTile[Tx + 1] - 1 | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| arrayLocal[ ] = {MbDCLP[x][y][i][3], MbDCLP[x+1][y][i][2]} | | +| OverlapPostFilter2(arrayLocal[ ]) | 9.9.8.4 | +| MbDCLP[x][y][i][3] = arrayLocal[0] | | +| MbDCLP[x+1][y][i][2] = arrayLocal[1] | | +| } | | +| if ((Ty == 0) (HARD_TILING_FLAG == TRUE)) { /*Top edge */ | | +| /* OverlapPostFilter1 */ | | +| y = TopMBIndexOfTile[Ty] | | +| MbDCLP[LeftMBIndexOfTile[0]][y][i][0] += MbDCLP[LeftMBIndexOfTile[0]][y][i][1] | | +| /* Upper left corner addition */ | | +| MbDCLP[LeftMBIndexOfTile[NumTileCols] - 1][y][i][1] += | | +| MbDCLP[LeftMBIndexOfTile[NumTileCols] - 1][y][i][0] /* Upper right corner addition */ | | +| if (HARD_TILING_FLAG == TRUE) | | +| for (Tx = 1; Tx < (NumTileCols - 1); Tx++) { | | +| MbDCLP[LeftMBIndexOfTile[Tx]][y][i][0] += MbDCLP[LeftMBIndexOfTile[Tx]][y][i][1] | | +| MbDCLP[LeftMBIndexOfTile[Tx] - 1][y][i][1] += | | +| MbDCLP[LeftMBIndexOfTile[Tx] - 1][y][i][0] | | +| } | | +| } | | +| if ((Ty == NumTileRows - 1) (HARD_TILING_FLAG == TRUE)) { /* Bottom edge */ | | +| /* OverlapPostFilter1 */ | | +| y = TopMBIndexOfTile[Ty + 1] - 1 | | +| MbDCLP[LeftMBIndexOfTile[0]][y][i][2] += MbDCLP[LeftMBIndexOfTile[0]][y][i][3] | | +| /* Bottom left corner addition */ | | +| MbDCLP[LeftMBIndexOfTile[NumTileCols] - 1][y][i][3] += | | +| MbDCLP[LeftMBIndexOfTile[NumTileCols] - 1][y][i][2] /* Bottom right corner addition */ | | +| if (HARD_TILING_FLAG == TRUE) | | +| for (Tx = 1; Tx < (NumTileCols - 1); Tx++) { | | +| MbDCLP[LeftMBIndexOfTile[Tx]][y][i][2] += MbDCLP[LeftMBIndexOfTile[Tx]][y][i][3] | | +| MbDCLP[LeftMBIndexOfTile[Tx] - 1][y][i][3] += | | +| MbDCLP[LeftMBIndexOfTile[Tx] - 1][y][i][2] | | +| } | | +| } | | +| } | | +| } | | + +### 9.9.3.5 FirstLevelCallOverlapPostFilter4x4() + +Pseudocode for the function FirstLevelCallOverlapPostFilter4x4() is specified in Table 156. + +**Table 156 – Pseudocode for function FirstLevelCallOverlapPostFilter4x4()** + +| FirstLevelCallOverlapPostFilter4x4(i, x, y) { | Reference | +|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------| +| arrayLocal[ ] = {MbDCLP[x][y][i][10], MbDCLP[x][y][i][11],
MbDCLP[x+1][y][i][8], MbDCLP[x+1][y][i][9],
MbDCLP[x][y][i][14], MbDCLP[x][y][i][15],
MbDCLP[x+1][y][i][12], MbDCLP[x+1][y][i][13],
MbDCLP[x][y+1][i][2], MbDCLP[x][y+1][i][3],
MbDCLP[x+1][y+1][i][0], MbDCLP[x+1][y+1][i][1],
MbDCLP[x][y+1][i][6], MbDCLP[x][y+1][i][7],
MbDCLP[x+1][y+1][i][4], MbDCLP[x+1][y+1][i][5]} | | +| OverlapPostFilter4x4(arrayLocal[ ]) | 9.9.8.1 | +| MbDCLP[x][y][i][10] = arrayLocal[0] | | +| MbDCLP[x][y][i][11] = arrayLocal[1] | | +| MbDCLP[x+1][y][i][8] = arrayLocal[2] | | +| MbDCLP[x+1][y][i][9] = arrayLocal[3] | | +| MbDCLP[x][y][i][14] = arrayLocal[4] | | +| MbDCLP[x][y][i][15] = arrayLocal[5] | | +| MbDCLP[x+1][y][i][12] = arrayLocal[6] | | +| MbDCLP[x+1][y][i][13] = arrayLocal[7] | | +| MbDCLP[x][y+1][i][2] = arrayLocal[8] | | +| MbDCLP[x][y+1][i][3] = arrayLocal[9] | | +| MbDCLP[x+1][y+1][i][0] = arrayLocal[10] | | +| MbDCLP[x+1][y+1][i][1] = arrayLocal[11] | | +| MbDCLP[x][y+1][i][6] = arrayLocal[12] | | +| MbDCLP[x][y+1][i][7] = arrayLocal[13] | | +| MbDCLP[x+1][y+1][i][4] = arrayLocal[14] | | +| MbDCLP[x+1][y+1][i][5] = arrayLocal[15] | | +| } | | + +### 9.9.4 Second level coefficient combination + +NOTE – At this point in the process, the DC-LP array coefficients have gone through the first level transform and overlap filtering. The DC-LP array coefficients and the HP coefficients are then combined in an image plane represented by the values ImagePlane[i][x][y], where the colour component is specified by i, and x and y mark the location of the sample in the image plane. + +Inputs to this process are the values MbDCLP[MBx][MBy][i][j] and MBBuffer[MBx][MBy][i][j], for the current macroblock. + +Outputs to this process are the values of ImagePlane[i][x][y], for the current macroblock. + +The second level coefficient combination process proceeds as specified in Table 157. + +**Table 157 – Pseudocode for function SecondLevelCoefficientCombination()** + +| SecondLevelCoefficientCombination() { | Reference | +|--------------------------------------------------------------------------------------|------------------| +| for (i = 0; i < NumComponents; i++) { | | +| for (MBy = 0; MBy < MBHeight; MBy++) | | +| for (MBx = 0; MBx < MBWidth; MBx++) | | +| if ((i == 0) ((INTERNAL_CLR_FMT != YUV420) &&
(INTERNAL_CLR_FMT != YUV422))) { | | +| for (j = 0; j <= 15; j++) { | | +| x = 16 * MBx + 4 * (j % 4) | | +| y = 16 * MBy + 4 * (j / 4) | | +| ImagePlane[i][x][y] = MbDCLP[MBx][MBy][i][j] | | +| } | | +| for (j = 0; j <= 255; j++) { | | +| x = 16 * MBx + 4 * ((j / 16) % 4) + (j % 4) | | +| y = 16 * MBy + 4 * (j / 64) + ((j / 4) % 4) | | +| k = j % 16 | | +| if (k != 0) /* only the HP coefficients are copied */ | | +| ImagePlane[i][x][y] = MBBuffer[MBx][MBy][i][j] | | +| } | | +| } else if (INTERNAL_CLR_FMT == YUV422) { | | +| for (j = 0; j <= 7; j++) { | | +| x = 8 * MBx + 4 * (j % 2) | | +| y = 16 * MBy + 4 * (j / 2) | | +| ImagePlane[i][x][y] = MbDCLP[MBx][MBy][i][j] | | +| } | | +| for (j = 0; j <= 127; j++) { | | +| x = 8 * MBx + 4 * ((j % 32) / 16) + ((j % 32) % 4) | | +| y = 16 * MBy + 4 * (j / 32) + ((j / 4) % 4) | | +| k = j % 16 | | +| if (k != 0) /* only the HP coefficients are copied */ | | +| ImagePlane[i][x][y] = MBBuffer[MBx][MBy][i][j] | | +| } | | +| } else if (INTERNAL_CLR_FMT == YUV420) { | | +| for (j = 0; j <= 3; j++) { | | +| x = 8 * MBx + 4 * (j % 2) | | +| y = 8 * MBy + 4 * (j / 2) | | +| ImagePlane[i][x][y] = MbDCLP[MBx][MBy][i][j] | | +| } | | +| for (j = 0; j <= 63; j++) { | | +| x = 8 * MBx + 4 * ((j % 32) / 16) + ((j % 32) % 4) | | +| y = 8 * MBy + 4 * (j / 32) + ((j / 4) % 4) | | +| k = j % 16 | | +| if (k != 0) /* only the HP coefficients are copied */ | | +| ImagePlane[i][x][y] = MBBuffer[MBx][MBy][i][j] | | +| } | | +| } | | +| } | | + +### 9.9.5 Second level inverse transform + +Inputs to this process are the values ImagePlane[i][x][y] for the entire image plane. + +Outputs to this process are the modified values ImagePlane[i][x][y] for the current macroblock. + +The second level inverse transform process is specified in Table 158. + +**Table 158 – Pseudocode for function SecondLevelInverseTransform()** + +| SecondLevelInverseTransform() { | Reference | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------| +| for (i = 0; i < NumComponents; i++) | | +| for (x = 0; x < ExtendedWidth[i]; x += 4) | | +| for (y = 0; y < ExtendedHeight[i]; y += 4) { | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y],
ImagePlane[i][x+2][y], ImagePlane[i][x+3][y],
ImagePlane[i][x][y+1], ImagePlane[i][x+1][y+1],
ImagePlane[i][x+2][y+1], ImagePlane[i][x+3][y+1],
ImagePlane[i][x][y+2], ImagePlane[i][x+1][y+2],
ImagePlane[i][x+2][y+2], ImagePlane[i][x+3][y+2],
ImagePlane[i][x][y+3], ImagePlane[i][x+1][y+3],
ImagePlane[i][x+2][y+3], ImagePlane[i][x+3][y+3]} | | +| ICT4x4(arrayLocal[ ]) | 9.9.7.1 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | +| ImagePlane[i][x+2][y] = arrayLocal[2] | | +| ImagePlane[i][x+3][y] = arrayLocal[3] | | +| ImagePlane[i][x][y+1] = arrayLocal[4] | | +| ImagePlane[i][x+1][y+1] = arrayLocal[5] | | +| ImagePlane[i][x+2][y+1] = arrayLocal[6] | | +| ImagePlane[i][x+3][y+1] = arrayLocal[7] | | +| ImagePlane[i][x][y+2] = arrayLocal[8] | | +| ImagePlane[i][x+1][y+2] = arrayLocal[9] | | +| ImagePlane[i][x+2][y+2] = arrayLocal[10] | | +| ImagePlane[i][x+3][y+2] = arrayLocal[11] | | +| ImagePlane[i][x][y+3] = arrayLocal[12] | | +| ImagePlane[i][x+1][y+3] = arrayLocal[13] | | +| ImagePlane[i][x+2][y+3] = arrayLocal[14] | | +| ImagePlane[i][x+3][y+3] = arrayLocal[15] | | +| } | | +| } | | + +### 9.9.6 Second level overlap filtering + +Inputs to this process are the values ImagePlane[i][x][y] for the entire image plane. + +Outputs to this process are the modified values ImagePlane[i][x][y] for the entire image plane. + +Outputs to this process are the modified values ImagePlane[i][x][y] for the current macroblock. + +NOTE – The process specification below formalizes the geometric nature of the overlap filtering process. There are 4 cases. + +(1) (interior): at every point in the image plane where 4 blocks meet in a corner, the 4×4 overlap filter is applied to the 4×4 block straddling these 4 blocks evenly (i.e., overlapping with a 2×2 corner of each block). + +(2) (top and bottom 2 rows): along both the top two sample rows and the bottom two sample rows of the image plane, the 4-point overlap filter is applied evenly across adjacent block boundaries (overlapping with a 1×2 strip of each block). + +(3) (rightmost and leftmost columns): along both the leftmost two sample columns and the rightmost two sample columns, the 4-point overlap filter is applied evenly across adjacent block boundaries (overlapping with a 2×1 strip of each block). + +(4) (four corners of the image plane): over the corner 2×2 blocks in the top-left, top-right, bottom-left and bottom-right, the 4-point overlap filter process is applied in a raster scan order (top-left, top-right, bottom-left, then bottom-right). + +The second level overlap filtering process is specified in Table 159. + +**Table 159 – Pseudocode for function SecondLevelOverlapFiltering( )** + +| SecondLevelOverlapFiltering() { | Reference | +|---------------------------------------------------------------------------------|------------------| +| for (i = 0; i < NumComponents; i++) { | | +| if ((i != 0) && ((INTERNAL_CLR_FMT == YUV422) (INTERNAL_CLR_FMT == YUV420))) | | +| dx = 2 | | +| else | | +| dx = 1 | | +| if ((i != 0) && (INTERNAL_CLR_FMT == YUV420)) | | +| dy = 2 | | +| else | | +| dy = 1 | | + +| SecondLevelOverlapFiltering() { | Reference | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------| +| for (Tx = 0; Tx <= (NumTileCols - 1); Tx++) { | | +| for (Ty = 0; Ty <= (NumTileRows - 1); Ty++) { | | +| for (x = 16 * LeftMBIndexOfTile[Tx] / dx + 2; x < (16 * LeftMBIndexOfTile[Tx + 1] / dx - 2);
x += 4) | | +| for (y = 16 * TopMBIndexOfTile[Ty] / dy + 2; y < (16 * TopMBIndexOfTile[Ty + 1] / dy - 2);
y += 4) { | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y],
ImagePlane[i][x+2][y], ImagePlane[i][x+3][y],
ImagePlane[i][x][y+1], ImagePlane[i][x+1][y+1],
ImagePlane[i][x+2][y+1], ImagePlane[i][x+3][y+1],
ImagePlane[i][x][y+2], ImagePlane[i][x+1][y+2],
ImagePlane[i][x+2][y+2], ImagePlane[i][x+3][y+2],
ImagePlane[i][x][y+3], ImagePlane[i][x+1][y+3],
ImagePlane[i][x+2][y+3], ImagePlane[i][x+3][y+3]} | | +| OverlapPostFilter4x4(arrayLocal[ ]) | 9.9.8.1 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | +| ImagePlane[i][x+2][y] = arrayLocal[2] | | +| ImagePlane[i][x+3][y] = arrayLocal[3] | | +| ImagePlane[i][x][y+1] = arrayLocal[4] | | +| ImagePlane[i][x+1][y+1] = arrayLocal[5] | | +| ImagePlane[i][x+2][y+1] = arrayLocal[6] | | +| ImagePlane[i][x+3][y+1] = arrayLocal[7] | | +| ImagePlane[i][x][y+2] = arrayLocal[8] | | +| ImagePlane[i][x+1][y+2] = arrayLocal[9] | | +| ImagePlane[i][x+2][y+2] = arrayLocal[10] | | +| ImagePlane[i][x+3][y+2] = arrayLocal[11] | | +| ImagePlane[i][x][y+3] = arrayLocal[12] | | +| ImagePlane[i][x+1][y+3] = arrayLocal[13] | | +| ImagePlane[i][x+2][y+3] = arrayLocal[14] | | +| ImagePlane[i][x+3][y+3] = arrayLocal[15] | | +| } | | +| if ((Tx == 0) (HARD_TILING_FLAG == TRUE)) { /* Left edge */ | | +| for (y = 16 * TopMBIndexOfTile[Ty] / dy + 2; y < (16 * TopMBIndexOfTile[Ty + 1] / dy - 2);
y += 4) { | | +| x = 16 * LeftMBIndexOfTile[Tx] / dx | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x][y+1],
ImagePlane[i][x][y+2], ImagePlane[i][x][y+3]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x][y+1] = arrayLocal[1] | | +| ImagePlane[i][x][y+2] = arrayLocal[2] | | +| ImagePlane[i][x][y+3] = arrayLocal[3] | | +| x = 16 * LeftMBIndexOfTile[Tx] / dx + 1 | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x][y+1],
ImagePlane[i][x][y+2], ImagePlane[i][x][y+3]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | + +| SecondLevelOverlapFiltering() { | Reference | +|----------------------------------------------------------------------------------------------|-----------| +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x][y+1] = arrayLocal[1] | | +| ImagePlane[i][x][y+2] = arrayLocal[2] | | +| ImagePlane[i][x][y+3] = arrayLocal[3] | | +| } | | +| } | | +| if ((Ty == 0) (HARD_TILING_FLAG == TRUE)) { /* Top edge */ | | +| for (x = 16 * LeftMBIndexOfTile[Tx] / dx + 2; x < (16 * LeftMBIndexOfTile[Tx + 1] / dx - 2); | | +| x += 4) { | | +| y = 16 * TopMBIndexOfTile[Ty] / dy | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y], | | +| ImagePlane[i][x+2][y], ImagePlane[i][x+3][y]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | +| ImagePlane[i][x+2][y] = arrayLocal[2] | | +| ImagePlane[i][x+3][y] = arrayLocal[3] | | +| y = 16 * TopMBIndexOfTile[Ty] / dy + 1 | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y], | | +| ImagePlane[i][x+2][y], ImagePlane[i][x+3][y]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | +| ImagePlane[i][x+2][y] = arrayLocal[2] | | +| ImagePlane[i][x+3][y] = arrayLocal[3] | | +| } | | +| } | | +| if ((Tx == NumTileCols - 1) (HARD_TILING_FLAG == TRUE)) { /* Right edge */ | | +| for (y = 16 * TopMBIndexOfTile[Ty] / dy + 2; y < (16 * TopMBIndexOfTile[Ty + 1] / dy - 2); | | +| y += 4) { | | +| x = 16 * LeftMBIndexOfTile[Tx + 1] / dx - 2 | | +| arrayLocal[ ] = { ImagePlane[i][x][y], ImagePlane[i][x][y+1], | | +| ImagePlane[i][x][y+2], ImagePlane[i][x][y+3]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x][y+1] = arrayLocal[1] | | +| ImagePlane[i][x][y+2] = arrayLocal[2] | | +| ImagePlane[i][x][y+3] = arrayLocal[3] | | +| x = 16 * LeftMBIndexOfTile[Tx + 1] / dx - 1 | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x][y+1], | | +| ImagePlane[i][x][y+2], ImagePlane[i][x][y+3]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x][y+1] = arrayLocal[1] | | +| ImagePlane[i][x][y+2] = arrayLocal[2] | | +| ImagePlane[i][x][y+3] = arrayLocal[3] | | +| } | | +| } | | +| if ((Ty == NumTileRows - 1) (HARD_TILING_FLAG == TRUE)) { /* Bottom edge */ | | +| for (x = 16 * LeftMBIndexOfTile[Tx] / dx + 2; x < (16 * LeftMBIndexOfTile[Tx + 1] / dx - 2); | | +| x += 4) { | | +| y = 16 * TopMBIndexOfTile[Ty + 1] / dy - 2 | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y], | | +| ImagePlane[i][x+2][y], ImagePlane[i][x+3][y]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | +| ImagePlane[i][x+2][y] = arrayLocal[2] | | +| ImagePlane[i][x+3][y] = arrayLocal[3] | | +| y = 16 * TopMBIndexOfTile[Ty + 1] / dy - 1 | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y], | | +| ImagePlane[i][x+2][y], ImagePlane[i][x+3][y]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | + +| SecondLevelOverlapFiltering() { | Reference | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------| +| ImagePlane[i][x+2][y] = arrayLocal[2] | | +| ImagePlane[i][x+3][y] = arrayLocal[3] | | +| } | | +| if (((Tx == 0) && (Ty == 0)) (HARD_TILING_FLAG == TRUE)) { /* Top left edge */ | | +| x = 16 * LeftMBIndexOfTile[Tx] / dx | | +| y = 16 * TopMBIndexOfTile[Ty] / dy | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y],
ImagePlane[i][x][y+1], ImagePlane[i][x+1][y+1]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | +| ImagePlane[i][x][y+1] = arrayLocal[2] | | +| ImagePlane[i][x+1][y+1] = arrayLocal[3] | | +| } | | +| if (((Tx == NumTileCols - 1) && (Ty == 0)) (HARD_TILING_FLAG == TRUE)) { | | +| /* Top right edge */ | | +| x = 16 * LeftMBIndexOfTile[Tx + 1] / dx - 2 | | +| y = 16 * TopMBIndexOfTile[Ty] / dy | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y],
ImagePlane[i][x][y+1], ImagePlane[i][x+1][y+1]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | +| ImagePlane[i][x][y+1] = arrayLocal[2] | | +| ImagePlane[i][x+1][y+1] = arrayLocal[3] | | +| } | | +| if (((Tx == 0) && (Ty == NumTileRows - 1)) (HARD_TILING_FLAG == TRUE)) { | | +| /* Bottom left edge */ | | +| x = 16 * LeftMBIndexOfTile[Tx] / dx | | +| y = 16 * TopMBIndexOfTile[Ty + 1] / dy - 2 | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y],
ImagePlane[i][x][y+1], ImagePlane[i][x+1][y+1]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | +| ImagePlane[i][x][y+1] = arrayLocal[2] | | +| ImagePlane[i][x+1][y+1] = arrayLocal[3] | | +| } | | +| if (((Tx == NumTileCols - 1) && (Ty == NumTileRows - 1))
(HARD_TILING_FLAG == TRUE)) { /* Bottom right edge */ | | +| x = 16 * LeftMBIndexOfTile[Tx + 1] / dx - 2 | | +| y = 16 * TopMBIndexOfTile[Ty + 1] / dy - 2 | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y],
ImagePlane[i][x][y+1], ImagePlane[i][x+1][y+1]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | +| ImagePlane[i][x][y+1] = arrayLocal[2] | | +| ImagePlane[i][x+1][y+1] = arrayLocal[3] | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx != NumTileCols - 1)) { | | +| /* Right across for soft tiles */ | | +| x = 16 * LeftMBIndexOfTile[Tx + 1] / dx - 2 | | +| for (y = 16 * TopMBIndexOfTile[Ty] / dy + 2; y < (16 * TopMBIndexOfTile[Ty + 1] / dy - 2);
y += 4) { | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y],
ImagePlane[i][x+2][y], ImagePlane[i][x+3][y],
ImagePlane[i][x][y+1], ImagePlane[i][x+1][y+1],
ImagePlane[i][x+2][y+1], ImagePlane[i][x+3][y+1],
ImagePlane[i][x][y+2], ImagePlane[i][x+1][y+2],
ImagePlane[i][x+2][y+2], ImagePlane[i][x+3][y+2],
ImagePlane[i][x][y+3], ImagePlane[i][x+1][y+3],
ImagePlane[i][x+2][y+3], ImagePlane[i][x+3][y+3]} | | +| OverlapPostFilter4x4(arrayLocal[ ]) | 9.9.8.1 | + +| SecondLevelOverlapFiltering() { | Reference | +|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------| +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | +| ImagePlane[i][x+2][y] = arrayLocal[2] | | +| ImagePlane[i][x+3][y] = arrayLocal[3] | | +| ImagePlane[i][x][y+1] = arrayLocal[4] | | +| ImagePlane[i][x+1][y+1] = arrayLocal[5] | | +| ImagePlane[i][x+2][y+1] = arrayLocal[6] | | +| ImagePlane[i][x+3][y+1] = arrayLocal[7] | | +| ImagePlane[i][x][y+2] = arrayLocal[8] | | +| ImagePlane[i][x+1][y+2] = arrayLocal[9] | | +| ImagePlane[i][x+2][y+2] = arrayLocal[10] | | +| ImagePlane[i][x+3][y+2] = arrayLocal[11] | | +| ImagePlane[i][x][y+3] = arrayLocal[12] | | +| ImagePlane[i][x+1][y+3] = arrayLocal[13] | | +| ImagePlane[i][x+2][y+3] = arrayLocal[14] | | +| ImagePlane[i][x+3][y+3] = arrayLocal[15] | | +| } | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Ty != NumTileRows - 1)) { | | +| /* Bottom across for soft tiles */ | | +| y = 16 * TopMBIndexOfTile[Ty + 1] / dy - 2 | | +| for (x = 16 * LeftMBIndexOfTile[Tx] / dx + 2; x < (16 * LeftMBIndexOfTile[Tx + 1] / dx - 2); | | +| x += 4) { | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y],
ImagePlane[i][x+2][y], ImagePlane[i][x+3][y],
ImagePlane[i][x][y+1], ImagePlane[i][x+1][y+1],
ImagePlane[i][x+2][y+1], ImagePlane[i][x+3][y+1],
ImagePlane[i][x][y+2], ImagePlane[i][x+1][y+2],
ImagePlane[i][x+2][y+2], ImagePlane[i][x+3][y+2],
ImagePlane[i][x][y+3], ImagePlane[i][x+1][y+3],
ImagePlane[i][x+2][y+3], ImagePlane[i][x+3][y+3]} | | +| OverlapPostFilter4x4(arrayLocal[ ]) | 9.9.8.1 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | +| ImagePlane[i][x+2][y] = arrayLocal[2] | | +| ImagePlane[i][x+3][y] = arrayLocal[3] | | +| ImagePlane[i][x][y+1] = arrayLocal[4] | | +| ImagePlane[i][x+1][y+1] = arrayLocal[5] | | +| ImagePlane[i][x+2][y+1] = arrayLocal[6] | | +| ImagePlane[i][x+3][y+1] = arrayLocal[7] | | +| ImagePlane[i][x][y+2] = arrayLocal[8] | | +| ImagePlane[i][x+1][y+2] = arrayLocal[9] | | +| ImagePlane[i][x+2][y+2] = arrayLocal[10] | | +| ImagePlane[i][x+3][y+2] = arrayLocal[11] | | +| ImagePlane[i][x][y+3] = arrayLocal[12] | | +| ImagePlane[i][x+1][y+3] = arrayLocal[13] | | +| ImagePlane[i][x+2][y+3] = arrayLocal[14] | | +| ImagePlane[i][x+3][y+3] = arrayLocal[15] | | +| } | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx != NumTileCols - 1) && | | +| (Ty != NumTileRows - 1)) { | | +| x = 16 * LeftMBIndexOfTile[Tx + 1] / dx - 2 | | +| y = 16 * TopMBIndexOfTile[Ty + 1] / dy - 2 | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y],
ImagePlane[i][x+2][y], ImagePlane[i][x+3][y],
ImagePlane[i][x][y+1], ImagePlane[i][x+1][y+1],
ImagePlane[i][x+2][y+1], ImagePlane[i][x+3][y+1],
ImagePlane[i][x][y+2], ImagePlane[i][x+1][y+2],
ImagePlane[i][x+2][y+2], ImagePlane[i][x+3][y+2],
ImagePlane[i][x][y+3], ImagePlane[i][x+1][y+3],
ImagePlane[i][x+2][y+3], ImagePlane[i][x+3][y+3]} | | +| OverlapPostFilter4x4(arrayLocal[ ]) | 9.9.8.1 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | + +| SecondLevelOverlapFiltering() { | Reference | +|-----------------------------------------------------------------------------------------------------------------------------|-----------| +| ImagePlane[i][x+2][y] = arrayLocal[2] | | +| ImagePlane[i][x+3][y] = arrayLocal[3] | | +| ImagePlane[i][x][y+1] = arrayLocal[4] | | +| ImagePlane[i][x+1][y+1] = arrayLocal[5] | | +| ImagePlane[i][x+2][y+1] = arrayLocal[6] | | +| ImagePlane[i][x+3][y+1] = arrayLocal[7] | | +| ImagePlane[i][x][y+2] = arrayLocal[8] | | +| ImagePlane[i][x+1][y+2] = arrayLocal[9] | | +| ImagePlane[i][x+2][y+2] = arrayLocal[10] | | +| ImagePlane[i][x+3][y+2] = arrayLocal[11] | | +| ImagePlane[i][x][y+3] = arrayLocal[12] | | +| ImagePlane[i][x+1][y+3] = arrayLocal[13] | | +| ImagePlane[i][x+2][y+3] = arrayLocal[14] | | +| ImagePlane[i][x+3][y+3] = arrayLocal[15] | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx == 0) && (Ty != NumTileRows - 1)) { | | +| /* Left edge for soft tiles */ | | +| y = 16 * TopMBIndexOfTile[Ty + 1] / dy - 2 | | +| x = 16 * LeftMBIndexOfTile[Tx] / dx | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x][y+1],
ImagePlane[i][x][y+2], ImagePlane[i][x][y+3]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x][y+1] = arrayLocal[1] | | +| ImagePlane[i][x][y+2] = arrayLocal[2] | | +| ImagePlane[i][x][y+3] = arrayLocal[3] | | +| x = 16 * LeftMBIndexOfTile[Tx] / dx + 1 | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x][y+1],
ImagePlane[i][x][y+2], ImagePlane[i][x][y+3]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x][y+1] = arrayLocal[1] | | +| ImagePlane[i][x][y+2] = arrayLocal[2] | | +| ImagePlane[i][x][y+3] = arrayLocal[3] | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx != NumTileCols - 1) && (Ty == 0)) { | | +| /* Top edge for soft tiles */ | | +| x = 16 * LeftMBIndexOfTile[Tx + 1] / dx - 2 | | +| y = 16 * TopMBIndexOfTile[Ty] / dy | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y],
ImagePlane[i][x+2][y], ImagePlane[i][x+3][y]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | +| ImagePlane[i][x+2][y] = arrayLocal[2] | | +| ImagePlane[i][x+3][y] = arrayLocal[3] | | +| y = 16 * TopMBIndexOfTile[Ty] / dy + 1 | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y],
ImagePlane[i][x+2][y], ImagePlane[i][x+3][y]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | +| ImagePlane[i][x+2][y] = arrayLocal[2] | | +| ImagePlane[i][x+3][y] = arrayLocal[3] | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx == NumTileCols - 1) &&
(Ty != NumTileRows - 1)) { /* Right edge for soft tiles */ | | +| y = 16 * TopMBIndexOfTile[Ty + 1] / dy - 2 | | +| x = 16 * LeftMBIndexOfTile[Tx + 1] / dx - 2 | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x][y+1],
ImagePlane[i][x][y+2], ImagePlane[i][x][y+3]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x][y+1] = arrayLocal[1] | | +| ImagePlane[i][x][y+2] = arrayLocal[2] | | + +| SecondLevelOverlapFiltering() { | Reference | +|------------------------------------------------------------------------------------------------------------------------------|-----------| +| ImagePlane[i][x][y+3] = arrayLocal[3] | | +| x = 16 * LeftMBIndexOfTile[Tx + 1] / dx - 1 | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x][y+1],
ImagePlane[i][x][y+2], ImagePlane[i][x][y+3]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x][y+1] = arrayLocal[1] | | +| ImagePlane[i][x][y+2] = arrayLocal[2] | | +| ImagePlane[i][x][y+3] = arrayLocal[3] | | +| } | | +| if ((HARD_TILING_FLAG == FALSE) && (Tx != NumTileCols - 1) &&
(Ty == NumTileRows - 1)) { /* Bottom edge for soft tiles */ | | +| x = 16 * LeftMBIndexOfTile[Tx + 1] / dx - 2 | | +| y = 16 * TopMBIndexOfTile[Ty + 1] / dy - 2 | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y],
ImagePlane[i][x+2][y], ImagePlane[i][x+3][y]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | +| ImagePlane[i][x+2][y] = arrayLocal[2] | | +| ImagePlane[i][x+3][y] = arrayLocal[3] | | +| y = 16 * TopMBIndexOfTile[Ty + 1] / dy - 1 | | +| arrayLocal[ ] = {ImagePlane[i][x][y], ImagePlane[i][x+1][y],
ImagePlane[i][x+2][y], ImagePlane[i][x+3][y]} | | +| OverlapPostFilter4(arrayLocal[ ]) | 9.9.8.2 | +| ImagePlane[i][x][y] = arrayLocal[0] | | +| ImagePlane[i][x+1][y] = arrayLocal[1] | | +| ImagePlane[i][x+2][y] = arrayLocal[2] | | +| ImagePlane[i][x+3][y] = arrayLocal[3] | | +| } | | +| } | | +| } | | +| } | | +| } | | + +## 9.9.7 Inverse transform basic operations + +### 9.9.7.1 ICT4x4() + +NOTE 1 – The 2D ICT4x4() is built using the three operators: T2x2h, InvTodd and InvToddodd, preceded by the permutation function InvPermute. After the initial permutation, the transform operation consists of two stages, where each stage operates on all 16 of the input values. + +The function ICT4x4() is specified by the pseudocode in Table 160. + +**Table 160 – Pseudocode for function ICT4x4()** + +| ICT4x4(iCoeff[ ]) | Reference | +|----------------------------------------------------------------|-----------| +| /* Permute the coefficients */ | | +| InvPermute(iCoeff[ ]) | 9.9.7.5 | +| /* First stage */ | | +| arrayLocal[ ] = {iCoeff[0], iCoeff[1], iCoeff[4], iCoeff[5]} | | +| T2x2h(arrayLocal[ ], 1) | 9.9.7.2 | +| iCoeff[0] = arrayLocal[0] | | +| iCoeff[1] = arrayLocal[1] | | +| iCoeff[4] = arrayLocal[2] | | +| iCoeff[5] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[2], iCoeff[3], iCoeff[6], iCoeff[7]} | | +| InvTodd(arrayLocal[ ]) | 9.9.7.3 | +| iCoeff[2] = arrayLocal[0] | | +| iCoeff[3] = arrayLocal[1] | | +| iCoeff[6] = arrayLocal[2] | | +| iCoeff[7] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[8], iCoeff[12], iCoeff[9], iCoeff[13]} | | + +| ICT4x4(iCoeff[ ]) { | Reference | +|------------------------------------------------------------------|------------------| +| InvTodd(arrayLocal[ ]) | 9.9.7.3 | +| iCoeff[8] = arrayLocal[0] | | +| iCoeff[12] = arrayLocal[1] | | +| iCoeff[9] = arrayLocal[2] | | +| iCoeff[13] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[10], iCoeff[11], iCoeff[14], iCoeff[15]} | | +| InvToddodd(arrayLocal[ ]) | 9.9.7.4 | +| iCoeff[10] = arrayLocal[0] | | +| iCoeff[11] = arrayLocal[1] | | +| iCoeff[14] = arrayLocal[2] | | +| iCoeff[15] = arrayLocal[3] | | +| /* Second stage */ | | +| arrayLocal[ ] = {iCoeff[0], iCoeff[3], iCoeff[12], iCoeff[15]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| iCoeff[0] = arrayLocal[0] | | +| iCoeff[3] = arrayLocal[1] | | +| iCoeff[12] = arrayLocal[2] | | +| iCoeff[15] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[5], iCoeff[6], iCoeff[9], iCoeff[10]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| iCoeff[5] = arrayLocal[0] | | +| iCoeff[6] = arrayLocal[1] | | +| iCoeff[9] = arrayLocal[2] | | +| iCoeff[10] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[1], iCoeff[2], iCoeff[13], iCoeff[14]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| iCoeff[1] = arrayLocal[0] | | +| iCoeff[2] = arrayLocal[1] | | +| iCoeff[13] = arrayLocal[2] | | +| iCoeff[14] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[4], iCoeff[7], iCoeff[8], iCoeff[11]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| iCoeff[4] = arrayLocal[0] | | +| iCoeff[7] = arrayLocal[1] | | +| iCoeff[8] = arrayLocal[2] | | +| iCoeff[11] = arrayLocal[3] | | +| } | | + +NOTE 2 – Each stage consists of four 2×2 transforms that may be done in any arbitrary sequence or concurrently within the stage. However, the first stage transforms must be complete before any of the second stage transforms are initiated. + +### 9.9.7.2 T2x2h( ) + +The function T2x2h( ) is specified in Table 161. + +NOTE – The variable valRound is a rounding control variable. The value of valRound is set to 0 or 1 by the function that invokes T2x2h( ). The inverse of T2x2Th( ) is two successive applications of T2x2Th, operating on variables of the array iCoeff[ ] with the same value of valRound. + +**Table 161 – Pseudocode for function T2x2h( )** + +| T2x2h(iCoeff[ ], valRound) { | Reference | +|---------------------------------------------------|------------------| +| iCoeff[0] += iCoeff[3] | | +| iCoeff[1] -= iCoeff[2] | | +| valT1 = ((iCoeff[0] - iCoeff[1] + valRound) >> 1) | | +| valT2 = iCoeff[2] | | +| iCoeff[2] = valT1 - iCoeff[3] | | +| iCoeff[3] = valT1 - valT2 | | +| iCoeff[0] -= iCoeff[3] | | +| iCoeff[1] += iCoeff[2] | | +| } | | + +### 9.9.7.3 InvTodd() + +The function InvTodd() is specified by the pseudocode in Table 162. + +**Table 162 – Pseudocode for function InvTodd()** + +| InvTodd(iCoeff[ ]) { | Reference | +|------------------------------------------------|------------------| +| iCoeff[1] += iCoeff[3] | | +| iCoeff[0] -= iCoeff[2] | | +| iCoeff[3] -= (iCoeff[1] >> 1) | | +| iCoeff[2] += ((iCoeff[0] + 1) >> 1) | | +| iCoeff[0] -= ((3* iCoeff[1] + 4) >> 3) | | +| iCoeff[1] += ((3* iCoeff[0] + 4) >> 3) | | +| iCoeff[2] -= ((3* iCoeff[3] + 4) >> 3) | | +| iCoeff[3] += ((3* iCoeff[2] + 4) >> 3) | | +| iCoeff[2] -= ((iCoeff[1] + 1) >> 1) | | +| iCoeff[3] = ((iCoeff[0] + 1) >> 1) - iCoeff[3] | | +| iCoeff[1] += iCoeff[2] | | +| iCoeff[0] -= iCoeff[3] | | +| } | | + +### 9.9.7.4 InvToddodd() + +The function, InvToddodd() is specified by the pseudocode in Table 163. + +**Table 163 – Pseudocode for function InvToddodd** + +| InvToddodd(iCoeff[ ]) { | Reference | +|-----------------------------------------|------------------| +| iCoeff[3] += iCoeff[0] | | +| iCoeff[2] -= iCoeff[1] | | +| valT1 = iCoeff[3] >> 1 | | +| valT2 = iCoeff[2] >> 1 | | +| iCoeff[0] -= valT1 | | +| iCoeff[1] += valT2 | | +| iCoeff[0] -= ((iCoeff[1] * 3 + 3) >> 3) | | +| iCoeff[1] += ((iCoeff[0] * 3 + 3) >> 2) | | +| iCoeff[0] -= ((iCoeff[1] * 3 + 4) >> 3) | | +| iCoeff[1] -= valT2 | | +| iCoeff[0] += valT1 | | +| iCoeff[2] += iCoeff[1] | | +| iCoeff[3] -= iCoeff[0] | | +| iCoeff[1] = -iCoeff[1] | | +| iCoeff[2] = -iCoeff[2] | | +| } | | + +### 9.9.7.5 InvPermute() + +The function InvPermute() operates on an ordered array of 16 sample values, producing a permuted list. The input to this function is the ordered array arrayInput[i], for i ranging from 0 to 15. The output of this function is the re-ordered array arrayInput[i]. + +To define the permutation, the array InvPermArr[i] is specified, for i ranging from 0 to 15, in Table 164. + +**Table 164 – Inverse permutation** + +| i | InvPermArr[i] | +|----------|----------------------| +| 0 | 0 | +| 1 | 8 | +| 2 | 4 | +| 3 | 13 | +| 4 | 2 | + +| i | InvPermArr[i] | +|----|---------------| +| 5 | 15 | +| 6 | 3 | +| 7 | 14 | +| 8 | 1 | +| 9 | 12 | +| 10 | 5 | +| 11 | 9 | +| 12 | 7 | +| 13 | 11 | +| 14 | 6 | +| 15 | 10 | + +The function InvPermute( ) is specified in Table 165. + +**Table 165 – Pseudocode for function InvPermute( )** + +| InvPermute(arrayInput[ ]) { | Reference | +|------------------------------------------|-----------| +| for (i = 0; i <= 15; i++) | | +| arrayTemp[InvPermArr[i]] = arrayInput[i] | | +| for (i = 0; i <= 15; i++) | | +| arrayInput[i] = arrayTemp[i] | | +| } | | + +#### 9.9.7.6 InvPermute2pt( ) + +The function InvPermute2pt( ) operates on an ordered array of 2 sample values, producing a permuted list. The input to this function is the ordered array arrayInput[i], for i ranging from 0 to 1. The output of this function is the re-ordered array arrayInput[i]. + +The function InvPermute2pt( ) is specified in Table 166. + +**Table 166 – Pseudocode for function InvPermute2pt( )** + +| InvPermute2pt( ) { | Reference | +|------------------------------|-----------| +| arrayTemp[0] = arrayInput[1] | | +| arrayTemp[1] = arrayInput[0] | | +| for (i = 0; i <= 1; i++) | | +| arrayInput[i] = arrayTemp[i] | | +| } | | + +#### 9.9.7.7 T2pt( ) + +The function T2pt( ) is specified by the pseudocode in Table 167. + +**Table 167 – Pseudocode for function T2pt( )** + +| T2pt(iCoeff[ ]) { | Reference | +|---------------------------------|-----------| +| iCoeff[0] -= (iCoeff[1]+1) >> 1 | | +| iCoeff[1] += iCoeff[0] | | +| } | | + +### 9.9.8 Overlap filtering functions + +#### 9.9.8.1 OverlapPostFilter4x4( ) + +The function OverlapPostFilter4x4( ) is specified in Table 168. + +**Table 168 – Pseudocode for function OverlapPostFilter4x4()** + +| OverlapPostFilter4x4(iCoeff[ ]) { | Reference | +|------------------------------------------------------------------|------------------| +| arrayLocal[ ] = {iCoeff[0], iCoeff[3], iCoeff[12], iCoeff[15]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| iCoeff[0] = arrayLocal[0] | | +| iCoeff[3] = arrayLocal[1] | | +| iCoeff[12] = arrayLocal[2] | | +| iCoeff[15] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[1], iCoeff[2], iCoeff[13], iCoeff[14]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| iCoeff[1] = arrayLocal[0] | | +| iCoeff[2] = arrayLocal[1] | | +| iCoeff[13] = arrayLocal[2] | | +| iCoeff[14] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[4], iCoeff[7], iCoeff[8], iCoeff[11]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| iCoeff[4] = arrayLocal[0] | | +| iCoeff[7] = arrayLocal[1] | | +| iCoeff[8] = arrayLocal[2] | | +| iCoeff[11] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[5], iCoeff[6], iCoeff[9], iCoeff[10]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| iCoeff[5] = arrayLocal[0] | | +| iCoeff[6] = arrayLocal[1] | | +| iCoeff[9] = arrayLocal[2] | | +| iCoeff[10] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[13], iCoeff[12]} | | +| InvRotate(arrayLocal[ ]) | 9.9.8.5 | +| iCoeff[13] = arrayLocal[0] | | +| iCoeff[12] = arrayLocal[1] | | +| arrayLocal[ ] = {iCoeff[9], iCoeff[8]} | | +| InvRotate(arrayLocal[ ]) | 9.9.8.5 | +| iCoeff[9] = arrayLocal[0] | | +| iCoeff[8] = arrayLocal[1] | | +| arrayLocal[ ] = {iCoeff[7], iCoeff[3]} | | +| InvRotate(arrayLocal[ ]) | 9.9.8.5 | +| iCoeff[7] = arrayLocal[0] | | +| iCoeff[3] = arrayLocal[1] | | +| arrayLocal[ ] = {iCoeff[6], iCoeff[2]} | | +| InvRotate(arrayLocal[ ]) | 9.9.8.5 | +| iCoeff[6] = arrayLocal[0] | | +| iCoeff[2] = arrayLocal[1] | | +| arrayLocal[ ] = {iCoeff[10], iCoeff[11], iCoeff[14], iCoeff[15]} | | +| InvToddoddPOST(arrayLocal[ ]) | 9.9.8.8 | +| iCoeff[10] = arrayLocal[0] | | +| iCoeff[11] = arrayLocal[1] | | +| iCoeff[14] = arrayLocal[2] | | +| iCoeff[15] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[0], iCoeff[15]} | | +| InvScale(arrayLocal[ ]) | 9.9.8.6 | +| iCoeff[0] = arrayLocal[0] | | +| iCoeff[15] = arrayLocal[1] | | +| arrayLocal[ ] = {iCoeff[1], iCoeff[14]} | | +| InvScale(arrayLocal[ ]) | 9.9.8.6 | +| iCoeff[1] = arrayLocal[0] | | +| iCoeff[14] = arrayLocal[1] | | +| arrayLocal[ ] = {iCoeff[4], iCoeff[11]} | | +| InvScale(arrayLocal[ ]) | 9.9.8.6 | +| iCoeff[4] = arrayLocal[0] | | +| iCoeff[11] = arrayLocal[1] | | +| arrayLocal[ ] = {iCoeff[5], iCoeff[10]} | | +| InvScale(arrayLocal[ ]) | 9.9.8.6 | +| iCoeff[5] = arrayLocal[0] | | +| iCoeff[10] = arrayLocal[1] | | + +| OverlapPostFilter4x4(iCoeff[ ]) { | Reference | +|----------------------------------------------------------------|------------------| +| arrayLocal[ ] = {iCoeff[0], iCoeff[3], iCoeff[12], iCoeff[15]} | | +| T2x2hPOST(arrayLocal[ ]) | 9.9.8.7 | +| iCoeff[0] = arrayLocal[0] | | +| iCoeff[3] = arrayLocal[1] | | +| iCoeff[12] = arrayLocal[2] | | +| iCoeff[15] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[1], iCoeff[2], iCoeff[13], iCoeff[14]} | | +| T2x2hPOST(arrayLocal[ ]) | 9.9.8.7 | +| iCoeff[1] = arrayLocal[0] | | +| iCoeff[2] = arrayLocal[1] | | +| iCoeff[13] = arrayLocal[2] | | +| iCoeff[14] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[4], iCoeff[7], iCoeff[8], iCoeff[11]} | | +| T2x2hPOST(arrayLocal[ ]) | 9.9.8.7 | +| iCoeff[4] = arrayLocal[0] | | +| iCoeff[7] = arrayLocal[1] | | +| iCoeff[8] = arrayLocal[2] | | +| iCoeff[11] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[5], iCoeff[6], iCoeff[9], iCoeff[10]} | | +| T2x2hPOST(arrayLocal[ ]) | 9.9.8.7 | +| iCoeff[5] = arrayLocal[0] | | +| iCoeff[6] = arrayLocal[1] | | +| iCoeff[9] = arrayLocal[2] | | +| iCoeff[10] = arrayLocal[3] | | +| } | | + +### 9.9.8.2 OverlapPostFilter4( ) + +The function OverlapPostFilter4( ) is specified in Table 169. + +**Table 169 – Pseudocode for function OverlapPostFilter4( )** + +| OverlapPostFilter4(iCoeff[ ]) { | Reference | +|-----------------------------------------|------------------| +| iCoeff[0] += iCoeff[3] | | +| iCoeff[1] += iCoeff[2] | | +| iCoeff[3] -= ((iCoeff[0] + 1) >> 1) | | +| iCoeff[2] -= ((iCoeff[1] + 1) >> 1) | | +| InvScale(iCoeff[0], iCoeff[3]) | 9.9.8.6 | +| InvScale(iCoeff[1], iCoeff[2]) | 9.9.8.6 | +| iCoeff[0] += ((iCoeff[3] * 3 + 4) >> 3) | | +| iCoeff[1] += ((iCoeff[2] * 3 + 4) >> 3) | | +| iCoeff[3] -= ( iCoeff[0] >> 1) | | +| iCoeff[2] -= ( iCoeff[1] >> 1) | | +| iCoeff[0] += iCoeff[3] | | +| iCoeff[1] += iCoeff[2] | | +| iCoeff[3] = -iCoeff[3] | | +| iCoeff[2] = -iCoeff[2] | | +| InvRotate(iCoeff[2], iCoeff[3]) | 9.9.8.5 | +| iCoeff[3] += ((iCoeff[0] + 1) >> 1) | | +| iCoeff[2] += ((iCoeff[1] + 1) >> 1) | | +| iCoeff[0] -= iCoeff[3] | | +| iCoeff[1] -= iCoeff[2] | | +| } | | + +### 9.9.8.3 OverlapPostFilter2x2( ) + +The function OverlapPostFilter2x2( ) is specified in Table 170. + +**Table 170 – Pseudocode for function OverlapPostFilter2x2()** + +| OverlapPostFilter2x2(iCoeff[] ) { | Reference | +|------------------------------------------|------------------| +| iCoeff[0] += iCoeff[3] | | +| iCoeff[1] += iCoeff[2] | | +| iCoeff[3] -= ((iCoeff[0] + 1) >> 1) | | +| iCoeff[2] -= ((iCoeff[1] + 1) >> 1) | | +| iCoeff[1] += ((iCoeff[0] + 2) >> 2) | | +| iCoeff[0] += ((iCoeff[1] + 1) >> 1) | | +| iCoeff[0] += (iCoeff[1] >> 5) | | +| iCoeff[0] += (iCoeff[1] >> 9) | | +| iCoeff[0] += (iCoeff[1] >> 13) | | +| iCoeff[1] += ((iCoeff[0] + 2) >> 2) | | +| iCoeff[3] += ((iCoeff[0] + 1) >> 1) | | +| iCoeff[2] += ((iCoeff[1] + 1) >> 1) | | +| iCoeff[0] -= iCoeff[3] | | +| iCoeff[1] -= iCoeff[2] | | +| } | | + +#### 9.9.8.4 OverlapPostFilter2() + +The function OverlapPostFilter2() is specified in Table 171. + +**Table 171 – Pseudocode for function OverlapPostFilter2()** + +| OverlapPostFilter2(iCoeff[] ) { | Reference | +|----------------------------------------|------------------| +| iCoeff[1] += ((iCoeff[0] + 2) >> 2) | | +| iCoeff[0] += ((iCoeff[1] + 1) >> 1) | | +| iCoeff[0] += (iCoeff[1] >> 5) | | +| iCoeff[0] += (iCoeff[1] >> 9) | | +| iCoeff[0] += (iCoeff[1] >> 13) | | +| iCoeff[1] += ((iCoeff[0] + 2) >> 2) | | +| } | | + +#### 9.9.8.5 InvRotate() + +The function InvRotate() is specified by the pseudocode in Table 172. + +**Table 172 – Pseudocode for function InvRotate()** + +| InvRotate(iCoeff[] ) { | Reference | +|-------------------------------------|------------------| +| iCoeff[0] -= ((iCoeff[1] + 1) >> 1) | | +| iCoeff[1] += ((iCoeff[0] + 1) >> 1) | | +| } | | + +#### 9.9.8.6 InvScale() + +The function InvScale() is specified by the pseudocode in Table 173. + +**Table 173 – Pseudocode for function InvScale()** + +| InvScale(iCoeff[] ) { | Reference | +|------------------------------------------|------------------| +| iCoeff[0] += iCoeff[1] | | +| iCoeff[1] = (iCoeff[0] >> 1) - iCoeff[1] | | +| iCoeff[0] += (iCoeff[1] * 3 + 0) >> 3 | | +| iCoeff[1] += (iCoeff[0] * 3 + 0) >> 4 | | +| iCoeff[1] += (iCoeff[0] >> 7) | | +| iCoeff[1] -= (iCoeff[0] >> 10) | | +| } | | + +### 9.9.8.7 T2x2hPOST() + +The function T2x2hPOST() is specified by the pseudocode in Table 174. + +**Table 174 – Pseudocode for function T2x2hPOST()** + +| T2x2hPOST(iCoeff[] ) { | Reference | +|--------------------------------------------------------|------------------| +| iCoeff[1] -= iCoeff[2] | | +| iCoeff[0] += (iCoeff[3] * 3 + 4) >> 3 | | +| iCoeff[3] -= (iCoeff[1] >> 1) | | +| iCoeff[2] = ((iCoeff[0] - iCoeff[1]) >> 1) - iCoeff[2] | | +| valT1 = iCoeff[2] | | +| iCoeff[2] = iCoeff[3] | | +| iCoeff[3] = valT1 | | +| iCoeff[0] -= iCoeff[3] | | +| iCoeff[1] += iCoeff[2] | | +| } | | + +### 9.9.8.8 InvToddoddPOST() + +The function InvToddoddPOST() is specified by the pseudocode in Table 175. + +**Table 175 – Pseudocode for function InvToddoddPOST()** + +| InvToddoddPOST(iCoeff[] ) { | Reference | +|---------------------------------------|------------------| +| iCoeff[3] += iCoeff[0] | | +| iCoeff[2] -= iCoeff[1] | | +| valT1 = iCoeff[3] >> 1 | | +| valT2 = iCoeff[2] >> 1 | | +| iCoeff[0] -= valT1 | | +| iCoeff[1] += valT2 | | +| iCoeff[0] -= (iCoeff[1] * 3 + 6) >> 3 | | +| iCoeff[1] += (iCoeff[0] * 3 + 2) >> 2 | | +| iCoeff[0] -= (iCoeff[1] * 3 + 4) >> 3 | | +| iCoeff[1] -= valT2 | | +| iCoeff[0] += valT1 | | +| iCoeff[2] += iCoeff[1] | | +| iCoeff[3] -= iCoeff[0] | | +| } | | + +## 9.10 Output formatting + +The final stage of the decoder consists of converting the sample values reconstructed in the internal format to the intended output format as specified in 9.10.2. + +### 9.10.1 Overview + +This subclause is informative: it is not an integral part of this Specification. + +First, the decoder may be required to perform upsampling to obtain an intermediate YUV444 format. Next, colour format conversion is applied to convert the internal colour formats to output formats. The colour format conversions are specified in the following. A bias is added to the sample values, to re-centre the values around the nominal value for a neutral or zero intensity representation. When the scaling mode is used, on the decoder side, the values are rounded down after colour conversion. For high numerical range formats (BD16, BD16S, BD32S and BD32F), the internal integer representations need to be converted to output representations. Finally, the values are clipped to fit the appropriate range. + +### 9.10.2 Output formatting stage + +At the completion of the transform and overlap filtering, the sample values for the image are reconstructed in an internal colour format and an internal two's complement integer representation. The output formatting stage converts the decoded image plane data into a representation specified by the OUTPUT\_CLR\_FMT and the output bit depth. In the specification of output formatting, the term INTERNAL\_CLR\_FMT refers to the corresponding syntax element of the primary image plane. + +The output formatting process is specified for the combinations of OUTPUT\_BITDEPTH and OUTPUT\_CLR\_FMT that are listed in Table 176. + +In Table 176, "+" indicates that output formatting is specified for the corresponding combinations of OUTPUT\_BIT\_DEPTH and OUTPUT\_CLR\_FMT. The combination of OUTPUT\_BIT\_DEPTH and OUTPUT\_CLR\_FMT shall not have the value corresponding to empty cells. + +**Table 176 – Conformance-specified output formatting combinations of OUTPUT\_BITDEPTH and OUTPUT\_CLR\_FMT** + +| OUTPUT_BITDEPTH | OUTPUT_CLR_FMT | | | | | | | | | +|-----------------|----------------|--------|--------|--------|-----|------|------|------------|------------| +| | YONLY | YUV420 | YUV422 | YUV444 | RGB | RGBE | CMYK | CMYKDIRECT | NCOMPONENT | +| BD1WHITE1 | + | | | | | | | | | +| BD1BLACK1 | + | | | | | | | | | +| BD5 | | | | | + | | | | | +| BD565 | | | | | + | | | | | +| BD8 | + | + | + | + | + | + | + | + | + | +| BD10 | | | + | + | + | | | | | +| BD16 | + | | + | + | + | | + | + | + | +| BD16S | + | | | + | + | | | | | +| BD16F | + | | | | + | | | | | +| BD32S | + | | | | + | | | | | +| BD32F | + | | | | + | | | | | + +The output formatting stage consists of several sub-processes that are performed as specified in Table 177. + +**Table 177 – Pseudocode for function OutputFormatting( )** + +| OutputFormatting( ) { | Reference | +|----------------------------------|------------------| +| SamplingConversion( ) | 9.10.3.1 | +| ConvertInternalToOutputClrFmt( ) | 9.10.4.1 | +| AddBias( ) | 9.10.5 | +| ComputeScaling( ) | 9.10.6 | +| PostscalingProcess( ) | 9.10.7.1 | +| ClippingAndPackingStage( ) | 9.10.8.1 | +| } | | + +## 9.10.3 Sampling conversion + +### 9.10.3.1 General + +The sampling conversion process is specified in Table 178. + +The combinations of INTERNAL\_CLR\_FMT and OUTPUT\_CLR\_FMT for which sampling conversions are specified for conformance purposes are specified in Table 179. In Table 179, "+" indicates that no sampling conversion is required. It is a requirement of codestream conformance to this Specification that the combination of INTERNAL\_CLR\_FMT and OUTPUT\_CLR\_FMT shall not have a value corresponding to any empty cell in Table 179. + +In the illustrated case in Table 178 in which upsampling is specified both vertically and horizontally for INTERNAL\_CLR\_FMT equal to YUV420, the upsampling process to be performed by the decoder shall produce an array of two-dimensionally upsampled samples at the index values for which such samples are produced as specified in Table 178. However, decoders may use alternative upsampling methods (different from that specified in Table 178) – the actual filtering method used to produce the values of the entries in the upsampled array is outside the scope of this Specification. The particular filtering method specified in Table 178 is an example of how such upsampled array values may be produced. For example, upsampling may be applied both vertically and horizontally as a single process or the relative ordering of the vertical and horizontal upsampling may be switched. + +NOTE – When TILING\_FLAG is equal to TRUE and the transform processing does not cross tile boundaries (due either to HARD\_TILING\_FLAG being equal to TRUE or OVERLAP\_MODE being equal to 0), the example upsampling method illustrated in Table 178 for cases with INTERNAL\_CLR\_FMT equal to YUV422 or YUV420 will produce an upsampled image in which the output samples next to tile boundaries may be affected by the values of decoded samples in other tiles. For many applications, it may be desirable to instead design the upsampling process to be performed separately within each tile in order to avoid this cross-tile dependency. + +**Table 178 – Pseudocode for function SamplingConversion( )** + +| SamplingConversion( ) { | Reference | +|--------------------------------------------------------------------------------------------------------------------------------|------------------| +| if(((INTERNAL_CLR_FMT == YUV422) (INTERNAL_CLR_FMT == YUV420)) && ((OUTPUT_CLR_FMT == YUV444) (OUTPUT_CLR_FMT == RGB)) { | | +| if (INTERNAL_CLR_FMT == YUV420) | | +| Upsample( ) in the vertical direction | 9.10.3.2 | +| if((INTERNAL_CLR_FMT == YUV422) (INTERNAL_CLR_FMT == YUV420)) | | +| Upsample( ) in the horizontal direction | 9.10.3.2 | +| } | | +| } | | + +**Table 179 – Conformance-specified sampling conversions** + +| OUTPUT_CLR_FMT | INTERNAL CLR_FMT | | | | | | +|-------------------------------------------------------------------------------------------|------------------|----------------------------------------------------------------|--------------------------------------------------|--------|------|------------| +| | YONLY | YUV420 | YUV422 | YUV444 | YUVK | NCOMPONENT | +| YONLY | + | | | | | | +| YUV420 | | + | | | | | +| YUV422 | | | + | | | | +| YUV444 | + | Upsample( )
in the vertical
and horizontal
directions | Upsample( )
in the
horizontal
direction | + | | | +| RGB with
OUTPUT_BITDEPTH
equal to BD5, BD565,
BD8, BD10, BD16,
BD16S or BD32S | + | Upsample( )
in the vertical
and horizontal
directions | Upsample( )
in the
horizontal
direction | + | | | +| RGB with
OUTPUT_BITDEPTH
equal to BD16F or
BD32F | | | | + | | | +| RGBE | | | | + | | | +| CMYK | | | | | + | | +| CMYKDIRECT | | | | | + | | +| NCOMPONENT | | | | | | + | + +### 9.10.3.2 Upsample( ) + +In the chroma upsampling function, for the chroma component $i$ ( $1 \leq i < \text{NumComponents}$ ), let $i\text{OriArray}[]$ be the original sample array before upsampling, and $i\text{IntArray}[]$ be the upsampled array. If upsampling is performed in the horizontal direction, $i\text{OriArray}[]$ is one input sample row of length $\text{ExtendedWidth}[i]$ and $i\text{IntArray}[]$ is one output sample row of length $\text{ExtendedWidth}[0]$ , and the variable $i\text{OriLength}$ is set equal to $\text{ExtendedWidth}[i]$ . Otherwise, $i\text{OriArray}[]$ is one input sample column of length $\text{ExtendedHeight}[i]$ and $i\text{IntArray}[]$ is one output sample column of length $\text{ExtendedHeight}[0]$ , and $i\text{OriLength}$ is set equal to $\text{ExtendedHeight}[i]$ . + +The upsampling process to be performed by the decoder shall produce an array of upsampled samples at the index values for which such samples are produced as specified in Table 180. However, decoders may use alternative upsampling methods (different from that specified in Table 180) – the actual filtering method used to produce the values of the entries in the upsampled array is outside the scope of this Specification. The particular filtering method specified in Table 180 is an example of how such upsampled array values may be produced. For example, a different type of filtering or a different number of taps may be used during the upsampling process than the two-tap filtering specified in Table 180. + +**Table 180 – Pseudocode for function Upsample( )** + +| Upsample( ) { | Reference | +|------------------------------------------------------------------------------------------------------------------------------------------------|------------------| +| for ( $k = 0$ ; $k < i\text{OriLength}$ ; $k++$ ) { | | +| $i\text{IntArray}[2 * k] = ((iH[2] * i\text{OriArray}[\text{Max}(0, k - 1)] + iH[3] * i\text{OriArray}[k] + 4) \gg 3)$ | | +| $i\text{IntArray}[2 * k + 1] = ((iH[0] * i\text{OriArray}[k] + iH[1] * i\text{OriArray}[\text{Min}(i\text{OriLength} - 1, k + 1)] + 4) \gg 3)$ | | +| } | | +| } | | + +The values of the filter coefficients iH[0], iH[1], iH[2], iH[3] for the chroma positions are specified in Table 181 as a function of the variable chromaCentering. If Upsample( ) is applied in the horizontal direction, chromaCentering is set equal to CHROMA\_CENTERING\_X; otherwise, it is set equal to CHROMA\_CENTERING\_Y. + +**Table 181 – Upsampling filter coefficient for different chroma positions** + +| chromaCentering | iH[0] | iH[1] | iH[2] | iH[3] | +|-----------------|-------|-------|-------|-------| +| 0 | 4 | 4 | 0 | 8 | +| 1 | 5 | 3 | 1 | 7 | +| 2 | 6 | 2 | 2 | 6 | +| 3 | 7 | 1 | 3 | 5 | +| 4 | 8 | 0 | 4 | 4 | + +## 9.10.4 Conversion from INTERNAL\_CLR\_FMT to OUTPUT\_CLR\_FMT + +### 9.10.4.1 Overview + +The conversion process proceeds as specified in Table 182. + +**Table 182 – Pseudocode for function ConvertInternalToOutputClrFmt( )** + +| ConvertInternalToOutputClrFmt( ) { | Reference | +|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------| +| if ((INTERNAL_CLR_FMT == YUVK) &&
(OUTPUT_CLR_FMT == CMYK)) | | +| InvColorFmtConvert3( ) | 9.10.4.4 | +| else if ((INTERNAL_CLR_FMT == YUVK) &&
(OUTPUT_CLR_FMT == CMYKDIRECT)) | | +| InvColorFmtConvert4( ) | 9.10.4.5 | +| else if ((INTERNAL_CLR_FMT == YONLY) &&
(OUTPUT_CLR_FMT == RGB)) | | +| InvColorFmtConvert1( ) | 9.10.4.2 | +| else if (((INTERNAL_CLR_FMT == YUV444)
(INTERNAL_CLR_FMT == YUV422)
(INTERNAL_CLR_FMT == YUV420)) &&
((OUTPUT_CLR_FMT == RGB) (OUTPUT_CLR_FMT == RGBE))) | | +| InvColorFmtConvert2( ) | 9.10.4.3 | +| else if ((INTERNAL_CLR_FMT == YONLY) &&
((OUTPUT_CLR_FMT == YUV444) (OUTPUT_CLR_FMT == YUV422)
(OUTPUT_CLR_FMT == YUV420))) { | | +| if (OUTPUT_CLR_FMT == YUV420) | | +| chromaHeight = ExtendedHeight[0] / 2 | | +| else | | +| chromaHeight = ExtendedHeight[0] | | +| if ((OUTPUT_CLR_FMT == YUV422) (OUTPUT_CLR_FMT == YUV420)) | | +| chromaWidth = ExtendedWidth[0] / 2 | | +| else | | +| chromaWidth = ExtendedWidth[0] | | +| for (i = 1; i < 3; i++) | | +| for (y = 0; y < chromaHeight; y++) | | +| for (x = 0; x < chromaWidth; x++) | | +| ImagePlane[i][x][y] = 0 /* Ensure that chroma is inferred as zero */ | | +| } | | +| } | | + +The combinations of INTERNAL\_CLR\_FMT and OUTPUT\_CLR\_FMT for which colour format conversions are specified for conformance purposes are specified in Table 183. In Table 183, "+" indicates that no colour format conversion is required. For cases that require colour format conversion, the function name for the conversion process is specified in the table cell. It is a requirement of codestream conformance to this Specification that the combination of INTERNAL\_CLR\_FMT and OUTPUT\_CLR\_FMT shall not have a value corresponding to any empty cell in Table 183. + +**Table 183 – Conformance-specified colour format conversions** + +| OUTPUT_CLR_FMT | INTERNAL_CLR_FMT | | | | | | +|-------------------------------------------------------------------------------------------|----------------------------|----------------------------|----------------------------|----------------------------|----------------------------|------------| +| | YONLY | YUV420 | YUV422 | YUV444 | YUVK | NCOMPONENT | +| YONLY | + | | | | | | +| YUV420 | | + | | | | | +| YUV422 | | | + | | | | +| YUV444 | + | + | + | + | | | +| RGB with
OUTPUT_BITDEPTH
equal to BD5, BD565,
BD8, BD10, BD16,
BD16S or BD32S | InvColorFmt
Convert1( ) | InvColorFmt
Convert2( ) | InvColorFmt
Convert2( ) | InvColorFmt
Convert2( ) | | | +| RGB with
OUTPUT_BITDEPTH
equal to BD16F or
BD32F | | | | InvColorFmt
Convert2( ) | | | +| RGBE | | | | InvColorFmt
Convert2( ) | | | +| CMYK | | | | | InvColorFmt
Convert3( ) | | +| CMYKDIRECT | | | | | InvColorFmt
Convert4( ) | | +| NCOMPONENT | | | | | | + | + +The pseudocode functions InvColorFmtConvert1(), InvColorFmtConvert2(), InvColorFmtConvert3(), and InvColorFmtConvert4() that are referred to in Table 183 are specified in 9.10.4.2, 9.10.4.3, 9.10.4.4 and 9.10.4.5, respectively. + +#### 9.10.4.2 InvColorFmtConvert1() + +The operations in InvColorFmtConvert1() are specified in Table 184. + +**Table 184 – Pseudocode for function InvColorFmtConvert1()** + +| InvColorFmtConvert1() { | Reference | +|-------------------------------------------------------|------------------| +| for (y = 0; y < ExtendedHeight[0]; y++) | | +| for (x = 0; x < ExtendedWidth[0]; x++) { | | +| /* ImagePlane[0][x][y] G = Y */ | | +| ImagePlane[1][x][y] = ImagePlane[0][x][y] /* R = Y */ | | +| ImagePlane[2][x][y] = ImagePlane[0][x][y] /* B = Y */ | | +| } | | +| } | | + +#### 9.10.4.3 InvColorFmtConvert2() + +The operations in InvColorFmtConvert2() are specified in Table 185. + +**Table 185 – Pseudocode for function InvColorFmtConvert2()** + +| InvColorFmtConvert2( ) { | Reference | +|----------------------------------------------------------------------------------------------------------------------------|------------------| +| for (y = 0; y < ExtendedHeight[0]; y++) | | +| for (x = 0; x < ExtendedWidth[0]; x++) { | | +| tempT = –ImagePlane[1][x][y]
/* t = –U */ | | +| arrayOut[1] = ImagePlane[0][x][y] – Floor(tempT ÷ 2)
/* G = Y – Floor(t ÷ 2) */ | | +| arrayOut[0] = tempT + arrayOut[1] – Ceiling(ImagePlane[2][x][y] ÷ 2)
/* R = t + G – Ceiling(V ÷ 2) */ | | +| arrayOut[2] = ImagePlane[2][x][y] + arrayOut[0]
/* B = V + R */ | | +| if ((OUTPUT_BITDEPTH == BD5 OUTPUT_BITDEPTH == BD565
OUTPUT_BITDEPTH == BD10) &&
!RED_BLUE_NOT_SWAPPED_FLAG) { | | +| tempT = arrayOut[0] | | +| arrayOut[0] = arrayOut[2] | | +| arrayOut[2] = tempT | | +| } | | +| for (i = 0; i < 3; i++) | | +| ImagePlane[i][x][y] = arrayOut[i] | | +| } | | +| } | | + +#### 9.10.4.4 InvColorFmtConvert3() + +The operations in InvColorFmtConvert3( ) are specified in Table 186. + +**Table 186 – Pseudocode for function InvColorFmtConvert3()** + +| InvColorFmtConvert3( ) { | Reference | +|--------------------------------------------------------------------------------------------------------------------|------------------| +| for (y = 0; y < ExtendedHeight[0]; y++) | | +| for (x = 0; x < ExtendedWidth[0]; x++) { | | +| arrayOut[3] = ImagePlane[3][x][y] + Floor(ImagePlane[0][x][y] ÷ 2)
/* k = K + Floor(Y ÷ 2) */ | | +| arrayOut[1] = arrayOut[3] – ImagePlane[0][x][y] –
Floor(ImagePlane[1][x][y] ÷ 2) /* m = k – Y – Floor(U ÷ 2) */ | | +| arrayOut[0] = ImagePlane[1][x][y] + arrayOut[1] +
Floor(ImagePlane[2][x][y] ÷ 2) /* c = U + m + Floor(V ÷ 2) */ | | +| arrayOut[2] = arrayOut[0] – ImagePlane[2][x][y]
/* y = c – V */ | | +| for (i = 0; i < 4; i++) | | +| ImagePlane[i][x][y] = arrayOut[i] | | +| } | | +| } | | + +#### 9.10.4.5 InvColorFmtConvert4() + +The operations in InvColorFmtConvert4( ) are specified in Table 187. + +**Table 187 – Pseudocode for function InvColorFmtConvert4()** + +| InvColorFmtConvert4( ) { | Reference | +|-----------------------------------------------|------------------| +| for (y = 0; y < ExtendedHeight[0]; y++) | | +| for (x = 0; x < ExtendedWidth[0]; x++) { | | +| arrayOut[3] = ImagePlane[0][x][y] /* k = Y */ | | +| arrayOut[1] = ImagePlane[2][x][y] /* m = V */ | | +| arrayOut[0] = ImagePlane[1][x][y] /* c = U */ | | +| arrayOut[2] = ImagePlane[3][x][y] /* y = K */ | | +| for (i = 0; i < 4; i++) | | +| ImagePlane[i][x][y] = arrayOut[i] | | +| } | | +| } | | + +### 9.10.5 AddBias() + +The function AddBias() specified in Table 188 performs the computation and addition of bias to the sample values. + +**Table 188 – Pseudocode for function AddBias()** + +| AddBias() { | Reference | +|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------| +| if (SCALED_FLAG) | | +| iScale = 3 | | +| else | | +| iScale = 0 | | +| if (OUTPUT_BITDEPTH == BD5) | | +| iBias = (1 << 4) | | +| else if (OUTPUT_BITDEPTH == BD565) | | +| iBias = (1 << 5) | | +| else if (OUTPUT_BITDEPTH == BD8) | | +| iBias = (1 << 7) | | +| else if (OUTPUT_BITDEPTH == BD10) | | +| iBias = (1 << 9) | | +| else if (OUTPUT_BITDEPTH == BD16) | | +| iBias = (1 << 15) | | +| else | | +| iBias = 0 | | +| if ((OUTPUT_BITDEPTH == BD16) (OUTPUT_BITDEPTH == BD16S)
(OUTPUT_BITDEPTH == BD32S)) | | +| iBias = (iBias >> SHIFT_BITS) | | +| if ((OUTPUT_CLR_FMT == RGB) (OUTPUT_CLR_FMT == YUV444)
(OUTPUT_CLR_FMT == YUV422) (OUTPUT_CLR_FMT == YUV420)
(OUTPUT_CLR_FMT == YONLY) (OUTPUT_CLR_FMT == NCOMPONENT)
(OUTPUT_CLR_FMT == CMYKDIRECT)) { | | +| if ((OUTPUT_CLR_FMT == RGB) (OUTPUT_CLR_FMT == YUV444)
(OUTPUT_CLR_FMT == YUV422) (OUTPUT_CLR_FMT == YUV420)) | | +| outputComponents = 3 | | +| else | | +| outputComponents = NumComponents | | +| for (i = 0; i < outputComponents; i++) { | | +| if ((i > 0) && (OUTPUT_CLR_FMT == YUV420)) | | +| outputHeight = ExtendedHeight[0] / 2 | | +| else | | +| outputHeight = ExtendedHeight[0] | | +| if ((i > 0) &&
((OUTPUT_CLR_FMT == YUV422) (OUTPUT_CLR_FMT == YUV420))) | | +| outputWidth = ExtendedWidth[0] / 2 | | +| else | | +| outputWidth = ExtendedWidth[0] | | +| for (y = 0; y < outputHeight; y++) | | +| for (x = 0; x < outputWidth; x++) | | +| ImagePlane[i][x][y] += (iBias << iScale) | | +| } | | +| } else if (OUTPUT_CLR_FMT == CMYK) { | | +| for (i = 0; i < 3; i++) | | +| for (y = 0; y < ExtendedHeight[0]; y++) | | +| for (x = 0; x < ExtendedWidth[0]; x++) | | +| ImagePlane[i][x][y] += ((iBias >> 1) << iScale) /* c, m, y */ | | +| for (y = 0; y < ExtendedHeight[0]; y++) | | +| for (x = 0; x < ExtendedWidth[0]; x++) | | +| ImagePlane[3][x][y] -= ((iBias >> 1) << iScale) /* k */ | | +| } | | +| } | | +| } | | + +### 9.10.6 ComputeScaling() + +The function ComputeScaling() specified in Table 189 performs the computation of the scaling factor iScale, and the rounding factor iRoundingFactor, and modifies sample values based on these two factors. + +**Table 189 – Pseudocode for function ComputeScaling()** + +| ComputeScaling() { | Reference | +|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------| +| iScale = 0 | | +| iRoundingFactor = 0 | | +| if (SCALED_FLAG) { | | +| iScale = 3 | | +| if ((OUTPUT_BITDEPTH == BD5) (OUTPUT_BITDEPTH == BD565)
(OUTPUT_BITDEPTH == BD8) (OUTPUT_BITDEPTH == BD10)
(OUTPUT_BITDEPTH == BD16S) (OUTPUT_BITDEPTH == BD16F)
(OUTPUT_BITDEPTH == BD32S) (OUTPUT_BITDEPTH == BD32F)) | | +| iRoundingFactor = 3 | | +| else if ((OUTPUT_BITDEPTH == BD1WHITE1)
(OUTPUT_BITDEPTH == BD1BLACK1) (OUTPUT_BITDEPTH == BD16)) | | +| iRoundingFactor = 4 | | +| } | | +| if ((OUTPUT_CLR_FMT == RGB) (OUTPUT_CLR_FMT == RGBE)
(OUTPUT_CLR_FMT == YUV444) (OUTPUT_CLR_FMT == YUV422)
(OUTPUT_CLR_FMT == YUV420)) | | +| outputComponents = 3 | | +| else | | +| outputComponents = NumComponents | | +| for (i = 0; i < outputComponents; i++) { | | +| if ((i > 0) && (OUTPUT_CLR_FMT == YUV420)) | | +| outputHeight = ExtendedHeight[0] / 2 | | +| else | | +| outputHeight = ExtendedHeight[0] | | +| if ((i > 0) &&
((OUTPUT_CLR_FMT == YUV422) (OUTPUT_CLR_FMT == YUV420))) | | +| outputWidth = ExtendedWidth[0] / 2 | | +| else | | +| outputWidth = ExtendedWidth[0] | | +| if ((OUTPUT_BITDEPTH == BD565) && (i != 1)) | | +| jScale = iScale + 1 | | +| else | | +| jScale = iScale | | +| for (y = 0; y < outputHeight; y++) | | +| for (x = 0; x < outputWidth; x++) | | +| ImagePlane[i][x][y] = ((ImagePlane[i][x][y] + iRoundingFactor) >> jScale) | | +| } | | +| } | | + +9.10.7 Postscaling process + +9.10.7.1 Overview + +The function PostscalingProcess( ) is specified in Table 190. + +Table 190 – Pseudocode for function PostscalingProcess( ) + +| PostscalingProcess( ) { | Reference | +|----------------------------------------------------------------------------------------|-----------| +| if (OUTPUT_CLR_FMT == RGBE) | | +| for (y = 0; y < ExtendedHeight[0]; y++) | | +| for (x = 0; x < ExtendedWidth[0]; x++) { | | +| for (k = 0; k < 3; k++) | | +| localArrayIn[k] = ImagePlane[k][x][y] | | +| PostScalingF2(localArrayOut[ ], localArrayIn[ ]) /* Produces 4 outputs for 3 inputs */ | 9.10.7.4 | +| for (k = 0; k < 4; k++) | | +| ImagePlane[k][x][y] = localArrayOut[k] | | +| } | | +| else { | | +| if ((OUTPUT_CLR_FMT == RGB) (OUTPUT_CLR_FMT == YUV444) | | +| (OUTPUT_CLR_FMT == YUV422) (OUTPUT_CLR_FMT == YUV420)) | | +| outputComponents = 3 | | +| else | | +| outputComponents = NumComponents | | +| for (i = 0; i < outputComponents; i++) { | | +| if ((i > 0) && (OUTPUT_CLR_FMT == YUV420)) | | +| outputHeight = ExtendedHeight[0] / 2 | | +| else | | +| outputHeight = ExtendedHeight[0] | | +| if ((i > 0) && | | +| ((OUTPUT_CLR_FMT == YUV422) (OUTPUT_CLR_FMT == YUV420))) | | +| outputWidth = ExtendedWidth[0] / 2 | | +| else | | +| outputWidth = ExtendedWidth[0] | | +| if ((OUTPUT_BITDEPTH == BD16) (OUTPUT_BITDEPTH == BD16S) | | +| (OUTPUT_BITDEPTH == BD32S)) | | +| for (y = 0; y < outputHeight; y++) | | +| for (x = 0; x < outputWidth; x++) | | +| ImagePlane[i][x][y] = PostScalingInt(ImagePlane[i][x][y]) | 9.10.7.2 | +| else if ((OUTPUT_BITDEPTH == BD32F) (OUTPUT_BITDEPTH == BD16F)) | | +| for (y = 0; y < outputHeight; y++) | | +| for (x = 0; x < outputWidth; x++) | | +| ImagePlane[i][x][y] = PostScalingFl(ImagePlane[i][x][y]) | 9.10.7.3 | +| } | | +| } | | +| } | | + +9.10.7.2 PostScalingInt( ) + +The sample values are left-shifted by the amount determined by SHIFT\_BITS. For input value inX, the output shifted value outX is determined as specified in Table 191. + +Table 191 – Pseudocode for function PostScalingInt( ) + +| PostScalingInt(inX) { | Reference | +|--------------------------|-----------| +| outX = inX << SHIFT_BITS | | +| return outX | | +| } | | + +NOTE – In this manner, the output is moved from a 27-bit or 24-bit nominal range scaling to the range scaling specified for image reconstruction. The 27-bit range scaling applies when the data is scaled, and the 24-bit range scaling applies when the data is unscaled. + +### 9.10.7.3 PostScalingFl( ) + +When OUTPUT\_BITDEPTH is equal to BD32F or BD16F, the integer sample value iX is converted to a value fV that can be interpreted as a floating point representation. + +The PostScalingFl( ) process computes the value fV as specified in Table 192. + +**Table 192 – Pseudocode for function PostScalingFl( )** + +| PostScalingFl(iX) { | Reference | +|--------------------------------------------------------------------|------------------| +| if (iX < 0) | | +| iS = 1 | | +| else | | +| iS = 0 | | +| if (OUTPUT_BITDEPTH == BD16F) { | | +| iEM = Min(Abs(iX), 32767) | | +| fV = ((iS << 15) iEM) /* Concatenate these fields*/ | | +| } else { /* OUTPUT_BITDEPTH == BD32F */ | | +| iX = Abs(iX) | | +| iE = (iX >> LEN_MANTISSA) | | +| iM = ((iX & ((1 << LEN_MANTISSA) - 1)) (1 << LEN_MANTISSA)) | | +| if (iE == 0) { | | +| iM ^= (1 << LEN_MANTISSA) | | +| iE = 1 | | +| } | | +| iE = iE - EXP_BIAS + 127 | | +| while ((iM < (1 << LEN_MANTISSA)) && (iE > 1) && (iM > 0)) { | | +| iE -= 1 | | +| iM <<= 1 | | +| } | | +| if (iM < (1 << LEN_MANTISSA)) | | +| iE = 0 | | +| else | | +| iM ^= (1 << LEN_MANTISSA) | | +| iM <<= (23 - LEN_MANTISSA) | | +| fV = ((iS << 31) (iE << 23) iM) /* Concatenate these fields */ | | +| } | | +| return fV | | +| } | | + +### 9.10.7.4 PostScalingF2( ) + +When OUTPUT\_CLR\_FMT is equal to RGBE, the three integer sample values of array arrayIn[ ] (R, G, and B) are converted to an array arrayOut[ ] of four integer values forming the RGBE representation (Rrgbe, Grgbe, Brgbe and Ergbe). The function PostScalingF2( ) specified in Table 193 performs the conversion. + +**Table 193 – Pseudocode for function PostScalingF2( )** + +| PostScalingF2(arrayOut[ ], arrayIn[ ] ) { | Reference | +|--------------------------------------------------|------------------| +| /* arrayIn[ ] = {R, G, B} */ | | +| /* arrayOut[ ] = {Rrgbe, Grgbe, Brgbe, Ergbe} */ | | +| if (arrayIn[0] <= 0) { | | +| arrayOut[0] = 0 | | +| iEr = 0 | | +| } else if ((arrayIn[0] >> 7) > 1) { | | +| arrayOut[0] = (arrayIn[0] & 0x7F) + 128 | | +| iEr = (arrayIn[0] >> 7) | | +| } else { | | +| arrayOut[0] = arrayIn[0] | | +| iEr = 1 | | +| } | | +| if (arrayIn[1] <= 0) { | | +| arrayOut[1] = 0 | | +| iEg = 0 | | + +| PostScalingF2(arrayOut[ ], arrayIn[ ]) { | Reference | +|-------------------------------------------------------|------------------| +| } else if ((arrayIn[1] >> 7) > 1) { | | +| arrayOut[1] = (arrayIn[1] & 0x7F) + 128 | | +| iEg = (arrayIn[1] >> 7) | | +| } else { | | +| arrayOut[1] = arrayIn[1] | | +| iEg = 1 | | +| } | | +| if (arrayIn[2] <= 0) { | | +| arrayOut[2] = 0 | | +| iEb = 0 | | +| } else if ((arrayIn[2] >> 7) > 1) { | | +| arrayOut[2] = (arrayIn[2] & 0x7F) + 128 | | +| iEb = (arrayIn[2] >> 7) | | +| } else { | | +| arrayOut[2] = arrayIn[2] | | +| iEb = 1 | | +| } | | +| arrayOut[3] = Max(iEr, Max(iEg, iEb)) | | +| if (arrayOut[3] > iEr) { | | +| iShift = (arrayOut[3] - iEr) | | +| arrayOut[0] = ((2 * arrayOut[0] + 1) >> (iShift + 1)) | | +| } | | +| if (arrayOut[3] > iEg) { | | +| iShift = (arrayOut[3] - iEg) | | +| arrayOut[1] = ((2 * arrayOut[1] + 1) >> (iShift + 1)) | | +| } | | +| if (arrayOut[3] > iEb) { | | +| iShift = (arrayOut[3] - iEb) | | +| arrayOut[2] = ((2 * arrayOut[2] + 1) >> (iShift + 1)) | | +| } | | +| } | | + +## 9.10.8 Clipping and packing stage + +### 9.10.8.1 General + +The ClippingAndPackingStage() process by which clipping, packing, and windowing are performed is specified in Table 194. The clipping ensures that the sample values are constrained to the appropriate range. The packing process packs multiple samples into single variables for some values of OUTPUT\_BITDEPTH. The windowing process uses the LEFT\_MARGIN, TOP\_MARGIN, WIDTH\_MINUS1 and HEIGHT\_MINUS1 syntax elements to discard the data outside of the image area that is to be output. + +**Table 194 – Pseudocode for function ClippingAndPackingStage( )** + +| ClippingAndPackingStage( ) { | Reference | +|---------------------------------------------------------------------------------------------------------------------------------------------|------------------| +| if((OUTPUT_CLR_FMT == RGB) &&
((OUTPUT_BITDEPTH == BD5) (OUTPUT_BITDEPTH == BD565)
(OUTPUT_BITDEPTH == BD10))) /* Packed RGB */ | | +| outputArrays = 1 | | +| else if ((OUTPUT_CLR_FMT == RGB) (OUTPUT_CLR_FMT == YUV444)
(OUTPUT_CLR_FMT == YUV422) (OUTPUT_CLR_FMT == YUV420)) | | +| outputArrays = 3 | | +| else if (OUTPUT_CLR_FMT == RGBE) | | +| outputArrays = 4 | | +| else | | +| outputArrays = NumComponents | | +| for (i = 0; i < outputArrays; i++) { | | +| if ((i > 0) && (OUTPUT_CLR_FMT == YUV420)) { | | +| outputHeight = (HEIGHT_MINUS1 + 1) / 2 | | +| n = TOP_MARGIN / 2 | | +| } else { | | +| outputHeight = HEIGHT_MINUS1 + 1 | | +| n = TOP_MARGIN | | +| } | | + +| ClippingAndPackingStage() { | Reference | +|----------------------------------------------------------------------------------------------------------------------------------|-----------| +| if ((i > 0) &&
((OUTPUT_CLR_FMT == YUV422) (OUTPUT_CLR_FMT == YUV420))) { | | +| outputWidth = (WIDTH_MINUS1 + 1) / 2 | | +| m = LEFT_MARGIN / 2 | | +| } else { | | +| outputWidth = WIDTH_MINUS1 + 1 | | +| m = LEFT_MARGIN | | +| } | | +| if ((OUTPUT_BITDEPTH == BD8) (OUTPUT_BITDEPTH == BD16)
(OUTPUT_BITDEPTH == BD16S)) | | +| for (y = 0; y < outputHeight; y++) | | +| for (x = 0; x < outputWidth; x++) | | +| ImagePlane[i][x][y] = ClippingBasic(ImagePlane[i][x + m][y + n]) | 9.10.8.2 | +| else if (OUTPUT_BITDEPTH == BD565) | | +| for (y = 0; y < outputHeight; y++) | | +| for (x = 0; x < outputWidth; x++) | | +| ImagePlane[i][x][y] = ClipAndPackBD565(ImagePlane[0][x + m][y + n],
ImagePlane[1][x + m][y + n], ImagePlane[2][x + m][y + n]) | 9.10.8.3 | +| else if (OUTPUT_BITDEPTH == BD5) | | +| for (y = 0; y < outputHeight; y++) | | +| for (x = 0; x < outputWidth; x++) | | +| ImagePlane[i][x][y] = ClipAndPackBD5(ImagePlane[0][x + m][y + n],
ImagePlane[1][x + m][y + n], ImagePlane[2][x + m][y + n]) | 9.10.8.4 | +| else if (OUTPUT_BITDEPTH == BD10) | | +| if (OUTPUT_CLR_FMT == RGB) | | +| for (y = 0; y < outputHeight; y++) | | +| for (x = 0; x < outputWidth; x++) | | +| ImagePlane[i][x][y] = ClipAndPackBD10(ImagePlane[0][x + m][y + n],
ImagePlane[1][x + m][y + n], ImagePlane[2][x + m][y + n]) | 9.10.8.5 | +| else | | +| for (y = 0; y < outputHeight; y++) | | +| for (x = 0; x < outputWidth; x++) | | +| ImagePlane[i][x][y] = ClipAndPackBD10(ImagePlane[i][x + m][y + n], 0, 0) | 9.10.8.5 | +| else if ((OUTPUT_BITDEPTH == BD1WHITE1) (OUTPUT_BITDEPTH == BD1BLACK1)) | | +| for (y = 0; y < outputHeight; y++) | | +| for (x = 0; x < outputWidth; x+=8) { /* Up to 8 samples are packed into each output byte */ | | +| pNum = Min(outputWidth - x, 8) /* Number of values to pack into current output byte */ | | +| for (p = pNum; m < 8; p++) /* Prevent junk beyond valid image data in array */ | | +| valList[p] = 0 /* Actual value does not matter in this region */ | | +| for (p = 0; p < pNum; p++) | | +| valList[p] = ImagePlane[i][x + m + p][y + n] | | +| ImagePlane[i][x >> 3][y] = ClipAndPackBD1BorW(valList) | 9.10.8.6 | +| } | | +| else /* OUTPUT_BITDEPTH equal to BD16F, BD32F, or BD32S */ | | +| for (y = 0; y < outputHeight; y++) | | +| for (x = 0; x < outputWidth; x++) | | +| ImagePlane[i][x][y] = ImagePlane[i][x + m][y + n] | | +| } | | +| } | | + +### 9.10.8.2 ClippingBasic() + +The pseudocode function ClippingBasic() is specified in Table 195. + +**Table 195 – Pseudocode for function ClippingBasic()** + +| | +|---------------------------------------| +| ClippingBasic(iSample) { | +| if (OUTPUT_BITDEPTH == BD8) { | +| iLow = 0 | +| iHigh = 255 | +| } else if (OUTPUT_BITDEPTH == BD16) { | +| iLow = 0 | +| iHigh = 65535 | + +| | +|--------------------------------------------------------------------------------| +| ClippingBasic(iSample) { | +| } else if (OUTPUT_BITDEPTH == BD16S) { | +| iLow = -32768 | +| iHigh = 32767 | +| } | +| iResult = Clip(iSample, iLow, iHigh) /* Clip within the range iLow to iHigh */ | +| return iResult | +| } | + +### 9.10.8.3 ClipAndPackBD565() + +The pseudocode function ClipAndPackBD565( ) is specified in Table 196. + +**Table 196 – Pseudocode for function ClipAndPackBD565()** + +| | +|---------------------------------------| +| ClipAndPackBD565(i0, i1, i2) { | +| iLow = 0 | +| iHigh = 31 | +| i0 = Clip(i0, iLow, iHigh) | +| i2 = Clip(i2, iLow, iHigh) | +| iLow = 0 | +| iHigh = 63 | +| i1 = Clip(i1, iLow, iHigh) | +| iResult = i0 + (i1 << 5) + (i2 << 11) | +| return iResult | +| } | + +### 9.10.8.4 ClipAndPackBD5() + +The pseudocode function ClipAndPackBD5( ) is specified in Table 197. + +**Table 197 – Pseudocode for function ClipAndPackBD5()** + +| | +|---------------------------------------| +| ClipAndPackBD5(i0, i1, i2) { | +| iLow = 0 | +| iHigh = 31 | +| i0 = Clip(i0, iLow, iHigh) | +| i1 = Clip(i1, iLow, iHigh) | +| i2 = Clip(i2, iLow, iHigh) | +| iResult = i0 + (i1 << 5) + (i2 << 10) | +| return iResult | +| } | + +### 9.10.8.5 ClipAndPackBD10() + +The pseudocode function ClipAndPackBD10( ) is specified in Table 198. + +**Table 198 – Pseudocode for function ClipAndPackBD10()** + +| | +|--------------------------------------------------------| +| ClipAndPackBD10(iSample0, iSample1, iSample2) { | +| iLow = 0 | +| iHigh = 1023 | +| if (OUTPUT_CLR_FMT == RGB) { | +| i0 = Clip(iSample0, iLow, iHigh) | +| i1 = Clip(iSample1, iLow, iHigh) | +| i2 = Clip(iSample2, iLow, iHigh) | +| iResult = i0 + (i1 << 10) + (i2 << 20) | +| } else | +| iResult = Clip(iSample0, iLow, iHigh) | +| return iResult | +| } | + +### 9.10.8.6 ClipAndPackBD1BorW() + +The pseudocode function ClipAndPackBD1BorW( ) is specified in Table 199. + +**Table 199 – Pseudocode for function ClipAndPackBD1BorW()** + +| | +|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| ClipAndPackBD1BorW(valList) { | +| /* valList[0] holds the value associated with the first sample value in the scan order, and
valList[7] holds the value associated with the last sample value in the scan order */ | +| valList[0] = Clip(valList[0], 0, 1) | +| valList[1] = Clip(valList[1], 0, 1) | +| valList[2] = Clip(valList[2], 0, 1) | +| valList[3] = Clip(valList[3], 0, 1) | +| valList[4] = Clip(valList[4], 0, 1) | +| valList[5] = Clip(valList[5], 0, 1) | +| valList[6] = Clip(valList[6], 0, 1) | +| valList[7] = Clip(valList[7], 0, 1) | +| if (OUTPUT_BITDEPTH == BD1BLACK1) | +| iResult = (1 - valList[7]) + ((1 - valList[6]) << 1) + ((1 - valList[5]) << 2) +
((1 - valList[4]) << 3) + ((1 - valList[3]) << 4) + ((1 - valList[2]) << 5) +
((1 - valList[1]) << 6) + ((1 - valList[0]) << 7) | +| else /* OUTPUT_BITDEPTH == BD1WHITE1 */ | +| iResult = valList[7] + (valList[6] << 1) + (valList[5] << 2) +
(valList[4] << 3) + (valList[3] << 4) + (valList[2] << 5) +
(valList[1] << 6) + (valList[0] << 7) | +| return iResult | +| } | + +## Annex A + +### Tag-based file format + +(This annex forms an integral part of this Recommendation | International Standard.) + +#### A.1 General + +This annex specifies a format for files containing JPEG XR images. It uses syntax structures (IFD\_ENTRY( ) structures as specified in A.7) that each contain a syntax element (FIELD\_TAG as specified in A.7.2) that can be referred to as a tag. Therefore, this file format is referred to as being tag-based. The value of the tag serves as an identifier of the type of data contained in the syntax structure that is associated with the tag. + +NOTE 1 – The file format specified in this annex is based on that specified for use in ISO 12234-2, ISO 12639, TIFF Revision 6.0, and EXIF 2.2 (JEITA CP-3451), and is intended to provide a form of consistency and compatibility with those documents – e.g. to enable the sharing of some functional components designed for reading, writing, and otherwise making use of such files. + +NOTE 2 – This specification of this file format does not preclude the existence of alternative file format specifications for files containing JPEG XR images. + +NOTE 3 – When a file is formatted as specified in this annex, in addition to the syntax structures that are specified by this annex, arbitrary data (formatted in a manner not specified by this annex) may also be present at locations within the file that lie between or beyond the locations in the file that contain the syntax structures specified by this annex. + +NOTE 4 – The use of the filename extension ".jxr" is suggested for files conforming to the file format specified in this annex. + +The FILE\_HEADER( ) syntax structure specified in clause A.5 shall be present at the beginning of the file (at byte position 0). + +The variable FileSizeInBytes is considered to be equal to the total number of bytes in the file. The method of determining the value of FileSizeInBytes is determined by the application and is not specified in this Specification. The value of FileSizeInBytes shall not exceed $2^{32} - 1$ . + +For purposes of this Specification, a decoder is assumed to be capable of either storing the entire file in random access memory or performing random access seek operations to access the data at arbitrary specified positions in the file. + +#### A.2 Normative references + +The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this annex to this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations. + +##### A.2.1 Identical Recommendations | International Standards + +None. + +##### A.2.2 Paired Recommendations | International Standards equivalent in technical content + +None. + +##### A.2.3 Additional references + +- ISO/IEC 10646:2014, *Information technology – Universal Coded Character Set (UCS)*. +- ISO/IEC/IEEE 60559 (2011), *Information technology – Microprocessor Systems – Floating-Point arithmetic*. + +#### A.3 Definitions + +For the purposes of this annex to this Recommendation | International Standard, the following definitions apply. In this clause, *italic* is used to identify all occurrences of terms that are defined in this subclause or in clause 3. + +**A.3.1 interleaved alpha image plane:** *Images with the value of ALPHA\_IMAGE\_PLANE\_FLAG set equal to 1 have an interleaved alpha image plane.* + +**A.3.2 separate alpha image plane:** *Images with optional alpha image plane and the value of ALPHA\_IMAGE\_PLANE\_FLAG set equal to zero have a separate alpha image plane. For such images, data relating to* + +the *alpha image plane* is present in the CODED\_IMAGE() syntax structure specified by the ALPHA\_OFFSET syntax element. + +**A.3.3 universal multiple-octet coded character set transformation format 8 (UTF-8):** The 8-bit character set encoding specified in Annex D of ISO/IEC 10646. + +**A.4 Abbreviations** + +For the purposes of this annex to this Recommendation | International Standard, the following abbreviations apply. + +- CIE Commission Internationale de l’Eclairage (International Commission on Illumination) +- FCC Federal Communications Commission +- ICC International Color Consortium +- NTSC National Television System Committee +- RP Recommended Practice +- SMPTE Society of Motion Picture and Television Engineers +- UTF Universal multiple-octet coded character set Transformation Format (as specified by ISO/IEC 10646) +- UUID Universal Unique Identifier (as specified in Annex A of ISO/IEC 11578) + +**A.5 FILE\_HEADER()** + +**A.5.1 Syntax structure** + +The FILE\_HEADER() syntax structure is specified in Table A.1. + +**Table A.1 – FILE\_HEADER() syntax structure** + +| FILE_HEADER() { | Descriptor | Reference | +|-----------------------------|------------|-----------| +| FIXED_FILE_HEADER_II_2BYTES | u(16) | A.5.2 | +| FIXED_FILE_HEADER_0XBC_BYTE | u(8) | A.5.3 | +| FILE_VERSION_ID | u(8) | A.5.4 | +| FIRST_IFD_OFFSET | le(32) | A.5.5 | +| } | | | + +**A.5.2 FIXED\_FILE\_HEADER\_II\_2BYTES** + +FIXED\_FILE\_HEADER\_II\_2BYTES shall be equal to 0x4949. + +**A.5.3 FIXED\_FILE\_HEADER\_0XBC\_BYTE** + +FIXED\_FILE\_HEADER\_0XBC\_BYTE shall be equal to 0xBC. + +**A.5.4 FILE\_VERSION\_ID** + +FILE\_VERSION\_ID shall be equal to 1. Other values of FILE\_VERSION\_ID are reserved for future use, as modified in additional parts or amendments, by ITU-T | ISO/IEC. + +**A.5.5 FIRST\_IFD\_OFFSET** + +FIRST\_IFD\_OFFSET specifies the byte position, relative to the beginning of the file, of the first IMAGE\_FILE\_DIRECTORY() syntax structure (A.6) in the file. The value of FIRST\_IFD\_OFFSET shall be an integer multiple of 2. + +## A.6 IMAGE\_FILE\_DIRECTORY() + +### A.6.1 Syntax structure + +The IMAGE\_FILE\_DIRECTORY() syntax structure is specified in Table A.2. + +**Table A.2 – IMAGE\_FILE\_DIRECTORY() syntax structure** + +| IMAGE_FILE_DIRECTORY() { | Descriptor | Reference | +|-----------------------------------------------------------------------|------------|-----------| +| NUM_ENTRIES | le(16) | A.6.2 | +| for (iNumEntries = 0;
iNumEntries < NUM_ENTRIES;
iNumEntries++) | | | +| IFD_ENTRY() | | A.7 | +| ZERO_OR_NEXT_IFD_OFFSET | le(32) | A.6.3 | +| } | | | + +### A.6.2 NUM\_ENTRIES + +NUM\_ENTRIES specifies the number of entries in the IMAGE\_FILE\_DIRECTORY() syntax structure. NUM\_ENTRIES shall not be equal to 0. The value 0 for NUM\_ENTRIES is reserved for future use by ITU-T | ISO/IEC. + +### A.6.3 ZERO\_OR\_NEXT\_IFD\_OFFSET + +ZERO\_OR\_NEXT\_IFD\_OFFSET is interpreted as follows. + +- If ZERO\_OR\_NEXT\_IFD\_OFFSET is equal to 0, this indicates that no additional IMAGE\_FILE\_DIRECTORY() syntax structures are present in the file. +- Otherwise, ZERO\_OR\_NEXT\_IFD\_OFFSET specifies the byte position, relative to the beginning of the file, to the next IMAGE\_FILE\_DIRECTORY() syntax structure in the file. + +The value of ZERO\_OR\_NEXT\_IFD\_OFFSET shall be an integer multiple of 2. + +Decoders may ignore any IMAGE\_FILE\_DIRECTORY() syntax structures at locations in the file specified by any ZERO\_OR\_NEXT\_IFD\_OFFSET syntax element. + +## A.7 IFD\_ENTRY() + +### A.7.1 Syntax structure + +The IFD\_ENTRY() syntax structure is specified in Table A.3. + +**Table A.3 – IFD\_ENTRY() syntax structure** + +| IFD_ENTRY() { | Descriptor | Reference | +|------------------|------------|-----------| +| FIELD_TAG | le(16) | A.7.2 | +| ELEMENT_TYPE | le(16) | A.7.3 | +| NUM_ELEMENTS | le(32) | A.7.4 | +| VALUES_OR_OFFSET | le(32) | A.7.5 | +| } | | | + +The interpretation and presence of syntax elements of the IFD\_ENTRY() syntax structure is specified in Table A.4. The data associated with a FIELD\_TAG value is interpreted as the value of the syntax element or syntax structure in the "Syntax element or syntax structure" column. The term "variable" is used in Table A.4 to indicate cases in which NUM\_ELEMENTS may have any value corresponding to the quantity of associated data. The "Presence" column is interpreted as follows. + +- "Required" specifies that the FIELD\_TAG value shall be present in an IFD\_ENTRY() syntax structure of each IMAGE\_FILE\_DIRECTORY() syntax structure in the file. +- "Optional" indicates that the FIELD\_TAG value may or may not be present in an IFD\_ENTRY() syntax structure of each IMAGE\_FILE\_DIRECTORY() syntax structure in the file. + +IFD entries with combinations of FIELD\_TAG, ELEMENT\_TYPE, and NUM\_ELEMENTS that do not appear in Table A.4, with the FIELD\_TAG value in the range of 0x1000 to 0x3FFF and 0x5000 to 0x7FFF are reserved for future use by ITU-T | ISO/IEC. Decoders shall ignore (parse and discard) any IFD\_ENTRY() syntax structures in which such combinations appear. + +NOTE 1 – The purpose of the specification for decoders to ignore IFD entries with such combinations of FIELD\_TAG, ELEMENT\_TYPE, and NUM\_ELEMENTS is to enable the future definition of a backward-compatible usage of additional combinations. + +IFD entries with combinations of FIELD\_TAG, ELEMENT\_TYPE and NUM\_ELEMENTS that do not appear in Table A.4, with the FIELD\_TAG value in the range of 0x0000 to 0x0FFF, 0x4000 to 0x4FFF, and 0x8000 to 0xFFFF are available for unspecified use and interpretation as determined by the application. Decoders shall parse any IFD\_ENTRY() syntax structures in which such combinations appear and, for purposes relevant to determining conformance to this Specification, shall ignore these syntax structures. Any use of such FIELD\_TAG values shall not affect the expressed requirements for conformance to this Specification. Additionally, ITU-T and ISO/IEC reserve the ability to potentially specify uses for such FIELD\_TAG values in future revisions of this Specification. + +NOTE 2 – Since interpretation of such FIELD\_TAG values may be application specific, it is recommended that any such IFD\_ENTRY() syntax structures that have unknown interpretations be removed when transferring files between differing application domains. + +NOTE 3 – The use of a field tag value equal to 0x02BC in tag-based encoded files [such as files formatted according to ISO 12234-2, ISO 12639, TIFF Revision 6.0 or EXIF 2.2 (JEITA CP-3451)] is specified in ISO 16684-1. The use of a field tag value equal to 0x8769 is specified in section 4.6.3 of the EXIF 2.2 (JEITA CP-3451) specification. The use of a field tag value equal to 0x8773 is specified in clause B.3 of the ICC.1:2001-04 (ICC version 2.4.0.0) specification and in clause B.3 of ISO 15076-1:2010, which specify two versions of ICC profile data. The provision to allow these field tag values to be present is intended to allow the use of ISO 16684-1, EXIF 2.2 (JEITA CP-3451), ICC.1:2001-04 and ISO 15076-1:2010 specifications with files encoded according to this Specification (without imposing normative conformance requirements related to such use). The use of ICC profile data is further discussed in Annex C. + +**Table A.4 – Interpretation, allowed combinations, and presence of syntax elements of the IFD\_ENTRY() syntax structure** + +| FIELD_TAG | ELEMENT_TYPE | NUM_ELEMENTS | Syntax element or syntax structure | Presence | +|-----------|------------------------|--------------|------------------------------------|----------| +| 0x010D | UTF8 | variable | DOCUMENT_NAME | Optional | +| 0x010E | UTF8 | variable | IMAGE_DESCRIPTION | Optional | +| 0x010F | UTF8 | variable | EQUIPMENT_MAKE | Optional | +| 0x0110 | UTF8 | variable | EQUIPMENT_MODEL | Optional | +| 0x011D | UTF8 | variable | PAGE_NAME | Optional | +| 0x0129 | USHORT | 2 | PAGE_NUMBER | Optional | +| 0x0131 | UTF8 | variable | SOFTWARE_NAME_VERSION | Optional | +| 0x0132 | UTF8 | 20 | DATE_TIME | Optional | +| 0x013B | UTF8 | variable | ARTIST_NAME | Optional | +| 0x013C | UTF8 | variable | HOST_COMPUTER | Optional | +| 0x8298 | UTF8 | variable | COPYRIGHT_NOTICE | Optional | +| 0xA001 | USHORT | 1 | COLOR_SPACE | Optional | +| 0xBC01 | BYTE | 16 | PIXEL_FORMAT | Required | +| 0xBC02 | BYTE, USHORT, or ULONG | 1 | SPATIAL_XFRM_PRIMARY | Optional | +| 0xBC04 | ULONG | 1 | IMAGE_TYPE | Optional | +| 0xBC05 | BYTE | 4 | PTM_COLOR_INFO() | Optional | +| 0xBC06 | BYTE | variable | PROFILE_LEVEL_CONTAINER() | Optional | +| 0xBC80 | BYTE, USHORT, or ULONG | 1 | IMAGE_WIDTH | Required | +| 0xBC81 | BYTE, USHORT, or ULONG | 1 | IMAGE_HEIGHT | Required | +| 0xBC82 | FLOAT | 1 | WIDTH_RESOLUTION | Optional | +| 0xBC83 | FLOAT | 1 | HEIGHT_RESOLUTION | Optional | +| 0xBCC0 | BYTE, USHORT, or ULONG | 1 | IMAGE_OFFSET | Required | +| 0xBCC1 | BYTE, USHORT, or ULONG | 1 | IMAGE_BYTE_COUNT | Required | +| 0xBCC2 | BYTE, USHORT, or ULONG | 1 | ALPHA_OFFSET | Optional | +| 0xBCC3 | BYTE, USHORT, or ULONG | 1 | ALPHA_BYTE_COUNT | Optional | +| 0xBCC4 | BYTE | 1 | IMAGE_BAND_PRESENCE | Optional | +| 0xBCC5 | BYTE | 1 | ALPHA_BAND_PRESENCE | Optional | +| 0xEA1C | UNDEFINED | variable | PADDING_DATA | Optional | + +## A.7.2 FIELD\_TAG + +FIELD\_TAG identifies the data contained in the IFD\_ENTRY() syntax structure. When the IFD\_ENTRY() syntax structure is not the first IFD\_ENTRY() syntax structure of the IMAGE\_FILE\_DIRECTORY() syntax structure, the value of FIELD\_TAG shall be greater than the value of FIELD\_TAG in the preceding IFD\_ENTRY() syntax structure of the IMAGE\_FILE\_DIRECTORY() syntax structure. + +## A.7.3 ELEMENT\_TYPE + +ELEMENT\_TYPE identifies the type of data contained in the IFD\_ENTRY() syntax structure as specified in Table A.5. + +**Table A.5 – ELEMENT\_TYPE** + +| ELEMENT_TYPE | Mnemonic | SizeOfElement | +|--------------|-----------|---------------| +| 0 | RESERVED | Not specified | +| 1 | BYTE | 1 | +| 2 | UTF-8 | 1 | +| 3 | USHORT | 2 | +| 4 | ULONG | 4 | +| 5 | URATIONAL | 8 | +| 6 | SBYTE | 1 | +| 7 | UNDEFINED | 1 | +| 8 | SSHORT | 2 | +| 9 | SLONG | 4 | +| 10 | SRATIONAL | 8 | +| 11 | FLOAT | 4 | +| 12 | DOUBLE | 8 | +| 13-65535 | RESERVED | Not specified | + +The value of ELEMENT\_TYPE shall not be equal to RESERVED in files conforming to this version of this annex. Such values are reserved for use in future versions of this Specification. Decoders that encounter files containing ELEMENT\_TYPE equal to RESERVED shall ignore the associated data. + +When ELEMENT\_TYPE is equal to UNDEFINED, the value of FIELD\_TAG shall be equal to 0x8773 if it is not equal to 0xEA1C in files conforming to this version of this annex. Other values of ELEMENT\_TYPE are reserved for use in future versions of this Specification. + +The quantity of data associated with each syntax element VALUES\_OR\_OFFSET, as specified by ELEMENT\_TYPE in units of bytes, is specified in the SizeOfElement column of Table A.5. The interpretation of the data elements associated with each value of ELEMENT\_TYPE is specified as follows. + +- If ELEMENT\_TYPE is equal to BYTE, USHORT or ULONG, each data element is interpreted as an unsigned integer of the specified length in little-endian form. +- Otherwise, if ELEMENT\_TYPE is equal to SBYTE, SSHORT or SLONG, each data element is interpreted as a two's complement signed integer of the specified length in little-endian form. +- Otherwise, if ELEMENT\_TYPE is equal to UTF8, each data element is interpreted as a UTF-8 character set code as specified by Annex D of ISO/IEC 10646, and the value of the last data element of the IFD\_ENTRY() shall be equal to 0 (null). Any such field may contain multiple strings of UTF-8 characters, each terminated with a 0-valued character. The NUM\_ELEMENTS for such multi-string payloads is the total number of bytes in all of the associated strings including the 0-valued byte at the end of each such string. Within the associated NUM\_ELEMENTS bytes, there shall not be any two consecutive bytes equal to 0. +- Otherwise, if ELEMENT\_TYPE is equal to UNDEFINED, the interpretation of the data elements depends on the FIELD\_TAG value as follows: + - If the value of FIELD\_TAG is equal to 0xEA1C (PADDING\_DATA), the interpretation of each data element is specified in clause A.7.33. + - Otherwise, the interpretation of the data elements is not specified by this Specification. +- Otherwise, if ELEMENT\_TYPE is equal to URATIONAL, each data element is interpreted as a rational number having a numerator equal to the first 4 bytes of the data element value, interpreted as an unsigned integer of the + +specified length in little-endian form, and a denominator equal to the remaining 4 bytes of the data element value, interpreted as an unsigned integer of the specified length in little-endian form. + +- Otherwise, if ELEMENT\_TYPE is equal to SRATIONAL, each data element is interpreted as a rational number having a numerator equal to the first 4 bytes of the data element value, interpreted as a two's complement signed integer of the specified length in little-endian form, and a denominator equal to the remaining 4 bytes of the data element value, interpreted as a two's complement signed integer of the specified length in little-endian form. +- Otherwise, if ELEMENT\_TYPE is equal to FLOAT, each data element is interpreted as a 4-byte ISO/IEC/IEEE 60559 floating-point number in little-endian form. +- Otherwise (ELEMENT\_TYPE is equal to DOUBLE), each data element is interpreted as an 8-byte ISO/IEC/IEEE 60559 floating-point number in little-endian form. + +#### **A.7.4 NUM\_ELEMENTS** + +NUM\_ELEMENTS specifies the number of data elements associated with the IFD\_ENTRY( ) syntax structure. Let *iSizeOfElement* be equal to the value in the SizeOfElement column of Table A.5 for the value of ELEMENT\_TYPE. The total number of bytes of data associated with the IFD\_ENTRY( ) syntax structure is NUM\_ELEMENTS \* *iSizeOfElement*. + +NOTE – NUM\_ELEMENTS must be set to the total quantity of data elements, including termination indicator values such as null-valued terminators as applicable. + +#### **A.7.5 VALUES\_OR\_OFFSET** + +VALUES\_OR\_OFFSET is interpreted as follows: + +- Let *iSizeOfElement* be equal to the value in the SizeOfElement column of Table A.5 for the value of ELEMENT\_TYPE. If NUM\_ELEMENTS \* *iSizeOfElement* is less than or equal to 4, VALUES\_OR\_OFFSET contains the data elements associated with the IFD\_ENTRY( ) syntax structure. +- Otherwise, VALUES\_OR\_OFFSET specifies the byte position, relative to the beginning of the file, of the data elements associated with the IFD\_ENTRY( ) syntax structure. In this case, the value of the VALUES\_OR\_OFFSET syntax element shall be an integer multiple of 2. + +#### **A.7.6 DOCUMENT\_NAME** + +DOCUMENT\_NAME (when present) provides, as a UTF-8 character string, a name for the image. There are no specific conformance requirements for the content of the associated character string (other than that it follows the format conventions of the ELEMENT\_TYPE definition of the UTF-8 data type as specified in A.7.3). + +NOTE 1 – The name of this syntax element alludes to the intended interpretation instead of any normative meaning. + +NOTE 2 – DOCUMENT\_NAME is specified here in a manner that is intended to be consistent with the "DocumentName" tag specified in ISO 12639 and TIFF Revision 6.0. + +#### **A.7.7 IMAGE\_DESCRIPTION** + +IMAGE\_DESCRIPTION (when present) provides, as a UTF-8 character string, a title or description of the image subject matter. There are no specific conformance requirements for the content of the associated character string (other than that it follows the format conventions of the ELEMENT\_TYPE definition of the UTF8 data type as specified in A.7.3). + +NOTE 1 – The name of this syntax element alludes to the intended interpretation instead of any normative meaning. + +NOTE 2 – IMAGE\_DESCRIPTION is specified here in a manner that is intended to be consistent with the "ImageDescription" tag specified in ISO 12234-2, ISO 12639, TIFF Revision 6.0, and EXIF 2.2 (JEITA CP-3451). + +#### **A.7.8 EQUIPMENT\_MAKE** + +EQUIPMENT\_MAKE (when present) provides, as a UTF-8 character string, a name for the manufacturer or vendor of the camera, image-capturing device, scanner or other equipment that generated the image. There are no specific conformance requirements for the content of the associated character string (other than that it follows the format conventions of the ELEMENT\_TYPE definition of the UTF8 data type as specified in A.7.3). + +NOTE 1 – The name of this syntax element alludes to the intended interpretation instead of any normative meaning. + +NOTE 2 – EQUIPMENT\_MAKE is specified here in a manner that is intended to be consistent with the "Make" tag specified in ISO 12234-2, ISO 12639, TIFF Revision 6.0, and EXIF 2.2 (JEITA CP-3451). + +#### **A.7.9 EQUIPMENT\_MODEL** + +When present, EQUIPMENT\_MODEL provides, as a UTF-8 character string, a model name or model number of the camera, image-capturing device, scanner or other equipment that generated the image. There are no specific conformance + +requirements for the content of the associated character string (other than that it follows the format conventions of the ELEMENT\_TYPE definition of the UTF8 data type as specified in A.7.3). + +NOTE 1 – The name of this syntax element alludes to the intended interpretation instead of any normative meaning. + +NOTE 2 – EQUIPMENT\_MODEL is specified here in a manner that is intended to be consistent with the "Model" tag specified in ISO 12234-2, ISO 12639, TIFF Revision 6.0, and EXIF 2.2 (JEITA CP-3451). + +#### **A.7.10 PAGE\_NAME** + +PAGE\_NAME (when present) provides, as a UTF-8 character string, a name to be considered to be the name of a page to which the image is considered to belong. There are no specific conformance requirements for the content of the associated character string (other than that it follows the format conventions of the ELEMENT\_TYPE definition of the UTF8 data type as specified in A.7.3). + +NOTE 1 – The name of this syntax element alludes to the intended interpretation instead of any normative meaning. + +NOTE 2 – PAGE\_NAME is specified here in a manner that is intended to be consistent with the "PageName" tag specified in ISO 12639 and TIFF Revision 6.0. + +#### **A.7.11 PAGE\_NUMBER** + +PAGE\_NUMBER (when present) provides, as a pair of unsigned integers, a "page number" (the first number) to be considered the page number of a page from a sequence of pages (the second number) to which the image is considered to belong. There are no specific conformance requirements for the content of the associated character string (other than that it follows the format conventions of the ELEMENT\_TYPE definition of the USHORT data type as specified in A.7.3). + +NOTE 1 – The name of this syntax element alludes to the intended interpretation instead of any normative meaning. + +NOTE 2 – PAGE\_NUMBER is specified here in a manner that is intended to be consistent with the "PageNumber" tag specified in TIFF Revision 6.0. + +#### **A.7.12 SOFTWARE\_NAME\_VERSION** + +SOFTWARE\_NAME\_VERSION (when present) provides, as a UTF-8 character string, name and version number information for one or more software packages used in generating the image or file. There are no specific conformance requirements for the content of the associated character string (other than that it follows the format conventions of the ELEMENT\_TYPE definition of the UTF8 data type as specified in A.7.3). + +NOTE 1 – The name of this syntax element alludes to the intended interpretation instead of any normative meaning. + +NOTE 2 – SOFTWARE\_NAME\_VERSION is specified here in a manner that is intended to be consistent with the "Software" tag specified in ISO 12234-2, ISO 12639, TIFF Revision 6.0, and EXIF 2.2 (JEITA CP-3451). + +#### **A.7.13 DATE\_TIME** + +DATE\_TIME (when present) provides, as a UTF-8 character string, the date and time of the creation or last modification of the image. + +The value of NUM\_ELEMENTS for the DATE\_TIME tag shall be equal to 20. + +The interpretation of the UTF-8 character string associated with the DATE\_TIME tag shall be as follows. + +- If the UTF-8 character string associated with the DATE\_TIME tag is the string "0000:00:00 00:00:00" or this string with all "0" characters replaced by space (0x20) characters as in the string " : : : : ", followed by a byte equal to 0, this indicates that the date and time are unknown. +- Otherwise, the UTF-8 character string associated with the DATE\_TIME tag shall be formatted as "YYYY:MM:DD HH:MM:SS", followed by a byte equal to 0, where the formatting of this string shall be as follows. + - The "YYYY" part of the string shall contain a character string representation of a four-digit decimal number for a calendar year. + - Each colon character ":" part of the string shall be a colon ":" character (a byte equal to 0x3A). + - The "MM" part of the string shall contain a character string representation of a two-digit decimal number in the range from "01" to "12" for a month within the year (where "01" indicates January, "02" indicates February, etc.) or two space (0x20) characters. + - The "DD" part of the string shall contain a character string representation of a two-digit decimal number in the range from "01" to "31" for a day within the month (where "01" indicates the first day of the month, "02" indicates the second day of the month, etc.). + - The character separating the "DD" and "HH" parts of the string shall be a space character " " (a byte equal to 0x20). + +- The "HH" part of the string shall contain a character string representation of a two-digit decimal number in the range from "00" to "23" for an hour within the day, following a 24-hour time of day convention (where "00" indicates a time in the first hour of the day, "01" indicates a time in the second hour of the day, etc.). + +NOTE 1 – The time 00:00:00 is used to indicate midnight. Similarly, 00:00:01 indicates one second after midnight and 23:59:59 indicates one second prior to midnight. + +- The "MM" part of the string shall contain a character string representation of a two-digit decimal number in the range from "00" to "59" for a minute within the hour (where "00" indicates a time in the first minute of the hour, "01" indicates a time within the second minute of the hour, etc.). +- The "SS" part of the string shall contain a character string representation of a two-digit decimal number in the range from "00" to "59" for a second within the minute (where "00" indicates a time in the first second of the minute, "01" indicates a time within the second second of the minute, etc.). + +The time zone for the date and time are not specified in this version of this Specification. + +NOTE 2 – For example, the date and time may be referenced to the local time zone in which the encoding equipment is operated or is ordinarily kept. + +There are no additional specific conformance requirements for the content of the associated character string. + +NOTE 3 – The name of this syntax element alludes to the intended interpretation instead of any normative meaning. + +NOTE 4 – DATE\_TIME is specified here in a manner that is intended to be consistent with the "DateTime" tag specified in ISO 12234-2, ISO 12639, TIFF Revision 6.0, and EXIF 2.2 (JEITA CP-3451). + +### A.7.14 ARTIST\_NAME + +ARTIST\_NAME (when present) provides, as a UTF-8 character string, one or more names and possibly additional information relating to persons involved in the creation of the image. There are no specific conformance requirements for the content of the associated character string (other than that it follows the format conventions of the ELEMENT\_TYPE definition of the UTF8 data type as specified in A.7.3). + +NOTE 1 – The name of this syntax element alludes to the intended interpretation instead of any normative meaning. + +NOTE 2 – ARTIST\_NAME is specified here in a manner that is intended to be consistent with the "Artist" tag specified in ISO 12234-2, ISO 12639, TIFF Revision 6.0, and EXIF 2.2 (JEITA CP-3451). An example preferred use of ARTIST\_NAME is the string value "Camera owner, John Smith; Photographer, Michael Brown; Image creator, Ken James" (followed by a byte equal to 0). + +### A.7.15 HOST\_COMPUTER + +HOST\_COMPUTER (when present) provides, as a UTF-8 character string, an indication of a computer, operating system or other system used in generating the image or file. There are no specific conformance requirements for the content of the associated character string (other than that it follows the format conventions of the ELEMENT\_TYPE definition of the UTF8 data type as specified in A.7.3). + +NOTE 1 – The name of this syntax element alludes to the intended interpretation instead of any normative meaning. + +NOTE 2 – HOST\_COMPUTER is specified here in a manner that is intended to be consistent with the "HostComputer" tag specified in ISO 12639 and TIFF Revision 6.0. + +### A.7.16 COPYRIGHT\_NOTICE + +COPYRIGHT\_NOTICE (when present) provides, as a UTF-8 character string, an indication of copyright rights associated with the image or file. There are no specific conformance requirements for the content of the associated character string (other than that it follows the format conventions of the ELEMENT\_TYPE definition of the UTF8 data type as specified in A.7.3). + +NOTE 1 – The name of this syntax element alludes to the intended interpretation instead of any normative meaning. + +NOTE 2 – COPYRIGHT\_NOTICE is specified here in a manner that is intended to be consistent with the "Copyright" tag specified in ISO 12234-2, ISO 12639, TIFF Revision 6.0, and EXIF 2.2 (JEITA CP-3451). A complete copyright statement should be listed in the character string including any dates and statements of claims – e.g., "Copyright, John Smith, 2009. All rights reserved" (followed by a byte equal to 0). When desired, this character string can also list a royalty clearing house. The string may be used to indicate either or both photographer and editor copyrights as well as any additional or alternative copyrights that apply to the image or file. When a photographer statement is included, it should appear first. When no photographer copyright statement is included and an editor or additional or alternative copyright statement is included, the absence of a photographer copyright statement should be indicated by a space character (0x20) followed by a byte equal to 0 (null) at the beginning of the character string. When an editor copyright statement is included, it should appear next. When no editor copyright statement is included and some additional or alternative copyright statement is included, the absence of an editor copyright statement should be indicated by a space character (0x20) followed by a byte equal to 0 (null) at the position in the character string at which the editor copyright statement would otherwise appear. When some additional or alternative copyright statement is included, it should appear next. When present, each additional or alternative copyright statement should end with a byte equal to 0 (null). When a royalty clearing house listing is included, this listing should appear last. + +### A.7.17 COLOR\_SPACE + +COLOR\_SPACE (when present) equal to 1, when the value in the Num column in Table A.6 for the line corresponding to the value of PIXEL\_FORMAT is equal to UINT, indicates that the associated image should be interpreted according to the sRGB specification IEC 61966-2-1. COLOR\_SPACE equal to 0xFFFF, when used with an unsigned pixel format as specified by PIXEL\_FORMAT, indicates that the sRGB specification may not be the preferred method of interpretation of the associated image. + +COLOR\_SPACE shall not be equal to 1 when PIXEL\_FORMAT specifies a fixed or floating point pixel format. + +When present, COLOR\_SPACE shall be equal to 1 or 0xFFFF. All other values are reserved for future use by ITU-T | ISO/IEC. All values other than 1 and 0xFFFF shall be treated the same as the value 0xFFFF by decoders. + +NOTE – sRGB image data is used in many systems, being interpreted directly by various receiving devices. + +### A.7.18 PIXEL\_FORMAT + +PIXEL\_FORMAT consists of a string of 16 BYTE values. The values of the bytes ordered from first to last in this string are interpreted as digit pairs appearing from left to right in the hexadecimal integer values specified in Table A.6. + +NOTE 1 – The PIXEL\_FORMAT values specified in Table A.6 originated as UUID values as specified by ISO/IEC 11578. UUID values are commonly shown as a string of hexadecimal digits separated by dash "-" characters. The bytes of such a UUID value are typically stored in a file using a rearranged form of such a typical dashed-form description. In Table A.6, that convention is not followed. Instead, the values are specified in a manner intended to ease the interpretation of the value as a string of 16 BYTE values that can be directly compared to the provided strings of hexadecimal digits. The rearrangement of the common form of UUID specification to produce the equivalent ordered string of BYTE values as shown in Table A.6 can be performed as follows. + +- The first (leftmost) 4 bytes (which precede the first dash character in the common form of UUID value specification) are ordered first, represented in little-endian (byte-reversed) form. +- The next two bytes (which precede the second dash character in the common form of UUID value specification) are ordered next, represented in little-endian (byte-reversed) form. +- The next two bytes (which precede the third dash character in the common form of UUID value specification) are ordered next, represented in little-endian (byte-reversed) form. +- The remaining bytes in the common form of UUID value specification follow, in left-to-right order. + +The headings of Table A.6 are interpreted as follows: + +- "Mnemonic name" indicates a string associated with the syntax element corresponding to the value of PIXEL\_FORMAT. +- "NC" specifies the following. + - If the value of PIXEL\_FORMAT specifies that no alpha channel is present (as specified by the entry in the "Alpha" column), it is a requirement for file format conformance to this annex that the value of NumComponents as calculated in Table 31 shall be equal to the value of the entry in the "NC" column. + - Otherwise, if the alpha channel is present as a separate alpha image plane (as specified by the entry in the "Alpha" column and the presence of ALPHA\_OFFSET), it is a requirement for file format conformance to this annex that the value of NumComponents as calculated in Table 31 for the CODED\_IMAGE( ) syntax structure at the position specified by IMAGE\_OFFSET shall be equal to the value of the entry in the "NC" column minus 1, and the value of NumComponents as calculated in Table 31 for the CODED\_IMAGE( ) syntax structure at the position specified by ALPHA\_OFFSET shall be equal to 1. + - Otherwise (the alpha channel is present as an interleaved alpha image plane), it is a requirement for file format conformance to this annex that the value of NumComponents as calculated in Table 31 for the primary image plane shall be equal to the value of the entry in the "NC" column minus 1, and the value of NumComponents as calculated in Table 31 for the alpha image plane shall be equal to 1. +- "Alpha" specifies whether the PIXEL\_FORMAT specifies the presence of an alpha channel. An entry marked with "✓" indicates that an alpha channel is present and an entry not marked with "✓" indicates that an alpha channel is not present. +- "BPC" specifies a requirement for file format conformance to this annex that the value of the OUTPUT\_BITDEPTH syntax element of the CODED\_IMAGE( ) syntax structure at the position specified by IMAGE\_OFFSET shall be equal to the value of the entry in the "BPC" column and, when present, the value of the OUTPUT\_BITDEPTH syntax element of the CODED\_IMAGE( ) syntax structure at the position specified by ALPHA\_OFFSET shall be equal to value of the entry in the "BPC" column. +- "Num" specifies the numeric interpretation of values in the decoded image. + +- "Colour" specifies a requirement for file format conformance to this annex that the value of the OUTPUT\_CLR\_FMT syntax element of the CODED\_IMAGE() syntax structure at the position specified by IMAGE\_OFFSET shall be equal to the value of the entry in the "Colour" column. + +NOTE 2 – Image data may be structured as single channel monochrome "Gray", three-channel "RGB", four-channel "CMYK" or n-Channel ("NCOMPONENT") with n in the range of 2 to 16, inclusive. + +**Table A.6 – Interpretation of PIXEL\_FORMAT** + +| PIXEL_FORMAT value | Mnemonic | NC | Alpha | BPC | Num | Colour | +|------------------------------------|----------------------|----|-------|-------|-------|------------| +| 0x24C3DD6F034EFE4BB1853D77768DC90D | 24bppRGB | 3 | | BD8 | UINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC90C | 24bppBGR | 3 | | BD8 | UINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC90E | 32bppBGR | 3 | | BD8 | UINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC915 | 48bppRGB | 3 | | BD16 | UINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC912 | 48bppRGBFixedPoint | 3 | | BD16S | SINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC93B | 48bppRGBHalf | 3 | | BD16F | Float | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC918 | 96bppRGBFixedPoint | 3 | | BD32S | SINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC940 | 64bppRGBFixedPoint | 3 | | BD16S | SINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC942 | 64bppRGBHalf | 3 | | BD16F | Float | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC941 | 128bppRGBFixedPoint | 3 | | BD32S | SINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC91B | 128bppRGBFloat | 3 | | BD32F | Float | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC90F | 32bppBGRA | 4 | ✓ | BD8 | UINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC916 | 64bppRGBA | 4 | ✓ | BD16 | UINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC91D | 64bppRGBAFixedPoint | 4 | ✓ | BD16S | SINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC93A | 64bppRGBAHalf | 4 | ✓ | BD16F | Float | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC91E | 128bppRGBAFixedPoint | 4 | ✓ | BD32S | SINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC919 | 128bppRGBAFloat | 4 | ✓ | BD32F | Float | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC910 | 32bppPBGRA | 4 | ✓ | BD8 | UINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC917 | 64bppPRGBA | 4 | ✓ | BD16 | UINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC91A | 128bppPRGBAFloat | 4 | ✓ | BD32F | Float | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC91C | 32bppCMYK | 4 | | BD8 | UINT | CMYK | +| 0x24C3DD6F034EFE4BB1853D77768DC92C | 40bppCMYKAlpha | 5 | ✓ | BD8 | UINT | CMYK | +| 0x24C3DD6F034EFE4BB1853D77768DC91F | 64bppCMYK | 4 | | BD16 | UINT | CMYK | +| 0x24C3DD6F034EFE4BB1853D77768DC92D | 80bppCMYKAlpha | 5 | ✓ | BD16 | UINT | CMYK | +| 0x24C3DD6F034EFE4BB1853D77768DC920 | 24bpp3Channels | 3 | | BD8 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC921 | 32bpp4Channels | 4 | | BD8 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC922 | 40bpp5Channels | 5 | | BD8 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC923 | 48bpp6Channels | 6 | | BD8 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC924 | 56bpp7Channels | 7 | | BD8 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC925 | 64bpp8Channels | 8 | | BD8 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC92E | 32bpp3ChannelsAlpha | 4 | ✓ | BD8 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC92F | 40bpp4ChannelsAlpha | 5 | ✓ | BD8 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC930 | 48bpp5ChannelsAlpha | 6 | ✓ | BD8 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC931 | 56bpp6ChannelsAlpha | 7 | ✓ | BD8 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC932 | 64bpp7ChannelsAlpha | 8 | ✓ | BD8 | UINT | NCOMPONENT | + +| PIXEL_FORMAT value | Mnemonic | NC | Alpha | BPC | Num | Colour | +|------------------------------------|-----------------------|----|-------|------------------------|-------|------------| +| 0x24C3DD6F034EFE4BB1853D77768DC933 | 72bpp8ChannelsAlpha | 9 | ✓ | BD8 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC926 | 48bpp3Channels | 3 | | BD16 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC927 | 64bpp4Channels | 4 | | BD16 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC928 | 80bpp5Channels | 5 | | BD16 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC929 | 96bpp6Channels | 6 | | BD16 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC92A | 112bpp7Channels | 7 | | BD16 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC92B | 128bpp8Channels | 8 | | BD16 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC934 | 64bpp3ChannelsAlpha | 4 | ✓ | BD16 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC935 | 80bpp4ChannelsAlpha | 5 | ✓ | BD16 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC936 | 96bpp5ChannelsAlpha | 6 | ✓ | BD16 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC937 | 112bpp6ChannelsAlpha | 7 | ✓ | BD16 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC938 | 128bpp7ChannelsAlpha | 8 | ✓ | BD16 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC939 | 144bpp8ChannelsAlpha | 9 | ✓ | BD16 | UINT | NCOMPONENT | +| 0x24C3DD6F034EFE4BB1853D77768DC908 | 8bppGray | 1 | | BD8 | UINT | YONLY | +| 0x24C3DD6F034EFE4BB1853D77768DC90B | 16bppGray | 1 | | BD16 | UINT | YONLY | +| 0x24C3DD6F034EFE4BB1853D77768DC913 | 16bppGrayFixedPoint | 1 | | BD16S | SINT | YONLY | +| 0x24C3DD6F034EFE4BB1853D77768DC93E | 16bppGrayHalf | 1 | | BD16F | Float | YONLY | +| 0x24C3DD6F034EFE4BB1853D77768DC93F | 32bppGrayFixedPoint | 1 | | BD32S | SINT | YONLY | +| 0x24C3DD6F034EFE4BB1853D77768DC911 | 32bppGrayFloat | 1 | | BD32F | Float | YONLY | +| 0x24C3DD6F034EFE4BB1853D77768DC905 | BlackWhite | 1 | | BD1WHITE1 or BD1BLACK1 | UINT | YONLY | +| 0x24C3DD6F034EFE4BB1853D77768DC909 | 16bppBGR555 | 3 | | BD5 | UINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC90A | 16bppBGR565 | 3 | | BD565 | UINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC914 | 32bppBGR101010 | 3 | | BD10 | UINT | RGB | +| 0x24C3DD6F034EFE4BB1853D77768DC93D | 32bppRGBE | 3 | | BD8 | Float | RGBE | +| 0x24C3DD6F034EFE4BB1853D77768DC954 | 32bppCMYKDIRECT | 4 | | BD8 | UINT | CMYKDIRECT | +| 0x24C3DD6F034EFE4BB1853D77768DC955 | 64bppCMYKDIRECT | 4 | | BD16 | UINT | CMYKDIRECT | +| 0x24C3DD6F034EFE4BB1853D77768DC956 | 40bppCMYKDIRECTAlpha | 5 | ✓ | BD8 | UINT | CMYKDIRECT | +| 0x24C3DD6F034EFE4BB1853D77768DC943 | 80bppCMYKDIRECTAlpha | 5 | ✓ | BD16 | UINT | CMYKDIRECT | +| 0x24C3DD6F034EFE4BB1853D77768DC944 | 12bppYCC420 | 3 | | BD8 | UINT | YUV420 | +| 0x24C3DD6F034EFE4BB1853D77768DC945 | 16bppYCC422 | 3 | | BD8 | UINT | YUV422 | +| 0x24C3DD6F034EFE4BB1853D77768DC946 | 20bppYCC422 | 3 | | BD10 | UINT | YUV422 | +| 0x24C3DD6F034EFE4BB1853D77768DC947 | 32bppYCC422 | 3 | | BD16 | UINT | YUV422 | +| 0x24C3DD6F034EFE4BB1853D77768DC948 | 24bppYCC444 | 3 | | BD8 | UINT | YUV444 | +| 0x24C3DD6F034EFE4BB1853D77768DC949 | 30bppYCC444 | 3 | | BD10 | UINT | YUV444 | +| 0x24C3DD6F034EFE4BB1853D77768DC94A | 48bppYCC444 | 3 | | BD16 | UINT | YUV444 | +| 0x24C3DD6F034EFE4BB1853D77768DC94B | 48bppYCC444FixedPoint | 3 | | BD16S | SINT | YUV444 | +| 0x24C3DD6F034EFE4BB1853D77768DC94C | 20bppYCC420Alpha | 4 | ✓ | BD8 | UINT | YUV420 | + +| PIXEL_FORMAT value | Mnemonic | NC | Alpha | BPC | Num | Colour | +|------------------------------------|----------------------------|-----------|--------------|------------|------------|---------------| +| 0x24C3DD6F034EFE4BB1853D77768DC94D | 24bppYCC422Alpha | 4 | ✓ | BD8 | UINT | YUV422 | +| 0x24C3DD6F034EFE4BB1853D77768DC94E | 30bppYCC422Alpha | 4 | ✓ | BD10 | UINT | YUV422 | +| 0x24C3DD6F034EFE4BB1853D77768DC94F | 48bppYCC422Alpha | 4 | ✓ | BD16 | UINT | YUV422 | +| 0x24C3DD6F034EFE4BB1853D77768DC950 | 32bppYCC444Alpha | 4 | ✓ | BD8 | UINT | YUV444 | +| 0x24C3DD6F034EFE4BB1853D77768DC951 | 40bppYCC444Alpha | 4 | ✓ | BD10 | UINT | YUV444 | +| 0x24C3DD6F034EFE4BB1853D77768DC952 | 64bppYCC444Alpha | 4 | ✓ | BD16 | UINT | YUV444 | +| 0x24C3DD6F034EFE4BB1853D77768DC953 | 64bppYCC444AlphaFixedPoint | 4 | ✓ | BD16S | SINT | YUV444 | + +The manner of output for the decoded image data produced from a conforming decoder may be determined by the application. However, each PIXEL\_FORMAT value specified in Table A.6 has a corresponding defined output format that is specified for reference purposes as the output of a hypothetical reference decoder. This reference output format is in the form of an ordered string of bytes defined as follows. + +- If PIXEL\_FORMAT is equal to 24bppRGB, the decoded channels are interleaved on a sample-by-sample basis in raster scan order, where the ordering of the interleaving is R, then G, then B, and each sample value for each channel is output as a single byte. + - Otherwise, if PIXEL\_FORMAT is equal to 32bppRGBE, the decoded channels are interleaved on a sample-by-sample basis in raster scan order, where the ordering of the interleaving is B, then G, then R, then E, and each sample value for each channel is output as a single byte. + - Otherwise, if PIXEL\_FORMAT is equal to 48bppRGB, 48bppRGBFixedPoint or 48bppRGBHalf, the decoded channels are interleaved on a sample-by-sample basis in raster scan order, where the ordering of the interleaving is R, then G, then B, and each sample value for each channel is output using 16 bits in little-endian form. + - Otherwise, if PIXEL\_FORMAT is equal to 96bppRGBFixedPoint, the decoded channels are interleaved on a sample-by-sample basis in raster scan order, where the ordering of the interleaving is R, then G, then B, and each sample value for each channel is output using 32 bits in little-endian form. + - Otherwise, if PIXEL\_FORMAT is equal to 64bppRGBFixedPoint or 64bppRGBHalf, the decoded channels are interleaved on a sample-by-sample basis in raster scan order, where the ordering of the interleaving is R, then G, then B, then a padding channel, and each sample value for each channel is output using 16 bits in little-endian form. + - Otherwise, if PIXEL\_FORMAT is equal to 128bppRGBFixedPoint or 128bppRGBFloat, the decoded channels are interleaved on a sample-by-sample basis in raster scan order, where the ordering of the interleaving is R, then G, then B, then a padding channel, and each sample value for each channel is output using 32 bits in little-endian form. + - Otherwise, if PIXEL\_FORMAT is equal to 64bppRGBA, 64bppRGBAFixedPoint, 64bppRGBAHalf or 64bppPRGBA, the decoded channels are interleaved on a sample-by-sample basis in raster scan order, where the ordering of the interleaving is R, then G, then B, then Alpha, and each sample value for each channel is output using 16 bits in little-endian form. + - Otherwise, if PIXEL\_FORMAT is equal to 128bppRGBAFixedPoint, 128bppRGBAFloat or 128bppPRGBAFloat, the decoded channels are interleaved on a sample-by-sample basis in raster scan order, where the ordering of the interleaving is R, then G, then B, then Alpha, and each sample value for each channel is output using 32 bits in little-endian form. + - Otherwise, if PIXEL\_FORMAT is equal to 24bppBGR, the decoded channels are interleaved on a sample-by-sample basis in raster scan order, where the ordering of the interleaving is B, then G, then R, and each sample value for each channel is output as a single byte. + - Otherwise, if PIXEL\_FORMAT is equal to 32bppBGR, the decoded channels are interleaved on a sample-by-sample basis in raster scan order, where the ordering of the interleaving is B, then G, then R, then a padding channel, and each sample value for each channel is output as a single byte. + - Otherwise, if PIXEL\_FORMAT is equal to 32bppPBGRA, the decoded channels are interleaved on a sample-by-sample basis in raster scan order, where the ordering of the interleaving is B, then G, then R, then Alpha, and each sample value for each channel is output as a single byte. + - Otherwise, if PIXEL\_FORMAT is equal to 16bppBGR565, the output is in the form of packed bit fields within the integer values specified in Table 196, and these integer values are output in raster scan order using 16 bits in little-endian form. (See Note 3.) + - Otherwise, if PIXEL\_FORMAT is equal to 16bppBGR555, the output is in the form of packed bit fields within the integer values specified in Table 197, and these integer values are output in raster scan order using 16 bits in little-endian form. (See Note 3.) + - Otherwise, if PIXEL\_FORMAT is equal to 32bppBGR101010, the output is in the form of packed bit fields within the integer values specified in Table 198, and these integer values are output in raster scan order using 32 bits in little-endian form. (See Note 3.) +- NOTE 3 – When the PIXEL\_FORMAT is equal to 16bppBGR565, 16bppBGR555 or 32bppBGR101010, the positions of the bits representing the actual R and B components depend on the value of the RED\_BLUE\_NOT\_SWAPPED\_FLAG. In these cases, if RED\_BLUE\_NOT\_SWAPPED\_FLAG is equal to 0, the R component bits are in the MSBs of the packed bit fields and the B component bits are in the LSBs; otherwise, in these cases the R component bits are in the LSBs of the packed bit fields and the B component bits are in the MSBs. +- Otherwise, if PIXEL\_FORMAT is equal to BlackWhite, the output is in the form of packed bit fields within the integer values specified in Table 199, and these integer values are output as bytes in raster scan order. + +- Otherwise, if PIXEL\_FORMAT is equal to 32bppCMYK or 32bppCMYKDIRECT, the decoded channels are interleaved on a sample-by-sample basis in raster scan order, where the ordering of the interleaving is C, then M, then Y, then K, and each sample value for each channel is output as a single byte. +- Otherwise, if PIXEL\_FORMAT is equal to 40bppCMYKAlpha or 40bppCMYKDIRECTAlpha, the decoded channels are interleaved on a sample-by-sample basis in raster scan order, where the ordering of the interleaving is C, then M, then Y, then K, then Alpha, and each sample value for each channel is output as a single byte. +- Otherwise, if PIXEL\_FORMAT is equal to 64bppCMYK or 64bppCMYKDIRECT, the decoded channels are interleaved on a sample-by-sample basis in raster scan order, where the ordering of the interleaving is C, then M, then Y, then K, and each sample value for each channel is output using 16 bits in little-endian form. +- Otherwise, if PIXEL\_FORMAT is equal to 80bppCMYKAlpha or 80bppCMYKDIRECTAlpha, the decoded channels are interleaved on a sample-by-sample basis in raster scan order, where the ordering of the interleaving is C, then M, then Y, then K, then Alpha, and each sample value for each channel is output using 16 bits in little-endian form. +- Otherwise, if PIXEL\_FORMAT is equal to 12bppYCC420, 16bppYCC422 or 24bppYCC444, the Y samples are output first in raster scan order, then the U samples are output in raster scan order, then the V samples are output in raster scan order, and each sample value for each channel is output as a single byte. +- Otherwise, if PIXEL\_FORMAT is equal to 20bppYCC422, 32bppYCC422, 30bppYCC444, 48bppYCC444 or 48bppYCC444FixedPoint, the Y samples are output first in raster scan order, then the U samples are output in raster scan order, then the V samples are output in raster scan order, and each sample value for each channel is output using 16 bits in little-endian form. +- Otherwise, if PIXEL\_FORMAT is equal to 20bppYCC420Alpha or 24bppYCC422Alpha, the Y samples are output first in raster scan order, then the U samples are output in raster scan order, then the V samples are output in raster scan order, then the Alpha samples are output in raster scan order, and each sample value for each channel is output as a single byte. +- Otherwise, if PIXEL\_FORMAT is equal to 32bppYCC444Alpha, the Y samples are output first in raster scan order, then the U samples are output in raster scan order, then the V samples are output in raster scan order, then the Alpha samples are output in raster scan order, and each sample value for each channel is output as a single byte. +- Otherwise, if PIXEL\_FORMAT is equal to 30bppYCC422Alpha, 48bppYCC422Alpha, 40bppYCC444Alpha, 64bppYCC444Alpha or 64bppYCC444AlphaFixedPoint, the Y samples are output first in raster scan order, then the U samples are output in raster scan order, then the V samples are output in raster scan order, then the Alpha samples are output in raster scan order, and each sample value for each channel is output using 16 bits in little-endian form. +- Otherwise, if PIXEL\_FORMAT is equal to 24bpp3Channels, 32bpp4Channels, 40bpp5Channels, 48bpp6Channels, 56bpp7Channels or 64bpp8Channels, the decoded channels are ordered by increasing channel number, and the samples of each channel are output in raster scan order, and each sample value for each channel is output as a single byte. +- Otherwise, if PIXEL\_FORMAT is equal to 48bpp3Channels, 64bpp4Channels, 80bpp5Channels, 96bpp6Channels, 112bpp7Channels or 128bpp8Channels, the decoded channels are ordered by increasing channel number, and the samples of each channel are output in raster scan order, and each sample value for each channel is output using 16 bits in little-endian form. +- Otherwise, if PIXEL\_FORMAT is equal to 32bpp3ChannelsAlpha, 40bpp4ChannelsAlpha, 48bpp5ChannelsAlpha, 56bpp6ChannelsAlpha, 64bpp7ChannelsAlpha or 72bpp8ChannelsAlpha, the decoded channels are ordered by increasing channel number with the Alpha channel being considered as having the highest channel number and the samples of each channel are output in raster scan order, and each sample value for each channel is output as a single byte. +- Otherwise, if PIXEL\_FORMAT is equal to 64bpp3ChannelsAlpha, 80bpp4ChannelsAlpha, 96bpp5ChannelsAlpha, 112bpp6ChannelsAlpha, 128bpp7ChannelsAlpha or 144bpp8ChannelsAlpha, the decoded channels are ordered by increasing channel number and the last channel is considered the Alpha channel, and the samples of each channel are output in raster scan order, and each sample value for each channel is output using 16 bits in little-endian form. +- Otherwise, if PIXEL\_FORMAT is equal to 8bppGray, there is only one decoded channel, and the samples of that channel are output in raster scan order, and each sample value is output as a single byte. +- Otherwise, if PIXEL\_FORMAT is equal to 16bppGray, 16bppGrayFixedPoint or 16bppGrayHalf, there is only one decoded channel, and the samples of that channel are output in raster scan order, and each sample value is output using 16 bits in little-endian form. + +- Otherwise (PIXEL\_FORMAT is equal to 32bppGrayFixedPoint or 32bppGrayFloat), there is only one decoded channel, and the samples of that channel are output in raster scan order, and each sample value is output using 32 bits in little-endian form. + +NOTE 4 – Particular care should be taken with regard to the interpretation of this defined output format for PIXEL\_FORMAT values with mnemonic names that include "RGB", "BGR" or "CMYK" as part of the mnemonic name due to the specification of little-endian form for packed bit fields. In particular, the first byte of each packed bit field for the PIXEL\_FORMAT values 16bppBGR565, 16bppBGR555, and 32bppBGR101010 actually contains the LSBs of the packed bit fields due to the use of little-endian form. Similarly, if the 4 bytes that contain the decoded channel samples for the PIXEL\_FORMAT values 32bppRGBE, 32bppBGR, 32bppPBGRA, 32bppCMYK, and 32bppCMYKDIRECT are written or read as 32-bit integers in little-endian form rather than as ordered strings of 4 bytes in which each byte represents a sample value, the ordering of the channels will be swapped relative to the ordering described herein. + +This defined format is specified for reference purposes and may be used by some decoders as an interface format for the output of decoded pictures. However, the use of this defined format is not a requirement for conformance to this Specification. + +Interpretation of alpha channel information (when present) is considered pre-multiplied or not pre-multiplied as follows. + +- If PIXEL\_FORMAT is equal to 32bppPBGRA, 64bppPRGBA or 128bppPRGBAFloat, the channels other than the alpha channel are considered to be in pre-multiplied form in relation to the alpha channel. +- Otherwise, the channels other than the alpha channel are considered not to be in pre-multiplied form in relation to the alpha channel. In these cases, the value of PREMULIPLIED\_ALPHA\_FLAG in the associated IMAGE\_HEADER( ) of the coded image that contains the alpha channel shall be equal to 0. + +NOTE 5 – The designation of an alpha channel as pre-multiplied indicates that the decoded sample values do not require multiplication by the alpha channel values when performing compositing (as any such necessary multiplication process was performed as a pre-processing step prior to encoding). + +JPEG XR supports three types of numerical encoding: unsigned integer, fixed point, and floating point, each at a variety of bit depths. + +PIXEL\_FORMAT values having the "Num" column of Table A.6 indicating "UINT" are unsigned integer formats as follows. + +- If BPC is equal to BD8, the minimum value is 0 and the maximum value is 255, providing 256 unique values. +- Otherwise (BPC is equal to BD16), the minimum value is 0 and the maximum value is 65 535, providing 65 536 unique values. + +In unsigned integer cases, a value of zero ordinarily represents the minimum level or the encoding black for the specific channel and the maximum possible value represents the maximum value for that channel. When all viewable channels for a pixel format are at their maximum numerical value, this corresponds to the brightest representable colour or the encoding white. Exceptions to this general rule include the following unsigned integer cases. + +- When OUTPUT\_BITDEPTH is BD1BLACK1, a value of zero represents the maximum level or white and a value of one represents the minimum level or black. +- When the OUTPUT\_CLR\_FMT is YUV444, YUV422 or YUV420, the U and V components are interpreted as colour difference representations that are offset by a constant value, such that the middle value of the range of possible integer values is used for the representation of both the encoding black and the encoding white. +- When the OUTPUT\_CLR\_FMT is CMYK or CMYKDIRECT, the K component is interpreted as a degree of proximity toward black, such that the maximum value for the K component is used for the encoding black and the minimum value for the K component is used for the encoding white. +- When the OUTPUT\_CLR\_FMT is NCOMPONENT and the number of encoded components other than the Alpha channel (when present) is greater than 3, in the absence of other information to assist in the colour channel interpretation, the fourth channel should be interpreted as a K channel indicating a degree of proximity toward black as in the cases when the OUTPUT\_CLR\_FMT is CMYK or CMYKDIRECT (see also Annex C). + +PIXEL\_FORMAT values having mnemonic names that end in "FixedPoint" specify fixed point representations. + +NOTE 6 – A fixed point numerical representation is not commonly supported in prior image file formats. It is supported in JPEG XR to encode an extended range of numerical values more directly while retaining the performance advantages of integer processing. + +JPEG XR supports fixed point numerical encoding for 16-bit and 32-bit signed values. In this Specification, the abbreviation SINT is used to refer to signed integer or fixed point values. + +Fixed point values having BPC equal to 16 or 32 are interpreted as follows. + +- 16-bit Fixed Point, a format referred to as s2.13: The 16 bits that make up an individual value are interpreted as a sign bit, two integer bits and 13 fractional bits. Using this interpretation, a numerical range of $-4.0$ to $+3.999\dots$ can be represented, with the value of 1.0 represented by the signed integer value 8 192 (0x2000). + +- 32-bit Fixed Point, a format referred to as s7.24: The 32 bits that make up an individual value are interpreted as a sign bit, seven integer bits and 24 fractional bits. Using this interpretation, a numerical range of $-128.0$ to $+127.999\dots$ can be represented, with the value of 1.0 represented by the signed integer value 16 777 216 (0x01000000). + +NOTE 7 – JPEG XR does not enable fully lossless compression for 32-bit data in general. The encoding and decoding algorithms use 32-bit computations, and some dynamic range is lost to necessary headroom for signal processing calculations such as overlap and core transform computations. A minimum of 22 bits and typically 24 bits or more precision is retained through the end-to-end encoding and decoding process. + +PIXEL\_FORMAT values having the "Num" column of Table A.6 indicating "Float" (floating point values) are floating point formats. + +JPEG XR supports floating point numerical encoding for 16-bit and 32-bit depths. A packed bit RGB float format is also supported in the form of the RGBE format. + +The format of the floating point values is based on the "BPC" column of Table A.6 as follows: + +- BPC equal to BD16F indicates the "s5e10" format. The 16 bits are formatted in accordance with the HALF floating point format, with 1 sign bit, 5 exponent bits and 10 normalized mantissa bits. +- BPC equal to BD8 with PIXEL\_FORMAT equal to 32bppRGBE indicates a packed bit representation such that three 16-bit floating point values are represented using 4 bytes. The bytes include unsigned 8-bit mantissas for the red, green and blue channels, plus a shared 8-bit exponent. + +NOTE 8 – When the exponent for each channel is the same, this representation is a more compact method to encode image data as compared to the representation where BPC is equal to 16 and PIXEL\_FORMAT is not equal to 32bppRGBE. + +- BPC equal to 32F indicates the "s8e23" format. The numerical value is encoded as a 4-byte ISO/IEC/IEEE 60559 floating point number in little-endian form. This encoding uses 1 sign bit, 8 exponent bits and 23 normalized mantissa bits. + +NOTE 9 – JPEG XR does not enable fully lossless compression for 32-bit data in general. The encoding and decoding algorithms use 32-bit computations, so some precision is lost during these calculations. A minimum of 22 bits and typically 24 bits or more precision is retained through the end-to-end encoding and decoding process. + +NOTE 10 – For some applications, the bounded range provided by an integer or fixed point representation may not be sufficient. Therefore, JPEG XR also supports a floating point numerical representation. Floating point formatting of image data will typically not compress as efficiently, but floating point capability provides a dramatically larger numerical range while maintaining high precision for small absolute values. + +### A.7.19 SPATIAL\_XFRM\_PRIMARY + +SPATIAL\_XFRM\_PRIMARY (when present) indicates a preferred spatial transformation that should be applied to the decoded image. The value of SPATIAL\_XFRM\_PRIMARY (when present) shall be in the range of 0 to 7, inclusive, in files conforming to this version of this Specification. Decoders conforming to this version of this Specification should interpret values outside the range from 0 to 7 as equivalent to the value 0. When SPATIAL\_XFRM\_PRIMARY is not present, its value shall be inferred to be equal to 0. + +The interpretation of the value of SPATIAL\_XFRM\_PRIMARY is the same as the interpretation specified in clause 8.3.8 for the syntax element SPATIAL\_XFRM\_SUBORDINATE. + +When the file format specified in this annex is used, the value of SPATIAL\_XFRM\_SUBORDINATE should be ignored. + +### A.7.20 IMAGE\_TYPE + +IMAGE\_TYPE indicates an attribute of an individual image in a multi-image file. When present, the value of IMAGE\_TYPE shall be in the range of 0 to 3, inclusive. All other values are reserved for future use by ITU-T | ISO/IEC. Decoders shall ignore the most significant 30 bits of IMAGE\_TYPE. + +If IMAGE\_TYPE & 1 is equal to 1, the accompanying image is indicated to be a "preview" image; otherwise the accompanying image is not indicated to be a preview image. A preview image is an alternate representation of another image in the file. The n-th preview image in the file is an alternate representation of the n-th image in the file that is not indicated to be a preview image, where n indicates the ordering in the sequence of IMAGE\_FILE\_DIRECTORY structures in the file. A preview image should be encoded using a reduced resolution or a reduced quantity of encoded data relative to another image in the file. + +NOTE 1 – The only constraint on ordering of images indicated to be a preview image and images not indicated to be a preview image aside is the ordering correspondence constraint. That is, the first preview image is a preview of the first image that is not a preview image; the second preview image is a preview of the second image that is not a preview image; and so on. Provided this constraint is met, preview images and images that are not preview images can otherwise be arranged in any order. + +A preview image shall be encoded using the mnemonic value of PIXEL\_FORMAT equal to the mnemonic value of PIXEL\_FORMAT for the corresponding image that is not indicated to be a preview image or a mnemonic value of PIXEL\_FORMAT from the following list: 8bppGray, 24bppBGR, 12bppYCC420, 16bppYCC422, 24bppYCC444, + +32bppCMYK, 32bppCMYKDIRECT, 24bpp3Channels, 32bpp4Channels, 40bpp5Channels, 48bpp6Channels, 56bpp7Channels, 64bpp8Channels, 32bppBGRA, 20bppYCC420Alpha, 24bppYCC422Alpha, 32bppYCC444Alpha, 40bppCMYKAlpha, 40bppCMYKDIRECTAlpha, 32bpp3ChannelsAlpha, 40bpp4ChannelsAlpha, 48bpp5ChannelsAlpha, 56bpp6ChannelsAlpha, 64bpp7ChannelsAlpha, 72bpp8ChannelsAlpha. + +NOTE 2 – A preview image is intended to be used to enable faster, reduced-complexity access to a basic representation of the image content. If multiple images in a file are indicated to be preview images, the first such image should ordinarily be used by applications. + +If $(\text{IMAGE\_TYPE} \gg 1) \& 1$ is equal to 1, the accompanying image is indicated to be an individual "page" of a sequence of "page" images in the file; otherwise the accompanying image is indicated not to be an individual page image of a sequence of page images in the file. When $(\text{IMAGE\_TYPE} \gg 1) \& 1$ is equal to 1, there should be more than one image in the file for which $(\text{IMAGE\_TYPE} \gg 1) \& 1$ is equal to 1. When $(\text{IMAGE\_TYPE} \gg 1) \& 1$ is equal to 1, there shall not be any images in the file for which $(\text{IMAGE\_TYPE} \gg 1) \& 1$ is equal to 0. + +All images in a sequence of pages shall have the same dimensions, as follows. + +- For all images with $\text{IMAGE\_TYPE} \& 1$ equal to 0 and $(\text{IMAGE\_TYPE} \gg 1) \& 1$ equal to 1, the value of $\text{IMAGE\_HEIGHT}$ and $\text{IMAGE\_WIDTH}$ shall be equal to the value of $\text{IMAGE\_HEIGHT}$ and $\text{IMAGE\_WIDTH}$ for any other image in the file with $\text{IMAGE\_TYPE} \& 1$ equal to 0 and $(\text{IMAGE\_TYPE} \gg 1) \& 1$ equal to 1. +- For all images with $\text{IMAGE\_TYPE} \& 1$ equal to 1 and $(\text{IMAGE\_TYPE} \gg 1) \& 1$ equal to 1, the value of $\text{IMAGE\_HEIGHT}$ and $\text{IMAGE\_WIDTH}$ shall be equal to the value of $\text{IMAGE\_HEIGHT}$ and $\text{IMAGE\_WIDTH}$ for any other image in the file with $\text{IMAGE\_TYPE} \& 1$ equal to 1 and $(\text{IMAGE\_TYPE} \gg 1) \& 1$ equal to 1. + +When a file contains only a single image, $\text{IMAGE\_TYPE}$ should not be present. + +### A.7.21 PTM\_COLOR\_INFO() + +The $\text{PTM\_COLOR\_INFO}()$ syntax structure (when present) is specified in Table A.7. + +$\text{PTM\_COLOR\_INFO}()$ shall not be present when either or both of the following conditions apply: + +- $\text{OUTPUT\_CLR\_FMT}$ is equal to CMYK, CMYKDIRECT, NCOMPONENT, or RGBE; or +- $\text{OUTPUT\_BIT\_DEPTH}$ is not equal to BD8, BD10, BD16, or BD16S. + +**Table A.7 – PTM\_COLOR\_INFO() syntax structure** + +| PTM_COLOR_INFO() { | Descriptor | Reference | +|---------------------------|-------------------|------------------| +| COLOR_PRIMARIES | u(8) | A.7.21.1 | +| TRANSFER_CHARACTERISTICS | u(8) | A.7.21.2 | +| MATRIX_COEFFICIENTS | u(8) | A.7.21.3 | +| RESERVED_K | u(7) | A.7.21.4 | +| FULL_RANGE_FLAG | u(1) | A.7.21.5 | +| } | | | + +#### A.7.21.1 COLOR\_PRIMARIES + +$\text{COLOR\_PRIMARIES}$ (when present) indicates the chromaticity coordinates of the colour primaries for the image as specified in Table A.8, in terms of the CIE 1931 definition of x and y as specified by ISO 11664-1. + +**Table A.8 – Interpretation of COLOR\_PRIMARIES syntax element** + +| Value | Primaries | Informative remark | +|-------|-------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 0 | Reserved | For future use by ITU-T ISO/IEC | +| 1 | primary      x      y
green        0.300    0.600
blue         0.150    0.060
red          0.640    0.330
white D65    0.3127   0.3290 | Rec. ITU-R BT.709-6
Rec. ITU-R BT.1361-0 (historical) conventional colour gamut system and extended colour gamut system
IEC 61966-2-1 (sRGB or sYCC)
IEC 61966-2-4 (xvYCC)
Annex B of SMPTE RP 177 | +| 2 | Unspecified | Image characteristics are unknown or are determined by the application. | +| 3 | Reserved | For future use by ITU-T ISO/IEC | +| 4 | primary      x      y
green        0.21      0.71
blue         0.14      0.08
red          0.67      0.33
white C      0.310     0.316 | Rec. ITU-R BT.470-6 System M (historical)
NTSC (1953)
FCC (2003), Title 47 | +| 5 | primary      x      y
green        0.29      0.60
blue         0.15      0.06
red          0.64      0.33
white D65    0.3127   0.3290 | Rec. ITU-R BT.470-6 System B, G (historical)
Rec. ITU-R BT.601-7 625
Rec. ITU-R BT.1358-0 625 (historical)
Rec. ITU-R BT.1700-0 625 PAL and 625 SECAM | +| 6 | primary      x      y
green        0.310     0.595
blue         0.155     0.070
red          0.630     0.340
white D65    0.3127   0.3290 | Rec. ITU-R BT.601-7 525
Rec. ITU-R BT.1358-1 (historical) 525 or 625
Rec. ITU-R BT.1700-0 NTSC
SMPTE ST 170:2004
(functionally the same as the value 7) | +| 7 | primary      x      y
green        0.310     0.595
blue         0.155     0.070
red          0.630     0.340
white D65    0.3127   0.3290 | SMPTE ST 240:1999
(functionally the same as the value 6) | +| 8 | Reserved | For future use by ITU-T ISO/IEC | + +| Value | Primaries | Informative remark | +|--------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------| +| 9 |
primary            x            y
green             0.170       0.797
blue              0.131       0.046
red                0.708       0.292
white D65        0.3127      0.3290
|
Rec. ITU-R BT.2020-2
Rec. ITU-R BT.2100-2
| +| 10-255 | Reserved | For future use by ITU-T ISO/IEC | + +### A.7.21.2 TRANSFER\_CHARACTERISTICS + +TRANSFER\_CHARACTERISTICS (when present), as specified in Table A.9, indicates the reference opto-electronic transfer characteristic function of the image colour components as a function of a real-valued linear optical intensity source input $v_{Lc}$ in the range of 0 to 1 or indicates the inverse of the reference electro-optical transfer characteristic function as a function of an output linear optical intensity $v_{Lo}$ with a nominal real-valued range of 0 to 1. For interpretation of entries in Table A.9 that are expressed in terms of multiple curve segments parameterized by the variable $\alpha$ over a region bounded by the variable $\beta$ or by the variables $\beta$ and $\gamma$ , the values of $\alpha$ and $\beta$ are defined to be the positive constants necessary for the curve segments that meet at the value $\beta$ to have continuity of value and continuity of slope at the value $\beta$ , and the value of $\gamma$ , when applicable, is defined to be the positive constant necessary for the associated curve segments to meet at the value $\gamma$ . For example, for transfer\_characteristics equal to 1, 6, or 11, $\alpha$ has the value $1 + 5.5 * \beta = 1.099\ 296\ 826\ 809\ 442\dots$ and $\beta$ has the value 0.018 053 968 510 807.... + +NOTE – Although the transfer characteristics equations found in Table A.9 are provided in the form of a mapping from a real-valued source signal intensity to a real-valued output value as might occur in an analogue image capture system, it is intended to be interpreted as guidance to aid in the rendering of the decoded image (by providing a model of a hypothetical capturing system) rather than as a description of the actual image scene signal capturing process. + +**Table A.9 – Interpretation of TRANSFER\_CHARACTERISTICS syntax element** + +| Value | Transfer characteristics | Informative remark | +|-------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 0 | Reserved | For future use by ITU-T ISO/IEC | +| 1 | $vV = \alpha * v_{Lc}^{0.45} - (\alpha - 1)$
for 1 \geq v_{Lc} \geq \beta
$vV = 4.500 * v_{Lc}$
for \beta > v_{Lc} \geq 0
|
Rec. ITU-R BT.709-6
Rec. ITU-R BT.1361-0 (historical)
conventional colour gamut system
Rec. ITU-R BT.2020-2
(functionally the same as the value 6)
| +| 2 | Unspecified | Image characteristics are unknown or are determined by the application. | +| 3 | Reserved | For future use by ITU-T ISO/IEC | +| 4 | Assumed display gamma 2.2 |
Rec. ITU-R BT.470-6 System M
(historical)
NTSC (1953)
FCC (2003), Title 47
| +| 5 | Assumed display gamma 2.8 | Rec. ITU-R BT.470-6 System B, G (historical) | +| 6 | $vV = \alpha * v_{Lc}^{0.45} - (\alpha - 1)$
for 1 \geq v_{Lc} \geq \beta
$vV = 4.500 * v_{Lc}$
for \beta > v_{Lc} \geq 0
|
Rec. ITU-R BT.601-7 525 or 625
Rec. ITU-R BT.1358-1 (2007)
(historical) 525 or 625
Rec. ITU-R BT.1700-0 NTSC
Rec. ITU-R BT.1700-0 625 PAL and 625
SECAM
SMPTE ST 170:2004
(functionally the same as the value 1)
| +| 7 | $vV = \alpha * v_{Lc}^{0.45} - (\alpha - 1)$
for 1 \geq v_{Lc} \geq \beta
$vV = 4.0 * v_{Lc}$
for \beta > v_{Lc} \geq 0
| SMPTE ST 240:1999 | +| 8 | $vV = v_{Lc}$
for 1 > v_{Lc} \geq 0
| Linear transfer characteristics | +| 9 | Reserved | For future use by ITU-T ISO/IEC | +| 10 | Reserved | For future use by ITU-T ISO/IEC | + +| Value | Transfer characteristics | Informative remark | +|---------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------| +| 11 | $vV = \alpha * vLc^{0.45} - (\alpha - 1)$ for $vLc \geq \beta$
$vV = 4.500 * vLc$ for $\beta > vLc > -\beta$
$vV = -\alpha * (-vLc)^{0.45} + (\alpha - 1)$ for $-\beta \geq vLc$ | IEC 61966-2-4 (xvYCC) | +| 12 | $vV = \alpha * vLc^{0.45} - (\alpha - 1)$ for $1.33 > vLc \geq \beta$
$vV = 4.500 * vLc$ for $\beta > vLc \geq -\gamma$
$vV = -(\alpha * (-4 * vLc)^{0.45} - (\alpha - 1)) \div 4$ for $-\gamma > vLc \geq -0.25$ | Rec. ITU-R BT.1361-0 (historical) extended colour gamut system | +| 13 | $vV = \alpha * vLc^{(1 \div 2.4)} - (\alpha - 1)$ for $1 > vLc \geq \beta$
$vV = 12.92 * vLc$ for $\beta > vLc \geq 0$ | IEC 61966-2-1 (sRGB or sYCC) | +| 14-15 | Reserved | For future use by ITU-T ISO/IEC | +| 16 | $vV = ((c1 + c2 * vLo^n) \div (1 + c3 * vLo^n))^m$ for all values of $vLo$
$c1 = c3 - c2 + 1 = 3424 \div 4096 = 0.835\ 937\ 5$
$c2 = 32 * 2413 \div 4096 = 18.851\ 562\ 5$
$c3 = 32 * 2392 \div 4096 = 18.687\ 5$
$m = 128 * 2523 \div 4096 = 78.843\ 75$
$n = 0.25 * 2610 \div 4096 = 0.159\ 301\ 757\ 812\ 5$
for which $vLo$ equal to 1 for peak white is ordinarily intended to correspond to a reference output luminance level of 10 000 candelas per square metre | SMPTE ST 2084:2014 for 10, 12, 14, and 16-bit systems
Rec. ITU-R BT.2100-2 perceptual quantization (PQ) system | +| 17 | Reserved | For future use by ITU-T ISO/IEC | +| 18 | $vV = a * \text{Ln}(12 * vLc - b) + c$ for $1 \geq vLc > 1 \div 12$
$vV = \text{Sqrt}(3) * vLc^{0.5}$ for $1 \div 12 \geq vLc \geq 0$
$a = 0.178\ 832\ 77, b = 0.284\ 668\ 92, c = 0.559\ 910\ 73$ | ARIB STD-B67
Rec. ITU-R BT.2100-2 hybrid log-gamma (HLG) system | +| 19..255 | Reserved | For future use by ITU-T ISO/IEC | + +### A.7.21.3 MATRIX\_COEFFICIENTS + +MATRIX\_COEFFICIENTS (when present) indicates the matrix coefficients associated with derivation of luma and chroma signals from the green, blue and red primaries, as specified using Table A.10 and the value of FULL\_RANGE\_FLAG as specified in the following. + +When OUTPUT\_CLR\_FMT is equal to YONLY, YUV420, YUV422, or YUV444, the value of MATRIX\_COEFFICIENTS shall not be equal to 0. + +When OUTPUT\_CLR\_FMT is equal to RGB, the value of MATRIX\_COEFFICIENTS shall not be equal to 1, 4, 5, 6, 7, 8, 9, 10, or 14. + +**Table A.10 – Interpretation of MATRIX\_COEFFICIENTS syntax element** + +| Value | Matrix | Informative remark | +|-------|------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 0 | RGB, GBR | No matrix transformation. See A.7.21.5.
IEC 61966-2-1 (sRGB) | +| 1 | $vKr = 0.2126; vKb = 0.0722$ | Rec. ITU-R BT.709-6
Rec. ITU-R BT.1361-0 (historical) conventional colour gamut system and extended colour gamut system
IEC 61966-2-1 (sYCC)
IEC 61966-2-4 xvYCC 709
Annex B of SMPTE RP 177 | +| 2 | Unspecified | Image characteristics are unknown or are determined by the application. | +| 3 | Reserved | For future use by ITU-T ISO/IEC | +| 4 | $vKr = 0.30; vKb = 0.11$ | FCC (2003) Title 47 | + +| | | | +|--------|---------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| 5 | $v_{Kr} = 0.299$ ; $v_{Kb} = 0.114$ | Rec. ITU-R BT.470-6 System B, G (historical)
Rec. ITU-R BT.601-7 625
Rec. ITU-R BT.1358-0 625 (historical)
Rec. ITU-R BT.1700-0 625 PAL and 625 SECAM
IEC 61966-2-4 xvYCC 601
(functionally the same as the value 6) | +| 6 | $v_{Kr} = 0.299$ ; $v_{Kb} = 0.114$ | Rec. ITU-R BT.601-7 525
Rec. ITU-R BT.1358-1 (historical) 525 or 625
Rec. ITU-R BT.1700-0 NTSC
SMPTE ST 170:2004
(functionally the same as the value 5) | +| 7 | $v_{Kr} = 0.212$ ; $v_{Kb} = 0.087$ | SMPTE ST 240:1999 | +| 8 | YCgCo | See A.7.21.5. | +| 9 | $v_{Kr} = 0.2627$ ; $v_{Kb} = 0.0593$ | Rec. ITU-R BT.2020-2 non-constant luminance system
Rec. ITU-R BT.2100-2 Y'CbCr
See A.7.21.5. | +| 10 | $v_{Kr} = 0.2627$ ; $v_{Kb} = 0.0593$ | Rec. ITU-R BT.2020-2 constant luminance system
See A.7.21.5. | +| 11-13 | Reserved | For future use by ITU-T ISO/IEC | +| 14 | IC T C P | Rec. ITU-R BT.2100-2 IC T C P
See A.7.21.5. | +| 15-255 | Reserved | For future use by ITU-T ISO/IEC | + +#### A.7.21.4 RESERVED\_K + +RESERVED\_K (when present) is a 7-bit syntax element that shall be equal to 0 in all codestreams conforming to this version of this Specification. All other values are reserved. Decoders conforming to this version of this Specification shall ignore the value of RESERVED\_K. + +NOTE – The purpose of the specification for decoders to ignore the value of RESERVED\_K is to enable the future definition of a backward-compatible usage of different values of this syntax element. + +#### A.7.21.5 FULL\_RANGE\_FLAG + +FULL\_RANGE\_FLAG (when present) is used together with TRANSFER\_CHARACTERISTICS and MATRIX\_COEFFICIENTS to provide an indication of the preferred interpretation of the image colour components. + +NOTE 1 – Although the equations found in the following are provided in the form of a mapping from source signals $E'_R$ , $E'_G$ and $E'_B$ to integer output values $i_R$ , $i_G$ , and $i_B$ or $Y$ , $C_b$ , and $C_r$ , they are intended to be interpreted as guidance to aid in the rendering of the decoded image (by providing a model of a hypothetical capturing system) rather than as a description of the actual image scene signal capturing process. + +These syntax elements are interpreted as follows: + +The value of valueBitDepth is calculated as follows: + +- If OUTPUT\_BITDEPTH is equal to BD8, the value of valueBitDepth is set equal to 8. +- Otherwise, if OUTPUT\_BITDEPTH is equal to BD10, the value of valueBitDepth is set equal to 10. +- Otherwise, if OUTPUT\_BITDEPTH is equal to BD16 or BD16S, the value of valueBitDepth is set equal to 16. +- Otherwise, no interpretation of FULL\_RANGE\_FLAG, TRANSFER\_CHARACTERISTICS, and MATRIX\_COEFFICIENTS is specified in this version of this Specification. + +The value of valueWhite is set equal to the result of $(1 \ll \text{valueBitDepth})$ taken as a real value. + +The value of chromaOffset is calculated as follows: + +- If OUTPUT\_BITDEPTH is equal to BD8, BD10 or BD16, the value of chromaOffset is set equal to $\text{valueWhite} / 2$ . +- Otherwise, if OUTPUT\_BITDEPTH is equal to BD16S, the value of chromaOffset is set equal to 0. + +The value of baseOffset is set equal to $\text{chromaOffset} - \text{valueWhite} / 2$ . + +$E_R$ , $E_G$ , and $E_B$ are defined as "linear-domain" real-valued signals based on the indicated colour primaries before application of the transfer characteristics function. + +Nominal black is considered to have the property $E_R = 0$ , $E_G = 0$ and $E_B = 0$ . + +Nominal white is considered to have the property $E_R = 1$ , $E_G = 1$ and $E_B = 1$ . + +The application of the transfer characteristics function is denoted by $(x)'$ for an argument $x$ . + +If MATRIX\_COEFFICIENTS is not equal to 14, the signals $E'_R$ , $E'_G$ , and $E'_B$ are determined by application of the transfer characteristics function as follows: + +$$\begin{aligned}E'_R &= (E_R)' \\E'_G &= (E_G)' \\E'_B &= (E_B)'\end{aligned}$$ + +In this case, the range of $E'_R$ , $E'_G$ , and $E'_B$ is specified as follows: + +- If TRANSFER\_CHARACTERISTICS is not equal to 11 or 12, $E'_R$ , $E'_G$ , and $E'_B$ are real numbers with values in the range of 0 to 1, inclusive. +- Otherwise (TRANSFER\_CHARACTERISTICS is equal to 11 or 12), $E'_R$ , $E'_G$ and $E'_B$ are real numbers with a larger range not specified in this Specification. + +Otherwise (MATRIX\_COEFFICIENTS is equal to 14), the "linear-domain" real-valued signals $E_L$ , $E_M$ , and $E_S$ are determined as follows: + +$$\begin{aligned}E_L &= (1688 * E_R + 2146 * E_G + 262 * E_B) \div 4096 \\E_M &= (683 * E_R + 2951 * E_G + 462 * E_B) \div 4096 \\E_S &= (99 * E_R + 309 * E_G + 3688 * E_B) \div 4096\end{aligned}$$ + +In this case, the signals $E'_L$ , $E'_M$ , and $E'_S$ are determined by application of the transfer characteristics function as follows: + +$$\begin{aligned}E'_L &= (E_L)' \\E'_M &= (E_M)' \\E'_S &= (E_S)'\end{aligned}$$ + +If MATRIX\_COEFFICIENTS is equal to 0 or 8, the following applies. + +- If FULL\_RANGE\_FLAG is equal to FALSE, the following equations apply. + +$$\begin{aligned}R_S &= \text{valueWhite} \div 256 * (219 * E'_R + 16) \\G_S &= \text{valueWhite} \div 256 * (219 * E'_G + 16) \\B_S &= \text{valueWhite} \div 256 * (219 * E'_B + 16)\end{aligned}$$ + +- Otherwise (FULL\_RANGE\_FLAG is equal to TRUE), the following equations apply. + +$$\begin{aligned}R_S &= (\text{valueWhite} - 1) * E'_R \\G_S &= (\text{valueWhite} - 1) * E'_G \\B_S &= (\text{valueWhite} - 1) * E'_B\end{aligned}$$ + +- If MATRIX\_COEFFICIENTS is equal to 0, the following equations apply. + +$$\begin{aligned}iR &= \text{Round}(R_S) + \text{baseOffset} \\iG &= \text{Round}(G_S) + \text{baseOffset} \\iB &= \text{Round}(B_S) + \text{baseOffset}\end{aligned}$$ + +- Otherwise (MATRIX\_COEFFICIENTS is equal to 8), the following equations apply. + +$$\begin{aligned}Y &= \text{Round}(0.5 * G_S + 0.25 * (R_S + B_S)) + \text{baseOffset} \\Cb &= \text{Round}(0.5 * G_S - 0.25 * (R_S + B_S)) + \text{chromaOffset} \\Cr &= \text{Round}(0.5 * (R_S - B_S)) + \text{chromaOffset}\end{aligned}$$ + +NOTE 2 – For purposes of the YCgCo nomenclature used in Table A.10, Cb and Cr of the foregoing equations may be referred to as Cg and Co, respectively. If OUTPUT\_BITDEPTH is equal to BD8, BD10 or BD16, the inverse conversion for the above three equations should be computed as + +$$\begin{aligned}t &= Y - (Cb - \text{chromaOffset}) \\iG &= t + 2 * (Cb - \text{chromaOffset}) \\iB &= t - (Cr - \text{chromaOffset}) \\iR &= iB + 2 * (Cr - \text{chromaOffset})\end{aligned}$$ + +Otherwise, if OUTPUT\_BITDEPTH is equal to BD16S, the inverse conversion for the above three equations should be computed as. + +$$\begin{aligned}t &= Y - (Cb \gg 1) \\iG &= t + Cb\end{aligned}$$ + +$$iB = t - (Cr \gg 1)$$ + +$$iR = iB + Cr$$ + +Otherwise, if MATRIX\_COEFFICIENTS is equal to 1, 4, 5, 6, 7, 9, 10, or 14, the following applies: + +- If MATRIX\_COEFFICIENTS is equal to 1, 4, 5, 6, 7, or 9, the following equations apply. + +$$E'_Y = vKr * E'_R + (1 - vKr - vKb) * E'_G + vKb * E'_B$$ + +$$E'_{PB} = 0.5 * (E'_B - E'_Y) \div (1 - vKb)$$ + +$$E'_{PR} = 0.5 * (E'_R - E'_Y) \div (1 - vKr)$$ + +NOTE 3 – $E'_Y$ is real-valued with the value 0 associated with nominal black and the value 1 associated with nominal white. $E'_{PB}$ and $E'_{PR}$ are real-valued with the value 0 associated with both nominal black and nominal white. When TRANSFER\_CHARACTERISTICS is not equal to 11 or 12, $E'_Y$ is real-valued with values in the range of 0 to 1. When TRANSFER\_CHARACTERISTICS is not equal to 11 or 12, $E'_{PB}$ and $E'_{PR}$ are real-valued with values in the range of $-0.5$ to $0.5$ . When TRANSFER\_CHARACTERISTICS is equal to 11 (IEC 61966-2-4) or 12 [ITU-R BT.1361-0 (historical) extended colour gamut system], $E'_Y$ , $E'_{PB}$ and $E'_{PR}$ are real-valued with a larger range not specified in this Specification. + +- Otherwise, if MATRIX\_COEFFICIENTS is equal to 10, the following applies. + +$$E_Y = vKr * E_R + (1 - vKr - vKb) * E_G + vKb * E_B$$ + +$$E'_Y = (E_Y)'$$ + +$$E'_{PB} = (E'_B - E'_Y) \div (2 * N_B) \quad \text{for } -N_B \leq E'_B - E'_Y \leq 0$$ + +$$E'_{PB} = (E'_B - E'_Y) \div (2 * P_B) \quad \text{for } 0 < E'_B - E'_Y \leq P_B$$ + +$$E'_{PR} = (E'_R - E'_Y) \div (2 * N_R) \quad \text{for } -N_R \leq E'_R - E'_Y \leq 0$$ + +$$E'_{PR} = (E'_R - E'_Y) \div (2 * P_R) \quad \text{for } 0 < E'_R - E'_Y \leq P_R$$ + +NOTE 4 – In this case, $E_Y$ is defined from the "linear-domain" signals for $E_R$ , $E_G$ and $E_B$ , prior to application of the transfer characteristics function, which is then applied to produce the signal $E'_Y$ . $E_Y$ and $E'_Y$ are real values with the value 0 associated with nominal black and the value 1 associated with nominal white. + +where the constants $N_B$ , $P_B$ , $N_R$ and $P_R$ are determined by application of the transfer characteristics function to expressions involving the constants $vKb$ and $vKr$ as follows: + +$$N_B = (1 - vKb)'$$ + +$$P_B = 1 - (vKb)'$$ + +$$N_R = (1 - vKr)'$$ + +$$P_R = 1 - (vKr)'$$ + +- Otherwise (MATRIX\_COEFFICIENTS is equal to 14), the following applies: + +$$E'_Y = 0.5 * (E'_L + E'_M)$$ + +$$E'_{PB} = (6610 * E'_L - 13613 * E'_M + 7003 * E'_S) \div 4096$$ + +$$E'_{PR} = (17933 * E'_L - 17390 * E'_M - 543 * E'_S) \div 4096$$ + +NOTE 5 – In this case, for purposes of the ICTCF nomenclature used in Table A.10, $E'_Y$ , $E'_{PB}$ , and $E'_{PR}$ may be referred to as $I$ , $C_T$ , and $C_P$ , respectively. + +- If FULL\_RANGE\_FLAG is equal to FALSE and OUTPUT\_BITDEPTH is equal to BD8, BD10 or BD16, $Y$ , $Cb$ and $Cr$ are related to $E'_Y$ , $E'_{PB}$ and $E'_{PR}$ by the following. + +$$Y = \text{Clip}(\text{Round}(\text{valueWhite} \div 256 * (219 * E'_Y + 16)), 0, \text{valueWhite} - 1) + \text{baseOffset}$$ + +$$Cb = \text{Clip}(\text{Round}(\text{valueWhite} \div 256 * (224 * E'_{PB}) + \text{chromaOffset}), 0, \text{valueWhite} - 1)$$ + +$$Cr = \text{Clip}(\text{Round}(\text{valueWhite} \div 256 * (224 * E'_{PR}) + \text{chromaOffset}), 0, \text{valueWhite} - 1)$$ + +- If FULL\_RANGE\_FLAG is equal to FALSE and OUTPUT\_BITDEPTH is equal to BD16S, $Y$ , $Cb$ and $Cr$ are related to $E'_Y$ , $E'_{PB}$ and $E'_{PR}$ by the following. + +$$Y = \text{Round}(\text{valueWhite} \div 256 * (219 * E'_Y + 16)) + \text{baseOffset}$$ + +$$Cb = \text{Round}(\text{valueWhite} \div 256 * (224 * E'_{PB}) + \text{chromaOffset})$$ + +$$Cr = \text{Round}(\text{valueWhite} \div 256 * (224 * E'_{PR}) + \text{chromaOffset})$$ + +- Otherwise (FULL\_RANGE\_FLAG is equal to TRUE), $Y$ , $Cb$ and $Cr$ are related to $E'_Y$ , $E'_{PB}$ and $E'_{PR}$ by the following. + +$Y = \text{Round}((\text{valueWhite} - 1) * E'_Y) + \text{baseOffset}$ + +$Cb = \text{Round}((\text{valueWhite} - 1) * E'_{PB} + \text{chromaOffset})$ + +$Cr = \text{Round}((\text{valueWhite} - 1) * E'_{PR} + \text{chromaOffset})$ + +Otherwise, no interpretation of FULL\_RANGE\_FLAG, TRANSFER\_CHARACTERISTICS, and MATRIX\_COEFFICIENTS is specified in this version of this Specification. + +- When OUTPUT\_CLR\_FMT is equal to YONLY, the Cb and Cr variables are discarded. + +### A.7.22 PROFILE\_LEVEL\_CONTAINER() + +PROFILE\_LEVEL\_CONTAINER() (when present) has the same syntax and semantics as PROFILE\_LEVEL\_INFO() in 8.6. + +### A.7.23 IMAGE\_WIDTH + +IMAGE\_WIDTH specifies the width of the image in units of sample columns after decoding and before application of the spatial transformation indicated by the (actual or inferred) value of SPATIAL\_XFRM\_PRIMARY. The value of IMAGE\_WIDTH shall be equal to WIDTH\_MINUS1 + 1. + +NOTE – When ALPHA\_OFFSET is present, the value of IMAGE\_WIDTH is equal to the value of WIDTH\_MINUS1 + 1 from the CODED\_IMAGE() syntax structure at the position specified by ALPHA\_OFFSET and is also equal to the value of WIDTH\_MINUS1 + 1 from the CODED\_IMAGE() syntax structure at the position specified by IMAGE\_OFFSET. + +### A.7.24 IMAGE\_HEIGHT + +IMAGE\_HEIGHT specifies the height of the image in units of sample rows after decoding and before application of the spatial transformation indicated by the (actual or inferred) value of SPATIAL\_XFRM\_PRIMARY. The value of IMAGE\_HEIGHT shall be equal to HEIGHT\_MINUS1 + 1. + +NOTE – When ALPHA\_OFFSET is present, the value of IMAGE\_HEIGHT is equal to the value of HEIGHT\_MINUS1 + 1 from the CODED\_IMAGE() syntax structure at the position specified by ALPHA\_OFFSET and is also equal to the value of HEIGHT\_MINUS1 + 1 from the CODED\_IMAGE() syntax structure at the position specified by IMAGE\_OFFSET. + +### A.7.25 WIDTH\_RESOLUTION + +WIDTH\_RESOLUTION (when present) indicates a nominal width of the associated image after decoding and before application of the spatial transformation indicated by the (actual or inferred) value of SPATIAL\_XFRM\_PRIMARY. WIDTH\_RESOLUTION is in units of columns per inch (columns per 2.54 cm). When WIDTH\_RESOLUTION is equal to 0 or is not present, a value of 96 columns per inch should be inferred. The nominal width of the image (before application of the spatial transformation indicated by SPATIAL\_XFRM\_PRIMARY) is indicated to be $\text{IMAGE\_WIDTH} \div \text{WIDTH\_RESOLUTION}$ inches. + +NOTE – The nominal width may be interpreted as an indication of a suggested width for printing or display of the image. The combination of IMAGE\_WIDTH, IMAGE\_HEIGHT, WIDTH\_RESOLUTION and HEIGHT\_RESOLUTION may be used to determine an indication of a suggested display or printing aspect ratio for the image. + +### A.7.26 HEIGHT\_RESOLUTION + +HEIGHT\_RESOLUTION (when present) indicates a nominal height of the associated image after decoding and before application of the spatial transformation indicated by the (actual or inferred) value of SPATIAL\_XFRM\_PRIMARY. HEIGHT\_RESOLUTION is in units of rows per inch (rows per 2.54 cm). When HEIGHT\_RESOLUTION is equal to 0 or is not present, a value of 96 rows per inch should be inferred. The nominal height of the image (before application of the spatial transformation indicated by SPATIAL\_XFRM\_PRIMARY) is indicated to be $\text{IMAGE\_HEIGHT} \div \text{HEIGHT\_RESOLUTION}$ inches. + +NOTE – The nominal height may be interpreted as an indication of a suggested height for printing or display of the image. The combination of IMAGE\_WIDTH, IMAGE\_HEIGHT, WIDTH\_RESOLUTION and HEIGHT\_RESOLUTION may be used to determine an indication of a suggested display or printing aspect ratio for the image. + +### A.7.27 IMAGE\_OFFSET + +IMAGE\_OFFSET specifies the byte position, relative to the beginning of the file, of the start of a CODED\_IMAGE() syntax structure in the file (see 8.2) containing the primary image plane in the IMAGE\_FILE\_DIRECTORY(). When ALPHA\_OFFSET is not present, but an alpha plane is present, the CODED\_IMAGE() syntax structure at the position specified by IMAGE\_OFFSET also contains the alpha image plane. + +### A.7.28 IMAGE\_BYTE\_COUNT + +IMAGE\_BYTE\_COUNT specifies the quantity of the image codestream data in the file as follows. + +- If IMAGE\_BYTE\_COUNT is not equal to 0, the quantity of the image codestream data in the file is indicated to be equal to the value of IMAGE\_BYTE\_COUNT. +- Otherwise (IMAGE\_BYTE\_COUNT is equal to 0), the quantity of image codestream data in the file is indicated to be equal to FileSizeInBytes – IMAGE\_OFFSET. + +NOTE – When IMAGE\_BYTE\_COUNT is equal to 0, no additional syntax structures are present in the file after the CODED\_IMAGE() syntax structure at the position specified by IMAGE\_OFFSET. + +### A.7.29 ALPHA\_OFFSET + +ALPHA\_OFFSET (when present) specifies the byte position, relative to the beginning of the file, of the start of a CODED\_IMAGE() syntax structure for the alpha plane of the image in the IMAGE\_FILE\_DIRECTORY(). When PIXEL\_FORMAT does not indicate the presence of an alpha channel, ALPHA\_OFFSET shall not be present. + +When PIXEL\_FORMAT indicates the presence of an alpha channel, the form of the encoding of the alpha channel is specified as follows. + +- If ALPHA\_OFFSET is present, the alpha channel is present in a separate CODED\_IMAGE() syntax structure of the same IMAGE\_FILE\_DIRECTORY() syntax structure from the CODED\_IMAGE() for the primary image plane. In this case, the syntax element ALPHA\_IMAGE\_PLANE\_FLAG for the CODED\_IMAGE() syntax structure at the position specified by IMAGE\_OFFSET (A.7.27) shall be equal to zero and the syntax element ALPHA\_IMAGE\_PLANE\_FLAG for the CODED\_IMAGE() syntax structure at the position specified by ALPHA\_OFFSET shall be equal to 1. In this case, the alpha image plane is a separate alpha image plane. +- Otherwise, the alpha channel is present within the same CODED\_IMAGE() syntax structure as the primary image plane and the syntax element ALPHA\_IMAGE\_PLANE\_FLAG shall be equal to one. In this case, the alpha image plane is an interleaved alpha image plane. + +When ALPHA\_BYTE\_COUNT is present, ALPHA\_OFFSET shall also be present. + +### A.7.30 ALPHA\_BYTE\_COUNT + +ALPHA\_BYTE\_COUNT (when present) specifies the quantity of the alpha plane codestream data in the file. When ALPHA\_OFFSET is present, ALPHA\_BYTE\_COUNT shall also be present. + +### A.7.31 IMAGE\_BAND\_PRESENCE + +IMAGE\_BAND\_PRESENCE (when present) indicates which frequency bands are present in the accompanying image data as specified in Table A.11. When IMAGE\_BAND\_PRESENCE is not present, its value shall be inferred to be equal to 0. The value of IMAGE\_BAND\_PRESENCE, when present, shall be equal to the value of BANDS\_PRESENT of the primary image plane of the CODED\_IMAGE() syntax structure at the position specified by IMAGE\_OFFSET. + +**Table A.11 – Interpretation of IMAGE\_BAND\_PRESENCE and ALPHA\_BAND\_PRESENCE** + +| IMAGE_BAND_PRESENCE
or
ALPHA_BAND_PRESENCE | Bands present | +|--------------------------------------------------|--------------------------| +| 0 | DC, LP, HP, and Flexbits | +| 1 | DC, LP, and HP only | +| 2 | DC and LP only | +| 3 | DC only | + +### A.7.32 ALPHA\_BAND\_PRESENCE + +ALPHA\_BAND\_PRESENCE (when present) indicates which frequency bands are represented in the accompanying alpha channel data as specified in Table A.11. When ALPHA\_OFFSET is not present, ALPHA\_BAND\_PRESENCE shall not be present. When ALPHA\_OFFSET is present and ALPHA\_BAND\_PRESENCE is not present, its value shall be inferred to be equal to 0. If the alpha channel is present as an interleaved alpha image plane, the value of ALPHA\_BAND\_PRESENCE, when present, shall be equal to the value of BANDS\_PRESENT of the alpha image plane of the CODED\_IMAGE() syntax structure at the position specified by IMAGE\_OFFSET. If the alpha channel is present as a separate alpha image plane, the value of ALPHA\_BAND\_PRESENCE, when present, shall be equal to the value of BANDS\_PRESENT of the CODED\_IMAGE() syntax structure at the position specified by ALPHA\_OFFSET. + +### A.7.33 PADDING\_DATA + +PADDING\_DATA (when present) consists of a string of byte values of the indicated quantity. PADDING\_DATA is formatted as follows. + +- The first byte shall be equal to 0x1C. + +- The second byte (when present) shall be equal to 0xEA. +- The remaining bytes (when present) shall be equal to 0 in all codestreams conforming to this version of this Specification. Decoders conforming to this version of this Specification shall ignore the value of the remaining bytes. + +NOTE – One use for PADDING\_DATA is to reserve space within a file for potential later replacement by other data. + +## Annex B + +### Profiles and levels + +(This annex forms an integral part of this Recommendation | International Standard.) + +#### B.1 General + +This annex specifies sets of constraints on the syntax and values of derived parameters that enhance interoperability by establishing bounds on the capabilities that are needed for the decoding of images encoded according to this Recommendation | International Standard. These sets of constraints are classified into profile and level constraints. + +NOTE – Typically, a profile constraint restricts the use of algorithmic features, while a level constraint restricts the range of values in a manner intended to constrain resource requirements such as memory storage capacity. + +Decoders that claim conformance to a specified profile of this Specification at some specified level shall be capable of decoding any coded image that conforms to all specified constraints for the specified profile at the specified level or any lower specified level and has such conformance expressed syntactically as specified in this annex. + +Conformance of a coded image to a particular profile and level is expressed by a PROFILE\_LEVEL\_INFO( ) syntax structure. When the PROFILE\_LEVEL\_INFO( ) syntax structure is not present, the following inference rules apply: + +- PROFILE\_IDC shall be inferred to be equal to 111. +- LEVEL\_IDC shall be inferred to be equal to 255. + +#### B.2 Profiles + +##### B.2.1 Sub-baseline profile + +The sub-baseline profile is defined as the set of coded image syntax that has LONG\_WORD\_FLAG set equal to FALSE, has OVERLAP\_MODE set equal to either 0 or 1, and that is consistent with the use of the following PIXEL\_FORMAT mnemonic values (specified in Table A.6): 24bppRGB, 24bppBGR, 32bppBGR, 8bppGray, BlackWhite, 16bppBGR555, 16bppBGR565 or 32bppBGR101010. + +NOTE 1 – Although this constraint is specified in terms of concepts defined in Annex A, it also applies when the file format specified in Annex A is not in use. Concepts specified in Annex A are used in this annex only as a reference to establish the set of features supported by the profiles specified in this annex. + +NOTE 2 – Encoders may need to set SCALED\_FLAG equal to 0 for 32bppBGR101010 encoding to avoid exceeding the dynamic range constraints imposed when LONG\_WORD\_FLAG is equal to FALSE. + +Conformance of a coded image to the sub-baseline profile is indicated by PROFILE\_IDC equal to 44. The value 44 for PROFILE\_IDC shall not be used in a PROFILE\_LEVEL\_INFO( ) syntax structure unless the associated coded image conforms to the constraints specified for the sub-baseline profile. + +Values of PROFILE\_IDC that are less than 44 may additionally be interpreted by decoders as expressing conformance of the associated coded image to the sub-baseline profile. + +##### B.2.2 Baseline profile + +The baseline profile is defined as the set of coded image syntax that is consistent with the use of the following PIXEL\_FORMAT mnemonic values (specified in Table A.6): 24bppRGB, 24bppBGR, 32bppBGR, 48bppRGB, 48bppRGBFixedPoint, 64bppRGBFixedPoint, 8bppGray, 16bppGray, 16bppGrayFixedPoint, BlackWhite, 16bppBGR555, 16bppBGR565 or 32bppBGR101010. + +NOTE – Although this constraint is specified in terms of concepts defined in Annex A, it also applies when the file format specified in Annex A is not in use. Concepts specified in Annex A are used in this annex only as a reference to establish the set of features supported by the profiles specified in this annex. + +Conformance of a coded image to the baseline profile is indicated by PROFILE\_IDC equal to 55. The value 55 for PROFILE\_IDC shall not be used in a PROFILE\_LEVEL\_INFO( ) syntax structure unless the associated coded image conforms to the constraints specified for the baseline profile. + +Values of PROFILE\_IDC that are less than 55 may additionally be interpreted by decoders as expressing conformance of the associated coded image to the baseline profile. + +### B.2.3 Main profile + +The Main profile is defined as the set of coded image syntax that is consistent with the use of the following PIXEL\_FORMAT mnemonic values (specified in Table A.6): 24bppRGB, 24bppBGR, 32bppBGR, 48bppRGB, 48bppRGBFixedPoint, 48bppRGBHalf, 96bppRGBFixedPoint, 64bppRGBFixedPoint, 64bppRGBHalf, 128bppRGBFixedPoint, 128bppRGBFloat, 32bppBGRA, 64bppRGBA, 64bppRGBAFixedPoint, 64bppRGBAHalf, 128bppRGBAFixedPoint, 128bppRGBAFloat, 32bppPBGRA, 64bppPRGBA, 128bppPRGBAFloat, 32bppCMYK, 40bppCMYKAlpha, 64bppCMYK, 80bppCMYKAlpha, 24bpp3Channels, 32bpp4Channels, 40bpp5Channels, 48bpp6Channels, 56bpp7Channels, 64bpp8Channels, 32bpp3ChannelsAlpha, 40bpp4ChannelsAlpha, 48bpp5ChannelsAlpha, 56bpp6ChannelsAlpha, 64bpp7ChannelsAlpha, 72bpp8ChannelsAlpha, 48bpp3Channels, 64bpp4Channels, 80bpp5Channels, 96bpp6Channels, 112bpp7Channels, 128bpp8Channels, 64bpp3ChannelsAlpha, 80bpp4ChannelsAlpha, 96bpp5ChannelsAlpha, 112bpp6ChannelsAlpha, 128bpp7ChannelsAlpha, 144bpp8ChannelsAlpha, 8bppGray, 16bppGray, 16bppGrayFixedPoint, 16bppGrayHalf, 32bppGrayFixedPoint, 32bppGrayFloat, BlackWhite, 16bppBGR555, 16bppBGR565, 32bppBGR101010 or 32bppRGBE. + +NOTE – Although this constraint is specified in terms of concepts defined in Annex A, it also applies when the file format specified in Annex A is not in use. Concepts specified in Annex A are used in this annex only as a reference to establish the set of features supported by the profiles specified in this annex. + +Conformance of a coded image to the Main profile is indicated by PROFILE\_IDC equal to 66. The value 66 for PROFILE\_IDC shall not be used in a PROFILE\_LEVEL\_INFO() syntax structure unless the associated coded image conforms to the constraints specified for the Main profile. + +Values of PROFILE\_IDC that are less than 66 may additionally be interpreted by decoders as expressing conformance of the associated coded image to the Main profile. + +### B.2.4 Advanced profile + +The Advanced profile is defined as the set of all coded image syntax that is specified in this Specification. + +NOTE – Some image codestreams that conform to the Advanced profile cannot be stored in a file as specified in Annex A due to the lack of specification of any PIXEL\_FORMAT value in Annex A that is consistent with the content of the image codestream. For example, a coded image with NumComponents equal to 32 cannot be stored in a file as specified in Annex A. + +Conformance of a coded image to the Advanced profile is indicated by PROFILE\_IDC equal to 111. The value 111 for PROFILE\_IDC shall not be used in a PROFILE\_LEVEL\_INFO() syntax structure unless the associated coded image conforms to the constraints specified for the Advanced profile. + +Values of PROFILE\_IDC that are less than 111 may additionally be interpreted by decoders as expressing conformance of the associated coded image to the Advanced profile. + +### B.2.5 Reserved values of PROFILE\_IDC + +The value of PROFILE\_IDC in a PROFILE\_LEVEL\_INFO() syntax structure shall not be equal to any value other than 44, 55, 66 or 111. Such other values are reserved for future use by ITU-T | ISO/IEC. + +## B.3 Levels + +Conformance of a coded image to a particular level is indicated by LEVEL\_IDC equal to the value shown in the "Level" column of Table B.1. + +For a value of LEVEL\_IDC specified by the "Level" column of Table B.1, the associated coded image shall obey the following constraints using values obtained from the corresponding row of Table B.1. + +- WIDTH\_MINUS1 + LEFT\_MARGIN + RIGHT\_MARGIN shall be less than MaxImageDimension. +- HEIGHT\_MINUS1 + TOP\_MARGIN + BOTTOM\_MARGIN shall be less than MaxImageDimension. +- NUM\_HOR\_TILES\_MINUS1 shall be less than MaxDimensionInTiles. +- NUM\_VER\_TILES\_MINUS1 shall be less than MaxDimensionInTiles. +- TILE\_WIDTH\_IN\_MB[n] \* 16, when present, shall be less than MaxTileDimension for all values of n greater than or equal to 0 and less than NUM\_VER\_TILES\_MINUS1. +- (MBWidth – LeftMBIndexOfTile[NUM\_VER\_TILES\_MINUS1]) \* 16 shall be less than MaxTileDimension. +- TILE\_HEIGHT\_IN\_MB[n] \* 16, when present, shall be less than MaxTileDimension for all values of n greater than or equal to 0 and less than NUM\_HOR\_TILES\_MINUS1. +- (MBHeight – TopMBIndexOfTile[NUM\_HOR\_TILES\_MINUS1]) \* 16 shall be less than MaxTileDimension. +- When LEVEL\_IDC is not equal to 255, the value of ImageBufferBytes(valNC) as specified in Table B.2 shall be less than MaxBufferSizeInBytes, where the value of valNC is determined as follows. + +- If LEVEL\_IDC is within a PROFILE\_LEVEL\_CONTAINER( ) syntax structure, valNC is set equal to the value in the "NC" column of Table A.6 for the corresponding value of PIXEL\_FORMAT. +- Otherwise, if ALPHA\_IMAGE\_PLANE\_FLAG is equal to FALSE, valNC is set equal to the value returned by DetermineNumComponents( ) for the primary image plane. +- Otherwise, valNC is set equal to the value returned by DetermineNumComponents( ) for the primary image plane plus 1. + +When LEVEL\_IDC is less than or equal to 128, SHORT\_HEADER\_FLAG shall be equal to 1. + +**Table B.1 – Parameters of levels of conformance to this Specification** + +| Level | MaxImageDimension | MaxDimensionInTiles | MaxTileDimension | MaxBufferSizeInBytes | +|-------|-------------------|---------------------|------------------|----------------------| +| 4 | $2^{10}$ | $2^4$ | $2^{10}$ | $2^{22}$ | +| 8 | $2^{11}$ | $2^5$ | $2^{11}$ | $2^{24}$ | +| 16 | $2^{12}$ | $2^6$ | $2^{12}$ | $2^{26}$ | +| 32 | $2^{13}$ | $2^7$ | $2^{12}$ | $2^{28}$ | +| 64 | $2^{14}$ | $2^8$ | $2^{12}$ | $2^{30}$ | +| 128 | $2^{16}$ | $2^{10}$ | $2^{12}$ | $2^{32}$ | +| 255 | $2^{32}$ | $2^{12}$ | $2^{32}$ | Not applicable | + +NOTE – When LEVEL\_IDC is equal to 255 and TILING\_FLAG is equal to TRUE, the number of bits used for the syntax elements TILE\_WIDTH\_IN\_MB[n] and TILE\_HEIGHT\_IN\_MB[n] cannot express a value greater than $2^{16}-1$ . + +**Table B.2 – Pseudocode for function ImageBufferBytes(valNC)** + +| ImageBufferBytes(valNC) { | Reference | +|----------------------------------------------------------------------------------------------------|------------------| +| numBytes = 0 | | +| if (OUTPUT_BITDEPTH == BD8) | | +| numBytes = valNC * ExtendedWidth[0] * ExtendedHeight[0] | | +| else if ((OUTPUT_BITDEPTH == BD16) (OUTPUT_BITDEPTH == BD16S)
(OUTPUT_BITDEPTH == BD16F)) | | +| numBytes = 2 * valNC * ExtendedWidth[0] * ExtendedHeight[0] | | +| else if ((OUTPUT_BITDEPTH == BD32S) (OUTPUT_BITDEPTH == BD32F)) | | +| numBytes = 4 * valNC * ExtendedWidth[0] * ExtendedHeight[0] | | +| else if ((OUTPUT_BITDEPTH == BD1WHITE1)
(OUTPUT_BITDEPTH == BD1BLACK1)) | | +| numBytes = ExtendedWidth[0] * ExtendedHeight[0] / 8 | | +| else if ((OUTPUT_BITDEPTH == BD5) (OUTPUT_BITDEPTH == BD565)) | | +| numBytes = 2 * ExtendedWidth[0] * ExtendedHeight[0] | | +| else /* In the remaining case, OUTPUT_BITDEPTH is equal to BD10 */ | | +| if (OUTPUT_CLR_FMT == RGB) | | +| numBytes = 4 * ExtendedWidth[0] * ExtendedHeight[0] | | +| else | | +| numBytes = 2 * valNC * ExtendedWidth[0] * ExtendedHeight[0] | | +| return numBytes | | +| } | | + +The value of LEVEL\_IDC in a PROFILE\_LEVEL\_INFO( ) syntax structure shall not be equal to any value other than a value specified in Table B.1. Such other values are reserved for future use by ITU-T | ISO/IEC. Any reserved value of LEVEL\_IDC that is lower than some value that is specified in Table B.1 shall be interpreted by decoders as expressing conformance of the associated image to the higher value of LEVEL\_IDC that is specified in Table B.1 (in the context of the associated value of PROFILE\_IDC). + +## Annex C + +### Colour imagery representation and colour management + +(This annex does not form an integral part of this Recommendation | International Standard.) + +#### C.1 Background information + +While it might be theoretically possible to agree on one method for assigning specific numerical values to real world colours, doing so is not practical. Since any specific device has its own limited range for colour reproduction, the device's range may be a small portion of the agreed-upon universal colour range. As a result, such an approach is an extremely inefficient use of the available numerical values, especially when using only 8 bits (or 256 unique values) per channel. + +To represent pixel values as efficiently as possible, devices use a numeric encoding optimized for their own range of possible colours or gamut. In addition, a colour profile is often provided that describes the numeric encoding for the specific device relative to some pre-defined reference standard. For example, a colour profile may include a specification of a non-linear transformation from the range of integer values to the luminance (or radiance) of the colour values as reproduced. This non-linear transformation is called the colour component transfer function (CCTF). In some cases, it may be possible to specify the CCTF using a power function with a single numerical value specifying the exponent or "gamma". The term "gamma" is also sometimes used more informally to refer to any CCTF, although this terminology is not strictly correct. Colour profiles deal with all aspects of the colour interpretation of digital values, and in addition to specifying the CCTF, specify the relations between device values and the profile connection space (PCS) coordinates, which in the case of ICC profiles are based on the CIE 1931 2° standard observer specified in ISO 11664-1. Colour profiles may provide additional information about the encoded image, such as the viewing conditions or image state. ICC profiles also provide a transform to a standard reference medium for interoperability. Colour profiles make it possible to convert image data between different colour encodings, thereby controlling the capture and production of colours using a variety of devices. This science is known as "colour management". + +Most common photo and image formats use an 8-bit or 16-bit unsigned integer value to represent some function of the intensity of each colour channel. The minimum value (0) often represents the minimum intensity in a single channel. The encoding of black is achieved in such usage when all channels are zero. The maximum value ( $2^n - 1$ for an unsigned bit depth of $n$ bits) often represents 100% intensity or full saturation of an individual channel. When all channels have this maximal value, this typically corresponds to an encoding of white. Various alternative encoding conventions also exist, such as several colour representations specified by the ITU-R for which black may be represented by the value 16 and white may be represented by the value 235 for each colour channel. + +The exact meaning of "black", "full saturation" and "white" as well as the specific colours produced by all the intermediate numerical steps in the numerical representation range is dependent on how these values are initially created or captured or how these values are rendered. Different source or destination devices (including cameras, scanners, displays or printers) may use different numerical values to represent the same "real world" colour. + +The process of converting colours, and their numerical representation, to the ranges covered by different devices creates some significant complications. First, colours optimized for the gamut of the source device are re-optimized for the gamut of the destination device. This process involves some artistic judgment, as there is no single correct method. Then, the converted colours are encoded using the destination device encoding. + +In addition, any intermediate image processing has the potential to produce values that extend beyond the black (low limit) or white (high limit) point of the particular colour encoding, often resulting in these calculated values being clipped to the associated limits. A working space colour encoding with a limited numerical range can cause values to be corrupted during intermediate calculations, even though subsequent image processing may bring these values back within the displayable (black to white) range of the target rendering destination. Because of this issue, many modern image processing software applications use a much larger gamut, including representation of numerical values of greater bit depths, for all intermediate image processing calculations. (It is not uncommon to use 32-bit floating point values for intermediate calculations, minimizing any image corruption caused by rounding errors and clipping at the range limits during the intermediate steps of image processing calculations.) However, most common image formats today require that this image data be converted back to a range-limited, unsigned integer representation, limited to the gamut as defined by a specific colour profile. So once again, the potential for data corruption exists. + +#### C.2 Colour interpretation in the JPEG XR context + +To address these challenges, JPEG XR provides a much more flexible approach to the numerical encoding of image data by supporting a wide range of different pixel formats. JPEG XR supports three basic types of numerical encoding, each at a variety of bit depths – specifically, these types are unsigned integer, fixed-point, and floating point representations. + +A variety of pixel formats is supported by JPEG XR using unsigned integer representations in bit depths of 8 and 16, as well as smaller bit depths for specialized applications. JPEG XR also supports a number of additional pixel formats that avoid some problematic aspects involved in the unsigned integer representations. + +ICC profile data as specified by ICC.1:2001-04 (ICC version 2.4.0.0) or ISO 15076-1:2010 (ICC version 4.3.0.0) can provide at least one unambiguous interpretation of the colours associated with encoded image data. Multiple interpretations may be provided using different rendering intents. The file format specified in Annex A supports the inclusion of ICC profile data for imagery encoded according to this Specification by allowing the use of the field tag value 0x8773, which is specified in ICC.1:2001-04 and ISO 15076-1:2010 for use in tag-based file formats for embedding of ICC profile data. + +Unless otherwise selected by the user, device or software receiving the image data, the perceptual rendering intent (0xA2B0 in ICC.1:2001-04 or ISO 15076-1:2010) transform should be used for interpretation of the colour imagery. + +Unsigned integer RGB formats, as may be specified using the PIXEL\_FORMAT tag defined in A.7.18, are a common form of imagery representation. When present with unsigned integer pixel formats, embedded ICC Profile data provides a non-ambiguous definition of the colour interpretation of an image. The colour interpretation of JPEG XR image data should be defined either explicitly using embedded ICC profile data. When, for an unsigned pixel format, ICC profile data is not present, COLOR\_SPACE is not present or not equal to 1, PTM\_COLOR\_INFO( ) is not present, and colour interpretation information is not available by other means, unsigned integer RGB data should be assumed to use the sRGB colour encoding specified in IEC 61966-2-1. + +Fixed point values are essentially signed, scaled integer values. Rather than interpreting the numbers as the integer step from the minimum limit to the maximum limit for a particular colour encoding, a fixed point number is scaled. In this fixed point colour space, zero could represent either the minimum device value or it could represent absolute black (zero photons). A value of 1.0 could represent the maximum device value or when applied to all channels that make up a pixel, it could represent a perfect diffuse white. The specific scaling for each bit depth specifies exactly what point in the entire signed integer range is interpreted as a value of 1.0. The type of black encoded at zero (e.g. the device black or zero photons), and the type of white encoded at 1.0 (e.g. some encoding maximum or a perfect diffuse white) are determined from the colour profile associated with the encoding. + +Unlike unsigned integer values that are often interpreted based on a colour component transfer function (CCTF) that may be different for different colour encodings, it is preferred that the fixed point colour encodings used for the JPEG XR context should be based on a linear CCTF (equivalent to a gamma equal to 1.0). + +Floating point numerical formats, as may be specified using the PIXEL\_FORMAT tag defined in A.7.18, should also be based on a linear CCTF (gamma = 1.0) colour encoding. ICC profiles embedded in images using a floating point pixel format as specified by PIXEL\_FORMAT in A.7.18 should therefore have a linear CCTF in the relative colorimetric rendering intent (0xA2B1 in ISO 15076-1:2010) transform. + +Fixed point or floating point RGB data, as may be specified using the PIXEL\_FORMAT tag defined in A.7.18, should use the scRGB colour space defined in IEC 61966-2-2, but without the offset and scaling that are applied to produce scRGB unsigned integer values (i.e the floating point scRGB is only a matrix transform from the CIE 1931 XYZ colour space specified in ISO 11664-1). scRGB is a linear CCTF (gamma = 1.0) colour encoding that uses the same colour primaries and white point chromaticity as sRGB, but has a different CCTF and image state. The scRGB black point is the numerical value 0.0 and corresponds to zero photons in the scene. The scRGB perfect diffuse white point is specified by all three colour channels set to a value of 1.0. + +Since the colour rendering of scene colorimetry is often scene-specific, the perceptual intent transforms found in embedded scRGB-float ICC profiles may be image-specific. However, the use of a default perceptual rendering may be appropriate under some circumstances. + +Devices and software receiving scRGB image data may also provide users with the opportunity to custom colour render scene-referred colorimetry. If such edits are to be saved, it is recommended that where possible they should be incorporated as changes to the perceptual rendering intent (0xA2B0 in ISO 15076-1:2010) transform in the embedded ICC profile, with the scRGB image data left unchanged. + +For Gray pixel formats, as may be specified using the PIXEL\_FORMAT tag defined in A.7.18, in the absence of ICC profile data, the represented Gray value should be inferred as the value of all three colour components of the corresponding RGB format. + +In the absence of an ICC profile, when no other indication of the colour interpretation is available by other means, any CMYK pixel format (as defined in A.7.18) should be assumed to be encoded according to ANSI CGATS/SWOP1 TR 003-2007 CMYK. + +--- + +1 Committee for Graphics Arts Technologies Standards/Specifications for Web Offset Publications. + +NOTE 1 – A profile for ANSI CGATS/SWOP TR 003-2007 CMYK is available from the ICC Profile Registry. The profile name in the registry is SWOP2006\_Coated3v2.icc. + +There is no inherent description of the colour context for n-channel data, so when using an n-channel pixel format, it is recommended that an ICC profile should always be included (when applicable). However, if an ICC profile is not present and no other indication of the colour interpretation is available by other means, the following default colour context assumptions are recommended. + +- When $n = 3$ , the three channels should be assumed to be red, green, and blue (RGB) encoded using the sRGB colour space. +- When $n > 3$ , the first four channels should be assumed to be CMYK encoded according to CGATS/SWOP TR003 2007 CMYK. Any additional channels should be discarded. + +NOTE 2 – A profile for ANSI CGATS/SWOP TR 003-2007 CMYK is available from the ICC Profile Registry. The profile name in the registry is SWOP2006\_Coated3v2.icc. + +## Annex D + +### Encoder processing + +(This annex does not form an integral part of this Recommendation | International Standard.) + +#### D.1 Overview + +The encoder carries out the following steps: + +- pre-scaling; +- colour conversion; +- transform; +- outer pre-filter; +- outer forward core transform (FCT); +- inner pre-filter; +- inner FCT; +- coefficient prediction; +- quantization; +- coefficient scanning; +- entropy coding. + +These steps are explained in D.2 to D.9. + +#### D.2 Pre-scaling + +The pre-scaling steps are applied for 16-bit unsigned integer (BD16), 16-bit signed integer (BD16S), 16-bit float (BD16F), 32-bit signed integer (BD32S), 32-bit float (BD32F) and RGBE. They are usually used when the input data range is greater than 27/24 bits. The 27-bit limit is used when data is scaled, and the 24-bit limit applies when the data is unscaled. For the most common cases such as for 16-bit data, the pre-scaling steps are omitted although they may still be used. + +For OUTPUT\_BITDEPTH equal to BD16, BD16S or BD32S, input values are right-shifted by the value specified by SHIFT\_BITS. The function PreScaling1( ) is specified in Table D.1. + +**Table D.1 – Pseudocode for function PreScaling1( )** + +| PreScaling1(iInput) { | Reference | +|----------------------------------|------------------| +| iOutput = (iInput >> SHIFT_BITS) | | +| return iOutput | | +| } | | + +For OUTPUT\_BITDEPTH equal to BD16F, a sign bit extension is applied. The function PreScalingBD16F( ) is specified in Table D.2. + +**Table D.2 – Pseudocode for function PreScalingBD16F( )** + +| PreScalingBD16F(fV) { | Reference | +|------------------------------|------------------| +| if (fV < 0) | | +| iS = 1 | | +| else | | +| iS = 0 | | +| iX = (fV & 0x7fff) ^ iS – iS | | +| return iX | | +| } | | + +For OUTPUT\_BITDEPTH equal to BD32F, the encoder first selects a value of mantissa length LEN\_MANTISSA, and an exponent bias EXP\_BIAS. LEN\_MANTISSA is less than or equal to 23. The function PreScalingBD32F( ) is specified in Table D.3. + +**Table D.3 – Pseudocode for function PreScalingBD32F()** + +| PreScalingBD32F(fV) { | Reference | +|--------------------------------------------------------------------------------------|------------------| +| if (fV == 0) | | +| iX = 0 | | +| else { | | +| iS = (fV >> 31) & 0x00000001 | | +| iE = (fV >> 23) & 0x000000FF | | +| iM = (fV & 0x007FFFFFFF) 0x800000 | | +| if (iE == 0) { | | +| iM ^= 0x800000 | | +| iE++ | | +| } | | +| iE = iE - 127 + EXP_BIAS | | +| if (iE <= 1) { | | +| if (iE < 1) | | +| iM >>= (1 - iE) | | +| iE = 1 | | +| if ((iM & 0x800000) == 0) | | +| iE = 0 | | +| } | | +| iM = (((iM & 0x007FFFFFFF) + (1 << (23 - LEN_MANTISSA - 1))) >> (23 - LEN_MANTISSA)) | | +| iX = ((iE << LEN_MANTISSA) iM) ^ iS - iS | | +| } | | +| return iX | | +| } | | + +For OUTPUT\_CLR\_FMT equal to RGBE, the function PreScalingRGBE() is specified in Table D.4 and Table D.5. + +**Table D.4 – Pseudocode for function PreScalingRGBE()** + +| PreScalingRGBE(arrayOut[ ], arrayIn[ ]) { | Reference | +|-------------------------------------------------------------|------------------| +| arrayOut[0] = RGBEForwardConversion(arrayIn[0], arrayIn[3]) | | +| arrayOut[1] = RGBEForwardConversion(arrayIn[1], arrayIn[3]) | | +| arrayOut[2] = RGBEForwardConversion(arrayIn[2], arrayIn[3]) | | +| } | | + +**Table D.5 – Pseudocode for function RGBEForwardConversion()** + +| RGBEForwardConversion(iRGB, iE) { | Reference | +|--------------------------------------------|------------------| +| if (iE == 0) | | +| return 0 | | +| iAppend = 1 | | +| iE -= 1 | | +| while (((iRGB & 0x80) == 0) && (iE > 0)) { | | +| iRGB = (iRGB << 1) + iAppend | | +| iAppend = 0 | | +| iE -= 1 | | +| } | | +| if (iE == 0) | | +| iX = iRGB | | +| else { | | +| iE++ | | +| iX = (iRGB & 0x7f) + (iE << 7) | | +| } | | +| return iX | | +| } | | + +## D.3 Colour conversion + +### D.3.1 General + +The encoder uses a reversible colour format conversion to convert between the OUTPUT\_CLR\_FMT and INTERNAL\_CLR\_FMT. + +RGB to YUV444 colour format conversion is performed using FwdColorFmtConvert1( ) that is specified in D.3.2. In order to convert from RGB to YUV422 or YUV420, downsampling must be performed after colour format conversion using FwdColorFmtConvert1( ). RGB to YONLY conversions may be performed using FwdColorFmtConvert1( ) by discarding the U and V components on the encoder side. CMYK to YUVK colour format conversion is performed using FwdColorFmtConvert2( ) that is specified in D.3.3. CMYKDIRECT to YUVK colour format conversion is performed using FwdColorFmtConvert3( ) that is specified in D.3.4. + +Prior to colour conversion, a bias is subtracted from all values, to zero centre their range. The amount of the bias is determined by the source bit depth, and is exactly as specified in 9.10.5. When the scaling mode is used, the colour values are shifted left prior to encoder colour conversion. + +### D.3.2 FwdColorFmtConvert1( ) + +The function FwdColorFmtConvert1( ) implements the following operations to convert from RGB to YUV444 in Table D.6. When the decoded image is intended to be formatted using OUTPUT\_CLR\_FMT equal to RGB and OUTPUT\_BITDEPTH equal to BD5, BD565 or BD10, the process depends on the selected behaviour for the decoder with respect to the RED\_BLUE\_NOT\_SWAPPED\_FLAG syntax element. + +NOTE – The specification of semantics for RED\_BLUE\_NOT\_SWAPPED\_FLAG was not included in the original edition of this Specification. The specification of RED\_BLUE\_NOT\_SWAPPED\_FLAG was added later to address a problem with respect to the observed behaviour of existing implementations. In principle, when OUTPUT\_CLR\_FMT is equal to RGB and OUTPUT\_BITDEPTH is equal to BD5, BD565, or BD10, the value 1 for RED\_BLUE\_NOT\_SWAPPED\_FLAG should ordinarily provide better compression capability than the value 0. However, early product implementations of this Specification have operated in a manner corresponding to the value 0. Encoders that are designed primarily for interoperability with early product implementations of this Specification should therefore use the value 0 for RED\_BLUE\_NOT\_SWAPPED\_FLAG when OUTPUT\_CLR\_FMT is equal to RGB and OUTPUT\_BITDEPTH is equal to BD5, BD565 or BD10. It is anticipated that, as time passes, decoder implementations will also properly support operation with the value 1 for RED\_BLUE\_NOT\_SWAPPED\_FLAG when OUTPUT\_CLR\_FMT is equal to RGB and OUTPUT\_BITDEPTH is equal to BD5, BD565 or BD10. + +**Table D.6 – Pseudocode for function FwdColorFmtConvert1( )** + +| FwdColorFmtConvert1(arrayIn[ ], arrayOut[ ]) { | Reference | +|------------------------------------------------------------------------------------------------------------------------------------------------------|-----------| +| /* arrayIn[ ] = {R, G, B} */ | | +| /* arrayOut[ ] = {Y, U, V} */ | | +| if((OUTPUT_CLR_FMT == RGB) &&
(OUTPUT_BITDEPTH == BD5 OUTPUT_BITDEPTH == BD565
OUTPUT_BITDEPTH == BD10) && !RED_BLUE_NOT_SWAPPED_FLAG) { | | +| /* swappedRBflag = 1 */ | | +| arrayTemp[0] = arrayIn[2] | | +| arrayTemp[1] = arrayIn[1] | | +| arrayTemp[2] = arrayIn[0] | | +| } else { | | +| /* swappedRBflag = 0 */ | | +| arrayTemp[0] = arrayIn[0] | | +| arrayTemp[1] = arrayIn[1] | | +| arrayTemp[2] = arrayIn[2] | | +| } | | +| arrayOut[2] = arrayTemp[2] – arrayTemp[0]
/* V = B – R, except when swappedRBflag is equal to 1 */ | | +| tempT = arrayTemp[0] – arrayTemp[1] + Ceiling(arrayOut[2] ÷ 2)
/* t = R – G + Ceiling(V ÷ 2), except when swappedRBflag is equal to 1 */ | | +| arrayOut[0] = arrayTemp[1] + Floor(tempT ÷ 2)
/* Y = G + Floor(t ÷ 2) */ | | +| arrayOut[1] = –tempT /* U = –t */ | | +| } | | + +### D.3.3 FwdColorFmtConvert2( ) + +The function FwdColorConvert2( ) implements the following operations to convert from CMYK to YUVK in Table D.7. + +**Table D.7 – Pseudocode for function FwdColorFmtConvert2()** + +| FwdColorFmtConvert2(arrayIn[ ], arrayOut[ ]) { | Reference | +|--------------------------------------------------------------------------------------------------|------------------| +| /* arrayIn[ ] = {c, m, y, k} */ | | +| /* arrayOut[ ] = {Y, U, V, K} */ | | +| arrayOut[2] = arrayIn[0] – arrayIn[2] /* c – y */ | | +| arrayOut[1] = arrayIn[0] – arrayIn[1] + Floor(arrayOut[2] ÷ 2) /* c – m – Floor(V ÷ 2) */ | | +| arrayOut[0] = arrayIn[3] – arrayIn[1] + Floor(arrayOut[1] ÷ 2) /* k – m – Floor(U ÷ 2) */ | | +| arrayOut[3] = arrayIn[3] – Floor(arrayOut[0] ÷ 2) /* K = k – Floor(Y ÷ 2) */ | | +| } | | + +### D.3.4 FwdColorFmtConvert3() + +The function FwdColorConvert3() implements the following operations to convert from CMYKDIRECT to YUVK in Table D.8. + +**Table D.8 – Pseudocode for function FwdColorFmtConvert3()** + +| FwdColorFmtConvert3(arrayIn[ ], arrayOut[ ]) { | Reference | +|-------------------------------------------------------|------------------| +| /* arrayIn[ ] = {c, m, y, k} */ | | +| /* arrayOut[ ] = {Y, U, V, K} */ | | +| arrayOut[2] = arrayIn[1] /* V = m */ | | +| arrayOut[1] = arrayIn[0] /* U = c */ | | +| arrayOut[0] = arrayIn[3] /* Y = k */ | | +| arrayOut[3] = arrayIn[2] /* K = y */ | | +| } | | + +### D.3.5 Macroblock alignment and padding + +The width and height of images are not always integer multiples of 16. When an image width or height is not an integer multiple of 16, the image is extended by some means so that the extended image has dimensions that are multiples of 16. + +A suggested method of image extension is to perform horizontal replication of the bottom and right edge sample values to the extent necessary to form an input array having a conforming (multiple of 16) extended image width and height. + +## D.4 Transform + +The encoder uses a two level lapped transform, which is structured as follows: + +- A pre-filter operation is optionally applied to 4×4 areas evenly straddling blocks in two dimensions. For images with soft tiles, this filter is applied to all such blocks. For images with hard tiles, this filter is applied only to the interior of tiles. Furthermore, a pre-filter is applied to boundary areas which are 2×4 or 4×2 in size, and a pre-filter is applied to the four 2×2 corners on each colour component. For images with hard tiles, these filters are additionally applied at tile boundaries. +- An FCT is applied to all 4×4 blocks. This completes the first transform level. +- DC coefficients of the 4×4 blocks are grouped together. 16 Such coefficients are present for each macroblock colour component, and these are structured as 4×4 blocks in the DC-LP array. +- A second level pre-filter operation is optionally applied to 4×4 areas evenly straddling blocks in two dimensions in the DC-LP array. For images with soft tiles, this filter is applied to all such blocks. For images with hard tiles, this filter is applied only to the interior of tiles. Furthermore, a pre-filter is applied to boundary 2×4 and 4×2 areas, and a pre-filter is applied to the four 2×2 corner areas. For images with hard tiles, these filters are additionally applied at tile boundaries. +- The FCT is applied to each 4×4 block corresponding to DC coefficients in a macroblock colour component. + +The pre-filtering operation is applied across macroblock boundaries and optionally across tile boundaries. If HARD\_TILING\_FLAG is set equal to FALSE, the pre-filtering is applied across tile boundaries. Otherwise, the pre-filtering operation is not applied across tile boundaries and tile boundaries are treated as image edges instead. + +These operations are repeated for all colour components. For the special cases of INTERNAL\_CLR\_FMT equal to YUV422 or YUV420, appropriately modified transforms are applied (for instance a 2×2 transform is used as the block transform of the chroma component DC-LP arrays of YUV420). + +"OverlapPreFilter1" in Figure D.1 is used to denote the corner prediction process, and the process is equivalent to "OverlapPostFilter1" detailed in Table 154 and Table 155. + +An overview of this process is shown in Figure D.1. + +![Flowchart of the Encoder transform process, divided into First level and Second level.](6f7323b820d2c28a31e1161ca131cf03_img.jpg) + +The flowchart illustrates the Encoder transform process, divided into two levels: + +**First level:** + +- Starts with a decision diamond: "OVERLAP == 1 or 2?". + - If "No", it proceeds directly to the "FCT4x4" block. + - If "Yes", it proceeds to a decision diamond: "Corners?". + - If "Yes", it proceeds to the "OverlapPreFilter4" block. + - If "No", it proceeds to a decision diamond: "Boundaries?". + - If "Yes", it proceeds to the "OverlapPreFilter4" block. + - If "No", it proceeds to the "OverlapPreFilter4x4" block. + +**Second level:** + +- The output from the First level (either from "FCT4x4" directly or via the pre-filters) enters the Second level. +- The flow enters a decision diamond: "(420 or 422) U or V?". + - If "No", it proceeds to a decision diamond: "OVERLAP == 2?". + - If "No", it proceeds to the "FCT2x2 (and 2ptT if 422)" block. + - If "Yes", it proceeds to a decision diamond: "Corners?". + - If "Yes", it proceeds to the "OverlapPreFilter1" block. + - If "No", it proceeds to a decision diamond: "Boundaries?". + - If "Yes", it proceeds to the "OverlapPreFilter2" block. + - If "No", it proceeds to the "OverlapPreFilter2x2" block. + - If "Yes", it proceeds to a decision diamond: "Boundaries?". + - If "Yes", it proceeds to the "OverlapPreFilter4" block. + - If "No", it proceeds to a decision diamond: "Corners?". + - If "Yes", it proceeds to the "OverlapPreFilter4" block. + - If "No", it proceeds to the "OverlapPreFilter4x4" block. +- The outputs from the chroma-specific pre-filters feed into an "FCT4x4" block. +- The outputs from the non-chroma pre-filters and the "FCT4x4" block feed into the final "FCT2x2 (and 2ptT if 422)" block. + +Flowchart of the Encoder transform process, divided into First level and Second level. + +**Figure D.1 – Encoder transform** + +The application of overlap filters is governed by the OVERLAP\_MODE syntax element. Lossless coding is possible with all overlap modes, although OVERLAP\_MODE equal to 0 is usually best or sufficient for lossless coding. OVERLAP\_MODE equal to 1 produces the shortest codestream for a large class of images and quantization levels. OVERLAP\_MODE equal to 2 is recommended for high quantization levels, but with slightly higher complexity. OVERLAP\_MODE equal to 0 is recommended for lowest complexity encoding/decoding; however, this mode implements a hierarchical block transform and potentially introduces blocking at low bit rates. + +The forward core transform (FCT) process can be written as the cascade of three elementary $2 \times 2$ transform operations, which are: + +- 1) $2 \times 2$ Hadamard transform: T2x2h( ) +- 2) 1D rotate: TOdd( ) + +3) 2D rotate: TOddOdd() + +#### D.4.1 T2x2h() + +As specified in 9.9.7.2. + +#### D.4.2 TOdd() + +TOdd() is specified by the pseudocode in Table D.9. + +**Table D.9 – Pseudocode for function TOdd()** + +| TOdd(iCoeff[] ) { | +|------------------------------------------------| +| iCoeff[1] -= iCoeff[2] | +| iCoeff[0] += iCoeff[3] | +| iCoeff[2] += ((iCoeff[1] + 1) >> 1) | +| iCoeff[3] = ((iCoeff[0] + 1) >> 1) - iCoeff[3] | +| iCoeff[1] -= ((3* iCoeff[0] + 4) >> 3) | +| iCoeff[0] += ((3* iCoeff[1] + 4) >> 3) | +| iCoeff[3] -= ((3* iCoeff[2] + 4) >> 3) | +| iCoeff[2] += ((3* iCoeff[3] + 4) >> 3) | +| iCoeff[3] += (iCoeff[1] >> 1) | +| iCoeff[2] -= ((iCoeff[0] + 1) >> 1) | +| iCoeff[1] -= iCoeff[3] | +| iCoeff[0] += iCoeff[2] | +| } | + +#### D.4.3 TOddOdd() + +TOddOdd() is specified by the pseudocode in Table D.10. + +**Table D.10 – Pseudocode for function TOddOdd()** + +| TOddOdd(iCoeff[] ) { | +|-----------------------------------------| +| iCoeff[1] = -iCoeff[1] | +| iCoeff[2] = -iCoeff[2] | +| iCoeff[3] += iCoeff[0] | +| iCoeff[2] -= iCoeff[1] | +| iCoeff[0] -= (valT1 = iCoeff[3] >> 1) | +| iCoeff[1] += (valT2 = iCoeff[2] >> 1) | +| iCoeff[0] += ((iCoeff[1] * 3 + 4) >> 3) | +| iCoeff[1] -= ((iCoeff[0] * 3 + 3) >> 2) | +| iCoeff[0] += ((iCoeff[1] * 3 + 3) >> 3) | +| iCoeff[1] -= valT2 | +| iCoeff[0] += valT1 | +| iCoeff[2] += iCoeff[1] | +| iCoeff[3] -= iCoeff[0] | +| } | + +#### D.4.4 FwdPermute() + +The forward permutation function FwdPermute() operates on an ordered array of 16 sample values, producing a permuted list. The input to this function is the ordered array arrayInput[i], for i ranging from 0 to 15. The output of this function is the re-ordered array arrayInput[i]. + +To define the permutation, the array FwdPermArr[i] is specified, for i ranging from 0 to 15, in Table D.11. + +**Table D.11 – Forward Permutation** + +| i | FwdPermArr[i] | +|----------|----------------------| +| 0 | 0 | +| 1 | 8 | +| 2 | 4 | +| 3 | 6 | +| 4 | 2 | +| 5 | 10 | +| 6 | 14 | +| 7 | 12 | +| 8 | 1 | +| 9 | 11 | +| 10 | 15 | +| 11 | 13 | +| 12 | 9 | +| 13 | 3 | +| 14 | 7 | +| 15 | 5 | + +The function FwdPermute( ) is specified in Table D.12. + +**Table D.12 – Pseudocode for function FwdPermute( )** + +| FwdPermute(arrayInput[ ]) { | Reference | +|------------------------------------------|------------------| +| for (i = 0; i <= 15; i++) | | +| arrayTemp[FwdPermArr[i]] = arrayInput[i] | | +| for (i = 0; i <= 15; i++) | | +| arrayInput[i] = arrayTemp[i] | | +| } | | + +## D.4.5 FCT operations + +### D.4.5.1 FCT4x4( ) + +The input to the FCT4x4 function is an array of length 16, denoted iCoeff[ ]. The output of this function is a modified array of length 16 denoted iCoeff[ ]. + +The FCT4x4( ) is built using the three operators: T2x2h( ), TOdd( ) and TOddOdd( ), followed by the permutation function FwdPermute( ). The FCT begins with two transform stages. Each stage consists of four 2×2 transforms which may be done in any arbitrary sequence or concurrently within the stage. However, the first stage transforms must be complete before any of the second stage transforms are initiated. Also, for each function called in the FCT, the inverse of that function is called in the ICT pseudocode (9.9.7.1), with the exact same set of parameters. + +When these two transform stages are complete, the coefficients need to be re-ordered by the FwdPermute( ) function. + +The FCT4x4( ) function is specified by the pseudocode in Table D.13. + +**Table D.13 – Pseudocode for function FCT4x4( )** + +| FCT4x4(iCoeff[ ]) { | Reference | +|----------------------------------------------------------------|------------------| +| /* First stage */ | | +| arrayLocal[ ] = {iCoeff[0], iCoeff[3], iCoeff[12], iCoeff[15]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| iCoeff[0] = arrayLocal[0] | | +| iCoeff[3] = arrayLocal[1] | | +| iCoeff[12] = arrayLocal[2] | | +| iCoeff[15] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[5], iCoeff[6], iCoeff[9], iCoeff[10]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| iCoeff[5] = arrayLocal[0] | | +| iCoeff[6] = arrayLocal[1] | | +| iCoeff[9] = arrayLocal[2] | | + +| FCT4x4(iCoeff[ ]) { | Reference | +|------------------------------------------------------------------|------------------| +| iCoeff[10] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[1], iCoeff[2], iCoeff[13], iCoeff[14]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| iCoeff[1] = arrayLocal[0] | | +| iCoeff[2] = arrayLocal[1] | | +| iCoeff[13] = arrayLocal[2] | | +| iCoeff[14] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[4], iCoeff[7], iCoeff[8], iCoeff[11]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| iCoeff[4] = arrayLocal[0] | | +| iCoeff[7] = arrayLocal[1] | | +| iCoeff[8] = arrayLocal[2] | | +| iCoeff[11] = arrayLocal[3] | | +| /* Second stage */ | | +| arrayLocal[ ] = {iCoeff[0], iCoeff[1], iCoeff[4], iCoeff[5]} | | +| T2x2h(arrayLocal[ ], 1) | 9.9.7.2 | +| iCoeff[0] = arrayLocal[0] | | +| iCoeff[1] = arrayLocal[1] | | +| iCoeff[4] = arrayLocal[2] | | +| iCoeff[5] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[2], iCoeff[3], iCoeff[6], iCoeff[7]} | | +| TOdd(arrayLocal[ ]) | D.4.3 | +| iCoeff[2] = arrayLocal[0] | | +| iCoeff[3] = arrayLocal[1] | | +| iCoeff[6] = arrayLocal[2] | | +| iCoeff[7] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[8], iCoeff[12], iCoeff[9], iCoeff[13]} | | +| TOdd(arrayLocal[ ]) | D.4.3 | +| iCoeff[8] = arrayLocal[0] | | +| iCoeff[12] = arrayLocal[1] | | +| iCoeff[9] = arrayLocal[2] | | +| iCoeff[13] = arrayLocal[3] | | +| arrayLocal[ ] = {iCoeff[10], iCoeff[11], iCoeff[14], iCoeff[15]} | | +| TOddOdd(arrayLocal[ ]) | D.4.3 | +| iCoeff[10] = arrayLocal[0] | | +| iCoeff[11] = arrayLocal[1] | | +| iCoeff[14] = arrayLocal[2] | | +| iCoeff[15] = arrayLocal[3] | | +| /* Permute the coefficients */ | | +| FwdPermute(iCoeff[ ]) | D.4.4 | +| } | | + +### D.4.5.2 FCT2x2( ) + +The function FCT2x2( ) is identical to the T2x2h( ) function specified in Table 161. + +## D.5 Overlap pre-filtering + +### D.5.1 Overview + +Four operators determine the overlap pre-filters used in the transform. These are: + +- 1) Overlap Prefilter4x4 +- 2) OverlapPrefilter4 +- 3) OverlapPreFilter2x2 +- 4) OverlapPreFilter2 + +The pre-filter makes use of the operators T2x2hEnc( ), FwdRotate( ), FwdScale( ) and FwdTOddOdd( ) that are specified in Table D.14, Table D.15, Table D.16, and Table D.17, respectively. + +### D.5.1.1 T2x2hEnc() + +T2x2hEnc() is specified by the pseudocode in Table D.14. + +**Table D.14 – Pseudocode for function T2x2hEnc()** + +| | +|----------------------------------------------------| +| T2x2hEnc(iCoeff[] ) { | +| iCoeff[0] += iCoeff[3] | +| iCoeff[1] -= iCoeff[2] | +| valT1 = iCoeff[3] | +| valT2 = iCoeff[2] | +| iCoeff[2] = ((iCoeff[0] - iCoeff[1]) >> 1) - valT1 | +| iCoeff[3] = valT2 + (iCoeff[1] >> 1) | +| iCoeff[1] += iCoeff[2] | +| iCoeff[0] -= (iCoeff[3] * 3 + 4) >> 3 | +| } | + +### D.5.1.2 FwdRotate() + +FwdRotate() is specified by the pseudocode in Table D.15. + +**Table D.15 – Pseudocode for function FwdRotate()** + +| | +|-----------------------------------| +| FwdRotate(iCoeff[] ) { | +| iCoeff[1] -= (iCoeff[0] + 1) >> 1 | +| iCoeff[0] += (iCoeff[1] + 1) >> 1 | +| } | + +### D.5.1.3 FwdScale() + +FwdScale() is specified by the pseudocode in Table D.16. + +**Table D.16 – Pseudocode for function FwdScale()** + +| | +|------------------------------------------| +| FwdScale(iCoeff[] ) { | +| iCoeff[1] -= (iCoeff[0] * 3 + 0) >> 4 | +| iCoeff[1] -= (iCoeff[0] >> 7) | +| iCoeff[1] += (iCoeff[0] >> 10) | +| iCoeff[0] -= (iCoeff[1] * 3 + 0) >> 3 | +| iCoeff[1] = (iCoeff[0] >> 1) - iCoeff[1] | +| iCoeff[0] -= iCoeff[1] | +| } | + +### D.5.1.4 FwdTOddOdd() + +FwdTOddOdd() is specified by the pseudocode in Table D.17. + +**Table D.17 – Pseudocode for function FwdTOddOdd()** + +| | +|---------------------------------------| +| FwdTOddOdd(iCoeff[] ) { | +| iCoeff[3] += iCoeff[0] | +| iCoeff[2] -= iCoeff[1] | +| valT1 = iCoeff[3] >> 1 | +| valT2 = iCoeff[2] >> 1 | +| iCoeff[0] -= valT1 | +| iCoeff[1] += valT2 | +| iCoeff[0] += (iCoeff[1] * 3 + 4) >> 3 | +| iCoeff[1] -= (iCoeff[0] * 3 + 2) >> 2 | +| iCoeff[0] += (iCoeff[1] * 3 + 6) >> 3 | +| iCoeff[1] -= valT2 | +| iCoeff[0] += valT1 | +| iCoeff[2] += iCoeff[1] | +| iCoeff[3] -= iCoeff[0] | +| } | + +### D.5.1.5 OverlapPreFilter4x4( ) + +The 4×4 pre-filter is applied to all block junctions (areas straddling 4 blocks evenly) in all colour components when OVERLAP\_MODE is 1 or 2. Also, the 4×4 filter is applied to all block junctions in the DC-LP array for all planes when OVERLAP\_MODE is 2, and for only the luma plane when OVERLAP\_MODE is 2 and INTERNAL\_CLR\_FMT is equal to YUV420 or YUV422. + +The function OverlapPreFilter4x4( ) is specified in Table D.18. + +**Table D.18 – Pseudocode for function OverlapPreFilter4x4( )** + +| OverlapPreFilter4x4(iCoeff[ ]) { | Reference | +|----------------------------------------------------------------|------------------| +| arrayLocal[ ] = {iCoeff[0], iCoeff[3], iCoeff[12], iCoeff[15]} | | +| T2x2hEnc(arrayLocal[ ]) | D.5.1.1 | +| iCoeff[0] = localArray[0] | | +| iCoeff[3] = localArray[1] | | +| iCoeff[12] = localArray[2] | | +| iCoeff[15] = localArray[3] | | +| arrayLocal[ ] = {iCoeff[1], iCoeff[2], iCoeff[13], iCoeff[14]} | | +| T2x2hEnc(arrayLocal[ ]) | D.5.1.1 | +| iCoeff[1] = localArray[0] | | +| iCoeff[2] = localArray[1] | | +| iCoeff[13] = localArray[2] | | +| iCoeff[14] = localArray[3] | | +| arrayLocal[ ] = {iCoeff[4], iCoeff[7], iCoeff[8], iCoeff[11]} | | +| T2x2hEnc(arrayLocal[ ]) | D.5.1.1 | +| iCoeff[4] = localArray[0] | | +| iCoeff[7] = localArray[1] | | +| iCoeff[8] = localArray[2] | | +| iCoeff[11] = localArray[3] | | +| arrayLocal[ ] = {iCoeff[5], iCoeff[6], iCoeff[9], iCoeff[10]} | | +| T2x2hEnc(arrayLocal[ ]) | D.5.1.1 | +| iCoeff[5] = localArray[0] | | +| iCoeff[6] = localArray[1] | | +| iCoeff[9] = localArray[2] | | +| iCoeff[10] = localArray[3] | | +| arrayLocal[ ] = {iCoeff[0], iCoeff[15]} | | +| FwdScale(arrayLocal[ ]) | D.5.1.3 | +| iCoeff[0] = localArray[0] | | +| iCoeff[15] = localArray[1] | | +| arrayLocal[ ] = {iCoeff[1], iCoeff[14]} | | +| FwdScale(arrayLocal[ ]) | D.5.1.3 | +| iCoeff[1] = localArray[0] | | +| iCoeff[14] = localArray[1] | | +| arrayLocal[ ] = {iCoeff[4], iCoeff[11]} | | +| FwdScale(arrayLocal[ ]) | D.5.1.3 | +| iCoeff[4] = localArray[0] | | +| iCoeff[11] = localArray[1] | | +| arrayLocal[ ] = {iCoeff[5], iCoeff[10]} | | +| FwdScale(arrayLocal[ ]) | D.5.1.3 | +| iCoeff[5] = localArray[0] | | +| iCoeff[10] = localArray[1] | | +| arrayLocal[ ] = {iCoeff[13], iCoeff[12]} | | +| FwdRotate(arrayLocal[ ]) | D.5.1.2 | +| iCoeff[13] = localArray[0] | | +| iCoeff[12] = localArray[1] | | +| arrayLocal[ ] = {iCoeff[9], iCoeff[8]} | | +| FwdRotate(arrayLocal[ ]) | D.5.1.2 | +| iCoeff[9] = localArray[0] | | +| iCoeff[8] = localArray[1] | | +| arrayLocal[ ] = {iCoeff[7], iCoeff[3]} | | +| FwdRotate(arrayLocal[ ]) | D.5.1.2 | +| iCoeff[7] = localArray[0] | | +| iCoeff[3] = localArray[1] | | + +| | | +|------------------------------------------------------------------|---------| +| arrayLocal[ ] = {iCoeff[6], iCoeff[2]} | | +| FwdRotate(arrayLocal[ ]) | D.5.1.2 | +| iCoeff[6] = localArray[0] | | +| iCoeff[2] = localArray[1] | | +| arrayLocal[ ] = {iCoeff[10], iCoeff[11], iCoeff[14], iCoeff[15]} | | +| FwdTOddOdd(arrayLocal[ ]) | D.5.1.4 | +| iCoeff[10] = localArray[0] | | +| iCoeff[11] = localArray[1] | | +| iCoeff[14] = localArray[2] | | +| iCoeff[15] = localArray[3] | | +| arrayLocal[ ] = {iCoeff[0], iCoeff[12], iCoeff[3], iCoeff[15]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| iCoeff[0] = localArray[0] | | +| iCoeff[12] = localArray[1] | | +| iCoeff[3] = localArray[2] | | +| iCoeff[15] = localArray[3] | | +| arrayLocal[ ] = {iCoeff[1], iCoeff[2], iCoeff[13], iCoeff[14]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| iCoeff[1] = localArray[0] | | +| iCoeff[2] = localArray[1] | | +| iCoeff[13] = localArray[2] | | +| iCoeff[14] = localArray[3] | | +| arrayLocal[ ] = {iCoeff[4], iCoeff[7], iCoeff[8], iCoeff[11]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| iCoeff[4] = localArray[0] | | +| iCoeff[7] = localArray[1] | | +| iCoeff[8] = localArray[2] | | +| iCoeff[11] = localArray[3] | | +| arrayLocal[ ] = {iCoeff[5], iCoeff[6], iCoeff[9], iCoeff[10]} | | +| T2x2h(arrayLocal[ ], 0) | 9.9.7.2 | +| iCoeff[5] = localArray[0] | | +| iCoeff[6] = localArray[1] | | +| iCoeff[9] = localArray[2] | | +| iCoeff[10] = localArray[3] | | +| } | | + +## D.5.2 OverlapPreFilter4() + +Linear 4-point filters are applied to edge straddling 2×4 and 4×2 areas on the boundary of the image. If the input data is an array of length 4, denoted iCoeff[ ], the 4-point pre-filter, OverlapPreFilter4(), is specified in Table D.19. + +**Table D.19 – Pseudocode for function OverlapPreFilter4()** + +| OverlapPreFilter4(iCoeff[ ]) | Reference | +|-----------------------------------------|-----------| +| iCoeff[0] += iCoeff[3] | | +| iCoeff[1] += iCoeff[2] | | +| iCoeff[3] -= ((iCoeff[0] + 1) >> 1) | | +| iCoeff[2] -= ((iCoeff[1] + 1) >> 1) | | +| FwdRotate(iCoeff[2], iCoeff[3]) | D.5.1.2 | +| iCoeff[3] = -iCoeff[3] | | +| iCoeff[2] = -iCoeff[2] | | +| iCoeff[0] -= iCoeff[3] | | +| iCoeff[1] -= iCoeff[2] | | +| iCoeff[3] += ( iCoeff[0] >> 1) | | +| iCoeff[2] += ( iCoeff[1] >> 1) | | +| iCoeff[0] -= ((iCoeff[3] * 3 + 4) >> 3) | | +| iCoeff[1] -= ((iCoeff[2] * 3 + 4) >> 3) | | +| FwdScale(iCoeff[0], iCoeff[3]) | D.5.1.3 | +| FwdScale(iCoeff[1], iCoeff[2]) | D.5.1.3 | +| iCoeff[3] += ((iCoeff[0] + 1) >> 1) | | +| iCoeff[2] += ((iCoeff[1] + 1) >> 1) | | +| iCoeff[0] -= iCoeff[3] | | +| iCoeff[1] -= iCoeff[2] | | +| } | | + +### D.5.3 OverlapPreFilter2x2 + +The 2×2 pre-filter is applied to areas straddling blocks in the DC-LP array for the chroma components when INTERNAL\_CLR\_FMT is equal to YUV420 or YUV422 data. The OverlapPreFilter2x2( ) function is specified in Table D.20. + +**Table D.20 – Pseudocode for function OverlapPreFilter2x2( )** + +| OverlapPreFilter2x2(iCoeff[ ]) { | +|-------------------------------------| +| iCoeff[0] += iCoeff[3] | +| iCoeff[1] += iCoeff[2] | +| iCoeff[3] -= ((iCoeff[0] + 1) >> 1) | +| iCoeff[2] -= ((iCoeff[1] + 1) >> 1) | +| iCoeff[1] -= ((iCoeff[0] + 2) >> 2) | +| iCoeff[0] -= (iCoeff[1] >> 5) | +| iCoeff[0] -= (iCoeff[1] >> 9) | +| iCoeff[0] -= (iCoeff[1] >> 13) | +| iCoeff[0] -= ((iCoeff[1] + 1) >> 1) | +| iCoeff[1] -= ((iCoeff[0] + 2) >> 2) | +| iCoeff[3] += ((iCoeff[0] + 1) >> 1) | +| iCoeff[2] += ((iCoeff[1] + 1) >> 1) | +| iCoeff[0] -= iCoeff[3] | +| iCoeff[1] -= iCoeff[2] | +| } | + +### D.5.4 OverlapPreFilter2 + +As for the 2-point filters, the 2-point pre-filter is applied to boundary 2×1 and 1×2 samples that straddle blocks. The 2-point pre-filter function OverlapPreFilter2( ) is specified in Table D.21. + +**Table D.21 – Pseudocode for function OverlapPreFilter2( )** + +| OverlapPreFilter2(iCoeff[ ]) { | +|-------------------------------------| +| iCoeff[1] -= ((iCoeff[0] + 2) >> 2) | +| iCoeff[0] -= (iCoeff[1] >> 13) | +| iCoeff[0] -= (iCoeff[1] >> 9) | +| iCoeff[0] -= (iCoeff[1] >> 5) | +| iCoeff[0] -= ((iCoeff[1] + 1) >> 1) | +| iCoeff[1] -= ((iCoeff[0] + 2) >> 2) | +| } | + +## D.6 Coefficient prediction + +The coefficient prediction process is the same as the corresponding process in the decoder. See 9.6. + +## D.7 Coefficient scanning + +The coefficient scanning process is the same as the corresponding process in the decoder. + +## D.8 Quantization + +Quantization is a process whereby the transform coefficients are divided by the quantization scaling factor and rounded to an integer value, called the *quantized value*. + +For lossless coding, the quantization scaling factor is selected to be equal to 1. For lossy coding, the quantization scaling factor is selected to be greater than 1. + +The quantization scaling factor used for quantization is determined as a function of the quantization factor in the same manner as for the decoding process. Larger values of the quantization parameter correspond to larger quantization scaling factors and (typically) correspond to lower fidelity representation of the image content. + +On the encoder side, the specific rounding method used in the process of quantization is implementation specific, and is not covered in this Specification. + +The quantization parameter is allowed to differ across HP, LP and DC bands. The DC QP index within a tile is fixed. The DC QP index across tiles may vary. The HP and LP QP indices within a tile may take on either the same value or one of a multiple value set. The QP index used may change at every macroblock, and is specified in the codestream. + +## D.9 Adaptive coefficient normalization + +Adaptive coefficient normalization partitions the transform coefficients into a VLC-coded part and an FLC part (called FLEXBITS). The VLC-coded part is obtained from a coarse quantization of the coefficient referred to as the normalized coefficient, while the FLEXBITS represents the LSBs and provides a refinement layer over the VLC-coded part. Sign information may also be present as part of FLEXBITS when the normalized coefficient is equal to 0. The partition between the VLC coded and the FLC coded parts is performed as follows. + +- 1) The functions `MB_HP()` (8.7.18.2) and `MB_HP_FLEX()` (8.7.18.3) specify how `iLapMean[0]` and `iLapMean[1]` are used to compute the total number of non-zero coefficients that have been coded for the luma and chroma components, respectively. +- 2) The `UpdateModelMB()` function (8.12.2) specifies how this information is used to compute `Model.MBits[0]` and `Model.MBits[1]` which are the number of LSBs that form the FLEXBITS portion of the luma and chroma components, respectively. The more significant bits are VLC coded. + +In effect, the number of non-zero coded coefficients is used as a measure of the statistical variance of the block. Thus, a larger number of non-zero coded coefficients in a block produces higher values of `iLapMean[ ]`, and thus result in FLEXBITS forming a larger fraction of the partition. As a result of this partition, entropy coding is applied only to the normalized coefficients with reduced dynamic range, and thus reduces the computational and memory complexity of entropy coding at both encoder and decoder. An overview of the adaptive coefficient normalization process at the encoder is shown in Figure D.2. + +![Diagram illustrating the adaptive normalization process and partitioning of coefficients into VLC coded and FLC coded parts.](aa23dbbc50355aed4783a5698f0ac691_img.jpg) + +The diagram illustrates the adaptive normalization process. It shows a sequence of horizontal bars representing 'Coefficients'. An arrow labeled 'Partitioning process' points from these coefficients to two columns: 'Normalized coefficients (VLC coded)' and 'Refinement (FLC coded)'. The 'Normalized coefficients' column contains a few thick black bars, while the 'Refinement' column contains many thin white bars. An arrow labeled 'Run-level / VLC coding' points from the 'Normalized coefficients' column to a thick black bar in the 'Codestream' section. An arrow labeled 'FLC coding' points from the 'Refinement' column to a thin black bar in the 'Codestream' section. The 'Codestream' section is divided into two parts: a 'VLC coded portion' (indicated by a bracket) and a 'Fixed length coded portion (Flexbits)' (indicated by a bracket). The 'VLC coded portion' contains the thick black bar, and the 'Fixed length coded portion' contains the thin black bar. The diagram is labeled 'T.832(12)\_FD.2' at the bottom right. + +Diagram illustrating the adaptive normalization process and partitioning of coefficients into VLC coded and FLC coded parts. + +**Figure D.2 – Representation of the adaptive normalization process and partitioning of coefficients into VLC coded and FLC coded parts** + +## Annex E + +### Media type specification for the Annex A tag-based file format + +(This annex forms an integral part of this Recommendation | International Standard.) + +#### E.1 General + +This annex is a media type specification for images encoded according to the tag-based format specified in Annex A of this Recommendation | International Standard for use in various Internet protocols, according to the scheme defined in IETF RFC 6838. Recent Internet protocols have been carefully designed to be easily extensible in certain areas, and many such protocols are capable of carrying arbitrary labelled content. The mechanism used to label such content is a media type, consisting of a top-level type, a subtype, and in some instances, optional parameters. This annex specifies such a content-labelling scheme for JPEG XR coded images, to correspond with a registration in the IANA2 central registry. + +#### E.2 Registration + +This media type may be used for images encoded according to the tag-based format specified in Annex A. + +Media type name: image + +Subtype name: jxr + +Required parameters: none + +Optional parameters: none + +Encoding considerations: files are binary and should be transmitted in a suitable encoding without CR/LF conversion, 7-bit stripping etc.; base64 is a suitable encoding. + +Security considerations: The conveyed coded image files use a structure that can store image data, metadata corresponding to this image data, and other user-defined data. It should be noted that selected metadata fields may encompass information partly intended to protect the image against unauthorized use or distribution. In this case, the intention may be that alteration or removal of the data in the fields would be treated as an offence. Metadata fields may also contain information about the source of the image content. The data files have an extensible structure, so that it is theoretically possible that metadata fields could be defined in the future that could be used to induce particular actions on the part of the recipient, thus presenting additional security risks, but this type of capability is currently not supported in the current referenced specifications. + +Interoperability considerations: JPEG XR coded image files can conform to one of several profiles and levels of capabilities (as specified in Annex B of this Recommendation | International Standard) – not all of which may be supported by a receiving decoder. As a result, implementations may attempt to decode and display an encoded JPEG XR image only to determine that the image cannot be rendered either partially or in full. + +Published specification: + +(this Recommendation | International Standard) Rec. ITU-T T.832 (in force) | ISO/IEC 29199-2 (in force), +*Information technology – JPEG XR image coding system – Image coding specification* + +Applications that use this media type: Imaging, fax, messaging and multi-media. + +Fragment identifier considerations: N/A + +Additional information: + +Deprecated alias names for this type: N/A + +Magic number(s): + +As specified in Annex A of this Recommendation | International Standard, the data begins with a FILE\_HEADER() data structure, which begins with a FIXED\_FILE\_HEADER\_II\_2BYTES field equal to 0x4949, followed by a FIXED\_FILE\_HEADER\_0XBC\_BYTE field equal to 0xBC, followed by a FILE\_VERSION\_ID which is equal to 1 for the current version of this Recommendation | International Standard (with other values reserved for future use, as modified in additional parts or amendments, by ITU-T | ISO/IEC). + +--- + +2Internet Assigned Numbers Authority. + +Within the payload data, JPEG XR IMAGE\_HEADER( ) data structures begin with a GDI\_SIGNATURE, which is a 64-bit syntax element that has the value 0x574D50484F544F00 that corresponds to "WMPHOTO" using the UTF-8 character set encoding specified in Annex D of ISO/IEC 10646, followed by a byte equal to 0. + +File extension(s): jxr + +Person and email address to contact for further information: + +ISO/IEC JTC 1/SC 29/WG 1 Convenor (sc29-sec@itscj.ipsj.or.jp) + +Intended usage: Common + +Restrictions on usage: N/A + +Author: ITU-T and ISO/IEC JTC 1 + +Change controller: ITU-T and ISO/IEC JTC 1 + +Provisional registration? (standards tree only): Same (image/jxr) + +## Annex F + +### Storage in the ISO/IEC 23008-12 image file format and associated media type registrations + +(This annex forms an integral part of this Recommendation | International Standard.) + +#### F.1 General + +This annex specifies a file format to encapsulate images, image collections, and image sequences coded using the JPEG XR format in the image file format specified in ISO/IEC 23008-12. The file format specified in this annex is an alternative to the tag-based file format specified in Annex A. Brands for a single image and an image collection as well as image sequences are specified in F.5. + +For the purposes of this annex, the terms, definitions, and abbreviated terms specified in ISO/IEC 23008-12 additionally apply. For the avoidance of doubt, in case of ambiguities, the definitions of ISO/IEC 23008-12 take precedence over the definitions in this annex. + +NOTE – A sample in the context of ISO/IEC 23008-12 is "all the data associated with a single time". In this Annex, this is meant as data associated with one coded image, not "one element in the two-dimensional image array which comprises a component". + +#### F.2 Normative references + +The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this annex to this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations. + +##### F.2.1 Identical Recommendations | International Standards + +None. + +##### F.2.2 Paired Recommendations | International Standards equivalent in technical content + +- Rec. ITU-T T.833 (2010) | ISO/IEC 29199-3:2010, *Information technology — JPEG XR image coding system — Motion JPEG XR* + +##### F.2.3 Additional references + +- ISO/IEC 23008-12:2017, *Information technology — High efficiency coding and media delivery in heterogeneous environments — Part 12: Image File Format* + +#### F.3 JPEG XR images and image collections + +##### F.3.1 General + +Subclause F.3 and its subclauses specify requirements for ISO/IEC 23008-12 files containing JPEG XR-coded image items. When a brand specified in F.5.1 is among the compatible brands of a file, the requirements specified in F.3 and its subclauses shall be obeyed. + +The specifications of clause 6 of ISO/IEC 23008-12:2017 and its subclauses apply. + +##### F.3.2 Image data + +An item of type '*jxr1*' is a CODED\_IMAGE() as defined in 8.2, *without* the IMAGE\_HEADER(). Each image presented to a JPEG XR decoder is logically formed by appending the content of each sample to the content of the JPEG XR header item property. + +NOTE 1 – Offset values in the coded image apply to this complete set of data that is supplied to the decoder, i.e. the result of the append of the sample data to the content of the JPEG XR header item property. An item of type '*jxr1*' is a sample. + +NOTE 2 – The item data is structurally identical to the syntax defined in Rec. ITU-T T.833 | ISO/IEC 29199-3 for a JPEG XR sample. + +### F.3.3 JPEG XR header item property + +#### F.3.3.1 Definition + +Box Type: 'jxrh' +Property Type: Descriptive item property +Container: ItemPropertyContainerBox +Mandatory (per an item): Yes, for an image item of type 'jxr1' +Quantity (per an item): One for an image item of type 'jxr1' + +Each JPEG XR image item shall have an associated property that is a JPEGXRHeaderProperty. + +NOTE – This is identical to the JPEGXRHeaderBox as defined in Rec. ITU-T T.833 | ISO/IEC 29199-3. + +essential shall be equal to 1 for a 'jxrh' item property associated with an image item of type 'jxr1'. + +#### F.3.3.2 Syntax + +``` +class JPEGXRHeaderProperty( ) + extends ItemFullProperty ('jxrh', 0, version=0){ + IMAGE_HEADER( ); + IsCurrPlaneAlphaFlag := FALSE; + IMAGE_PLANE_HEADER( ); + if (ALPHA_IMAGE_PLANE_FLAG) { + IsCurrPlaneAlphaFlag := TRUE; + IMAGE_PLANE_HEADER( ); + } +} +``` + +#### F.3.3.3 Semantics + +IMAGE\_HEADER() as defined in 8.3; + +IMAGE\_PLANE\_HEADER() as defined in 8.4; + +IsCurrPlaneAlphaFlag is not a field in this structure, but a local variable used in the decoding of the IMAGE\_PLANE\_HEADER(); + +ALPHA\_IMAGE\_PLANE\_FLAG is not a field in this structure, but a field in the IMAGE\_HEADER() which is tested here; + +PIXEL\_FORMAT as defined in A.7.18; + +IMAGE\_BAND\_PRESENCE as defined in A.7.31; + +ALPHA\_BAND\_PRESENCE as defined in A.7.32. + +### F.3.4 JPEG XR info item property + +#### F.3.4.1 Definition + +Box Type: 'jxri' +Property Type: Descriptive item property +Container: ItemPropertyContainerBox +Mandatory (per an item): Yes, for an image item of type 'jxr1' +Quantity (per an item): One for an image item of type 'jxr1' + +Each JPEG XR image item shall have an associated property that is a JPEGXRInfoProperty. + +NOTE – This is identical to the JPEGXRInfoBox as defined in Rec. ITU-T T.833 | ISO/IEC 29199-3. + +essential shall be equal to 1 for a 'jxri' item property associated with an image item of type 'jxr1'. + +### F.3.4.2 Syntax + +``` +class JPEGXRInfoProperty( ) + extends ItemFullProperty ('jxri', 0, version=0){ + UInt8[16] PIXEL_FORMAT; + UInt8 IMAGE_BAND_PRESENCE; + UInt8 ALPHA_BAND_PRESENCE; +} +``` + +### F.3.4.3 Semantics + +IMAGE\_BAND\_PRESENCE as defined in A.7.31; + +ALPHA\_BAND\_PRESENCE as defined in A.7.32. + +## F.3.5 JPEG XR profile item property + +### F.3.5.1 Definition + +Box Type: 'jxrp' + +Property Type: Descriptive item property + +Container: ItemPropertyContainerBox + +Mandatory (per an item): Yes, for an image item of type 'jxr1' + +Quantity (per an item): One for an image item of type 'jxr1' + +Each JPEG XR image item may have an associated property that is a JPEGXRProfileProperty. When this property is not present, the inference rules specified in B.1 for when the PROFILE\_LEVEL\_INFO() syntax structure is not present shall apply. + +NOTE – This is identical to the JPEGXRProfileBox as defined in Rec. ITU-T T.833 | ISO/IEC 29199-3. + +### F.3.5.2 Syntax + +``` +class JPEGXRProfileProperty( ) extends ItemProperty ('jxrp'){ + PROFILE_LEVEL_INFO( ); +} +``` + +### F.3.5.3 Semantics + +PROFILE\_LEVEL\_INFO() as defined in 8.6. + +## F.4 JPEG XR image sequences + +### F.4.1 General + +Subclause F.3.4 and its subclauses specify requirements for all files containing one or more JPEG XR-coded image sequence tracks. When a brand specified in F.5.2 is among the compatible brands of a file, the requirements specified in F.3.4 and its subclauses shall be obeyed. + +The specifications of clause 7 of ISO/IEC 23008-12:2017 and its subclauses apply. + +### F.4.2 Derivation from ISO/IEC 14496-12 and Rec. ITU-T T.833 | ISO/IEC 29199-3 + +A sample entry of type 'mjxr' shall be used for an image sequence track coded with JPEG XR, as defined in Rec. ITU-T T.833 | ISO/IEC 29199-3, using the MJXRSampleEntry and sample format as specified in Rec. ITU-T T.833 | ISO/IEC 29199-3. + +For a track containing a JPEG XR image sequence, all samples are sync samples. + +## F.5 JPEG XR-specific brands + +### F.5.1 JPEG XR image and image collection brands + +#### F.5.1.1 General + +The brand 'jxrA' is specified in the following subclauses. + +A coded image item is specified to conform to the 'jxrA' brand when all of the following constraints are true: + +- The item has type 'jxr1' and conforms to the specifications in F.3. +- The item is not associated with any other types of essential item properties than 'jxrh', 'jxri', 'jxrp', 'irot', 'clap' and 'imir'. +- The content of the item conforms to the coded image syntax of the profile and level indicated by `JPEGXRProfileProperty`. + +For the specifications below, a crop-rotate-mirror derived image item is defined as a derived image item of type 'iden' that is not associated with any other types of essential item properties than 'irot', 'clap', and 'imir'. + +### F.5.1.2 Requirements on files + +Files shall include 'mif1' among the compatible brands and hence shall conform to the specifications in A.2.1.1 of ISO/IEC 23008-12:2017. Additionally, such files shall comply with the specifications in F.3. + +The files conforming to the 'jxrA' brand shall additionally be constrained as follows: + +Files including 'jxrA' as a compatible brand shall contain an item that is present in the file, is either the primary item or any item from the alternate group containing the primary item, and fulfils one of the following constraints: + +- The item is a coded image item conforming to the 'jxrA' brand as specified in F.5.1.1. +- The item is a crop-rotate-mirror derived image item, and each source image item of the item is either a crop-rotate-mirror derived image item or a coded image item conforming to the 'jxrA' brand as specified in F.5.1.1. + +### F.5.1.3 Requirements on readers + +The requirements on readers specified in A.2.1.2 of ISO/IEC 23008-12:2017 shall be supported. + +Readers conforming to the 'jxrA' brand shall support displaying an item for which the `JPEGXRProfileProperty` indicates that `PROFILE_IDC` is equal to 44 (indicating the Sub-Baseline profile) and `LEVEL_IDC` is equal to 4 (the lowest level defined in B.3) that is either the primary item or any item from the alternate group containing the primary item and fulfils one of the following constraints: + +The item is a coded image item conforming to the 'jxrA' brand as specified in F.5.1.1. + +The item is a crop-rotate-mirror derived image item, and each source image item of the item is either a crop-rotate-mirror derived image item or a coded image item conforming to the 'jxrA' brand as specified in F.5.1.1. + +Readers conforming to the 'jxrA' brand are recommended but not required to decode coded images for all profiles and levels specified by Annex B. + +File readers should support displaying an image with opacity information specified by an associated auxiliary image. + +## F.5.2 JPEG XR image sequence brands + +### F.5.2.1 General + +The brand 'jxrS' is specified in the following subclauses. + +### F.5.2.2 Requirements on files + +Files shall include 'msf1' among the compatible brands and hence conform to the specifications in A.2.1.1 of ISO/IEC 23008-12:2017. Additionally, such files shall comply with the specifications in F.3.4. `Track_enabled` shall be equal to 1 and `Track_in_movie` shall be equal to 1 for at least one image sequence track conforming to with the specifications in F.3.4. + +When the 'jxrS' brand is among the compatible brands, there shall be an image sequence track with 'mjxr' or 'mjxs' sample entry type, `Track_enabled` equal to 1, `Track_in_movie` equal to 1, and each sample entry having a `data_reference_index` value such that it is mapped to a `DataEntryBox` with (`entry_flags & 1`) equal to 1, for which the coded image syntax conforms to the profile and level indicated by `JPEGXRProfileProperty`. + +NOTE – In other words, when the 'jxrS' brand is among the compatible brands, at least one viewable image sequence track is a JPEG XR image sequence track and contains a bitstream conforming to the coded image syntax of the profile and level indicated by `JPEGXRProfileProperty`. + +### F.5.2.3 Requirements on readers + +The requirements on readers specified in A.3.1.2 of ISO/IEC 23008-12:2017 shall be supported. + +Readers for the 'jxrs' brand shall be able to display an image sequence track with 'mjxs' sample entry type, `Track_enabled` equal to 1 and `Track_in_movie` equal to 1, for which the `JPEGXRProfileProperty` indicates that `PROFILE_IDC` is equal to 44 (indicating the Sub-Baseline profile) and `LEVEL_IDC` is equal to 4 (the lowest level defined in B.3). + +Readers shall support all values allowed by 7.2.1 of ISO/IEC 23008-12:2017 for the `matrix` syntax element of the `TrackHeaderBox` and shall obey the `CleanApertureBox` of the visual sample entry when displaying an image sequence track with 'mjxs' sample entry and having a `JPEGXRProfileProperty` with `LEVEL_IDC` equal to 4 (the lowest level defined in B.3). + +NOTE – In other words, readers are required to support rotation by 0, 90, 180, and 270 degrees and mirroring, as controlled by the `matrix` syntax element, as well as cropping, as controlled by the `CleanApertureBox`. + +Readers are recommended but not required to be able to display image sequence tracks with 'mjxs' sample entry type, `Track_enabled` equal to 1 and `Track_in_movie` equal to 1, for all levels specified by Annex B. + +Readers are recommended but not required to be able to display image sequence tracks with 'mjxr' sample entry type, `Track_enabled` equal to 1 and `Track_in_movie` equal to 1, for all profiles and all levels specified by Annex B. + +Displaying of an image sequence track with opacity information specified by an associated auxiliary track should be supported. + +## **F.6 Media type registration for JPEG XR coded images and image collections in the ISO/IEC 23008-12 image file format** + +### **F.6.1 General** + +Subclause F.6 and its subclauses are a media type specification for JPEG XR coded images and image collections in the image file format specified in ISO/IEC 23008-12 for use in various Internet protocols, according to the scheme defined in IETF RFC 6838 (BCP 13). Recent Internet protocols have been carefully designed to be easily extensible in certain areas, and many such protocols are capable of carrying arbitrary labelled content. The mechanism used to label such content is a media type, consisting of a top-level type, a subtype, and in some instances, optional parameters. Subclause F.6 and its subclauses specify such a content labelling scheme for JPEG XR coded images and image collections in the image file format specified in ISO/IEC 23008-12, to correspond with a registration in the IANA central registry. + +The file extension and media type of a file in this family usually reflect the major brand in the `FileTypeBox`. When the major brand indicates a brand related to F.5.1 (single image and image collection), the media type defined here should be used. When such a brand is a compatible brand, this media type may also be used. + +### **F.6.2 Registration** + +This media type may be used when the requirements of F.5.1 apply and the primary image satisfies the requirements of F.5.1.1. + +Media type name: image + +Subtype name: jxrA + +Required parameters: N/A + +Optional parameters: + +Same as for the media type image/heif, as specified in ISO/IEC 23008-12. + +For a JPEG XR coded image, the item type is 'jxr1'. + +Encoding considerations: binary + +Security considerations: See media type image/heif. In addition, image items of type 'jxr1' contain structures of variable length and have an extensible syntax. Both aspects present potential security risks for implementations. In particular, variable length structures present buffer overflow risks and extensible syntax could result in the triggering of adverse actions. + +Interoperability considerations: JPEG XR coded images can conform to one of several profiles and levels of capabilities (as specified in Annex B of Rec. ITU-T T.832 | ISO/IEC 29199-2) – not all of which may be supported by a receiving decoder. As a result, implementations may attempt to decode and display an encoded JPEG XR image only to determine that the image cannot be rendered either partially or in full. + +Published specification: + +(this Recommendation | International Standard) Rec. ITU-T T.832 (in force) | ISO/IEC 29199-2 (in force), +*Information technology – JPEG XR image coding system – Image coding specification* + +Applications: Multimedia and scientific + +Fragment identifier considerations: Same as for the media type image/heif. + +Restrictions on usage: N/A + +Additional information: + +Magic number(s): N/A + +File extension(s): jxra + +Macintosh File Type Code(s): N/A + +Object identifiers: N/A + +Persons and email address to contact for further information: + +ISO/IEC JTC 1/SC 29/WG 1 Convenor (sc29-sec@itscj.ipsj.or.jp) + +Intended usage: Common + +Author/Change controller: ITU-T and ISO/IEC JTC 1 + +## **F.7 Media type registration for JPEG XR coded image sequences in the ISO/IEC 23008-12 file format** + +### **F.7.1 General** + +Subclause F.7 and its subclauses are a media type specification for JPEG XR coded image sequences in the image file format specified in ISO/IEC 23008-12 for use in various Internet protocols, according to the scheme defined in IETF RFC 6838. Recent Internet protocols have been carefully designed to be easily extensible in certain areas, and many such protocols are capable of carrying arbitrary labelled content. The mechanism used to label such content is a media type, consisting of a top-level type, a subtype, and in some instances, optional parameters. Subclause F.7 and its subclauses specify such a content-labelling scheme for JPEG XR coded image sequences in the image file format specified in ISO/IEC 23008-12, to correspond with a registration in the IANA central registry. + +The file extension and media type of a file in this family usually reflect the major brand in the `FileTypeBox`. When the major brand indicates a brand related to F.5.2 (image sequence), the media type defined here should be used. When such a brand is a compatible brand, this media type may also be used. + +### **F.7.2 Registration** + +This media type may be used when the requirements of F.5.2 apply. + +Media type name: image + +Subtype name: jxrS + +Required parameters: N/A + +Optional parameters: + +Same as for the media type image/heif, as specified in ISO/IEC 23008-12. + +For JPEG XR coded image sequences, the codecs parameter contains one or both of the 'mjxr' or 'mjxs' sample entry types, and the first value of the codecs parameter should represent a track having the handler type 'pict'; other list items represent other tracks. + +Encoding considerations: binary + +Security considerations: See media type image/heif. In addition, sample entries of type 'mjxr' and 'mjxs' contain structures of variable length and have an extensible syntax. Both aspects present potential security risks for implementations. In particular, variable length structures present buffer overflow risks and extensible syntax could result in the triggering of adverse actions. + +Interoperability considerations: JPEG XR coded images can conform to one of several profiles and levels of capabilities (as specified in Annex B of Rec. ITU-T T.832 | ISO/IEC 29199-2) – not all of which may be supported by a receiving decoder. As a result, implementations may attempt to decode and display an encoded JPEG XR image only to determine that the image cannot be rendered either partially or in full. + +Published specification: + +(this Recommendation | International Standard) Rec. ITU-T T.832 (in force) | ISO/IEC 29199-2 (in force), +*Information technology – JPEG XR image coding system – Image coding specification* + +Applications: Multimedia and scientific + +Fragment identifier considerations: Same as for the media type image/heif. + +Restrictions on usage: N/A + +Additional information: + +Magic number(s): N/A + +File extension(s): jxrs + +Macintosh File Type Code(s): N/A + +Object Identifiers: N/A + +Persons to contact for further information: + +ISO/IEC JTC 1/SC 29/WG 1 Convenor (sc29-sec@itscj.ipsj.or.jp) + +Intended usage: Common + +Author/Change controller: ITU-T and ISO/IEC JTC 1 + +## Bibliography + +- Recommendation ITU-R BT.470-6 (1998) (historical), *Conventional television systems*. +- Recommendation ITU-R BT.601-7 (2011), *Studio encoding parameters of digital television for standard 4:3 and wide screen 16:9 aspect ratios*. +- Recommendation ITU-R BT.709-6 (2015), *Parameter values for the HDTV standards for production and international programme exchange*. +- Recommendation ITU-R BT.1358-0 (1998) (historical), *Studio parameters of 625 and 525 line progressive scan television systems*. +- Recommendation ITU-R BT.1358-1 (2007) (historical), *Studio parameters of 625 and 525 line progressive television systems*. +- Recommendation ITU-R BT.1361-0 (1998) (historical), *Worldwide unified colorimetry and related characteristics of future television and imaging systems*. +- Recommendation ITU-R BT.1700-0 (2005), *Characteristics of composite video signals for conventional analogue television systems*. +- Recommendation ITU-R BT.2020-2 (2015), *Parameter values for ultra-high definition television systems for production and international programme exchange*. +- Recommendation ITU-R BT.2100-2 (2018), *Image parameter values for high dynamic range television for use in production and international programme exchange*. +- Recommendation ITU-T T.81 (1992) | ISO/IEC 10918-1:1994, *Information technology – Digital compression and coding of continuous-tone still images – Requirements and guidelines*. +- ISO/IEC 9899:2018, *Information technology – Programming languages – C*. +- ISO/IEC 11578:1996, *Information technology – Open Systems Interconnection – Remote Procedure Call (RPC)*. +- ISO 11664-1:2007 (CIE S 014-1/E:2006), *Colorimetry – Part 1: CIE standard colorimetric observers*. +- ISO 12234-2:2001, *Electronic still-picture imaging – Removable memory – Part 2: TIFF/EP image data format*. +- ISO 12639:2004, *Graphic technology – Prepress digital data exchange – Tag image file format for image technology (TIFF/IT)*. +- ISO 15076-1:2010, *Image technology colour management – Architecture, profile format and data structure – Part 1: Based on ICC.1:2010*. +- ISO 16684-1:2019, *Graphic technology – Extensible metadata platform (XMP) – Part 1: Data model, serialization and core properties*. +- IEC 61966-2-1:1999 + Amd.1:2003, *Multimedia systems and equipment – Colour measurement and management – Part 2-1: Colour management – Default RGB colour space – sRGB*. +- IEC 61966-2-2:2003, *Multimedia systems and equipment – Colour measurement and management – Part 2-2: Colour management – Extended RGB colour space – scRGB*. +- IEC 61966-2-4:2006+Amd.1:2016, *Multimedia systems and equipment – Colour measurement and management – Part 2-4: Colour management – Extended-gamut YCC colour space for video applications – xvYCC*. +- ANSI CGATS/SWOP TR 003-2007 CMYK, *Graphic technology - Color characterization data for SWOP proofing and printing on U.S. Grade 3 coated publication paper*. +- ARIB3 STD-B67 (2018), *Parameter values for the hybrid log-gamma (HLG) high dynamic range television (HDR-TV) system for programme production*. +- FCC (2003), *Title 47 Code of Federal Regulations 73.682 (a) (20)*. +- ICC.1:2001-04, *File format for color profiles*. +- IETF RFC 6838 (2013), *Media type specifications and registration procedures*. + +3Association of Radio Industries and Businesses. + +- JEITA CP-3451 (2002), *Exchangeable image file format for digital still cameras: EXIF version 2.2*. +- NTSC (1953), *Recommendation for transmission standards for colour television*. +- SMPTE RP 177:1993, *SMPTE Recommended Practice – Derivation of basic television color equations*. +- SMPTE ST 170:2004, *SMPTE Standard - For television – Composite analog video signal – NTSC for studio applications*. +- SMPTE ST 240:1999, *SMPTE Standard - For television – 1125-line high-definition production systems – Signal parameters*. +- SMPTE ST 2084:2014, *SMPTE Standard - High dynamic range electro-optical transfer function of mastering reference displays*. +- SWOP2006\_Coated3v2.icc (IDEAlliance), Profile ID: f7b89b0445878f17ebb85d7515da9a98 +<[http://www.color.org/registry/SWOP2006\\_Coated3v2.xalter](http://www.color.org/registry/SWOP2006_Coated3v2.xalter)> +- TIFF Revision 6.0 (1992), Adobe Systems Incorporated +<> + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.833-201009-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg b/marked/T/T-REC-T.833-201009-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg new file mode 100644 index 0000000000000000000000000000000000000000..0ba68d777006a2ac6aa820b9fe0d93be8b360f59 --- /dev/null +++ b/marked/T/T-REC-T.833-201009-I_PDF-E/6ed175c791b5e156d9c98a8dbcc3318c_img.jpg @@ -0,0 +1,3 @@ +version https://git-lfs.github.com/spec/v1 +oid sha256:1944a1c74b9b87279bce5375d526bf646a85b3aaa7dcf3ae82a23c13e5631290 +size 6629 diff --git a/marked/T/T-REC-T.833-201009-I_PDF-E/raw.md b/marked/T/T-REC-T.833-201009-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..165603a2094e40ab528a917d3c63ce700b0732c5 --- /dev/null +++ b/marked/T/T-REC-T.833-201009-I_PDF-E/raw.md @@ -0,0 +1,390 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +**ITU-T** + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +**T.833** + +(09/2010) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES +Still-image compression – JPEG XR + +--- + +**Information technology – JPEG XR image +coding system – Motion JPEG XR** + +Recommendation ITU-T T.833 + +![ITU logo: A blue globe with red lightning bolts and the text 'ITU International Telecommunication Union'.](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with two red lightning bolts striking it. To the right of the globe, the text "ITU" is written in a large, bold, blue font, and below it, the words "International Telecommunication Union" are written in a smaller, blue font. + +ITU logo: A blue globe with red lightning bolts and the text 'ITU International Telecommunication Union'. + +# ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES** + +| | | +|-----------------------------------------------------|--------------------| +| Facsimile – Framework | T.0–T.19 | +| Still-image compression – Test charts | T.20–T.29 | +| Facsimile – Group 3 protocols | T.30–T.39 | +| Colour representation | T.40–T.49 | +| Character coding | T.50–T.59 | +| Facsimile – Group 4 protocols | T.60–T.69 | +| Telematic services – Framework | T.70–T.79 | +| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89 | +| Telematic services – ISDN Terminals and protocols | T.90–T.99 | +| Videotext – Framework | T.100–T.109 | +| Data protocols for multimedia conferencing | T.120–T.149 | +| Telewriting | T.150–T.159 | +| Multimedia and hypermedia framework | T.170–T.189 | +| Cooperative document handling | T.190–T.199 | +| Telematic services – Interworking | T.300–T.399 | +| Open document architecture | T.400–T.429 | +| Document transfer and manipulation | T.430–T.449 | +| Document application profile | T.500–T.509 | +| Communication application profile | T.510–T.559 | +| Telematic services – Equipment characteristics | T.560–T.649 | +| Still-image compression – JPEG 2000 | T.800–T.829 | +| Still-image compression – JPEG XR | T.830–T.849 | +| Still-image compression – JPEG-1 extensions | T.850–T.899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## Information technology – JPEG XR image coding system – Motion JPEG XR + +# Summary + +Recommendation ITU-T T.833 is technically aligned with ISO/IEC 29199-3 but is not published as identical text. It was drafted in collaboration with ISO/IEC JTC 1/SC 29/WG 1 (which is informally known as "JPEG"). + +This Recommendation | International Standard is the Motion JPEG XR file format specification. The Motion JPEG XR file format is designed to contain one or more motion sequences of JPEG XR images, with their timing. The format is based on the ISO base media file format. It is intended as a 'building block', specifying only the video format. An application would be expected to combine Motion JPEG XR with suitable audio, metadata, etc., for a complete application specification; that specification would normally select profiles and levels of Motion JPEG XR, and could also specify application profiles and levels that apply to the integration. + +Motion JPEG XR is expected to be used in a variety of applications, particularly where JPEG XR image coding technology is already available for other reasons, or where the high-quality frame-based approach, with no inter-frame coding, is appropriate. + +Motion JPEG XR is a flexible format, permitting a wide variety of usages, such as editing, display interchange, and streaming. + +# History + +| Edition | Recommendation | Approval | Study Group | +|---------|----------------|------------|-------------| +| 1.0 | ITU-T T.833 | 2010-09-13 | 16 | + +# FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2011 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +# CONTENTS + +| | Page | +|-------------------------------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 Normative references ..... | 1 | +| 2.1 Paired Recommendations International Standards equivalent in technical content..... | 1 | +| 2.2 Additional references ..... | 1 | +| 3 Terms and definitions ..... | 1 | +| 4 Compatibility and technology derivation ..... | 1 | +| 4.1 Family members..... | 1 | +| 4.2 Conformance ..... | 2 | +| 4.3 Profiles and levels ..... | 2 | +| 5 Motion JPEG XR sequences ..... | 2 | +| 5.1 Sample Entry and sample formats..... | 2 | +| Annex A – File and codestream profiles..... | 5 | +| A.1 Profile introduction ..... | 5 | +| A.2 Motion JPEG XR Advanced profile..... | 5 | +| A.3 Motion JPEG XR Sub-Baseline profile..... | 5 | +| A.4 Profile indicators ..... | 5 | +| Bibliography ..... | 6 | + +# Introduction + +This Recommendation | International Standard is the Motion JPEG XR specification, based on the ISO base media file format. + +This Recommendation | International Standard specifies the use of JPEG XR coding for timed sequences of images. The Motion JPEG XR file format is designed to contain one or more motion sequences of JPEG XR images, with their timing. It is intended as a 'building block', specifying only the video format. An application would be expected to combine Motion JPEG XR with suitable audio, metadata, etc., for a complete application specification; that specification would normally select profiles and levels of Motion JPEG XR, and could also specify application profiles and levels that apply to the integration. + +Motion JPEG XR is expected to be used in a variety of applications, particularly where JPEG XR coding technology is already available for other reasons, or where the high-quality frame-based approach, with no inter-frame coding, is appropriate. These application areas include: + +- digital still cameras; +- error-prone environments such as wireless and the Internet; +- video capture; +- high quality digital video recording for professional broadcasting and motion picture production from film-based to digital systems; and +- high-resolution medical and satellite imaging. + +Motion JPEG XR is a flexible format, permitting a wide variety of usages, such as editing, display, interchange, and streaming. + +This Recommendation | International Standard is technically aligned with ISO/IEC 29199-3 but is not published as identical text. + +## Information technology – JPEG XR image coding system – Motion JPEG XR + +# 1 Scope + +This Recommendation | International Standard specifies the use of JPEG XR coding for timed sequences of images (Motion JPEG XR sequences) within files based on the ISO base media file format (ISO/IEC 15444-12, technically identical to ISO/IEC 14496-12). + +# 2 Normative references + +The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations. + +## 2.1 Paired Recommendations | International Standards equivalent in technical content + +- Recommendation ITU-T T.832 (2009) | ISO/IEC 29199-2:2009, *Information technology – JPEG XR image coding system – Image coding specification*. + +## 2.2 Additional references + +- ISO 15076-1:2010, *Image technology colour management – Architecture, profile format and data structure – Part 1: Based on ICC.1:2010*. +- ISO/IEC 15444-12:2008, *Information technology – JPEG 2000 image coding system – Part 12: ISO base media file format (technically identical to ISO/IEC 14496-12)*. + +# 3 Terms and definitions + +For the purposes of this Recommendation | International Standard, the following terms and definitions apply. + +- 3.1 Motion JPEG XR sequence:** Timed sequence of JPEG XR images. + +# 4 Compatibility and technology derivation + +## 4.1 Family members + +This is a 'building block' specification; it defines how to store Motion JPEG XR sequences in a file format based on the ISO base media file format. It stands as a member of a family of specifications with common formatting. + +Since this is a building block specification, if audio is needed, then suitable audio support should be selected from other specifications using the ISO base media file format, or from the MP4 registration authority (as defined in ISO/IEC 15444-12). + +The other family members include the ISO base media file format ISO/IEC 15444-12, and file formats based on it. + +These specifications share a common definition for the structure of a file (a sequence of objects, called boxes here, and atoms in other similar file formats), and a common definition of the general structure of an object (the size and type). + +All these specifications require that readers ignore objects that are unrecognizable to them. + +This Recommendation | International Standard takes precedence over those on which it is based, in any case where there are differences or conflicts; however, no such conflicts are known to exist. + +## 4.2 Conformance + +Except as otherwise specified herein (if any such differences exist), files conforming to this Recommendation | International Standard shall conform to the file format specified in ISO/IEC 15444-12. + +Implementations of Motion JPEG XR decoders shall support the decoding of video tracks using JPEG XR coding technology (as specified in Rec. ITU-T T.832 | ISO/IEC 29199-2) in files conforming to this Recommendation | International Standard. + +Files conforming to this Recommendation | International Standard shall contain at least one Motion JPEG XR sequence. + +## 4.3 Profiles and levels + +The conformance to these restricted profiles is indicated in the file type box by the addition of the compatible profiles as brands within the compatibility list. Annex A defines the available profiles in this Recommendation | International Standard. Derived and application specifications based on this Recommendation | International Standard may define additional brands. + +# 5 Motion JPEG XR sequences + +## 5.1 Sample Entry and sample formats + +### 5.1.1 Definition + +Box Types: 'mjxr' +Container: Sample Table Box ('stbl') +Mandatory: Yes +Quantity: Exactly one + +The format of a sample when the sample entry name is 'mjxr' is a CODED\_IMAGE() as defined in Rec. ITU-T T.832 | ISO/IEC 29199-2, *without* the IMAGE\_HEADER(). Each image presented to a JPEG XR decoder is logically formed by appending the content of each sample to the content of the JPEG XR Header Box in its associated Visual Sample Entry. + +NOTE 1 – Offset values in the coded image apply to this complete set of data that is supplied to the decoder, i.e., the result of the append of the JPEG XR Header Box and the sample data. + +All images in the sequence obey the constraints of the profile and level indicators in the JPEG XR Profile Box, if present; if no specific profile is indicated, then the Advanced Profile of Rec. ITU-T T.832 | ISO/IEC 29199-2 shall be inferred. + +The values present in the VisualSampleEntry, its constituent boxes including the JPEG XR Header Box, and the codestreams that these boxes describe, must agree, to the extent that the format and precision of fields allow. This agreement includes, but is not limited to, width and height information, and the resolution declaration (within the accuracy permitted by the different representations). Files with conflicts are non-conforming and readers may attempt to decide which values are correct, or reject the file. + +The fields `horizresolution` and `vertresolution` in the Visual Sample Entry indicate the highest resolution component of the image (which is typically, but not required to be, the luminance, in an image in which not all components have the same spatial sampling density). + +If the coded images contain an alpha plane, a suitable value of 'depth', as indicated in the Visual Sample Entry, shall be used. + +NOTE 2 – Only one CODED\_IMAGE() is supported per 'mjxr' sample entry. Hence, the concept of a 'separate alpha image plane' as specified in Annex A of Rec. ITU-T T.832 | ISO/IEC 29199-2 is not supported here. + +Colour information may be supplied in one or more ColourInformationBox. These should be placed in order in the sample entry starting with the most accurate (and potentially the most expensive to process), in progression to the least. These are advisory and concern rendering and colour conversion, and there is no normative behaviour associated with them; a reader may choose to use the most suitable. A ColourInformationBox with an unknown colour type may be ignored. Values of the field `colour_type` other than those documented here are reserved. + +NOTE 3 – The ColourInformationBox is specific to the VideoSampleEntry and should not be confused with the 'colr' box defined in other standards such as the JPX File Format (see Rec. ITU-T T.801 | ISO/IEC 15444-2), which can be discriminated both by context and by the initial bytes of the box. + +The ICC profile chosen may be a restricted one, under the code 'rICC', which permits simpler processing. Such a restricted profile shall be of either the Monochrome or Three-Component Matrix-Based class of input profiles, as defined by ISO 15076-1. If the profile is of another class, then the 'prof' indicator must be used. + +NOTE 4 – If there were a need for two images in each file-format sample, for example, for support of interlaced coding or separate alpha coding, a different Visual Sample Entry name would be used. + +### 5.1.2 Syntax + +// Visual Sequences + +``` +class MJXRSampleEntry() extends VisualSampleEntry('mjxr'){ + JPEGXRInfoBox(); + JPEGXRHeaderBox(); + JPEGXRProfileBox(); // optional + ColourInformationBox(); // optional +} + +class JPEGXRInfoBox() extends FullBox('jxri', 0, version=0){ + UInt8[16] PIXEL_FORMAT; + UInt8 IMAGE_BAND_PRESENCE; + UInt8 ALPHA_BAND_PRESENCE; +} + +class JPEGXRHeaderBox() extends FullBox('jxrh', 0, version=0){ + IMAGE_HEADER(); + IsCurrPlaneAlphaFlag := FALSE; + IMAGE_PLANE_HEADER(); + if (ALPHA_IMAGE_PLANE_FLAG) { + IsCurrPlaneAlphaFlag := TRUE; + IMAGE_PLANE_HEADER(); + } +} + +class JPEGXRProfileBox() extends Box('jxrp'){ + PROFILE_LEVEL_INFO(); +} + +class ColourInformationBox extends Box('colr'){ + unsigned int(32) colour_type; + if (colour_type == 'nclx') /* on-screen colours */ + { + unsigned int(16) colour primaries; + unsigned int(16) transfer_characteristics; + unsigned int(16) matrix_coefficients; + unsigned int(1) full_range_flag; + unsigned int(7) reserved = 0; + } else if (colour_type == 'rICC') + { + ICC_profile; // restricted ICC profile + } + else if (colour_type == 'prof') + { + ICC_profile; // unrestricted ICC profile + } +} +``` + +### 5.1.3 Semantics + +In the Visual Sample Entry: + +Compressorname the value "\016Motion JPEG XR" is suggested but not required (\016 is 14, the length of the string in bytes) + +depth takes one of the following values; other values are reserved, and if found, the composition behaviour is undefined + +0x18 – images are in colour with no alpha + +0x28 – images are in grayscale with no alpha +0x20 – images have alpha (gray or colour) + +In the JPEG XR Header Box: + +IMAGE\_HEADER() as defined in clause 8.3 of Rec. ITU-T T.832 | ISO/IEC 29199-2 +IMAGE\_PLANE\_HEADER() as defined in clause 8.4 of Rec. ITU-T T.832 | ISO/IEC 29199-2 +IsCurrPlaneAlphaFlag is not a field in this structure, but a local variable used in the decoding of the +IMAGE\_PLANE\_HEADER(); +ALPHA\_IMAGE\_PLANE\_FLAG is not a field in this structure, but a field in the IMAGE\_HEADER() which is +tested here +PIXEL\_FORMAT as defined in clause A.7.18 of Rec. ITU-T T.832 | ISO/IEC 29199-2 +IMAGE\_BAND\_PRESENCE as defined in clause A.7.31 of Rec. ITU-T T.832 | ISO/IEC 29199-2 +ALPHA\_BAND\_PRESENCE as defined in clause A.7.32 of Rec. ITU-T T.832 | ISO/IEC 29199-2 + +In the JPEG XR Profile Box: + +PROFILE\_LEVEL\_INFO() as defined in clause 8.6 of Rec. ITU-T T.832 | ISO/IEC 29199-2 + +In the Colour Information Box: + +for colour\_type 'nclx': these fields are exactly the four bytes defined for PTM\_COLOR\_INFO() in clause A.7.21 +of Rec. ITU-T T.832 | ISO/IEC 29199-2 + +ICC\_profile: an ICC profile as defined, e.g., in ISO 15076-1 or ICC.1:2001-04 is supplied. + +# Annex A + +## File and codestream profiles + +(This annex forms an integral part of this Recommendation | International Standard) + +## A.1 Profile introduction + +This annex normatively specifies the Motion JPEG XR profiles. The brand of the Motion JPEG XR Advanced profile shall be in the `compatible_brands` field of the filetype box ('ftyp') in files conforming to this Recommendation | International Standard. + +## A.2 Motion JPEG XR Advanced profile + +Files conforming to the Motion JPEG XR Advanced profile have the following characteristics: + +- 1) At least one video track is present, using at least one MJXRSampleEntry. +- 2) All images conform to the Advanced profile of the JPEG XR image coding specification (Rec. ITU-T T.832 | ISO/IEC 29199-2). + +NOTE – The Motion JPEG XR Advanced Profile is a 'catch all' that permits any features of initial edition of the JPEG XR image coding specification and the ISO base media file format. + +## A.3 Motion JPEG XR Sub-Baseline profile + +Files conforming to the Motion JPEG XR Sub-Baseline profile have the following characteristics: + +- 1) All images conform to the Sub-Baseline profile of the JPEG XR image coding specification (Rec. ITU-T T.832 | ISO/IEC 29199-2). +- 2) Each track shall have exactly one sample description, used by all samples. +- 3) The file is self-contained; no data references are used, and therefore all media data is contained within the single file. +- 4) The media data in the Media Data Box(es) is placed within the box(es) in temporal order. +- 5) If more than one track is present, the media data for the tracks is interleaved, with a granularity no greater than the greater of (a) the duration of a single 'sample' (in file format terms) or (b) one second. + +## A.4 Profile indicators + +The profile indicators for these profiles are as follows. Since this is a building block specification, these would not normally be used as the `major_brand`; however, if one of these is the `major_brand`, the `minor_version` must be zero. + +| | | +|----------------------|---------| +| Advanced Profile | 'mjxr ' | +| Sub-Baseline Profile | 'mjxs ' | + +# Bibliography + +- [1] ICC.1:2001-04, *File format for color profiles*, International Color Consortium. +- [2] Recommendation ITU-T T.801 (2002) | ISO/IEC 15444-2:2004, *Information technology – JPEG 2000 image coding system – Extensions*. + + + +# SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|---------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.85-199508-I_PDF-E/raw.md b/marked/T/T-REC-T.85-199508-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..451cc062f656412a1a782cc5ccda42a71ba05942 --- /dev/null +++ b/marked/T/T-REC-T.85-199508-I_PDF-E/raw.md @@ -0,0 +1,163 @@ + + +![ITU logo: a globe with the letters ITU and a lightning bolt symbol.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU and a lightning bolt symbol. + +INTERNATIONAL TELECOMMUNICATION UNION + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +## T.85 + +(08/95) + +# TERMINALS FOR TELEMATIC SERVICES --- + +## APPLICATION PROFILE FOR RECOMMENDATION T.82 – PROGRESSIVE BI-LEVEL IMAGE COMPRESSION (JBIG CODING SCHEME) FOR FACSIMILE APPARATUS + +### ITU-T Recommendation T.85 + +(Previously "CCITT Recommendation") + +--- + +## FOREWORD + +The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. + +The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). + +ITU-T Recommendation T.85 was prepared by ITU-T Study Group 8 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 11th of August 1995. + +--- + +## NOTE + +In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +© ITU 1995 + +All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. + +## CONTENTS + +| | Page | +|-------------------------------------------------------------------|-------------| +| 1 Scope | 1 | +| 2 References | 1 | +| 3 Principle | 1 | +| 4 Application profile of single-progression sequential coding | 1 | +| 4.1 Function for facsimile application | 2 | +| 4.2 Page boundary | 2 | +| 4.3 Parameters in BIH | 2 | +| 4.4 Usage of the COMMENT marker segment | 2 | +| 5 Application profile of progressive-compatible sequential coding | 2 | +| 6 Application profile of progressive coding | 2 | + +## **SUMMARY** + +This Recommendation specifies an application profile to apply the JBIG coding scheme, defined by Recommendation T.82, for facsimile apparatus. The main specifications in this Recommendation are: + +- 1) Application profile of “single-progressive sequential coding” is defined. Other profiles (progressive coding) are for further study. +- 2) Data format consists of header information and coded information. The parameter ranges in the header are specified. + +## **APPLICATION PROFILE FOR RECOMMENDATION T.82 – PROGRESSIVE BI-LEVEL IMAGE COMPRESSION (JBIG CODING SCHEME) FOR FACSIMILE APPARATUS** + +*(Geneva, 1995)* + +## **1 Scope** + +This Recommendation defines an application profile of Recommendation T.82 “Progressive Bi-level Image Compression (JBIG coding scheme)” for facsimile apparatus. + +## **2 References** + +The following Recommendations, and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. + +- ITU-T Recommendation T.82 (1993), *Information technology – Coded representation of picture and audio information – Progressive bi-level image compression.* + +For group 3 facsimile: + +- ITU-T Recommendation T.4. +- ITU-T Recommendation T.30. + +For group 4 facsimile: + +- ITU-T Recommendation T.503. +- ITU-T Recommendation T.521. +- ITU-T Recommendation T.563. + +## **3 Principle** + +This Recommendation specifies an application profile for Recommendation T.82 for facsimile apparatus. + +Recommendation T.82 defines a method for lossless compression encoding and decoding process of a bi-level image. Recommendation T.82 has three types of coding methods: single-progression, sequential coding, progressive-compatible sequential coding and progressive coding. Application profiles for each coding type are described in clauses 4, 5 and 6. + +The use of error free transmission is mandatory for the coding scheme specified in this Recommendation. The Least Significant Bit (LSB) shall be sent first in data transmission. + +## **4 Application profile of single-progression sequential coding** + +This clause describes an application profile of single-progression sequential coding defined in Recommendation T.82 for facsimile apparatus. + +### **4.1 Function for facsimile application** + +Image data shall be processed in single-bit precision and single resolution-layer in single-progression sequential coding according to Recommendation T.82 for facsimile application. + +### **4.2 Page boundary** + +Signals of page boundaries are defined in relevant Recommendations: T.30 for Group 3 and T.521 for Group 4 facsimile. + +### **4.3 Parameters in BIH** + +Parameters in Bi-Level Image Header (BIH) are specified precisely in Recommendation T.82. In facsimile applications, within Bi-Level Image Entity (BIE), one BIH table shall be assigned to one facsimile document. + +Table 1 shows the profile of parameter setting for facsimile applications. + +The parameter sizes are defined in 6.2.2/T.82. The range of parameter values in Table 1 does not indicate the number of bits transmitted in each parameter. + +### **4.4 Usage of the COMMENT marker segment** + +COMMENT – The interpretation of the information transmitted by COMMENT marker segment depends on the implementation of both ends. + +## **5 Application profile of progressive-compatible sequential coding** + +For further study. + +## **6 Application profile of progressive coding** + +For further study. + +TABLE 1/T.85 + +| Parameter | | Value | Notes | +|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------|------------------------------------------|-------------------------------------------------------------| +| $D_L$ | initial layer to be transmitted | 0 fixed | | +| D | number of differential layers | 0 fixed | | +| P | number of bit planes | 1 fixed | | +| $X_D$ | horizontal image size at layer D | – | (See Note 2) | +| $Y_D$ | vertical image size at layer D | Full range of T.82 | | +| L0 | lines per stripe at the lowest resolution | BASIC: 128
OPTION:
from 1 to $Y_D$ | (See Note 4) | +| MX | maximum horizontal offset allowed for AT pixel | From 0 to 127 | | +| MY | maximum vertical offset allowed for AT pixel | 0 fixed | | +| HITOLO | transmission order of differential layers | 0 fixed | (See Note 1) | +| SEQ | indication of progressive-compatible sequential coding | 0 fixed | (See Note 1) | +| ILEAVE | interleaved transmission order of multiple bit plane | 0 fixed | (See Note 1) | +| SMID | transmission order of stripes | 0 fixed | (See Note 1) | +| LRLTWO | number of reference lines | 0/1 | 0: 3 lines
1: 2 lines | +| VLENGTH | indication of possible use of NEWLEN marker segment | 0/1 | 0: NEWLEN not used
1: NEWLEN may be used
(See Note 3) | +| TPDON | use of TP for Typical Prediction for differential layers | 0 fixed | (See Note 1) | +| TPBON | use of TP for base layer | 0/1 | 0: OFF
1: ON | +| DPON | use of Deterministic Prediction | 0 fixed | (See Note 1) | +| DPPRIV | use of private DP table | 0 fixed | (See Note 1) | +| DPLAST | use of last DP table | 0 fixed | (See Note 1) | +| NOTES | | | | +| 1 These parameters are not applied in single-progression sequential coding. Transmitter shall set “0” to these unused parameters. It is not necessary to recognize these parameters at receiver. | | | | +| 2 Parameter $X_D$ , horizontal image size, shall conform to the values defined in clause 2/T.4 for Group 3 facsimile and clause 3/T.563 for Group 4 facsimile. | | | | +| 3 See for 6.2.6.2/T.82. | | | | +| 4 When using this Recommendation, BASIC is 128. OPTIONS shall be negotiated by the appropriate facsimile protocol. | | | | \ No newline at end of file diff --git a/marked/T/T-REC-T.86-202402-I_PDF-E/raw.md b/marked/T/T-REC-T.86-202402-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..b155770f37a5d9a436e76a70e2feb263c423f93b --- /dev/null +++ b/marked/T/T-REC-T.86-202402-I_PDF-E/raw.md @@ -0,0 +1,255 @@ + + +# Recommendation**ITU-T T.86 (V2) (02/2024)** + +SERIES T: Terminals for telematic services + +Still-image compression – JPEG-1, Bi-level and JBIG + +--- + +**Information technology – Digital compression +and coding of continuous-tone still images: +APPn markers** + +## ITU-T T-SERIES RECOMMENDATIONS + +## Terminals for telematic services + +| | | +|------------------------------------------------------------|------------------| +| Facsimile – Framework | T.0-T.19 | +| Still-image compression – Test charts | T.20-T.29 | +| Facsimile – Group 3 protocols | T.30-T.39 | +| Colour representation | T.40-T.49 | +| Character coding | T.50-T.59 | +| Facsimile – Group 4 protocols | T.60-T.69 | +| Telematic services – Framework | T.70-T.79 | +| Still-image compression – JPEG-1, Bi-level and JBIG | T.80-T.89 | +| Telematic services – ISDN Terminals and protocols | T.90-T.99 | +| Videotext – Framework | T.100-T.109 | +| Data protocols for multimedia conferencing | T.120-T.149 | +| Telewriting | T.150-T.159 | +| Multimedia and hypermedia framework | T.170-T.189 | +| Cooperative document handling | T.190-T.199 | +| Telematic services – Interworking | T.300-T.399 | +| Open document architecture | T.400-T.429 | +| Document transfer and manipulation | T.430-T.449 | +| Document application profile | T.500-T.509 | +| Communication application profile | T.510-T.559 | +| Telematic services – Equipment characteristics | T.560-T.619 | +| General multimedia application frameworks | T.620-T.649 | +| User interfaces - Accessibility and human factors | T.700-T.799 | +| Still-image compression – JPEG 2000 | T.800-T.829 | +| Still-image compression JPEG XR | T.830-T.849 | +| Still-image compression – JPEG-1 extensions | T.850-T.899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +# **Information technology – Digital compression and coding of continuous-tone still images: APPn markers** + +## **Summary** + +This Recommendation | International Standard provides definitions for JPEG application specific markers (APPn) found in Rec. ITU-T T.81 | ISO/IEC 10918-1 and Rec. ITU-T T.84 | ISO/IEC 10918-3. + +This second edition integrates the provisions of Amendment 1 of ITU-T T.86 (2012) | ISO/IEC 10918-4 (2013) and cancels the provisions concerning the registration authority processes originally defined in the first edition. + +ITU-T T.86 is a common text with ISO/IEC 10918-4. + +## **History \*** + +| Edition | Recommendation | Approval | Study Group | Unique ID | +|---------|--------------------------|------------|-------------|--------------------| +| 1.0 | ITU-T T.86 | 1998-06-18 | 8 | 11.1002/1000/4394 | +| 1.1 | ITU-T T.86 (1998) Amd. 1 | 2012-06-29 | 16 | 11.1002/1000/11677 | +| 2.0 | ITU-T T.86 (V2) | 2024-02-13 | 16 | 11.1002/1000/15849 | + +## **Keywords** + +Application specific markers, coding, compression, continuous-tone still images, JPEG. + +--- + +\* To access the Recommendation, type the URL in the address field of your web browser, followed by the Recommendation's unique ID. + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents/software copyrights, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at . + +© ITU 2024 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## CONTENTS + +| | Page | +|---------------------------------------------------------------------|-------------| +| 1 Scope ..... | 1 | +| 2 Normative references ..... | 1 | +| 2.1 Identical ITU-T Recommendations International Standards ..... | 1 | +| 3 Definitions ..... | 1 | +| 4 Abbreviations and symbols ..... | 1 | +| 5 Conventions ..... | 1 | +| 6 General ..... | 1 | +| 7 Purpose of an APPn marker ..... | 2 | +| Annex A – Application-specific marker list ..... | 3 | +| Bibliography ..... | 4 | + + + +## **INTERNATIONAL STANDARD ITU-T RECOMMENDATION** + +# **Information technology – Digital compression and coding of continuous-tone still images: APPn markers** + +# **1 Scope** + +This Recommendation | International Standard provides definitions for JPEG application specific markers found in Rec. ITU-T T.81 | ISO/IEC 10918-1 and Rec. ITU-T T.84 | ISO/IEC 10918-3. + +# **2 Normative references** + +The following Recommendations and International Standards contain provisions which, through references in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations. + +## **2.1 Identical ITU-T Recommendations | International Standards** + +- Recommendation ITU-T T.81 | ISO/IEC 10918-1, *Information technology – Digital compression and coding of continuous-tone still images: Requirements and guidelines*. +- Recommendation ITU-T T.84 | ISO/IEC 10918-3, *Information technology – Digital compression and coding of continuous-tone still images: Extensions*. + +# **3 Definitions** + +The definitions used in Rec. ITU-T T.81 | ISO/IEC 10918-1, Rec. ITU-T T.84 | ISO/IEC 10918-3 and the following apply. + +**3.1 identifier string:** The first $m$ bytes of the application data $AP_i$ (for $i = 1$ to $m$ ) of an application marker (APPn) segment containing a zero-terminated or multi-glyph character string, generally intended to serve as a unique identifier for the APPn marker segment. + +# **4 Abbreviations and symbols** + +For the purposes of this Recommendation | International Standard, the symbols described in Rec. ITU-T T.81 | ISO/IEC 10918-1, Rec. ITU-T T.84 | ISO/IEC 10918-3 and the following abbreviation apply: + +APPn     Application specific marker segment of type n + +# **5 Conventions** + +None. + +# **6 General** + +Annex A of this Recommendation | International Standard contains a list of known application markers (APPn) along with identifier strings. APPn markers are reserved by Rec. ITU-T T.81 | ISO/IEC 10918-1 for "application use". While Rec. ITU-T T.81 | ISO/IEC 10918-1 recommends (but does not require) that these markers be removed for interchange between different application domains, readers should be aware that the markers documented in this Recommendation | International Standard are all part of the same application domain, and their removal within this domain is discouraged. Application marker segments based on the same application marker (APPn) can be disambiguated by their identifier string. During parsing, applications should skip over application marker segments they do not understand or do not plan to interpret and should preserve them when updating information. + +The intended use of the APPn marker list in Annex A is to identify those pairs of application markers and identifier strings that are reserved, to avoid conflicts when allocating application markers and to serve as a reference for implementations of Rec. ITU-T T.81 | ISO/IEC 10918-1. + +# **7 Purpose of an APPn marker** + +To make codestreams defined in Rec. ITU-T T.81 | ISO/IEC 10918-1 as flexible as possible, a provision has been made that allows applications to usefully add information to an application marker. It should be noted, however, that such use is application specific and other applications may not recognize these markers. APPn markers can be used to signal anything an application requires. They allow enhanced or expanded capabilities to be implemented. + +More precisely, the use of an APPn marker shall not prevent the expansion of the coded image when the marker is not recognized by a given implementation. The utility of the resulting image, however, can be limited by failure to recognize an APPn marker. + +NOTE – Some APPn markers have been reserved by ITU | ISO/IEC in additional Recommendations | International standards, and their use can be normatively defined there. Annex A lists some of such markers, along with their origin. + +## Annex A + +### Application-specific marker list + +(This annex forms an integral part of this Recommendation | International Standard.) + +Table A.1 lists pairs of application marker (APPn) code values and identifier strings that have been reserved. They shall only be used for the purposes described in Table A.1. The identifier string is encoded according to Rec. ITU-T T.50 or ISO/IEC 10646. + +Table A.1 – List of reserved application markers (APPn) + +| Marker | Identifier string | Description | +|--------|-------------------|-----------------------------------------------------------------------------------------------------------------| +| APP0 | JFIF | Rec. ITU-T T.871 ISO/IEC 10918-5 JPEG File Interchange Format | +| APP0 | JFXX | JFIF Extension Tags Image Thumbnail | +| APP0 | CIFF | Camera Image File Format (used by some Canon models) | +| APP0 | AVI1 | JPEG AVI (Audio Video Interleave) information | +| APP1 | EXIF | CIPA (Camera & Imaging Products Association) DC-010-2020 Exchangeable Image File Format (including maker notes) | +| APP1 | XMP | ISO 16684-1 Extensible Metadata Platform (multi-segment) | +| APP1 | QVCI | Casio QV-7000SX QVCI information | +| APP1 | PIC | Accusoft Pegasus custom fields | +| APP2 | ICC_PROFILE | ISO 15076-1 International Color Consortium (multi-segment) | +| APP2 | FPXR | FlashPix Ready (multi-segment) | +| APP2 | MPF | CIPA (Camera & Imaging Products Association) DC-007-2009 Multi-Picture Format | +| APP2 | PreviewImage | Samsung large preview (multi-segment) | +| APP3 | Kodak Meta | Kodak Meta information (EXIF-like) | +| APP3 | Stim | Stereo Still Image format | +| APP3 | PreviewImage | Hewlett-Packard or Samsung (multi-segment) preview | +| APP4 | Scalado | (presumably written by Scalado mobile software) | +| APP4 | FPXR | FlashPix Ready in non-standard location (multi-segment) | +| APP4 | PreviewImage | Continued Samsung preview from APP3 | +| APP5 | Ricoh RMETA | Ricoh custom fields | +| APP6 | EPPIM | Toshiba PrintIM | +| APP6 | NITF | National Imagery Transmission Format | +| APP6 | HP TDHD | Hewlett-Packard Photosmart R837 TDHD information | +| APP7 | NITF0003.A | NITF (National Imagery Transmission Format) directory data segment | +| APP8 | SPIFF | Rec. ITU-T T.84 ISO/IEC 10918-3 Still Picture Interchange File Format | +| APP10 | Comment | PhotoStudio Unicode Comment | +| APP11 | DD | ISO/IEC 18477-2 Still image extension | +| APP11 | JP | ISO/IEC 18477-3 ISO/IEC 19566-5 ISO Box-Based Format Extensions | +| APP12 | Picture Info | Textual Picture Information | +| APP12 | Ducky | Photoshop "Save for Web" | +| APP13 | Photoshop IRB | Image Resource Block (multi-segment, includes IPTC) | +| APP13 | Adobe CM | Adobe Color Management | +| APP14 | Adobe | Adobe DCT filter, identical to ISO/IEC 18477-1 Component Decorrelation Control marker | +| APP15 | GraphicConverter | GraphicConverter quality | + +# Bibliography + +- Recommendation ITU-T T.50, *International Reference Alphabet (IRA) (Formerly International Alphabet No. 5 or IA5) – Information technology – 7-bit coded character set for information interchange*. +- Recommendation ITU-T T.84 | ISO/IEC 10918-3, *Information technology – Digital compression and coding of continuous-tone still images: Extensions*. +- Recommendation ITU-T T.871 | ISO/IEC 10918-5, *Information technology – Digital compression and coding of continuous-tone still images: JPEG File Interchange Format (JFIF)*. +- ISO 15076-1, *Image technology colour management – Architecture, profile format and data structure – Part 1: Based on ICC.1:2010*. +- ISO 16684-1, *Graphic technology – Extensible metadata platform (XMP) – Part 1: Data model, serialization and core properties*. +- ISO/IEC 10646-1, *Information technology – Universal Multiple-Octet Coded Character Set (UCS) – Part 1: Architecture and Basic Multilingual Plane*. +- ISO/IEC 18477-1, *Information technology – Scalable compression and coding of continuous-tone still images – Part 1: Core coding system specification*. +- ISO/IEC 18477-2, *Information technology – Scalable compression and coding of continuous-tone still images – Part 2: Coding of high dynamic range images*. +- ISO/IEC 18477-3, *Information technology – Scalable compression and coding of continuous-tone still images – Part 3: Box file format*. +- ISO/IEC 19566-5, *Information technologies – JPEG systems – Part 5: JPEG universal metadata box format (JUMBF)*. +- CIPA DC-007-2009 – *Multi-Picture Format*. +- CIPA DC-010-2020 – *Exif2.32 metadata for XMP*. +- National Imagery Transmission Format Standard (NITFS) – *Bandwidth Compression Standards and Guidelines*. + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | Tariff and accounting principles and international telecommunication/ICT economic and policy issues | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Environment and ICTs, climate change, e-waste, energy efficiency; construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Telephone transmission quality, telephone installations, local line networks | +| Series Q | Switching and signalling, and associated measurements and tests | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects, next-generation networks, Internet of Things and smart cities | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.871-201105-I_PDF-E/raw.md b/marked/T/T-REC-T.871-201105-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..89c96e34054060e3ac4cfbf75cc3fdd08043e9ac --- /dev/null +++ b/marked/T/T-REC-T.871-201105-I_PDF-E/raw.md @@ -0,0 +1,476 @@ + + +I n t e r n a t i o n a l   T e l e c o m m u n i c a t i o n   U n i o n + +# ITU-T + +TELECOMMUNICATION +STANDARDIZATION SECTOR +OF ITU + +# T.871 + +(05/2011) + +SERIES T: TERMINALS FOR TELEMATIC SERVICES +Still-image compression – JPEG-1 extensions + +--- + +**Information technology – Digital compression +and coding of continuous-tone still images: +JPEG File Interchange Format (JFIF)** + +Recommendation ITU-T T.871 + +![ITU logo: a globe with red lightning bolts and the text 'ITU International Telecommunication Union'](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +The logo of the International Telecommunication Union (ITU) is located in the bottom right corner. It features a blue globe with two red lightning bolts striking it. To the right of the globe, the text "ITU" is written in a large, bold, blue font, and below it, the words "International Telecommunication Union" are written in a smaller, blue font. + +ITU logo: a globe with red lightning bolts and the text 'ITU International Telecommunication Union' + +# ITU-T T-SERIES RECOMMENDATIONS **TERMINALS FOR TELEMATIC SERVICES** + +| | | +|-----------------------------------------------------|--------------------| +| Facsimile – Framework | T.0–T.19 | +| Still-image compression – Test charts | T.20–T.29 | +| Facsimile – Group 3 protocols | T.30–T.39 | +| Colour representation | T.40–T.49 | +| Character coding | T.50–T.59 | +| Facsimile – Group 4 protocols | T.60–T.69 | +| Telematic services – Framework | T.70–T.79 | +| Still-image compression – JPEG-1, Bi-level and JBIG | T.80–T.89 | +| Telematic services – ISDN Terminals and protocols | T.90–T.99 | +| Videotext – Framework | T.100–T.109 | +| Data protocols for multimedia conferencing | T.120–T.149 | +| Telewriting | T.150–T.159 | +| Multimedia and hypermedia framework | T.170–T.189 | +| Cooperative document handling | T.190–T.199 | +| Telematic services – Interworking | T.300–T.399 | +| Open document architecture | T.400–T.429 | +| Document transfer and manipulation | T.430–T.449 | +| Document application profile | T.500–T.509 | +| Communication application profile | T.510–T.559 | +| Telematic services – Equipment characteristics | T.560–T.649 | +| Still-image compression – JPEG 2000 | T.800–T.829 | +| Still-image compression – JPEG XR | T.830–T.849 | +| Still-image compression – JPEG-1 extensions | T.850–T.899 | + +*For further details, please refer to the list of ITU-T Recommendations.* + +## **Information technology – Digital compression and coding of continuous-tone still images: JPEG File Interchange Format (JFIF)** + +## Summary + +Recommendation ITU-T T.871 | ISO/IEC 10918-5 specifies a file format, referred to as the JPEG File Interchange Format (JFIF), for file-based interchange of images encoded according to the JPEG image coding standard (Recommendation ITU-T T.81 | ISO/IEC 10918-1). This Recommendation | International Standard is substantially based on the JFIF version 1.02 specification that was produced in 1992. The JFIF version 1.02 specification was widely and freely circulated, and became widely recognized as a *de facto* standard. This Recommendation | International Standard was developed primarily to formalize the JFIF version 1.02 specification. + +## History + +| Edition | Recommendation | Approval | Study Group | +|---------|----------------|------------|-------------| +| 1.0 | ITU-T T.871 | 2011-05-14 | 16 | + +## FOREWORD + +The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. + +The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. + +In some areas of information technology which fall within ITU-T's purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. + +## NOTE + +In this Recommendation, the expression "Administration" is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. + +Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other obligatory language such as "must" and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. + +## INTELLECTUAL PROPERTY RIGHTS + +ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. + +As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at . + +© ITU 2012 + +All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. + +## Table of Contents + +| | | Page | +|----|-------------------------------------------------------------------------------------------|-------------| +| 1 | Scope ..... | 1 | +| 2 | Normative references ..... | 1 | +| | 2.1 Identical Recommendations International Standards ..... | 1 | +| | 2.2 Paired Recommendations International Standards equivalent in technical content..... | 1 | +| | 2.3 Additional references ..... | 1 | +| 3 | Definitions ..... | 1 | +| 4 | Abbreviations ..... | 1 | +| 5 | Conformance ..... | 2 | +| 6 | JPEG File Interchange Format (JFIF) overview ..... | 2 | +| | 6.1 JPEG compression ..... | 2 | +| | 6.2 Colour space..... | 2 | +| | 6.3 JFIF APP 0 marker segment ..... | 3 | +| | 6.4 APP 0 marker used to specify JFIF extensions..... | 3 | +| | 6.5 Application marker segments used for application-specific information ..... | 3 | +| 7 | Conversion to and from RGB..... | 3 | +| 8 | Image orientation..... | 4 | +| 9 | Spatial relationship of components..... | 4 | +| 10 | JPEG File Interchange Format (JFIF) specification ..... | 6 | +| | 10.1 JFIF file syntax..... | 6 | +| | 10.2 JFIF extension APP 0 marker segment ..... | 7 | +| | 10.3 JFIF extension: Thumbnail coded using JPEG encoding ..... | 7 | +| | 10.4 JFIF extension: Thumbnail stored using one byte per pixel..... | 8 | +| | 10.5 JFIF extension: Thumbnail stored using three bytes per pixel ..... | 8 | +| | Bibliography ..... | 9 | + + + +## **INTERNATIONAL STANDARD RECOMMENDATION ITU-T** + +## **Information technology – Digital compression and coding of continuous-tone still images: JPEG File Interchange Format (JFIF)** + +# **1 Scope** + +This Recommendation | International Standard specifies the JPEG File Interchange Format (JFIF). + +The JPEG File Interchange Format (JFIF) is a minimal file format which enables the exchange of JPEG encoded images (according to Rec. ITU-T T.81 | ISO/IEC 10918-1) having 1 or 3 colour channels and 8 bits per colour channel between a wide variety of platforms and applications. This minimal format does not include some advanced features found in various other specified file formats. The purpose of this format is to provide for a basic form of exchange of JPEG images. The optional inclusion of thumbnail images for rapid browsing is also supported. + +# **2 Normative references** + +The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations. + +### **2.1 Identical Recommendations | International Standards** + +- Recommendation ITU-T T.81 (1992) | ISO/IEC 10918-1:1994, *Information technology – Digital compression and coding of continuous-tone still images – Requirements and guidelines*. + +### **2.2 Paired Recommendations | International Standards equivalent in technical content** + +None. + +### **2.3 Additional references** + +- Recommendation ITU-R BT.601-6 (2007), *Studio encoding parameters of digital television for standard 4:3 and wide screen 16:9 aspect ratios*. + +# **3 Definitions** + +For the purposes of this Recommendation | International Standard, the following definitions apply. + +**3.1 JPEG File Interchange Format (JFIF):** The interchange format specified in this Recommendation | International Standard for exchange of images encoded according to the JPEG standard (Rec. ITU-T T.81 | ISO/IEC 10918-1) having 1 or 3 colour channels and 8 bits per colour channel. + +**3.2 thumbnail:** Reduced resolution representation of the main JPEG (Rec. ITU-T T.81 | ISO/IEC 10918-1) coded image that can be used to identify the image by its content. + +NOTE – Thumbnails are commonly used to browse multiple images quickly using a low resolution visual representation of the images, rather than using file names or other metadata. + +## **4 Abbreviations** + +For the purposes of this Recommendation | International Standard, the following abbreviations apply. + +- | | | +|------------------|---------------------------------| +| Ap i | Byte i of application data | +| APP 0 | Application data marker, type 0 | + +| | | +|-------------|------------------------------------------------------------------------------------------------------------| +| EOI | End of Image | +| ICC | International Color Consortium | +| JFIF | JPEG File Interchange Format | +| JPEG | Joint Photographic Experts Group | +| Lf | Length of frame header | +| Lp | Length of application data segment | +| Nf | Number of components in frame | +| RGB | Red, Green, and Blue (colour component values) | +| SOF | Start of Frame | +| SOI | Start of Image | +| $Y C_B C_R$ | Luminance (denoted as $Y$ ), Chrominance toward Blue, and Chrominance toward Red (colour component values) | + +## 5 Conformance + +Some requirements in this Recommendation | International Standard are expressed as format or syntax requirements rather than as software or hardware implementation requirements. Implementations fall into two categories: JFIF decoders and JFIF encoders. + +In order for a JFIF decoder to be considered conforming, the decoder shall not report errors when processing conforming instances of the specified format, except when forced to do so by resource exhaustion or when the encoded image data uses non-baseline features of Rec. ITU-T T.81 | ISO/IEC 10918-1 that are not supported by the decoder. + +NOTE – The decoder should report errors when processing non-conforming deviations from the specified format. + +In order for a JFIF encoder to be considered conforming, the files produced by the encoder shall be formatted as specified. + +## 6 JPEG File Interchange Format (JFIF) overview + +## 6.1 JPEG compression + +Any JPEG (Rec. ITU-T T.81 | ISO/IEC 10918-1) process is supported by the syntax of the JPEG File Interchange Format (JFIF), provided the encoded image has 1 or 3 colour channels and 8 bits per colour channel. + +NOTE 1 – It is strongly recommended that the JPEG baseline process, as defined in Rec. ITU-T T.81 | ISO/IEC 10918-1, be used for the purposes of file interchange. This ensures maximum compatibility among applications supporting JPEG coded images. + +Files conforming to the JPEG File Interchange Format shall conform to the interchange format specified in Rec. ITU-T T.81 | ISO/IEC 10918-1. The encoded image in the JPEG File Interchange Format shall have 1 or 3 colour channels and 8 bits per colour channel. Additionally, the JFIF APP0 marker (see 6.4) shall be present immediately following the SOI marker (specified in Rec. ITU-T T.81 | ISO/IEC 10918-1). + +NOTE 2 – The interchange format specified in Rec. ITU-T T.81 | ISO/IEC 10918-1 requires that all table specifications used in the encoding process are coded in the image data prior to their use. + +### 6.2 Colour space + +The colour space to be used is $Y C_B C_R$ as defined by Rec. ITU-R BT.601 (256 levels) but with a different scaling as specified below. If only one component is used, that component shall be the $Y$ component channel as specified below. + +NOTE – The colour space specification herein can provide only a basic level of colour fidelity. The use of supplemental metadata such as an ICC profile (e.g., as specified in ISO 15076-1) may be necessary to provide a more accurate colour characterization. + +If three components are used, they shall be present in the image with the ordering of the components such that the first component is the $Y$ channel, the second component is the $C_B$ channel, and the third component is the $C_R$ channel. + +### 6.3 JFIF APP0 marker segment + +The JFIF APP0 marker segment shall immediately follow the SOI marker. The JFIF APP0 marker segment is defined as an APP0 marker (specified in Rec. ITU-T T.81 | ISO/IEC 10918-1) containing the null-terminated string: "JFIF" encoded as specified in 10.1 in the first five application data bytes of the marker segment (Api, for i = 1 to 5). Additional APP0 marker segments may also be present, provided the associated application data bytes do not begin with this string. The JFIF APP0 marker segment provides some information that is not contained in the JPEG (Rec. ITU-T T.81 | ISO/IEC 10918-1) stream, such as: version number, horizontal and vertical pixel densities (expressed in dots per inch or dots per cm), pixel aspect ratio (derived from the horizontal and vertical pixel densities), and an optional thumbnail encoded as 24-bit *RGB* image data. + +NOTE – The "JFIF" string as specified in 10.1 is encoded according to Rec. ITU-T T.50 | ISO 646. + +### 6.4 APP0 marker used to specify JFIF extensions + +Additional APP0 marker segment(s) can optionally be used for the JFIF extensions specified in clause 10. If used, these segment(s) must immediately follow the JFIF APP0 marker segment. Decoders shall skip any unsupported JFIF extension segments and continue decoding. The JFIF extension APP0 marker is identified by the zero-terminated string "JFXX" encoded as specified in 10.2 in the first five application data bytes of the marker segment (Api, for i = 1 to 5). The JFIF extension APP0 marker segment contains a 1-byte code with a value specified in clause 10 that identifies the particular extension type. + +NOTE – The encoding of the "JFXX" string as specified in 10.2 is encoded according to Rec. ITU-T T.50 | ISO 646. + +### 6.5 Application marker segments used for application-specific information + +Additional APP0 and other application marker segments may be used to hold application-specific information that does not affect the ability to decode or display the JFIF file segment. Application-specific marker segments must appear after the JFIF APP0 and any JFIF extension APP0 marker segments. Application-specific APP0 marker segments shall contain application data bytes such that the initial application data bytes contain a zero-terminated string value that identifies the application. For application-specific APP0 marker segments, this string shall not be the zero-terminated string values "JFIF" as specified in 10.1 or "JFXX" as specified in 10.2, to avoid conflict with this Recommendation | International Standard. It is recommended that this string represent an organization name or company trademark. Generic strings such as "dog", "cat", "tree", etc., should not be used. + +## 7 Conversion to and from *RGB* + +The interpretations of $Y$ , $C_B$ , and $C_R$ are derived from the $E'_Y$ , $E'_{C_B}$ , and $E'_{C_R}$ signals defined in the 625-line specification of Rec. ITU-R BT.601, but these signals are normalized so as to permit the usage of the full range of 256 levels of the 8-bit binary encoding of the $Y$ component. More precisely, they are specified by the following relationships: + +$$Y = \text{Min}(\text{Max}(0, \text{Round}(255 * E'_Y)), 255)$$ + +$$C_B = \text{Min}(\text{Max}(0, \text{Round}(255 * E'_{C_B} + 128)), 255)$$ + +$$C_R = \text{Min}(\text{Max}(0, \text{Round}(255 * E'_{C_R} + 128)), 255)$$ + +using the following mathematical definitions: + +$$\text{Round}(x) = \lfloor x + 0.5 \rfloor$$ + +$$\text{Min}(x, y) = \begin{cases} x & ; \quad x \leq y \\ y & ; \quad x > y \end{cases}$$ + +$$\text{Max}(x, y) = \begin{cases} x & ; \quad x \geq y \\ y & ; \quad x < y \end{cases}$$ + +where the $E'_Y$ , $E'_{C_B}$ and $E'_{C_R}$ are defined as in Rec. ITU-R BT.601. Values of $E'_Y$ have a nominal range of 0.0 to 1.0 and those for $E'_{C_B}$ and $E'_{C_R}$ have a nominal range of –0.5 to +0.5 for conventional colorimetry. The values of $Y$ , $C_B$ , and $C_R$ must be clamped to the range from 0 to 255 as shown above. $YC_B C_R$ colours (with 256 levels per component) can alternatively be computed directly from full scale 8-bit per colour channel *RGB* colours in which black is represented by (0, 0, 0) and white is represented by (255, 255, 255) by using the following formulae: + +$$\begin{aligned} Y &= \text{Min}(\text{Max}(0, \text{Round}(0.299 * R + 0.587 * G + 0.114 * B)), 255) \\ C_B &= \text{Min}(\text{Max}(0, \text{Round}((-0.299 * R - 0.587 * G + 0.886 * B) / 1.772 + 128)), 255) \\ C_R &= \text{Min}(\text{Max}(0, \text{Round}((0.701 * R - 0.587 * G - 0.114 * B) / 1.402 + 128)), 255) \end{aligned}$$ + +which, to four decimal position accuracy, can be approximated by: + +$$\begin{aligned} Y &= \text{Min}(\text{Max}(0, \text{Round}(0.299 * R + 0.587 * G + 0.114 * B)), 255) \\ C_B &= \text{Min}(\text{Max}(0, \text{Round}(-0.1687 * R - 0.3313 * G + 0.5 * B + 128)), 255) \\ C_R &= \text{Min}(\text{Max}(0, \text{Round}(0.5 * R - 0.4187 * G - 0.0813 * B + 128)), 255) \end{aligned}$$ + +NOTE 1 – Not all image file formats store image samples in the order $R_0, G_0, B_0, \dots, R_n, G_n, B_n$ . The sample order must be verified before converting an *RGB* file to JFIF. + +The inverse relationship for computing full scale 8-bit per colour channel gamma pre-corrected *RGB* values (following Rec. ITU-R BT.601 gamma pre-correction and colour primary specifications) from $Y C_B C_R$ colours (with 256 levels per component) can be computed as follows: + +$$\begin{aligned} R &= \text{Min}(\text{Max}(0, \text{Round}(Y + 1.402 * (C_R - 128))), 255) \\ G &= \text{Min}(\text{Max}(0, \text{Round}(Y - (0.114 * 1.772 * (C_B - 128) + 0.299 * 1.402 * (C_R - 128)) / 0.587)), 255) \\ B &= \text{Min}(\text{Max}(0, \text{Round}(Y + 1.772 * (C_B - 128))), 255) \end{aligned}$$ + +which, to four decimal position accuracy, can be approximated by: + +$$\begin{aligned} R &= \text{Min}(\text{Max}(0, \text{Round}(Y + 1.402 * (C_R - 128))), 255) \\ G &= \text{Min}(\text{Max}(0, \text{Round}(Y - 0.3441 * (C_B - 128) - 0.7141 * (C_R - 128))), 255) \\ B &= \text{Min}(\text{Max}(0, \text{Round}(Y + 1.772 * (C_B - 128))), 255) \end{aligned}$$ + +The *RGB* values used for representation of thumbnails stored in JFIF files as specified in clauses 10.1, 10.4, or 10.5 are interpreted according to this full-scale (256 levels per component) convention, in which black is represented by (0, 0, 0) and white is represented by (255, 255, 255). + +NOTE 2 – The definition of 8-bit per colour channel *RGB* values in digital form as used in these equations differs from the one used in Rec. ITU-R BT.601, as the definition used here assumes full-scale 256-level usage in which black is represented by (0, 0, 0) and white is represented by (255, 255, 255), whereas in Rec. ITU-R BT.601, nominal *RGB* black is represented by (16, 16, 16) and nominal white is represented by (235, 235, 235). + +NOTE 3 – As this Recommendation | International Standard is based on the prior informally-circulated JFIF version 1.02 specification that was produced in 1992, which referenced Rec. ITU-R BT.601 (formerly CCIR 601), it references that specification for definition of the $E'_Y, E'_{C_B},$ and $E'_{C_R}$ signals that correspond to the $Y C_B C_R$ values specified herein. However, since the development of the prior JFIF version 1.02 specification, additional industry specifications have been developed, Rec. ITU-R BT.601 has been updated, and common industry practice has emerged which often follows the sYCC specification in IEC 61966-2-1/Amd.1. The difference between the use of the colour interpretation specification in this Recommendation | International Standard and that of the sYCC specification may be considered negligible in practice. Moreover, as previously noted, the colour space specification herein can provide only a basic level of colour fidelity. The use of supplemental metadata such as an ICC profile (e.g., as specified in ISO 15076-1) may be necessary to provide a more accurate colour characterization. + +## 8 Image orientation + +In JFIF files, the image orientation is always top-down (in terms of human viewing intent). This means that the first image samples encoded in a JFIF file are located in the upper left hand corner of the image and encoding proceeds from left to right and top to bottom. Top-down orientation is used for both full resolution images and thumbnails. The process of converting an image file having bottom-up orientation to JFIF should include inverting the order of all image lines before Rec. ITU-T T.81 | ISO/IEC 10918-1 encoding. + +## 9 Spatial relationship of components + +Specification of the spatial positioning of pixel samples within components relative to the samples of other components is necessary for proper image post processing and accurate image presentation. In JFIF files, the position of the pixels in sub-sampled components is defined with respect to the highest resolution component. Since components must be sampled orthogonally (along rows and columns), the spatial position of the samples in a given sub-sampled component may be determined by specifying the horizontal and vertical offsets of the first sample, i.e., the sample in the upper left corner, with respect to the highest-resolution component. + +The horizontal and vertical offsets of the position of the first sample in a sub-sampled component, $\text{Hoffset}_i[0,0]$ and $\text{Voffset}_i[0,0]$ , relative to the position of the upper left sample for the largest component, are defined as follows: + +$$\text{Hoffset}_i[0,0] = ( \text{Nsamples}_{\text{ref}} / \text{Nsamples}_i ) / 2 - 0.5$$ + +$$\text{Voffset}_i[0,0] = ( \text{Nlines}_{\text{ref}} / \text{Nlines}_i ) / 2 - 0.5$$ + +where: + +$\text{Nsamples}_{\text{ref}}$ is the number of samples per line in the largest component; + +$\text{Nsamples}_i$ is the number of samples per line in the $i$ -th component; + +$\text{Nlines}_{\text{ref}}$ is the number of lines in the largest component; + +$\text{Nlines}_i$ is the number of lines in the $i$ -th component. + +As used here, the division operator "/" produces a real-valued result without truncation or rounding. + +NOTE 1 – Proper sub-sampling of components incorporates an anti-aliasing filter, which reduces the spectral bandwidth of a full resolution component prior to sub-sampling of that component. Sub-sampling can easily be accomplished using a symmetrical digital filter with an even number of taps (coefficients). A commonly used filter for 2:1 sub sampling utilizes two taps (1/2, 1/2). + +As an example, consider a three-component image which is comprised of components having the following dimensions: + +- Component 1: 256 samples, 288 lines; +- Component 2: 128 samples, 144 lines; +- Component 3: 64 samples, 96 lines. + +For a JFIF file, the centres of the samples of such an image would be positioned as illustrated below in Figure 1: + +![Figure 1: Centres of the samples of three components. The diagram shows a grid of sample positions. Component 1 (Component 1) is represented by 'x' marks. Component 2 (Component 2) is represented by squares. Component 3 (Component 3) is represented by circles. The grid is 4x4. Component 1 samples are at (1,1), (1,2), (1,3), (1,4), (2,1), (2,2), (2,3), (2,4), (3,1), (3,2), (3,3), (3,4), (4,1), (4,2), (4,3), (4,4). Component 2 samples are at (2,1), (2,3), (3,1), (3,3). Component 3 samples are at (2,2), (3,2).](536951b2bbd94325ae266d8d1363df8f_img.jpg) + +× Component 1      □ Component 2      ○ Component 3 + T.871(11)\_F01 + +Figure 1: Centres of the samples of three components. The diagram shows a grid of sample positions. Component 1 (Component 1) is represented by 'x' marks. Component 2 (Component 2) is represented by squares. Component 3 (Component 3) is represented by circles. The grid is 4x4. Component 1 samples are at (1,1), (1,2), (1,3), (1,4), (2,1), (2,2), (2,3), (2,4), (3,1), (3,2), (3,3), (3,4), (4,1), (4,2), (4,3), (4,4). Component 2 samples are at (2,1), (2,3), (3,1), (3,3). Component 3 samples are at (2,2), (3,2). + +**Figure 1 – Centres of the samples of three components** + +NOTE 2 – While this definition matches some industry specifications, it differs from the convention used for $C_B$ and $C_R$ colour component sub-sampling in Rec. ITU-R BT.601 and a number of other digital video formats. In practice, the difference may be considered negligible, or pre-processing of the chrominance components may be performed to produce a more accurate reconstruction of the compressed image. + +NOTE 3 – In common industry usage, only two forms of colour component sub-sampling are typically encountered in practice for three-component images. The most common of these forms is known as 4:2:0, in which the $C_B$ and $C_R$ colour components are sub-sampled by a factor of two in both the horizontal and vertical dimensions. The other relatively-common form is known as 4:2:2, in which the $C_B$ and $C_R$ colour components are sub-sampled by a factor of two in the horizontal dimension only. The 4:2:2 form of sub-sampling is used primarily for video-related applications (especially with the use of interlaced-scan systems). For JFIF usage, the use of sub-sampling formats other than 4:2:0 is therefore discouraged, as such other formats may not be supported in some applications. + +## 10 JPEG File Interchange Format (JFIF) specification + +### 10.1 JFIF file syntax + +The syntax of a JFIF file shall conform to the syntax for the interchange format as specified in Annex B of Rec. ITU-T T.81 | ISO/IEC 10918-1. In addition, a JFIF file shall contain APP0 marker segments with certain parameter constraints in the frame header as specified below. Values are represented using unsigned binary representations except as otherwise specified. X'nn' indicates a byte value in hexadecimal notation. Fields that follow the Lp parameter as specified below shall appear in the sequence listed below in the application data bytes Api of the JFIF APP0 marker segment. + +X'FF', SOI + +X'FF', APP0, Lp, identifier, version, units, Hdensity, Vdensity, HthumbnailA, VthumbnailA, (RGB) \* n + +| | | | +|-------------|---------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Lp | (2 bytes) | Total APP 0 field byte count, including the byte count value (2 bytes), but excluding the APP 0 marker itself. Shall be equal to $16 + 3 * k$ , with $k = HthumbnailA * VthumbnailA$ . | +| identifier | (5 bytes) | = X'4A', X'46', X'49', X'46', X'00'
This zero-terminated string ("JFIF", according to Rec. ITU-T T.50 or ISO 646 coding) identifies the JFIF APP 0 marker. | +| version | (2 bytes) | = X'0102'
The most significant byte is used for major revisions, the least significant byte for minor revisions. Files encoded according to this Recommendation International Standard shall use the value X'0102' (corresponding to version 1.02). | +| units | (1 byte) | Units for the H (horizontal) and V (vertical) densities:

= X'00': units unspecified; H and V densities, expressed in dots per arbitrary unit, specify only the pixel aspect ratio (width:height pixel aspect ratio = Vdensity:Hdensity).

= X'01': H and V densities are dots per inch (dots per 2.54 cm).

= X'02': H and V densities are dots per cm. | +| Hdensity | (2 bytes) | Horizontal pixel density. Must be non-zero. | +| Vdensity | (2 bytes) | Vertical pixel density. Must be non-zero. | +| HthumbnailA | (1 byte) | Horizontal thumbnail pixel count. May be zero. | +| VthumbnailA | (1 byte) | Vertical thumbnail pixel count. May be zero. | +| (RGB) * k | (3 * k bytes) | Packed (byte-interleaved) 24-bit RGB values (8 bits per colour channel) for the thumbnail pixels, in the order $R_0, G_0, B_0, \dots, R_k, G_k, B_k$ , with $k = HthumbnailA * VthumbnailA$ . | + +[ Optional JFIF extension APP0 marker segment(s) – see below ] + +- +- +- + +X'FF', SOFn, Lf, etc., according to the interchange format of Annex B of Rec. ITU-T T.81 | ISO/IEC 10918-1, with constraints as follows: + +| | | | +|-----------------------------|----------------|-----------------------------------------------------| +| Number of components | Nf | = 1 or 3 | +| 1st component | C 1 | = 1 = Y component | +| 2nd component (when Nf = 3) | C 2 | = 2 = CB component (when present) | +| 3rd component (when Nf = 3) | C 3 | = 3 = CR component (when present) | +| • | | | +| • | | | +| • | | | + +X'FF', EOI + +If HthumbnailA or VthumbnailA is equal to zero, this indicates that the thumbnail is not present in the marker segment. + +### 10.2 JFIF extension APP0 marker segment + +One or more JFIF extension APP0 markers may immediately follow the JFIF APP0 marker segment. The syntax of the JFIF extension APP0 marker segment shall be as follows. Fields that follow the Lp parameter as specified below shall appear in the sequence listed below in the application data bytes Api of the JFIF extension APP0 marker segment. + +X'FF', APP0, Lp, identifier, extension\_code, extension\_data + +| | | | +|----------------|------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| Lp | (2 bytes) | Total APP 0 field byte count, including the byte count value (2 bytes), but excluding the APP 0 marker itself. Shall be equal to the number of bytes of extension_data plus 8. | +| identifier | (5 bytes) | = X'4A', X'46', X'58', X'58', X'00'
This zero-terminated string ("JFXX", according to Rec. ITU-T T.50 or ISO 646 coding) identifies the JFIF extension APP 0 marker. | +| extension_code | (1 byte) | Code that identifies the extension. In this version, the following extensions are defined (see 10.3-10.5 for detailed definitions):

= X'10' Thumbnail coded according to the baseline process specification in Rec. ITU-T T.81 ISO/IEC 10918-1 (see 10.3).

= X'11' Uncompressed 8-bit palette RGB thumbnail (see 10.4).

= X'13' Uncompressed 24-bit RGB thumbnail (see 10.5). | +| extension_data | (variable) | The remainder of the JFIF extension APP 0 marker segment, which varies according to the extension_code. See below for a specification of extension_data content for each extension. | + +### 10.3 JFIF extension: Thumbnail coded using JPEG encoding + +This extension supports thumbnails encoded using the baseline process specification in Rec. ITU-T T.81 | ISO/IEC 10918-1. The encoded thumbnail is placed in the extension\_data field. + +The syntax of the content of the extension\_data shall conform to the syntax for the interchange format defined in Annex B of Rec. ITU-T T.81 | ISO/IEC 10918-1. However, no JFIF or JFIF extension marker segments shall be present within the thumbnail data. As in the full resolution image of the JFIF file, the syntax within the extension\_data shall be constrained as specified below: + +X'FF', SOI + +- +- +- + +X'FF', SOFn, Lf, etc., according to the interchange format of Annex B of Rec. ITU-T T.81 | ISO/IEC 10918-1, with constraints as follows: + +| | | | +|-----------------------------|----------------|-----------------------------------------------------| +| Number of components | Nf | = 1 or 3 | +| 1st component | C 1 | = 1 = Y component | +| 2nd component (when Nf = 3) | C 2 | = 2 = CB component (when present) | +| 3rd component (when Nf = 3) | C 3 | = 3 = CR component (when present) | +| • | | | +| • | | | +| • | | | + +X'FF', EOI + +The number of components of the JPEG (Rec. ITU-T T.81 | ISO/IEC 10918-1) encoded thumbnail may be different from the number of components for the main image. + +### 10.4 JFIF extension: Thumbnail stored using one byte per pixel + +This extension supports thumbnails stored using one byte per pixel and a colour palette in the extension\_data field. The syntax of the content of the extension\_data shall be as follows: + +| | | | +|-------------|-------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------| +| HthumbnailB | (1 byte) | Horizontal thumbnail pixel count. Must be non-zero. | +| VthumbnailB | (1 byte) | Vertical thumbnail pixel count. Must be non-zero. | +| Palette | (768 bytes) | 24-bit RGB pixel values for the colour palette. The RGB values define the colours represented by each value of an 8-bit binary encoding (0-255). | +| (pixel) * m | (m bytes) | 8-bit palette indices for the thumbnail pixels
m = HthumbnailB * VthumbnailB. | + +### 10.5 JFIF extension: Thumbnail stored using three bytes per pixel + +This extension supports thumbnails stored using three bytes per pixel in the extension\_data field. The syntax of the content of the extension\_data shall be as follows: + +| | | | +|--------------------|---------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| HthumbnailC | (1 byte) | Horizontal thumbnail pixel count. Must be non-zero. | +| VthumbnailC | (1 byte) | Vertical thumbnail pixel count. Must be non-zero. | +| ( RGB ) * n | (3 * n bytes) | Packed (byte-interleaved) 24-bit RGB values (8 bits per colour channel) for the thumbnail pixels, in the order R 0 , G 0 , B 0 , ... R n , G n , B n , with
n = HthumbnailC * VthumbnailC. | + +NOTE – The format of the thumbnail described in this clause is the same as the format of the thumbnail optionally carried in the JFIF marker segment and described in 10.1. + +## Bibliography + +(This annex does not form an integral part of this Recommendation | International Standard.) + +- [1] JPEG File Interchange Format specification v1.02, informal publication edited by Eric Hamilton of C-Cube Microsystems, 1 September, 1992. + +- [2] IEC 61966-2-1:1999/Amd.1:2003, *Multimedia systems and equipment – Colour measurement and management – Part 2-1: Colour management – Default RGB colour space – sRGB – Amendment 1: sYCC and bg-sYCC*. +- [3] ISO 15076-1:2005, *Image technology colour management – Architecture, profile format and data structure – Part 1: Based on ICC.1:2004-10*. +- [4] ISO 646:1991, *Information technology – ISO 7-bit coded character set for information interchange*. +- [5] Recommendation ITU-T T.50 (1992), *International Reference Alphabet (IRA) (Formerly International Alphabet No. 5 or IA5) – Information technology – 7-bit coded character set for information interchange*. + + + + + +## SERIES OF ITU-T RECOMMENDATIONS + +| | | +|-----------------|---------------------------------------------------------------------------------------------| +| Series A | Organization of the work of ITU-T | +| Series D | General tariff principles | +| Series E | Overall network operation, telephone service, service operation and human factors | +| Series F | Non-telephone telecommunication services | +| Series G | Transmission systems and media, digital systems and networks | +| Series H | Audiovisual and multimedia systems | +| Series I | Integrated services digital network | +| Series J | Cable networks and transmission of television, sound programme and other multimedia signals | +| Series K | Protection against interference | +| Series L | Construction, installation and protection of cables and other elements of outside plant | +| Series M | Telecommunication management, including TMN and network maintenance | +| Series N | Maintenance: international sound programme and television transmission circuits | +| Series O | Specifications of measuring equipment | +| Series P | Terminals and subjective and objective assessment methods | +| Series Q | Switching and signalling | +| Series R | Telegraph transmission | +| Series S | Telegraph services terminal equipment | +| Series T | Terminals for telematic services | +| Series U | Telegraph switching | +| Series V | Data communication over the telephone network | +| Series X | Data networks, open system communications and security | +| Series Y | Global information infrastructure, Internet protocol aspects and next-generation networks | +| Series Z | Languages and general software aspects for telecommunication systems | \ No newline at end of file diff --git a/marked/T/T-REC-T.90-199202-I_PDF-E/raw.md b/marked/T/T-REC-T.90-199202-I_PDF-E/raw.md new file mode 100644 index 0000000000000000000000000000000000000000..eed1e2db28613f9301e9903dbda4979acda6ac1c --- /dev/null +++ b/marked/T/T-REC-T.90-199202-I_PDF-E/raw.md @@ -0,0 +1,2499 @@ + + +![ITU logo: a globe with the letters ITU inside.](2dfa6ac3edfe874f68aa0cbccaa42322_img.jpg) + +ITU logo: a globe with the letters ITU inside. + +INTERNATIONAL TELECOMMUNICATION UNION + +# CCITT + +# T.90 + +THE INTERNATIONAL +TELEGRAPH AND TELEPHONE +CONSULTATIVE COMMITTEE + +**TERMINAL EQUIPMENT AND PROTOCOLS +FOR TELEMATIC SERVICES** + +--- + +**CHARACTERISTICS AND PROTOCOLS +FOR TERMINALS FOR TELEMATIC +SERVICES IN ISDN** + +**Recommendation T.90** + +--- + +![CCITT logo: a globe with the letters CCITT inside.](6ed175c791b5e156d9c98a8dbcc3318c_img.jpg) + +CCITT logo: a globe with the letters CCITT inside. + +Geneva, 1992 + +# FOREWORD + +The CCITT (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union (ITU). CCITT is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. + +The Plenary Assembly of CCITT which meets every four years, establishes the topics for study and approves Recommendations prepared by its Study Groups. The approval of Recommendations by the members of CCITT between Plenary Assemblies is covered by the procedure laid down in CCITT Resolution No. 2 (Melbourne, 1988). + +Recommendation T.90 was prepared by Study Group VIII and was approved under the Resolution No. 2 procedure on the 25th of February 1992. + +# --- CCITT NOTES + +- 1) In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication Administration and a recognized private operating agency. +- 2) A list of abbreviations used in this Recommendation can be found in Appendix VII. + +# **CHARACTERISTICS AND PROTOCOLS FOR TERMINALS FOR TELEMATIC SERVICES IN ISDN** + +*(revised 1991)* + +# **Summary** + +This Recommendation defines the functional profile for base standards ISO/IEC 7776, 8208 and 8885 to provide the lower layers of the telematic services protocol stack when operating on the ISDN. + +Parameter values are recommended to ensure good throughput when operating via long delay connections such as satellite routes. Backward compatibility with the *Blue Book* version has been maintained. + +Three methods of negotiating the lower layer parameter values have been included to satisfy various connection scenarios, e.g. completely within the ISDN or between the ISDN and other digital networks. + +This Recommendation supplies the network layer definition in Recommendation T.70 for telematic terminals but not the transport layer definition which is still retained as the telematic transport layer definition. + +# **CONTENTS** + +- 1 *Scope* + - 1.1 General + - 1.2 Use of bearer capabilities + - 1.3 Protocol architecture +- 2 *ISDN B-channel circuit-switched mode (DTE-DTE communication)* + - 2.1 Protocol set + - 2.2 Application rules +- 3 *ISDN B-channel packet-switched mode (DTE-DCE communication)* + - 3.1 Protocol set + - 3.2 Application rules +- 4 *Support of the OSI-network service* + - 4.1 Rationale for considering the OSI-NS + - 4.2 CCITT Recommendations and ISO standards + - 4.3 Requirements for the OSI-NS +- 5 *Additional X.25 optional user facilities* + - 5.1 Categories of additional functions + - 5.2 Functions + +6     *Interactions between the D-channel and B-channel* + +7     *Supplementary services* + +8     *Terminal response time* + +9     *Synchronization* + +10    *Higher layer protocols* + +10.1   Group 4 facsimile + +10.2   Teletex + +10.3   Videotex + +*Annex A*   – Procedures for connection establishment, connection release and information transfer + +*Annex B*   – ISDN D-channel packet-switched mode (DTE-DCE communication) + +*Annex C*   – Procedures for B-channel negotiation of layer 2 parameters for telematic terminals + +*Annex D*   – SDL diagram for link set up for SABM/SABME procedures + +*Annex E*   – SDL diagram for link set up to a T.90 compatible terminal for XID procedure + +*Appendix I*   – Facsimile terminals in the ISDN + +*Appendix II*   – Optional usage of the T.70 NL protocol + +*Appendix III*   – Service definitions and state transition diagrams for the data link layer within the B-channel (CS mode) + +*Appendix IV*   – Possible model for telematic endsystems taking into account the D-channel/B-channel coordination function + +*Appendix V*   – Rate adaptation function + +*Appendix VI*   – Recommended combinations of parameter values to ensure optimum throughput + +*Appendix VII*   – Alphabetical list of abbreviations. + +# 1 Scope + +## 1.1 General + +The Integrated services digital network (ISDN) supports a wide range of voice and non-voice services and applications in the same network via a multipurpose user-network interface. + +This Recommendation describes the requirements for telematic terminals, developed for ISDN application, and connected to an ISDN via an I-Series interface. + +For example, teletex (defined in Recommendation T.60), group 4 facsimile (defined in Recommendation T.563) and videotex [defined in draft Recommendations T.102 and T.103 (see Note)]. + +*Note* – Draft Recommendations T.102 and T.103 are currently under study and not yet available. + +Telematic terminals supporting both teletex and group 4 facsimile in mixed mode of operation (defined in Recommendation T.561) are also covered by this Recommendation. + +Terminal requirements to support other telematic services are for further study. + +Terminals developed for the provision of telematic services in circuit switched public data networks (CSPDNs), packet switched public data networks (PSPDNs) and public switched telephone networks (PSTNs), using terminal adaptors to access the ISDN are not covered by this Recommendation (see Note 1). + +Interworking with existing telematic terminals connected to CSPDNs, PSPDNs and PSTNs, thereby maintaining the telematic service integrity, should be possible, but is outside the scope of this Recommendation (see Note 2). + +This Recommendation includes several negotiation mechanisms for selection of optional parameters. + +*Note 1* – For implementation guideline, consideration of incoming calls and information elements for facsimile terminals are described in Appendix I. + +*Note 2* – For rate adaptation function, see Appendix V. + +## 1.2 Use of bearer capabilities + +This Recommendation is based on the use of bearer capabilities defined for the ISDN, using B-channels for the information transfer and virtual circuit connection control and the D-channel for the connection control. + +The use of both circuit-switched and packet-switched information transfer modes is defined. + +The use of the frame mode information transfer as defined in Recommendation I.122, is for further study. + +## 1.3 Protocol architecture + +This Recommendation provides the application rules for other CCITT Recommendations and ISO standards aiming at end-to-end (DTE-DTE) communication through the network as well as DTE-DCE interconnection and support of OSI-network service. + +The use of existing protocols for ISDN telematic terminals different from those described in §§ 2 and 3 is optional. In the case of § 2, the use of T.70 CSPDN minimum header is an additional option. + +# 2 ISDN B-channel circuit-switched mode (DTE-DTE communication) + +For this mode the circuit-switched 64 kbit/s unrestricted information transfer capability shall be used. + +For additional information regarding connection control phase, see § A.1 a). + +For additional information regarding the information transfer phase, see § A.1 b). + +## 2.1 Protocol set + +The protocol set applicable to the ISDN B-channel circuit-switched mode (CS mode) is shown in Figure 1/T.90. + +![](1be8e9cad5f38fa47bdb81e549a3bec9_img.jpg) + +| OSI layer | Physical connection control | Virtual connection control and information transfer | +|-----------|--------------------------------------------------------------------------------------------------------|-----------------------------------------------------| +| 3 | Q.931 | ISO/CEI 8208 (Note 3) | +| 2 | Q.921 (LAPD) | ISO/CEI 7776
DTE/DTE operation (Note 2) | +| 1 |
< D-channel >
< B-channel >
I.430/I.431 (Note 1)
| | + +T0805701-91 + +*Note 1* – See § 2.2.1. + +*Note 2* – Full-duplex single link procedures are defined as described in § 2.2.3. For service definitions and state transition diagrams for the data link layer within the B-channel, see Appendix III. + +*Note 3* – DTE-DTE connection is specified on the basis of ISO/IEC 8208 (March 1990) as described in § 2.2.5. In case of the completion of LLC negotiation, the T.70 NL protocol (CSPDN minimum header, Recommendation T.70, § 3.3) may optionally be supported in addition to the ISO/CEI 8208 and used on a per-call-basis. In case of the failure or the absence of LLC negotiation, ISO/CEI 8208 protocol shall be used. For further information see Appendix II. + +FIGURE 1/T.90 + +## 2.2 Application rules + +### 2.2.1 Layer 1 – Physical layer interface characteristics + +The physical interface characteristics shall be in accordance with the I-Series Recommendations: I.430 (Basic user-network interface, layer 1 specifications), I.431 (Primary rate user-network interface, layer 1 specifications). This layer provides full duplex transmission capability. + +### 2.2.2 Layer 2 – D-channel connection control phase + +Recommendation Q.921 shall apply. + +### 2.2.3 Layer 2 – B-channel link layer procedure + +The link layer procedure shall consist of a fully symmetrical HDLC procedure as defined in ISO/IEC 7776 for DTE-DTE operation compatible with Recommendation X.75 modified by the application rules defined in § 2.2.3.2.2. + +#### 2.2.3.1 Address procedure + +The following describes the application of the link addressing procedures of Recommendation X.75. Link addresses (A and B) shall be assigned dynamically on a per-call-basis according to the following rules: + +- a) the calling terminal shall take address A; +- b) the called terminal shall take address B; +- c) commands and responses shall be transferred as shown in Figure 2/T.90; +- d) A and B addresses are coded as follows (Note): + +| Address | bit | | | | | | | | +|---------|-----|---|---|---|---|---|---|---| +| | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | +| A | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | +| B | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | + +*Note* – The terminal will discard all frames received with an address other than A and B. + +![Sequence diagram showing communication between Calling terminal A and Called terminal B. The diagram illustrates four frames: 'Commands (B)' from A to B, 'Responses (B)' from B to A, 'Commands (A)' from B to A, and 'Responses (A)' from A to B.](1c953f32bd34345dfd68fddf8a3736d6_img.jpg) + +``` +sequenceDiagram + participant A as Calling terminal A + participant B as Called terminal B + A->>B: Commands (B) + B-->A: Responses (B) + B-->A: Commands (A) + A-->B: Responses (A) +``` + +Sequence diagram showing communication between Calling terminal A and Called terminal B. The diagram illustrates four frames: 'Commands (B)' from A to B, 'Responses (B)' from B to A, 'Commands (A)' from B to A, and 'Responses (A)' from A to B. + +T0805710-90 + +FIGURE 2/T.90 + +#### 2.2.3.2 *Implementation rules* + +In order to achieve full compatibility between different implementations, the rules in this section for the implementation of Recommendation X.75 shall be followed. + +##### 2.2.3.2.1 *General rules* + +- a) The 1988 version (*Blue Book*) of CCITT Recommendation X.75, § 2 shall be used as the reference specification. +- b) The term “STE” shall be read as “DTE”. +- c) At present the non-extended mode of operation (i.e. modulo 8) and the extended mode of operation (i.e. modulo 128) are defined. For the purpose of this Recommendation, support for modulo 8 is mandatory and modulo 128 is optional. The terminal supporting the extended mode shall also support the non-extended mode. It is strongly recommended that the extended mode of operation (i.e. modulo 128) be supported. + +The evolution towards LAPD (modulo 128 only) in layer 2 of the B-channel is expected to lead to the use of modulo 128 as the common base modulo in the long term. + +- d) To facilitate interworking between terminal equipments using modulo 8 and modulo 128, negotiation mechanisms specified in this Recommendation shall be used. Layer 2 parameters such as modulo and *k* parameter may be negotiated out-of-band using the LLC-IE. + +In case of failure or absence of out-of-band negotiation, XID and/or SABM/SABME procedures may optionally be used. The XID and SABM/SABME procedures are specified in Annexes C and D respectively. Annex E provides SDL description for negotiation mechanisms between the XID and SABM/SABME procedures. + +- e) Only the single link procedure (SLP) shall be used. + +##### 2.2.3.2.2 *Specific application rules* + +The following rules refer to the indicated sections and tables of Recommendation X.75. For the application of the non-extended and extended mode see § 2.2.3.2.1 c) and d). + +| | | | +|----|------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| +| a) | Table 1/X.75
(non-extended mode)
Table 2/X.75
(extended mode) | I-frames should not be sent with an empty I field.
Non-extended mode $N \geq 0$ and $N \leq N1-32$ .
Extended mode $N \geq 0$ and $N \leq N1-40$ .
Received empty I-frames shall be treated as valid I-frames. | +| b) | § 2.3.4.9 | Items 5), 6) and 7) are not valid (shall not result in the sending of an FRMR).
Instead the following actions shall be implemented:
– not expected supervisory frames with the F-bit set to 1 shall be ignored;
– not expected UA or DM response shall be ignored;
– frames with an invalid N(S) shall be responded to by sending REJ (see § 2.3.5.2.1 of Recommendation X.75).
Frames with a FRMR control field shall not be responded by sending a FRMR. | +| c) | Table 7/X.25
(non-extended mode)
Table 8/X.75
(extended mode) | Bits W, X, Y and Z set to 0 indicate that no reason for frame rejection is given. | +| d) | § 2.3.5.3 | The DTE and the ISDN are not octet aligned and the last paragraph is therefore valid. | +| e) | § 2.3.5.5 | Higher layers should be notified when timer T3 expires (excessive idle state). | +| f) | § 2.4.3 | Related to the first paragraph, read instead of “next response” “corresponding response”. | +| g) | § 2.4.4.1 | In the active channel state, the DTE shall transmit contiguous flags independent of the other DTE.
The calling DTE shall initiate the link by sending a SABM (non-extended mode) or a SABME (extended mode) command with the P-bit set to 1. | +| h) | § 2.4.4.4.1 | A condition for entering the disconnected phase is also that no unacknowledged DISC command exists, because of collision cases (refer to Recommendation X.75, § 2.4.4.5).
In the disconnected phase, it is the calling DTE which shall initiate link set-up. | +| i) | § 2.4.5.9
4 th paragraph | If a RNR is received, the DTE shall remain in the time recovery condition (because the other DTE is still in the busy condition). | +| j) | § 2.4.5.9
5 th paragraph | If a RNR is received, the DTE shall not resume I-frame transmission or retransmission. | +| k) | § 2.4.5.9
last paragraph | If the transmission attempt variable is equal to N2, the DTE shall enter the disconnected phase. | +| l) | § 2.4.7.3 | In the frame rejection condition, the DTE shall only check the commands and react with a FRMR according to the P-bit.
The frame rejection is cleared when the DTE receives a SABM (non-extended mode) or a SABME (extended mode), or, receives or transmits a DISC command. | +| m) | § 2.4.7.3
2 nd paragraph | Only the DTE which caused the FRMR condition may try to reset the link. | +| n) | § 2.4.7.3
3 rd paragraph
(see Note 1) | After N2 attempts to get the other DTE to reset the link, the DTE shall enter the disconnected phase. | +| o) | § 2.4.8.1
(see Note 2) | The timer T1 shall be started at the end of frame transmission. The value of T1 depends on the data signalling rate, the frame length, the value of N2, and a fixed time representing both T2 and the transmission delay [see item r)].
A value is recommended between 2.5 and 7 seconds. Consideration of a specific value requires further study. | +| p) | § 2.4.8.2
(see Note 2) | $T1 > T2$ ,
$T2 < 1$ second. | +| q) | § 2.4.8.3
2 nd paragraph | $T3 \leq 60$ seconds,
$T3 \geq 30$ seconds. | +| r) | § 2.4.8.4 | $N2 \geq 60 \text{ seconds} + T1$ . | +| s) | § 2.4.8.5 | In case of layer 3, modulo = 8,
non-extended mode $N1 = 16\,440$ bits;
extended mode $N1 = 16\,448$ bits.

In case of layer 3, modulo = 128,
non-extended mode $N1 = 16\,448$ bits;
extended mode $N1 = 16\,456$ bits. | +| t) | § 2.4.8.6
(see Note 2) | Non-extended mode $k \leq 7$ (default value $k = 7$ )
Extended mode $k \leq 127$ (default value $k = 80$ ). | + +*Note 1* – It is not meaningful to reset the link if the other DTE has not responded for $N2 \times T1$ . + +*Note 2* – The acknowledgement strategy used by the receiving DTE should be independent of any knowledge about the value of $k$ used by the sending DTE. This can be achieved by acknowledging every correctly received I-frame as soon as possible. + +### 2.2.4 *Layer 3 – D-channel connection control phase* + +Recommendation Q.931 shall apply. All encodings should be derived from the relevant section in Recommendation Q.931. + +Three information elements (IEs) are of particular interest to terminals accessing telematic services. See Annexes B and L of Recommendation Q.931 for further information. + +- Bearer capability (BC) information element. The BC IE is used to carry information of interest to the bearer service providing network. The BC IE is required to be generated by the calling side, and shall be examined by the called side. +- Low layer compatibility (LLC) information element. The LLC IE is used to carry information about protocols at and below the network layer of interest only to the two endsystems and interworking functions (IWFs). The LLC IE shall be generated by the calling side, and shall be examined, if present, by the called side. LLC IEs may be used for negotiation of layer 2 and layer 3 parameters. +- High layer compatibility (HLC) information element. The HLC IE is used to carry information between the endsystems related to protocols above the network layer. The HLC IE shall be generated by the calling side, and shall be examined, if present, by the called side. + +Fields in bearer capability (BC), low layer compatibility (LLC), and high layer compatibility (HLC) information elements (IE) to be conveyed at the S/T reference point of the user-network interface during the call establishment phase, shall be set to the following values. + +*Note* – For the coding of BC IE in case of rate adaptation function, see Appendix V. + +#### 2.2.4.1 *Bearer capability (BC)* + +- a) Mandatory fields, to be set to the fixed values (the value to be set is given in parentheses following each field description, see Recommendation Q.931): + - coding standard – octet 3 (CCITT standardized coding); + - information transfer capability – octet 3 (unrestricted digital information, see Note); + - transfer mode – octet 4 (Circuit mode); + - information transfer rate – octet 4 (64 kbit/s). +- b) Fields not required in the default case but may be explicitly encoded: + - structure – octet 4a; + - configuration – octet 4a; + - establishment – octet 4a; + - symmetry – octet 4b. +- c) Fields to be omitted: + - all other fields. + +*Note* – The selection whether to use unrestricted or restricted information transfer capability is out of the scope of this Recommendation. + +#### 2.2.4.2 Low layer compatibility (LLC) + +The LLC IE shall be encoded as follows: + +- a) Fields to be set to fixed values (the value to be set is given in parentheses following each field description, see Recommendation Q.931): + - coding standard – octet 3 (CCITT standardized coding); + - information transfer capability – octet 3 (unrestricted digital information); + - LLC negotiation indicator – octet 3a, bit 7 (see Note 1); + - transfer mode – octet 4 (circuit mode); + - information transfer rate – octet 4 (64 kbit/s); + - user information layer 2 protocol – octet 6 (ISO/IEC 7776 DTE-DTE operation compatible with Recommendation X.75 modified by the application rules defined in § 2.2.3.2.2); + - user information layer 3 protocol – octet 7 (ISO/IEC 8208). +- b) Fields with variable content: + - the LLC IE may be transferred transparently by an ISDN between the called user and the calling user and may be used for parameter negotiation as described in Annex M to Recommendation Q.931; + - the calling user may use the optional extension octets 6a, 6b, 7a, 7b and 7c of the LLC IE as encoded in Figure 3/T.90 and Table 1/T.90 to indicate a set of preferred layer 2 and layer 3 parameters. The absence of an extension octet shall indicate the use of the default values of all parameters encoded by that octet. Multiple alternative sets of parameters may be specified by the concatenation of multiple LLC IEs in order of preference (see Note 2); + - Table 1/T.90 defines the codepoints for currently defined protocols and parameter values used by this Recommendation. Additional codepoints will be defined as and when alternate layer 2 and layer 3 protocols are defined. Suggested parameter values are given in Appendix VI. +- c) Fields to be omitted: + - all other fields. + +*Note 1* – When octet 3a is omitted, out-of-band negotiation is not possible. + +*Note 2* – Some networks may not transport multiple LLC IEs. It is recognized that this may limit the ability to negotiate multiple sets of parameters until networks support the transport of multiple LLC IEs. + +| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | | | | | | +|------------|----------------------|---|-------------------------------------------------------------------------|-------------|---|-------------------------------|---|-------------|--|--|--|--| +| 0/1
ext | 1 | 0 | 1 | 0 | 0 | 0 | 1 | Octets
6 | | | | | +| | Layer 2 ident. | | User information layer 2 protocol
(ISO/CEI 7776 – DTE-DTE operation) | | | | | | | | | | +| 0/1
ext | Mode | | 0 | 0 | 0 | 0 | 0 | 6a (Note 1) | | | | | +| | | | Spare | | | Q.933 use
(Q.933 not used) | | | | | | | +| 1
ext | Value of k parameter | | | | | | | 6b (Note 1) | | | | | +| 0/1
ext | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 7 | | | | | +| | Layer 3 ident. | | User information layer 3 protocol
(ISO/CEI 8208) | | | | | | | | | | +| 0/1
ext | Mode | | 0 | 0 | 0 | 0 | 0 | 7a (Note 2) | | | | | +| | | | Spare | | | | | | | | | | +| 0/1
ext | 0 | 0 | 0 | Packet size | | | | 7b (Note 2) | | | | | +| | Spare | | | | | | | | | | | | +| 1
ext | Packet window size | | | | | | | 7c (Note 2) | | | | | + +T0807230-91 + +*Note 1* – If octet 6b is present then octet 6a shall also be present. + +*Note 2* – If octet 7b is present then octet 7a shall also be present. If octet 7c is present then octets 7a and 7b shall also be present. +For values not fixed in this Figure, see Table 1/T.90. + +FIGURE 3/T.90 + +##### **Encoding of low layer compatibility information element** + +TABLE 1/T.90 + +##### **Encoding of low layer compatibility information element** + +##### *Mode of operation (octet 6a)* + +Bits + +7 6 + +| | | +|-----|---------------| +| 0 1 | Normal mode | +| 1 0 | Extended mode | + +All other values are reserved. + +##### *Q.933 use (octet 6a)* + +Bits + +2 1 + +| | | +|-----|---------------------------------------------------------------------| +| 0 0 | For use when the coding defined in Recommendation Q.933 is not used | +|-----|---------------------------------------------------------------------| + +##### *Value of k parameter (octet 6b)* + +Bits + +| | | +|-----|---------------------------| +| 7-1 | Binary encoded (1 to 127) | +|-----|---------------------------| + +##### *Mode of operation (octet 7a)* + +Bits + +7 6 + +| | | +|-----|------------------------------------| +| 0 1 | Normal packet sequence numbering | +| 1 0 | Extended packet sequence numbering | + +All other values are reserved. + +##### *Packet size (octet 7b)* + +Bits + +4 3 2 1 + +| | | +|---------|-------------| +| 0 1 1 1 | 128 octets | +| 1 0 0 0 | 256 octets | +| 1 0 0 1 | 512 octets | +| 1 0 1 0 | 1024 octets | +| 1 0 1 1 | 2048 octets | + +##### *Packet window size (octet 7c)* + +Bits + +| | | +|-----|---------------------------| +| 7-1 | Binary encoded (1 to 127) | +|-----|---------------------------| + +#### 2.2.4.3 High layer compatibility (HLC) + +The HLC IE shall be encoded as follows: + +- a) Fields to be set to fixed values (the value to be set is given in parentheses following each field description, see Recommendation Q.931): + - coding standard – octet 3 (CCITT standardized coding); + - interpretation – octet 3 (first high layer characteristics identification to be used in the call); + - presentation method of protocol profile – octet 3 (high layer protocol profile). +- b) Fields with variable content: + - high layer characteristics identification – octet 4 (e.g. facsimile group 4, teletex, videotex). + +To maximize the usefulness of HLC checking: + +- 1) the calling telematic terminal shall select the HLC element according to the type of document to be transferred; +- 2) the called terminal holds a list of HLC elements describing its receiving capabilities. It will accept an HLC element corresponding to any one of these. + +An example of such a scheme is illustrated in Table 2/T.90. + +TABLE 2/T.90 + +**Use of HLC codes by teletex and group 4 facsimile terminals** + +| Telematic service terminals | HLC codes | | +|-----------------------------|-----------------------------------------------------------|--------------------------------------------------| +| | Sent from calling terminals (Notes 2 and 3) | Accepted by receiving terminals (Note 4) | +| Basic teletex | Basic teletex | Basic teletex | +| Teletex mixed mode | Basic teletex
Mixed mode (Note 1) | Basic teletex
Mixed mode | +| Group 4 facsimile class 1 | Group 4 facsimile | Group 4 facsimile | +| Group 4 facsimile class 2 | Group 4 facsimile | Group 4 facsimile
Mixed mode
Basic teletex | +| Group 4 facsimile class 3 | Group 4 facsimile
Mixed mode
Basic teletex (Note 1) | Group 4 facsimile
Mixed mode
Basic teletex | + +*Note 1* – In case that the calling terminal is teletex mixed mode or group 4 facsimile class 3, only one element is to be sent depending on originating document type. + +*Note 2* – For multi-service telematic terminals sending more than one document in the same call, the HLC indicates functionality required for that call. + +*Note 3* – When the calling terminal only wishes to receive a document from a called terminal (polling), HLC IE indicates the preferred functionality of the calling terminals. + +*Note 4* – Appendix I provides additional information in order to cater for cases where calls for facsimile equipment are incoming from networks not able to convey HLC information. + +### 2.2.5 Layer 3 – B-channel virtual connection control and information transfer phase + +ISO/IEC 8208 (1990) shall apply. + +In particular, the following sections of ISO/IEC 8208 are referred: + +- § 3.3: Differences in DTE/DTE and DTE/DCE operation; +- § 3.4: Operating over circuit-switched connections; +- § 4.5: Determining “DTE” or “DCE” characteristics. + +In addition, the following points shall be noted when using this protocol: + +- a) calling DTE shall send a RESTART REQUEST packet, begin the restart procedure, and establish virtual circuits. See § 3.4 of ISO/IEC 8208; +- b) the qualifier bit in data packets shall always be set to “0” for teletex and group 4 facsimile and may be set to “0” or “1” for videotex; +- c) the delivery confirmation bits in all packets should be set to “0”; +- d) normal X.25 reset procedures shall apply; +- e) each control block or data block of the transport layer shall be carried in a complete data packet sequence; +- f) the terminal should not send a DTE REJECT packet; +- g) in case of group 4 facsimile and teletex, terminals shall use a specific protocol identifier within CALL REQUEST/INCOMING CALL packets. This identifier is represented by the first octet of the call user data field (the use of remaining octets is for further study) as shown below: + +| | | | | | | | | | +|-------|---|---|---|---|---|---|---|---| +| bit | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| octet | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | + +The protocol identifier for Videotex shall be as shown below, indicating the use of Recommendation X.29: + +| | | | | | | | | | +|-------|---|---|---|---|---|---|---|---| +| bit | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | +| octet | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | + +Other values are for further study; + +- h) out-of-band negotiation of layer 3 modulo may be performed through the use of the LLC information element; +- i) it is recommended that the value chosen for modulo for layer 3 shall be the same as the modulo for layer 2. + +#### 2.2.5.1 Layer 3 – Packet size and packet window size of out-of-band negotiation and in-band negotiation + +Out-of-band negotiation of layer 3 packet size may be performed through the use of the LLC information element. The rules for in-band packet size negotiation are given in § 15.2.2.1.1 of ISO/IEC 8208. The values for this Recommendation are restricted to 128, 256, 512, 1024 and 2048 octets. + +Out-of-band negotiation of layer 3 packet window size may be performed through the use of the LLC information element. The rules for in-band packet window size negotiation are given in § 15.2.2.1.2 of ISO/IEC 8208. + +The implementation of the flow control parameter negotiation for the packet size and the packet window size is mandatory. In the case when out-of-band negotiation is successful, the use of flow control parameter negotiation facility is optional. In the case of a failure of out-of-band negotiation, the calling terminal shall request the flow control parameter negotiation facility in order to use the recommended combination of parameter values for optimum communications efficiency and/or to maintain compatibility with the terminal based on the 1988 version of this Recommendation. + +In case of conflict between negotiated values out-of-band and in-band, the values negotiated later shall prevail. + +Default values for normal packet sequence numbering shall be packet size = 128 and packet window size = 2 (see Note). Default values for extended packet sequence numbering shall be packet size = 128 and packet window size = 80. + +*Note* – To optimize the efficiency of specific Telematic applications (in particular group 4 facsimile) the negotiation mechanism for packet window size and packet size should lead to other values than packet window size = 2 and packet size = 128. The recommended combinations of parameter values are given in Appendix VI. The segmentation and reassembly are not required. + +# 3 ISDN B-channel packet-switched mode (DTE-DCE communication) (see Note) + +*Note* – For ISDN D-channel packet-switched mode (DTE-DCE communication), see Annex B. + +## 3.1 Protocol set + +The protocol set applicable to the packet-switched mode (PS mode) is shown in Figure 4/T.90: + +![Figure 4/T.90: Protocol set diagram showing OSI layers 1, 2, and 3 for Access connection control and Virtual connection control and information transfer.](96b0240f56d14453b5da05ec30fd5c6e_img.jpg) + +The diagram illustrates the protocol set for ISDN B-channel packet-switched mode across three OSI layers. It is structured as a table with two main columns: 'Access connection control' and 'Virtual connection control and information transfer'. The rows represent OSI layers 1, 2, and 3. Layer 1 is divided into two channels: '< D-channel >' and '< B-channel >'. The protocols are as follows: + +| OSI layer | Access connection control | Virtual connection control and information transfer | +|-----------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------| +| 3 | Q.931 | X.25 PLP | +| 2 | Q.921 (LAPD) | X.25 LAPB | +| 1 |
< D-channel >
< B-channel >
I.430/I.431 (Note)
| | + +T0805721-91 + +*Note* – See § 2.2.1. + +Figure 4/T.90: Protocol set diagram showing OSI layers 1, 2, and 3 for Access connection control and Virtual connection control and information transfer. + +FIGURE 4/T.90 + +## 3.2 *Application rules* + +### 3.2.1 *Layer 1 – Physical layer interface characteristics* + +See § 2.2.1. + +### 3.2.2 *Layer 2 – Link layer procedure* + +Recommendation X.31 (case B) shall apply, so that the applied protocols are as follows: + +- connection control is to be achieved using Recommendation Q.921 in the D-channel; +- virtual connection control and information transfer is to be achieved using Recommendation X.25 LAPB in the B-channel. + +### 3.2.3 *Layer 3 – Network layer procedure* + +Recommendation X.31 (case B) shall apply, so that protocols to be applied and application rules are as follows: + +#### 3.2.3.1 *Connection control phase* + +Recommendation Q.931 and the packet layer protocol of Recommendation X.25 shall apply. + +Fields in the bearer capability (BC) information element (IE) to be conveyed at the S/T reference point of the user-network interface during the call establishment phase, shall be set to the values defined below. + +Recommendation Q.931 shall apply. All encodings should be derived from the relevant section in Recommendation Q.931. + +- Bearer capability (BC) information element – the BC IE is used to carry information of interest to the bearer service providing network. The BC IE is required to be generated by the calling side, and shall be examined by the called side. + +##### 3.2.3.1.1 *Bearer capability (BC)* + +- a) Mandatory fields, to be set to the fixed values (the value to be set is given in parentheses following each filed description, see Recommendation Q.931): + - coding standard – octet 3 (CCITT standardized coding); + - information transfer capability – octet 3 (unrestricted digital information, see Note); + - transfer mode – octet 4 (packet mode); + - user information layer 2 protocol – octet 6 (CCITT Recommendation X.25, link layer); + - user information layer 3 protocol – octet 7 (CCITT Recommendation X.25, packet layer). +- b) Fields not required in the default case but may be explicitly encoded: + - structure – octet 4a; + - configuration – octet 4a; + - establishment – octet 4a; + - symmetry – octet 4b. +- c) Fields to be omitted: + - all other fields. + +*Note* – The selection whether to use unrestricted or restricted information transfer capability is out of the scope of this Recommendation. + +The low layer compatibility information element (LLC) is not used in PS mode. The use of the LLC in future evolutions of the ISDN packet mode service is for further study. + +The high layer compatibility information element (HLC) is not used in PS mode. The use of the HLC in future evolutions of the ISDN packet mode service is for further study. + +#### 3.2.3.2 *Virtual connection control and information transfer phase* + +Recommendation X.25 packet layer protocol applies. Item b) and items d) through g) of the application rules specified in § 2.2.5, apply. + +# 4 **Support of the OSI-network service** + +## 4.1 *Rationale for considering the OSI-NS* + +The evolution and realization of the bearer services and teleservices in the ISDN environment and the recognized protocol base within the CCITT directs – as far as the network layer of the communication architecture is concerned – to the use of the OSI-NS. In order to lay the grounds for the integrity of the services under these conditions, the application rules for the network layer protocol (see Notes 1 and 2) need to be defined. + +*Note 1* – In the ISDN circuit-switched mode, support of the OSI-NS is provided entirely by the B-channel X.25 packet layer protocol, and is available once the ISDN call has been connected. The provision of the OSI-NS by other means is for further study. + +*Note 2* – In the case of videotex, the provision of the full OSI-NS is for further study. + +## 4.2 *CCITT Recommendations and ISO standards* + +The following CCITT Recommendations and ISO standards are used to provide the OSI-NS: + +- CCITT Recommendation X.213; +- ISO/IEC 8208; +- ISO/IEC 8878 and ISO/IEC 9574 + +The use of the D-channel (see Recommendation Q.931) or the relevant protocols defined for future packet oriented information transfer modes (see Recommendation I.122) for the provision of the OSI-NS, is for further study. + +## 4.3 *Requirements for the OSI-NS* + +To balance the expenditure for the development of telematic terminals under the consideration of the OSI-NS, the requirements are limited to the necessary minimum. + +This can be achieved by terminating, in the case of an incoming call for both the circuit switched (CS) and packet switched (PS) cases, the layer 3 protocol to provide the obligatory functions of the OSINS only. In the case of an outgoing call, calling terminals can initiate an OSI communication, as long as all the relevant facilities are supported. + +### 4.3.1 *Minimum requirements for the OSI-NS* + +Table 3/T.90 shows the list of the X.25 PLP optional user facilities which are proposed as a necessary minimum to support the OSI-NS. + +TABLE 3/T.90 + +#### **X.25 PLP optional user facilities** + +| Optional user facility
(Note 4) | | Used for support
of an incoming call
(Note 1) | Used
for support of
an outgoing call | +|------------------------------------|------------------------------------------------|-----------------------------------------------------|--------------------------------------------| +| 13.13
(Note 2) | Throughput class negotiation | Yes | Optional
(Note 3) | +| 13.16
(Note 2) | Fast select | Yes | Optional
(Note 3) | +| 13.27
(Note 2) | Transit delay selection and indication (TDSAI) | Yes | Optional
(Note 3) | +| 14.1
(Note 2) | Calling address extension | Yes | Optional
(Note 3) | +| 14.2
(Note 2) | Called address extension | Yes | Optional
(Note 3) | +| 14.3
(Note 2) | Minimum throughput class negotiation | Yes | Optional
(Note 3) | +| 14.4
(Note 2) | End-to-end transit delay negotiation (EETDN) | Yes | Optional
(Note 3) | +| 14.7
(Note 2) | Expedited data negotiation | Yes | Optional
(Note 3) | + +*Note 1* – To fulfill at least the minimum functionality of the OSI-NS (clarification found, if necessary in § 4.3.2). + +*Note 2* – Refers to the relevant section in ISO/IEC 8208. + +*Note 3* – May optionally be invoked for a telematic communication. These shall be supported if initiating a communication with an OSI terminal. + +*Note 4* – As the D-bit is always set to “0” in the circuit-mode case, the receipt confirmation selection requirement is satisfied for this case. + +### 4.3.2 *Minimum functionality when receiving a call from a system using the OSI-NS* + +The following text represents a possible way to achieve the minimum functionality when receiving a call from a system using the OSI-NS (refer to both ISO/IEC 8878 and ISO/IEC 8208): + +- 1) *Throughput class negotiation*: when replying to INCOMING CALL/CALL REQUEST, a throughput class facility request need not be made in the CALL ACCEPTED packet. If a throughput class facility request was not made in the CALL ACCEPTED packet, then this would mean that the throughput classes applying to the call would be those that have been indicated in the INCOMING CALL/CALL REQUEST packet. +- 2) *Fast select*: fast selection shall be supported for the full OSI-NS (full 128 octets of NS-user data available). The receipt of a CALL REQUEST packet which does not have the values “01” or “02” in the first octet of the call user data field would be considered an error [connection rejection – reason unspecified (permanent condition)]. Receipt of a CALL REQUEST packet which does have the value “02” indicates teletex and facsimile group 4 services operating according to Recommendation T.70 (layer 4 only). If the value “01” is received, this indicates videotex operating according to Recommendation X.29. + +- 3) *Transit delay selection and indication (TDSAI)*: this shall be accepted when received. However, if the reply to be coded in the “cumulative transit delay sub-field” of the EETDN facility is “unknown” (i.e. FF hexadecimal), then the value in the TDSAI field could be ignored. +- 4) *Calling and called address extension*: the use of OSI NSAP addressing is optional. + +The calling and the called terminal shall either insert an OSI NSAP address or set the address extension field length to zero. + +An incoming call shall not be cleared due to a missing OSI NSAP address. If an OSI NSAP address is received, the terminal shall check it and proceed as specified in ISO/IEC 8878 and ISO/IEC 9574. +- 5) *Minimum throughput class negotiation*: if a terminal reacts to the appearance of a throughput class facility request in the INCOMING CALL packet by not sending a throughput class facility request in the CALL ACCEPTED packet, then the minimum throughput class negotiation facility could be ignored. +- 6) *End-to-end transit delay negotiation (EETDN)*: when replying, this could contain the value “unknown” (i.e. FF hexadecimal). +- 7) *Expedited data negotiation*: this is used to negotiate the nonuse of expedited data (shall be used in the CALL ACCEPTED packet). + +# 5 Additional X.25 optional user facilities + +In addition to the facilities mentioned in § 4 that should be supported by telematic terminals in order to comply with the OSI-NS, additional facilities/functionalities shall be supported as a consequence of: + +- the use of X.25 PLP for the provision of the OSI-NS (this protocol allows layer 3 multiplexing and flow control); +- the provision of various X.25 originated user facilities; +- the provision of various service oriented user facilities by some networks (i.e. additional facilities) or by all networks (i.e. essential facilities) as defined by Recommendation X.2. + +There is no need for the provision of the additional service oriented user facilities in the circuit-switched case. The X.25 originated user facilities may be used in the circuit-switched case. + +## 5.1 Categories of additional functions (see Note) + +- X.25 originated user facilities + - 13.1 On-line facility registration + - 13.12 Flow control parameter negotiation +- Service oriented user facilities (network based) + - 13.14 Closed User Groups (CUG) selection + - 13.14 CUG with outgoing access selection + - 13.18 Reverse charging + - 13.21 Network user identification + - 13.22 Charging information + - 13.23 Recognized private operating agency (RPOA) selection + - 13.25 Call redirection notification + - 13.26 Called line address modified notification + +*Note* – D-bit modification is not supported. + +## 5.2 *Functions* + +### 5.2.1 *X.25 originated user facilities* + +#### 1) *On-line facility registration* + +The use of this facility shall be restricted to the modification of the range of logical channels. For the default values, Telematic terminals support a single two-way logical channel (i.e. LTC=HTC=1, LIC=HIC=0, LOC=HOC=0). + +#### 2) *Flow control parameter negotiation* + +The support of this facility is mandatory. Packet size and packet window size parameters may be negotiated (see Note). + +When the parameter negotiation is indicated in an INCOMING CALL packet, they shall respond properly in the CALL ACCEPTED packet. + +*Note* – Transport protocol data units (TPDUs) should be contained in single packets/frames to avoid segmentation (e.g. if TPDU is equal to 2048 octets, then packets/frames must be greater than 2048 octets). + +### 5.2.2 *Service oriented user facilities (network based)* + +#### 1) *Closed User Group selection* (essential in Recommendation X.2) *and CUG with outgoing access selection* (additional in Recommendation X.2) (13.14) + +These facilities may optionally be requested from telematic terminals (i.e. outgoing call only). CUG information received in an INCOMING CALL packet may be ignored. + +#### 2) *Reverse charging* (13.18) + +This facility may be supported by the same networks, and applies on a per-call-basis. The possibility of requesting reverse charging in outgoing calls is optional for telematic terminals, but they shall be able to properly handle and respond to the incoming call at the called side. + +(As a default, calls should be rejected.) + +#### 3) *Network user identification* (13.21) + +This facility may be applied by networks on a per-call-basis, following subscription made by prior arrangement for the agreed period of time. + +#### 4) *Charging information* (13.22) + +This facility may be provided by some networks on a per-call-basis, following subscription made by prior arrangement for the agreed period of time. The information may be handled or processed normally. + +As a minimum requirement, it may be ignored. + +#### 5) *RPOA selection* (13.23) + +This facility may be provided by some networks on a per-call-basis, following subscription made by prior arrangement for the agreed period of time. + +As a minimum requirement, it may be ignored. + +#### 6) *Call redirection notification* (13.25) + +This facility may be provided by some networks on a per-call-basis, without any particular user request. This information may be processed normally. + +As a minimum requirement, it may be ignored. + +#### 7) *Called line address modified notification* (13.26) + +This facility may be provided by some networks on a per-call-basis, without any particular user request. This information may be processed normally. + +As a minimum requirement, it may be ignored. + +# **6 Interactions between the D-channel and B-channel** + +Communication between the D-channel and B-channel is not synchronized in relation to each other by the ISDN and therefore information exchange via these channels can be accomplished independently and simultaneously. As a consequence of this, messages sent in the D-channel and B-channel in a distinct relationship to each other may be received in a different order. + +In order to achieve an orderly operation of the protocols in all telematic equipment, it is necessary to have an additional procedure to maintain the timing relationship. + +This model, architecture, and primitives of this additional procedure is left for further study. One possible approach is described in Appendix IV. + +# **7 Supplementary services** + +For application and description see Recommendations F.184, F.200, F.300, I.240-Series and I.250-Series (depending on the type of supplementary service). + +If the ISDN provides date/time information in the CONNECT message to the ISDN telematic terminal, this information shall take precedence over any other local available corresponding information (at least for call identification line). + +# **8 Terminal response time** + +For further study. + +# **9 Synchronization** + +The ISDN guarantees that the B-channel will be open for data traffic as soon as the CONNECT message has been received at the terminals. However, due to propagation delay the two CONNECT messages may not arrive at each terminal at the same time. + +Therefore the following procedure shall be used. + +The calling side and called side follow the sequence (see Note 3): + +- 1) the calling side and called side send “1”-bits until notified of B-channel establishment; +- 2) the called side sends CONNECT signal to the network when it activates the receiver circuit. The calling side activates the receiver circuit when CONNECT signal arrives from the network; +- 3) the calling side and called side send flags to the peer entity (see Note 1); +- 4) the calling side and called side start communication, i.e. the calling side sends SABM/SABME the called side (see Note 2) and the called side responds UA command to the calling side when SABM/SABME and arrives from the calling side. + +*Note 1* – If possible, the following sequence may be useful for reliable synchronization: + +- a) the calling side sends at least 64 concatenated flags aligned so that two adjacent “0”s occur between each string of “1”s until the first flag arrives from the called side and the called side sends at least 64 concatenated flags of the same type until SABM/SABME command arrives from the calling side; +- b) the calling side and called side consider the peer entity as active when the first flag arrives from the peer entity. + +*Note 2* – Flag detection before sending SABM/SABME may make more reliable synchronization. + +*Note 3* – Terminal adaptor connected by the existing telematic terminal should support the above sequence. + +The sequence diagram describing the operation of the calling side and called side is shown in Figure 5/T.90. + +![Sequence diagram showing the sequence of synchronization on layer 2 between Calling side, Network, and Called side. The diagram illustrates the exchange of D-channel and B-channel signals, including sequences of '1' bits, SABME, UA, and I (SETUP) through I (CONNECT ACKNOWLEDGE) (Note 2). It also shows the transition to 'Ready to communicate' via a 'SEQUENCE OF FLAGS' and the final SABM/SABME, UA, and I signals.](c914f51f4427bc672dd0526cfc90ebe9_img.jpg) + +The diagram illustrates the sequence of synchronization on layer 2 between the Calling side, Network, and Called side. The sequence of events is as follows: + +- Calling side:** + - Sends a **Sequence of "1" bits** (D-channel signal). + - Sends **SABME** (B-channel signal). + - Sends **UA** (B-channel signal). + - Sends **I (SETUP)** (B-channel signal). + - Sends **I (CALL PROCEEDING)** (B-channel signal). + - Sends **I (ALERTING)** (B-channel signal). + - Sends **I (CONNECT)** (B-channel signal). + - Sends **I (CONNECT ACKNOWLEDGE) (Note 2)** (B-channel signal). + - Sends **SEQUENCE OF FLAGS** (B-channel signal). + - Sends **SABM/SABME** (B-channel signal). + - Sends **UA** (B-channel signal). + - Sends **I** (B-channel signal). +- Network:** + - Transmits signals between the Calling side and the Called side. +- Called side:** + - Receives a **Sequence of "1" bits** (D-channel signal). + - Receives **UI (SETUP)** (B-channel signal). + - Sends **SABME** (B-channel signal). + - Sends **UA** (B-channel signal). + - Sends **I (ALERTING)** (B-channel signal). + - Sends **I (CONNECT)** (B-channel signal). + - Sends **I (CONNECT ACKNOWLEDGE)** (B-channel signal). + - Sends **SEQUENCE OF FLAGS** (B-channel signal). + - Sends **SABM/SABME** (B-channel signal). + - Sends **UA** (B-channel signal). + - Sends **I** (B-channel signal). + +**Call establishment and Ready to communicate:** + +- Call establishment:** Indicated by dashed arrows from the **I (CONNECT ACKNOWLEDGE)** signals on both sides. +- Ready to communicate:** Indicated by dashed arrows from the **SEQUENCE OF FLAGS** signals on both sides. + +**Note 1:** ———→ D-channel signals + =========> B-channel signals + +T0810870-92/d05 + +Sequence diagram showing the sequence of synchronization on layer 2 between Calling side, Network, and Called side. The diagram illustrates the exchange of D-channel and B-channel signals, including sequences of '1' bits, SABME, UA, and I (SETUP) through I (CONNECT ACKNOWLEDGE) (Note 2). It also shows the transition to 'Ready to communicate' via a 'SEQUENCE OF FLAGS' and the final SABM/SABME, UA, and I signals. + +Note 2 – The provision of the CONNECT ACKNOWLEDGE signal is optional. + +FIGURE 5/T.90 + +## The sequence of synchronization on layer 2 + +# 10 Higher layer protocols + +## 10.1 Group 4 facsimile + +See Recommendations F.184 (see Note), T.563 and T.561 including mixed-mode of operation. + +## 10.2 Teletex + +See Recommendations F.200 (see Note), T.60 and T.561 including mixed-mode of operation. + +*Note* – The rules given in § 5.3.2. of Recommendation T.70 regarding transport protocol data unit (TPDU) block length are adopted, in principle, but with the additional provision that the negotiation mechanism is mandatory (e.g. for more efficient communication via satellite links). + +## 10.3 Videotex + +The requirements for the videotex service are described in Recommendation F.300. The videotex coded information conforms to the data syntaxes defined in Recommendation T.101. The higher layer protocols to be used in the ISDN videotex are defined in draft Recommendation T.105 (based on Recommendation X.29). Additional communication requirements are defined in Recommendations T.102 and T.103. However, terminal characteristics and service/application functions of current systems are system provider dependent. + +# ANNEX A (to Recommendation T.90) + +## **Procedures for connection establishment, connection release and information transfer** + +Procedures shown below are not the requirements to the terminals for telematic services, but for reference only. + +## A.1 *ISDN circuit-switched mode* + +### a) *D-channel connection control phase* + +![Sequence diagram showing D-channel connection establishment and clearing between Calling DTE, Network, and Called DTE.](7e1c9b51e067a48cd0fcc9748d8bd8d8_img.jpg) + +``` + +sequenceDiagram + participant C as Calling DTE + participant N1 as Network + participant N2 as Network + participant D as Called DTE + + Note left of C: Call establishment using D-channel + C->>N1: SABME + N1->>C: UA + C->>N1: SETUP + N1-->>N2: + N2->>D: SABME + D->>N2: UA + N2->>N1: SETUP + N1->>C: CALL PROCEEDING + N2->>D: ALERTING + D->>N2: CONNECT + N2->>N1: CONNECT + N1->>C: CONNECT + C->>N1: CONNECT ACKNOWLEDGE + N1-->>N2: + N2->>D: CONNECT ACKNOWLEDGE + + Note center: (Data transfer phase) + + Note left of C: Call clearing using D-channel + C->>N1: DISCONNECT + N1->>C: RELEASE + C->>N1: RELEASE COMPLETE + N1-->>N2: + N2->>D: DISCONNECT + D->>N2: RELEASE + N2->>N1: RELEASE COMPLETE + +``` + +The diagram illustrates the D-channel connection control phase in ISDN circuit-switched mode. It is divided into two main sections: 'Call establishment using D-channel' and 'Call clearing using D-channel', separated by a dashed line labeled '(Data transfer phase)'. The participants involved are the Calling DTE, the Network (represented by two vertical lines), and the Called DTE. In the establishment phase, the Calling DTE sends SABME to the Network, which responds with UA. Then, SETUP is sent from the Calling DTE to the Network. The Network then forwards SABME to the Called DTE, which responds with UA. The Network then forwards SETUP to the Calling DTE, which responds with CALL PROCEEDING. The Network then forwards ALERTING to the Called DTE, which responds with CONNECT. The Network then forwards CONNECT to the Calling DTE, which responds with CONNECT ACKNOWLEDGE. The Network then forwards CONNECT ACKNOWLEDGE to the Called DTE. In the clearing phase, the Calling DTE sends DISCONNECT to the Network, which responds with RELEASE. The Calling DTE then sends RELEASE COMPLETE to the Network. The Network then forwards DISCONNECT to the Called DTE, which responds with RELEASE. Finally, the Network forwards RELEASE COMPLETE to the Called DTE. + +Sequence diagram showing D-channel connection establishment and clearing between Calling DTE, Network, and Called DTE. + +T0810880-92/d06 + +*Note 1* – This example shows the procedure in the case where the configuration is point-to-point, and the layer 2 link has not been established. Some signals can be omitted in this situation. + +*Note 2* – SABME and UA are specified by Recommendation Q.921 (layer 2). All others are specified by Recommendation Q.931 (layer 3). + +FIGURE A-1/T.90 + +### b) *B-channel virtual connection control and information transfer phase* + +![Sequence diagram showing the B-channel virtual connection control and information transfer phase between Calling DTE, Network, and Called DTE.](a74294f34a0c736b7ee0f5f0cdca7e28_img.jpg) + +The diagram illustrates the sequence of messages for the B-channel virtual connection control and information transfer phase. The participants are Calling DTE, Network, and Called DTE. The messages are as follows: + +- Calling DTE to Network: SABM/SABME +- Network to Called DTE: UA +- Called DTE to Network: I (X.25 RESTART REQUEST) +- Network to Calling DTE: I (X.25 RESTART CONFIRMATION) +- Calling DTE to Network: I (X.25 CALL REQUEST) +- Network to Called DTE: I (X.25 CALL CONNECTED) +- Called DTE to Network: I (X.25 DATA) +- Network to Calling DTE: I (X.25 DATA) +- Called DTE to Network: I (X.25 DATA) +- Network to Calling DTE: I (X.25 DATA) +- Called DTE to Network: I (X.25 CLEAR REQUEST) +- Network to Calling DTE: I (X.25 CLEAR CONFIRMATION) +- Calling DTE to Network: DISC +- Network to Called DTE: UA + +Data transfer using B-channel is indicated between the first and last messages. + +T0810890-92/d07 + +Sequence diagram showing the B-channel virtual connection control and information transfer phase between Calling DTE, Network, and Called DTE. + +*Note* – SABM/SABME, DISC and UA are specified by Recommendation X.75 (layer 2). +All others are specified by Recommendation X.25 PLP (layer 3). + +FIGURE A-2/T.90 + +## A.2 *ISDN B-channel packet-switched mode* + +See relevant signal procedures described in Recommendation X.31. + +# ANNEX B (to Recommendation T.90) + +## **ISDN D-channel packet-switched mode (DTE-DCE communication)** + +## **B.1**     *Protocol set* + +The protocol set applicable to the packet-switched mode (PS mode) is shown in Figure B-1/T.90: + +![Figure B-1/T.90: OSI Layer diagram for ISDN D-channel packet-switched mode. The diagram shows three layers: Layer 3 (Access connection control: Q.931, Virtual connection control and information transfer: X.25 PLP), Layer 2 (Q.921 (LAPD)), and Layer 1 (). A bracket under Layer 1 points to I.430/I.431 (Note).](58f4167687de8d7339594e5f6fbe0bc6_img.jpg) + +| OSI Layer | Access connection control | Virtual connection control and information transfer | +|-----------|---------------------------|-----------------------------------------------------| +| 3 | Q.931 | X.25 PLP | +| 2 | Q.921 (LAPD) | | +| 1 | | | + +I.430/I.431 (Note) + +Note – See § 2.2.1. T0805731-91 + +Figure B-1/T.90: OSI Layer diagram for ISDN D-channel packet-switched mode. The diagram shows three layers: Layer 3 (Access connection control: Q.931, Virtual connection control and information transfer: X.25 PLP), Layer 2 (Q.921 (LAPD)), and Layer 1 (). A bracket under Layer 1 points to I.430/I.431 (Note). + +FIGURE B-1/ T.90 + +## **B.2**     *Application rules* + +### **B.2.1**     *Layer 1 – Physical layer interface characteristics* + +See § 2.2.1. + +### **B.2.2**     *Layer 2 – Link layer procedure* + +Recommendation X.31 (case B) shall apply, so that the applied protocols are as follows: + +- connection control is to be achieved using Recommendation Q.921 on SAPI 0; +- virtual connection control and information transfer is to be achieved using Recommendation Q.921 on SAPI 16. + +### **B.2.3**     *Layer 3 – Network layer procedure* + +Recommendation X.31 (case B) shall apply, so that protocols to be applied and application rules are as follows: + +#### **B.2.3.1**     *Connection control phase* + +Recommendation Q.931 and the packet layer protocol (PLP) of Recommendation X.25 shall apply. + +Fields in the bearer capability (BC) information element (IE) to be conveyed at the S/T reference point of the user-network interface during the call establishment phase, shall be set to the values defined below. + +Recommendation Q.931 shall apply. All encodings should be derived from the relevant section in Recommendation Q.931. + +- *Bearer capability (BC) information element* – The BC IE is used to carry information of interest to the bearer service providing network. The BC IE is not required to be generated by the calling side. However, when an incoming call is offered to packet mode user equipment at user interface, the channel selection procedures described in the following BC IE shall be used. + +##### B.2.3.1.1 *Bearer capability (BC)* + +- a) When the channel indication information element indicates channel indication – No channel, exclusive, and D-channel indication – Yes, then mandatory fields should be encoded as follows (the value to be set is given in parentheses following each field description, see Recommendation Q.931): + - coding standard – octet 3 (CCITT standardized coding); + - information transfer capability – octet 3 (unrestricted digital information); + - transfer mode – octet 4 (packet mode); + - user information layer 2 protocol – octet 6 (CCITT Recommendation Q.921); + - user information layer 3 protocol – octet 7 (CCITT Recommendation X.25, packet layer). +- b) In all other cases, mandatory fields should be encoded as follows (the value to be set is given in parentheses following each field description, see Recommendation Q.931): + - coding standard – octet 3 (CCITT standardized coding); + - information transfer capability – octet 3 (unrestricted digital information); + - transfer mode – octet 4 (packet mode); + - user information layer 2 protocol – octet 6 (CCITT Recommendation X.25, link layer); + - user information layer 3 protocol – octet 7 (CCITT Recommendation X.25, packet layer). +- c) Fields not required in the default case but may be explicitly encoded: + - structure – octet 4a; + - configuration – octet 4a; + - establishment – octet 4a; + - symmetry – octet 4b. +- d) Fields to be omitted: + - all other fields. + +The low layer compatibility (LLC) information element is not used in PS mode. The use of the LLC in future evolutions of the ISDN packet mode services is for further study. + +The high layer compatibility (HLC) information element is not used in PS mode. The use of the HLC in future evolutions of the ISDN packet mode service is for further study. + +#### B.2.3.2 *Virtual connection control and information transfer phase* + +Recommendation X.25 packet layer protocol applies. Item b) and Items d) through g) of the application rules specified in § 2.2.5, apply. + +# ANNEX C (to Recommendation T.90) + +## **Procedures for B-channel negotiation of layer 2 parameters for telematic terminals** + +## **C.1**   *Introduction* + +This annex outlines XID procedures for negotiation of layer 2 parameters modulo and k parameter. This annex makes use of elements for the ISO-standardized high-level data link control procedures (HDLC), as realized in CCITT Recommendations Q.920/Q.921 (LAPD). One of these elements is the exchange identification (XID) frame used for exchanging data link information. The data link information to be exchanged is carried in the information field of the XID frame as explained in ISO 8885 (Note 1) and in this annex. Further discussion on XID is found in § C.2 and C.3. + +The procedures outlined in this annex can be used for negotiation of layer 2 parameters (i.e. modulo and k parameter) when LLC procedures are not supported by an ISDN to which the calling and/or the called telematic terminals are connected. In addition, these procedures can be used when the calling and/or the called terminal does not support the LLC procedures. These procedures can also be used if the transit network (if any) does not support the LLC procedures. + +*Note 1* – ISO 8885 – Information processing systems – Data communication – High-level data link control procedures – General purpose XID frame information field content and format, 1987. + +*Note 2* – This Recommendation does not preclude the use of other elements discussed in ISO 8885. + +## **C.2**   *General* + +The XID frame can be used to exchange data link information between the calling and the called telematic terminal. Data link information includes any and all essential characteristics, such as identification, authentication, and/or selection of optional functions concerning each terminal, such as parameter values. + +ISO 8885 also describes the content of the information field of the XID frame when it is encoded according to the “general purpose” format identifier. + +### **C.2.1**   *XID command/response frame* + +Figure C-1/T.90 shows the XID frame, as standardized in ISO 8885. The XID Frame is identified by the specific encoding of the control field as shown. + +![Diagram of the XID command/response frame structure showing fields F, A, C, XID Information field, FCS, and F. The Control field (C) is expanded to show bit values 1 1 1 1 P/F 1 0 1.](49a49278cad196bdfe0db6b4dd1be7fd_img.jpg) + +| | | | | | | +|---|---|---|-----------------------|-----|---| +| F | A | C | XID Information field | FCS | F | +|---|---|---|-----------------------|-----|---| + +T0805740-90 + +| | | | | | | | | +|---|---|---|---|-----|---|---|---| +| 1 | 1 | 1 | 1 | P/F | 1 | 0 | 1 | +|---|---|---|---|-----|---|---|---| + +F   Flag +A   Address field +C   Control field +FCS   Frame check sequence +P/F   Poll or final bit + +Diagram of the XID command/response frame structure showing fields F, A, C, XID Information field, FCS, and F. The Control field (C) is expanded to show bit values 1 1 1 1 P/F 1 0 1. + +FIGURE C-1/T.90 +**XID command/reponse frame** + +### C.2.2 *XID frame information field structure* + +The general structure of the information field of an XID frame, as standardized in ISO 8885, is shown in Figure C-2/T.90. The information field is composed of a number of sub-fields. These sub-fields are a format identifier sub-field, zero or more data link sub-fields, and possibly, a user data sub-field. + +![Diagram of XID frame and its sub-fields](dcb5711d118ae6753b0e12f86eda37db_img.jpg) + +The diagram illustrates the structure of an XID frame and its various sub-fields. At the top, a horizontal double-headed arrow labeled "XID frame" spans the entire width. Below it, a smaller horizontal double-headed arrow labeled "XID information field" spans the width of the information field. The main structure is a table with the following fields: + +| | | | | | | | | | +|------|---------|-------------------------|-----------------------------------|------------------------------------------------|-----|------------------------|-----|------| +| Flag | Address | Control
(1111P/F101) | Format
identifier
sub-field | Data link
layer
sub-field
(0 or more) | ... | User data
sub-field | FCS | Flag | +|------|---------|-------------------------|-----------------------------------|------------------------------------------------|-----|------------------------|-----|------| + +Below the "Data link layer sub-field" (0 or more) field, a horizontal double-headed arrow labeled "Data link layer sub-field" points to a table with three columns: + +| | | | +|--------------------------|----------------------|-----------------| +| Group identifier
(GI) | Group length
(GL) | Parameter field | +|--------------------------|----------------------|-----------------| + +Below the "Parameter field" column, a horizontal double-headed arrow labeled "Parameter field" points to a table with seven columns: + +| | | | | | | | +|------------------------------|--------------------------|-------------------------|-----|----|----|----| +| Parameter identifier
(PI) | Parameter length
(PL) | Parameter value
(PV) | ... | PI | PL | PV | +|------------------------------|--------------------------|-------------------------|-----|----|----|----| + +Below the "User data sub-field" field, a horizontal double-headed arrow labeled "User data sub-field" points to a table with two columns: + +| | | +|----------------------|-----------------| +| User data identifier | User data field | +|----------------------|-----------------| + +Diagram of XID frame and its sub-fields + +FCS Frame check sequence +P/F Poll or final bit + +T0805750-90 + +FIGURE C-2/T.90 +**XID frame and various sub-fields** + +#### C.2.2.1 *Format identifier sub-field* + +The format identifier (FI) sub-field is one octet in length and is the first octet of the information field of the XID frame. In general, the FI is encoded such that it can designate 128 different formats standardized by ISO and 128 different formats defined by users. Each ISO-standardized format is associated with a different FI value and is to be identified in ISO/IEC Standard 4335 (see Note). Two such formats have been defined at this time. The “general purpose” FI is the only FI that is discussed in ISO/IEC Standard 8885. + +*Note* – ISO 4335 – Information processing systems – Data communications – High-level data link control elements of procedures, 1987. + +#### C.2.2.2 *Data link layer sub-fields* + +Data link layer sub-fields are used to specify various data link layer characteristics, such as operational parameters. In terms of Figure C-2/T.90, a data link layer sub-field consists of a group identifier (GI) which is one octet in length, a group length (GL) which is two octets in length, and a parameter field (whose length is given by GL). The parameter field, in turn, is similarly decomposed into one or more sets of a parameter identifier, a parameter length, and a parameter value (the parameter length, however, is only one octet in length). + +*Note* – A group length value of zero indicates that there is no associated parameter field and that all parameters within the sub-field specified by the associated group identifier should assume their default values. + +Currently, there are three GIs standardized for data link layer sub-fields used with the “general purpose” FI. These are for parameter negotiation, address resolution and multilink parameter negotiation. For the purposes of this Recommendation, data link layer sub-fields associated with parameter negotiation shall be used. + +#### C.2.2.3 *User data sub-field* + +A fourth GI, the user data identifier, is defined to specify a user data sub-field used in conjunction with the “general purpose” FI. The user data sub-field contains data link user information to be transferred during XID frame interchange. This data link user information is transported transparently across the data link and passed to the user of the data link. This sub-field follows all data link layer sub-fields, as Figure C-2/T.90 shows. The subsequent information (i.e. user data field), which is bounded by the frame’s FCS field, is not constrained in ISO/IEC Standard 8885. + +*Note* – This Recommendation does not make use of the user data sub-field. + +## C.3 Single-frame exchange negotiation procedures + +The single-frame exchange process discussed in ISO 8885 shall be used to negotiate modulo and k parameter. + +Prior to the establishment of the data link layer the calling terminal sends an XID command frame with a poll (P) bit set to “1” with an information field containing an offered profile of supportable parameters and shall start a system defined timer. The called terminal then initiates an XID response frame with the final (F) bit set to “1” to acknowledge the receipt of a command frame with P bit set to “1” with an information field that indicates the parameter selection from the profile. These procedures shall be in accordance with ISO 4335. + +*Note* – This system defined timer is the same as T1. + +## C.4 Encodings for XID information field for negotiation of modulo and k parameter + +The following are the encodings for negotiation/indication of parameter values and optional procedures for the calling and the called terminals. + +The calling terminal shall indicate the modulo and the transmit and the receive k parameters. The called terminal, similarly, shall indicate the modulo and the receive k parameters. + +The information field shall be encoded as specified in Figure C-3/T.90. Fields that are not recognized shall be ignored. + +| Octet | Bit | | | | | | | | | +|-------|-----|----------------|----|----|-----|-----|----|----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------| +| | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | | +| 1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | Format identifier (FI) = General purpose XID information field identifier | +| 2 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | Group identifier (GI) = Parameter negotiation identifier | +| 3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | } Group length (GL) = Length of the parameter field in octets (set to the value of 11 octets) | +| 4 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 1 | | +| 5 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | Parameter identifier (PI) = HDLC optional functions identifier | +| 6 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | Parameter length (PL) = 3 octets | +| 7 | x | x | x | x | x | x | x | x | } Parameter value (PV): bit 11 = modulo 8 bit 12 = modulo 128. Bit 11 and/or bit 12 can be set to 0 and/or 1 to indicate/negotiate the value supported/required | +| 8 | x | x | x | x | 1/0 | 1/0 | x | x | | +| 9 | x | x | x | x | x | x | x | x | | +| 10 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | Parameter identifier (PI) = k parameter (transmit) | +| 11 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | Parameter length (PL) = 1 octet | +| 12 | 0 | 2 6 | -- | -- | -- | -- | -- | 2 0 | Parameter value (PV) = Value of k parameter for transmitter | +| 13 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | PI = k parameter (receive) | +| 14 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | Parameter length (PL) = 1 octet | +| 15 | 0 | 2 6 | -- | -- | -- | -- | -- | 2 0 | Parameter value (PV) = Value of k parameter for receiver | + +T0805761-91 + +FIGURE C-3/T.90 +XID command information field encodings for negotiation of layer 2 +parameters: modulo and k parameter + +### C.4.1 Format identifier sub-field + +For negotiation/indication of parameter values and optional procedures, the FI sub-field shall be encoded as “10000010” to indicate the ISO-standardized “general purpose” FI. + +### C.4.2 Data link layer sub-fields + +Only the data link layer sub-field associated with “parameter negotiation” shall be present. This sub-field has a GI value of “10000000”. The length of this sub-field (GL) is dependent on the actual information to be transmitted and is eleven octets (maximum) in length. + +Each item to be negotiated and/or indicated is identified by a PI. The first PI shall be encoded with the HDLC optional functions identifier. The first PL field shall be encoded to indicate the length of the parameter field. The PV field shall be set to the desired value for modulo. + +The second PI field shall be encoded with the k parameter (transmit) identifier. The second PL field shall be encoded to indicate the length of the parameter field. The PV field shall be set to the desired value of transmit k parameter. + +The third PI field shall be encoded with the k parameter (receive) identifier. The third PL field shall be encoded to indicate the length of the parameter field. The PV field shall be set to the desired value of receive k parameter. + +Table C-1/T.90 shows the items and their PI values. + +TABLE C-1/T.90 +Parameters/procedures + +| Parameter identifier (PI) | | Parameter/procedure | Units | +|---------------------------|----------|---------------------------------|----------| +| Decimal | Binary | | | +| 3 | 00000011 | HDLC optional functions | (Note 1) | +| 7 | 00000111 | k parameter: transmit direction | (Note 2) | +| 8 | 00001000 | k parameter: receive direction | (Note 2) | + +*Note 1* – The length of parameter value (PV) is three octets (i.e. PL = 3). The bits in these octets constitute a 24-bit mask, each for a particular HDLC optional function (as defined in ISO 8885). Bit 1 of this mask is the lower-order bit of octet 1 and is transmitted first; bit 9 is the lower-order bit of octet 2; etc. + +Only bits 11 and 12 are applicable to modulo negotiation. Bit 11 when set to “1” indicates support of modulo 8, bit 12 when set to “1” indicates support of modulo 128 (see Note 3). When both bits (11 and 12) are set to “1”, it indicates that the terminal supports both modulo 8 and 128. A-bit position set to “1” indicates request/agreement to use the procedure. A bit position set to “0” indicates no request/no agreement to use the procedure. + +The terminal responding to an XID command frame will negotiate modulo value as follows. The XID command frame may have bit 11 set to “1”, bit 12 set to “1” or both bits 11 and 12 set to “1”. The XID response frame shall only have bit 11 or bit 12 set to “1” (but not both). The bit chosen to be set to “1” in the XID response frame must have been set to “1” in the XID command frame. + +*Note 2* – The length of the parameter value (PV) is one octet (i.e. PL = 1). The parameter value is encoded in binary. Within an octet, the first bit transmitted shall be the lowest-order bit. + +*Note 3* – The XID command frame is not allowed to have bit 11 set to “0”, bit 12 set to “1”, because modulo 8 is mandatory. + +The terminal responding to an XID command frame will negotiate k parameter as follows. The k parameter value for the transmit direction sent in the XID response frame shall be equal to or less than the k parameter value for the receive direction received in the XID command frame. Similarly, the k parameter value for the receive direction sent in the XID response frame shall be equal to or less than the k parameter value for the transmit direction received in the XID command frame. + +## C.5 *Connectivity with terminals not supporting XID procedures* + +For the purposes of this Recommendation, the following procedures shall be adopted by a called terminal that does not support the XID procedures. + +- a) called terminal receives an XID command frame from the calling terminal in the disconnected phase: + - the called terminal shall transmit a disconnected mode (DM) frame with an F bit set to “1” to acknowledge the receipt of an XID command with a P set to “1”; + - the calling terminal then shall set up the connection using default values for modulo and the k parameter; +- b) called terminal receives an XID command from the calling terminal in information transfer phase: + - the called terminal shall transmit a frame reject (FRMR) frame with the F bit set to “1” and shall reset the connection under these conditions; + - if further communication is necessary, the calling terminal shall re-establish connection with the called terminal (with default values for modulo and k parameter). + +## C.6 *Protocol errors* + +For the purposes of this Recommendation, the following shall be considered as protocol errors: + +- a terminal receives an XID command frame (for HDLC optional functions) with both bit 11 and bit 12 set to “0”; +- a terminal receives an XID command frame with transmit or receive k parameter value of “0”; +- a terminal receives an XID command frame with the modulo as 8 and the value of either k parameter greater than 7; +- a calling terminal receives an XID response frame (for HDLC optional functions) with both bit 11 and 12 set to “0”; +- a terminal receives an XID response frame (for HDLC optional functions) with both 11 and 12 set to “1”; +- a terminal receives an XID response frame with transmit or receive k parameter value of “0”; +- a terminal receives an XID response frame with the modulo as 8 and the value of the transmit k parameter field greater than 7; +- a terminal receives an XID response frame with a k parameter violating the negotiation rules; +- a terminal receives an XID response frame with a modulo value violating the negotiation rules. + +When a protocol error occurs, the receiving terminal shall transmit a disconnected mode (DM) frame with an F bit set to 1 and exit XID procedures. + +(to Recommendation T.90) + +## **SDL diagram for link set up for SABM/SABME procedures** + +![SDL diagram for link set up for SABM/SABME procedures. The diagram shows the flow from a decision on extended mode support to either SABME or SABM procedures, including counters, timeouts, and various message exchanges.](05eb72d372e4bf78e3d6a64949d77bcc_img.jpg) + +``` + +graph TD + Entry((1)) -- "from 2 in Figure E-1/T.90" --> D1{Extended mode supported? (Note)} + D1 -- True --> C1[Counter := 0] + D1 -- False --> SABM[SABM] + C1 --> D2{Counter = N4?} + D2 -- True --> SABM + D2 -- False --> SABME[SABME] + SABME --> T1[Start T1] + T1 --> UA[UA] + T1 --> DM1[DM reponse] + T1 --> T1T[Timeout T1] + T1 --> O[Otherwise] + T1 --> SABM2[SABM] + T1 --> DISC[DISC] + T1 --> SABME2[SABME] + UA --> E1[Extended mode established, link setup; cf. X.75 SLP] + DM1 --> C2[Counter := counter + 1] + T1T --> C2 + O --> C2 + SABM2 --> DM2[DM reponse] + DISC --> DM2 + SABME2 --> E2[Extended mode, to link setup; cf. X.75 SLP] + SABM --> E3[Normal mode, to link setup; cf. X.75 SLP] + C2 --> Exit1((2)) + DM2 --> Exit2((1)) + +``` + +The diagram illustrates the link setup procedure for SABM/SABME. It begins with a decision on whether extended mode is supported. If true, the counter is set to 0, and a decision is made on whether the counter equals N4. If true, the SABM procedure is initiated. If false, the SABME procedure is initiated. The SABME procedure starts a timer T1 and enters a loop where it can receive UA, DM reponse, Timeout T1, Otherwise, SABM, DISC, or SABME. If UA, DM reponse, Timeout T1, or Otherwise is received, the counter is incremented. If SABM or DISC is received, a DM reponse is sent. If SABME is received, the extended mode link setup is completed. If SABM is received from the start, the normal mode link setup is completed. The diagram ends with two exit points: 1 and 2. + +SDL diagram for link set up for SABM/SABME procedures. The diagram shows the flow from a decision on extended mode support to either SABME or SABM procedures, including counters, timeouts, and various message exchanges. + +*SLP Single link procedure**Note – It is strongly recommended to use the extended mode of operation.* + +T0805771-91 + +**FIGURE D-1/T.90** +**Calling side** + +![Flowchart for Called side showing the process from Start to Disconnected mode, branching into XID, SABME, SABM, and Otherwise paths with decision points for XID supported? and Extended mode supported?.](f9c64800d9bace9b4315646d1057be3c_img.jpg) + +``` + +graph TD + Start([Start]) --> DM1([Disconnected mode]) + DM1 --> Junction(( )) + Junction --> XID1[/XID/] + Junction --> SABME[/SABME/] + Junction --> SABM[/SABM/] + Junction --> Otherwise[/Otherwise/] + + XID1 --> D1{ } + SABME --> D2{ } + + D1 -.->|XID supported?| D1 + D2 -.->|Extended mode supported?| D2 + + D1 -- (False) --> DM2[/DM/] + D1 -- (True) --> XID2[/XID/] + D2 -- (False) --> DM3[/DM/] + D2 -- (True) --> UA1[/UA/] + + DM2 --> DM3a([Disconnected mode]) + XID2 --> LinkSetup1[To link setup: cf. XID information] + DM3 --> DM3b([Disconnected mode]) + UA1 --> LinkSetup2[Extended mode established, link setup; cf. X.75 SLP] + SABM --> UA2[/UA/] + UA2 --> LinkSetup3[Normal mode established, link setup; cf. X.75 SLP] + Otherwise --> DM4[/DM/] + DM4 --> DM4a([Disconnected mode]) + +``` + +The flowchart illustrates the process for the called side, starting from a 'Start' terminal and entering 'Disconnected mode'. It then branches into four main paths: XID, SABME, SABM, and Otherwise. The XID and SABME paths include decision points for 'XID supported?' and 'Extended mode supported?' respectively. Depending on the outcome of these decisions, the process may transition to 'Disconnected mode', 'XID', 'UA', or 'Normal mode established, link setup; cf. X.75 SLP'. + +Flowchart for Called side showing the process from Start to Disconnected mode, branching into XID, SABME, SABM, and Otherwise paths with decision points for XID supported? and Extended mode supported?. + +T0805781-91 + +FIGURE D-2/T.90 +Called side + +# ANNEX E (to Recommendation T.90) + +## SDL diagram for link set up to a T.90 compatible terminal for XID procedure + +![SDL diagram for link set up to a T.90 compatible terminal for XID procedure. The diagram shows the flow from 'Start' to 'Disconnected mode', then to a decision 'Transmit terminal supports XID?'. If 'True', 'Counter := 0' and a loop starts with decision 'Counter = N3?'. If 'True', it goes to '2'. If 'False', it sends 'XID', starts 'T1', and enters a parallel block with 'XID', 'DM', 'Time out T1', 'FRMR', and 'Otherwise'. 'XID' leads to a decision 'T.90 compatible?'. If 'True', it goes to 'SABME'. If 'False', it sends 'DM' and leads to '2'. 'DM' leads to a decision 'Normal mode selected?'. If 'True', it sends 'SABM'. If 'False', it sends 'SABME'. 'Time out T1' increments the counter and loops back. 'FRMR' and 'Otherwise' lead to '2'. A note indicates '2' refers to '1' in Figure D-1/T.90.](1142ba0197b158bb198186fe8baccc32_img.jpg) + +``` + +graph TD + Start([Start]) --> DisconnectedMode{{Disconnected mode}} + DisconnectedMode --> Decision1{ } + Decision1 -- (True) --> Counter0[Counter := 0] + Decision1 -- (False) --> Note1[Transmit terminal supports XID?] + Note1 --> 2((2)) + + Counter0 -- 1((1)) --> Decision2{ } + Decision2 -- (True) --> 2 + Decision2 -- (False) --> Note2[Counter = N3? 0 < N3 ≤ 2 N3: XID transmission counter] + Note2 --> 2 + + Note2 --> XID1[/XID/] + XID1 --> StartT1[Start T1] + StartT1 --> ParallelBlock + subgraph ParallelBlock [ ] + direction LR + XID2[/XID/] + DM[/DM/] + TimeoutT1[/Time out T1/] + FRMR[/FRMR/] + Otherwise[/Otherwise/] + end + + XID2 --> Decision3{ } + Decision3 -- (True) --> Note3[T.90 compatible?] + Note3 --> SABME1[/SABME/] + Note3 -- (False) --> Note4[(False) (Note)] + Note4 --> DM2[/DM/] + DM2 --> 2 + + DM --> Decision4{ } + Decision4 -- (True) --> Note5[Normal mode selected?] + Note5 --> SABM[/SABM/] + Decision4 -- (False) --> SABME2[/SABME/] + SABME2 --> 2 + + TimeoutT1 --> CounterInc[Counter := counter + 1] + CounterInc -- 1 --> Decision2 + + FRMR --> 2 + Otherwise --> 2 + +``` + +T0805791-91 + +② : to ① in Figure D-1/T.90 + +Extended mode link setup;    Normal mode link setup; + +SDL diagram for link set up to a T.90 compatible terminal for XID procedure. The diagram shows the flow from 'Start' to 'Disconnected mode', then to a decision 'Transmit terminal supports XID?'. If 'True', 'Counter := 0' and a loop starts with decision 'Counter = N3?'. If 'True', it goes to '2'. If 'False', it sends 'XID', starts 'T1', and enters a parallel block with 'XID', 'DM', 'Time out T1', 'FRMR', and 'Otherwise'. 'XID' leads to a decision 'T.90 compatible?'. If 'True', it goes to 'SABME'. If 'False', it sends 'DM' and leads to '2'. 'DM' leads to a decision 'Normal mode selected?'. If 'True', it sends 'SABM'. If 'False', it sends 'SABME'. 'Time out T1' increments the counter and loops back. 'FRMR' and 'Otherwise' lead to '2'. A note indicates '2' refers to '1' in Figure D-1/T.90. + +*Note* – Further analysis of the "non-T.90 compatible case" may lead to terminal characteristics suitable for the intended communication. + +FIGURE E-1/T.90 +Calling side + +# APPENDIX I + +(to Recommendation T.90) + +## Facsimile terminals in the ISDN + +## I.1 *Outgoing calls* + +In accordance with Recommendation I.333, § I.2.2.1.1, a terminal which supports both G2/G3 and G4 facsimile function or a G4 facsimile terminal attempting a G4 facsimile call (either polling or sending) should use the bearer capability according to the capabilities of the network, which may be either “circuit-mode 64 kbit/s unrestricted 8 kHz structured” (category Recommendation I.231.1) or “virtual call” (category Recommendation I.232.1), or both of them, and provide the HLC information element with high layer characteristics identification “facsimile Group 4”. + +In accordance with Recommendation I.333, § I.2.2.1.1, a terminal adaptor (TA) supporting a G2/G3 facsimile terminal should use the 3.1 kHz audio bearer capability and should provide the HLC information element with high layer characteristics identification “facsimile Group 2/3”. + +The actions to be taken by the calling facsimile terminal following an unsuccessful call attempt where incompatibility has been indicated (e.g. cause “incompatible destination” for calls within the ISDN, or call rejection with a suitable cause indication in the case of interworking with a dedicated network) require further study. The optimum condition to achieve compatibility in a call re-attempt greatly depends on the cause indication provided to the calling facsimile terminal and its capability to divert to the requested characteristics for the call re-attempt (see note). For a certain type of facsimile terminal these actions may include: + +- i) A G2/G3 facsimile terminal should release the call and take no further action. +- ii) A G4 facsimile terminal should release the call. + - The G4 facsimile terminal may initiate a call re-attempt, if a mismatch of the bearer capability has been indicated and it can match the requested characteristics, e.g. in the case where the “virtual call” (category Recommendation I.232.1) bearer capability has been requested by the calling facsimile terminal and interworking with switched 64 kbit/s non-ISDN network takes place. Otherwise, it cannot take further actions and is unable to communicate with the called facsimile terminal. +- iii) A terminal which supports both G2/G3 and G4 facsimile function should release the call. + - If interworking ISDN to PSTN has been indicated, or cause “incompatible destination” for calls within the ISDN, when the call has been rejected, the terminal which supports both G2/G3 and G4 facsimile function may initiate a re-attempt in the G2/G3 mode. It should use the 3.1 kHz audio bearer capability and should provide the HLC information element with high layer characteristics identification “facsimile Group 2/3”. + - If interworking ISDN, to switched 64 kbit/s non-ISDN network, has been indicated when the call has been rejected, actions according to item ii) may be appropriate. + +*Note* – For evolution, further study is also required to eliminate the method which may result in unsuccessful calls caused by incompatibility. + +### I.2 *Incoming calls* + +For incoming calls originated within ISDN, the facsimile terminal should function as described for terminals supporting teleservices in Recommendation I.333, § I.2.2. + +For incoming calls from non-ISDN networks not able to convey high layer compatibility information such as the public switched telephone network (PSTN) or switched 64 kbit/s network, the facsimile terminal will receive the appropriate information indicating an interworking situation (call progress information). It should rely on the call + +progress information element to accept calls which are offered without the explicit information specifying high layer protocols, if it matches other elements describing the incoming call. Otherwise it should release or ignore the call (user options). + +In this case the directory number (see Recommendation E.164) should be the overriding determinant of whether the terminal responds (provided the bearer capability is appropriate). In this case the use of Multiple Subscriber Number (MSN) supplementary service could be advisable because it is the only means to avoid having facsimile terminal accept calls which are not appropriate to it, e.g. incoming call from non-ISDN networks such as telephone calls or data calls. + +The rules below are applicable to a certain type of facsimile terminal. They define the criteria which should be used by the terminal to determine whether, and in what mode, it should answer the call: + +- i) A TA supporting a G2/G3 facsimile terminal should answer the call if the following criteria are fulfilled: + - a) the called party number information element, if present, contains a number which matches the number assigned to the TA; and + - b) the bearer capability information element indicates the information transfer capability “3.1 kHz audio”;and for incoming call from PSTN: + - c1) the progress indicator information element (in Recommendation Q.931 SETUP) indicates the progress description “call is not end-to-end ISDN” (incoming call from PSTN); + - d1) the high layer compatibility information element is not present; and + - e1) the called party sub-address information element is not present;or for incoming call from ISDN [instead of c1), d1), e1)]: + - c2) the progress indicator information element is not present (incoming call from ISDN); + - d2) the high layer compatibility information element indicates high layer characteristics identification “facsimile Group 2/3”; and + - e2) the called party sub-address information element, if present, contains a number which matches the sub-address assigned to the terminal. +- ii) A terminal which supports both G2/G3 and G4 facsimile function should answer the call in the G2/G3 mode (including modem and codec functions) if the following criteria are fulfilled (incoming call from PSTN): + - a) the called party number information element, if present, contains a number which matches the number assigned to the terminal; + - b) the bearer capability information element indicates the information transfer capability “3.1 kHz audio”; + - c) the progress indicator information element indicates the progress description “call is not end-to-end ISDN”; + - d) the high layer compatibility information element is not present; and + - e) the called party sub-address information element is not present. +- iii) A terminal which supports both G2/G3 and G4 facsimile function (or a G4 facsimile terminal) should answer the call in the G4 mode (neither modem nor codec functions) if the following criteria are fulfilled (incoming call from switched 64 kbit/s network (non-ISDN)): + - a) the called party number information element, if present, contains a number which matches the number assigned to the terminal; + +- b) the bearer capability information element indicates the information transfer capability “unrestricted digital information” and transfer mode “circuit mode”; +- c) the progress indicator information element indicates the progress description “call is not end-to-end ISDN (see Note); +- d) the high layer compatibility information element is not present; and +- e) the called party sub-address information element is not present. + +*Note* – It may not always be possible to determine whether source is ISDN or 64 kbit/s switched network. + +- iv) A terminal which supports both G2/G3 and G4 facsimile function (or a G4 facsimile terminal) should answer the call in the G4 mode (neither modem nor codec functions) if the following criteria are fulfilled (incoming call from ISDN): + - a) the called party number information element, if present, contains a number which matches the number assigned to the terminal; + - b) the bearer capability information element indicates the information transfer capability “unrestricted digital information” and a transfer mode which is supported by the called facsimile terminal (“circuit mode” or “packet mode”); + - c) the progress indicator information element is not present; + - d) the high layer compatibility information element indicates high layer characteristics identification “facsimile Group 4”; and + - e) the called party sub-address information element, if present, contains a number which matches the sub-address assigned to the terminal. + +## I.3 *Information elements for the provision of G2/G3 facsimile transmission* + +In this section the protocol and use of information elements (BC, LLC, HLC) for the provision of G2/G3 facsimile transmission at the S/T reference point are specified for D-channel connection control phase. + +### I.3.1 *Application rules* + +#### 1) *Layer 1 – Physical layer interface characteristics* + +Paragraph 2.2.1 should be used. + +#### 2) *Layer 2 – D-channel connection control phase* + +Paragraph 2.2.2 should be used for connection control phase. + +#### 3) *Layer 3 – D-channel connection control phase* + +Recommendation Q.931 should be used for connection control phase. All encodings should be derived from the relevant section in Recommendation Q.931. + +Fields in bearer capability (BC), low layer compatibility (LLC) and high layer compatibility (HLC) information elements to be conveyed at the S/T reference point of the user-network interface during the call establishment phase, should be set to the values defined below. Any other information element of BC, LLC or HLC not defined in the below tables is not used. + +##### – *Bearer capability (BC)* + +See Table I-1/T.90. + +##### – *Low layer compatibility (LLC)* + +See Table I-2/T.90. + +##### – *High layer compatibility (HLC)* + +See Table I-3/T.90. + +#### 4) For B-channel, see the relevant Recommendation of G2/G3 facsimile. + +TABLE I-1/T.90 + +##### **Bearer capability for G2/G3 facsimile transmission** + +| Octet number | Information elements | G2/G3 facsimile | | | +|--------------|-----------------------------------------------------------------------------|--------------------------------------------------------------------------------|-------------------------------------|------------------------------------| +| | | Contents | Condition for calling side (Note 1) | Condition for called side (Note 1) | +| 1 | Bearer capability information element identifier | Identifier | M | M | +| 2 | Length of the bearer capability contents | Length | M | M | +| 3 | Extension
Coding standard

Information transfer capability | Extension
CCITT
standardized coding
3.1 kHz audio
(Note 2) | M

M
M | M

M
M | +| 4 | Extension
Transfer mode
Information transfer rate | Extension
Circuit mode
64 kbit/s | M
M
M | M
M
M | +| 5 | Extension
Layer 1 identification
User information layer 1
protocol | Extension
Layer 1 identifier
G.711 $\mu$ -law or
G.711 A-law (Note 3) | M
M

M | O
O

O | +| 6 | Extension
Layer 2 identification
User information layer 2
protocol | | N
N

N | N
N

N | +| 7 | Extension
Layer 3 identification
User information layer 3
protocol | | N
N

N | N
N

N | + +*Note 1* – M: Sending is mandatory for calling side, and checking of its presence and contents is mandatory for called side. + +O: If present, called side checks the information element. + +N: Calling side does not send the information element, and called side does not care for the information element. + +*Note 2* – Basically, G2/G3 facsimile should respond to the incoming call of which information transfer capability is 3.1 kHz audio. However, it should be noted that in some case there may be G2/G3 incoming call of which information transfer element is speech. + +*Note 3* – Either $\mu$ -law or A-law is used. + +TABLE I-2/T.90 + +##### **Low layer compatibility for G2/G3 facsimile transmission** + +| Octet number | Information elements | G2/G3 facsimile | | | +|--------------|--------------------------------------------------------------------------|--------------------------------------------------------------------------------|-------------------------------------|------------------------------------| +| | | Contents | Condition for calling side (Note 1) | Condition for called side (Note 1) | +| 1 | Low layer compatibility information element identifier | Identifier | M | O | +| 2 | Length of the low layer compatibility contents | Length | M | O | +| 3 | Extension
Coding standard

Information transfer capability | Extension
CCITT standardized coding
3.1 kHz audio
(Note 2) | M
M
M | O
O
O | +| 4 | Extension
Transfer mode
Information transfer rate | Extension
Circuit mode
64 kbit/s | M
M
M | O
O
O | +| 5 | Extension
Layer 1 identification
User information layer 1 protocol | Extension
Layer 1 identifier
G.711 $\mu$ -law or
G.711 A-law (Note 3) | M
M

M | O
O

O | +| 6 | Extension
Layer 2 identification
User information layer 2 protocol | | N
N

N | N
N

N | +| 7 | Extension
Layer 3 identification
User information layer 3 protocol | | N
N

N | N
N

N | + +*Note 1* – M: Sending is mandatory for calling side, and checking of its presence and contents is mandatory for called side. + +O: If present, called side checks the information element. + +N: Calling side does not send the information element, and called side does not care for the information element. + +In case that the received information elements of LLC are different from that of BC, information elements of BC have priority. + +*Note 2* – Basically, G2/G3 facsimile should respond to the incoming call of which information transfer capability is 3.1 kHz audio. However, it should be noted that in some case there may be G2/G3 incoming call of which information transfer element is speech. + +*Note 3* – Either $\mu$ -law or A-law is used. + +TABLE I-3/T.90 + +##### **High layer compatibility for G2/G3 facsimile transmission** + +| Octet number | Information elements | G2/G3 facsimile | | | +|--------------|--------------------------------------------------------------|-------------------------------------------------|-----------------------------------|----------------------------------| +| | | Contents | Condition for calling side (Note) | Condition for called side (Note) | +| 1 | High layer compatibility information element identifier | Identifier | M | O | +| 2 | Length of high layer compatibility contents | Length | M | O | +| 3 | Extension coding standard | Extension CCITT standardized coding | M | O | +| | Interpretation | First high layer characteristics identification | M | O | +| | Presentation method of protocol profile | High layer protocol profile | M | O | +| | | | M | O | +| 4 | Extension High layer characteristics identification | Extension Facsimile group 2/3 | M
M | O
O | +| 4a | Extension Extended high layer characteristics identification | | N | N | +| | | | N | N | + +*Note* – M: Sending is mandatory for calling side, and checking of its presence and contents is mandatory for called side. + +O: If present, called side checks the information element. + +N: Calling side does not send the information element, and called side does not care for the information element. + +# APPENDIX II + +(to Recommendation T.90) + +## Optional usage of T.70 network layer (NL) protocol + +### II.1 *Information transfer phase* + +The T.70 NL option being used by the calling DTE and supported by the called DTE. + +The network layer for the connection control phase should be as defined in § 2.2.5. The information transfer phase should be implemented as defined in CCITT Recommendation T.70, § 3.3.3. + +![Sequence diagram showing the initial connection setup between Calling DTE and Called DTE.](798679874d1c29f8343506a156c79d7e_img.jpg) + +``` + +sequenceDiagram + participant C as Calling DTE + participant D as Called DTE + C->>D: SABM/SABME + D->>C: UA + C->>D: TRANSPORT CONNECTION SET-UP + D->>C: TRANSPORT CONNECTION ACCEPT + +``` + +T0810900-92/d15 + +Sequence diagram showing the initial connection setup between Calling DTE and Called DTE. + +FIGURE II-1/T.90 + +### II.2 *Information transfer phase* + +The T.70 NL option being proposed by the calling DTE but not supported by the called DTE. + +![Sequence diagram showing the information transfer phase with a rejected NL option.](ddee3e67e0dfc22e25188fa635a19558_img.jpg) + +``` + +sequenceDiagram + participant C as Calling DTE + participant D as Called DTE + C->>D: SABM/SABME + D->>C: UA + C->>D: TRANSPORT CONNECTION SET-UP + D->>C: DIAGNOSTIC PACKET + C->>D: X.25 RESTART REQUEST + D->>C: X.25 RESTART CONFIRMATION + C->>D: X.25 CALL REQUEST + D->>C: X.25 CALL CONNECTED + C->>D: TRANSPORT CONNECTION SET-UP + D->>C: TRANSPORT CONNECTION ACCEPT + +``` + +T0810910-92/d16 + +Sequence diagram showing the information transfer phase with a rejected NL option. + +FIGURE II-2/T.90 + +# APPENDIX III + +(to Recommendation T.90) + +## **Service definitions and state transition diagrams for the data link layer within the B-channel (CS-mode)** + +This Appendix contains the result of experience of several implementations of the prescribed link layer for telematic services. This description has been found to be useful in some Administrations for support of conformance testing. + +Additional work may be needed in the area of ISDN management and maintenance, however, no clear set of requirements is available at this time. The support of the management and maintenance work is left for further study. + +In addition, depending on the further work on the link layer, particularly related to the base modulus for I-frames, some editing may be required (e.g. SABM may become SABME). + +*Note* – Reference to the appropriate section of Recommendation T.70 or an additional explanation is needed. + +### III.1 *Service definitions* + +### III.1.1 *Physical service (PHS) used by HDLC* + +![Sequence diagram showing PH-data transfer between PHS user and PHS provider.](0d0897dd7f03672d186db9d56ea0d6f5_img.jpg) + +``` +sequenceDiagram + participant PHS_user1 as PHS user + participant PHS_provider as PHS provider + participant PHS_user2 as PHS user + PHS_user1->>PHS_provider: PH-DATA request + PHS_provider->>PHS_user2: PH-DATA indication +``` + +The diagram illustrates the data transfer process. It features three vertical lifelines: 'PHS user' on the left, 'PHS provider' in the center, and 'PHS user' on the right. Below the first two lifelines is the label 'PHSAP'. An arrow labeled 'PH-DATA request' originates from the first 'PHS user' and points to the 'PHS provider' lifeline. A second arrow labeled 'PH-DATA indication' originates from the 'PHS provider' lifeline and points to the second 'PHS user' lifeline. The reference 'T0810920-92/d17' is located at the bottom right of the diagram. + +Sequence diagram showing PH-data transfer between PHS user and PHS provider. + +FIGURE III-1/T.90 + +**PH-data transfer** + +### III.1.2 Data link service + +#### III.1.2.1 Data link connection establishment + +![Sequence diagram for successful DLC-establishment showing interactions between DLS user and DLS provider.](60ffbad6c0fb7371a57fe8f267d2d141_img.jpg) + +This sequence diagram illustrates the successful establishment of a Data Link Connection (DLC) between a DLS user and a DLS provider. The diagram features three vertical lifelines: DLS user (left), DLS provider (center), and DLS user (right). The DLS user lifelines are connected to a DLSAP (Data Link Service Access Point) at the bottom. The DLS provider lifeline is connected to a DLSAP at the bottom. The sequence of events is as follows: 1. The DLS user on the left sends a DL-ACTIVATE request to the DLS provider. 2. The DLS provider sends a DL-ACTIVATE confirm back to the DLS user on the left. 3. The DLS user on the left sends a DL-CONNECT request to the DLS provider. 4. The DLS provider sends a SABM (Set Asynchronous Balanced Mode) message to the DLS user on the right. 5. The DLS user on the right sends a DL-CONNECT indication back to the DLS provider. 6. The DLS provider sends a UA (Unacknowledged Sequence) message back to the DLS user on the left. 7. The DLS user on the left sends a DL-CONNECT confirm back to the DLS provider. The diagram is labeled T0810930-92/d18. + +Sequence diagram for successful DLC-establishment showing interactions between DLS user and DLS provider. + +FIGURE III-2/T.90 +Successful DLC-establishment + +![Sequence diagram for not successful DLC-establishment showing interactions between DLS user and DLS provider.](f142b022cfc716cd967297f027efe647_img.jpg) + +This sequence diagram illustrates a failed attempt at establishing a Data Link Connection (DLC) between a DLS user and a DLS provider. The diagram features three vertical lifelines: DLS user (left), DLS provider (center), and DLS user (right). The DLS user lifelines are connected to a DLSAP (Data Link Service Access Point) at the bottom. The DLS provider lifeline is connected to a DLSAP at the bottom. The sequence of events is as follows: 1. The DLS user on the left sends a DL-ACTIVATE request to the DLS provider. 2. The DLS provider sends a DL-ACTIVATE confirm back to the DLS user on the left. 3. The DLS user on the left sends a DL-CONNECT request to the DLS provider. 4. The DLS provider sends a DL-DISCONNECT indication back to the DLS user on the left. 5. The DLS provider sends a SABM (Set Asynchronous Balanced Mode) message to the DLS user on the right. 6. The DLS user on the right sends a DL-CONNECT indication back to the DLS provider. 7. The DLS provider sends a SABM message back to the DLS user on the left, labeled 'N2 times', indicating a retransmission. The diagram is labeled T0810940-92/d19. + +Sequence diagram for not successful DLC-establishment showing interactions between DLS user and DLS provider. + +FIGURE III-3/T.90 +Not successful DLC-establishment + +#### III.1.2.2 Data link transfer phase + +![Sequence diagram for DL-data transfer showing the flow from DLS user to DLS provider and then to another DLS user.](6cc85a2b62fd8a2a3faab29730f20e81_img.jpg) + +``` +sequenceDiagram + participant U1 as DLS user + participant P as DLS provider + participant U2 as DLS user + U1->>P: DL-DATA request + P->>U2: I-frame + U2->>U2: DL-DATA indication +``` + +The diagram illustrates the data link transfer phase. It shows three vertical lifelines: DLS user (left), DLS provider (middle), and DLS user (right). The DLS user on the left sends a 'DL-DATA request' to the DLS provider. The DLS provider then sends an 'I-frame' to the DLS user on the right. Finally, the DLS user on the right receives a 'DL-DATA indication'. Below the lifelines, the labels 'DLSAP' are positioned under the first and third lifelines. The reference 'T0810950-92/d20' is located at the bottom right. + +Sequence diagram for DL-data transfer showing the flow from DLS user to DLS provider and then to another DLS user. + +FIGURE III-4/T.90 + +##### DL-data transfer + +#### III.1.2.3 Data link release + +![Sequence diagram for DL-release initiated by DL-user showing the flow of DISCONNECT and DEACTIVATE messages.](b44f89b176c971c7dd264c07bfef2c2a_img.jpg) + +``` +sequenceDiagram + participant U1 as DLS user + participant P as DLS provider + participant U2 as DLS user + U1->>P: DL-DISCONNECT request + P->>U2: DISC + U2->>U2: DL-DISCONNECT indication + U2->>P: UA + P->>U1: DL-DISCONNECT confirm + U1->>P: DL-DEACTIVATE request + P->>U2: DL-DEACTIVATE request + U2->>U2: DL-DEACTIVATE confirm + U2->>P: DL-DEACTIVATE confirm +``` + +The diagram illustrates the data link release phase initiated by the DLS user. It shows three vertical lifelines: DLS user (left), DLS provider (middle), and DLS user (right). The sequence of messages is as follows: 1. The DLS user on the left sends a 'DL-DISCONNECT request' to the DLS provider. 2. The DLS provider sends a 'DISC' message to the DLS user on the right. 3. The DLS user on the right receives a 'DL-DISCONNECT indication'. 4. The DLS user on the right sends a 'UA' message to the DLS provider. 5. The DLS provider sends a 'DL-DISCONNECT confirm' message to the DLS user on the left. 6. The DLS user on the left sends a 'DL-DEACTIVATE request' to the DLS provider. 7. The DLS provider sends a 'DL-DEACTIVATE request' to the DLS user on the right. 8. The DLS user on the right receives a 'DL-DEACTIVATE confirm'. 9. The DLS user on the right sends a 'DL-DEACTIVATE confirm' message to the DLS provider. Below the lifelines, the labels 'DLSAP' are positioned under the first and third lifelines. The reference 'T0810960-92/d21' is located at the bottom right. + +Sequence diagram for DL-release initiated by DL-user showing the flow of DISCONNECT and DEACTIVATE messages. + +FIGURE III-5/T.90 + +##### DL-release initiated by DL-user + +![Sequence diagram for DL-release initiated by DL-provider. It shows three lifelines: DLS user (left), DLS provider (middle), and DLS user (right). The DLS provider sends a DL-DISCONNECT indication to the left DLS user and a DL-DEACTIVATE request to the right DLS user. The left DLS user sends a DL-DEACTIVATE confirm back to the DLS provider. The right DLS user sends a DL-DEACTIVATE confirm back to the DLS provider. DLSAP labels are at the bottom of the lifelines.](c1df61cc3717e878a48e530218403403_img.jpg) + +``` + +sequenceDiagram + participant DLS_user1 as DLS user + participant DLS_provider as DLS provider + participant DLS_user2 as DLS user + DLS_provider->>DLS_user1: DL-DISCONNECT indication + DLS_provider->>DLS_user2: DL-DEACTIVATE request + DLS_user1-->>DLS_provider: DL-DEACTIVATE confirm + DLS_user2-->>DLS_provider: DL-DEACTIVATE confirm + note over DLS_provider: DLSAP + note over DLS_provider: DLSAP + +``` + +T0810970-92/d22 + +Sequence diagram for DL-release initiated by DL-provider. It shows three lifelines: DLS user (left), DLS provider (middle), and DLS user (right). The DLS provider sends a DL-DISCONNECT indication to the left DLS user and a DL-DEACTIVATE request to the right DLS user. The left DLS user sends a DL-DEACTIVATE confirm back to the DLS provider. The right DLS user sends a DL-DEACTIVATE confirm back to the DLS provider. DLSAP labels are at the bottom of the lifelines. + +FIGURE III-6/T.90 +**DL-release initiated by DL-provider** + +#### III.1.2.4 Data link resetting + +![Sequence diagram for Successful resetting. It shows three lifelines: DLS user (left), DLS provider (middle), and DLS user (right). The left DLS user sends a DL-RESET indication to the DLS provider and a DL-RESET response back to the DLS provider. The DLS provider sends an FRMR to the right DLS user. The right DLS user sends a DL-RESET indication to the DLS provider and a DL-RESET response back to the DLS provider. The DLS provider sends a SABM to the left DLS user and a UA to the right DLS user. DLSAP labels are at the bottom of the lifelines.](be3e5fe8be7cc5a74f67a4b8ac93193d_img.jpg) + +``` + +sequenceDiagram + participant DLS_user1 as DLS user + participant DLS_provider as DLS provider + participant DLS_user2 as DLS user + DLS_user1->>DLS_provider: DL-RESET indication + DLS_user1-->>DLS_provider: DL-RESET response + DLS_provider->>DLS_user2: FRMR + DLS_user2->>DLS_provider: DL-RESET indication + DLS_user2-->>DLS_provider: DL-RESET response + DLS_provider->>DLS_user1: SABM + DLS_provider->>DLS_user2: UA + note over DLS_provider: DLSAP + note over DLS_provider: DLSAP + +``` + +T0810980-92/d23 + +Sequence diagram for Successful resetting. It shows three lifelines: DLS user (left), DLS provider (middle), and DLS user (right). The left DLS user sends a DL-RESET indication to the DLS provider and a DL-RESET response back to the DLS provider. The DLS provider sends an FRMR to the right DLS user. The right DLS user sends a DL-RESET indication to the DLS provider and a DL-RESET response back to the DLS provider. The DLS provider sends a SABM to the left DLS user and a UA to the right DLS user. DLSAP labels are at the bottom of the lifelines. + +FIGURE III-7/T.90 +**Successful resetting** + +![Sequence diagram for Figure III-8/T.90: Resetting not accepted by the receiver of FRMR. The diagram shows three lifelines: DLS user (left), DLS provider (middle), and DLS user (right). The DLS provider has two DLSAP interfaces. The sequence of events is: 1. DLS user sends DL-RESET indication to DLS provider. 2. DLS provider sends FRMR to DLS user. 3. DLS user sends DL-RESET response to DLS provider. 4. DLS user sends DL-DISCONNECT request to DLS provider. 5. DLS provider sends DISC to DLS user. 6. DLS provider sends UA to DLS user. 7. DLS user sends DL-DISCONNECT indication to DLS provider. 8. DLS provider sends DL-DISCONNECT confirm to DLS user. Reference: T0810990-92/d24](38cbce07f83fba6d5a7c46605bd5743f_img.jpg) + +``` + +sequenceDiagram + participant DLS_user1 as DLS user + participant DLS_provider as DLS provider + participant DLS_user2 as DLS user + + DLS_user1->>DLS_provider: DL-RESET indication + DLS_provider->>DLS_user2: FRMR + DLS_user1->>DLS_provider: DL-RESET response + DLS_user2->>DLS_provider: DL-DISCONNECT request + DLS_provider->>DLS_user1: DISC + DLS_provider->>DLS_user2: UA + DLS_user1->>DLS_provider: DL-DISCONNECT indication + DLS_provider->>DLS_user2: DL-DISCONNECT confirm + +``` + +T0810990-92/d24 + +Sequence diagram for Figure III-8/T.90: Resetting not accepted by the receiver of FRMR. The diagram shows three lifelines: DLS user (left), DLS provider (middle), and DLS user (right). The DLS provider has two DLSAP interfaces. The sequence of events is: 1. DLS user sends DL-RESET indication to DLS provider. 2. DLS provider sends FRMR to DLS user. 3. DLS user sends DL-RESET response to DLS provider. 4. DLS user sends DL-DISCONNECT request to DLS provider. 5. DLS provider sends DISC to DLS user. 6. DLS provider sends UA to DLS user. 7. DLS user sends DL-DISCONNECT indication to DLS provider. 8. DLS provider sends DL-DISCONNECT confirm to DLS user. Reference: T0810990-92/d24 + +FIGURE III-8/T.90 +Resetting not accepted by the receiver of FRMR + +![Sequence diagram for Figure III-9/T.90: Resetting not supported by the transmitter of FRMR. The diagram shows three lifelines: DLS user (left), DLS provider (middle), and DLS user (right). The DLS provider has two DLSAP interfaces. The sequence of events is: 1. DLS user sends DL-RESET indication to DLS provider. 2. DLS provider sends FRMR to DLS user. 3. DLS user sends DL-DISCONNECT request to DLS provider. 4. DLS provider sends DISC to DLS user. 5. DLS provider sends SABM to DLS user. 6. DLS user sends DL-DISCONNECT indication to DLS provider. 7. DLS provider sends DM to DLS user. 8. DLS provider sends UA to DLS user. 9. DLS user sends DL-DISCONNECT confirm to DLS provider. Reference: T0811000-92/d25](ec3647789b5c38fb686f2a0833324e79_img.jpg) + +``` + +sequenceDiagram + participant DLS_user1 as DLS user + participant DLS_provider as DLS provider + participant DLS_user2 as DLS user + + DLS_user1->>DLS_provider: DL-RESET indication + DLS_provider->>DLS_user2: FRMR + DLS_user1->>DLS_provider: DL-DISCONNECT request + DLS_provider->>DLS_user1: DISC + DLS_provider->>DLS_user2: SABM + DLS_user1->>DLS_provider: DL-DISCONNECT indication + DLS_provider->>DLS_user2: DM + DLS_provider->>DLS_user2: UA + DLS_user1->>DLS_provider: DL-DISCONNECT confirm + +``` + +T0811000-92/d25 + +Sequence diagram for Figure III-9/T.90: Resetting not supported by the transmitter of FRMR. The diagram shows three lifelines: DLS user (left), DLS provider (middle), and DLS user (right). The DLS provider has two DLSAP interfaces. The sequence of events is: 1. DLS user sends DL-RESET indication to DLS provider. 2. DLS provider sends FRMR to DLS user. 3. DLS user sends DL-DISCONNECT request to DLS provider. 4. DLS provider sends DISC to DLS user. 5. DLS provider sends SABM to DLS user. 6. DLS user sends DL-DISCONNECT indication to DLS provider. 7. DLS provider sends DM to DLS user. 8. DLS provider sends UA to DLS user. 9. DLS user sends DL-DISCONNECT confirm to DLS provider. Reference: T0811000-92/d25 + +FIGURE III-9/T.90 +Resetting not supported by the transmitter of FRMR + +![Sequence diagram showing the HDLC procedure for resetting not accepted by both DLS users. The diagram involves three entities: DLS user (left), DLS provider (center), and DLS user (right). The sequence of messages is: 1. DLS user (left) sends DL-RESET indication to DLS provider. 2. DLS provider sends FRMR to DLS user (right). 3. DLS user (left) sends DL-DISCONNECT request to DLS provider. 4. DLS provider sends DL-RESET indication to DLS user (right). 5. DLS provider sends DISC to DLS user (right). 6. DLS user (right) sends DL-DISCONNECT request to DLS provider. 7. DLS provider sends DISC to DLS user (left). 8. DLS provider sends UA to DLS user (left). 9. DLS user (left) sends DL-DISCONNECT confirm to DLS provider. 10. DLS provider sends UA to DLS user (right). 11. DLS provider sends DL-DISCONNECT confirm to DLS user (right). The diagram is labeled T0811010-92/d26.](12c19090355e19922e23044633b9d1ea_img.jpg) + +``` + +sequenceDiagram + participant DLSUser1 as DLS user + participant DLSProvider as DLS provider + participant DLSUser2 as DLS user + + DLSUser1->>DLSProvider: DL-RESET indication + DLSProvider->>DLSUser2: FRMR + DLSUser1->>DLSProvider: DL-DISCONNECT request + DLSProvider->>DLSUser2: DL-RESET indication + DLSProvider->>DLSUser2: DISC + DLSUser2->>DLSProvider: DL-DISCONNECT request + DLSProvider->>DLSUser1: DISC + DLSProvider->>DLSUser1: UA + DLSUser1->>DLSProvider: DL-DISCONNECT confirm + DLSProvider->>DLSUser2: UA + DLSProvider->>DLSUser2: DL-DISCONNECT confirm + +``` + +T0811010-92/d26 + +Sequence diagram showing the HDLC procedure for resetting not accepted by both DLS users. The diagram involves three entities: DLS user (left), DLS provider (center), and DLS user (right). The sequence of messages is: 1. DLS user (left) sends DL-RESET indication to DLS provider. 2. DLS provider sends FRMR to DLS user (right). 3. DLS user (left) sends DL-DISCONNECT request to DLS provider. 4. DLS provider sends DL-RESET indication to DLS user (right). 5. DLS provider sends DISC to DLS user (right). 6. DLS user (right) sends DL-DISCONNECT request to DLS provider. 7. DLS provider sends DISC to DLS user (left). 8. DLS provider sends UA to DLS user (left). 9. DLS user (left) sends DL-DISCONNECT confirm to DLS provider. 10. DLS provider sends UA to DLS user (right). 11. DLS provider sends DL-DISCONNECT confirm to DLS user (right). The diagram is labeled T0811010-92/d26. + +FIGURE III-10/T.90 + +**Resetting not accepted by both** + +### III.2 State transition diagrams HDLC + +### III.2.1 The relation between the diagrams + +The following diagrams describe the HDLC procedure as one functional unit. The first page comprises the whole protocol and the following pages give the details to specific states. + +### III.2.2 Abbreviations + +| | | +|--------|-----------------------------------| +| ABM | Asynchronous balanced mode | +| ADM | Asynchronous disconnected mode | +| R:xxx | Receive xxx (command or response) | +| R:Cxxx | Receive A command | +| R:Rxxx | Receive A response | +| S:xxx | Send xxx | +| F | Final bit | +| P | Poll bit | +| XXX | Not this condition | + +| | | +|-----------------|--------------------------------| +| RC | Redrive counter | +| RCB | Redrive counter busy | +| IC | I-Frame counter | +| V su | Variable for sequence updating | + +### III.3 *Summary of frame definitions* + +### III.3.1 *Invalid frames* + +- frames not properly bounded by flags; +- frames containing addresses other than A or B; +- frames with frame check sequence (FCS) error; +- frames containing less than 32 bis between flags. + +### III.3.2 *Valid frames* + +#### III.3.2.1 *Not expected frames* + +NEF, not expected frames (for the receiver) which lead to a frame reject condition (excluding frames with an FRMR control field): + +- | | | +|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------| +|
  • – a command or response control field that is undefined or not implemented
| Type W | +|
  • – a frame with an information field which is not permitted or supervisory or unnumbered frame with incorrect length
| Type X | +|
  • – an I-frame with an information field which exceeds the maximum established length
| Type Y | +|
  • – a frame with an invalid N(R)
| Type Z | + +#### III.3.2.2 *Expected frames* + +- frames which must lead to a reaction (in accordance to the Recommendation) on the receiving station, +- frames which must be ignored only in determined states on the receiving station. + +![State transition diagram for HDLC showing states 0 through 6 and transitions between them. The diagram is divided into three main phases: Disconnected phase, Link set-up phase, and Information transfer phase. It also includes a Link disconnection section. Transitions are triggered by various events like DL-DEACT req., DL-ACT req., DL-DISC ind., DL-CON req., DL-REACT resp., DL-RESET ind., DL-REACT req., DL-DISC req., and R: DISCONNECTION. States contain specific actions like setting flags, addresses, and timers.](dbd074feb5cce1300f42f91da8f673d1_img.jpg) + +The diagram illustrates the state transitions for HDLC, organized into three main phases: Disconnected phase, Link set-up phase, and Information transfer phase. It also includes a Link disconnection section. + +**States and Transitions:** + +- Any state** (Start): + - DL-DEACT req. → **Stop flag** (State 0) +- State 0** (Stop flag): + - DL-ACT req. (Address A or B) → **DL-ACT conf. SET ADDRESS SEND FLAG SET T3** (State 1) +- State 1** (DL-ACT conf. SET ADDRESS SEND FLAG SET T3): + - R: COMMANDS, P=1 → **S: DM, F=1** (State 1) + - R: SABM → **S: SABM, P=1 SET T1 RC=N2-1 RESET T3** (State 2) + - R: DISCONNECTION → **S: UA, F=P DL-DISC ind.** (State 3, 4, 5) + - R: DM, F=1 → **DL-DISC ind. RESET T1** (State 2) + - R: DM, F=P → **S: DM, F=P DL-DISC ind.** (State 1) +- State 2** (S: SABM, P=1 SET T1 RC=N2-1 RESET T3): + - R: SABM → **S: UA, F=P** (State 2) + - R: UA, F=1 → **S: SABM, P=1 RC=RC-1, SET T1** (State 2) + - R: DISCONNECTION → **S: UA, F=P DL-DISC ind.** (State 3, 4, 5) + - R: DM, F=1 → **DL-DISC ind. RESET T1** (State 2) + - R: DM, F=P → **S: DM, F=P DL-DISC ind.** (State 1) +- State 3** (S: UA, F=P DL-DISC ind.): + - R: NEF → **S: FRMR, SET T1 DL-RESET ind. RC=N2-1** (State 4) + - R: FRMR → **S: UA, F=P N(R)=0, N(S)=0 RESET T1** (State 3) + - R: SABM → **S: UA, F=P N(R)=0, N(S)=0 DL-RESET ind.** (State 3) + - R: SABM → **S: UA, F=P** (State 5) +- State 4** (S: FRMR, SET T1 DL-RESET ind. RC=N2-1): + - R: COMMAND, P=1 → **S: FRMR, F=1** (State 4) + - R: SABM → **S: FRMR, SET T1 RC=RC-1** (State 4) + - R: DISCONNECTION → **S: UA, F=P** (State 6) +- State 5** (S: UA, F=P): + - R: SABM → **S: UA, F=P** (State 5) + - R: DISCONNECTION → **S: UA, F=P** (State 6) +- State 6** (S: UA, F=P): + - R: DISCONNECTION → **S: DISC, P=1 SET T1 RC=N2-1** (State 6) + - R: DISCONNECTION → **S: DISC, P=1 RC=RC-1 SET T1** (State 6) + +**Phases and Transitions:** + +- Disconnected phase:** Includes states 0, 1, 3, 4, 5. +- Link set-up phase:** Includes states 1, 2. +- Information transfer phase:** Includes states 3, 4, 5. +- Link disconnection:** Includes states 4, 5, 6. + +**Transitions:** + +- DL-DEACT req. (Any state to 0) +- DL-ACT req. (Address A or B) (0 to 1) +- R: COMMANDS, P=1 (1 to 1) +- R: SABM (1 to 2) +- R: DISCONNECTION (1 to 3, 4, 5) +- R: DM, F=1 (1 to 2) +- R: DM, F=P (1 to 1) +- R: UA, F=1 (2 to 2) +- R: SABM (2 to 2) +- R: UA, F=P (2 to 2) +- R: DISCONNECTION (2 to 3, 4, 5) +- R: DM, F=1 (2 to 2) +- R: DM, F=P (2 to 1) +- R: NEF (3 to 4) +- R: FRMR (3 to 3) +- R: SABM (3 to 3) +- R: SABM (3 to 5) +- R: COMMAND, P=1 (4 to 4) +- R: SABM (4 to 4) +- R: DISCONNECTION (4 to 6) +- R: DISCONNECTION (5 to 6) +- R: DISCONNECTION (6 to 6) +- R: DISCONNECTION (6 to 6) + +State transition diagram for HDLC showing states 0 through 6 and transitions between them. The diagram is divided into three main phases: Disconnected phase, Link set-up phase, and Information transfer phase. It also includes a Link disconnection section. Transitions are triggered by various events like DL-DEACT req., DL-ACT req., DL-DISC ind., DL-CON req., DL-REACT resp., DL-RESET ind., DL-REACT req., DL-DISC req., and R: DISCONNECTION. States contain specific actions like setting flags, addresses, and timers. + +T0811020-92/d27 + +FIGURE III-11/T.90 +State transition diagram HDLC + +![State transition diagram HDLC (3 Information transfer phase, I-frame control)](2580688a4de0a29692805cc6ba4822d7_img.jpg) + +``` + + graph TD + S31((3.1)) -- "R: ∧ N(R)=V(S) ∧ P=1 ∧ BUSY" --> S31 + S31 -- "R: ∧ N(R)=V(S) ∧ P=1 ∧ ¬BUSY" --> S31 + S31 -- "R: RR ∨ ∧ N(R)=V(S)" --> S31 + S31 -- "R: ∧ N(R)≠V(S) ∧ P=1 ∧ BUSY" --> S31 + S31 -- "R: ∧ N(R)≠V(S) ∧ P=1 ∧ ¬BUSY" --> S31 + S31 -- "R: RR ∨ ∧ N(R)≠V(S)" --> S31 + S31 -- "R: REJ ∨ " --> S31 + S31 -- "R: DL-DATA req." --> IC_INC[IC=IC+1] --> S31 + S31 -- "IC > 0 ∧ DIFF < 7" --> PH_DATA[S: PH-DATA req. +V(S)=V(S)+1 +IC=IC-1 +SET T1] --> S31 + S31 -- "R: < ∨ T1> ∧ BUSY" --> S31 + S31 -- "R: CRNR ∧ P=1 ∧ ¬BUSY" --> S31 + S31 -- "R: ∧ ¬BUSY" --> S31 + S31 -- "R: CRNR ∧ P=1 ∧ BUSY" --> S31 + + S31 -- "R: ∧ ¬BUSY" --> S32((3.2)) + S32 -- "T1 ∧ RC > 0 ∧ ¬BUSY" --> S32 + S32 -- "R: RNR ∧ F=1" --> S32 + S32 -- "T1 ∧ RC > 0 ∧ BUSY" --> S32 + S32 -- "R: RR F=1 ∧ N(R)=V(S)" --> S31 + S32 -- "R: [REJ ∧ F=1] ∨ [RR ∧ F=1 ∧ N(R)≠V(S)]" --> S31 + S32 -- "R: (CRR ∨ CREJ ∨ CRNR) ∧ P=1 ∧ BUSY" --> S32 + +``` + +The diagram illustrates the state transitions for HDLC Information transfer phase. Node 3.1 is the primary state for sending I-frames. Node 3.2 represents the timer recovery condition. Transitions are triggered by received frames (R:) or internal events like timer expiration (T1) or data requests. Actions (S:) include sending response frames (RR, RNR, CRR, etc.) and updating state variables like V(S), IC, and RC. + +State transition diagram HDLC (3 Information transfer phase, I-frame control) + +a) Alternatively to RR, P = 1 it is allowed to send PH-DATA req. P = 1 or CREJ, P = 1. + + FIGURE III-12/T.90 +**State transition diagram HDLC + (3 Information transfer phase, I-frame control)** + +50 Recommendation T.90 + +![State transition diagram HDLC (3 Information transfer phase, I-frame control with update of N(R) in timer recovery condition). The diagram shows two states, 3.1 and 3.2, with various transitions based on received frames (R) and sent frames (S).](4162c218fc7881cd90fc9574e07d2327_img.jpg) + +R: ∧ ∧ P=1 ∧ BUSY + R: ∧ ∧ P=1 ∧ BUSY + R: RR ∨ ∧ N(R)=V(S) + R: ∧ ∧ P=1 ∧ BUSY + R: ∧ ∧ P=1 ∧ BUSY + R: RR ∨ ∧ N(R)≠V(S) + R: REJ ∨ + +S: RNR, F=1 + +S: RR, F=1 + +S: RNR, F=1 + +S: RR, F=1 + +3.1 + +IC>0 ∧ DIFF<7 + +S: PH-DATA req. + V(S)=V(S)+1 + IC=IC-1 + SET T1 + +SET T1 + Vsu=N(R) + +RESET T1 + Vsu=N(R) + +R: DL-DATA req. + +RESET T1 + IC=IC+V(S)-N(R) + Vsu=V(S)=N(R) + +IC=IC+1 + +R: < + ∨ T1> ∧ BUSY + R: CRNR ∧ P=1 ∧ BUSY + R: + ∧ BUSY + +R: CRNR ∧ + P=1 ∧ BUSY + +S: RNR, F=1 + +S: CRNR, P=1 + +S: RR, F=1 + +S: CRR, P=1a) + +RESET T1 + Vsu=N(R) + +RESET T1 + IC=IC + V(S) - N(R) + Vsu=V(S)=N(R) + +Sending I-frame + +R: [REJ ∧ F=1] ∨ [RR ∧ F=1 ∧ N(R) ≠ V(S)] + +R: RR F=1 ∧ + N(R)=V(S) + +R: [ ∧ F=0 ∨ + ] ∧ BUSY + +Vsu=N(R), SET T1 + SET RC=N2-1 + SET RCB=N2-1 + +R: ∧ BUSY + +R: (CRR ∨ CREJ ∨ CRNR) ∧ P=1 ∧ BUSY + +T1 ∧ RC>O ∧ BUSY + +R: RNR ∧ F=1 + +S: RNR, F=1 + Vsu=N(R) + +S: RR, F=1 + Vsu=N(R) + +3.2 + +T1 ∧ RC>O ∧ BUSY + +Vsu=N(R) + +S: CRR, P=1a) + RC=RC-1 + SET T1 + +SET RC=N2-1 + RCB=RCB-1 + Vsu=N(R) + +S: CRNR, P=1 + RC=RC-1 + SET T1 + +Timer + recovery + condition + +State transition diagram HDLC (3 Information transfer phase, I-frame control with update of N(R) in timer recovery condition). The diagram shows two states, 3.1 and 3.2, with various transitions based on received frames (R) and sent frames (S). + +T0811040-92/d29 + +a) Alternatively to RR, P = 1 it is allowed to send PH-DATA req. P = 1 or CREJ, P = 1. + +FIGURE III-13/T.90 + +State transition diagram HDLC + (3 Information transfer phase, I-frame control with update of N(R) + in timer recovery condition) + +![State transition diagram HDLC (3.1 Information transfer phase, I-frame acknowledgement) showing states 3.1.1, 3.1.2, and 3.1.3 with various transitions and actions.](701bc79e78b382bcfd3ba85597dbb9c3_img.jpg) + +The diagram illustrates the state transitions for the HDLC (3.1 Information transfer phase, I-frame acknowledgement) protocol. It features three main states: 3.1.1, 3.1.2, and 3.1.3. + +**State 3.1.1:** This state is associated with the "Receiving I-frame" condition. Transitions from 3.1.1 include: + +- Receiving I-frame:** + - $R: PH-DATA\ ind.\ \wedge N(S)=V(R)\ \wedge \overline{BUSY}\ \wedge N(R)=V(S)$ leads to a box with actions: $V(R)=V(R)+1$ , $S: RR, F=P$ , $DL-DATA\ ind.$ , $RESET\ T1$ , $V_{su}=N(R)$ . + - $R: PH-DATA\ ind.\ \wedge N(S)=V(R)\ \wedge \overline{BUSY}\ \wedge N(R)'V(S)$ leads to a box with actions: $V(R)=V(R)+1$ , $S: RR, F=P$ , $DL-DATA\ ind.$ , $SET\ T1$ , $V_{su}=N(R)$ . + - $R: PH-DATA\ ind.\ \wedge N(S)'V(R)\ \wedge N(R)=V(S)$ leads to a box with actions: $S: REJ, F=P$ , $RESET\ T1$ , $V_{su}=N(R)$ . + - $R: PH-DATA\ ind.\ \wedge N(S)'V(R)\ \wedge N(R)'V(S)$ leads to a box with actions: $S: REJ, F=P$ , $SET\ T1$ , $V_{su}=N(R)$ . +- N(S) sequence error condition:** + - $R: PH-DATA\ ind.\ \wedge N(S)=V(R)\ \wedge N(R)=V(S)$ leads to a box with actions: $V(R)=V(R)+1$ , $S: RR, F=P$ , $DL-DATA\ ind.$ , $RESET\ T1$ , $V_{su}=N(R)$ . + - $R: PH-DATA\ ind.\ \wedge N(S)=V(R)\ \wedge N(R)'V(S)$ leads to a box with actions: $V(R)=V(R)+1$ , $S: RR, F=P$ , $DL-DATA\ ind.$ , $RESET\ T1$ , $V_{su}=N(R)$ . +- BUSY condition:** + - $R: PH-DATA\ ind.\ \wedge \overline{BUSY}$ leads to a box with action: $S: RNR, F=P$ . + +**State 3.1.2:** This state is associated with the "N(S) sequence error condition" and "BUSY condition". Transitions from 3.1.2 include: + +- N(S) sequence error condition:** + - $R: PH-DATA\ ind.\ \wedge N(S)'V(R)\ \wedge N(R)=V(S)\ \wedge P=1\ \wedge \overline{BUSY}$ leads to a box with actions: $S: REJ, F=1$ , $RESET\ T1$ , $V_{su}=N(R)$ . + - $R: PH-DATA\ ind.\ \wedge N(S)'V(R)\ \wedge N(R)'V(S)\ \wedge \overline{BUSY}$ leads to a box with actions: $S: REJ, F=1$ , $SET\ T1$ , $V_{su}=N(R)$ . +- BUSY condition:** + - $PH-DATA\ ind.\ \wedge \overline{BUSY}$ leads to a box with action: $S: RNR, F=P$ . + +**State 3.1.3:** This state is associated with the "BUSY condition". Transitions from 3.1.3 include: + +- BUSY condition:** + - $PH-DATA\ ind.$ leads to a box with action: $S: RNR, F=P$ . + +**Transitions between states:** + +- From 3.1.1 to 3.1.2: $R: PH-DATA\ ind.\ \wedge \overline{BUSY}$ +- From 3.1.2 to 3.1.1: $R: PH-DATA\ ind.\ \wedge \overline{BUSY}$ +- From 3.1.2 to 3.1.3: $PH-DATA\ ind.\ \wedge \overline{BUSY}$ +- From 3.1.3 to 3.1.2: $PH-DATA\ ind.\ \wedge \overline{BUSY}$ +- From 3.1.3 to 3.1.1: $R: PH-DATA\ ind.\ \wedge \overline{BUSY}$ +- From 3.1.1 to 3.1.3: $R: PH-DATA\ ind.\ \wedge \overline{BUSY}$ + +State transition diagram HDLC (3.1 Information transfer phase, I-frame acknowledgement) showing states 3.1.1, 3.1.2, and 3.1.3 with various transitions and actions. + +T0811050-92/d30 + +FIGURE III-14/T.90 +State transition diagram HDLC +(3.1 Information transfer phase, I-frame acknowledgement) + +![State transition diagram HDLC (3.2 Information transfer phase, I-frame acknowledgement in exception conditions). The diagram shows three states: 3.2.1, 3.2.2, and 3.2.3. Transitions are labeled with events and actions. Brackets on the right group transitions into 'Receiving I-frame', 'N(S) sequence error condition', and 'BUSY condition'.](89f8aefc01866631793087542316cef2_img.jpg) + +``` +stateDiagram-v2 + state 3.2.1 + state 3.2.2 + state 3.2.3 + + 3.2.1 --> 3.2.1 : R: PH-DATA ind. ∧ N(S)=V(R) ∧ ̅B̅U̅S̅Y̅ / V(R)=V(R)+1, S: RR, F=P, DL-DATA ind. + 3.2.1 --> 3.2.2 : R: PH-DATA ind. ∧ N(S) ≠ V(R) / S: REJ, F=P + 3.2.1 --> 3.2.3 : R: PH-DATA ind. ∧ BUSY / S: RNR, F=P + 3.2.2 --> 3.2.1 : R: PH-DATA ind. ∧ N(S)=V(R) ∧ ̅B̅U̅S̅Y̅ / S: RR, F=P, DL-DATA ind., V(R)=V(R)+1 + 3.2.2 --> 3.2.2 : R: PH-DATA ind. ∧ N(S) ≠ V(R) ∧ P=1 ∧ ̅B̅U̅S̅Y̅ / S: REJ, F=1 + 3.2.2 --> 3.2.3 : PH-DATA ind. ∧ BUSY / S: RNR, F=P + 3.2.3 --> 3.2.3 : PH-DATA ind. ∧ BUSY / S: RNR, F=P + 3.2.3 --> 3.2.2 : RESET BUSY +``` + +Receiving +I-frame + +N(S) sequence +error condition + +BUSY condition + +T0811060-92/d31 + +State transition diagram HDLC (3.2 Information transfer phase, I-frame acknowledgement in exception conditions). The diagram shows three states: 3.2.1, 3.2.2, and 3.2.3. Transitions are labeled with events and actions. Brackets on the right group transitions into 'Receiving I-frame', 'N(S) sequence error condition', and 'BUSY condition'. + +FIGURE III-15/T.90 + +**State transition diagram HDLC** +**(3.2 Information transfer phase, I-frame acknowledgement** +**in exception conditions)** + +![State transition diagram HDLC for 3.2 Information transfer phase, I-frame acknowledgement in exception conditions with update of N(R).](a2251e3bbfcd726b68cc50b091e53b02_img.jpg) + +``` + +stateDiagram-v2 + state 3.2.1 + state 3.2.2 + state 3.2.3 + state S_RR_F_P["S: RR, F=P +DL-DATA ind. +Vsu=N(R) +V(R)=V(R)+1"] + state S_REJ_F_P["S: REJ, F=P +Vsu=N(R)"] + state S_RNR_F_P["S: RNR, F=P"] + state S_REJ_F_1["S: REJ, F=1 +Vsu=N(R)"] + state S_RNR_F_P_2["S: RNR, F=P"] + + 3.2.1 --> 3.2.1 : R: PH-DATA ind. ^ N(S)=V(R) ^ BUSY + 3.2.1 --> 3.2.1 : V(R)=V(R)+1 +S: RR, F=P +DL-DATA ind. +Vsu=N(R) + 3.2.1 --> 3.2.2 : R: PH-DATA ind. ^ N(S)'V(R) + 3.2.1 --> S_RR_F_P : S: RR, F=P +DL-DATA ind. +Vsu=N(R) +V(R)=V(R)+1 + 3.2.1 --> S_REJ_F_P : S: REJ, F=P +Vsu=N(R) + 3.2.2 --> 3.2.1 : R: PH-DATA ind. ^ N(S)=V(R) ^ BUSY + 3.2.2 --> 3.2.2 : R: PH-DATA ind. ^ N(S)'V(R) ^ P=1 ^ BUSY + 3.2.2 --> 3.2.2 : S: REJ, F=1 +Vsu=N(R) + 3.2.2 --> S_RNR_F_P : S: RNR, F=P + 3.2.2 --> 3.2.3 : PH-DATA ind. ^ BUSY + 3.2.3 --> 3.2.2 : RESET BUSY + 3.2.3 --> 3.2.3 : PH-DATA ind. ^ BUSY + 3.2.3 --> 3.2.3 : S: RNR, F=P + 3.2.3 --> 3.2.1 : R: PH-DATA ind. ^ BUSY + +``` + +The diagram illustrates the state transitions for the HDLC 3.2 Information transfer phase, I-frame acknowledgement in exception conditions with update of N(R). The states are represented by ovals (3.2.1, 3.2.2, 3.2.3) and the actions by rectangles. + +- State 3.2.1:** Initial state. Transitions include: + - Self-loop: R: PH-DATA ind. ^ N(S)=V(R) ^ BUSY + - Self-loop: V(R)=V(R)+1, S: RR, F=P, DL-DATA ind., Vsu=N(R) + - Transition to 3.2.2: R: PH-DATA ind. ^ N(S)'V(R) + - Transition to S: RR, F=P, DL-DATA ind., Vsu=N(R), V(R)=V(R)+1 + - Transition to S: REJ, F=P, Vsu=N(R) +- State 3.2.2:** Intermediate state. Transitions include: + - Transition to 3.2.1: R: PH-DATA ind. ^ N(S)=V(R) ^ BUSY + - Self-loop: R: PH-DATA ind. ^ N(S)'V(R) ^ P=1 ^ BUSY + - Self-loop: S: REJ, F=1, Vsu=N(R) + - Transition to S: RNR, F=P + - Transition to 3.2.3: PH-DATA ind. ^ BUSY +- State 3.2.3:** Final state. Transitions include: + - Transition to 3.2.2: RESET BUSY + - Self-loop: PH-DATA ind. ^ BUSY + - Self-loop: S: RNR, F=P + - Transition to 3.2.1: R: PH-DATA ind. ^ BUSY + +State transition diagram HDLC for 3.2 Information transfer phase, I-frame acknowledgement in exception conditions with update of N(R). + +T0811070-92/d32 + +FIGURE III-16/T.90 + +**State transition diagram HDLC** +**[3.2 Information transfer phase, I-frame acknowledgement** +**in exception conditions with update of N(R)]** + +(to Recommendation T.90) + +## **Possible model for telematic endsystems taking into account the D-channel/B-channel coordination function** + +![Diagram of a telematic endsystem model showing OSI layers 1 to 7. Layers 4-7 are grouped as 'Telematic protocols layers 4 to 7'. Layer 3 is a bracketed group containing 'D-/B- channel coordination function', 'Q.931', and 'ISO/CEI 8208'. Layer 2 contains 'Q.921 (LAPD)' and 'ISO/CEI 7776 DTE-DTE operation'. Layer 1 is split into '' and '', with 'I.430 - I.431' spanning both. A reference 'T0805801-91' is at the bottom right.](7ed5d5770331f31ade15439a21c31425_img.jpg) + +| | | | +|-----------|-------------------------------------|--------------------------------| +| OSI Layer | | | +| 4 to 7 | Telematic protocols layers 4 to 7 | | +| 3 | D-/B- channel coordination function | | +| | Q.931 | ISO/CEI 8208 | +| 2 | Q.921 (LAPD) | ISO/CEI 7776 DTE-DTE operation | +| 1 | | | +| | I.430 - I.431 | | +| | T0805801-91 | | + +Diagram of a telematic endsystem model showing OSI layers 1 to 7. Layers 4-7 are grouped as 'Telematic protocols layers 4 to 7'. Layer 3 is a bracketed group containing 'D-/B- channel coordination function', 'Q.931', and 'ISO/CEI 8208'. Layer 2 contains 'Q.921 (LAPD)' and 'ISO/CEI 7776 DTE-DTE operation'. Layer 1 is split into '' and '', with 'I.430 - I.431' spanning both. A reference 'T0805801-91' is at the bottom right. + +FIGURE IV-1/T.90 + +### **Model for telematic endsystems taking into account the D-channel/B-channel coordination function** + +There are various ways of specifying the layer 3 coordination function. In principle, the layer 3 can either be specified as a monolith or as a set of individual modules. + +The structuring into the three modules: + +- layer 3 D-channel; +- layer 3 B-channel, and +- layer 3 D-/B-channel coordination, + +is obvious, as the first two modules are almost ready-made, available thus leaving the coordination module to be specified from the functionality point of view. The implementation itself is the responsibility of the manufacturer. + +# APPENDIX V + +(to Recommendation T.90) + +## Rate adaptation function + +Circuit switched mode with 64 kbit/s digital bearer capability will have many chances to interwork with CSPDNs and other digital networks. In such cases, ISDN terminal may need rate adaptation function. Rate adaptation function can be achieved by procedure defined in Recommendation V.110. The following is the example of invoking rate adaptation in SETUP message (see Recommendation Q.931) when telematic terminal interworks with existing terminal using Recommendation V.110 rate adaptation. + +## Coding example for bearer capability (circuit switched mode, user rate = 56 kbit/s) + +| Octet | Field | Calling side | Called side | +|-------|-----------------------------------|----------------------|-------------| +| 1 | IE identifier | Bearer capability | | +| 2 | Length | | | +| 3 | Coding standard | CCITT | Requisite | +| | Information transfer capability | Unrestricted digital | (Note 1) | +| 4 | Transfer mode | Circuit mode | (Note 1) | +| | Information transfer rate | 64 kbit/s | (Note 2) | +| 5 | Layer 1 identifier | “0 1” | (Note 1) | +| | User information layer 1 protocol | V.110/X.30 | (Note 2) | +| 5a | Synchronous/Asynchronous | Synchronous | (Note 2) | +| | Negotiation | Not possible | (Note 2) | +| | User rate | 56 kbit/s | (Note 2) | + +*Note 1* – Called side recognizes the value and changes its mode. + +*Note 2* – If this field exists, called side responds only when it has the capability indicated by the calling side. + +# APPENDIX VI (to Recommendation T.90) + +## **Recommended combinations of parameter values to ensure optimum throughput** + +| | LLC IE | | | | | | | | +|----------------------------|--------|------|----------|----------|----------|----------|----------|--------| +| | Octet | Bits | Case 1 | Case 2 | Case 3 | Case 4 | Case 5 | Case 6 | +| Layer 2 mode | 6a | 7-6 | Extended | Extended | Extended | Extended | Extended | Normal | +| k parameter | 6b | 7-1 | 80 | 40 | 20 | 10 | 7 | 7 | +| Layer 3 mode | 7a | 7-6 | Extended | Extended | Extended | Extended | Extended | Normal | +| Packet size | 7b | 4-1 | 128 | 256 | 512 | 1024 | 2048 | 2048 | +| Layer 3 packet window size | 7c | 7-1 | 80 | 40 | 20 | 10 | 7 | 7 | + +*Note* – The implementation of case 1 is strongly recommended. + +# APPENDIX VII (to Recommendation T.90) + +## **Alphabetical list of abbreviations used in this Recommendation** + +| | | +|-------|--------------------------------------| +| ABM | Asynchronous balanced mode | +| ADM | Asynchronous disconnected mode | +| BC | Bearer capability | +| CS | Circuit switched | +| CSPDN | Circuit switched public data network | +| CUG | Closed user group | +| DM | Disconnected mode | +| EETDN | End-to-end transit delay negotiation | +| FCS | Frame check sequence | +| FI | Format identifier | + +| | | +|-----------------|---------------------------------------------| +| FRMR | Frame reject | +| GI | Group identifier | +| GL | Group length | +| HDLC | High-level data link control | +| HLC | High layer compatibility | +| IC | I-frame counter | +| IE | Information element | +| ISDN | Integrated services digital network | +| IWF | Interworking function | +| LLC | Low layer compatibility | +| LLC-IE | Low layer compatibility information element | +| MSN | Multiple subscriber number | +| NEF | Not expected frame | +| NL | Network layer | +| PHS | Physical service | +| PI | Parameter identifier | +| PL | Parameter length | +| PLP | Packet layer protocol | +| PS | Packet switched | +| PSPDN | Packet switched public data network | +| PSTN | Public switched telephone network | +| PV | Parameter value | +| RC | Redrive counter | +| RCB | Redrive counter busy | +| RPOA | Recognized private operating agency | +| SLP | Single link procedure | +| TA | Terminal adaptor | +| TDSAI | Transit delay selection and indication | +| TPDU | Transport protocol data unit | +| V su | Variable for sequence updating | +| XID | Exchange identification | \ No newline at end of file